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Area Forecast Discussion (AFD)

Issued by Caribou, ME (CAR)

FXUS61 KCAR 180218

Area Forecast Discussion
National Weather Service Caribou ME
1018 PM EDT Wed Apr 17 2019

High pressure will crest over the area tonight then move east on
Thursday as a warm front lifts to our north. A large high 
pressure system to our east combined with a strong storm over 
the Appalachians will bring a humid southerly flow with showers
Friday through the weekend.


1005 PM Update: No sig chgs this update outside of updating 
fcst hrly temps/dwpts into the late ngt hrs based on trends 
from latest mid eve sfc obs. Good radiational cooling conditions
cont with max potential sfc base invsn potential ovr coldest
broad Nrn rvr vly lctns upwards to 8-10 deg C, which could 
result in ovrngt lows a few deg F colder ovr these areas then
currently indicated. For now though, no lctn was in immediate 
danger of exceeding fcst ovrngt lows 

Orgnl Disc: High pressure cresting over the area tonight will 
bring a clear, calm, cool and moonlit night. The high will move 
east on Thursday as clouds quickly increase ahead of a warm 
front lifting north into the area. A southerly breeze will also 
rapidly increase during the day and showers will become likely, 
mainly over the north, during the afternoon as low pressure 
lifts from the Great Lakes area into Quebec. The showers may mix
with just a bit of sleet or snow over far northeastern areas at
the start. Otherwise, warmer and more humid air should begin to
work north across the region as the south winds increase.


Low pressure is expected to pass to the west of New England 
Thursday Night. This system will cause rain Thursday Night into 
Friday across the region. A cold front will become stationary 
just to the west of the State Friday Morning. Another low moving
along the stationary front will result in more rain Friday 
Afternoon into the day Saturday as the front remains stationary 
to the west of New England. Due to high dew points in the 
southerly flow, fog is expected Thursday Night into Friday 
Morning and again Friday Night into Saturday Morning.


Low pressure will move to the north of the region Sunday with
showers expected to continue upper level low pressure moving
across the region. Strong high pressure is expected to build in
from the northwest Monday and Tuesday then crest over the region
on Wednesday. Another area of low pressure is expected to
approach from the west on Thursday.


NEAR TERM: VFR conditions are expected across the area tonight
into Thursday morning. Conditions may lower to MVFR and possibly
IFR Thursday afternoon in rapidly increasing and lowering clouds
with a warm front. 

SHORT TERM: MVFR/IFR conditions are expected Thursday Night 
into Sunday. VFR/MVFR conditions are expected on Monday.


NEAR TERM: Winds will be very light tonight, then rapidly
increase from the south on Thursday reaching SCA Thursday
afternoon. Seas will begin to build Thursday afternoon in
response to the increasing winds reaching 3 to 4 ft by late

SHORT TERM: Have used the Nam to initialize winds. For Waves: A
southerly fetch is expected to develop across the Gulf of Maine
Thursday Night into Friday with wind wave building to around 10
feet/8-9 seconds by early Friday Morning. Southerly wind speed
is not sufficient for additional wave building Friday then 
waves will very slowly subside on Saturday. A new southeasterly 
fetch is expected to develop during the day on Sunday.


An ice jam has been occurring in the St. John river between 
Fort Kent and Van Buren and still has the potential to cause 
some flooding along the river tonight into Thursday. Ice jams 
will also be possible on the Allagash, Big Black and Fish 
through Thursday. The Aroostook is holding at moderate flood 
stage at Washburn and action stage at Masardis. The Mattawamkeag 
is above minor flood stage and continuing to rise. Some flooding
remains possible along these rivers through Thursday. However, 
most of the ice has pushed through so these will be open water 
flooding with very abrupt changes less likely than further 

A large, slow moving storm system lifting up through the
Appalachians Thursday night through the weekend will bring a
warm and humid southerly wind with periods of rain which will
run from Thursday night into Sunday. Total rainfall amounts of 2
to 3 inches are possible across the north. The rainfall combined
with snowmelt will result in a serious flood risk later this 
weekend into early next week. There is potential that flooding 
in the St. John valley may be as serious as the flooding of late
April of 2008. All interests along the rivers are urged to stay
updated on forecasts, alerts and warnings through the weekend 
into early next week.


ME...Flood Watch until 4 AM EDT Thursday for MEZ001-002.



Near Term...VJN
Short Term...Mignone
Long Term...Mignone