Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/29/21
AREA FORECAST DISCUSSION
National Weather Service Albany NY
1036 PM EDT Sun Mar 28 2021
.SYNOPSIS...
A strong cold front will move through overnight with
colder temperatures and windy conditions. The lingering rain showers
will mix with and change to snow with some light accumulations
across the higher terrain especially the western Adirondacks. Monday
will feature chillier temperatures along with very strong and gusty
winds especially in the morning. Temperatures will rebound to above
normal Tuesday and Wednesday. It will be sunny Tuesday with rain
overspreading the area Wednesday.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
Update...
High Wind Warning for gusts up to 60 mph for the Mohawk Valley,
Greater Capital Region, Schoharie Valley, Helderbergs, northern
Catskills, northern/central Taconics and the Berkshires.
Strongest winds are expected between 4 am and noon Monday.
Wind Advisory remains in effect for gusts up to 50 mph for
northwestern Connecticut, southeast Catskills, mid-Hudson
Valley, southern Taconics, Lake George Northern Saratoga County,
southern Adirondack Foothills, Hamilton County, Upper Hudson
Valley and southern Vermont.
As of 1030 PM EDT...A secondary cold front continues to move
across eastern NY and into western New England tonight. This
boundary has a much stronger surge of cold advection and better
cooling aloft with the sfc wave deepening over southeast Quebec
and merging with another short-wave over northern New England.
A deepening and intensifying sfc cyclone will increase the
momentum transfer overnight with a tightening sfc pressure
gradient. A few rumbles of thunder have occurred upstream and
over the southwest Adirondacks with the secondary cold front.
The winds will shift to the west and increase in the cold air
advection especially after midnight. The latest 3-km and HRRR guidance
has winds of 45 to 60 knots at the top of the mixing layer
which is why we have the Wind Advisory and High Wind Warning in
place. Some gusts of 35-60 mph are possible between 4 am - 6 am.
Rain will mix with and change to snow as the colder air filters
in with light snow accumulations above 1500 feet. 1 to 2 inches
are expected across the western Adirondacks and possibly the
high peaks of the southern Greens with less than an inch
elsewhere.
Lows temps will drop into the mid 20s to upper 30s overnight.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
Winds will be at their strongest in the morning especially
early with the region squeezed between the departing system and
an advancing high. Winds will be strong and gusty all day but
will decrease during the afternoon hours as the high builds in.
The warning may need to be downgraded to an advisory after the
strongest winds occur early in the day.
It will be a chilly day Monday. Highs will only in the 30s and
40s with some 20s in the highest terrain of the western
Adirondacks.
The surface high will shift eastward across the region Monday
night and off the coast by Tuesday morning with ridging building
in aloft. This will set us up for rebounding temperatures
Tuesday after a cold start with temperatures in the 20s. Readings
Tuesday afternoon are expected to climb into the lower 50s to
lower 60s. Much milder Tuesday night with deep southwest flow
developing across the region between the departing ridge and an
approaching and deepening trough. Clouds will be on the
increase especially late at night with lows in the mid 30s to
lower 40s.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
Upper level ridging will depart off the eastern seaboard on
Wednesday, while a deep upper level trough over the Midwest and
Great Lakes starts to approach. Our region will be dominated by
strong south to southwest flow aloft through much of troposphere.
Although the day will start off dry and fairly mild with temps
reaching into the 50s/60s, a strong cold front will be approaching
from the west for later in the day. Some showers are possible
along/ahead of this boundary, although this front will take on
anafront characteristics, as the deep flow aloft runs parallel to
the surface boundary, so most of the precip will be behind the
boundary.
Although the front should cross on Wednesday evening, precip will
linger behind the boundary for Wednesday night, as a wave of low
pressure develops on the front as it lifts across southern and
eastern New England. As a result, steadier precip looks to continue
for Wednesday night into Thursday morning. Initially, precip will
be just rain, but colder air will be moving in both aloft and at the
surface, as surface winds switch to the northwest winds along with
the approaching upper level trough. High terrain areas will be
changing over to snow after midnight and even valley areas may see a
rain/snow mix by daybreak as temps fall into the 30s, based on the
latest 12z GFS BUFKIT model soundings.
Steady precip should be ending on Thursday morning, as the
progressive storm system continues to depart. However, a few inches
of snow should have accumulated by this time (mainly for high
terrain areas and areas north/west of the Capital Region). Valley
areas will likely only have a slushy coating at most, but will need
to watch this closely in case the changeover happens faster. It
will remain very chilly and breezy for Thursday with the upper level
trough overhead and a few additional flurries and sprinkles are
possible, with temps remaining in the mid 30s to mid 40s. Any
lingering precip should end by Thursday night, with temps falling
into the teens and 20s.
With the upper level trough remaining overhead, chilly weather will
continue into Friday, although it should stay dry. Highs will only
be upper 20s to mid 30s on Friday with a partly sunny sky.
Temperatures should start to moderate over the weekend, with highs
back in the 40s for Saturday and into the 50s for valley areas by
Sunday. There could be a few passing light showers over the weekend
(mainly for northern areas) thanks to a northern stream system, but
moisture is limited, so will only limit POPs to slight chc at this
time.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
A cold front will move across eastern NY and western New England
early this evening. Low pressure moving across southeast Quebec
will deepen and intensify as it moves towards the Gulf of St
Lawrence overnight into tomorrow afternoon. Strong gusty winds
will persist into the afternoon at the TAF sites.
Expect a period of MVFR and spotty IFR low vsbys and stratus
with the frontal passage between 00Z-02Z/MON with sct showers.
Post frontal clouds in the high MVFR to low VFR range will
linger until 06Z/MON with some showers in the vicinity. The
winds will increase in magnitude and will be very gusty with
the deepening and intensifying cyclone and cold advection.
Conditions will improve to VFR levels at KGFL/KALB/KPOU between
06Z-12Z/MON, as some high MVFR stratocumulus will persist at
KPSF. Expect widespread VFR conditions in the late morning into
the afternoon with the skies clearing.
LLWS will be an issue a few more hours for KGFL/KPSF/KPOU before
the frontal passage at 02Z, and then better mixing will occur in
the wake of the front.
The winds will increase from the southwest to west at 8-15 KT
with some gusts 20-30 KT prior to midnight, then as the cyclone
intensifies and the low-level sfc pressure gradient strengthens
between the cyclone and high pressure building in from the
south and west, as the sfc winds will crank up between 06Z-
12Z/MON from the west to northwest at 15-25 KT with gusts 32-45
KT. The strongest gusts will be at KALB/KPSF. A few could even
exceed 45 KT after daybreak.
The winds will subside in the late afternoon around 22Z/MON at
10-18 kts with a few gusts still 25-32 KT at KALB/KPSF.
Outlook...
Monday Night: No Operational Impact. NO SIG WX.
Tuesday: No Operational Impact. NO SIG WX.
Tuesday Night: No Operational Impact. NO SIG WX.
Wednesday: High Operational Impact. Breezy. Likely SHRA...RA.
Wednesday Night: High Operational Impact. Definite RA.
Thursday: Moderate Operational Impact. Breezy. Likely SHRA...SHSN...RA...SN.
Thursday Night: Low Operational Impact. Breezy. NO SIG WX.
Friday: No Operational Impact. NO SIG WX.
&&
.FIRE WEATHER...
Turning colder and windy tonight. Any lingering rain will mix
with and change to snow with some light accumulations across
the higher terrain especially the western Adirondacks. Monday
will feature chiller temperatures along with very strong and
gusty winds especially in the morning. Temperatures will rebound
to above normal Tuesday and it will be sunny with minimum
relative humidity values in the 30s during the afternoon.
&&
.HYDROLOGY...
Widespread rainfall is resulting in within bank river rises
across the area. Turning colder tonight with any lingering rain
mixing with and changing to snow with some light accumulations
across the higher terrain especially the western Adirondacks.
Another widespread rain event is expected Wednesday with rain
changing to snow Wednesday night as colder air filters.
For details on specific area rivers and lakes, including
observed and forecast river stages and lake elevations, please
visit the Advanced Hydrologic Prediction Service /AHPS/ graphs
on our website.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...Wind Advisory until 6 PM EDT Monday for CTZ001-013.
NY...Wind Advisory until 6 PM EDT Monday for NYZ033-041-042-063>066-
082>084.
High Wind Warning until 6 PM EDT Monday for NYZ038>040-047>054-
058>061.
MA...High Wind Warning until 6 PM EDT Monday for MAZ001-025.
VT...Wind Advisory until 6 PM EDT Monday for VTZ013>015.
&&
$$
SYNOPSIS...IAA/Wasula
NEAR TERM...IAA/Wasula
SHORT TERM...IAA
LONG TERM...Frugis
AVIATION...Wasula
FIRE WEATHER...IAA
HYDROLOGY...IAA
Area Forecast Discussion
National Weather Service Denver/Boulder CO
909 PM MDT Sun Mar 28 2021
.UPDATE...
Issued at 909 PM MDT Sun Mar 28 2021
Looking upstream we are seeing a very strong mountain top stable
layer on the 00Z GJT and SLC soundings. Flow aloft strengthens
considerably overnight and early Monday morning per the previous
discussion. Expect flow of nearly 50 knots, amplifying up toward
70 knots on the eastern slope by early Monday morning per latest
cross sections and model output. We`ve upgraded to High Wind
Warnings for the Front Range Mountains and Foothills. There may
be a brief opportunity for mountain wave amplification down onto
the adjacent plains early to mid morning Monday, before the
airmass destabilizes and we lose our mountain top stable layer by
mid day. Then, winds will just blow rather strong and gusty
everywhere. We`ve made slight adjustments for higher winds in/next
to the foothills to account for the mountain top stable layer and
expected mountain wave amplification.
We also nudged up forecast high temperatures tomorrow considering
the strength of downslope, mostly sunny skies (less clouds
expected than today), and a well mixed atmosphere. Most of the
plains should hit 70F or better.
We still see a sharp change early tomorrow evening with the
passage of a cold front and strong, northerly winds. Most
mesoscale/CAMs show winds staying under high wind criteria, but
with such strong isallobaric acceleration expected we think
there`s still reasonable potential to hit high wind criteria
across the plains - perhaps as early as 4-5 pm over the far
northern border. We`ll keep the High Wind Watch in place there.
&&
.SHORT TERM...(This evening through Monday)
Issued at 208 PM MDT Sun Mar 28 2021
An increasing westerly flow aloft will develop over the forecast
area ahead of the next storm system. In the Front Range Mountains
and Foothills, spatial cross-sections indicate a decent amplified
mountain wave developing after 09z tonight and continuing through
Monday morning. Sangster model output, generated warning criteria
wind gusts from 09z through 17z Monday morning, via HRRR, NAM and
RAP data. That appears to be the main window for the strongest
wind gusts. The NAM12 cross-sections indicates a 70 kt cross-
mountain component to 700 mb, with 60 kts generated by the RAP.
Strongest winds, with peak gusts to 75 mph, will likely occur
along the higher east facing mountains slopes and in the foothills
of Larimer and Boulder counties above 7500 feet. The strongest
gusts should be more localized in and near the base of the
foothills. Consequently, we have issued a High Wind Watch for
zones 34>36 for late tonight through Monday afternoon, although
the mountain should start to break down after 18z. Scattered snow
showers will start to spread northwest to southeast in the
mountains, mainly north of the I-70 corridor after 21z. Across the
northeast plains, dry and windy through the afternoon, with max
temperatures in the upper 60s to lower 70s. This will result in
elevated fire danger across eastern Elbert and Lincoln County,
reference the fire weather discussion for details. A strong cold
front will push into the northern tier counties by mid afternoon,
with strong post front bora winds developing at that time.
Locations near the WY, KS and NE could experience peak wind gusts
50 to 60 mph along with a sharp drop in temperatures at that time.
Will issue an additional High Wind Watch to account for the
strong winds associated with the passage of the cold front.
.LONG TERM...(Monday night through Sunday)
Issued at 208 PM MDT Sun Mar 28 2021
Cold front will be blasting south across eastern Colorado early
Monday. An impressive 9-12mb surface pressure rise over 3 hours
will occur behind the front. Expect 50-60 mph northerly winds with
the cold front passage over the northeast plains. Temperatures
are expected to quickly fall into the 40s behind the front and
continue to fall through the evening. Will issue a High Wind Watch
for the northeast plains because 60 mph wind gusts will be
possible. Snow showers will be possible behind the front late
Monday night and Tuesday. Best chance and the highest totals are
expected to be south of I-70 where northerly winds will produce
upslope conditions. Up to 3-4 inches will be possible over the
southern foothills and along the Palmer Divide.
Airmass quickly dries out Tuesday evening bringing any snow
showers that formed to an end. Clearing skies, weak winds, and a
chilly airmass will lead to a cold night across the area. Lows
over northeast Colorado are expected to fall into the teens to
lower 20s. In the mountain valleys single digit lows are expected.
A warming trend begins Wednesday. Northwest flow aloft and
residual cool air will make for a cool but pleasant day with highs
in the 50s across northeast Colorado. Flow aloft becomes westerly
Thursday and remains westerly through next weekend. Ridging in
the westerly flow will produce mild temperatures. Highs climb into
the 60s for Thursday with 70s possible for Friday and next
weekend. No systems are expected to pass through the region, so
dry conditions are expected through Sunday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 909 PM MDT Sun Mar 28 2021
Winds will be the main concern through Monday evening. KDEN and
KAPA should see fairly normal south/southwest winds overnight, but
KBJC may see gusty winds to 20-30 knots redevelop overnight with
amplification of the mountain wave.
The strongest winds are expected to develop 15Z-19Z from west to
east across the Denver area TAF sites. KBJC will likely see gusts
to around 45 knots, while KDEN and KAPA should see gusts around 35
knots after 18Z-20Z, and continue from almost due west (270
degrees) til around 00Z Tuesday. That may cause crosswind
limitations for north-south runway configurations at KDEN. A
strong cold front is then expected to bring a shift to north
winds with a couple hours of 40-45 knot gusts 01Z-03Z Tuesday.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
High Wind Watch from Monday afternoon through Monday evening for
COZ042-044-046-048>051.
High Wind Warning from 3 AM to 4 PM MDT Monday for COZ033>036.
Red Flag Warning from noon to 7 PM MDT Monday for COZ246-247.
&&
$$
UPDATE...Barjenbruch
SHORT TERM...Cooper
LONG TERM...Meier
AVIATION...Barjenbruch
Area Forecast Discussion
National Weather Service Gray ME
1127 PM EDT Sun Mar 28 2021
.SYNOPSIS...
Low pressure tracking up the St Lawrence will bring widespread
rain overnight. A cold front will cross the region switching
rain to snow and bringing gusty NWly winds through the day
tomorrow. High pressure will build in for Tuesday before another
frontal system brings rain to the region Wednesday night into
Thursday.
&&
.NEAR TERM /THROUGH MONDAY/...
Latest Update...
Have sent out the late evening update. Band of precipitation
continue to become more showery in nature as of 0329Z per
latest radar imagery, however there is one last area of steady
rain moving through southeast New Hampshire and into southwest
Maine. This will cross the forecast area during the next two to
three hours before drier air builds in from the west and
upslope conditions take over in the northern mountains. Some
patchy freezing rain continues across the highest peaks, but
over the next couple hours, rain or snow showers will begin to
dominate as cold air advection ensues from the west. The latest
HRRR has the remaining precipitation exiting the region by 06Z
before terrain effects dominate the region.
The threat of any thunderstorm activity over southernmost New
Hampshire continues to diminish late this evening.
Winds will continue to back to the west and south in most areas
overnight. This is in response to lower pressure forming over
central Massachusetts and exiting over the coastal waters this
evening.
Doppler radar estimates about an inch of rain or more has
fallen across the region with additional rainfall along and
near the coastal front and the islands where locally over two
inches has already fallen. This seems reasonable with the
reports from COCORaHS and other surface observations we have
received, however all in all, the radar has underestimated the
precipitation. Rivers are continuing to respond and are rising
at this time.
The mixed precipitation over the higher terrain of northern
areas should hang on for another hour or two before changing to
all snow showers after midnight. CC values have indicated the
rapid retreat of frozen precipitation in most areas earlier this
evening.
Minor changes made to temperatures and dew points in the short
term portion of the forecast. Significant modifications made to
the wind direction and gusts.
Prev Disc...
A frontal system crosses the region today and tonight bringing
moderate to heavy rainfall along with snow and mixed
precipitation over the mountains and some of the more sheltered
valleys of the western Maine mountains. At this hour, the core
of the warm-frontal forcing associated with the system is
passing through New England, coincident with a 60-70 kt, south-
southeasterly jet at h850, which precedes the shortwave trough
aloft driving the system. Further upstream, the occlusion and
cold front with the system are crossing New York and PA with a
fine line of convection that currently has no lightning.
While a temperature inversion is keeping the jet elevated for
the majority of the region with a few surface observations
observing calm winds over the interior... better lapse rates
exist on the Midcoast of Maine where a few gusts to 40 kts are
expected later this evening, coinciding with an extant wind
advisory. In addition, the jet cruising over the Whites
continues to produce downsloping wind gusts around 35-40 kts
this afternoon over portions of northern New Hampshire,
coinciding with another segment of the wind advisory.
For precipitation... the forecast is well on track as
increasing SSE flow enhances rainfall rates in the south- east
facing upslopes where smaller streams are now beginning to
respond (more on hydro threat below). Will continue to maintain
a close eye on radar trends as precipitation picks up over the
coastal front as well, although generally with no snow and
little terrain enhancement am not overly concerned with flooding
threat there aside for the usual drainage issues. For the
remainder of this evening and tonight, heavy rainfall will exit
the region toward the east with a showery break before the cold
front/occlusion arrives around 00Z or so. This lull will see
weak wind fields and high humidity... so fog and low ceilings
will fill in until it starts to mix out behind the front. Have
maintained slight chance of thunder with the front for the
southern areas and along the coast with some elevated
instability. Precipitation comes to an end behind the front,
except in the mountains as winds back to the northwest and
producing upsloping showers.
Cold advection and better mixing arrive after this front, so
winds will pick up overnight... starting around midnight for
southwest New Hampshire and expanding eastward through the
remainder of the forecast area by dawn. More on wind below in
the short term section.
&&
.SHORT TERM /MONDAY NIGHT/...
By Monday morning, the surface low pressure system will be
deepening over the Canadian maritimes... increasing the PGF over
New England, leading to a windy day as cooler and drier air
arrive from the northwest. While winds and gusts will pick up
overnight, hires probabilistic guidance suggests the core of
strongest winds will struggle to mix down to the surface until
surface warming steepens lapse rates starting at sunrise. Am
expecting widespread wind gusts in the 40-45 kt range over the
mountains and for most of New Hampshire into southwest Maine
where another wind advisory is posted for tomorrow. Also have
wind gusts in the 50-55 kt range in the immediate downslopes of
the mountains but without coverage to go with high wind
headlines. Am less confident on wind gusts being quite as high
toward Maine`s capitol region, though it will certainly be a
breezy day regardless.
For precipitation and clouds... a strong drying trend will mean
a fairly quick end to upsloping snow showers near the
international border by around mid-day with rapidly clearing
skies. Temperatures will warm into the 30s over the north and
40s most everywhere else aided by the downsloping... to the
low- 50s for interior southern New Hampshire.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
Overview: Our next frontal system will move through the area on
Wednesday bringing another dose of solid rain. For the end of
the week blocking will develop over the North Atlantic, allowing
low pressure to remain overhead through the weekend.
Tuesday: High pressure will be overhead and shifting east through
the day. Expect a weak seabreeze to develop for the coast.
Additionally the increasing onshore flow for afternoon will keep
temperatures down on the midcoast.
Wednesday the next frontal system will approach from the west. Over
the past 24hrs guidance has trended from a straight cold frontal
passage to further develop the low as it moves through our region.
That low development would help to enhance the upslope flow and
mountain areas precip along with hold cold air in place longer. With
this update have trended towards this idea holding the temps down
somewhat, although still largely above freezing.
Rain will enter the region overnight. With good agreement on the
timing have kept PoP very high. While the majority of QPF falls
outside the time period of this forecast package it`s worth
noting that several heavy rain signals continue. Forecast
soundings show a deep saturated layer, with moderate storm
motion vectors training parallel to the front. IVT shows a solid
river of moisture from the deep south moving through our region
with this system. Current ensemble spread averages around 1" of
rain into the region but expect some higher amounts in the
foothills.
By mid day Thursday the low moves into the maritimes and cold air
filters in behind, switching the mountains over to snow as the
precip cuts off. Showers linger int he mountains overnight Thursday
into Friday.
Friday the upper level low remains overhead. Have increased the
cloud cover somewhat to account for this. While overall shower
activity will decrease expect the clouds to be a bit more robust
that guidance is indicating.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
Short Term...
Update...Have extended the time frame for LLWS through late this
evening. Will continue to monitor for an AWW at MHT.
Prev Disc...Widespread IFR ceilings are being reported right
now, except for LEB/HIE at MVFR, with RA/+RA crossing the area.
While most interior sites are seeing fairly light winds (except
for HIE which is downsloping from MWN to 35 kts from the
southeast this evening), coastal terminals gust to 25-30 kts
with RKD possibly reaching 40 kts this evening. Low ceilings and
FG/BR at IFR or worse will remain over the area until a cold
front/occlusion crosses tonight. The front will bring lifting
restrictions and a wind shift to the west, increasing into
Monday. Meanwhile MVFR ceilings will linger at KHIE through mid-
day Monday. West- northwest wind gusts in excess of 35 kts are
possible for all terminals tomorrow, strongest across the south
and in the mountains. LLWS is likely this evening into tonight,
until the front clears and winds pick up at the surface.
Long Term...High pressure builds overhead on Tuesday holding VFR
conditions. A front approaches on WEdnesday brining widespread
rain to the area Wednesday night into Thursday. Expect IFR in
rain, with areas of fog. Additionally a low level jet may result
in Low level wind shear ahead of the front. Temperatures will
drop changing over to light snow in the mountains on Thursday as
the system exits into the Maritimes.
&&
.MARINE...
Short Term...Onshore gales today coinciding with seas building
to 10-15 over the outer waters ahead of a crossing frontal
system will be replaced by strong offshore gales tomorrow in the
wake of the frontal system. Gales will taper to SCAs tomorrow
night with the Bays going quiet as high pressure approaches from
the west.
Long Term...High pressure builds over the waters on Tuesday.
Southerly flow begins to increase on Wednesday with a cold front
bringing rain to the waters early Thursday morning.
&&
.HYDROLOGY...
Solid rain will exit the forecast area late this evening.
Storm totals should end up in the 1-2 inch range with locally
higher amounts along and near the coastal front. FFG values
generally over 2 inches. Headwater drainages are still holding a
few inches of SWE and runoff is expected to contribute to
multiple rivers rising to action stage.
The Connecticut at Dalton remains above action but is expected
to hold below minor flood. As the runoff from this rain reaches
the rivers expect the headwaters to rise overnight to near
flood stage. Swift River at Roxbury, Saco and Conway, and Pemi
at Woodstock will all need to be watched closely. Further west
into Maine expect slightly more of the QPF to come as snow which
will limit the runoff into the upper Kennebec basin.
&&
.TIDES/COASTAL FLOODING...
Seas and elevated storm surge values will continue tonight as
seas remain high and strong gales impacted the waters earlier
this evening. There continues to be significant disagreement
between the models which lowers confidence in the overnight
coastal flood forecast. Have leaned towards close to a foot of
storm surge at high tide with nearshore waves around 10 to 15
feet which is similar to the 0300Z observations. This is more in
line but a little higher than ESTOFS values. This may allow for
splash-over and pockets of minor coastal flooding from Hampton
northward through Portland. Splash-over is also possible along
the Midcoast. Therefore, have issued a Coastal Flood Advisory
for the midnight high tide for all areas.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...Flood Watch until 8 AM EDT Monday for MEZ007-012-013-033.
Wind Advisory from 4 AM to 6 PM EDT Monday for MEZ007>009-012-
018>020-023>025-033.
Coastal Flood Advisory until 1 AM EDT Monday for MEZ023>028.
NH...Flood Watch until 8 AM EDT Monday for NHZ002>006.
Wind Advisory from 4 AM to 6 PM EDT Monday for NHZ001-004>015.
Coastal Flood Advisory until 1 AM EDT Monday for NHZ014.
Wind Advisory until 5 PM EDT Monday for NHZ002-003.
MARINE...Gale Warning from 4 AM to 6 PM EDT Monday for ANZ153.
Gale Warning until 8 PM EDT Monday for ANZ150>152-154.
&&
$$
Cannon/Clair
...Update to aviation forecast discussion...
.DISCUSSION...
Issued at 342 PM CDT Sun Mar 28 2021
Focus for this forecast remains to be on conditions Monday morning
through early Tuesday. Very deep upper trough digging into
southwestern Canada on track to move east along the U.S. border
through Monday night with a sub-980 mb surface low attending.
Downstream pressure gradient quite strong late tonight through
Monday evening in the local area with 850 mb winds increasing to
near 50 knots tonight, 60 knots Monday, and 75 knots Monday night
before a sharp cold front passes. Some mixing of these winds may
lead to steady temps late tonight with a quick warm-up Monday as WAA
is realized via the deepening boundary layer. Guidance continues to
show a decent spread in surface winds but given extreme NAEFS output
for 850 mb speeds and RAP and HREF gusts, have pushed on the
stronger end of NBM for speeds. This brings Advisory levels (mainly
gusts) to the bulk of the area with some concern for some gusts
around 60 mph as mixing depths deepen through the day and then at
least somewhat into the evening and overnight in southern locations
where the stronger jet exists. Have attempted to cover the most
likely conditions with a Wind Advisory and High Wind Watch but some
alterations in time and space are certainly plausible. Will also
need to keep an eye on post-frontal wind surges with a very tight
gradient following a surface low as it treks southeast through
central and eastern Kansas, though gradient levels fall off through
the night.
This front helps keep dry conditions in place through the coming
weekend with a northerly wind component into south Texas through
Thursday morning. Gusty winds Tuesday drop off for a cool and more
tranquil Wednesday. Southerly flow picks up again Thursday into
Friday with warming temps.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 619 PM CDT Sun Mar 28 2021
Winds and LLWS continue to the main concerns for this forecast.
LLWS looks to develop in the 06Z-08Z period and continues through
15Z. Surface winds will be light to start the forecast then back
to the south by 06Z with winds around 10 kts, then increasing
after 14Z and continuing through the end of the period.
&&
.FIRE WEATHER...
Issued at 342 PM CDT Sun Mar 28 2021
A volatile situations remains to be expected Monday and Monday
night. Have continued the forecast for a warmer and windier day than
average guidance would suggest. Speeds increase through the morning
with gusts of 40 to near 60 mph midday through late afternoon, with
southeastern districts possibly seeing the strongest winds in the
late evening to around midnight Monday night/early Tuesday. RH
values on track to fall into the upper teens to mid 20s, though some
models continue to suggest a moistening boundary layer with little
evidence apparent as to why this would transpire. After coordination
with fire partners, fuels are still close enough to cause difficult
control and upgraded the Watch to a Red Flag Warning. A cold front
will bring a rather sharp wind shift Monday evening to pre-dawn
Tuesday from northwest to southeast across the area and in some
regards this shift is not too concerning given the nearly 180-degree
shift, though some eastward-build may occur as the front passes and
a west wind component forms. Satellite and radar observations today
showing many burns occurring and any lingering embers could easily
rekindle Monday. Northerly breezes Tuesday with RH values again into
the 20s keeps at least minor concern going. Thursday and Friday
again looking like other days of note if fuels remain on the dry
side.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning from noon to 9 PM CDT Monday for KSZ008>012-
020>024-026-034>040-054>056-058-059.
Wind Advisory from noon Monday to 1 AM CDT Tuesday for
KSZ010>012-021>024-026-034>036-038>040.
High Wind Watch from Monday afternoon through late Monday night
for KSZ037-054>056-058-059.
&&
$$
DISCUSSION...65
AVIATION...53
FIRE WEATHER...65