Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 04/22/22
AREA FORECAST DISCUSSION
National Weather Service Albany NY
1001 PM EDT Thu Apr 21 2022
.SYNOPSIS...
Dry and tranquil weather returns to the area on Friday.
Temperatures will be returning closer to seasonable levels today
through Saturday before increasing to warmer than normal levels
Sunday and Monday. Temperatures are expected to cool down again
mid to late next week.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
UPDATE...As of 10 PM EDT, little in the way of showers across
the region, with a few breaks in the clouds developing,
especially across the western Mohawk Valley.
Meanwhile, watching an area of showers and isolated thunderstorms
along the northern shore of Lake Ontario, tracking generally
east. These showers are coincident with the left exit region of
a cyclonically curved upper level jet max, and at the leading
edge of mid/upper level cold pool and near the incoming
cold/occluded front. Latest RAP13 and HRRR suggests an area of
sfc-H700 LI`s of 0 to -2C in this area, which is expected to
overspread portions of the southwest Adirondacks (mainly
northern Herkimer/Hamilton Counties) shortly after midnight as
this feature approaches. So, expect an uptick in shower
coverage between roughly midnight and 3 AM in this area, and
have also included mention of isolated thunder as well.
Farther south, generally partly to mostly cloudy skies should
give way to some clearing after midnight. There could be some
showers grazing areas as far south as the Mohawk Valley, Lake
George/Saratoga region and southern VT between roughly 2 and 4
AM.
Still expecting lows in the mid/upper 30s across the southern
Adirondacks, and 40s elsewhere.
Previous discussion follows...
UPDATE...As of 7 PM EDT, other than a few sprinkles, most of
the showers have ended for areas along and south of I-90.
Lingering showers and sprinkles continue to the north,
especially across the southern Adirondacks. This will likely
persist for another 1-2 hours, before a brief decrease in
coverage. However, as main cold/occluded front approaches from
the northwest, and with the southern Adirondacks proximate to
left exit region of cyclonically curved upper level jet max,
expect another possible uptick in shower coverage between
midnight and 4 AM, which could extend as far south and east as
the Mohawk Valley, Saratoga/Lake George region, and southern VT.
Otherwise, will have to watch for patchy fog development in
areas which received rainfall today (mainly southwest
Adirondacks and Lake George/Saratoga region), as some breaks in
the clouds may develop later tonight, allowing for localized
cooling and patches of fog to develop, before west to northwest
winds increase again closer to daybreak and mix out any such
conditions.
Previous discussion follows...
Showers tracking through our region that will exit through the
evening. Cold advection will spread across the region as
shift to steady northwest later tonight. The cloud cover will
begin to exit and break up toward daybreak and the clouds and
wind will prevent temperatures from falling as much as they
could. Lows in the 40s with 30s in higher terrain.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
Low level ridging from Canada will build into our region as cold
advection continues. Lots of sun with gusty northwest to north
winds are expected with highs in the upper 50s to lower 60s and
around 50 to mid 50s higher terrain.
Clear with light to calm winds Friday night. Weak warm advection
and associated cloud cover tracks into our region Saturday as
low level ridging just begins to build east. The light winds and
intervals of clouds will limit warming. Highs Saturday in the
upper 50s to lower 60s with mid 50s in higher terrain.
Weak upper energy and warm advection could support a few showers
north and west of the Capital Region Saturday evening before
stronger warm advection occurs through Sunday. Limited deep
moisture will prevent chances for showers later Saturday night
through Sunday but some intervals of mid and high clouds are
possible. Low level ridging to the east is expected to support
some onshore low level flow that cold keep some western New
England areas cool. Highs Sunday in the 60s with some lower 70s
in the mid Hudson Valley and around 60 to mid 60s higher
terrain, southern VT, Berkshires and NW CT.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
Eastern NY and western New England will be under the influence of an
omega block pattern late this weekend into early next week as the
associated ridge axis moves overhead. While this should lead to
spring-like temperatures through Monday, a cut-off low off the
Canadian Maritimes with high pressure and southeasterly winds
building in its wake over New England could reduce the warming
potential, especially east of the Hudson River. Therefore,
temperatures east of the Hudson may only climb into the low to mid
60s on Monday while areas in the Mohawk and Schoharie Valley could
reach well into the upper 60s to low 70s.
Otherwise, expecting increasing clouds Monday as a cold front
gradually advances eastward. Guidance has delayed the onset of POPs
due to the ~1025hPa high pressure over New England but we still show
slight chance and chance POPs spreading eastward through most of the
CWA by 18 UTC Mon - 00 UTC Tues with chance and likely POPs in place
for Monday night. We still held off on including any thunder as the
better instability is displaced well to our south and west.
The cold front is slow to push through the area and actually still
looks to be overhead by Tuesday morning. In fact, guidance continues
to be in good agreement suggesting the upstream parent trough over
the Great Lakes becomes neutral to even negatively tilted during the
day Tuesday. This could result in a secondary low developing along
the boundary and tracking northward up the East Coast which would
maintain showers over much of the area for Tuesday, especially east
of the Hudson River. Since guidance has shown this signal for the
past few model runs, we maintained likely and chance POPS through
the day Tuesday with the highest POPs in western New England.
Temperatures would still be seasonable as the temperature gradient
would be overhead so still show highs reaching into the upper 50s to
low 60s.
Unfortunately, the wet and below normal temperature pattern
continues for the rest of the week as guidance is in good agreement
suggesting the aforementioned omega block pushes into the Atlantic
and the parent trough on its west side cuts off and lingers over the
Northeast. Moist, cyclonic flow persists Wednesday through at least
Thursday which will support scattered showers and chilly
temperatures as northwest flow ushers in a much cooler air mass. In
fact, showers that linger past sunset in the high terrain could very
well mix with and even change to snow Thursday night. While the
frost/freeze season technically does not begin until May 1 for the
Hudson Valley, sensitive vegetation may need to be monitored if
confidence increases for clear skies and near freezing overnight
temperatures. The latest NAEFS suggest temperatures Wednesday
through Thursday could be 2 - 2.5 degrees below normal and the
breezy northwest winds in place will likely make it feel even colder
by late April standards.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
Dry air in the low-levels has prevented much in the way of
showers late this afternoon and early evening with VFR
ceilings persisting. A few leftover showers are exiting to the
east of the terminals and a break in the showers will take
place until about 03 UTC. Then, a second area of light showers
may return mainly for ALB, PSF and GFL from 03 - 08 UTC;
however, dry air will once again limit ceilings and visibility
from dropping and VFR conditions should persist. PSF may be the
one exception with potential for low end VFR ceilings and we
included that potential in the latest update. While we did not
include MVFR ceilings at this time due to low confidence, we
will need to monitor trends.
After 09 UTC, skies should clear and, depending if enough
precipitation falls, some patchy fog may develop at GFL. Again,
did not include in this TAF update but we will need to watch
trends closely. Any fog should dissipate by 12 UTC when strong
winds will return. VFR conditions will persist through the end
of the TAF period.
Breezy southerly winds sustained 10 to 18kts with gusts to 25kts
will continue through about 03 UTC, after which winds should
finally weaken and shift to the southwest. However, southwest winds
will remain elevated sustained near 5 - 9kts overnight at all
TAF sites. Then, by 12 - 15 UTC, winds shift to the west and
increase considerably to become sustained 10 to 15kts with gusts
to 25-30kts once again. Winds shift to the northwest by midday
and remain breezy with gusts to 25kts expected.
Outlook...
Friday Night: No Operational Impact. NO SIG WX.
Saturday: No Operational Impact. NO SIG WX.
Saturday Night: Low Operational Impact. Slight Chance of SHRA.
Sunday: No Operational Impact. NO SIG WX.
Sunday Night: No Operational Impact. NO SIG WX.
Monday: Moderate Operational Impact. Chance of SHRA.
Monday Night: High Operational Impact. Likely SHRA.
Tuesday: Moderate Operational Impact. Likely SHRA.
&&
.FIRE WEATHER...
Gusty north to northwest winds to 25 mph Friday...
Dry and tranquil weather returns to the area on Friday.
Temperatures will be returning closer to seasonable levels today
through Saturday before increasing to warmer than normal levels
Sunday and Monday. Temperatures are expected to cool down again
mid to late next week.
RH values 70 to 100percent tonight. RH values drop to the 30 to
45 percent range Friday afternoon. RH values up to 70 to 100
percent Friday night. RH values dry to 25 to 40 percent
Saturday.
Gusty south winds at 15 to 25 mph into this evening will shift
to north and northwest later tonight at around 15 mph. North to
northwest winds are expected Friday afternoon at 15 to 20 mph
with gusts around 25 mph. North to northwest winds diminish to
less than 15 mph Friday night and continue Saturday.
&&
.HYDROLOGY...
A weak frontal boundary will bring the chance for showers this
evening, mainly across the northern half of the forecast area.
Rainfall amounts will be light. Dry and tranquil weather
conditions return to the area on Friday. River levels will by
and large will remain below action stage, and will continue to
be steady or lower in elevation over the next few days. Overall,
no major or widespread hydrologic issues are expected for the
foreseeable future.
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...None.
NY...None.
MA...None.
VT...None.
&&
$$
SYNOPSIS...NAS
NEAR TERM...KL/NAS
SHORT TERM...NAS
LONG TERM...Speciale
AVIATION...Speciale
FIRE WEATHER...NAS
HYDROLOGY...NAS
Area Forecast Discussion
National Weather Service Columbia SC
808 PM EDT Thu Apr 21 2022
.SYNOPSIS...
High pressure will dominate the forecast period through
early next week with steadily warming temperatures and dry
weather expected each day. Highs will be in the 80s late this
weekend and early next week. The next chance of rain will be
Tuesday as a cold front brings scattered showers and
thunderstorms to the Southeast.
&&
.NEAR TERM /UNTIL 7 AM FRIDAY MORNING/...
Continued weak southeasterly winds just above the boundary
layer will support further moisture advection in the low levels
and with strong radiational cooling conditions expected under
mostly clear skies and light winds, fog and stratus potential
should be better than last night. HRRR is showing some patchy
fog/stratus development during the 09z- 12z time frame across
the Coastal Plain and southeast Midlands into the CSRA. Low
temperatures are expected to drop into the lower 50s.
&&
.SHORT TERM /7 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
Fair weather expected through Saturday. Upper level ridging and
a relatively dry airmass will remain over the Southeast through
the period. Light easterly winds will provide some shallow
moisture increases through onshore flow. This will lead to fair
weather cumulus each afternoon and a few mid or low-level clouds
overnight. Strong subsidence will prevent any deep convection
and rainfall. Temperatures will be warmer than earlier in the
week. Highs will be in the low to mid 80s each day. Overnight
lows will likely be in the low and mid 50s as dewpoints slowly
rise across the region. Patchy fog may develop overnight but
will mainly be restricted to river valleys and other fog prone
areas.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
Upper level ridging will remain in place for Sunday and into
early next week. This will continue the pattern of fair weather
and above normal temperatures through Monday. Highs on Sunday
and Monday will be in the 80s with lows around 60 degrees.
Monday appears to be the warmest day with some areas breaking
into the upper 80s. This will be well above normal but still
several degrees shy of record values.
Global models generally agree on an upper level trough lifting
across the eastern US on Tuesday pushing a cold front through
the Southeast. Warm, moist advection ahead of the front will
push temperatures into the 80s on Tuesday and support a chance
of showers and thunderstorms. High pressure will push in behind
the front for midweek bringing back near-normal temperatures and
dry weather through the end of the long term.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
Brief VSBY restrictions expected early this morning at all
terminals but otherwise VFR.
Some passing high clouds over the terminals this evening with
winds becoming light and variable over the next couple hours.
Moisture in the low levels has continued to increase and with
winds light overnight, patchy fog will be possible. The best
chance for fog will be at fog prone AGS/OGB with higher
crossover temps. For the most part, expect MVFR VSBY
restrictions at least for a brief period at all terminals with a
period of IFR VSBYs possible at AGS. Any fog will dissipate
after sunrise with cumulus deck developing during the day around
5kft with winds out of the ESE around 5 kts.
EXTENDED AVIATION OUTLOOK...Apart from brief morning visibility
restrictions in fog prone areas, no significant impacts to
aviation are expected until late Monday when a front will
approach the region.
&&
.HYDROLOGY...
River flood warnings continue along the Congaree River as a
result of recent heavy rainfall and upstream dam operations.
More information can be found at https:/water.weather.gov/ahps.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
&&
$$
Area Forecast Discussion
National Weather Service Goodland KS
549 PM MDT Thu Apr 21 2022
.SHORT TERM...(This evening through Friday)
Issued at 200 PM MDT Thu Apr 21 2022
Warm front is currently lifting out of southwest Kansas and
approaching the Interstate 70 corridor. It is accompanied by low
clouds, much higher dew points and moderate surface based
instability up to 3000 j/kg according to the latest RAP analysis
and forecasts. So far have not seen any convection with the front
to the south. Latest HRRR suggests convection will not occur until
after 00z this evening, and well east of the area in north central
Kansas. While cannot completely rule out an isolated thunderstorm
in far eastern areas late this afternoon and evening, confidence
is low. On the other hand, with the higher dew points do think
that areas of fog will develop after sunset tonight and persist
into the overnight hours. Followed the HRRR/RAP/LAMP visibility
forecasts which all show fog developing south to north shortly
after 00z and continuing through early Friday morning as it
continues to lift northward. Low temperatures will be in the 40s
and 50s.
Friday continues to look like an active day due to the combination
of high winds, blowing dust, critical fire weather and severe
thunderstorms. Went ahead and upgraded the entire area to a high
wind warning. Winds should rapidly increase as mixing commences
Friday morning and taps into a 50-70kt southwesterly mid level
flow ahead of an approaching shortwave trough. Strongest winds
will occur in northeast Colorado/adjacent counties where gusts
over 70 mph will be possible, decreasing to around 60 mph gusts
further east. Winds of this magnitude will likely create
widespread blowing dust and localized dust storms with near zero
visibility. After about 21z, the dry line is forecast to sharpen
up near the Colorado and Kansas border area. At this time, the 3km
NAM continues to be the most aggressive with convective initiation
on the dry line, with the other CAMs showing little if any. So
confidence remains rather low. Later Friday evening, convection is
forecast to develop along the cold front as is moves out of
northeast Colorado and sweeps across the area. There is more model
support for that convection, including the global models.
Simulated radar reflectivity forecasts suggest bowing segments
will be possible along the line with a risk for strong and
damaging wind gusts. Localized dust storms may also accompany the
line of storms. Convection marches eastward overnight and finally
exits the area after about 09z. High temperatures on Friday will
range from the upper 80s in northeast Colorado to the middle 90s
in north central Kansas, and lows Friday night will range from
around 40 in northeast Colorado to the middle 50s in north central
Kansas.
.LONG TERM...(Saturday through Thursday)
Issued at 135 PM MDT Thu Apr 21 2022
Saturday...a negatively tilted upper low pressure center over
western Nebraska in the morning is expected to lift northeast into
South Dakota by the end of the day then into Minnesota overnight.
West to northwest winds gusting 30 to 40 mph are expected during the
day with gusts around 30 mph overnight. We`ll have to watch for some
blowing dust to move into Yuma county from the northwest during the
day otherwise parameters do not favor blowing dust in the area.
There will be a slight chance for some wraparound showers and
possibly a thunderstorm generally along and west of the CO/KS border
during the day with dry conditions overnight.
High temperatures are expected to range from the lower to upper 60s
in far eastern Colorado the middle to upper 70s from Norton to
Oakley and points east. Low temperatures are expected to be in the
lower 30s to lower 40s.
Sunday...northwest winds gusting up to 35 mph are expected during
the day, decreasing overnight. Some moisture in the 700-500mb layer
moves off the Colorado front range and toward western Kit
Carson/Cheyenne counties in CO during the night. Some light rain
showers and snow showers will be possible. High temperatures will be
cooler with middle 50s to middle 60s expected. Low temperatures drop
into the middle 20s to lower 30s.
Monday...some weak upper level ridging moves over the area during
the night ahead of a low pressure system off the coast of the
Pacific Northwest. Dry conditions are expected. High temperatures
are forecast to be in the upper 50s to middle 60s with overnight
lows in the middle 30s.
Tuesday...southerly winds increase during the day with gusts up to
35 mph. Broad upper level ridging moves over the area with no
precipitation expected. High temperatures warm back up into the
lower to upper 70s with low temperatures in the lower to upper 40s.
Wednesday...large scale picture shows upper ridging over the area
with low pressure over the Pacific Northwest and off the coast of
the northeast United States. Only chance for moisture is overnight
and limited to areas such as McCook to Hill City east. With a
saturated boundary layer this moisture could be in the form of
drizzle. High temperatures continue to warm with lower to middle
80s expected. Low temperatures remain mild for late April with
middle 40s to around 50.
Thursday...GEFS showing the upper ridge axis moving east as the
trough to our northwest moves into Idaho. High temperatures continue
in the lower to middle 80s with low temperatures in the middle 40s
to around 50.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 545 PM MDT Thu Apr 21 2022
VFR conditions are anticipated to give way to IFR/LIFR conditions
this evening as low stratus (and fog.. perhaps) overspreads the
region from east ==> west.. invof a warm front. Conditions should
rapidly improve to VFR late tonight (09-12Z) as the aforementioned
front lifts northward into Nebraska. VFR conditions are
anticipated to prevail thereafter (through most of the day on
Fri). A few thunderstorms may develop late Fri afternoon and
evening. Both terminals could be affected. Confidence on
thunderstorm coverage/timing are below average. Breezy SE winds
will back to the ESE and decrease to 10-15 knots late this
evening. Winds will shift to the S in the wake of the warm frontal
passage late tonight / early Friday morning (~09-12Z). Within a
few hours after sunrise, winds will veer to the SSW and strengthen
considerably.. increasing to 25-40 knots with gusts up to 50 knots
by late morning (16-18Z). Winds may further strengthen to 30-45
knots with gusts up to 55 knots during the mid-late afternoon
(generally after 21Z).
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...High Wind Warning from 11 AM MDT /noon CDT/ Friday to midnight
MDT /1 AM CDT/ Friday night for KSZ001>004-013>016-027>029-
041-042.
Red Flag Warning from 11 AM MDT /noon CDT/ to 8 PM MDT /9 PM
CDT/ Friday for KSZ001-002-013-027.
Fire Weather Watch from Friday morning through Friday evening
for KSZ003-014-015-028-029-041-042.
CO...High Wind Warning from 11 AM Friday to midnight MDT Friday night
for COZ090>092.
Red Flag Warning from 11 AM to 8 PM MDT Friday for COZ252>254.
NE...High Wind Warning from 11 AM MDT /noon CDT/ Friday to midnight
MDT /1 AM CDT/ Friday night for NEZ079>081.
Red Flag Warning from 11 AM MDT /noon CDT/ to 8 PM MDT /9 PM
CDT/ Friday for NEZ079>081.
&&
$$
SHORT TERM...024
LONG TERM...99
AVIATION...VINCENT
Area Forecast Discussion...UPDATED
National Weather Service North Platte NE
1051 PM CDT Thu Apr 21 2022
.UPDATE...
Issued at 1049 PM CDT Thu Apr 21 2022
Drizzle associated with robust moisture advection is underway
across parts of swrn Nebraska. The forecast gets an update for
drizzle, higher dew points and temperatures overnight and Friday
morning. The update uses the RAP and HRRR models.
UPDATE Issued at 908 PM CDT Thu Apr 21 2022
A forecast update is in place for gusts of 40 to 50 mph this
evening using a blend of the 7 short term models which predict
wind gusts.
&&
.SHORT TERM...(This evening through Friday night)
Issued at 217 PM CDT Thu Apr 21 2022
Fire weather concerns return Friday as strong south winds develop
along with dry air, especially west of HWY 183. A Red Flag Warning
is in effect for tomorrow for all of western and north central
Nebraska. A fire weather section below has more detailed information
regarding the fire weather situation expected Friday.
Potent upper trough is evident on WV imagery moving onshore the
coast of Oregon and California this afternoon. Surface low pressure
is in the process of deepening along the lee of Rockies ahead of
this feature. This is causing surface winds to back to the southeast
across Kansas and Nebraska with low-level moisture beginning to
increase as upper 40s to lower 50s dew points are being advected
into the area from the lower Mississippi Valley. The higher quality
moisture remains across the Southern Plains, to the south of a warm
front that is developing across far southern Kansas. To the south of
this warm front across Oklahoma and Texas where dew points are in
the mid to upper 60s.
Warm air advection really begins to ramp up overnight tonight. As
the main surface low begins to take shape and deepen across Wyoming.
The deeper, higher quality moisture will begin to surge northward as
the low deepens. This will be accompanied by a low stratus deck that
will overspread most of the area by late tonight. Dry air aloft (H7)
atop this lower moist layer could lead to some patchy drizzle as
there is decent lift in the moist layer. Any elevated convention that
forms should mostly stay east of our immediate area, more on the
nose of the H85 jet, which veers overnight and focuses across
eastern Nebraska.
The surface low will rapidly deepen Friday as it migrates into the
Nebraska Panhandle by late afternoon. The warm front will surge
northward through the area during the early part of the day,
accompanied by the rapid increase in low-level Gulf moisture and
very strong southerly winds. It appears that by late afternoon the
warm front will extend near or just north of the NE/SD border. An
EML will overspread the area through the day Friday, and could limit
the potential convective development near the warm front. In fact,
CAMS really don`t initiate any development near the warm front and
focus more on the dry line for at least isolated convective
development around 23Z-01Z timeframe. By early evening, soundings
are very favorable for supercells along the HWY 83 corridor and
vicinity as winds in the low-levels begin to back slightly to the
southeast. This coincides with a westward retreating dry line with a
surge of at least upper 50s dew point readings into western
Nebraska. The other focus (and has the higher potential of
occurring) will be along the surging cold front that essentially
meets the westward retreating dry line mid-evening across west
central Nebraska. This is about the time that the best forcing
arrives, and should see the rapid development of a squall line take
shape along the cold front/dry line. This line is then expected to
advance quickly eastward across the area overnight. This line will
be pushing into a very favorable environment , strong southerly LLJ,
etc. It appears that the line could remain near-surface based due to
the rapid increasing low-level moisture and strong southerly winds
and mixing through the boundary layer. This scenario could lead to
the potential for an isolated tornado along the leading edge of the
line. Regardless, strong winds will be likely as 55-65 kt low level
jet could lead to gusts nearing 60 mph (even well ahead of the line)
as the strong winds mix to the surface. A High Wind Warning is in
effect to cover this potential.
.LONG TERM...(Saturday through Thursday)
Issued at 217 PM CDT Thu Apr 21 2022
The upper low will move northeast across South Dakota on Saturday.
Gusty northwest winds develop Saturday through Saturday night and
then begin to decrease on Sunday. Could have some gusts 40-45 mph
during this period before decreasing Sunday. Threat of some light
wrap-around rain or snow, especially the first half of the day
across northwest Nebraska. Potential for some minor wet
snow accumulation in the Pine Ridge area.
Upper level ridging looks to dominate the weather for much of the
upcoming week. As this occurs expect temperatures to be above normal
by the middle of the week. The airmass will be dry the first half of
the week. Some wind is expected during this time which could lead to
potentially more fire weather concerns. Upper troughing takes shape
across the western CONUS late in the week. This could allow for some
return flow of Gulf moisture through the Plains by late in the week,
possibly leading to at least a slight chance for rainfall.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 637 PM CDT Thu Apr 21 2022
VFR conditions will continue through this evening with cigs
dropping through the evening hours. After midnight MVFR and IFR
cigs are expected at both KLBF and KVTN terminals. There is the
potential for some patchy fog to develop across southwest Nebraska
and impact KLBF terminal in the morning. Strong winds will
continue through the early evening hours, diminish as sunset
approaches then becoming light overnight, around 10 to 12 kts out
of the south. There is the potential for a brief period of LLWS
across the northern Sandhills after midnight, including KVTN
terminal. South winds will increase tomorrow afternoon with gust
up to 40 kts possible.
&&
.FIRE WEATHER...
Issued at 217 PM CDT Thu Apr 21 2022
Critical fire weather conditions are likely Friday afternoon and
into the early evening hours across western and north central
Nebraska. Strong southerly winds of 25 to 40 MPH with gusts of 50
to 60 MPH are likely Friday afternoon and evening. Minimum
relative humidity will fall to as low as 10 percent in
southwestern Nebraska Friday afternoon as highs reach into the
lower 90s. In addition, thunderstorms are expected to initiate
around 6 PM CT tomorrow along highway 61 from Hyannis to Imperial.
As storms initiate, dry lighting will be possible and may lead to
fire starts. Any fires which may develop Friday have a very high
probability of rapid spread and will be very difficult to
control.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
High Wind Warning from noon CDT /11 AM MDT/ Friday to 3 AM CDT
/2 AM MDT/ Saturday for NEZ006>010-025>029-035>038-057>059-
069>071.
Red Flag Warning from noon CDT /11 AM MDT/ to 9 PM CDT /8 PM
MDT/ Friday for NEZ204-206-208>210-219.
&&
$$
UPDATE...CDC
SHORT TERM...Taylor
LONG TERM...Taylor
AVIATION...Gomez
FIRE WEATHER...Taylor
Area Forecast Discussion
National Weather Service Paducah KY
635 PM CDT Thu Apr 21 2022
.UPDATE...
Issued at 635 PM CDT Thu Apr 21 2022
Patchy light rain/sprinkles continue persist along and south of
the stationary frontal zone, generally running from north of
Perryville MO to near Henderson KY at 6 pm CDT. Weak omega,
induced by channeled vorticity impinging on the shear axis of a
dirty/low-amplitude ridge bisecting the area from northwest to
southeast, appears to be supporting the generation of isolated
showers in the WFO PAH CWA late this afternoon and early evening.
Between now and midnight, expect the frontal boundary to very
slowly lift north. The KPAH VAD Wind profile suggests that the
frontal zone is well north with evident of a departing wave near
6-8kft msl level (most likely which prompted the light rain over
the last hour at KPAH). Further to the north, the KVWX VAD wind
profile, still has the boundary to the south of the radar site.
There is a transition from easterly |flow (up to 3kft msl) to
east- southeast flow as of 6 pm, with very weak capping
dissipating in the 3-4kt msl layer.
Anticipate lift will increase during the middle and late evening
over the northern 1/3rd of the WFO PAH forecast area. Given late
afternoon differential heating, over the northern 1/3rd of the
area, the plume of 60+ dewpoints spreading northward south of the
boundary, and the weak ageostrophic wind response ahead of the
broad southwest flow over MO and KS, suspect there may be a slight
uptick in convection over the area between 7-9 pm CDT (albeit
small in coverage area), before maximizing along the I-64 corridor
between midnight and daybreak Friday.
Although initializing too far to the north, the HRRR, HRRR Time
Lagged, and High-Resolution WRF-FV3 CAM guidances seems to be
doing a reasonable job of depicting the storm scale activity over
Missouri (including the impressive severe storms over WFO SGF`s
CWA). At this point in time, will watch these storms for any
progression toward some of the southeast MO counties, but for now
anticipate any strong to severe storm activity should remain
outside the WFO PAH forecast area tonight.
Made some slight adjustments to sensible weather (wind,
temperature, dewpoint) to match observations and short term
trends. The HRRR/HRRRTL guidance again appeared to have the best
short term handle on these weather elements.
&&
.SHORT TERM...(Tonight through Saturday)
Issued at 200 PM CDT Thu Apr 21 2022
Increasing heights aloft should squash any pcpn chances, though
some light showers might squeeze out a sprinkle as warm sectoring
occurs overnight. If pcpn occurs, the best bet looks to be in our
far north, where the relative height rise/atmospheric subsidence
is least to overcome. This small chance might bleed into tmrw as
well, but we`ve silenced pops numerically by then. The main short
term forecast theme will be the warming dome of higher pressure,
on the order of 60 plus DM at H5, helping push surface temps into
the 80s and dew points into the 60s as we finish out the week and
begin the weekend. South winds will pick up tmrw and become a
little gusty at times, as the gradient tightens between the
surface high to the east, and developing low pressure to the west.
.LONG TERM...(Saturday night through Thursday)
Issued at 200 PM CDT Thu Apr 21 2022
The main focus for the long term portion of the forecast will be a
sustained period of rainfall Sunday through Monday as a result of a
slowly progressing cold front.
A strong low pressure system will be positioned in the Dakotas
Saturday evening. Gulf moisture will stream northward ahead of a
cold front, keeping temperatures elevated Saturday night with lows
in the 60s. Through the day Sunday, the low pressure system will
progress northeastward into Canada, while the cold front takes a
more SW to NE orientation as the northern end of the front moves
eastward faster than the southern end. Showers are expected Sunday,
with thunderstorms possible in the afternoon to evening hours. The
potential for severe weather Sunday afternoon-evening is low, but a
few strong storms cannot be ruled out at this time. The cold front
crosses through the Quad State Sunday night. Post-frontal
precipitation continues through Monday as the front is slow to
advance further eastward. For Sunday, WPC has a slight risk in the
extended Day 4 ERO outlook stretching from northeast Texas to the
far SW corner of Indiana. Precipitable water values are elevated but
not particularly high (order of 1.5-2 standard deviations above
climatology), so training thunderstorms/heavy rain with boundary
parallel flow will be needed for flooding issues to develop.
Following the departure of the front, dry weather and below average
temperatures are forecast for Tuesday and Wednesday as a ridge
builds into the area. There is potential for lee cyclogenesis to
develop a system east of the Rockies Wednesday, which in some
ensemble members brings precipitation to the area Wednesday night
and Thursday.
Temperatures will be well above normal ahead of the Sunday cold
front, with lows Saturday night in the 60s and highs Sunday to
around 80 except for northwestern areas that will have earlier
arrival of showers. Following the cold front, Monday highs and lows
are forecast to be in the low-to-mid 60s and low-to-mid 40s,
respectively. Temperatures will slowly trend warmer through
midweek.
&&
.AVIATION...
Issued at 635 PM CDT Thu Apr 21 2022
For the first several hours of the 00z Friday WFO PAH TAF
issuance, kept a mention of MVFR ceilings and vicinity showers
activity at KCGI, KPAH, and KOWB, eventually shifting these lower
ceilings toward KMVN and KOWB during the middle and late evening.
As the warm frontal boundary gradually moves northward of the WFO
PAH TAF sites during the mid-morning, except for KMVN, returned
all sites back to VFR conditions for the rest of the day on
Friday.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...None.
MO...None.
IN...None.
KY...None.
&&
$$
UPDATE...Smith
AVIATION...Smith
Area Forecast Discussion
National Weather Service San Diego CA
855 PM PDT Thu Apr 21 2022
.SYNOPSIS...
Cooler temperatures are expected through Friday as a fast-moving low
pressure system moves through Southern California. Winds will
increase this evening, peak overnight into Friday morning, and stay
elevated through much of the day. Scattered showers and isolated
thunderstorms will be possible late tonight into Friday morning. Dry
conditions will return for Saturday with substantial warming for
Sunday into early next week. Periods of weak to moderate Santa Ana
winds on Sunday and Monday. Cooler for Tuesday through late next
week.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
Evening Update:
No updates were needed this evening. Bands of showers out ahead of
the potent fast moving low are affecting the Central Coast and San
Joaquin Valley this evening. There have been a few thunderstorms
occurring within these bands, particularly in the Fresno area and
just off the coast from Point Conception. The most vigorous energy
with this storm will skirt past our northern areas (OC, IE, and the
SB Mountains) where our highest expected rainfall totals are
predicted. Lesser amounts are expected for the Southern IE and San
Diego County, but that said, most areas will see at least a few
hundredths of an inch from this storm, except for the lower deserts
and the Coachella Valley, which will mainly miss out on the
measurable rainfall.
Previous Discussion (issued 151 PM PDT):
At 1 PM, skies were mostly clear across Southern California, though
high clouds will filter into the region this afternoon. A fast-
moving low pressure system is churning off the coast of Oregon this
afternoon. Winds are starting to increase out ahead of this system
across the mountains and the San Gorgonio Pass, and will increase
further this afternoon across the mountains in San Bernardino and
Riverside Counties and the deserts. Winds will increase later this
afternoon into San Diego County. Wind gusts to 70 mph will be
possible, highest in wind-prone passes and canyons. Winds will
briefly diminish into Friday morning before a second surge develops
Friday afternoon. Breezy winds on 20 to 30 mph will also be felt
across coastal areas and the valleys on Friday. Winds will quickly
taper off late Friday night into Saturday morning.
Rain chances will increase this evening across northwest portions of
the CWA, expanding farther south and east tonight. CAMs show the
first showers developing late tonight, and the most widespread
activity occurring between 1 AM - 5 AM Friday across northern areas,
and 3 AM - 7 AM Friday across southern areas. The HRRR displays
modest surface-based CAPE values of 100-250 J/kg as the cells are
moving through, so thunderstorms will be possible, especially along
the cold front. The majority of the showers and thunderstorms will
be finished across the coast and valleys by sunrise on Friday, with
this activity mainly confined to the mountains in San Diego County.
Snow levels will start near 7000 FT MSL this evening before quickly
falling to 5500 FT early Friday morning. Several inches of snow are
expected, mainly above 7000 FT.
Temperatures will cool today and Friday, with highs 2 to 7 degrees
below normal for the mountains through the coast. Friday high
temperatures will be much below average from the coast through the
deserts, as much as 5 to 25 degrees below normal. Temperatures will
be noticeably warmer on Saturday.
Ridging will begin to build across the western United States on
Sunday. Breezy Santa Ana winds will develop Sunday morning and
prevail into early Monday. Winds will be out of the northeast on
Sunday favoring the San Bernardino County Mountains through the
Inland Empire, and more easterly, though weaker, on Monday, favoring
the mountains of Riverside and San Diego Counties and adjacent
valleys. These winds look weak to moderate in strength at this time.
Timing and amplitude difference exist between the ECMWF ENS and
GEFS. The EPS is slightly stronger than the GEFS therefore slightly
warmer, especially for temperatures on Monday. The ECMWF EFI is
highlighting the 60th to 80th percentile for heat for the western
valleys to the coast on Monday; temperatures are expected to reach
the upper-80s to lower-90s in these areas. Heat will also rebuild
across the lower deserts, with highs in the upper-90s. The ridge
will begin to break down into Tuesday and onshore flow returns. How
much cooling occurs depends on how fast the ridge is replaced by
longwave troughing. However, it does look like cooling will begin
across the coast and western valleys for Tuesday, with further
cooling through late next week.
&&
.AVIATION...
220325Z...Coast/Valleys...BKN low clouds will continue fill in
through the evening with bases 1500-2500 ft MSL. SHRA developing
from north to south, entering VCTY KSNA by 05Z. ISO -TSRA through
the night. BKN low clouds may lower sporadically in storms based 500-
1000 feet MSL with local visibilities around 2 miles at times 22/12Z
22/06Z - 22/12z. SCT clouds prevailing north to south in the
afternoon on Friday.
Mountains/Deserts...Higher terrain obscured in clouds based 3000 ft
MSL, increasing SHRA this evening. Slight chance of thunderstorms
22/06Z - 22/12Z in the mountains. Areas of westerly surface wind
gusts 35-45 knots with isolated gusts to 55 knots. Strongest winds
will be from the mountain crests east through the desert slopes and
into the adjacent deserts. MOD-STG up/downdrafts will occur
over/east of mtns at times, including KPSP. Winds becoming slightly
weaker but more widespread after 14Z Friday with gusts 30-40 kts for
much of the day on Friday.
&&
.MARINE...
Strong westerly winds will develop over the coastal waters early
Friday morning and continue through Friday night. Winds will be 15-
25 knots through Friday morning with gusts to 30 knots possible in
the outer coastal waters Friday afternoon and evening. This will be
accompanied by choppy seas to near 8 feet due to a combination of
the wind waves and a longer period swell up to around 5 feet/16
seconds. Some gusts around/slightly over 20 knots could occur
Saturday, Sunday and Monday afternoons/evenings. Please see the
Small Craft Advisory for more details.
There is also a slight chance of thunderstorms this evening into
early Friday.
&&
.BEACHES...
Increasing swell will bring elevated surf and strong rip currents
Friday through Saturday. A Beach Hazards Statement and the Surf Zone
Forecast contain the details. The surf will subside Sunday.
There is also a slight chance of thunderstorms tonight into Friday
morning.
&&
.SKYWARN...
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory until 3 PM PDT Friday for Apple and Lucerne
Valleys-Coachella Valley-Riverside County Mountains-San
Bernardino County Mountains-San Gorgonio Pass Near Banning.
Wind Advisory until 6 PM PDT Friday for San Diego County Deserts-
San Diego County Mountains.
Beach Hazards Statement from late tonight through Saturday
evening for Orange County Coastal Areas-San Diego County
Coastal Areas.
PZ...Small Craft Advisory from 11 PM this evening to 6 AM PDT
Saturday for Coastal Waters from San Mateo Point to the
Mexican Border and out to 30 nm-Waters from San Mateo point
to the Mexican Border Extending 30 to 60 nm out including
San Clemente Island.
&&
$$
PUBLIC...Schenk/JMB
AVIATION/MARINE/BEACHES...APR