Friday, December 15, 2017

The last time this happened

The last time this happened...
(in 2007) it did not end well.

5:30 AM Fri 12/15 - Winter Weather Advisories are posted for portions of the DC-Baltimore-Philadelphia metro regions starting at 1 PM. 

With road, air and upper level temperatures all in cold tandem, it is highly probable that any precipitation this afternoon in these regions will:
  • Fall as fine-grained snowflakes and freeze on contact with the surface;
  • Produce slippery road conditions within 30-60 mins of snow onset;
  • Cause widespread hazards during the afternoon and evening commute;

Today may be the first time since February 2007 the Baltimore region faces a decision on whether to wait for "ground truth" or pre-empt the weather with pre-announcements on the afternoon schedule. We were there for that event, and it did not go well for anyone reading this page. The comments from 10 years ago tell the story.

GFS model precip projection for 7 PM tonight.

Solutions over problems
or as Luke Skywalker has said,
"this (winter) is not going to go the way you think!"

image credit:

Sunday, October 29, 2017

Why Can Autumn Tell Us About Winter?

Recent weather patterns across North America may signal
how winter begins in the Mid-Atlantic and Northeast. 

7:50 AM 10/29 - Part One of our story is to unpack how large scale influencing events in the past month may be setting in motion a pattern for first half of winter. 

Looking for something more intriguing and original? You'll have to read on to discover Part Two. We are introducing findings by high school student investigators who have uncovered surprising connections about the secrets winter has in store for us. 

PART ONE: To set the story, a look back at October:  

1) The long periods of above normal warmth in the west, evidenced by the widespread devastating wildfires that were preceded by 100 F+ temps in San Francisco;

2) The hard freeze in the central plains and deep south, with freeze warnings as far as central Alabama his weekend;

3) Prolonged warm and dry conditions in the East, interrupted by occasional cool spells.

Temperature-wise, the past month has played out a lot like what the next month is projected to do, according to the NOAA Climate Prediction Center's 3-4 week experimental outlook. The scenario we see unfolding as we turn the page to November:

Sunday, October 8, 2017

A Return To Normalcy? Not For A While.
  • RAIN RELIEF IS NATE'S FATE: Remnant moisture and wind from T.S. Nate overspreading the eastern third of the U.S. will reinforce the summer-like pattern seen in these areas since late September. The upside will be a welcome relief of rain to many dry areas baked in the recent warmth. See below for 7-day precipitation projections.
  • TEMPS STAY WARM: Long range temperature indicators show above normal temperatures for the mid-south, mid-Atlantic and northeast should continue through much of October.
  • BERMUDA HIGH HOLDING: As shown in the steering currents image from University of Wisconsin, the clockwise spin of air in the west Atlantic is maintaining a moist, tropical hold on the eastern U.S. while allowing Nate to fuel the fire even more with an infusion of fresh Gulf moisture into the pattern.

7-day rainfall projections from NOAA

What it all means?
Expect a warm, wet pattern through mid-October, returning to dry and windy toward end of the month. Unless of course the Gulf sends along another hurricane. 

Saturday, September 23, 2017

1 comment:
"How do you solve a problem like Maria?"
- from Maria in the Sound of Music

  • WESTWARD SHIFT: Computer model trends past 24 hours are depicting a significant westward shift in Maria's track toward North Carolina's Outer Banks. 
  • CONE OF UNCERTAINTY: The National Hurricane Center's official track has also moved notably west, from solutions earlier this week that were all out to sea.
  • EXPANDED EFFECTS: A strong and large but slowly weakening tropical system results in an expansion of the wind field. A wider area will experience tropical-storm force winds than if the storm was very strong with a tightly-compacted wind core.
  • IMPACTS FOR MID-ATLANTIC COAST? Coastal communities from South Carolina to New Jersey will experience 72+ hours of large and increasing swells, persistent onshore easterly winds, water levels rising with each tide cycle and probable flooding in low-lying areas. 

Tuesday, September 12, 2017

Jose Surprise?
  • ATLANTIC WANDERER JOSE, ONCE A CATEGORY 4, now looping in the Bermuda Triangle before expected to turn toward the Southeast coast this weekend.
  • Long range show that a high pressure ridge over E Canada & northeast could move into North Atlantic late next weekend. Ensemble models below largely depict an out to sea solution.
  • Development of a deeper trough in western U.S. same time period could either nudge Jose away from land, or help create a channel with the ridge, driving the storm northwest. 
  • We will continue monitoring for indications for / or against this scenario.

Saturday, September 9, 2017


1 comment:
Tampa: Could this be the one?
  • MULTI-CITY LANDFALL on Florida's west coast while areas of east and Space coast receive 100 mph winds. The Nature and Gold coast cities likely to see winds of 100-120 mph include Naples, Fort Myers, Port Charlotte, Sarasota,Tampa-St. Petersburg, Clearwater. 
  • 3/ 4 of  FLORIDA PENINSULA likely to receive winds 75 mph or greater, per NOAA.
  • SUMMARY OF OFFICIAL DETAILS: See our Hurricane 411 Center.

6:00 AM ET SAT 9/9 Westward shift in track took place overnight as has been the trend, resembling the scenarios early this week of a west coast landfall as a major Category 4. These impacts would mirror the 1935 Labor Day Hurricane, 1960 Hurricane Donna and Tampa's last major direct hit in 1921 (1-min video) that produced 6-12 feet of surge in the Bay. View Surge Maps for Tampa inundation levels at Category 3, 4 and 5.

Below is the forecast position for 4 AM Monday 9/11 by the European, of which NHC has indicated their path is mirroring. A docu-drama video scenario developed by the Tampa Bay Catastrophic Plan Project shows how a Category 5 strike would play out were that to occur. Even if not a Cat 5 at landfall, it won't matter. Impacts from this path would essentially be the worse case scenario if the storm restrengthens after leaving Cuba.

What this map means: 
  • A Category 3 hurricane with 120 mph winds channels directly through Tampa Bay
  • Previous 175 miles of coastline and interior sections of West Florida will have just experienced a Category 4 storm with damage far exceeding Donna and the 1935 storm.
9:50 PM ET FRI 9/8 If major westward shifts occur in the official track at this point, Tampa-St. Petersburg could be looking at "the one" they've been fearing for years...a Category 3/4 monster with a 12 foot+ storm surge that inundates the entire downtown and leaves St. Petersburg an island.