Much cooler, yet still so warm |
| Posted: 1/07/2007 09:01:00 AM |
 While the list of records in the eastern US could fill 10 pages, I'll give you the Keene version:
Yesterday, the high temperature in Keene reached an unpresidented 68 degrees Farenheit. This completely demolished the old record of 58 degrees for January 6th. It also broke the old monthly record for January of 65. And to top it all off, it tied the all-time record for the highest temperature ever recorded during the meteorological winter (DJF) in Keene.
All in all, it was an extremely warm day. The recorded high of 68 was more towards the average for May, and the low temperature of 45 resembled what you would normally see during an average June morning. The 68 degree reading was 36F above normal, and the 45 degree reading was 33F above normal.
Master list of records courtesy of EUSWX
Today, we will see temperatures much cooler than yesterday. However, the forecast high of 50, while 18 degrees below yesterday, will still be 21 degree above the average high! Tonight, temperatures will fall into the low 30's (20 degrees above average) as clouds push in from the south and the west.
Precipitation will enter the region around midnight, and that will officially begin another chapter in the meterological book. Cold air at this surface will allow for a mix of snow, sleet, and rain at the onset. Icy precipitation will continue through daybreak, before changing to plain rain by 7 or 8am. At this time, no significant accumulation of snow and sleet is expected, however a coating of wet snow and/or a glaze of ice to hamper the morning commute Monday, is not out of the question.
Rain will continue through Monday afternoon. Due to the location of low pressure (currently entering Alabama), large amounts of moisture from the Gulf will be transported into the region Monday morning. Rain could fall heavily through 10 or 11am. Flood Watches have been issued for much of the Mid Atlantic region. There may be visibility issues as well for the morning commute due to the heavy rain and also the potential for foggy areas. Another issue with this storm is thunder activity. While it is not a threat here in Keene, thunderstorms, some severe, could threaten the MA into SNE through Monday afternoon. In addition, two rounds of high winds are expected across the region. First one tonight as the storm winds up to our west, and the second one Monday night as the storm pulls out. The second one looks like it will be the strongest, with cold advection moving in from the north and west. Wind advisory potential exists for both events. First one, not so much here, second one should encompass all of SNE.
Colder air moves in on Tuesday. Highs will stuggle into the 30's and with gusty winds continuing, it may seem cold to most people, but remember that the average is 28 so we will still be at least 5 degrees above normal.
Wednesday will be even colder with highs around 30 or low 30's for SW NH. We may even reach average or EVEN duck BELOW average! The last time we saw below average temperatures was the 29th. That is also the ONLY day we have seen below average temperatures since the 9th of December. Some places in SNE did not stay below average on the 29th and in fact yesterday, extended the continuing streak to 27 days of above average temperatures.
While high temperatures will have their moment, lows will continue at least 5F above normal through this week. Thursday, temperatures will start to rebound back to near the 2006-7 winter norm of 45 (15 above the actual average). On Friday, we may indeed reach that level once again with highs in the low to mid 40's. Another storm system, a western storm, will move into New England Friday Night, spreading precipitation over the area through Saturday. With a large amount of cold air in southeast Canada, this next storm could tap that air mass, allowing for wintry precipitation into the weekend.
There is a significant amount of uncertainty with this next system as well as the pattern to follow. This is where our long term pattern change comes into play.
The AO has reached an incredible maximum during this warm period. The ensembles forecast points to the a significant drop, however, there is usually a bias towards a neutral solution. For now, the AO is just going to be stubborn one, keeping all the cold air locked in Canada. Not until a drop similar to the forecast occurs, will we be able to see true winter conditions any time soon.
The NAO has remained positive for the past 11 days, but has also stayed weaker than previously forecasted. The ensemble forecast is a slow trend closer to neutral. This will allow for another period of blocking to develop in late January and early February. The blocking that occurred in December was actually very strong (even compared to October), but also a solid 30 degrees further east than would be preferred for a winter set up. The upcoming pattern is unfortunately forecasted to be similar to the December situation per the GFS ensembles:
So the main thing to watch for during the next week is for a shift westward.
The PNA dove into the negatives during this warm period, for the first time since the infamously warm November. December, the PNA remained positive. This would normally support colder conditions across the eastern US, however due to a positive AO and NAO, we remained on the mild side, and the only affect the +PNA had was warmer temperatures in the midwest as well. The GFS ensemble forecast is a return to neutral or positive conditions, but this will have little affect if the AO remains so positive.
Summary: everything rides on the AO.
Recently issued is the December 06 data:
I'll post the temperature analysis for Keene later this afternoon.
|posted by Sam Lillo @ 1/07/2007 09:01:00 AM 
|
|
|
