textproduct: Gray - Portland

SYNOPSIS

Blustery weather and cool temperatures will continue today, although mountain snow showers will gradually come to an end. There will be some steady improvement in daytime temperatures as high pressure builds towards the area, but it will also make for ideal conditions for overnight temperatures to get quite cold. Wednesday night in particular could be very chilly across the region. Some single digits are not out of the question in the northern valleys. The next chance for widespread precipitation will arrive late Thursday into Friday.

NEAR TERM /THROUGH TODAY/

Cold advection regime continues thru today. That will mean plenty of upslope clouds...and at least thru sunrise upslope snow showers bringing accumulating snow to the high peaks and upwind areas.

With the air mass slowly but steadily drying out...I anticipate that cloud cover will not be as widespread as yesterday. So while cold advection keeps temps near to below normal...temps should be a few degrees warmer than yesterday south of the mtns with some sun. Otherwise it will still be breezy...with 25 to 35 mph gusts at times.

SHORT TERM /TONIGHT THROUGH 6 PM WEDNESDAY/

Continued drying of the air mass will allow clouds to begin lifting and scattering out in the mtns. Any remaining snow showers will also start to trend towards flurries at best.

Cold air advection linger into Wed...so temps will remain near to below normal. But by Wed high pressure will be nosing in from the west and winds should be noticeably lighter.

LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/

05Z Forecast Update: Little change in the latest run of the National Blend of Models (NBM). Strong radiational cooling is likely Wednesday night as a ~1025 mb high crests over the region. Lows will range from the teens across the north with low-mid 20s elsewhere. A few northern valleys may approach the single digits. After a dry day on Thursday, precipitation chances look to increase Friday into Friday night. There could be some mixed wintry precipitation at the onset early Friday morning but significant uncertainty exists at this time range. Drier conditions will then likely return this weekend with near avg temperatures.

Previously... Key Messages: * Expect a very gradual warmup into the weekend but temperatures generally remain below average to average for this time of year. * The next widespread chance of precipitation comes Friday through Friday night, but impacts continue to look fairly low. Details: We transition to nearly zonal flow aloft Wednesday night into Thursday as the ridge axis to our west continues to deamplify on it's approach. A weak shortwave moves through on Thursday but most of the forcing remains well outside of our forecast area so we should remain mostly dry as high pressure is slow to move out to the east. Highs on Thursday will be similar to Wednesday but maybe just a touch warmer over the higher terrain.

We switch back to southwest flow aloft Thursday night into Friday as the next longwave trough approaches. This system will lead to our next widespread precipitation chances Friday through Friday night, but it continues to look relatively low impact given the progressive nature of the trough. NBM 24-hour QPF probabilities suggest medium chances for liquid totals of at least a quarter inch and low to medium chances for liquid totals greater than a half inch (and the higher probabilities are mainly over the mountains and foothills). Precipitation type appears to mainly be rain outside of the higher terrain but some snow will be possible in the mountains. However, at this time, NBM snow probabilities for totals over an inch only max out around 20 to 30 percent. Friday may end up being our warmest day of the long term with highs ranging from the 30s and lower 40s across the north, to the mid to upper 40s elsewhere. A few lower 50s will be possible over southern New Hampshire and coastal areas.

Upper low moves farther north into Quebec and eventually the Canadian Maritimes Friday night into Saturday as the trough continues to move east. A few wrap around snow showers will be possible through the rest of the weekend as we remain in cyclonic flow aloft with various weak waves moving through into the start of the next work week.

AVIATION /05Z TUESDAY THROUGH SATURDAY/

Short Term...Widespread VFR conditions expected south of the mtns. To the north lingering MVFR CIGs are anticipated thru the first part of today...with gradual lifting and scattering into the afternoon. Winds will remain gusty and surface gusts of 25 kt will be possible at all terminals. High pressure building towards the region tonight into Wed will allow winds to slowly diminish the rest of the period.

Long Term...VFR conditions are likely through at least Thursday evening. A return to widespread precipitation chances then could lead to some restrictions Friday and into Friday night. Conditions should then improve again this upcoming weekend as high pressure returns.

GYX WATCHES/WARNINGS/ADVISORIES

ME...None. NH...None. MARINE...Small Craft Advisory until 1 PM EST this afternoon for ANZ150>154.