Friday, February 13, 2004


FRI-SAT WEEKEND UPDATE: "HOUSTON....WE HAVE A PROBLEM."

- Jim Lovell, Apollo 13

This is being written Friday late evening as the newest computer models have just come in and are being digested by forecasting agencies around the country. When Paul Kocin (the guy with the gravelly voice) goes on the Weather Channel to say there is a risk of a significant event with frozen precipitation, you know it's serious.

I will not have a chance to analyze the situation again until Saturday afternoon. So if you are reading this then, it's a good bet the cat will be out of the bag by that time. I hope this does not become a case of double reverse negative, where I have to back off on backing off. But here's what is shaping up... it's a classic case of Dejavu all over again.

SO WHAT'S THE PROBLEM?

1. I am going to have to re-un-backpedal on my earlier statement that there would NOT be a big storm this week. It looks as though what I said below about "I hope I don't have to come back on this site and throw out everything I just said" is true. We ARE probably going to get a big storm this week.

2. We may be looking at a classic 1979 style storm setup, only this time, we know it will happen instead of being a surprise for millions of people. After the warm weather on Saturday, it'll probably still be a surprise anyway. Three of the major computer models are now converging on a solution that produces a major winter storm on the Mid-Atlantic coast Tuesday night. The reason why is below:

3. The northern stream is delivering a super cold arctic high on Sunday. As was projected on this site, the high is not going to move out as fast as originally thought. Secondly, the remnants of the high that was sinking into the Gulf is helping to create a ridge of COLD air from the south to the northeast.

4. What I didn't realize until today was that when you get the effect of an arctic high to the north and a modifying cooler high to the south in Texas, the Pacific stream coming across Mexico is deflected under the Texas high. But when the northern high begins to depart, it not only is going to leave behind that classic signature of COLD AIR FILTERING DOWN THE APPALACHIANS, but the clockwise flow coming off the ocean noses the jet stream back in towards the coast.

5. As that happens, moisture is drawn into a wedge between the two highs, naturally producing a low. This follows the old adage we use in my classroom all the time... "air always flows from high to low."

So the official word is that everything I had discussed in earlier posts is being resurrected. Go to the archives on the left and read the post starting after "FABULOUS FEBRUARY" and the description for "Storm #1" also please my analysis of this storm as compared to February 1979. It looks as though it all may come true after all.

A SUMMARY OF WHAT WE ARE POTENTIALLY FACING IF THIS ALL PANS OUT:

- If it is snow, areas from DC to Philly are looking at 5-10 inches Tuesday night and most of Wednesday.
- Snowfall rates will be several inches an hour at the height of the storm.
- School will be closed Wednesday and possibly Thursday depending on snow amounts.
- A brief warm up will follow the storm, accelerating snowmelt but causing refreezing at night.
- If it is rain, it will be .5 to 1.0 inches of fast-falling, wind-driven rain over 12 hours.


So to lighten the mood a bit as we head into the next winter adventure, here are more "Tips for Reducing Winter-Related Stress"

7. Despite what you may hear on TV, if bad weather is approaching, there is no real need to stock up.
Granted, people had to stock up in the past - say, in 16th-century France - because there were no 7-Elevens. There weren't even any Giants. Today, a wide selection of food stores are usually close by. This explains why folks today don't have root cellars and why they don't keep 50-gallon barrels of salted cod tucked under the stairway. Fresh food is readily available, the experts say. A warning: In isolated instances, due to inclement weather, you may have to leave the car at home and walk to the store.
On the bright side, it's a story you'll be able to tell your grandchildren.

6. To be posted on Saturday.

In conclusion... here's a roundup of what area NWS offices are saying behind the scenes. And oh by the way, we are at the proverbial 5 days before the storm. Guess what the NWS forecast is for Philly or Baltimore on Wednesday? Partly Cloudy, 40 F.

Baltimore NWS: "MODEL GUIDANCE REMAINS UNDECISIVE ON HOW MUCH AMPLIFICATION OCCURS UPSTREAM AND HOW STRONG THIS SYSTEM IS LIKELY TO BE. THIS SYSTEM WILL HAVE TO BE WATCHED CLOSELY NEXT FEW DAYS.

Philadelphia NWS: "LOW PRESSURE IS FCST TO DVLP OFF THE CAROLINA COAST MID WEEK AND MOVE SLOWLY NE. THIS STORM WILL HAVE TO BE WATCHED CLOSELY AS IT WILL BE DEEPENING AND GOING VERTICAL WITH THE UPPER LVL SYS."

Raleigh, NC NWS: "OF NOTE FOR TUESDAY'S EVENT...18Z RUN OF THE GFS HAS COME IN MUCH DEEPER WITH THE LOW OFF THE COAST...DEEPER BY 14 MB FROM THE 12Z RUN VALID AT 12Z WED...IT NOW SHOWS A COASTAL BOMB TUESDAY NIGHT. "

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