Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 04/23/16
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
900 PM PDT FRI APR 22 2016
.SYNOPSIS....A FEW SHOWERS WILL LINGER INTO THE EVENING HOURS AND
END BY MIDNIGHT. DRY WEATHER IS EXPECTED ALONG WITH SEASONABLY
COOL TEMPERATURES THROUGH THIS WEEKEND AND INTO EARLY NEXT WEEK.
LOCALLY STRONG AND GUSTY NORTHWEST WINDS MAY OCCUR FROM LATE
SUNDAY INTO MONDAY...MAINLY NEAR THE COAST AND IN THE HILLS. THE
NEXT CHANCE OF RAIN WILL BE AROUND THE MIDDLE OF NEXT WEEK.
&&
.DISCUSSION...AS OF 9:00 PM PDT FRIDAY...POST-FRONTAL SHOWER
ACTIVITY HAS BEEN GRADUALLY TAPERING OFF SINCE EARLY EVENING.
RADAR CURRENTLY SHOWS ISOLATED LIGHT SHOWERS FROM THE CENTRAL SF
BAY AREA SOUTH TO MONTEREY COUNTY. BASED ON LATEST HRRR AND NAM
MODELS WE CAN EXPECT ALL SHOWER ACTIVITY TO END BY MIDNIGHT.
DRY WEATHER IS FORECAST OVER THE WEEKEND ALONG WITH SLIGHTLY
COOLER THAN NORMAL TEMPERATURES. AN "INSIDE SLIDER" IS FORECAST TO
DROP ACROSS NORTHEAST CALIFORNIA LATE SUNDAY AND SUNDAY NIGHT. ALL
PRECIP WITH THIS SYSTEM IS FORECAST TO REMAIN TO OUR NORTH AND
EAST. THE PRIMARY IMPACT THIS SYSTEM WILL HAVE ON OUR WEATHER WILL
BE TO GENERATE SOME LOCALLY STRONG AND GUSTY NORTHWEST WINDS FROM
LATE SUNDAY INTO MONDAY. STRONGEST WINDS BE ALONG THE COAST AND IN
THE HILLS. WINDS MAY GUST LOCALLY TO 40 MPH AND THIS MAY BE A
MARGINAL WIND ADVISORY SCENARIO. WINDS SHOULD EASE IN ALL AREAS BY
MONDAY NIGHT.
OUR NEXT POTENTIAL FOR RAINFALL WILL BE AROUND THE MIDDLE OF NEXT
WEEK WHEN A SYSTEM IS DUE TO DROP IN FROM THE NORTHWEST. THE 18Z
GFS FORECASTS WIDESPREAD SHOWER ACTIVITY WITH THIS SYSTEM FROM
WEDNESDAY AFTERNOON THROUGH WEDNESDAY NIGHT. THE LATEST ECMWF
(12Z) IS NOT AS OPTIMISTIC AS THE GFS...SHOWING ONLY ISOLATED
LIGHT QPF DURING THE SAME PERIOD OF TIME.
&&
.AVIATION...AS OF 6:12 PM PDT FRIDAY...ISOLATED SHOWERS WILL TAPER
OFF THIS EVENING. ADDITIONAL MAINLY WEAK LOWER LEVEL ATMOSPHERIC
COOLING IS FORECAST TONIGHT WHILE A MID-UPPER LEVEL HIGH PRESSURE
AREA STEADILY BUILDS OVER NORCAL TONIGHT AND SATURDAY.
VICINITY OF KSFO...VFR. SW-W WINDS GRADUALLY DECREASING THROUGH 04Z
THIS EVENING.
SFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY TERMINALS...MVFR/VFR. SW-W WINDS GRADUALLY DECREASING
THIS EVENING.
&&
.MARINE...AS OF 01:57 PM PDT FRIDAY...NORTHWESTERLY WINDS BEHIND A
DEPARTING COLD FRONT WILL SLOWLY DIMINISH TONIGHT. A SECOND COLD
FRONT WILL DROP THROUGH THE WATERS WITH INCREASING NW WIND AND
SEAS SUNDAY THROUGH EARLY NEXT WEEK. GALE FORCE WINDS ARE POSSIBLE
FOR SUNDAY NIGHT IN OUR OUTER WATERS.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...NONE
&&
$$
PUBLIC FORECAST: DYKEMA
AVIATION: CANEPA
MARINE: BELL
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK AND TWITTER AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
826 PM PDT FRI APR 22 2016
.SYNOPSIS...
The possibility of precipitation will end this evening, then a
high will build in over the weekend for breezy winds and a slight
warmup. a series of lows should then arrive next week for around
normal temperatures, with possible precipitation late next week.
&&
.SHORT TERM...(TONIGHT-MON)
An upper level trough of low pressure moved through california today.
The associated weak cold front brought some light rain showers to
portions of slo/sba counties, generally less than a tenth of an
inch. However, some isolated amounts over one half inch were
observed near Hearst Castle where there was some orographic
enhancement. As of 8 pm this evening, radar and automated gauge
data not showing any shower activity, but satellite imagery still
shows some residual clouds over portions of the forecast area.
Once the flow turns more northwest to north tonight...then
a threat of showers will develop across the north facing mountain
slopes.
The main story in the short term forecast will be winds. This
evening, center of energetic upper level low pressure system near
Lake Tahoe, and is forecasted to track eastward overnight. Behind
this system, there is plenty of upper level wind support and cold
air advection helping to generate the gusty winds at the surface.
Wind advisories in effect tonight for the mountains, Antelope
Valley, and Santa Barbara south coast, where wind gusts of 45 to
55 mph will be common.
*** from previous discussion ***
There may be a few lingering clouds early Sat, otherwise
increasingly sunny skies can be expected for the bulk of the day on
Sat. Gusty nw winds are expected along the Central Coast, in the
mtns along the I-5 Corridor, and in the Antelope Vly for Sat
afternoon and evening, and in the SBA County mtns and s cst Sat
night into early Sun. Additional wind advisories may be needed in
some of these areas as well.
Partly cloudy skies at times can be expected Sat night thru Mon as
the upper trof moves in. Clouds should once again bank up on the n
mtn slopes with a slight chance of rain or snow showers later Sun
night into Mon morning. 12Z NAM boundary lyr moisture fields were
also suggesting some low clouds and fog should develop in the
Salinas River Vly later Sun night into Mon morning. Another increase
in the onshore gradients can be expected both Sun and Mon afternoon
and evening, with gusty nw winds mainly along the Central Coast, SBA
County s cst, and in the foothills, mtns and Antelope Vly. Wind
advisory level winds will be likely at times Mon afternoon and
evening in these areas, except the Central Coast may approach
advisory levels.
Temps are forecast to warm slightly back to near normal to slightly
above normal for most areas on Sat, with little change expected for
Sun and Mon.
.LONG TERM...(TUE-FRI)
The EC/GFS are in generally good agreement with the large scale
features during the period, with only minor differences by Thu and Fri.
The upper trof extending into e central CA will move well e of the
region on Tue. Upper level troffiness will move back in from the e
Pac on Wed. A cold upper level low off the central CA cst Wed will
move se and into swrn ca on Thu, then move e of the region Thu night
and Fri.
Dry weather with breezy to windy onshore flow for the afternoon and
evening hours will continue Tue thru Wed. The GFS is more robust
with the extent of the upper low off the coast Thu compared to the
EC, and the GFS is a bit wetter than the EC for Thu. There is enough
of an increase in confidence for unsettled conditions so have
increased pops to chance levels across the forecast area Wed night
and Thu. Residual moisture and upper troffiness for Thu night into
Fri has prompted a slight chance of showers to remain in the fcst to
end the work week. If the GFS verifies with the position of the
upper low on Thu, then there would be the potential for thunderstorm
development over the area with locally heavy rainfall. This
situation will be closely monitored over the next several model
runs, but since this potential weather event is still six days away,
will not add the mention of thunderstorms just yet.
Temps will be generally near normal or slightly below normal Tue and
Wed, cool to several deg below normal for Thu, then warm slightly
Fri but still remain slightly below normal overall.
&&
.AVIATION...22/2335Z...
Marine layer at LAX at 230Z is 1500 feet deep and the inversion
top is at 6000 feet with a temp of 11 degrees C.
Upper level trough of low pressure moving across California this
afternoon, with dissipating cold front bringing isolated showers
this afternoon as far south as sba county. Otherwise, look for
sct-bkn025-050 conditions through this evening associated with
this weakening front. Gusty west-northwest winds across many
of the TAF locations, with highest gusts of 35 to 40 kt and
possible blowing dust at kpmd and kwjf through this evening.
vcnty ksba, gusty northerly winds will bring strong uddfs and
llws tonight.
KLAX and KBUR...Weakening cold front approaching from the
northwest will bring increasing low level moisture to the area,
with mostly sct020-040 conditions. chance of mvfr cigs this
evening.
&&
.MARINE...22/800 PM...
WESTERLY SCA WINDS OVER THE SOUTHERN INNER WATERS ARE EXPECTED TO
PERSIST THROUGH EARLY SATURDAY MORNING. OTHERWISE...SCA NORTHWEST
WINDS OVER THE OUTER WATERS WILL CONTINUE OVERNIGHT INTO SATURDAY
AFTERNOON...MODERATE CONFIDENCE AS WINDS ARE MARGINAL SO FAR THIS
EVENING. BUT HIGH CONFIDENCE THAT WINDS WILL INCREASE OVERNIGHT AS
STRONG HIGH PRESSURE BUILDS IN THE EASTERN PACIFIC TONIGHT THROUGH
SUNDAY. THE GALE WATCH HAS BEEN MOVED UP TO A START TIME OF 00Z
SUNDAY (5 PM SATURDAY) FOR OUTER ZONES PZZ673-676. ELSEWHERE GALES
ARE NOT EXPECTED UNTIL SUNDAY AFTERNOON/EVENING. AT THAT
TIME...STRONG GALES ARE EXPECTED WITH GUSTS UP TO 45 KNOTS FURTHER
OFFSHORE. LARGE HAZARDOUS SEAS ARE EXPECTED AS WESTERLY SWELL
COMBINES WITH LOCALLY GENERATED WIND SEAS...UP TO 15 FEET OFFSHORE
AND UP TO 12 FEET OVER THE INNER WATERS.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
CA...High Surf Advisory in effect from 5 AM Saturday to 9 PM PDT
Sunday For zones 34-35. (See LAXCFWLOX).
Wind Advisory in effect until 8 AM PDT Saturday For zones
39-52-59. (See LAXNPWLOX).
Beach Hazards Statement in effect from Saturday morning
through Sunday evening For zones 39>41-87. (See LAXCFWLOX).
Wind Advisory in effect until 10 PM PDT this evening For
zones 40-41. (See LAXNPWLOX).
Wind Advisory in effect until 8 PM PDT Saturday For zones
53-54. (See LAXNPWLOX).
PZ...Gale Watch in effect from Sunday afternoon through late
Monday night For zones 645-670. (See LAXMWWLOX).
Small Craft Advisory in effect until 3 AM PDT Saturday For
zones 650-655. (See LAXMWWLOX).
Gale Watch in effect from Sunday evening through Monday
evening For zones 650-655. (See LAXMWWLOX).
Small Craft Advisory in effect until 3 PM PDT Sunday For zone
670. (See LAXMWWLOX).
Small Craft Advisory in effect until 5 PM PDT Saturday For
zones 673-676. (See LAXMWWLOX).
Gale Watch in effect from Saturday afternoon through late
Monday night For zones 673-676. (See LAXMWWLOX).
&&
$$
PUBLIC...Gomberg
AVIATION...Gomberg
MARINE...Smith
SYNOPSIS...Sukup
weather.gov/losangeles
[top]
Area Forecast Discussion...UPDATED
National Weather Service Reno NV
736 PM PDT FRI APR 22 2016
.UPDATE...
The cold front has moved completely through western NV as of early
this evening and gradients have relaxed enough to go ahead and
drop the wind advisories and areas of blowing dust. Winds will
still be locally gusty before subsiding further this evening, but
well below earlier peaks.
Convection continues to fire over the Sacramento Valley and then
move eastward into the Tahoe Basin. Moderate to heavy snow was
falling under some of the stronger showers with roads likely to
remain a mess this evening, especially with the sun setting.
Expect another 1 to 3 inches, locally up to 4 inches this evening
before showers begin to diminish. We will continue the snow
advisory through expiration. Scattered snow showers may also
produce periods of slick roads along Hwy 395 through Mono County.
Make sure to check road conditions if you must travel tonight.
Hohmann
&&
.SYNOPSIS...
Moderate to occasionally heavy bands of snow showers will continue
across the Tahoe Basin through this evening with showers more
scattered elsewhere tonight. A break is expected Saturday before
more showers arrive Sunday into Monday. Unsettled weather will
continue through next week with below average temperatures.
&&
.PREVIOUS DISCUSSION... /Issued 303 PM PDT FRI APR 22 2016/
SYNOPSIS...
A strong Pacific storm will continue to move through the Sierra
and Western Nevada tonight. Rain and heavy mountain snow are
expected this evening near and south of I-80. A break is expected
Saturday before more showers are expected Sunday into Monday with
another system. Unsettled weather will continue through next week
with below average temperatures.
SHORT TERM...
A strong spring storm continues to move through. Heavy snow is
falling in the Sierra with rates approaching 3"/hr. It is best to
avoid travel in the Sierra for the next few hours if possible.
Heavy convective snowfall continues in the Sierra with the bands
extending from Westwood south into Bridgeport. Heavy snow is
falling above 6000 feet, with the snow level locally down to 4500
feet in the heaviest bands. Latest satellite/radar trends support
the HRRR in keeping the heaviest rain/snow going thru 03Z near and
south of I-80. After there will be a rapid reduction in showers as
the upper forcing moves east and the airmass stabilizes.
Until then, another 6+ inches of snow is possible above 7000 feet
with another 2-4" down to 5500-6000 feet. Rainfall into Western NV
will be heaviest in the Sierra front where an additional 1/4" of
rain is possible. It may mix with snow at times in the foothills
while lighter amounts are expected toward the highway 95 corridor.
Winds are much weaker along the Sierra Front with the precip
falling, but strong gusts continue east of a Bridgeport to
Lovelock line. Will cancel the advisory for Reno-Carson-Minden,
but leave the remainder as the winds continue there.
Behind this storm, a break is expected Saturday with continued
cool temps, but lighter winds and dry conditions. Another upper
low is expected Sunday afternoon into Monday. Showers are expected
Sunday afternoon with enough instability for a few thunderstorms
as well. The core of the low will move overhead Monday morning
with much colder air. Snow levels will fall to near the valley
floors. While this storm will have some moisture with it, the best
forcing is expected to remain over Eastern NV so we are not
expecting another big precip event. However, there remains a
threat (low at this time) of some light snowfall during the Monday
morning commute along the I-80 and highway 50 corridors. Wallmann
LONG TERM...Monday Night through Friday...
Unsettled weather pattern is expected to continue through next
week as late season storm systems line up to move into the West
Coast. Wednesday-Friday could be a rather wet period for much of
the region with potential for additional snow in higher
elevations.
For Monday night, the first upper low is likely to be on its way
out with lingering rain and snow showers diminishing. Tuesday
still looks like the least active weather day, although a few
showers remain possible as residual moisture will remain in place.
Even though temperatures are expected to increase about 10-15
degrees from Monday, highs in the lower 60s and around 50 degrees
near the Sierra will still be a few degrees below average for late
April.
For next Wednesday-Friday, medium range guidance continues to
indicate a potent low pressure tracking southward along the
California coast, then swing inland across the southwest US (or
possibly farther north into eastern NV). Despite this southerly
track, a broad area of upper divergence and instability is
projected to set up over the Sierra and western NV, along with a
decent tap of Pacific moisture. A few thunderstorms are also
possible each afternoon, although the better instability looks to
be trending north of I-80 by next Friday. Current projections
favor the best overall rain and snow chances Wednesday night and
higher thunderstorm potential on Thursday, but this could vary
depending on the eventual storm track. Widespread cloud cover will
keep daytime temps a few degrees below average each day, with
nighttime temps slightly above average. Early snow level
projections generally range from 6000-7000 feet in the Sierra,
although these snow levels could occasionally drop several hundred
feet during convection or heavier precip bands. MJD
AVIATION...
The most significant weather effects on aviation will continue
through this evening with IFR/LIFR cigs/vsby in snow near the
Sierra including KTVL/KTRK/KMMH, and a few inches of snow
accumulating on pavement. For lower elevations including KRNO-
KCXP, rain will produce MVFR cigs/vsby with mountain obscurations,
IFR at times during heavier rain bands. The strongest winds have
ended at KRNO-KCXP but some gusts to 35 KT remain possible. KMMH
may receive stronger gusts above 40 KT until 03z.
Later tonight, if cloud cover breaks up sufficiently, areas of
FZFG would develop across many Sierra valleys around Tahoe and
northeast CA, including KTRK. For Saturday, generally VFR
conditions are expected with lighter winds. MJD
&&
.REV Watches/Warnings/Advisories...
NV...Winter Weather Advisory until 11 PM PDT this evening NVZ002.
CA...Winter Weather Advisory until 11 PM PDT this evening CAZ072.
&&
$$
For more information from the National Weather Service visit...
http://weather.gov/reno
AREA FORECAST DISCUSSION
NWS TAUNTON MA
813 PM EDT FRI APR 22 2016
.SYNOPSIS...
A COLD FRONT OVER NEW YORK CROSSES SOUTHERN NEW ENGLAND TONIGHT
AND MOVES OFFSHORE SATURDAY. HIGH PRESSURE THEN BUILDS FOR LATER
SATURDAY AND SUNDAY BRINGING DRY AND SEASONABLE WEATHER. A FRONT WILL
PUSH SLOWLY ACROSS THE REGION MONDAY AND TUESDAY WHICH WILL BRING
MUCH NEEDED SHOWERS TO THE REGION. DRY AND SEASONABLE CONDITIONS
SHOULD MOVE IN AROUND THE MIDDLE OF NEXT WEEK. THEN A LOW PRESSURE
SYSTEM MAY BRING ADDITIONAL RAINFALL TO OUR AREA THIS UPCOMING
THURSDAY AND FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
8 PM UPDATE...
THE CONVECTION HAS DIMINISHED SUBSTANTIALLY DURING THE PAST 1 1/2
HOURS. COULD STILL POTENTIALLY HAVE A FEW RUMBLES OF THUNDER
WITHIN THE AREA INTO MID EVENING...ESPECIALLY LOWER CT VALLEY
AREA...BUT OTHERWISE ANTICIPATING WIDELY SCATTERED SHOWERS THRU
LATE EVENING. CLOUDY SKIES REMAIN...WITH PATCHY FOG DEVELOPING
CAPE/ISLANDS WHERE MARINE STRATUS IS DEVELOPING. UPDATED
TEMPERATURES TO REFLECT LATEST TRENDS.
AT 8 PM THE COLD FRONT EXTENDED FROM NORTHERN VT...SOUTHWESTWARD
THRU EASTERN NY STATE...AND INTO NORTHERN PA. BASED ON LATEST
MESOSCALE GUIDANCE...THE FRONT IS EXPECTED TO REACH WESTERN MA
AROUND 03Z...CENTRAL MA AROUND 05Z...THEN EASTERN MA/RI 08-10Z.
MEANWHILE...AN OPEN SHORTWAVE OVER OHIO IS MOVING EAST AND WILL
REACH THE MID ATLANTIC COAST BY SATURDAY MORNING. THE SHORTWAVE IS
SUPPORTED BY AN 85-KNOT JET THAT WILL OVERLAY NEW JERSEY AND LONG
ISLAND OVERNIGHT. THIS SHORTWAVE MAY TURN THE UPPER FLOW MORE
PARALLEL TO THE SURFACE COLD FRONT...SLOWING THE FORWARD PROGRESS
OF THAT FRONT. THE SHORTWAVE AND JET MAY ALSO GENERATE A WAVE
ALONG THE FRONT OVERNIGHT. BOTH THE GFS AND HRRR ARE HINTING AT
THIS. THE ECMWF SURFACE MSLP FIELD SHOWS A BAGGINESS SOUTH OF NEW
ENGLAND AT 12Z SAT THAT ALSO HINTS AT THIS.
DEW POINTS HAVE CLIMBED INTO THE 50S. WATER TEMPERATURES ARE IN
THE MID TO UPPER 40S. THIS COOLING OF THE MOIST AIR MAY CREATE
AREAS OF FOG THAT WOULD AFFECT THE SOUTH COAST.
THE CHANCE OF SHOWERS WILL CONTINUE FOR MUCH OF THE AREA
OVERNIGHT...DUE TO THE FRONTAL PASSAGE AS WELL AS THE THE UPPER
SHORTWAVE AND JET. MAINTAINING CHANCE POPS THROUGH THE NIGHT MOST
PLACES AND CARRY LIKELY POPS ALONG/SOUTH OF A HARTFORD- PROVIDENCE
LINE. WITH DEW POINTS IN THE UPPER 40S AND 50S...EXPECT MIN TEMPS
IN THIS SAME RANGE.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
UPPER TROUGH MOVES EAST OF NEW ENGLAND SATURDAY AND PUSHES THE
SURFACE FRONT WELL SOUTH OF OUR AREA. LEFTOVER SHOWERS...MAINLY
OVER RI/SOUTHEAST MASS...SHOULD MOVE OFF WITH THE TROUGH. HIGH
PRESSURE OVER CANADA WILL BUILD INTO NEW ENGLAND BRINGING DRIER
AIR AND CLEARING SKIES. MIXING IS FORECAST TO 900 MB...POSSIBLY A
LITTLE HIGHER. TEMPS AT THAT HEIGHT WOULD SUPPORT MAX SFC TEMPS IN
THE 60S. WINDS IN THE MIXED LAYER WILL BE 15-20 KNOTS...WHICH MAY
BE MIXED TO THE SURFACE IN GUSTS.
AS THE HIGH BUILDS IN...THE PRESSURE GRADIENT WILL LESSEN. NOT
CLEAR WHETHER IT WILL DIMINISH ENOUGH TO ALLOW THE SURFACE AIR TO
DECOUPLE AND ALLOW RADIATIONAL COOLING. DEW POINTS WILL FALL INTO
THE 20S...WHICH WOULD BE QUITE A CHILLY START TO THE DAY IF MINS
REACHED THAT LOW. WE WILL ALLOW A LIGHT NORTH WIND OVERNIGHT AND
KEEP TEMPS ABOVE FREEZING MOST PLACES. THE BEST CHANCE OF
DECOUPLING AND RADIATIONAL COOLING WILL BE IN THE VALLEYS OF
NORTHERN AND WESTERN MASS...WHERE THERE WILL BE THE BEST CHANCE OF
DIPPING BELOW 30. WE WILL NEED TO MONITOR THIS...SUCH COOLING MAY
BE ABLE TO EXTEND FARTHER SOUTH AND EAST.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
OVERVIEW...
LONG WAVE TROUGH ALONG THE EASTERN SEABOARD EARLY THIS WEEKEND
WILL SHIFT E AS OVERALL NORTH AMERICAN UPPER LEVEL STEERING
CURRENTS REMAIN PROGRESSIVE. BROAD H5 VORTEX ELONGATES FROM THE
ARCTIC CIRCLE INTO LABRADOR AND NEWFOUNDLAND BY SUNDAY...WITH THE
BASE OF THE VORTEX KEEPING A FAST W-NW UPPER FLOW ACROSS THE
REGION FOR MOST IF NOT ALL OF THE UPCOMING WEEK. THE NEXT
APPROACHING FRONT WILL MOVE INTO THE REGION BY THE BEGINNING OF
THE WORK WEEK AND...AS IT BECOMES PARALLEL TO THE UPPER FLOW...WILL
SEE MUCH NEEDED RAIN SHOWERS MOVE ACROSS AS THE FRONT SLOWLY PUSHES
OFFSHORE.
CANADIAN HIGH PRESSURE BRINGS DRY CONDITIONS WEDNESDAY. THEN LOW
CONFIDENCE ON THE TIMING AND TRACK AS A QUICK MOVING LOW PRESSURE
SYSTEM THAT SHOULD APPROACH THE REGION OUT OF THE OHIO VALLEY AND
SOUTHERN GREAT LAKES TOWARDS THE END OF THE UPCOMING WORKWEEK.
DETAILS...
SUNDAY...MODERATE TO HIGH CONFIDENCE.
HIGH PRESSURE PASSES OVERHEAD DURING THE DAY. ANTICIPATE MOSTLY
SUNNY SKIES...THOUGH THE FRONT TO THE NORTHWEST OF OUR AREA MAY
ALLOW FOR SOME AFTERNOON CIRRUS AND MID DECK CLOUDS. SEA BREEZES ARE
LIKELY ALONG THE COAST BY THE AFTERNOON. TEMPS NEAR NORMAL TO A FEW
DEGREES BELOW NORMAL.
SUNDAY NIGHT THROUGH TUESDAY...MODERATE CONFIDENCE.
CLOUDS WILL CONTINUE TO INCREASE SUNDAY NIGHT AS A COLD FRONT MOVES
OUT OF N NY STATE AND NORTHERN NEW ENGLAND. THE FRONT WILL MOVE
SLOWLY TO THE SOUTHEAST...BUT LOOKS LIKE IT WILL REMAIN DRY THROUGH
AT LEAST MIDNIGHT. THE POTENTIAL EXISTS FOR A FEW SHOWERS LATE
SUNDAY NIGHT...MAINLY ACROSS N MA.
THE FRONT LOOKS TO SLOW ITS FORWARD PROGRESS AS IT BECOMES PARALLEL
TO THE UPPER LEVEL WIND FLOW DURING MONDAY. CONTINUE TO EXPECT A
COUPLE OF WAVES OF LOW PRES MOVE ALONG THE FRONT...WHICH WILL ALSO
TEND TO SLOW THE FRONT DOWN. STARTING TO SEE A BIT MORE MOISTURE
CONVERGENCE SETTING UP AS THE FRONT CROSSES...ESPECIALLY MONDAY
NIGHT AND TUESDAY...BRINGING SOME MUCH NEEDED RAINFALL.
FORECAST QPF AMOUNTS LOOK TO BE ON THE ORDER OF 0.5 TO 1 INCH FROM
MONDAY AFTERNOON INTO TUESDAY.
AS THE FRONT CROSSES THE REGION LATE MON NIGHT AND TUESDAY...
COOLER AIR WORKS IN AS WINDS SHIFT TO N AND NE. HIGHS WILL BE CLOSE
TO SEASONAL NORMALS ON MONDAY...BUT WILL FALL DOWN TO SEVERAL
DEGREES BELOW SEASONAL LEVELS ON TUESDAY.
TUESDAY NIGHT AND WEDNESDAY...MODERATE CONFIDENCE.
THE FRONT SHOULD PUSH SOUTH OF OUR AREA DURING TUESDAY NIGHT...WITH
CANADIAN HIGH PRESSURE BUILDING SOUTHEASTWARD. HAVE VERY LOW CHANCE
POPS TO START TUESDAY NIGHT. OTHERWISE EXPECT CLEARING SKIES
TUESDAY NIGHT.
FAST FLOW ALOFT WILL PUSH HIGH PRES ACROSS THE REGION ON
WEDNESDAY WITH DRY BUT COOL CONDITIONS. MOSTLY SUNNY SKIES FORECAST.
WEDNESDAY NIGHT THRU FRIDAY...LOW CONFIDENCE.
A LOT OF QUESTIONS REMAIN ON THE TIMING OF A FAST MOVING LOW
PRESSURE SYSTEM THAT IS EXPECTED TO AFFECT OUR AREA DURING
THIS TIMEFRAME. AT THIS POINT HAVE DRY CONDITIONS FOR MOST OF WED
NIGHT...FOLLOWED BY CHANCE TO SLIGHT CHANCE POPS FOR SHOWERS THU
INTO FRI.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH SATURDAY NIGHT/...
00Z UPDATE...MODERATE CONFIDENCE. VFR MOST AREAS THROUGH
MIDNIGHT. WIDELY SCATTERED SHOWERS THIS EVENING...WITH AN ISOLATED
T-STORM OR TWO POSSIBLE MAINLY IN THE CT RIVER VALLEY AREA IN MA
AND NORTHERN CT. SOME SHOWERS MAY BRIEFLY LOWER CIGS AND VSBYS TO
MVFR. ALONG THE CAPE AND ISLANDS...CIGS AND VSBYS LOWERING...WITH
IFR DEVELOPING DUE TO MARINE STRATUS.
OVERNIGHT...MODERATE CONFIDENCE. ANOTHER AREA OF SHOWERS WILL
MOVE UP FROM THE SOUTHWEST AFTER MIDNIGHT. EXPECT VFR CIGS TO
LOWER TO MVFR OVERNIGHT WITH SOME PATCHY FOG AND SCATTERED
SHOWERS...WHILE SOUTH COASTAL NEW ENGLAND WILL LOWER TO IFR OR
LIFR IN SHOWERS AND DEVELOPING FOG.
SATURDAY AND SATURDAY NIGHT...MODERATE CONFIDENCE. MVFR CIGS CT
VALLEY AREA IMPROVE TO VFR BY MIDDAY IN THE WEST. ELSEWHERE...
CIGS/VSBYS MVFR TO START...EXCEPT IFR CAPE/ISLANDS...WITH GRADUAL
IMPROVEMENT TO VFR DURING THE DAY. NORTH WIND AROUND 10 KNOTS WITH
POTENTIAL GUSTS NEAR 20 KNOTS SATURDAY AFTERNOON. WINDS DIMINISH
TOWARD EVENING. VFR SATURDAY NIGHT.
KBOS TERMINAL...MODERATE CONFIDENCE. VFR CONDITIONS THIS
EVENING...WITH MVFR CIGS AND SCATTERED SHOWERS EXPECTED TO
DEVELOP AFTER 06Z. MVFR CIGS MAY LINGER WELL INTO SATURDAY.
KBDL TERMINAL...MODERATE CONFIDENCE. MAINLY VFR. HOWEVER...BRIEF
LOWER CONDITIONS POSSIBLE THIS EVENING IN SCATTERED SHOWERS AND
PERHAPS A THUNDERSTORM. ALSO A PERIOD OF MVFR CIGS POSSIBLE
OVERNIGHT...WHICH SHOULD QUICKLY IMPROVE TO VFR DURING SATURDAY
MORNING.
OUTLOOK /SUNDAY THROUGH WEDNESDAY/...
SUNDAY AND SUNDAY NIGHT...HIGH CONFIDENCE. VFR SUNDAY INTO SUNDAY
EVENING. MAY SEE MVFR CIGS/VSBYS MOVE INTO NORTHERN AREAS MAINLY
NEAR AND N OF THE MASS PIKE AFTER MIDNIGHT SUNDAY NIGHT.
MONDAY AND TUESDAY...MODERATE CONFIDENCE. AREAS OF MVFR
CIGS/VSBYS IN SHOWERS AND PATCHY FOG. CONDITIONS SHOULD IMPROVE
FROM N-S TUE NIGHT...THOUGH TIMING IS IN QUESTION.
WEDNESDAY...MODERATE CONFIDENCE. VFR.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH SATURDAY NIGHT/...
TONIGHT...MODERATE TO HIGH CONFIDENCE.
PERSISTENT SOUTHWEST FLOW AHEAD OF A COLD FRONT WILL REMAIN BELOW
20 KNOTS. THE PERSISTENT FLOW WILL BUILD SEAS A LITTLE WITH 5 FOOT
HEIGHTS ON THE OUTER WATERS SOUTH OF THE ISLANDS. SMALL CRAFT
ADVISORY CONTINUES ON THOSE WATERS. AREAS OF FOG DEVELOP DURING
THE NIGHT WHICH MAY BECOME LOCALLY DENSE...RESULTING IN POOR
VISIBILITY. WINDS WILL SHIFT LATER AT NIGHT AND COME FROM THE
NORTH OR NORTHWEST.
SATURDAY AND SATURDAY NIGHT...NORTH WINDS WITH GUSTS TO 20 KNOTS
SATURDAY AND 20 TO 25 KNOTS SATURDAY NIGHT. SEAS WILL BE 3-4 FEET
SATURDAY. HEIGHTS OF 4-6 FEET POSSIBLE ON THE EASTERN OUTER WATERS
SATURDAY NIGHT. A SMALL CRAFT ADVISORY MAY BE NEEDED ON SOME OF
THE WATERS.
OUTLOOK /SUNDAY THROUGH WEDNESDAY/...
SUNDAY...MODERATE CONFIDENCE. N WINDS VEERING TO THE SE ON SUNDAY.
GUSTS UP TO 25 KT POSSIBLE DURING THE MORNING...MAINLY ALONG THE
OUTER COASTAL WATERS. LINGERING 5 FOOT SEAS ON THE OUTER COASTAL
WATERS SHOULD GRADUALLY SUBSIDE DURING THE DAY.
MONDAY...MODERATE CONFIDENCE.
WINDS AND SEAS BELOW SCA THRESHOLDS. MAY SEE VSBY RESTRICTIONS IN
SCATTERED SHOWERS AND PATCHY FOG MONDAY.
MONDAY NIGHT AND TUESDAY...LOW TO MODERATE CONFIDENCE.
COLD FRONT SLOWLY MOVES FROM N TO S ACROSS THE WATERS. S WINDS
BECOME N DURING MON NIGHT/TUE. THEN THE N WINDS MAY GUST UP TO 20 KT
DURING TUE. SEAS BUILD UP TO 5-6 FT ACROSS THE SOUTHERN WATERS
MONDAY NIGHT AND TUESDAY...AND MAY REACH TO E OF CAPE COD DURING
TUESDAY. SHOULD HAVE SUBSIDING SEAS TUESDAY NIGHT. VSBY RESTRICTIONS
IN SHOWERS AND PATCHY FOG.
WEDNESDAY...MODERATE CONFIDENCE.
WINDS/SEAS BELOW SCA THRESHOLDS.
&&
.FIRE WEATHER...
SATURDAY...WIDELY SCATTERED SHOWERS MAY LINGER ACROSS SE MA/E RI
SATURDAY MORNING WITH N-NW WIND GUSTS UP TO 20 MPH. THESE SHOULD
PUSH OFFSHORE BY MIDDAY. DRY CONDITIONS WILL TAKE OVER SATURDAY
AFTERNOON WITH NORTH TO NORTHWEST WINDS USHERING LOWERING
DEWPOINTS. MINIMUM RELATIVE HUMIDITIES WILL BE FROM 25 TO 40
PERCENT NORTH AND WEST OF I-95 AND 40 TO 60 PERCENT TO THE SOUTH
AND EAST.
SUNDAY...HIGH PRESSURE WILL MOVE ACROSS THE REGION. LIGHT N WINDS AT
5 TO 10 MPH WILL BECOME SW DURING THE AFTERNOON...WITH SEA BREEZES
PROBABLE. MINIMUM RH VALUES WILL BE FROM 20 TO 30 PERCENT FOR MUCH
OF THE AREA...EXCEPT 35 TO 45 PERCENT ALONG THE IMMEDIATE COAST.
MONDAY AND TUESDAY...A SLOW MOVING FRONT COULD BRING A SOAKING
RAINFALL TO SOUTHERN NEW ENGLAND. THE BEST CHANCE FOR APPRECIABLE
RAIN IS MONDAY AFTERNOON THRU TUESDAY MORNING. AT THIS TIME THE
POTENTIAL EXISTS FOR 0.5 TO AROUND 1.0 INCH OF RAINFALL.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT SATURDAY FOR ANZ255-256.
&&
$$
SYNOPSIS...WTB/NMB
NEAR TERM...WTB/NMB
SHORT TERM...WTB
LONG TERM...NMB
AVIATION...WTB/NMB
MARINE...WTB/NMB
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
225 PM EDT THU APR 21 2016
.SYNOPSIS...
SURFACE HIGH PRESSURE OFF THE COAST WITH A MOIST SOUTHERLY FLOW
ACROSS THE REGION TODAY. AN APPROACHING COLD FRONT WILL CROSS THE
AREA FRIDAY NIGHT. SHOWERS AND THUNDERSTORMS EXPECTED AHEAD OF THE
FRONT ON FRIDAY. DRY HIGH PRESSURE WILL BUILD INTO THE REGION
LATE SATURDAY THROUGH TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE UPPER RIDGE WILL SHIFT OFF THE EAST COAST THIS AFTERNOON
CREATING A MORE S/SW FLOW REGIME AND MODERATE WARM ADVECTION
ACROSS THE REGION. SKIES WILL BE PARTLY CLOUDY THIS AFTERNOON
WITH HIGHS IN THE LOW TO MID 80S.
HIGH RESOLUTION MODELS SHOW A SEA BREEZE BOUNDARY MOVING INLAND
LATE THIS AFTERNOON/EVENING. MID LEVEL DRY AIR AND A SMALL
CAPPING INVERSION WILL LIMIT CONVECTIVE DEVELOPMENT. HRRR MODEL
RUNS INDICATE SCATTERED TO ISOLATED SHOWERS DEVELOPING ALONG THE
COAST.
CLOSED UPPER LOW WILL CONTINUE TRACKING EASTWARD TOWARDS THE
REGION OVERNIGHT WITH A COLD FRONT MOVING EAST OF THE MISSISSIPPI
RIVER. THIS PUTS THE REGION IN THE WARM SECTOR OF THE NEXT SYSTEM.
LOW-LEVEL FLOW OVERNIGHT WILL BE OUT OF THE SOUTH TO SOUTHWEST...
ALLOWING FOR AN INCREASE IN MOISTURE. DO EXPECT THE EARLY PART OF
TONIGHT TO BE DRY...THEN SHOULD SEE AN INCREASE IN POPS FROM WEST
TO EAST AFTER MIDNIGHT. MILD TEMPERATURES TONIGHT WITH LOWS MAINLY
IN THE LOWER 60S.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
MOST PLACES LOOK TO GET WET ON FRIDAY AS A MODERATE STRENGTH UPPER
TROF AND ASSOCIATED COLD FRONT APPROACHES FROM THE WEST. DEEP
MOISTURE FLOW AHEAD OF THE SYSTEM SHOULD RAISE PWS TO AROUND 1.5
INCHES ACROSS THE CWA...AND DECENT LIFT DUE TO DIFFERENTIAL
VORTICITY ADVECTION IN MID LEVELS AND UPPER LEVEL JET DIVERGENCE
WILL PRODUCE WIDESPREAD SHOWERS WITH A FEW THUNDERSTORMS. THERE
WILL BE SOME MODEST LOW LEVEL CAPE WITH VALUES POTENTIALLY AS HIGH
AS 1000 J/KG...BUT DEEP LAYERED SHEAR IS NOT TOO IMPRESSIVE...SO
THE THREAT FOR SEVERE WEATHER LOOKS LOW. QPF WILL GENERALLY BE 1/2
INCH OR LESS...BUT PLACES THAT DO SEE SOME
THUNDERSTORMS...ESPECIALLY IN THE SOUTHEASTERN THIRD OF THE
CWA...COULD GET LOCALLY UP TO AN INCH. TEMPS SHOULD BE SEASONABLY
WARM IN THE UPPER 70S DESPITE CLOUD COVER AS THERE WILL BE LOW
LEVEL WARM ADVECTION AHEAD OF THE COLD FRONT.
FRIDAY NIGHT...THE BEST OF THE UPPER SUPPORT SHOULD MOVE THROUGH
QUICKLY...AS WILL THE COLD FRONT. SHOWERS WILL END FROM WEST TO
EAST DURING THE EVENING...WITH JUST A FEW LINGERING IN THE
SOUTHEAST AFTER MIDNIGHT. TEMPS WILL DROP DOWN INTO THE UPPER
50S...NOT PARTICULARLY COOL AS CLOUDS WILL NOT CLEAR UNTIL LATE
AND WINDS WILL REMAIN UP.
SATURDAY SHOULD BE MOSTLY DRY AS THE FRONT MOVES OFFSHORE. I CANT
RULE OUT A SHOWER IN THE NORTHEAST AS ANOTHER SPOKE OF ENERGY
DROPS INTO NORTH CAROLINA...BUT CHANCES LOOK TOO LOW AT THIS TIME
TO MENTION IN THE FORECAST. TEMPS WILL BE SEASONABLE WITH MID 70S
NORTH TO NEAR 80 IN THE CSRA.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
A SURFACE AREA OF HIGH PRESSURE WILL MOVE INTO THE SOUTHEAST FROM
SUNDAY INTO TUESDAY...KEEPING THE CWA DRY. THE AIR MASS WILL WARM
UP UNDER SUN ANGLE EQUIVALENT TO LATE AUGUST...WITH MAX TEMPS IN
THE LOWER TO MID 80S ON SUNDAY TO THE UPPER 80S TO NEAR 90 ON
TUESDAY. A COLD FRONT WILL APPROACH THE AREA FROM THE NORTH ON
WEDNESDAY...BUT IT IS TOO EARLY TO TELL IF IT WILL STALL JUST
NORTH OF THE CWA OR MAKE IT INTO THE CWA. MOST OF THE MID AND
UPPER LEVEL JET ENERGY WILL STAY TO THE NORTH IN EITHER CASE...BUT
A CLOSER FRONT COULD MEAN A BETTER CHANCE OF DIURNAL CONVECTION
WITH MAX TEMPS WELL UP INTO THE 80S.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
HIGH CONFIDENCE FOR VFR CONDITIONS THROUGH THIS EVENING.
SOUTHERLY FLOW ACROSS THE REGION BETWEEN HIGH PRESSURE OFF THE
COAST AND APPROACHING COLD FRONT WILL BRING INCREASING MOISTURE TO
THE REGION. VFR THIS AFTERNOON AND EVENING WITH CLOUDS BASES AT OR
ABOVE 5000 FEET. MVFR/IFR CIGS FORECAST TO DEVELOP 06Z-13Z WITH
INCREASING LOW LEVEL MOISTURE UNDER NOCTURNAL INVERSION. SCATTERED
SHOWERS EXPECTED TO DEVELOP AFTER 06Z IN WEAKLY UNSTABLE AIRMASS.
CONVECTION SHOULD INCREASE IN COVERAGE AND INTENSITY FRIDAY AFTERNOON.
LOW LEVEL WIND SHEAR POSSIBLE 04Z-12Z AS A LOW LEVEL JET DEVELOPS
OVER THE REGION. HAVE NOT INCLUDED LOW LEVEL WIND SHEAR IN TAFS AT
TIME GIVEN LOW CONFIDENCE.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE FRIDAY INTO
FRIDAY EVENING FROM LOW CLOUDS/SHOWERS/ISOLATED THUNDERSTORMS
AHEAD OF THE FRONT. CONDITIONS WILL IMPROVE BY SATURDAY...WITH VFR
EXPECTED INTO EARLY NEXT WEEK.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
&&
$$
SYNOPSIS...99
NEAR TERM...99
SHORT TERM...99
LONG TERM...99
AVIATION...99
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
201 PM EDT THU APR 21 2016
.SYNOPSIS...
SURFACE HIGH PRESSURE OFF THE COAST WITH A MOIST SOUTHERLY FLOW
ACROSS THE REGION TODAY. AN APPROACHING COLD FRONT WILL CROSS THE
AREA FRIDAY NIGHT. SHOWERS AND THUNDERSTORMS EXPECTED AHEAD OF THE
FRONT ON FRIDAY. DRY HIGH PRESSURE WILL BUILD INTO THE REGION
LATE SATURDAY THROUGH TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE UPPER RIDGE WILL SHIFT OFF THE EAST COAST THIS AFTERNOON
CREATING A MORE S/SW FLOW REGIME AND MODERATE WARM ADVECTION
ACROSS THE REGION. SKIES WILL BE PARTLY CLOUDY THIS AFTERNOON
WITH HIGHS IN THE LOW TO MID 80S.
HIGH RESOLUTION MODELS SHOW A SEA BREEZE BOUNDARY MOVING INLAND
LATE THIS AFTERNOON/EVENING. MID LEVEL DRY AIR AND A SMALL
CAPPING INVERSION WILL LIMIT CONVECTIVE DEVELOPMENT. HRRR MODEL
RUNS INDICATE SCATTERED TO ISOLATED SHOWERS DEVELOPING ALONG THE
COAST.
CLOSED UPPER LOW WILL CONTINUE TRACKING EASTWARD TOWARDS THE
REGION OVERNIGHT WITH A COLD FRONT MOVING EAST OF THE MISSISSIPPI
RIVER. THIS PUTS THE REGION IN THE WARM SECTOR OF THE NEXT SYSTEM.
LOW-LEVEL FLOW OVERNIGHT WILL BE OUT OF THE SOUTH TO SOUTHWEST...
ALLOWING FOR AN INCREASE IN MOISTURE. DO EXPECT THE EARLY PART OF
TONIGHT TO BE DRY...THEN SHOULD SEE AN INCREASE IN POPS FROM WEST
TO EAST AFTER MIDNIGHT. MILD TEMPERATURES TONIGHT WITH LOWS MAINLY
IN THE LOWER 60S.
&&
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
UPPER TROUGH MOVING THROUGH THE EASTERN CONUS ON FRIDAY WILL
DRIVE COLD FRONT TOWARD THE REGION THROUGH THE DAY. EXPECT MAINLY
SHOWERS EARLY IN THE DAY FRIDAY...WITH POTENTIAL FOR ISOLATED
THUNDERSTORMS IN THE AFTERNOON AS THE AIR MASS BECOMES WEAKLY TO
MODERATELY UNSTABLE. STRONGER CONVECTION MORE LIKELY WEST OF THE
REGION BACK IN NORTHWEST GEORGIA. DECREASING POPS THROUGH THE
NIGHT FRIDAY INTO SATURDAY MORNING AS FRONT MOVES THROUGH THE
AREA. DRY CONDITIONS ONCE AGAIN FOR SATURDAY. GUIDANCE
TEMPERATURES THROUGH THE PERIOD SEEM REASONABLE.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
DRY HIGH PRESSURE TO SETTLE INTO THE CWA FROM SATURDAY THROUGH
MONDAY. MOISTURE INCREASE MID WEEK AND ANOTHER FRONT POSSIBLY
MOVING SOUTH FROM THE NORTH MAY LEAD TO ISOLATED OR SCATTERED
AFTERNOON SHOWERS TUESDAY AND WEDNESDAY. TEMPERATURES SHOULD BE AT
OR ABOVE NORMAL THROUGH THE PERIOD.
&&
.AVIATION /18Z THURSDAY THROUGH MONDAY/...
HIGH CONFIDENCE FOR VFR CONDITIONS THROUGH THIS EVENING.
SOUTHERLY FLOW ACROSS THE REGION BETWEEN HIGH PRESSURE OFF THE
COAST AND APPROACHING COLD FRONT WILL BRING INCREASING MOISTURE TO
THE REGION. VFR THIS AFTERNOON AND EVENING WITH CLOUDS BASES AT OR
ABOVE 5000 FEET. MVFR/IFR CIGS FORECAST TO DEVELOP 06Z-13Z WITH
INCREASING LOW LEVEL MOISTURE UNDER NOCTURNAL INVERSION. SCATTERED
SHOWERS EXPECTED TO DEVELOP AFTER 06Z IN WEAKLY UNSTABLE AIRMASS.
CONVECTION SHOULD INCREASE IN COVERAGE AND INTENSITY FRIDAY AFTERNOON.
LOW LEVEL WIND SHEAR POSSIBLE 04Z-12Z AS A LOW LEVEL JET DEVELOPS
OVER THE REGION. HAVE NOT INCLUDED LOW LEVEL WIND SHEAR IN TAFS AT
TIME GIVEN LOW CONFIDENCE.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE FRIDAY AFTERNOON
THROUGH EARLY SATURDAY AS A COLD FRONT CROSSES THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
750 AM EDT THU APR 21 2016
.SYNOPSIS...
THE FRONTAL BOUNDARY WILL SHIFT BACK TO THE NORTHEAST TODAY.
ANOTHER COLD FRONT WILL CROSS THE AREA FRIDAY NIGHT. DRY HIGH
PRESSURE WILL BUILD BACK INTO THE REGION LATE SATURDAY THROUGH
TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE UPPER RIDGE WILL SHIFT OFF THE EAST COAST CREATING A MORE
S/SW FLOW REGIME AND MODERATE WARM ADVECTION ACROSS THE REGION.
THE STALLED FRONTAL BOUNDARY WILL LIFT TO THE NORTHEAST OUT OF THE
FORECAST AREA (FA) TODAY. UPPER LEVEL MOISTURE ADVECTION AND HIGH
CLOUDS WILL CONTINUE TO FLOW OVER THE REGION. DESPITE PARTLY
CLOUDY SKIES...LOCAL FORECAST TOOLS FAVOR THE WARMER TEMPERATURE
GUIDANCE DUE TO WARM ADVECTION AHEAD OF THE COLD FRONT. EXPECT
HIGHS IN THE LOW TO MID 80S.
HI RESOLUTION MODELS SHOW A SEA BREEZE BOUNDARY MOVING INLAND
INTO THE WESTERN FA LATE THIS AFTERNOON/EVENING. MID LEVEL DRY AIR
AND A SMALL CAPPING INVERSION WILL LIMIT CONVECTIVE DEVELOPMENT.
RECENT HRRR MODEL RUNS INDICATE SCATTERED TO ISOLATED SHOWERS
DEVELOPING ALONG THE COAST. WRF-ARW AND NMM MODELS ALSO KEEP
SHOWERS WEST OF THE AREA INCREASING CONFIDENCE IN A DRY FORECAST.
CLOSED UPPER TROUGH WILL CONTINUE TRACKING EASTWARD TOWARDS THE
REGION OVERNIGHT. SURFACE WARM FRONT SHOULD BE NORTH OF THE CWA TO
START THE PERIOD...WITH THE MAIN COLD FRONT STILL MOVING EAST OF
THE MISSISSIPPI RIVER. THIS PUTS THE REGION IN THE WARM SECTOR OF
THE NEXT SYSTEM. LOW-LEVEL FLOW OVERNIGHT WILL BE OUT OF THE
SOUTH TO SOUTHWEST...ALLOWING FOR AN INCREASE IN MOISTURE. DO
EXPECT THE EARLY PART OF TONIGHT TO BE DRY...THEN SHOULD SEE AN
INCREASE IN POPS FROM WEST TO EAST AFTER MIDNIGHT.
&&
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
UPPER TROUGH MOVING THROUGH THE EASTERN CONUS ON FRIDAY WILL
DRIVE COLD FRONT TOWARD THE REGION THROUGH THE DAY. EXPECT MAINLY
SHOWERS EARLY IN THE DAY FRIDAY...WITH POTENTIAL FOR ISOLATED
THUNDERSTORMS IN THE AFTERNOON AS THE AIR MASS BECOMES WEAKLY TO
MODERATELY UNSTABLE. STRONGER CONVECTION MORE LIKELY WEST OF THE
REGION BACK IN NORTHWEST GEORGIA. DECREASING POPS THROUGH THE
NIGHT FRIDAY INTO SATURDAY MORNING AS FRONT MOVES THROUGH THE
AREA. DRY CONDITIONS ONCE AGAIN FOR SATURDAY. GUIDANCE
TEMPERATURES THROUGH THE PERIOD SEEM REASONABLE.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
DRY HIGH PRESSURE TO SETTLE INTO THE CWA FROM SATURDAY THROUGH
MONDAY. MOISTURE INCREASE MID WEEK AND ANOTHER FRONT POSSIBLY
MOVING SOUTH FROM THE NORTH MAY LEAD TO ISOLATED OR SCATTERED
AFTERNOON SHOWERS TUESDAY AND WEDNESDAY. TEMPERATURES SHOULD BE AT
OR ABOVE NORMAL THROUGH THE PERIOD.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
ONSHORE FLOW BROUGHT LOW LEVEL MOISTURE TO AREA PRODUCING
IFR/MVFR CONDITIONS. LOW CLOUDS/FOG EXPECTED TO MIX OUT 14Z-15Z
AS INVERSION BREAKS AND WIND INCREASE. A COLD FRONT APPROACHING
FROM THE WEST AND A TIGHTENING PRESSURE GRADIENT WILL CREATE GUSTY
WINDS FROM MID-MORNING ON. BUFKIT FORECAST SOUNDINGS INDICATE THE
POTENTIAL FOR GUSTS 20 TO 25 KNOTS DURING THE AFTERNOON HOURS.
MODELS SUPPORT SHOWERS DEVELOPING AHEAD OF THE APPROACHING COLD
FRONT. THESE SHOWERS MAY REACH THE CENTRAL MIDLANDS AND CSRA TAF
SITES NEAR THE END OF THE TAF PERIOD...HOWEVER WILL KEEP OUT OF
TAFS FOR THE TIME BEING DUE TO TIMING UNCERTAINTY. LOW CIGS AHEAD
OF THE COLD FRONT MAY ALSO DEVELOP. THE SREF ENSEMBLE SUGGESTS THE
POTENTIAL FOR MVFR CIGS NEAR THE END OF THE TAF PERIOD.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE FRIDAY THROUGH
EARLY SATURDAY AS A COLD FRONT CROSSES THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
532 AM EDT THU APR 21 2016
.SYNOPSIS...
THE FRONTAL BOUNDARY WILL SHIFT BACK TO THE NORTHEAST TODAY.
INCREASING MOISTURE AND A COLD FRONT WILL APPROACH FROM THE WEST
LATE THURSDAY THROUGH EARLY SATURDAY... BRINGING A CHANCE OF
SHOWERS AND A FEW THUNDERSTORMS...MAINLY DURING FRIDAY AFTERNOON
AND EVENING. DRY HIGH PRESSURE WILL BUILD BACK INTO THE REGION
LATE SATURDAY THROUGH TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
EARLY THIS MORNING...ONSHORE FLOW HAS ALLOWED LOW LEVEL MOISTURE
TO MOVE INLAND. LOW STRATUS WILL STRETCH FROM THE CENTRAL MIDLANDS
INTO THE PEE DEE REGION...SCATTERING OUT SHORTLY AFTER SUNRISE AS
DRIER AIR MIXES DOWN. MOISTURE INCREASES AND THE INSULATING STRATUS
WILL KEEP LOW TEMPERATURES IN THE NORTHERN AND CENTRAL MIDLANDS IN
THE UPPER 50S. ELSEWHERE EXPECT LOWS IN THE MID 50S.
TODAY...THE UPPER RIDGE WILL SHIFT OFF THE EAST COAST CREATING A
MORE S/SW FLOW REGIME AND MODERATE WARM ADVECTION ACROSS THE
REGION. THE STALLED FRONTAL BOUNDARY WILL LIFT TO THE NORTHEAST
OUT OF THE FORECAST AREA (FA) TODAY. UPPER LEVEL MOISTURE
ADVECTION AND HIGH CLOUDS WILL CONTINUE TO FLOW OVER THE REGION.
DESPITE PARTLY CLOUDY SKIES...LOCAL FORECAST TOOLS FAVOR THE
WARMER TEMPERATURE GUIDANCE DUE TO WARM ADVECTION AHEAD OF THE
COLD FRONT. EXPECT HIGHS IN THE LOW TO MID 80S.
HI RESOLUTION MODELS SHOW A SEA BREEZE BOUNDARY MOVING INLAND
INTO THE WESTERN FA LATE THIS AFTERNOON/EVENING. MID LEVEL DRY AIR
AND A SMALL CAPPING INVERSION WILL LIMIT CONVECTIVE DEVELOPMENT.
RECENT HRRR MODEL RUNS INDICATE SCATTERED TO ISOLATED SHOWERS
DEVELOPING ALONG THE COAST. WRF-ARW AND NMM MODELS ALSO KEEP
SHOWERS WEST OF THE AREA INCREASING CONFIDENCE IN A DRY FORECAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
CLOSED UPPER TROUGH WILL CONTINUE TRACKING EASTWARD TOWARDS THE
REGION OVERNIGHT. SURFACE WARM FRONT SHOULD BE NORTH OF THE CWA TO
START THE PERIOD...WITH THE MAIN COLD FRONT STILL MOVING EAST OF
THE MISSISSIPPI RIVER. THIS PUTS THE REGION IN THE WARM SECTOR OF
THE NEXT SYSTEM. LOW-LEVEL FLOW OVERNIGHT AND INTO FRIDAY WILL BE
OUT OF THE SOUTH TO SOUTHWEST...ALLOWING FOR AN INCREASE IN
MOISTURE. DO EXPECT THE EARLY PART OF TONIGHT TO BE DRY...THEN
SHOULD SEE AN INCREASE IN POPS FROM WEST TO EAST AFTER MIDNIGHT.
UPPER TROUGH MOVING THROUGH THE EASTERN CONUS ON FRIDAY WILL
DRIVE COLD FRONT TOWARD THE REGION THROUGH THE DAY. EXPECT MAINLY
SHOWERS EARLY IN THE DAY FRIDAY...WITH POTENTIAL FOR ISOLATED
THUNDERSTORMS IN THE AFTERNOON AS THE AIR MASS BECOMES WEAKLY TO
MODERATELY UNSTABLE. STRONGER CONVECTION MORE LIKELY WEST OF THE
REGION BACK IN NORTHWEST GEORGIA. DECREASING POPS THROUGH THE
NIGHT FRIDAY INTO SATURDAY MORNING AS FRONT MOVES THROUGH THE
AREA. DRY CONDITIONS ONCE AGAIN FOR SATURDAY. GUIDANCE TEMPERATURES
THROUGH THE PERIOD SEEM REASONABLE.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
DRY HIGH PRESSURE TO SETTLE INTO THE CWA FROM SATURDAY THROUGH
MONDAY. MOISTURE INCREASE MID WEEK AND ANOTHER FRONT POSSIBLY
MOVING SOUTH FROM THE NORTH MAY LEAD TO ISOLATED OR SCATTERED
AFTERNOON SHOWERS TUESDAY AND WEDNESDAY. TEMPERATURES SHOULD BE AT
OR ABOVE NORMAL THROUGH THE PERIOD.
&&
.AVIATION /09Z THURSDAY THROUGH MONDAY/...
ONSHORE FLOW HAS ALLOWED A PLUME OF LOW LEVEL MOISTURE TO
MOVE INLAND. THE HIGHEST MOISTURE CONTENT IS LOCATED FROM THE
CENTRAL MIDLANDS INTO THE PEE DEE REGION...WITH CAE/CUB AND OGB AT
THE PERIPHERY. MODELS SUGGEST MVFR/IFR CIGS AT CAE/CUB AND
OGB...MIXING OUT SHORTLY AFTER SUNRISE. EXPECT SOUTH WINDS FROM 5
TO 10 KNOTS THROUGH THE REST OF THE MORNING. A COLD FRONT
APPROACHING FROM THE WEST AND A TIGHTENING PRESSURE GRADIENT WILL
CREATE GUSTY CONDITIONS TODAY. BUFKIT FORECAST SOUNDINGS INDICATE
THE POTENTIAL FOR GUSTS UP TO 20 KNOTS DURING THE AFTERNOON HOURS.
LATE THIS EVENING...MODELS SUPPORT SHOWERS DEVELOPING AHEAD OF
THE APPROACHING COLD FRONT. THESE SHOWERS MAY REACH THE CENTRAL
MIDLANDS AND CSRA TAF SITES NEAR THE END OF THE TAF
PERIOD...HOWEVER WILL KEEP OUT OF TAFS FOR THE TIME BEING DUE TO
TIMING UNCERTAINTY. LOW CIGS AHEAD OF THE COLD FRONT MAY ALSO
DEVELOP. THE SREF ENSEMBLE SUGGESTS THE POTENTIAL FOR MVFR CIGS
NEAR THE END OF THE TAF PERIOD.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE THURSDAY NIGHT
THROUGH EARLY SATURDAY AS A COLD FRONT CROSSES THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
345 PM EDT THU APR 21 2016
.SYNOPSIS...
ISSUED AT 334 PM EDT THU APR 21 2016
SHOWERS AND A FEW THUNDERSTORMS WILL IMPACT THE REGION INTO
TONIGHT. SEVERE WEATHER IS NOT EXPECTED AT THIS TIME...BUT THE
STRONGEST STORMS COULD PRODUCE SMALL HAIL. RAIN CHANCES WILL
LINGER INTO FRIDAY MAINLY ALONG AND SOUTHEAST OF INTERSTATE 69.
LOWS TONIGHT IN THE MID 40S TO MID 50S.HIGHS ON FRIDAY WILL
GENERALLY BE IN THE UPPER 50S TO MIDDLE 60S AWAY FROM LAKE
MICHIGAN...WITH COOL ONSHORE FLOW LEADING TO HIGHS ONLY AROUND 50.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 334 PM EDT THU APR 21 2016
MAIN FOCUS ON CONVECTIVE DEVELOPMENT IN FAR WESTERN PARTS OF
FORECAST AREA AS WELL AS UPSTREAM NEAR THE UPPER LOW.
SOME POCKETS OF CLEARING/BREAKS HAVE OCCURRED ALLOWING TEMPERATURES
TO CLIMB INTO THE 60S ACROSS THE AREA AND MAKING A RUN AT 70 IN
WEST/SW LOCATIONS. NARROW PLUME OF HIGHER DEWPOINTS WAS NOW SHIFTING
ACROSS THE FORECAST AREA WITH SLIGHTLY LOWER READINGS UNDER THE
CLEARING AND WHERE CONVECTION WAS ATTEMPTING TO POP. ISOLATED
SHOWERS/STORMS HAVE BEEN DEVELOPING OVER THE LAST 30 TO 60
MINUTES...LIKELY CONTAINING AT LEAST SOME SMALL HAIL. ARC OF STORMS
ONGOING CLOSER TO THE UPPER LOW FROM WATERLOO IOWA TO MOLINE TO WEST
OF SPRINGFIELD IL. HRRR SUGGESTS THIS ACTIVITY WILL MOVE SLOWLY
NORTHEAST AND EXPAND MORE IN THE 22 TO 02Z WINDOW. HAVE KEPT HIGH
SCT TO NUMEROUS SHOWERS WITH MENTION OF THUNDER THROUGH THE EVENING.
EVE SHIFT MAY NEED TO ADJUST FOR TRENDS. TEMPERATURES WILL SLOWLY
FALL THIS EVENING AS AREA REMAINS IN THE WARM SECTOR...WITH SLOW
FALL OVERNIGHT AS THE COLD FRONT APPROACHES.
UPPER LOW WILL CONTINUE TO OPEN AND LINGER FRIDAY...ONLY DRIFTING
SLOWLY EAST INTO SOUTHERN OHIO BY 00Z SAT. GIVEN UPSTREAM TRENDS
UNDER THE UPPER LOW WITH SCATTERED SHOWERS AROUND...SEE NO REASON TO
MAKE ANY MAJOR CHANGES TO SE HALF OF THE AREA INTO MID AFTERNOON
WITH SCATTERED SHOWERS. WHILE NOT INTRODUCED...MAY NEED TO ADD
PASSING MENTION OF THUNDER AS SFC CAPE INCREASES TO AROUND 500 J/KG
AND MARGINAL LAPSE RATES.
&&
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 334 PM EDT THU APR 21 2016
A MORE PROGRESSIVE FLOW PATTERN WILL TAKE HOLD ON THE LOWER 48 THIS
WEEKEND INTO NEXT WEEK AS A SERIES OF WESTERN CONUS SHORTWAVES
EJECT/SHEAR EAST INTO MORE CONFLUENT/WNW FLOW OVER THE GREAT LAKES
REGION. LUCKILY THE WEEKEND WILL FEATURE DRY CONDITIONS WITH HIGH
PRESSURE IN CONTROL IN BETWEEN WAVES. SATURDAY THE COOLER/SUNNIER
DAY UNDER HIGH PRESSURE WITH WARM ADVECTION BEHIND SFC HIGH ALLOWING
HIGHS TO RETURN INTO THE 70S BY SUNDAY. FRONTAL SYSTEMS WITH THE
AFOREMENTIONED SHORTWAVES THEN BRING MORE UNSETTLED WX NEXT
WEEK...WITH LATEST GUIDANCE FAVORING MONDAY/MONDAY NIGHT AND
WEDNESDAY/WEDNESDAY NIGHT FOR HIGHER POPS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1202 PM EDT THU APR 21 2016
LOWER CLOUDS SHOULD QUICKLY LIFT/DISSIPATE AS DENSER OVERCAST
SHIFTS EAST. VIS SATELLITE SHOWS MORE OF A CELLULAR NATURE TO
CLOUD COVER WITH SCT TO BKN COVERAGE OF CU EXPECTED THROUGH THE
AFTERNOON. WHILE BOTH SITES ARE SEEING A GENERAL LULL
NOW...SHOWERS AND POSSIBLY A FEW THUNDERSTORMS WILL APPROACH/ENTER
THE AIRSPACE OF EACH AIRPORT MAINLY AFTER 20Z. WILL LIKELY LEAVE
ANY MENTION OF THUNDER OUT UNLESS CLEAR SIGNALS BEGIN TO SHOW IN
ABOUT AN HOUR WHEN THE TAFS ARE ISSUED. ACTIVITY WILL CONTINUE
INTO THIS EVENING UNTIL THE LOW AND MAIN COLD FRONT SHIFT EAST
LATE TONIGHT INTO FRIDAY. AT LEAST A PERIOD OF IFR CONDITIONS
STILL LOOKS LIKELY NEAR/AFTER 12Z AS THE UPPER LEVEL SYSTEM MOVES
OVERHEAD AND WILL BE SLOW TO LEAVE...ESPECIALLY AT KFWA.
&&
.MARINE...
WEBCAMS SHOWING A GOOD DEAL OF DENSE FOG IN THE NEARSHORE WATERS
WARRANTING ISSUANCE OF A MARINE DENSE FOG ADVISORY INTO THIS
EVENING UNTIL COLDER AIR STARTS TO MOVE IN. WILL ALSO HOIST SMALL
CRAFT ADVISORY FOR FRIDAY INTO FRIDAY EVENING FOR INCREASING NW
FLOW AND HIGHER WAVES.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...DENSE FOG ADVISORY UNTIL 2 AM EDT FRIDAY FOR LMZ043-046.
SMALL CRAFT ADVISORY FROM 8 AM FRIDAY TO 2 AM EDT SATURDAY FOR
LMZ043-046.
&&
$$
SYNOPSIS...FISHER
SHORT TERM...FISHER
LONG TERM...STEINWEDEL
AVIATION...FISHER
MARINE...FISHER
VISIT US AT WWW.WEATHER.GOV/IWX
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1219 PM EDT THU APR 21 2016
.SYNOPSIS...
ISSUED AT 1219 PM EDT THU APR 21 2016
SHOWERS AND A FEW THUNDERSTORMS WILL IMPACT THE REGION INTO
TONIGHT. SEVERE WEATHER IS NOT EXPECTED AT THIS TIME...BUT THE
STRONGEST STORMS COULD PRODUCE SMALL HAIL. HIGHS TODAY WILL REACH
THE UPPER 60S TO LOWER 70S...WARMEST CLOSER TO THE ILLINOIS STATE
LINE WHERE MORE SUNSHINE IS LIKELY TO OCCUR. RAIN CHANCES WILL
CONTINUE INTO TONIGHT WITH LOWS IN THE UPPER 40S TO LOW 50S.
&&
.UPDATE...
ISSUED AT 1202 PM EDT THU APR 21 2016
UPDATED GRIDS COMING SHORTLY TO LOWER POPS EAST FOR THE NEXT
SEVERAL HOURS AS MAIN AREA OF PRECIPITATION NOW MOVING AWAY WITH
MORE SHOWERY ACTIVITY EXPECTED INTO MID AFTERNOON.
VIS SAT SHOWING BREAKS OCCURRING IN DRY SLOT OF THE SYSTEM WITH
TEMPERATURES AND DEWPOINTS INCREASING (PUSHING NEAR 60 DEWPOINTS
NOW IN FAR SW). HRRR GENERALLY ON TRACK WITH STEADY RAINFALL
MOVING AWAY AND A FEW HOUR LULL WITH LITTLE MORE THAN SOME WIDELY
SCATTERED SHOWERS THROUGH ABOUT 20Z. AS PEAK HEATING
OCCURS...SHORTWAVE ARRIVES WITH DECREASING UPPER LEVEL
TEMPERATURES SHOULD SEE AN UPTICK IN COVERAGE AND INTENSITY WITH
WIDELY SCATTERED THUNDERSTORMS DEVELOPING. WIND FIELDS PRETTY
PATHETIC BUT LOW LEVEL LAPSE RATES INCREASE SUFFICIENTLY TO HELP
GET THINGS GOING...BUT CELLS LIKELY TO COLLAPSE FAIRLY QUICK.
ISOLATED STRONGER STORMS WOULD BE CAPABLE OF MARGINALLY SEVERE
HAIL IF THEY CAN PERSIST LONG ENOUGH AND IN THE DISSIPATION STAGE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 330 AM EDT THU APR 21 2016
INCREASING S/SW LLJ AHEAD OF APPROACHING CLOSED LOW SUPPORTING A
HEALTHY SWATH OF 295-300K SYSTEM RELATIVE ISENTROPIC ASCENT AND
MOISTURE ADVECTION EARLY THIS MORNING. DRY ANTECEDENT AIRMASS HAS
NOW BEEN LARGELY DISPLACED WITH 300K MIXING RATIOS CLIMBING TO
AROUND 7 G/KG AND PW VALUES APPROACHING 1.3 INCHES. LOW LEVEL
CONFLUENCE ZONE WILL MAKE SLOW EASTWARD PROGRESS LATER THIS MORNING
AS IT BECOMES ORIENTED PARALLEL TO MEAN FLOW ALOFT. CONTINUAL MOIST
ISENTROPIC ASCENT IN REGION OF GOOD UPPER DIVERGENCE AND AT LEAST
NEUTRAL STATIC STABILITY WILL MAINTAIN SCT/NUM SHOWERS FOR MUCH OF
THE DAY...ESPECIALLY IN OUR SOUTHEAST HALF. HI-RES MODELS SUGGEST
PARTIAL CLEARING IN OUR NORTHWEST HALF LATER THIS MORNING BUT THAT
WILL BE RELATIVELY SHORT LIVED GIVEN APPROACH OF VIGOROUS MIDLEVEL
CYCLONIC VORTICITY BULLSEYE BY THIS EVENING AND EXPECTATION FOR AT
LEAST SOME MARGINAL DIURNAL DESTABILIZATION. SOME THUNDERSTORMS
EXPECTED THIS AFTERNOON AND EVENING BUT INSTABILITY VALUES APPEAR
MEAGER AT THIS POINT. 00Z NAM SUGGESTS AROUND 1000 J/KG SBCAPE IN
OUR WEST THIS AFTERNOON BUT THIS IS LIKELY A BIT OVERDONE AND PREFER
MORE SUBDUED GFS VALUES WITH AROUND 500 J/KG. GIVEN POOR MIDLEVEL
LAPSE RATES AND LACK OF ANY SUBSTANTIVE LOW LEVEL FLOW THIS
AFTERNOON...SEVERE CHANCES APPEAR VERY LOW...ESPECIALLY EAST OF US-
31. BETTER LAPSE RATES BY LATE EVENING AS MIDLEVEL COLD POOL MOVES
OVERHEAD BUT ANY CONVECTION WILL LIKELY BE ELEVATED BY THEN GIVEN
LOSS OF DIURNAL HEATING. A FEW STRONGER STORMS MAY CLIP OUR FAR
WESTERN COUNTIES UNDER/NEAR SWODY1 MARGINAL RISK THIS EVENING BUT
AGAIN...CHANCES FOR EVEN THAT APPEAR LOW AT THIS POINT. REGARDLESS
OF INSTABILITY...CVA BULLSEYE WILL BRING A SECONDARY ROUND OF
SHOWERS TO THE AREA LATE THIS EVENING AND HAVE MAINTAINED LIKELY
POPS FOR MOST OF THE AREA DURING THAT TIME. HIGHS TODAY AROUND 70F
WITH LOWS TONIGHT GENERALLY IN THE UPPER 40S TO LOW 50S.
&&
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 330 AM EDT THU APR 21 2016
MORE OF A PROGRESSIVE PATTERN IN THE LONG TERM PERIOD. UPPER LOW
THAT HAS PLAGUED THE CENTRAL CONUS WILL FINALLY BE OPENING UP AND
EXITING THE AREA AT THE START OF THIS PERIOD. MODELS HAVE SLOWED
THIS FEATURE AND MOISTURE NOW LINGERS FRIDAY OVER EASTERN THIRD OF
FORECAST AREA INTO THE AFTERNOON HOURS. PRETTY DECENT MODEL
AGREEMENT AND WITH MAIN TROUGH AXIS OVER TOP FRIDAY MORNING HAVE
RAISED POPS IN THE EAST TO HIGH CHANCE. MOST GUIDANCE MUCH HIGHER
AND HAVE TRENDED GRIDS UPWARD.
ANOTHER NICE WEEKEND SHAPING UP. CLOUDS TO SLOWLY CLEAR LATER FRIDAY
WITH MOSTLY CLEAR CONDITIONS FRIDAY NIGHT INTO SATURDAY AS HIGH
PRESSURE MOVES BY TO OUR NORTH. A FEW MODELS STILL WANT TO BRING
SOME LIGHT PCPN INTO THE FAR NORTH SUNDAY ON SOUTHERN FRINGE OF
DEVELOPING WARM FRONT. MAINTAINED A SLIGHT CHANCE POP BUT BEST
MOISTURE AND FORCING NORTH OF THE AREA AND MORE THAN LIKELY WILL
ONLY SEE INCREASED CLOUDS AND MAYBE A STRAY SHOWER IN AFTERNOON.
BETTER CHANCES FOR PCPN LOOK TO BE ON MONDAY AS MID LEVEL HEIGHTS
FALL WITH APPROACH OF SHORT WAVE AND SFC BOUNDARY SINKS FURTHER
SOUTH OVER THE AREA. AREA OF LOW PRESSURE TO TRACK ALONG BOUNDARY
ENHANCING ASCENT AND PCPN COVERAGE. DRYING LIKELY ON TUESDAY WITH
ANOTHER HIGH SLIDING ACROSS THE LAKES REGION. RETURN FLOW QUICKLY
DEVELOPS WITH PCPN CHANCES INCREASING AGAIN WEDNESDAY. MODEL
DISPARITY IN THESE LATER PERIODS WITH DEGREE OF WARM ADVECTION AND
SFC TEMPS. GFS MUCH WARMER THAN ECMWF AND OTHER MEDIUM RANGE
GUIDANCE. SUPERBLEND REMAINS IN THE MIDDLE TO COOLER SIDE AND
SIMILAR TO WPC GUIDANCE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1202 PM EDT THU APR 21 2016
LOWER CLOUDS SHOULD QUICKLY LIFT/DISSIPATE AS DENSER OVERCAST
SHIFTS EAST. VIS SATELLITE SHOWS MORE OF A CELLULAR NATURE TO
CLOUD COVER WITH SCT TO BKN COVERAGE OF CU EXPECTED THROUGH THE
AFTERNOON. WHILE BOTH SITES ARE SEEING A GENERAL LULL
NOW...SHOWERS AND POSSIBLY A FEW THUNDERSTORMS WILL APPROACH/ENTER
THE AIRSPACE OF EACH AIRPORT MAINLY AFTER 20Z. WILL LIKELY LEAVE
ANY MENTION OF THUNDER OUT UNLESS CLEAR SIGNALS BEGIN TO SHOW IN
ABOUT AN HOUR WHEN THE TAFS ARE ISSUED. ACTIVITY WILL CONTINUE
INTO THIS EVENING UNTIL THE LOW AND MAIN COLD FRONT SHIFT EAST
LATE TONIGHT INTO FRIDAY. AT LEAST A PERIOD OF IFR CONDITIONS
STILL LOOKS LIKELY NEAR/AFTER 12Z AS THE UPPER LEVEL SYSTEM MOVES
OVERHEAD AND WILL BE SLOW TO LEAVE...ESPECIALLY AT KFWA.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
UPDATE...FISHER
SYNOPSIS...AGD
SHORT TERM...AGD
LONG TERM...LASHLEY
AVIATION...FISHER
VISIT US AT WWW.WEATHER.GOV/IWX
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
111 PM CDT THU APR 21 2016
.AVIATION...
MAIN FORECAST ISSUES ARE TIMING OF POSSIBLE TSRA LATER THIS
AFTERNOON AND EVENING AND POSSIBILITY OF LOW STRATUS AND PATCHY
FOG WHEN SHRA/TSRA DIMINISH OVERNIGHT INTO EARLY FRIDAY MORNING.
FOR THE TSRA...INCLUDED A 3 HOUR TEMPO GROUP STARTING 21-23Z THIS
AFTERNOON WHEN POTENTIAL APPEARS HIGHEST...AND LOWER IFR/LIFR
CONDITIONS AT A FEW AIRPORTS AFTER 09Z TONIGHT. 22/TD
&&
.PREV DISCUSSION... /ISSUED 346 AM CDT THU APR 21 2016/
SHORT TERM...
FRONTAL ZONE EXTENDING ROUGHLY ALONG THE MISSISSIPPI VALLEY
APPEARS TO BE WEAKENING IN FAVOR OF BETTER UPPER DYNAMICS AND
SUPPORT FARTHER WEST IN NORTH TEXAS. THE LEADING FRONT MAY SERVE
AS A LOCAL FOCUS FOR CONVECTION WITH SOME HEATING BUT COMPLEX OF
STORMS MOVING ALONG THE COAST IN WHAT APPEARS TO BE A MINOR MCV
MAY IMPEDE INFLOW AS WELL AS PROVIDE THICK CANOPY OVER THE AREA
THIS MORNING. LATEST HRRR MODEL RUN DOES SHOW THIS SCENARIO WITH
ONLY MODEST COVERAGE OVER LAND AREAS AND MORE ROBUST CONVECTION
OVER THE NEAR SHORE WATERS. WILL INDICATE 50-60 PERCENT RAIN
CHANCES TODAY BUT MCV PROGRESSION WILL MAINTAIN UNCERTAINTY ON QPF
EXPECTATIONS. WPC HAS OUTLOOKED A SLIGHT RISK FOR FLASH FLOODING
THAT MAY POTENTIALLY MATERIALIZE LATER TODAY. BETTER FRONTAL
FORCING IS THEN EXPECTED OVERNIGHT INTO FRIDAY MORNING BUT ARE IN
CONSENSUS IN SHOWING SOME BRIEF STALLING ALONG THE COAST UNTIL THE
DENSER AIR MASS ARRIVES LATE FRIDAY INTO EARLY SATURDAY. RAIN
CHANCES WILL BE MAINTAINED THROUGH FRIDAY NIGHT WITH CONSIDERABLE
IMPROVEMENT EXPECTED FOR THE WEEKEND. 24/RR
LONG TERM...
SURFACE HIGH PRESSURE TO PROVIDE FAIR WEATHER THROUGH EARLY
MONDAY. A FRONTAL ZONE IN THE NORTHERN STATES WILL USHER A TROWAL
ALONG THE LOWER MISSISSIPPI VALLEY TO AID IN FOCUSING RAINFALL
ONCE AGAIN OVERNIGHT MONDAY. SUPPORT FOR CONVECTION WILL BE
LIMITED AND WANING UPON ARRIVAL AS HIGH PRESSURE BUILDS FROM THE
EAST TO BRING ABOVE NORMAL TEMPERATURES AND LOWER RAIN CHANCES
LATTER PART OF THE FORECAST PERIOD. 24/RR
AVIATION...
EXPECT VFR CONDITIONS TO PREVAIL TODAY OUTSIDE OF SHOWERS AND
STORMS. A SYSTEM WILL BE MOVING INTO THE AREA BRINGING A CHANCE OF
SHOWERS AND THUNDERSTORMS TODAY. THE BEST CHANCE FOR RAIN WILL BE
THIS AFTERNOON ACROSS THE AREA. EXPECT THE RAIN CHANCES TO REMAIN
HIGH INTO THE EVENING AND OVERNIGHT HOURS. WILL HAVE TO MAKE SOME
CHANGES WITH THE NEXT ISSUANCE AND WILL HAVE MONITOR THE
SITUATION THROUGHOUT THE DAY. 13/MH
MARINE...
EXPECT GENERALLY LIGHT EAST TO SOUTHEAST WINDS. A COLD FRONT IS
STILL EXPECTED TO MOVE THROUGH THE COASTAL WATERS ON FRIDAY. EXPECT
OFFSHORE WINDS LATE FRIDAY AND SATURDAY BEFORE QUICKLY VEERING BACK
TO ONSHORE SUNDAY AS HIGH PRESSURE MOVES OVER THE EASTERN GULF AND
ALONG THE ATLANTIC COAST. 13/MH
DECISION SUPPORT...
DSS CODE....BLUE.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...MINOR RIVER FLOODING.
DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED WATCH/WARNING/ADVISORY
ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED = FULL ENGAGEMENT FOR MODERATE RISK SVR AND/OR DIRECT
TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE.
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 77 61 79 58 / 60 60 40 10
BTR 80 63 81 59 / 70 60 40 10
ASD 78 65 80 61 / 50 50 40 10
MSY 79 66 79 64 / 50 40 40 20
GPT 77 66 78 63 / 50 40 40 20
PQL 77 64 78 61 / 40 30 40 20
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
102 PM CDT THU APR 21 2016
.DISCUSSION...
21/18Z TAF ISSUANCE.
&&
.AVIATION...
YET ANOTHER COMPLEX OF SHRA/TSRA CROSSING THE AREA
TODAY...CURRENTLY EXTENDING FM THE LAKES REGION SOUTH TOWARD
BEAUMONT. TIMED TEMPO GROUPS AT EACH SITE BASED ON CURRENT TRENDS
AND HI-RES GUIDANCE...WITH THE LINE NOW APPROACHING BPT...REACHING
AEX/LCH 20-24Z...AND LFT/ARA 22-01Z. WIND GUSTS TO NEAR 40 KT...VERY
HEAVY RAINFALL AND FREQUENT LIGHTNING WILL ACCOMPANY THE STRONGEST
STORMS. OTHERWISE...VFR CONDITIONS PREVAIL OUTSIDE OF
CONVECTION WITH SLY WINDS 5-10 KT. EXPECT CIGS TO LOWER THIS
EVENING TO MVFR WITH WINDS BCMG LT. PATCHY FOG WILL BE POSSIBLE
OVERNIGHT...REDUCING VSBYS TO MVFR BETWEEN 08-13Z. EXPECT
IMPROVING CONDITIONS FRIDAY MORNING...WITH DRIER AIR BEGINNING TO
MOVE INTO THE AREA.
24
&&
.PREV DISCUSSION... /ISSUED 956 AM CDT THU APR 21 2016/
UPDATE...
SATELLITE BEGINNING TO SHOW ENHANCED AREAS OF NEW CONVECTION
DEVELOPING ACROSS SOUTHEAST TEXAS AND THUS WE START ANEW AGAIN
WITH THE RAIN...IT`S COMING. WE HAVE A CONSISTENT MESSAGE...POPS
REMAIN HIGH ACROSS THE AREA...A FLASH FLOOD WATCH IS IN EFFECT
TODAY..WE HAVE A SATURATED GROUND ...AND FLOODING RAINS ARE
LIKELY TO OCCUR. DO NOT DRIVE INTO AREAS WHERE WATER COVERS THE
ROADS...TURN AROUND DON`T DROWN. DO NOT GO NEAR CREEKS...DITCHES
OR DRIVE INTO LOW AREAS LIKE UNDERPASSES...THESE ARE REALLY
DANGEROUS PLACES TO BE IN FLASH FLOODING RAINS.
DEWPOINTS HAVE RECOVERED ACROSS SOUTHEAST TEXAS AND HRRR INDICATES
THIS WILL BE A FAVORABLE PLACE FOR FLOODING RAINS TO DEVELOP AND
MOVE EAST ACROSS THE I-10 CORRIDOR AREA. WPC INDICATING 2 TO 3
INCH RAINS COULD DEVELOP FAIRLY QUICKLY ONCE THE STORMS
BEGIN...THEREFORE ...FLASH FLOOD WARNINGS ARE LIKELY IN THE NEXT
FEW HOURS. STAY ABREAST OF THE WEATHER FOLKS.
NO CHANGES TO FORECAST...WILL LET IT RIDE.
06
PREV DISCUSSION... /ISSUED 648 AM CDT THU APR 21 2016/
AVIATION...SHOWER AND THUNDERSTORM ACTIVITY OVER THE SOUTHERN
PORTION OF THE AREA EARLIER HAS NOW SETTLED SOUTH INTO THE NEAR
COASTAL WATERS AND WEAKENED. REDEVELOPMENT IS EXPECTED LATE
MORNING AND THROUGH THE AFTERNOON OVER THE AREA AS ANOTHER WEATHER
DISTURBANCE APPROACHES FROM EAST TEXAS AND MOVES ACROSS THE
REGION. EARLY MORNING VISIBILITY RESTRICTIONS ALONG WITH IFR
STRATUS CEILINGS AT BPT AND AEX WILL BE LIFTING SHORTLY. MVFR INTO
VFR CEILINGS WILL GENERALLY PREVAIL AT ALL TERMINALS THROUGH THE
REMAINDER OF THE DAY.
23
PREV DISCUSSION... /ISSUED 423 AM CDT THU APR 21 2016/
DISCUSSION...
BUSY WEATHER PATTERN OVER THE REGION AS THE DISTURBANCE YESTERDAY
IS ANCHORED ALONG THE SOUTHERN LOUISIANA COAST THIS MORNING. THIS
SYSTEM IS EXPECTED TO MOVE EASTWARD THROUGH THE DAY. MEANWHILE
ANOTHER UPPER LEVEL DISTURBANCE IS MOVING INTO CENTRAL TEXAS THIS
MORNING AND LOOKS TO MAKE SOUTHEAST TEXAS DURING THE LATE MORNING/
EARLY AFTERNOON HOURS THEN MOVING INTO SOUTHERN LOUISIANA. THE
RECENT RAINS OVER THE LAST SEVERAL DAYS HAS PRODUCED RAINFALL
TOTAL OVER SIX INCHES IN SOME LOCATIONS AND TWO TO THREE INCHES
IS COMMON ACROSS MOST OF THE REGION. AS A RESULT... THE GROUND IS
COMPLETELY SATURATED... RAINS TODAY ARE EXPECTED TO FLOW INTO LOW
LYING AREAS...STREAMS AND BAYOUS. A FLASH FLOOD WATCH WILL
CONTINUE THROUGH THE MORNING INTO THE AFTERNOON HOURS.
ABOUT THE ONLY GOOD NEWS IS BEHIND THIS NEXT DISTURBANCE WILL BE A
SLOW MOVING COOL FRONT THAT WILL FINALLY BRING THE AREA SOME REST
FROM THE RECENT RAINS. FRIDAY AND INTO THE WEEKEND LOOKS TO BE
DRY. THE DOWN SIDE IS MORE RAINS ARE EXPECTED LATE SUNDAY INTO
MONDAY AS ANOTHER UPPER LEVEL DISTURBANCE MOVES INTO THE REGION.
19
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 78 62 80 59 / 70 40 20 10
LCH 78 66 81 63 / 70 40 20 10
LFT 80 66 81 62 / 70 40 30 10
BPT 79 64 82 63 / 70 30 20 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...FLASH FLOOD WATCH UNTIL 6 PM CDT THIS EVENING FOR LAZ027>033-
041>045-052>055-073-074.
TX...FLASH FLOOD WATCH UNTIL 6 PM CDT THIS EVENING FOR TXZ180-201-215-
216-259>262.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
956 AM CDT THU APR 21 2016
.UPDATE...
SATELLITE BEGINNING TO SHOW ENHANCED AREAS OF NEW CONVECTION
DEVELOPING ACROSS SOUTHEAST TEXAS AND THUS WE START ANEW AGAIN
WITH THE RAIN...IT`S COMING. WE HAVE A CONSISTENT MESSAGE...POPS
REMAIN HIGH ACROSS THE AREA...A FLASH FLOOD WATCH IS IN EFFECT
TODAY..WE HAVE A SATURATED GROUND ...AND FLOODING RAINS ARE
LIKELY TO OCCUR. DO NOT DRIVE INTO AREAS WHERE WATER COVERS THE
ROADS...TURN AROUND DON`T DROWN. DO NOT GO NEAR CREEKS...DITCHES
OR DRIVE INTO LOW AREAS LIKE UNDERPASSES...THESE ARE REALLY
DANGEROUS PLACES TO BE IN FLASH FLOODING RAINS.
DEWPOINTS HAVE RECOVERED ACROSS SOUTHEAST TEXAS AND HRRR INDICATES
THIS WILL BE A FAVORABLE PLACE FOR FLOODING RAINS TO DEVELOP AND
MOVE EAST ACROSS THE I-10 CORRIDOR AREA. WPC INDICATING 2 TO 3
INCH RAINS COULD DEVELOP FAIRLY QUICKLY ONCE THE STORMS
BEGIN...THEREFORE ...FLASH FLOOD WARNINGS ARE LIKELY IN THE NEXT
FEW HOURS. STAY ABREAST OF THE WEATHER FOLKS.
NO CHANGES TO FORECAST...WILL LET IT RIDE.
&&
.PREV DISCUSSION... /ISSUED 648 AM CDT THU APR 21 2016/
AVIATION...SHOWER AND THUNDERSTORM ACTIVITY OVER THE SOUTHERN
PORTION OF THE AREA EARLIER HAS NOW SETTLED SOUTH INTO THE NEAR
COASTAL WATERS AND WEAKENED. REDEVELOPMENT IS EXPECTED LATE
MORNING AND THROUGH THE AFTERNOON OVER THE AREA AS ANOTHER WEATHER
DISTURBANCE APPROACHES FROM EAST TEXAS AND MOVES ACROSS THE
REGION. EARLY MORNING VISIBILITY RESTRICTIONS ALONG WITH IFR
STRATUS CEILINGS AT BPT AND AEX WILL BE LIFTING SHORTLY. MVFR INTO
VFR CEILINGS WILL GENERALLY PREVAIL AT ALL TERMINALS THROUGH THE
REMAINDER OF THE DAY.
PREV DISCUSSION... /ISSUED 423 AM CDT THU APR 21 2016/
DISCUSSION...
BUSY WEATHER PATTERN OVER THE REGION AS THE DISTURBANCE YESTERDAY
IS ANCHORED ALONG THE SOUTHERN LOUISIANA COAST THIS MORNING. THIS
SYSTEM IS EXPECTED TO MOVE EASTWARD THROUGH THE DAY. MEANWHILE
ANOTHER UPPER LEVEL DISTURBANCE IS MOVING INTO CENTRAL TEXAS THIS
MORNING AND LOOKS TO MAKE SOUTHEAST TEXAS DURING THE LATE MORNING/
EARLY AFTERNOON HOURS THEN MOVING INTO SOUTHERN LOUISIANA. THE
RECENT RAINS OVER THE LAST SEVERAL DAYS HAS PRODUCED RAINFALL
TOTAL OVER SIX INCHES IN SOME LOCATIONS AND TWO TO THREE INCHES
IS COMMON ACROSS MOST OF THE REGION. AS A RESULT... THE GROUND IS
COMPLETELY SATURATED... RAINS TODAY ARE EXPECTED TO FLOW INTO LOW
LYING AREAS...STREAMS AND BAYOUS. A FLASH FLOOD WATCH WILL
CONTINUE THROUGH THE MORNING INTO THE AFTERNOON HOURS.
ABOUT THE ONLY GOOD NEWS IS BEHIND THIS NEXT DISTURBANCE WILL BE A
SLOW MOVING COOL FRONT THAT WILL FINALLY BRING THE AREA SOME REST
FROM THE RECENT RAINS. FRIDAY AND INTO THE WEEKEND LOOKS TO BE
DRY. THE DOWN SIDE IS MORE RAINS ARE EXPECTED LATE SUNDAY INTO
MONDAY AS ANOTHER UPPER LEVEL DISTURBANCE MOVES INTO THE REGION.
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 78 62 80 59 / 70 40 20 10
LCH 78 66 81 63 / 70 40 20 10
LFT 80 66 81 62 / 70 40 30 10
BPT 79 64 82 63 / 70 30 20 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...FLASH FLOOD WATCH UNTIL 6 PM CDT THIS EVENING FOR LAZ027>033-
041>045-052>055-073-074.
TX...FLASH FLOOD WATCH UNTIL 6 PM CDT THIS EVENING FOR TXZ180-201-215-
216-259>262.
GM...NONE.
&&
$$
PUBLIC...06
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
346 AM CDT THU APR 21 2016
.SHORT TERM...
FRONTAL ZONE EXTENDING ROUGHLY ALONG THE MISSISSIPPI VALLEY
APPEARS TO BE WEAKENING IN FAVOR OF BETTER UPPER DYNAMICS AND
SUPPORT FARTHER WEST IN NORTH TEXAS. THE LEADING FRONT MAY SERVE
AS A LOCAL FOCUS FOR CONVECTION WITH SOME HEATING BUT COMPLEX OF
STORMS MOVING ALONG THE COAST IN WHAT APPEARS TO BE A MINOR MCV
MAY IMPEDE INFLOW AS WELL AS PROVIDE THICK CANOPY OVER THE AREA
THIS MORNING. LATEST HRRR MODEL RUN DOES SHOW THIS SCENARIO WITH
ONLY MODEST COVERAGE OVER LAND AREAS AND MORE ROBUST CONVECTION
OVER THE NEAR SHORE WATERS. WILL INDICATE 50-60 PERCENT RAIN
CHANCES TODAY BUT MCV PROGRESSION WILL MAINTAIN UNCERTAINTY ON QPF
EXPECTATIONS. WPC HAS OUTLOOKED A SLIGHT RISK FOR FLASH FLOODING
THAT MAY POTENTIALLY MATERIALIZE LATER TODAY. BETTER FRONTAL
FORCING IS THEN EXPECTED OVERNIGHT INTO FRIDAY MORNING BUT ARE IN
CONSENSUS IN SHOWING SOME BRIEF STALLING ALONG THE COAST UNTIL THE
DENSER AIR MASS ARRIVES LATE FRIDAY INTO EAERLY SATURDAY. RAIN
CHANCES WILL BE MAINTAINED THROUGH FRIDAY NIGHT WITH CONSIDERABLE
IMPROVEMENT EXPECTED FOR THE WEEKEND. 24/RR
.LONG TERM...
SURFACE HIGH PRESSURE TO PROVIDE FAIR WEATHER THROUGH EARLY
MONDAY. A FRONTAL ZONE IN THE NORTHERN STATES WILL USHER A TROWAL
ALONG THE LOWER MISSISSIPPI VALLEY TO AID IN FOCUSING RAINFALL
ONCE AGAIN OVERNIGHT MONDAY. SUPPORT FOR CONVECTION WILL BE
LIMITED AND WANING UPON ARRIVAL AS HIGH PRESSURE BUILDS FROM THE
EAST TO BRING ABOVE NORMAL TEMPERATURES AND LOWER RAIN CHANCES
LATTER PART OF THE FORECAST PERIOD. 24/RR
&&
.AVIATION...
EXPECT VFR CONDITIONS TO PREVAIL TODAY OUTSIDE OF SHOWERS AND
STORMS. A SYSTEM WILL BE MOVING INTO THE AREA BRINGING A CHANCE OF
SHOWERS AND THUNDERSTORMS TODAY. THE BEST CHANCE FOR RAIN WILL BE
THIS AFTERNOON ACROSS THE AREA. EXPECT THE RAIN CHANCES TO REMAIN
HIGH INTO THE EVENING AND OVERNIGHT HOURS. WILL HAVE TO MAKE SOME
CHANGES WITH THE NEXT ISSUANCE AND WILL HAVE MONITOR THE
SITUATION THROUGHOUT THE DAY. 13/MH
&&
.MARINE...
EXPECT GENERALLY LIGHT EAST TO SOUTHEAST WINDS. A COLD FRONT IS
STILL EXPECTED TO MOVE THROUGH THE COASTAL WATERS ON FRIDAY. EXPECT
OFFSHORE WINDS LATE FRIDAY AND SATURDAY BEFORE QUICKLY VEERING BACK
TO ONSHORE SUNDAY AS HIGH PRESSURE MOVES OVER THE EASTERN GULF AND
ALONG THE ATLANTIC COAST. 13/MH
&&
.DECISION SUPPORT...
DSS CODE....BLUE.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...MINOR RIVER FLOODING.
DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED WATCH/WARNING/ADVISORY
ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED = FULL ENGAGEMENT FOR MODERATE RISK SVR AND/OR DIRECT
TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE.
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 77 61 79 58 / 60 60 40 10
BTR 80 63 81 59 / 70 60 40 10
ASD 78 65 80 61 / 50 50 40 10
MSY 79 66 79 64 / 50 40 40 20
GPT 77 66 78 63 / 50 40 40 20
PQL 77 64 78 61 / 40 30 40 20
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.
&&
$$
24/RR
13/MH
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
1013 PM EDT FRI APR 22 2016
.SYNOPSIS...
A COLD FRONT PUSHES ACROSS THE AREA AND OFF THE COAST EARLY
SATURDAY MORNING. AN UPPER LEVEL DISTURBANCE WILL DROP THROUGH THE
REGION SATURDAY. HIGH PRESSURE RETURNS SATURDAY NIGHT THROUGH
MONDAY. THE NEXT COLD FRONT DROPS ACROSS THE REGION TUESDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
FORECAST UPDATED BASED ON LATEST RADAR TRENDS AND HIRES MODEL
GUIDANCE...MAIN CHANGE WAS TO HOLD ONTO LIKELY POPS FOR MUCH OF
THE AREA THRU THE ERLY OVRNGT HRS.
PREVIOUS DISCUSSION...
LATEST GOES WATER VAPOR IMAGERY DEPICTS THE UPPER CLOSED LOW OVER
THE OH VALLEY THIS AFTERNOON WITH A PLUME OF MOISTURE EXTENDING
ALONG THE SOUTHEAST COASTAL PLAIN INTO THE LOCAL AREA. THE COLD
FRONT STILL LAGS OVER CENTRAL OH/KY/TN. LATEST REGIONAL RADAR
DEPICTS BROAD AREA OF SHOWERS EAST OF INTERSTATE 95 WITH SCATTERED
SHOWERS WEST. ONLY LINGER THUNDER REMAINS OVER THE ERN SHORE NEAR
THE COAST. THE NEXT BATCH OF SHOWERS AND EMBEDDED THUNDER IS LOCATED
OVER CENTRAL AND EASTERN NC. HI-RES GUIDANCE LIFTS THE SHOWERS INTO
THE SE HALF OF THE LOCAL AREA THRU THE REST OF THE AFTERNOON.
ANOTHER AREA OF SHOWERS ASSOCIATED WITH THE NEXT PLUME OF MOISTURE
AND THE UPPER LOW PUSHES INTO THE PIEDMONT...BUT IS EXPECTED TO
REMAIN SCATTERED. SHOWERS HAVE LIMITED WHAT LITTLE INSTABILITY THERE
WAS...BUT TEMPS REMAIN IN THE MID 70S ACROSS NE NC. RAP GUIDANCE
INDICATES MLCAPE VALUES AROUND 500 J/KG. WILL KEEP MENTION OF CHANCE
THUNDER WITH LIKELY POPS. PRECIP BEGINS TO TAPER OFF INLAND THIS
EVENING AS THE COLD FRONT APPROACHES. EXPECT ONLY SCATTERED SHOWERS
ALONG THE FRONT AS IT REACHES THE AREA AROUND MIDNIGHT. YET ANOTHER
WAVE CURRENTLY ASSOCIATED WITH PRECIP OVER GA/SC IS PROGGED TO LIFT
INTO THE SE LOCAL AREA OVERNIGHT. THE ADDED LIFT FROM THE
APPROACHING UPPER LOW AND COLD FRONT WILL ENHANCE PRECIP ACROSS THE
SE VA/NE NC AGAIN. LIKELY POPS PREVAIL ALONG THE COAST THRU THE
OVERNIGHT.
MILD TEMPS EXPECTED OVERNIGHT WITH CLOUDS/PRECIP. LOWS GENERALLY IN
THE MID/UPPER 50S INLAND TO LOW 60S SOUTHEAST.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
SFC FRONT PUSHES OFFSHORE SAT MORNING AS THE UPPER LEVEL FRONT LAGS
BEHIND. SHORTWAVE DROPS OVER THE LOCAL AREA SAT AFTERNOON...PUSHING
OFFSHORE SAT EVENING. PWATS DROP TO AOB 1 INCH SAT...BUT CROSS
SECTIONS AND BUFR SOUNDINGS INDICATE REMNANT MID LEVEL MOISTURE.
ADDED FORCING FOR ASCENT AND SHARPENING LAPSE RATES AS COLDER AIR
ALOFT ADVECTS INTO THE REGION WILL RESULT IN ONGOING CHANCES FOR
SHOWERS SAT MORNING. THE BEST CHANCES WILL BE ALONG THE COAST...BUT
STILL EXPECT LIGHT SHOWERS INLAND. MOISTURE REMAINS RATHER
SHALLOW...SO EXPECT ONLY A FEW TENTHS OF AN INCH AT BEST. NLY WINDS
INCREASE TO 10 TO 15 MPH SAT AFTERNOON WITH CLEARING SKIES NW TO SE
THRU THE AFTERNOON. MODEST CAA (AT BEST) AND MIXING WILL PUSH TEMPS
BACK INTO THE LOW/MID 70S (COOLER ALONG THE COAST).
UPPER/SFC HIGH PRESSURE BUILDS OVER THE REGION SAT NIGHT...LOCATING
OVER THE MID ATLANTIC REGION SUN. EXPECT A CLEAR/SUNNY SKY WITH
SEASONABLE TEMPERATURES. LOWS SAT NIGHT IN THE MID/UPPER 40S TO LOW
50S AND HIGHS SUN IN THE LOW 70S INLAND AND MID/UPPER 60S NEAR THE
COAST. LIGHT ONSHORE FLOW WILL RESULT IN TEMPS IN THE UPPER 50S
ALONG THE IMMEDIATE COAST. THE HIGH PUSHES OFFSHORE SUN NIGHT WITH
SLY/RETURN FLOW FORECAST INTO MONDAY. LOWS SUN NIGHT IN THE UPPER
40S TO LOW 50S. SUNNY MONDAY AND WARM AS H85 TEMPS WARM TO AROUND
12C (+1 STD DEV). THICKNESSES YIELD TEMPS IN THE LOW/MID 80S UNDER A
SUNNY SKY. HIGH CLOUDS MAY INCREASE LATE MON AS THE NEXT COLD FRONT
APPROACHES THE REGION FROM THE NW.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
HIGH PRESSURE SETTLES OFF THE SOUTHEAST COAST BY TUESDAY.
MEANWHILE...A SHORTWAVE TROUGH AND AN ASSOCIATED COLD FRONT APPROACH
FROM THE NW BY TUESDAY AFTN. TUESDAY CONTINUES TO TREND TOWARD BEING
A VERY WARM DAY WITH DEEP LAYER WSW FLOW ASSOCIATED WITH A BREAKING
DOWN UPPER RIDGE OVER THE E-CENTRAL/SERN CONUS. MODEL CONSENSUS
GENERALLY SUPPORTS 850MB TEMPERATURES OF 12-15C...WHICH WITH FULL
MIXING AND DOWNSLOPING SHOULD EASILY PUSH HIGHS TO THE LOW/MID 80S W
OF THE BAY...WITH UPPER 70S FOR THE ERN SHORE...AFTER MORNING LOWS
IN THE UPPER 50S TO LOW 60S. SKY COVER SHOULD GENERALLY BE MOSTLY
CLEAR MONDAY NIGHT...AND BECOME PARTLY SUNNY BY TUESDAY. THE TROUGH
AND COLD FRONT SWING THROUGH THE AREA TUESDAY AFTN INTO TUESDAY
NIGHT. THE MAIN FORCING ASSOCIATED WITH THE MID/UPPER SHORTWAVE
TROUGH GENERALLY PASSES N OF THE LOCAL AREA...AND DEEP LAYER RH
DIMINISHES AS THE FEATURE PASSES OVER THE LOCAL AREA SO FORECAST
POPS FOR SHOWERS/TSTMS REMAIN ~20%...WITH A STRIP OF 30% ACROSS THE
FAR N...AND 40% FOR THE LOWER MD ERN SHORE. HIGH PRESSURE BUILDS IN
FROM THE N WEDNESDAY...AND SLIDES OFFSHORE THURSDAY. HIGHS WEDNESDAY
SHOULD DROP BACK TO THE MID/UPPER 60S NE...TO THE MID/UPPER 70S
FARTHER INLAND...AND THEN TREND UPWARD THURSDAY INTO THE MID 70S TO
LOW 80S AS THE HIGH SLIDES OFFSHORE. LOWS SHOULD GENERALLY BE IN THE
50S. A WEAK COLD FRONT SWINGS ACROSS THE AREA LATER IN THE WEEK WITH
ONLY A MINIMAL CHC FOR SHOWERS/TSTMS.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
PRECIPITATION WIDESPREAD ACROSS THE AREA IN THE WARM MOIST
SOUTHERLY FLOW AHEAD OF A COLD FRONT THAT IS MOVING THROUGH
WVA AS OF 01Z.
WAVE MOVING THROUGH THE SE WILL GET PULLED NORTHWARD AHEAD OF THE
NORTHERN STREAM TROUGH TONIGHT AND WILL KEEP THE THREAT FOR
RAIN/STORMS ON GOING THROUGH THE OVERNIGHT HOURS FOR THE VA
TIDEWATER AND NERN NC. AGAIN EXPECT MVFR TO IFR CONDITIONS IN THE
SHOWERS/THUNDERSTORMS.
AFTER 6Z...EXPECT THE BEST FORCING TO MOVE OFF THE COAST AND WITH
THE WINDS EXPECTED TO WEAKEN...WILL SEE A VERY MOIST ATMOSPHERE
WILL LITTLE STIRRING...WHICH SHOULD ALLOW LOW STRATUS TO FORM WITH
SOME FOG. HAVE A PERIOD OF MVFR VIS/IFR CEILINGS UNTIL THE FRONT
CROSSES THE AREA BETWEEN ABOUT 10Z AND 15Z SATURDAY. ONCE THE
FRONT CLEARS AND THE WINDS START TO PICK UP FROM THE
NORTHWEST...EXPECT TO SEE IMPROVING CEILINGS AND VISIBILITIES AS
DRIER AIR MOVES IN FROM THE NORTHWEST. ANY LINGERING SHOWERS WITH
THE UPPER LOW WILL IMPACT THE AREA SATURDAY AFTERNOON WITH SOME
MVFR SHOWERS.
OUTLOOK...HIGH PRESSURE RETURNS SAT NIGHT THROUGH MONDAY NIGHT
WITH MAINLY VFR CONDITIONS EXPECTED.
&&
.MARINE...
HIGH PRESSURE IS SITUATED WELL OFFSHORE THIS AFTN...WITH A
COLD PUSHING TOWARD THE WRN SLOPES OF THE APPALACHIANS. MOISTURE
AHEAD OF THE FRONT HAS TRIGGERED SHOWERS/TSTMS ACROSS THE MARINE
AREA THIS AFTN...WITH A FEW CELLS PRODUCING WIND GUSTS TO 30-40KT.
THE COLD FRONT SLOWLY APPROACHES FROM THE W TONIGHT...AND PUSHES
THROUGH THE AREA SATURDAY MORNING...WITH A SUBSEQUENT NORTHERLY
SURGE SATURDAY AFTN...WITH A SECONDARY SURGE SATURDAY EVENING
THROUGH THE OVERNIGHT HOURS. LOW-END SCA CONDITIONS ARE EXPECTED
OVER THE BAY WITH A 15-20KT N WIND...LIKELY IN TWO SURGES...ONE
SATURDAY AFTN...AND THE OTHER LATER SATURDAY EVENING THROUGH THE
OVERNIGHT HOURS. AN SCA FLAG HAS BEEN RAISED FOR THE BAY TO ACCOUNT
FOR THIS. THE OCEAN IS GENERALLY EXPECTED TO REMAIN SUB-
SCA...ALTHOUGH SEAS COULD BRIEFLY REACH ~5FT OFF THE CURRITUCK OUTER
BANKS LATER SATURDAY NIGHT INTO EARLY SUNDAY AS THE WIND BECOMES
MORE NNE. HIGH PRESSURE BUILDS OVER THE AREA SUNDAY...SLIDES
OFFSHORE MONDAY...AND SETTLES OFF THE SOUTHEAST COAST TUESDAY. SEAS
GENERALLY AVERAGE 2-4FT...WITH 2-3FT WAVES IN THE BAY. ANOTHER COLD
FRONT CROSSES THE AREA TUESDAY NIGHT INTO WEDNESDAY.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 PM SATURDAY TO 7 AM EDT SUNDAY FOR
ANZ632-634.
SMALL CRAFT ADVISORY FROM 1 PM SATURDAY TO 4 AM EDT SUNDAY FOR
ANZ630-631.
&&
$$
SYNOPSIS...SAM
NEAR TERM...MAS/SAM
SHORT TERM...SAM
LONG TERM...AJZ
AVIATION...ESS/DAP
MARINE...AJZ
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
933 PM EDT FRI APR 22 2016
.SYNOPSIS...
A COLD FRONT PUSHES ACROSS THE AREA AND OFF THE COAST EARLY
SATURDAY MORNING. AN UPPER LEVEL DISTURBANCE WILL DROP THROUGH THE
REGION SATURDAY. HIGH PRESSURE RETURNS SATURDAY NIGHT THROUGH
MONDAY. THE NEXT COLD FRONT DROPS ACROSS THE REGION TUESDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
LATEST GOES WATER VAPOR IMAGERY DEPICTS THE UPPER CLOSED LOW OVER
THE OH VALLEY THIS AFTERNOON WITH A PLUME OF MOISTURE EXTENDING
ALONG THE SOUTHEAST COASTAL PLAIN INTO THE LOCAL AREA. THE COLD
FRONT STILL LAGS OVER CENTRAL OH/KY/TN. LATEST REGIONAL RADAR
DEPICTS BROAD AREA OF SHOWERS EAST OF INTERSTATE 95 WITH SCATTERED
SHOWERS WEST. ONLY LINGER THUNDER REMAINS OVER THE ERN SHORE NEAR
THE COAST. THE NEXT BATCH OF SHOWERS AND EMBEDDED THUNDER IS LOCATED
OVER CENTRAL AND EASTERN NC. HI-RES GUIDANCE LIFTS THE SHOWERS INTO
THE SE HALF OF THE LOCAL AREA THRU THE REST OF THE AFTERNOON.
ANOTHER AREA OF SHOWERS ASSOCIATED WITH THE NEXT PLUME OF MOISTURE
AND THE UPPER LOW PUSHES INTO THE PIEDMONT...BUT IS EXPECTED TO
REMAIN SCATTERED. SHOWERS HAVE LIMITED WHAT LITTLE INSTABILITY THERE
WAS...BUT TEMPS REMAIN IN THE MID 70S ACROSS NE NC. RAP GUIDANCE
INDICATES MLCAPE VALUES AROUND 500 J/KG. WILL KEEP MENTION OF CHANCE
THUNDER WITH LIKELY POPS. PRECIP BEGINS TO TAPER OFF INLAND THIS
EVENING AS THE COLD FRONT APPROACHES. EXPECT ONLY SCATTERED SHOWERS
ALONG THE FRONT AS IT REACHES THE AREA AROUND MIDNIGHT. YET ANOTHER
WAVE CURRENTLY ASSOCIATED WITH PRECIP OVER GA/SC IS PROGGED TO LIFT
INTO THE SE LOCAL AREA OVERNIGHT. THE ADDED LIFT FROM THE
APPROACHING UPPER LOW AND COLD FRONT WILL ENHANCE PRECIP ACROSS THE
SE VA/NE NC AGAIN. LIKELY POPS PREVAIL ALONG THE COAST THRU THE
OVERNIGHT.
MILD TEMPS EXPECTED OVERNIGHT WITH CLOUDS/PRECIP. LOWS GENERALLY IN
THE MID/UPPER 50S INLAND TO LOW 60S SOUTHEAST.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
SFC FRONT PUSHES OFFSHORE SAT MORNING AS THE UPPER LEVEL FRONT LAGS
BEHIND. SHORTWAVE DROPS OVER THE LOCAL AREA SAT AFTERNOON...PUSHING
OFFSHORE SAT EVENING. PWATS DROP TO AOB 1 INCH SAT...BUT CROSS
SECTIONS AND BUFR SOUNDINGS INDICATE REMNANT MID LEVEL MOISTURE.
ADDED FORCING FOR ASCENT AND SHARPENING LAPSE RATES AS COLDER AIR
ALOFT ADVECTS INTO THE REGION WILL RESULT IN ONGOING CHANCES FOR
SHOWERS SAT MORNING. THE BEST CHANCES WILL BE ALONG THE COAST...BUT
STILL EXPECT LIGHT SHOWERS INLAND. MOISTURE REMAINS RATHER
SHALLOW...SO EXPECT ONLY A FEW TENTHS OF AN INCH AT BEST. NLY WINDS
INCREASE TO 10 TO 15 MPH SAT AFTERNOON WITH CLEARING SKIES NW TO SE
THRU THE AFTERNOON. MODEST CAA (AT BEST) AND MIXING WILL PUSH TEMPS
BACK INTO THE LOW/MID 70S (COOLER ALONG THE COAST).
UPPER/SFC HIGH PRESSURE BUILDS OVER THE REGION SAT NIGHT...LOCATING
OVER THE MID ATLANTIC REGION SUN. EXPECT A CLEAR/SUNNY SKY WITH
SEASONABLE TEMPERATURES. LOWS SAT NIGHT IN THE MID/UPPER 40S TO LOW
50S AND HIGHS SUN IN THE LOW 70S INLAND AND MID/UPPER 60S NEAR THE
COAST. LIGHT ONSHORE FLOW WILL RESULT IN TEMPS IN THE UPPER 50S
ALONG THE IMMEDIATE COAST. THE HIGH PUSHES OFFSHORE SUN NIGHT WITH
SLY/RETURN FLOW FORECAST INTO MONDAY. LOWS SUN NIGHT IN THE UPPER
40S TO LOW 50S. SUNNY MONDAY AND WARM AS H85 TEMPS WARM TO AROUND
12C (+1 STD DEV). THICKNESSES YIELD TEMPS IN THE LOW/MID 80S UNDER A
SUNNY SKY. HIGH CLOUDS MAY INCREASE LATE MON AS THE NEXT COLD FRONT
APPROACHES THE REGION FROM THE NW.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
HIGH PRESSURE SETTLES OFF THE SOUTHEAST COAST BY TUESDAY.
MEANWHILE...A SHORTWAVE TROUGH AND AN ASSOCIATED COLD FRONT APPROACH
FROM THE NW BY TUESDAY AFTN. TUESDAY CONTINUES TO TREND TOWARD BEING
A VERY WARM DAY WITH DEEP LAYER WSW FLOW ASSOCIATED WITH A BREAKING
DOWN UPPER RIDGE OVER THE E-CENTRAL/SERN CONUS. MODEL CONSENSUS
GENERALLY SUPPORTS 850MB TEMPERATURES OF 12-15C...WHICH WITH FULL
MIXING AND DOWNSLOPING SHOULD EASILY PUSH HIGHS TO THE LOW/MID 80S W
OF THE BAY...WITH UPPER 70S FOR THE ERN SHORE...AFTER MORNING LOWS
IN THE UPPER 50S TO LOW 60S. SKY COVER SHOULD GENERALLY BE MOSTLY
CLEAR MONDAY NIGHT...AND BECOME PARTLY SUNNY BY TUESDAY. THE TROUGH
AND COLD FRONT SWING THROUGH THE AREA TUESDAY AFTN INTO TUESDAY
NIGHT. THE MAIN FORCING ASSOCIATED WITH THE MID/UPPER SHORTWAVE
TROUGH GENERALLY PASSES N OF THE LOCAL AREA...AND DEEP LAYER RH
DIMINISHES AS THE FEATURE PASSES OVER THE LOCAL AREA SO FORECAST
POPS FOR SHOWERS/TSTMS REMAIN ~20%...WITH A STRIP OF 30% ACROSS THE
FAR N...AND 40% FOR THE LOWER MD ERN SHORE. HIGH PRESSURE BUILDS IN
FROM THE N WEDNESDAY...AND SLIDES OFFSHORE THURSDAY. HIGHS WEDNESDAY
SHOULD DROP BACK TO THE MID/UPPER 60S NE...TO THE MID/UPPER 70S
FARTHER INLAND...AND THEN TREND UPWARD THURSDAY INTO THE MID 70S TO
LOW 80S AS THE HIGH SLIDES OFFSHORE. LOWS SHOULD GENERALLY BE IN THE
50S. A WEAK COLD FRONT SWINGS ACROSS THE AREA LATER IN THE WEEK WITH
ONLY A MINIMAL CHC FOR SHOWERS/TSTMS.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
PRECIPITATION WIDESPREAD ACROSS THE AREA IN THE WARM MOIST
SOUTHERLY FLOW AHEAD OF A COLD FRONT THAT IS MOVING THROUGH
WVA AS OF 01Z.
WAVE MOVING THROUGH THE SE WILL GET PULLED NORTHWARD AHEAD OF THE
NORTHERN STREAM TROUGH TONIGHT AND WILL KEEP THE THREAT FOR
RAIN/STORMS ON GOING THROUGH THE OVERNIGHT HOURS FOR THE VA
TIDEWATER AND NERN NC. AGAIN EXPECT MVFR TO IFR CONDITIONS IN THE
SHOWERS/THUNDERSTORMS.
AFTER 6Z...EXPECT THE BEST FORCING TO MOVE OFF THE COAST AND WITH
THE WINDS EXPECTED TO WEAKEN...WILL SEE A VERY MOIST ATMOSPHERE
WILL LITTLE STIRRING...WHICH SHOULD ALLOW LOW STRATUS TO FORM WITH
SOME FOG. HAVE A PERIOD OF MVFR VIS/IFR CEILINGS UNTIL THE FRONT
CROSSES THE AREA BETWEEN ABOUT 10Z AND 15Z SATURDAY. ONCE THE
FRONT CLEARS AND THE WINDS START TO PICK UP FROM THE
NORTHWEST...EXPECT TO SEE IMPROVING CEILINGS AND VISIBILITIES AS
DRIER AIR MOVES IN FROM THE NORTHWEST. ANY LINGERING SHOWERS WITH
THE UPPER LOW WILL IMPACT THE AREA SATURDAY AFTERNOON WITH SOME
MVFR SHOWERS.
OUTLOOK...HIGH PRESSURE RETURNS SAT NIGHT THROUGH MONDAY NIGHT
WITH MAINLY VFR CONDITIONS EXPECTED.
&&
.MARINE...
HIGH PRESSURE IS SITUATED WELL OFFSHORE THIS AFTN...WITH A
COLD PUSHING TOWARD THE WRN SLOPES OF THE APPALACHIANS. MOISTURE
AHEAD OF THE FRONT HAS TRIGGERED SHOWERS/TSTMS ACROSS THE MARINE
AREA THIS AFTN...WITH A FEW CELLS PRODUCING WIND GUSTS TO 30-40KT.
THE COLD FRONT SLOWLY APPROACHES FROM THE W TONIGHT...AND PUSHES
THROUGH THE AREA SATURDAY MORNING...WITH A SUBSEQUENT NORTHERLY
SURGE SATURDAY AFTN...WITH A SECONDARY SURGE SATURDAY EVENING
THROUGH THE OVERNIGHT HOURS. LOW-END SCA CONDITIONS ARE EXPECTED
OVER THE BAY WITH A 15-20KT N WIND...LIKELY IN TWO SURGES...ONE
SATURDAY AFTN...AND THE OTHER LATER SATURDAY EVENING THROUGH THE
OVERNIGHT HOURS. AN SCA FLAG HAS BEEN RAISED FOR THE BAY TO ACCOUNT
FOR THIS. THE OCEAN IS GENERALLY EXPECTED TO REMAIN SUB-
SCA...ALTHOUGH SEAS COULD BRIEFLY REACH ~5FT OFF THE CURRITUCK OUTER
BANKS LATER SATURDAY NIGHT INTO EARLY SUNDAY AS THE WIND BECOMES
MORE NNE. HIGH PRESSURE BUILDS OVER THE AREA SUNDAY...SLIDES
OFFSHORE MONDAY...AND SETTLES OFF THE SOUTHEAST COAST TUESDAY. SEAS
GENERALLY AVERAGE 2-4FT...WITH 2-3FT WAVES IN THE BAY. ANOTHER COLD
FRONT CROSSES THE AREA TUESDAY NIGHT INTO WEDNESDAY.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 PM SATURDAY TO 7 AM EDT SUNDAY FOR
ANZ632-634.
SMALL CRAFT ADVISORY FROM 1 PM SATURDAY TO 4 AM EDT SUNDAY FOR
ANZ630-631.
&&
$$
SYNOPSIS...SAM
NEAR TERM...SAM
SHORT TERM...SAM
LONG TERM...AJZ
AVIATION...ESS/DAP
MARINE...AJZ
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
623 PM EDT THU APR 21 2016
.SYNOPSIS...
LOW PRESSURE WILL BRING PERIODIC SHOWER CHANCES THROUGH FRIDAY
EVENING. HIGH PRESSURE WILL BRING DRY AND SEASONAL WEATHER THIS
WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
QUICK UPDATE TO THE FORECAST TO ADD MENTION OF ISOLATED
THUNDERSTORMS AS LATEST RADAR SHOWS A FEW RELATIVELY WEAK STORMS
POP UP OVER EASTERN OHIO /WESTERN PA. LATEST RAPID UPDATE RUNS
PICK THIS UP REASONABLY WELL SO HAVE ALSO WEIGHTED POPS OVER THE
NEXT SEVERAL HOURS TOWARDS THE LATEST HRRR AND RAP. HOURLY
TEMPERATURES ACROSS WESTERN ZONES WERE ALSO ADJUSTED DOWN AS RAIN
FALLING THROUGH THE INITIALLY VERY DRY LOWER LEVELS QUICKLY
LOWERED TEMPERATURES A COUPLE DEGREES.
SHOWERS ARE EXPECTED TO INCREASE IN COVERAGE LATE THIS
EVENING...PRIMARILY WEST OF LINE RUNNING ROUGHLY FROM INDIANA TO
PARKERSBURG AS A SHORTWAVE TROUGH TRANSITIONS NORTHEAST ACROSS THE
UPPER OHIO VALLEY AHEAD OF THE PARENT UPPER LOW. ITS POSSIBLE WE
MAY NEED TO INCLUDE MENTION OF ISOLATED THUNDERSTORMS WITH THE
NEXT UPDATE AS WELL AS THERE IS SOME ELEVATED INSTABILITY ON
LATEST MODEL SOUNDINGS...AND THE CROSSING SHORTWAVE MAY BE JUST
ENOUGH OF A KICKER. AT THE MOMENT...THE PROGGED INSTABILITY IS
JUST TOO WEAK. OVERNIGHT LOW TEMPERATURES WILL RANGE 10-15 DEG
ABOVE NORMAL WITH CONTINUED WARM AIR ADVECTION AND CLOUD COVERAGE
LIMITING ANY RADIATIONAL COOLING.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
SHOWERS SHOULD TAPER OFF IN COVERAGE FRI MRNG AS THE INITIAL
SHORTWAVE EXITS. THE UPR LOW/TROF...AND IT/S ASSOCIATED SFC COLD
FRONT...IS EXPECTED TO ADVANCE E TWD THE AREA BY AFTN WITH
INCREASING SHOWER POTENTIAL RETURNING. MODEL PROGS SHOW A
POTENTIAL FOR WEAK INSTABILITY...SO ONLY INCLUDED A SLGT CHC OF A
TSTM. THE FRONT SHOULD COMPLETE IT/S PASSAGE FRI NIGHT...THOUGH
SHOWER CHCS SHOULD CONTINUE UNTIL THE UPR TROF AXIS MOVES E OF
THE AREA SAT MRNG.
BUILDING RIDGING IS THEN EXPECTED TO BRING DRY WEATHER THROUGH
THE REST OF THE WEEKEND. TEMPERATURES ARE EXPECTED TO AVERAGE
NEAR OR SEVERAL DEGREES ABOVE SEASONAL LVLS USING GFS MOS AND A
CONSENSUS BLEND GUIDANCE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
A COLD FRONT WILL SLOWLY CROSS THE REGION LATER MONDAY THROUGH
TUESDAY BRINGING SHOWERS. BUBBLE OF HIGH PRESSURE WITH DRY BUT
STILL MILD CONDITIONS WEDNESDAY. LOW PRESSURE ADVANCING FROM THE
NATIONS MID SECTION WILL RETURN SHOWERS FOR LATE WEEK. A SLIGHTLY
MODIFIED SUPERBLEND WAS USED FOR THE EXTENDED FORECAST.
&&
.AVIATION /22Z THURSDAY THROUGH TUESDAY/...
GENERAL VFR EARLY TONIGHT AS LOW LEVELS SLOWLY MOISTEN AHEAD OF
APPROACHING LOW PRESSURE. DEEPER MOISTURE AND BETTER LIFT WILL
GIVE MVFR IN SHOWERS BEFORE DAYBREAK FRIDAY WITH IFR CIGS INTO
NORTHERN PORTS.
.OUTLOOK /FRIDAY THROUGH TUESDAY/...
RESTRICTIONS EXPECTED FRIDAY AS LOW PRESSURE MOVES EAST. NEXT
CHANCE FOR WIDESPREAD RESTRICTIONS WILL BE MONDAY NIGHT AND
TUESDAY AS A COLD FRONT APPROACHES.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
407 PM EDT THU APR 21 2016
.SYNOPSIS...
HIGH PRESSURE REMAINS OVER THE WESTERN ATLANTIC TONIGHT. A COLD
FRONT WILL APPROACH FROM THE WEST FRIDAY...PUSHING OFF THE COAST
EARLY SATURDAY MORNING. AN UPPER LEVEL DISTURBANCE DROPS OVER THE
REGION SATURDAY. HIGH PRESSURE RETURNS FOR SATURDAY NIGHT INTO
MONDAY. THE NEXT COLD FRONT PUSHES ACROSS THE REGION TUESDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
LATEST REGIONAL RADAR MOSAIC DEPICTS ISOLATED TO SCATTERED SHOWERS
AND THUNDERSTORMS EXTENDING FROM SE NC INTO CENTRAL NC THIS
AFTERNOON. BASED ON LATEST SFC OBS...THE WARM FRONT HAS LIFTED INTO
THE LOCAL AREA...WITH BETTER DESTABILIZATION SOUTH OF THE LOCAL
AREA. EXPECT THE BETTER INSTABILITY TO REMAIN SOUTH OF THE
REGION...BUT HI-RES GUIDANCE CONTINUES TO INDICATE THE POTENTIAL FOR
ISOLATED TO WIDELY SCATTERED SHOWERS LIFTING INTO SRN VA AND NE NC
THRU LATE THIS AFTERNOON. NAM12 300K SURFACES BACK UP THIS
SCENARIO...INDICATING LOW LEVEL LIFT EVEN UNDER THE UPPER LEVEL RIDGE
LOCATED OVER THE ERN CONUS. RAP SOUNDINGS INDICATE MODEST CAPE
EXTENDING INTO THE MIXED PHASE LAYER...SO WILL MENTION SLIGHT CHANCE
FOR THUNDER. ANY SHOWERS THAT DO DEVELOP WILL DISSIPATE EARLY
EVENING WITH THE LOSS OF DAYTIME HEATING.
TEMPS HAVE WARMED INTO THE MID/UPPER 70S...WITH A FEW LOCALES
HITTING 80 ACROSS THE PIEDMONT INTO CENTRAL VA. SOUTH WINDS AROUND
10 MPH TONIGHT ALONG WITH A PARTLY CLOUDY SKY WILL RESULT IN MILD
OVERNIGHT TEMPS. LOWS GENERALLY IN THE LOW 60S (~+1 STD DEV OR 10-12
DEGS ABOVE NORMAL).
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
GENERAL MODEL TRENDS CONTINUE TO SLOW THE UPPER SYSTEM SLIGHTLY AND
DIG IT FARTHER SOUTH AND WEST THROUGH FRIDAY NIGHT. CURRENT NATIONAL
RADAR TRENDS OVER THE OH VALLEY...DEPICT RATHER UNORGANIZED
CONVECTION ASSOCIATED WITH THE UPPER LOW. THE UPPER LOW PUSHES INTO
THE TN VALLEY AS A STRONG UPPER LOW DEEPENS OVER ERN CANADA. THE
FRONT REACHES THE ERN VA PIEDMONT LATE FRIDAY INTO EARLY FRI
EVENING. LEAD SHORTWAVE ENERGY ROUNDS THE BASE OF THE UPPER
TROUGH...LIFTING INTO THE REGION FRI AFTERNOON AHEAD OF THE MAIN
TROUGH ENERGY. RETURN FLOW ADVECTS DEEPER MOISTURE INTO THE
REGION...WITH H85 FLOW COMING IN FROM THE GULF STREAM. POPS RAMP UP
OVER THE PIEDMONT MID TO LATE MORNING...AND THEN POINTS EWD THROUGH
EARLY AFTERNOON. THE FAVORED AREAS FOR SHOWERS CONTINUE TO BE ALONG
AND SOUTH OF A LINE FROM FARMVILLE TO RICHMOND AND TO THE NRN
NECK/MD ERN SHORE FRI AFTERNOON AND FRIDAY EVENING. HAVE MAINTAINED
LIKELY POPS FOR THAT AREA. HAVE TRIMMED BACK POPS NORTH AND WEST OF
THIS LINE AS MODELS INDICATE SHOWER COVERAGE ASSOCIATED WITH THE
MAIN SHORTWAVE WILL BE LIMITED IN THAT REGION. THUNDERSTORM
POTENTIAL REMAINS MARGINAL DUE TO CONSIDERABLE CLOUD COVER AND
MARGINAL INSTABILITY. GIVEN THE DYNAMICS...THETA-E ADVECTION AND THE
TIME OF YEAR...WILL KEEP CHANCE MENTION OF THUNDER. SHEAR REMAINS
MODEST (AOB 30 KT)...SO EXPECT ONLY EMBEDDED THUNDER. PWATS CLIMB TO
1.25 TO 1.5 INCHES...WHICH MAY RESULT IN PERIODS OF MODERATE TO
LOCALLY HEAVY RAINFALL. HOWEVER...QPF AMOUNTS THRU FRIDAY EVENING
WILL GENERALLY RANGE FROM LESS THAN ONE QUARTER OF AN INCH ACROSS
THE NORTH UP TO ONE HALF INCH ACROSS THE SOUTH. AREA REMAINS IN WARM
SECTOR WITH RETURN FLOW PUSHING TEMPS BACK INTO THE MID/UPPER
70S...EVEN WITH CONSIDERABLE CLOUD COVER. SHORTWAVE DROPS OVER THE
CENTRAL APPALACHIANS INTO THE LOCAL AREA THRU FRI NIGHT AS THE FRONT
PUSHES OFFSHORE. WILL KEEP SOLID CHANCE POPS ALONG THE COAST THRU
THE OVERNIGHT PERIOD.
AFOREMENTIONED MODEL TRENDS MEAN LINGERING MID LEVEL MOISTURE TO
GO ALONG WITH THE STRONG DYNAMICS PROVIDED BY THE UPPER LOW DROPPING
OVER THE REGION SAT. WILL HOLD ONTO SOLID CHANCE POPS THROUGH LATE
MORNING INLAND FOR SCATTERED SHOWERS...AND ALONG THE COAST THRU SAT
AFTERNOON. CLOUDY CONDITIONS BECOME PARTLY CLOUDY INLAND SAT
AFTERNOON...BUT REMAIN MOSTLY CLOUDY ALONG THE COAST. TRENDED TOWARD
THE COOLER SIDE OF THE MOS GUIDANCE DUE TO CLOUD COVER AND MODEST
CAA...BUT TEMPS REMAIN SEASONABLE IN THE UPPER 60S/LOW 70S.
NORTH WINDS GENERALLY 10 TO 15 MPH WITH GUSTS OF 20 TO 25 MPH. TROUGH
AXIS PUSHES OFFSHORE SAT NIGHT WITH DRY CONDITIONS FORECAST ACROSS
THE AREA. LOWS IN THE MID/UPPER 40S INLAND TO LOW 50S NEAR THE COAST
UNDER A CLEAR SKY. HIGH PRESSURE BUILDS ACROSS NEW ENGLAND SAT
NIGHT...PARKING OFF THE NORTHEAST COAST SUNDAY. THE RESULT WILL BE
ONGOING DRY CONDITIONS. CAA WANES SUN...BUT LIGHT ONSHORE FLOW WILL
KEEP TEMPS IN CHECK. THICKNESSES YIELD TEMPS IN THE LOW/MID 70S
INLAND AND MID/UPPER 60S ALONG THE COAST.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
HIGH PRESSURE SLIDES FARTHER OFFSHORE SUNDAY NIGHT AND MONDAY...AND
SETTLES OFF THE SOUTHEAST COAST BY TUESDAY. MEANWHILE...A SHORTWAVE
TROUGH AND AN ASSOCIATED COLD FRONT APPROACH FROM THE NW BY TUESDAY
AFTN. MONDAY AND TUESDAY ARE TRENDING TOWARD BEING VERY WARM DAYS
WITH DEEP LAYER WSW FLOW ASSOCIATED WITH A BREAKING DOWN UPPER RIDGE
OVER THE E-CENTRAL/SERN CONUS. MODEL CONSENSUS GENERALLY SUPPORTS
850MB TEMPERATURES OF 12-15C...WHICH WITH FULL MIXING AND
DOWNSLOPING SHOULD EASILY PUSH HIGHS TO 80-85F W OF THE BAY...WITH
UPPER 70S FOR THE ERN SHORE. LOWS SUNDAY NIGHT SHOULD BE IN THE
LOW/MID 50S...WITH 55-60F MONDAY NIGHT. SKY COVER SHOULD GENERALLY
BE MOSTLY CLEAR/SUNNY SUNDAY NIGHT...MONDAY INTO MONDAY NIGHT...AND
BECOME PARTLY SUNNY TUESDAY. THE TROUGH AND COLD FRONT SWING THROUGH
THE AREA TUESDAY AFTN INTO TUESDAY NIGHT. THE MAIN FORCING
ASSOCIATED WITH THE MID/UPPER SHORTWAVE TROUGH GENERALLY PASSES N OF
THE LOCAL AREA...AND DEEP LAYER RH DIMINISHES AS THE FEATURE PASSES
OVER THE LOCAL AREA SO FORECAST POPS ARE ONLY 20%...WITH A NARROW
STRIP OF 30% ACROSS THE FAR N. HIGH PRESSURE BUILDS IN FROM THE N
WEDNESDAY...AND SLIDES OFFSHORE LATER IN THE WEEK. HIGHS WEDNESDAY
SHOULD DROP BACK TO THE MID/UPPER 60S NE...TO THE MID/UPPER 70S
FARTHER INLAND...AND THEN TREND UPWARD INTO THURSDAY AS THE HIGH
SLIDES OFFSHORE. LOWS SHOULD GENERALLY BE IN THE 50S.
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
VFR CONDS CONTG THROUGH BALANCE OF FCST PD. SCT-BKN CU 4-6KFT
THROUGH ABT 22-23Z/21...THEN BKN-OVC AC-CI INTO OVRNGT HRS. BKN SC
(2-3KFT) PSBL LT TNGT INTO FRI AS MOISTURE INCREASES AHEAD OF
APPROACHING CDFNT FM THE W. AN ISOLD SHRA...ESP AT THE CST...PSBL
AFT 03-06Z/22...OTRW WILL HAVE MVFR CONDS AND PSBL SCT SHRAS AS
CDFNT APPROACHES RIC ON FRI. MNLY MVFR CONDS AND SCT-LIKELY SHRAS
(SLGT CHC TSTM) FRI AFTN/NGT.
GRADUAL CLEARING OUT/BECOMING VFR SAT AFTN...W/ DRY AND VFR CONDS
CONTG THROUGH MON.
&&
.MARINE...
HIGH PRESSURE IS SITUATED WELL OFFSHORE THIS AFTN...WITH
LOW PRESSURE WELL TO THE W OVER THE MID-MISSISSIPPI VALLEY. THE HIGH
WILL CONTINUE TO SLIDE FARTHER OFFSHORE TONIGHT AS LOW PRESSURE
LIFTS NE OVER THE GREAT LAKES. A SW WIND SHOULD AVERAGE 10-15KT
THROUGH THIS EVENING...AND THEN INCREASE TO 15KT BAY/15-20KT OCEAN
LATER THIS EVENING THROUGH FRIDAY MORNING...BEFORE DIMINISHING
FRIDAY AFTN/EVENING AS THE PRESSURE GRADIENT SLACKENS AS A WEAK COLD
FRONT GRADUALLY DROPS INTO THE REGION. THE COLD FRONT PUSHES THROUGH
THE AREA EARLY SATURDAY MORNING...WITH A SUBSEQUENT NORTHERLY SURGE
MIDDAY SATURDAY...WITH A SECONDARY SURGE SATURDAY EVENING. MARGINAL
SCA CONDITIONS ARE POSSIBLE OVER THE BAY (15-20KT N WIND). HIGH
PRESSURE BUILDS OVER THE AREA SATURDAY NIGHT AND SUNDAY...SLIDES
OFFSHORE MONDAY...AND SETTLES OFF THE SOUTHEAST COAST TUESDAY. SEAS
GENERALLY AVERAGE 2-4FT...WITH 2-3FT WAVES IN THE BAY.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SAM/TMG
NEAR TERM...SAM
SHORT TERM...SAM
LONG TERM...AJZ
AVIATION...ALB/MPR
MARINE...AJZ
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
218 PM EDT THU APR 21 2016
.SYNOPSIS...
HIGH PRESSURE REMAINS OVER THE WESTERN ATLANTIC TODAY. A COLD FRONT
WILL APPROACH FROM THE WEST FRIDAY...PUSHING OFF THE COAST LATE
FRIDAY NIGHT THROUGH SATURDAY MORNING. HIGH PRESSURE RETURNS FOR
SATURDAY AFTERNOON INTO MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATEST GOES WATER VAPOR IMAGERY DEPICTS AN UPPER LEVEL CLOSED LOW
OVER IA THIS MORNING...WITH AN UPPER LEVEL RIDGE OVER THE ERN CONUS.
AT THE SFC...HIGH PRESSURE HAS CENTERED OFFSHORE AS A BROAD AREA OF
LOW PRESSURE ASSOCIATED WITH THE UPPER LOW HAS LOCATED OVER THE
UPPER MIDWEST. THE ATTENDANT COLD FRONT EXTENDS SWWD INTO THE SRN
PLAINS. BETWEEN THESE SFC FEATURES...SLY/RETURN FLOW OVER THE LOCAL
AREA HAS RESULTED IN INCREASING MOISTURE/DEWPOINTS. AN INFLUX IN MID
LEVEL MOISTURE AHEAD OF THE APPROACHING STORM SYSTEM WILL RESULT IN
A PARTLY CLOUDY TO MOSTLY CLOUDY SKY TODAY. THE RAP INDICATES A WEAK
VORT MAX PUSHING ACROSS THE NRN NECK LATE THIS MORNING...WHICH IS
JUST ENOUGH FORCING TO PRODUCE ISOLATED LIGHT SHOWERS. ELSEWHERE...A
LACK OF APPRECIABLE FORCING AND STABLE CONDITIONS UNDER THE UPPER
LEVEL RIDGE WILL RESULT IN DRY CONDITIONS THRU MID AFTERNOON.
SHOWERS OVER THE NRN NECK EXPECTED TO DISSIPATE LATE MORNING/EARLY
AFTERNOON. A WARM FRONT LIFTS ACROSS THE REGION TODAY...WITH MODEST
DESTABILIZATION EXPECTED ACROSS SRN VA AND SE VA/NE NC. MOISTURE
RETURN AND LIFT INDICATED IN THE 300K SURFACES WILL RESULT IN
SHOWERS ACROSS THE AFOREMENTIONED REGION THIS AFTERNOON. AGAIN...A
LACK OF STRONG FORCING FOR ASCENT AND DEEP MOISTURE WILL RESULT IN
ONLY ISOLATED TO WIDELY SCATTERED LIGHT SHOWERS. RETURN FLOW OF 10
TO 15 MPH WILL PUSH TEMPS INTO THE LOW/MID 70S...EVEN WITH CLOUD
COVER.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
EXPECT DRY CONDITIONS TO PREVAIL TNGT...AS A COLD FRONT WILL BE
PUSHING INTO/THRU THE OH AND TN VALLEYS. BUT...WILL KEEP SLIGHT
CHC/CHC POPS FOR EXTRM NW COUNTIES...IN CASE A FEW SHOWERS WELL IN
ADVANCE OF THE FRONT MAKE IT INTO THESE AREAS TWD FRI MORNG. IN
ADDITION...SMOKE FM FIRES IN ERN NC WILL SPREAD SMOKE NWD INTO NE
NC. AN AIR QUALITY ALERT WILL REMAIN IN EFFECT FOR THOSE AREAS
INTO EARLY FRI MORNG. MILD TNGT WITH LOWS IN THE UPR 50S TO LWR
60S.
AFOREMENTIONED UPR LO CONTINUES TO DE-AMPLIFY AS IT TRACKS THRU
THE OH VALLEY DURING FRI...PUSHING THE COLD FRONT INTO WRN VA/NC
BY 00Z SAT. PWATS PROGGED IN THE 1.25 TO 1.4 INCH RANGE AHEAD OF
THE FRONT (+1 STD DEV) FRI AFTN. FORECAST CONTINUES TO FAVOR THE
PROGRESSIVE RUNS OF THE GFS/ECMWF...WITH SHOWERS SPREADING INTO
THE PIEDMONT AND CNTRL VA FRI MORNG...AND THE REST OF THE AREA
FRI AFTN INTO FRI EVENG. INSTABILITY REMAINS MARGINAL ALONG WITH
MEAGER LAPSE RATES AND MODEST SHEAR. ALSO...LITTLE IF ANY
INSTABILITY EXISTS IN THE MIXED PHASE LAYER. HOWEVER...GIVEN THE
TIME OF DAY AND CLIMO...CANNOT RULE OUT EMBEDDED THUNDER AND WILL
LEAVE CHC IN THE FCST. MAIN CONCERN FRI WILL BE THE LACK OF
ADEQUATE FORCING FOR ASCENT...AS THE BEST HEIGHT FALLS REMAIN N
OF THE REGION. IF WE GET ENOUGH LIFT AND MOISTURE FEED...QPF AMTS
COULD RANGE FM .20 TO .40 INCH WITH THESE FRONT. WARM SECTOR AND
RETURN FLO WILL PUSH TEMPS INTO THE MID TO UPR 70S...EVEN WITH
MOSTLY CLOUDY CONDITIONS AND INCOMING PCPN. SHOWERS...AND POSSIBLY
A TSTM...WILL NOW LINGER OVR CNTRL/ERN COUNTIES INTO FRI NGT...AS
00Z/21 GFS/ECMWF MODEL RUNS ARE A LITTLE SLOWER. BULK OF PCPN WILL
MOVE OFF THE CST BY 12Z SAT.
MAINTAINED A SLGT CHC OVR THE REGION THRU SAT MORNG UNTIL THE UPR
TROF SHIFTS OFF THE CST BY 18Z. THEN...DRY CONDITIONS EXPECTED
SAT AFTN INTO SAT NGT...AS HI PRES BLDS IN FM THE NNW. ONLY
EXPECT MODEST CAA BEHIND THE FRONT...AS H85 TEMPS DROP ONLY A FEW
DEGS COMPARED TO FRI...RANGING FROM 6 TO 8C. EXPECT N WINDS OF 10
TO 15 MPH SAT. HIGHS GENERALLY IN THE LWR TO MID 70S (COOLER ALNG
THE CST).
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
HIGH PRESSURE BUILDS INTO THE MID-ATLANTIC SATURDAY NIGHT AND
GRADUALLY SLIDES OFFSHORE SUNDAY. MOSTLY CLEAR/SUNNY AND DRY
CONDITIONS ARE EXPECTED. LOWS SATURDAY NIGHT WILL BE SEASONALLY COOL
DROPPING INTO THE MID/UPPER 40S FOR MOST OF THE AREA...WITH LOW 50S
FOR SE COASTAL LOCATIONS. HIGHS SUNDAY MODERATE INTO THE LOW/MID 70S
FOR MOST OF THE AREA...BUT ONLY IN THE 60S FOR THE ERN SHORE DUE TO
LIGHT ONSHORE FLOW. THE HIGH SLIDES FARTHER OFFSHORE SUNDAY NIGHT
AND MONDAY AS A COLD FRONT APPROACHES FROM THE N MONDAY. 20/12Z
NUMERICAL GUIDANCE GENERALLY KEEPS THE BOUNDARY N OF THE LOCAL AREA
THROUGH THE DAY MONDAY...WHICH WOULD PLACE THE LOCAL AREA IN DEEP
LAYER SW FLOW WITH A MID/UPPER RIDGE BREAKING DOWN. THIS WOULD
RESULT IN A RATHER WARM DAY...AND HIGHS HAVE BEEN NUDGE UPWARD INTO
THE UPPER 70S/LOW 80S...WITH LOW/MID 70S FOR THE ERN SHORE UNDER A
PARTLY TO MOSTLY SUNNY SKY. THIS IS AFTER LOWS SUNDAY NIGHT IN THE
LOW/MID 50S. THE FRONT GRADUALLY DROPS THROUGH THE AREA TUESDAY. THE
MAIN FORCING ASSOCIATED WITH THE MID/UPPER SHORTWAVE TROUGH
GENERALLY PASSES N OF THE LOCAL AREA...AND DEEP LAYER RH DIMINISHES
AS THE FEATURE PASSES OVER THE LOCAL AREA SO FORECAST POPS ARE ONLY
20-30% (MAINLY N) AT THIS TIME. HIGHS TUESDAY ARE FORECAST TO BE IN
THE 70S AFTER MORNING LOWS IN THE 50S. HIGH PRESSURE BUILDS IN FROM
THE N TROUGH MIDWEEK...AS A LOW PRESSURE SYSTEM WITH LIMITED
MOISTURE APPROACHES FROM THE W. FORECAST HIGHS WEDNESDAY RANGE FROM
THE 60S ALONG THE COAST...TO THE LOW 70S INLAND.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
VFR CONDS CONTG THROUGH BALANCE OF FCST PD. SCT-BKN CU 4-6KFT
THROUGH ABT 22-23Z/21...THEN BKN-OVC AC-CI INTO OVRNGT HRS. BKN SC
(2-3KFT) PSBL LT TNGT INTO FRI AS MOISTURE INCREASES AHEAD OF
APPROACHING CDFNT FM THE W. AN ISOLD SHRA...ESP AT THE CST...PSBL
AFT 03-06Z/22...OTRW WILL HAVE MVFR CONDS AND PSBL SCT SHRAS AS
CDFNT APPROACHES RIC ON FRI. MNLY MVFR CONDS AND SCT-LIKELY SHRAS
(SLGT CHC TSTM) FRI AFTN/NGT.
GRADUAL CLEARING OUT/BECOMING VFR SAT AFTN...W/ DRY AND VFR CONDS
CONTG THROUGH MON.
&&
.MARINE...
WINDS NOW SOUTH AROUND THE HIGH THAT HAS MOVED OFF THE COAST. SOME
CHANNELING POSSIBLE FROM TIME TO TIME TODAY AND TONIGHT...BUT THINK
WINDS WILL AVERAGE BELOW 20 KTS. WAVE GUIDANCE SUGGESTS SEAS OUT
NEAR BUOY 44009 REACH 5 FT FOR A FEW HOURS TONIGHT...BUT CONFIDENCE
IN THIS HAPPENING IS NOT THAT HIGH SO ELECTED TO HOLD OFF ON ANY
HEADLINE WITH THIS FORECAST PACKAGE.
OTW...NEXT CHANCE FOR ANY SCA HEADLINES WILL COME SAT MORNING AS
WINDS TURN NORTH BEHIND A COLD FRONTAL PASSAGE FRI NIGHT. CAA SURGE
APPEARS MINIMAL AT THIS POINT (15-20 KTS) ACROSS THE CHES BAY. HIGH
PRESSURE BUILDS OVER THE AREA SAT NIGHT AND SUN RESULTING IN BETTER
BOATING CONDITIONS.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SAM/TMG
NEAR TERM...SAM
SHORT TERM...SAM/TMG
LONG TERM...AJZ
AVIATION...ALB/MPR
MARINE...AJZ/MPR
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
1104 AM EDT THU APR 21 2016
.SYNOPSIS...
HIGH PRESSURE REMAINS OVER THE WESTERN ATLANTIC TODAY. A COLD FRONT
WILL APPROACH FROM THE WEST FRIDAY...PUSHING OFF THE COAST LATE
FRIDAY NIGHT THROUGH SATURDAY MORNING. HIGH PRESSURE RETURNS FOR
SATURDAY AFTERNOON INTO MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATEST GOES WATER VAPOR IMAGERY DEPICTS AN UPPER LEVEL CLOSED LOW
OVER IA THIS MORNING...WITH AN UPPER LEVEL RIDGE OVER THE ERN CONUS.
AT THE SFC...HIGH PRESSURE HAS CENTERED OFFSHORE AS A BROAD AREA OF
LOW PRESSURE ASSOCIATED WITH THE UPPER LOW HAS LOCATED OVER THE
UPPER MIDWEST. THE ATTENDANT COLD FRONT EXTENDS SWWD INTO THE SRN
PLAINS. BETWEEN THESE SFC FEATURES...SLY/RETURN FLOW OVER THE LOCAL
AREA HAS RESULTED IN INCREASING MOISTURE/DEWPOINTS. AN INFLUX IN MID
LEVEL MOISTURE AHEAD OF THE APPROACHING STORM SYSTEM WILL RESULT IN
A PARTLY CLOUDY TO MOSTLY CLOUDY SKY TODAY. THE RAP INDICATES A WEAK
VORT MAX PUSHING ACROSS THE NRN NECK LATE THIS MORNING...WHICH IS
JUST ENOUGH FORCING TO PRODUCE ISOLATED LIGHT SHOWERS. ELSEWHERE...A
LACK OF APPRECIABLE FORCING AND STABLE CONDITIONS UNDER THE UPPER
LEVEL RIDGE WILL RESULT IN DRY CONDITIONS THRU MID AFTERNOON.
SHOWERS OVER THE NRN NECK EXPECTED TO DISSIPATE LATE MORNING/EARLY
AFTERNOON. A WARM FRONT LIFTS ACROSS THE REGION TODAY...WITH MODEST
DESTABILIZATION EXPECTED ACROSS SRN VA AND SE VA/NE NC. MOISTURE
RETURN AND LIFT INDICATED IN THE 300K SURFACES WILL RESULT IN
SHOWERS ACROSS THE AFOREMENTIONED REGION THIS AFTERNOON. AGAIN...A
LACK OF STRONG FORCING FOR ASCENT AND DEEP MOISTURE WILL RESULT IN
ONLY ISOLATED TO WIDELY SCATTERED LIGHT SHOWERS. RETURN FLOW OF 10
TO 15 MPH WILL PUSH TEMPS INTO THE LOW/MID 70S...EVEN WITH CLOUD
COVER.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
EXPECT DRY CONDITIONS TO PREVAIL TNGT...AS A COLD FRONT WILL BE
PUSHING INTO/THRU THE OH AND TN VALLEYS. BUT...WILL KEEP SLIGHT
CHC/CHC POPS FOR EXTRM NW COUNTIES...IN CASE A FEW SHOWERS WELL IN
ADVANCE OF THE FRONT MAKE IT INTO THESE AREAS TWD FRI MORNG. IN
ADDITION...SMOKE FM FIRES IN ERN NC WILL SPREAD SMOKE NWD INTO NE
NC. AN AIR QUALITY ALERT WILL REMAIN IN EFFECT FOR THOSE AREAS
INTO EARLY FRI MORNG. MILD TNGT WITH LOWS IN THE UPR 50S TO LWR
60S.
AFOREMENTIONED UPR LO CONTINUES TO DE-AMPLIFY AS IT TRACKS THRU
THE OH VALLEY DURING FRI...PUSHING THE COLD FRONT INTO WRN VA/NC
BY 00Z SAT. PWATS PROGGED IN THE 1.25 TO 1.4 INCH RANGE AHEAD OF
THE FRONT (+1 STD DEV) FRI AFTN. FORECAST CONTINUES TO FAVOR THE
PROGRESSIVE RUNS OF THE GFS/ECMWF...WITH SHOWERS SPREADING INTO
THE PIEDMONT AND CNTRL VA FRI MORNG...AND THE REST OF THE AREA
FRI AFTN INTO FRI EVENG. INSTABILITY REMAINS MARGINAL ALONG WITH
MEAGER LAPSE RATES AND MODEST SHEAR. ALSO...LITTLE IF ANY
INSTABILITY EXISTS IN THE MIXED PHASE LAYER. HOWEVER...GIVEN THE
TIME OF DAY AND CLIMO...CANNOT RULE OUT EMBEDDED THUNDER AND WILL
LEAVE CHC IN THE FCST. MAIN CONCERN FRI WILL BE THE LACK OF
ADEQUATE FORCING FOR ASCENT...AS THE BEST HEIGHT FALLS REMAIN N
OF THE REGION. IF WE GET ENOUGH LIFT AND MOISTURE FEED...QPF AMTS
COULD RANGE FM .20 TO .40 INCH WITH THESE FRONT. WARM SECTOR AND
RETURN FLO WILL PUSH TEMPS INTO THE MID TO UPR 70S...EVEN WITH
MOSTLY CLOUDY CONDITIONS AND INCOMING PCPN. SHOWERS...AND POSSIBLY
A TSTM...WILL NOW LINGER OVR CNTRL/ERN COUNTIES INTO FRI NGT...AS
00Z/21 GFS/ECMWF MODEL RUNS ARE A LITTLE SLOWER. BULK OF PCPN WILL
MOVE OFF THE CST BY 12Z SAT.
MAINTAINED A SLGT CHC OVR THE REGION THRU SAT MORNG UNTIL THE UPR
TROF SHIFTS OFF THE CST BY 18Z. THEN...DRY CONDITIONS EXPECTED
SAT AFTN INTO SAT NGT...AS HI PRES BLDS IN FM THE NNW. ONLY
EXPECT MODEST CAA BEHIND THE FRONT...AS H85 TEMPS DROP ONLY A FEW
DEGS COMPARED TO FRI...RANGING FROM 6 TO 8C. EXPECT N WINDS OF 10
TO 15 MPH SAT. HIGHS GENERALLY IN THE LWR TO MID 70S (COOLER ALNG
THE CST).
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
HIGH PRESSURE BUILDS INTO THE MID-ATLANTIC SATURDAY NIGHT AND
GRADUALLY SLIDES OFFSHORE SUNDAY. MOSTLY CLEAR/SUNNY AND DRY
CONDITIONS ARE EXPECTED. LOWS SATURDAY NIGHT WILL BE SEASONALLY COOL
DROPPING INTO THE MID/UPPER 40S FOR MOST OF THE AREA...WITH LOW 50S
FOR SE COASTAL LOCATIONS. HIGHS SUNDAY MODERATE INTO THE LOW/MID 70S
FOR MOST OF THE AREA...BUT ONLY IN THE 60S FOR THE ERN SHORE DUE TO
LIGHT ONSHORE FLOW. THE HIGH SLIDES FARTHER OFFSHORE SUNDAY NIGHT
AND MONDAY AS A COLD FRONT APPROACHES FROM THE N MONDAY. 20/12Z
NUMERICAL GUIDANCE GENERALLY KEEPS THE BOUNDARY N OF THE LOCAL AREA
THROUGH THE DAY MONDAY...WHICH WOULD PLACE THE LOCAL AREA IN DEEP
LAYER SW FLOW WITH A MID/UPPER RIDGE BREAKING DOWN. THIS WOULD
RESULT IN A RATHER WARM DAY...AND HIGHS HAVE BEEN NUDGE UPWARD INTO
THE UPPER 70S/LOW 80S...WITH LOW/MID 70S FOR THE ERN SHORE UNDER A
PARTLY TO MOSTLY SUNNY SKY. THIS IS AFTER LOWS SUNDAY NIGHT IN THE
LOW/MID 50S. THE FRONT GRADUALLY DROPS THROUGH THE AREA TUESDAY. THE
MAIN FORCING ASSOCIATED WITH THE MID/UPPER SHORTWAVE TROUGH
GENERALLY PASSES N OF THE LOCAL AREA...AND DEEP LAYER RH DIMINISHES
AS THE FEATURE PASSES OVER THE LOCAL AREA SO FORECAST POPS ARE ONLY
20-30% (MAINLY N) AT THIS TIME. HIGHS TUESDAY ARE FORECAST TO BE IN
THE 70S AFTER MORNING LOWS IN THE 50S. HIGH PRESSURE BUILDS IN FROM
THE N TROUGH MIDWEEK...AS A LOW PRESSURE SYSTEM WITH LIMITED
MOISTURE APPROACHES FROM THE W. FORECAST HIGHS WEDNESDAY RANGE FROM
THE 60S ALONG THE COAST...TO THE LOW 70S INLAND.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
VFR CONDITIONS CONTINUE THROUGH THE FORECAST PERIOD. SURFACE HIGH
NOW LOCATED OFF THE MID ATLANTIC COAST WITH S WINDS AT 10 KTS OR
LESS. MOISTURE IN THE FORM OF HIGH AND MID LEVEL CLOUDS (4-5K FT
CU) WILL INCREASE AHEAD OF AN APPROACHING WARM FRONT TODAY. 00Z
MODEL GUIDANCE SUGGESTS AN ISOLATED SHOWER POSSIBLE BETWEEN 18Z-
00Z ACROSS SERN TAF SITES AS THIS BOUNDARY LIFTS NORTHWARD...BUT
CHANCE OF THIS AT ANY ONE SITE IS LOW SO PCPN WAS LEFT OUT OF
FORECAST FOR NOW. S-SW WINDS GUST 15-20 KT THIS AFTN AS PRESSURE
GRADIENT TIGHTENS BETWEEN THE DEPARTING HIGH AND APPROACHING LOW
TO THE WEST.
OUTLOOK...NEXT CHANCE FOR PRECIPITATION AND FLIGHT RESTRICTIONS
LOOKS TO BE FRI/FRI NIGHT (POTENTIALLY LINGERING THROUGH SAT
MORNING ACRS SE VA/NE NC) AS A COLD FRONT MOVES OFF THE COAST WITH
GRADUAL CLEARING OUT/DRIER AGAIN SATURDAY AFTN WITH DRY AND VFR
CONDS CONTINUING THROUGH MONDAY.
&&
.MARINE...
WINDS NOW SOUTH AROUND THE HIGH THAT HAS MOVED OFF THE COAST. SOME
CHANNELING POSSIBLE FROM TIME TO TIME TODAY AND TONIGHT...BUT THINK
WINDS WILL AVERAGE BELOW 20 KTS. WAVE GUIDANCE SUGGESTS SEAS OUT
NEAR BUOY 44009 REACH 5 FT FOR A FEW HOURS TONIGHT...BUT CONFIDENCE
IN THIS HAPPENING IS NOT THAT HIGH SO ELECTED TO HOLD OFF ON ANY
HEADLINE WITH THIS FORECAST PACKAGE.
OTW...NEXT CHANCE FOR ANY SCA HEADLINES WILL COME SAT MORNING AS
WINDS TURN NORTH BEHIND A COLD FRONTAL PASSAGE FRI NIGHT. CAA SURGE
APPEARS MINIMAL AT THIS POINT (15-20 KTS) ACROSS THE CHES BAY. HIGH
PRESSURE BUILDS OVER THE AREA SAT NIGHT AND SUN RESULTING IN BETTER
BOATING CONDITIONS.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SAM/TMG
NEAR TERM...SAM
SHORT TERM...SAM/TMG
LONG TERM...AJZ
AVIATION...MPR
MARINE...AJZ/MPR
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1158 PM EDT FRI APR 22 2016
.AVIATION...
DRY NORTHEAST FLOW SOUTH OF HIGH PRESSURE WILL MAINTAIN A STRETCH OF
CLEAR SKY THROUGH SATURDAY. NORTHEAST WINDS WILL HOLD FIRM THROUGH
THE DAYLIGHT PERIOD...GENERALLY REMAINING BELOW 10 KTS.
//DTW THRESHOLD PROBABILITIES...
* NONE
&&
.PREV DISCUSSION...ISSUED 404 PM EDT FRI APR 22 2016
DISCUSSION...
DESPITE A TRUE SPLIT FLOW CONFIGURATION OVER THE HEMISPHERE...THE
WEATHER FOR SOUTHEASTERN MICHIGAN WILL CONTINUE TO BE INFLUENCED IN
THE NEAR TERM (NEXT 6-8 HRS) BY A DAMPENING UPPER LEVEL TROUGH. THIS
TROUGH FEATURE IS THE OLD TEXAS UPPER LEVEL PV ANOMALY BECOMING
REACCLIMATED TO THE CONSOLIDATED POLAR WESTERLY BELT. ALL OF
THIS...WITH A PARTIAL CONNECTION BETWEEN PV RESERVOIR HAS BEEN SLOW
TO OCCUR. THUS...THE SLUGGISH SOUTHWARD PROGRESSION TO THE
FRONT/DEWPOINT GRADIENT SEEN OVER MONROE COUNTY TODAY. HIGHER THAN
EXPECTED DEWPOINTS IN THE MID 50S HAS RESULTED IN SBCAPES OF AROUND
500 J/KG. LATEST HIRES EXPLICIT CAM OUTPUT SUPPORTS A CONTINUED
POTENTIAL FOR SOME SHOWERS THROUGH 21Z BEFORE ENDING. RAP BASED SPC
MESOANALYSIS SHOWS THAT THE POCKET OF INSTABILITY HAS ESSENTIALLY
BEEN PUSHED SOUTH OF THE CWA BORDER ALREADY...AND LATEST RADAR
TRENDS SUPPORT THIS IDEA.
MAIN FORECAST ITEM FOR TONIGHT CENTERS ON HOW FAST CLOUDS WILL CLEAR
OUT. VISIBLE IMAGERY SUGGESTS A STRONG DEPENDENCE/FOOTING WITHIN
THE BOUNDARY LAYER. GIVEN DRY AIR ADVECTION IN THE MODELS...AND THIS
DEPENDENCE ON BOUNDARY LAYER CLOUD...THE IDEA IS THAT CLOUDS WILL
CLEAR OUT RAPIDLY THIS EVENING. THE CLEAR SKIES...LIGHT WINDS WITH
BUILDING SURFACE HIGH PRESSURE SUGGESTS COLD TEMPERATURES TONIGHT.
WENT VERY AGGRESSIVE AND WORKED IN THE COLDEST OF THE GUIDANCE
WITH LOWS SATURDAY MORNING OF LOWER TO MIDDLE 30S.
STABLE SURFACE HIGH PRESSURE AND CLEAR SKIES SATURDAY WILL PROVIDE
EFOR WONDERFUL WEATHER TO SOUTHEASTERN MICHIGAN. FORECASTED MIXING
HEIGHTS ARE NOT PARTICULARLY LOW...BUT UPSTREAM AIRMASS NORTH OF
LAKE HURON IS VERY DRY AND STABLE...(DEWPOINTS IN THE 20S AND
TEENS). PATTERN RECOGNITION AND TIME OF YEAR SUGGESTS
OVERACHIEVEMENT POTENTIAL FROM THE INSOLATION...BUT REALLY WENT
COOLER FOR SATURDAY. THE OUTGOING FORECAST WILL READ MIDDLE TO UPPER
50S MANY AREAS...LOWER TO MIDDLE 40S ALONG THE SHORELINE. NO REAL
WIND TO SPEAK OF...BUT THE DRY AIRMASS/EVAPORATIVE COOLING POTENTIAL
WILL MAKE THINGS COOLER THAN THEY WOULD OTHERWISE SEEM.
SUNDAY...THE MAIN QUESTION IS EXACTLY WHERE A STRETCHING DEFORMATION
AXIS OR THE NARROW THINNING WEAKNESS IN THE GEOPOTENTIAL HEIGHT
FIELD WILL RESIDE. FORECAST TRENDS THE PAST 24 HOURS HAS BEEN
POINTING TO NORTH OF THE CWA. CONFIDENCE AT THIS TIME IS REASONABLY
THAT IT WILL BE NORTH ENOUGH TO KEEP PRECIPITATION CHANCES OUT OF
AREAS SOUTH OF M46. FOR THE TRI CITIES...THE POTENTIAL FOR SOME RAIN
WILL INCREASE BY THE LATE AFTERNOON...BUT CANNOT GO MORE THAN A
CHANCE POP. LATEST FORECAST DATA SUGGESTS THE SATURATION TRAPPED
WITHIN THIS DEFORMATION ZONE WILL UNDERGO A SIGNIFICANT ONSLAUGHT OF
DRY AIR ADVECTION FROM BOTH THE NORTH AND SOUTH ON SUNDAY. IN
FACT...SOME PROGS SUGGEST THAT A SIGNIFICANT CENTROID OF THE UPPER
LEVEL RIDGE WILL ROLL THROUGH SOUTHEASTERN MICHIGAN EARLY SUNDAY.
DUE TO THE SPLIT FLOW...THIS AIRMASS WILL NOT BE A PARTICULARLY
WARM/HOT ONE...BUT WONDERFUL WEATHER IS NOW EXPECTED FOR A GOOD
PORTION OF THE CWA WITH TEMPERATURES REACHING THE UPPER 60S TO LOW
70S.
SURFACE LOW PRESSURE WILL TRACK ACROSS LOWER MICHIGAN ON
MONDAY...ALLOWING RAIN SHOWERS TO PERSIST MUCH OF THE DAY AND INTO
MONDAY NIGHT. THE LOW WILL SLOWLY TRACK EASTWARD ON TUESDAY MORNING
AS HIGH PRESSURE BUILDS INTO THE REGION OUT OF CANADA. THIS HIGH
WILL ALLOW DRY CONDITIONS AND COOLER AIR TO FILTER INTO SOUTHEAST
MICHIGAN RESULTING IN HIGH TEMPS ON TUESDAY TO ONLY BE IN THE UPPER
50S. THIS HIGH WILL LAST THROUGH WEDNESDAY EVENING. THE NEXT MAJOR
SYSTEM ARRIVES WEDNESDAY NIGHT AND INTO THURSDAY AS A WARM FRONT
PUSHES NORTHWARD INTO SOUTHEAST MICHIGAN. THE CENTER OF THE LOW
PRESSURE SYSTEM WILL THEN TRACK OVER LOWER MICHIGAN ON THURSDAY AND
THURSDAY EVENING KEEPING CONDITIONS ACROSS SOUTHEAST MICHIGAN WET
AND CLOUDY.
MARINE...
NORTHERLY FLOW OVER LAKE HURON BETWEEN 15 TO 20 KNOTS THIS AFTERNOON
WILL GRADUALLY EASE JUST A BIT TO AROUND 15 KNOTS TONIGHT...AND
BECOMING NORTHEAST IN PROCESS. THIS WILL ALLOW WAVES TO DIMINISH
FROM THE 3 TO 6 FOOT RANGE TO MORE LIKE 2 TO 4 FEET OVER THE
SOUTHERN LAKE HURON BASIN. HIGH PRESSURE BUILDING INTO THE CENTRAL
GREAT LAKES TOMORROW WILL LEAD TO FAVORABLE BOATING
CONDITIONS...WITH LIGHT WINDS AND LOW WAVES...ALONG WITH FULL
SUNSHINE. A DEVELOPING FRONTAL BOUNDARY FOR THE SECOND HALF OF THE
WEEKEND WILL LEAD TO STRENGTHENING EASTERLY WINDS IN EXCESS OF 20
KNOTS OVER NORTHERN LAKE HURON...ALONG WITH SHOWERS...WHICH WILL
SPREAD ACROSS THE ENTIRE MARINE WATERS AS WE HEAD INTO MONDAY.
HYDROLOGY...
A STRENGTHENING FRONTAL BOUNDARY ON SUNDAY WILL BRING THE NEXT
CHANCE OF SHOWERS TO THE AREA...BUT BULK OF THE RAINFALL IS EXPECTED
TO OCCUR OVER NORTHERN LOWER MICHIGAN. A LOW RIDING ALONG THE FRONT
ON MONDAY WILL ALLOW FOR SHOWERS TO SPREAD ACROSS ALL OF SOUTHEAST
MICHIGAN...WITH THE POTENTIAL FOR RAINFALL TOTALS IN EXCESS OF HALF
AN INCH.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....MR
DISCUSSION...CB
MARINE.......SF
HYDROLOGY....SF
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
718 PM EDT FRI APR 22 2016
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 309 PM EDT FRI APR 22 2016
WV IMAGERY AND RAP ANALYSIS INDICATED WNW MID/UPPER LEVEL FLOW INTO
THE NRN LAKES ON THE PERIPHERY OF A DEEP LOW INTO NRN HUDSON BAY.
LOW LEVEL CAA WITH NRLY WINDS KEPT LOW CLOUDS ACROSS MUCH OF THE
FCST AREA INTO EARLY AFTERNOON...BUT NOW BUILDING HIGH PRES FM NW OF
LAKE SUPERIOR HAS ALLOWED FOR INFLUX OF DRIER AIR AND ERODING CLOUD
COVER MID-LATE THIS AFTERNOON. MAX TEMPS TODAY HAVE RANGED FM THE
MID TO UPPER 30S ALONG LAKE SUPERIOR TO AROUND 50F CLOSER TO THE WI
BORDER.
TONIGHT...ALTHOUGH WINDS WILL DIMINISH WITH THE SFC HIGH PRES RIDGE
SLIDING OVER THE AREA...WAA MID CLOUDS FROM SRN MANITOBA AND NRN MN
ARE EXPECTED TO SPREAD IN FM THE W OVERNIGHT DUE TO INCREASING 295-
300K ISENTROPIC ASCENT WHICH SHOULD KEEP TEMPS FROM DROPPING OFF TOO
FAR. TEMPS MAY STILL FALL INTO THE MID 20S CENTRAL AND EAST BEFORE
THE CLOUDS MOVE IN. OTHERWISE...EXPECT MIN READINGS IN THE LOWER 30S
WEST.
SAT...A WNW FLOW ALOFT WILL DOMINATE THE UPPER GREAT LAKES BETWEEN
AN UPR RIDGE AXIS IN THE PLAINS AND AN UPR TROUGH OVER ERN CANADA.
MODELS SHOW MID/HIGH CLDS CONTINUING TO SPREAD INTO UPPER MI WITH
WAA TO THE NE OF SHARPENING FNT FM THE DAKOTAS INTO MN.
HOWEVER...THE MAJORITY OF MODELS INDICATE LINGERING LLVL DRY AIR
ASSOCIATED WITH SLOWLY DEPARTING SFC HIGH PRES WL KEEP THE CWA DRY.
ONLY THE 12Z GFS SHOWS RAIN REACHING INTO THE NW CWA WHERE MODELS
INDICATE PROXIMITY TO STRONGER H7 FGEN ALONG AND NE OF SHARPENING
FRONTAL BOUNDARY.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 434 PM EDT FRI APR 22 2016
BUILDING HEIGHTS OVER GREENLAND (500MB HEIGHTS UP TO 2.5 STANDARD
DEVIATIONS ABOVE CLIMATOLOGY) THRU EARLY NEXT WEEK WILL SUPPORT
TROFFING OVER SE CANADA AND FAIRLY COLD AIR FOR LATE APR ACROSS
ONTARIO AND QUEBEC. AS A RESULT...A RATHER SHARP BAROCLINIC ZONE
WILL SET UP ACROSS THE UPPER LAKES BTWN THE LATE SEASON COLD AIR
EXPANDING ACROSS SE CANADA AND WARM AIR SPREADING ACROSS THE PLAINS
AHEAD OF A SRN STREAM SHORTWAVE LIFTING OUT OF A MEAN TROF OVER THE
CNTRL/SRN ROCKIES. THIS BAROCLINIC ZONE WILL SET THE STAGE FOR
ACTIVE WEATHER AND POTENTIAL OF MDT TO EVEN HVY PCPN AMOUNTS IN THE
SUN/MON TIME FRAME. GIVEN THE PROXIMITY OF THE COLD AIR...IT`S NOT
OUT OF THE QUESTION THAT ACCUMULATING WET SNOW COULD ALSO OCCUR IN
SOME AREAS OF UPPER MI. LATER NEXT WEEK...THE HEIGHT ANOMALIES WILL
WEAKEN...BUT THE TROF WILL REMAIN IN SE CANADA...RESULTING IN A
CONTINUED BLO NORMAL TEMP REGIME LIKELY PERSISTING FOR UPPER MI THRU
THE ENTIRE WEEK. AFTER THE SUN/MON PCPN...ANOTHER OPPORTUNITY OF
PCPN MAY OCCUR WED/THU IF THE NEXT SHORTWAVE LIFTING OUT OF THE MEAN
ROCKIES TROF MOVES FAR ENOUGH NE TO AFFECT THE UPPER LAKES. DRY
WEATHER SHOULD THEN ROUND OUT THE WEEK. LOOKING FARTHER AHEAD...
NAEFS OUTLOOKS IN THE 8-14DAY PERIOD (APR30-MAY7) INDICATE TEMPS
OVERALL CLOSE TO NORMAL FOR UPPER MI.
BEGINNING SAT NIGHT...-RA WILL DEVELOP/SPREAD INTO THE FCST AREA
WITHIN SHARPENING BAROCLINIC ZONE...LOW-MID LEVEL FGEN...UPPER
DIVERGENCE IN RRQ OF 120KT UPPER JET ACROSS NRN ONTARIO/SRN QUEBEC
AND STRENGTHENING ISENTROPIC ASCENT. WILL CARRY HIGHER CATEGORICAL
POPS INTO ROUGHLY THE FAR HALF IN THE 06Z-12Z PERIOD.
SUN/MON...PCPN GENERATION IN THE BAROCLINIC ZONE WILL CONTINUE TO BE
MAINTAINED BY LOW-MID LEVEL FGEN AND THE RIGHT ENTRANCE OF UPPER JET
ACROSS NRN ONTARIO/SRN QUEBEC. IN ADDITION...SHORTWAVE ENERGY
EJECTING FROM THE CNTRL/SRN ROCKIES INTO THE UPPER MISSISSIPPI
VALLEY...THOUGH WEAKENING...WILL FURTHER AID THE PCPN. WITH
PRECIPITABLE WATER OF 0.75 TO A LITTLE OVER 1 INCH...ROUGHLY 200-
250PCT OF NORMAL...POTENTIAL WILL BE THERE FOR MDT TO EVEN LOCALLY
HVY PCPN AMOUNTS. THIS FCST WILL SHOW TOTAL QPF SAT NIGHT TO MON
EVENING RANGING FROM AROUND ONE-THIRD OF AN INCH OVER THE NRN
KEWEENAW PENINSULA TO AROUND 2 INCHES ALONG THE WI/MI BORDER INTO
SCNTRL UPPER MI. MODELS HAVE NOT BE VERY CONSISTENT ON THERMAL
FIELDS AND POTENTIAL FOR ACCUMULATING SNOW. ABOUT ALL THAT CAN BE
SAID AT THIS POINT IS THAT THERE IS SOME POTENTIAL FOR ACCUMULATING
WET/HVY SNOW OVER PARTS OF UPPER MI...MAINLY THE HIGHER TERRAIN OF
THE W HALF LATE SUN NIGHT/MON MORNING.
PCPN SHOULD DIMINISH/END W TO E MON NIGHT AS WEAKENING SHORTWAVE
ENERGY LIFTING INTO THE UPPER MISSISSIPPI VALLEY MON SHIFTS E ACROSS
THE GREAT LAKES REGION. WILL IGNORE THE CANADIAN MODEL WHICH IS AN
OUTLIER IN BEING MUCH SLOWER TO SHIFT THE SHORTWAVE E...RESULTING IN
PCPN (RAIN/SNOW) LINGERING INTO TUE AFTN.
SKIES WILL CLEAR OUT FOR TUE. IN FACT...WITH GFS FCST SOUNDINGS
SHOWING A DEEP DRY AIR MASS...SHOULD SEE ABUNDANT SUNSHINE. DESPITE
THE SUN...IT WILL BE CHILLY UNDER 850MB TEMPS OF -2 TO -4C AT
MIDDAY. IN ADDITION...CHILL WILL BE AIDED BY A GRADIENT NE WIND TO
START THE DAY AND THEN MESO HIGH DEVELOPING OVER LAKE SUPERIOR IN
THE AFTN MAINTAINING LAKE COOLING.
WED/THU...ATTENTION SHIFTS TO THE NEXT CLUSTER OF SHORTWAVE ENERGY
THAT SETTLED INTO THE MEAN CNTRL/SRN ROCKIES TROF MON/TUE. MUCH WILL
DEPEND ON THE STRENGTH OF THE CONTINUED SE CANADA TROF WHICH WILL BE
EVOLVING INTO A MID LEVEL LOW. IF ITS INFLUENCE REMAINS STRONGER
FARTHER S...THE EJECTING ENERGY WILL BE SUPPRESSED S OF THE AREA...
KEEPING UPPER MI UNDER DRY WEATHER...SIMILAR TO RECENT GFS RUNS AND
THE 12Z CANADIAN. IF THE TROF/CLOSED LOW IN SE CANADA IS
WEAKER/FARTHER N...THE EJECTING ENERGY WILL LIFT FARTHER TO THE NE
AND BRING MORE RAIN INTO UPPER MI...SIMILAR TO RECENT ECMWF RUNS.
HOWEVER...THE 12Z ECMWF HAS STARTED TO BACK AWAY FROM ITS MORE
AGGRESSIVE NE PUSH OF PCPN. FOR NOW...FCST WILL UTILIZE A CONSENSUS
APPROACH WHICH RESULTS IN MOSTLY SCHC POPS WED/THU.
DRY WEATHER WILL THEN ROUND OUT THE WEEK AS HIGH PRES BUILDS SE INTO
THE GREAT LAKES.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 717 PM EDT FRI APR 22 2016
HIGH PRES BUILDING INTO THE REGION WILL BRING VFR CONDITIONS FOR THE
ENTIRE FCST PERIOD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 309 PM EDT FRI APR 22 2016
HIGH PRES WILL MOVE ACROSS LAKE SUPERIOR TONIGHT WITH WINDS
DIMINISHING TO 15 KNOTS OE LESS INTO SAT. AS THE HIGH EXITS TO THE
EASTERN SEABOARD AND LOW PRESSURE DEVELOPS OVER THE PLAINS ON
SUNDAY, NORTHEAST WINDS WILL INCREASE TO 20-30 KTS SUNDAY INTO
MONDAY. THE STRONGEST WINDS WILL BE OVER WESTERN LAKE SUPERIOR WHERE
WINDS MAY APPROACH GALES AT TIMES. WINDS DIMINISH TO LESS THAN 20
KTS MONDAY NIGHT INTO WEDNESDAY AS HIGH PRESSURE MOVES BACK ACROSS
THE REGION.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...ROLFSON
AVIATION...07
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
707 PM EDT FRI APR 22 2016
.AVIATION...
EXTENSIVE MVFR STRATUS DECK POSITIONED ACROSS SE MICHIGAN WILL
SLOWLY DECREASE IN COVERAGE AS DRIER AIR WORKS IN. WITH THAT
SAID...IT REMAINS PLAUSIBLE THAT THE COOLER PREVAILING NORTH-
NORTHEAST FLOW OFF LAKE HURON RETAINS SOME COMPONENT OF LOW STRATUS
WELL INTO THE NIGHT. ONCE DRIER AIR TAKES A GREATER HOLD...LOOKING
AT AN EXTENDED STRETCH OF CLEAR SKY THROUGH SATURDAY.
FOR DTW...SATELLITE TRENDS POINT TO A SLOW CLEARING PROCESS EARLY
TONIGHT. CONTINUE TO FAVOR A CLEARING SKY CLOSER TO
MIDNIGHT. DIMINISHING NORTHEAST WITH LOSS OF HEATING THIS EVENING.
//DTW THRESHOLD PROBABILITIES...
* HIGH FOR CEILING AOB 5000 FT PRIOR TO MIDNIGHT...LOW IN TIMING OF
CLEARING THEREAFTER.
&&
.PREV DISCUSSION...ISSUED 404 PM EDT FRI APR 22 2016
DISCUSSION...
DESPITE A TRUE SPLIT FLOW CONFIGURATION OVER THE HEMISPHERE...THE
WEATHER FOR SOUTHEASTERN MICHIGAN WILL CONTINUE TO BE INFLUENCED IN
THE NEAR TERM (NEXT 6-8 HRS) BY A DAMPENING UPPER LEVEL TROUGH. THIS
TROUGH FEATURE IS THE OLD TEXAS UPPER LEVEL PV ANOMALY BECOMING
REACCLIMATED TO THE CONSOLIDATED POLAR WESTERLY BELT. ALL OF
THIS...WITH A PARTIAL CONNECTION BETWEEN PV RESERVOIR HAS BEEN SLOW
TO OCCUR. THUS...THE SLUGGISH SOUTHWARD PROGRESSION TO THE
FRONT/DEWPOINT GRADIENT SEEN OVER MONROE COUNTY TODAY. HIGHER THAN
EXPECTED DEWPOINTS IN THE MID 50S HAS RESULTED IN SBCAPES OF AROUND
500 J/KG. LATEST HIRES EXPLICIT CAM OUTPUT SUPPORTS A CONTINUED
POTENTIAL FOR SOME SHOWERS THROUGH 21Z BEFORE ENDING. RAP BASED SPC
MESOANALYSIS SHOWS THAT THE POCKET OF INSTABILITY HAS ESSENTIALLY
BEEN PUSHED SOUTH OF THE CWA BORDER ALREADY...AND LATEST RADAR
TRENDS SUPPORT THIS IDEA.
MAIN FORECAST ITEM FOR TONIGHT CENTERS ON HOW FAST CLOUDS WILL CLEAR
OUT. VISIBLE IMAGERY SUGGESTS A STRONG DEPENDENCE/FOOTING WITHIN
THE BOUNDARY LAYER. GIVEN DRY AIR ADVECTION IN THE MODELS...AND THIS
DEPENDENCE ON BOUNDARY LAYER CLOUD...THE IDEA IS THAT CLOUDS WILL
CLEAR OUT RAPIDLY THIS EVENING. THE CLEAR SKIES...LIGHT WINDS WITH
BUILDING SURFACE HIGH PRESSURE SUGGESTS COLD TEMPERATURES TONIGHT.
WENT VERY AGGRESSIVE AND WORKED IN THE COLDEST OF THE GUIDANCE
WITH LOWS SATURDAY MORNING OF LOWER TO MIDDLE 30S.
STABLE SURFACE HIGH PRESSURE AND CLEAR SKIES SATURDAY WILL PROVIDE
EFOR WONDERFUL WEATHER TO SOUTHEASTERN MICHIGAN. FORECASTED MIXING
HEIGHTS ARE NOT PARTICULARLY LOW...BUT UPSTREAM AIRMASS NORTH OF
LAKE HURON IS VERY DRY AND STABLE...(DEWPOINTS IN THE 20S AND
TEENS). PATTERN RECOGNITION AND TIME OF YEAR SUGGESTS
OVERACHIEVEMENT POTENTIAL FROM THE INSOLATION...BUT REALLY WENT
COOLER FOR SATURDAY. THE OUTGOING FORECAST WILL READ MIDDLE TO UPPER
50S MANY AREAS...LOWER TO MIDDLE 40S ALONG THE SHORELINE. NO REAL
WIND TO SPEAK OF...BUT THE DRY AIRMASS/EVAPORATIVE COOLING POTENTIAL
WILL MAKE THINGS COOLER THAN THEY WOULD OTHERWISE SEEM.
SUNDAY...THE MAIN QUESTION IS EXACTLY WHERE A STRETCHING DEFORMATION
AXIS OR THE NARROW THINNING WEAKNESS IN THE GEOPOTENTIAL HEIGHT
FIELD WILL RESIDE. FORECAST TRENDS THE PAST 24 HOURS HAS BEEN
POINTING TO NORTH OF THE CWA. CONFIDENCE AT THIS TIME IS REASONABLY
THAT IT WILL BE NORTH ENOUGH TO KEEP PRECIPITATION CHANCES OUT OF
AREAS SOUTH OF M46. FOR THE TRI CITIES...THE POTENTIAL FOR SOME RAIN
WILL INCREASE BY THE LATE AFTERNOON...BUT CANNOT GO MORE THAN A
CHANCE POP. LATEST FORECAST DATA SUGGESTS THE SATURATION TRAPPED
WITHIN THIS DEFORMATION ZONE WILL UNDERGO A SIGNIFICANT ONSLAUGHT OF
DRY AIR ADVECTION FROM BOTH THE NORTH AND SOUTH ON SUNDAY. IN
FACT...SOME PROGS SUGGEST THAT A SIGNIFICANT CENTROID OF THE UPPER
LEVEL RIDGE WILL ROLL THROUGH SOUTHEASTERN MICHIGAN EARLY SUNDAY.
DUE TO THE SPLIT FLOW...THIS AIRMASS WILL NOT BE A PARTICULARLY
WARM/HOT ONE...BUT WONDERFUL WEATHER IS NOW EXPECTED FOR A GOOD
PORTION OF THE CWA WITH TEMPERATURES REACHING THE UPPER 60S TO LOW
70S.
SURFACE LOW PRESSURE WILL TRACK ACROSS LOWER MICHIGAN ON
MONDAY...ALLOWING RAIN SHOWERS TO PERSIST MUCH OF THE DAY AND INTO
MONDAY NIGHT. THE LOW WILL SLOWLY TRACK EASTWARD ON TUESDAY MORNING
AS HIGH PRESSURE BUILDS INTO THE REGION OUT OF CANADA. THIS HIGH
WILL ALLOW DRY CONDITIONS AND COOLER AIR TO FILTER INTO SOUTHEAST
MICHIGAN RESULTING IN HIGH TEMPS ON TUESDAY TO ONLY BE IN THE UPPER
50S. THIS HIGH WILL LAST THROUGH WEDNESDAY EVENING. THE NEXT MAJOR
SYSTEM ARRIVES WEDNESDAY NIGHT AND INTO THURSDAY AS A WARM FRONT
PUSHES NORTHWARD INTO SOUTHEAST MICHIGAN. THE CENTER OF THE LOW
PRESSURE SYSTEM WILL THEN TRACK OVER LOWER MICHIGAN ON THURSDAY AND
THURSDAY EVENING KEEPING CONDITIONS ACROSS SOUTHEAST MICHIGAN WET
AND CLOUDY.
MARINE...
NORTHERLY FLOW OVER LAKE HURON BETWEEN 15 TO 20 KNOTS THIS AFTERNOON
WILL GRADUALLY EASE JUST A BIT TO AROUND 15 KNOTS TONIGHT...AND
BECOMING NORTHEAST IN PROCESS. THIS WILL ALLOW WAVES TO DIMINISH
FROM THE 3 TO 6 FOOT RANGE TO MORE LIKE 2 TO 4 FEET OVER THE
SOUTHERN LAKE HURON BASIN. HIGH PRESSURE BUILDING INTO THE CENTRAL
GREAT LAKES TOMORROW WILL LEAD TO FAVORABLE BOATING
CONDITIONS...WITH LIGHT WINDS AND LOW WAVES...ALONG WITH FULL
SUNSHINE. A DEVELOPING FRONTAL BOUNDARY FOR THE SECOND HALF OF THE
WEEKEND WILL LEAD TO STRENGTHENING EASTERLY WINDS IN EXCESS OF 20
KNOTS OVER NORTHERN LAKE HURON...ALONG WITH SHOWERS...WHICH WILL
SPREAD ACROSS THE ENTIRE MARINE WATERS AS WE HEAD INTO MONDAY.
HYDROLOGY...
A STRENGTHENING FRONTAL BOUNDARY ON SUNDAY WILL BRING THE NEXT
CHANCE OF SHOWERS TO THE AREA...BUT BULK OF THE RAINFALL IS EXPECTED
TO OCCUR OVER NORTHERN LOWER MICHIGAN. A LOW RIDING ALONG THE FRONT
ON MONDAY WILL ALLOW FOR SHOWERS TO SPREAD ACROSS ALL OF SOUTHEAST
MICHIGAN...WITH THE POTENTIAL FOR RAINFALL TOTALS IN EXCESS OF HALF
AN INCH.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....MR
DISCUSSION...CB
MARINE.......SF
HYDROLOGY....SF
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
327 PM EDT THU APR 21 2016
LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM/MARINE
.SYNOPSIS...
ISSUED AT 327 PM EDT THU APR 21 2016
AFTER SHOWERS AND ISOLATED THUNDERSTORMS EXIT THE AREA EARLY
TONIGHT...CHANCES FOR SHOWERS AND THUNDERSTORMS RETURN SUNDAY AND
CONTINUE WELL INTO NEXT WEEK. SUNDAY WILL BE WARM WITH TEMPERATURES
APPROACHING 70 IN SOME SPOTS. AFTERWARDS...HIGHS WILL BE NEAR
OR SLIGHTLY ABOVE NORMAL WITH HIGHS IN THE LOWER TO MID 60S.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 327 PM EDT THU APR 21 2016
EXPERIMENTAL HRRR GUIDANCE IS LOOKING ON TRACK AS CLEARING HAS
SPREAD INTO EXTREME SOUTHWEST LOWER MI AND A THUNDERSTORM ALREADY
HAS DEVELOPED OVER NORTHWEST INDIANA. BASED ON EXPECTED MOVEMENT
TO THE NORTHEAST...WE STILL EXPECT THE BEST CHANCES FOR THUNDERSTORMS
WILL BE SOUTH OF I-96 AND EAST OF KALAMAZOO MAINLY BEFORE MIDNIGHT.
AFTER THIS EXPECT AT LEAST SOME PATCHY FOG NEAR THE I-94 CORRIDOR
THE REST OF THE NIGHT.
AFTER TONIGHT...FORECAST CONCERNS ARE MINIMAL WITH RAIN SHOWERS
APPROACHING FROM THE NORTHWEST ON SATURDAY NIGHT.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 327 PM EDT THU APR 21 2016
A STATIONARY FRONT IS STILL EXPECTED TO SLIDE SLOWLY SOUTH THROUGH
THE CWA SUNDAY INTO MONDAY NIGHT. THIS FRONT WILL HAVE A SOLID GULF
MOISTURE CONNECTION AND THE OVER RIDING ACROSS THIS FRONT SHOULD
PRODUCE A FAIR AMOUNT OF RAIN. IT APPEARS MOST AREAS SHOULD GET A
AROUND AN INCH OF RAIN. THE STEADIEST RAINS SHOULD OCCUR ACROSS
CENTRAL LOWER WHERE THE BEST LIFT PERSISTS ACROSS THE FRONT...AND
OVER AN INCH OF RAIN CERTAINLY SEEMS POSSIBLE HERE. A BIT LIGHTER
RAINS ARE EXPECTED TOWARD I-94. A FEW CLAPS OF THUNDER WILL BE
POSSIBLE BUT NO SEVERE WEATHER IS EXPECTED AT THIS TIME. THE AREA
SHOULD DRY OUT INTO TUESDAY AS A WAVE OF LOW PRESSURE SLIDES ALONG
THE FRONT AND HEADS EAST.
HOWEVER THE DRY SPELL APPEARS BRIEF AS MORE RAIN CHANCES RETURN FOR
WEDNESDAY AND THURSDAY WITH ANOTHER WAVE OF LOW PRESSURE MOVING
ACROSS THE OHIO VALLEY. SIMILAR PATTERN WITH A GOOD CHANCE OF
RAIN...BUT MINIMAL CHANCES FOR SEVERE STORMS.
WE WILL REMAIN MILD UNTIL THE FRONT COMES THROUGH...WITH A COOLER
PERIOD FOR TUESDAY AND WEDNESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 158 PM EDT THU APR 21 2016
THE REGION WAS UNDER A MIX OF IFR AND MVFR EARLY THIS AFTERNOON.
EXPECTING A TREND TO MORE MVFR TOWARD 20Z AS SLIGHTLY DRIER AIR
MOVES IN. HOWEVER WITH THIS DRIER AIR...AND PERHAPS POCKETS OF
SUNSHINE...WE WILL BECOME MORE UNSTABLE AND WIDELY SCATTERED
THUNDERSTORMS WILL BECOME POSSIBLE. I HAVE ADDED VCTS ACROSS ALL
THE TAF SITES FROM MID AFTERNOON INTO THIS EVENING.
SOME PARTIAL CLEARING IS EXPECTED AS A COLD FRONT COMES THROUGH
AROUND 06Z. HOWEVER WITH THIS CLEARING WILL COME FOG DEVELOPMENT.
EXPECT ANOTHER PERIOD OF IFR AFTER 06Z AND PROBABLY LASTING UNTIL
AFTER DAYBREAK. THE HIGHEST CHANCE OF IMPACT FROM THIS FOG WILL BE
ACROSS I-94...AND SOMEWHAT MORE QUESTIONABLE TOWARD I-96.
&&
.MARINE...
ISSUED AT 327 PM EDT THU APR 21 2016
FOG HAS BECOME CONSIDERABLY THICKER IN THE LAST COUPLE HOURS SO IN
COORDINATION WITH IWX HAVE HOISTED A MARINE DENSE FOG ADVISORY.
FOG WILL GET SWEPT OUT OVERNIGHT WHEN STRONG NORTH WINDS SPREAD
SOUTH ACROSS LAKE MICHIGAN. RAPIDLY GROWING WAVES WITH THE
STRONGER WINDS AND A VERY FAVORABLE LONG FETCH WILL GIVE US SMALL
CRAFT ADVISORY CONDITIONS QUICKLY FRIDAY MORNING SO HAVE ALSO
ISSUED A SMALL CRAFT ADVISORY WITH THIS PACKAGE.
&&
.HYDROLOGY...
ISSUED AT 158 PM EDT THU APR 21 2016
RAINFALL LAST NIGHT AND TODAY HAS BEEN LIGHT IN NATURE... WITH FEW
TOTALS EXCEEDING A QUARTER INCH. LEVELS ON MAIN STEM RIVERS CONTINUE
A GRADUAL DECLINE... BUT WE HAVE BEEN SEEING RISES ON SMALLER RIVERS
AND CREEKS. NO FLOODING IN ANTICIPATED TODAY OR TOMORROW.
AFTER A QUIET FRIDAY AND SATURDAY... SUNDAY THROUGH THE REST OF NEXT
WEEK LOOKS FAIRLY ACTIVE. A WIDESPREAD INCH OF RAINFALL IS CERTAINLY
POSSIBLE. RIVERS REMAIN ELEVATED... SO WE COULD SEE SOME RISE ABOVE
BANKFULL AND PRODUCE MINOR FLOODING IN LOWLAND AREAS NEXT WEEK.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...DENSE FOG ADVISORY UNTIL 2 AM EDT FRIDAY FOR LMZ844>849.
SMALL CRAFT ADVISORY FROM 8 AM FRIDAY TO 2 AM EDT SATURDAY FOR
LMZ844>849.
&&
$$
SYNOPSIS...TJT
SHORT TERM...TJT
LONG TERM...JK
AVIATION...JK
HYDROLOGY...EBW
MARINE...TJT
AREA FORECAST DISCUSSION
NWS JACKSON MS
913 PM CDT FRI APR 22 2016
.DISCUSSION...NO REAL CHANGES TO THE FORECAST. UPDATED TO REMOVE THE
EVENING WORDING. THE RAIN HAS ENDED ACROSS THE CWA AND SKIES WERE
GENERALLY CLEAR. TEMPERATURES DID NOT CHANGE MUCH BEHIND THE
FRONT...BUT DEWPOINTS WERE DOWN. TWEAKED THE HOURLY VALUES BUT LEFT
THE LOWS. RUC AND HI RES SUGGEST VALUES MAY BE A DEGREE OR TWO
WARMER. THE DIFFERENCE WAS NOT SIGNIFICANT ENOUGH TO CHANGE. NO OTHER
CHANGES TO THE FORECAST.
&&
.AVIATION...VFR CONDITIONS WILL PREVAIL ACROSS THE AREA THROUGH THE
FORECAST PERIOD. THE RAIN HAS MOVED OUT. THERE MAY BE SOME PATCHY FOG
BRIEFLY AROUND HBG EARLY IN THE MORNING.
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 55 81 55 82 / 0 0 0 0
MERIDIAN 55 80 53 82 / 0 0 0 0
VICKSBURG 56 81 54 82 / 0 0 0 0
HATTIESBURG 56 83 56 82 / 5 0 0 0
NATCHEZ 56 80 57 82 / 0 0 0 0
GREENVILLE 56 80 55 81 / 0 0 0 0
GREENWOOD 54 81 54 82 / 0 0 0 0
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
07/BB
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
845 PM MDT FRI APR 22 2016
.UPDATE...
MADE A FEW ADJUSTMENTS TO THE FORECAST FOR THE UPDATE THIS
EVENING. A FEW SHOWERS/THUNDERSTORMS WERE MOVING N FROM NW WY
TOWARD THE FORECAST AREA THIS EVENING WHILE WEAKENING. VIRGA HAS
ALSO BEEN REPORTED AROUND THE AREA. UPPER LOW ALONG THE OR/CA
COAST MOVES INLAND OVERNIGHT AND SENDS VORTICITY THROUGH THE
REGION AND BRINGS UPPER DIFLUENCE AS WELL. THESE FACTORS...ALONG
WITH SOME CAPE AND STEEP LAPSE RATES WERE CAUSING THE
PRECIPITATION OVER WY. THE WANING OF DAYTIME HEATING WAS CAUSING
LAPSE RATES TO DECREASE AND CAPES WERE FOCUSED N OF THE FORECAST
AREA. THERE WAS ALSO A LARGE TEMPERATURE/DEWPOINT SPREAD ACROSS
THE AREA THAT WAS GRADUALLY SHRINKING WITH TIME. THE HRRR AND WRF
HAVE BEEN CONSISTENTLY TRYING TO BRING LIGHT QPF INTO THE AREA
OVERNIGHT. GIVEN THE ABOVE...CANNOT SEE THE PRECIPITATION BEING
ANY HEAVIER THAN SPRINKLES...SO HAVE ADDED THESE TO THE FORECAST.
OTHERWISE...HAVE RAISED LOWS MAINLY INTO THE 50S GIVEN 02Z
READINGS IN THE 60S AND 70S AND A DECENT AMOUNT OF CLOUD COVER
OVER THE AREA.
REGARDING THE POTENTIAL FOR STRONG STORMS ON SAT...THE SREF SHOWED
500-1000 J/KG OF CAPE FROM THE SE TO CENTRAL ZONES WITH THE
STRONGEST CAPES OVER SE MT. HOWEVER SHEAR WAS LACKING. THUS WOULD
EXPECT A FEW STRONG PULSE STORMS...MAINLY OVER SE MT WITH HAIL AND
GUSTY WINDS POSSIBLE. ARTHUR
&&
.SHORT TERM...VALID FOR SAT AND SUN...
THIS WILL BE THE LAST NICE DAY FOR AT LEAST THE NEXT 7 DAYS.
STRONG UPPER RIDGE OF HIGH PRESSURE WILL CONTINUE TO BRING MOSTLY
SUNNY SKIES TO THE FORECAST AREA FOR THE REMAINDER OF THE
AFTERNOON. A LARGE UPPER LOW AND TROUGH CURRENTLY MOVING ONTO THE
NORTHERN CALIFORNIA/OREGON COAST IS PROVIDING A SOUTHERLY FLOW
ALOFT. SATELLITE SHOWING PLENTY OF MID AND HIGH LEVEL CLOUDS
MOVING NORTH TO SOUTH OUT OF THE GREAT BASIN AREA WITH SOME OF
THESE REACHING OUR CENTRAL AND WESTERN ZONES. HOWEVER...CONDITIONS
ARE EXPECTED TO REMAIN DRY FOR THE REMAINDER OF THE AFTERNOON AND
EVENING. AS THE UPPER LOW MOVES TOWARD THE GREAT BASIN AREA THIS
EVENING...A BIT BETTER UPPER LEVEL DIVERGENCE APPROACHES OUR WESTERN
AREAS SO AN ISOLATED THUNDERSTORM WILL BE POSSIBLE FOR THE
BEARTOOTH/ABSAROKA MOUNTAINS THIS EVENING.
THE UPPER LOW MOVES ACROSS IDAHO AND NORTHERN WYOMING DURING THE
DAY SATURDAY. AT THE SAME TIME...A SURFACE LOW DEVELOPS OVER
CENTRAL MONTANA AND MOVES SOUTHEAST INTO SOUTHEAST MONTANA DURING
THE DAY. RAIN CHANCES WILL INCREASE DURING THE EARLY MORNING HOURS
AND SPREAD EAST DURING THE DAY. AS THE LOW MOVES SOUTHEAST IT WILL
SLIDE A COLD FRONT ACROSS THE FORECAST AREA. THE FRONT IS EXPECTED
TO MOVE ACROSS THE WESTERN AREAS DURING THE MORNING AND THE FAR
SOUTHEAST CORNER OF THE STATE BY EARLY EVENING. TEMPERATURES WILL
VARY WIDELY WITH 60S WEST TO 70S EAST. BEST CHANCES FOR ANY STRONG
TO SEVERE THUNDERSTORM WILL BE ACROSS THE FAR EAST IN THE WARM
SECTOR AND WHERE DYNAMICS WILL BE BEST.
A BRISK NORTH/NORTHEAST WIND ALONG WITH NUMEROUS SHOWERS TO
POSSIBLY A GENERAL RAIN WILL BE LIKELY FOR SUNDAY INTO SUNDAY
NIGHT. TEMPERATURES WILL BE MUCH COOLER SUNDAY WITH 40S COMMONWITH
EVEN A RAIN/SNOW MIX POSSIBLE AT TIMES SUNDAY. THE PRECIP MAY
BECOME ALL SNOW SUNDAY NIGHT AS 850MB TEMPERATURES FALL BELOW
FREEZING ACROSS PORTIONS OF OUR CENTRAL AND EASTERN AREAS. AT THIS
TIME...WE ARE NOT LOOKING FOR ANY ACCUMULATIONS OTHER THAN
POSSIBLY THE GRASSY AREAS...AS WELL AS AREA MOUNTAINS. THOSE WITH
OUTDOOR INTERESTS SHOULD KEEP POSTED TO OUR LATEST FORECASTS AS
DETAILS WILL BE REFINED OVER THE NEXT 24 HOURS. HOOLEY
.LONG TERM...VALID FOR MON...TUE...WED...THU...FRI...
MADE ONLY MINOR CHANGES TO INHERITED EXTENDED FORECAST...WITH
PATTERN CONTINUING TO BE WET AND UNSEASONABLY COOL THROUGH THE
PERIOD.
ANOTHER WAVE MOVES INTO THE REGION MONDAY...AS THE WEEKEND SYSTEM
EXITS EASTWARD. THIS TROF WILL SPREAD CHANCES ACROSS REGION THROUGH
WEDNESDAY. MODELS VARY A BIT ON TRACK...WITH ECMWF TAKING A MORE
SOUTHERN TACK...BUT SHOULD STILL SEE WIDESPREAD PRECIP. PRECIP
WOULD BE MAINLY RAIN...BUT AM CONCERNED ABOUT CONSIDERABLE SNOW
ACCUMULATION IN SOUTHERN CARTER COUNTY ONCE AGAIN BASED ON COOL
TEMPS OVER 36HR STRETCH FROM MONDAY NIGHT THROUGH TUESDAY
NIGHT. THURSDAY LOOKS DRIER...WITH SOME SHOWER POTENTIAL OVER THE
HIGH TERRAIN...AHEAD OF THE NEXT APPROACHING PACIFIC TROF. MODELS
DIVERGE AT THIS POINT...BUT GENERALLY INDICATE THE NEXT PACIFIC
TROF INTO THE REGION AS EARLY AS THURSDAY NIGHT...AND AS LATE AS
FRIDAY NIGHT. HAVE CARRIED SLIGHT POPS THROUGH THIS PERIOD AT
THIS TIME. GILSTAD
&&
.AVIATION...
VFR FLIGHT CONDITIONS WILL CONTINUE ACROSS THE REGION TONIGHT. AN
ISOLATED LIGHT SHOWER...OR SPRINKLE...IS POSSIBLE FROM BILLINGS
WESTWARD. THIS LIGHT ACTIVITY COULD PRODUCE A BRIEF WIND GUST TO
30KTS UNTIL AROUND MIDNIGHT. SHOWER AND THUNDERSTORM POTENTIAL
WILL INCREASE SATURDAY. TWH
&&
.PRELIMINARY POINT TEMP/POPS...
SAT SUN MON TUE WED THU FRI
-----------------------------------------------------------
BIL 056/071 044/048 034/044 035/041 034/051 034/056 036/055
16/T 78/R 65/W 56/O 54/W 21/B 23/W
LVM 049/063 040/056 035/047 032/043 032/051 030/055 035/055
08/T 87/R 55/W 55/O 43/W 32/W 33/W
HDN 054/075 042/045 034/046 034/043 034/052 032/057 034/056
16/T 79/R 64/W 56/R 64/W 21/B 22/W
MLS 055/076 041/043 032/045 035/043 035/052 034/056 036/056
12/T 79/O 64/W 46/R 43/W 21/B 22/W
4BQ 054/081 043/046 033/044 034/041 033/048 030/053 035/052
02/T 79/R 64/W 57/O 54/W 21/B 23/W
BHK 051/076 040/044 029/043 033/043 032/048 030/052 034/051
12/T 69/R 73/W 45/R 54/W 21/B 22/W
SHR 055/075 041/046 032/047 034/043 032/048 030/052 032/055
03/T 79/R 54/W 57/R 64/W 22/W 23/W
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
334 PM CDT THU APR 21 2016
.SYNOPSIS...
ISSUED AT 333 PM CDT THU APR 21 2016
H5 ANALYSIS FROM EARLIER THIS MORNING HAD A CLOSED LOW
OVER WESTERN IOWA WITH A TROUGH OF LOW PRESSURE EXTENDING SOUTH INTO
THE ARKLATEX. HT FALLS OF 50 TO 70 METERS WERE NOTED FROM THE MID
MISSISSIPPI VALLEY NORTHWARD TO THE ARROWHEAD OF MINNESOTA. WEST OF
THE TROUGH AND CLOSED LOW...WAS A RIDGE OF HIGH PRESSURE WHICH
EXTENDED FROM THE FOUR CORNERS...NORTH TO NORTHERN MONTANA. WEST OF
THE RIDGE...A TROUGH OF LOW PRESSURE WAS PRESENT FROM THE
ALEUTIANS...SOUTH INTO THE EASTERN PACIFIC...AND WAS ROUGHLY 500
MILES WEST OF THE OREGON AND WASHINGTON COASTS. AT THE SURFACE...LOW
PRESSURE WAS LOCATED OVER CENTRAL IOWA WITH HIGH PRESSURE ANCHORED
ACROSS THE FRONT RANGE OF COLORADO AND WYOMING. ACROSS WESTERN AND
NORTH CENTRAL NEBRASKA...WINDS WERE NORTHERLY BETWEEN THESE TWO
SURFACE FEATURES...AND WERE BREEZY THIS AFTERNOON WITH SPEEDS OF 15
TO 25 MPH. UNDER PARTLY CLOUDY SKIES...TEMPERATURES WERE IN THE
UPPER 60S TO AROUND 70.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 333 PM CDT THU APR 21 2016
MAIN FORECAST CONCERNS ARE WIND AND TEMPERATURES. THE UPPER LOW
CONTINUES ITS SLOW EASTWARD TREK AND GETS ABSORBED WITH THE OVERALL
FLOW OVER THE GREAT LAKES. H5 RIDGE BUILDS OVER THE GREAT PLAINS
WHILE A SURFACE TROUGH APPROACHES THE PANHANDLE LATE FRIDAY.
THIS EVENING AND TONIGHT... EFFICIENT MIXING TO NEAR 750HPA AS
INDICATED BY RAP AND HRRR SOUNDINGS AND NEARLY UNIDIRECTIONAL FLOW
CREATING GUSTS TO 25MPH FOR MUCH OF THE AREA. SOUNDINGS ALSO
INDICATE LOW LEVEL LIFT... WHICH IS CONFIRMED BY A GROWING CUMULUS
FIELD OVER WESTERN NEBRASKA. LEFT PRECIP MENTION OUT AS ABUNDANT DRY
AIR EXISTS IN THE MID LEVELS AND SURFACE DEW POINT DEPRESSIONS REACH
30F WEST TO 20F EAST. CLOUDS WILL CLEAR TONIGHT WITH THE LOSS OF
DIURNAL HEATING AND WINDS RELAX WITH BOUNDARY LAYER DECOUPLING.
MADE LITTLE CHANGE TO MIN TEMPS AS MID/UPPER 30S SEEMED REASONABLE
GIVEN CLEAR SKIES... LIGHT WINDS... AND NEGLIGIBLE TEMP ADVECTION AT
H85.
FRIDAY... CONTINUED THE TREND OF FOLLOWING WARMER GUIDANCE OR GOING
SLIGHTLY ABOVE FOR MAX TEMPS. RETURN FLOW SWITCHES LOW LEVEL WINDS
TO SOUTHERLY... AND MODELS IN AGREEMENT WITH APPRECIABLE WAA. H85
TEMPS RANGE FROM NEAR 20C PANHANDLE TO 10C NORTH CENTRAL... ABOUT 5
TO 10C WARMER THAN THURSDAY. LOW LEVEL WINDS STRENGTHEN THROUGHOUT
THE DAY AS THE PRESSURE GRADIENT INCREASES AHEAD OF THE TROUGH. NAM
SHOWING AROUND 1MB/HR FALLS DURING THE AFTERNOON. COUPLED WITH
SUBSIDENCE AND MIXING TO NEAR 800HPA WHERE H85 WINDS APPROACH
30KTS... GUSTS MAY REACH 25 TO 30MPH AT THE SURFACE. DESPITE WARM
TEMPERATURES AND BREEZY WINDS... FIRE WEATHER DOES NOT APPEAR TO BE
A SIGNIFICANT ISSUE AT THIS TIME. NAM...GFS...AND EURO KEEP SFC DEW
POINTS IN THE 40S DURING THE AFTERNOON... AND MIXING RATIOS INCREASE
1-2G/KG SINCE THURSDAY. MINIMUM RH VALUES STAY ABOVE 25 PERCENT
PANHANDLE AND 30 PERCENT EAST.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 333 PM CDT THU APR 21 2016
MID RANGE...FRIDAY NIGHT THROUGH SUNDAY...A TROUGH OF
LOW PRESSURE ALOFT WILL COME ONSHORE ACROSS NRN CALIFORNIA/OREGON
LATE FRIDAY. THIS FEATURE WILL TRACK EAST INTO WYOMING OVER THE NEXT
24 HOURS...MAKING IT AS FAR EAST AS NWRN WYOMING BY 00Z SUNDAY.
DURING THIS PERIOD...A STRONG LEE SIDE SFC CYCLONE WILL DEVELOP OVER
EASTERN WYOMING AND NERN COLORADO. EAST OF THIS FEATURE...SRLY WINDS
WILL INCREASE FRIDAY AFTERNOON INTO FRIDAY NIGHT. SRLY FLOW WILL
PUSH LOW LEVEL MOISTURE NWD DURING THE NIGHT AND THIS COUPLED WITH
THE SRLY WINDS...WILL MAKE FOR MILD TEMPS FRIDAY NIGHT. FCST LOWS
WILL BE IN THE UPPER 40S TO AROUND 50...SOME 10 TO 15 DEGREES ABOVE
NORMAL. ON SATURDAY...STRONG LOW LEVEL WARM AIR ADVECTION WILL
CONTINUE WITH H85 TEMPS REACHING 25C IN THE WEST BY 00Z SUN. THE
LATEST GUIDANCE REFLECTED THESE WARMER TEMPS SHOWN IN THE GRAPHICAL
NAM AND GFS FCST MODELS FROM THIS MORNING...AND HAVE TRENDED UP
HIGHS FOR SAT AFTN. THIS RESULTED IN HIGHS IN THE LOWER 80S ACROSS
THE BOARD. WE EVEN MAY SEE SOME MIDDLE 80S IN THE NORTHWEST WHERE
DRIER AIR IS EXPECTED SAT AFTN. ON SATURDAY EVENING...A PACIFIC COLD
FRONT WILL APPROACH THE PANHANDLE SAT EVENING...AND A LEAD
DISTURBANCE WILL APPROACH SWRN NEBRASKA FROM NERN COLORADO.
THUNDERSTORM CHANCES WILL INCREASE DURING THE EVENING HOURS WITH THE
BEST CHANCES IN THE SOUTHWEST IN PROXIMITY TO THE UPPER LEVEL
WAVE...AND IN THE NORTHWESTERN CWA INVOF THE FRONT AND CLOSER
PROXIMITY TO THE H5 LOW. AS FOR THE THREAT FOR SEVERE STORMS...WAS
CONCERNED SOMEWHAT ABOUT THE 2000 J/KG CAPES DEPICTED IN THE 12Z
NAM SOLN THIS MORNING...ACROSS CENTRAL PORTIONS OF THE CWA.
HOWEVER...BULK SHEAR IS ONLY 15 TO 20 KTS SAT AFTN/EVE...SO THE
SEVERE THREAT APPEARS MINIMAL ATTM. ON SUNDAY...THE UPPER LEVEL LOW
WILL TRACK ALONG THE NEBR/SD BORDER. ATTM...THE MAIN THREAT FOR PCPN
WILL CONTINUE OVER NRN NEBRASKA WITH MAINLY DRY CONDS IN THE SOUTH.
IT WILL BE WINDY WITH DECENT NORTHWESTERLY WINDS BEHIND THE COLD
FRONT SUNDAY. TEMPERATURES WILL RANGE FROM AROUND 60 IN THE WEST TO
THE MID 70S IN THE FAR EAST.
LONG RANGE...SUNDAY NIGHT THROUGH THURSDAY...AN ACTIVE SWRLY FLOW
PATTERN WILL CONTINUE INTO NEXT WEEK. THE FIRST OF TWO UPPER LEVEL
LOWS WILL APPROACH THE FORECAST AREA MONDAY NIGHT WITH LIKELY PCPN
EXPECTED FOR TUESDAY INTO TUESDAY NIGHT. PCPN WILL LINGER IN THE
NORTH FOR WEDNESDAY...WITH DRY CONDS EXPECTED WEDS NIGHT INTO
THURSDAY. A SECOND SYSTEM WILL APPROACH THE REGION LATE THURSDAY
WITH ANOTHER ROUND OF PCPN ON TAP FOR FRIDAY INTO SATURDAY NEXT
WEEK. TEMPERATURES WILL BE COOL WITH HIGHS IN THE 50S WITH SOME 40S
POSSIBLE IN NRN NEBRASKA TUES/WEDS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1215 PM CDT THU APR 21 2016
VFR CONDITIONS WILL CONTINUE ACROSS WESTERN NEBRASKA THROUGH
FRIDAY AFTERNOON. GUSTY NORTH WINDS THIS AFTERNOON WILL DIMINISH
AROUND SUNSET AND TRANSITION TO SOUTHERLY BY FRIDAY MORNING.
&&
.HYDROLOGY...
ISSUED AT 333 PM CDT THU APR 21 2016
RISES ON THE SOUTH PLATTE RIVER EXPECTED TO CONTINUE
OVER THE NEXT SEVERAL DAYS. UPSTREAM GAUGE AT JULESBURG STILL
SHOWING A SLOW RISE WITH AN EXPECTED CREST AT ROSCOE OF AROUND 7.3
FEET LATE FRIDAY/EARLY SATURDAY. ISSUED RVS THIS MORNING WITH
UPDATED FORECAST FROM MBRFC. SLIGHT UPTICK OBSERVED AT NORTH PLATTE
BUT STILL 1.5 FEET BELOW ACTION STAGE.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BUTTLER
SHORT TERM...SNIVELY
LONG TERM...BUTTLER
AVIATION...SNIVELY
HYDROLOGY...SNIVELY
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1140 PM CDT WED APR 20 2016
.SYNOPSIS...
ISSUED AT 405 PM CDT WED APR 20 2016
H5 ANALYSIS THIS MORNING HAD A CLOSED LOW OVER NORTH PLATTE WITH
RIDGING OFF TO THE WEST OVER THE INTERMOUNTAIN WEST INTO THE
PANHANDLE OF IDAHO. EAST OF THE LOW...A LOW AMPLITUDE RIDGE OF
HIGH PRESSURE EXTENDS FROM THE FLORIDA PANHANDLE NORTH TO THE
OHIO VALLEY. HT FALLS THIS MORNING WERE MOST PRONOUNCED ACROSS
EASTERN KANSAS AND EASTERN NEBRASKA...WITH 70 METER FALLS NOTED AT
OMAHA AND 100 METER FALLS NOTED AT TOPEKA. CURRENT SATELLITE
IMAGERY HAS THE LOW NEAR LEXINGTON NEBRASKA WITH A SECONDARY
CIRCULATION NOTED AROUND OMAHA. SHOWERS HAVE CONTINUED TO ROTATE
AROUND THE NORTHERN AND WESTERN PERIPHERY OF THE LOW TODAY AND
HAVE MADE IT AS FAR WEST AS A MERRIMAN TO OGALLALA LINE. OVER THE
PAST COUPLE OF HOURS...SOME CONVECTIVE SHOWERS HAVE DEVELOPED OVER
SERN LINCOLN AND FRONTIER COUNTIES. ELSEWHERE...A MORE PERSISTENT
SHIELD OF RAIN WAS OCCURRING ACROSS THE NEBRASKA SANDHILLS.
HOURLY RAINFALL RATES WERE LIGHT...AT OR UNDER 3 HUNDREDTHS OF AN
INCH. TEMPERATURES AS OF 3 PM CDT RANGED FROM 51 TO 59 DEGREES.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 405 PM CDT WED APR 20 2016
THIS EVENING AND TONIGHT...EXPANDED HIGH CHC POPS WEST TO HWY 83
TO ACCOUNT FOR SCATTERED SHOWERS ROTATING AROUND THE LOW. ALSO
EXPANDED ISO THUNDER MENTION FOR SOUTHERN HALF OF THE FORECAST
AREA. FORECAST SOUNDINGS SHOW STEEP LOW LEVEL LAPSE RATES AND
PERIODS OF SIGNIFICANT LIFT. RAP ANALYSIS ALSO SHOWS MARGINAL
CAPE...GENERALLY 500 J/KG OR LESS...LIFTED INDEX AS LOW AS -1...
AND MID LEVEL LAPSE RATES NEAR 7C/KM. GIVEN DEEP COLD AIR
ALOFT...SMALL HAIL IS POSSIBLE WITH ANY STORM. HRRR AND RAP
INDICATE MOST OF THE SHOWER/STORM ACTIVITY OUTSIDE NORTH CENTRAL
NEBRASKA WILL BE DIURNALLY DRIVEN. SLOWLY PULL POPS FOR
BOYD...HOLT...WHEELER COUNTIES TONIGHT DUE TO THE PROXIMITY OF AN
AREA OF STEADY RAIN OVER NORTHEAST NEBRASKA. MADE LITTLE CHANGE TO
MIN TEMPS AS PREVIOUS FORECAST LOWS ARE SIMILAR TO 12Z MOS
GUIDANCE SUITE...COOLER PANHANDLE AND WEST FOR CLEARING SKY AND
LIGHT WINDS AND MILD NORTH CENTRAL FOR SUSTAINED CLOUDINESS.
DESPITE RECENT RAINFALL AND LIGHTENING WINDS OVERNIGHT...RISK OF
FOG IS LOW. SLIGHTLY DRIER AIR MOVES IN AS SHOWN BY FALLING MIXING
RATIOS...AND AS SURFACE WINDS TURN WESTERLY/NORTHWESTER...ITS NOT
AS FAVORABLE FOR FOG FORMATION.
THURSDAY...H5 LOW SCOOTS EAST INTO IOWA AND THE H3 JET MAX CENTERS
OVER THE MISSOURI RIVER. TRENDED MAX TEMPS TOWARD THE MAV...WHICH
RESULTED IN AN INCREASE OF A DEGREE OR SO AREAWIDE. NAM SOUNDINGS
INDICATE DRY AIR ALOFT...WEAK TO NON EXISTENT LIFT IN THE LOWER
LEVELS...AND A MIXED LAYER APPROACH 700HPA. MID LEVEL FGEN FORCING
ALSO WEAKENS AS THE LOW MOVES EAST OF THE AREA. WITH MAINLY FAIR
CONDITIONS AND UNINHIBITED MIXING...BREEZY NORTH WINDS ARE LIKELY
AND H85 TEMPS AROUND 10C SHOULD TRANSLATE TO HIGHS NEAR 70F.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 405 PM CDT WED APR 20 2016
MID RANGE...THURSDAY NIGHT THROUGH SATURDAY...IN THE MID RANGE...A
BENIGN WEATHER PATTERN IS EXPECTED IN THE MID RANGE WITH
TEMPERATURES BEING THE MAIN FORECASTING CHALLENGE. THE CLOSED LOW
WILL TRACK INTO THE OHIO VALLEY THURSDAY NIGHT INTO FRIDAY...WHILE
RIDGING ALOFT BUILDS EAST FROM THE CENTRAL ROCKIES INTO THE
CENTRAL PLAINS. TEMPERATURES FRIDAY WILL REACH THE LOWER TO MIDDLE
70S...FOLLOWED BY MID 70S TO AROUND 80 FOR SATURDAY. THE LATEST
NAM SOLN WAS BEGINNING TO INDICATE A FAVORABLE ENVIRONMENT FOR
THUNDERSTORMS SATURDAY AFTERNOON IN THE WEST WITH VERY FAVORABLE
SURFACE BASED INSTABILITY AND A DECENT AMOUNT OF SD CAPE.
HOWEVER...SHEAR LOOKS WEAK ATTM. THE GFS AND ECMWF SOLNS HOLD OFF
ON CONVECTION UNTIL SAT EVENING AND HAVE OPTED TO GO THIS ROUTE
AND LEAVE SAT AFTERNOON DRY FOR NOW. BETTER CHANCES FOR
PRECIPITATION WILL ARRIVE IN THE WEST SATURDAY EVENING AS A LEAD
SHORTWAVE CROSSES THE PANHANDLE.
LONG RANGE...SATURDAY NIGHT THROUGH WEDNESDAY...BEGINNING SATURDAY
NIGHT...CHANCES FOR PCPN WILL INCREASE IN THE WEST AS A LEAD
SHORTWAVE CROSSES THE PANHANDLE. THIS WILL BE FOLLOWED BY A CLOSED
LOW WHICH TRACKS ACROSS SRN SD SUNDAY INTO SUNDAY NIGHT. WRAP
AROUND PCPN FROM THE SYSTEM WILL IMPACT THE NORTHERN CWA ON
SUNDAY AND SUNDAY NIGHT. FURTHER SOUTH...COOLER AND WINDY CONDS
ARE EXPECTED SUNDAY...WITH NOT MUCH IN THE WAY OF PCPN EXPECTED.
BETTER CHANCES FOR PRECIPITATION WILL ARRIVE MONDAY NIGHT INTO
WEDNESDAY AS A SECOND UPPER LOW LEVEL LOW TRACKS FROM THE CENTRAL
ROCKIES ONTO THE CENTRAL PLAINS. TEMPERATURES WILL BE MUCH COOLER
AS WELL WITH HIGHS IN THE 50S BY MIDWEEK NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1140 PM CDT WED APR 20 2016
VFR IS EXPECTED ALL AREAS OVERNIGHT THROUGH THURSDAY EVENING.
LOW PRESSURE WILL DRIFT INTO THE MIDWEST THURSDAY WITH DRIER MORE
STABLE AIR MOVING INTO WESTERN AND NORTH CENTRAL NEBRASKA.
&&
.HYDROLOGY...
ISSUED AT 405 PM CDT WED APR 20 2016
RISES EXPECTED TO CONTINUE ON THE SOUTH PLATTE RIVER FOR THE NEXT
SEVERAL DAYS DUE TO RECENT PRECIPITATION OVER WESTERN NEBRASKA
AND COLORADO. USGS STREAM GAUGE AT ATWOOD CO HAS SHOWN A LEVELING
OFF WHILE JULESBURG STILL SHOWS A STEADY RISE. IN COORDINATION
WITH THE MBRFC...A FORECAST SHOWS A CREST AROUND 7 FEET LATE
FRIDAY AT ROSCOE...WHICH PUTS IT AT ACTION STAGE. NO FLOODING IS
EXPECTED AT THIS TIME.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BUTTLER
SHORT TERM...SNIVELY
LONG TERM...BUTTLER
AVIATION...CDC
HYDROLOGY...BUTTLER
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
905 PM PDT FRI APR 22 2016
.SYNOPSIS...A SERIES OF PACIFIC STORM SYSTEMS WILL BRING COOLER
TEMPERATURES, WINDY PERIODS, AND CHANCES OF PRECIPITATION TO
PORTIONS OF THE REGION THROUGH EARLY NEXT WEEK. THE
BEST CHANCES OF PRECIPITATION APPEAR TO BE IN THE SIERRA AND
SOUTHERN GREAT BASIN TONIGHT THEN AGAIN ON MONDAY.
&&
.UPDATE...GUSTY SOUTHWEST WINDS ARE CONTINUING ACROSS MUCH OF THE
MOJAVE DESERT THIS EVENING AHEAD OF A COLD FRONT WHICH IS CURRENTLY
LOCATED ACROSS CENTRAL NEVADA. WINDS HAVE SHIFTED TO THE NORTH IN
BISHOP AND TONOPAH...BUT ARE STILL QUITE GUSTY ACROSS SOUTHERN NYE
AND LINCOLN COUNTIES. ALTHOUGH THE HIGH WIND WARNING EXPIRES AT 9PM
THE WINDS ARE STILL EXPECTED TO BLOW OVER 40 MPH FOR THE NEXT FEW
HOURS AHEAD OF THE FRONT. HAVE GONE AHEAD AND LET THE WARNING EXPIRE
AND ISSUED A WIND ADVISORY FOR BOTH LINCOLN AND SOUTHERN NYE
COUNTIES AND HAVE THAT PRODUCT EXPIRING AT 3AM WITH THE OTHER
REMAINING ADVISORIES ALREADY IN PLACE. THE REMAINDER OF THE GRIDS
ARE IN GOOD SHAPE AND NO OTHER UPDATES NECESSARY.
&&
PREV DISCUSSION
305 PM PDT FRI APR 22 2016
.SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT.
THE VIGOROUS TROUGH DIVING OVER NORTHERN AND CENTRAL CALIFORNIA
WILL CONTINUE TO PRODUCE WIDESPREAD SOUTH-SOUTHWEST WINDS GUSTING
OVER 40 MPH ACROSS MUCH OF THE FORECAST AREA THIS EVENING. THE TROUGH
AXIS IS FORECAST TO QUICKLY TRAVERSE SOUTHERN NEVADA BETWEEN 06Z AND
12Z SATURDAY MORNING AND WE WILL LIKELY SEE SOME OF THE STRONGEST
GUSTS ACROSS SOUTHERN NEVADA AND THE MOJAVE DESERT REGION BETWEEN
05Z AND 09Z. SEVERAL SENSORS ACROSS THE NEVADA NATIONAL SECURITY SITE
IN NORTHERN NYE COUNTY RECORDED GUSTS OVER 60 MPH THIS AFTERNOON AND
A HIGH WIND WARNING WAS ISSUED FOR CENTRAL/SOUTHERN NYE AND WESTERN
LINCOLN COUNTIES AS SIMILAR GUSTS WILL CONTINUE INTO EARLY THIS EVENING.
THE LATEST HIGH RES MODELS INDICATE A FAIRLY QUICK DROP IN WIND SPEEDS
AFTER 04Z ACROSS INYO COUNTY AND SOUTH CENTRAL NEVADA THEN DECREASING
AFTER 10Z FOR THE SPRING MOUNTAINS AND MUCH OF THE MOJAVE DESERT ZONES.
NUMEROUS SHOWERS WILL OCCUR ACROSS NORTHERN INYO AND ESMERALDA COUNTIES
THIS EVENING AND POPS WERE INCREASED CONSIDERABLE FOR THOSE ZONES.
SATURDAY SHOULD BE A FAIRLY PLEASANT DAY WITH NORTHWEST WINDS GENERALLY
LESS THAN 15 MPH AND TEMPERATURES RUNNING ABOUT 10-12 DEGREES COOLER
ACROSS SOUTHERN NEVADA AND SURROUNDING AREAS. ATTENTION THEN TURNS TO
THE NEXT PACIFIC SYSTEM WHICH WILL BE NEAR THE PACIFIC NORTHWEST SUNDAY
MORNING THEN DIVING TOWARD SOUTHERN NEVADA SUNDAY NIGHT. THIS WILL BRING
INCREASING SOUTH-SOUTHWEST WINDS AHEAD OF IT SUNDAY AFTERNOON AND EVENING
AND THE POTENTIAL FOR SHOWERS WILL SPREAD DOWN ACROSS INYO COUNTY AND
SOUTH CENTRAL NEVADA INTO THE SPRING MOUNTAINS AND SHEEP RANGE SUNDAY
NIGHT.
.LONG TERM...MONDAY THROUGH THURSDAY.
ACTIVE PATTERN CONTINUES WITH TWO MORE STORMS IN THE LONG TERM
PERIOD. THE FIRST WILL BE AFFECTING OUR AREA MONDAY. MODELS ARE
CURRENTLY IN GOOD AGREEMENT...AND IF THE SOLUTIONS PAN OUT...PRECIP
CHANCES WOULD BE ROUGHLY FROM LAS VEGAS NORTH WITH STRONG WESTERLY
WINDS FROM LAS VEGAS SOUTH. JUDGING FROM THE CURRENT MODELS...WIND
ADVISORIES WOULD LIKELY BE NEEDED AGAIN FOR MUCH OF THE MOJAVE
DESERT...BUT WILL CONTINUE TO MONITOR FOR ANY NORTHWARD OR SOUTHWARD
SHIFTS IN THE STORM TRACK. SINCE THE STORM IS TRACKING EASTWARD
RATHER THAN SOUTHWARD...POST FRONTAL NORTHERLY WINDS TUESDAY SHOULD
NOT BE SIGNIFICANT. BY WEDNESDAY THE NEXT STORM APPROACHES THE WEST
COAST WITH SOUTHWEST WINDS INCREASING AGAIN.
THERE IS MORE MODEL SPREAD WITH THE TRACK AND STRENGTH OF THIS
STORM...AS IS TYPICAL 6-7 DAYS OUT. A MODEL CONSENSUS WOULD SUGGEST
A SIMILAR OUTCOME TO THE MONDAY STORM...EXCEPT PERHAPS SLIGHTLY LESS
STRONG WIND. PLENTY OF TIME TO WATCH THIS...WITH THE MAIN MESSAGE AT
THIS TIME BEING TO PREPARE FOR WINDY AND RAPIDLY CHANGING WEATHER
FOR MUCH OF NEXT WEEK. SPEAKING OF RAPIDLY CHANGING...TEMPERATURES
WILL CRASH DOWN TO ABOUT TEN DEGREES BELOW NORMAL AREAWIDE ON MONDAY
AND TUESDAY...RISE A BIT WEDNESDAY...THEN GET KNOCKED DOWN AGAIN ON
THURSDAY AS THE NEXT STORM ARRIVES.
&&
.AVIATION...FOR MCCARRAN...WINDY EVENING IN STORE FOR THE TERMINAL
AS A STORM SYSTEM MOVES THROUGH THE AREA TONIGHT AND TOMORROW. SOUTH
WINDS HAVE INCREASED THIS AFTERNOON AND SPEEDS/GUSTS SHOULD CONTINUE
TO CLIMB GRADUALLY THROUGH THIS EVENING AS DIRECTIONS VERY SLOWLY TO
A MORE SOUTHWESTERLY DIRECTION OVERNIGHT. MAX SPEEDS EXPECTED TO BE
20-30 KTS WITH GUSTS UP TO 40 KTS BETWEEN ABOUT 03Z AND 09Z. WINDS
WILL CONTINUE TO VEER AS A COLD FRONT APPROACHES THE VALLEY LATE
TONIGHT...BUT SPEEDS WILL DECREASE RAPIDLY AFTER 09Z. WINDS WILL
SWITCH TO N OR NW IN THE 12Z TO 16Z PERIOD. ALTHOUGH WINDS MAY PICK
UP DURING AND JUST AFTER FRONTAL PASSAGE...MOST GUIDANCE SUGGESTS
SPEEDS 5-15 KTS WITH AN OCCASIONAL GUST TO 20 KTS TOMORROW WITH THE
STRONGEST WINDS IN THE MORNING. FEW-SCT MID AND HIGH CLOUDS EXPECTED
THROUGH THE PERIOD. MECHANICAL TURBULENCE CAN BE EXPECTED THROUGH
TONIGHT ESPECIALLY DOWNSTREAM OF THE SPRING MOUNTAINS.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...SOUTH/SOUTHWEST WINDS HAVE INCREASED ACROSS THE AREA
THIS AFTERNOON WITH SPEEDS GENERALLY 15-30 KTS WITH GUSTS UP TO 40
KTS. WINDS SHOULD CONTINUE TO INCREASE SLOWLY THROUGH THE EVENING
HOURS...ESPECIALLY IN THE SOUTHERN GREAT BASIN AND INYO COUNTY.
SPOTTY AREAS OF BLOWING DUST HAVE BEEN REPORTED THIS AFTERNOON...AND
CAN BE EXPECTED THROUGH THE EVENING HOURS. SPEEDS SHOULD BEGIN TO
DECREASE RAPIDLY AFTER 09Z. MOUNTAIN WAVE ACTIVITY IS POSSIBLE
DOWNSTREAM OF THE SIERRA, WHITES, AND SPRING MOUNTAINS, AND
MECHANICAL TURBULENCE IS LIKELY THROUGH THE OVERNIGHT HOURS. A COLD
FRONT WILL SWEEP ACROSS THE AREA OVERNIGHT AND TOMORROW MORNING,
SWITCHING WINDS TO NORTH/NORTHWEST. DURING AND JUST AFTER FRONTAL
PASSAGE, WINDS MAY PICK UP (10-20 KTS), BUT OVERALL SPEEDS WILL BE
CONSIDERABLY LOWER TOMORROW THAN THOSE OBSERVED TODAY. BRIEF SHOT OF
LIGHT PRECIPITATION IS EXPECTED IN THE SIERRA AND WHITE MOUNTAINS
THIS EVENING/OVERNIGHT WITH BKN-OVC 050-120 CIGS AND SOME MOUNTAIN
OBSCURATIONS POSSIBLE...OTHERWISE FEW-SCT MID AND HIGH CLOUDS ARE
ANTICIPATED FOR MOST OF THE REGION THROUGH THE PERIOD.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTERS SHOULD REPORT ANY
SIGNIFICANT WEATHER ACCORDING TO STANDARD OPERATING PROCEDURES.
$$
UPDATE...GORELOW
SHORT TERM...ADAIR
LONG TERM.... MORGAN
AVIATION....SHAFER
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
[top]
Area Forecast Discussion...UPDATED
National Weather Service Reno NV
736 PM PDT FRI APR 22 2016
.UPDATE...
The cold front has moved completely through western NV as of early
this evening and gradients have relaxed enough to go ahead and
drop the wind advisories and areas of blowing dust. Winds will
still be locally gusty before subsiding further this evening, but
well below earlier peaks.
Convection continues to fire over the Sacramento Valley and then
move eastward into the Tahoe Basin. Moderate to heavy snow was
falling under some of the stronger showers with roads likely to
remain a mess this evening, especially with the sun setting.
Expect another 1 to 3 inches, locally up to 4 inches this evening
before showers begin to diminish. We will continue the snow
advisory through expiration. Scattered snow showers may also
produce periods of slick roads along Hwy 395 through Mono County.
Make sure to check road conditions if you must travel tonight.
Hohmann
&&
.SYNOPSIS...
Moderate to occasionally heavy bands of snow showers will continue
across the Tahoe Basin through this evening with showers more
scattered elsewhere tonight. A break is expected Saturday before
more showers arrive Sunday into Monday. Unsettled weather will
continue through next week with below average temperatures.
&&
.PREVIOUS DISCUSSION... /Issued 303 PM PDT FRI APR 22 2016/
SYNOPSIS...
A strong Pacific storm will continue to move through the Sierra
and Western Nevada tonight. Rain and heavy mountain snow are
expected this evening near and south of I-80. A break is expected
Saturday before more showers are expected Sunday into Monday with
another system. Unsettled weather will continue through next week
with below average temperatures.
SHORT TERM...
A strong spring storm continues to move through. Heavy snow is
falling in the Sierra with rates approaching 3"/hr. It is best to
avoid travel in the Sierra for the next few hours if possible.
Heavy convective snowfall continues in the Sierra with the bands
extending from Westwood south into Bridgeport. Heavy snow is
falling above 6000 feet, with the snow level locally down to 4500
feet in the heaviest bands. Latest satellite/radar trends support
the HRRR in keeping the heaviest rain/snow going thru 03Z near and
south of I-80. After there will be a rapid reduction in showers as
the upper forcing moves east and the airmass stabilizes.
Until then, another 6+ inches of snow is possible above 7000 feet
with another 2-4" down to 5500-6000 feet. Rainfall into Western NV
will be heaviest in the Sierra front where an additional 1/4" of
rain is possible. It may mix with snow at times in the foothills
while lighter amounts are expected toward the highway 95 corridor.
Winds are much weaker along the Sierra Front with the precip
falling, but strong gusts continue east of a Bridgeport to
Lovelock line. Will cancel the advisory for Reno-Carson-Minden,
but leave the remainder as the winds continue there.
Behind this storm, a break is expected Saturday with continued
cool temps, but lighter winds and dry conditions. Another upper
low is expected Sunday afternoon into Monday. Showers are expected
Sunday afternoon with enough instability for a few thunderstorms
as well. The core of the low will move overhead Monday morning
with much colder air. Snow levels will fall to near the valley
floors. While this storm will have some moisture with it, the best
forcing is expected to remain over Eastern NV so we are not
expecting another big precip event. However, there remains a
threat (low at this time) of some light snowfall during the Monday
morning commute along the I-80 and highway 50 corridors. Wallmann
LONG TERM...Monday Night through Friday...
Unsettled weather pattern is expected to continue through next
week as late season storm systems line up to move into the West
Coast. Wednesday-Friday could be a rather wet period for much of
the region with potential for additional snow in higher
elevations.
For Monday night, the first upper low is likely to be on its way
out with lingering rain and snow showers diminishing. Tuesday
still looks like the least active weather day, although a few
showers remain possible as residual moisture will remain in place.
Even though temperatures are expected to increase about 10-15
degrees from Monday, highs in the lower 60s and around 50 degrees
near the Sierra will still be a few degrees below average for late
April.
For next Wednesday-Friday, medium range guidance continues to
indicate a potent low pressure tracking southward along the
California coast, then swing inland across the southwest US (or
possibly farther north into eastern NV). Despite this southerly
track, a broad area of upper divergence and instability is
projected to set up over the Sierra and western NV, along with a
decent tap of Pacific moisture. A few thunderstorms are also
possible each afternoon, although the better instability looks to
be trending north of I-80 by next Friday. Current projections
favor the best overall rain and snow chances Wednesday night and
higher thunderstorm potential on Thursday, but this could vary
depending on the eventual storm track. Widespread cloud cover will
keep daytime temps a few degrees below average each day, with
nighttime temps slightly above average. Early snow level
projections generally range from 6000-7000 feet in the Sierra,
although these snow levels could occasionally drop several hundred
feet during convection or heavier precip bands. MJD
AVIATION...
The most significant weather effects on aviation will continue
through this evening with IFR/LIFR cigs/vsby in snow near the
Sierra including KTVL/KTRK/KMMH, and a few inches of snow
accumulating on pavement. For lower elevations including KRNO-
KCXP, rain will produce MVFR cigs/vsby with mountain obscurations,
IFR at times during heavier rain bands. The strongest winds have
ended at KRNO-KCXP but some gusts to 35 KT remain possible. KMMH
may receive stronger gusts above 40 KT until 03z.
Later tonight, if cloud cover breaks up sufficiently, areas of
FZFG would develop across many Sierra valleys around Tahoe and
northeast CA, including KTRK. For Saturday, generally VFR
conditions are expected with lighter winds. MJD
&&
.REV Watches/Warnings/Advisories...
NV...Winter Weather Advisory until 11 PM PDT this evening NVZ002.
CA...Winter Weather Advisory until 11 PM PDT this evening CAZ072.
&&
$$
For more information from the National Weather Service visit...
http://weather.gov/reno
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
749 PM EDT FRI APR 22 2016
.SYNOPSIS...
ANY SHOWERS WILL COME TO END BY MIDNIGHT AS A COLD FRONT MOVES
SOUTHWARD ACROSS THE NORTH COUNTRY TONIGHT. HIGH PRESSURE WILL
THEN BUILD IN THIS WEEKEND, SETTING US UP FOR SUNNY BUT SEASONABLY
COOL WEATHER. UNSETTLED WEATHER RETURNS SUNDAY NIGHT THROUGH
TUESDAY AS ANOTHER FRONTAL SYSTEM AFFECTS THE REGION AND
TEMPERATURES WILL CONTINUE TO BE BELOW NORMAL.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 749 PM EDT FRIDAY...THE COLD FRONT IS MAKING ITS WAY
SOUTHWARD THIS EVENING ALONG WITH SOME SHOWERS, MAINLY ACROSS
NORTHERN NY AND VT. USING HRRR TO GUIDE NEXT FEW HOURS OF THE
FORECAST WITH SHOWERS EXITING EAST AND WINDS TURNING NORTHERLY.
LOT OF LOW CLOUDS UPSTREAM IN SRN CANADA AND EXPECTING THEM TO
REMAIN OVER THE REGION OVERNIGHT, EXPECT MIN TEMPERATURES IN THE
MID 30S TO MID 40S.
AS MOISTURE QUICKLY EXITS EAST SATURDAY, SKIES EXPECTED TO CLEAR
BY MID TO LATE MORNING HOURS. MUCH COOLER CONDITIONS EXPECTED AS
850MB TEMPERATURES WILL RANGE BETWEEN -2C AND -5C ACROSS THE AREA.
WINDS WILL BE OUT OF THE NORTH TO NORTHWEST AT 5-15KTS AND SOME
GUSTS AROUND 20KTS EXPECTED. AS PWATS FALL TO LESS THAN A QUARTER
INCH, FULL SUNSHINE AND BREEZY CONDITIONS OCCUR DURING THE DAY
RESULTING IN QUICK DRYING BUT COOL TEMPERATURES REMAIN. MAX TEMPS
WILL BE IN THE 40S TO MID 50S.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY/...
AS OF 345 PM EDT FRIDAY...COLD AIR ADVECTION CONTINUES UNDER
NORTHWEST FLOW ON SATURDAY EVENING AS MID-LEVEL TROUGH MOVES OVER
THE REGION WHILE SURFACE HIGH PRESSURE BUILDS INTO THE NORTH
COUNTRY. WITH DRY AIR ALOFT AND CALMING WINDS EXPECT TEMPS TO DROP
QUICKLY AS WE LOSE THE DAYTIME HEATING FROM THE SUN. TEMP SHOULD
DROP INTO THE LOW TO MID 20S WITH TEENS POSSIBLE IN LOWER VALLEYS
AND AREAS OF COLD AIR DRAINAGE SUCH AS SARANAC LAKE. BY MID
MORNING ON SUNDAY THE SURFACE HIGH WILL TRACK TO THE EAST OF THE
NORTH COUNTRY AND WE SHOULD START TO SEE SOME WARMER SOUTHERLY
FLOW, WHICH WILL BRING SUNDAY`S MAX TEMPS CLOSE TO CLIMO NORMALS
FOR LATE APRIL IN THE MID TO UPPER 50S. THE DRY AIR FROM THE HIGH
PRESSURE SYSTEM WILL GENERATE SUNNY SKIES TO BEGIN THE MORNING
HOWEVER TOWARDS THE EVENING AN ADVANCING COLD FRONT WILL BRING AN
INCREASE IN CLOUD COVER.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
AS OF 345 PM EDT FRIDAY...EXPECT A PROLONGED PERIOD OF SPORADIC
SHOWERS TO BEGIN LATE SUNDAY NIGHT DUE TO A SLOW MOVING COLD FRONT
DRAPED ALONG THE INTERNATIONAL BORDER FROM SOUTH DAKOTA TO
NORTHERN NEW YORK. THE FRONT JUST STALLS OUT IN THAT LOCATION
DRIFTING EVER SO SLOWLY TOWARDS THE EAST. THAT SHORTWAVE WILL
CONTINUE TO BE THE SOURCE OF MOISTURE AND SHOWERS ACROSS THE NORTH
COUNTRY THROUGH TUESDAY. CURRENT GUIDANCE POINTS TO THE GREATEST
THREAT FOR SHOWERS TO BE MAINLY LOCATED ACROSS CENTRAL NEW YORK
AND INTO CENTRAL VERMONT. THE SHORTWAVE FINALLY DROPS SOUTH
TUESDAY EVENING LEAVING BEHIND BUILDING HIGH PRESSURE AND
NORTHWEST FLOW AGAIN. FROM THERE WE SHOULD HAVE A PLEASANT DAY
WEDNESDAY WITH A WEAK UPPER LEVEL RIDGE AND MOSTLY DRY AIR. THE
NEXT CHANCE FOR SHOWERS WILL BE ON THURSDAY AS THE CONSENSUS OF
MEDIUM RANGED GUIDANCE POINTS TO A LOW PRESSURE SYSTEM DEVELOPING
ON THE LEE SIDE OF THE ROCKIES AND TRACKING GENERALLY TOWARDS THE
GREAT LAKES. ONCE THE SYSTEM GETS TO THE GREAT LAKES EXPECT A WARM
FRONT TO BRING A PERIOD OF RAIN SHOWERS TO THE NORTH COUNTY BY MID
DAY THURSDAY. EXPECT MOSTLY BELOW NORMAL TEMPERATURES THROUGHOUT
THE LONG TERM.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
THROUGH 00Z SUNDAY...MAINLY MVFR OVERNIGHT IN CIGS THEN TRENDING
VFR BY 14Z SAT.
A FEW ISLD SHOWERS IN THE NEXT COUPLE OF HOURS MAY HAVE BRIEF IFR
(SLK) BUT SHOULDN`T LAST MORE THAN AN HOUR. COLD FRONT NOW JUST
SOUTH OF A SLK BTV LINE WITH SHOWERS ALONG AND NORTH.
GENERALLY DRY CONDITIONS AFTER 02Z...BUT MVFR CIGS LOOK TO SETTLE
IN FOR MOST OF THE NIGHT. CONDITIONS WILL IMPROVE TO VFR AFTER
SUNRISE AND PERSIST THROUGH SATURDAY.
WINDS SHIFTING TO NORTHERLY BEHIND THE COLD FRONTAL PASSAGE AND
REMAINING N-NNW THOUGH SAT. WIND SPEEDS 8-15 KTS WITH A FEW GUST
NEAR 20 KTS OVERNIGHT.
OUTLOOK 00Z SUNDAY THROUGH WEDNESDAY...
00Z SAT - 00Z MON...VFR SKC UNDER HIGH PRESSURE.
00Z MON - 00Z WED...SOME MVFR WITH SHOWERS.
00Z WED ONWARD...VFR UNDER HIGH PRESSURE.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...KGM/SISSON
NEAR TERM...KGM/SISSON
SHORT TERM...DEAL
LONG TERM...DEAL
AVIATION...KGM/SISSON
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1035 PM EDT FRI APR 22 2016
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE AREA LATE TONIGHT. SHOWERS AND
THUNDERSTORMS WILL PRECEDE THE FRONT. AN UPPER LEVEL DISTURBANCE
WILL MOVE ACROSS THE AREA ON SATURDAY. HIGH PRESSURE WILL BUILD
ACROSS THE AREA DURING THE WEEKEND...MOVING OFFSHORE EARLY NEXT
WEEK. WARM TEMPERATURES AND DRY WEATHER ARE EXPECTED THROUGH
MIDWEEK...WITH SCATTERED THUNDERSTORMS POSSIBLE WITH INCREASING
HEAT AND HUMIDITY TOWARDS THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 1030 PM FRIDAY...THINGS HAVE UNFOLDED PRETTY MUCH AS
EXPECTED OVER THE PAST SEVERAL HOURS..AND THAT`S QUITE UNUSUAL WHERE
CONVECTION IS INVOLVED! SURFACE-BASED INSTABILITY IS NOW LIMITED
TO A NARROW STRIP ALONG THE IMMEDIATE COAST WHERE TEMPERATURES ARE
STILL NEAR 70 DEGREES. INLAND CONVECTION HAS LARGELY DECAYED INTO
STRATIFORM RAIN WHICH EXTENDS AS FAR BACK AS DARLINGTON AND
MARLBORO COUNTIES IN SOUTH CAROLINA.
OVER THE PAST FEW HOURS RAINFALL HAS BEEN QUITE SUBSTANTIAL ACROSS
PORTIONS OF THE SC PEE DEE REGION. THE HIGHEST TOTALS ON OUR
MESONET INCLUDE 2.35 INCHES IN NICHOLS (MARION COUNTY), 1.75
INCHES IN KINGSTREE (WILLIAMSBURG COUNTY), AND 1.73 INCHES IN
GREEN SEA (HORRY COUNTY). RADAR ESTIMATES RANGE AS HIGH AS 3.4
INCHES JUST SOUTH OF FLORENCE AND WEST OF MARION. RAINFALL TOTALS FROM
THIS POINT FORWARD SHOULD BE HIGHEST ACROSS THE CAPE FEAR REGION
OF SE NORTH CAROLINA WITH UP TO AN INCH POSSIBLE WHERE TRAINING IS
OCCURRING FROM LAKE WACCAMAW NORTHEASTWARD TO NEAR WALLACE.
LATEST HRRR AND HRRRX RAINFALL PROJECTIONS LOOK VERY REASONABLE.
DISCUSSION FROM 700 PM FOLLOWS...
STRONG THUNDERSTORM ACTIVITY ACROSS THE SOUTH CAROLINA PEE DEE
REGION HAS YET TO BECOME SEVERE. WE RECEIVED A COUPLE OF REPORTS
OF SMALL HAIL (0.5 TO 0.75 INCH DIAMETER) EARLIER FROM THE
FLORENCE VICINITY. BASED ON TEMPERATURES ALOFT WE`RE LOOKING FOR
50 DBZ ECHOES AT OR ABOVE 26000 FEET TO INDICATE A SEVERE HAIL
RISK TODAY. SO FAR REFLECTIVITY CORES ALOFT HAVE REMAINED BELOW
THIS LEVEL. SURFACE- BASED CAPE IS STILL NEAR 1000 J/KG IN THE
WARM AIR (TEMPS > 70) OUT AHEAD OF THE STORMS.
EVOLUTION OF THE CONVECTION OVER THE NEXT FEW HOURS WILL PROBABLY
FOCUS LESS ON SURFACE-BASED INSTABILITY AND MORE ON ELEVATED
INSTABILITY COUPLED WITH SYNOPTICALLY-DRIVEN LOW LEVEL CONVERGENCE
ACROSS THE INTERIOR COASTAL PLAIN. VIRTUALLY ALL MODELS SHOW THE
WEAK AREA OF LOW PRESSURE SOUTH OF ORANGEBURG SC WILL MOVE SLOWLY
NORTH-NORTHEASTWARD. CONVERGING WINDS INTO THIS FEATURE SHOULD
HELP MAINTAIN SHOWERS AND THUNDERSTORMS LARGELY WHERE THE ACTIVITY
CURRENTLY IS OVER THE NEXT SEVERAL HOURS. OUR FOCUS MAY SHIFT
AWAY FROM A HAIL RISK TO A FLOODING RISK WITH TIME.
AS THE WEAK LOW FINALLY MAKES IT UP INTO SE NORTH CAROLINA BY
MIDNIGHT THE BETTER LOW LEVEL CONVERGENCE SHOULD HELP SUPPORT
SHOWERS AND STORMS DOWN AT THE COAST. FORECAST POPS RANGE FROM 100
PERCENT ALONG THE INTERSTATE 95 CORRIDOR TO 60-90 PERCENT ON THE
COAST...INCREASING FROM SOUTH TO NORTH.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
AS OF 220 PM FRIDAY...A ROBUST MID-LEVEL SHORTWAVE TROUGH WILL
MOVE ACROSS THE FORECAST AREA DURING SAT. SHOWERS MAY BE LURKING
NEAR THE COAST AND OFFSHORE AT FIRST LIGHT SAT. THEN AS THIS
FEATURE APPROACHES...SOME COOLING ALOFT COUPLED WITH HEATING AT
THE SURFACE WILL STEEPEN LAPSE RATES. THIS SHOULD ALLOW ISOLATED
TO SCATTERED SHOWERS TO DEVELOP. THE BEST LIFT/COLD POOL
ASSOCIATED WITH THIS DISTURBANCE WILL TRACK N OF THE AREA...WITH
OUR FORECAST AREA ON THE SOUTHERN PERIPHERY. THUS...WILL PORTRAY
HIGHEST POPS NE HALF OF THE FORECAST AREA.
THE SHOWERS SHOULD DISSIPATE WITH THE LOSS OF HEATING WHICH WILL BE
COINCIDENT WITH THE TROUGH MOVING OFFSHORE. WE ARE NOT LOOKING FOR
SIGNIFICANT RAINFALL ON SAT...JUST HIT OR MISS SHOWERS WHICH WILL
TEND TO BE FAST PACED AND THUS BRIEF.
DRY WEATHER THROUGHOUT SAT NIGHT THROUGH SUN NIGHT AS HIGH PRESSURE
BUILDS SOUTHWARD ACROSS THE AREA. TEMPS WILL BE JUST ABOUT NORMAL
FOR LATE APRIL.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 220 PM FRIDAY...THE WEEK WILL BEGIN WITH HIGH PRESSURE
SURFACE-ALOFT PUSHING OFF THE EAST COAST. RETURN FLOW AROUND THE
SURFACE HIGH WILL SET UP LATE MONDAY AND PERSIST THROUGH
WEDNESDAY. 12Z GFS IS INDICATING A WEAK SURFACE FRONT MAY SLIP
SOUTH AND BRIEFLY INTO THE SOUTHERN CWA ON WEDNESDAY BEFORE
QUICKLY LIFTING BACK TO THE NORTH. WILL TWEAK THE FORECAST TOWARDS
THIS SOLUTION BY INDICATING A BRIEF SHIFT TO NORTHEAST WINDS
ACROSS THE NORTHWEST HALF OF THE CWA ON WEDNESDAY. A SMALL CHANCE
OF SHOWERS WILL BE ASSOCIATED WITH THIS BOUNDARY. BETTER CHANCES
FOR CONVECTION ARE EXPECTED ON THURSDAY AND FRIDAY...ALONG WITH A
CHANCE OF THUNDER...AS SURFACE-BASED INSTABILITY INCREASES WITH
SURGING TEMPS/DEWPOINTS. MODELS CONTINUE TO INDICATE A COLD
FRONTAL PASSAGE FRIDAY NIGHT.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AS OF 00Z...SHOWERS AND THUNDERSTORMS AHEAD OF A WEAK COLD FRONT WILL
BE MOST LIKELY FROM KFLO-KLBT EARLY THIS EVENING...SHIFTING TO THE
COASTAL TERMINALS MID TO LATE EVENING. WITH LOSS OF HEATING HOWEVER
THUNDERSTORMS SHOULD BECOME LESS NUMEROUS. TEMPO MVFR LIKELY WITH ANY
PRECIPITATION...ALTHOUGH WITH VERY SHORT PERIODS OF IFR ARE POSSIBLE
IF A THUNDERSTORM MOVES DIRECTLY OVER A TERMINAL.
SHOWERS CHANCES WILL COME TO AN END BY MIDNIGHT AT KFLO/KLBT AS THE
FRONT SLOWLY MOVES EAST...PUSHING OFF THE COAST BEFORE DAYBREAK.
SOUTHERLY WINDS WILL BECOME W-NW BEHIND THE FRONT...BUT LACK OF COLD
ADVECTION OR A TIGHT GRADIENT WILL KEEP WINDS LIGHT. LOW LEVEL MOISTURE
WILL MANIFEST AS LOW STRATUS ALONG THE COAST...WHERE BOUNDARY LAYER WINDS
ARE SLIGHTLY HIGHER...AND FOG AT INLAND TERMINALS WHERE BOUNDARY LAYER
MIXING WILL BE LESS. THERE WILL BE A PERIOD OF TIME SATURDAY MORNING
WHERE CEILINGS AND/OR VISIBILITY WILL DROP INTO THE IFR/LIFR CATEGORY.
CIGS SHOULD QUICKLY INCREASE TO MVFR THEN VFR IN THE MORNING. WINDS
WILL BE W-NE BECOMING N LATER IN THE AFTERNOON. SOME ISOLATED
SHOWERS POSSIBLE NEAR KILM IN THE AFTERNOON.
EXTENDED OUTLOOK...VFR
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM FRIDAY...NO SUBSTANTIAL CHANGES ARE NEEDED TO THE
FORECAST THIS EVENING. SHOWERS AND EMBEDDED TSTMS EXTEND FROM
MYRTLE BEACH NORTHWARD ACROSS INTERIOR EASTERN NORTH CAROLINA AND
SHOULD REACH CAPE FEAR BY MIDNIGHT. DISCUSSION FROM 700 PM
FOLLOWS...
HIGH PRESSURE OUT NEAR BERMUDA IS DRAGGING AIR FROM THE NORTHERN
CARIBBEAN AND BAHAMAS UP THE COAST AND ACROSS THE CAROLINAS. A
COLD FRONT JUST WEST OF THE APPALACHIANS IS MOVING EASTWARD AND
SHOULD REACH THE COASTAL WATERS AROUND SUNRISE SATURDAY MORNING.
SOUTH WINDS SHOULD AVERAGE 15 KT ACROSS THE SC WATERS AND 15-20 KT
ACROSS THE NC WATERS TONIGHT... DIMINISHING BY ABOUT 5 KNOTS AFTER
3-4 AM AS A WAVE OF LOW PRESSURE ALONG THE FRONT IN SOUTH CAROLINA
MOVES NORTH OF THE AREA. SHOWERS AND THUNDERSTORMS INLAND SHOULD
REACH THE COASTAL WATERS BY LATE THIS EVENING AND THERE MAY BE
GOOD COVERAGE OF RAIN ACROSS THE WATERS AFTER
MIDNIGHT...ESPECIALLY NORTH OF CAPE FEAR.
SEAS ARE CURRENTLY 3-4 FEET AT THE CAPE FEAR NEARSHORE BUOYS AND 5
FEET OUT AT THE FRYING PAN SHOALS BUOY. LOOK FOR THESE WAVE
HEIGHTS TO BUILD BY ABOUT A FOOT OVER THE NEXT SEVERAL HOURS.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 220 PM FRIDAY...A COLD FRONT MAY LINGER NEAR THE OFFSHORE
WATERS...WAITING ON A POTENT SHORTWAVE TROUGH BEFORE PUSHING
FURTHER OFFSHORE DURING SAT. W WINDS TO START THE DAY SAT ARE
EXPECTED TO VEER TO NW....BEFORE SHIFTING TO THE N AND NE AND
INCREASING TO NEAR 20 KT SAT NIGHT. A SMALL CRAFT SHOULD EXERCISE
CAUTION HEADLINE MAY BE REQUIRED SAT NIGHT INTO EARLY SUN MORNING.
AS HIGH PRESSURE TO THE N GROWS CLOSER...WIND SPEEDS WILL DECREASE
TO 10 TO 15 KT DURING SUN AND TO 10 KT OR LESS SUN NIGHT. THE WIND
DIRECTION WILL VEER FROM NE SUN TO E SUN NIGHT.
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 220 PM FRIDAY...SURFACE HIGH PRESSURE WILL SHIFT OFF THE
COAST EARLY MONDAY AND WILL BE THE MAIN INFLUENCE ON THE MARINE
FORECAST THROUGH WEDNESDAY. WINDS ARE EXPECTED TO BE LIGHT WITH
SOME VARIABILITY EARLY MONDAY UNTIL THE CENTER OF THE HIGH MOVES
AWAY FROM THE COAST. THIS WILL ALLOW SOUTHWEST WINDS TO DEVELOP
OVER THE WATERS...WHICH WILL INCREASE TO A 10-15 KNOT RANGE TUE-
WED. A WEAK COLD FRONT IS EXPECTED TO APPROACH FROM THE NORTH ON
WEDNESDAY AND WILL RESULT IN WINDS BACKING TO THE EAST AND PERHAPS
NORTHEAST BRIEFLY..GENERALLY NORTH OF CAPE FEAR.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...CRM
NEAR TERM...TRA
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...MRR
AREA FORECAST DISCUSSION
NWS RALEIGH NC
950 PM EDT FRI APR 22 2016
.SYNOPSIS...AN UPPER LEVEL TROUGH AND ACCOMPANYING WEAK SURFACE COLD
FRONT WILL CROSS THE MIDDLE ATLANTIC STATES LATE TONIGHT AND EARLY
SATURDAY. A SECONDARY COLD FRONT WILL SETTLE SOUTHEAST THROUGH THE
AREA SATURDAY EVENING....FOLLOWED BY HIGH PRESSURE ON SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 950 PM FRIDAY...
THE UPPER TROUGH AXIS AND SYNOPTIC COLD FRONT REMAIN JUST WEST OF
THE MOUNTAINS THIS EVENING...WHILE THE DOWNSTREAM CLUSTERS OF
SHOWERS AND ISOLATED STORMS HAVE BECOME MOSTLY CONFINED TO ONE
COMMON CONVERGENCE AXIS IN THE COASTAL PLAIN...EAST OF THE RAH CWA.
MOISTURE TRANSPORT REMAINS GREATEST OVER EASTERN NC...WATER VAPOR
IMAGERY STILL SUGGESTS A COUPLE DISTURBANCES ALOFT THAT WILL TRACK
NORTHEAST ACROSS NC THIS EVENING. THE MORE NOTABLE DISTURBANCES
IS CURRENTLY MOVING OVER EAST-CENTRAL SC AND WILL LIKELY CAUSE
SHOWERS TO EXPAND A LITTLE BACK TO THE WEST TOWARD THE I-95 CORRIDOR
AS THEY MOVE THROUGH THE NC COASTAL PLAIN IN THE NEXT FEW HOURS.
LATEST HRRR ITERATIONS SHOW THIS AS THE LAST REAL GASP OF
PRECIP...WITH JUST A FEW ISOLATED SHOWERS NEAR THE COLD FRONT AS IT
MOVES INTO THE MORE STABLE AIRMASS OVER THE PIEDMONT LATER TONIGHT.
AM ISOLATED STORM NEAR OR EAST OF I-95 IS STILL POSSIBLE...BUT THE
THREAT OF STRONG UPDRAFTS AND ANY NEAR SEVERE STORMS HAS LIKELY
PASSED.
THE OTHER FORECAST CONCERN OVERNIGHT IS THE POTENTIAL FOR FOG GIVEN
CLEARING ALOFT FROM WEST TO EAST AND THE DELAYED ARRIVAL OF THE COLD
FRONT AND DRIER NORTHWEST FLOW. WHILE THE SIGNAL IS NOT
OVERWHELMINGLY STRONG...RAP AND HRRR SOUNDINGS INDICATE THE FOG
POTENTIAL PRIMARILY IN THE WESTERN PIEDMONT FROM 05Z TO 10Z. TEMPS
SHOULDN`T HAVE MUCH CHANCE TO FALL PRIOR TOT HE COLD FRONT...WITH
LOWS IN THE MID 50S TO LOWER 60S.
&&
.SHORT TERM /SATURDAY AND SATURDAY NIGHT/...
AS OF 235 PM FRIDAY...
THE INITIAL COLD FRONT SHOULD HAVE MOVED TO COASTAL NC BY DAYBREAK
SAT. AREAS OF LOW CLOUDS AND PATCHY FOG IN THE MORNING SHOULD BURN
OFF QUICKLY WITH DRY AIR ABOVE IT THROUGH THE MID LEVELS. THE MID
LEVEL SHORTWAVE TROUGH AXIS WILL BE SITUATED OVERHEAD THROUGH
CENTRAL VA AND CENTRAL NC AND WILL MOVE SLOWLY ESE THROUGH THE
DAY... BRINGING A POCKET OF HIGHER MID LEVEL LAPSE RATES (AOA 6.0
C/KM) ACROSS THE AREA... REACHING THE ERN FORECAST AREA DURING PEAK
HEATING. WHILE ANY MOISTURE WILL BE SHALLOW... THE POSSIBILITY OF
MINOR INSTABILITY WITH THE ATTENDANT DPVA AND POCKET OF COOLER AIR
ALOFT COULD STILL SUPPORT ISOLATED TO SCATTERED SHOWERS... MAINLY
FROM THE TRIANGLE NORTH AND EAST IN THE AFTERNOON. ANY ADDITIONAL
RAINFALL AMOUNTS WILL BE SMALL. OTHERWISE... EXPECT PARTLY TO MOSTLY
SUNNY SKIES. THIS INITIAL FRONT WILL NOT HAVE A LOT OF COOL AIR
RIGHT BEHIND IT... AS THICKNESSES DROP ONLY SLIGHTLY AND REMAIN
ABOVE NORMAL. EXPECT HIGHS IN THE MID 70S TO NEAR 80. THE SECONDARY
AND MORE SUBSTANTIAL COLD FRONT DROPS SE THROUGH THE AREA SAT
EVENING... WITH SURFACE WINDS SHIFTING FROM NNW TO NE AND A COOLER
RIDGE BUILDING IN FROM THE NORTH. SHOULD SEE MOSTLY CLEAR SKIES SAT
NIGHT... ALTHOUGH SCATTERED STRATOCU ARE POSSIBLE NEAR 4-6 KFT AGL
AS THE 850 MB ANTICYCLONE MOVES IN FROM THE WEST YIELDING A POOLING
OF MOISTURE AT THAT LEVEL OVERNIGHT. THICKNESS DROP BACK DOWN NEAR
OR JUST BELOW NORMAL WITH THE FRONTAL PASSAGE... SUPPORTING LOWS IN
THE LOWER TO MID 50S. -GIH
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
AS OF 305 AM FRIDAY...
SUNDAY THROUGH TUESDAY: HIGH PRESSURE WILL MOVE FROM THE MID-
ATLANTIC STATES TO OFF OF THE CAROLINA COAST ON SUNDAY AND STAY
THERE THROUGH THE EARLY PART OF THE WORK WEEK. THIS WILL PUT CENTRAL
NC IN THE SOUTHWESTERLY RETURN FLOW AND HELP TEMPERATURES RISE INTO
THE MID TO EVEN UPPER 80S BY THE TIME TUESDAY AFTERNOON COMES
AROUND. PRIOR TO THAT...TEMPS ON SUNDAY WILL TOP OUT IN THE MID TO
UPPER 70S BEFORE RISING INTO THE LOW 80S ON MONDAY. LOWS DURING THIS
TIME IN THE MID 50S TO LOWER 60S.
WEDNESDAY THROUGH FRIDAY: A LOW PRESSURE SYSTEM SITUATED OVER THE
CENTRAL U.S. WILL MOVE TOWARDS THE GREAT LAKES ON WEDNESDAY AS A
BACKDOOR COLD FRONT EXTENDING NEARLY DUE EAST FROM THE CENTER OF THE
LOW IS EXPECTED TO MOVE THROUGH THE MID-ATLANTIC STATES AND APPROACH
THE NORTHERN PARTS OF THE FORECAST AREA. THEREFORE THERE WILL BE A
SLIGHT CHANCE OF SHOWERS ESPECIALLY ACROSS THE NORTH ON WEDNESDAY
BUT CONFIDENCE IS STILL LOW ON HOW FAR SOUTH THE FRONT WILL
PROGRESS. WHILE SOME CAPE IS AVAILABLE WEDNESDAY AFTERNOON...THE
SHEAR IS MEAGER UNTIL LATE AFTERNOON WHEN IT PICKS UP ACROSS THE NW
PIEDMONT. THEREFORE A THUNDERSTORM IS POSSIBLE BUT THE MODE OF
PRECIPITATION...IF WE GET ANY...SHOULD BE JUST SHOWERS FOR MUCH OF
THE DAY. THE GFS IS PREDICTING THE COLD FRONT TO MOVE ALL THE WAY
THROUGH NC BECAUSE OF A DEVELOPING MESO-HIGH NORTH OF THE AREA BUT
THIS FEATURE IS LESS PRONOUNCED IN MOST OTHER MODELS. THE ECMWF
FOLLOWS MORE IN LINE WITH WPC THINKING WITH THE COLD FRONT ONLY
REACHING THE NORTHERN PARTS OF THE STATE. MOST MODEL BLENDS ALSO
KEEP US LARGELY IN THE WARM SECTOR ON WEDNESDAY AS WELL. THEREFORE
TRENDING WARMER WITH TEMPERATURES WEDNESDAY AFTERNOON WITH HIGHS AT
LEAST IN THE LOW TO MID 80S WITH SOME UPPER 80S POSSIBLE IN THE
SOUTHWEST. LOWS IN THE UPPER 50S TO LOW 60S WEDNESDAY NIGHT INTO
THURSDAY MORNING.
A SECOND COLD FRONT WILL APPROACH THE AREA AS THE LOW PRESSURE
SYSTEM MOVES NORTHEAST WEDNESDAY NIGHT AND INTO THURSDAY MORNING.
THE COLD FRONT SHOULD MOVE THROUGH THE AREA THROUGHOUT THE DAY ON
THURSDAY BRINGING A CHANCE OF SHOWERS AND A SLIGHT CHANCE OF
THUNDERSTORMS. SHOWERS COULD EXTEND INTO FRIDAY DEPENDING ON THE
POSITION OF THE COLD FRONT AND HOW WELL IT HOLDS TOGETHER BUT
CONFIDENCE IN THE FORECAST THIS FAR OUT IS LOW AT THIS TIME. WILL
CARRY LOW SLIGHT CHANCE POPS IN THE FORECAST FOR NOW. DESPITE THE
SURFACE FRONT TRYING TO MOVE THROUGH THE AREA...THERE WILL NOT BE
MUCH CHANGE IN AIRMASS ON FRIDAY THEREFORE TEMPS ARE EXPECTED TO BE
HIGHER THAN AVERAGE WITH HIGHS IN THE LOW TO MID 80S THURSDAY
AND FRIDAY AND LOWS IN THE UPPER 50S TO MID 60S.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AS OF 835 PM FRIDAY...
MAINLY VFR CONDITIONS ARE EXPECTED THIS EVENING...AMIDST PERIODS OF
MAINLY LIGHT RAIN FROM MID LEVEL CEILINGS. HOWEVER...TEMPORARY SUB-
VFR CONDITIONS WILL ACCOMPANY ISOLATED TO WIDELY SCATTERED
CONVECTIVE PRECIPITATION THAT WILL REMAIN POSSIBLE TONIGHT...IN
ASSOCIATION WITH THE APPROACH OF AN UPPER LEVEL TROUGH AND WEAK
SURFACE COLD FRONT. IN ADDITION...WEST TO EAST CLEARING BETWEEN 06Z-
12Z WILL PROMOTE THE DEVELOPMENT OF FOG AND/OR LOW STRATUS LATE
TONIGHT-EARLY SATURDAY. ANY FOG/STRATUS SHOULD QUICKLY DISPERSE
SHORTLY AFTER SUNRISE.
ASIDE FROM A SMALL CHANCE OF A SHOWER OVER NORTHEASTERN NC --
INCLUDING AT KRWI-- EARLY SATURDAY AFTERNOON...VFR CONDITIONS AND
LIGHT NNW WINDS ARE EXPECTED THROUGH THE END OF THE TAF PERIOD.
OUTLOOK: A FRONTAL ZONE WILL SETTLE INTO VA/NC AND RESULT IN A
CHANCE OF SHOWERS AND STORMS...AND SUB-VFR CEILINGS ON THE
NORTH/COOL SIDE OF THE BOUNDARY...DURING THE MIDDLE OF THE WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...26
NEAR TERM...22
SHORT TERM...HARTFIELD
LONG TERM...ELLIS/DND
AVIATION...26
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
100 PM EDT THU APR 21 2016
.SYNOPSIS...
HIGH PRESSURE WILL GRADUALLY MOVE OFFSHORE THROUGH TONIGHT. A
COLD FRONT WILL APPROACH FROM THE WEST FRIDAY, THEN MOVE THROUGH
THE AREA SATURDAY. HIGH PRESSURE WILL BUILD OVER THE AREA SUNDAY
AND MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1250 PM THURSDAY, BASED ON CURRENT OBSERVATIONS, RAISED
MAXIMUM TEMPERATURES THIS AFTERNOON A COUPLE OF DEGREES AREA-WIDE.
PARTLY CLOUDY SKIES CONTINUE WITH INCREASING DEWPOINTS. HIGH
RESOLUTION MODELS SUCH AS THE HRRR AND NSSL WRF INDICATE SCATTERED
SHOWERS DEVELOPING IN THE NEXT COUPLE OF HOURS INLAND, MAINLY WEST
OF HIGHWAY 17. CURRENT POP FORECAST DEPICTS THIS WELL AND NO
CHANGES MADE AT THIS TIME.
THE WHIPPING CREEK WILDFIRE ALONG THE MAINLAND DARE/MAINLAND HYDE
COUNTY BORDER HAS DROPPED TO ABOUT 9800 ACRES...BUT WILL LIKELY
CONTINUE TO PRODUCE SMOKE ISSUES FOR THE NEXT SEVERAL DAYS. IN
COORDINATION WITH THE STATE OF NORTH CAROLINA...AN AIR QUALITY
ALERT HAS BEEN ISSUED FOR SEVERAL COUNTIES BORDERING THE FIRE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
AS OF 330 AM THURSDAY...PRE-FRONTAL WARM SECTOR CONDITIONS
EXPECTED OVERNIGHT AFTER WEAK WARM FRONT MOVES TO N. MODELS IN
AGREEMENT THAT PCPN THREAT WILL REMAIN OFFSHORE. SOUTHERLY WINDS
AND PARTLY TO MOSTLY CLOUDY SKIES WILL KEEP MIN TEMPS IN LOWER
60S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
AS OF 3 AM THURSDAY...
FRIDAY THROUGH SATURDAY: LITTLE CHANGE IN REASONING FOR THE LATE
WEEK SYSTEM. A FRONT WILL APPROACH THE AREA FROM THE WEST AND CROSS
THE REGION SATURDAY MORNING. MOISTURE AHEAD OF THE FRONT WILL RAMP
UP THROUGH THE DAY FRIDAY WITH SHOWERS AND SOME STORMS POSSIBLE BY
THE AFTERNOON. PWATS LOOK TO CLIMB TO NEAR 1.5", WITH MARGINAL
INSTABILITY IN PLACE IN THE AFTERNOON/EVENING HOURS.
INSTABILITY HAS SEEMED TO INCREASE A BIT WITH THE LATEST MODEL
RUNS, POSSIBILITY GIVEN BETTER CONVERGENCE IN THE MID-LEVELS AND
SFC BASED INHIBITION. THE SHEAR PARAMETERS ALSO LOOKS FAIRLY
MARGINAL THROUGH THIS PERIOD. CONFIDENCE IS INCREASING THAT THERE
WILL BE SOME THUNDERSTORM DEVELOPMENT, ALTHOUGH WIDESPREAD
COVERAGE IS UNLIKELY. PRECIPITATION AMOUNTS WITH THIS FROPA LOOK
TO BE AROUND A QUARTER OF AN INCH WITH LOCALLY HIGHER AMOUNTS
ASSOCIATED WITH ANY THUNDERSTORMS.
SO EXPECT CLOUDS/PRECIP TO INCREASE FRIDAY WITH SOUTHERLY FLOW
ACROSS THE AREA. HIGHS IN THE UPPER 70S INLAND TO AROUND 70 ALONG
THE OBX. LOWS TEMPS BY EARLY SATURDAY MORNING WILL BE AROUND 60
DEGREES. THE INITIAL FRONT WILL PULL THROUGH BY 12Z SATURDAY WITH
NORTHWEST DEVELOPING, FOLLOWED BY A SECONDARY FRONT AROUND MID DAY
WITH WINDS BECOMING NORTHERLY. MOST OF THE PRECIPITATION SHOULD BE
OFFSHORE BY SATURDAY MID-MORNING WITH HIGH PRESSURE MOVING INTO
THE AREA FROM THE NORTH. GIVEN SUBSIDENCE FLOW ACROSS THE REGION,
EXPECT TEMPS SATURDAY TO CLIMB INTO THE MID-70S INLAND TO THE MID
60S ALONG THE OBX. SEVERAL 00Z MODELS CONTINUE TO INDICATE AN
ISOLATED SHOWERS POSSIBLE SATURDAY AFTERNOON AS THE SECONDARY
FRONT AND MID LEVEL TROUGH AXIS PUSHES ACROSS THE AREA SO KEPT
SLIGHT CHANCE POPS THROUGH THE AFTERNOON HOURS.
SATURDAY NIGHT THROUGH MONDAY NIGHT: VERY PLEASANT WEATHER FOR
THIS PERIOD AS AN UPPER RIDGE BUILDS ACROSS THE EASTERN CONUS AND
SFC HIGH PRESSURE ANCHORED ACROSS NEW ENGLAND TRANSITIONS TO THE
SOUTHEAST, EVENTUALLY MOVING OFF THE MID-ATLANTIC COAST BY SUNDAY
AFTERNOON. THIS WILL ALLOW RETURN FLOW TO DEVELOP THROUGH THE
PERIOD. TEMPERATURES WILL RISE INTO THE UPPER 70S INLAND TO THE
MID 60S ALONG THE OBX SUNDAY. WITH THE HIGH PRESSURE OFF THE COAST
AND AN APPROACHING LOW FROM THE NORTHWEST, THE PRESSURE GRADIENT
WILL TIGHTEN WITH STRONG/WARM SOUTHWEST FLOW HELPING TEMPS CLIMB
INTO THE LOW 80S INLAND TO AROUND 70 ALONG THE OBX. LOW TEMPS
DURING THIS PERIOD WILL BE INCREASING, LOW 50S SUNDAY MORNING TO
LOW 60S BY TUESDAY MORNING.
TUESDAY THROUGH WEDNESDAY: THE UPPER RIDGE BREAKS DOWN AS A
DAMPENING SHORTWAVE MOVES INTO THE GREAT LAKES REGION AS WE MOVE
TO THE MIDDLE OF NEXT WEEK. A TRAILING COLD FRONT WILL BE NORTH
OF THE AREA THROUGH THE PERIOD, EVENTUALLY SAGGING INTO THE REGION
TUESDAY NIGHT OR WEDNESDAY. THIS WILL MEAN CONTINUED SOUTHERLY
FLOW TUESDAY AND INCREASED MOISTURE FEED ACROSS THE AREA. AREA OF
CONVERGENCE DOESN`T SEEM TOO STRONG, SUGGESTING NOT TOO MUCH IN
THE WAY OF PRECIPITATION WITH THIS BACKDOOR FROPA. MODELS NOT IN
BEST AGREEMENT WITH THE STRENGTH OF THE SHORTWAVE TO OR THE
TIMING OF THE FRONT AND WILL LIMIT POPS TO SLIGHT CHANCE THIS
PERIOD. TEMPS WILL CLIMB INTO THE MID 80S INLAND TO AROUND 70
ALONG THE OBX.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
SHORT TERM /THROUGH 18Z FRIDAY/...INCREASING DEWPOINTS AND A
DEVELOPING LOW-LEVEL INVERSION WILL LEAD TO A PERIOD OF MVFR
CEILINGS LATE TONIGHT/EARLY FRIDAY, MAINLY FROM 08Z-12Z. THINK
MUCH OF THE REMAINDER OF THE TAF CYCLE WILL FEATURE VFR
CONDITIONS, BUT WITH SOME SCATTERED SHOWERS, ESPECIALLY KISO/KPGV
THIS AFTERNOON AND AT ALL SITES FROM LATE MORNING INTO AFTERNOON
ON FRIDAY. SOUTH TO SOUTHWEST WINDS WILL CONTINUE TO GUSTS TO AS
HIGH AS 15-20 MPH LATE THIS AFTERNOON AND EVENING.
LONG TERM /FRIDAY THROUGH MONDAY/
AS OF 330 AM THURSDAY...A FRONT WILL APPROACH FRIDAY AND CROSS
THE REGION SATURDAY MORNING. SHOWERS AND ISOLATED THUNDERSTORM
CHANCES INCREASE FRIDAY AFTERNOON WITH PERIODS OF SUB-VFR
CONDITIONS POSSIBLE CONTINUING THROUGH THE EVENING HOURS
ESPECIALLY WITH ANY HEAVIER SHOWERS/STORMS DURING THIS TIME. GUSTY
SOUTHERLY FLOW AHEAD OF THE FRONT CAN BE EXPECTED FRIDAY,
ESPECIALLY DURING THE AFTERNOON THROUGH THE OVERNIGHT.
PRECIPITATION WILL DIMINISH ACROSS THE TAF SITES EARLY SATURDAY
MORNING AS THE FRONT PUSHES OFFSHORE BUT CANNOT RULE OUT A FEW
SHOWERS CONTINUING THROUGH THE DAY SATURDAY. EXPECT NORTHWEST FLOW
BEHIND THE FRONT SATURDAY MORNING WITH WINDS BECOMING NORTH BEHIND
A SECONDARY FRONT SATURDAY AFTERNOON. HIGH PRESSURE WILL THEN
BUILD INTO THE REGION THROUGH THE REMAINDER OF THE PERIOD WITH
PRED VFR CONDITIONS EXPECTED.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 1 PM THURSDAY, SOUTH WINDS CONTINUE AT 5-15 KNOTS THIS
AFTERNOON WITH SEAS HOVERING AROUND 4 FEET. STILL SEEING SOME
6-FOOTER AROUND DIAMOND BUOY AND HAVE ISSUED A MARINE WEATHER
STATEMENT INTO EARLY AFTERNOON. WILL MONITOR AND MAY ISSUE A
SHORT-LIVED SMALL CRAFT ADVISORY FOR THE MIDDLE WATERS IF THIS
TREND CONTINUES. SEAS WILL SUBSIDE TO 2-4 FT THIS AFTERNOON...THEN
BUILD BACK TO 3-5 FT BY TONIGHT.
LONG TERM /FRIDAY THROUGH MONDAY/
AS OF 330 AM THURSDAY...SOUTHERLY FLOW WILL INCREASE AHEAD OF A
FRONT THAT WILL CROSS THE AREA EARLY SATURDAY. EXPECT 15-20 KTS
WITH HIGHER GUSTS FRIDAY AFTERNOON THROUGH THE OVERNIGHT WITH THE
FROPA THROUGH THE WATERS EARLY SATURDAY MORNING. SEAS WILL BUILD
ALONG THE SOUTHERN/CENTRAL WATERS, TOPPING OUT AROUND 5-6FT FRIDAY
NIGHT. NORTHWEST FLOW AROUND 10-15 KTS WILL DEVELOP BEHIND THE FRONT
SATURDAY MORNING, THEN A NORTHERLY SURGE AROUND 10-20 KTS BEHIND A
SECONDARY FRONT WITH SEAS GRADUALLY DIMINISHING TO 2-4 FT. HIGH PRES
WILL BE CENTERED OVER THE AREA SUNDAY THEN WILL MOVE OFFSHORE
MONDAY. NE FLOW AROUND 15 KT OR LESS SUNDAY MORNING DIMINISHES TO 10
KT OR LESS WHILE VEERING TO SOUTHEAST THEN SOUTH SUNDAY AFTERNOON
AND EVENING, BECOMING SW BY MONDAY AND INCREASING TO 10-15 KT WITH
SEAS AROUND 2-4 FT.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...BEACH HAZARDS STATEMENT UNTIL 8 PM EDT THIS EVENING FOR NCZ095-
103-104.
MARINE...NONE.
&&
$$
SYNOPSIS...JBM
NEAR TERM...CTC
SHORT TERM...JBM
LONG TERM...SK
AVIATION...CTC/SK
MARINE...CTC/JBM/SK
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1236 PM CDT THU APR 21 2016
.UPDATE...
ISSUED AT 1233 PM CDT THU APR 21 2016
LOW CLOUD COVER CONTINUES TO ERODE WITH MOSTLY SUNNY SKIES OVER
THE AREA.
UPDATE ISSUED AT 911 AM CDT THU APR 21 2016
FOR MORNING UPDATE MAIN CHANGES WERE TO WIND AND CLOUD COVER.
LATEST MAV GUIDANCE HAS A PRETTY GOOD GRASP ON WINDS WHICH ARE
HIGHER THAN PREVIOUS FORECAST SUGGESTED. THEREFORE...HAVE
INCREASED WIND SPEEDS A BIT...PARTICULARLY OVER CENTRAL NORTH
DAKOTA. NEXT CONCERN IS CLOUD COVER WITH SOME EXPANDING AREAS OF
LOW CLOUDS. HRRR RUNS CONTINUE THE EXPANSION OF THE LOW CLOUD
COVER THROUGH THE MORNING...RAISING IT AND BREAKING IT UP IN THE
AFTERNOON. WILL ADDRESS THIS BY RAISING CLOUD COVER OVER MOST
AREAS.
UPDATE ISSUED AT 638 AM CDT THU APR 21 2016
NO CHANGES TO THE FORECAST OTHER THAN TO BLEND TO OBSERVED TRENDS
THROUGH 11 UTC AS THE SURFACE COLD FRONT HAS PROPAGATED THROUGH
NORTH DAKOTA EARLY THIS MORNING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 318 AM CDT THU APR 21 2016
EARLY THIS MORNING A COLD FRONT CONTINUED TO PUSH SOUTHEAST ACROSS
THE STATE. MOST LOCATIONS HAVE SWITCHED OVER TO NORTHWEST WINDS
AND COLD AIR ADVECTION HAS TAKEN HOLD. TEMPERATURES TODAY WILL BE
COOLER WITH READINGS MAINLY IN THE 50S AS COLD AIR ADVECTION WILL
CONTINUE THROUGH THE DAY.
TONIGHT...HIGH PRESSURE SHIFTS OFF TO THE EAST AND RETURN FLOW
KICKS IN.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 318 AM CDT THU APR 21 2016
THE END OF THE WEEK LOOKS RATHER WARM. STRONG WARM AIR ADVECTION
AHEAD OF AN APPROACHING LOW PRESSURE SYSTEM WILL COMBINE WITH
COMPRESSIONAL WARMING TO PRODUCE TEMPERATURES NEAR 80 ACROSS
PORTIONS OF WESTERN AND SOUTHERN NORTH DAKOTA.
A POTENT SYSTEM IS TAKING AIM ON THE NORTHERN PLAINS FOR SATURDAY
AND SUNDAY. MODELS ARE IN SURPRISINGLY GOOD AGREEMENT WITH TIMING
AND PLACEMENT OF PRECIPITATION. THEREFORE...THUNDERSTORMS AND
WIDESPREAD RAINFALL APPEAR LIKELY AS A STACKED LOW DEVELOPS OVER
SOUTH DAKOTA. AT THIS TIME IT APPEARS PRECIPITATION AMOUNTS NEAR
AN INCH ARE POSSIBLE ACROSS PORTIONS OF SOUTHERN NORTH DAKOTA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1233 PM CDT THU APR 21 2016
VFR CONDITIONS THROUGH THE FORECAST PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JJS
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...JJS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
932 AM CDT THU APR 21 2016
.UPDATE...
ISSUED AT 911 AM CDT THU APR 21 2016
FOR MORNING UPDATE MAIN CHANGES WERE TO WIND AND CLOUD COVER.
LATEST MAV GUIDANCE HAS A PRETTY GOOD GRASP ON WINDS WHICH ARE
HIGHER THAN PREVIOUS FORECAST SUGGESTED. THEREFORE...HAVE
INCREASED WIND SPEEDS A BIT...PARTICULARLY OVER CENTRAL NORTH
DAKOTA. NEXT CONCERN IS CLOUD COVER WITH SOME EXPANDING AREAS OF
LOW CLOUDS. HRRR RUNS CONTINUE THE EXPANSION OF THE LOW CLOUD
COVER THROUGH THE MORNING...RAISING IT AND BREAKING IT UP IN THE
AFTERNOON. WILL ADDRESS THIS BY RAISING CLOUD COVER OVER MOST
AREAS.
UPDATE ISSUED AT 638 AM CDT THU APR 21 2016
NO CHANGES TO THE FORECAST OTHER THAN TO BLEND TO OBSERVED TRENDS
THROUGH 11 UTC AS THE SURFACE COLD FRONT HAS PROPAGATED THROUGH
NORTH DAKOTA EARLY THIS MORNING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 318 AM CDT THU APR 21 2016
EARLY THIS MORNING A COLD FRONT CONTINUED TO PUSH SOUTHEAST ACROSS
THE STATE. MOST LOCATIONS HAVE SWITCHED OVER TO NORTHWEST WINDS
AND COLD AIR ADVECTION HAS TAKEN HOLD. TEMPERATURES TODAY WILL BE
COOLER WITH READINGS MAINLY IN THE 50S AS COLD AIR ADVECTION WILL
CONTINUE THROUGH THE DAY.
TONIGHT...HIGH PRESSURE SHIFTS OFF TO THE EAST AND RETURN FLOW
KICKS IN.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 318 AM CDT THU APR 21 2016
THE END OF THE WEEK LOOKS RATHER WARM. STRONG WARM AIR ADVECTION
AHEAD OF AN APPROACHING LOW PRESSURE SYSTEM WILL COMBINE WITH
COMPRESSIONAL WARMING TO PRODUCE TEMPERATURES NEAR 80 ACROSS
PORTIONS OF WESTERN AND SOUTHERN NORTH DAKOTA.
A POTENT SYSTEM IS TAKING AIM ON THE NORTHERN PLAINS FOR SATURDAY
AND SUNDAY. MODELS ARE IN SURPRISINGLY GOOD AGREEMENT WITH TIMING
AND PLACEMENT OF PRECIPITATION. THEREFORE...THUNDERSTORMS AND
WIDESPREAD RAINFALL APPEAR LIKELY AS A STACKED LOW DEVELOPS OVER
SOUTH DAKOTA. AT THIS TIME IT APPEARS PRECIPITATION AMOUNTS NEAR
AN INCH ARE POSSIBLE ACROSS PORTIONS OF SOUTHERN NORTH DAKOTA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 638 AM CDT THU APR 21 2016
VFR CONDITIONS ARE FORECAST FOR THE 12 UTC TAF CYCLE AS COOL HIGH
PRESSURE BUILDS ACROSS NORTH DAKOTA TODAY IN THE WAKE OF A COLD
FRONT OVERNIGHT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JJS
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1159 PM EDT FRI APR 22 2016
.SYNOPSIS...
A COLD FRONT WILL CONTINUE TO PUSH THROUGH SOUTHERN PA
TONIGHT...EXITING DURING THE MIDDLE OF THE NIGHT. HIGH PRESSURE
WILL BUILD INTO THE REGION THIS WEEKEND. ANOTHER COLD FRONT IS
LIKELY TO PUSH ACROSS THE AREA MONDAY NIGHT INTO TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
10PM EDT...DROUGHT BEGETTING DROUGHT LOCALLY IN HAPPY VALLEY.
JUST A PALTRY 0.01 ON THE ROOF TODAY. MANY LOCATIONS ACROSS THE SC
MTNS AND RIDGE AND VALLEY REGION =BETWEEN UNV AND MDT= ARE GETTING
A GOOD SOAKING. ONE REPORT OF ONE INCH - AND PROBABLY MORE BY NOW
- IN MCCONNELLSBURG. TINY POCKETS OF HEAVIER RAIN IN THE FEW TALL
CELLS OUT THERE. VERY LITTLE LTG LEFT NOW. SMALL CLUSTERS OVER DUJ
AND HLG NOW...BUT THESE SHOULD BE DWINDLING WITH THE LOSS OF
HEATING AND INSTABILITY. STILL...THEY WILL CONTINUE SSE AND THERE
COULD BE SOME SHOWERS LINGER OVER THE LAURELS INTO THE WEE HOURS.
THE LARGER AREA OF SHOWERS ARE SUPPORTED BY GOOD DYNAMICS AS
DISCUSSED BELOW. SO THESE SHOULD CONTINUE THROUGH THE NIGHT AND
THE SLOW MOVEMENT WILL KEEP SOME HEAVY RAIN POSSIBLE. WILL HOLD
POPS INTO THE POST-DAWN HOURS FOR RIGHT ALONG THE MD BORDER.
PREV...
WIND SHIFT TO THE NW AT KBFD AND KFKL IN THE LAST HR. SO THE FRONT
MUST BE PUSHING THRU THERE NOW.
HRRR AND RAP NOT HANDLING THE INITIAL AND FIRST HR/TWO OF
QPF AND PLACEMENT OF CONVECTION VERY WELL THIS EVENING. THIS MAY
BE DUE TO THE LIGHT RADAR RETURNS WITH MID CLOUDS AHEAD OF THE
MAIN AREA OF SCT SHRA BEING INGESTED INTO THE MODEL INITS. SHOWERS
IN THE NORTH ARE UNDERDONE AND IN THE SOUTH ARE OVERDONE. IN ANY
CASE...THE SHOWERS ARE MOVING SLOWLY...BUT THE RADAR ESTIMATES ARE
VERY LOW SAVE FOR SOME PINPRICKS OF >0.25IN IN THE THE ONE HR
ESTIMATES. PWATS ARE NOT THAT HIGH...AND ARE ONLY A LITTLE HIGHER
THAN NORMAL FOR LATE APRIL. VERY LITTLE ICE IN THEM AND THUS
LITTLE LIGHTNING. JUST ENOUGH LTG TO KEEP MENTIONS OF IT IN THE
FCST. WILL CARRY ON WITH HIGH POPS IN THE SE FOR THE LATE EVENING
AND EARLY TONIGHT.
PREV PREV...
A DISTINCT AREA OF LLVL RIDGING HELPED TO BRING MAINLY DRY
CONDITIONS ACROSS MUCH OF CENTRAL PENN TODAY BENEATH AN OVC LAYER
OF THICK ALTO CU AND ALTO/CIRROSTRATUS CLOUDS. AN AREA OF SHOWERS
LINKED TO THE NOSE OF A 30-40 KT SWRLY LLJ WAS SLIDING ACROSS OUR
EXTREME SERN COUNTIES ATTM...WHILE A SECOND AREA OF SCATTERED
SHOWERS /ASSOCIATED WITH THE LEFT EXIT REGION OF A SOUTHERLY UPPER
JETLET JUST AHEAD OF THE SFC COLD FRONT/ WAS AFFECTING THE NRN
MTNS AND WRN PLATEAU OF PENN..
MIXED LAYER CAPE WILL INCREASE TO 200-500 J/KG ACROSS SOUTHERN AND
WESTERN PARTS OF THE FCST AREA LATE THIS AFTERNOON AND
EVENING /WITH SOME POCKETS OF CAPE APPROACHING 1000 J/KG
POSSIBLE/. THIS MODEST INCREASE IN INSTAB AHEAD OF THE COLD FRONT
WILL SUPPORT THE DEVELOPMENT OF ISOLATED HEAVIER SHOWERS AND A
FEW LOW-TOPPED TSRA...MAINLY NEAR AND WEST OF RT 219 AND TO THE
SOUTH OF THE RT 22/322 CORRIDOR.
TEMPS AT 18Z ARE NEARING THEIR FORECAST HIGHS /SEVERAL DEG ABV
CLIMO/...IN THE LOWER TO MID 60S ACROSS THE NRN AND WRN MTNS...AND
UPPER 60S TO LOWER 70S ELSEWHERE ACROSS CENTRAL AND SERN PA.
AS THE COLD FRONT SLIDES SE ACROSS THE ALLEGHENIES AND INTO
CENTRAL PENN LATER THIS EVENING THROUGH ABOUT 06Z...THE TIMING
SHOULD COINCIDE NICELY WITH THE EWD PROGRESSION OF AN AREA OF
STRONG UPPER DIFFLUENCE/UVVEL JUST AHEAD OF THE COMPACT UPPER
TROUGH SEEN OVER OHIO LATE THIS AFTERNOON. HRRR AGREES WITH THIS
SCENARIO AND PAINTS OF FEW SMALL AREAS OF ENHANCED CONVECTION AND
QPF OVER THE SOUTHERN HALF TO TWO THIRDS OF THE CWA. ALTHOUGH A
FEW RUMBLES OF THUNDER CAN/T BE RULED OUT...SCATTERED MDT TO
BRIEFLY HEAVY SHRA WILL LIKELY BE THE DOMINANT FORM OF CONVECTION
THIS EVENING AND TONIGHT. ADDITIONAL RAINFALL RANGING FROM 1-2
TENTHS ACROSS THE REGION NORTH OF I-80...AND UP TO 3 TENTHS OF AN
INCH IN THE SOUTH STILL LOOKS IN GOOD SHAPE FORECAST-WISE BASED ON
THE PAST SEVERAL RUNS OF THE HRRR...THE LATEST SREF AND GEFS...AND
12Z OPER MODELS.
WINDS WILL BE VERY LIGHT AND VARIABLE IN DIRECTION TO START THE
AFTERNOON...THEN BECOME SOUTHWESTERLY AT 5 TO 8 KTS LATER THIS
AFTERNOON/EVENING JUST AHEAD OF THE CFRONT.
AFTER THE CFROPA LATE TONIGHT AND EARLY SATURDAY...LLVL WINDS WILL
BLOW FROM 340-010 DEG...WITH SOME GUSTS INTO THE MID AND UPPER
TEENS BY LATE SAT MORNING. A PERIOD OF LOW STRATUS/STRATOCU
APPEARS LIKELY LATE TONIGHT THROUGH 14-16Z SAT /ESP ACROSS THE
NRN AND WRN MTNS OF PENN/.
LOW TEMPS EARLY SATURDAY WILL VARY FROM THE U30S NW TO LOWER 50S
IN THE SE.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
CAN/T RULE OUT A FEW LINGERING SHOWERS LASTING THRU LATE SAT AM
ACROSS THE LOWER SUSQ VALLEY. THE MAIN FCST PROBLEM FOR LATER
SATURDAY MORNING WILL SURROUND THE EXTENT OF LOW CLOUDS...AND
TIMING OF THEIR DISSIPATION.
THE ARRIVAL OF HIGH PRESSURE AND DRIER NNW FLOW SHOULD BRING
MSUNNY SKIES TO THE ENTIRE AREA BY SAT AFTN. SUPERBLEND TEMPS
LOOKING SEASONABLE SAT...FROM THE U50S NW MTNS TO M-U60S SE
COUNTIES.
THE WIND WILL AVERAGE 10-15 KTS WITH SOME GUSTS IN THE UPPER TEENS
LIKELY CENTRAL AND WESTERN PENN. SUSTAINED AND PEAK GUSTS
NORTHERLY WIND GUSTS COULD BE 5-8 KTS HIGHER ACROSS THE EAST
WHERE LLVL P-GRADIENT IS THE TIGHTEST AHEAD OF HIGH PRESSURE OVER
THE GLAKES REGION. LATER SHIFTS MAY HAVE TO CONSIDER/COLLABORATE
WITH SURROUNDING WFOS A FIRE WEATHER WATCH OR RED FLAG WARNING FOR
SATURDAY SHOULD RAINFALL AMOUNTS BE LESS THAN CURRENTLY FCST.
HIGH PRESSURE WILL BECOME CENTERED OVER THE REGION SATURDAY NIGHT
WITH CLEAR SKIES...LOW PWATS AND NEARLY CALM AIR. INCLUDED PATCHY
FROST ACROSS THE MTNS NEAR THE I-80 CORRIDOR AND LARGER AREAS OF
FROST ACROSS THE NRN MTNS. HOWEVER...THIS AREA OF THE STATE IS
STILL OUTSIDE OF THE BEGINNING OF THE GROWING SEASON. A LOW PROB
FOR A FROST ADVISORY IS IN THE EAST/WEST SLIVER OF COUNTIES JUST
ALONG AND JUST SOUTH OF I-80 WHERE THE OFFICIAL START TO THE
GROWING SEASON WAS THURSDAY/APRIL 21ST.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
GUIDANCE HAS BEEN CONSISTENT IN SHOWING THE BROAD
TROUGH/RIDGE/TROUGH CONFIGURATION EXTENDING FROM THE GREAT BASIN
TO THE PLAINS INTO THE MID ATLANTIC REGION AT THE START OF THE
LONG TERM PERIOD TRANSITIONING TOWARD A MEAN WESTERN
TROUGH/BUILDING RIDGE IN THE EAST THRU NEXT WEEK. UNCERTAINTY HAS
ALSO DECREASED OVER THE POSITION OF AN EAST/WEST SFC FRONTAL
BOUNDARY AND LOW LEVEL BAROCLINIC ZONE WITH COLDER TEMPERATURES
STAYING WELL TO THE NORTH OF PA ALONG THE NRN TIER STATES/CANADIAN
BORDER.
THE WEEKEND AS A WHOLE LOOKS FAIR AND DRY WITH A RISK OF
FROST/FREEZE CONDITIONS SATURDAY NIGHT INTO SUNDAY MORNING. WAVES
OF LOW PRESSURE MOVG EWD ALONG WAVY SFC FRONTAL BOUNDARY PRESSING
SWD FROM THE LOWER LAKES/UPSTATE NY SHOULD BRING PERIODS OF RAIN
EARLY NEXT WEEK BUT CONFIDENCE IN EXACT TIMING OF GREATEST PCPN
RISK IS STILL BELOW AVERAGE AND COULD EASILY SHIFT +/- 12 HOURS.
MODEL CONSENSUS FAVORS A DRY PERIOD ON WEDNESDAY BEFORE RAIN PROBS
TREND HIGHER FROM WEST TO EAST INTO THE SECOND HALF OF NEXT WEEK.
ASIDE FROM A CHILLY SUNDAY MORNING...THE GLOBAL ENSEMBLE MEANS
ALONG WITH NATIONAL/REGIONAL BLENDS ALL SUPPORT ABOVE NORMAL TEMPS
THROUGH THE MEDIUM RANGE PERIOD.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
SHOWERS CONTINUE TO MOVE TO THE EAST. STILL HAVE A SLIGHT CHANCE
FOR THUNDER BUT HAVE LEFT OUT ANY MENTION OF TSTM IN TAFS. THERE
HAS BEEN LIMITED RESTRICTIONS THROUGH THE EVENING. THOUGH IFR IS
POSSIBLE AT AOO THROUGH 06Z...AND AT MDT...JST AND LNS THROUGH 09Z
AS THE SYSTEM PASSES. THE RESTRICTIONS CONTINUE OVER WESTERN AND
CENTRAL MTNS INTO SAT AS UPPER TROUGH PASSES THROUGH. EXPECT
CONDITIONS TO IMPROVE BETWEEN 13Z TO 15Z AS THE WINDS MIX
DOWN...WITH GUSTY WINDS AND VFR CIGS AND VSBYS THROUGH SATURDAY.
STILL A CHANCE FOR LOW BUT VFR CIGS AT JST.
OUTLOOK...
SAT...AM LOW CIGS W MTNS.
SUN...NO SIG WX EXPECTED.
MON-TUE...PM SHRA DEVELOPING MONDAY AND CONTINUING INTO TUESDAY.
REDUCTIONS POSSIBLE...MAINLY NW PA.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...DANGELO/LAMBERT
SHORT TERM...LAMBERT
LONG TERM...FITZGERALD/GARTNER
AVIATION...LAMBERT/RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1002 PM EDT FRI APR 22 2016
.SYNOPSIS...
A COLD FRONT WILL CONTINUE TO PUSH THROUGH SOUTHERN PA
TONIGHT...EXITING DURING THE MIDDLE OF THE NIGHT. HIGH PRESSURE
WILL BUILD INTO THE REGION THIS WEEKEND. ANOTHER COLD FRONT IS
LIKELY TO PUSH ACROSS THE AREA MONDAY NIGHT INTO TUESDAY.
&&
.NEAR TERM /UNTIL 7 AM SATURDAY MORNING/...
10PM EDT...DROUGHT BEGETTING DROUGHT LOCALLY IN HAPPY VALLEY.
JUST A PALTRY 0.01 ON THE ROOF TODAY. MANY LOCATIONS ACROSS THE SC
MTNS AND RIDGE AND VALLEY REGION =BETWEEN UNV AND MDT= ARE GETTING
A GOOD SOAKING. ONE REPORT OF ONE INCH - AND PROBABLY MORE BY NOW
- IN MCCONNELLSBURG. TINY POCKETS OF HEAVIER RAIN IN THE FEW TALL
CELLS OUT THERE. VERY LITTLE LTG LEFT NOW. SMALL CLUSTERS OVER DUJ
AND HLG NOW...BUT THESE SHOULD BE DWINDLING WITH THE LOSS OF
HEATING AND INSTABILITY. STILL...THEY WILL CONTINUE SSE AND THERE
COULD BE SOME SHOWERS LINGER OVER THE LAURELS INTO THE WEE HOURS.
THE LARGER AREA OF SHOWERS ARE SUPPORTED BY GOOD DYNAMICS AS
DISCUSSED BELOW. SO THESE SHOULD CONTINUE THROUGH THE NIGHT AND
THE SLOW MOVEMENT WILL KEEP SOME HEAVY RAIN POSSIBLE. WILL HOLD
POPS INTO THE POST-DAWN HOURS FOR RIGHT ALONG THE MD BORDER.
PREV...
WIND SHIFT TO THE NW AT KBFD AND KFKL IN THE LAST HR. SO THE FRONT
MUST BE PUSHING THRU THERE NOW.
HRRR AND RAP NOT HANDLING THE INITIAL AND FIRST HR/TWO OF
QPF AND PLACEMENT OF CONVECTION VERY WELL THIS EVENING. THIS MAY
BE DUE TO THE LIGHT RADAR RETURNS WITH MID CLOUDS AHEAD OF THE
MAIN AREA OF SCT SHRA BEING INGESTED INTO THE MODEL INITS. SHOWERS
IN THE NORTH ARE UNDERDONE AND IN THE SOUTH ARE OVERDONE. IN ANY
CASE...THE SHOWERS ARE MOVING SLOWLY...BUT THE RADAR ESTIMATES ARE
VERY LOW SAVE FOR SOME PINPRICKS OF >0.25IN IN THE THE ONE HR
ESTIMATES. PWATS ARE NOT THAT HIGH...AND ARE ONLY A LITTLE HIGHER
THAN NORMAL FOR LATE APRIL. VERY LITTLE ICE IN THEM AND THUS
LITTLE LIGHTNING. JUST ENOUGH LTG TO KEEP MENTIONS OF IT IN THE
FCST. WILL CARRY ON WITH HIGH POPS IN THE SE FOR THE LATE EVENING
AND EARLY TONIGHT.
PREV PREV...
A DISTINCT AREA OF LLVL RIDGING HELPED TO BRING MAINLY DRY
CONDITIONS ACROSS MUCH OF CENTRAL PENN TODAY BENEATH AN OVC LAYER
OF THICK ALTO CU AND ALTO/CIRROSTRATUS CLOUDS. AN AREA OF SHOWERS
LINKED TO THE NOSE OF A 30-40 KT SWRLY LLJ WAS SLIDING ACROSS OUR
EXTREME SERN COUNTIES ATTM...WHILE A SECOND AREA OF SCATTERED
SHOWERS /ASSOCIATED WITH THE LEFT EXIT REGION OF A SOUTHERLY UPPER
JETLET JUST AHEAD OF THE SFC COLD FRONT/ WAS AFFECTING THE NRN
MTNS AND WRN PLATEAU OF PENN..
MIXED LAYER CAPE WILL INCREASE TO 200-500 J/KG ACROSS SOUTHERN AND
WESTERN PARTS OF THE FCST AREA LATE THIS AFTERNOON AND
EVENING /WITH SOME POCKETS OF CAPE APPROACHING 1000 J/KG
POSSIBLE/. THIS MODEST INCREASE IN INSTAB AHEAD OF THE COLD FRONT
WILL SUPPORT THE DEVELOPMENT OF ISOLATED HEAVIER SHOWERS AND A
FEW LOW-TOPPED TSRA...MAINLY NEAR AND WEST OF RT 219 AND TO THE
SOUTH OF THE RT 22/322 CORRIDOR.
TEMPS AT 18Z ARE NEARING THEIR FORECAST HIGHS /SEVERAL DEG ABV
CLIMO/...IN THE LOWER TO MID 60S ACROSS THE NRN AND WRN MTNS...AND
UPPER 60S TO LOWER 70S ELSEWHERE ACROSS CENTRAL AND SERN PA.
AS THE COLD FRONT SLIDES SE ACROSS THE ALLEGHENIES AND INTO
CENTRAL PENN LATER THIS EVENING THROUGH ABOUT 06Z...THE TIMING
SHOULD COINCIDE NICELY WITH THE EWD PROGRESSION OF AN AREA OF
STRONG UPPER DIFFLUENCE/UVVEL JUST AHEAD OF THE COMPACT UPPER
TROUGH SEEN OVER OHIO LATE THIS AFTERNOON. HRRR AGREES WITH THIS
SCENARIO AND PAINTS OF FEW SMALL AREAS OF ENHANCED CONVECTION AND
QPF OVER THE SOUTHERN HALF TO TWO THIRDS OF THE CWA. ALTHOUGH A
FEW RUMBLES OF THUNDER CAN/T BE RULED OUT...SCATTERED MDT TO
BRIEFLY HEAVY SHRA WILL LIKELY BE THE DOMINANT FORM OF CONVECTION
THIS EVENING AND TONIGHT. ADDITIONAL RAINFALL RANGING FROM 1-2
TENTHS ACROSS THE REGION NORTH OF I-80...AND UP TO 3 TENTHS OF AN
INCH IN THE SOUTH STILL LOOKS IN GOOD SHAPE FORECAST-WISE BASED ON
THE PAST SEVERAL RUNS OF THE HRRR...THE LATEST SREF AND GEFS...AND
12Z OPER MODELS.
WINDS WILL BE VERY LIGHT AND VARIABLE IN DIRECTION TO START THE
AFTERNOON...THEN BECOME SOUTHWESTERLY AT 5 TO 8 KTS LATER THIS
AFTERNOON/EVENING JUST AHEAD OF THE CFRONT.
AFTER THE CFROPA LATE TONIGHT AND EARLY SATURDAY...LLVL WINDS WILL
BLOW FROM 340-010 DEG...WITH SOME GUSTS INTO THE MID AND UPPER
TEENS BY LATE SAT MORNING. A PERIOD OF LOW STRATUS/STRATOCU
APPEARS LIKELY LATE TONIGHT THROUGH 14-16Z SAT /ESP ACROSS THE
NRN AND WRN MTNS OF PENN/.
LOW TEMPS EARLY SATURDAY WILL VARY FROM THE U30S NW TO LOWER 50S
IN THE SE.
&&
.SHORT TERM /7 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
CAN/T RULE OUT A FEW LINGERING SHOWERS LASTING THRU LATE SAT AM
ACROSS THE LOWER SUSQ VALLEY. THE MAIN FCST PROBLEM FOR LATER
SATURDAY MORNING WILL SURROUND THE EXTENT OF LOW CLOUDS...AND
TIMING OF THEIR DISSIPATION.
THE ARRIVAL OF HIGH PRESSURE AND DRIER NNW FLOW SHOULD BRING
MSUNNY SKIES TO THE ENTIRE AREA BY SAT AFTN. SUPERBLEND TEMPS
LOOKING SEASONABLE SAT...FROM THE U50S NW MTNS TO M-U60S SE
COUNTIES.
THE WIND WILL AVERAGE 10-15 KTS WITH SOME GUSTS IN THE UPPER TEENS
LIKELY CENTRAL AND WESTERN PENN. SUSTAINED AND PEAK GUSTS
NORTHERLY WIND GUSTS COULD BE 5-8 KTS HIGHER ACROSS THE EAST
WHERE LLVL P-GRADIENT IS THE TIGHTEST AHEAD OF HIGH PRESSURE OVER
THE GLAKES REGION. LATER SHIFTS MAY HAVE TO CONSIDER/COLLABORATE
WITH SURROUNDING WFOS A FIRE WEATHER WATCH OR RED FLAG WARNING FOR
SATURDAY SHOULD RAINFALL AMOUNTS BE LESS THAN CURRENTLY FCST.
HIGH PRESSURE WILL BECOME CENTERED OVER THE REGION SATURDAY NIGHT
WITH CLEAR SKIES...LOW PWATS AND NEARLY CALM AIR. INCLUDED PATCHY
FROST ACROSS THE MTNS NEAR THE I-80 CORRIDOR AND LARGER AREAS OF
FROST ACROSS THE NRN MTNS. HOWEVER...THIS AREA OF THE STATE IS
STILL OUTSIDE OF THE BEGINNING OF THE GROWING SEASON. A LOW PROB
FOR A FROST ADVISORY IS IN THE EAST/WEST SLIVER OF COUNTIES JUST
ALONG AND JUST SOUTH OF I-80 WHERE THE OFFICIAL START TO THE
GROWING SEASON WAS THURSDAY/APRIL 21ST.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
GUIDANCE HAS BEEN CONSISTENT IN SHOWING THE BROAD
TROUGH/RIDGE/TROUGH CONFIGURATION EXTENDING FROM THE GREAT BASIN
TO THE PLAINS INTO THE MID ATLANTIC REGION AT THE START OF THE
LONG TERM PERIOD TRANSITIONING TOWARD A MEAN WESTERN
TROUGH/BUILDING RIDGE IN THE EAST THRU NEXT WEEK. UNCERTAINTY HAS
ALSO DECREASED OVER THE POSITION OF AN EAST/WEST SFC FRONTAL
BOUNDARY AND LOW LEVEL BAROCLINIC ZONE WITH COLDER TEMPERATURES
STAYING WELL TO THE NORTH OF PA ALONG THE NRN TIER STATES/CANADIAN
BORDER.
THE WEEKEND AS A WHOLE LOOKS FAIR AND DRY WITH A RISK OF
FROST/FREEZE CONDITIONS SATURDAY NIGHT INTO SUNDAY MORNING. WAVES
OF LOW PRESSURE MOVG EWD ALONG WAVY SFC FRONTAL BOUNDARY PRESSING
SWD FROM THE LOWER LAKES/UPSTATE NY SHOULD BRING PERIODS OF RAIN
EARLY NEXT WEEK BUT CONFIDENCE IN EXACT TIMING OF GREATEST PCPN
RISK IS STILL BELOW AVERAGE AND COULD EASILY SHIFT +/- 12 HOURS.
MODEL CONSENSUS FAVORS A DRY PERIOD ON WEDNESDAY BEFORE RAIN PROBS
TREND HIGHER FROM WEST TO EAST INTO THE SECOND HALF OF NEXT WEEK.
ASIDE FROM A CHILLY SUNDAY MORNING...THE GLOBAL ENSEMBLE MEANS
ALONG WITH NATIONAL/REGIONAL BLENDS ALL SUPPORT ABOVE NORMAL TEMPS
THROUGH THE MEDIUM RANGE PERIOD.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
COLD FRONT WILL PUSH SLOWLY ACROSS THE REGION LATER TODAY AND
TONIGHT. AHEAD OF THAT...LLJET WILL SWING THROUGH THE SOUTHEASTERN
THIRD OF THE STATE...BRINGING A PLUME OF MOISTURE THROUGH EARLY
THIS AFTERNOON...THAT WILL SUPPORT A FEW AREA OF MAINLY LIGHT
SHOWERS AND BRING CIG REDUCTIONS MAINLY TO WESTERN HALF.
THE AREA OF DRYING AND MAINLY VFR...MID-LEVEL CLOUDS THAT
OCCURRED BEHIND THE DEPARTING LL JET OVER NRN MD AND SERN PENN
WILL TRANSITION TO AN INCREASING THREAT FOR SHOWERS OVER THE WRN
MTNS AFTER 20Z.
THE COLD FRONT AND APPROACHING UPPER LOW WILL BRING NUMEROUS
SHOWERS AND PERHAPS A FEW ISOLATED LATE TODAY/ THIS EVENING
/AND MAINLY OVERNIGHT IN THE SE/...ALONG WITH RESTRICTIONS
RETURNING TO THE WEST AND INTERMITTENT RESTRICTIONS TO THE EAST.
RESTRICTIONS CONTINUE OVER WESTERN AND CENTRAL MTNS INTO SAT AS
UPPER TROUGH PASSES THROUGH.
OUTLOOK...
SAT...AM LOW CIGS W MTNS.
SUN...NO SIG WX EXPECTED.
MON-TUE...PM SHRA DEVELOPING MONDAY AND CONTINUING INTO TUESDAY.
REDUCTIONS POSSIBLE...MAINLY NW PA.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/LAMBERT
NEAR TERM...DANGELO/LAMBERT
SHORT TERM...LAMBERT
LONG TERM...FITZGERALD/GARTNER
AVIATION...LAMBERT/RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
312 PM EDT THU APR 21 2016
.SYNOPSIS...
LOW PRESSURE AND AN ACCOMPANYING FRONTAL SYSTEM WILL MOVE EAST
ACROSS THE MIDWEST AND OHIO VALLEY TOWARD THE REGION TODAY.
SHOWERS SPREADING INTO THE REGION THIS EVENING INTO FRIDAY WILL
BE FOLLOWED BY MILD AND DRY WEATHER THIS WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
MORE EXTENSIVE AND THICKENING MID LEVEL CLOUDS WERE OVERSPREADING
THE CWA LATE TODAY. RADAR ECHOES WERE STILL MAINLY ALOFT...THOUGH
SOME ACROSS THE NW MTNS WITH RETURN AROUND 25 DBZ WERE LIKELY
REACHING THE GROUND AS BRIEF SHOWERS.
LATEST HRRR IS QUITE DRY THROUGH AT LEAST THE FIRST HALF OF
TONIGHT...THOUGH ITS LIKELY A FEW BRIEF SHOWERS WILL STREAK NE
ACROSS THE WESTERN AND NRN MTNS BRINGING SEVERAL HUNDREDTHS TO
PERHAPS ONE-TENTH OF AN INCH OF RAIN AS A WARM FRONT LIFTS NE
ACROSS THE STATE.
THE CLOUDS AND LIGHT SOUTH TO SWRLY LLVL FLOW WILL KEEP TEMPS MILD
OVERNIGHT...MAINLY IN THE MID TO UPPER 50S ACROSS CENTRAL AND SRN
PENN. SOME EVAP COOLING ACROSS THE NWRN ZONES WILL PUSH TEMPS A
LITTLE LOWER...DOWN INTO THE L50S.
&&
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
SFC COLD FRONT WILL APPROACH FROM THE OHIO VALLEY FRIDAY. A PLUME
OF HIGH PWAT AIR /25-30MM/ WILL SLIDE EAST ACROSS THE STATE FRIDAY
AND EXIT THE SE ZONES AFTER 06Z SATURDAY.
FRIDAY LOOKS PRETTY CLOUDY AND SHOWERY WITH POPS IN THE 70-80
PERCENT RANGE. SOME SHORT TERM OPER MODEL GUIDANCE SUGGESTS THAT
MU CAPES WILL RAMP UP TO BETWEEN 500-1000 J/KG DURING THE DAY
FRIDAY...THOUGH THE ENSEMBLE MEAN IS SLIGHTLY LOWER AT A FEW TO
SVRL HUNDRED J/KG - JUST ENOUGH TO MENTION ISOLATED TSRA WHERE
SOME BREAKS IN THE CLOUD COVER DEVELOP.
SOME SHOWERS LINGER FRIDAY NIGHT...MAINLY IN THE S/SE AS THE
UPPER LOW AND REAL COLD AIR ALOFT TAKE UNTIL MIDNIGHT OR SO ON
FRIDAY NIGHT TO PASS COMPLETELY THROUGH.
24-36 HOUR QPF IS STILL SLATED TO HOLD TO ONLY 0.25 INCHES SE TO
PERHAPS AROUND 0.5 INCHES NW. EVEN ACROSS THE NW...THE GEFS AND
SREF PROB FOR 0.50 INCH OF RAIN OVER A 24 HOUR PERIOD IS BARELY
OVER 50 PERCENT. LATEST GEFS MINS FRI NIGHT WILL BE REALLY CLOSE
TO NORMAL ACROSS THE NORTH...AND JUST A HAIR ABOVE THEM IN THE
SOUTH.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
GUIDANCE HAS COME INTO MUCH BETTER AGREEMENT IN THE PATTERN
VERSUS PREVIOUS DAYS...SHOWING A MIGRATION FROM A BROAD
TROUGH/RIDGE/TROUGH CONFIGURATION EXTENDING FROM THE GREAT BASIN
TO THE PLAINS INTO THE MID ATLANTIC REGION AT THE START OF THE
PERIOD...TOWARD A MEAN WESTERN TROUGH/BUILDING RIDGE IN THE EAST
BY NEXT THU AS THE STRONG HIGH LATITUDE BLOCKING WEAKENS OVER
GREENLAND/EASTERN CANADA. UNCERTAINTY HAS ALSO DECREASED OVER THE
POSITION OF AN EAST/WEST SFC FRONTAL BOUNDARY AND LOW LEVEL
BAROCLINIC ZONE WITH COLDER TEMPERATURES STAYING WELL TO THE NORTH
OF PA ALONG THE NRN TIER STATES/CANADIAN BORDER.
THE NCEP MODELS ARE WEAKER AND MORE PROGRESSIVE VS. ECMWF/CMC
WITH THE SHORTWAVE TROUGH EXITING THE MID ATLANTIC EARLY SATURDAY.
THIS MAY LINGER CLOUDS/LIGHT RAIN OVER SOUTHERN AREAS DURING THE
MORNING BEFORE HIGH PRESSURE DRYS THINGS OUT BY THE AFTERNOON.
THE WEEKEND AS A WHOLE LOOKS FAIR AND DRY WITH A RISK OF
FROST/FREEZE CONDITIONS SATURDAY NIGHT INTO SUNDAY MORNING. WAVES
OF LOW PRESSURE MOVG EWD ALONG WAVY SFC FRONTAL BOUNDARY PRESSING
SWD FROM THE LOWER LAKES/UPSTATE NY SHOULD BRING PERIODS OF RAIN
EARLY NEXT WEEK BUT CONFIDENCE IN EXACT TIMING OF GREATEST PCPN
RISK IS STILL BELOW AVERAGE AND COULD EASILY SHIFT +/- 12 HOURS.
MODEL CONSENSUS FAVORS A DRY PERIOD ON WEDNESDAY BEFORE RAIN PROBS
TREND HIGHER FROM WEST TO EAST INTO THE SECOND HALF OF NEXT WEEK.
ASIDE FROM A CHILLY SUNDAY MORNING...THE GLOBAL ENSEMBLE MEANS
ALONG WITH NATIONAL/REGIONAL BLENDS ALL SUPPORT ABOVE NORMAL TEMPS
THROUGH THE MEDIUM RANGE PERIOD.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
A WARM FRONT LIFTING NORTHEAST INTO THE AREA WILL SPREAD SCT
MAINLY VERY LIGHT SHOWERS INTO THE AREA /MAINLY NEAR AND TO THE
WEST OF A KJST TO KBFD LINE/ LATER TODAY AND TONIGHT.
DRY AIR IN THE LOW LLVLS SHOULD ENSURE VFR CONDS ACROSS THE
ENTIRE AREA THROUGH EARLY THIS EVENING. A BLEND OF LATEST NEAR
TERM MDLS SUGGESTS A BRIEFLY HEAVIER SHOWERS ARE POSSIBLE LATE
TODAY AND TONIGHT ACROSS THE NRN AND WRN MTNS WITH BRIEF VISBY
REDUCTIONS. THE BEST CHC FOR SHOWERS WILL ARRIVE FROM WEST TO EAST
DURING THE MID TO LATE MORNING HOURS FRIDAY...WITH ISOLATED TSRA
IMPACTS POSSIBLE BETWEEN 17-23Z FRIDAY.
OUTLOOK...
FRI...SHOWERS WITH AREAS OF MVFR CIGS AND BRIEF MVFR VSBYS
POSSIBLE /MAINLY ACROSS THE WRN MTNS/. ISOLATED TO SCT PM TSRA
IMPACTS POSSIBLE.
SAT...EARLY AM LOW CIGS POSSIBLE W MTNS.
SUN...NO SIG WX EXPECTED.
MON AND TUESDAY...PM SHRA DEVELOPING MONDAY AND CONTINUING INTO
TUESDAY. REDUCTIONS POSSIBLE...MAINLY NW PA.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...LAMBERT
LONG TERM...STEINBUGL
AVIATION...LAMBERT
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
217 PM EDT THU APR 21 2016
.SYNOPSIS...
LOW PRESSURE AND AN ACCOMPANYING FRONTAL SYSTEM WILL MOVE EAST
ACROSS THE MIDWEST AND OHIO VALLEY TOWARD THE REGION TODAY.
SHOWERS SPREADING INTO THE REGION THIS EVENING INTO FRIDAY WILL
BE FOLLOWED BY MILD AND DRY WEATHER THIS WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
VARYING AMOUNTS OF MID LEVEL CLOUDS WERE SPREADING EAST ACROSS THE
STATE LATE THIS MORNING. ANY RADAR RETURNS ARE WEAK WITH RAIN
EVAPORATING ABOUT 6-8 KFT AGL..IN THE DRY LOW TO MID LEVEL AIR.
TEMPS ARE RUNNING RIGHT ON TRACK WITH HOURLY GRIDDED DATA AND ON
TRACK TO REACH HIGHS IN THE U60S ACROSS THE NRN MTNS...AND LOWER
TO MID 70S ELSEWHERE.
LAST FEW RUNS OF THE HRRR HAVE SHOWN A SLIGHTLY BETTER CHC AND
EARLIER ONSET TIME FOR SCATTERED SHOWERS ACROSS WESTERN AND
CENTRAL PENN LATER THIS AFTERNOON /WEST/ AND EARLY THIS EVENING
/CENTRAL MTNS AND MID SUSQ VALLEY/. STILL...QPF THROUGH THE FIRST
HALF OF TONIGHT SHOULD BE LIGHT AND UNDER ONE TENTH OF AN INCH IN
MOST PLACES...WITH THE EXCEPTION OF THE NW MTNS THAT COULD SEE
AROUND 2 TENTHS OF AN INCH BY 06Z FRIDAY.
WINDS WILL BE SOUTHERLY...AND MAY BE 10-12MPH IN THE SE LATER IN
THE DAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
UPPER LOW OVER THE PLAINS WILL OPEN UP A BIT AND JOIN UP WITH THE
LONG-WAVE TROUGH DROPPING INTO ERN CANADA. THE MOISTURE FEED GETS
BETTER TONIGHT AND FRIDAY...BUT THE UPPER LOW TAKES UNTIL FRI
EVENING/NIGHT TO MOVE OVERHEAD. THE SYSTEM SEEMS TO BE A LITTLE
SLOWER IN PASSING THAN IT APPEARED IN PREVIOUS DAYS. THE SFC LOW
STAYS WELL TO OUR NORTH AS IT OCCLUDES.
SHOWERS WILL BE SPOTTY OVERNIGHT AND HELD MAINLY TO THE NW
HALF/THIRD OF THE AREA. HOWEVER...A STRAY SHOWER MAY ESCAPE INTO
THE EAST. A VERY LOW POP IS WARRANTED FOR THE SE TONIGHT.
FRIDAY LOOKS PRETTY CLOUDY AND SHOWERY. TEMPS WILL STILL BE MILD
DUE TO THE MILD START AND CLOUD COVER. BUT MAXES WILL HOLD A
LITTLE CLOSER TO NORMS FRIDAY THAN THURS - AND MANY PREV DAYS.
THE FORCING WITH THIS SYSTEM IS NEBULOUS AND UPLIFT IS NOT VERY
ORGANIZED. WILL KEEP POPS LOWER THAN CATEGORICAL DUE TO THE
EXPECTED COVERAGE...WHICH SHOULD EVENTUALLY GET EVERY LOCATION
WET. BUT 100POPS SEEMS LIKE OVERKILL FOR THE LARGE BREAKS IN
BETWEEN THE NUMEROUS SHOWERS. FRIDAY NIGHT LOOKS LIKE IT COULD
STILL HOLD SOME SHOWERS...ESP IN THE S/SE AS THE UPPER LOW AND
REAL COLD AIR TAKE UNTIL MIDNIGHT OR SO ON FRIDAY NIGHT TO PASS
COMPLETELY THROUGH. PWATS IN THE 1 TO 1.25 INCH RANGE DO LAST FOR
ABOUT 24 HRS. BUT WITHOUT GOOD EASTERLY/OFF-ATLANTIC FLOW AND ONLY
QUESTIONABLE/DISORGANIZED FORCING...QPF IS STILL SLATED TO HOLD
TO ONLY 0.25 INCHES SE TO 0.6 INCHES NW. MINS FRI NIGHT WILL BE
REALLY CLOSE TO NORMALS NORTH AND JUST A HAIR ABOVE THEM IN THE
SOUTH.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
GUIDANCE HAS COME INTO MUCH BETTER AGREEMENT IN THE PATTERN
VERSUS PREVIOUS DAYS...SHOWING A MIGRATION FROM A BROAD
TROUGH/RIDGE/TROUGH CONFIGURATION EXTENDING FROM THE GREAT BASIN
TO THE PLAINS INTO THE MID ATLANTIC REGION AT THE START OF THE
PERIOD...TOWARD A MEAN WESTERN TROUGH/BUILDING RIDGE IN THE EAST
BY NEXT THU AS THE STRONG HIGH LATITUDE BLOCKING WEAKENS OVER
GREENLAND/EASTERN CANADA. UNCERTAINTY HAS ALSO DECREASED OVER THE
POSITION OF AN EAST/WEST SFC FRONTAL BOUNDARY AND LOW LEVEL
BAROCLINIC ZONE WITH COLDER TEMPERATURES STAYING WELL TO THE NORTH
OF PA ALONG THE NRN TIER STATES/CANADIAN BORDER.
THE NCEP MODELS ARE WEAKER AND MORE PROGRESSIVE VS. ECMWF/CMC
WITH THE SHORTWAVE TROUGH EXITING THE MID ATLANTIC EARLY SATURDAY.
THIS MAY LINGER CLOUDS/LIGHT RAIN OVER SOUTHERN AREAS DURING THE
MORNING BEFORE HIGH PRESSURE DRYS THINGS OUT BY THE AFTERNOON.
THE WEEKEND AS A WHOLE LOOKS FAIR AND DRY WITH A RISK OF
FROST/FREEZE CONDITIONS SATURDAY NIGHT INTO SUNDAY MORNING. WAVES
OF LOW PRESSURE MOVG EWD ALONG WAVY SFC FRONTAL BOUNDARY PRESSING
SWD FROM THE LOWER LAKES/UPSTATE NY SHOULD BRING PERIODS OF RAIN
EARLY NEXT WEEK BUT CONFIDENCE IN EXACT TIMING OF GREATEST PCPN
RISK IS STILL BELOW AVERAGE AND COULD EASILY SHIFT +/- 12 HOURS.
MODEL CONSENSUS FAVORS A DRY PERIOD ON WEDNESDAY BEFORE RAIN PROBS
TREND HIGHER FROM WEST TO EAST INTO THE SECOND HALF OF NEXT WEEK.
ASIDE FROM A CHILLY SUNDAY MORNING...THE GLOBAL ENSEMBLE MEANS
ALONG WITH NATIONAL/REGIONAL BLENDS ALL SUPPORT ABOVE NORMAL TEMPS
THROUGH THE MEDIUM RANGE PERIOD.
&&
.AVIATION /17Z THURSDAY THROUGH MONDAY/...
A WARM FRONT LIFTING NORTHEAST INTO THE AREA WILL SPREAD SCT
SHOWERS INTO THE AREA /MAINLY NEAR AND TO THE WEST OF A KJST TO
KBFD LINE/ LATER TODAY.
DRY AIR IN THE LOW LVLS SHOULD ENSURE VFR CONDS ACROSS THE ENTIRE
AREA THROUGH MID AFTERNOON. HOWEVER...A BLEND OF LATEST NEAR TERM
MDLS SUGGEST A HEAVIER SHOWER THIS LATE AFTN OR EARLY EVENING
COULD PRODUCE A BRIEF VIS REDUCTION IN SOME SPOTS. BEST CHC WILL
BE ACROSS THE NW MTNS /KBFD/ AND LEAST CHC ARND KMDT/KLNS.
OUTLOOK...
FRI...SCT PM TSRA IMPACTS POSSIBLE.
SAT...EARLY AM LOW CIGS POSSIBLE W MTNS.
SUN...NO SIG WX EXPECTED.
MON...PM SHRA/REDUCTIONS POSSIBLE...MAINLY NW PA.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/LAMBERT
NEAR TERM...DANGELO/LAMBERT
SHORT TERM...DANGELO
LONG TERM...STEINBUGL
AVIATION...FITZGERALD/LAMBERT
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1128 AM EDT THU APR 21 2016
.SYNOPSIS...
LOW PRESSURE AND AN ACCOMPANYING FRONTAL SYSTEM WILL MOVE EAST
ACROSS THE MIDWEST AND OHIO VALLEY TOWARD THE REGION TODAY.
SHOWERS SPREADING INTO THE REGION THIS EVENING INTO FRIDAY WILL
BE FOLLOWED BY MILD AND DRY WEATHER THIS WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
VARYING AMOUNTS OF MID LEVEL CLOUDS WERE SPREADING EAST ACROSS THE
STATE LATE THIS MORNING. ANY RADAR RETURNS ARE WEAK WITH RAIN
EVAPORATING ABOUT 6-8 KFT AGL..IN THE DRY LOW TO MID LEVEL AIR.
TEMPS ARE RUNNING RIGHT ON TRACK WITH HOURLY GRIDDED DATA AND ON
TRACK TO REACH HIGHS IN THE U60S ACROSS THE NRN MTNS...AND LOWER
TO MID 70S ELSEWHERE.
LAST FEW RUNS OF THE HRRR HAVE SHOWN A SLIGHTLY BETTER CHC AND
EARLIER ONSET TIME FOR SCATTERED SHOWERS ACROSS WESTERN AND
CENTRAL PENN LATER THIS AFTERNOON /WEST/ AND EARLY THIS EVENING
/CENTRAL MTNS AND MID SUSQ VALLEY/. STILL...QPF THROUGH THE FIRST
HALF OF TONIGHT SHOULD BE LIGHT AND UNDER ONE TENTH OF AN INCH IN
MOST PLACES...WITH THE EXCEPTION OF THE NW MTNS THAT COULD SEE
AROUND 2 TENTHS OF AN INCH BY 06Z FRIDAY.
WINDS WILL BE SOUTHERLY...AND MAY BE 10-12MPH IN THE SE LATER IN
THE DAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
UPPER LOW OVER THE PLAINS WILL OPEN UP A BIT AND JOIN UP WITH THE
LONG-WAVE TROUGH DROPPING INTO ERN CANADA. THE MOISTURE FEED GETS
BETTER TONIGHT AND FRIDAY...BUT THE UPPER LOW TAKES UNTIL FRI
EVENING/NIGHT TO MOVE OVERHEAD. THE SYSTEM SEEMS TO BE A LITTLE
SLOWER IN PASSING THAN IT APPEARED IN PREVIOUS DAYS. THE SFC LOW
STAYS WELL TO OUR NORTH AS IT OCCLUDES.
SHOWERS WILL BE SPOTTY OVERNIGHT AND HELD MAINLY TO THE NW
HALF/THIRD OF THE AREA. HOWEVER...A STRAY SHOWER MAY ESCAPE INTO
THE EAST. A VERY LOW POP IS WARRANTED FOR THE SE TONIGHT.
FRIDAY LOOKS PRETTY CLOUDY AND SHOWERY. TEMPS WILL STILL BE MILD
DUE TO THE MILD START AND CLOUD COVER. BUT MAXES WILL HOLD A
LITTLE CLOSER TO NORMS FRIDAY THAN THURS - AND MANY PREV DAYS.
THE FORCING WITH THIS SYSTEM IS NEBULOUS AND UPLIFT IS NOT VERY
ORGANIZED. WILL KEEP POPS LOWER THAN CATEGORICAL DUE TO THE
EXPECTED COVERAGE...WHICH SHOULD EVENTUALLY GET EVERY LOCATION
WET. BUT 100POPS SEEMS LIKE OVERKILL FOR THE LARGE BREAKS IN
BETWEEN THE NUMEROUS SHOWERS. FRIDAY NIGHT LOOKS LIKE IT COULD
STILL HOLD SOME SHOWERS...ESP IN THE S/SE AS THE UPPER LOW AND
REAL COLD AIR TAKE UNTIL MIDNIGHT OR SO ON FRIDAY NIGHT TO PASS
COMPLETELY THROUGH. PWATS IN THE 1 TO 1.25 INCH RANGE DO LAST FOR
ABOUT 24 HRS. BUT WITHOUT GOOD EASTERLY/OFF-ATLANTIC FLOW AND ONLY
QUESTIONABLE/DISORGANIZED FORCING...QPF IS STILL SLATED TO HOLD
TO ONLY 0.25 INCHES SE TO 0.6 INCHES NW. MINS FRI NIGHT WILL BE
REALLY CLOSE TO NORMALS NORTH AND JUST A HAIR ABOVE THEM IN THE
SOUTH.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
THE COLD AIR BEHIND THE SERIES OF FRONTS WHICH MOVE THROUGH
FRIDAY AND FRIDAY NIGHT WILL BE MODIFIED AS IT MOVES THROUGH THE
UPPER PLAINS AND UPPER GREAT LAKES. THUS...TEMPS WILL NOT BE ALL
THAT COLD. MAXES SAT WILL BE JUST A DEG OR TWO COOLER THAN
NORMALS.
THE UPPER RIDGING OVER THE MIDWEST OVER THE WEEKEND WILL BE
SUPPRESSED SOUTHWARD IN THE FIRST HALF OF THE NEW WEEK. AN UPPER
LOW RIDING OVER THE RIDGE MON-TUES WILL BRING THE NEXT CHC OF
RAIN. WHAT LOOKS LIKE A POTENT STORM IN THE PLAINS/MIDWEST FILLS
AS THE UPPER LOW IS CAUGHT IN THE FASTER WESTERLIES. WARM FRONTAL
PRECIP SHOULD STAY TO THE NORTH OF THE AREA MONDAY. AT THIS POINT
THE WETTEST TIME LOOKS TO BE MON NIGHT-TUES. BUT THE PATTERN
REMAINS PROGRESSIVE AND AFTER ANOTHER DAY OR TWO OF HIGH PRESSURE
AND INCREASING TEMPS...ANOTHER SHOT AT RAIN WILL COME FOR THE
LATTER PART OF NEXT WEEK.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
A WARM FRONT LIFTING NORTHEAST INTO THE AREA WILL SPREAD SCT
SHOWERS INTO THE AREA /MAINLY NEAR AND TO THE WEST OF A KJST TO
KBFD LINE/ LATER TODAY.
DRY AIR IN THE LOW LVLS SHOULD ENSURE VFR CONDS ACROSS THE ENTIRE
AREA THROUGH MID AFTERNOON. HOWEVER...A BLEND OF LATEST NEAR TERM
MDLS SUGGEST A HEAVIER SHOWER THIS LATE AFTN OR EARLY EVENING
COULD PRODUCE A BRIEF VIS REDUCTION IN SOME SPOTS. BEST CHC WILL
BE ACROSS THE NW MTNS /KBFD/ AND LEAST CHC ARND KMDT/KLNS.
OUTLOOK...
FRI...SCT PM TSRA IMPACTS POSSIBLE.
SAT...EARLY AM LOW CIGS POSSIBLE W MTNS.
SUN...NO SIG WX EXPECTED.
MON...PM SHRA/REDUCTIONS POSSIBLE...MAINLY NW PA.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...DANGELO
LONG TERM...DANGELO
AVIATION...FITZGERALD/LAMBERT
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
242 AM EDT THU APR 21 2016
.SYNOPSIS...
LOW PRESSURE AND AN ACCOMPANYING FRONTAL SYSTEM WILL MOVE EAST
ACROSS THE OHIO VALLEY TOWARD THE REGION TODAY. RAIN LATER TODAY
INTO FRIDAY WILL BE FOLLOWED BY MILD AND DRY WEATHER THIS
WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
20 DEWPOINTS THE BIG STORY AND ANY RAIN APPROACHING FROM THE WEST
WILL HAVE TO DO QUITE A BIT OF MOISTENING TO THE LOWER ATMOSPHERE
BEFORE IT WOULD REACH THE GROUND. HAVE DELAYED THE ONSET OF SHRA
IN THE WEST TO VERY LATE MORNING AND EARLY AFTN IN LINE WITH THE
CONCEPTUAL/HUMAN MODEL...AND THE LATEST HRRR AND RAP. TEMPS MAY
DIP INTO THE 30S IN THE EASTERN VALLEYS WHERE THERE IS LESS WIND.
MOST OTHER PLACES WILL SEE TEMPS STAY MILD THRU SUNRISE. WE
SHOULD ALSO TEMPS RISE INTO THE U60S-L70S.
&&
.SHORT TERM /TONIGHT THROUGH 6 PM FRIDAY/...
MODELS IN REASONABLY GOOD AGREEMENT SHOWING TWO WAVES OF SHOWERS
THURSDAY AND FRIDAY AS A LONG WAVE TROUGH MOVES EAST FROM
THE MIDWEST TOWARD THE MID-ATLANTIC. THE FIRST WAVE OF SHOWERS
WILL BE ASSOCIATED WITH SOME ISENTROPIC LIFT AHEAD OF A WEAK
SURFACE WAVE TRACKING NORTHEAST UP THE SAINT LAWRENCE VALLEY
THURSDAY INTO THURSDAY EVENING WITH A SURFACE TROUGH EXTENDING
SOUTH ACROSS PENNSYLVANIA. OVERALL FORCING WITH THIS FIRST WAVE
WILL NOT BE VERY IMPRESSIVE BUT SHOULD BE ENOUGH TO TRIGGER A FEW
SHOWERS DURING THE DAY THURSDAY MOVING FROM WEST TO EAST. BEST
CHANCE OF SHOWERS WILL BE OVER THE NORTHWESTERN PART OF PA CLOSEST
TO THE BEST DYNAMICAL FORCING. POPS WILL BE LOWER FARTHER SOUTH
AND EAST TOWARD THE SUSQUEHANNA VALLEY.
BETTER CHANCE FOR SHOWERS WILL BE FRIDAY AS THE MAIN MID-LEVEL LOW
PRESSURE AREA APPROACHES FROM THE MIDWEST. INTERESTING FACTOR
WITH THIS SYSTEM WILL BE THE POTENTIAL FOR SOME MODEST
INSTABILITY TO DEVELOP AHEAD OF THE ASSOCIATED COLD FRONT FRIDAY
AFTERNOON... WHICH COULD RESULT IN SCATTERED THUNDERSTORMS ALONG
WITH THE SHOWERS. AT THIS POINT ANY INSTABILITY LOOKS TO BE SMALL
ENOUGH TO KEEP THE SEVERE RISK VERY LOW. LATEST SPC OUTLOOK
CONFIRMS THIS THINKING WITH PA IN A GENERAL THUNDER OUTLOOK BUT
NO SEVERE RISK.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
DRY WEATHER WILL RETURN BEHIND THE COLD FRONT FRIDAY NIGHT. AT THIS
POINT THE WEEKEND LOOKS TO BE DRY WITH SEASONABLY MILD
TEMPERATURES AS HIGH PRESSURE MOVES FROM THE MID-WEST OVER THE
MID- ATLANTIC. NEXT WEATHER SYSTEM WILL APPROACH FROM THE MIDWEST
EARLY NEXT WEEK WITH A CHANCE OF SHOWERS INCREASING MONDAY
THROUGH TUESDAY. TEMPERATURES WILL TREND COOLER BY TUESDAY AS A
DEVELOPING GREENLAND BLOCK FORCES UPPER LEVEL LOW PRESSURE OVER
QUEBEC WHICH WILL DRIVE A COOL AIRMASS SOUTHEAST FROM CANADA
TOWARD THE NORTHEAST U.S.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
HIGH PRESSURE AND ASSOC DRY AIR MASS OVER THE REGION WILL ENSURE
VFR CONDS AND LIGHT WINDS FOR THE BALANCE OF THE NIGHT. AN
APPROACHING COLD FRONT WILL SPREAD SCT SHOWERS INTO THE WESTERN
HALF OF PA LATE THIS MORNING THRU THIS EVENING. ALTHOUGH
WIDESPREAD VFR CONDS WILL PREVAIL...BRIEF REDUCTIONS ARE POSSIBLE
IN PASSING SHOWERS FROM KAOO TO KIPT AND POINTS NWRD.
OUTLOOK...
FRI...SCT PM TSRA IMPACTS POSSIBLE.
SAT...EARLY AM LOW CIGS POSSIBLE W MTNS.
SUN...NO SIG WX EXPECTED.
MON...PM SHRA/REDUCTIONS POSSIBLE...MAINLY NW PA.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...STEINBUGL
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
150 AM EDT THU APR 21 2016
.SYNOPSIS...
LOW PRESSURE AND AN ACCOMPANYING FRONTAL SYSTEM WILL MOVE EAST
ACROSS THE OHIO VALLEY TOWARD THE REGION TODAY. RAIN LATER TODAY
INTO FRIDAY WILL BE FOLLOWED BY MILD AND DRY WEATHER THIS
WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
20 DEWPOINTS THE BIG STORY AND ANY RAIN APPROACHING FROM THE WEST
WILL HAVE TO DO QUITE A BIT OF MOISTENING TO THE LOWER ATMOSPHERE
BEFORE IT WOULD REACH THE GROUND. HAVE DELAYED THE ONSET OF SHRA
IN THE WEST TO VERY LATE MORNING AND EARLY AFTN IN LINE WITH THE
CONCEPTUAL/HUMAN MODEL...AND THE LATEST HRRR AND RAP. TEMPS MAY
DIP INTO THE 30S IN THE EASTERN VALLEYS WHERE THERE IS LESS WIND.
MOST OTHER PLACES WILL SEE TEMPS STAY MILD THRU SUNRISE. WE
SHOULD ALSO TEMPS RISE INTO THE U60S-L70S.
&&
.SHORT TERM /TONIGHT THROUGH 6 PM FRIDAY/...
MODELS IN REASONABLY GOOD AGREEMENT SHOWING TWO WAVES OF SHOWERS
THURSDAY AND FRIDAY AS A LONG WAVE TROUGH MOVES EAST FROM
THE MIDWEST TOWARD THE MID-ATLANTIC. THE FIRST WAVE OF SHOWERS
WILL BE ASSOCIATED WITH SOME ISENTROPIC LIFT AHEAD OF A WEAK
SURFACE WAVE TRACKING NORTHEAST UP THE SAINT LAWRENCE VALLEY
THURSDAY INTO THURSDAY EVENING WITH A SURFACE TROUGH EXTENDING
SOUTH ACROSS PENNSYLVANIA. OVERALL FORCING WITH THIS FIRST WAVE
WILL NOT BE VERY IMPRESSIVE BUT SHOULD BE ENOUGH TO TRIGGER A FEW
SHOWERS DURING THE DAY THURSDAY MOVING FROM WEST TO EAST. BEST
CHANCE OF SHOWERS WILL BE OVER THE NORTHWESTERN PART OF PA CLOSEST
TO THE BEST DYNAMICAL FORCING. POPS WILL BE LOWER FARTHER SOUTH
AND EAST TOWARD THE SUSQUEHANNA VALLEY.
BETTER CHANCE FOR SHOWERS WILL BE FRIDAY AS THE MAIN MID-LEVEL LOW
PRESSURE AREA APPROACHES FROM THE MIDWEST. INTERESTING FACTOR
WITH THIS SYSTEM WILL BE THE POTENTIAL FOR SOME MODEST
INSTABILITY TO DEVELOP AHEAD OF THE ASSOCIATED COLD FRONT FRIDAY
AFTERNOON... WHICH COULD RESULT IN SCATTERED THUNDERSTORMS ALONG
WITH THE SHOWERS. AT THIS POINT ANY INSTABILITY LOOKS TO BE SMALL
ENOUGH TO KEEP THE SEVERE RISK VERY LOW. LATEST SPC OUTLOOK
CONFIRMS THIS THINKING WITH PA IN A GENERAL THUNDER OUTLOOK BUT
NO SEVERE RISK.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
DRY WEATHER WILL RETURN BEHIND THE COLD FRONT FRIDAY NIGHT. AT THIS
POINT THE WEEKEND LOOKS TO BE DRY WITH SEASONABLY MILD
TEMPERATURES AS HIGH PRESSURE MOVES FROM THE MID-WEST OVER THE
MID- ATLANTIC. NEXT WEATHER SYSTEM WILL APPROACH FROM THE MIDWEST
EARLY NEXT WEEK WITH A CHANCE OF SHOWERS INCREASING MONDAY
THROUGH TUESDAY. TEMPERATURES WILL TREND COOLER BY TUESDAY AS A
DEVELOPING GREENLAND BLOCK FORCES UPPER LEVEL LOW PRESSURE OVER
QUEBEC WHICH WILL DRIVE A COOL AIRMASS SOUTHEAST FROM CANADA
TOWARD THE NORTHEAST U.S.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
UPDATED AT 03Z... VFR WITH CLEAR SKIES THROUGH THIS EVENING.
INCREASING MID AND HIGH CLOUDS LATE TONIGHT THROUGH THURSDAY
MORNING WITH CIGS AOA 10 KFT. SCATTERED SHOWERS DEVELOPING
THURSDAY AFTERNOON MAINLY AT BFD/JST/AOO/UNV WITH LOCALIZED MVFR
CONDITIONS POSSIBLE. HAVE INCREASED CIGS TO BROKEN BUT LEFT THEM
VFR THROUGH 00Z.
OUTLOOK...
THU NGT - FRI...SHRA/RESTRICTIONS POSSIBLE.
SAT-SUN...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...STEINBUGL
AVIATION...CERU/MARTIN
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
321 AM EDT THU APR 21 2016
.SYNOPSIS...
PRECIPITATION CHANCES INCREASE THRU FRIDAY AS A SECOND COLD FRONT
MOVES IN FROM THE WEST...ALTHOUGH RAINFALL AMOUNTS ARE EXPECTED
TO REMAIN LIGHT. FOLLOWING THE FRONTAL PASSAGE ON SATURDAY...DRY
AND WARM HIGH PRESSURE WILL BUILD IN ACROSS THE FORECAST AREA FOR
SUNDAY. THE HIGH WILL SLIDE OFFSHORE EARLY MONDAY IN ADVANCE OF
ANOTHER WEAK FRONT AND CHANCE FOR LIGHT PRECIPITATION TUESDAY AND
WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM...A SHALLOW WEDGE OF HIGH PRESSURE PERSISTS OVER MOST
OF THE AREA...THE HIGH BEING CENTERED OFF THE MID-ATLANTIC COAST
AND DRIFTING SOUTH. AN AREA OF LOW STRATUS WILL PERSIST THRU THE
MORNING OVER THE ERN HALF OF THE CWFA AS MOIST LOW LEVEL FLOW
OCCURS OVER THE WEDGE.
AFTER DAYBREAK...AS THE HIGH BECOMES CENTERED OFF THE OUTER
BANKS...THE FLOW WILL VEER AND THE LOW LEVEL THERMAL GRADIENT
WILL WEAKEN. THIS WILL ALLOW THE STRATUS TO DISSOLVE. SKIES
TODAY ARE EXPECTED TO BE PARTLY TO MOSTLY SUNNY WITH MAINLY
PATCHY CIRRUS. MEANWHILE...LOW PRESSURE WILL MOVE EWD THRU THE
MISSISSIPPI VALLEY. THE ASSOCIATED UPPER TROUGH WILL BEGIN TO
DISPLACE THE INCUMBENT RIDGE OVER OUR AREA LATE IN THE DAY. AT
THAT TIME PREFRONTAL WAA WILL BEGIN TO INCREASE OVER THE MTNS. WITH
TEMPS WARMING A CATEGORY OR SO ABOVE NORMAL...AND WITH LAPSE RATES
BECOMING A BIT MORE FAVORABLE...A FEW SHOWERS OR LOW-TOPPED TSTMS
ARE POSSIBLE MAINLY OVER SW NC.
GFS AND NAM QPF SUGGEST THERE MAY BE A ROUND OF LIGHT PRECIP
ASSOCIATED WITH WARM CONVEYOR BELT THAT PROGRESSES ACRS THE AREA
DURING THE FIRST HALF OF THE NIGHT...FOLLOWED BY ANOTHER ROUND
PRECIP INVOF THE COLD FRONT FRIDAY MRNG. ISENTROPIC LIFT IS
SOMEWHAT MURKY WITH THAT FEATURE...SO I EFFECTIVELY ADVERTISE A
GRADUAL INCREASE FROM W TO E...AS MOISTURE DEEPENS AND SHORTWAVE
APPROACHES. WITH INCREASING CLOUDS AND BREEZY CONDITIONS TONIGHT...I
FAVORED THE WARMER TEMP GUIDANCE. MINS WILL BE NEAR 10 DEGREES
ABOVE NORMAL.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 210 AM THURSDAY...AN UPPER LOW AND ITS ASSOCIATED TROUGH MOVE
INTO THE AREA FRIDAY AND ACROSS THE AREA FRIDAY NIGHT. THE
ASSOCIATED COLD FRONT MOVES INTO THE AREA FROM THE WEST FRIDAY THEN
ACROSS AND EAST OF THE AREA FRIDAY NIGHT. LOW LEVEL AND MID LEVEL
FORCING...ALONG WITH UPPER DIVERGENCE...INCREASE ENOUGH TO WARRANT
THE CONTINUED LIKELY POP FOR FRIDAY. INSTABILITY DEVELOPS AS WELL
KEEPING THE POTENTIAL FOR THUNDERSTORMS OVER THE AREA. HOWEVER...
THE INSTABILITY REMAINS WEAK WITH EVEN THE MUCAPE BELOW 1000 J/KG.
GUIDANCE HAS BACKED OFF ON THE INCREASING SHEAR KEEPING IT WEAK OVER
OUR AREA...WITH BETTER SHEAR NORTH AND SOUTH OF THE CWFA. STILL...
GIVEN THE COMBINATION OF FORCING AND INSTABILITY AND FAVORABLE
TIMING...AN ISOLATED SEVERE STORM CANNOT BE RULED OUT...BUT THE
CHANCE REMAINS VERY LOW. CHANCE OF EXCESSIVE QPF REMAINS QUITE LOW
AS WELL. GIVEN THE RECENT DRY CONDITIONS...MODERATE RAINFALL WOULD
BE VERY WELCOME. PRECIP TAPERS OFF FRIDAY NIGHT AS THE FRONT MOVES
EAST OF THE AREA. HIGHS WILL BE A FEW DEGREES ABOVE NORMAL WITH LOWS
5 TO 10 DEGREES ABOVE.
DRY CONDITIONS AND CLEARING SKIES RETURN SATURDAY AS HIGH PRESSURE
BUILDS BACK INTO THE AREA. HIGHS WILL BE AROUND 5 DEGREES ABOVE
NORMAL WITH LOWS 5 TO 10 DEGREES ABOVE.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 310 AM THURSDAY...A PROGRESSIVE PATTERN SETS UP FOR THE MEDIUM
RANGE. UPPER RIDGE AXIS CROSSES THE AREA SUNDAY...WITH WEAK SHORT
WAVE ENERGY MOVING THROUGH MONDAY. FLOW REMAINS ZONAL OVER THE AREA
TUESDAY AS A SHORT WAVE PASSES BY TO OUR NORTH...WITH YET ANOTHER
RIDGE AXIS MOVING THROUGH ON WEDNESDAY. AT THE SURFACE...HIGH
PRESSURE OVER THE AREA SUNDAY SLIDES EAST MONDAY WITH SOUTH TO
SOUTHWESTERLY FLOW DEVELOPING. THE GFS SHOWS SOME SHOWERS DEVELOPING
ACROSS THE MOUNTAINS MONDAY...BUT KEPT THE FORECAST DRY IN LINE WITH
THE ECMWF AND CANADIAN. THE TUESDAY SHORT WAVE MOVES A SURFACE LOW
ACROSS THE MID-ATLANTIC WHICH DRAGS A COLD FRONT SOUTH TOWARD OUR
AREA. THE GFS MOVES THE FRONT INTO OUR AREA FASTER THAN THE ECMWF
AND CANADIAN. THE ECMWF DOES MOVE THE FRONT INTO THE AREA WEDNESDAY
WHILE THE GFS STALLS THE FRONT ACROSS THE CAROLINAS. FOLLOWING A
GUIDANCE BLEND BRINGS CHANCE POP INTO THE MOUNTAINS AND I-40
CORRIDOR TUESDAY...THEN ACROSS THE ENTIRE CWFA WEDNESDAY.
HIGHS RISE THROUGH THE PERIOD...REACHING THE MID 80S OUTSIDE OF THE
MTNS TUESDAY...AND AROUND 80 IN THE MOUNTAIN VALLEYS. HIGHS FALL A
FEW DEGREES ON WEDNESDAY. LOWS FOLLOW A SIMILAR TREND...RISING INTO
THE LOW 60S OUTSIDE OF THE MOUNTAINS AND MID 50S MOUNTAIN VALLEYS.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
AT KCLT/KHKY...ATLANTIC MOISTURE FLOWING OVER SHALLOW WEDGE OF HIGH
PRESSURE IS ALREADY PRODUCING MVFR CIGS OVER THE NC PIEDMONT. THE
NAM FAMILY OF MODELS IS HANDLING THE STRATUS MOST ACCURATELY
ATTM...SO USED A CONSENSUS OF NAM AND HRRR FOR CLOUD BASES THRU
THE MRNG. THEY GENERALLY SHOW AT LEAST BKN MVFR PERSISTING UNTIL A
COUPLE HRS AFTER DAYBREAK...AND HINT AT PATCHY IFR AS WELL. WITH
CIGS ALREADY DEVELOPING AND WITH DRY SFC DEWPOINTS...NOT SURE IF
SATURATION WILL OCCUR LOW ENOUGH TO BRING CIGS TO IFR...SO THAT IS
LEFT IN TEMPO. FOLLOWING THE DISSOLUTION OF THE STRATUS...MAINLY
MID-HIGH CLOUDS WILL BE SEEN TODAY. APPROACH OF COLD FRONT FROM THE
WEST TONIGHT WILL REINTRODUCE A LOW VFR DECK THIS EVENING. WINDS
WILL REMAIN SOUTHERLY...AND A FEW LOW-END GUSTS ARE POSSIBLE
THIS AFTN.
ELSEWHERE...MOST GUIDANCE KEEPS THE IFR CIGS EAST OF THE REMAINING
TAF SITES...BUT MVFR SHOULD EXPAND OVER KGSP/KGMU/KAVL BEFORE
DAWN. CAN/T TOTALLY RULE OUT IFR...SO I WILL KEEP AN EYE ON NEARBY
TRENDS AND AMD IF NECESSARY. THIS WILL BE THE MAIN IMPACTFUL WEATHER
THRU THE DAY TODAY...WITH SCT-BKN CIRRUS AND MODEST SOUTHERLY
WINDS. A SMALL CHC OF TSRA EXISTS OVER THE SW NC MTNS...BUT CHC
IS TOO LOW TO MENTION AT KAVL. COLD FRONT WILL BRING BETTER SHRA
CHANCES THIS EVENING FROM WEST TO EAST...HENCE PROB30 AT KAVL. MVFR
CIGS WILL PRECEDE THE FRONT...BUT ONLY KAND IS EXPECTED TO SEE
SUCH PRIOR TO 06Z.
OUTLOOK...RAIN CHANCES INCREASE EARLY FRI AHEAD OF ANOTHER COLD
FRONT APPROACHING THE AREA. HIGH PRESSURE AND MOSTLY VFR CONDITIONS
WILL RETURN SATURDAY FOLLOWING THE DEPARTURE OF THE FRONT.
CONFIDENCE TABLE...
07-13Z 13-19Z 19-01Z 01-06Z
KCLT HIGH 96% HIGH 92% HIGH 100% HIGH 100%
KGSP HIGH 90% HIGH 92% HIGH 100% HIGH 100%
KAVL HIGH 85% HIGH 92% HIGH 100% MED 78%
KHKY HIGH 91% HIGH 89% HIGH 100% HIGH 100%
KGMU HIGH 98% HIGH 98% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 91% HIGH 100% HIGH 88%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULE TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLET HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK:
WWW.WEATHER.GOV/GSP/AVIATION
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...RWH
NEAR TERM...WIMBERLEY
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...WIMBERLEY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
314 AM EDT THU APR 21 2016
.SYNOPSIS...
PRECIPITATION CHANCES INCREASE THRU FRIDAY AS A SECOND COLD FRONT
MOVES IN FROM THE WEST...ALTHOUGH RAINFALL AMOUNTS ARE EXPECTED
TO REMAIN LIGHT. FOLLOWING THE FRONTAL PASSAGE ON SATURDAY...DRY
AND WARM HIGH PRESSURE WILL BUILD IN ACROSS THE FORECAST AREA FOR
SUNDAY. THE HIGH WILL SLIDE OFFSHORE EARLY MONDAY IN ADVANCE OF
ANOTHER WEAK FRONT AND CHANCE FOR LIGHT PRECIPITATION TUESDAY AND
WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM...A SHALLOW WEDGE OF HIGH PRESSURE PERSISTS OVER MOST
OF THE AREA...THE HIGH BEING CENTERED OFF THE MID-ATLANTIC COAST
AND DRIFTING SOUTH. AN AREA OF LOW STRATUS WILL PERSIST THRU THE
MORNING OVER THE ERN HALF OF THE CWFA AS MOIST LOW LEVEL FLOW
OCCURS OVER THE WEDGE.
AFTER DAYBREAK...AS THE HIGH BECOMES CENTERED OFF THE OUTER
BANKS...THE FLOW WILL VEER AND THE LOW LEVEL THERMAL GRADIENT
WILL WEAKEN. THIS WILL ALLOW THE STRATUS TO DISSOLVE. SKIES
TODAY ARE EXPECTED TO BE PARTLY TO MOSTLY SUNNY WITH MAINLY
PATCHY CIRRUS. MEANWHILE...LOW PRESSURE WILL MOVE EWD THRU THE
MISSISSIPPI VALLEY. THE ASSOCIATED UPPER TROUGH WILL BEGIN TO
DISPLACE THE INCUMBENT RIDGE OVER OUR AREA LATE IN THE DAY. AT
THAT TIME PREFRONTAL WAA WILL BEGIN TO INCREASE OVER THE MTNS. WITH
TEMPS WARMING A CATEGORY OR SO ABOVE NORMAL...AND WITH LAPSE RATES
BECOMING A BIT MORE FAVORABLE...A FEW SHOWERS OR LOW-TOPPED TSTMS
ARE POSSIBLE MAINLY OVER SW NC.
GFS AND NAM QPF SUGGEST THERE MAY BE A ROUND OF LIGHT PRECIP
ASSOCIATED WITH WARM CONVEYOR BELT THAT PROGRESSES ACRS THE AREA
DURING THE FIRST HALF OF THE NIGHT...FOLLOWED BY ANOTHER ROUND
PRECIP INVOF THE COLD FRONT FRIDAY MRNG. IN LIGHT OF SOMEWHAT MURKY
ISENTROPIC LIFT...I WILL ADVERTISE A GENERAL INCREASE THRU THE NIGHT
FROM W TO E...AS MOISTURE DEEPENS AND SHORTWAVE APPROACHES. WITH
INCREASING CLOUDS AND BREEZY CONDITIONS TONIGHT...I FAVORED THE
WARMER TEMP GUIDANCE. MINS WILL BE NEAR 10 DEGREES ABOVE NORMAL.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 210 AM THURSDAY...AN UPPER LOW AND ITS ASSOCIATED TROUGH MOVE
INTO THE AREA FRIDAY AND ACROSS THE AREA FRIDAY NIGHT. THE
ASSOCIATED COLD FRONT MOVES INTO THE AREA FROM THE WEST FRIDAY THEN
ACROSS AND EAST OF THE AREA FRIDAY NIGHT. LOW LEVEL AND MID LEVEL
FORCING...ALONG WITH UPPER DIVERGENCE...INCREASE ENOUGH TO WARRANT
THE CONTINUED LIKELY POP FOR FRIDAY. INSTABILITY DEVELOPS AS WELL
KEEPING THE POTENTIAL FOR THUNDERSTORMS OVER THE AREA. HOWEVER...
THE INSTABILITY REMAINS WEAK WITH EVEN THE MUCAPE BELOW 1000 J/KG.
GUIDANCE HAS BACKED OFF ON THE INCREASING SHEAR KEEPING IT WEAK OVER
OUR AREA...WITH BETTER SHEAR NORTH AND SOUTH OF THE CWFA. STILL...
GIVEN THE COMBINATION OF FORCING AND INSTABILITY AND FAVORABLE
TIMING...AN ISOLATED SEVERE STORM CANNOT BE RULED OUT...BUT THE
CHANCE REMAINS VERY LOW. CHANCE OF EXCESSIVE QPF REMAINS QUITE LOW
AS WELL. GIVEN THE RECENT DRY CONDITIONS...MODERATE RAINFALL WOULD
BE VERY WELCOME. PRECIP TAPERS OFF FRIDAY NIGHT AS THE FRONT MOVES
EAST OF THE AREA. HIGHS WILL BE A FEW DEGREES ABOVE NORMAL WITH LOWS
5 TO 10 DEGREES ABOVE.
DRY CONDITIONS AND CLEARING SKIES RETURN SATURDAY AS HIGH PRESSURE
BUILDS BACK INTO THE AREA. HIGHS WILL BE AROUND 5 DEGREES ABOVE
NORMAL WITH LOWS 5 TO 10 DEGREES ABOVE.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 310 AM THURSDAY...A PROGRESSIVE PATTERN SETS UP FOR THE MEDIUM
RANGE. UPPER RIDGE AXIS CROSSES THE AREA SUNDAY...WITH WEAK SHORT
WAVE ENERGY MOVING THROUGH MONDAY. FLOW REMAINS ZONAL OVER THE AREA
TUESDAY AS A SHORT WAVE PASSES BY TO OUR NORTH...WITH YET ANOTHER
RIDGE AXIS MOVING THROUGH ON WEDNESDAY. AT THE SURFACE...HIGH
PRESSURE OVER THE AREA SUNDAY SLIDES EAST MONDAY WITH SOUTH TO
SOUTHWESTERLY FLOW DEVELOPING. THE GFS SHOWS SOME SHOWERS DEVELOPING
ACROSS THE MOUNTAINS MONDAY...BUT KEPT THE FORECAST DRY IN LINE WITH
THE ECMWF AND CANADIAN. THE TUESDAY SHORT WAVE MOVES A SURFACE LOW
ACROSS THE MID-ATLANTIC WHICH DRAGS A COLD FRONT SOUTH TOWARD OUR
AREA. THE GFS MOVES THE FRONT INTO OUR AREA FASTER THAN THE ECMWF
AND CANADIAN. THE ECMWF DOES MOVE THE FRONT INTO THE AREA WEDNESDAY
WHILE THE GFS STALLS THE FRONT ACROSS THE CAROLINAS. FOLLOWING A
GUIDANCE BLEND BRINGS CHANCE POP INTO THE MOUNTAINS AND I-40
CORRIDOR TUESDAY...THEN ACROSS THE ENTIRE CWFA WEDNESDAY.
HIGHS RISE THROUGH THE PERIOD...REACHING THE MID 80S OUTSIDE OF THE
MTNS TUESDAY...AND AROUND 80 IN THE MOUNTAIN VALLEYS. HIGHS FALL A
FEW DEGREES ON WEDNESDAY. LOWS FOLLOW A SIMILAR TREND...RISING INTO
THE LOW 60S OUTSIDE OF THE MOUNTAINS AND MID 50S MOUNTAIN VALLEYS.
&&
.AVIATION /07Z THURSDAY THROUGH MONDAY/...
AT KCLT/KHKY...ATLANTIC MOISTURE FLOWING OVER SHALLOW WEDGE OF HIGH
PRESSURE IS ALREADY PRODUCING MVFR CIGS OVER THE NC PIEDMONT. THE
NAM FAMILY OF MODELS IS HANDLING THE STRATUS MOST ACCURATELY
ATTM...SO USED A CONSENSUS OF NAM AND HRRR FOR CLOUD BASES THRU
THE MRNG. THEY GENERALLY SHOW AT LEAST BKN MVFR PERSISTING UNTIL A
COUPLE HRS AFTER DAYBREAK...AND HINT AT PATCHY IFR AS WELL. WITH
CIGS ALREADY DEVELOPING AND WITH DRY SFC DEWPOINTS...NOT SURE IF
SATURATION WILL OCCUR LOW ENOUGH TO BRING CIGS TO IFR...SO THAT IS
LEFT IN TEMPO. FOLLOWING THE DISSOLUTION OF THE STRATUS...MAINLY
MID-HIGH CLOUDS WILL BE SEEN TODAY. APPROACH OF COLD FRONT FROM THE
WEST TONIGHT WILL REINTRODUCE A LOW VFR DECK THIS EVENING. WINDS
WILL REMAIN SOUTHERLY...AND A FEW LOW-END GUSTS ARE POSSIBLE
THIS AFTN.
ELSEWHERE...MOST GUIDANCE KEEPS THE IFR CIGS EAST OF THE REMAINING
TAF SITES...BUT MVFR SHOULD EXPAND OVER KGSP/KGMU/KAVL BEFORE
DAWN. CAN/T TOTALLY RULE OUT IFR...SO I WILL KEEP AN EYE ON NEARBY
TRENDS AND AMD IF NECESSARY. THIS WILL BE THE MAIN IMPACTFUL WEATHER
THRU THE DAY TODAY...WITH SCT-BKN CIRRUS AND MODEST SOUTHERLY
WINDS. A SMALL CHC OF TSRA EXISTS OVER THE SW NC MTNS...BUT CHC
IS TOO LOW TO MENTION AT KAVL. COLD FRONT WILL BRING BETTER SHRA
CHANCES THIS EVENING FROM WEST TO EAST...HENCE PROB30 AT KAVL. MVFR
CIGS WILL PRECEDE THE FRONT...BUT ONLY KAND IS EXPECTED TO SEE
SUCH PRIOR TO 06Z.
OUTLOOK...RAIN CHANCES INCREASE EARLY FRI AHEAD OF ANOTHER COLD
FRONT APPROACHING THE AREA. HIGH PRESSURE AND MOSTLY VFR CONDITIONS
WILL RETURN SATURDAY FOLLOWING THE DEPARTURE OF THE FRONT.
CONFIDENCE TABLE...
07-13Z 13-19Z 19-01Z 01-06Z
KCLT HIGH 96% HIGH 92% HIGH 100% HIGH 100%
KGSP HIGH 90% HIGH 92% HIGH 100% HIGH 100%
KAVL HIGH 85% HIGH 92% HIGH 100% MED 78%
KHKY HIGH 91% HIGH 89% HIGH 100% HIGH 100%
KGMU HIGH 98% HIGH 98% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 91% HIGH 100% HIGH 88%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULE TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLET HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK:
WWW.WEATHER.GOV/GSP/AVIATION
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...RWH
NEAR TERM...WIMBERLEY
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...WIMBERLEY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
159 AM EDT THU APR 21 2016
.SYNOPSIS...
PRECIPITATION CHANCES INCREASE THROUGH FRIDAY AS A SECOND COLD
FRONT MOVES IN FROM THE WEST...ALTHOUGH RAINFALL AMOUNTS ARE
EXPECTED TO REMAIN LIGHT. FOLLOWING THE FRONTAL PASSAGE ON
SATURDAY...DRY AND WARM HIGH PRESSURE WILL BUILD IN ACROSS THE
FORECAST AREA FOR SUNDAY. THE HIGH WILL SLIDE OFFSHORE EARLY
MONDAY IN ADVANCE OF ANOTHER WEAK FRONT AND CHANCE FOR LIGHT
PRECIPITATION FROM MONDAY EVENING THROUGH WEDNESDAY.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 145 AM...STRATUS ARE BEGINNING TO DEVELOP EAST OF HWY 321
AS ATLANTIC MOISTURE FLOWS OVER WEAKENING WEDGE. BEST GUIDANCE
CONSENSUS SUGGESTS THESE CLOUDS WILL HAVE TROUBLE EXPANDING TO THE
BLUE RIDGE...BUT MAY CONTINUE TO EXPAND OVER ERN UPSTATE SC. SOME
LIGHT FOG MAY DEVELOP AS WELL...BUT DEWPT DEPRESSIONS ARE GENERALLY
TOO LARGE TO EXPECT SIGNIFICANT VSBY RESTRICTIONS. UPDATED TEMPS
ARE SOMEWHAT WARMER ON ACCOUNT OF THE STRATUS.
MODELS WILL ERODE WEDGE THROUGH THE EVENING/OVERNIGHT
HOURS...ALLOWING SFC FLOW OVER THE PIEDMONT TO GRADUALLY VEER
AS WEAK MOISTURE ADVECTION COMMENCES. HOWEVER IT IS NOT UNTIL
MIDDAY THAT UPGLIDE/UPSLOPE WILL BE CAPABLE OF PRECIP...THOUGH
LITTLE FURTHER ENHANCEMENT OCCURS DURING THE DAY. GUIDANCE FAVORS
SHRA POTENTIAL LATE IN THE PERIOD ACROSS THE WESTERN HALF OF THE
FCST AREA...WITH PROFILES POSSIBLY SUPPORTING WEAK TSRA. POPS ARE
REINTRODUCED LATE WITH CHANCES ALONG THE HIGH TERRAIN WHILE SLIGHT
CHANCES PREVAIL OVER THE FTHILLS AND WESTERN PIEDMONTS OF NC/SC AS
WELL AS NORTHEAST GA. EXPECTING OVERNIGHT LOWS TO BE GENERALLY 4-6
DEGREES ABOVE NORMAL WHILE HIGHS ON THURSDAY TOP OUT NEAR NORMAL.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY/...
AS OF 210 PM WEDNESDAY...THE SHORT TERM WILL SEE THE BREAKING DOWN
OF THE OMEGA-BLOCK PATTERN THAT HAS BEEN IMPACTING THE WEATHER ACROSS
MUCH OF THE EAST FOR THE PAST WEEK OR SO...AS A PROGRESSIVE/COMPACT
UPPER LOW MOVES ACROSS THE OHIO VALLEY AND VICINITY THU NIGHT/
FRIDAY. WHILE THIS WILL BE THE GENERAL TREND...THE LATEST MODEL
GUIDANCE IS NOT IN THE GREATEST AGREEMENT REGARDING THE
TRACK/TIMING/INTENSITY OF THIS FEATURE AS IT PROGRESSES ACROSS THE
EASTERN CONUS. THERE ARE ESSENTIALLY TWO CAMPS...THE FARTHER
SOUTH/SLOWER/STRONGER SOLUTION (CANADIAN GEM AND THE NAM) AND THE
FARTHER NORTH/FASTER/WEAKER SOLUTION (THE GFS AND ECMWF). AS
SUCH...THE FORMER CAMP DEPICTS STRONGER FORCING/QPF ACROSS OUR AREA
DURING THE DAY FRIDAY (AS THIS BETTER FORCING INTERACTS WITH A MORE
UNSTABLE AIR MASS IN THIS SLOWER SCENARIO)... WHILE THE LATTER CAMP
DEPICTS CONSIDERABLY LIGHTER PRECIP ACROSS THE AREA THU NIGHT AND
EARLY FRIDAY. EVEN IF THE NAM/CANADIAN CAMP PROVES VERIFYING CLOSER
TO REALITY...THERE IS NOT EXACTLY IDEAL OVERLAP BETWEEN THE
STRONGEST FORCING...BUOYANCY...AND WIND SHEAR...WHICH MAY COMBINE TO
LIMIT THE OVERALL COVERAGE AND INTENSITY OF CONVECTION.
NEVERTHELESS...FROM A POP STANDPOINT IT WOULD APPEAR THAT LIKELIES
ARE WARRANTED ACROSS THE FORECAST AREA FRIDAY. THERE WILL BE A
CHANCE FOR A SEVERE STORM OR TWO ACROSS THE PIEDMONT FRI
AFTERNOON...ESP IF THE SLOWER MODEL SOLUTIONS END UP WORKING
OUT.
CONDITIONS WILL GRADUALLY CLEAR LATE FRI INTO SATURDAY...SETTING THE
STAGE FOR ANOTHER MOSTLY SUNNY SATURDAY (EXCEPT PERHAPS WITH SOME NW
FLOW CLOUDS POSSIBLE ACROSS THE FAR WESTERN NC MTNS) WITH TEMPS
AVERAGING A CATEGORY OR SO ABOVE CLIMO.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 310 AM WEDNESDAY...UPPER RIDGING BUILDS INTO THE AREA SUNDAY
WITH WEAK SHORT WAVE ENERGY CROSSING THE AREA MONDAY AND TUESDAY.
DURING THIS TIME...A STRONG UPPER LOW DEVELOPS OVER EASTERN QUEBEC
WHICH RETROGRADES BY THE END OF THE PERIOD. AT THE SURFACE...HIGH
PRESSURE CROSSES THE AREA SUNDAY AND MOVES INTO THE ATLANTIC MONDAY.
A COLD FRONT DROPS SOUTH TOWARD THE AREA MONDAY. ON TUESDAY...THE
GFS BRINGS THE FRONT SOUTH INTO THE AREA WHILE THE ECMWF KEEPS THE
FRONT NORTH OF THE AREA. BOTH MODELS DEVELOP A LOW PRESSURE CENTER
ALONG THE FRONT AS IT MOVES SOUTH. THE GFS BRINGS MORE IN THE WAY OF
PRECIP TO OUR AREA SINCE IT IS FARTHER SOUTH. HOWEVER...THE ECMWF
DOES SHOW PRECIP MOVING INTO AT LEAST THE NORTHERN CWFA. USING A
GUIDANCE BLEND KEEPS THE FORECAST DRY THROUGH MONDAY...WITH CHANCE
POP DEVELOPING FOR MAINLY THE MOUNTAINS ON TUESDAY.
WITH THE FRONT REMAINING NORTH OF THE AREA UNTIL VERY LATE IN THE
PERIOD...HIGHS WILL RISE BACK INTO THE 80S FOR MOST OF THE AREA BY
TUESDAY...WHILE LOWS RISE INTO THE 60S FOR MOST OF THE AREA.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AT KCLT/KHKY...ATLANTIC MOISTURE FLOWING OVER SHALLOW WEDGE OF HIGH
PRESSURE IS ALREADY PRODUCING MVFR CIGS OVER THE NC PIEDMONT. THE
NAM FAMILY OF MODELS IS HANDLING THE STRATUS MOST ACCURATELY
ATTM...SO USED A CONSENSUS OF NAM AND HRRR FOR CLOUD BASES THRU
THE MRNG. THEY GENERALLY SHOW AT LEAST BKN MVFR PERSISTING UNTIL A
COUPLE HRS AFTER DAYBREAK...AND HINT AT PATCHY IFR AS WELL. WITH
CIGS ALREADY DEVELOPING AND WITH DRY SFC DEWPOINTS...NOT SURE IF
SATURATION WILL OCCUR LOW ENOUGH TO BRING CIGS TO IFR...SO THAT IS
LEFT IN TEMPO. FOLLOWING THE DISSOLUTION OF THE STRATUS...MAINLY
MID-HIGH CLOUDS WILL BE SEEN TODAY. APPROACH OF COLD FRONT FROM THE
WEST TONIGHT WILL REINTRODUCE A LOW VFR DECK THIS EVENING. WINDS
WILL REMAIN SOUTHERLY...AND A FEW LOW-END GUSTS ARE POSSIBLE
THIS AFTN.
ELSEWHERE...MOST GUIDANCE KEEPS THE IFR CIGS EAST OF THE REMAINING
TAF SITES...BUT MVFR SHOULD EXPAND OVER KGSP/KGMU/KAVL BEFORE
DAWN. CAN/T TOTALLY RULE OUT IFR...SO I WILL KEEP AN EYE ON NEARBY
TRENDS AND AMD IF NECESSARY. THIS WILL BE THE MAIN IMPACTFUL WEATHER
THRU THE DAY TODAY...WITH SCT-BKN CIRRUS AND MODEST SOUTHERLY
WINDS. A SMALL CHC OF TSRA EXISTS OVER THE SW NC MTNS...BUT CHC
IS TOO LOW TO MENTION AT KAVL. COLD FRONT WILL BRING BETTER SHRA
CHANCES THIS EVENING FROM WEST TO EAST...HENCE PROB30 AT KAVL. MVFR
CIGS WILL PRECEDE THE FRONT...BUT ONLY KAND IS EXPECTED TO SEE
SUCH PRIOR TO 06Z.
OUTLOOK...RAIN CHANCES INCREASE EARLY FRI AHEAD OF ANOTHER COLD
FRONT APPROACHING THE AREA. HIGH PRESSURE AND MOSTLY VFR CONDITIONS
WILL RETURN SATURDAY FOLLOWING THE DEPARTURE OF THE FRONT.
CONFIDENCE TABLE...
06-12Z 12-18Z 18-24Z 00-06Z
KCLT HIGH 91% HIGH 95% HIGH 100% HIGH 100%
KGSP HIGH 91% HIGH 92% HIGH 100% HIGH 100%
KAVL HIGH 88% HIGH 88% HIGH 100% HIGH 83%
KHKY HIGH 92% HIGH 89% HIGH 100% HIGH 100%
KGMU HIGH 99% HIGH 94% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 92% HIGH 100% HIGH 91%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULE TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLET HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK:
WWW.WEATHER.GOV/GSP/AVIATION
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JMP
NEAR TERM...CDG/WIMBERLEY
SHORT TERM...JDL
LONG TERM...PM
AVIATION...WIMBERLEY
AREA FORECAST DISCUSSION...UPDATED
NWS MORRISTOWN TN
1042 AM EDT THU APR 21 2016
.DISCUSSION...
OBSERVED TEMPERATURES HAVE BEEN RUNNING A LITTLE HIGHER THAN
FORECAST IN A FEW SPOTS...AND THE LATEST MOS GUIDANCE SUPPORTS
RAISING TEMPERATURES A LITTLE FOR TODAY...MAINLY AROUND KNOXVILLE.
THE WARMER TEMPS WILL ALSO MEAN LOWER RH VALUES...INTO THE 25-30
PERCENT RANGE FROM KNOXVILLE TO SW VA. WEATHER CONDITIONS WILL NOT
BE HELPFUL FOR ONGOING WILDFIRES THIS AFTERNOON...WITH S-SW WINDS
OF 10-15 MPH...AND GUSTS TO 30 MPH IN THE MOUNTAINS.
FORTUNATELY...RAIN WILL BE MOVING INTO THE PLATEAU LATE THIS
AFTERNOON...BETWEEN 5 AND 8 PM ACCORDING TO THE HRRR AND RAP. THE
UPDATE WILL ADJUST POPS TODAY AND TONIGHT TO REFLECT THIS. AMOUNTS
OF A TENTH TO A QUARTER INCH ARE EXPECTED THROUGH TONIGHT...WITH
MORE POSSIBLE WITH A SECOND ROUND OF SHOWERS FRIDAY MORNING.
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
DGS
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
337 PM CDT THU APR 21 2016
.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...LATEST SATELLITE IMAGERY
SHOWS AN OUTFLOW BOUNDARY EXTENDING FROM NORTH OF LAREDO TO NEAR
KINGSVILLE THIS AFTERNOON. THE COMBINATION OF A SOUTHWARD MOVING
BOUNDARY ACROSS SOUTH TEXAS...AN INLAND MOVING SEA BREEZE EXTENDING
FROM BROWNSVILLE TO NEAR CORPUS CHRISTI AND DAYTIME HEATING WILL
SUPPORT THE DEVELOPMENT OF ISOLATED TO SCATTERED CONVECTION FOR THE
REST OF THE AFTERNOON INTO THIS EVENING. BROWNSVILLE RADAR CURRENTLY
SHOWS ISOLATED ACTIVITY ACROSS KENEDY AND WILLACY COUNTIES. THE
STORM PREDICTION CENTER /SPC/ HAS ALL OF DEEP SOUTH TEXAS UNDER A
MARGINAL RISK OF SEVERE WEATHER THROUGH TONIGHT. THE MAIN THREATS
FROM ANY OF THE STORMS THAT DEVELOP THIS AFTERNOON INTO THIS EVENING
WILL BE SMALL HAIL...GUSTY WINDS AND LOCALLY HEAVY RAINFALL.
THE 21Z HRRR INDICATES CONVECTION WILL CONTINUE TO DEVELOP ACROSS
THE COASTAL COUNTIES THROUGH LATE AFTERNOON WITH ADDITIONAL
DEVELOPMENT ACROSS ZAPATA AND STARR THIS EVENING. THE 12Z NAM KEEPS
MOST OF THE CONVECTION OVER THE GULF WATERS...THE 12Z GFS SHOWS A
LITTLE CONVECTION OVER THE VALLEY...AND THE 12Z ECMWF SHOWS MORE
ROBUST CONVECTION ACROSS THE AREA. BASED ON CURRENT TRENDS WILL GO
ABOVE MET/MAV GUIDANCE FOR POPS THROUGH THE REST OF THIS AFTERNOON
AND EVENING.
THE APPROACH AND PASSAGE OF A 500 MB DISTURBANCE ALONG WITH A WEAK
COLD FRONT SAGGING SOUTH WILL GENERATE ISOLATED SCATTERED CONVECTION
OVER PORTIONS OF DEEP SOUTH TEXAS TONIGHT. THE COLD FRONT STALLS
OVER DEEP SOUTH TEXAS FRIDAY AND FRIDAY NIGHT. POOLING MOISTURE IN
ADVANCE OF THIS SURFACE FEATURE WILL COMBINE WITH DAYTIME
HEATING...AND ENHANCED SEA BREEZE EFFECT...AND ANOTHER WEAK 500 MB
DISTURBANCE TO PRODUCE MAINLY SCATTERED CONVECTION ON FRIDAY. LOW
TEMPERATURES TONIGHT WILL GENERALLY BE IN THE LOWER 70S. HIGH
TEMPERATURES FRIDAY WILL RANGE FROM THE LOWER 80S NEAR THE COAST TO
THE UPPER ACROSS THE UPPER VALLEY. LOW TEMPERATURES WILL BE SLIGHTLY
COOLER FRIDAY NIGHT WITH TEMPERATURES FALLING INTO THE MID 60S TO
AROUND 70.
&&
.MARINE...NOW THROUGH FRIDAY NIGHT...BUOY 42020 REPORTED NORTH WINDS
AROUND 2 KNOTS GUSTING TO AROUND 4 KNOTS WITH SEAS SLIGHTLY UNDER
3.3 FEET WITH A PERIOD OF 7 SECONDS AT 15 CDT/19 UTC. A WEAK
GRADIENT ALONG THE LOWER TEXAS COAST WILL MAINTAIN LIGHT TO MODERATE
WINDS AND LOW TO MODERATE SEAS THROUGH THE PERIOD. NO SMALL CRAFT
EXERCISE CAUTION OR SMALL CRAFT ADVISORY ANTICIPATED.
&&
.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL 73 80 70 79 / 20 30 10 30
BROWNSVILLE 73 83 70 82 / 20 30 20 30
HARLINGEN 72 84 69 83 / 20 30 10 30
MCALLEN 73 87 70 85 / 30 30 10 40
RIO GRANDE CITY 72 88 70 86 / 30 30 20 50
SOUTH PADRE ISLAND 73 77 71 77 / 20 20 20 20
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
63/61/BILLINGS
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
1253 PM CDT THU APR 21 2016
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...THE COMBINATION OF A SOUTHWARD MOVING BOUNDARY
ACROSS CENTRAL TEXAS...THE SEA BREEZE AND DAYTIME HEATING EXPECTED
TO GENERATE ISOLATED TO SCATTERED CONVECTION THIS AFTERNOON.
THE LATEST HRRR MODEL INDICATES SOME ACTIVITY DEVELOPING ACROSS
THE RIO GRANDE VALLEY BETWEEN 19 TO 00Z. WILL MENTION VCTS AT
ALL THREE TAF SITES THIS AFTERNOON. CONVECTION WILL WEAKEN LATER
THIS EVENING WITH THE LOSS OF DAYTIME HEATING. MVFR WITH IFR
CONDITIONS POSSIBLE LATER TONIGHT INTO FRIDAY MORNING DUE TO
POOLING LOW LEVEL MOISTURE AND LIGHT WINDS.
&&
.PREV DISCUSSION... /ISSUED 948 AM CDT THU APR 21 2016/
DISCUSSION...THE COMBINATION OF A SOUTHWARD MOVING BOUNDARY
ACROSS CENTRAL TEXAS...THE SEA BREEZE AND DAYTIME HEATING WILL
SUPPORT THE DEVELOP OF ISOLATED TO SCATTERED CONVECTION FOR THE
REST OF TODAY. THE STORM PREDICTION CENTER /SPC/ HAS PLACE ALL OF
DEEP SOUTH TEXAS UNDER A MARGINAL RISK OF SEVERE WEATHER FOR TODAY
AND TONIGHT. THE MAIN THREATS FROM ANY STORMS THAT DEVELOP THIS
AFTERNOON INTO THIS EVENING WILL BE SMALL HAIL...GUSTY WINDS AND
LOCALLY HEAVY RAINFALL. MADE A QUICK UPDATE TO INCREASE POPS AND
TO MENTION SMALL HAIL...GUSTY WINDS AND HEAVY RAINFALL TO THE
WEATHER GRIDS. THE REST OF THE FORECAST LOOKS GOOD AND NO
ADDITIONAL CHANGES ARE NEEDED AT THIS TIME.
PREV DISCUSSION... /ISSUED 554 AM CDT THU APR 21 2016/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...LIGHT FOG AND MVFR CEILINGS HAVE DEVELOPED DURING THE
OVERNIGHT HOURS. FULL VFR WILL DEVELOP AND PREVAIL AFTER SUNRISE
THIS MORNING WITH MODERATE SURFACE WINDS. MVFR IS ANTICIPATED
AGAIN TONIGHT WITH LOWERED CEILINGS AND MUCH LIGHTER WINDS. ONE
ASPECT OF THE TAF FORECAST THAT MAY NEED TO BE ADJUSTED BY A
FOLLOWING SHIFT IS THE INCLUSION OF THE MENTION OF CONVECTION FOR
MFE...AS ANOTHER ROUND OF SHOWERS/THUNDERSTORMS WILL LIKELY FORM
OVER THE MOUNTAINS OF NEIGHBORING MEXICO BEFORE MOVING OVER
PORTIONS OF DEEP SOUTH TEXAS AND THE RIO GRANDE VALLEY.
PREV DISCUSSION... /ISSUED 420 AM CDT THU APR 21 2016/
SHORT TERM /NOW THROUGH FRIDAY/...AN UNSETTLED WEATHER PATTERN
IS ANTICIPATED TO CONTINUE THROUGHOUT THE SHORT TERM PORTION OF
THE FORECAST. ISOLATED SHOWERS AND THUNDERSTORMS WILL DEVELOP
TODAY AS A RESULT OF A WEAK 500 MB DISTURBANCE RIDING WITHIN A
NEARLY WEST TO EAST MID-LEVEL FLOW OVERHEAD. INHERITED HIGH
TEMPERATURES APPEARED TOO COOL WHEN COMPARED TO YESTERDAY/S
OBSERVED HIGHS AND WERE RAISED ABOUT THREE DEGREES OVER THE ENTIRE
BRO CWFA. TONIGHT...THE APPROACH AND PASSAGE OF A MORE ROBUST 500
MB DISTURBANCE...AND THE SLOW SOUTHERLY MOVEMENT OF A WEAK COLD
FRONT THROUGH THE CRP CWFA... WILL GENERATE SCATTERED CONVECTION
OVER THE WESTERN TWO THIRDS OF THE BRO CWFA AND ISOLATED
PRECIPITATION WITHIN THE EASTERN THIRD. IN FACT...THE STORM
PREDICTION CENTER PLACES A MARGINAL RISK OF SEVERE WEATHER WITHIN
ZAPATA...JIM HOGG...BROOKS...AND KENEDY COUNTIES FOR TODAY AND
TONIGHT. HAVE NOT INCLUDED ANY MENTION OF STRONG WINDS OR LARGE
HAIL IN THE FORECAST...BUT WILL ADVISE SUCCESSIVE SHIFTS TO
MONITOR THIS TREND AND PLACE A MENTION OF ROUGH WEATHER IN THE
FORTHCOMING HAZARDOUS WEATHER OUTLOOK. MINIMUM TEMPERATURES FOR
TONIGHT WERE INCREASED A COUPLE OF NOTCHES ABOVE WHAT WAS
INHERITED. FOR FRIDAY...THE AFOREMENTIONED COLD FRONT STALLS
ROUGHLY ALONG THE BRO AND CRP CWFA BOUNDARY. POOLING MOISTURE IN
ADVANCE OF THIS SURFACE FEATURE WILL COMBINE WITH DAYTIME
HEATING...AND ENHANCED SEA BREEZE EFFECT...AND ANOTHER WEAK 500 MB
DISTURBANCE TO PRODUCE MAINLY SCATTERED CONVECTION.
LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY NIGHT/...A RIDGE AXIS
WILL EXTEND NORTH FROM NORTHEAST MEXICO ACROSS THE HIGH PLAINS AND
INTO CANADA. HIGH PRESSURE WILL BE IN CONTROL FOR THE MOST PART...
WITH A STATIONARY FRONT LYING ACROSS SOUTH CENTRAL TEXAS. A MID
LEVEL LOW WILL BE ENTERING THE PACIFIC NORTHWEST WHILE ANOTHER
UPPER LOW OVER THE SOUTHERN BAHA PENINSULA EJECTS EAST AS A TROUGH
OVER THE AREA. AMPLE MOISTURE AND SUFFICIENT INSTABILITY WILL KEEP
THE THREAT OF SHOWERS AND TSTMS GOING THROUGH THE WEEKEND. THE ECMWF
IS MORE AGGRESSIVE WITH POPS FRIDAY NIGHT THROUGH SUNDAY. A MODEL
CONSENSUS STRUCK A MIDDLE GROUND. OTHER MODEL DIFFERENCES WERE MINOR.
HIGH PRESSURE OVER THE PLAINS WILL ADVANCE SOUTH WITH A WEAK COLD
FRONT MOVING INTO SOUTH TEXAS. THE FRONT WILL HAVE MINOR IMPACT HERE
THOUGH...SHIFTING LOCAL WINDS TO EAST ON FRI WITH LIMITED RAINFALL
AS ADVERTISED BY THE GFS.
HIGH PRESSURE WILL SHIFT EAST AND WINDS WILL VEER TO SOUTHEAST AGAIN
BY SATURDAY. THE ACCUMULATION OF RETURN MOISTURE AND THE REMAINS OF
THE OLD FRONTAL BOUNDARY JUST TO THE SOUTH WILL PROVIDE A FOCUS FOR
SHOWERS TO DEVELOP ACROSS THE PLAINS OF NORTHEAST MEXICO AS WELL AS
ALONG THE RIO GRANDE. TROUGHING...OR A DEEP POCKET OF LOWER MID
LEVEL HEIGHTS OVER NORTHWEST MEXICO...WILL ALSO KEEP A SOUTHWEST
FLOW GOING ALOFT...ADDING TO INSTABILITY OVER THE MEXICAN MOUNTAINS
AND PERHAPS FUELING SOME CONVECTION THERE FRIDAY NIGHT. THE TROUGH
WILL ADVANCE EAST SATURDAY...BECOMING MORE PROXIMATE TO THE RGV AND
MAINTAINING CONVECTIVE CHANCES FOR THE RGV THROUGH SATURDAY NIGHT.
MOISTURE WILL POOL OVER THE CWA...UNDER THE TROUGH MOVING OVERHEAD.
THE BEST CHANCE OF SHOWERS AND THUNDERSTORMS MOVING EAST FROM MEXICO
TOWARD THE MID AND UPPER VALLEY WILL BE SATURDAY NIGHT.
ONCE THE TROUGH SHIFTS EAST OF THE REGION SUNDAY NIGHT...DRIER AIR
WILL FILTER IN WITH A WARMING AND CLEARING TREND MONDAY THROUGH
WEDNESDAY. AS THE TROUGH EXITS STAGE RIGHT SUNDAY...RAIN CHANCES
WILL DIMINISH BUT NOT QUITE END. THUS A CHANGE WILL BEGIN SUNDAY
NIGHT AND AFTER. A WEAK RIDGE WILL BUILD IN FROM THE WEST...AND
WITHOUT ANOTHER STRONG TROUGH UPSTREAM TO FOLLOW UP...THE FIRST HALF
OF NEXT WEEK LOOKS FAIRLY DRY FOR THE TIME BEING.
SHOULD SEE MOSTLY CLOUDY OR CLOUDY SKIES WEDNESDAY NIGHT THROUGH
SUNDAY NIGHT. TEMPS WILL BE CLOSE TO NORMAL THOUGH A LITTLE WARMER
THAN NORMAL AT NIGHT WITH THE EXTRA CLOUD COVER. WINDS WILL BE
MAINLY OUT OF THE SOFOR
THE REST OF TODAY. THE STORM PREDICTION CENTER /SPC/ HAS PLACE ALL
OF DEEP SOUTH TEXAS UNDER A MARGINAL RISK OF SEVERE WEATHER FOR
TODAY AND TONIGHT. THE MAIN THREATS FROM ANY STORMS THAT DEVELOP
THIS AFTERNOON INTO THIS EVENING WILL BE SMALL HAIL...GUSTY WINDS
AND LOCALLY HEAVY RAINFALL. MADE A QUICK UPDATE TO INCREASE POPS
AND TO MENTION SMALL HAIL...GUSTY WINDS AND HEAVY RAINFALL TO THE
WEATHER GRIDS. THE REST OF THE FORECAST LOOKS GOOD AND NO
ADDITIONAL CHANGES ARE NEEDED AT THIS TIME.UTHEAST.
MARINE...
NOW THROUGH FRIDAY...BUOY 42020 REPORTED SOUTH-SOUTHEAST WINDS
AROUND 16 KNOTS GUSTING TO AROUND 18 KNOTS WITH SEAS SLIGHTLY
UNDER 3.5 FEET WITH A PERIOD OF 7 SECONDS AT 03 CDT/08 UTC. HIGH
PRESSURE WILL PREVAIL OVER THE WESTERN GULF OF MEXICO UNTIL A WEAK
COLD FRONT APPROACHES FROM THE NORTH AND STALLS OVER THE MIDDLE
TEXAS COAST. LIGHT TO MODERATE WINDS AND LOW TO MODERATE SEAS WILL
PREVAIL AS A RESULT OF THIS WEATHER PATTERN...WITH NO SMALL CRAFT
EXERCISE CAUTION OR SMALL CRAFT ADVISORY ANTICIPATED.
FRIDAY NIGHT THROUGH MONDAY NIGHT...HIGH PRESSURE WILL SPREAD OVER
THE NORTHWEST GULF WITH A WEAK STATIONARY FRONT STRETCHING ALONG THE
UPPER TEXAS COAST AND ACROSS SOUTH CENTRAL TEXAS FRIDAY NIGHT. LIGHT
TO MODERATE EAST WINDS WILL PREVAIL LOCALLY THROUGH SATURDAY BEFORE
A LIGHT TO MODERATE SOUTHEAST WIND REDEVELOPS AND PERSISTS THROUGH
SUNDAY. WIND DIRECTION WILL VEER TO SOUTH SOUTHEAST OR SOUTH LATE
SUNDAY DUE TO A TRANSITING NORTHERN PLAINS LOW. WINDS AND SEAS WILL
INCREASE TO MODERATE.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
63
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
1249 AM CDT THU APR 21 2016
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...A CLUSTER OF DISSIPATING THUNDERSTORMS HAS SLOWLY BEEN
MOVING FROM THE WESTERN PORTION OF DEEP SOUTH TEXAS AND THE RIO
GRANDE VALLEY INTO THE CENTRAL PORTION. LIGHT RAIN HAS DEVELOPED
WITHIN THE VICINITY OF MFE...AND SHOULD PERSIST THROUGH THE NEXT
FEW HOURS. MEANWHILE...IT IS ANTICIPATED THAT BRO AND HRL WILL
REMAIN DRY. MVFR CEILINGS ARE ALSO ANTICIPATED FOR THE REMAINDER
OF THE OVERNIGHT HOURS AND THROUGH THURSDAY MORNING. TOMORROW
AFTERNOON...VFR WILL RETURN WITH MODERATE SURFACE WINDS...WITH
VFR/MVFR ANTICIPATED TOMORROW NIGHT.
&&
.PREV DISCUSSION... /ISSUED 1001 PM CDT WED APR 20 2016/
DISCUSSION...ONGOING SEVERE THUNDERSTORMS AND HEAVY RAINFALL
CONTINUES OVER ZAPATA COUNTY LATE THIS EVENING. THE CONVECTION IS
EXPECTED TO WEAKEN OVER THE COUPLE OF HOURS AS THE ATMOSPHERE
BECOMES MORE STABLE. MADE A QUICK UPDATE TO INCREASE POPS ACROSS
ZAPATA COUNTY AND LOWER POPS ACROSS THE EASTERN PORTIONS OF DEEP
SOUTH TEXAS. THE REST OF THE FORECAST LOOKS GOOD AND NO OTHER
CHANGES NEEDED AT THIS TIME.
PREV DISCUSSION... /ISSUED 708 PM CDT WED APR 20 2016/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...SATELLITE AND RADAR IMAGES INDICATE SOME ONGOING
CONVECTION WITH MID TO HIGH LEVEL CLOUDS OVER THE MOUNTAINS OF
NORTHEAST MEXICO THIS EVENING. WITH SURFACE INSTABILITY
RELATIVELY HIGH ACROSS THE PORTIONS OF DEEP SOUTH TEXAS AND WEST
TO EAST FLOW ALOFT...THERE IS A SMALL CHANCE THAT SOME STORMS
COULD MOVE INTO THE WESTERN PORTIONS OF THE CWA LATER THIS
EVENING. AN ISOLATED STORM COULD IMPACT MFE THROUGH LATE THIS
EVENING...SO WILL CONTINUE TO MENTION VCTS FOR MFE THROUGH 04Z.
OTHERWISE...MID TO HIGH LEVEL CLOUD COVER WILL INCREASE ACROSS THE
RIO GRANDE VALLEY THROUGH THIS EVENING DUE TO DEBRIS CLOUDS FROM
THE EARLIER STORMS OVER NORTHERN MEXICO. LOW CLOUDS EXPECTED TO
DEVELOP LATER THIS EVENING RESULTING IN MVFR TO POSSIBLE IFR
CEILINGS OVERNIGHT. VFR CONDITIONS WILL RETURN LATE THURSDAY
MORNING INTO EARLY AFTERNOON.
PREV DISCUSSION... /ISSUED 311 PM CDT WED APR 20 2016/
SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...SATELLITE AND RADAR
IMAGES INDICATE CONVECTION CONTINUING TO DEVELOP ACROSS NORTHEAST
MEXICO THIS AFTERNOON AND BOTH THE NAM AND HRRR CONTINUE TO
INDICATE CONVECTION DEVELOPING ACROSS EXTREME WESTERN PORTIONS OF
THE CWA LATE THIS AFTERNOON INTO THIS EVENING. WITH THE SURFACE
INSTABILITY REMAINING HIGH ACROSS THE RIO GRANDE VALLEY AND
NORTHERN RANCHLANDS...CANNOT RULE OUT THE POTENTIAL FOR ISOLATED
SEVERE THUNDERSTORMS ACROSS PORTIONS OF ZAPATA...JIM HOGG...AND
STARR COUNTIES THIS EVENING. THE GREATEST THREAT FOR SEVERE
APPEARS TO BE HAIL AND DAMAGING WINDS. HEAVY RAINFALL CAN BE
EXPECTED WITH SOME OF THE STRONGER TO SEVERE STORMS. WILL GO WITH
THE HIGHEST POPS ACROSS THE WESTERN PORTIONS OF THE CWA WITH LOWER
POPS TOWARDS THE COAST THIS EVENING.
THE FORECAST FOR THURSDAY AND THURS NIGHT IS CHALLENGING WITH THE
WEST TO NORTHWEST FLOW ALOFT BUT THE NAM AND GFS HAVE A CONVECTIVE
BOUNDARY DEVELOPING ACROSS PORTIONS OF CENTRAL TX THURSDAY AND AS
THIS FEATURE MOVES SOUTHWARD IT WILL PROVIDE A SLIGHT CHANCE OF
SHOWERS AND THUNDERSTORMS ACROSS PORTIONS OF THE CWA THURSDAY INTO
THURS NIGHT AS MOISTURE POOLS ALONG AND AHEAD OF A WEAK COLD FRONT
MOVES SOUTHWARD ACROSS SOUTH TX.
LONG TERM /FRIDAY THROUGH WEDNESDAY/...UPPER LEVEL RIDGE WILL
BEGINS TO BUILD ACROSS THE DESERT SOUTHWEST INTO S TEXAS FRIDAY
WITH A WEAK FRONT MOVING SOUTH. WEAK FRONT COMBINED WITH PERTURBATIONS
WITHIN THE FLOW WILL ENHANCE SHOWERS AND THUNDERSTORMS ACROSS THE
CWA. THE BOUNDARY WILL STALLED OVER DEEP SOUTH TEXAS WITH WINDS
REMAINING EASTERLY INTO SATURDAY. AN ABUNDANT SURGE OF MOISTURE
WILL MOVE INTO THE AREA CONTINUING THE DEVELOPMENT OF MORE SHOWERS
AND THUNDERSTORMS ACROSS THE WESTERN COUNTIES THIS WEEKEND. MODEL
GUIDANCE CONTINUE TO SHOW ABOVE 1.5 IN OF PRECIPITABLE WATER
THROUGH THE WEEKEND WHICH WILL FAVOR THE DEVELOPMENT WITH THIS
TROUGH AS IT MOVES EASTWARD. DRIER AIR MASS MOVES INTO THE AREA
MONDAY WITH LESS SIDE TROUGH DEVELOPING OVER SOUTH CENTRAL TEXAS.
THIS WILL LIMIT THE POTENTIAL FOR RAIN BUT A FEW ISOLATED SHOWERS
CAN`T BE RULED NEAR THE COAST WITH THE SEABREEZE. THE RIDGE WILL
BE IN CONTROL OF THE AREA MONDAY AND TUESDAY LIMITING THE
POTENTIAL FOR RAIN THROUGH MID WEEK. THE SOUTHERLY FLOW WILL
INCREASE TO MORE BREEZE CONDITIONS MONDAY AS THE NEXT UPPER TROUGH
STRENGTHENS OVER THE PAC NORTHWEST. MODELS ARE IN PRETTY GOOD
AGREEMENT WITH GFS BEEN SLIGHTLY MORE PROGRESSIVE WITH THE NEXT
LOW PRESSURE SYSTEM WHILE THE ECMWF IS A BIT SLOWER. EVEN WITH THE
SLIGHT DIFFERENCE STILL SHOW THE POTENTIAL FOR RAIN FOR THE
WEEKEND AND THE DRY AIR FILTERING IN BY EARLY NEXT WEEK. LEAN
TOWARDS A BLEND OF THE TWO MODELS FOR THIS PACKAGE.
MARINE...TONIGHT THROUGH THURSDAY NIGHT...SEAS WERE NEAR 4 FEET
WITH EAST TO SOUTHEAST WINDS NEAR 10 KNOTS AT BUOY020 EARLY THIS
AFTERNOON. LIGHT TO MODERATE SOUTHEAST WINDS WILL PREVAIL ACROSS
THE COASTAL WATERS TONIGHT INTO THURSDAY WITH LOW PRESSURE ACROSS
NORTHEAST MEXICO AND A WEAK COLD FRONT DRAPED ACROSS NORTH TEXAS.
THE BOUNDARY WILL MOVE INTO SOUTH TX THURS NIGHT AND THIS WILL
CONTINUE TO PROVIDE A WEAK PRESSURE GRADIENT ACROSS THE LOWER TX
COAST.
FRIDAY THROUGH TUESDAY...SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE
FOR THE EARLY PORTION OF THE LONG TERM PERIOD AS ABUNDANT MOISTURE
IN THE REGION WILL ALLOW FOR CONVECTION TO CONTINUE. EXPECT A
MODERATE SOUTHEAST FLOW ACROSS THE GULF WITH SEAS BETWEEN 2 TO 4
FEET THROUGH THE WEEKEND. RIDGE BEGINS TO BUILD LOWERING SEAS EVEN
LESS THAN 2 FEET SAT AND SUN. AN INFLUX OF MOISTURE WILL SURGE
NORTH SAT NIGHT INTO SUN INCREASING THE CHANCE OF SHOWERS ONCE
AGAIN. SEAS WILL BEGIN TO INCREASE INTO MONDAY AS A STRONG SURFACE
LOW STRENGTHENS OVER THE CENTRAL PLAINS. SEAS WILL BEGIN TO BUILD
TO 3 TO 6 FEET WITH SCEC POSSIBLE.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
138 PM EDT THU APR 21 2016
.SYNOPSIS...
HIGH PRESSURE ALONG THE COAST WILL CONTINUE TO MOVE EAST AND
OFFSHORE TODAY. A WARM FRONT WILL PASS NORTHEAST THROUGH THE
REGION TONIGHT AHEAD OF AN APPROACHING COLD FRONT THAT WILL
REMAIN JUST WEST OF THE MOUNTAINS THROUGH EARLY FRIDAY. THIS
FRONT SHOULD PUSH EAST ACROSS THE AREA FRIDAY AFTERNOON BRINGING
A BETTER CHANCE OF MORE WIDESPREAD SHOWERS AND A FEW THUNDERSTORMS
INTO FRIDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1145 AM EDT THURSDAY...
ANOTHER MINOR UPDATE TO ACCOUNT FOR CLEARING STRATUS DECK IN EAST
AND ALSO DEEPER MIXING THAN PREVIOUSLY THOUGHT...LIKELY RESULTING
IN SOME STRONGER WIND GUSTS THROUGH THE AFTERNOON...IN THE 16 TO
24 MPH RANGE IN THE MOUNTAINS. TONGUE OF HIGHER DEW PT AIR HAS
PUSHED INTO THE NC FOOTHILLS BUT SHOULD MIX OUT OVER NEXT COUPLE
HOURS SO MADE SOME MINOR ADJUSTMENTS FOR THAT AS WELL. OTHERWISE
NO OTHER CHANGES AT THIS TIME.
PREV DISCUSSION AS OF 958 AM EDT THURSDAY...
BROKEN STRATUS DECK FROM MOIST SOUTHEASTERLY LOW LEVEL FLOW
BEGINNING TO ERODE QUICKLY WEST OF THE BLUE RIDGE...AND SATELLITE
AS WELL AS NEAR TERM MODELS SUGGEST THAT WILL CONTINUE FAIRLY
QUICKLY EAST OF BLUE RIDGE AS WELL. MEANWHILE...CLOUD COVER ACROSS
TN...KY...WV IS MAINLY MID TO HIGH AND FAIRLY THIN AND SO DO NOT
THINK THIS WILL HAVE MUCH IMPACT ON TEMPS. THUS BUMPED UP HIGH
TEMPS A FEW DEG AND HOPE THAT IS ENOUGH...AND ALSO REDUCED CLOUD
COVER SOMEWHAT.
HRRR AND SOME OTHER HI RES MODELS SUGGEST JUST BARELY ENOUGH
INSTABILITY IN CENTRAL NC AND VA TO GENERATE AN ISOLATED LATE
AFTERNOON SHOWER...BUT MOST LIKELY THIS WILL REMAIN JUST EAST OF
OUR FORECAST AREA...SO KEPT POPS BELOW 15 PERCENT BUT DID NUDGE
UPWARD AND WILL NEED TO MONITOR THIS AREA LATER TODAY FOR ANY
DEVELOPMENT IN CASE IT IS A LITTLE FARTHER WEST THAN EXPECTED.
OTHERWISE...MOST GUIDANCE CONTINUES TO SLOW DOWN APPROACH OF ANY
PRECIP AHEAD OF THE FRONT THAT IS CURRENTLY OVER NEAR THE
MISSISSIPPI RIVER. MAY NOT BE WORTH MENTIONING CHANCE POPS EVEN
IN FAR WEST UNTIL WELL AFTER MIDNIGHT. HRRR DOES SUGGEST SOME
SHOWERS ARRIVE IN FAR SW VA AROUND MIDNIGHT...BUT OTHER GUIDANCE
SHOWS THESE DISSIPATING AS THEY MOVE IN TO SOMEWHAT DRIER AIR.
THUS CONTINUED THE TREND OF REDUCING POPS THIS EVENING TO SLIGHT
CHC OR LESS...AND MAY NEED TO DO THIS EVEN MORE ON FUTURE UPDATES.
PREV DISCUSSION AS OF 222 AM EDT THURSDAY...
MOISTURE TO GRADUALLY RETURN ACROSS THE REGION OVER THE NEXT 24 HOURS
AS THE SURFACE-85H FLOW QUICKLY VEERS FROM SE THIS MORNING TO SW WHILE
INCREASING THIS AFTERNOON/OVERNIGHT AHEAD OF THE COLD FRONT TO THE
WEST. THIS LOW LOW LEVEL SOUTH/SE FLOW THIS MORNING WILL AGAIN ADVECT
LOW CLOUDS NOW OVER NORTH CAROLINA INTO AREAS MAINLY ALONG/EAST OF THE
BLUE RIDGE BEFORE GETTING BOOTED EAST THIS AFTERNOON AS THE FLOW TURNS
MORE SW. COULD EVEN SEE A SPOTTY LIGHT SHOWER OR SPOT OR TWO OF DRIZZLE
SOUTHERN BLUE RIDGE AND POINTS EAST THIS MORNING SO INCLUDED SOME
MENTION TO INIT. LATEST GUIDANCE INDICATES THAT MOST OF THE LOW CLOUDS
SHOULD BE EAST OF THE CWA BY MID AFTERNOON ALLOWING DEEPENING WARM
ADVECTION TO RETURN UNDER MOSTLY SHEARED MID/HIGH CLOUDS WITH
CONVECTION ALONG THE COLD FRONT TO THE WEST. MOISTURE ALONG WITH
LIFT/INSTABILITY APPEARS TOO LACKING TO PRODUCE MUCH IN THE WAY OF
SHOWERS THIS AFTERNOON DESPITE TEMPS WARMING BACK INTO THE 70S. THUS
CUTTING BACK ON POPS OUTSIDE OF THE FAR SW LATE WITH THINGS
TURNING BREEZY/MILD UNDER PARTLY SUNNY SKIES PER DRY AIR ALOFT.
WEAK RESIDUAL WARM FRONT WILL LIFT NE THROUGH THE REGION OVERNIGHT
RESULTING IN ADDED LOW LEVEL MOISTURE RETURN AS DEWPOINTS LOOK TO SURGE
INTO THE 50S. HOWEVER MOISTURE DEPTH WILL BE SHALLOW AND STILL LIMITED
BY MID LEVEL DRY AIR...SO POPS QUITE IFFY DURING THE EVENING AND MOSTLY
CONFINED TO THE FAR WEST AT BEST WHERE WILL KEEP SOME LOW CHANCE POPS.
UPPER LOW ACROSS THE MIDWEST SHOULD DRIFT MORE EASTWARD LATE TONIGHT
ALLOWING THE TRAILING SURFACE COLD FRONT TO WORK INTO THE OHIO/TN
VALLEY REGION BY DAYBREAK. GUIDANCE SUGGESTS POSSIBLE MULTIPLE BANDS OR
CLUSTERS OF DISORGANIZED SHOWERS LIKELY WITHIN THE PRE-FRONTAL AXIS OF
DEEP MOISTURE THAT LOOK TO PUSH OUT TO ALONG THE BLUE RIDGE. AGAIN THE
GFS REMAINS THE FASTEST WITH THE 00Z ECMWF MUCH SLOWER WITH SHOWERS
JUST TOUCHING THE FAR WESTERN COUNTIES BY 12Z. SINCE THE REMAINDER OF
THE SOLUTIONS AS WELL AS THE LATEST SREF SHOWING AT LEAST SOME SHOWERS
ACROSS THE MOUNTAINS...WILL CARRY MID LEVEL CHANCE POPS WEST OVERNIGHT
AND LOWER POPS EAST. OTRW BECOMING MOSTLY CLOUDY BUT QUITE MILD UNDER
SW BREEZES AND INCREASING MOISTURE WITH LOWS ONLY 50S TO AROUND 60 IN
SPOTS.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
AS OF 235 AM EDT THURSDAY...
A COLD FRONT WILL MOVE EAST ACROSS THE REGION FRIDAY INTO FRIDAY
NIGHT. SHOWERS AND THUNDERSTORMS ARE EXPECTED AHEAD AND ALONG THE
FRONT. SURFACE BASED CAPE VARIES AVERAGE AROUND 500-1000 J/KG AND
SURFACE BASED LIFTED INDICES ARE AROUND -2. THE DAY TWO CONVECTIVE
OUTLOOK PLACES OUR ENTIRE FORECAST AREA IN GENERAL THUNDERSTORMS
WITH A MARGINAL THREAT TO OUR SOUTH ACROSS ALABAMA AND GEORGIA.
HIGH TEMPERATURES FRIDAY WILL RANGE FROM THE MID 60S IN THE
MOUNTAINS TO THE MID 70S IN THE PIEDMONT.
THE FRONT WILL EXIT THE AREA FRIDAY NIGHT WITH THE GREATEST
ABUNDANCE OF LINGERING SHOWERS ACROSS THE SOUTHEAST PORTION OF THE
AREA. LOW TEMPERATURES FRIDAY NIGHT WILL VARY FROM THE MID 40S IN
THE NORTHWEST MOUNTAINS TO THE MID 50S IN THE PIEDMONT.
ISOLATED SHOWERS WILL ALSO BE ASSOCIATED WITH PASSAGE OF THE 850 MB
FRONT AND INCREASING NORTHWEST FLOW ACROSS PARTS OF SOUTHEAST WEST
VIRGINIA. THIS SHOWERS WILL LINGER SATURDAY MORNING. HIGH PRESSURE
WILL BUILD INTO THE AREA BY SATURDAY AFTERNOON BEHIND THE DEPARTING
COLD FRONT. HIGH TEMPERATURES SATURDAY WILL REACH READINGS FROM THE
UPPER 50S IN THE MOUNTAINS TO THE MID 70S IN THE PIEDMONT.
HIGH PRESSURE WILL SLOWLY BUILD EAST ACROSS OUR AREA SATURDAY NIGHT
INTO SUNDAY. LOW TEMPERATURES SATURDAY WILL DROP TO AROUND 40 IN THE
COLDER MOUNTAINS VALLEYS TO NEAR 50 DEGREES IN THE PIEDMONT. SUNDAY
HIGH TEMPERATURES WILL WARM TO 70 DEGREES IN THE MOUNTAINS AND
APPROACH 80 DEGREES IN THE PIEDMONT.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
AS OF 200 AM EDT THURSDAY...
AN AXIS OF HIGH PRESSURE WILL SLOWLY PROGRESS ACROSS THE REGION INTO
EARLY NEXT WEEK. DRY AND PROGRESSIVELY MILDER CONDITIONS
ARE EXPECTED.
MONDAY NIGHT INTO WEDNESDAY...GUIDANCE IS VARIABLE REGARDING THE
APPROACH AND POSSIBLE PASSAGE OF A COLD FRONT. THE GFS IS MORE
PROGRESSIVE WHILE THE ECMWF IS SLOWER BY AROUND HALF OF A DAY.
ALSO...DIFFERENCES EXIST REGARDING A POTENTIAL SOUTHERLY WAVE MOVING
NORTHEAST ALONG THE FRONT ON WEDNESDAY...THAT BUCKLES THE FEATURE
BACK INTO OUR REGION. OUR FORECAST SOLUTION WILL REFLECT CLOSER TO
THAT OF THE ECMWF THAT HAS A SLOWER PROGRESSION...AND ALLOWS FOR
GREATER IMPACT FROM THE SOUTHERLY WAVE AND MORE ROBUST DAY OF
PRECIPITATION AND COOLER CONDITIONS ON WEDNESDAY.
TEMPERATURES WILL TREND MILDER DURING THIS PORTION OF THE FORECAST
THROUGH TUESDAY WHEN READINGS WILL AVERAGE FIVE TO TEN DEGREES ABOVE
NORMAL. WEDNESDAY IS EXPECTED TO BE COOLER WITH CLOUDS AND
PRECIPITATION ACROSS THE AREA.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 130 PM EDT THURSDAY...
MVFR HAVE ERODED ACROSS THE AREA. LOCAL NWS RADAR SHOWED ISOLATED
SHOWERS HAVE DEVELOPED ALONG THE WEST VIRGINIA/VIRGINIA BORDER.
SHORT TERM MODELS ALSO SUGGEST SHOWERS MAY DEVELOP THIS AFTERNOON
AROUND KDAN AND TO THE EAST AND SOUTH. EXPECT MIXING TO CONTINUE
THIS AFTERNOON WITH GUSTS FROM THE SOUTHWEST UP TO 25 KNOTS.
THE BAND OF SHOWERS FROM OHIO INTO WESTERN TENNESSEE WILL MOVE
TONIGHT...REACHING THE MOUNTAINS AROUND MIDNIGHT AND PROGRESSING
EAST ACROSS THE REGION THROUGH FRIDAY MORNING. ONLY MEDIUM
CONFIDENCE ON THE TIMING OF THIS PRECIPITATION WITH THE MODELS
TRENDS SLOWING DOWN THE ARRIVAL TIME OF THE SHOWERS. THE UPSTREAM
COLD FRONT. SOME IFR CEILINGS ARE POSSIBLE IN THE
MOUNTAINS...ESPECIALLY AT KLWB AND KBLF FRIDAY AFTERNOON BUT
CONFIDENCE IN OCCURRENCE IS LOW.
EXTENDED AVIATION DISCUSSION...
AN UPPER LEVEL LOW PRESSURE SYSTEM ALONG WITH A COLD FRONT OVER
THE MIDWEST STATES WILL BEGIN TO BRING AN INCREASE IN DEEPER
MOISTURE AND COULD RESULT IN PERIODS OF SUB-VFR CEILINGS AS WELL
AS SHOWERS AND ISOLATED THUNDERSTORMS FRIDAY NIGHT AND SATURDAY
MORNING....WITH BEST PROBABILITY OF MVFR CONDITIONS IN THE
MOUNTAINS.
VFR SHOULD RETURN BEHIND THE FRONT FOR SUNDAY AND MONDAY AS HIGH
PRESSURE CROSSES THE REGION. HOWEVER SOME LOWER CIGS MIGHT
REDEVELOP ACROSS THE MOUNTAINS BY SUNDAY AS LIGHT EASTERLY FLOW
SETS UP UNDER ANOTHER WEAK WEDGE WHICH SHOULD FADE BY EARLY NEXT
WEEK.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH
NEAR TERM...JH/SK
SHORT TERM...KK
LONG TERM...DS/KK
AVIATION...AMS/JH
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1143 AM EDT THU APR 21 2016
.SYNOPSIS...
HIGH PRESSURE ALONG THE COAST WILL CONTINUE TO MOVE EAST AND
OFFSHORE TODAY. A WARM FRONT WILL PASS NORTHEAST THROUGH THE
REGION TONIGHT AHEAD OF AN APPROACHING COLD FRONT THAT WILL
REMAIN JUST WEST OF THE MOUNTAINS THROUGH EARLY FRIDAY. THIS
FRONT SHOULD PUSH EAST ACROSS THE AREA FRIDAY AFTERNOON BRINGING
A BETTER CHANCE OF MORE WIDESPREAD SHOWERS AND A FEW THUNDERSTORMS
INTO FRIDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1145 AM EDT THURSDAY...
ANOTHER MINOR UPDATE TO ACCOUNT FOR CLEARING STRATUS DECK IN EAST
AND ALSO DEEPER MIXING THAN PREVIOUSLY THOUGHT...LIKELY RESULTING
IN SOME STRONGER WIND GUSTS THROUGH THE AFTERNOON...IN THE 16 TO
24 MPH RANGE IN THE MOUNTAINS. TONGUE OF HIGHER DEW PT AIR HAS
PUSHED INTO THE NC FOOTHILLS BUT SHOULD MIX OUT OVER NEXT COUPLE
HOURS SO MADE SOME MINOR ADJUSTMENTS FOR THAT AS WELL. OTHERWISE
NO OTHER CHANGES AT THIS TIME.
PREV DISCUSSION AS OF 958 AM EDT THURSDAY...
BROKEN STRATUS DECK FROM MOIST SOUTHEASTERLY LOW LEVEL FLOW
BEGINNING TO ERODE QUICKLY WEST OF THE BLUE RIDGE...AND SATELLITE
AS WELL AS NEAR TERM MODELS SUGGEST THAT WILL CONTINUE FAIRLY
QUICKLY EAST OF BLUE RIDGE AS WELL. MEANWHILE...CLOUD COVER ACROSS
TN...KY...WV IS MAINLY MID TO HIGH AND FAIRLY THIN AND SO DO NOT
THINK THIS WILL HAVE MUCH IMPACT ON TEMPS. THUS BUMPED UP HIGH
TEMPS A FEW DEG AND HOPE THAT IS ENOUGH...AND ALSO REDUCED CLOUD
COVER SOMEWHAT.
HRRR AND SOME OTHER HI RES MODELS SUGGEST JUST BARELY ENOUGH
INSTABILITY IN CENTRAL NC AND VA TO GENERATE AN ISOLATED LATE
AFTERNOON SHOWER...BUT MOST LIKELY THIS WILL REMAIN JUST EAST OF
OUR FORECAST AREA...SO KEPT POPS BELOW 15 PERCENT BUT DID NUDGE
UPWARD AND WILL NEED TO MONITOR THIS AREA LATER TODAY FOR ANY
DEVELOPMENT IN CASE IT IS A LITTLE FARTHER WEST THAN EXPECTED.
OTHERWISE...MOST GUIDANCE CONTINUES TO SLOW DOWN APPROACH OF ANY
PRECIP AHEAD OF THE FRONT THAT IS CURRENTLY OVER NEAR THE
MISSISSIPPI RIVER. MAY NOT BE WORTH MENTIONING CHANCE POPS EVEN
IN FAR WEST UNTIL WELL AFTER MIDNIGHT. HRRR DOES SUGGEST SOME
SHOWERS ARRIVE IN FAR SW VA AROUND MIDNIGHT...BUT OTHER GUIDANCE
SHOWS THESE DISSIPATING AS THEY MOVE IN TO SOMEWHAT DRIER AIR.
THUS CONTINUED THE TREND OF REDUCING POPS THIS EVENING TO SLIGHT
CHC OR LESS...AND MAY NEED TO DO THIS EVEN MORE ON FUTURE UPDATES.
PREV DISCUSSION AS OF 222 AM EDT THURSDAY...
MOISTURE TO GRADUALLY RETURN ACROSS THE REGION OVER THE NEXT 24 HOURS
AS THE SURFACE-85H FLOW QUICKLY VEERS FROM SE THIS MORNING TO SW WHILE
INCREASING THIS AFTERNOON/OVERNIGHT AHEAD OF THE COLD FRONT TO THE
WEST. THIS LOW LOW LEVEL SOUTH/SE FLOW THIS MORNING WILL AGAIN ADVECT
LOW CLOUDS NOW OVER NORTH CAROLINA INTO AREAS MAINLY ALONG/EAST OF THE
BLUE RIDGE BEFORE GETTING BOOTED EAST THIS AFTERNOON AS THE FLOW TURNS
MORE SW. COULD EVEN SEE A SPOTTY LIGHT SHOWER OR SPOT OR TWO OF DRIZZLE
SOUTHERN BLUE RIDGE AND POINTS EAST THIS MORNING SO INCLUDED SOME
MENTION TO INIT. LATEST GUIDANCE INDICATES THAT MOST OF THE LOW CLOUDS
SHOULD BE EAST OF THE CWA BY MID AFTERNOON ALLOWING DEEPENING WARM
ADVECTION TO RETURN UNDER MOSTLY SHEARED MID/HIGH CLOUDS WITH
CONVECTION ALONG THE COLD FRONT TO THE WEST. MOISTURE ALONG WITH
LIFT/INSTABILITY APPEARS TOO LACKING TO PRODUCE MUCH IN THE WAY OF
SHOWERS THIS AFTERNOON DESPITE TEMPS WARMING BACK INTO THE 70S. THUS
CUTTING BACK ON POPS OUTSIDE OF THE FAR SW LATE WITH THINGS
TURNING BREEZY/MILD UNDER PARTLY SUNNY SKIES PER DRY AIR ALOFT.
WEAK RESIDUAL WARM FRONT WILL LIFT NE THROUGH THE REGION OVERNIGHT
RESULTING IN ADDED LOW LEVEL MOISTURE RETURN AS DEWPOINTS LOOK TO SURGE
INTO THE 50S. HOWEVER MOISTURE DEPTH WILL BE SHALLOW AND STILL LIMITED
BY MID LEVEL DRY AIR...SO POPS QUITE IFFY DURING THE EVENING AND MOSTLY
CONFINED TO THE FAR WEST AT BEST WHERE WILL KEEP SOME LOW CHANCE POPS.
UPPER LOW ACROSS THE MIDWEST SHOULD DRIFT MORE EASTWARD LATE TONIGHT
ALLOWING THE TRAILING SURFACE COLD FRONT TO WORK INTO THE OHIO/TN
VALLEY REGION BY DAYBREAK. GUIDANCE SUGGESTS POSSIBLE MULTIPLE BANDS OR
CLUSTERS OF DISORGANIZED SHOWERS LIKELY WITHIN THE PRE-FRONTAL AXIS OF
DEEP MOISTURE THAT LOOK TO PUSH OUT TO ALONG THE BLUE RIDGE. AGAIN THE
GFS REMAINS THE FASTEST WITH THE 00Z ECMWF MUCH SLOWER WITH SHOWERS
JUST TOUCHING THE FAR WESTERN COUNTIES BY 12Z. SINCE THE REMAINDER OF
THE SOLUTIONS AS WELL AS THE LATEST SREF SHOWING AT LEAST SOME SHOWERS
ACROSS THE MOUNTAINS...WILL CARRY MID LEVEL CHANCE POPS WEST OVERNIGHT
AND LOWER POPS EAST. OTRW BECOMING MOSTLY CLOUDY BUT QUITE MILD UNDER
SW BREEZES AND INCREASING MOISTURE WITH LOWS ONLY 50S TO AROUND 60 IN
SPOTS.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
AS OF 235 AM EDT THURSDAY...
A COLD FRONT WILL MOVE EAST ACROSS THE REGION FRIDAY INTO FRIDAY
NIGHT. SHOWERS AND THUNDERSTORMS ARE EXPECTED AHEAD AND ALONG THE
FRONT. SURFACE BASED CAPE VARIES AVERAGE AROUND 500-1000 J/KG AND
SURFACE BASED LIFTED INDICES ARE AROUND -2. THE DAY TWO CONVECTIVE
OUTLOOK PLACES OUR ENTIRE FORECAST AREA IN GENERAL THUNDERSTORMS
WITH A MARGINAL THREAT TO OUR SOUTH ACROSS ALABAMA AND GEORGIA.
HIGH TEMPERATURES FRIDAY WILL RANGE FROM THE MID 60S IN THE
MOUNTAINS TO THE MID 70S IN THE PIEDMONT.
THE FRONT WILL EXIT THE AREA FRIDAY NIGHT WITH THE GREATEST
ABUNDANCE OF LINGERING SHOWERS ACROSS THE SOUTHEAST PORTION OF THE
AREA. LOW TEMPERATURES FRIDAY NIGHT WILL VARY FROM THE MID 40S IN
THE NORTHWEST MOUNTAINS TO THE MID 50S IN THE PIEDMONT.
ISOLATED SHOWERS WILL ALSO BE ASSOCIATED WITH PASSAGE OF THE 850 MB
FRONT AND INCREASING NORTHWEST FLOW ACROSS PARTS OF SOUTHEAST WEST
VIRGINIA. THIS SHOWERS WILL LINGER SATURDAY MORNING. HIGH PRESSURE
WILL BUILD INTO THE AREA BY SATURDAY AFTERNOON BEHIND THE DEPARTING
COLD FRONT. HIGH TEMPERATURES SATURDAY WILL REACH READINGS FROM THE
UPPER 50S IN THE MOUNTAINS TO THE MID 70S IN THE PIEDMONT.
HIGH PRESSURE WILL SLOWLY BUILD EAST ACROSS OUR AREA SATURDAY NIGHT
INTO SUNDAY. LOW TEMPERATURES SATURDAY WILL DROP TO AROUND 40 IN THE
COLDER MOUNTAINS VALLEYS TO NEAR 50 DEGREES IN THE PIEDMONT. SUNDAY
HIGH TEMPERATURES WILL WARM TO 70 DEGREES IN THE MOUNTAINS AND
APPROACH 80 DEGREES IN THE PIEDMONT.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
AS OF 200 AM EDT THURSDAY...
AN AXIS OF HIGH PRESSURE WILL SLOWLY PROGRESS ACROSS THE REGION INTO
EARLY NEXT WEEK. DRY AND PROGRESSIVELY MILDER CONDITIONS
ARE EXPECTED.
MONDAY NIGHT INTO WEDNESDAY...GUIDANCE IS VARIABLE REGARDING THE
APPROACH AND POSSIBLE PASSAGE OF A COLD FRONT. THE GFS IS MORE
PROGRESSIVE WHILE THE ECMWF IS SLOWER BY AROUND HALF OF A DAY.
ALSO...DIFFERENCES EXIST REGARDING A POTENTIAL SOUTHERLY WAVE MOVING
NORTHEAST ALONG THE FRONT ON WEDNESDAY...THAT BUCKLES THE FEATURE
BACK INTO OUR REGION. OUR FORECAST SOLUTION WILL REFLECT CLOSER TO
THAT OF THE ECMWF THAT HAS A SLOWER PROGRESSION...AND ALLOWS FOR
GREATER IMPACT FROM THE SOUTHERLY WAVE AND MORE ROBUST DAY OF
PRECIPITATION AND COOLER CONDITIONS ON WEDNESDAY.
TEMPERATURES WILL TREND MILDER DURING THIS PORTION OF THE FORECAST
THROUGH TUESDAY WHEN READINGS WILL AVERAGE FIVE TO TEN DEGREES ABOVE
NORMAL. WEDNESDAY IS EXPECTED TO BE COOLER WITH CLOUDS AND
PRECIPITATION ACROSS THE AREA.
&&
.AVIATION /16Z THURSDAY THROUGH MONDAY/...
AS OF 645 AM EDT THURSDAY...
MVFR TO OCNL IFR CIGS HAVE OVERSPREAD MUCH OF THE REGION...MAINLY
ALONG AND EAST OF THE BLUE RIDGE EARLY THIS MORNING...WITH MOSTLY
VFR TO THE NW AT KBLF/KLWB WHERE ON THE EDGE OF THE CANOPY.
LATEST GUIDANCE CONTINUES TO SHOW MUCH OF THIS LOWER CLOUD COVER
PERSISTING AND POSSIBLY BRIEFLY BACKING INTO THE SE WEST VA SITES
BEFORE SHIFTING EAST BY MID TO LATE MORNING. HOWEVER TIMING OF
IMPROVING CONDITIONS REMAINS IFFY WITH TRENDS SUGGESTING THAT MVFR
CIGS COULD LINGER EAST OF THE BLUE RIDGE UNTIL EARLY AFTERNOON. THUS
HAVE LOWERED CLOUD BASES A BIT MORE AS CURRENT OBS SUPPORT SOME
BRIEF IFR CIGS AND SPOTTY -SHRA BEFORE THE FLOW TURNS MORE
SOUTH/SW BY AFTERNOON AND THINGS MIX OUT PER LATEST BUFKIT RAOBS.
OTHERWISE MODELS SEEM TO HAVE A GOOD HANDLE ON THE LOW LEVEL
MOISTURE AND BEGIN PULLING IT OUT TO THE EAST BY THIS AFTERNOON
WITH ALL SITES VFR BY EARLY TO MID AFTERNOON IF NOT SOONER. WINDS
WILL GENERALLY BE LIGHT WITH SOME DIURNAL GUSTY CONDITIONS
BECOMING ESTABLISHED LATE THIS MORNING...AND THEN INCREASING FROM
THE SOUTH/SW AS THE LOW LEVEL JET PICKS UP. COULD SEE SOME GUSTS
TO 20-25 KNOTS ONCE LOW CLOUDS EXIT LEAVING MAINLY MID AND HIGH
CLOUDS DURING THE AFTERNOON.
WEAK WARM FRONT WILL DRIFT NORTH THROUGH THE AREA OVERNIGHT WHILE
DEEPER MOISTURE SHOULD REMAIN LIMITED TO AREAS JUST WEST OF THE
MOUNTAINS UNTIL LATE TONIGHT. BANDS OF SHOWERS COULD WORK EAST
INTO THE KBLF/KLWB VICINITY WELL AFTER MIDNIGHT WITH THE APPROACH
OF THE UPSTREAM COLD FRONT. HOWEVER SLOWER MODEL TIMING WOULD
SUGGEST THAT MOST AREAS WILL STAY VFR OVERNIGHT UNTIL LATE WHEN
CIGS COULD FALL INTO MVFR LEVELS MOUNTAINS WITH SHRA POSSIBLE.
EXTENDED AVIATION DISCUSSION...
AN UPPER LEVEL LOW PRESSURE SYSTEM ALONG WITH A COLD FRONT OVER
THE MIDWEST STATES WILL BEGIN TO BRING AN INCREASE IN DEEPER
MOISTURE AND COULD RESULT IN PERIODS OF SUB-VFR CEILINGS AS WELL
AS SHOWERS AND ISOLATED THUNDERSTORMS FRIDAY....WITH BEST
PROBABILITY IN THE MOUNTAINS FRIDAY MORNING AND OUT EAST IN THE
AFTERNOON. VFR SHOULD RETURN BEHIND THE FRONT FOR THE WEEKEND INTO
MONDAY AS HIGH PRESSURE CROSSES THE REGION. HOWEVER SOME LOWER
CIGS MIGHT REDEVELOP ACROSS THE MOUNTAINS BY SUNDAY AS LIGHT
EASTERLY FLOW SETS UP UNDER ANOTHER WEAK WEDGE WHICH SHOULD FADE
BY EARLY NEXT WEEK.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH
NEAR TERM...JH/SK
SHORT TERM...KK
LONG TERM...DS/KK
AVIATION...AMS/JH/MBS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1000 AM EDT THU APR 21 2016
.SYNOPSIS...
HIGH PRESSURE ALONG THE COAST WILL CONTINUE TO MOVE EAST AND
OFFSHORE TODAY. A WARM FRONT WILL PASS NORTHEAST THROUGH THE
REGION TONIGHT AHEAD OF AN APPROACHING COLD FRONT THAT WILL
REMAIN JUST WEST OF THE MOUNTAINS THROUGH EARLY FRIDAY. THIS
FRONT SHOULD PUSH EAST ACROSS THE AREA FRIDAY AFTERNOON BRINGING
A BETTER CHANCE OF MORE WIDESPREAD SHOWERS AND A FEW THUNDERSTORMS
INTO FRIDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 958 AM EDT THURSDAY...
BROKEN STRATUS DECK FROM MOIST SOUTHEASTERLY LOW LEVEL FLOW
BEGINNING TO ERODE QUICKLY WEST OF THE BLUE RIDGE...AND SATELLITE
AS WELL AS NEAR TERM MODELS SUGGEST THAT WILL CONTINUE FAIRLY
QUICKLY EAST OF BLUE RIDGE AS WELL. MEANWHILE...CLOUD COVER ACROSS
TN...KY...WV IS MAINLY MID TO HIGH AND FAIRLY THIN AND SO DO NOT
THINK THIS WILL HAVE MUCH IMPACT ON TEMPS. THUS BUMPED UP HIGH
TEMPS A FEW DEG AND HOPE THAT IS ENOUGH...AND ALSO REDUCED CLOUD
COVER SOMEWHAT.
HRRR AND SOME OTHER HI RES MODELS SUGGEST JUST BARELY ENOUGH
INSTABILITY IN CENTRAL NC AND VA TO GENERATE AN ISOLATED LATE
AFTERNOON SHOWER...BUT MOST LIKELY THIS WILL REMAIN JUST EAST OF
OUR FORECAST AREA...SO KEPT POPS BELOW 15 PERCENT BUT DID NUDGE
UPWARD AND WILL NEED TO MONITOR THIS AREA LATER TODAY FOR ANY
DEVELOPMENT IN CASE IT IS A LITTLE FARTHER WEST THAN EXPECTED.
OTHERWISE...MOST GUIDANCE CONTINUES TO SLOW DOWN APPROACH OF ANY
PRECIP AHEAD OF THE FRONT THAT IS CURRENTLY OVER NEAR THE
MISSISSIPPI RIVER. MAY NOT BE WORTH MENTIONING CHANCE POPS EVEN
IN FAR WEST UNTIL WELL AFTER MIDNIGHT. HRRR DOES SUGGEST SOME
SHOWERS ARRIVE IN FAR SW VA AROUND MIDNIGHT...BUT OTHER GUIDANCE
SHOWS THESE DISSIPATING AS THEY MOVE IN TO SOMEWHAT DRIER AIR.
THUS CONTINUED THE TREND OF REDUCING POPS THIS EVENING TO SLIGHT
CHC OR LESS...AND MAY NEED TO DO THIS EVEN MORE ON FUTURE UPDATES.
AS OF 222 AM EDT THURSDAY...
MOISTURE TO GRADUALLY RETURN ACROSS THE REGION OVER THE NEXT 24 HOURS
AS THE SURFACE-85H FLOW QUICKLY VEERS FROM SE THIS MORNING TO SW WHILE
INCREASING THIS AFTERNOON/OVERNIGHT AHEAD OF THE COLD FRONT TO THE
WEST. THIS LOW LOW LEVEL SOUTH/SE FLOW THIS MORNING WILL AGAIN ADVECT
LOW CLOUDS NOW OVER NORTH CAROLINA INTO AREAS MAINLY ALONG/EAST OF THE
BLUE RIDGE BEFORE GETTING BOOTED EAST THIS AFTERNOON AS THE FLOW TURNS
MORE SW. COULD EVEN SEE A SPOTTY LIGHT SHOWER OR SPOT OR TWO OF DRIZZLE
SOUTHERN BLUE RIDGE AND POINTS EAST THIS MORNING SO INCLUDED SOME
MENTION TO INIT. LATEST GUIDANCE INDICATES THAT MOST OF THE LOW CLOUDS
SHOULD BE EAST OF THE CWA BY MID AFTERNOON ALLOWING DEEPENING WARM
ADVECTION TO RETURN UNDER MOSTLY SHEARED MID/HIGH CLOUDS WITH
CONVECTION ALONG THE COLD FRONT TO THE WEST. MOISTURE ALONG WITH
LIFT/INSTABILITY APPEARS TOO LACKING TO PRODUCE MUCH IN THE WAY OF
SHOWERS THIS AFTERNOON DESPITE TEMPS WARMING BACK INTO THE 70S. THUS
CUTTING BACK ON POPS OUTSIDE OF THE FAR SW LATE WITH THINGS
TURNING BREEZY/MILD UNDER PARTLY SUNNY SKIES PER DRY AIR ALOFT.
WEAK RESIDUAL WARM FRONT WILL LIFT NE THROUGH THE REGION OVERNIGHT
RESULTING IN ADDED LOW LEVEL MOISTURE RETURN AS DEWPOINTS LOOK TO SURGE
INTO THE 50S. HOWEVER MOISTURE DEPTH WILL BE SHALLOW AND STILL LIMITED
BY MID LEVEL DRY AIR...SO POPS QUITE IFFY DURING THE EVENING AND MOSTLY
CONFINED TO THE FAR WEST AT BEST WHERE WILL KEEP SOME LOW CHANCE POPS.
UPPER LOW ACROSS THE MIDWEST SHOULD DRIFT MORE EASTWARD LATE TONIGHT
ALLOWING THE TRAILING SURFACE COLD FRONT TO WORK INTO THE OHIO/TN
VALLEY REGION BY DAYBREAK. GUIDANCE SUGGESTS POSSIBLE MULTIPLE BANDS OR
CLUSTERS OF DISORGANIZED SHOWERS LIKELY WITHIN THE PRE-FRONTAL AXIS OF
DEEP MOISTURE THAT LOOK TO PUSH OUT TO ALONG THE BLUE RIDGE. AGAIN THE
GFS REMAINS THE FASTEST WITH THE 00Z ECMWF MUCH SLOWER WITH SHOWERS
JUST TOUCHING THE FAR WESTERN COUNTIES BY 12Z. SINCE THE REMAINDER OF
THE SOLUTIONS AS WELL AS THE LATEST SREF SHOWING AT LEAST SOME SHOWERS
ACROSS THE MOUNTAINS...WILL CARRY MID LEVEL CHANCE POPS WEST OVERNIGHT
AND LOWER POPS EAST. OTRW BECOMING MOSTLY CLOUDY BUT QUITE MILD UNDER
SW BREEZES AND INCREASING MOISTURE WITH LOWS ONLY 50S TO AROUND 60 IN
SPOTS.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
AS OF 235 AM EDT THURSDAY...
A COLD FRONT WILL MOVE EAST ACROSS THE REGION FRIDAY INTO FRIDAY
NIGHT. SHOWERS AND THUNDERSTORMS ARE EXPECTED AHEAD AND ALONG THE
FRONT. SURFACE BASED CAPE VARIES AVERAGE AROUND 500-1000 J/KG AND
SURFACE BASED LIFTED INDICES ARE AROUND -2. THE DAY TWO CONVECTIVE
OUTLOOK PLACES OUR ENTIRE FORECAST AREA IN GENERAL THUNDERSTORMS
WITH A MARGINAL THREAT TO OUR SOUTH ACROSS ALABAMA AND GEORGIA.
HIGH TEMPERATURES FRIDAY WILL RANGE FROM THE MID 60S IN THE
MOUNTAINS TO THE MID 70S IN THE PIEDMONT.
THE FRONT WILL EXIT THE AREA FRIDAY NIGHT WITH THE GREATEST
ABUNDANCE OF LINGERING SHOWERS ACROSS THE SOUTHEAST PORTION OF THE
AREA. LOW TEMPERATURES FRIDAY NIGHT WILL VARY FROM THE MID 40S IN
THE NORTHWEST MOUNTAINS TO THE MID 50S IN THE PIEDMONT.
ISOLATED SHOWERS WILL ALSO BE ASSOCIATED WITH PASSAGE OF THE 850 MB
FRONT AND INCREASING NORTHWEST FLOW ACROSS PARTS OF SOUTHEAST WEST
VIRGINIA. THIS SHOWERS WILL LINGER SATURDAY MORNING. HIGH PRESSURE
WILL BUILD INTO THE AREA BY SATURDAY AFTERNOON BEHIND THE DEPARTING
COLD FRONT. HIGH TEMPERATURES SATURDAY WILL REACH READINGS FROM THE
UPPER 50S IN THE MOUNTAINS TO THE MID 70S IN THE PIEDMONT.
HIGH PRESSURE WILL SLOWLY BUILD EAST ACROSS OUR AREA SATURDAY NIGHT
INTO SUNDAY. LOW TEMPERATURES SATURDAY WILL DROP TO AROUND 40 IN THE
COLDER MOUNTAINS VALLEYS TO NEAR 50 DEGREES IN THE PIEDMONT. SUNDAY
HIGH TEMPERATURES WILL WARM TO 70 DEGREES IN THE MOUNTAINS AND
APPROACH 80 DEGREES IN THE PIEDMONT.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
AS OF 200 AM EDT THURSDAY...
AN AXIS OF HIGH PRESSURE WILL SLOWLY PROGRESS ACROSS THE REGION INTO
EARLY NEXT WEEK. DRY AND PROGRESSIVELY MILDER CONDITIONS
ARE EXPECTED.
MONDAY NIGHT INTO WEDNESDAY...GUIDANCE IS VARIABLE REGARDING THE
APPROACH AND POSSIBLE PASSAGE OF A COLD FRONT. THE GFS IS MORE
PROGRESSIVE WHILE THE ECMWF IS SLOWER BY AROUND HALF OF A DAY.
ALSO...DIFFERENCES EXIST REGARDING A POTENTIAL SOUTHERLY WAVE MOVING
NORTHEAST ALONG THE FRONT ON WEDNESDAY...THAT BUCKLES THE FEATURE
BACK INTO OUR REGION. OUR FORECAST SOLUTION WILL REFLECT CLOSER TO
THAT OF THE ECMWF THAT HAS A SLOWER PROGRESSION...AND ALLOWS FOR
GREATER IMPACT FROM THE SOUTHERLY WAVE AND MORE ROBUST DAY OF
PRECIPITATION AND COOLER CONDITIONS ON WEDNESDAY.
TEMPERATURES WILL TREND MILDER DURING THIS PORTION OF THE FORECAST
THROUGH TUESDAY WHEN READINGS WILL AVERAGE FIVE TO TEN DEGREES ABOVE
NORMAL. WEDNESDAY IS EXPECTED TO BE COOLER WITH CLOUDS AND
PRECIPITATION ACROSS THE AREA.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
AS OF 645 AM EDT THURSDAY...
MVFR TO OCNL IFR CIGS HAVE OVERSPREAD MUCH OF THE REGION...MAINLY
ALONG AND EAST OF THE BLUE RIDGE EARLY THIS MORNING...WITH MOSTLY
VFR TO THE NW AT KBLF/KLWB WHERE ON THE EDGE OF THE CANOPY.
LATEST GUIDANCE CONTINUES TO SHOW MUCH OF THIS LOWER CLOUD COVER
PERSISTING AND POSSIBLY BRIEFLY BACKING INTO THE SE WEST VA SITES
BEFORE SHIFTING EAST BY MID TO LATE MORNING. HOWEVER TIMING OF
IMPROVING CONDITIONS REMAINS IFFY WITH TRENDS SUGGESTING THAT MVFR
CIGS COULD LINGER EAST OF THE BLUE RIDGE UNTIL EARLY AFTERNOON. THUS
HAVE LOWERED CLOUD BASES A BIT MORE AS CURRENT OBS SUPPORT SOME
BRIEF IFR CIGS AND SPOTTY -SHRA BEFORE THE FLOW TURNS MORE
SOUTH/SW BY AFTERNOON AND THINGS MIX OUT PER LATEST BUFKIT RAOBS.
OTHERWISE MODELS SEEM TO HAVE A GOOD HANDLE ON THE LOW LEVEL
MOISTURE AND BEGIN PULLING IT OUT TO THE EAST BY THIS AFTERNOON
WITH ALL SITES VFR BY EARLY TO MID AFTERNOON IF NOT SOONER. WINDS
WILL GENERALLY BE LIGHT WITH SOME DIURNAL GUSTY CONDITIONS
BECOMING ESTABLISHED LATE THIS MORNING...AND THEN INCREASING FROM
THE SOUTH/SW AS THE LOW LEVEL JET PICKS UP. COULD SEE SOME GUSTS
TO 20-25 KNOTS ONCE LOW CLOUDS EXIT LEAVING MAINLY MID AND HIGH
CLOUDS DURING THE AFTERNOON.
WEAK WARM FRONT WILL DRIFT NORTH THROUGH THE AREA OVERNIGHT WHILE
DEEPER MOISTURE SHOULD REMAIN LIMITED TO AREAS JUST WEST OF THE
MOUNTAINS UNTIL LATE TONIGHT. BANDS OF SHOWERS COULD WORK EAST
INTO THE KBLF/KLWB VICINITY WELL AFTER MIDNIGHT WITH THE APPROACH
OF THE UPSTREAM COLD FRONT. HOWEVER SLOWER MODEL TIMING WOULD
SUGGEST THAT MOST AREAS WILL STAY VFR OVERNIGHT UNTIL LATE WHEN
CIGS COULD FALL INTO MVFR LEVELS MOUNTAINS WITH SHRA POSSIBLE.
EXTENDED AVIATION DISCUSSION...
AN UPPER LEVEL LOW PRESSURE SYSTEM ALONG WITH A COLD FRONT OVER
THE MIDWEST STATES WILL BEGIN TO BRING AN INCREASE IN DEEPER
MOISTURE AND COULD RESULT IN PERIODS OF SUB-VFR CEILINGS AS WELL
AS SHOWERS AND ISOLATED THUNDERSTORMS FRIDAY....WITH BEST
PROBABILITY IN THE MOUNTAINS FRIDAY MORNING AND OUT EAST IN THE
AFTERNOON. VFR SHOULD RETURN BEHIND THE FRONT FOR THE WEEKEND INTO
MONDAY AS HIGH PRESSURE CROSSES THE REGION. HOWEVER SOME LOWER
CIGS MIGHT REDEVELOP ACROSS THE MOUNTAINS BY SUNDAY AS LIGHT
EASTERLY FLOW SETS UP UNDER ANOTHER WEAK WEDGE WHICH SHOULD FADE
BY EARLY NEXT WEEK.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH
NEAR TERM...JH/SK
SHORT TERM...KK
LONG TERM...DS/KK
AVIATION...AMS/JH/MBS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
345 PM CDT THU APR 21 2016
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 344 PM CDT THU APR 21 2016
AT 3 PM...SCATTERED SHOWERS WERE FOUND ACROSS CLARK COUNTY IN
NORTH-CENTRAL WISCONSIN AND NORTHEAST IOWA. BOTH OF THESE WERE
LOCATED ALONG A BAND OF 900 TO 800 MB FRONTOGENESIS. THERE WERE
REPORTS OF A WALL CLOUD AND PEA SIZE HAIL IN DAVENPORT/S FORECAST
AREA. THIS WAS OCCURRING IN AN AREA WHERE THE RAP WAS HIGHLIGHTING
A HIGH POTENTIAL FOR NON SUPERCELL TORNADO PARAMETER /NST/.
THROUGH 21.23Z...THE RAP IS HIGHLIGHTING ANOTHER STRONG AREA OF
NST ACROSS NORTHEAST IOWA AND SOUTHWEST WISCONSIN. THERE IS A
STATIONARY BOUNDARY IN THIS AREA. HOWEVER THE RAP IS 5 TO 8F TOO
HIGH WITH ITS SURFACE DEW POINTS...THEREFORE...ITS CAPES ARE TOO
HIGH. THIS IS LIKELY ENHANCING THE NST VALUE TOO MUCH. AS A
RESULT...WE ARE JUST GOING TO CONTINUE TO MONITOR THIS AREA
CLOSELY AND NOT ISSUE A SPECIAL WEATHER STATEMENT AT THIS TIME.
FOR THIS EVENING...THE 21.12Z AND 21.18Z MODELS CONTINUE TO SHOW
THAT BOTH OF THE 900 TO 800 MB FRONTOGENESIS BANDS WILL SLOWLY
MOVE SOUTHEAST AND WEAKEN. AT THE SAME TIME...THE SURFACE BASED
CAPES AND 900 TO 850 MB LAPSE RATES WILL BE WEAKENING. AS THIS
OCCURS...THE SHOWERS WILL RAPIDLY DISSIPATE BETWEEN 22.03Z AND
22.06Z.
ON FRIDAY MORNING...TEMPERATURES WILL DROP INTO THE MID-30S IN
TAYLOR COUNTY. WHILE THE TEMPERATURES WILL BE COOL FOR THE
POTENTIAL OF SCATTERED FROST...THERE WILL STILL BE A 2 TO 3F
TEMPERATURE-DEW POINT DEPRESSIONS AND THE SURFACE WINDS WILL BE IN
THE 5 TO 10 MPH RANGE. THIS SHOULD DETER THE DEVELOPMENT OF FROST
IN THAT AREA.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 344 PM CDT THU APR 21 2016
ON FRIDAY NIGHT THERE WILL BE MOSTLY CLEAR SKIES AND LIGHT WINDS.
THIS WILL ALLOW THE LOW TEMPERATURES TO FALL INTO THE MID 30S IN
CENTRAL WISCONSIN. THIS MAY RESULT IN SOME PATCHY FROST IN THIS
AREA. WE WILL HAVE TO WATCH THIS AREA CLOSELY FOR A POTENTIAL
FROST ADVISORY.
FROM SATURDAY NIGHT THROUGH MONDAY...AN UPPER LEVEL LOW WILL MOVE
SOUTHEAST THROUGH THE REGION. ON SUNDAY AFTERNOON...THE 0-4 KM
CAPES WILL CLIMB UP TO 750 J/KG SOUTH OF INTERSTATE 90 CORRIDOR
AND THE 0-6 KM SHEAR WILL CLIMB UP TO 45 KNOTS. THIS MAY RESULT IN
THE DEVELOPMENT OF A FEW SUPERCELLS AHEAD OF THE COLD FRONT IN
NORTHEAST IOWA. WE WILL HAVE TO WATCH THIS PERIOD CLOSELY.
FROM TUESDAY NIGHT INTO WEDNESDAY...ANOTHER UPPER LEVEL LOW WILL
MOVE SOUTHEAST THROUGH THE REGION. THERE CONTINUES TO BE DEEP
SHEAR LOCATED SOUTH OF INTERSTATE 94. HOWEVER THE CAPES ARE ONLY
UP TO 500 J/KG. THIS CAPE WILL BE A LIMITING FACTOR FOR ANY THREAT
OF SEVERE WEATHER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1232 PM CDT THU APR 21 2016
LOW PRESSURE TRACKING EAST ACROSS THE AREA TODAY WAS PRODUCING
SCATTERED-BROKEN MAINLY VFR CUMULUS. AS OF NOON THERE WERE NO SHRA
IN THE AREA ON RADAR...BUT STILL EXPECTING WIDELY SCATTERED SHRA
ACTIVITY GOING INTO THIS AFTERNOON/EVENING. SATELLITE WAS SHOWING
SOME MVFR/IFR STRATOCUMULUS UPSTREAM ACROSS NORTHERN MN. THIS
CLOUD GETS PULLED SOUTHEAST ACROSS OUR AREA TONIGHT INTO FRIDAY
MORNING...SCATTERING OUT BY LATER FRIDAY MORNING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...DAS
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1006 AM CDT THU APR 21 2016
.UPDATE...
SHOULD SEE A MIX OF SUN AND CLOUDS TODAY...AS BEGINNING TO SEE
MORE HOLES IN THE CLOUD DECK THIS MORNING. WITH TEMPS ALREADY IN
THE LOW 60S MANY PLACES...FORECAST HIGHS IN THE UPPER 60S SEEM TO
BE ON TRACK. WITH WEAK SURFACE WINDS...WILL LIKELY SEE A LAKE
BREEZE DEVELOP. TEMPS NEAR THE LAKE TODAY WILL BE DEPENDENT ON
TIMING OF HOLES IN THE CLOUDS VS HOW QUICKLY THE LAKE BREEZE MOVES
INLAND. WILL MAINTAIN UPPER 50S AND LOW 60S NEAR THE LAKE FOR NOW.
WILL SEE SOME SCATTERED SHOWERS DEVELOP THIS AFTERNOON...WITH A
LITTLE THUNDER ALSO POSSIBLE. BEST CHANCE FOR SHOWERS/STORMS WILL
BE ACROSS THE SOUTHERN HALF OF THE FORECAST AREA.
&&
.AVIATION/18Z TAFS/...
THERE IS A CHANCE OF SHOWERS THIS AFTERNOON AND EVENING...WITH
CONDITIONS TURNING DRY TONIGHT INTO FRIDAY AS HIGH PRESSURE MOVES
INTO THE AREA.
SOME LOW CIGS/VSBYS WILL LINGER INTO LATE MORNING IN THE
EAST...WITH VFR CONDITIONS LIKELY TO RETURN MOST PLACES THIS
AFTERNOON.
WINDS WILL BE LIGHT AND VARIABLE MUCH OF THE DAY...BECOMING
NORTHERLY AND BREEZY THIS EVENING AND OVERNIGHT AS A COLD FRONT
DROPS SOUTHWARD THROUGH THE FORECAST AREA. LOWER CIGS ARE POSSIBLE
BEHIND THIS FRONT...EVENTUALLY MIXING OUT FRIDAY AFTERNOON.
&&
.MARINE...
DENSE FOG WILL REMAIN A CONCERN FOR THE NEARSHORE WATERS TODAY WITH
A MILD AND MOIST LOW-LEVEL AIRMASS IN PLACE ATOP THE COOLER LAKE
WATERS. LIGHT SOUTH TO SOUTHEASTERLY WINDS WILL CONTINUE...WITH THE
MARINE DENSE FOG ADVISORY REMAINING IN EFFECT UNTIL 00Z FRIDAY.
THEREAFTER...A BACK DOOR COLD FRONT WILL PUSH SOUTH THROUGH THE
COASTAL WATERS FROM ROUGHLY 05Z TO 10Z TONIGHT. EXPECT A RAPID
INCREASE IN WIND GUSTS DURING THIS TIME...ALONG WITH A NORTH TO
NORTHEASTERLY WIND SHIFT FOLLOWING THE FRONTAL PASSAGE. A SMALL
CRAFT ADVISORY FOR WINDS AND WAVES IS IN EFFECT FROM LATE TONIGHT
THROUGH FRIDAY.
&&
.PREV DISCUSSION... /ISSUED 337 AM CDT THU APR 21 2016/
TODAY AND TONIGHT...FORECAST CONFIDENCE - LOW TO MEDIUM.
FORECAST CONCERNS FOCUS ON PRECIP THREAT RETURNING TODAY AND FOG.
DRIER AIR WRAPPING AROUND UPSTREAM LOW PRESSURE ERODING LOW CLOUDS
OVER FAR SOUTHWEST WI AND WILL AFFECT SOUTHWEST CWA NEXT SEVERAL
HOURS. THIS WILL ALLOW FOG TO DEVELOP AND FOG COULD EASILY TURN
DENSE FOR SEVERAL HOURS. WITH EARLIER SUNRISE...WL HOLD OFF ON
ISSUING DENSE FOG ADVY FOR KEFT/KMRJ AREAS AND GO WITH SPS FOR
NOW...HOWEVER MAY NEED TO GO WITH ADVY SHOULD VSBYS RAPIDLY FALL
IN NEXT 1-2 HOURS. FOG SHOULD LIFT AFTER 13Z.
FARTHER EAST...EXPCT SCT -SHRA TO GRADUALLY DIMINISH THRU THE EARLY
MORNING AS LOW LEVEL MOISTURE ADVECTION WEAKENS. HRRR HAS BEEN
SHOWING SCT -SHRA REFORMING OVER CENTRAL AND EASTERN CWA EARLY THIS
MORNING BUT OTHER SHORT TERM GUIDANCE DRIER AND SUCCUMBING TO DRYING
MID-LEVEL AIR FROM THE SOUTHWEST. DIFFICULT TO FIND FORCING
MECHANISM FOR THESE -SHRA DEPICTED BY HRRR...SO WL GO WITH MAINLY
DRY CONDITIONS THIS MRNG ACROSS CENTRAL CWA AND KEEP SMALL CHANCE
FOR LINGERING -SHRA IN EAST FOR A FEW HOURS.
EXPECT LOW CLOUDS TO THIN ACROSS CENTRAL AND MOST OF EASTERN CWA
LATER THIS MRNG BUT MORE CLOUDS AND FOG MAY LINGER CLOSER TO THE
LAKE DUE TO LAKE BREEZE.
DESPITE WEAK SHEAR...DEWPOINTS IN THE 50S AND PARTIAL SUNSHINE
SHOULD RESULT IN MUCAPES INCREASING TO 300 TO 800 J THIS AFTN.
STRONGEST FORCING ASSOCIATED WITH UPPER LOW TO REMAIN TO THE SOUTH
OF THE IL BORDER THIS AFTN...HOWEVER WL STILL HAVE LOW PRESSURE TROF
MOVING THRU SRN WI. IN ADDITION...SRN CWA GETS GRAZED BY STRONGER
SYNOPTIC FORCING FROM LEFT EXIT REGION OF UPPER JET. HENCE EXPECT
SCT SHRA AND A FEW TSTRMS TO DEVELOP OVER CWA THIS AFTN INTO THE
EARLY EVE BEFORE DIMINISHING. BACK DOOR COLD FRONT WILL SWEEP
ACROSS CWA AFT MIDNIGHT USHERING COOLER AND DRIER AIR BACK INTO THE
REGION.
FRIDAY AND FRIDAY NIGHT - CONFIDENCE...MEDIUM
CONSIDERABLE DAVA TAKES HOLD WITH INCOMING MID LEVEL RIDGING IN
THE WAKE OF DEPARTED SHORTWAVE INTO THE OHIO VALLEY. LOW LEVEL
COLD ADVECTION WELL UNDERWAY IN THE WAKE OF THE THURSDAY NIGHT
COLD FRONT. LLVL RH PROGS AND MOS DATA SUGGEST SOME MORNING
CLOUDINESS HANGING ON BUT THINGS SCOUR OUT IN THE AFTERNOON. MAIN
CONCERN THEN SHIFTS TO FROST POTENTIAL FOR LATER FRIDAY NIGHT.
SURFACE HIGH RIDGES IN AND WINDS ARE PROGGD TO BECOME QUITE LIGHT.
925 TEMPS ARE SUPPORTIVE OF THE CHILLY 30S THAT MOS IS GENERATING
SO HAVE INTRODUCED FROST INTO THE GRIDS FOR LATER FRIDAY NIGHT.
WHERE TEMPS ARE COLDEST AT SOME OF THE INTERIOR SECTIONS OF THE
CWA HAVE WENT WITH AREAS OF FROST WITH PATCHY ELSEWHERE. MAY END
UP NEEDING AN ADVISORY BUT AT THIS TIME WILL MENTION IN HWO.
SATURDAY - CONFIDENCE...MEDIUM
SO AFTER A CHILLY START ANOTHER QUIET DAY IS IN STORE FOR SRN WI
WITH THE SURFACE RIDGE AXIS SHIFTING TO OUR EAST. THIS WILLS ET UP
A NICE RETURN AND 850/925 WAA. WARMUP WILL BE TEMPERED LAKESIDE AS
ONSHORE FLOW FROM THE SE WILL DOMINATE.
SATURDAY NIGHT THROUGH MONDAY NIGHT - CONFIDENCE...MEDIUM
AN UNSETTLED PATTERN IS EXPECTED WITH SURFACE WARM FRONT SETTING UP
ACROSS CNTRL OR SRN WI. LOW PRESSURE IN THE NRN PLAINS WILL BE
DRIVEN BY APPROACHING MID LEVEL WAVE AND INCREASING DCVA THERE. SO
SHRA/TSRA INITIALLY WILL BE DRIVEN BY THE LLJ INTERACTION WITH THE
SFC/850 FRONTS IN THE STATE. THE SURFACE LOW IS THEN EXPECTED TO
WORK EASTWARD ALONG THE SFC FRONT SUNDAY NIGHT INTO MONDAY WHICH
WILL SUPPORT MORE ROUNDS OF SHRA/TSRA. IN ADDITION THERE WILL BE
TIMES WHEN THE LEFT FRONT EXIT REGION OF THE UPPER JET WILL BE
SITUATED FAVORABLY ACROSS SRN WI FOR ENHANCED LIFT. THE GFS
CONTINUES TO BE THE FASTER SOLUTION EXITING THIS PRECIP EARLY MONDAY
EVENING WHILE THE ECMWF HANGS ONTO SOME PRECIP ALL OF MONDAY NIGHT.
TUESDAY - CONFIDENCE...LOW TO MEDIUM
DUE TO THE DIFFERING SPEEDS OF THIS SYSTEM THERE IS SOME TIMING
CONCERNS. THE GFS CONTINUES TO BE THE FASTEST SOLUTION WITH THE LOW
AND UPPER WAVE OFF TO OUR EAST WHILE THE ECMWF AND GEM SLOWER SPEED
SUGGESTS PRECIP COULD LINGER INTO TUESDAY MORNING. WILL GO WITH A
MORE PROGRESSIVE SOLUTION THAT THE GFS IS SHOWING AND THE SUPERBLEND
POPS TEND TO FAVOR THIS TREND. SO WILL GO DRY WITH A COOLER DAY AS
NORTHEAST WINDS AND SUBSIDENCE TAKE OVER DUE TO THE EXITING WAVE AND
LOW LEVEL CAA REGIME WITH INCOMING SFC HIGH.
WEDNESDAY - CONFIDENCE...MEDIUM
PATTERN REMAINS FAIRLY ACTIVE WITH ANOTHER 500 MILLIBAR WAVE RIDING
NORTHEAST INTO THE UPPER MIDWEST. A SURFACE LOW DEVELOPS FROM THE
DAKOTAS AND MINNESOTA WITH POTENTIAL FOR A STRONG SOUTHERLY WAA
REGIME AND 925 TEMPS POSSIBLY GETTING BACK INTO THE TEENS CELSIUS.
WILL GO WITH THE SUPERBLEND POPS FOR MORE SHRA/TSRA. WILL HAVE TO
KEEP AN EYE ON THIS ONE. SYSTEM HAS SOME PRETTY HIGH CWASP NUMBERS
..ATTM THESE HIGHEST NUMBERS ARE JUST TO OUR SOUTH. DECENT
DYNAMICS. LONG WAYS OFF BUT FOR THIS FAR OUT SOME GOOD CONSENSUS
BETWEEN THE ECMWF AND GFS. SUPERBLEND TEMPS MAY BE TOO COOL GIVEN
THE POTENTIAL WARM SIGNAL WITH THE 850/925 TEMPS.
AVIATION/12Z TAFS/...LIGHT ONSHORE FLOW WL CONTINUE TO PULL LAKE
INDUCED FOG INTO ERN TAF SITES INTO THE MORNING...AND MAY LINGER
AT KMKE THRU MUCH OF THE DAY. HOWEVER LOWEST VSBYS ARE EXPECTED
THIS MRNG. OTHERWISE IFR CIGS OVER TAF SITES SHOULD SLOWLY LIFT
THIS MRNG AND SHOULD TRANSITION TO VFR... HOWEVER CONFIDENCE LOW
IN EAST DUE TO LAKE BREEZE AND PERSISTENT ONSHORE FLOW. A BRIEF
T-STORM MAY AFFECT TAF SITES THIS AFTN OR EARLY EVE. BACK DOOR
COLD FRONT WILL RESULT IN ABRUPT WIND SHIFT AND GUSTY WINDS LATER
TNGT.
MARINE...MOIST LOW LEVEL AIR HAS SPREAD INTO THE SOUTHERN PORTION
OF THE NEARSHORE WATERS. KENOSHA WEBCAMS SHOW DENSE FOG AT THE SHORE
WHERE DEWPOINTS HAVE RISEN INTO THE LOWER 50S. DEWPOINTS REMAIN A
LITTLE LOWER FARTHER NORTH TOWARD SHEBOYGAN...HOWEVER WEBCAMS IN
THIS AREA ARE ALSO SHOWING LOWERING VSBYS. LAKE MI TEMPS REMAIN
MOSTLY IN THE LOWER 40S SO COOL WATER AND LIGHT WINDS ARE RESULTING
IN AREAS OF DENSE FOG. WINDS ARE EXPECTED TO REMAIN LIGHT SOUTH TO
SOUTHEAST TODAY AS WEAK LOW PRESSURE APPROACHES. HENCE EXPECT
AREAS OF DENSE FOG TO PERSIST AND WILL POST MARINE DENSE FOG ADVY
UNTIL 00Z FRI.
LOW PRESSURE WILL EXIT REGION OVERNIGHT. TIGHTENING PRESSURE
GRADIENT TO THE NORTH WILL PULL BACK DOOR COLD FRONT ACROSS NEAR
SHORE AREA FROM 05Z THROUGH 10Z TONIGHT. ABRUPT WIND SHIFT TO THE
NORTH TO NORTHEAST CAN BE EXPECTED WITH A RAPID INCREASE IN WIND
GUSTS. WIND GUSTS MAY APPROACH 30 KTS FOR SEVERAL HOURS. HENCE WL
POST SMALL CRAFT ADVISORY FOR LATE TONIGHT THROUGH FRIDAY DUE TO
LINGERING HIGH WAVES.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...DENSE FOG ADVISORY UNTIL 7 PM CDT THIS EVENING FOR LMZ643>646.
SMALL CRAFT ADVISORY FROM 2 AM TO 10 PM CDT FRIDAY FOR LMZ645-
646.
SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 7 PM CDT FRIDAY
FOR LMZ643-644.
&&
$$
UPDATE...DDV/SPM
TODAY/TONIGHT AND AVIATION/MARINE...MBK
FRIDAY THROUGH WEDNESDAY...COLLAR
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
619 AM CDT THU APR 21 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 408 AM CDT THU APR 21 2016
MAIN FCST CONCERNS THIS PERIOD...LINGERING -SHRA TODAY/THIS
EVENING...CLOUD TRENDS/TEMPERATURES TODAY/TONIGHT.
WV/IR IMAGERY AND SFC OBS AT 06Z SHOWED A SFC THRU MID LEVEL LOW
SPINNING OVER WESTERN IA...MAKING VERY LITTLE PROGRESS EASTWARD
SINCE 00Z. WV IMAGERY SHOWED MID LEVEL DRYING HAD SPREAD NORTHWARD
ACROSS MUCH OF WI/EASTERN MN ON THE EAST SIDE OF THE LOW...CLEARING
THE BULK OF THE -SHRA OUT OF THE FCST AREA. THIS DRYING WORKING
THE LOWER CLOUDS AS WELL...WITH FOG-PRODUCT IMAGERY INDICATING
CLEAR TO PARTLY CLOUDY SKIES OVER THE SOUTHWEST HALF OF THE FCST
AREA...WITH THIS DECREASE OF CLOUDS SPREADING NORTHEAST EARLY THIS
MORNING. SOME FOG DEVELOPING IN THE AREAS WHERE SKIES HAD
CLEARED...AIDED BY LIGHT WINDS AND THE RECENT /BUT LIGHT/ RAINS.
MODEL RUNS OF 21.00Z INITIALIZED QUITE WELL. MODEL CONSENSUS HAS
TRENDED THE SLOWER/STRONGER/FURTHER SOUTH OF THE EARLIER RUNS AS THE
OLD MID LEVEL LOW TRACKS ACROSS SOUTHERN IA TODAY THEN ACROSS IL
TONIGHT. NOT AS SLOW/SOUTH AS THE 20.00Z CAN-GEM THOUGH. RATHER
TIGHT MODEL CONSENSUS THRU 12Z FRI HAS SHORT-TERM FCST CONFIDENCE ON
THE GOOD SIDE THIS CYCLE.
IN THE SHORT TERM...MODEL CONSENSUS TRENDS LEAD TO SOME NEEDED
ADJUSTMENTS TO THE FCST...ESPECIALLY WITH CLOUD TRENDS AND TIMING OF
-SHRA CHANCES TODAY/THIS EVENING. STRONGER SHORTWAVE AROUND THE EAST
SIDE OF THE MID LEVEL LOW WAS LIFTING NORTH OF THE FCST AREA EARLY
THIS MORNING WITH DRY SLOT/DRYING IN THE 800-500MB LAYER SEEN IN WV
IMAGERY EAST OF THE MID LEVEL LOW ROTATING ACROSS THE AREA. NEARLY
VERTICALLY STACKED SFC-500MB LOW OVER NOW HAS A LESS PW TO WORK WITH
AND A DRIER COLUMN AHEAD OF IT TO OVERCOME AS IT T MOVES EAST TODAY.
MUCH LIKE WED...BIGGER CHALLENGE TODAY WILL BE CLOUD TRENDS AS THE
DRY SLOT PIVOTS ACROSS THE AREA. APPEARS MUCH OF THE FCST AREA WILL
NOW SEE A PERIOD OF SUNSHINE THIS MORNING AND TRENDED BOTH CLOUDS/
SHRA CHANCES DOWN THIS MORNING. WITH THE DRIER AIR AHEAD OF IT AND
FURTHER SOUTH TRACK OF THE 500MB LOW/SHORTWAVE WITH IT...APPEARS
BULK OF THE SHRA WITH THAT PORTION OF THE SYSTEM WILL PASS SOUTH OF
THE FCST AREA THIS AFTERNOON AND REDUCED THOSE PRECIP CHANCES AS
WELL. SLOWER EASTWARD PROGRESS OF THE ENTIRE TROUGH NOW PIVOTS THE
DEFORMATION -SHRA BAND WRAPPED AROUND THE NORTHWEST SIDE OF THE
CIRCULATION INTO THE FCST AREA LATE THIS AFTERNOON/THIS EVENING.
WITH THE 700-500MB LOW OPENING UP THIS EVENING AS IT MOVES EAST OF
THE REGION...DEFORMATION BAND LOOSES MUCH OF ITS FORCING/MOISTURE
FEED AND QUICKLY DIMINISHES AFTER 03Z AT IT TRIES TO CROSS THE
FCST AREA. RAISED -SHRA CHANCES A BIT IN THE 00-03Z PERIOD THEN
THE QUICKLY DIMINISHING TREND OF -SHRA AFTER 03Z LOOKS GOOD.
OTHER CONCERN TONIGHT IS CLOUD CLEARING TREND. MODELS CLEAR OUT
THE MOISTURE AROUND/ABOVE 850MB AS NORTHWEST FLOW AND DEEPER
LAYERED SUBSIDENCE SPREAD IN BEHIND THE DEPARTING TROUGH. STRONGER
PRESSURE RISES BUILD IN LATER TONIGHT TOO...BUT RATHER CONSISTENT
SIGNAL AMONG MODELS FOR 925MB MOISTURE TO ROTATE SOUTH INTO THE
AREA TONIGHT. SOUNDINGS SHOWING THIS MOISTURE STUCK IN/UNDER A
RATHER STRONG INVERSION IN THE 925-875MB LAYER. WITH CLOUDS
UPSTREAM OVER WESTERN ONTARIO IN THIS MOISTURE FIELD...TRENDED
TOWARD SLOWER DECREASE/CLEARING OF THE CLOUDS TONIGHT. WITH SOME
SUNSHINE EXPECTED MOST LOCATIONS THIS MORNING...LEANED TOWARD
WARMER OF THE GUIDANCE HIGHS. CLEARING NORTH TO SOUTH LATER
TONIGHT WILL SET THE FCST AREA UP FOR A LARGER TEMP GRADIENT BY
FRI MORNING. FAVORED WARMER OF GUIDANCE LOWS ACROSS THE SOUTH END
OF THE FCST AREA AND BLEND OF THE LOWS ACROSS THE NORTH END. NORTH
GRADIENT WINDS/BOUNDARY LAYER MIXING SHOULD KEEP ANY
FROST/FREEZING TEMPS AT BAY.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 408 AM CDT THU APR 21 2016
FOR FRIDAY THRU SATURDAY NIGHT...
MAIN FCST CONCERNS THIS PERIOD...COOL TEMPERATURES/PATCHY FROST
POSSIBILITIES FRI NIGHT...RETURNING -SHRA/ISOLATED TSRA CHANCES SAT
NIGHT.
21.00Z MODEL RUNS IN VERY GOOD AGREEMENT ON RISING HGTS/SHORTWAVE
RIDGING TO BUILD INTO THE UPPER MIDWEST FRI...WITH THIS RIDGING TO
THEN HOLD OVER THE REGION FRI NIGHT/SAT. MODELS CONTINUE TREND OF
WEAKENING THIS RIDGING OVER THE REGION SAT NIGHT...AHEAD OF THE NEXT
TROUGH/MID LEVEL LOW FROM THE WESTERN CONUS AS IT MOVE INTO THE
WY/CO/NEB/SD AREA. MUCH TIGHTER CONSENSUS ON THIS FEATURE THIS CYCLE
VS. THE 19.00Z/20.00Z RUNS. FCST CONFIDENCE IN THE FRI THRU SAT
NIGHT PERIOD IS GOOD THIS CYCLE.
WITH PROGRESSIVE FLOW AND RISING HGTS/SHORTWAVE RIDGING BUILDING IN
FRI...ANY REMAINING CLOUDS SHOULD EXIT RATHER QUICKLY FRI MORNING AS
THE SFC-850MB RIDGE AXIS AND ITS ANTI-CYCLONIC FLOW BUILDS
SOUTHEAST ACROSS THE REGION. 925MB TEMPS ONLY IN THE +7C TO +11C
RANGE AT 00Z SAT. EVEN WITH PLENTY OF SUNSHINE FRI...HIGHS FRI
LOOKING TO BE IN THE MID 50S-LOWER 60S MOST LOCATIONS. SFC RIDGE
AXIS IS STILL NEAR OVER THE FCST AREA FRI EVENING...WITH WINDS
EXPECTED TO DECOUPLE FOR A WHILE MOST LOCATIONS. GRADIENT REMAINS
QUITE WEAK OVER THE EAST SIDE OF THE FCST AREA THRU 12Z SAT...FOR
LIGHT/VARIABLE WINDS AND STRONGER RADIATIONAL COOLING. COOLER
AIRMASS...925MB TEMPS +3C TO +6C...REMAINS OVER THE EAST HALF OF
THE FCST AREA FRI NIGHT WHILE WARM ADVECTION AND SOME SOUTHEAST
GRADIENT WINDS SPREAD OVER THE WEST HALF OF THE FCST AREA. TEMPS
ACROSS THE EAST SIDE OF THE FCST AREA LOOKING TO DROP INTO THE MID
30S LATE FRI NIGHT AND ADDED PATCHY/AREAS OF FROST TO THE GRIDS IN
THE USUAL COLDER LOW-LAYING LOCATIONS IN THE 06Z-14Z SAT PERIOD.
MAY YET NEED A FROST ADVISORY FOR JACKSON/MONROE/ADAMS/JUNEAU
COUNTIES LATE FRI NIGHT INTO EARLY SAT MORNING. SOUTHERLY
FLOW/WARM ADVECTION SPREAD ACROSS THE AREA SAT AS LOW PRESSURE/MID
LEVEL TROUGHING START TO MOVE INTO THE PLAINS. 925MB TEMPS BY SAT
AFTERNOON SUPPORTING HIGHS IN THE 60S TO NEAR 70...FOR WHAT SHOULD
BE A RATHER NICE WEATHER DAY ON THE FRONT HALF OF THE WEEKEND.
FIRST MOISTURE AHEAD OF THE PLAINS SYSTEM ARRIVES SAT NIGHT...WITH
THE NOSE OF THE LOW LEVEL JET/MOISTURE TRANSPORT BEING LIFTED OVER A
FRONTAL BOUNDARY PROGGED TO SAG SLOWLY SOUTH THRU THE REGION. RATHER
TIGHT MODEL CONSENSUS FOR THIS BOUNDARY TO LIE ACROSS SOUTHERN MN TO
NEAR KGRB AT 12Z SUN. PW VALUES INCREASE INTO THE 1+ INCH RANGE BY
12Z SUN. MODELS RATHER CONSISTENT IN DEVELOPING PRECIP NEAR/NORTH OF
THE FRONTAL BOUNDARY...ESPECIALLY LATER SAT NIGHT. CARRIED 20-50
PERCENT SHRA CHANCES SAT EVENING...MAINLY OVER THE NORTHEAST 1/2 OF
THE FCST AREA...RAISING TO 40-60 PERCENT AFTER MIDNIGHT. LESSER
CHANCES ACROSS THE SOUTH PORTIONS OF THE FCST AREA SAT NIGHT...
SOUTH OF THE FRONT. SMALL TSRA CHANCE WEST OF THE MS RIVER LATER SAT
NIGHT REASONABLE AS IMPROVING MODEL SIGNAL FOR MUCAPE TO INCREASE
INTO THE 250-500 J/KG RANGE AS THE COLUMN BECOMES INCREASINGLY MOIST.
FAVORED WARMER OF GUIDANCE HIGHS FRI...COOLER OF GUIDANCE LOWS FRI
NIGHT THEN A BLEND OF THE GUIDANCE HIGHS/LOWS FOR SAT/SAT NIGHT.
FOR SUNDAY THRU WEDNESDAY...DAYS 4 TO 7...
MAIN FCST CONCERNS THIS PERIOD...SHRA/TSRA CHANCES MUCH OF THE
PERIOD.
MEDIUM RANGE MODEL RUNS OF 21.00Z OFFER A TIGHTENING CONSENSUS FOR
THE CO/WY/NEB/SD LOW/TROUGH TO MOVE SLOWLY EAST SUN ACROSS THE
PLAINS SUN/SUN NIGHT...THEN ACROSS THE UPPER MIDWEST MON/MON NIGHT.
IMPROVING SIGNAL FOR SHORTWAVE RIDGING TO BUILD ACROSS THE UPPER
MIDWEST TUE...WITH THE NEXT STRONGER TROUGH/ENERGY APPROACHING/
MOVING INTO THE UPPER MIDWEST WED. WITH BETTER MODEL AGREEMENT ALL
THE WAY THRU WED...FCST CONFIDENCE IN THE DAY 4-7 PERIOD IS AVERAGE
THIS CYCLE.
TIGHTER MODEL CONSENSUS CONTINUES TO SAG THE FRONTAL BOUNDARY SLOWLY
SOUTH ACROSS THE FCST AREA SUN/SUN NIGHT...THIS AS THE SFC LOW MOVE
EAST/SOUTHEAST ALONG IT. SOME MODEL DETAIL DIFFERENCES ON THE SPEED
OF THE LOW MOVING EAST...BUT BIGGER PICTURE IS BROAD FORCING/ASCENT
ACROSS THE AREA THESE PERIODS AHEAD OF THE APPROACHING SFC-500MB
LOW. CONSENSUS SHRA CHANCES IN TOE 40-70 PERCENT RANGE SUN/SUN NIGHT
LOOKING GOOD FOR NOW...WITH POTENTIAL FOR SOME 1 TO 2 INCH RAINFALL
TOTALS FROM 12Z SUN TO 12Z MON. MUCAPE SUN/SUN NIGHT GENERALLY
PROGGED TO BE IN THE 250-500 J/KG RANGE. THIS ALONG WITH THE BROAD
FORCING/ASCENT...ACCOUNTS FOR THE ISOLATED-SCT TSRA MENTION ACROSS
MOST OF THE FCST AREA THESE PERIODS. MAIN TROUGH PROGGED TO WEAKEN
AS IT PASSES MON/MON NIGHT WITH THE FRONT BEING PUSHED FURTHER SOUTH
OF THE FCST AREA. DECREASING MAINLY SHRA CHANCES MON/MON NIGHT
LOOKING WELL TRENDED...AS DO COOLER TEMPS AS NORTH/NORTHEAST FLOW
AND LOW LEVEL COLD ADVECTION SPREADS ACROSS THE AREA. TUE TRENDING
TO BE THE DRY DAY AS THE MID LEVEL SHORTWAVE RIDGING AND SFC HIGH
PRESSURE BUILD ACROSS THE REGION. THE DRYNESS NEXT WEEK APPEARS
SHORT LIVED AS THE NEXT SFC-MID LEVEL LOW WITH ITS ROUND OF MOISTURE
INCREASE...LOWER LEVEL THERMO-DYNAMIC FORCING AND DIVERGENCE ALOFT
APPROACHES/SPREADS INTO THE REGION TUE NIGHT/WED. SHRA/TSRA CHANCES
INCREASING INTO THE 30-50 PERCENT RANGE BY WED REASONABLE AT THIS
TIME. GIVEN SOME MODEL DETAIL VARIABILITY FOR SUN-WED...MODEL/
ENSEMBLE CONSENSUS OF HIGHS/LOWS THRU THIS PERIOD LOOKING WELL
TRENDED AT THIS TIME.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 619 AM CDT THU APR 21 2016
THE DENSE FOG THAT FORMED OVERNIGHT IS ALREADY STARTING TO
DISSIPATE AS A MID LEVEL CLOUD DECK MOVES IN FROM THE SOUTH.
EXPECTING THAT THIS WILL BE PRETTY MUCH GONE AT BOTH SITES BY
14Z...BUT KRST WILL START OUT MUCH LOWER THAN KLSE AS THE CLOUDS
HAVE YET TO MOVE IN. AS THE SURFACE LOW OVER WESTERN IOWA MOVES
EAST TODAY...EXPECT TO SEE THE BAND OF LOWER CLOUDS OVER SOUTHWEST
AND CENTRAL MINNESOTA MOVE INTO THE AREA. BOTH THE 21.06Z AND
21.09Z RAP WOULD SUGGEST THESE WILL COME IN AS A LOW VFR DECK.
THERE COULD BE SOME SHOWERS WITH THESE CLOUDS AS WELL...BUT
THE HI-RES MODELS SUGGEST ANY SHOWERS WOULD BE VERY LATE THIS
AFTERNOON. CONFIDENCE THAT THE FORCING WILL BE STRONG ENOUGH TO
STILL BE PRODUCING SHOWERS IS NOT VERY HIGH SO WILL LET LATER
FORECAST ADD A VCSH IF NEEDED. AS THE WINDS COME AROUND TO THE
NORTHWEST THE LOWER CLOUDS OVER NORTHWEST MINNESOTA AND SOUTHWEST
ONTARIO SHOULD COME DOWN OVERNIGHT TO PRODUCE A MVFR CEILING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RRS
LONG TERM....RRS
AVIATION...04
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
337 AM CDT THU APR 21 2016
.TODAY AND TONIGHT...FORECAST CONFIDENCE - LOW TO MEDIUM.
FORECAST CONCERNS FOCUS ON PRECIP THREAT RETURNING TODAY AND FOG.
DRIER AIR WRAPPING AROUND UPSTREAM LOW PRESSURE ERODING LOW CLOUDS
OVER FAR SOUTHWEST WI AND WILL AFFECT SOUTHWEST CWA NEXT SEVERAL
HOURS. THIS WILL ALLOW FOG TO DEVELOP AND FOG COULD EASILY TURN
DENSE FOR SEVERAL HOURS. WITH EARLIER SUNRISE...WL HOLD OFF ON
ISSUING DENSE FOG ADVY FOR KEFT/KMRJ AREAS AND GO WITH SPS FOR
NOW...HOWEVER MAY NEED TO GO WITH ADVY SHOULD VSBYS RAPIDLY FALL
IN NEXT 1-2 HOURS. FOG SHOULD LIFT AFTER 13Z.
FARTHER EAST...EXPCT SCT -SHRA TO GRADUALLY DIMINISH THRU THE EARLY
MORNING AS LOW LEVEL MOISTURE ADVECTION WEAKENS. HRRR HAS BEEN
SHOWING SCT -SHRA REFORMING OVER CENTRAL AND EASTERN CWA EARLY THIS
MORNING BUT OTHER SHORT TERM GUIDANCE DRIER AND SUCCUMBING TO DRYING
MID-LEVEL AIR FROM THE SOUTHWEST. DIFFICULT TO FIND FORCING
MECHANISM FOR THESE -SHRA DEPICTED BY HRRR...SO WL GO WITH MAINLY
DRY CONDITIONS THIS MRNG ACROSS CENTRAL CWA AND KEEP SMALL CHANCE
FOR LINGERING -SHRA IN EAST FOR A FEW HOURS.
EXPECT LOW CLOUDS TO THIN ACROSS CENTRAL AND MOST OF EASTERN CWA
LATER THIS MRNG BUT MORE CLOUDS AND FOG MAY LINGER CLOSER TO THE
LAKE DUE TO LAKE BREEZE.
DESPITE WEAK SHEAR...DEWPOINTS IN THE 50S AND PARTIAL SUNSHINE
SHOULD RESULT IN MUCAPES INCREASING TO 300 TO 800 J THIS AFTN.
STRONGEST FORCING ASSOCIATED WITH UPPER LOW TO REMAIN TO THE SOUTH
OF THE IL BORDER THIS AFTN...HOWEVER WL STILL HAVE LOW PRESSURE TROF
MOVING THRU SRN WI. IN ADDITION...SRN CWA GETS GRAZED BY STRONGER
SYNOPTIC FORCING FROM LEFT EXIT REGION OF UPPER JET. HENCE EXPECT
SCT SHRA AND A FEW TSTRMS TO DEVELOP OVER CWA THIS AFTN INTO THE
EARLY EVE BEFORE DIMINISHING. BACK DOOR COLD FRONT WILL SWEEP
ACROSS CWA AFT MIDNIGHT USHERING COOLER AND DRIER AIR BACK INTO THE
REGION.
.FRIDAY AND FRIDAY NIGHT - CONFIDENCE...MEDIUM
CONSIDERABLE DAVA TAKES HOLD WITH INCOMING MID LEVEL RIDGING IN
THE WAKE OF DEPARTED SHORTWAVE INTO THE OHIO VALLEY. LOW LEVEL
COLD ADVECTION WELL UNDERWAY IN THE WAKE OF THE THURSDAY NIGHT
COLD FRONT. LLVL RH PROGS AND MOS DATA SUGGEST SOME MORNING
CLOUDINESS HANGING ON BUT THINGS SCOUR OUT IN THE AFTERNOON. MAIN
CONCERN THEN SHIFTS TO FROST POTENTIAL FOR LATER FRIDAY NIGHT.
SURFACE HIGH RIDGES IN AND WINDS ARE PROGGD TO BECOME QUITE LIGHT.
925 TEMPS ARE SUPPORTIVE OF THE CHILLY 30S THAT MOS IS GENERATING
SO HAVE INTRODUCED FROST INTO THE GRIDS FOR LATER FRIDAY NIGHT.
WHERE TEMPS ARE COLDEST AT SOME OF THE INTERIOR SECTIONS OF THE
CWA HAVE WENT WITH AREAS OF FROST WITH PATCHY ELSEWHERE. MAY END
UP NEEDING AN ADVISORY BUT AT THIS TIME WILL MENTION IN HWO.
.SATURDAY - CONFIDENCE...MEDIUM
SO AFTER A CHILLY START ANOTHER QUIET DAY IS IN STORE FOR SRN WI
WITH THE SURFACE RIDGE AXIS SHIFTING TO OUR EAST. THIS WILLS ET UP
A NICE RETURN AND 850/925 WAA. WARMUP WILL BE TEMPERED LAKESIDE AS
ONSHORE FLOW FROM THE SE WILL DOMINATE.
.SATURDAY NIGHT THROUGH MONDAY NIGHT - CONFIDENCE...MEDIUM
AN UNSETTLED PATTERN IS EXPECTED WITH SURFACE WARM FRONT SETTING UP
ACROSS CNTRL OR SRN WI. LOW PRESSURE IN THE NRN PLAINS WILL BE
DRIVEN BY APPROACHING MID LEVEL WAVE AND INCREASING DCVA THERE. SO
SHRA/TSRA INITIALLY WILL BE DRIVEN BY THE LLJ INTERACTION WITH THE
SFC/850 FRONTS IN THE STATE. THE SURFACE LOW IS THEN EXPECTED TO
WORK EASTWARD ALONG THE SFC FRONT SUNDAY NIGHT INTO MONDAY WHICH
WILL SUPPORT MORE ROUNDS OF SHRA/TSRA. IN ADDITION THERE WILL BE
TIMES WHEN THE LEFT FRONT EXIT REGION OF THE UPPER JET WILL BE
SITUATED FAVORABLY ACROSS SRN WI FOR ENHANCED LIFT. THE GFS
CONTINUES TO BE THE FASTER SOLUTION EXITING THIS PRECIP EARLY MONDAY
EVENING WHILE THE ECMWF HANGS ONTO SOME PRECIP ALL OF MONDAY NIGHT.
.TUESDAY - CONFIDENCE...LOW TO MEDIUM
DUE TO THE DIFFERING SPEEDS OF THIS SYSTEM THERE IS SOME TIMING
CONCERNS. THE GFS CONTINUES TO BE THE FASTEST SOLUTION WITH THE LOW
AND UPPER WAVE OFF TO OUR EAST WHILE THE ECMWF AND GEM SLOWER SPEED
SUGGESTS PRECIP COULD LINGER INTO TUESDAY MORNING. WILL GO WITH A
MORE PROGRESSIVE SOLUTION THAT THE GFS IS SHOWING AND THE SUPERBLEND
POPS TEND TO FAVOR THIS TREND. SO WILL GO DRY WITH A COOLER DAY AS
NORTHEAST WINDS AND SUBSIDENCE TAKE OVER DUE TO THE EXITING WAVE AND
LOW LEVEL CAA REGIME WITH INCOMING SFC HIGH.
.WEDNESDAY - CONFIDENCE...MEDIUM
PATTERN REMAINS FAIRLY ACTIVE WITH ANOTHER 500 MILLIBAR WAVE RIDING
NORTHEAST INTO THE UPPER MIDWEST. A SURFACE LOW DEVELOPS FROM THE
DAKOTAS AND MINNESOTA WITH POTENTIAL FOR A STRONG SOUTHERLY WAA
REGIME AND 925 TEMPS POSSIBLY GETTING BACK INTO THE TEENS CELSIUS.
WILL GO WITH THE SUPERBLEND POPS FOR MORE SHRA/TSRA. WILL HAVE TO
KEEP AN EYE ON THIS ONE. SYSTEM HAS SOME PRETTY HIGH CWASP NUMBERS
...ATTM THESE HIGHEST NUMBERS ARE JUST TO OUR SOUTH. DECENT
DYNAMICS. LONG WAYS OFF BUT FOR THIS FAR OUT SOME GOOD CONSENSUS
BETWEEN THE ECMWF AND GFS. SUPERBLEND TEMPS MAY BE TOO COOL GIVEN
THE POTENTIAL WARM SIGNAL WITH THE 850/925 TEMPS.
&&
.AVIATION/12Z TAFS/...LIGHT ONSHORE FLOW WL CONTINUE TO PULL LAKE
INDUCED FOG INTO ERN TAF SITES INTO THE MORNING...AND MAY LINGER
AT KMKE THRU MUCH OF THE DAY. HOWEVER LOWEST VSBYS ARE EXPECTED
THIS MRNG. OTHERWISE IFR CIGS OVER TAF SITES SHOULD SLOWLY LIFT
THIS MRNG AND SHOULD TRANSITION TO VFR... HOWEVER CONFIDENCE LOW
IN EAST DUE TO LAKE BREEZE AND PERSISTENT ONSHORE FLOW. A BRIEF
T-STORM MAY AFFECT TAF SITES THIS AFTN OR EARLY EVE. BACK DOOR
COLD FRONT WILL RESULT IN ABRUPT WIND SHIFT AND GUSTY WINDS LATER
TNGT.
&&
.MARINE...MOIST LOW LEVEL AIR HAS SPREAD INTO THE SOUTHERN PORTION
OF THE NEARSHORE WATERS. KENOSHA WEBCAMS SHOW DENSE FOG AT THE SHORE
WHERE DEWPOINTS HAVE RISEN INTO THE LOWER 50S. DEWPOINTS REMAIN A
LITTLE LOWER FARTHER NORTH TOWARD SHEBOYGAN...HOWEVER WEBCAMS IN
THIS AREA ARE ALSO SHOWING LOWERING VSBYS. LAKE MI TEMPS REMAIN
MOSTLY IN THE LOWER 40S SO COOL WATER AND LIGHT WINDS ARE RESULTING
IN AREAS OF DENSE FOG. WINDS ARE EXPECTED TO REMAIN LIGHT SOUTH TO
SOUTHEAST TODAY AS WEAK LOW PRESSURE APPROACHES. HENCE EXPECT
AREAS OF DENSE FOG TO PERSIST AND WILL POST MARINE DENSE FOG ADVY
UNTIL 00Z FRI.
LOW PRESSURE WILL EXIT REGION OVERNIGHT. TIGHTENING PRESSURE
GRADIENT TO THE NORTH WILL PULL BACK DOOR COLD FRONT ACROSS NEAR
SHORE AREA FROM 05Z THROUGH 10Z TONIGHT. ABRUPT WIND SHIFT TO THE
NORTH TO NORTHEAST CAN BE EXPECTED WITH A RAPID INCREASE IN WIND
GUSTS. WIND GUSTS MAY APPROACH 30 KTS FOR SEVERAL HOURS. HENCE WL
POST SMALL CRAFT ADVISORY FOR LATE TONIGHT THROUGH FRIDAY DUE TO
LINGERING HIGH WAVES.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...DENSE FOG ADVISORY UNTIL 7 PM CDT THIS EVENING FOR LMZ643>646.
SMALL CRAFT ADVISORY FROM 2 AM TO 10 PM CDT FRIDAY FOR LMZ645-
646.
SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 7 PM CDT FRIDAY
FOR LMZ643-644.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...MBK
FRIDAY THROUGH WEDNESDAY...COLLAR
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
225 AM MST SAT APR 23 2016
.SYNOPSIS...
TEMPERATURES WILL BE ON A DOWNHILL TREND THIS WEEKEND AS THE FIRST OF
THREE LOW PRESSURE SYSTEMS MOVES THROUGH THE REGION TODAY. HIGHS
WILL DROP INTO THE 80S...POSSIBLY EVEN INTO THE 70S THROUGH NEXT
WEEK. THE SECOND SYSTEM WILL AFFECT THE REGION LATE MONDAY INTO
TUESDAY BRINGING BREEZY TO WINDY CONDITIONS BUT WITH LITTLE CHANCE
FOR ANY RAINFALL. ANOTHER STORM SYSTEM IS LIKELY FOR LATE NEXT WEEK
WITH AT LEAST SOME CHANCE OF RAIN POSSIBLE.
&&
.DISCUSSION...
AFTER SEVERAL DAYS OF VERY WARM TEMPERATURES...SOME RELIEF IS IN
SIGHT AS A COUPLE MAINLY DRY WEATHER SYSTEMS WILL BRING IN COOLER AIR
THROUGH EARLY NEXT WEEK. THE FIRST ONE IS CURRENTLY SITUATED OVER THE
GREAT BASIN AND WILL TRACK THROUGH UTAH TODAY...THUS STAYING WELL
NORTH OF OUR AREA. EVEN WITH THE NORTHERN TRACK OF THIS
SYSTEM...HEIGHTS ALOFT WILL LOWER ALONG WITH MODEST COOLING ALSO
TAKING PLACE. BREEZY WESTERLY WINDS ARE AGAIN EXPECTED TODAY UNDER AN
INCREASED PRESSURE GRADIENT...BUT GUSTS SHOULD REMAIN BELOW 25 MPH.
THE COOLING ALOFT...ROUGHLY 5C OF COOLING AT 850MB...WILL RESULT IN
HIGHS TODAY AND SUNDAY FALLING TO NEAR SEASONAL NORMALS.
WE WILL BE IN BETWEEN SYSTEMS ON SUNDAY WITH FAIRLY ZONAL FLOW
AFFECTING THE DESERT SOUTHWEST. THE SECOND LOW PRESSURE TROUGH WILL
BEGIN TO DROP OUT OF THE PACIFIC NORTHWEST AT THIS TIME WITH SOME
DEEPENING OCCURRING AS IT MOVES INTO THE GREAT BASIN ON MONDAY. THIS
SYSTEM WILL BE BETTER SUPPORTED ALOFT COMPARED TO THE FIRST ONE
CURRENTLY MOVING PAST TO OUR NORTH AND THUS WILL DEEPEN FURTHER AS IT
APPROACHES THE DESERT SOUTHWEST. MODEL ENSEMBLES SHOW VERY LITTLE
DIFFERENCES...SO CONFIDENCE IS HIGH THAT THIS STORM TRACK WILL BE
FURTHER SOUTH...LIKELY MOVING ACROSS NORTHERN ARIZONA EARLY TUESDAY.
DESPITE THE STRONGER DYNAMICS AND A MORE SOUTHERLY TRACK...THE LACK
OF ANY DECENT MOISTURE TO WORK WITH WILL KEEP RAIN CHANCES CONFINED
TO THE NORTHERN HALF OF ARIZONA. FOR OUR AREA THE BIGGEST IMPACT WILL
BE THE LIKELIHOOD OF STRONG WINDS MOVING IN LATER MONDAY. A WIND
ADVISORY WILL LIKELY BE NEEDED FOR SOUTHEAST CALIFORNIA AND MAYBE
PORTIONS OF SOUTHWEST ARIZONA FOR MONDAY AFTERNOON AND EVENING. THE
STRONG WINDS WILL SURELY GIVE RISE TO PATCHY AREAS OF BLOWING DUST
POSING SOME LOCALIZED VISIBILITY ISSUES.
EVEN MORE COOLER AIR IS EXPECTED TO MOVE IN ON TUESDAY AND WEDNESDAY
AS HIGHS SHOULD DROP TO BELOW NORMAL LEVELS. THESE COOLER CONDITIONS
WILL LIKELY CONTINUE THROUGH THE REST OF NEXT WEEK AS ANOTHER
POTENTIAL UPPER LOW IS ADVERTISED FOR THURSDAY AND FRIDAY. FOR NOW
THIS SYSTEM SHOWS A HIGHER LIKELIHOOD OF PRODUCING SOME RAIN ACROSS
SOUTHERN CALIFORNIA AND ARIZONA AS IT SHOULD HAVE MORE RESIDENCE TIME
OFF THE COAST OF CALIFORNIA AND THUS ADVECT BETTER MOISTURE INTO OUR
REGION. HAVE INCLUDED MAINLY SLIGHT CHANCE POPS IN THE FORECAST FOR
THIS TIME PERIOD AND WILL MONITOR CLOSELY FOR ANY NEEDED ADJUSTMENTS
TO POPS. THE CONTINUED BELOW NORMAL TEMPERATURES SEEMS VERY LIKELY
THROUGH THE END OF NEXT WEEK AS RELATIVELY LOW HEIGHTS ALOFT PERSIST
UNDER THIS UNSETTLED WEATHER REGIME.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA AND KSDL...AND
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
OCCASIONAL STRONG WIND GUSTS WILL BE THE MAIN AVIATION CONCERN
THROUGH SATURDAY AFTERNOON. A FEW W/SW GUSTS 20-25KT THROUGH THE
PHOENIX METRO AND 25-30KT OVER SERN CALIFORNIA WILL BE COMMON IN THE
EVENING BEFORE BETTER DECOUPLING OCCURS. THE WESTERLY COMPONENT
SHOULD HOLD MUCH LONGER INTO THE OVERNIGHT FOR THE PHOENIX TERMINALS
THAN IS TYPICAL. OCCASIONAL GUSTS WILL BE POSSIBLE AGAIN SATURDAY
AFTERNOON...THOUGH SPEEDS WEAKER THAN TODAY.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
A SERIES OF LOW PRESSURE SYSTEMS WILL MOVE NORTH OF THE REGION
THROUGH LATE NEXT WEEK...WHICH WILL KEEP TEMPERATURES GENERALLY AT
OR BELOW NORMAL. SEASONABLY BREEZY CONDITIONS ARE EXPECTED EACH
AFTERNOON AS WELL. WINDS WILL BE SOMEWHAT STRONGER MONDAY AHEAD OF
THE SECOND LOW PRESSURE SYSTEM...THOUGH CRITICAL FIRE WEATHER
CONDITIONS ARE NOT ANTICIPATED. A MORE DISCERNIBLE INCREASE IN
MOISTURE IS EXPECTED AHEAD OF A STORM SYSTEM THURSDAY...WHICH WILL
BRING A SLIGHT CHANCE OF PRECIPITATION THROUGH FRIDAY.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT EXPECTED.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...KUHLMAN
AVIATION...MO
FIRE WEATHER...HIRSCH
Area Forecast Discussion...UPDATED
National Weather Service Reno NV
1022 PM PDT FRI APR 22 2016
.UPDATE...
Latest radar trends show a rapid decrease in both intensity and
coverage of snow showers as instability/convection decrease across
the interior valleys of northern CA. The upper level shortwave
will exit late tonight with drier and more stable airmass to bring
an end to showers Saturday. Temperatures will remain below
freezing overnight where snow fell today. Therefore roads will see
little improvement until treated. The snow advisory will expire at
11 pm. However, anyone planning travel during the overnight hours
should check the latest road conditions.
&&
.SYNOPSIS...
A break in the wet weather is expected Saturday before more
showers arrive Sunday into Monday. Unsettled weather will continue
through next week with below average temperatures.
&&
.PREVIOUS DISCUSSION... /Issued 736 PM PDT FRI APR 22 2016/
UPDATE...
The cold front has moved completely through western NV as of early
this evening and gradients have relaxed enough to go ahead and
drop the wind advisories and areas of blowing dust. Winds will
still be locally gusty before subsiding further this evening, but
well below earlier peaks.
Convection continues to fire over the Sacramento Valley and then
move eastward into the Tahoe Basin. Moderate to heavy snow was
falling under some of the stronger showers with roads likely to
remain a mess this evening, especially with the sun setting.
Expect another 1 to 3 inches, locally up to 4 inches this evening
before showers begin to diminish. We will continue the snow
advisory through expiration. Scattered snow showers may also
produce periods of slick roads along Hwy 395 through Mono County.
Make sure to check road conditions if you must travel tonight.
Hohmann
SYNOPSIS...
Moderate to occasionally heavy bands of snow showers will continue
across the Tahoe Basin through this evening with showers more
scattered elsewhere tonight. A break is expected Saturday before
more showers arrive Sunday into Monday. Unsettled weather will
continue through next week with below average temperatures.
PREVIOUS DISCUSSION... /Issued 303 PM PDT FRI APR 22 2016/
SYNOPSIS...
A strong Pacific storm will continue to move through the Sierra
and Western Nevada tonight. Rain and heavy mountain snow are
expected this evening near and south of I-80. A break is expected
Saturday before more showers are expected Sunday into Monday with
another system. Unsettled weather will continue through next week
with below average temperatures.
SHORT TERM...
A strong spring storm continues to move through. Heavy snow is
falling in the Sierra with rates approaching 3"/hr. It is best to
avoid travel in the Sierra for the next few hours if possible.
Heavy convective snowfall continues in the Sierra with the bands
extending from Westwood south into Bridgeport. Heavy snow is
falling above 6000 feet, with the snow level locally down to 4500
feet in the heaviest bands. Latest satellite/radar trends support
the HRRR in keeping the heaviest rain/snow going thru 03Z near and
south of I-80. After there will be a rapid reduction in showers as
the upper forcing moves east and the airmass stabilizes.
Until then, another 6+ inches of snow is possible above 7000 feet
with another 2-4" down to 5500-6000 feet. Rainfall into Western NV
will be heaviest in the Sierra front where an additional 1/4" of
rain is possible. It may mix with snow at times in the foothills
while lighter amounts are expected toward the highway 95 corridor.
Winds are much weaker along the Sierra Front with the precip
falling, but strong gusts continue east of a Bridgeport to
Lovelock line. Will cancel the advisory for Reno-Carson-Minden,
but leave the remainder as the winds continue there.
Behind this storm, a break is expected Saturday with continued
cool temps, but lighter winds and dry conditions. Another upper
low is expected Sunday afternoon into Monday. Showers are expected
Sunday afternoon with enough instability for a few thunderstorms
as well. The core of the low will move overhead Monday morning
with much colder air. Snow levels will fall to near the valley
floors. While this storm will have some moisture with it, the best
forcing is expected to remain over Eastern NV so we are not
expecting another big precip event. However, there remains a
threat (low at this time) of some light snowfall during the Monday
morning commute along the I-80 and highway 50 corridors. Wallmann
LONG TERM...Monday Night through Friday...
Unsettled weather pattern is expected to continue through next
week as late season storm systems line up to move into the West
Coast. Wednesday-Friday could be a rather wet period for much of
the region with potential for additional snow in higher
elevations.
For Monday night, the first upper low is likely to be on its way
out with lingering rain and snow showers diminishing. Tuesday
still looks like the least active weather day, although a few
showers remain possible as residual moisture will remain in place.
Even though temperatures are expected to increase about 10-15
degrees from Monday, highs in the lower 60s and around 50 degrees
near the Sierra will still be a few degrees below average for late
April.
For next Wednesday-Friday, medium range guidance continues to
indicate a potent low pressure tracking southward along the
California coast, then swing inland across the southwest US (or
possibly farther north into eastern NV). Despite this southerly
track, a broad area of upper divergence and instability is
projected to set up over the Sierra and western NV, along with a
decent tap of Pacific moisture. A few thunderstorms are also
possible each afternoon, although the better instability looks to
be trending north of I-80 by next Friday. Current projections
favor the best overall rain and snow chances Wednesday night and
higher thunderstorm potential on Thursday, but this could vary
depending on the eventual storm track. Widespread cloud cover will
keep daytime temps a few degrees below average each day, with
nighttime temps slightly above average. Early snow level
projections generally range from 6000-7000 feet in the Sierra,
although these snow levels could occasionally drop several hundred
feet during convection or heavier precip bands. MJD
AVIATION...
The most significant weather effects on aviation will continue
through this evening with IFR/LIFR cigs/vsby in snow near the
Sierra including KTVL/KTRK/KMMH, and a few inches of snow
accumulating on pavement. For lower elevations including KRNO-
KCXP, rain will produce MVFR cigs/vsby with mountain obscurations,
IFR at times during heavier rain bands. The strongest winds have
ended at KRNO-KCXP but some gusts to 35 KT remain possible. KMMH
may receive stronger gusts above 40 KT until 03z.
Later tonight, if cloud cover breaks up sufficiently, areas of
FZFG would develop across many Sierra valleys around Tahoe and
northeast CA, including KTRK. For Saturday, generally VFR
conditions are expected with lighter winds. MJD
&&
.REV Watches/Warnings/Advisories...
NV...None.
CA...None.
&&
$$
For more information from the National Weather Service visit...
http://weather.gov/reno
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
945 PM PDT FRI APR 22 2016
.SYNOPSIS....A FEW SHOWERS WILL LINGER INTO THE EVENING HOURS AND
END BY MIDNIGHT. DRY WEATHER IS EXPECTED ALONG WITH SEASONABLY
COOL TEMPERATURES THROUGH THIS WEEKEND AND INTO EARLY NEXT WEEK.
LOCALLY STRONG AND GUSTY NORTHWEST WINDS MAY OCCUR FROM LATE
SUNDAY INTO MONDAY...MAINLY NEAR THE COAST AND IN THE HILLS. THE
NEXT CHANCE OF RAIN WILL BE AROUND THE MIDDLE OF NEXT WEEK.
&&
.DISCUSSION...AS OF 9:00 PM PDT FRIDAY...POST-FRONTAL SHOWER
ACTIVITY HAS BEEN GRADUALLY TAPERING OFF SINCE EARLY EVENING.
RADAR CURRENTLY SHOWS ISOLATED LIGHT SHOWERS FROM THE CENTRAL SF
BAY AREA SOUTH TO MONTEREY COUNTY. BASED ON LATEST HRRR AND NAM
MODELS WE CAN EXPECT ALL SHOWER ACTIVITY TO END BY MIDNIGHT.
DRY WEATHER IS FORECAST OVER THE WEEKEND ALONG WITH SLIGHTLY
COOLER THAN NORMAL TEMPERATURES. AN "INSIDE SLIDER" IS FORECAST TO
DROP ACROSS NORTHEAST CALIFORNIA LATE SUNDAY AND SUNDAY NIGHT. ALL
PRECIP WITH THIS SYSTEM IS FORECAST TO REMAIN TO OUR NORTH AND
EAST. THE PRIMARY IMPACT THIS SYSTEM WILL HAVE ON OUR WEATHER WILL
BE TO GENERATE SOME LOCALLY STRONG AND GUSTY NORTHWEST WINDS FROM
LATE SUNDAY INTO MONDAY. STRONGEST WINDS BE ALONG THE COAST AND IN
THE HILLS. WINDS MAY GUST LOCALLY TO 40 MPH AND THIS MAY BE A
MARGINAL WIND ADVISORY SCENARIO. WINDS SHOULD EASE IN ALL AREAS BY
MONDAY NIGHT.
OUR NEXT POTENTIAL FOR RAINFALL WILL BE AROUND THE MIDDLE OF NEXT
WEEK WHEN A SYSTEM IS DUE TO DROP IN FROM THE NORTHWEST. THE 18Z
GFS FORECASTS WIDESPREAD SHOWER ACTIVITY WITH THIS SYSTEM FROM
WEDNESDAY AFTERNOON THROUGH WEDNESDAY NIGHT. THE LATEST ECMWF
(12Z) IS NOT AS OPTIMISTIC AS THE GFS...SHOWING ONLY ISOLATED
LIGHT QPF DURING THE SAME PERIOD OF TIME.
&&
.AVIATION...AS OF 9:45 PM PDT FRIDAY...ISOLATED SHOWERS WILL
TAPER OFF THIS EVENING. ADDITIONAL MAINLY WEAK LOWER LEVEL
ATMOSPHERIC COOLING IS FORECAST TONIGHT WHILE A MID-UPPER LEVEL
HIGH PRESSURE AREA STEADILY BUILDS OVER NORCAL TONIGHT AND
SATURDAY.
VICINITY OF KSFO...VFR. WESTERLY WINDS 10-15 KNOTS TONIGHT AND
SATURDAY MORNING...GUSTS TO NEAR 20 KNOTS POSSIBLE SAT AFTERNOON.
SFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY TERMINALS...VFR. MAINLY LIGHT WINDS.
&&
.MARINE...AS OF 9:29 PM PDT FRIDAY...A COLD FRONT WILL SWEEP
SOUTHEAST OVER THE WATERS WITH INCREASING NW WIND AND SEAS SUNDAY
THROUGH EARLY NEXT WEEK. GALE FORCE WINDS ARE POSSIBLE FOR SUNDAY
NIGHT IN OUR OUTER WATERS.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...SCA...ROUGH BAR ADVISORY FOR SF BAR
&&
$$
PUBLIC FORECAST: DYKEMA
AVIATION/MARINE: CANEPA
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK AND TWITTER AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
438 AM EDT SAT APR 23 2016
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THIS MORNING. HIGH PRESSURE WILL PREVAIL
THROUGH LATE NEXT WEEK. A COLD FRONT WILL THEN APPROACH THE AREA EARLY
NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
PRE-DAWN...A COLD FRONT WILL BE APPROACHING THE FORECAST AREA DURING
THE NEXT FEW HOURS. PRIOR TO ITS ARRIVAL WILL BE WIDESPREAD LOW
CLOUDS DEVELOPING ALONG WITH PATCHY TO AREAS OF FOG AS STRATUS DECKS
ARE ALREADY RUNNING LOW ALONG AND WEST OF I-95. CANNOT RULE OUT
SOME LOCALLY DENSE FOG OVER INLAND ZONES BUT WIDESPREAD DENSE FOG
IS NOT LIKELY. A FEW SPRINKLES ARE POSSIBLE WITH SOME LIGHTER RAINS
BRUSHING THE IMMEDIATE COASTAL AREAS NORTH OF THE SAVANNAH RIVER.
TEMPS IN THE LOW TO MID 60S.
TODAY...A PRE-FRONTAL WIND SHIFT TO THE WEST WILL OCCUR NEW DAWN
WITH THE ACTUAL COLD FRONT PUSHING SOUTH THROUGH THE AREA DURING
THE LATE MORNING INTO THE EARLY AFTERNOON HOURS. STRONG DRYING
THROUGHOUT THE ATMOSPHERE SHOULD ENSURE A MAINLY DRY DAY FOR MOST
AS SURFACE DEW POINTS FALL INTO THE 50S BY MIDDAY AND CERTAINLY
DURING THE AFTERNOON. ONE POSSIBLE EXCEPTION WILL BE ALONG THE
COASTAL ZONES AS LINGERING MID LEVEL SHORTWAVE ENERGY COUPLED WITH
ENHANCED LOW-LEVEL CONVERGENCE ALONG A PINNED SEA BREEZE/COLD
FRONT INTERSECTION WILL SUPPORT A RISK FOR ISOLATED SHOWERS LATE
THIS MORNING INTO THE AFTERNOON...MAINLY ALONG AND EAST OF U.S.
17 IN SE SOUTH CAROLINA AND EAST OF I-95 IN COASTAL GEORGIA.
FORECAST SOUNDINGS SHOW GOOD MID LEVEL INSTABILITY BUT THE AIR
MASS LOOKS TOO DRY TO SUPPORT VIGOROUS UPDRAFTS ALOFT. FOR
PERSISTENCE WE MAINTAINED A MENTION OF ISOLATED TSTMS BUT WE THINK
THE POTENTIAL LOOKS PRETTY LOW AT THIS POINT. HIGHS WILL BE IN
THE LOWER 80S TODAY WITH SOME MID 80S CERTAINLY POSSIBLE.
TONIGHT...SKIES WILL CLEAR AS A SECONDARY BACKDOOR DRY FRONT MOVES
THROUGH THE REGION...TURNING LIGHT WINDS NNE OVERNIGHT WITH LOWS
DIPPING TO THE MID/UPPER 50S INLAND TO NEAR 60 COASTAL ZONES..
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
A FAIRLY QUIET AND DRY PERIOD IS EXPECTED EARLY NEXT WEEK AS HIGH
PRESSURE BUILDS FROM THE NORTH ON SUNDAY...THEN BECOMES MORE
ESTABLISHED OVER THE WESTERN ATLANTIC MONDAY AND TUESDAY. SFC HIGH
PRESSURE ALONG WITH DEEP LAYERED RIDGING ALOFT WILL SUPPORT OVERALL
HIGH TEMPS IN THE UPPER 70S TO LOWER 80S ON SUNDAY...THEN LOWER 80S
ON MONDAY. BY TUESDAY...A LIGHT SOUTHERLY FLOW AND ABUNDANT SUNSHINE
WILL SUPPORT SLIGHTLY WARMER TEMPS...WITH AFTERNOON HIGHS PEAKING IN
THE MID TO UPPER 80S FOR MOST LOCATIONS. OVERNIGHT LOWS WILL ALSO
SHOW A WARMING TREND EARLY NEXT WEEK. A LIGHT EAST/NORTHEAST WIND
AND CLEAR SKIES WILL SUPPORT SUNDAY NIGHT LOWS IN THE UPPER 50S
INLAND TO LOWER 60S ALONG THE COAST. MONDAY NIGHT LOWS WILL BE MORE
MILD AS WINDS BECOME DIRECTLY ONSHORE...WITH TEMPS RANGING IN THE
LOW TO MID 60S.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
MOST AREAS WILL REMAIN DRY INTO THE MIDDLE OF NEXT WEEK AS A BROAD
MID/UPPER LVL RIDGE OF HIGH PRESSURE EXTENDS ACROSS THE SOUTHEASTERN
UNITED STATES. HOWEVER...WE CAN NOT RULE OUT A FEW SHOWERS AND/OR
THUNDERSTORMS WEDNESDAY AFTERNOON AND THURSDAY AFTERNOON AS WEAK MID
LVL WAVES OF ENERGY ROUND THE NORTHERN PERIPHERY OF THE RIDGE AND
PASS JUST TO OUR NORTH. A SLIGHT CHANCE OF SHOWERS WILL REMAIN IN
THE FORECAST ON WEDNESDAY...FOLLOWED BY A SLIGHT CHANCE OF
THUNDERSTORMS ON THURSDAY WHEN INSTABILITY IS HIGHER. BY FRIDAY...A
WEAK COLD FRONT WILL APPROACH THE AREA...PROMPTING ADDITIONAL SLIGHT
CHANCES OF SHOWERS AND/OR THUNDERSTORMS FRIDAY AFTERNOON. OVERALL
HIGH TEMPS WILL BE WARM DURING MID TO LATE WEEK...WITH AFTERNOON
HIGHS IN THE MID TO UPPER 80S. OVERNIGHT LOWS WILL ALSO BE MILD...IN
THE MID 60S.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
BOTH KCHS/KSAV WERE VFR AT 06Z INITIALIZATION TIME BUT LIFR
CIGS HAVE ALREADY MOVED INTO THE KSAV AIRPORT AND WHEN WINDS
DIMINISH IN A COUPLE OF HOURS WE WILL NEED TO WATCH FOR SOME
BUILD-DOWN DENSE FOG POTENTIAL. WHEN THE LOW LEVEL FLOWS TURNS
WEST OVERNIGHT...WE THINK SOME MVFR/IFR CIGS WILL ADVECT/DEVELOP
ALONG THE COASTAL CORRIDOR AROUND KCHS BUT OUR CONFIDENCE IS ONLY
FAIR GIVEN DIFFERENCES IN POINT SOUNDINGS FROM THE 13KM RAP AND
THE 00Z NAM MODELS. CONDITIONS SHOULD BECOME VFR BY MID TO LATE
MORNING AS CLOUDS MIX OUT IN LIGHT NW FLOW.
EXTENDED AVIATION OUTLOOK...VFR CONDITIONS ARE EXPECTED AT BOTH CHS
AND SAV TERMINALS.
&&
.MARINE...
TODAY...SOUTHWEST WINDS WILL OFFSHORE LATER THIS MORNING...THEN
TIP BACK TO SW FOR A WHILE THIS AFTERNOON. WIND SPEEDS SHOULD
MAINLY BE BELOW 15 KT AFTER SOME PRE-DAWN SURGES OVER OUTER
WATERS. A SECONDARY COLD FRONT WILL SLIDE SOUTH OVER THE WATERS
TONIGHT AND THERE WILL BE SOME SURGING NNE FLOW AFTER MIDNIGHT
THAT WILL WORK SOUTH TO THE GEORGIA WATERS BY DAWN ON SUNDAY.
THE SURGE COULD REACH 15-20 KT OFF THE CHARLESTON COAST WITH
SEAS BUILDING TO 4 FT LATE.
SUNDAY THROUGH THURSDAY...HIGH PRESSURE WILL CONTINUE TO BUILD FROM
THE NORTH ON SUNDAY...BEFORE BECOMING MORE ESTABLISHED OVER THE
COASTAL WATERS BY MONDAY. NORTHEAST WINDS WILL VEER AND BECOME MORE
ONSHORE AS THIS PROCESS UNFOLDS...BUT WILL REMAIN BELOW SMALL CRAFT
ADVISORY LEVELS. SEAS WILL RANGE BETWEEN 2-4 FEET...HIGHEST BEYOND
10 NM FROM THE COAST. ATLANTIC HIGH PRESSURE WILL THEN DOMINATE THE
PATTERN TUESDAY THROUGH THURSDAY...WITH SOUTH/SOUTHWEST WINDS AT OR
BELOW 15 KT OVER THE COASTAL WATERS. SEAS WILL RANGE BETWEEN 1-3
FT...HIGHEST IN OFFSHORE GEORGIA WATERS.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...DPB
LONG TERM...DPB
AVIATION...DPB
MARINE...DPB
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
108 AM EDT SAT APR 23 2016
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH LATE TONIGHT AND PUSH OFFSHORE
SATURDAY MORNING. HIGH PRESSURE WILL PREVAIL THROUGH LATE NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
OVERNIGHT...A FEW LINGERING SHOWERS POSSIBLE THE REST OF THE
NIGHT UNTIL THE ACTUAL COLD FRONT MOVES THROUGH LATE. THE BEST
LIFT AND DEEPER MOISTURE WAS ON THE WAY OUT. WE MAINTAINED PATCHY
FOG TO THE FORECAST AFTER 2 OR 3 AM OVER THE CENTRAL SAVANNAH
RIVER AREA AND SITES SOUTH TO THE ALTAMAHA RIVER BASIN. THIS WILL
BE THE RESULT OF THE WET GROUNDS...LITTLE WIND FIELDS AND A
STRENGTHENING NOCTURNAL INVERSION. PLUS THERE IS THE POSSIBILITY
OF STRATUS BUILD-DOWN. FOG/STRATUS COULD CERTAINLY SPREAD FURTHER
NORTH/NE...BUT FOR NOW WE ARE SHOWING IT JUST WHERE THE LOWEST
CONDENSATION PRESSURE DEFICITS AND GEOSTROPHIC WINDS AT 1000 MB
ARE LESS THAN 10 KT. LOWS IN THE LOWER TO MID 60S.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY/...
SATURDAY...A WIND PRE-FRONTAL WIND SHIFT TO THE WEST WILL OCCUR
AROUND SUNRISE WITH THE ACTUAL COLD FRONT PUSHING SOUTH THROUGH THE
AREA DURING THE LATE MORNING INTO THE EARLY AFTERNOON HOURS.
LINGERING 500 HPA SHORTWAVE ENERGY COUPLED WITH ENHANCED LOW-LEVEL
CONVERGENCE ALONG THE SEA BREEZE/COLD FRONT INTERSECTION WILL
SUPPORT A RISK FOR ISOLATED SHOWERS AND PERHAPS A TSTM FOR MUCH OF
THE DAY...MAINLY ACROSS THE CHARLESTON TRI-COUNTY AREA AND EXTENDING
SOUTH ALONG THE COAST INTO THE SAVANNAH METRO AREA. CAPPED POPS AT
20 PERCENT FOR NOW...BUT HIGHER POPS MAY EVENTUALLY BE NEEDED...
ESPECIALLY IN THE BEAUFORT-MCCLELLANVILLE AREA WHERE LOW-LEVEL
CONVERGENCE WILL BE THE STRONGEST. MODIFIED SOUNDINGS SHOW ENOUGH
INSTABILITY TO SUPPORT A MENTION OF TSTMS. HIGHS WILL GENERALLY TOP
OUT IN THE LOWER 80S AWAY FROM THE BEACHES. HIGH PRESSURE WILL BUILD
INTO THE AREA SATURDAY NIGHT AS THE COLD FRONT PUSHES FARTHER AWAY.
LOWS WILL RANGE FROM THE UPPER 50S INLAND TO THE LOWER-MID 60S AT
THE COAST...WARMEST ALONG THE GEORGIA BEACHES WHERE WINDS WILL TURN
ONSHORE AND HELP MODERATE CONDITIONS.
SUNDAY AND MONDAY...HIGH PRESSURE WILL EXTEND ACROSS THE AREA AS
DEEP LAYERED RIDGING BUILDS ALOFT. THIS WILL RESULT IN MOSTLY DRY
WEATHER WITH TEMPERATURES SLIGHTLY ABOVE NORMAL FOR LATE APRIL.
THERE ARE SIGNALS THAT A PUSH OF MOISTURE ASSOCIATED WITH THE
ONSHORE FLOW COULD SUPPORT ISOLATED SHOWERS AND POSSIBLY A TSTM OR
TWO SOUTH OF I-16 AHEAD OF THE SEA BREEZE MONDAY AFTERNOON. WILL GO
WITH A SLIGHT CHANCE OF SHOWERS/TSTMS THERE WITH RAIN-FREE
CONDITIONS ELSEWHERE. HIGHS WILL WARM INTO THE LOWER-MID 80S EACH
DAY AWAY FROM THE COAST WITH LOWS MONDAY MORNING DROPPING INTO THE
LOWER 60S INLAND WITH MID-UPPER 60S AT THE COAST...WARMEST ALONG THE
GEORGIA BEACHES.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MOST AREAS WILL REMAIN DRY INTO THE MIDDLE OF NEXT WEEK AS A BROAD
MID/UPPER LVL RIDGE OF HIGH PRESSURE EXTENDS ACROSS THE SOUTHEASTERN
UNITED STATES. HOWEVER...WE CAN NOT RULE OUT A FEW SHOWERS AND/OR
THUNDERSTORMS WEDNESDAY AND THURSDAY AFTERNOON AS SFC TEMPS PEAK IN
THE MID AND UPPER 80S AWAY FROM THE COAST. A SLIGHT CHANCE OF
SHOWERS AND THUNDERSTORMS WILL REMAIN IN THE FORECAST...WITH
GREATEST CHANCES OCCURRING ALONG AN AFTERNOON SEABREEZE MOVING
INLAND. OVERNIGHT LOWS WILL BE MILD EACH NIGHT...IN THE LOW TO MID
60S.
&&
.AVIATION /04Z SATURDAY THROUGH WEDNESDAY/...
BOTH KCHS/KSAV WERE VFR AT 06Z INITIALIZATION TIME BUT LOWER
CLOUDS WERE DEVELOPING UPSTREAM FROM BOTH TERMINALS. WHEN THE
LOW LEVEL FLOWS TURNS WEST OVERNIGHT...WE THINK SOME MVFR/IFR
CIGS WILL ADVECT/DEVELOP ALONG THE COASTAL CORRIDOR BUT OUR
CONFIDENCE IS ONLY FAIR GIVEN DIFFERENCES IN POINT SOUNDINGS
FROM THE 13KM RAP AND THE 00Z NAM MODELS. CONDITIONS SHOULD
BECOME VFR BY MID TO LATE MORNING AS CLOUDS MIX OUT IN LIGHT
NW FLOW.
EXTENDED AVIATION OUTLOOK...MAINLY VFR.
&&
.MARINE...
OVERNIGHT...ATLANTIC HIGH PRESSURE FAR OFF THE SE COAST IN THE
ATLANTIC WILL PULL FURTHER EAST AND GIVE WAY TO THE APPROACH OF A
COLD FRONT LATE. SW WINDS AS HIGH AS 15 OR PERHAPS 20 KT EARLY
WILL VEER TO MORE WEST AND DROP OFF 5 OR 10 KT LATE AS THE COLD
FRONT SLIDES IN BY DAYBREAK SATURDAY. SEAS WILL BEGIN THE NIGHT AT
3-5 FT...HIGHEST OVERT AMZ374 THEN SUBSIDE ABOUT A FOOT LATE AS
THE FLOW VEERS TO AN OFFSHORE DIRECTION. THE STRONGEST
T-STORMS HAVE ENDED FOR ALL BUT THE FAR NORTHERN PART OF AMZ350
EARLY ON.
SATURDAY...SOUTHWEST WINDS SATURDAY WILL TURN NORTH AND EVENTUALLY
NORTHEAST SATURDAY NIGHT AS A COLD FRONT PUSHES OFFSHORE AND HIGH
PRESSURE NOSES IN FROM THE NORTH. THE GRADIENT WILL BEGIN TO TIGHTEN
EARLY SUNDAY MORNING WITH SPEEDS POTENTIALLY REACHING AS HIGH AS 15
KT...ESPECIALLY ALONG THE LOWER SOUTH CAROLINA COASTAL WATERS...
OTHERWISE WINDS WILL REMAIN AROUND 10 KT OR SO WITH SEAS 2-3 FT
NEARSHORE...3-4 FT OFFSHORE...SUBSIDING TO 1-2 FT NEARSHORE...2-3 FT
OFFSHORE.
SUNDAY AND MONDAY...EAST TO NORTHEAST WINDS WILL PREVAIL WITH WINDS
GRADUALLY BECOMING MORE UNIFORMLY ONSHORE BY MONDAY. WINDS LOOK TO
REMAIN LESS THAN 15 KT WITH SEAS 1-2 FT NEARSHORE...2-3 FT OFFSHORE.
TUESDAY AND WEDNESDAY...WINDS WILL TURN MORE SOUTHERLY THROUGH THE
PERIOD AS HIGH PRESSURE SHIFTS OFFSHORE. LOCAL ENHANCEMENTS TO WIND
FIELD ARE LIKELY EACH AFTERNOON ALONG THE LAND/SEA INTERFACE AS THE
SEA BREEZE MOVES INLAND. SMALL CRAFT ADVISORY CONDITIONS ARE NOT
EXPECTED.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
Area Forecast Discussion
National Weather Service Paducah KY
304 AM CDT SAT APR 23 2016
.SHORT TERM...(Today through Monday night)
Issued at 304 AM CDT Sat Apr 23 2016
The main issue early this morning is surface high pressure surging
southwest into the region. It is keeping the northeast winds
stirred up and ushering in a solid layer of IFR level clouds that
guidance does not have a good handle on. The clouds now cover much
of the Evansville Tri State, and should continue to push
southward, per the RAP low-level RH forecast, toward the Lakes and
Pennyrile. Figure that the low clouds will dissipate quickly this
morning by 15Z.
The clouds will have more of an impact on aviation concerns, and
the AVIATION of this discussion has been updated as well.
Temperatures may be held up just a bit under the cloud cover
through daybreak, but not much, and they may hold down highs a
degree or two in the east. With plenty of sunshine expected this
afternoon and dry air in place over the region, this forecast still
leaned toward the warmer side of the guidance envelope for highs.
Surface high pressure will continue to dominate the region tonight,
so clear skies and light winds will allow for good radiational
cooling. Definitely went at or below coolest guidance for tonight`s
lows in most locations. The surface high will push east of the
area on Sunday, allowing south winds to return across the region.
With high pressure aloft resulting in mostly sunny skies, went at
or above the warmest guidance. Most of the area should be in the
lower 80s.
South winds will stay up in the 5 to 10 mph range Sunday night, so
it should be a milder night. Skies will still be no worse than
partly cloudy, so will not go much above guidance. Lows should be
around 60.
As our next potential storm system settles over the Four Corners
region Monday, the flow aloft over our region will become nearly
zonal. A surface cold front will become strung out nearly west to
east well to our north. This should keep us high and dry Monday
and most likely Monday night, too. Will have the slightest of PoPs
for SHRA/TSRA in the Perryville, Pinckneyville, and Mt Vernon
areas on Monday and along the I-64 corridor Monday night, but this
is mainly just to provide a buffer with our surrounding forecast
areas.
The 00Z models do not indicate much increase in clouds Monday, so
temperatures should soar into the 80-85F range, which is well above
guidance. Lows Monday night will continue to trend milder. With a
bit more wind expected, and increasing clouds overnight, lows will
be in the 60-65F range.
.LONG TERM...(Tuesday through Friday)
Issued at 304 AM CDT Sat Apr 23 2016
The upper-level split flow pattern will consist of an active
southern stream across the United States, and a more diffuse polar
jet across northern Canada. A series of shortwaves will eject
northeast out of the Desert Southwest to the central Plains, then
finally into the Great Lakes before weakening. There are still
significant model differences concerning the timing of these
shortwaves and their associated frontal systems. Overall, the
pattern looks rather warm and wet given the storm track to our
north.
As far as the daily specifics, the models are in good agreement for
Tuesday. A narrow 500 mb ridge will pass over the Mississippi Valley
ahead of the first shortwave, which will be emerging into the
southern high Plains. Beneath the ridge aloft, the models continue
to sag a weak frontal boundary south to Interstate 64 by late in the
day Tuesday. The air mass is forecast to be warm and unstable south
of the front, moreso than with other fronts this spring. Therefore,
chance pops will be kept in the forecast despite weak forcing aloft.
The weak frontal boundary should continue south into the Lower Ohio
Valley Tuesday night. Beyond that, the models really start to
diverge on the timing of subsequent frontal passages. The front may
move south of our area before returning north as a warm front during
the middle of the week. A weakening surface low will then move east
across the Midwest Wednesday night and Thursday. A cold front
trailing southwest from the low will move across our region, but
timing differences are quite large. The faster 00z ecmwf is
consistent with the previous NWS forecast and the 12z Fri ecmwf
ensemble mean. However, the slower 00z gfs has support from the
00z gefs. In a nutshell, pops will be in the high chance to likely
category Wed and Wednesday night. Compared with previous systems
this spring, there will be plenty of moisture and instability for
convection. Wind profiles will be moderately strong. A few intense
storms are possible.
Late in the week, another weak shortwave ridge will traverse the
Mississippi and Ohio Valleys between systems. The weak cold front
will be suppressed south of our region. It now appears Friday will
be dry in many areas, but a slight chance pop will be retained
closer to the frontal boundary in the Tennessee border counties
and much of se Missouri. Temperatures should be a little cooler
north of the front, with highs Friday from 70 to 75.
&&
.AVIATION...
Issued at 304 AM CDT Sat Apr 23 2016
Have updated the forecasts through daybreak to account for a
solid layer of IFR ceilings overspreading both KEVV and KOWB early
this morning. Hopefully, they will not reach KPAH, but cannot
completely rule it out at this time. Figure that the ceilings and
associated MVFR visibilities will dissipate by 15Z. Otherwise VFR
conditions should dominate the entire forecast period, with only
gradual wind shifts.
&&
.PAH Watches/Warnings/Advisories...
IL...None.
MO...None.
IN...None.
KY...None.
&&
$$
SHORT TERM...DRS
LONG TERM...MY
AVIATION...DRS/Smith
AREA FORECAST DISCUSSION
NWS JACKSON KY
338 AM EDT SAT APR 23 2016
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 338 AM EDT SAT APR 23 2016
UPPER TROUGH CURRENTLY PUSHING EAST ACROSS WEST VIRGINIA WILL
BRING DEEP LAYER SUBSIDENCE TO EASTERN KENTUCKY...LEADING TO
GRADUALLY CLEARING SKIES LATER THIS MORNING. BEFORE THEN...A BATCH
OF LOW STRATUS WILL CONTINUE TO PROPAGATE SOUTH ACROSS THE OHIO
VALLEY AND INTO THE COMMONWEALTH AHEAD OF A SURFACE RIDGE BUILDING
ACROSS THE GREAT LAKES AS LOW LEVELS REMAIN RATHER MOIST. THIS
SHOULD KEEP FOG PATCHY IN NATURE AS RADIATIONAL COOLING WILL BE
IMPEDED BY THE INCOMING CLOUD DECK. HOWEVER...NOT EXPECTING ANY
ADDITIONAL RAINFALL WITH UPPER SUPPORT OFF TO THE EAST AND DRYING
MID-UPPER LEVELS.
WILL SEE ALL FOG MIX OUT BY MID-LATE MORNING AS DRIER AIR
CONTINUES TO BUILD TOWARD THE SURFACE. CLOUD COVER WILL ERODE WITH
SKIES CLEARING OUT BY LATER THIS AFTERNOON INTO TONIGHT. LIGHT
NORTHERLY WINDS WILL BRING SUBTLE COOL AIR ADVECTION AND ACT TO
HOLD HIGH TEMPERATURES THIS AFTERNOON IN THE MID 60S TO LOW 70S.
SURFACE HIGH PRESSURE MIGRATING ACROSS THE EASTERN GREAT LAKES
INTO THE APPALACHIANS WILL KEEP SKIES CLEAR TONIGHT AND WINDS
LIGHT. GIVEN RECENT PRECIPITATION FRIDAY...AT LEAST PATCHY VALLEY
FOG SHOULD BE A CERTAINTY AS AN APPRECIABLE RIDGE/VALLEY SPLIT
DEVELOPS. EXPECT A FEW OF THE MORE SHELTERED VALLEY LOCALES TO
DROP INTO THE UPPER 30S WITH MOST RIDGE LOCATIONS GENERALLY IN THE
LOW-MID 40S.
BUILDING HEIGHTS ALOFT AND VEERING SOUTHERLY WINDS WILL LEAD TO A
NOTICEABLE WARMUP FOR SUNDAY AS TEMPERATURES TOP OUT IN THE UPPER
70S TO LOWER 80S.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 338 AM EDT SAT APR 23 2016
OUR WEATHER SHOULD BE MORE ACTIVE NEXT WEEK AS SHORTWAVES EJECT
OUT OF A WESTERN CONUS THROUGH AND TRACK JUST TO OUR WEST INTO THE
UPPER MIDWEST AND GREAT LAKES REGION. AT THE SURFACE...A FRONTAL
BOUNDARY WILL DROP INTO THE REGION BY TUESDAY AND HANG AROUND
THROUGH MIDWEEK. A LOW PRESSURE SYSTEM WILL ALSO GET ORGANIZED
OVER THE PLAINS MIDWEEK. THIS SYSTEM WILL TRACK EASTWARD SENDING A
COLD FRONT TOWARD OUR REGION LATE IN THE WORK WEEK.
SENSIBLE WEATHER WILL FEATURE A NICE WARM MONDAY WITH PLENTY OF
SUNSHINE AND HIGHS IN THE LOW TO MID 80S. THE THREAT FOR SHOWERS
AND THUNDERSTORMS WILL THEN INCREASE FROM NORTH TO SOUTH LATE
MONDAY NIGHT INTO TUESDAY AS THE FRONT DROPS SOUTH INTO THE
REGION. JUST SCATTERED SHOWERS/STORMS ARE ANTICIPATED TUESDAY AND
WEDNESDAY AS THE FRONT IS NOT PARTICULARLY STRONG OR EQUIPPED WITH
MUCH MOISTURE. OUR BEST CHANCE FOR SHOWERS/STORMS APPEARS TO BE
WEDNESDAY NIGHT INTO THE DAY ON THURSDAY AS THE COLD FRONT ENTERS
THE SCENE FROM THE WEST. LESSER RAIN CHANCES ARE FORECAST FOR
FRIDAY...BUT CANNOT REMOVE THEM TOTALLY WITH THE FRONT AND
ACCOMPANYING LOW PRESSURE SYSTEM REMAINING NEARBY PER THE GFS AND
ECMWF.
DESPITE THE DAILY CHANCE OF RAIN TUESDAY THROUGH FRIDAY...A
WIDESPREAD SOAKING RAINFALL APPEARS UNLIKELY AT THIS TIME.
ALSO...DESPITE THE FRONTAL PASSAGE LATE IN THE WEEK...TEMPS WILL
REMAIN WELL ABOVE NORMAL...ONLY DROPPING FROM THE LOW TO MID 80S
TUESDAY THROUGH THURSDAY TO THE MID TO UPPER 70S ON FRIDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 150 AM EDT SAT APR 23 2016
MAIN ISSUE THIS CYCLE WILL BE LOW STRATUS APPROACHING FROM THE
OHIO VALLEY. HAVE SEEN SEVERAL BREAKS IN THIS...SUGGESTING NOT
EVERYONE WILL SEE PERSISTENT LOWERING CEILINGS. MVFR CEILINGS LOOK
LIKE A DECENT BET FOR ALL SITES AT SOME POINT. FOG AND REDUCED
VISIBILITIES MAY BECOME AN ISSUE IN LIEU OF LOWERING CEILINGS
LATER TONIGHT AND SATURDAY MORNING. LIGHT NORTHWEST WINDS WILL
CONTINUE THROUGH THE PERIOD AS CLOUD COVER SLOWLY DECREASES
THROUGH THE DAY SATURDAY AS HIGH PRESSURE SETTLES INTO EASTERN
KENTUCKY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GUSEMAN
LONG TERM...ABE
AVIATION...GUSEMAN
[top]
Area Forecast Discussion
National Weather Service Louisville KY
312 AM EDT SAT APR 23 2016
.SHORT TERM (Now through Sunday)...
Issued 240 AM EDT Sat Apr 23 2016
...A pleasant weekend in store...
The synoptic pattern early this morning features a weak trough
across the eastern CONUS, with another more substantial trough
building into the western CONUS. Ridging in between these two
features will build into the Ohio Valley through the period,
bringing a very pleasant weekend to the region.
Low clouds continue to stream in from the north early this morning.
The latest HRRR has a pretty good handle on these clouds, thus have
leaned toward its solution for today. These clouds should mix out
pretty quickly by mid to late morning, making way for quite a bit of
sunshine this afternoon. The clouds may slow our temperatures rise
a bit this morning, but think the solar insolation this afternoon
should be enough to get temperatures into the upper 60s and lower
70s.
Surface ridging will slide east of the region tonight into Sunday.
Southerly flow will commence on the backside of this high, which
will allow temperatures to warm up for Sunday. Will go above the
general guidance consensus, which places highs in the lower 80s
under mostly sunny skies.
.LONG TERM (Sunday night through Friday)...
Issued at 310 AM EDT Sat Apr 23 2016
...A more active convective weather pattern at times next week...
The synoptic pattern at the start of the long term period will
feature zonal to WSW flow over the Ohio Valley due to an upstream
western CONUS trough. This regime will allow for a couple of
disturbances to eject out of the trough which will make for a more
active weather pattern beginning around Monday night/Tuesday of next
week.
While confidence in the overall pattern is high, confidence in
timing of each feature ejecting out of the western trough is rather
low. As a result, have gone with more of an ensemble approach to
the forecast and stuck with a general model/ensemble blend.
A warm front will sharpen well to the north of the region on Monday.
As a result, any precipitation will remain out of the Ohio Valley
which will allow us to warm rather nicely during the afternoon hours
as we will sit on the warm side of the boundary. Have upper highs
well into the 80s on Monday afternoon, with some upper 80s readings
not out of the question in the typically warmer locations.
The first PV anomaly will slide southeast along the front Monday
night into Tuesday. This will help push the front into the Ohio
River Valley, sparking showers and thunderstorms as it drives
southeast. The kinematics with this system are not impressive, with
deep layer shear only around 20-30 knots, so do not see an organized
severe threat with this activity on Tuesday (maybe just a few strong
storms depending on how well we destabilize).
The western trough will begin to eject into the Central Plains late
Tuesday into Wednesday, which will push the cold front back to the
north as a warm front. A few thunderstorms will be possible
Wednesday along/south of the boundary lifting north, but it appears
the better chance of thunderstorms will come mainly Wednesday night
as the main forcing for ascent pushes through the Ohio Valley. Wind
fields are more impressive with this system, but timing as it stands
now is not very favorable. However, we will continue to monitor
this system closely as substantial differences remain in the
deterministic/ensemble guidance suite.
The GFS is much slower, keeping storm chances going through
Thursday, with the ECMWF showing a much drier solution. Will split
the difference and continue with chance pops Thursday, but go mainly
dry for Friday as the guidance consensus is to finally push the cold
front to the south of the region.
Temperatures through the period will be very dependent on the timing
of precipitation, but highs generally in the 80s with lows in the
upper 50s/60s is likely through much of next week, until the
slightly cooler air arrives Friday.
&&
.AVIATION (06Z TAF Update)...
Updated at 1255 AM EDT Sat Apr 23 2016
Overnight concern remains on low clouds currently dropping southward
through central Indiana this morning. Last few runs of the HRRR and
HRRRX suggest that this trend will continue and the low cloudiness
would expand across KY overnight. Given current trends, it appears
that may be a little overdone. However, it does look like some low
clouds will likely affect KSDF between roughly 23/08 through about
23/14Z. Some MVFR cloudiness may affect KLEX between 23/08-14Z as
well. Further south at KBWG, surface patchy fog may be more of an
issue than the low cloudiness. Surface winds overnight will remain
out of the north and light. A return to VFR conditions is expected
Saturday morning with the terminals seeing mostly clear skies after
23/15Z.
&&
.LMK Watches/Warnings/Advisories...
KY...NONE.
IN...NONE.
&&
$$
Short Term........KJD
Long Term.........KJD
Aviation..........MJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
150 AM EDT SAT APR 23 2016
.UPDATE...
ISSUED AT 150 AM EDT SAT APR 23 2016
LOW STRATUS CONTINUES TO TRACK SOUTH ACROSS THE OHIO VALLEY TOWARD
THE COMMONWEALTH. SEVERAL BREAKS CAN BE SEEN IN SATELLITE
IMAGERY...SUGGESTING A NON-UNIFORM PATTERN TO THE CLOUD COVER. IF
SKIES CAN REMAIN MOSTLY CLEAR FOR A MAJORITY OF TONIGHT/EARLY
SATURDAY...MAY SEE AN UPTICK IN FOG THICKNESS AND COVERAGE AND
NEED TO BEEF UP WORDING IN THE FORECAST. FOR NOW...PATCHY FOG
REMAINS IN PLAY PENDING EVOLUTION OF INCOMING STRATUS.
UPDATE ISSUED AT 1036 PM EDT FRI APR 22 2016
CURRENT CONDITIONS ACROSS EASTERN KENTUCKY POSE AN INTERESTING
FORECAST PROBLEM FOR TONIGHT. UPDATED THE FORECAST TO REMOVE POPS
FOR THE NIGHT AS ALL THIS ACTIVITY HAS EXITED AND WHILE SOME
UPPER LEVEL SUPPORT IS STILL PASSING THROUGH TO THE NORTH...NO
PRECIP IS EXPECTED TONIGHT. THE SECOND ISSUE IS CONCERNING THE LOW
LEVEL CLOUD COVER TO THE NORTHWEST. AT THE CURRENT TIME...THIS IS
SLOW TO MOVE INTO EASTERN KENTUCKY. THE CONCERN IS THAT IF THERE
ARE MORE BREAKS IN THE CLOUD COVER TONIGHT WITH THE RAINFALL FROM
EARLIER TODAY...THE FOG WILL BECOME MORE EXTENSIVE AND EVEN DENSE
IN SOME AREAS. FOR NOW HAVE ADDED PATCHY FOG TO THE ZFP BUT THIS
MAY NEED TO BE REEVALUATED IF THE CLOUD COVER DOES NOT SET UP
TONIGHT. A NEW ZFP HAS BEEN SENT AND THE HWO WAS UPDATED TO REMOVE
THUNDER.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 340 PM EDT FRI APR 22 2016
LATEST RADAR IMAGERY SHOWS THREE SEPARATE LINES/AREAS OF
SHOWERS/THUNDERSTORMS...THE FIRST OF WHICH IS CURRENTLY MOVING
THROUGH EASTERN KENTUCKY AND HAS PRODUCED PEA AND NICKEL SIZE
HAIL. THE SECOND LINE IS DEVELOPING ALONG THE WESTERN BORDER OF
THE FORECAST AREA AND IS ASSOCIATED WITH THE COLD FRONT.
FINALLY...THE THIRD AREA OF SHOWERS/STORMS IS ASSOCIATED WITH THE
UPPER LEVEL LOW AND IS LOCATED OVER NORTH CENTRAL KY/SOUTHWEST OH
ATTM. THESE THREE ROUNDS OF RAIN/THUNDERSTORMS WILL CONTINUE TO
MOVE THROUGH THE AREA THIS EVENING AND INTO THE OVERNIGHT HOURS
BUT THE STRENGTH OF THE STORMS SHOULD WANE A BIT AFTER SUNSET.
THROUGH THIS EVENING...HOWEVER...SMALL HAIL AND GUSTY WINDS WILL
BE POSSIBLE WITH ANY STRONG STORM.
RAIN SHOULD EXIT TO OUR EAST BY 06Z AS THE UPPER LEVEL LOW SHIFTS
INTO WEST VIRGINIA. RIDGING WILL BUILD INTO THE REGION THROUGHOUT
THE DAY ON SATURDAY...HELPING TO CLEAR OUT THE CLOUDS AND BRING A
RETURN OF SUNSHINE FOR MOST OF THE WEEKEND.
TEMPERATURES THROUGH THE SHORT TERM WILL REMAIN NEAR NORMAL WITH
LOWS BOTH NIGHTS IN THE UPPER 40S/LOW 50S AND AFTERNOON HIGHS NEAR
THE 70 DEGREE MARK.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 340 PM EDT FRI APR 22 2016
DRY WARM WEATHER WILL PREVAIL FOR THE LATTER PART OF THE WEEKEND AND
INTO EARLY NEXT WEEK AS HIGH PRESSURE DRIFTS EAST ACROSS THE GREAT
LAKES AND OH VALLEY. NEXT WEEK WILL FEATURE A LARGE UPPER LEVEL LOW
MOVING FROM THE SOUTHWEST UNITED STATES TOWARDS THE GREAT LAKES FROM
TUESDAY INTO THURSDAY. AT THE SURFACE A FRONTAL BOUNDARY WILL DRIFT
SOUTH INTO THE OH AND TN VALLEYS AND REMAIN IN THE VICINITY OF KY.
THIS WILL RESULT IN SHOWER AND THUNDERSTORM CHANCES FROM THE TUESDAY
THROUGH THE REMAINDER OF THE WEEK. THE BEST DYNAMICS WILL REMAIN
WELL TO OUR WEST NEXT WEEK...WITH THE CHANCES FOR STRONGER STORMS
BEING OVER THE PLAINS INTO THE MS VALLEY. TEMPERATURES WILL CONTINUE
TO RUN ABOVE NORMAL NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 150 AM EDT SAT APR 23 2016
MAIN ISSUE THIS CYCLE WILL BE LOW STRATUS APPROACHING FROM THE
OHIO VALLEY. HAVE SEEN SEVERAL BREAKS IN THIS...SUGGESTING NOT
EVERYONE WILL SEE PERSISTENT LOWERING CEILINGS. MVFR CEILINGS LOOK
LIKE A DECENT BET FOR ALL SITES AT SOME POINT. FOG AND REDUCED
VISIBILITIES MAY BECOME AN ISSUE IN LIEU OF LOWERING CEILINGS
LATER TONIGHT AND SATURDAY MORNING. LIGHT NORTHWEST WINDS WILL
CONTINUE THROUGH THE PERIOD AS CLOUD COVER SLOWLY DECREASES
THROUGH THE DAY SATURDAY AS HIGH PRESSURE SETTLES INTO EASTERN
KENTUCKY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GUSEMAN
SHORT TERM...JVM
LONG TERM...SBH
AVIATION...GUSEMAN
Area Forecast Discussion
National Weather Service Louisville KY
1255 AM EDT SAT APR 23 2016
...Updated Aviation Discussion...
.SHORT TERM (Now through Sunday)...
Issued 300 PM EDT Fri Apr 22 2016
...Scattered showers til early evening then a nice weather weekend...
As expected, scattered to numerous showers and thunderstorms have
developed immediately south and east of the mid-level trough, with
greatest precip coverage over our northern and eastern counties. In
these areas, marginal instability (surface-based lifted indices -2
to -3 and CAPE 500-1000 J/kg) is supporting the convective elements.
The strongest cores will be capable of pea size hail (we received
one such report so far), brief heavy rain, and several lightning
strikes. By early evening as daytime heating wanes, showers will
weaken and eventually dissipate. Thereafter, model cross-sections
suggest that some low clouds may persistent or develop later tonight
in areas, with some light fog possible in some locations.
For Saturday and Sunday, a ridge of high pressure at the surface
will cross the Ohio Valley with plenty of sunshine. There could be a
few flat afternoon cumulus clouds Saturday and some high cirrus
Sunday, but that`s about it. Nights will be cool in the upper 40s
and lower 50s Saturday morning, and mid 40s to about 50 Sunday
morning. Highs Saturday afternoon will be in the upper 60s in east-
central KY to lower 70s elsewhere. Warmer Sunday with highs in the
upper 70s and lower 80s. Winds Saturday will be northeast 5-10 mph
and south 5-10 mph on Sunday.
.LONG TERM (Sunday night through Friday)...
Issued at 315 PM EDT Fri Apr 22 2016
...A more active convective weather pattern at times next week...
Pattern in the extended will feature a mean trough in the western
U.S. and a mix of more zonal flow or flat ridging over the Ohio
Valley. At least two strong systems are progged by all models to
eject out of the western trough next week through next weekend, with
severe weather at times over the southern-central Plains into the
mid MS Valley, and possibly into the Ohio Valley.
Monday-Tuesday...
On Monday, a shortwave will move across the northern Plains then
across the Great Lakes. This will drive a cold front southeastward
across the Ohio Valley late Monday and Tuesday. The air mass south
of the front will be warm (generally lower-mid 80s) and become more
unstable. Scattered thunderstorms could develop late Monday night
over southern IN closer to the front, and areawide on Tuesday along
and south of the boundary. Models differ on frontal location with
GFS a little farther south than ECMWF. Either way, the boundary will
become stationary over/near the area. Organized severe storms are
not expected but a few strong storms are certainly possible Tuesday
afternoon. Models suggest that scattered showers and storms could
occur or move in from the west Tuesday night as well(especially the
GEM model).
Wednesday-Wednesday night...
As a strong storm system ejects out of the southwestern U.S. and
across the Plains states Tuesday, thunderstorms could push into or
through the mid MS Valley by Wednesday morning. Much uncertainty
exists with how potential severe weather well to our south and west
Tuesday afternoon and night will evolve and affect our area
Wednesday and Wednesday night, as well as the interaction with the
frontal zone in our vicinity. It is possible that some remnant
storms could affect our area first half of Wednesday. However, late
Wednesday and/or Wednesday night looks potentially interesting as a
moderately unstable air mass develops (assuming enough diurnal
isolation) and as the exit region of a mid/upper level jet streak
approaches the Ohio Valley. This could potentially result in
cellular and/or linear convection during this time, with a few
severe storms possible. Our forecast will carry higher probabilities
of precip during this time period.
Thursday-Friday...
Depending on how the Wednesday system evolves, associated
convection could linger or redevelop along a trailing cold front
Thursday afternoon, but be more scattered in nature. Then drier air
should return by Friday as the system moves through. Highs Friday
should be cooler in the post-frontal air mass than on Thursday.
Next Saturday-Sunday...
Although this is past the current forecast period, another strong
system could eject out of the southwestern U.S. and across the
Plains. This could bring another round of convection to the Ohio
Valley sometime next weekend.
&&
.AVIATION (06Z TAF Update)...
Updated at 1255 AM EDT Sat Apr 23 2016
Overnight concern remains on low clouds currently dropping southward
through central Indiana this morning. Last few runs of the HRRR and
HRRRX suggest that this trend will continue and the low cloudiness
would expand across KY overnight. Given current trends, it appears
that may be a little overdone. However, it does look like some low
clouds will likely affect KSDF between roughly 23/08 through about
23/14Z. Some MVFR cloudiness may affect KLEX between 23/08-14Z as
well. Further south at KBWG, surface patchy fog may be more of an
issue than the low cloudiness. Surface winds overnight will remain
out of the north and light. A return to VFR conditions is expected
Saturday morning with the terminals seeing mostly clear skies after
23/15Z.
&&
.LMK Watches/Warnings/Advisories...
KY...NONE.
IN...NONE.
&&
$$
Short Term........TWF
Long Term.........TWF
Aviation..........MJ
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
131 AM EDT SAT APR 23 2016
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 309 PM EDT FRI APR 22 2016
WV IMAGERY AND RAP ANALYSIS INDICATED WNW MID/UPPER LEVEL FLOW INTO
THE NRN LAKES ON THE PERIPHERY OF A DEEP LOW INTO NRN HUDSON BAY.
LOW LEVEL CAA WITH NRLY WINDS KEPT LOW CLOUDS ACROSS MUCH OF THE
FCST AREA INTO EARLY AFTERNOON...BUT NOW BUILDING HIGH PRES FM NW OF
LAKE SUPERIOR HAS ALLOWED FOR INFLUX OF DRIER AIR AND ERODING CLOUD
COVER MID-LATE THIS AFTERNOON. MAX TEMPS TODAY HAVE RANGED FM THE
MID TO UPPER 30S ALONG LAKE SUPERIOR TO AROUND 50F CLOSER TO THE WI
BORDER.
TONIGHT...ALTHOUGH WINDS WILL DIMINISH WITH THE SFC HIGH PRES RIDGE
SLIDING OVER THE AREA...WAA MID CLOUDS FROM SRN MANITOBA AND NRN MN
ARE EXPECTED TO SPREAD IN FM THE W OVERNIGHT DUE TO INCREASING 295-
300K ISENTROPIC ASCENT WHICH SHOULD KEEP TEMPS FROM DROPPING OFF TOO
FAR. TEMPS MAY STILL FALL INTO THE MID 20S CENTRAL AND EAST BEFORE
THE CLOUDS MOVE IN. OTHERWISE...EXPECT MIN READINGS IN THE LOWER 30S
WEST.
SAT...A WNW FLOW ALOFT WILL DOMINATE THE UPPER GREAT LAKES BETWEEN
AN UPR RIDGE AXIS IN THE PLAINS AND AN UPR TROUGH OVER ERN CANADA.
MODELS SHOW MID/HIGH CLDS CONTINUING TO SPREAD INTO UPPER MI WITH
WAA TO THE NE OF SHARPENING FNT FM THE DAKOTAS INTO MN.
HOWEVER...THE MAJORITY OF MODELS INDICATE LINGERING LLVL DRY AIR
ASSOCIATED WITH SLOWLY DEPARTING SFC HIGH PRES WL KEEP THE CWA DRY.
ONLY THE 12Z GFS SHOWS RAIN REACHING INTO THE NW CWA WHERE MODELS
INDICATE PROXIMITY TO STRONGER H7 FGEN ALONG AND NE OF SHARPENING
FRONTAL BOUNDARY.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 434 PM EDT FRI APR 22 2016
BUILDING HEIGHTS OVER GREENLAND (500MB HEIGHTS UP TO 2.5 STANDARD
DEVIATIONS ABOVE CLIMATOLOGY) THRU EARLY NEXT WEEK WILL SUPPORT
TROFFING OVER SE CANADA AND FAIRLY COLD AIR FOR LATE APR ACROSS
ONTARIO AND QUEBEC. AS A RESULT...A RATHER SHARP BAROCLINIC ZONE
WILL SET UP ACROSS THE UPPER LAKES BTWN THE LATE SEASON COLD AIR
EXPANDING ACROSS SE CANADA AND WARM AIR SPREADING ACROSS THE PLAINS
AHEAD OF A SRN STREAM SHORTWAVE LIFTING OUT OF A MEAN TROF OVER THE
CNTRL/SRN ROCKIES. THIS BAROCLINIC ZONE WILL SET THE STAGE FOR
ACTIVE WEATHER AND POTENTIAL OF MDT TO EVEN HVY PCPN AMOUNTS IN THE
SUN/MON TIME FRAME. GIVEN THE PROXIMITY OF THE COLD AIR...IT`S NOT
OUT OF THE QUESTION THAT ACCUMULATING WET SNOW COULD ALSO OCCUR IN
SOME AREAS OF UPPER MI. LATER NEXT WEEK...THE HEIGHT ANOMALIES WILL
WEAKEN...BUT THE TROF WILL REMAIN IN SE CANADA...RESULTING IN A
CONTINUED BLO NORMAL TEMP REGIME LIKELY PERSISTING FOR UPPER MI THRU
THE ENTIRE WEEK. AFTER THE SUN/MON PCPN...ANOTHER OPPORTUNITY OF
PCPN MAY OCCUR WED/THU IF THE NEXT SHORTWAVE LIFTING OUT OF THE MEAN
ROCKIES TROF MOVES FAR ENOUGH NE TO AFFECT THE UPPER LAKES. DRY
WEATHER SHOULD THEN ROUND OUT THE WEEK. LOOKING FARTHER AHEAD...
NAEFS OUTLOOKS IN THE 8-14DAY PERIOD (APR30-MAY7) INDICATE TEMPS
OVERALL CLOSE TO NORMAL FOR UPPER MI.
BEGINNING SAT NIGHT...-RA WILL DEVELOP/SPREAD INTO THE FCST AREA
WITHIN SHARPENING BAROCLINIC ZONE...LOW-MID LEVEL FGEN...UPPER
DIVERGENCE IN RRQ OF 120KT UPPER JET ACROSS NRN ONTARIO/SRN QUEBEC
AND STRENGTHENING ISENTROPIC ASCENT. WILL CARRY HIGHER CATEGORICAL
POPS INTO ROUGHLY THE FAR HALF IN THE 06Z-12Z PERIOD.
SUN/MON...PCPN GENERATION IN THE BAROCLINIC ZONE WILL CONTINUE TO BE
MAINTAINED BY LOW-MID LEVEL FGEN AND THE RIGHT ENTRANCE OF UPPER JET
ACROSS NRN ONTARIO/SRN QUEBEC. IN ADDITION...SHORTWAVE ENERGY
EJECTING FROM THE CNTRL/SRN ROCKIES INTO THE UPPER MISSISSIPPI
VALLEY...THOUGH WEAKENING...WILL FURTHER AID THE PCPN. WITH
PRECIPITABLE WATER OF 0.75 TO A LITTLE OVER 1 INCH...ROUGHLY 200-
250PCT OF NORMAL...POTENTIAL WILL BE THERE FOR MDT TO EVEN LOCALLY
HVY PCPN AMOUNTS. THIS FCST WILL SHOW TOTAL QPF SAT NIGHT TO MON
EVENING RANGING FROM AROUND ONE-THIRD OF AN INCH OVER THE NRN
KEWEENAW PENINSULA TO AROUND 2 INCHES ALONG THE WI/MI BORDER INTO
SCNTRL UPPER MI. MODELS HAVE NOT BE VERY CONSISTENT ON THERMAL
FIELDS AND POTENTIAL FOR ACCUMULATING SNOW. ABOUT ALL THAT CAN BE
SAID AT THIS POINT IS THAT THERE IS SOME POTENTIAL FOR ACCUMULATING
WET/HVY SNOW OVER PARTS OF UPPER MI...MAINLY THE HIGHER TERRAIN OF
THE W HALF LATE SUN NIGHT/MON MORNING.
PCPN SHOULD DIMINISH/END W TO E MON NIGHT AS WEAKENING SHORTWAVE
ENERGY LIFTING INTO THE UPPER MISSISSIPPI VALLEY MON SHIFTS E ACROSS
THE GREAT LAKES REGION. WILL IGNORE THE CANADIAN MODEL WHICH IS AN
OUTLIER IN BEING MUCH SLOWER TO SHIFT THE SHORTWAVE E...RESULTING IN
PCPN (RAIN/SNOW) LINGERING INTO TUE AFTN.
SKIES WILL CLEAR OUT FOR TUE. IN FACT...WITH GFS FCST SOUNDINGS
SHOWING A DEEP DRY AIR MASS...SHOULD SEE ABUNDANT SUNSHINE. DESPITE
THE SUN...IT WILL BE CHILLY UNDER 850MB TEMPS OF -2 TO -4C AT
MIDDAY. IN ADDITION...CHILL WILL BE AIDED BY A GRADIENT NE WIND TO
START THE DAY AND THEN MESO HIGH DEVELOPING OVER LAKE SUPERIOR IN
THE AFTN MAINTAINING LAKE COOLING.
WED/THU...ATTENTION SHIFTS TO THE NEXT CLUSTER OF SHORTWAVE ENERGY
THAT SETTLED INTO THE MEAN CNTRL/SRN ROCKIES TROF MON/TUE. MUCH WILL
DEPEND ON THE STRENGTH OF THE CONTINUED SE CANADA TROF WHICH WILL BE
EVOLVING INTO A MID LEVEL LOW. IF ITS INFLUENCE REMAINS STRONGER
FARTHER S...THE EJECTING ENERGY WILL BE SUPPRESSED S OF THE AREA...
KEEPING UPPER MI UNDER DRY WEATHER...SIMILAR TO RECENT GFS RUNS AND
THE 12Z CANADIAN. IF THE TROF/CLOSED LOW IN SE CANADA IS
WEAKER/FARTHER N...THE EJECTING ENERGY WILL LIFT FARTHER TO THE NE
AND BRING MORE RAIN INTO UPPER MI...SIMILAR TO RECENT ECMWF RUNS.
HOWEVER...THE 12Z ECMWF HAS STARTED TO BACK AWAY FROM ITS MORE
AGGRESSIVE NE PUSH OF PCPN. FOR NOW...FCST WILL UTILIZE A CONSENSUS
APPROACH WHICH RESULTS IN MOSTLY SCHC POPS WED/THU.
DRY WEATHER WILL THEN ROUND OUT THE WEEK AS HIGH PRES BUILDS SE INTO
THE GREAT LAKES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 130 AM EDT SAT APR 23 2016
VFR CONDITIONS WILL CONTINUE FOR THE ENTIRE FORECAST PERIOD. LIGHT
RAIN WILL MOVE IN FOR SAT EVENING AND WILL START TO LOWER CLOUD
HEIGHTS THEN.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 309 PM EDT FRI APR 22 2016
HIGH PRES WILL MOVE ACROSS LAKE SUPERIOR TONIGHT WITH WINDS
DIMINISHING TO 15 KNOTS OE LESS INTO SAT. AS THE HIGH EXITS TO THE
EASTERN SEABOARD AND LOW PRESSURE DEVELOPS OVER THE PLAINS ON
SUNDAY, NORTHEAST WINDS WILL INCREASE TO 20-30 KTS SUNDAY INTO
MONDAY. THE STRONGEST WINDS WILL BE OVER WESTERN LAKE SUPERIOR WHERE
WINDS MAY APPROACH GALES AT TIMES. WINDS DIMINISH TO LESS THAN 20
KTS MONDAY NIGHT INTO WEDNESDAY AS HIGH PRESSURE MOVES BACK ACROSS
THE REGION.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...ROLFSON
AVIATION...07
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
320 AM CDT SAT APR 23 2016
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 320 AM CDT SAT APR 23 2016
THE PRIMARY FCST CONCERNS CONTINUE TO BE TSTM CHANCES FROM TONIGHT
INTO MONDAY AND TEMPS.
UPPER AIR CHARTS FROM LAST EVENING HAD THE FOLLOWING FEATURES OF
INTEREST. AT 850 MB...A RIDGE WAS IN PLACE FROM TX INTO MN. MOISTURE
AT THIS LEVEL WAS MAINLY CONFINED TO SOUTH TEXAS AND THE GULF
COASTAL REGION. A RIDGE WAS ALSO IN ABOUT THE SAME AREA AT 700 MB
...WITH A TROUGH TO THE WEST. AT 500 MB...A TROUGH WAS OVER THE
WRN UNITED STATES...WITH 12 HOUR HEIGHT FALLS OF UP TO 90 METERS
AT KOAK IN CA. A JET MAX OF AROUND 110 KTS WAS STILL OUT OVER THE
PACIFIC AT 300 MB...ON THE BACKSIDE OF THE TROUGH. LATEST WATER
VAPOR AND IR STLT IMAGERY SHOWED JUST SOME CIRRUS LOCALLY...WITH
AREAS OF FOG TO THE EAST IN IA AND THICKER MID LEVEL CLOUDS OVER
THE ROCKIES. AT THE SFC...A RIDGE WAS TO OUR EAST AND A TROUGH TO
THE WEST...FROM ERN MT INTO ERN CO. S OR SE WINDS WERE NOTED WITH
DEWPOINTS IN THE 40S. THE KOAX SOUNDING FROM LAST EVENING ONLY HAD
ABOUT 0.33 PW. THERE WAS SOME BETTER MOISTURE TO OUR S.
TODAY...WILL PROBABLY KEEP THE FCST DRY. THE 00Z NAM AND EVEN SOME
RECENT RAP MODEL RUNS TRIED TO DVLP ISOLD LGT PCPN OVER PARTS OF
THE AREA THIS MORNING. 06Z NAM AND MOST OF THE RECENT EXPERIMENTAL
HRRR RUNS DID NOT SHOW ANY PCPN. AS THE PRES GRADIENT TIGHTENS
TODAY...IT WILL BECOME BREEZY OR WINDY. PREVIOUS FCST HIGHS LOOKED
PRETTY GOOD...MAINLY 75 TO 80...SO CHANGES WERE MINOR.
PCPN CHANCES WILL BE INCREASING TONIGHT. GENLY FELT THAT MUCH OF
THE EVENING WOULD BE DRY...DESPITE SOME PCPN SHOWN BY THE GFS.
OTHER MODELS KEEP BEST PCPN CHANCES W OF OUR AREA UNTIL AFTER
MIDNIGHT. POPS MAINLY FROM 20-30 PCT SEEM PRUDENT BASED ON THE
MOISTURE RETURN AND FORCING. TREND SHOULD BE FOR PCPN TO TRY TO
DIE OUT SUN MORNING...THEN REDEVELOP IN THE AFTN. THERE IS FAIRLY
GOOD MODEL AGREEMENT ON THAT. SPC DAY 2 OTLK SHOWS SLGT CHANCE OF
SVR AND BASED ON INSTABILITY AND SHEAR FCSTS...THAT LOOKS RIGHT.
BOUNDARY LAYER CAPE VALUES UP TO ABOUT 1500 J/KG SEEM PSBL. THE
HIGHEST TSTM CHANCES WILL BE ACRS ABOUT THE SERN 1/2 OF THE FCST
AREA. LOOK FOR LOWS TNGT 55 TO 60 AND HIGHS SUN MOSTLY MID OR
UPPER 70S.
A FRONT WILL MOVE DOWN THROUGH THE AREA MON...BUT LIFT LOOKS WEAK
SO HAVE KEPT POPS BELOW 15 PCT FOR NOW.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 320 AM CDT SAT APR 23 2016
WEAK HIGH PRES SHOULD BE OVER THE AREA MON NGT...WITH CONTINUED
DRY WEATHER. BUT...A CLOSED LOW WILL BE ORGANIZING TO OUR W/SW
MOST LIKELY OVER UT OR NRN AZ. THAT SHOULD MOVE OUT TO WRN KS BY
12Z WED...THEN PROBABLY INTO IA BY 12Z THU. YET ANOTHER CLOSED LOW
IS EXPECTED TO BE OVER SRN CA BY THU MORNING. MODEL AGREEMENT IS
NOT OVERLY GREAT BY FRI...BUT THE GENERAL CONSENSUS IS THAT THE
LOW WILL PROBABLY OPEN UP AND MOVE OUT INTO THE HIGH PLAINS BY THE
WEEKEND.
THE 00Z GFS WAS SLOWER BRINGING A CHANCE OF SHRA/TSTMS BACK TO THE
AREA ON TUE COMPARED TO THE ECMWF. GAVE BOTH MODELS EQUAL WEIGHT
FOR NOW. PCPN SHOULD BE FAIRLY WIDESPREAD TUE NGT/WED...WHICH MAY
HELP LIMIT STRONG STORM COVERAGE. CURRENT EXPECTED TIMING DRIES
THE AREA OUT FOR THE PD FROM THU INTO FRI MORNING...THEN PCPN IS
LIKELY TO RETURN.
&&
.AVIATION...(06Z TAFS FOR KOMA...KLNK...KOFK THROUGH 06Z SUNDAY)
ISSUED AT 1136 PM CDT FRI APR 22 2016
SOME MVFR CLOUDS ARE DEVELOPING ABOUT 40 MILES EAST OF KOMA. DON`T
BELIEVE THEY WILL DEVELOP WESTWARD INTO OMAHA. A COUPLE OF MODELS
ALSO DEVELOP SOME MVFR FOG AT KOMA LATER TONIGHT AS WELL.
OTHERWISE...VFR CONDITIONS...WITH SOUTHEAST WINDS INCREASING TO 19
TO 32 KNOTS BY 14-17Z.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...MILLER
LONG TERM...MILLER
AVIATION...DEWALD
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
220 AM PDT SAT APR 23 2016
.SYNOPSIS...AS ONE SYSTEM MOVES OUT OF THE REGION TODAY ANOTHER
SYSTEM WILL MOVE INTO THE WEST COAST SUNDAY AND MONDAY. THIS WILL
BRING ANOTHER ROUND OF GUSTY WINDS ALONG WITH A CHANCE OF SHOWERS TO
MUCH OF THE REGION. TEMPERATURES LOOK TO REMAIN BELOW NORMAL THROUGH
MUCH OF NEXT WEEK.
&&
.SHORT TERM...THROUGH MONDAY NIGHT.
WINDS HAVE BEEN ON THE DECREASE OVER MUCH OF THE REGION EARLY THIS
MORNING...BUT THERE ARE STILL A FEW DOWNSLOPE PRONE AREAS WEST OF
THE SPRING MOUNTAINS THAT ARE SEEING GUSTS INTO ADVISORY LEVELS.
HIRES MODELS DO INDICATE A RAPID DECREASE IN THE STRONGER WINDS
AFTER 10Z SO THE WIND ADVISORY SHOULD EXPIRE ON TIME. THE UPPER LOW
RESPONSIBLE FOR THE WIND AND PRECIPITATION WILL MOVE NORTHEAST TODAY
AND IS EXPECTED TO BE OVER NORTHERN UTAH BY MID DAY TODAY. THERE
STILL LOOKS TO BE SOME RESIDUAL SHOWERS ACROSS NORTHERN LINCOLN
COUNTY...BUT ANYTHING THAT DOES FALL IS EXPECTED TO REMAIN LIGHT AND
SHOULD BE OUT OF THE AREA BY LATE THIS AFTERNOON.
SHORT LIVED AND WEAK HIGH PRESSURE WILL MOVE OVER THE REGION LATE
THIS AFTERNOON INTO EARLY SUNDAY BEFORE THE EFFECTS OF THE NEXT
TROUGH MOVES INTO THE WEST COAST. WE WILL START TO SEE INCREASING
SOUTHWEST WINDS AGAIN SUNDAY AFTERNOON...BUT AT THIS TIME WIND
SPEEDS LOOK TO REMAIN BELOW ADVISORY LEVELS. PRECIPITATION WILL
SPREAD INTO THE SIERRA AND THEN ACROSS THE NORTHERN ZONES SUNDAY
NIGHT. THE BIGGER CHANGES WILL OCCUR MONDAY AS THE MODELS INDICATE A
COLD CLOSED LOW DROPPING SOUTH THROUGH NORTHERN CALIFORNIA AND
WESTERN NEVADA. THIS IS EXPECTED TO BRING MUCH COOLER TEMPERATURES
TO THE REGION ALONG WITH A BETTER CHANCE OF PRECIPITATION TO MUCH OF
THE AREA. THIS SYSTEM DOES NOT HAVE A SIGNIFICANT MOISTURE TAP SO
MAJORITY OF THE PRECIPITATION WILL REMAIN LIGHT...WITH THE EXCEPTION
OF CENTRAL NYE AND LINCOLN COUNTY WHERE MORE WIDESPREAD
PRECIPITATION COULD OCCUR. SNOW LEVELS ARE EXPECTED BE BETWEEN 5000-
6000 FEET...BUT AT THIS TIME SNOW AMOUNTS SHOULD NOT EXCEED ADVISORY
LEVELS. TEMPERATURES WILL DROP ABOUT 10 DEGREES FROM SUNDAYS HIGHS
AND BE AROUND 10 DEGREES BELOW NORMAL. DEPENDING ON WHERE THE UPPER
LOW SETS UP WE COULD SEE A BAND OF STRONGER WINDS ACROSS SAN
BERNARDINO AND SOUTHERN MOHAVE COUNTIES MONDAY AFTERNOON WITH
ADVISORY LEVEL WINDS POSSIBLE.
.LONG TERM...TUESDAY THROUGH FRIDAY.
NOT TOO MUCH CHANGE OVERALL IN THE MODEL SOLUTIONS THIS MORNING AS
COMPARED TO YESTERDAY...WITH ONLY A COUPLE OF TIMING DIFFERENCES.
ACTIVE PATTERN PERSISTS WITH MULTIPLE STORM SYSTEMS PASSING THROUGH
DURING THE PERIOD. PICKING UP TUESDAY MORNING...LOW PRESSURE WHICH
PASSED THROUGH ON MONDAY SHOULD BE MOVING AWAY TO THE EAST. ONE
TIMING DIFFERENCE IS THAT THE MODELS /ESPECIALLY THE GFS/ ARE A BIT
SLOWER WITH THIS SYSTEM THAN YESTERDAY...SUGGESTING THAT PRECIP
CHANCES MAY LINGER INTO TUESDAY OVER LINCOLN COUNTY. TEMPERATURES
WILL BE ABOUT TEN DEGREES BELOW NORMAL TUESDAY IN THE WAKE OF THE
STORM. THE NEXT STORM WILL BE NEAR THE CALIFORNIA COAST BY WEDNESDAY
AFTERNOON...WITH CLOUDS INCREASING AGAIN AREAWIDE AND PRECIP CHANCES
BEGINNING IN THE SIERRA AND SOUTHERN GREAT BASIN. TEMPERATURES WILL
COME UP A FEW DEGREES FROM TUESDAY IN THE SOUTHERN GREAT BASIN AND
SEVERAL DEGREES IN THE MOJAVE DESERT...BUT REMAIN BELOW NORMAL
PRETTY MUCH AREAWIDE. AS THIS STORM ROLLS INTO THE MOJAVE DESERT
THURSDAY...PRECIP CHANCES WILL INCREASE AREAWIDE AND TEMPERATURES
WILL COME BACK DOWN A FEW DEGREES. ANOTHER TIMING DIFFERENCE FROM
YESTERDAY IS THAT THE MODELS ARE SLOWER TO EJECT THIS SYSTEM TO THE
EAST...SUGGESTING THAT PRECIP CHANCES COULD LINGER INTO FRIDAY.
TEMPERATURES MAY ALSO BE SLOW TO RECOVER ON FRIDAY IF THE STORM
HANGS AROUND. ALL IN ALL...AN ACTIVE WEEK AHEAD WITH TEMPERATURES
SOLIDLY BELOW NORMAL FOR MUCH OF THE PERIOD.
&&
.AVIATION...FOR MCCARRAN...WINDS ARE EXPECTED TO SHIFT TO THE
NORTHWEST THIS MORNING WITH SPEEDS GENERALLY BETWEEN 10-15KTS THERE
COULD STILL BE A GUST OR TWO TO AROUND 20KTS...BUT THE MORE
FAVORABLE TIMEFRAME FOR GUSTS WOULD BE IN THE MORNING. WINDS ARE
FORECAST TO SHIFT BACK TO THE SOUTHWEST AFTERNOON SUNSET THIS
EVENING WITH SPEEDS AROUND 6-8KTS. FEW-SCT MID AND HIGH CLOUDS
EXPECTED THROUGH THE PERIOD.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...COLD FRONT WILL MOVE THROUGH THE REGION EARLY THIS
MORNING WITH WINDS GRADUALLY SHIFTING TO THE NORTHWEST AFTER 12Z FOR
AREAS SOUTH OF A DAG-IFP-IGM LINE. WINDS BEHIND THE FRONT ARE
FORECAST TO BECOME NORTHWEST WITH SPEEDS BETWEEN 10-15KTS. SOME
GUSTS UP TO 20KTS ARE POSSIBLE THIS MORNING AND ESPECIALLY DOWN THE
COLORADO RIVER THROUGH THE DAY. ISOLD-SCT RAIN/SNOW SHOWERS ACROSS
NORTHERN LINCOLN COUNTY THROUGH THIS AFTERNOON.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTERS SHOULD REPORT ANY
SIGNIFICANT WEATHER ACCORDING TO STANDARD OPERATING PROCEDURES.
$$
SHORT TERM/AVIATION...GORELOW
LONG TERM.... MORGAN
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
[top]
Area Forecast Discussion...UPDATED
National Weather Service Reno NV
1022 PM PDT FRI APR 22 2016
.UPDATE...
Latest radar trends show a rapid decrease in both intensity and
coverage of snow showers as instability/convection decrease across
the interior valleys of northern CA. The upper level shortwave
will exit late tonight with drier and more stable airmass to bring
an end to showers Saturday. Temperatures will remain below
freezing overnight where snow fell today. Therefore roads will see
little improvement until treated. The snow advisory will expire at
11 pm. However, anyone planning travel during the overnight hours
should check the latest road conditions.
&&
.SYNOPSIS...
A break in the wet weather is expected Saturday before more
showers arrive Sunday into Monday. Unsettled weather will continue
through next week with below average temperatures.
&&
.PREVIOUS DISCUSSION... /Issued 736 PM PDT FRI APR 22 2016/
UPDATE...
The cold front has moved completely through western NV as of early
this evening and gradients have relaxed enough to go ahead and
drop the wind advisories and areas of blowing dust. Winds will
still be locally gusty before subsiding further this evening, but
well below earlier peaks.
Convection continues to fire over the Sacramento Valley and then
move eastward into the Tahoe Basin. Moderate to heavy snow was
falling under some of the stronger showers with roads likely to
remain a mess this evening, especially with the sun setting.
Expect another 1 to 3 inches, locally up to 4 inches this evening
before showers begin to diminish. We will continue the snow
advisory through expiration. Scattered snow showers may also
produce periods of slick roads along Hwy 395 through Mono County.
Make sure to check road conditions if you must travel tonight.
Hohmann
SYNOPSIS...
Moderate to occasionally heavy bands of snow showers will continue
across the Tahoe Basin through this evening with showers more
scattered elsewhere tonight. A break is expected Saturday before
more showers arrive Sunday into Monday. Unsettled weather will
continue through next week with below average temperatures.
PREVIOUS DISCUSSION... /Issued 303 PM PDT FRI APR 22 2016/
SYNOPSIS...
A strong Pacific storm will continue to move through the Sierra
and Western Nevada tonight. Rain and heavy mountain snow are
expected this evening near and south of I-80. A break is expected
Saturday before more showers are expected Sunday into Monday with
another system. Unsettled weather will continue through next week
with below average temperatures.
SHORT TERM...
A strong spring storm continues to move through. Heavy snow is
falling in the Sierra with rates approaching 3"/hr. It is best to
avoid travel in the Sierra for the next few hours if possible.
Heavy convective snowfall continues in the Sierra with the bands
extending from Westwood south into Bridgeport. Heavy snow is
falling above 6000 feet, with the snow level locally down to 4500
feet in the heaviest bands. Latest satellite/radar trends support
the HRRR in keeping the heaviest rain/snow going thru 03Z near and
south of I-80. After there will be a rapid reduction in showers as
the upper forcing moves east and the airmass stabilizes.
Until then, another 6+ inches of snow is possible above 7000 feet
with another 2-4" down to 5500-6000 feet. Rainfall into Western NV
will be heaviest in the Sierra front where an additional 1/4" of
rain is possible. It may mix with snow at times in the foothills
while lighter amounts are expected toward the highway 95 corridor.
Winds are much weaker along the Sierra Front with the precip
falling, but strong gusts continue east of a Bridgeport to
Lovelock line. Will cancel the advisory for Reno-Carson-Minden,
but leave the remainder as the winds continue there.
Behind this storm, a break is expected Saturday with continued
cool temps, but lighter winds and dry conditions. Another upper
low is expected Sunday afternoon into Monday. Showers are expected
Sunday afternoon with enough instability for a few thunderstorms
as well. The core of the low will move overhead Monday morning
with much colder air. Snow levels will fall to near the valley
floors. While this storm will have some moisture with it, the best
forcing is expected to remain over Eastern NV so we are not
expecting another big precip event. However, there remains a
threat (low at this time) of some light snowfall during the Monday
morning commute along the I-80 and highway 50 corridors. Wallmann
LONG TERM...Monday Night through Friday...
Unsettled weather pattern is expected to continue through next
week as late season storm systems line up to move into the West
Coast. Wednesday-Friday could be a rather wet period for much of
the region with potential for additional snow in higher
elevations.
For Monday night, the first upper low is likely to be on its way
out with lingering rain and snow showers diminishing. Tuesday
still looks like the least active weather day, although a few
showers remain possible as residual moisture will remain in place.
Even though temperatures are expected to increase about 10-15
degrees from Monday, highs in the lower 60s and around 50 degrees
near the Sierra will still be a few degrees below average for late
April.
For next Wednesday-Friday, medium range guidance continues to
indicate a potent low pressure tracking southward along the
California coast, then swing inland across the southwest US (or
possibly farther north into eastern NV). Despite this southerly
track, a broad area of upper divergence and instability is
projected to set up over the Sierra and western NV, along with a
decent tap of Pacific moisture. A few thunderstorms are also
possible each afternoon, although the better instability looks to
be trending north of I-80 by next Friday. Current projections
favor the best overall rain and snow chances Wednesday night and
higher thunderstorm potential on Thursday, but this could vary
depending on the eventual storm track. Widespread cloud cover will
keep daytime temps a few degrees below average each day, with
nighttime temps slightly above average. Early snow level
projections generally range from 6000-7000 feet in the Sierra,
although these snow levels could occasionally drop several hundred
feet during convection or heavier precip bands. MJD
AVIATION...
The most significant weather effects on aviation will continue
through this evening with IFR/LIFR cigs/vsby in snow near the
Sierra including KTVL/KTRK/KMMH, and a few inches of snow
accumulating on pavement. For lower elevations including KRNO-
KCXP, rain will produce MVFR cigs/vsby with mountain obscurations,
IFR at times during heavier rain bands. The strongest winds have
ended at KRNO-KCXP but some gusts to 35 KT remain possible. KMMH
may receive stronger gusts above 40 KT until 03z.
Later tonight, if cloud cover breaks up sufficiently, areas of
FZFG would develop across many Sierra valleys around Tahoe and
northeast CA, including KTRK. For Saturday, generally VFR
conditions are expected with lighter winds. MJD
&&
.REV Watches/Warnings/Advisories...
NV...None.
CA...None.
&&
$$
For more information from the National Weather Service visit...
http://weather.gov/reno
AREA FORECAST DISCUSSION.
HIGHS TODAY WILL BE MAINLY 50S IN CENTRAL NEW YORK...AND IN THE
UPPER 50S-LOWER 60S ALONG AND ESPECIALLY SOUTH OF THE TWIN TIERS.
LOWER ELEVATIONS OF PIKE-SULLIVAN COUNTIES MAY EVEN GET INTO THE
MIDDLE 60S.
HIGH PRESSURE MOVES OVERHEAD TONIGHT...DECOUPLING WIND AND SETTING
UP GOOD RADIATIONAL COOLING CONDITIONS. LOWS WILL REACH TO AROUND
FREEZING PLUS OR MINUS A FEW DEGREES.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
345 AM UPDATE...
HIGH PRESSURE LARGE-AND-IN-CHARGE SUNDAY...THEN A WEST-TO-EAST FRONTAL
ZONE WILL SET UP OVER THE REGION WITH INCREASING CHANCES OF
SHOWERS.
FULL SUNSHINE IS EXPECTED SUNDAY...WITH VERY LIGHT WINDS YET ALSO
EVEN LOWER RELATIVE HUMIDITY VALUES. ONCE AGAIN...DEWPOINTS
NEEDED TO BE LOWBALLED VERSUS MODEL GUIDANCE...WITH THE VERY DRY
AIR ABOVE THE BOUNDARY LAYER WHICH WILL MIX DOWN DURING PEAK
HEATING. TEMPERATURES WILL MODERATE TO RIGHT AROUND CLIMATOLOGY
FOR HIGHS...UPPER 50S TO MID 60S.
HIGH PRESSURE WILL THEN SHIFT INTO THE ATLANTIC...MAKING ROOM FOR
THE DEVELOPMENT OF A WEST-TO-EAST FRONTAL ZONE OVER THE
REGION...UNDER BRISK ZONAL FLOW ALOFT. MOISTURE WILL AT FIRST
FOCUS NORTH OF THE AREA BUT WITH TIME WILL SAG SOUTHWARD TO
INCLUDE OUR REGION. INITIAL CHANCES OF SHOWERS WILL BE FAIRLY LOW
LATE SUNDAY NIGHT-MONDAY MORNING...AND MAINLY IN CENTRAL NEW YORK.
THEN ONE OR POSSIBLY TWO WAVES OF LOW PRESSURE AND ASSOCIATED
SHORTWAVES...WILL MOVE THROUGH THE FRONTAL ZONE MONDAY AFTERNOON
THROUGH ESPECIALLY MONDAY NIGHT-TUESDAY...LEADING TO A BETTER
LIKELIHOOD OF SHOWERS DURING THAT TIME. RAIN AMOUNTS DO NOT LOOK
OVERWHELMING...BUT SHOULD PROBABLY ENOUGH TO BE CONSIDERED A
WETTING RAIN FOR FIRE WEATHER CONCERNS...WHICH WOULD BE WELCOME.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
LONG TERM FORECAST CONCERNS NEXT WEEK ARE CENTERED AROUND THE
PASSAGE OF A SLOW MOVING COLD FRONT MONDAY AND TUESDAY WITH RAIN
SHOWERS. THERE IS ANOTHER WEAK COLD FRONT EXPECTED TO PUSH
THROUGH ON THURSDAY AND FRIDAY WITH MORE RAIN. IN BETWEEN THESE
TWO SYSTEMS DURING THE MIDDLE OF THE WEEK AN AREA OF HIGH PRESSURE
WILL BRING A BRIEF RESPITE TO THE REGION WITH DRY WEATHER AND
SLIGHTLY WARMER TEMPERATURES.
&&
.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
CAA BHD THE COLD FNT WILL DVLP SOME LOW CLD CIGS DURING THE
OVERNIGHT BRING IFR AND MVFR CONDS TO THE AREA. DRIER AIR BEGINS
TO WRK IN AFT SUNRISE LFTG THE CIGS TO VFR AND EVENTUALLY
RESULTING IN CLR SKIES. NLY WINDS WILL BECOME GUSTY AFT SUNRISE
WITH MIXING...AND BECOME LGTR AGAIN AFT SUNSET THIS EVE.
.OUTLOOK...
SAT NGT TO SUN EVE...VFR.
SUN OVERNIGHT TO TUE...OCCASIONAL SHOWERS. CHANCE FLIGHT RESTRICTIONS.
WED...BECOMING VFR.
&&
.FIRE WEATHER...
A FRONT JUST WENT THROUGH THE REGION BUT ONLY PRODUCED A WETTING
RAIN FOR SOME AREAS. BEHIND THE FRONT...NORTH-NORTHWEST WINDS WILL
PICK UP TO 10-15 MPH WITH GUSTS AROUND 25 MPH AT TIMES. MUCH DRIER
AIR WILL ALSO MOVE INTO THE REGION...ALLOWING RELATIVE HUMIDITY TO
PLUMMET INTO THE 25 TO 35 PERCENT RANGE LATE THIS AFTERNOON. FOR
LOCATIONS THAT DID NOT GET A WETTING RAIN...THIS MAY CONTRIBUTE TO
FIRE ACTIVITY. LOOKING AHEAD...WINDS WILL BE MUCH LIGHTER
SUNDAY...BUT HUMIDITY LEVELS ARE LIKELY TO BE EVEN LOWER. OUR NEXT
GOOD CHANCE FOR A WETTING RAIN WILL BE LATE MONDAY INTO TUESDAY.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MDP
NEAR TERM...MDP
SHORT TERM...MDP
LONG TERM...BJT
AVIATION...DGM
FIRE WEATHER...MDP
AREA FORECAST DISCUSSION
NWS RALEIGH NC
309 AM EDT SAT APR 23 2016
.SYNOPSIS...A WEAK COLD FRONT WILL EXIT CENTRAL NC THIS
MORNING. A SECONDARY COLD FRONT WILL DROP SOUTHEAST THROUGH THE AREA
THIS EVENING...FOLLOWED BY HIGH PRESSURE WHICH WILL BUILD
INTO THE REGION SUNDAY THROUGH MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 950 PM FRIDAY...
THE UPPER TROUGH AXIS AND SYNOPTIC COLD FRONT REMAIN JUST WEST OF
THE MOUNTAINS THIS EVENING...WHILE THE DOWNSTREAM CLUSTERS OF
SHOWERS AND ISOLATED STORMS HAVE BECOME MOSTLY CONFINED TO ONE
COMMON CONVERGENCE AXIS IN THE COASTAL PLAIN...EAST OF THE RAH CWA.
MOISTURE TRANSPORT REMAINS GREATEST OVER EASTERN NC...WATER VAPOR
IMAGERY STILL SUGGESTS A COUPLE DISTURBANCES ALOFT THAT WILL TRACK
NORTHEAST ACROSS NC THIS EVENING. THE MORE NOTABLE DISTURBANCES
IS CURRENTLY MOVING OVER EAST-CENTRAL SC AND WILL LIKELY CAUSE
SHOWERS TO EXPAND A LITTLE BACK TO THE WEST TOWARD THE I-95 CORRIDOR
AS THEY MOVE THROUGH THE NC COASTAL PLAIN IN THE NEXT FEW HOURS.
LATEST HRRR ITERATIONS SHOW THIS AS THE LAST REAL GASP OF
PRECIP...WITH JUST A FEW ISOLATED SHOWERS NEAR THE COLD FRONT AS IT
MOVES INTO THE MORE STABLE AIRMASS OVER THE PIEDMONT LATER TONIGHT.
AM ISOLATED STORM NEAR OR EAST OF I-95 IS STILL POSSIBLE...BUT THE
THREAT OF STRONG UPDRAFTS AND ANY NEAR SEVERE STORMS HAS LIKELY
PASSED.
THE OTHER FORECAST CONCERN OVERNIGHT IS THE POTENTIAL FOR FOG GIVEN
CLEARING ALOFT FROM WEST TO EAST AND THE DELAYED ARRIVAL OF THE COLD
FRONT AND DRIER NORTHWEST FLOW. WHILE THE SIGNAL IS NOT
OVERWHELMINGLY STRONG...RAP AND HRRR SOUNDINGS INDICATE THE FOG
POTENTIAL PRIMARILY IN THE WESTERN PIEDMONT FROM 05Z TO 10Z. TEMPS
SHOULDN`T HAVE MUCH CHANCE TO FALL PRIOR TOT HE COLD FRONT...WITH
LOWS IN THE MID 50S TO LOWER 60S.
&&
.SHORT TERM /SATURDAY AND SUNDAY NIGHT/...
AS OF 235 PM FRIDAY...
THE INITIAL COLD FRONT SHOULD HAVE MOVED TO COASTAL NC BY DAYBREAK
SAT. AREAS OF LOW CLOUDS AND PATCHY FOG IN THE MORNING SHOULD BURN
OFF QUICKLY WITH DRY AIR ABOVE IT THROUGH THE MID LEVELS. THE MID
LEVEL SHORTWAVE TROUGH AXIS WILL BE SITUATED OVERHEAD THROUGH
CENTRAL VA AND CENTRAL NC AND WILL MOVE SLOWLY ESE THROUGH THE
DAY... BRINGING A POCKET OF HIGHER MID LEVEL LAPSE RATES (AOA 6.0
C/KM) ACROSS THE AREA... REACHING THE ERN FORECAST AREA DURING PEAK
HEATING. WHILE ANY MOISTURE WILL BE SHALLOW... THE POSSIBILITY OF
MINOR INSTABILITY WITH THE ATTENDANT DPVA AND POCKET OF COOLER AIR
ALOFT COULD STILL SUPPORT ISOLATED TO SCATTERED SHOWERS... MAINLY
FROM THE TRIANGLE NORTH AND EAST IN THE AFTERNOON. ANY ADDITIONAL
RAINFALL AMOUNTS WILL BE SMALL. OTHERWISE... EXPECT PARTLY TO MOSTLY
SUNNY SKIES. THIS INITIAL FRONT WILL NOT HAVE A LOT OF COOL AIR
RIGHT BEHIND IT... AS THICKNESSES DROP ONLY SLIGHTLY AND REMAIN
ABOVE NORMAL. EXPECT HIGHS IN THE MID 70S TO NEAR 80. THE SECONDARY
AND MORE SUBSTANTIAL COLD FRONT DROPS SE THROUGH THE AREA SAT
EVENING... WITH SURFACE WINDS SHIFTING FROM NNW TO NE AND A COOLER
RIDGE BUILDING IN FROM THE NORTH. SHOULD SEE MOSTLY CLEAR SKIES SAT
NIGHT... ALTHOUGH SCATTERED STRATOCU ARE POSSIBLE NEAR 4-6 KFT AGL
AS THE 850 MB ANTICYCLONE MOVES IN FROM THE WEST YIELDING A POOLING
OF MOISTURE AT THAT LEVEL OVERNIGHT. THICKNESS DROP BACK DOWN NEAR
OR JUST BELOW NORMAL WITH THE FRONTAL PASSAGE... SUPPORTING LOWS IN
THE LOWER TO MID 50S. -GIH
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 305 AM SATURDAY...
MONDAY THROUGH TUESDAY: MID LEVEL S/W RIDGING TO START THE PERIOD
WILL DAMPEN AS A MID LEVEL S/W TRACKS FROM THE GREAT LAKES TO THE
NORTHEAST U.S. EARLY NEXT WEEK... HELPING TO SEND A BACK DOOR COLD
FRONT TOWARDS THE AREA. THE FRONT WILL REMAIN NORTH OF CENTRAL NC
THROUGH TUESDAY. THUS... EXPECT DRY CONDITIONS OUTSIDE OF A VERY
SMALL CHANCE FOR SOME SHOWERS AND STORMS LATE IN THE DAY ON TUESDAY
ACROSS THE FAR NORTH NEAR THE VA/NC BORDER. WITH SURFACE HIGH
LOCATED OFFSHORE THIS SHOULD ALLOW FOR A WARMING SOUTHWESTERLY
RETURN FLOW... YIELDING HIGHS IN THE LOWER 80S MONDAY TO THE MID TO
UPPER 80S ON TUESDAY. LOWS TEMPS TUESDAY MORNING ARE EXPECTED TO BE
AROUND 60.
TUESDAY NIGHT THROUGH FRIDAY: MEDIUM RANGE MODELS CONTINUE TO
STRUGGLE WITH HOW FAR SOUTH THE AFOREMENTIONED BACKDOOR COLD FRONT
MAKES IT. HOWEVER... THE TREND HAS BEEN TO PUSH THE FRONT FURTHER
SOUTHWARD AND INTO CENTRAL NC BY TUESDAY NIGHT INTO WEDNESDAY...
WITH THE GFS NOW PUSHING THE FRONT WELL TO THE SOUTH OF THE AREA.
THUS... WEDNESDAY HIGH TEMPS FORECAST HAS A HIGH BUST POTENTIAL. THE
RAW GFS TEMPS HAVE HIGHS IN THE UPPER 50S TO MID 60S ON WEDNESDAY...
WHILE THE ECMWF IS CLOSER TO WPC VALUES... HIGHS RANGING FROM THE
MID 70S NE TO THE MID TO UPPER 80S SW. FOR NOW WILL STICK CLOSE TO
WPC AND SHOW THE FRONT STALLING ACROSS THE AREA ON WEDNESDAY... WITH
THE POTENTIAL FOR SOME SHOWERS AND STORMS (SLIGHT CHANCE TO LOW END
CHANCE).
CONFIDENCE DECREASES FURTHER THURSDAY INTO FRIDAY. AS THE NEXT IN A
PARADE OF S/W DISTURBANCE TRACKS FROM THE WESTERN U.S... STARTING
OUT AS A DEEP MID/UPPER LEVEL LOW/TROUGH.... THEN OPENING/WEAKENING
SOME AS IT SHIFTS EASTWARD. HOWEVER... TIMING OF THIS NEXT
DISTURBANCE AND EVENTUAL TRACK ARE IN GREAT QUESTION AT THIS TIME.
GIVEN WE ARE TALKING ABOUT A SYSTEM THAT IS YET TO BREAK OFF FROM A
DEEP VORTEX NEAR/SOUTH OF ALASKA... WILL KEEP POPS LOW AND TREND THE
TIMING OF THE ASSOCIATED FRONT TOWARDS WPC (LATE WEEK/FRIDAY). TEMPS
WILL BE TRICKY AND LARGELY DRIVEN BY HOW QUICKLY THE PREVIOUS FRONT
DISSIPATES/RETREATS NORTHWARD. FOR NOW WILL GO WITH HIGHS IN THE
LOWER TO MID 80S LATE NEXT WEEK... WITH LOWS GENERALLY IN THE UPPER
50S TO LOWER 60S.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 835 PM FRIDAY...
AREAS OF LIGHT TO BRIEFLY MODERATE RAIN WILL EXIT THE COASTAL PLAIN
COUNTIES PRIOR TO DAYBREAK AS A SFC COLD FRONT CROSSES CENTRAL NC.
IN THE WAKE OF THE RAIN...CEILINGS AND VISIBILITIES WILL LOWER INTO
THE IFR/LIFR CATEGORY. THE VERY POOR AVIATION CONDITIONS EXPECTED
PRIMARILY BETWEEN 09Z-13Z/ AFTER 13Z...CEILINGS AND VISIBILITIES
WILL QUICKLY IMPROVE...LEADING TO VFR CONDITIONS AREAWIDE BY 15Z.
A STEADY NLY WIND AROUND 10KTS WILL DEVELOP AROUND 14Z AND PERSIST
WELL INTO THE AFTERNOON.
WITH HEATING...EXPECT A BROKEN STRATOCU DECK TO FORM WITH CEILINGS
4000-6000FT ANTICIPATED. A FEW SHOWERS MAY ALSO DEVELOP...MAINLY
BETWEEN 19Z SATURDAY-01Z SUNDAY... AND PRIMARILY TO THE NORTH OF
KRDU AND KRWI. THESE SHOWERS WILL BE ALONG/AHEAD OF A SECONDARY
FRONT THAT WILL CROSS OUR REGION EARLY THIS EVENING.
HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT...LEADING TO A PERIOD
OF VFR CONDITIONS WHICH SHOULD LAST UNTIL TUESDAY. AN APPROACHING
FRONT WILL BRING THE NEXT CHANCE FOR SUB VFR CONDITIONS TO CENTRAL
NC TUESDAY NIGHT INTO WEDNESDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...22
SHORT TERM...HARTFIELD
LONG TERM...BSD
AVIATION...WSS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
132 AM EDT SAT APR 23 2016
.SYNOPSIS...A WEAK COLD FRONT WILL EXIT CENTRAL NC THIS
MORNING. A SECONDARY COLD FRONT WILL DROP SOUTHEAST THROUGH THE AREA
THIS EVENING...FOLLOWED BY HIGH PRESSURE WHICH WILL BUILD
INTO THE REGION SUNDAY THROUGH MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 950 PM FRIDAY...
THE UPPER TROUGH AXIS AND SYNOPTIC COLD FRONT REMAIN JUST WEST OF
THE MOUNTAINS THIS EVENING...WHILE THE DOWNSTREAM CLUSTERS OF
SHOWERS AND ISOLATED STORMS HAVE BECOME MOSTLY CONFINED TO ONE
COMMON CONVERGENCE AXIS IN THE COASTAL PLAIN...EAST OF THE RAH CWA.
MOISTURE TRANSPORT REMAINS GREATEST OVER EASTERN NC...WATER VAPOR
IMAGERY STILL SUGGESTS A COUPLE DISTURBANCES ALOFT THAT WILL TRACK
NORTHEAST ACROSS NC THIS EVENING. THE MORE NOTABLE DISTURBANCES
IS CURRENTLY MOVING OVER EAST-CENTRAL SC AND WILL LIKELY CAUSE
SHOWERS TO EXPAND A LITTLE BACK TO THE WEST TOWARD THE I-95 CORRIDOR
AS THEY MOVE THROUGH THE NC COASTAL PLAIN IN THE NEXT FEW HOURS.
LATEST HRRR ITERATIONS SHOW THIS AS THE LAST REAL GASP OF
PRECIP...WITH JUST A FEW ISOLATED SHOWERS NEAR THE COLD FRONT AS IT
MOVES INTO THE MORE STABLE AIRMASS OVER THE PIEDMONT LATER TONIGHT.
AM ISOLATED STORM NEAR OR EAST OF I-95 IS STILL POSSIBLE...BUT THE
THREAT OF STRONG UPDRAFTS AND ANY NEAR SEVERE STORMS HAS LIKELY
PASSED.
THE OTHER FORECAST CONCERN OVERNIGHT IS THE POTENTIAL FOR FOG GIVEN
CLEARING ALOFT FROM WEST TO EAST AND THE DELAYED ARRIVAL OF THE COLD
FRONT AND DRIER NORTHWEST FLOW. WHILE THE SIGNAL IS NOT
OVERWHELMINGLY STRONG...RAP AND HRRR SOUNDINGS INDICATE THE FOG
POTENTIAL PRIMARILY IN THE WESTERN PIEDMONT FROM 05Z TO 10Z. TEMPS
SHOULDN`T HAVE MUCH CHANCE TO FALL PRIOR TOT HE COLD FRONT...WITH
LOWS IN THE MID 50S TO LOWER 60S.
&&
.SHORT TERM /SATURDAY AND SATURDAY NIGHT/...
AS OF 235 PM FRIDAY...
THE INITIAL COLD FRONT SHOULD HAVE MOVED TO COASTAL NC BY DAYBREAK
SAT. AREAS OF LOW CLOUDS AND PATCHY FOG IN THE MORNING SHOULD BURN
OFF QUICKLY WITH DRY AIR ABOVE IT THROUGH THE MID LEVELS. THE MID
LEVEL SHORTWAVE TROUGH AXIS WILL BE SITUATED OVERHEAD THROUGH
CENTRAL VA AND CENTRAL NC AND WILL MOVE SLOWLY ESE THROUGH THE
DAY... BRINGING A POCKET OF HIGHER MID LEVEL LAPSE RATES (AOA 6.0
C/KM) ACROSS THE AREA... REACHING THE ERN FORECAST AREA DURING PEAK
HEATING. WHILE ANY MOISTURE WILL BE SHALLOW... THE POSSIBILITY OF
MINOR INSTABILITY WITH THE ATTENDANT DPVA AND POCKET OF COOLER AIR
ALOFT COULD STILL SUPPORT ISOLATED TO SCATTERED SHOWERS... MAINLY
FROM THE TRIANGLE NORTH AND EAST IN THE AFTERNOON. ANY ADDITIONAL
RAINFALL AMOUNTS WILL BE SMALL. OTHERWISE... EXPECT PARTLY TO MOSTLY
SUNNY SKIES. THIS INITIAL FRONT WILL NOT HAVE A LOT OF COOL AIR
RIGHT BEHIND IT... AS THICKNESSES DROP ONLY SLIGHTLY AND REMAIN
ABOVE NORMAL. EXPECT HIGHS IN THE MID 70S TO NEAR 80. THE SECONDARY
AND MORE SUBSTANTIAL COLD FRONT DROPS SE THROUGH THE AREA SAT
EVENING... WITH SURFACE WINDS SHIFTING FROM NNW TO NE AND A COOLER
RIDGE BUILDING IN FROM THE NORTH. SHOULD SEE MOSTLY CLEAR SKIES SAT
NIGHT... ALTHOUGH SCATTERED STRATOCU ARE POSSIBLE NEAR 4-6 KFT AGL
AS THE 850 MB ANTICYCLONE MOVES IN FROM THE WEST YIELDING A POOLING
OF MOISTURE AT THAT LEVEL OVERNIGHT. THICKNESS DROP BACK DOWN NEAR
OR JUST BELOW NORMAL WITH THE FRONTAL PASSAGE... SUPPORTING LOWS IN
THE LOWER TO MID 50S. -GIH
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
AS OF 305 AM FRIDAY...
SUNDAY THROUGH TUESDAY: HIGH PRESSURE WILL MOVE FROM THE MID-
ATLANTIC STATES TO OFF OF THE CAROLINA COAST ON SUNDAY AND STAY
THERE THROUGH THE EARLY PART OF THE WORK WEEK. THIS WILL PUT CENTRAL
NC IN THE SOUTHWESTERLY RETURN FLOW AND HELP TEMPERATURES RISE INTO
THE MID TO EVEN UPPER 80S BY THE TIME TUESDAY AFTERNOON COMES
AROUND. PRIOR TO THAT...TEMPS ON SUNDAY WILL TOP OUT IN THE MID TO
UPPER 70S BEFORE RISING INTO THE LOW 80S ON MONDAY. LOWS DURING THIS
TIME IN THE MID 50S TO LOWER 60S.
WEDNESDAY THROUGH FRIDAY: A LOW PRESSURE SYSTEM SITUATED OVER THE
CENTRAL U.S. WILL MOVE TOWARDS THE GREAT LAKES ON WEDNESDAY AS A
BACKDOOR COLD FRONT EXTENDING NEARLY DUE EAST FROM THE CENTER OF THE
LOW IS EXPECTED TO MOVE THROUGH THE MID-ATLANTIC STATES AND APPROACH
THE NORTHERN PARTS OF THE FORECAST AREA. THEREFORE THERE WILL BE A
SLIGHT CHANCE OF SHOWERS ESPECIALLY ACROSS THE NORTH ON WEDNESDAY
BUT CONFIDENCE IS STILL LOW ON HOW FAR SOUTH THE FRONT WILL
PROGRESS. WHILE SOME CAPE IS AVAILABLE WEDNESDAY AFTERNOON...THE
SHEAR IS MEAGER UNTIL LATE AFTERNOON WHEN IT PICKS UP ACROSS THE NW
PIEDMONT. THEREFORE A THUNDERSTORM IS POSSIBLE BUT THE MODE OF
PRECIPITATION...IF WE GET ANY...SHOULD BE JUST SHOWERS FOR MUCH OF
THE DAY. THE GFS IS PREDICTING THE COLD FRONT TO MOVE ALL THE WAY
THROUGH NC BECAUSE OF A DEVELOPING MESO-HIGH NORTH OF THE AREA BUT
THIS FEATURE IS LESS PRONOUNCED IN MOST OTHER MODELS. THE ECMWF
FOLLOWS MORE IN LINE WITH WPC THINKING WITH THE COLD FRONT ONLY
REACHING THE NORTHERN PARTS OF THE STATE. MOST MODEL BLENDS ALSO
KEEP US LARGELY IN THE WARM SECTOR ON WEDNESDAY AS WELL. THEREFORE
TRENDING WARMER WITH TEMPERATURES WEDNESDAY AFTERNOON WITH HIGHS AT
LEAST IN THE LOW TO MID 80S WITH SOME UPPER 80S POSSIBLE IN THE
SOUTHWEST. LOWS IN THE UPPER 50S TO LOW 60S WEDNESDAY NIGHT INTO
THURSDAY MORNING.
A SECOND COLD FRONT WILL APPROACH THE AREA AS THE LOW PRESSURE
SYSTEM MOVES NORTHEAST WEDNESDAY NIGHT AND INTO THURSDAY MORNING.
THE COLD FRONT SHOULD MOVE THROUGH THE AREA THROUGHOUT THE DAY ON
THURSDAY BRINGING A CHANCE OF SHOWERS AND A SLIGHT CHANCE OF
THUNDERSTORMS. SHOWERS COULD EXTEND INTO FRIDAY DEPENDING ON THE
POSITION OF THE COLD FRONT AND HOW WELL IT HOLDS TOGETHER BUT
CONFIDENCE IN THE FORECAST THIS FAR OUT IS LOW AT THIS TIME. WILL
CARRY LOW SLIGHT CHANCE POPS IN THE FORECAST FOR NOW. DESPITE THE
SURFACE FRONT TRYING TO MOVE THROUGH THE AREA...THERE WILL NOT BE
MUCH CHANGE IN AIRMASS ON FRIDAY THEREFORE TEMPS ARE EXPECTED TO BE
HIGHER THAN AVERAGE WITH HIGHS IN THE LOW TO MID 80S THURSDAY
AND FRIDAY AND LOWS IN THE UPPER 50S TO MID 60S.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 835 PM FRIDAY...
AREAS OF LIGHT TO BRIEFLY MODERATE RAIN WILL EXIT THE COASTAL PLAIN
COUNTIES PRIOR TO DAYBREAK AS A SFC COLD FRONT CROSSES CENTRAL NC.
IN THE WAKE OF THE RAIN...CEILINGS AND VISIBILITIES WILL LOWER INTO
THE IFR/LIFR CATEGORY. THE VERY POOR AVIATION CONDITIONS EXPECTED
PRIMARILY BETWEEN 09Z-13Z/ AFTER 13Z...CEILINGS AND VISIBILITIES
WILL QUICKLY IMPROVE...LEADING TO VFR CONDITIONS AREAWIDE BY 15Z.
A STEADY NLY WIND AROUND 10KTS WILL DEVELOP AROUND 14Z AND PERSIST
WELL INTO THE AFTERNOON.
WITH HEATING...EXPECT A BROKEN STRATOCU DECK TO FORM WITH CEILINGS
4000-6000FT ANTICIPATED. A FEW SHOWERS MAY ALSO DEVELOP...MAINLY
BETWEEN 19Z SATURDAY-01Z SUNDAY... AND PRIMARILY TO THE NORTH OF
KRDU AND KRWI. THESE SHOWERS WILL BE ALONG/AHEAD OF A SECONDARY
FRONT THAT WILL CROSS OUR REGION EARLY THIS EVENING.
HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT...LEADING TO A PERIOD
OF VFR CONDITIONS WHICH SHOULD LAST UNTIL TUESDAY. AN APPROACHING
FRONT WILL BRING THE NEXT CHANCE FOR SUB VFR CONDITIONS TO CENTRAL
NC TUESDAY NIGHT INTO WEDNESDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...22
SHORT TERM...HARTFIELD
LONG TERM...ELLIS/DND
AVIATION...WSS
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
102 AM EDT SAT APR 23 2016
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE AREA LATE TONIGHT. AN UPPER
LEVEL DISTURBANCE WILL MOVE ACROSS THE AREA EARLY ON SATURDAY.
HIGH PRESSURE WILL BUILD ACROSS THE AREA DURING THE
WEEKEND...MOVING OFFSHORE EARLY NEXT WEEK. WARM TEMPERATURES AND
DRY WEATHER ARE EXPECTED THROUGH MIDWEEK...WITH SCATTERED
THUNDERSTORMS POSSIBLE WITH INCREASING HEAT AND HUMIDITY TOWARDS
THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1 AM SATURDAY...BULK OF CONVECTION HAS NOW MOVED NE OF THE
FORECAST AREA...WITH PENDER COUNTY NOW SEEING MOST OF WHAT IS
LEFT. FORECAST IN GOOD SHAPE...NO CHANGES ANTICIPATED WITH THE
LATEST UPDATE. PREVIOUS DISCUSSION FOLLOWS:
THINGS HAVE UNFOLDED PRETTY MUCH AS EXPECTED OVER THE PAST
SEVERAL HOURS..AND THAT`S QUITE UNUSUAL WHERE CONVECTION IS
INVOLVED! SURFACE-BASED INSTABILITY IS NOW LIMITED TO A NARROW
STRIP ALONG THE IMMEDIATE COAST WHERE TEMPERATURES ARE STILL NEAR
70 DEGREES. INLAND CONVECTION HAS LARGELY DECAYED INTO STRATIFORM
RAIN WHICH EXTENDS AS FAR BACK AS DARLINGTON AND MARLBORO COUNTIES
IN SOUTH CAROLINA.
OVER THE PAST FEW HOURS RAINFALL HAS BEEN QUITE SUBSTANTIAL ACROSS
PORTIONS OF THE SC PEE DEE REGION. THE HIGHEST TOTALS ON OUR
MESONET INCLUDE 2.35 INCHES IN NICHOLS (MARION COUNTY), 1.75
INCHES IN KINGSTREE (WILLIAMSBURG COUNTY), AND 1.73 INCHES IN
GREEN SEA (HORRY COUNTY). RADAR ESTIMATES RANGE AS HIGH AS 3.4
INCHES JUST SOUTH OF FLORENCE AND WEST OF MARION. RAINFALL TOTALS FROM
THIS POINT FORWARD SHOULD BE HIGHEST ACROSS THE CAPE FEAR REGION
OF SE NORTH CAROLINA WITH UP TO AN INCH POSSIBLE WHERE TRAINING IS
OCCURRING FROM LAKE WACCAMAW NORTHEASTWARD TO NEAR WALLACE.
LATEST HRRR AND HRRRX RAINFALL PROJECTIONS LOOK VERY REASONABLE.
DISCUSSION FROM 700 PM FOLLOWS...
STRONG THUNDERSTORM ACTIVITY ACROSS THE SOUTH CAROLINA PEE DEE
REGION HAS YET TO BECOME SEVERE. WE RECEIVED A COUPLE OF REPORTS
OF SMALL HAIL (0.5 TO 0.75 INCH DIAMETER) EARLIER FROM THE
FLORENCE VICINITY. BASED ON TEMPERATURES ALOFT WE`RE LOOKING FOR
50 DBZ ECHOES AT OR ABOVE 26000 FEET TO INDICATE A SEVERE HAIL
RISK TODAY. SO FAR REFLECTIVITY CORES ALOFT HAVE REMAINED BELOW
THIS LEVEL. SURFACE- BASED CAPE IS STILL NEAR 1000 J/KG IN THE
WARM AIR (TEMPS > 70) OUT AHEAD OF THE STORMS.
EVOLUTION OF THE CONVECTION OVER THE NEXT FEW HOURS WILL PROBABLY
FOCUS LESS ON SURFACE-BASED INSTABILITY AND MORE ON ELEVATED
INSTABILITY COUPLED WITH SYNOPTICALLY-DRIVEN LOW LEVEL CONVERGENCE
ACROSS THE INTERIOR COASTAL PLAIN. VIRTUALLY ALL MODELS SHOW THE
WEAK AREA OF LOW PRESSURE SOUTH OF ORANGEBURG SC WILL MOVE SLOWLY
NORTH-NORTHEASTWARD. CONVERGING WINDS INTO THIS FEATURE SHOULD
HELP MAINTAIN SHOWERS AND THUNDERSTORMS LARGELY WHERE THE ACTIVITY
CURRENTLY IS OVER THE NEXT SEVERAL HOURS. OUR FOCUS MAY SHIFT
AWAY FROM A HAIL RISK TO A FLOODING RISK WITH TIME.
AS THE WEAK LOW FINALLY MAKES IT UP INTO SE NORTH CAROLINA BY
MIDNIGHT THE BETTER LOW LEVEL CONVERGENCE SHOULD HELP SUPPORT
SHOWERS AND STORMS DOWN AT THE COAST. FORECAST POPS RANGE FROM 100
PERCENT ALONG THE INTERSTATE 95 CORRIDOR TO 60-90 PERCENT ON THE
COAST...INCREASING FROM SOUTH TO NORTH.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY NIGHT/...
AS OF 220 PM FRIDAY...A ROBUST MID-LEVEL SHORTWAVE TROUGH WILL
MOVE ACROSS THE FORECAST AREA DURING SAT. SHOWERS MAY BE LURKING
NEAR THE COAST AND OFFSHORE AT FIRST LIGHT SAT. THEN AS THIS
FEATURE APPROACHES...SOME COOLING ALOFT COUPLED WITH HEATING AT
THE SURFACE WILL STEEPEN LAPSE RATES. THIS SHOULD ALLOW ISOLATED
TO SCATTERED SHOWERS TO DEVELOP. THE BEST LIFT/COLD POOL
ASSOCIATED WITH THIS DISTURBANCE WILL TRACK N OF THE AREA...WITH
OUR FORECAST AREA ON THE SOUTHERN PERIPHERY. THUS...WILL PORTRAY
HIGHEST POPS NE HALF OF THE FORECAST AREA.
THE SHOWERS SHOULD DISSIPATE WITH THE LOSS OF HEATING WHICH WILL BE
COINCIDENT WITH THE TROUGH MOVING OFFSHORE. WE ARE NOT LOOKING FOR
SIGNIFICANT RAINFALL ON SAT...JUST HIT OR MISS SHOWERS WHICH WILL
TEND TO BE FAST PACED AND THUS BRIEF.
DRY WEATHER THROUGHOUT SAT NIGHT THROUGH SUN NIGHT AS HIGH PRESSURE
BUILDS SOUTHWARD ACROSS THE AREA. TEMPS WILL BE JUST ABOUT NORMAL
FOR LATE APRIL.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 220 PM FRIDAY...THE WEEK WILL BEGIN WITH HIGH PRESSURE
SURFACE-ALOFT PUSHING OFF THE EAST COAST. RETURN FLOW AROUND THE
SURFACE HIGH WILL SET UP LATE MONDAY AND PERSIST THROUGH
WEDNESDAY. 12Z GFS IS INDICATING A WEAK SURFACE FRONT MAY SLIP
SOUTH AND BRIEFLY INTO THE SOUTHERN CWA ON WEDNESDAY BEFORE
QUICKLY LIFTING BACK TO THE NORTH. WILL TWEAK THE FORECAST TOWARDS
THIS SOLUTION BY INDICATING A BRIEF SHIFT TO NORTHEAST WINDS
ACROSS THE NORTHWEST HALF OF THE CWA ON WEDNESDAY. A SMALL CHANCE
OF SHOWERS WILL BE ASSOCIATED WITH THIS BOUNDARY. BETTER CHANCES
FOR CONVECTION ARE EXPECTED ON THURSDAY AND FRIDAY...ALONG WITH A
CHANCE OF THUNDER...AS SURFACE-BASED INSTABILITY INCREASES WITH
SURGING TEMPS/DEWPOINTS. MODELS CONTINUE TO INDICATE A COLD
FRONTAL PASSAGE FRIDAY NIGHT.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 06Z...SHOWERS AND ISOLATED THUNDERSTORMS AHEAD OF A WEAK
COLD FRONT HAVE MOVE MOSTLY NE OF THE TERMINALS EARLY THIS MORNING
LEAVING ISOLATED LIGHT SHOWERS IN ITS WAKE. SHOWERS CHANCES WILL
COME TO AN END EARLY THIS MORNING AS THE FRONT SLOWLY MOVES
EAST...PUSHING OFF THE COAST BEFORE DAYBREAK. WINDS WILL BECOME
W-NW BEHIND THE FRONT... BUT A LACK OF COLD ADVECTION OR A TIGHT
GRADIENT WILL KEEP WINDS LIGHT. LOW LEVEL MOISTURE WILL MANIFEST
AS LOW STRATUS ALONG THE COAST WHERE BOUNDARY LAYER WINDS ARE
SLIGHTLY HIGHER...AND FOG AT INLAND TERMINALS WHERE BOUNDARY LAYER
MIXING WILL BE LESS. THERE WILL BE A PERIOD OF TIME EARLY THIS
MORNING WHERE CEILINGS AND/OR VISIBILITIES WILL DROP INTO THE IFR
CATEGORY...POSSIBLY LIFR AT KFLO/KLBT IF SKIES CLEAR ENOUGH. CIGS
SHOULD INCREASE TO MVFR THEN VFR BY MID-MORNING. WINDS WILL BE
W-NW BECOMING N LATER IN THE AFTERNOON. SOME ISOLATED SHOWERS
POSSIBLE NEAR KILM/KCRE...DISSIPATING BY EVENING.
EXTENDED OUTLOOK...VFR
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1 AM SATURDAY...NO CHANGES ARE NEEDED TO THE FORECAST THIS
EVENING. PREVIOUS DISCUSSION FROM 700 PM FOLLOWS:
HIGH PRESSURE OUT NEAR BERMUDA IS DRAGGING AIR FROM THE NORTHERN
CARIBBEAN AND BAHAMAS UP THE COAST AND ACROSS THE CAROLINAS. A
COLD FRONT JUST WEST OF THE APPALACHIANS IS MOVING EASTWARD AND
SHOULD REACH THE COASTAL WATERS AROUND SUNRISE SATURDAY MORNING.
SOUTH WINDS SHOULD AVERAGE 15 KT ACROSS THE SC WATERS AND 15-20 KT
ACROSS THE NC WATERS TONIGHT... DIMINISHING BY ABOUT 5 KNOTS AFTER
3-4 AM AS A WAVE OF LOW PRESSURE ALONG THE FRONT IN SOUTH CAROLINA
MOVES NORTH OF THE AREA. SHOWERS AND THUNDERSTORMS INLAND SHOULD
REACH THE COASTAL WATERS BY LATE THIS EVENING AND THERE MAY BE
GOOD COVERAGE OF RAIN ACROSS THE WATERS AFTER
MIDNIGHT...ESPECIALLY NORTH OF CAPE FEAR.
SEAS ARE CURRENTLY 3-4 FEET AT THE CAPE FEAR NEARSHORE BUOYS AND 5
FEET OUT AT THE FRYING PAN SHOALS BUOY. LOOK FOR THESE WAVE
HEIGHTS TO BUILD BY ABOUT A FOOT OVER THE NEXT SEVERAL HOURS.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 220 PM FRIDAY...A COLD FRONT MAY LINGER NEAR THE OFFSHORE
WATERS...WAITING ON A POTENT SHORTWAVE TROUGH BEFORE PUSHING
FURTHER OFFSHORE DURING SAT. W WINDS TO START THE DAY SAT ARE
EXPECTED TO VEER TO NW....BEFORE SHIFTING TO THE N AND NE AND
INCREASING TO NEAR 20 KT SAT NIGHT. A SMALL CRAFT SHOULD EXERCISE
CAUTION HEADLINE MAY BE REQUIRED SAT NIGHT INTO EARLY SUN MORNING.
AS HIGH PRESSURE TO THE N GROWS CLOSER...WIND SPEEDS WILL DECREASE
TO 10 TO 15 KT DURING SUN AND TO 10 KT OR LESS SUN NIGHT. THE WIND
DIRECTION WILL VEER FROM NE SUN TO E SUN NIGHT.
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 220 PM FRIDAY...SURFACE HIGH PRESSURE WILL SHIFT OFF THE
COAST EARLY MONDAY AND WILL BE THE MAIN INFLUENCE ON THE MARINE
FORECAST THROUGH WEDNESDAY. WINDS ARE EXPECTED TO BE LIGHT WITH
SOME VARIABILITY EARLY MONDAY UNTIL THE CENTER OF THE HIGH MOVES
AWAY FROM THE COAST. THIS WILL ALLOW SOUTHWEST WINDS TO DEVELOP
OVER THE WATERS...WHICH WILL INCREASE TO A 10-15 KNOT RANGE TUE-
WED. A WEAK COLD FRONT IS EXPECTED TO APPROACH FROM THE NORTH ON
WEDNESDAY AND WILL RESULT IN WINDS BACKING TO THE EAST AND PERHAPS
NORTHEAST BRIEFLY..GENERALLY NORTH OF CAPE FEAR.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...CRM
NEAR TERM...REK/TRA
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...REK/MRR
MARINE...REK/TRA/JDW
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
532 AM EDT SAT APR 23 2016
.SYNOPSIS...
A COLD FRONT WILL CONTINUE TO PUSH THROUGH THE REGION EARLY THIS
MORNING...EXITING SOUTHEAST PA BY DAWN. HIGH PRESSURE WILL BUILD
INTO THE REGION THIS WEEKEND. ANOTHER COLD FRONT IS LIKELY TO PUSH
ACROSS THE AREA TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MAIN FEATURE IN WATER VAPOR IMAGERY THIS MORNING IS UPPER LOW
TRACKING ACROSS WEST VIRGINIA. UPPER LVL DIFFLUENCE IN ADVANCE OF
THIS FEATURE IS SUPPORTING LINGERING SHOWERS ACROSS SOUTHERN PA AS
OF 09Z. AS UPPER LOW TRACKS EAST...EXPECT THE SHOWERS TO PUSH SE
OF THE REGION LATER THIS MORNING. LATEST HRRR AND NCAR ENSEMBLE
SUGGEST THE SHOWERS COULD LAST UNTIL ARND 14Z OVER LANCASTER CO.
IR IMAGERY AT 09Z SHOWS AN EXTENSIVE STRATUS SHIELD EXTENDING ALL
THE WAY BACK TO LKS ERIE AND ONTARIO. HOWEVER...MDL SOUNDINGS
CONTINUE TO INDICATE CLEARING SKIES BY MIDDAY...DUE TO DEEPENING
BLYR AND MIXING OF MUCH DRIER AIR ALOFT. SUPERBLEND TEMPS LOOKING
FAIRLY SEASONABLE THIS AFTN...RANGING FROM THE U50S OVR THE N
MTNS...TO THE M-U60S SE COUNTIES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
HIGH PRESSURE WILL BECOME CENTERED OVER THE REGION LATE TONIGHT
WITH CLEAR SKIES...LOW PWATS AND NEARLY CALM AIR. INCLUDED PATCHY
FROST ACROSS THE MTNS NEAR THE I-80 CORRIDOR AND WIDESPREAD SUB-
FREEZING TEMPS ACROSS THE NRN MTNS. HOWEVER...THIS AREA OF THE
STATE IS STILL OUTSIDE OF THE BEGINNING OF THE GROWING SEASON. A
LOW PROB FOR A FROST ADVISORY IS IN THE EAST/WEST SLIVER OF
COUNTIES JUST ALONG AND JUST SOUTH OF I-80 WHERE THE OFFICIAL
START TO THE GROWING SEASON WAS THURSDAY/APRIL 21ST.
AFTER THE CHILLY START...ABUNDANT SUNSHINE SHOULD PUSH TEMPS WELL
INTO THE 60S BY SUNDAY AFTN. HIGH PRES DIRECTLY OVERHEAD SHOULD
ENSURE VERY LGT WINDS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
A SURGE OF WARMER AIR SHOULD WORK INTO PA MONDAY...AS HIGH DRIFTS
OFF THE COAST AND WARM FRONT LIFTS NORTHWARD THRU THE E GRT LKS.
MSUNNY SKIES AND MDL 8H TEMPS NR 12C SHOULD SUPPORT MAX TEMPS
FROM THE M70S N MTNS...TO THE L80S IN THE SOUTHERN VALLEYS.
ALL MED RANGE GUIDANCE INDICATES A WEAKENING SHORTWAVE TRACKING
THRU THE E GRK LKS WILL PUSH A COLD FRONT AND ASSOC BAND OF
SHOWERS SOUTHWARD ACROSS PA BY TUESDAY. SOME MDL DISAGREEMENT WITH
REGARDS TIMING OF FROPA...WITH SLOWER ECENS/SREF/CANADIAN
SOLUTIONS CURRENTLY FAVORED OVR THE FASTER GEFS. THIS SLOWER
SOLUTION RESULTS IN A GOOD CHC OF SHOWERS LASTING THRU TUESDAY...RATHER
THAN JUST MON NIGHT. CURRENT MDL-BLENDED QPF INDICATES THIS WILL
BE A RELATIVELY LIGHT RAINFALL FOR MOST OF THE AREA WITH AMTS
GENERALLY LESS THAN A HALF INCH.
LATEST ECENS AND NAEFS POINT TOWARD A DRY/SEASONABLE WEDNESDAY...AS
SFC RIDGE BUILDS ACROSS PA. NEXT CHC OF SHOWERY WX ARRIVES
THURSDAY WHEN ECENS/NAEFS BOTH TRACK A SFC LOW JUST SOUTH OF THE
STATE. FAIR WX LIKELY TO RETURN BY FRIDAY...AS LOW DEPARTS THE NE
COAST AND DRIER NW FLOW FOLLOWS ACROSS PA.
&&
.AVIATION /09Z SATURDAY THROUGH WEDNESDAY/...
SHOWERS WILL CONTINUE TO IMPACT PORTIONS OF SOUTHERN PA THROUGH
DAWN IN VICINITY OF SLOW MOVING COLD FRONT.
TO THE NORTH OF THE FRONT...EXTENSIVE STRATUS SHIELD NOTED ACROSS
NORTHERN PA INTO UPSTATE NY...AND CIGS OVER NORTHERN AND WESTERN
SECTIONS OF CWA WILL GRADUALLY FALL TO MVFR AND IFR AS NORTHERLY
FLOW BEGINS TO INCREASE. GENERALLY VFR OVER THE SE...THOUGH A
BRIEF PERIOD OF MVFR POSS AROUND DAWN.
RESTRICTIONS WILL BE IN PLACE OVER NW HALF TO START THE DAY
SAT AS UPPER TROUGH AXIS PASSES THROUGH...BUT CONDITIONS WILL
IMPROVE TO VFR LATE MORNING AS HIGH PRESSURE BUILDS IN FROM THE
NW. A NORTH WIND WILL PICK UP WITH SFC SPEEDS OF 10-20
MPH...BEFORE TAPERING OFF SAT EVE.
OUTLOOK...
SAT...AM LOW CIGS W MTNS.
SUN...NO SIG WX EXPECTED.
MON-TUE...PM SHRA DEVELOPING MONDAY AND CONTINUING INTO TUESDAY.
REDUCTIONS POSSIBLE...MAINLY NW PA.
WED...NO SIG WX EXPECTED.
&&
.FIRE WEATHER...
WINDS WILL BECOME A BIT GUSTY THIS AFTN WITH RELATIVE HUMIDITY
FALLING TO NEAR 30 PERCENT BY LATE AFTN. LATEST BUFKIT SOUNDINGS
SUPPORT GUSTS BTWN 15-20KTS LATER TODAY ACROSS EASTERN PA...WITH
CONDS CLOSE TO RED FLAG CRITERIA POSSIBLE FOR A COUPLE OF HOURS
DURING LATE AFTN OR EARLY EVENING. GIVEN THE MARGINAL CONDS AND
THE LGT RAIN THAT FELL OVERNIGHT...HAVE OPTED NOT TO ISSUE EITHER
A FIRE WX WATCH OR RED FLAG WARNING. DAY SHIFT WILL LIKELY NEED TO
CONTACT PA FORESTRY FOR LATEST ASSESSMENT OF FUEL MOISTURE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD
AVIATION...RXR
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
305 AM EDT SAT APR 23 2016
.SYNOPSIS...
A COLD FRONT WILL CONTINUE TO PUSH THROUGH THE REGION EARLY THIS
MORNING...EXITING SOUTHEAST PA BY DAWN. HIGH PRESSURE WILL BUILD
INTO THE REGION THIS WEEKEND. ANOTHER COLD FRONT IS LIKELY TO PUSH
ACROSS THE AREA MONDAY NIGHT INTO TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
SHOWERS STILL FALLING ACROSS SOUTHERN PA AT 06Z IN VICINITY OF
SLOW MOVING COLD FRONT. BASED ON LATEST HRRR AND RADAR
TRENDS...WILL MAINTAIN LIKELY POPS ACROSS THE SOUTHERN COUNTIES
THRU DAWN.
TO THE NORTH OF THE FRONT...EXTENSIVE STRATUS SHIELD NOTED ACROSS
NORTHERN PA INTO UPSTATE NY...SO EXPECT GENERALLY OVERCAST SKIES
THRU DAWN. BLEND OF LATEST LAMP/SUPERBLEND GUIDANCE INDICATE LOW
TEMPS SHOULD RANGE FROM THE L40S ACROSS THE NW MTNS...TO THE M50S
ACROSS THE SE COUNTIES.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SUNDAY/...
CAN/T RULE OUT A FEW LINGERING SHOWERS LASTING THRU LATE SAT AM
ACROSS THE LOWER SUSQ VALLEY. THE MAIN FCST PROBLEM FOR LATER
SATURDAY MORNING WILL SURROUND THE EXTENT OF LOW CLOUDS...AND
TIMING OF THEIR DISSIPATION.
THE ARRIVAL OF HIGH PRESSURE AND DRIER NNW FLOW SHOULD BRING
MSUNNY SKIES TO THE ENTIRE AREA BY SAT AFTN. SUPERBLEND TEMPS
LOOKING SEASONABLE SAT...FROM THE U50S NW MTNS TO M-U60S SE
COUNTIES.
THE WIND WILL AVERAGE 10-15 KTS WITH SOME GUSTS IN THE UPPER TEENS
LIKELY CENTRAL AND WESTERN PENN. SUSTAINED AND PEAK GUSTS
NORTHERLY WIND GUSTS COULD BE 5-8 KTS HIGHER ACROSS THE EAST
WHERE LLVL P-GRADIENT IS THE TIGHTEST AHEAD OF HIGH PRESSURE OVER
THE GLAKES REGION. LATER SHIFTS MAY HAVE TO CONSIDER/COLLABORATE
WITH SURROUNDING WFOS A FIRE WEATHER WATCH OR RED FLAG WARNING FOR
SATURDAY SHOULD RAINFALL AMOUNTS BE LESS THAN CURRENTLY FCST.
HIGH PRESSURE WILL BECOME CENTERED OVER THE REGION SATURDAY NIGHT
WITH CLEAR SKIES...LOW PWATS AND NEARLY CALM AIR. INCLUDED PATCHY
FROST ACROSS THE MTNS NEAR THE I-80 CORRIDOR AND LARGER AREAS OF
FROST ACROSS THE NRN MTNS. HOWEVER...THIS AREA OF THE STATE IS
STILL OUTSIDE OF THE BEGINNING OF THE GROWING SEASON. A LOW PROB
FOR A FROST ADVISORY IS IN THE EAST/WEST SLIVER OF COUNTIES JUST
ALONG AND JUST SOUTH OF I-80 WHERE THE OFFICIAL START TO THE
GROWING SEASON WAS THURSDAY/APRIL 21ST.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
GUIDANCE HAS BEEN CONSISTENT IN SHOWING THE BROAD
TROUGH/RIDGE/TROUGH CONFIGURATION EXTENDING FROM THE GREAT BASIN
TO THE PLAINS INTO THE MID ATLANTIC REGION AT THE START OF THE
LONG TERM PERIOD TRANSITIONING TOWARD A MEAN WESTERN
TROUGH/BUILDING RIDGE IN THE EAST THRU NEXT WEEK. UNCERTAINTY HAS
ALSO DECREASED OVER THE POSITION OF AN EAST/WEST SFC FRONTAL
BOUNDARY AND LOW LEVEL BAROCLINIC ZONE WITH COLDER TEMPERATURES
STAYING WELL TO THE NORTH OF PA ALONG THE NRN TIER STATES/CANADIAN
BORDER.
THE WEEKEND AS A WHOLE LOOKS FAIR AND DRY WITH A RISK OF
FROST/FREEZE CONDITIONS SATURDAY NIGHT INTO SUNDAY MORNING. WAVES
OF LOW PRESSURE MOVG EWD ALONG WAVY SFC FRONTAL BOUNDARY PRESSING
SWD FROM THE LOWER LAKES/UPSTATE NY SHOULD BRING PERIODS OF RAIN
EARLY NEXT WEEK BUT CONFIDENCE IN EXACT TIMING OF GREATEST PCPN
RISK IS STILL BELOW AVERAGE AND COULD EASILY SHIFT +/- 12 HOURS.
MODEL CONSENSUS FAVORS A DRY PERIOD ON WEDNESDAY BEFORE RAIN PROBS
TREND HIGHER FROM WEST TO EAST INTO THE SECOND HALF OF NEXT WEEK.
ASIDE FROM A CHILLY SUNDAY MORNING...THE GLOBAL ENSEMBLE MEANS
ALONG WITH NATIONAL/REGIONAL BLENDS ALL SUPPORT ABOVE NORMAL TEMPS
THROUGH THE MEDIUM RANGE PERIOD.
&&
.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
SHOWERS WILL CONTINUE TO IMPACT PORTIONS OF SOUTHERN PA THROUGH
DAWN IN VICINITY OF SLOW MOVING COLD FRONT.
TO THE NORTH OF THE FRONT...EXTENSIVE STRATUS SHIELD NOTED ACROSS
NORTHERN PA INTO UPSTATE NY...AND CIGS OVER NORTHERN AND WESTERN
SECTIONS OF CWA WILL GRADUALLY FALL TO MVFR AND IFR AS NORTHERLY
FLOW BEGINS TO INCREASE. GENERALLY VFR OVER THE SE...THOUGH A
BRIEF PERIOD OF MVFR POSS AROUND DAWN.
RESTRICTIONS WILL BE IN PLACE OVER NW HALF TO START THE DAY
SAT AS UPPER TROUGH AXIS PASSES THROUGH...BUT CONDITIONS WILL
IMPROVE TO VFR LATE MORNING AS HIGH PRESSURE BUILDS IN FROM THE
NW. A NORTH WIND WILL PICK UP WITH SFC SPEEDS OF 10-20
MPH...BEFORE TAPERING OFF SAT EVE.
OUTLOOK...
SAT...AM LOW CIGS W MTNS.
SUN...NO SIG WX EXPECTED.
MON-TUE...PM SHRA DEVELOPING MONDAY AND CONTINUING INTO TUESDAY.
REDUCTIONS POSSIBLE...MAINLY NW PA.
WED...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD/LAMBERT
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD/LAMBERT
LONG TERM...FITZGERALD/GARTNER
AVIATION...RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
210 AM EDT SAT APR 23 2016
.SYNOPSIS...
A COLD FRONT WILL CONTINUE TO PUSH THROUGH THE REGION EARLY THIS
MORNING...EXITING SOUTHEAST PA BY DAWN. HIGH PRESSURE WILL BUILD
INTO THE REGION THIS WEEKEND. ANOTHER COLD FRONT IS LIKELY TO PUSH
ACROSS THE AREA MONDAY NIGHT INTO TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
SHOWERS STILL FALLING ACROSS SOUTHERN PA AT 06Z IN VICINITY OF
SLOW MOVING COLD FRONT. BASED ON LATEST HRRR AND RADAR
TRENDS...WILL MAINTAIN LIKELY POPS ACROSS THE SOUTHERN COUNTIES
THRU DAWN.
TO THE NORTH OF THE FRONT...EXTENSIVE STRATUS SHIELD NOTED ACROSS
NORTHERN PA INTO UPSTATE NY...SO EXPECT GENERALLY OVERCAST SKIES
THRU DAWN. BLEND OF LATEST LAMP/SUPERBLEND GUIDANCE INDICATE LOW
TEMPS SHOULD RANGE FROM THE L40S ACROSS THE NW MTNS...TO THE M50S
ACROSS THE SE COUNTIES.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SUNDAY/...
CAN/T RULE OUT A FEW LINGERING SHOWERS LASTING THRU LATE SAT AM
ACROSS THE LOWER SUSQ VALLEY. THE MAIN FCST PROBLEM FOR LATER
SATURDAY MORNING WILL SURROUND THE EXTENT OF LOW CLOUDS...AND
TIMING OF THEIR DISSIPATION.
THE ARRIVAL OF HIGH PRESSURE AND DRIER NNW FLOW SHOULD BRING
MSUNNY SKIES TO THE ENTIRE AREA BY SAT AFTN. SUPERBLEND TEMPS
LOOKING SEASONABLE SAT...FROM THE U50S NW MTNS TO M-U60S SE
COUNTIES.
THE WIND WILL AVERAGE 10-15 KTS WITH SOME GUSTS IN THE UPPER TEENS
LIKELY CENTRAL AND WESTERN PENN. SUSTAINED AND PEAK GUSTS
NORTHERLY WIND GUSTS COULD BE 5-8 KTS HIGHER ACROSS THE EAST
WHERE LLVL P-GRADIENT IS THE TIGHTEST AHEAD OF HIGH PRESSURE OVER
THE GLAKES REGION. LATER SHIFTS MAY HAVE TO CONSIDER/COLLABORATE
WITH SURROUNDING WFOS A FIRE WEATHER WATCH OR RED FLAG WARNING FOR
SATURDAY SHOULD RAINFALL AMOUNTS BE LESS THAN CURRENTLY FCST.
HIGH PRESSURE WILL BECOME CENTERED OVER THE REGION SATURDAY NIGHT
WITH CLEAR SKIES...LOW PWATS AND NEARLY CALM AIR. INCLUDED PATCHY
FROST ACROSS THE MTNS NEAR THE I-80 CORRIDOR AND LARGER AREAS OF
FROST ACROSS THE NRN MTNS. HOWEVER...THIS AREA OF THE STATE IS
STILL OUTSIDE OF THE BEGINNING OF THE GROWING SEASON. A LOW PROB
FOR A FROST ADVISORY IS IN THE EAST/WEST SLIVER OF COUNTIES JUST
ALONG AND JUST SOUTH OF I-80 WHERE THE OFFICIAL START TO THE
GROWING SEASON WAS THURSDAY/APRIL 21ST.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
GUIDANCE HAS BEEN CONSISTENT IN SHOWING THE BROAD
TROUGH/RIDGE/TROUGH CONFIGURATION EXTENDING FROM THE GREAT BASIN
TO THE PLAINS INTO THE MID ATLANTIC REGION AT THE START OF THE
LONG TERM PERIOD TRANSITIONING TOWARD A MEAN WESTERN
TROUGH/BUILDING RIDGE IN THE EAST THRU NEXT WEEK. UNCERTAINTY HAS
ALSO DECREASED OVER THE POSITION OF AN EAST/WEST SFC FRONTAL
BOUNDARY AND LOW LEVEL BAROCLINIC ZONE WITH COLDER TEMPERATURES
STAYING WELL TO THE NORTH OF PA ALONG THE NRN TIER STATES/CANADIAN
BORDER.
THE WEEKEND AS A WHOLE LOOKS FAIR AND DRY WITH A RISK OF
FROST/FREEZE CONDITIONS SATURDAY NIGHT INTO SUNDAY MORNING. WAVES
OF LOW PRESSURE MOVG EWD ALONG WAVY SFC FRONTAL BOUNDARY PRESSING
SWD FROM THE LOWER LAKES/UPSTATE NY SHOULD BRING PERIODS OF RAIN
EARLY NEXT WEEK BUT CONFIDENCE IN EXACT TIMING OF GREATEST PCPN
RISK IS STILL BELOW AVERAGE AND COULD EASILY SHIFT +/- 12 HOURS.
MODEL CONSENSUS FAVORS A DRY PERIOD ON WEDNESDAY BEFORE RAIN PROBS
TREND HIGHER FROM WEST TO EAST INTO THE SECOND HALF OF NEXT WEEK.
ASIDE FROM A CHILLY SUNDAY MORNING...THE GLOBAL ENSEMBLE MEANS
ALONG WITH NATIONAL/REGIONAL BLENDS ALL SUPPORT ABOVE NORMAL TEMPS
THROUGH THE MEDIUM RANGE PERIOD.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
SHOWERS CONTINUE TO MOVE TO THE EAST. STILL HAVE A SLIGHT CHANCE
FOR THUNDER BUT HAVE LEFT OUT ANY MENTION OF TSTM IN TAFS. THERE
HAS BEEN LIMITED RESTRICTIONS THROUGH THE EVENING. THOUGH IFR IS
POSSIBLE AT AOO THROUGH 06Z...AND AT MDT...JST AND LNS THROUGH 09Z
AS THE SYSTEM PASSES. THE RESTRICTIONS CONTINUE OVER WESTERN AND
CENTRAL MTNS INTO SAT AS UPPER TROUGH PASSES THROUGH. EXPECT
CONDITIONS TO IMPROVE BETWEEN 13Z TO 15Z AS THE WINDS MIX
DOWN...WITH GUSTY WINDS AND VFR CIGS AND VSBYS THROUGH SATURDAY.
STILL A CHANCE FOR LOW BUT VFR CIGS AT JST.
OUTLOOK...
SAT...AM LOW CIGS W MTNS.
SUN...NO SIG WX EXPECTED.
MON-TUE...PM SHRA DEVELOPING MONDAY AND CONTINUING INTO TUESDAY.
REDUCTIONS POSSIBLE...MAINLY NW PA.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD/LAMBERT
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD/LAMBERT
LONG TERM...FITZGERALD/GARTNER
AVIATION...LAMBERT/RXR
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
412 AM MDT SAT APR 23 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 412 AM MDT SAT APR 23 2016
SOUTHWEST WINDS ALOFT WILL BE INCREASING TODAY AHEAD OF AN
APPROACHING UPPER TROUGH THAT IS OVER WESTERN UTAH THIS MORNING.
AS DAYTIME WARMING INCREASES THE DEPTH OF THE BOUNDARY LAYER...THE
WINDS ALOFT ARE EXPECTED TO MIX DOWN TO THE SURFACE...BRINGING
GUSTY WINDS TO THE PLAINS THROUGH THE AFTERNOON. THE LATEST RUNS
OF THE HRRR MODEL HAVE BEEN SHOWING A CONSOLIDATED BAND OF SHOWERS
ASSOCIATED WITH THE TROUGH AXIS MOVING OVER THE MOUNTAINS AFTER
22Z. LIGHTNING HAS BEEN DETECTED THIS MORNING OVER
UTAH...INDICATING THE INSTABILITY OF THE AIRMASS THAT WILL
ACCOMPANY THE UPPER TROUGH AS IT MOVES ACROSS THE STATE. MODEL
SOUNDINGS SHOW THAT FREEZING LEVELS WILL BE AROUND 12000 FEET MSL
AHEAD OF THE TROUGH...SO THE MOUNTAINS WILL SEE A MIX OF RAIN AND
SNOW WITH THE AFTERNOON SHOWERS...WITH THE SNOW LEVELS DROPPING
LATER IN THE EVENING. MODEL SOUNDINGS ALSO SHOW THE AIRMASS WILL
BE QUITE DRY ON THE PLAINS...MAKING IT TOUGH FOR ANY RAIN TO
REACH THE GROUND ON THE PLAINS. HOWEVER...GUSTY WINDS ARE EXPECTED
THROUGH THE LATE AFTERNOON AND EVENING DUE TO DOWNBURSTS FROM
VIRGA SHOWERS AND THE SOUTHWEST FLOW AT MID-LEVELS BEING MIXED
DOWN TO THE SURFACE. AS THE UPPER TROUGH MOVES EASTWARD AND ONTO
THE PLAINS...SHOWER ACTIVITY OVER THE MOUNTAINS AND PLAINS WILL BE
DECREASING BY MIDNIGHT. TEMPERATURES WILL ALSO COOL DOWN LATER
TONIGHT AS THE POST-TROUGH AIRMASS MOVES IN.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 412 AM MDT SAT APR 23 2016
AN UPPER LEVEL STORM SYSTEM WILL BE CENTERED OVER ERN WY EARLY ON
SUN AND THEN WILL MOVE SLOWLY EAST INTO SCNTRL SOUTH DAKOTA AND
NCNTRL NEBRASKA BY EARLY SUN EVENING. COMBINATION OF RATHER STG SFC
GRADIENT AND QG DOWNWARD DESCENT WILL ALLOW FOR STG WINDS IN THE
MORNING ESPECIALLY ACROSS THE NRN FOOTHILLS AND HIGHER MTNS. WOULD
NOT BE SURPRISED TO SEE A SOME SPOTS RECEIVE HIGH WIND CRITERIA
FOR A FEW HOURS. MEANWHILE GUSTY WINDS WILL ALSO OCCUR OVER THE
PLAINS BUT SPEEDS SHOULD STAY BLO HIGH WIND CRITERIA.
AS FAR AS PCPN CROSS-SECTIONS CONTINUE TO SHOW FAVORABLE OROGRAPHICS
AND LINGERING MOISTURE IN THE NRN MTNS MAINLY NR THE WY BORDER WITH
ADVISORY AMOUNTS POSSIBLE IN ZN 31. OTHERWISE MAY SEE A FEW AFTN
SHOWERS ACROSS THE PLAINS NEAR THE WY-NE BORDER. AS FOR HIGHS
READINGS WILL DROP BACK INTO THE 65 TO 70 DEGREE RANGE ACROSS NERN
CO.
BY MON THE FLOW ALOFT WILL BECOME SWLY AS ANOTHER STORM SYSTEM
MOVES INTO THE GREAT BASIN. MEANWHILE SFC LOW PRES WILL INTENSIFY
ALONG THE FOOTHILLS WITH GUSTY SSE WINDS ACROSS THE PLAINS BY
AFTN. AS FOR PCPN POTENTIAL...MOISTURE WILL INCREASE BY AFTN IN
THE MTNS AND COMBINE WITH FAVORABLE LAPSE RATES FOR SOME SCT
SHOWERS AND POSSIBLE A FEW TSTMS. OVER NERN CO IT WILL BE DRY
ALTHOUGH THERE COULD BEA FEW LATE AFTN HIGH BASED STORMS ALONG THE
FRONT RANGE. AS FOR HIGHS READINGS WILL BE IN THE MID 60S TO LOWER
70S ACROSS THE PLAINS.
FOR MON NIGHT THRU TUE ONCE AGAIN ITS NOT CLEAR HOW THE UPPER LEVEL
STORM SYSTEM WILL EVOLVE. IT APPEARS ONCE PIECE OF ENERGY MAY
MOVE NNE INTO THE NRN ROCKIES WHILE SIGNIFICANT ENERGY REFORMS
INTO A CLOSED LOW NEAR THE FOUR CORNERS AREA BY TUE. MEANWHILE
THE MAIN SFC LOW MAY INTENSIFY OVER SERN CO WITH DEEPER LOW LVL
MOISTURE ADVECTING INTO NERN CO NORTH OF A WRM FNT. OVERALL SHOULD
SEE A CHC OF SHOWERS AND TSTMS ESPECIALLY ACROSS THE PLAINS MON
NIGHT. ON TUE BEST CHC OF SHOWERS AND TSTMS WILL BE IN THE AFTN
ACROSS THE AREA. THERE ALSO COULD BE SOME THREAT OF STRONGER
STORMS ACROSS PORTIONS OF THE PLAINS TUE AFTN NEAR THE TRIPLE
POINT AND JUST NORTH OF THE WRM FRONT.
BY TUE NIGHT INTO WED THERE IS SOME POTENTIAL THAT THE UPPER LEVEL
LOW NEAR THE FOUR CORNERS WILL INTENSIFY AND MOVE INTO SERN CO BY
12Z WED AND THEN LIFT NORTHEAST INTO NWRN KANSAS/SWRN NEBRASKA BY
WED AFTN. IF THIS OCCURS THEN THERE COULD BE SOME SIGNIFICANT PCPN
TUE NIGHT INTO WED ACROSS PORTIONS OF NRN CO. BUFFER SOUNDINGS SHOW
TEMPS WILL BE WRM ENOUGH FOR PCPN TO FALL MOSTLY AS RAIN ACROSS THE
PLAINS WITH THE SNOW LEVEL ABOVE 6000 FT.
FOR WED NIGHT INTO THU THE UPPER LEVEL LOW IS FCST TO MOVE ENE OF
THE AREA AS ANOTHER SYSTEM DIVES INTO SRN CALIFORNIA. THUS SHOULD
SEE DRIER CONDITIONS WED NIGHT INTO THU. HOWEVER LINGERING MOISTURE
COMBINED WITH AFTN HEATING MAY LEAD TO A SLIGHT CHC OF SHOWERS AND
TSTMS ACROSS THE HIGHER TERRAIN AND ALONG THE FRONT RANGE.
BY FRI THE ECMWF AND GFS WANT TO EJECT THE LOW FM SRN CALIFORNIA
INTO THE FOUR CORNERS AREA BY FRI AFTN WHILE THE CANADIAN MODEL IS
CONSIDERABLY SLOWER AND FUTHER SW. THIS FAR OUT HARD TO SAY WHAT
WILL HAPPEN WITH THIS NEXT FEATURE. FOR NOW WILL JUST GO WITH CHC
POPS IN THE MTNS WITH A SLIGHT CHC OVER THE PLAINS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 412 AM MDT SAT APR 23 2016
VFR CONDITIONS EXPECTED TO CONTINUE THROUGH TODAY AND TONIGHT.
SOUTH TO SOUTHWEST WINDS WILL BE INCREASING THROUGH THIS AFTERNOON
AS A SURFACE TROUGH DEEPENS OVER THE EASTERN PLAINS. GUSTS UP TO
30 MPH CAN BE EXPECTED BY LATE THIS AFTERNOON. CONVECTION IS
EXPECTED OVER THE FOOTHILLS THIS AFTERNOON WHICH COULD MOVE OUT
OVER THE URBAN CORRIDOR DURING THE EVENING AS THE MAIN UPPER
TROUGH PROGRESSES EASTWARD. GUSTY WINDS BUT LITTLE PRECIPITATION
IS EXPECTED FROM THE HIGH BASED SHOWERS. GUSTS UP TO 40 MPH WILL
BE POSSIBLE WITH THE EARLY EVENING SHOWER ACTIVITY.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...DANKERS
LONG TERM...RPK
AVIATION...DANKERS
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
946 AM EDT SAT APR 23 2016
.UPDATE...DRY CONDITIONS TODAY AS UPPER TROUGH AXIS MOVES
OFFSHORE...WITH MORNING SOUNDINGS SHOWING DRYING CONDITIONS IN
MID/UPR LEVELS. SATELLITE IMAGERY SHOWING WIDESPREAD LOW CLOUD
COVER...WHICH LATEST HRRR MODEL AND LAV GUIDANCE GRADUALLY
DECREASE IN COVERAGE THRU 17Z...AND HAVE UPDATED HOURLY GRIDS TO
REFLECT SLOW CLEARING AND DELAY IN HEATING. STILL EXPECT AFTERNOON
SUNSHINE PUSHING TEMPS UP INTO THE LOW 80S WITH MID 80S IN A FEW
LOCATIONS.
&&
.AVIATION...IFR CONDITIONS EXPECTED TO PERSIST THIS MORNING
BEFORE IMPROVING CONDITIONS MIDDAY...AND HAVE UPDATED TAFS TO
REFLECT THIS EXPECTATION. VFR CONDITIONS THIS AFTERNOON AND
TONIGHT.
&&
.MARINE...NO SIG CHANGES PLANNED IN NEXT CWF ISSUANCE. A FRONTAL
BOUNDARY WILL PUSH THROUGH THE REGION THIS MORNING...WITH WEST TO
NORTHWEST WINDS 10-15 KNOTS THIS MORNING. WINDS WILL BECOME LIGHT
IN THE AFTERNOON THROUGH MIDNIGHT TONIGHT. HIGH PRESSURE WILL
BUILD NORTH OF THE REGION...AND NORTHEASTERLY WINDS WILL INCREASE
LATE TONIGHT THROUGH SUNDAY TO 10-15 KNOTS. HIGH PRESSURE WILL
THEN SHIFT SLOWLY SOUTHEAST ACROSS THE WESTERN ATLANTIC THROUGH
THE MIDDLE OF THE WEEK...WITH WINDS VEERING TO THE SOUTHEAST
MONDAY AND SOUTHWEST BY THE MIDDLE OF THE WEEK. SEAS ARE FORECAST
TO BE GENERALLY IN THE 2-4 FEET RANGE THROUGH THE MIDDLE OF THE
WEEK...EXCEPT 3-5 FEET THIS MORNING BEYOND 20 NM OFFSHORE.
RIP CURRENTS: LOW RISK OF RIP CURRENTS THROUGH THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 82 57 83 59 / 10 0 0 0
SSI 80 64 75 65 / 10 0 0 10
JAX 82 59 80 63 / 10 0 10 10
SGJ 82 65 77 66 / 10 10 10 10
GNV 83 59 84 62 / 10 10 10 10
OCF 82 59 85 63 / 10 10 10 10
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...NONE.
&&
$$
WOLF/SHASHY
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE, IL
1014 AM CDT SAT APR 23 2016
.SHORT TERM...
235 AM CDT
THROUGH SUNDAY
MOSTLY SUNNY SKIES ARE EXPECTED TODAY WITH SIGNIFICANT RANGE IN
TEMPS ACROSS THE AREA RANGING FROM LOWER 50S NEAR THE LAKE TO MID
TO UPPER 60S ONCE YOU GET 50+ MILES INLAND FROM THE LAKE.
SOUTHEAST WINDS WILL LOCK IN TONIGHT WITH WARM AIR ADVECTION
REGIME STARTING IN ADVANCE OF STRONG CYCLONE PROGGED TO MOVE OUT
INTO THE PLAINS TONIGHT. THIS SHOULD KEEP TEMPS FROM GETTING AS
COLD TONIGHT AS THEY ARE THIS MORNING...THOUGH MOST OF THE WARMING
TONIGHT WILL TAKE PLACE ALOFT. STRONGER SOUTHERLY WINDS WILL
DEVELOP SUNDAY AND ALLOW THE WARMTH ALOFT TO MIX TO THE SURFACE
WITH HIGHS LIKELY TOPPING OUT AROUND 80 DEGREES...EVEN ALONG THE
LAKE THANKS TO A STIFF SSW WIND.
IZZI
&&
.LONG TERM...
235 AM CDT
SUNDAY NIGHT THROUGH SATURDAY...
SHOWERS AND THUNDERSTORMS ARE LIKELY TO DEVELOP ALONG A COLD
FRONT FROM MN SOUTH ACROSS IA SOUTH INTO THE EASTERN PLAINS SUNDAY
AFTERNOON. THIS ACTIVITY WILL LIKELY DIMINISH SUNDAY NIGHT AS IT
ATTEMPTS TO MOVE EAST INTO A MORE CAPPED/LESS UNSTABLE AIR MASS
OVER OUR CWA...SO HAVE BACKED OFF ON POPS CONSIDERABLY. THE ECMWF
AND NAM WOULD BOTH FAVOR LITTLE OR NO PRECIP MAKING IT INTO OUR
AREA SUNDAY NIGHT. GUIDANCE HAS GENERALLY TRENDED TOWARD A
SOLUTION OF HANGING THE FRONT UP OVER WISCONSIN MONDAY KEEPING OUR
AREA IN THE BREEZY WARM SECTOR WITH ANOTHER UNSEASONABLY WARM AND
MOSTLY DRY DAY ON TAP. GFS CONTINUES TO PAINT PRECIP ACROSS THE
AREA MONDAY...BUT EVEN IT SHOWS A WEAKENING TREND AND LIKELY IS
OVERDONE WITH LIGHT QPF WITH BOTH ECMWF AND NAM SUGGESTING A
MAINLY DRY DAY. HAVE BACKED OFF ON POPS MONDAY AS A NOD TO THE
EC/NAM SOLUTION...BUT MAINTAINED SOME HIGH END CHANCE POPS DURING
THE AFTERNOON NORTHERN CWA LARGELY TO AVOID DRASTIC CHANGES TO THE
FORECAST.
AS THE WEAKENING SURFACE LOW PASSES ACROSS THE AREA MONDAY
EVENING THE SOUTHERLY FLOW THAT HAD BEEN HOLDING THE LAKE ENHANCED
FRONT TO OUR NORTH WILL COLLAPSE AND SHOULD ALLOW A VERY
IMPRESSIVE BACK DOOR PNEUMONIA FRONT TO COME BARRELING INTO
NE IL WITH A DRAMATIC DROP IN TEMPS MONDAY EVENING...PERHAPS ON
THE ORDER OF 20F+ DEGREES IN A MATTER OF MINUTES. COULD SEE SOME
SCATTERED SHOWERS AND T-STORMS MONDAY EVENING WITH THE FRONT...BUT
GIVEN THE DAMPENING SHORTWAVE ALOFT AND WEAKENING CONVERGENCE KEPT
POPS MODEST AS RAIN DOESNT APPEAR TO BE A SURE THING BY ANY MEANS
AT THIS DISTANCE.
LAKE ENHANCED COOL DOWN EXPECTED TUESDAY WITH DRY CONDITIONS. NEXT
STRONG SHORTWAVE EMANATING FROM THE WESTERN TROUGH IS PROGGED TO
MOVE INTO THE REGION TOWARD MID WEEK. MEDIUM RANGE MODELS FORECAST
THIS WAVE TO BE CLOSED OFF IN THE MID LEVELS AND WOULDNT BE
SURPRISED TO SEE LATER RUNS SLOW THE ARRIVAL OF PRECIP WITH THIS
SYSTEM. REGARDLESS...IT DOES LOOK LIKE A WET PERIOD AS THIS WAVE
MOVES ACROSS THE AREA WED/THUR TIME FRAME. CURRENT INDICATIONS ARE
THE SURFACE FRONT WILL HANG UP TO OUR SOUTH KEEPING MOST OF THE
AREA IN THE COOL SIDE OF THE SYSTEM AND WINDS OFF THE LAKE LOCKED
IN THROUGH THE REST OF THE WORK WEEK KEEPING TEMPS LAKESIDE
CHILLY.
IZZI
&&
.AVIATION...
UPDATED FOR THE 15Z TAFS...
STRATUS CLOUDS CONTINUE TO ERODE...AND EXPECT NEARLY SKC TO ARRIVE
ACROSS ALL AIRFIELDS BY 16Z OR SHORTLY AFTER.
FOR THE 12Z TAFS...
HIGH PRESSURE WILL RESULT IN LIGHT NORTHEAST TO EAST WINDS. WIND
SPEEDS SHOULD REMAIN BELOW 10 KT. SCT-BKN MVFR STRATUS HAS PUSHED
ONSHORE AND REACHED THE TERMINALS. EXPECTING THE STRATUS TO
SCATTER OUT LATE THIS MORNING. SKIES CLEAR AND WINDS BECOME SE
THIS EVENING. WINDS CONTINUE TO VEER TO SOUTH INTO SUNDAY MORNING
WITH INCREASING VFR CLOUDS AHEAD OF THE NEXT SYSTEM. WINDS ALSO
PICK UP SUNDAY MORNING WITH GUSTS BTWN 20-25 KT.
JEE
&&
.MARINE...
221 AM CDT
HEADLINES...WILL LET THE SMALL CRAFT ADVISORY EXPIRE THIS MORNING.
GUSTS MAY APPROACH 25 KT SUNDAY...BUT IT LOOKS LIKE A MARGINAL EVENT
AND HAVE LIMITED CONFIDENCE IN GUSTS 25+ KT. THEREFORE WILL NOT
ISSUE ANOTHER SMALL CRAFT ADVISORY AT THIS TIME.
HIGH PRESSURE OVERHEAD CONTINUES EAST THROUGH SUNDAY. LIGHT AND
VARIABLE WINDS BECOME SOUTHEAST TONIGHT. THE NEXT LOW FORMS OVER THE
PLAINS TONIGHT AND SHIFTS EAST PASSING OVER THE FAR SOUTHERN END OF
THE LAKE OR JUST SOUTH OF THE LAKE MONDAY NIGHT. WINDS BECOME
NORTHEAST TO EAST OVER THE NORTHERN END OF THE LAKE SUNDAY NIGHT AND
MAY INCREASE TO GALE FORCE GUSTS LATE SUNDAY NIGHT INTO MONDAY. WILL
INCLUDE OCNL GALE FORCE GUSTS IN THE GLF...BUT DO NOT HAVE ENOUGH
CONFIDENCE TO ISSUE A GALE WATCH AT THIS TIME. THE SOUTHERN TWO
THIRDS OF THE LAKE WILL SEE SOUTH WINDS TO 25 KT.
A COLD FRONT AHEAD OF HIGH PRESSURE OVER CANADA SINKS SOUTH DOWN THE
LAKE MONDAY NIGHT INTO TUESDAY. WINDS BECOME NORTHEAST BEHIND THE
FRONT AND REMAIN EAST TO NORTHEAST TO 25 KT THROUGH THURSDAY.
ANOTHER LOW PASSES OVER THE LAKE LATE NEXT WEEK. GUIDANCE DIFFERS ON
THE LOW/S PATH AND SPEED...BUT THEY DO AGREE ON HIGH PRESSURE MOVING
IN BEHIND THE LOW.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
[top]
Area Forecast Discussion
National Weather Service Lincoln IL
1011 AM CDT SAT APR 23 2016
.UPDATE...
Issued at 1011 AM CDT Sat Apr 23 2016
Surface Ridge now traversing Illinois with light winds. Stratus
and patchy fog continue to move westward across southeast and
portions of east central Illinois. Expect the edges to begin to
erode as more insolation comes into play and dry air mixes down.
Though models may be dispersing the moisture a little fast given
the strength of the inversion evident in 12z KILX Sounding. Have
made some adjustments to delay clearing and lower high
temperatures in areas that currently have deepest boundary layer
moisture.
A mid deck moving eastward from Iowa may impact KGBG, but it is
moving into very dry air and should dissipate.
&&
.SHORT TERM...(Today)
ISSUED AT 321 AM CDT Sat Apr 23 2016
High pressure centered to our north today will bring pleasant
weather conditions to most of the area. However, a band of lower
clouds over parts of eastern Illinois early this morning was
drifting south-southwest and looks to affect, at least through
the morning hours, our east and southeast areas. As a result, with
the cloud cover expected to hold on into at least the early
afternoon hours, temperatures will be tapered back a bit from
guidance with the cooler afternoon highs (mid to upper 60s) over
the east and especially far southeast counties. while out west,
with full sunshine, we look for afternoon highs in the low to
possibly mid 70s.
.LONG TERM...(Tonight through Friday)
ISSUED AT 321 AM CDT Sat Apr 23 2016
500mb ridge building into the Midwest for the first part of the
weekend will keep the mild weather in place through tonight and into
tomorrow for Central Illinois. After a Sunday with high temps
approaching 80F and increasing southerly winds, the next system will
bring rain chances back to the forecast Sunday night. The overall
shift in the long waves puts the Midwest into an active weather next
week. Some timing differences for the next system Sunday
night...with the GFS the earliest with the onset of rain NW of the
Illinois River Valley before midnight. ECMWF and NAM dry before 12z
Monday morning. NAM actually driest in the bunch for Monday with
very little in the way of QPF, even though it similarly develops the
warm frontal boundary to the north, keeping much of the region in
the warm sector. NAM responds with precip, but delays the more
widespread QPF until the cold front moves through on Monday night.
Forecast will keep the chance mentions Mon-Tue for that round...with
some clearing possible later on Tuesday. But any clearing will be
short lived as a deep low out of the SW develops its surface system
over the southern Plains, driving WAA into the Midwest with a
developing warm front/precip on Tuesday night. Forecast looking wet
through the middle of the week through Thursday with the eventual
passage of the associated sfc low and cold front. Unfortunately, the
larger scale shift to a more progressive and active weather pattern
also means that the break between systems is short, and the next
weekend is also starting to look potentially wet.
&&
.AVIATION...(For the 12Z TAFS through 12Z Sunday morning)
Issued at 600 AM CDT Sat Apr 23 2016
VFR conditions expected over PIA and SPI with some MVFR cigs
possible this morning into the early afternoon hours at CMI
BMI and DEC. Latest satellite data and surface obs continue
to indicate a band of mostly MVFR cigs was located from just
east of CMI and tracking southwest. Latest RAP forecast
soundings indicate the higher probabilities for cigs from
1200-2000 feet AGL would be at CMI to just east of DEC with
BMI more few-sct at 1200 feet. These clouds are expected to
slowly fade as we move into the afternoon hours with more
scattered clouds after 19z in our eastern TAF sites. Surface
winds today will become easterly at 5 to 10 kts and southeast
at 5 to 10 kts tonight.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...Barker
SHORT TERM...Smith
LONG TERM...HJS
AVIATION...Smith
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE, IL
632 AM CDT SAT APR 23 2016
.SHORT TERM...
235 AM CDT
THROUGH SUNDAY
MOSTLY SUNNY SKIES ARE EXPECTED TODAY WITH SIGNIFICANT RANGE IN
TEMPS ACROSS THE AREA RANGING FROM LOWER 50S NEAR THE LAKE TO MID
TO UPPER 60S ONCE YOU GET 50+ MILES INLAND FROM THE LAKE.
SOUTHEAST WINDS WILL LOCK IN TONIGHT WITH WARM AIR ADVECTION
REGIME STARTING IN ADVANCE OF STRONG CYCLONE PROGGED TO MOVE OUT
INTO THE PLAINS TONIGHT. THIS SHOULD KEEP TEMPS FROM GETTING AS
COLD TONIGHT AS THEY ARE THIS MORNING...THOUGH MOST OF THE WARMING
TONIGHT WILL TAKE PLACE ALOFT. STRONGER SOUTHERLY WINDS WILL
DEVELOP SUNDAY AND ALLOW THE WARMTH ALOFT TO MIX TO THE SURFACE
WITH HIGHS LIKELY TOPPING OUT AROUND 80 DEGREES...EVEN ALONG THE
LAKE THANKS TO A STIFF SSW WIND.
IZZI
&&
.LONG TERM...
235 AM CDT
SUNDAY NIGHT THROUGH SATURDAY...
SHOWERS AND THUNDERSTORMS ARE LIKELY TO DEVELOP ALONG A COLD
FRONT FROM MN SOUTH ACROSS IA SOUTH INTO THE EASTERN PLAINS SUNDAY
AFTERNOON. THIS ACTIVITY WILL LIKELY DIMINISH SUNDAY NIGHT AS IT
ATTEMPTS TO MOVE EAST INTO A MORE CAPPED/LESS UNSTABLE AIR MASS
OVER OUR CWA...SO HAVE BACKED OFF ON POPS CONSIDERABLY. THE ECMWF
AND NAM WOULD BOTH FAVOR LITTLE OR NO PRECIP MAKING IT INTO OUR
AREA SUNDAY NIGHT. GUIDANCE HAS GENERALLY TRENDED TOWARD A
SOLUTION OF HANGING THE FRONT UP OVER WISCONSIN MONDAY KEEPING OUR
AREA IN THE BREEZY WARM SECTOR WITH ANOTHER UNSEASONABLY WARM AND
MOSTLY DRY DAY ON TAP. GFS CONTINUES TO PAINT PRECIP ACROSS THE
AREA MONDAY...BUT EVEN IT SHOWS A WEAKENING TREND AND LIKELY IS
OVERDONE WITH LIGHT QPF WITH BOTH ECMWF AND NAM SUGGESTING A
MAINLY DRY DAY. HAVE BACKED OFF ON POPS MONDAY AS A NOD TO THE
EC/NAM SOLUTION...BUT MAINTAINED SOME HIGH END CHANCE POPS DURING
THE AFTERNOON NORTHERN CWA LARGELY TO AVOID DRASTIC CHANGES TO THE
FORECAST.
AS THE WEAKENING SURFACE LOW PASSES ACROSS THE AREA MONDAY
EVENING THE SOUTHERLY FLOW THAT HAD BEEN HOLDING THE LAKE ENHANCED
FRONT TO OUR NORTH WILL COLLAPSE AND SHOULD ALLOW A VERY
IMPRESSIVE BACK DOOR PNEUMONIA FRONT TO COME BARRELING INTO
NE IL WITH A DRAMATIC DROP IN TEMPS MONDAY EVENING...PERHAPS ON
THE ORDER OF 20F+ DEGREES IN A MATTER OF MINUTES. COULD SEE SOME
SCATTERED SHOWERS AND T-STORMS MONDAY EVENING WITH THE FRONT...BUT
GIVEN THE DAMPENING SHORTWAVE ALOFT AND WEAKENING CONVERGENCE KEPT
POPS MODEST AS RAIN DOESNT APPEAR TO BE A SURE THING BY ANY MEANS
AT THIS DISTANCE.
LAKE ENHANCED COOL DOWN EXPECTED TUESDAY WITH DRY CONDITIONS. NEXT
STRONG SHORTWAVE EMANATING FROM THE WESTERN TROUGH IS PROGGED TO
MOVE INTO THE REGION TOWARD MID WEEK. MEDIUM RANGE MODELS FORECAST
THIS WAVE TO BE CLOSED OFF IN THE MID LEVELS AND WOULDNT BE
SURPRISED TO SEE LATER RUNS SLOW THE ARRIVAL OF PRECIP WITH THIS
SYSTEM. REGARDLESS...IT DOES LOOK LIKE A WET PERIOD AS THIS WAVE
MOVES ACROSS THE AREA WED/THUR TIME FRAME. CURRENT INDICATIONS ARE
THE SURFACE FRONT WILL HANG UP TO OUR SOUTH KEEPING MOST OF THE
AREA IN THE COOL SIDE OF THE SYSTEM AND WINDS OFF THE LAKE LOCKED
IN THROUGH THE REST OF THE WORK WEEK KEEPING TEMPS LAKESIDE
CHILLY.
IZZI
&&
.AVIATION...
FOR THE 12Z TAFS...
HIGH PRESSURE WILL RESULT IN LIGHT NORTHEAST TO EAST WINDS. WIND
SPEEDS SHOULD REMAIN BELOW 10 KT. SCT-BKN MVFR STRATUS HAS PUSHED
ONSHORE AND REACHED THE TERMINALS. EXPECTING THE STRATUS TO
SCATTER OUT LATE THIS MORNING. SKIES CLEAR AND WINDS BECOME SE
THIS EVENING. WINDS CONTINUE TO VEER TO SOUTH INTO SUNDAY MORNING
WITH INCREASING VFR CLOUDS AHEAD OF THE NEXT SYSTEM. WINDS ALSO
PICK UP SUNDAY MORNING WITH GUSTS BTWN 20-25 KT.
JEE
&&
.MARINE...
221 AM CDT
HEADLINES...WILL LET THE SMALL CRAFT ADVISORY EXPIRE THIS MORNING.
GUSTS MAY APPROACH 25 KT SUNDAY...BUT IT LOOKS LIKE A MARGINAL EVENT
AND HAVE LIMITED CONFIDENCE IN GUSTS 25+ KT. THEREFORE WILL NOT
ISSUE ANOTHER SMALL CRAFT ADVISORY AT THIS TIME.
HIGH PRESSURE OVERHEAD CONTINUES EAST THROUGH SUNDAY. LIGHT AND
VARIABLE WINDS BECOME SOUTHEAST TONIGHT. THE NEXT LOW FORMS OVER THE
PLAINS TONIGHT AND SHIFTS EAST PASSING OVER THE FAR SOUTHERN END OF
THE LAKE OR JUST SOUTH OF THE LAKE MONDAY NIGHT. WINDS BECOME
NORTHEAST TO EAST OVER THE NORTHERN END OF THE LAKE SUNDAY NIGHT AND
MAY INCREASE TO GALE FORCE GUSTS LATE SUNDAY NIGHT INTO MONDAY. WILL
INCLUDE OCNL GALE FORCE GUSTS IN THE GLF...BUT DO NOT HAVE ENOUGH
CONFIDENCE TO ISSUE A GALE WATCH AT THIS TIME. THE SOUTHERN TWO
THIRDS OF THE LAKE WILL SEE SOUTH WINDS TO 25 KT.
A COLD FRONT AHEAD OF HIGH PRESSURE OVER CANADA SINKS SOUTH DOWN THE
LAKE MONDAY NIGHT INTO TUESDAY. WINDS BECOME NORTHEAST BEHIND THE
FRONT AND REMAIN EAST TO NORTHEAST TO 25 KT THROUGH THURSDAY.
ANOTHER LOW PASSES OVER THE LAKE LATE NEXT WEEK. GUIDANCE DIFFERS ON
THE LOW/S PATH AND SPEED...BUT THEY DO AGREE ON HIGH PRESSURE MOVING
IN BEHIND THE LOW.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FROST ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006 UNTIL 8 AM SATURDAY.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
National Weather Service Lincoln IL
606 AM CDT SAT APR 23 2016
.SHORT TERM...(Today)
ISSUED AT 321 AM CDT Sat Apr 23 2016
High pressure centered to our north today will bring pleasant
weather conditions to most of the area. However, a band of lower
clouds over parts of eastern Illinois early this morning was
drifting south-southwest and looks to affect, at least through
the morning hours, our east and southeast areas. As a result, with
the cloud cover expected to hold on into at least the early
afternoon hours, temperatures will be tapered back a bit from
guidance with the cooler afternoon highs (mid to upper 60s) over
the east and especially far southeast counties. while out west,
with full sunshine, we look for afternoon highs in the low to
possibly mid 70s.
.LONG TERM...(Tonight through Friday)
ISSUED AT 321 AM CDT Sat Apr 23 2016
500mb ridge building into the Midwest for the first part of the
weekend will keep the mild weather in place through tonight and into
tomorrow for Central Illinois. After a Sunday with high temps
approaching 80F and increasing southerly winds, the next system will
bring rain chances back to the forecast Sunday night. The overall
shift in the long waves puts the Midwest into an active weather next
week. Some timing differences for the next system Sunday
night...with the GFS the earliest with the onset of rain NW of the
Illinois River Valley before midnight. ECMWF and NAM dry before 12z
Monday morning. NAM actually driest in the bunch for Monday with
very little in the way of QPF, even though it similarly develops the
warm frontal boundary to the north, keeping much of the region in
the warm sector. NAM responds with precip, but delays the more
widespread QPF until the cold front moves through on Monday night.
Forecast will keep the chance mentions Mon-Tue for that round...with
some clearing possible later on Tuesday. But any clearing will be
short lived as a deep low out of the SW develops its surface system
over the southern Plains, driving WAA into the Midwest with a
developing warm front/precip on Tuesday night. Forecast looking wet
through the middle of the week through Thursday with the eventual
passage of the associated sfc low and cold front. Unfortunately, the
larger scale shift to a more progressive and active weather pattern
also means that the break between systems is short, and the next
weekend is also starting to look potentially wet.
&&
.AVIATION...(For the 12Z TAFS through 12Z Sunday morning)
Issued at 600 AM CDT Sat Apr 23 2016
VFR conditions expected over PIA and SPI with some MVFR cigs
possible this morning into the early afternoon hours at CMI
BMI and DEC. Latest satellite data and surface obs continue
to indicate a band of mostly MVFR cigs was located from just
east of CMI and tracking southwest. Latest RAP forecast
soundings indicate the higher probabilities for cigs from
1200-2000 feet AGL would be at CMI to just east of DEC with
BMI more few-sct at 1200 feet. These clouds are expected to
slowly fade as we move into the afternoon hours with more
scattered clouds after 19z in our eastern TAF sites. Surface
winds today will become easterly at 5 to 10 kts and southeast
at 5 to 10 kts tonight.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Smith
LONG TERM...HJS
AVIATION...Smith
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1041 AM EDT SAT APR 23 2016
.UPDATE...
ISSUED AT 1041 AM EDT SAT APR 23 2016
THE UPPER LEVEL TROUGH AXIS CONTINUES TO SHIFT OFF TO THE
EAST...WITH HEIGHTS RECOVERING THE REST OF THE DAY. SPRINKLES/VERY
LIGHT RAIN SHOWERS HAVE EXITED OUR FAR SOUTHEAST...BUT CLOUDS
LOOK TO HANG TOUGH TODAY AND MODELS ARE A BIT OPTIMISTIC WITH THE
CLEARING COMPARED TO THE VISIBLE SATELLITE TRENDS. GIVEN THE LOW
LEVEL NORTH TO NORTHEAST FLOW AND MAINLY NEUTRAL ADVECTION AT 850
MB...HAVE ALLOWED THE CLOUDS TO HANG ON LONGER. CONSEQUENTLY...
TEMPERATURES ARE ALSO RUNNING A BIT COOLER...SO HAVE LOWERED THE
HIGHS SOMEWHAT...MAINLY LOW TO MID 60S FOR MOST EAST OF
I-75...WITH UPPER 60S TO AROUND 70 WEST OF I-75...WHERE CLEARING
WILL TAKE PLACE THE QUICKEST. UPDATES HAVE BEEN SENT.
UPDATE ISSUED AT 736 AM EDT SAT APR 23 2016
RADAR CONTINUES TO SHOW LIGHT RETURNS ACROSS THE HIGHER TERRAIN
WHERE LOW LEVELS REMAIN SATURATED BENEATH A LOW STRATUS DECK. HAVE
THEREFORE INSERTED SPRINKLES THROUGH MID MORNING AS NOTHING MORE
THAN A TRACE OF PRECIPITATION SHOULD BE POSSIBLE. REDUCED
VISIBILITIES ALSO OCCURRING IN SPOTS...BUT BLANKET OF LOW CLOUDS
SHOULD NEGATE ANY THREAT FOR WIDESPREAD DENSE FOG.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 338 AM EDT SAT APR 23 2016
UPPER TROUGH CURRENTLY PUSHING EAST ACROSS WEST VIRGINIA WILL
BRING DEEP LAYER SUBSIDENCE TO EASTERN KENTUCKY...LEADING TO
GRADUALLY CLEARING SKIES LATER THIS MORNING. BEFORE THEN...A BATCH
OF LOW STRATUS WILL CONTINUE TO PROPAGATE SOUTH ACROSS THE OHIO
VALLEY AND INTO THE COMMONWEALTH AHEAD OF A SURFACE RIDGE BUILDING
ACROSS THE GREAT LAKES AS LOW LEVELS REMAIN RATHER MOIST. THIS
SHOULD KEEP FOG PATCHY IN NATURE AS RADIATIONAL COOLING WILL BE
IMPEDED BY THE INCOMING CLOUD DECK. HOWEVER...NOT EXPECTING ANY
ADDITIONAL RAINFALL WITH UPPER SUPPORT OFF TO THE EAST AND DRYING
MID-UPPER LEVELS.
WILL SEE ALL FOG MIX OUT BY MID-LATE MORNING AS DRIER AIR
CONTINUES TO BUILD TOWARD THE SURFACE. CLOUD COVER WILL ERODE WITH
SKIES CLEARING OUT BY LATER THIS AFTERNOON INTO TONIGHT. LIGHT
NORTHERLY WINDS WILL BRING SUBTLE COOL AIR ADVECTION AND ACT TO
HOLD HIGH TEMPERATURES THIS AFTERNOON IN THE MID 60S TO LOW 70S.
SURFACE HIGH PRESSURE MIGRATING ACROSS THE EASTERN GREAT LAKES
INTO THE APPALACHIANS WILL KEEP SKIES CLEAR TONIGHT AND WINDS
LIGHT. GIVEN RECENT PRECIPITATION FRIDAY...AT LEAST PATCHY VALLEY
FOG SHOULD BE A CERTAINTY AS AN APPRECIABLE RIDGE/VALLEY SPLIT
DEVELOPS. EXPECT A FEW OF THE MORE SHELTERED VALLEY LOCALES TO
DROP INTO THE UPPER 30S WITH MOST RIDGE LOCATIONS GENERALLY IN THE
LOW-MID 40S.
BUILDING HEIGHTS ALOFT AND VEERING SOUTHERLY WINDS WILL LEAD TO A
NOTICEABLE WARMUP FOR SUNDAY AS TEMPERATURES TOP OUT IN THE UPPER
70S TO LOWER 80S.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 338 AM EDT SAT APR 23 2016
OUR WEATHER SHOULD BE MORE ACTIVE NEXT WEEK AS SHORTWAVES EJECT
OUT OF A WESTERN CONUS THROUGH AND TRACK JUST TO OUR WEST INTO THE
UPPER MIDWEST AND GREAT LAKES REGION. AT THE SURFACE...A FRONTAL
BOUNDARY WILL DROP INTO THE REGION BY TUESDAY AND HANG AROUND
THROUGH MIDWEEK. A LOW PRESSURE SYSTEM WILL ALSO GET ORGANIZED
OVER THE PLAINS MIDWEEK. THIS SYSTEM WILL TRACK EASTWARD SENDING A
COLD FRONT TOWARD OUR REGION LATE IN THE WORK WEEK.
SENSIBLE WEATHER WILL FEATURE A NICE WARM MONDAY WITH PLENTY OF
SUNSHINE AND HIGHS IN THE LOW TO MID 80S. THE THREAT FOR SHOWERS
AND THUNDERSTORMS WILL THEN INCREASE FROM NORTH TO SOUTH LATE
MONDAY NIGHT INTO TUESDAY AS THE FRONT DROPS SOUTH INTO THE
REGION. JUST SCATTERED SHOWERS/STORMS ARE ANTICIPATED TUESDAY AND
WEDNESDAY AS THE FRONT IS NOT PARTICULARLY STRONG OR EQUIPPED WITH
MUCH MOISTURE. OUR BEST CHANCE FOR SHOWERS/STORMS APPEARS TO BE
WEDNESDAY NIGHT INTO THE DAY ON THURSDAY AS THE COLD FRONT ENTERS
THE SCENE FROM THE WEST. LESSER RAIN CHANCES ARE FORECAST FOR
FRIDAY...BUT CANNOT REMOVE THEM TOTALLY WITH THE FRONT AND
ACCOMPANYING LOW PRESSURE SYSTEM REMAINING NEARBY PER THE GFS AND
ECMWF.
DESPITE THE DAILY CHANCE OF RAIN TUESDAY THROUGH FRIDAY...A
WIDESPREAD SOAKING RAINFALL APPEARS UNLIKELY AT THIS TIME.
ALSO...DESPITE THE FRONTAL PASSAGE LATE IN THE WEEK...TEMPS WILL
REMAIN WELL ABOVE NORMAL...ONLY DROPPING FROM THE LOW TO MID 80S
TUESDAY THROUGH THURSDAY TO THE MID TO UPPER 70S ON FRIDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 736 AM EDT SAT APR 23 2016
LOW STRATUS CONTINUES TO MAINTAIN GENERALLY MVFR CEILINGS...WITH
ISOLATED LIFR/IFR ALSO POSSIBLE FOR THE NEXT HOUR OR TWO AT
KJKL/KSJS/KSYM. WILL SEE ALL CEILINGS LIFT WITH VFR CONDITIONS
RETURNING BY LATE MORNING. CONTINUED INTRUSION OF DRIER
AIR...THANKS TO HIGH PRESSURE BUILDING IN...WILL CLEAR SKIES
THROUGH THE DAY. LIGHT NORTH WINDS WILL VEER EAST AND SOUTHEAST
THIS EVENING INTO TONIGHT. WILL HAVE TO MONITOR FOG/LOW CEILING
POTENTIAL TONIGHT INTO SUNDAY MORNING WITH CLEAR AND CALM
CONDITIONS IN PLACE...BUT WILL OPT TO KEEP MENTION SILENT FOR NOW
UNTIL SPATIAL/TIMING RESOLUTION BECOME BETTER REFINED.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEOGERIAN
SHORT TERM...GUSEMAN
LONG TERM...ABE
AVIATION...GUSEMAN
[top]
Area Forecast Discussion
National Weather Service Paducah KY
939 AM CDT SAT APR 23 2016
.UPDATE...
Issued at 939 AM CDT Sat Apr 23 2016
Updated for Today due to clouds. Pesky thin layer of low clouds
will remain through much of the morning before mostly dissipating
by early afternoon. Have adjusted today`s max temps down a degree
or two in the central and eastern parts of the FA where cloud
cover is extensive this morning.
&&
.SHORT TERM...(Today through Monday night)
Issued at 304 AM CDT Sat Apr 23 2016
The main issue early this morning is surface high pressure surging
southwest into the region. It is keeping the northeast winds
stirred up and ushering in a solid layer of IFR level clouds that
guidance does not have a good handle on. The clouds now cover much
of the Evansville Tri State, and should continue to push
southward, per the RAP low-level RH forecast, toward the Lakes and
Pennyrile. Figure that the low clouds will dissipate quickly this
morning by 15Z.
The clouds will have more of an impact on aviation concerns, and
the AVIATION of this discussion has been updated as well.
Temperatures may be held up just a bit under the cloud cover
through daybreak, but not much, and they may hold down highs a
degree or two in the east. With plenty of sunshine expected this
afternoon and dry air in place over the region, this forecast still
leaned toward the warmer side of the guidance envelope for highs.
Surface high pressure will continue to dominate the region tonight,
so clear skies and light winds will allow for good radiational
cooling. Definitely went at or below coolest guidance for tonight`s
lows in most locations. The surface high will push east of the
area on Sunday, allowing south winds to return across the region.
With high pressure aloft resulting in mostly sunny skies, went at
or above the warmest guidance. Most of the area should be in the
lower 80s.
South winds will stay up in the 5 to 10 mph range Sunday night, so
it should be a milder night. Skies will still be no worse than
partly cloudy, so will not go much above guidance. Lows should be
around 60.
As our next potential storm system settles over the Four Corners
region Monday, the flow aloft over our region will become nearly
zonal. A surface cold front will become strung out nearly west to
east well to our north. This should keep us high and dry Monday
and most likely Monday night, too. Will have the slightest of PoPs
for SHRA/TSRA in the Perryville, Pinckneyville, and Mt Vernon
areas on Monday and along the I-64 corridor Monday night, but this
is mainly just to provide a buffer with our surrounding forecast
areas.
The 00Z models do not indicate much increase in clouds Monday, so
temperatures should soar into the 80-85F range, which is well above
guidance. Lows Monday night will continue to trend milder. With a
bit more wind expected, and increasing clouds overnight, lows will
be in the 60-65F range.
.LONG TERM...(Tuesday through Friday)
Issued at 304 AM CDT Sat Apr 23 2016
The upper-level split flow pattern will consist of an active
southern stream across the United States, and a more diffuse polar
jet across northern Canada. A series of shortwaves will eject
northeast out of the Desert Southwest to the central Plains, then
finally into the Great Lakes before weakening. There are still
significant model differences concerning the timing of these
shortwaves and their associated frontal systems. Overall, the
pattern looks rather warm and wet given the storm track to our
north.
As far as the daily specifics, the models are in good agreement for
Tuesday. A narrow 500 mb ridge will pass over the Mississippi Valley
ahead of the first shortwave, which will be emerging into the
southern high Plains. Beneath the ridge aloft, the models continue
to sag a weak frontal boundary south to Interstate 64 by late in the
day Tuesday. The air mass is forecast to be warm and unstable south
of the front, moreso than with other fronts this spring. Therefore,
chance pops will be kept in the forecast despite weak forcing aloft.
The weak frontal boundary should continue south into the Lower Ohio
Valley Tuesday night. Beyond that, the models really start to
diverge on the timing of subsequent frontal passages. The front may
move south of our area before returning north as a warm front during
the middle of the week. A weakening surface low will then move east
across the Midwest Wednesday night and Thursday. A cold front
trailing southwest from the low will move across our region, but
timing differences are quite large. The faster 00z ecmwf is
consistent with the previous NWS forecast and the 12z Fri ecmwf
ensemble mean. However, the slower 00z gfs has support from the
00z gefs. In a nutshell, pops will be in the high chance to likely
category Wed and Wednesday night. Compared with previous systems
this spring, there will be plenty of moisture and instability for
convection. Wind profiles will be moderately strong. A few intense
storms are possible.
Late in the week, another weak shortwave ridge will traverse the
Mississippi and Ohio Valleys between systems. The weak cold front
will be suppressed south of our region. It now appears Friday will
be dry in many areas, but a slight chance pop will be retained
closer to the frontal boundary in the Tennessee border counties
and much of se Missouri. Temperatures should be a little cooler
north of the front, with highs Friday from 70 to 75.
&&
.AVIATION...
Issued at 639 AM CDT Sat Apr 23 2016
The IFR/LIFR ceilings reached all of the TAF sites except KCGI,
but MVFR visibilities were impacting the entire area. The low
clouds and fog should dissipate fairly quickly now that the sun is
up. It may take most of the morning for KOWB and KEVV to burn off.
Otherwise, the only potential concern to aviation is a possible
recurrence of fog or low cloud development late tonight. The
surface high is expected to shift eastward a bit, which will
hopefully keep any such development east of the TAF sites.
&&
.PAH Watches/Warnings/Advisories...
IL...None.
MO...None.
IN...None.
KY...None.
&&
$$
UPDATE...RS
SHORT TERM...DRS
LONG TERM...MY
AVIATION...DRS
AREA FORECAST DISCUSSION
NWS JACKSON KY
736 AM EDT SAT APR 23 2016
.UPDATE...
ISSUED AT 736 AM EDT SAT APR 23 2016
RADAR CONTINUES TO SHOW LIGHT RETURNS ACROSS THE HIGHER TERRAIN
WHERE LOW LEVELS REMAIN SATURATED BENEATH A LOW STRATUS DECK. HAVE
THEREFORE INSERTED SPRINKLES THROUGH MID MORNING AS NOTHING MORE
THAN A TRACE OF PRECIPITATION SHOULD BE POSSIBLE. REDUCED
VISIBILITIES ALSO OCCURRING IN SPOTS...BUT BLANKET OF LOW CLOUDS
SHOULD NEGATE ANY THREAT FOR WIDESPREAD DENSE FOG.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 338 AM EDT SAT APR 23 2016
UPPER TROUGH CURRENTLY PUSHING EAST ACROSS WEST VIRGINIA WILL
BRING DEEP LAYER SUBSIDENCE TO EASTERN KENTUCKY...LEADING TO
GRADUALLY CLEARING SKIES LATER THIS MORNING. BEFORE THEN...A BATCH
OF LOW STRATUS WILL CONTINUE TO PROPAGATE SOUTH ACROSS THE OHIO
VALLEY AND INTO THE COMMONWEALTH AHEAD OF A SURFACE RIDGE BUILDING
ACROSS THE GREAT LAKES AS LOW LEVELS REMAIN RATHER MOIST. THIS
SHOULD KEEP FOG PATCHY IN NATURE AS RADIATIONAL COOLING WILL BE
IMPEDED BY THE INCOMING CLOUD DECK. HOWEVER...NOT EXPECTING ANY
ADDITIONAL RAINFALL WITH UPPER SUPPORT OFF TO THE EAST AND DRYING
MID-UPPER LEVELS.
WILL SEE ALL FOG MIX OUT BY MID-LATE MORNING AS DRIER AIR
CONTINUES TO BUILD TOWARD THE SURFACE. CLOUD COVER WILL ERODE WITH
SKIES CLEARING OUT BY LATER THIS AFTERNOON INTO TONIGHT. LIGHT
NORTHERLY WINDS WILL BRING SUBTLE COOL AIR ADVECTION AND ACT TO
HOLD HIGH TEMPERATURES THIS AFTERNOON IN THE MID 60S TO LOW 70S.
SURFACE HIGH PRESSURE MIGRATING ACROSS THE EASTERN GREAT LAKES
INTO THE APPALACHIANS WILL KEEP SKIES CLEAR TONIGHT AND WINDS
LIGHT. GIVEN RECENT PRECIPITATION FRIDAY...AT LEAST PATCHY VALLEY
FOG SHOULD BE A CERTAINTY AS AN APPRECIABLE RIDGE/VALLEY SPLIT
DEVELOPS. EXPECT A FEW OF THE MORE SHELTERED VALLEY LOCALES TO
DROP INTO THE UPPER 30S WITH MOST RIDGE LOCATIONS GENERALLY IN THE
LOW-MID 40S.
BUILDING HEIGHTS ALOFT AND VEERING SOUTHERLY WINDS WILL LEAD TO A
NOTICEABLE WARMUP FOR SUNDAY AS TEMPERATURES TOP OUT IN THE UPPER
70S TO LOWER 80S.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 338 AM EDT SAT APR 23 2016
OUR WEATHER SHOULD BE MORE ACTIVE NEXT WEEK AS SHORTWAVES EJECT
OUT OF A WESTERN CONUS THROUGH AND TRACK JUST TO OUR WEST INTO THE
UPPER MIDWEST AND GREAT LAKES REGION. AT THE SURFACE...A FRONTAL
BOUNDARY WILL DROP INTO THE REGION BY TUESDAY AND HANG AROUND
THROUGH MIDWEEK. A LOW PRESSURE SYSTEM WILL ALSO GET ORGANIZED
OVER THE PLAINS MIDWEEK. THIS SYSTEM WILL TRACK EASTWARD SENDING A
COLD FRONT TOWARD OUR REGION LATE IN THE WORK WEEK.
SENSIBLE WEATHER WILL FEATURE A NICE WARM MONDAY WITH PLENTY OF
SUNSHINE AND HIGHS IN THE LOW TO MID 80S. THE THREAT FOR SHOWERS
AND THUNDERSTORMS WILL THEN INCREASE FROM NORTH TO SOUTH LATE
MONDAY NIGHT INTO TUESDAY AS THE FRONT DROPS SOUTH INTO THE
REGION. JUST SCATTERED SHOWERS/STORMS ARE ANTICIPATED TUESDAY AND
WEDNESDAY AS THE FRONT IS NOT PARTICULARLY STRONG OR EQUIPPED WITH
MUCH MOISTURE. OUR BEST CHANCE FOR SHOWERS/STORMS APPEARS TO BE
WEDNESDAY NIGHT INTO THE DAY ON THURSDAY AS THE COLD FRONT ENTERS
THE SCENE FROM THE WEST. LESSER RAIN CHANCES ARE FORECAST FOR
FRIDAY...BUT CANNOT REMOVE THEM TOTALLY WITH THE FRONT AND
ACCOMPANYING LOW PRESSURE SYSTEM REMAINING NEARBY PER THE GFS AND
ECMWF.
DESPITE THE DAILY CHANCE OF RAIN TUESDAY THROUGH FRIDAY...A
WIDESPREAD SOAKING RAINFALL APPEARS UNLIKELY AT THIS TIME.
ALSO...DESPITE THE FRONTAL PASSAGE LATE IN THE WEEK...TEMPS WILL
REMAIN WELL ABOVE NORMAL...ONLY DROPPING FROM THE LOW TO MID 80S
TUESDAY THROUGH THURSDAY TO THE MID TO UPPER 70S ON FRIDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 736 AM EDT SAT APR 23 2016
LOW STRATUS CONTINUES TO MAINTAIN GENERALLY MVFR CEILINGS...WITH
ISOLATED LIFR/IFR ALSO POSSIBLE FOR THE NEXT HOUR OR TWO AT
KJKL/KSJS/KSYM. WILL SEE ALL CEILINGS LIFT WITH VFR CONDITIONS
RETURNING BY LATE MORNING. CONTINUED INTRUSION OF DRIER
AIR...THANKS TO HIGH PRESSURE BUILDING IN...WILL CLEAR SKIES
THROUGH THE DAY. LIGHT NORTH WINDS WILL VEER EAST AND SOUTHEAST
THIS EVENING INTO TONIGHT. WILL HAVE TO MONITOR FOG/LOW CEILING
POTENTIAL TONIGHT INTO SUNDAY MORNING WITH CLEAR AND CALM
CONDITIONS IN PLACE...BUT WILL OPT TO KEEP MENTION SILENT FOR NOW
UNTIL SPATIAL/TIMING RESOLUTION BECOME BETTER REFINED.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GUSEMAN
SHORT TERM...GUSEMAN
LONG TERM...ABE
AVIATION...GUSEMAN
Area Forecast Discussion
National Weather Service Louisville KY
651 AM EDT SAT APR 23 2016
...Updated Aviation Discussion...
.SHORT TERM (Now through Sunday)...
Issued 240 AM EDT Sat Apr 23 2016
...A pleasant weekend in store...
The synoptic pattern early this morning features a weak trough
across the eastern CONUS, with another more substantial trough
building into the western CONUS. Ridging in between these two
features will build into the Ohio Valley through the period,
bringing a very pleasant weekend to the region.
Low clouds continue to stream in from the north early this morning.
The latest HRRR has a pretty good handle on these clouds, thus have
leaned toward its solution for today. These clouds should mix out
pretty quickly by mid to late morning, making way for quite a bit of
sunshine this afternoon. The clouds may slow our temperatures rise
a bit this morning, but think the solar insolation this afternoon
should be enough to get temperatures into the upper 60s and lower
70s.
Surface ridging will slide east of the region tonight into Sunday.
Southerly flow will commence on the backside of this high, which
will allow temperatures to warm up for Sunday. Will go above the
general guidance consensus, which places highs in the lower 80s
under mostly sunny skies.
.LONG TERM (Sunday night through Friday)...
Issued at 310 AM EDT Sat Apr 23 2016
...A more active convective weather pattern at times next week...
The synoptic pattern at the start of the long term period will
feature zonal to WSW flow over the Ohio Valley due to an upstream
western CONUS trough. This regime will allow for a couple of
disturbances to eject out of the trough which will make for a more
active weather pattern beginning around Monday night/Tuesday of next
week.
While confidence in the overall pattern is high, confidence in
timing of each feature ejecting out of the western trough is rather
low. As a result, have gone with more of an ensemble approach to
the forecast and stuck with a general model/ensemble blend.
A warm front will sharpen well to the north of the region on Monday.
As a result, any precipitation will remain out of the Ohio Valley
which will allow us to warm rather nicely during the afternoon hours
as we will sit on the warm side of the boundary. Have upper highs
well into the 80s on Monday afternoon, with some upper 80s readings
not out of the question in the typically warmer locations.
The first PV anomaly will slide southeast along the front Monday
night into Tuesday. This will help push the front into the Ohio
River Valley, sparking showers and thunderstorms as it drives
southeast. The kinematics with this system are not impressive, with
deep layer shear only around 20-30 knots, so do not see an organized
severe threat with this activity on Tuesday (maybe just a few strong
storms depending on how well we destabilize).
The western trough will begin to eject into the Central Plains late
Tuesday into Wednesday, which will push the cold front back to the
north as a warm front. A few thunderstorms will be possible
Wednesday along/south of the boundary lifting north, but it appears
the better chance of thunderstorms will come mainly Wednesday night
as the main forcing for ascent pushes through the Ohio Valley. Wind
fields are more impressive with this system, but timing as it stands
now is not very favorable. However, we will continue to monitor
this system closely as substantial differences remain in the
deterministic/ensemble guidance suite.
The GFS is much slower, keeping storm chances going through
Thursday, with the ECMWF showing a much drier solution. Will split
the difference and continue with chance pops Thursday, but go mainly
dry for Friday as the guidance consensus is to finally push the cold
front to the south of the region.
Temperatures through the period will be very dependent on the timing
of precipitation, but highs generally in the 80s with lows in the
upper 50s/60s is likely through much of next week, until the
slightly cooler air arrives Friday.
&&
.AVIATION (12Z TAF Update)...
Updated at 650 AM EDT Sat Apr 23 2016
Batch of low level clouds will continue to drop southward through KY
this morning. Ceilings are expected to run around 1-1.5Kft AGL this
morning with a light northerly wind. Some light fog will also be
possible for a time this morning. Overall visibilities should run
in the MVFR range with 4-5SM expected. The low cloud deck is
forecast to mixout around 23/14-16Z with VFR conditions expected at
all the terminals after 23/17Z. VFR conditions are expected this
afternoon and tonight with just a light northeasterly breeze.
&&
.LMK Watches/Warnings/Advisories...
KY...NONE.
IN...NONE.
&&
$$
Short Term........KJD
Long Term.........KJD
Aviation..........MJ
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1034 AM CDT SAT APR 23 2016
.UPDATE...
ISSUED AT 1034 AM CDT SAT APR 23 2016
UPDATED THE FORECAST THROUGH EARLY SUNDAY...MAINLY FOCUSING ON THE
TIMING OF THE PRECIPITATION. LEANED ON THE EXPERIMENTAL HRRR AND
RAP13 FOR THE BLEND BECAUSE THE TWO MODELS WERE PERFORMING THE
BEST WITH WHAT WAS OCCURRING EARLIER THIS MORNING. BOTH THE HRRR
AND RAP13 WERE REFLECTING THE BAND OF SHOWERS ACROSS THE WEST
CENTRAL FORECAST AREA...THEN LIFTING THE BAND NORTH AND EAST INTO
THIS AFTERNOON. MUCH OF THE PCPN THIS AFTERNOON SHOULD BE LIMITED
TO FAR NORTHERN MINNESOTA...AND THEN ONLY BEGIN TO SPREAD INTO THE
REST OF THE NORTHLAND LATE TODAY.
THE PREVIOUS FORECAST HAD SLEET AND FREEZING RAIN OVER THE
ARROWHEAD TONIGHT AND EARLY SUNDAY. HOWEVER...THE LATEST
RAP13/NAM12/GFS20 MODEL SOUNDINGS HEAVILY FAVOR ONLY RAIN OR
SNOW...SO REMOVED THE SLEET AND FREEZING RAIN. THE PREVIOUS
FORECAST ALSO HAD A MIXTURE OF RAIN AND SNOW FOR THE LAKE SUPERIOR
AREA SUNDAY AFTERNOON...BUT THE TEMPERATURES ALOFT HEAVILY SUPPORT
RAIN. WHILE COLD NEAR SURFACE TEMPERATURES MAY APPROACH THE
FREEZING MARK...THE RELATIVELY WARM TEMPERATURES ALOFT SHOULD
ENSURE THE FALLING PCPN REMAINS RAIN.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 401 AM CDT SAT APR 23 2016
THE SHORT TERM FORECAST FOCUS WILL BE ON PRECIPITATION CHANCES/TYPE
THROUGH SUNDAY.
A SURFACE LOW IN EASTERN MONTANA IS FORECAST TO MOVE SOUTHEAST INTO
SOUTH DAKOTA BY 12Z SUNDAY THEN MOVE ONLY SLOWLY EAST ON SUNDAY.
MOISTURE WILL SURGE INTO THE NORTHLAND TODAY INTO SUNDAY WITH PWAT
VALUES INCREASING FROM A THIRD TO HALF INCH OVER THE AREA THIS
MORNING...TO THREE QUARTERS TO NEAR AN INCH AND A QUARTER BY 12Z
SUNDAY. PERSISTENT WAA/FGEN AS WELL AS SHORTWAVE ENERGY TODAY INTO
SUNDAY WILL CAUSE PRECIPITATION TO INCREASE ACROSS THE NORTHLAND.
PRECIPITATION WILL BECOME WIDESPREAD TONIGHT INTO SUNDAY. A
STRONG GRADIENT WITH PRESSURE FALLS OFF TO THE SOUTHWEST WILL
CAUSE THE WIND TO INCREASE AROUND LAKE SUPERIOR...WITH STRONG
WINDS OVER AND CLOSE TO LAKE SUPERIOR DEVELOPING LATER TONIGHT
INTO MONDAY.
PRECIPITATION TYPE WILL BE A CHALLENGE OVER PORTIONS OF THE
NORTHLAND...MAINLY TONIGHT INTO SUNDAY IN THE ARROWHEAD TO THE HEAD
OF LAKE SUPERIOR. JUST SHOWERS ARE EXPECTED TODAY AS THE BOUNDARY
LAYER WARMS...BUT TONIGHT THE LOW LEVELS WILL COOL AROUND PORTIONS
OF LAKE SUPERIOR AND WITH INCREASING EAST/NORTHEAST
WINDS...ADDITIONAL COOLING CAN BE EXPECTED AROUND THE LAKE. FORECAST
SOUNDINGS AND SURFACE TEMPERATURES SUGGEST A MIX FROM RAIN OR SNOW
TO SLEET OR EVEN SOME FREEZING RAIN WILL BE POSSIBLE LATER TONIGHT
INTO SUNDAY MORNING OVER PORTIONS OF THE ARROWHEAD. AT THIS
TIME...IT LOOKS LIKE TEMPERATURES THROUGH SUNDAY MORNING WILL REMAIN
WARM ENOUGH FOR JUST RAIN IN THE TWIN PORTS AND SOUTH SHORE AREAS. A
MIX MAY DEVELOP LATE SUNDAY AFTERNOON/EVENING AT THE HEAD OF LAKE
SUPERIOR AS STRONG EASTERLY FLOW AND PERSISTENT RAIN COOLS SURFACE
TEMPERATURES IN THOSE AREAS. AT THIS TIME...SIGNIFICANT ICE IS NOT
EXPECTED...BUT IF SURFACE TEMPERATURES HAPPEN TO COOL ABOUT 2 OR 3
DEGREES MORE THAN EXPECTED...THERE COULD BE SOME ICING THAT DEVELOPS.
SIGNIFICANT RAINFALL IS EXPECTED THROUGH MONDAY...WITH AMOUNTS
RANGING FROM A THIRD OF AN INCH ALONG THE INTERNATIONAL BORDER...TO
1.5 TO 2.5 INCHES FROM THE TWIN PORTS AND OVER NORTHERN WISCONSIN.
WE EXPECT HIGHS TODAY TO RANGE FROM THE LOWER TO MID SIXTIES IN THE
BRAINERD LAKES INTO NORTHWEST WISCONSIN...TO THE LOWER FIFTIES OVER
FAR NORTHERN MINNESOTA. INCREASING WINDS OFF OF LAKE SUPERIOR WILL
KEEP ALL AREAS AROUND THE LAKE MUCH COOLER...WITH ONLY LOWER TO MID
FORTIES EXPECTED. SUNDAY WILL BE EVEN COOLER WITH STRONGER WINDS.
THE LAKE INFLUENCE WILL BE FELT WELL INLAND TO MOOSE LAKE...SOLON
SPRINGS AND IRON RIVER...AND WELL INTO THE ARROWHEAD. TEMPERATURES
HERE WILL ONLY BE IN THE THIRTIES...WITH MID FORTIES TO LOWER
FIFTIES ELSEWHERE.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 401 AM CDT SAT APR 23 2016
PRECIPITATION WILL CONTINUE SUNDAY NIGHT AND MONDAY WITH THE STRONG
SURFACE LOW SLOWLY MOVING FROM CENTRAL SOUTH DAKOTA...EAST TO
NORTHWEST IOWA BY EARLY MONDAY MORNING AND ON TO NORTHWEST ILLINOIS
BY MONDAY EVENING. STRONG FRONTOGENESIS AND ISENTROPIC LIFT WILL
CONTINUE ACROSS THE SOUTHERN HALF OF THE FORECAST AREA SUNDAY NIGHT
THROUGH MONDAY. FOR NOW...IT APPEARS THE GREATEST POPS SHOULD BE
SUNDAY NIGHT...GRADUALLY DIMINISHING THROUGH MONDAY. EASTERLY FLOW
OFF LAKE SUPERIOR AND COLDER...DRIER AIR MOVING IN FROM THE AREA
FROM THE NORTHEAST MAY TURN THE PRECIPITATION OVER TO A WINTRY MIX
ALONG THE NORTH SHORE OR FARTHER INLAND NORTH OF THE IRON RANGE.
SURFACE TEMPERATURES WILL BE CRITICAL DURING THIS TIME RANGE...AND
THERE IS SOME POTENTIAL FOR FREEZING RAIN. HAVE LEFT THE FREEZING
RAIN OUT OF THE FORECAST FOR THESE PERIODS FOR NOW...BUT WILL HAVE
TO RE-EVALUATE THIS OVER THE NEXT DAYS. MONDAY NIGHT THE
PRECIPITATION WILL GRADUALLY END FROM WEST TO EAST...LEAVING DRY
CONDITIONS FOR TUESDAY...WITH WARMER CONDITIONS FOR TUESDAY THAN
MONDAY.
TUESDAY NIGHT THROUGH FRIDAY THERE ARE SOME SIGNIFICANT DIFFERENCES
IN THE MODELS. A STRONG UPPER LOW OVER THE PLAINS WILL GRADUALLY
MOVE EAST THROUGH THE PERIOD...WITH THE GFS KEEPING THE LOW TIGHTER
AND FARTHER TO THE NORTH THAN THE MORE OPEN AND FASTER MOVING ECMWF.
THE GFS SOLUTION KEEPS PRECIPITATION GOING OVER THE FORECAST AREA
WEDNESDAY THROUGH THURSDAY NIGHT...WHERE THE ECMWF KEEPS US DRY
THROUGH MUCH OF THE PERIOD WITH THE UPPER LOW TOO FAR NORTH TO
AFFECT US. THIS FARTHER NORTH GFS SOLUTION IS RELATIVELY NEW...AS
PREVIOUS SOLUTIONS ALSO KEPT THIS UPPER LOW TOO FAR SOUTH TO AFFECT
THE FORECAST AREA. HAVE KEPT TO THE BLENDED SOLUTION FOR POPS...BUT
WE MAY BE ABLE TO LOWER THEM AGAIN. TEMPERATURES GRADUALLY WARM
THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 642 AM CDT SAT APR 23 2016
VFR CONDITIONS THIS MORNING ARE EXPECTED TO CONTINUE UNTIL
APPROXIMATELY 03Z THIS EVENING. AFTER 03Z AN AREA OF MVFR CEILINGS
WILL SPREAD INTO THE AREA FROM THE WEST WITH SCATTERED SHOWERS.
THESE CEILINGS WILL GRADUALLY LOWER TO IFR FOR KDLH...KHIB...KBRD
AND KHYR WITH MVFR VISIBILITIES IN LIGHT RAIN. KINL TO REMAIN
MVFR. THUNDER IS ALSO POSSIBLE FOR KBRD...KDLH AND KHYR AFTER 00Z
THIS EVENING...THOUGH HAVE LEFT OUT OF THE SPECIFIC TERMINAL
FORECAST FOR NOW DUE TO UNCERTAINTIES IN TIMING.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 48 35 37 32 / 10 80 80 90
INL 52 36 50 30 / 60 60 10 10
BRD 65 44 45 37 / 40 70 70 90
HYR 62 46 50 38 / 0 70 90 90
ASX 55 39 41 35 / 10 80 90 90
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...GALE WATCH FROM SUNDAY MORNING THROUGH MONDAY AFTERNOON FOR
LSZ140>147.
SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 10 AM CDT
SUNDAY FOR LSZ143>146.
&&
$$
UPDATE...GROCHOCINSKI
SHORT TERM...MELDE
LONG TERM...LE
AVIATION...LE
Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
653 AM CDT SAT APR 23 2016
.SHORT TERM... (Through Late This Afternoon)
Issued at 350 AM CDT Sat Apr 23 2016
Focus today will be clouds and temps.
Sfc ridge will continue to drift ewd today, allowing sly winds to
return to wrn portions of the CWA. Winds elsewhere are expected to
remain sely to ely.
The area of clouds currently just E of the CWA shud remain E.
However, some clouds may drift into ern portions of the CWA mainly
this morning until the ridge pushes them out of the area.
A secondary ridge axis over nrn portions of the CWA is expected to
be the focus for FG/stratus this morning. There is still uncertainty
regarding how widespread any FG will be, as well as any stratus. The
additional moisture within the bndy layer across this region shud
allow for at least sct clouds this morning, dissipating thru the
afternoon.
All of this leads to a rather complex temp forecast for today. For
ern portions of the CWA, have kept temps cooler where the ridge axis
will remain in place longer. Areas under this ridge yesterday saw
temps in the upper 60s, however, believe there will be less cloud
cover today. Believe the warmer temps will build into wrn portions
of the CWA where winds will become sly as well as the thermal ridge
building into this area. Have gone with trends close to a blend of
the RAP and local 4km WRF, which has been a good mix in these
setups. Did trend slightly cooler than this blend across nrn
portions of the CWA where more questions exist regarding cloud cover
today.
Tilly
.LONG TERM... (Tonight through Friday)
Issued at 350 AM CDT Sat Apr 23 2016
An upper level longwave RIDGE axis will persist over the Plains
thru much of next week, with upper longwave TROFs on the west and
east coasts. A series of strong Pacific storms will run thru this
RIDGE, being dropped off from the west coast TROF and being picked
up by the east coast TROF a few days later, with an overall track to
the E-NE thru our region. It would seem that each successive storm
system will track a bit further south than its predecessor.
The first storm system is slated to track to our north late Sunday
and into Monday, and will be mostly a glancing blow to our region as
a result, with what forms mostly upstream initially to our northwest
as it is thrown in our direction and largely weakens as it moves in.
This convection may also create additional boundaries during Monday
afternoon and early evening to maintain the threat for showers and
thunderstorms.
In the wake of this first storm system, a cold front will drop down
late Monday night into Tuesday and will maintain a low chance for
rain.
The second Pacific storm system will be more of a direct hit as it
will initially correspond well with the surface frontal boundary
buckling north as a warm front Wednesday morning. This should
result in elevated storms with hail as their primary threat during
that time.
Heading into Wednesday afternoon and evening, it will depend heavily
on how far north the front gets. Models have been trending with
less northward progress from 24hrs ago, but anywhere to the south of
it will have plenty of instability and moisture as well as strong
shear for more surface-based storms which will have a good potential
for some severe.
The rain potential lingers into Thursday if the cold front slows
enough to not make it thru until this day.
Friday should be a dry day, finally, but it appears only briefly
until yet another storm system approaches from the west in time for
the following weekend.
Otherwise, the longwave RIDGE setup will ensure that temps remain at
or above average throughout the period.
TES
&&
.AVIATION... (For the 12z TAFs through 12z Sunday Morning)
Issued at 640 AM CDT Sat Apr 23 2016
Sfc ridge is expected to push ewd today with winds eventually
becoming sely. The lingering FG this morning is expected to
dissipate quickly this morning. Some uncertainty regarding the
area of stratus over ern IA into far nern MO. This stratus may
develop far enuf sewd to impact UIN this morning. However, with
the sun rising and the slow pace the stratus is moving, do not
currently expect it to impact the terminal. Expect winds to
continue to veer this evening, with a LLJ creating LLWS concerns
at COU/UIN tonight.
Specifics for KSTL: VFR and dry conditions expected thru the TAF
period.
Tilly
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...None.
IL...None.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
621 AM CDT SAT APR 23 2016
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 320 AM CDT SAT APR 23 2016
THE PRIMARY FCST CONCERNS CONTINUE TO BE TSTM CHANCES FROM TONIGHT
INTO MONDAY AND TEMPS.
UPPER AIR CHARTS FROM LAST EVENING HAD THE FOLLOWING FEATURES OF
INTEREST. AT 850 MB...A RIDGE WAS IN PLACE FROM TX INTO MN. MOISTURE
AT THIS LEVEL WAS MAINLY CONFINED TO SOUTH TEXAS AND THE GULF
COASTAL REGION. A RIDGE WAS ALSO IN ABOUT THE SAME AREA AT 700 MB
...WITH A TROUGH TO THE WEST. AT 500 MB...A TROUGH WAS OVER THE
WRN UNITED STATES...WITH 12 HOUR HEIGHT FALLS OF UP TO 90 METERS
AT KOAK IN CA. A JET MAX OF AROUND 110 KTS WAS STILL OUT OVER THE
PACIFIC AT 300 MB...ON THE BACKSIDE OF THE TROUGH. LATEST WATER
VAPOR AND IR STLT IMAGERY SHOWED JUST SOME CIRRUS LOCALLY...WITH
AREAS OF FOG TO THE EAST IN IA AND THICKER MID LEVEL CLOUDS OVER
THE ROCKIES. AT THE SFC...A RIDGE WAS TO OUR EAST AND A TROUGH TO
THE WEST...FROM ERN MT INTO ERN CO. S OR SE WINDS WERE NOTED WITH
DEWPOINTS IN THE 40S. THE KOAX SOUNDING FROM LAST EVENING ONLY HAD
ABOUT 0.33 PW. THERE WAS SOME BETTER MOISTURE TO OUR S.
TODAY...WILL PROBABLY KEEP THE FCST DRY. THE 00Z NAM AND EVEN SOME
RECENT RAP MODEL RUNS TRIED TO DVLP ISOLD LGT PCPN OVER PARTS OF
THE AREA THIS MORNING. 06Z NAM AND MOST OF THE RECENT EXPERIMENTAL
HRRR RUNS DID NOT SHOW ANY PCPN. AS THE PRES GRADIENT TIGHTENS
TODAY...IT WILL BECOME BREEZY OR WINDY. PREVIOUS FCST HIGHS LOOKED
PRETTY GOOD...MAINLY 75 TO 80...SO CHANGES WERE MINOR.
PCPN CHANCES WILL BE INCREASING TONIGHT. GENLY FELT THAT MUCH OF
THE EVENING WOULD BE DRY...DESPITE SOME PCPN SHOWN BY THE GFS.
OTHER MODELS KEEP BEST PCPN CHANCES W OF OUR AREA UNTIL AFTER
MIDNIGHT. POPS MAINLY FROM 20-30 PCT SEEM PRUDENT BASED ON THE
MOISTURE RETURN AND FORCING. TREND SHOULD BE FOR PCPN TO TRY TO
DIE OUT SUN MORNING...THEN REDEVELOP IN THE AFTN. THERE IS FAIRLY
GOOD MODEL AGREEMENT ON THAT. SPC DAY 2 OTLK SHOWS SLGT CHANCE OF
SVR AND BASED ON INSTABILITY AND SHEAR FCSTS...THAT LOOKS RIGHT.
BOUNDARY LAYER CAPE VALUES UP TO ABOUT 1500 J/KG SEEM PSBL. THE
HIGHEST TSTM CHANCES WILL BE ACRS ABOUT THE SERN 1/2 OF THE FCST
AREA. LOOK FOR LOWS TNGT 55 TO 60 AND HIGHS SUN MOSTLY MID OR
UPPER 70S.
A FRONT WILL MOVE DOWN THROUGH THE AREA MON...BUT LIFT LOOKS WEAK
SO HAVE KEPT POPS BELOW 15 PCT FOR NOW.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 320 AM CDT SAT APR 23 2016
WEAK HIGH PRES SHOULD BE OVER THE AREA MON NGT...WITH CONTINUED
DRY WEATHER. BUT...A CLOSED LOW WILL BE ORGANIZING TO OUR W/SW
MOST LIKELY OVER UT OR NRN AZ. THAT SHOULD MOVE OUT TO WRN KS BY
12Z WED...THEN PROBABLY INTO IA BY 12Z THU. YET ANOTHER CLOSED LOW
IS EXPECTED TO BE OVER SRN CA BY THU MORNING. MODEL AGREEMENT IS
NOT OVERLY GREAT BY FRI...BUT THE GENERAL CONSENSUS IS THAT THE
LOW WILL PROBABLY OPEN UP AND MOVE OUT INTO THE HIGH PLAINS BY THE
WEEKEND.
THE 00Z GFS WAS SLOWER BRINGING A CHANCE OF SHRA/TSTMS BACK TO THE
AREA ON TUE COMPARED TO THE ECMWF. GAVE BOTH MODELS EQUAL WEIGHT
FOR NOW. PCPN SHOULD BE FAIRLY WIDESPREAD TUE NGT/WED...WHICH MAY
HELP LIMIT STRONG STORM COVERAGE. CURRENT EXPECTED TIMING DRIES
THE AREA OUT FOR THE PD FROM THU INTO FRI MORNING...THEN PCPN IS
LIKELY TO RETURN.
&&
.AVIATION...(12Z TAFS FOR KOMA...KLNK...KOFK THROUGH 12Z SUNDAY)
ISSUED AT 619 AM CDT SAT APR 23 2016
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD WITH CHANGE
GROUPS DUE TO INCREASE IN SFC WINDS THROUGH THE DAY AND A GRADUAL
DECREASE THIS EVENING. WILL CONTINUE TO MONITOR AREAS OF FOG EAST
OF KOMA THIS MORNING AND SEND OUT UPDATES IF IT BEGINS TO MOVE
TOWARD THE MISSOURI RIVER VALLEY.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...MILLER
LONG TERM...MILLER
AVIATION...KERN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
756 AM EDT SAT APR 23 2016
.SYNOPSIS...
A COLD FRONT WILL CONTINUE TO PUSH THROUGH THE REGION EARLY THIS
MORNING...EXITING SOUTHEAST PA BY DAWN. HIGH PRESSURE WILL BUILD
INTO THE REGION THIS WEEKEND. ANOTHER COLD FRONT IS LIKELY TO PUSH
ACROSS THE AREA TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MAIN FEATURE IN WATER VAPOR IMAGERY THIS MORNING IS UPPER LOW
TRACKING ACROSS WEST VIRGINIA. UPPER LVL DIFFLUENCE IN ADVANCE OF
THIS FEATURE IS SUPPORTING LINGERING SHOWERS ACROSS SOUTHEAST PA
AS OF 1030Z. AS UPPER LOW TRACKS EAST...EXPECT THE SHOWERS TO
PUSH SE OF THE REGION LATER THIS MORNING. LATEST HRRR AND NCAR
ENSEMBLE SUGGEST THE SHOWERS COULD LAST UNTIL ARND 14Z OVER
LANCASTER CO.
IR IMAGERY AT 10Z SHOWS AN EXTENSIVE STRATUS SHIELD EXTENDING ALL
THE WAY BACK TO LKS ERIE AND ONTARIO. HOWEVER...MDL SOUNDINGS
CONTINUE TO INDICATE CLEARING SKIES BY THIS AFTERNOON...DUE TO
DEEPENING BLYR AND MIXING OF MUCH DRIER AIR ALOFT. SUPERBLEND
TEMPS LOOKING FAIRLY SEASONABLE THIS AFTN...RANGING FROM THE U50S
OVR THE N MTNS...TO THE M-U60S SE COUNTIES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
HIGH PRESSURE WILL BECOME CENTERED OVER THE REGION LATE TONIGHT
WITH CLEAR SKIES...LOW PWATS AND NEARLY CALM AIR. INCLUDED PATCHY
FROST ACROSS THE MTNS NEAR THE I-80 CORRIDOR AND WIDESPREAD SUB-
FREEZING TEMPS ACROSS THE NRN MTNS. HOWEVER...THIS AREA OF THE
STATE IS STILL OUTSIDE OF THE BEGINNING OF THE GROWING SEASON. A
LOW PROB FOR A FROST ADVISORY IS IN THE EAST/WEST SLIVER OF
COUNTIES JUST ALONG AND JUST SOUTH OF I-80 WHERE THE OFFICIAL
START TO THE GROWING SEASON WAS THURSDAY/APRIL 21ST.
AFTER THE CHILLY START...ABUNDANT SUNSHINE SHOULD PUSH TEMPS WELL
INTO THE 60S BY SUNDAY AFTN. HIGH PRES DIRECTLY OVERHEAD SHOULD
ENSURE VERY LGT WINDS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
A SURGE OF WARMER AIR SHOULD WORK INTO PA MONDAY...AS HIGH DRIFTS
OFF THE COAST AND WARM FRONT LIFTS NORTHWARD THRU THE E GRT LKS.
MSUNNY SKIES AND MDL 8H TEMPS NR 12C SHOULD SUPPORT MAX TEMPS
FROM THE M70S N MTNS...TO THE L80S IN THE SOUTHERN VALLEYS.
ALL MED RANGE GUIDANCE INDICATES A WEAKENING SHORTWAVE TRACKING
THRU THE E GRK LKS WILL PUSH A COLD FRONT AND ASSOC BAND OF
SHOWERS SOUTHWARD ACROSS PA BY TUESDAY. SOME MDL DISAGREEMENT WITH
REGARDS TIMING OF FROPA...WITH SLOWER ECENS/SREF/CANADIAN
SOLUTIONS CURRENTLY FAVORED OVR THE FASTER GEFS. THIS SLOWER
SOLUTION RESULTS IN A GOOD CHC OF SHOWERS LASTING THRU TUESDAY...RATHER
THAN JUST MON NIGHT. CURRENT MDL-BLENDED QPF INDICATES THIS WILL
BE A RELATIVELY LIGHT RAINFALL FOR MOST OF THE AREA WITH AMTS
GENERALLY LESS THAN A HALF INCH.
LATEST ECENS AND NAEFS POINT TOWARD A DRY/SEASONABLE WEDNESDAY...AS
SFC RIDGE BUILDS ACROSS PA. NEXT CHC OF SHOWERY WX ARRIVES
THURSDAY WHEN ECENS/NAEFS BOTH TRACK A SFC LOW JUST SOUTH OF THE
STATE. FAIR WX LIKELY TO RETURN BY FRIDAY...AS LOW DEPARTS THE NE
COAST AND DRIER NW FLOW FOLLOWS ACROSS PA.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
A COLD FRONT WILL EXITING TO THE SOUTHEAST EARLY TODAY. HIGH
PRESSURE WILL BUILD INTO THE REGION THIS WEEKEND.
UPPER LOW TRACKING ACROSS WEST VIRGINIA WILL KEEP SHOWERS IN THE
LOWER SUSQ FOR NEXT COUPLE OF HOURS. OTHERWISE...AN EXTENSIVE
STRATUS SHIELD IS IN PLACE...PRODUCING WIDESPREAD RESTRICTIONS OF
MVFR IN MOST LOCALES TO IFR IN THE WESTERN AND NORTHERN HIGHER
TERRAIN. AS MIXING KICKS IN...IT WILL TAP INTO MUCH DRIER AIR
ALOFT WHICH WILL BRING IMPROVEMENT TO VFR THROUGH 18Z. A NORTH
WIND WILL PICK UP WITH SFC SPEEDS OF 10-20 MPH...BEFORE TAPERING
OFF THIS EVE.
OUTLOOK...
SUN...NO SIG WX EXPECTED.
MON-TUE...PM SHRA DEVELOPING MONDAY AND CONTINUING INTO TUESDAY.
REDUCTIONS POSSIBLE...MAINLY NW PA.
WED...NO SIG WX EXPECTED.
&&
.FIRE WEATHER...
WINDS WILL BECOME A BIT GUSTY THIS AFTN WITH RELATIVE HUMIDITY
FALLING TO NEAR 30 PERCENT BY LATE AFTN. LATEST BUFKIT SOUNDINGS
SUPPORT GUSTS BTWN 15-20KTS LATER TODAY ACROSS EASTERN PA...WITH
CONDS CLOSE TO RED FLAG CRITERIA POSSIBLE FOR A COUPLE OF HOURS
DURING LATE AFTN OR EARLY EVENING. GIVEN THE MARGINAL CONDS AND
THE LGT RAIN THAT FELL OVERNIGHT...HAVE OPTED NOT TO ISSUE EITHER
A FIRE WX WATCH OR RED FLAG WARNING. DAY SHIFT WILL LIKELY NEED TO
CONTACT PA FORESTRY FOR LATEST ASSESSMENT OF FUEL MOISTURE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD
AVIATION...RXR
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
633 AM EDT SAT APR 23 2016
.SYNOPSIS...
A COLD FRONT WILL CONTINUE TO PUSH THROUGH THE REGION EARLY THIS
MORNING...EXITING SOUTHEAST PA BY DAWN. HIGH PRESSURE WILL BUILD
INTO THE REGION THIS WEEKEND. ANOTHER COLD FRONT IS LIKELY TO PUSH
ACROSS THE AREA TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MAIN FEATURE IN WATER VAPOR IMAGERY THIS MORNING IS UPPER LOW
TRACKING ACROSS WEST VIRGINIA. UPPER LVL DIFFLUENCE IN ADVANCE OF
THIS FEATURE IS SUPPORTING LINGERING SHOWERS ACROSS SOUTHEAST PA
AS OF 1030Z. AS UPPER LOW TRACKS EAST...EXPECT THE SHOWERS TO
PUSH SE OF THE REGION LATER THIS MORNING. LATEST HRRR AND NCAR
ENSEMBLE SUGGEST THE SHOWERS COULD LAST UNTIL ARND 14Z OVER
LANCASTER CO.
IR IMAGERY AT 10Z SHOWS AN EXTENSIVE STRATUS SHIELD EXTENDING ALL
THE WAY BACK TO LKS ERIE AND ONTARIO. HOWEVER...MDL SOUNDINGS
CONTINUE TO INDICATE CLEARING SKIES BY THIS AFTERNOON...DUE TO
DEEPENING BLYR AND MIXING OF MUCH DRIER AIR ALOFT. SUPERBLEND
TEMPS LOOKING FAIRLY SEASONABLE THIS AFTN...RANGING FROM THE U50S
OVR THE N MTNS...TO THE M-U60S SE COUNTIES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
HIGH PRESSURE WILL BECOME CENTERED OVER THE REGION LATE TONIGHT
WITH CLEAR SKIES...LOW PWATS AND NEARLY CALM AIR. INCLUDED PATCHY
FROST ACROSS THE MTNS NEAR THE I-80 CORRIDOR AND WIDESPREAD SUB-
FREEZING TEMPS ACROSS THE NRN MTNS. HOWEVER...THIS AREA OF THE
STATE IS STILL OUTSIDE OF THE BEGINNING OF THE GROWING SEASON. A
LOW PROB FOR A FROST ADVISORY IS IN THE EAST/WEST SLIVER OF
COUNTIES JUST ALONG AND JUST SOUTH OF I-80 WHERE THE OFFICIAL
START TO THE GROWING SEASON WAS THURSDAY/APRIL 21ST.
AFTER THE CHILLY START...ABUNDANT SUNSHINE SHOULD PUSH TEMPS WELL
INTO THE 60S BY SUNDAY AFTN. HIGH PRES DIRECTLY OVERHEAD SHOULD
ENSURE VERY LGT WINDS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
A SURGE OF WARMER AIR SHOULD WORK INTO PA MONDAY...AS HIGH DRIFTS
OFF THE COAST AND WARM FRONT LIFTS NORTHWARD THRU THE E GRT LKS.
MSUNNY SKIES AND MDL 8H TEMPS NR 12C SHOULD SUPPORT MAX TEMPS
FROM THE M70S N MTNS...TO THE L80S IN THE SOUTHERN VALLEYS.
ALL MED RANGE GUIDANCE INDICATES A WEAKENING SHORTWAVE TRACKING
THRU THE E GRK LKS WILL PUSH A COLD FRONT AND ASSOC BAND OF
SHOWERS SOUTHWARD ACROSS PA BY TUESDAY. SOME MDL DISAGREEMENT WITH
REGARDS TIMING OF FROPA...WITH SLOWER ECENS/SREF/CANADIAN
SOLUTIONS CURRENTLY FAVORED OVR THE FASTER GEFS. THIS SLOWER
SOLUTION RESULTS IN A GOOD CHC OF SHOWERS LASTING THRU TUESDAY...RATHER
THAN JUST MON NIGHT. CURRENT MDL-BLENDED QPF INDICATES THIS WILL
BE A RELATIVELY LIGHT RAINFALL FOR MOST OF THE AREA WITH AMTS
GENERALLY LESS THAN A HALF INCH.
LATEST ECENS AND NAEFS POINT TOWARD A DRY/SEASONABLE WEDNESDAY...AS
SFC RIDGE BUILDS ACROSS PA. NEXT CHC OF SHOWERY WX ARRIVES
THURSDAY WHEN ECENS/NAEFS BOTH TRACK A SFC LOW JUST SOUTH OF THE
STATE. FAIR WX LIKELY TO RETURN BY FRIDAY...AS LOW DEPARTS THE NE
COAST AND DRIER NW FLOW FOLLOWS ACROSS PA.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
SHOWERS WILL CONTINUE TO IMPACT PORTIONS OF SOUTHERN PA THROUGH
DAWN IN VICINITY OF SLOW MOVING COLD FRONT.
TO THE NORTH OF THE FRONT...EXTENSIVE STRATUS SHIELD NOTED ACROSS
NORTHERN PA INTO UPSTATE NY...AND CIGS OVER NORTHERN AND WESTERN
SECTIONS OF CWA WILL GRADUALLY FALL TO MVFR AND IFR AS NORTHERLY
FLOW BEGINS TO INCREASE. GENERALLY VFR OVER THE SE...THOUGH A
BRIEF PERIOD OF MVFR POSS AROUND DAWN.
RESTRICTIONS WILL BE IN PLACE OVER NW HALF TO START THE DAY
SAT AS UPPER TROUGH AXIS PASSES THROUGH...BUT CONDITIONS WILL
IMPROVE TO VFR LATE MORNING AS HIGH PRESSURE BUILDS IN FROM THE
NW. A NORTH WIND WILL PICK UP WITH SFC SPEEDS OF 10-20
MPH...BEFORE TAPERING OFF SAT EVE.
OUTLOOK...
SAT...AM LOW CIGS W MTNS.
SUN...NO SIG WX EXPECTED.
MON-TUE...PM SHRA DEVELOPING MONDAY AND CONTINUING INTO TUESDAY.
REDUCTIONS POSSIBLE...MAINLY NW PA.
WED...NO SIG WX EXPECTED.
&&
.FIRE WEATHER...
WINDS WILL BECOME A BIT GUSTY THIS AFTN WITH RELATIVE HUMIDITY
FALLING TO NEAR 30 PERCENT BY LATE AFTN. LATEST BUFKIT SOUNDINGS
SUPPORT GUSTS BTWN 15-20KTS LATER TODAY ACROSS EASTERN PA...WITH
CONDS CLOSE TO RED FLAG CRITERIA POSSIBLE FOR A COUPLE OF HOURS
DURING LATE AFTN OR EARLY EVENING. GIVEN THE MARGINAL CONDS AND
THE LGT RAIN THAT FELL OVERNIGHT...HAVE OPTED NOT TO ISSUE EITHER
A FIRE WX WATCH OR RED FLAG WARNING. DAY SHIFT WILL LIKELY NEED TO
CONTACT PA FORESTRY FOR LATEST ASSESSMENT OF FUEL MOISTURE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD
AVIATION...RXR
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS EL PASO TX/SANTA TERESA NM
422 AM MDT SAT APR 23 2016
.SYNOPSIS...
WE WILL SEE A SLIGHT CHANCE FOR RAIN TODAY EAST OF THE RIO
GRANDE...OTHERWISE IT WILL BE MOSTLY SUNNY AND WARM. FOR SUNDAY
THROUGH THURSDAY WE WILL SEE BREEZY TO WINDY AFTERNOON CONDITIONS
WITH HIGH TEMPERATURES RUNNING A FEW DEGREES ABOVE NORMAL UNDER
MOSTLY SUNNY SKIES. FOR FRIDAY AND SATURDAY WE WILL SEE A SLIGHT
CHANCE FOR RAIN IN AREA MOUNTAINS.
&&
.DISCUSSION...
WE DID SEE SOME ISOLATED HEAVY RAIN YESTERDAY WITH A FEW SPOTS
EVEN GETTING SOME SMALL HAIL. MOST OF US THOUGH SAW LOTS OF CLOUDS
BUT LITTLE OR NO RAIN. THE MOISTURE IS QUICKLY MOVING TO THE EAST
OF THE AREA THIS MORNING...BUT THERE WILL BE ENOUGH MOISTURE
LINGERING TO GIVE US A SLIGHT CHANCE FOR AFTERNOON THUNDERSTORMS
EAST OF THE RIO GRANDE. THESE STORMS (IF THERE ARE ANY) WILL BE
VERY SPOTTY IN NATURE. IF A STORM DOES POP UP IT WILL BE CAPABLE
OF PRODUCING SOME STRONG OUTFLOW WINDS. THE VAST MAJORITY OF US
WILL STAY WARM AND DRY TODAY AS A ZONAL FLOW WILL HELP GIVE US
BREEZY AFTERNOON WINDS. SPEAKING OF WINDS THAT WILL BE THE STORY
FOR MUCH OF THE NEXT WEEK. WE WILL SEE BREEZY TO WINDY CONDITIONS
TODAY THROUGH AT LEAST TUESDAY. TUESDAY`S WINDS MAY APPROACH
ADVISORY LEVEL (25 TO 35 MPH) AS AN UPPER LEVEL TROUGH PASSES TO
OUR NORTH. WE WILL LIKELY SEE MORE BREEZY AFTERNOON WINDS TO
FINISH OUT THE WEEK (IT IS STILL THE WINDY SEASON AFTER ALL).
TEMPERATURES FOR MUCH OF THE COMING WEEK WILL BE NEAR OR A FEW
DEGREES ABOVE NORMAL. BY THE END OF NEXT WEEK ANOTHER APPROACHING
UPPER LEVEL STORM SYSTEM WILL BRING A SLIGHT CHANCE FOR RAIN TO
THE GILA REGION.
&&
.AVIATION...VALID 23/12Z-24/12Z
WE WILL SEE VFR CONDITIONS FOR THE NEXT 24 HOURS (AND SEVERAL DAYS
BEYOND THAT). THERE WILL BE JUST ENOUGH MOISTURE TO HELP FUEL A
FEW ISOLATED THUNDERSTORMS EAST OF THE RIO GRANDE THIS AFTERNOON.
IF STORMS DO DEVELOP THEY WILL BE CAPABLE OF PRODUCING SOME STRONG
GUSTY SURFACE WINDS. WE WILL SEE CLOUDS OF MAINLY FEW-SCT080 THIS
AFTERNOON...BUT A FEW SPOTS COULD SEE A CEILING OF BKN080. SURFACE
WINDS WILL BE FROM THE WEST AND GUSTY THIS AFTERNOON 24015G25KT.
&&
.FIRE WEATHER...
WE WILL SEE AN ACTIVE WEEK FOR FIRE WEATHER WITH THE WINDS BEING
THE NEWS MAKER. FOR TODAY AND SUNDAY WE WILL SEE NEAR READ FLAG
CONDITIONS AS WE WILL HAVE GUSTY AFTERNOON WINDS WITH MIN RH`S IN
THE TEENS TODAY AND IN THE UPPER SINGLE DIGITS ON SUNDAY IN THE
LOWLANDS. FOR MONDAY AND TUESDAY WE WILL STILL SEE VERY DRY
CONDITIONS AND THE WINDS WILL BE A LITTLE STRONGER SO IT DOES
APPEAR THAT WE WILL SEE RED FLAG CONDITIONS BOTH AFTERNOONS. FOR
WEDNESDAY THROUGH FRIDAY WE WILL CONTINUE TO SEE PRETTY DRY
CONDITIONS WITH MIN RH`S IN THE TEENS...BUT WINDS WHILE
BREEZY...SHOULD STAY BELOW CRITICAL LEVELS.
&&
.PRELIMINARY POINT TEMPS/POPS...
EL PASO 85 62 85 61 / 10 0 0 0
SIERRA BLANCA 81 57 82 57 / 20 0 0 0
LAS CRUCES 83 54 81 53 / 0 0 0 0
ALAMOGORDO 83 55 81 52 / 10 0 0 0
CLOUDCROFT 59 41 60 40 / 20 0 0 0
TRUTH OR CONSEQUENCES 82 53 81 52 / 0 0 0 0
SILVER CITY 76 46 73 45 / 0 0 0 0
DEMING 84 54 82 52 / 0 0 0 0
LORDSBURG 85 50 81 48 / 0 0 0 0
WEST EL PASO METRO 84 61 84 61 / 0 0 0 0
DELL CITY 83 53 85 53 / 20 0 0 0
FORT HANCOCK 83 58 86 58 / 10 0 0 0
LOMA LINDA 78 57 80 56 / 10 0 0 0
FABENS 84 58 85 58 / 10 0 0 0
SANTA TERESA 84 58 84 57 / 0 0 0 0
WHITE SANDS HQ 83 59 81 56 / 0 0 0 0
JORNADA RANGE 83 51 82 50 / 0 0 0 0
HATCH 85 52 84 50 / 0 0 0 0
COLUMBUS 86 55 83 54 / 0 0 0 0
OROGRANDE 83 59 83 56 / 10 0 0 0
MAYHILL 69 47 71 47 / 20 0 0 0
MESCALERO 70 44 70 45 / 20 0 0 0
TIMBERON 68 46 69 45 / 20 0 0 0
WINSTON 74 43 73 42 / 0 0 0 0
HILLSBORO 79 50 77 49 / 0 0 0 0
SPACEPORT 83 52 82 51 / 0 0 0 0
LAKE ROBERTS 75 39 72 39 / 0 0 0 0
HURLEY 78 47 75 46 / 0 0 0 0
CLIFF 82 42 78 41 / 0 0 0 0
MULE CREEK 80 39 75 39 / 0 0 0 0
FAYWOOD 79 49 77 47 / 0 0 0 0
ANIMAS 85 53 82 51 / 0 0 0 0
HACHITA 86 52 82 51 / 0 0 0 0
ANTELOPE WELLS 84 53 81 51 / 0 0 0 0
CLOVERDALE 80 50 77 48 / 0 0 0 0
&&
.EPZ WATCHES/WARNINGS/ADVISORIES...
NM...NONE.
TX...NONE.
&&
$$
BRICE
[top]
Area Forecast Discussion
National Weather Service Midland/Odessa TX
518 AM CDT SAT APR 23 2016
.DISCUSSION...
See 12Z Aviation Discussion below.
&&
.AVIATION...
VFR conditions will prevail next 24 hours, except in direct
convection. KMAF VAD profiler shows a 45kt LLJ continuing over
the area this AM, w/plenty of high cloud moving thru a dirty
ridge over the area. Sfc flow is forecast yo veer slightly to S
over the next 24 hours, w/a 40+kt LLJ forecast to redevelop after
sunset Saturday night. Forecast soundings develop a widespread cu
field by late morning most terminals, w/bases 4-7 kft agl. As an
upper trough moves thru the region today/tonight, could see some
convection develop over the Big Bend/Lwr Trans Pecos. This will
affect mainly KFST, although the latest HRRR and NAM suggest
convection may develop a little further north.
&&
.PREV DISCUSSION... /issued 453 AM CDT SAT APR 23 2016/
DISCUSSION...
Upper ridging is over the region with an upper low over northern
Mexico that is moving northward. This upper low will bring an
increase in moisture to the area and will allow for a chance of rain
and thunderstorms today across areas primarily south and west of the
Pecos River. Despite an increase in moisture, temperatures will
likely be a couple degrees warmer than yesterday with southerly
winds across the area.
On Sunday, the upper low will move east of the region resulting in
dryer conditions for the area. A surface trough will develop with
west to southwest winds across the area on Sunday allowing for
temperatures to warm up into the upper 80s to lower 90s for much of
the CWA. Similar conditions as Sunday are expected on Monday. An
upper trough will begin moving over the central conus on Tuesday
with the base of the trough moving over the CWA. A surface trough
will also be across the area on Tuesday. The base of the upper
trough moving over the region will result in stronger winds aloft
mixing downward to the surface. This will likely result in critical
fire weather conditions across western portions of the CWA as the
dryline remains to the east. See the fire weather discussion below.
There will be a chance of thunderstorms across the Western Low
Rolling Plains southward to the Lower Trans Pecos Tuesday evening
into Tuesday night as the dryline moves slightly west. The upper
trough will move away from the region on Wednesday with drying
conditions until the next upper trough that is expected to
approach the area next Thursday/Friday.
FIRE WEATHER...
WV imagery shows an upper-lvl trough moving thru NV, and is forecast
to eject into the upper Midwest by 00Z Monday. This will be
followed by a Pac trough making landfall in the PacNW around 06Z
Monday, and quickly digging to the Four Corners by 18Z Tuesday. This
will result in critical fire wx conditions developing as soon as
Sunday across the Guadalupe Mtns/SE NM Plains, and evolving into a
widespread Red Flag day across much of the western fire districts
Tuesday as the Pac trough ejects to the north. While current ERCs
over the Trans Pecos region are below-normal, current Fire Danger
over SE NM and adjacent West Texas is already High-to-Very High,
w/reports of plenty of cured (and tall) fuels west of KINK. As both
upper-lvl troughs translate eastward into the CONUS,
associated leeside troughing on the Front Range will veer 20` winds
to a more westerly direction over the next few days and, combined
w/expected above-normal temps, will only increase Fire Danger and
maintain low RHs. Sunday, as the first trough passes north,
forecast soundings at KGDP mix to around H65, where 25-30kt
westerlies are forecast. These winds will extend some distance
south into West Texas, mainly Culberson, Reeves, and Jeff Davis
Counties. However, throwing much of this into question will be any
convection that develops over the next 24 hours as the trough moves
east thru the region, especially south. For brevity, we`ll issue a
Fire Wx Watch for the areas mentioned above for Sunday, and let
later shifts reassess. Monday looks similar to Sunday, and roughly
the same area will likely be affected. Tuesday looks to be the big
day as the secondary trough ejects just north of West Texas and
Southeast New Mexico.
&&
.PRELIMINARY POINT TEMPS/POPS...
Big Spring 82 60 88 60 / 10 10 10 0
Carlsbad 87 56 87 57 / 10 20 0 0
Dryden 81 62 89 62 / 20 20 10 0
Fort Stockton 83 60 90 59 / 20 20 0 0
Guadalupe Pass 78 55 78 54 / 20 20 0 0
Hobbs 83 56 84 54 / 10 10 0 0
Marfa 76 47 81 47 / 20 20 0 0
Midland Intl Airport 83 62 89 59 / 10 10 0 0
Odessa 83 62 89 60 / 10 10 0 0
Wink 86 61 92 58 / 10 10 0 0
&&
.MAF Watches/Warnings/Advisories...
NM...Fire Weather Watch from Sunday morning through Sunday evening
for Guadalupe Mountains-Southeast Plains.
TX...Fire Weather Watch from Sunday morning through Sunday evening
for Davis/Apache Mountains Area-Guadalupe Mountains-Reeves
County and Upper Trans Pecos-Van Horn and Highway 54
Corridor.
&&
$$
44/80/44
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
323 PM MDT SAT APR 23 2016
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 233 PM MDT SAT APR 23 2016
THE UPPER TROUGH OVER NORTHERN UTAH/SOUTHWESTERN WYOMING THIS
AFTERNOON WILL TRACK TO THE NORTHEAST INTO CENTRAL WYOMING
OVERNIGHT...THEN INTO SOUTH DAKOTA BY LATE AFTN. BEST QG ASCENT
ASSOCIATED WITH THIS PASSING TROUGH WILL AROUND 00Z THEN STRONGER
QG DESCENT BUILDS IN FROM THE WEST. THE LATEST HRRR DEVELOPS A
LITTLE BETTER SHOWER/TSTMS COVERAGE BUT IT LOOKS OVERDONE COMPARED
TO PRVS RUNS. BEST CHC FOR MOUNTAIN SNOW WILL BE IN ZONES 31 AND
33...WITH BEST SHOWER/TSTM POTENTIAL ALONG THE NORTHEAST BORDER
OF THE NORTHEAST PLAINS. SHOWERS/TSTMS LATE THIS AFTN AND EVENING
COULD PACK SOME FAIRLY STRONG GUSTS...UP TO 50 MPH ACROSS THE
NORTHEAST PLAINS. STRONG JETSTREAM WINDS ALOFT OVER THE CWA THIS
AFTN SO EVEN STRONGER GUSTS IN THE MOUNTAINS/HIGHER FOOTHILLS TO
70 MPH. STRONG SUBSIDENCE LATER THIS EVENING WILL PRODUCE
AN AMPLIFIED MOUNTAIN WAVE SO STRONGER GUSTS WILL PERSIST ACROSS
THOSE AREAS OVERNIGHT. STRONGER WINDS ACROSS THE NORTHEAST PLAINS
SHOULD SUBSIDE AFT 03Z WITH THE DISSIPATION OF ANY SHOWERS. ON
SUNDAY...MDLS STILL SHOW OROGRAPHIC SNOW SHOWERS THROUGH
THE MORNING...PRIMARILY NORTH OF INTERSTATE 70...THEN THE SNOW
SHOWERS DRY UP. ACROSS THE NORTHEAST PLAINS...DRY WITH THE
EXCEPTION OF MAYBE AN EARLY MORNING SHOWER ALONG THE NORTHERN
BORDER. GUSTY WINDS THE MAIN ISSUED THROUGH THE DAY ON
SUNDAY....ESPECIALLY ALONG THE NORTHERN BORDER. NO HIGHLIGHTS BUT
WINDY THROUGH THE DAY.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 233 PM MDT SAT APR 23 2016
SEVERAL SHORT WAVE TROUGHS MOVING OFF THE PACIFIC AND INTO THE
SOUTHWESTERN U.S. WILL KEEP AN ACTIVE WEATHER PATTERN IN PLACE.
ON MONDAY...ONE SHORT WAVE WILL MOVE INTO THE SOUTHWEST U.S. AND
ATTEMPT TO CLOSE OFF IN THE GREAT BASIN TO NEAR LAS VEGAS. AHEAD
OF THIS...DEEP LAYER Q-G LIFT WILL OCCUR ACROSS COLORADO...
RESULTING IN INCREASING SHOWER AND AFTERNOON STORM COVERAGE. MOST
OF THIS WILL INITIALLY OCCUR IN THE MOUNTAINS...BUT THEN SPREAD
OFF THE TERRAIN AND/OR DEVELOP ON THE PLAINS AS THE AIRMASS
DESTABILIZES LATE IN THE AFTERNOON THROUGH MONDAY NIGHT.
BY TUESDAY...MODELS ARE STILL WOBBLING WITH THE EVENTUAL LOCATION
OF THE UPPER LOW AS IT MOVES EAST TOWARD THE PLAINS. THE LATEST
ECMWF WAS MUCH MORE CONSOLIDATED AND MOVES THE UPPER LOW RIGHT
OVER THE FORECAST AREA. THE CANADIAN WAS ALSO MORE TIGHTLY WOUND
BUT FARTHER NORTH...WHILE MOST OTHER MODELS INCLUDING THE GFS AND
ITS ENSEMBLES...AND THE 00Z ECMWF WERE MORE OPEN WITH THE TROUGH.
DESPITE THE UNCERTAINTY WITH THE EXACT TRACK...THE MAIN PICTURE
THROUGH THIS TIME WILL BE UNSETTLED WEATHER WITH A GOOD CHANCE OF
SHOWERS AND THUNDERSTORMS. THERE WILL BE SNOW IN THE MOUNTAINS AND
HIGHER FOOTHILLS...AND SOME THREAT OF SNOW SPREADING DOWN ONTO
HIGHER ELEVATIONS OF THE PLAINS TUESDAY NIGHT WITH COLDER AIR
ARRIVING ALOFT. IN FACT...THE 12Z ECMWF SHOWED SNOW AS EARLY AS
TUESDAY AFTERNOON ALONG THE FRONT RANGE GIVEN ITS DEEPER AND
COLDER SOLUTION. MEANWHILE IF THE STORM IS SLOWER THAN THE THREAT
OF STRONGER STORMS WILL EXIST OVER THE EASTERN PLAINS.
THAT SYSTEM EVENTUALLY KICKS OUT TO THE NORTHEAST WEDNESDAY SO
MAINLY DRIER BUT COOL WEATHER EXPECTED. STILL CANT RULE OUT A FEW
LINGERING SHOWERS BUT SHOULD BE ISOLATED.
THE NEXT STORM SYSTEM MAY BEGIN TO IMPACT THE FORECAST AREA BY
LATE THURSDAY AS IT TOO DIVES INTO THE SOUTHWEST U.S. SIMILAR TO
MONDAY/TUESDAY SYSTEM. THIS STORM SYSTEM WILL LIKELY BRING MORE
SHOWERS AND THUNDERSTORMS...AND MOUNTAIN SNOWFALL...TO THE REGION
LATE THURSDAY THROUGH FRIDAY NIGHT. A FEW SHOWERS COULD LINGER
INTO SATURDAY. DAYTIME HIGHS WILL AVERAGE SEVERAL DEGREES BELOW
NORMAL DURING THIS MOIST AND UNSETTLED PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 233 PM MDT SAT APR 23 2016
AVIATION...VFR CONDITIONS EXPECTED. SOUTHWEST TO WEST WINDS
THRU 01Z 20-30 KTS THEN SOUTHWEST/SOUTH WINDS WITH THE STRONGER
GUSTS SUBSIDING AT KDEN/KAPA 04-05Z. DO NOT ANTICPATE TSTMS AT
THIS TIME BUT WL KEEP VCSH THROUGH 05Z. HIGH BASED SHOWERS COULD
PRODUCE GUSTS 40-45KT. AT KBJC...GUSTY WEST-SOUTHWEST WINDS WILL
CONTINUE OVERNIGHT...SO MAY SEE GUST TO 40-45KT OVERNIGHT WITH THE
DEVELOPMENT OF DOWNSLOPE WINDS. ON SUNDAY...GUSTY WEST-NORTHWEST
WINDS AT ALL THE AIRPORT EXPECTED AFTER 18Z.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...COOPER
LONG TERM...BARJENBRUCH
AVIATION...COOPER
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1016 AM MDT SAT APR 23 2016
.UPDATE...
ISSUED AT 1013 AM MDT SAT APR 23 2016
STRONG WINDS ALREADY DEVELOPING ABOVE TIMBERLINE THIS MORNING SO
HAVE UPDATED TO GRIDS TO ACCOUNT FOR STRONGER GUSTS IN THE
MOUNTAINS TODAY. MOSTLY CLOUDY ACROSS MUCH OF THE URBAN CORRIDOR
AND NORTHEAST PLAINS TODAY TOO. AS A RESULT...I SHAVED A DEGREE
OR TWO OF THE MAX TEMPERATURES BUT STILL QUITE MILD.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 412 AM MDT SAT APR 23 2016
SOUTHWEST WINDS ALOFT WILL BE INCREASING TODAY AHEAD OF AN
APPROACHING UPPER TROUGH THAT IS OVER WESTERN UTAH THIS MORNING.
AS DAYTIME WARMING INCREASES THE DEPTH OF THE BOUNDARY LAYER...THE
WINDS ALOFT ARE EXPECTED TO MIX DOWN TO THE SURFACE...BRINGING
GUSTY WINDS TO THE PLAINS THROUGH THE AFTERNOON. THE LATEST RUNS
OF THE HRRR MODEL HAVE BEEN SHOWING A CONSOLIDATED BAND OF SHOWERS
ASSOCIATED WITH THE TROUGH AXIS MOVING OVER THE MOUNTAINS AFTER
22Z. LIGHTNING HAS BEEN DETECTED THIS MORNING OVER
UTAH...INDICATING THE INSTABILITY OF THE AIRMASS THAT WILL
ACCOMPANY THE UPPER TROUGH AS IT MOVES ACROSS THE STATE. MODEL
SOUNDINGS SHOW THAT FREEZING LEVELS WILL BE AROUND 12000 FEET MSL
AHEAD OF THE TROUGH...SO THE MOUNTAINS WILL SEE A MIX OF RAIN AND
SNOW WITH THE AFTERNOON SHOWERS...WITH THE SNOW LEVELS DROPPING
LATER IN THE EVENING. MODEL SOUNDINGS ALSO SHOW THE AIRMASS WILL
BE QUITE DRY ON THE PLAINS...MAKING IT TOUGH FOR ANY RAIN TO
REACH THE GROUND ON THE PLAINS. HOWEVER...GUSTY WINDS ARE EXPECTED
THROUGH THE LATE AFTERNOON AND EVENING DUE TO DOWNBURSTS FROM
VIRGA SHOWERS AND THE SOUTHWEST FLOW AT MID-LEVELS BEING MIXED
DOWN TO THE SURFACE. AS THE UPPER TROUGH MOVES EASTWARD AND ONTO
THE PLAINS...SHOWER ACTIVITY OVER THE MOUNTAINS AND PLAINS WILL BE
DECREASING BY MIDNIGHT. TEMPERATURES WILL ALSO COOL DOWN LATER
TONIGHT AS THE POST-TROUGH AIRMASS MOVES IN.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 412 AM MDT SAT APR 23 2016
AN UPPER LEVEL STORM SYSTEM WILL BE CENTERED OVER ERN WY EARLY ON
SUN AND THEN WILL MOVE SLOWLY EAST INTO SCNTRL SOUTH DAKOTA AND
NCNTRL NEBRASKA BY EARLY SUN EVENING. COMBINATION OF RATHER STG SFC
GRADIENT AND QG DOWNWARD DESCENT WILL ALLOW FOR STG WINDS IN THE
MORNING ESPECIALLY ACROSS THE NRN FOOTHILLS AND HIGHER MTNS. WOULD
NOT BE SURPRISED TO SEE A SOME SPOTS RECEIVE HIGH WIND CRITERIA
FOR A FEW HOURS. MEANWHILE GUSTY WINDS WILL ALSO OCCUR OVER THE
PLAINS BUT SPEEDS SHOULD STAY BLO HIGH WIND CRITERIA.
AS FAR AS PCPN CROSS-SECTIONS CONTINUE TO SHOW FAVORABLE OROGRAPHICS
AND LINGERING MOISTURE IN THE NRN MTNS MAINLY NR THE WY BORDER WITH
ADVISORY AMOUNTS POSSIBLE IN ZN 31. OTHERWISE MAY SEE A FEW AFTN
SHOWERS ACROSS THE PLAINS NEAR THE WY-NE BORDER. AS FOR HIGHS
READINGS WILL DROP BACK INTO THE 65 TO 70 DEGREE RANGE ACROSS NERN
CO.
BY MON THE FLOW ALOFT WILL BECOME SWLY AS ANOTHER STORM SYSTEM
MOVES INTO THE GREAT BASIN. MEANWHILE SFC LOW PRES WILL INTENSIFY
ALONG THE FOOTHILLS WITH GUSTY SSE WINDS ACROSS THE PLAINS BY
AFTN. AS FOR PCPN POTENTIAL...MOISTURE WILL INCREASE BY AFTN IN
THE MTNS AND COMBINE WITH FAVORABLE LAPSE RATES FOR SOME SCT
SHOWERS AND POSSIBLE A FEW TSTMS. OVER NERN CO IT WILL BE DRY
ALTHOUGH THERE COULD BEA FEW LATE AFTN HIGH BASED STORMS ALONG THE
FRONT RANGE. AS FOR HIGHS READINGS WILL BE IN THE MID 60S TO LOWER
70S ACROSS THE PLAINS.
FOR MON NIGHT THRU TUE ONCE AGAIN ITS NOT CLEAR HOW THE UPPER LEVEL
STORM SYSTEM WILL EVOLVE. IT APPEARS ONCE PIECE OF ENERGY MAY
MOVE NNE INTO THE NRN ROCKIES WHILE SIGNIFICANT ENERGY REFORMS
INTO A CLOSED LOW NEAR THE FOUR CORNERS AREA BY TUE. MEANWHILE
THE MAIN SFC LOW MAY INTENSIFY OVER SERN CO WITH DEEPER LOW LVL
MOISTURE ADVECTING INTO NERN CO NORTH OF A WRM FNT. OVERALL SHOULD
SEE A CHC OF SHOWERS AND TSTMS ESPECIALLY ACROSS THE PLAINS MON
NIGHT. ON TUE BEST CHC OF SHOWERS AND TSTMS WILL BE IN THE AFTN
ACROSS THE AREA. THERE ALSO COULD BE SOME THREAT OF STRONGER
STORMS ACROSS PORTIONS OF THE PLAINS TUE AFTN NEAR THE TRIPLE
POINT AND JUST NORTH OF THE WRM FRONT.
BY TUE NIGHT INTO WED THERE IS SOME POTENTIAL THAT THE UPPER LEVEL
LOW NEAR THE FOUR CORNERS WILL INTENSIFY AND MOVE INTO SERN CO BY
12Z WED AND THEN LIFT NORTHEAST INTO NWRN KANSAS/SWRN NEBRASKA BY
WED AFTN. IF THIS OCCURS THEN THERE COULD BE SOME SIGNIFICANT PCPN
TUE NIGHT INTO WED ACROSS PORTIONS OF NRN CO. BUFFER SOUNDINGS SHOW
TEMPS WILL BE WRM ENOUGH FOR PCPN TO FALL MOSTLY AS RAIN ACROSS THE
PLAINS WITH THE SNOW LEVEL ABOVE 6000 FT.
FOR WED NIGHT INTO THU THE UPPER LEVEL LOW IS FCST TO MOVE ENE OF
THE AREA AS ANOTHER SYSTEM DIVES INTO SRN CALIFORNIA. THUS SHOULD
SEE DRIER CONDITIONS WED NIGHT INTO THU. HOWEVER LINGERING MOISTURE
COMBINED WITH AFTN HEATING MAY LEAD TO A SLIGHT CHC OF SHOWERS AND
TSTMS ACROSS THE HIGHER TERRAIN AND ALONG THE FRONT RANGE.
BY FRI THE ECMWF AND GFS WANT TO EJECT THE LOW FM SRN CALIFORNIA
INTO THE FOUR CORNERS AREA BY FRI AFTN WHILE THE CANADIAN MODEL IS
CONSIDERABLY SLOWER AND FUTHER SW. THIS FAR OUT HARD TO SAY WHAT
WILL HAPPEN WITH THIS NEXT FEATURE. FOR NOW WILL JUST GO WITH CHC
POPS IN THE MTNS WITH A SLIGHT CHC OVER THE PLAINS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1013 AM MDT SAT APR 23 2016
VFR CONDITIONS EXPECTED. SOUTH TO SOUTHWEST WINDS WILL BE
INCREASING THROUGH THIS AFTERNOON AS A SURFACE TROUGH DEEPENS OVER
THE EASTERN PLAINS. GUSTS UP TO 30 MPH CAN BE EXPECTED BY LATE
THIS AFTERNOON. CONVECTION IS EXPECTED OVER THE FOOTHILLS THIS
AFTERNOON WHICH COULD MOVE OUT OVER THE URBAN CORRIDOR DURING THE
EVENING AS THE MAIN UPPER TROUGH PROGRESSES EASTWARD. GUSTY WINDS
BUT LITTLE PRECIPITATION IS EXPECTED FROM THE HIGH BASED SHOWERS.
GUSTS 40-50 MPH WILL BE POSSIBLE WITH THE EARLY EVENING SHOWER
ACTIVITY.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...COOPER
SHORT TERM...DANKERS
LONG TERM...RPK
AVIATION...COOPER
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
156 PM EDT SAT APR 23 2016
.UPDATE...
ISSUED AT 156 PM EDT SAT APR 23 2016
ADJUSTED THE SKY COVER...TEMPERATURES...AND DEW POINTS OVER THE
NEXT SEVERAL HOURS. CLEARING HAS BEEN WORKING IN FROM THE NORTH
MORE AGRESSIVELY IN THE PAST COUPLE OF HOURS. MADE A FEW TWEAKS TO
THE HIGH TEMPERATURES BASED ON THE LATEST TRENDS...BUT THE MAIN
ADJUSTMENTS WERE RETARDING THE DIURNAL CLIMB A BIT MORE OVER THE
NEXT 1 TO 2 HOURS...BEFORE A LATE DAY COMEBACK ENSUES ONCE THE
BETTER CLEARING TAKES PLACE.
UPDATE ISSUED AT 1041 AM EDT SAT APR 23 2016
THE UPPER LEVEL TROUGH AXIS CONTINUES TO SHIFT OFF TO THE
EAST...WITH HEIGHTS RECOVERING THE REST OF THE DAY. SPRINKLES/VERY
LIGHT RAIN SHOWERS HAVE EXITED OUR FAR SOUTHEAST...BUT CLOUDS
LOOK TO HANG TOUGH TODAY AND MODELS ARE A BIT OPTIMISTIC WITH THE
CLEARING COMPARED TO THE VISIBLE SATELLITE TRENDS. GIVEN THE LOW
LEVEL NORTH TO NORTHEAST FLOW AND MAINLY NEUTRAL ADVECTION AT 850
MB...HAVE ALLOWED THE CLOUDS TO HANG ON LONGER. CONSEQUENTLY...
TEMPERATURES ARE ALSO RUNNING A BIT COOLER...SO HAVE LOWERED THE
HIGHS SOMEWHAT...MAINLY LOW TO MID 60S FOR MOST EAST OF
I-75...WITH UPPER 60S TO AROUND 70 WEST OF I-75...WHERE CLEARING
WILL TAKE PLACE THE QUICKEST. UPDATES HAVE BEEN SENT.
UPDATE ISSUED AT 736 AM EDT SAT APR 23 2016
RADAR CONTINUES TO SHOW LIGHT RETURNS ACROSS THE HIGHER TERRAIN
WHERE LOW LEVELS REMAIN SATURATED BENEATH A LOW STRATUS DECK. HAVE
THEREFORE INSERTED SPRINKLES THROUGH MID MORNING AS NOTHING MORE
THAN A TRACE OF PRECIPITATION SHOULD BE POSSIBLE. REDUCED
VISIBILITIES ALSO OCCURRING IN SPOTS...BUT BLANKET OF LOW CLOUDS
SHOULD NEGATE ANY THREAT FOR WIDESPREAD DENSE FOG.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 338 AM EDT SAT APR 23 2016
UPPER TROUGH CURRENTLY PUSHING EAST ACROSS WEST VIRGINIA WILL
BRING DEEP LAYER SUBSIDENCE TO EASTERN KENTUCKY...LEADING TO
GRADUALLY CLEARING SKIES LATER THIS MORNING. BEFORE THEN...A BATCH
OF LOW STRATUS WILL CONTINUE TO PROPAGATE SOUTH ACROSS THE OHIO
VALLEY AND INTO THE COMMONWEALTH AHEAD OF A SURFACE RIDGE BUILDING
ACROSS THE GREAT LAKES AS LOW LEVELS REMAIN RATHER MOIST. THIS
SHOULD KEEP FOG PATCHY IN NATURE AS RADIATIONAL COOLING WILL BE
IMPEDED BY THE INCOMING CLOUD DECK. HOWEVER...NOT EXPECTING ANY
ADDITIONAL RAINFALL WITH UPPER SUPPORT OFF TO THE EAST AND DRYING
MID-UPPER LEVELS.
WILL SEE ALL FOG MIX OUT BY MID-LATE MORNING AS DRIER AIR
CONTINUES TO BUILD TOWARD THE SURFACE. CLOUD COVER WILL ERODE WITH
SKIES CLEARING OUT BY LATER THIS AFTERNOON INTO TONIGHT. LIGHT
NORTHERLY WINDS WILL BRING SUBTLE COOL AIR ADVECTION AND ACT TO
HOLD HIGH TEMPERATURES THIS AFTERNOON IN THE MID 60S TO LOW 70S.
SURFACE HIGH PRESSURE MIGRATING ACROSS THE EASTERN GREAT LAKES
INTO THE APPALACHIANS WILL KEEP SKIES CLEAR TONIGHT AND WINDS
LIGHT. GIVEN RECENT PRECIPITATION FRIDAY...AT LEAST PATCHY VALLEY
FOG SHOULD BE A CERTAINTY AS AN APPRECIABLE RIDGE/VALLEY SPLIT
DEVELOPS. EXPECT A FEW OF THE MORE SHELTERED VALLEY LOCALES TO
DROP INTO THE UPPER 30S WITH MOST RIDGE LOCATIONS GENERALLY IN THE
LOW-MID 40S.
BUILDING HEIGHTS ALOFT AND VEERING SOUTHERLY WINDS WILL LEAD TO A
NOTICEABLE WARMUP FOR SUNDAY AS TEMPERATURES TOP OUT IN THE UPPER
70S TO LOWER 80S.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 338 AM EDT SAT APR 23 2016
OUR WEATHER SHOULD BE MORE ACTIVE NEXT WEEK AS SHORTWAVES EJECT
OUT OF A WESTERN CONUS THROUGH AND TRACK JUST TO OUR WEST INTO THE
UPPER MIDWEST AND GREAT LAKES REGION. AT THE SURFACE...A FRONTAL
BOUNDARY WILL DROP INTO THE REGION BY TUESDAY AND HANG AROUND
THROUGH MIDWEEK. A LOW PRESSURE SYSTEM WILL ALSO GET ORGANIZED
OVER THE PLAINS MIDWEEK. THIS SYSTEM WILL TRACK EASTWARD SENDING A
COLD FRONT TOWARD OUR REGION LATE IN THE WORK WEEK.
SENSIBLE WEATHER WILL FEATURE A NICE WARM MONDAY WITH PLENTY OF
SUNSHINE AND HIGHS IN THE LOW TO MID 80S. THE THREAT FOR SHOWERS
AND THUNDERSTORMS WILL THEN INCREASE FROM NORTH TO SOUTH LATE
MONDAY NIGHT INTO TUESDAY AS THE FRONT DROPS SOUTH INTO THE
REGION. JUST SCATTERED SHOWERS/STORMS ARE ANTICIPATED TUESDAY AND
WEDNESDAY AS THE FRONT IS NOT PARTICULARLY STRONG OR EQUIPPED WITH
MUCH MOISTURE. OUR BEST CHANCE FOR SHOWERS/STORMS APPEARS TO BE
WEDNESDAY NIGHT INTO THE DAY ON THURSDAY AS THE COLD FRONT ENTERS
THE SCENE FROM THE WEST. LESSER RAIN CHANCES ARE FORECAST FOR
FRIDAY...BUT CANNOT REMOVE THEM TOTALLY WITH THE FRONT AND
ACCOMPANYING LOW PRESSURE SYSTEM REMAINING NEARBY PER THE GFS AND
ECMWF.
DESPITE THE DAILY CHANCE OF RAIN TUESDAY THROUGH FRIDAY...A
WIDESPREAD SOAKING RAINFALL APPEARS UNLIKELY AT THIS TIME.
ALSO...DESPITE THE FRONTAL PASSAGE LATE IN THE WEEK...TEMPS WILL
REMAIN WELL ABOVE NORMAL...ONLY DROPPING FROM THE LOW TO MID 80S
TUESDAY THROUGH THURSDAY TO THE MID TO UPPER 70S ON FRIDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 156 PM EDT SAT APR 23 2016
IFR/MVFR STRATOCU WILL GRADUALLY RAISE AND SCATTER OUT THROUGH
22Z...WITH SJS HANGING ON TO THE LOWER CEILINGS THE LONGEST.
CLEARING WILL REIGN TONIGHT...HOWEVER AS WINDS LIGHTEN UP AND LOW
LEVEL MOISTURE REMAINS...SOME VALLEY FOG WILL LIKELY
FORM...ESPECIALLY ALONG AND SOUTH OF THE HAL ROGERS PARKWAY AND
HIGHWAY 80 CORRIDORS. AS SUCH...DID CARRY A SMALL WINDOW OF MVFR
VISIBILITIES AT LOZ AND SME...AND IFR AT SJS. VFR CONDITIONS WILL
RETURN BETWEEN 12 AND 14Z. NORTH TO NORTHEAST WINDS OF 5 TO 10
KTS WILL BECCOME LIGHT AND VARIABLE AFTER DUSK.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEOGERIAN
SHORT TERM...GUSEMAN
LONG TERM...ABE
AVIATION...GEOGERIAN
Area Forecast Discussion
National Weather Service Paducah KY
1234 PM CDT SAT APR 23 2016
.UPDATE...
Issued at 1231 PM CDT Sat Apr 23 2016
The AVIATION section has been updated for the 18Z TAF issuance.
&&
UPDATE Issued at 939 AM CDT Sat Apr 23 2016
Updated for Today due to clouds. Pesky thin layer of low clouds
will remain through much of the morning before mostly dissipating
by early afternoon. Have adjusted today`s max temps down a degree
or two in the central and eastern parts of the FA where cloud
cover is extensive this morning.
&&
.SHORT TERM...(Today through Monday night)
Issued at 304 AM CDT Sat Apr 23 2016
The main issue early this morning is surface high pressure surging
southwest into the region. It is keeping the northeast winds
stirred up and ushering in a solid layer of IFR level clouds that
guidance does not have a good handle on. The clouds now cover much
of the Evansville Tri State, and should continue to push
southward, per the RAP low-level RH forecast, toward the Lakes and
Pennyrile. Figure that the low clouds will dissipate quickly this
morning by 15Z.
The clouds will have more of an impact on aviation concerns, and
the AVIATION of this discussion has been updated as well.
Temperatures may be held up just a bit under the cloud cover
through daybreak, but not much, and they may hold down highs a
degree or two in the east. With plenty of sunshine expected this
afternoon and dry air in place over the region, this forecast still
leaned toward the warmer side of the guidance envelope for highs.
Surface high pressure will continue to dominate the region tonight,
so clear skies and light winds will allow for good radiational
cooling. Definitely went at or below coolest guidance for tonight`s
lows in most locations. The surface high will push east of the
area on Sunday, allowing south winds to return across the region.
With high pressure aloft resulting in mostly sunny skies, went at
or above the warmest guidance. Most of the area should be in the
lower 80s.
South winds will stay up in the 5 to 10 mph range Sunday night, so
it should be a milder night. Skies will still be no worse than
partly cloudy, so will not go much above guidance. Lows should be
around 60.
As our next potential storm system settles over the Four Corners
region Monday, the flow aloft over our region will become nearly
zonal. A surface cold front will become strung out nearly west to
east well to our north. This should keep us high and dry Monday
and most likely Monday night, too. Will have the slightest of PoPs
for SHRA/TSRA in the Perryville, Pinckneyville, and Mt Vernon
areas on Monday and along the I-64 corridor Monday night, but this
is mainly just to provide a buffer with our surrounding forecast
areas.
The 00Z models do not indicate much increase in clouds Monday, so
temperatures should soar into the 80-85F range, which is well above
guidance. Lows Monday night will continue to trend milder. With a
bit more wind expected, and increasing clouds overnight, lows will
be in the 60-65F range.
.LONG TERM...(Tuesday through Friday)
Issued at 304 AM CDT Sat Apr 23 2016
The upper-level split flow pattern will consist of an active
southern stream across the United States, and a more diffuse polar
jet across northern Canada. A series of shortwaves will eject
northeast out of the Desert Southwest to the central Plains, then
finally into the Great Lakes before weakening. There are still
significant model differences concerning the timing of these
shortwaves and their associated frontal systems. Overall, the
pattern looks rather warm and wet given the storm track to our
north.
As far as the daily specifics, the models are in good agreement for
Tuesday. A narrow 500 mb ridge will pass over the Mississippi Valley
ahead of the first shortwave, which will be emerging into the
southern high Plains. Beneath the ridge aloft, the models continue
to sag a weak frontal boundary south to Interstate 64 by late in the
day Tuesday. The air mass is forecast to be warm and unstable south
of the front, moreso than with other fronts this spring. Therefore,
chance pops will be kept in the forecast despite weak forcing aloft.
The weak frontal boundary should continue south into the Lower Ohio
Valley Tuesday night. Beyond that, the models really start to
diverge on the timing of subsequent frontal passages. The front may
move south of our area before returning north as a warm front during
the middle of the week. A weakening surface low will then move east
across the Midwest Wednesday night and Thursday. A cold front
trailing southwest from the low will move across our region, but
timing differences are quite large. The faster 00z ecmwf is
consistent with the previous NWS forecast and the 12z Fri ecmwf
ensemble mean. However, the slower 00z gfs has support from the
00z gefs. In a nutshell, pops will be in the high chance to likely
category Wed and Wednesday night. Compared with previous systems
this spring, there will be plenty of moisture and instability for
convection. Wind profiles will be moderately strong. A few intense
storms are possible.
Late in the week, another weak shortwave ridge will traverse the
Mississippi and Ohio Valleys between systems. The weak cold front
will be suppressed south of our region. It now appears Friday will
be dry in many areas, but a slight chance pop will be retained
closer to the frontal boundary in the Tennessee border counties
and much of se Missouri. Temperatures should be a little cooler
north of the front, with highs Friday from 70 to 75.
&&
.AVIATION...
Issued at 1231 PM CDT Sat Apr 23 2016
The IFR ceilings at KPAH, KEVV and KOWB will dissipate by 19-21Z as
the low level moisture continues to steadily erode. Thereafter
mainly clear skies and light winds will prevail through the
reminder of the TAF periods as surface high pressure dominates.
Will include some limited fog tonight given very light to brief
calm winds and clear skies.
&&
.PAH Watches/Warnings/Advisories...
IL...None.
MO...None.
IN...None.
KY...None.
&&
$$
UPDATE...RLS
SHORT TERM...DRS
LONG TERM...MY
AVIATION...RS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
512 PM EDT SAT APR 23 2016
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 424 PM EDT SAT APR 23 2016
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW SPLIT FLOW OVER NAMERICA.
IN THE NRN STREAM...A TROF EXTENDS THRU HUDSON BAY INTO SE CANADA
BTWN RIDGING OVER WRN CANADA AND A CLOSED MID LEVEL HIGH CENTERED
JUST SE OF GREENLAND. IN THE SRN STREAM...A TROF IS OVER THE WRN
CONUS WITH RIDGING OUT OVER THE PLAINS. JET STREAK DEVELOPING IN THE
CONFLUENCE BTWN THE SRN STREAM RIDGE AND NRN STREAM TROF OVER SE
CANADA WILL BE ONE OF THE MAIN PLAYERS IN THE WET WEATHER SETTING UP
ACROSS UPPER MI FOR THE NEXT 36-48HRS. WELL OUT AHEAD OF THE WRN
CONUS TROF...WAA/ISENTROPIC ASCENT REGIME SRPEADING OVER THE NRN
PLAINS HAS LED TO SCT -SHRA DEVELOPMENT FROM ND ACROSS NE MN
THIS AFTN. MID CLOUDS ARE PEELING SE FROM THAT AREA ACROSS UPPER MI.
ALTHOUGH CLOUDS HAVE WORKED TO SOMEWHAT LIMIT THE NORMAL DIURNAL
BUILDING OF MIXING HEIGHTS...SFC DWPTS HAVE STILL FALLEN DOWN INTO
THE SINGLE DIGITS/LOW TEENS ACROSS PORTIONS OF INTERIOR W AND CNTRL
UPPER MI.
A GOOD PATTERN FOR SOAKING RAINS WILL BE SETTING UP ACROSS THE AREA
OVER THE NEXT 36-48HRS AS FCST AREA WILL RESIDE IN A SHARP
BAROCLINIC ZONE RESULTING FROM COLD AIR SPREADING ACROSS SE CANADA
UNDER NRN STREAM TROF AND WARM AIR PUSHING TOWARD THE UPPER
MISSISSIPPI VALLEY AHEAD OF THE SRN STREAM WRN CONUS TROF. IN
FACT...MOST OF THE FCST AREA WILL SEE MDT TO HVY RAINFALL AMOUNTS BY
THE TIME THIS WET PERIOD WRAPS UP MON NIGHT. AFOREMENTIONED JET
STREAK WILL BE A KEY MECHANISM FOR PCPN GENERATION AS THE RIGHT
ENTRANCE WILL PROVIDE LARGER SCALE UPPER DIVERGENCE OVER THE AREA.
AT THE LOWER LEVELS...850MB FRONT SETTING UP IN THE VCNTY OF THE
MI/WI BORDER WILL PROVIDE A FOCUS FOR PCPN DEVELOPMENT UNDER
PERSISTENT FGEN/ISENTROPIC ASCENT. PRECIPITABLE WATER INCREASING TO
AROUND 1 INCH (200-250PCT OF NORMAL) WILL THEN SUPPORT THE EXPECTED
MDT/HVY PCPN AMOUNTS. UTILIZED A MIX OF ALL AVBL MODELS TO CONSTRUCT
POPS/PCPN AMOUNTS FOR TONIGHT/SUN AS MOST OF THE GUIDANCE IS FAIRLY
WELL CLUSTERED ON QPF AND TIMING ONSET OF RAIN. PCPN DEVELOPMENT
TONIGHT MAY BE DELAYED MORE SO THAN REFLECTED IN FCST DUE TO THE
VERY DRY AIR OVER THE AREA ATTM. BY 00Z MON...EXPECT PCPN AMOUNTS
RANGING FROM AROUND ONE-THIRD OF AN INCH OVER THE NRN KEWEENAW
PENINSULA AND NE LUCE COUNTY TO 0.90-1.25 INCHES OVER MUCH OF THE W
AND CNTRL FCST AREA. AS FOR TEMPS...LOWS TONIGHT SHOULD RANGE FROM
THE MID 30S TO LWR 40S...WARMEST FAR W. WITH EXPECTATION OF RAIN
PREVAILING FOR MUCH OF THE DAY IN MOST AREAS...LOWERED MAX TEMPS
SOME FOR SUN. HIGHS SHOULD RANGE FROM THE UPPER 30S NW AND NCNTRL TO
MAINLY THE LWR 40S ELSEWHERE.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 511 PM EDT SAT APR 23 2016
COOL CONDITIONS ARE EXPECTED THROUGH THE UPCOMING WEEK...WITH HEAVY
RAIN EXPECTED THROUGH MONDAY.
SUNDAY NIGHT AND MONDAY NIGHT...A STOUT BAROCLINIC ZONE STRETCHING
FROM THE NORTHERN PLAINS TO THE LOWER GREAT LAKES WILL BE THE FOCUS
FOR AN ONGOING ACTIVE PERIOD OF WEATHER. SUBSTANTIAL LOW TO MID-
LEVEL FGEN...WAA...AND LOW-LEVEL MOISTURE TRANSPORT WILL BRING A
CONTINUOUS FEED OF PRECIP ACROSS THE CWA THROUGH AT LEAST MONDAY
MORNING. PWATS APPROACHING 1.5 INCHES ACROSS MN TRACKING TOWARD THE
AREA IN CONJUNCTION WITH AN APPROACHING RIGHT ENTRANCE TO AN UPPER
JET WILL SUPPORT A PERIOD OF MODERATE TO HEAVY RAIN ACROSS ALL BUT
THE KEWEENAW PENINSULA SUNDAY EVENING INTO THE OVERNIGHT HOURS.
MODEL QPF SUNDAY NIGHT ADVERTISES A STRIPE OF 1 TO 2 INCHES WITH
ISOLATED 3 INCH TOTALS ACROSS THE CWA. CURRENT THINKING PUTS THE
HEAVIEST RAIN ALONG A LINE FROM FAR NW WI TO NORTHERN LAKE
MI...INCLUDING IWD...IMT...AND ESC. HOWEVER...MODEL GUIDANCE
CONTINUES TO TREND NORTHWARD WITH THIS SET-UP. IN FACT...LAST
WEEK...LONG TERM GUIDANCE PLACED ALL OF UPPER MI ON THE COLD AND DRY
SIDE OF THE BAROCLINIC ZONE. GIVEN THE MODEL TRENDS...HAVE CONTINUED
THE NORTHWARD PROGRESSION OF THE HIGHEST QPF SUNDAY NIGHT.
AS THE LOW-LEVEL SYSTEM PASSES TO THE SOUTH ON MONDAY...MID-LEVEL
FGEN WILL BE ENHANCED ACROSS THE CWA. THIS WILL FAVOR CONTINUED
MODERATE RAINFALL THROUGH THE MORNING AND POSSIBLY INTO THE
AFTERNOON ACROSS THE SOUTH HALF OF THE CWA. WEAKER FORCING AND DRIER
AIR FILTERING ACROSS THE AREA MONDAY AFTERNOON INTO MONDAY NIGHT
WILL ALLOW FOR A GRADUAL DIMINISHING TREND IN PRECIP AND CLOUD COVER
FROM NORTH TO SOUTH.
WITH THE NORTHWARD TREND IN MODEL GUIDANCE...THE PROSPECTS OF
APPRECIABLE ACCUMULATING SNOW CONTINUE TO DIMINISH. FORECAST
SOUNDINGS INDICATE SLIGHTLY ABOVE FREEZING TEMPS ACROSS THE CWA
THROUGH SUNDAY NIGHT. AS DRYING AND SOME COLDER AIR WORK IN FROM THE
NORTH ON MONDAY...PRECIP MAY SWITCH OVER TO SNOW ACROSS THE HIGH
TERRAIN OF THE NORTH. HOWEVER...WITH A BULK OF THE PRECIP OVER...AND
WITH LATE APRIL DAYTIME HEATING PRESENT...DO NOT EXPECT ANYTHING
MORE THAN UP TO A SLUSHY INCH OF ACCUMULATION ON GRASSY SURFACES
DURING THE DAY.
FORECAST STORM TOTAL QPF TONIGHT THROUGH MONDAY PLACES A SWATH OF 2
TO 3 INCHES SOUTH OF A LINE FROM ONTONAGON TO MARQUETTE TO ST
IGNACE. AMOUNTS QUICKLY DROP OFF TO THE NORTH...WITH LESS THAN A
HALF INCH EXPECTED FOR COPPER HARBOR. GIVEN THE WIDE VARIETY OF QPF
PLACEMENT AMONG MODELS AND ENSEMBLES...IT MUST BE NOTED THAT
LOCALIZED AMOUNTS IN EXCESS OF 4 INCHES WILL BE POSSIBLE THROUGH THE
AFOREMENTIONED PERIOD. GIVEN THE RECENT DRY PERIOD...FLOODING
CONCERNS ARE SOMEWHAT EASED. HOWEVER...WITH LITTLE TO NO
GREENUP...SOILS WILL BECOME SATURATED QUICKLY. HAVE DECIDED TO ISSUE
AN SPS TO ACCOUNT FOR POTENTIALLY VERY HEAVY RAIN AND ELEVATED RIVER
LEVELS THROUGH THE UPCOMING WEEK.
FOR THE REMAINDER OF THE WEEK...COOL AND MOSTLY DRY CONDITIONS WILL
PREVAIL AS HIGH PRESSURE RIDGING EDGES FROM NORTHERN ONTARIO INTO
THE UPPER GREAT LAKES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 139 PM EDT SAT APR 23 2016
VFR CONDITIONS WILL LIKELY HOLD ON THRU THE EVENING AT
KIWD/KCMX/KSAW UNDER ONLY BKN-OVC MID LEVEL CLOUDS. LIGHT RAIN WILL
ARRIVE TONIGHT AND CONTINUE THRU SUN. CIGS WILL BEGIN TO STEADILY
LOWER OVERNIGHT AS STEADIER RAIN ARRIVES...REACHING IFR AT ALL
TERMINALS AROUND 12Z. CONDITIONS MAY CONTINUE TO DETERIORATE FURTHER
TO LIFR DURING THE MORNING HRS...PARTICULARLY AT KCMX/KSAW UNDER
UPSLOPE WINDS. VIS SHOULD MAINLY BE MVFR SUN MORNING...BUT COULD FALL
TO IFR AT TIMES.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 424 PM EDT SAT APR 23 2016
A CLASSIC SET UP FOR BRISK E TO NE WINDS IS SHAPING UP FOR LAKE
SUPERIOR OVER THE NEXT COUPLE OF DAYS AS HIGH PRES BUILDS INTO
NORTHERN ONTARIO AND A WEAK LOW PRES WAVE TRACKS ALONG A FRONT S OF
UPPER MI. WINDS INITIALLY UNDER 20KT THIS EVENING WILL SLOWLY RAMP
UP TONIGHT...MAINLY OVER WESTERN LAKE SUPERIOR. WINDS THEN INCREASE
MORE NOTABLY ACROSS THE LAKE SUN THRU MON MORNING...REACHING GALES
OVER FAR WESTERN LAKE SUPERIOR LATE SUN MORNING THRU MON AFTN AS
COASTAL CONVERGENCE/FUNNELING ENHANCE THE WINDS IN THAT AREA. A GALE
WARNING HAS BEEN POSTED FOR THAT PART OF THE LAKE. ACROSS THE REST
OF LAKE SUPERIOR...WINDS WILL INCREASE TO 20-30KT. WINDS WILL SLOWLY
DIMINISH MON NIGHT/TUE MORNING...BUT MORE SO TUE AFTN/NIGHT AS THE
NORTHERN ONTARIO HIGH PRES BUILDS INTO THE UPPER LAKES. E TO NE
WINDS GENERALLY UNDER 20KT WILL PREVAIL WED/THU. GIVEN THE E TO NE
WIND DIRECTION...WINDS WILL BE STRONGEST OVER WRN LAKE SUPERIOR ON
BOTH OF THOSE DAYS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 11 AM EDT /10 AM CDT/ SUNDAY TO 8 PM EDT /7 PM
CDT/ MONDAY FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KLUBER
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
424 PM EDT SAT APR 23 2016
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 424 PM EDT SAT APR 23 2016
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW SPLIT FLOW OVER NAMERICA.
IN THE NRN STREAM...A TROF EXTENDS THRU HUDSON BAY INTO SE CANADA
BTWN RIDGING OVER WRN CANADA AND A CLOSED MID LEVEL HIGH CENTERED
JUST SE OF GREENLAND. IN THE SRN STREAM...A TROF IS OVER THE WRN
CONUS WITH RIDGING OUT OVER THE PLAINS. JET STREAK DEVELOPING IN THE
CONFLUENCE BTWN THE SRN STREAM RIDGE AND NRN STREAM TROF OVER SE
CANADA WILL BE ONE OF THE MAIN PLAYERS IN THE WET WEATHER SETTING UP
ACROSS UPPER MI FOR THE NEXT 36-48HRS. WELL OUT AHEAD OF THE WRN
CONUS TROF...WAA/ISENTROPIC ASCENT REGIME SRPEADING OVER THE NRN
PLAINS HAS LED TO SCT -SHRA DEVELOPMENT FROM ND ACROSS NE MN
THIS AFTN. MID CLOUDS ARE PEELING SE FROM THAT AREA ACROSS UPPER MI.
ALTHOUGH CLOUDS HAVE WORKED TO SOMEWHAT LIMIT THE NORMAL DIURNAL
BUILDING OF MIXING HEIGHTS...SFC DWPTS HAVE STILL FALLEN DOWN INTO
THE SINGLE DIGITS/LOW TEENS ACROSS PORTIONS OF INTERIOR W AND CNTRL
UPPER MI.
A GOOD PATTERN FOR SOAKING RAINS WILL BE SETTING UP ACROSS THE AREA
OVER THE NEXT 36-48HRS AS FCST AREA WILL RESIDE IN A SHARP
BAROCLINIC ZONE RESULTING FROM COLD AIR SPREADING ACROSS SE CANADA
UNDER NRN STREAM TROF AND WARM AIR PUSHING TOWARD THE UPPER
MISSISSIPPI VALLEY AHEAD OF THE SRN STREAM WRN CONUS TROF. IN
FACT...MOST OF THE FCST AREA WILL SEE MDT TO HVY RAINFALL AMOUNTS BY
THE TIME THIS WET PERIOD WRAPS UP MON NIGHT. AFOREMENTIONED JET
STREAK WILL BE A KEY MECHANISM FOR PCPN GENERATION AS THE RIGHT
ENTRANCE WILL PROVIDE LARGER SCALE UPPER DIVERGENCE OVER THE AREA.
AT THE LOWER LEVELS...850MB FRONT SETTING UP IN THE VCNTY OF THE
MI/WI BORDER WILL PROVIDE A FOCUS FOR PCPN DEVELOPMENT UNDER
PERSISTENT FGEN/ISENTROPIC ASCENT. PRECIPITABLE WATER INCREASING TO
AROUND 1 INCH (200-250PCT OF NORMAL) WILL THEN SUPPORT THE EXPECTED
MDT/HVY PCPN AMOUNTS. UTILIZED A MIX OF ALL AVBL MODELS TO CONSTRUCT
POPS/PCPN AMOUNTS FOR TONIGHT/SUN AS MOST OF THE GUIDANCE IS FAIRLY
WELL CLUSTERED ON QPF AND TIMING ONSET OF RAIN. PCPN DEVELOPMENT
TONIGHT MAY BE DELAYED MORE SO THAN REFLECTED IN FCST DUE TO THE
VERY DRY AIR OVER THE AREA ATTM. BY 00Z MON...EXPECT PCPN AMOUNTS
RANGING FROM AROUND ONE-THIRD OF AN INCH OVER THE NRN KEWEENAW
PENINSULA AND NE LUCE COUNTY TO 0.90-1.25 INCHES OVER MUCH OF THE W
AND CNTRL FCST AREA. AS FOR TEMPS...LOWS TONIGHT SHOULD RANGE FROM
THE MID 30S TO LWR 40S...WARMEST FAR W. WITH EXPECTATION OF RAIN
PREVAILING FOR MUCH OF THE DAY IN MOST AREAS...LOWERED MAX TEMPS
SOME FOR SUN. HIGHS SHOULD RANGE FROM THE UPPER 30S NW AND NCNTRL TO
MAINLY THE LWR 40S ELSEWHERE.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 401 AM EDT SAT APR 23 2016
LOOKS LIKE THE CHILLY...ACTIVE WX PATTERN IS STILL ON TRACK FOR LATE
THIS WEEKEND INTO EARLY NEXT WEEK AS A VERY TIGHT BAROCLINIC ZN WL
SETUP ACRS THE UPR GREAT LKS NEAR THE CONFLUENCE ZN BTWN NRN BRANCH
NW FLOW IN CANADA AND AN ACTIVE SRN BRANCH WSW FLOW OVER THE NRN
CONUS. SOME MDT TO HEAVY PCPN IS LIKELY TO FALL OVER AT LEAST THE S
HALF OF UPR MI...WHICH WL BE CLOSER TO A STNRY FNT RUNNING W-E THRU
THE UPR MIDWEST AND MOISTER AIR TO THE S. IF ENUF COLD AIR IN THE
NNE FLOW BTWN BLDG HI PRES INTO NRN ONTARIO AND THE LOWER PRES TO
THE S ADVECTS INTO THE CWA AND THIS AIR IS NOT EXCESSIVELY DRY...
THERE COULD BE SOME ACCUMULATING WET SN OVER MAINLY THE HIER TERRAIN
OF NW UPR MI FM LATE SUN NGT INTO MON NGT. BUT AS IS ALWAYS THE CASE
WHEN AN AREA IS NEAR THE NRN EDGE OF A PCPN AREA WITH PLENTY OF DRY
AIR JUST TO THE N...SMALL CHANGES IN THE FCST PARAMETERS MAY HAVE A
SGNFT IMPACT ON THE OUTCOME. AS THE ONTARIO HI PRES BLDS INTO THE
UPR LKS ON TUE...EXPECT QUITE BUT STILL RELATIVELY CHILLY WX INTO
MID WEEK. ANOTHER DISTURANCE/LO PRES MOVING NE FM THE PLAINS MAY
BRING MORE PCPN LATER WED/THU...BUT THERE IS GREAT UNCERTAINTY AS TO
WHETHER THE NW FLOW ALOFT ARND A DEEP UPR TROF CENTERED IN QUEBEC WL
SHUNT THIS SYSTEM TO THE S. THIS PERSISTENT DEEP TROF WL MAINTAIN
BLO NORMAL TEMPS FOR UPR MI THRU THIS WEEK.
SUN/MON...UPR MI IS FCST TO BE UNDER SHARP BAROCLINIC ZN UNDER
CONFLUENCE ZN BTWN COLD NRN BRANCH NW FLOW DOMINATING QUEBEC AND A
SRN BRANCH WSW FLOW OVER THE NRN CONUS. ALTHOUGH THE CONFLUENT UPR
FLOW WELL TO THE NE OF SLOW MOVING...STRONGER SRN BRANCH SHRTWV
RIDING ENEWD THRU THE NRN PLAINS WL TEND TO SHEAR OUT/WEAKEN THAT
SHRTWV AND OTHER DISTURBANCES THAT EJECT OUT AHEAD OF IT...MOST OF
THE MEDIUM RANGE MODELS GENERATE SOME MDT TO HEAVY PCPN OVER MAINLY
THE S HALF OF THE CWA. WAA TO THE N OF THE FNT...UPR DVGC IN RRQ OF
120KT H3 JET MAX JUST S OF JAMES BAY AS WELL AS SHARP...PERSISTENT
LO-MID LVL FGEN N OF THE H85 WARM/STNRY FNT STRETCHING E ACRS WI FM
LO IN THE NRN PLAINS AND AXIS OF PWAT AOA AN INCH /ABOUT 225 PCT OF
NORMAL/ OVER THE SRN CWA LOOK TO BE THE ENHANCEMENT FACTORS THAT WL
SUPPORT THIS HEAVIER PCPN AND OVERCOME THE NEGATIVES ASSOCIATED WITH
THE UPR CONFLUENCE. SOME OF THE MODELS SHOW AS MUCH AS 2-3 INCHES OF
PCPN FALLING OVER PORTIONS OF THE CWA DURING THE SUN THRU MON TIME.
SOME OF THE COLDER MODELS` FCST SDNGS/THERMAL FIELDS WITH H85 TEMPS
FALLING BLO 0C INDICATE AT LEAST SOME OF THE PCPN NEAR THE NRN EDGE
OF THE PCPN AREA WL FALL IN THE FORM OF SN AT TIMES. HOWEVER...
GUIDANCE HAS BEEN INCONSISTENT ON THE DEGREE OF COOLING AS WELL AS
THE IMPACT OF MUCH DRIER AIR THAT WL BE PRESENT JUST TO THE N AND
COULD ADVECT INTO THE CWA IN THE STEADY NNE FLOW TO THE S OF HI PRES
BLDG INTO NW ONTARIO. BEST CHC FOR SOME DRYING THAT MAY LIMIT
POPS/QPF AT LEAST TEMPORARILY LOOKS TO BE LATER ON SUN IN THE WAKE
OF A SHEARING DISTURBANCE PASSING TO THE E. THE BEST CHC FOR SOME
ACCUMULATING SN WL BE LATE SUN NGT INTO MON MRNG OVER THE HIER
TERRAIN OF THE W HALF WHEN THE SLOWLY APRCHG MAIN SHRTWV WL ENHANCE
UVV/DYNAMIC COOLING IN THE ABSENCE OF SOLAR WARMING...UNLESS LLVL
DRYING FM THE N NEGATIVELY IMPACTS PCPN POTENTIAL. NOT OUT OF THE
QUESTION THERE COULD BE A COUPLE INCHES OF WET...HEAVY SN IN THESE
AREAS. TEMPS THRU THIS TIME WL RUN BLO TO WELL BLO NORMAL...
ESPECIALLY THE MAX TEMPS.
MON NGT...AS THE SHRTWV RIDING TO THE NE BEGINS TO SHEAR OUT TO THE
ESE...LARGER SCALE DVNA/MID LVL DRYING/DEEP LYR QVECTOR DVGC IN ITS
WAKE WL TEND TO DIMINISH LINGERING PCPN NW-SE. WITH THE ARRIVAL OF
DRIER LLVL AIR ASSOCIATED WITH THE ONTARIO HI BLDG TOWARD THE UPR
LKS...SKIES MAY CLR OUT AS WELL AND ALLOW MIN TEMPS TO FALL WELL
INTO THE 20S.
TUE/TUE NGT...AS THE ONTARIO HI PRES EXPANDS INTO THE UPR LKS UNDER
CONFLUENT NW FLOW ALF BTWN DEEP UPR LO OVER QUEBEC AND AN APRCHG RDG
SHIFTING E THRU THE NRN PLAINS...EXPECT MOCLR SKIES. H85 TEMPS
RECOVERING TO NEAR 0C AND PLENTY OF SUNSHINE SHOULD ALLOW MAX TEMPS
TO RECOVER AT LEAST CLOSE TO 50 AWAY FM THE COOLING INFLUENCE OF THE
LKS. TUE NGT IS LIKELY TO BE ANOTHER CHILLY ONE WITH THE HI PRES
STILL DOMINATING.
WED/THU...ATTENTION WL THEN TURN TO WHETHER ANOTHER SRN BRANCH
SHRTWV MOVING NE THRU THE PLAINS WL IMPACT THE CWA DURING THE MID
WEEK. HOW FAR NE THIS DISTURBANCE/ACCOMPANYING PCPN WL MOVE WL
DEPEND ON THE STRENGTH OF THE PERSISTENT...DEEP CLOSED LO IN QUEBEC.
ALTHOUGH MANY OF THE MEDIUM RANGE MODELS BRING ASSOCIATED PCPN INTO
THE UPR LKS...SUSPECT THE DRIER RECENT CNDN MODELS ARE ON THE RIGHT
TRACK WITH A MORE CONFLUENT NW FLOW THRU ONTARIO ALLOWING A MORE
PERSISTENT SFC HI PRES RDG TO INFLUENCE THE UPR LKS AS SUGGESTED BY
THE 12Z GFS ENSEMBLE MEAN. BUT WL FOLLOW MODEL CONSENSUS GIVEN THE
MODEL SPREAD SO FAR OUT IN THE FCST PERIOD.
FRI...UPR RDGING/SFC HI PRES BLDG INTO THE UPR LKS WL BRING A RETURN
OF DRY AND SEASONABLE WX. WITH H85 TEMPS FCST WITHIN A FEW DEGREES
OF 0C...BLO NORMAL TEMPS WL CONTINUE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 139 PM EDT SAT APR 23 2016
VFR CONDITIONS WILL LIKELY HOLD ON THRU THE EVENING AT
KIWD/KCMX/KSAW UNDER ONLY BKN-OVC MID LEVEL CLOUDS. LIGHT RAIN WILL
ARRIVE TONIGHT AND CONTINUE THRU SUN. CIGS WILL BEGIN TO STEADILY
LOWER OVERNIGHT AS STEADIER RAIN ARRIVES...REACHING IFR AT ALL
TERMINALS AROUND 12Z. CONDITIONS MAY CONTINUE TO DETERIORATE FURTHER
TO LIFR DURING THE MORNING HRS...PARTICULARLY AT KCMX/KSAW UNDER
UPSLOPE WINDS. VIS SHOULD MAINLY BE MVFR SUN MORNING...BUT COULD FALL
TO IFR AT TIMES.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 424 PM EDT SAT APR 23 2016
A CLASSIC SET UP FOR BRISK E TO NE WINDS IS SHAPING UP FOR LAKE
SUPERIOR OVER THE NEXT COUPLE OF DAYS AS HIGH PRES BUILDS INTO
NORTHERN ONTARIO AND A WEAK LOW PRES WAVE TRACKS ALONG A FRONT S OF
UPPER MI. WINDS INITIALLY UNDER 20KT THIS EVENING WILL SLOWLY RAMP
UP TONIGHT...MAINLY OVER WESTERN LAKE SUPERIOR. WINDS THEN INCREASE
MORE NOTABLY ACROSS THE LAKE SUN THRU MON MORNING...REACHING GALES
OVER FAR WESTERN LAKE SUPERIOR LATE SUN MORNING THRU MON AFTN AS
COASTAL CONVERGENCE/FUNNELING ENHANCE THE WINDS IN THAT AREA. A GALE
WARNING HAS BEEN POSTED FOR THAT PART OF THE LAKE. ACROSS THE REST
OF LAKE SUPERIOR...WINDS WILL INCREASE TO 20-30KT. WINDS WILL SLOWLY
DIMINISH MON NIGHT/TUE MORNING...BUT MORE SO TUE AFTN/NIGHT AS THE
NORTHERN ONTARIO HIGH PRES BUILDS INTO THE UPPER LAKES. E TO NE
WINDS GENERALLY UNDER 20KT WILL PREVAIL WED/THU. GIVEN THE E TO NE
WIND DIRECTION...WINDS WILL BE STRONGEST OVER WRN LAKE SUPERIOR ON
BOTH OF THOSE DAYS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 11 AM EDT /10 AM CDT/ SUNDAY TO 8 PM EDT /7 PM
CDT/ MONDAY FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KC
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS DULUTH MN
1254 PM CDT SAT APR 23 2016
.UPDATE...
ISSUED AT 1034 AM CDT SAT APR 23 2016
UPDATED THE FORECAST THROUGH EARLY SUNDAY...MAINLY FOCUSING ON THE
TIMING OF THE PRECIPITATION. LEANED ON THE EXPERIMENTAL HRRR AND
RAP13 FOR THE BLEND BECAUSE THE TWO MODELS WERE PERFORMING THE
BEST WITH WHAT WAS OCCURRING EARLIER THIS MORNING. BOTH THE HRRR
AND RAP13 WERE REFLECTING THE BAND OF SHOWERS ACROSS THE WEST
CENTRAL FORECAST AREA...THEN LIFTING THE BAND NORTH AND EAST INTO
THIS AFTERNOON. MUCH OF THE PCPN THIS AFTERNOON SHOULD BE LIMITED
TO FAR NORTHERN MINNESOTA...AND THEN ONLY BEGIN TO SPREAD INTO THE
REST OF THE NORTHLAND LATE TODAY.
THE PREVIOUS FORECAST HAD SLEET AND FREEZING RAIN OVER THE
ARROWHEAD TONIGHT AND EARLY SUNDAY. HOWEVER...THE LATEST
RAP13/NAM12/GFS20 MODEL SOUNDINGS HEAVILY FAVOR ONLY RAIN OR
SNOW...SO REMOVED THE SLEET AND FREEZING RAIN. THE PREVIOUS
FORECAST ALSO HAD A MIXTURE OF RAIN AND SNOW FOR THE LAKE SUPERIOR
AREA SUNDAY AFTERNOON...BUT THE TEMPERATURES ALOFT HEAVILY SUPPORT
RAIN. WHILE COLD NEAR SURFACE TEMPERATURES MAY APPROACH THE
FREEZING MARK...THE RELATIVELY WARM TEMPERATURES ALOFT SHOULD
ENSURE THE FALLING PCPN REMAINS RAIN.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 401 AM CDT SAT APR 23 2016
THE SHORT TERM FORECAST FOCUS WILL BE ON PRECIPITATION CHANCES/TYPE
THROUGH SUNDAY.
A SURFACE LOW IN EASTERN MONTANA IS FORECAST TO MOVE SOUTHEAST INTO
SOUTH DAKOTA BY 12Z SUNDAY THEN MOVE ONLY SLOWLY EAST ON SUNDAY.
MOISTURE WILL SURGE INTO THE NORTHLAND TODAY INTO SUNDAY WITH PWAT
VALUES INCREASING FROM A THIRD TO HALF INCH OVER THE AREA THIS
MORNING...TO THREE QUARTERS TO NEAR AN INCH AND A QUARTER BY 12Z
SUNDAY. PERSISTENT WAA/FGEN AS WELL AS SHORTWAVE ENERGY TODAY INTO
SUNDAY WILL CAUSE PRECIPITATION TO INCREASE ACROSS THE NORTHLAND.
PRECIPITATION WILL BECOME WIDESPREAD TONIGHT INTO SUNDAY. A
STRONG GRADIENT WITH PRESSURE FALLS OFF TO THE SOUTHWEST WILL
CAUSE THE WIND TO INCREASE AROUND LAKE SUPERIOR...WITH STRONG
WINDS OVER AND CLOSE TO LAKE SUPERIOR DEVELOPING LATER TONIGHT
INTO MONDAY.
PRECIPITATION TYPE WILL BE A CHALLENGE OVER PORTIONS OF THE
NORTHLAND...MAINLY TONIGHT INTO SUNDAY IN THE ARROWHEAD TO THE HEAD
OF LAKE SUPERIOR. JUST SHOWERS ARE EXPECTED TODAY AS THE BOUNDARY
LAYER WARMS...BUT TONIGHT THE LOW LEVELS WILL COOL AROUND PORTIONS
OF LAKE SUPERIOR AND WITH INCREASING EAST/NORTHEAST
WINDS...ADDITIONAL COOLING CAN BE EXPECTED AROUND THE LAKE. FORECAST
SOUNDINGS AND SURFACE TEMPERATURES SUGGEST A MIX FROM RAIN OR SNOW
TO SLEET OR EVEN SOME FREEZING RAIN WILL BE POSSIBLE LATER TONIGHT
INTO SUNDAY MORNING OVER PORTIONS OF THE ARROWHEAD. AT THIS
TIME...IT LOOKS LIKE TEMPERATURES THROUGH SUNDAY MORNING WILL REMAIN
WARM ENOUGH FOR JUST RAIN IN THE TWIN PORTS AND SOUTH SHORE AREAS. A
MIX MAY DEVELOP LATE SUNDAY AFTERNOON/EVENING AT THE HEAD OF LAKE
SUPERIOR AS STRONG EASTERLY FLOW AND PERSISTENT RAIN COOLS SURFACE
TEMPERATURES IN THOSE AREAS. AT THIS TIME...SIGNIFICANT ICE IS NOT
EXPECTED...BUT IF SURFACE TEMPERATURES HAPPEN TO COOL ABOUT 2 OR 3
DEGREES MORE THAN EXPECTED...THERE COULD BE SOME ICING THAT DEVELOPS.
SIGNIFICANT RAINFALL IS EXPECTED THROUGH MONDAY...WITH AMOUNTS
RANGING FROM A THIRD OF AN INCH ALONG THE INTERNATIONAL BORDER...TO
1.5 TO 2.5 INCHES FROM THE TWIN PORTS AND OVER NORTHERN WISCONSIN.
WE EXPECT HIGHS TODAY TO RANGE FROM THE LOWER TO MID SIXTIES IN THE
BRAINERD LAKES INTO NORTHWEST WISCONSIN...TO THE LOWER FIFTIES OVER
FAR NORTHERN MINNESOTA. INCREASING WINDS OFF OF LAKE SUPERIOR WILL
KEEP ALL AREAS AROUND THE LAKE MUCH COOLER...WITH ONLY LOWER TO MID
FORTIES EXPECTED. SUNDAY WILL BE EVEN COOLER WITH STRONGER WINDS.
THE LAKE INFLUENCE WILL BE FELT WELL INLAND TO MOOSE LAKE...SOLON
SPRINGS AND IRON RIVER...AND WELL INTO THE ARROWHEAD. TEMPERATURES
HERE WILL ONLY BE IN THE THIRTIES...WITH MID FORTIES TO LOWER
FIFTIES ELSEWHERE.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 401 AM CDT SAT APR 23 2016
PRECIPITATION WILL CONTINUE SUNDAY NIGHT AND MONDAY WITH THE STRONG
SURFACE LOW SLOWLY MOVING FROM CENTRAL SOUTH DAKOTA...EAST TO
NORTHWEST IOWA BY EARLY MONDAY MORNING AND ON TO NORTHWEST ILLINOIS
BY MONDAY EVENING. STRONG FRONTOGENESIS AND ISENTROPIC LIFT WILL
CONTINUE ACROSS THE SOUTHERN HALF OF THE FORECAST AREA SUNDAY NIGHT
THROUGH MONDAY. FOR NOW...IT APPEARS THE GREATEST POPS SHOULD BE
SUNDAY NIGHT...GRADUALLY DIMINISHING THROUGH MONDAY. EASTERLY FLOW
OFF LAKE SUPERIOR AND COLDER...DRIER AIR MOVING IN FROM THE AREA
FROM THE NORTHEAST MAY TURN THE PRECIPITATION OVER TO A WINTRY MIX
ALONG THE NORTH SHORE OR FARTHER INLAND NORTH OF THE IRON RANGE.
SURFACE TEMPERATURES WILL BE CRITICAL DURING THIS TIME RANGE...AND
THERE IS SOME POTENTIAL FOR FREEZING RAIN. HAVE LEFT THE FREEZING
RAIN OUT OF THE FORECAST FOR THESE PERIODS FOR NOW...BUT WILL HAVE
TO RE-EVALUATE THIS OVER THE NEXT DAYS. MONDAY NIGHT THE
PRECIPITATION WILL GRADUALLY END FROM WEST TO EAST...LEAVING DRY
CONDITIONS FOR TUESDAY...WITH WARMER CONDITIONS FOR TUESDAY THAN
MONDAY.
TUESDAY NIGHT THROUGH FRIDAY THERE ARE SOME SIGNIFICANT DIFFERENCES
IN THE MODELS. A STRONG UPPER LOW OVER THE PLAINS WILL GRADUALLY
MOVE EAST THROUGH THE PERIOD...WITH THE GFS KEEPING THE LOW TIGHTER
AND FARTHER TO THE NORTH THAN THE MORE OPEN AND FASTER MOVING ECMWF.
THE GFS SOLUTION KEEPS PRECIPITATION GOING OVER THE FORECAST AREA
WEDNESDAY THROUGH THURSDAY NIGHT...WHERE THE ECMWF KEEPS US DRY
THROUGH MUCH OF THE PERIOD WITH THE UPPER LOW TOO FAR NORTH TO
AFFECT US. THIS FARTHER NORTH GFS SOLUTION IS RELATIVELY NEW...AS
PREVIOUS SOLUTIONS ALSO KEPT THIS UPPER LOW TOO FAR SOUTH TO AFFECT
THE FORECAST AREA. HAVE KEPT TO THE BLENDED SOLUTION FOR POPS...BUT
WE MAY BE ABLE TO LOWER THEM AGAIN. TEMPERATURES GRADUALLY WARM
THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1245 PM CDT SAT APR 23 2016
VFR CONDITIONS TODAY WILL GIVE WAY TO LOWERING CEILINGS THIS
EVENING...AND SHOWERS WITH WIDESPREAD MVFR CONDITIONS AFTER 06Z.
THUNDER IS POSSIBLE FOR KBRD...KDLH AND KHYR OVERNIGHT. ALTHOUGH
HAVE LEFT OUT OF THE TAF FOR NOW DUE TO UNCERTAINTIES IN COVERAGE
AND TIMING. WINDS WILL INCREASE OUT OF THE EAST SUNDAY WITH
FREQUENT GUSTS AROUND 25 KNOTS. WINDS WILL BE STRONGER NEAR LAKE
SUPERIOR.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 48 35 37 32 / 10 80 80 90
INL 52 36 50 30 / 60 70 10 10
BRD 65 44 45 37 / 20 70 70 90
HYR 62 46 50 38 / 0 70 90 90
ASX 55 39 41 35 / 10 80 90 90
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...GALE WATCH FROM SUNDAY MORNING THROUGH MONDAY AFTERNOON FOR
LSZ140>147.
SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 10 AM CDT
SUNDAY FOR LSZ143>146.
&&
$$
UPDATE...GROCHOCINSKI
SHORT TERM...MELDE
LONG TERM...LE
AVIATION...GRANING
Area Forecast Discussion
National Weather Service Springfield MO
328 PM CDT SAT APR 23 2016
...Beautiful Weather This Weekend...Increasing Confidence for
Strong to Severe Storms Next Week...
.SHORT TERM...(This evening through Sunday Night)
Issued at 249 PM CDT Sat Apr 23 2016
Very pleasant weather was being observed across the entire area
this afternoon with sunny skies and light winds. Temperatures have
warmed up into the middle and upper 70s area wide. Another nice
evening is on the way followed by another nice day on Sunday with
highs around 80. It will be breezy as a storm system develops
across the High Plains region into the northern Plains. A strong
pressure gradient will cause southerly winds possibly gusting up
to 30 mph at times over the western half of the area.
Strong to severe convection will develop just our northwest across
Kansas by tomorrow evening along a pseudo front and dry line.
This convection will try to move eastward Sunday night but run out
of energy and atmospheric support. Will continue to mention the
possibility of a strong storm or two possibly reaching portions
of southeast Kansas and extreme western Missouri very late Sunday
night. Otherwise the convection will decrease to spotty showers
and isolated thunder across the area by Monday morning.
.LONG TERM...(Monday through Saturday)
Issued at 249 PM CDT Sat Apr 23 2016
Monday will be partly cloudy to mostly cloudy and more humid. The
front that ran out of energy and support Sunday night will stall
out across the area or just northwest of the area on Monday. With
this boundary in the general area with weak forcing and some weak
instability to work with...will continue a chance of a few
scattered showers and isolated thunder Monday through early on
Tuesday. This stalling out of the boundary will be key to allowing
low level and mid level moisture to continue to increase across
the region.
The main concern and attention will be the stronger storm system
developing on Tuesday and Wednesday. A good agreement with the
forecast models show a strong negatively tilted trough moving out
of the Rocky Mountains to the Central Plains on Tuesday afternoon.
Surface dewpoints will climb into the middle 60s across the region
with forecast cape somewhere from 3000 to 4000 J/KG. Bulk shear
magnitudes will be around 35 knots Tuesday evening and slow
increasing Tuesday night into Wednesday. There may be initially a
strong cap Tuesday afternoon. Still a few questions on timing of
when convection will develop or move into the area Tuesday evening
and Tuesday night. But confidence is slowly increasing that the
region will see severe weather late Tuesday through Wednesday.
The ECMWF is a little further southeast of the position than the
GFS with the upper level system and storm system. All models show
a possible outbreak of severe weather developing to our west late
Tuesday afternoon into the evening. This convection will begin to
move into our southeast Kansas counties and extreme western
Missouri very late Tuesday evening into the overnight hours. All
modes of severe weather appear possible west of the Highway 65
corridor with large hail...damaging winds...and a few tornadoes
possible.
The convection may be ongoing or decreasing by early Wednesday
morning. The question remains if the atmosphere will be able to
destabilize again by midday or Wednesday afternoon. The models
have slowed down the progression of the dryline or front which now
may hang out across western Missouri on Wednesday. The better
potential for severe weather on Wednesday will remain along and
east of Highway 65 Wednesday afternoon with all modes of severe
weather possible again. Areawide total forecast rainfall will
average about an inch to up to an inch and half possible.
The front finally moves through late Wednesday night and moves
out the showers and storms to the east. The front stalls out to
our south on Thursday with dry weather expected across the area.
The boundary moves northward as a warm front on Friday and
Saturday bringing another round of showers and storms to the
region late in the week. The weather pattern looks active and
storm heading into next weekend as well.
&&
.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
Issued at 1159 AM CDT Sat Apr 23 2016
VFR conditions are expected through the period as surface high
pressure continues to drift eastward and an upper level ridge
moves across the area. Main forecast concern is gusty winds
beginning after sunrise on Sunday as the next approaching system
begins to tighten up the surface pressure gradient. Winds should
develop gusts after 13z at KSGF/KJLN but believe that it will be
later in the afternoon...after the end of the forecast
period...for KBBG.
&&
.SGF Watches/Warnings/Advisories...
MO...NONE.
KS...NONE.
&&
$$
SHORT TERM...Griffin
LONG TERM...Griffin
AVIATION...Gaede
[top]
Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
310 PM CDT SAT APR 23 2016
.Short Term...(This Evening through Monday Night)
Issued at 309 PM CDT SAT APR 23 2016
Short Term (Tonight through Monday night):
The main concern in the short term will be the potential for a few
strong and isolated severe storms on Sunday evening into Sunday
night. Tonight, however will be much less interesting and quite
pleasant as modest southerly winds will hold temperatures in the mid
50s to lower 60s. The system, an upper level trough, that will bring
thunderstorms to the area Sunday will move from western Wyoming to
near the WY/SD/NE by Saturday night. This will force a cold front into
the western Plains. Thunderstorms will develop along this front
tonight across western Kansas. This storms will progress across
Kansas overnight enhanced by a 50-60kt SSWly nocturnal LLJ. By early
Sunday morning the LLJ will veer to the southwest and storms will
begin to approach northeastern KS and northwestern MO. However,
these storms will be weakening as they approach and there may just
be a few isolated storms or residual shower to make it into the
extreme NW CWA Sunday morning. However, by Sunday afternoon, a dry
line will exist across central Kansas with the attendant cold front
lagging to the west across the western High Plains. Thunderstorms
are expected to develop out ahead of the cold front across central
Kansas during the afternoon and move eastward. These storms will
have the potential to be strong with perhaps isolated severe storms
possible mainly across northwestern MO/northeastern KS where
dewpoints will be near 60 degrees, modest instability of 500-
800J/kg, and steep mid-level lapse rates will exist. However, shear
is not impressive and as previously mentioned instability is merely
modest. Consequently, strong storms will be possible and perhaps
even a marginally severe storm capable of producing large hail or
damaging winds. Storms will weaken Sunday night as storms move into
a more stable environment and the upper level trough continues to
weak as it moves into the Upper Midwest. On Monday, the cold front
associated with the upper level system will sag through the area.
However, will little forcing the front will sag through the area
with little activity expected. The best chance for storms would
occur head of the front where modest instability will reside. Monday
night the cold front will sink south of the area and become
stationary. A few thunderstorms may develop north of the stationary
boundary Monday as a SW 40kt LLJ overrides the boundary. These
thunderstorms may affect the southern CWA depending on the location
of the front.
.Long Term...(Tuesday through Saturday)
Issued at 309 PM CDT SAT APR 23 2016
Tuesday evening and Wednesday will bring another round of showers
and possibly severe thunderstorms to the CWA. The most recent NAM
and GFS runs show Tuesday morning and early afternoon warm and humid
with precipitation mainly staying just south of the WFO. A negatively
tilted low pressure trough stations itself over eastern CO/western KS
Tuesday afternoon. A cold front will move east through Kansas
Wednesday afternoon, and an associated warm front will be located E-W
through our forecast area late Tuesday bringing low- level moisture
with it. Dew point temperatures will range from low 50s north of the
front spreading south to the mid-60s. We will also have decent
instability and shear with CAPE values around 1000-2000 J/kg and
30-50 kt 0-6 km bulk shear. A combination of high CAPE and shear may
lead to potentially severe thunderstorms ahead of the cold front. The
development and location of severe weather will depend on the timing
of convection and the frontal passage, which will become more clear
as we get closer to the event. For now, the GFS and Euro models show
precipitation starting in eastern KS and moving east through the WFO
late Tuesday night through Wednesday morning. Convection could
continue throughout Wednesday as CAPE values are expected to stay
above 1000 J/kg throughout Wednesday afternoon.
High temperatures will continue to be in the mid 70s through
Wednesday, but will drop to the mid-high 60s for Thursday and Friday
after the cold front passes. Low temperatures will drop Thursday and
Friday mornings to the high 40s to low 50s. Thursday is expected to
be dry before another upper low system may cause more precipitation
late Friday into Saturday.
&&
.Aviation...(For the 18Z TAFS through 18Z Sunday Afternoon)
Issued at 1230 PM CDT SAT APR 23 2016
VFR conds will prevail through the pd with mainly just sct high
clouds expected. Winds will pick up out of the south this afternoon
to 10-15kts with gusts to around 20kts. Winds will lose their gusts
this evening but still remain around 10-15kts. However, tomorrow
morning winds will again increase to 15-20kts with gusts to 25-30kts.
LLWS may be a marginal concern tonight as winds at 2kft will be out
of the SSW at 35-40kts btn 06Z-14Z and, may need to be added to the
TAF at the 00Z issuance.
&&
.EAX Watches/Warnings/Advisories...
KS...None.
MO...None.
&&
$$
Short Term...73
Long Term...Chandler/CDB
Aviation...73
[top]
Area Forecast Discussion
National Weather Service Saint Louis MO
257 PM CDT SAT APR 23 2016
.SHORT TERM... (Through Late Tonight)
Issued at 255 PM CDT Sat Apr 23 2016
Surface ridge extending from MI southwest into eastern MO will move
eastward. The stratus clouds across southeast IL should continue to
dissipate late this afternoon. Few-scattered diurnal cumulus
clouds, especially across parts of northeast and central MO will
dissipate early this evening with the loss of daytime heating.
Mainly just a little high level cloudiness tonight. Lows tonight
will be warmer than the previous night, mainly due to southeast
surface winds on the backside of the surface ridge. The warmest
temperatures will be across central MO with the coolest temperatures
in southwest IL. Lows tonight will be about 5 to 10 degrees above
normal for late April.
GKS
.LONG TERM... (Sunday through Next Saturday)
Issued at 255 PM CDT Sat Apr 23 2016
Dry and warmer weather to persist on Sunday, but will see an
increase in high clouds as next weather system approaches region.
With gusty south winds will see highs in the upper 70s to low 80s.
Sunday night rain chances to approach region, but models are a bit
slower with onset, so lowered pops just a bit. Then Monday through
Tuesday, frontal boundary to slowly slide south through area with
mainly scattered showers and thunderstorms. Front to stall out
across southern Missouri on Tuesday. Highs will be in the upper 70s
to low 80s on Monday, then dip down into the low 70s to low 80s
Tuesday and Wednesday.
Decent instability north of front Tuesday night, so could see
elevated activity develop and slide along boundary on nose of decent
low level jet. Large hail would be the main threat with this round
of storms.
Models are still indicating decent instability, CAPES in excess of
1500 J/kg and shear with system Wednesday afternoon, Wednesday night
as warm front lifts north through forecast area. All of this still
points to our first real potential severe weather day this spring,
but a lot can happen in 5 days. Stay tuned to further updates.
With everything a bit slower, main cold front to slide through early
on Thursday with precipitation tapering off to just slight chance
pops through Friday. Then extended models showing next system
lifting northeast towards forecast area Friday night and Saturday
with increasing chances of showers and thunderstorms once again.
Once system exits region on Thursday, will see precipitation taper
off. Even though it will be a bit cooler Thursday, highs will still
be a bit above normal in the mid 60s to upper 70s. Extended models
beginning to indicate another system approaching region on Friday,
but timing is hard to pin down. So for now kept slight chance pops.
Byrd
&&
.AVIATION... (For the 18z TAFs through 18z Sunday Afternoon)
Issued at 1104 AM CDT Sat Apr 23 2016
Surface ridge extending from the Great Lakes region southwest
into eastern MO will shift eastward this period. The low level
cloudiness over eastern IA into northeast MO should remain north
of UIN this afternoon. The stratus cloudiness across southeast IL
should gradually dissipate this afternoon with daytime heating,
mixing and drying and remain east of the St Louis metro area.
There may be a few diurnal cumulus clouds at the taf sites this
afternoon. There will be a little high level cloudiness late
tonight and Sunday morning. Southeasterly surface winds should
strengthen at UIN and COU through the forecast period as the
surface pressure gradient gradually tightens, becoming more
southerly on Sunday. Light northeast wind in the St Louis metro
area will also strengthen as well through the period, veering
around to a southeast direction by early this evening, then
southerly Sunday morning. There will be some LLWS conditions in
UIN and COU very late tonight and early Sunday morning as a
southwesterly low level jet translates eastward into northwest MO
with both speed and directional shear in the lowest 1000 feet.
Specifics for KSTL: Stratus clouds across southeast IL should
gradually dissipate this afternoon and remain east-southeast of
STL. Few diurnal cumulus clouds may develop this afternoon due to
daytime heating, then dissipate early this evening. There will be
some high level cloudiness late tonight and Sunday. Light
northeast wind will increase in speed to 8-10 kts by late this
afternoon or early this evening as it veers around to a southeast
direction. The surface wind will become southerly Sunday morning
and possibly gusty Sunday afternoon.
GKS
&&
.PRELIMINARY POINT TEMPS/POPS...
Saint Louis 55 82 63 81 / 0 0 20 30
Quincy 56 81 61 79 / 5 5 30 30
Columbia 57 81 60 78 / 5 5 20 30
Jefferson City 58 82 61 80 / 5 5 20 30
Salem 51 79 60 80 / 0 0 10 20
Farmington 52 79 60 79 / 0 0 10 20
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...None.
IL...None.
&&
$$
WFO LSX
Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
1230 PM CDT SAT APR 23 2016
.Discussion...
Issued at 412 AM CDT SAT APR 23 2016
Today - Tonight:
In the very near term will be dealing with patchy dense fog over the
northeast 1/2 of the CWA. The fog and stratus is forming under a
surface ridge with river valleys and low lying areas the most
susceptible. The latest NAM/RAP 925mb condensation pressure deficit
prog best depict the low clouds with the SREF favoring more
widespread dense fog further north in IA.
Otherwise, for today expect a nice warm up as pressure falls over
the Central Plains induce increasing southerly winds. Should see
decent mixing with a dry adiabatic lapse rate yielding highs around
10 degrees above average. Upper level ridging spreading east into
the CWA will provide for continued dry conditions.
Increasing warm air advection aloft will ensue across KS and NE this
evening with scattered elevated convection possibly grazing far
northwest MO towards sunrise Sunday morning. Any convection which
reaches this region should fall apart Sunday morning with convective
debris and mid level accas likely lingering over the western CWA
into the afternoon.
Sunday - Sunday night:
The weather will become more interesting late Sunday afternoon into
the evening as an upper level closed low migrates into SD/NE. A
negatively tilted shortwave trough is progged to rotate from under
the upper low and lift northeast across KS and NE during the
afternoon. A moderately strong low level jet around 45kts will pull
deeper low level moisture ahead of a north-south dryline which will
anchor over central KS and far western OK. Expect to see scattered
strong/severe convection form along the dryline by mid/late
afternoon and track quickly northeast. Far northwest MO stands the
best chance of seeing active convection. Surface based CAPEs around
1500 J/kg and 0-6km shear around 40kts will support
strong/marginally severe storms over this area. All models strongly
suggest the dryline will move little to the east so the severe
threat in the CWA will likely be limited to far northwest MO.
Convection will weaken and decrease in coverage as it moves east
through the CWA with the far southeastern counties receiving the
least QPF.
Monday - Friday:
A fairly active period with two more closed upper lows likely
affecting the region. While Monday initially looked relatively quiet
as the Upper MS Valley system pulls away there is some concern that
some afternoon convection could form along the remnants of a stalled
surface boundary. The limiting factor will be increasing mid level
heights and a lack of upper support. Nonetheless with a front in the
CWA will need to be vigilant.
As we`ve been discussing over the past few days a second and
stronger upper system will become a factor and play a significant
role in our weather by Tuesday night and continuing into Wednesday.
Medium range operational models continue to eject a negatively
tilted shortwave through KS and MO. There is every reason to believe
a west-east frontal boundary will be in the vicinity with this
feature lifting north and through the CWA. Low-level moisture will
not be a problem with low/mid 60 dewpoints likely south of the front
and spreading northward. The GFS indicates 2000-3000 J/kg of CAPE
could be available with 30-40kt 0-6km shear so severe storms are a
growing concern. As always timing of the front and convective
development will determine where severe will occur but our CWA is
currently within the window of opportunity.
Convection could linger well into Wednesday as the upper low opens
up and lifts through NE/KS/IA/MO.
Thursday looks quiet as we`ll be between systems. The third system
we`ll be keeping an eye on will be yet another closed upper low.
This feature may not be a factor until late Friday.
Through out this period expect to see above average temperatures with
an overall increase in humidity.
&&
.Aviation...(For the 18Z TAFS through 18Z Sunday Afternoon)
Issued at 1230 PM CDT SAT APR 23 2016
VFR conds will prevail through the pd with mainly just sct high
clouds expected. Winds will pick up out of the south this afternoon
to 10-15kts with gusts to around 20kts. Winds will lose their gusts
this evening but still remain around 10-15kts. However, tomorrow
morning winds will again increase to 15-20kts with gusts to 25-30kts.
LLWS may be a marginal concern tonight as winds at 2kft will be out
of the SSW at 35-40kts btn 06Z-14Z and, may need to be added to the
TAF at the 00Z issuance.
&&
.EAX Watches/Warnings/Advisories...
KS...None.
MO...None.
&&
$$
Discussion...MJ
Aviation...73
Area Forecast Discussion
National Weather Service Springfield MO
1206 PM CDT SAT APR 23 2016
.SHORT TERM...(Today through Sunday)
Issued at 330 AM CDT Sat Apr 23 2016
An upper level ridge is currently building over the region early
this morning and will be centered over the area by tonight. As an
upper level trough tracks east into the northern Plains on Sunday
the ridge will start to spread off Sunday night.
Warm and dry conditions will occur through much of this weekend
as highs warm into the upper 70s to the lower 80s both afternoons.
Sunny skies will occur today with partly cloudy skies occurring on
Sunday. Gusty southerly winds will develop Sunday afternoon as
surface low pressure develops across the central Plains ahead of
the upper level low. Wind gusts over 30 mph can be expected for
locations generally along and west of Hwy 65 Sunday afternoon.
.LONG TERM...(Sunday night through Friday)
Issued at 330 AM CDT Sat Apr 23 2016
As the upper level low tracks east storms are expected to develop
to the west and northwest of the area along a cold front Sunday
evening. The front will then drop to the southeast into the area
Sunday night into Monday. The better lift and instability will
remain to the northwest and north of the area as the upper level
trough remains well north of the area. There will be an
instability gradient that sets up close to the far northwestern
portions of the area, so storms will be weakening as they move
southeast into the area, but a few strong storms may still be
possible generally northwest of a Pittsburg KS to Nevada MO line
Sunday night into early Monday morning. Coverage in storms will be
decreasing as the storms move into the area and will be isolated
to scattered in nature and many locations will remain dry. It is
also possible the storms dissipate just to the northwest of the
area.
As the front moves south through the area on Monday a few
thunderstorms will be possible, but overall most locations will
remain dry as coverage will be very limited with this activity.
Instability is expected to remain on the weak side, therefore,
not expecting a severe risk Monday.
Another upper level low will push into the northwestern U.S.
Sunday then dig to the south into the southwestern U.S. Monday
then lift to the northeast across the plains by Wednesday. As the
upper level low lifts to the northeast, the front that moves
south through the region Sunday night into Monday will lift back
to the north as a warm front Monday night into Tuesday morning.
Scattered storm chances will occur again along the front as it
lifts north.
Instability will then increase across the region on Tuesday ahead
of the approaching storm system, but a strong cap will also
develop across the area. The strong lift with this system will
remain well west of the area through the day on Tuesday, Therefore
most of the day should be dry after the warm front lifts north of
the area.
Storms are expected to develop across central Kansas
to the south into central Texas Tuesday evening along a cold
front. The front will then track east Tuesday night into Wednesday
Wednesday across the area. There is still some question on the
exact timing of the front but it will be at some point during the
day on Wednesday. There will be a severe risk with the storms
overnight Tuesday into Wednesday as the gulf moisture and an
unstable air mass will be in place across the area, large hail and
strong winds will be the main risk.
As the system moves off to the east mostly dry weather will occur
on Thursday. Then another system will begin to track into the
region Friday into the start of the weekend brining additional
chances for thunderstorms to the area.
&&
.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
Issued at 1159 AM CDT Sat Apr 23 2016
VFR conditions are expected through the period as surface high
pressure continues to drift eastward and an upper level ridge
moves across the area. Main forecast concern is gusty winds
beginning after sunrise on Sunday as the next approaching system
begins to tighten up the surface pressure gradient. Winds should
develop gusts after 13z at KSGF/KJLN but believe that it will be
later in the afternoon...after the end of the forecast
period...for KBBG.
&&
.SGF Watches/Warnings/Advisories...
MO...NONE.
KS...NONE.
&&
$$
SHORT TERM...Wise
LONG TERM...Wise
AVIATION...Gaede
Area Forecast Discussion
National Weather Service Springfield MO
1206 PM CDT SAT APR 23 2016
.SHORT TERM...(Today through Sunday)
Issued at 330 AM CDT Sat Apr 23 2016
An upper level ridge is currently building over the region early
this morning and will be centered over the area by tonight. As an
upper level trough tracks east into the northern Plains on Sunday
the ridge will start to spread off Sunday night.
Warm and dry conditions will occur through much of this weekend
as highs warm into the upper 70s to the lower 80s both afternoons.
Sunny skies will occur today with partly cloudy skies occurring on
Sunday. Gusty southerly winds will develop Sunday afternoon as
surface low pressure develops across the central Plains ahead of
the upper level low. Wind gusts over 30 mph can be expected for
locations generally along and west of Hwy 65 Sunday afternoon.
.LONG TERM...(Sunday night through Friday)
Issued at 330 AM CDT Sat Apr 23 2016
As the upper level low tracks east storms are expected to develop
to the west and northwest of the area along a cold front Sunday
evening. The front will then drop to the southeast into the area
Sunday night into Monday. The better lift and instability will
remain to the northwest and north of the area as the upper level
trough remains well north of the area. There will be an
instability gradient that sets up close to the far northwestern
portions of the area, so storms will be weakening as they move
southeast into the area, but a few strong storms may still be
possible generally northwest of a Pittsburg KS to Nevada MO line
Sunday night into early Monday morning. Coverage in storms will be
decreasing as the storms move into the area and will be isolated
to scattered in nature and many locations will remain dry. It is
also possible the storms dissipate just to the northwest of the
area.
As the front moves south through the area on Monday a few
thunderstorms will be possible, but overall most locations will
remain dry as coverage will be very limited with this activity.
Instability is expected to remain on the weak side, therefore,
not expecting a severe risk Monday.
Another upper level low will push into the northwestern U.S.
Sunday then dig to the south into the southwestern U.S. Monday
then lift to the northeast across the plains by Wednesday. As the
upper level low lifts to the northeast, the front that moves
south through the region Sunday night into Monday will lift back
to the north as a warm front Monday night into Tuesday morning.
Scattered storm chances will occur again along the front as it
lifts north.
Instability will then increase across the region on Tuesday ahead
of the approaching storm system, but a strong cap will also
develop across the area. The strong lift with this system will
remain well west of the area through the day on Tuesday, Therefore
most of the day should be dry after the warm front lifts north of
the area.
Storms are expected to develop across central Kansas
to the south into central Texas Tuesday evening along a cold
front. The front will then track east Tuesday night into Wednesday
Wednesday across the area. There is still some question on the
exact timing of the front but it will be at some point during the
day on Wednesday. There will be a severe risk with the storms
overnight Tuesday into Wednesday as the gulf moisture and an
unstable air mass will be in place across the area, large hail and
strong winds will be the main risk.
As the system moves off to the east mostly dry weather will occur
on Thursday. Then another system will begin to track into the
region Friday into the start of the weekend brining additional
chances for thunderstorms to the area.
&&
.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
Issued at 1159 AM CDT Sat Apr 23 2016
VFR conditions are expected through the period as surface high
pressure continues to drift eastward and an upper level ridge
moves across the area. Main forecast concern is gusty winds
beginning after sunrise on Sunday as the next approaching system
begins to tighten up the surface pressure gradient. Winds should
develop gusts after 13z at KSGF/KJLN but believe that it will be
later in the afternoon...after the end of the forecast
period...for KBBG.
&&
.SGF Watches/Warnings/Advisories...
MO...NONE.
KS...NONE.
&&
$$
SHORT TERM...Wise
LONG TERM...Wise
AVIATION...Gaede
Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
1140 AM CDT SAT APR 23 2016
.SHORT TERM... (Through Late This Afternoon)
Issued at 350 AM CDT Sat Apr 23 2016
Focus today will be clouds and temps.
Sfc ridge will continue to drift ewd today, allowing sly winds to
return to wrn portions of the CWA. Winds elsewhere are expected to
remain sely to ely.
The area of clouds currently just E of the CWA shud remain E.
However, some clouds may drift into ern portions of the CWA mainly
this morning until the ridge pushes them out of the area.
A secondary ridge axis over nrn portions of the CWA is expected to
be the focus for FG/stratus this morning. There is still uncertainty
regarding how widespread any FG will be, as well as any stratus. The
additional moisture within the bndy layer across this region shud
allow for at least sct clouds this morning, dissipating thru the
afternoon.
All of this leads to a rather complex temp forecast for today. For
ern portions of the CWA, have kept temps cooler where the ridge axis
will remain in place longer. Areas under this ridge yesterday saw
temps in the upper 60s, however, believe there will be less cloud
cover today. Believe the warmer temps will build into wrn portions
of the CWA where winds will become sly as well as the thermal ridge
building into this area. Have gone with trends close to a blend of
the RAP and local 4km WRF, which has been a good mix in these
setups. Did trend slightly cooler than this blend across nrn
portions of the CWA where more questions exist regarding cloud cover
today.
Tilly
.LONG TERM... (Tonight through Friday)
Issued at 350 AM CDT Sat Apr 23 2016
An upper level longwave RIDGE axis will persist over the Plains
thru much of next week, with upper longwave TROFs on the west and
east coasts. A series of strong Pacific storms will run thru this
RIDGE, being dropped off from the west coast TROF and being picked
up by the east coast TROF a few days later, with an overall track to
the E-NE thru our region. It would seem that each successive storm
system will track a bit further south than its predecessor.
The first storm system is slated to track to our north late Sunday
and into Monday, and will be mostly a glancing blow to our region as
a result, with what forms mostly upstream initially to our northwest
as it is thrown in our direction and largely weakens as it moves in.
This convection may also create additional boundaries during Monday
afternoon and early evening to maintain the threat for showers and
thunderstorms.
In the wake of this first storm system, a cold front will drop down
late Monday night into Tuesday and will maintain a low chance for
rain.
The second Pacific storm system will be more of a direct hit as it
will initially correspond well with the surface frontal boundary
buckling north as a warm front Wednesday morning. This should
result in elevated storms with hail as their primary threat during
that time.
Heading into Wednesday afternoon and evening, it will depend heavily
on how far north the front gets. Models have been trending with
less northward progress from 24hrs ago, but anywhere to the south of
it will have plenty of instability and moisture as well as strong
shear for more surface-based storms which will have a good potential
for some severe.
The rain potential lingers into Thursday if the cold front slows
enough to not make it thru until this day.
Friday should be a dry day, finally, but it appears only briefly
until yet another storm system approaches from the west in time for
the following weekend.
Otherwise, the longwave RIDGE setup will ensure that temps remain at
or above average throughout the period.
TES
&&
.AVIATION... (For the 18z TAFs through 18z Sunday Afternoon)
Issued at 1104 AM CDT Sat Apr 23 2016
Surface ridge extending from the Great Lakes region southwest
into eastern MO will shift eastward this period. The low level
cloudiness over eastern IA into northeast MO should remain north
of UIN this afternoon. The stratus cloudiness across southeast IL
should gradually dissipate this afternoon with daytime heating,
mixing and drying and remain east of the St Louis metro area.
There may be a few diurnal cumulus clouds at the taf sites this
afternoon. There will be a little high level cloudiness late
tonight and Sunday morning. Southeasterly surface winds should
strengthen at UIN and COU through the forecast period as the
surface pressure gradient gradually tightens, becoming more
southerly on Sunday. Light northeast wind in the St Louis metro
area will also strengthen as well through the period, veering
around to a southeast direction by early this evening, then
southerly Sunday morning. There will be some LLWS conditions in
UIN and COU very late tonight and early Sunday morning as a
southwesterly low level jet translates eastward into northwest MO
with both speed and directional shear in the lowest 1000 feet.
Specifics for KSTL: Stratus clouds across southeast IL should
gradually dissipate this afternoon and remain east-southeast of
STL. Few diurnal cumulus clouds may develop this afternoon due to
daytime heating, then dissipate early this evening. There will be
some high level cloudiness late tonight and Sunday. Light
northeast wind will increase in speed to 8-10 kts by late this
afternoon or early this evening as it veers around to a southeast
direction. The surface wind will become southerly Sunday morning
and possibly gusty Sunday afternoon.
GKS
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...None.
IL...None.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1237 PM CDT SAT APR 23 2016
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 320 AM CDT SAT APR 23 2016
THE PRIMARY FCST CONCERNS CONTINUE TO BE TSTM CHANCES FROM TONIGHT
INTO MONDAY AND TEMPS.
UPPER AIR CHARTS FROM LAST EVENING HAD THE FOLLOWING FEATURES OF
INTEREST. AT 850 MB...A RIDGE WAS IN PLACE FROM TX INTO MN. MOISTURE
AT THIS LEVEL WAS MAINLY CONFINED TO SOUTH TEXAS AND THE GULF
COASTAL REGION. A RIDGE WAS ALSO IN ABOUT THE SAME AREA AT 700 MB
...WITH A TROUGH TO THE WEST. AT 500 MB...A TROUGH WAS OVER THE
WRN UNITED STATES...WITH 12 HOUR HEIGHT FALLS OF UP TO 90 METERS
AT KOAK IN CA. A JET MAX OF AROUND 110 KTS WAS STILL OUT OVER THE
PACIFIC AT 300 MB...ON THE BACKSIDE OF THE TROUGH. LATEST WATER
VAPOR AND IR STLT IMAGERY SHOWED JUST SOME CIRRUS LOCALLY...WITH
AREAS OF FOG TO THE EAST IN IA AND THICKER MID LEVEL CLOUDS OVER
THE ROCKIES. AT THE SFC...A RIDGE WAS TO OUR EAST AND A TROUGH TO
THE WEST...FROM ERN MT INTO ERN CO. S OR SE WINDS WERE NOTED WITH
DEWPOINTS IN THE 40S. THE KOAX SOUNDING FROM LAST EVENING ONLY HAD
ABOUT 0.33 PW. THERE WAS SOME BETTER MOISTURE TO OUR S.
TODAY...WILL PROBABLY KEEP THE FCST DRY. THE 00Z NAM AND EVEN SOME
RECENT RAP MODEL RUNS TRIED TO DVLP ISOLD LGT PCPN OVER PARTS OF
THE AREA THIS MORNING. 06Z NAM AND MOST OF THE RECENT EXPERIMENTAL
HRRR RUNS DID NOT SHOW ANY PCPN. AS THE PRES GRADIENT TIGHTENS
TODAY...IT WILL BECOME BREEZY OR WINDY. PREVIOUS FCST HIGHS LOOKED
PRETTY GOOD...MAINLY 75 TO 80...SO CHANGES WERE MINOR.
PCPN CHANCES WILL BE INCREASING TONIGHT. GENLY FELT THAT MUCH OF
THE EVENING WOULD BE DRY...DESPITE SOME PCPN SHOWN BY THE GFS.
OTHER MODELS KEEP BEST PCPN CHANCES W OF OUR AREA UNTIL AFTER
MIDNIGHT. POPS MAINLY FROM 20-30 PCT SEEM PRUDENT BASED ON THE
MOISTURE RETURN AND FORCING. TREND SHOULD BE FOR PCPN TO TRY TO
DIE OUT SUN MORNING...THEN REDEVELOP IN THE AFTN. THERE IS FAIRLY
GOOD MODEL AGREEMENT ON THAT. SPC DAY 2 OTLK SHOWS SLGT CHANCE OF
SVR AND BASED ON INSTABILITY AND SHEAR FCSTS...THAT LOOKS RIGHT.
BOUNDARY LAYER CAPE VALUES UP TO ABOUT 1500 J/KG SEEM PSBL. THE
HIGHEST TSTM CHANCES WILL BE ACRS ABOUT THE SERN 1/2 OF THE FCST
AREA. LOOK FOR LOWS TNGT 55 TO 60 AND HIGHS SUN MOSTLY MID OR
UPPER 70S.
A FRONT WILL MOVE DOWN THROUGH THE AREA MON...BUT LIFT LOOKS WEAK
SO HAVE KEPT POPS BELOW 15 PCT FOR NOW.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 320 AM CDT SAT APR 23 2016
WEAK HIGH PRES SHOULD BE OVER THE AREA MON NGT...WITH CONTINUED
DRY WEATHER. BUT...A CLOSED LOW WILL BE ORGANIZING TO OUR W/SW
MOST LIKELY OVER UT OR NRN AZ. THAT SHOULD MOVE OUT TO WRN KS BY
12Z WED...THEN PROBABLY INTO IA BY 12Z THU. YET ANOTHER CLOSED LOW
IS EXPECTED TO BE OVER SRN CA BY THU MORNING. MODEL AGREEMENT IS
NOT OVERLY GREAT BY FRI...BUT THE GENERAL CONSENSUS IS THAT THE
LOW WILL PROBABLY OPEN UP AND MOVE OUT INTO THE HIGH PLAINS BY THE
WEEKEND.
THE 00Z GFS WAS SLOWER BRINGING A CHANCE OF SHRA/TSTMS BACK TO THE
AREA ON TUE COMPARED TO THE ECMWF. GAVE BOTH MODELS EQUAL WEIGHT
FOR NOW. PCPN SHOULD BE FAIRLY WIDESPREAD TUE NGT/WED...WHICH MAY
HELP LIMIT STRONG STORM COVERAGE. CURRENT EXPECTED TIMING DRIES
THE AREA OUT FOR THE PD FROM THU INTO FRI MORNING...THEN PCPN IS
LIKELY TO RETURN.
&&
.AVIATION...(18Z TAFS FOR KOMA...KLNK...KOFK THROUGH 18Z SUNDAY)
ISSUED AT 1230 PM CDT SAT APR 23 2016
VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THE PERIOD. STRONG
SOUTH WINDS WILL CONTINUE ACROSS THE AREA THROUGH ABOUT 06Z AS LOW
PRESSURE OVER HIGH PLAINS OF MONTANA AND WYOMING TRACKS EAST
ACROSS SOUTH DAKOTA. A FEW ISOLATED THUNDERSTORMS POSSIBLE AFTER
06Z AS COLD FRONT MOVES INTO CENTRAL NEBRASKA.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...MILLER
LONG TERM...MILLER
AVIATION...FOBERT
AREA FORECAST DISCUSSION
NWS BISMARCK ND
313 PM CDT SAT APR 23 2016
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 313 PM CDT SAT APR 23 2016
MAIN HIGHLIGHTS THROUGH SUNDAY AFTERNOON: RAINFALL AMOUNTS
ESPECIALLY LOCATIONS WHERE TOTALS EXCEED ONE INCH...A FEW STRONG
THUNDERSTORMS SOUTHWEST TONIGHT WITH POSSIBLE SMALL HAIL AND
GUSTY WINDS...AND POTENTIAL WIND ADVISORY TURTLE MOUNTAINS AND
VICINITY SUNDAY.
THE LATEST WATER VAPOR IMAGERY SHOWS A CLOSED UPPER LOW CIRCULATING
OVER FAR SOUTHEAST IDAHO WITH A DEEPENING SURFACE LOW
DOWNSTREAM...POSITIONED OVER NORTHEAST WYOMING. A WARM FRONT
EXTENDED FROM THIS LOW AND WAS DRAPED ALONG THE SOUTHERN BORDER.
WITH THIS WARM FRONT REMAINING JUST SOUTH OF OUR BORDER
TONIGHT/SUNDAY...AND THE UPPER LOW CATCHING UP WITH THE SURFACE
LOW AND BECOMING A VERTICALLY STACKED SYSTEM OVER CENTRAL SOUTH
DAKOTA...A WELL DEFINED DEFORMATION ZONE SETS UP OVER ALL OF
CENTRAL AND SOUTHERN NORTH DAKOTA LATER TONIGHT THROUGH SUNDAY.
FORCING/VERTICAL MOTION PER Q-VECTOR DIVERGENCE FIELD AND STEEP
MID LEVEL LAPSE RATES APPEAR MAXIMIZED BETWEEN INTERSTATE 94 AND
JUST SOUTH OF HIGHWAY 2. THIS SHOULD SET THE STAGE FOR PERIODS OF
HEAVIER RAINFALL AND HIGHEST RAINFALL TOTALS THROUGH SUNDAY.
EXPECT BETWEEN 1 AND 1.4 INCHES OF TOTAL RAINFALL THROUGH SUNDAY
NIGHT BETWEEN INTERSTATE 94 AND HIGHWAY 2.
THUNDERSTORM POTENTIAL REMAINS ELEVATED THROUGH THE PERIOD WITH
DECREASING CIN AS MOISTURE INCREASES THROUGH THE COLUMN AND
STEEPENING MID LEVEL LAPSE RATES. BEST CHANCES WILL BE TONIGHT
THROUGH SUNDAY MORNING...WITH SOUNDINGS BECOMING SATURATED AND
SHOWING RELATIVELY SKINNY OR NO CAPE FIELD. ENVIRONMENT SHOULD
TRANSITION MORE TOWARDS A HEAVY RAIN VERSUS CONVECTIVE IN NATURE.
SPC HAS MAINTAINED THE MARGINAL RISK FOR SEVERE THUNDERSTORMS IN
THE FAR SOUTHWEST TONIGHT. THINKING IS CONVECTION WOULD BEGIN AFTER
03Z PER LATEST HRRR AND GRADUALLY INCREASE OVERNIGHT INTO MID
MORNING SUNDAY.
GUSTY NORTHEAST WINDS WILL CONTINUE TONIGHT THROUGH SUNDAY ACROSS
ALL OF WESTERN AND CENTRAL NORTH DAKOTA. THE STRONGEST WINDS ARE
FORECAST ALONG AND NORTH OF HIGHWAY 2...WITH THE TURTLE MOUNTAINS
PINPOINTED FOR THE HIGHEST SUSTAINED WINDS OF AROUND 30 MPH AND
GUSTS TO 45 MPH. FUTURE SHIFTS CAN RE-EVALUATE FOR A POSSIBLE WIND
ADVISORY.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 313 PM CDT SAT APR 23 2016
THE VERTICALLY STACKED SYSTEM CONTINUES TO SLOWLY SHIFT EAST
SUNDAY NIGHT AND MONDAY WITH A GRADUAL DECREASE IN POPS. HOWEVER
THE ECMWF HAS BEEN CONSISTENTLY ADVERTISING HIGHER QPF AND COLDER
AIR ESPECIALLY ALONG AND SOUTH OF INTERSTATE 94 MONDAY. THUS HAVE
TRENDED POPS BETWEEN CHC/LIKELY WITH MOSTLY RAIN AND A LITTLE BIT
OF SNOW EXPECTED. SNOWFALL ACCUMULATIONS OF A COUPLE TENTHS POSSIBLE
SUNDAY NIGHT ACROSS THE WEST.
ANOTHER ROUND OF PRECIPITATION IS POSSIBLE TUESDAY NIGHT THROUGH
WEDNESDAY NIGHT MAINLY ACROSS SOUTHERN NORTH DAKOTA. THE GFS AND
ECMWF CONTINUE TO BE AT ODDS IF THIS WILL OCCUR. THE GFS HAS BEEN
CONSISTENTLY SHOWING THE ABOVE...WHILE THE ECMWF IS NOT AS FAR
NORTH WITH THE PRECIPITATION SHIELD.
A BREAK IN THE PRECIPITATION THREAT IS POSSIBLE THURSDAY AND FRIDAY.
ANOTHER WET PERIOD SATURDAY BUT THE GFS AND ECMWF DIFFER ON PLACEMENT
OF THE PRECIPITATION AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 313 PM CDT SAT APR 23 2016
VFR CONDITIONS WILL PREVAIL THIS AFTERNOON AND EVENING WITH A FEW
SHOWERS AND ISOLATED STORMS POSSIBLE. BREEZY EAST-NORTHEAST WINDS
WILL STEADILY INCREASE WITH 25 TO 35 KT GUSTS WIDESPREAD TONIGHT
AND SUNDAY. EXPECT CEILINGS TO LOWER TONIGHT WITH WIDESPREAD MVFR
AND IFR CONDITIONS ACROSS WESTERN AND CENTRAL ND LATE TONIGHT AND
SUNDAY TO GO WITH AN INCREASE IN RAIN AND THUNDERSTORM CHANCES.
THAT SAID...WE HAVE ONLY MODEST CONFIDENCE IN TIMING THE ONSET OF
LOWER CEILINGS AND PRECIPITATION AT ANY SPECIFIC TERMINAL.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KS
LONG TERM...KS
AVIATION...CJS
AREA FORECAST DISCUSSION...CORRECTED
NWS LUBBOCK TX
349 PM CDT SAT APR 23 2016
.SHORT TERM...
THE DRYLINE HAS BEEN SITTING IN EASTERN NM FOR SOME TIME TODAY AND
SHOULD STAY THERE...FOR THE MOST PART... UNTIL THE UPPER LEVEL LOW
PUSHES CLOSER TO THE REGION. CONVECTION ALONG THE DRYLINE STILL
LOOKS UNLIKELY AS LIFT LOOKS TO BE HARD TO COME BY. THE BEST CHANCE
FOR LIFT WOULD BE WITH THE DRYLINE. THE BEST SURFACE CONVERGENCE
ALONG THE DRYLINE IS NORTH IN THE TEXAS PANHANDLE. A LOCALIZED AREA
OF ENHANCE CONVERGENCE HAS RECENTLY SET UP OVER THE TX/NM STATE LINE
AROUND PARMER COUNTY. THIS HAS RESULTED IN A SHALLOW CU FIELD.
ENOUGH LIFT FOR ISOLATED SHOWER DEVELOPMENT IS NOT OUT OF THE
QUESTION...HOWEVER THUNDERSTORM DEVELOPMENT IS NOT HIGH ON THE
EXPECTATION LIST. THIS IS DUE TO CONVECTION HAVING TO OVERCOME A
SUBSIDENCE INVERSION IN THE UPPER-MID LEVELS AS WELL AS THERE BEING
A LACK OF CAPE. THE HRRR SEEMS TO BE THE MOST GENEROUS OF THE MODELS
IN HANDING OUT CAPE WHICH IS ONLY A COUPLE HUNDRED J/KG AT BEST
ACROSS OUR NORTHWESTERN ZONES. FOR NOW THE FORECAST WILL REFLECT A
MENTION OF ISOLATED SHOWERS BEFORE 1 AM AND NO MENTION OF THUNDER.
WINDS WILL STAY GUSTY INTO THE NIGHT AHEAD OF AND BEHIND THE
DRYLINE. WINDS WILL BE MOSTLY OUT OF THE WEST BY EARLY TOMORROW
AFTERNOON ACROSS THE CAPROCK AND WILL INCREASE TO THE 25 MPH RANGE
AS THE MAIN ENERGY FROM THE UPPER LOW PASSES TO OUR NORTH. ALDRICH
.LONG TERM...
WARM...DRY AND BREEZY CONDITIONS ARE IN STORE THROUGH TUESDAY.
THE SECOND IN A SERIES OF UPPER LOWS/TROUGHS WILL SWING ACROSS THE
SOUTHERN HIGH PLAINS TUESDAY AFTERNOON...PRODUCING THE WINDIEST
DAY OF THE PERIOD. GFS MOS GUIDANCE CONTINUES TO HOVER AROUND 30
TO 34 KTS AT LUBBOCK...WHILE THE MET IS AROUND 20 KTS. WE
CONTINUE TO PLY THE MIDDLE-GROUND AT AROUND 25 KTS OR SO...OR 25
TO 30 MPH WITH GUSTS TO AROUND 40 MPH. HIGH TEMPS MONDAY AND
TUESDAY SHOULD BE IN THE 80S TO LOW 90S. WE HAVE RETAINED A SLIVER
OF T-STORM CHANCES IN THE SRN ROLLING PLAINS LATE THURSDAY...BUT
THE LATEST INDICATIONS ARE THAT THE DRYLINE WILL BE TO THE EAST OF
THE AREA...BUT IT IS NOT OUT OF THE QUESTION SOME STORMS COULD
DEVELOP IN THAT AREA AS THE DRYLINE RETREATS SOMEWHAT IN THE
EVENING. WEDNESDAY SHOULD BE SLIGHTLY COOLER AS FLOW SWITCHES TO
NORTHWEST...THEN A COLD FRONT WILL MOVE THROUGH WEDNESDAY NIGHT OR
EARLY THURSDAY. THE NEXT UPPER LOW IS STILL FORECAST TO DIG INTO
THE DESERT SOUTHEAST MIDWEEK WITH NOT MUCH CHANGE IN TRACK THE
PAST 24 HRS. SURFACE RIDGING...A STRENGTHENING SRLY LOW-LEVEL JET
AND SW FLOW ALOFT THURSDAY SHOULD RETURN GULF MOISTURE INTO THE
AREA AND ALONG WITH SOME ISENTROPIC UPGLIDE...BEGIN TO INCREASE
PRECIP CHANCES. DURING THE DAY THURSDAY THESE CHANCES MAY BE
CONFINED TO OUR SRN AND ERN COUNTIES WHERE THE DEEPER MOISTURE IS
EXPECTED TO BE NOSING IN FROM THE SOUTH. THURSDAY NIGHT INTO
FRIDAY MORNING WE COULD SEE SHOWER AND T-STORM ACTIVITY INCREASE
AS LARGE-SCALE ASCENT FROM THE UPPER LOW BEGINS TO SPREAD OVER THE
REGION. BY FRIDAY...THE MED- RANGE SOLUTIONS BEGIN TO DIVERGE WITH
THE SURFACE DETAILS AS THE GFS BRINGS A DRYLINE INTO THE AREA
WHILE THE ECMWF MAINTAINS SURFACE RIDGING. OVERALL...THE PATTERN
CERTAINLY APPEARS FAVORABLE FOR T-STORM ACTIVITY...AND POSSIBLY
SEVERE WEATHER...BUT AS USUAL THE CONFIDENCE IN THE DETAILS IS LOW
THIS FAR OUT. THE UPPER- TROUGH IS CURRENTLY EXPECTED TO PASS
ACROSS WEST TEXAS DURING THE DAY SATURDAY...DRAGGING PRECIP.
CHANCES EASTWARD WITH IT.
&&
.FIRE WEATHER...
THE FIRE DANGER WILL BECOME ELEVATED ACROSS MUCH OF THE CAPROCK
EACH AFTERNOON SUNDAY THROUGH TUESDAY. CONDITIONS WILL LIKELY BE
THE WORST ON TUESDAY AS A PASSING STORM SYSTEM BRINGS STRONGER
WIND SPEEDS. HOWEVER...THE OVERALL FIRE DANGER WILL BE REDUCED BY
THE SEASONAL GREEN-UP ACROSS THE AREA.
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
51/33
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
341 PM CDT SAT APR 23 2016
.SHORT TERM...
THE DRYLINE HAS BEEN SITTING IN EASTERN NM FOR SOME TIME TODAY AND
SHOULD STAY THERE...FOR THE MOST PART... UNTIL THE UPPER LEVEL LOW
PUSHES CLOSER TO THE REGION. CONVECTION ALONG THE DRYLINE STILL
LOOKS UNLIKELY AS LIFT LOOKS TO BE HARD TO COME BY. THE BEST CHANCE
FOR LIFT WOULD BE WITH THE DRYLINE. THE BEST SURFACE CONVERGENCE
ALONG THE DRYLINE IS NORTH IN THE TEXAS PANHANDLE. A LOCALIZED AREA
OF ENHANCE CONVERGENCE HAS RECENTLY SET UP OVER THE TX/NM STATE LINE
AROUND PARMER COUNTY. THIS HAS RESULTED IN A SHALLOW CU FIELD.
ENOUGH LIFT FOR ISOLATED SHOWER DEVELOPMENT IS NOT OUT OF THE
QUESTION...HOWEVER THUNDERSTORM DEVELOPMENT IS NOT HIGH ON THE
EXPECTATION LIST. THIS IS DUE TO CONVECTION HAVING TO OVERCOME A
SUBSIDENCE INVERSION IN THE UPPER-MID LEVELS AS WELL AS THERE BEING
A LACK OF CAPE. THE HRRR SEEMS TO BE THE MOST GENEROUS OF THE MODELS
IN HANDING OUT CAPE WHICH IS ONLY A COUPLE HUNDRED J/KG AT BEST
ACROSS OUR NORTHWESTERN ZONES. FOR NOW THE FORECAST WILL REFLECT A
MENTION OF ISOLATED SHOWERS BEFORE 1 AM AND NO MENTION OF THUNDER.
WINDS WILL STAY GUSTY INTO THE NIGHT AHEAD OF AND BEHIND THE
DRYLINE. WINDS WILL BE MOSTLY OUT OF THE WEST BY EARLY TOMORROW
AFTERNOON ACROSS THE CAPROCK AND WILL INCREASE TO THE 25 MPH RANGE
AS THE MAIN ENERGY FROM THE UPPER LOW PASSES TO OUR NORTH. ALDRICH
.LONG TERM...
WARM...DRY AND BREEZY CONDITIONS ARE IN STORE THROUGH TUESDAY.
THE SECOND IN A SERIES OF UPPER LOWS/TROUGHS WILL SWING ACROSS THE
SOUTHERN HIGH PLAINS TUESDAY AFTERNOON...PRODUCING THE WINDIEST
DAY OF THE PERIOD. GFS MOS GUIDANCE CONTINUES TO HOVER AROUND 30
TO 34 KTS AT LUBBOCK...WHILE THE MET IS AROUND 20 KTS. WE
CONTINUE TO PLY THE MIDDLE-GROUND AT AROUND 25 KTS OR SO...OR 25
TO 30 MPH WITH GUSTS TO AROUND 40 MPH. HIGH TEMPS MONDAY AND
TUESDAY SHOULD BE IN THE 80S TO LOW 90S. WEDNESDAY SHOULD BE
SLIGHTLY COOLER AS FLOW SWITCHES TO NORTHWEST...THEN A COLD FRONT
WILL MOVE THROUGH WEDNESDAY NIGHT OR EARLY THURSDAY. THE NEXT
UPPER LOW IS STILL FORECAST TO DIG INTO THE DESERT SOUTHEAST
MIDWEEK WITH NOT MUCH CHANGE IN TRACK THE PAST 24 HRS. SURFACE
RIDGING...A STRENGTHENING SRLY LOW-LEVEL JET AND SW FLOW ALOFT
THURSDAY SHOULD RETURN GULF MOISTURE INTO THE AREA AND ALONG WITH
SOME ISENTROPIC UPGLIDE...BEGIN TO INCREASE PRECIP CHANCES. DURING
THE DAY THURSDAY THESE CHANCES MAY BE CONFINED TO OUR SRN AND ERN
COUNTIES WHERE THE DEEPER MOISTURE IS EXPECTED TO BE NOSING IN
FROM THE SOUTH. THURSDAY NIGHT INTO FRIDAY MORNING WE COULD SEE
SHOWER AND T-STORM ACTIVITY INCREASE AS LARGE-SCALE ASCENT FROM
THE UPPER LOW BEGINS TO SPREAD OVER THE REGION. BY FRIDAY...THE MED-
RANGE SOLUTIONS BEGIN TO DIVERGE WITH THE SURFACE DETAILS AS THE
GFS BRINGS A DRYLINE INTO THE AREA WHILE THE ECMWF MAINTAINS
SURFACE RIDGING. OVERALL...THE PATTERN CERTAINLY APPEARS FAVORABLE
FOR T-STORM ACTIVITY...AND POSSIBLY SEVERE WEATHER...BUT AS USUAL
THE CONFIDENCE IN THE DETAILS IS LOW THIS FAR OUT. THE UPPER-
TROUGH IS CURRENTLY EXPECTED TO PASS ACROSS WEST TEXAS DURING THE
DAY SATURDAY...DRAGGING PRECIP. CHANCES EASTWARD WITH IT.
&&
.FIRE WEATHER...
THE FIRE DANGER WILL BECOME ELEVATED ACROSS MUCH OF THE CAPROCK
EACH AFTERNOON SUNDAY THROUGH TUESDAY. CONDITIONS WILL LIKELY BE
THE WORST ON TUESDAY AS A PASSING STORM SYSTEM BRINGS STRONGER
WIND SPEEDS. HOWEVER...THE OVERALL FIRE DANGER WILL BE REDUCED BY
THE SEASONAL GREEN-UP ACROSS THE AREA.
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
51/33