Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/16/21
Area Forecast Discussion
National Weather Service Gray ME
947 PM EDT Tue Jun 15 2021
Low pressure will allow for scattered showers and a few storms
this evening, before exiting to the northeast tonight. High
pressure builds into the region for the middle of the week with
seasonable temperatures and a dry westerly flow. Temperatures
start to increase by the end of the week. A cold front crosses
Saturday with showers and thunderstorms.
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
945 PM Update...Any remaining showers will dissipate or move
away from the region over the next 2 hours. Skies are clearing
downwind of the mountains so it`s likely that we`ll have some
locally dense fog to deal with until passing cold front stirs up
the boundary layer a bit in a few hours. Otherwise, thunder is
done for the evening.
627 PM Update...The threat for additional severe thunderstorms
is now diminishing as convection over the past few hours has
worked over the atmosphere. Instability will decrease through
the next hour with effective shear moving offshore. Chances for
showers and scattered thunderstorms will continue through 10 pm
as a surface trough crosses the area. Clearing skies later
tonight combined with plenty of low level moisture will lead to
areas of patchy fog. Have updated PoP and weather forecast
through tonight to account for latest mesoscale guidance and the
diminishing chances for strong thunderstorms.
Current water vapor imagery shows a compact upper low over
the Champlain Valley. Ahead of this feature there is a pressure
trough oriented south to north through the forecast area. Convective
showers have started to develop within this trough with more
scattered thunderstorms expected with this feature as it slowly
moves east this evening. Latest RAP analysis has about 500 J/kg
of MLCAPE over New Hampshire into NW Maine where cloud cover
has thinned. RAP analysis also shows a ribbon of of effective
bulk shear to 35 kts just to the east of the axis of MLCAPE. As
convection continues to develop the best shear will be shifting
over the Gulf of Maine with only about 20 to 25 kts of 0-6 km
bulk shear remaining over the forecast area.
The lack of shear will limit the potential for organized convection,
however ingredients have started to become better aligned.
MLCAPE is expected to remain around 500 J/kg over much of the
area away from the coast with theta-e advection axis
intersecting the MLCAPE and some shear along the ME/NH border
eastward along the coastal plain. The last few runs of the HRRR
have been highlighting an area of stronger cells from the White
Mountains south to Strafford County with these cells moving
eastward through western Maine from about 5 pm to 9 pm before
the loss of heating leads to weakening trend.
The surface trough will clear to the east tonight while troughing
aloft lingers into Wednesday. Winds will shift out of the northwest
behind the trough bringing dry air into the area overnight.
Dewpoints and temperatures will drop into the 40s north and 50s
south. With clearing skies and closing dewpoint depressions patchy
fog will likely develop tonight with best chances in the Connecticut
Valley and along the coastal plain.
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
Troughing aloft continues over the East Coast through Wednesday
with an upper low closing off to our north. With the upper
trough axis nearly overhead forcing for ascent will be well to
our east with high pressure building to our west. Northwest
winds will continue to usher in drier air through the day with
mostly sunny skies expected outside of upslope clouds over the
mountains. Highs will be in the 60s in the north with low 70s
along the interior. Downsloping winds will allow for highs to
approach the mid 70s near the coast and southeastern New
High pressure will nose in from the west Wednesday night with
mostly clear skies. Dewpoints will be in the low 40s and with
mostly clear skies overnight lows will drop into the mid 40s
north to the low 50s along the coast.
.LONG TERM /THURSDAY THROUGH TUESDAY/...
The upper level trough that has been slowly moving across New
England will finally begin to exit the region on Thursday.
However, there may be enough upslope flow over the elevated heat
source to produce a brief shower or a sprinkle over the northern
higher terrain during the afternoon hours.
It will be seasonably mild with high temperatures in the 70s in
most areas outside the high terrain.
A southwesterly flow will develop on Friday bringing in an
increase in temperatures and gradually beginning to increase humidity
values. H8 readings around +10C, along with mixing under sunny
skies will yield high temperatures in the lower 80s across the
interior and our southern coastline. Along the Midcoast region,
temperatures will be held into the lower to mid 70s as winds
come in off the Gulf of Maine.
The southwesterly gradient will allow a warm front o cross the
region Saturday. As the atmosphere destabilizes with time,
showers and scattered thunderstorms will break out across the
region. With impressive dynamics and increased precipitable
water values, this may be our only chance for widespread
rainfall through this week. However, model ensembles continue to
not be overly generous with the precipitation totals, especially
in southern areas along or near the coastline.
A few hit or miss scattered showers are possible on Sunday as an
upper level trough exits the region. The best chance for a
shower would be the northern mountains.
After a dry start to the work week on Monday, a few more
scattered showers will enter the region Tuesday as a fast moving
upper level trough approaches the region from the west.
.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
Short Term...Cigs will lower overnight across Maine with patchy
fog bringing IFR/LIFR conditions through the first part of
tonight. Mainly VFR is expected tonight over New Hampshire
except at KPSM where low cigs will bring a few hours of IFR/LIFR
conditions. There is the chance for some patchy fog at KHIE and
KLEB but confidence is not high enough to put it in the TAF.
Winds shift out of the northwest late tonight bringing in drier
air and VFR to all terminals by tomorrow morning with VFR
prevailing through Wednesday night.
Long Term...High pressure and VFR conditions through the end
of the week with afternoon seabreezes. Friday increasing
southerly flow ahead of a front could bring some advection fog
to the midcoast. The front crosses the region on Saturday with
scattered showers and thunderstorms. This will lower many areas
briefly to IFR and LIFR.
Short Term...Winds turn offshore tomorrow morning for improving
visibility. Winds and seas generally stay below SCA thresholds
with the exception being the potential for seas to approach 5 ft
for brief period Wednesday evening along the outer waters.
Long Term...Winds and seas will be below SCA thresholds through
much of the period. However, there will be gusts to 25 knots as
an increased southwesterly gradient set up over the region
Friday into Saturday ahead of an approaching frontal system.
Area Forecast Discussion
National Weather Service San Angelo TX
612 PM CDT Tue Jun 15 2021
(This evening through Wednesday)
Issued at 1230 PM CDT Tue Jun 15 2021
Visible satellite imagery this afternoon showed a nice scattered
cumulus field having developed across the region. Meanwhile, on
water vapor satellite, there is an obvious short-wave trough
moving south across the DFW region, which could be a source for
lift. Forecast soundings from the RAP model indicate that the
capping inversion may be overcome in some locations (due to a
combination of the lift from the short-wave and increased
instability from afternoon heating) for there to be small isolated
showers/storms that develop late this afternoon, generally along
and south of a San Angelo to Brownwood line. Since any
showers/storms would be diurnally drive, any precipitation should
end shortly after sunset. Meanwhile, expect afternoon highs today
in the mid 90s.
Tonight, despite dewpoints in the 60s, the light winds and clear
skies should induce enough radiational cooling for the lows to
drop into the upper 60s for most of the region.
Wednesday, some warming of the 850 mb thermal ridge, a switch of
surface winds to a warmer southeasterly direction, and mostly
sunny skies, should result in warmer temperatures, with highs in
the mid to upper 90s. Looks like the capping inversion is a little
stronger tomorrow, so no showers/storms are expected.
(Wednesday night through next Tuesday)
Issued at 221 PM CDT Tue Jun 15 2021
We will continue with the mostly hot and dry forecast through the
long term period. Highs will likely remain in the middle 90s to
103. The persistent high pressure ridge may budge some towards
day 7, but that is uncertain at this time.
Issued at 610 PM CDT Tue Jun 15 2021
A few showers and isolated thunderstorms around early this
evening should dissipate after sunset. Otherwise, VFR conditions
expected with light and variable winds overnight, becoming
easterly at 8-10KT Wednesday afternoon.
.PRELIMINARY POINT TEMPS/POPS...
Abilene 69 95 71 95 / 0 0 0 0
San Angelo 69 98 70 98 / 0 0 0 0
Junction 69 95 69 97 / 0 5 0 5
Brownwood 69 97 70 96 / 0 0 0 0
Sweetwater 68 97 71 96 / 0 0 0 0
Ozona 69 94 70 94 / 5 0 0 0