Area Forecast Discussion
Issued by NWS Caribou, ME

Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KCAR 251314 AFDCAR Area Forecast Discussion National Weather Service Caribou ME 914 AM EDT Wed Apr 25 2018 .SYNOPSIS... Low pressure will approach from the southwest today into tonight and track across our region on Thursday. The low will lift north of the Maritimes Thursday night. && .NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
Update 9:15 AM: Hrly temps were adjusted to fit the current conditions. Dewpoints needed to be a raised a few degrees from the previous package. High cloudiness over the CWA attm per the obs and latest visible satl imagery. 12Z CAR sounding showed dry conditions below 500 mbs. So, the latest timing of rainfall still looks pretty good attm. Higher dewpoints will help to aid in increased snowmelt and runoff to streams and rivers. Previous Discussion... Strong high pressure is currently moving into the Atlantic well to the east of the Gulf of Maine. At the same time low pressure is developing over the Carolina`s and moving northward. This low will continue to move northward during the day today and then across the western portion of New England late Tonight into Thursday Morning. The low is also expected to combine with a strong upper level low approaching the region from the west. The system is expected to produce some heavy amounts of rainfall across southern areas, especially coastal and interior Downeast tonight. For QPF amounts have used a 50/50 blend of the Nam and Gfs.
-- End Changed Discussion --
&& .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... By Thur morning expect sfc low to be centered squarely ovr New England with fetch of deep moisture feeding into CWA. PW values wl climb to 2-2.5 SD abv normal with progged values of 1-1.25 inches acrs the region. Upr lvl system eventually closes off into compact s/wv Thur morning as it heads twd coastal Maine in the aftn. Strongest LLJ wl lkly occur acrs Downeast areas bfr the start of the short term pd with winds aloft gradually weakening thru the day. As compact upr lvl low and assoc cold pool rotates thru in the aftn cannot rule out threat for thunder with elevated instability but hv not included in fcst attm. By 00z Fri expect s/wv wl be located along the and wl quickly eject northeast and out of the CWA by 06z. Shwrs wl linger acrs the far north as wv pushes east but wl gradually come to an end aft 06z. Flow aloft bcms zonal briefly bfr quickly bcmng sw by Fri mrng. This allows highs to climb into the 60s once again at all locations but coastal areas where onshore flow wl keep temps in the 50s on Fri. Clds wl increase in the aftn as next system mvs north fm the mid- Atlantic states. && .LONG TERM /SATURDAY THROUGH TUESDAY/... Long wave trof expected acrs ern conus at the start of the long term pd as 576dm ridge builds thru the Plains. Fri night wl feature system mvg north out of the mid-Atlantic and spreading showers back into the state Fri night and thru the day Sat. Showers wl wind down fm south to north Sat night into Sunday. Cldr temps wl filter in on Sunday in wake of cld front with H8 temps dropping blo 0C per med range guidance. This lkly to keep temps blo normal with highs arnd 50F acrs the north and l/m 50s for Downeast. Not expecting much improvement on Mon as warm advection does not kick in until evng with temps lkly warming to abv normal values once again on Tue with hipres sitting off of the southeast coast. This pattern wl feature upr lvl ridge along the ern seaboard thru mid- week tho guidance diverges on amplitude of s/wv dipping into the upr Midwest by the vry end of the pd. && .AVIATION /13Z WEDNESDAY THROUGH SUNDAY/... NEAR TERM: Expect VFR conditions today. IFR conditions expected in all areas by late tonight. SHORT TERM: IFR expected Thu morning into the afternoon hours at all terminals. May see improvement to MVFR across the south late in the day and eventually VFR in the evening. Expect improvement across the north to MVFR toward daybreak Fri then becoming MVFR by morning. Another round of restrictions wl move south to north Fri evening with IFR conditions possible at BGR and BHB into Sat morning and into northern terminals Sat afternoon before improving to MVFR and eventually VFR. && .MARINE... NEAR TERM: Have used a 50/50 blend of the Nam and Gfs for sustained winds. Currently sea surface temperature is around 41F, so winds could be further suppressed as an inversion develops later tonight. For Waves: Currently the primary wave system consist of southwesterly wind wave (3-4 feet/5-6 seconds. This is expected to slowly subside during the day today, however a new fetch will develop across the Gulf of Maine late today into tonight and extend well into the Atlantic. Southeasterly wind wave will build to around 8 feet/8-9 seconds by late tonight. Total Water Level: With southerly flow developing tonight expect ESTOFS Storm surge to perform best with 0.70 to 1.00 surge late tonight. Astronomical tides are well off highs of month so no coastal flooding or wave overtopping is expected. Will increase Base Tide Anomaly to 0.80 late tomorrow as currents in Gulf of Maine are disrupted. SHORT TERM: SCA ongoing Thu morning wl lkly need to be extended thru the end of the week. Wind gusts wl be marginal on Thur and then drop blo 25kts late Thu night. Expect areas of fog to reduce visibilities Thur morning. && .FIRE WEATHER... Maine Forest Service had reported numerous small fires with dry conditions yesterday. Todays and tonight`s clouds and rain are expected to dampen activity. && .HYDROLOGY... Satellite imagery and ground reports indicate little ice remaining on the Aroostook River, but the Saint John River still has some ice-covered areas and ice is currently moving as evidenced by hydrographs. The ice is rotted such that it`s not highly conducive to prolonged jamming and the threat is not considered to be high. On the other hand, the combination of snow melt and rainfall is generating a more tangible threat by Thursday afternoon into Friday. With forecast QPF in northern zones in the range around 1.00 inch, rivers such as the Aroostook, Saint John, northern portions of the Penobscot and Mattawamkeag will trend towards minor flooding levels. If QPF forecasts increase for today into This evening, strong consideration will be needed for a Flood Watch in the northern zones...covering the aforementioned rivers as moderate flooding becomes a risk. There`s still sufficient snow cover in northern Aroostook to create issues...and it`s fully ripened after today`s warmth. Melting will continue non-stop into Sunday night. Overall, the biggest potential risk will be for the Saint John River. Small stream flooding is possible across interior Down east and coastal areas where highest rainfall amounts are expected. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...None. MARINE...Small Craft Advisory from 8 PM this evening to 10 AM EDT Thursday for ANZ050-051. && $$ Near Term...Hewitt/Mignone Short Term...Farrar Long Term...Farrar Aviation...Hewitt/Mignone/Farrar Marine...Hewitt/Mignone/Farrar Fire Weather...Hewitt Hydrology...Hewitt is the U.S. government's official web portal to all federal, state and local government web resources and services.