Saturday, October 29, 2011

"Damaging Heavy Wet Snow" 
-National Weather Service, Taunton MA


6:00 PM EDT 10/29/11 This report is reposted from our Northeast Winter Stormcast Zone on facebook, prepared by Forecasters Jason M., Mike N., Connor M., and Advisor Foot. A State of Emergency for New Jersey was recently announced by Governor Christie for up to 500,000 power outages across the state, and nearly 1.7 million so far fort the Mid-Atlantic and Northeastern U.S.

The surface low pressure responsible for delivering a record-breaking October snowstorm to much of eastern Pennsylvania and New Jersey is currently located just off the Delmarva coast.  The storm has received a high energy injection of tropical moisture from the remnants of once-Hurricane Rina. As a result, we expect snowfall amounts to be significantly higher across New England than were originally forecasted. 

The current extent of NWS warnings at:

This classic nor’easter has deepened quickly, and has formed an “eye” off the coast. Only a handful of nor’easters have developed an eye off the coast. The NWS is aware of this rapid strengthening and has posted a hurricane force wind warning for just offshore the New England Coast. NWS Taunton, MA: Area outside of this may see gust up to 50 mph following passage of the storm tonight, which will add to the widespread power outages already reported in New Jersey, with up to a third of the state without power presently. 

Forecaster Mike Natoli has the latest Metro NYC forecast posted at: 

LOCAL REPORT FROM NJ: We have just spoken with one of our Maryland colleagues in Emergency Management visiting in NJ. They report power outages throughout the area, over 6 inches near Bloomfield, NJ with heavy snow in progress and trees overloaded with snow. With winds forecasted by the NWS to gust near 50 mph tonight throughout NJ, NY and southern New England, this region is facing a significantly damaging event which could rival the power outage impacts of Irene.

FOR ADDITIONAL DETAILS, please visit our Winter Stormcast Northeast page in facebook.

Friday, October 28, 2011

A trick for some, a treat for others

The image below contains our final storm projections for this event. Once all Local Storm Reports have been submitted to the respective NWS office, we a member of our team outside the Mid-Atlantic will conduct an independent verification of our results and grade the storm, based on the departure between predicted and actual.  

If you want to take part in recording this historic event, you are welcome to post imagery and observations in the comment feature on this page, or to your local team in facebook as linked below. Many readers in Maryland and Virginia are already reporting snow on secondary roads, cars and grassy surfaces.

WINTER STORMCAST ZONES Mid-Atlantic | Northeast 
VIRGINIA Central | Northern | Tidewater
WEST VIRGINIA Potomac Ridge & Valley 
MARYLAND   Capital Region | Central |  Northern Bayshore 
PENNSYLVANIA   Southeast | Central | Three Rivers
NEW YORK  Central NY State | New York Metro

8:50 AM EDT 10/29/11 A SIGHT YOU'VE NEVER SEEN The image above from the NWS Eastern Regional Headquarters depicts the current extent of Winter Storm Warnings and related Winter advisories along the Mid-Atlantic and Northeast. If this were December or after, we would all be saying, "well after all it is December you know." In October 2009 an early season snow brought up to six inches in State College, PA along with the subsequent power outages. It led to a post we titled "December in October?" That event gave our team an indication of what the winter would bring: Unexpected high impact events generated by a resurgent El Nino

Mr. Foot, Devon PA, Oct 1972
Now we are faced with a new wild card: A La Nina pattern producing a significant winter storm occuring very far outside the climatological norm. The only comparison we could find was back to October 1972 for so much snow this early. Thanks to Mr. Foot's Mother, we were able to dig up photo proof of the last time there was measurable snow at this time of year: October 18 and 19, 1972 as reported by Pennsylvania  Lehigh Valley's Morning Call in this article. Like Charleton Heston said in his gravelly voice at the opening of the 1998 film Armageddon, "It happened before, it will happen again. It's just a question of... when." 

             Winter Stormcast Zone returns

12:10 AM EDT 10/29/11 | WELCOME BACK TO THE WINTER STORMCAST ZONE. In advance of this significant early season storm, we have relaunched the most popular zone on this page from the previous two winters, found at this link. For those in schools or at work and unable to access facebook during the business day, this new tab will provide you with a wide-angle heads up on the next storm, as posted on the regional facebook page. 

6:15 PM EDT 10/28/11 | STORM UPDATE & ANALYSIS | While once-strong Hurricane Rina has drifted into weak Tropical Depression status, her parting gift may be an injection of moisture into the expected Mid-Atlantic and Northeast U.S. snowstorm. We have conducted extensive analysis of the situation throughout the day and are very concerned about several key  issues:

* POWER OUTAGES: While 8 or more inches may fall in places like Lancaster or Harrisburg in PA, and Westminster, Frederick MD-- perhaps just 4 inches will reach the ground due to the sun evaporating away the snow as it falls. However those 4 inches might actually contain 1 full inch of water. The weight of this water-laden snow on full foliage may produce extremely disruptive and complicated outages.

*DYNAMICAL COOLING: We are observing evidence that a high pressure system in Canada is starting to orient in the classic, but troubling "sweet spot" of southern Ontario. At 1025 mb, the cold air within this High is likely to be tapped by the developing ~1000mb low. The interaction of these two opposing pressure systems over a relatively small geographical area (the eastern mid Atlantic) could easily produce strong upward motion and in turn, dynamical cooling. This has the effect of allowing the storm to generate additional cold air, feeding on the decreasing temperatures as snow falls, and squeezing more snow out of the same amount of atmospheric moisture.  

*HEAVY SNOW BANDS: We believe some areas of central Maryland, central Virginia and central Pennsylvania may experience extremely high snowfall rates in a short period of time which could eclipse current NWS projections for those areas, especially if the snow becomes convective in nature as suggested by modeled data from the North American Mesoscale.

(Advisors Mr. Foot and Dr. Winstead, Forecasters Jason M., and Greg J.)

11:30 AM EDT 10/28/11 | SIGNIFICANT EARLY SEASON SNOWSTORM | The Snowfall Probability Graphic below is derived from the NOAA Winter Weather Product Suite as posted by the National Centers for Environmental Prediction in Camp Springs, MD. Many members of our team have visited this facility and interacted with their meteorologists. 

We have respect for their professional eye on winter weather, and concur with NOAA on this developing situation. By 5 PM this afternoon, the Winter Stormcast Team will be posting preliminary "Storm Grade Amounts" for representative locations in the Mid-Atlantic, as posted in a data graphic on this page. 

We have high confidence this event will be a significant snowfall for many areas east of Interstate 81 along the Mid-Atlantic and into the Northeastern U.S.

STORM SYNOPSIS: The arrival of a cold high pressure system last night across the Mid-Atlantic and Northeast has become the "game changer" of this storm situation. Low pressure in the Gulf of Mexico today will move northeast to off the North Carolina coast by early Saturday, and northward to New England by Sunday. Due to the pressure gradient interaction that is likely to setup between the coastal low and the cold high pressure system, we are in fact looking at a classic winter storm scenario for the populated areas of the I-95 corridor from Washington DC to the Baltimore region to eastern Pennsylvania, most of New Jersey, eastern New York and New England. 

Graphic:  Surface Low Tracks as projected by NOAA NCEP. 

PRIMARY HAZARDS: The multi-state Winter Storm Watches that started this Happy Friday for millions of people may seem like a joke in October, but belie a greater danger: Leaves. With 80% of the foliage still on trees throughout the Mid-Atlantic and Northeast, a heavy snow event, even if 3 or 4 inches, could produce surprisingly disruptive power outages. The moisture content of any snow falling this time of year will be much higher than what would be observed in mid winter. Our main concerns:

* POWER OUTAGES: While 8 inches may fall in places like Lancaster or Harrisburg in PA, and Westminster, Frederick or Rockville, MD-- perhaps just 4 inches will reach the ground due to the sun evaporating away the snow as it falls. However those 4 inches might actually contain 1 full inch of water. The weight of this water-laden snow on full foliage may produce extremely disruptive and complicated outages.

* VISIBILITY: In Pennsylvania, New Jersey and along the I-95 corridor from Philadelphia to Washington, rain on Saturday should mix with and change to snow as the afternoon progresses. However, once snow does fully change over, we expect it to be falling rapidly and in large flakes. The primary risk period is from 4 to 8 PM, as the heaviest snowfall should occur during the busiest commuting time of the day, even for a Saturday. You will probably notice how quickly the ground becomes covered tomorrow afternoon as the sun begins to set, allowing the ground to chill further as the snow falls. 

* LACK OF PUBLIC AWARENESS: A reader from Lancaster PA noted to the team, "how can we be getting 4 to 8 inches tomorrow, it is a gorgeous sunny day right now?" All we can say is that La Nina is known for producing short term, high impact events that catch many people off guard. It is difficult to accept that by noon on Saturday, those seeing blue skies presently may be digging for the snowshovel in the basement.  

WHY IS THIS HAPPENING? We know it is only October, and historically these kinds of winter weather events do not happen this far outside of winter. However, a resurgent La Nina has played a major role in the variability and frequency of both hurricanes and mid-latitude cyclones. As NOAA stated in the recently released Winter Outlook, "“There is a wild card, though. The erratic Arctic Oscillation can generate strong shifts in the climate patterns that could overwhelm or amplify La NiƱa’s typical impacts.”  It is interesting to note that just over a week after this statement, the Mid-Atlantic faces a wild card storm event that is, ironically, occuring just as the Arctic Oscillation is currently in a negative trend.

NEXT TEAM REPORT: Our Winter Stormcast Team is assembling a new overview presently, and will post this afternoon on this site as well as in our Mid-Atlantic and Northeast Winter Stormcast Zones on facebook.

(Forecasters Foot, Jason and Dakota. Advisors Dr. Pete Winstead, Brad Lear Keith Krichinsky)

Thursday, October 27, 2011

October Surprise, Part II ?

11:00 PM EDT 10/27/11 | TEAM STATEMENTS ON WEEKEND STORM | Please visit the Mid-Atlantic Winter Stormcast Page in Facebook for rapid access to our storm projections organized by state for the Halloweekend winter weather event.

4:30 PM EDT 10/27/11 | WINTER STORMCAST TEAM UPDATE | Last night, the Winter Stormcast Team released a statement regarding the potential for some flakes mixing in with rain this weekend. However, latest computer model projections show that we will not be getting off as easily as we thought. Snow may be more of an issue here in Central Maryland than the computer models once indicated. With trees still full of leaves and potential wet snow in the forecast, power outages could be a major issue this weekend. 

Your Foot's Forecast Mid-Atlantic team will be collaborating for most of the evening to work up a detailed *TEAM STATEMENT* to be released between 9:00 PM and 10:00 PM tonight. This weekend will be very busy like usual with activities such as Homecoming and Halloween festivities. If you have anything planned for this weekend, we urge you to keep checking in for more on this developing situation. (Lead Forecaster Connor Meehan)

7:30 PM EDT 10/26/11 | WINTER STORMCAST PRELIMINARY STATMENTAlthough the Mid Atlantic has had several mild days recently, major changes are coming to the region later this week. A cold front will usher in a significantly cooler airmass by late Thursday. We are watching for the potential of a weak storm to develop off the Carolina to Mid-Atlantic coast late Friday into Saturday. Temperatures across much of the Mid Atlantic Friday night will be in the upper 30s, and this will allow for a chilly rain to fall. Although these temperatures do not usually support any snow, temperatures throughout much of the atmosphere will be below freezing. 

TIMING: From the early morning hours Saturday through mid-morning, we believe there will be the possibility for snowflakes to mix in. The best chance for this will be across the northern and western suburbs of Washington, D.C. and Baltimore. However, areas within 25 miles of the Chesapeake Bay will have a harder time mixing with snow due to the warmer temperatures over the bay. 

IMPACTS: At this time we do not expect any snowfall accumulation for any portion of the region, and we are not expecting a period of all snow. Rainfall amounts will be up to one half inch, with the highest amounts across eastern portions of the region. Although this storm system should not have any significant impacts for the region, it is not a common occurrence for snowflakes to fall along the I-95 corridor in October. 

NEXT UPDATE: This is an evolving situation and our team is continuing to monitor for changes to any computer model projections, as well as traditional meteorological analysis of current observations. We will report on our findings as the evening progresses.  

(Author: Forecaster Jason M. Collaborators: Forecasters Ross H., Mike N.)

Tuesday, October 25, 2011

Thursday, 27 October
11:15 AM EDT

Rina is now a Tropical Storm, with a path that will steer it away from the U.S.

Snow will fall from Pennsylvania into Maine today and tonight. This system will move quickly northeast, with precipitation coming to an end pre-dawn Friday morning.

A second storm system will move into New Mexico bringing moderate snow before turning into a rain/thunderstorm event later today across the Southern Plains.

The system then moves eastward through the Deep South before running into the cold air mass bringing the possibility of light snows to parts of the Central Appalachians Friday evening.

Rains will spread into the Pacific Northwest on Friday.

Wednesday, 26 October
3:05 PM EDT

Rina has weakened to a Cat 1, and several disturbances are moving across the country. The most northern will move through the Mid-Mississippi Valley today, and quickly race off into the upper Mid-Atlantic by Thursday evening. The southernmost aspect of this of this upper trough is already bringing impacts to the Central Rockies with moderate to heavy snow.
As the system heads South into the southern High Plains, it will change to rain.

No confusion in Cozumel

7:00 PM EDT 10/25/11 | Tourists and residents in places like Cozumel, Mexico are now facing what could be by Thursday morning a full-on assault from nearly-Category 3 Hurricane Rina. Within 36 hours, the storm may be generating sustained winds of 120 mph or greater. If you have family or colleagues along the Mexico's Yucatan coast, we urge serious consideration of an early evacuation based on current projections. Several cruise lines have already made significant route changes due to the hurricane. There's simply no good reason to jeopardize your life and family to squeeze in one more day, catch the surf or "get a front row seat."

In addition to Rina, a new disturbance heading west near Venezuela will make for an interesting forecast situation by weeks' end. The new disturbance, denoted as 97L, is noted with a 30% chance of development. The challenge facing forecasters and Caribbean residents alike is sorting out what may happen if both storms begin to interact come Friday as they approach each other from opposite directions. (link: track guidance from CSU)

WHAT IS NEXT? The press of a cold front from the Southeast on Thursday will likely confound the forecast situation further, as shown in this NOAA map from the National Centers for Environmental Prediction. Hurricane Rina is expected to travel north-northwest and may strike or barely graze the Yucatan peninsula, then curve east toward the tip of Cuba. Invest 97L in the next 5 days is expected to curve northwest toward Jamaica. It is not unreasonable to expect some interaction between the two storms. This unusual circumstance by itself is not cause for alarm, both forecasters and computer models may have difficulty discerning an outcome.

WHO IS AT RISK? Interests and those traveling in the area, including the Belize - Mexico coast, Jamaica, Cuba, the Island of Hispaniola and South Florida, should closely monitor this variable situation over the next several days. If governments outside the U.S. issue watches or warnings, we will repost that information here for our readers. (Forecasters Foot, Jason M. and the Tropical Team)

Monday, October 24, 2011

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Early visit by the Polar Express?

10:40 PM 10/24/11 | Forecasters in the Southeast and readers in the Mid-Atlantic report northern lights across the region | This update posted at 10:05 AM with this report from Forecaster Daniel Ross in Atlanta, Georgia: 

"Thanks to a Coronal Mass Ejection from the Sun impacting the Earth's magnetic field, the Northern Lights have made a field trip South, with places as far South as Tennessee, Arkansas, and Mississippi reporting sightings. If you can see it from your house, send us a picture." 

Forecasters and readers are posting on the event in their respective facebook pages, feel free to post your local imagery there for others to share. The image above is from a reader in Ontario, Canada. Other imagery has been reported in Dayton, Ohio; London, Kentucky and in the Southeast.  (Forecaster Foot)
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A River Runs Through It
- 1992 film starring Brad Pitt and Craig Sheiffer

8:00 PM EDT 10/24/11 Those along the Florida coast and the interior Southeast should closely monitor the developments with Hurricane Rina. 
On-going updates and analysis of NHC statements are posted in our Tropical  Zone. The National Hurricance Center expects Rina to reach Category 3 status by TuesdayWere Rina to make a run for Florida, our forecast zones to be impacted would include Central Florida, led by Forecaster Matt Bolton, as well as South Florida & The Keys, led by Meteorologist Randall J. and Forecaster Amanda Brioche.  

(EARLIER UPDATE AS OF 10:00 AM EDT 10/24/11) Storms developing in this region of the Caribbean have a history of rapid intensification due to high oceanic heat content and favorable upper level conditions. In the past 20 years, several notable storms have intensified their way into the history books, and have had their named expunged from lists of future hurricanes. Examples include:

Hurricane Wilma, Oct. 2005
In late October 2005, Wilma exploded from a tropical storm to a Category 5 hurricane in 24 hours before charging across southwestern Florida as Category 3 hurricane on October 24. (NOAA National Climate Data Center Report). In September 1988, before making landfall in the Yucatan, Gilbert produced what some data indicates was the highest ever recorded sustained winds in an Atlantic basin hurricane: Clocked at 185 mph with gusts above 200 mph. (Source: NOAA / HPC and NCEP)

THE LA NINA / "ATMOSPHERIC RIVER" CONNECTION As members of our team learned in a Friday 10/21/11 visit with NOAA scientists at University of Maryland-College Park, there are occasional "river channels" of moisture that set up in the mid-levels of the atmosphere from time to time. (NOAA Research Report) A good couple dozen million folks in the Mid-Atlantic and Northeast need no more reminders of what these atmospheric rivers wreaked on their lives in August and September 2011. It is interesting to note that Wilma, Gilbert and the Irene-Lee period occurred when La Nina readings from the Pacific were observed to be in similar range over a three-month period.

A WINTER STORM CONNECTION Some readers are "seasoned" enough to remember the January 6-9, 1996 blizzard on the East Coast (wikipedia). Despite this being among the few high-impact winter weather events of that season, it also occurred in a time period of rapid transition in the Pacific from the previous year's El Nino to the strengthening La Nina of the winter that followed. (See NOAA CPC Special Report) Hmmm...sounds a whole lot like 2011 to us. Should you run through the halls and burst into the Principal's office screaming, "Foot's calling for a blizzard!!" Um, no. Please stay calm, it is only October. Perhaps you can consider scientific alteratives:

THE LONG RANGE DATA SOLUTION: We are saying those with interest in understanding how to follow NOAA data about La Nina, Atmospheric Rivers, should begin familiarizing with parameters that our team and many climate scientists use to identify possible patterns: The Arctic Oscillation, the North Atlantic Oscillation, the Pacific-North American Index, (our usual group) and new data points including Total Precipitable Water.

That is, unless you would rather learn about atmospheric rivers up close and personal from the front seat of your car... (Youtube video from Irene in Vermont).

(Forecast Advisors Foot, Lear and Krichinsky)

Saturday, October 22, 2011

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The Weekly Powderhound Report

8:30 AM 10/22/2011 | And all the snowboarders said, "THAT's what's UP!"  | Even though last week's Midwestern Storm did not produce any snow across the Great Lakes or Upper Plains, it may have started something else of interest to snowboarders, facilities management staff and families alike.  

We hypothesize that off a long range pattern that could lead to "cross Polar flow" of Siberian air in the next 30 days. Why would powderhounds care? Let's just say those planning to enjoy Thanksgiving Weekend near a ski resort might get an extra helping of fluff, and we don't mean the whipped cream on the pumpkin pie. Take a look at the latest snow & ice cover map below from the National Snow & Ice Data Center...

1. SIBERIAN SNOW COVER IN OCTOBER:  Other climate and weather forecasters in addition to us take a wide-angle "Earth Systems Science" look at how Siberian snow cover is the real elephant in the room for predicting North American winters. We can cite numerous examples, the most recent being October 2009, at how this factor was a contributing factor to the historic 09-10 winter in the U.S. 

2. A TALE OF TWO NUMBERS: We've learned from other writers that despite a "blanket of white" expansion of Siberian snow cover in recent weeks, actual depth of snowcover may not be as deep across Siberian and Alaska as in recent years. That said, the increased reflectivity a large snowpack produces chills the boundary layer, allowing Polar Continental high pressure systems to become stronger - and in turn colder. Snow can lead to more cold, and more snow.

3. OK, WHAT DOES THIS MEAN? If snowcover continues to expand and deepen, and multiple strong high pressure systems roll into Northern Canada into Novemer...the first significant winter storm for the Northern U.S. and/or the Mid-Atlantic, could easily get underway by Thanksgiving. 

National Ice Center - Snow cover map:

NOAA Climate Prediction Center - Oscillation data:

WDAZ-8 StormTracker Blog:

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Wet Halloween...White Thanksgiving?

Snow for the 1989 Macy's
Thanksgiving Day Parade in NYC.  
9:30 PM EDT 10/22/11 As the golden days of October wane toward thoughts of Turkey and early season snow, our Winter Stormcast Team have been analyzing long range climate patterns. We have also reviewed NOAA's Winter Outlook* and are encouraged to see reference to the Arctic Oscillation as a factor which will influence 2011-12 winter weather in North America. *Link to summary article by Meteorologist H. Michael Mogil, an Advisor to the U.S. Team of Foot's Forecast and former NOAA/NWS forecaster. 

LOOKING AHEAD TO DECEMBER A detailed analysis and rationale of our early winter forecast will be posted in our new Winter Stormcast Zone in development this weekend. In the interim, we wanted to share some projections for the 6-week period ahead (first outlined on September 30)
  • Wet Halloween? Energy from tropical disturbances in the western Caribbean may develop into a named system and could move into the southern Gulf of Mexico by Friday 10/26. Long range U.S. and European computer models show copious moisture reaching the Carolina/Mid-Atlantic coast just after Halloween. The Midwest, Mid-Atlantic and Northeast may get a dry run at trick-or-treating next Sunday or Monday, but probably not the Southeast.  
  • November Flip-flops: Starts cold then a mid-month warmup, ending cold and stormy. Following the late October coastal storm, another high pressure ridge establishes in the Eastern U.S., allowing an early month cold snap that eventually warms, but could lead to another deep trough moving east by end of the month. We believe this setup is the continuation of a long range pattern initiated by Hurricane Irene.    
  • I"ll be home for...Thanksgiving?: By the 11/18-20 period, the deep trough may move east bringing a strong cold front. Passage of the front would be followed by another cold high pressure dome building south from Canada. We envision very cold air from this dome reaching the Eastern seaboard before Thanksgiving weekend. Any fast moving clipper system could "overrun" the dome, generating a significant early season snowfall by Turkey Day or Black Friday from the Ohio Valley into the Northeast.

TARGET DATE FOR FIRST SIGNIFICANT SNOW: (defined as 4 or more inches of snow for an event, following NWS criteria). Our Winter Stormcast Team has targeted the period between November 25 to December 5 for the first significant snowfall should occur from the Ohio Valley to the Mid-Atlantic and Northeast. Long-time readers will remember what happened for our December 5, 2009 call first made on October 30, 2009. 

THE SCIENTIFIC RATIONALE? We have an extensive report currently posted in several of our Winter Stormcast Zones for the Northeast, Ohio Valley and Western Great Lakes. That report will be reposted in our soon-to-be launched U.S. Winter Stormcast Zone.  For the hard-core scientists among our readers, we have assembled a headache-inducing review of Northern Hemisphere Snow Cover, the Arctic Oscillation, oceanic factors of La Nina, the Pacific Decadal Oscillation, Solar output and a host of other climate teleconnections. *Image (right) from National Geographic Magazine as posted on the website of the North Carolina State Climate Office explaining the Arctic Oscillation.

It takes some time to sanitize all that into a format which won't send running from the computer screaming, (unless it's too late), so check back later this weekend for the full report. (Advisor Mr. Foot, Winter Stormcasters Jason M., Connor M., Nic R.)

Thursday, October 20, 2011

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Fri, 21 Oct 2011 10 AM EDT
The weather is forecast to be dry over much of the nation for the next couple of days. There will be showers, and perhaps thunderstorms in the PNW. The Mid-section and parts of the South will show some chilly, if not freezing, temperatures.

Better weather to race for the cure
(sunshine ahead, wind at your back)

10:20 AM EDT 10/20/11 Passage of the less-than-severe coastal storm, and the spiraling Ohio Valley low literally caused "breath-taking" winds in the upper Midwest over 60 mph and up to 40 mph sustained over the Great Lakes. Our forecasters in these regions, including Ben at Michigan Weather Watchers, and Robert in Southeast Wisconsin, report the storm is becoming "cut off" from the primary flow. This will produce on-going strong wind gusts for the next several days in these areas, coastal flooding along lake shores and a bitter early winter preview... minus the snow.

Some are thankful snow was not associated with this storm. Readers will recall about this time last year, we were heading into what would become one of the most powerful inland cyclones ever recorded in the U.S. It became a powerfully epic storm registering a barometric pressure of 953 millibars, which is on par with a Category 3 hurricane. This storm pummeled the Great Lakes with hurricane-force winds, caused blizzard conditions in the Dakotas, tornadoes from the Ohio Valley to the Southeast, all on the same day. (A Wikipedia overview of the storm we have reviewed for accuracy.)

Fast forward one year, things are looking much better. Despite brisk winds and cold temperatures, Komen Racers everywhere will delight in good news for this weekend's events. Despite the cool weather, races planned around the U.S. are fortunate to be in areas which will be under a high pressure ridge. We are happy to report that Races for the Cure in Kansas, Iowa, Tennessee and Maryland alike should see weather similar to what was observed in the photo above from the Hunt Valley, MD event in October 2010.
By Saturday, winds in the Midwest may still be howling up to 30 mph, but by Sunday in the East, conditions will have diminished to light west breezes. If you've been thinking about joining the Maryland event, there is still time to register...visit Komen's Hunt Valley, MD Affiliate website. Racing in Knoxville, Tennessee on Saturday? Forecaster Jeremy Buckles of our East Tennessee Team has you covered, with better weather ahead for the race.

So with sunshine ahead and the wind at your back, we encourage any able-bodied readers available to take advantage of the improving weather, and make a difference... because "we all know someone" who's faced it. (Forecaster Foot and the U.S. Advisory Team)

Monday, October 17, 2011

We might be in the clear, 
(even though it's dark now)

From the Storm Prediction Center
7:00 PM EDT 10/19/11 Dominant dull grey skies for much of today in the Mid-Atlantic and Northeast, along with a wider-than-expected separation of the two Eastern low pressure systems, may have been among the factors which prevented the widespread severe outbreak we were concerned about. Granted there is still sustained cold winds in the Upper Midwest and Western Great Lakes, which will work to the East by tomorrow. 

The wrap-around  northerly flow behind this storm has produced the first real taste of winter: Portions of the Central and southern Plains are under the first Freeze Warnings of the season. Visit our Affiliates CirrusWeather (Kansas) and ConvectiveWeather (Southern Plains) for a local perspective on the recent severe weather and arrival of cold.

However, we hope most of you in the East are NOT unhappy about avoiding a surprise torrential downpour, or have the atmosphere fail to produce dangerous cloud-to-lightning at rush hour. Additional observations from the NOAA Storm Prediction Center (SPC) provided insight as to why the strong damaging winds they, and our team meteorologists, did not materialize as expected.

Forecaster Jason noted this comment in a recent team collaboration: "(Subtropical moisture at the surface) is what keeping the low levels juicy, I think that warm/moist air is acting as as an inhibiting factor for development. The SPC said this afternoon; 
In short, it is possible that the "primary low stayed stronger, longer" and in doing that, the energy did not merge as expected, hence truncating the chance for several weather.
(Forecasters Foot and Jason M. )

An October surprise no more
Our latest storm updates in Facebook...and in "Eastern" tab.

WISCONSIN  Heavy bands of rain to setup across the region
THREE RIVERS/PITTSBURGH  Clear now but rain arrives after 12
CENTRAL MARYLAND  Hail and strong winds will bump into Baltimore
BAYSHORE  Stormy this afternoon, sunshine returns for the weekend
VIRGINIA TIDEWATER A windswept Wednesday in the southern Bay.
CAROLINAS  Team coverage for Cape Fear & The Outer Banks
SOUTHERN GEORGIA  Severe weather possible this afternoon.
CENTRAL FLORIDA Clearing today to dry out yesterday's flooding rains.


9:00 AM EDT 10/19/11  By now, it's no longer an "October Surprise" but a "Oh man not again"  storm. We think the current setup of an Ohio Valley low pulling in tropical moisture to "phase" with the subpolar jet is beginning to look a lot like a possible Winter pattern. The NOAA Storm Prediction Center (SPC) has identified the Mid-Atlantic with a 30% probability of strong windsWere this storm to occur just 45-days from now, those west of I-95 might be hearing thundersnow, while areas from Eastern North Carolina to the Delmarva and the Northeast feel like Irene "did an Ivan" and cycled all the way back around to make another run up the coast. Our overview of the threats and timing for today, Wednesday 10/19.

Primary threats & storm timing 
We have high confidence this event can produce similar high-impact disruptions to commuters and municipalities as was observed on January 26, 2011 and the recent flooding rain event of Tropical Storm Lee. Remain alert to changing conditions and monitor your local NWS office for any warnings.

1. STRONG WINDS, LIGHTNING, HEAVY RAIN: A digging trough in the Midwest leading to rapid interaction of dry air with tropical moisture from the east may fire surprisingly powerful severe weather today from the Carolinas north to Eastern Pennsylvania. (See Water Vapor). The primary threat for most areas should be heavy downpours. 

*Along and east of I-81 today, including the Richmond-Washington-Baltimore I-95 corridor, 3 PM to 6 PM is our targeted time frame for highest risk of dangerous weather conditions.* 

2. TORNADOES & HAIL  The SPC has also identified a portion of the central Mid-Atlantic with a  5% shot at Tornadic activity. You may think those numbers are low, but for weather forecasters and emergency managers alike, it is enough to raise eyebrows this time of year. Under this scenario, areas of central and eastern Virginia, east of I-81 would be first in line for tornado threats early this afternoon, with the I-95 corridor and east late this afternoon into tonight.

Previous post from 10:50 PM 10/17/2011:

Residents of the Eastern U.S. from the Ohio Valley to the Carolinas and the Mid-Atlantic might have their breath taken away by a little-known surprise lurking in the Gulf of Mexico. We may dub this the "you've got to be kidding me" storm. Believe it or not, this area of disturbed weather currently identified by the NHC with a 30% chance of development...may be pulled into a deepening trough regardless of whether it becomes  Tropical Storm Rina or not. Moving rapidly over land, this system could could reorganize as a "cold core" storm as it bisects the East Coast, and deliver a real punch of wind to millions of folks along the coast who tomorrow might say, "What storm?"

Several notable computer model guidance packages, including the "Hurricane-Weather Research and Forecasting" model, or HWRF (shown left) and the "European" model show some type of fast-moving windstorm slicing through Eastern North Carolina. By Tuesday night, and moving along the DelMarVa penisula by Wednesday. In this scenario, the primary threats will be tidal flooding and strong gusty winds near tropical storm force. Our concern is that because the system is relatively far away, and is not a named storm, there may be a lack of awareness  as to how quickly this system could ramp up if it is pulled into the trough and rides up the coast. 

WIND: Coastal areas from Eastern North Carolina to Southeast Virginia and the DelMarVa may experience sustained winds of 40 mph to 55 mph Wednesday to Thursday morning. Inland areas along the I-95 corridor could see gusts above 30 mph at times. 
RAIN: Latest precip projections from NOAA show a large area of 1.5" + of rain from the I-95 corridor east, with a larger slug of moisture from the primary low in the Ohio Valleyheaviest rain exceeding  is expected in central and south Florida on Tuesday with decreasing amounts the farther north. 
FLOODING  If the storm arrives in an area on a high tide, the strong southeasterly fetch may produce tidal rises of 1-2 feet in coastal communities regions of the Carolinas to the Delmarva.

Even though it is October, a quasi-Tropical system merging with the active energy of the subpolar jet stream? That'll turn some heads, especially if it happens in a span of less than 48 hours. Those of you seasoned enough may remember Hurricane Kate in November 1985, which made landfall in Florida before heading northeast across the Carolinas. After making landfall near Appalachiacola, FL in mid November as a Category 2, the storm went right over the Cape Fear area and exited near cape Lookout. Despite going no farther north, the unraveling storm produced 50 mph winds as far north as Salisbury, Maryland.  I know, because I was there to see it and boy was that ever a surprise. This time we want you to know about it earlier than the day before it happens. (Inset: Hurricane Kate track, slide show)

We would encourage our readers, along with local emergency management officials, facilities & operations staff to keep close watch on your NWS forecast office, as well as the NHC for any surprise developments with this system. 

(Forecaster Foot and Connor M., Baltimore MD)