textproduct: Caribou

WHAT HAS CHANGED

- Updated aviation discussion.

KEY MESSAGES

1) A Noreaster will continue to impact the region with much of our area impacts in Downeast Maine through Tuesday AM; bringing breezy NE winds, and periods of rain.

DISCUSSION

KEY MESSAGE 1...A Noreaster will continue to impact the region with much of our area impacts in Downeast Maine through Tuesday AM; bringing breezy NE winds, and periods of rain.

KEY MESSAGE 1 DESCRIPTION... The center of low pressure (at 1004mb) associated with this Noreaster is beginning to drift NE this morning. As of 1AM EDT the center was approx 50mi east of Ocean City, NJ and drifting NE as it begins to get picked up by the westerlies. A large occlusion is wrapped up to near Cape Cod with a triple point near Georges Bank. Satellite imagery is showing moisture advecting north in Maine from the the Atlantic which extends back to the Bahamas. This has increased PWATs over Downeast Maine into the 175-200 percent of normal range for late September. This system is nearly vertically stacked with the 500mb low aloft and a significant amount of dry air has worked into the Gulf of Maine noted by GOES-East 7.34um water vapor imagery. A large blossom of precipitation north of the triple point over the Gulf of Maine is pushing into the Downeast at this update. This is associated with an area of upper level divergence increasing surface convergence which has resulted in an area of positive 1000-925mb frontogenesis. This has resulted in moderate to brief heavy bursts of rain in Downeast Maine. Latest RAP Mesoscale Analysis data suggests 250-400j/kg of MUCAPE over the Gulf of Maine waters may advect into the area. Have opted to add isolated thunder to the forecast for the next few hours with this blossom of precip over the waters and Downeast coast to near Bangor region.

At the same time a strong 1028mb high pressure system sits over Eastern Quebec near Labrador with a 583dam 500mb ridge. The placement of the ridge and North Atlantic low pressure near Greenland is preventing this Noreaster from moving too fast at this point but the ridge is collapsing which is allowing this cutoff Noreaster begin to return into the westerlies and getting pulled north thanks to an approach trof in Ontario. The global models and hi-res guidance is in fairly good agreement for today. The approaching trof in Central Ontario will begin to pull the Noreaster in a NE direction over Southern New England this afternoon and cross the Gulf of Maine waters tomorrow and exit east of Nova Scotia on Wednesday AM. The surface low today will continue to slowly weaken and then weaken to a 1011mb low over the Gulf of Maine tomorrow and 1015mb by Wednesday AM. Here is what to expect for the various components of the storm:

Periods of Rain...The forecasting challenge today is noted via the hi-res CAMs and globals on how to handle all this dry air wrapping into the system. Current thinking is the placement of upper level divergence keeps the CWA in a favorable area for surface lift and therefore periods of light to moderate rain today favoring the southern 1/2 of the CWA. However, by late in the day light rain likely to reach portions of Northern Maine but significant uncertainty with how much stays together running into the surface high dry dome to our north. Confidence is high enough to keep chance to likely POPs across the area today with highest POPs from the Central Highlands southward to Downeast coast. But do not be surprised if there is a period of dry conditions with just low clouds until another area of rain rotates over any particular location. Unfortunately event total precipitation has trended down once again with this forecast update. Looking at event totals (through Tue AM) of 0.6-0.8 inch for areas from Dover-Foxcroft to Danforth and points southward. An area of 1-1.5 inch possible from Bangor to Bar Harbor thanks to this mornings heavier precip. Moosehead Region to Baxter to Houlton only looking at 0.3-0.5 inch totals and north of there to the St. John Valley just a Trace to 0.25 inch possible. Tons of uncertainty with Northern Maine thanks to the dry air this system has to continue to fight through. We do not expect any flooding concerns anywhere given the D1-D3 drought conditions. In fact nearly all of the rainfall will likely be absorbed into the near surface ground and very unlikely any water gets into the rivers and streams. Rivers and streams are currently in the 1-15th percentile range with many approaching top 5 lowest flows on record.

Breezy Winds...As the low pressure weakens today into Tuesday the pressure gradient between the Maritimes high and this Noreaster continues to weaken. NE winds today mainly for the Bangor Region to Downeast coast may gust 20-25mph especially this morning with some gusts to 30mph on the islands and Downeast coastline exposed to the NE winds across the open waters. We don't anticipate impacts from the wind other than maybe a very few isolated power outages Downeast.

Surf...Near-shore breaking waves this morning of 4-5ft will continue to slowly subside today and be down to 3-4ft this afternoon. Although the waves are not as high as past couple days any waves hitting the rocks can present a danger to people on the rocks. Stay away from rock outcrops along the shoreline exposed to ocean waves, as waves can easily sweep people into the cold ocean water which is currently 53-57F.

AVIATION /12Z MONDAY THROUGH FRIDAY/

Today...Across Aroostook county terminals, generally VFR through late morning/early afternoon with rain approaching KHUL later this morning. VFR/MVFR later this afternoon with rain lifting northward. Across Downeast areas, IFR/LIFR with occasional rain. Across northern areas, northeast/east winds 10 to 15 knots. Across Downeast areas, northeast winds 10 to 15 knots with gusts up to 20 to 25 knots.

Tonight...Across northern areas, MVFR/IFR occasional LIFR. Across Downeast areas, IFR/LIFR. Occasional rain regionwide. Northeast/north winds 5 to 10 knots with gusts up to around 15 knots.

Tuesday...MVFR/IFR early with -RA becoming MVFR/VFR in the afternoon. N-NNE winds 5-15kt.

Tuesday night to Friday...VFR/MVFR possible Friday with rain showers at Northern terminals. Light and variable winds turning SW at around 10kts by Thursday.

MARINE

Intra-Coastal Waters...A Small Craft Advisory remains in effect through 2PM this afternoon. NE winds 15-20kt with gusts up to 30kt and 8sec period S-SE swells 3-5ft. Winds/seas expected to fall below SCA criteria later this afternoon. Periods of rain through Tuesday AM may reduce vsby to 3nm at times. Winds expected to be less than 10kt from Tuesday PM into Thursday with potential gusts to 20kt returning Friday. Seas generally 1-3ft Wed-Fri.

Coastal Waters out to 25nm...A Small Craft Advisory is in effect until 2AM Tuesday. NE winds 15-25kt with gusts up to 30kt and 8-9sec period S-SE swells 5-8ft. Periods of rain through Tuesday AM may reduce vsby to 3nm at times. Expecting winds/seas to fall below SCA criteria late tonight into early Tuesday AM. Winds generally less than 15kt for Wed-Thu and then back near 20kt for Fri. Seas generally 2-3ft Wed-Fri.

Waters 25-60nm...NE Winds gusting up to 30kt today. 7-8sec S-SE swells 8-10ft this morning subside to 6-7ft this evening. Periods of rain through Tuesday AM may reduce vsby to 3nm at times. Winds fall below 20kt late tonight and remain below 20kt through Thu Eve then may gust up to 25kt on Fri. Seas 4-5ft on Tue then 2-3ft for Wed and Thu with 3-4ft for Fri.

CAR WATCHES/WARNINGS/ADVISORIES

ME...None. MARINE...Small Craft Advisory until 2 AM EDT Tuesday for ANZ050-051. Small Craft Advisory until 2 PM EDT this afternoon for ANZ052.