BREAKING NEWS! -1700-
The streak has ENDED! As I had thought earlier, high pressure today was greatly underestimated. The recorded high temperature for today was just 28 degrees. This is the first time since the 8th that the high temperature has been below 30. In addition, the average high temperature for today of 34 was not met, in fact the actual high was 6 degrees below average. This is the first time since the 9th of December that the high has been below average. So the streak ends at 19 days.
Update for tonight: Despite a chilly high for today, current satellite shows a cloud shield moving in quicker than expected. My previous forecast of 14 may be a bit low. Current thinking is 16 by tomorrow morning.
Also, snow for tomorrow. The NWS has upped POPs to 60% for Cheshire County, and has included snow accumulation of 1". The point forecast has 1 - 3". The 3 inches probably wont happen, but we may indeed see accumulating snow for the first time this season. My first forecast map has been included in the winter weather outlook page.
The streak of warmth may be coming to an end shortly! Well, it will be a close call. High temperatures today should bring us to 20 straight days of above average high temperatures, however tomorrow is the big question. My current forecast has Keene no higher than 32 tomorrow afternoon, and the average high for 12/30 is 33. As said, big time close call for the life of the heat streak.
Moving back a step, a cold front cleared the region this morning, bringing temperatures down around 20. Today looks like another beautiful day, similar to yesterday except for temperatures 5 to 10 degrees lower. Tonight, clear skies will allow temperatures to take a nose dive. We may in fact see low temperatures below average for the first time since the ninth as well. Currently the forecast low is 14 for tonight, NWS is at 12, and the average is 14. Another close call.
Tomorrow, the weather gets a little interesting. We will have average temperatures in the area for the first time since we came close (within 4 degrees) on the 22nd. Clouds will move in Saturday morning in association with a short wave disturbance. A chance of precipitation will move into the region, and with temperatures at or below freezing, we could have genuine, no mix, snow! There is a slight possibility of an inch of accumulation especially in the higher elevations. Otherwise, a light dusting is likely through Cheshire county tomorrow. Snow should wrap up before nightfall. Low temperatures will range around 20.
If we get past Saturday with the streak of warmth still alive, Sunday will only continue it. Temperatures Sunday will rebound under mostly sunny skies into the upper 30s. Overnight temperatures will drop into the low 20s, with increasing cloudiness towards dawn.
New Years Day, ice will be the rule. The resulting track of the storm will play a huge part on Monday. The more easterly it positions itself, the more likely we will see a significant icing event. The 06z run of the op GFS has us at a storm QPF of over 1.5 inches. This is promising for a noteworthy storm. The models QPF are close to a consensus, so precipitation type is the focus of the forecast. Right now, the GFS (which is not the model of choice at the moment) pulls this storm up a good 500 miles or more east of the other model solutions. The NAM, which is not exceptionally great at over 60hrs, has the low pulling into Illinois at 84hrs, with precipitation far out in front. It also has the 850mb 0C line a solid 200miles north of the area. Current thinking is that the models are underestimating the strength of the high over the region. Currently, high pressure is located in southern Quebec. This high will be responsible for some wintry temperatures tonight. The short wave will push the high out of the region tomorrow, then another area of high pressure will take over on Sunday. If the high is stronger than currently progged, cold air at the surface will be able to stick around longer translating into a prolonged period of ice rather than a change to rain in the afternoon Monday. The ECM is the current model of choice for this storm. Below is the 5-day forecast valid 12z Tuesday. As you can see it brings the low into the Great Lakes region. The 500mb thickness is 5520m. We would need to see closer to 5400m to be confident on a major icing event.
New Year's Day is 72 to 96 hours out right now, so while confidence is growing on an ice storm, the details still have yet to be worked out. Here is my current forecast:
Moving into Monday Night and Tuesday, the storm will lift north and east of the region allowing precipitation to come to an end early Tuesday afternoon. Precipitation could fall in the form of snow Tuesday morning before ending. No snow accumulation is expected from this storm, however sleet accumulations over an inch could occur, in addition to ice accretion over a tenth of an inch. These estimates are just from considering the minimal impact of the storm. Significantly higher ice accretion is quite possible if all the factors come together. Whatever is the case, this storm is definitely advisory material and quite possibly warning material.
Historical look: This storm will occur about a week on the calender before the 1998 record-breaking ice storm immobilzed much of the northeast and Quebec. That storm came during one of the strongest El Ninos on record and after a very warm December. While an ice storm such as that one is no where near possible. It is interesting to look at the similar situation that happened 9 years ago.
Wednesday and Thursday will see dry weather and temperatures back up into the mid to upper 30s with overnight lows around 20. The pattern change bringing colder air into the northeast by late January is still looking promising. See yesterday's post for details.
Climate information:
CLIMATE...AS MENTIONED IN A PREVIOUS AFD...RECORD LATEST 0.5 INCH
OF SNOWFALL IN ANY SEASON AT WORCESTER WILL BE BROKEN TODAY...WITH
JUST 0.4 INCH SEASONAL TOTAL RECORDED AT THIS TIME. THE PREVIOUS
RECORD LATEST DATE IS DECEMBER 28 1990. THE LATEST FULL INCH OF SNOW
AT WORCESTER IS JANUARY 4 1973 AND 1941. DATA IS INCOMPLETE BETWEEN
THE YEARS OF 1997 AND 2001.
|posted by Sam Lillo @ 12/29/2006 07:58:00 AM
