Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 03/15/16
AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
830 PM PDT MON MAR 14 2016
.SYNOPSIS...
GUSTY NORTH WINDS WILL CONTINUE FOR PARTS OF THE AREA THROUGH
TUESDAY MORNING. A WARMING TREND IS EXPECTED THROUGH MID WEEK AS
HIGH PRESSURE BUILDS ALOFT AND OFFSHORE FLOW DEVELOPS. SLIGHT
COOLING IS EXPECTED FOR THE END OF THE WEEK AND THE WEEKEND AS A
WEAK TROUGH APPROACHES...BUT TEMPERATURES WILL GENERALLY REMAIN
ABOVE NORMAL INTO EARLY NEXT WEEK.
&&
.SHORT TERM...(TONIGHT-THU)
OVERALL...FORECAST IS LOOKING GOOD IN THE IMMEDIATE SHORT TERM.
MAIN ISSUE THIS EVENING AND OVERNIGHT IS THE WINDS. CURRENTLY
SOLID ADVISORY LEVEL WEST/NORTHWEST WINDS ARE CONTINUING ACROSS
THE ANTELOPE VALLEY...AND NORTHWEST/NORTH WINDS ARE BEGINNING TO
INCREASE ACROSS THE SANTA YNEZ RANGE AS WELL AS THE INTERSTATE 5
CORRIDOR. SO...CURRENT WIND ADVISORIES LOOK GOOD THROUGH
TONIGHT/TUESDAY MORNING...AND WILL REMAIN IN EFFECT. OTHERWISE
SATELLITE SHOWS SOME LINGERING STRATOCU OVER INTERIOR SECTIONS
WITH SOME HIGH CLOUDS STREAMING OVERHEAD. GENERIC PARTLY CLOUDY
WORDING SHOULD COVER THINGS THROUGH TONIGHT...WITH AN OUTSIDE
CHANCE OF SOME STRATUS/FOG DEVELOPING ACROSS THE SALINAS VALLEY
AND OVER THE LAX COASTAL PLAIN.
QUICK LOOK AT INITIAL 00Z MODEL DATA INDICATES NO SURPRISES OR
SIGNIFICANT CHANGES TO CURRENT FORECAST. AT UPPER LEVELS...RIDGE
WILL AMPLIFY OVER THE EASTERN PACIFIC TUESDAY/WEDNESDAY BEFORE
WEAKENING SLIGHTLY ON THURSDAY. NEAR THE SURFACE...WEAK OFFSHORE
GRADIENTS WILL PREVAIL THROUGH WEDNESDAY THEN WILL SHIFT WEAKLY
ONSHORE ON THURSDAY. SO...SKIES SHOULD REMAIN MOSTLY CLEAR TUESDAY
THROUGH THURSDAY. AS FOR TEMPERATURES...EXPECT A NICE WARMING
TREND ON TUESDAY AND WEDNESDAY THEN POSSIBLY SOME VERY SLIGHT
COOLING ON THURSDAY. AS FOR WINDS...THERE WILL BE SOME LOCALLY
BREEZY OFFSHORE WINDS TUESDAY AND WEDNESDAY...BUT WITH LIMITED
UPPER SUPPORT...THE WINDS SHOULD REMAIN BELOW ADVISORY LEVELS.
.LONG TERM...(FRI-MON)
THE UPPER RIDGE WILL WEAKEN SOMEWHAT FRI THROUGH SUN...BUT
WARM AND DRY CONDITIONS WILL PERSIST WITH TEMPERATURES STILL WELL
ABOVE NORMAL. SOME UPPER LEVEL MOISTURE STREAMING ACROSS THE AREA
MAY BRING HIGH CLOUDS TO SOUTHWEST CALIFORNIA...AS DISTURBANCES
PASS THROUGH NORTHERN CALIFORNIA. OTHERWISE QUIET WEATHER IS
EXPECTED THROUGH THE WEEKEND.
&&
.AVIATION...14/2300Z...
AT 2250Z...THERE WAS NO MARINE INVERSION AT KLAX.
OVERALL...MODERATE TO HIGH CONFIDENCE IN 00Z TAF PACKAGE. WITH
WEAK TO MODERATE NORTHWEST FLOW EXPECTED TONIGHT, ALL SITES ARE
FORECAST TO REMAIN VFR THROUGH THE PERIOD. HOWEVER, THERE WILL BE
A 20-30% CHANCE OF SOME MVFR/IFR FLIGHT RESTRICTIONS AT KPRB AS
WELL AS KLAX AND KLGB. ADDITIONALLY, THERE WILL BE SOME LLWS AND
LIGHT TURBULENCE AT KSBA TONIGHT AS WELL AS THROUGH THE LOCAL
MOUNTAIN PASSES.
KLAX...MODERATE CONFIDENCE IN 00Z TAF AS VFR CO0NDS ARE FORECAST
TO PREVAIL THROUGH THE PERIOD. THERE IS A 20% CHANCE OF MVFR/IFR
FLIGHT RESTRICTIONS DEVELOPING 10Z-18Z.
KBUR...HIGH CONFIDENCE IN 00Z TAF AS VFR CONDS ARE EXPECTED
THROUGH THE TAF PERIOD.
&&
.MARINE...14/830 PM...
FOR THE OUTER WATERS, MODERATE TO HIGH CONFIDENCE IN CURRENT
FORECAST. HIGH CONFIDENCE IN SMALL CRAFT ADVISORY-LEVEL NORTHWEST
WINDS CONTINUING THROUGH TUESDAY NIGHT/WEDNESDAY MORNING. FOR
WEDNESDAY AFTERNOON THROUGH SATURDAY, NORTHWEST WINDS WILL BE A
BIT WEAKER WITH A CHANCE OF SMALL CRAFT ADVISORY LEVEL WINDS
DEVELOPING. SEAS WILL REMAIN ABOVE 10 FEET THROUGH WEDNESDAY
MORNING.
FOR THE INNER WATERS, MODERATE TO HIGH CONFIDENCE IN CURRENT
FORECAST. FOR THE WATERS NORTH OF POINT SAL, MODERATE CONFIDENCE
IN NORTHWEST WINDS REMAINING BELOW SMALL CRAFT ADVISORY LEVELS
THROUGH SATURDAY (ALTHOUGH THERE IS A 30% CHANCE OF WINDS REACHING
ADVISORY LEVELS TUESDAY AFTERNOON/EVENING). AS FOR SEAS, EXPECT
HAZARDOUS SEAS CONDITIONS (10+ FOOT SEAS) TO CONTINUE THROUGH
TUESDAY NIGHT. FOR THE WATERS SOUTH OF POINT CONCEPTION, BOTH
WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY
LEVELS THROUGH SATURDAY (ALTHOUGH THERE IS A 30% CHANCE OF GUSTS
REACHING ADVISORY LEVELS TUESDAY AFTERNOON/EVENING ACROSS WESTERN
SECTIONS OF THE SOUTHERN INNER WATERS).
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
CA...HIGH SURF ADVISORY IN EFFECT UNTIL MIDNIGHT PDT TUESDAY NIGHT
FOR ZONES 34-35. (SEE LAXCFWLOX).
WIND ADVISORY IN EFFECT UNTIL 9 AM PDT TUESDAY FOR ZONES
39-52>54. (SEE LAXNPWLOX).
WIND ADVISORY IN EFFECT UNTIL 3 AM PDT TUESDAY FOR ZONE 59. (SEE LAXNPWLOX).
PZ...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS IN EFFECT UNTIL 3 PM
PDT TUESDAY FOR ZONE 645. (SEE LAXMWWLOX).
SMALL CRAFT ADVISORY IN EFFECT UNTIL 11 AM PDT WEDNESDAY FOR
ZONES 670-673-676. (SEE LAXMWWLOX).
&&
$$
PUBLIC...JLD/RAT
AVIATION...RAT
MARINE...RAT
SYNOPSIS...SUKUP
WEATHER.GOV/LOSANGELES
[top]
Area Forecast Discussion
National Weather Service Reno NV
756 PM PDT MON MAR 14 2016
.UPDATE...
Winds continue to diminish over the region as the pressure
gradient relaxes. The Lake Wind Advisories for Lake Tahoe and
Pyramid Lake have been allowed to expire. Conditions on Lake Tahoe
will remain a little choppy until after midnight when the winds
drop further.
&&
.PREVIOUS DISCUSSION... /Issued 238 PM PDT MON MAR 14 2016/
SYNOPSIS...
Strong gusty winds continued this afternoon but are expected to
subside tonight as high pressure moves into the region. Gradual
warming is expected this week with temperatures well above normal by
weeks end. Gusty winds may return next weekend with potential for
light precipitation in the northern Sierra early next week.
SHORT TERM...
Strong gusty winds continued across the region today associated with
cold front nearby and enhanced pressure gradient. Some areas in
Mono/Mineral Counties hit what would normally be Red Flag criteria
with humidities below 10% and gusts 40-60 mph. This included the
Mammoth Airport for several hours. Winds will drop off rather
quickly tonight as gradient relaxes with incoming high pressure.
That shows up well in the HRRR guidance. Could still see a few light
rain/snow showers early this evening in far NE Cal and NW Nev but no
accumulations.
Tuesday looks to be a transition day, with gusty W/NW winds likely
north of a Susanville-Fallon line with the retreating front still in
the vicinity. Building high pressure just off the west coast will
yield warming temperatures aloft over the region and a weak NE low
level flow Wednesday-Thursday. Warming in valleys will be gradual as
a result but strong inversions are not anticipated. Overall looks to
be a prime week to get outdoor projects or yard work done. -Chris
LONG TERM...Friday through Monday...
Forecast models continue to show the ridge axis shifting across the
Sierra and western Nevada on Friday and Saturday. Dry conditions
expected through the end of the week along with light northeast,
east winds for the Sierra and western Nevada. Temperatures will
climb into the upper 60s and near 70 degrees by Saturday as the
ridge axis shifts eastward and allows light west winds to return.
There is potential for the ridge to break down by late Saturday into
Sunday which will allow the large scale pattern to become a bit more
active again. Both operational models are targeting an upper level
jet along with some moisture towards the west coast. There is some
uncertainty where the jet will land, anywhere from the Lake Tahoe
Basin up towards the Pacific Northwest. There is some potential for
valley rain and mountain snow showers for late Sunday into Monday.
Edan
AVIATION...
The strong wind gusts around 60-80 kts across the Sierra ridges from
this morning will continue to diminish through the afternoon and
evening. Terminals in the eastern Sierra and western Nevada should
expect wind gusts decreasing to around 15-25 kts by this evening.
Only terminal that may still see wind gusts later in the evening
would be KMMH.
VFR conditions are expected to prevail across the area by this
afternoon and evening. Conditions have dried out considerably, so we
don`t anticipate fog forming in the Sierra valleys. Edan
&&
.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 LOS ANGELES/OXNARD CA
350 PM PDT MON MAR 14 2016
...UPDATED AVIATION DISCUSSION...
.SYNOPSIS...
BUILDING HIGH PRESSURE ALOFT AND OFFSHORE FLOW WILL BRING
SIGNIFICANT WARMING TO THE AREA TUESDAY AND WEDNESDAY...WITH
LOCALLY GUSTY WINDS AT TIMES. DRY WEATHER WITH WELL ABOVE NORMAL
TEMPERATURES WILL CONTINUE THROUGH THE WEEKEND...ALTHOUGH THERE
MAY BE A FEW DEGREES OF COOLING BY SUNDAY.
&&
.SHORT TERM...(TDY-THU)
MOST AREAS HAVE CLEARED TO PARTLY CLOUDY THIS AFTERNOON...WITH
THE EXCEPTION OF SOME FOOTHILL AND MOUNTAIN LOCATIONS. EXPECT
BETTER CLEARING TONIGHT UNDER INCREASING NORTHERLY FLOW...EXCEPT
FOR THE COASTAL REGION OF L.A. COUNTY NEAR LONG BEACH...WHERE LOW
CLOUDS AND PATCHY FOG MAY MAKE AN APPEARANCE.
NORTHWEST WINDS ARE INCREASING ACROSS THE AREA AS A NORTHERLY
PRESSURE GRADIENT DEVELOPS. ADVISORY-LEVEL GUSTS ARE EXPECTED
ACROSS SOUTHERN SANTA BARBARA COUNTY...AND THE INTERIOR MOUNTAINS
OF L.A. AND VENTURA COUNTIES ON THE GRAPEVINE. ANTELOPE VALLEY
WILL SEE WESTERLY GUSTS UP TO 50 MPH THROUGH EARLY TUESDAY
MORNING. ADVISORIES HAVE BEEN ISSUED FOR THE ABOVE-MENTIONED
AREAS. SUB-ADVISORY NORTHERLY GUSTS WILL SPREAD OVER THE SANTA
CLARITA VALLEY...PORTIONS OF THE SAN FERNANDO VALLEY...THE ERN
VLYS OF VTU COUNTY...THE SANTA MONICA MTNS...AND COASTAL SECTIONS
OF L.A. COUNTY BELOW PASSES AND CANYONS FROM MALIBU TO THE
HOLLYWOOD HILLS.
OTHERWISE...HEIGHTS ARE FORECAST TO RISE ACROSS THE REGION ON
TUESDAY AS AN UPPER RIDGE AMPLIFIES IN THE EASTERN PACIFIC. THE
RIDGE WILL GRADUALLY MOVE EASTWARD THROUGH THURSDAY...AND FLOW
ALOFT WILL SHIFT TO THE NORTH TO NORTHEAST. A WARMING TREND IS
FORECAST THROUGH WEDNESDAY...WITH HIGHS RISING 5 TO 7 DEGREES
EACH DAY. THE UPPER HIGH WILL BE JUST WEST OF THE COASTLINE BY
THURSDAY. WEAK ONSHORE GRADIENTS THURSDAY AFTERNOON MAY PROVIDE A
SLIGHT DEGREE OF COOLING COMPARED TO WEDNESDAY.
.LONG TERM...(FRI-MON)
THE UPPER RIDGE WILL WEAKEN SOMEWHAT FRI THROUGH SUN...BUT
WARM AND DRY CONDITIONS WILL PERSIST WITH TEMPERATURES STILL WELL
ABOVE NORMAL. SOME UPPER LEVEL MOISTURE STREAMING ACROSS THE AREA
MAY BRING HIGH CLOUDS TO SOUTHWEST CALIFORNIA...AS DISTURBANCES
PASS THROUGH NORTHERN CALIFORNIA. OTHERWISE QUIET WEATHER IS
EXPECTED THROUGH THE WEEKEND.
&&
.AVIATION...14/2250Z...
AT 2250Z...THERE WAS NO MARINE INVERSION AT KLAX.
OVERALL...MODERATE TO HIGH CONFIDENCE IN 00Z TAF PACKAGE. WITH WEAK
TO MODERATE NORTHWEST FLOW EXPECTED TONIGHT, ALL SITES ARE FORECAST
TO REMAIN VFR THROUGH THE PERIOD. HOWEVER, THERE WILL BE A 20-30%
CHANCE OF SOME MVFR/IFR FLIGHT RESTRICTIONS AT KPRB AS WELL AS KLAX
AND KLGB. ADDITIONALLY, THERE WILL BE SOME LLWS AND LIGHT TURBULENCE
AT KSBA TONIGHT AS WELL AS THROUGH THE LOCAL MOUNTAIN PASSES.
KLAX...MODERATE CONFIDENCE IN 00Z TAF AS VFR CO0NDS ARE FORECAST TO
PREVAIL THROUGH THE PERIOD. THERE IS A 20% CHANCE OF MVFR/IFR FLIGHT
RESTRICTIONS DEVELOPING 10Z-18Z.
KBUR...HIGH CONFIDENCE IN 00Z TAF AS VFR CONDS ARE EXPECTED THROUGH
THE TAF PERIOD.
&&
.MARINE...14/200 PM
SMALL CRAFT ADVISORY CONDITIONS THROUGH WEDNESDAY MORNING DUE TO
HAZARDOUS SEAS OR NORTHWESTERLY WINDS. FORTY PERCENT CHANCE OF
SMALL CRAFT CONDITIONS THIS AFTERNOON AND EVENING IN THE WESTERN
THIRD OF THE SANTA BARBARA CHANNEL.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
CA...HIGH SURF ADVISORY IN EFFECT UNTIL MIDNIGHT PDT TUESDAY NIGHT
FOR ZONES 34-35. (SEE LAXCFWLOX).
BEACH HAZARDS STATEMENT IN EFFECT UNTIL 5 PM PDT THIS
AFTERNOON FOR ZONE 39. (SEE LAXCFWLOX).
WIND ADVISORY IN EFFECT FROM 6 PM THIS EVENING TO 9 AM PDT
TUESDAY FOR ZONES 39-52>54. (SEE LAXNPWLOX).
HIGH SURF ADVISORY IN EFFECT UNTIL 5 PM PDT THIS AFTERNOON
FOR ZONES 40-41-87. (SEE LAXCFWLOX).
WIND ADVISORY IN EFFECT UNTIL 3 AM PDT TUESDAY FOR ZONE 59. (SEE LAXNPWLOX).
PZ...SMALL CRAFT ADVISORY IN EFFECT UNTIL 11 AM PDT WEDNESDAY FOR
ZONES 645-670-673-676. (SEE LAXMWWLOX).
&&
$$
PUBLIC...JLD/CS
AVIATION...RAT
MARINE...KJ
SYNOPSIS...SWEET
WEATHER.GOV/LOSANGELES
[top]
Area Forecast Discussion
National Weather Service Sacramento CA
319 PM PDT MON MAR 14 2016
.SYNOPSIS...
Confidence still high in a drier and warmer week. Maybe a system
moving into late in the weekend and/or early next week.
&&
.SHORT TERM DISCUSSION...
Fast mid level flow will bring some gusty winds to highest
elevations tonight...otherwise the weather will be mild and dry
tonight.
Tomorrow through Friday...a ridge of high pressure slowly builds
into the area. This will result in warming temperatures each day
this week and a dry period. Rasch
&&
.EXTENDED DISCUSSION (Friday THROUGH Monday)
High temperatures will be above normal on Friday but may be a
little cooler than Thursday, as upper level ridging begins to
shift eastward. Temperatures gradually trend downward over the
weekend as a trough approaches and the ridge moves further east.
This will bring a slight chance of showers to the Coastal and
Shasta mountains Saturday afternoon, spreading to higher terrain
of W Plumas County and Sierra Nevada, and into the Northern
Sacramento Valley Saturday night. Precipitation could spread to
I80 by Sunday afternoon, and potentially further south for Sunday
night and Monday. While not a strong storm, recent model runs
have trended wetter and farther south with this system. High
temperatures drop to near normal levels early next week with
increased cloud cover. EK
&&
.AVIATION...
Mainly VFR conditions the next 24 hours, except patchy MVFR/IFR
fog may develop along the Sacramento Valley south of KMYV early
Tuesday morning. SW to NW winds 5-15 kt will become light tonight,
then become NW 5-15 kt Tuesday.
Dang
&&
.STO Watches/Warnings/Advisories...
None.
&&
$$
Area Forecast Discussion
National Weather Service Reno NV
238 PM PDT MON MAR 14 2016
.SYNOPSIS...
Strong gusty winds continued this afternoon but are expected to
subside tonight as high pressure moves into the region. Gradual
warming is expected this week with temperatures well above normal by
weeks end. Gusty winds may return next weekend with potential for
light precipitation in the northern Sierra early next week.
&&
.SHORT TERM...
Strong gusty winds continued across the region today associated with
cold front nearby and enhanced pressure gradient. Some areas in
Mono/Mineral Counties hit what would normally be Red Flag criteria
with humidities below 10% and gusts 40-60 mph. This included the
Mammoth Airport for several hours. Winds will drop off rather
quickly tonight as gradient relaxes with incoming high pressure.
That shows up well in the HRRR guidance. Could still see a few light
rain/snow showers early this evening in far NE Cal and NW Nev but no
accumulations.
Tuesday looks to be a transition day, with gusty W/NW winds likely
north of a Susanville-Fallon line with the retreating front still in
the vicinity. Building high pressure just off the west coast will
yield warming temperatures aloft over the region and a weak NE low
level flow Wednesday-Thursday. Warming in valleys will be gradual as
a result but strong inversions are not anticipated. Overall looks to
be a prime week to get outdoor projects or yard work done. -Chris
.LONG TERM...Friday through Monday...
Forecast models continue to show the ridge axis shifting across the
Sierra and western Nevada on Friday and Saturday. Dry conditions
expected through the end of the week along with light northeast,
east winds for the Sierra and western Nevada. Temperatures will
climb into the upper 60s and near 70 degrees by Saturday as the
ridge axis shifts eastward and allows light west winds to return.
There is potential for the ridge to break down by late Saturday into
Sunday which will allow the large scale pattern to become a bit more
active again. Both operational models are targeting an upper level
jet along with some moisture towards the west coast. There is some
uncertainty where the jet will land, anywhere from the Lake Tahoe
Basin up towards the Pacific Northwest. There is some potential for
valley rain and mountain snow showers for late Sunday into Monday.
Edan
&&
.AVIATION...
The strong wind gusts around 60-80 kts across the Sierra ridges from
this morning will continue to diminish through the afternoon and
evening. Terminals in the eastern Sierra and western Nevada should
expect wind gusts decreasing to around 15-25 kts by this evening.
Only terminal that may still see wind gusts later in the evening
would be KMMH.
VFR conditions are expected to prevail across the area by this
afternoon and evening. Conditions have dried out considerably, so we
don`t anticipate fog forming in the Sierra valleys. Edan
&&
.REV Watches/Warnings/Advisories...
NV...Lake Wind Advisory until 8 PM PDT this evening for Pyramid Lake
in NVZ004.
Lake Wind Advisory until 8 PM PDT this evening for Lake Tahoe in
NVZ002.
CA...Lake Wind Advisory until 8 PM PDT this evening for Lake Tahoe in
CAZ072.
&&
$$
For more information from the National Weather Service visit...
http://weather.gov/reno
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
510 AM PDT SUN MAR 13 2016
...MORE RAIN THROUGH THIS EVENING...POSSIBLY HEAVY AT TIMES
TODAY ESPECIALLY OVER THE NORTH BAY...
.SYNOPSIS...PERIODS OF RAIN WILL PERSIST THROUGH LATE TODAY AS
ANOTHER STORM SYSTEM PUSHES THROUGH THE REGION. THE HEAVIEST
RAINFALL WILL BE OVER THE NORTH BAY AND ALONG THE COASTAL RANGES.
DRY WEATHER IS FORECAST FROM MONDAY AFTERNOON THROUGH THE END OF
THE WORK WEEK...ALONG WITH A WARMING TREND...AS HIGH PRESSURE
BUILDS ALONG THE WEST COAST. RAIN MAY RETURN NEXT WEEKEND.
&&
.DISCUSSION...AS OF 3:45 AM PDT SUNDAY...THE FIRST FRONTAL
BOUNDARY THAT BROUGHT WIDESPREAD RAIN TO THE SF BAY AREA ON
SATURDAY...AND A PERIOD OF HEAVY RAIN TO SAN FRANCISCO LATE
SATURDAY AFTERNOON...STALLED OVER SANTA CRUZ AND SANTA CLARA
COUNTY OVERNIGHT AND GRADUALLY WEAKENED. THE NEXT SYSTEM IS NOW
BEGINNING TO SPREAD RAIN INTO THE NORTH BAY. RAIN RATES IN THE
NORTH BAY HAVE BEEN LIGHT OVERNIGHT...BUT RAINFALL INTENSITY IS
EXPECTED TO RAMP UP OVER THE NEXT FEW HOURS. THE LATEST HRRR MODEL
SHOWS RAIN RATES INCREASING IN THE NORTH BAY BY 5 AM...SOUTH
ACROSS THE REST OF THE SF BAY AREA AND SANTA CRUZ COUNTY BY 8
AM...AND THEN SOUTH INTO MONTEREY AND SAN BENITO COUNTIES BY LATE
MORNING. PERIODS OF RAIN WILL THEN CONTINUE THROUGH THE AFTERNOON
AND INTO THE EVENING. RAIN MAY BE HEAVY AT TIMES...PARTICULARLY
ACROSS THE NORTH BAY AND IN THE HILLS SOUTH OF THE GOLDEN GATE.
ADDITIONAL RAINFALL AMOUNTS THROUGH LATE TODAY ARE FORECAST TO
RANGE FROM 1 TO 2 INCHES IN THE NORTH BAY...FROM 0.5-1.5" ACROSS
THE REMAINDER OF THE BAY AREA AND SANTA CRUZ COUNTY...AND FROM
0.25-1.25" ACROSS MONTEREY AND SAN BENITO COUNTIES. MINOR URBAN
FLOODING IS POSSIBLE ACROSS THE REGION TODAY DURING PERIODS OF
HEAVY RAIN. MORE SIGNIFICANT FLOODING...INCLUDING FLOODING ON
SMALL RIVERS AND STREAMS...IS POSSIBLE IN THE NORTH BAY WHERE
RECENT HEAVY RAIN HAS LEFT THE SOIL SATURATED AND RIVERS RUNNING
HIGH. A FLASH FLOOD WATCH REMAINS IN EFFECT FOR THE NORTH BAY
COUNTIES OF SONOMA...NAPA..AND MARIN THROUGH THIS AFTERNOON. THE
LARGER RIVERS ARE EXPECTED TO REMAIN BELOW FLOOD STAGE. THE MOST
SIGNIFICANT RISE IS FORECAST TO OCCUR ON THE LOWER RUSSIAN RIVER
WHICH IS PROJECTED TO CREST ABOUT THREE FEET BELOW FLOOD STAGE ON
MONDAY.
BREEZY CONDITIONS ARE FORECAST THROUGH THIS AFTERNOON...PARTICULARLY
IN THE HILLS OF THE SF BAY AREA AND ALONG THE COAST. HOWEVER...WINDS
ARE NOT EXPECTED TO REACH ADVISORY LEVELS...WITH LOCAL GUSTS UP
TO ABOUT 35 MPH.
PRECIPITATION IS FORECAST TO TAPER OFF THIS EVENING AND MOSTLY
END BY LATE TONIGHT. A FEW SHOWERS MAY LINGER INTO MONDAY
MORNING...WITH DRY CONDITIONS EXPECTED IN ALL AREAS BY MONDAY
AFTERNOON. THE AIRMASS MOVING INTO OUR AREA BY MONDAY WILL BE
RATHER COOL AND IF THERE IS SUFFICIENT CLEARING ON MONDAY NIGHT
TEMPERATURES WILL LIKELY DIP INTO THE UPPER 30S IN THE COOLEST
INLAND VALLEYS.
THE MODELS ARE IN AGREEMENT IN BUILDING AN UPPER RIDGE NEAR THE
WEST COAST AS THE WEEK PROGRESSES...AND DEVELOPING DRY OFFSHORE
FLOW BY MIDWEEK. THIS WILL RESULT IN A WARMING TREND THROUGH THE
WORK WEEK. WIDESPREAD 70S ARE LIKELY BY THURSDAY...WITH SOME LOWER
80S IN THE WARMER INLAND SPOTS.
THE LONGER RANGE MODELS INDICATE A CHANGE NEXT WEEKEND WITH THE
UPPER RIDGE MOVING OFF TO OUR EAST AND A BROAD TROUGH OVER THE
EASTERN PACIFIC EDGING TOWARDS THE WEST COAST. BOTH THE GFS AND
ECMWF FORECAST LIGHT PRECIP DEVELOPING ACROSS AT LEAST THE
NORTHERN PORTION OF OUR AREA BY LATE NEXT SATURDAY OR SUNDAY.
&&
.AVIATION...AS OF 10:18 PM PST SATURDAY...AN APPROACHING FRONT
TODAY WILL MAINTAIN SW FLOW ALOFT WHILE TERRAIN WILL KEEP WINDS
GENERALLY OUT OF THE SE-S. CIGS ARE EXPECTED TO BE MVFR TO VFR
FOR THE MOST PART WITH PERIODS OF IFR DURING BANDS OF HEAVY RAIN
AS TWO PULSES OF RAIN MOVE THROUGH TODAY. THE MAIN FRONT IS
EXPECTED TONIGHT INTO EARLY MONDAY WITH WIDESPREAD RAIN. A DRYING
TREND WILL BEGIN ON MONDAY ALLOWING FOR CLEARING CONDITIONS.
VICINITY OF KSFO...RAIN EARLY MORNING AND AFTERNOON WITH VICINITY
SHOWERS BETWEEN. VSBYS MAY OCCASIONALLY LOWER TO IFR DURING HEAVY
RAIN. SE-S WINDS 13-18 KNOTS THIS MORNING BECOMING GUSTY TO 23-28
KTS SUNDAY AFTERNOON AND EVENING AROUND THE COLD FRONT.
KSFO BRIDGE APPROACH...SIMILAR AS KSFO.
MONTEREY BAY AREA TERMINALS...VFR/MVFR. RAIN...HEAVY AT TIMES
THROUGH THE DAY. DRYING CONDITIONS ON MONDAY.
&&
.MARINE...AS OF 04:53 AM PDT SUNDAY...A COLD FRONT APPROACHING THE
WATERS WILL BRING FRESH TO STRONG SOUTHWESTERLY WINDS WITH HIGHER
GUSTS. THIS WILL DEVELOPING BUILDING STEEP SOUTHWEST WAVES. WINDS
WILL SHIFT TO THE NORTHWEST AND EASE BEHIND THE FRONT
TONIGHT...ALLOWING FOR THE STEEP WAVES TO SUBSIDE. HOWEVER...A
LONG PERIOD SWELL WILL ARRIVE IN THE WATERS TODAY DUE TO A ACTIVE
NORTH PACIFIC STORM. EXPECT BUILDING NW SWELL LATE THIS AFTERNOON
AND REMAINING THROUGH THE NIGHT. CONDITIONS WILL BEGIN TO ABATE ON
TUESDAY.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...HIGH SURF ADVISORY...ENTIRE COAST FROM SONOMA COUNTY
SOUTH TO MONTEREY COUNTY
FLASH FLOOD WATCH...NORTH BAY COUNTIES
SCA...MRY BAY
SCA...PT ARENA TO PT REYES 0-10 NM
SCA...PT REYES TO PIGEON PT 0-10 NM
SCA...PIGEON PT TO PT PINOS 0-10 NM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM
SCA...PT ARENA TO PIGEON PT 10-60 NM
SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM
SCA...ROUGH BAR ADVISORY FOR SF BAR
SCA...SF BAY
&&
$$
PUBLIC FORECAST: DYKEMA
AVIATION: BFG
MARINE: BFG
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AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
1117 AM PDT SUN MAR 13 2016
...MORE RAIN THROUGH THIS EVENING...POSSIBLY HEAVY AT TIMES
TODAY ESPECIALLY OVER THE NORTH BAY...
.SYNOPSIS...PERIODS OF RAIN WILL PERSIST THROUGH LATE TODAY AS
ANOTHER STORM SYSTEM PUSHES THROUGH THE REGION. THE HEAVIEST
RAINFALL WILL BE OVER THE NORTH BAY AND ALONG THE COASTAL RANGES.
DRY WEATHER IS FORECAST FROM MONDAY AFTERNOON THROUGH THE END OF
THE WORK WEEK...ALONG WITH A WARMING TREND...AS HIGH PRESSURE
BUILDS ALONG THE WEST COAST. RAIN MAY RETURN NEXT WEEKEND.
&&
.DISCUSSION...AS OF 9:20 AM PDT SUNDAY... KMUX RADAR SHOWING
WIDESPREAD LIGHT TO MODERATE RAIN ACROSS THE FORECAST AREA THIS
MORNING. 24 HOUR RAINFALL TOTALS AS OF 5AM ARE HIGHEST OVER THE
SANTA CRUZ MOUNTAINS (UP TO 2.71")... NORTH BAY MOUNTAINS (UP TO
1.65")... AND THE EAST BAY HILLS (UP TO 1.86"). DOWNTOWN SAN
FRANCISCO PICKED UP 1.22". ELSEWHERE... PRECIPITATION AMOUNTS HAVE
TOTALED FROM A FEW HUNDREDTHS TO AN INCH.
NORTHERN AND CENTRAL CALIFORNIA WILL BE POSITIONED DOWNSTREAM OF A
MOIST DIFFLUENT FLOW ALOFT TODAY AND INTO THIS EVENING. SATELLITE
IMAGERY SHOWS A POTENT 1.1"-1.3" PLUME OF PRECIPITABLE WATER
AIMED DIRECTLY AT NORTH AND CENTRAL CALIFORNIA THIS MORNING WHICH
WILL SUPPORT LIGHT TO MODERATE RAIN TODAY. MODELS SHOWED A SMALL
VORTICITY MAXIMA ASSOCIATED WITH THE LARGER UPPER LOW SWEEPING
ACROSS THE OREGON/WASHINGTON BORDER THIS MORNING... AND THIS
FEATURE IS NOW EVIDENT ON WATER VAPOR IMAGERY. THIS FEATURE MAY
HELP TO ENHANCE RAINFALL INTENSITY OVER THE NEXT FEW HOURS OVER
NORTHERN CALIFORNIA INCLUDING THE EXTREME NORTH BAY.
LATEST RIVER FORECAST CENTER GUIDANCE HAS INCREASED FORECAST
PRECIPITATION TOTALS... ESPECIALLY OVER THE EXTREME NORTH BAY AND
SANTA CRUZ MOUNTAINS. STORM TOTAL PRECIPITATION TOTALS FOR THE
EXTREME NORTH BAY NOW RUN 2 TO 4 INCHES... WHICH SUPPORT THE
CONTINUATION OF THE FLASH FLOOD WATCH IN THAT AREA THROUGH THIS
AFTERNOON. THE LATEST RUSSIAN RIVER FORECAST POINT AT GUERNEVILLE
STILL PROJECTS PEAK CRESTING JUST ABOVE MONITOR STAGE MONDAY
MORNING THROUGH THE EARLY AFTERNOON. AT 29 FEET (29.2 FEET IS
FORECAST)... MINOR FLOODING CAN BE EXPECTED ALONG THE LOWER
PORTIONS OF THE RUSSIAN RIVER NEAR GUERNEVILLE.
STEADY RAIN WILL GRADUALLY TAPER OFF AND TRANSITION INTO RAIN
SHOWERS BEGINNING LATE THIS AFTERNOON. LINGERING RAIN SHOWERS CAN
BE EXPECTED INTO MONDAY MORNING. THIS SHOULD BE THE LAST RAIN WE
SEE THROUGH THE UPCOMING WORK WEEK... AS A HIGH AMPLITUDE RIDGE OF
HIGH PRESSURE GRADUALLY BUILDS IN FROM THE EASTERN PACIFIC. THIS
WILL RESULT IN A GENERAL WARMING TREND FOR THE AREA... WITH THE
WARMEST TEMPERATURES EXPECTED THURSDAY AS THE RIDGE AXIS SHIFTS
ONSHORE. THURSDAY TEMPERATURES ARE FORECAST TO BE AROUND 10 TO 15
DEGREES ABOVE SEASONAL NORMALS FOR THE ENTIRE AREA. THE NEXT BIG
SHIFT IN THE WEATHER COULD COME NEXT WEEKEND WHILE A LARGE UPPER
LOW IN THE GULF OF ALASKA.
.PREVIOUS DISCUSSION...AS OF 3:45 AM PDT SUNDAY...THE FIRST
FRONTAL BOUNDARY THAT BROUGHT WIDESPREAD RAIN TO THE SF BAY AREA
ON SATURDAY...AND A PERIOD OF HEAVY RAIN TO SAN FRANCISCO LATE
SATURDAY AFTERNOON...STALLED OVER SANTA CRUZ AND SANTA CLARA
COUNTY OVERNIGHT AND GRADUALLY WEAKENED. THE NEXT SYSTEM IS NOW
BEGINNING TO SPREAD RAIN INTO THE NORTH BAY. RAIN RATES IN THE
NORTH BAY HAVE BEEN LIGHT OVERNIGHT...BUT RAINFALL INTENSITY IS
EXPECTED TO RAMP UP OVER THE NEXT FEW HOURS. THE LATEST HRRR MODEL
SHOWS RAIN RATES INCREASING IN THE NORTH BAY BY 5 AM...SOUTH
ACROSS THE REST OF THE SF BAY AREA AND SANTA CRUZ COUNTY BY 8
AM...AND THEN SOUTH INTO MONTEREY AND SAN BENITO COUNTIES BY LATE
MORNING. PERIODS OF RAIN WILL THEN CONTINUE THROUGH THE AFTERNOON
AND INTO THE EVENING. RAIN MAY BE HEAVY AT TIMES...PARTICULARLY
ACROSS THE NORTH BAY AND IN THE HILLS SOUTH OF THE GOLDEN GATE.
ADDITIONAL RAINFALL AMOUNTS THROUGH LATE TODAY ARE FORECAST TO
RANGE FROM 1 TO 2 INCHES IN THE NORTH BAY...FROM 0.5-1.5" ACROSS
THE REMAINDER OF THE BAY AREA AND SANTA CRUZ COUNTY...AND FROM
0.25-1.25" ACROSS MONTEREY AND SAN BENITO COUNTIES. MINOR URBAN
FLOODING IS POSSIBLE ACROSS THE REGION TODAY DURING PERIODS OF
HEAVY RAIN. MORE SIGNIFICANT FLOODING...INCLUDING FLOODING ON
SMALL RIVERS AND STREAMS...IS POSSIBLE IN THE NORTH BAY WHERE
RECENT HEAVY RAIN HAS LEFT THE SOIL SATURATED AND RIVERS RUNNING
HIGH. A FLASH FLOOD WATCH REMAINS IN EFFECT FOR THE NORTH BAY
COUNTIES OF SONOMA...NAPA..AND MARIN THROUGH THIS AFTERNOON. THE
LARGER RIVERS ARE EXPECTED TO REMAIN BELOW FLOOD STAGE. THE MOST
SIGNIFICANT RISE IS FORECAST TO OCCUR ON THE LOWER RUSSIAN RIVER
WHICH IS PROJECTED TO CREST ABOUT THREE FEET BELOW FLOOD STAGE ON
MONDAY.
BREEZY CONDITIONS ARE FORECAST THROUGH THIS AFTERNOON...PARTICULARLY
IN THE HILLS OF THE SF BAY AREA AND ALONG THE COAST. HOWEVER...WINDS
ARE NOT EXPECTED TO REACH ADVISORY LEVELS...WITH LOCAL GUSTS UP
TO ABOUT 35 MPH.
PRECIPITATION IS FORECAST TO TAPER OFF THIS EVENING AND MOSTLY
END BY LATE TONIGHT. A FEW SHOWERS MAY LINGER INTO MONDAY
MORNING...WITH DRY CONDITIONS EXPECTED IN ALL AREAS BY MONDAY
AFTERNOON. THE AIRMASS MOVING INTO OUR AREA BY MONDAY WILL BE
RATHER COOL AND IF THERE IS SUFFICIENT CLEARING ON MONDAY NIGHT
TEMPERATURES WILL LIKELY DIP INTO THE UPPER 30S IN THE COOLEST
INLAND VALLEYS.
THE MODELS ARE IN AGREEMENT IN BUILDING AN UPPER RIDGE NEAR THE
WEST COAST AS THE WEEK PROGRESSES...AND DEVELOPING DRY OFFSHORE
FLOW BY MIDWEEK. THIS WILL RESULT IN A WARMING TREND THROUGH THE
WORK WEEK. WIDESPREAD 70S ARE LIKELY BY THURSDAY...WITH SOME LOWER
80S IN THE WARMER INLAND SPOTS.
THE LONGER RANGE MODELS INDICATE A CHANGE NEXT WEEKEND WITH THE
UPPER RIDGE MOVING OFF TO OUR EAST AND A BROAD TROUGH OVER THE
EASTERN PACIFIC EDGING TOWARDS THE WEST COAST. BOTH THE GFS AND
ECMWF FORECAST LIGHT PRECIP DEVELOPING ACROSS AT LEAST THE
NORTHERN PORTION OF OUR AREA BY LATE NEXT SATURDAY OR SUNDAY.
&&
.AVIATION...AS OF 11:15 AM PDT SATURDAY...WIDESPREAD RAIN ACROSS
OUR AREA TODAY WHICH IS CAUSING CIGS TO BOUNCE UP AND DOWN FROM
MVFR TO VFR. AT THE SAME TIME WINDS WILL CONTINUE TO SLOWLY GO
MORE TO THE 230 TO 260 DIRECTION. NEEDLESS TO SAY, LOW CONFIDENCE
FORECAST WITH THE SPECIFICS FOR ALL OF THE TAFS.
VICINITY OF SFO...WINDS OF 200 TO 230 FORECAST TO INCREASE AROUND
20Z WITH GUSTS OVER 25 KT FORECAST. CIGS FORECAST TO MOSTLY STAY
MVFR TODAY. RAIN SWITCHES TO -SHRA AFTER 01Z AND THEN MOSTLY DRY
AFTER 04Z. LOW CONFIDENCE.
KSFO BRIDGE APPROACH...SIMILAR AS KSFO.
MONTEREY BAY AREA TERMINALS...VFR/MVFR. RAIN THROUGH MOST OF THE
DAY WITH CIGS MVFR TO POSSIBLY VFR. LOW CONFIDENCE.
&&
.MARINE...AS OF 11:15 AM PDT SUNDAY...LOOK FOR GUSTY SOUTHWESTERLY
WINDS TODAY AS A COLD FRONT GOES THROUGH. THE WINDS WILL ALSO
PRODUCE STEEP SOUTHWEST WAVES. WINDS WILL SHIFT TO THE NORTHWEST
AND EASE BEHIND THE FRONT TONIGHT...ALLOWING FOR THE STEEP WAVES
TO SUBSIDE. HOWEVER...A LONG PERIOD SWELL WILL ARRIVE IN THE
WATERS TODAY DUE TO A ACTIVE NORTH PACIFIC STORM. EXPECT BUILDING
NW SWELL LATE THIS AFTERNOON AND REMAINING THROUGH THE NIGHT.
CONDITIONS WILL BEGIN TO ABATE ON TUESDAY.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...HIGH SURF ADVISORY...ALL COASTAL LOCATIONS
FLASH FLOOD WATCH...NORTH BAY
SCA...MRY BAY
SCA...PT ARENA TO PT REYES 0-10 NM
SCA...PT REYES TO PIGEON PT 0-10 NM
SCA...PIGEON PT TO PT PINOS 0-10 NM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM
SCA...PT ARENA TO PIGEON PT 10-60 NM
SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM
SCA...ROUGH BAR ADVISORY FOR SF BAR
SCA...SF BAY
&&
$$
PUBLIC FORECAST: DRP
AVIATION: BELL
MARINE: BELL
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
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AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
923 AM PDT SUN MAR 13 2016
...MORE RAIN THROUGH THIS EVENING...POSSIBLY HEAVY AT TIMES
TODAY ESPECIALLY OVER THE NORTH BAY...
.SYNOPSIS...PERIODS OF RAIN WILL PERSIST THROUGH LATE TODAY AS
ANOTHER STORM SYSTEM PUSHES THROUGH THE REGION. THE HEAVIEST
RAINFALL WILL BE OVER THE NORTH BAY AND ALONG THE COASTAL RANGES.
DRY WEATHER IS FORECAST FROM MONDAY AFTERNOON THROUGH THE END OF
THE WORK WEEK...ALONG WITH A WARMING TREND...AS HIGH PRESSURE
BUILDS ALONG THE WEST COAST. RAIN MAY RETURN NEXT WEEKEND.
&&
.DISCUSSION...AS OF 9:20 AM PDT SUNDAY... KMUX RADAR SHOWING
WIDESPREAD LIGHT TO MODERATE RAIN ACROSS THE FORECAST AREA THIS
MORNING. 24 HOUR RAINFALL TOTALS AS OF 5AM ARE HIGHEST OVER THE
SANTA CRUZ MOUNTAINS (UP TO 2.71")... NORTH BAY MOUNTAINS (UP TO
1.65")... AND THE EAST BAY HILLS (UP TO 1.86"). DOWNTOWN SAN
FRANCISCO PICKED UP 1.22". ELSEWHERE... PRECIPITATION AMOUNTS HAVE
TOTALED FROM A FEW HUNDREDTHS TO AN INCH.
NORTHERN AND CENTRAL CALIFORNIA WILL BE POSITIONED DOWNSTREAM OF A
MOIST DIFFLUENT FLOW ALOFT TODAY AND INTO THIS EVENING. SATELLITE
IMAGERY SHOWS A POTENT 1.1"-1.3" PLUME OF PRECIPITABLE WATER
AIMED DIRECTLY AT NORTH AND CENTRAL CALIFORNIA THIS MORNING WHICH
WILL SUPPORT LIGHT TO MODERATE RAIN TODAY. MODELS SHOWED A SMALL
VORTICITY MAXIMA ASSOCIATED WITH THE LARGER UPPER LOW SWEEPING
ACROSS THE OREGON/WASHINGTON BORDER THIS MORNING... AND THIS
FEATURE IS NOW EVIDENT ON WATER VAPOR IMAGERY. THIS FEATURE MAY
HELP TO ENHANCE RAINFALL INTENSITY OVER THE NEXT FEW HOURS OVER
NORTHERN CALIFORNIA INCLUDING THE EXTREME NORTH BAY.
LATEST RIVER FORECAST CENTER GUIDANCE HAS INCREASED FORECAST
PRECIPITATION TOTALS... ESPECIALLY OVER THE EXTREME NORTH BAY AND
SANTA CRUZ MOUNTAINS. STORM TOTAL PRECIPITATION TOTALS FOR THE
EXTREME NORTH BAY NOW RUN 2 TO 4 INCHES... WHICH SUPPORT THE
CONTINUATION OF THE FLASH FLOOD WATCH IN THAT AREA THROUGH THIS
AFTERNOON. THE LATEST RUSSIAN RIVER FORECAST POINT AT GUERNEVILLE
STILL PROJECTS PEAK CRESTING JUST ABOVE MONITOR STAGE MONDAY
MORNING THROUGH THE EARLY AFTERNOON. AT 29 FEET (29.2 FEET IS
FORECAST)... MINOR FLOODING CAN BE EXPECTED ALONG THE LOWER
PORTIONS OF THE RUSSIAN RIVER NEAR GUERNEVILLE.
STEADY RAIN WILL GRADUALLY TAPER OFF AND TRANSITION INTO RAIN
SHOWERS BEGINNING LATE THIS AFTERNOON. LINGERING RAIN SHOWERS CAN
BE EXPECTED INTO MONDAY MORNING. THIS SHOULD BE THE LAST RAIN WE
SEE THROUGH THE UPCOMING WORK WEEK... AS A HIGH AMPLITUDE RIDGE OF
HIGH PRESSURE GRADUALLY BUILDS IN FROM THE EASTERN PACIFIC. THIS
WILL RESULT IN A GENERAL WARMING TREND FOR THE AREA... WITH THE
WARMEST TEMPERATURES EXPECTED THURSDAY AS THE RIDGE AXIS SHIFTS
ONSHORE. THURSDAY TEMPERATURES ARE FORECAST TO BE AROUND 10 TO 15
DEGREES ABOVE SEASONAL NORMALS FOR THE ENTIRE AREA. THE NEXT BIG
SHIFT IN THE WEATHER COULD COME NEXT WEEKEND WHILE A LARGE UPPER
LOW IN THE GULF OF ALASKA.
.PREVIOUS DISCUSSION...AS OF 3:45 AM PDT SUNDAY...THE FIRST
FRONTAL BOUNDARY THAT BROUGHT WIDESPREAD RAIN TO THE SF BAY AREA
ON SATURDAY...AND A PERIOD OF HEAVY RAIN TO SAN FRANCISCO LATE
SATURDAY AFTERNOON...STALLED OVER SANTA CRUZ AND SANTA CLARA
COUNTY OVERNIGHT AND GRADUALLY WEAKENED. THE NEXT SYSTEM IS NOW
BEGINNING TO SPREAD RAIN INTO THE NORTH BAY. RAIN RATES IN THE
NORTH BAY HAVE BEEN LIGHT OVERNIGHT...BUT RAINFALL INTENSITY IS
EXPECTED TO RAMP UP OVER THE NEXT FEW HOURS. THE LATEST HRRR MODEL
SHOWS RAIN RATES INCREASING IN THE NORTH BAY BY 5 AM...SOUTH
ACROSS THE REST OF THE SF BAY AREA AND SANTA CRUZ COUNTY BY 8
AM...AND THEN SOUTH INTO MONTEREY AND SAN BENITO COUNTIES BY LATE
MORNING. PERIODS OF RAIN WILL THEN CONTINUE THROUGH THE AFTERNOON
AND INTO THE EVENING. RAIN MAY BE HEAVY AT TIMES...PARTICULARLY
ACROSS THE NORTH BAY AND IN THE HILLS SOUTH OF THE GOLDEN GATE.
ADDITIONAL RAINFALL AMOUNTS THROUGH LATE TODAY ARE FORECAST TO
RANGE FROM 1 TO 2 INCHES IN THE NORTH BAY...FROM 0.5-1.5" ACROSS
THE REMAINDER OF THE BAY AREA AND SANTA CRUZ COUNTY...AND FROM
0.25-1.25" ACROSS MONTEREY AND SAN BENITO COUNTIES. MINOR URBAN
FLOODING IS POSSIBLE ACROSS THE REGION TODAY DURING PERIODS OF
HEAVY RAIN. MORE SIGNIFICANT FLOODING...INCLUDING FLOODING ON
SMALL RIVERS AND STREAMS...IS POSSIBLE IN THE NORTH BAY WHERE
RECENT HEAVY RAIN HAS LEFT THE SOIL SATURATED AND RIVERS RUNNING
HIGH. A FLASH FLOOD WATCH REMAINS IN EFFECT FOR THE NORTH BAY
COUNTIES OF SONOMA...NAPA..AND MARIN THROUGH THIS AFTERNOON. THE
LARGER RIVERS ARE EXPECTED TO REMAIN BELOW FLOOD STAGE. THE MOST
SIGNIFICANT RISE IS FORECAST TO OCCUR ON THE LOWER RUSSIAN RIVER
WHICH IS PROJECTED TO CREST ABOUT THREE FEET BELOW FLOOD STAGE ON
MONDAY.
BREEZY CONDITIONS ARE FORECAST THROUGH THIS AFTERNOON...PARTICULARLY
IN THE HILLS OF THE SF BAY AREA AND ALONG THE COAST. HOWEVER...WINDS
ARE NOT EXPECTED TO REACH ADVISORY LEVELS...WITH LOCAL GUSTS UP
TO ABOUT 35 MPH.
PRECIPITATION IS FORECAST TO TAPER OFF THIS EVENING AND MOSTLY
END BY LATE TONIGHT. A FEW SHOWERS MAY LINGER INTO MONDAY
MORNING...WITH DRY CONDITIONS EXPECTED IN ALL AREAS BY MONDAY
AFTERNOON. THE AIRMASS MOVING INTO OUR AREA BY MONDAY WILL BE
RATHER COOL AND IF THERE IS SUFFICIENT CLEARING ON MONDAY NIGHT
TEMPERATURES WILL LIKELY DIP INTO THE UPPER 30S IN THE COOLEST
INLAND VALLEYS.
THE MODELS ARE IN AGREEMENT IN BUILDING AN UPPER RIDGE NEAR THE
WEST COAST AS THE WEEK PROGRESSES...AND DEVELOPING DRY OFFSHORE
FLOW BY MIDWEEK. THIS WILL RESULT IN A WARMING TREND THROUGH THE
WORK WEEK. WIDESPREAD 70S ARE LIKELY BY THURSDAY...WITH SOME LOWER
80S IN THE WARMER INLAND SPOTS.
THE LONGER RANGE MODELS INDICATE A CHANGE NEXT WEEKEND WITH THE
UPPER RIDGE MOVING OFF TO OUR EAST AND A BROAD TROUGH OVER THE
EASTERN PACIFIC EDGING TOWARDS THE WEST COAST. BOTH THE GFS AND
ECMWF FORECAST LIGHT PRECIP DEVELOPING ACROSS AT LEAST THE
NORTHERN PORTION OF OUR AREA BY LATE NEXT SATURDAY OR SUNDAY.
&&
.AVIATION...AS OF 5:15 AM PST SATURDAY...AN APPROACHING FRONT TODAY
WILL MAINTAIN SW FLOW ALOFT WHILE TERRAIN WILL KEEP WINDS GENERALLY
OUT OF THE SE-S. CIGS ARE EXPECTED TO BE MVFR TO VFR FOR THE MOST
PART WITH PERIODS OF IFR DURING BANDS OF HEAVY RAIN AS TWO PULSES OF
RAIN MOVE THROUGH TODAY. THE MAIN FRONT IS EXPECTED TONIGHT INTO
EARLY MONDAY WITH WIDESPREAD RAIN. A DRYING TREND WILL BEGIN ON
MONDAY ALLOWING FOR CLEARING CONDITIONS.
VICINITY OF SFO...RAIN EARLY MORNING AND AFTERNOON WITH VICINITY
SHOWERS BETWEEN. VSBYS MAY OCCASIONALLY LOWER TO IFR DURING HEAVY
RAIN. SE-S WINDS 13-18 KNOTS THIS MORNING BECOMING GUSTY TO 23-28
KTS SUNDAY AFTERNOON AND EVENING AROUND THE COLD FRONT.
KSFO BRIDGE APPROACH...SIMILAR AS KSFO.
MONTEREY BAY AREA TERMINALS...VFR/MVFR. RAIN...HEAVY AT TIMES
THROUGH THE DAY. DRYING CONDITIONS ON MONDAY.
&&
.MARINE...AS OF 08:40 AM PDT SUNDAY...A COLD FRONT APPROACHING THE
WATERS WILL BRING FRESH TO STRONG SOUTHWESTERLY WINDS WITH HIGHER
GUSTS. THIS WILL DEVELOPING BUILDING STEEP SOUTHWEST WAVES. WINDS
WILL SHIFT TO THE NORTHWEST AND EASE BEHIND THE FRONT
TONIGHT...ALLOWING FOR THE STEEP WAVES TO SUBSIDE. HOWEVER...A
LONG PERIOD SWELL WILL ARRIVE IN THE WATERS TODAY DUE TO A ACTIVE
NORTH PACIFIC STORM. EXPECT BUILDING NW SWELL LATE THIS AFTERNOON
AND REMAINING THROUGH THE NIGHT. CONDITIONS WILL BEGIN TO ABATE ON
TUESDAY.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...HIGH SURF ADVISORY...ENTIRE COAST FROM SONOMA COUNTY
SOUTH TO MONTEREY COUNTY
FLASH FLOOD WATCH...NORTH BAY COUNTIES
SCA...MRY BAY
SCA...PT ARENA TO PT REYES 0-10 NM
SCA...PT REYES TO PIGEON PT 0-10 NM
SCA...PIGEON PT TO PT PINOS 0-10 NM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM
SCA...PT ARENA TO PIGEON PT 10-60 NM
SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM
SCA...ROUGH BAR ADVISORY FOR SF BAR
SCA...SF BAY
&&
$$
PUBLIC FORECAST: DRP
AVIATION: BFG
MARINE: BFG
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
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AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
543 AM PDT SUN MAR 13 2016
...MORE RAIN THROUGH THIS EVENING...POSSIBLY HEAVY AT TIMES
TODAY ESPECIALLY OVER THE NORTH BAY...
.SYNOPSIS...PERIODS OF RAIN WILL PERSIST THROUGH LATE TODAY AS
ANOTHER STORM SYSTEM PUSHES THROUGH THE REGION. THE HEAVIEST
RAINFALL WILL BE OVER THE NORTH BAY AND ALONG THE COASTAL RANGES.
DRY WEATHER IS FORECAST FROM MONDAY AFTERNOON THROUGH THE END OF
THE WORK WEEK...ALONG WITH A WARMING TREND...AS HIGH PRESSURE
BUILDS ALONG THE WEST COAST. RAIN MAY RETURN NEXT WEEKEND.
&&
.DISCUSSION...AS OF 3:45 AM PDT SUNDAY...THE FIRST FRONTAL
BOUNDARY THAT BROUGHT WIDESPREAD RAIN TO THE SF BAY AREA ON
SATURDAY...AND A PERIOD OF HEAVY RAIN TO SAN FRANCISCO LATE
SATURDAY AFTERNOON...STALLED OVER SANTA CRUZ AND SANTA CLARA
COUNTY OVERNIGHT AND GRADUALLY WEAKENED. THE NEXT SYSTEM IS NOW
BEGINNING TO SPREAD RAIN INTO THE NORTH BAY. RAIN RATES IN THE
NORTH BAY HAVE BEEN LIGHT OVERNIGHT...BUT RAINFALL INTENSITY IS
EXPECTED TO RAMP UP OVER THE NEXT FEW HOURS. THE LATEST HRRR MODEL
SHOWS RAIN RATES INCREASING IN THE NORTH BAY BY 5 AM...SOUTH
ACROSS THE REST OF THE SF BAY AREA AND SANTA CRUZ COUNTY BY 8
AM...AND THEN SOUTH INTO MONTEREY AND SAN BENITO COUNTIES BY LATE
MORNING. PERIODS OF RAIN WILL THEN CONTINUE THROUGH THE AFTERNOON
AND INTO THE EVENING. RAIN MAY BE HEAVY AT TIMES...PARTICULARLY
ACROSS THE NORTH BAY AND IN THE HILLS SOUTH OF THE GOLDEN GATE.
ADDITIONAL RAINFALL AMOUNTS THROUGH LATE TODAY ARE FORECAST TO
RANGE FROM 1 TO 2 INCHES IN THE NORTH BAY...FROM 0.5-1.5" ACROSS
THE REMAINDER OF THE BAY AREA AND SANTA CRUZ COUNTY...AND FROM
0.25-1.25" ACROSS MONTEREY AND SAN BENITO COUNTIES. MINOR URBAN
FLOODING IS POSSIBLE ACROSS THE REGION TODAY DURING PERIODS OF
HEAVY RAIN. MORE SIGNIFICANT FLOODING...INCLUDING FLOODING ON
SMALL RIVERS AND STREAMS...IS POSSIBLE IN THE NORTH BAY WHERE
RECENT HEAVY RAIN HAS LEFT THE SOIL SATURATED AND RIVERS RUNNING
HIGH. A FLASH FLOOD WATCH REMAINS IN EFFECT FOR THE NORTH BAY
COUNTIES OF SONOMA...NAPA..AND MARIN THROUGH THIS AFTERNOON. THE
LARGER RIVERS ARE EXPECTED TO REMAIN BELOW FLOOD STAGE. THE MOST
SIGNIFICANT RISE IS FORECAST TO OCCUR ON THE LOWER RUSSIAN RIVER
WHICH IS PROJECTED TO CREST ABOUT THREE FEET BELOW FLOOD STAGE ON
MONDAY.
BREEZY CONDITIONS ARE FORECAST THROUGH THIS AFTERNOON...PARTICULARLY
IN THE HILLS OF THE SF BAY AREA AND ALONG THE COAST. HOWEVER...WINDS
ARE NOT EXPECTED TO REACH ADVISORY LEVELS...WITH LOCAL GUSTS UP
TO ABOUT 35 MPH.
PRECIPITATION IS FORECAST TO TAPER OFF THIS EVENING AND MOSTLY
END BY LATE TONIGHT. A FEW SHOWERS MAY LINGER INTO MONDAY
MORNING...WITH DRY CONDITIONS EXPECTED IN ALL AREAS BY MONDAY
AFTERNOON. THE AIRMASS MOVING INTO OUR AREA BY MONDAY WILL BE
RATHER COOL AND IF THERE IS SUFFICIENT CLEARING ON MONDAY NIGHT
TEMPERATURES WILL LIKELY DIP INTO THE UPPER 30S IN THE COOLEST
INLAND VALLEYS.
THE MODELS ARE IN AGREEMENT IN BUILDING AN UPPER RIDGE NEAR THE
WEST COAST AS THE WEEK PROGRESSES...AND DEVELOPING DRY OFFSHORE
FLOW BY MIDWEEK. THIS WILL RESULT IN A WARMING TREND THROUGH THE
WORK WEEK. WIDESPREAD 70S ARE LIKELY BY THURSDAY...WITH SOME LOWER
80S IN THE WARMER INLAND SPOTS.
THE LONGER RANGE MODELS INDICATE A CHANGE NEXT WEEKEND WITH THE
UPPER RIDGE MOVING OFF TO OUR EAST AND A BROAD TROUGH OVER THE
EASTERN PACIFIC EDGING TOWARDS THE WEST COAST. BOTH THE GFS AND
ECMWF FORECAST LIGHT PRECIP DEVELOPING ACROSS AT LEAST THE
NORTHERN PORTION OF OUR AREA BY LATE NEXT SATURDAY OR SUNDAY.
&&
.AVIATION...AS OF 5:15 AM PST SATURDAY...AN APPROACHING FRONT TODAY
WILL MAINTAIN SW FLOW ALOFT WHILE TERRAIN WILL KEEP WINDS GENERALLY
OUT OF THE SE-S. CIGS ARE EXPECTED TO BE MVFR TO VFR FOR THE MOST
PART WITH PERIODS OF IFR DURING BANDS OF HEAVY RAIN AS TWO PULSES OF
RAIN MOVE THROUGH TODAY. THE MAIN FRONT IS EXPECTED TONIGHT INTO
EARLY MONDAY WITH WIDESPREAD RAIN. A DRYING TREND WILL BEGIN ON
MONDAY ALLOWING FOR CLEARING CONDITIONS.
VICINITY OF SFO...RAIN EARLY MORNING AND AFTERNOON WITH VICINITY
SHOWERS BETWEEN. VSBYS MAY OCCASIONALLY LOWER TO IFR DURING HEAVY
RAIN. SE-S WINDS 13-18 KNOTS THIS MORNING BECOMING GUSTY TO 23-28
KTS SUNDAY AFTERNOON AND EVENING AROUND THE COLD FRONT.
KSFO BRIDGE APPROACH...SIMILAR AS KSFO.
MONTEREY BAY AREA TERMINALS...VFR/MVFR. RAIN...HEAVY AT TIMES
THROUGH THE DAY. DRYING CONDITIONS ON MONDAY.
&&
.MARINE...AS OF 04:53 AM PDT SUNDAY...A COLD FRONT APPROACHING THE
WATERS WILL BRING FRESH TO STRONG SOUTHWESTERLY WINDS WITH HIGHER
GUSTS. THIS WILL DEVELOPING BUILDING STEEP SOUTHWEST WAVES. WINDS
WILL SHIFT TO THE NORTHWEST AND EASE BEHIND THE FRONT
TONIGHT...ALLOWING FOR THE STEEP WAVES TO SUBSIDE. HOWEVER...A
LONG PERIOD SWELL WILL ARRIVE IN THE WATERS TODAY DUE TO A ACTIVE
NORTH PACIFIC STORM. EXPECT BUILDING NW SWELL LATE THIS AFTERNOON
AND REMAINING THROUGH THE NIGHT. CONDITIONS WILL BEGIN TO ABATE ON
TUESDAY.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...HIGH SURF ADVISORY...ENTIRE COAST FROM SONOMA COUNTY
SOUTH TO MONTEREY COUNTY
FLASH FLOOD WATCH...NORTH BAY COUNTIES
SCA...MRY BAY
SCA...PT ARENA TO PT REYES 0-10 NM
SCA...PT REYES TO PIGEON PT 0-10 NM
SCA...PIGEON PT TO PT PINOS 0-10 NM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM
SCA...PT ARENA TO PIGEON PT 10-60 NM
SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM
SCA...ROUGH BAR ADVISORY FOR SF BAR
SCA...SF BAY
&&
$$
PUBLIC FORECAST: DYKEMA
AVIATION: BFG
MARINE: BFG
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
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AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
346 AM PDT SUN MAR 13 2016
...MORE RAIN THROUGH THIS EVENING...POSSIBLY HEAVY AT TIMES
TODAY ESPECIALLY OVER THE NORTH BAY...
.SYNOPSIS...PERIODS OF RAIN WILL PERSIST THROUGH LATE TODAY AS
ANOTHER STORM SYSTEM PUSHES THROUGH THE REGION. THE HEAVIEST
RAINFALL WILL BE OVER THE NORTH BAY AND ALONG THE COASTAL RANGES.
DRY WEATHER IS FORECAST FROM MONDAY AFTERNOON THROUGH THE END OF
THE WORK WEEK...ALONG WITH A WARMING TREND...AS HIGH PRESSURE
BUILDS ALONG THE WEST COAST. RAIN MAY RETURN NEXT WEEKEND.
&&
.DISCUSSION...AS OF 3:45 AM PDT SUNDAY...THE FIRST FRONTAL
BOUNDARY THAT BROUGHT WIDESPREAD RAIN TO THE SF BAY AREA ON
SATURDAY...AND A PERIOD OF HEAVY RAIN TO SAN FRANCISCO LATE
SATURDAY AFTERNOON...STALLED OVER SANTA CRUZ AND SANTA CLARA
COUNTY OVERNIGHT AND GRADUALLY WEAKENED. THE NEXT SYSTEM IS NOW
BEGINNING TO SPREAD RAIN INTO THE NORTH BAY. RAIN RATES IN THE
NORTH BAY HAVE BEEN LIGHT OVERNIGHT...BUT RAINFALL INTENSITY IS
EXPECTED TO RAMP UP OVER THE NEXT FEW HOURS. THE LATEST HRRR MODEL
SHOWS RAIN RATES INCREASING IN THE NORTH BAY BY 5 AM...SOUTH
ACROSS THE REST OF THE SF BAY AREA AND SANTA CRUZ COUNTY BY 8
AM...AND THEN SOUTH INTO MONTEREY AND SAN BENITO COUNTIES BY LATE
MORNING. PERIODS OF RAIN WILL THEN CONTINUE THROUGH THE AFTERNOON
AND INTO THE EVENING. RAIN MAY BE HEAVY AT TIMES...PARTICULARLY
ACROSS THE NORTH BAY AND IN THE HILLS SOUTH OF THE GOLDEN GATE.
ADDITIONAL RAINFALL AMOUNTS THROUGH LATE TODAY ARE FORECAST TO
RANGE FROM 1 TO 2 INCHES IN THE NORTH BAY...FROM 0.5-1.5" ACROSS
THE REMAINDER OF THE BAY AREA AND SANTA CRUZ COUNTY...AND FROM
0.25-1.25" ACROSS MONTEREY AND SAN BENITO COUNTIES. MINOR URBAN
FLOODING IS POSSIBLE ACROSS THE REGION TODAY DURING PERIODS OF
HEAVY RAIN. MORE SIGNIFICANT FLOODING...INCLUDING FLOODING ON
SMALL RIVERS AND STREAMS...IS POSSIBLE IN THE NORTH BAY WHERE
RECENT HEAVY RAIN HAS LEFT THE SOIL SATURATED AND RIVERS RUNNING
HIGH. A FLASH FLOOD WATCH REMAINS IN EFFECT FOR THE NORTH BAY
COUNTIES OF SONOMA...NAPA..AND MARIN THROUGH THIS AFTERNOON. THE
LARGER RIVERS ARE EXPECTED TO REMAIN BELOW FLOOD STAGE. THE MOST
SIGNIFICANT RISE IS FORECAST TO OCCUR ON THE LOWER RUSSIAN RIVER
WHICH IS PROJECTED TO CREST ABOUT THREE FEET BELOW FLOOD STAGE ON
MONDAY.
BREEZY CONDITIONS ARE FORECAST THROUGH THIS AFTERNOON...PARTICULARLY
IN THE HILLS OF THE SF BAY AREA AND ALONG THE COAST. HOWEVER...WINDS
ARE NOT EXPECTED TO REACH ADVISORY LEVELS...WITH LOCAL GUSTS UP
TO ABOUT 35 MPH.
PRECIPITATION IS FORECAST TO TAPER OFF THIS EVENING AND MOSTLY
END BY LATE TONIGHT. A FEW SHOWERS MAY LINGER INTO MONDAY
MORNING...WITH DRY CONDITIONS EXPECTED IN ALL AREAS BY MONDAY
AFTERNOON. THE AIRMASS MOVING INTO OUR AREA BY MONDAY WILL BE
RATHER COOL AND IF THERE IS SUFFICIENT CLEARING ON MONDAY NIGHT
TEMPERATURES WILL LIKELY DIP INTO THE UPPER 30S IN THE COOLEST
INLAND VALLEYS.
THE MODELS ARE IN AGREEMENT IN BUILDING AN UPPER RIDGE NEAR THE
WEST COAST AS THE WEEK PROGRESSES...AND DEVELOPING DRY OFFSHORE
FLOW BY MIDWEEK. THIS WILL RESULT IN A WARMING TREND THROUGH THE
WORK WEEK. WIDESPREAD 70S ARE LIKELY BY THURSDAY...WITH SOME LOWER
80S IN THE WARMER INLAND SPOTS.
THE LONGER RANGE MODELS INDICATE A CHANGE NEXT WEEKEND WITH THE
UPPER RIDGE MOVING OFF TO OUR EAST AND A BROAD TROUGH OVER THE
EASTERN PACIFIC EDGING TOWARDS THE WEST COAST. BOTH THE GFS AND
ECMWF FORECAST LIGHT PRECIP DEVELOPING ACROSS AT LEAST THE
NORTHERN PORTION OF OUR AREA BY LATE NEXT SATURDAY OR SUNDAY.
&&
.AVIATION...AS OF 10:18 PM PST SATURDAY...MVFR CIGS/VSBYS LOCALLY
IFR. SE-S SURFACE WINDS AND SW-W FLOW ALOFT TONIGHT AND SUNDAY.
SW-W FLOW ALOFT CONDUCIVE TO ADDITIONAL RAIN INTO SUNDAY...WX
PATTERN IS NEARLY STATIONARY. COLD FRONT MOVES SE OVER THE AREA
SUNDAY EVENING THROUGH EARLY MONDAY MORNING. DRIER MONDAY.
VICINITY OF SFO...RAIN. VSBYS MAY OCCASIONALLY LOWER TO IFR. SE-S
WINDS 10-15 KNOTS OVERNIGHT BECOMING GUSTY TO 20-25 KTS SUNDAY
AFTERNOON AND EVENING.
KSFO BRIDGE APPROACH...SIMILAR AS KSFO.
MONTEREY BAY AREA TERMINALS...VFR/MVFR. PERIODS OF LIGHT RAIN
DEVELOPING OVERNIGHT INTO SUNDAY.
&&
.MARINE...AS OF 9:08 PM PST SATURDAY...SMALL CRAFT ADVISORIES ARE
IN EFFECT AS A RESULT OF HAZARDOUS CONDITIONS FROM SQUARED SEAS
ACROSS ALL WATERS THROUGH THE WEEKEND. A LARGE WEST SWELL TRAIN
WILL MOVE THROUGH THE COASTAL WATERS SUNDAY AND MONDAY...PRODUCING
LOCALLY HAZARDOUS CONDITIONS FOR VESSELS WITHIN CLOSE PROXIMITY TO
THE SHORELINE.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...HIGH SURF ADVISORY...ENTIRE COAST FROM SONOMA COUNTY
SOUTH TO MONTEREY COUNTY
FLASH FLOOD WATCH...NORTH BAY COUNTIES
SCA...MRY BAY
SCA...PT ARENA TO PT REYES 0-10 NM
SCA...PT REYES TO PIGEON PT 0-10 NM
SCA...PIGEON PT TO PT PINOS 0-10 NM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM
SCA...PT ARENA TO PIGEON PT 10-60 NM
SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM
SCA...ROUGH BAR ADVISORY FOR SF BAR
SCA...SF BAY
&&
$$
PUBLIC FORECAST: DYKEMA
AVIATION: CANEPA
MARINE: CANEPA/DRP
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
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AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1000 AM EDT SUN MAR 13 2016
.DISCUSSION...
...A CHANCE OF LIGHTNING STORMS THIS AFTERNOON...
CONVECTIVE CLUSTER OVER THE NE GOMEX ASSOCD WITH A WEAK SHORT WAVE
IS BEING AIDED BY THE ASCENDING LEFT FRONT QUAD OF AN 80-89KT JET
MAX NOSING ACRS THE RIO GRANDE VALLEY. TOTAL LTG ACTIVITY HAS BEEN
RATHER SPARSE...HOWEVER...SUGGESTING THE CONVECTION IS STRUGGLING IN
A RATHER DRY AND HOSTILE SURROUNDING ENVIRONMENT. MOTION OF THE
COMPLEX PEGGED ARND 060/20KTS...WHICH WILL TAKE THE BULK OF IT WELL
N OF THE I-4 CORRIDOR.
MORNING RAOBS SHOW A NOTABLE INCREASE IN MOISTURE BLO H70 OVER THE
PAST 24HRS WITH PWAT VALUES BTWN 1.00"-1.25" ACRS CENTRAL/SRN FL...
INCREASING TO 1.50"-1.75" ACRS THE PANHANDLE. RAP ANALYSIS SHOWING
THE H100-H70 ANTICYCLONE OVER THE WRN ATLC RETREATING EWD AS THE
WEAK SHORT WAVE ADVANCES THRU THE ERN GOMEX. MOISTURE AHEAD OF THE
TROF IS SOMEWHAT LACKING WITH RAP ANALYSIS REVEALING A SLUG OF DRY
AIR OVER LAKE OKEECHOBEE WITH H100-H70 MEAN RH ARND 60PCT...
INCREASING TO ARND 75PCT N OF I-4.
MID LVL TEMP PROFILE REVEALS A MARGINALLY UNSTABLE AIRMASS ALOFT
WITH H70 TEMPS INCREASING FROM ARND 5C ALNG AND N OF THE I-4
CORRIDOR TO ARND 8C ALONG THE TREASURE COAST...H50 TEMPS BTWN
-9C/-10C AREAWIDE BUT WARMEST TO THE S. THE RESULTING H70-H50 LAPSE
RATES RANGE FROM 5.5-6.0C/KM ALONG AND N OF I-4 TO 6.5-7.0C/KM ALONG
THE TREASURE COAST. SHARP SUBSIDENCE INVERSION PERSISTS ARND H70
THAT WILL EFFECTIVELY CAP THE LCL AIRMASS BLO 10KFT FOR MUCH OF THE
DAY. HOWEVER...WITH NEAR FULL SUN...SFC HEATING WILL PUSH TEMPS INTO
THE L/M80S...WHICH ARE NEAR THE CONVECTIVE TRIGGERS AS INDICATED BY
THE KTBW/KXMR 12Z RAOBS.
WHILE MOISTURE MAY BE LACKING...THE AIRMASS IS SUFFICIENTLY PRIMED
FOR PRECIP ONCE CONVECTIVE TRIGGERS ARE REACHED. STRONGLY SUSPECT
THE GOMEX CONVECTION WILL NOT BE THE PRIMARY SOURCE FOR PRECIP THIS
AFTN...BUT RATHER MAY PROVIDE AN OUTFLOW BNDRY THAT WOULD AID IN
CONVECTIVE INITIATION. OVERALL TSRA STRENGTH WILL BE HAMPERED BY A
MARGINAL DYNAMIC PATTERN WITH LIMITED MID LVL VORTICITY/UPR LVL
DIVERGENCE. FURTHERMORE...EAST COAST SEA BREEZE FORMATION NOT
ANTICIPATED WITH 15-20KTS OF S/SW FLOW THRU 3KFT. EVEN SO...
ANTICIPATE A QUIET BUT WARM WX PATTERN THRU 2PM WITH INCREASING
SHRA/TSRA ACTIVITY THRU LATE AFTN...THEN CHOKING OFF AFT SUNSET
WITH THE LOSS OF DAYTIME HEATING.
OVERALL FCST LOOKS GOOD...MRNG UPDATES TO TUNE UP THE TIMING OF
PRECIP AND FOR INCREASING CLOUD COVER.
&&
.AVIATION...THRU 14/12Z
SFC WINDS: THRU 13/16Z...S/SW 5-9KTS. BTWN 13/16Z-13/24Z...S/SW 10-
14KTS WITH OCNL SFC G18-22KTS. BTWN 14/00Z-14/03Z...BCMG SW 4-7KTS.
VSBYS/WX/CIGS: THRU 13/16Z...VFR WITH OCNL CIGS ARND FL080 N OF KISM-
KTIX. BTWN 13/16Z-13/19Z...VFR WITH CIGS BTWN FL040-060...SLGT CHC
MVFR SHRAS W OF KLEE-KOBE. BTWN 13/19Z-14/01Z...NMRS MVFR SHRAS/SLGT
CHC IFR TSRAS. BTWN 14/01Z-14/08Z...VFR WITH CIGS AOA FL120. AFT
14/08Z...N OF KISM-KTIX AREAS MVFR BR/LCL LIFR FG...S OF KISM-KTIX
AREAS CIGS BTWN FL040-060.
&&
.MARINE...
GENTLE TO MODERATE S/SW BREEZE TODAY AS A HI PRES RIDGE OVR THE W
ATLC RETREATS EWD AHEAD OF A WEAK TROF ADVANCING ACRS THE ERN
GOMEX/FL PENINSULA. SEAS 2-3FT NEARSHORE AND 3-4FT OFFSHORE...MAINLY
IN SHORT PD WIND CHOP WITH DOMINANT PDS AOB 6SEC. SHRAS BCMG LIKELY
AFT 2PM WITH A SLIGHT CHANCE OF TSRAS MOVING OFFSHORE AROUND
20KTS...CONTG THRU SUNSET.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...BRAGAW
LONG TERM/IMPACT WX...LASCODY
AREA FORECAST DISCUSSION
NWS MIAMI FL
425 AM EDT SUN MAR 13 2016
.SYNOPSIS...
INCREASED MOISTURE AND A DISSIPATING LOW PRESSURE TROUGH WILL
BRING A FEW SHOWERS TO SOUTH FLORIDA THIS AND MONDAY AFTERNOONS.
THEREAFTER...HIGH PRESSURE RE-ESTABLISHES AND DRY AND WARM
CONDITIONS WILL PREVAIL.
&&
.SHORT TERM /TODAY THROUGH TUESDAY/...
SOUTHEAST WIND PREVAILS OVER SOUTH FLORIDA EARLY THIS MORNING AND
OVERNIGHT TEMPERATURES REMAIN WELL ABOVE NORMAL IN THE M/U60S AND
L70S. SYNOPTICALLY...CLOSED H5 LOPRES OVER MID-MS VLY CONTINUES
TO BROADEN AND WILL OPEN AND LIFT INTO NORTHEAST CONUS THROUGH
TONIGHT. ITS ATTENDANT SFC FEATURES ARE ALSO BECOMING MORE
DIFFUSE...AND CDFNT...FOR LACK OF BETTER WORD...HARD TO PINPOINT
OVER GA/AL. THIS LLVL BOUNDARY WILL MOVE SEWD TOWARD CENTRAL
FLORIDA TODAY BEFORE DISSIPATING. IT WILL PROVIDE A FORCE FOR
MOISTURE TO POOL AS ITS SPREAD NORTHWARD UP THE PENINSULA.
ADDITIONALLY...WITH EASTERLY FLOW MUCH WEAKER TODAY...SEA-BREEZES
WILL BUILD INLAND LATE MRNG/EARLY AFTN AS TEMPERATURES RISE INTO
L80S. DOES APPEAR THERE IS SUFFICIENT MOISTURE/INSTABILITY /SFC
DEWPOINT VALUES NEAR 70F/ FOR AT LEAST SOME SHOWERS TO DEVELOP
AROUND MIDDAY...WITH M/ULVL WINDS SPREADING THE ACTIVITY TWD NE
DURING THE AFTERNOON. BEST RAIN CHANCES ARE INLAND AREAS NORTH OF
ALLIGATOR ALLEY...PARTICULARLY INTERIOR PALM BEACH COUNTY...WHERE
A FEW THUNDERSTORMS CANT BE RULED OUT NEAR MAX
HEATING/CONVERGENCE. ACTIVITY SHOULD DIMINISH OVER THE
EVENING...MAKING FOR QUIET NIGHT.
SW FLOW WILL BE STRONGER MONDAY...AND AFOREMENTIONED TROUGH NEARLY
OUT OF THE PICTURE. OTHERWISE...SIMILAR ENVIRONMENT IN PLACE SO
THINK SCATTERED SHOWERS AGAIN POSSIBLE OVER NERN SECTIONS AS ATLC
BREEZE DEVELOPS. AGAIN...ISOLATED THUNDERSTORMS POSSIBLE MAINLY
OVER EASTERN HALF OF PALM BEACH COUNTY. WIND LESS TIME OF ONSHORE
FLOW ACRS EAST COAST...MAXIMA MAY RISE A COUPLE DEGREES WARMER
THAN THOSE OF THIS WEEKEND. CONVERSES...NAPLES AREA AND GULF COAST
MAXIMA WILL BE MODERATED BY RELATIVELY COOL GULF BREEZE IN
AFTERNOON.
DIURNAL ACTIVITY WILL PRECLUDE DRIER CONDITIONS FILTERING IN LATER
MONDAY EVENING...WITH NO RAIN CHANCES FOR TUESDAY. TEMPERATURES
BOOSTED A BIT HIGHER STILL TUESDAY AS SW FLOW PERSISTS AND CLOUDS
BECOME LESS.
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
QUIET AND WARM CONDITIONS EXPECTED THROUGH AT LEAST THURSDAY AS
HIGH PRESSURE DOMINATES. SFC RIDGE WILL BE NEARLY OVERHEAD
WEDNESDAY...THEN PUSHES EAST THURSDAY...ALLOWING ANTECEDENT SSW
FLOW TO BECOME SELY. THIS IN TURN WILL INCREASE MOISTURE/HUMIDITY
LEVELS HEADING INTO THE WEEKEND. NEXT STORM SYSTEM LOOKS POISED TO
APPROACH THE REGION AS EARLY AS SATURDAY...BRINGING AT LEAST A
CHANCE FOR SHOWERS.
&&
.AVIATION...
LIGHT SOUTHEAST WINDS CONTINUE TONIGHT OVER MOST OF SOUTH FLORIDA
TAF SITES...EXCEPT FOR KAPF TAF SITE WHERE THE WINDS WILL BE
VARIABLE BETWEEN 3 TO 5 KNOTS. THE WINDS WILL THEN INCREASE TO 10
TO 15 KNOTS WITH GUSTS TO 25 KNOTS AS THEY HAVE BEEN FOR THE LAST
SEVERAL DAYS. KAPF WILL HAVE A MORE SW DIRECTION AS A WEAK SURFACE
TROUGH MOVES THROUGH BUT THAT WILL LIKELY ONLY BE TEMPORARY.
SHOWERS WILL BEGIN TO DEVELOP LATE MORNING WITH THE APPROACH OF
THIS SYSTEM. FOR NOW HAVE VCSH STARTING AT 18Z AT ALL TERMINALS
BUT WILL NEED TO UPDATE FOR CURRENT RADAR TRENDS. SHOULD BE NOTED
THAT THE HRRR SHOWS A FEW SHOWERS BREAKING OUT AROUND 17Z IN THE
SOUTH FLORIDA INTERIOR. THERE COULD EVEN BE A THUNDERSTORM OR TWO
OVER ALL OF TAF SITES SUNDAY AFTERNOON...BUT AT THIS TIME THE
COVERAGE WILL BE FEW AND FAR BETWEEN TO PUT IT IN THE TAF SITES.
THE CEILING AND VIS WILL ALSO REMAIN RIGHT NEAR MVFR/VFR HEIGHTS
WITH A FEW SITES SHOWING 2500 FOOT DECKS. CONDITIONS COULD FALL
DOWN INTO MVFR CONDITIONS BETWEEN 10Z AND 13Z SUNDAY OVER KAPF TAF
SITE DUE TO FOG FORMATION. EXPECTED RAINFALL DOESNT APPEAR TO BE
TOO INTENSE...SO NOT REALLY EXPECTING MUCH VIS LOWERING FROM HEAVY
RAINFALL.
&&
.MARINE...
SE WIND 15 KT OR SO WILL PREVAIL TODAY...THEN TURN SW MONDAY AND
TUESDAY. THEN...LIGHTER WINDS ARE EXPECTED FOR THE REST OF THE
WEEK. A FEW SHOWERS...ESPECIALLY OVER LAKE OKEECHOBEE AND ATLC
WATERS OFF PALM BEACH COUNTY THIS AFTN AND AGAIN MON AFTN.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 84 69 84 68 / 40 20 30 10
FORT LAUDERDALE 83 71 84 70 / 30 10 20 0
MIAMI 83 72 84 69 / 30 10 10 0
NAPLES 82 68 82 67 / 10 0 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK THROUGH THIS EVENING FOR FLZ168-172-173.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...23/SK
LONG TERM....23/SK
AVIATION...99/ME
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
352 AM EDT SUN MAR 13 2016
.DISCUSSION...
...A CHANCE OF LIGHTNING STORMS THIS AFTERNOON...
TODAY...THE DEEP LAYER RIDGE WAS EAST OF THE FORECAST AREA AND WILL
KEEP MOVING AWAY FROM CENTRAL FLORIDA DURING THE DAY. THIS HAS
ALLOWED FOR A SHARP INCREASE IN THE AREA`S PRECIPITABLE WATER VALUES
FROM THE 0.94 INCHES PER THE 13/00Z CAPE CANAVERAL SOUNDING TO
AROUND 1.75 INCHES PER THE GFS FORECAST SOUNDING. THIS SHARP
INCREASE WAS SHOWN BY AN ALMOST VERTICAL INCREASE IN PRECIPITABLE
WATER BETWEEN 13/12Z AND 13/18Z WOULD SUPPORT LIKELY(60-70 POP)
SUGGESTED BY THE GFS MOS. TIME HEIGHT CROSS SECTIONS SHOW FAVORABLE
MID AND UPPER LEVEL DYNAMIC AND THERMODYNAMIC SUPPORT FEATURES...
VORTICITY ADVECTION/OMEGA VALUES/UPPER LEVEL DIVERGENCE AND 500MB
TEMPERATURES AROUND -10C...SHOULD SUPPORT ISOLATED/SLIGHT CHANCE OF
AFTERNOON STORMS. THE THICKENING CLOUD COVER MAY HOLD BACK
DAYTIME/LOWER LAYERS HEATING A COUPLE OF DEGREES LIMITING
INSTABILITY SO THE SLIGHT CHANCE/ISOLATED THUNDERSTORMS A GOOD CALL
FOR NOW. THE LOCAL HRRR MODEL HAS BEEN SHOWING A SOUTH SOUTHEAST/
ONSHORE WIND COMPONENT FROM AROUND VERO BEACH SOUTH IN THE
AFTERNOON. THE DAY SHIFT WILL HAVE TO WATCH TO SEE IF THIS "SEA
BREEZE" COMPONENT DOES DEVELOP AS IT MAY HAVE SOME CONTRIBUTION TO
THE STORMS ALONG THE COAST VERO BEACH SOUTH. THE SOUTHERLY WINDFLOW
WILL HELP PUSH AFTERNOON TEMPERATURES IN TO THE MID 80S.
TONIGHT...THE "MOISTURE BUMP" FROM THE AFTERNOON LINGERS THROUGH
MIDNIGHT BEFORE THE MOISTURE STARTS TO DECREASE. AT THE SAME TIME
THE MID AND UPPER LEVEL DYNAMIC SUPPORT FEATURES ARE MOVING AWAY
FROM CENTRAL FLORIDA. SHOWER POTENTIAL FALLS WEST TO EAST DURING THE
EVENING. SOUTHWESTERLY WINDS MOST/ALL OF THE NIGHT KEEP OVERNIGHT
LOWS IN THE MID AND UPPER 60S FOR ANOTHER NIGHT.
MONDAY...MID LVL SHORTWAVE TROUGH WILL MOVE EAST FROM TN TWD THE
APPALACHIANS THROUGH THE DAY WITH DEEP LAYER SW/WSW ACROSS CENTRAL
FL. A DRY SLOT WILL MOVE IN ACROSS THE NRN PENINSULA WITH WITH PWAT
VALUES DROPPING TO LESS THAN AN INCH ACROSS NRN SECTIONS IN THE
AFTERNOON. DEEPER MOISTURE WILL LINGER ACROSS SRN SECTIONS IN THE
MORNING INTO MID AFTERNOON AND WILL KEEP A 30 PCT CHANCE FOR SHOWERS
ACROSS THE SOUTH AND JUST A 20 PCT RAIN CHANCE FOR NRN AREAS. LOW
LVL SW/WSW FLOW TO AROUND 25 KNOTS AT 925 MBS SHOULD HOLD OFF THE
SEA BREEZE...EXCEPT FOR FAR SRN COASTAL SECTIONS. HIGHS SHOULD REACH
THE MID 80S.
TUE-THU...THE SHORTWAVE TROUGH WELL NORTH OF THE AREA WILL MOVE EAST
OFF THE MID ATLC COAST ON TUE WITH THE SFC RIDGE ACROSS FAR SRN FL
TUE/WED AND THEN SHIFTING OFFSHORE THU. A FLAT RIDGE ALOFT ACROSS
THE GULF WILL SHIFT EASTWARD OVER THE BAHAMAS THU...SETTING UP A
WARM AND DRY WEATHER PATTERN FOR MID WEEK. HIGHS ARE EXPECTED INTO
THE MID 80S FOR THE INTERIOR AND LOWER 80S ALONG THE IMMEDIATE COAST
WITH LOWS MAINLY IN THE 60S.
FRI-SUN...A FRONTAL BOUNDARY IS FORECAST TO STALL NEAR THE FL-GA
BORDER FRIDAY WITH INCREASING MOISTURE ACROSS THE NRN PENINSULA IN
THE AFTERNOON. EXPECT A CHANCE OF AFTERNOON CONVECTION MAINLY ACROSS
NRN SECTIONS CLOSER TO THE DEEPEST MOISTURE. A DEEPENING LONGWAVE
TROUGH WILL MOVE FROM THE N CENTRAL STATES SATURDAY TOWARD THE GREAT
LAKES SUNDAY AS THE SUB TROPICAL JET STRENGTHENS FROM THE YUCATAN TO
THE FL KEYS OVER THE WEEKEND. DIFFLUENT UPR FLOW AHEAD OF THE TROUGH
AND FORCED ASCENT BETWEEN THE NRN STREAM JET NEAR THE MID ATLC AND
UPPER JET ACROSS THE GULF WILL INCREASE RAIN CHANCES SATURDAY INTO
SUNDAY ACROSS THE AREA. WILL KEEP RAIN CHANCES IN THE SCATTERED
RANGE FOR NOW...30-40 PCT SATURDAY INCREASING TO NEAR 50 PCT
AREAWIDE SUNDAY. HAVE INTRODUCED SLIGHT THUNDER MENTION FOR SAT AFTN
AND SUNDAY WITH ADEQUATE INSTABILITY AND INCREASING DEEP LAYER LIFT
EXPECTED. CONVECTION AND CLOUD COVER SHOULD HOLD HIGH TEMPS A FEW
DEGS COOLER THAN MID WEEK BUT STILL INTO THE LOWER 80S MUCH OF THE
AREA.
&&
.AVIATION...VFR CONDITIONS WITH CONSIDERABLY HIGH CLOUDINESS AND FEW-
SCATTERED LOW CLOUDS THROUGH 13/15Z IN THE MOIST SOUTHERLY FLOW.
PREVAILING MVFR CEILINGS AFTER 13/15ZS. SOUTH TO SOUTHWEST WINDS AT
15 KNOTS GUSTING TO 20 TO 25 KNOTS IN THE AFTERNOON. VCSH THROUGH
THE AFTERNOON ARE OVERHEAD.
&&
.MARINE...
TODAY..SOUTHEAST TO SOUTH WINDS 10 TO 15 KNOTS AS THE WESTERN EDGE
OF HIGH PRESSURE PULLS AWAY FROM FLORIDA. SEAS 3 FT NEAR SHORE AND
4 FT GULF STREAM/OFFSHORE. A SLIGHT CHANCE OF SHOWERS IN THE MORNING
THEN SHOWERS LIKELY WITH ISOLATED STORMS IN THE AFTERNOON. SHOWERS
AND STORMS SHOULD MOVE SOUTHWEST TO NORTHEAST AT AROUND 20 MPH.
TONIGHT...SHOWERS LINGER OVER THE COASTAL WATERS MOST OF THE NIGHT.
SOUTHWEST WINDS 10 TO 15 KNOTS NEARSHORE AND 15 KNOTS OFFSHORE. SEAS
2 TO 3 FEET NEARSHORE AND 3 FEET OFFSHORE.
SW WINDS TO 15-18 KNOTS OFFSHORE MONDAY WILL ELEVATE SEAS TO 3-4 FT
WELL OFFSHORE. SW WINDS SHOULD DROP A BIT TO 10-15 KNOTS TUE AND TO
10 KNOTS OR LESS WED WITH SEAS DECREASING TO 2-3 FT. SW WINDS WILL
INCREASE TO 10-15 KNOTS THU BUT SEAS WILL STILL AVERAGE 2-3 FT. A
CHANCE OF SHOWERS IS EXPECTED MAINLY SOUTH OF SEBASTIAN INLET ON
MONDAY AND THEN DRY WEATHER IS FORECAST FOR MID WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 83 66 85 62 / 70 20 20 0
MCO 85 69 87 64 / 70 20 20 10
MLB 84 69 85 61 / 70 30 30 10
VRB 85 67 85 61 / 70 30 30 10
LEE 83 68 86 63 / 70 20 20 10
SFB 84 68 86 63 / 70 20 20 10
ORL 84 68 87 64 / 70 20 20 10
FPR 84 69 85 60 / 70 30 30 10
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...WIMMER
LONG TERM....VOLKMER
AREA FORECAST DISCUSSION
NWS MIAMI FL
1236 AM EST SUN MAR 13 2016
.AVIATION...
LIGHT SOUTHEAST WINDS CONTINUE TONIGHT OVER MOST OF SOUTH FLORIDA
TAF SITES...EXCEPT FOR KAPF TAF SITE WHERE THE WINDS WILL BE
VARIABLE BETWEEN 3 TO 5 KNOTS. THE WINDS WILL THEN INCREASE TO 10
TO 15 KNOTS WITH GUSTS TO 25 KNOTS AS THEY HAVE BEEN FOR THE LAST
SEVERAL DAYS. KAPF WILL HAVE A MORE SW DIRECTION AS A WEAK SURFACE
TROUGH MOVES THROUGH BUT THAT WILL LIKELY ONLY BE TEMPORARY.
SHOWERS WILL BEGIN TO DEVELOP LATE MORNING WITH THE APPROACH OF
THIS SYSTEM. FOR NOW HAVE VCSH STARTING AT 18Z AT ALL TERMINALS
BUT WILL NEED TO UPDATE FOR CURRENT RADAR TRENDS. SHOULD BE NOTED
THAT THE HRRR SHOWS A FEW SHOWERS BREAKING OUT AROUND 17Z IN THE
SOUTH FLORIDA INTERIOR. THERE COULD EVEN BE A THUNDERSTORM OR TWO
OVER ALL OF TAF SITES SUNDAY AFTERNOON...BUT AT THIS TIME THE
COVERAGE WILL BE FEW AND FAR BETWEEN TO PUT IT IN THE TAF SITES.
THE CEILING AND VIS WILL ALSO REMAIN RIGHT NEAR MVFR/VFR HEIGHTS
WITH A FEW SITES SHOWING 2500 FOOT DECKS. CONDITIONS COULD FALL
DOWN INTO MVFR CONDITIONS BETWEEN 10Z AND 13Z SUNDAY OVER KAPF TAF
SITE DUE TO FOG FORMATION. EXPECTED RAINFALL DOESNT APPEAR TO BE
TOO INTENSE...SO NOT REALLY EXPECTING MUCH VIS LOWERING FROM HEAVY
RAINFALL.
&&
.PREV DISCUSSION... /ISSUED 713 PM EST SAT MAR 12 2016/
..HIGH RIP CURRENT RISK CONTINUES ALONG THE ATLANTIC BEACHES
THROUGH SUNDAY...
UPDATE...
GENERALLY DRY CONDITIONS CONTINUE TO PREVAIL ACROSS SOUTH FLORIDA
THIS EVENING. HAVE ADDED PATCHY FOG OVER MUCH OF SOUTHWEST FLORIDA
FOR THE OVERNIGHT INTO MORNING HOURS. NAPLES OBSERVED SOME MORNING
FOG EARLIER TODAY AND CONDITIONS TONIGHT WITH ADDITIONAL SURFACE
MOISTURE AND A DECOUPLING OF THE WINDS AFTER SUNSET SHOULD ALLOW
FOR A FOG POTENTIAL OVERNIGHT AGAIN. UPDATED ZONES AND FWF WILL BE
ISSUED SHORTLY.
PREV DISCUSSION... /ISSUED 403 PM EST SAT MAR 12 2016/
DISCUSSION...
A FRONTAL BOUNDARY APPROACHES THE REGION FROM THE WEST OVER THE
COMING DAY OR SO. THE PARENT MID-LEVEL LOW PRESSURE SYSTEM SITTING
OVER TEXAS AT THE MOMENT WILL WEAKEN INTO A TROUGH AS IT SHIFTS
NORTHEAST INTO THE MISSISSIPPI AND OHIO RIVER VALLEYS BY THE END
OF THE WEEKEND. THE TROUGH, ALONG WITH INCREASED MOISTURE RETURN
OVER FLORIDA AHEAD OF THE SURFACE FRONT, COULD PRODUCE SHOWERS ON
STARTING TONIGHT ACROSS PORTIONS OF SOUTH FLORIDA THROUGH LATE
MONDAY.
A SLIGHT CHANCE OF THUNDERSTORMS IS MENTIONED IN THE FORECAST FOR
SUNDAY AND MONDAY. ON SUNDAY, THE FRONTAL INFLUENCE ON THE REGION
COMBINES WITH AVAILABLE MOISTURE AND DIURNAL HEATING, WITH
AFTERNOON MAXIMUM TEMPERATURES REACHING INTO THE 80S, TO CREATE AT
LEAST A MENTIONABLE POTENTIAL FOR A THUNDERSTORM OR TWO. ON
MONDAY, AN UPPER LEVEL JET WILL PUSH INTO THE SR 80 CORRIDOR
INCLUDING LAKE OKEECHOBEE DURING THE AFTERNOON AND EVENING HOURS
WHICH COULD ALLOW ANY CONVECTION AN OPPORTUNITY TO DEVELOP INTO A
THUNDERSTORM WITH THE ENHANCED UPPER LEVEL SUPPORT. OVERALL, MOST
CONVECTION SHOULD REMAIN SHOWERS.
AS THE MID-LEVEL TROUGH AND SURFACE BOUNDARY EXIT THE REGION LATE
MONDAY NIGHT INTO TUESDAY MORNING, CONDITIONS WILL BECOME DRIER
FOR THE MIDDLE OF THE WEEK. THE NEXT FRONTAL SYSTEM WILL BEGIN TO
DEVELOP BY THURSDAY AND PUSH EAST INTO THE REGION THURSDAY NIGHT
INTO FRIDAY. THE BOUNDARY COULD POTENTIALLY STALL OVER FLORIDA
ENTERING NEXT WEEKEND. THERE ARE SOME DIFFERENCES ON LOCATIONS OF
SYNOPTIC FEATURES IN THE EXTENDED MODEL GUIDANCE, BUT THE GENERAL
TREND IS A WETTER FORECAST FOR NEXT WEEKEND AT THIS POINT IN TIME.
THE 12Z GFS BRINGS THE BOUNDARY INTO CENTRAL FLORIDA WHILE THE
ECMWF KEEPS THE BOUNDARY OVER THE INTERSTATE 10 CORRIDOR IN NORTH
FLORIDA LATE FRIDAY INTO SATURDAY. THE MAJOR DIFFERENCES IN THE
SOLUTIONS ARE THE TIMING AND EXTENT THAT AN EAST COAST TROUGH DIGS
SOUTH.
TEMPERATURES THROUGH THE PERIOD SHOULD REMAIN WARM WITH SPRING
GRADUALLY FORESHADOWING THE APPROACH OF SUMMER. WHILE THE RAINY
SEASON IS STILL NOT ON THE IMMEDIATE HORIZON, THE NEXT WEEK
CURRENTLY APPEARS TO BE SLIGHTLY MORE MOIST THAN THE PREVIOUS
WEEK. RAIN CHANCES ARE STILL NOT HIGH ENOUGH TO BE CONFIDENT THAT
MOST LAWNS WILL SEE RAIN THIS WEEK, BUT AT LEAST EVERYONE WILL
HAVE A CHANCE OF SEEING A SHOWER OR TWO THIS WEEK. 02/RAG
MARINE...
GUSTY WINDS OVER THE GULF STREAM CONTINUES TO CREATE SCEC
CONDITIONS. WINDS HAVE BECOME LIGHTER OVER MUCH OF THE REST OF THE
WATERS. AS THE FRONT APPROACHES AND EVENTUALLY PASSES, SOME GUSTY
EASTERLY WINDS COULD AGAIN RETURN TO THE WATERS. 02/RAG
FIRE WEATHER...
THOSE WITH FIRE WEATHER INTERESTS ACROSS SOUTH FLORIDA SHOULD
MONITOR THE EVOLUTION OF THE FORECAST AS THE WEEK CONTINUES. THE
LACK OF RECENT WETTING RAINS HAS ALLOWED ERC VALUES TO RISE TO
AROUND 30 IN MOST COUNTIES. AFTER THIS NEXT FRONTAL SYSTEM EXITS,
DRIER AIR WILL ENTER THE REGION BRINGING THE POTENTIAL OF CRITICAL
RELATIVE HUMIDITY DURATIONS DURING THE AFTERNOONS MID-WEEK. 02/RAG
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 84 68 85 67 / 40 20 30 10
FORT LAUDERDALE 83 71 85 69 / 40 20 20 0
MIAMI 84 71 85 70 / 40 20 20 0
NAPLES 82 68 81 67 / 20 20 20 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK THROUGH THIS EVENING FOR FLZ168-172-173.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...
LONG TERM....
AVIATION...
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1055 PM EDT MON MAR 14 2016
.SYNOPSIS...
A PRESSURE TROUGH IN THE WESTERN PORTION OF THE FORECAST AREA
THIS EVENING WILL SHIFT EAST OF THE AREA OVERNIGHT. RIDGING WILL
EXTEND ALONG THE GULF COAST THROUGH WEDNESDAY. A COLD FRONT WITH
LITTLE MOISTURE WILL MOVE INTO THE FORECAST AREA WEDNESDAY AND
STALL. INCREASED MOISTURE WILL OCCUR OVER THE WEEKEND WITH LOW
PRESSURE MOVING INTO THE REGION.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
UPPER-LEVEL TROUGH CROSSING THE TN VALLEY WILL MOVE INTO THE
FORECAST AREA THIS EVENING. STRONGEST ACTIVITY CURRENTLY IN THE
NORTHERN MIDLANDS...MAINLY NORTH OF CAE. LATEST HRRR INDICATING
CONVECTION PERSISTING INTO THE LATE EVENING...WEAKENING BY LATE
EVENING WITH LOSS OF DAY TIME HEATING. INSTABILITY PARAMETERS
REMAIN MODERATE FOR MUCH OF THE MIDLANDS. BEST TIMING WILL BE
MAINLY THROUGH 03Z-04Z WITH MAIN THREATS BEING LARGE HAIL AND
DAMAGING WIND GUSTS AS PRIMARY THREATS.
PARTLY CLOUDY OVERNIGHT WITH PATCHY FOG POSSIBLE TOWARDS DAWN.
OVERNIGHT LOWS GENERALLY IN THE MIDDLE TO UPPER 50S.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY/...
DRY WEATHER IS FORECAST TUESDAY THROUGH WEDNESDAY. THE MODELS
DISPLAY FLAT UPPER RIDGING OVER THE REGION WITH SURFACE HIGH
PRESSURE EXTENDING FROM THE ATLANTIC INTO THE GULF OF MEXICO
TUESDAY. THE MODELS DISPLAY A DRY COLD FRONT MOVING INTO THE AREA
AND STALLING WEDNESDAY. WE SHOULD CONTINUE TO SEE MUCH ABOVE
NORMAL TEMPERATURES. USED THE GUIDANCE CONSENSUS FOR THE
TEMPERATURE FORECAST.
THE RECORD HIGH TEMPERATURE FOR CAE
MARCH 15: 88F SET IN 1977
MARCH 16: 88F SET IN 1921
THE RECORD HIGH TEMPERATURE FOR AGS
MARCH 15: 86F SET IN 1977
MARCH 16: 88F SET IN 1921
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
THE GFS AND ECMWF DISPLAYED A FRONT STALLED NEAR FORECAST AREA
WEDNESDAY NIGHT AND THURSDAY. THE GFS INDICATED MORE OF A MOISTURE
INCREASE IN THE AREA COMPARED TO THE GFS. BOTH MODELS HAD MOISTURE
SUPPRESSED SOUTH OF THE AREA FRIDAY BUT FORECAST CONFIDENCE IS LOW
BECAUSE OF A TIGHT MOISTURE GRADIENT NEAR THE AREA. BOTH MODELS
DISPLAYED DEEP MOISTURE SATURDAY AND SATURDAY NIGHT ASSOCIATED
WITH LOW PRESSURE MOVING INTO THE REGION. IT MAY BE DRY SUNDAY
WITH THE SYSTEM LIFTING NORTH OF THE AREA. FORECAST CONFIDENCE IS
LOW BECAUSE OF LITTLE RUN-TO-RUN MODEL CONSISTENCY.
&&
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
VFR CONDITIONS GENERALLY EXPECTED DURING THE TAF PERIOD.
AN UPPER LEVEL TROUGH WILL CONTINUE TO LIFT NORTHEAST ALONG THE
MID-ATLANTIC OVERNIGHT. THE THREAT OF SHOWERS HAS MOVED NORTH AND
EAST OF ALL TAF SITES.
PATCHY FOG IS POSSIBLE OVERNIGHT HOWEVER A 30 TO 40 LLJ WILL
PROMOTE MIXING AND LIMIT FOG FORMATION. AT THIS TIME HAVE ONLY
INCLUDED MVFR FOG AT AGS. SURFACE WINDS WILL BE OUT OF THE SW
OVERNIGHT AROUND 5 KTS VEERING TO W/WSW BY TOMORROW MORNING.
HIGH CONFIDENCE IN VFR CONDITIONS ON TUESDAY AS SURFACE HIGH
PRESSURE MOVES INTO THE REGION. W/WSW WINDS ARE EXPECTED TUESDAY
WITH SPEEDS FROM 5 TO 10 KTS.
EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS TO AVIATION
EXPECTED TUESDAY THROUGH SATURDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
814 PM EDT MON MAR 14 2016
.SYNOPSIS...
A PRESSURE TROUGH IN THE WESTERN PORTION OF THE FORECAST AREA
THIS EVENING WILL SHIFT EAST OF THE AREA OVERNIGHT. RIDGING WILL
EXTEND ALONG THE GULF COAST THROUGH WEDNESDAY. A COLD FRONT WITH
LITTLE MOISTURE WILL MOVE INTO THE FORECAST AREA WEDNESDAY AND
STALL. INCREASED MOISTURE WILL OCCUR OVER THE WEEKEND WITH LOW
PRESSURE MOVING INTO THE REGION.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
UPPER-LEVEL TROUGH CROSSING THE TN VALLEY WILL MOVE INTO THE
FORECAST AREA THIS EVENING. STRONGEST ACTIVITY CURRENTLY IN THE
NORTHERN MIDLANDS...MAINLY NORTH OF CAE. LATEST HRRR INDICATING
CONVECTION PERSISTING INTO THE LATE EVENING...WEAKENING BY LATE
EVENING WITH LOSS OF DAY TIME HEATING. INSTABILITY PARAMETERS
REMAIN MODERATE FOR MUCH OF THE MIDLANDS. BEST TIMING WILL BE
MAINLY THROUGH 03Z-04Z WITH MAIN THREATS BEING LARGE HAIL AND
DAMAGING WIND GUSTS AS PRIMARY THREATS.
PARTLY CLOUDY OVERNIGHT WITH PATCHY FOG POSSIBLE TOWARDS DAWN.
OVERNIGHT LOWS GENERALLY IN THE MIDDLE TO UPPER 50S.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY/...
DRY WEATHER IS FORECAST TUESDAY THROUGH WEDNESDAY. THE MODELS
DISPLAY FLAT UPPER RIDGING OVER THE REGION WITH SURFACE HIGH
PRESSURE EXTENDING FROM THE ATLANTIC INTO THE GULF OF MEXICO
TUESDAY. THE MODELS DISPLAY A DRY COLD FRONT MOVING INTO THE AREA
AND STALLING WEDNESDAY. WE SHOULD CONTINUE TO SEE MUCH ABOVE
NORMAL TEMPERATURES. USED THE GUIDANCE CONSENSUS FOR THE
TEMPERATURE FORECAST.
THE RECORD HIGH TEMPERATURE FOR CAE
MARCH 15: 88F SET IN 1977
MARCH 16: 88F SET IN 1921
THE RECORD HIGH TEMPERATURE FOR AGS
MARCH 15: 86F SET IN 1977
MARCH 16: 88F SET IN 1921
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
THE GFS AND ECMWF DISPLAYED A FRONT STALLED NEAR FORECAST AREA
WEDNESDAY NIGHT AND THURSDAY. THE GFS INDICATED MORE OF A MOISTURE
INCREASE IN THE AREA COMPARED TO THE GFS. BOTH MODELS HAD MOISTURE
SUPPRESSED SOUTH OF THE AREA FRIDAY BUT FORECAST CONFIDENCE IS LOW
BECAUSE OF A TIGHT MOISTURE GRADIENT NEAR THE AREA. BOTH MODELS
DISPLAYED DEEP MOISTURE SATURDAY AND SATURDAY NIGHT ASSOCIATED
WITH LOW PRESSURE MOVING INTO THE REGION. IT MAY BE DRY SUNDAY
WITH THE SYSTEM LIFTING NORTH OF THE AREA. FORECAST CONFIDENCE IS
LOW BECAUSE OF LITTLE RUN-TO-RUN MODEL CONSISTENCY.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
VFR CONDITIONS GENERALLY EXPECTED DURING THE TAF PERIOD.
AN UPPER LEVEL TROUGH WILL LIFT NORTHEASTWARD OVER THE
APPALACHIANS THIS EVENING. ISOLATED SHOWERS HAVE DEVELOPED IN THE
CSRA AND WESTERN MIDLANDS. RAIN SHOWERS WILL BE POSSIBLE AT
AGS/DNL AND CAE/CUB THROUGH 02Z. THUNDERSTORM ACTIVITY HAS
REMAINED NORTH OF ALL TAF SITES WHERE UPPER LEVEL SUPPORT IS MORE
FAVORABLE.
PATCHY FOG IS POSSIBLE OVERNIGHT HOWEVER A 30 TO 40 LLJ WILL
PROMOTE MIXING AND LIMIT FOG FORMATION. AT THIS TIME HAVE ONLY
INCLUDED MVFR FOG AT AGS. SURFACE WINDS WILL BE OUT OF THE SW
OVERNIGHT AROUND 5 KTS VEERING TO W/WSW BY TOMORROW MORNING.
HIGH CONFIDENCE IN VFR CONDITIONS ON TUESDAY AS SURFACE HIGH
PRESSURE MOVES INTO THE REGION. W/WSW WINDS ARE EXPECTED TUESDAY
WITH SPEEDS FROM 5 TO 10 KTS.
EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS TO AVIATION
EXPECTED TUESDAY THROUGH SATURDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
235 PM EDT SUN MAR 13 2016
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
FIRST PART OF SHORT TERM CHARACTERIZED BY WEAK IMPULSE PUSHING NEWD
AND A MORE DESTABILIZING ENVIRONMENT ALONG AND SOUTH OF A COLUMBUS
TO ATHENS LINE WHERE SOLAR SHELTERING ALONG THE EDGE OF SOME
ENHANCED CLOUD COVER IN THE MORNING HAS RESULTED IN A THERMAL
GRADIENT. THIS SHOULD HELP FOCUS ANY FURTHER CONVECTIVE INITIATION
FOR LATE AFTERNOON/EARLY EVENING. RAP GUIDANCE AND LATEST TRENDS
SUPPORT 500-1000 J/KG MLCAPE FOR SOUTHEAST TIER SO COULD HAVE SOME
ISOLATED THUNDER BUT NOT EXPECTING MUCH BEYOND GENERAL THREAT.
SHOULD HAVE LULL IN ANY PRECIP OVERNIGHT IN WAKE OF AFOREMENTIONED
DISTURBANCE...WITH SOME AREAS OF FOG POSSIBLE GIVEN THE
MOIST/TROPICAL ENVIRONMENT...LIGHT WINDS...AND PROGGED 975MB RH
FIELD SHOWING GOOD SATURATION. WILL NEED TO WATCH FOR POTENTIAL OF
GREATER COVERAGE IF WE GET SOME LOCATIONS OF CLEARING NEAR MIDNIGHT.
OTHERWISE MONDAY WILL HAVE A QUICK MOVING UPPER SHORTWAVE TRAVERSING
THE TENNESSEE VALLEY AND BRINGING ANOTHER ROUND OF PRECIP POTENTIAL
MAINLY TO NORTH GA WITH GREATEST CHANCE IN AFTERNOON. THE TIMING
WITH DAYTIME HEATING AND PROGGED INSTABILITY ALONG WITH DECENT LOW
LEVEL LAPSE RATES WILL BRING A SLIGHTLY GREATER CHANCE FOR THUNDER
AND PERHAPS A HAIL THREAT WITH ANY STRONGER DEVELOPMENT. NOT
EXPECTING SEVERE BUT SOME STRONG STORMS ARE POSSIBLE. FCST QPF SPITS
OUT UPWARDS OF A QUICK QUARTER INCH FOR THE NORTHERN TIER WHICH
SEEMS REASONABLE...THOUGH ISOLATED HIGHER AMOUNTS POSSIBLE WITH
STRONGER STORMS.
TEMPS CONTINUE TO BE ABNORMALLY HIGH WITH VALUES AT 10-15 DEGREES
ABOVE CLIMO. DAYTIME HIGHS TOMORROW MAY BE MORE LIMITED FROM ANY
PRECIP/ENHANCED CLOUD COVERAGE FROM AFOREMENTIONED SHORTWAVE.
BAKER
.LONG TERM /TUESDAY THROUGH SUNDAY/...
NO MAJOR CHANGES WERE MADE TO THE EXTENDED PERIODS AS LONG RANGE
MODELS CONTINUE TO SHOW A QUIET PERIOD ON TUESDAY... BEFORE
SAGGING A WEAK FRONTAL BOUNDARY INTO THE AREA ON WEDNESDAY. MODELS
SHOW AN UPPER DISTURBANCE DEVELOPING LOW PRESSURE WAVE ALONG THE
FRONT WEDNESDAY NIGHT AND THURSDAY... JUST STILL MUCH UNCERTAINTY
JUST WHERE THIS FOCUS WILL BE. LATEST MODELS ARE HINTING AT THE
GREATER RAIN CHANCES BEING OVER CENTRAL GA... BUT WILL CONTINUE TO
HOLD ONTO POPS ACROSS NORTH GA AS WELL. THE MODELS CONTINUE TO
SHOW A WET PATTERN GOING INTO THE WEEKEND... WARRANTING CHANCE
POPS AND A SLIGHT CHANCE OF THUNDER AT LEAST ON SATURDAY. STAY
TUNED. 39
PREV LONG TERM DISCUSSION.../ISSUED 410 AM EDT SUN MAR 13 2016/
LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
RIDGING SHOULD DOMINATE THE FORECAST AREA MONDAY NIGHT INTO
TUESDAY IN THE WAKE OF THE EXITING TN VALLEY SHORT WAVE. STRONG
LOW PRESSURE MOVING ALONG THE GREAT LAKES SHOULD PUSH A FRONTAL
BOUNDARY INTO THE APPALACHIANS ON WEDNESDAY. MOISTURE LOOKS
LIMITED WITH THIS...BUT MODELS WANT TO DEVELOP A WAVE ON THE FRONT
AS IT DRIFTS INTO CENTRAL GA BY THURSDAY. LOW POPS LOOK OKAY FOR
WEDNESDAY AND THURSDAY...WITH SOME DRYING ACROSS THE NORTH BY
THURSDAY NIGHT. MOISTURE RETURNS FRIDAY AND SATURDAY AS IT LOOKS
LIKE THE BOUNDARY BEGINS TO PUSH BACK TO THE NORTH. THIS IS NOT AS
CLEAR CUT...HOWEVER CHANCE POPS FOR FRIDAY AND SATURDAY STILL LOOK
OKAY. TEMPERATURES REMAIN WARM BUT SOME COOLING IS NOTED TOWARD
THE END OF THE PERIOD.
41
&&
.AVIATION...
/ISSUED AT 147 PM EDT SUN MAR 13 2016/
18Z UPDATE...
CIGS IMPROVED TO VFR IN 4-5 KFT LEVEL FOR AFTERNOON THOUGH SOME
ISOLATED SHOWERS ARE REDEVELOPING WITH ANOTHER WEAK WAVE AND SOME
SOLAR HEATING. THINKING BEST CHANCE FOR ANY -TSRA WILL BE NEAR
KMCN OTHERWISE HAVE CARRIED VCSH ELSEWHERE UNTIL NEAR 00Z. COULD
HAVE SOME CLEARING OVERNIGHT OR STAY FEW/SCT IN MIDLEVELS...THOUGH
GOOD CHANCE OF MVFR CIGS RETURNING AFTER ABOUT 09Z AND SOME MVFR
VSBY POTENTIAL. CIGS LIFT/SCATTER AGAIN MONDAY AFTERNOON BUT
COVERAGE STAYING GREATER FOR NORTHERN SITES WITH INFLUENCE OF
ANOTHER SHORTWAVE DISTURBANCE. COULD HAVE -SHRA AS FAR SOUTH AS
KATL IN 17-23Z PERIOD AND CANNOT RULE OUT ISOLATED THUNDER AS
WELL. WINDS OVERALL SW WITH SOME LOW END GUSTS BOTH AFTERNOONS AND
LIGHT SSW OVERNIGHT. WILL NEED TO WATCH FOR POTENTIAL AREAS OF FOG
IN THE EARLY MORNING AS WELL.
//ATL CONFIDENCE...18Z UPDATE...
MEDIUM ON OVERNIGHT CIG TIMING.
HIGH ON ALL ELSE.
BAKER
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 55 77 53 83 / 20 30 10 0
ATLANTA 57 75 55 82 / 10 30 10 0
BLAIRSVILLE 51 69 49 78 / 20 40 20 0
CARTERSVILLE 54 73 51 82 / 10 30 10 0
COLUMBUS 57 79 56 84 / 5 20 5 0
GAINESVILLE 54 72 53 80 / 20 30 10 0
MACON 57 79 55 84 / 20 10 5 0
ROME 54 74 50 82 / 20 40 10 0
PEACHTREE CITY 53 75 51 82 / 10 30 5 0
VIDALIA 61 83 59 85 / 30 10 5 0
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BAKER
LONG TERM....39
AVIATION...BAKER
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
147 PM EDT SUN MAR 13 2016
.PREV DISCUSSION... /ISSUED 1052 AM EDT SUN MAR 13 2016/
.UPDATE...
OVERALL TREND WITH FIRST WEAK UPPER WAVE HAS BEEN DIMINISHING
SHOWERS TO THE NORTHEAST AND HI-RES SOLUTIONS ARE ONLY SHOWING
SOME ISOLATED TO MAYBE SCATTERED DEVELOPMENT AT BEST ACROSS
PORTIONS OF CENTRAL GA THIS AFTERNOON WHEN ANOTHER WEAK WAVE COULD
ALLOW FOR SOME REDEVELOPMENT. WHAT MAY ACTUALLY BETTER FOCUS ANY
CONVECTIVE INITIATION WOULD BE IF A THERMAL GRADIENT SETS UP FROM
SOLAR SHELTERING ALONG AN ENHANCED CLOUD COVERAGE AREA MAINLY EAST
OF A COLUMBUS TO ATHENS LINE /PER RECENT VIS SAT OBS/. RAP MLCAPE
IS PROGGED TO REACH IN 500-1000 J/KG RANGE MAXIMIZED IN EAST
CENTRAL GA BY AFTERNOON SO FEEL THIS IS BEST CHANCE AT ANY
THUNDERSTORMS THOUGH NOT ANTICIPATING ANY ACTIVITY TO BE INTENSE
/CANNOT RULE OUT A FEW STRONG HOWEVER/. OTHERWISE MADE MINOR
ADJUSTMENTS TO OTHER FCST TRENDS AND PREVIOUS DISCUSSION
FOLLOWS...
BAKER
&&
PREV DISCUSSION... /ISSUED 747 AM EDT SUN MAR 13 2016/
.SHORT TERM /TODAY THROUGH MONDAY/...
INITIAL SHORT WAVE LIFTING NORTH OUT OF EAST TEXAS INTO THE MID-
MISSISSIPPI VALLEY THIS MORNING. MODELS CONTINUE TO INDICATE THIS
INITIAL WAVE WILL CONTINUE TO WEAKEN AS THE NEXT SHORT WAVE DIGS
INTO THE SOUTHERN PLAINS. HAVE NOT SEEN ANY SIGNIFICANT LIGHTNING
ACTIVITY NEARBY WITH THIS SYSTEM OVERNIGHT...HOWEVER MARGINAL
INSTABILITY AVAILABLE FOR A SLIGHT CHANCE THIS MORNING AND A
CHANCE THIS AFTERNOON. MID-LEVEL LAPSE RATES VERY WEAK AND
DYNAMICS ARE LACKING A BIT AS WELL SO STRONG TO SEVERE
THUNDERSTORMS ARE NOT EXPECTED. A BIT OF A BREAK TONIGHT AS THE
FIRST SYSTEM EXITS AND THE NEXT APPROACHES. COMPACT BUT FAIRLY
STRONG WAVE SWEEPS THROUGH THE TENNESSEE VALLEY MONDAY. MID-LEVEL
LAPSE RATES...AND SUBSEQUENTLY INSTABILITY...ARE A BIT HIGHER WITH
THIS NEXT SYSTEM. ALTHOUGH CHANCES FOR SEVERE THUNDERSTORMS ARE
NOT GREAT...CANNOT RULE OUT A FEW STRONG STORMS ACROSS NORTH
GEORGIA MONDAY.
20
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
RIDGING SHOULD DOMINATE THE FORECAST AREA MONDAY NIGHT INTO
TUESDAY IN THE WAKE OF THE EXITING TN VALLEY SHORT WAVE. STRONG
LOW PRESSURE MOVING ALONG THE GREAT LAKES SHOULD PUSH A FRONTAL
BOUNDARY INTO THE APPALACHIANS ON WEDNESDAY. MOISTURE LOOKS
LIMITED WITH THIS...BUT MODELS WANT TO DEVELOP A WAVE ON THE FRONT
AS IT DRIFTS INTO CENTRAL GA BY THURSDAY. LOW POPS LOOK OKAY FOR
WEDNESDAY AND THURSDAY...WITH SOME DRYING ACROSS THE NORTH BY
THURSDAY NIGHT. MOISTURE RETURNS FRIDAY AND SATURDAY AS IT LOOKS
LIKE THE BOUNDARY BEGINS TO PUSH BACK TO THE NORTH. THIS IS NOT AS
CLEAR CUT...HOWEVER CHANCE POPS FOR FRIDAY AND SATURDAY STILL LOOK
OKAY. TEMPERATURES REMAIN WARM BUT SOME COOLING IS NOTED TOWARD
THE END OF THE PERIOD.
41
&&
.AVIATION...
18Z UPDATE...
CIGS IMPROVED TO VFR IN 4-5 KFT LEVEL FOR AFTERNOON THOUGH SOME
ISOLATED SHOWERS ARE REDEVELOPING WITH ANOTHER WEAK WAVE AND SOME
SOLAR HEATING. THINKING BEST CHANCE FOR ANY -TSRA WILL BE NEAR
KMCN OTHERWISE HAVE CARRIED VCSH ELSEWHERE UNTIL NEAR 00Z. COULD
HAVE SOME CLEARING OVERNIGHT OR STAY FEW/SCT IN MIDLEVELS...THOUGH
GOOD CHANCE OF MVFR CIGS RETURNING AFTER ABOUT 09Z AND SOME MVFR
VSBY POTENTIAL. CIGS LIFT/SCATTER AGAIN MONDAY AFTERNOON BUT
COVERAGE STAYING GREATER FOR NORTHERN SITES WITH INFLUENCE OF
ANOTHER SHORTWAVE DISTURBANCE. COULD HAVE -SHRA AS FAR SOUTH AS
KATL IN 17-23Z PERIOD AND CANNOT RULE OUT ISOLATED THUNDER AS
WELL. WINDS OVERALL SW WITH SOME LOW END GUSTS BOTH AFTERNOONS AND
LIGHT SSW OVERNIGHT. WILL NEED TO WATCH FOR POTENTIAL AREAS OF FOG
IN THE EARLY MORNING AS WELL.
//ATL CONFIDENCE...18Z UPDATE...
MEDIUM ON OVERNIGHT CIG TIMING.
HIGH ON ALL ELSE.
BAKER
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 74 56 77 53 / 50 20 30 10
ATLANTA 74 58 75 55 / 40 10 30 10
BLAIRSVILLE 69 53 69 49 / 70 20 40 20
CARTERSVILLE 74 56 75 51 / 40 10 30 10
COLUMBUS 78 57 79 55 / 30 5 20 5
GAINESVILLE 70 56 73 53 / 50 20 30 10
MACON 78 57 80 55 / 40 20 10 5
ROME 74 55 74 50 / 40 20 40 10
PEACHTREE CITY 76 55 76 51 / 40 10 30 5
VIDALIA 78 61 84 59 / 50 30 10 5
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...20/BAKER
LONG TERM....41
AVIATION...BAKER
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
1052 AM EDT SUN MAR 13 2016
.UPDATE...
OVERALL TREND WITH FIRST WEAK UPPER WAVE HAS BEEN DIMINISHING
SHOWERS TO THE NORTHEAST AND HI-RES SOLUTIONS ARE ONLY SHOWING
SOME ISOLATED TO MAYBE SCATTERED DEVELOPMENT AT BEST ACROSS
PORTIONS OF CENTRAL GA THIS AFTERNOON WHEN ANOTHER WEAK WAVE COULD
ALLOW FOR SOME REDEVELOPMENT. WHAT MAY ACTUALLY BETTER FOCUS ANY
CONVECTIVE INITIATION WOULD BE IF A THERMAL GRADIENT SETS UP FROM
SOLAR SHELTERING ALONG AN ENHANCED CLOUD COVERAGE AREA MAINLY EAST
OF A COLUMBUS TO ATHENS LINE /PER RECENT VIS SAT OBS/. RAP MLCAPE
IS PROGGED TO REACH IN 500-1000 J/KG RANGE MAXIMIZED IN EAST
CENTRAL GA BY AFTERNOON SO FEEL THIS IS BEST CHANCE AT ANY
THUNDERSTORMS THOUGH NOT ANTICIPATING ANY ACTIVITY TO BE INTENSE
/CANNOT RULE OUT A FEW STRONG HOWEVER/. OTHERWISE MADE MINOR
ADJUSTMENTS TO OTHER FCST TRENDS AND PREVIOUS DISCUSSION
FOLLOWS...
BAKER
&&
.PREV DISCUSSION... /ISSUED 747 AM EDT SUN MAR 13 2016/
.SHORT TERM /TODAY THROUGH MONDAY/...
INITIAL SHORT WAVE LIFTING NORTH OUT OF EAST TEXAS INTO THE MID-
MISSISSIPPI VALLEY THIS MORNING. MODELS CONTINUE TO INDICATE THIS
INITIAL WAVE WILL CONTINUE TO WEAKEN AS THE NEXT SHORT WAVE DIGS
INTO THE SOUTHERN PLAINS. HAVE NOT SEEN ANY SIGNIFICANT LIGHTNING
ACTIVITY NEARBY WITH THIS SYSTEM OVERNIGHT...HOWEVER MARGINAL
INSTABILITY AVAILABLE FOR A SLIGHT CHANCE THIS MORNING AND A
CHANCE THIS AFTERNOON. MID-LEVEL LAPSE RATES VERY WEAK AND
DYNAMICS ARE LACKING A BIT AS WELL SO STRONG TO SEVERE
THUNDERSTORMS ARE NOT EXPECTED. A BIT OF A BREAK TONIGHT AS THE
FIRST SYSTEM EXITS AND THE NEXT APPROACHES. COMPACT BUT FAIRLY
STRONG WAVE SWEEPS THROUGH THE TENNESSEE VALLEY MONDAY. MID-LEVEL
LAPSE RATES...AND SUBSEQUENTLY INSTABILITY...ARE A BIT HIGHER WITH
THIS NEXT SYSTEM. ALTHOUGH CHANCES FOR SEVERE THUNDERSTORMS ARE
NOT GREAT...CANNOT RULE OUT A FEW STRONG STORMS ACROSS NORTH
GEORGIA MONDAY.
20
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
RIDGING SHOULD DOMINATE THE FORECAST AREA MONDAY NIGHT INTO
TUESDAY IN THE WAKE OF THE EXITING TN VALLEY SHORT WAVE. STRONG
LOW PRESSURE MOVING ALONG THE GREAT LAKES SHOULD PUSH A FRONTAL
BOUNDARY INTO THE APPALACHIANS ON WEDNESDAY. MOISTURE LOOKS
LIMITED WITH THIS...BUT MODELS WANT TO DEVELOP A WAVE ON THE FRONT
AS IT DRIFTS INTO CENTRAL GA BY THURSDAY. LOW POPS LOOK OKAY FOR
WEDNESDAY AND THURSDAY...WITH SOME DRYING ACROSS THE NORTH BY
THURSDAY NIGHT. MOISTURE RETURNS FRIDAY AND SATURDAY AS IT LOOKS
LIKE THE BOUNDARY BEGINS TO PUSH BACK TO THE NORTH. THIS IS NOT AS
CLEAR CUT...HOWEVER CHANCE POPS FOR FRIDAY AND SATURDAY STILL LOOK
OKAY. TEMPERATURES REMAIN WARM BUT SOME COOLING IS NOTED TOWARD
THE END OF THE PERIOD.
41
&&
.AVIATION...
12Z UPDATE...
INITIAL MVFR CIGS NEAR 1200-2500 FT AND SOME SLIGHT VSBY
REDUCTIONS ACROSS MAJORITY OF TAF SITES WITH SOME POSSIBLE
IMPROVING FOR THE SOUTHERN SITES. TRENDS SHOULD IMPROVE TO VFR
NEAR 4-5 KFT AFTER 18Z TODAY THEN BACK TO MVFR MONDAY MORNING
AFTER 08-10Z ALONG WITH MVFR VSBYS. AREAS OF SHOWERS SHOULD PUSH
NORTHEAST THROUGH MID MORNING THEN GRADUALLY TAPER OFF FROM THE
SOUTHWEST...CANNOT RULE OUT ISOLATED THUNDER BUT CHANCE TOO LOW TO
MENTION IN TAF. WINDS STARTING TO SWING SW WITH SOME LOW END GUSTS
POSSIBLE THROUGH MIDDAY...STAYING NEAR SSW FOR OVERNIGHT.
//ATL CONFIDENCE...12Z UPDATE...
MEDIUM ON CIGS AND PRECIP TIMING.
HIGH ON ALL ELSE.
20/BAKER
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 74 56 77 53 / 50 30 40 10
ATLANTA 74 58 75 55 / 40 20 40 5
BLAIRSVILLE 69 53 69 49 / 70 40 50 10
CARTERSVILLE 74 56 75 51 / 40 20 40 5
COLUMBUS 78 57 79 55 / 30 10 20 0
GAINESVILLE 70 56 73 53 / 50 30 40 10
MACON 78 57 80 55 / 40 30 20 5
ROME 74 55 74 50 / 40 20 40 5
PEACHTREE CITY 76 55 76 51 / 40 10 30 5
VIDALIA 78 61 84 59 / 50 30 10 5
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...20/BAKER
LONG TERM....41
AVIATION...20/BAKER
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
904 PM CDT MON MAR 14 2016
.UPDATE...
ISSUED AT 855 PM CDT MON MAR 14 2016
Tricky overnight cloud/fog forecast across central and southeast
Illinois. Skies were steadily clearing from the west earlier this
evening. However, the clearing has slowed considerably, with the
cloud edge nearly along the I-74 corridor. Temperature/dew point
spreads across the area are quite small, and little to no sunshine
was available to help dry the wet ground from yesterday. These
factors, combined with light winds should allow stratus and/or fog
to develop once again tonight. The potential is certainly there
for dense fog to develop once again, but do not plan an advisory
at this time. Increasing southerly flow by late tonight ahead of
tomorrow`s storm system should help to blow the remaining low
cloud deck out of the area, and mix the low levels up a bit and
hopefully minimize the fog threat.
Going forecast is in pretty good shape. Already made adjustments
for less clouds in most areas. Most other tweaks were minor.
&&
.SHORT TERM...(Tonight)
ISSUED AT 235 PM CDT MON MAR 14 2016
19z/2pm visible satellite imagery continues to show cloudy skies
across central Illinois: however, holes are developing in the
overcast...particularly upstream across Iowa/Missouri. Low-level
flow remains weak, but this drier air will eventually filter into
the area this evening, resulting in a partial clearing trend. With
some clearing taking place and winds staying quite light, think fog
will re-develop tonight. Mitigating factors for widespread dense
fog will be partial cloud cover and increasing southeasterly winds
after midnight. HRRR is showing fog forming across much of the area
this evening, then becoming locally dense after midnight. Think
this is a bit overdone, so will only carry patchy fog at this time.
Most high-res models are suggesting scattered convection will
develop overnight across northern Missouri into Iowa as a
strengthening low-level jet noses into that area. Some of this
activity could spill into west-central Illinois toward dawn, so have
included low chance PoPs for showers/thunder along and west of the
Illinois River well after midnight. Overnight lows will be in the
lower to middle 50s.
.LONG TERM...(Tuesday through Monday)
ISSUED AT 235 PM CDT MON MAR 14 2016
Forecast concern continues to revolve around the the threat for
severe weather over parts of central through east central Illinois
tomorrow afternoon and evening as a rather potent upper wave
pushes into the Midwest.
Looks as though scattered precip chances tomorrow will be tied to
the surface and 850 mb warm front in the morning, mostly across
the west and north, and then along the cold front during the mid
to late afternoon and early evening hours as the cap weakens due
to increasing low level convergence forecast along the accelerating
cold front. The GFS continues to be the fast model, although
recent runs have trended a bit slower tomorrow afternoon, while
the ECMWF is deepest and slowest with the surface and upper level
features. Due to the slower movement in the cold frontal passage
and the cap holding on a bit longer than previously forecast, it
appears the main time frame for the threat for scattered storms
across the forecast area will be roughly 4pm until 10 pm. The NAM
and ECMWF indicates the better low level shear profiles for any
persistent rotating storms capable of large hail and isolated
tornadoes will be along and north of I-74, while low level wind
profiles become more unidirectional further south by late in the
afternoon. However, the further south you go, the stronger the
capping inversion is, but believe at least widely scattered storms
will be possible as you head into southeast IL late tomorrow
afternoon through the evening hours. All models indicate steep low
and mid level lapse rates with 700-500 mb lapse rates approaching
8 C/KM tomorrow afternoon and evening suggesting the threat for
large hail along with damaging wind gusts, especially if the mode
transitions to a line of storms with time late in the afternoon
into the evening hours.
Models sweep the storms well off to our east by 03z with lingering
low chance POPs over the far north during the overnight hours
along with gusty winds as the deepening surface low shifts slowly
off to our north. Windy but mild conditions are expected Wednesday
before we see a gradual transition to cooler weather by the end of
the week and next weekend where afternoon temperatures will lower
into the upper 40s to lower 50s. As far as precip is concerned in
the extended, several weak waves are forecast to rotate south
around the deep upper low to our north which may produce some
isolated light showers with the main threat of rain coming along
over the weekend as the upper low to our north repositions itself
a bit further south over the Midwest. This will bring about
mentionable rain chances in the forecast on Saturday into Saturday
night.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
ISSUED AT 657 PM CDT MON MAR 14 2016
Low cloud CIGs currently scattering out across the central
Illinois terminals. This will allow VFR conditions to develop.
However, based on the recent rains and light winds expected
overnight, expect at least MVFR conditions to develop again
tonight as fog and/or stratus develops. Winds will pick up
Tuesday ahead of a strong cold front, becoming gusty out of the
south to southeast. Scattered showers/storms possible in the
afternoon ahead of the front, but coverage is not expected to be
high and have left mention out for now. Mention will be added once
a little more detail can be added.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...BAK
SHORT TERM...Barnes
LONG TERM...Smith
AVIATION...BAK
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
702 PM CDT MON MAR 14 2016
.SHORT TERM...(Tonight)
ISSUED AT 235 PM CDT MON MAR 14 2016
19z/2pm visible satellite imagery continues to show cloudy skies
across central Illinois: however, holes are developing in the
overcast...particularly upstream across Iowa/Missouri. Low-level
flow remains weak, but this drier air will eventually filter into
the area this evening, resulting in a partial clearing trend. With
some clearing taking place and winds staying quite light, think fog
will re-develop tonight. Mitigating factors for widespread dense
fog will be partial cloud cover and increasing southeasterly winds
after midnight. HRRR is showing fog forming across much of the area
this evening, then becoming locally dense after midnight. Think
this is a bit overdone, so will only carry patchy fog at this time.
Most high-res models are suggesting scattered convection will
develop overnight across northern Missouri into Iowa as a
strengthening low-level jet noses into that area. Some of this
activity could spill into west-central Illinois toward dawn, so have
included low chance PoPs for showers/thunder along and west of the
Illinois River well after midnight. Overnight lows will be in the
lower to middle 50s.
.LONG TERM...(Tuesday through Monday)
ISSUED AT 235 PM CDT MON MAR 14 2016
Forecast concern continues to revolve around the the threat for
severe weather over parts of central through east central Illinois
tomorrow afternoon and evening as a rather potent upper wave
pushes into the Midwest.
Looks as though scattered precip chances tomorrow will be tied to
the surface and 850 mb warm front in the morning, mostly across
the west and north, and then along the cold front during the mid
to late afternoon and early evening hours as the cap weakens due
to increasing low level convergence forecast along the accelerating
cold front. The GFS continues to be the fast model, although
recent runs have trended a bit slower tomorrow afternoon, while
the ECMWF is deepest and slowest with the surface and upper level
features. Due to the slower movement in the cold frontal passage
and the cap holding on a bit longer than previously forecast, it
appears the main time frame for the threat for scattered storms
across the forecast area will be roughly 4pm until 10 pm. The NAM
and ECMWF indicates the better low level shear profiles for any
persistent rotating storms capable of large hail and isolated
tornadoes will be along and north of I-74, while low level wind
profiles become more unidirectional further south by late in the
afternoon. However, the further south you go, the stronger the
capping inversion is, but believe at least widely scattered storms
will be possible as you head into southeast IL late tomorrow
afternoon through the evening hours. All models indicate steep low
and mid level lapse rates with 700-500 mb lapse rates approaching
8 C/KM tomorrow afternoon and evening suggesting the threat for
large hail along with damaging wind gusts, especially if the mode
transitions to a line of storms with time late in the afternoon
into the evening hours.
Models sweep the storms well off to our east by 03z with lingering
low chance POPs over the far north during the overnight hours
along with gusty winds as the deepening surface low shifts slowly
off to our north. Windy but mild conditions are expected Wednesday
before we see a gradual transition to cooler weather by the end of
the week and next weekend where afternoon temperatures will lower
into the upper 40s to lower 50s. As far as precip is concerned in
the extended, several weak waves are forecast to rotate south
around the deep upper low to our north which may produce some
isolated light showers with the main threat of rain coming along
over the weekend as the upper low to our north repositions itself
a bit further south over the Midwest. This will bring about
mentionable rain chances in the forecast on Saturday into Saturday
night.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
ISSUED AT 657 PM CDT MON MAR 14 2016
Low cloud CIGs currently scattering out across the central
Illinois terminals. This will allow VFR conditions to develop.
However, based on the recent rains and light winds expected
overnight, expect at least MVFR conditions to develop again
tonight as fog and/or stratus develops. Winds will pick up
Tuesday ahead of a strong cold front, becoming gusty out of the
south to southeast. Scattered showers/storms possible in the
afternoon ahead of the front, but coverage is not expected to be
high and have left mention out for now. Mention will be added once
a little more detail can be added.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Barnes
LONG TERM...Smith
AVIATION...BAK
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
259 PM CDT SUN MAR 13 2016
.SHORT TERM...(Tonight)
ISSUED AT 245 PM CDT SUN MAR 13 2016
19z/2pm surface analysis shows a 1005mb low near KPIA, with
widespread light showers ongoing across the western half of the KILX
CWA. Further east and south, the steady precip has diminished to
widely scattered showers along/south of a Danville to Taylorville
line. The primary area of rain will continue to dissipate/retreat
northward as the low tracks into northern Illinois this evening.
Based on radar timing tools, most of the rain will be just north of
the CWA by early evening. Will therefore only carry chance PoPs
through the evening, with highest chances focused across the far
north around Galesburg and Lacon in closer proximity to the departing
low. A second area of low pressure currently over Oklahoma will
track into western Kentucky by Monday morning. This feature will
spread showers and a few thunderstorms into the SE CWA overnight, so
have carried likely PoPs along/south of I-70 after midnight
accordingly. Due to a very weak pressure gradient, winds will be
light and variable tonight. With nearly calm winds and ample low-
level moisture left behind by the rainfall today, think fog will re-
develop across the area tonight. HRRR continues to show widespread
fog across all but the SE where rain will be falling. The fog could
potentially become dense: however, timing and areal extent remain in
question. Will carry areas of fog in the forecast, but later shifts
may need to issue a Dense Fog Advisory if trends become apparent
later this evening.
&&
.LONG TERM...(Monday through Sunday)
ISSUED AT 245 PM CDT SUN MAR 13 2016
Forecast focus this period on the threat for severe weather over
parts of the forecast area Tuesday afternoon/evening.
Compact upper level storm tracking east-northeast through Arkansas
then into western Ky Monday morning will bring showers and isolated
storms to parts of southeast Illinois, at least through the morning
hours, while further north, the low clouds, fog and shower chances
end from northwest to southeast during the morning with only the
southeast quarter of the forecast area still seeing the threat for
afternoon showers. Forecast soundings continue to hold on to the low
level moisture across the area into the afternoon hours so the
prospects for much in the way of sunshine are low, with most areas
seeing afternoon temperatures rise into the low to mid 60s.
As the deepening upper wave for Tuesday pushes across the Rockies
and into the high Plains late Monday night, the threat for at
least scattered showers and storms will increase out to our west
Monday night with chances increasing over our western counties
after Midnight. Still some significant differences with respect to
how quickly the upper wave tracks east across the Great Lakes with
the ECMWF the slowest, while the GFS remains the fastest in pushing
the front to our east by late afternoon Tuesday. The ECMWF digs
the shortwave southeast in response to ridging over the eastern
Pacific and that is tending to slow the system down compared to
the more progressive look from the GFS and SREF ensemble solutions.
You would have thought we would have seen a slowing trend from the
GFS, NAM and SREF solutions by now, but up through the 12z models
runs of today, we haven`t, which keeps confidence on timing and
storm mode in our area on Tuesday low.
All models continue to show deep layer shear associated with the
upper wave as it becomes negatively tilted late in the day Tuesday
with strong low level turning of the winds seen on the hodographs,
especially off the NAM. 850 mb winds depicted on the ECMWF were
southeasterly at 40-45 kts in the 21z-00z time frame across our
north. SREF forecasts of surface dew points were a bit more
conservative on Tuesday afternoon, compared with the NAM, with
mostly middle 50s forecast across our area, while the NAM near
60 degree dew points which pushed SB cape values above 2500 J/KG
over the eastern half of the forecast area Tuesday afternoon.
Forecast soundings off the NAM and GFS continue to show a capping
inversion in place at least into the early afternoon hours before
low level convergence starts to increase in the 925-850 mb layer
just ahead of the front, which should allow convection to
develop. The 4km NAM-WRF reflectivity simulations suggest the
development of storms off to our east after 21z just ahead of the
increasing low level moisture convergence. However, if the timing
off the ECMWF is correct, storms will develop by mid afternoon
further west, along or just west of Interstate 55 and streak east-
northeast through the rest of the forecast area by 02z.
Based off the low level wind profiles seen on the ECMWF, discrete
supercells capable of large hail (with 700-500 mb lapse rates over
7.0 C/KM) damaging winds and isolated tornadoes will be possible
for a few hours, especially if the high dew points seen on the NAM
verify, before cells consolidate into a fast moving line with
mainly a damaging wind threat through late afternoon into early
evening. If the GFS verifies, storms will develop in areas east of
I-55 and be out of our area by 00z. Still quite a bit of uncertainty
with the timing of the shortwave and attendant cold front for late
Tuesday afternoon and evening. For now, will continue to mention
the higher probabilities for damaging straight line winds and hail
in the HWO for Tuesday, but as mentioned above, if the low level
moisture increases more than what is advertised in most models,
the tornado threat will start to become a concern as well Tuesday
afternoon.
Highest POPS for Tuesday will continue to be across the north with
progressively lower POPs as you head south during the afternoon and
evening. Strong gusty southerly winds are expected by late morning
into the afternoon hours as the deepening upper and surface lows
track to our west-northwest. Shower chances start to decrease
later Tuesday night as the front shifts well off to our east and
then windy conditions expected Wednesday in the wake of the storm
as it tracks slowly east across north-central Wisconsin.
Temperatures at least initially, will not cool off much on Wed.
with upper 50s to lower 60s expected during the afternoon, with
the gradual cooling trend starting on Thursday and continuing
through Sunday with temperatures returning closer to normal for
this time of year. Our next chance for rain across central IL will
be next weekend, but POPs were kept low this far out as model
spread was large.
&&
.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
ISSUED AT 1237 PM CDT SUN MAR 13 2016
17z/12pm surface analysis shows a 1006mb low between KPIA and
KSPI. Winds to the east of the low are from the S/SW at most of
the central Illinois terminals early this afternoon, while winds
to the west of the low remain from the NE at KPIA. As the low
tracks into northern Illinois, a trailing trough axis will lead to
a very weak pressure gradient tonight, resulting in light/variable
winds through 18z Mon. Rain is currently falling across much of
the area: however, the rain area is rapidly lifting to the N/NW.
Based on radar timing tools, have ended predominant rain at
KSPI/KDEC/KCMI by 20z...then further northwest to KPIA by 23z.
Despite an end to the steady precip, IFR ceilings will continue
through the entire 18z TAF period. Due to very light winds and
ample low-level moisture, fog will re-develop tonight. Early
indications from the HRRR suggest it could become locally dense
after midnight. Have included a tempo group with visbys down to
1/2 miles at all sites between 08z and 12z accordingly.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Barnes
LONG TERM...Smith
AVIATION...Barnes
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1237 PM CDT SUN MAR 13 2016
.UPDATE...
ISSUED AT 901 AM CDT SUN MAR 13 2016
Persistent upper low that had been in place over Texas for the
past couple of days has finally been ejected northward and is now
located over southern Illinois. With strong synoptic lift and
deep-layer moisture in place as evidenced by the 12z KILX upper
air sounding, widespread showers are accompanying the weakening
low. 14z/9am radar imagery shows showers blanketing nearly the
entire area, except southeast of I-70 where the precip is a bit
more scattered in nature. Given current trends, have increased
PoPs to 100 percent across the board this morning. Models continue
to show the wave lifting into the southern Great Lakes later
today, leading to a decrease in precip this afternoon/evening.
Have lowered PoPs to the chance category along/south of I-72 by
late this afternoon accordingly. Given weak pressure gradient in
the vicinity of a surface wave tracking through central Illinois,
winds will remain quite light and areas of fog will likely persist
for much of the day. Afternoon high temperatures will range from
the middle 50s far north around Galesburg and Lacon...to the
middle 60s south of I-70. Forecast update has already been issued.
&&
.SHORT TERM...(Today)
ISSUED AT 336 AM CDT SUN MAR 13 2016
A weakening open upper level wave is now moving rapidly northeast
toward the Midwest...while a weak frontal boundary is draped east-
west across Illinois near St. Louis to Lawrenceville. A scattered
line of showers is oriented across the state north of the boundary
in warm advection aloft...while additional showers are approaching
from the south lifted by the approaching upper low. While scattered
showers are likely much of the day as a result of these two
features, the best chances will be I-55/I-155 eastward according to
the current trajectory of the upper low. Quite a few observations of
1-2 mile visibility in fog noted in observations this morning, with
a few lower values as well. Have included patchy fog in the forecast
for today as a result. Instability looks to be weak today...but
enough for isolated thunderstorms from Schuyler county to Vermilion
county southward by late morning. Winds today should be weak and
somewhat variable as the weak surface low passes through central IL,
and temperatures ranging from 57 in Galesburg to 66 in Lawrenceville.
.LONG TERM...(Tonight through Saturday)
ISSUED AT 336 AM CDT SUN MAR 13 2016
Weakening upper level low pressure near the eastern MO/AR border
tracks toward the eastern central IL and IN border by sunset and
into southern lower MI by sunrise Monday. Meanwhile a 2nd cutoff
upper level low (553 dm over north Texas) to track into the Ozarks
in northern AR by midnight tonight and into southern IL by sunrise
Monday. A good chance of showers this evening across CWA with areas
of fog northern CWA and isolated thunderstorms south of a Rushville
to Bloomington line. Then best chances of showers and isolated
thunderstorms shifts into southeast IL overnight with approaching
2nd upper level low and better lift in southern IL overnight. Lows
tonight in the upper 40s north and mid 50s near Lawrenceville.
Continued chances of showers Monday morning with isolated
thunderstorms east of I-57, then shower chances diminish from the
west by Monday afternoon as 2nd upper level low lifts to the
northern IN/OH border by sunset Monday. A fair amount of low clouds
lingers Monday with highs in the low to mid 60s, coolest from I-74
ne. Most areas will be dry Monday night, though have 20-30% chance
of showers and isolated thunderstorms after midnight monday night
from I-55 west. This due to a stronger storm system off the Pacific
NW coast that moves east into the central/northern plains by 12Z/Tue
with increase WAA pattern ahead of this storm giving isolated
elevated convection westcentral/nw IL overnight Monday night.
Strong negative tilted upper level low moves toward the upper MS
river valley by sunset Tue and sweeps a cold front east across IL
later Tue afternoon and early Tue evening. Breezy south winds ahead
of this storm system brings milder highs in the low to mid 70s. Also
will see increasing chances of showers and thunderstorms during the
day Tue with likely pops from I-74 north by Tue afternoon while just
slight chances south of I-70 Tue afternoon/evening. SPC day 3
outlook has a slight risk across most of IN and central and
northern IL, including all but far sw CWA on Tue afternoon and
early Tue evening. Strong wind shear peaking around 50 knots and
MUCapes by Tue afternoon of 1500-2500 j/kg supports slight risk of
severe storms. Damaging wind gusts is main severe wx threat
though supercells with large hail and possible tornadoes also a
risk.
Extended models continue to show strong upper level low staying over
the western Great Lakes region Wed and Thu and will bring in cooler
temps but still above normal. Highs Wed around 60F northern CWA and
near 65F by Lawrenceville and most areas dry on Wed with breezy sw
winds. Have small chances of showers returning Wed night into Thu
over mainly northern areas and cooler highs Thu in the 50s.
The extended models not in good agreement with forecast end of this
week into next weekend and will use a blend. Still appears to be a
large upper level trof digging into the great plains late this
weekend and more unsettled weather returning to IL next weekend
starting Friday night and going through next Sunday. Temps to be
closer to normal next weekend with highs in the upper 40s/lower 50s
and a fair amount of cloud cover with the chances of rain showers.
&&
.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
ISSUED AT 1237 PM CDT SUN MAR 13 2016
17z/12pm surface analysis shows a 1006mb low between KPIA and
KSPI. Winds to the east of the low are from the S/SW at most of
the central Illinois terminals early this afternoon, while winds
to the west of the low remain from the NE at KPIA. As the low
tracks into northern Illinois, a trailing trough axis will lead to
a very weak pressure gradient tonight, resulting in light/variable
winds through 18z Mon. Rain is currently falling across much of
the area: however, the rain area is rapidly lifting to the N/NW.
Based on radar timing tools, have ended predominant rain at
KSPI/KDEC/KCMI by 20z...then further northwest to KPIA by 23z.
Despite an end to the steady precip, IFR ceilings will continue
through the entire 18z TAF period. Due to very light winds and
ample low-level moisture, fog will re-develop tonight. Early
indications from the HRRR suggest it could become locally dense
after midnight. Have included a tempo group with visbys down to
1/2 miles at all sites between 08z and 12z accordingly.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...Barnes
SHORT TERM...Onton
LONG TERM...07
AVIATION...Barnes
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
130 AM CST SUN MAR 13 2016
.SHORT TERM...
231 PM CST
TONIGHT THROUGH SUNDAY...
MAIN FOCUS IN THE NEAR TERM OF THE FORECAST IS ON PRECIPITATION
TRENDS AS RAIN EVENTUALLY OVERSPREADS THE AREA THROUGH SUNDAY
MORNING.
18Z SURFACE ANALYSIS DEPICTS WEAKENING HIGH PRESSURE CENTERED
JUST EAST OF THE CWA OVER THE CENTRAL GREAT LAKES. FARTHER
SOUTH...AN AREA OF LOW PRESSURE WAS DEVELOPING ALONG THE LOUISIANACOAST...AND
IS PROGGED TO DEVELOP NORTHWARD THIS EVENING INTO REGION OF WEAK
PRESSURE FALLS OVER THE ARKLATEX AND LOWER MISSISSIPPI VALLEY.
THIS IS IN RESPONSE TO MID-LEVEL SHORT WAVE/OLD CLOSED UPPER LOW
OVER TEXAS WHICH IS BEING KICKED OUT TO THE NORTHEAST BY ANOTHER
STRONG MID-LEVEL CIRCULATION SEEN IN AFTERNOON WATER VAPOR IMAGERY
OVER THE FOUR CORNERS REGION. THIS LEAD SHORT WAVE LIFTS NORTHEAST
ACROSS IL/IN SUNDAY...WITH PRECIP POTENTIAL RAMPING UP ESPECIALLY
LATE TONIGHT AND EARLY SUNDAY AS WAVE APPROACHES AND INCREASES
MOIST ASCENT ACROSS LOW LEVEL WARM FRONTAL BAROCLINIC ZONE
CURRENTLY ANALYZED ACROSS THE LOWER MISSOURI/TENNESSEE RIVER
VALLEYS. IN FACT A WEAKER LEAD SHORT WAVE WAS ALREADY PRODUCING
SOME LIGHT RAIN ACROSS PARTS OF NORTHEAST MO/EASTERN IA/NORTHWEST
AND NORTH CENTRAL IL THIS AFTERNOON IN A REGION OF ELEVATED
MOISTURE TRANSPORT AND ISENTROPIC ASCENT ON THE 300-305 K THETA
SURFACES. AMDAR AND RAP ANALYSIS SOUNDINGS DEPICT LOW LEVELS BELOW
500-600 MB ARE FAIRLY DRY ACROSS FAR NORTHERN IL...AND WILL LIKELY
TAKE SOME TIME TO MOISTEN AND SATURATE MORE FULLY.
HOWEVER...SCATTERED LIGHT SHOWERS ARE LIKELY ESPECIALLY ACROSS
NORTHWEST AND NORTH CENTRAL IL INTO THIS EVENING. POPS WILL
GRADUALLY INCREASE FROM SOUTH-NORTH OVERNIGHT AS LOW LEVEL
WARM/MOIST ADVECTION STRENGTHENS AND AFOREMENTIONED SHORT WAVE
APPROACHES.
MID-LEVEL SHORT WAVE CONTINUES TO PROPAGATE A LITTLE MORE SLOWLY
TO THE NORTHEAST ACROSS THE AREA SUNDAY...WITH SURFACE LOW
PRESSURE WAVE TRACKING ACROSS THE SOUTHEAST PART OF THE CWA DURING
THE AFTERNOON. SHOWERS/RAIN ARE EXPECTED TO BE FAIRLY PERSISTENT
ACROSS THE CWA GIVEN THE PROXIMITY OF MID-LEVEL FORCING AND THE
LOW LEVEL BAROCLINIC ZONE. GUIDANCE GENERALLY DEPICTS THE GREATEST
RAINFALL ACROSS THE SOUTHEAST THIRD TO HALF OF THE CWA BY SUNDAY
EVENING WITH AMOUNTS GENERALLY IN THE 0.75 TO 1.00 INCH RANGE.
THIS APPEARS REASONABLE AGAIN GIVEN ALIGNMENT OF FORCING FEATURES
AND PWATS OF 1+ INCHES WHICH IS WELL ABOVE THE 90 PERCENTILE BASED
ON ILX SOUNDING CLIMATOLOGY FOR MID-MARCH. DEEP MOIST-ADIABATIC
LAPSE RATES ALSO APPEAR TO YIELD SOME WEAK ELEVATED CAPE ACROSS
THE SOUTHEAST PORTION OF THE CWA AND HAVE INCLUDED SLIGHT CHANCE
FOR THUNDER ACROSS ABOUT THE SOUTHERN TIER OR SO OF CWA COUNTIES
FROM AFTER MIDNIGHT TONIGHT INTO SUNDAY.
TEMPS REACHED THE UPPER 50S/LOW 60S AWAY FROM LAKE MICHGAN THIS
AFTERNOON THOUGH CLOUD COVER HAS LIMITED THE CLIMB SOMEWHAT. CLOUD
COVER AND INCREASING LOW LEVEL DEW POINT TEMPS SHOULD KEEP MIN
TEMPS TONIGHT IN THE 40S MOST AREAS AND AROUND 50 FAR SOUTH...AND
DESPITE EXTENSIVE CLOUD COVER AND RAIN ON SUNDAY...PURE ADVECTION
OF WARMER AIR MASS SHOULD RESULT IN TEMP AGAIN IN THE UPPER
50S/LOW 60S SOUTH. INCREASING EAST WINDS (10-20 MPH) WILL COMBINE
WITH THE CLOUDS AND RAIN TO KEEP THINGS COOLER NORTH OF THE LOW
LEVEL SURFACE WAVE AND BAROCLINIC REGION...WITH TEMPS FROM THE MID
40S ALONG THE LAKE TO THE LOWER 50S FARTHER INLAND IN LINE
GUIDANCE TRENDS.
RATZER
&&
.LONG TERM...
303 PM CST
SUNDAY NIGHT THROUGH SATURDAY...
MAIN FORECAST CONCERNS/CHALLENGES ARE WITH LINGERING PRECIP
CHANCES SUNDAY NIGHT INTO MONDAY MORNING AND THEN WITH RETURNING
CHANCES FOR SHOWERS AND THUNDERSTORMS LATE MONDAY NIGHT INTO
TUESDAY AFTERNOON/EVENING...WITH THE POSSIBILITY OF ISOLATED
STRONG TO SEVERE THUNDERSTORMS DURING THAT TIME.
A WET START TO THE PERIOD IS STILL APPEARING LIKELY SUNDAY NIGHT.
CYCLONIC FLOW IN PLACE WITH MID LEVEL ENERGY TRAVERSING THIS FLOW
ALONG WITH SLOWLY MOVING SURFACE REFLECTION LOOK TO STILL PROVIDE
PERIODIC RAIN SHOWERS SUNDAY NIGHT. DID MAINTAIN LIKELY POPS FOR
THE AREA IN THE EVENING BUT SLOWLY DECREASE FROM WEST TO EAST
OVERNIGHT INTO EARLY MONDAY MORNING AS THIS SYSTEM BEGINS TO
DEPART TO THE EAST/NORTHEAST. FORECAST SOUNDINGS DO INDICATE SOME
WEAK INSTABILITY IN PLACE FOR THE FAR SOUTHERN CWA IN THE EVENING
AND THIS SEEMS REASONABLE GIVEN THAT LOCATION WILL STILL LIKELY BE
IN AN AXIS OF HIGHER MOISTURE CONTENT AIR. SO HAVE INCLUDED
MENTION OF SLIGHT CHANCE THUNDER MAINLY FOR THE INDIANA COUNTIES
SOUTH OF THE KANKAKEE RIVER. ANY THUNDER CHANCES QUICKLY DIMINISH
LATER IN THE NIGHT WITH THE ARRIVAL OF DRIER AIR AND WEAKENING
FORCING. CONTINUE THE LOWERING TREND WITH POPS ON MONDAY AS THIS
SYSTEM FURTHER DEPARTS. HOWEVER...THERE DOES APPEAR TO BE A
POSSIBILITY FOR SOME ISOLATED TO SCATTERED SHOWER DEVELOPMENT
ALONG THE BACK SIDE OF THIS SYSTEM WITH SOME WEAK LARGE SCALE
ASCENT AND FORCING ALONG DEPARTING BOUNDARY. DO LEAVE SOME CHANCE
POPS IN THE MORNING BUT GO MAINLY DRY IN THE AFTERNOON.
AFTER LIKELY DRY CONDITIONS IN THE AFTERNOON AND A PORTION OF THE
EVENING ON MONDAY...DO BRING BACK SLIGHT CHANCE POPS ACROSS NORTH
CENTRAL ILLINOIS AND THEN CHANCE POPS AFTER MIDNIGHT. APPROACHING
SYSTEM TAKING SHAPE OVER THE PLAINS WILL ALLOW BACKING LOW/MID
LEVEL FLOW TO INCREASE DURING THIS NIGHT. AS THIS OCCURS...WAA
LOOKS TO RAMP UP WITH AT LEAST SOME ISOLATED SHOWER DEVELOPMENT
ALONG THIS WAA AXIS. GUIDANCE PRETTY CONSISTENT WITH INCREASING
INSTABILITY ALSO DURING THIS PERIOD...AND SO HAVE INCLUDED SLIGHT
CHANCE THUNDER GIVEN THIS SIGNAL AND PATTERN.
MORNING GUIDANCE COMING IN FAIRLY CONSISTENT WITH ONE ANOTHER ON
THE NEXT SYSTEM TO LIKELY IMPACT THE REGION ON TUESDAY. FORECAST
GUIDANCE STILL ADVERTISING AN UPPER LEVEL TROUGH BECOMING HIGHLY
AMPLIFIED OVER THE PLAINS DURING THE DAY TUESDAY...WHILE UPPER
LEVEL JET STREAK OF AT LEAST 120KT SWINGS THROUGH THE REGION. MID
LEVEL FLOW/ENERGY IS ALSO APPEARING RATHER ROBUST WITH MID LEVEL
FLOW OF AROUND 100KT BECOMING POSSIBLE...AND WITH GUIDANCE
INDICATING A STOUT VORT MAX TO PUSH THROUGH THE REGION IN THE LATE
AFTERNOON AND EARLY EVENING. GROWING MORE CONCERNED FOR
THUNDERSTORM CHANCES ACROSS MUCH OF THE CWA DURING THIS TIME
ESPECIALLY AS A WARM/MOIST ENVIRONMENT ADVECTS NORTH OUT AHEAD OF
THIS SYSTEM. IN REGARDS TO MOISTURE RETURN...MODEL CONSENSUS IS
STILL INDICATING MODEST MOISTURE RETURN DURING THE DAY TUESDAY BUT
WITH SOME PIECES OF GUIDANCE INDICATING A LITTLE MORE AGGRESSIVE
RETURN OF MOISTURE TO THE AREA. IN THIS SCENARIO...INSTABILITY
INCREASES SIGNIFICANTLY WITH THE THREAT OF THUNDERSTORMS AND EVEN
STRONG TO SEVERE THUNDERSTORM DEVELOPMENT LIKELY INCREASING.
HOWEVER...NOT COMPLETELY SOLD ON THIS SOLUTION QUITE YET AND HAVE
GONE WITH MORE OF A CONSERVATIVE APPROACH. EVEN IN THIS
CONSERVATIVE APPROACH...THIS MODEST MOISTURE RETURN COULD STILL
YIELD WEAK INSTABILITY IN UPWARDS OF 500-1000 J/KG. GIVEN THIS
HIGHLY DYNAMIC SYSTEM AND EXPECTED STRONG KINEMATIC FIELD...EVEN
THIS POSSIBLE INSTABILITY IN THE PRESENCE OF THESE FEATURES COULD
ALLOW FOR AT LEAST SOME ISOLATED STRONG TO SEVERE THUNDERSTORMS.
STILL A LITTLE EARLY TO GATHER ANY STRONG CONFIDENCE ON EXACTLY
HOW TUESDAY WILL UNFOLD. HOWEVER...THIS PERIOD WARRANTS CLOSE
MONITORING FOR THIS THUNDERSTORM POTENTIAL.
RODRIGUEZ
&&
.AVIATION...
FOR THE 06Z TAFS...
WDLY SCATTERED -SHRA STILL EXPECTED THROUGH THE OVERNIGHT HOURS
WITH MORE OF AN UPTICK IN COVERAGE OF SHOWERS EXPECTED SUNDAY
MORNING...LIKELY BUILDING INTO MORE OF A STEADY RAIN BY MID-LATE
MORNING SUNDAY. RAIN SHOULD BEGIN TO TAPER OFF TO MORE OF A LIGHT
RAIN OR MORE LIKELY DRIZZLE BY LATE AFTERNOON INTO SUNDAY EVENING.
VFR CIGS WILL CONTINUE TO STEADILY LOWER OVERNIGHT...LIKELY TO
MVFR EARLY SUNDAY MORNING THEN QUICKLY DETERIORATING TO IFR SUNDAY
MORNING. CONTINUED RAIN/MOISTENING OF THE LOW LEVELS COMBINED WITH
WINDS OFF THE STILL COLD LAKE SHOULD RESULT IN A LOW AND SHARP
INVERSION WITH CIGS LIKELY BUILDING DOWN TO LIFR IN THE AFTERNOON.
GUIDANCE AND SYNOPTIC CLIMO BOTH SUGGEST POTENTIAL FOR VLIFR
CIGS/VSBY SUNDAY EVENING WITH DRIZZLE AND FOG CONTINUING.
GENERALLY STUCK CLOSE TO MAV/MET GUIDANCE FOR CIGS/VSBY SUNDAY
AFTERNOON AND NIGHT WHICH DOES BRING CONDITIONS CLOSE TO THE DECK.
GUIDANCE WAS A BIT MORE OPTIMISTIC AT MDW...SO KEPT THEM A BIT
HIGHER FOR NOW...BUT CONFIDENCE IS LOW AND WILL NEED TO BE
WATCHED. AT ORD...THE TOWER ENDS UP IN THE CIGS AT 200FT WHICH
TYPICALLY LEADS TO TOWER VSBY OF 1/2SM TO 1/4SM SO FELT MORE
COMFORTABLE BRINGING ORD TO NEAR THE DECK SUNDAY EVENING.
CONFIDENCE IN LOW CIGS/VSBY IS MEDIUM-HIGH SUNDAY EVENING THOUGH
CONFIDENCE IS LOWER IN PRECISELY HOW LOW IT GETS.
IZZI
&&
.MARINE...
125 AM CST
EASTERLY WINDS WILL BE ON THE INCREASE TODAY ACROSS THE LAKE AS
LOW PRESSURE DEVELOPS ACROSS CENTRAL ILLINOIS BY THIS AFTERNOON.
LOW-LEVEL MOISTURE WILL ALSO BE STEADILY INCREASING AND IS LIKELY
TO DEVELOP FOG...ESPECIALLY ACROSS THE SOUTH AS SHOWERS EASE IN
COVERAGE THROUGH THE AFTERNOON. THE FOG WILL PROBABLY BE DENSE IN
PARTS BY TONIGHT...AND MAYBE EVEN DURING THE AFTERNOON...AND AN
ADVISORY MAY BE NEEDED. THIS INCLUDES THE ILLINOIS AND INDIANA
NEARSHORES.
THE DEEP LOW PRESSURE FOR MIDWEEK IS STILL FORECAST TO MOVE
EASTWARD INTO THE MINNESOTA/WISCONSIN REGION BY TUESDAY NIGHT AND
PERSIST INTO WEDNESDAY EVENING. THE TREND WITH THE STRENGTH OF
THIS LOW HAS BEEN SLIGHTLY DOWNWARD THE PAST 12-24 HOURS IN
FORECAST MODELS...WHICH WOULD LIKELY KEEP GUSTS BELOW GALE FORCE
OVER THE LAKE DURING THAT TIME. WITH SUCH A DEEP LOW THE PATTERN
STILL BEARS WATCHING FOR POTENTIAL GALES AND AT LEAST SMALL CRAFT
ADVISORY CRITERIA IS ANTICIPATED FOR A PERIOD OR TWO DURING
MIDWEEK.
MTF
&&
.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
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1123 PM CST SAT MAR 12 2016
.SHORT TERM...
231 PM CST
TONIGHT THROUGH SUNDAY...
MAIN FOCUS IN THE NEAR TERM OF THE FORECAST IS ON PRECIPITATION
TRENDS AS RAIN EVENTUALLY OVERSPREADS THE AREA THROUGH SUNDAY
MORNING.
18Z SURFACE ANALYSIS DEPICTS WEAKENING HIGH PRESSURE CENTERED
JUST EAST OF THE CWA OVER THE CENTRAL GREAT LAKES. FARTHER
SOUTH...AN AREA OF LOW PRESSURE WAS DEVELOPING ALONG THE LOUISIANA
COAST...AND IS PROGGED TO DEVELOP NORTHWARD THIS EVENING INTO
REGION OF WEAK PRESSURE FALLS OVER THE ARKLATEX AND LOWER
MISSISSIPPI VALLEY. THIS IS IN RESPONSE TO MID-LEVEL SHORT
WAVE/OLD CLOSED UPPER LOW OVER TEXAS WHICH IS BEING KICKED OUT TO
THE NORTHEAST BY ANOTHER STRONG MID-LEVEL CIRCULATION SEEN IN
AFTERNOON WATER VAPOR IMAGERY OVER THE FOUR CORNERS REGION. THIS
LEAD SHORT WAVE LIFTS NORTHEAST ACROSS IL/IN SUNDAY...WITH PRECIP
POTENTIAL RAMPING UP ESPECIALLY LATE TONIGHT AND EARLY SUNDAY AS
WAVE APPROACHES AND INCREASES MOIST ASCENT ACROSS LOW LEVEL WARM
FRONTAL BAROCLINIC ZONE CURRENTLY ANALYZED ACROSS THE LOWER
MISSOURI/TENNESSEE RIVER VALLEYS. IN FACT A WEAKER LEAD SHORT WAVE
WAS ALREADY PRODUCING SOME LIGHT RAIN ACROSS PARTS OF NORTHEAST
MO/EASTERN IA/NORTHWEST AND NORTH CENTRAL IL THIS AFTERNOON IN A
REGION OF ELEVATED MOISTURE TRANSPORT AND ISENTROPIC ASCENT ON THE
300-305 K THETA SURFACES. AMDAR AND RAP ANALYSIS SOUNDINGS DEPICT
LOW LEVELS BELOW 500-600 MB ARE FAIRLY DRY ACROSS FAR NORTHERN
IL...AND WILL LIKELY TAKE SOME TIME TO MOISTEN AND SATURATE MORE
FULLY. HOWEVER...SCATTERED LIGHT SHOWERS ARE LIKELY ESPECIALLY
ACROSS NORTHWEST AND NORTH CENTRAL IL INTO THIS EVENING. POPS WILL
GRADUALLY INCREASE FROM SOUTH-NORTH OVERNIGHT AS LOW LEVEL
WARM/MOIST ADVECTION STRENGTHENS AND AFOREMENTIONED SHORT WAVE
APPROACHES.
MID-LEVEL SHORT WAVE CONTINUES TO PROPAGATE A LITTLE MORE SLOWLY
TO THE NORTHEAST ACROSS THE AREA SUNDAY...WITH SURFACE LOW
PRESSURE WAVE TRACKING ACROSS THE SOUTHEAST PART OF THE CWA DURING
THE AFTERNOON. SHOWERS/RAIN ARE EXPECTED TO BE FAIRLY PERSISTENT
ACROSS THE CWA GIVEN THE PROXIMITY OF MID-LEVEL FORCING AND THE
LOW LEVEL BAROCLINIC ZONE. GUIDANCE GENERALLY DEPICTS THE GREATEST
RAINFALL ACROSS THE SOUTHEAST THIRD TO HALF OF THE CWA BY SUNDAY
EVENING WITH AMOUNTS GENERALLY IN THE 0.75 TO 1.00 INCH RANGE.
THIS APPEARS REASONABLE AGAIN GIVEN ALIGNMENT OF FORCING FEATURES
AND PWATS OF 1+ INCHES WHICH IS WELL ABOVE THE 90 PERCENTILE BASED
ON ILX SOUNDING CLIMATOLOGY FOR MID-MARCH. DEEP MOIST-ADIABATIC
LAPSE RATES ALSO APPEAR TO YIELD SOME WEAK ELEVATED CAPE ACROSS
THE SOUTHEAST PORTION OF THE CWA AND HAVE INCLUDED SLIGHT CHANCE
FOR THUNDER ACROSS ABOUT THE SOUTHERN TIER OR SO OF CWA COUNTIES
FROM AFTER MIDNIGHT TONIGHT INTO SUNDAY.
TEMPS REACHED THE UPPER 50S/LOW 60S AWAY FROM LAKE MICHGAN THIS
AFTERNOON THOUGH CLOUD COVER HAS LIMITED THE CLIMB SOMEWHAT. CLOUD
COVER AND INCREASING LOW LEVEL DEW POINT TEMPS SHOULD KEEP MIN
TEMPS TONIGHT IN THE 40S MOST AREAS AND AROUND 50 FAR SOUTH...AND
DESPITE EXTENSIVE CLOUD COVER AND RAIN ON SUNDAY...PURE ADVECTION
OF WARMER AIR MASS SHOULD RESULT IN TEMP AGAIN IN THE UPPER
50S/LOW 60S SOUTH. INCREASING EAST WINDS (10-20 MPH) WILL COMBINE
WITH THE CLOUDS AND RAIN TO KEEP THINGS COOLER NORTH OF THE LOW
LEVEL SURFACE WAVE AND BAROCLINIC REGION...WITH TEMPS FROM THE MID
40S ALONG THE LAKE TO THE LOWER 50S FARTHER INLAND IN LINE
GUIDANCE TRENDS.
RATZER
&&
.LONG TERM...
303 PM CST
SUNDAY NIGHT THROUGH SATURDAY...
MAIN FORECAST CONCERNS/CHALLENGES ARE WITH LINGERING PRECIP
CHANCES SUNDAY NIGHT INTO MONDAY MORNING AND THEN WITH RETURNING
CHANCES FOR SHOWERS AND THUNDERSTORMS LATE MONDAY NIGHT INTO
TUESDAY AFTERNOON/EVENING...WITH THE POSSIBILITY OF ISOLATED
STRONG TO SEVERE THUNDERSTORMS DURING THAT TIME.
A WET START TO THE PERIOD IS STILL APPEARING LIKELY SUNDAY NIGHT.
CYCLONIC FLOW IN PLACE WITH MID LEVEL ENERGY TRAVERSING THIS FLOW
ALONG WITH SLOWLY MOVING SURFACE REFLECTION LOOK TO STILL PROVIDE
PERIODIC RAIN SHOWERS SUNDAY NIGHT. DID MAINTAIN LIKELY POPS FOR
THE AREA IN THE EVENING BUT SLOWLY DECREASE FROM WEST TO EAST
OVERNIGHT INTO EARLY MONDAY MORNING AS THIS SYSTEM BEGINS TO
DEPART TO THE EAST/NORTHEAST. FORECAST SOUNDINGS DO INDICATE SOME
WEAK INSTABILITY IN PLACE FOR THE FAR SOUTHERN CWA IN THE EVENING
AND THIS SEEMS REASONABLE GIVEN THAT LOCATION WILL STILL LIKELY BE
IN AN AXIS OF HIGHER MOISTURE CONTENT AIR. SO HAVE INCLUDED
MENTION OF SLIGHT CHANCE THUNDER MAINLY FOR THE INDIANA COUNTIES
SOUTH OF THE KANKAKEE RIVER. ANY THUNDER CHANCES QUICKLY DIMINISH
LATER IN THE NIGHT WITH THE ARRIVAL OF DRIER AIR AND WEAKENING
FORCING. CONTINUE THE LOWERING TREND WITH POPS ON MONDAY AS THIS
SYSTEM FURTHER DEPARTS. HOWEVER...THERE DOES APPEAR TO BE A
POSSIBILITY FOR SOME ISOLATED TO SCATTERED SHOWER DEVELOPMENT
ALONG THE BACK SIDE OF THIS SYSTEM WITH SOME WEAK LARGE SCALE
ASCENT AND FORCING ALONG DEPARTING BOUNDARY. DO LEAVE SOME CHANCE
POPS IN THE MORNING BUT GO MAINLY DRY IN THE AFTERNOON.
AFTER LIKELY DRY CONDITIONS IN THE AFTERNOON AND A PORTION OF THE
EVENING ON MONDAY...DO BRING BACK SLIGHT CHANCE POPS ACROSS NORTH
CENTRAL ILLINOIS AND THEN CHANCE POPS AFTER MIDNIGHT. APPROACHING
SYSTEM TAKING SHAPE OVER THE PLAINS WILL ALLOW BACKING LOW/MID
LEVEL FLOW TO INCREASE DURING THIS NIGHT. AS THIS OCCURS...WAA
LOOKS TO RAMP UP WITH AT LEAST SOME ISOLATED SHOWER DEVELOPMENT
ALONG THIS WAA AXIS. GUIDANCE PRETTY CONSISTENT WITH INCREASING
INSTABILITY ALSO DURING THIS PERIOD...AND SO HAVE INCLUDED SLIGHT
CHANCE THUNDER GIVEN THIS SIGNAL AND PATTERN.
MORNING GUIDANCE COMING IN FAIRLY CONSISTENT WITH ONE ANOTHER ON
THE NEXT SYSTEM TO LIKELY IMPACT THE REGION ON TUESDAY. FORECAST
GUIDANCE STILL ADVERTISING AN UPPER LEVEL TROUGH BECOMING HIGHLY
AMPLIFIED OVER THE PLAINS DURING THE DAY TUESDAY...WHILE UPPER
LEVEL JET STREAK OF AT LEAST 120KT SWINGS THROUGH THE REGION. MID
LEVEL FLOW/ENERGY IS ALSO APPEARING RATHER ROBUST WITH MID LEVEL
FLOW OF AROUND 100KT BECOMING POSSIBLE...AND WITH GUIDANCE
INDICATING A STOUT VORT MAX TO PUSH THROUGH THE REGION IN THE LATE
AFTERNOON AND EARLY EVENING. GROWING MORE CONCERNED FOR
THUNDERSTORM CHANCES ACROSS MUCH OF THE CWA DURING THIS TIME
ESPECIALLY AS A WARM/MOIST ENVIRONMENT ADVECTS NORTH OUT AHEAD OF
THIS SYSTEM. IN REGARDS TO MOISTURE RETURN...MODEL CONSENSUS IS
STILL INDICATING MODEST MOISTURE RETURN DURING THE DAY TUESDAY BUT
WITH SOME PIECES OF GUIDANCE INDICATING A LITTLE MORE AGGRESSIVE
RETURN OF MOISTURE TO THE AREA. IN THIS SCENARIO...INSTABILITY
INCREASES SIGNIFICANTLY WITH THE THREAT OF THUNDERSTORMS AND EVEN
STRONG TO SEVERE THUNDERSTORM DEVELOPMENT LIKELY INCREASING.
HOWEVER...NOT COMPLETELY SOLD ON THIS SOLUTION QUITE YET AND HAVE
GONE WITH MORE OF A CONSERVATIVE APPROACH. EVEN IN THIS
CONSERVATIVE APPROACH...THIS MODEST MOISTURE RETURN COULD STILL
YIELD WEAK INSTABILITY IN UPWARDS OF 500-1000 J/KG. GIVEN THIS
HIGHLY DYNAMIC SYSTEM AND EXPECTED STRONG KINEMATIC FIELD...EVEN
THIS POSSIBLE INSTABILITY IN THE PRESENCE OF THESE FEATURES COULD
ALLOW FOR AT LEAST SOME ISOLATED STRONG TO SEVERE THUNDERSTORMS.
STILL A LITTLE EARLY TO GATHER ANY STRONG CONFIDENCE ON EXACTLY
HOW TUESDAY WILL UNFOLD. HOWEVER...THIS PERIOD WARRANTS CLOSE
MONITORING FOR THIS THUNDERSTORM POTENTIAL.
RODRIGUEZ
&&
.AVIATION...
FOR THE 06Z TAFS...
WDLY SCATTERED -SHRA STILL EXPECTED THROUGH THE OVERNIGHT HOURS
WITH MORE OF AN UPTICK IN COVERAGE OF SHOWERS EXPECTED SUNDAY
MORNING...LIKELY BUILDING INTO MORE OF A STEADY RAIN BY MID-LATE
MORNING SUNDAY. RAIN SHOULD BEGIN TO TAPER OFF TO MORE OF A LIGHT
RAIN OR MORE LIKELY DRIZZLE BY LATE AFTERNOON INTO SUNDAY EVENING.
VFR CIGS WILL CONTINUE TO STEADILY LOWER OVERNIGHT...LIKELY TO
MVFR EARLY SUNDAY MORNING THEN QUICKLY DETERIORATING TO IFR SUNDAY
MORNING. CONTINUED RAIN/MOISTENING OF THE LOW LEVELS COMBINED WITH
WINDS OFF THE STILL COLD LAKE SHOULD RESULT IN A LOW AND SHARP
INVERSION WITH CIGS LIKELY BUILDING DOWN TO LIFR IN THE AFTERNOON.
GUIDANCE AND SYNOPTIC CLIMO BOTH SUGGEST POTENTIAL FOR VLIFR
CIGS/VSBY SUNDAY EVENING WITH DRIZZLE AND FOG CONTINUING.
GENERALLY STUCK CLOSE TO MAV/MET GUIDANCE FOR CIGS/VSBY SUNDAY
AFTERNOON AND NIGHT WHICH DOES BRING CONDITIONS CLOSE TO THE DECK.
GUIDANCE WAS A BIT MORE OPTIMISTIC AT MDW...SO KEPT THEM A BIT
HIGHER FOR NOW...BUT CONFIDENCE IS LOW AND WILL NEED TO BE
WATCHED. AT ORD...THE TOWER ENDS UP IN THE CIGS AT 200FT WHICH
TYPICALLY LEADS TO TOWER VSBY OF 1/2SM TO 1/4SM SO FELT MORE
COMFORTABLE BRINGING ORD TO NEAR THE DECK SUNDAY EVENING.
CONFIDENCE IN LOW CIGS/VSBY IS MEDIUM-HIGH SUNDAY EVENING THOUGH
CONFIDENCE IS LOWER IN PRECISELY HOW LOW IT GETS.
IZZI
&&
.MARINE...
252 PM CST
FEW CONCERNS IN THE NEAR TERM AS SURFACE HIGH PRESSURE CONTINUES
TO WEAKEN AND DRIFT EAST OVER THE CENTRAL/LOWER GREAT LAKES.
MODEST EAST WINDS WERE DEVELOPING ACROSS THE SOUTH END OF THE LAKE
IN RESPONSE TO A WEAK AREA OF LOW PRESSURE WHICH WAS DEVELOPING
ACROSS THE LOWER MISSISSIPPI AND MISSOURI VALLEYS...AND EAST WINDS
WILL CONTINUE TO INCREASE A BIT INTO SUNDAY ACROSS THE LAKE AS
THIS LOW LIFTS NORTHEAST INTO IL/IN BY EVENING. IT APPEARS AT THIS
TIME THAT THIS LOW WILL PASS JUST SOUTH OF THE LAKE SUNDAY NIGHT.
THE SURFACE PRESSURE PATTERN WILL THEN SLACKEN AGAIN INTO MONDAY
WITH LIGHT NORTH WINDS DEVELOPING BEHIND THE DEPARTING WEAK LOW.
A MORE POTENT LOW PRESSURE SYSTEM IS STILL BEING WATCHED FOR THE
MIDDLE OF NEXT WEEK...WITH FORECAST MODELS STILL DEVELOPING A DEEP
SURFACE LOW OVER THE WESTERN LAKES OR UPPER MISSISSIPPI VALLEY BY
LATE TUESDAY AND MOVING THE LOW ACROSS THE LAKES THROUGH THURSDAY.
THIS WOULD STILL SUPPORT THE POTENTIAL FOR STRONG WEST-SOUTHWEST
WINDS/GALES BY WEDNESDAY AS COOLER AIR WRAPS AROUND THE SYSTEM.
THERE IS STILL AMPLE SPREAD BETWEEN MODEL SOLUTIONS AT THIS TIME
HOWEVER... MAKING CONFIDENCE IN THE DETAILS OF THE WIND FIELD
FAIRLY LOW.
RATZER
&&
.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
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
809 PM EDT MON MAR 14 2016
.SYNOPSIS...
ISSUED AT 805 PM EDT MON MAR 14 2016
FOG MAY EXPAND ONCE AGAIN ACROSS MUCH OF THE AREA LATE TONIGHT
INTO TUESDAY MORNING. THERE REMAINS A RISK FOR ISOLATED SEVERE
THUNDERSTORMS LATE TUESDAY AFTERNOON INTO TUESDAY EVENING. LOWS
TONIGHT WILL BE IN THE 40S WITH HIGHS ON TUESDAY REBOUNDING INTO
THE MIDDLE 60S TO AROUND 70.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 310 PM EDT MON MAR 14 2016
NEAR TERM...
WEAK INSTABILITY AND STRONG LOW LEVEL CONVERGENCE IN VICINITY OF
SFC LOW OVER DAYTON HAS ALLOWED FOR SEVERAL BRIEF BUT AT TIMES
INTENSE CIRCULATIONS ACROSS PORTIONS OF WEST CENTRAL OHIO WITH AT
LEAST 1 TORNADO CONFIRMED. A THUNDER THREAT REMAINS IN PLACE
MAINLY ALONG AND EAST OF A VAN WERT TO DESHLER OHIO LINE THROUGH
00Z AS THE SFC LOW CONTINUES TO MOVE SLOWLY NE AND INSTABILITY
AXIS SHIFTS INTO THIS AREA. EXPANDED CATEGORICAL POPS SOMEWHAT TO
CAPTURE MAIN AREA OF PRECIP. RADAR TRENDS WILL BE MONITORED WITH
SUBTLE FEATURES AS THEY MOVE INTO PORTIONS OF NW OHIO.
TONIGHT INTO TUESDAY MORNING... FOCUS WILL SHIFT TO POTENTIAL FOR
ANY CLEARING AND FOG DEVELOPMENT ACROSS THE AREA. LOW LEVEL
MOISTURE WILL REMAIN TRAPPED BENEATH STRENGTHENING INVERSION WITH
WINDS GOING LIGHT. EXPECTING AREAS OF FOG TO FORM ACROSS THE AREA.
MAIN CHALLENGE WILL BE RISK FOR DENSE FOG...WITH GREATEST
CONCENTRATION IN AREAS THAT SEE SOME MIXING OF LOW CLOUDS. HI RES
MODELS SUGGEST THIS TO BE MAINLY NW AREAS. HAVE WENT FROM PATCHY
FOG TO AREAS OF FOG IN ZONES THROUGH 12Z TUES AND PASS TO EVENING
SHIFT TO MONITOR TRENDS.
TUESDAY AFTERNOON INTO TUESDAY NIGHT... WARM FRONT WILL QUICKLY
MOVE NORTH ACROSS MOST IF NOT ALL THE AREA TUESDAY AFTERNOON INTO
EARLY TUESDAY EVENING. DRY CONDITIONS GENERALLY EXPECTED THROUGH
THE AFTERNOON TUESDAY ALTHOUGH CAN`T RULE OUT A STRAY SHOWER OR
STORM IN THE EAST MID TO LATE AFTERNOON AS NOSE OF INCREASED
INSTABILITY BEGINS TO ARRIVE. MAIN FOCUS WILL BE TUESDAY EVENING
AS HI RES MODELS ALL SHOWING SUPERCELL DEVELOPMENT ACROSS CENTRAL
ILLINOIS TUES AFTERNOON WHICH PROGRESSES EAST ON THE 00Z TO 06Z
WEDS TIME FRAME. OBVIOUSLY NOT THE BEST TIME FRAME FOR MID MARCH
TO GET SEVERE WEATHER...HOWEVER GIVEN WHAT SHOULD BE WELL
ESTABLISHED CONVECTION AND INCREASING LOW LEVEL SHEAR AND
INSTABILITY...AT LEAST AN ISOLATED THREAT FOR SEVERE WEATHER
REMAINS. MAIN THREAT LIKELY TO BE LARGE HAIL GIVEN MUCAPE VALUES
OF 1000 TO POTENTIALLY 2000 J/KG BUT LITTLE/NO SFC BASED CAPE.
SLIGHT RISK ACROSS THE ENTIRE AREA APPEARS REASONABLE ALTHOUGH
GREATEST THREAT LIKELY TO BE WEST OF US 131/SR 13 IN THE EVENING
WITH A QUICK DECREASING TREND EASTWARD.
&&
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 310 PM EDT MON MAR 14 2016
PRIMARY FCST ISSUE THIS PD IS EVOLUTION OF DEEP CUTOFF ACRS THE
LAKES. 12Z GUIDANCE SIMILAR IN KIND TO PRIOR SOLUTIONS W/WW
ELONGATION OF MID LVL TROUGH AXIS AS SPRTG JET STREAK HEADS
THROUGH NEW ENGLAND THU NIGHT. THIS LEAVES BEHIND SOME VESTIGE OF
CYCLONIC FLW ALOFT AS MID LVL TROUGH SETTLES SOUTH INTO FRI BFR
REINVIGORATING INTO SAT AS WHATS LEFT SPINS OUT EWD ACRS THE OH
VALLEY. PRIOR GRIDS REFLECTED A SOMEWHAT STGR SOLUTION ALOFT BUT
12Z SOLUTIONS AS A WHOLE DRIER THU-FRI AND WILL FOLLOW OTHER
OFFICES IN BACKING OFF PRIOR POPS.
THEREAFTER SOLUTION SCOPE WRT EWD PROGRESSION/PLACEMENT OF
REMNANTS OF THIS SYS UNCERTAIN. HWVR ENOUGH OF A MODEL CONSENSUS
PRESENTS TO HOLD W/PREV POPS SAT-SUN. OTRWS COOLING TREND BACK TO
SEASONABLE TEMPS XPCD BEYOND WED.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 800 PM EDT MON MAR 14 2016
MOISTURE TRAPPED BELOW SUBSTANTIAL 925MB SUBSIDENCE INVERSION PER
LATEST RUC13 POINT SOUNDINGS ALONG WITH LATE DAY PARTIAL CLEARING
SETTING THE STAGE FOR POTENTIAL WIDESPREAD FOG/DENSE AT TIMES
ACROSS NORTHERN INDIANA LATE TONIGHT/DAYBREAK TUE WITH PREDOMINANT
IFR VSBYS IN BR AND TEMPO LIFR FG. WHILE SOME LOWER DPS ADVECTING
INTO KSBN...STRONG POCKETS OF RADIATIONAL COOLING SHOULD MORE THAN
OFFSET FEEBLE/LATE DAY SCOUR. MORE PESSIMISTIC AS WELL AT KFWA
WHERE LAGGED HIR DPS RESIDE. ANTICIPATE SUBSTANTIAL IMPROVEMENT IN
13-15 UTC TIMEFRAME TO VFR AS DEEPER MIXING COMMENCES.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...MURPHY
SHORT TERM...FISHER
LONG TERM...T
AVIATION...MURPHY
VISIT US AT WW.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 QUAD CITIES IA IL
652 PM CDT MON MAR 14 2016
...AVIATION UPDATE...
.SYNOPSIS...
ISSUED AT 330 PM CDT MON MAR 14 2016
18Z SFC DATA HAS AN IMPLIED FRONTAL BOUNDARY FROM NEAR KSUX TO NEAR
KEVV. DEW POINTS WERE IN THE 40S FROM THE GREAT LAKES INTO THE UPPER
MIDWEST WITH 50S FROM THE OHIO VALLEY INTO MID MISSISSIPPI VALLEY
AND DOWN TO THE GULF.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 330 PM CDT MON MAR 14 2016
SOME HOLES HAVE DEVELOPED IN THE LOW CLOUDS ACROSS THE AREA WHICH
HAS ALLOWED SOME BRIEF PEEKS OF SUN THIS AFTERNOON. RADAR TRENDS
SHOW THE SHOWERS NEAR KCID ARE RAPIDLY FALLING APART. THUS DRY
CONDITIONS ARE EXPECTED THROUGH SUNSET.
AFTER SUNSET...DRY CONDITIONS WILL CONTINUE THROUGH MID EVENING.
BETWEEN 10 PM AND 1 AM THERE MAY OR MAY NOT BE SOME ISOLATED SHOWERS
DEVELOP NORTH AND WEST OF A LINE FROM DUBUQUE TO GRINNELL.
INTERNALLY...MOST OF THE MODELS AND TRENDS FROM THE RAP ARE
SUGGESTING DRY CONDITIONS THROUGH MIDNIGHT.
BY MIDNIGHT...THE MODELS LOOSELY AGREE THAT A THUNDERSTORM COMPLEX
WILL HAVE DEVELOPED ALONG THE MO/KS BORDER UP INTO FAR SOUTHEAST
NEBRASKA. THIS THUNDERSTORM COMPLEX WILL THEN MOVE EAST NORTHEAST
AND ARRIVE IN EASTERN IOWA PRIOR TO SUNRISE WEDNESDAY. THIS COMPLEX
WILL STRATIFY OUT DUE TO MORE STABLE AIR ACROSS THE AREA BUT SOME
THUNDERSTORMS ARE EXPECTED DUE TO UNSTABLE AIR ALOFT. THE
POSSIBILITY DOES EXIST THAT SOME THUNDERSTORMS MAY PRODUCE HAIL THAT
COULD APPROACH SEVERE LIMITS.
THE DECAYING COMPLEX WILL MOVE ACROSS THE AREA DURING THE MORNING
THAT WILL PRODUCE BOUNDARIES FOR NEW CONVECTION TUESDAY AFTERNOON.
TUESDAY AFTERNOON...THE MAIN COLD FRONT WILL SWEEP THROUGH THE AREA.
DIURNAL HEATING COMBINED WITH THE FRONT AND BOUNDARIES FROM THE
OVERNIGHT CONVECTION WILL ALLOW NEW THUNDERSTORMS TO RAPIDLY DEVELOP.
SEVERAL FACTORS ARE IN PLACE FOR THE DEVELOPMENT OF SEVERE STORMS ON
TUESDAY. THE QUESTION IS HOW EACH COMES TOGETHER. TWO IMPORTANT
FACTORS WILL BE THE TIMING OF THE COLD FRONT AND DIURNAL HEATING.
THE WAY IT LOOKS RIGHT NOW...AREAS ALONG/EAST OF THE MISSISSIPPI
HAVE SLIGHTLY BETTER CHANCES OF SEEING SEVERE STORMS TUESDAY
AFTERNOON.
.LONG TERM...(TUESDAY NIGHT THROUGH NEXT MONDAY)
ISSUED AT 330 PM CDT MON MAR 14 2016
TUESDAY NIGHT AND WEDNESDAY...12Z RUN MODELS SHEAR OUT VIGOROUS
NEGATIVELY TILTED WAVE ACRS WI INTO THE WESTERN GRT LKS THIS
PERIOD...BUT IN VARYING STRENGTHS. WILL WALK OUT LINGERING STRONG TO
POSSIBLY SEVERE BROKEN LINE OF STORMS OUT OF NORTHWESTERN IL BY
01Z...IF THEY DON/T EXIT EARLIER THAN THAT. THEN THE MODELS
DIVERGE...WITH THE 12Z ECMWF CONTINUING TO BE THE MOST DYNAMICAL IN
HANDLING THE LOW WITH THE SFC FEATURE DEEPENING TO UNDER 990 MB ACTS
CENTRAL WI BY WED MORNING. THE EURO PRODUCES STRONG WRAP AROUND
SHOWERS AND EMBEDDED ADDITIONAL CONVECTION AND THUS IS ADVERTISING
OVER AN INCH OF RAIN TUE EVENING IN MUCH OF EST CENTRAL IA NORTH OF
I80 AND WEST OF THE MS RVR. IT THEN CONTINUES WRAP-AROUND ALONG AND
NORTH OF I80 WITH ANOTHER 0.30-0.60+ OF AN INCH OF QPF NORTH OF THE
HWY 30 CORRIDOR FROM 06Z-12Z WED...WITH PARAMETERS COOLING TO NEAR
RAIN-SNOW MIX OR ALL WET SNOW ALONG HWY 20 LATE TUE NIGHT. MOST OF
THE OTHER 12Z MODEL SOLUTIONS NOT NEARLY SO BULLISH AND AFTER SOME
WRAP AROUND SHOWERS TUE EVENING BEHIND THE MAIN EXITING CONVECTIVE
LINE...THEY TRANSITION TO MAINLY DRY AFTER 06Z WED OR CLIPPING
NORTHWESTERN IL WITH SHOWERS/RAIN THROUGH 09Z WED BEFORE SWEEPING
OFF THE PRECIP TO THE EAST. FOR NOW WILL TAKE A BLEND THAT PRODUCES
A QUARTER OF AN INCH TO FOUR TENTHS OF AN INCH OF WRAP AROUND RAIN
ACRS THE NORTHEASTERN THIRD TO HALF OF THE DVN CWA BY 12Z WED
MORNING.
WED THE CWA TO CONTINUE TO BE IN TIGHT CYCLONIC GRADIENT OFF DEEP
CYCLONE IN EASTERN WI...WEST WINDS MAY GUST WELL OVER 30 MPH AND NOT
BE THAT FAR OFF ADVISORY LEVELS FOR SUSTAINED SPEEDS ESPECIALLY
NORTH OF I80. WITH PLENTY OF DRIED VEGETATION AND AFTERNOON RH/S
DIPPING INTO THE LOWER 40S TO 30 PERCENT RANGE...A GRASSLAND FIRE
DANGER MAY EVOLVE BY WED AFTERNOON. A LOW CHC FOR MORE WRAP AROUND
LIGHT RAIN ALONG AND NORTH OF HWY 20 ON WED. IF WRAP AROUND PRECIP
MAINTAINS IN THE NORTHERN CWA INTO WED NIGHT-EARLY THU MORNING BY
BLOCKED GRT LKS CYCLONE...SOME PRECIP TYPE ISSUES MAY HAVE TO BE
DEALT WITH. BUT MORE MODELS ARE DRY WED NIGHT THAN ARE ADVERTISING
THIS POTENTIAL.
THURSDAY AND FRIDAY... BLOCKED GRT LKS CYCLONE WILL LOOK TO FILL
SOME...THEN DRIFT BACK SOUTHWARD AS AN UPPER TROF DOWN THE WESTERN
GRT LKS AND UPPER MS RVR VALLEY. IF THIS PANS OUT...THEN POSSIBLY
SOME SHOWER ACTIVITY MAY DEVELOP IN THE VCNTY OF THIS FEATURE BY THU
AFTERNOON ESPECIALLY ALONG AND NORTH OF I80. EXPECT IF THIS
OCCURS... ANY LINGERING SHOWERS TO DIURNALLY WANE THU NIGHT. BUT IF
THEY PERSIST LONGER INTO THE NIGHT THAN CURRENTLY EXPECTED...PRECIP
TYPE ISSUES WILL POPS UP AGAIN WITH RAIN-SNOW MIX OR EVEN ALL WET
SNOW SHOWERS ESPECIALLY NORTH OF I80. THE SOUTHWARD DRIFTING TROF
WILL KEEP THE CHC FOR ISOLATED TO WDLY SCTRD SHOWERS GOING FRI INTO
FRI NIGHT...ALTHOUGH THE NEW 12Z ECMWF AS BACKED OFF OF THIS
POTENTIAL AND IS MAINLY DRY INTO EARLY SAT MORNING. AGAIN ANY
LINGERING NOCTURNAL PRECIP MAY HAVE A CHANCE TO GO INTO A WINTRY MIX
ESPECIALLY NORTH OF I80. HIGHS THU IN THE MID 40S NORTH...TO THE MID
50S IN THE SOUTH...THU NIGHT LOWS WELL DOWN IN THE 30S ESPECIALLY
WITH ANY CLOUD DECREASE. FRI HIGHS CONTINUE TO TREND COOLER IN THE
40S TO AROUND 50.
SATURDAY THROUGH NEXT MONDAY...MUCH WILL DEPEND ON PLACEMENT OF
DEVELOPING COLD CORE UPPER TROF THIS PERIOD...WITH HIGHS POSSIBLY
HELD WELL DOWN IN THE 40S BOTH SATURDAY AND SUNDAY. SCTRD SNOW OR
RAIN SHOWERS POSSIBLE UNDER THIS FEATURE ON SAT AS WELL WITH SUCH
COLD VERTICAL PROFILES JUST ALOFT. THE 12Z GFS IS DRY ON SUNDAY WITH
UPPER TROF AXIS TO THE EAST OF THE AREA...WHILE THE ECMWF MAINTAINS
SOME COLD SHOWERS ESPECIALLY EAST OF THE MS RVR. WILL KEEP A DRY
FCST FOR NOW THROUGH MON. LONGER RANGE INDICATIONS SHOW A WARMING
TREND EARLY NEXT WEEK...BUT THE LEADING EDGE MAY BE ACCOMPANIED BY A
LEAD CLIPPER WITH A PRECIP WING EITHER MON OR EARLY TUE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 647 PM CDT MON MAR 14 2016
VFR TO MOSTLY VFR CONDITIONS THIS EVENING AT ALL TERMINALS AHEAD OF
A DEVELOPING STORM SYSTEM IN THE PLAINS. SOUTHEAST WINDS OF 5 TO 10
KTS NEXT 24 HOURS. AFTER 15/08Z...CLOUDS TO INCREASE WITH PATCHY MVFR
CONDITIONS IN RAINSHOWERS AND ISOLATED STORMS UNTIL 15/15Z. MOSTLY
VFR CONDITIONS WITH ISOLATED SHOWERS AND STORMS UNTIL 15/21Z THEN
AREAS OF SHOWERS AND STORMS WITH MVFR AND POSSIBLY IFR CONDITIONS
WITH SOME STRONG STORMS OR SEVERE STORMS WITH HAIL THE MAIN THREAT
THROUGH 16/00Z.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...08
SHORT TERM...08
LONG TERM...12
AVIATION...NICHOLS
AREA FORECAST DISCUSSION
National Weather Service Dodge City KS
1210 PM CDT SUN MAR 13 2016
...Updated Synopsis and Aviation Discussion...
.SYNOPSIS...
ISSUED AT 1208 PM CDT SUN MAR 13 2016
At 12z Sunday a 500mb low was located over southwest Oklahoma,
and a 700mb and 500mb deformation zone was located north northwest
of this upper low across western Kansas. The convection that
occurred earlier this morning was located east of this 700mb to
500mb deformation zone. Further west an upper level trough was
located just off the west coast with at +100 knot 250mb jet
positioned at the based of this upper trough.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 330 AM CDT SUN MAR 13 2016
A deep, compact upper level cyclone was moving into the western
Texas Panhandle early this morning and should move across Oklahoma
into western Arkansas by evening. Temperatures are quite cold in
the center of the upper level cyclone with -25 C at H5 on the ABQ
sounding at 00Z. A cluster of thunderstorms east and north of the
upper level cold pool had propagated into the Oklahoma Panhandle
and western Oklahoma by 07Z, but convective elements were tending
to weaken as they moved away from the cold pool into more stable
air in Kansas. The northern part of the convective cluster
probably will skirt the southern border of Kansas, but the better
chance for significant precipitation will be farther south.
A weak upper level vorticity maximum developed in northwest
Kansas Saturday evening, and satellite imagery and radar suggested
the presence of a weak closed cyclone west of HLC at 07Z. This
upper level cyclone likely will move east during the day and
support an area of showers and thunderstorms across northern
Kansas. POPs in the grids will be modified to indicate higher
chances for measurable rain north and south of Dodge City with a
minimum along the Arkansas River Valley.
Weak upslope flow and nearly saturated air in the lower few
thousand feet of the atmosphere will support extensive stratus
tonight and Sunday morning. The HRR and RAP develop patchy dense
fog early this morning, but hydrolapses on model soundings are
more supportive of low clouds than dense fog. Some restriction in
visibilities can be expected toward sunrise, but it appears likely
that visibilities will remain above dense fog criteria.
A surface trough will propagate across western Kansas with the
upper level trough, and low level winds will become northwest
across all of western Kansas by mid afternoon. Drier air and
downslope flow will result in clearing skies and warm temperatures
this afternoon. Temperatures will be cooler in central Kansas
where cloudiness will be slower to clear out. Light winds and
mostly clear skies tonight will support good radiational cooling,
but the atmosphere is so warm that lows still will be well above
seasonal averages.
.LONG TERM...(Monday THROUGH Saturday)
ISSUED AT 330 AM CDT SUN MAR 13 2016
An anomalously strong East Asian jet extending across the Pacific
is impinging on the northwestern United States, and a large area
of exceedingly cold air aloft is moving into the Pacific Northwest
early today. Pressures will fall in the lee of the Rockies Monday,
and a plume of very warm air will cover western Kansas with H8
temperatures above 20C from Dodge City west to Colorado. Highs
should rise into the 80s at most locations. As the Pacific
Northwest trough digs into the northern Plains Tuesday, a cold
front will move across Kansas Monday night. Strong northwest low
level winds and tanking dewpoints will result in very active fire
behavior Tuesday. Temperatures Tuesday will be about 15 degrees
lower than on Monday but still above seasonal averages. Strong
radiational cooling with very dry air will allow temperatures to
fall below freezing for the first time in several days Tuesday
night. Wednesday should be fairly quiet with an upper level
cyclone centered in the Great Lakes and nearly zonal flow aloft in
the Central Plains. Highs should be in the upper 50s and lower
60s.
Strong cyclogenesis off the coast of Asia Monday will start to
buckle the East Asian jet, and downstream cyclogenesis near 160W
on Wednesday will result in development of a sharp ridge in the
eastern Pacific. A deep upper level trough will dig into the
northern Rockies Thursday and move across the Central Plains
Friday and Saturday. Surface anticylogenesis in western Canada
downstream from the sharp upper level ridge in western Canada will
result in evolution of a cold air mass that will plunge into the
central part of the country Thursday night and Friday. Synoptic
scale details differ between the ECMWF and GFS, but the
operational runs of both models suggest that measurable snowfall
may occur in Kansas Friday and/or Saturday. Ensembles from the GFS
and GEM show quite a bit of spread, so details of the event are
uncertain. Regardless of the synoptic scale details, it is almost
certain that temperatures will be cold enough to damage any early
plant growth that has occurred in the extended period of anomalous
warmth in February and early March. Lows in the teens are very
possible if the sky clears over a snow pack. The cold period will
be short lived; zonal flow and much warmer temperatures will
return by early next week.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z Monday AFTERNOON)
ISSUED AT 1208 PM CDT SUN MAR 13 2016
Skies will clear from west to east this afternoon as an upper
level ridge axis begins to build into western Kansas. Winds today
will be northwest at around 10 knot. Tonight wind speeds will fall
back to less than 10 knots under mostly clear skies. A brief
period of MVFR cloud cover will be possible at DDC and HYS for the
next few hours. There even my be a brief shower around the HYS
terminal through 20z Sunday.
&&
.FIRE WEATHER...
ISSUED AT 330 AM CDT SUN MAR 13 2016
Temperatures in the 80s and low dewpoints Monday will result in
relative humidities around 15 percent. Winds will be relatively
light, but deep mixing in the afternoon may result in gusts in
excess of 25 mph. Very active fire behavior can be expected. A
cold front will move through western Kansas Monday night, followed
by strong northwest winds and dewpoints in the teens on Tuesday.
Relative humidities likely will fall to near 15 percent Tuesday
afternoon, and a fire weather headline may be required.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 70 41 80 37 / 20 0 0 0
GCK 72 37 80 35 / 20 0 0 10
EHA 73 40 82 40 / 0 0 0 0
LBL 72 38 81 38 / 0 0 0 0
HYS 68 41 79 41 / 40 0 10 20
P28 67 44 81 44 / 30 10 0 0
&&
.DDC Watches/Warnings/Advisories...
Fire Weather Watch from Monday afternoon through Monday evening
for KSZ061-062-074-075-084-085.
&&
$$
SYNOPSIS...Burgert
SHORT TERM...Ruthi
LONG TERM...Ruthi
AVIATION...Burgert
FIRE WEATHER...Ruthi
AREA FORECAST DISCUSSION
National Weather Service Dodge City KS
646 AM CDT SUN MAR 13 2016
...Updated Aviation Section...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 330 AM CDT SUN MAR 13 2016
A deep, compact upper level cyclone was moving into the western
Texas Panhandle early this morning and should move across Oklahoma
into western Arkansas by evening. Temperatures are quite cold in
the center of the upper level cyclone with -25 C at H5 on the ABQ
sounding at 00Z. A cluster of thunderstorms east and north of the
upper level cold pool had propagated into the Oklahoma Panhandle
and western Oklahoma by 07Z, but convective elements were tending
to weaken as they moved away from the cold pool into more stable
air in Kansas. The northern part of the convective cluster
probably will skirt the southern border of Kansas, but the better
chance for significant precipitation will be farther south.
A weak upper level vorticity maximum developed in northwest
Kansas Saturday evening, and satellite imagery and radar suggested
the presence of a weak closed cyclone west of HLC at 07Z. This
upper level cyclone likely will move east during the day and
support an area of showers and thunderstorms across northern
Kansas. POPs in the grids will be modified to indicate higher
chances for measurable rain north and south of Dodge City with a
minimum along the Arkansas River Valley.
Weak upslope flow and nearly saturated air in the lower few
thousand feet of the atmosphere will support extensive stratus
tonight and Sunday morning. The HRR and RAP develop patchy dense
fog early this morning, but hydrolapses on model soundings are
more supportive of low clouds than dense fog. Some restriction in
visibilities can be expected toward sunrise, but it appears likely
that visibilities will remain above dense fog criteria.
A surface trough will propagate across western Kansas with the
upper level trough, and low level winds will become northwest
across all of western Kansas by mid afternoon. Drier air and
downslope flow will result in clearing skies and warm temperatures
this afternoon. Temperatures will be cooler in central Kansas
where cloudiness will be slower to clear out. Light winds and
mostly clear skies tonight will support good radiational cooling,
but the atmosphere is so warm that lows still will be well above
seasonal averages.
.LONG TERM...(Monday THROUGH Saturday)
ISSUED AT 330 AM CDT SUN MAR 13 2016
An anomalously strong East Asian jet extending across the Pacific
is impinging on the northwestern United States, and a large area
of exceedingly cold air aloft is moving into the Pacific Northwest
early today. Pressures will fall in the lee of the Rockies Monday,
and a plume of very warm air will cover western Kansas with H8
temperatures above 20C from Dodge City west to Colorado. Highs
should rise into the 80s at most locations. As the Pacific
Northwest trough digs into the northern Plains Tuesday, a cold
front will move across Kansas Monday night. Strong northwest low
level winds and tanking dewpoints will result in very active fire
behavior Tuesday. Temperatures Tuesday will be about 15 degrees
lower than on Monday but still above seasonal averages. Strong
radiational cooling with very dry air will allow temperatures to
fall below freezing for the first time in several days Tuesday
night. Wednesday should be fairly quiet with an upper level
cyclone centered in the Great Lakes and nearly zonal flow aloft in
the Central Plains. Highs should be in the upper 50s and lower
60s.
Strong cyclogenesis off the coast of Asia Monday will start to
buckle the East Asian jet, and downstream cyclogenesis near 160W
on Wednesday will result in development of a sharp ridge in the
eastern Pacific. A deep upper level trough will dig into the
northern Rockies Thursday and move across the Central Plains
Friday and Saturday. Surface anticylogenesis in western Canada
downstream from the sharp upper level ridge in western Canada will
result in evolution of a cold air mass that will plunge into the
central part of the country Thursday night and Friday. Synoptic
scale details differ between the ECMWF and GFS, but the
operational runs of both models suggest that measurable snowfall
may occur in Kansas Friday and/or Saturday. Ensembles from the GFS
and GEM show quite a bit of spread, so details of the event are
uncertain. Regardless of the synoptic scale details, it is almost
certain that temperatures will be cold enough to damage any early
plant growth that has occurred in the extended period of anomalous
warmth in February and early March. Lows in the teens are very
possible if the sky clears over a snow pack. The cold period will
be short lived; zonal flow and much warmer temperatures will
return by early next week.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z Monday MORNING)
ISSUED AT 643 AM CDT SUN MAR 13 2016
Poor aviation weather will continue through the morning with
widespread LIFR/IFR ceiling and visibility at GCK, DDC, and to a
lesser degree HYS. Areas of dense fog around the GCK terminal will
persist through 15z. Once the upper low moves far enough east
into Oklahoma later today (early afternoon), drier air moving in
from Colorado behind the low will allow flight category to improve
to VFR at all locations, especially mid afternoon.
&&
.FIRE WEATHER...
ISSUED AT 330 AM CDT SUN MAR 13 2016
Temperatures in the 80s and low dewpoints Monday will result in
relative humidities around 15 percent. Winds will be relatively
light, but deep mixing in the afternoon may result in gusts in
excess of 25 mph. Very active fire behavior can be expected. A
cold front will move through western Kansas Monday night, followed
by strong northwest winds and dewpoints in the teens on Tuesday.
Relative humidities likely will fall to near 15 percent Tuesday
afternoon, and a fire weather headline may be required.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 70 42 80 41 / 20 10 0 0
GCK 72 39 80 38 / 10 0 0 10
EHA 73 41 82 39 / 10 0 0 0
LBL 72 39 81 38 / 10 0 0 0
HYS 68 42 79 42 / 30 10 10 20
P28 67 44 81 45 / 60 10 0 0
&&
.DDC Watches/Warnings/Advisories...
Fire Weather Watch from Monday afternoon through Monday evening
for KSZ061-062-074-075-084-085.
Dense Fog Advisory until 10 AM CDT this morning for KSZ063-075-
076-085-086.
&&
$$
SHORT TERM...Ruthi
LONG TERM...Ruthi
AVIATION...Umscheid
FIRE WEATHER...Ruthi
AREA FORECAST DISCUSSION
National Weather Service Dodge City KS
334 AM CDT SUN MAR 13 2016
...Updated Short Term, Long Term and Fire Weather Sections...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 330 AM CDT SUN MAR 13 2016
A deep, compact upper level cyclone was moving into the western
Texas Panhandle early this morning and should move across Oklahoma
into western Arkansas by evening. Temperatures are quite cold in
the center of the upper level cyclone with -25 C at H5 on the ABQ
sounding at 00Z. A cluster of thunderstorms east and north of the
upper level cold pool had propagated into the Oklahoma Panhandle
and western Oklahoma by 07Z, but convective elements were tending
to weaken as they moved away from the cold pool into more stable
air in Kansas. The northern part of the convective cluster
probably will skirt the southern border of Kansas, but the better
chance for significant precipitation will be farther south.
A weak upper level vorticity maximum developed in northwest
Kansas Saturday evening, and satellite imagery and radar suggested
the presence of a weak closed cyclone west of HLC at 07Z. This
upper level cyclone likely will move east during the day and
support an area of showers and thunderstorms across northern
Kansas. POPs in the grids will be modified to indicate higher
chances for measurable rain north and south of Dodge City with a
minimum along the Arkansas River Valley.
Weak upslope flow and nearly saturated air in the lower few
thousand feet of the atmosphere will support extensive stratus
tonight and Sunday morning. The HRR and RAP develop patchy dense
fog early this morning, but hydrolapses on model soundings are
more supportive of low clouds than dense fog. Some restriction in
visibilities can be expected toward sunrise, but it appears likely
that visibilities will remain above dense fog criteria.
A surface trough will propagate across western Kansas with the
upper level trough, and low level winds will become northwest
across all of western Kansas by mid afternoon. Drier air and
downslope flow will result in clearing skies and warm temperatures
this afternoon. Temperatures will be cooler in central Kansas
where cloudiness will be slower to clear out. Light winds and
mostly clear skies tonight will support good radiational cooling,
but the atmosphere is so warm that lows still will be well above
seasonal averages.
.LONG TERM...(Monday THROUGH Saturday)
ISSUED AT 330 AM CDT SUN MAR 13 2016
An anomalously strong East Asian jet extending across the Pacific
is impinging on the northwestern United States, and a large area
of exceedingly cold air aloft is moving into the Pacific Northwest
early today. Pressures will fall in the lee of the Rockies Monday,
and a plume of very warm air will cover western Kansas with H8
temperatures above 20C from Dodge City west to Colorado. Highs
should rise into the 80s at most locations. As the Pacific
Northwest trough digs into the northern Plains Tuesday, a cold
front will move across Kansas Monday night. Strong northwest low
level winds and tanking dewpoints will result in very active fire
behavior Tuesday. Temperatures Tuesday will be about 15 degrees
lower than on Monday but still above seasonal averages. Strong
radiational cooling with very dry air will allow temperatures to
fall below freezing for the first time in several days Tuesday
night. Wednesday should be fairly quiet with an upper level
cyclone centered in the Great Lakes and nearly zonal flow aloft in
the Central Plains. Highs should be in the upper 50s and lower
60s.
Strong cyclogenesis off the coast of Asia Monday will start to
buckle the East Asian jet, and downstream cyclogenesis near 160W
on Wednesday will result in development of a sharp ridge in the
eastern Pacific. A deep upper level trough will dig into the
northern Rockies Thursday and move across the Central Plains
Friday and Saturday. Surface anticylogenesis in western Canada
downstream from the sharp upper level ridge in western Canada will
result in evolution of a cold air mass that will plunge into the
central part of the country Thursday night and Friday. Synoptic
scale details differ between the ECMWF and GFS, but the
operational runs of both models suggest that measurable snowfall
may occur in Kansas Friday and/or Saturday. Ensembles from the GFS
and GEM show quite a bit of spread, so details of the event are
uncertain. Regardless of the synoptic scale details, it is almost
certain that temperatures will be cold enough to damage any early
plant growth that has occurred in the extended period of anomalous
warmth in February and early March. Lows in the teens are very
possible if the sky clears over a snow pack. The cold period will
be short lived; zonal flow and much warmer temperatures will
return by early next week.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z Monday NIGHT)
ISSUED AT 1150 PM CST SAT MAR 12 2016
A compact upper level cyclone centered along the Texas/New Mexico
border at 06Z will move across Oklahoma and reach western Arkansas
Sunday evening. Another subtle upper level trough extending from
northwest Kansas into northeast Oklahoma will move slowly into
eastern Kansas by evening. Scattered showers and areas of light
rain can be expected tonight across western Kansas with a few
lightning strikes near the upper level cold pool in southwest and
south central Kansas. A deep, moist air mass will persist, and
widespread stratus with ceilings from 010 to 020 lowering to
blo010 by 09Z can be expected. Visibilities will lower to 1-3 SM
in fog after 09Z. Showers will end from west to east Sunday
morning as the upper level cyclone continues to move east. A
surface trough will move across western Kansas today, and low
level winds will become west to northwest around 10 kts by early
afternoon. Stratus and fog will erode during the morning, and VFR
conditions can be expected by 18Z - 20Z.
&&
.FIRE WEATHER...
ISSUED AT 330 AM CDT SUN MAR 13 2016
Temperatures in the 80s and low dewpoints Monday will result in
relative humidities around 15 percent. Winds will be relatively
light, but deep mixing in the afternoon may result in gusts in
excess of 25 mph. Very active fire behavior can be expected. A
cold front will move through western Kansas Monday night, followed
by strong northwest winds and dewpoints in the teens on Tuesday.
Relative humidities likely will fall to near 15 percent Tuesday
afternoon, and a fire weather headline may be required.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 73 42 78 43 / 20 10 0 0
GCK 75 39 78 39 / 20 0 0 10
EHA 71 41 77 38 / 10 0 0 0
LBL 73 39 80 39 / 20 0 0 0
HYS 70 42 78 43 / 20 10 10 20
P28 69 44 80 48 / 50 10 0 0
&&
.DDC Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Ruthi
LONG TERM...Ruthi
AVIATION...Ruthi
FIRE WEATHER...Ruthi
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
357 PM EDT SUN MAR 13 2016
.DISCUSSION...
WHAT IS NOW THE PRIMARY VORTICITY MAXIMUM THAT EMERGED OUT OF THE
EARLY WEEK TX/MEXICO UPPER LEVEL LOW SYSTEM IS NOW LIFTING DUE
NORTHWARD OVER PORTIONS OF IL/IN THIS AFTERNOON. THIS ENERGY IS
EXPECTED TO TRACK DIRECTLY THROUGH WESTERN LOWER MICHIGAN THIS
EVENING. WITH TIME...THIS UPPER LEVEL LOW CENTER AND THE RESULTANT
CHANGE IN KINEMATICS/WIND DIRECTION WILL FORCE A CHANGE IN THE
ADVECTIONS AND EVENTUALLY SQUEEZE THE 850-700MB FGEN AXIS THAT HAD
BEEN RESPONSIBLE FOR THE WET DAY...TO THE NORTH OUT OF SOUTHEASTERN
MICHIGAN. THIS WILL STILL TAKE SOME TIME TO HAPPEN HOWEVER...AS THE
OVERALL EVENT IS A SLOW EVOLVING ONE. A SHARP NORTHERN CUTOFF TO THE
PRECIPITATION WILL EXIST ALONG THE NORTHERN PERIPHERY THE CENTER OF
THE PRECIPITATION AXIS TO BE OVER THE CENTRAL CWA AT 00Z...OVER THE
NORTHERN THUMB AND CENTRAL LAKE HURON AT 06Z...WITH THE SOUTHERN
EDGE OF THE BAND EXITING THE CWA AT/AROUND 10Z MONDAY MORNING. RH
PROGS...SATELLITE TRENDS...UPSTREAM CEILIOMETER OBS...SUPPORT SOME
COMPONENT OF MIDLEVEL DRY AIR OR A MIDLEVEL DRY SLOT OF SORTS TO
BEGIN LIFTING INTO SOUTHERN MICHIGAN AFTER 00Z THIS EVENING. THIS
WOULD END PRECIPITATION CHANCES FROM SOUTH TO NORTH. HOWEVER...HOW
MUCH MIDLEVEL DRY AIR INITIALLY IS UP FOR DEBATE. PREFER A MIDDLE OF
THE ROAD SOLUTION WHERE PRECIPITATION RATES WILL BE STRIPPED OUT WITH
A TRANSITION TO DRIZZLE FROM SOUTH TO NORTH WITH TIME...HOWEVER...
FOR THOSE THAT REMAIN WITHIN THE HEART OF THE FGEN AXIS RATES WILL
BE SLOW TO WANE. IN THE EARLIER UPDATE...DISCUSSED HOW TOTAL
PRECIPITATION RAINFALL ESTIMATE WAS PROBABLY OVERDOING AMOUNTS.
WHILE TRUE ON THE FRONT END OF THE ENVIRONMENT WHERE DRY AIR WAS
FIGHTING OF PRECIPITATION...IT APPEARS THAT RATES ARE CERTAINLY
DOING WELL WITH COLUMN SATURATION. MANY AREAS IN THE DETROIT METRO
HAVE ALREADY SEEN A FOOTPRINT OF .25 TO .40 OF AN INCH. GIVEN THE
TIME YET TO GO AND THE BULLISH RAP QPF FIELD...TOTAL QPF IN EXCESS OF
.50 INCH...TO .75 INCH WILL REMAIN POSSIBLE.
SOME VARIOUS SOLUTIONS...INCLUDING NAM AND HRRR ARE TRYING TO
PRESERVE SOME SPURIOUS AND ANOMALOUS QPF MAXIMUM ALONG THE LEADING
CVA OF AFOREMENTIONED SHORTWAVE. THIS MODELED CONVECTION HAS BEEN
FORECASTED TO LIFT DIRECTLY NORTH OVER CENTRAL LOWER MICHIGAN INTO
MBS...CONTAMINATING THE QPF FIELD. IT SEEMS THE CENTRAL INDIANA
CLUSTER WILL HAVE A DIFFICULT TIME SURVIVING WITH THE GENERAL LACK
OF STEEP MIDLEVEL LAPSE RATES. WITH THAT SAID...EXPECTING A
TRANSITION FROM LAMINAR STRATIFORM RAIN TO MORE RAIN SHOWERS AFTER
00Z THIS EVENING.
PER MODEL SOUNDINGS THE POTENTIAL FOR SOME WIDESPREAD FOG
DEVELOPMENT CONTINUES TO EXIST. WILL NEED TO SEE HOW THE STRENGTH OF
THE GRADIENT FLOW WILL EVOLVE OVERNIGHT WITH SOME DATA SETS
SUGGESTING UPWARDS OF 6 TO 7 KNOTS OF SUSTAINED WIND HOLDING ON.
MODELED CONDENSATION PRESSURE DEFICIT FIELD POINT TO THIS DIRECTION
BUT NOT ENOUGH CONSENSUS OR CONFIDENCE EXISTS TO HEIGHTEN ANY
MESSAGE. FEELING IS IT COULD BE AS LATE AS 10Z BEFORE FOG
DEVELOPS...AND POSSIBLY TAKE UNTIL VERY LATE MORNING TO LIFT.
A WEAKNESS OR BUCKLE IN THE UPPER LEVEL HEIGHT FIELD DIRECTLY OVER
SOUTHEASTERN MICHIGAN CONTINUES TO SUGGEST PERSISTENT CYCLONIC FLOW
AND TROUGHINESS OVER THE STATE ON MONDAY. THE WEAK SURFACE
REFLECTION SLIDING THROUGH THE CWA SUGGESTS LITTLE CHANGE IN THE
OVERALL AIRMASS. RH PROGS SHOW SOLID SATURATION HOLDING AT 700MB AND
THIS RAISES QUESTION AS TO THE POTENTIAL TO BREAK OUT OF THE CLOUDS.
TEMPERATURES WILL WARM ON THE SHOULDERS OF WARM AIR ADVECTION AND
THE LACK OF PRECIPITATION. IN ADDITION...THE LACK OF A MORE
FOCUSED SURFACE REFLECTION/SURFACE LOW WILL ALLOW MORE
SOUTHWESTERLY FLOW EFFECTS INTO THE SAGINAW VALLEY...SLIGHTLY LESS
OF A TEMPERATURE GRADIENT ACROSS THE CWA. HIGHS WILL RANGE IN THE
50S TO 60 DEGREES FAR SOUTH. THE TEMPERATURE RESPONSE WILL BE
DEPENDENT ON THE AMOUNT OF CLOUD/FOG IN THE MORNING. IT COULD TAKE
UNTIL LATE AFTERNOON FOR TEMPERATURES TO WARM APPRECIABLY.
THE MONDAY AFTERNOON PERIOD SEEMS IT WILL BE GOVERNED BY A COMPLEX
INTERACTION THAT WILL OCCUR BETWEEN THE UPPER LEVEL ENERGY NOW
LIFTING INTO LOWER MICHIGAN AND THE MORE VIGOROUS LOW AFFECTION
PORTIONS OF ARKANSAS. THE NORTHERN SPIRAL EDGE TO THE VIGOROUS
SHORTWAVE IS EXPECTED TO UNRAVEL AND BE CAUGHT WITHIN A TRAILING
DEFORMATION AXIS OF THIS PRECEDING WAVE. ESSENTIALLY SHORTWAVE
ENERGY WILL THEN ZIPPER ALONG THIS DEFORMATION AXIS BRINGING
INCREASING CHANCES FOR SHOWERS MONDAY AFTERNOON FOR THE FAR
SOUTHEASTERN CWA. BASED ON EARLIER DATA...SHADED DRY FOR MONDAY
NIGHT...BUT MAY HAVE BEEN AN OVERCORRECTION AS SOME LINGERING
SHOWERS COULD PERSIST BEYOND 00Z TUESDAY.
THE COMPLEXITIES CONTINUE INTO TUESDAY FOR THE NEXT SYSTEM AS THE
MODELS CONTINUE TO ADVERTISE A FAIRLY DYNAMIC SETUP. THE PROBLEM IS
THERE IS A MYRIAD OF PV INTERACTIONS YET TO OCCUR THAT WILL HAVE
A SAY IN THE FINAL OUTCOME. THE TREND FOR THE 13.12Z SUITE WAS TO
PUSH TIMING OF THE SHOWERS AND THUNDERSTORM ON THE THETA E RIDGE
INTO THE 06-12Z WEDNESDAY WINDOW...WHILE WAITING ON THE SURFACE
COLD FRONT UNTIL AFTER 12Z WEDNESDAY. LATEST SWODY3 HAS A MARGINAL
DESIGNATION FOR SEVERE WEATHER FOR THE SOUTHERN CWA CONDITIONAL ON
UPSTREAM...ORGANIZED THUNDERSTORM ACTIVITY PROPAGATING DOWNSTREAM
INTO SOUTHEASTERN MICHIGAN. IT REMAINS A FLUID SITUATION BASED ON
DEPENDENCE OF TIMING AND ABILITY TO BECOME WELL MIXED AT THE
SURFACE...BUT THE POTENTIAL APPEARS GOOD FOR ELEVATED THUNDERSTORM
ACTIVITY LATE TUESDAY NIGHT. STRONG GUSTY WINDS TO DEVELOP IN THE
WAKE OF THE COLD FRONT PASSAGE ON MONDAY. CONFIDENCE IS LOW ON HOW
THE FRONTAL PASSAGE WILL TRANSPIRE...BUT CONFIDENCE IS FAIRLY HIGH
THAT THERMODYNAMICS AND VERY DEEP MIXING WILL SUPPORT BREEZY TO
POSSIBLE WINDY CONDITIONS WEDNESDAY AFTERNOON.
TEMPERATURES WILL REMAIN ABOVE THE SEASONAL AVERAGE THROUGH
WEDNESDAY...WITH HIGH`S IN THE MID TO UPPER 50`S. A COOLING TREND
IS EXPECTED THURSDAY THROUGH THE WEEKEND.
&&
.MARINE...
FRESH EASTERLY FLOW WILL REMAIN IN PLACE FOR MUCH OF TONIGHT ACROSS
THE NORTHERN GREAT LAKES AHEAD OF A WARM FRONT THAT WILL LIFT INTO
THE REGION. WINDS WILL THEN WEAK DURING THE COURSE OF MONDAY HAS A
WEAK AND VERY BROAD SURFACE LOW PRESSURE CENTER DRIFT ACROSS
SOUTHERN MICHIGAN AND THE CENTRAL GREAT LAKES. WINDS WILL RESPOND
TEMPORARILY OUT OF THE NORTH MONDAY NIGHT IN RESPONSE TO THE LOW
EXITING THE AREA...BEFORE QUICKLY ORGANIZING EASTERLY AGAIN AHEAD OF
AN APPROACHING LOW PRESSURE SYSTEM. THIS NEXT LOW PRESSURE SYSTEM IS
FORECASTED TO BE MUCH MORE DYNAMIC. THERE IS UNCERTAINTY IN TIMING
YET...BUT THERE IS GOOD AGREEMENT THIS LOW PRESSURE SYSTEM WILL SEND
A STRONG COLD FRONT ACROSS THE REGION SOMETIME VERY LATE TUESDAY
NIGHT OR DURING THE EARLY PORTION OF WEDNESDAY. POSTFRONTAL WESTERLY
WINDS ON WEDNESDAY WILL LIKELY EXCEED 25 KNOTS OVER LAKE ERIE...LAKE
ST CLAIR AND THE SOUTHERN BASIN OF LAKE HURON.
&&
.AVIATION...ISSUED 146 PM EDT SUN MAR 13 2016
VARIABLE CONDITIONS ACROSS THE TERMINAL CORRIDOR AS AREA OF RAINFALL
CONTINUES TO PUSH NORTHWARD...ON THE DOORSTEP OF FNT AT PRESS TIME
AND DUE INTO MBS BY 21Z. RAIN SHOWERS OVER THE METRO TERMINALS ARE
RESULTING IN BORDERLINE MVFR/IFR VSBY AND A VFR CLOUD DECK WITH A
SCT-BKN IFR LAYER. WENT WITH A TEMPO FOR THE NEXT 3-4 HOURS TO COVER
THIS VARIABILITY. IFR CONDITIONS WILL BECOME MORE PREVALENT AFTER
23Z...SUPPORTED BY OBS OVER INDIANA AND OHIO. A PERIOD OF LIFR IS
LIKELY TO DEVELOP OVERNIGHT...WITH SOME UNCERTAINTY ON HOW LOW VSBY
WILL DROP GIVEN THAT THE GRADIENT WILL NOT DROP OFF TOO MUCH /SAVE
FOR AT MBS WHERE THE SURFACE LOW WILL TRACK DIRECTLY OVERHEAD/.
FOR DTW...PERSISTENT EAST-NORTHEAST FLOW CONTINUES THIS AFTERNOON
AND EVENING. VARIABLE CIGS/VSBY WILL TREND DOWNWARD TO IFR AFTER 23Z
THIS EVENING. A PERIOD OF VLIFR IS POSSIBLE AFTER 06Z TONIGHT...BUT
UNCERTAINTY WITH HOW LOW WIND SPEEDS WILL GET PRECLUDES DROPPING
VSBY BELOW 1/2 SM FOR THIS ISSUANCE. CONDITIONS WILL IMPROVE AFTER
SUNRISE MONDAY AS THE SURFACE LOW PULLS AWAY AND WINDS SHIFT TO
SOUTH-SOUTHWESTERLY.
//DTW THRESHOLD PROBABILITIES...
* HIGH FOR CEILINGS AOB 5KFT.
* MEDIUM FOR CEILINGS AOB 200 FEET AND/OR VSBYS AOB 1/2SM TONIGHT.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
DISCUSSION...CB/DE
MARINE.......CB
AVIATION.....DT
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
143 PM EDT SUN MAR 13 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 529 AM EDT SUN MAR 13 2016
WV IMAGERY AND RAP ANALYSIS INDICATED A MID/UPPER LEVEL RIDGE FROM
THE MID ATLANTIC TO NW ONTARIO AND A TROUGH INTO THE SRN PLAINS
RESULTING IN SRLY THROUGH THE MID MS VALLEY TO THE WRN LAKES. A WELL-
DEFINED SHRTWV OR CLOSED LOW WAS LOCATED OVER THE TX PANHANDLE WHILE
WEAKER UPSTREAM SHRTWVS OVER IA/IL SUPPORTED SHRA FROM SRN MN
THROUGH NE IA INTO NRN IL AND NRN INDIANA. AT THE SFC...A RIDGE FROM
NEAR JAMES BAY INTO THE NRN LAKES HAS MAINTAINED DRY LOW LEVEL ERLY
FLOW THROUGH UPPER MI. HOWEVER...IR LOOP SHOWED HIGH CLOUDS
SPREADING OVER MOST OF THE CWA.
TODAY...MODELS SUGGEST THAT THE PCPN ASOCIATED MOISTURE AXIS WITH
THE MORE FAVORABLE SRLY LOW LEVEL FLOW WILL REMAIN TO THE WEST OVER
MN WHILE THE AREA OF PCPN EHAD OF A SHRTWV LIFTING OUT OF THE MID MS
VALLEY WILL REMAIN TO THE S OF UPPER MI WITH ONLY A SLIGHT CHANCE OF
ANY PCPN INTO SRN CWA. EVEN WITH MOSTLY CLOUDY SKIES...TEMPS WILL
AGAIN REMAIN WELL ABOVE NORMAL WITH HIGHS FROM THE MID 40S N
CNTRL...EAST AND ALONG LAKE MICHIGAN TO THE MID 50S INLAND WEST.
TONIGHT...CONSISTENT WITH THE MODELS TRENDS...A SHRTWV LIFTING NNE
INTO LOWER MI IS EXPECTED TO KEEP THE BULK OF THE PCPN TO THE EAST
OF UPPER MI. ACCORDINGLY THE HIGHEST POPS REMAIN OVER THE SRN AND
ERN CWA.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 427 AM EDT SUN MAR 13 2016
...PATTERN TURNING COLDER WITH WINTRY PRECIPITATION POSSIBLE MID
TO LATE WEEK...
00Z UPPER AIR ANALYSIS SHOWS VIGOROUS SPLIT FLOW PATTERN WITH
SOUTHERN STREAM TIED INTO THE UNRAVELING UPPER TROUGH HEADING TOWARD
OHIO VALLEY/LOWER AND UPSTREAM UPPER TROUGH SOUTHERN PLAINS TO THE
SOUTHEAST UNITED STATES. PARTS OF UPPER GREAT LAKES MAY GET CLIPPED
BY THE DECAYING SYSTEM...BUT MOST RAIN SHOULD STAY TO THE EAST OF
UPR MICHIGAN.
ATTN THIS WEEK TURNS TO STRONG NORTHERN STREAM JET STREAM OVER 150
KTS PUSHING INTO WEST COAST.THIS MORNING. THIS JET WILL SLIDE ACROSS
THE ROCKIES AND DIG STRONG TROUGH ALOFT OVER MUCH OF THE NORTHERN
CONUS WEST OF THE MISSISSIPPI RIVER BY LATER TUE. JET WILL EXPAND
ACROSS OHIO VALLEY AND TOWARD THE NORTHEAST CONUS LATE THIS
WEEK...LEAVING WIDESPREAD TROUGHING FM THE CANADIAN ROCKIES OVER THE
NORTHERN PLAINS AND OVER MUCH OF THE GREAT LAKES. THE WARMTH SEEN
OVER THE REGION ON SAT WILL GIVE WAY TO MUCH COLDER PATTERN MID TO
LATE THIS WEEK...THOUGH MAY BE ABLE TO SNEAK IN WARMER DAY ON TUE
AHEAD OF THIS PATTERN CHANGE. ONCE ESTABLISHED THE COLDER PATTERN
MAY TAKE A WHILE TO DEPART. AT THE LEAST WILL SEE TEMPS AT OR BLO
NORMAL...AND IF THE TROUGH CAN EXPAND DEPTH INTO NORTHERN CANADA
WOULD HAVE CHANCE AT SEEING WELL BELOW NORMAL TEMPS EARLY TO MID OF
NEXT WEEK AS RECENT GFS RUNS HAVE SHOWN WITH H85 TEMPS DROPPNIG TO
NEAR -20C. ECMWF IS NOT AS COLD BUT STILL SHOWS -10C TO -12C. PRECIP
IN THIS PATTERN SHIFT COULD BE ACTIVE...WHICH WOULD MEAN A RETURN TO
CHANCES OF SNOW. DOES NOT APPEAR WE ARE DONE WITH WINTRY TYPE
WEATHER YET.
MAIN FOCUS FOR RAIN WILL BE EAST OF CWA ON MON. WILL HAVE TO WATCH
POSSIBLE DEVELOPING RAIN OVER MAINLY WEST CWA AS SHORTWAVE TRACKING
ACROSS MINNESOTA AND TAIL END OF JET STREAK OVER NORTHERN ONTARIO
MAY PROVIDE ENOUGH FORCING. THIS FORCING DIMINISHES ON MON NIGHT SO
DO NOT EXPECT MUCH IN WAY OF RAIN SHOWERS ATTM. LEAD LOW PRESSURE
SYSTEM WHICH IS COMING ASHORE TODAY WITH STRONG WINDS FOR PACIFIC NW
AND BRITISH COLUMBIA MOVES OUT OVER NORTHERN PLAINS ON TUESDAY WITH
SECONDARY LOW FARTHER SOUTHEAST ACROSS MIDDLE MISSISSIPPI RIVER
VALLEY. WARM AIR AND MOISTURE ADVECTION AHEAD OF BOTH THESE FEATURES
WILL SPREAD CLOUDS AND SOME SHOWERS OVER MUCH OF CWA TUE. SEEMS THAT
THERE IS SLOWER TREND IN BRINGING THE MOISTURE AND RAIN IN THOUGH
SO INCREASED HIGHS WITH EXPECTATION THAT THERE MAY BE SOME FILTERED
SUNSHINE FOR A WHILE.
BETTER CHANCE OF RAIN MOVES IN TUE NIGHT AS DOUBLE BARRELLED LOW
MOVES FM SOUTHERN MANITOBA TO WISCONSIN BY WED MORNING. DIFFLUENT
FLOW ALOFT/DEEP LAYER Q-VECTOR CONVERGENCE/LOW-LEVEL CONVERGENCE
AHEAD OF THE LOW/S BOOSTED BY 925-950MB WINDS 40+ KTS COMBINED WITH
PWATS OVER 0.75 INCHES /AT LEAST 250 PCT OF NORMAL/ LEAD TO GOOD
CHANCE OF MODERATE RAIN WITH EVEN PERHAPS A BRIEF PERIOD OF HEAVY
RAIN. NAM SEEMS MOST AGGRESSIVE WITH QPF SHOWING OVER 1 INCH AT SOME
LOCATIONS. GFS MORE IN THE 0.5-0.75 INCH RANGE. SREF MEMBERS SHOW
DECENT SPREAD BUT ARE MORE IN LINE WITH THE GFS INSTEAD OF THE
WETTER NAM. COLD AIR SLOW TO MOVE IN WITH H85 TEMPS AND 1000-850MB
THICKNESSES MARGINAL FOR MUCH SNOW MIXING IN UNTIL LATER WED MORNING
OR WED AFTN. WITH SFC LOW TRACKING TO THE SOUTH AND COLD AIR
ADVECTION FM NORTHERN ONTARIO...KEWEENAW HIGHER TERRAIN SEEMS TO BE
BEST IN LINE FOR SEEING ACCUMULATING SNOW...BUT MANY HIGHER TERRAIN
AREAS OF WEST AND NCNTRL CWA MAY SEE MIX OF RAIN/SNOW ON WED AS WELL.
SFC-H85 LOW OVER THE UPPER GREAT LAKES WEAKENS AS WED NIGHT INTO THU
AS STRONGER SHORTWAVE ENERGY MOVES TOWARD NORTHEAST CONUS. GRADUAL
COOLER AIR SHOULD SUPPORT MAINLY LIGHT SNOW SHOWERS IN THE LINGERING
MOIST/CYCLONIC FLOW SURROUNDING DECAYING LOW-LEVEL LOW. H85 TEMPS OF
-4C TO -6C ARE NOT COLD ENOUGH FOR ANY LAKE ENHANCED/LAKE EFFECT
SNOW...BUT UPSLOPE FLOW OVER WEST AND NORTH CENTRAL UPR MICHIGAN
COULD LEAD TO LIGHT SNOW ACCUMS. REST OF EXTENDED...MODELS ARE ALL
OVER THE PLACE WITH INDIVIDUAL FEATURES. ECMWF SHOWS SHORTWAVE
TROUGH LINGERING LATE THIS WEEK THEN RETROGRADING BACK TO WEST ONLY
TO BE SWEPT ALONG BY ANOTHER TROUGH CROSSING THE WESTERN CONUS. GFS
TAKES MAJORITY OF UPPER LOW ON TO THE EAST LATE THIS WEEK. GEM-NH
LINGERS THE TROUGH OVER THE UPPER GREAT LAKES ENTIRE TIME. OVERALL
LARGER SCALE MEAN TROUGHING WILL PERSIST SO EXPECT TEMPS AT OR BLO
NORMAL INTO NEXT WEEKEND. JUST NOT SURE ON ANY SYSTEMS WITHIN THIS
FLOW PATTERN. USED A MODEL CONSENSUS WHICH INDICATED LOW CHANCE POPS
INTO THE WEEKEND. PTYPE WILL BE SNOW OR A MIX OF RAIN/SNOW.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 142 PM EDT SUN MAR 13 2016
EXPECT OVERALL DIMINISHING TREND AS A SERIES OF SHORTWAVE TROUGHS
BRING AMPLE MOISTURE TO THE AREA. MOST UNCERTAIN WITH PRECIP
POTENTIAL AS ALL SITES WILL BE ON THE PERIPHERY OF BETTER
PRECIP...SO JUST INCLUDED VCSH.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 529 AM EDT SUN MAR 13 2016
STRONGEST WINDS FOR THIS FORECAST PERIOD ARE EXPECTED TUE NIGHT INTO
WED MORNING WHERE EAST TO NORTHEAST WINDS UP TO 30 KNOTS ARE
POSSIBLE. OTHERWISE...WINDS SHOULD REMAIN BELOW 25 KNOTS FOR THIS
FORECAST PERIOD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...TITUS
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
747 AM EDT SUN MAR 13 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 529 AM EDT SUN MAR 13 2016
WV IMAGERY AND RAP ANALYSIS INDICATED A MID/UPPER LEVEL RIDGE FROM
THE MID ATLANTIC TO NW ONTARIO AND A TROUGH INTO THE SRN PLAINS
RESULTING IN SRLY THROUGH THE MID MS VALLEY TO THE WRN LAKES. A WELL-
DEFINED SHRTWV OR CLOSED LOW WAS LOCATED OVER THE TX PANHANDLE WHILE
WEAKER UPSTREAM SHRTWVS OVER IA/IL SUPPORTED SHRA FROM SRN MN
THROUGH NE IA INTO NRN IL AND NRN INDIANA. AT THE SFC...A RIDGE FROM
NEAR JAMES BAY INTO THE NRN LAKES HAS MAINTAINED DRY LOW LEVEL ERLY
FLOW THROUGH UPPER MI. HOWEVER...IR LOOP SHOWED HIGH CLOUDS
SPREADING OVER MOST OF THE CWA.
TODAY...MODELS SUGGEST THAT THE PCPN ASOCIATED MOISTURE AXIS WITH
THE MORE FAVORABLE SRLY LOW LEVEL FLOW WILL REMAIN TO THE WEST OVER
MN WHILE THE AREA OF PCPN EHAD OF A SHRTWV LIFTING OUT OF THE MID MS
VALLEY WILL REMAIN TO THE S OF UPPER MI WITH ONLY A SLIGHT CHANCE OF
ANY PCPN INTO SRN CWA. EVEN WITH MOSTLY CLOUDY SKIES...TEMPS WILL
AGAIN REMAIN WELL ABOVE NORMAL WITH HIGHS FROM THE MID 40S N
CNTRL...EAST AND ALONG LAKE MICHIGAN TO THE MID 50S INLAND WEST.
TONIGHT...CONSISTENT WITH THE MODELS TRENDS...A SHRTWV LIFTING NNE
INTO LOWER MI IS EXPECTED TO KEEP THE BULK OF THE PCPN TO THE EAST
OF UPPER MI. ACCORDINGLY THE HIGHEST POPS REMAIN OVER THE SRN AND
ERN CWA.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 427 AM EDT SUN MAR 13 2016
...PATTERN TURNING COLDER WITH WINTRY PRECIPITATION POSSIBLE MID
TO LATE WEEK...
00Z UPPER AIR ANALYSIS SHOWS VIGOROUS SPLIT FLOW PATTERN WITH
SOUTHERN STREAM TIED INTO THE UNRAVELING UPPER TROUGH HEADING TOWARD
OHIO VALLEY/LOWER AND UPSTREAM UPPER TROUGH SOUTHERN PLAINS TO THE
SOUTHEAST UNITED STATES. PARTS OF UPPER GREAT LAKES MAY GET CLIPPED
BY THE DECAYING SYSTEM...BUT MOST RAIN SHOULD STAY TO THE EAST OF
UPR MICHIGAN.
ATTN THIS WEEK TURNS TO STRONG NORTHERN STREAM JET STREAM OVER 150
KTS PUSHING INTO WEST COAST.THIS MORNING. THIS JET WILL SLIDE ACROSS
THE ROCKIES AND DIG STRONG TROUGH ALOFT OVER MUCH OF THE NORTHERN
CONUS WEST OF THE MISSISSIPPI RIVER BY LATER TUE. JET WILL EXPAND
ACROSS OHIO VALLEY AND TOWARD THE NORTHEAST CONUS LATE THIS
WEEK...LEAVING WIDESPREAD TROUGHING FM THE CANADIAN ROCKIES OVER THE
NORTHERN PLAINS AND OVER MUCH OF THE GREAT LAKES. THE WARMTH SEEN
OVER THE REGION ON SAT WILL GIVE WAY TO MUCH COLDER PATTERN MID TO
LATE THIS WEEK...THOUGH MAY BE ABLE TO SNEAK IN WARMER DAY ON TUE
AHEAD OF THIS PATTERN CHANGE. ONCE ESTABLISHED THE COLDER PATTERN
MAY TAKE A WHILE TO DEPART. AT THE LEAST WILL SEE TEMPS AT OR BLO
NORMAL...AND IF THE TROUGH CAN EXPAND DEPTH INTO NORTHERN CANADA
WOULD HAVE CHANCE AT SEEING WELL BELOW NORMAL TEMPS EARLY TO MID OF
NEXT WEEK AS RECENT GFS RUNS HAVE SHOWN WITH H85 TEMPS DROPPNIG TO
NEAR -20C. ECMWF IS NOT AS COLD BUT STILL SHOWS -10C TO -12C. PRECIP
IN THIS PATTERN SHIFT COULD BE ACTIVE...WHICH WOULD MEAN A RETURN TO
CHANCES OF SNOW. DOES NOT APPEAR WE ARE DONE WITH WINTRY TYPE
WEATHER YET.
MAIN FOCUS FOR RAIN WILL BE EAST OF CWA ON MON. WILL HAVE TO WATCH
POSSIBLE DEVELOPING RAIN OVER MAINLY WEST CWA AS SHORTWAVE TRACKING
ACROSS MINNESOTA AND TAIL END OF JET STREAK OVER NORTHERN ONTARIO
MAY PROVIDE ENOUGH FORCING. THIS FORCING DIMINISHES ON MON NIGHT SO
DO NOT EXPECT MUCH IN WAY OF RAIN SHOWERS ATTM. LEAD LOW PRESSURE
SYSTEM WHICH IS COMING ASHORE TODAY WITH STRONG WINDS FOR PACIFIC NW
AND BRITISH COLUMBIA MOVES OUT OVER NORTHERN PLAINS ON TUESDAY WITH
SECONDARY LOW FARTHER SOUTHEAST ACROSS MIDDLE MISSISSIPPI RIVER
VALLEY. WARM AIR AND MOISTURE ADVECTION AHEAD OF BOTH THESE FEATURES
WILL SPREAD CLOUDS AND SOME SHOWERS OVER MUCH OF CWA TUE. SEEMS THAT
THERE IS SLOWER TREND IN BRINGING THE MOISTURE AND RAIN IN THOUGH
SO INCREASED HIGHS WITH EXPECTATION THAT THERE MAY BE SOME FILTERED
SUNSHINE FOR A WHILE.
BETTER CHANCE OF RAIN MOVES IN TUE NIGHT AS DOUBLE BARRELLED LOW
MOVES FM SOUTHERN MANITOBA TO WISCONSIN BY WED MORNING. DIFFLUENT
FLOW ALOFT/DEEP LAYER Q-VECTOR CONVERGENCE/LOW-LEVEL CONVERGENCE
AHEAD OF THE LOW/S BOOSTED BY 925-950MB WINDS 40+ KTS COMBINED WITH
PWATS OVER 0.75 INCHES /AT LEAST 250 PCT OF NORMAL/ LEAD TO GOOD
CHANCE OF MODERATE RAIN WITH EVEN PERHAPS A BRIEF PERIOD OF HEAVY
RAIN. NAM SEEMS MOST AGGRESSIVE WITH QPF SHOWING OVER 1 INCH AT SOME
LOCATIONS. GFS MORE IN THE 0.5-0.75 INCH RANGE. SREF MEMBERS SHOW
DECENT SPREAD BUT ARE MORE IN LINE WITH THE GFS INSTEAD OF THE
WETTER NAM. COLD AIR SLOW TO MOVE IN WITH H85 TEMPS AND 1000-850MB
THICKNESSES MARGINAL FOR MUCH SNOW MIXING IN UNTIL LATER WED MORNING
OR WED AFTN. WITH SFC LOW TRACKING TO THE SOUTH AND COLD AIR
ADVECTION FM NORTHERN ONTARIO...KEWEENAW HIGHER TERRAIN SEEMS TO BE
BEST IN LINE FOR SEEING ACCUMULATING SNOW...BUT MANY HIGHER TERRAIN
AREAS OF WEST AND NCNTRL CWA MAY SEE MIX OF RAIN/SNOW ON WED AS WELL.
SFC-H85 LOW OVER THE UPPER GREAT LAKES WEAKENS AS WED NIGHT INTO THU
AS STRONGER SHORTWAVE ENERGY MOVES TOWARD NORTHEAST CONUS. GRADUAL
COOLER AIR SHOULD SUPPORT MAINLY LIGHT SNOW SHOWERS IN THE LINGERING
MOIST/CYCLONIC FLOW SURROUNDING DECAYING LOW-LEVEL LOW. H85 TEMPS OF
-4C TO -6C ARE NOT COLD ENOUGH FOR ANY LAKE ENHANCED/LAKE EFFECT
SNOW...BUT UPSLOPE FLOW OVER WEST AND NORTH CENTRAL UPR MICHIGAN
COULD LEAD TO LIGHT SNOW ACCUMS. REST OF EXTENDED...MODELS ARE ALL
OVER THE PLACE WITH INDIVIDUAL FEATURES. ECMWF SHOWS SHORTWAVE
TROUGH LINGERING LATE THIS WEEK THEN RETROGRADING BACK TO WEST ONLY
TO BE SWEPT ALONG BY ANOTHER TROUGH CROSSING THE WESTERN CONUS. GFS
TAKES MAJORITY OF UPPER LOW ON TO THE EAST LATE THIS WEEK. GEM-NH
LINGERS THE TROUGH OVER THE UPPER GREAT LAKES ENTIRE TIME. OVERALL
LARGER SCALE MEAN TROUGHING WILL PERSIST SO EXPECT TEMPS AT OR BLO
NORMAL INTO NEXT WEEKEND. JUST NOT SURE ON ANY SYSTEMS WITHIN THIS
FLOW PATTERN. USED A MODEL CONSENSUS WHICH INDICATED LOW CHANCE POPS
INTO THE WEEKEND. PTYPE WILL BE SNOW OR A MIX OF RAIN/SNOW.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 746 AM EDT SUN MAR 13 2016
ALTHOUGH THERE WILL BE SOME THICKENING HIGH/MID CLOUDS THROUGH THIS
EVENING...THE LOW LEVELS WILL REMAIN SUFFICIENTLY DRY TO BRING ABOUT
PREDOMINANT VFR CIGS/VSBY UNTIL LATE TONIGHT. BEST CHANCE FOR
CONDITIONS TO AT LEAST APPORACH MVFR THIS EVENING WILL BE AT SAW BY
LATE THIS EVNG WITH SOME LLVL MSTR TRYING TO RETURN IN NEAR SFC SSE
FLOW OFF LK MI. BUT SINCE THE BULK OF THE PCPN IS LIKELY TO REMAIN TO
THE SE...WILL CONTINUE THE FCST VFR WX. HOWEVER...ENOUGH LOW LEVEL
MOISTURE WILL ARRIVE OVERNIGHT TO DROP CIGS TO IFR AT KSAW. MVFR CIGS
ARE EXPECTED AT KIWD AND KCMX WHERE A MORE DOWNSLOPE SSE FLOW
PREVAILS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 529 AM EDT SUN MAR 13 2016
STRONGEST WINDS FOR THIS FORECAST PERIOD ARE EXPECTED TUE NIGHT INTO
WED MORNING WHERE EAST TO NORTHEAST WINDS UP TO 30 KNOTS ARE
POSSIBLE. OTHERWISE...WINDS SHOULD REMAIN BELOW 25 KNOTS FOR THIS
FORECAST PERIOD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
532 AM EDT SUN MAR 13 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 529 AM EDT SUN MAR 13 2016
WV IMAGERY AND RAP ANALYSIS INDICATED A MID/UPPER LEVEL RIDGE FROM
THE MID ATLANTIC TO NW ONTARIO AND A TROUGH INTO THE SRN PLAINS
RESULTING IN SRLY THROUGH THE MID MS VALLEY TO THE WRN LAKES. A WELL-
DEFINED SHRTWV OR CLOSED LOW WAS LOCATED OVER THE TX PANHANDLE WHILE
WEAKER UPSTREAM SHRTWVS OVER IA/IL SUPPORTED SHRA FROM SRN MN
THROUGH NE IA INTO NRN IL AND NRN INDIANA. AT THE SFC...A RIDGE FROM
NEAR JAMES BAY INTO THE NRN LAKES HAS MAINTAINED DRY LOW LEVEL ERLY
FLOW THROUGH UPPER MI. HOWEVER...IR LOOP SHOWED HIGH CLOUDS
SPREADING OVER MOST OF THE CWA.
TODAY...MODELS SUGGEST THAT THE PCPN ASOCIATED MOISTURE AXIS WITH
THE MORE FAVORABLE SRLY LOW LEVEL FLOW WILL REMAIN TO THE WEST OVER
MN WHILE THE AREA OF PCPN EHAD OF A SHRTWV LIFTING OUT OF THE MID MS
VALLEY WILL REMAIN TO THE S OF UPPER MI WITH ONLY A SLIGHT CHANCE OF
ANY PCPN INTO SRN CWA. EVEN WITH MOSTLY CLOUDY SKIES...TEMPS WILL
AGAIN REMAIN WELL ABOVE NORMAL WITH HIGHS FROM THE MID 40S N
CNTRL...EAST AND ALONG LAKE MICHIGAN TO THE MID 50S INLAND WEST.
TONIGHT...CONSISTENT WITH THE MODELS TRENDS...A SHRTWV LIFTING NNE
INTO LOWER MI IS EXPECTED TO KEEP THE BULK OF THE PCPN TO THE EAST
OF UPPER MI. ACCORDINGLY THE HIGHEST POPS REMAIN OVER THE SRN AND
ERN CWA.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 427 AM EDT SUN MAR 13 2016
...PATTERN TURNING COLDER WITH WINTRY PRECIPITATION POSSIBLE MID
TO LATE WEEK...
00Z UPPER AIR ANALYSIS SHOWS VIGOROUS SPLIT FLOW PATTERN WITH
SOUTHERN STREAM TIED INTO THE UNRAVELING UPPER TROUGH HEADING TOWARD
OHIO VALLEY/LOWER AND UPSTREAM UPPER TROUGH SOUTHERN PLAINS TO THE
SOUTHEAST UNITED STATES. PARTS OF UPPER GREAT LAKES MAY GET CLIPPED
BY THE DECAYING SYSTEM...BUT MOST RAIN SHOULD STAY TO THE EAST OF
UPR MICHIGAN.
ATTN THIS WEEK TURNS TO STRONG NORTHERN STREAM JET STREAM OVER 150
KTS PUSHING INTO WEST COAST.THIS MORNING. THIS JET WILL SLIDE ACROSS
THE ROCKIES AND DIG STRONG TROUGH ALOFT OVER MUCH OF THE NORTHERN
CONUS WEST OF THE MISSISSIPPI RIVER BY LATER TUE. JET WILL EXPAND
ACROSS OHIO VALLEY AND TOWARD THE NORTHEAST CONUS LATE THIS
WEEK...LEAVING WIDESPREAD TROUGHING FM THE CANADIAN ROCKIES OVER THE
NORTHERN PLAINS AND OVER MUCH OF THE GREAT LAKES. THE WARMTH SEEN
OVER THE REGION ON SAT WILL GIVE WAY TO MUCH COLDER PATTERN MID TO
LATE THIS WEEK...THOUGH MAY BE ABLE TO SNEAK IN WARMER DAY ON TUE
AHEAD OF THIS PATTERN CHANGE. ONCE ESTABLISHED THE COLDER PATTERN
MAY TAKE A WHILE TO DEPART. AT THE LEAST WILL SEE TEMPS AT OR BLO
NORMAL...AND IF THE TROUGH CAN EXPAND DEPTH INTO NORTHERN CANADA
WOULD HAVE CHANCE AT SEEING WELL BELOW NORMAL TEMPS EARLY TO MID OF
NEXT WEEK AS RECENT GFS RUNS HAVE SHOWN WITH H85 TEMPS DROPPNIG TO
NEAR -20C. ECMWF IS NOT AS COLD BUT STILL SHOWS -10C TO -12C. PRECIP
IN THIS PATTERN SHIFT COULD BE ACTIVE...WHICH WOULD MEAN A RETURN TO
CHANCES OF SNOW. DOES NOT APPEAR WE ARE DONE WITH WINTRY TYPE
WEATHER YET.
MAIN FOCUS FOR RAIN WILL BE EAST OF CWA ON MON. WILL HAVE TO WATCH
POSSIBLE DEVELOPING RAIN OVER MAINLY WEST CWA AS SHORTWAVE TRACKING
ACROSS MINNESOTA AND TAIL END OF JET STREAK OVER NORTHERN ONTARIO
MAY PROVIDE ENOUGH FORCING. THIS FORCING DIMINISHES ON MON NIGHT SO
DO NOT EXPECT MUCH IN WAY OF RAIN SHOWERS ATTM. LEAD LOW PRESSURE
SYSTEM WHICH IS COMING ASHORE TODAY WITH STRONG WINDS FOR PACIFIC NW
AND BRITISH COLUMBIA MOVES OUT OVER NORTHERN PLAINS ON TUESDAY WITH
SECONDARY LOW FARTHER SOUTHEAST ACROSS MIDDLE MISSISSIPPI RIVER
VALLEY. WARM AIR AND MOISTURE ADVECTION AHEAD OF BOTH THESE FEATURES
WILL SPREAD CLOUDS AND SOME SHOWERS OVER MUCH OF CWA TUE. SEEMS THAT
THERE IS SLOWER TREND IN BRINGING THE MOISTURE AND RAIN IN THOUGH
SO INCREASED HIGHS WITH EXPECTATION THAT THERE MAY BE SOME FILTERED
SUNSHINE FOR A WHILE.
BETTER CHANCE OF RAIN MOVES IN TUE NIGHT AS DOUBLE BARRELLED LOW
MOVES FM SOUTHERN MANITOBA TO WISCONSIN BY WED MORNING. DIFFLUENT
FLOW ALOFT/DEEP LAYER Q-VECTOR CONVERGENCE/LOW-LEVEL CONVERGENCE
AHEAD OF THE LOW/S BOOSTED BY 925-950MB WINDS 40+ KTS COMBINED WITH
PWATS OVER 0.75 INCHES /AT LEAST 250 PCT OF NORMAL/ LEAD TO GOOD
CHANCE OF MODERATE RAIN WITH EVEN PERHAPS A BRIEF PERIOD OF HEAVY
RAIN. NAM SEEMS MOST AGGRESSIVE WITH QPF SHOWING OVER 1 INCH AT SOME
LOCATIONS. GFS MORE IN THE 0.5-0.75 INCH RANGE. SREF MEMBERS SHOW
DECENT SPREAD BUT ARE MORE IN LINE WITH THE GFS INSTEAD OF THE
WETTER NAM. COLD AIR SLOW TO MOVE IN WITH H85 TEMPS AND 1000-850MB
THICKNESSES MARGINAL FOR MUCH SNOW MIXING IN UNTIL LATER WED MORNING
OR WED AFTN. WITH SFC LOW TRACKING TO THE SOUTH AND COLD AIR
ADVECTION FM NORTHERN ONTARIO...KEWEENAW HIGHER TERRAIN SEEMS TO BE
BEST IN LINE FOR SEEING ACCUMULATING SNOW...BUT MANY HIGHER TERRAIN
AREAS OF WEST AND NCNTRL CWA MAY SEE MIX OF RAIN/SNOW ON WED AS WELL.
SFC-H85 LOW OVER THE UPPER GREAT LAKES WEAKENS AS WED NIGHT INTO THU
AS STRONGER SHORTWAVE ENERGY MOVES TOWARD NORTHEAST CONUS. GRADUAL
COOLER AIR SHOULD SUPPORT MAINLY LIGHT SNOW SHOWERS IN THE LINGERING
MOIST/CYCLONIC FLOW SURROUNDING DECAYING LOW-LEVEL LOW. H85 TEMPS OF
-4C TO -6C ARE NOT COLD ENOUGH FOR ANY LAKE ENHANCED/LAKE EFFECT
SNOW...BUT UPSLOPE FLOW OVER WEST AND NORTH CENTRAL UPR MICHIGAN
COULD LEAD TO LIGHT SNOW ACCUMS. REST OF EXTENDED...MODELS ARE ALL
OVER THE PLACE WITH INDIVIDUAL FEATURES. ECMWF SHOWS SHORTWAVE
TROUGH LINGERING LATE THIS WEEK THEN RETROGRADING BACK TO WEST ONLY
TO BE SWEPT ALONG BY ANOTHER TROUGH CROSSING THE WESTERN CONUS. GFS
TAKES MAJORITY OF UPPER LOW ON TO THE EAST LATE THIS WEEK. GEM-NH
LINGERS THE TROUGH OVER THE UPPER GREAT LAKES ENTIRE TIME. OVERALL
LARGER SCALE MEAN TROUGHING WILL PERSIST SO EXPECT TEMPS AT OR BLO
NORMAL INTO NEXT WEEKEND. JUST NOT SURE ON ANY SYSTEMS WITHIN THIS
FLOW PATTERN. USED A MODEL CONSENSUS WHICH INDICATED LOW CHANCE POPS
INTO THE WEEKEND. PTYPE WILL BE SNOW OR A MIX OF RAIN/SNOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 118 AM EST SUN MAR 13 2016
ALTHOUGH THERE WL BE SOME THICKENING HI/MID CLDS THRU THE FCST
PERIOD...THE LLVLS WL REMAIN SUFFICIENTLY DRY TO BRING ABOUT
PREDOMINANT VFR CIGS/VSBY. BEST CHC FOR CONDITIONS TO AT LEAST APRCH
MVFR WL BE AT SAW BY LATE THIS EVNG WITH SOME LLVL MSTR TRYING TO
RETURN IN NEAR SFC SSE FLOW OFF LK MI. BUT SINCE THE BULK OF THE
PCPN IS LIKELY TO REMAIN TO THE SE...WL CONTINUE THE FCST VFR WX.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 529 AM EDT SUN MAR 13 2016
STRONGEST WINDS FOR THIS FORECAST PERIOD ARE EXPECTED TUE NIGHT INTO
WED MORNING WHERE EAST TO NORTHEAST WINDS UP TO 30 KNOTS ARE
POSSIBLE. OTHERWISE...WINDS SHOULD REMAIN BELOW 25 KNOTS FOR THIS
FORECAST PERIOD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...KC
MARINE...JLB
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1047 PM CDT MON MAR 14 2016
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 320 PM CDT MON MAR 14 2016
TONIGHT AND TUESDAY...SFC ANALYSIS THIS AFTN DEPICTS A WAVY
STNRY FRONT /OR EVEN SIMPLY A SFC TROF/ ORIENTED NW-SE FROM NWRN ND
THRU CENTRAL IL...ASSOCIATED WITH A DEVELOPING LOW PRES CENTER OVER
THE NRN ROCKIES. ALOFT...AN INCOMING LONGWAVE H5 TROF MOVING ACROSS
THE NRN ROCKIES INTO THE NRN PLAINS WILL SHIFT EWD BUT ALSO HAVE A
CUTOFF LOW DEVELOP WITHIN THE TROF AXIS OVER SRN ALBERTA AND SRN
SASKATCHEWAN PROVINCES LATER THIS EVENING INTO EARLY MRNG TUE. THIS
UPR LOW IS EXPECTED TO EXPAND SEWD INTO THE NRN MISS RIVER VALLEY
DURG THE DAY ON TUE...MAKING FOR A LARGE AREA OF MID-TO-UPR LVL LIFT
WHICH WILL COINCIDE WITH PLENTY OF PACIFIC MOISTURE BEING BROUGHT
INTO THIS REGION BY THE TROF. AT THE SFC...A SECONDARY LOW PRES
CENTER DEVELOPING OVER CO/KS TONIGHT WILL BE PICKED UP BY THE TROF
AXIS AND PUSHED THROUGH THE MID-MISS RIVER VALLEY DURING THE DAY
TMRW. WITH A CDFNT STRETCHING BETWEEN BOTH SFC LOWS...ALONG WITH THE
DEEP MOISTURE AND THE EXPANDING LOW ALOFT...INGREDIENTS ARE IN PLACE
FOR A DECENT RAINFALL EVENT OVERNIGHT TONIGHT THROUGH MUCH OF
TUESDAY. PWATS APPROACH 1 INCH WITH THIS SYSTEM...MAINLY DURING THE
EARLY MORNING HOURS THROUGH THE FIRST HALF OF TOMORROW...THOUGH MUCH
OF THE QPF WILL LIKELY BE REALIZED DURING THE DAYLIGHT HOURS ON TUE.
MUCH OF THE AREA WILL RECEIVE 0.5 TO 1.0 INCHES OF RAIN...THOUGH
POCKETS OF HEIGHTENED INSTABILITY COULD CAUSE BRIEF HEAVY DOWNPOURS
AT TIMES WHICH COULD PUSH REALIZED QPF TO NEAR 1.5 INCHES. GIVEN THE
WARMER TEMPERATURES RECENTLY WHICH HAVE ELIMINATED FROST
DEPTHS...GROUND ABSORPTION SHOULD BE EFFECTIVE IN MITIGATING ANY
WIDER SCALE RUNOFF...AND HENCE FLOODING...ISSUES. HOWEVER...GIVEN
THE RAPID MOTION OF THE UPR LVL LOW AND ITS DEEPENING OVER THE
AREA...LOW AND MIDLVL HELICITIES WILL BE HEIGHTENED ALONG WITH THE
AFOREMENTIONED POCKETS OF HIGHER INSTABILITY PARAMETERS.
THEREFORE...ISOLD TSTMS ARE CERTAINLY POSSIBLE AND THIS ALIGNS WITH
THE GENERAL THUNDER OUTLINE IN THE SPC OUTLOOKS COVERING TONIGHT AND
TOMORROW. AS FOR TEMPERATURES...WITH THE CDFNT SLOW TO PUSH ACRS THE
AREA TMRW... THE MILD AIR THAT HAS BEEN RESIDENT OVER THE AREA WILL
REMAIN FOR ONE MORE DAY...ALONG WITH THE HIGHER DEWPOINTS. THIS WILL
SPELL LOWS TONIGHT IN THE UPR 40S TO LWR 50S WHILE HIGHS TMRW REACH
THE LWR-MID 50S. IF ANY SUNSHINE IS ABLE TO REALIZED
TOMORROW...WHICH IS NOT LIKELY...HIGHS COULD CLIMB TO NEAR 60 OVER
ERN MN INTO WRN MN.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 320 PM CDT MON MAR 14 2016
THE LONGER TERM CONCERN IS OVERALL COOLING TREND THROUGH THE
PERIOD ALONG WITH THE THREAT OF ACCUMULATING SNOW WEDNESDAY NIGHT
INTO THURSDAY.
INITIALLY THE OCCLUDED SYSTEM WILL BE POSITIONED ALONG THE MN/WI
BORDER THROUGH 00Z WED. THIS WILL CONTINUE THE THREAT OF RAIN AND
PERHAPS AN ISOLATED THUNDER THREAT THROUGH ABOUT 03Z WED INTO WEST
CENTRAL WI. AS THE UPPER TROUGH LIFTS OUT...THE UPPER CIRCULATION
CUTS OFF OVER THE GREAT LAKES. BOTH THE GFS AND ECMWF HANDLE THE
UPPER LEVEL CIRCULATION SIMILARLY THROUGH THURSDAY.
OVERALL...TEMPERATURES WILL COOL WITH SOME THREAT OF RAIN/SNOW MIX
OR PLAIN SNOW DEVELOPING AS THE TROUGH AXIS ROTATES SOUTH OVER THE
AREA. THE BEST CHANCE OF ACCUMULATING SNOW WOULD BE FOUND OVER THE
NORTHEAST CWA WEDNESDAY NIGHT INTO THURSDAY MORNING. AN INCH OR TWO
ACCUMULATION IS POSSIBLE...MAINLY NORTH OF I94 CORRIDOR IN CENTRAL MN
AND ALONG AND NORTH OF HIGHWAY 8 IN WEST CENTRAL WISCONSIN.
THE GENERAL NEAR OR SLIGHTLY BELOW NORMAL TEMPERATURE TREND WILL
CONTINUE THROUGH THE WEEKEND. THE PRECIPITATION THREAT SHOULD COME
TO AN END BY SATURDAY NIGHT AS THE EASTERN CONUS TROUGH EXITS TO THE
EAST. THIS WILL ALLOW FOR A MORE PACIFIC TYPE FLOW/ZONAL FLOW TO SET
UP WHICH IS EXPECTED TO INITIATE A WARMING TREND AGAIN NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1047 PM CDT MON MAR 14 2016
SEVERAL CONCERNS WITH THE OVERNIGHT FORECAST. FIRST...POCKETS OF
VFR CEILINGS HAVE DEVELOPED FROM KMSP ON WEST AND SOUTH THIS
EVENING. THERE ARE INDICATIONS USING THE 0.5KM CONDENSATION
PRESSURE DEFICITS FROM THE NAM AND RAP THAT A LARGE AREA OF VFR
CEILINGS COULD DEVELOP ACROSS CENTRAL AND SOUTHERN MN BY 09Z AND
PERSIST THROUGH 12Z. THIS DOES NOT SHOW UP IN THE MDL LAMP
PROBABILITIES WHICH KEEPS THE SITES MVFR OR LESS. SIDED MORE WITH
THE MDL LAMP PROBABILITIES FOR THE 06Z TAFS MAINLY DUE TO THE VERY
MOIST LOW LEVEL CONDITIONS WITH ANOMALOUSLY HIGH TEMPERATURES AND
DEW POINTS IN THE 50S AS WE APPROACH MIDNIGHT IN THE MIDDLE OF
MARCH. THEREFORE...DELAYED THE DROP TO IFR BY A FEW HOURS BUT
STILL HAVE HIGH CONFIDENCE IT WILL DEVELOP LATER IN THE NIGHT.
SHOWERS ARE SPREADING INTO WESTERN MN ON SCHEDULE AND THESE WILL
EXPAND DURING THE OVERNIGHT AND ON TUESDAY. THERE REMAINS A CHANCE
FOR SOME THUNDERSTORMS AS WELL OVERNIGHT. SEVERAL SHORT TERM
SOLUTIONS POINT TO THE TWIN CITIES IN THE 08Z-12Z TIME FRAME AND
FROM 10Z-14Z FOR KRNH AND KEAU. VCTS WAS INSERTED. SOUTHEAST WINDS
OVERNIGHT AND EARLY TUESDAY AT 10 KNOTS OR LESS WILL BECOME NW
TUESDAY AFTERNOON AND EVENING WITH SPEEDS INCREASING TO 15-20
KNOTS WITH GUSTS 25-30 KNOTS BY LATE TUESDAY NIGHT.
KMSP...ALLOWED FOR A LITTLE FLUCTUATION IN THE CEILING ABOVE AND
BELOW 030 AT THE START OF THE TAF WITH A DOWNWARD TREND TO IFR BY
12Z. ALSO INCLUDED VCTS IN THE 08Z-12Z TIME FRAME.
/OUTLOOK FOR KMSP/
WED...MVFR WITH CHC OF IFR CIGS/-RA. WIND W 15-20G30KTS.
THU...MVFR WITH CHC OF IFR CIGS/-RA/-SN. WIND N 10 KTS.
FRI...VFR. WIND NNE 6KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
&&
$$
SHORT TERM...JPC
LONG TERM...DWE
AVIATION...RAH
AREA FORECAST DISCUSSION
NWS JACKSON MS
1016 PM CDT MON MAR 14 2016
.UPDATE...
THE FORECAST IS GENERALLY ON TRACK FOR TONIGHT WITH SOME MINOR
ADJUSTMENTS TO INCREASE CLOUD COVER AFTER MIDNIGHT...ESPECIALLY FOR
THE AREA SOUTH OF I-20. LATEST IR IMAGERY REVEALS A DEVELOPING LOW
STRATUS DECK NEAR THE LA COAST PUSHING INLAND AS RETURN FLOW
INCREASES. BASED ON THESE TRENDS AND PER HRRR GUIDANCE HAVE
INDICATED A GREATER INCREASE IN CLOUD COVER. AS PREVIOUSLY
DISCUSSED...THERE IS SOME CONCERN FOR FOG OVER THE PINE BELT REGION
AS WELL.
FOR TOMORROW...MOST RECENT MOS GUIDANCE IS SHOWING STRONGER WIND
GUSTS IN THE DELTA REGION AND HAVE ADDED A MENTION OF THIS IN THE
HWO/GRAPHIC WITH EXPECTATION FOR WIND GUSTS TO EXCEED 30 MPH. THE
CURRENT FORECAST KEEPS WINDS BELOW WIND ADVISORY CRITERIA. /EC/
&&
.AVIATION...THE PRIMARY CONCERN WILL BE DEVELOPING IFR/LIFR CATEGORY
STRATUS AFTER 06Z AND LASTING UNTIL ROUGHLY 15Z IN THE MORNING. MOSTLY
LIKELY IMPACTS ARE AT HBG WHERE SOME FOG POTENTIAL EXISTS AS
WELL...AND LESS LIKELY AS YOU GO NORTH. EXPECT THE STRATUS TO MIX OUT
LEADING TO VFR CATEGORIES WITH GUSTY SOUTHWEST WINDS MAINLY AFFECTING
GLH/GWO DURING THE LATE MORNING AFTERNOON. /EC/
&&
.PREV DISCUSSION... /ISSUED 416 PM CDT MON MAR 14 2016/
SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT...THE SKIES HAVE
CLEARED THIS AFTERNOON AND MOST SITES WERE REPORTING UPPER 70S TO
LOWER 80S AT 3PM. ALTHOUGH TEMPERATURES WILL BE COOLER TONIGHT THAN
THEY HAVE THE LAST SEVERAL NIGHTS...WARMER THAN NORMAL TEMPERATURES
WILL CONTINUE. TUESDAY MORNING LOWS WILL RANGE FROM THE MID 50S EAST
TO THE LOWER 60S WEST. NORMAL MORNING LOWS RUN IN THE MID TO UPPER
50S. SPLIT FLOW REGIME WILL CONTINUE THROUGH THE END OF THE WEEK WITH
THE SOUTHERN BRANCH REMAINING ALONG THE GULF COAST. A NORTHERN STREAM
SHORTWAVE WILL DROP OVER THE CENTRAL PLAINS LATE TONIGHT AND SWING
EAST OVER THE MID MISSISSIPPI VALLEY BY TUESDAY EVENING. THIS
SHORTWAVE WILL SUPPORT A SURFACE LOW THAT WILL DROP A WEAK COLD FRONT
INTO OUR NORTHWEST MOST ZONES TUESDAY EVENING. THE TIGHTENING
PRESSURE GRADIENT TONIGHT FROM THE DEEPENING SURFACE LOW IS EXPECTED
TO HELP LEAD TO THE DEVELOPMENT OF STRATUS OVER THE SOUTHERN PORTIONS
OF OUR AREA BY MORNING. PATCHY DENSE FOG MAY DEVELOP OF THE SOUTHEAST
WHERE THE WINDS WILL BE LIGHTEST BUT A LOW LEVEL LAYER OF STRATUS
WILL BE MORE LIKELY OVER THE SOUTHWEST. THE NAM TRIES TO GENERATE
SOME VERY LIGHT PCPN WITH THIS STRATUS LAYER BUT MODEL CONSENSUS IS
DRY. THE STRATUS SHOULD DISSIPATE BY MID MORNING AND BREEZY SOUTHWEST
WINDS ARE EXPECTED TO DEVELOP. THIS WILL HELP AFTERNOON TEMPERATURES
SURGE BACK WELL ABOVE NORMAL IN THE MID TO UPPER 80S AT MOST
LOCATIONS. THE COLD FRONT LOOKS TO DROP INTO OUR CWA AS A DRY FRONT.
AS THE FRONT LOSES ITS SUPPORT TUESDAY NIGHT IT WILL STALL CLOSE TO
THE GULF COAST AND A WEAK SURFACE HIGH WILL BECOME CENTERED OVER OUR
CWA WEDNESDAY MORNING. MODELS REMAIN IN GOOD AGREEMENT TO THIS POINT
BUT DIFFER GOING INTO THE SECOND HALF OF THIS WEEK. THE SURFACE HIGH
IS EXPECTED TO SHIFT EAST WEDNESDAY AFTERNOON AS A SUBTLE SOUTHERN
STREAM DISTURBANCE MOVES EAST FROM THE SOUTHERN PLAINS. THIS
DISTURBANCE LOOKS TO COMBINE WITH DAYTIME HEATING AND THE STALLED
FRONT ACROSS THE GULF COAST TO GENERATE SOME CONVECTION THAT MAY
SPREAD INTO OUR SOUTHERN ZONES LATE AFTERNOON INTO WEDNESDAY EVENING.
MODEL CONSENSUS SUGGESTS THAN THE STALLED FRONT WILL BEGIN DRIFTING
NORTH AS A WEAK WARM FRONT WEDNESDAY NIGHT. THIS WILL RESULT IN RAIN
CHANCES CONTINUING THROUGH THE NIGHT. RAINFALL AMOUNTS THROUGH
WEDNESDAY NIGHT ARE EXPECTED TO BE LESS THAN A QUARTER OF AN INCH AND
MAINLY SOUTH OF INTERSTATE 20. /22/
LONG TERM...THURSDAY THROUGH SUNDAY...MODELS CONTINUE TO STRUGGLE
FOR AN OVERALL AGREEABLE SOLUTION DURING THE LONG TERM PORTION OF THE
FORECAST. WHILE THERE HAVE BEEN SOME SUBTLE INCONSISTENCIES IN THE
ECMWF...WHEN COMPARED TO THE GFS...IT HAS OVERALL BEEN A BIT MORE
CONSISTENT ON A RUN TO RUN BASIS. THEREFORE...FOR THE EVOLUTION OF
THE FORECAST FROM MID-WEEK THROUGH THE UPCOMING WEEKEND...IT`LL LEAN
CLOSER TO THE ECMWF.
A LITTLE BETTER MOISTURE WILL EXIST ALONG AND SOUTH OF THE STALLED
COLD FRONT. THIS...COMBINED WITH DIURNAL HEATING...AND INCREASING
FLOW ALOFT...COULD YIELD SOME SHOWERS AND STORMS...PRIMARILY SOUTH OF
THE INTERSTATE 20 CORRIDOR THURSDAY AFTERNOON AND EVENING. WHILE I`M
NOT GOING TO RULE OUT A STORM OR TWO BECOMING SEVERE...DUE TO THE
LOW CONFIDENCE IN THE OVERALL LONG TERM PORTION OF THE FORECAST...
I`LL NOT MENTION ANY POTENTIAL FOR SUCH STORMS IN THE HWO.
FRIDAY THROUGH SUNDAY...A ANOTHER UPPER LEVEL TROUGH TROUGH WILL
SWING EAST OUT OF THE THE NATION`S MID-SECTION AND INTO AND THROUGH
THE DEEP SOUTH. THIS WILL CAUSE A SURFACE LOW TO DEVELOP AND RACE
EAST NORTHEAST ALONG THE CENTRAL GULF COAST LATE FRIDAY THROUGH
SATURDAY. AS THIS HAPPENS...DECENT CHANCES FOR SHOWERS...AND A FEW
THUNDERSTORMS WILL AGAIN EXIST ACROSS THE FORECAST AREA THROUGH AT
LEAST SATURDAY NIGHT. AS THE LOW DEPARTS EARLY SUNDAY MORNING...
RAIN WILL FOLLOW SUIT. SKIES WILL CLEAR SUNDAY MORNING...WITH
COOLER AND NOTICEABLY DRIER CONDITIONS EXPECTED SUNDAY AFTERNOON AND
NIGHT. /19/22/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 57 87 56 80 / 0 2 6 16
MERIDIAN 53 84 56 78 / 0 2 8 14
VICKSBURG 58 87 55 79 / 0 2 5 16
HATTIESBURG 57 87 60 80 / 0 2 6 19
NATCHEZ 61 85 59 79 / 0 2 5 21
GREENVILLE 60 86 53 76 / 0 2 10 12
GREENWOOD 58 86 52 77 / 0 2 10 12
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1221 PM CDT SUN MAR 13 2016
.UPDATE...
ISSUED AT 1220 PM CDT SUN MAR 13 2016
VSBYS SLOWED IMPROVED THIS MORNING BUT CLOUDS REMAIN IN PLACE.
ISOLD TO SCT -SHRA DEVELOPED IN THE AREA FROM AROUND HEBRON AND
BEATRICE TOWARD FREMONT...BUT AS OF NOON COVERAGE HAD DECREASED.
RECENT EXPERIMENTAL HRRR MODEL RUNS CONTINUE TO SHOW POTENTIAL
FOR SHOWERS OVER ABOUT THE SERN 2/3 OF THE FCST AREA...WITH
CHANCES LOWER GENERALLY WEST OF A LINE FROM COLUMBUS TO WAYNE.
FCST SOUNDINGS DO NOT SHOW AS MUCH INSTABILITY THIS AFTN...SO
BACKED OFF ON MENTION OF ISOLD THUNDER UNTIL LATE AFTN. TEMPS
SHOULD TOP OUT MAINLY IN THE LOWER OR MID 60S.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 315 AM CDT SUN MAR 13 2016
AN INTENSE MID TO UPPER-LEVEL LOW WILL TRACK ACROSS THE SRN PLAINS
TODAY WITH A DOWNSTREAM SHORT-WAVE TROUGH WEAKENING CONSIDERABLY
WHILE EJECTING INTO THE GREAT LAKES. A SEPARATE POLAR-BRANCH AIR
STREAM WILL PERSIST FROM THE WEST COAST THROUGH N-CNTRL CONUS WITH
WEAK VORTICITY LOBES PRESENT BETWEEN THESE TWO CHANNELS OF HIGHER-
MOMENTUM FLOW...FROM THE CNTRL PLAINS INTO UPPER MS VALLEY. AT THE
SURFACE...AN AREA OF LOW PRESSURE AND ASSOCIATED TROUGH WILL MOVE
EAST ACROSS THE DAKOTAS AND NEB TODAY...EVENTUALLY MOVING THROUGH
OUR AREA TONIGHT.
SURFACE OBSERVATIONS AND SATELLITE DATA INDICATE THE PRESENCE OF
WIDESPREAD LOW CLOUDS AND FOG EARLY THIS MORNING OWING TO THE
SATURATED LOW-LEVEL WARM-ADVECTION REGIME PRESENT AHEAD OF THE
SURFACE TROUGH TO OUR WEST. WE WILL CONTINUE TO MONITOR THESE
OBSERVATIONS FOR THE NECESSITY OF A DENSE FOG ADVISORY EARLY
TODAY. THE ONSET OF DIURNAL HEATING AND RESULTANT DEEPENING/MIXING
OF THE BOUNDARY LAYER SHOULD RESULT IN THE FOG DISSIPATING BY MID-
MORNING WITH SOME AFTERNOON CLOUD BREAKS ALLOWING FOR TEMPERATURES
TO WARM INTO THE 60S. THIS WARMING AIR MASS COUPLED WITH DEWPOINTS
IN THE LOWER 50S WILL PROMOTE THE DEVELOPMENT OF A WEAKLY UNSTABLE
ENVIRONMENT BY AFTERNOON WITH MLCAPE VALUES OF A FEW HUNDRED J/KG.
HOWEVER...THE ABSENCE OF ANY APPRECIABLE LARGE-SCALE FORCING
MECHANISMS AND DISPLACEMENT OF THE SURFACE TROUGH TO THE WEST OF
THE AREA THROUGH THE PEAK OF THE DIURNAL HEATING CYCLE CASTS
CONSIDERABLE UNCERTAINTY ON SHOWER/TSTM POTENTIAL. AS SUCH...WILL
MAINTAIN SLIGHT CHANCE/LOW CHANCE POPS TODAY. WE WILL CONTINUE
SIMILAR POPS TONIGHT ALONG AND AHEAD OF THE SURFACE TROUGH/FRONT
WHICH WILL BE MOVING THROUGH THE AREA.
MONDAY INTO TUESDAY...AN UPPER-LEVEL JET STREAK WILL DEVELOP FROM
THE INTERIOR WEST THROUGH THE MID-MS VALLEY...CONTRIBUTING TO THE
CONSIDERABLE AMPLIFICATION OF A MID-LEVEL TROUGH OVER THE N-CNTRL
CONUS. WHILE SOME MID TO HIGH-LEVEL CLOUDINESS WILL EXIST MONDAY...A
DEEPENING LEE TROUGH OVER THE HIGH PLAINS WILL PROMOTE WARMING OF
THE LOW-LEVEL AIR MASS WITH HIGHS IN THE LOWER TO MID 70S. RECORD
HIGH TEMPERATURES ARE: OMAHA/81...LINCOLN/82 AND NORFOLK/81. A
WEAKLY UNSTABLE ENVIRONMENT WILL ONCE AGAIN DEVELOP BY
AFTERNOON...THOUGH ANY TSTM THREAT SHOULD REMAIN TO OUR WEST ALONG
THE SURFACE FRONT.
LARGE-SCALE FORCING FOR ASCENT WILL STRENGTHEN MARKEDLY MONDAY NIGHT
ALONG AND AHEAD OF THE INTENSIFYING LOW-LEVEL COLD
FRONT...SUPPORTING THE DEVELOPMENT OF SHOWERS AND A FEW TSTMS
WHICH COULD LINGER INTO TUESDAY ACROSS OUR ERN COUNTIES. MODEST
LOW-LEVEL COLD ADVECTION IN THE WAKE OF THE COLD FRONT WILL RESULT
IN COOLER TEMPERATURES TUESDAY...IN THE 50S. BREEZY TO
WINDY CONDITIONS CAN ALSO BE EXPECTED.
TUESDAY NIGHT INTO WEDNESDAY...A DEEP-LAYER CYCLONE EVOLVES OVER
THE UPPER MIDWEST WITH GENERALLY NWLY TROPOSPHERIC FLOW RESIDING
ACROSS THE MID-MO VALLEY. ANY MEANINGFUL PRECIPITATION CHANCES
SHOULD REMAIN TO OUR NORTHEAST WITH HIGHS ONCE AGAIN IN THE 50S.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 315 AM CDT SUN MAR 13 2016
AN UPPER-LEVEL JET STREAK FROM WRN CANADIAN INTO THE NRN INTER-
MOUNTAIN REGION AT THE ONSET OF THE EXTENDED PERIOD WILL DIG SEWD
INTO THE CNTRL ROCKIES BY LATE THIS UPCOMING WEEK...WITH A PIECE
OF THE UPPER LOW INITIALLY OVER THE UPPER MIDWEST RETROGRADING OR
REFORMING OVER THE DAKOTAS. BY NEXT WEEKEND...00Z MODEL GUIDANCE
SUGGESTS THAT A LARGER-SCALE TROUGH WILL EVOLVE OVER THE CNTRL
U.S...THE DETAILS OF WHICH VARY FROM MODEL TO MODEL.
THIS UPPER-AIR PATTERN EVOLUTION WILL PROMOTE THE SWD DEVELOPMENT
OF A SURFACE HIGH THROUGH THE LEE OF THE CANADIAN ROCKIES INTO NRN
HIGH PLAINS...USHERING IN A COLDER CONTINENTAL-POLAR AIR MASS
INTO THE REGION LATE THIS WEEK INTO NEXT WEEKEND. AS MENTIONED
ABOVE...MODEL VARIABILITY EXISTS WITH REGARD TO SPECIFIC DETAILS
OF THE SYNOPTIC PATTERN. THEREFORE...WE WILL INCLUDE LOW-
PROBABILITY PRECIPITATION CHANCES --INCLUDING THE POTENTIAL FOR
LIGHT SNOW-- NEXT WEEKEND.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1220 PM CDT SUN MAR 13 2016
CEILINGS SHOULD CONTINUE TO LIFT INTO THE MVFR CATEGORY THIS AFTN.
MODELS CONTINUE TO SHOW DECREASING LOW LEVEL RH...SO IT SHOULD
TREND TOWARD VFR THIS EVENING. FOG APPEARS POSSIBLE LATE TONIGHT
SO DID INCLUDE SOME VSBY RESTRICTION TOWARD SUNRISE. HIGHEST FOG
POTENTIAL THOUGH WILL REMAIN NORTHEAST OF KOFK AND EAST OF KOMA.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
UPDATE...MILLER
SHORT TERM...MEAD
LONG TERM...MEAD
AVIATION...MILLER
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
629 AM CDT SUN MAR 13 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 356 AM CDT SUN MAR 13 2016
TODAY AND TONIGHT...LOW PRESSURE MOVES EAST TODAY WITH THE STRATUS
AND ISOLATED SHOWERS CLEARING THE FAR EASTERN EDGE OF THE FCST AREA
LATE THIS AFTERNOON. THE HRRR SUGGESTS SUFFICIENT INSTABILITY FOR
ISOLATED THUNDERSTORMS THIS AFTN EAST OF HIGHWAY 183. NO STORMS ARE
EXPECTED TO BECOME SEVERE WITH SBCAPE BELOW 1000 J/KG.
WEAK PACIFIC HIGH PRESSURE BUILDS INTO THE REGION TONIGHT HOWEVER
MID LEVEL CLOUDS MOVE IN AFTER MIDNIGHT DAMPENING RADIATIONAL
COOLING. LOWS TONIGHT WILL FALL INTO THE 30S TO LOWER 40S. HIGHS
TODAY RISE INTO THE UPPER 60S TO LOWER 70S ACCORDING TO THE RAP AND
HRRR MODELS WHICH ARE CLOSE TO THE WARMER MAV AND ECS GUIDANCE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 356 AM CDT SUN MAR 13 2016
MID RANGE...MONDAY AND TUESDAY...MAIN FORECAST CHALLENGES ARE
TEMPERATURES AND PRECIPITATION AS A STRONG COLD FRONT TRAVERSES THE
AREA. DOWNSLOPE FLOW AND 850HPA TEMPS OF 12-14C AND SOUTHWEST
SURFACE WINDS ON MONDAY WILL HELP PUSH TEMPERATURES WELL ABOVE
NORMAL. TRENDED TOWARD THE MAV FOR MAX TEMPS...WHICH GENERALLY
INCREASED HIGHS A DEGREE OR TWO ACROSS THE FORECAST AREA. LOOKING AT
UPPER 60S IN THE PANHANDLE AND LOWER TO MID 70S EAST. FGEN FORCING
AND MOISTURE INCREASE DURING THE DAY AS THE SURFACE FRONT AND MID
LEVEL SHORTWAVE APPROACH FROM THE WEST. CONTINUED THE MENTION OF
SCHC THUNDER MONDAY AFTERNOON DUE TO STEEP LOW LEVEL LAPSE RATES AND
SOME LIFT. SEVERE THREAT MARGINAL AT BEST AS MUCAPE REMAINS UNDER
500J/KG AND LIFTED INDEX -1C OR HIGHER. BEST CHANCE OF PRECIP MONDAY
NIGHT FOR EASTERN HALF OF FORECAST AREA...WHERE NAM SHOWS MIXING
RATIOS NEAR 8G/KG VERSUS 4G/KG FARTHER WEST DURING THE DAY. LOWS
DROP BELOW FREEZING IN THE PANHANDLE TUESDAY MORNING...BUT FORECAST
SOUNDINGS INDICATE TEMP PROFILES FAVORING RAIN FOR MUCH OF NIGHT.
SFC WET BULB DROP BELOW 0C AS MOISTURE TAPERS...SO A BRIEF PERIOD OF
MIX/SWITCH OVER TO SNOW TO END. SUBSIDENCE TAKES HOLD FOR PART OF
TUESDAY BEFORE A SECOND SURGE OF LIFT AND FRONTOGENESIS ARRIVES TUE
AFTN/EVE. GOOD MOMENTUM TRANSFER AND CAA BEHIND THE FRONT...850HPA
WINDS 30-40 KTS FOR MUCH OF THE DAY AND TEMPS NEAR 4C.
LONG RANGE...WEDNESDAY THROUGH SATURDAY...WESTERN NEBRASKA LIES IN
BROAD NORTHWEST FLOW OR QUASI ZONAL FLOW TO START. LATE WEEK...AN
UPPER LOW RETROGRADES ACROSS THE NORTHERN PLAINS AND A LEESIDE SFC
LOW DEVELOPS. SEVERAL PIECES OF ENERGY SWING THROUGH THE
AREA...KEEPING TEMPERATURES CLOSER TO NORMAL AND PRECIP CHANCES IN
SCHC CATEGORY IN THE NORTH WED AND THU AND IN THE SOUTH ON FRIDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 629 AM CDT SUN MAR 13 2016
THE MVFR/IFR CIGS APPEAR TO BE SHIFTING EAST FASTER THAN THE
MODELS FORECAST. IT IS POSSIBLE VFR WILL BE WIDESPREAD BY 16Z
THIS MORNING AND CONTINUE THROUGH EARLY MONDAY MORNING. ISOLATED
THUNDERSTORMS MAY DEVELOP THIS AFTN ALONG AND EAST OF HIGHWAY 281.
PACIFIC HIGH PRESSURE WILL BUILD INTO THE FCST AREA THIS AFTERNOON
AND THIS EVENING FOLLOWED BY AN INCREASE IN MIDLEVEL
CLOUDINESS...CURRENTLY LOCATED ACROSS WY AND ID.
&&
.FIRE WEATHER...
ISSUED AT 435 AM CDT SUN MAR 13 2016
OPPORTUNITIES FOR CRITICAL FIRE CONDITIONS MAY PRESENT THEMSELVES
MONDAY THROUGH WEDNESDAY. HUMIDITY APPEARS TO BE A LIMITING
FACTOR NEAR 20 PERCENT ACROSS WRN NEB DURING THIS TIME. WINDS
WILL BE MORE FAVORABLE FOR FIRE GROWTH TUESDAY AND WEDNESDAY.
LATER FORECASTS SHOULD PREDICT AREAS OF LOWEST AFTERNOON
HUMIDITY...NEAR OR BELOW 15 PERCENT.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...SNIVELY
AVIATION...CDC
FIRE WEATHER...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
435 AM CDT SUN MAR 13 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 356 AM CDT SUN MAR 13 2016
TODAY AND TONIGHT...LOW PRESSURE MOVES EAST TODAY WITH THE STRATUS
AND ISOLATED SHOWERS CLEARING THE FAR EASTERN EDGE OF THE FCST AREA
LATE THIS AFTERNOON. THE HRRR SUGGESTS SUFFICIENT INSTABILITY FOR
ISOLATED THUNDERSTORMS THIS AFTN EAST OF HIGHWAY 183. NO STORMS ARE
EXPECTED TO BECOME SEVERE WITH SBCAPE BELOW 1000 J/KG.
WEAK PACIFIC HIGH PRESSURE BUILDS INTO THE REGION TONIGHT HOWEVER
MID LEVEL CLOUDS MOVE IN AFTER MIDNIGHT DAMPENING RADIATIONAL
COOLING. LOWS TONIGHT WILL FALL INTO THE 30S TO LOWER 40S. HIGHS
TODAY RISE INTO THE UPPER 60S TO LOWER 70S ACCORDING TO THE RAP AND
HRRR MODELS WHICH ARE CLOSE TO THE WARMER MAV AND ECS GUIDANCE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 356 AM CDT SUN MAR 13 2016
MID RANGE...MONDAY AND TUESDAY...MAIN FORECAST CHALLENGES ARE
TEMPERATURES AND PRECIPITATION AS A STRONG COLD FRONT TRAVERSES THE
AREA. DOWNSLOPE FLOW AND 850HPA TEMPS OF 12-14C AND SOUTHWEST
SURFACE WINDS ON MONDAY WILL HELP PUSH TEMPERATURES WELL ABOVE
NORMAL. TRENDED TOWARD THE MAV FOR MAX TEMPS...WHICH GENERALLY
INCREASED HIGHS A DEGREE OR TWO ACROSS THE FORECAST AREA. LOOKING AT
UPPER 60S IN THE PANHANDLE AND LOWER TO MID 70S EAST. FGEN FORCING
AND MOISTURE INCREASE DURING THE DAY AS THE SURFACE FRONT AND MID
LEVEL SHORTWAVE APPROACH FROM THE WEST. CONTINUED THE MENTION OF
SCHC THUNDER MONDAY AFTERNOON DUE TO STEEP LOW LEVEL LAPSE RATES AND
SOME LIFT. SEVERE THREAT MARGINAL AT BEST AS MUCAPE REMAINS UNDER
500J/KG AND LIFTED INDEX -1C OR HIGHER. BEST CHANCE OF PRECIP MONDAY
NIGHT FOR EASTERN HALF OF FORECAST AREA...WHERE NAM SHOWS MIXING
RATIOS NEAR 8G/KG VERSUS 4G/KG FARTHER WEST DURING THE DAY. LOWS
DROP BELOW FREEZING IN THE PANHANDLE TUESDAY MORNING...BUT FORECAST
SOUNDINGS INDICATE TEMP PROFILES FAVORING RAIN FOR MUCH OF NIGHT.
SFC WET BULB DROP BELOW 0C AS MOISTURE TAPERS...SO A BRIEF PERIOD OF
MIX/SWITCH OVER TO SNOW TO END. SUBSIDENCE TAKES HOLD FOR PART OF
TUESDAY BEFORE A SECOND SURGE OF LIFT AND FRONTOGENESIS ARRIVES TUE
AFTN/EVE. GOOD MOMENTUM TRANSFER AND CAA BEHIND THE FRONT...850HPA
WINDS 30-40 KTS FOR MUCH OF THE DAY AND TEMPS NEAR 4C.
LONG RANGE...WEDNESDAY THROUGH SATURDAY...WESTERN NEBRASKA LIES IN
BROAD NORTHWEST FLOW OR QUASI ZONAL FLOW TO START. LATE WEEK...AN
UPPER LOW RETROGRADES ACROSS THE NORTHERN PLAINS AND A LEESIDE SFC
LOW DEVELOPS. SEVERAL PIECES OF ENERGY SWING THROUGH THE
AREA...KEEPING TEMPERATURES CLOSER TO NORMAL AND PRECIP CHANCES IN
SCHC CATEGORY IN THE NORTH WED AND THU AND IN THE SOUTH ON FRIDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1123 PM CST SAT MAR 12 2016
FOR THE KLBF TERMINAL...EXPECT IFR TO MVFR CONDS OVERNIGHT INTO
MID MORNING SUNDAY WITH CIGS RANGING FROM 700 TO 1500 FT AGL.
SKIES WILL SCATTER OUT BY LATE MORNING WITH CLEAR SKIES TO
SCATTERED CLOUDS AON 25000 FT AGL EXPECTED THROUGH SUNSET SUNDAY
EVENING. CLEAR SKIES ARE EXPECTED AFTER SUNSET. FOR THE KVTN
TERMINAL...EXPECT MVFR CIGS AROUND 1200 FT AGL THROUGH MID MORNING
SUNDAY. LOW CLOUDS WILL SCATTER OUT BY LATE MORNING WITH BROKEN
CIGS AROUND 20000 FT AGL EXPECTED SUNDAY AFTERNOON. SKIES WILL
CLEAR AFTER 23Z SUNDAY AT THE KVTN TERMINAL.
&&
.FIRE WEATHER...
ISSUED AT 435 AM CDT SUN MAR 13 2016
OPPORTUNITIES FOR CRITICAL FIRE CONDITIONS MAY PRESENT THEMSELVES
MONDAY THROUGH WEDNESDAY. HUMIDITY APPEARS TO BE A LIMITING
FACTOR NEAR 20 PERCENT ACROSS WRN NEB DURING THIS TIME. WINDS
WILL BE MORE FAVORABLE FOR FIRE GROWTH TUESDAY AND WEDNESDAY.
LATER FORECASTS SHOULD PREDICT AREAS OF LOWEST AFTERNOON
HUMIDITY...NEAR OR BELOW 15 PERCENT.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...SNIVELY
AVIATION...BUTTLER
FIRE WEATHER...CDC
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
356 AM CDT SUN MAR 13 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 356 AM CDT SUN MAR 13 2016
TODAY AND TONIGHT...LOW PRESSURE MOVES EAST TODAY WITH THE STRATUS
AND ISOLATED SHOWERS CLEARING THE FAR EASTERN EDGE OF THE FCST AREA
LATE THIS AFTERNOON. THE HRRR SUGGESTS SUFFICIENT INSTABILITY FOR
ISOLATED THUNDERSTORMS THIS AFTN EAST OF HIGHWAY 183. NO STORMS ARE
EXPECTED TO BECOME SEVERE WITH SBCAPE BELOW 1000 J/KG.
WEAK PACIFIC HIGH PRESSURE BUILDS INTO THE REGION TONIGHT HOWEVER
MID LEVEL CLOUDS MOVE IN AFTER MIDNIGHT DAMPENING RADIATIONAL
COOLING. LOWS TONIGHT WILL FALL INTO THE 30S TO LOWER 40S. HIGHS
TODAY RISE INTO THE UPPER 60S TO LOWER 70S ACCORDING TO THE RAP AND
HRRR MODELS WHICH ARE CLOSE TO THE WARMER MAV AND ECS GUIDANCE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 356 AM CDT SUN MAR 13 2016
MID RANGE...MONDAY AND TUESDAY...MAIN FORECAST CHALLENGES ARE
TEMPERATURES AND PRECIPITATION AS A STRONG COLD FRONT TRAVERSES THE
AREA. DOWNSLOPE FLOW AND 850HPA TEMPS OF 12-14C AND SOUTHWEST
SURFACE WINDS ON MONDAY WILL HELP PUSH TEMPERATURES WELL ABOVE
NORMAL. TRENDED TOWARD THE MAV FOR MAX TEMPS...WHICH GENERALLY
INCREASED HIGHS A DEGREE OR TWO ACROSS THE FORECAST AREA. LOOKING AT
UPPER 60S IN THE PANHANDLE AND LOWER TO MID 70S EAST. FGEN FORCING
AND MOISTURE INCREASE DURING THE DAY AS THE SURFACE FRONT AND MID
LEVEL SHORTWAVE APPROACH FROM THE WEST. CONTINUED THE MENTION OF
SCHC THUNDER MONDAY AFTERNOON DUE TO STEEP LOW LEVEL LAPSE RATES AND
SOME LIFT. SEVERE THREAT MARGINAL AT BEST AS MUCAPE REMAINS UNDER
500J/KG AND LIFTED INDEX -1C OR HIGHER. BEST CHANCE OF PRECIP MONDAY
NIGHT FOR EASTERN HALF OF FORECAST AREA...WHERE NAM SHOWS MIXING
RATIOS NEAR 8G/KG VERSUS 4G/KG FARTHER WEST DURING THE DAY. LOWS
DROP BELOW FREEZING IN THE PANHANDLE TUESDAY MORNING...BUT FORECAST
SOUNDINGS INDICATE TEMP PROFILES FAVORING RAIN FOR MUCH OF NIGHT.
SFC WET BULB DROP BELOW 0C AS MOISTURE TAPERS...SO A BRIEF PERIOD OF
MIX/SWITCH OVER TO SNOW TO END. SUBSIDENCE TAKES HOLD FOR PART OF
TUESDAY BEFORE A SECOND SURGE OF LIFT AND FRONTOGENESIS ARRIVES TUE
AFTN/EVE. GOOD MOMENTUM TRANSFER AND CAA BEHIND THE FRONT...850HPA
WINDS 30-40 KTS FOR MUCH OF THE DAY AND TEMPS NEAR 4C.
LONG RANGE...WEDNESDAY THROUGH SATURDAY...WESTERN NEBRASKA LIES IN
BROAD NORTHWEST FLOW OR QUASI ZONAL FLOW TO START. LATE WEEK...AN
UPPER LOW RETROGRADES ACROSS THE NORTHERN PLAINS AND A LEESIDE SFC
LOW DEVELOPS. SEVERAL PIECES OF ENERGY SWING THROUGH THE
AREA...KEEPING TEMPERATURES CLOSER TO NORMAL AND PRECIP CHANCES IN
SCHC CATEGORY IN THE NORTH WED AND THU AND IN THE SOUTH ON FRIDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1123 PM CST SAT MAR 12 2016
FOR THE KLBF TERMINAL...EXPECT IFR TO MVFR CONDS OVERNIGHT INTO
MID MORNING SUNDAY WITH CIGS RANGING FROM 700 TO 1500 FT AGL.
SKIES WILL SCATTER OUT BY LATE MORNING WITH CLEAR SKIES TO
SCATTERED CLOUDS AON 25000 FT AGL EXPECTED THROUGH SUNSET SUNDAY
EVENING. CLEAR SKIES ARE EXPECTED AFTER SUNSET. FOR THE KVTN
TERMINAL...EXPECT MVFR CIGS AROUND 1200 FT AGL THROUGH MID MORNING
SUNDAY. LOW CLOUDS WILL SCATTER OUT BY LATE MORNING WITH BROKEN
CIGS AROUND 20000 FT AGL EXPECTED SUNDAY AFTERNOON. SKIES WILL
CLEAR AFTER 23Z SUNDAY AT THE KVTN TERMINAL.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...SNIVELY
AVIATION...BUTTLER
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
847 PM PDT MON MAR 14 2016
.SYNOPSIS...LOCALLY WINDY CONDITIONS WILL PERSIST THROUGH THIS
EVENING AS A PACIFIC STORM SYSTEM EXITS THE AREA TO THE EAST. DRY
AND WARM CONDITIONS ARE EXPECTED TUESDAY THROUGH FRIDAY AS HIGH
PRESSURE BUILDS ALONG THE WEST COAST.
&&
UPDATE...MOSTLY A QUIET EVENING ACROSS THE AREA. ALL WIND HAZARD
PRODUCTS HAVE EXPIRED AND WINDS WILL CONTINUE TO DECREASE. THE SKY
WILL FEATURE OCCASIONAL HIGH CLOUDS OVERNIGHT. NO UPDATES NEEDED AT
THIS TIME.
&&
.AVIATION...FOR MCCARRAN...LIGHT SOUTHWEST TO WEST WINDS MAINLY
UNDER 8 KTS THROUGH TUESDAY MORNING. WINDS WILL FAVOR A NORTHEAST
DIRECTION TOMORROW AFTERNOON WITH SPEEDS REMAINING LIGHT. PASSING
HIGH CLOUDS EXPECTED THROUGH THE PERIOD.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...WEST WINDS SHOULD DECREASE TO 10-15 KTS BY LATE THIS
EVENING AT KDAG, WITH DIURNAL PROCESSES TAKING OVER DURING THE DAY
TOMORROW. LIGHT SOUTHERLY TO WESTERLY FLOW AT KEED AND KIFP SHOULD
TRANSITION TO STRONGER NORTHERLY FLOW BY EARLY TUESDAY MORNING WITH
SPEEDS 15-25 KTS AND GUSTS TO 30 KTS AT KIFP. WINDS FAVORING DIURNAL
PROCESSES ARE EXPECTED AT KVGT AND KHND THROUGH THE PERIOD. PASSING
HIGH CLOUDS THROUGHOUT THE REGION THROUGH TUESDAY.
&&
.PREVIOUS DISCUSSION...238 PM PDT...
.DISCUSSION...TONIGHT THROUGH MONDAY...
THE SHORTWAVE TROUGH MOVING OUT OF NORTHEAST NEVADA INTO UTAH TODAY
HAS BEEN GENERATING GUSTY WINDS ACROSS PORTIONS OF THE CWA ABOUT AS
EXPECTED. ADVISORY LEVEL WINDS HAVE BEEN NOTED IN THE OWENS VALLEY
AND PORTIONS OF SAN BERNARDINO COUNTY. GOLDFIELD SUMMIT ALSO
REPORTED A WIND GUST OF 41 MPH. THE REMAINDER OF THE AREA ACROSS
ESMERALDA...CENTRAL NYE AND LINCOLN COUNTIES WAS SEEING SOME
INCREASE IN WINDS BUT NOT ADVISORY LEVEL SO FAR. THE LATEST HRRR
STILL SUPPORTS A FEW HOURS OF ADVISORY LEVEL WINDS LATE THIS
AFTERNOON THERE. MOST AREAS WILL TRANSITION TO NORTHERLY WINDS
TONIGHT AND TUESDAY BEHIND THE EXITING SHORTWAVE WITH LOCALLY BREEZY
CONDITIONS DOWN THE COLORADO RIVER TUESDAY. MEANWHILE...VARYING
AMOUNTS OF HIGH LEVEL CLOUDS WILL CONTINUE TO WORK ACROSS THE AREA
THROUGH TUESDAY. A RIDGE OF HIGH PRESSURE WILL GRADUALLY BUILD ALONG
THE WEST COAST TUESDAY THROUGH FRIDAY LEADING TO WARM AND DRY
CONDITIONS ALONG WITH SOME NORTHERLY BREEZES DOWN THE COLORADO RIVER
VALLEY. THE STRONGEST WINDS LOOK TO BE WEDNESDAY FROM LAUGHLIN-
BULLHEAD CITY DOWN TO HAVASU AND WE MAY HAVE TO MONITOR FOR POSSIBLE
WIND ADVISORY OR LAKE WIND ADVISORY POSSIBILITIES. THE UPPER RIDGE
WILL TRAVERSE THE AREA OVER THE WEEKEND WITH MORE WARM AND DRY
CONDITIONS. HIGH TEMPERATURES WILL BE PUSHING 80 DEGREES IN THE LAS
VEGAS VALLEY BY SUNDAY. WE MAY SEE SOME LOCALLY BREEZY
SOUTH/SOUTHWEST WINDS LATE SUNDAY AS THE RIDGE AXIS SHIFTS JUST EAST
OF THE AREA. AT THIS TIME IT DOES NOT APPEAR THAT ADVISORY LEVEL
WINDS ARE LIKELY. A DRY SOUTHWEST FLOW WILL BE OVER THE AREA MONDAY
WITH SOME INCREASE IN SOUTHWEST SURFACE WINDS. THERE WILL ALSO
LIKELY BE SOME INCREASE IN HIGH CLOUD COVER WHILE TEMPERATURES
REMAIN WARM. &&
.SPOTTER INFORMATION STATEMENT...SPOTTER ACTIVATION NOT EXPECTED.
HOWEVER STRONG WINDS ARE EXPECTED ACROSS PORTIONS OF THE AREA AND
SPOTTERS SHOULD REPORT ANY SIGNIFICANT WEATHER OR WEATHER-RELATED
DAMAGE ACCORDING TO STANDARD OPERATING PROCEDURES.
&&
$$
UPDATE/AVIATION...SALMEN
PREV DISC...
DISCUSSION...HARRISON
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
[top]
Area Forecast Discussion
National Weather Service Reno NV
756 PM PDT MON MAR 14 2016
.UPDATE...
Winds continue to diminish over the region as the pressure
gradient relaxes. The Lake Wind Advisories for Lake Tahoe and
Pyramid Lake have been allowed to expire. Conditions on Lake Tahoe
will remain a little choppy until after midnight when the winds
drop further.
&&
.PREVIOUS DISCUSSION... /Issued 238 PM PDT MON MAR 14 2016/
SYNOPSIS...
Strong gusty winds continued this afternoon but are expected to
subside tonight as high pressure moves into the region. Gradual
warming is expected this week with temperatures well above normal by
weeks end. Gusty winds may return next weekend with potential for
light precipitation in the northern Sierra early next week.
SHORT TERM...
Strong gusty winds continued across the region today associated with
cold front nearby and enhanced pressure gradient. Some areas in
Mono/Mineral Counties hit what would normally be Red Flag criteria
with humidities below 10% and gusts 40-60 mph. This included the
Mammoth Airport for several hours. Winds will drop off rather
quickly tonight as gradient relaxes with incoming high pressure.
That shows up well in the HRRR guidance. Could still see a few light
rain/snow showers early this evening in far NE Cal and NW Nev but no
accumulations.
Tuesday looks to be a transition day, with gusty W/NW winds likely
north of a Susanville-Fallon line with the retreating front still in
the vicinity. Building high pressure just off the west coast will
yield warming temperatures aloft over the region and a weak NE low
level flow Wednesday-Thursday. Warming in valleys will be gradual as
a result but strong inversions are not anticipated. Overall looks to
be a prime week to get outdoor projects or yard work done. -Chris
LONG TERM...Friday through Monday...
Forecast models continue to show the ridge axis shifting across the
Sierra and western Nevada on Friday and Saturday. Dry conditions
expected through the end of the week along with light northeast,
east winds for the Sierra and western Nevada. Temperatures will
climb into the upper 60s and near 70 degrees by Saturday as the
ridge axis shifts eastward and allows light west winds to return.
There is potential for the ridge to break down by late Saturday into
Sunday which will allow the large scale pattern to become a bit more
active again. Both operational models are targeting an upper level
jet along with some moisture towards the west coast. There is some
uncertainty where the jet will land, anywhere from the Lake Tahoe
Basin up towards the Pacific Northwest. There is some potential for
valley rain and mountain snow showers for late Sunday into Monday.
Edan
AVIATION...
The strong wind gusts around 60-80 kts across the Sierra ridges from
this morning will continue to diminish through the afternoon and
evening. Terminals in the eastern Sierra and western Nevada should
expect wind gusts decreasing to around 15-25 kts by this evening.
Only terminal that may still see wind gusts later in the evening
would be KMMH.
VFR conditions are expected to prevail across the area by this
afternoon and evening. Conditions have dried out considerably, so we
don`t anticipate fog forming in the Sierra valleys. Edan
&&
.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 WILMINGTON NC
846 PM EDT MON MAR 14 2016
.SYNOPSIS...
AN UPPER LEVEL IMPULSE WILL BRING A CHANCE FOR SHOWERS AND
THUNDERSTORMS THIS EVENING. VERY WARM TEMPERATURES EXPECTED
THROUGH MID WEEK...WITH RECORD HIGHS POSSIBLE ON WEDNESDAY. A
COLD FRONT WILL BRING A CHANCE FOR SHOWERS THURSDAY NIGHT INTO
FRIDAY...FOLLOWED BY MUCH COOLER TEMPERATURES INTO THE WEEKEND.
LOW PRESSURE MOVING NEARBY WILL BRING A GOOD CHANCE FOR RAIN ON
SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
AS OF 730 PM MONDAY...WATER VAPOR IMAGERY SHOWS SHORTWAVE
PROGRESSING E-NE WHILE COLD FRONT REMAINS DRAPED FROM WEST TO EAST
ACROSS NORTH CAROLINA...NORTH OF FORECAST AREA. ALL STORMS WERE
ALLIGNED WITH IMPULSE WEST OF AREA AND NORTH ALONG FRONTAL
BOUNDARY. OTHERWISE QUIET OVER LOCAL AREA FOR THE MOMENT. LOOKING
AT RADAR AND LATEST HRRR MODEL DATA...SHOULD SEE STORMS REACHING
JUST WEST OF I95 CORRIDOR BETWEEN 9 AND 10 PM. SPC STILL HAS SOME
OF THE AREA...MAINLY NORTH AND WEST IN A SLIGHT RISK. GOOD CAPE IN
THE MINUS TEN TO MINUS THIRTY LAYER WARRANTS A HAIL RISK. INVERTED
V SOUNDINGS AND DRY AIR ALOFT WARRANT A WIND THREAT. THE SYSTEM
MOVES OFF LATE TONIGHT WITH CLEARING SKIES DEVELOPING. OPTED FOR
THE WARMER GUIDANCE FOR OVERNIGHT LOWS AS TEMPERATURES HAVE BEEN
ABOVE SOMETIMES WELL ABOVE THE WARMEST NUMBERS FOR SOME TIME.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
AS OF 230 PM MONDAY...A WESTERLY FLOW WILL DEVELOP AT THE MID
LEVELS TUESDAY AND TURN SLIGHTLY TO THE SOUTHWEST ON WEDNESDAY.
THIS WILL KEEP THE SUPPLY OF WARM AIR ADVECTING INTO THE REGION.
THE PRESSURE PATTERN WILL GENERALLY SHOW A WESTERLY FLOW AS WELL.
A FADING COLD FRONT WILL MOVE CLOSER TO THE AREA LATE IN THE
PERIOD. NO POPS TO SPEAK OF THROUGH THE PERIOD AS PW REMAINS WELL
BELOW ONE INCH. STILL LOOKS LIKE A POSSIBILITY OF RECORD BREAKING
HEAT WEDNESDAY WITH 850MB AIR OF 15 DEGREES C ADVECTS INTO THE
AREA. WITH THE RECENT AND SOMEWHAT SUSTAINED TREND OF GUIDANCE
BEING TOO COOL WENT A FEW DEGREES ABOVE ACROSS THE BOARD.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 230 PM MONDAY...ONE LAST VERY WARM DAY THURSDAY BEFORE A
REGIME CHANGE OCCURS WITH COOL AND MORE UNSETTLED WEATHER FOR THE
REMAINDER OF THE EXTENDED.
PRE-FRONTAL AIRMASS THURSDAY WILL LEAD TO ONE MORE WELL ABOVE NORMAL
DAY WITH HIGHS AROUND OR JUST ABOVE 80. A COLD FRONT WILL THEN MOVE
ACROSS THE AREA THURSDAY NIGHT...WITH MUCH COOLER TEMPERATURES
FORECAST LEADING INTO THE WEEKEND. GUIDANCE CONTINUES TO BE VASTLY
DIFFERENT IN ITS DEPICTION OF SHOWERS ALONG THE FRONT...BUT FAVOR
THE GFS WHICH IS THE WETTEST DUE TO A BRIEF PERIOD OF MUCH HIGHER
PWATS AHEAD OF THE FROPA...AND THIS MATCHES UP BEST WITH WPC QPF
GRAPHICS. THIS FRONT WILL THEN STALL SOUTH OF THE AREA FRIDAY INTO
SATURDAY...WITH WEAK WEDGE OF HIGH PRESSURE EXPECTED TO DEVELOP DOWN
THE COAST BEHIND IT. THIS WILL BRING COOLER AND PARTLY TO MOSTLY
CLOUDY CONDITIONS...WITH HIGHS FALLING TO SEASONABLE OR POTENTIALLY
SLIGHTLY BELOW...ESPECIALLY ON SATURDAY. MUCH OF THE FRI/SAT PERIOD
IS EXPECTED TO BE DRY HOWEVER...BEFORE A SOUTHERN STREAM SHORTWAVE
INTERACTS WITH THE STALLED BOUNDARY TO LIFT A SURFACE LOW NORTH
ACROSS THE AREA SATURDAY NIGHT INTO SUNDAY. GFS/ECM ARE IN MUCH
BETTER AGREEMENT WITH THIS SOLUTION NOW...SO THE MUCH FASTER CMC IS
IGNORED...AGAIN AGREEING WITH THE WPC CONSENSUS FROM THE EPD. A
PERIOD OF RAINFALL WILL ACCOMPANY THIS LOW PRESSURE THROUGH SUNDAY
BEFORE ITS ASSOCIATED COLD FRONT DRAGS OFFSHORE WITH DRIER AND EVEN
COOLER CONDITIONS TO FOLLOW FOR THE BEGINNING OF NEXT WEEK.
&&
.AVIATION /22Z MONDAY THROUGH SATURDAY/...
AS OF 18Z... MVFR CIGS LIKELY WORST CASE THROUGH THE PERIOD UNLESS
THUNDERSTORMS BECOME MORE WIDESPREAD THAN ANTICIPATED. AFTERNOON
STORMS LIKELY ONLY TO BRIEFLY AFFECT LBT AND MAYBE ILM. OVERNIGHT
STORMS MOVING IN FROM THE WEST AT ROUGHLY 03Z BUT ANY IFR TO BE TOO
SHORT-LIVED TO WARRANT BEING IN ANY TAFS AT THIS TIME. ALSO TOUGH TO
SAY WHICH TERMINALS IF ANY SEE THE ACTIVITY. MOST LIKELY
CANDIDATES SEEM TO BE FLO AND LBT.
EXTENDED OUTLOOK...MVFR POSSIBLE WITH SCT SHOWERS THURSDAY NIGHT
INTO FRIDAY...OTHERWISE MAINLY VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 730 PM MONDAY...SOUTHWEST WINDS AROUND 10 TO 15 KTS WILL CONTINUE
INTO THE EVENING...BUT WILL INCREASE AND VEER TO THE WEST AFTER UPPER
IMPULSE MOVES THROUGH LATE THIS EVENING. SEAS WILL SPIKE UP A
BIT...BUT HIGHEST SEAS WILL REMAIN WELL OFF SHORE DUE TO WESTERLY
WINDS. OVERALL EXPECT SEAS IN THE 2 TO 4 FT RANGE BUT MAY SEE A FEW
5 FTERS IN OUR OUTER WATERS.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 230 PM MONDAY...INITIALLY A WESTERLY FLOW WILL BE IN PLACE
WITH SPEEDS OF 15-20 KNOTS. AS THE GRADIENT PRODUCING THIS WIND
FADES...A SOUTH TO SOUTHWEST FLOW OF 10-15 KNOTS DEVELOPS
WEDNESDAY AS A FRONT APPROACHES WELL TO THE WEST AND WEAK HIGH
PRESSURE DRIFTS OFFSHORE. SEAS WILL GENERALLY BE 2-4 FEET.
LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 230 PM MONDAY...SW WINDS OF 10-15 KTS WILL ENVELOP THE
WATERS THROUGH THURSDAY EVENING AHEAD OF A COLD FRONT. THIS FRONT
WILL PUSH OFFSHORE THURSDAY NIGHT...ACCOMPANIED BY A WIND SHIFT TO
THE NW WITH A REDUCTION IN SPEED. WEAK WEDGE OF HIGH PRESSURE WILL
PUSH DOWN THE COAST FRIDAY WITH CONTINUED LIGHT N TO NE WINDS
ACROSS THE WATERS...BEFORE SPEEDS INCREASE AHEAD OF A DEVELOPING
LOW PRESSURE SYSTEM ON SATURDAY. NE WINDS WILL RISE TO AROUND 15
KTS AND THEN VEER TO THE EAST AND SOUTH LATE IN THE PERIOD AS THE
SURFACE LOW PRESSURE MOVES ALONG THE COAST. SEAS WILL REMAIN LOW-
AMPLITUDE THURSDAY AND FRIDAY...2-3 FT THURSDAY AND JUST 1-2 FT
FRIDAY WITHIN THE WEAKENED GRADIENT. AS WINDS INCREASE AND TURN TO
THE SOUTH ON SATURDAY...WAVE HEIGHTS WILL BUILD RAPIDLY...BECOMING
3-5 FT LATE IN THE PERIOD WITH ISOLATED 6 FTERS POSSIBLE...AND AN
SCA MAY BE REQUIRED.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...RGZ
SHORT TERM...SHK
LONG TERM...JDW
AVIATION...MBB
AREA FORECAST DISCUSSION
NWS RALEIGH NC
733 PM EDT MON MAR 14 2016
.SYNOPSIS... AN UPPER LEVEL TROUGH WILL CROSS OUR REGION THROUGH
TONIGHT...BRINGING UNSETTLED WEATHER. A WEAK FRONTAL ZONE WILL HOVER
NEAR THE NORTH CAROLINA VIRGINIA BORDER THROUGH TUESDAY MORNING...
BEFORE LIFTING NORTHWARD AS A WARM FRONT TUESDAY AFTERNOON. A COLD
FRONT WILL DROP SOUTHEAST INTO THE AREA WEDNESDAY NIGHT...STALL OUT
OVER THE CAROLINAS THROUGH THURSDAY...THEN PUSH TO OUR SOUTHEAST
THURSDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 220 PM MONDAY...
WITH THE EXCEPTION OF THE LOW STRATUS STILL IN PLACE NORTH OF THE
BOUNDARY ACROSS THE FAR NRN TIER OF NC... THE STRATUS ELSEWHERE HAS
LIFTED AND MIXED OUT... ALLOWING FOR GOOD HEATING OVER THE SRN TWO
THIRDS OF THE FORECAST AREA. CONVECTION IS UNDERWAY ACROSS THE
CENTRAL/SRN PIEDMONT AND WRN SANDHILLS... WITH SHOWERS POPPING UP
FROM THE TRIANGLE SW TOWARD ROCKINGHAM. THESE WILL INCREASE IN
COVERAGE AND INTENSITY AS THEY HEAD ENE INTO MARKEDLY MORE MOIST
(DEWPOINTS IN THE 60S) AND UNSTABLE AIR IN THE ERN SANDHILLS AND
COASTAL PLAIN OVER THE NEXT SEVERAL HOURS. WEAK VORTICITY OVER THE
ERN CAROLINAS -- SE OF THE POTENT UPPER WAVE NOW OVER CENTRAL KY/TN -
- AND ITS ATTENDANT DPVA ALONG WITH A MAX IN STJ-INDUCED UPPER
DIVERGENCE WILL PROVIDE EXTRA DYNAMIC SUPPORT FOR THIS CONVECTION.
LOW LEVEL LAPSE RATES ARE ALREADY NEAR 7.5 C/KM AND RISING... WITH
INCOMING MID LEVEL LAPSE RATES OF 7-7.5 C/KM... AND MLCAPE IS
ALREADY UP TO 1500 J/KG WITH 40 KTS OF EFFECTIVE DEEP LAYER SHEAR...
SO SEE NO REASON WHY THESE WON`T CONTINUE TO GROW UPSCALE...
PARTICULARLY WITH -10C TO -30C LAYER CAPE UP TO 400 J/KG. WILL FOCUS
HIGHEST POPS FROM THE TRIANGLE TO THE SOUTH AND EAST THROUGH THE
REST OF THE AFTERNOON. THEN... THE NEGATIVELY TILTED SHORTWAVE
TROUGH WILL SWING THROUGH VA/NC THIS EVENING AND OVERNIGHT... LIKELY
GENERATING A MORE ORGANIZED BAND OF SHOWERS AND STORMS EXPECTED TO
PIVOT ENE OVER WRN/NRN NC WITH LESSER COVERAGE TO THE SOUTH AND
EAST... WHERE DEEP LAYER SHEAR AND DYNAMIC FORCING FOR ASCENT SHOULD
BE A BIT LOWER. DESPITE THE DECREASE IN LOW LEVEL WARMTH NEAR AND
SOON AFTER SUNSET AS WELL AS THE ANTICIPATED DIP IN THE HIGH MID-
LEVEL LAPSE RATES... THE BETTER KINEMATICS SHOULD HELP BOOST STORM
INTENSITY AND ORGANIZATION. LARGE HAIL REMAINS THE PRIMARY THREAT
AREAWIDE... WITH A SLIGHTLY LOWER RISK OF DAMAGING WINDS. FOLLOWING
THE EXPERIMENTAL HRRR TIMING... WE SHOULD SEE STORMS MOVING OUT OF
THE NE CWA NEAR OR SOON AFTER MIDNIGHT... WITH A CLEARING TREND FROM
SW TO NE LATE. RESIDUAL LOW LEVEL MOISTURE IN THE NE CWA COULD LEAD
TO AREAS OF FOG OR SHALLOW STRATUS BEFORE THE DRIER DEWPOINTS ARRIVE
VERY LATE TONIGHT... HOWEVER CONFIDENCE IN THIS IS LOW. AFTER HIGHS
THIS AFTERNOON FROM AROUND 70 NEAR THE VA BORDER TO THE UPPER
70S/LOWER 80S ELSEWHERE... EXPECT LOWS TONIGHT IN THE MID TO UPPER
50S (NW TO SE). -GIH
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 155 PM MONDAY...
TUESDAY AND TUESDAY NIGHT...MID LEVEL S/W AND ATTENDANT SFC COLD
FRONT WILL EXIT OUR FAR EASTERN COUNTIES PRIOR TO
DAYBREAK...ALLOWING A S/W RIDGE TO CROSS OUR REGION. SUBSIDENCE
ASSOCIATED WITH THIS UPPER FEATURE SHOULD RESULT IN MOSTLY SUNNY-
PARTLY CLOUDY SKIES. AIR MASS BEHIND THE FRONT IS OF PACIFIC ORIGIN
AND WITH DOWNSLOPE COMPONENT OF THE LOW LEVEL FLOW...TEMPERATURES
WILL REMAIN WELL ABOVE NORMAL FOR MID MARCH. HIGH TEMPERATURES
SHOULD VARY FROM THE MID 70S FAR NE WHERE CLOUDS WILL BE LAST TO
DEPART...TO THE LOWER 80S SOUTH. CONTINUED MILD TUESDAY NIGHT WITH
MIN TEMPS 55-60.
WEDNESDAY AND WEDNESDAY NIGHT...S/W RIDGE MOVES EAST EARLY WEDNESDAY
WHILE A DEEP UPPER TROUGH ACROSS THE UPPER MIDWEST/GREAT LAKES
BECOMES NEGATIVELY TILTED. THIS WILL FORCE A SFC COLD FRONT TO SWING
ACROSS CENTRAL NC WEDNESDAY. WESTERLY FLOW PROCEEDING THE FRONT WILL
LIMIT MOISTURE ADVECTION; THUS...EXPECT THE FRONT TO CROSS CENTRAL
NC DRY THOUGH AN ISOLATED SHOWER OR THUNDERSTORM CANNOT BE RULED OUT
IN THE EAST CONSIDERING THE TIME OF DAY THAT THE FRONT IS CROSSING
THE REGION. IF THE FASTER GFS/NAM SOLUTION VERIFIES...850MB TROUGH
EXITS THE REGION BY EARLY AFTERNOON. WHILE LOW LEVEL CAA EXPECTED
BEHIND THIS FEATURE...DOWNSLOPE COMPONENT OF THE FLOW WILL INITIALLY
OFFSET/LIMIT THE COLD AIR. WITH THICKNESSES COMPARABLE TO THE PAST
FEW DAYS...AND LOW LEVEL SW-WESTERLY FLOW FACTORED IN...EXPECT HIGH
TEMPS TO REACH THE 80-85 DEGREE RANGE ACROSS THE REGION. THESE
VALUES ARE JUST A COUPLE OF DEGREES SHY OF THE RECORD HIGH TEMPS FOR
MARCH 16TH. MIN TEMPS WEDNESDAY NIGHT GENERALLY IN THE LOW-MID 50S.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 155 PM MONDAY...
FORECAST CONFIDENCE BEGINS TO WANE THIS PERIOD AS UPPER AIR PATTERN
OVER THE EASTERN U.S. UNDER GOES A CHANGE.
A SERIES OF S/W AND ATTENDANT SFC COLD FRONTS WILL CROSS THE REGION
THU AND FRIDAY. GFS HAS TRENDED WETTER WITH THE LEAD S/W AND SFC
FRONT THOUGH THIS MAY BE OVERDONE CONSIDERING MOISTURE ADVECTION
LIMITED DUE TO WLY FLOW. STILL COULD SEE A BAND OF CLOUDINESS AND
POSSIBLY A SHOWER OR TWO ON THU. NOTICEABLY COOLER AIR WILL
OVERSPREAD THE REGION THURSDAY NIGHT THROUGH EARLY SATURDAY AS A DRY
AIR RIDGE BUILDS/EXTENDS ACROSS THE REGION.
THIS SFC RIDGE WILL DRIFT OFFSHORE LATE SATURDAY WHILE A MID-UPPER
LEVEL TROUGH UNDERGOES AMPLIFICATION OVER THE CENTRAL U.S. S/W
TROUGHS ROTATING THROUGH THE BASE OF THE UPPER TROUGH EXPECTED TO
INDUCE SFC LOW GENERATION OVER THE DEEP SOUTH/NORTHERN GULF COAST
SATURDAY...LIFTING ACROSS THE SE U.S. SATURDAY NIGHT AND SUNDAY.
THIS HAS THE POTENTIAL TO BRING A DECENT ROUND OF RAIN TO THE
CAROLINAS. WILL LIKELY SEE COOLER/SLIGHTLY BELOW NORMAL TEMPS OCCUR
SATURDAY INTO SUNDAY AS SFC PATTERN SIGNALS THE POTENTIAL FOR A
HYBRID OR INSITU DAMMING EVENT. THE UPPER TROUGH EXPECTED TO CROSS
THE CAROLINAS MONDAY...BRINGING AN END TO THE RAIN THREAT.
TEMPS THROUGH THE PERIOD WILL TRENDED DOWNWARD...STARTING OUT IN THE
70S THURSDAY...60S FRIDAY...AND 50S/LOWER 60S SATURDAY/SUNDAY...AND
50S MONDAY. OVERNIGHT TEMPS IN THE 40S EXPECTED WITH 30S POSSIBLE
EARLY NEXT WEEK.
&&
.AVIATION /00Z TUESDAY THROUGH SUNDAY/...
AS OF 730 PM MONDAY...
24-HOUR TAF PERIOD: AS AN UPPER LEVEL DISTURBANCE MOVES OVER THE
REGION...SCATTERED TO NUMEROUS THUNDERSTORMS WILL CONTINUE...SOME
RESULTING IN DAMAGING WIND GUSTS AND HAIL. CURRENT STORMS LOOK TO
MOST IMMEDIATELY IMPACT KRDU AND EVENTUALLY KRWI...HOWEVER THE
ADDITIONAL STORMS COMING INTO CENTRAL NC WILL PARTICULARLY AFFECT
KINT/KGSO WITH A SLIGHTLY LOWER THREAT AT FAY. THIS SECOND ROUND OF
STORMS SHOULD SHIFT EASTWARD ACROSS CENTRAL NC THIS EVENING...
EXITING OUR NORTHEAST BY APPROXIMATELY 06Z. SKIES ARE EXPECTED TO
CLEAR OUT FROM SW TO NE LATE TONIGHT THROUGH TUE MORNING (FROM 08Z
TO 16Z)...ALTHOUGH A BRIEF PERIOD OF LOW-END VFR TO MVFR CIGS/VISBYS
ARE POSSIBLE BETWEEN 06Z AND 12Z...PARTICULARLY WHERE RAIN HAS
FALLEN. SURFACE WINDS MAY CONTINUE TO BE VARIABLE ACROSS THE
NORTHERN PORTIONS OF THE AREA WITH THE FRONT LINGERING...HOWEVER
THEY SHOULD BECOME MAINLY WNW OR NW OVERNIGHT AND INTO THE DAY
TUESDAY. OTHERWISE...VFR CONDITIONS ARE EXPECTED THROUGH THE
REMAINDER OF THE TAF PERIOD. -KC
LOOKING AHEAD: VFR CONDITIONS ARE LIKELY TO HOLD THROUGH SAT. THERE
IS A SMALL CHANCE OF SHOWERS ALONG THE STALLED FRONT LATE WED NIGHT
THROUGH THU AS A WAVE OF LOW PRESSURE TRACKS ALONG THE FRONT THROUGH
OUR AREA... BUT ANY SUB-VFR CONDITIONS ASSOCIATED WITH THIS WOULD BE
BRIEF. -GIH
&&
.CLIMATE...
HERE ARE THE RECORD HIGH TEMPERATURES FOR MARCH 16TH.
RDU 86/1945
GSO 85/1945
FAY 87/1945
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...WSS
LONG TERM...WSS
AVIATION...KC/GIH
CLIMATE...RAH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
918 PM CDT MON MAR 14 2016
.UPDATE...
ISSUED AT 918 PM CDT MON MAR 14 2016
THIS UPDATE FOCUSED ON REFINING POPS FOR THE SHOWERS AND ISOLATED
THUNDERSTORMS THAT ARE OCCURRING ALONG AND AHEAD OF THE COLD FRONT
THAT IS JUST EAST OF THE HIGHWAY 83 CORRIDOR AS OF 02 UTC. WE USED
TIME-LAGGED HRRR GUIDANCE TO ADJUST POPS OVERNIGHT SINCE IT PICKS
UP ON RADAR TRENDS AS OF MID EVENING...WITH DRYING OVER WESTERN ND
IN THE POST-FRONTAL AIR MASS SPREADING EAST OVERNIGHT. THE 00 UTC
ABERDEEN SOUNDING SAMPLED A MODERATELY UNSTABLE AIR MASS WHICH THE
RAP-BASED SPC MESOANALYSIS SUGGESTS EXTENDS INTO EAST CENTRAL ND
WHERE SURFACE DEWPOINTS ARE BETWEEN 45 AND 50 F THIS EVENING...BUT
IT APPEARS EFFECTIVE SHEAR LESS THAN 30 KT IS LIMITING THE CHANCE
OF SUSTAINED STRONG UPDRAFTS.
UPDATE ISSUED AT 604 PM CDT MON MAR 14 2016
WE INCREASED POST-FRONTAL NORTHWEST WIND SPEEDS OVER WESTERN AND
PARTS OF CENTRAL ND THIS EVENING WITH THIS UPDATE GIVEN UPSTREAM
PRESSURE RISES...OTHERWISE ONLY MINOR CHANGES WERE MADE.
AS OF 23 UTC...CONVECTION IS DEVELOPING OVER CENTRAL ND WITH A
WELL-DEFINED THUNDERSTORM SOUTHWEST OF MINOT...AND RECENT VISIBLE
SATELLITE IMAGERY SHOWS AGITATED CUMULUS FURTHER SOUTHWARD ACROSS
PARTS OF BURLEIGH AND EMMONS COUNTIES AS WELL. LOW-LEVEL MOISTURE
ACTUALLY MIXED OUT WITH LOWERING DEWPOINTS ALONG THE HIGHWAY 83
CORRIDOR LATE THIS AFTERNOON...REDUCING INSTABILITY...BUT STEEP
MID-LEVEL LAPSE RATES ARE STILL SUFFICIENT FOR CONVECTIVE GROWTH.
RAP-BASED MESOANALYSIS OUTPUT SUGGESTS GREATER MLCAPE UP TO AROUND
1000 J/KG IS POSSIBLE EAST OF HIGHWAY 83 AND SOUTH OF HIGHWAY 2
THIS EVENING IF SURFACE DEWPOINTS OVER 45 F ARE MAINTAINED AHEAD
OF THE DEVELOPING CONVECTION...SUGGESTING A STRONG STORM OR TWO
COULD OCCUR.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 341 PM CDT MON MAR 14 2016
CURRENT SURFACE ANALYSIS PLACES LOW OVER SOUTHERN MANITOBA WITH
COLD FRONT DROPPING DOWN NEAR THE MONTANA/NORTH DAKOTA BORDER.
UPPER LEVEL ANALYSIS PLACES TROUGH OVER THE ROCKIES WITH RIDGE
OVER THE UPPER MIDWEST STRETCHING TOWARDS THE
SASKATCHEWAN/MANITOBA BORDER. SHORTWAVE WORKING TOWARDS THE
NORTHERN PLAINS CONTINUES TO PRODUCE PRECIPITATION OVER EASTERN
MONTANA...WHILE A LOW IS STARTING TO CLOSE OFF OVER FAR
SOUTHEASTERN ALBERTA.
FOR THE REST OF THIS AFTERNOON INTO TONIGHT...AFOREMENTIONED
CLOSING OFF SURFACE LOW WILL SHIFT OVER SOUTHERN SASKATCHEWAN
OVERNIGHT WHILE COLD FRONT/SURFACE LOW PUSH OVER NORTH DAKOTA.
THIS WILL BRING A BROAD SWATH OF RAIN SHOWERS OVER THE AREA. AHEAD
OF THE SURFACE LOW/COLD FRONT MOISTURE/INSTABILITY WILL BE ON THE
INCREASE WITH SOUTH/SOUTHEASTERLY LOW LEVEL FLOW...SO A FEW
AFTERNOON/EVENING THUNDERSTORMS WILL NOT BE OUT OF THE QUESTION.
ON TUESDAY...SOME SHOWERS MAY LINGER OVER THE EAST FOR A BIT IN
THE MORNING...OTHERWISE THE DAY SHOULD START OUT QUIET. WINDS WILL
BE ON THE INCREASE THROUGH THE MORNING IN THE WAKE OF THE
DEPARTING SURFACE LOW/COLD FRONT. MODEST COOL AIR ADVECTION BEHIND
THE DEPARTING SYSTEM WILL BRING NOTABLY COOLER CONDITIONS...WITH
HIGHS AROUND 50. UPPER LOW OVER SASKATCHEWAN GRADUALLY MOVES TO
THE EAST/SOUTHEAST WITH THE NEXT SHORT WAVE SWINGING AROUND INTO
THE AREA IN THE AFTERNOON...BRINGING CHANCES FOR SHOWERS TO THE
FAR WEST.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 341 PM CDT MON MAR 14 2016
MUCH COOLER TEMPERATURES AND MORE ACTIVE WEATHER IS THE MAIN
HIGHLIGHTS FOR THE LONG TERM FORECAST PERIOD.
MODELS REMAIN IN VERY GOOD AGREEMENT WITH A NEGATIVELY TILTED
UPPER LEVEL TROUGH FORMING OVER THE NORTHERN PLAINS AND STALLING
OVER THE REGION INTO EARLY WEDNESDAY. WRAP AROUND MOISTURE AND
CAA MOVING NORTH TO SOUTH TUESDAY NIGHT AND ONWARDS AS A CUTOFF
LOW FORMS AND SLOWLY PIVOTS SOUTHWARD THROUGH THE REGION.
PROLONGED PERIOD OF PRECIPITATION IS BEING ADVERTISED BY MOST
MODELS AS A TROWAL/DEFORMATION ZONE SETS UP...INITIALLY AS A
RAIN/SNOW MIX THEN ALL SNOW AS COLDER AIR PUSHES ACROSS THE STATE.
STILL A DECENT AMOUNT OF UNCERTAINTY ALTHOUGH CHANCE TO LIKELY
POPS REMAIN WARRANTED.
SOME AREAS WILL SEE 1 TO 4 INCHES OF SNOW POSSIBLE THROUGH FRIDAY
WHILE OTHER LOCATIONS LESS. STILL SOME UNCERTAINTY AS THERE IS
STILL MID/UPPER LEVEL ENERGY YET TO MOVE ONSHORE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 918 PM CDT MON MAR 14 2016
A COLD FRONT THAT IS JUST EAST OF A KMOT TO KBIS AND KMBG LINE AT
02 UTC WILL CONTINUE MOVING EAST OVERNIGHT. SHOWERS AND ISOLATED
THUNDERSTORMS WITH POSSIBLE BRIEF MVFR CONDITIONS AND GUSTY AND
ERRATIC SURFACE WINDS ARE POSSIBLE AHEAD OF THE FRONT...INCLUDING
AT KJMS THROUGH ABOUT 08 UTC. OTHERWISE...WE EXPECT VFR CONDITIONS
TO PREVAIL TONIGHT AND ON TUESDAY WHEN DRYING NORTHWEST WIND GUSTS
TO 30 KT ARE EXPECTED ACROSS MUCH OF WESTERN AND CENTRAL ND.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...CJS
SHORT TERM...JJS
LONG TERM...NH
AVIATION...CJS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
946 AM CDT SUN MAR 13 2016
.UPDATE...
ISSUED AT 946 AM CDT SUN MAR 13 2016
MAIN IMPACT FOR TODAY APPEARS TO BE DENSE FOG WHICH HAS DEVELOPED
ACROSS NORTH EAST NORTH DAKOTA. MOISTURE ADVECTION WILL CONTINUE
INTO THIS AREA ALONG AND AHEAD OF THE SURFACE TROUGH (LOCATED
ACROSS CENTRAL NORTH DAKOTA THIS MORNING). HRRR AND RAP GUIDANCE
SUGGEST THAT TEMPS WILL RISE A BIT BY NOON AND DENSE FOG WILL
IMPROVE...WITH RAPID IMPROVEMENT AS WIND SHIFTS MOVES THROUGH THE
AREA. ISSUED A SPS TO INCREASE AWARENESS OF THE SITUATION...BUT
HELD OFF ON A DENSE FOG ADVISORY CONSIDERING THE EXPECTED SHORTER
NATURE. THERE IS A WORRY THAT MOISTURE ADVECTION WILL OFFSET ANY
TEMPERATURE RISE AND CONTINUE DENSE FOG AHEAD OF THE SFC
TROUGH...WHICH DOES NOT MOVE INTO THIS REGION UNTIL MID-LATE
AFTERNOON. IF CONDITIONS DO NOT START IMPROVING BY 11AM MAY NEED
TO CONSIDER A DENSE FOG ADVISORY.
RAIN SHOWERS MOST LIKELY EAST OF THE VALLEY...ALTHOUGH COVERAGE
LIKELY LIMITED. MOST AREAS ACROSS THE REGION WILL LIKELY
EXPERIENCE DRIZZLE AND LOW CLOUDS THROUGH THE DAY.
UPDATE ISSUED AT 648 AM CDT SUN MAR 13 2016
MADE A FEW MINOR TWEAKS TO POPS AS RAIN HAS STARTED TO MOVE INTO
THE SOUTHEASTERN CWA...BUT THE MAIN CHANGE WAS TO ADD SOME PATCHY
FOG. SOME LOWERED VIS FROM THE SHEYENNE VALLEY UP TOWARDS
KDVL...AND EVEN EAST TOWARDS THE RED RIVER VALLEY. SREF
PROBABILITIES OF LOWER VISIBILITY HANDLE THIS PRETTY WELL SO
FOLLOWED THE TREND OF FOG IN THAT AREA THROUGH ABOUT 15Z. MODELS
HAVE BEEN TRENDING MOSTLY EAST WITH THE QPF...BUT THERE ARE SOME
LIGHT RADAR RETURNS IN THE RED RIVER VALLEY SO CANNOT COMPLETELY
RULE OUT SOME DRIZZLE. THUS KEPT POPS GOING.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 332 AM CDT SUN MAR 13 2016
HOW FAR WEST RAIN WILL GO TONIGHT AND TOMORROW WILL BE THE MAIN
FORECAST ISSUE FOR THE PERIOD.
MAIN UPPER TROUGH IS STILL WELL TO THE SOUTH...BUT WV LOOP AND
MODEL ANALYSIS HAS A DECENT SHORTWAVE TROUGH LIFTING THROUGH
EASTERN SD. RAIN HAS ALREADY STARTED AT ELBOW LAKE...AND SHOULD
CONTINUE TO MOVE NORTHWARD DURING THE EARLY MORNING HOURS. ANOTHER
WEAK SHORTWAVE WILL COME IN FROM THE WEST LATER TODAY AS
SOUTHWESTERLY FLOW ALOFT SETS UP AHEAD OF THE NORTHERN BRANCH
UPPER TROUGH. THE SHORT RANGE MODELS HAVE THE PRECIP STAYING IN
OUR FAR EASTERN TIER...BUT THE GLOBAL RUNS ARE A BIT FURTHER WEST
OVER THE RED RIVER VALLEY...PARTICULARLY THE GFS. COMPROMISED AND
KEPT HIGHEST POPS AND QPF IN THE EAST BUT HAVE THE MENTION OF
SHOWERS GOING TOWARDS THE RED RIVER VALLEY...WHICH GIVEN CURRENT
RADAR TRENDS SEEMS REASONABLE. THE RAIN AND CLOUDS WILL KEEP TEMPS
LOWER THAN THE PAST FEW DAYS...WITH THE EAST STAYING IN THE LOW
50S EVEN WITH A VERY MILD START BUT SOME LOW 60S POSSIBLE IN THE
WEST.
THE PRECIP WILL HEAD OFF TO THE EAST TONIGHT AS THE WEAK SHORTWAVE
MOVES OUT OF THE AREA. THE SFC TROUGH THAT MOVED IN DURING THE DAY
WILL BEGIN TO WASH OUT AS ANOTHER TROUGH REFORMS OVER THE NORTHERN
ROCKIES. ONLY A SLIGHT DECREASE IN DEW POINTS AND THERE WILL BE
LINGERING CLOUDS SO KEPT LOWS PRETTY MILD. A FEW OF THE MODELS
BRING ANOTHER WEAK LEAD SHORTWAVE OUT DURING THE DAY ON
MONDAY...WITH THE NAM IN PARTICULAR BREAKING OUT SOME PRECIP OVER
OUR NORTHWESTERN COUNTIES. IT SEEMS TO BE AN OUTLIER...BUT GIVEN
ANY WEAK SHORTWAVE MOVING THROUGH THE SOUTHWEST FLOW COULD SET
SOMETHING OFF AND TO BLEND WITH NEIGHBORS INCLUDED SOME LOW POPS
IN OUR NORTHWEST. HIGHS WILL AGAIN BE VERY WARM IN THE UPPER 50S
TO 60S WITH SOUTHERLY LOW LEVEL FLOW.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 332 AM CDT SUN MAR 13 2016
MONDAY NIGHT THROUGH TUESDAY NIGHT...THE NORTHERN STREAM WILL
BECOME MORE ACTIVE AS A LARGE CUT OFF UPPER LOW WOBBLES INTO THE
NORTHERN PLAINS DURING THE PERIOD. THERE IS A LOT OF VARIATION IN
EXACTLY HOW THE MODELS HANDLE THIS SYSTEM. THE GFS IS FASTER
BRINGING IN THE INITIAL WARM AIR PRECIP MONDAY NIGHT BUT THEN DRY
SLOTS US LATER WHILE THE ECMWF HAS THE ELONGATED SFC TROUGH
LINGERING OVER THE AREA. THE NAM TRACKS MUCH FURTHER SOUTH WITH
THE SFC LOW...BRINGING US RIGHT IN THE DEFORMATION ZONE AND
PRODUCING A LOT MORE SNOW WITH THE COLDER AIR BEHIND IT. WITH THE
HIGH LEVEL OF UNCERTAINTY WILL LEAN TOWARDS A GFS AND ECMWF BLEND
WHICH WOULD HAVE A BETTER HANDLE ON THIS PERIOD THAN THE LIMITED
AREA NAM. SOME SNOW MAY MIX IN LATE TUESDAY NIGHT BUT AT THIS
POINT WILL HAVE MOSTLY RAIN. THE CLOUDS AND PRECIP SHOULD KEEP
LOWS MILD BUT HIGHS ON TUESDAY WILL BE NOT AS WARM AS PREVIOUS
DAYS...ONLY IN THE 40S AND LOW 50S BUT STILL ABOVE SEASONAL
AVERAGES.
WEDNESDAY THROUGH FRIDAY...UPPER LOW WILL LIKELY BE ELONGATED
EAST TO WEST FROM UPPER MIDWEST THROUGH NORTHERN GREAT LAKES TO
START THE PERIOD...WITH EARLIER STEADY PCPN BECOMING MORE
INTERMITTENT WED/THU. AIRMASS SHOULD BE WARM ENOUGH TO PROVIDE
MOSTLY RAIN...ESPECIALLY DURING DAYLIGHT HOURS AND OVER THE
SOUTHERN HALF OF THE FORECAST AREA. A MIX OF SNOW WOULD BE MORE
LIKELY BY WED NIGHT/THU. A BREAK IN PCPN IS LIKELY BY FRI WITH
INDICATION OF THE NEXT WAVE INCREASING CHANCES AGAIN ON SATURDAY.
TEMPS WILL DIP BELOW FREEZING WED NIGHT AND SUBSEQUENT NIGHTS...WITH
DAYTIME HIGHS EASING BACK TO NEAR AVERAGE SEASONAL VALUES THU AND
FRI.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 648 AM CDT SUN MAR 13 2016
LOW STRATUS AND SOME FOG HAS ENTERED THE FORECAST AREA FROM THE
SOUTH...WITH IFR OR LOWER CONDITIONS AT ALL BUT KTVF WHICH IS MVFR
AND KBJI WHICH IS VFR. THE BETTER CONDITIONS AT THE EASTERN TAF
SITES WILL NOT LAST LONG AS MOISTURE CONTINUES TO POUR IN FROM THE
SOUTH AND RAINFALL OR SHOWERS WILL IMPACT THOSE SITES LATER IN THE
MORNING. LOWERED VIS AT THE WESTERN TAF SITES SHOULD IMPROVE
SOMEWHAT...AND KDVL COULD GO VFR FOR A TIME LATER THIS AFTERNOON.
OTHERWISE STRATUS SHOULD BE HANGING AROUND THROUGHOUT THE PERIOD
FROM THE RED RIVER VALLEY EASTWARD...AND THERE IS THE POSSIBILITY
OF FOG REFORMING AGAIN LATER TONIGHT AT KTVF AND KBJI. SOUTHEAST
WINDS AROUND 12 KTS WILL BECOME LIGHT AND VARIABLE BY THE END OF
THE PERIOD.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...TG
SHORT TERM...JR
LONG TERM...JR/WJB
AVIATION...JR
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
720 PM EDT MON MAR 14 2016
.SYNOPSIS...
AN UPPER AIR DISTURBANCE CROSSING INTO THIS EVENING. COLD FRONT
EARLY WEDNESDAY MORNING. DRIER AIR/LOWERING DEW POINTS WEDNESDAY
AFTERNOON. WEAK MID LEVEL DISTURBANCE THURSDAY.
&&
.NEAR TERM /THROUGH TUESDAY/...
CONVECTION DEVELOPING TO OUR WEST...ASSOCIATED WITH UPPER LEVEL
SHORTWAVE TROUGH/VORT LOBE OVER CENTRAL KY. MODELS SHOW THIS
FEATURE GRADUALLY LOSING STEAM AS IT CROSSES LATER THIS AFTERNOON
INTO TONIGHT. HAVE SOME UNSTABLE AIR IN PLACE ACROSS THE CWA THIS
AFTERNOON. CAPE LOOKS TO MAX OUT AT AROUND 1000 J/KG...BUT IS A
FAIRLY SKINNY PROFILE. HOWEVER...COMBINE THAT WITH A FREEZING
LEVEL AROUND 9000FT AGL...SOME SMALL HAIL WOULD BE POSSIBLE IN
ANY TALLER STORMS. FLOW IS NOT OVERLY STRONG... 35-40KTS AT 700MB
AND 500MB... BUT WE DO HAVE A WEAK INVERTED V AND POCKET OF DRIER
AIR IN THE MID LEVELS PER FORECAST SOUNDINGS. THIS COULD LEAD TO
ISOLATED DAMAGING WIND GUSTS IN THE STRONGER CELLS. BULK SHEAR IS
ONLY MARGINAL -- AROUND 35KTS -- SO EXPECT INDIVIDUAL CELLS TO BE
RATHER UNORGANIZED AND MAYBE PULSE-Y IN NATURE.
WITH ALL THAT IN MIND...HAVE AN AREA OF HIGH POPS TRANSITIONING
ACROSS CWA FROM SW TO NE THIS AFTERNOON AND EVENING. RELIED FAIRLY
HEAVILY ON THE HI-RES NAM AND HRRR FOR TIMING OF THE HIGHEST POPS.
PRECIPITABLE WATER SHOULD BE 1-1.2 IN...WHICH SHOULD NOT CREATE
ANY WIDESPREAD PROBLEMS. HAVE ONGOING FLOOD WATCH ACROSS THE
NORTH. WITH MIDDLE ISLAND CREEK AND DUCK CREEK CONTINUING TO RUN
HIGH...AND A BULLSEYE OF LOW FLASH FLOOD GUIDANCE...WILL LEAVE THE
FLOOD WATCH AS IS. PRECIP WILL BE COMING TO AN END FROM WEST TO
EAST TONIGHT...HOWEVER WITH NO COLD FRONT PUSHING THROUGH THE LOW
LEVEL MOISTURE REMAINS IN PLACE WHICH SHOULD LEAD TO LOW STRATUS
AND SOME VALLEY FOG BY EARLY TUESDAY MORNING.
USED A BLEND OF CONSENSUS GUIDANCE AND ECMWF MOS FOR HIGHS WHICH
DID NOT RESULT IN ANY REAL SIGNIFICANT CHANGES. A MAV/MET BLEND
FOR LOWS TONIGHT TRENDED A TOUCH WARMER THAN PREVIOUS FORECAST.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
MID LEVEL DYNAMICS IN THE MIDWEST...IOWA AND ILLINOIS...NEAR 00Z
WEDNESDAY LIFTS NORTHEAST TOWARD MICHIGAN BY 06Z AND AND EASTERN
GREAT LAKES BY 12Z WED. MEANWHILE 500 MB HEIGHTS ONLY FALL SLOWLY
HERE.
SO NOT IMPRESSED WITH SUPPORT AHEAD OF THE SURFACE FRONT. STILL
HAVE FRONT SWEEPING EAST. FIGURING REACHING TOWARD CRW AROUND 12Z
WEDNESDAY...THEN EXITING MOUNTAINS BY 15Z. DESPITE LACK OF
MID LEVEL SUPPORT...CONSIDERING AIR MASS WE ARE STILL IN...AHEAD
OF THE FRONT...WILL STILL LEAVE SOME 20 TO 40 POPS ASSOCIATED WITH
THE FRONT.
WESTERLY FLOW OF LOWERING DEW POINTS AND FRESHER AIR ADVECTING OUR
WAY...DURING THE DAY ON WEDNESDAY.
MID LEVEL DISTURBANCE IN FAST FLOW SOUTH OF THE CLOSED 500 MB LOW
OVER THE WESTERN GREAT LAKES FOR WEDNESDAY NIGHT INTO THURSDAY.
HAVE MID LEVEL MOISTURE INCREASING OVERNIGHT WEDNESDAY NIGHT. COULD
NOT RULE OUT SOME LIGHT RAIN LATE WEDNESDAY NIGHT INTO THURSDAY...BUT
AGAIN COULD NOT GO MORE THAN 20 TO 40 POPS.
CONSIDERING 850 TEMPERATURES ONLY AROUND PLUS 1 C...LOWERED MAXIMUM
TEMPERATURES AND EVEN MENTIONED A POSSIBILITY FOR THOSE POPS OF R-S-
AOA 4000 FEET.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
GENERALLY QUIET WX WILL GREET FOLKS ENDING THE WORK WEEK WITH
SEASONAL TEMPS. WE STILL ENVISION A PATTERN CHANGE HEADING INTO THE
WEEKEND WHICH WILL ESTABLISH A MEAN EASTERN US TROF THRU EARLY NEXT
WEEK. GLOBAL MODELS CONTINUE TO STRUGGLE WITH THE EVOLUTION OF THIS
AND MORE SPECIFICALLY IF A CONSOLIDATED LOW PRESSURE SYSTEM WILL
FORM ON SUNDAY. REGARDLESS...EXPECT SOME CHILLY RAIN SHOWERS WITH
MOUNTAIN SNOW SHOWERS ON SUNDAY.
&&
.AVIATION /23Z MONDAY THROUGH SATURDAY/...
SHORT WAVE TROUGH MOVES ACROSS THE AREA TONIGHT. NUMEROUS SHOWERS
AND ISOLATED STORMS ARE POSSIBLE THROUGH MIDNIGHT.
EXPECT MOSTLY MVFR CONDITIONS UNDER RAIN SHOWERS OR STORMS WITH
GUSTY WINDS AROUND 30 KNOTS WITH THE HEAVIER STORMS THROUGH AT
LEAST 10 PM AT EKN AND CKB. OTHERWISE...MVFR CONDITIONS SHOULD
PREVAIL FOR MOST OF THE NIGHT THROUGH EARLY TUESDAY MORNING. RADAR
IMAGES SHOW AN AREA OF STRATIFORM RAIN BEHIND THE LEADING EDGE OF
CONVECTION. SO...PCPN IS LIKELY TO CONTINUE THROUGH AT LEAST
MIDNIGHT.
LOW LEVEL MOISTURE LINGERS THROUGH THE NIGHT. SATELLITE IMAGES
SHOW THE CIRCULATION IN THE INFRARED CHANNEL MOVING TOWARDS WV. IT
IS POSSIBLE THAT ONCE THE SHORTWAVE MOVES EAST...BREAKS IN THE SKY
COULD ALLOW FOR RADIATIONAL COOLING AND ASSOCIATED FOG OR LOW
STRATUS. DUE TO ANTECEDENT PCPN AND HIGH RH...CODED IFR FOG AT
EKN...HTS AND CRW DEVELOPING OVERNIGHT.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z WEDNESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING AND DENSITY OF FOG OR LOW STRATUS MAY
VARY OVERNIGHT.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 22 23 00 01 02 03 04 05 06 07 08 09
EDT 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
CRW CONSISTENCY M M M M M H H H H M M M
HTS CONSISTENCY M M H H H H H M M M M M
BKW CONSISTENCY M M M M M M M M M M M M
EKN CONSISTENCY H H H M M M M M M M L L
PKB CONSISTENCY M M M M M M H H H M M M
CKB CONSISTENCY H H M M M M M M M M M M
AFTER 00Z WEDNESDAY...
BRIEF IFR CIGS POSSIBLE IN MOUNTAINOUS COUNTIES EARLY WEDNESDAY
MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FLOOD WATCH UNTIL 6 AM EDT TUESDAY FOR WVZ009>011-017-019-020-
031-032-040.
OH...FLOOD WATCH UNTIL 6 AM EDT TUESDAY FOR OHZ066-067-075-076-084.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...MZ/30/26
NEAR TERM...MZ
SHORT TERM...KTB
LONG TERM...30
AVIATION...ARJ
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
131 PM EDT SUN MAR 13 2016
.SYNOPSIS...
A WARM FRONT EXTENDING FROM MISSOURI EAST TO THE OHIO VALLEY WILL
REACH CENTRAL OHIO THIS AFTERNOON AND LIFT NORTH OF LAKE ERIE
TONIGHT. A SECOND AREA OF LOW PRESSURE WILL MOVE NORTH ACROSS OHIO
ON MONDAY AND MONDAY NIGHT. ANOTHER AREA OF LOW PRESSURE MOVING OUT
OF THE PLAINS WILL SLOWLY MOVE EAST ACROSS THE GREAT LAKES REGION
THROUGH THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
BASED ON LATEST RADAR...HRRR
AND RAP WILL MAKE SOME MINOR ADJUSTMENTS TO POP FIELDS TO REFLECT
BANDS OF SHRA. WIDESPREAD RAIN ACROSS CENTRAL OHIO WILL CONTINUE TO
MOVE NORTH. SOUTHERN AREAS SHOULD START TO SEE SOME BREAKS IN THE
STEADY RAIN BY MIDDAY...ALTHOUGH OCCASIONAL SHOWERS WITH A SLIGHT
CHANCE OF THUNDERSTORMS WILL CONTINUE THROUGH THE AFTERNOON. THE
CLOUDS AND RAIN WILL LIKELY KEEP THINGS A LITTLE COOLER.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
SHOWERS WILL CONTINUE THROUGH THE EVENING THEN START TO TAPER OFF
FROM SOUTH TO NORTH AFTER MIDNIGHT. MOST AREAS WILL SEE A BREAK IN
THE ACTIVITY CONTINUING INTO MONDAY MORNING BEFORE THE NEXT
SHORTWAVE TROUGH KICKS OFF MORE SHOWERS IN THE MONDAY
AFTERNOON/TUESDAY TIME FRAME. POPS ARE IN THE 60-70 PERCENT RANGE
AGAIN ON MONDAY WITH SLIGHTLY BETTER CHANCES OF THUNDERSTORMS WITH
SOME SURFACE BASED INSTABILITY DEVELOPING ACROSS MAINLY CENTRAL AND
EASTERN OHIO. ALL AREAS SHOULD BE IN THE WARM SECTOR WITH HIGHS IN
THE MID 60S EXCEPT UPPER 50S NW PA. QPF FORECAST THROUGH MONDAY
NIGHT CONTINUES TO BE NEAR 1 INCH FOR MOST AREAS. LOCALLY HIGHER
RAINFALL IS EXPECTED WHERE THUNDERSTORMS DEVELOP. THE RAINFALL IS
STILL EXPECTED TO CAUSE RISES ON AREA RIVERS WITH ONLY A COUPLE
APPROACHING MINOR FLOOD STAGE...OTHERWISE NOT EXPECTING A LOT OF
FLOODING PROBLEMS.
SHORTWAVE RIDGING BUILDS ALOFT ON TUESDAY WITH TEMPERATURES RUNNING
AROUND 20 DEGREES ABOVE NORMAL FOR MID MARCH. THE NEXT SYSTEM TO
WATCH IN THIS ACTIVE PATTERN WILL DEVELOP OVER THE PLAINS ON TUESDAY
AS A STRONG PACIFIC JET RACES EASTWARD. AN ELONGATED SURFACE TROUGH
EXTENDING FROM THE NORTHERN PLAINS TO THE THE MISSOURI VALLEY WILL
CURL NORTHEAST TOWARDS THE WESTERN LAKES REGION TUESDAY NIGHT.
TRENDED TEMPERATURES UP ON TUESDAY NIGHT AND SUSPECT THEY WILL BE
RATHER WARM IN THE EAST AHEAD OF THE COLD FRONT. SCATTERED SHOWERS
WILL ALSO ACCOMPANY THE FRONT WITH BEST CHANCES FOR MORE
PRECIPITATION FOCUSED ACROSS THE WEST AND NORTH. VERY DRY AIR WRAPS
IN ON THE SOUTH SIDE OF THIS SYSTEM ON WEDNESDAY WITH GOOD
MIXING AND BREEZY CONDITIONS EXPECTED.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
PLENTY OF UNCERTAINTY BETWEEN THE MODELS AS THEY STRUGGLE WITH HOW
TO HANDLE THE WEAKENING AREA OF LOW PRESSURE OVER THE GREAT LAKES
REGION THURSDAY INTO FRIDAY. CURRENT THINKING IS THAT SCATTERED
SHOWERS WILL BE POSSIBLE ACROSS THE REGION ON THURSDAY WITH THE
COVERAGE DECREASING INTO FRIDAY. THERE IS NO CONSISTENCY IN THE
MODELS FOR SATURDAY WHICH LEADS TO LITTLE FORECAST CONFIDENCE. THERE
IS A 24 HOUR TIMING DIFFERENCE WITH THE APPROACH OF THE NEXT AREA OF
LOW PRESSURE THAT EMERGES FROM THE SOUTHERN PLAINS.
IT APPEARS THAT THE REGION WILL BE WARM ENOUGH TO KEEP ALL
PRECIPITATION IN THE FORM OF RAIN. HIGHS THROUGH THE LONG TERM WILL
BE AROUND SEASONAL AVERAGES.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
CIGS AND VSBYS HAVE BEEN SLOW TO DROP TODAY WITH MOST AREAS STILL
VFR. SCATTERED SHOWERS REMAIN ON THE RADAR AND WILL CONTINUE THE
FIRST HALF OF THE TAF PERIOD. IFR CIGS ARE JUST SW OF THE AREA AND
SHOULD BEGIN TO MOVE IN THIS AFTERNOON AS THE SURFACE LOW OVER IL
HEADS NE. THE GUIDANCE CONTINUES TO SHOW A 6 TO 9 HOUR WINDOW OF
IFR CIGS AND WILL GO WITH THAT PREMISE EXCEPT AT KERI AND KCLE
WHERE DOWNSLOPING FLOW WILL KEEPS CIGS A TAD HIGHER. WILL TRY TO
END THE PRECIP FROM S TO N LATER THIS EVENING AND EXPECTING MAINLY
DRY WEATHER AND MVFR CIGS OVERNIGHT. E FLOW WILL BECOME SE BY 00Z
AND THEN SOUTH OVERNIGHT. SE WINDS AT KERI COULD GET GUSTY FOR A
FEW HOURS TONIGHT GIVEN THE DOWNSLOPE. GIVEN WHAT HAS HAPPENED SO
FAR TODAY CONFIDENCE IS FAIRLY LOW AS FAR AS THE TIMING OF THE IFR
CIGS GO.
OUTLOOK...NON VFR CONDITIONS WILL CONTINUE AT TIMES MONDAY INTO
MONDAY NIGHT. NON VFR POSSIBLE AGAIN TUESDAY NIGHT.
&&
.MARINE...
NORTHEAST TO EAST WINDS WILL INCREASE TODAY AS A WEAK AREA OF LOW
PRESSURE MOVES INTO CENTRAL INDIANA THIS AFTERNOON. WINDS WILL
INCREASE TO 15 TO 20 KNOTS FOR LATE AFTERNOON INTO THE EVENING
ACROSS THE WESTERN HALF OF THE LAKE. WINDS OF THIS SPEED COMBINED
WITH A LONGER FETCH MAY BUILD WAVES CLOSE TO THE 4 FOOT THRESHOLD
FOR SMALL CRAFT CONDITIONS. FOR NOW HAVE HELD OFF ON A SMALL CRAFT
ADVISORY AND LET LATER SHIFTS MONITOR THIS POTENTIAL. WINDS WILL
DECREASE INTO MONDAY MORNING AS THEY SHIFT TO THE SOUTH. THE
GRADIENT WILL LIKELY BE LIGHT ENOUGH MONDAY AND TUESDAY FOR THE
DEVELOPMENT OF A LAKE BOUNDARY. THE LAKE BREEZE POTENTIAL LOOKS
GREATEST ON TUESDAY FROM CLEVELAND TO ERIE. SO EXPECT TO SEE ONSHORE
FLOW IN THIS REGION ON TUESDAY. BY TUESDAY NIGHT WINDS WILL BECOME
WEST TO SOUTHWEST AND THEN REMAIN THAT WAY INTO THURSDAY. SPEEDS OF
10 TO 20 KNOTS WILL BE COMMON.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KEC
NEAR TERM...KEC
SHORT TERM...KEC
LONG TERM...MULLEN
AVIATION...KUBINA
MARINE...MULLEN
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
905 AM EDT SUN MAR 13 2016
.SYNOPSIS...
A WARM FRONT EXTENDING FROM MISSOURI EAST TO THE OHIO VALLEY WILL
REACH CENTRAL OHIO THIS AFTERNOON AND LIFT NORTH OF LAKE ERIE
TONIGHT. A SECOND AREA OF LOW PRESSURE WILL MOVE NORTH ACROSS OHIO
ON MONDAY AND MONDAY NIGHT. ANOTHER AREA OF LOW PRESSURE MOVING OUT
OF THE PLAINS WILL SLOWLY MOVE EAST ACROSS THE GREAT LAKES REGION
THROUGH THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/... BASED ON LATEST RADAR...HRRR
AND RAP WILL MAKE SOME MINOR ADJUSTMENTS TO POP FIELDS TO REFLECT
BANDS OF SHRA. WIDESPREAD RAIN ACROSS CENTRAL OHIO WILL CONTINUE TO
MOVE NORTH. SOUTHERN AREAS SHOULD START TO SEE SOME BREAKS IN THE
STEADY RAIN BY MIDDAY...ALTHOUGH OCCASIONAL SHOWERS WITH A SLIGHT
CHANCE OF THUNDERSTORMS WILL CONTINUE THROUGH THE AFTERNOON. THE
CLOUDS AND RAIN WILL LIKELY KEEP THINGS A LITTLE COOLER.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
SHOWERS WILL CONTINUE THROUGH THE EVENING THEN START TO TAPER OFF
FROM SOUTH TO NORTH AFTER MIDNIGHT. MOST AREAS WILL SEE A BREAK IN
THE ACTIVITY CONTINUING INTO MONDAY MORNING BEFORE THE NEXT
SHORTWAVE TROUGH KICKS OFF MORE SHOWERS IN THE MONDAY
AFTERNOON/TUESDAY TIME FRAME. POPS ARE IN THE 60-70 PERCENT RANGE
AGAIN ON MONDAY WITH SLIGHTLY BETTER CHANCES OF THUNDERSTORMS WITH
SOME SURFACE BASED INSTABILITY DEVELOPING ACROSS MAINLY CENTRAL AND
EASTERN OHIO. ALL AREAS SHOULD BE IN THE WARM SECTOR WITH HIGHS IN
THE MID 60S EXCEPT UPPER 50S NW PA. QPF FORECAST THROUGH MONDAY
NIGHT CONTINUES TO BE NEAR 1 INCH FOR MOST AREAS. LOCALLY HIGHER
RAINFALL IS EXPECTED WHERE THUNDERSTORMS DEVELOP. THE RAINFALL IS
STILL EXPECTED TO CAUSE RISES ON AREA RIVERS WITH ONLY A COUPLE
APPROACHING MINOR FLOOD STAGE...OTHERWISE NOT EXPECTING A LOT OF
FLOODING PROBLEMS.
SHORTWAVE RIDGING BUILDS ALOFT ON TUESDAY WITH TEMPERATURES RUNNING
AROUND 20 DEGREES ABOVE NORMAL FOR MID MARCH. THE NEXT SYSTEM TO
WATCH IN THIS ACTIVE PATTERN WILL DEVELOP OVER THE PLAINS ON TUESDAY
AS A STRONG PACIFIC JET RACES EASTWARD. AN ELONGATED SURFACE TROUGH
EXTENDING FROM THE NORTHERN PLAINS TO THE THE MISSOURI VALLEY WILL
CURL NORTHEAST TOWARDS THE WESTERN LAKES REGION TUESDAY NIGHT.
TRENDED TEMPERATURES UP ON TUESDAY NIGHT AND SUSPECT THEY WILL BE
RATHER WARM IN THE EAST AHEAD OF THE COLD FRONT. SCATTERED SHOWERS
WILL ALSO ACCOMPANY THE FRONT WITH BEST CHANCES FOR MORE
PRECIPITATION FOCUSED ACROSS THE WEST AND NORTH. VERY DRY AIR WRAPS
IN ON THE SOUTH SIDE OF THIS SYSTEM ON WEDNESDAY WITH GOOD
MIXING AND BREEZY CONDITIONS EXPECTED.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
PLENTY OF UNCERTAINTY BETWEEN THE MODELS AS THEY STRUGGLE WITH HOW
TO HANDLE THE WEAKENING AREA OF LOW PRESSURE OVER THE GREAT LAKES
REGION THURSDAY INTO FRIDAY. CURRENT THINKING IS THAT SCATTERED
SHOWERS WILL BE POSSIBLE ACROSS THE REGION ON THURSDAY WITH THE
COVERAGE DECREASING INTO FRIDAY. THERE IS NO CONSISTENCY IN THE
MODELS FOR SATURDAY WHICH LEADS TO LITTLE FORECAST CONFIDENCE. THERE
IS A 24 HOUR TIMING DIFFERENCE WITH THE APPROACH OF THE NEXT AREA OF
LOW PRESSURE THAT EMERGES FROM THE SOUTHERN PLAINS.
IT APPEARS THAT THE REGION WILL BE WARM ENOUGH TO KEEP ALL
PRECIPITATION IN THE FORM OF RAIN. HIGHS THROUGH THE LONG TERM WILL
BE AROUND SEASONAL AVERAGES.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
RAIN CONTINUES TO SPREAD NORTHWARD ACROSS THE REGION AS A WARM
FRONT SLOWLY DRIFTS TO THE NORTH FROM SOUTHERN OHIO. EXPECT TO SEE
CEILINGS LOWER TO MVFR LEVELS WITH THE NEXT ROUND OF MODERATE
SHOWERS THAT PIVOTS ACROSS THE REGION. THIS WILL SATURATE THE
LOWER LEVELS AND EVENTUALLY LEAD TO THE DEVELOPMENT OF IFR
CONDITIONS. THE RAIN AND LOWER CEILINGS WILL TAKE LONGEST TO REACH
KERI...LIKELY AFTER 18Z. AS THE WARM FRONT PASSES OVERNIGHT WINDS
WILL SHIFT FROM EASTERLY TO THE SOUTH AND SOUTHWEST. WIND SPEEDS
SHOULD BE UNDER 12 KNOTS EXCEPT AT KERI WHERE DOWNSLOPING WINDS MAY
GUST TO 25 KNOTS.
OUTLOOK...NON VFR CONDITIONS WILL CONTINUE AT TIMES MONDAY INTO
MONDAY NIGHT. NON VFR POSSIBLE AGAIN TUESDAY NIGHT.
&&
.MARINE...
NORTHEAST TO EAST WINDS WILL INCREASE TODAY AS A WEAK AREA OF LOW
PRESSURE MOVES INTO CENTRAL INDIANA THIS AFTERNOON. WINDS WILL
INCREASE TO 15 TO 20 KNOTS FOR LATE AFTERNOON INTO THE EVENING
ACROSS THE WESTERN HALF OF THE LAKE. WINDS OF THIS SPEED COMBINED
WITH A LONGER FETCH MAY BUILD WAVES CLOSE TO THE 4 FOOT THRESHOLD
FOR SMALL CRAFT CONDITIONS. FOR NOW HAVE HELD OFF ON A SMALL CRAFT
ADVISORY AND LET LATER SHIFTS MONITOR THIS POTENTIAL. WINDS WILL
DECREASE INTO MONDAY MORNING AS THEY SHIFT TO THE SOUTH. THE
GRADIENT WILL LIKELY BE LIGHT ENOUGH MONDAY AND TUESDAY FOR THE
DEVELOPMENT OF A LAKE BOUNDARY. THE LAKE BREEZE POTENTIAL LOOKS
GREATEST ON TUESDAY FROM CLEVELAND TO ERIE. SO EXPECT TO SEE ONSHORE
FLOW IN THIS REGION ON TUESDAY. BY TUESDAY NIGHT WINDS WILL BECOME
WEST TO SOUTHWEST AND THEN REMAIN THAT WAY INTO THURSDAY. SPEEDS OF
10 TO 20 KNOTS WILL BE COMMON.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KEC
NEAR TERM...KEC/ADAMS
SHORT TERM...KEC
LONG TERM...MULLEN
AVIATION...MULLEN
MARINE...MULLEN
AREA FORECAST DISCUSSION...UPDATED
NWS NORMAN OK
1121 AM CDT SUN MAR 13 2016
.UPDATE...
ADJUSTED POPS/WX FOR CONTINUING THUNDERSTORMS IN NORTHERN
OKLAHOMA...
&&
.DISCUSSION...
THE LINE OF THUNDERSTORMS THAT MOVED THROUGH CENTRAL AND WESTERN
OKLAHOMA EARLY THIS MORNING HAVE CONTINUED TO LIFT NORTHWARD...
WHILE BECOME LESS ORGANIZED. MOVING INTO A LESS FAVORABLE
ENVIRONMENT ALONG THE NORTHERN PERIPHERY OF THE SFC LOW... WEAKER
SHEAR AND INSTABILITY HAVE GIVEN WAY TO MORE BROKEN SHOWERS...
WITH POCKETS OF THUNDER AND HEAVIER RAINFALL. WITH THE LINE
SLOWING... STILL HAVE SOME MINOR CONCERNS FOR RISES ON CREEKS AND
STREAMS... RADAR ESTIMATES SUGGEST SOME ISOLATED AREAS IN DEWEY
AND BLAINE COUNTIES HAVE RECEIVED NEAR 2 INCHES OF RAINFALL.
THE LOW CHURNING ACROSS TEXOMA PRESENTLY IS IMPRESSIVE... VERY
COMPACT AND WELL DEFINED ON WATER VAPOR AND VISIBLE SAT. EXPECT
RAIN AND THUNDER TO CONTINUE ALONG THE NORTHERN EDGE OF THE LOW
CENTER AS IT TRACKS ACROSS SOUTHERN OKLAHOMA INTO THE AFTERNOON.
PER SPC MESO ANALYSIS AND SHORT RANGE GUIDANCE... INSTABILITY
CONTINUES TO GRADUALLY INCREASE AHEAD OF THE SHORT WAVE IN EAST
CENTRAL OKLAHOMA AND IN SOUTH CENTRAL OKLAHOMA... EAST OF THE
I-35 CORRIDOR DUE TO INCREASING SUNSHINE. LAST FEW FRAMES OF
VISIBLE IMAGERY SHOW SOME BROKEN CUMULUS DEVELOPMENT WITHIN THIS
REGION. LATEST RUN OF THE HRRR...13/15Z... HINTS AT SOME ISOLATED
CONVECTION THROUGH 18 TO 19Z NEAR ADA AND LOCATIONS TO THE EAST.
SHEAR AND INSTABILITY APPEAR SUFFICIENT ENOUGH TO GET A FEW
UPDRAFTS GOING... ESPECIALLY AS THE LOW CONTINUES TO SLIDE EAST.
COULD SEE A FEW STORMS DEVELOP ANYWHERE FROM NORTH OF DURANT TO
ADA AND INTO SOUTHERN SEMINOLE COUNTY. RAP BUFR SOUNDINGS FROM
ARDMORE HINT SMALL HAIL DEVELOPMENT IS POSSIBLE... UP TO HALF INCH
IN DIAMETER. HOWEVER... THE OVERALL BETTER CHANCES FOR STRONG TO
SEVERE STORM DEVELOPMENT WILL BE FARTHER TO THE EAST ACROSS
EAST/SOUTHEAST OKLAHOMA AND ARKANSAS.
JTK
&&
.PREV DISCUSSION... /ISSUED 712 AM CDT SUN MAR 13 2016/
AVIATION...
SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DEVELOP AHEAD OF
A FAST MOVING UPPER LOW THIS MORNING. THE STRONGER STORMS WILL
BE CAPABLE OF REDUCING THE VISIBILITY TO AROUND 1 MILE. RAIN-
COOLED AIR MAY ALSO RESULT IN IFR CEILINGS. BY 18Z...MOST OF THE
PRECIPITATION AND STORMS WILL BE EAST OF ALL TAF SITES.
PREV DISCUSSION... /ISSUED 420 AM CDT SUN MAR 13 2016/
DISCUSSION...
STRONG MID LEVEL ASCENT ASSOCIATED WITH THE MID TO UPPER LEVEL
LOW MOVING OVER THE SOUTHERN TX PANHANDLE CONTINUES TO SUPPER
ONGOING MOIST CONVECTION ACROSS NW OK EARLY THIS MORNING. THIS
ACTIVITY WILL SLOWLY SHIFT E THROUGH EARLY THIS AFTERNOON, WITH
THE HIGHEST CHCS REMAINING ALONG AND NORTH OF I40. MOST OF THE
MODELS HAVE A DECENT HANDLE ON THIS SCENARIO, WITH THE NAM12
INSTABILITY AXIS APPEARING VERY ACCURATE. WENT AHEAD AND BUMPED
POPS TO LIKELY FOR THIS MORNING, INCLUDING THE NORTHERN OKC METRO.
AT LEAST LOW RAIN CHCS WILL LINGER THROUGH MOST OF THE DAY ACROSS
NORTHERN AND PORTIONS OF OK NW OF THE MID LEVEL LOW. THIS WILL
KEEP TEMPS IN THE LOW TO MID 60S THERE. PATCHY FOG WILL ALSO BE
POSSIBLE THROUGH THE MORNING HOURS SOUTH OF THE LOW AND ALONG/EAST
OF I35. ANOTHER DENSE FOG ADVISORY MAY BE NEEDED FOR A SMALL AREA,
BUT WILL WAIT TO SEE IF DOWNWARD VISBY TRENDS CONTINUE. THE LOW
WILL EXIT OUR REGION AROUND 21Z, WITH SKIES CLEARING BEHIND IT
THROUGH THE EARLY EVENING. PATCHY FOG WILL AGAIN BE POSSIBLE MON
AM, BUT SHOULD REMAIN CONFINED TO ALONG AND EAST OF I35 WITH DRIER
AIR MOVING INTO THE WESTERN ZONES THANKS TO WESTERLY FLOW ON THE
BACK SIDE OF A SFC TROUGH.
IT STILL APPEARS VERY WARM MONDAY AS DOWNSLOPE FLOW DEVELOPS IN
COMBINATION WITH INCREASING HEIGHTS UNDER A SHORTWAVE RIDGE. THIS
WILL ESPECIALLY BE TRUE ACROSS SW OK AND WESTERN N TX WHERE SOME
LOCATIONS WILL REACH 90 DEGREES UNDER. WIND SPEEDS ACROSS SW OK
AND WESTERN N TX SHOULD REMAIN BELOW 20 MPH KEEPING FIRE WEATHER
CONDITIONS AT NEAR CRITICAL SO A FIRE WEATHER WATCH IS NOT NEEDED
FOR THE TIME BEING. ANOTHER MID TO UPPER TROUGH WILL PASS TO OUR
NORTH TUE AM, WITH AN ACCOMPANYING COLD FRONT FOLLOWING THROUGH
THE DAY. THIS FRONT WILL ONLY MANAGE TO KNOCK TEMPS BACK INTO THE
60S AND 70S TUE AFTERNOON. BREEZY NORTH WINDS ARE ALSO EXPECTED
ALONG WITH MUCH DRIER BOUNDARY LAYER CONDITIONS. THIS WILL AGAIN
RESULT IN ELEVATED TO NEAR CRITICAL FIRE WEATHER CONDITIONS MAINLY
ACROSS NORTHERN, WESTERN, AND SW OK, AND WESTERN N TX.
THE GENERAL TREND WED-THU WILL BE COOLER AND DRIER WITH AN
ADDITIONAL COLD FRONT POSSIBLE BY WED AS ANOTHER MID TO UPPER
SHORTWAVE TROUGH, WITHIN BROAD, DEEP TROUGH OVER THE NORTH CENTRAL
CONUS, DIGS DOWN THE ROCKIES AND INTO THE CENTRAL PLAINS. THE
TIMING OF THIS FRONT IS A BIT QUESTIONABLE, HOWEVER. RAIN CHCS
WILL INCREASE FRI THROUGH THIS WEEKEND AS A DEEPER SHORTWAVE
TROUGH AGAIN MOVES INTO THE ROCKIES. THERE ARE STILL A LOT OF
UNCERTAINTIES THROUGH THE EXTENDED WITH REGARDS TO HOW FAR SOUTH
THIS WAVE WILL MAKE IT, BUT THE OVERALL TREND WILL CERTAINLY BE
COLDER. SOME SNOWFALL EVEN APPEARS POSSIBLE OVER NW OK.
03
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 67 47 83 53 / 50 0 0 0
HOBART OK 69 46 86 51 / 10 0 0 0
WICHITA FALLS TX 73 48 88 53 / 10 0 0 0
GAGE OK 68 41 83 47 / 60 0 0 0
PONCA CITY OK 64 45 82 50 / 60 0 0 0
DURANT OK 72 51 82 57 / 20 0 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1132 PM EDT MON MAR 14 2016
.SYNOPSIS...
AN UPPER TROUGH AND TWO WEAK AREAS OF LOW PRESSURE WILL DRIFT
NORTHEAST ACROSS THE MID ATLANTIC REGION TONIGHT AND EARLY
TUESDAY. AFTER A MOSTLY CLOUDY BUT TRANQUIL DAY TUESDAY...A WEAK
COLD FRONT WILL CROSS THE STATE WEDNESDAY. COOLER AND UNSETTLED
CONDITIONS WITH A FEW RAIN SHOWERS WILL OCCUR THURSDAY. THE
SCATTERED RAIN SHOWERS WILL MIX WITH WET SNOW SHOWERS FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
LITTLE CHANGE LATE THIS EVENING...AS LLVL EASTERLY FLOW OF COOL
MOIST AIR HAS LOW CLOUDS LOCKED IN ACROSS THE ENTIRE FORECAST AREA
WITH WIDESPREAD LOW STRATUS..WITH FOG BLANKETING THE RIDGE TOPS.
SHOWERS OVER SOUTHWEST PA ARE STILL FORECAST TO DAMPEN AS PER
LATEST HI RES HRRR AND WRF ARW RUNS...RUNNING INTO THE COOL STABLE
AIR OVER CENTRAL AND EASTERN PA OVERNIGHT. HOWEVER...GIVEN THE
FORCING ARRIVING OVERNIGHT ASSOCIATED WITH THE 5H UPPER TROF...DO
EXPECT HIGH CHC TO LIKELY POPS TO IMPACT THE WEST CENTRAL AND
LAUREL HIGHLANDS BEFORE TAPERING FARTHER EAST. OVER THE CENTRAL
AND EAST...SHOWERS WILL BE MORE SCARCE...BUT DRIZZLE WILL BE
PREVALENT THROUGH EARLY TUESDAY MORNING.
LOWS TONIGHT WILL BE IN THE MID 30S...TO NEAR 40F IN THE LOWER
SUSQ REGION.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
THE WEAKENING SHORTWAVE OVER KENTUCKY THIS AFTERNOON WILL LIFT NE
AND CLEAR OUR AREA BY EARLY AFTERNOON TUESDAY...LEADING TO
ANOTHER RELATIVE LULL IN THE OFF AND ON SHOWER REGIME. CLOUDS WILL
CONTINUE TO HANG TOUGH AS PWATS REMAIN ABOVE NORMAL AND THERE WILL
BE VERY LITTLE PUSH OF DRY AIR TO DISLODGE THE MOISTURE.
WE SHOULD SEE TEMPERATURES REBOUND ABOVE TODAY`S CHILLY READINGS
HOWEVER...MAKING IT BACK INTO THE MID TO UPPER 50S.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
ISSUED 300 PM EDT MONDAY MARCH 14 2016
CONSENSUS OF GUIDANCE SHOWS AN AMPLIFIED SHORTWAVE TROUGH/CLOSED
500MB LOW PIVOTING NORTHWARD OVER THE UPPER MIDWEST AND WESTERN
GREAT LAKES REGION ON DAY 3/WED. A REX BLOCK FORMS BRIEFLY WITH
A CLOSED UPPER HIGH OVER MANITOBA. AT THE SURFACE...AN OCCLUDED
LOW IS FCST TO DRIFT N ACROSS WI WITH AN OCCLUDED COLD FRONT
ARCING DOWNSTREAM AND PUSHING E ACROSS THE APPALACHIANS/MID-
ATLANTIC STATES. MODELS GENERALLY AGREE IN GENERATING SHOWERS
ALONG/AHEAD OF THE OCCLUDED FRONT WITH SOME ELEVATED THUNDER
POTENTIAL.
THE INITIAL BLOCKING PATTERN OVER SRN CANADA AND THE NRN CONUS
WILL ULTIMATELY EVOLVE INTO A CNTRL-ERN U.S. MEAN TROUGH THAT
COULD SUPPORT A STRONGLY DEVELOPING SFC SYSTEM IN THE MID-ATLANTIC
AND NORTHEAST STATES THIS WEEKEND INTO MONDAY. THERE ARE STILL
IMPORTANT MODEL DIFFERENCES THAT REMAIN UNRESOLVED WITH INDIVIDUAL
ENSEMBLE MEMBERS VERY DISPERSED SUN-MON IN A LOW TRACK RANGING
FROM WELL INLAND TO OFFSHORE. THEREFORE THE DEGREE OF CERTAINTY
OR CONFIDENCE IN FORECAST DETAILS IS LOW/BELOW AVERAGE AT THIS
TIME.
SENSIBLE WEATHER HIGHLIGHTS WILL BE A SEASONABLE COOLING TREND BY
THE END OF THE PERIOD FROM THE MID-WEEK PEAK/ANOMALOUS WARMTH.
THERE IS A LARGE SPREAD IN THE SFC LOW TRACK LATE IN THE PERIOD
WHICH TEMPERS CONFIDENCE IN DETERMINING PRECIP EXTENT/TIMING AND
TYPE. A LATE SEASON SNOW EVENT IS A POSSIBLE OUTCOME BUT THE ODDS
ARE VERY LOW AT THIS POINT.
&&
.AVIATION /04Z TUESDAY THROUGH SATURDAY/...
A MOIST LLVL EASTERLY FLOW IS PRODUCING WIDESPREAD IFR CIGS ACROSS
CENTRAL PA AS OF 03Z...WITH LIFR NOTED ACROSS THE HIGH TERRAIN
AIRFIELDS /KBFD AND KJST/. ONLY KIPT REMAINS MVFR...BUT BULK OF
MDL GUIDANCE INDICATES A BIT OF RADIATIONAL COOLING LIKELY CAUSE
CIGS TO DIP BLW 1KFT THERE FOR A TIME EARLY TUE AM.
EARLIER LINE OF TSRA FELL APART BEFORE REACHING CENTRAL PA...AS
ASSOC MID LVL DISTURBANCE WEAKENED AND LINE ENCOUNTERED A MORE
STABLE AIR MASS ACROSS PA.
SOME MODEST IMPROVEMENT TO WIDESPREAD MVFR CIGS WILL LIKELY OCCUR
BY TUES AFTERNOON...AS MOIST EASTERLY FLOW WEAKENS.
PARTIAL CLEARING...LIGHT WIND AND WET GROUND ASSOC WITH ARRIVAL
OF SFC RIDGE WILL LIKELY YIELD AREAS OF RADIATION FOG TUE NIGHT.
OUTLOOK...
WED...AM FOG POSSIBLE. ISOLD PM TSRA IMPACTS POSSIBLE.
THU...NO SIG WX EXPECTED.
FRI...SHSN/VIS REDUCTIONS POSS W MTNS.
SAT...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...DEVOIR/LAMBERT
SHORT TERM...LAMBERT
LONG TERM...STEINBUGL
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1016 PM EDT MON MAR 14 2016
.SYNOPSIS...
AN UPPER TROUGH AND TWO WEAK AREAS OF LOW PRESSURE WILL DRIFT
NORTHEAST ACROSS THE MID ATLANTIC REGION TONIGHT AND EARLY
TUESDAY. AFTER A MOSTLY CLOUDY BUT TRANQUIL DAY TUESDAY...A WEAK
COLD FRONT WILL CROSS THE STATE WEDNESDAY. COOLER AND UNSETTLED
CONDITIONS WITH A FEW RAIN SHOWERS WILL OCCUR THURSDAY. THE
SCATTERED RAIN SHOWERS WILL MIX WITH WET SNOW SHOWERS FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
LITTLE CHANGE LATE THIS EVENING...AS LLVL EASTERLY FLOW OF COOL
MOIST AIR HAS LOW CLOUDS LOCKED IN ACROSS THE ENTIRE FORECAST AREA
WITH WIDESPREAD LOW STRATUS..WITH FOG BLANKETING THE RIDGE TOPS.
SHOWERS OVER SOUTHWEST PA ARE STILL FORECAST TO DAMPEN AS PER
LATEST HI RES HRRR AND WRF ARW RUNS...RUNNING INTO THE COOL STABLE
AIR OVER CENTRAL AND EASTERN PA OVERNIGHT. HOWEVER...GIVEN THE
FORCING ARRIVING OVERNIGHT ASSOCIATED WITH THE 5H UPPER TROF...DO
EXPECT HIGH CHC TO LIKELY POPS TO IMPACT THE WEST CENTRAL AND
LAUREL HIGHLANDS BEFORE TAPERING FARTHER EAST. OVER THE CENTRAL
AND EAST...SHOWERS WILL BE MORE SCARCE...BUT DRIZZLE WILL BE
PREVALENT THROUGH EARLY TUESDAY MORNING.
LOWS TONIGHT WILL BE IN THE MID 30S...TO NEAR 40F IN THE LOWER
SUSQ REGION.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
THE WEAKENING SHORTWAVE OVER KENTUCKY THIS AFTERNOON WILL LIFT NE
AND CLEAR OUR AREA BY EARLY AFTERNOON TUESDAY...LEADING TO
ANOTHER RELATIVE LULL IN THE OFF AND ON SHOWER REGIME. CLOUDS WILL
CONTINUE TO HANG TOUGH AS PWATS REMAIN ABOVE NORMAL AND THERE WILL
BE VERY LITTLE PUSH OF DRY AIR TO DISLODGE THE MOISTURE.
WE SHOULD SEE TEMPERATURES REBOUND ABOVE TODAY`S CHILLY READINGS
HOWEVER...MAKING IT BACK INTO THE MID TO UPPER 50S.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
ISSUED 300 PM EDT MONDAY MARCH 14 2016
CONSENSUS OF GUIDANCE SHOWS AN AMPLIFIED SHORTWAVE TROUGH/CLOSED
500MB LOW PIVOTING NORTHWARD OVER THE UPPER MIDWEST AND WESTERN
GREAT LAKES REGION ON DAY 3/WED. A REX BLOCK FORMS BRIEFLY WITH
A CLOSED UPPER HIGH OVER MANITOBA. AT THE SURFACE...AN OCCLUDED
LOW IS FCST TO DRIFT N ACROSS WI WITH AN OCCLUDED COLD FRONT
ARCING DOWNSTREAM AND PUSHING E ACROSS THE APPALACHIANS/MID-
ATLANTIC STATES. MODELS GENERALLY AGREE IN GENERATING SHOWERS
ALONG/AHEAD OF THE OCCLUDED FRONT WITH SOME ELEVATED THUNDER
POTENTIAL.
THE INITIAL BLOCKING PATTERN OVER SRN CANADA AND THE NRN CONUS
WILL ULTIMATELY EVOLVE INTO A CNTRL-ERN U.S. MEAN TROUGH THAT
COULD SUPPORT A STRONGLY DEVELOPING SFC SYSTEM IN THE MID-ATLANTIC
AND NORTHEAST STATES THIS WEEKEND INTO MONDAY. THERE ARE STILL
IMPORTANT MODEL DIFFERENCES THAT REMAIN UNRESOLVED WITH INDIVIDUAL
ENSEMBLE MEMBERS VERY DISPERSED SUN-MON IN A LOW TRACK RANGING
FROM WELL INLAND TO OFFSHORE. THEREFORE THE DEGREE OF CERTAINTY
OR CONFIDENCE IN FORECAST DETAILS IS LOW/BELOW AVERAGE AT THIS
TIME.
SENSIBLE WEATHER HIGHLIGHTS WILL BE A SEASONABLE COOLING TREND BY
THE END OF THE PERIOD FROM THE MID-WEEK PEAK/ANOMALOUS WARMTH.
THERE IS A LARGE SPREAD IN THE SFC LOW TRACK LATE IN THE PERIOD
WHICH TEMPERS CONFIDENCE IN DETERMINING PRECIP EXTENT/TIMING AND
TYPE. A LATE SEASON SNOW EVENT IS A POSSIBLE OUTCOME BUT THE ODDS
ARE VERY LOW AT THIS POINT.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
A MOIST LLVL EASTERLY FLOW IS PRODUCING WIDESPREAD IFR/LOW MVFR
CIGS ACROSS CENTRAL PA AT 00Z. BULK OF MDL GUIDANCE INDICATES A
BIT OF RADIATIONAL COOLING WILL CAUSE CIGS TO FALL SLIGHTLY
OVERNIGHT...WITH WIDESPREAD IFR/LIFR CONDS LIKELY.
LINE OF TSRA APPROACHING FROM OHIO WILL FALL APART BEFORE
REACHING CENTRAL PA OVERNIGHT...AS ASSOC MID LVL DISTURBANCE
WEAKENS AND LINE ENCOUNTERS A MORE STABLE AIR MASS ACROSS PA.
SOME MODEST IMPROVEMENT TO WIDESPREAD MVFR CIGS WILL LIKELY OCCUR
BY TUES AFTERNOON...AS MOIST EASTERLY FLOW WEAKENS.
PARTIAL CLEARING...LIGHT WIND AND WET GROUND ASSOC WITH ARRIVAL
OF SFC RIDGE WILL LIKELY YIELD AREAS OF RADIATION FOG TUE NIGHT.
OUTLOOK...
WED...AM FOG POSSIBLE. ISOLD PM TSRA IMPACTS POSSIBLE.
THU...NO SIG WX EXPECTED.
FRI...SHSN/VIS REDUCTIONS POSS W MTNS.
SAT...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...DEVOIR/LAMBERT
SHORT TERM...LAMBERT
LONG TERM...STEINBUGL
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
603 PM EDT SUN MAR 13 2016
.SYNOPSIS...
PERIODS OF RAIN AND DRIZZLE ARE EXPECTED TO CONTINUE THROUGH
TUESDAY. THE CHANCE OF RAIN SHOWERS WILL REMAIN IN THE FORECAST
THROUGH THE END OF THE WEEK...ALTHOUGH AERIAL COVERAGE AND
AMOUNTS APPEAR LIMITED. TEMPERATURES WILL BE SEASONABLY MILDER
RELATIVE TO NORMAL FOR THIS TIME OF YEAR.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
MOIST PLUME OF 1.0"+ PW ADVANCING INTO CENTRAL PA BUT ENCOUNTERING
DRY AIR EAST AND OF H5 RIDGE AXIS. STEADY BUT LIGHT RAINFALL
ACCOMPANIES PERSISTENT MOISTURE ADVECTION AND ISENTROPIC UPGLIDE
ALONG AND TO THE NORTH OF WARM FRONTAL ZONE LOCATED SOUTH OF
PENNSYLVANIA THIS EVENING...WHICH WILL MAINTAIN PERIODS OF LIGHT
RAIN AND DRIZZLE THROUGH TONIGHT.
COLD AIR DAMMING WILL BECOME MORE PRONOUNCED AND STRENGTHEN
OVERNIGHT AS HIGH PRESSURE CHANNELS TO THE EAST OF THE
APPALACHIANS. EAST/SOUTHEAST WINDS WILL INCREASE INTO EARLY MONDAY
MORNING WITH 20+ MPH GUSTS FROM THE SOUTHERN POCONOS INTO THE LWR
SUSQ VALLEY. ADDITIONAL RAINFALL AMOUNTS THROUGH 12Z MONDAY RANGE
FROM 0.10-0.25 INCH OVER THE FAR NORTHERN TIER TO 0.50-1.00 INCHES
ACROSS THE SOUTH-CENTRAL RIDGES INTO THE LWR SUSQ. VALLEY.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
ISSUED AT 220 PM EDT SUN MARCH 13 2016
HIRES MODEL/NCAR EFS LIFTED INDEX SHOWS STRONG CAD SIGNATURE WITH
COOL/STABLE AIRMASS LOCKED IN THE BOUNDARY LAYER ALONG/EAST OF THE
ALLEGHENIES. EXPECT STEADIER RAINS TO TRANSITION TO MORE OCNL
LIGHT RAIN AND DRIZZLE THROUGH THE PERIOD. DAYTIME MAX TEMPS WILL
STRUGGLE TO GET OUT OF THE 40S. 13/12Z GUIDANCE SHOWS A WEAKENING
SHORTWAVE PASSING TO THE SOUTH OF MON NIGHT...WITH LOW PRESSURE
DEVELOPMENT OFF THE MID ATLANTIC COAST BY TUESDAY MORNING. MEAN
QPF PLACES CENTRAL PA IN A RELATIVE MINIMUM WITH 24HR TOTALS LESS
THAN 0.25 INCH ENDING 12Z TUESDAY.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
LOW PRESSURE SHOULD BE PULLING EAST OF THE AREA EARLY
TUESDAY...AFTER WHICH THE PATTERN BECOMES COMPLICATED AND
DIFFERENCES IN MODEL SOLUTIONS BEGIN TO ARISE.
THERE IS GENERAL AGREEMENT IN SOME ENERGY DIGGING INTO THE
NORTHERN PLAINS BY LATER TUESDAY. BOTH THE GEFS/ECMWF DEVELOP A
REX BLOCK BY WED WITH THE UPPER-LEVEL LOW OVER THE NRN PLAINS/WRN
GLAKES AND THE HIGH JUST SOUTH OF HUDSONS BAY.
THERE IS PRETTY GOOD OVERALL AGREEMENT IN A COOLER END OF THE
WEEK. THE QUESTION WILL BE THE TIMING OF DISTURBANCES RIPPLING
UNDER THE GR LAKES LOW.
&&
.AVIATION /22Z SUNDAY THROUGH FRIDAY/...
A STALLED FRONTAL BOUNDARY SOUTH OF THE STATE WILL BRING
DETERIORATING FLYING CONDS TO CENTRAL PA OVERNIGHT AND MONDAY IN
THE FORM OF OCNL RAIN AND LOWERING CIGS. RAIN ALREADY FALLING
ACROSS MUCH OF CENTRAL PA AS OF 21Z...BUT DRY AIR IN THE BOUNDARY
LAYER HAS KEPT CONDS MAINLY VFR. ALL MDL GUIDANCE INDICATING
GRADUALLY LOWERING CIGS OVERNIGHT...AS RAIN MOISTENS THE LOW
LVLS. LATEST SREF PROBS AND HRRR SUPPORT IFR CIGS AT KJST/KAOO BY
LATER THIS EVENING. THE IFR CONDS APPEAR LIKELY TO SPREAD TO KUNV
AND PERHAPS KBFD/KMDT/KLNS BY DAWN MONDAY. THE DRY AIR WILL REMAIN
MOST PERSISTENT ACROSS NORTHEAST PA...WHERE KIPT IS LIKELY TO
EXPERIENCE NO WORSE THAN MVFR CONDS LATER TONIGHT.
A PROLONGED PERIOD OF MVFR/IFR APPEARS TO BE IN STORE THROUGH THE
FIRST PART OF THE WEEK AS STRENGTHENING HIGH PRESSURE TO THE NORTH
OF MAINE LOCKS IN COLD AIR DAMMING PATTERN IN THE LOW
LEVELS...WHICH IS CONDUCIVE FOR LONG DURATION SUB-VFR CONDITIONS.
OUTLOOK...MONDAY-THURSDAY
MON-TUE...MVFR-IFR WITH OCNL LGT RAIN/DZ/FOG.
WED...IMPROVING CIGS/VIS. CHC P.M RAIN SHOWERS. FROPA.
THU...CHC OF RAIN SHOWERS. LOW RISK FOR SUB-VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...DEVOIR/STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...EVANEGO
AVIATION...FITZGERALD/STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
545 PM EDT SUN MAR 13 2016
.SYNOPSIS...
PERIODS OF RAIN AND DRIZZLE ARE EXPECTED TO CONTINUE THROUGH
TUESDAY. THE CHANCE OF RAIN SHOWERS WILL REMAIN IN THE FORECAST
THROUGH THE END OF THE WEEK...ALTHOUGH AERIAL COVERAGE AND
AMOUNTS APPEAR LIMITED. TEMPERATURES WILL BE SEASONABLY MILDER
RELATIVE TO NORMAL FOR THIS TIME OF YEAR.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
ISSUED AT 220 PM EDT SUN MARCH 13 2016
ABOVE NORMAL PW ALONG WITH PERSISTENT MOISTURE ADVECTION AND
ISENTROPIC UPGLIDE ALONG AND TO THE NORTH OF A Q-STATIONARY/WARM
FRONTAL ZONE LOCATED TO THE SOUTH OF PENNSYLVANIA WILL MAINTAIN
PERIODS OF LIGHT RAIN AND DRIZZLE THROUGH TONIGHT. DRY AIR
ENTRENCHED IN THE LOW LEVELS WILL EVENTUALLY BE OVERCOME WITH
LIGHT RAIN REACHING NORTHERN AREAS LATER TONIGHT. COLD AIR DAMMING
WILL BECOME MORE PRONOUNCED AND STRENGTHEN OVERNIGHT AS HIGH
PRESSURE CHANNELS TO THE EAST OF THE APPALACHIANS. EAST/SOUTHEAST
WINDS WILL INCREASE INTO EARLY MONDAY MORNING WITH 20+ MPH GUSTS
FROM THE SOUTHERN POCONOS INTO THE LWR SUSQ VALLEY. ADDITIONAL
RAINFALL AMOUNTS THROUGH 12Z MONDAY RANGE FROM 0.10-0.25 INCH OVER
THE FAR NORTHERN TIER TO 0.50-1.00 INCHES ACROSS THE SOUTH-CENTRAL
RIDGES INTO THE LWR SUSQ. VALLEY.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
ISSUED AT 220 PM EDT SUN MARCH 13 2016
HIRES MODEL/NCAR EFS LIFTED INDEX SHOWS STRONG CAD SIGNATURE WITH
COOL/STABLE AIRMASS LOCKED IN THE BOUNDARY LAYER ALONG/EAST OF THE
ALLEGHENIES. EXPECT STEADIER RAINS TO TRANSITION TO MORE OCNL
LIGHT RAIN AND DRIZZLE THROUGH THE PERIOD. DAYTIME MAX TEMPS WILL
STRUGGLE TO GET OUT OF THE 40S. 13/12Z GUIDANCE SHOWS A WEAKENING
SHORTWAVE PASSING TO THE SOUTH OF MON NIGHT...WITH LOW PRESSURE
DEVELOPMENT OFF THE MID ATLANTIC COAST BY TUESDAY MORNING. MEAN
QPF PLACES CENTRAL PA IN A RELATIVE MINIMUM WITH 24HR TOTALS LESS
THAN 0.25 INCH ENDING 12Z TUESDAY.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
LOW PRESSURE SHOULD BE PULLING EAST OF THE AREA EARLY
TUESDAY...AFTER WHICH THE PATTERN BECOMES COMPLICATED AND
DIFFERENCES IN MODEL SOLUTIONS BEGIN TO ARISE.
THERE IS GENERAL AGREEMENT IN SOME ENERGY DIGGING INTO THE
NORTHERN PLAINS BY LATER TUESDAY. BOTH THE GEFS/ECMWF DEVELOP A
REX BLOCK BY WED WITH THE UPPER-LEVEL LOW OVER THE NRN PLAINS/WRN
GLAKES AND THE HIGH JUST SOUTH OF HUDSONS BAY.
THERE IS PRETTY GOOD OVERALL AGREEMENT IN A COOLER END OF THE
WEEK. THE QUESTION WILL BE THE TIMING OF DISTURBANCES RIPPLING
UNDER THE GR LAKES LOW.
&&
.AVIATION /22Z SUNDAY THROUGH FRIDAY/...
A STALLED FRONTAL BOUNDARY SOUTH OF THE STATE WILL BRING
DETERIORATING FLYING CONDS TO CENTRAL PA OVERNIGHT AND MONDAY IN
THE FORM OF OCNL RAIN AND LOWERING CIGS. RAIN ALREADY FALLING
ACROSS MUCH OF CENTRAL PA AS OF 21Z...BUT DRY AIR IN THE BOUNDARY
LAYER HAS KEPT CONDS MAINLY VFR. ALL MDL GUIDANCE INDICATING
GRADUALLY LOWERING CIGS OVERNIGHT...AS RAIN MOISTENS THE LOW
LVLS. LATEST SREF PROBS AND HRRR SUPPORT IFR CIGS AT KJST/KAOO BY
LATER THIS EVENING. THE IFR CONDS APPEAR LIKELY TO SPREAD TO KUNV
AND PERHAPS KBFD/KMDT/KLNS BY DAWN MONDAY. THE DRY AIR WILL REMAIN
MOST PERSISTENT ACROSS NORTHEAST PA...WHERE KIPT IS LIKELY TO
EXPERIENCE NO WORSE THAN MVFR CONDS LATER TONIGHT.
A PROLONGED PERIOD OF MVFR/IFR APPEARS TO BE IN STORE THROUGH THE
FIRST PART OF THE WEEK AS STRENGTHENING HIGH PRESSURE TO THE NORTH
OF MAINE LOCKS IN COLD AIR DAMMING PATTERN IN THE LOW
LEVELS...WHICH IS CONDUCIVE FOR LONG DURATION SUB-VFR CONDITIONS.
OUTLOOK...MONDAY-THURSDAY
MON-TUE...MVFR-IFR WITH OCNL LGT RAIN/DZ/FOG.
WED...IMPROVING CIGS/VIS. CHC P.M RAIN SHOWERS. FROPA.
THU...CHC OF RAIN SHOWERS. LOW RISK FOR SUB-VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...EVANEGO
AVIATION...FITZGERALD/STEINBUGL
FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION
VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
936 PM EDT MON MAR 14 2016
.SYNOPSIS...
A WAVE OF LOW PRESSURE WILL TRACK EAST OF THE AREA OVERNIGHT WHICH
WILL BRING AN END TO ONGOING SHOWERS AND STORMS LATE. WEAK HIGH
PRESSURE SHOULD ARRIVE BY TUESDAY AND PROVIDE DRY AND UNSEASONABLY
WARM CONDITIONS FOR THE MIDDLE OF THIS WEEK.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
AS OF 920 PM EDT MONDAY...
AXIS OF DEEPER CONVECTION NOW SWINGING EAST OF THE BLUE RIDGE
WHERE THE WEDGE CONTINUES TO LINGER IN PLACE. THUS EXPECT WILL SEE
MOST STORMS WEAKEN AND BECOME MORE ELEVATED UPON CROSSING DEEPER
INTO THE COOL POOL. HOWEVER STILL COULD SEE SOME SPOTTY HAIL SO
LEAVING IN THUNDER MENTION UNTIL AROUND MIDNIGHT ACROSS AREAS
ROUGHLY FROM LYH TO DAN AND POINTS EAST. LATEST HRRR THEN SHOWS
THIS BAND OF LIFT HEADING EAST/NE OF THE CWA AFTER MIDNIGHT WITH
SUBSIDENCE SPILLING IN UNDER THE MAIN SHORTWAVE THAT WILL PASS
OVERHEAD SHORTLY AND TO THE EAST OVERNIGHT. THIS SHOULD ALSO ALLOW
FOR A DECREASE IN SHOWERS OVER THE WEST BUT ENOUGH WEAK UPSLOPE
AND WRAP AROUND TRAJECTORY TO KEEP SOME CHANCE POPS GOING INTO THE
EARLY MORNING HOURS. WILL MAKE SOME SLIGHT ADJUSTS TO TEMPS TO
NUDGE DOWN WHERE ALREADY AT FORECAST LOWS BUT GIVEN SATURATION NOT
EXPECTING VALUES TO FALL MUCH OVERNIGHT.
PREVIOUS DISCUSSION AS OF 345 PM EDT MONDAY...
THE SITUATION IS CURRENTLY UNFOLDING AS ADVERTISED WITH THE
LINGERING WEDGE HOLDING ON IN THE PIEDMONT WITH THUNDERSTORMS
DEVELOPING IN THE MORE UNSTABLE AIR TO THE SOUTH AND WEST. THE
CONVECTION IS BEING DRIVEN BY AN ACTIVE UPPER LEVEL SHORT WAVE
WHICH WILL HELP STEEPEN LAPSE RATES THROUGH THE EVENING. CURRENTLY
BELIEVE THE CONVECTION WILL MOVE ACROSS THE REGION AND CLEAR THE
EASTERN ZONES AROUND MIDNIGHT. THUNDER CHANCES WILL BE LEAST WHERE
THE WEDGE IS HOLDING ON BUT OTHER LOCATIONS WHERE CONVECTION DOES
FIRE WILL BE DEALING HAIL PRODUCING STORMS WITH A SLIGHT THREAT
FOR LARGE HAIL AND GUSTY WINDS.
LATER TONIGHT BEHIND THE SHORT WAVE EXPECT SOME LINGERING SHOWERS
WEST OF THE BLUE RIDGE THAT WILL GRADUALLY TAPER OFF AROUND
DAYBREAK TUESDAY. NO CHANGE OF AIRMASS SO LOWS TONIGHT WILL REMAIN
SOMEWHAT MILD IN THE UPPER 40S TO LOWER 50S...WITH HIGHS ON
TUESDAY GENERALLY UPPER 60S/NEAR 70 WEST OF THE RIDGE TO MIDDLE
70S EAST.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY NIGHT/...
AS OF 345 PM EDT MONDAY...
SHORTWAVE RIDGING TO TAKE PLACE TUESDAY NIGHT AHEAD OF A DEEPENING
NEGATIVE TILT TROUGH OVER THE NORTHERN PLAINS INTO THE LOWER GREAT
LAKES. A WARM FRONT IS EXPECTED TO LIFT NORTHEAST THROUGH THE
CENTRAL APPALACHIANS LATE TUESDAY NIGHT WITH SOME LIGHT SHOWERS
POSSIBLE ACROSS THE MOUNTAINS. LOWS WILL BE MILD IN THE UPPER 40S TO
MID 50S.
WEDNESDAY....AN WESTERLY FLOW AT LOW AND MID LEVELS WITH INCREASING
SUNSHINE WILL ALLOW FOR TEMPS TO GET WELL INTO THE 70S MAINLY EAST
OF THE BLUE RIDGE...WITH SOME IN SOUTHSIDE VA INTO THE NC PIEDMONT
REACHING 80. THE MOUNTAINS WILL STAY WARM AS WELL WITH UPPER 60S TO
LOWER 70S. COULD SEE A FEW SHOWERS WED MORNING.
WEDNESDAY NIGHT FRONTAL SYSTEM MOVES ACROSS WITH 5H HEIGHTS FALLING
AS UPPER LOW MOVES ACROSS THE GREAT LAKES. MOISTURE IS LIMITED WITH
THIS SYSTEM...SO NOT LOOKING AT ANY THREAT OF RAIN...MAY BE SOME
LIGHT SHOWERS ACROSS THE SOUTHERN AND CENTRAL APPALACHIANS. TEMPS
WILL BE SLIGHTLY COOLER BUT ABOVE NORMAL IN THE 40S.
THURSDAY...A SFC WAVE STARTS TO FORM ALONG THE FRONT ACROSS THE GULF
COAST STATES AND SOUTHEAST. THIS MAY ACT TO BRING SOME MOISTURE OUR
WAY WITH THE FRONT NEARBY BUT STILL NOT EXPECTING ANY DECENT
CHANCES...SO HAVE POPS LOW CHANCE WV TO SLIGHT CHANCE ELSEWHERE.
TEMPS WILL BE ABOUT 10 DEGREES COOLER THAN WEDNESDAY BUT STILL WARM
FOR MID MARCH WITH UPPER 50S TO MID 60S WEST...TO AROUND 70
SOUTHEAST.
THINGS WILL BE CLEARING OUT THURSDAY NIGHT AS 5H HEIGHTS CONTINUE
FALLING...WITH MAIN TROUGH AXIS FROM THE GREAT LAKES TO THE CENTRAL
APPALACHIANS AND TN VALLEY. LOWS WILL RANGE FROM THE MID TO UPPER
30S WEST...TO LOWER TO MID 40S EAST.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 345 PM EST MONDAY...
FORECAST THIS PERIOD REMAINS SOMEWHAT SKETCHY BUT ALL MODELS
INDICATE BACK TO NORMAL OR JUST BELOW NORMAL TEMPERATURES.
FRIDAY WILL BE DRY...THOUGH SOME SHORTWAVE ENERGY SHOULD BRING
INCREASING MID AND HIGH CLOUDS TO THE AREA. FRIDAY WILL STILL BE
MILD BEFORE THE TROUGH SLIPS SOUTHEAST OVER THE WEEKEND...WITH HIGHS
IN THE 50S WEST TO LOWER TO MID 60S EAST.
FRONTAL BOUNDARY WILL BE STALLED NEAR THE GULF COAST FRIDAY....INTO
SATURDAY. COLD HIGH PRESSURE WILL SLIDE ACROSS THE GREAT LAKES INTO
THE NORTHEAST. AS THE UPPER LOW MOVES ACROSS THE OHIO VALLEY
SATURDAY NIGH INTO SUNDAY...THE FRONTAL BOUNDARY WILL SLIDE NORTH
ACROSS US WITH LOW PRESSURE FORMING ACROSS THE EASTERN PORTIONS OF
THE CAROLINAS...WITH SECOND LOW OVER THE UPPER OHIO VALLEY.
CURRENTLY....CRITICAL THICKNESSES AND TEMPS WILL KEEP PRECIP MAINLY
RAIN...BUT AS COLDER MOVES ACROSS BEHIND THE LOW SOME SNOW MAY OCCUR
OVER THE HIGHER TERRAIN SUNDAY NIGHT INTO MONDAY MORNING...BUT BY
THEN THE DEEPER MOISTURE WILL BE EXITING. STILL BEARS WATCH AS
COLDER AIR AND UPPER LOW MAY BE CLOSE ENOUGH TO BRING SOME HIGH
ELEVATIONS SNOWS TO THE CENTRAL AND SOUTHERN APPALACHIANS.
THE WEEKEND INTO MONDAY WILL BE COOL...WITH LOWS MAINLY IN THE
30S...AND HIGHS RANGING FROM THE 40S WEST TO LOWER TO MID 50S EAST.
&&
.AVIATION /01Z TUESDAY THROUGH SATURDAY/...
AS OF 711 PM EDT MONDAY...
THE WEDGE CONTINUES TO LINGER ALONG/EAST OF THE BLUE RIDGE THIS
EVENING WITH WIDESPREAD IFR/LIFR IN FOG AND LOW CIGS PERSISTING.
HOWEVER DEEPER CONVECTION ARRIVING FROM THE WEST OVER THE NEXT FEW
HOURS SHOULD HELP SCOUR OUT SOME OF THE LOWER CIGS AS HEAVIER
RAINFALL ARRIVES. WILL BE CONFINING THE SHRA/TSRA TO MAINLY BEFORE
MIDNIGHT AS THE SHORT WAVE PASSES WITH ALL SITES CLEAR OF THUNDER
BY THE EARLY MORNING HOURS. BELIEVE THERE WILL BE SOME CLEARING
BEHIND THE CONVECTION...BUT WITH HIGH AMBIENT MOISTURE FOLLOWING
THE SHRA/TSRA EXPECT SOME LOW CIGS/FOG WILL DEVELOP. WILL CONTINUE
TO BROAD BRUSH FOR THE LOWEST CONDITIONS INTO THE OVERNIGHT. LOW
CIGS/FOG WILL BE DISSIPATING AFTER DAYBREAK TUESDAY WITH VFR EAST
OF THE RIDGE AND LINGERING MVFR WEST...WITH ALL BECOMING VFR IN
THE AFTERNOON.
EXTENDED DISCUSSION...
HIGH PRESSURE WILL ALLOW GOOD FLYING WEATHER FOR WEDNESDAY
AFTERNOON THROUGH THURSDAY MORNING. THURSDAY AFTERNOON THROUGH
FRIDAY APPEAR GENERALLY DRY...BUT CONFIDENCE IS LOW FOR THIS PART
OF THE FORECAST DUE TO LARGE DIFFERENCES IN THE MODELS. ANOTHER
STRONGER WEATHER SYSTEM WILL LIKELY BRING RAIN AND SUB-VFR
CONDITIONS TO MUCH OF THE AREA DURING THE WEEKEND.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/MBS
NEAR TERM...JH/MBS
SHORT TERM...WP
LONG TERM...PM/RAB/WP
AVIATION...JH/MBS/RAB
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
149 PM EDT SUN MAR 13 2016
.SYNOPSIS...
A NEARLY STATIONARY FRONT EXTENDS FROM THE LOWER MISSOURI VALLEY
EAST TO SOUTHWEST VIRGINIA THIS AFTERNOON. BY MONDAY MORNING THE
LOW WILL BE ENTERING THE TENNESSEE VALLEY WITH THE WARM FRONT
ACROSS THE OHIO VALLEY AND MID ATLANTIC STATES. WEAK HIGH PRESSURE
WILL FOLLOW THIS SYSTEM FOR TUESDAY BEFORE A COLD FRONT ARRIVES
RESULTING IN COOLER WEATHER WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 125 PM EDT SUNDAY...
BAND OF LIGHT TO MODERATE SHOWERS MOVING ACROSS THE MTNS EARLY
THIS AFTERNOON. STILL EXPECTING A COVERAGE OF LIKELY POPS...I.E
NUMEROUS SHOWERS THROUGH LATE AFTERNOON. UPPED TEMPS IN FAR SE AS
SOME PEAKS OF SUNSHINE POSSIBLE...AND TEMPS AT DANVILLE ALREADY IN
THE LOWER 70S.
PREVIOUS MID MORNING DISCUSSION....
EXPECT A SLOWER SOLUTION TO RAINFALL MOVING IN THIS MORNING.
RADAR SHOWS SOME 35 TO 40 DBZ REFLECTIVITY OVER THE NC MTNS AS OF
1320Z/0920 EDT. ALTHOUGH OBSERVATIONS INDICATE LIGHT RAIN/DRIZZLE.
LOWERED POPS THROUGH THE MORNING TO LINE UP WITH RADAR AND
FOLLOWING CLOSER TO THE 00Z HIRESW-ARW. STILL LOOKS LIKE MORE
SHOWERS THIS AFTERNOON. CLOUD COVER LOOKS SOLID SO NOT EXPECTING
MUCH BREAKS. THIS WILL LIMIT INSTABILITY AND MORNING SOUNDINGS
INDICATE THE TEMPS NEED TO GET INTO THE MID 70S FOR THUNDER.
STILL ISOLATED STORMS POSSIBLE OVER THE SRN TIER OF THE CWA.
PREVIOUS MORNING DISCUSSION...
CHALLENGING TO NARROW DOWN MOST FAVORED TIMING OF PRECIPITATION
TODAY AND TONIGHT DUE TO MULTIPLE FACTORS THAT WILL INFLUENCE THE
LOCATION OF BEST LIFT. STARTING OFF WITH SOME DRY AIR AT MID
LEVELS BUT MOISTURE WILL INCREASE THROUGHOUT THE DAY WITH
PRECIPITABLE WATER VALUES CLOSING IN ON 1.5 INCHES IN THE EASTERN
COUNTY WARNING AREA. MAIN SHORT WAVE OVER THE TENNESSEE VALLEY
WILL CONTINUE MOVING NORTH INTO THE GREAT LAKES BUT WEAKER PIECES
OF ENERGY WILL TRACK THROUGH THE SOUTHWEST FLOW ALOFT INTO THE MID
ATLANTIC REGION.
AT THE SURFACE A WARM FRONT EXTENDED FROM NORTHEAST NORTH
CAROLINA INTO SOUTHERN WEST VIRGINIA. BY THE END OF THE DAY THIS
BOUNDARY IS EXPECTED TO BE JUST NORTHEAST OF THE FORECAST AREA.
RADAR SHOWED WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS OVER
THE TENNESSEE AND OHIO VALLEYS EARLY THIS MORNING. THE LEADING
EDGE OF THIS PRECIPITATION WILL MOVE NORTHEAST TODAY. HRRR...LOCAL
WRF AND RAP GUIDANCE...AMONG OTHER EACH HAD SLIGHTLY DIFFERENT
SOLUTIONS WITH THE TIMING OF THE SHOWERS. OVERALL CONSENSUS WAS TO
BRING A BAND OF SHOWERS FROM SOUTHWEST TO NORTHEAST ACROSS THE
FORECAST AREA BETWEEN 15Z/11AM AND 03Z/11PM. HAVE INCREASED THE
PROBABILITY OF PRECIPITATION DURING THIS TIME FRAME BUT STILL KEPT
LOWER CHANCES FOR THIS MORNING.
BUFKIT FORECAST SOUNDINGS SHOWED SOME ELEVATED INSTABILITY THIS
MORNING WITH MOST UNSTABLE CAPES AS HIGH AS 500 J/KG OVER THE
SOUTHERN COUNTY WARNING AREA THIS AFTERNOON. SOME GUIDANCE
SUGGESTED ONE BAND OF PRECIPITATION THIS MORNING FOLLOWED BY
ENOUGH CLEARING TO INCREASE THE INSTABILITY...THEN ANOTHER BATCH
OF SHOWERS AND ISOLATED THUNDERSTORMS THIS AFTERNOON. CONFIDENCE
IN THIS SCENARIO WAS NOT HIGH ENOUGH AT THIS TIME. CONFIDENCE ID
HIGHER FOR THE BEST PROBABILITY OF PRECIPITATION WHEREVER THIS
AREA OF SHOWERS INTERSECTS THE WARM FRONT.
TEMPERATURES WILL START OUT TODAY IN THE MID 50S TO LOWER 60S.
KEPT MAXIMUM TEMPERATURES ABOVE GUIDANCE. SIMILAR TO
SATURDAY...ANY BREAKS IN THE CLOUD COVER WILL MEAN TEMPERATURES
WILL SPIKE UP.
BY LATE TONIGHT SURFACE LOW PRESSURE DEVELOPS ALONG THE WARM FRONT
OVER THE MID ATLANTIC COAST. IN RESPONSE THE WINDS IN THE
NORTHEAST COUNTY WARNING AREA TO THE NORTHEAST AND RELATIVELY
COOLER AND MORE STABLE AIR GETS PUSHED INTO THE VIRGINIA PIEDMONT.
HAVE LOW TEMPERATURES NORTH OF THE FRONT...EAST OF THE BLUE RIDGE
AT LEAST AS FAR SOUTH AS 460 CLOSER TO THE COOLER MET GUIDANCE.
HAVE MILDER TEMPERATURES ACROSS THE SOUTH. BUFKIT SUGGESTS VERY
SHALLOW LAYER OF COOLER AIR AND THE NORTHEAST WINDS MAY ADVANCE
ALL THE WAY INTO THE NEW RIVER VALLEY.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 430 AM EDT SUNDAY...
A DRY SLOT IN BETWEEN SYSTEMS SHOULD PUSH OVER THE CWA ON MONDAY
MORNING. LAPSE RATES SHOULD STEEPEN AS A COOL POOL OF AIR ALOFT
ARRIVES FROM A COMPACT UPPER LEVEL SHORTWAVE TROUGH TRACKING
EAST FROM TENNESSEE. SKIES MAY PARTIALLY CLEAR TO ALLOW ENOUGH
SURFACE HEATING THAT WILL BRING CAPE UP TO 1000-1500 J/KG WEST OF
THE BLUE RIDGE. A DECENT INSTABILITY GRADIENT MAY ALSO ALIGN ALONG
SOUTHSIDE VIRGINIA AND THE NORTH CAROLINA PIEDMONT. SPC STILL
ADVERTISES A MARGINAL SEVERE RISK FOR THE AFOREMENTIONED
LOCATIONS. CONVECTIVE INITIATION APPEARS LIKELY IN THE AFTERNOON
WHEN THE THERMODYNAMICS ARE MOST FAVORABLE...BUT THE BEST SYNOPTIC
LIFT DOES NOT COME UNTIL LATE IN THE EVENING. THIS MISALIGNMENT
WILL KEEP THE SEVERE THREAT ISOLATED. ELSEWHERE...LOWER CAPE
AMOUNTS ARE PROJECTED NEAR LYNCHBURG AND BUCKINGHAM DUE TO
LINGERING LOW CLOUDS IN THE MORNING...SO THIS AREA WILL HAVE THE
LOWEST CHANCE OF THUNDER.
ONCE THE CONVECTION EXITS WITH THE DEPARTING UPPER LEVEL SHORTWAVE
TROUGH AFTER MIDNIGHT...THE REMAINING RAINFALL WILL BE CONFINED TO
THE HIGHER ELEVATIONS IN SOUTHEAST WEST VIRGINIA BY TUESDAY MORNING.
THAT MOISTURE SHOULD FADE DURING THE DAY AS DRIER AIR ARRIVES AND
SKIES CLEAR TO ALLOW HIGH TEMPERATURES ON TUESDAY TO REACH WELL INTO
THE 60S AND 70S. UPPER LEVEL RIDGING BECOMES MORE PROMINENT DURING
TUESDAY NIGHT AND WEDNESDAY IN RESPONSE TO A DIGGING UPPER LEVEL
TROUGH UPSTREAM OVER THE NORTHERN PLAINS. THE LOW PRESSURE SYSTEM
ASSOCIATED WITH THIS TROUGH COULD SPREAD A THIN LAYER OF MOISTURE
OVER THE WESTERN SLOPES FROM WATAUGA THROUGH GREENBRIER COUNTIES.
SO...LOW CHANCE POPS FOR SHOWERS WERE PLACED IN THIS AREA DURING
WEDNESDAY. MOST LOCATIONS SHOULD SEE HIGH TEMPERATURES SOARING INTO
THE 70S...WITH EVEN LOWER 80S POSSIBLE AT DANVILLE.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
AS OF 400 PM EST SATURDAY...
VIGOROUS MID-LEVEL ENERGY DIGGING INTO THE NORTH CENTRAL CONUS FOR
MID WEEK WILL BE THE MAIN WEATHER FOCUS FOR THE LATER HALF OF THE
WEEK AS IT TRANSITIONS INTO A DEEP VORTEX NEAR THE GREAT LAKES
REGION. THE ACCOMPANYING SURFACE FRONT WILL PROGRESS EASTWARD OUT
OF THE MISSISSIPPI VALLEY BEFORE PUSHING OFF THE EASTERN
SEABOARD THURSDAY....WITH THE TAIL END OF THE BOUNDARY EXPECTED
TO LINGER OVER THE SOUTHEAST AND NORTHERN GULF OF MEXICO.
UPSTREAM...SHORTWAVE ENERGY STREAKING OUT OF BRITISH COLUMBIA ON
THURSDAY MAY CAUSE FLOW TO AMPLIFY BY THE END OF THE WEEK WITH
POTENTIAL FOR SFC LOW PRESSURE TO FORM ALONG OLD FRONTAL BOUNDARY
OVER THE SOUTHEAST STATES. STILL TO EARLY TO TELL WHERE THIS
FEATURE MAY TRACK...BUT IT DOES SUGGEST NEXT WEEKEND MAY BE CLOUDY
AND WET FOR THE MID ATLANTIC.
ABOVE SEASONAL WARMTH WILL PEAK MID WEEK PRIOR TO THE ARRIVAL OF
THE FRONT. PASSAGE OF THE FRONT WILL THEN BRING MUCH COOLER
WEATHER TO THE MID ATLANTIC FOR THE LATER HALF OF THE WEEK WITH
TEMPERATURES TRENDING BACK TO NORMAL OR EVEN BELOW NORMAL FOR NEXT
WEEKEND.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
AS OF 140 PM EDT SUNDAY...
EXPECT CIGS TO LOWER TO UNDER VFR THIS AFTERNOON AS RAIN SHOWERS
MOVING FROM SW TO NE ACT TO MOISTEN THE LOW LVLS. AT
TIMES...VSBYS MAY SINK TO MVFR/IFR WITH MODERATE SHOWERS.
FOLLOWED THE RAP/NAM AND SREF SHOWING SOME BREAKS IN THE SHOWERS
LATE THIS AFTERNOON/EVENING AND DRYING OUT BY MIDNIGHT. THESE
MODELS ARE HIGHLIGHTING A WEAK WEDGE AND STRATUS/FOG ISSUES
OVERNIGHT AT ALL SITES. QUESTION IS HOW LOW WILL STRATUS GET VS
FOG DENSITY. PLAYED IT CONSERVATIVE THOUGH WILL MAKE MOST SITES
IFR WITH SUB 1KFT CIGS.
THE QUESTION THEN IS HOW FAST WILL THIS LOW LVL MOISTURE SCOUR OUT
MONDAY MORNING. SHOULD SEE THE SW BLF/BCB POTENTIALLY GOING VFR BY
18Z...WITH THE REST OF THE CWA STAYING MVFR.
CONFIDENCE IS MEDIUM IN CIG/VSBY IFR VS MVFR MAINLY AFTER 23Z
TODAY THROUGH 18Z MONDAY...BUT HIGH IN SUB VFR CONDITIONS THROUGH
MUCH OF THE PERIOD.
EXTENDED DISCUSSION...
WILL SEE ANOTHER UPPER DISTURBANCE PASS TO THE NORTHWEST MONDAY
WITH A TRAILING TROUGH AXIS CROSSING THE REGION. AFTER INTERVALS
OF VFR EARLY MONDAY AFTERNOON...SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS ARE EXPECTED BY MID AFTERNOON RESULTING IN PERIODS
OF MVFR/IFR IN LOW CIGS/RAINFALL. THE ENVIRONMENT MAY BE FAVORABLE
FOR HAIL WITH ANY OF THE STRONGER STORMS...ESPECIALLY SOUTH OF
BLF-BCB-LYH LINE.
TUESDAY WILL FIND US BETWEEN SYSTEMS SO SOME IMPROVEMENT TO MAINLY
VFR EXPECTED. NEXT COLD FRONT APPROACHES FROM THE NORTHWEST
WEDNESDAY WITH PERHAPS A FEW SHOWERS...INCLUDING A PERIOD OF MVFR
IN THE MOUNTAINS.
SHOULD RETURN TO VFR POST FRONTAL THURSDAY EXCEPT LINGERING MVFR
POSSIBLE KLWB/KBLF...WITH FRIDAY VFR WITH HIGH PRESSURE IN
CONTROL.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/WP
SHORT TERM...PW
LONG TERM...PM
AVIATION...AMS/JH/WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
945 AM EDT SUN MAR 13 2016
.SYNOPSIS...
A WARM FRONT WITH MULTIPLE LOWS EXTENDED FROM OKLAHOMA TO VIRGINIA THIS
MORNING. BY MONDAY MORNING THE PRIMARY LOW WILL BE ENTERING THE
TENNESSEE VALLEY WITH THE WARM FRONT ACROSS THE OHIO VALLEY AND
MID ATLANTIC STATES. WEAK HIGH PRESSURE WILL FOLLOW THIS SYSTEM
FOR TUESDAY BEFORE A COLD FRONT ARRIVES RESULTING IN COOLER
WEATHER WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 925 AM EDT SUNDAY...
EXPECT A SLOWER SOLUTION TO RAINFALL MOVING IN THIS MORNING. RADAR
SHOWS SOME 35 TO 40 DBZ REFLECTIVITY OVER THE NC MTNS AS OF
1320Z/0920 EDT. ALTHOUGH OBSERVATIONS INDICATE LIGHT RAIN/DRIZZLE.
LOWERED POPS THROUGH THE MORNING TO LINE UP WITH RADAR AND
FOLLOWING CLOSER TO THE 00Z HIRESW-ARW. STILL LOOKS LIKE MORE
SHOWERS THIS AFTERNOON. CLOUD COVER LOOKS SOLID SO NOT EXPECTING
MUCH BREAKS. THIS WILL LIMIT INSTABILITY AND MORNING SOUNDINGS
INDICATE THE TEMPS NEED TO GET INTO THE MID 70S FOR THUNDER.
STILL ISOLATED STORMS POSSIBLE OVER THE SRN TIER OF THE CWA.
PREVIOUS MORNING DISCUSSION...
CHALLENGING TO NARROW DOWN MOST FAVORED TIMING OF PRECIPITATION
TODAY AND TONIGHT DUE TO MULTIPLE FACTORS THAT WILL INFLUENCE THE
LOCATION OF BEST LIFT. STARTING OFF WITH SOME DRY AIR AT MID
LEVELS BUT MOISTURE WILL INCREASE THROUGHOUT THE DAY WITH
PRECIPITABLE WATER VALUES CLOSING IN ON 1.5 INCHES IN THE EASTERN
COUNTY WARNING AREA. MAIN SHORT WAVE OVER THE TENNESSEE VALLEY
WILL CONTINUE MOVING NORTH INTO THE GREAT LAKES BUT WEAKER PIECES
OF ENERGY WILL TRACK THROUGH THE SOUTHWEST FLOW ALOFT INTO THE MID
ATLANTIC REGION.
AT THE SURFACE A WARM FRONT EXTENDED FROM NORTHEAST NORTH
CAROLINA INTO SOUTHERN WEST VIRGINIA. BY THE END OF THE DAY THIS
BOUNDARY IS EXPECTED TO BE JUST NORTHEAST OF THE FORECAST AREA.
RADAR SHOWED WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS OVER
THE TENNESSEE AND OHIO VALLEYS EARLY THIS MORNING. THE LEADING
EDGE OF THIS PRECIPITATION WILL MOVE NORTHEAST TODAY. HRRR...LOCAL
WRF AND RAP GUIDANCE...AMONG OTHER EACH HAD SLIGHTLY DIFFERENT
SOLUTIONS WITH THE TIMING OF THE SHOWERS. OVERALL CONSENSUS WAS TO
BRING A BAND OF SHOWERS FROM SOUTHWEST TO NORTHEAST ACROSS THE
FORECAST AREA BETWEEN 15Z/11AM AND 03Z/11PM. HAVE INCREASED THE
PROBABILITY OF PRECIPITATION DURING THIS TIME FRAME BUT STILL KEPT
LOWER CHANCES FOR THIS MORNING.
BUFKIT FORECAST SOUNDINGS SHOWED SOME ELEVATED INSTABILITY THIS
MORNING WITH MOST UNSTABLE CAPES AS HIGH AS 500 J/KG OVER THE
SOUTHERN COUNTY WARNING AREA THIS AFTERNOON. SOME GUIDANCE
SUGGESTED ONE BAND OF PRECIPITATION THIS MORNING FOLLOWED BY
ENOUGH CLEARING TO INCREASE THE INSTABILITY...THEN ANOTHER BATCH
OF SHOWERS AND ISOLATED THUNDERSTORMS THIS AFTERNOON. CONFIDENCE
IN THIS SCENARIO WAS NOT HIGH ENOUGH AT THIS TIME. CONFIDENCE ID
HIGHER FOR THE BEST PROBABILITY OF PRECIPITATION WHEREVER THIS
AREA OF SHOWERS INTERSECTS THE WARM FRONT.
TEMPERATURES WILL START OUT TODAY IN THE MID 50S TO LOWER 60S.
KEPT MAXIMUM TEMPERATURES ABOVE GUIDANCE. SIMILAR TO
SATURDAY...ANY BREAKS IN THE CLOUD COVER WILL MEAN TEMPERATURES
WILL SPIKE UP.
BY LATE TONIGHT SURFACE LOW PRESSURE DEVELOPS ALONG THE WARM FRONT
OVER THE MID ATLANTIC COAST. IN RESPONSE THE WINDS IN THE
NORTHEAST COUNTY WARNING AREA TO THE NORTHEAST AND RELATIVELY
COOLER AND MORE STABLE AIR GETS PUSHED INTO THE VIRGINIA PIEDMONT.
HAVE LOW TEMPERATURES NORTH OF THE FRONT...EAST OF THE BLUE RIDGE
AT LEAST AS FAR SOUTH AS 460 CLOSER TO THE COOLER MET GUIDANCE.
HAVE MILDER TEMPERATURES ACROSS THE SOUTH. BUFKIT SUGGESTS VERY
SHALLOW LAYER OF COOLER AIR AND THE NORTHEAST WINDS MAY ADVANCE
ALL THE WAY INTO THE NEW RIVER VALLEY.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 430 AM EDT SUNDAY...
A DRY SLOT IN BETWEEN SYSTEMS SHOULD PUSH OVER THE CWA ON MONDAY
MORNING. LAPSE RATES SHOULD STEEPEN AS A COOL POOL OF AIR ALOFT
ARRIVES FROM A COMPACT UPPER LEVEL SHORTWAVE TROUGH TRACKING
EAST FROM TENNESSEE. SKIES MAY PARTIALLY CLEAR TO ALLOW ENOUGH
SURFACE HEATING THAT WILL BRING CAPE UP TO 1000-1500 J/KG WEST OF
THE BLUE RIDGE. A DECENT INSTABILITY GRADIENT MAY ALSO ALIGN ALONG
SOUTHSIDE VIRGINIA AND THE NORTH CAROLINA PIEDMONT. SPC STILL
ADVERTISES A MARGINAL SEVERE RISK FOR THE AFOREMENTIONED
LOCATIONS. CONVECTIVE INITIATION APPEARS LIKELY IN THE AFTERNOON
WHEN THE THERMODYNAMICS ARE MOST FAVORABLE...BUT THE BEST SYNOPTIC
LIFT DOES NOT COME UNTIL LATE IN THE EVENING. THIS MISALIGNMENT
WILL KEEP THE SEVERE THREAT ISOLATED. ELSEWHERE...LOWER CAPE
AMOUNTS ARE PROJECTED NEAR LYNCHBURG AND BUCKINGHAM DUE TO
LINGERING LOW CLOUDS IN THE MORNING...SO THIS AREA WILL HAVE THE
LOWEST CHANCE OF THUNDER.
ONCE THE CONVECTION EXITS WITH THE DEPARTING UPPER LEVEL SHORTWAVE
TROUGH AFTER MIDNIGHT...THE REMAINING RAINFALL WILL BE CONFINED TO
THE HIGHER ELEVATIONS IN SOUTHEAST WEST VIRGINIA BY TUESDAY MORNING.
THAT MOISTURE SHOULD FADE DURING THE DAY AS DRIER AIR ARRIVES AND
SKIES CLEAR TO ALLOW HIGH TEMPERATURES ON TUESDAY TO REACH WELL INTO
THE 60S AND 70S. UPPER LEVEL RIDGING BECOMES MORE PROMINENT DURING
TUESDAY NIGHT AND WEDNESDAY IN RESPONSE TO A DIGGING UPPER LEVEL
TROUGH UPSTREAM OVER THE NORTHERN PLAINS. THE LOW PRESSURE SYSTEM
ASSOCIATED WITH THIS TROUGH COULD SPREAD A THIN LAYER OF MOISTURE
OVER THE WESTERN SLOPES FROM WATAUGA THROUGH GREENBRIER COUNTIES.
SO...LOW CHANCE POPS FOR SHOWERS WERE PLACED IN THIS AREA DURING
WEDNESDAY. MOST LOCATIONS SHOULD SEE HIGH TEMPERATURES SOARING INTO
THE 70S...WITH EVEN LOWER 80S POSSIBLE AT DANVILLE.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
AS OF 400 PM EST SATURDAY...
VIGOROUS MID-LEVEL ENERGY DIGGING INTO THE NORTH CENTRAL CONUS FOR
MID WEEK WILL BE THE MAIN WEATHER FOCUS FOR THE LATER HALF OF THE
WEEK AS IT TRANSITIONS INTO A DEEP VORTEX NEAR THE GREAT LAKES
REGION. THE ACCOMPANYING SURFACE FRONT WILL PROGRESS EASTWARD OUT
OF THE MISSISSIPPI VALLEY BEFORE PUSHING OFF THE EASTERN
SEABOARD THURSDAY....WITH THE TAIL END OF THE BOUNDARY EXPECTED
TO LINGER OVER THE SOUTHEAST AND NORTHERN GULF OF MEXICO.
UPSTREAM...SHORTWAVE ENERGY STREAKING OUT OF BRITISH COLUMBIA ON
THURSDAY MAY CAUSE FLOW TO AMPLIFY BY THE END OF THE WEEK WITH
POTENTIAL FOR SFC LOW PRESSURE TO FORM ALONG OLD FRONTAL BOUNDARY
OVER THE SOUTHEAST STATES. STILL TO EARLY TO TELL WHERE THIS
FEATURE MAY TRACK...BUT IT DOES SUGGEST NEXT WEEKEND MAY BE CLOUDY
AND WET FOR THE MID ATLANTIC.
ABOVE SEASONAL WARMTH WILL PEAK MID WEEK PRIOR TO THE ARRIVAL OF
THE FRONT. PASSAGE OF THE FRONT WILL THEN BRING MUCH COOLER
WEATHER TO THE MID ATLANTIC FOR THE LATER HALF OF THE WEEK WITH
TEMPERATURES TRENDING BACK TO NORMAL OR EVEN BELOW NORMAL FOR NEXT
WEEKEND.
&&
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
AS OF 0735 AM EDT SUNDAY...
DISTURBANCE ACROSS THE MISSISSIPPI VALLEY WILL LIFT NORTHEAST
TODAY AND TONIGHT BRINGING A BROAD AREA OF DEEP MOISTURE AND
NUMEROUS SHOWERS. A MAJORITY OF THE PRECIPITATION WILL OCCUR FROM
15Z/11AM THROUGH 03Z/11PM. CEILINGS WILL LOWER TO VFR THEN MVFR AS
THE SHOWERS SPREAD ACROSS THE AREA. SOME THUNDER POSSIBLE MAINLY
ACROSS THE SOUTH THIS AFTERNOON. BUT PROBABILITY WAS TOO LOW TO
INCLUDE IN THE TAFS FOR NOW.
TONIGHT BOUNDARY ENDS UP ACROSS THE FORECAST AREA WITH A NORTHEAST
WIND AT LYNCHBURG AND MORE STABLE AIR NORTH OF THE FRONT.
CONFIDENCE LOW ON THE WIND DIRECTION OVERNIGHT. AFTER THE SHOWERS
TODAY AND TONIGHT...ABUNDANT LOW LEVEL MOISTURE AND LIGHT WINDS
WILL RESULT IN STRATUS AND FOG AFTER MIDNIGHT. MEDIUM TO HIGH
CONFIDENCE OF IFR TO LIFR CEILINGS.
EXTENDED DISCUSSION...
WILL SEE ANOTHER UPPER DISTURBANCE PASS TO THE NORTHWEST MONDAY
WITH A TRAILING TROUGH AXIS CROSSING THE REGION. AFTER INTERVALS
OF VFR MONDAY MORNING...SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS ARE EXPECTED IN THE AFTERNOON RESULTING IN PERIODS
OF MVFR/IFR IN LOW CIGS/RAINFALL. THE ENVIRONMENT MAY BE FAVORABLE
FOR HAIL WITH ANY OF THE STRONGER STORMS.
TUESDAY WILL FIND US BETWEEN SYSTEMS SO SOME IMPROVEMENT TO MAINLY
VFR EXPECTED. NEXT COLD FRONT APPROACHES FROM THE NORTHWEST
WEDNESDAY WITH PERHAPS A FEW SHOWERS...INCLUDING A PERIOD OF MVFR
IN THE MOUNTAINS.
SHOULD RETURN TO VFR POST FRONTAL THURSDAY EXCEPT LINGERING MVFR
POSSIBLE KLWB/KBLF.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/WP
SHORT TERM...PW
LONG TERM...PM
AVIATION...AMS/JH
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
741 AM EDT SUN MAR 13 2016
.SYNOPSIS...
A WARM FRONT WITH MULTIPLE LOWS EXTENDED FROM OKLAHOMA TO VIRGINIA THIS
MORNING. BY MONDAY MORNING THE PRIMARY LOW WILL BE ENTERING THE
TENNESSEE VALLEY WITH THE WARM FRONT ACROSS THE OHIO VALLEY AND
MID ATLANTIC STATES. WEAK HIGH PRESSURE WILL FOLLOW THIS SYSTEM
FOR TUESDAY BEFORE A COLD FRONT ARRIVES RESULTING IN COOLER
WEATHER WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 425 PM EDT SUNDAY...
CHALLENGING TO NARROW DOWN MOST FAVORED TIMING OF PRECIPITATION
TODAY AND TONIGHT DUE TO MULTIPLE FACTORS THAT WILL INFLUENCE THE
LOCATION OF BEST LIFT. STARTING OFF WITH SOME DRY AIR AT MID
LEVELS BUT MOISTURE WILL INCREASE THROUGHOUT THE DAY WITH
PRECIPITABLE WATER VALUES CLOSING IN ON 1.5 INCHES IN THE EASTERN
COUNTY WARNING AREA. MAIN SHORT WAVE OVER THE TENNESSEE VALLEY
WILL CONTINUE MOVING NORTH INTO THE GREAT LAKES BUT WEAKER PIECES
OF ENERGY WILL TRACK THROUGH THE SOUTHWEST FLOW ALOFT INTO THE MID
ATLANTIC REGION.
AT THE SURFACE A WARM FRONT EXTENDED FROM NORTHEAST NORTH
CAROLINA INTO SOUTHERN WEST VIRGINIA. BY THE END OF THE DAY THIS
BOUNDARY IS EXPECTED TO BE JUST NORTHEAST OF THE FORECAST AREA.
RADAR SHOWED WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS OVER
THE TENNESSEE AND OHIO VALLEYS EARLY THIS MORNING. THE LEADING
EDGE OF THIS PRECIPITATION WILL MOVE NORTHEAST TODAY. HRRR...LOCAL
WRF AND RAP GUIDANCE...AMONG OTHER EACH HAD SLIGHTLY DIFFERENT
SOLUTIONS WITH THE TIMING OF THE SHOWERS. OVERALL CONSENSUS WAS TO
BRING A BAND OF SHOWERS FROM SOUTHWEST TO NORTHEAST ACROSS THE
FORECAST AREA BETWEEN 15Z/11AM AND 03Z/11PM. HAVE INCREASED THE
PROBABILITY OF PRECIPITATION DURING THIS TIME FRAME BUT STILL KEPT
LOWER CHANCES FOR THIS MORNING.
BUFKIT FORECAST SOUNDINGS SHOWED SOME ELEVATED INSTABILITY THIS
MORNING WITH MOST UNSTABLE CAPES AS HIGH AS 500 J/KG OVER THE
SOUTHERN COUNTY WARNING AREA THIS AFTERNOON. SOME GUIDANCE
SUGGESTED ONE BAND OF PRECIPITATION THIS MORNING FOLLOWED BY
ENOUGH CLEARING TO INCREASE THE INSTABILITY...THEN ANOTHER BATCH
OF SHOWERS AND ISOLATED THUNDERSTORMS THIS AFTERNOON. CONFIDENCE
IN THIS SCENARIO WAS NOT HIGH ENOUGH AT THIS TIME. CONFIDENCE ID
HIGHER FOR THE BEST PROBABILITY OF PRECIPITATION WHEREVER THIS
AREA OF SHOWERS INTERSECTS THE WARM FRONT.
TEMPERATURES WILL START OUT TODAY IN THE MID 50S TO LOWER 60S.
KEPT MAXIMUM TEMPERATURES ABOVE GUIDANCE. SIMILAR TO
SATURDAY...ANY BREAKS IN THE CLOUD COVER WILL MEAN TEMPERATURES
WILL SPIKE UP.
BY LATE TONIGHT SURFACE LOW PRESSURE DEVELOPS ALONG THE WARM FRONT
OVER THE MID ATLANTIC COAST. IN RESPONSE THE WINDS IN THE
NORTHEAST COUNTY WARNING AREA TO THE NORTHEAST AND RELATIVELY
COOLER AND MORE STABLE AIR GETS PUSHED INTO THE VIRGINIA PIEDMONT.
HAVE LOW TEMPERATURES NORTH OF THE FRONT...EAST OF THE BLUE RIDGE
AT LEAST AS FAR SOUTH AS 460 CLOSER TO THE COOLER MET GUIDANCE.
HAVE MILDER TEMPERATURES ACROSS THE SOUTH. BUFKIT SUGGESTS VERY
SHALLOW LAYER OF COOLER AIR AND THE NORTHEAST WINDS MAY ADVANCE
ALL THE WAY INTO THE NEW RIVER VALLEY.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 430 AM EDT SUNDAY...
A DRY SLOT IN BETWEEN SYSTEMS SHOULD PUSH OVER THE CWA ON MONDAY
MORNING. LAPSE RATES SHOULD STEEPEN AS A COOL POOL OF AIR ALOFT
ARRIVES FROM A COMPACT UPPER LEVEL SHORTWAVE TROUGH TRACKING
EAST FROM TENNESSEE. SKIES MAY PARTIALLY CLEAR TO ALLOW ENOUGH
SURFACE HEATING THAT WILL BRING CAPE UP TO 1000-1500 J/KG WEST OF
THE BLUE RIDGE. A DECENT INSTABILITY GRADIENT MAY ALSO ALIGN ALONG
SOUTHSIDE VIRGINIA AND THE NORTH CAROLINA PIEDMONT. SPC STILL
ADVERTISES A MARGINAL SEVERE RISK FOR THE AFOREMENTIONED
LOCATIONS. CONVECTIVE INITIATION APPEARS LIKELY IN THE AFTERNOON
WHEN THE THERMODYNAMICS ARE MOST FAVORABLE...BUT THE BEST SYNOPTIC
LIFT DOES NOT COME UNTIL LATE IN THE EVENING. THIS MISALIGNMENT
WILL KEEP THE SEVERE THREAT ISOLATED. ELSEWHERE...LOWER CAPE
AMOUNTS ARE PROJECTED NEAR LYNCHBURG AND BUCKINGHAM DUE TO
LINGERING LOW CLOUDS IN THE MORNING...SO THIS AREA WILL HAVE THE
LOWEST CHANCE OF THUNDER.
ONCE THE CONVECTION EXITS WITH THE DEPARTING UPPER LEVEL SHORTWAVE
TROUGH AFTER MIDNIGHT...THE REMAINING RAINFALL WILL BE CONFINED TO
THE HIGHER ELEVATIONS IN SOUTHEAST WEST VIRGINIA BY TUESDAY MORNING.
THAT MOISTURE SHOULD FADE DURING THE DAY AS DRIER AIR ARRIVES AND
SKIES CLEAR TO ALLOW HIGH TEMPERATURES ON TUESDAY TO REACH WELL INTO
THE 60S AND 70S. UPPER LEVEL RIDGING BECOMES MORE PROMINENT DURING
TUESDAY NIGHT AND WEDNESDAY IN RESPONSE TO A DIGGING UPPER LEVEL
TROUGH UPSTREAM OVER THE NORTHERN PLAINS. THE LOW PRESSURE SYSTEM
ASSOCIATED WITH THIS TROUGH COULD SPREAD A THIN LAYER OF MOISTURE
OVER THE WESTERN SLOPES FROM WATAUGA THROUGH GREENBRIER COUNTIES.
SO...LOW CHANCE POPS FOR SHOWERS WERE PLACED IN THIS AREA DURING
WEDNESDAY. MOST LOCATIONS SHOULD SEE HIGH TEMPERATURES SOARING INTO
THE 70S...WITH EVEN LOWER 80S POSSIBLE AT DANVILLE.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
AS OF 400 PM EST SATURDAY...
VIGOROUS MID-LEVEL ENERGY DIGGING INTO THE NORTH CENTRAL CONUS FOR
MID WEEK WILL BE THE MAIN WEATHER FOCUS FOR THE LATER HALF OF THE
WEEK AS IT TRANSITIONS INTO A DEEP VORTEX NEAR THE GREAT LAKES
REGION. THE ACCOMPANYING SURFACE FRONT WILL PROGRESS EASTWARD OUT
OF THE MISSISSIPPI VALLEY BEFORE PUSHING OFF THE EASTERN
SEABOARD THURSDAY....WITH THE TAIL END OF THE BOUNDARY EXPECTED
TO LINGER OVER THE SOUTHEAST AND NORTHERN GULF OF MEXICO.
UPSTREAM...SHORTWAVE ENERGY STREAKING OUT OF BRITISH COLUMBIA ON
THURSDAY MAY CAUSE FLOW TO AMPLIFY BY THE END OF THE WEEK WITH
POTENTIAL FOR SFC LOW PRESSURE TO FORM ALONG OLD FRONTAL BOUNDARY
OVER THE SOUTHEAST STATES. STILL TO EARLY TO TELL WHERE THIS
FEATURE MAY TRACK...BUT IT DOES SUGGEST NEXT WEEKEND MAY BE CLOUDY
AND WET FOR THE MID ATLANTIC.
ABOVE SEASONAL WARMTH WILL PEAK MID WEEK PRIOR TO THE ARRIVAL OF
THE FRONT. PASSAGE OF THE FRONT WILL THEN BRING MUCH COOLER
WEATHER TO THE MID ATLANTIC FOR THE LATER HALF OF THE WEEK WITH
TEMPERATURES TRENDING BACK TO NORMAL OR EVEN BELOW NORMAL FOR NEXT
WEEKEND.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AS OF 0735 AM EDT SUNDAY...
DISTURBANCE ACROSS THE MISSISSIPPI VALLEY WILL LIFT NORTHEAST
TODAY AND TONIGHT BRINGING A BROAD AREA OF DEEP MOISTURE AND
NUMEROUS SHOWERS. A MAJORITY OF THE PRECIPITATION WILL OCCUR FROM
15Z/11AM THROUGH 03Z/11PM. CEILINGS WILL LOWER TO VFR THEN MVFR AS
THE SHOWERS SPREAD ACROSS THE AREA. SOME THUNDER POSSIBLE MAINLY
ACROSS THE SOUTH THIS AFTERNOON. BUT PROBABILITY WAS TOO LOW TO
INCLUDE IN THE TAFS FOR NOW.
TONIGHT BOUNDARY ENDS UP ACROSS THE FORECAST AREA WITH A NORTHEAST
WIND AT LYNCHBURG AND MORE STABLE AIR NORTH OF THE FRONT.
CONFIDENCE LOW ON THE WIND DIRECTION OVERNIGHT. AFTER THE SHOWERS
TODAY AND TONIGHT...ABUNDANT LOW LEVEL MOISTURE AND LIGHT WINDS
WILL RESULT IN STRATUS AND FOG AFTER MIDNIGHT. MEDIUM TO HIGH
CONFIDENCE OF IFR TO LIFR CEILINGS.
EXTENDED DISCUSSION...
WILL SEE ANOTHER UPPER DISTURBANCE PASS TO THE NORTHWEST MONDAY
WITH A TRAILING TROUGH AXIS CROSSING THE REGION. AFTER INTERVALS
OF VFR MONDAY MORNING...SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS ARE EXPECTED IN THE AFTERNOON RESULTING IN PERIODS
OF MVFR/IFR IN LOW CIGS/RAINFALL. THE ENVIRONMENT MAY BE FAVORABLE
FOR HAIL WITH ANY OF THE STRONGER STORMS.
TUESDAY WILL FIND US BETWEEN SYSTEMS SO SOME IMPROVEMENT TO MAINLY
VFR EXPECTED. NEXT COLD FRONT APPROACHES FROM THE NORTHWEST
WEDNESDAY WITH PERHAPS A FEW SHOWERS...INCLUDING A PERIOD OF MVFR
IN THE MOUNTAINS.
SHOULD RETURN TO VFR POST FRONTAL THURSDAY EXCEPT LINGERING MVFR
POSSIBLE KLWB/KBLF.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...PW
LONG TERM...PM
AVIATION...AMS/JH
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
459 AM EDT SUN MAR 13 2016
.SYNOPSIS...
A WARM FRONT WITH MULTIPLE LOWS EXTENDED FROM OKLAHOMA TO VIRGINIATHIS
MORNING. BY MONDAY MORNING THE PRIMARY LOW WILL BE ENTERING THE
TENNESSEE VALLEY WITH THE WARM FRONT ACROSS THE OHIO VALLEY AND
MID ATLANTIC STATES. WEAK HIGH PRESSURE WILL FOLLOW THIS SYSTEM
FOR TUESDAY BEFORE A COLD FRONT ARRIVES RESULTING IN COOLER
WEATHER WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 425 PM EDT SUNDAY...
CHALLENGING TO NARROW DOWN MOST FAVORED TIMING OF PRECIPITATION
TODAY AND TONIGHT DUE TO MULTIPLE FACTORS THAT WILL INFLUENCE THE
LOCATION OF BEST LIFT. STARTING OFF WITH SOME DRY AIR AT MID
LEVELS BUT MOISTURE WILL INCREASE THROUGHOUT THE DAY WITH
PRECIPITABLE WATER VALUES CLOSING IN ON 1.5 INCHES IN THE EASTERN
COUNTY WARNING AREA. MAIN SHORT WAVE OVER THE TENNESSEE VALLEY
WILL CONTINUE MOVING NORTH INTO THE GREAT LAKES BUT WEAKER PIECES
OF ENERGY WILL TRACK THROUGH THE SOUTHWEST FLOW ALOFT INTO THE MID
ATLANTIC REGION.
AT THE SURFACE A WARM FRONT EXTENDED FROM NORTHEAST NORTH
CAROLINA INTO SOUTHERN WEST VIRGINIA. BY THE END OF THE DAY THIS
BOUNDARY IS EXPECTED TO BE JUST NORTHEAST OF THE FORECAST AREA.
RADAR SHOWED WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS OVER
THE TENNESSEE AND OHIO VALLEYS EARLY THIS MORNING. THE LEADING
EDGE OF THIS PRECIPITATION WILL MOVE NORTHEAST TODAY. HRRR...LOCAL
WRF AND RAP GUIDANCE...AMONG OTHER EACH HAD SLIGHTLY DIFFERENT
SOLUTIONS WITH THE TIMING OF THE SHOWERS. OVERALL CONSENSUS WAS TO
BRING A BAND OF SHOWERS FROM SOUTHWEST TO NORTHEAST ACROSS THE
FORECAST AREA BETWEEN 15Z/11AM AND 03Z/11PM. HAVE INCREASED THE
PROBABILITY OF PRECIPITATION DURING THIS TIME FRAME BUT STILL KEPT
LOWER CHANCES FOR THIS MORNING.
BUFKIT FORECAST SOUNDINGS SHOWED SOME ELEVATED INSTABILITY THIS
MORNING WITH MOST UNSTABLE CAPES AS HIGH AS 500 J/KG OVER THE
SOUTHERN COUNTY WARNING AREA THIS AFTERNOON. SOME GUIDANCE
SUGGESTED ONE BAND OF PRECIPITATION THIS MORNING FOLLOWED BY
ENOUGH CLEARING TO INCREASE THE INSTABILITY...THEN ANOTHER BATCH
OF SHOWERS AND ISOLATED THUNDERSTORMS THIS AFTERNOON. CONFIDENCE
IN THIS SCENARIO WAS NOT HIGH ENOUGH AT THIS TIME. CONFIDENCE ID
HIGHER FOR THE BEST PROBABILITY OF PRECIPITATION WHEREVER THIS
AREA OF SHOWERS INTERSECTS THE WARM FRONT.
TEMPERATURES WILL START OUT TODAY IN THE MID 50S TO LOWER 60S.
KEPT MAXIMUM TEMPERATURES ABOVE GUIDANCE. SIMILAR TO
SATURDAY...ANY BREAKS IN THE CLOUD COVER WILL MEAN TEMPERATURES
WILL SPIKE UP.
BY LATE TONIGHT SURFACE LOW PRESSURE DEVELOPS ALONG THE WARM FRONT
OVER THE MID ATLANTIC COAST. IN RESPONSE THE WINDS IN THE
NORTHEAST COUNTY WARNING AREA TO THE NORTHEAST AND RELATIVELY
COOLER AND MORE STABLE AIR GETS PUSHED INTO THE VIRGINIA PIEDMONT.
HAVE LOW TEMPERATURES NORTH OF THE FRONT...EAST OF THE BLUE RIDGE
AT LEAST AS FAR SOUTH AS 460 CLOSER TO THE COOLER MET GUIDANCE.
HAVE MILDER TEMPERATURES ACROSS THE SOUTH. BUFKIT SUGGESTS VERY
SHALLOW LAYER OF COOLER AIR AND THE NORTHEAST WINDS MAY ADVANCE
ALL THE WAY INTO THE NEW RIVER VALLEY.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 430 AM EDT SUNDAY...
A DRY SLOT IN BETWEEN SYSTEMS SHOULD PUSH OVER THE CWA ON MONDAY
MORNING. LAPSE RATES SHOULD STEEPEN AS A COOL POOL OF AIR ALOFT
ARRIVES FROM A COMPACT UPPER LEVEL SHORTWAVE TROUGH TRACKING
EAST FROM TENNESSEE. SKIES MAY PARTIALLY CLEAR TO ALLOW ENOUGH
SURFACE HEATING THAT WILL BRING CAPE UP TO 1000-1500 J/KG WEST OF
THE BLUE RIDGE. A DECENT INSTABILITY GRADIENT MAY ALSO ALIGN ALONG
SOUTHSIDE VIRGINIA AND THE NORTH CAROLINA PIEDMONT. SPC STILL
ADVERTISES A MARGINAL SEVERE RISK FOR THE AFOREMENTIONED
LOCATIONS. CONVECTIVE INITIATION APPEARS LIKELY IN THE AFTERNOON
WHEN THE THERMODYNAMICS ARE MOST FAVORABLE...BUT THE BEST SYNOPTIC
LIFT DOES NOT COME UNTIL LATE IN THE EVENING. THIS MISALIGNMENT
WILL KEEP THE SEVERE THREAT ISOLATED. ELSEWHERE...LOWER CAPE
AMOUNTS ARE PROJECTED NEAR LYNCHBURG AND BUCKINGHAM DUE TO
LINGERING LOW CLOUDS IN THE MORNING...SO THIS AREA WILL HAVE THE
LOWEST CHANCE OF THUNDER.
ONCE THE CONVECTION EXITS WITH THE DEPARTING UPPER LEVEL SHORTWAVE
TROUGH AFTER MIDNIGHT...THE REMAINING RAINFALL WILL BE CONFINED TO
THE HIGHER ELEVATIONS IN SOUTHEAST WEST VIRGINIA BY TUESDAY MORNING.
THAT MOISTURE SHOULD FADE DURING THE DAY AS DRIER AIR ARRIVES AND
SKIES CLEAR TO ALLOW HIGH TEMPERATURES ON TUESDAY TO REACH WELL INTO
THE 60S AND 70S. UPPER LEVEL RIDGING BECOMES MORE PROMINENT DURING
TUESDAY NIGHT AND WEDNESDAY IN RESPONSE TO A DIGGING UPPER LEVEL
TROUGH UPSTREAM OVER THE NORTHERN PLAINS. THE LOW PRESSURE SYSTEM
ASSOCIATED WITH THIS TROUGH COULD SPREAD A THIN LAYER OF MOISTURE
OVER THE WESTERN SLOPES FROM WATAUGA THROUGH GREENBRIER COUNTIES.
SO...LOW CHANCE POPS FOR SHOWERS WERE PLACED IN THIS AREA DURING
WEDNESDAY. MOST LOCATIONS SHOULD SEE HIGH TEMPERATURES SOARING INTO
THE 70S...WITH EVEN LOWER 80S POSSIBLE AT DANVILLE.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
AS OF 400 PM EST SATURDAY...
VIGOROUS MID-LEVEL ENERGY DIGGING INTO THE NORTH CENTRAL CONUS FOR
MID WEEK WILL BE THE MAIN WEATHER FOCUS FOR THE LATER HALF OF THE
WEEK AS IT TRANSITIONS INTO A DEEP VORTEX NEAR THE GREAT LAKES
REGION. THE ACCOMPANYING SURFACE FRONT WILL PROGRESS EASTWARD OUT
OF THE MISSISSIPPI VALLEY BEFORE PUSHING OFF THE EASTERN
SEABOARD THURSDAY....WITH THE TAIL END OF THE BOUNDARY EXPECTED
TO LINGER OVER THE SOUTHEAST AND NORTHERN GULF OF MEXICO.
UPSTREAM...SHORTWAVE ENERGY STREAKING OUT OF BRITISH COLUMBIA ON
THURSDAY MAY CAUSE FLOW TO AMPLIFY BY THE END OF THE WEEK WITH
POTENTIAL FOR SFC LOW PRESSURE TO FORM ALONG OLD FRONTAL BOUNDARY
OVER THE SOUTHEAST STATES. STILL TO EARLY TO TELL WHERE THIS
FEATURE MAY TRACK...BUT IT DOES SUGGEST NEXT WEEKEND MAY BE CLOUDY
AND WET FOR THE MID ATLANTIC.
ABOVE SEASONAL WARMTH WILL PEAK MID WEEK PRIOR TO THE ARRIVAL OF
THE FRONT. PASSAGE OF THE FRONT WILL THEN BRING MUCH COOLER
WEATHER TO THE MID ATLANTIC FOR THE LATER HALF OF THE WEEK WITH
TEMPERATURES TRENDING BACK TO NORMAL OR EVEN BELOW NORMAL FOR NEXT
WEEKEND.
&&
.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
AS OF 1120 PM EST SATURDAY...
DEEPER MOISTURE AGAIN REMAINS LIMITED ALONG THE WEAK STALLED FRONT
ACROSS THE REGION AND WITHIN THE RESIDUAL WEDGE THAT LINGERS TO
SOME DEGREE ALONG/EAST OF THE BLUE RIDGE. MODELS ALSO TOO MOIST
IN SHOWING REDEVELOPMENT OF LOW CLOUDS INCLUDING MVFR/IFR
CONDITIONS ALONG WITH SHOWERS INTO THE OVERNIGHT. THUS TRENDING
MORE VFR UNTIL THE EARLY MORNING HOURS AT THIS POINT.
GUIDANCE AGAIN WANTING TO FLOP THE WEDGE BACK ACROSS MUCH OF THE
REGION OVERNIGHT AS THE AXIS OF DEEPER MOISTURE TO THE WEST EDGES
CLOSER LATE. THIS LOOKS ON TRACK BY DAYBREAK SUNDAY WITH PERHAPS A
BAND OF SHOWERS NEARING THE KBLF VICINITY AS WELL BY EARLY IN THE
MORNING. THUS FOLLOWED CLOSER TO THE LATEST LAV GUIDANCE IN
DELAYING THE ONSET OF MVFR CIGS UNTIL AFTER MIDNIGHT MOST
SITES...WITH POSSIBLE IFR AROUND KBLF AND ALONG THE BLUE RIDGE.
APPEARS A SIMILAR SCENARIO REGARDING FOG WITH VSBY RESTRICTIONS
LIKELY DUE MORE TO A LOWERING OF THE STRATUS DECK ALONG THE RIDGES
VS RADIATIVE NATURE GIVEN CLOUD COVER EXCLUDING PERHAPS KDAN/KLYH
LATE WHERE SOME PATCHY MVFR TO IFR FOG POSSIBLE.
DISTURBANCE ACROSS THE MISSISSIPPI VALLEY WILL LIFT BY TO THE WEST
SUNDAY INTO SUNDAY NIGHT BRINGING A BROAD AREA OF DEEP MOISTURE
ACROSS THE REGION BY SUNDAY AFTERNOON...WITH SHOWERS CONTINUING
INTO MUCH OF SUNDAY NIGHT. ALTHOUGH COVERAGE LOOKS RATHER
WIDESPREAD WITHIN THE MOISTURE CANOPY...INTENSITY LIKELY CONFINED
TO BANDS OF EMBEDDED HEAVIER SHOWERS WITH SOME THUNDER POSSIBLE
MAINLY EAST LATER SUNDAY. FOR NOW GIVEN LIMITED INSTABILITY AND A
RATHER SATURATED ENVIRONMENT...WILL LEAVE OUT ANY TSRA MENTION
WHILE INCLUDING SOME DEGREE OF MVFR IN SHOWERS FOR MOST SITES
AFTER A BRIEF PERIOD OF IMPROVEMENT ESPCLY EAST SUNDAY MORNING.
EXTENDED DISCUSSION...
WILL SEE ANOTHER UPPER DISTURBANCE PASS TO THE NORTHWEST MONDAY
WITH A TRAILING TROUGH AXIS CROSSING THE REGION. AFTER INTERVALS
OF VFR MONDAY MORNING...SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS ARE EXPECTED IN THE AFTERNOON RESULTING IN PERIODS
OF MVFR/IFR IN LOW CIGS/RAINFALL. THE ENVIRONMENT MAY BE FAVORABLE
FOR HAIL WITH ANY OF THE STRONGER STORMS.
TUESDAY WILL FIND US BETWEEN SYSTEMS SO SOME IMPROVEMENT TO MAINLY
VFR EXPECTED. NEXT COLD FRONT APPROACHES FROM THE NORTHWEST
WEDNESDAY WITH PERHAPS A FEW SHOWERS...INCLUDING A PERIOD OF MVFR
IN THE MOUNTAINS.
SHOULD RETURN TO VFR POST FRONTAL THURSDAY EXCEPT LINGERING MVFR
POSSIBLE KLWB/KBLF.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...PW
LONG TERM...PM
AVIATION...AMS/JH/WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1133 PM EST SAT MAR 12 2016
.SYNOPSIS...
HIGH PRESSURE OFFSHORE WILL CONTINUE TO SHIFT EAST OVERNIGHT
AHEAD OF WEAK LOW PRESSURE THAT WILL TRACK WELL TO THE WEST OF THE
REGION SUNDAY INTO SUNDAY EVENING. A SECONDARY AREA OF LOW PRESSURE
WILL PASS EAST OUT OF THE SOUTHERN PLAINS SUNDAY NIGHT AND CROSS
THE AREA LATER MONDAY INTO MONDAY NIGHT. WEAK HIGH PRESSURE WILL
FOLLOW THIS SYSTEM FOR MIDWEEK BEFORE A COLD FRONT ARRIVES
RESULTING IN COOLER WEATHER BY NEXT WEEKEND.
&&
.NEAR TERM /THROUGH SUNDAY/...
AS OF 820 PM EST SATURDAY...
WEAK SURFACE FRONT REMAINS DRAPED ACROSS THE SOUTHERN HALF OF THE
AREA THIS EVENING WITH MORE OF A WEAK WEDGE REFLECTION EAST OF THE
BLUE RIDGE NEAR THE EXITING SURFACE HIGH AND LESS OVER THE WEST.
EVENING SOUNDINGS STILL SHOW A SWATH OF MID LEVEL DRY AIR
REMAINING IN PLACE WHICH ALONG WITH LACK OF MUCH FORCING HAS KEPT
SHOWERS WEST OF THE AREA FOR THE MOST PART. HOWEVER WITH THE
CHANNEL OF HIGHER PWATS WEST OF THE MOUNTAINS STARTING TO EDGE
EAST...AND MESO ANALYSIS INDICATING AN AXIS OF HIGHER THETA-E JUST
TO OUR WEST...WOULD EXPECT SOME GRADUAL INCREASE IN SHOWERS FAR
WEST LATE. THIS SIMILAR TO THE LATEST HRRR OUTPUT WHICH STILL
HOLDS OFF MOST DEEP MOISTURE UNTIL AROUND DAYBREAK GIVEN THE
LINGERING WEDGE AND MID LEVEL DRY AIR. THUS HAVE CONTINUED TO
TRIM BACK POPS OVERNIGHT WITH LITTLE MORE THAN SOME SPOTTY DRIZZLE
EAST AND MAINLY ISOLATED TO LOW CHANCE COVERAGE MOUNTAINS.
OTHERWISE EXPECT CLOUDS TO GRADUALLY FILL BACK IN BUT OVERALL PC
EAST TO MOSTLY CLOUDY MOUNTAINS. RAISED LOW TEMPS A CATEGORY IN
SPOTS WEST WHERE OUTSIDE THE WEDGE AND ALONG THE RIDGES GIVEN
MIXING. SHOULD COOL CLOSER TO GUIDANCE EAST PER LINGERING WEAK
EASTERLY TRAJECTORY AND LESS CLOUDS SO ONLY MINOR TWEAKS THERE.
PREVIOUS DISCUSSION AS OF 300 PM EST SATURDAY...
IN SITU WEDGE ERODING FAIRLY QUICKLY DESPITE US STILL BEING NORTH
OF THE FRONTAL BOUNDARY. HIGHER SUN ANGLE AND LACK OF RAINFALL IS
ALLOW FOR THIS EROSION WITH SUNSHINE BOOSTING TEMPS INTO THE MID 60S
TO LOWER 70S. EXCEPTIONS ARE SMALLER AREAS ACROSS THE BLUE RIDGE
FROM BOONE TO FANCY GAP AND ACROSS A FEW OF THE ALLEGHANYS WHERE LOW
CLOUDS REMAIN WITH TEMPS IN THE UPPER 50S TO LOWER 60S.
AGAIN RADAR REMAINS FREE OF RETURNS EARLY THIS AFTERNOON. VIS SAT
DEPICTING CU FIELDS ACROSS THE VA/NC BORDER FROM MARTINSVILLE TO
DANVILLE...AND ANOTHER AREA OVER THE MOUNTAIN EMPIRE. HIGH-RES
MODELS ARE FAVORING DEVELOPMENT MORE OVER THE FAR WEST THIS
AFTERNOON WITH ISOLATED AT BEST IN THE SRN CWA. EXPECT TO SEE
SUNSHINE REACH AS FAR NORTH AS BLUEFIELD TO DANVILLE...WITH EVEN
SOME PEAKS TOWARD ROANOKE/LYNCHBURG.
HOWEVER...AS WE GET INTO THIS EVENING THE SFC HIGH WILL BE TO OUR
EAST OFF THE NC COAST. MODELS STILL FAVORING A REFORMATION OF WEAK
IN SITU WEDGE WITH LOWER CLOUDS STRATIFYING ACROSS THE BLUE RIDGE
AND EAST. BEST LIFT WITH MOISTURE CONVERGENCE STAYS WEST OF THE
APPALACHIANS TONIGHT...BUT WILL SEE SOME SHOWERS START TO SLIDE EAST
AS UPPER RIDGE WEAKENS. BY DAWN SUNDAY WILL SEE SCATTERED SHOWERS
ACROSS THE MOUNTAINS AND POSSIBLY AS FAR EAST AS THE FOOTHILLS.
PIECES OF UPPER LEVEL VORTS WILL BEGIN TO BREAK DOWN THE UPPER RIDGE
AND SEND BETTER LIFT EASTWARD TO THE AREA SUNDAY AFTERNOON. MODELS
SHOW SOME MILD INSTABILITY IN THE AFTERNOON SO HAVE A FEW
THUNDERSTORMS MENTIONED IN THE FORECAST...GENERALLY SOUTH OF THE
HIGHWAY 460. AT THIS TIME...IT LOOKS LIKE CLOUD COVER WILL LIMIT
THIS INSTABILITY...AND WE WILL NOT SEE ANY SVR THREATS. STILL LOOKS
LIKE BY AFTERNOON MOST PLACES WILL SEE NUMEROUS SHOWERS...AND HAVE
LIKELY POPS.
WITH CLOUDS TONIGHT WENT MILD...CLOSER TO MAV/ECE MOS OR WARMER...AS
MOS HAS BEEN RUNNING TOO COOL LATELY.
FOR SUNDAY WILL SEE GOOD WAA AS THE WEDGE BREAKS QUICKLY. QUESTION
IS HOW QUICK THE SHOWERS MOVE IN AND AREAL COVERAGE. SHOULD BE MILD
WITH HIGHS IN THE MID TO UPPER 60S WEST...TO LOWER 70S EAST. IF
SUNSHINE DECIDES TO BREAK OUT FOR MORE THAN AN HOUR...COULD SEE
TEMPS JUMP ANOTHER CATEGORY TO LOWER 70S WEST TO MID TO UPPER 70S
EAST.
ALSO...DO NOT FORGET TO MOVE YOUR CLOCKS AHEAD ONE HOUR BEFORE GOING
TO BED TONIGHT.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
AS OF 400 PM EST SATURDAY...
A COMPACT SHORTWAVE TROUGH OVER THE MID MS VALLEY SUNDAY NIGHT
IS PROGGED TO TRACK EAST...PASSING OVERHEAD MONDAY AFTERNOON/EVE.
MODEST FORCING FOR ASCENT IS FORECAST ACROSS OUR AREA MONDAY
AFTERNOON WITH SBCAPE OF 1000-1500 J/KG AND LI OF M4 TO M7. AN
INCREASINGLY PRONOUNCED LOW-LEVEL BAROCLINIC ZONE IS FCST TO
BECOME ESTABLISHED ACROSS SRN OR CENTRAL VA ALONG SOUTHERN
PERIPHERY OF HIGH PRESSURE OVER NEW ENGLAND. AS DIFFERENTIAL
HEATING OCCURS THIS BOUNDARY WILL LIKELY BECOME THE FOCUS FOR
SHOWER AND THUNDERSTORM DEVELOPMENT...COMBINATION OF
COOLING/DIFFLUENCE ALOFT FROM APPROACHING SHORT WAVE RESULTING IN
STEEPENING MID LEVEL LAPSE RATES...INCREASING BOTH BOUYANCY AND
SHEAR. THIS SET- UP FAVORS RISK FOR SEVERE THUNDERSTORMS...ESP
EAST OF THE BLUE RIDGE WHERE PLUME OF SURFACE DEWPOINTS IN THE 50S
TO NEAR 60 AND TEMPERATURES IN THE U70S ARE FORECAST. PRIMARY RISK
WILL BE FROM SEVERE HAIL AND LOCALLY DAMAGING WINDS. SHEAR
PROFILES ALSO SUGGEST POTENTIAL FOR STORMS TO ROTATE WITH 0-3KM
STORM RELATIVE HELICITY FORECAST BETWEEN 150 TO 200.
WILL CONTINUE TO HIGHLIGHT SEVERE THREAT IN THE HAZARDOUS WEATHER
OUTLOOK.
LITTLE AIR MASS CHANGE IS EXPECTED FROM THE PASSAGE OF THE
SHORTWAVE TROUGH MONDAY NIGHT. AS SUCH...ANOTHER MILD DAY EXPECTED
FOR TUESDAY ALBEIT DRY. WENT ABOVE MAV MOS GUIDANCE THROUGH THE
FORECAST PERIOD. ELEVATED DEWPOINTS WILL KEEP US MILD AT NIGHT AND
COMBINATION OF HIGH SUN ANGLE WITH STRONG WARM AIR ADVECTION WILL
PROMOTE WARMER READINGS DURING THE DAY.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 400 PM EST SATURDAY...
VIGOROUS MID-LEVEL ENERGY DIGGING INTO THE NORTH CENTRAL CONUS FOR
MID WEEK WILL BE THE MAIN WEATHER FOCUS FOR THE LATER HALF OF THE
WEEK AS IT TRANSITIONS INTO A DEEP VORTEX NEAR THE GREAT LAKES
REGION. THE ACCOMPANYING SURFACE FRONT WILL PROGRESS EASTWARD OUT
OF THE MISSISSIPPI VALLEY BEFORE PUSHING OFF THE EASTERN
SEABOARD THURSDAY....WITH THE TAIL END OF THE BOUNDARY EXPECTED
TO LINGER OVER THE SOUTHEAST AND NORTHERN GULF OF MEXICO.
UPSTREAM...SHORTWAVE ENERGY STREAKING OUT OF BRITISH COLUMBIA ON
THURSDAY MAY CAUSE FLOW TO AMPLIFY BY THE END OF THE WEEK WITH
POTENTIAL FOR SFC LOW PRESSURE TO FORM ALONG OLD FRONTAL BOUNDARY
OVER THE SOUTHEAST STATES. STILL TO EARLY TO TELL WHERE THIS
FEATURE MAY TRACK...BUT IT DOES SUGGEST NEXT WEEKEND MAY BE CLOUDY
AND WET FOR THE MID ATLANTIC.
ABOVE SEASONAL WARMTH WILL PEAK MID WEEK PRIOR TO THE ARRIVAL OF
THE FRONT. PASSAGE OF THE FRONT WILL THEN BRING MUCH COOLER
WEATHER TO THE MID ATLANTIC FOR THE LATER HALF OF THE WEEK WITH
TEMPERATURES TRENDING BACK TO NORMAL OR EVEN BELOW NORMAL FOR NEXT
WEEKEND.
&&
.AVIATION /04Z SUNDAY THROUGH THURSDAY/...
AS OF 1120 PM EST SATURDAY...
DEEPER MOISTURE AGAIN REMAINS LIMITED ALONG THE WEAK STALLED FRONT
ACROSS THE REGION AND WITHIN THE RESIDUAL WEDGE THAT LINGERS TO
SOME DEGREE ALONG/EAST OF THE BLUE RIDGE. MODELS ALSO TOO MOIST
IN SHOWING REDEVELOPMENT OF LOW CLOUDS INCLUDING MVFR/IFR
CONDITIONS ALONG WITH SHOWERS INTO THE OVERNIGHT. THUS TRENDING
MORE VFR UNTIL THE EARLY MORNING HOURS AT THIS POINT.
GUIDANCE AGAIN WANTING TO FLOP THE WEDGE BACK ACROSS MUCH OF THE
REGION OVERNIGHT AS THE AXIS OF DEEPER MOISTURE TO THE WEST EDGES
CLOSER LATE. THIS LOOKS ON TRACK BY DAYBREAK SUNDAY WITH PERHAPS A
BAND OF SHOWERS NEARING THE KBLF VICINITY AS WELL BY EARLY IN THE
MORNING. THUS FOLLOWED CLOSER TO THE LATEST LAV GUIDANCE IN
DELAYING THE ONSET OF MVFR CIGS UNTIL AFTER MIDNIGHT MOST
SITES...WITH POSSIBLE IFR AROUND KBLF AND ALONG THE BLUE RIDGE.
APPEARS A SIMILAR SCENARIO REGARDING FOG WITH VSBY RESTRICTIONS
LIKELY DUE MORE TO A LOWERING OF THE STRATUS DECK ALONG THE RIDGES
VS RADIATIVE NATURE GIVEN CLOUD COVER EXCLUDING PERHAPS KDAN/KLYH
LATE WHERE SOME PATCHY MVFR TO IFR FOG POSSIBLE.
DISTURBANCE ACROSS THE MISSISSIPPI VALLEY WILL LIFT BY TO THE WEST
SUNDAY INTO SUNDAY NIGHT BRINGING A BROAD AREA OF DEEP MOISTURE
ACROSS THE REGION BY SUNDAY AFTERNOON...WITH SHOWERS CONTINUING
INTO MUCH OF SUNDAY NIGHT. ALTHOUGH COVERAGE LOOKS RATHER
WIDESPREAD WITHIN THE MOISTURE CANOPY...INTENSITY LIKELY CONFINED
TO BANDS OF EMBEDDED HEAVIER SHOWERS WITH SOME THUNDER POSSIBLE
MAINLY EAST LATER SUNDAY. FOR NOW GIVEN LIMITED INSTABILITY AND A
RATHER SATURATED ENVIRONMENT...WILL LEAVE OUT ANY TSRA MENTION
WHILE INCLUDING SOME DEGREE OF MVFR IN SHOWERS FOR MOST SITES
AFTER A BRIEF PERIOD OF IMPROVEMENT ESPCLY EAST SUNDAY MORNING.
EXTENDED DISCUSSION...
WILL SEE ANOTHER UPPER DISTURBANCE PASS TO THE NORTHWEST MONDAY
WITH A TRAILING TROUGH AXIS CROSSING THE REGION. AFTER INTERVALS
OF VFR MONDAY MORNING...SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS ARE EXPECTED IN THE AFTERNOON RESULTING IN PERIODS
OF MVFR/IFR IN LOW CIGS/RAINFALL. THE ENVIRONMENT MAY BE FAVORABLE
FOR HAIL WITH ANY OF THE STRONGER STORMS.
TUESDAY WILL FIND US BETWEEN SYSTEMS SO SOME IMPROVEMENT TO MAINLY
VFR EXPECTED. NEXT COLD FRONT APPROACHES FROM THE NORTHWEST
WEDNESDAY WITH PERHAPS A FEW SHOWERS...INCLUDING A PERIOD OF MVFR
IN THE MOUNTAINS.
SHOULD RETURN TO VFR POST FRONTAL THURSDAY EXCEPT LINGERING MVFR
POSSIBLE KLWB/KBLF.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH
NEAR TERM...JH/WP
SHORT TERM...PM
LONG TERM...PM
AVIATION...AMS/JH/WP
AREA FORECAST DISCUSSION
NWS SEATTLE WA
910 AM PDT SUN MAR 13 2016
.SYNOPSIS...A VIGOROUS STORM WILL BRING VERY WINDY CONDITIONS TO
WESTERN WASHINGTON THROUGH THIS EVENING...ALONG WITH RAIN IN THE
LOWLANDS AND SNOW IN THE MOUNTAINS. COOL MOIST WESTERLY FLOW WILL
MAINTAIN SHOWERS MONDAY THOUGH WEDNESDAY WITH MORE MOUNTAIN SNOW. AN
UPPER LEVEL RIDGE IS WILL BRING DRY MILD WEATHER THURSDAY THROUGH
SATURDAY.
&&
.SHORT TERM...THE STORM IS MOVING FASTER THAT PREVIOUSLY EXPECTED.
BUOY 89 WEST OF THE N OREGON COAST WAS DOWN TO 983 MB AT 15Z...A
LITTLE DEEPER THAN FORECAST. HOWEVER THE MOST IMPORTANT CHANGE IS
THAT THE LOW IS MOVING FASTER THAN EXPECTED AND THE STRONGEST WINDS
ARE NOW EXPECTED 2-3 HOURS SOONER. THE HIGH WIND WARNING STATEMENT
HAS BEEN UPDATED WITH THIS CHANGE.
RECENT HOURLY HRRR RUNS AS WELL SOME OF THE EARLIER 00Z AND 06Z
MODELS ALSO TRACK THE LOW SLIGHTLY FARTHER TO THE NW...MORE OVER THE
NW OLYMPICS. THE MODELS ARE ALSO RUNNING SLIGHTLY WEAKER ON THE
WINDS. 925 MB WINDS ARE CLOSER TO 50 KT WHICH WOULD TRANSLATE TO
SURFACE GUSTS IN THE 50-60 MPH RANGE. SUSTAINED SURFACE WINDS WILL
STILL BE IN THE 25-40 MPH RANGE. WINDS WILL DIMINISH SOONER AS WELL
WITH WINDS EASING SLOWLY FROM LATE AFTERNOON THROUGH MID EVENING.
OTHERWISE THERE IS NO CHANGE TO THE FORECAST. SIGNIFICANT...WARNING
LEVEL...SNOW IS STILL EXPECTED OVER MOUNT BAKER AND MOUNT RAINIER
THIS AFTERNOON THROUGH MONDAY MORNING...WITH LOWER ADVISORY LEVEL
AMOUNTS EXPECTED OVER SNOQUALMIE AND STEVENS PASS. KAM
REMAINDER OF THE DISCUSSION FROM THE 301 AM AFD...AN UPPER TROUGH
WILL FOLLOW THE FRONTAL SYSTEM TONIGHT...WITH MOIST WESTERLY FLOW AT
LOWER LEVELS. FORECAST PRECIPITATION AMOUNTS HAVE NOT CHANGED MUCH.
RAINFALL IN THE INTERIOR LOWLANDS FOR TODAY AND TONIGHT SHOULD BE
MAINLY 0.25 TO 0.75 INCH...WITH 0.50 TO 1.25 INCH AT THE COAST. THE
SNOW LEVEL WILL BE 2500 TO 3500 FT TODAY AND TONIGHT...AND FALL TO
2000 FT MONDAY AS ANOTHER SHORTWAVE IN THE WESTERLY FLOW MOVES
THROUGH THE AREA. UP TO 2.5 INCHES LIQUID EQUIVALENT PRECIPITATION
WILL FALL IN THE MOUNTAINS TODAY THROUGH MONDAY...WITH THE HEAVIEST
AMOUNTS AROUND MOUNT BAKER AND MOUNT RAINIER. A WINTER STORM WARNING
WILL REMAIN IN EFFECT FROM NOON TODAY THROUGH NOON MONDAY FOR THE
CASCADES OF WHATCOM AND SKAGIT COUNTIES AND THE CASCADES OF PIERCE
AND LEWIS COUNTIES. A WINTER WEATHER ADVISORY WILL REMAIN IN EFFECT
FOR THE CASCADES OF SNOHOMISH AND KING COUNTIES.
AN UPPER RIDGE WILL START BUILDING WELL OFFSHORE ON TUESDAY...BUT
MOIST ONSHORE FLOW WILL CONTINUE ACROSS WESTERN WASHINGTON WITH
MAYBE ANOTHER WEAK SHORTWAVE MOVING THROUGH. IT STILL LOOKS LIKE A
RATHER SHOWERY DAY ESPECIALLY FOR THE COAST AND MOUNTAINS. THE
SNOW LEVEL WILL STILL BE 2000 TO 2500 FT. MCDONNAL
.LONG TERM...THE UPPER RIDGE WILL BUILD OFFSHORE ALONG 135W ON
WEDNESDAY...WITH THE FLOW ALOFT VEERING TO NORTHWEST OVER WESTERN
WASHINGTON AND THE AIR MASS GRADUALLY DRYING. THE UPPER RIDGE WILL
MOVE SLOWLY TOWARD THE REGION THURSDAY AND FRIDAY...THEN WEAKEN AS
IT MOVES INLAND ON SATURDAY. THIS SHOULD BE A DRY PERIOD WITH SOME
SUNSHINE. MCDONNAL
&&
.AVIATION...A BROAD UPPER TROUGH OFFSHORE WITH STRONG SW FLOW ALOFT
OVER WA. THE FLOW ALOFT WILL TURN MORE WESTERLY TONIGHT. AN INTENSE
LOW PRESSURE CENTER JUST OFF THE NORTHERN OREGON COAST THIS MORNING
IS EXPECTED TO TRACK NE ACROSS NW WA THIS AFTERNOON WITH ASSOCIATED
STRONG WIND OF GUSTS 40-70 KT THROUGH THIS EVENING. AIR MASS STABLE
WITH INCREASING MOISTURE THIS MORNING. AIR MASS BECOMING UNSTABLE
AFTER 20Z.
RAIN SPREADING INLAND THIS MORNING WITH CEILINGS DROPPING TO MVFR
MOST AREAS. RAIN TURNING TO SHOWERS THIS AFTERNOON WITH CEILINGS IN
THE VICINITY OF SHOWERS REMAINING MVFR...LIKELY BREAKS IN CLOUD
COVER BEYOND SHOWERS. EXPECT A LOT OF MECHANICAL TURBC ASSOCIATED
WITH THE STRONG WINDS. NOT A GOOD DAY FOR FLYING...TIE AIRCRAFT DOWN
OR SHELTER IN A HANGER IF POSSIBLE.
KSEA...VFR CEILINGS WILL LIKELY FALL TO MVFR BEFORE 18Z IN RAIN.
SE WIND 8-14 KT THIS MORNING PICKING UP MIDDAY AND BECOMING
SOUTHERLY WITH GUSTS AS HIGH AS 50 KT OR SO. BUEHNER
&&
.MARINE...A 985 MB SURFACE LOW AT 15Z THIS MORNING 150 NM OFF
CASCADE HEAD IS EXPECTED TO TRACK NE AND CROSS THE OLYMPIC PENINSULA
AS A 978 MB LOW LATE THIS AFTERNOON. THIS SYSTEM WILL BRING STORM
FORCE WINDS TO MOST COASTAL WATERS...IF NOT WITH THE PRE-LOW
SOUTHEASTERLIES...THEN WITH THE POST-LOW WEST AND SOUTHWESTERLIES. A
GOOD DAY TO STAY IN PORT AND SECURELY TIE YOUR BOAT DOWN.
SEAS WILL BUILD TO 20 TO 24 FT TONIGHT WITH THE HIGHEST SEAS AROUND
GRAYS HARBOR. SOME BEACH EROSION IS LIKELY.
ONSHORE FLOW WILL DIMINISH MONDAY AND TUESDAY. HIGHER PRES IS
FORECAST TO BUILD OVER THE REGION WEDNESDAY WITH OFFSHORE FLOW
THURSDAY. BUEHNER
&&
.HYDROLOGY...THE SKOKOMISH RIVER WILL PROBABLY FLOOD AGAIN
TONIGHT. A FLOOD WATCH IS IN EFFECT FOR MASON COUNTY.
OTHERWISE FLOODING IS NOT EXPECTED ON AREA RIVERS FOR THE NEXT
WEEK.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...HIGH WIND WARNING TODAY TO 11 PM PDT THIS EVENING FOR
BELLEVUE AND VICINITY-BREMERTON AND VICINITY-CENTRAL COAST-
EAST PUGET SOUND LOWLANDS-EVERETT AND VICINITY-HOOD CANAL
AREA-LOWER CHEHALIS VALLEY AREA-NORTH COAST-SEATTLE AND
VICINITY-SOUTHWEST INTERIOR-TACOMA AREA.
COASTAL FLOOD ADVISORY UNTIL 11 AM PDT THIS MORNING FOR
ADMIRALTY INLET AREA-BREMERTON AND VICINITY-EVERETT AND
VICINITY-HOOD CANAL AREA-SEATTLE AND VICINITY-SOUTHWEST
INTERIOR-TACOMA AREA.
WINTER WEATHER ADVISORY UNTIL NOON PDT TODAY FOR CASCADES OF
PIERCE AND LEWIS COUNTIES.
WINTER STORM WARNING FROM NOON TODAY TO NOON PDT MONDAY FOR
CASCADES OF PIERCE AND LEWIS COUNTIES-CASCADES OF WHATCOM
AND SKAGIT COUNTIES.
WINTER WEATHER ADVISORY FROM NOON TODAY TO NOON PDT MONDAY FOR
CASCADES OF SNOHOMISH AND KING COUNTIES.
FLOOD WATCH FROM NOON PDT TODAY THROUGH MONDAY MORNING FOR HOOD
CANAL AREA-LOWER CHEHALIS VALLEY AREA-OLYMPICS.
HIGH WIND WARNING TO 11 PM PDT THIS
EVENING FOR ADMIRALTY INLET AREA-SAN JUAN COUNTY-WESTERN
SKAGIT COUNTY-WESTERN WHATCOM COUNTY.
COASTAL FLOOD ADVISORY UNTIL 9 AM PDT THIS MORNING FOR CENTRAL
COAST.
HIGH WIND WARNING TODAY FOR THE EASTERN STRAIT OF JUAN DE FUCA.
PZ...SMALL CRAFT ADVISORY FOR ROUGH BAR UNTIL 11 AM PDT MONDAY FOR
GRAYS HARBOR BAR.
STORM WARNING COAST AND NORTHERN INLAND WATERS.
STORM WARNING CENTRAL AND EAST STRAIT OF JUAN DE FUCA.
GALE WARNING WEST ENTRANCE U.S. WATERS STRAIT OF JUAN DE FUCA
...ADMIRALTY INLET-PUGET SOUND AND HOOD CANAL.
&&
$$
WWW.WEATHER.GOV/SEATTLE
YOU CAN SEE AN ILLUSTRATED VERSION OF THIS DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
AREA FORECAST DISCUSSION
NWS SEATTLE WA
301 AM PDT SUN MAR 13 2016
.SYNOPSIS...A VIGOROUS STORM WITH A DEVELOPING SURFACE LOW WILL
BRING VERY WINDY CONDITIONS TO WESTERN WASHINGTON THIS AFTERNOON
AND EVENING...ALONG WITH RAIN IN THE LOWLANDS AND SNOW IN THE
MOUNTAINS. COOL MOIST WESTERLY FLOW WILL MAINTAIN SHOWERS MONDAY
THOUGH WEDNESDAY WITH MORE MOUNTAIN SNOW. AN UPPER LEVEL RIDGE IS
WILL BRING DRY MILD WEATHER THURSDAY THROUGH SATURDAY.
&&
.SHORT TERM...MOIST SOUTHWEST FLOW ALOFT CONTINUES OVER THE
PACIFIC NORTHWEST EARLY THIS MORNING...WITH A WEAK SHORTWAVE
TROUGH MOVING THROUGH WASHINGTON. A BAND OF SHOWERS ASSOCIATED
WITH THE SHORTWAVE IS MOVING NORTHEAST THROUGH THE SOUTHWEST PART
OF WESTERN WASHINGTON...AND IT SHOULD REACH THE PUGET SOUND REGION
IN THE NEXT COUPLE HOURS. OTHERWISE SKIES WERE MOSTLY CLOUDY WITH
SPOTTY LIGHT SHOWERS...AND LOCALLY WINDY CONDITIONS CONTINUED IN
THE NORTH INTERIOR.
A FRONTAL SYSTEM IS STARTING TO DEVELOP NEAR 42N/132W...WHICH
SHOWS UP IN THE WATER VAPOR SATELLITE IMAGERY. THIS IS THE
FEATURE THAT IS FORECAST TO BRING A WINDSTORM TO WESTERN
WASHINGTON THIS AFTERNOON AND EVENING...AS ITS SURFACE LOW DEEPENS
TO AROUND 980 MB OFF THE COAST OF WASHINGTON AND TRACKS NORTHEAST
ACROSS THE SOUTH END OF VANCOUVER ISLAND.
THERE IS A CLUSTER OF THE MOST RECENT MODEL SOLUTIONS THAT STILL
FOLLOWS THE STORM TRACK DESCRIBED JUST ABOVE -- INCLUDING THE
ECMWF...NAM...AND GFS20. THE GFS40 SHOWS THE LOW CURVING MORE
SHARPLY NORTH...REMAINING WEST OF THE WASHINGTON COAST AND
CROSSING THE MIDDLE OR NORTH PART OF VANCOUVER ISLAND. THAT WOULD
PRODUCE A SOUTHEAST SUCKER EVENT...WHERE HIGH WINDS ARE GENERALLY
LIMITED TO THE COAST AND NORTH INTERIOR. THE HRRR -- WHICH RUNS
EVERY HOUR AND GOES OUT ONLY 14 HOURS -- SHOWS THE LOW ON A TRACK
THAT IS FURTHER EAST AND SOUTH OF THE MAIN CLUSTER OF
SOLUTIONS...MAKING LANDFALL NEAR LONG BEACH.
IN GENERAL THE MODELS HAVE BACKED OFF SOMEWHAT ON THE DEPTH OF THE
LOW -- SOMEWHERE NEAR 980 MB NOW LOOKS MOST LIKELY -- AND THE
STRENGTH OF THE PRESSURE DIFFERENCE AND WINDS ACROSS THE AREA. THE
ECMWF SHOWS THE PDX-BLI PRESSURE DIFFERENCE PEAKING AROUND 12 MB
LATE TODAY AS IT CROSSES THE SOUTH END OF VANCOUVER ISLAND...WHICH
IS CERTAINLY ENOUGH FOR LOCALIZED HIGH WINDS IN THE WESTERN
WASHINGTON INTERIOR. THE GFS20 ALSO SHOWS A PRESSURE GRADIENT
STRONG ENOUGH TO PRODUCE LOCAL HIGH WINDS IN THE INTERIOR LOWLANDS
INCLUDING THE PUGET SOUND REGION.
BOTTOM LINE IS THAT CONFIDENCE IN A SIGNIFICANT WINDSTORM IS NOT
AS HIGH AS IT WAS 12 OR 24 HOURS AGO. THE HIGH WIND WARNINGS WERE
ISSUED SATURDAY AFTERNOON...AND THEY WILL REMAIN IN EFFECT. WE
ARE LOWERING THE WIND SPEEDS SOMEWHAT -- ESSENTIALLY FORECASTING
HIGHEST WINDS OF 40 TO 45 MPH WITH GUSTS 55 TO 60 MPH RATHER THAN
THE 40 TO 50 MPH WITH GUSTS 70 MPH OF THE PREVIOUS FORECAST. IN
MOST AREAS THE STRONGEST WINDS SHOULD OCCUR THIS AFTERNOON AND
EVENING.
AN UPPER TROUGH WILL FOLLOW THE FRONTAL SYSTEM TONIGHT...WITH
MOIST WESTERLY FLOW AT LOWER LEVELS. FORECAST PRECIPITATION
AMOUNTS HAVE NOT CHANGED MUCH. RAINFALL IN THE INTERIOR LOWLANDS
FOR TODAY AND TONIGHT SHOULD BE MAINLY 0.25 TO 0.75 INCH...WITH
0.50 TO 1.25 INCH AT THE COAST. THE SNOW LEVEL WILL BE 2500 TO
3500 FT TODAY AND TONIGHT...AND FALL TO 2000 FT MONDAY AS ANOTHER
SHORTWAVE IN THE WESTERLY FLOW MOVES THROUGH THE AREA. UP TO 2.5
INCHES LIQUID EQUIVALENT PRECIPITATION WILL FALL IN THE MOUNTAINS
TODAY THROUGH MONDAY...WITH THE HEAVIEST AMOUNTS AROUND MOUNT
BAKER AND MOUNT RAINIER. A WINTER STORM WARNING WILL REMAIN IN
EFFECT FROM NOON TODAY THROUGH NOON MONDAY FOR THE CASCADES OF
WHATCOM AND SKAGIT COUNTIES AND THE CASCADES OF PIERCE AND LEWIS
COUNTIES. A WINTER WEATHER ADVISORY WILL REMAIN IN EFFECT FOR THE
CASCADES OF SNOHOMISH AND KING COUNTIES.
AN UPPER RIDGE WILL START BUILDING WELL OFFSHORE ON TUESDAY...BUT
MOIST ONSHORE FLOW WILL CONTINUE ACROSS WESTERN WASHINGTON WITH
MAYBE ANOTHER WEAK SHORTWAVE MOVING THROUGH. IT STILL LOOKS LIKE A
RATHER SHOWERY DAY ESPECIALLY FOR THE COAST AND MOUNTAINS. THE
SNOW LEVEL WILL STILL BE 2000 TO 2500 FT. MCDONNAL
.LONG TERM...THE UPPER RIDGE WILL BUILD OFFSHORE ALONG 135W ON
WEDNESDAY...WITH THE FLOW ALOFT VEERING TO NORTHWEST OVER WESTERN
WASHINGTON AND THE AIR MASS GRADUALLY DRYING. THE UPPER RIDGE WILL
MOVE SLOWLY TOWARD THE REGION THURSDAY AND FRIDAY...THEN WEAKEN AS
IT MOVES INLAND ON SATURDAY. THIS SHOULD BE A DRY PERIOD WITH SOME
SUNSHINE. MCDONNAL
&&
.AVIATION...A BROAD UPPER TROUGH WILL REMAIN OVER THE REGION
TODAY WITH STRONG SOUTHWEST FLOW ALOFT. UPPER FLOW WILL TURN MORE
WESTERLY TONIGHT. A DEEP LOW PRESSURE CENTER WILL MOVE NORTHEAST
ACROSS WASHINGTON THIS AFTERNOON. MANY AIRPORTS COULD HAVE GUSTS
OF 40-60 KT THIS AFTERNOON AND EVENING.
THE AIR MASS IS STABLE AND MOIST WITH INCREASING CLOUDS ALL
LEVELS. RAIN ON THE COAST WILL SPREAD INLAND THIS MORNING...THEN
TURN TO SHOWERS TONIGHT. MOST CEILINGS INLAND ARE VFR BUT AS RAIN
DEVELOPS THEY WILL FALL TO MVFR 2-3K FT AND REMAIN MVFR ALL DAY
AND PROBABLY TONIGHT AS WELL.
KSEA...VFR CEILINGS EARLY THIS MORNING WILL LIKELY FALL TO MVFR
LATER THIS MORNING. WINDSTORM EXPECTED THIS AFTERNOON AND EVENING
WITH PEAK WIND GUSTS 45-55 KT POSSIBLE 22Z-03Z. CHB
&&
MARINE...A 980 MB SURFACE LOW WILL CROSS THE OLYMPIC PENINSULA LATE
THIS AFTERNOON. THIS WILL BRING STORM FORCE WINDS TO MOST OF THE
WATERS...IF NOT IN THE PRE-LOW SOUTHEASTERLIES...THEN IN THE
POST- LOW WEST- AND SOUTHWESTERLIES.
SEAS WILL BUILD TO 20 TO 23 FT TONIGHT WITH THE HIGHEST SEAS AROUND
GRAYS HARBOR. SOME BEACH EROSION IS LIKELY.
ONSHORE FLOW WILL DIMINISH MONDAY AND TUESDAY. HIGH PRES WILL BUILD
OVER THE AREA WEDNESDAY WITH OFFSHORE FLOW THURSDAY. CHB
&&
.HYDROLOGY...THE SKOKOMISH RIVER WILL PROBABLY FLOOD AGAIN
TONIGHT. A FLOOD WATCH IS IN EFFECT FOR MASON COUNTY.
OTHERWISE FLOODING IS NOT EXPECTED ON AREA RIVERS FOR THE NEXT
WEEK.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...HIGH WIND WARNING FROM NOON TODAY TO 11 PM PDT THIS EVENING FOR
BELLEVUE AND VICINITY-BREMERTON AND VICINITY-CENTRAL COAST-
EAST PUGET SOUND LOWLANDS-EVERETT AND VICINITY-HOOD CANAL
AREA-LOWER CHEHALIS VALLEY AREA-NORTH COAST-SEATTLE AND
VICINITY-SOUTHWEST INTERIOR-TACOMA AREA.
COASTAL FLOOD ADVISORY UNTIL 11 AM PDT THIS MORNING FOR
ADMIRALTY INLET AREA-BREMERTON AND VICINITY-EVERETT AND
VICINITY-HOOD CANAL AREA-SEATTLE AND VICINITY-SOUTHWEST
INTERIOR-TACOMA AREA.
WINTER WEATHER ADVISORY UNTIL NOON PDT TODAY FOR CASCADES OF
PIERCE AND LEWIS COUNTIES.
WINTER STORM WARNING FROM NOON TODAY TO NOON PDT MONDAY FOR
CASCADES OF PIERCE AND LEWIS COUNTIES-CASCADES OF WHATCOM
AND SKAGIT COUNTIES.
WINTER WEATHER ADVISORY FROM NOON TODAY TO NOON PDT MONDAY FOR
CASCADES OF SNOHOMISH AND KING COUNTIES.
FLOOD WATCH FROM NOON PDT TODAY THROUGH MONDAY MORNING FOR HOOD
CANAL AREA-LOWER CHEHALIS VALLEY AREA-OLYMPICS.
HIGH WIND WARNING FROM 2 PM THIS AFTERNOON TO 11 PM PDT THIS
EVENING FOR ADMIRALTY INLET AREA-SAN JUAN COUNTY-WESTERN
SKAGIT COUNTY-WESTERN WHATCOM COUNTY.
COASTAL FLOOD ADVISORY UNTIL 9 AM PDT THIS MORNING FOR CENTRAL
COAST.
HIGH WIND WARNING FROM 6 PM TO 11 PM PDT THIS EVENING FOR
EASTERN STRAIT OF JUAN DE FUCA.
PZ...SMALL CRAFT ADVISORY FOR ROUGH BAR UNTIL 11 AM PDT MONDAY FOR
GRAYS HARBOR BAR.
STORM WARNING FROM 11 AM THIS MORNING TO 11 PM PDT THIS EVENING
FOR COASTAL WATERS FROM CAPE FLATTERY TO JAMES ISLAND 10 TO
60 NM-COASTAL WATERS FROM CAPE FLATTERY TO JAMES ISLAND OUT
10 NM-COASTAL WATERS FROM JAMES ISLAND TO POINT GRENVILLE
10 TO 60 NM-COASTAL WATERS FROM JAMES ISLAND TO POINT
GRENVILLE OUT 10 NM-COASTAL WATERS FROM POINT GRENVILLE TO
CAPE SHOALWATER 10 TO 60 NM-COASTAL WATERS FROM POINT
GRENVILLE TO CAPE SHOALWATER OUT 10 NM.
STORM WARNING FROM NOON TODAY TO 5 AM PDT MONDAY FOR CENTRAL
U.S. WATERS STRAIT OF JUAN DE FUCA-EAST ENTRANCE U.S.
WATERS STRAIT OF JUAN DE FUCA.
STORM WARNING FROM 2 PM THIS AFTERNOON TO 3 AM PDT MONDAY FOR
NORTHERN INLAND WATERS INCLUDING THE SAN JUAN ISLANDS.
GALE WARNING FROM 9 AM THIS MORNING TO 3 AM PDT MONDAY FOR WEST
ENTRANCE U.S. WATERS STRAIT OF JUAN DE FUCA.
GALE WARNING FROM 11 AM THIS MORNING TO 5 AM PDT MONDAY FOR
ADMIRALTY INLET-PUGET SOUND AND HOOD CANAL.
&&
$$
WWW.WEATHER.GOV/SEATTLE
YOU CAN SEE AN ILLUSTRATED VERSION OF THIS DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1157 PM CDT MON MAR 14 2016
.UPDATE...
ISSUED AT 855 PM CDT MON MAR 14 2016
Tricky overnight cloud/fog forecast across central and southeast
Illinois. Skies were steadily clearing from the west earlier this
evening. However, the clearing has slowed considerably, with the
cloud edge nearly along the I-74 corridor. Temperature/dew point
spreads across the area are quite small, and little to no sunshine
was available to help dry the wet ground from yesterday. These
factors, combined with light winds should allow stratus and/or fog
to develop once again tonight. The potential is certainly there
for dense fog to develop once again, but do not plan an advisory
at this time. Increasing southerly flow by late tonight ahead of
tomorrow`s storm system should help to blow the remaining low
cloud deck out of the area, and mix the low levels up a bit and
hopefully minimize the fog threat.
Going forecast is in pretty good shape. Already made adjustments
for less clouds in most areas. Most other tweaks were minor.
&&
.SHORT TERM...(Tonight)
ISSUED AT 235 PM CDT MON MAR 14 2016
19z/2pm visible satellite imagery continues to show cloudy skies
across central Illinois: however, holes are developing in the
overcast...particularly upstream across Iowa/Missouri. Low-level
flow remains weak, but this drier air will eventually filter into
the area this evening, resulting in a partial clearing trend. With
some clearing taking place and winds staying quite light, think fog
will re-develop tonight. Mitigating factors for widespread dense
fog will be partial cloud cover and increasing southeasterly winds
after midnight. HRRR is showing fog forming across much of the area
this evening, then becoming locally dense after midnight. Think
this is a bit overdone, so will only carry patchy fog at this time.
Most high-res models are suggesting scattered convection will
develop overnight across northern Missouri into Iowa as a
strengthening low-level jet noses into that area. Some of this
activity could spill into west-central Illinois toward dawn, so have
included low chance PoPs for showers/thunder along and west of the
Illinois River well after midnight. Overnight lows will be in the
lower to middle 50s.
.LONG TERM...(Tuesday through Monday)
ISSUED AT 235 PM CDT MON MAR 14 2016
Forecast concern continues to revolve around the the threat for
severe weather over parts of central through east central Illinois
tomorrow afternoon and evening as a rather potent upper wave
pushes into the Midwest.
Looks as though scattered precip chances tomorrow will be tied to
the surface and 850 mb warm front in the morning, mostly across
the west and north, and then along the cold front during the mid
to late afternoon and early evening hours as the cap weakens due
to increasing low level convergence forecast along the accelerating
cold front. The GFS continues to be the fast model, although
recent runs have trended a bit slower tomorrow afternoon, while
the ECMWF is deepest and slowest with the surface and upper level
features. Due to the slower movement in the cold frontal passage
and the cap holding on a bit longer than previously forecast, it
appears the main time frame for the threat for scattered storms
across the forecast area will be roughly 4pm until 10 pm. The NAM
and ECMWF indicates the better low level shear profiles for any
persistent rotating storms capable of large hail and isolated
tornadoes will be along and north of I-74, while low level wind
profiles become more unidirectional further south by late in the
afternoon. However, the further south you go, the stronger the
capping inversion is, but believe at least widely scattered storms
will be possible as you head into southeast IL late tomorrow
afternoon through the evening hours. All models indicate steep low
and mid level lapse rates with 700-500 mb lapse rates approaching
8 C/KM tomorrow afternoon and evening suggesting the threat for
large hail along with damaging wind gusts, especially if the mode
transitions to a line of storms with time late in the afternoon
into the evening hours.
Models sweep the storms well off to our east by 03z with lingering
low chance POPs over the far north during the overnight hours
along with gusty winds as the deepening surface low shifts slowly
off to our north. Windy but mild conditions are expected Wednesday
before we see a gradual transition to cooler weather by the end of
the week and next weekend where afternoon temperatures will lower
into the upper 40s to lower 50s. As far as precip is concerned in
the extended, several weak waves are forecast to rotate south
around the deep upper low to our north which may produce some
isolated light showers with the main threat of rain coming along
over the weekend as the upper low to our north repositions itself
a bit further south over the Midwest. This will bring about
mentionable rain chances in the forecast on Saturday into Saturday
night.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
ISSUED AT 1155 PM CDT MON MAR 14 2016
Patchy dense fog has developed across parts of central Illinois
this evening, including some of the local TAF sites. This trend
should continue for much of the night, although it may be
mitigated to some degree by increasing upper-level cloudiness and
increasing southeasterly winds. Any fog/stratus should burn off
pretty quickly Tuesday morning. Then, attention turns to a strong
cold front later Tuesday and the associated threat for
thunderstorms. Much of the pre-frontal airmass should be capped
and may preclude much in terms of storm development. The capping
breaks the earliest and the dynamics supporting storm development
are best at KPIA & KBMI early in the evening. Included a VCTS for
these sites, but feel the anticipated coverage is too low to
mention in the other local TAF sites at this time.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...BAK
SHORT TERM...Barnes
LONG TERM...Smith
AVIATION...BAK
AREA FORECAST DISCUSSION
NWS DES MOINES IA
405 AM CDT TUE MAR 15 2016
.SHORT TERM /TODAY/...
ISSUED AT 404 AM CDT TUE MAR 15 2016
FOR TODAY THE UPPER TROUGH WILL PIVOT THROUGH THE STATE TODAY INTO
TONIGHT. MEANWHILE A DEEPENING SURFACE LOW WILL LIFT OUT OF KANSAS
INTO MISSOURI THEN INTO SOUTHEASTERN IOWA BY 00Z. THE LOW IS
CURRENTLY PART OF A BROADER SURFACE LOW WITH A COLD FRONT MOVING
INTO EASTERN NEBRASKA AND IS RESPONSIBLE FOR SHOWERS/THUNDERSTORMS
OVER WESTERN IOWA WHICH WILL PIVOT NORTHEAST THROUGH THE MORNING
HOURS. THEN LATER THIS AFTERNOON AS THE SURFACE LOW DEEPENS AND THE
UPPER TROUGH BECOMES NEGATIVELY TILTED WITH A BIT OF A WARM FRONT
DEVELOPING IN OUR FAR SOUTHEAST BEFORE LIFTING OUT OF OUR FORECAST
AREA. ADDITIONAL THUNDERSTORMS WILL DEVELOP THIS AFTERNOON
ESPECIALLY OVER THE FAR EAST. GIVEN THE LOCATION OF A WARM FRONT
DEVELOPING AND STRONG FORCING AND INSTABILITY I HAD TO PUT
THUNDERSTORMS BACK IN THE FORECAST FOR THE AFTERNOON AND INCREASE
WORDING TO SCATTERED COVERAGE. WE WILL LIKELY SEE A COUPLE OF
SEVERE STORMS LATE AFTERNOON BEFORE THE THREAT SHIFTS INTO FAR
EASTERN IOWA. BEHIND THIS...WINDS WILL BE INCREASING WITH COLD
ADVECTION WORKING IN...ESPECIALLY TONIGHT BUT I DO INCREASE WINDS
ACROSS THE WEST BY LATE AFTERNOON OUT OF THE NORTHWEST TO SPEEDS OF
20G30KTS.
.LONG TERM /TONIGHT THROUGH MONDAY/...
ISSUED AT 404 AM CDT TUE MAR 15 2016
EXTREMELY ACTIVE WEATHER OVER THE NEXT FEW DAYS. POTENTIAL FOR
THUNDERSTORMS TO LINGER AFTER 00Z THIS EVENING HOWEVER BY THAT
TIME...ANY SEVERE WEATHER THREAT SHOULD HAVE PASSED TO THE EAST AS
THE SFC LOW PRESSURE LIFTS INTO SOUTHEAST IOWA. A DEFORMATION AREA
OF PRECIPITATION WILL CONTINUE TO THE WEST/NORTHWEST OF THE SFC
LOW. PRECIPITATION RATES WILL BE EFFICIENT WITH PWAT VALUES OVER
1 INCH THROUGH A SATURATED LAYER AND WARM CLOUD DEPTHS TO OVER 8
KFT...WHICH IS FAVORABLE FOR MARCH.
THE MOST SIGNIFICANT IMPACT WITH THIS SYSTEM COULD BE THE TRAILING
WINDS. THE PRESSURE GRADIENT TIGHTENS QUICKLY OVERNIGHT AS THE LOW
DEEPENS RAPIDLY. A PRESSURE GRADIENT IN EXCESS OF 75 UBARS/KM WILL
DEVELOP BY 06Z. IN ADDITION...A RIBBON OF 850 MB WINDS WILL REACH
70-80 KTS. POTENTIAL IS THERE TO MIX A PORTION OF THESE WINDS DOWN
TO THE SFC AS LOW LEVEL LAPSE RATES STEEPEN AND MIXING INCREASES
OVERNIGHT WITH MID LEVEL COOLING WHILE SFC TEMPERATURES REMAIN
NEAR STEADY. HAVE CONCERNS THAT SFC WINDS MAY REACH 60+ MPH AFTER
06Z THROUGH 15Z ON WEDNESDAY...WHICH IS THE PERIOD OF PEAK WINDS.
SUBSIDENCE ARRIVES THROUGH THE DAY ON WEDNESDAY AND WILL FURTHER
DEEPEN THE MIXING TO NEAR 600-500 MB. MIXED LAYER WINDS WILL
RELAX A BIT DURING THIS TIME BUT REMAIN IN THE 45 TO 55 KT RANGE.
THEREFORE THE THREAT FOR HIGH WINDS WILL REMAIN THROUGH THE DAY.
HAVE ISSUED A HIGH WIND WATCH FOR MUCH OF THE FORECAST AREA
ALONG AND NORTH OF INTERSTATE 80. SUSPECT THAT MAY NEED TO FURTHER
EXPAND THE AREAL COVERAGE WITH FUTURE UPDATES BUT THIS IS A GOOD
START. THE WIND WILL SUBSIDE A BIT WEDNESDAY NIGHT. MIXING WILL
HELP DRIVE GUSTS AGAIN ON THURSDAY WITH GUSTS AGAIN APPROACHING 40
TO 50 MPH.
THE LOW PRESSURE WILL WOBBLE A BIT TO THE NORTH BEFORE A LOBE
DROPS SOUTH WEDNESDAY NIGHT INTO THURSDAY. THIS WILL PUSH MUCH
COOLER TEMPERATURES ALOFT INTO THE STATE AND WILL BRING THE
POTENTIAL FOR LIGHT SNOW AT TIMES FROM WEDNESDAY NIGHT THROUGH
FRIDAY MORNING WITH MINOR ACCUMULATIONS POSSIBLE. MODEL GUIDANCE
CONTINUES TO APPEAR TO BE CARRYING A WARM BIAS THROUGH THIS PERIOD
AND HAVE LOWERED HIGH TEMPERATURES. SOUNDING LOW LEVEL MIXING
THURSDAY INTO FRIDAY LOOKS EXAGGERATED AND OVERDONE. ANOTHER UPPER
LEVEL SYSTEM WILL DROP THROUGH THE AREA ON SATURDAY AND WILL
REINFORCE THE COLD AIR AND KEEP THE COOLER TEMPERATURES AROUND. A
RETURN TO A MORE ZONAL AND WARMER FLOW WILL FOLLOW BY THE EARLY
PORTION OF NEXT WEEK.
&&
.AVIATION...15/06Z
ISSUED AT 1204 AM CDT TUE MAR 15 2016
LATEST HRRR HAS A DECENT HANDLE ON CONVECTIVE TRENDS OVERNIGHT
WITH TIMING ACROSS THE TAF LOCATIONS B/T 8-11Z FROM WEST TO EAST.
SUB-SEVERE ANTICIPATED BUT CANNOT RULE OUT BRIEF HEAVY RAIN. MVFR
AND EVEN BRIEF IFR CIGS ARE LIKELY DURING THE AFOREMENTIONED TIME.
SHOULD BE A BREAK IN THE PRECIP MID TO LATE MORNING BEFORE THE CAA
DEVELOPS AND BRINGS SHOWER/DRIZZLE ACTIVITY DURING THE AFTERNOON.
BETTER POTENTIAL HERE FOR IFR CIGS. STRONG WINDS DEVELOP TOWARDS
00Z WEDNESDAY AND INCREASED WIND GUSTS TUESDAY NIGHT.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...FAB
LONG TERM...DONAVON
AVIATION...PODRAZIK
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1207 AM CDT TUE MAR 15 2016
...UPDATED AVIATION DISCUSSION...
.SHORT TERM /TONIGHT/...
ISSUED AT 350 PM CDT MON MAR 14 2016
MAIN CONCERNS OVERNIGHT WILL BE THUNDER THREAT AND POTENTIAL FOR
ELEVATED STORMS WITH ISOLATED SVR HAIL. STRATUS HAS HELD ON MOST
AREAS THROUGH NOON BUT NOW GIVING WAY TO MIXED LAYER CU ALONG WITH
SUNSHINE OVER THE WESTERN/SOUTHERN AREAS. WE REMAIN IN THE WARM
SECTOR WITH WARM AND MOIST AIR EXPECTED OVERNIGHT AHEAD OF A NEW
WAVE EJECTING OUT OF THE WESTERN PLAINS CROSSING KANSAS TONIGHT.
BY 12Z THE SFC LOW SHOULD BE NEARING NORTHEAST KS WITH A WEAK LOW
LEVEL JET IMPINGING ON AN ELEVATED BOUNDARY OVER SOUTHERN IOWA.
ALONG THE NOSE OF THE JET AN EXPANDING AREA OF ELEVATED CONVECTION
IS LIKELY/ THUNDERSTORMS ARE EXPECTED TO BREAK OUT NEAR THE IOWA
NEBRASKA KANSAS BORDER NEAR 06Z AND EXPAND NORTHEAST INTO THE
REGION OVERNIGHT. BUFR SOUNDINGS SUPPORT ELEVATED CONVECTION WITH
CAPE ABOVE THE MIXED LAYER. THE EURO FORECASTS 600 TO 1000 J/KG OF
ELEVATED CAPE BY 06Z WITH INCREASING 0-6 KM BULK SHEAR TO 35 TO
45KT BY 12Z SOUTH HALF OF THE AREA. THIS SHOULD BE ENOUGH TO DRIVE
HAIL AND POTENTIALLY SOME ISOLATED SVR REPORTS OVERNIGHT...MAINLY
CLOSER TO THE NOSE OF THE JET OVER THE SOUTHERN/SOUTHEAST AREAS.
LOWS WILL BE QUITE MILD TONIGHT WITH READINGS IN THE LOWER 50S.
.LONG TERM /TUESDAY THROUGH MONDAY/...
ISSUED AT 350 PM CDT MON MAR 14 2016
NEGATIVELY-TILTED H300 TROUGH AND 140KT JET STREAK WILL DIG
SOUTHEASTWARD ACROSS NEBRASKA TOMORROW MORNING. THIS WILL CAUSE A
SURFACE LOW TO EJECT E/NE ACROSS THE REGION AND DEEPEN INTO A
APPROXIMATELY 990 MB CYCLONE OVER THE WESTERN GREAT LAKES BY 18Z
WEDNESDAY. THE 12Z NAM/GFS/EC HAVE BUDGED LITTLE FROM THEIR
PREVIOUS RESPECTIVE CAMPS ON THE EVOLUTION AND POSITION OF THE
LOW/TROUGH TOMORROW MORNING. THE DOMESTIC MODELS TAKE A WEAKER LOW
ALONG THE IOWA/MINNESOTA BORDER WHILE THE EC RAPIDLY DEEPENS THE
LOW AND LIFTS IT ACROSS SOUTHEAST IOWA. GIVEN THE DYNAMIC NATURE
OF THE SYSTEM...IT IS NOT TOO SURPRISING THAT THE MODELS ARE STILL
STRUGGLING TO RESOLVE THE SURFACE FEATURES LESS THAN 24 HOURS OUT
AND OVERALL FORECAST CONFIDENCE FOR TOMORROW IS LOWER THAN NORMAL.
CONTINUED THE GOING TREND OF TAKING THE BULK OF THE PRECIP THROUGH
TUESDAY MORNING WITH THE SURFACE TROUGH WITH LINGERING CHANCES
THROUGH THE AFTERNOON...BUT SHOULD THE EC SOLUTION PAN
OUT...PRECIP COULD LINGER WELL INTO THE AFTERNOON.
THE LOW PLACEMENT WILL ALSO DICTATE THE THUNDERSTORM THREAT DURING
THE EARLY AFTERNOON ON TUESDAY. A NARROW WINDOW OF SURFACE-BASED
CONVECTION IS POSSIBLE DURING THE 18 TO 21Z TIMEFRAME IN THE
EASTERN CWA WITH MLCAPE VALUES IN THE 500 TO 1000 J/KG RANGE. DEEP
SHEAR PROFILES OF 40 TO 60 KTS AND CLOSE PROXIMITY TO THE SURFACE
LOW COULD YIELD MULTIPLE MODES OF SEVERE WEATHER...BUT THE THREAT
WINDOW IS SMALL AND STORMS WILL QUICKLY MOVE NORTHEAST AT 40 KTS
AND OUT OF THE CWA.
A REX BLOCK WILL DEVELOP OVER THE NORTHERN CONUS AND SOUTHERN
CANADA BY MIDWEEK WITH COOL CYCLONIC NORTHWESTERLY FLOW ACROSS
THE REGION ALLOWING TEMPERATURES TO FALL TO MORE SEASONABLE VALUES
FOR THE LATTER HALF OF THE WEEK INTO NEXT WEEKEND. AN INFLUX OF
MID LEVEL DRY AIR AND STEEPENING LAPSE RATES WILL LEAD TO GUSTY
WINDS DURING THE DAY ON WEDNESDAY. BOTH GFS AND NAM BUFR SOUNDINGS
DEPICT A DOWNRIGHT IMPRESSIVE MIXED LAYER WEDNESDAY AFTERNOON WITH
NEAR ADIABATIC LAPSE RATES UP TO 500 TO 700 MB. WHILE SUSTAINED
WINDS WILL NOT BE TOO STRONG OWING TO A RELAXING PRESSURE
GRADIENT...IT WOULD NOT BE SURPRISING TO SEE GUSTS OVER 40 KTS.
AN INVERTED SURFACE TO H850 TROUGH WILL SAG SOUTHWARD BETWEEN
THURSDAY AND FRIDAY AND BRING THE POSSIBILITY OF RAIN AND A
NIGHTTIME RAIN/SNOW MIX TO MOSTLY THE NORTHERN HALF OF THE STATE.
AN APPROACHING PV ANOMALY WILL HELP FUEL ANOTHER ROUND OF PRECIP
ON SATURDAY BEFORE UPPER LEVEL RIDGING BUILDS IN FOR LATE IN THE
WEEKEND AND EARLY NEXT WEEK.
&&
.AVIATION...15/06Z
ISSUED AT 1204 AM CDT TUE MAR 15 2016
LATEST HRRR HAS A DECENT HANDLE ON CONVECTIVE TRENDS OVERNIGHT
WITH TIMING ACROSS THE TAF LOCATIONS B/T 8-11Z FROM WEST TO EAST.
SUB-SEVERE ANTICIPATED BUT CANNOT RULE OUT BRIEF HEAVY RAIN. MVFR
AND EVEN BRIEF IFR CIGS ARE LIKELY DURING THE AFOREMENTIONED TIME.
SHOULD BE A BREAK IN THE PRECIP MID TO LATE MORNING BEFORE THE CAA
DEVELOPS AND BRINGS SHOWER/DRIZZLE ACTIVITY DURING THE AFTERNOON.
BETTER POTENTIAL HERE FOR IFR CIGS. STRONG WINDS DEVELOP TOWARDS
00Z WEDNESDAY AND INCREASED WIND GUSTS TUESDAY NIGHT.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...REV
LONG TERM...SKOW
AVIATION...PODRAZIK
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1138 PM CDT MON MAR 14 2016
...AVIATION UPDATE...
.SYNOPSIS...
ISSUED AT 330 PM CDT MON MAR 14 2016
18Z SFC DATA HAS AN IMPLIED FRONTAL BOUNDARY FROM NEAR KSUX TO NEAR
KEVV. DEW POINTS WERE IN THE 40S FROM THE GREAT LAKES INTO THE UPPER
MIDWEST WITH 50S FROM THE OHIO VALLEY INTO MID MISSISSIPPI VALLEY
AND DOWN TO THE GULF.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 330 PM CDT MON MAR 14 2016
SOME HOLES HAVE DEVELOPED IN THE LOW CLOUDS ACROSS THE AREA WHICH
HAS ALLOWED SOME BRIEF PEEKS OF SUN THIS AFTERNOON. RADAR TRENDS
SHOW THE SHOWERS NEAR KCID ARE RAPIDLY FALLING APART. THUS DRY
CONDITIONS ARE EXPECTED THROUGH SUNSET.
AFTER SUNSET...DRY CONDITIONS WILL CONTINUE THROUGH MID EVENING.
BETWEEN 10 PM AND 1 AM THERE MAY OR MAY NOT BE SOME ISOLATED SHOWERS
DEVELOP NORTH AND WEST OF A LINE FROM DUBUQUE TO GRINNELL.
INTERNALLY...MOST OF THE MODELS AND TRENDS FROM THE RAP ARE
SUGGESTING DRY CONDITIONS THROUGH MIDNIGHT.
BY MIDNIGHT...THE MODELS LOOSELY AGREE THAT A THUNDERSTORM COMPLEX
WILL HAVE DEVELOPED ALONG THE MO/KS BORDER UP INTO FAR SOUTHEAST
NEBRASKA. THIS THUNDERSTORM COMPLEX WILL THEN MOVE EAST NORTHEAST
AND ARRIVE IN EASTERN IOWA PRIOR TO SUNRISE WEDNESDAY. THIS COMPLEX
WILL STRATIFY OUT DUE TO MORE STABLE AIR ACROSS THE AREA BUT SOME
THUNDERSTORMS ARE EXPECTED DUE TO UNSTABLE AIR ALOFT. THE
POSSIBILITY DOES EXIST THAT SOME THUNDERSTORMS MAY PRODUCE HAIL THAT
COULD APPROACH SEVERE LIMITS.
THE DECAYING COMPLEX WILL MOVE ACROSS THE AREA DURING THE MORNING
THAT WILL PRODUCE BOUNDARIES FOR NEW CONVECTION TUESDAY AFTERNOON.
TUESDAY AFTERNOON...THE MAIN COLD FRONT WILL SWEEP THROUGH THE AREA.
DIURNAL HEATING COMBINED WITH THE FRONT AND BOUNDARIES FROM THE
OVERNIGHT CONVECTION WILL ALLOW NEW THUNDERSTORMS TO RAPIDLY DEVELOP.
SEVERAL FACTORS ARE IN PLACE FOR THE DEVELOPMENT OF SEVERE STORMS ON
TUESDAY. THE QUESTION IS HOW EACH COMES TOGETHER. TWO IMPORTANT
FACTORS WILL BE THE TIMING OF THE COLD FRONT AND DIURNAL HEATING.
THE WAY IT LOOKS RIGHT NOW...AREAS ALONG/EAST OF THE MISSISSIPPI
HAVE SLIGHTLY BETTER CHANCES OF SEEING SEVERE STORMS TUESDAY
AFTERNOON.
.LONG TERM...(TUESDAY NIGHT THROUGH NEXT MONDAY)
ISSUED AT 330 PM CDT MON MAR 14 2016
TUESDAY NIGHT AND WEDNESDAY...12Z RUN MODELS SHEAR OUT VIGOROUS
NEGATIVELY TILTED WAVE ACRS WI INTO THE WESTERN GRT LKS THIS
PERIOD...BUT IN VARYING STRENGTHS. WILL WALK OUT LINGERING STRONG TO
POSSIBLY SEVERE BROKEN LINE OF STORMS OUT OF NORTHWESTERN IL BY
01Z...IF THEY DON/T EXIT EARLIER THAN THAT. THEN THE MODELS
DIVERGE...WITH THE 12Z ECMWF CONTINUING TO BE THE MOST DYNAMICAL IN
HANDLING THE LOW WITH THE SFC FEATURE DEEPENING TO UNDER 990 MB ACTS
CENTRAL WI BY WED MORNING. THE EURO PRODUCES STRONG WRAP AROUND
SHOWERS AND EMBEDDED ADDITIONAL CONVECTION AND THUS IS ADVERTISING
OVER AN INCH OF RAIN TUE EVENING IN MUCH OF EST CENTRAL IA NORTH OF
I80 AND WEST OF THE MS RVR. IT THEN CONTINUES WRAP-AROUND ALONG AND
NORTH OF I80 WITH ANOTHER 0.30-0.60+ OF AN INCH OF QPF NORTH OF THE
HWY 30 CORRIDOR FROM 06Z-12Z WED...WITH PARAMETERS COOLING TO NEAR
RAIN-SNOW MIX OR ALL WET SNOW ALONG HWY 20 LATE TUE NIGHT. MOST OF
THE OTHER 12Z MODEL SOLUTIONS NOT NEARLY SO BULLISH AND AFTER SOME
WRAP AROUND SHOWERS TUE EVENING BEHIND THE MAIN EXITING CONVECTIVE
LINE...THEY TRANSITION TO MAINLY DRY AFTER 06Z WED OR CLIPPING
NORTHWESTERN IL WITH SHOWERS/RAIN THROUGH 09Z WED BEFORE SWEEPING
OFF THE PRECIP TO THE EAST. FOR NOW WILL TAKE A BLEND THAT PRODUCES
A QUARTER OF AN INCH TO FOUR TENTHS OF AN INCH OF WRAP AROUND RAIN
ACRS THE NORTHEASTERN THIRD TO HALF OF THE DVN CWA BY 12Z WED
MORNING.
WED THE CWA TO CONTINUE TO BE IN TIGHT CYCLONIC GRADIENT OFF DEEP
CYCLONE IN EASTERN WI...WEST WINDS MAY GUST WELL OVER 30 MPH AND NOT
BE THAT FAR OFF ADVISORY LEVELS FOR SUSTAINED SPEEDS ESPECIALLY
NORTH OF I80. WITH PLENTY OF DRIED VEGETATION AND AFTERNOON RH/S
DIPPING INTO THE LOWER 40S TO 30 PERCENT RANGE...A GRASSLAND FIRE
DANGER MAY EVOLVE BY WED AFTERNOON. A LOW CHC FOR MORE WRAP AROUND
LIGHT RAIN ALONG AND NORTH OF HWY 20 ON WED. IF WRAP AROUND PRECIP
MAINTAINS IN THE NORTHERN CWA INTO WED NIGHT-EARLY THU MORNING BY
BLOCKED GRT LKS CYCLONE...SOME PRECIP TYPE ISSUES MAY HAVE TO BE
DEALT WITH. BUT MORE MODELS ARE DRY WED NIGHT THAN ARE ADVERTISING
THIS POTENTIAL.
THURSDAY AND FRIDAY... BLOCKED GRT LKS CYCLONE WILL LOOK TO FILL
SOME...THEN DRIFT BACK SOUTHWARD AS AN UPPER TROF DOWN THE WESTERN
GRT LKS AND UPPER MS RVR VALLEY. IF THIS PANS OUT...THEN POSSIBLY
SOME SHOWER ACTIVITY MAY DEVELOP IN THE VCNTY OF THIS FEATURE BY THU
AFTERNOON ESPECIALLY ALONG AND NORTH OF I80. EXPECT IF THIS
OCCURS... ANY LINGERING SHOWERS TO DIURNALLY WANE THU NIGHT. BUT IF
THEY PERSIST LONGER INTO THE NIGHT THAN CURRENTLY EXPECTED...PRECIP
TYPE ISSUES WILL POPS UP AGAIN WITH RAIN-SNOW MIX OR EVEN ALL WET
SNOW SHOWERS ESPECIALLY NORTH OF I80. THE SOUTHWARD DRIFTING TROF
WILL KEEP THE CHC FOR ISOLATED TO WDLY SCTRD SHOWERS GOING FRI INTO
FRI NIGHT...ALTHOUGH THE NEW 12Z ECMWF AS BACKED OFF OF THIS
POTENTIAL AND IS MAINLY DRY INTO EARLY SAT MORNING. AGAIN ANY
LINGERING NOCTURNAL PRECIP MAY HAVE A CHANCE TO GO INTO A WINTRY MIX
ESPECIALLY NORTH OF I80. HIGHS THU IN THE MID 40S NORTH...TO THE MID
50S IN THE SOUTH...THU NIGHT LOWS WELL DOWN IN THE 30S ESPECIALLY
WITH ANY CLOUD DECREASE. FRI HIGHS CONTINUE TO TREND COOLER IN THE
40S TO AROUND 50.
SATURDAY THROUGH NEXT MONDAY...MUCH WILL DEPEND ON PLACEMENT OF
DEVELOPING COLD CORE UPPER TROF THIS PERIOD...WITH HIGHS POSSIBLY
HELD WELL DOWN IN THE 40S BOTH SATURDAY AND SUNDAY. SCTRD SNOW OR
RAIN SHOWERS POSSIBLE UNDER THIS FEATURE ON SAT AS WELL WITH SUCH
COLD VERTICAL PROFILES JUST ALOFT. THE 12Z GFS IS DRY ON SUNDAY WITH
UPPER TROF AXIS TO THE EAST OF THE AREA...WHILE THE ECMWF MAINTAINS
SOME COLD SHOWERS ESPECIALLY EAST OF THE MS RVR. WILL KEEP A DRY
FCST FOR NOW THROUGH MON. LONGER RANGE INDICATIONS SHOW A WARMING
TREND EARLY NEXT WEEK...BUT THE LEADING EDGE MAY BE ACCOMPANIED BY A
LEAD CLIPPER WITH A PRECIP WING EITHER MON OR EARLY TUE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1133 PM CDT MON MAR 14 2016
VFR TO MOSTLY VFR CONDITIONS OVERNIGHT AT ALL TERMINALS AHEAD OF A
DEVELOPING STORM SYSTEM IN THE PLAINS. SOUTHEAST WINDS OF 5 TO 10 KTS
NEXT 12-18 HOURS. AFTER 15/11Z...CLOUDS TO INCREASE WITH PATCHY MVFR
CONDITIONS IN RAINSHOWERS AND ISOLATED STORMS UNTIL 15/16Z. THEN...MOSTLY
VFR CONDITIONS WITH ISOLATED SHOWERS AND STORMS UNTIL 15/21Z THEN AREAS
OF SHOWERS AND STORMS WITH MVFR AND POSSIBLY IFR CONDITIONS WITH SOME
STRONG AND SEVERE STORMS WITH HAIL THE MAIN THREAT THROUGH 16/02Z. AFTER
16/02Z...RAIN AND STORMS AND MVFR/IFR CONDITIONS AND WINDY WEST WIND
AT CID/DBQ BEHIND STRONG LOW. AT MLI/BRL...VFR OR MOSTLY VFR WITH A
CHANCE OF LIGHT RAIN AND ALSO BREEZY TO WINDY WITH A WESTERLY WIND.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...08
SHORT TERM...08
LONG TERM...12
AVIATION...NICHOLS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
522 AM EDT TUE MAR 15 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 517 AM EDT TUE MAR 15 2016
WV IMAGERY AND RAP ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM
ALBERTA/SASK INTO THE WRN PLAINS WITH DOWNSTREAM RIDGING FROM THE
WRN GREAT LAKES INTO NW ONTARIO. AT THE SFC...SE FLOW WAS
INCREASING OVER THE MS VALLEY BETWEEN A RIDGE OVER THE WRN LAKES AND
A TROUGH FROM SRN MANITOBA THROUGH THE ERN DAKOTAS TO LOW PRES OVER
ERN KS. SHRA/TSRA OVER SRN MN INTO IA WERE SUPPORTED BY STRONG LOW
LEVEL MOISTURE INFLOW AND ISENTROPIC LIFT AHEAD OF THE TROUGH. EVEN
WITH THE RIDGE OVER UPPER MI...CLOUDY SKIES PREVAILED WITH TEMPS
WELL ABOVE NORMAL FROM THE UPPER 30S TO AROUND 40.
TODAY...AS THE 120 KNOT 250-300 MB JET INTO THE GREAT BASIN AND
CNTRL ROCKIES MOVES INTO THE PLAINS THE MID LEVEL TROUGH WILL
STRENGTHEN AND THE SFC LOW MOVING INTO SE IA WILL DEEPEN. THE STRONG
DYNAMICS SUPPORTING THE UPSTREAM PCPN WILL GRADUALLY MOVE TOWARD
UPPER MI BUT SHOULD REMAIN TO THE SOUTH AND WEST TIL THIS AFTERNOON
WHEN SOME PCPN MAY MOVE INTO THE WEST.
TONIGHT...AS THE STACKED LOW GRADUALLY LIFTS TO THE NE THE SFC LOW
IS EXPECTED TO DEEPEN TO NEAR 985 MB OVER SRN WI. THE GFS/NAM HAVE
CONTINUED TO TREND SLOWER WITH THE ARRIVAL OF THE LARGE PCPN BAND IS
IN BETTER AGREEMENT WITH THE MORE CONSISTENT ECMWF. SO...EXPECT THE
BULK OF THE HEAVIER PCPN TO ARRIVE AFTER 06Z AND REACH THE NORTH AND
EAST PORTIONS OF THE CWA TOWARD 12Z. THERMAL PROFILES AND FCST
SOUNDINGS SUGGEST THAT WITH THE WAA SURGE...THE PCPN WILL REMAIN AS
RAIN TONIGHT. ERLY WINDS WILL ALSO BECOME GUSTY LATE
TONIGHT...ESPECIALLY OVER THE KEWEENAW AND NEAR LAKE MI WHERE GUSTS
OVER 35 MPH ARE EXPECTED.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 416 AM EDT TUE MAR 15 2016
...EXTENT OF SNOW LATER WED INTO THU IS MAIN FOCUS...
TROUGH ALOFT WITH TWO DISTINCT SHORTWAVES EXPECTED LATE TONIGHT INTO
WED MORNING WESTERN CANADA TO WESTERN GREAT LAKES. LEAD SHORTWAVE/PV
ANAMOLY CROSSES INTO LOWER MICHIGAN WED MORNING. OTHER MAIN SHORTWAVE
OVER SOUTHERN SASKATCHEWAN SHEDS SOME ENERGY TOWARD THE WESTERN
GREAT LAKES SHORTWAVE AND THIS DEEPENS A TROUGH OVER UPPER GREAT
LAKES WED INTO THU. AT THE SFC...MAIN SFC LOW LATE TONIGHT INTO WED
MORNING WILL BE OVER WESTERN WI WITH WARM FRONT CNTRL WI TO CNTRL
LOWER MI. LOW ONLY DEEPENS ACROSS WI AS TROUGH ALOFT DEEPENS. SOLN
IS QUITE DIFFERENT THAN LOOKED LIKE 1-2 DAYS AGO WHEN THE LOW WAS
SUPPOSED TO LIFT ACROSS UPR MICHIGAN AND ON TO THE EAST. SOLN DOES
LOOK LIKE THE ECMWF IDEA FM A COUPLE DAYS AGO....ESPECIALLY WITH
REGARD TO SFC LOW POSITION AT 12Z WED.
SURGE OF RAIN SHOWERS...WITH POSSIBLE EMBEDDED CONVECTIVE ELEMENTS
IF NOT A FEW LIGHTNING STRIKES WILL BE SUPPORTED BY SHARP H85 THETA-
E RIDGE/ISENTROPIC ASCENT AND THETA-E ADVECTION. SI/S STAYING MOSTLY
ABOVE 0C AND AXIS OF ELEVATED CAPE STAYING OVER LOWER MI SHOULD
LIMIT COVERAGE AND NORTHWARD EXTENT OF TSRA ON WED MORNING. WILL
KEEP SLIGHT CHANCE FAR SCNTRL. THOUGH WARM AIR ADVECTION LEADS TO
STABLE TEMP PROFILE SFC-H7...CONCERNED WITH 50-60 KT H9-H8 WINDS
THAT COULD BE MIXED AT LEAST PARTIALLY TO SFC IN STRONGER CONVECTIVE
ELEMENTS OR IF THERE ARE TSRA. RAIN WILL BE FALLING HEAVILY SO
PRECIP LOADING COULD ALSO AID IN BRINGING STRONG/GUSTY WINDS TO SFC.
AT THE LEAST...DUE TO INCREASING PRESSURE GRADIENT TO NORTH OF
DEEPENING SFC LOW OVER WI DOWN TO LESS THAN 990MB BY 12Z WED...AREAS
FAVORED BY EAST WINDS SUCH AS LK MICHIGAN/BAY OF GREEN BAY AND
ACROSS KEWEENAW COULD SEE EAST WINDS GUSTING TO 30-40 MPH MUCH OF
THE DAY. AS THETA-E RIDGE GETS PINCHED OFF INTO WED AFTN WELL EAST
OF UPR MICHIGAN...FORCING FOR PRECIP WILL DIMINISH. ONLY EXCEPTION
IS OVER WESTERN CWA WHERE DEEP LAYER Q-VECTOR CONVERGERNCE EXPANDS
ON NW SIDE OF DEEPENING UPPER LOW AND STRONG SFC-H85 LOW MEANDERING
OVER NORTHERN WI AND PERHAPS AS FAR NORTH AS SCNTRL UPR MICHIGAN.
PTYPE REMAINS A CHALLENGE. ACCUMULATING SNOW IS A STRONG
POSSIBILITY...BUT EXTENT OF MODERATE OR EVEN HEAVY SNOW IS NOT AS
CERTAIN. KEWEENAW STILL IN LINE TO MIX WITH AND CHANGE TO SNOW ON
WED AS IS FAR WESTERN UPR MICHIGAN VCNTY OF KIWD. THEMAL PROFILE
DIFFERENCES ARE MOST NOTABLE ON WED MORNING. NAM SHOWS H85 TEMPS +5C
WHILE THE GFS IS -4C THOUGH NOT SATURATED AT THAT POINT. NAM
CONTINUES TO LINGER WARM AIR ALOFT H8-H7 LEADING TO SLEET OR FZRA
WHILE GFS COOLS SUFFICIENTLY FOR SNOW. DRYING ALOFT MAY CUT OUT OR
AT LEAST DIMINISH PRECIP IF NAM IS RIGHT BY MIDDAY. GEM-REGIONAL
LOOKS MORE LIKE THE NAM AND WPC PROBABILISTIC FORCASTS WOULD SUPPORT
GREATER CHANCES OF ACCUMULATING SNOW OVER FAR WEST CWA LATER WED
AFTN INTO WED NIGHT. AFTER ALL WAS SET AND DONE...AT LEAST WITH THIS
TURN IN THE MODELS...HAVE MODERATE SNOW AMOUNTS OF 3 TO 5 INCHES
OVER FAR WEST AND HIGHER TERAIN OF KEWEENAW WED THROUGH THU.
HEADLINE MAY BE NEEDED EVENTUALLY...BUT SINCE MOST OF SNOW ACCUMS
WILL NOT OCCUR UNTIL WED NIGHT AND THU...GOING TO GO WITH SPS ATTM.
LATEST WPC PROBABILITIES INDICATE 50-60 PCT CHANCE OF SEEING 6
INCHES OF SNOW IN 24 HOURS AT KIWD WITH SLIGHTLY LOWER PROBABILITIES
OF SEEING THAT MUCH OVER THE KEWEENAW AND HIGHER TERRAIN OF
BARAGA/MARQUETTE COUNTIES.
LATER THU INTO FRI...UPPER LOW UNRAVELS OVER THE UPPER GREAT LAKES
AND SFC LOW WEAKENS TO OVER 1000MB. DRY AIR MOVES IN FROM NORTHERN
ONTARIO AS SFC HIGH BUILDS SOUTHWARD. EXPECT LIGHT SNOW SHWOERS TO
FADE AWAY BY FRI...BUT IT WILL REMAIN SEASONABLY COOL WITH HIGHS IN
THE MID 30S NORTH TO AROUND 40 OVER SCNTRL. ANOTHER MORE PROGRESSIVE
UPPER LOW SLIDES OVER GREAT LAKES THIS WEEKEND AND NW FLOW BECOMES
ESTABLISHED ALOFT IN WAKE OF THAT FEATURE INTO EARLY NEXT WEEK.
SHORTWAVE TROUGH COMING THROUGH LATE IN THE WEEKEND COULD BRING SOME
LIGHT SNOW. TURNS PRETTY CHILLY BY EARLY NEXT WEEK...MAYBE EARLIER
PER GFS...WITH H85 TEMPS DOWN TO AROUND -15C. COULD SEE INTERMITTENT
LIGHT SNOW SHOWERS OFF LK SUPERIOR AS THE COLD AIR MOVES ACROSS
HELPED ALONG BY ANY SHORTWAVES DROPPING THROUGH. COOL WEATHER
PATTERN WILL CONTINUE THROUGH MUCH OF NEXT WEEK AS POSSIBLY LONGER
AS GFS/ECMWF ARE NOW TRENDING TOWARD MORE TROUGHING AND COLD AIR
HEADING TOWARD THE EASTER HOLDIAY WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 122 AM EDT TUE MAR 15 2016
A PATCH OF LLVL DRY AIR THAT HAS MOVED OVER UPR MI WL MAKE FOR A
CHALLENGING AVIATION FCST DURING A PERIOD OF NOCTURNAL COOLING. THIS
DRY AIR AND SOME VFR CLDS HAVE ALLOWED FOR BETTER THAN EXPECTED
CONDITIONS. BUT WITH SOME COOLING...STILL EXPECTING MVFR CONDITIONS
AT IWD AND CMX...WITH IFR PSBL AT SAW TOWARD 12Z WITH A BIT MORE OF
AN UPSLOPE ESE WIND. A STRENGTHENING ELY FLOW ON TUE AHEAD OF DVLPG
LO PRES IN MN WL TAP SOME DRIER AIR AND RESULT IN IMPROVING
CONDITIONS TO VFR MAINLY AT SAW...BUT THIS DRY AIR COULD REACH CMX
AND IWD AS WELL...RESULTING IN VFR WX FOR AT LEAST A TIME...AND
DELAY THE ARRIVAL OF RA AHEAD OF THE MN LO PRES. AS THE RA AHEAD OF
THE MN LO ARRIVES IN THE EVNG...EXPECT CONDITIONS TO DETERIORATE
SLOWLY.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 517 AM EDT TUE MAR 15 2016
AS A DEEP LOW PRESSURE SYSTEM LIFTS INTO UPPER MICHIGAN STRONG EAST
WINDS WILL DEVELOP. THE STRONGEST WINDS FOR THIS FORECAST PERIOD ARE
EXPECTED LATE TUESDAY NIGHT INTO EARLY THU WHERE EAST GALES OF 35 TO
45 KNOTS ARE EXPECTED AND A GALE WARNING IS IN EFFECT.
OTHERWISE...WINDS AT OR BELOW 25 KNOTS ARE EXPECTED FROM THU NIGHT
THROUGH SATURDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 4 AM TO 8 PM EDT WEDNESDAY FOR LSZ267.
GALE WARNING FROM 4 AM WEDNESDAY TO 4 AM EDT THURSDAY FOR LSZ265-
266.
GALE WARNING FROM 4 AM EDT /3 AM CDT/ WEDNESDAY TO NOON EDT /11
AM CDT/ THURSDAY FOR LSZ162-263-264.
LAKE MICHIGAN...
GALE WARNING FROM 5 AM TO 2 PM EDT WEDNESDAY FOR LMZ221-248-250.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...KC
MARINE...JLB
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
423 AM CDT TUE MAR 15 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 407 AM CDT TUE MAR 15 2016
EARLY MORNING WATER VAPOR IMAGERY DEPICTS A TRANSIENT SHORTWAVE
TROUGH OVER THE CENTRAL ROCKIES. THIS FEATURE...FORECAST TO
STRENGTHEN TODAY AND BECOME NEGATIVELY TILTED TONIGHT...WILL BE THE
MAIN DRIVER IN THE WEATHER THIS WEEK. THE RELATED SURFACE LOW LIES
JUST TO THE WEST OF THE AREA EARLY THIS MORNING...AND WILL PUSH
ACROSS THE AREA TONIGHT INTO WEDNESDAY. AVAILABLE MOISTURE FOR
PRECIPITATION IS CERTAINLY NOT A QUESTION FOR THIS EVENT...NOR IS
FORCING OR DYNAMICS. HAVE INCLUDED 80-100 PERCENT POPS FOR
CENTRAL/SOUTH CENTRAL MN AND WEST CENTRAL WI TODAY AND TONIGHT.
PRECIPITABLE WATER VALUES INCREASE TO AROUND ONE INCH BY THIS
AFTERNOON. GIVEN THE PROLONGED PERIOD OF LIFT FORECAST OVER EAST
CENTRAL MN AND WEST CENTRAL WI...PRECIP AMOUNTS IN THE ONE TO TWO
INCH RANGE LOOK REASONABLE ALONG/EAST OF THE INTERSTATE 35 CORRIDOR
BY 12Z WEDNESDAY...WITH HIGHER ISOLATED TOTALS AROUND 3 INCHES WHERE
THUNDERSTORMS BRING BURSTS OF HEAVIER RAIN.
ALSO OF NOTE WILL BE THE WINDS...AS THE SURFACE LOW DEEPENS TO
AROUND 985MB BY 12Z WEDNESDAY. SUSTAINED 20-25 KTS WITH GUSTS TO 35
KTS APPEAR LIKELY LATE TONIGHT INTO WEDNESDAY MORNING...BUT THAT IS
ONLY THE BEGINNING OF STRONGER WINDS TO COME /SEE LONG TERM DISCUSSION/.
ADDITIONALLY...TEMPERATURES WILL NOT TRAVEL FAR FROM THEIR DAYBREAK
VALUES IN THE UPPER 40S/50S...GIVEN THE PERSISTENT LOW CLOUDS AND
ELEVATED DEWPOINTS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 407 AM CDT TUE MAR 15 2016
SUN WILL BE HARD TO COME BY IN THE EXTENDED PERIOD. TEMPERATURES
WILL BE NEAR THE SEASONAL AVERAGE FOR MID MARCH...BUT EXPECT
OVERCAST SKIES AND PERIODS OF LIGHT RAIN OR SNOW SHOWERS. THE
BIGGEST CONCERN ARE THE WINDS ON WEDNESDAY MORNING AS THE SURFACE
LOW DEEPENS TO THE EAST. FORECAST SOUNDINGS OFF THE GFS SHOW MID
60KT WINDS ATOP THE CHANNEL AT H800. ALTHOUGH THESE EXACT VALUES
WONT HAPPEN...IT DOES INDICATE THE EXTREME POWER WITH THIS
SYSTEM. GIVEN THE OVERALL SET UP WITH THE UPPER LEVEL JET FORCING
DOWN TO THE SURFACE CYCLONE INTENSIFICATION...DECIDED A HIGH WIND
WATCH WAS WARRANTED. THE STRONGEST WINDS WILL DEPEND ON WHERE THE
SURFACE LOW TRACKS. EVENTUALLY THE PRECIPITATION WILL CHANGE OVER
TO SNOW...AND COULD SEE A COUPLE OF INCHES ACROSS THE NORTHERN
COUNTIES LATE WEDNESDAY INTO THURSDAY.
A LOOK AT THE UPPER LEVEL JET ON THE NORTH AMERICAN PROJECTION
SHOWS THE TRANSITION FROM A FAST ZONAL FLOW TO A SERIES OF CUTOFF
HIGHS AND LOWS BY FRIDAY. THIS MEAN A SLOW DOWN IN THE WEATHER
PATTERN. IN PARTICULAR...THE UPPER MIDWEST WILL SEE A PROLONGED
PERIOD OF LOW CLOUDS AND OCCASIONAL RAIN OR SNOW SHOWERS AS AN
EASTERLY JET AT 300MB IS EXPECTED THURSDAY INTO FRIDAY. CLOUDY
COOL WEATHER WILL LAST AT LEAST THROUGH THE WEEKEND.
BEYOND THAT FORECAST MODELS TRY TO BRING A MORE PROGRESSIVE
WEATHER PATTERN...BUT HAVE LITTLE FAITH IN THE FORECAST FOR EARLY
NEXT WEEK SO CONTINUED WITH THE BLENDED GUIDANCE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1047 PM CDT MON MAR 14 2016
SEVERAL CONCERNS WITH THE OVERNIGHT FORECAST. FIRST...POCKETS OF
VFR CEILINGS HAVE DEVELOPED FROM KMSP ON WEST AND SOUTH THIS
EVENING. THERE ARE INDICATIONS USING THE 0.5KM CONDENSATION
PRESSURE DEFICITS FROM THE NAM AND RAP THAT A LARGE AREA OF VFR
CEILINGS COULD DEVELOP ACROSS CENTRAL AND SOUTHERN MN BY 09Z AND
PERSIST THROUGH 12Z. THIS DOES NOT SHOW UP IN THE MDL LAMP
PROBABILITIES WHICH KEEPS THE SITES MVFR OR LESS. SIDED MORE WITH
THE MDL LAMP PROBABILITIES FOR THE 06Z TAFS MAINLY DUE TO THE VERY
MOIST LOW LEVEL CONDITIONS WITH ANOMALOUSLY HIGH TEMPERATURES AND
DEW POINTS IN THE 50S AS WE APPROACH MIDNIGHT IN THE MIDDLE OF
MARCH. THEREFORE...DELAYED THE DROP TO IFR BY A FEW HOURS BUT
STILL HAVE HIGH CONFIDENCE IT WILL DEVELOP LATER IN THE NIGHT.
SHOWERS ARE SPREADING INTO WESTERN MN ON SCHEDULE AND THESE WILL
EXPAND DURING THE OVERNIGHT AND ON TUESDAY. THERE REMAINS A CHANCE
FOR SOME THUNDERSTORMS AS WELL OVERNIGHT. SEVERAL SHORT TERM
SOLUTIONS POINT TO THE TWIN CITIES IN THE 08Z-12Z TIME FRAME AND
FROM 10Z-14Z FOR KRNH AND KEAU. VCTS WAS INSERTED. SOUTHEAST WINDS
OVERNIGHT AND EARLY TUESDAY AT 10 KNOTS OR LESS WILL BECOME NW
TUESDAY AFTERNOON AND EVENING WITH SPEEDS INCREASING TO 15-20
KNOTS WITH GUSTS 25-30 KNOTS BY LATE TUESDAY NIGHT.
KMSP...ALLOWED FOR A LITTLE FLUCTUATION IN THE CEILING ABOVE AND
BELOW 030 AT THE START OF THE TAF WITH A DOWNWARD TREND TO IFR BY
12Z. ALSO INCLUDED VCTS IN THE 08Z-12Z TIME FRAME.
/OUTLOOK FOR KMSP/
WED...MVFR WITH CHC OF IFR CIGS/-RA. WIND W 15-20G30KTS.
THU...MVFR WITH CHC OF IFR CIGS/-RA/-SN. WIND N 10 KTS.
FRI...VFR. WIND NNE 6KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...HIGH WIND WATCH FROM LATE TONIGHT THROUGH WEDNESDAY AFTERNOON
FOR MNZ083>085-091>093.
&&
$$
SHORT TERM...LS
LONG TERM...JRB
AVIATION...RAH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1234 AM CDT TUE MAR 15 2016
.UPDATE...
ISSUED AT 1233 AM CDT TUE MAR 15 2016
THIS UPDATE REFINED POPS FOR SHOWERS AND ISOLATED THUNDERSTORMS
OCCURRING MAINLY EAST OF A LINE FROM MINOT TO BISMARCK. MORE
NUMEROUS SHOWERS CONTINUED IN THE TURTLE MOUNTAIN AND DEVILS LAKE
BASIN...WHILE SCATTERED SHOWERS AND THUNDERSTORMS CONTINUED FARTHER
SOUTH IN THE JAMES BASIN AREA. THE COLD FRONT EXTENDED FROM A LOW
OVER SOUTHWESTERN MANITOBA TO NEAR DEVILS LAKE TO JAMESTOWN TO NEAR
ABERDEEN IN SOUTH DAKOTA...AND WILL CONTINUE MOVING EASTWARD THIS
MORNING. SHOWERS SHOULD END FROM WEST TO EAST AND BE OUT OF THE
JAMES RIVER VALLEY BY/BEFORE SUNRISE. COOLER AIR WAS ALREADY PUSHING
INTO THE STATE...WITH LOWER 30S IN THE WEST AT MIDNIGHT CDT.
UPDATE ISSUED AT 918 PM CDT MON MAR 14 2016
THIS UPDATE FOCUSED ON REFINING POPS FOR THE SHOWERS AND ISOLATED
THUNDERSTORMS THAT ARE OCCURRING ALONG AND AHEAD OF THE COLD FRONT
THAT IS JUST EAST OF THE HIGHWAY 83 CORRIDOR AS OF 02 UTC. WE USED
TIME-LAGGED HRRR GUIDANCE TO ADJUST POPS OVERNIGHT SINCE IT PICKS
UP ON RADAR TRENDS AS OF MID EVENING...WITH DRYING OVER WESTERN ND
IN THE POST-FRONTAL AIR MASS SPREADING EAST OVERNIGHT. THE 00 UTC
ABERDEEN SOUNDING SAMPLED A MODERATELY UNSTABLE AIR MASS WHICH THE
RAP-BASED SPC MESOANALYSIS SUGGESTS EXTENDS INTO EAST CENTRAL ND
WHERE SURFACE DEWPOINTS ARE BETWEEN 45 AND 50 F THIS EVENING...BUT
IT APPEARS EFFECTIVE SHEAR LESS THAN 30 KT IS LIMITING THE CHANCE
OF SUSTAINED STRONG UPDRAFTS.
UPDATE ISSUED AT 604 PM CDT MON MAR 14 2016
WE INCREASED POST-FRONTAL NORTHWEST WIND SPEEDS OVER WESTERN AND
PARTS OF CENTRAL ND THIS EVENING WITH THIS UPDATE GIVEN UPSTREAM
PRESSURE RISES...OTHERWISE ONLY MINOR CHANGES WERE MADE.
AS OF 23 UTC...CONVECTION IS DEVELOPING OVER CENTRAL ND WITH A
WELL-DEFINED THUNDERSTORM SOUTHWEST OF MINOT...AND RECENT VISIBLE
SATELLITE IMAGERY SHOWS AGITATED CUMULUS FURTHER SOUTHWARD ACROSS
PARTS OF BURLEIGH AND EMMONS COUNTIES AS WELL. LOW-LEVEL MOISTURE
ACTUALLY MIXED OUT WITH LOWERING DEWPOINTS ALONG THE HIGHWAY 83
CORRIDOR LATE THIS AFTERNOON...REDUCING INSTABILITY...BUT STEEP
MID-LEVEL LAPSE RATES ARE STILL SUFFICIENT FOR CONVECTIVE GROWTH.
RAP-BASED MESOANALYSIS OUTPUT SUGGESTS GREATER MLCAPE UP TO AROUND
1000 J/KG IS POSSIBLE EAST OF HIGHWAY 83 AND SOUTH OF HIGHWAY 2
THIS EVENING IF SURFACE DEWPOINTS OVER 45 F ARE MAINTAINED AHEAD
OF THE DEVELOPING CONVECTION...SUGGESTING A STRONG STORM OR TWO
COULD OCCUR.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 341 PM CDT MON MAR 14 2016
CURRENT SURFACE ANALYSIS PLACES LOW OVER SOUTHERN MANITOBA WITH
COLD FRONT DROPPING DOWN NEAR THE MONTANA/NORTH DAKOTA BORDER.
UPPER LEVEL ANALYSIS PLACES TROUGH OVER THE ROCKIES WITH RIDGE
OVER THE UPPER MIDWEST STRETCHING TOWARDS THE
SASKATCHEWAN/MANITOBA BORDER. SHORTWAVE WORKING TOWARDS THE
NORTHERN PLAINS CONTINUES TO PRODUCE PRECIPITATION OVER EASTERN
MONTANA...WHILE A LOW IS STARTING TO CLOSE OFF OVER FAR
SOUTHEASTERN ALBERTA.
FOR THE REST OF THIS AFTERNOON INTO TONIGHT...AFOREMENTIONED
CLOSING OFF SURFACE LOW WILL SHIFT OVER SOUTHERN SASKATCHEWAN
OVERNIGHT WHILE COLD FRONT/SURFACE LOW PUSH OVER NORTH DAKOTA.
THIS WILL BRING A BROAD SWATH OF RAIN SHOWERS OVER THE AREA. AHEAD
OF THE SURFACE LOW/COLD FRONT MOISTURE/INSTABILITY WILL BE ON THE
INCREASE WITH SOUTH/SOUTHEASTERLY LOW LEVEL FLOW...SO A FEW
AFTERNOON/EVENING THUNDERSTORMS WILL NOT BE OUT OF THE QUESTION.
ON TUESDAY...SOME SHOWERS MAY LINGER OVER THE EAST FOR A BIT IN
THE MORNING...OTHERWISE THE DAY SHOULD START OUT QUIET. WINDS WILL
BE ON THE INCREASE THROUGH THE MORNING IN THE WAKE OF THE
DEPARTING SURFACE LOW/COLD FRONT. MODEST COOL AIR ADVECTION BEHIND
THE DEPARTING SYSTEM WILL BRING NOTABLY COOLER CONDITIONS...WITH
HIGHS AROUND 50. UPPER LOW OVER SASKATCHEWAN GRADUALLY MOVES TO
THE EAST/SOUTHEAST WITH THE NEXT SHORT WAVE SWINGING AROUND INTO
THE AREA IN THE AFTERNOON...BRINGING CHANCES FOR SHOWERS TO THE
FAR WEST.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 341 PM CDT MON MAR 14 2016
MUCH COOLER TEMPERATURES AND MORE ACTIVE WEATHER IS THE MAIN
HIGHLIGHTS FOR THE LONG TERM FORECAST PERIOD.
MODELS REMAIN IN VERY GOOD AGREEMENT WITH A NEGATIVELY TILTED
UPPER LEVEL TROUGH FORMING OVER THE NORTHERN PLAINS AND STALLING
OVER THE REGION INTO EARLY WEDNESDAY. WRAP AROUND MOISTURE AND
CAA MOVING NORTH TO SOUTH TUESDAY NIGHT AND ONWARDS AS A CUTOFF
LOW FORMS AND SLOWLY PIVOTS SOUTHWARD THROUGH THE REGION.
PROLONGED PERIOD OF PRECIPITATION IS BEING ADVERTISED BY MOST
MODELS AS A TROWAL/DEFORMATION ZONE SETS UP...INITIALLY AS A
RAIN/SNOW MIX THEN ALL SNOW AS COLDER AIR PUSHES ACROSS THE STATE.
STILL A DECENT AMOUNT OF UNCERTAINTY ALTHOUGH CHANCE TO LIKELY
POPS REMAIN WARRANTED.
SOME AREAS WILL SEE 1 TO 4 INCHES OF SNOW POSSIBLE THROUGH FRIDAY
WHILE OTHER LOCATIONS LESS. STILL SOME UNCERTAINTY AS THERE IS
STILL MID/UPPER LEVEL ENERGY YET TO MOVE ONSHORE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1233 AM CDT TUE MAR 15 2016
A COLD FRONT THAT IS NEAR A KJMS TO KDVL LINE AT 06Z WILL CONTINUE
MOVING EAST THIS MORNING. SHOWERS AND ISOLATED THUNDERSTORMS AND
GUSTY AND ERRATIC SURFACE WINDS ARE POSSIBLE AHEAD
OF THE FRONT...INCLUDING AT KJMS THROUGH ABOUT 08Z. OTHERWISE...
VFR CONDITIONS ARE EXPECTED TO PREVAIL EARLY THIS MORNING AND LATER
ON TUESDAY WHEN DRYING NORTHWEST WIND GUSTS TO 30 KT ARE EXPECTED
ACROSS MUCH OF WESTERN AND CENTRAL ND.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JV
SHORT TERM...JJS
LONG TERM...NH
AVIATION...JV
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
131 AM EDT TUE MAR 15 2016
.SYNOPSIS... AN UPPER AIR DISTURBANCE CROSSING OVERNIGHT. COLD FRONT
EARLY WEDNESDAY MORNING. DRIER AIR/LOWERING DEW POINTS WEDNESDAY
AFTERNOON. WEAK MID LEVEL DISTURBANCE THURSDAY.
&&
.NEAR TERM /THROUGH TODAY/...
CONVECTION DEVELOPING TO OUR WEST...ASSOCIATED WITH UPPER LEVEL
SHORTWAVE TROUGH/VORTICITY LOBE OVER CENTRAL KY. MODELS SHOW THIS
FEATURE GRADUALLY LOSING STEAM AS IT CROSSES LATER THIS AFTERNOON
INTO TONIGHT. HAVE SOME UNSTABLE AIR IN PLACE ACROSS THE CWA THIS
AFTERNOON. CAPE LOOKS TO MAX OUT AT AROUND 1000 J/KG...BUT IS A
FAIRLY SKINNY PROFILE. HOWEVER...COMBINE THAT WITH A FREEZING
LEVEL AROUND 9000FT ABOVE GROUND LEVEL...SOME SMALL HAIL WOULD BE POSSIBLE IN
ANY TALLER STORMS. FLOW IS NOT OVERLY STRONG... 35-40KTS AT 700MB
AND 500MB... BUT WE DO HAVE A WEAK INVERTED V AND POCKET OF DRIER
AIR IN THE MID LEVELS PER FORECAST SOUNDINGS. THIS COULD LEAD TO
ISOLATED DAMAGING WIND GUSTS IN THE STRONGER CELLS. BULK SHEAR IS
ONLY MARGINAL -- AROUND 35KTS -- SO EXPECT INDIVIDUAL CELLS TO BE
RATHER UNORGANIZED AND MAYBE PULSE-Y IN NATURE.
WITH ALL THAT IN MIND...HAVE AN AREA OF HIGH POPS TRANSITIONING
ACROSS CWA FROM SW TO NE THIS AFTERNOON AND EVENING. RELIED FAIRLY
HEAVILY ON THE HI-RES NAM AND HRRR FOR TIMING OF THE HIGHEST POPS.
PRECIPITABLE WATER SHOULD BE 1-1.2 IN...WHICH SHOULD NOT CREATE
ANY WIDESPREAD PROBLEMS. HAVE ONGOING FLOOD WATCH ACROSS THE
NORTH. WITH MIDDLE ISLAND CREEK AND DUCK CREEK CONTINUING TO RUN
HIGH...AND A BULLSEYE OF LOW FLASH FLOOD GUIDANCE...WILL LEAVE THE
FLOOD WATCH AS IS. PRECIPITATION WILL BE COMING TO AN END FROM WEST TO
EAST TONIGHT...HOWEVER WITH NO COLD FRONT PUSHING THROUGH THE LOW
LEVEL MOISTURE REMAINS IN PLACE WHICH SHOULD LEAD TO LOW STRATUS
AND SOME VALLEY FOG BY EARLY TUESDAY MORNING.
USED A BLEND OF CONSENSUS GUIDANCE AND ECMWF MOS FOR HIGHS WHICH
DID NOT RESULT IN ANY REAL SIGNIFICANT CHANGES. A MAV/MET BLEND
FOR LOWS TONIGHT TRENDED A TOUCH WARMER THAN PREVIOUS FORECAST.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY/...
MID LEVEL DYNAMICS IN THE MIDWEST...IOWA AND ILLINOIS...NEAR 00Z
WEDNESDAY LIFTS NORTHEAST TOWARD MICHIGAN BY 06Z AND AND EASTERN
GREAT LAKES BY 12Z WED. MEANWHILE 500 MB HEIGHTS ONLY FALL SLOWLY
HERE.
SO NOT IMPRESSED WITH SUPPORT AHEAD OF THE SURFACE FRONT. STILL
HAVE FRONT SWEEPING EAST. FIGURING REACHING TOWARD CRW AROUND 12Z
WEDNESDAY...THEN EXITING MOUNTAINS BY 15Z. DESPITE LACK OF
MID LEVEL SUPPORT...CONSIDERING AIR MASS WE ARE STILL IN...AHEAD
OF THE FRONT...WILL STILL LEAVE SOME 20 TO 40 POPS ASSOCIATED WITH
THE FRONT.
WESTERLY FLOW OF LOWERING DEW POINTS AND FRESHER AIR ADVECTING OUR
WAY...DURING THE DAY ON WEDNESDAY.
MID LEVEL DISTURBANCE IN FAST FLOW SOUTH OF THE CLOSED 500 MB LOW
OVER THE WESTERN GREAT LAKES FOR WEDNESDAY NIGHT INTO THURSDAY.
HAVE MID LEVEL MOISTURE INCREASING OVERNIGHT WEDNESDAY NIGHT. COULD
NOT RULE OUT SOME LIGHT RAIN LATE WEDNESDAY NIGHT INTO THURSDAY...BUT
AGAIN COULD NOT GO MORE THAN 20 TO 40 POPS.
CONSIDERING 850 TEMPERATURES ONLY AROUND PLUS 1 C...LOWERED MAXIMUM
TEMPERATURES AND EVEN MENTIONED A POSSIBILITY FOR THOSE POPS OF R-S-
AT OR ABOVE 4000 FEET.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
GENERALLY QUIET WX WILL GREET FOLKS ENDING THE WORK WEEK WITH
SEASONAL TEMPS. WE STILL ENVISION A PATTERN CHANGE HEADING INTO THE
WEEKEND WHICH WILL ESTABLISH A MEAN EASTERN US TROF THRU EARLY NEXT
WEEK. GLOBAL MODELS CONTINUE TO STRUGGLE WITH THE EVOLUTION OF THIS
AND MORE SPECIFICALLY IF A CONSOLIDATED LOW PRESSURE SYSTEM WILL
FORM ON SUNDAY. REGARDLESS...EXPECT SOME CHILLY RAIN SHOWERS WITH
MOUNTAIN SNOW SHOWERS ON SUNDAY.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
UPPER AIR DISTURBANCE MOVING OVER THE AREA WILL CONTINUE TO CREATE
SOME IFR/MVFR SHOWERS EARLY THIS MORNING. THIS DISTURBANCE WILL EXIT
OFF TO THE NORTHEAST THIS MORNING. AN MVFR STRATUS DECK MAY ALSO
FORM THIS MORNING OUTSIDE OF THE SHOWERS. THE STRATUS DECK WILL
GRADUALLY LIFT INTO A CUMULUS DECK ON TUESDAY. SKIES ARE EXPECTED TO
CLEAR AROUND SUNSET...AND REMAIN VFR THROUGH THE EVENING HOURS.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z WEDNESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING OF STRATUS FORMING EARLY THIS MORNING
COULD VARY. SCATTERED SHOWERS COULD CAUSE LOWER RESTRICTIONS EARLY
THIS MORNING. DUE TO THE SCATTERED NATURE OF THE SHOWERS...THESE
HAVE NOT BEEN TIMED IN THE TAFS.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE TUE 03/15/16
UTC 1HRLY 03 04 05 06 07 08 09 10 11 12 13 14
EDT 1HRLY 23 00 01 02 03 04 05 06 07 08 09 10
CRW CONSISTENCY H H H H M M M M M M M M
HTS CONSISTENCY H H M M M M M M M M M M
BKW CONSISTENCY M M M M M M M M M M M M
EKN CONSISTENCY M M M M M L L L L L L L
PKB CONSISTENCY M H H H M M M M M M M M
CKB CONSISTENCY M M M M M M M M M M M M
AFTER 06Z WEDNESDAY...
CHANCES FOR IFR CONDITIONS ARE LOW.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FLOOD WATCH UNTIL 6 AM EDT EARLY THIS MORNING FOR WVZ009>011-
017-019-020-031-032-040.
OH...FLOOD WATCH UNTIL 6 AM EDT EARLY THIS MORNING FOR OHZ066-067-
075-076-084.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...MZ/30/26
NEAR TERM...MZ
SHORT TERM...KTB
LONG TERM...30
AVIATION...RPY
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
529 AM EDT TUE MAR 15 2016
.SYNOPSIS...
AN UPPER TROUGH WILL FILL AND PUSH EAST OF THE AREA THIS MORNING.
HOWEVER...CLOUDS WILL PREVAIL OVER MUCH OF THE AREA THROUGH THE
DAY. A WARM FRONT WILL LIFT THROUGH THE STATE ON
WEDNESDAY...FOLLOWED VERY SHORTLY BY A COLD FRONT. COOLER AND
UNSETTLED CONDITIONS WITH SCATTERED RAIN SHOWERS WILL FOLLOW FOR
THE END OF THE WEEK AND INTO WEEKEND. THE RAIN SHOWERS LATE THIS
WEEK WILL MIX WITH WET SNOW...ESPECIALLY OVERNIGHTS ON THE
RIDGES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SHOWERS TRYING TO ENTER THE WESTERN COUNTIES AT 5 AM...BUT HAVING
MORE LUCK OVER THE SC MTNS. 00Z NAM AND MOST HRRR AND RAP RUNS UP
TO THIS POINT DID WELL AT PLACING PRECIP. BUT RECENT RUNS HAVE
BEEN LESS IMPRESSIVE. STILL A GENERALLY SHOWERY/DRIZZLY DAY IS
FORECAST AS THE WIND ONLY GRADUALLY BECOMES WESTERLY BEHIND THE
PASSAGE OF A VERY WEAK TROUGH. WILL MENTION PATCHY FOG/DZ INTO THE
MORNING...THEN JUST CALL IT SHOWERS. POPS WILL BE HIGHEST IN THE
MORNING DUE TO MORE CERTAINTY TRACKING CURRENT RADAR AND SAT
FEATURES. NEAT MCV VISIBLE IN THE RADAR DATA BACK AROUND MIDNIGHT
OVER THE WRN PART OF THE STATE AND NOW ONE IS ROLLING NORTHWARD
THROUGH THE SC MTNS...GENERATED BY CONVECTION OVER CENTRAL V
EARLIER TONIGHT. PRECIP SEEMS NOT SO CERTAIN AS HIGH PRESSURE
STARTS TO BUILD IN FROM THE WEST THROUGH THE DAY. HOWEVER...THE
NRN TIER WILL HAVE THE HIGHEST /CHC/ POPS IN THE AFTN. HAVE TAKEN
A FEW DEGS OFF THE MAX TEMPS OVER THE NRN AND CENTRAL MTNS FROM
PREV FCSTS AND MOS SINCE THE CLOUDS DO LOOK TOUGH TO SCOUR OUT.
WOULD NOT BE SURPRISED TO SEE THEM NEED TO BE ADJUSTED DOWNWARD A
NOTCH OR TWO LATER TODAY. BUT PEEKS OF SUN ARE STILL POSSIBLE -
MAINLY S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
HIGH PRESSURE SLIDES OVERHEAD TONIGHT...BUT LITTLE CHANGE IN SKY
COVER IS EXPECTED OVER THE NRN HALF OF THE AREA. THERE WILL LIKELY
BE SOME CLEARING IN THE SRN HALF...BUT IT WILL BE SHORT-LIVED AS A
WARM FRONT APPROACHES FROM THE SW LATER IN THE NIGHT. DIURNAL
SWING WILL BE VERY SMALL IN THE N - BUT CLOSER TO 10-12F OVER THE
SRN TIER. MOST PLACES WILL BOTTOM OUT IN THE M40S.
ENOUGH INSTABILITY MAY DEVELOP IN THE PARTIAL CLEARING WHICH COULD
OCCUR AHEAD OF THE WARM FRONT ON WED. SPC HAS US IN GENERAL
THUNDER - AND A QUICK LOOK AT THE HODOGRAPH AND VERY LOW LCLS IN
PROXIMITY TO THE WARM FRONT MAKE IT SEEM LIKE IT COULD BE MORE
INTERESTING /ROTATING CELLS??/ THAN A BENIGN MENTION OF T. 0-3KM
EHI/S START TO SHOW UP IN A NARROW STRIPE NEAR THE WARM FRONT.
HOWEVER...WE WILL PROBABLY BE LIMITED IN HEATING AND HAVE HIGHER
STABILITY THAN WHAT IT WOULD TAKE TO GENERATE DEEP CONVECTION AND
REALIZE THE POTENTIAL OF THE STORMS THAT DAY. WILL MENTION THUNDER
FOR WED. ANOTHER FEW RUNS WILL HELP DETERMINE JUST HOW UNSTABLE WE
CAN GET. THE COLD FRONT ZIPS RIGHT IN BEHIND THE OTHER
FRONT...AND COULD PROVIDE EXTRA LIFT AND DRY AIR. IT WILL ALSO
SERVE TO EFFECTIVELY CUT OFF PRECIP LATER IN THE DAY. MOST OF THE
SHOWERS WILL BE OFF TO THE EAST BEFORE SUNSET WED.
WED NIGHT IS A TOUGH CALL ON TEMPS AS THE SKY COVER WILL VARY
GREATLY THROUGH THE NIGHT WITH SOME INITIAL CLEARING THEN A RETURN
OF MOISTURE AND PERHAPS A SHOWER LATE AT NIGHT OVER THE WEST.
ALSO...THE WINDS BECOME SWRLY BEHIND THE COLD FRONT. 8H TEMPS INCH
DOWN THROUGH THE NIGHT. BUT THE DEW POINTS DO NOT GET OUT OF THE
WAY TO ALLOW FOR A REALLY GOOD TEMP DROP. OF COURSE...THE USUAL
COLD SPOTS IN THE EAST LIKE KSEG AND KTHV WHERE RADIATIONAL
COOLING SEEMS TO MAXIMIZED IN ALL SITUATIONS COULD DROP OFF
NICELY.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
THE INITIAL BLOCKING PATTERN OVER SRN CANADA AND THE NRN CONUS
WILL ULTIMATELY EVOLVE INTO A CNTRL-ERN U.S. MEAN TROUGH THAT
COULD SUPPORT A STRONGLY DEVELOPING SFC SYSTEM IN THE MID-ATLANTIC
AND NORTHEAST STATES THIS WEEKEND INTO MONDAY. THERE ARE STILL
IMPORTANT MODEL DIFFERENCES THAT REMAIN UNRESOLVED WITH INDIVIDUAL
ENSEMBLE MEMBERS VERY DISPERSED SUN-MON IN A LOW TRACK RANGING
FROM WELL INLAND TO OFFSHORE. THEREFORE THE DEGREE OF CERTAINTY OR
CONFIDENCE IN FORECAST DETAILS IS LOW/BELOW AVERAGE AT THIS TIME.
SENSIBLE WEATHER HIGHLIGHTS WILL BE A SEASONABLE COOLING TREND BY
THE END OF THE PERIOD FROM THE MID-WEEK PEAK/ANOMALOUS WARMTH.
THERE IS A LARGE SPREAD IN THE SFC LOW TRACK LATE IN THE PERIOD
WHICH TEMPERS CONFIDENCE IN DETERMINING PRECIP EXTENT/TIMING AND
TYPE. A LATE SEASON SNOW EVENT IS A POSSIBLE OUTCOME BUT THE ODDS
ARE VERY LOW AT THIS POINT.
&&
.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
06Z TAFS SENT.
A PATCH OF DRIZZLE MOVED ACROSS THE UNV AREA WHEN I CAME IN
EARLIER AND IS NOW JUST WEST OF IPT.
SHOWERS AND STORMS OVER OH JUST FELL APART. A FEW SHOWERS STILL
TRYING TO SURVIVE OVER N VA.
EARLIER DISCUSSION BELOW.
A MOIST LLVL EASTERLY FLOW IS PRODUCING WIDESPREAD IFR CIGS ACROSS
CENTRAL PA AS OF 03Z...WITH LIFR NOTED ACROSS THE HIGH TERRAIN
AIRFIELDS /KBFD AND KJST/. ONLY KIPT REMAINS MVFR...BUT BULK OF
MDL GUIDANCE INDICATES A BIT OF RADIATIONAL COOLING LIKELY CAUSE
CIGS TO DIP BLW 1KFT THERE FOR A TIME EARLY TUE AM.
EARLIER LINE OF TSRA FELL APART BEFORE REACHING CENTRAL PA...AS
ASSOC MID LVL DISTURBANCE WEAKENED AND LINE ENCOUNTERED A MORE
STABLE AIR MASS ACROSS PA.
SOME MODEST IMPROVEMENT TO WIDESPREAD MVFR CIGS WILL LIKELY OCCUR
BY TUES AFTERNOON...AS MOIST EASTERLY FLOW WEAKENS.
PARTIAL CLEARING...LIGHT WIND AND WET GROUND ASSOC WITH ARRIVAL
OF SFC RIDGE WILL LIKELY YIELD AREAS OF RADIATION FOG TUE NIGHT.
OUTLOOK...
WED...AM FOG POSSIBLE. ISOLD PM TSRA IMPACTS POSSIBLE.
THU...NO SIG WX EXPECTED.
FRI...SHSN/VIS REDUCTIONS POSS W MTNS.
SAT...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...STEINBUGL
AVIATION...FITZGERALD/MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
211 AM EDT TUE MAR 15 2016
.SYNOPSIS...
UPPER TROUGH DISSOLVES AS IT CROSSES THE AREA OVERNIGHT AND
HEIGHTS SHOULD RISE ON TUESDAY. HOWEVER...CLOUDS WILL KEEP IT A
BIT COOL. A WEAK COLD FRONT WILL CROSS THE STATE WEDNESDAY.
COOLER AND UNSETTLED CONDITIONS WITH A FEW RAIN SHOWERS WILL OCCUR
THURSDAY. THE SCATTERED RAIN SHOWERS WILL MIX WITH WET SNOW
FRIDAY.
&&
.NEAR TERM /UNTIL 9 AM THIS MORNING/...
130AM EDT UPDATE...
THINGS HAVE TOTALLY FALLEN APART OVER WRN PA - AND NEVER REALLY
MADE IT INTO THE CWA. OUR STABILITY HAS SQUASHED THE CONVECTION.
HAVE THUS DROPPED POPS CONSIDERABLY. STILL GOING TOO BE LOTS OF
DZ/LOW CLOUDS AROUND. SO HELD ONTO DZ/FG MENTIONS IN THE WX GRIDS
FOR THE ENTIRE NIGHT AND INTO THE FIRST HALF OF THE AM. SMALL
CHANGES TO THE NEXT FEW PERIODS BUT NOTHING MUCH TO MENTION AT
THIS POINT.
PREV...
LITTLE CHANGE LATE THIS EVENING...AS LLVL EASTERLY FLOW OF COOL
MOIST AIR HAS LOW CLOUDS LOCKED IN ACROSS THE ENTIRE FORECAST AREA
WITH WIDESPREAD LOW STRATUS..WITH FOG BLANKETING THE RIDGE TOPS.
SHOWERS OVER SOUTHWEST PA ARE STILL FORECAST TO DAMPEN AS PER
LATEST HI RES HRRR AND WRF ARW RUNS...RUNNING INTO THE COOL STABLE
AIR OVER CENTRAL AND EASTERN PA OVERNIGHT. HOWEVER...GIVEN THE
FORCING ARRIVING OVERNIGHT ASSOCIATED WITH THE 5H UPPER TROF...DO
EXPECT HIGH CHC TO LIKELY POPS TO IMPACT THE WEST CENTRAL AND
LAUREL HIGHLANDS BEFORE TAPERING FARTHER EAST. OVER THE CENTRAL
AND EAST...SHOWERS WILL BE MORE SCARCE...BUT DRIZZLE WILL BE
PREVALENT THROUGH EARLY TUESDAY MORNING.
LOWS TONIGHT WILL BE IN THE MID 30S...TO NEAR 40F IN THE LOWER
SUSQ REGION.
&&
.SHORT TERM /9 AM THIS MORNING THROUGH 6 PM WEDNESDAY/...
CLOUDS WILL CONTINUE TO HANG TOUGH ON TUESDAY AS PWATS REMAIN
ABOVE NORMAL AND THERE WILL BE VERY LITTLE PUSH OF DRY AIR TO
DISLODGE THE MOISTURE. WE SHOULD SEE TEMPERATURES REBOUND ABOVE
TODAY/S CHILLY READINGS HOWEVER...MAKING IT BACK INTO THE 50S. THE
CLOUDS ACROSS THE NRN TIER COULD KEEP THEM MORE NEAR 50F...BUT
BREAKS IN THE CLOUDS IN THE S WILL MAKE THEM CLOSE TO 60F.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
CONSENSUS OF GUIDANCE SHOWS AN AMPLIFIED SHORTWAVE TROUGH/CLOSED
500MB LOW PIVOTING NORTHWARD OVER THE UPPER MIDWEST AND WESTERN
GREAT LAKES REGION ON DAY 3/WED. A REX BLOCK FORMS BRIEFLY WITH A
CLOSED UPPER HIGH OVER MANITOBA. AT THE SURFACE...AN OCCLUDED LOW
IS FCST TO DRIFT N ACROSS WI WITH AN OCCLUDED COLD FRONT ARCING
DOWNSTREAM AND PUSHING E ACROSS THE APPALACHIANS/MID- ATLANTIC
STATES. MODELS GENERALLY AGREE IN GENERATING SHOWERS ALONG/AHEAD
OF THE OCCLUDED FRONT WITH SOME ELEVATED THUNDER POTENTIAL.
THE INITIAL BLOCKING PATTERN OVER SRN CANADA AND THE NRN CONUS
WILL ULTIMATELY EVOLVE INTO A CNTRL-ERN U.S. MEAN TROUGH THAT
COULD SUPPORT A STRONGLY DEVELOPING SFC SYSTEM IN THE MID-ATLANTIC
AND NORTHEAST STATES THIS WEEKEND INTO MONDAY. THERE ARE STILL
IMPORTANT MODEL DIFFERENCES THAT REMAIN UNRESOLVED WITH INDIVIDUAL
ENSEMBLE MEMBERS VERY DISPERSED SUN-MON IN A LOW TRACK RANGING
FROM WELL INLAND TO OFFSHORE. THEREFORE THE DEGREE OF CERTAINTY
OR CONFIDENCE IN FORECAST DETAILS IS LOW/BELOW AVERAGE AT THIS
TIME.
SENSIBLE WEATHER HIGHLIGHTS WILL BE A SEASONABLE COOLING TREND BY
THE END OF THE PERIOD FROM THE MID-WEEK PEAK/ANOMALOUS WARMTH.
THERE IS A LARGE SPREAD IN THE SFC LOW TRACK LATE IN THE PERIOD
WHICH TEMPERS CONFIDENCE IN DETERMINING PRECIP EXTENT/TIMING AND
TYPE. A LATE SEASON SNOW EVENT IS A POSSIBLE OUTCOME BUT THE ODDS
ARE VERY LOW AT THIS POINT.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
06Z TAFS SENT.
A PATCH OF DRIZZLE MOVED ACROSS THE UNV AREA WHEN I CAME IN
EARLIER AND IS NOW JUST WEST OF IPT.
SHOWERS AND STORMS OVER OH JUST FELL APART. A FEW SHOWERS STILL
TRYING TO SURVIVE OVER N VA.
EARLIER DISCUSSION BELOW.
A MOIST LLVL EASTERLY FLOW IS PRODUCING WIDESPREAD IFR CIGS ACROSS
CENTRAL PA AS OF 03Z...WITH LIFR NOTED ACROSS THE HIGH TERRAIN
AIRFIELDS /KBFD AND KJST/. ONLY KIPT REMAINS MVFR...BUT BULK OF
MDL GUIDANCE INDICATES A BIT OF RADIATIONAL COOLING LIKELY CAUSE
CIGS TO DIP BLW 1KFT THERE FOR A TIME EARLY TUE AM.
EARLIER LINE OF TSRA FELL APART BEFORE REACHING CENTRAL PA...AS
ASSOC MID LVL DISTURBANCE WEAKENED AND LINE ENCOUNTERED A MORE
STABLE AIR MASS ACROSS PA.
SOME MODEST IMPROVEMENT TO WIDESPREAD MVFR CIGS WILL LIKELY OCCUR
BY TUES AFTERNOON...AS MOIST EASTERLY FLOW WEAKENS.
PARTIAL CLEARING...LIGHT WIND AND WET GROUND ASSOC WITH ARRIVAL
OF SFC RIDGE WILL LIKELY YIELD AREAS OF RADIATION FOG TUE NIGHT.
OUTLOOK...
WED...AM FOG POSSIBLE. ISOLD PM TSRA IMPACTS POSSIBLE.
THU...NO SIG WX EXPECTED.
FRI...SHSN/VIS REDUCTIONS POSS W MTNS.
SAT...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...DANGELO/DEVOIR/LAMBERT
SHORT TERM...LAMBERT
LONG TERM...STEINBUGL
AVIATION...FITZGERALD/MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
133 AM EDT TUE MAR 15 2016
.SYNOPSIS...
UPPER TROUGH DISSOLVES AS IT CROSSES THE AREA OVERNIGHT AND
HEIGHTS SHOULD RISE ON TUESDAY. HOWEVER...CLOUDS WILL KEEP IT A
BIT COOL. A WEAK COLD FRONT WILL CROSS THE STATE WEDNESDAY.
COOLER AND UNSETTLED CONDITIONS WITH A FEW RAIN SHOWERS WILL OCCUR
THURSDAY. THE SCATTERED RAIN SHOWERS WILL MIX WITH WET SNOW
FRIDAY.
&&
.NEAR TERM /UNTIL 9 AM THIS MORNING/...
130AM EDT UPDATE...
THINGS HAVE TOTALLY FALLEN APART OVER WRN PA - AND NEVER REALLY
MADE IT INTO THE CWA. OUR STABILITY HAS SQUASHED THE CONVECTION.
HAVE THUS DROPPED POPS CONSIDERABLY. STILL GOING TOO BE LOTS OF
DZ/LOW CLOUDS AROUND. SO HELD ONTO DZ/FG MENTIONS IN THE WX GRIDS
FOR THE ENTIRE NIGHT AND INTO THE FIRST HALF OF THE AM. SMALL
CHANGES TO THE NEXT FEW PERIODS BUT NOTHING MUCH TO MENTION AT
THIS POINT.
PREV...
LITTLE CHANGE LATE THIS EVENING...AS LLVL EASTERLY FLOW OF COOL
MOIST AIR HAS LOW CLOUDS LOCKED IN ACROSS THE ENTIRE FORECAST AREA
WITH WIDESPREAD LOW STRATUS..WITH FOG BLANKETING THE RIDGE TOPS.
SHOWERS OVER SOUTHWEST PA ARE STILL FORECAST TO DAMPEN AS PER
LATEST HI RES HRRR AND WRF ARW RUNS...RUNNING INTO THE COOL STABLE
AIR OVER CENTRAL AND EASTERN PA OVERNIGHT. HOWEVER...GIVEN THE
FORCING ARRIVING OVERNIGHT ASSOCIATED WITH THE 5H UPPER TROF...DO
EXPECT HIGH CHC TO LIKELY POPS TO IMPACT THE WEST CENTRAL AND
LAUREL HIGHLANDS BEFORE TAPERING FARTHER EAST. OVER THE CENTRAL
AND EAST...SHOWERS WILL BE MORE SCARCE...BUT DRIZZLE WILL BE
PREVALENT THROUGH EARLY TUESDAY MORNING.
LOWS TONIGHT WILL BE IN THE MID 30S...TO NEAR 40F IN THE LOWER
SUSQ REGION.
&&
.SHORT TERM /9 AM THIS MORNING THROUGH 6 PM WEDNESDAY/...
CLOUDS WILL CONTINUE TO HANG TOUGH ON TUESDAY AS PWATS REMAIN
ABOVE NORMAL AND THERE WILL BE VERY LITTLE PUSH OF DRY AIR TO
DISLODGE THE MOISTURE. WE SHOULD SEE TEMPERATURES REBOUND ABOVE
TODAY/S CHILLY READINGS HOWEVER...MAKING IT BACK INTO THE 50S. THE
CLOUDS ACROSS THE NRN TIER COULD KEEP THEM MORE NEAR 50F...BUT
BREAKS IN THE CLOUDS IN THE S WILL MAKE THEM CLOSE TO 60F.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
CONSENSUS OF GUIDANCE SHOWS AN AMPLIFIED SHORTWAVE TROUGH/CLOSED
500MB LOW PIVOTING NORTHWARD OVER THE UPPER MIDWEST AND WESTERN
GREAT LAKES REGION ON DAY 3/WED. A REX BLOCK FORMS BRIEFLY WITH A
CLOSED UPPER HIGH OVER MANITOBA. AT THE SURFACE...AN OCCLUDED LOW
IS FCST TO DRIFT N ACROSS WI WITH AN OCCLUDED COLD FRONT ARCING
DOWNSTREAM AND PUSHING E ACROSS THE APPALACHIANS/MID- ATLANTIC
STATES. MODELS GENERALLY AGREE IN GENERATING SHOWERS ALONG/AHEAD
OF THE OCCLUDED FRONT WITH SOME ELEVATED THUNDER POTENTIAL.
THE INITIAL BLOCKING PATTERN OVER SRN CANADA AND THE NRN CONUS
WILL ULTIMATELY EVOLVE INTO A CNTRL-ERN U.S. MEAN TROUGH THAT
COULD SUPPORT A STRONGLY DEVELOPING SFC SYSTEM IN THE MID-ATLANTIC
AND NORTHEAST STATES THIS WEEKEND INTO MONDAY. THERE ARE STILL
IMPORTANT MODEL DIFFERENCES THAT REMAIN UNRESOLVED WITH INDIVIDUAL
ENSEMBLE MEMBERS VERY DISPERSED SUN-MON IN A LOW TRACK RANGING
FROM WELL INLAND TO OFFSHORE. THEREFORE THE DEGREE OF CERTAINTY
OR CONFIDENCE IN FORECAST DETAILS IS LOW/BELOW AVERAGE AT THIS
TIME.
SENSIBLE WEATHER HIGHLIGHTS WILL BE A SEASONABLE COOLING TREND BY
THE END OF THE PERIOD FROM THE MID-WEEK PEAK/ANOMALOUS WARMTH.
THERE IS A LARGE SPREAD IN THE SFC LOW TRACK LATE IN THE PERIOD
WHICH TEMPERS CONFIDENCE IN DETERMINING PRECIP EXTENT/TIMING AND
TYPE. A LATE SEASON SNOW EVENT IS A POSSIBLE OUTCOME BUT THE ODDS
ARE VERY LOW AT THIS POINT.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
A MOIST LLVL EASTERLY FLOW IS PRODUCING WIDESPREAD IFR CIGS ACROSS
CENTRAL PA AS OF 03Z...WITH LIFR NOTED ACROSS THE HIGH TERRAIN
AIRFIELDS /KBFD AND KJST/. ONLY KIPT REMAINS MVFR...BUT BULK OF
MDL GUIDANCE INDICATES A BIT OF RADIATIONAL COOLING LIKELY CAUSE
CIGS TO DIP BLW 1KFT THERE FOR A TIME EARLY TUE AM.
EARLIER LINE OF TSRA FELL APART BEFORE REACHING CENTRAL PA...AS
ASSOC MID LVL DISTURBANCE WEAKENED AND LINE ENCOUNTERED A MORE
STABLE AIR MASS ACROSS PA.
SOME MODEST IMPROVEMENT TO WIDESPREAD MVFR CIGS WILL LIKELY OCCUR
BY TUES AFTERNOON...AS MOIST EASTERLY FLOW WEAKENS.
PARTIAL CLEARING...LIGHT WIND AND WET GROUND ASSOC WITH ARRIVAL
OF SFC RIDGE WILL LIKELY YIELD AREAS OF RADIATION FOG TUE NIGHT.
OUTLOOK...
WED...AM FOG POSSIBLE. ISOLD PM TSRA IMPACTS POSSIBLE.
THU...NO SIG WX EXPECTED.
FRI...SHSN/VIS REDUCTIONS POSS W MTNS.
SAT...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...DANGELO/DEVOIR/LAMBERT
SHORT TERM...LAMBERT
LONG TERM...STEINBUGL
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
159 AM EDT TUE MAR 15 2016
.SYNOPSIS...
A WAVE OF LOW PRESSURE WILL TRACK EAST OF THE AREA OVERNIGHT WHICH
WILL BRING AN END TO ONGOING SHOWERS AND STORMS LATE. WEAK HIGH
PRESSURE SHOULD ARRIVE BY TUESDAY AND PROVIDE DRY AND UNSEASONABLY
WARM CONDITIONS FOR THE MIDDLE OF THIS WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 920 PM EDT MONDAY...
AXIS OF DEEPER CONVECTION NOW SWINGING EAST OF THE BLUE RIDGE
WHERE THE WEDGE CONTINUES TO LINGER IN PLACE. THUS EXPECT WILL SEE
MOST STORMS WEAKEN AND BECOME MORE ELEVATED UPON CROSSING DEEPER
INTO THE COOL POOL. HOWEVER STILL COULD SEE SOME SPOTTY HAIL SO
LEAVING IN THUNDER MENTION UNTIL AROUND MIDNIGHT ACROSS AREAS
ROUGHLY FROM LYH TO DAN AND POINTS EAST. LATEST HRRR THEN SHOWS
THIS BAND OF LIFT HEADING EAST/NE OF THE CWA AFTER MIDNIGHT WITH
SUBSIDENCE SPILLING IN UNDER THE MAIN SHORTWAVE THAT WILL PASS
OVERHEAD SHORTLY AND TO THE EAST OVERNIGHT. THIS SHOULD ALSO ALLOW
FOR A DECREASE IN SHOWERS OVER THE WEST BUT ENOUGH WEAK UPSLOPE
AND WRAP AROUND TRAJECTORY TO KEEP SOME CHANCE POPS GOING INTO THE
EARLY MORNING HOURS. WILL MAKE SOME SLIGHT ADJUSTS TO TEMPS TO
NUDGE DOWN WHERE ALREADY AT FORECAST LOWS BUT GIVEN SATURATION NOT
EXPECTING VALUES TO FALL MUCH OVERNIGHT.
PREVIOUS DISCUSSION AS OF 345 PM EDT MONDAY...
THE SITUATION IS CURRENTLY UNFOLDING AS ADVERTISED WITH THE
LINGERING WEDGE HOLDING ON IN THE PIEDMONT WITH THUNDERSTORMS
DEVELOPING IN THE MORE UNSTABLE AIR TO THE SOUTH AND WEST. THE
CONVECTION IS BEING DRIVEN BY AN ACTIVE UPPER LEVEL SHORT WAVE
WHICH WILL HELP STEEPEN LAPSE RATES THROUGH THE EVENING. CURRENTLY
BELIEVE THE CONVECTION WILL MOVE ACROSS THE REGION AND CLEAR THE
EASTERN ZONES AROUND MIDNIGHT. THUNDER CHANCES WILL BE LEAST WHERE
THE WEDGE IS HOLDING ON BUT OTHER LOCATIONS WHERE CONVECTION DOES
FIRE WILL BE DEALING HAIL PRODUCING STORMS WITH A SLIGHT THREAT
FOR LARGE HAIL AND GUSTY WINDS.
LATER TONIGHT BEHIND THE SHORT WAVE EXPECT SOME LINGERING SHOWERS
WEST OF THE BLUE RIDGE THAT WILL GRADUALLY TAPER OFF AROUND
DAYBREAK TUESDAY. NO CHANGE OF AIRMASS SO LOWS TONIGHT WILL REMAIN
SOMEWHAT MILD IN THE UPPER 40S TO LOWER 50S...WITH HIGHS ON
TUESDAY GENERALLY UPPER 60S/NEAR 70 WEST OF THE RIDGE TO MIDDLE
70S EAST.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/...
AS OF 345 PM EDT MONDAY...
SHORTWAVE RIDGING TO TAKE PLACE TUESDAY NIGHT AHEAD OF A DEEPENING
NEGATIVE TILT TROUGH OVER THE NORTHERN PLAINS INTO THE LOWER GREAT
LAKES. A WARM FRONT IS EXPECTED TO LIFT NORTHEAST THROUGH THE
CENTRAL APPALACHIANS LATE TUESDAY NIGHT WITH SOME LIGHT SHOWERS
POSSIBLE ACROSS THE MOUNTAINS. LOWS WILL BE MILD IN THE UPPER 40S TO
MID 50S.
WEDNESDAY....AN WESTERLY FLOW AT LOW AND MID LEVELS WITH INCREASING
SUNSHINE WILL ALLOW FOR TEMPS TO GET WELL INTO THE 70S MAINLY EAST
OF THE BLUE RIDGE...WITH SOME IN SOUTHSIDE VA INTO THE NC PIEDMONT
REACHING 80. THE MOUNTAINS WILL STAY WARM AS WELL WITH UPPER 60S TO
LOWER 70S. COULD SEE A FEW SHOWERS WED MORNING.
WEDNESDAY NIGHT FRONTAL SYSTEM MOVES ACROSS WITH 5H HEIGHTS FALLING
AS UPPER LOW MOVES ACROSS THE GREAT LAKES. MOISTURE IS LIMITED WITH
THIS SYSTEM...SO NOT LOOKING AT ANY THREAT OF RAIN...MAY BE SOME
LIGHT SHOWERS ACROSS THE SOUTHERN AND CENTRAL APPALACHIANS. TEMPS
WILL BE SLIGHTLY COOLER BUT ABOVE NORMAL IN THE 40S.
THURSDAY...A SFC WAVE STARTS TO FORM ALONG THE FRONT ACROSS THE GULF
COAST STATES AND SOUTHEAST. THIS MAY ACT TO BRING SOME MOISTURE OUR
WAY WITH THE FRONT NEARBY BUT STILL NOT EXPECTING ANY DECENT
CHANCES...SO HAVE POPS LOW CHANCE WV TO SLIGHT CHANCE ELSEWHERE.
TEMPS WILL BE ABOUT 10 DEGREES COOLER THAN WEDNESDAY BUT STILL WARM
FOR MID MARCH WITH UPPER 50S TO MID 60S WEST...TO AROUND 70
SOUTHEAST.
THINGS WILL BE CLEARING OUT THURSDAY NIGHT AS 5H HEIGHTS CONTINUE
FALLING...WITH MAIN TROUGH AXIS FROM THE GREAT LAKES TO THE CENTRAL
APPALACHIANS AND TN VALLEY. LOWS WILL RANGE FROM THE MID TO UPPER
30S WEST...TO LOWER TO MID 40S EAST.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 345 PM EST MONDAY...
FORECAST THIS PERIOD REMAINS SOMEWHAT SKETCHY BUT ALL MODELS
INDICATE BACK TO NORMAL OR JUST BELOW NORMAL TEMPERATURES.
FRIDAY WILL BE DRY...THOUGH SOME SHORTWAVE ENERGY SHOULD BRING
INCREASING MID AND HIGH CLOUDS TO THE AREA. FRIDAY WILL STILL BE
MILD BEFORE THE TROUGH SLIPS SOUTHEAST OVER THE WEEKEND...WITH HIGHS
IN THE 50S WEST TO LOWER TO MID 60S EAST.
FRONTAL BOUNDARY WILL BE STALLED NEAR THE GULF COAST FRIDAY....INTO
SATURDAY. COLD HIGH PRESSURE WILL SLIDE ACROSS THE GREAT LAKES INTO
THE NORTHEAST. AS THE UPPER LOW MOVES ACROSS THE OHIO VALLEY
SATURDAY NIGH INTO SUNDAY...THE FRONTAL BOUNDARY WILL SLIDE NORTH
ACROSS US WITH LOW PRESSURE FORMING ACROSS THE EASTERN PORTIONS OF
THE CAROLINAS...WITH SECOND LOW OVER THE UPPER OHIO VALLEY.
CURRENTLY....CRITICAL THICKNESSES AND TEMPS WILL KEEP PRECIP MAINLY
RAIN...BUT AS COLDER MOVES ACROSS BEHIND THE LOW SOME SNOW MAY OCCUR
OVER THE HIGHER TERRAIN SUNDAY NIGHT INTO MONDAY MORNING...BUT BY
THEN THE DEEPER MOISTURE WILL BE EXITING. STILL BEARS WATCH AS
COLDER AIR AND UPPER LOW MAY BE CLOSE ENOUGH TO BRING SOME HIGH
ELEVATIONS SNOWS TO THE CENTRAL AND SOUTHERN APPALACHIANS.
THE WEEKEND INTO MONDAY WILL BE COOL...WITH LOWS MAINLY IN THE
30S...AND HIGHS RANGING FROM THE 40S WEST TO LOWER TO MID 50S EAST.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 145 AM EDT TUESDAY...
LAST SHOWERS ASSOCIATED WITH STRONG UPPER SHORT WAVE MOVING
THROUGH THE EASTERN COUNTIES OF THE CWA. RAIN SHOULD BE ENDING AT
KLYH DURING THE HOUR...AND HAS ALREADY ENDED AT KDAN. LINGERING
SPOTTY SHOWERS ASSOCIATED WITH SURFACE FRONT ACROSS SOUTHEAST
WV...MOST OF WHICH WILL REMAIN WEST OF THE BLUE RIDGE AND WEST OF
I-81. UNFORTUNATELY...AS IS OFTEN THE CASE WITH THIS TYPE OF
SYNOPTIC SCENARIO...TRUE SURFACE DRYING WILL NOT TAKE PLACE UNTIL
AFTER DAYBREAK WHEN MIXING CAN COMMENCE. THUS...EXPECT LOW CLOUDS
AND FOG TO LINGER EAST OF THE BLUE RIDGE...WITH UPSLOPE CLOUDS
LINGERING TO THE WEST OF THE BLUE RIDGE THROUGH DAYBREAK OR AN
HOUR OR TWO THEREAFTER. THUS...IFR-LIFR CIGS STILL APPEAR TO BE A
GOOD PROBABILITY FOR MOST TAF SITES FOR THESE REASONS THROUGH
13Z...WITH KROA LIKELY SEEING MVFR-IFR THROUGH MUCH OF THE NIGHT
AS WELL. AFT 14Z...EXPECT FAIRLY QUICK IMPROVEMENT TO VFR AND
EVENTUALLY SKC EAST OF THE BLUE RIDGE TO IMPACT KLYH...KDAN...AND
KROA...WITH LINGERING MVFR CIGS TO THE WEST...INCLUDING
KBCB...KLWB...AND KBLF. CLOUDS AND MVFR CIGS WILL LINGER THE
LONGEST FOR KBLF AND KLWB INTO MIDDAY/EARLY AFTERNOON.
VISIBILITIES SHOULD IMPROVE TO VFR AT ALL SITES BY 14Z.
WINDS HAVE ALREADY BECOME WEST 6-8KTS WEST OF THE ALLEGHANY
FRONT...BUT WILL LIKELY TAKE UNTIL DAYBREAK TO REACH AREAS TO THE
EAST. AFTER 13Z...EXPECT WINDS TO BE W-WNW 8-12KTS WITH GUSTS
18-20KTS THROUGH LATE AFTERNOON...THEN BECOME VARIABLE IN RESPONSE
TO THE NEXT UPSTREAM SYSTEM. THIS NEXT UPSTREAM SHORT WAVE WILL
BEGIN TO SPREAD MID/HIGH CLOUDS INTO THE WESTERN PART OF THE CWA
AFT 00Z...BUT VFR CIGS ARE EXPECTED AT ALL TAF SITES FROM LATE
AFTERNOON THROUGH THE REMAINDER OF THE TAF VALID PERIOD.
EXTENDED DISCUSSION...
A FAST MOVING NEGATIVELY TILTED UPPER TROUGH WILL BRING SOME MID
CLOUDS AND PERHAPS A FEW SHOWERS MAINLY TO AREAS WEST OF I-81 AND
NORTH OF U.S. 460 WEDNESDAY. BEHIND THIS SYSTEM...GUSTY WEST WINDS
LOOK TO BE A GOOD BET AND A WIND ADVISORY MAY NEED TO BE
CONSIDERED FOR THIS PERIOD AS A DEEP SURFACE LOW MOVES EASTWARD
THROUGH THE GREAT LAKES. ANOTHER SHORT WAVE WILL MOVE THROUGH
THURSDAY AND HERALD A RETURN TO GRADUALLY COOLER CONDITIONS THAT
WILL PERSIST INTO THE WEEKEND AS A BROAD UPPER LOW GRADUALLY SINKS
SOUTHWARD THROUGH THE EASTERN 2/3RD OF THE U.S. WITH LOWERING
HEIGHTS. FOR THE MOST PART...PERIODS OF MVFR CLOUDS WILL BE
INCREASINGLY LIKELY FOR WESTERN AREAS WITH MOSTLY VFR CONDITIONS
EAST OF THE BLUE RIDGE. SHOWERS MAY ALSO BE POSSIBLE FROM TIME-
TO-TIME...ESPECIALLY WEST OF THE BLUE RIDGE.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...MBS
NEAR TERM...JH/MBS
SHORT TERM...WP
LONG TERM...PM/RAB/WP
AVIATION...JH/RAB
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
953 AM CDT TUE MAR 15 2016
.UPDATE...
ISSUED AT 953 AM CDT TUE MAR 15 2016
Latest models continue to delay the onset of strong to severe
convection later today. 12z NAM tracks 998mb low currently south
of Kansas City into southeast Iowa by 00z. Forecast soundings show
the airmass ahead of the system will remain strongly capped
through the afternoon, suppressing any storm development within
the warm sector. As a short-wave trough evident on 14z/9am water
vapor imagery over eastern Colorado approaches from the west, the
cap will gradually erode toward evening. At that time, scattered
thunderstorms will develop along an advancing cold front. While
the NAM shows little or no convection along the front, higher-res
models such as the HRRR show scattered storms forming across
northern Missouri by late afternoon, then tracking northeastward
across the northern half of the KILX CWA this evening. Damaging
winds and large hail remain the primary threats...although a few
tornadoes will be possible near the low track primarily northwest
of the I-55 corridor. Have updated the forecast this morning to
remove PoPs everywhere except the far north where a small cluster
of storms has been moving across Knox, northern Peoria, and Stark
counties. Have also gone largely dry through the afternoon, with
low chance PoPs arriving after 22z along/west of the Illinois
River. Also reduced sky cover to go with a partly to mostly sunny
forecast with afternoon highs in the lower to middle 70s.
&&
.SHORT TERM...(Today)
ISSUED AT 345 AM CDT TUE MAR 15 2016
A 997 mb surface low over south central KS early this morning
will deepen as a shortwave over the central Rockies tracks
eastward into the Plains. The low looks to move into west central
IL by evening...although some track differences are noted in model
guidance by this time. A warm front will likely extend from
southeast Iowa into Central Illinois...roughly along the I-74
corridor. Sfc-6 km bulk shear should easily exceed 50 kts while
models suggest 1500-2500 J/KG MUCAPE develops across central IL.
Especially in the vicinity of the warm front and toward the
surface low pressure...this could bring a threat for rotating
storms and a slight tornado threat in the late afternoon and
evening. In addition...steep mid-level lapse rates will bring a
threat of large hail and damaging winds. Models have slowed down
somewhat in sweeping a cold front across central IL mainly 00z to
06z this evening now...bringing this best chance for a coherent
line of thunderstorms. SPC has central Illinois from around I-70
northward outlooked for a slight risk of severe thunderstorms as a
result. A slight chance of thunderstorms will move into areas west
of the Illinois River by daybreak as a cluster of storms currently
over NW Missouri/SW Iowa moves eastward. This disturbance will
continue northeastward into northern Illinois by
afternoon...bringing slight chances for thunderstorms about as far
southward by noon. A bit of a lull toward afternoon as the cold
frontal band approaches again for the late afternoon...spreading a
chance for thunderstorms throughout much of central Illinois north
of I-70 by evening.
Also in the short term...an area of dense fog has formed in clear
skies and light winds from near Paris to just east of Peoria...and
have issued a dense fog advisory until 9 a.m. To the west...high
cloud cover and strengthening southeast winds have limited
development of fog...and to the northeast a bank of stratus has
limited radiational cooling needed to produce dense fog.
Warm highs today should reach the low to mid 70s as warm moist
air advects in from the south ahead of the approaching low center.
Winds in the morning expected to be around 5-15 mph from the
southeast...increasing to 15-20 mph by afternoon with gusts to the
25-30 mph range.
.LONG TERM...(Tonight through Monday)
ISSUED AT 345 AM CDT TUE MAR 15 2016
00Z forecast models continue slower trend with deepening surface low
pressure ejecting ne from eastern KS into west central IL by 00Z/7
pm today and into WI by 12Z/7 am Wed and deepening to 985 mb or
stronger by then. A warm front to be near I-74 late this afternoon
and evening, while a sharp cold front accelerates eastward across IL
this during this evening with scattered to broken line of convection
expected ahead of front. SPC day1 outlook has shifted slight risk of
severe storms nw of I-70 where 15% risk of damaging wind gusts and
large hail and 2-5% risk of tornadoes, with the 5% risk from I-55
nw. Convection to develop over ne MO/se IA and west central IL late
this afternoon and track eastward across central and eastern IL
during the evening. Most of this convection should be east of
central IL overnight with isolated showers along and north of a
Rushville to Bloomington line after midnight. Models have increased
wind speeds overnight and Wed and northern areas may be reaching
wind advisory criteria with sustained winds 30 mph and wind gusts 40-
45 mph. A High wind watch has been posted over northern IL overnight
and Wed where even higher winds expected.
Strong cutoff 500 mb low deepening to 525-530 dm as it lifts ne
across WI and into upper MI during Wed along with associated strong
surface low pressure near this upper level low to give the strong
WSW winds over IL overnight and Wed. Shower chances to stay north of
central IL Wed and Thu closer to strong low pressure system hanging
around the western Great Lakes region. Mostly sunny skies
expectedWed. Temperatures about 10 degrees cooler on Wed than today,
but still a good 10 degrees above normal for mid March. Highs Wed
mostly in the lower 60s, ranging from near 60F nw of IL river to mid
60s se of I-70. Lows Wed night in the upper 30s north of I-72 and
lower 40s south of I-72. A weak short elongated short wave to track
east across the mid MS river valley Wed night and bring slight
chances of light rain showers to areas se of I-70 in southeast IL.
Still windy on Thu with west winds 20-25 mph and gusts of 25-35 mph
with partly to mostly sunny skies, more clouds from I-74 north.
Temps cool a bit more on Thu with highs ranging from lower 50s from
Peoria and Bloomington north to near 60F south of I-70.
Strong upper level low shifts east across the Great Lakes Thu night
while weak upper level ridge into IL on Friday keeps it dry with
lighter WNW winds diminishing to 8-15 mph. Highs Friday upper 40s
northern CWA and lower 50s southern half of CWA which is starting
to get a bit below normal for our area.
Extended forecast models continue to dig a deep upper level trof se
across the Midwest Fri night and Saturday and into the OH/TN river
valleys on Sunday. Stronger surface low pressure and heavier qpf in
over the southeast states, with lighter qpf over IL Fri night into
Sat evening. Some light qpf could still linger over eastern IL
Sunday. Temperature profiles support a chance of light snow with
ligth rain overnight Friday night and Sat morning and again Sat
night and Sunday morning if it lingers that long. Temps to be a bit
cooler than normal this weekend with highs in the mid to upper 40s
Sat/Sun and lows near freezing Sat and Sun nights.
Upper level trof shifts away from IL on Sunday night and Monday
while upper level ridge to shift east across the plains toward the
MS river valley by next Tuesday and brings dry weather with temps
starting to moderate into the lower 50s Monday and 55-60F next Tue.
&&
.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
ISSUED AT 650 AM CDT TUE MAR 15 2016
Dense morning fog quickly dissipating this morning...with another
hour or so of LIFR vsby possible at KCMI and a few hours of
occasional MVFR vsby elsewhere. Morning thunderstorms headed
toward areas just north of KPIA-KBMI this morning and have
included a few hours of VCTS...however likelihood of arriving at
these terminals still low at this time. After this...VFR
conditions expected much of the day as capped thermodynamic
profiles likely to prevent thunderstorm development until late
afternoon or early evening as a cold front sweeps through the
area. Have included VCTS and MVFR cigs in late afternoon/evening
for most likely time period for thunderstorms. Winds SE 15-18 kts
with gusts to around 25 kts today...becoming SW overnight after
passage of a cold front.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...Barnes
SHORT TERM...Onton
LONG TERM...07
AVIATION...Onton
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1016 AM EDT TUE MAR 15 2016
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 326 AM EDT TUE MAR 15 2016
A COLD FRONT WILL BRING CHANCES FOR THUNDERSTORMS LATE THIS
AFTERNOON AND TONIGHT...AND SOME COULD BE SEVERE. LATER IN THE WEEK
AND INTO THE WEEKEND...AN UPPER LEVEL SYSTEM WILL BRING CHANCES FOR
SHOWERS. WARM TEMPERATURES TODAY WILL COOL TO BELOW AVERAGE BY THE
WEEKEND.
&&
.NEAR TERM /THIS AFTERNOON/...
ISSUED AT 953 AM EDT TUE MAR 15 2016
SURFACE ANALYSIS LATE THIS MORNING SHOWS SURFACE LOW PRESSURE
ENTERING SW MISSOURI. A WARM FRONT EXTENDED SOUTHEAST FROM THE LOW
ACROSS SRN MISSOURI AND ILLINOIS TO SRN INDIANA. VISIBLE
SATELLITE SHOWS A BAND OF HIGH CLOUD ACROSS NRN AND EAST CENTRAL
INDIANA...LIFTING NORTHWARD. RADAR WAS QUIET. WATER VAPOR SHOWS
THE NEXT SHORT WAVE FOR TONIGHT PUSHING INTO THE DAKOTAS. LOW
LEVEL FLOW WAS FROM THE SOUTHEAST AS DEW POINTS WERE IN THE 60S.
GFS AND NAM SUGGEST WARM AIR ADVECTION THIS AFTERNOON AS THE WARM
FRONT LIFTS NORTH ACROSS THE AREA. FORECAST SOUNDINGS AND TIME
HEIGHTS REMAIN MOSTLY DRY THROUGH THE AFTERNOON WITH CONVECTIVE
TEMPS IN THE UPPER 60S AND LOWER 70S. THUS WILL TREND TOWARD A
MOSTLY CLEAR SKY THIS MORNING...BUT INCREASE CLOUDS THIS AFTERNOON
AS CU DEVELOPMENT WILL BE EXPECTED. BEST FORCING STILL LOOKS
TO ARRIVE AFT 00Z...THUS WILL CONTINUE WITH MAINLY A DRY FORECAST.
&&
.SHORT TERM.../TONIGHT THROUGH THURSDAY NIGHT/
ISSUED AT 326 AM EDT TUE MAR 15 2016
FOCUS IS ON RAIN CHANCES THROUGH THE PERIOD AND SEVERE WEATHER
TONIGHT. GENERALLY STUCK WITH A MODEL BLEND...BUT GFS SEEMS TOO
AGGRESSIVE WITH UPPER LOW MOVING SOUTH LATE. TRENDED AWAY FROM GFS
THEN.
FRONT WILL MOVE THROUGH THE AREA MID EVENING INTO THE OVERNIGHT.
STILL GOOD SHEAR ACROSS THE AREA...BUT INSTABILITY IS MORE IN
QUESTION GIVEN THE TIME OF DAY. AGREE WITH STORM PREDICTION CENTER
FORECAST OF MOVING THE SLIGHT RISK NORTH AND WEST.
STRONG FORCING WITH UPPER TROUGH AND AN UPPER JET SHOULD LEAD TO
LIKELY POPS ACROSS THE NORTH THIRD OR SO OF THE AREA TONIGHT. MODEL
REFLECTIVITY FORECASTS SHOW MORE OF A BROKEN LINE OF CONVECTION
SOUTH 2/3 OF THE AREA...SO WENT CHANCE POPS THERE.
ALL RAIN SHOULD BE OUT OF THE AREA BY 12Z WEDNESDAY...AND UPPER
TROUGH WILL REMAIN WELL TO THE NORTH. WENT WITH A DRY FORECAST. A
WEAK UPPER IMPULSE WILL MOVE THROUGH THE AREA WEDNESDAY NIGHT...SO
KEPT SLIGHT CHANCE POPS MOST AREAS FOR THAT TIME FRAME.
WENT WITH A DRY FORECAST THURSDAY AND THURSDAY NIGHT WITH THE UPPER
TROUGH STAYING TO THE NORTH.
OTHER ITEM OF CONCERN IS WINDS BEHIND THE FRONT WEDNESDAY. STRONG
WINDS ALOFT LOOK TO MIX DOWN SOME WITH SUNSHINE EXPECTED. WIND GUSTS
AROUND 40 MPH /AND POTENTIALLY HIGHER PER SOME MODEL BUFKIT
SOUNDINGS/ ARE POSSIBLE. WILL KEEP AN EYE ON IT AND MENTION IT IN
THE HAZARDOUS WEATHER OUTLOOK FOR NOW.
GENERALLY STUCK WITH A MODEL BLEND FOR TEMPERATURES THROUGH THE
PERIOD.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
ISSUED AT 224 AM EDT TUE MAR 15 2016
COOLER TEMPERATURES AND SHOWER CHANCES ARE IN STORE THROUGH THE
WEEKEND WITH DRY WEATHER LIKELY TO START NEXT WEEK.
00Z OPERATIONAL MODELS ARE IN GOOD AGREEMENT THAT A FRONT WILL BE
NEARBY ON FRIDAY...AND THERE WILL BE ENOUGH MOISTURE TO SQUEEZE OUT
A FEW LIGHT SHOWERS OR SPRINKLES FRIDAY. THEN...THINGS CHANGE AS THE
GFS IS MUCH QUICKER TO BRING AN UPPER SYSTEM OVER THE AREA THEN THE
ECMWF. DESPITE THIS...BOTH MODELS HAVE QPF OVER CENTRAL THROUGH
SUNDAY AS DOES THE REGIONAL BLEND. WITH THAT IN MIND...WILL KEEP
SHOWER CHANCES GOING. FRIDAY NIGHT THROUGH SUNDAY WITH THE BEST
CHANCES SATURDAY AND SATURDAY NIGHT. LOW LEVEL THICKNESSES SUPPORT A
MIX AND OR CHANGEOVER TO SNOW OVERNIGHT FRIDAY NIGHT AND EARLY
SATURDAY AND OVERNIGHT SATURDAY NIGHT AND EARLY SUNDAY. THE GROUND
WILL BE TOO WARM FOR EVEN A MINOR SNOW ACCUMULATION...HOWEVER. AFTER
THAT...SURFACE HIGH PRESSURE WILL BUILD OVER THE AREA ON MONDAY AND
RESULT IN DRY WEATHER.
WITH MODEL DIFFERENCES...WILL NOT STRAY FAR FROM THE REGIONAL BLEND
WITH BELOW NORMAL TEMPERATURES BY SATURDAY.
&&
.AVIATION /DISCUSSION FOR THE 151500Z TAF ISSUANCE/...
ISSUED AT 1016 AM EDT TUE MAR 15 2016
FOG REALLY BEGINNING TO DIMINISH NOW AND LOWER STRATUS HAS LARGELY
BROKEN UP AS WELL...LEAVING MOSTLY SUNNY SKIES ACROSS THE REGION.
MADE MINOR ADJUSTMENTS TO TERMINALS BASED ON CURRENT OBS. EXPECT
SOUTHEAST WINDS TO BECOME BREEZY AS THE AFTERNOON PROGRESSES ALONG
WITH CU FORMATION.
12Z DISCUSSION FOLLOWS.
THE FOG SHOULD DISSIPATE BY 15Z AT BMG AND HUF PER LAMP MOS AS
SURFACE PRESSURE GRADIENT STARTS TO TIGHTEN AHEAD OF AN APPROACHING
MISSOURI VALLEY LOW PRESSURE SYSTEM. MEANWHILE...THICK STRATUS
DECK...NEAR AND NORTH OF IND-LAF QUASI-STATIONARY FRONT...WILL
GRADUALLY LIFT TO NEAR 3K FEET BY THIS AFTERNOON WITH DIURNAL CU
DEVELOPING SOUTH OF THAT LINE WITH MVFR CEILINGS APPROACHING 3K
FEET. ANY IFR CONDITIONS SHOULD IMPROVE AT IND AND LAF BY 13Z.
CONFIDENCE IN EXACT TIMING IS NOT GREAT BUT CONFIDENCE IN TRENDS IS
GOOD. COULD ALSO SEE CEILINGS IMPROVE TO VFR AROUND 21Z FOR A FEW
HOURS BEFORE CONVECTION MOVES IN. MODELS INCLUDING THE HRRR SUGGEST
ANY STORMS WILL HOLD OFF UNTIL AFTER 00Z WEDNESDAY AT HUF AND LAF
AND LATER STILL AT IND AND BMG. WILL BRING IN A PROB30 MVFR THUNDER
GROUP 01Z-07Z. WILL ALSO GO WITH CONVECTIVE GUSTS AS HIGH AS 40
KNOTS. THE CLOUDS WILL BE DECREASING BEHIND THE COLD FRONT THAT
SHOULD MOVE THROUGH 05Z-09Z.
WINDS WILL GRADUALLY PICK UP FROM THE SOUTHEAST AFTER 13Z. WINDS
WILL INCREASE TO AROUND 10 KNOTS OR SO WITH GUSTS TO NEAR 20 KNOTS
AFTER 18Z. WINDS WILL SHIFT TO THE SOUTHWEST AND WEST BEHIND THE
COLD FRONT AND INCREASE TO AROUND 15 KNOTS WITH GUSTS TO NEAR 25
KNOTS OVERNIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...50
NEAR TERM...PUMA
SHORT TERM...50
LONG TERM...MK
AVIATION...MK/RYAN
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
953 AM EDT TUE MAR 15 2016
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 326 AM EDT TUE MAR 15 2016
A COLD FRONT WILL BRING CHANCES FOR THUNDERSTORMS LATE THIS
AFTERNOON AND TONIGHT...AND SOME COULD BE SEVERE. LATER IN THE WEEK
AND INTO THE WEEKEND...AN UPPER LEVEL SYSTEM WILL BRING CHANCES FOR
SHOWERS. WARM TEMPERATURES TODAY WILL COOL TO BELOW AVERAGE BY THE
WEEKEND.
&&
.NEAR TERM /THIS AFTERNOON/...
ISSUED AT 953 AM EDT TUE MAR 15 2016
SURFACE ANALYSIS LATE THIS MORNING SHOWS SURFACE LOW PRESSURE
ENTERING SW MISSOURI. A WARM FRONT EXTENDED SOUTHEAST FROM THE LOW
ACROSS SRN MISSOURI AND ILLINOIS TO SRN INDIANA. VISIBLE
SATELLITE SHOWS A BAND OF HIGH CLOUD ACROSS NRN AND EAST CENTRAL
INDIANA...LIFTING NORTHWARD. RADAR WAS QUIET. WATER VAPOR SHOWS
THE NEXT SHORT WAVE FOR TONIGHT PUSHING INTO THE DAKOTAS. LOW
LEVEL FLOW WAS FROM THE SOUTHEAST AS DEW POINTS WERE IN THE 60S.
GFS AND NAM SUGGEST WARM AIR ADVECTION THIS AFTERNOON AS THE WARM
FRONT LIFTS NORTH ACROSS THE AREA. FORECAST SOUNDINGS AND TIME
HEIGHTS REMAIN MOSTLY DRY THROUGH THE AFTERNOON WITH CONVECTIVE
TEMPS IN THE UPPER 60S AND LOWER 70S. THUS WILL TREND TOWARD A
MOSTLY CLEAR SKY THIS MORNING...BUT INCREASE CLOUDS THIS AFTERNOON
AS CU DEVELOPMENT WILL BE EXPECTED. BEST FORCING STILL LOOKS
TO ARRIVE AFT 00Z...THUS WILL CONTINUE WITH MAINLY A DRY FORECAST.
&&
.SHORT TERM.../TONIGHT THROUGH THURSDAY NIGHT/
ISSUED AT 326 AM EDT TUE MAR 15 2016
FOCUS IS ON RAIN CHANCES THROUGH THE PERIOD AND SEVERE WEATHER
TONIGHT. GENERALLY STUCK WITH A MODEL BLEND...BUT GFS SEEMS TOO
AGGRESSIVE WITH UPPER LOW MOVING SOUTH LATE. TRENDED AWAY FROM GFS
THEN.
FRONT WILL MOVE THROUGH THE AREA MID EVENING INTO THE OVERNIGHT.
STILL GOOD SHEAR ACROSS THE AREA...BUT INSTABILITY IS MORE IN
QUESTION GIVEN THE TIME OF DAY. AGREE WITH STORM PREDICTION CENTER
FORECAST OF MOVING THE SLIGHT RISK NORTH AND WEST.
STRONG FORCING WITH UPPER TROUGH AND AN UPPER JET SHOULD LEAD TO
LIKELY POPS ACROSS THE NORTH THIRD OR SO OF THE AREA TONIGHT. MODEL
REFLECTIVITY FORECASTS SHOW MORE OF A BROKEN LINE OF CONVECTION
SOUTH 2/3 OF THE AREA...SO WENT CHANCE POPS THERE.
ALL RAIN SHOULD BE OUT OF THE AREA BY 12Z WEDNESDAY...AND UPPER
TROUGH WILL REMAIN WELL TO THE NORTH. WENT WITH A DRY FORECAST. A
WEAK UPPER IMPULSE WILL MOVE THROUGH THE AREA WEDNESDAY NIGHT...SO
KEPT SLIGHT CHANCE POPS MOST AREAS FOR THAT TIME FRAME.
WENT WITH A DRY FORECAST THURSDAY AND THURSDAY NIGHT WITH THE UPPER
TROUGH STAYING TO THE NORTH.
OTHER ITEM OF CONCERN IS WINDS BEHIND THE FRONT WEDNESDAY. STRONG
WINDS ALOFT LOOK TO MIX DOWN SOME WITH SUNSHINE EXPECTED. WIND GUSTS
AROUND 40 MPH /AND POTENTIALLY HIGHER PER SOME MODEL BUFKIT
SOUNDINGS/ ARE POSSIBLE. WILL KEEP AN EYE ON IT AND MENTION IT IN
THE HAZARDOUS WEATHER OUTLOOK FOR NOW.
GENERALLY STUCK WITH A MODEL BLEND FOR TEMPERATURES THROUGH THE
PERIOD.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
ISSUED AT 224 AM EDT TUE MAR 15 2016
COOLER TEMPERATURES AND SHOWER CHANCES ARE IN STORE THROUGH THE
WEEKEND WITH DRY WEATHER LIKELY TO START NEXT WEEK.
00Z OPERATIONAL MODELS ARE IN GOOD AGREEMENT THAT A FRONT WILL BE
NEARBY ON FRIDAY...AND THERE WILL BE ENOUGH MOISTURE TO SQUEEZE OUT
A FEW LIGHT SHOWERS OR SPRINKLES FRIDAY. THEN...THINGS CHANGE AS THE
GFS IS MUCH QUICKER TO BRING AN UPPER SYSTEM OVER THE AREA THEN THE
ECMWF. DESPITE THIS...BOTH MODELS HAVE QPF OVER CENTRAL THROUGH
SUNDAY AS DOES THE REGIONAL BLEND. WITH THAT IN MIND...WILL KEEP
SHOWER CHANCES GOING. FRIDAY NIGHT THROUGH SUNDAY WITH THE BEST
CHANCES SATURDAY AND SATURDAY NIGHT. LOW LEVEL THICKNESSES SUPPORT A
MIX AND OR CHANGEOVER TO SNOW OVERNIGHT FRIDAY NIGHT AND EARLY
SATURDAY AND OVERNIGHT SATURDAY NIGHT AND EARLY SUNDAY. THE GROUND
WILL BE TOO WARM FOR EVEN A MINOR SNOW ACCUMULATION...HOWEVER. AFTER
THAT...SURFACE HIGH PRESSURE WILL BUILD OVER THE AREA ON MONDAY AND
RESULT IN DRY WEATHER.
WITH MODEL DIFFERENCES...WILL NOT STRAY FAR FROM THE REGIONAL BLEND
WITH BELOW NORMAL TEMPERATURES BY SATURDAY.
&&
.AVIATION /DISCUSSION FOR THE 15/12Z TAF ISSUANCE/...
ISSUED AT 622 AM EDT TUE MAR 15 2016
THE FOG SHOULD DISSIPATE BY 15Z AT BMG AND HUF PER LAMP MOS AS
SURFACE PRESSURE GRADIENT STARTS TO TIGHTEN AHEAD OF AN APPROACHING
MISSOURI VALLEY LOW PRESSURE SYSTEM. MEANWHILE...THICK STRATUS
DECK...NEAR AND NORTH OF IND-LAF QUASI-STATIONARY FRONT...WILL
GRADUALLY LIFT TO NEAR 3K FEET BY THIS AFTERNOON WITH DIURNAL CU
DEVELOPING SOUTH OF THAT LINE WITH MVFR CEILINGS APPROACHING 3K
FEET. ANY IFR CONDITIONS SHOULD IMPROVE AT IND AND LAF BY 13Z.
CONFIDENCE IN EXACT TIMING IS NOT GREAT BUT CONFIDENCE IN TRENDS IS
GOOD. COULD ALSO SEE CEILINGS IMPROVE TO VFR AROUND 21Z FOR A FEW
HOURS BEFORE CONVECTION MOVES IN. MODELS INCLUDING THE HRRR SUGGEST
ANY STORMS WILL HOLD OFF UNTIL AFTER 00Z WEDNESDAY AT HUF AND LAF
AND LATER STILL AT IND AND BMG. WILL BRING IN A PROB30 MVFR THUNDER
GROUP 01Z-07Z. WILL ALSO GO WITH CONVECTIVE GUSTS AS HIGH AS 40
KNOTS. THE CLOUDS WILL BE DECREASING BEHIND THE COLD FRONT THAT
SHOULD MOVE THROUGH 05Z-09Z.
WINDS WILL GRADUALLY PICK UP FROM THE SOUTHEAST AFTER 13Z. WINDS
WILL INCREASE TO AROUND 10 KNOTS OR SO WITH GUSTS TO NEAR 20 KNOTS
AFTER 18Z. WINDS WILL SHIFT TO THE SOUTHWEST AND WEST BEHIND THE
COLD FRONT AND INCREASE TO AROUND 15 KNOTS WITH GUSTS TO NEAR 25
KNOTS OVERNIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...50
NEAR TERM...PUMA
SHORT TERM...50
LONG TERM...MK
AVIATION...MK
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
622 AM EDT TUE MAR 15 2016
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 326 AM EDT TUE MAR 15 2016
A COLD FRONT WILL BRING CHANCES FOR THUNDERSTORMS LATE THIS
AFTERNOON AND TONIGHT...AND SOME COULD BE SEVERE. LATER IN THE WEEK
AND INTO THE WEEKEND...AN UPPER LEVEL SYSTEM WILL BRING CHANCES FOR
SHOWERS. WARM TEMPERATURES TODAY WILL COOL TO BELOW AVERAGE BY THE
WEEKEND.
&&
.NEAR TERM.../TODAY/
ISSUED AT 326 AM EDT TUE MAR 15 2016
FIRST PROBLEM TO DEAL WITH IS FOG. PATCHY DENSE FOG HAS DEVELOPED
ACROSS THE SOUTHWEST FORECAST AREA WHERE SKIES HAVE CLEARED FOR NOW.
LATEST SURFACE OBSERVATIONS THOUGH SHOW HIGH VARIABILITY IN THE
FOG...AND SATELLITE SHOWS INCREASING HIGH CLOUDS MOVING IN. THUS FOR
NOW WILL HOLD OFF ANY ADVISORY AND CONTINUE WITH A SPECIAL WEATHER
STATEMENT.
BELIEVE LOWER CLOUDS WILL BREAK UP SOME DURING THE MORNING...BUT
MORE MID AND HIGH CLOUDS WILL MOVE IN WITH A WARM FRONT MOVING NORTH
TODAY. WILL KEEP SKIES PARTLY TO MOSTLY CLOUDY TODAY.
SOME ISENTROPIC LIFT WILL OCCUR TODAY WITH THE WARM FRONT...BUT DO
NOT FEEL THAT THIS FORCING WILL BE ENOUGH TO GO WITH POPS FOR MOST
OF THE DAY. WOULD NOT BE SURPRISED TO SEE SOME SPRINKLES
THOUGH...ESPECIALLY NORTH.
MODELS HAVE CONTINUED THE SLOW DOWN THE SYSTEM AND APPROACH OF THE
COLD FRONT...AND MOST MODELS ARE DRY THROUGH 00Z. COMPROMISED TO
KEEP CONSISTENCY WITH PREVIOUS FORECAST AND WENT SLIGHT CHANCE POPS
ACROSS THE FAR NORTHWEST AFTER 21Z.
TEMPERATURES WILL BE IN QUESTION TODAY WITH SLOWER MOVEMENT OF WARM
FRONT AND UNCERTAINTIES WITH CLOUD COVER. IF CLOUDS BREAK AND ALLOW
PLENTY OF SUNSHINE...LATE DAY HIGHS IN THE MID TO UPPER 70S ACROSS
LARGE PARTS OF THE AREA ARE POSSIBLE. HOWEVER WOULD RATHER ERR ON
COOLER/PESSIMISTIC SIDE. WENT WITH A BLEND WHICH PUTS HIGHS IN UPPER
60S NORTHEAST TO MID 70S SOUTHWEST.
&&
.SHORT TERM.../TONIGHT THROUGH THURSDAY NIGHT/
ISSUED AT 326 AM EDT TUE MAR 15 2016
FOCUS IS ON RAIN CHANCES THROUGH THE PERIOD AND SEVERE WEATHER
TONIGHT. GENERALLY STUCK WITH A MODEL BLEND...BUT GFS SEEMS TOO
AGGRESSIVE WITH UPPER LOW MOVING SOUTH LATE. TRENDED AWAY FROM GFS
THEN.
FRONT WILL MOVE THROUGH THE AREA MID EVENING INTO THE OVERNIGHT.
STILL GOOD SHEAR ACROSS THE AREA...BUT INSTABILITY IS MORE IN
QUESTION GIVEN THE TIME OF DAY. AGREE WITH STORM PREDICTION CENTER
FORECAST OF MOVING THE SLIGHT RISK NORTH AND WEST.
STRONG FORCING WITH UPPER TROUGH AND AN UPPER JET SHOULD LEAD TO
LIKELY POPS ACROSS THE NORTH THIRD OR SO OF THE AREA TONIGHT. MODEL
REFLECTIVITY FORECASTS SHOW MORE OF A BROKEN LINE OF CONVECTION
SOUTH 2/3 OF THE AREA...SO WENT CHANCE POPS THERE.
ALL RAIN SHOULD BE OUT OF THE AREA BY 12Z WEDNESDAY...AND UPPER
TROUGH WILL REMAIN WELL TO THE NORTH. WENT WITH A DRY FORECAST. A
WEAK UPPER IMPULSE WILL MOVE THROUGH THE AREA WEDNESDAY NIGHT...SO
KEPT SLIGHT CHANCE POPS MOST AREAS FOR THAT TIME FRAME.
WENT WITH A DRY FORECAST THURSDAY AND THURSDAY NIGHT WITH THE UPPER
TROUGH STAYING TO THE NORTH.
OTHER ITEM OF CONCERN IS WINDS BEHIND THE FRONT WEDNESDAY. STRONG
WINDS ALOFT LOOK TO MIX DOWN SOME WITH SUNSHINE EXPECTED. WIND GUSTS
AROUND 40 MPH /AND POTENTIALLY HIGHER PER SOME MODEL BUFKIT
SOUNDINGS/ ARE POSSIBLE. WILL KEEP AN EYE ON IT AND MENTION IT IN
THE HAZARDOUS WEATHER OUTLOOK FOR NOW.
GENERALLY STUCK WITH A MODEL BLEND FOR TEMPERATURES THROUGH THE
PERIOD.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
ISSUED AT 224 AM EDT TUE MAR 15 2016
COOLER TEMPERATURES AND SHOWER CHANCES ARE IN STORE THROUGH THE
WEEKEND WITH DRY WEATHER LIKELY TO START NEXT WEEK.
00Z OPERATIONAL MODELS ARE IN GOOD AGREEMENT THAT A FRONT WILL BE
NEARBY ON FRIDAY...AND THERE WILL BE ENOUGH MOISTURE TO SQUEEZE OUT
A FEW LIGHT SHOWERS OR SPRINKLES FRIDAY. THEN...THINGS CHANGE AS THE
GFS IS MUCH QUICKER TO BRING AN UPPER SYSTEM OVER THE AREA THEN THE
ECMWF. DESPITE THIS...BOTH MODELS HAVE QPF OVER CENTRAL THROUGH
SUNDAY AS DOES THE REGIONAL BLEND. WITH THAT IN MIND...WILL KEEP
SHOWER CHANCES GOING. FRIDAY NIGHT THROUGH SUNDAY WITH THE BEST
CHANCES SATURDAY AND SATURDAY NIGHT. LOW LEVEL THICKNESSES SUPPORT A
MIX AND OR CHANGEOVER TO SNOW OVERNIGHT FRIDAY NIGHT AND EARLY
SATURDAY AND OVERNIGHT SATURDAY NIGHT AND EARLY SUNDAY. THE GROUND
WILL BE TOO WARM FOR EVEN A MINOR SNOW ACCUMULATION...HOWEVER. AFTER
THAT...SURFACE HIGH PRESSURE WILL BUILD OVER THE AREA ON MONDAY AND
RESULT IN DRY WEATHER.
WITH MODEL DIFFERENCES...WILL NOT STRAY FAR FROM THE REGIONAL BLEND
WITH BELOW NORMAL TEMPERATURES BY SATURDAY.
&&
.AVIATION /DISCUSSION FOR THE 15/12Z TAF ISSUANCE/...
ISSUED AT 622 AM EDT TUE MAR 15 2016
THE FOG SHOULD DISSIPATE BY 15Z AT BMG AND HUF PER LAMP MOS AS
SURFACE PRESSURE GRADIENT STARTS TO TIGHTEN AHEAD OF AN APPROACHING
MISSOURI VALLEY LOW PRESSURE SYSTEM. MEANWHILE...THICK STRATUS
DECK...NEAR AND NORTH OF IND-LAF QUASI-STATIONARY FRONT...WILL
GRADUALLY LIFT TO NEAR 3K FEET BY THIS AFTERNOON WITH DIURNAL CU
DEVELOPING SOUTH OF THAT LINE WITH MVFR CEILINGS APPROACHING 3K
FEET. ANY IFR CONDITIONS SHOULD IMPROVE AT IND AND LAF BY 13Z.
CONFIDENCE IN EXACT TIMING IS NOT GREAT BUT CONFIDENCE IN TRENDS IS
GOOD. COULD ALSO SEE CEILINGS IMPROVE TO VFR AROUND 21Z FOR A FEW
HOURS BEFORE CONVECTION MOVES IN. MODELS INCLUDING THE HRRR SUGGEST
ANY STORMS WILL HOLD OFF UNTIL AFTER 00Z WEDNESDAY AT HUF AND LAF
AND LATER STILL AT IND AND BMG. WILL BRING IN A PROB30 MVFR THUNDER
GROUP 01Z-07Z. WILL ALSO GO WITH CONVECTIVE GUSTS AS HIGH AS 40
KNOTS. THE CLOUDS WILL BE DECREASING BEHIND THE COLD FRONT THAT
SHOULD MOVE THROUGH 05Z-09Z.
WINDS WILL GRADUALLY PICK UP FROM THE SOUTHEAST AFTER 13Z. WINDS
WILL INCREASE TO AROUND 10 KNOTS OR SO WITH GUSTS TO NEAR 20 KNOTS
AFTER 18Z. WINDS WILL SHIFT TO THE SOUTHWEST AND WEST BEHIND THE
COLD FRONT AND INCREASE TO AROUND 15 KNOTS WITH GUSTS TO NEAR 25
KNOTS OVERNIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...50
NEAR TERM...50
SHORT TERM...50
LONG TERM...MK
AVIATION...MK
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
717 AM EDT TUE MAR 15 2016
.SYNOPSIS...
AN UPPER TROUGH WILL FILL AND PUSH EAST OF THE AREA THIS MORNING.
HOWEVER...CLOUDS WILL PREVAIL OVER MUCH OF THE AREA THROUGH THE
DAY. A WARM FRONT WILL LIFT THROUGH THE STATE ON
WEDNESDAY...FOLLOWED VERY SHORTLY BY A COLD FRONT. COOLER AND
UNSETTLED CONDITIONS WITH SCATTERED RAIN SHOWERS WILL FOLLOW FOR
THE END OF THE WEEK AND INTO WEEKEND. THE RAIN SHOWERS LATE THIS
WEEK WILL MIX WITH WET SNOW...ESPECIALLY OVERNIGHTS ON THE
RIDGES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SHOWERS TRYING TO ENTER THE WESTERN COUNTIES AT 5 AM...BUT HAVING
MORE LUCK OVER THE SC MTNS. 00Z NAM AND MOST HRRR AND RAP RUNS UP
TO THIS POINT DID WELL AT PLACING PRECIP. BUT RECENT RUNS HAVE
BEEN LESS IMPRESSIVE. STILL A GENERALLY SHOWERY/DRIZZLY DAY IS
FORECAST AS THE WIND ONLY GRADUALLY BECOMES WESTERLY BEHIND THE
PASSAGE OF A VERY WEAK TROUGH. WILL MENTION PATCHY FOG/DZ INTO THE
MORNING...THEN JUST CALL IT SHOWERS. POPS WILL BE HIGHEST IN THE
MORNING DUE TO MORE CERTAINTY TRACKING CURRENT RADAR AND SAT
FEATURES. NEAT MCV VISIBLE IN THE RADAR DATA BACK AROUND MIDNIGHT
OVER THE WRN PART OF THE STATE AND NOW ONE IS ROLLING NORTHWARD
THROUGH THE SC MTNS...GENERATED BY CONVECTION OVER CENTRAL V
EARLIER TONIGHT. PRECIP SEEMS NOT SO CERTAIN AS HIGH PRESSURE
STARTS TO BUILD IN FROM THE WEST THROUGH THE DAY. HOWEVER...THE
NRN TIER WILL HAVE THE HIGHEST /CHC/ POPS IN THE AFTN. HAVE TAKEN
A FEW DEGS OFF THE MAX TEMPS OVER THE NRN AND CENTRAL MTNS FROM
PREV FCSTS AND MOS SINCE THE CLOUDS DO LOOK TOUGH TO SCOUR OUT.
WOULD NOT BE SURPRISED TO SEE THEM NEED TO BE ADJUSTED DOWNWARD A
NOTCH OR TWO LATER TODAY. BUT PEEKS OF SUN ARE STILL POSSIBLE -
MAINLY S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
HIGH PRESSURE SLIDES OVERHEAD TONIGHT...BUT LITTLE CHANGE IN SKY
COVER IS EXPECTED OVER THE NRN HALF OF THE AREA. THERE WILL LIKELY
BE SOME CLEARING IN THE SRN HALF...BUT IT WILL BE SHORT-LIVED AS A
WARM FRONT APPROACHES FROM THE SW LATER IN THE NIGHT. DIURNAL
SWING WILL BE VERY SMALL IN THE N - BUT CLOSER TO 10-12F OVER THE
SRN TIER. MOST PLACES WILL BOTTOM OUT IN THE M40S.
ENOUGH INSTABILITY MAY DEVELOP IN THE PARTIAL CLEARING WHICH COULD
OCCUR AHEAD OF THE WARM FRONT ON WED. SPC HAS US IN GENERAL
THUNDER - AND A QUICK LOOK AT THE HODOGRAPH AND VERY LOW LCLS IN
PROXIMITY TO THE WARM FRONT MAKE IT SEEM LIKE IT COULD BE MORE
INTERESTING /ROTATING CELLS??/ THAN A BENIGN MENTION OF T. 0-3KM
EHI/S START TO SHOW UP IN A NARROW STRIPE NEAR THE WARM FRONT.
HOWEVER...WE WILL PROBABLY BE LIMITED IN HEATING AND HAVE HIGHER
STABILITY THAN WHAT IT WOULD TAKE TO GENERATE DEEP CONVECTION AND
REALIZE THE POTENTIAL OF THE STORMS THAT DAY. WILL MENTION THUNDER
FOR WED. ANOTHER FEW RUNS WILL HELP DETERMINE JUST HOW UNSTABLE WE
CAN GET. THE COLD FRONT ZIPS RIGHT IN BEHIND THE OTHER
FRONT...AND COULD PROVIDE EXTRA LIFT AND DRY AIR. IT WILL ALSO
SERVE TO EFFECTIVELY CUT OFF PRECIP LATER IN THE DAY. MOST OF THE
SHOWERS WILL BE OFF TO THE EAST BEFORE SUNSET WED.
WED NIGHT IS A TOUGH CALL ON TEMPS AS THE SKY COVER WILL VARY
GREATLY THROUGH THE NIGHT WITH SOME INITIAL CLEARING THEN A RETURN
OF MOISTURE AND PERHAPS A SHOWER LATE AT NIGHT OVER THE WEST.
ALSO...THE WINDS BECOME SWRLY BEHIND THE COLD FRONT. 8H TEMPS INCH
DOWN THROUGH THE NIGHT. BUT THE DEW POINTS DO NOT GET OUT OF THE
WAY TO ALLOW FOR A REALLY GOOD TEMP DROP. OF COURSE...THE USUAL
COLD SPOTS IN THE EAST LIKE KSEG AND KTHV WHERE RADIATIONAL
COOLING SEEMS TO MAXIMIZED IN ALL SITUATIONS COULD DROP OFF
NICELY.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
THE INITIAL BLOCKING PATTERN OVER SRN CANADA AND THE NRN CONUS
WILL ULTIMATELY EVOLVE INTO A CNTRL-ERN U.S. MEAN TROUGH THAT
COULD SUPPORT A STRONGLY DEVELOPING SFC SYSTEM IN THE MID-ATLANTIC
AND NORTHEAST STATES THIS WEEKEND INTO MONDAY. THERE ARE STILL
IMPORTANT MODEL DIFFERENCES THAT REMAIN UNRESOLVED WITH INDIVIDUAL
ENSEMBLE MEMBERS VERY DISPERSED SUN-MON IN A LOW TRACK RANGING
FROM WELL INLAND TO OFFSHORE. THEREFORE THE DEGREE OF CERTAINTY OR
CONFIDENCE IN FORECAST DETAILS IS LOW/BELOW AVERAGE AT THIS TIME.
SENSIBLE WEATHER HIGHLIGHTS WILL BE A SEASONABLE COOLING TREND BY
THE END OF THE PERIOD FROM THE MID-WEEK PEAK/ANOMALOUS WARMTH.
THERE IS A LARGE SPREAD IN THE SFC LOW TRACK LATE IN THE PERIOD
WHICH TEMPERS CONFIDENCE IN DETERMINING PRECIP EXTENT/TIMING AND
TYPE. A LATE SEASON SNOW EVENT IS A POSSIBLE OUTCOME BUT THE ODDS
ARE VERY LOW AT THIS POINT.
&&
.AVIATION /11Z TUESDAY THROUGH SATURDAY/...
NO BIG CHANGES FOR 12Z TAFS.
TWO AREAS OF SHOWERS...ONE TO THE WEST...ANOTHER ONE TO THE
SOUTH...AS OF 7 AM.
SOME MODEST IMPROVEMENT EXPECTED THIS AFT...AS THE MOIST SE
FLOW WEAKENS...AND WEAK WESTERLY FLOW DEVELOPS...AS A WEAK UPPER
LVL TROUGH MOVES ACROSS THE REGION.
PARTIAL CLEARING THIS AFTERNOON COULD RESULT IN SOME FOG
TONIGHT.
OUTLOOK...
WED...AM FOG POSSIBLE. ISOLD PM TSRA IMPACTS POSSIBLE.
THU...NO SIG WX EXPECTED.
FRI...SHSN/VIS REDUCTIONS POSS W MTNS.
SAT...NO SIG WX EXPECTED.
&&
.CLIMATE...
BEEN COOLER THE LAST FEW DAYS...BUT STILL ABOVE NORMAL.
MUCH ABOVE THE RECORD LOWS SET BEHIND THE BLIZZARD OF
1993.
RECORDS FOR TODAY...TUESDAY MARCH 15TH.
WILLIAMSPORT RECORD LOW OF JUST 2 ABOVE ZERO SET IN 1993.
HARRISBURG RECORD LOW OF JUST 7 ABOVE ZERO SET IN 1993.
JUST A REMINDER OF HOW COLD IT CAN STILL GET IN MID MARCH.
THERE HAS BEEN A LACK OF MAJOR WINTER STORMS IN MARCH AND
APRIL SINCE 1994. SOME OF THE BIGGER STORMS HAVE OCCURRED
IN MARCH AND APRIL.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...STEINBUGL
AVIATION...MARTIN
CLIMATE...MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
624 AM EDT TUE MAR 15 2016
.SYNOPSIS...
AN UPPER TROUGH WILL FILL AND PUSH EAST OF THE AREA THIS MORNING.
HOWEVER...CLOUDS WILL PREVAIL OVER MUCH OF THE AREA THROUGH THE
DAY. A WARM FRONT WILL LIFT THROUGH THE STATE ON
WEDNESDAY...FOLLOWED VERY SHORTLY BY A COLD FRONT. COOLER AND
UNSETTLED CONDITIONS WITH SCATTERED RAIN SHOWERS WILL FOLLOW FOR
THE END OF THE WEEK AND INTO WEEKEND. THE RAIN SHOWERS LATE THIS
WEEK WILL MIX WITH WET SNOW...ESPECIALLY OVERNIGHTS ON THE
RIDGES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SHOWERS TRYING TO ENTER THE WESTERN COUNTIES AT 5 AM...BUT HAVING
MORE LUCK OVER THE SC MTNS. 00Z NAM AND MOST HRRR AND RAP RUNS UP
TO THIS POINT DID WELL AT PLACING PRECIP. BUT RECENT RUNS HAVE
BEEN LESS IMPRESSIVE. STILL A GENERALLY SHOWERY/DRIZZLY DAY IS
FORECAST AS THE WIND ONLY GRADUALLY BECOMES WESTERLY BEHIND THE
PASSAGE OF A VERY WEAK TROUGH. WILL MENTION PATCHY FOG/DZ INTO THE
MORNING...THEN JUST CALL IT SHOWERS. POPS WILL BE HIGHEST IN THE
MORNING DUE TO MORE CERTAINTY TRACKING CURRENT RADAR AND SAT
FEATURES. NEAT MCV VISIBLE IN THE RADAR DATA BACK AROUND MIDNIGHT
OVER THE WRN PART OF THE STATE AND NOW ONE IS ROLLING NORTHWARD
THROUGH THE SC MTNS...GENERATED BY CONVECTION OVER CENTRAL V
EARLIER TONIGHT. PRECIP SEEMS NOT SO CERTAIN AS HIGH PRESSURE
STARTS TO BUILD IN FROM THE WEST THROUGH THE DAY. HOWEVER...THE
NRN TIER WILL HAVE THE HIGHEST /CHC/ POPS IN THE AFTN. HAVE TAKEN
A FEW DEGS OFF THE MAX TEMPS OVER THE NRN AND CENTRAL MTNS FROM
PREV FCSTS AND MOS SINCE THE CLOUDS DO LOOK TOUGH TO SCOUR OUT.
WOULD NOT BE SURPRISED TO SEE THEM NEED TO BE ADJUSTED DOWNWARD A
NOTCH OR TWO LATER TODAY. BUT PEEKS OF SUN ARE STILL POSSIBLE -
MAINLY S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
HIGH PRESSURE SLIDES OVERHEAD TONIGHT...BUT LITTLE CHANGE IN SKY
COVER IS EXPECTED OVER THE NRN HALF OF THE AREA. THERE WILL LIKELY
BE SOME CLEARING IN THE SRN HALF...BUT IT WILL BE SHORT-LIVED AS A
WARM FRONT APPROACHES FROM THE SW LATER IN THE NIGHT. DIURNAL
SWING WILL BE VERY SMALL IN THE N - BUT CLOSER TO 10-12F OVER THE
SRN TIER. MOST PLACES WILL BOTTOM OUT IN THE M40S.
ENOUGH INSTABILITY MAY DEVELOP IN THE PARTIAL CLEARING WHICH COULD
OCCUR AHEAD OF THE WARM FRONT ON WED. SPC HAS US IN GENERAL
THUNDER - AND A QUICK LOOK AT THE HODOGRAPH AND VERY LOW LCLS IN
PROXIMITY TO THE WARM FRONT MAKE IT SEEM LIKE IT COULD BE MORE
INTERESTING /ROTATING CELLS??/ THAN A BENIGN MENTION OF T. 0-3KM
EHI/S START TO SHOW UP IN A NARROW STRIPE NEAR THE WARM FRONT.
HOWEVER...WE WILL PROBABLY BE LIMITED IN HEATING AND HAVE HIGHER
STABILITY THAN WHAT IT WOULD TAKE TO GENERATE DEEP CONVECTION AND
REALIZE THE POTENTIAL OF THE STORMS THAT DAY. WILL MENTION THUNDER
FOR WED. ANOTHER FEW RUNS WILL HELP DETERMINE JUST HOW UNSTABLE WE
CAN GET. THE COLD FRONT ZIPS RIGHT IN BEHIND THE OTHER
FRONT...AND COULD PROVIDE EXTRA LIFT AND DRY AIR. IT WILL ALSO
SERVE TO EFFECTIVELY CUT OFF PRECIP LATER IN THE DAY. MOST OF THE
SHOWERS WILL BE OFF TO THE EAST BEFORE SUNSET WED.
WED NIGHT IS A TOUGH CALL ON TEMPS AS THE SKY COVER WILL VARY
GREATLY THROUGH THE NIGHT WITH SOME INITIAL CLEARING THEN A RETURN
OF MOISTURE AND PERHAPS A SHOWER LATE AT NIGHT OVER THE WEST.
ALSO...THE WINDS BECOME SWRLY BEHIND THE COLD FRONT. 8H TEMPS INCH
DOWN THROUGH THE NIGHT. BUT THE DEW POINTS DO NOT GET OUT OF THE
WAY TO ALLOW FOR A REALLY GOOD TEMP DROP. OF COURSE...THE USUAL
COLD SPOTS IN THE EAST LIKE KSEG AND KTHV WHERE RADIATIONAL
COOLING SEEMS TO MAXIMIZED IN ALL SITUATIONS COULD DROP OFF
NICELY.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
THE INITIAL BLOCKING PATTERN OVER SRN CANADA AND THE NRN CONUS
WILL ULTIMATELY EVOLVE INTO A CNTRL-ERN U.S. MEAN TROUGH THAT
COULD SUPPORT A STRONGLY DEVELOPING SFC SYSTEM IN THE MID-ATLANTIC
AND NORTHEAST STATES THIS WEEKEND INTO MONDAY. THERE ARE STILL
IMPORTANT MODEL DIFFERENCES THAT REMAIN UNRESOLVED WITH INDIVIDUAL
ENSEMBLE MEMBERS VERY DISPERSED SUN-MON IN A LOW TRACK RANGING
FROM WELL INLAND TO OFFSHORE. THEREFORE THE DEGREE OF CERTAINTY OR
CONFIDENCE IN FORECAST DETAILS IS LOW/BELOW AVERAGE AT THIS TIME.
SENSIBLE WEATHER HIGHLIGHTS WILL BE A SEASONABLE COOLING TREND BY
THE END OF THE PERIOD FROM THE MID-WEEK PEAK/ANOMALOUS WARMTH.
THERE IS A LARGE SPREAD IN THE SFC LOW TRACK LATE IN THE PERIOD
WHICH TEMPERS CONFIDENCE IN DETERMINING PRECIP EXTENT/TIMING AND
TYPE. A LATE SEASON SNOW EVENT IS A POSSIBLE OUTCOME BUT THE ODDS
ARE VERY LOW AT THIS POINT.
&&
.AVIATION /10Z TUESDAY THROUGH SATURDAY/...
TWO AREAS OF SHOWERS...ONE TO THE WEST...ANOTHER ONE TO THE
SOUTH...AS OF 6 AM.
09Z TAFS SENT.
SOME MODEST IMPROVEMENT EXPECTED THIS AFT...AS THE MOIST SE
WEAKENS...AND WEAK WESTERLY FLOW DEVELOPS...AS A WEAK UPPER
LVL TROUGH MOVES ACROSS THE REGION.
PARTIAL CLEARING THIS AFTERNOON COULD RESULT IN SOME FOG
TONIGHT.
OUTLOOK...
WED...AM FOG POSSIBLE. ISOLD PM TSRA IMPACTS POSSIBLE.
THU...NO SIG WX EXPECTED.
FRI...SHSN/VIS REDUCTIONS POSS W MTNS.
SAT...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...STEINBUGL
AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
620 AM CDT TUE MAR 15 2016
.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 324 AM CDT TUE MAR 15 2016
VERY ACTIVE AND BUSY WEATHER SCENARIO SET TO IMPACT THE AREA OVER
THE NEXT COUPLE OF DAYS.
WATER VAPOR IMAGERY SHOWS DEEPENING MID-LEVEL TROUGH COMING OUT OF
THE INTERMOUNTAIN WEST INTO THE HIGH PLAINS. AT THE SURFACE...LOW
PRESSURE WAS ORGANIZING ITSELF ACROSS THE NORTHERN INTO THE CENTRAL
PLAINS. WARM AIR ADVECTION/ISENTROPIC LIFT/MOISTURE TRANSPORT AHEAD
OF THIS TROUGH/SURFACE LOW WAS PRODUCING AN ELONGATED BAND OF
SHOWERS AND THUNDERSTORMS FROM WESTERN MN THROUGH WESTERN IA. A
SMALLER BAND OF SHOWERS/STORMS WAS ALSO MOVING NORTHEAST ACROSS
SOUTHEAST MN/NORTHEAST IA/FAR SOUTHWEST WI PER LATEST RADAR MOSAIC.
OTHERWISE...A VERY MILD NIGHT ACROSS THE AREA WITH TEMPERATURES AS
OF 2 AM IN THE UPPER 40S/LOWER 50S UNDER MOSTLY CLOUDY SKIES.
FOR TODAY...LOW PRESSURE WILL CONTINUE MOVING EASTWARD TOWARD THE
AREA WITH SHOWER/THUNDERSTORMS MOVING IN. EXPECTING STORMS TO
REMAIN WELL-BEHAVED THROUGH MUCH OF TODAY...BUT A FEW STRONGER
STORMS MAY MATERIALIZE ACROSS PORTIONS OF NORTHEAST IA INTO FAR
SOUTHWEST WI LATER THIS AFTERNOON INTO THIS EVENING AS MODELS SHOW
INTENSE CYCLOGENESIS TAKE PLACE OVER EASTERN IA. THIS WRAPS SOME
ELEVATED CAPE AHEAD OF IT INTO NORTHERN IL DURING THIS TIME
FRAME...WITH OUR AREA ON THE VERY NORTHERN FRINGES OF SOME WEAKER
CAPE. APPEARS SEVERE THREAT WILL REMAIN SOUTH/EAST OF OUR AREA AS A
RESULT. CANNOT RULE OUT A FEW STRONGER STORMS THOUGH WITH SMALL HAIL
AND GUSTY WIND.
INTENSE/DEEPENING SURFACE LOW THEN TRACKS NORTHEAST ACROSS THE AREA
TONIGHT WITH A RAPIDLY TIGHTENING PRESSURE GRADIENT. SO WILL GET A
DOUBLE WHAMMY FROM THIS SYSTEM WITH 1. HEAVIER RAIN IN THE
STRENGTHENING DEFORMATION AREA NORTHWEST/WEST OF THE LOW LINING UP
ALONG THE MISSISSIPPI RIVER AND 2. VERY STRONG NORTHWEST/WEST
SURFACE WINDS DEVELOPING TOWARD MORNING.
RAINFALL FROM TODAY INTO TONIGHT LOOKS TO BE IN THE 1-2.5 INCH RANGE
WITH PERHAPS A FEW POCKETS OF LOCALLY HIGHER AMOUNTS. 6 HOURLY FLASH
FLOOD GUIDANCE IN THE 2-3.5 INCH RANGE...SO THINKING GROUND SHOULD
ABSORB MOST OF THIS WITH MINIMAL RUNOFF FOR HYDROLOGY/RIVER
CONCERNS.
ATTENTION THEN TURNS TO HIGH WIND POTENTIAL VERY LATE TONIGHT
THROUGH WEDNESDAY. NAM SHOWS CORRIDOR OF 850-925MB LAYER WINDS OF 45-
55KT SWINGING SOUTHEAST THROUGH SOUTHEAST MN/NORTHEAST IA/SOUTHERN
WI ON THE BACKSIDE OF THE DEEPENING LOW WEDNESDAY. BELIEVE WITH COLD
AIR ADVECTION/DOWNWARD MOMENTUM...THESE WINDS COULD REACH THE
SURFACE IN GUSTS. AS SUCH...HAVE HOISTED A HIGH WIND WATCH FOR
PORTIONS OF SOUTHEAST MN/NORTHEAST IA/SOUTHWEST WI FROM 4 AM
WEDNESDAY TIL 8 PM THURSDAY.
FOR WEDNESDAY NIGHT...TEMPS COOL ENOUGH INTO THE 30S ACROSS THE AREA
FOR A RAIN/SNOW MIX ACROSS THE AREA. COULD SEE SOME LIGHT SLUSHY
SNOW ACCUMULATIONS MAINLY ON GRASSY SURFACES. FARTHER NORTH...NORTH
OF HIGHWAY 29...COULD SEE UPWARDS OF 1-2 INCHES.
TEMPERATURE-WISE...LOOK FOR HIGHS TODAY IN THE 50S/LOWER 60S...THEN
FALLING OFF INTO THE 40S/LOWER 50S WEDNESDAY.
.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 324 AM CDT TUE MAR 15 2016
BREEZY COOLER CONDITIONS WILL BE SEEN THURSDAY/THURSDAY NIGHT WITH
SCATTERED RAIN/SNOW SHOWERS.
LOOKS MAINLY DRY ON FRIDAY WITH THE EXCEPTION OF SOUTH OF I-90 WHERE
A SLIGHT CHANCE OF SHOWERS WILL STILL EXIST.
A COUPLE OF TROUGHS ROTATE THROUGH THE REGION OVER THE WEEKEND FOR
SOME SMALL-END CHANCE SHOWERS.
OTHERWISE...COOLER/NEAR NORMAL TEMPERATURES TO CONTINUE WITH HIGHS
MAINLY IN THE 40S AND LOWS IN THE MID 20S TO LOWER 30S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 620 AM CDT TUE MAR 15 2016
SHOWERS AND STORMS CONTINUE TO BLOSSOM THIS MORNING IN A REGION OF
ISENTROPIC UP GLIDE. THE HRRR HAS BEEN DOING A DECENT JOB WITH
THIS ACTIVITY AND SHOWS IT LIFTING TO THE NORTH AND NORTHEAST AND
PAST BOTH TAF SITES BY LATE MORNING OR EARLY AFTERNOON. WILL
INCLUDE THE MENTION OF THUNDER THROUGH ABOUT THE MIDDLE OF THE
MORNING AND UPDATE LATER IF IT IS NEEDED AFTER THAT. CEILINGS
SHOULD COME DOWN AS THE COLUMN SATURATES WITH IFR EXPECTED AT KRST
AND MVFR AT KLSE. EXPECTING A BREAK IN THE RAIN FOR A WHILE THIS
AFTERNOON BEFORE THE NEXT ROUND MOVES IN WITH THE APPROACH OF THE
SURFACE LOW FROM MISSOURI. EXPECT MVFR VISIBILITIES IN THIS NEXT
ROUND OF SHOWERS WITH IFR CEILINGS. AS THE LOW APPROACHES...IT
WILL BE DEEPENING RAPIDLY WHICH WILL CAUSE THE WINDS TO COME
AROUND TO THE NORTH AND THEN NORTHWEST AT KRST. SPEEDS WILL START
TO INCREASE...ESPECIALLY AT KRST WHERE GUSTS OF 40 KNOTS WILL BE
POSSIBLE FOR LATE TONIGHT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...HIGH WIND WATCH FROM LATE TONIGHT THROUGH WEDNESDAY EVENING FOR
WIZ041-053>055-061.
MN...HIGH WIND WATCH FROM LATE TONIGHT THROUGH WEDNESDAY EVENING FOR
MNZ086>088-094>096.
IA...HIGH WIND WATCH FROM LATE TONIGHT THROUGH WEDNESDAY EVENING FOR
IAZ008>011-018-019-029-030.
&&
$$
SHORT TERM...DAS
LONG TERM...DAS
AVIATION...04
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
326 PM CDT TUE MAR 15 2016
.SHORT TERM...
320 PM CDT
TONIGHT THROUGH WEDNESDAY NIGHT...
PRIMARY FORECAST FOCUS IS WITH SEVERE WEATHER POTENTIAL THROUGH
THIS EVENING...AND VERY WINDY CONDITIONS DEVELOPING LATER TONIGHT
AND CONTINUING THROUGH WEDNESDAY NIGHT.
SFC LOW PRESSURE WAS DEEPENING ACROSS NORTHEASTERN MISSOURI EARLY
THIS AFTERNOON...IN RESPONSE TO A VIGOROUS MID-LEVEL SHORT WAVE
PROPAGATING ACROSS EASTERN KANSAS AND INTO THE MID-MISSOURI RIVER
VALLEY PER GOES WATER VAPOR IMAGERY. SOUTH-SOUTHEAST LOW LEVEL
RETURN FLOW PRODUCING IMPRESSIVE WARM SECTOR AIR MASS FOR MID-
MARCH... CHARACTERIZED BY AIR TEMPS IN THE LOW-MID 70S AND SURFACE
DEW POINTS OF 55-60 INTO CENTRAL IL/WEST CENTRAL IN INCLUDING
SOUTHERN COUNTIES OF THE WFO LOT CWA. WHILE SURFACE FLOW IS BACKED
TO THE SOUTHEAST ACROSS THE AREA...THE EFFECTIVE SURFACE WARM
FRONT APPEARS TO BE APPROXIMATELY NEAR A GALESBURG-PONTIAC-
LAFAYETTE LINE. CONSIDERABLE SUNSHINE WAS HELPING TO DESTABILIZE
THE AIR MASS ACROSS THE MISSISSIPPI VALLEY AND CENTRAL IL...WITH
SPC RAP ANALYSIS INDICATING MLCAPES INCREASING TO 1000-1500 J/KG
WITH CIN WEAKENING TO 100 J/KG OR LESS. DYNAMICS ARE BECOMING MORE
FAVORABLE FOR SEVERE CONVECTION AS WELL WITH APPROACH OF STRONG
MID-LEVEL WAVE...WITH 60 KT EFFECTIVE DEEP LAYER BULK SHEAR AND
0-3 KM STORM RELATIVE HELICITY OF 200-300 M2S2 IN THE VICINITY OF
THE WARM FRONTAL BOUNDARY. VISIBLE SATELLITE DEPICTS INCREASING CU
FIELD ALONG THE MISSISSIPPI RIVER AND INTO NORTHEAST
MISSOURI...WHERE STORM INITIATION IS EXPECTED OVER THE NEXT FEW
HOURS AND HAS BEEN INDICATED BY HIGH-RES GUIDANCE. ENVIRONMENT
PRIMED FOR SUPERCELL DEVELOPMENT...AND RECENT SPC MCD INDICATES
TORNADO WATCH LIKELY IN THE NEXT FEW HOURS WITHIN THE ENHANCED
RISK AREA TO OUR WEST/SOUTHWEST. BASED ON HIGH RES
GUIDANCE...EVOLUTION STILL APPEARS TO BE INITIATION 22-23Z TO OUR
WEST AND SOUTHWEST... WITH STORMS THEN SPREADING NORTHEAST INTO
THE FORECAST AREA AFTER 7-8 PM. LARGE HAIL...DAMAGING WIND AND
ISOLATED TORNADO THREAT WILL EXIST WITH SUPERCELLULAR STORMS
MOVING INTO THE CWA INITIALLY WITH OUR IL COUNTIES ALONG/SOUTH OF
I-80 LIKELY UNDER THE HIGHEST RISK. WIND AND TORNADO
THREAT...WHILE NOT ZERO...WILL LIKELY DIMINISH FURTHER NORTHEAST
INTO THE CHICAGO METRO WITH SOME DECREASE IN INTENSITY OF STORMS
POSSIBLE WITH GRADUAL DIURNAL DECREASE IN INSTABILITY. THE
POTENTIAL FOR SEVERE WEATHER WILL EXIST HOWEVER ALL THE WAY TO
LAKE MICHIGAN AND OUR EASTERN CWA COUNTIES AND STORMS ARRIVE IN
THE 9-10 PM TIME FRAME AND LAST THROUGH ABOUT MIDNIGHT OR 1 AM AS
THE SURFACE LOW LIFTS NORTHEAST INTO WISCONSIN AND ITS STRONG
TRAILING COLD FRONT PUSHES THROUGH THE AREA. SCATTERED SHOWERS OR
EVEN ISOLATED THUNDERSTORMS WILL LIKELY LINGER OVER PARTS OF NORTH
CENTRAL ILLINOIS AND THE IL/WI BORDER REGION AS THE UPPER TROUGH
LIFTS ACROSS THE AREA OVERNIGHT. SOME POTENTIAL FOR A FEW HIGH-
BASED INSTABILITY SHOWERS WEDNESDAY AFTERNOON NEAR THE WISCONSIN
BORDER WITH DEEP ADIABATIC LAPSE RATES.
WINDS WILL VEER FROM THE SOUTHEAST TO THE WEST-SOUTHWEST BEHIND
THE FRONT OVERNIGHT...INCREASING IN SPEED AND BECOMING GUSTY TO
40-45 MPH BY MORNING. MODEL FORECAST SOUNDINGS CONTINUE TO DEPICT
VERY DEEP MIXING TO AROUND 500-600 MB WEDNESDAY...WHICH LOOKS TO
SUPPORT WIND GUSTS TO/ABOVE 50 MPH BY MIDDAY ESPECIALLY ACROSS FAR
NORTHERN IL... WITH THE GRADIENT A BIT WEAKER TO THE SOUTH. DO
HAVE SOME CONCERNS THAT THE STRONGER GFS WINDS MAY BE A BIT
OVERDONE WITH BEST PRESSURE RISES TO OUR NORTH ACROSS WI...THOUGH
ENOUGH POTENTIAL EXISTS TO MAINTAIN OUR HIGH WIND WATCH ACROSS
COUNTIES GENERALLY NORTH OF I-80. HAVE ELECTED TO ISSUE A WIND
ADVISORY ACROSS THE SOUTHERN COUNTIES WHERE THERE IS MORE
CONFIDENCE THAT WINDS WILL REMAIN BELOW WARNING CRITERIA
(SUSTAINED 40 MPH /GUSTS 58 MPH). WITH GUSTY WINDS MODELS ARE
LIKELY TOO QUICK TO DECOUPLE WEDNESDAY EVENING...AND WILL LIKELY
SEE WINDY CONDITIONS CONTINUE INTO THE NIGHT.
WITH GOOD MIXING...HIGH TEMPS EXPECTED TO RANGE FROM MID 50S
NORTH TO LOW 60S SOUTH. LOWS EXPECTED IN THE MID-UPPER 40S
TONIGHT...MID TO UPPER 30S WEDNESDAY NIGHT.
RATZER
&&
.LONG TERM...
244 PM CDT
THURSDAY THROUGH TUESDAY...
THE EXTENDED FORECAST WILL BE CHARACTERIZED BY AN AMPLIFYING
UPPER FLOW PATTERN ACROSS MUCH OF THE COUNTRY WHICH WILL LEAD
TO A STEADY COOLING TREND INTO THE WEEKEND BEFORE REVERSING EARLY
NEXT WEEK. COLDEST DAY TIME TEMPS WILL BE SLIGHTLY BELOW NORMAL
SATURDAY WITH ABOVE NORMAL TEMPS EITHER SIDE OF THAT. THE UPPER
LOW OVER THE WESTERN GREAT LAKES WILL BREAK DOWN THURSDAY ALLOWING
THE SURFACE LOW WHICH WILL BE OVER NORTHERN WISCONSIN AND THE U.P.
OF MICHIGAN TO QUICKLY WEAKEN. THIS WILL LEAVE A BROAD UPPER
TROUGH ACROSS THE EASTERN TWO-THIRDS OF THE U.S. WEAK ENERGY WILL
MOVE DOWN THE WESTERN FLANK OF THE TROUGH WHILE A DEEPER UPPER LOW
PIVOTS SOUTHWARD ACROSS QUEBEC WHICH THEN RE-DEVELOPS ACROSS NEW
ENGLAND FRIDAY. THE DEVELOPING SURFACE LOW OVER NEW ENGLAND WILL
AID IN THE SHARPENING OF THE BAROCLINIC ZONE REMNANT FROM THE OLD
GREAT LAKES LOW THEN DRAW IT SOUTHWARD AS A COLD FRONT. THERE MAY
BE ENOUGH FORCING/MOISTURE TO GENERATE SOME SHOWERS AS THE FRONT
PASSES LATER THURSDAY OR THURSDAY EVENING. COLDER AIR WILL SPREAD
INTO THE REGION FOR FRIDAY. SHOULD SEE HIGHS IN THE MID TO UPPER
40S FRIDAY. THE UPPER TROUGH SHARPENS OVER THE REGION SATURDAY
WHICH WILL LEAD TO A CHANCE FOR PRECIPITATION STARTING EARLY
SATURDAY. A RAIN SNOW MIX COULD OCCUR EARLY BEFORE WARMING INTO
THE LOWER/MID 40S CHANGES ANYTHING TO RAIN INTO SATURDAY
AFTERNOON. THE SIGNAL IS NOT ALL THAT GREAT FOR PRECIP BUT ENOUGH
TO WARRANT LOW CHANCE POPS. THE UPPER TROUGH MEANDERS EAST INTO
EARLY SUNDAY AS SHARP RIDGING BUILDS ACROSS WESTERN NORTH AMERICA.
ANY LINGERING PRECIP WOULD LIKELY CHANGE TO LIGHT SNOW SATURDAY
NIGHT BEFORE ENDING.
THE AREA WILL BE UNDER NORTHEASTERLY UPPER FLOW AS THE TROUGH
DEPARTS TO THE EAST AND RIDGING CONTINUES WEST. THIS WILL BE
FAVORABLE FOR SOME WEAK WAVES TRAVERSING THE FLOW PERHAPS LEADING
TO MINIMAL POPS CHANCES MONDAY. THE RIDGING WILL SHARPEN THE
BAROCLINIC ZONE OVER THE AREA INTO TUESDAY WHICH MAY BRING ANOTHER
CHANCE AT PRECIP. MEDIUM RANGE GUIDANCE IS IN FAIR AGREEMENT ON A
DEEP UPPER TROUGH PUSHING INTO THE WESTERN U.S. MID NEXT WEEK AND
A SURFACE LOW LIFTING NORTHEAST BUT DETAILS DIFFER QUITE A BIT. A
TREND TOWARD MILDER CONDITIONS FOR AT LEAST A SHORT TIME DOES LOOK
FAVORED FOR MID WEEK.
MDB
&&
.FIRE WEATHER..
441 PM CDT
STRONG WEST-SOUTHWEST WINDS WILL BE IN PLACE OVER THE AREA ON
WEDNESDAY WITH SUSTAINED WINDS IN EXCESS OF 20 MPH AND GUSTS OF
50 TO 55 MPH. WITH SUN EXPECTED FOR AT LEAST SEVERAL HOURS...AND
POSSIBLY ALL DAY IN PLACES...MIXING MAY ALLOW FOR HUMIDITY TO DIP
TO AROUND 25 PERCENT. RAINFALL TONIGHT IN ADDITION TO EXISTING FUEL
MOISTURE VALUES IN EXCESS OF 15 PERCENT SHOULD PREVENT TRUE RED
FLAG CRITERIA...BUT BREEZY AND DRY WEATHER CONDITIONS WILL AT
LEAST BE NEAR THRESHOLDS...AND WITH THE DEEPER MIXING 10 HOUR FUEL
MOISTURE VALUES COULD NEAR 10 PERCENT IF AREAS...PARTICULARLY
SOUTH OF THE CHICAGO AREA...ESCAPE THUNDERSTORMS TONIGHT.
MTF/KMD
&&
.AVIATION...
FOR THE 18Z TAFS...
A STORM SYSTEM...CURRENTLY CENTERED OVER MISSOURI...WILL
STRENGTHEN RAPIDLY TONIGHT AS IT SHIFTS NORTH-NORTHEAST INTO
WISCONSIN BY DAYBREAK WEDNESDAY. THIS STORM SYSTEM WILL PRODUCE
SEVERAL WEATHER HAZARDS ACROSS THE AIRSPACE THROUGH THE FORECAST
PERIOD. THESE INCLUDE: CONTINUED LOW MVFR TO IFR CIGS...A PERIOD OF
THUNDERSTORMS...ESPECIALLY LATER THIS EVENING...ALONG WITH STRONG
GUSTY WEST-SOUTHWESTERLY WINDS ON WEDNESDAY.
CURRENTLY SATELLITE IMAGERY...ALONG WITH A PEEK OUT THE
WINDOW...INDICATES THAT THE CLOUD COVER ACROSS PORTIONS OF NORTHERN
ILLINOIS IS TRYING TO BREAK SOME. AS A RESULT...THERE LOOKS TO BE A
PERIOD OF IMPROVED CIGS AT TIMES THIS AFTERNOON. HOWEVER...WITH THE
SURFACE FRONT NOT EXPECTED TO LIFT NORTH OF THE AREA UNTIL LATER
THIS EVENING...IT IS LIKELY THAT CIGS AND VSBYS MAY AGAIN
DETERIORATE THIS EVENING. THIS WILL ALSO CONTINUE TO FAVOR
INCREASING EASTERLY WINDS THIS AFTERNOON AND EVENING.
AS FOR THE THUNDERSTORMS THREAT...THERE IS CURRENTLY A CLUSTER OF
SHOWERS AND STORMS IMPACTING NORTHWESTERN ILLINOIS. THESE STORMS
COULD IMPACT KRFD THROUGH EARLY AFTERNOON. HOWEVER...THE MAIN
THUNDERSTORM THREAT FOR ALL TAF SITES WILL BE THIS EVENING. THE
CURRENT TIMING OF LATE EVENING AFTER 03 UTC THIS EVENING STILL
APPEARS TO BE GOOD FOR THE EASTERN TAF SITES...AND AN HOUR OR TWO
SOONER AT KRFD. BRIEF PERIODS OF HEAVY RAIN AND HAIL WILL BE THE
PRIMARILY THREATS WITH THESE STORMS AS THE MOVE ACROSS THE TERMINALS.
THE WINDS WILL SHIFT OUT OF THE SOUTHWEST AROUND OR SHORTLY AFTER 07
UTC TONIGHT AS A SURFACE FRONTAL BOUNDARY LIFTS NORTHWARD OVER THE
AREA. CIGS WILL IMPROVE WITH THE PASSAGE OF THIS FRONT...BUT EXPECT
THESE SOUTHWEST WINDS TO BECOME GUSTY OVERNIGHT AND INTO WEDNESDAY.
DURING THE DAY WEDNESDAY WEST-SOUTHWEST WINDS ARE EXPECTED TO GUST
UP IN THE 45 TO 50 KT RANGE AT TIMES AS A STRONG AREA OF LOW
PRESSURE MOVES OVER THE U.P. OF MICHIGAN.
KJB
&&
.MARINE...
217 PM CDT
A STORM SYSTEM...CURRENTLY CENTERED OVER MISSOURI...WILL
STRENGTHEN RAPIDLY TONIGHT AS IT SHIFTS NORTH-NORTHEAST
INTO WISCONSIN BY DAYBREAK WEDNESDAY. THIS STORM SYSTEM WILL
PRODUCE A PERIOD OF STRONG EASTERLY WINDS (35 KT GALES)
LATE TONIGHT...FOLLOWED BY A PERIOD OF STRONG GALE FORCE WEST-
SOUTHWESTERLY WINDS ON WEDNESDAY. STORM FORCE GUSTS WILL ALSO
BE POSSIBLE ALONG THE WESTERN SHORES OF THE LAKE ON WEDNESDAY.
THESE WESTERLY WINDS WILL CONTINUE WEDNESDAY NIGHT INTO
THURSDAY...THOUGH WIND SPEEDS SHOULD GRADUALLY BE ON THE DOWNWARD
TREND. LATER IN THE WEEK EXPECT A COLD FRONT TO DROP SOUTH DOWN
THE LAKE...WITH A PERIOD OF GUSTY NORTHERLY WINDS EXPECTED.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WIND ADVISORY...ILZ019-ILZ021-ILZ023-ILZ032-ILZ033-ILZ039...7 AM
WEDNESDAY TO 8 PM WEDNESDAY.
HIGH WIND WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ020-ILZ022...7 AM WEDNESDAY
TO 8 PM WEDNESDAY.
IN...HIGH WIND WATCH...INZ001-INZ002...7 AM WEDNESDAY TO 8 PM
WEDNESDAY.
WIND ADVISORY...INZ010-INZ011-INZ019...7 AM WEDNESDAY TO 8 PM
WEDNESDAY.
LM...GALE WARNING...LMZ740-LMZ741...1 AM WEDNESDAY TO 10 AM WEDNESDAY.
SMALL CRAFT ADVISORY...LMZ740-LMZ741...7 PM TUESDAY TO 1 AM
WEDNESDAY.
STORM WATCH...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745...10 AM
WEDNESDAY TO 7 PM WEDNESDAY.
GALE WARNING...LMZ742-LMZ743-LMZ744-LMZ745...4 AM WEDNESDAY TO
10 AM WEDNESDAY.
SMALL CRAFT ADVISORY...LMZ742-LMZ743-LMZ744-LMZ745...7 PM
TUESDAY TO 4 AM WEDNESDAY.
DENSE FOG ADVISORY...LMZ777-LMZ779 UNTIL 10 PM TUESDAY.
GALE WARNING...LMZ777-LMZ779...1 AM WEDNESDAY TO 1 AM THURSDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
321 PM CDT TUE MAR 15 2016
.SHORT TERM...
320 PM CDT
TONIGHT THROUGH WEDNESDAY NIGHT...
PRIMARY FORECAST FOCUS IS WITH SEVERE WEATHER POTENTIAL THROUGH
THIS EVENING...AND VERY WINDY CONDITIONS DEVELOPING LATER TONIGHT
AND CONTINUING THROUGH WEDNESDAY NIGHT.
SFC LOW PRESSURE WAS DEEPENING ACROSS NORTHEASTERN MISSOURI EARLY
THIS AFTERNOON...IN RESPONSE TO A VIGOROUS MID-LEVEL SHORT WAVE
PROPAGATING ACROSS EASTERN KANSAS AND INTO THE MID-MISSOURI RIVER
VALLEY PER GOES WATER VAPOR IMAGERY. SOUTH-SOUTHEAST LOW LEVEL
RETURN FLOW PRODUCING IMPRESSIVE WARM SECTOR AIR MASS FOR MID-
MARCH... CHARACTERIZED BY AIR TEMPS IN THE LOW-MID 70S AND SURFACE
DEW POINTS OF 55-60 INTO CENTRAL IL/WEST CENTRAL IN INCLUDING
SOUTHERN COUNTIES OF THE WFO LOT CWA. WHILE SURFACE FLOW IS BACKED
TO THE SOUTHEAST ACROSS THE AREA...THE EFFECTIVE SURFACE WARM
FRONT APPEARS TO BE APPROXIMATELY NEAR A GALESBURG-PONTIAC-
LAFAYETTE LINE. CONSIDERABLE SUNSHINE WAS HELPING TO DESTABILIZE
THE AIR MASS ACROSS THE MISSISSIPPI VALLEY AND CENTRAL IL...WITH
SPC RAP ANALYSIS INDICATING MLCAPES INCREASING TO 1000-1500 J/KG
WITH CIN WEAKENING TO 100 J/KG OR LESS. DYNAMICS ARE BECOMING MORE
FAVORABLE FOR SEVERE CONVECTION AS WELL WITH APPROACH OF STRONG
MID-LEVEL WAVE...WITH 60 KT EFFECTIVE DEEP LAYER BULK SHEAR AND
0-3 KM STORM RELATIVE HELICITY OF 200-300 M2S2 IN THE VICINITY OF
THE WARM FRONTAL BOUNDARY. VISIBLE SATELLITE DEPICTS INCREASING CU
FIELD ALONG THE MISSISSIPPI RIVER AND INTO NORTHEAST
MISSOURI...WHERE STORM INITIATION IS EXPECTED OVER THE NEXT FEW
HOURS AND HAS BEEN INDICATED BY HIGH-RES GUIDANCE. ENVIRONMENT
PRIMED FOR SUPERCELL DEVELOPMENT...AND RECENT SPC MCD INDICATES
TORNADO WATCH LIKELY IN THE NEXT FEW HOURS WITHIN THE ENHANCED
RISK AREA TO OUR WEST/SOUTHWEST. BASED ON HIGH RES
GUIDANCE...EVOLUTION STILL APPEARS TO BE INITIATION 22-23Z TO OUR
WEST AND SOUTHWEST... WITH STORMS THEN SPREADING NORTHEAST INTO
THE FORECAST AREA AFTER 7-8 PM. LARGE HAIL...DAMAGING WIND AND
ISOLATED TORNADO THREAT WILL EXIST WITH SUPERCELLAR STORMS MOVING
INTO THE CWA INITIALLY WITH OUR IL COUNTIES ALONG/SOUTH OF I-80
LIKELY UNDER THE HIGHEST RISK. WIND AND TORNADO THREAT...WHILE NOT
ZERO...WILL LIKELY DIMINISH FURTHER NORTHEAST INTO THE CHICAGO
METRO WITH SOME DECREASE IN INTENSITY OF STORMS POSSIBLE WITH
GRADUAL DIURNAL DECREASE IN INSTABILITY. THE POTENTIAL FOR SEVERE
WEATHER WILL EXIST HOWEVER ALL THE WAY TO LAKE MICHIGAN AND OUR
EASTERN CWA COUNTIES AND STORMS ARRIVE IN THE 9-10 PM TIME FRAME
AND LAST THROUGH ABOUT MIDNIGHT OR 1 AM AS THE SURFACE LOW LIFTS
NORTHEAST INTO WISCONSIN AND ITS STRONG TRAILING COLD FRONT PUSHES
THROUGH THE AREA. SCATTERED SHOWERS OR EVEN ISOLATED THUNDERSTORMS
WILL LIKELY LINGER OVER PARTS OF NORTH CENTRAL ILLINOIS AND THE
IL/WI BORDER REGION AS THE UPPER TROUGH LIFTS ACROSS THE AREA
OVERNIGHT. SOME POTENTIAL FOR A FEW HIGH-BASED INSTABILITY SHOWERS
WEDNESDAY AFTERNOON NEAR THE WISCONSIN BORDER WITH DEEP ADIABATIC
LAPSE RATES.
WINDS WILL VEER FROM THE SOUTHEAST TO THE WEST-SOUTHWEST BEHIND
THE FRONT OVERNIGHT...INCREASING IN SPEED AND BECOMING GUSTY TO
40-45 MPH BY MORNING. MODEL FORECAST SOUNDINGS CONTINUE TO DEPICT
VERY DEEP MIXING TO AROUND 500-600 MB WEDNESDAY...WHICH LOOKS TO
SUPPORT WIND GUSTS TO/ABOVE 50 MPH BY MIDDAY ESPECIALLY ACROSS FAR
NORTHERN IL... WITH THE GRADIENT A BIT WEAKER TO THE SOUTH. DO
HAVE SOME CONCERNS THAT THE STRONGER GFS WINDS MAY BE A BIT
OVERDONE WITH BEST PRESSURE RISES TO OUR NORTH ACROSS WI...THOUGH
ENOUGH POTENTIAL EXISTS TO MAINTAIN OUR HIGH WIND WATCH ACROSS
COUNTIES GENERALLY NORTH OF I-80. HAVE ELECTED TO ISSUE A WIND
ADVISORY ACROSS THE SOUTHERN COUNTIES WHERE THERE IS MORE
CONFIDENCE THAT WINDS WILL REMAIN BELOW WARNING CRITERIA
(SUSTAINED 40 MPH /GUSTS 58 MPH). WITH GUSTY WINDS MODELS ARE
LIKELY TOO QUICK TO DECOUPLE WEDNESDAY EVENING...AND WILL LIKELY
SEE WINDY CONDITIONS CONTINUE INTO THE NIGHT.
WITH GOOD MIXING...HIGH TEMPS EXPECTED TO RANGE FROM MID 50S
NORTH TO LOW 60S SOUTH. LOWS EXPECTED IN THE MID-UPPER 40S
TONIGHT...MID TO UPPER 30S WEDNESDAY NIGHT.
RATZER
&&
.LONG TERM...
244 PM CDT
THURSDAY THROUGH TUESDAY...
THE EXTENDED FORECAST WILL BE CHARACTERIZED BY AN AMPLIFYING
UPPER FLOW PATTERN ACROSS MUCH OF THE COUNTRY WHICH WILL LEAD
TO A STEADY COOLING TREND INTO THE WEEKEND BEFORE REVERSING EARLY
NEXT WEEK. COLDEST DAY TIME TEMPS WILL BE SLIGHTLY BELOW NORMAL
SATURDAY WITH ABOVE NORMAL TEMPS EITHER SIDE OF THAT. THE UPPER
LOW OVER THE WESTERN GREAT LAKES WILL BREAK DOWN THURSDAY ALLOWING
THE SURFACE LOW WHICH WILL BE OVER NORTHERN WISCONSIN AND THE U.P.
OF MICHIGAN TO QUICKLY WEAKEN. THIS WILL LEAVE A BROAD UPPER
TROUGH ACROSS THE EASTERN TWO-THIRDS OF THE U.S. WEAK ENERGY WILL
MOVE DOWN THE WESTERN FLANK OF THE TROUGH WHILE A DEEPER UPPER LOW
PIVOTS SOUTHWARD ACROSS QUEBEC WHICH THEN RE-DEVELOPS ACROSS NEW
ENGLAND FRIDAY. THE DEVELOPING SURFACE LOW OVER NEW ENGLAND WILL
AID IN THE SHARPENING OF THE BAROCLINIC ZONE REMNANT FROM THE OLD
GREAT LAKES LOW THEN DRAW IT SOUTHWARD AS A COLD FRONT. THERE MAY
BE ENOUGH FORCING/MOISTURE TO GENERATE SOME SHOWERS AS THE FRONT
PASSES LATER THURSDAY OR THURSDAY EVENING. COLDER AIR WILL SPREAD
INTO THE REGION FOR FRIDAY. SHOULD SEE HIGHS IN THE MID TO UPPER
40S FRIDAY. THE UPPER TROUGH SHARPENS OVER THE REGION SATURDAY
WHICH WILL LEAD TO A CHANCE FOR PRECIPITATION STARTING EARLY
SATURDAY. A RAIN SNOW MIX COULD OCCUR EARLY BEFORE WARMING INTO
THE LOWER/MID 40S CHANGES ANYTHING TO RAIN INTO SATURDAY
AFTERNOON. THE SIGNAL IS NOT ALL THAT GREAT FOR PRECIP BUT ENOUGH
TO WARRANT LOW CHANCE POPS. THE UPPER TROUGH MEANDERS EAST INTO
EARLY SUNDAY AS SHARP RIDGING BUILDS ACROSS WESTERN NORTH AMERICA.
ANY LINGERING PRECIP WOULD LIKELY CHANGE TO LIGHT SNOW SATURDAY
NIGHT BEFORE ENDING.
THE AREA WILL BE UNDER NORTHEASTERLY UPPER FLOW AS THE TROUGH
DEPARTS TO THE EAST AND RIDGING CONTINUES WEST. THIS WILL BE
FAVORABLE FOR SOME WEAK WAVES TRAVERSING THE FLOW PERHAPS LEADING
TO MINIMAL POPS CHANCES MONDAY. THE RIDGING WILL SHARPEN THE
BAROCLINIC ZONE OVER THE AREA INTO TUESDAY WHICH MAY BRING ANOTHER
CHANCE AT PRECIP. MEDIUM RANGE GUIDANCE IS IN FAIR AGREEMENT ON A
DEEP UPPER TROUGH PUSHING INTO THE WESTERN U.S. MID NEXT WEEK AND
A SURFACE LOW LIFTING NORTHEAST BUT DETAILS DIFFER QUITE A BIT. A
TREND TOWARD MILDER CONDITIONS FOR AT LEAST A SHORT TIME DOES LOOK
FAVORED FOR MID WEEK.
MDB
&&
.FIRE WEATHER...
441 AM CDT
STRONG WEST-SOUTHWEST WINDS WILL BE IN PLACE OVER THE AREA ON
WEDNESDAY WITH SUSTAINED WINDS WILL IN EXCESS OF 20 MPH AND GUSTS
OF 50 MPH IF NOT SPORADICALLY HIGHER. WITH SUN EXPECTED FOR AT
LEAST SEVERAL HOURS...AND POSSIBLY ALL DAY IN PLACES...MIXING MAY
ALLOW FOR HUMIDITY TO DIP TO AROUND 25 PERCENT. FUEL MOISTURE
VALUES IN EXCESS OF 15 PERCENT SHOULD PREVENT TRUE RED FLAG
CRITERIA...BUT BREEZY AND DRY WEATHER CONDITIONS WILL AT LEAST BE
NEAR THRESHOLDS.
MTF
&&
.AVIATION...
FOR THE 18Z TAFS...
A STORM SYSTEM...CURRENTLY CENTERED OVER MISSOURI...WILL
STRENGTHEN RAPIDLY TONIGHT AS IT SHIFTS NORTH-NORTHEAST INTO
WISCONSIN BY DAYBREAK WEDNESDAY. THIS STORM SYSTEM WILL PRODUCE
SEVERAL WEATHER HAZARDS ACROSS THE AIRSPACE THROUGH THE FORECAST
PERIOD. THESE INCLUDE: CONTINUED LOW MVFR TO IFR CIGS...A PERIOD OF
THUNDERSTORMS...ESPECIALLY LATER THIS EVENING...ALONG WITH STRONG
GUSTY WEST-SOUTHWESTERLY WINDS ON WEDNESDAY.
CURRENTLY SATELLITE IMAGERY...ALONG WITH A PEEK OUT THE
WINDOW...INDICATES THAT THE CLOUD COVER ACROSS PORTIONS OF NORTHERN
ILLINOIS IS TRYING TO BREAK SOME. AS A RESULT...THERE LOOKS TO BE A
PERIOD OF IMPROVED CIGS AT TIMES THIS AFTERNOON. HOWEVER...WITH THE
SURFACE FRONT NOT EXPECTED TO LIFT NORTH OF THE AREA UNTIL LATER
THIS EVENING...IT IS LIKELY THAT CIGS AND VSBYS MAY AGAIN
DETERIORATE THIS EVENING. THIS WILL ALSO CONTINUE TO FAVOR
INCREASING EASTERLY WINDS THIS AFTERNOON AND EVENING.
AS FOR THE THUNDERSTORMS THREAT...THERE IS CURRENTLY A CLUSTER OF
SHOWERS AND STORMS IMPACTING NORTHWESTERN ILLINOIS. THESE STORMS
COULD IMPACT KRFD THROUGH EARLY AFTERNOON. HOWEVER...THE MAIN
THUNDERSTORM THREAT FOR ALL TAF SITES WILL BE THIS EVENING. THE
CURRENT TIMING OF LATE EVENING AFTER 03 UTC THIS EVENING STILL
APPEARS TO BE GOOD FOR THE EASTERN TAF SITES...AND AN HOUR OR TWO
SOONER AT KRFD. BRIEF PERIODS OF HEAVY RAIN AND HAIL WILL BE THE
PRIMARILY THREATS WITH THESE STORMS AS THE MOVE ACROSS THE TERMINALS.
THE WINDS WILL SHIFT OUT OF THE SOUTHWEST AROUND OR SHORTLY AFTER 07
UTC TONIGHT AS A SURFACE FRONTAL BOUNDARY LIFTS NORTHWARD OVER THE
AREA. CIGS WILL IMPROVE WITH THE PASSAGE OF THIS FRONT...BUT EXPECT
THESE SOUTHWEST WINDS TO BECOME GUSTY OVERNIGHT AND INTO WEDNESDAY.
DURING THE DAY WEDNESDAY WEST-SOUTHWEST WINDS ARE EXPECTED TO GUST
UP IN THE 45 TO 50 KT RANGE AT TIMES AS A STRONG AREA OF LOW
PRESSURE MOVES OVER THE U.P. OF MICHIGAN.
KJB
&&
.MARINE...
217 PM CDT
A STORM SYSTEM...CURRENTLY CENTERED OVER MISSOURI...WILL
STRENGTHEN RAPIDLY TONIGHT AS IT SHIFTS NORTH-NORTHEAST
INTO WISCONSIN BY DAYBREAK WEDNESDAY. THIS STORM SYSTEM WILL
PRODUCE A PERIOD OF STRONG EASTERLY WINDS (35 KT GALES)
LATE TONIGHT...FOLLOWED BY A PERIOD OF STRONG GALE FORCE WEST-
SOUTHWESTERLY WINDS ON WEDNESDAY. STORM FORCE GUSTS WILL ALSO
BE POSSIBLE ALONG THE WESTERN SHORES OF THE LAKE ON WEDNESDAY.
THESE WESTERLY WINDS WILL CONTINUE WEDNESDAY NIGHT INTO
THURSDAY...THOUGH WIND SPEEDS SHOULD GRADUALLY BE ON THE DOWNWARD
TREND. LATER IN THE WEEK EXPECT A COLD FRONT TO DROP SOUTH DOWN
THE LAKE...WITH A PERIOD OF GUSTY NORTHERLY WINDS EXPECTED.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WIND ADVISORY...ILZ019-ILZ021-ILZ023-ILZ032-ILZ033-ILZ039...7 AM
WEDNESDAY TO 8 PM WEDNESDAY.
HIGH WIND WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ020-ILZ022...7 AM WEDNESDAY
TO 8 PM WEDNESDAY.
IN...HIGH WIND WATCH...INZ001-INZ002...7 AM WEDNESDAY TO 8 PM
WEDNESDAY.
WIND ADVISORY...INZ010-INZ011-INZ019...7 AM WEDNESDAY TO 8 PM
WEDNESDAY.
LM...GALE WARNING...LMZ740-LMZ741...1 AM WEDNESDAY TO 10 AM WEDNESDAY.
SMALL CRAFT ADVISORY...LMZ740-LMZ741...7 PM TUESDAY TO 1 AM
WEDNESDAY.
STORM WATCH...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745...10 AM
WEDNESDAY TO 7 PM WEDNESDAY.
GALE WARNING...LMZ742-LMZ743-LMZ744-LMZ745...4 AM WEDNESDAY TO
10 AM WEDNESDAY.
SMALL CRAFT ADVISORY...LMZ742-LMZ743-LMZ744-LMZ745...7 PM
TUESDAY TO 4 AM WEDNESDAY.
DENSE FOG ADVISORY...LMZ777-LMZ779 UNTIL 10 PM TUESDAY.
GALE WARNING...LMZ777-LMZ779...1 AM WEDNESDAY TO 1 AM THURSDAY.
&&
$$
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AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
314 PM CDT TUE MAR 15 2016
.SHORT TERM...(Tonight)
ISSUED AT 312 PM CDT TUE MAR 15 2016
19z/2pm surface analysis shows a 997mb low over northeast Missouri,
with a warm front extending E/SE across south-central Illinois.
Despite the presence of this forcing, convection has not yet
materialized across Missouri or Illinois as the atmosphere remains
capped. The short-wave trough that will eventually approach from
the west and break the cap is still well to the west across western
Kansas/Nebraska, so think cap will hold firm through the remainder
of the afternoon. HRRR has been consistently showing scattered
thunderstorms developing along the trailing cold front across
eastern Missouri after 21z/4pm...with the activity then tracking
E/NE into central Illinois this evening. 4km WRF-NMM has similar
timing, and both high-res models suggest the storms will quickly
shift out of the KILX CWA by midnight. Given strong directional low-
level wind shear in the vicinity of the warm front, the main mode of
any convection that develops later today will be supercellular. As
such, damaging wind gusts and large hail remain the primary
threats...although a few tornadoes will also be possible mainly
along and northwest of the I-55 corridor. Have therefore included
likely PoPs and mentioned severe weather across the western half of
the CWA this evening accordingly. Any convection that fires will
rapidly push eastward out of the area by midnight, with only a few
lingering rain showers across the NW from the Peoria area northward
after midnight. Once the storms pass, strong/gusty southwesterly
winds will develop, with forecast soundings and numeric guidance
suggesting gusts of 30-35 mph. Overnight lows will drop into the
middle to upper 40s.
&&
.LONG TERM...(Wednesday through Tuesday)
ISSUED AT 312 PM CDT TUE MAR 15 2016
Deepening surface low pressure forecast to push into central
Wisconsin by 12z Wednesday with a tight pressure gradient over most
of the forecast area during the day. Forecast soundings showing 40-
45 kts just off the surface tomorrow mid morning through the
afternoon hours so wind gusts of 35 to 45 mph look likely over
most of the area, except south of the Interstate 70 corridor. As
a result, a wind advisory will be issued for a good portion of
the forecast area for tomorrow. Areas north of I-74 will get close
to some warning criteria winds, especially if the wrap around
moisture/clouds stay to our north like most of the models suggest.
Despite the passage of the cold front this evening, temperatures
will be mild again on Wednesday, although not as warm as today.
Look for highs to climb into the 60s most areas.
The strong surface low will begin to fill across the lower Great
Lakes on Thursday as upper level energy is transferred over to the
East Coast. This will result in an elongated surface trof from the
new low off New England west through the southern Great Lakes.
This feature will gradually slide south bringing a more extensive
cloud band south with it and the threat for some light precip
starting on Friday night and continuing on and off into Saturday
night. We may see a mix of rain and snow across our north Friday
night into early Saturday morning, and possibly again late
Saturday night into Sunday. No accumulations are expected with any
snow that does occur across our north.
The upper trof will gradually work its way southeast across the
Great Lakes on Sunday and Monday with rather cool temperatures
prevailing, at least compared to what we have had over the past
couple of days. However, with the trof being more progressive, the
cool down will not last long as most medium range models suggest
the trof will shift off to our east by early next week with more
of a zonal flow developing over the Midwest resulting in a gradual
moderating trend through the middle of next week.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
ISSUED AT 1243 PM CDT TUE MAR 15 2016
Main aviation forecast concern continues to be potential
convection this evening. Latest model runs are in fairly good
agreement with timing of storms, although the HRRR remains
slightly faster than the 4km NAM and 4km WRF-NMM. Taking a
consensus of solutions, have included a TEMPO group for thunder
and MVFR ceilings at KPIA/KSPI between 00z and 02z...then further
east to KBMI/KDEC between 01z and 03z. Given uncertainties in
areal coverage further east, have only mentioned VCTS at KCMI
after 02z. Once the storms pass, NAM forecast soundings suggest a
period of MVFR ceilings before skies clear overnight into
Wednesday morning. Winds will initially be from the southeast with
gusts to around 25kt this afternoon, then will veer to the
southwest after frontal passage this evening. As the pressure
gradient tightens, very strong W/SW winds gusting to between 30
and 35kt will be likely on Wednesday.
&&
.ILX Watches/Warnings/Advisories...
Wind Advisory from 7 AM to 8 PM CDT Wednesday for ILZ027>031-
036>038-040>057-061>063.
&&
$$
SHORT TERM...Barnes
LONG TERM...Smith
AVIATION...Barnes
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1243 PM CDT TUE MAR 15 2016
.UPDATE...
ISSUED AT 953 AM CDT TUE MAR 15 2016
Latest models continue to delay the onset of strong to severe
convection later today. 12z NAM tracks 998mb low currently south
of Kansas City into southeast Iowa by 00z. Forecast soundings show
the airmass ahead of the system will remain strongly capped
through the afternoon, suppressing any storm development within
the warm sector. As a short-wave trough evident on 14z/9am water
vapor imagery over eastern Colorado approaches from the west, the
cap will gradually erode toward evening. At that time, scattered
thunderstorms will develop along an advancing cold front. While
the NAM shows little or no convection along the front, higher-res
models such as the HRRR show scattered storms forming across
northern Missouri by late afternoon, then tracking northeastward
across the northern half of the KILX CWA this evening. Damaging
winds and large hail remain the primary threats...although a few
tornadoes will be possible near the low track primarily northwest
of the I-55 corridor. Have updated the forecast this morning to
remove PoPs everywhere except the far north where a small cluster
of storms has been moving across Knox, northern Peoria, and Stark
counties. Have also gone largely dry through the afternoon, with
low chance PoPs arriving after 22z along/west of the Illinois
River. Also reduced sky cover to go with a partly to mostly sunny
forecast with afternoon highs in the lower to middle 70s.
&&
.SHORT TERM...(Today)
ISSUED AT 345 AM CDT TUE MAR 15 2016
A 997 mb surface low over south central KS early this morning
will deepen as a shortwave over the central Rockies tracks
eastward into the Plains. The low looks to move into west central
IL by evening...although some track differences are noted in model
guidance by this time. A warm front will likely extend from
southeast Iowa into Central Illinois...roughly along the I-74
corridor. Sfc-6 km bulk shear should easily exceed 50 kts while
models suggest 1500-2500 J/KG MUCAPE develops across central IL.
Especially in the vicinity of the warm front and toward the
surface low pressure...this could bring a threat for rotating
storms and a slight tornado threat in the late afternoon and
evening. In addition...steep mid-level lapse rates will bring a
threat of large hail and damaging winds. Models have slowed down
somewhat in sweeping a cold front across central IL mainly 00z to
06z this evening now...bringing this best chance for a coherent
line of thunderstorms. SPC has central Illinois from around I-70
northward outlooked for a slight risk of severe thunderstorms as a
result. A slight chance of thunderstorms will move into areas west
of the Illinois River by daybreak as a cluster of storms currently
over NW Missouri/SW Iowa moves eastward. This disturbance will
continue northeastward into northern Illinois by
afternoon...bringing slight chances for thunderstorms about as far
southward by noon. A bit of a lull toward afternoon as the cold
frontal band approaches again for the late afternoon...spreading a
chance for thunderstorms throughout much of central Illinois north
of I-70 by evening.
Also in the short term...an area of dense fog has formed in clear
skies and light winds from near Paris to just east of Peoria...and
have issued a dense fog advisory until 9 a.m. To the west...high
cloud cover and strengthening southeast winds have limited
development of fog...and to the northeast a bank of stratus has
limited radiational cooling needed to produce dense fog.
Warm highs today should reach the low to mid 70s as warm moist
air advects in from the south ahead of the approaching low center.
Winds in the morning expected to be around 5-15 mph from the
southeast...increasing to 15-20 mph by afternoon with gusts to the
25-30 mph range.
.LONG TERM...(Tonight through Monday)
ISSUED AT 345 AM CDT TUE MAR 15 2016
00Z forecast models continue slower trend with deepening surface low
pressure ejecting ne from eastern KS into west central IL by 00Z/7
pm today and into WI by 12Z/7 am Wed and deepening to 985 mb or
stronger by then. A warm front to be near I-74 late this afternoon
and evening, while a sharp cold front accelerates eastward across IL
this during this evening with scattered to broken line of convection
expected ahead of front. SPC day1 outlook has shifted slight risk of
severe storms nw of I-70 where 15% risk of damaging wind gusts and
large hail and 2-5% risk of tornadoes, with the 5% risk from I-55
nw. Convection to develop over ne MO/se IA and west central IL late
this afternoon and track eastward across central and eastern IL
during the evening. Most of this convection should be east of
central IL overnight with isolated showers along and north of a
Rushville to Bloomington line after midnight. Models have increased
wind speeds overnight and Wed and northern areas may be reaching
wind advisory criteria with sustained winds 30 mph and wind gusts 40-
45 mph. A High wind watch has been posted over northern IL overnight
and Wed where even higher winds expected.
Strong cutoff 500 mb low deepening to 525-530 dm as it lifts ne
across WI and into upper MI during Wed along with associated strong
surface low pressure near this upper level low to give the strong
WSW winds over IL overnight and Wed. Shower chances to stay north of
central IL Wed and Thu closer to strong low pressure system hanging
around the western Great Lakes region. Mostly sunny skies
expectedWed. Temperatures about 10 degrees cooler on Wed than today,
but still a good 10 degrees above normal for mid March. Highs Wed
mostly in the lower 60s, ranging from near 60F nw of IL river to mid
60s se of I-70. Lows Wed night in the upper 30s north of I-72 and
lower 40s south of I-72. A weak short elongated short wave to track
east across the mid MS river valley Wed night and bring slight
chances of light rain showers to areas se of I-70 in southeast IL.
Still windy on Thu with west winds 20-25 mph and gusts of 25-35 mph
with partly to mostly sunny skies, more clouds from I-74 north.
Temps cool a bit more on Thu with highs ranging from lower 50s from
Peoria and Bloomington north to near 60F south of I-70.
Strong upper level low shifts east across the Great Lakes Thu night
while weak upper level ridge into IL on Friday keeps it dry with
lighter WNW winds diminishing to 8-15 mph. Highs Friday upper 40s
northern CWA and lower 50s southern half of CWA which is starting
to get a bit below normal for our area.
Extended forecast models continue to dig a deep upper level trof se
across the Midwest Fri night and Saturday and into the OH/TN river
valleys on Sunday. Stronger surface low pressure and heavier qpf in
over the southeast states, with lighter qpf over IL Fri night into
Sat evening. Some light qpf could still linger over eastern IL
Sunday. Temperature profiles support a chance of light snow with
ligth rain overnight Friday night and Sat morning and again Sat
night and Sunday morning if it lingers that long. Temps to be a bit
cooler than normal this weekend with highs in the mid to upper 40s
Sat/Sun and lows near freezing Sat and Sun nights.
Upper level trof shifts away from IL on Sunday night and Monday
while upper level ridge to shift east across the plains toward the
MS river valley by next Tuesday and brings dry weather with temps
starting to moderate into the lower 50s Monday and 55-60F next Tue.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
ISSUED AT 1243 PM CDT TUE MAR 15 2016
Main aviation forecast concern continues to be potential
convection this evening. Latest model runs are in fairly good
agreement with timing of storms, although the HRRR remains
slightly faster than the 4km NAM and 4km WRF-NMM. Taking a
consensus of solutions, have included a TEMPO group for thunder
and MVFR ceilings at KPIA/KSPI between 00z and 02z...then further
east to KBMI/KDEC between 01z and 03z. Given uncertainties in
areal coverage further east, have only mentioned VCTS at KCMI
after 02z. Once the storms pass, NAM forecast soundings suggest a
period of MVFR ceilings before skies clear overnight into
Wednesday morning. Winds will initially be from the southeast with
gusts to around 25kt this afternoon, then will veer to the
southwest after frontal passage this evening. As the pressure
gradient tightens, very strong W/SW winds gusting to between 30
and 35kt will be likely on Wednesday.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...Barnes
SHORT TERM...Onton
LONG TERM...07
AVIATION...Barnes
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
549 PM EDT TUE MAR 15 2016
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 427 PM EDT TUE MAR 15 2016
WV IMAGERY AND RAP ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM
ALBERTA/SASK INTO THE WRN PLAINS WITH WEAK DOWNSTREAM RIDGING OVER
THE CENTRAL AND EASTERN GREAT LAKES INTO NW ONTARIO. AT THE SFC...SE
FLOW WAS INCREASING OVER NRN WI BETWEEN A RIDGE OVER THE CENTRAL AND
ERN LAKES AND A TROUGH FROM SRN MANITOBA THROUGH MN TO LOW PRES OVER
MO. A LINE SHRA EXTENDING FROM NW WI INTO SE WI/NE IL WERE SUPPORTED
BY STRONG LOW LEVEL MOISTURE INFLOW AND ISENTROPIC LIFT NOTED ON 290-
295K SFCS AHEAD OF THE TROUGH. THE INCREASING ISENTROPIC ASCENT AND
MID-LVL Q-VECT CONV AHEAD OF THE NEGATIVE-TILT TROUGH HAS RESULTED
IN CLOUDY SKIES ACROSS MUCH OF THE FCST AREA EXCEPT FOR FAR EAST
WHERE DRY EASTERLY FLOW AND PROXIMITY TO RIDGE HAS KEPT SKIES PARTLY
SUNNY. HIGH TEMPS TODAY HAVE RANGED FROM MID 50S FAR WEST AND EAST
TO THE LOWER 40S NEAR LAKE MI SHORE IN SE FLOW.
TONIGHT...AS THE NEG-TILT SHORTWAVE TROUGH OVER THE CENTRAL PLAINS
LIFTS TOWARD THE WRN GREAT LAKES THE SFC LOW IS EXPECTED TO DEEPEN
TO NEAR 987 MB OVER SRN WI BY 12Z WED. THE NAM AND GFS CONTINUE TO
TREND SLOWER WITH THE ARRIVAL OF THE PCPN BAND MOVING THROUGH WI SO
HAVE BACKED OFF ON INCREASING POPS TO LIKELY/CATEGORICAL OVER WEST
UNTIL LATE EVENING AND OVER THE CENTRAL COUNTIES UNTIL LATE TONIGHT
WHEN COMBINATION OF INCREASED UPPER DIVERGENCE IN COUPLED UPPER JET
STRUCTURE AND STRONG DEEP LAYER Q-VECT CONVERGENCE AHEAD OF
SHORTWAVE BEGINS TO OVERCOME DRY EASTERLY FLOW. THERMAL PROFILES AND
FCST SOUNDINGS SUGGEST THAT WITH THE WAA SURGE...THE PCPN BAND
COMING IN INITIALLY WILL REMAIN MOSTLY RAIN TONIGHT. ERLY WINDS WILL
ALSO BECOME GUSTY LATE TONIGHT...ESPECIALLY OVER THE KEWEENAW AND
NEAR LAKE MI WHERE GUSTS OVER 35 MPH ARE EXPECTED. ALSO KEPT IN
SLIGHT CHC OF THUNDER OVER SCNTRL UPPER LATE TONIGHT INTO EARLY WED
MORNING AS MODELS STILL SHOW NEG SHOWALTER INDICES AND MUCAPE OF A
FEW HUNDRED J/KG ON NOSE OF 85H THETA-E AND STRONG ISENTROPIC ASCENT.
WEDNESDAY...RAIN WILL BE FALLING HEAVILY IN THE MORNING SO PRECIP
LOADING COULD ALSO AID IN BRINGING STRONG/GUSTY WINDS TO SFC. AT THE
LEAST...DUE TO INCREASING PRESSURE GRADIENT TO NORTH OF DEEPENING
SFC LOW OVER WI DOWN TO LESS THAN 990MB BY 12Z WED...AREAS FAVORED
BY EAST WINDS SUCH AS LK MICHIGAN/BAY OF GREEN BAY AND ACROSS
KEWEENAW COULD SEE EAST WINDS GUSTING TO 30-40 MPH MUCH OF THE DAY.
AS DRY SLOT WITH SYSTEM AND Q-VECT DIV MOVES ACROSS CENTRAL AND ERN
AREAS EXPECT PRECIP TO DIMINISH THERE. EXCEPTION WILL BE OVER
WESTERN CWA WHERE DEEP LAYER Q-VECTOR CONVERGENCE EXPANDS ON NW SIDE
OF DEEPENING UPPER LOW AND STRONG SFC-H85 LOW MEANDERING OVER
NORTHERN LAKE MI AND DEFORMATION FORCING ALLOWS BAND TO SET UP OVER
THE WEST.
THE OTHER TRICKY PART OF THIS FCST WILL BE PTYPE AND POSSIBILITY OF
ACCUMULATING SNOW ON WED. MODEL SOUNDINGS...ESPECIALLY NAM...SUGGEST
POTENTIAL FOR DYNAMIC COOLING WITH HEAVIER PCPN BAND MOVING THROUGH
WED MORNING WITH A CHANGEOVER TO SNOW SHORTLY AFT 12Z. IF THIS
HAPPENS AS QUICKLY AS NAM INDICATES THERE COULD BE A POTENTIAL OF
SEVERAL INCHES OF WET SNOW WED MORNING OVER THE HIGHER TERRAIN AREAS
OF THE WEST HALF OF UPPER MI AS THIS HEAVIER BAND MOVES THROUGH THE
AREA. RIGHT NOW...SINCE THERE IS STILL SOME MODEL UNCERTAINTY WITH
THERMAL FIELDS/PROFILES HAVE ELECTED TO ONLY PUT IN A COUPLE INCHES
OF SNOW OVER MAINLY THE KEWEENAW AND WRN MQT/ERN BARAGA COUNTIES WED
MORNING BEFORE PCPN TAPERS OFF SOME WED AFTERNOON. THERE WILL BE
BETTER CHANCE OF ACCUMULATING SNOW OVER THE FAR WEST LATE WED INTO
WED NIGHT WHEN DEFORMATION BAND W/SYSTEM SETS UP IN STRONGLY
CYCLONIC NNE FLOW.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 549 PM EDT TUE MAR 15 2016
PATTERN OVER THE NEXT 1-2 WEEKS LOOKS QUITE CHANGEABLE WITH FLOW
TRANSITIONING BETWEEN PERIODS OF MORE PRONOUNCED SPLIT FLOW AND
PERIODS OF MORE CONSOLIDATED FLOW. OVER THE NEXT FEW DAYS...PATTERN
WILL BECOME BLOCKY OVER NAMERICA WITH DYNAMIC SYSTEM DEVELOPING INTO
THE GREAT LAKES BENEATH A DEVELOPING CLOSED HIGH TO THE N. THIS
BLOCKY PATTERN WILL BE SHORT-LIVED AS AMPLIFYING RIDGE ALONG THE W
COAST FORCES THE CLOSED HIGH TO DISSIPATE UNDER DEVELOPING ERN TROF
OVER THE WEEKEND. WRN RIDGE THEN WEAKENS WITH A MORE PRONOUNCED
SPLIT FLOW REDEVELOPING EARLY NEXT WEEK. AFTER THE MDT/HVY PCPN OVER
THE NEXT DAY OR TWO...A DRIER PATTERN WILL EVOLVE THRU EARLY NEXT
WEEK...THOUGH THERE WILL BE SOME -SHSN AND EVEN LES ASSOCIATED WITH
A SHORTWAVE AND COLDER AIR DIVING SE INTO THE ERN TROF LATER THIS
WEEKEND. FARTHER OUT...NAEFS 8-14 DAY OUTLOOK INDICATES BLO NORMAL
TEMPS BECOMING FAVORED W-E ACROSS MUCH OF CNTRL CANADA WHILE ABOVE
NORMAL TEMPS BECOME FAVORED ACROSS MUCH OF THE CONUS. THIS SUGGESTS
A POTENTIAL ACTIVE PATTERN WILL DEVELOP AS SHORTWAVES TRACK ALONG A
TIGHTENING THERMAL GRADIENT ACROSS THE NRN CONUS. SO...THE UPPER
LAKES MAY BE AFFECTED BY BOUTS OF PCPN EVERY 2-3 DAYS...BEGINNING
THE MIDDLE OF NEXT WEEK AND CONTINUING THRU THE END OF THE MONTH.
CERTAINLY NOT OUT OF THE QUESTION FOR SOME SNOW EVENTS TO OCCUR.
BEGINNING WED NIGHT/THU...MIDLEVEL LOW AND SFC LOW CENTERED VCNTY OF
SCNTRL UPPER MI WED EVENING WILL MOVE VERY LITTLE DURING THE NIGHT
BEFORE QUICKLY UNRAVELING AND DRIFTING S AND E ON THU. AT THE LOW
LEVELS...STRONGLY CYCLONIC FLOW WILL DOMINATE THE FCST AREA.
TO THE N AND W OF THE LOW...UPSLOPE NE TO NORTHERLY FLOW WILL
ENHANCE PCPN...ESPECIALLY SO OVER FAR WRN UPPER MI WHERE LOW-LEVEL
CYCLONIC FLOW IS EVEN MORE PRONOUNCED. THE FAR W IS ALSO CENTERED
UNDER AN AREA OF LINGERING DEEP LAYER FORCING PER QVECTORS...AND
THAT FORCING IS QUITE STRONG THRU MUCH OF THE NIGHT. LOW-LEVEL TEMPS
AREN`T QUITE LOW ENOUGH FOR LAKE ENHANCEMENT...BUT IT WOULDN`T TAKE
MUCH COOLING TO RESULT IN CONSIDERABLY HIGHER SNOW ACCUMULATIONS
THAN CURRENTLY EXPECTED. WITH THE 12Z MODEL RUNS INCLUDING THE 09Z
SREF...THE NAM/REGIONAL CANADIAN ARE ON THE HIGHER END OF THE QPF
SPECTRUM...SHOWING AMOUNTS OVER 1 INCH WED NIGHT OVER FAR WRN UPPER
MI. USED A MORE CONSERVATIVE APPROACH WITH AMOUNTS OF ABOUT 1/3RD TO
2/3RDS OF AN INCH. WITH SNOW RATIOS PROBABLY NOT HIGHER THAN AROUND
10 TO 1...SNOWFALL SHOULD BE ON THE ORDER OF 3-6 INCHES WED NIGHT
OVER GOGEBIC/ONTONAGON COUNTIES AND 2-4 INTO HOUGHTON COUNTY. ADVY
HAS BEEN HOISTED FOR THOSE 3 COUNTIES. SNOWFALL SHOULD DIMINISH TO
SUBADVY LEVELS IN THE BORDERING COUNTIES...WITH EVEN LIGHTER AMOUNTS
DOWN TO LESS THAN 1 INCH FARTHER E.
LINGERING LIGHT SNOW WILL DIMINISH THU AS ENTIRE SYSTEM WEAKENS AND
DRIFTS AND E. MIGHT SEE ANOTHER 1-2 INCHES OF SNOW ACCUMULATION
OVER THE W IN THE MORNING.
PATCHY -SN WILL CONTINUE TO DIMINISH THU NIGHT. FCST SOUNDINGS
SUGGEST SOME POTENTIAL FOR -FZDZ TO DEVELOP IN THE NNE WIND UPSLOPE
AREAS AS MOISTURE DEPTH SHRINKS TO THE LOW-LEVELS WHERE TEMPS IN THE
MOIST LAYER ARE AROUND -10C. WITH LOW CONFIDENCE...KEPT MENTION OUT
OF FCST FOR NOW.
CLOSED MID LEVEL HIGH THAT DEVELOPS OVER MANITOBA THU WEAKENS AND
DRIFTS SE ACROSS THE UPPER LAKES FRI/SAT...PROVIDING DRY WEATHER.
SKIES SHOULD BECOME MOSTLY CLEAR FRI/FRI NIGHT. WITH SFC HIGH PRES
OVER THE AREA FRI NIGHT...BEGAN TO TREND MIN TEMPS DOWN A BIT...
TOWARD THE LOWER TEENS IN THE TRADITIONAL COLD SPOTS.
SHORTWAVE DROPS SE THRU THE UPPER LAKES SAT NIGHT/SUN...BUT
TIMING/TRACK OF SHORTWAVE IS NOT WELL AGREED UPON WITH THE GFS MORE
AMPLIFIED/FARTHER S WITH SHORTWAVE TRACK THAN THE ECMWF/CANADIAN...
RESULTING IN A BETTER CHANCE OF -SHSN SUN ACROSS THE AREA AS DAYTIME
HEATING/MOISTURE OFF THE LAKE CONTRIBUTE TO A MORE TYPICAL
SPRINGTIME TYPE OF -SHSN REGIME. FOR NOW...LEANED FCST AWAY FROM THE
GFS. WITH 850MB TEMPS FALLING TO -15C OR SO BEHIND WAVE...EXPECT
SOME LIGHT LES TO DEVELOP OFF LAKE SUPERIOR SUN INTO MON.
THE FIRST IN WHAT COULD BE A SERIES OF LOW PRES SYSTEMS MOVING
ACROSS THE NRN CONUS MAY ARRIVE IN THE WRN GREAT LAKES LATE TUE OR
WED. WITH PLENTY OF UNCERTAINTY IN TIMING/TRACK AND THERMAL FIELDS
BASED ON RECENT GFS/ECMWF RUNS...ONLY SLIGHT CHC POPS WERE UTILIZED
ON TUE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 222 PM EDT TUE MAR 15 2016
MVFR TO VFR CONDITIONS AT TAF SITES WILL LOWER TO IFR AND POSSIBLY
LIFR LATER THIS EVENING INTO THE OVERNIGHT HOURS AS RAIN BEGINS TO
LIFT INTO AREA AHEAD OF A STRONG LOW PRESSURE SYSTEM APPROACHING FROM
THE CENTRAL PLAINS. RAIN IS EXPECTED TO MIX WITH OR CHANGE OVER TO
SNOW WED MORNING WITH STRONG LIFT AND COOLING FROM THE SYSTEM AND
THIS COULD LEAD TO LOWERING VSBYS IN SNOW BY LATE WED MORNING
ESPECIALLY AT KCMX IN FAVORABLE UPSLOPE EASTERLY FLOW. ALSO
STRENGTHENING EASTERLY WINDS AHEAD OF THE SYSTEM COULD LEAD TO WIND
GUSTS TO 30 KNOTS AT KCMX LATE TONIGHT INTO WEDNESDAY.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 427 PM EDT TUE MAR 15 2016
AS A DEEP LOW PRESSURE SYSTEM LIFTS INTO UPPER MICHIGAN STRONG EAST
WINDS WILL DEVELOP. THE STRONGEST WINDS FOR THIS FORECAST PERIOD ARE
EXPECTED LATE TONIGHT INTO EARLY THU AFTERNOON WHERE E-NE GALES OF
35 TO 45 KNOTS ARE EXPECTED ACROSS LAKE SUPERIOR AND A GALE WARNING
IS IN EFFECT. OTHERWISE...WINDS AT OR BELOW 25 KNOTS ARE EXPECTED
FROM THU NIGHT INTO THE WEEKEND AS THE LOW PRESSURE SYSTEM
WEAKENS AND MOVES E AND HIGH PRESSURE BUILDS IN FROM THE WEST.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY FROM 8 PM EDT /7 PM CDT/ WEDNESDAY TO 5
PM EDT /4 PM CDT/ THURSDAY FOR MIZ002-003-009-084.
LAKE SUPERIOR...
GALE WARNING FROM 4 AM TO 8 PM EDT WEDNESDAY FOR LSZ267.
GALE WARNING FROM 4 AM WEDNESDAY TO 4 AM EDT THURSDAY FOR LSZ265-
266.
GALE WARNING FROM 4 AM EDT /3 AM CDT/ WEDNESDAY TO NOON EDT /11
AM CDT/ THURSDAY FOR LSZ162-263-264.
LAKE MICHIGAN...
GALE WARNING FROM 5 AM TO 2 PM EDT WEDNESDAY FOR LMZ221-248-250.
&&
$$
SHORT TERM...VOSS
LONG TERM...ROLFSON
AVIATION...VOSS
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
428 PM EDT TUE MAR 15 2016
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 427 PM EDT TUE MAR 15 2016
WV IMAGERY AND RAP ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM
ALBERTA/SASK INTO THE WRN PLAINS WITH WEAK DOWNSTREAM RIDGING OVER
THE CENTRAL AND EASTERN GREAT LAKES INTO NW ONTARIO. AT THE SFC...SE
FLOW WAS INCREASING OVER NRN WI BETWEEN A RIDGE OVER THE CENTRAL AND
ERN LAKES AND A TROUGH FROM SRN MANITOBA THROUGH MN TO LOW PRES OVER
MO. A LINE SHRA EXTENDING FROM NW WI INTO SE WI/NE IL WERE SUPPORTED
BY STRONG LOW LEVEL MOISTURE INFLOW AND ISENTROPIC LIFT NOTED ON 290-
295K SFCS AHEAD OF THE TROUGH. THE INCREASING ISENTROPIC ASCENT AND
MID-LVL Q-VECT CONV AHEAD OF THE NEGATIVE-TILT TROUGH HAS RESULTED
IN CLOUDY SKIES ACROSS MUCH OF THE FCST AREA EXCEPT FOR FAR EAST
WHERE DRY EASTERLY FLOW AND PROXIMITY TO RIDGE HAS KEPT SKIES PARTLY
SUNNY. HIGH TEMPS TODAY HAVE RANGED FROM MID 50S FAR WEST AND EAST
TO THE LOWER 40S NEAR LAKE MI SHORE IN SE FLOW.
TONIGHT...AS THE NEG-TILT SHORTWAVE TROUGH OVER THE CENTRAL PLAINS
LIFTS TOWARD THE WRN GREAT LAKES THE SFC LOW IS EXPECTED TO DEEPEN
TO NEAR 987 MB OVER SRN WI BY 12Z WED. THE NAM AND GFS CONTINUE TO
TREND SLOWER WITH THE ARRIVAL OF THE PCPN BAND MOVING THROUGH WI SO
HAVE BACKED OFF ON INCREASING POPS TO LIKELY/CATEGORICAL OVER WEST
UNTIL LATE EVENING AND OVER THE CENTRAL COUNTIES UNTIL LATE TONIGHT
WHEN COMBINATION OF INCREASED UPPER DIVERGENCE IN COUPLED UPPER JET
STRUCTURE AND STRONG DEEP LAYER Q-VECT CONVERGENCE AHEAD OF
SHORTWAVE BEGINS TO OVERCOME DRY EASTERLY FLOW. THERMAL PROFILES AND
FCST SOUNDINGS SUGGEST THAT WITH THE WAA SURGE...THE PCPN BAND
COMING IN INITIALLY WILL REMAIN MOSTLY RAIN TONIGHT. ERLY WINDS WILL
ALSO BECOME GUSTY LATE TONIGHT...ESPECIALLY OVER THE KEWEENAW AND
NEAR LAKE MI WHERE GUSTS OVER 35 MPH ARE EXPECTED. ALSO KEPT IN
SLIGHT CHC OF THUNDER OVER SCNTRL UPPER LATE TONIGHT INTO EARLY WED
MORNING AS MODELS STILL SHOW NEG SHOWALTER INDICES AND MUCAPE OF A
FEW HUNDRED J/KG ON NOSE OF 85H THETA-E AND STRONG ISENTROPIC ASCENT.
WEDNESDAY...RAIN WILL BE FALLING HEAVILY IN THE MORNING SO PRECIP
LOADING COULD ALSO AID IN BRINGING STRONG/GUSTY WINDS TO SFC. AT THE
LEAST...DUE TO INCREASING PRESSURE GRADIENT TO NORTH OF DEEPENING
SFC LOW OVER WI DOWN TO LESS THAN 990MB BY 12Z WED...AREAS FAVORED
BY EAST WINDS SUCH AS LK MICHIGAN/BAY OF GREEN BAY AND ACROSS
KEWEENAW COULD SEE EAST WINDS GUSTING TO 30-40 MPH MUCH OF THE DAY.
AS DRY SLOT WITH SYSTEM AND Q-VECT DIV MOVES ACROSS CENTRAL AND ERN
AREAS EXPECT PRECIP TO DIMINISH THERE. EXCEPTION WILL BE OVER
WESTERN CWA WHERE DEEP LAYER Q-VECTOR CONVERGENCE EXPANDS ON NW SIDE
OF DEEPENING UPPER LOW AND STRONG SFC-H85 LOW MEANDERING OVER
NORTHERN LAKE MI AND DEFORMATION FORCING ALLOWS BAND TO SET UP OVER
THE WEST.
THE OTHER TRICKY PART OF THIS FCST WILL BE PTYPE AND POSSIBILITY OF
ACCUMULATING SNOW ON WED. MODEL SOUNDINGS...ESPECIALLY NAM...SUGGEST
POTENTIAL FOR DYNAMIC COOLING WITH HEAVIER PCPN BAND MOVING THROUGH
WED MORNING WITH A CHANGEOVER TO SNOW SHORTLY AFT 12Z. IF THIS
HAPPENS AS QUICKLY AS NAM INDICATES THERE COULD BE A POTENTIAL OF
SEVERAL INCHES OF WET SNOW WED MORNING OVER THE HIGHER TERRAIN AREAS
OF THE WEST HALF OF UPPER MI AS THIS HEAVIER BAND MOVES THROUGH THE
AREA. RIGHT NOW...SINCE THERE IS STILL SOME MODEL UNCERTAINTY WITH
THERMAL FIELDS/PROFILES HAVE ELECTED TO ONLY PUT IN A COUPLE INCHES
OF SNOW OVER MAINLY THE KEWEENAW AND WRN MQT/ERN BARAGA COUNTIES WED
MORNING BEFORE PCPN TAPERS OFF SOME WED AFTERNOON. THERE WILL BE
BETTER CHANCE OF ACCUMULATING SNOW OVER THE FAR WEST LATE WED INTO
WED NIGHT WHEN DEFORMATION BAND W/SYSTEM SETS UP IN STRONGLY
CYCLONIC NNE FLOW.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 416 AM EDT TUE MAR 15 2016
...EXTENT OF SNOW LATER WED INTO THU IS MAIN FOCUS...
TROUGH ALOFT WITH TWO DISTINCT SHORTWAVES EXPECTED LATE TONIGHT INTO
WED MORNING WESTERN CANADA TO WESTERN GREAT LAKES. LEAD SHORTWAVE/PV
ANAMOLY CROSSES INTO LOWER MICHIGAN WED MORNING. OTHER MAIN SHORTWAVE
OVER SOUTHERN SASKATCHEWAN SHEDS SOME ENERGY TOWARD THE WESTERN
GREAT LAKES SHORTWAVE AND THIS DEEPENS A TROUGH OVER UPPER GREAT
LAKES WED INTO THU. AT THE SFC...MAIN SFC LOW LATE TONIGHT INTO WED
MORNING WILL BE OVER WESTERN WI WITH WARM FRONT CNTRL WI TO CNTRL
LOWER MI. LOW ONLY DEEPENS ACROSS WI AS TROUGH ALOFT DEEPENS. SOLN
IS QUITE DIFFERENT THAN LOOKED LIKE 1-2 DAYS AGO WHEN THE LOW WAS
SUPPOSED TO LIFT ACROSS UPR MICHIGAN AND ON TO THE EAST. SOLN DOES
LOOK LIKE THE ECMWF IDEA FM A COUPLE DAYS AGO....ESPECIALLY WITH
REGARD TO SFC LOW POSITION AT 12Z WED.
SURGE OF RAIN SHOWERS...WITH POSSIBLE EMBEDDED CONVECTIVE ELEMENTS
IF NOT A FEW LIGHTNING STRIKES WILL BE SUPPORTED BY SHARP H85 THETA-
E RIDGE/ISENTROPIC ASCENT AND THETA-E ADVECTION. SI/S STAYING MOSTLY
ABOVE 0C AND AXIS OF ELEVATED CAPE STAYING OVER LOWER MI SHOULD
LIMIT COVERAGE AND NORTHWARD EXTENT OF TSRA ON WED MORNING. WILL
KEEP SLIGHT CHANCE FAR SCNTRL. THOUGH WARM AIR ADVECTION LEADS TO
STABLE TEMP PROFILE SFC-H7...CONCERNED WITH 50-60 KT H9-H8 WINDS
THAT COULD BE MIXED AT LEAST PARTIALLY TO SFC IN STRONGER CONVECTIVE
ELEMENTS OR IF THERE ARE TSRA. RAIN WILL BE FALLING HEAVILY SO
PRECIP LOADING COULD ALSO AID IN BRINGING STRONG/GUSTY WINDS TO SFC.
AT THE LEAST...DUE TO INCREASING PRESSURE GRADIENT TO NORTH OF
DEEPENING SFC LOW OVER WI DOWN TO LESS THAN 990MB BY 12Z WED...AREAS
FAVORED BY EAST WINDS SUCH AS LK MICHIGAN/BAY OF GREEN BAY AND
ACROSS KEWEENAW COULD SEE EAST WINDS GUSTING TO 30-40 MPH MUCH OF
THE DAY. AS THETA-E RIDGE GETS PINCHED OFF INTO WED AFTN WELL EAST
OF UPR MICHIGAN...FORCING FOR PRECIP WILL DIMINISH. ONLY EXCEPTION
IS OVER WESTERN CWA WHERE DEEP LAYER Q-VECTOR CONVERGERNCE EXPANDS
ON NW SIDE OF DEEPENING UPPER LOW AND STRONG SFC-H85 LOW MEANDERING
OVER NORTHERN WI AND PERHAPS AS FAR NORTH AS SCNTRL UPR MICHIGAN.
PTYPE REMAINS A CHALLENGE. ACCUMULATING SNOW IS A STRONG
POSSIBILITY...BUT EXTENT OF MODERATE OR EVEN HEAVY SNOW IS NOT AS
CERTAIN. KEWEENAW STILL IN LINE TO MIX WITH AND CHANGE TO SNOW ON
WED AS IS FAR WESTERN UPR MICHIGAN VCNTY OF KIWD. THEMAL PROFILE
DIFFERENCES ARE MOST NOTABLE ON WED MORNING. NAM SHOWS H85 TEMPS +5C
WHILE THE GFS IS -4C THOUGH NOT SATURATED AT THAT POINT. NAM
CONTINUES TO LINGER WARM AIR ALOFT H8-H7 LEADING TO SLEET OR FZRA
WHILE GFS COOLS SUFFICIENTLY FOR SNOW. DRYING ALOFT MAY CUT OUT OR
AT LEAST DIMINISH PRECIP IF NAM IS RIGHT BY MIDDAY. GEM-REGIONAL
LOOKS MORE LIKE THE NAM AND WPC PROBABILISTIC FORCASTS WOULD SUPPORT
GREATER CHANCES OF ACCUMULATING SNOW OVER FAR WEST CWA LATER WED
AFTN INTO WED NIGHT. AFTER ALL WAS SET AND DONE...AT LEAST WITH THIS
TURN IN THE MODELS...HAVE MODERATE SNOW AMOUNTS OF 3 TO 5 INCHES
OVER FAR WEST AND HIGHER TERAIN OF KEWEENAW WED THROUGH THU.
HEADLINE MAY BE NEEDED EVENTUALLY...BUT SINCE MOST OF SNOW ACCUMS
WILL NOT OCCUR UNTIL WED NIGHT AND THU...GOING TO GO WITH SPS ATTM.
LATEST WPC PROBABILITIES INDICATE 50-60 PCT CHANCE OF SEEING 6
INCHES OF SNOW IN 24 HOURS AT KIWD WITH SLIGHTLY LOWER PROBABILITIES
OF SEEING THAT MUCH OVER THE KEWEENAW AND HIGHER TERRAIN OF
BARAGA/MARQUETTE COUNTIES.
LATER THU INTO FRI...UPPER LOW UNRAVELS OVER THE UPPER GREAT LAKES
AND SFC LOW WEAKENS TO OVER 1000MB. DRY AIR MOVES IN FROM NORTHERN
ONTARIO AS SFC HIGH BUILDS SOUTHWARD. EXPECT LIGHT SNOW SHWOERS TO
FADE AWAY BY FRI...BUT IT WILL REMAIN SEASONABLY COOL WITH HIGHS IN
THE MID 30S NORTH TO AROUND 40 OVER SCNTRL. ANOTHER MORE PROGRESSIVE
UPPER LOW SLIDES OVER GREAT LAKES THIS WEEKEND AND NW FLOW BECOMES
ESTABLISHED ALOFT IN WAKE OF THAT FEATURE INTO EARLY NEXT WEEK.
SHORTWAVE TROUGH COMING THROUGH LATE IN THE WEEKEND COULD BRING SOME
LIGHT SNOW. TURNS PRETTY CHILLY BY EARLY NEXT WEEK...MAYBE EARLIER
PER GFS...WITH H85 TEMPS DOWN TO AROUND -15C. COULD SEE INTERMITTENT
LIGHT SNOW SHOWERS OFF LK SUPERIOR AS THE COLD AIR MOVES ACROSS
HELPED ALONG BY ANY SHORTWAVES DROPPING THROUGH. COOL WEATHER
PATTERN WILL CONTINUE THROUGH MUCH OF NEXT WEEK AS POSSIBLY LONGER
AS GFS/ECMWF ARE NOW TRENDING TOWARD MORE TROUGHING AND COLD AIR
HEADING TOWARD THE EASTER HOLDIAY WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 222 PM EDT TUE MAR 15 2016
MVFR TO VFR CONDITIONS AT TAF SITES WILL LOWER TO IFR AND POSSIBLY
LIFR LATER THIS EVENING INTO THE OVERNIGHT HOURS AS RAIN BEGINS TO
LIFT INTO AREA AHEAD OF A STRONG LOW PRESSURE SYSTEM APPROACHING FROM
THE CENTRAL PLAINS. RAIN IS EXPECTED TO MIX WITH OR CHANGE OVER TO
SNOW WED MORNING WITH STRONG LIFT AND COOLING FROM THE SYSTEM AND
THIS COULD LEAD TO LOWERING VSBYS IN SNOW BY LATE WED MORNING
ESPECIALLY AT KCMX IN FAVORABLE UPSLOPE EASTERLY FLOW. ALSO
STRENGTHENING EASTERLY WINDS AHEAD OF THE SYSTEM COULD LEAD TO WIND
GUSTS TO 30 KNOTS AT KCMX LATE TONIGHT INTO WEDNESDAY.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 427 PM EDT TUE MAR 15 2016
AS A DEEP LOW PRESSURE SYSTEM LIFTS INTO UPPER MICHIGAN STRONG EAST
WINDS WILL DEVELOP. THE STRONGEST WINDS FOR THIS FORECAST PERIOD ARE
EXPECTED LATE TONIGHT INTO EARLY THU AFTERNOON WHERE E-NE GALES OF
35 TO 45 KNOTS ARE EXPECTED ACROSS LAKE SUPERIOR AND A GALE WARNING
IS IN EFFECT. OTHERWISE...WINDS AT OR BELOW 25 KNOTS ARE EXPECTED
FROM THU NIGHT INTO THE WEEKEND AS THE LOW PRESSURE SYSTEM
WEAKENS AND MOVES E AND HIGH PRESSURE BUILDS IN FROM THE WEST.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY FROM 8 PM EDT /7 PM CDT/ WEDNESDAY TO 5
PM EDT /4 PM CDT/ THURSDAY FOR MIZ002-003-009-084.
LAKE SUPERIOR...
GALE WARNING FROM 4 AM TO 8 PM EDT WEDNESDAY FOR LSZ267.
GALE WARNING FROM 4 AM WEDNESDAY TO 4 AM EDT THURSDAY FOR LSZ265-
266.
GALE WARNING FROM 4 AM EDT /3 AM CDT/ WEDNESDAY TO NOON EDT /11
AM CDT/ THURSDAY FOR LSZ162-263-264.
LAKE MICHIGAN...
GALE WARNING FROM 5 AM TO 2 PM EDT WEDNESDAY FOR LMZ221-248-250.
&&
$$
SHORT TERM...VOSS
LONG TERM...JLA
AVIATION...VOSS
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
330 PM EDT TUE MAR 15 2016
LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM/MARINE
.SYNOPSIS...
ISSUED AT 330 PM EDT TUE MAR 15 2016
A DEVELOPING DEEP LOW PRESSURE SYSTEM WILL SWEEP SHOWERS AND
THUNDERSTORMS THROUGH SOUTHWEST LOWER MICHIGAN TONIGHT. SOME OF THE
STORMS IN THE FAR SOUTHWEST CORNER OF THE LOWER PENINSULA MAY
CONTAIN HAIL AND STRONG WINDS TONIGHT. THE LOW ITSELF WILL PRODUCE
WIDESPREAD STRONG WINDS ON WEDNESDAY WHEN MANY AREAS WILL SEE WIND
GUSTS IN THE 40 TO 50 MPH RANGE. COOLER WEATHER WILL FILTER IN
BEHIND THIS MID WEEK SYSTEM WITH HIGHS MIGRATING BACK TO THE 40S FOR
THURSDAY AND FRIDAY.
&&
.SHORT TERM...(TONIGHT AND WEDNESDAY)
ISSUED AT 330 PM EDT TUE MAR 15 2016
TWO ITEMS TO DEAL WITH TONIGHT AND WEDNESDAY. THE FIRST BEING THE
THUNDERSTORM FORECAST AND THREAT FOR SEVERE TONIGHT. THE SECOND
BEING STRONG SYNOPTIC SCALE WINDS THAT ARE FORECAST FOR WEDNESDAY.
REGARDING THE STORM AND SEVERE CHANCES FOR TONIGHT. CONSIDERABLE
CLEARING HAS OCCURRED THIS AFTERNOON WHICH IS ALLOWING DAY TIME
HEATING TO BOOST TEMPS A BIT. READINGS HAVE PUSHED INTO THE 60S OVER
FAR SOUTHWEST LOWER MI TOWARDS AZO AND BEH. BEH HAS REACHED 64
DEGREES. OF MORE IMPORTANCE IS THE FACT THAT DEW POINTS HAVE SURGED
INTO THE UPPER 50S TO LOW 60S OVER A FAIRLY SIZABLE AREA OVER
ILLINOIS AND INDIANA. THIS WILL ACT TO INCREASE INSTABILITY TONIGHT
AS THIS MOISTURE SURGES INTO THE SOUTHWEST CORNER OF THE STATE AS
THE WIND FIELDS INCREASE. LOW LEVEL MOISTURE INCREASE ALONG WITH MID
LEVEL COOLING FROM THE DYNAMIC 500MB SHORTWAVE WILL TEND TO INCREASE
INSTABILITY. THE RUC HAS DEEP LAYER CAPE VALUES INCREASING TO AROUND
1000 J/KG IN THE GRR FORECAST AREA. THE HIGHEST CAPE OVER THE
LARGEST AREA (MKG/BIV/GRR/AZO/BTL) OCCURS AROUND 2AM TO 3AM. BOTTOM
LINE...STILL EXPECTING BROKEN LINES OF SHOWERS AND THUNDERSTORMS TO
SWEEP NORTHWARD THROUGH THE AREA TONIGHT. ANY CHANCE FOR SEVERE IS
LIKELY LIMITED TO THE SPC SLIGHT RISK AREA WHERE DYNAMICS AND
INSTABILITY ARE MAXIMIZED. HAIL OF ONE HALF TO ONE INCH REMAINS THE
PRIMARY THREAT WITH WIND GUSTS TO AROUND 50 KNOTS A POTENTIAL THREAT
AS WELL.
REGARDING THE WIND TOMORROW...HAVE OPTED TO ISSUE A WIND ADVISORY
FOR THE ENTIRE FORECAST AREA. A VERY DEEP LOW FOR ANY TIME OF YEAR
IS FORECAST TO BOTTOM OUT IN THE LOW 980S TOMORROW MORNING. A TIGHT
PRESSURE GRADIENT WILL BE SITUATED OVER ALL OF SOUTHWEST LOWER
MICHIGAN. BEST ISALLOBARIC COMPONENT LOOKS TO BE WEST OF US THOUGH.
WIND ADVISORY CRITERIA GUSTS OF 45+ MPH LOOK LIKELY...ESPECIALLY FOR
ABOUT THE SOUTHERN HALF OF THE FORECAST AREA (I96 AND I94 CORRIDORS)
WHERE WE MAY SEE A FAIR AMOUNT OF SUNSHINE/MIXING IN THE AFTERNOON.
POWER OUTAGES ARE A POSSIBILITY TOMORROW. THINKING THE CORE OF THE
STRONGEST WINDS IN THE HIGHER RISK AREA MAY BE FOR BIV/GRR/LWA AND
AZO.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 330 PM EDT TUE MAR 15 2016
THE MOST SIGNIFICANT ASPECT OF THE WEATHER OVER SOUTHWEST MICHIGAN
DURING THIS TIME FRAME IS TEMPERATURES FALL BACK TO NEAR NORMAL...
THEN STAY THAT WAY FOR AT LEAST A WEEK. AS THE COLDER AIR MOVES IN
WEDNESDAY NIGHT INTO THURSDAY WE MORE THAN LIKELY WILL SEE LIGHT
RAIN SHOWERS. THE NEXT SIGNIFICANT WEATHER EVENT WILL BE WEDNESDAY
INTO THURSDAY. THIS WOULD BE A RAIN CHANGING TO SNOW SHOWERS SORT OF
EVENT.
AT UPPER LEVELS A BLOCKING HIGH DEVELOPS EAST OF GREENLAND BY
THURSDAY AND THAT FORCES THE NORTHERN STREAM TO DIG WELL SOUTH OVER
CENTRAL NORTH AMERICA... INSTEAD OF STAYING UP IN CENTRAL CANADA HAS
IT HAS BEEN DOING OVER THE PAST WEEK. THIS ALSO HELPS TO PUSH THE
CURRENT SYSTEM OUT OF THE AREA BY FRIDAY. THE NEXT SYSTEM BEHIND THE
CURRENT ONE WILL LIKELY DEVELOP SOUTH OF MICHIGAN AND HEAD TO THE
EAST COAST OVER THE WEEKEND. BEHIND THAT SYSTEM THE NEXT SYSTEM
COMES FROM THE NORTH PACIFIC AND WOULD MOVE INTO OUR AREA AROUND
WEDNESDAY. THERE IS SOME NORTHERN STREAM ENERGY FOR THIS SYSTEM
SO...THIS COULD BE ANOTHER STRONG SYSTEM. THE NORTHERN STREAM MAY
HAVE ENOUGH COLD AIR TO TURN THE SHOWERS TO SNOW SHOWERS BEYOND
WEDNESDAY.
FOR THE PERIOD OF WEDNESDAY NIGHT INTO THURSDAY...THE SYSTEM
CURRENTLY IN OUR AREA GETS SHEARED OUT BUT AS THIS HAPPENS THE UPPER
TROUGH DIGS SOUTHWARD SO WE GET A PERIOD OF SHOWERS WEDNESDAY NIGHT
INTO THURSDAY. IT IS NOT IMPOSSIBLE WE COULD SEE THE RAIN SHOWERS
CHANGE TO SNOW SHOWERS BEFORE THE PRECIPITATION ENDS THURSDAY NIGHT
OR EARLY FRIDAY MORNING.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 130 PM EDT TUE MAR 15 2016
THERE IS A BAND OF MVFR CIGS ALONG I-96 EARLY THIS AFTERNOON BUT
SKIES ARE NEARLY CLEAR ALONG I-94. THAT CLEARING WILL LIFT NORTH
OVER THE NEXT FEW HOURS...ALL SITES SHOULD BE VFR BY 21Z OR SO.
VFR CONDITIONS SHOULD PREVAIL TILL CLOSE TO 06Z.
TONIGHT A RAPIDLY DEEPENING STORM SYSTEM WILL BRING A PERIOD OF
SHOWERS...SCATTERED THUNDERSTORMS AND IFR CIGS/VSBY.. MOST OF THAT
WILL BE BETWEEN 06Z AND 12Z. ONCE THAT MOVES THROUGH WRAP AROUND
SHOWERS...VERY STRONG WINDS AND MVFR CIGS WILL PREVAIL THROUGH THE
DAY TIME HOURS OF WEDNESDAY. WINDS MAY GUST OVER 40 KNOTS AT
TIMES DURING THE DAYLIGHT HOURS TO WEDNESDAY.
&&
.MARINE...
ISSUED AT 330 PM EDT TUE MAR 15 2016
ISSUED A GALE WARNING EARLIER TODAY FOR WEDNESDAY AND WEDNESDAY
EVENING AS A STRONG LOW DEVELOPS IN WISCONSIN. THE LOW IS FORECAST
TO DEEPEN RAPIDLY TONIGHT AND BOTTOM OUT AROUND 983MB/S WEDNESDAY
MORNING. STRONG SOUTH TO SOUTHWEST WINDS ARE FORECAST TO REACH GALE
FORCE ON WEDNESDAY LIKELY PEAKING IN 40 TO 45 KNOT RANGE. WAVES WILL
BUILD TOWARDS 10 FEET ON WEDNESDAY WITH THE LARGEST WAVES LIKELY
NORTH OF MUSKEGON GIVEN THE SOUTHERLY FLOW.
THE LOW WILL FILL/WEAKEN WEDNESDAY NIGHT AND THURSDAY WITH THE WINDS
AND WAVES GRADUALLY SUBSIDING OVER TIME.
&&
.HYDROLOGY...
ISSUED AT 1136 AM EDT TUE MAR 15 2016
SOME POINTS ALONG THE GRAND RIVER AND ITS TRIBUTARIES CONTINUE TO
RUN ABOVE BANKFULL. THE GOING FORECASTS ARE BASED ON BASIN AVERAGE
RAINFALL OF 0.25 TO 0.5 INCHES EXPECTED FROM THE SHOWERS AND
THUNDERSTORMS TUE NIGHT INTO EARLY WED MORNING. NO OTHER HEAVY
RAIN THREATS ARE EXPECTED THROUGH THE REST OF THIS WEEK... SO THAT
WILL GIVE THE RIVERS SOME TIME TO SUBSIDE.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WIND ADVISORY FROM 6 AM TO 10 PM EDT WEDNESDAY FOR MIZ037>040-
043>046-050>052-056>059-064>067-071>074.
LM...GALE WARNING FROM 6 AM WEDNESDAY TO 2 AM EDT THURSDAY FOR
LMZ844>849.
&&
$$
SYNOPSIS...DUKE
SHORT TERM...DUKE
LONG TERM...WDM
AVIATION...WDM
HYDROLOGY...CAS
MARINE...DUKE
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
240 PM EDT TUE MAR 15 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 517 AM EDT TUE MAR 15 2016
WV IMAGERY AND RAP ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM
ALBERTA/SASK INTO THE WRN PLAINS WITH DOWNSTREAM RIDGING FROM THE
WRN GREAT LAKES INTO NW ONTARIO. AT THE SFC...SE FLOW WAS
INCREASING OVER THE MS VALLEY BETWEEN A RIDGE OVER THE WRN LAKES AND
A TROUGH FROM SRN MANITOBA THROUGH THE ERN DAKOTAS TO LOW PRES OVER
ERN KS. SHRA/TSRA OVER SRN MN INTO IA WERE SUPPORTED BY STRONG LOW
LEVEL MOISTURE INFLOW AND ISENTROPIC LIFT AHEAD OF THE TROUGH. EVEN
WITH THE RIDGE OVER UPPER MI...CLOUDY SKIES PREVAILED WITH TEMPS
WELL ABOVE NORMAL FROM THE UPPER 30S TO AROUND 40.
TODAY...AS THE 120 KNOT 250-300 MB JET INTO THE GREAT BASIN AND
CNTRL ROCKIES MOVES INTO THE PLAINS THE MID LEVEL TROUGH WILL
STRENGTHEN AND THE SFC LOW MOVING INTO SE IA WILL DEEPEN. THE STRONG
DYNAMICS SUPPORTING THE UPSTREAM PCPN WILL GRADUALLY MOVE TOWARD
UPPER MI BUT SHOULD REMAIN TO THE SOUTH AND WEST TIL THIS AFTERNOON
WHEN SOME PCPN MAY MOVE INTO THE WEST.
TONIGHT...AS THE STACKED LOW GRADUALLY LIFTS TO THE NE THE SFC LOW
IS EXPECTED TO DEEPEN TO NEAR 985 MB OVER SRN WI. THE GFS/NAM HAVE
CONTINUED TO TREND SLOWER WITH THE ARRIVAL OF THE LARGE PCPN BAND IS
IN BETTER AGREEMENT WITH THE MORE CONSISTENT ECMWF. SO...EXPECT THE
BULK OF THE HEAVIER PCPN TO ARRIVE AFTER 06Z AND REACH THE NORTH AND
EAST PORTIONS OF THE CWA TOWARD 12Z. THERMAL PROFILES AND FCST
SOUNDINGS SUGGEST THAT WITH THE WAA SURGE...THE PCPN WILL REMAIN AS
RAIN TONIGHT. ERLY WINDS WILL ALSO BECOME GUSTY LATE
TONIGHT...ESPECIALLY OVER THE KEWEENAW AND NEAR LAKE MI WHERE GUSTS
OVER 35 MPH ARE EXPECTED.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 416 AM EDT TUE MAR 15 2016
...EXTENT OF SNOW LATER WED INTO THU IS MAIN FOCUS...
TROUGH ALOFT WITH TWO DISTINCT SHORTWAVES EXPECTED LATE TONIGHT INTO
WED MORNING WESTERN CANADA TO WESTERN GREAT LAKES. LEAD SHORTWAVE/PV
ANAMOLY CROSSES INTO LOWER MICHIGAN WED MORNING. OTHER MAIN SHORTWAVE
OVER SOUTHERN SASKATCHEWAN SHEDS SOME ENERGY TOWARD THE WESTERN
GREAT LAKES SHORTWAVE AND THIS DEEPENS A TROUGH OVER UPPER GREAT
LAKES WED INTO THU. AT THE SFC...MAIN SFC LOW LATE TONIGHT INTO WED
MORNING WILL BE OVER WESTERN WI WITH WARM FRONT CNTRL WI TO CNTRL
LOWER MI. LOW ONLY DEEPENS ACROSS WI AS TROUGH ALOFT DEEPENS. SOLN
IS QUITE DIFFERENT THAN LOOKED LIKE 1-2 DAYS AGO WHEN THE LOW WAS
SUPPOSED TO LIFT ACROSS UPR MICHIGAN AND ON TO THE EAST. SOLN DOES
LOOK LIKE THE ECMWF IDEA FM A COUPLE DAYS AGO....ESPECIALLY WITH
REGARD TO SFC LOW POSITION AT 12Z WED.
SURGE OF RAIN SHOWERS...WITH POSSIBLE EMBEDDED CONVECTIVE ELEMENTS
IF NOT A FEW LIGHTNING STRIKES WILL BE SUPPORTED BY SHARP H85 THETA-
E RIDGE/ISENTROPIC ASCENT AND THETA-E ADVECTION. SI/S STAYING MOSTLY
ABOVE 0C AND AXIS OF ELEVATED CAPE STAYING OVER LOWER MI SHOULD
LIMIT COVERAGE AND NORTHWARD EXTENT OF TSRA ON WED MORNING. WILL
KEEP SLIGHT CHANCE FAR SCNTRL. THOUGH WARM AIR ADVECTION LEADS TO
STABLE TEMP PROFILE SFC-H7...CONCERNED WITH 50-60 KT H9-H8 WINDS
THAT COULD BE MIXED AT LEAST PARTIALLY TO SFC IN STRONGER CONVECTIVE
ELEMENTS OR IF THERE ARE TSRA. RAIN WILL BE FALLING HEAVILY SO
PRECIP LOADING COULD ALSO AID IN BRINGING STRONG/GUSTY WINDS TO SFC.
AT THE LEAST...DUE TO INCREASING PRESSURE GRADIENT TO NORTH OF
DEEPENING SFC LOW OVER WI DOWN TO LESS THAN 990MB BY 12Z WED...AREAS
FAVORED BY EAST WINDS SUCH AS LK MICHIGAN/BAY OF GREEN BAY AND
ACROSS KEWEENAW COULD SEE EAST WINDS GUSTING TO 30-40 MPH MUCH OF
THE DAY. AS THETA-E RIDGE GETS PINCHED OFF INTO WED AFTN WELL EAST
OF UPR MICHIGAN...FORCING FOR PRECIP WILL DIMINISH. ONLY EXCEPTION
IS OVER WESTERN CWA WHERE DEEP LAYER Q-VECTOR CONVERGERNCE EXPANDS
ON NW SIDE OF DEEPENING UPPER LOW AND STRONG SFC-H85 LOW MEANDERING
OVER NORTHERN WI AND PERHAPS AS FAR NORTH AS SCNTRL UPR MICHIGAN.
PTYPE REMAINS A CHALLENGE. ACCUMULATING SNOW IS A STRONG
POSSIBILITY...BUT EXTENT OF MODERATE OR EVEN HEAVY SNOW IS NOT AS
CERTAIN. KEWEENAW STILL IN LINE TO MIX WITH AND CHANGE TO SNOW ON
WED AS IS FAR WESTERN UPR MICHIGAN VCNTY OF KIWD. THEMAL PROFILE
DIFFERENCES ARE MOST NOTABLE ON WED MORNING. NAM SHOWS H85 TEMPS +5C
WHILE THE GFS IS -4C THOUGH NOT SATURATED AT THAT POINT. NAM
CONTINUES TO LINGER WARM AIR ALOFT H8-H7 LEADING TO SLEET OR FZRA
WHILE GFS COOLS SUFFICIENTLY FOR SNOW. DRYING ALOFT MAY CUT OUT OR
AT LEAST DIMINISH PRECIP IF NAM IS RIGHT BY MIDDAY. GEM-REGIONAL
LOOKS MORE LIKE THE NAM AND WPC PROBABILISTIC FORCASTS WOULD SUPPORT
GREATER CHANCES OF ACCUMULATING SNOW OVER FAR WEST CWA LATER WED
AFTN INTO WED NIGHT. AFTER ALL WAS SET AND DONE...AT LEAST WITH THIS
TURN IN THE MODELS...HAVE MODERATE SNOW AMOUNTS OF 3 TO 5 INCHES
OVER FAR WEST AND HIGHER TERAIN OF KEWEENAW WED THROUGH THU.
HEADLINE MAY BE NEEDED EVENTUALLY...BUT SINCE MOST OF SNOW ACCUMS
WILL NOT OCCUR UNTIL WED NIGHT AND THU...GOING TO GO WITH SPS ATTM.
LATEST WPC PROBABILITIES INDICATE 50-60 PCT CHANCE OF SEEING 6
INCHES OF SNOW IN 24 HOURS AT KIWD WITH SLIGHTLY LOWER PROBABILITIES
OF SEEING THAT MUCH OVER THE KEWEENAW AND HIGHER TERRAIN OF
BARAGA/MARQUETTE COUNTIES.
LATER THU INTO FRI...UPPER LOW UNRAVELS OVER THE UPPER GREAT LAKES
AND SFC LOW WEAKENS TO OVER 1000MB. DRY AIR MOVES IN FROM NORTHERN
ONTARIO AS SFC HIGH BUILDS SOUTHWARD. EXPECT LIGHT SNOW SHWOERS TO
FADE AWAY BY FRI...BUT IT WILL REMAIN SEASONABLY COOL WITH HIGHS IN
THE MID 30S NORTH TO AROUND 40 OVER SCNTRL. ANOTHER MORE PROGRESSIVE
UPPER LOW SLIDES OVER GREAT LAKES THIS WEEKEND AND NW FLOW BECOMES
ESTABLISHED ALOFT IN WAKE OF THAT FEATURE INTO EARLY NEXT WEEK.
SHORTWAVE TROUGH COMING THROUGH LATE IN THE WEEKEND COULD BRING SOME
LIGHT SNOW. TURNS PRETTY CHILLY BY EARLY NEXT WEEK...MAYBE EARLIER
PER GFS...WITH H85 TEMPS DOWN TO AROUND -15C. COULD SEE INTERMITTENT
LIGHT SNOW SHOWERS OFF LK SUPERIOR AS THE COLD AIR MOVES ACROSS
HELPED ALONG BY ANY SHORTWAVES DROPPING THROUGH. COOL WEATHER
PATTERN WILL CONTINUE THROUGH MUCH OF NEXT WEEK AS POSSIBLY LONGER
AS GFS/ECMWF ARE NOW TRENDING TOWARD MORE TROUGHING AND COLD AIR
HEADING TOWARD THE EASTER HOLDIAY WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 222 PM EDT TUE MAR 15 2016
MVFR TO VFR CONDITIONS AT TAF SITES WILL LOWER TO IFR AND POSSIBLY
LIFR LATER THIS EVENING INTO THE OVERNIGHT HOURS AS RAIN BEGINS TO
LIFT INTO AREA AHEAD OF A STRONG LOW PRESSURE SYSTEM APPROACHING FROM
THE CENTRAL PLAINS. RAIN IS EXPECTED TO MIX WITH OR CHANGE OVER TO
SNOW WED MORNING WITH STRONG LIFT AND COOLING FROM THE SYSTEM AND
THIS COULD LEAD TO LOWERING VSBYS IN SNOW BY LATE WED MORNING
ESPECIALLY AT KCMX IN FAVORABLE UPSLOPE EASTERLY FLOW. ALSO
STRENGTHENING EASTERLY WINDS AHEAD OF THE SYSTEM COULD LEAD TO WIND
GUSTS TO 30 KNOTS AT KCMX LATE TONIGHT INTO WEDNESDAY.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 517 AM EDT TUE MAR 15 2016
AS A DEEP LOW PRESSURE SYSTEM LIFTS INTO UPPER MICHIGAN STRONG EAST
WINDS WILL DEVELOP. THE STRONGEST WINDS FOR THIS FORECAST PERIOD ARE
EXPECTED LATE TUESDAY NIGHT INTO EARLY THU WHERE EAST GALES OF 35 TO
45 KNOTS ARE EXPECTED AND A GALE WARNING IS IN EFFECT.
OTHERWISE...WINDS AT OR BELOW 25 KNOTS ARE EXPECTED FROM THU NIGHT
THROUGH SATURDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 4 AM TO 8 PM EDT WEDNESDAY FOR LSZ267.
GALE WARNING FROM 4 AM WEDNESDAY TO 4 AM EDT THURSDAY FOR LSZ265-
266.
GALE WARNING FROM 4 AM EDT /3 AM CDT/ WEDNESDAY TO NOON EDT /11
AM CDT/ THURSDAY FOR LSZ162-263-264.
LAKE MICHIGAN...
GALE WARNING FROM 5 AM TO 2 PM EDT WEDNESDAY FOR LMZ221-248-250.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...VOSS
MARINE...JLB
AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
316 PM CDT TUE MAR 15 2016
.DISCUSSION...
Issued at 315 PM CDT TUE MAR 15 2016
Main concern continues to be focused on later this afternoon and
this evening for the potential of severe weather.
The HRRR has been consistent in developing convection along the
surface low and northeast along the inverted surface trough. Surface
analysis for 19Z shows the surface low is likely in between Moberly,
Columbia and Hannibal. This area has remained cloud free and is
likely to be able to build enough instability, perhaps as high as
1500 J/kg of SBCAPE. 0-6km shear though is very favorable for storm
organization and may be pushing 60 KTs. The good news is that this
environment should be east of the forecast area, given the forecasts
for the surface low. But there may be enough MUCAPE in the post-
frontal regime that when combined the forcing of the upper trough,
that a few thunderstorms cold develop late in the afternoon to early
evening. The CAPE/shear combination is not as robust as it is in the
equivalent warm sector but the environment may be supportive of
marginally severe hail.
The other issue in the short-term deals with the backside of this
system and the potential for strong winds. It is usually very
favorable for advisory level surface winds when an upper level PV
anomaly moves overhead. However, the surface low in this case is
well removed from the area and moving into Wisconsin or the UP. The
pressure gradient magnitude drops off to between 25 and 30 ubars/km
through the morning hours. Also, by the time deeper mixing into
strong winds aloft occurs, the pressure gradient is weakening and
winds aloft diminish. So it just doesn`t look like the ingredients
line up to get a good synoptic wind event to the levels that an
advisory would be needed. But it will still be windy across the
region tomorrow morning through early in the afternoon. The
strongest winds will be in our northeastern zones, closest to the
departing the surface low.
While the weather will be cooler than the recent past, overall it
looks to be quiet as well. The area will be in a general
northwesterly flow pattern with a weak blocking signal over the
Great Lakes. With predominantly cyclonic curvature to the flow over
or region, temperatures will be on the cool side. It`s not really
until the end of next week, when the upper ridge over the west
begins to shift eastward, that flow turns back to the south and we
warm back into the 70s.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday Afternoon)
Issued at 1217 PM CDT TUE MAR 15 2016
There may be a few hours of MVFR to low MVFR ceilings this afternoon
in the wake of the front. A few showers are also possible. Winds
should also begin to increase and become gusty through the afternoon
afternoon hours. This evening and through the overnight into
tomorrow, VFR conditions are expected.
&&
.EAX Watches/Warnings/Advisories...
KS...NONE.
MO...NONE.
&&
$$
UPDATE...CDB
DISCUSSION...CDB
AVIATION...CDB