NWS Forecast Discussion
For Fremont, NH
000
FXUS61 KGYX 060747
AFDGYX
Area Forecast Discussion
National Weather Service Gray ME
347 AM EDT Sat Jun 6 2020
.SYNOPSIS...
A warm and humid south to southwesterly breeze this morning is
replaced by northwest flow tonight as a cold front crosses.
Showers and storms are expected to fire with the crossing front
with gusty winds and small hail possible. Drier and cooler air
filters in behind the front, then high pressure builds east into
the region through the first half of the next work week with a
warming trend. Precipitation chances return during the back end
of the week.
&&
.NEAR TERM /TODAY/...
Today, showers and storms are expected with a crossing frontal
system and forcing shortwave trough. The compact shortwave digs
down from Ontario through the Great Lakes region and into New
England today, meanwhile the surface low skirts across the
southern Canadian border, strengthening as it crosses into Maine
by mid-day. The first order of business is a prefrontal wave
and associated shower/elevated convection activity which will
track into northern NH around dawn, into western Maine by about
12Z with a weakening trend. The main show will be the crossing
cold front. High dew points well into the 60s plus increasing
shear and steepening lapse rates with the shortwave trough will
create a favorable environment for thunderstorms today as the
cold front crosses.
As temperatures climb with the diurnal trend today, into the 70s and
80s over the coastal plain (limited along the Mid-Coast with a cool
marine layer near the surface), instability grows to around 1500-
2000 MUCAPE/1000-1500 MLCAPE...caveats here are that convection from
this morning may work over the atmosphere to a certain degree over
the north and the marine layer over the MidCoast will take more
forcing to overcome. Nonetheless, hires models suggest the cold
front provides enough forcing to produce a line or two of
organized storms this afternoon. The greatest chances for
damaging wind gusts and hail exists over the lowlands and
foothills, where the crossing cold front has more CAPE to work
with during the day today. This aligns well with a marginal risk
outlined by the Storm Prediction Center. Behind the cold front,
a northwest breeze occasionally gust to around 20-25 kts takes
over with steep low-level lapse rates keeping shower chances
going until sundown.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY/...
Long after the cold front exits to the east over the waters, the
main trough axis aloft swings through tonight with an uptick in
light rain showers, mainly over the mountains. Temperatures will
steadily cool into the 50s and 40s, a few degrees below normal
for this time of year. Northwest flow continues into Sunday as
the trough pulls away with clouds lingering in the mountains
keeping temperatures cooler. Highs will be in the 60s north to
70s south, with the NW flow keeping the seabreeze at bay. Light,
scattered to isolated showers taper down through the day with
dry air pouring in from the north.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
We begin this forecast cycle with an upper level pattern of a
trough over the northeast and northwest CONUS with a strong
ridge built between over the Great Lakes. Undercutting that
ridge is tropical storm Cristobal.
Sunday will bring NWly flow, with some clouds lingering in the
mountains keeping temperatures cooler. Highs will be in the 60s
north to 70s south, with the NW flow keeping the seabreeze at
bay.
High pressure builds in for the start of next week. As it does we`ll
see increasing temperatures through the week. Initially offshore
flow will keep the seabreeze confined to the coast, thus have
increased temps on Monday slightly.
While the high builds into our region, well to our west
tropical storm Cristobal is moving up the west edge of the
ridge, bringing moisture to join with the northern stream short
wave over Ontario. Some of this moisture looks to make it over
the top of the ridge in at least the form of increasing clouds
for our area on Tuesday. Still a large spread from ensembles
with only around 40% producing any precipitation Tuesday night,
still will put a slight chance in the mountains for Tuesday
night where it`s most likely to see any precip.
Wednesday when the high shifts to the east, we`ll see a
stronger seabreeze develop, thus have lowered coastal
temperatures a bit for this period.
For the end of the week the extra tropical low which absorbed
the remnants of Cristobal will move across southern Canada,
dragging a cold front and showers across our region. The trend
has been slower with this system, which is consistent with the
fact that the initial flow is highly blocked. While the end of
the week will likely see some showers, the timing is still very
uncertain and have stuck close to the consensus for this update.
&&
.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
Short Term...Light SSWerly winds this morning bring humid conditions
with patchy fog and low ceilings leading to localized MVFR to
IFR restrictions to some portions of the area. Along the coast,
low ceilings and more dense fog is likely to impact RKD (LIFR),
and to a lesser extent PSM/PWM. Restrictions lift after sunrise.
A cold front and associated SHRA and TSRA activity crosses today
with localized IFR possible. Storms approach the Connecticut
River by around dawn, then re-fire along the front with
temporary restrictions during the afternoon, most likely for
Maine terminals. VFR returns behind the front with northwesterly
flow, except for over HIE where MVFR ceilings may linger into
Sunday.
Long Term... After the cold front moves through we`ll see NWly
flow through the day on Sunday. High pressure moves in for the
first half of next week with VFR continuing. While there may be
some clouds on Tuesday, still expect VFR through the middle of
the week.
&&
.MARINE...
Short Term...Southerly winds this morning ahead of a cold front
push seas to near 5 ft with SCA conditions most likely over the
Mid-Coast of Maine. Winds stay below 25 kts into the afternoon,
except locally in storms this afternoon as the cold front
crosses. Offshore winds take over after the front this evening
and overnight with winds gusts approaching 25 kts.
Long Term...NWly flow behind the cold front my approach SCA in
the eastern zones before beginning to subside on Sunday. High
pressure builds across the waters through the first half of next
week.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...Beach Hazards Statement from 8 AM EDT this morning through
this evening for MEZ023-024.
NH...Beach Hazards Statement from 8 AM EDT this morning through
this evening for NHZ014.
MARINE...Small Craft Advisory until 6 PM EDT this evening for ANZ150.
&&
$$
NEAR TERM...Casey
SHORT TERM...Casey
LONG TERM...Curtis