Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 04/21/15
AREA FORECAST DISCUSSION
NWS PUEBLO CO
603 PM MDT MON APR 20 2015
.UPDATE...
ISSUED AT 553 PM MDT MON APR 20 2015
UPDATED TO ADJUST SHOWER CHANCES ACROSS THE PLAINS...GENERALLY
SOUTH OF HIGHWAY 50 FOR THIS EVENING. MOST HIGH-RES MODELS HAVE
AN AREA OF SHOWER ACTIVITY DROPPING ACROSS THE PLAINS AND MADE
ADJUSTMENTS TO ACCOUNT FOR THIS. NO OTHER UPDATES AT THIS TIME.
MOZLEY
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 318 PM MDT MON APR 20 2015
CURRENTLY...
MODEST NW FLOW PREVAILS ALOFT ACROSS THE REGION. ISOLD TO SCTD SHRA
AND -TSRA WERE NOTED OVER THE HIGHER TRRN AND WERE MOVING ONTO THE
PLAINS. MOST UNSTABLE ATMOSPHERE WAS NOTED OVER THE SPANISH PEAKS
REGION PER RADAR AND TOTAL LTG DATA. TEMPS WERE COOL AT 3 PM WITH
TEMPS IN THE U50S/L60S PLAINS AND 50S VALLEYS.
REST OF TODAY AND THIS EVENING....
ISOLD PRECIP ACTIVITY WILL CONTINUE OVER THE HIGHER TRRN WITH SOME
OF THIS ACTIVITY MOVING ONTO THE PLAINS. ANY ACTIVITY OVER THE PLAINS
WILL GENERALLY REMAIN ISOLD...WITH A BIT MORE COVERAGE EXPECTED
ALONG THE CO/NM BORDER. ACTIVITY WILL REMAIN WEAK WITH BIGGEST
CONCERN BEING CG ACTIVITY.
TONIGHT...
ANY PRECIP OVER THE REGION WILL DIE BY LATER THIS EVENING IF NOT
EARLIER. HRRR AND NAM GUIDANCE DO SHOW A TSTORM OR TWO OVER THE
PLAINS EARLY THIS EVENING UNDER THE MODEST NW FLOW. TEMPS WILL COO
INTO THE 30-35F RANGE ACROSS THE PLAINS WITH 20S IN THE VALLEYS.
TUESDAY...
IT WILL BE WARMER TOMORROW WITH HIGHS EXPECTED TO REACH INTO THE
LOWER 70S MOST OF THE PLAINS...AND 60S VALLEYS. I DO EXPECT THAT WE
WILL SEE A PRECIP PATTERN SIMILAR TO TODAY IN THAT SHOWERS AND
STORMS WILL FORM OVER THE MTNS AND MOVE ONTO THE PLAINS. ACTIVITY
WILL BE A LITTLE MORE ROBUST TOMORROW AS WE SHOULD SEE A BIT MORE
INSTABILITY TOMORROW...HOWEVER NO STRONG ACTIVITY IS ANTICIPATED AT
THIS TIME. /HODANISH
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 318 PM MDT MON APR 20 2015
RELATIVELY ACTIVE LONGER TERM IS ANTICIPATED WITH PRIMARY
METEOROLOGICAL ISSUES BEING POPS(INCLUDING THUNDERSTORMS
AND MOUNTAIN SNOWS)...TEMPERATURES AND GUSTY WINDS AT TIMES.
RECENT LONGER TERM COMPUTER SIMULATIONS...FORECAST MODEL
SOUNDINGS...PV ANALYSIS AND ADDITIONAL METEOROLOGICAL PARAMETERS
SUGGEST THAT TRANSITORY UPPER RIDGING TO SOUTHWESTERLY UPPER
FLOW WILL BE IN PLACE OVER THE FORECAST DISTRICT FROM TUESDAY
NIGHT INTO THURSDAY IN ADVANCE OF NEXT UPPER DISTURBANCE
IMPACTING CWFA FROM LATER THURSDAY INTO FRIDAY NIGHT WITH
ANOTHER UPPER DISTURBANCE IMPACTING THE FORECAST DISTRICT
FROM SATURDAY INTO SATURDAY NIGHT.
AT LOWER LEVELS...SURFACE HIGH CENTERED OVER SOUTH DAKOTA AT 06Z
WEDNESDAY SLOWLY SHIFTS INTO THE UPPER MIDWEST BY FRIDAY
NIGHT...WHILE SURFACE LOW DEVELOPS OVER SOUTHEASTERN COLORADO BY
06Z FRIDAY BEFORE SHIFTING INTO OKLAHOMA BY 06Z SATURDAY AS
NORTHERLY SURFACE SURGE PUSHES ACROSS EASTERN SECTIONS FRIDAY
NIGHT.
THE COMBINATION OF THESE METEOROLOGICAL PARAMETERS IN
COMBINATION WITH ADEQUATE ATMOSPHERIC MOISTURE WILL ALLOW FOR
UNSETTLED CONDITIONS AT TIMES OVER THE CWFA DURING THE
MAJORITY OF THE LONGER TERM IN COMBINATION WITH TEMPERATURES
RUNNING WITHIN A CATEGORY OR SO OF MID TO LATE APRIL
CLIMATOLOGICAL AVERAGES MOST LOCATIONS...ALTHOUGH SOME
ADDITIONAL WARMING IS PROJECTED TO DEVELOP BY EARLY NEXT WEEK.
AT THIS TIME...IT APPEARS THAT THE HIGHEST POTENTIAL OF STRONGER
CONVECTIVE POTENTIAL DURING THE LONGER TERM MAY BE REALIZED
WEDNESDAY AND THURSDAY(ESPECIALLY EASTERN SECTIONS) AS DEEPER
ATMOSPHERIC MOISTURE INTERACTS WITH UPPER IMPULSES TO PRODUCE
LOCALIZED POTENTIAL CAPES/LIS AND BULK SHEARS VALUES OF -5C/1000+
J/KG AND 40 KNOTS RESPECTIVELY BOTH DAYS. AS ALWAYS...WFO PUEBLO
WILL MONITOR CLOSELY.
IN ADDITION...HIGHER ELEVATION ACCUMULATING SNOW IS ANTICIPATED
AT TIMES WITH GUSTY GRADIENT WINDS ALSO POSSIBLE...PRIMARILY FROM
FRIDAY INTO FRIDAY NIGHT. FINALLY...AS BRIEFLY TOUCHED UPON
EARLIER...WARMEST CONDITIONS DURING THE LONGER TERM SHOULD BE
NOTED BY NEXT MONDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 318 PM MDT MON APR 20 2015
VFR CONDITIONS ARE ANTICIPATED DURING THE NEXT 24H AT ALL 3 TAF
SITES...KPUB...KALS AND KCOS. VERY ISOLD TSRA WILL BE POSSIBLE THIS
EVENING AND TOMORROW EVENING AT KCOS AND KPUB. WINDS WILL BE
DIURNALLY DRIVEN AND WILL BE LIGHT.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...MOZLEY
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1252 AM MDT SUN APR 19 2015
.UPDATE...
ISSUED AT 1250 AM MDT SUN APR 19 2015
UPDATED TO REMOVE EXPIRED WINTER WEATHER HEADLINES. SIGNIFICANT
SNOWFALL HAS ENDED IN THE NORTHERN AND CENTRAL MTS OF CO AND ONLY
LIGHT ADDITIONAL ACCUMULATIONS AREA EXPECTED.
UPDATE ISSUED AT 744 PM MDT SAT APR 18 2015
UPPER LOW CONTINUES TO ROTATE IN PLACE OVER THE EASTERN PLAINS
THIS EVENING. WRAP AROUND MOISTURE KEEPING SNOW GOING IN THE HIGH
COUNTRY...A MIXTURE ACROSS THE MESA AND PLATEAU REGION AND
THUNDERSTORMS ACROSS EASTERN UTAH. STEEP LAPSE RATES DUE TO
HEATING OUTSIDE OF THE THICKER CLOUD SHIELD IS AIDING THE WEAK
WAVE DROPPING THROUGH EASTERN UTAH. STORMS STARTED OUT QUITE
ROBUST WEST OF THE COLORADO RIVER...BUT AS THEY TRAVEL SOUTHEAST
ACROSS THE INSTABILITY GRADIENT...THEY WEAKEN OVER OUR CWA. WILL
LOSS OF HEATING EXPECT THE COVERAGE TO SLOWLY WANE OVER THE NEXT
HOUR OR SO. WILL BE WATCHING THE AFFECT OF NIGHTFALL ON EASTERN
PASSES AS MELTING HAS KEPT ROADS IN DECENT SHAPE. MAY KEEP SOME
OF THE HEADLINES ALONG DIVIDE IF NECESSARY PAST MIDNIGHT. LASTLY
DEW POINTS DID CREEP UP A BIT THIS AFTERNOON INTO THE 40S OVER THE
WESTERN VALLEYS. WILL BE MONITORING THE THREAT OF DENSE FOG
AS WELL.
&&
.SHORT TERM...(TONIGHT THROUGH SUNDAY NIGHT)
ISSUED AT 325 PM MDT SAT APR 18 2015
THE LOW PRESSURE RESPONSIBLE FOR THE MUCH NEEDED PRECIP OVER THE
LAST FEW DAYS IS NOW LOCATED OVER THE FRONT PLAINS WHILE CYCLONIC
FLOW CONTINUES TO PUMP IN MOISTURE FROM THE NORTH TO SOUTH. THIS
FLOW STARTS IN NERN WY AND THE PLUME REACHES AS FAR SOUTH AS THE
SAN JUANS. SNOW AND RAIN HAS FALLEN MUCH OF THE DAY UNDER THIS
PLUME OF MOISTURE AND WILL CONTINUE TO DO SO THROUGH THIS EVENING.
CURRENT WINTER HIGHLIGHTS LOOK GOOD SO NO CHANGES THERE. AN UPPER
LEVEL DISTURBANCE OVER SRN CANADA IS TRAILING A TROUGH THAT IS
CAUSING THE AREA OF LOW PRESSURE TO KEEP MOVING EWRD. THE REASON
THIS IS HAPPENING SO SLOWLY IS THE LACK OF ANY STRONG JET FEATURES
TO REALLY GET THIS SYSTEM MOVING. EVEN SO...THE CLOUD SHIELD/PLUME
WILL BRING MORE PRECIP TO THE AREA AS THE ATTENDANT LOW PRESSURE
MEANDERS EAST. BY MIDNIGHT...PRECIP WILL FAVOR THE NRN AND CENTRAL
MTNS ALONG WITH THE FLATTOPS DUE TO THEIR FAVORABLE LOCATION SO
ADDITIONAL ACCUMULATIONS STILL POSSIBLE UP THERE. THE REST OF THE
CWA MAY SEE AN ODD SHOWER OR TWO BUT NOTHING TOO SIGNIFICANT.
BY SUNDAY...THE CANADIAN LOW WILL BE JUST TO THE NORTH OF
MINNESOTA WHILE HIGH PRESSURE BUILDS INTO THE PACNW. THIS WILL
CAUSE OUR CWA TO BE SANDWICHED BETWEEN THESE TWO FEATURES. WEAK
PIECES OF ENERGY WILL DROP DOWN FROM THE NW POSSIBLY CAUSING SOME
PRECIP FOR THE CWA. THE GFS HIGHLIGHTING TWO DISTINCT WAVES...ONE
SUNDAY EVENING AND ANOTHER MONDAY MORNING. THE NAM12 ONLY SHOWING
SOME SPOTTY SHOWERS AT BEST WITH SOME CONVECTION THROWN IN. THE
HRRR AND RAP SHOWING MUCH LESS IN THE WAY OF PRECIP. THIS ALL
MEANS UNSETTLED WX WILL CONTINUE BUT WITH MUCH MORE DEFINITIVE
BREAKS BETWEEN DISTURBANCES. FORECAST BRINGS MOSTLY BENIGN
WEATHER SUNDAY WITH INCREASING CHANCES FOR PRECIP FROM
MIDAFTERNOON ONWARDS...MAINLY FAVORING THE CONTINENTAL DIVIDE.
TEMPS WILL WARM UP CONSIDERABLY TOMORROW THOUGH STILL REMAIN 5 TO
10 DEGREES BELOW NORMAL.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 325 PM MDT SAT APR 18 2015
UNSETTLED NW FLOW IS EXPECTED MONDAY AND TUESDAY. AN EMBEDDED WAVE
SHOULD FOCUS THE BEST CHANCE OF SHOWERS OVER THE NORTHERN AND
CENTRAL MOUNTAINS MONDAY AFTERNOON AND EVENING. DAYTIME INSTABILITY
WILL KEEP ISOLATED TO SCATTERED SHOWERS OVER THE MTNS ON TUESDAY.
TEMPORARY RIDGING DEVELOPS OVER THE AREA BY MIDWEEK AS A TROUGH
FORMS ALONG THE WEST COAST...WITH AN UPPER LOW OVER SRN CA BY THU
MORNING. ENOUGH RESIDUAL MOISTURE LINGERS FOR A FEW AFTERNOON
SHOWERS OR THUNDERSTORMS. FLOW ALOFT BECOMES SOUTHWEST...AND THE
SRN CA LIFTS ACROSS THE FOUR CORNERS/DESERT SOUTHWEST THU NIGHT
AND FRI MORNING. TIMING AND TRACK A BIT DIFFERENT BETWEEN MODELS
BUT STILL LOOKING LIKE A BETTER CHANCE OF PRECIPITATION WITH SOME
THUNDERSTORMS LATE NEXT WEEK. BOOSTED POPS FOR THU AFTERNOON
THROUGH FRI OVER THE BLENDED FORECAST GUIDANCE AS A RESULT.
GFS AND ECMWF SOLUTIONS CONTINUE TO DIVERGE ON SATURDAY. ECMWF MORE
AMPLIFIED AS IT DIGS A PAC NW TROUGH TO THE SRN GREAT BASIN BY
SATURDAY...RESULTING IN DOWNSTREAM RIDGING AND SW FLOW OVER OUR
AREA. GFS DROPS SOME ENERGY FROM THE PAC NW TROUGH DOWN THE WEST
COAST BUT SENDS MORE OF IT ACROSS THE NRN ROCKIES WITH WESTERLY
FLOW ACROSS UT/CO. WILL FOLLOW THE BLENDED GUIDANCE FOR SAT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1040 PM MDT SAT APR 18 2015
A HIGH LATITUDE SYSTEM DIVING INTO THE NORTHERN PLAINS WILL BE
KICKING THIS STORM SYSTEM THAT HAS BEEN PARKED OVER COLORADO THE
PAST SEVERAL DAYS. THIS WILL ALLOW PRECIPITATION COVERAGE TO TREND
DOWNWARD OVER MOST OF WESTERN COLORADO AND EASTERN UTAH. THE HIGH
DIVIDE MOUNTAINS WILL THE MOST LIKELY AREA TO KEEP COLLECTING
LIGHT SNOW OVERNIGHT AND BE UNDER OBSCURATION. THE BIG CHALLENGE
INTO MID MORNING SUNDAY WILL BE LOW CLOUDS AND FOG DUE TO A MOIST
NEAR SURFACE LAYER FROM RECENT PRECIPITATION. THERE IS ALREADY A
HINT OF THIS AT KRIL...KASE AND KMTJ LATE THIS EVENING AS CLOUD
COVER ALOFT HAS THINNED. ANTICIPATE THIS WILL BECOME MORE OF A
WIDESPREAD PROBLEM THROUGH THE NIGHT BRINGING IFR/LIFR TO MANY
VALLEYS INCLUDING THE COLORADO TAF SITES. IMPROVEMENT SHOULD BE
QUICKER SUNDAY MORNING WITH MORE SUNSHINE AVAILABLE TO BURN OFF
THE LOW LEVEL MOISTURE.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
UPDATE...CC
SHORT TERM...TGR
LONG TERM...JAD
AVIATION...TGJT
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1040 PM MDT SAT APR 18 2015
.UPDATE...
ISSUED AT 744 PM MDT SAT APR 18 2015
UPPER LOW CONTINUES TO ROTATE IN PLACE OVER THE EASTERN PLAINS
THIS EVENING. WRAP AROUND MOISTURE KEEPING SNOW GOING IN THE HIGH
COUNTRY...A MIXTURE ACROSS THE MESA AND PLATEAU REGION AND
THUNDERSTORMS ACROSS EASTERN UTAH. STEEP LAPSE RATES DUE TO
HEATING OUTSIDE OF THE THICKER CLOUD SHIELD IS AIDING THE WEAK
WAVE DROPPING THROUGH EASTERN UTAH. STORMS STARTED OUT QUITE
ROBUST WEST OF THE COLORADO RIVER...BUT AS THEY TRAVEL SOUTHEAST
ACROSS THE INSTABILITY GRADIENT...THEY WEAKEN OVER OUR CWA. WILL
LOSS OF HEATING EXPECT THE COVERAGE TO SLOWLY WANE OVER THE NEXT
HOUR OR SO. WILL BE WATCHING THE AFFECT OF NIGHTFALL ON EASTERN
PASSES AS MELTING HAS KEPT ROADS IN DECENT SHAPE. MAY KEEP SOME
OF THE HEADLINES ALONG DIVIDE IF NECESSARY PAST MIDNIGHT. LASTLY
DEW POINTS DID CREEP UP A BIT THIS AFTERNOON INTO THE 40S OVER THE
WESTERN VALLEYS. WILL BE MONITORING THE THREAT OF DENSE FOG
AS WELL.
&&
.SHORT TERM...(TONIGHT THROUGH SUNDAY NIGHT)
ISSUED AT 325 PM MDT SAT APR 18 2015
THE LOW PRESSURE RESPONSIBLE FOR THE MUCH NEEDED PRECIP OVER THE
LAST FEW DAYS IS NOW LOCATED OVER THE FRONT PLAINS WHILE CYCLONIC
FLOW CONTINUES TO PUMP IN MOISTURE FROM THE NORTH TO SOUTH. THIS
FLOW STARTS IN NERN WY AND THE PLUME REACHES AS FAR SOUTH AS THE
SAN JUANS. SNOW AND RAIN HAS FALLEN MUCH OF THE DAY UNDER THIS
PLUME OF MOISTURE AND WILL CONTINUE TO DO SO THROUGH THIS EVENING.
CURRENT WINTER HIGHLIGHTS LOOK GOOD SO NO CHANGES THERE. AN UPPER
LEVEL DISTURBANCE OVER SRN CANADA IS TRAILING A TROUGH THAT IS
CAUSING THE AREA OF LOW PRESSURE TO KEEP MOVING EWRD. THE REASON
THIS IS HAPPENING SO SLOWLY IS THE LACK OF ANY STRONG JET FEATURES
TO REALLY GET THIS SYSTEM MOVING. EVEN SO...THE CLOUD SHIELD/PLUME
WILL BRING MORE PRECIP TO THE AREA AS THE ATTENDANT LOW PRESSURE
MEANDERS EAST. BY MIDNIGHT...PRECIP WILL FAVOR THE NRN AND CENTRAL
MTNS ALONG WITH THE FLATTOPS DUE TO THEIR FAVORABLE LOCATION SO
ADDITIONAL ACCUMULATIONS STILL POSSIBLE UP THERE. THE REST OF THE
CWA MAY SEE AN ODD SHOWER OR TWO BUT NOTHING TOO SIGNIFICANT.
BY SUNDAY...THE CANADIAN LOW WILL BE JUST TO THE NORTH OF
MINNESOTA WHILE HIGH PRESSURE BUILDS INTO THE PACNW. THIS WILL
CAUSE OUR CWA TO BE SANDWICHED BETWEEN THESE TWO FEATURES. WEAK
PIECES OF ENERGY WILL DROP DOWN FROM THE NW POSSIBLY CAUSING SOME
PRECIP FOR THE CWA. THE GFS HIGHLIGHTING TWO DISTINCT WAVES...ONE
SUNDAY EVENING AND ANOTHER MONDAY MORNING. THE NAM12 ONLY SHOWING
SOME SPOTTY SHOWERS AT BEST WITH SOME CONVECTION THROWN IN. THE
HRRR AND RAP SHOWING MUCH LESS IN THE WAY OF PRECIP. THIS ALL
MEANS UNSETTLED WX WILL CONTINUE BUT WITH MUCH MORE DEFINITIVE
BREAKS BETWEEN DISTURBANCES. FORECAST BRINGS MOSTLY BENIGN
WEATHER SUNDAY WITH INCREASING CHANCES FOR PRECIP FROM
MIDAFTERNOON ONWARDS...MAINLY FAVORING THE CONTINENTAL DIVIDE.
TEMPS WILL WARM UP CONSIDERABLY TOMORROW THOUGH STILL REMAIN 5 TO
10 DEGREES BELOW NORMAL.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 325 PM MDT SAT APR 18 2015
UNSETTLED NW FLOW IS EXPECTED MONDAY AND TUESDAY. AN EMBEDDED WAVE
SHOULD FOCUS THE BEST CHANCE OF SHOWERS OVER THE NORTHERN AND
CENTRAL MOUNTAINS MONDAY AFTERNOON AND EVENING. DAYTIME INSTABILITY
WILL KEEP ISOLATED TO SCATTERED SHOWERS OVER THE MTNS ON TUESDAY.
TEMPORARY RIDGING DEVELOPS OVER THE AREA BY MIDWEEK AS A TROUGH
FORMS ALONG THE WEST COAST...WITH AN UPPER LOW OVER SRN CA BY THU
MORNING. ENOUGH RESIDUAL MOISTURE LINGERS FOR A FEW AFTERNOON
SHOWERS OR THUNDERSTORMS. FLOW ALOFT BECOMES SOUTHWEST...AND THE
SRN CA LIFTS ACROSS THE FOUR CORNERS/DESERT SOUTHWEST THU NIGHT
AND FRI MORNING. TIMING AND TRACK A BIT DIFFERENT BETWEEN MODELS
BUT STILL LOOKING LIKE A BETTER CHANCE OF PRECIPITATION WITH SOME
THUNDERSTORMS LATE NEXT WEEK. BOOSTED POPS FOR THU AFTERNOON
THROUGH FRI OVER THE BLENDED FORECAST GUIDANCE AS A RESULT.
GFS AND ECMWF SOLUTIONS CONTINUE TO DIVERGE ON SATURDAY. ECMWF MORE
AMPLIFIED AS IT DIGS A PAC NW TROUGH TO THE SRN GREAT BASIN BY
SATURDAY...RESULTING IN DOWNSTREAM RIDGING AND SW FLOW OVER OUR
AREA. GFS DROPS SOME ENERGY FROM THE PAC NW TROUGH DOWN THE WEST
COAST BUT SENDS MORE OF IT ACROSS THE NRN ROCKIES WITH WESTERLY
FLOW ACROSS UT/CO. WILL FOLLOW THE BLENDED GUIDANCE FOR SAT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1040 PM MDT SAT APR 18 2015
A HIGH LATITUDE SYSTEM DIVING INTO THE NORTHERN PLAINS WILL BE
KICKING THIS STORM SYSTEM THAT HAS BEEN PARKED OVER COLORADO THE
PAST SEVERAL DAYS. THIS WILL ALLOW PRECIPITATION COVERAGE TO TREND
DOWNWARD OVER MOST OF WESTERN COLORADO AND EASTERN UTAH. THE HIGH
DIVIDE MOUNTAINS WILL THE MOST LIKELY AREA TO KEEP COLLECTING
LIGHT SNOW OVERNIGHT AND BE UNDER OBSCURATION. THE BIG CHALLENGE
INTO MID MORNING SUNDAY WILL BE LOW CLOUDS AND FOG DUE TO A MOIST
NEAR SURFACE LAYER FROM RECENT PRECIPITATION. THERE IS ALREADY A
HINT OF THIS AT KRIL...KASE AND KMTJ LATE THIS EVENING AS CLOUD
COVER ALOFT HAS THINNED. ANTICIPATE THIS WILL BECOME MORE OF A
WIDESPREAD PROBLEM THROUGH THE NIGHT BRINGING IFR/LIFR TO MANY
VALLEYS INCLUDING THE COLORADO TAF SITES. IMPROVEMENT SHOULD BE
QUICKER SUNDAY MORNING WITH MORE SUNSHINE AVAILABLE TO BURN OFF
THE LOW LEVEL MOISTURE.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER STORM WARNING UNTIL MIDNIGHT MDT TONIGHT FOR COZ009-010-
012-017-018.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT MDT TONIGHT FOR COZ003-
004-013.
UT...NONE.
&&
$$
UPDATE...15
SHORT TERM...TGR
LONG TERM...JAD
AVIATION...TGJT
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1039 PM EDT MON APR 20 2015
.SYNOPSIS...
A WIND SWEPT SOAKING RAIN IS EXPECTED THROUGH THIS EVENING...WITH
EVEN A FEW THUNDERSTORMS POSSIBLE TONIGHT. SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS ALONG WITH MILD TEMPS TUESDAY MORNING GIVES
WAY TO A DRYING TREND DURING THE AFTERNOON. A COLD FRONT WILL
BRING SCATTERED SHOWERS AND PERHAPS EVEN AN ISOLATED THUNDERSTORM
OR TWO WEDNESDAY AFTERNOON AND EVENING. UNSEASONABLY COOL WEATHER
FOLLOWS THURSDAY THROUGH THIS WEEKEND WITH JUST A SPOT SHOWER FROM
TIME TO TIME.
&&
.NEAR TERM /UNTIL MIDNIGHT TONIGHT/...
1030 PM UPDATE...
NO MAJOR CHANGES TO ONGOING FORECAST THIS EVENING. DID TWEAK THE
NEXT SEVERAL HOURS TO REFLECT THE LATEST OBSERVED TRENDS.
THE MAIN CONCERN OVERNIGHT REMAINS THE POTENTIAL FOR CONVECTION.
LATEST RUNS OF THE HRRR REMAIN BULLISH ON PRE-DAWN THUNDERSTORM
POTENTIAL ACROSS RI AND SOUTHEAST MA...INCLUDING THE CAPE AND
ISLANDS. WILL NEED TO CONTINUE TO MONITOR PROGRESS OF THUNDERSTORM
CLUSTER OVER PA/NY THIS EVENING...SINCE THIS IS WHERE THE ENERGY
WILL COME FROM. NOT EXPECTING SEVERE WEATHER AT THIS TIME. HEAVY
RAINFALL IS NOT OUT OF THE QUESTION THOUGH. DEPENDING ON WHERE
THIS HAPPENS...AND HOW FAST...WE COULD SEE SOME FLOODING ISSUES
LATE TONIGHT. MAINLY EXPECTING NUISANCE FLOODING...BUT COULD BE
MORE IF THE HEAVY RAINFALL OCCURS WITHIN SOME URBAN AREAS...SUCH
AS FALL RIVER AND NEW BEDFORD.
PREVIOUS DISCUSSION...
THESE HEAVIER SHOWERS WERE BLOSSOMING ON THE NOSE OF THE LOW LEVEL
JET/DRY SLOT ALLOWING FOR INCREASED INSTABILITY. GIVEN SHOWALTER
INDICES DROPPING BELOW ZERO AND SOME ELEVATED CAPE...A FEW EMBEDDED
THUNDERSTORMS ARE POSSIBLE THIS EVENING. WE PROBABLY WILL SEE A BIT
OF A LULL IN THE ACTIVITY SOMETIME LATER THIS EVENING UNTIL THE NEXT
BATCH OF ACTIVITY DEVELOPING ACROSS THE EASTERN GREAT LAKES/MID
ATLANTIC TRACKS NORTHEAST. WHILE SEVERE WEATHER IS NOT
EXPECTED...THIS MAY POSE A HIGHER RISK OF SCATTERED THUNDERSTORMS
WITH HEAVY RAINFALL TOWARD DAYBREAK. THIS IS DISCUSSED FURTHER IN
THE NEXT SECTION.
FINALLY...AREAS OF FOG MAY BECOME LOCALLY DENSE. BEST CHANCE FOR
THIS WILL BE LATER THIS EVENING WHEN WILL LIKELY SEE A LULL IN THE
ACTIVITY AND WINDS DIMINISH A BIT. CONFIDENCE AND AREAL COVERAGE
NOT HIGH ENOUGH TO ISSUE A DENSE FOG ADVISORY...BUT LATER SHIFTS
WILL HAVE TO MONITOR.
&&
.SHORT TERM /MIDNIGHT THROUGH 6 PM TUESDAY/...
OVERNIGHT...THE WARM FRONT WILL MOVE NORTH OVER SOUTHERN NEW ENGLAND
AND THE SOUTHERN PARTS OF THE AREA LOOK TO WARM SECTOR DURING THE
EARLY MORNING HOURS. THIS WOULD INCLUDE RHODE ISLAND...SOUTHEASTERN
MASSACHUSETTS...AND POSSIBLY PORTIONS OF NORTHERN CONNECTICUT. THIS
WILL NOT ONLY BRING TEMPERATURES UP THROUGH THE NIGHT...BUT WILL
ALSO ALLOW THE ATMOSPHERE TO FURTHER DESTABILIZE.
K INDICES INCREASE AND SHOWALTER INDICES DECREASE AND ALONG WITH THE
TOTAL TOTALS IN THE 50S THIS WILL RESULT IN SOME SURFACE BASED
INSTABILITY ALONG WITH THE ELEVATED INSTABILITY ALREADY IN PLACE.
THIS WILL PROVIDE A BETTER CHANCE OF THUNDER EARLY TUESDAY MORNING
AS THE SHORTWAVE AND ATTENDANT COLD FRONT MOVE THROUGH THE REGION.
EXPECT RAPID CLEARING BEHIND THE FRONT WITH TEMPERATURES SOARING
INTO THE UPPER 60S TO NEAR 70 MOST LOCATIONS. WESTERLY WINDS WILL
ALLOW EVEN THE COASTAL LOCATIONS TO GET IN ON THE WARM
TEMPERATURES...UNLIKE SATURDAY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
HIGHLIGHTS...
* SCATTERED SHOWERS WED WITH A LOW RISK OF THUNDER/SMALL HAIL
* SEASONABLY MILD TEMPERATURES WED
* UNSEASONABLY COOL THU-SUN WITH A SPOT SHOWER OR TWO AT TIMES
DETAILS...
TUESDAY NIGHT...
A SHORTWAVE WILL BE APPROACHING FROM THE WEST TUE NIGHT. MODELS DO
NOT SHOW MUCH QPF AS INSTABILITY IS RATHER LIMITED. MAY SEE A FEW
SPOT SHOWERS ESPECIALLY NORTH OF THE MA PIKE...BUT MUCH OF THE
NIGHT SHOULD FEATURE DRY WEATHER IN A GIVEN LOCATION.
LOW TEMPS WILL BOTTOM OUT IN THE 30S TO THE LOWER 40S.
WEDNESDAY AND WEDNESDAY NIGHT...
A FAIRLY STRONG SHORTWAVE AND ASSOCIATED COLD FRONT WILL CROSS THE
REGION WED AFTERNOON AND EVENING. HIGH TEMPS SHOULD STILL REACH
INTO INTO THE UPPER 50S TO MIDDLE 60S AHEAD OF THE FRONT. WE WILL
SEE SCATTERED SHOWERS WITH THE FRONT GIVEN DECENT FORCING AND SOME
MARGINAL INSTABILITY. MOST LIKELY TIME FRAME IS WED AFTERNOON AND
EARLY EVENING. ITS QUITE COLD ALOFT AND MID LEVEL LAPSE RATES ARE
VERY IMPRESSIVE AROUND 8C/KM! IF WE CAN MUSTER A FEW HUNDRED J/KG
OF CAPE...MAY EVEN SEE AN EMBEDDED THUNDERSTORM OR TWO. CONFIDENCE
ON THUNDER IS LOW AT THIS POINT...BUT GIVEN COLD POOL ALOFT THERE IS
AT LEAST THIS RISK FOR SOME GRAUPEL/SMALL HAIL AND PERHAPS EVEN
GUSTY WINDS IN THE HEAVIEST SHOWERS. THIS ACTIVITY SHOULD WIND DOWN
BY WED EVENING.
THURSDAY THROUGH MONDAY...
ANOMALOUS CLOSED UPPER LEVEL LOW SETS UP ACROSS NORTHERN NEW ENGLAND
AND INTO QUEBEC. THE RESULT WILL BE BELOW NORMAL HEIGHTS AND COOLER
THAN NORMAL TEMPS IN SOUTHERN NEW ENGLAND. OVERALL...HIGH TEMPS
WILL RANGE FROM THE UPPER 40S TO MIDDLE 50S MUCH OF THE TIME BUT
SOME MODERATION IS POSSIBLE BY MONDAY. AS FOR PRECIP CHANCES...THE
VAST MAJORITY OF THE TIME SHOULD FEATURE DRY WEATHER.
HOWEVER...GIVEN COLD POOL ALOFT A FEW SPOT SHOWERS WILL BE POSSIBLE
AT TIMES...ESPECIALLY IN NORTHERN SECTIONS DURING THE AFTERNOON
HOURS. LOW RISK FOR EVEN A FEW WET SNOW FLAKES TO MIX IN FOR
A TIME ACROSS THE HIGHER TERRAIN...BUT WOULD BE OF NO IMPACT.
THERE IS ONE FLY IN THE OINTMENT. WE WILL HAVE TO WATCH A MORE
SIGNIFICANT LOW PRESSURE SYSTEM SAT NIGHT/SUN. MOST OF THE MODEL
GUIDANCE KEEPS THAT SYSTEM WELL TO OUR SOUTH. THE 12Z ECMWF IS A
BIT CLOSER THEN THE REST OF THE GUIDANCE...BUT EVEN THAT WOULD KEEP
US DRY. AGAIN...ODDS STRONGLY FAVOR KEEPING THIS SYSTEM SOUTH OR
OUR REGION GIVEN ANOMALOUS CLOSED LOW SITTING JUST TO OUR NORTH.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
.SHORT-TERM /THROUGH TUESDAY/...
TONIGHT...IFR TO LIFR CONDITIONS CONTINUE. NUMEROUS SHOWERS WITH
HEAVY RAINFALL EXPECTED. LULL FROM RAINFALL LIKELY SHORTLY AFTER
MIDNIGHT...WHERE SOME LOCALLY DENSE FOG IS POSSIBLE. ANOTHER
BATCH OF SHOWERS WITH A HIGHER RISK OF THUNDERSTORMS MOVES IN
TOWARD DAYBREAK. E/SE-WINDS DIMINISHING. LLWS LIKELY INTO EARLY
TUESDAY MORNING.
TUESDAY...CONDITIONS IMPROVING TO VFR BY MIDDAY. COLD FRONT
MOVES THROUGH WITH WINDS SHIFTING W/SW.
KBOS TAF...MODERATE CONFIDENCE. CONCERNED ABOUT A PERIOD OF ONE HALF
MILE OR LESS VISIBILITY OVERNIGHT BUT TIMING UNCERTAIN. IT MIGHT
AFFECT THE MORNING PUSH. ALSO LOW RISK OF A THUNDERSTORM BETWEEN 8
AND 12Z.
KBDL TAF...MODERATE CONFIDENCE. CONCERNED ABOUT A PERIOD OF ONE
HALF MILE OR LESS VISIBILITY OVERNIGHT BUT TIMING UNCERTAIN. LOW
RISK OF AN ISOLATED THUNDERSTORM
OUTLOOK...TUESDAY NIGHT THROUGH SATURDAY...
TUE NIGHT...HIGH CONFIDENCE IN MAINLY VFR CONDITIONS DESPITE THE
RISK FOR A SPOT SHOWER OR TWO.
WED...MODERATE CONFIDENCE. A COLD FRONT WILL BRING A ROUND OF
SCATTERED SHOWERS MAINLY WED AFTERNOON/EARLY EVENING. LOW RISK FOR
EVEN A FEW RUMBLES OF THUNDER AND PERHAPS SMALL HAIL/GRAUPEL WITH
THE HEAVIEST SHOWERS.
THU/FRI/SAT...HIGH CONFIDENCE. MAINLY VFR DESPITE THE RISK FOR A
BRIEF DIURNALLY DRIVEN SHOWER OR TWO.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH TUESDAY/...
HIGH CONFIDENCE. GALE WARNINGS REMAIN IN PLACE FOR ALL THE WATERS
OUTSIDE BOSTON HARBOR AND NARRAGANSETT BAY. CURRENT PLAN IS TO
REPLACE SOME OF THE GALE WARNINGS WITH SMALL CRAFT ADVISORIES
TOWARD MIDNIGHT...WHICH IS RIGHT ON SCHEDULE WITH PREVIOUS
FORECAST. THIS IS FOR WIND GUSTS UP TO 35 KTS THROUGH THIS
EVENING AND INTO THE NIGHT FOR THE OUTER WATERS.
RAIN EXPECTED TO CONTINUE WITH STEADY RAIN COMING TO AN END LATE
THIS EVENING AND TURNING MORE SHOWERY THROUGH MIDDAY TUESDAY. A FEW
ISOLATED RUMBLES OF THUNDER ARE POSSIBLE THIS EVENING...WITH A
BETTER CHANCE EARLY TUESDAY MORNING. VISIBILITIES MAY BE LIMITED AT
TIMES.
OUTLOOK...TUESDAY NIGHT THROUGH SATURDAY...
TUESDAY NIGHT AND WEDNESDAY...HIGH CONFIDENCE. MODEST WEST TO
SOUTHWEST FLOW EXPECTED AHEAD OF A COLD FRONT...BUT SPEEDS SHOULD
REMAIN BELOW SMALL CRAFT THRESHOLDS. A FEW SHOWERS WED AFTERNOON
AND EVENING WITH A LOW RISK OF AN ISOLATED THUNDERSTORM WITH SMALL
HAIL.
THURSDAY THROUGH SATURDAY...HIGH CONFIDENCE. MODEST WESTERLY FLOW AS
A RESULT OF CLOSED LOW PRESSURE ACROSS QUEBEC. ENOUGH COLD
ADVECTION OVER THE WATERS WILL BE PRESENT TO GENERATE PERIODS OF 25
KNOT WIND GUSTS. MARGINAL SCA SEAS EXPECTED ACROSS THE OUTER-WATERS
AT TIMES...BUT WITH GOOD VISIBILITY.
&&
.TIDES/COASTAL FLOODING...
EAST TO SOUTHEAST WINDS WILL INCREASE THROUGH TONIGHT. GUIDANCE
CONTINUES TO TRACK STRONGEST WINDS ACROSS NEW ENGLAND EARLY THIS
EVENING...BEFORE HIGH TIDE OCCURS ALONG THE SOUTH COAST /AROUND
03Z/ AND EAST COAST /ABOUT 06Z/. THIS RESULTS IN WINDS BEGINNING
TO SLACKEN AS HIGH TIDE APPROACHES. ALSO SYSTEM IS FAIRLY
PROGRESSIVE SO DURATION OF ONSHORE WINDS IS LIMITED.
ESTOFS CONTINUES TO BE MORE ROBUST AND REALISTIC THAN ETSS WITH
SURGE VALUES 1.0-1.5 FT AT THE TIME OF HIGH TIDE. SEAS ALSO BUILDING
TO 10-15 FT JUST OFFSHORE. THIS SHOULD BE SUFFICIENT TO GENERATE
AREAS OF MINOR COASTAL FLOODING AND SPLASH OVER. THUS WILL CONTINUE
WITH A COASTAL FLOOD ADVISORY FOR THESE LOCATIONS DURING THIS
EVENING AND EARLY TUE MORNING HIGH TIDES.
WINDS DO NOT LOOK STRONG ENOUGH AT THE TIME OF HIGH TIDE FOR A
MODERATE COASTAL FLOOD EVENT.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...COASTAL FLOOD ADVISORY UNTIL 4 AM EDT TUESDAY FOR MAZ007-015-
016-019-022-024.
COASTAL FLOOD ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR MAZ020-
021.
RI...COASTAL FLOOD ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR RIZ002-
004>007.
MARINE...GALE WARNING UNTIL MIDNIGHT EDT TONIGHT FOR ANZ231>235-237-251.
SMALL CRAFT ADVISORY UNTIL 4 AM EDT TUESDAY FOR ANZ230-236.
GALE WARNING UNTIL 4 AM EDT TUESDAY FOR ANZ250-254>256.
&&
$$
SYNOPSIS...FRANK/RLG
NEAR TERM...BELK/FRANK
SHORT TERM...RLG
LONG TERM...FRANK
AVIATION...BELK/FRANK/RLG
MARINE...BELK/FRANK/RLG
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS ALBANY NY
1000 PM EDT MON APR 20 2015
.SYNOPSIS...
.A LOW PRESSURE SYSTEM APPROACHING FROM THE WEST WITH ASSOCIATED
FRONTS WILL BRING OCCASIONAL SHOWERS TO THE AREA ALONG WITH A FEW
RUMBLES OF THUNDER TONIGHT. WITH A LARGE STATIONARY LOW OVER THE
REGION...UNSETTLED WEATHER WILL CONTINUE THROUGH THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
THE WIND ADVISORY HAS BEEN CANCELED FOR THE HIGHER ELEVATIONS OF
THE NORTH AND CENTRAL TACONICS...BERKSHIRES AND FOR BENNINGTON AND
WESTERN WINDHAM COUNTIES. THE WINDS HAVE WEAKENED HOWEVER THEY
DO REMAIN BRISK AND GUSTY IN THE WINDS HAVE WEAKENED HOWEVER THEY DO REMAIN BRISK AND GUSTY IN
SOME LOCATIONS.SOME LOCATIONS.
AS OF 945 PM...HAVE HAD A BIT OF A LULL IN THE PRECIPITATION THIS
EVENING. HAVE SHOWERS ACTIVITY OCCURRING TO EAST AND CONVECTION TO
OUR WEST IN THE VICINITY OF THE WARM FRONT. HAVE ADJUSTED POPS TO
BETTER REFLECT CURRENT ACTIVITY. THE HRRR SEEMS TO HAVE A PRETTY
GOOD HANDLE ON CONVECTION SO HAVE USED IT AS A GUIDE TO INCREASE
POPS THIS EVENING AS ANOTHER DISTURBANCE AHEAD AN OCCLUDING
FRONTAL BOUNDARY INCREASES THE THREAT FOR CONVECTION.
THE SYSTEM WILL OCCLUDE AS IT MOVES EASTWARD. WE ARE NOT EXPECTED
TO GET INTO THE WARM SECTOR IT GETS PINCHED OFF JUST TO THE SOUTH
OF OUR FORECAST AREA TONIGHT AS THE SYSTEM OCCLUDES. MODELS
CONTINUE TO SHOW SOME ELEVATED INSTABILITY WITH SHOWALTER INDICES
BELOW ZERO MOVING ACROSS THE REGION TONIGHT...SO HAVE KEEP MENTION
OF THUNDER IN THE FORECAST. ANY THUNDERSTORMS THAT OCCUR COULD
HAVE LOCALLY HEAVY DOWNPOURS...ESPECIALLY GIVEN THE STRONG THETA-E
RIDGE WHICH DEVELOPS ACROSS THE REGION OVERNIGHT.
TEMPERATURE TRENDS SINCE THE LAST UPDATE UNDER CLOUDY SKIES HAVE
DROPPED SLOWLY WITH LOWS EXPECTED TO BE IN THE 40S.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
DURING THE DAY ON TUESDAY WE CAN EXPECT SOME LINGERING SHOWERS
DURING THE DAY WITH SOME BREAKS OF SUN POSSIBLE IN THE AFTERNOON.
THE UPPER LEVEL TROUGH AXIS WILL BE PASSING THROUGH THE AREA WITH
AN ASSOCIATED VORT MAX. HIGH TEMPS ON TUESDAY ARE EXPECTED MAX
TEMPS ARE FORECAST TO REACH THE LOWER/MID 60S IN VALLEY AREAS AND
50S ACROSS HIGHER ELEVATIONS.
FOR TUESDAY NIGHT AND WEDNESDAY...A SECONDARY TROUGH IS EXPECTED
TO MOVE FROM THE MIDWEST THROUGH CENTRAL NEW YORK AND CENTRAL
PENNSYLVANIA BRINGING ANOTHER ROUND OF SHOWERS AND THIS WILL BE
FOLLOWED BY YET ANOTHER TROUGH OF LOW PRESSURE ON WEDNESDAY. THIS
IS ALL OCCURRING AT THE SURFACE WHILE ALOFT AN UPPER LEVEL CLOSED
LOW SITS AND SPINS JUST NORTH OF THE UPPER GREAT LAKES SENDING
PIECES OF ENERGY IN THE FORM OF VORT LOBES ACROSS OUR FA DURING
MUCH OF THE PERIOD. EXPECT LOWS ON TUESDAY NIGHT ARE EXPECTED TO
RANGE FROM THE UPPER 20S NORTHWEST TO AROUND 40 SOUTHEAST. SOME
LIGHT SNOW ACCUMULATIONS GENERALLY UNDER AN INCH ARE POSSIBLE
ACROSS THE WESTERN ADIRONDACKS. HIGHS ON WEDNESDAY ARE EXPECTED TO
RANGE FROM THE UPPER 40S NORTHWEST TO AROUND 690 NORTHWEST.
FOR WEDNESDAY NIGHT AND THURSDAY NOT MUCH IMPROVEMENT IS EXPECTED
AS THE UPPER LEVEL TROUGH AXIS SETTLES ACROSS THE NORTHEAST US
WHILE AT THE SURFACE LOW PRESSURE INTENSIFIES ACROSS THE GULF OF
MAINE WITH YET ANOTHER COLD FRONT EXPECTED TO MOVE INTO THE
EASTERN GREAT LAKES BY THURSDAY. THUS THERE WILL STILL BE
SCATTERED SHOWERS AROUND ALTHOUGH THE PCPN SHOULD BE MAINLY ON THE
LIGHT SIDE. EXPECT LOWS WEDNESDAY NIGHT TO BE IN THE UPPER 20S TO
UPPER 30S WITH ONCE AGAIN A LITTLE LIGHT SNOW POSSIBLE ACROSS THE
WESTERN ADIRONDACKS WITH HIGHS ON THURSDAY IN THE MID 40S TO LOWER
50S.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
BELOW NORMAL TEMPERATURES ALONG WITH SOME INTERVALS OF RAIN AND
EVEN SNOW SHOWERS ARE EXPECTED THROUGH THE WEEKEND.
MODEL GUIDANCE REMAINS IN GOOD AGREEMENT INDICATING A LARGE SCALE UPPER
LOW WILL DOMINATE OUR WEATHER. HOWEVER THERE CONTINUES TO BE SOME
DISAGREEMENT ON ITS EXACT TRACK AND WITH THE TIMING OF INDIVIDUAL SHORT
WAVE ROTATING ABOUT IT. THERE IS CONSENSUS THE CENTER OF THE UPPER
LOW SHOULD REMAIN TO OUR NORTH AS IT MOVES ACROSS EASTERN CANADA KEEPING
OUR THE REGION IN WESTERLY FLOW. HAVE FAVORED GUIDANCE FROM THE WEATHER
PREDICTION CENTER TO MAINTAIN FORECAST CONSISTENCY. THE BETTER CHANCES
FOR SCATTERED SHOWERS WILL BE ACROSS THE HIGHER TERRAIN. RAIN SHOWERS
ARE EXPECTED DURING THE DAY...BUT AT NIGHT IT WILL BE COLD ENOUGH FOR
SNOW SHOWER ESPECIALLY ACROSS THE HIGHER ELEVATIONS.
OVERALL EXPECTING HIGHS IN THE 40S AND 50S WITH LOWS IN THE 20S AND 30S.
NORMALS FOR LATE APRIL...
ALBANY NY: HIGHS IN THE LOWER 60S AND LOWS IN THE LOWER 40S.
GLENS FALLS NY: HIGHS IN THE LOWER 60S AND LOWS IN THE UPPER 30S.
POUGHKEEPSIE NY: HIGHS IN THE MID 60S AND LOWS AROUND 40.
BENNINGTON VT: HIGHS IN THE LOWER 60S AND LOWS IN THE UPPER 30S.
PITTSFIELD MA: HIGHS IN THE UPPER 50S AND LOWS IN THE MID 30S.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
A LOW PRESSURE SYSTEM WILL OCCLUDE AS IT MOVES ACROSS THE REGION
TONIGHT. WE HAVE HAD A BIT OF A LULL IN THE PRECIPITATION THIS
EVENING. HAVE SHOWERS ACTIVITY OCCURRING TO EAST AND CONVECTION TO
OUR WEST IN THE VICINITY OF THE WARM FRONT. THE HRRR SEEMS TO HAVE
A PRETTY GOOD HANDLE ON CONVECTION SO HAVE USED IT AS A GUIDE TO
INCREASE POPS THIS EVENING WITH THE BEST CHANCES AS WE APPROACH
MIDNIGHT AS ANOTHER DISTURBANCE AHEAD THE OCCLUDING FRONTAL
BOUNDARY WILL INCREASE THE THREAT FOR CONVECTION. WE ARE NOT
EXPECTED TO GET INTO THE WARM SECTOR IT GETS PINCHED OFF JUST TO
THE SOUTH OF OUR FORECAST AREA TONIGHT AS THE SYSTEM OCCLUDES.
THE MODELS CONTINUE TO SHOW SOME ELEVATED INSTABILITY WITH
SHOWALTER INDICES BELOW ZERO MOVING ACROSS THE REGION TONIGHT...SO
THERE IS A CHANCE FOR THUNDERSTORMS HOWEVER CONFIDENCE IS TOO LOW
TO INCLUDE IN THE TAFS.
CONDITIONS WILL LOWER WITH WIDESPREAD MVFR-IFR DEVELOPING.
A GRADUAL IMPROVEMENT WILL OCCUR WITH THE PASSAGE OF THE OCCLUDED
FRONT. WITH WIDESPREAD VFR FOR THE AFTERNOON.
HAVE NORTHEAST TO SOUTHEAST FLOW ACROSS AREA. RECENT OBSERVATIONS
SHOWN A DIMINISHING TREND IN WIND GUSTS ACROSS THE BERKSHIRES...
TACONICS AND SOUTHERN VERMONT WHERE THE FLOW HAS BEEN ENHANCED BY
THE TERRAIN. WINDS WILL LIGHTEN AS THE OCCLUDED BOUNDARY MOVES
THOUGH WITH A SHIFT TO SOUTHWEST TO WEST WITH ITS PASSAGE.
WESTERLY WINDS WILL INCREASE TO 10 TO 15 KNOTS AND WILL BE GUSTY
ESPECIALLY AT KALB AND KPSF.
OUTLOOK...
TUE NIGHT-WED: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
WED NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA...SHSN.
THU: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
THU NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
FRI: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
FRI NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
SAT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
&&
.FIRE WEATHER...
THERE ARE NO FIRE WEATHER CONCERNS THIS WEEK AS WE WILL BE UNDER
THE INFLUENCE OF AN UPPER LEVEL TROUGH. A WIDESPREAD SOAKING
RAINFALL WILL OCCUR ACROSS THE AREA THROUGH TONIGHT...WITH
RAINFALL AMTS OF 0.75-1.5 INCHES EXPECTED. THE WEATHER WILL BE
COOL AND UNSETTLED FOR MUCH OF THE WEEK.
&&
.HYDROLOGY...
A WIDESPREAD SOAKING RAINFALL WILL OCCUR ACROSS THROUGH TONIGHT.
EXPECTING WIDESPREAD QPF AMOUNTS OF AROUND AN INCH WITH HIGHER
AMOUNTS UP TO AROUND 1.5 INCHES WHERE THE RAINFALL IS ENHANCED BY
THE STRONG EAST TO SOUTHEAST FLOW...PARTICULARLY ACROSS THE
CENTRAL AND SOUTHEASTERN CATSKILLS...TACONICS...BERKSHIRES INTO
THE LITCHFIELD HILLS AND ACROSS SOUTHERN VERMONT. LOCALIZED HIGHER
AMOUNTS OF 2 TO 3 INCHES WILL BE POSSIBLE.
THERE IS STILL SOME SNOW COVER LEFT IN THE FORECAST AREA. BASED
ON NATIONAL OPERATIONAL HYDROLOGIC REMOTE SENSING CENTER (NOHRSC)
THIS IS ACROSS THE PORTIONS OF THE WESTERN ADIRONDACKS AND ACROSS
THE HIGHER TERRAIN OF THE SOUTHERN GREEN MOUNTAINS.
BASED ON CURRENT FORECASTS...ONLY THE WEST CANADA CREEK AT
HINCKLEY DAM IS EXPECTED TO EXCEED ITS FLOOD STAGE BY TUESDAY
EVENING.
THE REST OF THE WEEK THE FORECAST WILL BE DOMINATED BY A PERSISTENT
UPPER LEVEL TROUGH WHICH WILL RESULT IN COOL TEMPERATURES...BREEZY
CONDITIONS AND OCCASIONAL CHANCES FOR MAINLY LIGHT PRECIPITATION.
FOR DETAILS ON SPECIFIC AREA RIVER AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEB-
SITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...IAA/KL/LFM/11/WASULA
NEAR TERM...IAA/LFM/11/WASULA
SHORT TERM...11
LONG TERM...IAA
AVIATION...IAA/WASULA
FIRE WEATHER...11
HYDROLOGY...IAA/KL/11
AREA FORECAST DISCUSSION
NWS ALBANY NY
947 PM EDT MON APR 20 2015
.SYNOPSIS...
.A LOW PRESSURE SYSTEM APPROACHING FROM THE WEST WITH ASSOCIATED
FRONTS WILL BRING OCCASIONAL SHOWERS TO THE AREA ALONG WITH A FEW
RUMBLES OF THUNDER TONIGHT. WITH A LARGE STATIONARY LOW OVER THE
REGION...UNSETTLED WEATHER WILL CONTINUE THROUGH THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
THE WIND ADVISORY REMAINS IN EFFECT UNTIL MIDNIGHT FOR THE HIGHER
ELEVATIONS OF THE NORTH AND CENTRAL TACONICS...BERKSHIRES AND FOR
BENNINGTON AND WESTERN WINDHAM COUNTIES. HOWEVER RECENT OBSERVATIONS
SHOWN A DIMINISHING TREND IN WIND GUSTS.
AS OF 945 PM...HAVE HAD A BIT OF A LULL IN THE PRECIPITATION THIS
EVENING. HAVE SHOWERS ACTIVITY OCCURRING TO EAST AND CONVECTION TO
OUR WEST IN THE VICINITY OF THE WARM FRONT. HAVE ADJUSTED POPS TO
BETTER REFLECT CURRENT ACTIVITY. THE HRRR SEEMS TO HAVE A PRETTY
GOOD HANDLE ON CONVECTION SO HAVE USED IT AS A GUIDE TO INCREASE
POPS THIS EVENING AS ANOTHER DISTURBANCE AHEAD AN OCCLUDING
FRONTAL BOUNDARY INCREASES THE THREAT FOR CONVECTION.
THE SYSTEM WILL OCCLUDE AS IT MOVES EASTWARD. WE ARE NOT EXPECTED
TO GET INTO THE WARM SECTOR IT GETS PINCHED OFF JUST TO THE SOUTH
OF OUR FORECAST AREA TONIGHT AS THE SYSTEM OCCLUDES. MODELS
CONTINUE TO SHOW SOME ELEVATED INSTABILITY WITH SHOWALTER INDICES
BELOW ZERO MOVING ACROSS THE REGION TONIGHT...SO HAVE KEEP MENTION
OF THUNDER IN THE FORECAST. ANY THUNDERSTORMS THAT OCCUR COULD
HAVE LOCALLY HEAVY DOWNPOURS...ESPECIALLY GIVEN THE STRONG THETA-E
RIDGE WHICH DEVELOPS ACROSS THE REGION OVERNIGHT.
TEMPERATURE TRENDS SINCE THE LAST UPDATE UNDER CLOUDY SKIES HAVE
DROPPED SLOWLY WITH LOWS EXPECTED TO BE IN THE 40S.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
DURING THE DAY ON TUESDAY WE CAN EXPECT SOME LINGERING SHOWERS
DURING THE DAY WITH SOME BREAKS OF SUN POSSIBLE IN THE AFTERNOON.
THE UPPER LEVEL TROUGH AXIS WILL BE PASSING THROUGH THE AREA WITH
AN ASSOCIATED VORT MAX. HIGH TEMPS ON TUESDAY ARE EXPECTED MAX
TEMPS ARE FORECAST TO REACH THE LOWER/MID 60S IN VALLEY AREAS AND
50S ACROSS HIGHER ELEVATIONS.
FOR TUESDAY NIGHT AND WEDNESDAY...A SECONDARY TROUGH IS EXPECTED
TO MOVE FROM THE MIDWEST THROUGH CENTRAL NEW YORK AND CENTRAL
PENNSYLVANIA BRINGING ANOTHER ROUND OF SHOWERS AND THIS WILL BE
FOLLOWED BY YET ANOTHER TROUGH OF LOW PRESSURE ON WEDNESDAY. THIS
IS ALL OCCURRING AT THE SURFACE WHILE ALOFT AN UPPER LEVEL CLOSED
LOW SITS AND SPINS JUST NORTH OF THE UPPER GREAT LAKES SENDING
PIECES OF ENERGY IN THE FORM OF VORT LOBES ACROSS OUR FA DURING
MUCH OF THE PERIOD. EXPECT LOWS ON TUESDAY NIGHT ARE EXPECTED TO
RANGE FROM THE UPPER 20S NORTHWEST TO AROUND 40 SOUTHEAST. SOME
LIGHT SNOW ACCUMULATIONS GENERALLY UNDER AN INCH ARE POSSIBLE
ACROSS THE WESTERN ADIRONDACKS. HIGHS ON WEDNESDAY ARE EXPECTED TO
RANGE FROM THE UPPER 40S NORTHWEST TO AROUND 690 NORTHWEST.
FOR WEDNESDAY NIGHT AND THURSDAY NOT MUCH IMPROVEMENT IS EXPECTED
AS THE UPPER LEVEL TROUGH AXIS SETTLES ACROSS THE NORTHEAST US
WHILE AT THE SURFACE LOW PRESSURE INTENSIFIES ACROSS THE GULF OF
MAINE WITH YET ANOTHER COLD FRONT EXPECTED TO MOVE INTO THE
EASTERN GREAT LAKES BY THURSDAY. THUS THERE WILL STILL BE
SCATTERED SHOWERS AROUND ALTHOUGH THE PCPN SHOULD BE MAINLY ON THE
LIGHT SIDE. EXPECT LOWS WEDNESDAY NIGHT TO BE IN THE UPPER 20S TO
UPPER 30S WITH ONCE AGAIN A LITTLE LIGHT SNOW POSSIBLE ACROSS THE
WESTERN ADIRONDACKS WITH HIGHS ON THURSDAY IN THE MID 40S TO LOWER
50S.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
BELOW NORMAL TEMPERATURES ALONG WITH SOME INTERVALS OF RAIN AND
EVEN SNOW SHOWERS ARE EXPECTED THROUGH THE WEEKEND.
MODEL GUIDANCE REMAINS IN GOOD AGREEMENT INDICATING A LARGE SCALE UPPER
LOW WILL DOMINATE OUR WEATHER. HOWEVER THERE CONTINUES TO BE SOME
DISAGREEMENT ON ITS EXACT TRACK AND WITH THE TIMING OF INDIVIDUAL SHORT
WAVE ROTATING ABOUT IT. THERE IS CONSENSUS THE CENTER OF THE UPPER
LOW SHOULD REMAIN TO OUR NORTH AS IT MOVES ACROSS EASTERN CANADA KEEPING
OUR THE REGION IN WESTERLY FLOW. HAVE FAVORED GUIDANCE FROM THE WEATHER
PREDICTION CENTER TO MAINTAIN FORECAST CONSISTENCY. THE BETTER CHANCES
FOR SCATTERED SHOWERS WILL BE ACROSS THE HIGHER TERRAIN. RAIN SHOWERS
ARE EXPECTED DURING THE DAY...BUT AT NIGHT IT WILL BE COLD ENOUGH FOR
SNOW SHOWER ESPECIALLY ACROSS THE HIGHER ELEVATIONS.
OVERALL EXPECTING HIGHS IN THE 40S AND 50S WITH LOWS IN THE 20S AND 30S.
NORMALS FOR LATE APRIL...
ALBANY NY: HIGHS IN THE LOWER 60S AND LOWS IN THE LOWER 40S.
GLENS FALLS NY: HIGHS IN THE LOWER 60S AND LOWS IN THE UPPER 30S.
POUGHKEEPSIE NY: HIGHS IN THE MID 60S AND LOWS AROUND 40.
BENNINGTON VT: HIGHS IN THE LOWER 60S AND LOWS IN THE UPPER 30S.
PITTSFIELD MA: HIGHS IN THE UPPER 50S AND LOWS IN THE MID 30S.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
A LOW PRESSURE SYSTEM WILL OCCLUDE AS IT MOVES ACROSS THE REGION
TONIGHT. WE HAVE HAD A BIT OF A LULL IN THE PRECIPITATION THIS
EVENING. HAVE SHOWERS ACTIVITY OCCURRING TO EAST AND CONVECTION TO
OUR WEST IN THE VICINITY OF THE WARM FRONT. THE HRRR SEEMS TO HAVE
A PRETTY GOOD HANDLE ON CONVECTION SO HAVE USED IT AS A GUIDE TO
INCREASE POPS THIS EVENING WITH THE BEST CHANCES AS WE APPROACH
MIDNIGHT AS ANOTHER DISTURBANCE AHEAD THE OCCLUDING FRONTAL
BOUNDARY WILL INCREASE THE THREAT FOR CONVECTION. WE ARE NOT
EXPECTED TO GET INTO THE WARM SECTOR IT GETS PINCHED OFF JUST TO
THE SOUTH OF OUR FORECAST AREA TONIGHT AS THE SYSTEM OCCLUDES.
THE MODELS CONTINUE TO SHOW SOME ELEVATED INSTABILITY WITH
SHOWALTER INDICES BELOW ZERO MOVING ACROSS THE REGION TONIGHT...SO
THERE IS A CHANCE FOR THUNDERSTORMS HOWEVER CONFIDENCE IS TOO LOW
TO INCLUDE IN THE TAFS.
CONDITIONS WILL LOWER WITH WIDESPREAD MVFR-IFR DEVELOPING.
A GRADUAL IMPROVEMENT WILL OCCUR WITH THE PASSAGE OF THE OCCLUDED
FRONT. WITH WIDESPREAD VFR FOR THE AFTERNOON.
HAVE NORTHEAST TO SOUTHEAST FLOW ACROSS AREA. RECENT OBSERVATIONS
SHOWN A DIMINISHING TREND IN WIND GUSTS ACROSS THE BERKSHIRES...
TACONICS AND SOUTHERN VERMONT WHERE THE FLOW HAS BEEN ENHANCED BY
THE TERRAIN. WINDS WILL LIGHTEN AS THE OCCLUDED BOUNDARY MOVES
THOUGH WITH A SHIFT TO SOUTHWEST TO WEST WITH ITS PASSAGE.
WESTERLY WINDS WILL INCREASE TO 10 TO 15 KNOTS AND WILL BE GUSTY
ESPECIALLY AT KALB AND KPSF.
OUTLOOK...
TUE NIGHT-WED: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
WED NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA...SHSN.
THU: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
THU NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
FRI: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
FRI NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
SAT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
&&
.FIRE WEATHER...
THERE ARE NO FIRE WEATHER CONCERNS THIS WEEK AS WE WILL BE UNDER
THE INFLUENCE OF AN UPPER LEVEL TROUGH. A WIDESPREAD SOAKING
RAINFALL WILL OCCUR ACROSS THE AREA THROUGH TONIGHT...WITH
RAINFALL AMTS OF 0.75-1.5 INCHES EXPECTED. THE WEATHER WILL BE
COOL AND UNSETTLED FOR MUCH OF THE WEEK.
&&
.HYDROLOGY...
A WIDESPREAD SOAKING RAINFALL WILL OCCUR ACROSS THROUGH TONIGHT.
EXPECTING WIDESPREAD QPF AMOUNTS OF AROUND AN INCH WITH HIGHER
AMOUNTS UP TO AROUND 1.5 INCHES WHERE THE RAINFALL IS ENHANCED BY
THE STRONG EAST TO SOUTHEAST FLOW...PARTICULARLY ACROSS THE
CENTRAL AND SOUTHEASTERN CATSKILLS...TACONICS...BERKSHIRES INTO
THE LITCHFIELD HILLS AND ACROSS SOUTHERN VERMONT. LOCALIZED HIGHER
AMOUNTS OF 2 TO 3 INCHES WILL BE POSSIBLE.
THERE IS STILL SOME SNOW COVER LEFT IN THE FORECAST AREA. BASED
ON NATIONAL OPERATIONAL HYDROLOGIC REMOTE SENSING CENTER (NOHRSC)
THIS IS ACROSS THE PORTIONS OF THE WESTERN ADIRONDACKS AND ACROSS
THE HIGHER TERRAIN OF THE SOUTHERN GREEN MOUNTAINS.
BASED ON CURRENT FORECASTS...ONLY THE WEST CANADA CREEK AT
HINCKLEY DAM IS EXPECTED TO EXCEED ITS FLOOD STAGE BY TUESDAY
EVENING.
THE REST OF THE WEEK THE FORECAST WILL BE DOMINATED BY A PERSISTENT
UPPER LEVEL TROUGH WHICH WILL RESULT IN COOL TEMPERATURES...BREEZY
CONDITIONS AND OCCASIONAL CHANCES FOR MAINLY LIGHT PRECIPITATION.
FOR DETAILS ON SPECIFIC AREA RIVER AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEB-
SITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...IAA/KL/LFM/11/WASULA
NEAR TERM...IAA/LFM/11/WASULA
SHORT TERM...11
LONG TERM...IAA
AVIATION...IAA/WASULA
FIRE WEATHER...11
HYDROLOGY...IAA/KL/11
AREA FORECAST DISCUSSION
NWS ALBANY NY
836 PM EDT MON APR 20 2015
.SYNOPSIS...
.A LOW PRESSURE SYSTEM APPROACHING FROM THE WEST WITH ASSOCIATED
FRONTS WILL BRING OCCASIONAL SHOWERS TO THE AREA ALONG WITH A FEW
RUMBLES OF THUNDER TONIGHT. WITH A LARGE STATIONARY LOW OVER THE
REGION...UNSETTLED WEATHER WILL CONTINUE THROUGH THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
THE WIND ADVISORY REMAINS IN EFFECT UNTIL MIDNIGHT FOR THE HIGHER
ELEVATIONS OF THE NORTH AND CENTRAL TACONICS...BERKSHIRES AND FOR
BENNINGTON AND WESTERN WINDHAM COUNTIES. HOWEVER RECENT OBSERVATIONS
SHOWN A DIMINISHING TREND IN WIND GUSTS. WILL LIKELY BE ABLE TO
DROP THE WIND ADVISORY EARLY.
HAVE HAD A BIT OF A LULL IN THE PRECIPITATION THIS EVENING. HAVE
SHOWERS ACTIVITY OCCURRING TO EAST AND CONVECTION TO OUR WEST IN
THE VICINITY OF THE WARM FRONT. HAVE ADJUSTED POPS TO BETTER
REFLECT CURRENT ACTIVITY. THE HRRR SEEMS TO HAVE A PRETTY GOOD
HANDLE ON CONVECTION SO HAVE USED IT AS A GUIDE TO INCREASE POPS
THIS EVENING AS ANOTHER DISTURBANCE AHEAD AN OCCLUDING FRONTAL
BOUNDARY INCREASES THE THREAT FOR CONVECTION.
THE SYSTEM WILL OCCLUDE AS IT MOVES EASTWARD. WE ARE NOT EXPECTED
TO GET INTO THE WARM SECTOR IT GETS PINCHED OFF JUST TO THE SOUTH
OF OUR FORECAST AREA TONIGHT AS THE SYSTEM OCCLUDES. MODELS
CONTINUE TO SHOW SOME ELEVATED INSTABILITY WITH SHOWALTER INDICES
BELOW ZERO MOVING ACROSS THE REGION TONIGHT...SO HAVE KEEP MENTION
OF THUNDER IN THE FORECAST. ANY THUNDERSTORMS THAT OCCUR COULD
HAVE LOCALLY HEAVY DOWNPOURS...ESPECIALLY GIVEN THE STRONG THETA-E
RIDGE WHICH DEVELOPS ACROSS THE REGION OVERNIGHT.
LOWS ARE EXPECTED TO BE IN THE 40S.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
DURING THE DAY ON TUESDAY WE CAN EXPECT SOME LINGERING SHOWERS
DURING THE DAY WITH SOME BREAKS OF SUN POSSIBLE IN THE AFTERNOON.
THE UPPER LEVEL TROUGH AXIS WILL BE PASSING THROUGH THE AREA WITH
AN ASSOCIATED VORT MAX. HIGH TEMPS ON TUESDAY ARE EXPECTED MAX
TEMPS ARE FORECAST TO REACH THE LOWER/MID 60S IN VALLEY AREAS AND
50S ACROSS HIGHER ELEVATIONS.
FOR TUESDAY NIGHT AND WEDNESDAY...A SECONDARY TROUGH IS EXPECTED
TO MOVE FROM THE MIDWEST THROUGH CENTRAL NEW YORK AND CENTRAL
PENNSYLVANIA BRINGING ANOTHER ROUND OF SHOWERS AND THIS WILL BE
FOLLOWED BY YET ANOTHER TROUGH OF LOW PRESSURE ON WEDNESDAY. THIS
IS ALL OCCURRING AT THE SURFACE WHILE ALOFT AN UPPER LEVEL CLOSED
LOW SITS AND SPINS JUST NORTH OF THE UPPER GREAT LAKES SENDING
PIECES OF ENERGY IN THE FORM OF VORT LOBES ACROSS OUR FA DURING
MUCH OF THE PERIOD. EXPECT LOWS ON TUESDAY NIGHT ARE EXPECTED TO
RANGE FROM THE UPPER 20S NORTHWEST TO AROUND 40 SOUTHEAST. SOME
LIGHT SNOW ACCUMULATIONS GENERALLY UNDER AN INCH ARE POSSIBLE
ACROSS THE WESTERN ADIRONDACKS. HIGHS ON WEDNESDAY ARE EXPECTED TO
RANGE FROM THE UPPER 40S NORTHWEST TO AROUND 690 NORTHWEST.
FOR WEDNESDAY NIGHT AND THURSDAY NOT MUCH IMPROVEMENT IS EXPECTED
AS THE UPPER LEVEL TROUGH AXIS SETTLES ACROSS THE NORTHEAST US
WHILE AT THE SURFACE LOW PRESSURE INTENSIFIES ACROSS THE GULF OF
MAINE WITH YET ANOTHER COLD FRONT EXPECTED TO MOVE INTO THE
EASTERN GREAT LAKES BY THURSDAY. THUS THERE WILL STILL BE
SCATTERED SHOWERS AROUND ALTHOUGH THE PCPN SHOULD BE MAINLY ON THE
LIGHT SIDE. EXPECT LOWS WEDNESDAY NIGHT TO BE IN THE UPPER 20S TO
UPPER 30S WITH ONCE AGAIN A LITTLE LIGHT SNOW POSSIBLE ACROSS THE
WESTERN ADIRONDACKS WITH HIGHS ON THURSDAY IN THE MID 40S TO LOWER
50S.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
BELOW NORMAL TEMPERATURES ALONG WITH SOME INTERVALS OF RAIN AND
EVEN SNOW SHOWERS ARE EXPECTED THROUGH THE WEEKEND.
MODEL GUIDANCE REMAINS IN GOOD AGREEMENT INDICATING A LARGE SCALE UPPER
LOW WILL DOMINATE OUR WEATHER. HOWEVER THERE CONTINUES TO BE SOME
DISAGREEMENT ON ITS EXACT TRACK AND WITH THE TIMING OF INDIVIDUAL SHORT
WAVE ROTATING ABOUT IT. THERE IS CONSENSUS THE CENTER OF THE UPPER
LOW SHOULD REMAIN TO OUR NORTH AS IT MOVES ACROSS EASTERN CANADA KEEPING
OUR THE REGION IN WESTERLY FLOW. HAVE FAVORED GUIDANCE FROM THE WEATHER
PREDICTION CENTER TO MAINTAIN FORECAST CONSISTENCY. THE BETTER CHANCES
FOR SCATTERED SHOWERS WILL BE ACROSS THE HIGHER TERRAIN. RAIN SHOWERS
ARE EXPECTED DURING THE DAY...BUT AT NIGHT IT WILL BE COLD ENOUGH FOR
SNOW SHOWER ESPECIALLY ACROSS THE HIGHER ELEVATIONS.
OVERALL EXPECTING HIGHS IN THE 40S AND 50S WITH LOWS IN THE 20S AND 30S.
NORMALS FOR LATE APRIL...
ALBANY NY: HIGHS IN THE LOWER 60S AND LOWS IN THE LOWER 40S.
GLENS FALLS NY: HIGHS IN THE LOWER 60S AND LOWS IN THE UPPER 30S.
POUGHKEEPSIE NY: HIGHS IN THE MID 60S AND LOWS AROUND 40.
BENNINGTON VT: HIGHS IN THE LOWER 60S AND LOWS IN THE UPPER 30S.
PITTSFIELD MA: HIGHS IN THE UPPER 50S AND LOWS IN THE MID 30S.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
A LOW PRESSURE SYSTEM WILL OCCLUDE AS IT MOVES ACROSS THE REGION
TONIGHT. WE HAVE HAD A BIT OF A LULL IN THE PRECIPITATION THIS
EVENING. HAVE SHOWERS ACTIVITY OCCURRING TO EAST AND CONVECTION TO
OUR WEST IN THE VICINITY OF THE WARM FRONT. THE HRRR SEEMS TO HAVE
A PRETTY GOOD HANDLE ON CONVECTION SO HAVE USED IT AS A GUIDE TO
INCREASE POPS THIS EVENING WITH THE BEST CHANCES AS WE APPROACH
MIDNIGHT AS ANOTHER DISTURBANCE AHEAD THE OCCLUDING FRONTAL
BOUNDARY WILL INCREASE THE THREAT FOR CONVECTION. WE ARE NOT
EXPECTED TO GET INTO THE WARM SECTOR IT GETS PINCHED OFF JUST TO
THE SOUTH OF OUR FORECAST AREA TONIGHT AS THE SYSTEM OCCLUDES.
THE MODELS CONTINUE TO SHOW SOME ELEVATED INSTABILITY WITH
SHOWALTER INDICES BELOW ZERO MOVING ACROSS THE REGION TONIGHT...SO
THERE IS A CHANCE FOR THUNDERSTORMS HOWEVER CONFIDENCE IS TOO LOW
TO INCLUDE IN THE TAFS.
CONDITIONS WILL LOWER WITH WIDESPREAD MVFR-IFR DEVELOPING.
A GRADUAL IMPROVEMENT WILL OCCUR WITH THE PASSAGE OF THE OCCLUDED
FRONT. WITH WIDESPREAD VFR FOR THE AFTERNOON.
HAVE NORTHEAST TO SOUTHEAST FLOW ACROSS AREA. RECENT OBSERVATIONS
SHOWN A DIMINISHING TREND IN WIND GUSTS ACROSS THE BERKSHIRES...
TACONICS AND SOUTHERN VERMONT WHERE THE FLOW HAS BEEN ENHANCED BY
THE TERRAIN. WINDS WILL LIGHTEN AS THE OCCLUDED BOUNDARY MOVES
THOUGH WITH A SHIFT TO SOUTHWEST TO WEST WITH ITS PASSAGE.
WESTERLY WINDS WILL INCREASE TO 10 TO 15 KNOTS AND WILL BE GUSTY
ESPECIALLY AT KALB AND KPSF.
OUTLOOK...
TUE NIGHT-WED: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
WED NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA...SHSN.
THU: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
THU NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
FRI: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
FRI NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
SAT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
&&
.FIRE WEATHER...
THERE ARE NO FIRE WEATHER CONCERNS THIS WEEK AS WE WILL BE UNDER
THE INFLUENCE OF AN UPPER LEVEL TROUGH. A WIDESPREAD SOAKING
RAINFALL WILL OCCUR ACROSS THE AREA THROUGH TONIGHT...WITH
RAINFALL AMTS OF 0.75-1.5 INCHES EXPECTED. THE WEATHER WILL BE
COOL AND UNSETTLED FOR MUCH OF THE WEEK.
&&
.HYDROLOGY...
A WIDESPREAD SOAKING RAINFALL WILL OCCUR ACROSS THROUGH TONIGHT.
EXPECTING WIDESPREAD QPF AMOUNTS OF AROUND AN INCH WITH HIGHER
AMOUNTS UP TO AROUND 1.5 INCHES WHERE THE RAINFALL IS ENHANCED BY
THE STRONG EAST TO SOUTHEAST FLOW...PARTICULARLY ACROSS THE
CENTRAL AND SOUTHEASTERN CATSKILLS...TACONICS...BERKSHIRES INTO
THE LITCHFIELD HILLS AND ACROSS SOUTHERN VERMONT. LOCALIZED HIGHER
AMOUNTS OF 2 TO 3 INCHES WILL BE POSSIBLE.
THERE IS STILL SOME SNOW COVER LEFT IN THE FORECAST AREA. BASED
ON NATIONAL OPERATIONAL HYDROLOGIC REMOTE SENSING CENTER (NOHRSC)
THIS IS ACROSS THE PORTIONS OF THE WESTERN ADIRONDACKS AND ACROSS
THE HIGHER TERRAIN OF THE SOUTHERN GREEN MOUNTAINS.
BASED ON CURRENT FORECASTS...ONLY THE WEST CANADA CREEK AT
HINCKLEY DAM IS EXPECTED TO EXCEED ITS FLOOD STAGE BY TUESDAY
EVENING.
THE REST OF THE WEEK THE FORECAST WILL BE DOMINATED BY A PERSISTENT
UPPER LEVEL TROUGH WHICH WILL RESULT IN COOL TEMPERATURES...BREEZY
CONDITIONS AND OCCASIONAL CHANCES FOR MAINLY LIGHT PRECIPITATION.
FOR DETAILS ON SPECIFIC AREA RIVER AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEB-
SITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...WIND ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR NYZ054-061.
MA...WIND ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR MAZ001-025.
VT...WIND ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR VTZ013-014.
&&
$$
SYNOPSIS...IAA/KL/LFM/11/WASULA
NEAR TERM...IAA/11/WASULA
SHORT TERM...11
LONG TERM...IAA
AVIATION...IAA/WASULA
FIRE WEATHER...11
HYDROLOGY...IAA/KL/11
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
345 PM EDT SUN APR 19 2015
.DISCUSSION...
TONIGHT...SOUTHERN EDGE OF CONVECTIVE BAND MOVING INTO NE GULF AND
NORTH FL HAS BEEN WEAKENING RECENTLY AND HRRR/WRF MODELS INDICATE
THIS TREND WILL CONTINUE. HOWEVER SOME PRECIP/EMBEDDED STORM
ACTIVITY FROM THIS BAND MAY REACH LAKE COUNTY TOWARD SUNSET. AHEAD
OF THIS LINE HRRR CONTINUES TO SHOW SOME ISO/SCT STORMS FORMING
ESPECIALLY NEAR THE COAST FROM BOUNDARY COLLISIONS WITH THE EAST
COAST SEA BREEZE. LATEST SFC OBS SHOW THE SEA BREEZE HAS BEEN ABLE
TO HOLD ON RIGHT ALONG THE COAST AT SOME LOCATIONS. HOWEVER AN
INCREASING LOW LEVEL S/SW FLOW INTO LATE DAY MAY PUSH WHAT SEA
BREEZE REMAINS OFFSHORE. IF SO CONVECTIVE ACTIVITY MAY BE LIMITED
INTO THIS EVENING. FOR NOW WILL HOLD ONTO A CHANCE FOR STORMS INTO
THE EVENING MAINLY ALONG THE COAST. IF ANY BOUNDARY COLLISIONS DO
OCCUR ISO STRONG STORMS NOT OUT OF THE QUESTION.
RAIN CHANCES END BY MIDNIGHT WITH ANY SHOWERS/STORMS PUSHING
OFFSHORE. OVERNIGHT LOWS WILL BE IN THE UPPER 60S TO LOW 70S.
MONDAY...MODELS SHOW ANOTHER MID LEVEL S/W PUSHING THROUGH THE NRN
GULF AHEAD OF WEAK FRONT MOVING INTO THE SOUTHEAST STATES. THIS
DISTURBANCE WILL LIKELY LEAD TO ANOTHER BAND OF CONVECTION
DEVELOPING OVER THE CENTRAL/EASTERN GULF SHIFTING EASTWARD TOWARD
THE FL PENINSULA IN THE EARLY MORNING HOURS. NAM AND TO A DEGREE THE
WRF SHOW THIS BAND DEVELOPING FARTHER NORTH AND PUSHING ACROSS MUCH
OF THE REGION INTO THE AFT WHILE THE GFS/ECMWF KEEP GREATEST RAIN
CHANCES/MOISTURE SOUTH OF ORLANDO. HAVE LEANED TOWARD A BLEND FOR
NOW WHICH KEEPS RAIN CHANCES FAIRLY CONSISTENT AROUND 50-60 PERCENT.
SOME STRONG TO ISO SEVERE STORMS POSSIBLE IF ENOUGH HEATING CAN
OCCUR OUT AHEAD OF ANY CONVECTION OVER THE GULF. MAIN THREAT WOULD
BE STRONG WIND GUSTS AND HAIL.
TUE...A COOL FRONT WILL SETTLE SOUTH ACROSS CENTRAL FL BRINGING SOME
DRIER AIR AND TEMPERATURES MORE SEASONABLE FOR THIS TIME OF YEAR IN
THE LOW TO MID 80S. HAVE LOWERED RAIN CHANCES ACROSS THE NORTH TO 20
PERCENT NORTH OF ORLANDO AND THIS MAY BE GENEROUS. MOISTURE LINGERING
ACROSS THE SOUTH WILL KEEP RAIN CHANCES 40 TO 50 PERCENT FROM
OKEECHOBEE TO THE TREASURE COAST.
REST OF WEEK (PREVIOUS)...DEPARTURE OF STRONG UPR WIND MAXIMA WL BRING
EVOLUTION TO ZONAL PATTERN WITH BROAD WEAK HIGH DOWNSTREAM ACTING
TO STABILIZE AIRMASS...WITH SOME DRYING AS WELL OVER THE NORTH AT
MIDWEEK. AFTERNOON BOUNDARY INTERACTION AND SUFFICIENT LL MOISTURE
WL FORCE SOME SHOWERS AND SLOW MOVING STORMS WED-THU WITH AT LEAST
MENTIONABLE RAIN CHCS IN THE EXTENDED FCST LACKING ANY NOTABLE
PATTERN CHG AND OR DRYING OF THE AMBIENT AIRMASS.
&&
.AVIATION...
TEMPO IFR/MVFR CONDS IN ISO/SCT SHRA/TSRA MAINLY TOWARD THE COAST
WILL OCCUR AHEAD OF APPROACHING BAND OF CONVECTION THAT IS
WEAKENING OVER THE NE GULF. THIS BAND MAY REACH AREAS WEST OF I-4
TOWARD SUNSET...PRODUCING ADDITIONAL REDUCTIONS TO CIG/VIS MAINLY AT
KLEE. CONVECTION THEN DIMINISHING/PUSHING OFFSHORE INTO LATE EVENING
WITH MAINLY VFR OVERNIGHT. DEEP MOISTURE AND AN APPROACHING
DISTURBANCE ALOFT WILL KEEP HIGH RAIN CHANCES IN THE FORECAST FOR
TOMORROW WITH SCT-NMRS SHRA/TSRA PRODUCING TEMPO IFR/MVFR CONDS INTO
THE AFT.
&&
.MARINE...
TONIGHT-MONDAY...S/SW WINDS UP TO 10-15 KNOTS WILL BECOME MORE W/SW
INTO LATE MON AS A WEAK FRONTAL BOUNDARY PUSHES INTO THE SOUTHEAST
STATES. SEAS WILL REMAIN AROUND 2-4 FEET. MAIN CONCERN WILL CONTINUE
TO BE FOR OFFSHORE MOVING STORMS THIS EVENING AND TOMORROW AFT/EVE...
PRODUCING STRONG GUSTY WINDS.
TUE-THU...WEAK FRONT PROGGED TO MOVE DOWN THE FL PENINSULA TUE SO
WIND FLOW WILL BE W/NW 10 KNOTS. FLOW BEHIND THE FRONT MID WEEK WILL
BECOME ONSHORE AROUND 10 KNOTS. SEAS WILL REMAIN 4 FEET OR LESS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 69 84 68 80 / 40 40 20 20
MCO 70 87 69 83 / 20 50 20 30
MLB 71 87 70 82 / 40 60 30 30
VRB 70 87 70 83 / 40 60 30 50
LEE 70 84 68 82 / 20 50 20 20
SFB 70 85 69 83 / 30 50 20 20
ORL 71 86 69 83 / 20 50 20 30
FPR 69 87 70 83 / 40 60 30 50
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM...WEITLICH
LONG TERM....KELLY
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
127 PM EDT SUN APR 19 2015
...TORNADO WATCH TIL 8PM I-10 CORRIDOR NORTHWARD...
...POTENTIAL FOR A FEW STRONG/SEVERE STORMS AGAIN MONDAY...
.NEAR TERM...THROUGH TONIGHT...
WATER VAPOR SHOWING AN IMPRESSIVE SHORTWAVE THAT WILL MOVE
EASTWARD TOWARD AND OVER FORECAST AREA THROUGH THIS EVENING. BAND
OF SHOWERS AND EMBEDDED THUNDERSTORMS WILL ACCOMPANY WAVE THIS
AFTERNOON. SUFFICIENT INSTABILITY AND DEEP-LAYER SHEAR AHEAD OF
SYSTEM TO SUPPORT A FEW STRONG OR SEVERE STORMS EMBEDDED WITHIN
THE LINE...MAINLY BOWING LINE SEGMENTS WITH DAMAGING WIND
POTENTIAL...THOUGH AN ISOLATED TORNADO IS ALSO POSSIBLE. IN
ADDITION...STARTING TO SEE CONVECTION BREAK OUT AHEAD OF SYSTEM
OVER OUR WRN COUNTIES. GIVEN THE ENVIRONMENT IN PLACE...THERE IS
POTENTIAL FOR A FEW DISCRETE STRONG/SEVERE CELLS TO DEVELOP THIS
AFTERNOON. LATEST HRRR SUGGESTS THIS ACTIVITY COULD INTENSIFY AS
IT SPREADS NORTHEAST OVER THE NEXT FEW HOURS. TORNADO WATCH IS IN
EFFECT FOR AREAS FROM THE I-10 CORRIDOR NORTHWARD TIL 8PM.
BAND OF SHOWERS/STORMS WILL MOVE QUICKLY NORTH AND EAST ACROSS
FORECAST AREA BETWEEN 2PM AND 7PM...THEN MOVE OFFSHORE. LOW TEMPS
EXPECTED TO BE 68-70 MOST LOCATIONS.
SHORT TERM...MONDAY THROUGH TUESDAY NIGHT... FOR MONDAY...COLD
FRONT APPROACHES FROM THE NORTHWEST. MORE WESTERLY FLOW AT LOW AND
MID LEVELS BRINGS IN DRIER AIR...AND AS A RESULT THE MODELS
DEVELOP CONSIDERABLY LESS PRECIP COVERAGE MONDAY AFTERNOON
COMPARED TO THIS AFTERNOON. WILL MAINTAIN 30-40 POP FOR MONDAY
AFTERNOON. ONCE AGAIN SPC HAS SLIGHT RISK OF SEVERE STORMS OVER
OUR AREA...AND ONCE AGAIN WE SHOULD HAVE FAVORABLE COMBINATION OF
MODERATE CAPE AND SUFFICIENT DEEP LAYER SHEAR. LOW-LEVEL WINDS
WILL BE MORE SW AHEAD OF COLD FRONT...AND THIS WILL REDUCE
HELICITY...SO PRIMARY THREAT WILL BE STRONG WINDS. WARM AGAIN
MONDAY WITH HIGHS IN THE MID 80S ACROSS THE FORECAST AREA.
COLD FRONT MOVES ACROSS THE AREA LATE MONDAY NIGHT...WITH SOMEWHAT
COOLER DRIER CONDITIONS TUESDAY. CURRENT FORECAST HIGH TEMPS OF
UPPER 70S SE GA...AROUND 80 I-10 CORRIDOR...AND LOW 80S GNV/OCF
LOOKS FINE. COOLER NIGHT TUESDAY NIGHT WITH LOW TEMPS 55-60 ACROSS
THE AREA...EXCEPT LOW 60S COAST.
LONG TERM...WEDNESDAY THROUGH SUNDAY...
GIVEN THE HIGH IMPACT THREATS THROUGH MONDAY...DID NOT MAKE
SIGNIFICANT CHANGES TO THE MEDIUM RANGE GIVEN NOT MUCH
SIGNIFICANT CHANGE IN LATEST MODEL GUIDANCE. STILL EXPECT WEAK
SURFACE RIDGING AND ZONAL FLOW ALOFT THROUGH THE END OF THE
WORKWEEK...WITH SOME INCREASE IN TEMPS AS WELL AS SLIGHT CHANCES
FOR SHOWERS WITH SEA BREEZES. BETTER RAIN CHANCES MAY STILL COME
OVER WEEKENDD... THOUGH SOME UNCERTAINTY AS TO TRACK OF NEXT WEEK
SYSTEM AND WHERE THE MORE WIDESPREAD PRECIPITATION WILL END UP.
&&
.AVIATION...MAIN SQUALL LINE WELL WEST OF THE LOCAL FIELDS WITH
GAINESVILLE MOST LIKELY TO FEEL ITS IMPACT. EXPECT CONVECTION TO
MOVE IN THERE BETWEEN 19-21 UTC WITH CEILINGS IN THE 2.5 KFT RANGE.
THE COAST FIELDS FROM SAINT AUGUSTINE THROUGH THE JACKSONVILLE METRO
AREA TO SAINT SIMONS ISLAND SHOULD SEE A CONVERGENCE BETWEEN THE
DOMINANT SOUTHWESTERLY LOW LEVEL FLOW PATTERN AND THE DEVELOPING
ATLANTIC SEA BREEZE FRONT. EXPECT STRONG TO POSSIBLY SEVERE
CONVECTION TO FIRE UP ALONG THE ATLANTIC COAST WITH CEILINGS BETWEEN
2.5-5 KFT. THESE STORMS SHOULD PASS OFFSHORE THIS EVENING BY 23OO
UTC AS THE WEAKENING SQUALL LINE MAKES ITS RUN AT THE COAST.
&&
.MARINE....WINDS WILL GRADUALLY INCREASE AND VEER OUT AHEAD OF
APPROACHING COLD FRONT ALTHOUGH NO HEADLINES EXPECTED THRU MONDAY.
THE COLD FRONT CROSSES THE WATERS MONDAY NIGHT BRINGING A BRIEF
PERIOD OF CONDITIONS APPROACHING ADVISORY CRITERIA IN THE
OFFSHORE COMPONENT. SCATTERED TO NUMEROUS AFTERNOON AND EVENING
SHOWERS/TSMS THRU MONDAY... WITH STRONG WINDS POSSIBLE WITH THE
MORE INTENSE STORMS. HIGH PRESSURE QUICKLY BUILDS IN BEHIND THE
FRONT TUE WITH WIND/SEAS DECREASING FOR REMAINDER OF WEEK.
.RIP CURRENTS...MODERATE RISK THIS AFTERNOON...LOW RISK MONDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 67 85 60 77 / 30 30 20 10
SSI 69 82 65 75 / 30 30 20 10
JAX 69 85 64 79 / 30 30 20 10
SGJ 70 83 67 77 / 30 40 20 10
GNV 68 85 65 81 / 20 40 20 10
OCF 69 85 66 82 / 20 40 20 10
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...NONE.
&&
$$
WOLF/SANDRIK/WALKER
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
901 AM EDT SUN APR 19 2015
...INCREASING POTENTIAL FOR STRONG/SEVERE STORMS THIS AFTERNOON...
.UPDATE...
INTERESTING ENVIRONMENTAL SETUP FOR THIS AFTERNOON IN OUR AREA.
INITIAL PRECIPITATION AREA EXITING TO NORTHEAST WITH INITIAL
SHORTWAVE SEEN ON WATER VAPOR IMAGERY. VISIBLE IMAGERY SHOWING
AREA OF CLEARING...JUST SOME HIGH CLOUDS...SOUTHWEST GA/NW AND
WCTRL FL WHICH WILL SHIFT EASTWARD AHEAD OF DEVELOPING CONVECTION
OVER GULF OF MEX. THUS SHOULD ALLOW SURFACE TEMPS TO RISE INTO
80-85 RANGE ACROSS FCST AREA...DESTABILIZING AIRMASS.
GENERALLY FOLLOWING THE HRRR...ANTICIPATE INCREASE/UPSCALE IN
CONVECTION W OF FORECAST AREA INTO NRN GULF THROUGH THE MORNING
APPROACHING OUR WRN COUNTIES TOWARD 18Z...AHEAD OF A WELL-DEFINED
SHORTWAVE SEEN ON WATER VAPOR. MODELS BRING SHORT WAVE OVER OUR
FORECAST AREA LATE THIS AFTERNOON.
MEANWHILE...MORNING SOUNDINGS SUGGEST POTENTIAL FOR EAST COAST
SEA BREEZE TO MAKE SOME PROGRESS INLAND...PERHAPS TO I-95 CORRIDOR
MID AFTERNOON WHILE WEST COAST SEA BREEZE MOVES EASTWARD DURING
AFTERNOON.
LATEST HRRR SUGGESTS TWO AREAS OF CONCERN...FIRST IS AN ORGANIZED
LINE...OR LINE SEGMENTS...MOVING NORTHEAST ACROSS OUR WESTERN
COUNTIES 18Z-21Z...AND EASTERN COUNTIES 21Z-00Z. PRIMARY THREAT
WILL BE LOCALLY SEVERE WINDS WITH BOWING SEGMENTS GIVEN UNSTABLE
AIRMASS AND DECENT LOW-LEVEL LAPSE RATES. FEEL THE BEST POTENTIAL
FOR SEVERE WEATHER FROM THIS PORTION WILL BE SUWANNEE VALLEY
REGION OF NE FL...AND MUCH OF SE GA. SUFFICIENT LOW-LEVEL
SHEAR/HELICITY SUCH THAT ISOLATED TORNADOES WILL BE POSSIBLE. A
TORNADO WATCH IS ISSUED WEST OF OUR AREA...AND WOULD ANTICIPATE
EASTWARD EXPANSION THIS AFTERNOON. HRRR SUGGESTS WEAKENING OF
THIS ACTIVITY AS IT MOVES EAST OVER OUR FORECAST AREA...BUT
UNCERTAIN OF THIS SOLUTION GIVEN WELL DEFINED SHORT WAVE AND
DIFFLUENCE IN RIGHT-REAR QUAD SUPPORTING CONVECTION.
A SECOND AREA OF CONCERN IS ASSOCIATED WITH EASTWARD MOVING WEST
COAST SEA BREEZE...WHICH HRRR SUGGESTS COULD INITIATE DISCRETE
CELLULAR CONVECTION AFTER 18Z OVER EASTERN PORTION OF NE FL...
PARTICULARLY LATER IN AFTERNOON AS IT CONVERGES WITH EAST COAST
SEA BREEZE. COMBINATION OF CAPE VALUES 2000-3000 J/KG AND DEEP
LAYER SHEAR VALUES NEAR 40KTS SUGGEST SOME SUPERCELL STRUCTURES
POSSIBLE...WITH POTENTIAL FOR ISOLATED STRONG/SEVERE STORMS.
PRIMARY THREAT HERE WOULD BE STRONG WINDS AND HAIL...BUT CANNOT
RULE OUT ISOLATED TORNADO ESPECIALLY FAR EASTERN COUNTIES IF FLOW
IS BACKED NEAR EAST COAST SEA BREEZE.
&&
.AVIATION...VFR CONDITIONS THRU EARLY AFTERNOON...WITH POTENTIAL
FOR MVFR CONDITIONS ASSOCIATED WITH SCATTERED TO NUMEROUS TSRA.
&&
.MARINE...NO SIGNIFICANT CHANGES PLANNED IN NEXT CWF ISSUANCE.
WINDS WILL BECOME SOUTH TODAY WITH 2-4 FT SEAS. SHOWERS/T-STORMS
WILL INCREASE DURING THE AFTERNOON INTO THE EARLY EVENING HOURS.
RIP CURRENTS: MODERATE RISK TODAY DUE TO LINGERING SWELL.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 82 65 82 58 / 80 30 30 20
SSI 79 68 81 64 / 80 30 30 20
JAX 84 67 84 62 / 80 30 30 20
SGJ 82 68 82 65 / 70 30 40 20
GNV 85 67 83 64 / 70 20 40 20
OCF 86 67 83 65 / 60 20 40 20
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...NONE.
&&
$$
WOLF/SANDRIK/WALKER
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
939 PM EDT MON APR 20 2015
.SYNOPSIS...
A COLD FRONT WILL CROSS THE AREA LATE TONIGHT. DRIER HIGH
PRESSURE WILL BUILD IN TUESDAY AND WEDNESDAY. A WEAK COLD FRONT
WILL DROP THROUGH THE AREA THURSDAY NIGHT...THEN WILL STALL TO
THE SOUTH. A STORM SYSTEM WILL AFFECT THE REGION FRIDAY NIGHT
THROUGH SATURDAY NIGHT. HIGH PRESSURE WILL BUILD IN FROM THE
NORTHWEST SUNDAY INTO MONDAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
21/01Z MESOANALYSIS PLACED THE COLD FRONT FROM THE WESTERN NORTH
CAROLINA PIEDMONT INTO THE SOUTH CAROLINA UPSTATE AND EXTENDING
SOUTHWEST TO NEAR COLUMBUS GEORGIA. ISOLATED STRONG TO SEVERE
TSTMS CONTINUE TO FIRE ALONG AND JUST AHEAD OF THE FRONT AS
INCREASING 0-6KM BULK SHEAR COUPLED WITH INTENSIFYING UPPER
FORCING ASSOCIATED WITH LEFT EXIT REGION OF A 140 JET JET STREAK
COMPENSATE FOR WANING SURFACE BASED INSTABILITY.
THE H3R HAS SHOWN REMARKABLE RUN-TO-RUN CONSISTENCY IN
REDEVELOPING ISOLATED TO PERHAPS LOW-END SCATTERED CONVECTION
ACROSS EAST-CENTRAL GEORGIA AND CSRA ALONG THE FRONT AS THE CORE
OF THE MOST INTENSE UPPER FORCING TRAVERSES THE AREA OVER THE NEXT
3-5 HOURS. THE 21/00Z KCHS RAOB SHOWED A STRONG CAPPING INVERSION
AT 872 HPA...WHILE WEST OF THE I-95 CORRIDOR RAP SOUNDINGS
DEPICTED CONSIDERABLY LESS CAPPING WITH MLCAPE HOLDING 500-700
J/KG THROUGH ABOUT 2 AM. SUSPECT THIS WILL BE ENOUGH TO SUSTAIN
ANY UPSTREAM FORCED CONVECTION FOR SEVERAL MORE HOURS... BEFORE
WEAKENING AS IT APPROACHES THE COAST. WILL HIGHLIGHT SLIGHT CHANCE
POPS ALONG AND JUST AHEAD OF THE FRONT FOR ALL AREAS. STILL CAN
NOT RULE OUT AN ISOLATED STRONG TO SEVERE TSTM GIVEN THE AMOUNT OF
BULK SHEAR AND DCAPE IN PLACE WITH DAMAGING WIND GUSTS BEING THE
PRIMARY HAZARD.
LOWS FROM THE UPPER 50S FAR INTERIOR SOUTHEAST GEORGIA TO THE MID
60S AT THE COAST LOOK REASONABLE.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
TUESDAY AND WEDNESDAY...SURFACE HIGH PRESSURE CENTERED OVER THE GULF
COAST STATES WILL EDGE EASTWARD AND EXPAND OVER THE AREA.
ALOFT...FLOW WILL REMAIN NEARLY ZONAL BETWEEN A LOW SPINNING OVER
EASTERN CANADIAN AND SUBTROPICAL RIDGE TO OUR SOUTH. COOLER AND
MUCH DRIER AIRMASS WILL TAKE HOLD...AND WITH SUBSIDENCE NOTED IN
MODEL SOUNDINGS BOTH DAYS SHOULD BE PRECIP-FREE. WEAK DOWNSLOPE
FLOW WILL HELP HIGHS REACH THE UPPER 70S TUESDAY...UPPER 70S/LOW
80S ON WEDNESDAY. LOWS TUESDAY NIGHT WILL BE IN THE LOW
50S...WHILE WEDNESDAY NIGHT IS MORE MILD WITH INCREASING CLOUD
COVER IN THE LOW 60S.
WEDNESDAY NIGHT INTO THURSDAY...SURFACE HIGH WILL SHIFT INTO THE
ATLANTIC AHEAD OF A WEAK COLD FRONT APPROACHING FROM THE NORTHWEST.
THE FRONT WILL CROSS THROUGH THE FORECAST ON THURSDAY EVENING.
DESPITE A PASSING SHORTWAVE...MOISTURE IS NOT OVERLY IMPRESSIVE.
GIVEN THAT MODELS ARE STILL PRETTY INCONSISTENT ON QPF DURING THIS
TIME FRAME WITH THE EURO NEARLY DRY/GFS THE WETTER SOLUTION...HAVE
OPTED TO CAP POPS BELOW 15 PERCENT FOR NOW. HIGHS WILL BE IN THE
UPPER 70S/LOW 80S.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
A BACK DOOR COLD FRONT WILL DROP THROUGH THE AREA THURSDAY NIGHT AND
FRIDAY...BRIEFLY STALLING TO THE SOUTH. FRIDAY TENTATIVELY LOOKS DRY
WITH HIGHS IN THE MID/UPPER 70S. INCREASING UPPER SHORTWAVE ENERGY
FRIDAY NIGHT INTO SATURDAY WILL ALLOW THE FRONT TO LIFT NORTH WITH A
LOW PRESSURE SYSTEM LIFTING INTO THE MID-ATLANTIC REGION. A COLD
FRONT WILL PUSH THROUGH SATURDAY OR SATURDAY NIGHT WITH WEAK HIGH
PRESSURE BUILDING IN SUNDAY. THERE ARE SIGNIFICANT MODEL DIFFERENCES
REGARDING PRECIPITATION POTENTIAL DURING THE PERIOD. WE MAINTAINED
THE HIGHEST POPS DURING THE DAY SATURDAY...DECREASING SATURDAY
NIGHT. BELOW-NORMAL TEMPS EXPECTED SUNDAY AND MONDAY AS HIGH
PRESSURE LINGERS TO THE NORTH.
&&
.AVIATION /01Z TUESDAY THROUGH SATURDAY/...
VFR. HIGH RESOLUTION MODELS SUGGEST A BROKEN LINE OF SHOWERS AND
TSTMS COULD MOVE ACROSS THE TERMINALS 04-07Z...BUT CONFIDENCE IS
QUITE LOW. WILL NOT INCLUDE A MENTION SHRA/TSRA ATTM.
EXTENDED AVIATION OUTLOOK...LOW STRATUS OR FOG POSSIBLE AROUND
DAYBREAK THURSDAY AND FRIDAY MORNINGS.
&&
.MARINE...
OVERNIGHT...A TIGHT PRESSURE GRADIENT BETWEEN A MESO-HIGH INDUCED
BY SEVERE CONVECTION OVER FLORDIA AND THE APPROACHING COLD FRONT
HAS BEEN SUPPORTING WIND GUSTS OVER 30 KT AT BOTH BUOY 41004 AND
41008 OVER THE PAST FEW HOURS. ELEVATED WINDS WILL PERSIST ACROSS
THE GEORGIA NEARSHORE WATERS FOR A FEW MORE HOURS...SO EXPANDED
THE SMALL CRAFT ADVISORY THERE UNTIL 2 AM. THE ADVISORY FOR THE
GEORGIA OFFSHORE WATERS REMAINS IN EFFECT UNTIL 8 AM. WINDS WILL
REMAIN 15-20 KT OVER THE SOUTH CAROLINA WATERS WITH 10 KT IN THE
CHARLESTON HARBOR. SEAS WILL AVERAGE 2-4 FT NEARSHORE WATERS AND
4-5 FT OFFSHORE WATERS.
TUESDAY THROUGH SATURDAY...CONDITIONS WILL REMAIN RATHER BENIGN OVER
THE MARINE ZONES. SURFACE HIGH PRESSURE WILL EXPAND OVER THE WATERS
TUESDAY BEHIND THE DEPARTING COLD FRONT...ALLOWING THE PRESSURE
GRADIENT TO RELAX. THE HIGH WILL THEN SHIFT EAST INTO THE ATLANTIC
WEDNESDAY INTO THURSDAY AHEAD OF A WEAK COLD FRONT APPROACHING FROM
THE NORTHWEST. THE FRONT IS EXPECTED TO CROSS THROUGH THE WATERS
THURSDAY NIGHT. ANOTHER STORM SYSTEM EXPECTED TO APPROACH SATURDAY.
WEAK PRESSURE GRADIENT WILL KEEP WINDS AT OR BELOW 15 KTS ON AVERAGE
WITH SEAS 2-4 FEET HIGHEST IN THE OUTER WATERS...WELL BELOW SMALL
CRAFT ADVISORY CRITERIA.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT TUESDAY FOR AMZ374.
SMALL CRAFT ADVISORY UNTIL 2 AM EDT TUESDAY FOR AMZ354.
&&
$$
ST
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
425 PM EDT SUN APR 19 2015
.SYNOPSIS...
A COLD FRONT WILL APPROACH THE AREA MONDAY. THE FRONT WILL CROSS THE
REGION MONDAY NIGHT AND WILL SHIFT OFFSHORE BY EARLY TUESDAY. HIGH
PRESSURE WILL THEN PREVAIL TUESDAY INTO THURSDAY. A WEAK COLD FRONT
WILL DROP THROUGH THE AREA THURSDAY NIGHT...THEN WILL STALL JUST
SOUTH OF THE REGION LATE WEEK. A STORM SYSTEM WILL AFFECT THE REGION
NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
REST OF THE AFTERNOON AND EVENING...THUNDERSTORMS ARE CURRENTLY
PROGRESSING THROUGH SOUTHEAST GEORGIA AND THE TORNADO WATCH HAS
BEEN EXPANDED TO INCLUDE CHARLESTON COUNTY...BERKELEY
COUNTY...CHARLESTON HARBOR...AND AMZ350. THE ENVIRONMENT HAS SET
UP MUCH LIKE WAS ANTICIPATED THIS MORNING. TEMPERATURES ACROSS
SOUTHEAST GEORGIA HAVE WARMED INTO THE LOW 80S IN MANY AREAS WITH
DEW POINTS IN THE LOW 70S. SURFACE BASED CAPE VALUES ARE IN THE
2000-2500 J/KG RANGE AND 0-3 KM SHEAR IS ON THE ORDER OF 30-35 KT.
THE NEAR SURFACE FLOW IS BACKED TO MORE SOUTHEASTERLY WHICH IS
ENHANCING THE STORM RELATIVE HELICITY VALUES INTO THE 200 RANGE.
CURRENT RADAR TRENDS SHOW LINEAR CONVECTION JUST TO THE WEST WITH
MORE DISCRETE CELLULAR DEVELOPMENT FURTHER SOUTH ACROSS THE
NORTHERN EXTENT OF JAX/S FORECAST AREA. THE CONVECTIVE MODE WILL
CONTINUE TO FAVOR LINEAR SEGMENTS AND WITH THE SHEAR/INSTABILITY
COMBINATION EMBEDDED SUPERCELL ELEMENTS ARE EXPECTED. HI-RES MODEL
RUNS SUCH AS THE HRRR CONTINUE TO SHOW AN ELEVATED MIXED LAYER
SIGNATURE IN THE SOUNDINGS. DAMAGING WINDS CONTINUE TO BE THE
PRIMARY THREAT...THOUGH LARGE HAIL CANNOT BE TOTALLY RULED OUT.
THERE ALSO REMAINS THE THREAT OF BRIEF TORNADOES SPINNING UP
WITHIN ANY QLCS SEGMENTS. TIMING IS LARGELY UNCHANGED...WITH THE
CONVECTION REACHING THE SAVANNAH METRO AREA RIGHT NOW AND THEN
WILL REACH THE CHARLESTON AREA AROUND 22Z-23Z.
TONIGHT...THE LINE OF CONVECTION WILL PUSH EAST OF THE AREA AND
OFFSHORE RIGHT AROUND MIDNIGHT. THEREAFTER...MODEL TIME HEIGHTS AND
SOUNDING SHOWS NOTABLE MID/UPPER LEVEL DRYING AND THE REMAINDER OF
THE NIGHT IS EXPECTED TO BE DRY. STRATUS WILL FILL IN OVERNIGHT AND
OVERCAST SKIES WILL PREVAIL. ANOTHER VERY WARM NIGHT IS
EXPECTED...WITH YET ANOTHER PERSISTENCE FORECAST FOR LOWS. THE
FORECAST FEATURES MID TO UPPER 60S AGAIN.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
THE UPSTREAM LONGWAVE TROUGH WILL PUSH A STRONG COLD FRONT TOWARD
THE REGION MONDAY. AFTER A RAIN-FREE MORNING...THE CHANCE FOR
THUNDERSTORMS WILL INCREASE DURING THE AFTERNOON. DESTABILIZATION
SUPPORTED BY FEATURING MLCAPES INCREASING TO 2000-3000 J/KG...FAIRLY
UNIDIRECTIONAL 0-6 KM BULK SHEAR 40-50 KNOTS AND SOME DYNAMIC
FORCING FOR ASCENT PROVIDED BY AN APPROACHING SHORTWAVE TROUGH
ALOFT/LARGE SCALE HEIGHT FALLS PRODUCED BY THE PARENT LONGWAVE
TROUGH WILL SUPPORT THE POTENTIAL FOR ANOTHER ROUND OF ORGANIZED
THUNDERSTORMS PRODUCING SEVERE WEATHER. DOWNDRAFT CAPES AROUND 1500
J/KG AND DRIER AIR ALOFT WILL SUPPORT DAMAGING WIND GUSTS AND EVEN
LARGE HAIL.
THUNDERSTORM COVERAGE REMAINS UNCERTAIN MONDAY AFTERNOON/EVENING.
WHILE ORGANIZED THUNDERSTORMS COULD PUSH INTO THE REGION FROM THE
WEST...STRONG THUNDERSTORMS SOUTH OF THE REGION COULD LIMIT COVERAGE
OVER THE REGION. ALSO POSSIBLE...STRONGEST THUNDERSTORMS COULD
REMAIN JUST NORTH OF THE REGION. FOR NOW...CAPPED POPS AT 50 PERCENT
OR LESS...HIGHEST INLAND/NORTH...BUT ADJUSTMENTS COULD YET BE
REQUIRED. WILL CONTINUE TO HIGHLIGHT THE SEVERE WEATHER THREAT
WITHIN THE HAZARDOUS WEATHER OUTLOOK.
THE COLD FRONT WILL CROSS THE REGION MONDAY NIGHT. THE CHANCE FOR
THE SHOWERS/THUNDERSTORMS WILL GRADUALLY WANE...AND THE POTENTIAL
FOR SEVERE WEATHER WILL ALSO DIMINISH WITH DIURNAL STABILIZATION.
MUCH DRIER HIGH PRESSURE WILL PREVAIL TUESDAY AND WEDNESDAY. HIGHS
WILL AVERAGE IN THE MID TO UPPER 70S...AND LOWS IN THE 50S WILL BE
COMMON TUESDAY NIGHT.
GUIDANCE PULLS VARYING DEGREES OF MID/HIGH LEVEL MOISTURE INTO THE
REGION WITHIN A ZONAL FLOW AHEAD OF AN APPROACHING COLD FRONT
WEDNESDAY. WHILE CLOUD COVER SHOULD INCREASE...CONVECTIVE
PRECIPITATION PRODUCED BY THE GFS APPEARS OVERDONE. THUS...HELD POPS
BELOW 15 PERCENT WITH NO MENTION OF PRECIPITATION WEDNESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
A ZONAL PATTERN WILL EXIST MUCH OF THE PERIOD. A WEAK BACK DOOR COLD
FRONT DROPS THROUGH THE AREA THURSDAY NIGHT. THE FRONT WILL STALL TO
THE SOUTH BEFORE LIFTING BACK NORTH AS A WARM FRONT FRIDAY NIGHT AND
SATURDAY. A PRONOUNCED SHORTWAVE EMBEDDED IN THE QUASI-ZONAL FLOW
WILL MOVE THROUGH SATURDAY NIGHT ACCOMPANIED BY A COLD FRONT.
PRECIPITATION POSSIBLE STARTING FRIDAY NIGHT AND CONTINUING INTO
SATURDAY NIGHT. TEMPS WILL BE MODERATED BY INCREASING CLOUD COVER
AND WEAK COLD ADVECTION.
&&
.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
MVFR CEILINGS HAVE RETURNED TO BOTH TERMINALS EARLY THIS AFTERNOON
AND THE MAIN FORECAST ISSUE THROUGH THE EVENING WILL BE TIMING
THUNDERSTORMS INTO THE FORECAST. BASED ON CURRENT RADAR TRENDS AND
HI-RES MODEL GUIDANCE...IT LOOKS LIKE THUNDER WILL REACH KSAV AND
IMPACT THE TERMINAL BETWEEN 20Z-22Z. HAVE GONE WITH IFR CONDITIONS
IN THUNDER WITH GUSTY WINDS TO ALMOST 40 KT BASED ON SOME UPSTREAM
OBSERVATIONS. AT KCHS...THUNDER WILL ARRIVE LATER AND IT IS
UNCLEAR IF IT WILL BE AS STRONG AS IT IS EXPECTED AT KSAV. HAVE
GONE WITH 22Z-00Z AT KCHS WITH IFR CONDITIONS AND SLIGHTLY LESSER
WIND GUSTS. ONCE THE CONVECTION MOVE EAST OF THE TERMINALS THERE
WILL BE A BIT OF A LULL UNTIL IFR CEILINGS ARE PROGGED TO RETURN
AFTER MIDNIGHT. BOTH SITES GET PREVAILING IFR CEILINGS THROUGH THE
LATE NIGHT...SCATTERING OUT MONDAY MORNING.
EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS WITHIN SCATTERED
SHOWERS/TSTMS POSSIBLE AT BOTH TERMINALS MONDAY AFTERNOON AND
EVENING. OTHERWISE...VFR THROUGH THE PERIOD.
&&
.MARINE...
THIS EVENING AND TONIGHT...THE MAIN FORECAST ISSUE WILL BE THE LINE
OF THUNDERSTORMS EXPECTED TO MOVE THROUGH THE LOCAL WATERS THIS
EVENING AND THE FIRST PART OF TONIGHT. THESE STORMS COULD BE QUITE
STRONG...PRODUCING 35 KT OR GREATER WINDS GUSTS...FREQUENT
LIGHTNING...AND EVEN THE POTENTIAL FOR A TORNADIC WATERSPOUT. THE
STORMS WILL IMPACT THE GEORGIA AND SOUTHERN SOUTH CAROLINA WATERS
THROUGH ABOUT 10 PM...AND THEN MOVE OFF THE CHARLESTON COUNTY WATERS
JUST AFTER MIDNIGHT. OTHERWISE...SOUTHERLY FLOW WILL PREVAIL AND
THEN TURN MORE SOUTHWESTERLY LATE. OUTSIDE OF CONVECTION WINDS WILL
TOP OUT IN THE 15-20 KT RANGE AND NO SMALL CRAFT ADVISORIES ARE
ANTICIPATED.
AHEAD OF AN APPROACHING COLD FRONT...SMALL CRAFT ADVISORY GUSTS FROM
THE SOUTHWEST ARE POSSIBLE MONDAY AND MONDAY EVENING...ESPECIALLY
ACROSS NEARSHORE WATERS. HOWEVER...SINCE THIS EVENT APPEARS
MARGINAL...OPTED NOT TO RAISE A SMALL CRAFT ADVISORY.
IN THE WAKE OF COLD FROPA...WINDS WILL SHIFT TOWARD THE NORTHWEST.
TUESDAY THROUGH FRIDAY LOOK FAIRLY QUIET OVER THE WATERS AS HIGH
PRESSURE PREVAILS.
&&
.TIDES/COASTAL FLOODING...
THERE IS A CHANCE THAT THE HIGH TIDE COULD REACH OR SLIGHTLY
EXCEED 7.0 FT MLLW ON CHARLESTON HARBOR THIS EVENING.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...BSH
SHORT TERM...SPR
LONG TERM...JRL
AVIATION...BSH/SPR
MARINE...BSH/SPR
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
147 PM EDT SUN APR 19 2015
.SYNOPSIS...
A WARM FRONT WILL LIFT INTO THE AREA TODAY...ACCOMPANIED BY AN UPPER
LEVEL DISTURBANCE. A COLD FRONT WILL APPROACH THE AREA MONDAY...
MOVING OFFSHORE MONDAY NIGHT. HIGH PRESSURE WILL BUILD IN TUESDAY
THROUGH THURSDAY. A WEAK COLD FRONT WILL DROP THROUGH THE AREA
THURSDAY NIGHT...THEN A STORM SYSTEM WILL AFFECT THE REGION NEXT
WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
EARLY THIS AFTERNOON...QUICK UPDATE TO INCLUDE TORNADO WATCH 79
WHICH IS IN EFFECT THROUGH 8 PM. NO CHANGE TO PREVIOUS FORECAST
THINKING AND PREVIOUS DISCUSSION FOLLOWS BELOW.
LATE THIS MORNING...THE WARM FRONT PRECIPITATION THAT HAD
BLOSSOMED EARLIER THIS MORNING ACROSS SOUTHEAST GEORGIA HAS
DISSIPATED PRETTY RAPIDLY AS IT LIFTS TO THE NORTHEAST. AS
SUCH...THE REST OF THE MORNING WILL BE RELATIVELY QUIET AHEAD OF
THE MAIN FORECAST PROBLEM WHICH IS THE LARGE AREA OF CONVECTION
CURRENTLY IMPACTING MUCH OF ALABAMA/GEORGIA/FLORIDA.
OVERALL...THERE WILL BE LIMITED PRECIPITATION COVERAGE OUT AHEAD
OF THE APPROACHING LINE OTHER THAN SCATTERED DISCRETE
SHOWERS/THUNDERSTORMS THAT SHOULD DEVELOP RIGHT AS THE LINE PUSHES
INTO THE WESTERN ZONES. CURRENTLY...THE RECENT RUNS OF THE HRRR
SEEMS TO HAVE AN EXCELLENT HANDLE ON THE POSITION OF THE
CONVECTION AND ITS AFTERNOON PROGRESSION SEEMS QUITE REASONABLE.
REGARDING TIMING...THE HRRR IS RUNNING ABOUT AN HOUR OR TWO ON
THE SLOW SIDE SO WE THINK THE LINE OF STORMS WILL BEGIN IMPACTING
THE WESTERN ZONES IN THE 1-2PM WINDOW. THIS WOULD PUT THE LINE
INTO THE SAVANNAH METRO AREA 3-5PM AND THEN THE CHARLESTON REGION
BETWEEN 6-8PM. THE POTENTIAL FOR SEVERE WEATHER APPEARS TO BE
INCREASING. UPSTREAM OFFICES HAVE BEEN ISSUING A MIXTURE OF
SEVERE/TORNADO WARNINGS THIS MORNING WITH A NUMBER OF WIND DAMAGE
REPORTS. BASED ON ITS LOCATION RELATIVE TO THE LINE AT 12Z...THE
TAE MORNING SOUNDING IS LIKELY THE BEST SAMPLING OF THE
APPROACHING NEAR STORM ENVIRONMENT. AS SUCH...WE EXPECT A STRONGLY
SHEARED ENVIRONMENT WITH A NICE VEERING OF THE LOW LEVEL PROFILE
AND CAPE VALUES INCREASING INTO THE 1500-2000 J/KG RANGE. IN
FACT...THE TAE SOUNDING HAS A DISTINCT ELEVATED MIXED LAYER THAT
ACTUALLY SHOWS UP WELL WHEN LOOKING AT HRRR SOUNDINGS LATER THIS
AFTERNOON. ONE OF THE MORE TROUBLING ASPECTS IS THE POTENTIAL FOR
A WINDOW OF CLEARING NOTED ON VISIBLE SATELLITE IMAGERY. AS THIS
CLEARING HAS MOVED ACROSS SOUTH GEORGIA TEMPERATURES HAVE RISEN
INTO THE UPPER 70S AND EVEN TO 80 WITHIN JUST AN HOUR. GIVEN LOW
LEVEL THICKNESS VALUES AS THEY ARE...EVEN A BRIEF PERIOD OF SUN
WILL LEAD TO A RAPID WARM UP AND INCREASE THE SURFACE
DESTABILIZATION POTENTIAL.
SO USING THE HRRR AND ITS SOUNDINGS AS THE BEST REPRESENTATION OF
THE AFTERNOON NEAR STORM ENVIRONMENT...IT APPEARS WE ARE LOOKING
AT CAPE VALUES AS HIGH AS 2500 J/KG...0-3 KM SHEAR OF 30-35
KT...AND SRH VALUES BETWEEN 150-250 THANKS TO THE SOUTHEAST
BACKED LOW LEVEL FLOW. SUCH AN ENVIRONMENT WILL LIKELY FAVOR A
CONVECTIVE MODE OF LINEAR SEGMENTS WITH EMBEDDED SUPERCELL
ELEMENTS AND EVEN THE POTENTIAL FOR A DISCRETE SUPERCELL OR TWO.
DAMAGING WIND GUSTS CONTINUES TO BE THE PRIMARY SEVERE WEATHER
THREAT...BUT THE SHEAR AND LOW LEVEL VEERING WILL ALSO PROVIDE A
TORNADO THREAT AS WELL. MUCH WILL BE DETERMINED BY HOW MUCH SUN
CAN BREAK THROUGH AND TEMPERATURES WARM. ONE OTHER POTENTIAL THING
TO WATCH IS THAT THE CURRENT SOUTHEAST WINDS COULD ADVECT IN A
SLIGHTLY MORE STABLE MARINE ENVIRONMENT. HOWEVER...GIVEN THAT WE
ARE OUT OF THE COOLEST SHELF WATER SEASON THIS IMPACT IS EXPECTED
TO BE LIMITED.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
TONIGHT...THE SHORTWAVE WILL PUSH OFF THE COAST AND ELEVATED POPS
DURING THE EVENING HOURS SHOULD DECREASE BELOW 15 PERCENT AS
SOMEWHAT DRIER AIR AND TEMPORARY SUBSIDENCE DEVELOP OVERNIGHT INTO
EARLY MONDAY. ANOTHER IN A SERIES OF VERY MILD OVERNIGHTS WITH
TEMPS ONLY FALLING TO THE MID 60S ONCE AGAIN.
THE LONGWAVE TROUGH WILL PERSIST TO OUR WEST ON MONDAY WHILE A
SERIES OF POTENT SHORTWAVES LIFT NORTHEAST THROUGH THE LOCAL
FORECAST AREA. A 145 KT SOUTHERN STREAM JET STREAK IS PROGGED TO
SLIDE ALONG THE CENTRAL GULF COAST REGION DURING THE DAY...SPREADING
A REGION OF ENHANCED UPPER LEVEL DIVERGENCE INTO SC/GA IN THE AFTERNOON.
MODEL TIME SECTIONS SHOW CONSIDERABLE DRYING ABOVE 850 MB EARLY IN
THE PERIOD...WITH PWATS DROPPING BELOW 1.25" BY MONDAY AFTERNOON.
THE MAIN COLD FRONT WILL SLOWLY MOVE EAST DURING THE DAY...CROSSING
THE REGION AT SOME POINT MONDAY EVENING. GIVEN THE DRY AIR ALOFT...
CONSIDERABLE BREAKS IN THE CLOUDS AND COMPRESSIONAL HEATING AHEAD
OF THE FRONT SHOULD HELP PUSH TEMPS INTO THE MID/UPPER 80S.
THE BIG QUESTION ON MONDAY IS HOW MUCH CONVECTIVE COVERAGE DEVELOPS.
THE DEEP DRY LAYER ABOVE THE SURFACE MAY LIMIT THE INITIAL
CONVECTIVE DEVELOPMENT. HOWEVER...MODELS ARE HINTING AT AN UPSTREAM
CONVECTIVE CLUSTER MOVING INTO WESTERN AREAS LATER IN THE AFTERNOON.
THERMODYNAMICS AND KINEMATICS ARE QUITE IMPRESSIVE ON MONDAY. 40-50
KT OF 0-6 KM BULK SHEAR...CAPES OF 1500-2000 J/KG AND DOWNDRAFT
CAPES 1000 TO 1500 J/KG. A FAIRLY ROBUST SEA BREEZE IS EXPECTED TO
DEVELOP IN THE AFTERNOON GIVEN SUCH WARM TEMPS INLAND AND PREVAILING
SOUTHERLY FLOW. THIS MAY COME INTO PLAY LATE IN THE DAY IF UPSTREAM
CONVECTION MOVES IN FROM THE WEST.
GIVEN THE SOMEWHAT DRIER TREND IN THE LATEST MODELS...WE MINIMIZED
POPS MONDAY MORNING WITH VALUES INCREASING TO 30-40% IN THE
AFTERNOON...ESPECIALLY ACROSS INTERIOR SC/GA. AS THE ACTIVITY AHEAD
OF THE FRONT MOVES THROUGH OUR AREA IT SHOULD BE GRADUALLY
WEAKENING. THEN SOME ADDITIONAL ACTIVITY...LIKELY WEAKER...COULD
ACCOMPANY THE ACTUAL FRONT LATER IN THE EVENING OR OVERNIGHT. WE
PLAN TO MAINTAIN SEVERE WEATHER POTENTIAL IN THE HAZARDOUS WEATHER
OUTLOOK.
HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT WITH DRY WEATHER AND
SEASONABLE TEMPERATURES TUESDAY AND WEDNESDAY. HIGHS WILL CLIMB TO
NEAR 80 BOTH DAYS WITH OVERNIGHT LOWS IN THE MID 50S.
&&
.LONG TERM /MONDAY THROUGH SUNDAY/...
A ZONAL PATTERN WILL EXIST MUCH OF THE PERIOD. A WEAK BACK DOOR COLD
FRONT DROPS THROUGH THE AREA THURSDAY NIGHT. THE FRONT WILL STALL TO
THE SOUTH BEFORE LIFTING BACK NORTH AS A WARM FRONT FRIDAY NIGHT AND
SATURDAY. A PRONOUNCED SHORTWAVE EMBEDDED IN THE QUASI-ZONAL FLOW
WILL MOVE THROUGH SATURDAY NIGHT ACCOMPANIED BY A COLD FRONT.
PRECIPITATION POSSIBLE STARTING FRIDAY NIGHT AND CONTINUING INTO
SATURDAY NIGHT. TEMPS WILL BE MODERATED BY INCREASING CLOUD COVER
AND WEAK COLD ADVECTION.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
MVFR CEILINGS HAVE RETURNED TO BOTH TERMINALS EARLY THIS AFTERNOON
AND THE MAIN FORECAST ISSUE THROUGH THE EVENING WILL BE TIMING
THUNDERSTORMS INTO THE FORECAST. BASED ON CURRENT RADAR TRENDS AND
HI-RES MODEL GUIDANCE...IT LOOKS LIKE THUNDER WILL REACH KSAV AND
IMPACT THE TERMINAL BETWEEN 20Z-22Z. HAVE GONE WITH IFR CONDITIONS
IN THUNDER WITH GUSTY WINDS TO ALMOST 40 KT BASED ON SOME UPSTREAM
OBSERVATIONS. AT KCHS...THUNDER WILL ARRIVE LATER AND IT IS
UNCLEAR IF IT WILL BE AS STRONG AS IT IS EXPECTED AT KSAV. HAVE
GONE WITH 22Z-00Z AT KCHS WITH IFR CONDITIONS AND SLIGHTLY LESSER
WIND GUSTS. ONCE THE CONVECTION MOVE EAST OF THE TERMINALS THERE
WILL BE A BIT OF A LULL UNTIL IFR CEILINGS ARE PROGGED TO RETURN
AFTER MIDNIGHT. BOTH SITES GET PREVAILING IFR CEILINGS THROUGH THE
LATE NIGHT...SCATTERING OUT MONDAY MORNING.
EXTENDED AVIATION OUTLOOK...SCATTERED SHOWERS/TSTMS EXPECTED AT BOTH
TERMINALS MONDAY AFTERNOON AND EVENING WITH BRIEF MVFR CEILING/VSBY
RESTRICTIONS POSSIBLE. OTHERWISE VFR CONDITIONS EXPECTED.
&&
.MARINE...
A WARM FRONT WILL LIFT THROUGH THE WATERS TODAY...FOLLOWED BY
INTENSIFYING SOUTH/SOUTHWEST FLOW. LIGHT AND VARIABLE WINDS EARLY
THIS MORNING WILL BECOME SE PRIOR TO THE WARM FRONT WHICH WILL
SHIFT FLOW SW TO S TONIGHT. WHILE SPEEDS INCREASE TONIGHT AND SEAS
SLOWLY BUILD...THE AVERAGE SPEED COULD REACH ONLY 15 KT BY
DAYBREAK OVER NEAR SHORE WATERS WITH SEAS 3 TO 4 FT.
THE POTENTIAL EXISTS FOR THUNDERSTORMS WITH STRONG WINDS OVER THE
WATERS THIS AFTERNOON EVENING. VERY HEAVY DOWNPOURS REDUCING
LOCAL VSBYS BELOW 1 NM ARE ALSO POSSIBLE WITH THE STRONGEST
STORMS MOVING OFFSHORE LATE IN THE DAY AND EARLY THIS EVENING.
A PREVAILING SSW FLOW WILL EXIST MONDAY MORNING AS A COLD FRONT
APPROACHES FROM THE WEST. THE GRADIENT WILL STRENGTHEN DURING THE
AFTERNOON...ESPECIALLY ALONG THE COAST WHERE A STRONG SEA BREEZE
DEVELOPS DUE TO MID/UPPER 80S TEMPS OVER LAND. THE LATEST GFS AND
NAM MOS AT FOLLY BEACH SC SHOW SFC WINDS EXCEEDING 20 KT LATE MONDAY
AFTERNOON WHEN THE SEA BREEZE IS STRONGEST. THIS SEEMS FAIRLY
REASONABLE GIVEN THE PATTERN AND THE WARMER INLAND TEMPS EXPECTED. A
SMALL CRAFT ADVISORY MAY EVENTUALLY BE REQUIRED FOR CHARLESTON
HARBOR MONDAY AFTERNOON FOR WINDS/GUSTS IN THE 20-30 KT RANGE.
A BRIEF PERIOD OF SMALL CRAFT ADVISORY CONDITIONS MAY DEVELOP OVER
OFFSHORE WATERS MONDAY NIGHT AS THE COLD FRONT MOVES THROUGH AND
WINDS GUST TO 25 KT WITH SOME 6 FT SEAS ALSO POSSIBLE.
TUESDAY THROUGH FRIDAY LOOK FAIRLY QUIET OVER THE WATERS AS HIGH
PRESSURE PREVAILS.
&&
.TIDES/COASTAL FLOODING...
THERE IS A CHANCE THAT THE HIGH TIDE COULD REACH OR SLIGHTLY
EXCEED 7.0 FT MLLW ON CHARLESTON HARBOR THIS EVENING.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...BSH
SHORT TERM...JRL
LONG TERM...JRL
AVIATION...BSH
MARINE...JRL
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
1121 AM EDT SUN APR 19 2015
.SYNOPSIS...
A WARM FRONT WILL LIFT INTO THE AREA TODAY...ACCOMPANIED BY AN UPPER
LEVEL DISTURBANCE. A COLD FRONT WILL APPROACH THE AREA MONDAY...
MOVING OFFSHORE MONDAY NIGHT. HIGH PRESSURE WILL BUILD IN TUESDAY
THROUGH THURSDAY. A WEAK COLD FRONT WILL DROP THROUGH THE AREA
THURSDAY NIGHT...THEN A STORM SYSTEM WILL AFFECT THE REGION NEXT
WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATE THIS MORNING...THE WARM FRONT PRECIPITATION THAT HAD
BLOSSOMED EARLIER THIS MORNING ACROSS SOUTHEAST GEORGIA HAS
DISSIPATED PRETTY RAPIDLY AS IT LIFTS TO THE NORTHEAST. AS
SUCH...THE REST OF THE MORNING WILL BE RELATIVELY QUIET AHEAD OF
THE MAIN FORECAST PROBLEM WHICH IS THE LARGE AREA OF CONVECTION
CURRENTLY IMPACTING MUCH OF ALABAMA/GEORGIA/FLORIDA.
OVERALL...THERE WILL BE LIMITED PRECIPITATION COVERAGE OUT AHEAD
OF THE APPROACHING LINE OTHER THAN SCATTERED DISCRETE
SHOWERS/THUNDERSTORMS THAT SHOULD DEVELOP RIGHT AS THE LINE PUSHES
INTO THE WESTERN ZONES. CURRENTLY...THE RECENT RUNS OF THE HRRR
SEEMS TO HAVE AN EXCELLENT HANDLE ON THE POSITION OF THE
CONVECTION AND ITS AFTERNOON PROGRESSION SEEMS QUITE REASONABLE.
REGARDING TIMING...THE HRRR IS RUNNING ABOUT AN HOUR OR TWO ON
THE SLOW SIDE SO WE THINK THE LINE OF STORMS WILL BEGIN IMPACTING
THE WESTERN ZONES IN THE 1-2PM WINDOW. THIS WOULD PUT THE LINE
INTO THE SAVANNAH METRO AREA 3-5PM AND THEN THE CHARLESTON REGION
BETWEEN 6-8PM. THE POTENTIAL FOR SEVERE WEATHER APPEARS TO BE
INCREASING. UPSTREAM OFFICES HAVE BEEN ISSUING A MIXTURE OF
SEVERE/TORNADO WARNINGS THIS MORNING WITH A NUMBER OF WIND DAMAGE
REPORTS. BASED ON ITS LOCATION RELATIVE TO THE LINE AT 12Z...THE
TAE MORNING SOUNDING IS LIKELY THE BEST SAMPLING OF THE
APPROACHING NEAR STORM ENVIRONMENT. AS SUCH...WE EXPECT A STRONGLY
SHEARED ENVIRONMENT WITH A NICE VEERING OF THE LOW LEVEL PROFILE
AND CAPE VALUES INCREASING INTO THE 1500-2000 J/KG RANGE. IN
FACT...THE TAE SOUNDING HAS A DISTINCT ELEVATED MIXED LAYER THAT
ACTUALLY SHOWS UP WELL WHEN LOOKING AT HRRR SOUNDINGS LATER THIS
AFTERNOON. ONE OF THE MORE TROUBLING ASPECTS IS THE POTENTIAL FOR
A WINDOW OF CLEARING NOTED ON VISIBLE SATELLITE IMAGERY. AS THIS
CLEARING HAS MOVED ACROSS SOUTH GEORGIA TEMPERATURES HAVE RISEN
INTO THE UPPER 70S AND EVEN TO 80 WITHIN JUST AN HOUR. GIVEN LOW
LEVEL THICKNESS VALUES AS THEY ARE...EVEN A BRIEF PERIOD OF SUN
WILL LEAD TO A RAPID WARM UP AND INCREASE THE SURFACE
DESTABILIZATION POTENTIAL.
SO USING THE HRRR AND ITS SOUNDINGS AS THE BEST REPRESENTATION OF
THE AFTERNOON NEAR STORM ENVIRONMENT...IT APPEARS WE ARE LOOKING
AT CAPE VALUES AS HIGH AS 2500 J/KG...0-3 KM SHEAR OF 30-35
KT...AND SRH VALUES BETWEEN 150-250 THANKS TO THE SOUTHEAST
BACKED LOW LEVEL FLOW. SUCH AN ENVIRONMENT WILL LIKELY FAVOR A
CONVECTIVE MODE OF LINEAR SEGMENTS WITH EMBEDDED SUPERCELL
ELEMENTS AND EVEN THE POTENTIAL FOR A DISCRETE SUPERCELL OR TWO.
DAMAGING WIND GUSTS CONTINUES TO BE THE PRIMARY SEVERE WEATHER
THREAT...BUT THE SHEAR AND LOW LEVEL VEERING WILL ALSO PROVIDE A
TORNADO THREAT AS WELL. MUCH WILL BE DETERMINED BY HOW MUCH SUN
CAN BREAK THROUGH AND TEMPERATURES WARM. ONE OTHER POTENTIAL THING
TO WATCH IS THAT THE CURRENT SOUTHEAST WINDS COULD ADVECT IN A
SLIGHTLY MORE STABLE MARINE ENVIRONMENT. HOWEVER...GIVEN THAT WE
ARE OUT OF THE COOLEST SHELF WATER SEASON THIS IMPACT IS EXPECTED
TO BE LIMITED.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
TONIGHT...THE SHORTWAVE WILL PUSH OFF THE COAST AND ELEVATED POPS
DURING THE EVENING HOURS SHOULD DECREASE BELOW 15 PERCENT AS
SOMEWHAT DRIER AIR AND TEMPORARY SUBSIDENCE DEVELOP OVERNIGHT INTO
EARLY MONDAY. ANOTHER IN A SERIES OF VERY MILD OVERNIGHTS WITH
TEMPS ONLY FALLING TO THE MID 60S ONCE AGAIN.
THE LONGWAVE TROUGH WILL PERSIST TO OUR WEST ON MONDAY WHILE A
SERIES OF POTENT SHORTWAVES LIFT NORTHEAST THROUGH THE LOCAL
FORECAST AREA. A 145 KT SOUTHERN STREAM JET STREAK IS PROGGED TO
SLIDE ALONG THE CENTRAL GULF COAST REGION DURING THE DAY...SPREADING
A REGION OF ENHANCED UPPER LEVEL DIVERGENCE INTO SC/GA IN THE AFTERNOON.
MODEL TIME SECTIONS SHOW CONSIDERABLE DRYING ABOVE 850 MB EARLY IN
THE PERIOD...WITH PWATS DROPPING BELOW 1.25" BY MONDAY AFTERNOON.
THE MAIN COLD FRONT WILL SLOWLY MOVE EAST DURING THE DAY...CROSSING
THE REGION AT SOME POINT MONDAY EVENING. GIVEN THE DRY AIR ALOFT...
CONSIDERABLE BREAKS IN THE CLOUDS AND COMPRESSIONAL HEATING AHEAD
OF THE FRONT SHOULD HELP PUSH TEMPS INTO THE MID/UPPER 80S.
THE BIG QUESTION ON MONDAY IS HOW MUCH CONVECTIVE COVERAGE DEVELOPS.
THE DEEP DRY LAYER ABOVE THE SURFACE MAY LIMIT THE INITIAL
CONVECTIVE DEVELOPMENT. HOWEVER...MODELS ARE HINTING AT AN UPSTREAM
CONVECTIVE CLUSTER MOVING INTO WESTERN AREAS LATER IN THE AFTERNOON.
THERMODYNAMICS AND KINEMATICS ARE QUITE IMPRESSIVE ON MONDAY. 40-50
KT OF 0-6 KM BULK SHEAR...CAPES OF 1500-2000 J/KG AND DOWNDRAFT
CAPES 1000 TO 1500 J/KG. A FAIRLY ROBUST SEA BREEZE IS EXPECTED TO
DEVELOP IN THE AFTERNOON GIVEN SUCH WARM TEMPS INLAND AND PREVAILING
SOUTHERLY FLOW. THIS MAY COME INTO PLAY LATE IN THE DAY IF UPSTREAM
CONVECTION MOVES IN FROM THE WEST.
GIVEN THE SOMEWHAT DRIER TREND IN THE LATEST MODELS...WE MINIMIZED
POPS MONDAY MORNING WITH VALUES INCREASING TO 30-40% IN THE
AFTERNOON...ESPECIALLY ACROSS INTERIOR SC/GA. AS THE ACTIVITY AHEAD
OF THE FRONT MOVES THROUGH OUR AREA IT SHOULD BE GRADUALLY
WEAKENING. THEN SOME ADDITIONAL ACTIVITY...LIKELY WEAKER...COULD
ACCOMPANY THE ACTUAL FRONT LATER IN THE EVENING OR OVERNIGHT. WE
PLAN TO MAINTAIN SEVERE WEATHER POTENTIAL IN THE HAZARDOUS WEATHER
OUTLOOK.
HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT WITH DRY WEATHER AND
SEASONABLE TEMPERATURES TUESDAY AND WEDNESDAY. HIGHS WILL CLIMB TO
NEAR 80 BOTH DAYS WITH OVERNIGHT LOWS IN THE MID 50S.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
A ZONAL PATTERN WILL EXIST MUCH OF THE PERIOD. A WEAK BACK DOOR COLD
FRONT DROPS THROUGH THE AREA THURSDAY NIGHT. THE FRONT WILL STALL TO
THE SOUTH BEFORE LIFTING BACK NORTH AS A WARM FRONT FRIDAY NIGHT AND
SATURDAY. A PRONOUNCED SHORTWAVE EMBEDDED IN THE QUASI-ZONAL FLOW
WILL MOVE THROUGH SATURDAY NIGHT ACCOMPANIED BY A COLD FRONT.
PRECIPITATION POSSIBLE STARTING FRIDAY NIGHT AND CONTINUING INTO
SATURDAY NIGHT. TEMPS WILL BE MODERATED BY INCREASING CLOUD COVER
AND WEAK COLD ADVECTION.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
DEEP MOISTURE ACROSS THE TAF CORRIDOR TODAY. LAYERED CLOUDS THIS
MORNING DIFFICULT TO PIN DOWN AS RECENTLY LOW STRATUS DECKS DEVELOPED
IN THE WARM FRONTAL ZONE DEVELOPING ACROSS THE REGION. MODELS
INDICATE THAT IFR/LIFR CIGS AND IFR VSBYS SHOULD BE CONFINED TO
THE MORNING HOURS WITH MVFR TO VFR CIGS DEVELOPING IN A BIT OF A
DRIER SLOT THIS AFTERNOON AHEAD OF CONVECTION THAT SHOULD SWEEP
THROUGH THE TERMINALS IN THE 19Z TO 00Z TIME FRAME. TSTMS ARE
POSSIBLE WITH HEAVY DOWNPOURS AND PERHAPS GUSTY AND SHIFTING
WINDS. MAINLY VFR TONIGHT BUT MVFR/IFR CIGS ARE POSSIBLE LATE.
EXTENDED AVIATION OUTLOOK...SCATTERED SHOWERS/TSTMS EXPECTED AT BOTH
TERMINALS MONDAY AFTERNOON AND EVENING WITH BRIEF MVFR CEILING/VSBY
RESTRICTIONS POSSIBLE. OTHERWISE VFR CONDITIONS EXPECTED.
&&
.MARINE...
A WARM FRONT WILL LIFT THROUGH THE WATERS TODAY...FOLLOWED BY
INTENSIFYING SOUTH/SOUTHWEST FLOW. LIGHT AND VARIABLE WINDS EARLY
THIS MORNING WILL BECOME SE PRIOR TO THE WARM FRONT WHICH WILL
SHIFT FLOW SW TO S TONIGHT. WHILE SPEEDS INCREASE TONIGHT AND SEAS
SLOWLY BUILD...THE AVERAGE SPEED COULD REACH ONLY 15 KT BY
DAYBREAK OVER NEAR SHORE WATERS WITH SEAS 3 TO 4 FT.
THE POTENTIAL EXISTS FOR THUNDERSTORMS WITH STRONG WINDS OVER THE
WATERS THIS AFTERNOON EVENING. VERY HEAVY DOWNPOURS REDUCING
LOCAL VSBYS BELOW 1 NM ARE ALSO POSSIBLE WITH THE STRONGEST
STORMS MOVING OFFSHORE LATE IN THE DAY AND EARLY THIS EVENING.
A PREVAILING SSW FLOW WILL EXIST MONDAY MORNING AS A COLD FRONT
APPROACHES FROM THE WEST. THE GRADIENT WILL STRENGTHEN DURING THE
AFTERNOON...ESPECIALLY ALONG THE COAST WHERE A STRONG SEA BREEZE
DEVELOPS DUE TO MID/UPPER 80S TEMPS OVER LAND. THE LATEST GFS AND
NAM MOS AT FOLLY BEACH SC SHOW SFC WINDS EXCEEDING 20 KT LATE MONDAY
AFTERNOON WHEN THE SEA BREEZE IS STRONGEST. THIS SEEMS FAIRLY
REASONABLE GIVEN THE PATTERN AND THE WARMER INLAND TEMPS EXPECTED. A
SMALL CRAFT ADVISORY MAY EVENTUALLY BE REQUIRED FOR CHARLESTON
HARBOR MONDAY AFTERNOON FOR WINDS/GUSTS IN THE 20-30 KT RANGE.
A BRIEF PERIOD OF SMALL CRAFT ADVISORY CONDITIONS MAY DEVELOP OVER
OFFSHORE WATERS MONDAY NIGHT AS THE COLD FRONT MOVES THROUGH AND
WINDS GUST TO 25 KT WITH SOME 6 FT SEAS ALSO POSSIBLE.
TUESDAY THROUGH FRIDAY LOOK FAIRLY QUIET OVER THE WATERS AS HIGH
PRESSURE PREVAILS.
&&
.TIDES/COASTAL FLOODING...
THERE IS A CHANCE THAT THE HIGH TIDE COULD REACH OR SLIGHTLY
EXCEED 7.0 FT MLLW ON CHARLESTON HARBOR THIS EVENING.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...BSH
SHORT TERM...JRL
LONG TERM...JRL
AVIATION...
MARINE...JRL
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
508 PM CDT SUN APR 19 2015
.SHORT TERM...
319 PM CDT
THROUGH MONDAY NIGHT...
AFTER ANOTHER WARM EARLY AFTERNOON ACROSS MUCH OF THE REGION RAIN IS
BEGINNING TO SPREAD NORTHWARD ACROSS SOUTHERN SECTIONS OF THE CHICAGO
METRO AREA AS OF THIS WRITING. THIS ACTIVITY WILL CONTINUE TO
OVERSPREAD THE REGION THROUGH THE AFTERNOON AND EVENING...WITH
TEMPERATURES LIKELY TO DROP BACK INTO THE UPPER 50S AND LOW 60S IN
THE RAIN.
THE MID-LEVEL DISTURBANCE...AND THE ASSOCIATED SURFACE SYSTEM WILL
QUICKLY SHIFT NORTHWARD OVER LOWER MICHIGAN OVERNIGHT...AND IT
APPEARS THAT THE RAIN WILL BECOME MORE SHOWERY AND INTERMITTENT OR
POSSIBLY JUST SOME DRIZZLE LATER THIS EVENING AND INTO THE EARLY
MORNING ACROSS MUCH OF THE AREA AS THIS INITIAL MID LEVEL
DISTURBANCE SHIFTS NORTH OF THE AREA AND SOME DRIER MID LEVEL AIR
SHIFTS OVER THE SOUTHEASTERN HALF OF MY AREA. SOME ADDITIONAL RAIN
SHOWERS ARE POSSIBLE AGAIN EARLY MONDAY WITHIN A REGION OF MID LEVEL
DEFORMATION AND RAP AROUND MOISTURE ASSOCIATED WITH THE DEEPENING
LOWER AND MID LEVEL LOW OVER THE UPPER GREAT LAKES REGION AND
SOUTHERN CANADA.
CONDITIONS SHOULD DRY OUT MONDAY AFTERNOON...WITH ONLY A SMALL
CHANCE OF AN ADDITIONAL SHOWER DEVELOPING AS COLDER AIR ALOFT
STEEPENS THE LOWER LEVEL LAPSE RATES. THE MAIN STORY DURING THE
AFTERNOON WILL BE THE WINDS. WINDS ARE EXPECTED TO INCREASE OUT OF
THE WEST-NORTHWEST DURING THE DAY AS STOUT SURFACE PRESSURE
GRADIENT SETS UP OVER THE REGION AS THE SURFACE LOW DEEPENS TO
AROUND 985 MB ACROSS ONTARIO MONDAY AFTERNOON. MODEL SOUNDINGS
SUGGEST GOOD AFTERNOON MIXING TO AROUND 850 MB SHOULD ALLOW FOR
GUSTS OF AROUND 30 KT AT TIMES...ESPECIALLY DURING THE AFTERNOON.
THESE WIND GUSTS SHOULD ABATE MONDAY EVENING...BUT STRONG WINDS
LOOK TO DEVELOP AGAIN ON TUESDAY. SEE LONG TERM DISCUSSION FOR
MORE INFO ON TUESDAY`S WINDS.
KJB
&&
.LONG TERM...
319 PM CDT
TUESDAY THROUGH SUNDAY...
MAIN FORECAST CONCERNS/CHALLENGES ARE WITH BELOW NORMAL TEMPS
THROUGH THE FORECAST.
LARGE UPPER LEVEL CENTER WILL BE CENTERED ACROSS THE REGION AT THE
START OF THE PERIOD...AND REMAIN SITUATED THROUGH MUCH OF THE WORK
WEEK AS IT SLOWLY MOVES EAST. SEVERAL VORT LOBES ARE ANTICIPATED TO
WRAP AROUND THIS UPPER LEVEL LOW ON TUESDAY AND WITH STEEPENING
LAPSE RATES...EXPECT SKY COVER TO INCREASE THROUGH THE DAY WHILE
SCATTERED SHOWERS BECOME POSSIBLE...ESPECIALLY ACROSS NORTHERN
ILLINOIS. AS THIS OCCURS...LIKELY DEEP MIXING WITH STRONG FLOW ALOFT
WILL ALLOW FOR ANOTHER WINDY DAY. GUIDANCE IS SUGGESTING THAT
ADVISORY CONDITIONS COULD BE REACHED IN THE AFTERNOON...AND WILL
NEED TO CONTINUE MONITORING THIS POTENTIAL. ANY REMAINING PRECIP AND
CLOUD COVER SHOULD EXIT THE AREA TUESDAY NIGHT WITH DRY CONDITIONS
EXPECTED. SOME GUIDANCE DEVELOPS A SWATH OF PRECIP OVER THE CWA LATE
IN THE NIGHT INTO EARLY WEDNESDAY. HOWEVER...A MORE LIKELY SCENARIO
AT THIS TIME WOULD BE FOR DRY CONDITIONS AND SO HAVE LEFT OUT ANY
POPS AT THIS TIME. ONGOING CAA WILL MAKE FOR CHILLY CONDITIONS
TUESDAY NIGHT...WITH LOW TEMPS IN THE 30S. IF PRECIP WERE TO OCCUR
DURING THIS PERIOD...THESE COLDER CONDITIONS COULD SUPPORT THE
POTENTIAL FOR AT LEAST A RAIN SNOW MIX ACROSS NORTHERN ILLINOIS.
EXPECT DRY CONDITIONS WITH BELOW NORMAL TEMPS THROUGH THE REST OF
THE FORECAST PERIOD...WITH FORECAST HIGHS IN THE 50S. COLD NIGHT
TIME LOWS IN THE 30S COULD BECOME AN ISSUE LATE IN THE WORK WEEK AS
HIGH PRESSURE IS ANTICIPATED TO MOVE OVERHEAD...WITH LIGHTER WINDS
AND THE COLD TEMPS POSSIBLY CREATING A SETUP FOR FROST.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* EAST TO NORTHEAST WINDS AROUND 10 KT THROUGH MID EVENING.
* LIGHT TO MODERATE RAIN THROUGH MID-EVENING THEN BECOMING MORE
SHOWERY.
* QUICKLY LOWERING CIGS THROUGH SUNDOWN THEN GRADUALLY LOWERING
THROUGH IFR CATEGORY...POSSIBLY EVEN TO LIFR BY 03Z.
* GRADUALLY LOWERING VISIBILITY THROUGH THIS EVENING WITH IFR
VISIBILITY LIKELY PREVAILING BY MID EVENING.
* ANOTHER ROUND OF -SHRA PROBABLE EARLY MONDAY MORNING.
* GUSTY WEST WINDS WITH MAX GUSTS ARND 30 KT MONDAY AFTN.
MTF/JEE
//DISCUSSION...UPDATED 18Z...
RAIN IS SLOWLY PUSHING NORTH AND IS JUST SOUTH OF I-80 AT THIS
TIME. MVFR AND LOWER CIGS ARE OVER CENTRAL AND SOUTHERN IL AND
INDIANA BUT ALSO PUSHING NORTH. ADJUSTED PRECIP AND CIG TIMING
BASED ON RADAR AND SATELLITE TRENDS. MVFR VSBY WILL BE TIED TO THE
HEAVIER RAIN SHOWERS...AND CIGS WILL LOWER TO MVFR LATE THIS AFTN
AND THEN TO IFR THIS EVENING. ALL GUIDANCE MEMBERS SHOW IFR CIGS
ACROSS THE TERMINALS.
WILL EITHER SEE SCATTERED SHOWERS OR A BREAK IN RAIN AFTER
MIDNIGHT TONIGHT WITH ANOTHER ROUND OF RAIN PUSHING WEST TO EAST
EARLY MONDAY MORNING.
EAST WINDS BCM NORTHEAST ARND 10 KT LATE THIS AFTN AND BACK TO NW
BY 03Z. WINDS CONTINUE TO BACK TO WEST BY EARLY MONDAY MORNING.
GUSTY WINDS FOLLOW THE BAND OF RAIN SHOWERS...WITH 20G30KT
EXPECTED BY MONDAY AFTERNOON. THINKING THE GUSTY WINDS AND DRIER
AIR WILL HELP CIGS LIFT LATE MONDAY MORNING AND AFTN...BUT HAVE
MEDIUM CONFIDENCE IN HOW QUICKLY CIGS LIFT TO VFR.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* MEDIUM-HIGH IN WINDS.
* HIGH IN RAIN TIMING.
* MEDIUM-HIGH IN IFR CIG TIMING AND MEDIUM IN VISIBILITY TIMING.
* HIGH IN IFR CIG DURATION. LOW-MEDIUM IN IFR VISIBILITY DURATION.
MTF/JEE
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...MVFR BECOMING VFR.
TUESDAY...SLGT CHANCE PM SHRA...BUT MAINLY VFR. GUSTY WEST WINDS.
WEDNESDAY...SLGT CHANCE SHRA. MAINLY VFR. WEST-NORTHWEST WINDS.
THURSDAY...VFR. NORTH-NORTHEAST WINDS.
FRIDAY...MAINLY VFR. CHC PM SHRA.
SATURDAY...MAINLY VFR.
BEACHLER
&&
.MARINE...
324 PM CDT
AS A TROUGH OF LOW PRESSURE AND SECONDARY LOW PRESSURE CENTER
MOVE ACROSS THE GREAT LAKES REGION TONIGHT...WINDS WILL LIKELY BE
VARIABLE AT TIMES. THIS WILL ESPECIALLY BE THE CASE OVER THE
SOUTHERN HALF OF THE LAKE WHERE THE LOW PRESSURE SYSTEM IS
EXPECTED TO MOVE THROUGH. IN THE NEAR TERM...EAST NORTHEAST WINDS
WILL PREVAIL OVER THE LAKE WITH THE HIGHEST SPEEDS TO 30 KT
OCCURRING OVER THE NORTHERN HALF AND WHILE 15 TO 25 KT WINDS ARE
BEING OBSERVED OVER THE SOUTH...WITH SPEEDS EXPECTED TO SLIGHTLY
DIMINISH TONIGHT. AS THIS TROUGH/LOW EXIT TO THE EAST ON
MONDAY...STRONGER WESTERLY WINDS WILL DEVELOP. HIGHEST WINDS TO 30
KT WILL OCCUR ALONG THE NEARSHORE WATERS WHILE ONLY 15 TO 25 KT
ARE LIKELY OVER THE OPEN WATERS. A SIMILAR SETUP IS EXPECTED ON
TUESDAY BUT WITH SPEEDS SLIGHTLY HIGHER...AS TO 30 KT WILL LIKELY
PREVAIL FOR BOTH LOCATIONS AND WITH EVEN GALES POSSIBLE ALONG THE
NEARSHORE WATERS DURING THE DAY.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...11 AM MONDAY TO 9 PM MONDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
325 PM CDT SUN APR 19 2015
.SHORT TERM...
319 PM CDT
THROUGH MONDAY NIGHT...
AFTER ANOTHER WARM EARLY AFTERNOON ACROSS MUCH OF THE REGION RAIN IS
BEGINNING TO SPREAD NORTHWARD ACROSS SOUTHERN SECTIONS OF THE CHICAGO
METRO AREA AS OF THIS WRITING. THIS ACTIVITY WILL CONTINUE TO
OVERSPREAD THE REGION THROUGH THE AFTERNOON AND EVENING...WITH
TEMPERATURES LIKELY TO DROP BACK INTO THE UPPER 50S AND LOW 60S IN
THE RAIN.
THE MID-LEVEL DISTURBANCE...AND THE ASSOCIATED SURFACE SYSTEM WILL
QUICKLY SHIFT NORTHWARD OVER LOWER MICHIGAN OVERNIGHT...AND IT
APPEARS THAT THE RAIN WILL BECOME MORE SHOWERY AND INTERMITTENT OR
POSSIBLY JUST SOME DRIZZLE LATER THIS EVENING AND INTO THE EARLY
MORNING ACROSS MUCH OF THE AREA AS THIS INITIAL MID LEVEL
DISTURBANCE SHIFTS NORTH OF THE AREA AND SOME DRIER MID LEVEL AIR
SHIFTS OVER THE SOUTHEASTERN HALF OF MY AREA. SOME ADDITIONAL RAIN
SHOWERS ARE POSSIBLE AGAIN EARLY MONDAY WITHIN A REGION OF MID LEVEL
DEFORMATION AND RAP AROUND MOISTURE ASSOCIATED WITH THE DEEPENING
LOWER AND MID LEVEL LOW OVER THE UPPER GREAT LAKES REGION AND
SOUTHERN CANADA.
CONDITIONS SHOULD DRY OUT MONDAY AFTERNOON...WITH ONLY A SMALL
CHANCE OF AN ADDITIONAL SHOWER DEVELOPING AS COLDER AIR ALOFT
STEEPENS THE LOWER LEVEL LAPSE RATES. THE MAIN STORY DURING THE
AFTERNOON WILL BE THE WINDS. WINDS ARE EXPECTED TO INCREASE OUT OF
THE WEST-NORTHWEST DURING THE DAY AS STOUT SURFACE PRESSURE
GRADIENT SETS UP OVER THE REGION AS THE SURFACE LOW DEEPENS TO
AROUND 985 MB ACROSS ONTARIO MONDAY AFTERNOON. MODEL SOUNDINGS
SUGGEST GOOD AFTERNOON MIXING TO AROUND 850 MB SHOULD ALLOW FOR
GUSTS OF AROUND 30 KT AT TIMES...ESPECIALLY DURING THE AFTERNOON.
THESE WIND GUSTS SHOULD ABATE MONDAY EVENING...BUT STRONG WINDS
LOOK TO DEVELOP AGAIN ON TUESDAY. SEE LONG TERM DISCUSSION FOR
MORE INFO ON TUESDAY`S WINDS.
KJB
&&
.LONG TERM...
319 PM CDT
TUESDAY THROUGH SUNDAY...
MAIN FORECAST CONCERNS/CHALLENGES ARE WITH BELOW NORMAL TEMPS
THROUGH THE FORECAST.
LARGE UPPER LEVEL CENTER WILL BE CENTERED ACROSS THE REGION AT THE
START OF THE PERIOD...AND REMAIN SITUATED THROUGH MUCH OF THE WORK
WEEK AS IT SLOWLY MOVES EAST. SEVERAL VORT LOBES ARE ANTICIPATED TO
WRAP AROUND THIS UPPER LEVEL LOW ON TUESDAY AND WITH STEEPENING
LAPSE RATES...EXPECT SKY COVER TO INCREASE THROUGH THE DAY WHILE
SCATTERED SHOWERS BECOME POSSIBLE...ESPECIALLY ACROSS NORTHERN
ILLINOIS. AS THIS OCCURS...LIKELY DEEP MIXING WITH STRONG FLOW ALOFT
WILL ALLOW FOR ANOTHER WINDY DAY. GUIDANCE IS SUGGESTING THAT
ADVISORY CONDITIONS COULD BE REACHED IN THE AFTERNOON...AND WILL
NEED TO CONTINUE MONITORING THIS POTENTIAL. ANY REMAINING PRECIP AND
CLOUD COVER SHOULD EXIT THE AREA TUESDAY NIGHT WITH DRY CONDITIONS
EXPECTED. SOME GUIDANCE DEVELOPS A SWATH OF PRECIP OVER THE CWA LATE
IN THE NIGHT INTO EARLY WEDNESDAY. HOWEVER...A MORE LIKELY SCENARIO
AT THIS TIME WOULD BE FOR DRY CONDITIONS AND SO HAVE LEFT OUT ANY
POPS AT THIS TIME. ONGOING CAA WILL MAKE FOR CHILLY CONDITIONS
TUESDAY NIGHT...WITH LOW TEMPS IN THE 30S. IF PRECIP WERE TO OCCUR
DURING THIS PERIOD...THESE COLDER CONDITIONS COULD SUPPORT THE
POTENTIAL FOR AT LEAST A RAIN SNOW MIX ACROSS NORTHERN ILLINOIS.
EXPECT DRY CONDITIONS WITH BELOW NORMAL TEMPS THROUGH THE REST OF
THE FORECAST PERIOD...WITH FORECAST HIGHS IN THE 50S. COLD NIGHT
TIME LOWS IN THE 30S COULD BECOME AN ISSUE LATE IN THE WORK WEEK AS
HIGH PRESSURE IS ANTICIPATED TO MOVE OVERHEAD...WITH LIGHTER WINDS
AND THE COLD TEMPS POSSIBLY CREATING A SETUP FOR FROST.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* EAST WINDS ARND 10 KT BCMG NORTH LESS THAN 10 KT THIS EVENING.
* RAIN MOVING IN OVER THE NEXT 1-2 HOURS WITH MVFR VSBY. COULD
HAVE PERIODS OF IFR VSBY WITH HEAVIEST SHOWERS.
* CIGS LOWER TO IFR LATE THIS AFTN THROUGH EARLY MONDAY MORNING.
* SCATTERED SHOWERS OVERNIGHT WITH ANOTHER ROUND OF -SHRA EARLY
MONDAY MORNING.
* GUSTY WEST WINDS WITH MAX GUSTS ARND 30 KT MONDAY AFTN.
JEE
//DISCUSSION...UPDATED 18Z...
RAIN IS SLOWLY PUSHING NORTH AND IS JUST SOUTH OF I-80 AT THIS
TIME. MVFR AND LOWER CIGS ARE OVER CENTRAL AND SOUTHERN IL AND
INDIANA BUT ALSO PUSHING NORTH. ADJUSTED PRECIP AND CIG TIMING
BASED ON RADAR AND SATELLITE TRENDS. MVFR VSBY WILL BE TIED TO THE
HEAVIER RAIN SHOWERS...AND CIGS WILL LOWER TO MVFR LATE THIS AFTN
AND THEN TO IFR THIS EVENING. ALL GUIDANCE MEMBERS SHOW IFR CIGS
ACROSS THE TERMINALS.
WILL EITHER SEE SCATTERED SHOWERS OR A BREAK IN RAIN AFTER
MIDNIGHT TONIGHT WITH ANOTHER ROUND OF RAIN PUSHING WEST TO EAST
EARLY MONDAY MORNING.
EAST WINDS BCM NORTHEAST ARND 10 KT LATE THIS AFTN AND BACK TO NW
BY 03Z. WINDS CONTINUE TO BACK TO WEST BY EARLY MONDAY MORNING.
GUSTY WINDS FOLLOW THE BAND OF RAIN SHOWERS...WITH 20G30KT
EXPECTED BY MONDAY AFTERNOON. THINKING THE GUSTY WINDS AND DRIER
AIR WILL HELP CIGS LIFT LATE MONDAY MORNING AND AFTN...BUT HAVE
MEDIUM CONFIDENCE IN HOW QUICKLY CIGS LIFT TO VFR.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN RAIN SHOWERS THIS AFTERNOON AND EVENING.
* HIGH CONFIDENCE IN PERIODS OF MVFR VSBY...LOW CONFIDENCE IN
OCCURRENCE AND PERSISTENCE OF IFR VSBY.
* HIGH CONFIDENCE IN IFR CIGS...MEDIUM CONFIDENCE TIMING AND
PERSISTENCE.
* HIGH CONFIDENCE IN WIND TRENDS OVERNIGHT...MEDIUM CONFIDENCE IN
TIMING OF BACKING WINDS.
* HIGH CONFIDENCE IN ALL OTHER FORECAST PARAMETERS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...MVFR BECOMING VFR.
TUESDAY...SLGT CHANCE PM SHRA...BUT MAINLY VFR. GUSTY WEST WINDS.
WEDNESDAY...SLGT CHANCE SHRA. MAINLY VFR. WEST-NORTHWEST WINDS.
THURSDAY...VFR. NORTH-NORTHEAST WINDS.
FRIDAY...MAINLY VFR. CHC PM SHRA.
SATURDAY...MAINLY VFR.
BEACHLER
&&
.MARINE...
324 PM CDT
AS A TROUGH OF LOW PRESSURE AND SECONDARY LOW PRESSURE CENTER
MOVE ACROSS THE GREAT LAKES REGION TONIGHT...WINDS WILL LIKELY BE
VARIABLE AT TIMES. THIS WILL ESPECIALLY BE THE CASE OVER THE
SOUTHERN HALF OF THE LAKE WHERE THE LOW PRESSURE SYSTEM IS
EXPECTED TO MOVE THROUGH. IN THE NEAR TERM...EAST NORTHEAST WINDS
WILL PREVAIL OVER THE LAKE WITH THE HIGHEST SPEEDS TO 30 KT
OCCURRING OVER THE NORTHERN HALF AND WHILE 15 TO 25 KT WINDS ARE
BEING OBSERVED OVER THE SOUTH...WITH SPEEDS EXPECTED TO SLIGHTLY
DIMINISH TONIGHT. AS THIS TROUGH/LOW EXIT TO THE EAST ON
MONDAY...STRONGER WESTERLY WINDS WILL DEVELOP. HIGHEST WINDS TO 30
KT WILL OCCUR ALONG THE NEARSHORE WATERS WHILE ONLY 15 TO 25 KT
ARE LIKELY OVER THE OPEN WATERS. A SIMILAR SETUP IS EXPECTED ON
TUESDAY BUT WITH SPEEDS SLIGHTLY HIGHER...AS TO 30 KT WILL LIKELY
PREVAIL FOR BOTH LOCATIONS AND WITH EVEN GALES POSSIBLE ALONG THE
NEARSHORE WATERS DURING THE DAY.
RODRIGUEZ
&&
.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:
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WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
320 PM CDT SUN APR 19 2015
.SHORT TERM...
319 PM CDT
THROUGH MONDAY NIGHT...
AFTER ANOTHER WARM EARLY AFTERNOON ACROSS MUCH OF THE REGION RAIN IS
BEGINNING TO SPREAD NORTHWARD ACROSS SOUTHERN SECTIONS OF THE CHICAGO
METRO AREA AS OF THIS WRITING. THIS ACTIVITY WILL CONTINUE TO
OVERSPREAD THE REGION THROUGH THE AFTERNOON AND EVENING...WITH
TEMPERATURES LIKELY TO DROP BACK INTO THE UPPER 50S AND LOW 60S IN
THE RAIN.
THE MID-LEVEL DISTURBANCE...AND THE ASSOCIATED SURFACE SYSTEM WILL
QUICKLY SHIFT NORTHWARD OVER LOWER MICHIGAN OVERNIGHT...AND IT
APPEARS THAT THE RAIN WILL BECOME MORE SHOWERY AND INTERMITTENT OR
POSSIBLY JUST SOME DRIZZLE LATER THIS EVENING AND INTO THE EARLY
MORNING ACROSS MUCH OF THE AREA AS THIS INITIAL MID LEVEL
DISTURBANCE SHIFTS NORTH OF THE AREA AND SOME DRIER MID LEVEL AIR
SHIFTS OVER THE SOUTHEASTERN HALF OF MY AREA. SOME ADDITIONAL RAIN
SHOWERS ARE POSSIBLE AGAIN EARLY MONDAY WITHIN A REGION OF MID LEVEL
DEFORMATION AND RAP AROUND MOISTURE ASSOCIATED WITH THE DEEPENING
LOWER AND MID LEVEL LOW OVER THE UPPER GREAT LAKES REGION AND
SOUTHERN CANADA.
CONDITIONS SHOULD DRY OUT MONDAY AFTERNOON...WITH ONLY A SMALL
CHANCE OF AN ADDITIONAL SHOWER DEVELOPING AS COLDER AIR ALOFT
STEEPENS THE LOWER LEVEL LAPSE RATES. THE MAIN STORY DURING THE
AFTERNOON WILL BE THE WINDS. WINDS ARE EXPECTED TO INCREASE OUT OF
THE WEST-NORTHWEST DURING THE DAY AS STOUT SURFACE PRESSURE
GRADIENT SETS UP OVER THE REGION AS THE SURFACE LOW DEEPENS TO
AROUND 985 MB ACROSS ONTARIO MONDAY AFTERNOON. MODEL SOUNDINGS
SUGGEST GOOD AFTERNOON MIXING TO AROUND 850 MB SHOULD ALLOW FOR
GUSTS OF AROUND 30 KT AT TIMES...ESPECIALLY DURING THE AFTERNOON.
THESE WIND GUSTS SHOULD ABATE MONDAY EVENING...BUT STRONG WINDS
LOOK TO DEVELOP AGAIN ON TUESDAY. SEE LONG TERM DISCUSSION FOR
MORE INFO ON TUESDAY`S WINDS.
KJB
&&
.LONG TERM...
319 PM CDT
TUESDAY THROUGH SUNDAY...
MAIN FORECAST CONCERNS/CHALLENGES ARE WITH BELOW NORMAL TEMPS
THROUGH THE FORECAST.
LARGE UPPER LEVEL CENTER WILL BE CENTERED ACROSS THE REGION AT THE
START OF THE PERIOD...AND REMAIN SITUATED THROUGH MUCH OF THE WORK
WEEK AS IT SLOWLY MOVES EAST. SEVERAL VORT LOBES ARE ANTICIPATED TO
WRAP AROUND THIS UPPER LEVEL LOW ON TUESDAY AND WITH STEEPENING
LAPSE RATES...EXPECT SKY COVER TO INCREASE THROUGH THE DAY WHILE
SCATTERED SHOWERS BECOME POSSIBLE...ESPECIALLY ACROSS NORTHERN
ILLINOIS. AS THIS OCCURS...LIKELY DEEP MIXING WITH STRONG FLOW ALOFT
WILL ALLOW FOR ANOTHER WINDY DAY. GUIDANCE IS SUGGESTING THAT
ADVISORY CONDITIONS COULD BE REACHED IN THE AFTERNOON...AND WILL
NEED TO CONTINUE MONITORING THIS POTENTIAL. ANY REMAINING PRECIP AND
CLOUD COVER SHOULD EXIT THE AREA TUESDAY NIGHT WITH DRY CONDITIONS
EXPECTED. SOME GUIDANCE DEVELOPS A SWATH OF PRECIP OVER THE CWA LATE
IN THE NIGHT INTO EARLY WEDNESDAY. HOWEVER...A MORE LIKELY SCENARIO
AT THIS TIME WOULD BE FOR DRY CONDITIONS AND SO HAVE LEFT OUT ANY
POPS AT THIS TIME. ONGOING CAA WILL MAKE FOR CHILLY CONDITIONS
TUESDAY NIGHT...WITH LOW TEMPS IN THE 30S. IF PRECIP WERE TO OCCUR
DURING THIS PERIOD...THESE COLDER CONDITIONS COULD SUPPORT THE
POTENTIAL FOR AT LEAST A RAIN SNOW MIX ACROSS NORTHERN ILLINOIS.
EXPECT DRY CONDITIONS WITH BELOW NORMAL TEMPS THROUGH THE REST OF
THE FORECAST PERIOD...WITH FORECAST HIGHS IN THE 50S. COLD NIGHT
TIME LOWS IN THE 30S COULD BECOME AN ISSUE LATE IN THE WORK WEEK AS
HIGH PRESSURE IS ANTICIPATED TO MOVE OVERHEAD...WITH LIGHTER WINDS
AND THE COLD TEMPS POSSIBLY CREATING A SETUP FOR FROST.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* EAST WINDS ARND 10 KT BCMG NORTH LESS THAN 10 KT THIS EVENING.
* RAIN MOVING IN OVER THE NEXT 1-2 HOURS WITH MVFR VSBY. COULD
HAVE PERIODS OF IFR VSBY WITH HEAVIEST SHOWERS.
* CIGS LOWER TO IFR LATE THIS AFTN THROUGH EARLY MONDAY MORNING.
* SCATTERED SHOWERS OVERNIGHT WITH ANOTHER ROUND OF -SHRA EARLY
MONDAY MORNING.
* GUSTY WEST WINDS WITH MAX GUSTS ARND 30 KT MONDAY AFTN.
JEE
//DISCUSSION...UPDATED 18Z...
RAIN IS SLOWLY PUSHING NORTH AND IS JUST SOUTH OF I-80 AT THIS
TIME. MVFR AND LOWER CIGS ARE OVER CENTRAL AND SOUTHERN IL AND
INDIANA BUT ALSO PUSHING NORTH. ADJUSTED PRECIP AND CIG TIMING
BASED ON RADAR AND SATELLITE TRENDS. MVFR VSBY WILL BE TIED TO THE
HEAVIER RAIN SHOWERS...AND CIGS WILL LOWER TO MVFR LATE THIS AFTN
AND THEN TO IFR THIS EVENING. ALL GUIDANCE MEMBERS SHOW IFR CIGS
ACROSS THE TERMINALS.
WILL EITHER SEE SCATTERED SHOWERS OR A BREAK IN RAIN AFTER
MIDNIGHT TONIGHT WITH ANOTHER ROUND OF RAIN PUSHING WEST TO EAST
EARLY MONDAY MORNING.
EAST WINDS BCM NORTHEAST ARND 10 KT LATE THIS AFTN AND BACK TO NW
BY 03Z. WINDS CONTINUE TO BACK TO WEST BY EARLY MONDAY MORNING.
GUSTY WINDS FOLLOW THE BAND OF RAIN SHOWERS...WITH 20G30KT
EXPECTED BY MONDAY AFTERNOON. THINKING THE GUSTY WINDS AND DRIER
AIR WILL HELP CIGS LIFT LATE MONDAY MORNING AND AFTN...BUT HAVE
MEDIUM CONFIDENCE IN HOW QUICKLY CIGS LIFT TO VFR.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN RAIN SHOWERS THIS AFTERNOON AND EVENING.
* HIGH CONFIDENCE IN PERIODS OF MVFR VSBY...LOW CONFIDENCE IN
OCCURRENCE AND PERSISTENCE OF IFR VSBY.
* HIGH CONFIDENCE IN IFR CIGS...MEDIUM CONFIDENCE TIMING AND
PERSISTENCE.
* HIGH CONFIDENCE IN WIND TRENDS OVERNIGHT...MEDIUM CONFIDENCE IN
TIMING OF BACKING WINDS.
* HIGH CONFIDENCE IN ALL OTHER FORECAST PARAMETERS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...MVFR BECOMING VFR.
TUESDAY...SLGT CHANCE PM SHRA...BUT MAINLY VFR. GUSTY WEST WINDS.
WEDNESDAY...SLGT CHANCE SHRA. MAINLY VFR. WEST-NORTHWEST WINDS.
THURSDAY...VFR. NORTH-NORTHEAST WINDS.
FRIDAY...MAINLY VFR. CHC PM SHRA.
SATURDAY...MAINLY VFR.
BEACHLER
&&
.MARINE...
257 AM CDT
LOW PRESSURE OVER THE CENTRAL PLAINS WILL SLOWLY LIFT NORTHEAST
TOWARDS THE LOWER GREAT LAKES REGION TONIGHT/EARLY MON. GUIDANCE
CONTINUES TO INDICATE THE GRADIENT WILL TIGHTEN ACROSS THE
LAKE...HOWEVER THIS APPEARS TO BE MORE FOCUSED ALONG THE SOUTHERN
TIP OF THE LAKE. WITH THE CONTINUED EASTERLY WINDS...IT IS
POSSIBLE MARGINAL SMALL CRAFT CONDITIONS MAY DEVELOP FOR THE
ILLINOIS SHORELINE LATER TODAY INTO TONIGHT. THE LOW PRESSURE WILL
THEN APPROACH THE LAKE AND BRIEFLY WEAKEN THE GRADIENT EARLY MON.
THEN AS THE LOW LIFTS NORTHEAST LATER IN THE DAY MON...IT WILL
DEEPEN AND MERGE WITH ANOTHER LOW...WHICH WILL CREATE A TIGHT
GRADIENT OVER THE LAKE AND INCREASING WEST/NORTHWEST TUE. AFTER
TUE THE DOMINANT WIND DIRECTION WILL BE NORTHWEST THROUGH MID-
WEEK...BEFORE RELAXING TO THE WEST. THIS WILL ALLOW HIGHER WAVES
TO BE FOCUSED IN THE SOUTHERN HALF OF LAKE MICHIGAN THROUGH MID-
WEEK.
BEACHLER
&&
.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:
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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
248 PM CDT SUN APR 19 2015
.UPDATE...
952 AM CDT
I MADE SOME UPDATES TO THE FORECAST FOR TODAY TO RAISE
TEMPERATURES AND PUSH OFF THE TIMING OF THE RAIN CHANCES.
WATER VAPOR IMAGERY INDICATES OUR MID/UPPER LEVEL DISTURBANCE OF
INTEREST FOR LATER TODAY NOW LIFTING NORTHWARD ACROSS WESTERN
KENTUCKY. THIS FEATURE IS CURRENTLY SUPPORTING AN AREA OF
NORTHWARD MOVING SHOWERS ACROSS SOUTHERN PORTIONS OF ILLINOIS AND
INDIANA. THEREFORE...THIS AREA OF SHOWERS WILL GRADUALLY WORK
NORTHWARD ACROSS NORTHEASTERN ILLINOIS AND NORTHWESTERN INDIANA
DURING THE AFTERNOON. IT APPEARS THE THREAT FOR THUNDERSTORMS WILL
BE VERY LOW WITH THIS ACTIVITY...WITH TRENDS SUGGESTING NO
LIGHTNING STRIKES OVER THE PAST FEW HOURS...SO I HAVE REMOVED THE
MENTION OF SUCH THIS AFTERNOON. IN ADDITION...WITH THE SLOWER
ONSET OF PRECIP TODAY...IT APPEARS TEMPERATURES WILL BE ABLE TO
WARM TO NEAR 70 IN MOST AREAS AWAY FROM LAKE MICHIGAN...SO I
RAISED HIGH TEMPERATURES TODAY.
KJB
&&
.SHORT TERM...
340 AM CDT
THROUGH MONDAY...
UPPER AIR ANALYSIS EARLY THIS MORNING DEPICTS DEEP UPPER LEVEL LOW
PRESSURE NOW PUSHING INTO WESTERN KANSAS. MULTIPLE VORT MAXES ARE
ROTATING AROUND THE LOW. THE STRONGEST OF THESE EXIST IN TEXAS AND
THROUGH THE CENTRAL PLAINS...WITH SOME SMALLER SCALE WAVES EXTENDING
INTO EASTERN MO/FAR WESTERN IL WERE SOME SCATTERED THUNDERSTORMS
WERE ONGOING. A NORTHERN STREAM SHORTWAVE IS ENTERING THE NORTHERN
PLAINS WITH SOME SHOWERS OUT AHEAD OF IT AS WELL. AT THE
SURFACE...THE COLD FRONT THAT PASSED THROUGH NORTHEAST ILLINOIS AND
NW INDIANA SATURDAY HAS PUSHED INTO CENTRAL ILLINOIS...BUT HAS
LIKELY COMPLETED ITS SOUTHWARD RETREAT AND HAS WASHED OUT OVER THE
PAST FEW HOURS. OVER THE LOCAL AREA...MUCH DRIER NE FLOW EXISTS WITH
DEWPOINTS IN THE MID TO UPPER 20S IN THE CITY TO NEAR 40
SOUTH...THOUGH DEWPOINTS ARE POOLING ALONG THE FRONT IN THE UPPER
40S JUST SOUTH OF THE LOT CWA. THE SURFACE LOW THAT IS EXPECTED TO
DEVELOP FROM THE SOUTHERN STREAM SHORTWAVE IS ALSO TAKING SHAPE OVER
THE SOUTHERN STATES WITH A WARM FRONTAL BOUNDARY EXTENDING FROM
WESTERN ARKANSAS THROUGH THE LOWER TENNESSEE VALLEY. AN EXPANSION OF
LOWER CLOUD TOPS ON IR IMAGERY ALONG AND AHEAD OF THE WARM FRONT IS
OCCURRING.
LOW LEVEL WARM/MOIST ADVECTION WILL CONTINUE ITS SLOW PROGRESSION
NORTHWARD UNDER MODEST SOUTH/SOUTHEAST FLOW. DEEPER MOISTURE/LIFT
REALLY HOLD OFF UNTIL THE AFTERNOON PERIOD ACROSS MOST OF THE AREA.
A SOMEWHAT COMPLICATED EVOLUTION AS A MAIN SURFACE LOW CENTER IS
FORECAST TO STRENGTHEN AS IT LIFTS NORTH THROUGH INDIANA TODAY THEN
FURTHER STRENGTHEN TONIGHT INTO MONDAY WHILE SEVERAL ADDITIONAL
SURFACE LOWS DEVELOP AND EVENTUALLY MERGE WITH THE MAIN LOW CENTER.
THE SURFACE LOW WILL EVENTUALLY BECOME DRIVEN BY A COMBINATION OF
THE SW FLOW AHEAD OF THE SOUTHERN STREAM UPPER LOW AND THE
NORTHERN STREAM SHORTWAVE.
OF NOTE LATER TODAY...EXPECT COVERAGE OF SHOWERS TO INITIALLY BE
SLOW GIVEN THE DRIER AIR PLACE...BUT INCREASING ASCENT ALOFT...LOW
LEVEL SSE ISENTROPIC ASCENT AHEAD OF THE LOW AND WRAPPING AROUND THE
CLOSED CIRCULATION EXTENDING THROUGH 850 AND EVEN 700 MB COMBINED
WITH MODEST LOWER LEVEL FGEN SHOULD ALLOW FOR A BLOSSOMING OF
SHOWERS ACROSS THE AREA LATER THIS AFTERNOON AND EVENING. THE
HIGHEST PWAT AXIS EXPANDS ACROSS INDIANA TODAY BUT SHOULD GET
WRAPPED INTO NE ILLINOIS. RAP MOST UNSTABLE CAPE VALUES RELATIVELY
LOW BUT DO EXPAND FROM SE TO NW THIS AFTERNOON AND THIS COUPLED WITH
THE PUNCH FROM THE DRY SLOT OF THIS SYSTEM MAY ENABLE A FEW T-STORMS
AS WELL...SO SOME OF THE SHOWERS WILL HAVE A MODEST KICK TO THEM IN
THE MODERATE/HEAVY RAINFALL DEPARTMENT. EXPECT THAT NORTH CENTRAL
ILLINOIS MAY BE UNDER A BIT OF SQUEEZE PLAY FROM THESE TWO
SYSTEMS...THUS WHILE SHOWERS ARE STILL EXPECTED...HIGHER CONFIDENCE
EXISTS IN COVERAGE FARTHER EAST.
THIS EVENING THE FIRST MAIN SHORTWAVE WILL BE PASSING NE WHILE THE
MAIN SOUTHERN STREAM ENERGY PASSES EAST THROUGH THE OHIO
VALLEY...AND THE NORTHERN STREAM SHORTWAVE LAGS BEHIND BACK IN
MN/IA. THERE IS ALSO THE LOSS OF DEEPER MOISTURE...THEREFORE EXPECT
SHOWERS TO TAPER/END/TURN TO DRIZZLE POSSIBLY OVERNIGHT FOR A TIME.
THEN MONDAY MORNING WE GET THE COUPLED UPPER LEVEL FORCING FROM THE
NORTHERN STREAM LOW AND SURFACE COLD FRONT WHICH WILL LIKELY BRING
ANOTHER ROUND OF SHOWERS MONDAY MORNING. SHOWERS WILL EASE MONDAY
AFTERNOON. IT WILL BE QUITE BREEZY/WINDY BEHIND THE FRONT ON MONDAY
IN THE COLD ADVECTION REGIME.
KMD
&&
.LONG TERM...
340 AM CDT
MONDAY NIGHT THROUGH SATURDAY...
THE THEME OF THE EXTENDED WILL BE THE UNSEASONABLY COOL WEATHER. A
HIGH AMPLITUDE PATTERN WILL BE IN PLACE WITH STRONG UPPER LEVEL
RIDGING EXTENDING WELL NORTH INTO THE CANADIAN ROCKIES AND SIMILARLY
HIGH AMPLITUDE RIDGING IN THE NORTH ATLANTIC. THAT LEAVES OUR
NORTHERN STREAM SHORTWAVE FROM SUNDAY/MONDAY WITH NO WHERE TO GO.
THIS WILL KEEP MUCH OF THE EASTERN HALF OF THE COUNTY...INCLUDING
OUR REGION...UNDER COOL NORTHWEST FLOW. THIS PATTERN ALSO FAVORED
STRONGLY SHEARED OUT AND ELONGATED VORT MAXES TO PIVOT THROUGH
BRINGING PERIODS OF SHOWERS. WITH PWAT VALUES QUITE LOW IN THIS
AIRMASS...MUCH OF THE PERIOD WILL BE DRY AND EVEN THE SHOWERS SHOULD
NOT BE VERY STRONG. BUT MORE IMPORTANTLY...SEASONAL AVERAGE
HIGHS/LOWS FOR LATE APRIL ARE THE LOWER 60S (MID 60S SOUTH) AND
LOWER 40S RESPECTIVELY...AND MUCH OF THIS PERIOD WILL FEATURE HIGHS
IN THE 50S AND LOWS IN THE MID 30S...POSSIBLY COOLER A NIGHT OR TWO
IF WINDS ARE LIGHTER. TEMPERATURE ANOMALIES ARE NOT THAT EXTREME
THOUGH...SO RECORD COLD IS NOT ANTICIPATED.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* EAST WINDS ARND 10 KT BCMG NORTH LESS THAN 10 KT THIS EVENING.
* RAIN MOVING IN OVER THE NEXT 1-2 HOURS WITH MVFR VSBY. COULD
HAVE PERIODS OF IFR VSBY WITH HEAVIEST SHOWERS.
* CIGS LOWER TO IFR LATE THIS AFTN THROUGH EARLY MONDAY MORNING.
* SCATTERED SHOWERS OVERNIGHT WITH ANOTHER ROUND OF -SHRA EARLY
MONDAY MORNING.
* GUSTY WEST WINDS WITH MAX GUSTS ARND 30 KT MONDAY AFTN.
JEE
//DISCUSSION...UPDATED 18Z...
RAIN IS SLOWLY PUSHING NORTH AND IS JUST SOUTH OF I-80 AT THIS
TIME. MVFR AND LOWER CIGS ARE OVER CENTRAL AND SOUTHERN IL AND
INDIANA BUT ALSO PUSHING NORTH. ADJUSTED PRECIP AND CIG TIMING
BASED ON RADAR AND SATELLITE TRENDS. MVFR VSBY WILL BE TIED TO THE
HEAVIER RAIN SHOWERS...AND CIGS WILL LOWER TO MVFR LATE THIS AFTN
AND THEN TO IFR THIS EVENING. ALL GUIDANCE MEMBERS SHOW IFR CIGS
ACROSS THE TERMINALS.
WILL EITHER SEE SCATTERED SHOWERS OR A BREAK IN RAIN AFTER
MIDNIGHT TONIGHT WITH ANOTHER ROUND OF RAIN PUSHING WEST TO EAST
EARLY MONDAY MORNING.
EAST WINDS BCM NORTHEAST ARND 10 KT LATE THIS AFTN AND BACK TO NW
BY 03Z. WINDS CONTINUE TO BACK TO WEST BY EARLY MONDAY MORNING.
GUSTY WINDS FOLLOW THE BAND OF RAIN SHOWERS...WITH 20G30KT
EXPECTED BY MONDAY AFTERNOON. THINKING THE GUSTY WINDS AND DRIER
AIR WILL HELP CIGS LIFT LATE MONDAY MORNING AND AFTN...BUT HAVE
MEDIUM CONFIDENCE IN HOW QUICKLY CIGS LIFT TO VFR.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN RAIN SHOWERS THIS AFTERNOON AND EVENING.
* HIGH CONFIDENCE IN PERIODS OF MVFR VSBY...LOW CONFIDENCE IN
OCCURRENCE AND PERSISTENCE OF IFR VSBY.
* HIGH CONFIDENCE IN IFR CIGS...MEDIUM CONFIDENCE TIMING AND
PERSISTENCE.
* HIGH CONFIDENCE IN WIND TRENDS OVERNIGHT...MEDIUM CONFIDENCE IN
TIMING OF BACKING WINDS.
* HIGH CONFIDENCE IN ALL OTHER FORECAST PARAMETERS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...MVFR BECOMING VFR.
TUESDAY...SLGT CHANCE PM SHRA...BUT MAINLY VFR. GUSTY WEST WINDS.
WEDNESDAY...SLGT CHANCE SHRA. MAINLY VFR. WEST-NORTHWEST WINDS.
THURSDAY...VFR. NORTH-NORTHEAST WINDS.
FRIDAY...MAINLY VFR. CHC PM SHRA.
SATURDAY...MAINLY VFR.
BEACHLER
&&
.MARINE...
257 AM CDT
LOW PRESSURE OVER THE CENTRAL PLAINS WILL SLOWLY LIFT NORTHEAST
TOWARDS THE LOWER GREAT LAKES REGION TONIGHT/EARLY MON. GUIDANCE
CONTINUES TO INDICATE THE GRADIENT WILL TIGHTEN ACROSS THE
LAKE...HOWEVER THIS APPEARS TO BE MORE FOCUSED ALONG THE SOUTHERN
TIP OF THE LAKE. WITH THE CONTINUED EASTERLY WINDS...IT IS
POSSIBLE MARGINAL SMALL CRAFT CONDITIONS MAY DEVELOP FOR THE
ILLINOIS SHORELINE LATER TODAY INTO TONIGHT. THE LOW PRESSURE WILL
THEN APPROACH THE LAKE AND BRIEFLY WEAKEN THE GRADIENT EARLY MON.
THEN AS THE LOW LIFTS NORTHEAST LATER IN THE DAY MON...IT WILL
DEEPEN AND MERGE WITH ANOTHER LOW...WHICH WILL CREATE A TIGHT
GRADIENT OVER THE LAKE AND INCREASING WEST/NORTHWEST TUE. AFTER
TUE THE DOMINANT WIND DIRECTION WILL BE NORTHWEST THROUGH MID-
WEEK...BEFORE RELAXING TO THE WEST. THIS WILL ALLOW HIGHER WAVES
TO BE FOCUSED IN THE SOUTHERN HALF OF LAKE MICHIGAN THROUGH MID-
WEEK.
BEACHLER
&&
.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
1237 PM CDT SUN APR 19 2015
.UPDATE...
952 AM CDT
I MADE SOME UPDATES TO THE FORECAST FOR TODAY TO RAISE
TEMPERATURES AND PUSH OFF THE TIMING OF THE RAIN CHANCES.
WATER VAPOR IMAGERY INDICATES OUR MID/UPPER LEVEL DISTURBANCE OF
INTEREST FOR LATER TODAY NOW LIFTING NORTHWARD ACROSS WESTERN
KENTUCKY. THIS FEATURE IS CURRENTLY SUPPORTING AN AREA OF
NORTHWARD MOVING SHOWERS ACROSS SOUTHERN PORTIONS OF ILLINOIS AND
INDIANA. THEREFORE...THIS AREA OF SHOWERS WILL GRADUALLY WORK
NORTHWARD ACROSS NORTHEASTERN ILLINOIS AND NORTHWESTERN INDIANA
DURING THE AFTERNOON. IT APPEARS THE THREAT FOR THUNDERSTORMS WILL
BE VERY LOW WITH THIS ACTIVITY...WITH TRENDS SUGGESTING NO
LIGHTNING STRIKES OVER THE PAST FEW HOURS...SO I HAVE REMOVED THE
MENTION OF SUCH THIS AFTERNOON. IN ADDITION...WITH THE SLOWER
ONSET OF PRECIP TODAY...IT APPEARS TEMPERATURES WILL BE ABLE TO
WARM TO NEAR 70 IN MOST AREAS AWAY FROM LAKE MICHIGAN...SO I
RAISED HIGH TEMPERATURES TODAY.
KJB
&&
.SHORT TERM...
340 AM CDT
THROUGH MONDAY...
UPPER AIR ANALYSIS EARLY THIS MORNING DEPICTS DEEP UPPER LEVEL LOW
PRESSURE NOW PUSHING INTO WESTERN KANSAS. MULTIPLE VORT MAXES ARE
ROTATING AROUND THE LOW. THE STRONGEST OF THESE EXIST IN TEXAS AND
THROUGH THE CENTRAL PLAINS...WITH SOME SMALLER SCALE WAVES EXTENDING
INTO EASTERN MO/FAR WESTERN IL WERE SOME SCATTERED THUNDERSTORMS
WERE ONGOING. A NORTHERN STREAM SHORTWAVE IS ENTERING THE NORTHERN
PLAINS WITH SOME SHOWERS OUT AHEAD OF IT AS WELL. AT THE
SURFACE...THE COLD FRONT THAT PASSED THROUGH NORTHEAST ILLINOIS AND
NW INDIANA SATURDAY HAS PUSHED INTO CENTRAL ILLINOIS...BUT HAS
LIKELY COMPLETED ITS SOUTHWARD RETREAT AND HAS WASHED OUT OVER THE
PAST FEW HOURS. OVER THE LOCAL AREA...MUCH DRIER NE FLOW EXISTS WITH
DEWPOINTS IN THE MID TO UPPER 20S IN THE CITY TO NEAR 40
SOUTH...THOUGH DEWPOINTS ARE POOLING ALONG THE FRONT IN THE UPPER
40S JUST SOUTH OF THE LOT CWA. THE SURFACE LOW THAT IS EXPECTED TO
DEVELOP FROM THE SOUTHERN STREAM SHORTWAVE IS ALSO TAKING SHAPE OVER
THE SOUTHERN STATES WITH A WARM FRONTAL BOUNDARY EXTENDING FROM
WESTERN ARKANSAS THROUGH THE LOWER TENNESSEE VALLEY. AN EXPANSION OF
LOWER CLOUD TOPS ON IR IMAGERY ALONG AND AHEAD OF THE WARM FRONT IS
OCCURRING.
LOW LEVEL WARM/MOIST ADVECTION WILL CONTINUE ITS SLOW PROGRESSION
NORTHWARD UNDER MODEST SOUTH/SOUTHEAST FLOW. DEEPER MOISTURE/LIFT
REALLY HOLD OFF UNTIL THE AFTERNOON PERIOD ACROSS MOST OF THE AREA.
A SOMEWHAT COMPLICATED EVOLUTION AS A MAIN SURFACE LOW CENTER IS
FORECAST TO STRENGTHEN AS IT LIFTS NORTH THROUGH INDIANA TODAY THEN
FURTHER STRENGTHEN TONIGHT INTO MONDAY WHILE SEVERAL ADDITIONAL
SURFACE LOWS DEVELOP AND EVENTUALLY MERGE WITH THE MAIN LOW CENTER.
THE SURFACE LOW WILL EVENTUALLY BECOME DRIVEN BY A COMBINATION OF
THE SW FLOW AHEAD OF THE SOUTHERN STREAM UPPER LOW AND THE
NORTHERN STREAM SHORTWAVE.
OF NOTE LATER TODAY...EXPECT COVERAGE OF SHOWERS TO INITIALLY BE
SLOW GIVEN THE DRIER AIR PLACE...BUT INCREASING ASCENT ALOFT...LOW
LEVEL SSE ISENTROPIC ASCENT AHEAD OF THE LOW AND WRAPPING AROUND THE
CLOSED CIRCULATION EXTENDING THROUGH 850 AND EVEN 700 MB COMBINED
WITH MODEST LOWER LEVEL FGEN SHOULD ALLOW FOR A BLOSSOMING OF
SHOWERS ACROSS THE AREA LATER THIS AFTERNOON AND EVENING. THE
HIGHEST PWAT AXIS EXPANDS ACROSS INDIANA TODAY BUT SHOULD GET
WRAPPED INTO NE ILLINOIS. RAP MOST UNSTABLE CAPE VALUES RELATIVELY
LOW BUT DO EXPAND FROM SE TO NW THIS AFTERNOON AND THIS COUPLED WITH
THE PUNCH FROM THE DRY SLOT OF THIS SYSTEM MAY ENABLE A FEW T-STORMS
AS WELL...SO SOME OF THE SHOWERS WILL HAVE A MODEST KICK TO THEM IN
THE MODERATE/HEAVY RAINFALL DEPARTMENT. EXPECT THAT NORTH CENTRAL
ILLINOIS MAY BE UNDER A BIT OF SQUEEZE PLAY FROM THESE TWO
SYSTEMS...THUS WHILE SHOWERS ARE STILL EXPECTED...HIGHER CONFIDENCE
EXISTS IN COVERAGE FARTHER EAST.
THIS EVENING THE FIRST MAIN SHORTWAVE WILL BE PASSING NE WHILE THE
MAIN SOUTHERN STREAM ENERGY PASSES EAST THROUGH THE OHIO
VALLEY...AND THE NORTHERN STREAM SHORTWAVE LAGS BEHIND BACK IN
MN/IA. THERE IS ALSO THE LOSS OF DEEPER MOISTURE...THEREFORE EXPECT
SHOWERS TO TAPER/END/TURN TO DRIZZLE POSSIBLY OVERNIGHT FOR A TIME.
THEN MONDAY MORNING WE GET THE COUPLED UPPER LEVEL FORCING FROM THE
NORTHERN STREAM LOW AND SURFACE COLD FRONT WHICH WILL LIKELY BRING
ANOTHER ROUND OF SHOWERS MONDAY MORNING. SHOWERS WILL EASE MONDAY
AFTERNOON. IT WILL BE QUITE BREEZY/WINDY BEHIND THE FRONT ON MONDAY
IN THE COLD ADVECTION REGIME.
KMD
&&
.LONG TERM...
340 AM CDT
MONDAY NIGHT THROUGH SATURDAY...
THE THEME OF THE EXTENDED WILL BE THE UNSEASONABLY COOL WEATHER. A
HIGH AMPLITUDE PATTERN WILL BE IN PLACE WITH STRONG UPPER LEVEL
RIDGING EXTENDING WELL NORTH INTO THE CANADIAN ROCKIES AND SIMILARLY
HIGH AMPLITUDE RIDGING IN THE NORTH ATLANTIC. THAT LEAVES OUR
NORTHERN STREAM SHORTWAVE FROM SUNDAY/MONDAY WITH NO WHERE TO GO.
THIS WILL KEEP MUCH OF THE EASTERN HALF OF THE COUNTY...INCLUDING
OUR REGION...UNDER COOL NORTHWEST FLOW. THIS PATTERN ALSO FAVORED
STRONGLY SHEARED OUT AND ELONGATED VORT MAXES TO PIVOT THROUGH
BRINGING PERIODS OF SHOWERS. WITH PWAT VALUES QUITE LOW IN THIS
AIRMASS...MUCH OF THE PERIOD WILL BE DRY AND EVEN THE SHOWERS SHOULD
NOT BE VERY STRONG. BUT MORE IMPORTANTLY...SEASONAL AVERAGE
HIGHS/LOWS FOR LATE APRIL ARE THE LOWER 60S (MID 60S SOUTH) AND
LOWER 40S RESPECTIVELY...AND MUCH OF THIS PERIOD WILL FEATURE HIGHS
IN THE 50S AND LOWS IN THE MID 30S...POSSIBLY COOLER A NIGHT OR TWO
IF WINDS ARE LIGHTER. TEMPERATURE ANOMALIES ARE NOT THAT EXTREME
THOUGH...SO RECORD COLD IS NOT ANTICIPATED.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* EAST WINDS 10-14 KT BCMG NORTH LESS THAN 10 KT THIS EVENING.
* RAIN ARRIVES 21-22Z WITH 5SM VSBY WITH HEAVIER SHOWERS.
* CIGS LOWER TO MVFR LATE THIS AFTN THEN TO IFR THIS EVENING
THROUGH EARLY MONDAY MORNING.
* SCATTERED SHOWERS OVERNIGHT WITH ANOTHER ROUND OF -SHRA EARLY
MONDAY MORNING.
* GUSTY WEST WINDS WITH MAX GUSTS ARND 30 KT MONDAY AFTN.
JEE
//DISCUSSION...UPDATED 18Z...
RAIN IS SLOWLY PUSHING NORTH AND IS JUST SOUTH OF I-80 AT THIS
TIME. MVFR AND LOWER CIGS ARE OVER CENTRAL AND SOUTHERN IL AND
INDIANA BUT ALSO PUSHING NORTH. ADJUSTED PRECIP AND CIG TIMING
BASED ON RADAR AND SATELLITE TRENDS. MVFR VSBY WILL BE TIED TO THE
HEAVIER RAIN SHOWERS...AND CIGS WILL LOWER TO MVFR LATE THIS AFTN
AND THEN TO IFR THIS EVENING. ALL GUIDANCE MEMBERS SHOW IFR CIGS
ACROSS THE TERMINALS.
WILL EITHER SEE SCATTERED SHOWERS OR A BREAK IN RAIN AFTER
MIDNIGHT TONIGHT WITH ANOTHER ROUND OF RAIN PUSHING WEST TO EAST
EARLY MONDAY MORNING.
EAST WINDS BCM NORTHEAST ARND 10 KT LATE THIS AFTN AND BACK TO NW
BY 03Z. WINDS CONTINUE TO BACK TO WEST BY EARLY MONDAY MORNING.
GUSTY WINDS FOLLOW THE BAND OF RAIN SHOWERS...WITH 20G30KT
EXPECTED BY MONDAY AFTERNOON. THINKING THE GUSTY WINDS AND DRIER
AIR WILL HELP CIGS LIFT LATE MONDAY MORNING AND AFTN...BUT HAVE
MEDIUM CONFIDENCE IN HOW QUICKLY CIGS LIFT TO VFR.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN RAIN SHOWERS THIS AFTERNOON AND EVENING.
* HIGH CONFIDENCE IN MVFR CIGS...MEDIUM CONFIDENCE IN MVFR CIG
TIMING AND OCCURRENCE AND TIMING OF IFR CIGS.
* HIGH CONFIDENCE IN WIND TRENDS OVERNIGHT...MEDIUM CONFIDENCE IN
TIMING OF BACKING WINDS.
* MEDIUM CONFIDENCE IN HOW QUICKLY CIGS LIFT TO VFR MONDAY.
* HIGH CONFIDENCE IN ALL OTHER FORECAST PARAMETERS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...MVFR BECOMING VFR.
TUESDAY...SLGT CHANCE PM SHRA...BUT MAINLY VFR. GUSTY WEST WINDS.
WEDNESDAY...SLGT CHANCE SHRA. MAINLY VFR. WEST-NORTHWEST WINDS.
THURSDAY...VFR. NORTH-NORTHEAST WINDS.
FRIDAY...MAINLY VFR. CHC PM SHRA.
SATURDAY...MAINLY VFR.
BEACHLER
&&
.MARINE...
257 AM CDT
LOW PRESSURE OVER THE CENTRAL PLAINS WILL SLOWLY LIFT NORTHEAST
TOWARDS THE LOWER GREAT LAKES REGION TONIGHT/EARLY MON. GUIDANCE
CONTINUES TO INDICATE THE GRADIENT WILL TIGHTEN ACROSS THE
LAKE...HOWEVER THIS APPEARS TO BE MORE FOCUSED ALONG THE SOUTHERN
TIP OF THE LAKE. WITH THE CONTINUED EASTERLY WINDS...IT IS
POSSIBLE MARGINAL SMALL CRAFT CONDITIONS MAY DEVELOP FOR THE
ILLINOIS SHORELINE LATER TODAY INTO TONIGHT. THE LOW PRESSURE WILL
THEN APPROACH THE LAKE AND BRIEFLY WEAKEN THE GRADIENT EARLY MON.
THEN AS THE LOW LIFTS NORTHEAST LATER IN THE DAY MON...IT WILL
DEEPEN AND MERGE WITH ANOTHER LOW...WHICH WILL CREATE A TIGHT
GRADIENT OVER THE LAKE AND INCREASING WEST/NORTHWEST TUE. AFTER
TUE THE DOMINANT WIND DIRECTION WILL BE NORTHWEST THROUGH MID-
WEEK...BEFORE RELAXING TO THE WEST. THIS WILL ALLOW HIGHER WAVES
TO BE FOCUSED IN THE SOUTHERN HALF OF LAKE MICHIGAN THROUGH MID-
WEEK.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS LINCOLN IL
1229 PM CDT SUN APR 19 2015
.UPDATE...
ISSUED AT 1114 AM CDT SUN APR 19 2015
SFC LOW LIFTING NORTHWARD INTO THE REGION AND PUSHING PLENTY OF
WAA RAIN AHEAD OF IT ACROSS THE FA. PLENTY OF PRECIP EXPECTED
TODAY AND INTO TONIGHT, BUT MORE SCATTERED IN NATURE IN THE
OVERNIGHT HOURS. SOME DRY AIR WORKING AROUND THE LOW AND ERODING
SOME OF THE RAINFALL MAY BRING A BREAK IN THE RAINFALL
BRIEFLY...BUT NOT ENOUGH TO PULL PRECIP ANYWHERE FOR LONG. HAVE
MADE A FEW ADJUSTMENTS TO THE FORECAST, BUT NO MAJOR UPDATES ARE
ANTICIPATED AT THIS TIME.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 328 AM CDT SUN APR 19 2015
LATEST WATER VAPOR IMAGERY CONTINUES TO SHOW CLOSED UPPER LOW OVER
EASTERN COLORADO, WITH LEAD SHORT-WAVE ROTATING AROUND THIS FEATURE
ACROSS ARKANSAS/LOUISIANA. AS THIS WAVE LIFTS NORTHWARD, PRECIP
WILL EVENTUALLY SPREAD INTO CENTRAL ILLINOIS TODAY. 07Z/2AM RADAR
MOSAIC SHOWS DRY CONDITIONS ACROSS THE ENTIRE KILX CWA: HOWEVER,
SHOWERS ARE BEGINNING TO DEVELOP AND BECOME MORE WIDESPREAD FURTHER
SOUTH ACROSS WESTERN KENTUCKY AND FAR SOUTHERN ILLINOIS. BASED ON
RADAR TIMING TOOLS AND LATEST HRRR FORECAST, THINK SCATTERED SHOWERS
WILL ARRIVE SOUTH OF I-70 OVER THE NEXT COUPLE OF HOURS, THEN WILL
SPREAD NORTHWARD TOWARD THE I-74 CORRIDOR BY MIDDAY. HAVE ADJUSTED
POPS TO ACCOUNT FOR THE SLOWER ARRIVAL OF PRECIP DURING THE MORNING,
THEN HAVE GONE WITH CATEGORICAL POPS ACROSS THE BOARD THIS
AFTERNOON. ASIDE FROM SOME SBCAPES OF AROUND 1000J/KG ACROSS THE
FAR SE CWA, FORECAST SOUNDINGS REMAIN FAIRLY STABLE TODAY. AS A
RESULT, AM EXPECTING MAINLY SHOWERS WITH JUST A FEW EMBEDDED
THUNDERSTORMS. DUE TO CLOUD COVER AND PRECIP, HIGH TEMPERATURES
WILL BE SEVERAL DEGREES COOLER THAN IN RECENT DAYS, WITH READINGS
MAINLY IN THE 60S. WARMEST TEMPS OF AROUND 70 WILL BE FOCUSED
ALONG/WEST OF THE ILLINOIS RIVER WHERE PRECIP WILL BE SLOWEST TO
ARRIVE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 328 AM CDT SUN APR 19 2015
LEAD SHORT-WAVE WILL LIFT INTO NORTHERN ILLINOIS/INDIANA BY EARLY
EVENING, LIKELY LEADING TO A TEMPORARY LULL IN THE SHOWERS.
MEANWHILE, THE MAIN UPPER LOW WILL GET A SOLID PUSH EASTWARD AND
WILL ARRIVE ACROSS ILLINOIS LATER TONIGHT INTO MONDAY MORNING.
SHOWERS AND PERHAPS A THUNDERSTORM WILL ACCOMPANY THIS FEATURE, SO
WILL CONTINUE LIKELY POPS TONIGHT THROUGH MONDAY MORNING. ONCE THE
500MB VORT MAX AND THE ASSOCIATED SURFACE COLD FRONT PASS TO THE
EAST, RAIN CHANCES WILL COME TO AN END BY MONDAY AFTERNOON. THANKS
TO A TIGHT PRESSURE GRADIENT BEHIND THE DEPARTING FRONT, STRONG W/NW
WINDS GUSTING TO BETWEEN 25 AND 30 MPH WILL DEVELOP ON MONDAY. THE
WINDS WILL SUBSIDE FOR A TIME MONDAY NIGHT, BUT WILL ONCE AGAIN
INCREASE MARKEDLY DURING THE DAY TUESDAY. HIGH TEMPERATURES BOTH
DAYS WILL REMAIN IN THE LOWER 60S, WHILE OVERNIGHT LOWS DIP INTO THE
UPPER 30S AND LOWER 40S.
00Z APR 19 MODELS HAVE COME INTO MUCH BETTER AGREEMENT CONCERNING
THE EXTENDED FORECAST, WITH CONSENSUS FEATURING A CHILLY AND LARGELY
DRY WEEK AHEAD. BOTH THE GFS AND ECMWF INDICATE A WEAK COLD FRONT
WILL PASS THROUGH CENTRAL ILLINOIS TUESDAY NIGHT INTO WEDNESDAY:
HOWEVER, THEY DISAGREE ON HOW MUCH PRECIP IT WILL GENERATE. THE GFS
IS SLIGHTLY WETTER AND FASTER WITH FROPA, WHILE THE ECMWF IS DRIER
AND ABOUT 6 HOURS SLOWER WITH THE FRONT. DUE TO THE STRONG
NORTHWESTERLY UPPER FLOW PATTERN IN PLACE ACROSS THE MIDWEST, THINK
THE FASTER GFS IS THE WAY TO GO WITH TIMING, BUT THINK THE DRIER
ECMWF IS BETTER WITH QPF AS DEEP MOISTURE WILL BE LACKING WITH THIS
FEATURE. AS A RESULT, HAVE OPTED TO CARRY LOW CHANCE POPS
EVERYWHERE TUESDAY NIGHT, THEN ONLY ACROSS THE SE CWA ON WEDNESDAY.
ONCE THE FRONT PASSES, A COOL/CANADIAN AIRMASS WILL SETTLE INTO THE
REGION FOR THE MIDDLE AND END OF THE WEEK. HIGH TEMPERATURES WILL
STRUGGLE TO REACH THE 60 DEGREE MARK ON BOTH WEDNESDAY AND THURSDAY,
WHILE LOWS DROP INTO THE 30S. COLDEST MORNING MAY END UP BEING
FRIDAY MORNING, WHEN RIDGE OF HIGH PRESSURE IS OVERHEAD AND WINDS
WILL BE LIGHTEST. WILL NEED TO KEEP AN EYE ON TEMPS, AS FROST
ADVISORIES WILL BE POSSIBLE ACROSS PARTS OF CENTRAL/SOUTHEAST
ILLINOIS LATER THIS WEEK. AFTER THAT, ANOTHER SYSTEM WILL APPROACH
FROM THE SOUTHWEST BY THE END OF THE WEEK: HOWEVER, ITS INFLUENCE
LIKELY WILL NOT BE FELT UNTIL FRIDAY NIGHT/SATURDAY AT THE EARLIEST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1226 PM CDT SUN APR 19 2015
MODELS BRINGING THE SFC LOW UP AND THROUGH THE AREA WITHIN THE TAF
PD. TWO MAJOR CONCERNS...VIS DROP AND LOW CIGS ASSOCIATED WITH THE
PROLONGED RAIN. HAVE KEPT THE LOWER VIS/CIGS ON THE EASTERN
TERMINALS. CONCERN ON THE WEST SIDE IS THE MODEL HINT AT A
SECONDARY LINE OF PRECIP SHOWING UP WITH THE 500MB TROF LATER AS
THE LOW PULLS OUT TO THE EAST. GUIDANCE NOT REALLY REFLECTING THAT
WELL...AND WILL BE IN CONFLICT WITH SOME OF THE DRIER AIR BEING
PULLED INTO THE WEST SIDE OF THE SYSTEM. CONFIDENCE LOWER FOR PIA
AND SPI THAN THE OTHER SITES.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HJS
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...HJS
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1119 AM CDT SUN APR 19 2015
.UPDATE...
ISSUED AT 1114 AM CDT SUN APR 19 2015
SFC LOW LIFTING NORTHWARD INTO THE REGION AND PUSHING PLENTY OF
WAA RAIN AHEAD OF IT ACROSS THE FA. PLENTY OF PRECIP EXPECTED
TODAY AND INTO TONIGHT, BUT MORE SCATTERED IN NATURE IN THE
OVERNIGHT HOURS. SOME DRY AIR WORKING AROUND THE LOW AND ERODING
SOME OF THE RAINFALL MAY BRING A BREAK IN THE RAINFALL
BRIEFLY...BUT NOT ENOUGH TO PULL PRECIP ANYWHERE FOR LONG. HAVE
MADE A FEW ADJUSTMENTS TO THE FORECAST, BUT NO MAJOR UPDATES ARE
ANTICIPATED AT THIS TIME.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 328 AM CDT SUN APR 19 2015
LATEST WATER VAPOR IMAGERY CONTINUES TO SHOW CLOSED UPPER LOW OVER
EASTERN COLORADO, WITH LEAD SHORT-WAVE ROTATING AROUND THIS FEATURE
ACROSS ARKANSAS/LOUISIANA. AS THIS WAVE LIFTS NORTHWARD, PRECIP
WILL EVENTUALLY SPREAD INTO CENTRAL ILLINOIS TODAY. 07Z/2AM RADAR
MOSAIC SHOWS DRY CONDITIONS ACROSS THE ENTIRE KILX CWA: HOWEVER,
SHOWERS ARE BEGINNING TO DEVELOP AND BECOME MORE WIDESPREAD FURTHER
SOUTH ACROSS WESTERN KENTUCKY AND FAR SOUTHERN ILLINOIS. BASED ON
RADAR TIMING TOOLS AND LATEST HRRR FORECAST, THINK SCATTERED SHOWERS
WILL ARRIVE SOUTH OF I-70 OVER THE NEXT COUPLE OF HOURS, THEN WILL
SPREAD NORTHWARD TOWARD THE I-74 CORRIDOR BY MIDDAY. HAVE ADJUSTED
POPS TO ACCOUNT FOR THE SLOWER ARRIVAL OF PRECIP DURING THE MORNING,
THEN HAVE GONE WITH CATEGORICAL POPS ACROSS THE BOARD THIS
AFTERNOON. ASIDE FROM SOME SBCAPES OF AROUND 1000J/KG ACROSS THE
FAR SE CWA, FORECAST SOUNDINGS REMAIN FAIRLY STABLE TODAY. AS A
RESULT, AM EXPECTING MAINLY SHOWERS WITH JUST A FEW EMBEDDED
THUNDERSTORMS. DUE TO CLOUD COVER AND PRECIP, HIGH TEMPERATURES
WILL BE SEVERAL DEGREES COOLER THAN IN RECENT DAYS, WITH READINGS
MAINLY IN THE 60S. WARMEST TEMPS OF AROUND 70 WILL BE FOCUSED
ALONG/WEST OF THE ILLINOIS RIVER WHERE PRECIP WILL BE SLOWEST TO
ARRIVE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 328 AM CDT SUN APR 19 2015
LEAD SHORT-WAVE WILL LIFT INTO NORTHERN ILLINOIS/INDIANA BY EARLY
EVENING, LIKELY LEADING TO A TEMPORARY LULL IN THE SHOWERS.
MEANWHILE, THE MAIN UPPER LOW WILL GET A SOLID PUSH EASTWARD AND
WILL ARRIVE ACROSS ILLINOIS LATER TONIGHT INTO MONDAY MORNING.
SHOWERS AND PERHAPS A THUNDERSTORM WILL ACCOMPANY THIS FEATURE, SO
WILL CONTINUE LIKELY POPS TONIGHT THROUGH MONDAY MORNING. ONCE THE
500MB VORT MAX AND THE ASSOCIATED SURFACE COLD FRONT PASS TO THE
EAST, RAIN CHANCES WILL COME TO AN END BY MONDAY AFTERNOON. THANKS
TO A TIGHT PRESSURE GRADIENT BEHIND THE DEPARTING FRONT, STRONG W/NW
WINDS GUSTING TO BETWEEN 25 AND 30 MPH WILL DEVELOP ON MONDAY. THE
WINDS WILL SUBSIDE FOR A TIME MONDAY NIGHT, BUT WILL ONCE AGAIN
INCREASE MARKEDLY DURING THE DAY TUESDAY. HIGH TEMPERATURES BOTH
DAYS WILL REMAIN IN THE LOWER 60S, WHILE OVERNIGHT LOWS DIP INTO THE
UPPER 30S AND LOWER 40S.
00Z APR 19 MODELS HAVE COME INTO MUCH BETTER AGREEMENT CONCERNING
THE EXTENDED FORECAST, WITH CONSENSUS FEATURING A CHILLY AND LARGELY
DRY WEEK AHEAD. BOTH THE GFS AND ECMWF INDICATE A WEAK COLD FRONT
WILL PASS THROUGH CENTRAL ILLINOIS TUESDAY NIGHT INTO WEDNESDAY:
HOWEVER, THEY DISAGREE ON HOW MUCH PRECIP IT WILL GENERATE. THE GFS
IS SLIGHTLY WETTER AND FASTER WITH FROPA, WHILE THE ECMWF IS DRIER
AND ABOUT 6 HOURS SLOWER WITH THE FRONT. DUE TO THE STRONG
NORTHWESTERLY UPPER FLOW PATTERN IN PLACE ACROSS THE MIDWEST, THINK
THE FASTER GFS IS THE WAY TO GO WITH TIMING, BUT THINK THE DRIER
ECMWF IS BETTER WITH QPF AS DEEP MOISTURE WILL BE LACKING WITH THIS
FEATURE. AS A RESULT, HAVE OPTED TO CARRY LOW CHANCE POPS
EVERYWHERE TUESDAY NIGHT, THEN ONLY ACROSS THE SE CWA ON WEDNESDAY.
ONCE THE FRONT PASSES, A COOL/CANADIAN AIRMASS WILL SETTLE INTO THE
REGION FOR THE MIDDLE AND END OF THE WEEK. HIGH TEMPERATURES WILL
STRUGGLE TO REACH THE 60 DEGREE MARK ON BOTH WEDNESDAY AND THURSDAY,
WHILE LOWS DROP INTO THE 30S. COLDEST MORNING MAY END UP BEING
FRIDAY MORNING, WHEN RIDGE OF HIGH PRESSURE IS OVERHEAD AND WINDS
WILL BE LIGHTEST. WILL NEED TO KEEP AN EYE ON TEMPS, AS FROST
ADVISORIES WILL BE POSSIBLE ACROSS PARTS OF CENTRAL/SOUTHEAST
ILLINOIS LATER THIS WEEK. AFTER THAT, ANOTHER SYSTEM WILL APPROACH
FROM THE SOUTHWEST BY THE END OF THE WEEK: HOWEVER, ITS INFLUENCE
LIKELY WILL NOT BE FELT UNTIL FRIDAY NIGHT/SATURDAY AT THE EARLIEST.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 542 AM CDT SUN APR 19 2015
MID AND HIGH CLOUDS WILL CONTINUE OVER THE AREA THIS MORNING,
EFFECTING ALL TAF SITES UNTIL THE PCPN MOVES INTO THE SITES. WILL
START ALL SITES WITH VCSH AS THE PCPN MOVES NORTHWARD AND
INITIALLY SATURATES THE LOWER LEVELS, DURING THE MORNING HOURS.
THEN BETWEEN 10AM AND NOON, PCPN WILL BECOME MORE DOMINATE AND
STEADY. TIMING OF ONSET OF PCPN WAS TAKEN FROM A BLEND OF THE
BUFKIT DATA, NAM12, HRRR, AND RADAR TRENDS. MVFR CIGS AND VIS
WILL ARRIVE WITH THE RAIN AND CONTINUE THROUGH REST OF TAF VALID
PERIOD. PCPN COULD LET UP SOME LATE THIS EVENING, SO HAVE ADDED
ANOTHER LINE FOR VCSH AFTER THE BULK OF THE RAIN MOVES THROUGH,
AND BEFORE THE NEXT BATCH ARRIVES LATE TONIGHT/EARLY TOMORROW
MORNING. WINDS WILL BE EASTERLY TO START, BUT THEN BECOME
SOUTHEASTERLY AS THE SYSTEM GET CLOSER TO THE SITES. WITH THE
SURFACE LOW PRESSURE AREA MOVING RIGHT OVER THE TAFS, WINDS WILL
BE VARIABLE, ENDING AT WEST TO SOUTHWEST LATER TONIGHT.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HJS
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1110 AM CDT SUN APR 19 2015
.UPDATE...
952 AM CDT
I MADE SOME UPDATES TO THE FORECAST FOR TODAY TO RAISE
TEMPERATURES AND PUSH OFF THE TIMING OF THE RAIN CHANCES.
WATER VAPOR IMAGERY INDICATES OUR MID/UPPER LEVEL DISTURBANCE OF
INTEREST FOR LATER TODAY NOW LIFTING NORTHWARD ACROSS WESTERN
KENTUCKY. THIS FEATURE IS CURRENTLY SUPPORTING AN AREA OF
NORTHWARD MOVING SHOWERS ACROSS SOUTHERN PORTIONS OF ILLINOIS AND
INDIANA. THEREFORE...THIS AREA OF SHOWERS WILL GRADUALLY WORK
NORTHWARD ACROSS NORTHEASTERN ILLINOIS AND NORTHWESTERN INDIANA
DURING THE AFTERNOON. IT APPEARS THE THREAT FOR THUNDERSTORMS WILL
BE VERY LOW WITH THIS ACTIVITY...WITH TRENDS SUGGESTING NO
LIGHTNING STRIKES OVER THE PAST FEW HOURS...SO I HAVE REMOVED THE
MENTION OF SUCH THIS AFTERNOON. IN ADDITION...WITH THE SLOWER
ONSET OF PRECIP TODAY...IT APPEARS TEMPERATURES WILL BE ABLE TO
WARM TO NEAR 70 IN MOST AREAS AWAY FROM LAKE MICHIGAN...SO I
RAISED HIGH TEMPERATURES TODAY.
KJB
&&
.SHORT TERM...
340 AM CDT
THROUGH MONDAY...
UPPER AIR ANALYSIS EARLY THIS MORNING DEPICTS DEEP UPPER LEVEL LOW
PRESSURE NOW PUSHING INTO WESTERN KANSAS. MULTIPLE VORT MAXES ARE
ROTATING AROUND THE LOW. THE STRONGEST OF THESE EXIST IN TEXAS AND
THROUGH THE CENTRAL PLAINS...WITH SOME SMALLER SCALE WAVES EXTENDING
INTO EASTERN MO/FAR WESTERN IL WERE SOME SCATTERED THUNDERSTORMS
WERE ONGOING. A NORTHERN STREAM SHORTWAVE IS ENTERING THE NORTHERN
PLAINS WITH SOME SHOWERS OUT AHEAD OF IT AS WELL. AT THE
SURFACE...THE COLD FRONT THAT PASSED THROUGH NORTHEAST ILLINOIS AND
NW INDIANA SATURDAY HAS PUSHED INTO CENTRAL ILLINOIS...BUT HAS
LIKELY COMPLETED ITS SOUTHWARD RETREAT AND HAS WASHED OUT OVER THE
PAST FEW HOURS. OVER THE LOCAL AREA...MUCH DRIER NE FLOW EXISTS WITH
DEWPOINTS IN THE MID TO UPPER 20S IN THE CITY TO NEAR 40
SOUTH...THOUGH DEWPOINTS ARE POOLING ALONG THE FRONT IN THE UPPER
40S JUST SOUTH OF THE LOT CWA. THE SURFACE LOW THAT IS EXPECTED TO
DEVELOP FROM THE SOUTHERN STREAM SHORTWAVE IS ALSO TAKING SHAPE OVER
THE SOUTHERN STATES WITH A WARM FRONTAL BOUNDARY EXTENDING FROM
WESTERN ARKANSAS THROUGH THE LOWER TENNESSEE VALLEY. AN EXPANSION OF
LOWER CLOUD TOPS ON IR IMAGERY ALONG AND AHEAD OF THE WARM FRONT IS
OCCURRING.
LOW LEVEL WARM/MOIST ADVECTION WILL CONTINUE ITS SLOW PROGRESSION
NORTHWARD UNDER MODEST SOUTH/SOUTHEAST FLOW. DEEPER MOISTURE/LIFT
REALLY HOLD OFF UNTIL THE AFTERNOON PERIOD ACROSS MOST OF THE AREA.
A SOMEWHAT COMPLICATED EVOLUTION AS A MAIN SURFACE LOW CENTER IS
FORECAST TO STRENGTHEN AS IT LIFTS NORTH THROUGH INDIANA TODAY THEN
FURTHER STRENGTHEN TONIGHT INTO MONDAY WHILE SEVERAL ADDITIONAL
SURFACE LOWS DEVELOP AND EVENTUALLY MERGE WITH THE MAIN LOW CENTER.
THE SURFACE LOW WILL EVENTUALLY BECOME DRIVEN BY A COMBINATION OF
THE SW FLOW AHEAD OF THE SOUTHERN STREAM UPPER LOW AND THE
NORTHERN STREAM SHORTWAVE.
OF NOTE LATER TODAY...EXPECT COVERAGE OF SHOWERS TO INITIALLY BE
SLOW GIVEN THE DRIER AIR PLACE...BUT INCREASING ASCENT ALOFT...LOW
LEVEL SSE ISENTROPIC ASCENT AHEAD OF THE LOW AND WRAPPING AROUND THE
CLOSED CIRCULATION EXTENDING THROUGH 850 AND EVEN 700 MB COMBINED
WITH MODEST LOWER LEVEL FGEN SHOULD ALLOW FOR A BLOSSOMING OF
SHOWERS ACROSS THE AREA LATER THIS AFTERNOON AND EVENING. THE
HIGHEST PWAT AXIS EXPANDS ACROSS INDIANA TODAY BUT SHOULD GET
WRAPPED INTO NE ILLINOIS. RAP MOST UNSTABLE CAPE VALUES RELATIVELY
LOW BUT DO EXPAND FROM SE TO NW THIS AFTERNOON AND THIS COUPLED WITH
THE PUNCH FROM THE DRY SLOT OF THIS SYSTEM MAY ENABLE A FEW T-STORMS
AS WELL...SO SOME OF THE SHOWERS WILL HAVE A MODEST KICK TO THEM IN
THE MODERATE/HEAVY RAINFALL DEPARTMENT. EXPECT THAT NORTH CENTRAL
ILLINOIS MAY BE UNDER A BIT OF SQUEEZE PLAY FROM THESE TWO
SYSTEMS...THUS WHILE SHOWERS ARE STILL EXPECTED...HIGHER CONFIDENCE
EXISTS IN COVERAGE FARTHER EAST.
THIS EVENING THE FIRST MAIN SHORTWAVE WILL BE PASSING NE WHILE THE
MAIN SOUTHERN STREAM ENERGY PASSES EAST THROUGH THE OHIO
VALLEY...AND THE NORTHERN STREAM SHORTWAVE LAGS BEHIND BACK IN
MN/IA. THERE IS ALSO THE LOSS OF DEEPER MOISTURE...THEREFORE EXPECT
SHOWERS TO TAPER/END/TURN TO DRIZZLE POSSIBLY OVERNIGHT FOR A TIME.
THEN MONDAY MORNING WE GET THE COUPLED UPPER LEVEL FORCING FROM THE
NORTHERN STREAM LOW AND SURFACE COLD FRONT WHICH WILL LIKELY BRING
ANOTHER ROUND OF SHOWERS MONDAY MORNING. SHOWERS WILL EASE MONDAY
AFTERNOON. IT WILL BE QUITE BREEZY/WINDY BEHIND THE FRONT ON MONDAY
IN THE COLD ADVECTION REGIME.
KMD
&&
.LONG TERM...
340 AM CDT
MONDAY NIGHT THROUGH SATURDAY...
THE THEME OF THE EXTENDED WILL BE THE UNSEASONABLY COOL WEATHER. A
HIGH AMPLITUDE PATTERN WILL BE IN PLACE WITH STRONG UPPER LEVEL
RIDGING EXTENDING WELL NORTH INTO THE CANADIAN ROCKIES AND SIMILARLY
HIGH AMPLITUDE RIDGING IN THE NORTH ATLANTIC. THAT LEAVES OUR
NORTHERN STREAM SHORTWAVE FROM SUNDAY/MONDAY WITH NO WHERE TO GO.
THIS WILL KEEP MUCH OF THE EASTERN HALF OF THE COUNTY...INCLUDING
OUR REGION...UNDER COOL NORTHWEST FLOW. THIS PATTERN ALSO FAVORED
STRONGLY SHEARED OUT AND ELONGATED VORT MAXES TO PIVOT THROUGH
BRINGING PERIODS OF SHOWERS. WITH PWAT VALUES QUITE LOW IN THIS
AIRMASS...MUCH OF THE PERIOD WILL BE DRY AND EVEN THE SHOWERS SHOULD
NOT BE VERY STRONG. BUT MORE IMPORTANTLY...SEASONAL AVERAGE
HIGHS/LOWS FOR LATE APRIL ARE THE LOWER 60S (MID 60S SOUTH) AND
LOWER 40S RESPECTIVELY...AND MUCH OF THIS PERIOD WILL FEATURE HIGHS
IN THE 50S AND LOWS IN THE MID 30S...POSSIBLY COOLER A NIGHT OR TWO
IF WINDS ARE LIGHTER. TEMPERATURE ANOMALIES ARE NOT THAT EXTREME
THOUGH...SO RECORD COLD IS NOT ANTICIPATED.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* EAST WINDS BETWEEN 10-15KT INTO THIS EVENING.
* WEST WINDS GUSTING TO 20 KT TOMORROW.
* RAIN OVERSPREADS TAF SITES LATER THIS AFTN THRU TONIGHT. MVFR
VSBY UNDER HEAVIER SHOWERS.
* LOW END MVFR CIGS DEVELOP...POSSIBLY IFR CONDS DEVELOP BY 3Z
THRU DAYBREAK MON.
* A SECOND ROUND OF RAIN ARRIVES EARLY MONDAY MORNING.
JEE
//DISCUSSION...UPDATED 12Z...
EAST WINDS CONTINUE TO KEEP THE LOW LEVELS RELATIVELY DRY AND LACK
OF LOW CLOUDS...HOWEVER MOISTURE IS CREEPING NORTH ACROSS SOUTHERN
IL/IN. WINDS WILL OCCASIONALLY GUST TO 20KT THRU MIDDAY...THEN
EXPECT WITH THE ABUNDANCE OF MOISTURE AND RAIN THE GUSTS MAY
BECOME LESS FREQUENT WITH SUSTAINED WINDS INCREASING SLIGHTLY TO
ARND 12-15KT. AS A LOW PRESSURE LIFTS NORTHEAST TOWARDS THE REGION
TONIGHT...CIGS ARE EXPECTED TO LOWER TO MVFR AND LIKELY TO IFR
CONDS WITH BASES ARND 800FT AGL BY 3Z. A FEW GUIDANCE MEMBERS
SUGGEST CIGS MAY DIP FURTHER TO ARND 400FT AGL BY 6Z AS A BRIEF
LULL IN THE PRECIP IS POISED TO LIFT OVERHEAD. AT THIS TIME WILL
MENTION VCSH BY 6Z MON...WHICH MAY END UP AS DRIZZLE OR LGT RAIN.
CIGS WILL REMAIN IFR THRU DAYBREAK MON...UNTIL A TIGHT GRADIENT
RETURNS AND WINDS INCREASE FROM THE WEST/NORTHWEST. THIS SHUD HELP
TO LIFT CIGS BACK TO MVFR AND EVENTUALLY VFR CONDS BY LATER MON.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH CONFIDENCE IN RAIN TIMING...MEDIUM-HIGH CONFIDENCE IN
PRECIP COVERAGE THIS EVENING. MEDIUM CONFIDENCE IN PRECIP
COVERAGE TONIGHT AND MONDAY MORNING.
* MEDIUM CONFIDENCE IN WIND SPEED AND DIRECTION AFTER 18Z.
* HIGH CONFIDENCE IN CIGS BCMG AT LEAST MVFR AND PSBLY
IFR...MEDIUM CONFIDENCE IN TIMING.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...MVFR BECOMING VFR.
TUESDAY...SLGT CHANCE PM SHRA...BUT MAINLY VFR. GUSTY WEST WINDS.
WEDNESDAY...SLGT CHANCE SHRA. MAINLY VFR. WEST-NORTHWEST WINDS.
THURSDAY...VFR. NORTH-NORTHEAST WINDS.
FRIDAY...MAINLY VFR. CHC PM SHRA.
SATURDAY...MAINLY VFR.
BEACHLER
&&
.MARINE...
257 AM CDT
LOW PRESSURE OVER THE CENTRAL PLAINS WILL SLOWLY LIFT NORTHEAST
TOWARDS THE LOWER GREAT LAKES REGION TONIGHT/EARLY MON. GUIDANCE
CONTINUES TO INDICATE THE GRADIENT WILL TIGHTEN ACROSS THE
LAKE...HOWEVER THIS APPEARS TO BE MORE FOCUSED ALONG THE SOUTHERN
TIP OF THE LAKE. WITH THE CONTINUED EASTERLY WINDS...IT IS
POSSIBLE MARGINAL SMALL CRAFT CONDITIONS MAY DEVELOP FOR THE
ILLINOIS SHORELINE LATER TODAY INTO TONIGHT. THE LOW PRESSURE WILL
THEN APPROACH THE LAKE AND BRIEFLY WEAKEN THE GRADIENT EARLY MON.
THEN AS THE LOW LIFTS NORTHEAST LATER IN THE DAY MON...IT WILL
DEEPEN AND MERGE WITH ANOTHER LOW...WHICH WILL CREATE A TIGHT
GRADIENT OVER THE LAKE AND INCREASING WEST/NORTHWEST TUE. AFTER
TUE THE DOMINANT WIND DIRECTION WILL BE NORTHWEST THROUGH MID-
WEEK...BEFORE RELAXING TO THE WEST. THIS WILL ALLOW HIGHER WAVES
TO BE FOCUSED IN THE SOUTHERN HALF OF LAKE MICHIGAN THROUGH MID-
WEEK.
BEACHLER
&&
.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
952 AM CDT SUN APR 19 2015
.UPDATE...
952 AM CDT
I MADE SOME UPDATES TO THE FORECAST FOR TODAY TO RAISE
TEMPERATURES AND PUSH OFF THE TIMING OF THE RAIN CHANCES.
WATER VAPOR IMAGERY INDICATES OUR MID/UPPER LEVEL DISTURBANCE OF
INTEREST FOR LATER TODAY NOW LIFTING NORTHWARD ACROSS WESTERN
KENTUCKY. THIS FEATURE IS CURRENTLY SUPPORTING AN AREA OF
NORTHWARD MOVING SHOWERS ACROSS SOUTHERN PORTIONS OF ILLINOIS AND
INDIANA. THEREFORE...THIS AREA OF SHOWERS WILL GRADUALLY WORK
NORTHWARD ACROSS NORTHEASTERN ILLINOIS AND NORTHWESTERN INDIANA
DURING THE AFTERNOON. IT APPEARS THE THREAT FOR THUNDERSTORMS WILL
BE VERY LOW WITH THIS ACTIVITY...WITH TRENDS SUGGESTING NO
LIGHTNING STRIKES OVER THE PAST FEW HOURS...SO I HAVE REMOVED THE
MENTION OF SUCH THIS AFTERNOON. IN ADDITION...WITH THE SLOWER
ONSET OF PRECIP TODAY...IT APPEARS TEMPERATURES WILL BE ABLE TO
WARM TO NEAR 70 IN MOST AREAS AWAY FROM LAKE MICHIGAN...SO I
RAISED HIGH TEMPERATURES TODAY.
KJB
&&
.SHORT TERM...
340 AM CDT
THROUGH MONDAY...
UPPER AIR ANALYSIS EARLY THIS MORNING DEPICTS DEEP UPPER LEVEL LOW
PRESSURE NOW PUSHING INTO WESTERN KANSAS. MULTIPLE VORT MAXES ARE
ROTATING AROUND THE LOW. THE STRONGEST OF THESE EXIST IN TEXAS AND
THROUGH THE CENTRAL PLAINS...WITH SOME SMALLER SCALE WAVES EXTENDING
INTO EASTERN MO/FAR WESTERN IL WERE SOME SCATTERED THUNDERSTORMS
WERE ONGOING. A NORTHERN STREAM SHORTWAVE IS ENTERING THE NORTHERN
PLAINS WITH SOME SHOWERS OUT AHEAD OF IT AS WELL. AT THE
SURFACE...THE COLD FRONT THAT PASSED THROUGH NORTHEAST ILLINOIS AND
NW INDIANA SATURDAY HAS PUSHED INTO CENTRAL ILLINOIS...BUT HAS
LIKELY COMPLETED ITS SOUTHWARD RETREAT AND HAS WASHED OUT OVER THE
PAST FEW HOURS. OVER THE LOCAL AREA...MUCH DRIER NE FLOW EXISTS WITH
DEWPOINTS IN THE MID TO UPPER 20S IN THE CITY TO NEAR 40
SOUTH...THOUGH DEWPOINTS ARE POOLING ALONG THE FRONT IN THE UPPER
40S JUST SOUTH OF THE LOT CWA. THE SURFACE LOW THAT IS EXPECTED TO
DEVELOP FROM THE SOUTHERN STREAM SHORTWAVE IS ALSO TAKING SHAPE OVER
THE SOUTHERN STATES WITH A WARM FRONTAL BOUNDARY EXTENDING FROM
WESTERN ARKANSAS THROUGH THE LOWER TENNESSEE VALLEY. AN EXPANSION OF
LOWER CLOUD TOPS ON IR IMAGERY ALONG AND AHEAD OF THE WARM FRONT IS
OCCURRING.
LOW LEVEL WARM/MOIST ADVECTION WILL CONTINUE ITS SLOW PROGRESSION
NORTHWARD UNDER MODEST SOUTH/SOUTHEAST FLOW. DEEPER MOISTURE/LIFT
REALLY HOLD OFF UNTIL THE AFTERNOON PERIOD ACROSS MOST OF THE AREA.
A SOMEWHAT COMPLICATED EVOLUTION AS A MAIN SURFACE LOW CENTER IS
FORECAST TO STRENGTHEN AS IT LIFTS NORTH THROUGH INDIANA TODAY THEN
FURTHER STRENGTHEN TONIGHT INTO MONDAY WHILE SEVERAL ADDITIONAL
SURFACE LOWS DEVELOP AND EVENTUALLY MERGE WITH THE MAIN LOW CENTER.
THE SURFACE LOW WILL EVENTUALLY BECOME DRIVEN BY A COMBINATION OF
THE SW FLOW AHEAD OF THE SOUTHERN STREAM UPPER LOW AND THE
NORTHERN STREAM SHORTWAVE.
OF NOTE LATER TODAY...EXPECT COVERAGE OF SHOWERS TO INITIALLY BE
SLOW GIVEN THE DRIER AIR PLACE...BUT INCREASING ASCENT ALOFT...LOW
LEVEL SSE ISENTROPIC ASCENT AHEAD OF THE LOW AND WRAPPING AROUND THE
CLOSED CIRCULATION EXTENDING THROUGH 850 AND EVEN 700 MB COMBINED
WITH MODEST LOWER LEVEL FGEN SHOULD ALLOW FOR A BLOSSOMING OF
SHOWERS ACROSS THE AREA LATER THIS AFTERNOON AND EVENING. THE
HIGHEST PWAT AXIS EXPANDS ACROSS INDIANA TODAY BUT SHOULD GET
WRAPPED INTO NE ILLINOIS. RAP MOST UNSTABLE CAPE VALUES RELATIVELY
LOW BUT DO EXPAND FROM SE TO NW THIS AFTERNOON AND THIS COUPLED WITH
THE PUNCH FROM THE DRY SLOT OF THIS SYSTEM MAY ENABLE A FEW T-STORMS
AS WELL...SO SOME OF THE SHOWERS WILL HAVE A MODEST KICK TO THEM IN
THE MODERATE/HEAVY RAINFALL DEPARTMENT. EXPECT THAT NORTH CENTRAL
ILLINOIS MAY BE UNDER A BIT OF SQUEEZE PLAY FROM THESE TWO
SYSTEMS...THUS WHILE SHOWERS ARE STILL EXPECTED...HIGHER CONFIDENCE
EXISTS IN COVERAGE FARTHER EAST.
THIS EVENING THE FIRST MAIN SHORTWAVE WILL BE PASSING NE WHILE THE
MAIN SOUTHERN STREAM ENERGY PASSES EAST THROUGH THE OHIO
VALLEY...AND THE NORTHERN STREAM SHORTWAVE LAGS BEHIND BACK IN
MN/IA. THERE IS ALSO THE LOSS OF DEEPER MOISTURE...THEREFORE EXPECT
SHOWERS TO TAPER/END/TURN TO DRIZZLE POSSIBLY OVERNIGHT FOR A TIME.
THEN MONDAY MORNING WE GET THE COUPLED UPPER LEVEL FORCING FROM THE
NORTHERN STREAM LOW AND SURFACE COLD FRONT WHICH WILL LIKELY BRING
ANOTHER ROUND OF SHOWERS MONDAY MORNING. SHOWERS WILL EASE MONDAY
AFTERNOON. IT WILL BE QUITE BREEZY/WINDY BEHIND THE FRONT ON MONDAY
IN THE COLD ADVECTION REGIME.
KMD
&&
.LONG TERM...
340 AM CDT
MONDAY NIGHT THROUGH SATURDAY...
THE THEME OF THE EXTENDED WILL BE THE UNSEASONABLY COOL WEATHER. A
HIGH AMPLITUDE PATTERN WILL BE IN PLACE WITH STRONG UPPER LEVEL
RIDGING EXTENDING WELL NORTH INTO THE CANADIAN ROCKIES AND SIMILARLY
HIGH AMPLITUDE RIDGING IN THE NORTH ATLANTIC. THAT LEAVES OUR
NORTHERN STREAM SHORTWAVE FROM SUNDAY/MONDAY WITH NO WHERE TO GO.
THIS WILL KEEP MUCH OF THE EASTERN HALF OF THE COUNTY...INCLUDING
OUR REGION...UNDER COOL NORTHWEST FLOW. THIS PATTERN ALSO FAVORED
STRONGLY SHEARED OUT AND ELONGATED VORT MAXES TO PIVOT THROUGH
BRINGING PERIODS OF SHOWERS. WITH PWAT VALUES QUITE LOW IN THIS
AIRMASS...MUCH OF THE PERIOD WILL BE DRY AND EVEN THE SHOWERS SHOULD
NOT BE VERY STRONG. BUT MORE IMPORTANTLY...SEASONAL AVERAGE
HIGHS/LOWS FOR LATE APRIL ARE THE LOWER 60S (MID 60S SOUTH) AND
LOWER 40S RESPECTIVELY...AND MUCH OF THIS PERIOD WILL FEATURE HIGHS
IN THE 50S AND LOWS IN THE MID 30S...POSSIBLY COOLER A NIGHT OR TWO
IF WINDS ARE LIGHTER. TEMPERATURE ANOMALIES ARE NOT THAT EXTREME
THOUGH...SO RECORD COLD IS NOT ANTICIPATED.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* EAST WINDS BETWEEN 7-12KT INCREASING TO 12-15KT WITH GUSTS UP TO
20KT THRU MIDDAY.
* WEST WINDS GUSTING TO 20 KT TOMORROW.
* RAIN OVERSPREADS TAF SITES LATER THIS AFTN THRU TONIGHT. MVFR
VSBY IS PSBL UNDER HEAVIER SHOWERS.
* LOW END MVFR CIGS DEVELOP...POSSIBLY IFR CONDS DEVELOP BY 3Z
THRU DAYBREAK MON.
JEE
//DISCUSSION...UPDATED 12Z...
EAST WINDS CONTINUE TO KEEP THE LOW LEVELS RELATIVELY DRY AND LACK
OF LOW CLOUDS...HOWEVER MOISTURE IS CREEPING NORTH ACROSS SOUTHERN
IL/IN. WINDS WILL OCCASIONALLY GUST TO 20KT THRU MIDDAY...THEN
EXPECT WITH THE ABUNDANCE OF MOISTURE AND RAIN THE GUSTS MAY
BECOME LESS FREQUENT WITH SUSTAINED WINDS INCREASING SLIGHTLY TO
ARND 12-15KT. AS A LOW PRESSURE LIFTS NORTHEAST TOWARDS THE REGION
TONIGHT...CIGS ARE EXPECTED TO LOWER TO MVFR AND LIKELY TO IFR
CONDS WITH BASES ARND 800FT AGL BY 3Z. A FEW GUIDANCE MEMBERS
SUGGEST CIGS MAY DIP FURTHER TO ARND 400FT AGL BY 6Z AS A BRIEF
LULL IN THE PRECIP IS POISED TO LIFT OVERHEAD. AT THIS TIME WILL
MENTION VCSH BY 6Z MON...WHICH MAY END UP AS DRIZZLE OR LGT RAIN.
CIGS WILL REMAIN IFR THRU DAYBREAK MON...UNTIL A TIGHT GRADIENT
RETURNS AND WINDS INCREASE FROM THE WEST/NORTHWEST. THIS SHUD HELP
TO LIFT CIGS BACK TO MVFR AND EVENTUALLY VFR CONDS BY LATER MON.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* MEDIUM-HIGH CONFIDENCE IN RAIN TIMING AND COVERAGE.
* MEDIUM CONFIDENCE IN WIND SPEED AND DIRECTION AFTER 18Z.
* HIGH CONFIDENCE IN CIGS BCMG AT LEAST MVFR AND PSBLY
IFR...MEDIUM CONFIDENCE IN TIMING.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...MVFR BECOMING VFR.
TUESDAY...SLGT CHANCE PM SHRA...BUT MAINLY VFR. GUSTY WEST WINDS.
WEDNESDAY...SLGT CHANCE SHRA. MAINLY VFR. WEST-NORTHWEST WINDS.
THURSDAY...VFR. NORTH-NORTHEAST WINDS.
FRIDAY...MAINLY VFR. CHC PM SHRA.
SATURDAY...MAINLY VFR.
BEACHLER
&&
.MARINE...
257 AM CDT
LOW PRESSURE OVER THE CENTRAL PLAINS WILL SLOWLY LIFT NORTHEAST
TOWARDS THE LOWER GREAT LAKES REGION TONIGHT/EARLY MON. GUIDANCE
CONTINUES TO INDICATE THE GRADIENT WILL TIGHTEN ACROSS THE
LAKE...HOWEVER THIS APPEARS TO BE MORE FOCUSED ALONG THE SOUTHERN
TIP OF THE LAKE. WITH THE CONTINUED EASTERLY WINDS...IT IS
POSSIBLE MARGINAL SMALL CRAFT CONDITIONS MAY DEVELOP FOR THE
ILLINOIS SHORELINE LATER TODAY INTO TONIGHT. THE LOW PRESSURE WILL
THEN APPROACH THE LAKE AND BRIEFLY WEAKEN THE GRADIENT EARLY MON.
THEN AS THE LOW LIFTS NORTHEAST LATER IN THE DAY MON...IT WILL
DEEPEN AND MERGE WITH ANOTHER LOW...WHICH WILL CREATE A TIGHT
GRADIENT OVER THE LAKE AND INCREASING WEST/NORTHWEST TUE. AFTER
TUE THE DOMINANT WIND DIRECTION WILL BE NORTHWEST THROUGH MID-
WEEK...BEFORE RELAXING TO THE WEST. THIS WILL ALLOW HIGHER WAVES
TO BE FOCUSED IN THE SOUTHERN HALF OF LAKE MICHIGAN THROUGH MID-
WEEK.
BEACHLER
&&
.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
856 AM CDT SUN APR 19 2015
.SHORT TERM...
340 AM CDT
THROUGH MONDAY...
UPPER AIR ANALYSIS EARLY THIS MORNING DEPICTS DEEP UPPER LEVEL LOW
PRESSURE NOW PUSHING INTO WESTERN KANSAS. MULTIPLE VORT MAXES ARE
ROTATING AROUND THE LOW. THE STRONGEST OF THESE EXIST IN TEXAS AND
THROUGH THE CENTRAL PLAINS...WITH SOME SMALLER SCALE WAVES EXTENDING
INTO EASTERN MO/FAR WESTERN IL WERE SOME SCATTERED THUNDERSTORMS
WERE ONGOING. A NORTHERN STREAM SHORTWAVE IS ENTERING THE NORTHERN
PLAINS WITH SOME SHOWERS OUT AHEAD OF IT AS WELL. AT THE
SURFACE...THE COLD FRONT THAT PASSED THROUGH NORTHEAST ILLINOIS AND
NW INDIANA SATURDAY HAS PUSHED INTO CENTRAL ILLINOIS...BUT HAS
LIKELY COMPLETED ITS SOUTHWARD RETREAT AND HAS WASHED OUT OVER THE
PAST FEW HOURS. OVER THE LOCAL AREA...MUCH DRIER NE FLOW EXISTS WITH
DEWPOINTS IN THE MID TO UPPER 20S IN THE CITY TO NEAR 40
SOUTH...THOUGH DEWPOINTS ARE POOLING ALONG THE FRONT IN THE UPPER
40S JUST SOUTH OF THE LOT CWA. THE SURFACE LOW THAT IS EXPECTED TO
DEVELOP FROM THE SOUTHERN STREAM SHORTWAVE IS ALSO TAKING SHAPE OVER
THE SOUTHERN STATES WITH A WARM FRONTAL BOUNDARY EXTENDING FROM
WESTERN ARKANSAS THROUGH THE LOWER TENNESSEE VALLEY. AN EXPANSION OF
LOWER CLOUD TOPS ON IR IMAGERY ALONG AND AHEAD OF THE WARM FRONT IS
OCCURRING.
LOW LEVEL WARM/MOIST ADVECTION WILL CONTINUE ITS SLOW PROGRESSION
NORTHWARD UNDER MODEST SOUTH/SOUTHEAST FLOW. DEEPER MOISTURE/LIFT
REALLY HOLD OFF UNTIL THE AFTERNOON PERIOD ACROSS MOST OF THE AREA.
A SOMEWHAT COMPLICATED EVOLUTION AS A MAIN SURFACE LOW CENTER IS
FORECAST TO STRENGTHEN AS IT LIFTS NORTH THROUGH INDIANA TODAY THEN
FURTHER STRENGTHEN TONIGHT INTO MONDAY WHILE SEVERAL ADDITIONAL
SURFACE LOWS DEVELOP AND EVENTUALLY MERGE WITH THE MAIN LOW CENTER.
THE SURFACE LOW WILL EVENTUALLY BECOME DRIVEN BY A COMBINATION OF
THE SW FLOW AHEAD OF THE SOUTHERN STREAM UPPER LOW AND THE
NORTHERN STREAM SHORTWAVE.
OF NOTE LATER TODAY...EXPECT COVERAGE OF SHOWERS TO INITIALLY BE
SLOW GIVEN THE DRIER AIR PLACE...BUT INCREASING ASCENT ALOFT...LOW
LEVEL SSE ISENTROPIC ASCENT AHEAD OF THE LOW AND WRAPPING AROUND THE
CLOSED CIRCULATION EXTENDING THROUGH 850 AND EVEN 700 MB COMBINED
WITH MODEST LOWER LEVEL FGEN SHOULD ALLOW FOR A BLOSSOMING OF
SHOWERS ACROSS THE AREA LATER THIS AFTERNOON AND EVENING. THE
HIGHEST PWAT AXIS EXPANDS ACROSS INDIANA TODAY BUT SHOULD GET
WRAPPED INTO NE ILLINOIS. RAP MOST UNSTABLE CAPE VALUES RELATIVELY
LOW BUT DO EXPAND FROM SE TO NW THIS AFTERNOON AND THIS COUPLED WITH
THE PUNCH FROM THE DRY SLOT OF THIS SYSTEM MAY ENABLE A FEW T-STORMS
AS WELL...SO SOME OF THE SHOWERS WILL HAVE A MODEST KICK TO THEM IN
THE MODERATE/HEAVY RAINFALL DEPARTMENT. EXPECT THAT NORTH CENTRAL
ILLINOIS MAY BE UNDER A BIT OF SQUEEZE PLAY FROM THESE TWO
SYSTEMS...THUS WHILE SHOWERS ARE STILL EXPECTED...HIGHER CONFIDENCE
EXISTS IN COVERAGE FARTHER EAST.
THIS EVENING THE FIRST MAIN SHORTWAVE WILL BE PASSING NE WHILE THE
MAIN SOUTHERN STREAM ENERGY PASSES EAST THROUGH THE OHIO
VALLEY...AND THE NORTHERN STREAM SHORTWAVE LAGS BEHIND BACK IN
MN/IA. THERE IS ALSO THE LOSS OF DEEPER MOISTURE...THEREFORE EXPECT
SHOWERS TO TAPER/END/TURN TO DRIZZLE POSSIBLY OVERNIGHT FOR A TIME.
THEN MONDAY MORNING WE GET THE COUPLED UPPER LEVEL FORCING FROM THE
NORTHERN STREAM LOW AND SURFACE COLD FRONT WHICH WILL LIKELY BRING
ANOTHER ROUND OF SHOWERS MONDAY MORNING. SHOWERS WILL EASE MONDAY
AFTERNOON. IT WILL BE QUITE BREEZY/WINDY BEHIND THE FRONT ON MONDAY
IN THE COLD ADVECTION REGIME.
KMD
&&
.LONG TERM...
340 AM CDT
MONDAY NIGHT THROUGH SATURDAY...
THE THEME OF THE EXTENDED WILL BE THE UNSEASONABLY COOL WEATHER. A
HIGH AMPLITUDE PATTERN WILL BE IN PLACE WITH STRONG UPPER LEVEL
RIDGING EXTENDING WELL NORTH INTO THE CANADIAN ROCKIES AND SIMILARLY
HIGH AMPLITUDE RIDGING IN THE NORTH ATLANTIC. THAT LEAVES OUR
NORTHERN STREAM SHORTWAVE FROM SUNDAY/MONDAY WITH NO WHERE TO GO.
THIS WILL KEEP MUCH OF THE EASTERN HALF OF THE COUNTY...INCLUDING
OUR REGION...UNDER COOL NORTHWEST FLOW. THIS PATTERN ALSO FAVORED
STRONGLY SHEARED OUT AND ELONGATED VORT MAXES TO PIVOT THROUGH
BRINGING PERIODS OF SHOWERS. WITH PWAT VALUES QUITE LOW IN THIS
AIRMASS...MUCH OF THE PERIOD WILL BE DRY AND EVEN THE SHOWERS SHOULD
NOT BE VERY STRONG. BUT MORE IMPORTANTLY...SEASONAL AVERAGE
HIGHS/LOWS FOR LATE APRIL ARE THE LOWER 60S (MID 60S SOUTH) AND
LOWER 40S RESPECTIVELY...AND MUCH OF THIS PERIOD WILL FEATURE HIGHS
IN THE 50S AND LOWS IN THE MID 30S...POSSIBLY COOLER A NIGHT OR TWO
IF WINDS ARE LIGHTER. TEMPERATURE ANOMALIES ARE NOT THAT EXTREME
THOUGH...SO RECORD COLD IS NOT ANTICIPATED.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* EAST WINDS BETWEEN 7-12KT INCREASING TO 12-15KT WITH GUSTS UP TO
20KT THRU MIDDAY.
* WEST WINDS GUSTING TO 20 KT TOMORROW.
* RAIN OVERSPREADS TAF SITES LATER THIS AFTN THRU TONIGHT. MVFR
VSBY IS PSBL UNDER HEAVIER SHOWERS.
* LOW END MVFR CIGS DEVELOP...POSSIBLY IFR CONDS DEVELOP BY 3Z
THRU DAYBREAK MON.
JEE
//DISCUSSION...UPDATED 12Z...
EAST WINDS CONTINUE TO KEEP THE LOW LEVELS RELATIVELY DRY AND LACK
OF LOW CLOUDS...HOWEVER MOISTURE IS CREEPING NORTH ACROSS SOUTHERN
IL/IN. WINDS WILL OCCASIONALLY GUST TO 20KT THRU MIDDAY...THEN
EXPECT WITH THE ABUNDANCE OF MOISTURE AND RAIN THE GUSTS MAY
BECOME LESS FREQUENT WITH SUSTAINED WINDS INCREASING SLIGHTLY TO
ARND 12-15KT. AS A LOW PRESSURE LIFTS NORTHEAST TOWARDS THE REGION
TONIGHT...CIGS ARE EXPECTED TO LOWER TO MVFR AND LIKELY TO IFR
CONDS WITH BASES ARND 800FT AGL BY 3Z. A FEW GUIDANCE MEMBERS
SUGGEST CIGS MAY DIP FURTHER TO ARND 400FT AGL BY 6Z AS A BRIEF
LULL IN THE PRECIP IS POISED TO LIFT OVERHEAD. AT THIS TIME WILL
MENTION VCSH BY 6Z MON...WHICH MAY END UP AS DRIZZLE OR LGT RAIN.
CIGS WILL REMAIN IFR THRU DAYBREAK MON...UNTIL A TIGHT GRADIENT
RETURNS AND WINDS INCREASE FROM THE WEST/NORTHWEST. THIS SHUD HELP
TO LIFT CIGS BACK TO MVFR AND EVENTUALLY VFR CONDS BY LATER MON.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* MEDIUM-HIGH CONFIDENCE IN RAIN TIMING AND COVERAGE.
* MEDIUM CONFIDENCE IN WIND SPEED AND DIRECTION AFTER 18Z.
* HIGH CONFIDENCE IN CIGS BCMG AT LEAST MVFR AND PSBLY
IFR...MEDIUM CONFIDENCE IN TIMING.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...MVFR BECOMING VFR.
TUESDAY...SLGT CHANCE PM SHRA...BUT MAINLY VFR. GUSTY WEST WINDS.
WEDNESDAY...SLGT CHANCE SHRA. MAINLY VFR. WEST-NORTHWEST WINDS.
THURSDAY...VFR. NORTH-NORTHEAST WINDS.
FRIDAY...MAINLY VFR. CHC PM SHRA.
SATURDAY...MAINLY VFR.
BEACHLER
&&
.MARINE...
257 AM CDT
LOW PRESSURE OVER THE CENTRAL PLAINS WILL SLOWLY LIFT NORTHEAST
TOWARDS THE LOWER GREAT LAKES REGION TONIGHT/EARLY MON. GUIDANCE
CONTINUES TO INDICATE THE GRADIENT WILL TIGHTEN ACROSS THE
LAKE...HOWEVER THIS APPEARS TO BE MORE FOCUSED ALONG THE SOUTHERN
TIP OF THE LAKE. WITH THE CONTINUED EASTERLY WINDS...IT IS
POSSIBLE MARGINAL SMALL CRAFT CONDITIONS MAY DEVELOP FOR THE
ILLINOIS SHORELINE LATER TODAY INTO TONIGHT. THE LOW PRESSURE WILL
THEN APPROACH THE LAKE AND BRIEFLY WEAKEN THE GRADIENT EARLY MON.
THEN AS THE LOW LIFTS NORTHEAST LATER IN THE DAY MON...IT WILL
DEEPEN AND MERGE WITH ANOTHER LOW...WHICH WILL CREATE A TIGHT
GRADIENT OVER THE LAKE AND INCREASING WEST/NORTHWEST TUE. AFTER
TUE THE DOMINANT WIND DIRECTION WILL BE NORTHWEST THROUGH MID-
WEEK...BEFORE RELAXING TO THE WEST. THIS WILL ALLOW HIGHER WAVES
TO BE FOCUSED IN THE SOUTHERN HALF OF LAKE MICHIGAN THROUGH MID-
WEEK.
BEACHLER
&&
.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:
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
647 AM CDT SUN APR 19 2015
.SHORT TERM...
340 AM CDT
THROUGH MONDAY...
UPPER AIR ANALYSIS EARLY THIS MORNING DEPICTS DEEP UPPER LEVEL LOW
PRESSURE NOW PUSHING INTO WESTERN KANSAS. MULTIPLE VORT MAXES ARE
ROTATING AROUND THE LOW. THE STRONGEST OF THESE EXIST IN TEXAS AND
THROUGH THE CENTRAL PLAINS...WITH SOME SMALLER SCALE WAVES EXTENDING
INTO EASTERN MO/FAR WESTERN IL WERE SOME SCATTERED THUNDERSTORMS
WERE ONGOING. A NORTHERN STREAM SHORTWAVE IS ENTERING THE NORTHERN
PLAINS WITH SOME SHOWERS OUT AHEAD OF IT AS WELL. AT THE
SURFACE...THE COLD FRONT THAT PASSED THROUGH NORTHEAST ILLINOIS AND
NW INDIANA SATURDAY HAS PUSHED INTO CENTRAL ILLINOIS...BUT HAS
LIKELY COMPLETED ITS SOUTHWARD RETREAT AND HAS WASHED OUT OVER THE
PAST FEW HOURS. OVER THE LOCAL AREA...MUCH DRIER NE FLOW EXISTS WITH
DEWPOINTS IN THE MID TO UPPER 20S IN THE CITY TO NEAR 40
SOUTH...THOUGH DEWPOINTS ARE POOLING ALONG THE FRONT IN THE UPPER
40S JUST SOUTH OF THE LOT CWA. THE SURFACE LOW THAT IS EXPECTED TO
DEVELOP FROM THE SOUTHERN STREAM SHORTWAVE IS ALSO TAKING SHAPE OVER
THE SOUTHERN STATES WITH A WARM FRONTAL BOUNDARY EXTENDING FROM
WESTERN ARKANSAS THROUGH THE LOWER TENNESSEE VALLEY. AN EXPANSION OF
LOWER CLOUD TOPS ON IR IMAGERY ALONG AND AHEAD OF THE WARM FRONT IS
OCCURRING.
LOW LEVEL WARM/MOIST ADVECTION WILL CONTINUE ITS SLOW PROGRESSION
NORTHWARD UNDER MODEST SOUTH/SOUTHEAST FLOW. DEEPER MOISTURE/LIFT
REALLY HOLD OFF UNTIL THE AFTERNOON PERIOD ACROSS MOST OF THE AREA.
A SOMEWHAT COMPLICATED EVOLUTION AS A MAIN SURFACE LOW CENTER IS
FORECAST TO STRENGTHEN AS IT LIFTS NORTH THROUGH INDIANA TODAY THEN
FURTHER STRENGTHEN TONIGHT INTO MONDAY WHILE SEVERAL ADDITIONAL
SURFACE LOWS DEVELOP AND EVENTUALLY MERGE WITH THE MAIN LOW CENTER.
THE SURFACE LOW WILL EVENTUALLY BECOME DRIVEN BY A COMBINATION OF
THE SW FLOW AHEAD OF THE SOUTHERN STREAM UPPER LOW AND THE
NORTHERN STREAM SHORTWAVE.
OF NOTE LATER TODAY...EXPECT COVERAGE OF SHOWERS TO INITIALLY BE
SLOW GIVEN THE DRIER AIR PLACE...BUT INCREASING ASCENT ALOFT...LOW
LEVEL SSE ISENTROPIC ASCENT AHEAD OF THE LOW AND WRAPPING AROUND THE
CLOSED CIRCULATION EXTENDING THROUGH 850 AND EVEN 700 MB COMBINED
WITH MODEST LOWER LEVEL FGEN SHOULD ALLOW FOR A BLOSSOMING OF
SHOWERS ACROSS THE AREA LATER THIS AFTERNOON AND EVENING. THE
HIGHEST PWAT AXIS EXPANDS ACROSS INDIANA TODAY BUT SHOULD GET
WRAPPED INTO NE ILLINOIS. RAP MOST UNSTABLE CAPE VALUES RELATIVELY
LOW BUT DO EXPAND FROM SE TO NW THIS AFTERNOON AND THIS COUPLED WITH
THE PUNCH FROM THE DRY SLOT OF THIS SYSTEM MAY ENABLE A FEW T-STORMS
AS WELL...SO SOME OF THE SHOWERS WILL HAVE A MODEST KICK TO THEM IN
THE MODERATE/HEAVY RAINFALL DEPARTMENT. EXPECT THAT NORTH CENTRAL
ILLINOIS MAY BE UNDER A BIT OF SQUEEZE PLAY FROM THESE TWO
SYSTEMS...THUS WHILE SHOWERS ARE STILL EXPECTED...HIGHER CONFIDENCE
EXISTS IN COVERAGE FARTHER EAST.
THIS EVENING THE FIRST MAIN SHORTWAVE WILL BE PASSING NE WHILE THE
MAIN SOUTHERN STREAM ENERGY PASSES EAST THROUGH THE OHIO
VALLEY...AND THE NORTHERN STREAM SHORTWAVE LAGS BEHIND BACK IN
MN/IA. THERE IS ALSO THE LOSS OF DEEPER MOISTURE...THEREFORE EXPECT
SHOWERS TO TAPER/END/TURN TO DRIZZLE POSSIBLY OVERNIGHT FOR A TIME.
THEN MONDAY MORNING WE GET THE COUPLED UPPER LEVEL FORCING FROM THE
NORTHERN STREAM LOW AND SURFACE COLD FRONT WHICH WILL LIKELY BRING
ANOTHER ROUND OF SHOWERS MONDAY MORNING. SHOWERS WILL EASE MONDAY
AFTERNOON. IT WILL BE QUITE BREEZY/WINDY BEHIND THE FRONT ON MONDAY
IN THE COLD ADVECTION REGIME.
KMD
&&
.LONG TERM...
340 AM CDT
MONDAY NIGHT THROUGH SATURDAY...
THE THEME OF THE EXTENDED WILL BE THE UNSEASONABLY COOL WEATHER. A
HIGH AMPLITUDE PATTERN WILL BE IN PLACE WITH STRONG UPPER LEVEL
RIDGING EXTENDING WELL NORTH INTO THE CANADIAN ROCKIES AND SIMILARLY
HIGH AMPLITUDE RIDGING IN THE NORTH ATLANTIC. THAT LEAVES OUR
NORTHERN STREAM SHORTWAVE FROM SUNDAY/MONDAY WITH NO WHERE TO GO.
THIS WILL KEEP MUCH OF THE EASTERN HALF OF THE COUNTY...INCLUDING
OUR REGION...UNDER COOL NORTHWEST FLOW. THIS PATTERN ALSO FAVORED
STRONGLY SHEARED OUT AND ELONGATED VORT MAXES TO PIVOT THROUGH
BRINGING PERIODS OF SHOWERS. WITH PWAT VALUES QUITE LOW IN THIS
AIRMASS...MUCH OF THE PERIOD WILL BE DRY AND EVEN THE SHOWERS SHOULD
NOT BE VERY STRONG. BUT MORE IMPORTANTLY...SEASONAL AVERAGE
HIGHS/LOWS FOR LATE APRIL ARE THE LOWER 60S (MID 60S SOUTH) AND
LOWER 40S RESPECTIVELY...AND MUCH OF THIS PERIOD WILL FEATURE HIGHS
IN THE 50S AND LOWS IN THE MID 30S...POSSIBLY COOLER A NIGHT OR TWO
IF WINDS ARE LIGHTER. TEMPERATURE ANOMALIES ARE NOT THAT EXTREME
THOUGH...SO RECORD COLD IS NOT ANTICIPATED.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* EAST WINDS BETWEEN 7-12KT INCREASING TO 12-15KT WITH GUSTS UP TO
20KT THRU MIDDAY.
* WINDS TURN NORTH LATE TONIGHT...THEN NORTHWEST EARLY MON.
* RAIN OVERSPREADS TAF SITES LATER THIS AFTN THRU TONIGHT.
* LOW END MVFR CIGS DEVELOP...POSSIBLY IFR CONDS DEVELOP BY 3Z
THRU DAYBREAK MON.
BEACHLER
//DISCUSSION...UPDATED 12Z...
EAST WINDS CONTINUE TO KEEP THE LOW LEVELS RELATIVELY DRY AND LACK
OF LOW CLOUDS...HOWEVER MOISTURE IS CREEPING NORTH ACROSS SOUTHERN
IL/IN. WINDS WILL OCCASIONALLY GUST TO 20KT THRU MIDDAY...THEN
EXPECT WITH THE ABUNDANCE OF MOISTURE AND RAIN THE GUSTS MAY
BECOME LESS FREQUENT WITH SUSTAINED WINDS INCREASING SLIGHTLY TO
ARND 12-15KT. AS A LOW PRESSURE LIFTS NORTHEAST TOWARDS THE REGION
TONIGHT...CIGS ARE EXPECTED TO LOWER TO MVFR AND LIKELY TO IFR
CONDS WITH BASES ARND 800FT AGL BY 3Z. A FEW GUIDANCE MEMBERS
SUGGEST CIGS MAY DIP FURTHER TO ARND 400FT AGL BY 6Z AS A BRIEF
LULL IN THE PRECIP IS POISED TO LIFT OVERHEAD. AT THIS TIME WILL
MENTION VCSH BY 6Z MON...WHICH MAY END UP AS DRIZZLE OR LGT RAIN.
CIGS WILL REMAIN IFR THRU DAYBREAK MON...UNTIL A TIGHT GRADIENT
RETURNS AND WINDS INCREASE FROM THE WEST/NORTHWEST. THIS SHUD HELP
TO LIFT CIGS BACK TO MVFR AND EVENTUALLY VFR CONDS BY LATER MON.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* HIGH CONFIDENCE IN ALL ELEMENTS THROUGH 18Z...MEDIUM CONFIDENCE
IN WIND DIR/SPEED AFT 18Z.
* MEDIUM CONFIDENCE IN PRECIP TIMING/COVERAGE.
* HIGH CONFIDENCE IN CIGS DIMINISHING TO AT LEAST MVFR CONDS AFT
21Z...AND MEDIUM CONFIDENCE IN CIGS BECOMING IFR AFT 3Z MON.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...MVFR BECOMING VFR.
TUESDAY...SLGT CHANCE PM SHRA...BUT MAINLY VFR. GUSTY WEST WINDS.
WEDNESDAY...SLGT CHANCE SHRA. MAINLY VFR. WEST-NORTHWEST WINDS.
THURSDAY...VFR. NORTH-NORTHEAST WINDS.
FRIDAY...MAINLY VFR. CHC PM SHRA.
SATURDAY...MAINLY VFR.
BEACHLER
&&
.MARINE...
257 AM CDT
LOW PRESSURE OVER THE CENTRAL PLAINS WILL SLOWLY LIFT NORTHEAST
TOWARDS THE LOWER GREAT LAKES REGION TONIGHT/EARLY MON. GUIDANCE
CONTINUES TO INDICATE THE GRADIENT WILL TIGHTEN ACROSS THE
LAKE...HOWEVER THIS APPEARS TO BE MORE FOCUSED ALONG THE SOUTHERN
TIP OF THE LAKE. WITH THE CONTINUED EASTERLY WINDS...IT IS
POSSIBLE MARGINAL SMALL CRAFT CONDITIONS MAY DEVELOP FOR THE
ILLINOIS SHORELINE LATER TODAY INTO TONIGHT. THE LOW PRESSURE WILL
THEN APPROACH THE LAKE AND BRIEFLY WEAKEN THE GRADIENT EARLY MON.
THEN AS THE LOW LIFTS NORTHEAST LATER IN THE DAY MON...IT WILL
DEEPEN AND MERGE WITH ANOTHER LOW...WHICH WILL CREATE A TIGHT
GRADIENT OVER THE LAKE AND INCREASING WEST/NORTHWEST TUE. AFTER
TUE THE DOMINANT WIND DIRECTION WILL BE NORTHWEST THROUGH MID-
WEEK...BEFORE RELAXING TO THE WEST. THIS WILL ALLOW HIGHER WAVES
TO BE FOCUSED IN THE SOUTHERN HALF OF LAKE MICHIGAN THROUGH MID-
WEEK.
BEACHLER
&&
.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:
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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS LINCOLN IL
642 AM CDT SUN APR 19 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 328 AM CDT SUN APR 19 2015
LATEST WATER VAPOR IMAGERY CONTINUES TO SHOW CLOSED UPPER LOW OVER
EASTERN COLORADO, WITH LEAD SHORT-WAVE ROTATING AROUND THIS FEATURE
ACROSS ARKANSAS/LOUISIANA. AS THIS WAVE LIFTS NORTHWARD, PRECIP
WILL EVENTUALLY SPREAD INTO CENTRAL ILLINOIS TODAY. 07Z/2AM RADAR
MOSAIC SHOWS DRY CONDITIONS ACROSS THE ENTIRE KILX CWA: HOWEVER,
SHOWERS ARE BEGINNING TO DEVELOP AND BECOME MORE WIDESPREAD FURTHER
SOUTH ACROSS WESTERN KENTUCKY AND FAR SOUTHERN ILLINOIS. BASED ON
RADAR TIMING TOOLS AND LATEST HRRR FORECAST, THINK SCATTERED SHOWERS
WILL ARRIVE SOUTH OF I-70 OVER THE NEXT COUPLE OF HOURS, THEN WILL
SPREAD NORTHWARD TOWARD THE I-74 CORRIDOR BY MIDDAY. HAVE ADJUSTED
POPS TO ACCOUNT FOR THE SLOWER ARRIVAL OF PRECIP DURING THE MORNING,
THEN HAVE GONE WITH CATEGORICAL POPS ACROSS THE BOARD THIS
AFTERNOON. ASIDE FROM SOME SBCAPES OF AROUND 1000J/KG ACROSS THE
FAR SE CWA, FORECAST SOUNDINGS REMAIN FAIRLY STABLE TODAY. AS A
RESULT, AM EXPECTING MAINLY SHOWERS WITH JUST A FEW EMBEDDED
THUNDERSTORMS. DUE TO CLOUD COVER AND PRECIP, HIGH TEMPERATURES
WILL BE SEVERAL DEGREES COOLER THAN IN RECENT DAYS, WITH READINGS
MAINLY IN THE 60S. WARMEST TEMPS OF AROUND 70 WILL BE FOCUSED
ALONG/WEST OF THE ILLINOIS RIVER WHERE PRECIP WILL BE SLOWEST TO
ARRIVE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 328 AM CDT SUN APR 19 2015
LEAD SHORT-WAVE WILL LIFT INTO NORTHERN ILLINOIS/INDIANA BY EARLY
EVENING, LIKELY LEADING TO A TEMPORARY LULL IN THE SHOWERS.
MEANWHILE, THE MAIN UPPER LOW WILL GET A SOLID PUSH EASTWARD AND
WILL ARRIVE ACROSS ILLINOIS LATER TONIGHT INTO MONDAY MORNING.
SHOWERS AND PERHAPS A THUNDERSTORM WILL ACCOMPANY THIS FEATURE, SO
WILL CONTINUE LIKELY POPS TONIGHT THROUGH MONDAY MORNING. ONCE THE
500MB VORT MAX AND THE ASSOCIATED SURFACE COLD FRONT PASS TO THE
EAST, RAIN CHANCES WILL COME TO AN END BY MONDAY AFTERNOON. THANKS
TO A TIGHT PRESSURE GRADIENT BEHIND THE DEPARTING FRONT, STRONG W/NW
WINDS GUSTING TO BETWEEN 25 AND 30 MPH WILL DEVELOP ON MONDAY. THE
WINDS WILL SUBSIDE FOR A TIME MONDAY NIGHT, BUT WILL ONCE AGAIN
INCREASE MARKEDLY DURING THE DAY TUESDAY. HIGH TEMPERATURES BOTH
DAYS WILL REMAIN IN THE LOWER 60S, WHILE OVERNIGHT LOWS DIP INTO THE
UPPER 30S AND LOWER 40S.
00Z APR 19 MODELS HAVE COME INTO MUCH BETTER AGREEMENT CONCERNING
THE EXTENDED FORECAST, WITH CONSENSUS FEATURING A CHILLY AND LARGELY
DRY WEEK AHEAD. BOTH THE GFS AND ECMWF INDICATE A WEAK COLD FRONT
WILL PASS THROUGH CENTRAL ILLINOIS TUESDAY NIGHT INTO WEDNESDAY:
HOWEVER, THEY DISAGREE ON HOW MUCH PRECIP IT WILL GENERATE. THE GFS
IS SLIGHTLY WETTER AND FASTER WITH FROPA, WHILE THE ECMWF IS DRIER
AND ABOUT 6 HOURS SLOWER WITH THE FRONT. DUE TO THE STRONG
NORTHWESTERLY UPPER FLOW PATTERN IN PLACE ACROSS THE MIDWEST, THINK
THE FASTER GFS IS THE WAY TO GO WITH TIMING, BUT THINK THE DRIER
ECMWF IS BETTER WITH QPF AS DEEP MOISTURE WILL BE LACKING WITH THIS
FEATURE. AS A RESULT, HAVE OPTED TO CARRY LOW CHANCE POPS
EVERYWHERE TUESDAY NIGHT, THEN ONLY ACROSS THE SE CWA ON WEDNESDAY.
ONCE THE FRONT PASSES, A COOL/CANADIAN AIRMASS WILL SETTLE INTO THE
REGION FOR THE MIDDLE AND END OF THE WEEK. HIGH TEMPERATURES WILL
STRUGGLE TO REACH THE 60 DEGREE MARK ON BOTH WEDNESDAY AND THURSDAY,
WHILE LOWS DROP INTO THE 30S. COLDEST MORNING MAY END UP BEING
FRIDAY MORNING, WHEN RIDGE OF HIGH PRESSURE IS OVERHEAD AND WINDS
WILL BE LIGHTEST. WILL NEED TO KEEP AN EYE ON TEMPS, AS FROST
ADVISORIES WILL BE POSSIBLE ACROSS PARTS OF CENTRAL/SOUTHEAST
ILLINOIS LATER THIS WEEK. AFTER THAT, ANOTHER SYSTEM WILL APPROACH
FROM THE SOUTHWEST BY THE END OF THE WEEK: HOWEVER, ITS INFLUENCE
LIKELY WILL NOT BE FELT UNTIL FRIDAY NIGHT/SATURDAY AT THE EARLIEST.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 542 AM CDT SUN APR 19 2015
MID AND HIGH CLOUDS WILL CONTINUE OVER THE AREA THIS MORNING,
EFFECTING ALL TAF SITES UNTIL THE PCPN MOVES INTO THE SITES. WILL
START ALL SITES WITH VCSH AS THE PCPN MOVES NORTHWARD AND
INITIALLY SATURATES THE LOWER LEVELS, DURING THE MORNING HOURS.
THEN BETWEEN 10AM AND NOON, PCPN WILL BECOME MORE DOMINATE AND
STEADY. TIMING OF ONSET OF PCPN WAS TAKEN FROM A BLEND OF THE
BUFKIT DATA, NAM12, HRRR, AND RADAR TRENDS. MVFR CIGS AND VIS
WILL ARRIVE WITH THE RAIN AND CONTINUE THROUGH REST OF TAF VALID
PERIOD. PCPN COULD LET UP SOME LATE THIS EVENING, SO HAVE ADDED
ANOTHER LINE FOR VCSH AFTER THE BULK OF THE RAIN MOVES THROUGH,
AND BEFORE THE NEXT BATCH ARRIVES LATE TONIGHT/EARLY TOMORROW
MORNING. WINDS WILL BE EASTERLY TO START, BUT THEN BECOME
SOUTHEASTERLY AS THE SYSTEM GET CLOSER TO THE SITES. WITH THE
SURFACE LOW PRESSURE AREA MOVING RIGHT OVER THE TAFS, WINDS WILL
BE VARIABLE, ENDING AT WEST TO SOUTHWEST LATER TONIGHT.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
420 AM CDT SUN APR 19 2015
.SHORT TERM...
340 AM CDT
THROUGH MONDAY...
UPPER AIR ANALYSIS EARLY THIS MORNING DEPICTS DEEP UPPER LEVEL LOW
PRESSURE NOW PUSHING INTO WESTERN KANSAS. MULTIPLE VORT MAXES ARE
ROTATING AROUND THE LOW. THE STRONGEST OF THESE EXIST IN TEXAS AND
THROUGH THE CENTRAL PLAINS...WITH SOME SMALLER SCALE WAVES EXTENDING
INTO EASTERN MO/FAR WESTERN IL WERE SOME SCATTERED THUNDERSTORMS
WERE ONGOING. A NORTHERN STREAM SHORTWAVE IS ENTERING THE NORTHERN
PLAINS WITH SOME SHOWERS OUT AHEAD OF IT AS WELL. AT THE
SURFACE...THE COLD FRONT THAT PASSED THROUGH NORTHEAST ILLINOIS AND
NW INDIANA SATURDAY HAS PUSHED INTO CENTRAL ILLINOIS...BUT HAS
LIKELY COMPLETED ITS SOUTHWARD RETREAT AND HAS WASHED OUT OVER THE
PAST FEW HOURS. OVER THE LOCAL AREA...MUCH DRIER NE FLOW EXISTS WITH
DEWPOINTS IN THE MID TO UPPER 20S IN THE CITY TO NEAR 40
SOUTH...THOUGH DEWPOINTS ARE POOLING ALONG THE FRONT IN THE UPPER
40S JUST SOUTH OF THE LOT CWA. THE SURFACE LOW THAT IS EXPECTED TO
DEVELOP FROM THE SOUTHERN STREAM SHORTWAVE IS ALSO TAKING SHAPE OVER
THE SOUTHERN STATES WITH A WARM FRONTAL BOUNDARY EXTENDING FROM
WESTERN ARKANSAS THROUGH THE LOWER TENNESSEE VALLEY. AN EXPANSION OF
LOWER CLOUD TOPS ON IR IMAGERY ALONG AND AHEAD OF THE WARM FRONT IS
OCCURRING.
LOW LEVEL WARM/MOIST ADVECTION WILL CONTINUE ITS SLOW PROGRESSION
NORTHWARD UNDER MODEST SOUTH/SOUTHEAST FLOW. DEEPER MOISTURE/LIFT
REALLY HOLD OFF UNTIL THE AFTERNOON PERIOD ACROSS MOST OF THE AREA.
A SOMEWHAT COMPLICATED EVOLUTION AS A MAIN SURFACE LOW CENTER IS
FORECAST TO STRENGTHEN AS IT LIFTS NORTH THROUGH INDIANA TODAY THEN
FURTHER STRENGTHEN TONIGHT INTO MONDAY WHILE SEVERAL ADDITIONAL
SURFACE LOWS DEVELOP AND EVENTUALLY MERGE WITH THE MAIN LOW CENTER.
THE SURFACE LOW WILL EVENTUALLY BECOME DRIVEN BY A COMBINATION OF
THE SW FLOW AHEAD OF THE SOUTHERN STREAM UPPER LOW AND THE
NORTHERN STREAM SHORTWAVE.
OF NOTE LATER TODAY...EXPECT COVERAGE OF SHOWERS TO INITIALLY BE
SLOW GIVEN THE DRIER AIR PLACE...BUT INCREASING ASCENT ALOFT...LOW
LEVEL SSE ISENTROPIC ASCENT AHEAD OF THE LOW AND WRAPPING AROUND THE
CLOSED CIRCULATION EXTENDING THROUGH 850 AND EVEN 700 MB COMBINED
WITH MODEST LOWER LEVEL FGEN SHOULD ALLOW FOR A BLOSSOMING OF
SHOWERS ACROSS THE AREA LATER THIS AFTERNOON AND EVENING. THE
HIGHEST PWAT AXIS EXPANDS ACROSS INDIANA TODAY BUT SHOULD GET
WRAPPED INTO NE ILLINOIS. RAP MOST UNSTABLE CAPE VALUES RELATIVELY
LOW BUT DO EXPAND FROM SE TO NW THIS AFTERNOON AND THIS COUPLED WITH
THE PUNCH FROM THE DRY SLOT OF THIS SYSTEM MAY ENABLE A FEW T-STORMS
AS WELL...SO SOME OF THE SHOWERS WILL HAVE A MODEST KICK TO THEM IN
THE MODERATE/HEAVY RAINFALL DEPARTMENT. EXPECT THAT NORTH CENTRAL
ILLINOIS MAY BE UNDER A BIT OF SQUEEZE PLAY FROM THESE TWO
SYSTEMS...THUS WHILE SHOWERS ARE STILL EXPECTED...HIGHER CONFIDENCE
EXISTS IN COVERAGE FARTHER EAST.
THIS EVENING THE FIRST MAIN SHORTWAVE WILL BE PASSING NE WHILE THE
MAIN SOUTHERN STREAM ENERGY PASSES EAST THROUGH THE OHIO
VALLEY...AND THE NORTHERN STREAM SHORTWAVE LAGS BEHIND BACK IN
MN/IA. THERE IS ALSO THE LOSS OF DEEPER MOISTURE...THEREFORE EXPECT
SHOWERS TO TAPER/END/TURN TO DRIZZLE POSSIBLY OVERNIGHT FOR A TIME.
THEN MONDAY MORNING WE GET THE COUPLED UPPER LEVEL FORCING FROM THE
NORTHERN STREAM LOW AND SURFACE COLD FRONT WHICH WILL LIKELY BRING
ANOTHER ROUND OF SHOWERS MONDAY MORNING. SHOWERS WILL EASE MONDAY
AFTERNOON. IT WILL BE QUITE BREEZY/WINDY BEHIND THE FRONT ON MONDAY
IN THE COLD ADVECTION REGIME.
KMD
&&
.LONG TERM...
340 AM CDT
MONDAY NIGHT THROUGH SATURDAY...
THE THEME OF THE EXTENDED WILL BE THE UNSEASONABLY COOL WEATHER. A
HIGH AMPLITUDE PATTERN WILL BE IN PLACE WITH STRONG UPPER LEVEL
RIDGING EXTENDING WELL NORTH INTO THE CANADIAN ROCKIES AND SIMILARLY
HIGH AMPLITUDE RIDGING IN THE NORTH ATLANTIC. THAT LEAVES OUR
NORTHERN STREAM SHORTWAVE FROM SUNDAY/MONDAY WITH NO WHERE TO GO.
THIS WILL KEEP MUCH OF THE EASTERN HALF OF THE COUNTY...INCLUDING
OUR REGION...UNDER COOL NORTHWEST FLOW. THIS PATTERN ALSO FAVORED
STRONGLY SHEARED OUT AND ELONGATED VORT MAXES TO PIVOT THROUGH
BRINGING PERIODS OF SHOWERS. WITH PWAT VALUES QUITE LOW IN THIS
AIRMASS...MUCH OF THE PERIOD WILL BE DRY AND EVEN THE SHOWERS SHOULD
NOT BE VERY STRONG. BUT MORE IMPORTANTLY...SEASONAL AVERAGE
HIGHS/LOWS FOR LATE APRIL ARE THE LOWER 60S (MID 60S SOUTH) AND
LOWER 40S RESPECTIVELY...AND MUCH OF THIS PERIOD WILL FEATURE HIGHS
IN THE 50S AND LOWS IN THE MID 30S...POSSIBLY COOLER A NIGHT OR TWO
IF WINDS ARE LIGHTER. TEMPERATURE ANOMALIES ARE NOT THAT EXTREME
THOUGH...SO RECORD COLD IS NOT ANTICIPATED.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 09Z...
* EAST WINDS ARND 6 TO 10 KT...OCCASIONAL GUSTS TO 17KT.
* WINDS TURN NORTH LATE TONIGHT...THEN NORTHWEST EARLY MON.
* RAIN OVERSPREAD TAF SITES LATE THIS AFTN THRU TONIGHT.
* POSSIBLE LOW END MVFR CIGS OR PATCHY IFR CIGS DEVELOPING.
BEACHLER
//DISCUSSION...UPDATED 06Z...
WITH THE DEPARTING HIGH PRESSURE TO THE EAST...MID-LVL MOISTURE
WAS SLOWLY LIFTING NORTH ACROSS THE NORTHERN IL/NORTHWEST IN
AIRFIELDS. THIS HAS ALLOWED A CIRRUS CLOUD DECK TO THICKEN...AND
ADDITIONAL MOISTURE IS EXPECTED TO LIFT NORTHEAST AS A LOW
PRESSURE SYSTEM NEARS THE REGION LATER TONIGHT INTO EARLY MON.
GUIDANCE HAS BEEN SLOWLY TRENDING LATER WITH THE ARRIVAL OF PRECIP
UNTIL AFT 18Z...AND MAY NOT BE CLOSER TO 23Z. WILL CONTINUE TO
MENTION VCSH BUT PUSH IT TO 20Z...THEN EXPECT THE COVERAGE TO
INCREASE IN PRECIP CLOSER TO 23Z. WITH THE STEADILY THICKEN AND
LOWER CLOUDS...THE CHALLENGE IS ALSO ON WIND SPEEDS. IT IS STILL
POSSIBLE GUSTS WILL NEED TO BE PUT BACK INTO THE TAF...ALTHOUGH
WITH THE ABUNDANT CLOUD COVER...IT IS QUESTIONABLE HOW FREQUENT
GUSTS WILL OCCUR AT THE TAF SITES. SO HAVE REMOVED THE MENTION AT
THIS TIME AND JUST INCREASED THE SUSTAINED WINDS. THEN AT SOME
POINT LATE THIS EVENING CIGS ARE EXPECTED TO QUICKLY DIP TO MVFR
AND POSSIBLY TO IFR CONDS. PRECIP COVERAGE WILL BEGIN TO DIMINISH
EARLY MON...AND MAY TREND TOWARDS PATCHY DRIZZLE WHICH MAY ALSO
FURTHER LOWER CIGS AND VSBYS EARLY MON MORNING.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 09Z...
* HIGH CONFIDENCE IN ALL ELEMENTS THROUGH 18Z...MEDIUM CONFIDENCE
IN WIND DIR/SPEED AFT 18Z.
* MEDIUM CONFIDENCE IN PRECIP TIMING/COVERAGE.
* HIGH CONFIDENCE IN CIGS DIMINISHING TO AT LEAST MVFR CONDS AFT
21Z...AND MEDIUM CONFIDENCE IN CIGS BECOMING IFR AFT 3Z MON.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY...CHANCE OF SHRA/MVFR. GUSTY WEST-NORTHWESTERLY WINDS.
TUESDAY...SLGT CHANCE PM SHRA...BUT MAINLY VFR. GUSTY WEST WINDS.
WEDNESDAY...SLGT CHANCE SHRA. MAINLY VFR. WEST-NORTHWEST WINDS.
THURSDAY...VFR. NORTH-NORTHEAST WINDS.
FRIDAY...MAINLY VFR. CHC PM SHRA.
KJB
&&
.MARINE...
257 AM CDT
LOW PRESSURE OVER THE CENTRAL PLAINS WILL SLOWLY LIFT NORTHEAST
TOWARDS THE LOWER GREAT LAKES REGION TONIGHT/EARLY MON. GUIDANCE
CONTINUES TO INDICATE THE GRADIENT WILL TIGHTEN ACROSS THE
LAKE...HOWEVER THIS APPEARS TO BE MORE FOCUSED ALONG THE SOUTHERN
TIP OF THE LAKE. WITH THE CONTINUED EASTERLY WINDS...IT IS
POSSIBLE MARGINAL SMALL CRAFT CONDITIONS MAY DEVELOP FOR THE
ILLINOIS SHORELINE LATER TODAY INTO TONIGHT. THE LOW PRESSURE WILL
THEN APPROACH THE LAKE AND BRIEFLY WEAKEN THE GRADIENT EARLY MON.
THEN AS THE LOW LIFTS NORTHEAST LATER IN THE DAY MON...IT WILL
DEEPEN AND MERGE WITH ANOTHER LOW...WHICH WILL CREATE A TIGHT
GRADIENT OVER THE LAKE AND INCREASING WEST/NORTHWEST TUE. AFTER
TUE THE DOMINANT WIND DIRECTION WILL BE NORTHWEST THROUGH MID-
WEEK...BEFORE RELAXING TO THE WEST. THIS WILL ALLOW HIGHER WAVES
TO BE FOCUSED IN THE SOUTHERN HALF OF LAKE MICHIGAN THROUGH MID-
WEEK.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
344 AM CDT SUN APR 19 2015
.SHORT TERM...
340 AM CDT
THROUGH MONDAY...
UPPER AIR ANALYSIS EARLY THIS MORNING DEPICTS DEEP UPPER LEVEL LOW
PRESSURE NOW PUSHING INTO WESTERN KANSAS. MULTIPLE VORT MAXES ARE
ROTATING AROUND THE LOW. THE STRONGEST OF THESE EXIST IN TEXAS AND
THROUGH THE CENTRAL PLAINS...WITH SOME SMALLER SCALE WAVES EXTENDING
INTO EASTERN MO/FAR WESTERN IL WERE SOME SCATTERED THUNDERSTORMS
WERE ONGOING. A NORTHERN STREAM SHORTWAVE IS ENTERING THE NORTHERN
PLAINS WITH SOME SHOWERS OUT AHEAD OF IT AS WELL. AT THE
SURFACE...THE COLD FRONT THAT PASSED THROUGH NORTHEAST ILLINOIS AND
NW INDIANA SATURDAY HAS PUSHED INTO CENTRAL ILLINOIS...BUT HAS
LIKELY COMPLETED ITS SOUTHWARD RETREAT AND HAS WASHED OUT OVER THE
PAST FEW HOURS. OVER THE LOCAL AREA...MUCH DRIER NE FLOW EXISTS WITH
DEWPOINTS IN THE MID TO UPPER 20S IN THE CITY TO NEAR 40
SOUTH...THOUGH DEWPOINTS ARE POOLING ALONG THE FRONT IN THE UPPER
40S JUST SOUTH OF THE LOT CWA. THE SURFACE LOW THAT IS EXPECTED TO
DEVELOP FROM THE SOUTHERN STREAM SHORTWAVE IS ALSO TAKING SHAPE OVER
THE SOUTHERN STATES WITH A WARM FRONTAL BOUNDARY EXTENDING FROM
WESTERN ARKANSAS THROUGH THE LOWER TENNESSEE VALLEY. AN EXPANSION OF
LOWER CLOUD TOPS ON IR IMAGERY ALONG AND AHEAD OF THE WARM FRONT IS
OCCURRING.
LOW LEVEL WARM/MOIST ADVECTION WILL CONTINUE ITS SLOW PROGRESSION
NORTHWARD UNDER MODEST SOUTH/SOUTHEAST FLOW. DEEPER MOISTURE/LIFT
REALLY HOLD OFF UNTIL THE AFTERNOON PERIOD ACROSS MOST OF THE AREA.
A SOMEWHAT COMPLICATED EVOLUTION AS A MAIN SURFACE LOW CENTER IS
FORECAST TO STRENGTHEN AS IT LIFTS NORTH THROUGH INDIANA TODAY THEN
FURTHER STRENGTHEN TONIGHT INTO MONDAY WHILE SEVERAL ADDITIONAL
SURFACE LOWS DEVELOP AND EVENTUALLY MERGE WITH THE MAIN LOW CENTER.
THE SURFACE LOW WILL EVENTUALLY BECOME DRIVEN BY A COMBINATION OF
THE SW FLOW AHEAD OF THE SOUTHERN STREAM UPPER LOW AND THE
NORTHERN STREAM SHORTWAVE.
OF NOTE LATER TODAY...EXPECT COVERAGE OF SHOWERS TO INITIALLY BE
SLOW GIVEN THE DRIER AIR PLACE...BUT INCREASING ASCENT ALOFT...LOW
LEVEL SSE ISENTROPIC ASCENT AHEAD OF THE LOW AND WRAPPING AROUND THE
CLOSED CIRCULATION EXTENDING THROUGH 850 AND EVEN 700 MB COMBINED
WITH MODEST LOWER LEVEL FGEN SHOULD ALLOW FOR A BLOSSOMING OF
SHOWERS ACROSS THE AREA LATER THIS AFTERNOON AND EVENING. THE
HIGHEST PWAT AXIS EXPANDS ACROSS INDIANA TODAY BUT SHOULD GET
WRAPPED INTO NE ILLINOIS. RAP MOST UNSTABLE CAPE VALUES RELATIVELY
LOW BUT DO EXPAND FROM SE TO NW THIS AFTERNOON AND THIS COUPLED WITH
THE PUNCH FROM THE DRY SLOT OF THIS SYSTEM MAY ENABLE A FEW T-STORMS
AS WELL...SO SOME OF THE SHOWERS WILL HAVE A MODEST KICK TO THEM IN
THE MODERATE/HEAVY RAINFALL DEPARTMENT. EXPECT THAT NORTH CENTRAL
ILLINOIS MAY BE UNDER A BIT OF SQUEEZE PLAY FROM THESE TWO
SYSTEMS...THUS WHILE SHOWERS ARE STILL EXPECTED...HIGHER CONFIDENCE
EXISTS IN COVERAGE FARTHER EAST.
THIS EVENING THE FIRST MAIN SHORTWAVE WILL BE PASSING NE WHILE THE
MAIN SOUTHERN STREAM ENERGY PASSES EAST THROUGH THE OHIO
VALLEY...AND THE NORTHERN STREAM SHORTWAVE LAGS BEHIND BACK IN
MN/IA. THERE IS ALSO THE LOSS OF DEEPER MOISTURE...THEREFORE EXPECT
SHOWERS TO TAPER/END/TURN TO DRIZZLE POSSIBLY OVERNIGHT FOR A TIME.
THEN MONDAY MORNING WE GET THE COUPLED UPPER LEVEL FORCING FROM THE
NORTHERN STREAM LOW AND SURFACE COLD FRONT WHICH WILL LIKELY BRING
ANOTHER ROUND OF SHOWERS MONDAY MORNING. SHOWERS WILL EASE MONDAY
AFTERNOON. IT WILL BE QUITE BREEZY/WINDY BEHIND THE FRONT ON MONDAY
IN THE COLD ADVECTION REGIME.
KMD
&&
.LONG TERM...
340 AM CDT
MONDAY NIGHT THROUGH SATURDAY...
THE THEME OF THE EXTENDED WILL BE THE UNSEASONABLY COOL WEATHER. A
HIGH AMPLITUDE PATTERN WILL BE IN PLACE WITH STRONG UPPER LEVEL
RIDGING EXTENDING WELL NORTH INTO THE CANADIAN ROCKIES AND SIMILARLY
HIGH AMPLITUDE RIDGING IN THE NORTH ATLANTIC. THAT LEAVES OUR
NORTHERN STREAM SHORTWAVE FROM SUNDAY/MONDAY WITH NO WHERE TO GO.
THIS WILL KEEP MUCH OF THE EASTERN HALF OF THE COUNTY...INCLUDING
OUR REGION...UNDER COOL NORTHWEST FLOW. THIS PATTERN ALSO FAVORED
STRONGLY SHEARED OUT AND ELONGATED VORT MAXES TO PIVOT THROUGH
BRINGING PERIODS OF SHOWERS. WITH PWAT VALUES QUITE LOW IN THIS
AIRMASS...MUCH OF THE PERIOD WILL BE DRY AND EVEN THE SHOWERS SHOULD
NOT BE VERY STRONG. BUT MORE IMPORTANTLY...SEASONAL AVERAGE
HIGHS/LOWS FOR LATE APRIL ARE THE LOWER 60S (MID 60S SOUTH) AND
LOWER 40S RESPECTIVELY...AND MUCH OF THIS PERIOD WILL FEATURE HIGHS
IN THE 50S AND LOWS IN THE MID 30S...POSSIBLY COOLER A NIGHT OR TWO
IF WINDS ARE LIGHTER. TEMPERATURE ANOMALIES ARE NOT THAT EXTREME
THOUGH...SO RECORD COLD IS NOT ANTICIPATED.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* EAST WINDS ARND 6 TO 10 KT...OCCASIONAL GUSTS TO 17KT.
* WINDS TURN NORTH LATE TONIGHT...THEN NORTHWEST EARLY MON.
* RAIN OVERSPREAD TAF SITES LATE THIS AFTN THRU TONIGHT.
* POSSIBLE LOW END MVFR CIGS OR PATCHY IFR CIGS DEVELOPING.
BEACHLER
//DISCUSSION...UPDATED 06Z...
WITH THE DEPARTING HIGH PRESSURE TO THE EAST...MID-LVL MOISTURE
WAS SLOWLY LIFTING NORTH ACROSS THE NORTHERN IL/NORTHWEST IN
AIRFIELDS. THIS HAS ALLOWED A CIRRUS CLOUD DECK TO THICKEN...AND
ADDITIONAL MOISTURE IS EXPECTED TO LIFT NORTHEAST AS A LOW
PRESSURE SYSTEM NEARS THE REGION LATER TONIGHT INTO EARLY MON.
GUIDANCE HAS BEEN SLOWLY TRENDING LATER WITH THE ARRIVAL OF PRECIP
UNTIL AFT 18Z...AND MAY NOT BE CLOSER TO 23Z. WILL CONTINUE TO
MENTION VCSH BUT PUSH IT TO 20Z...THEN EXPECT THE COVERAGE TO
INCREASE IN PRECIP CLOSER TO 23Z. WITH THE STEADILY THICKEN AND
LOWER CLOUDS...THE CHALLENGE IS ALSO ON WIND SPEEDS. IT IS STILL
POSSIBLE GUSTS WILL NEED TO BE PUT BACK INTO THE TAF...ALTHOUGH
WITH THE ABUNDANT CLOUD COVER...IT IS QUESTIONABLE HOW FREQUENT
GUSTS WILL OCCUR AT THE TAF SITES. SO HAVE REMOVED THE MENTION AT
THIS TIME AND JUST INCREASED THE SUSTAINED WINDS. THEN AT SOME
POINT LATE THIS EVENING CIGS ARE EXPECTED TO QUICKLY DIP TO MVFR
AND POSSIBLY TO IFR CONDS. PRECIP COVERAGE WILL BEGIN TO DIMINISH
EARLY MON...AND MAY TREND TOWARDS PATCHY DRIZZLE WHICH MAY ALSO
FURTHER LOWER CIGS AND VSBYS EARLY MON MORNING.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE IN ALL ELEMENTS THROUGH 18Z...MEDIUM CONFIDENCE
IN WIND DIR/SPEED AFT 18Z.
* MEDIUM CONFIDENCE IN PRECIP TIMING/COVERAGE.
* HIGH CONFIDENCE IN CIGS DIMINISHING TO AT LEAST MVFR CONDS AFT
21Z...AND MEDIUM CONFIDENCE IN CIGS BECOMING IFR AFT 3Z MON.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY...CHANCE OF SHRA/MVFR. GUSTY WEST-NORTHWESTERLY WINDS.
TUESDAY...SLGT CHANCE PM SHRA...BUT MAINLY VFR. GUSTY WEST WINDS.
WEDNESDAY...SLGT CHANCE SHRA. MAINLY VFR. WEST-NORTHWEST WINDS.
THURSDAY...VFR. NORTH-NORTHEAST WINDS.
FRIDAY...MAINLY VFR. CHC PM SHRA.
KJB
&&
.MARINE...
257 AM CDT
LOW PRESSURE OVER THE CENTRAL PLAINS WILL SLOWLY LIFT NORTHEAST
TOWARDS THE LOWER GREAT LAKES REGION TONIGHT/EARLY MON. GUIDANCE
CONTINUES TO INDICATE THE GRADIENT WILL TIGHTEN ACROSS THE
LAKE...HOWEVER THIS APPEARS TO BE MORE FOCUSED ALONG THE SOUTHERN
TIP OF THE LAKE. WITH THE CONTINUED EASTERLY WINDS...IT IS
POSSIBLE MARGINAL SMALL CRAFT CONDITIONS MAY DEVELOP FOR THE
ILLINOIS SHORELINE LATER TODAY INTO TONIGHT. THE LOW PRESSURE WILL
THEN APPROACH THE LAKE AND BRIEFLY WEAKEN THE GRADIENT EARLY MON.
THEN AS THE LOW LIFTS NORTHEAST LATER IN THE DAY MON...IT WILL
DEEPEN AND MERGE WITH ANOTHER LOW...WHICH WILL CREATE A TIGHT
GRADIENT OVER THE LAKE AND INCREASING WEST/NORTHWEST TUE. AFTER
TUE THE DOMINANT WIND DIRECTION WILL BE NORTHWEST THROUGH MID-
WEEK...BEFORE RELAXING TO THE WEST. THIS WILL ALLOW HIGHER WAVES
TO BE FOCUSED IN THE SOUTHERN HALF OF LAKE MICHIGAN THROUGH MID-
WEEK.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS LINCOLN IL
328 AM CDT SUN APR 19 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 328 AM CDT SUN APR 19 2015
LATEST WATER VAPOR IMAGERY CONTINUES TO SHOW CLOSED UPPER LOW OVER
EASTERN COLORADO, WITH LEAD SHORT-WAVE ROTATING AROUND THIS FEATURE
ACROSS ARKANSAS/LOUISIANA. AS THIS WAVE LIFTS NORTHWARD, PRECIP
WILL EVENTUALLY SPREAD INTO CENTRAL ILLINOIS TODAY. 07Z/2AM RADAR
MOSAIC SHOWS DRY CONDITIONS ACROSS THE ENTIRE KILX CWA: HOWEVER,
SHOWERS ARE BEGINNING TO DEVELOP AND BECOME MORE WIDESPREAD FURTHER
SOUTH ACROSS WESTERN KENTUCKY AND FAR SOUTHERN ILLINOIS. BASED ON
RADAR TIMING TOOLS AND LATEST HRRR FORECAST, THINK SCATTERED SHOWERS
WILL ARRIVE SOUTH OF I-70 OVER THE NEXT COUPLE OF HOURS, THEN WILL
SPREAD NORTHWARD TOWARD THE I-74 CORRIDOR BY MIDDAY. HAVE ADJUSTED
POPS TO ACCOUNT FOR THE SLOWER ARRIVAL OF PRECIP DURING THE MORNING,
THEN HAVE GONE WITH CATEGORICAL POPS ACROSS THE BOARD THIS
AFTERNOON. ASIDE FROM SOME SBCAPES OF AROUND 1000J/KG ACROSS THE
FAR SE CWA, FORECAST SOUNDINGS REMAIN FAIRLY STABLE TODAY. AS A
RESULT, AM EXPECTING MAINLY SHOWERS WITH JUST A FEW EMBEDDED
THUNDERSTORMS. DUE TO CLOUD COVER AND PRECIP, HIGH TEMPERATURES
WILL BE SEVERAL DEGREES COOLER THAN IN RECENT DAYS, WITH READINGS
MAINLY IN THE 60S. WARMEST TEMPS OF AROUND 70 WILL BE FOCUSED
ALONG/WEST OF THE ILLINOIS RIVER WHERE PRECIP WILL BE SLOWEST TO
ARRIVE.
&&
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 328 AM CDT SUN APR 19 2015
LEAD SHORT-WAVE WILL LIFT INTO NORTHERN ILLINOIS/INDIANA BY EARLY
EVENING, LIKELY LEADING TO A TEMPORARY LULL IN THE SHOWERS.
MEANWHILE, THE MAIN UPPER LOW WILL GET A SOLID PUSH EASTWARD AND
WILL ARRIVE ACROSS ILLINOIS LATER TONIGHT INTO MONDAY MORNING.
SHOWERS AND PERHAPS A THUNDERSTORM WILL ACCOMPANY THIS FEATURE, SO
WILL CONTINUE LIKELY POPS TONIGHT THROUGH MONDAY MORNING. ONCE THE
500MB VORT MAX AND THE ASSOCIATED SURFACE COLD FRONT PASS TO THE
EAST, RAIN CHANCES WILL COME TO AN END BY MONDAY AFTERNOON. THANKS
TO A TIGHT PRESSURE GRADIENT BEHIND THE DEPARTING FRONT, STRONG W/NW
WINDS GUSTING TO BETWEEN 25 AND 30 MPH WILL DEVELOP ON MONDAY. THE
WINDS WILL SUBSIDE FOR A TIME MONDAY NIGHT, BUT WILL ONCE AGAIN
INCREASE MARKEDLY DURING THE DAY TUESDAY. HIGH TEMPERATURES BOTH
DAYS WILL REMAIN IN THE LOWER 60S, WHILE OVERNIGHT LOWS DIP INTO THE
UPPER 30S AND LOWER 40S.
00Z APR 19 MODELS HAVE COME INTO MUCH BETTER AGREEMENT CONCERNING
THE EXTENDED FORECAST, WITH CONSENSUS FEATURING A CHILLY AND LARGELY
DRY WEEK AHEAD. BOTH THE GFS AND ECMWF INDICATE A WEAK COLD FRONT
WILL PASS THROUGH CENTRAL ILLINOIS TUESDAY NIGHT INTO WEDNESDAY:
HOWEVER, THEY DISAGREE ON HOW MUCH PRECIP IT WILL GENERATE. THE GFS
IS SLIGHTLY WETTER AND FASTER WITH FROPA, WHILE THE ECMWF IS DRIER
AND ABOUT 6 HOURS SLOWER WITH THE FRONT. DUE TO THE STRONG
NORTHWESTERLY UPPER FLOW PATTERN IN PLACE ACROSS THE MIDWEST, THINK
THE FASTER GFS IS THE WAY TO GO WITH TIMING, BUT THINK THE DRIER
ECMWF IS BETTER WITH QPF AS DEEP MOISTURE WILL BE LACKING WITH THIS
FEATURE. AS A RESULT, HAVE OPTED TO CARRY LOW CHANCE POPS
EVERYWHERE TUESDAY NIGHT, THEN ONLY ACROSS THE SE CWA ON WEDNESDAY.
ONCE THE FRONT PASSES, A COOL/CANADIAN AIRMASS WILL SETTLE INTO THE
REGION FOR THE MIDDLE AND END OF THE WEEK. HIGH TEMPERATURES WILL
STRUGGLE TO REACH THE 60 DEGREE MARK ON BOTH WEDNESDAY AND THURSDAY,
WHILE LOWS DROP INTO THE 30S. COLDEST MORNING MAY END UP BEING
FRIDAY MORNING, WHEN RIDGE OF HIGH PRESSURE IS OVERHEAD AND WINDS
WILL BE LIGHTEST. WILL NEED TO KEEP AN EYE ON TEMPS, AS FROST
ADVISORIES WILL BE POSSIBLE ACROSS PARTS OF CENTRAL/SOUTHEAST
ILLINOIS LATER THIS WEEK. AFTER THAT, ANOTHER SYSTEM WILL APPROACH
FROM THE SOUTHWEST BY THE END OF THE WEEK: HOWEVER, ITS INFLUENCE
LIKELY WILL NOT BE FELT UNTIL FRIDAY NIGHT/SATURDAY AT THE EARLIEST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1145 PM CDT SAT APR 18 2015
VFR CONDITIONS CONTINUE ACROSS CENTRAL IL TAF SITES THIS EVENING
AS A COMPLEX PATTERN OF A LARGE SCALE CENTRAL U.S. TROUGH WITH
MULTIPLE EMBEDDED DISTURBANCES DEVELOPS. MAINLY VFR CONDITIONS
EXPECTED UNTIL AROUND 12Z WHEN THE FIRST EMBEDDED DISTURBANCE
LIFTS NORTHEASTWARD INTO SE ILLINOIS. EXPECT INCREASING
PRECIPITATION AT SOUTHERN TERMINALS KSPI-KDEC AROUND 10Z SPREADING
NORTH TO KPIA-KBMI-KCMI AROUND 12Z. BY 14-16Z...PREDOMINANT RAIN
WITH MVFR CIGS/VSBYS LIKELY AND INCLUDED IN TAFS. ISOLATED
THUNDERSTORMS POSSIBLE AS WELL...BUT LIKELIHOOD/TIMING NOT HIGH
ENOUGH FOR EXPLICIT MENTION THIS FAR OUT. BRIEFLY IMPROVING
CONDITIONS LATE AFTERNOON EARLY EVENING AS FIRST DISTURBANCE MOVES
OUT OF CENTRAL IL...BUT TRAILING WAVE/COLD FRONT EXPECTED TO
INITIATE ADDITIONAL SHOWERS/THUNDERSTORMS TOWARD 06Z. WITH A
NARROW WINDOW OF UNCERTAIN IMPROVEMENT...KEPT MVFR CIGS/VSBYS
THROUGH 06Z. WINDS E-NE5-10 KTS THROUGH 15Z BECOMING VARIABLE-
NNW DURING AFTERNOON AS LOW LIFTS TO THE NE OF CENTRAL IL AREA.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...ONTON
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
733 AM CDT SUN APR 19 2015
.UPDATE...
ISSUED AT 730 AM CDT SUN APR 19 2015
SCATTERED SHOWERS CONTINUE TO DEVELOP AND MOVE GENERALLY IN A NORTHWARD
DIRECTION...AND WERE MAINLY WEST OF A MACOMB IL TO MANCHESTER IA LINE.
THESE SHOWERS WERE OCCURRING IN THE AXIS OF THE BETTER 850 MB MOISTURE
TRANSPORT AND PRECIPITABLE WATERS OVER AN INCH.
ELSEWHERE...LOW PRESSURE WAS ORGANIZING IN THE LOWER MS VALLEY AND
A BROAD AREA OF PRESSURE FALLS WAS NOTED TO THE NORTH INDICATING LARGE
SCALE ASCENT/WARM AIR ADVECTION WAS INCREASING. ALSO PRESSURE FALLS
WERE OCCURRING IN THE UPPER MS VALLEY IN ASSOCIATION WITH THE DIGGING
NORTHERN STREAM TROUGH. REGIONAL DOPPLER RADARS WERE SHOWING THE LEADING
EDGE OF A RATHER LARGE AREA OF RAIN/ISOLATED THUNDERSTORMS FROM THE
MO OZARKS AND SOUTHERN IL...MOVING NORTHWARD.
THE HRRR MESO MODEL HAS CAPTURED THIS RAIN AREA WITH THE LEADING
EDGE REACHING MACOMB BY NOON...THE QUAD CITIES BY EARLY AFTERNOON
AND DUBUQUE/FREEPORT BY LATE AFTERNOON. THEREFORE...WIDESPREAD
RAIN APPEARS LIKELY THIS AFTERNOON AND CONTINUING TONIGHT...WHICH
THE CURRENT GRIDS DEPICT.
&&
.SYNOPSIS...
ISSUED AT 345 AM CDT SUN APR 19 2015
MODELS CONTINUE TO STRUGGLE WITH THE EASTERLY FEED OF DRY AIR INTO
OUR NORTHEAST CWA AND AT SOME LOCATIONS DEWPOINTS WERE 10 DEGREES
LOWER THAN ANY GUIDANCE. IN OUR WESTERN CWA GUIDANCE WAS CLOSE TO
REALITY AS WINDS WERE MORE SOUTHEAST. SPC MESO ANALYSIS SHOWED
DECENT 850 MB MOISTURE TRANSPORT ALONG WITH PRECIPITABLE WATERS
OVER AN INCH IN OUR WESTERN CWA. AND SURE ENOUGH DOPPLER RADAR HAS
SHOWN POCKETS OF SHOWERS AND ISOLATED THUNDERSTORMS ALL NIGHT.
RAINFALL ESTIMATES INDICATE 1/4 TO 3/4 OF AN INCH HAS FALLEN IN
SOME SPOTS IN OUR WEST SINCE LAST EVENING.
3 AM TEMPERATURES RANGED FROM 50 AT FREEPORT TO 61 AT MACOMB.
ELSEWHERE...CANADIAN HIGH PRESSURE WAS CENTERED NORTHEAST OF LAKE
SUPERIOR AND SOME SITES IN NW WI WERE REPORTING DEWPOINTS IN THE TEENS.
UPPER LEVEL TROUGH WAS DIGGING INTO THE NORTHERN PLAINS WHILE
ANOTHER TROUGH WAS PUSHING INTO THE CENTRAL/SOUTHERN PLAINS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM CDT SUN APR 19 2015
FORECAST FOCUS ON INCREASING RAIN AND TEMPERATURES.
TODAY...UPPER LEVEL TROUGH APPROACHES FROM THE WEST AND THIS WILL PROVIDE
LARGE SCALE ASCENT ALONG WITH BETTER MOISTURE TRANSPORT AS THE DAY PROGRESSES.
THE MORE WIDESPREAD RAIN APPEARS TO DEVELOP THIS AFTERNOON WITH THE
ARRIVAL OF STRONGER FORCING...AS A SHORT WAVE PUSHES ACROSS IA AHEAD
OF THE MAIN TROUGH. MEANWHILE...PHASING BEGINS TO OCCUR AND MODELS LIFT
A DEEPENING CYCLONE OUT OF THE LOWER MS VALLEY INTO FAR WESTERN INDIANA
BY 00Z. INTERESTING THAT THE NAM/ECMWF KEEP NW IL DRY MUCH OF THE DAY
AND THEY MAY BE ON TO SOMETHING WITH SUCH A DRY EASTERLY FEED INTO THAT
AREA. I WILL MENTION ISOLATED THUNDERSTORMS THIS AFTERNOON AS DEEP LAYER
SHEAR IS WEAK AND MUCAPE IS 500 J/KG OR LESS. WITH MORE CLOUDINESS TODAY
MAXIMUM TEMPERATURES SHOULD BE COOLER THAN THAN THE PAST COUPLE OF DAYS.
I AM EXPECTING HIGHS IN THE UPPER 60S TO LOWER 70S AT MOST LOCATIONS.
TONIGHT...PHASING IS NEARLY COMPLETE AND A LONG WAVE TROUGH PUSHES
ACROSS THE MIDWEST WITH DECENT FORCING AND GOOD MOISTURE IN PLACE.
IN THE MEANTIME...THE SLOWLY DEEPENING CYCLONE LIFTS INTO NORTHERN
LOWER MI BY 12Z. MODELS INDICATE WIDESPREAD RAIN OVER THE CWA MUCH
OF THE NIGHT. THIS LOOKS TO BE MORE OF A STRATIFORM/DEFORMATION TYPE
RAIN RATHER THAN ALL OUT CONVECTIVE/MCS TYPE SO WILL NOT MENTION THUNDER
AS INSTABILITY IS VERY LIMITED...AND THE ENTIRE COLUMN IS VERY SATURATED.
A COLD FRONT WILL PUSH ACROSS THE CWA DURING THE NIGHT USHERING MUCH
COOLER TEMPERATURES INTO THE AREA BY MORNING. MINIMUM TEMPERATURES
WILL RANGE FROM THE LOWER 40S AT INDEPENDENCE TO THE UPPER 40S AT
PRINCETON AND MACOMB IN ILLINOIS.
RAINFALL AMOUNTS TODAY THROUGH TONIGHT SHOULD BE 0.3 TO 0.7 INCHES OVER
MUCH OF THE CWA.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 345 AM CDT SUN APR 19 2015
COOLER AND MAINLY DRY FOR MUCH OF UPCOMING WEEK WITH FROST/FREEZE
POTENTIAL LATER IN THE WEEK.
MUCH OF THE UPCOMING WEEK AHEAD WILL FEATURE A LARGE AND SLOW
MOVING UPPER LOW FROM THE GREAT LAKES TO EASTERN CANADA DUE TO
HIGHLY AMPLIFIED RIDGING OVER THE EASTERN ATLANTIC AND GREENLAND.
OUR CWA WILL BE GOVERNED BY NORTHWEST FLOW ON BACKSIDE OF THE
LARGE UPPER LOW WHICH WILL USHER IN REINFORCING BOUTS OF CANADIAN
AIR RESULTING IN COOLER HIGHS IN THE 50S AND 60S... WITH LOWS
MAINLY IN THE 30S. THE COOLER AIR WILL ALSO BE ACCOMPANIED BY
WINDY CONDITIONS MONDAY AND TUESDAY WITH THE POTENTIAL TO BE
NEAR WIND ADVISORY CRITERIA GIVEN JUXTAPOSITION OF TIGHT PRESSURE
GRADIENT... COLD ADVECTION AND DEEP MIXING. AFTER SOME LINGERING
SHOWERS POSSIBLE EARLY MONDAY AM... WILL HAVE THE POTENTIAL
FOR AFTERNOON POPCORN SHOWERS ACROSS MAINLY THE NORTHERN CWA BOTH
MONDAY AND TUESDAY WITH STEEP MID LEVEL LAPSE RATES... COLD
AIR ALOFT... AND SKINNY CAPE NOTED ON FORECAST SOUNDINGS. WILL
NEED TO WATCH FOR ENHANCED WIND GUSTS WITH ANY SHOWERS VIA
EVAPORATIVE COOLING OF PCPN IN LARGE... DRY SUB-CLOUD LAYER WITH
CLASSIC INVERTED V SOUNDINGS.
CANADIAN SURFACE RIDGE AXIS BUILDING IN THURSDAY INTO FRIDAY WILL
BRING POTENTIAL FOR FROST AND POSSIBLY FREEZING TEMPS ONE OR BOTH
MORNINGS. MIN TEMPS MAY NEED LOWERING BY 3-5 DEGS SOME LOCATIONS
ESPECIALLY THURSDAY AM BASED ON 850 MB TEMPS -4C TO -7C WITH MORE
WIDESPREAD 20S POSSIBLE WITH ANY DURATION OF CLEAR SKIES AND LIGHT
WINDS.
RAIN CHANCES LOOK TO RETURN BY EITHER LATE IN THE WEEK AND/OR NEXT
WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 730 AM CDT SUN APR 19 2015
VFR CONDS BECOMING MVFR/LCL IFR CONDS. SCATTERED SHOWERS IN EASTERN
IA THIS MORNING WILL EXPAND IN COVERAGE AND THE RAIN WILL BE WIDESPREAD
THIS AFTERNOON AND TONIGHT. ISOLATED THUNDERSTORMS ARE ALSO POSSIBLE...MAINLY
THIS AFTERNOON. A COLD FRONT WILL ALSO ARRIVE TONIGHT. EAST TO SOUTHEAST
WINDS LESS THAN 10 KNOTS TODAY THEN BECOMING NORTHWEST 15 TO 25 KNOTS
BEHIND THE COLD FRONT TONIGHT.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...HAASE
SYNOPSIS...HAASE
SHORT TERM...HAASE
LONG TERM...MCCLURE
AVIATION...HAASE
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1205 AM CDT SUN APR 19 2015
.DISCUSSION...
FOR THE 06Z TAF PACKAGE.
&&
.AVIATION...
AS ANTICIPATED...VISIBILITY RESTRICTIONS HAVE BEGUN TO DEVELOP
ACROSS THE AREA...AND CONVECTIVE COMPLEX APPROACHING FROM THE
NORTHWEST IS STARTING TO DECAY. TIMED THE REMNANTS OF THIS FEATURE
INTO KBPT...KLCH...AND KAEX AS JUST A BRIEF PERIOD OF INCREASED
WINDS AND LIGHT RAIN. NO EFFECTS CARRIED AT THE ACADIANA
TERMINALS. EXPECT THAT THE RESULTANT MIXING WILL IMPROVE THE
VISIBILITY...AT LEAST TEMPORARILY...BUT DID SHOW THE FOG RE-
DEVELOPING A COUPLE HOURS LATER. VFR TO PREVAIL TOMORROW ONCE THE
FOG ERODES.
13
&&
.PREV DISCUSSION... /ISSUED 925 PM CDT SAT APR 18 2015/
DISCUSSION...
MAIN WX CONCERN IS THE MCS OVER C AND N TX...MOVING E. RADAR STILL
SHOWS FAIRLY SOLID SQUALL LINE BETWEEN WHILE SOME WEAKENING IS
EXPECTED TO CONTINUE...LATEST NAM12 & HRRR SUGGEST IT CONTINUING E
THE NEXT SEVERAL HOURS...AFFECTING INLAND SE TX/C LA BETWEEN
06-09Z. THUS...HAVE INCREASED THE POPS AND QPF ACROSS THESE AREAS
FOR THE EVENING UPDATE. FOR THE REMAINDER OF THE AREA...20%
CONTINUES FOR ANY ISO SHRA/TSRA AHEAD OF THIS SYSTEM.
DML
PREV DISCUSSION... /ISSUED 734 PM CDT SAT APR 18 2015/
DISCUSSION...
FOR THE 00Z TAF PACKAGE.
AVIATION...
MAINLY ISOLATED TO SCATTERED SHOWERS ACROSS PARTS OF EAST AND
SOUTH CENTRAL LOUISIANA EARLY THIS EVENING. LATEST HRRR DEPICTS
CONVECTIVE COMPLEX OVER CENTRAL TEXAS REACHING PERHAPS AS FAR AS JUST
EAST OF THE SABINE RIVER SOMETIME AFTER MIDNIGHT BEFORE
DISSIPATING. WILL CONTINUE TO MONITOR RADAR/MODEL TRENDS THROUGH
THE EVENING. OTHERWISE...A MIX OF MVFR/VFR CIGS ACROSS THE AREA IS
EXPECTED TO LOWER INTO MVFR/IFR AS LIGHT FOG AND/OR LOWER CIGS
DEVELOP DURING THE OVERNIGHT HOURS. IMPROVEMENT TO VFR IS EXPECTED
ON SUNDAY AS DRIER AIR MOVES IN FROM THE WEST.
13
PREV DISCUSSION... /ISSUED 421 PM CDT SAT APR 18 2015/
SYNOPSIS...
LATEST UA ANALYSIS AND WV IMAGERY SHOWS SLOW-MOVING UPR LOW OVER
ERN COLORADO...WITH MOIST SWLY FLOW CONTINUING TO STREAM OVER THE
REGION. ONE IMPULSE ASSOCIATED WITH THIS SYSTEM WAS MOVING ACRS
SRN TX INTO THE WRN GULF...WITH A SECOND IMPULSE CROSSING WRN TX.
THESE TWO SYSTEMS WERE TRIGGERING STORMS ACRS THE NW/CNTL GULF
COAST AS WELL AS ACRS WRN TX. OVER THE IMMEDIATE CWA...ACTIVITY
HAS REMAINED FAIRLY SCTD...WITH A SWATH OF LT/MODT RAIN OVER THE
COASTAL WATERS...AND SCT SHRA/TSRA ACRS CNTL/WRN LA.
DISCUSSION...
OVERNIGHT CONVECTIVE COMPLEX ALLOWED THE AIRMASS TO STABILIZE
TODAY...AND ONGOING CONVECTION OVER THE GULF HAS LIMITED INFLOW.
THIS COMBINATION HAS REDUCED THE POTENTIAL FOR HEAVY RAIN AND
WIDESPREAD ACTIVITY TODAY AND LIKELY INTO TONIGHT. LOOKING AT A
COMBINATION OF RECENT HRRR RUNS AS WELL AS RAP/NAM GUIDANCE SHOWS
A DECREASING TREND DURING THE EVENING AND OVERNIGHT. ACTIVITY
ALONG THE TX COAST IS EXPECTED TO TREK E/NE BUT GRADUALLY WEAKEN
AS IT APPROACHES OUR COASTAL WATERS ZONES. LIKEWISE...THE STORMS
ACRS WRN TX WILL MOVE EAST THIS EVENING...BUT ALSO WEAKEN AS THEY
REACH THE AREA LATER TONIGHT. QPF VALUES ARE EXPECTED TO REMAIN
BELOW AN INCH THROUGH SUNDAY...AND WITH THIS IN MIND...HAVE GONE
AHEAD AND CANCELLED THE FLASH FLOOD WATCH.
DRIER MID LVL AIR WILL BEGIN TO PUSH EAST OVER THE AREA ON
SUNDAY...HELPING TO BRING A REPREIVE FROM THE RAINY PATTERN.
HOWEVER...ENOUGH MOISTURE WILL LINGER TO ALLOW FOR AT LEAST A SLT
CHC FOR A FEW SHOWERS OR TSTMS. BY SUNDAY NIGHT...A COOL FRONT
WILL MOVE THROUGH THE REGION. ENOUGH CONVERGENCE AND LIFT ARE
EXPECTED ALONG THE FRONTAL BOUNDARY TO PRODUCE A SCT BAND OF
SHOWERS AND TSTMS AS IT CROSSES THE AREA. SPC DOES HAVE THE AREA
OUTLINED IN A SLT RISK FOR SUNDAY/SUNDAY NIGHT AS INSTABILITY
LOOKS TO INCREASE AHEAD OF THE BOUNDARY. THUS AN ISOLATED STRONG
TO SEVERE STORM CANNOT BE RULED OUT ESPECIALLY ACRS THE NRN TIER
OF COUNTIES AND PARISHES.
DRY WEATHER FINALLY RETURNS ON MONDAY AND SHOULD CONTINUE INTO
TUESDAY AS HIGH PRES BUILDS INTO THE AREA. SMALL RAIN CHCS WILL
RETURN BY MIDWEEK WITH CHCS INCREASING TOWARD THE LATTER PART OF
THE WEEK. ZONAL FLOW WILL PREVAIL THROUGH THE WEEK AND LIFT
ASSOCIATED WITH EMBEDDED DISTURBANCES WILL KEEP AT LEAST CHC POPS
OVER THE AREA THURSDAY AND FRIDAY.
MARINE...
LT TO MDT SWLY FLOW WILL CONTINUE THROUGH SUNDAY WITH SHOWERS AND
TSTMS GRADUALLY DIMINISHING. A COOL FRONT WILL CROSS THE COASTAL
WATERS LATE SUNDAY NIGHT...WITH MODT OFFSHORE FLOW DEVELOPING
FOR MONDAY. EXERCISE CAUTION CONDITIONS COULD BE POSSIBLE AT TIMES
MONDAY INTO TUESDAY. WINDS WILL GRADUALLY VEER ELY TUESDAY...THEN
SELY BY WEDNESDAY AS SFC HIGH PRES MOVES EAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 63 83 60 76 / 30 30 30 10
LCH 64 82 63 79 / 20 20 20 10
LFT 65 84 64 79 / 30 20 20 10
BPT 64 82 63 79 / 20 20 20 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAY ME
1033 PM EDT MON APR 20 2015
.SYNOPSIS...
LOW PRESSURE MEANDERING NORTH OF THE GREAT LAKES WILL DRIVE A COLD
FRONT TOWARD THE REGION TONIGHT. THE FRONT WILL SLOWLY CROSS THE
REGION ON TUESDAY. LOW PRESSURE NORTH OF THE GREAT LAKES WILL
GRADUALLY WEAKEN AS IT DRIFTS SOUTHEAST INTO NEW ENGLAND WEDNESDAY
THROUGH THURSDAY. LOW PRESSURE WILL CONTINUE TO WEAKEN AS IT
MEANDERS NORTH OF NEW ENGLAND FRIDAY THROUGH SATURDAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
UPDATE...THE HIGHEST THREAT FOR STRONG WIND GUSTS IS COMING TO AN
END...SO WILL TAKE DOWN THE WIND ADVISORY. OTHERWISE NO MAJOR
CHANGES TO THE FORECAST. MESOSCALE MODELS STILL FAVOR THE IDEA OF
A COMPLEX OF TSTMS CROSSING THE FORECAST AREA DURING THE MORNING.
SO NO CHANGES THERE EITHER.
HAVE MODIFIED THE GRIDS THRU MORNING BASED ON LATEST HI-RES MODEL
GUIDANCE. EXAMINING RECENT HRRR RUNS HAVE A LARGE AREA FAVORABLE
FOR LIGHTNING DEVELOPMENT MOVING ACROSS THE REGION ON THE LEADING
EDGE OF THE DRY SLOT NEAR MORNING. IN ADDITION...THE SPC SSEO
PRODUCTS ALSO FAVOR A CLUSTER OR LINE OF TSTMS CROSSING THE
FORECAST AREA NEAR 12Z. HAVE INCREASED THE PROBABILITY FOR THUNDER
LATE TONIGHT AND EARLY TUE AS A RESULT.
HAVE ALSO INTRODUCED SOME AREAS OF HEAVY RA TO THE GRIDS NEAR THE
COASTAL FRONT AS WELL AS IN THE EAST SLOPES OF THE MTNS WHERE
STRONG SELY LLJ WILL IMPINGE UPON THE TERRAIN.
THIS LLJ...WHICH IS REALLY JUST GETTING UNDERWAY OVER SRN NEW
ENGLAND PER KBOX 88D...WILL SLOWLY TRAVERSE THE COAST THRU ABOUT
06Z. THIS PUTS HEAVIEST PRECIP IN THE FORECAST AREA BETWEEN ABOUT
00Z AND 06Z. IN ADDITION TO THE HEAVY PRECIP...THIS LLJ MAY INDUCE
SOME STRONG DOWNSLOPE WIND GUSTS NW OF THE WHITE MTNS.
PREVIOUS DISCUSSION...THE FIRST BATCH OF RAIN FROM THIS MORNING
WAS MOVING INTO EASTERN MAINE AS A WARM FRONT LIFTED NORTH INTO
SOUTHERN CANADA. SO FAR ONLY A TENTH TO ABOUT A THIRD OF AN INCH
OF RAIN HAS FALLEN TODAY WITH SOME ISOLATED HIGHER AMOUNTS. THIS
MORNINGS GYX SOUNDING HAD PLENTY OF DRY AIR AND THIS INHIBITED
RAINFALL FROM SPREADING FASTER FOR THE FIRST HALF OF THE DAY.
STEADIER RAINS ARE NOW OVER SOUTHERN NH AND MOVING INTO WESTERN
MAINE. THIS TREND WILL CONTINUE INTO THE EVENING HOURS.
A SECONDARY CYCLONE WILL FORM TONIGHT OVER THE VIRGINIAS AND MOVE
NE ALONG THE ATLANTIC COAST. AS IT DEEPENS IN THE GULF OF MAINE A
LLJ WILL STRENGTHEN AND FEED MOISTURE RICH AIR INTO COASTAL NH AND
MAINE. WARM RAIN PROCESSES AND TRAINING OF CELLS WILL SUPPORT HEAVY
RAIN OVERNIGHT AND INTO TUESDAY. A FLOOD WATCH REMAINS IN EFFECT AS
RAIN COMBINES WITH SNOWMELT TO BRING RIVERS AND STREAMS TO NEAR
BANKFULL.
WINDS WILL BE GUSTY... ESPECIALLY ALONG THE COAST... BUT WE
SHOULD FALL SHORT OF WIND ADVISORY CRITERIA. COASTAL FLOODING WILL
ALSO BE A CONCERN FROM PORTLAND WESTWARD AS EASTERLY FLOW
INCREASES AND COINCIDES WITH THE ASTRONOMICAL HIGH TIDE. MORE
INFORMATION ON THESE HAZARDS BELOW.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
MODERATE TO HEAVY RAIN CONTINUES INTO TUESDAY MORNING. MUCAPE
VALUES INDICATE A SLIGHT CHANCE FOR THUNDERSTORMS BETWEEN 12-18Z
TOMORROW AS THE COLD CORE OF THE UPPER LOW SWINGS BY OVERHEAD.
DRIER AIR PUNCHES IN FROM THE SW MIDDAY TUESDAY. SOME LINGERING
SHOWERS WILL BE POSSIBLE OVER THE MOUNTAINS IN UPSLOPE FLOW. HIGHS
SHOULD WARM INTO THE UPPER 40S NORTH TO LOWER 60S SOUTH.
ADDITIONAL SHOWERS WILL BE POSSIBLE TUESDAY NIGHT WITH CYCLONIC
FLOW ALOFT.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
BROAD UPPER LEVEL CLOSED LOW WILL KEEP WEATHER UNSETTLED
IN THE NORTHEAST THROUGH THE WEEK AND INTO THE WEEKEND AS
IT GRADUALLY SHIFTS EAST. EXPECT SEVERAL LOBES OF ENERGY
TO ROTATE AROUND THIS SYSTEM AND INTO THE NORTHEAST. ANY
MORNING SUN ON WEDNESDAY WILL QUICKLY GIVE WAY TO CLOUDS
AND SHOWERS AS THE FIRST OF THESE DISTURBANCES SWINGS INTO
THE REGION. EXPECT THESE SHOWERS TO PERSIST INTO WEDNESDAY
NIGHT AS A WEAK SURFACE LOW SLOWLY CROSSES THE REGION.
STEADIER PRECIP WILL COME TO AN END AS LOW PRESSURE LIFTS INTO
THE MARITIMES ON THURSDAY. EXPECT CLOUDY SKIES AND SCATTERED
SHOWERS THURSDAY THROUGH FRIDAY WITH HIGHS IN THE 40S TO LOWER
50S.
SHOWER ACTIVITY WILL DIMINISH OVER THE WEEKEND BUT SKIES WILL
REMAIN MOSTLY CLOUDY WITH RAIN OR SNOW SHOWERS POSSIBLE MAINLY IN
NORTHERN ZONES.
&&
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
SHORT TERM...MVFR WILL DETERIORATE TO LIFR AND IFR SHORTLY AS
HEAVIER RAIN MOVES IN. RAIN MAY BE LIGHTER AT KHIE WHERE WE WILL
SEE THE RAIN SHADOW EFFECT. ALSO SOME SNOW MAY MIX IN LATE IN THE
NORTH. EAST WINDS MAY GUST TO 35 KTS AT TIMES. SOME IMPROVEMENT BY
MID MORNING TUESDAY AS RAIN MOVES EAST.
LONG TERM...AREAS OF MVFR CEILINGS WEDNESDAY THROUGH FRIDAY.
&&
.MARINE...
SHORT TERM...EASTERLY WINDS AND SEAS CONTINUE TO BUILD TONIGHT. A
GALE WARNING REMAINS IN EFFECT THROUGH 2 PM TUESDAY. WINDS WILL
DECREASE BUT A SCA WILL LIKELY BE NEEDED FOR WAVES THROUGH
WEDNESDAY EVENING.
LONG TERM...SCA`S MAY BE NEEDED THURSDAY AND FRIDAY.
&&
.FIRE WEATHER...
ONSHORE FLOW TODAY BRINGS MORE MOISTURE AND EVENTUALLY RAIN TO
THE AREA. A SOAKING RAIN IS EXPECTED LATE TODAY AND TUESDAY.
&&
.HYDROLOGY...
A WIDESPREAD 1 TO 2 INCHES OF RAIN IS EXPECTED FROM THIS
AFTERNOON THROUGH TUESDAY. HOWEVER...GIVEN STRONG MOISTURE
INFLOW...LOCALIZED AMOUNTS OF UP TO 3 INCHES COULD OCCUR. THIS
WOULD LEAD TO FLOODING PROBLEMS...ESPECIALLY IN AREAS WHERE SNOW
MELT IS STILL OCCURRING. A FLOOD WATCH REMAINS IN EFFECT.
&&
.TIDES/COASTAL FLOODING...
AS EASTERLY WINDS CONTINUE TO INCREASE...SEAS WILL BUILD 10 TO 15
FT. HIGH TIDE ON APRIL 21 IS AT 1:21 AM WITH A PREDICTED HEIGHT OF
11.4 FT MLLW. HOWEVER...ONSHORE WINDS ARE EXPECTED TO RESULT IN A 1-
2 FT STORM SURGE. THE COMBINATION OF WIND, WAVES AND HIGH TIDE WILL
RESULT IN OVERWASH AND POSSIBLE INUNDATION FOR THE BEACHES OF THE
SOUTH COAST OF MAINE AND NEW HAMPSHIRE. FARTHER DOWNEAST THE
EASTERLY WIND DIRECTION IS LESS FAVORABLE FOR ONSHORE INUNDATION.
EVEN SO THE SIGNIFICANT WAVES MAY RESULT IN SOME COASTAL FLOODING
AND A COASTAL FLOOD ADVISORY HAS BEEN POSTED THERE.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...FLOOD WATCH THROUGH WEDNESDAY MORNING FOR MEZ007>009-012>014-
018>028.
COASTAL FLOOD ADVISORY UNTIL 3 AM EDT TUESDAY FOR MEZ025>028.
COASTAL FLOOD WARNING UNTIL 3 AM EDT TUESDAY FOR MEZ023-024.
NH...FLOOD WATCH THROUGH WEDNESDAY MORNING FOR NHZ002>015.
COASTAL FLOOD WARNING UNTIL 3 AM EDT TUESDAY FOR NHZ014.
MARINE...GALE WARNING UNTIL 2 PM EDT TUESDAY FOR ANZ150>154.
&&
$$
NEAR TERM...LEGRO
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
717 PM EDT MON APR 20 2015
.SYNOPSIS...
LOW PRESSURE MEANDERING NORTH OF THE GREAT LAKES WILL DRIVE A COLD
FRONT TOWARD THE REGION TONIGHT. THE FRONT WILL SLOWLY CROSS THE
REGION ON TUESDAY. LOW PRESSURE NORTH OF THE GREAT LAKES WILL
GRADUALLY WEAKEN AS IT DRIFTS SOUTHEAST INTO NEW ENGLAND WEDNESDAY
THROUGH THURSDAY. LOW PRESSURE WILL CONTINUE TO WEAKEN AS IT
MEANDERS NORTH OF NEW ENGLAND FRIDAY THROUGH SATURDAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
UPDATE...WITH LLJ EXPECTED TO PEAK IN INTENSITY OVER THE NEXT FEW
HOURS AND WIND GUSTING 40 PLUS MPH ALREADY...I HAVE ISSUED A WIND
ADVISORY FOR COOS AND NRN GRAFTON COUNTIES. THE STRONG DOWNSLOPE
WIND GUSTS SHOULD BE CONFINED TO THE IMMEDIATE NW SLOPES OF THE
HIGH TERRAIN. AFTER MIDNIGHT WINDS WILL DIMINISH AS LLJ LIFTS
NEWD.
HAVE MODIFIED THE GRIDS THRU MORNING BASED ON LATEST HI-RES MODEL
GUIDANCE. EXAMINING RECENT HRRR RUNS HAVE A LARGE AREA FAVORABLE
FOR LIGHTNING DEVELOPMENT MOVING ACROSS THE REGION ON THE LEADING
EDGE OF THE DRY SLOT NEAR MORNING. IN ADDITION...THE SPC SSEO
PRODUCTS ALSO FAVOR A CLUSTER OR LINE OF TSTMS CROSSING THE
FORECAST AREA NEAR 12Z. HAVE INCREASED THE PROBABILITY FOR THUNDER
LATE TONIGHT AND EARLY TUE AS A RESULT.
HAVE ALSO INTRODUCED SOME AREAS OF HEAVY RA TO THE GRIDS NEAR THE
COASTAL FRONT AS WELL AS IN THE EAST SLOPES OF THE MTNS WHERE
STRONG SELY LLJ WILL IMPINGE UPON THE TERRAIN.
THIS LLJ...WHICH IS REALLY JUST GETTING UNDERWAY OVER SRN NEW
ENGLAND PER KBOX 88D...WILL SLOWLY TRAVERSE THE COAST THRU ABOUT
06Z. THIS PUTS HEAVIEST PRECIP IN THE FORECAST AREA BETWEEN ABOUT
00Z AND 06Z. IN ADDITION TO THE HEAVY PRECIP...THIS LLJ MAY INDUCE
SOME STRONG DOWNSLOPE WIND GUSTS NW OF THE WHITE MTNS.
PREVIOUS DISCUSSION...THE FIRST BATCH OF RAIN FROM THIS MORNING
WAS MOVING INTO EASTERN MAINE AS A WARM FRONT LIFTED NORTH INTO
SOUTHERN CANADA. SO FAR ONLY A TENTH TO ABOUT A THIRD OF AN INCH
OF RAIN HAS FALLEN TODAY WITH SOME ISOLATED HIGHER AMOUNTS. THIS
MORNINGS GYX SOUNDING HAD PLENTY OF DRY AIR AND THIS INHIBITED
RAINFALL FROM SPREADING FASTER FOR THE FIRST HALF OF THE DAY.
STEADIER RAINS ARE NOW OVER SOUTHERN NH AND MOVING INTO WESTERN
MAINE. THIS TREND WILL CONTINUE INTO THE EVENING HOURS.
A SECONDARY CYCLONE WILL FORM TONIGHT OVER THE VIRGINIAS AND MOVE
NE ALONG THE ATLANTIC COAST. AS IT DEEPENS IN THE GULF OF MAINE A
LLJ WILL STRENGTHEN AND FEED MOISTURE RICH AIR INTO COASTAL NH AND
MAINE. WARM RAIN PROCESSES AND TRAINING OF CELLS WILL SUPPORT HEAVY
RAIN OVERNIGHT AND INTO TUESDAY. A FLOOD WATCH REMAINS IN EFFECT AS
RAIN COMBINES WITH SNOWMELT TO BRING RIVERS AND STREAMS TO NEAR
BANKFULL.
WINDS WILL BE GUSTY... ESPECIALLY ALONG THE COAST... BUT WE
SHOULD FALL SHORT OF WIND ADVISORY CRITERIA. COASTAL FLOODING WILL
ALSO BE A CONCERN FROM PORTLAND WESTWARD AS EASTERLY FLOW
INCREASES AND COINCIDES WITH THE ASTRONOMICAL HIGH TIDE. MORE
INFORMATION ON THESE HAZARDS BELOW.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
MODERATE TO HEAVY RAIN CONTINUES INTO TUESDAY MORNING. MUCAPE
VALUES INDICATE A SLIGHT CHANCE FOR THUNDERSTORMS BETWEEN 12-18Z
TOMORROW AS THE COLD CORE OF THE UPPER LOW SWINGS BY OVERHEAD.
DRIER AIR PUNCHES IN FROM THE SW MIDDAY TUESDAY. SOME LINGERING
SHOWERS WILL BE POSSIBLE OVER THE MOUNTAINS IN UPSLOPE FLOW. HIGHS
SHOULD WARM INTO THE UPPER 40S NORTH TO LOWER 60S SOUTH.
ADDITIONAL SHOWERS WILL BE POSSIBLE TUESDAY NIGHT WITH CYCLONIC
FLOW ALOFT.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
BROAD UPPER LEVEL CLOSED LOW WILL KEEP WEATHER UNSETTLED
IN THE NORTHEAST THROUGH THE WEEK AND INTO THE WEEKEND AS
IT GRADUALLY SHIFTS EAST. EXPECT SEVERAL LOBES OF ENERGY
TO ROTATE AROUND THIS SYSTEM AND INTO THE NORTHEAST. ANY
MORNING SUN ON WEDNESDAY WILL QUICKLY GIVE WAY TO CLOUDS
AND SHOWERS AS THE FIRST OF THESE DISTURBANCES SWINGS INTO
THE REGION. EXPECT THESE SHOWERS TO PERSIST INTO WEDNESDAY
NIGHT AS A WEAK SURFACE LOW SLOWLY CROSSES THE REGION.
STEADIER PRECIP WILL COME TO AN END AS LOW PRESSURE LIFTS INTO
THE MARITIMES ON THURSDAY. EXPECT CLOUDY SKIES AND SCATTERED
SHOWERS THURSDAY THROUGH FRIDAY WITH HIGHS IN THE 40S TO LOWER
50S.
SHOWER ACTIVITY WILL DIMINISH OVER THE WEEKEND BUT SKIES WILL
REMAIN MOSTLY CLOUDY WITH RAIN OR SNOW SHOWERS POSSIBLE MAINLY IN
NORTHERN ZONES.
&&
.AVIATION /23Z MONDAY THROUGH SATURDAY/...
SHORT TERM...MVFR WILL DETERIORATE TO LIFR AND IFR SHORTLY AS
HEAVIER RAIN MOVES IN. RAIN MAY BE LIGHTER AT KHIE WHERE WE WILL
SEE THE RAIN SHADOW EFFECT. ALSO SOME SNOW MAY MIX IN LATE IN THE
NORTH. EAST WINDS MAY GUST TO 35 KTS AT TIMES. SOME IMPROVEMENT BY
MID MORNING TUESDAY AS RAIN MOVES EAST.
LONG TERM...AREAS OF MVFR CEILINGS WEDNESDAY THROUGH FRIDAY.
&&
.MARINE...
SHORT TERM...EASTERLY WINDS AND SEAS CONTINUE TO BUILD TONIGHT. A
GALE WARNING REMAINS IN EFFECT THROUGH 2 PM TUESDAY. WINDS WILL
DECREASE BUT A SCA WILL LIKELY BE NEEDED FOR WAVES THROUGH
WEDNESDAY EVENING.
LONG TERM...SCA`S MAY BE NEEDED THURSDAY AND FRIDAY.
&&
.FIRE WEATHER...
ONSHORE FLOW TODAY BRINGS MORE MOISTURE AND EVENTUALLY RAIN TO
THE AREA. A SOAKING RAIN IS EXPECTED LATE TODAY AND TUESDAY.
&&
.HYDROLOGY...
A WIDESPREAD 1 TO 2 INCHES OF RAIN IS EXPECTED FROM THIS
AFTERNOON THROUGH TUESDAY. HOWEVER...GIVEN STRONG MOISTURE
INFLOW...LOCALIZED AMOUNTS OF UP TO 3 INCHES COULD OCCUR. THIS
WOULD LEAD TO FLOODING PROBLEMS...ESPECIALLY IN AREAS WHERE SNOW
MELT IS STILL OCCURRING. A FLOOD WATCH REMAINS IN EFFECT.
&&
.TIDES/COASTAL FLOODING...
AS EASTERLY WINDS CONTINUE TO INCREASE...SEAS WILL BUILD 10 TO 15
FT. HIGH TIDE ON APRIL 21 IS AT 1:21 AM WITH A PREDICTED HEIGHT OF
11.4 FT MLLW. HOWEVER...ONSHORE WINDS ARE EXPECTED TO RESULT IN A 1-
2 FT STORM SURGE. THE COMBINATION OF WIND, WAVES AND HIGH TIDE WILL
RESULT IN OVERWASH AND POSSIBLE INUNDATION FOR THE BEACHES OF THE
SOUTH COAST OF MAINE AND NEW HAMPSHIRE. FARTHER DOWNEAST THE
EASTERLY WIND DIRECTION IS LESS FAVORABLE FOR ONSHORE INUNDATION.
EVEN SO THE SIGNIFICANT WAVES MAY RESULT IN SOME COASTAL FLOODING
AND A COASTAL FLOOD ADVISORY HAS BEEN POSTED THERE.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...FLOOD WATCH THROUGH WEDNESDAY MORNING FOR MEZ007>009-012>014-
018>028.
COASTAL FLOOD ADVISORY FROM 11 PM THIS EVENING TO 3 AM EDT
TUESDAY FOR MEZ025>028.
COASTAL FLOOD WARNING FROM 11 PM THIS EVENING TO 3 AM EDT
TUESDAY FOR MEZ023-024.
NH...FLOOD WATCH THROUGH WEDNESDAY MORNING FOR NHZ002>015.
WIND ADVISORY UNTIL 1 AM EDT TUESDAY FOR NHZ001>003.
COASTAL FLOOD WARNING FROM 11 PM THIS EVENING TO 3 AM EDT
TUESDAY FOR NHZ014.
MARINE...GALE WARNING UNTIL 2 PM EDT TUESDAY FOR ANZ150>154.
&&
$$
NEAR TERM...LEGRO
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
248 PM EDT SUN APR 19 2015
.SYNOPSIS...
SHOWERS WILL OVERSPREAD THE REGION THIS EVENING AND CONTINUE
THROUGH MONDAY. UNSEASONABLY COOL TEMPERATURES ARE EXPECTED FOR
THE REMAINDER OF THE WEEK.
&&
.NEAR TERM /THROUGH MONDAY/...
DRY AIR SAMPLED BY THE 12Z UPPER AIR SOUNDING REVEALS A
SUBSTANTIAL LAYER OF DRY AIR. THIS HAS KEPT THE RAIN AND CLOUDS AT
BAY FOR MUCH OF THE DAY...ALLOWING FOR TEMPERATURES TO RISE
QUICKLY ABOVE NORMAL. TEMPERATURE RISES HAVE BEEN AIDED...AT LEAST
IN PART...BY DOWNSLOPING EASTERLY FLOW SUSTAINED AT 10-15KTS WITH
GUSTS CLOSE TO 25KTS.
TEMPERATURES THIS EVENING WILL DECREASE ACROSS THE SOUTH FIRST AS
THE THICKER CLOUD COVER AND EVENTUAL RAIN SHOWERS MOVE IN. TIMING
THE ONSET OF PRECIPITATION HAS BEEN PUSHED BACK AN HOUR OR TWO FOR
MOST LOCATIONS TO ACCOUNT FOR THE DRY AIR IN PLACE. KEEPING
CATEGORICAL POPS IN FOR THIS EVENING/EARLY TONIGHT...DESPITE
SEVERAL OF THE LATEST HRRR RUNS CONTINUING TO SHOW CONSIDERABLE
MOISTURE EROSION UPON ARRIVAL...RESULTING IN TRIMMING OF QPF
GENERATION. ALL OTHER GUIDANCE INCLUDING THE VARIOUS OTHER HI-RES
MODELS SHOW THE CURRENT SWATH OF RAIN ALONG THE WARM FRONT
HOLDING TOGETHER THROUGH OUR AREA.
TONIGHT THE DRY SLOT IN THE WARM SECTOR WILL RESULT IN A LULL IN PRECIPITATION
THAT IS EXPECTED TO LAST THROUGH DAYBREAK. CLOUDS MAY DIMINISH TO
THE POINT WHERE POCKETS OF CLEARING COULD AID THE MONDAY MORNING
WARM-UP AS STRONG SOUTHEASTERLY FLOW VEERS SOUTHERLY. COLDER AIR
ADVANCING EASTWARD ALOFT WILL RESULT IN INSTABILITY AND DRIVE
THUNDERSTORM ACTIVITY ALONG AND AHEAD OF THE COLD FRONT. A SLIGHT
RISK OF SEVERE THUNDERSTORMS IS INCLUDED FOR OUR AREA...WITH THE
MAIN THREAT BEING DAMAGING WINDS. TAX
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
FRONT WILL BE IN OR JUST EAST OF THE RIDGES AT 00Z TUESDAY...WITH
A SECONDARY COLD FRONT LAGGING BEHIND WITH THE UPPER LEVEL COLD
AIR. ENOUGH MOISTURE AND STEEP ENOUGH LAPSE RATES REMAIN BEHIND
THE IMMEDIATE SURFACE BOUNDARY TO KEEP SHRA/TSRA CHANCES GOING
THROUGH MUCH OF THE NIGHT. DRIER AIR SHOULD ALLOW PRECIPITATION TO
CEASE AREAWIDE BY 12Z.
MODELS ARE IN GENERAL AGREEMENT THAT DECAYING MISSISSIPPI VALLEY
SHORTWAVE GETS ABSORBED BY DEEPENING UPPER LOW...WHICH DROPS INTO
THE NORTHERN GREAT LAKES BY 12Z TUESDAY. THIS LEADS TO A TROUGHING
PATTERN FOR THE NORTHEAST U.S. WHICH LOOKS TO PERSIST FOR SOME
TIME. CONFIDENCE IS HIGH IN THESE DETAILS. HOWEVER...TIMING OF
INDIVIDUAL SHORTWAVES ROTATING AROUND BECOMES MORE PROBLEMATIC
WITH TIME.
MAIN VORT LOBE RESIDES IN OR NEAR OUR NORTHERN COUNTIES
TUESDAY. THIS PLUS BETTER INSTABILITY LEADS TO HIGHER POPS IN THIS
AREA TUESDAY AFTERNOON/EVENING. HELD OFF ON THUNDER FOR NOW WITH
EQUILIBRIUM LEVELS MOSTLY BELOW 15K FEET...BUT THIS MAY HAVE TO BE
REEVALUATED WITH COLD TEMPS ALOFT EXPECTED.
A WEAK IMPULSE MAINLY AFFECTS THE SOUTHERN COUNTIES WITH A FEW
SHRA TUESDAY NIGHT. THE NEXT...MORE ORGANIZED...FRONTAL BOUNDARY
ARRIVES WEDNESDAY WITH BETTER RAIN CHANCES AREAWIDE. BEHIND THE
FRONT...BOUNDARY LAYER MAY BE ABLE TO COOL SUFFICIENTLY TO ALLOW
SNOWFLAKES TO MIX IN NORTH OF PIT LATE WEDNESDAY NIGHT...BUT NO
ACCUMULATION IS FORESEEN.
A GENERAL COOLING TREND IN TEMPERATURE WILL BE SEEN WITH VALUES
SINKING BELOW NORMAL BY THE END OF THE PERIOD. CL
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
BROAD UPPER TROUGHING WILL REMAIN OVER THE EASTERN CONUS THROUGH
THE EXTENDED AND RESULT IN BELOW NORMAL TEMPERATURES EACH DAY
ALONG WITH CLOUDY SKIES AND SLIGHT CHANCES FOR PRECIPITATION
THROUGHOUT THE PERIOD AS SHORTWAVES TRANSITION THROUGH THE FLOW
AND CAA ALOFT PERSISTS. CONFIDENCE IS HIGH IN THE GENERAL FORECAST
AS MODELS HAVE BEEN FAIRLY CONSISTENT IN PROGGING THIS LONGWAVE
PATTERN...REFLECTED IN LATEST RMOP AND MODTRENDS GUIDANCE.
HOWEVER...CONFIDENCE IN TIMING OF ANY MORE SIGNIFICANT PERIODS OF
PRECIPITATION IS RELATIVELY LOW. FORECAST MAX/MIN TEMPERATURES ARE
NOT EXCEPTIONALLY COLD...BUT PERSISTENT AROUND 10 DEGREES BELOW
NORMALS AS ENSEMBLE ANOMALIES ARE SHOWING TEMPS AND HEIGHTS ALOFT
ONLY RANGING FROM 1-2 STANDARD DEVIATIONS BELOW NORMAL THROUGH THE
PERIOD.
&&
.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
HIGH CIRRUS CONTINUES TO MOVE SLOWLY ACROSS THE AREA...BUT NO
RESTRICTIONS ARE ANTICIPATED UNTIL THE RAIN SHOWERS ASSOCIATED
WITH THE WARM FRONT ARRIVE THIS EVENING. EXPECTING RAIN TO FALL
OUT OF MOSTLY VFR CIGS INITIALLY...BUT HEADING INTO THE OVERNIGHT
THE CIGS SHOULD CONTINUE THIER DESCENT TO MVFR. CEILINGS MAY BE
BROKEN AS WE HEAD INTO MIDDAY MONDAY...WITH THUNDERSTORMS EXPECTED
THROUGH AFTERNOON.
GUSTY EAST-SOUTHEASTERLY FLOW WILL CONTINUE EVENING AND
OVERNIGHT...GRADUALLY RELAXING THROUGH THE EARLY MORNING MONDAY.
SURFACE FLOW WILL AGAIN INCREASE AS IT VEERS MORE SOUTHERLY MONDAY
AFTERNOON. TAX
.OUTLOOK.../SUNDAY NIGHT THROUGH THURSDAY/...
RESTRICTIONS ARE POSSIBLE WITH A MID WEEK UPPER TROUGH.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
218 PM EDT SUN APR 19 2015
.SYNOPSIS...
SHOWERS WILL OVERSPREAD THE REGION THIS EVENING AND CONTINUE
THROUGH MONDAY. UNSEASONABLY COOL TEMPERATURES ARE EXPECTED FOR
THE REMAINDER OF THE WEEK.
&&
.NEAR TERM /THROUGH MONDAY/...
DRY AIR SAMPLED BY THE 12Z UPPER AIR SOUNDING REVEALS A
SUBSTANTIAL LAYER OF DRY AIR. THIS HAS KEPT THE RAIN AND CLOUDS AT
BAY FOR MUCH OF THE DAY...ALLOWING FOR TEMPERATURES TO RISE
QUICKLY ABOVE NORMAL. TEMPERATURE RISES HAVE BEEN AIDED...AT LEAST
IN PART...BY DOWNSLOPING EASTERLY FLOW SUSTAINED AT 10-15KTS WITH
GUSTS CLOSE TO 25KTS.
TEMPERATURES THIS EVENING WILL DECREASE ACROSS THE SOUTH FIRST AS
THE THICKER CLOUD COVER AND EVENTUAL RAIN SHOWERS MOVE IN. TIMING
THE ONSET OF PRECIPITATION HAS BEEN PUSHED BACK AN HOUR OR TWO FOR
MOST LOCATIONS TO ACCOUNT FOR THE DRY AIR IN PLACE. KEEPING
CATEGORICAL POPS IN FOR THIS EVENING/EARLY TONIGHT...DESPITE
SEVERAL OF THE LATEST HRRR RUNS CONTINUING TO SHOW CONSIDERABLE
MOISTURE EROSION UPON ARRIVAL...RESULTING IN TRIMMING OF QPF
GENERATION. ALL OTHER GUIDANCE INCLUDING THE VARIOUS OTHER HI-RES
MODELS SHOW THE CURRENT SWATH OF RAIN ALONG THE WARM FRONT
HOLDING TOGETHER THROUGH OUR AREA.
TONIGHT THE DRY SLOT IN THE WARM SECTOR WILL RESULT IN A LULL IN PRECIPITATION
THAT IS EXPECTED TO LAST THROUGH DAYBREAK. CLOUDS MAY DIMINISH TO
THE POINT WHERE POCKETS OF CLEARING COULD AID THE MONDAY MORNING
WARM-UP AS STRONG SOUTHEASTERLY FLOW VEERS SOUTHERLY. COLDER AIR
ADVANCING EASTWARD ALOFT WILL RESULT IN INSTABILITY AND DRIVE
THUNDERSTORM ACTIVITY ALONG AND AHEAD OF THE COLD FRONT. A SLIGHT
RISK OF THUNDERSTORMS IS INCLUDED FOR OUR AREA...WITH THE MAIN
THREAT BEING DAMAGING WINDS.
TAX
&&
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY/...
SHOWER COVERAGE WILL DECREASE OVERNIGHT AS UPPER LEVEL SUPPORT
SHIFTS TO THE EAST AND A LARGE UPPER LEVEL DRY SLOT OVERSPREADS
THE AREA.
THE RESULTING SUBSIDENCE IS EXPECTED TO CONTINUE THROUGH MONDAY
MORNING...AND MAY PROMOTE MODEST HEATING OF A RELATIVELY-MOIST
BOUNDARY LAYER WITH 45-50KT OF SOUTHWEST FLOW ALOFT.
A SECOND SHORTWAVE TROUGH IS PROJECTED TO MOVE QUICKLY NORTHEASTWARD
AND CROSS THE REGION BY LATE DAY. LIFT IN ASSOCIATION WITH THAT
DISTURBANCE WOULD AID CONVECTIVE DEVELOPMENT DURING THE
AFTERNOON. SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED WITH
THIS SCENARIO. WIDESPREAD SEVERE THUNDERSTORMS ARE NOT EXPECTED
OWING TO PROGNOSIS OF WEAK MID LEVEL LAPSE RATES.
UNUSUALLY STRONG UPPER LOW PRESSURE IS FORECAST TO BUILD SEWD
INTO THE GREAT LAKES REGION BY TUESDAY...WITH ITS ASSOCIATED COLD
FRONT TO CROSS THE FORECAST AREA DURING THE MORNING.
COLD ADVECTION BEHIND THE FRONTAL PASSAGE IS PROGGED TO PROVIDE
INCREASED COVERAGE OF STRATOCU AND POSSIBLE LAKE ENHANCEMENT TO
LIGHT PRECIPITATION...WITH THAT LIMITED TO THE NORTHERN ZONES WITH
EXPECTATIONS OF WESTERLY FETCH AND DRY ADVECTION.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
BROAD UPPER TROUGHING WILL REMAIN OVER THE EASTERN CONUS THROUGH
THE EXTENDED AND RESULT IN BELOW NORMAL TEMPERATURES EACH DAY
ALONG WITH CLOUDY SKIES AND SLIGHT CHANCES FOR PRECIPITATION
THROUGHOUT THE PERIOD AS SHORTWAVES TRANSITION THROUGH THE FLOW
AND CAA ALOFT PERSISTS. CONFIDENCE IS HIGH IN THE GENERAL FORECAST
AS MODELS HAVE BEEN FAIRLY CONSISTENT IN PROGGING THIS LONGWAVE
PATTERN...REFLECTED IN LATEST RMOP AND MODTRENDS GUIDANCE.
HOWEVER...CONFIDENCE IN TIMING OF ANY MORE SIGNIFICANT PERIODS OF
PRECIPITATION IS RELATIVELY LOW. FORECAST MAX/MIN TEMPERATURES ARE
NOT EXCEPTIONALLY COLD...BUT PERSISTENT AROUND 10 DEGREES BELOW
NORMALS AS ENSEMBLE ANOMALIES ARE SHOWING TEMPS AND HEIGHTS ALOFT
ONLY RANGING FROM 1-2 STANDARD DEVIATIONS BELOW NORMAL THROUGH THE
PERIOD.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
HIGH CIRRUS CONTINUES TO MOVE SLOWLY ACROSS THE AREA...BUT NO
RESTRICTIONS ARE ANTICIPATED UNTIL THE RAIN SHOWERS ASSOCIATED
WITH THE WARM FRONT ARRIVE THIS EVENING. EXPECTING RAIN TO FALL
OUT OF MOSTLY VFR CIGS INITIALLY...BUT HEADING INTO THE OVERNIGHT
THE CIGS SHOULD CONTINUE THIER DESCENT TO MVFR. CEILINGS MAY BE
BROKEN AS WE HEAD INTO MIDDAY MONDAY...WITH THUNDERSTORMS EXPECTED
THROUGH AFTERNOON.
GUSTY EAST-SOUTHEASTERLY FLOW WILL CONTINUE EVENING AND
OVERNIGHT...GRADUALLY RELAXING THROUGH THE EARLY MORNING MONDAY.
SURFACE FLOW WILL AGAIN INCREASE AS IT VEERS MORE SOUTHERLY MONDAY
AFTERNOON. TAX
.OUTLOOK.../SUNDAY NIGHT THROUGH THURSDAY/...
RESTRICTIONS ARE POSSIBLE WITH A MID WEEK UPPER TROUGH.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
747 PM EDT MON APR 20 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 353 PM EDT MON APR 20 2015
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW DEEPENING UPR TROF
OVER CENTRAL NAMERICA BTWN RDGS ALONG THE E AND W COASTS...WITH 12HR
H5 HGT FALLS UP TO 150M NOTED OVER NRN WI IN ADVANCE OF SHRTWV
LIFTING NWD INTO THE UPR LKS TO THE E OF THE UPR TROF AXIS. IR AND
WV IMAGERY SHOW A WELL DEFINED COMMA HEAD CLD OVER THE UPR GREAT LKS
IN ADVANCE OF SHRTWV AND ON CYC SIDE OF ACCOMPANYING H7 LO TRACK.
STEADY RA UNDER THIS COMMA HEAD HAS MIXED WITH SN OVER THE WRN CWA
WHERE DYNAMIC COOLING AND SOME LLVL CAA HAVE COOLED THE COLUMN
SUFFICIENTLY. FARTHER TO THE E...DRY SLOTTING ON THE ACYC SIDE OF H7
LO TRACK HAS TENDED TO DIMINISH THE PCPN COVERAGE/INTENSITY OVER THE
FAR E. ANOTHER SHRTWV IS DIGGING SWD THRU FAR NW ONTARIO/MANITOBA ON
THE WRN FLANK OF H5 CLOSED LO
MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON POPS/PTYPE ASSOCIATED
WITH SHRTWV MOVING THRU THE UPR LKS RIGHT NOW AND THEN TNGT/TMRW
ACCOMPANYING PASSAGE OF NEXT SHRTWV AND WITHIN LINGERING DEEP CYC
FLOW UNDER CUTOFF H5 LO PROGGED TO LINGER OVER THE UPR LKS.
LATE TDAY/TNGT...AS SHRTWV E OF THE UPR TROF AXIS LIFTS TO THE N
THRU THIS AFTN AND TENDS TO SHEAR OUT...MODELS SHOW AREA OF SHARP
DEEP LYR QVECTOR CNVGC SUPPORTING AXIS OF COLDER CLD TOPS
DIMINISHING AND GIVING WAY TO SOME DEEP LYR QVECTOR DVGC. SO AREA OF
STEADY RA/SN OVER THE W SHOULD DIMINISH BY LATE AFTN WITH ARRIVAL OF
THE NEGATIVE DYNAMICS/MID LVL DRYING. POPS OVER THE E WL TEND TO
INCREASE LATE THIS AFTN/EARLY EVNG AS COMMA TAIL AXIS OF HIER RH
SWINGS E THRU THAT AREA...BUT PCPN INTENSITY WL NOT BE AS GREAT AS
OVER THE W SINCE THE SUPPORTING AXIS OF DIMINISHING DEEP LYR QVECTOR
CNVGC IS FCST TO REMAIN OVER THE W. NOT OUT OF THE QUESTION THERE
COULD BE A FEW INCHES OF WET SN ACCUM OVER THE HIER TERRAIN OF THE
W...BUT THERE SHOULD BE LTL IF ANY SN OVER THE E HALF WITH WEAKER
DYNAMIC FORCING/COOLING. LATER TNGT...THE TRAILING SHRTWV DIGGING
SWD TOWARD NW MN ON THE WRN FLANK OF CLOSED H5 LO IS FCST TO DIG TO
NEAR NW WI BY 12Z TUE...BRINGING SOME DPVA/MORE DEEP LYR QVECTOR
CNVGC TO THE W LATER TNGT. SHARP CYC UPSLOPE WNW FLOW IN THE
PRESENCE OF THE DEEPER FORCING/MSTR WL SUPPORT LIKELY POPS IN THIS
AREA. THERE COULD BE A FEW INCHES OF WET SN ACCUM OVER MAINLY THE
HIER TERRAIN. OVER THE CENTRAL AND E...THERE WL BE ONLY ISOLD-SCT RA
AND SN SHOWERS.
TUE...SHRTWV/ACCOMPANYING SFC LO PRES TROF ROTATING ARND CLOSED H5
LO SHIFTING SLOWLY TO THE E OVER LK SUP IS FCST TO WEAKEN SLOWLY...
LEADING TO SLOWLY DIMINISHING DEEP LYR QVECTOR CNVGC. ALTHOUGH THESE
TRENDS WL RESULT IN DIMINISHING POPS...DAYTIME HEATING/LLVL
DESTABILIZATION WL ENHANCE POPS ESPECIALLY OVER THE ERN CWA IN THE
AFTN...WHERE LLVL CNVGC WITHIN LO PRES TROF WL BE ENHANCED BY LK
BREEZE DEVELOPMENT. OTRW...LINGERING SHARP LLVL CNVGC AND THE
DAYTIME HEATING WL MAINTAIN AT LEAST CHC POPS. THE PCPN SHOULD BE
MAINLY SN IN THE MRNG...BUT THIS PCPN WL MIX WITH/CHG TO RA OVER THE
SE HALF IN THE AFTN WITH DAYTIME HEATING/TEMPS RISING AOA 40.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 338 PM EDT MON APR 20 2015
A LARGE UPPER LOW CENTERED OVER NORTHERN ONTARIO WILL BE
INFLUENCING THE GREAT LAKES REGION THROUGH THE FIRST HALF OF THE
LONG TERM PERIOD. THIS WILL LEAD TO BELOW NORMAL TEMPERATURES AND
PERIODS OF SNOW BEFORE GRADUALLY SHIFTING EAST INTO THE ATLANTIC BY
THE WEEKEND.
AS THAT UPPER LOW SPINS BETWEEN LAKE SUPERIOR AND JAMES BAY...IT
WILL ROTATE SEVERAL SHORTWAVES ACROSS THE UPPER GREAT LAKES REGION
TUESDAY NIGHT THROUGH THURSDAY. THESE WAVES WILL BRING PERIODS OF
SHOWERS TO THE AREA...WITH HELP FROM BOTH LAKE SUPERIOR (850MB
TEMPS FALLING TO -10C TO -12C ON WEDNESDAY MORNING) AND TERRAIN
ENHANCEMENT (PERSISTENT LOW LEVEL NORTHWESTERLY FLOW). WILL CONTINUE
TO FOCUS THE HIGHEST POPS (LIKELY VALUES) IN THOSE AREAS FAVORED BY
ALL THREE FEATURES (HIGHER TERRAIN OF THE WEST/NORTHWEST) AND ALSO
EAST DOWNWIND OF LAKE SUPERIOR...AND INCLUDE CHANCE/SLIGHTS FOR THE
REST OF THE CWA. WITH THE AMOUNT OF COLD AIR IN PLACE...EXPECT THE
PRECIPITATION TO FALL MAINLY AS SNOW. WITH LOW LEVEL TEMPERATURES
WARMING AWAY OVER THE SOUTHERN THIRD OF THE CWA...COULD SEE SOME
RAIN MIXING IN THERE...BUT OTHERWISE SNOW WILL BE THE NORM. COULD
SEE A COUPLE INCHES OF ACCUMULATION IN THE FAVORED LOCATIONS
TUESDAY NIGHT AND UP TO AN INCH WEDNESDAY AND AGAIN WEDNESDAY
NIGHT. WITH DRIER AIR STARTING TO MOVE INTO THE AREA ON
THURSDAY (ASSOCIATED WITH A SURFACE RIDGE MOVING INTO THE
NORTHERN PLAINS...SHOULD SEE THE COVERAGE OF THE SHOWERS
DIMINISHING THROUGH THE DAY THURSDAY AND CONTINUING TO WEAKENING
INTO FRIDAY. ALSO...DON/T EXPECT HIGHS TO RISE MUCH OUT OF THE
LOW-MID 30S ON WED/THURS OVER THE NORTH HALF OF THE CWA...WITH SOME
HIGHS AROUND 40 OVER THE SOUTH CENTRAL. WILL LIKELY BREAK THE
RECORD LOW HIGH TEMPERATURE HERE AT OUR OFFICE ON WEDNESDAY (36 SET
IN 1972).
EXTENDED RANGE MODELS DIFFER ON HOW QUICKLY THE UPPER LOW DEPARTS
THIS WEEKEND...BUT SHOULD STILL SEE ENOUGH INFLUENCE FROM THE
SURFACE RIDGE MOVING INTO THE NORTHERN PLAINS TO KEEP MOST OF THE
AREA DRY. WITH THE NORTHERLY FLOW OFF LAKE SUPERIOR...EXPECT
TEMPERATURES TO REMAIN BELOW NORMAL BUT IN THE 40S TO AROUND 50. AS
THE UPPER LOW RETROGRADES BACK OVER QUEBEC EARLY NEXT WEEK...COULD
SEE THE UPPER GREAT LAKES REGION BEING AFFECTED BY THE WESTERN EDGE
OF THE ENERGY ROTATING AROUND THE UPPER LOW AND LIKELY KEEPING
BELOW NORMAL TEMPERATURES IN PLACE THROUGH THE END OF APRIL.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 747 PM EDT MON APR 20 2015
AREA OF DEEPER MOISTURE AND STEADIER SNOW CONTINUES TO LIFT NE
ACROSS UPPER MI/LAKE SUPERIOR. BEHIND THIS DEEPER MOISTURE/STEADIER
SNOW...EXPECT MVFR CONDITIONS WITH -SHSN AT TIMES TO PREVAIL AT KIWD
THIS EVENING. AT KCMX...IFR CONDITIONS SHOULD IMPROVE TO MVFR IN THE
NEXT HR OR TWO. AT KSAW...IT`S POSSIBLE MVFR CONDITIONS COULD
IMPROVE TO VFR AT TIMES THIS EVENING. APPROACH OF ANOTHER
DISTURBANCE/LOW PRES TROF LATER TONIGHT SHOULD RESULT IN
DETERIORATING CONDITIONS TO IFR AT KIWD/KCMX. DOWNSLOPE WIND W TO SW
WINDS AT KSAW WILL RESTRICT THE IMPACT THERE...SO MVFR CIGS SHOULD
PREVAIL. AFTER THIS DISTURBANCE EXITS TO THE E...EXPECT MVFR
CONDITIONS TO RETURN TO KIWD/KCMX MID TO LATE MORNING ON TUE. -SHSN
WILL CONTINUE AT ALL TERMINALS TUE...AND IT`S NOT OUT OF THE
QUESTION THAT IFR VIS COULD OCCUR AT TIMES...ESPECIALLY AT KIWD/KSAW
AS DAYTIME HEATING/INSTABILITY AIDS -SHSN INTENSITY. WINDS WILL
GENERALLY REMAIN GUSTY...PARTICULARLY AT KCMX WHERE GUSTS OF 25-30KT
SHOULD BE COMMON FOR MUCH OF THE FCST PERIOD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 353 PM EDT MON APR 20 2015
SHARP PRES GRADIENT ON THE SW FLANK OF SLOW MOVING LO PRES IN
ONTARIO WILL CAUSE W TO NW WINDS UP TO 25-30 KTS INTO THU. ALTHOUGH
THERE COULD BE SOME GALE FORCE GUSTS AT TIMES...WIDESPREAD GALES ARE
NOT EXPECTED. THE CLOSER APPROACH OF HI PRES LATER IN THE WEEK WILL
RESULT IN NW WINDS DIMINISHING TO NO MORE THAN 20 KTS ON FRI AND
SAT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...KC
AREA FORECAST DISCUSSION
NWS DULUTH MN
1220 PM CDT SUN APR 19 2015
.UPDATE...
ISSUED AT 945 AM CDT SUN APR 19 2015
RAIN WILL CONTINUE TO AFFECT THE FORECAST AREA THROUGH THE DAY.
HOWEVER...THERE WILL BE AN HOUR OR TWO WHEN NO RAIN IS OCCURRING
AND TRIED TO ACCOUNT FOR THIS IN THE FORECAST. KEPT THE MAX TEMPS
THE SAME FOR NOW...BUT WILL LOOK INTO LOWERING LATER TODAY. REST
OF THE FORECAST IN THE BALLPARK.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 342 AM CDT SUN APR 19 2015
THE FOCUS REMAINS ON THE RAIN TODAY AND TONIGHT. REFINED THE PCPN
CHANCES BY USING A BLEND OF THE RAP13 AND HRRR MODEL RUNS THROUGH
THIS MORNING SINCE THE TWO MODELS SEEM TO BE DOING PRETTY WELL
CAPTURING THE LOCATION OF THE CURRENT RAIN. DID NOT MAKE ANY
DRAMATIC CHANGES TO RAINFALL. OVERALL...MUCH OF THE FORECAST AREA
CAN EXPECT ABOUT 0.30 TO 0.75 INCHES OF RAINFALL THROUGH TONIGHT.
AT 330 AM...AN AREA OF LOW PRESSURE WAS OVER THE BORDER BETWEEN
SOUTH DAKOTA AND SW MINNESOTA. A FRONTAL BOUNDARY EXTENDED
NORTHWARD TO ANOTHER AREA OF LOW PRESSURE IN SOUTHERN MANITOBA.
THERE WAS AN UPPER LEVEL TROUGH OVER THE NORTHERN HIGH PLAINS AND
SASKATCHEWAN/MANITOBA DIGGING AND DEEPENING TOWARDS THE NORTHERN
PLAINS AND ONTARIO. A LARGE AREA OF RAIN WAS LIFTING TO NNE
THROUGH THE SOUTHERN TWO THIRDS OF THE FORECAST AREA. THIS RAIN
WAS ASSOCIATED WITH A BAND OF MID LEVEL FRONTOGENESIS AHEAD OF THE
LOW NEAR THE SD/MN BORDER. THERE WAS ADDITIONAL RAIN IN EASTERN
SOUTH DAKOTA AND NW MINNESOTA MOVING TO THE EAST IN THE WAKE OF
THE TROUGH BOUNDARY AND AHEAD OF THE UPPER LEVEL TO THE WEST. THE
NORTHLAND HAD CLOUDY SKIES WITH TEMPERATURES IN THE UPPER 30S TO
MIDDLE 40S. THE NORTHLAND HAD LIGHT EASTERLY TO SOUTHEASTERLY
WINDS.
THIS MORNING...THE SURFACE LOW NEAR THE SD/MN BORDER WILL LIFT NE
TO THE AITKIN AREA BY THIS AFTERNOON. THE SURFACE LOW IN SOUTHERN
MANITOBA WILL DIG TO THE SE. THE RAIN OVER THE FORECAST AREA EARLY
THIS MORNING WILL CONTINUE LIFTING TO THE NORTH WITH THE BAND OF
MID LEVEL FRONTOGENESIS. PARTS OF THE NORTHERN FORECAST COULD PICK
UP TO AROUND A HALF INCH OF RAIN THROUGH THIS MORNING. THE COLD
FRONT IN NORTH DAKOTA WILL BEGIN TO MOVE INTO THE WESTERN FORECAST
AREA LATE THIS MORNING.
THIS AFTERNOON AND EVENING...THE TWO LOWS WILL GRADUALLY MERGE
INTO ONE LOW OVER NW ONTARIO. CLOUDY AND COOL WEATHER IS EXPECTED
WITH HIGHS RANGING FROM THE UPPER 40S OVER THE NORTH TO THE 50S
OVER THE SOUTH. MOST OF THE AFTERNOON AND EVENING RAIN WILL BE
OVER THE EASTERN FORECAST AREA AHEAD OF THE EASTWARD ADVANCING
COLD FRONT. A DRY SLOT WILL MOVE INTO THE WESTERN FORECAST
AREA...AND THERE COULD BE PARTIAL CLEARING IN THE SW FORECAST
AREA. ALSO...A PROMINENT BAND OF LOW/MID LEVEL FRONTOGENESIS WILL
SET UP OVER NW WISCONSIN THIS EVENING WHICH DEVELOP AND INTENSIFY
A BAND OF RAIN OVER THAT AREA. THE UPPER LEVEL TROUGH OVER THE
NORTHERN PLAINS AND SOUTH CENTRAL CANADA WILL DEEPEN AND DEVELOP
INTO A WELL DEFINED UPPER LEVEL OVER SOUTHERN MANITOBA THIS
AFTERNOON AND CONTINUE DEEPENING AS IT APPROACHES NORTHERN
MANITOBA.
LATER TONIGHT AND EARLY MONDAY...THE COLD FRONT WILL FINISH
MOVING THROUGH THE FORECAST AREA. THE UPPER LEVEL LOW WILL
CONTINUE DEEPENING OVER NW ONTARIO. THE LOW/MID LEVEL
FRONTOGENETICAL BAND IN NW WISCONSIN SHOULD EXIT TO THE EAST BY
AROUND DAWN. TEMPERATURES WILL DROP INTO THE MIDDLE AND LOWER 30S
TONIGHT. THE SYNOPTIC LIFT FROM THE UPPER LEVEL LOW WILL LIKELY
RESULT IN LIGHT RAIN AND SNOW MOVING INTO THE NW FORECAST AREA.
LITTLE OF ANY SNOW ACCUMULATION IS EXPECTED SINCE MUCH OF IT
SHOULD MELT...EITHER ON IMPACT OR LATER IN THE MORNING.
MONDAY...IT WILL BE MUCH COOLER DAY WITH BLUSTERY NW WINDS.
SUSTAINED WINDS OF 10 TO 20 MPH WILL DEVELOP BY THE
AFTERNOON...AND THERE COULD BE GUSTS UP TO 30 MPH. THE 850 HPA
TEMPERATURES WILL BE ABOUT -5 TO -6 DEGREES CELSIUS. HEAVY CLOUD
COVER AND THE COOL NW FLOW WILL PREVENT HIGHS FROM GETTING MUCH
HIGHER THAN THE LOW TO MIDDLE 40S. THERE WILL BE INCREASING
CHANCES OF COLD RAIN SHOWERS AS THE UPPER LOW DEEPENS AND MOVES TO
JUST NORTH OF KOOCHICHING COUNTY.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 342 AM CDT SUN APR 19 2015
A DEEP AREA OF LOW PRESSURE WILL SETTLE SOUTHWARD INTO THE LAKE
SUPERIOR REGION MONDAY NIGHT AND TUESDAY. THE CLOSED H5 LOW WILL
REACH WESTERN LAKE SUPERIOR BY TUESDAY AFTERNOON. NUMEROUS
SHOWERS WILL ROTATE SOUTHWARD AROUND THE UPPER LOW...GENERALLY IN
THE FORM OF SNOW SHOWERS AT NIGHT AND RAIN OR SNOW SHOWERS DURING
THE DAY THROUGH THE MIDDLE OF THE WEEK. DEFINITELY COULD BE SOME
SLUSHY ACCUMULATION AT TIMES...ESPECIALLY IN THE NORTH. WOULD NOT
BE SURPRISED TO SEE A COUPLE EPISODES OF UP TO A COUPLE INCHES...
FOLLOWED BY SOME PARTIAL TO FULL MELTING DURING THE DAY. THIS
MASSIVE UPPER LEVEL TROUGH WILL EVENTUALLY LOSE ITS GRIP ON THE
AREA FROM THE MIDDLE TO THE END OF THE WORK WEEK. THE GEM AND TO
SOME EXTENT THE ECMWF ARE THE MOST AGGRESSIVE IN PUSHING THE
UPPER TROUGH EASTWARD THROUGH THE END OF THE WEEK...WITH THE GEM
BRINGING UPPER LEVEL RIDGING ALREADY INTO THE CWA BY 12Z FRIDAY.
THE GFS IS MUCH SLOWER AND DEEPER WITH THE UPPER LEVEL LOW.
STRONGLY FAVORING THE GEM/ECMWF SOLUTION...ESPECIALLY LATE IN THE
WEEK AND INTO THE WEEKEND. HIGH TEMPERATURES WILL REMAIN ON THE
COOL SIDE DURING THE WEEK...REACHING BACK INTO THE LOW TO MID 50S
ON THE WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1220 PM CDT SUN APR 19 2015
CONDITIONS VARIED FROM LIFR TO MVFR ACROSS THE NORTHLAND WITH
PERIODS OF RAIN/FOG/DRIZZLE MOVING THROUGH THE AREA. THESE
CONDITIONS WILL PERSIST THROUGH THE AFTERNOON INTO TONIGHT. THE
RAIN WILL BE MOST WIDESPREAD OVER EASTERN AREAS...ESPECIALLY
NORTHWEST WISCONSIN TONIGHT. SOUTHWEST AREAS INCLUDING KBRD MAY GO
VFR BRIEFLY LATER THIS EVENING...BUT AS COLDER AIR MOVES BACK IN
ON THE BACKSIDE OF THE LOW...LOWER CEILINGS WILL ONCE AGAIN RETURN.
TEMPERATURES MAY GET COLD ENOUGH FOR SOME SNOW OVER PORTIONS OF
NORTHERN MINNESOTA LATER TONIGHT. GUSTY WEST/NORTHWEST WINDS WILL
ALSO DEVELOP LATER IN THE PERIOD...ESPECIALLY ON MONDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 49 34 44 29 / 90 30 30 60
INL 49 32 40 28 / 100 40 60 60
BRD 56 35 43 31 / 80 20 40 40
HYR 58 37 46 30 / 90 80 30 60
ASX 58 37 47 32 / 90 80 20 60
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR
LSZ142>147.
&&
$$
UPDATE...GSF
SHORT TERM...GROCHOCINSKI
LONG TERM...DAP
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS DULUTH MN
949 AM CDT SUN APR 19 2015
.UPDATE...
ISSUED AT 945 AM CDT SUN APR 19 2015
RAIN WILL CONTINUE TO AFFECT THE FORECAST AREA THROUGH THE DAY.
HOWEVER...THERE WILL BE AN HOUR OR TWO WHEN NO RAIN IS OCCURRING
AND TRIED TO ACCOUNT FOR THIS IN THE FORECAST. KEPT THE MAX TEMPS
THE SAME FOR NOW...BUT WILL LOOK INTO LOWERING LATER TODAY. REST
OF THE FORECAST IN THE BALLPARK.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 342 AM CDT SUN APR 19 2015
THE FOCUS REMAINS ON THE RAIN TODAY AND TONIGHT. REFINED THE PCPN
CHANCES BY USING A BLEND OF THE RAP13 AND HRRR MODEL RUNS THROUGH
THIS MORNING SINCE THE TWO MODELS SEEM TO BE DOING PRETTY WELL
CAPTURING THE LOCATION OF THE CURRENT RAIN. DID NOT MAKE ANY
DRAMATIC CHANGES TO RAINFALL. OVERALL...MUCH OF THE FORECAST AREA
CAN EXPECT ABOUT 0.30 TO 0.75 INCHES OF RAINFALL THROUGH TONIGHT.
AT 330 AM...AN AREA OF LOW PRESSURE WAS OVER THE BORDER BETWEEN
SOUTH DAKOTA AND SW MINNESOTA. A FRONTAL BOUNDARY EXTENDED
NORTHWARD TO ANOTHER AREA OF LOW PRESSURE IN SOUTHERN MANITOBA.
THERE WAS AN UPPER LEVEL TROUGH OVER THE NORTHERN HIGH PLAINS AND
SASKATCHEWAN/MANITOBA DIGGING AND DEEPENING TOWARDS THE NORTHERN
PLAINS AND ONTARIO. A LARGE AREA OF RAIN WAS LIFTING TO NNE
THROUGH THE SOUTHERN TWO THIRDS OF THE FORECAST AREA. THIS RAIN
WAS ASSOCIATED WITH A BAND OF MID LEVEL FRONTOGENESIS AHEAD OF THE
LOW NEAR THE SD/MN BORDER. THERE WAS ADDITIONAL RAIN IN EASTERN
SOUTH DAKOTA AND NW MINNESOTA MOVING TO THE EAST IN THE WAKE OF
THE TROUGH BOUNDARY AND AHEAD OF THE UPPER LEVEL TO THE WEST. THE
NORTHLAND HAD CLOUDY SKIES WITH TEMPERATURES IN THE UPPER 30S TO
MIDDLE 40S. THE NORTHLAND HAD LIGHT EASTERLY TO SOUTHEASTERLY
WINDS.
THIS MORNING...THE SURFACE LOW NEAR THE SD/MN BORDER WILL LIFT NE
TO THE AITKIN AREA BY THIS AFTERNOON. THE SURFACE LOW IN SOUTHERN
MANITOBA WILL DIG TO THE SE. THE RAIN OVER THE FORECAST AREA EARLY
THIS MORNING WILL CONTINUE LIFTING TO THE NORTH WITH THE BAND OF
MID LEVEL FRONTOGENESIS. PARTS OF THE NORTHERN FORECAST COULD PICK
UP TO AROUND A HALF INCH OF RAIN THROUGH THIS MORNING. THE COLD
FRONT IN NORTH DAKOTA WILL BEGIN TO MOVE INTO THE WESTERN FORECAST
AREA LATE THIS MORNING.
THIS AFTERNOON AND EVENING...THE TWO LOWS WILL GRADUALLY MERGE
INTO ONE LOW OVER NW ONTARIO. CLOUDY AND COOL WEATHER IS EXPECTED
WITH HIGHS RANGING FROM THE UPPER 40S OVER THE NORTH TO THE 50S
OVER THE SOUTH. MOST OF THE AFTERNOON AND EVENING RAIN WILL BE
OVER THE EASTERN FORECAST AREA AHEAD OF THE EASTWARD ADVANCING
COLD FRONT. A DRY SLOT WILL MOVE INTO THE WESTERN FORECAST
AREA...AND THERE COULD BE PARTIAL CLEARING IN THE SW FORECAST
AREA. ALSO...A PROMINENT BAND OF LOW/MID LEVEL FRONTOGENESIS WILL
SET UP OVER NW WISCONSIN THIS EVENING WHICH DEVELOP AND INTENSIFY
A BAND OF RAIN OVER THAT AREA. THE UPPER LEVEL TROUGH OVER THE
NORTHERN PLAINS AND SOUTH CENTRAL CANADA WILL DEEPEN AND DEVELOP
INTO A WELL DEFINED UPPER LEVEL OVER SOUTHERN MANITOBA THIS
AFTERNOON AND CONTINUE DEEPENING AS IT APPROACHES NORTHERN
MANITOBA.
LATER TONIGHT AND EARLY MONDAY...THE COLD FRONT WILL FINISH
MOVING THROUGH THE FORECAST AREA. THE UPPER LEVEL LOW WILL
CONTINUE DEEPENING OVER NW ONTARIO. THE LOW/MID LEVEL
FRONTOGENETICAL BAND IN NW WISCONSIN SHOULD EXIT TO THE EAST BY
AROUND DAWN. TEMPERATURES WILL DROP INTO THE MIDDLE AND LOWER 30S
TONIGHT. THE SYNOPTIC LIFT FROM THE UPPER LEVEL LOW WILL LIKELY
RESULT IN LIGHT RAIN AND SNOW MOVING INTO THE NW FORECAST AREA.
LITTLE OF ANY SNOW ACCUMULATION IS EXPECTED SINCE MUCH OF IT
SHOULD MELT...EITHER ON IMPACT OR LATER IN THE MORNING.
MONDAY...IT WILL BE MUCH COOLER DAY WITH BLUSTERY NW WINDS.
SUSTAINED WINDS OF 10 TO 20 MPH WILL DEVELOP BY THE
AFTERNOON...AND THERE COULD BE GUSTS UP TO 30 MPH. THE 850 HPA
TEMPERATURES WILL BE ABOUT -5 TO -6 DEGREES CELSIUS. HEAVY CLOUD
COVER AND THE COOL NW FLOW WILL PREVENT HIGHS FROM GETTING MUCH
HIGHER THAN THE LOW TO MIDDLE 40S. THERE WILL BE INCREASING
CHANCES OF COLD RAIN SHOWERS AS THE UPPER LOW DEEPENS AND MOVES TO
JUST NORTH OF KOOCHICHING COUNTY.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 342 AM CDT SUN APR 19 2015
A DEEP AREA OF LOW PRESSURE WILL SETTLE SOUTHWARD INTO THE LAKE
SUPERIOR REGION MONDAY NIGHT AND TUESDAY. THE CLOSED H5 LOW WILL
REACH WESTERN LAKE SUPERIOR BY TUESDAY AFTERNOON. NUMEROUS
SHOWERS WILL ROTATE SOUTHWARD AROUND THE UPPER LOW...GENERALLY IN
THE FORM OF SNOW SHOWERS AT NIGHT AND RAIN OR SNOW SHOWERS DURING
THE DAY THROUGH THE MIDDLE OF THE WEEK. DEFINITELY COULD BE SOME
SLUSHY ACCUMULATION AT TIMES...ESPECIALLY IN THE NORTH. WOULD NOT
BE SURPRISED TO SEE A COUPLE EPISODES OF UP TO A COUPLE INCHES...
FOLLOWED BY SOME PARTIAL TO FULL MELTING DURING THE DAY. THIS
MASSIVE UPPER LEVEL TROUGH WILL EVENTUALLY LOSE ITS GRIP ON THE
AREA FROM THE MIDDLE TO THE END OF THE WORK WEEK. THE GEM AND TO
SOME EXTENT THE ECMWF ARE THE MOST AGGRESSIVE IN PUSHING THE
UPPER TROUGH EASTWARD THROUGH THE END OF THE WEEK...WITH THE GEM
BRINGING UPPER LEVEL RIDGING ALREADY INTO THE CWA BY 12Z FRIDAY.
THE GFS IS MUCH SLOWER AND DEEPER WITH THE UPPER LEVEL LOW.
STRONGLY FAVORING THE GEM/ECMWF SOLUTION...ESPECIALLY LATE IN THE
WEEK AND INTO THE WEEKEND. HIGH TEMPERATURES WILL REMAIN ON THE
COOL SIDE DURING THE WEEK...REACHING BACK INTO THE LOW TO MID 50S
ON THE WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 656 AM CDT SUN APR 19 2015
A LARGE AREA OF LOW PRESSURE WILL CONTINUE TO MOVE NORTHEAST INTO
THE NORTHLAND TODAY AND TONIGHT. ABUNDANT MOISTURE THROUGH THE
PLAINS WILL CONTINUE TO BRING AREAS OF LIGHT RAIN TODAY INTO
TONIGHT. CLOUD HEIGHTS ARE EXPECTED TO GRADUALLY DECREASE TO MVFR
OR EVEN IFR DURING THE MORNING...AND REMAIN THAT WAY THROUGH THE
AFTERNOON. SOME IMPROVEMENT IN CLOUD HEIGHTS WILL BE POSSIBLE FROM
THE WEST...AS SOMEWHAT DRIER AIR PUSHES EASTWARD BEHIND A COLD
FRONT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 49 34 44 29 / 90 30 30 60
INL 49 32 40 28 / 100 40 60 60
BRD 56 35 43 31 / 80 20 40 40
HYR 58 37 46 30 / 90 80 30 60
ASX 58 37 47 32 / 80 80 20 60
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR
LSZ142>147.
&&
$$
UPDATE...GSF
SHORT TERM...GROCHOCINSKI
LONG TERM...DAP
AVIATION...DAP
AREA FORECAST DISCUSSION
NWS DULUTH MN
701 AM CDT SUN APR 19 2015
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 342 AM CDT SUN APR 19 2015
THE FOCUS REMAINS ON THE RAIN TODAY AND TONIGHT. REFINED THE PCPN
CHANCES BY USING A BLEND OF THE RAP13 AND HRRR MODEL RUNS THROUGH
THIS MORNING SINCE THE TWO MODELS SEEM TO BE DOING PRETTY WELL
CAPTURING THE LOCATION OF THE CURRENT RAIN. DID NOT MAKE ANY
DRAMATIC CHANGES TO RAINFALL. OVERALL...MUCH OF THE FORECAST AREA
CAN EXPECT ABOUT 0.30 TO 0.75 INCHES OF RAINFALL THROUGH TONIGHT.
AT 330 AM...AN AREA OF LOW PRESSURE WAS OVER THE BORDER BETWEEN
SOUTH DAKOTA AND SW MINNESOTA. A FRONTAL BOUNDARY EXTENDED
NORTHWARD TO ANOTHER AREA OF LOW PRESSURE IN SOUTHERN MANITOBA.
THERE WAS AN UPPER LEVEL TROUGH OVER THE NORTHERN HIGH PLAINS AND
SASKATCHEWAN/MANITOBA DIGGING AND DEEPENING TOWARDS THE NORTHERN
PLAINS AND ONTARIO. A LARGE AREA OF RAIN WAS LIFTING TO NNE
THROUGH THE SOUTHERN TWO THIRDS OF THE FORECAST AREA. THIS RAIN
WAS ASSOCIATED WITH A BAND OF MID LEVEL FRONTOGENESIS AHEAD OF THE
LOW NEAR THE SD/MN BORDER. THERE WAS ADDITIONAL RAIN IN EASTERN
SOUTH DAKOTA AND NW MINNESOTA MOVING TO THE EAST IN THE WAKE OF
THE TROUGH BOUNDARY AND AHEAD OF THE UPPER LEVEL TO THE WEST. THE
NORTHLAND HAD CLOUDY SKIES WITH TEMPERATURES IN THE UPPER 30S TO
MIDDLE 40S. THE NORTHLAND HAD LIGHT EASTERLY TO SOUTHEASTERLY
WINDS.
THIS MORNING...THE SURFACE LOW NEAR THE SD/MN BORDER WILL LIFT NE
TO THE AITKIN AREA BY THIS AFTERNOON. THE SURFACE LOW IN SOUTHERN
MANITOBA WILL DIG TO THE SE. THE RAIN OVER THE FORECAST AREA EARLY
THIS MORNING WILL CONTINUE LIFTING TO THE NORTH WITH THE BAND OF
MID LEVEL FRONTOGENESIS. PARTS OF THE NORTHERN FORECAST COULD PICK
UP TO AROUND A HALF INCH OF RAIN THROUGH THIS MORNING. THE COLD
FRONT IN NORTH DAKOTA WILL BEGIN TO MOVE INTO THE WESTERN FORECAST
AREA LATE THIS MORNING.
THIS AFTERNOON AND EVENING...THE TWO LOWS WILL GRADUALLY MERGE
INTO ONE LOW OVER NW ONTARIO. CLOUDY AND COOL WEATHER IS EXPECTED
WITH HIGHS RANGING FROM THE UPPER 40S OVER THE NORTH TO THE 50S
OVER THE SOUTH. MOST OF THE AFTERNOON AND EVENING RAIN WILL BE
OVER THE EASTERN FORECAST AREA AHEAD OF THE EASTWARD ADVANCING
COLD FRONT. A DRY SLOT WILL MOVE INTO THE WESTERN FORECAST
AREA...AND THERE COULD BE PARTIAL CLEARING IN THE SW FORECAST
AREA. ALSO...A PROMINENT BAND OF LOW/MID LEVEL FRONTOGENESIS WILL
SET UP OVER NW WISCONSIN THIS EVENING WHICH DEVELOP AND INTENSIFY
A BAND OF RAIN OVER THAT AREA. THE UPPER LEVEL TROUGH OVER THE
NORTHERN PLAINS AND SOUTH CENTRAL CANADA WILL DEEPEN AND DEVELOP
INTO A WELL DEFINED UPPER LEVEL OVER SOUTHERN MANITOBA THIS
AFTERNOON AND CONTINUE DEEPENING AS IT APPROACHES NORTHERN
MANITOBA.
LATER TONIGHT AND EARLY MONDAY...THE COLD FRONT WILL FINISH
MOVING THROUGH THE FORECAST AREA. THE UPPER LEVEL LOW WILL
CONTINUE DEEPENING OVER NW ONTARIO. THE LOW/MID LEVEL
FRONTOGENETICAL BAND IN NW WISCONSIN SHOULD EXIT TO THE EAST BY
AROUND DAWN. TEMPERATURES WILL DROP INTO THE MIDDLE AND LOWER 30S
TONIGHT. THE SYNOPTIC LIFT FROM THE UPPER LEVEL LOW WILL LIKELY
RESULT IN LIGHT RAIN AND SNOW MOVING INTO THE NW FORECAST AREA.
LITTLE OF ANY SNOW ACCUMULATION IS EXPECTED SINCE MUCH OF IT
SHOULD MELT...EITHER ON IMPACT OR LATER IN THE MORNING.
MONDAY...IT WILL BE MUCH COOLER DAY WITH BLUSTERY NW WINDS.
SUSTAINED WINDS OF 10 TO 20 MPH WILL DEVELOP BY THE
AFTERNOON...AND THERE COULD BE GUSTS UP TO 30 MPH. THE 850 HPA
TEMPERATURES WILL BE ABOUT -5 TO -6 DEGREES CELSIUS. HEAVY CLOUD
COVER AND THE COOL NW FLOW WILL PREVENT HIGHS FROM GETTING MUCH
HIGHER THAN THE LOW TO MIDDLE 40S. THERE WILL BE INCREASING
CHANCES OF COLD RAIN SHOWERS AS THE UPPER LOW DEEPENS AND MOVES TO
JUST NORTH OF KOOCHICHING COUNTY.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 342 AM CDT SUN APR 19 2015
A DEEP AREA OF LOW PRESSURE WILL SETTLE SOUTHWARD INTO THE LAKE
SUPERIOR REGION MONDAY NIGHT AND TUESDAY. THE CLOSED H5 LOW WILL
REACH WESTERN LAKE SUPERIOR BY TUESDAY AFTERNOON. NUMEROUS
SHOWERS WILL ROTATE SOUTHWARD AROUND THE UPPER LOW...GENERALLY IN
THE FORM OF SNOW SHOWERS AT NIGHT AND RAIN OR SNOW SHOWERS DURING
THE DAY THROUGH THE MIDDLE OF THE WEEK. DEFINITELY COULD BE SOME
SLUSHY ACCUMULATION AT TIMES...ESPECIALLY IN THE NORTH. WOULD NOT
BE SURPRISED TO SEE A COUPLE EPISODES OF UP TO A COUPLE INCHES...
FOLLOWED BY SOME PARTIAL TO FULL MELTING DURING THE DAY. THIS
MASSIVE UPPER LEVEL TROUGH WILL EVENTUALLY LOSE ITS GRIP ON THE
AREA FROM THE MIDDLE TO THE END OF THE WORK WEEK. THE GEM AND TO
SOME EXTENT THE ECMWF ARE THE MOST AGGRESSIVE IN PUSHING THE
UPPER TROUGH EASTWARD THROUGH THE END OF THE WEEK...WITH THE GEM
BRINGING UPPER LEVEL RIDGING ALREADY INTO THE CWA BY 12Z FRIDAY.
THE GFS IS MUCH SLOWER AND DEEPER WITH THE UPPER LEVEL LOW.
STRONGLY FAVORING THE GEM/ECMWF SOLUTION...ESPECIALLY LATE IN THE
WEEK AND INTO THE WEEKEND. HIGH TEMPERATURES WILL REMAIN ON THE
COOL SIDE DURING THE WEEK...REACHING BACK INTO THE LOW TO MID 50S
ON THE WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 656 AM CDT SUN APR 19 2015
A LARGE AREA OF LOW PRESSURE WILL CONTINUE TO MOVE NORTHEAST INTO
THE NORTHLAND TODAY AND TONIGHT. ABUNDANT MOISTURE THROUGH THE
PLAINS WILL CONTINUE TO BRING AREAS OF LIGHT RAIN TODAY INTO
TONIGHT. CLOUD HEIGHTS ARE EXPECTED TO GRADUALLY DECREASE TO MVFR
OR EVEN IFR DURING THE MORNING...AND REMAIN THAT WAY THROUGH THE
AFTERNOON. SOME IMPROVEMENT IN CLOUD HEIGHTS WILL BE POSSIBLE FROM
THE WEST...AS SOMEWHAT DRIER AIR PUSHES EASTWARD BEHIND A COLD
FRONT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 49 34 44 29 / 80 30 30 60
INL 49 32 40 28 / 90 40 60 60
BRD 56 35 43 31 / 80 20 40 40
HYR 58 37 46 30 / 80 80 30 60
ASX 58 37 47 32 / 80 80 20 60
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR
LSZ142>147.
&&
$$
SHORT TERM...GROCHOCINSKI
LONG TERM...DAP
AVIATION...DAP
AREA FORECAST DISCUSSION
NWS DULUTH MN
342 AM CDT SUN APR 19 2015
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 342 AM CDT SUN APR 19 2015
THE FOCUS REMAINS ON THE RAIN TODAY AND TONIGHT. REFINED THE PCPN
CHANCES BY USING A BLEND OF THE RAP13 AND HRRR MODEL RUNS THROUGH
THIS MORNING SINCE THE TWO MODELS SEEM TO BE DOING PRETTY WELL
CAPTURING THE LOCATION OF THE CURRENT RAIN. DID NOT MAKE ANY
DRAMATIC CHANGES TO RAINFALL. OVERALL...MUCH OF THE FORECAST AREA
CAN EXPECT ABOUT 0.30 TO 0.75 INCHES OF RAINFALL THROUGH TONIGHT.
AT 330 AM...AN AREA OF LOW PRESSURE WAS OVER THE BORDER BETWEEN
SOUTH DAKOTA AND SW MINNESOTA. A FRONTAL BOUNDARY EXTENDED
NORTHWARD TO ANOTHER AREA OF LOW PRESSURE IN SOUTHERN MANITOBA.
THERE WAS AN UPPER LEVEL TROUGH OVER THE NORTHERN HIGH PLAINS AND
SASKATCHEWAN/MANITOBA DIGGING AND DEEPENING TOWARDS THE NORTHERN
PLAINS AND ONTARIO. A LARGE AREA OF RAIN WAS LIFTING TO NNE
THROUGH THE SOUTHERN TWO THIRDS OF THE FORECAST AREA. THIS RAIN
WAS ASSOCIATED WITH A BAND OF MID LEVEL FRONTOGENESIS AHEAD OF THE
LOW NEAR THE SD/MN BORDER. THERE WAS ADDITIONAL RAIN IN EASTERN
SOUTH DAKOTA AND NW MINNESOTA MOVING TO THE EAST IN THE WAKE OF
THE TROUGH BOUNDARY AND AHEAD OF THE UPPER LEVEL TO THE WEST. THE
NORTHLAND HAD CLOUDY SKIES WITH TEMPERATURES IN THE UPPER 30S TO
MIDDLE 40S. THE NORTHLAND HAD LIGHT EASTERLY TO SOUTHEASTERLY
WINDS.
THIS MORNING...THE SURFACE LOW NEAR THE SD/MN BORDER WILL LIFT NE
TO THE AITKIN AREA BY THIS AFTERNOON. THE SURFACE LOW IN SOUTHERN
MANITOBA WILL DIG TO THE SE. THE RAIN OVER THE FORECAST AREA EARLY
THIS MORNING WILL CONTINUE LIFTING TO THE NORTH WITH THE BAND OF
MID LEVEL FRONTOGENESIS. PARTS OF THE NORTHERN FORECAST COULD PICK
UP TO AROUND A HALF INCH OF RAIN THROUGH THIS MORNING. THE COLD
FRONT IN NORTH DAKOTA WILL BEGIN TO MOVE INTO THE WESTERN FORECAST
AREA LATE THIS MORNING.
THIS AFTERNOON AND EVENING...THE TWO LOWS WILL GRADUALLY MERGE
INTO ONE LOW OVER NW ONTARIO. CLOUDY AND COOL WEATHER IS EXPECTED
WITH HIGHS RANGING FROM THE UPPER 40S OVER THE NORTH TO THE 50S
OVER THE SOUTH. MOST OF THE AFTERNOON AND EVENING RAIN WILL BE
OVER THE EASTERN FORECAST AREA AHEAD OF THE EASTWARD ADVANCING
COLD FRONT. A DRY SLOT WILL MOVE INTO THE WESTERN FORECAST
AREA...AND THERE COULD BE PARTIAL CLEARING IN THE SW FORECAST
AREA. ALSO...A PROMINENT BAND OF LOW/MID LEVEL FRONTOGENESIS WILL
SET UP OVER NW WISCONSIN THIS EVENING WHICH DEVELOP AND INTENSIFY
A BAND OF RAIN OVER THAT AREA. THE UPPER LEVEL TROUGH OVER THE
NORTHERN PLAINS AND SOUTH CENTRAL CANADA WILL DEEPEN AND DEVELOP
INTO A WELL DEFINED UPPER LEVEL OVER SOUTHERN MANITOBA THIS
AFTERNOON AND CONTINUE DEEPENING AS IT APPROACHES NORTHERN
MANITOBA.
LATER TONIGHT AND EARLY MONDAY...THE COLD FRONT WILL FINISH
MOVING THROUGH THE FORECAST AREA. THE UPPER LEVEL LOW WILL
CONTINUE DEEPENING OVER NW ONTARIO. THE LOW/MID LEVEL
FRONTOGENETICAL BAND IN NW WISCONSIN SHOULD EXIT TO THE EAST BY
AROUND DAWN. TEMPERATURES WILL DROP INTO THE MIDDLE AND LOWER 30S
TONIGHT. THE SYNOPTIC LIFT FROM THE UPPER LEVEL LOW WILL LIKELY
RESULT IN LIGHT RAIN AND SNOW MOVING INTO THE NW FORECAST AREA.
LITTLE OF ANY SNOW ACCUMULATION IS EXPECTED SINCE MUCH OF IT
SHOULD MELT...EITHER ON IMPACT OR LATER IN THE MORNING.
MONDAY...IT WILL BE MUCH COOLER DAY WITH BLUSTERY NW WINDS.
SUSTAINED WINDS OF 10 TO 20 MPH WILL DEVELOP BY THE
AFTERNOON...AND THERE COULD BE GUSTS UP TO 30 MPH. THE 850 HPA
TEMPERATURES WILL BE ABOUT -5 TO -6 DEGREES CELSIUS. HEAVY CLOUD
COVER AND THE COOL NW FLOW WILL PREVENT HIGHS FROM GETTING MUCH
HIGHER THAN THE LOW TO MIDDLE 40S. THERE WILL BE INCREASING
CHANCES OF COLD RAIN SHOWERS AS THE UPPER LOW DEEPENS AND MOVES TO
JUST NORTH OF KOOCHICHING COUNTY.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 342 AM CDT SUN APR 19 2015
A DEEP AREA OF LOW PRESSURE WILL SETTLE SOUTHWARD INTO THE LAKE
SUPERIOR REGION MONDAY NIGHT AND TUESDAY. THE CLOSED H5 LOW WILL
REACH WESTERN LAKE SUPERIOR BY TUESDAY AFTERNOON. NUMEROUS
SHOWERS WILL ROTATE SOUTHWARD AROUND THE UPPER LOW...GENERALLY IN
THE FORM OF SNOW SHOWERS AT NIGHT AND RAIN OR SNOW SHOWERS DURING
THE DAY THROUGH THE MIDDLE OF THE WEEK. DEFINITELY COULD BE SOME
SLUSHY ACCUMULATION AT TIMES...ESPECIALLY IN THE NORTH. WOULD NOT
BE SURPRISED TO SEE A COUPLE EPISODES OF UP TO A COUPLE INCHES...
FOLLOWED BY SOME PARTIAL TO FULL MELTING DURING THE DAY. THIS
MASSIVE UPPER LEVEL TROUGH WILL EVENTUALLY LOSE ITS GRIP ON THE
AREA FROM THE MIDDLE TO THE END OF THE WORK WEEK. THE GEM AND TO
SOME EXTENT THE ECMWF ARE THE MOST AGGRESSIVE IN PUSHING THE
UPPER TROUGH EASTWARD THROUGH THE END OF THE WEEK...WITH THE GEM
BRINGING UPPER LEVEL RIDGING ALREADY INTO THE CWA BY 12Z FRIDAY.
THE GFS IS MUCH SLOWER AND DEEPER WITH THE UPPER LEVEL LOW.
STRONGLY FAVORING THE GEM/ECMWF SOLUTION...ESPECIALLY LATE IN THE
WEEK AND INTO THE WEEKEND. HIGH TEMPERATURES WILL REMAIN ON THE
COOL SIDE DURING THE WEEK...REACHING BACK INTO THE LOW TO MID 50S
ON THE WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 101 AM CDT SUN APR 19 2015
AN AREA OF LOW PRESSURE WILL SPREAD GRADUALLY LOWERING CLOUDS AND
RAINFALL INTO THE AREA FROM THE SOUTHWEST THROUGH 10Z...WITH
CEILINGS SLOWLY LOWERING TO IFR WITH VISIBILITIES TO MVFR IN
LIGHT RAIN. THIS WILL CONTINUE THROUGH APPROXIMATELY 18Z BEFORE
SLOWLY DIMINISHING AGAIN FROM SOUTHWEST TO NORTHEAST. CEILINGS
EXPECTED TO REMAIN MVFR-IFR UNTIL AFTER LOW PASSAGE AND WINDS
TURN TO NORTHWEST...ALLOWING CEILINGS AND VISIBILITIES TO
GRADUALLY RETURN TO MVFR...THEN VFR BY 02Z THIS EVENING.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 49 36 42 30 / 90 40 60 50
INL 49 32 40 27 / 100 50 70 60
BRD 55 36 42 30 / 90 20 60 40
HYR 56 37 44 31 / 90 60 50 50
ASX 56 38 45 32 / 80 60 50 60
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 10 AM CDT THIS MORNING FOR LSZ142>147.
&&
$$
SHORT TERM...GROCHOCINSKI
LONG TERM...DAP
AVIATION...DAP
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1239 PM CDT Sun Apr 19 2015
.UPDATE...
Issued at 723 AM CDT SUN APR 19 2015
Made major adjustments to the forecast. Lowered PoPs considerably for
the rest of the morning south and west of a h7 vorticity lobe that
defines the back edge of showers over northern and into central
MO...roughly along an arc from St. Joseph to Sedalia. Trend of the
HRRR, RUC and even the NAM supports the above scenario. Convective
cluster over north central OK may graze the far southern counties
this afternoon so likely PoPs this area seems reasonable. So, for a
good portion of today many areas will see little in the way of
measurable rainfall. Still believe we`ll see a band of stratiform
type rain tied to the post-frontal baroclinic zone/deformation zone
that will slide ese across the CWA from late afternoon through this
evening.
&&
.SHORT TERM...(Today through Tuesday)
Issued at 407 AM CDT SUN APR 19 2015
Today - Tonight:
Today`s weather will be governed by the transition of an upper level
closed low to an open wave. Latest water vapor satellite imagery
shows the closed upper low has now shifted east into west central KS
early this morning. A shortwave trough digging into the Northern
High Plains will push this feature and its associated convection
through the CWA today with the rain ending from west to east this
evening.
Scattered showers and isolated thunderstorms will accompany a
couple mid level vorticity lobes as they rotate northeast across KS
and MO. No severe storms are expected today as less than impressive
MUCAPEs in the 400-800 J/kg range and bulk shear values around 25kts
will limit the strength of the storms. Like yesterday a few cells
could produce small hail during peak heating. Temperatures will
again be negatively impacted by the convection and cloud cover. A
more organized band of stratiform rain tied to post-frontal
frontogenesis and an elongated deformation zone overspreads the
region during the evening hours.
Monday - Tuesday:
The Northern Plains upper trough will gradually sharpen south and
shift east on Monday with strong subsidence spilling southeast on
the backside of the trough. Clearing skies will help offset cold air
advection yielding slightly below average temperatures both days.
The operational models are showing similar weak signals on Tuesday
that we`ll need to start considering the chance of some shower
activity. The models generate a series of weak strung out vorticity
lobes stretching southeast from NE through MO. Moisture will be the
main limiting factor so if any rain forms it will be light and
scattered.
.LONG TERM...(Wednesday through Saturday)
Issued at 407 AM CDT SUN APR 19 2015
Slightly below normal temperatures will stretch through the latter
half of the week as deep low pressure very slowly transitions SE
across the Great Lakes, and northwest flow aloft ushers cooler
temperatures into the region. At the same time a surface boundary
will drift southward through Wednesday, leaving the forecast area in
north to northeast surface flow and also helping to keep highs in
the lower to mid 60s. A few light showers and isolated storms are
possible over the southern tier of the CWA Wednesday and Wednesday
night as the front heads south, then a period of drier conditions is
expected on the north side of the boundary Thursday.
Southerly surface flow will eventually return by the end of the work
week ahead of a shortwave trough that will eject out of the desert
southwest and into the Plains by Friday. Widely scattered showers
and storms are possible as early as Friday afternoon, but are more
likely Friday night as the upper trough passes over the CWA. Timing
of this system is still a bit uncertain, and the probability of any
embedded storms will depend on how quickly southerly flow and low-
level moisture return to the region ahead of the shortwave trough.
At this time, the southern track of the associated surface low and
the environment in place ahead of the system suggests that the
potential for strong storms is very low. The clouds and any rain
associated with the system will keep temperatures down despite the
transition to southerly flow, so have kept highs mainly in the lower
60s through the end of the work week and into the weekend. Current
model trends show the wet weather clearing out by Saturday evening
and a dry Sunday, but will have to watch the potential for Friday`s
system to slow down and impact the coming weekend.
&&
.AVIATION...(For the 18Z TAFS through 18Z Monday Afternoon)
Issued at 1237 PM CDT SUN APR 19 2015
Rain will stay out of the terminals for the next few hours, but by
this evening rain, with some embedded thunder will move through the
terminals. Expect the bulk of the rainy activity to only last a
couple hours, with perhaps a few lingering hours of low ceilings and
drizzle or very light rain. Expect winds to be gusty all night, but
they should really pick up out of the NW by mid morning on Monday.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
UPDATE...MJ
SHORT TERM...MJ
LONG TERM...Laflin
AVIATION...Leighton
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
727 AM CDT Sun Apr 19 2015
.UPDATE...
Issued at 723 AM CDT SUN APR 19 2015
Made major adjustments to the forecast. Lowered PoPs considerably for
the rest of the morning south and west of a h7 vorticity lobe that
defines the back edge of showers over northern and into central
MO...roughly along an arc from St. Joseph to Sedalia. Trend of the
HRRR, RUC and even the NAM supports the above scenario. Convective
cluster over north central OK may graze the far southern counties
this afternoon so likely PoPs this area seems reasonable. So, for a
good portion of today many areas will see little in the way of
measurable rainfall. Still believe we`ll see a band of stratiform
type rain tied to the post-frontal baroclinic zone/deformation zone
that will slide ese across the CWA from late afternoon through this
evening.
&&
.SHORT TERM...(Today through Tuesday)
Issued at 407 AM CDT SUN APR 19 2015
Today - Tonight:
Today`s weather will be governed by the transition of an upper level
closed low to an open wave. Latest water vapor satellite imagery
shows the closed upper low has now shifted east into west central KS
early this morning. A shortwave trough digging into the Northern
High Plains will push this feature and its associated convection
through the CWA today with the rain ending from west to east this
evening.
Scattered showers and isolated thunderstorms will accompany a
couple mid level vorticity lobes as they rotate northeast across KS
and MO. No severe storms are expected today as less than impressive
MUCAPEs in the 400-800 J/kg range and bulk shear values around 25kts
will limit the strength of the storms. Like yesterday a few cells
could produce small hail during peak heating. Temperatures will
again be negatively impacted by the convection and cloud cover. A
more organized band of stratiform rain tied to post-frontal
frontogenesis and an elongated deformation zone overspreads the
region during the evening hours.
Monday - Tuesday:
The Northern Plains upper trough will gradually sharpen south and
shift east on Monday with strong subsidence spilling southeast on
the backside of the trough. Clearing skies will help offset cold air
advection yielding slightly below average temperatures both days.
The operational models are showing similar weak signals on Tuesday
that we`ll need to start considering the chance of some shower
activity. The models generate a series of weak strung out vorticity
lobes stretching southeast from NE through MO. Moisture will be the
main limiting factor so if any rain forms it will be light and
scattered.
.LONG TERM...(Wednesday through Saturday)
Issued at 407 AM CDT SUN APR 19 2015
Slightly below normal temperatures will stretch through the latter
half of the week as deep low pressure very slowly transitions SE
across the Great Lakes, and northwest flow aloft ushers cooler
temperatures into the region. At the same time a surface boundary
will drift southward through Wednesday, leaving the forecast area in
north to northeast surface flow and also helping to keep highs in
the lower to mid 60s. A few light showers and isolated storms are
possible over the southern tier of the CWA Wednesday and Wednesday
night as the front heads south, then a period of drier conditions is
expected on the north side of the boundary Thursday.
Southerly surface flow will eventually return by the end of the work
week ahead of a shortwave trough that will eject out of the desert
southwest and into the Plains by Friday. Widely scattered showers
and storms are possible as early as Friday afternoon, but are more
likely Friday night as the upper trough passes over the CWA. Timing
of this system is still a bit uncertain, and the probability of any
embedded storms will depend on how quickly southerly flow and low-
level moisture return to the region ahead of the shortwave trough.
At this time, the southern track of the associated surface low and
the environment in place ahead of the system suggests that the
potential for strong storms is very low. The clouds and any rain
associated with the system will keep temperatures down despite the
transition to southerly flow, so have kept highs mainly in the lower
60s through the end of the work week and into the weekend. Current
model trends show the wet weather clearing out by Saturday evening
and a dry Sunday, but will have to watch the potential for Friday`s
system to slow down and impact the coming weekend.
&&
.AVIATION...(For the 12Z TAFS through 12Z Monday Morning)
Issued at 635 AM CDT SUN APR 19 2015
Scattered showers and a few storms lifting north through northern MO
may define the last of the rain till late this afternoon and evening
when deformation band of stratiform type rain moves in. The onset of
gusty northwest winds will likely signal when this band will move in
with its MVFR ceilings. Till then think much of the day will only see
spotty hit/miss type showers. Thunderstorm risk looks minimal.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
UPDATE...MJ
SHORT TERM...MJ
LONG TERM...Laflin
AVIATION...MJ
AREA FORECAST DISCUSSION...UPDATED
NWS SPRINGFIELD MO
1201 AM CDT Sun Apr 19 2015
...Updated Aviation Section...
.UPDATE...
Issued at 703 PM CDT SAT APR 18 2015
Forecast will be updated shortly to account for short term trends
from satellite/radar as well as to account for expected convective
trends heading into the overnight hours.
Over the past few hours, we have seen clearing across western
portions of the area. This clearing will likely be short lived as
mid/high level clouds increase from the west from convective
exhaust. That said, this area did see a soaking rain this morning
and dewpoints remain relatively high compared to expected lows. As
a result, will include a mention of patchy fog and keep an eye on
localized dense fog potential in places where skies can remain
clear for a longer period of time.
In addition, PoPs have been updated for the next 12 or so hours.
The western half of the area will likely see little in the way of
rain chances this evening. Chances over the eastern half look to
remain in the solid chance range giving on again/off again showers
and isolated thunder. HRRR and other short range models continue
to indicate rain chances increasing across south central Missouri
and the eastern Ozarks from late this evening into the overnight
hours. In addition, remnant convection from KS/OK complexes will
enter from the west, with rain chances steadily increasing
across extreme southeastern Kansas and western Missouri.
Interestingly, the Highway 65 corridor will likely be between
these two areas of activity and PoPs are lowest in this area for
tonight.
Taking a peak at tomorrow`s severe weather potential. There
remains some question as to just how much instability we will be
able to generate as decaying convection continues to spread in
from the west during the morning hours. The main upper trough will
not arrive until later in the day, bringing and increase in deep
layer shear. However, models struggle to bring much more that
500-1000 J/kg of most unstable CAPE into the southern half of the
area. By far the better chances for severe convection will be to
our south and southeast. Obviously this is close enough to keep a
close eye on trends and we will see what the 00z suite of models
have in store for the area.
&&
.SHORT TERM...(This Evening through Sunday Night)
Issued at 315 PM CDT SAT APR 18 2015
The coverage of showers and thunderstorms continued to decrease into
the afternoon. However a band of scattered showers and storms persisted
along a 925-850 MB convergence axis that stretched north to south
east of the Highway 65 corridor and in advance of a mid level vorticity
lobe lifting northeast across the area. Expect convection through
early evening to be focused along and ahead of these features
across south central Missouri. This 925-850 MB convergence axis
may become the focus for additional development later tonight
across the eastern Ozarks as another vorticity lobe lifts
northeast toward southeastern Missouri. Coverage of precipitation
will remain more isolated elsewhere much of tonight. However there
may be increase in convection from the west into southeastern
Kansas into far southwest late tonight as convection across the
Plains shifts eastward.
The closed upper level low now over eastern Colorado will open up
and track eastward toward Missouri on Sunday. Expect the coverage
of convection to increase Sunday as synoptic scale lift increases
with the aide of an increasingly diffluent upper flow and the
approach of vorticity maxima.
Deep layer shear will increase Sunday as the mid level flow
strengthens and lapse rates steepen as temperatures aloft cool in
response to the approaching upper level trough.
The question is the extent of instability that will develop. The
potential for ongoing convection and cloud cover may limit surface
heating and resulting instability. However if sufficient
instability can be realized then ingredients would be in place for
at least a few severe storms.
At this time the greatest potential for strong to severe storms
will be across far southern Missouri or generally along and south
of Interstate 44. The risk for severe weather could decrease or
increase depending on the amount of destabilization. The primary
risks with any severe storms that can develop would damaging winds
and large hail.
With some areas already receiving moderate to heavy rainfall the
past couple of days...the risk for localized flooding will have to
be monitored particularly across far southwestern Missouri.
Showers and some thunder will linger into Sunday night as the
upper level trough and associated cold front track across the
area.
.LONG TERM...(Monday through Saturday)
Issued at 315 PM CDT SAT APR 18 2015
Much cooler weather will prevail heading into early next week as
an upper level trough digs into the Great Lakes and maintains a
northwesterly flow aloft across the region. This cooler weather
will persist most of next week. Weather conditions could also be
rather unsettled as disturbances slide southeastward around the
periphery of the upper trough. This will bring intervals clouds and
the possibility of showers and thunderstorms at times mid through
late week. However this activity is expected to be spotty in
nature.
Temperatures could fall into the upper 30s Monday night. Frost is
not expected at this time but this potential should be monitored.
&&
.AVIATION...(For the 06Z TAFS through 06Z Sunday Night)
Issued at 1201 AM CDT SUN APR 19 2015
Challenging forecast for area aerodromes as convection will fester
around the region the rest of tonight, and regenerate Sunday
afternoon. Decaying bands of showers/storms will attempt to enter
from the west in the coming hours, however a lack of instability
will likely result in this activity losing its punch and gradually
dissipating as it moves through the JLN aerodrome. Earlier
clearing at SGF/BBG is being replaced by mid/high level clouds.
There is patchy ground fog around, but this may not become too
widespread. Bouts of MVFR visibility are expected, with an outside
chance of IFR at BBG. Main storm system will move into area Sunday
afternoon/evening. Another round of showers/storms will be
associated with this system, which will begin to exit to the east
by the end of the TAF cycle. Winds will be light into the daylight
hours of Sunday morning, becoming southwesterly during the day and
shift to the northwest heading into the evening.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
UPDATE...Gagan
SHORT TERM...Foster
LONG TERM...Foster
AVIATION...Gagan
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
833 PM MDT MON APR 20 2015
.UPDATE...
NO CHANGES NEED TO THE GOING FORECAST. RADAR SHOWED WEAK ECHOES
OVER NE MT...AHEAD OF THE BACK DOOR COLD FRONT THAT WAS OVER S
CENTRAL SASKATCHEWAN INTO NW ND...THIS EVENING. THE ECHOES
APPEARED TO BE MID CLOUD COVER BASED ON SURFACE OBSERVATIONS THAT
HAD TEMPERATURE/DEWPOINT SPREADS ON THE ORDER OF 30 DEGREES.
SATELLITE SHOWED THE CLOUDS OVER NE MT AS WELL AS OTHER MID LEVEL
CLOUDS OVER THE FORECAST AREA. WEBCAMS SHOWED A COUPLE OF SHOWERS
EARLIER IN THE EVENING...BUT THESE HAVE DISSIPATED WITH LOSS OF
SOLAR INSOLATION. THE BACK DOOR FRONT WAS FORECAST TO MOVE THROUGH
NE MT OVERNIGHT. NEW WRF AND LAST COUPLE OF HRRR RUNS WERE DRY
OVERNIGHT. THE DRY FORECAST WAS IN GOOD SHAPE BASED ON THE ABOVE.
WEAK ENERGY SPILLING OVER THE UPPER RIDGE ANCHORED OVER THE
PACIFIC NW INTO W CANADA...WILL SUPPORT PARTLY CLOUDY SKIES
ACROSS THE AREA OVERNIGHT. LIFT AHEAD OF THE BACK DOOR FRONT WILL
SUPPORT MID CLOUDS OVER THE AREA AHEAD AS WELL. SKY GRIDS
REFLECTED THIS WELL.
850 MB TEMPERATURES WILL REMAIN FAIRLY STEADY AROUND +8 DEGREES C
OVERNIGHT AND FORECAST AREA WILL BE IN A PREFRONTAL ENVIRONMENT.
BASED ON THE ABOVE...AND RECENT TRENDS OF LOWS VERIFYING AT OR
BELOW GUIDANCE...THE FORECAST MINS LOOKED REASONABLE. RH AND WINDS
WERE ALSO ON TRACK.
DRY LOW-LEVELS WILL LIMIT SHOWERS WITH THE FRONT ON TUE. GOING
FORECAST HAD POPS RESTRICTED TO THE HIGHER ELEVATIONS WHICH SEEMED
REASONABLE. ARTHUR
&&
.SHORT TERM...VALID FOR TUE AND WED...
THE SHORT TERM IS DOMINATED BY THE RIDGE OVER THE INTERMOUNTAIN
WEST SLOWLY SHIFTING TO THE EAST. THIS WILL KEEP THE AREA MAINLY
IN CYCLONIC NORTHWEST FLOW. SEVERAL WEAK BANDS OF ENERGY WILL
MOVE THROUGH THE AREA...MAINLY OVER THE MOUNTAINS. HAVE CONTINUED
THE SLIGHT CHANCES OF PRECIP OVER THE MOUNTAINS THROUGH THE
PERIOD. TOMORROW WILL SEE WARMER TEMPERATURES APPROACHING 70
DEGREES. WINDS WILL BEGIN TO SHIFT MORE EASTERLY TOMORROW
AFTERNOON WHICH WILL HELP TO BRING MORE MOISTURE INTO THE AREA.
WINDS WILL BE OUT OF THE EAST THROUGH MUCH OF THE DAY ON
WEDNESDAY...SO EXPECTING RAIN CHANCES TO BEGIN TO INCREASE...WITH
CHANCES OVER THE MOUNTAINS AND FOOTHILLS...AND A SLIGHT CHANCE OUT
ONTO THE PLAINS. REIMER
.LONG TERM...VALID FOR THU...FRI...SAT...SUN...MON...
THE FORECAST AREA WILL STILL BE IN A BLOCKING PATTERN THROUGH THE
FORECAST PERIOD. THIS BLOCKING PATTERN INVOLVES A DEEP UPPER LOW
OVER THE GREAT LAKES AREA AND A DEEPENING TROUGH OFF THE PACIFIC
NORTHWEST. MONTANA AND NORTHERN WYOMING WILL BE IN BETWEEN THESE
SYSTEMS AND SUBJECT TO A WEAK RIDGING PATTERN ON THURSDAY. THIS
WEAK RIDGING BREAKS DOWN ON FRIDAY AS THE EASTERN TROUGH SHIFTS
EAST A BIT. THIS BREAK DOWN WILL ALLOW WEAK ENERGY TO KICK OUT OF
THE WESTERN TROUGH AND SLIDE ACROSS THE FORECAST AREA FRIDAY
THROUGH NEXT WEEKEND. EASTERLY LOW LEVEL FLOW WILL KEEP SOME LOW
LEVEL MOISTURE AVAILABLE AND WILL THUS KEEP POPS GOING. THE BEST
CHANCE OF SHOWERS SHOULD BE SATURDAY AS A DEEP TROUGH AND SURFACE
LOW MOVES ACROSS THE AREA. LOW LEVEL EASTERLY WINDS WILL KEEP
TEMPERATURES TO SLIGHTLY ABOVE SEASONAL VALUES. TWH
&&
.AVIATION...
VFR CONDITIONS WILL BE OVER THE AREA TONIGHT THROUGH TUE EVENING.
LOCALIZED MOUNTAIN OBSCURATIONS WILL OCCUR THROUGH TUE EVENING.
ARTHUR
&&
.PRELIMINARY POINT TEMP/POPS...
TUE WED THU FRI SAT SUN MON
-----------------------------------------------------------
BIL 038/066 040/072 042/070 041/065 043/063 040/067 042/068
01/B 10/B 12/W 22/W 33/W 32/W 21/B
LVM 034/069 037/074 038/070 038/063 038/062 035/064 037/066
01/B 21/B 33/W 34/W 43/W 32/W 22/W
HDN 034/067 036/073 038/072 037/066 038/066 036/070 036/071
01/B 10/B 12/W 22/W 33/W 32/W 21/B
MLS 032/063 034/069 036/068 038/066 039/066 038/068 038/069
00/U 10/B 01/B 22/W 33/W 32/W 21/B
4BQ 031/064 033/069 036/068 038/064 039/064 037/068 036/070
00/B 10/B 01/B 23/W 33/W 42/W 21/B
BHK 028/057 029/063 031/063 034/062 035/061 034/066 033/064
00/U 10/B 00/N 23/W 33/W 42/W 21/B
SHR 028/064 035/069 037/069 037/062 038/063 036/065 036/068
01/B 10/B 13/W 33/W 34/W 32/W 21/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
129 PM CDT SUN APR 19 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 313 AM CDT SUN APR 19 2015
THE UPPER LOW WHICH PRODUCED UP TO 52 INCHES OF SNOW IN COLORADO
HAS DRIFTED EAST INTO WRN KS THIS MORNING. RAIN AND THUNDERSTORMS
ARE FALLING UNDER THE LOW. A DEFORMATION ZONE OF RAIN AND
ISOLATED THUNDERSTORMS IS WEAKENING ACROSS NCNTL AND SWRN NEB
THIS MORNING. THE MODELS DRAG THIS AREA OF RAIN SOUTH AND OUT OF
THE FORECAST AREA BY 15Z-18Z. A STRONG COLD FRONT WITH SCATTERED
SHOWERS WILL DROP THROUGH THE FCST AREA THIS MORNING SETTING UP A
WINDY AND COOL DAY. NORTHWEST WINDS WILL INCREASE TO 20 TO 30 MPH
WITH GUSTS TO 40 MPH. THESE WINDS ARE ALREADY UNDERWAY IN THE
PANHANDLE.
THE STRONG WINDS BEND AROUND THE BLACK HILLS PRODUCING
CONVERGENCE ACROSS SHERIDAN AND CHERRY COUNTIES. THE HRRR SHOWS
SPRINKLES DEVELOPING BUT GIVEN THE VERY DRY AIR MOVING IN WITH
DEW POINTS FALLING INTO THE 20S BY NOON...NO MEASURABLE RAINFALL
WOULD BE EXPECTED.
HIGHS TODAY RISE INTO THE 50S WITH PARTLY CLOUDY SKIES. THE
MODELS ARE BRINGING IN COLD AIR ALOFT FROM AN UPPER LEVEL ACROSS
MANITOBA. THE RESULT IS H700MB TEMPERATURES FALL TO AROUND -10C
BY 21Z. SOME SUN IS EXPECTED BUT SKIES WOULD LIKELY CLOUD UP IN
THE AFTERNOON WITH THE COLD AIR ALOFT.
TONIGHT...THE UPPER LOW ACROSS WRN KS WILL LIFT INTO THE UPPER
MIDWEST AND BE ABSORBED THE A DISTURBANCE ACROSS WRN ONTARIO
TONIGHT. THIS WILL PULL PACIFIC HIGH PRESSURE INTO THE FCST AREA.
GENERALLY CLEAR SKIES ARE EXPECTED WITH LOWS IN THE 20S TO LOWER
30S. WINDS STAY UP AT 10 TO 15 MPH NEAR ONEILL WHERE THE WARMER
LOWS ARE EXPECTED.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 313 AM CDT SUN APR 19 2015
MONDAY INTO MID WEEK WILL SEE THE LOW PRESSURE SYSTEMS TO THE
NORTHEAST AND EAST MERGE NEAR/NORTH OF THE GREAT LAKES. MEANWHILE
NORTHWEST FLOW DOMINATES THE HIGH PLAINS AND AN UPPER LEVEL
TROUGH DIGS ACROSS THE PACIFIC COAST. THE LOW PRESSURE SYSTEM TO
THE NORTHEAST WILL DRAW SOME COOL AND DRY CANADIAN AIR TO THE
REGION. TEMPERATURES WILL BE THE MAIN FOCUS THROUGH MID WEEK AND
ARE TRICKY. THE DRY AIR MOVING SOUTH WILL ALLOW FOR DEW POINTS TO
FALL INTO THE TEENS AND 20S...HOWEVER WITH THE RECENT HEAVY
RAIN...THOUGHT MODELS ARE A TAD TO DRY SO DID RAISE SLIGHTLY BUT
COULD SEE THEM BEING HIGHER...ESPECIALLY BY WED. SKIES WILL
GENERALLY BE MOSTLY CLEAR...ALTHOUGH A COUPLE WEAK CLIPPERS MAY
BRING A BRIEF INCREASE OF CLOUDS. WITH MOSTLY CLEAR SKIES AND DRY
AIR TEMPS TO LIKELY FALL TO OR BELOW THE FREEZING MARK FOR THE
FIRST FEW DAYS OF THE WEEK...UNLESS BL MOISTURE ENDS UP BEING
MORE THAN EXPECTED FROM RECENT RAIN. MEANWHILE AFTERNOON SUN WILL
HELP OFFSET THE COOL CONDITIONS AND BE ABLE TO AID IN MIXING THE
BL...SEASONAL HIGHS /50S AND 60S/ EXPECTED. ONE CONCERN WITH
HIGHS IS THE COOL TEMPS ALOFT...WHICH MAY RESULT IN SOME
AFTERNOON CLOUDS DUE TO STEEP LAPSE RATES DEVELOPING. FAIRLY DRY
AIR AT THE SFC SO NOTHING EXPECTED TO REACH THE GROUND.
BY THE END OF THE WEEK THE WEST COAST TROUGH WILL BECOME AN OPEN
WAVE CROSSING THE DESERT SW/4 CORNERS. A TRANSITION FROM NW TO SW
FLOW WILL BRING A RETURN FOR WET WEATHER. MODELS NOT IN THE BEST
OF AGREEMENT ON TIMING...BUT DO PUSH THE WAVE ONTO THE
SOUTHERN/CENTRAL PLAINS BY THE WEEKEND. SHOULD SEE A BRIEF WINDOW
OF RETURN MOIST SOUTHEASTERLY FLOW AHEAD OF THE WAVE. THIS TRACK
AND THE INCREASE OF MOISTURE WILL FAVOR A CHANCE FOR
RAIN...ALBEIT BETTER FOR SOUTHERN ZONES THAN NORTHERN ZONES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 116 PM CDT SUN APR 19 2015
THE LARGE SLOW MOVING STORM SYSTEM RESPONSIBLE FOR THE WEATHER OF
LATE WILL CONTINUE TO MOVE AWAY FROM THE AREA. VFR CONDITIONS WILL
BE THE RULE...WITH GUSTY NORTHWEST WINDS UP TO 35 KTS THIS
AFTERNOON. WINDS WILL DIMINISH TONIGHT...BUT INCREASE ONCE AGAIN
MONDAY.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...TAYLOR
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
620 AM CDT SUN APR 19 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 313 AM CDT SUN APR 19 2015
THE UPPER LOW WHICH PRODUCED UP TO 52 INCHES OF SNOW IN COLORADO
HAS DRIFTED EAST INTO WRN KS THIS MORNING. RAIN AND THUNDERSTORMS
ARE FALLING UNDER THE LOW. A DEFORMATION ZONE OF RAIN AND
ISOLATED THUNDERSTORMS IS WEAKENING ACROSS NCNTL AND SWRN NEB
THIS MORNING. THE MODELS DRAG THIS AREA OF RAIN SOUTH AND OUT OF
THE FORECAST AREA BY 15Z-18Z. A STRONG COLD FRONT WITH SCATTERED
SHOWERS WILL DROP THROUGH THE FCST AREA THIS MORNING SETTING UP A
WINDY AND COOL DAY. NORTHWEST WINDS WILL INCREASE TO 20 TO 30 MPH
WITH GUSTS TO 40 MPH. THESE WINDS ARE ALREADY UNDERWAY IN THE
PANHANDLE.
THE STRONG WINDS BEND AROUND THE BLACK HILLS PRODUCING
CONVERGENCE ACROSS SHERIDAN AND CHERRY COUNTIES. THE HRRR SHOWS
SPRINKLES DEVELOPING BUT GIVEN THE VERY DRY AIR MOVING IN WITH
DEW POINTS FALLING INTO THE 20S BY NOON...NO MEASURABLE RAINFALL
WOULD BE EXPECTED.
HIGHS TODAY RISE INTO THE 50S WITH PARTLY CLOUDY SKIES. THE
MODELS ARE BRINGING IN COLD AIR ALOFT FROM AN UPPER LEVEL ACROSS
MANITOBA. THE RESULT IS H700MB TEMPERATURES FALL TO AROUND -10C
BY 21Z. SOME SUN IS EXPECTED BUT SKIES WOULD LIKELY CLOUD UP IN
THE AFTERNOON WITH THE COLD AIR ALOFT.
TONIGHT...THE UPPER LOW ACROSS WRN KS WILL LIFT INTO THE UPPER
MIDWEST AND BE ABSORBED THE A DISTURBANCE ACROSS WRN ONTARIO
TONIGHT. THIS WILL PULL PACIFIC HIGH PRESSURE INTO THE FCST AREA.
GENERALLY CLEAR SKIES ARE EXPECTED WITH LOWS IN THE 20S TO LOWER
30S. WINDS STAY UP AT 10 TO 15 MPH NEAR ONEILL WHERE THE WARMER
LOWS ARE EXPECTED.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 313 AM CDT SUN APR 19 2015
MONDAY INTO MID WEEK WILL SEE THE LOW PRESSURE SYSTEMS TO THE
NORTHEAST AND EAST MERGE NEAR/NORTH OF THE GREAT LAKES. MEANWHILE
NORTHWEST FLOW DOMINATES THE HIGH PLAINS AND AN UPPER LEVEL
TROUGH DIGS ACROSS THE PACIFIC COAST. THE LOW PRESSURE SYSTEM TO
THE NORTHEAST WILL DRAW SOME COOL AND DRY CANADIAN AIR TO THE
REGION. TEMPERATURES WILL BE THE MAIN FOCUS THROUGH MID WEEK AND
ARE TRICKY. THE DRY AIR MOVING SOUTH WILL ALLOW FOR DEW POINTS TO
FALL INTO THE TEENS AND 20S...HOWEVER WITH THE RECENT HEAVY
RAIN...THOUGHT MODELS ARE A TAD TO DRY SO DID RAISE SLIGHTLY BUT
COULD SEE THEM BEING HIGHER...ESPECIALLY BY WED. SKIES WILL
GENERALLY BE MOSTLY CLEAR...ALTHOUGH A COUPLE WEAK CLIPPERS MAY
BRING A BRIEF INCREASE OF CLOUDS. WITH MOSTLY CLEAR SKIES AND DRY
AIR TEMPS TO LIKELY FALL TO OR BELOW THE FREEZING MARK FOR THE
FIRST FEW DAYS OF THE WEEK...UNLESS BL MOISTURE ENDS UP BEING
MORE THAN EXPECTED FROM RECENT RAIN. MEANWHILE AFTERNOON SUN WILL
HELP OFFSET THE COOL CONDITIONS AND BE ABLE TO AID IN MIXING THE
BL...SEASONAL HIGHS /50S AND 60S/ EXPECTED. ONE CONCERN WITH
HIGHS IS THE COOL TEMPS ALOFT...WHICH MAY RESULT IN SOME
AFTERNOON CLOUDS DUE TO STEEP LAPSE RATES DEVELOPING. FAIRLY DRY
AIR AT THE SFC SO NOTHING EXPECTED TO REACH THE GROUND.
BY THE END OF THE WEEK THE WEST COAST TROUGH WILL BECOME AN OPEN
WAVE CROSSING THE DESERT SW/4 CORNERS. A TRANSITION FROM NW TO SW
FLOW WILL BRING A RETURN FOR WET WEATHER. MODELS NOT IN THE BEST
OF AGREEMENT ON TIMING...BUT DO PUSH THE WAVE ONTO THE
SOUTHERN/CENTRAL PLAINS BY THE WEEKEND. SHOULD SEE A BRIEF WINDOW
OF RETURN MOIST SOUTHEASTERLY FLOW AHEAD OF THE WAVE. THIS TRACK
AND THE INCREASE OF MOISTURE WILL FAVOR A CHANCE FOR
RAIN...ALBEIT BETTER FOR SOUTHERN ZONES THAN NORTHERN ZONES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 620 AM CDT SUN APR 19 2015
SATELLITE SUGGESTS THE DEFROMATION ZONE CAUSING MVFR CIGS/-RA MAY
HAVE STALLED ACROSS SOUTHERN NEBRASKA.
A COLD FRONT IS RACING SOUTH WHICH SHOULD DRY THIS AIR OUT ENDING
THE RAIN AND LOW CIGS. THIS SUGGESTS VFR WOULD BE WIDESPREAD
THROUGHOUT THE FCST AREA BY 15Z-18Z. VFR IS EXPECTED ALL AREAS
THEREAFTER.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
314 AM CDT SUN APR 19 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 313 AM CDT SUN APR 19 2015
THE UPPER LOW WHICH PRODUCED UP TO 52 INCHES OF SNOW IN COLORADO
HAS DRIFTED EAST INTO WRN KS THIS MORNING. RAIN AND THUNDERSTORMS
ARE FALLING UNDER THE LOW. A DEFORMATION ZONE OF RAIN AND
ISOLATED THUNDERSTORMS IS WEAKENING ACROSS NCNTL AND SWRN NEB
THIS MORNING. THE MODELS DRAG THIS AREA OF RAIN SOUTH AND OUT OF
THE FORECAST AREA BY 15Z-18Z. A STRONG COLD FRONT WITH SCATTERED
SHOWERS WILL DROP THROUGH THE FCST AREA THIS MORNING SETTING UP A
WINDY AND COOL DAY. NORTHWEST WINDS WILL INCREASE TO 20 TO 30 MPH
WITH GUSTS TO 40 MPH. THESE WINDS ARE ALREADY UNDERWAY IN THE
PANHANDLE.
THE STRONG WINDS BEND AROUND THE BLACK HILLS PRODUCING
CONVERGENCE ACROSS SHERIDAN AND CHERRY COUNTIES. THE HRRR SHOWS
SPRINKLES DEVELOPING BUT GIVEN THE VERY DRY AIR MOVING IN WITH
DEW POINTS FALLING INTO THE 20S BY NOON...NO MEASURABLE RAINFALL
WOULD BE EXPECTED.
HIGHS TODAY RISE INTO THE 50S WITH PARTLY CLOUDY SKIES. THE
MODELS ARE BRINGING IN COLD AIR ALOFT FROM AN UPPER LEVEL ACROSS
MANITOBA. THE RESULT IS H700MB TEMPERATURES FALL TO AROUND -10C
BY 21Z. SOME SUN IS EXPECTED BUT SKIES WOULD LIKELY CLOUD UP IN
THE AFTERNOON WITH THE COLD AIR ALOFT.
TONIGHT...THE UPPER LOW ACROSS WRN KS WILL LIFT INTO THE UPPER
MIDWEST AND BE ABSORBED THE A DISTURBANCE ACROSS WRN ONTARIO
TONIGHT. THIS WILL PULL PACIFIC HIGH PRESSURE INTO THE FCST AREA.
GENERALLY CLEAR SKIES ARE EXPECTED WITH LOWS IN THE 20S TO LOWER
30S. WINDS STAY UP AT 10 TO 15 MPH NEAR ONEILL WHERE THE WARMER
LOWS ARE EXPECTED.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 313 AM CDT SUN APR 19 2015
MONDAY INTO MID WEEK WILL SEE THE LOW PRESSURE SYSTEMS TO THE
NORTHEAST AND EAST MERGE NEAR/NORTH OF THE GREAT LAKES. MEANWHILE
NORTHWEST FLOW DOMINATES THE HIGH PLAINS AND AN UPPER LEVEL
TROUGH DIGS ACROSS THE PACIFIC COAST. THE LOW PRESSURE SYSTEM TO
THE NORTHEAST WILL DRAW SOME COOL AND DRY CANADIAN AIR TO THE
REGION. TEMPERATURES WILL BE THE MAIN FOCUS THROUGH MID WEEK AND
ARE TRICKY. THE DRY AIR MOVING SOUTH WILL ALLOW FOR DEW POINTS TO
FALL INTO THE TEENS AND 20S...HOWEVER WITH THE RECENT HEAVY
RAIN...THOUGHT MODELS ARE A TAD TO DRY SO DID RAISE SLIGHTLY BUT
COULD SEE THEM BEING HIGHER...ESPECIALLY BY WED. SKIES WILL
GENERALLY BE MOSTLY CLEAR...ALTHOUGH A COUPLE WEAK CLIPPERS MAY
BRING A BRIEF INCREASE OF CLOUDS. WITH MOSTLY CLEAR SKIES AND DRY
AIR TEMPS TO LIKELY FALL TO OR BELOW THE FREEZING MARK FOR THE
FIRST FEW DAYS OF THE WEEK...UNLESS BL MOISTURE ENDS UP BEING
MORE THAN EXPECTED FROM RECENT RAIN. MEANWHILE AFTERNOON SUN WILL
HELP OFFSET THE COOL CONDITIONS AND BE ABLE TO AID IN MIXING THE
BL...SEASONAL HIGHS /50S AND 60S/ EXPECTED. ONE CONCERN WITH
HIGHS IS THE COOL TEMPS ALOFT...WHICH MAY RESULT IN SOME
AFTERNOON CLOUDS DUE TO STEEP LAPSE RATES DEVELOPING. FAIRLY DRY
AIR AT THE SFC SO NOTHING EXPECTED TO REACH THE GROUND.
BY THE END OF THE WEEK THE WEST COAST TROUGH WILL BECOME AN OPEN
WAVE CROSSING THE DESERT SW/4 CORNERS. A TRANSITION FROM NW TO SW
FLOW WILL BRING A RETURN FOR WET WEATHER. MODELS NOT IN THE BEST
OF AGREEMENT ON TIMING...BUT DO PUSH THE WAVE ONTO THE
SOUTHERN/CENTRAL PLAINS BY THE WEEKEND. SHOULD SEE A BRIEF WINDOW
OF RETURN MOIST SOUTHEASTERLY FLOW AHEAD OF THE WAVE. THIS TRACK
AND THE INCREASE OF MOISTURE WILL FAVOR A CHANCE FOR
RAIN...ALBEIT BETTER FOR SOUTHERN ZONES THAN NORTHERN ZONES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1152 PM CDT SAT APR 18 2015
THE THUNDERSTORMS IN CENTRAL NEBRASKA ARE WEAKENING. LATER
TONIGHT...AS THE UPPER LOW MAKES ITS WAY ONTO THE PLAINS...
SCATTERED SHOWERS WILL COALESCE INTO WIDESPREAD RAIN AFTER 06Z
SOUTH OF AN ONL-MHN-OGA LINE. THEN...AS A FRONT COME
THROUGH...RAIN WILL END FROM THE NORTH IN CENTRAL NEBRASKA BY 11Z
AND IN SOUTH CENTRAL AND SOUTHWEST NEBRASKA EARLY AFTERNOON. THE
RAIN IS EXPECTED TO END BBW-LBF-IML AROUND 13Z.
AFTER 08Z...WIND WILL SHIFT TO 340-360 AT 10-16KT AND THEN
INCREASE TO 14-18G24-30KT BY 14Z
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...SPRINGER
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1154 PM CDT SAT APR 18 2015
.SYNOPSIS...
ISSUED AT 255 PM CDT SAT APR 18 2015
ANALYSIS OF THE 19Z MSL DATA SHOWED LOW PRESSURE CENTERED IN WESTERN
KANSAS WITH A WARM FRONT ACROSS NORTHERN KANSAS...A COLD FRONT INTO
THE OKLAHOMA/TEXAS PANHANDLE AND AN INVERTED TROUGH FROM SOUTHWEST
TO NORTH CENTRAL NEBRASKA. IN THE UPPER LEVELS...THE WATER VAPOR
IMAGERY SHOWED A CLOSED CYCLONIC CIRCULATION LOCATED IN EASTERN
COLORADO.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 255 PM CDT SAT APR 18 2015
THE CENTER OF STRONG CUT OFF LOW /H500 MB TEMP -25C/ IS NEAR AKRON
COLORADO THIS AFTERNOON. HIGH RES MODELS INSIST THAT
CONVECTION...AIDED BY A SIGNIFICANT PV ANOMALY ROTATING NORTHEAST
INTO WESTERN KANSAS AROUND THE LOW CENTER...WILL DEVELOP ONCE AGAIN
ACROSS NORTHWEST KANSAS AND SOUTHWEST NEBRASKA LATE THIS AFTERNOON
AND THIS EVENING. THE ACTIVITY WILL GROW UPSCALE MUCH LIKE LAST
NIGHT AS IT MOVES NORTH/NORTHEAST INTO THE REST OF WESTERN...CENTRAL
AND NORTH CENTRAL NEBRASKA TONIGHT.
AS FAR AS SEVERE POTENTIAL...GOOD SURFACE HEATING UNDERWAY ATTM
ACROSS SOUTHWEST NEBRASKA AND NORTHWEST KANSAS. EXPECTING MUCAPE ON
THE ORDER OF 1500 J/KG BY LATE AFTERNOON INTO THE EVENING HOURS. ONE
WEAKNESS ARE THE WIND FIELDS ARE FAIRLY LIGHT...AND NOT A A LOT OF
VEERING WITH HEIGHT. NEVERTHELESS WITH THE STEEP LOW AND MID LEVEL
LAPSE RATES...WILL SEE SOME VIGOROUS UPDRAFTS...AND SOME HAIL LIKELY
WITH THOSE STRONGER UPDRAFTS. TORNADO POTENTIAL IS NOT ZERO...BUT
AGAIN WITH THE WEAK WIND FIELDS AND LIMITED VEERING...NOT EXPECTING
THAT TO BE THE PRIMARY RISK. IF A TORNADO OCCURS IT WOULD MORE THAN
LIKELY BE WEAK. K INDICES ARE HIGH...AND LOCALLY HEAVY RAINFALL
WILL BE POSSIBLE.
THE CLOSED H500 MB CIRCULATION IS FORECASTED TO MIGRATE INTO
NORTHWEST KANSAS BY SUNDAY MORNING...AND CONTINUE EAST ACROSS KANSAS
DURING THE DAY. A SMALL DEFORMATION BAND OF PRECIPITATION IS LIKELY
ON THE NORTH AND WEST SIDE OF THE TRACK. THE EXACT TRACK OF THE LOW
CENTER IS UNCERTAIN...AS CONVECTION LIKELY TO INFLUENCE THE MASS
FIELD AND EXPECT THE FINAL TRACK COULD END UP A LITTLE FARTHER
NORTH. THIS IS HINTED IN THE LATEST RUN OF THE RAP MODEL. OTHERWISE
A COLD FRONT ASSOCIATED WITH A SEPARATE NORTHERN STREAM SYSTEM WILL
CRASH THROUGH THE AREA...BRINGING GUSTY NORTHWEST WINDS TO THE
REGION.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 255 PM CDT SAT APR 18 2015
MEDIUM RANGE...(SUNDAY NIGHT THROUGH TUESDAY)
THE UPPER LEVEL LOW ACROSS COLORADO WILL LIFT OUT AND COLLIDE WITH
AN UPPER LEVEL SHORT WAVE ACROSS ACROSS THE NORTHERN GREAT LAKES
FORMING A VERY LARGE CLOSED UPPER LOW. UPSTREAM HEIGHTS RISE SHARPLY
ACROSS NRN CANADA SUPPORTING A BROAD AREA OF HIGH PRESSURE WHICH
CIRCULATE COOL AIR SOUTH THROUGH THE PLAINS AND MIDWEST. THIS KEEPS
THE FORECAST AREA IN COOL NORTHWEST FLOW. DAYTIME MIXING PRODUCES
PARTLY CLOUDY SKIES MONDAY AND TUESDAY PLACING A LIMIT ON HEATING.
MONDAY WOULD BE A WINDY DAY WITH NORTHWEST WINDS INCREASING TO 20
TO 30 MPH IN THE AFTN WHICH WEAKEN AT SUNSET. WINDS STAY REASONABLY
STRONG SUNDAY NIGHT ALSO. THE EFFECT ON TEMPERATURES WOULD BE FOR
LOWS MONDAY MORNING FALLING INTO THE UPPER 20S ACROSS WESTERN
NEBRASKA BUT ABOVE FREEZING EAST OF HIGHWAY 83. LOWS FALL BELOW
FREEZING EVERYWHERE MONDAY NIGHT EXCEPT ALONG HIGHWAY 281. HIGHS
RISE INTO THE 50S MONDAY AND LOWER 60S TUESDAY.
THE FORECAST IS DRY AND THE MODELS INDICATE DEW POINTS FALL INTO
TEENS AND 20S SUNDAY NIGHT THROUGH TUESDAY. THE RISK TO THE FORECAST
IS THAT THE VERY DRY AIR COULD SUPPORT COLDER LOWS THAN FORECAST BUT
THAT WOULD COMPETE DIRECTLY WITH THE WARM WET GROUND FROM THE HEAVY
RAINFALL.
EXTENDED RANGE...(TUESDAY NIGHT THROUGH SATURDAY)
A RIDGE IN WESTERN NORTH AMERICA CONTINUES TO BUILD INTO THE
NORTHWEST TERRITORIES AND NORTHERN ALBERTA OPENING UP A PATH FROM
NUNAVUT IN EXTREME NORTHERN CANADA TO NORTH CENTRAL AND NORTHEAST
NEBRASKA. AS A RESULT...TEMPERATURES ARE EXPECTED TO BE A LITTLE
BELOW THE SEASONAL AVERAGES IN THE NORTHEAST NEBRASKA SANDHILLS AND
THE NIOBRARA VALLEY WITH NIGHTTIME TEMPERATURES AT OR BELOW FREEZING
INTO FRIDAY MORNING. EVEN IN THE WESTERN SANDHILLS...THE EASTERN
PANHANDLE AND SOUTHWEST NEBRASKA WILL BE SLIGHTLY BELOW AVERAGE
WITH LOWS IN THE LOW TO MID 30S.
IN THE SOUTHWEST STATES...A TROUGH DIGS INTO SOUTHERN CALIFORNIA
RESULTING IN SOUTHWEST FLOW ALOFT ACROSS THE CENTRAL PLAINS. A WEAK
INVERTED TROUGH MOVING ACROSS THE PLAINS COULD BRING THE POSSIBILITY
OF SHOWERS TO CENTRAL AND WESTERN NEBRASKA THURSDAY THROUGH
SATURDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1152 PM CDT SAT APR 18 2015
THE THUNDERSTORMS IN CENTRAL NEBRASKA ARE WEAKENING. LATER
TONIGHT...AS THE UPPER LOW MAKES ITS WAY ONTO THE PLAINS...
SCATTERED SHOWERS WILL COALESCE INTO WIDESPREAD RAIN AFTER 06Z SOUTH
OF AN ONL-MHN-OGA LINE. THEN...AS A FRONT COME THROUGH...RAIN WILL
END FROM THE NORTH IN CENTRAL NEBRASKA BY 11Z AND IN SOUTH CENTRAL
AND SOUTHWEST NEBRASKA EARLY AFTERNOON. THE RAIN IS EXPECTED TO END
BBW-LBF-IML AROUND 13Z.
AFTER 08Z...WIND WILL SHIFT TO 340-360 AT 10-16KT AND THEN INCREASE
TO 14-18G24-30KT BY 14Z
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SPRINGER
SHORT TERM...TAYLOR
LONG TERM...CDC/SPRINGER
AVIATION...SPRINGER
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
1149 AM MDT SUN APR 19 2015
.AVIATION...
18Z TAF CYCLE
STRONG BACKDOOR COLD FRONT HAS MOVED SOUTH ACROSS OF THE EASTERN
PLAINS. N WIND GUSTS OF 30 TO 35 KT WILL CONTINUE FOR A COUPLE
MORE HOURS AT RTN AND TCC BEFORE DIMINISHING. GUSTS AROUND 40 KT
AT CAO AND CVN. THE BACKDOOR FRONT WILL HELP TRIGGER ISOLATED
AFTERNOON AND EARLY EVE -SHRA AND -TSRA TODAY...MAINLY OVER THE
SANGRE DE CRISTO MOUNTAINS AND ACROSS THE NE. MORE ISOLATED
ACTIVITY POSSIBLE ALONG THE CENTRAL MOUNTAIN CHAIN AND THEIR E
SLOPES. WILL CARRY VCTS AND VCSH AT LVS WITH NO MENTION AT THE
OTHER TAF SITES. ISOLATED...HIGHER BASED CONVECTION POSSIBLE
ACROSS THE SW MTS THIS AFTN. LATE TONIGHT THERE IS A POSSIBILITY
OF SOME NEAR MVFR CIGS ACROSS THE E...INCLUDING LVS..TCC AND ROW.
&&
.PREV DISCUSSION...913 AM MDT SUN APR 19 2015...
.UPDATE...
ADDED QUAY AND CURRY COUNTIES TO THE WIND ADVY FOR TODAY AND
TWEAKED UP WIND SPEEDS OUT THERE. OTHERWISE NO CHANGES.
&&
.PREV DISCUSSION...337 AM MDT SUN APR 19 2015...
.SYNOPSIS...
AN OVERALL UNSETTLED WEATHER PATTERN WILL CONTINUE FOR THE NORTHERN
HIGH TERRAIN AND THE NORTHEAST PLAINS THROUGH ALL OF THIS WEEK. HIGH
TEMPERATURES WILL SLOWLY TREND BACK TOWARD NORMAL THROUGH THE MIDDLE
OF THE WEEK AHEAD OF THE NEXT STORM SYSTEM APPROACHING FROM THE WEST.
DRY SOUTHWEST WINDS WILL INCREASE WEDNESDAY AND THURSDAY FOR WESTERN
AND CENTRAL NEW MEXICO. THE CHANCES FOR SHOWERS AND THUNDERSTORMS
WILL INCREASE AGAIN FOR ALL AREAS FRIDAY AS THE CORE OF AN UPPER LOW
SLIDES OVERHEAD. COOLER TEMPERATURES WILL MOVE BACK INTO THE AREA
BEHIND THIS SYSTEM...WHILE THE CHANCES OF PRECIPITATION CONTINUE
OVER THE NORTH THROUGH NEXT WEEKEND.
&&
.DISCUSSION...
THE FINAL VESTIGES OF WRAP-AROUND PRECIP ARE IMPACTING THE FRONT
RANGE OF COLORADO THIS MORNING AS EVIDENCED BY WIDESPREAD SHOWERS
AND GUSTY NORTH WINDS. THIS ACTIVITY IS INDICATED BY THE 00Z/06Z
NAM AND HRRR GUIDANCE TO CLIP NORTHEAST NM THIS MORNING. QPF WILL
BE LIGHT WITH MOST AREAS REPORTING LESS THAN A TENTH. HIGHS AGAIN
TODAY WILL BE BELOW NORMAL ALL AREAS...WITH READINGS 10-15F BELOW
NORMAL FOR THE EAST. HIGH PRESSURE BUILDING DOWN THE FRONT RANGE
TONIGHT BEHIND THE DEPARTING UPPER LOW WILL HELP FORCE LIGHT GAP
WINDS INTO THE RIO GRANDE VALLEY LATE TONIGHT.
ONE LAST UPPER VORT TRANSLATION WITHIN NW FLOW BEHIND THE DEPARTING
WAVE WILL SLIDE OVER THE NORTHERN MTS AND NE PLAINS MONDAY. THIS
WILL FORCE ANOTHER ROUND OF AFTERNOON SHOWERS NEAR THE HIGH TERRAIN
AS FAR SOUTH AS I-40. AGAIN TEMPS WILL BE BELOW NORMAL WITH A SLIGHT
TREND TOWARD NORMAL FOR THE FAR WEST.
AN AMORPHOUS COMPLEX OF UPPER LEVEL LOW PRESSURE CURRENTLY TAKING
SHAPE ALONG THE WEST COAST WILL BECOME THE NEXT WEATHER PLAYER FOR
MID TO LATE WEEK. GUIDANCE SHOWS H5 HEIGHTS DEEPENING INTO A 562DM
LOW TUESDAY OVER SOUTHERN CALIFORNIA WITH A WEAK SHORTWAVE RIDGE
SLIDING OVER NM. THIS WILL TREND SHOWER AND WIND ACTIVITY DOWNWARD
FOR NM. A 90-110KT 300MB JET AXIS THEN CARVES SOUTHWARD ALONG THE
WEST COAST AND DEEPENS THE TROUGH INTO A TIGHTLY WOUND 550DM H5 LOW
OVER SOUTHERN CALIFORNIA THROUGH THURSDAY. THIS WILL INCREASE MID
LEVEL FLOW AND DEEPEN THE LEE SIDE TROUGH OVER EASTERN NM. WINDS
AND TEMPS WILL INCREASE OVER THE STATE WITH SOME POSSIBLE MARGINAL
FIRE WEATHER ISSUES NOTED WEDNESDAY AND/OR THURSDAY.
BEYOND THURSDAY THERE IS CONSIDERABLE UNCERTAINTY REGARDING THE
TRANSLATION OF LOW PRESSURE OVER NM BY FRIDAY/SATURDAY AND INTO
NEXT WEEK. THE GFS AND ECMWF OPEN THE WAVE AND SLIDE DISORGANIZED
PRECIP OVER THE AREA...FOLLOWED BY A SERIES OF FAST MOVING WEAKLY
DEFINED SHORTWAVE TROUGHS AND RIDGES.
GUYER
&&
.FIRE WEATHER...
WHILE SOME POTENTIAL STILL REMAINS...AS IT CURRENTLY LOOKS THE RISK
OF A RETURN OF CRITICAL FIRE WX CONDITIONS THURSDAY AND FRIDAY HAS
DIMINISHED SOMEWHAT.
A BACK DOOR FRONT MOVING ACROSS THE EASTERN PLAINS THIS MORN AND
INTO THE AFTN WILL BRING INCREASINGLY STRONG AND GUSTY WINDS TO THE
NE PLAINS AND TO A LESSER DEGREE THE EAST CENTRAL PLAINS THIS MORN.
GUSTS NEAR 45 OR 50 MPH ARE POSSIBLE NEAR CLAYTON THIS MORN. WIND
SPEEDS ARE EXPECTED TO DECREASE SOMEWHAT THIS AFTN. CRITICAL FIRE WX
CONDITIONS NOT EXPECTED AS HUMIDITIES TO REMAIN TOO HIGH. AFTN TEMPS
WILL ONLY BE SLIGHTLY COOLER TODAY AS COMPARED TO SATURDAY BEHIND
THE FRONT. AS THE FRONT BACKS UP TO THE CENTRAL MTN CHAIN...EXPECT A
FEW HIGH BASED SHOWERS AND THUNDERSTORMS TO DEVELOP DUE TO UPSLOPE
FLOW...MORE SO ALONG THE EAST SLOPES OF THE SANGRE DE CRISTO MTNS
AND LESS SO FARTHER SOUTH. HUMIDITY RECOVERIES TONIGHT WILL BE GOOD
TO EXCELLENT MOST AREAS OUTSIDE OF WEST CENTRAL AND SW NM WHERE FAIR
TO GOOD RECOVERIES TO BE THE RULE. LOW TEMPS WILL BE A LITTLE ABOVE
NORMAL WEST AND CENTRAL...A BIT BELOW EAST. HIGH TEMPS ON SUNDAY
WILL REMAIN BELOW NORMAL ACROSS THE EAST DUE TO THE FRONTAL
PASSAGE...THOUGH WILL BE INCHING UP TOWARD NORMAL ACROSS THE WEST.
LATER MON...WEAK RIDGE ALOFT WILL DEVELOP ACROSS WESTERN NM...THOUGH
ENOUGH RESIDUAL MOISTURE WILL BE AROUND TO TRIGGER A FEW HIGH BASED
BUILDUPS AND VIRGA IN THE AFTERNOON HOURS. A FEW SPRINKLES MAY
ACTUALLY REACH THE GROUND ACROSS THE NORTHERN HIGH TERRAIN...THOUGH
THE BIGGER CONCERN MAY BE ERRATIC WIND GUSTS WITH ANY VIRGA ACROSS
WESTERN NM. OTHERWISE TEMPS SHOULD WARM TO AROUND 5 DEGREES OF
NORMAL EAST...VERY CLOSE TO NORMAL WEST.
THE BACK DOOR COLD FRONT EARLIER SCHEDULED TO ARRIVE LATER MON NIGHT
INTO TUE MORN HAS BEEN MARGINALIZED AND IN SOME MODELS ELIMINATED
FROM THE SCENE COMPLETELY. STILL MAY BE JUST ENOUGH MOISTURE AND
WEAK UPSLOPE TO CREATE A FEW SHOWERS AND THUNDERSTORMS TUE AFTN WITH
AID OF AFTN HEATING.
WED LOOKS TO BE BREEZY IN MANY AREAS...BUT FOR THE MOST PART THE
STRONGEST WINDS STILL ARE EXPECTED TO ARRIVE THU AND FRI. BUT
CRITICAL CONDITIONS HAVE SHRUNK SIGNIFICANTLY THU AND DO NOT APPEAR
AT ALL FOR FRI. THIS MAY ONLY BE A TEMPORARY REDUCTION AS FCST
MODELS SEEM TO BE IN TRANSITION AGAIN IN THEIR DEPICTION OF UPPER
LVL LOW PRESSURE EVOLUTION OFF TO OUR WEST. THE BACK DOOR FRONT WILL
BE REINFORCED ACROSS NE NM AND SOME THUNDERSTORMS MAY DEVELOP THERE
THU AFTN.
NO VENTILATION ISSUES ARE EXPECTED FOR THE NEXT 6 DAYS...WITH MAINLY
VERY GOOD TO EXCELLENT VENT RATES EXPECTED...THOUGH FAR NORTHEAST NM
MAY DROP INTO THE FAIR OR GOOD CATEGORIES MID TO LATE WEEK. SAT MAY
SEE SOME EROSION OF VENTILATION RATES.
43
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 4 PM MDT THIS AFTERNOON FOR THE FOLLOWING
ZONES...NMZ530-534-535.
&&
$$
40
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
913 AM MDT SUN APR 19 2015
.UPDATE...
ADDED QUAY AND CURRY COUNTIES TO THE WIND ADVY FOR TODAY AND
TWEAKED UP WIND SPEEDS OUT THERE. OTHERWISE NO CHANGES.
&&
.PREV DISCUSSION...553 AM MDT SUN APR 19 2015...
.AVIATION...
12Z TAF CYCLE
SIGNIFICANT BACKDOOR COLD FRONT WILL SLIDE FARTHER SOUTH ACROSS THE
ERN PLAINS THIS MORN. NORTH WINDS OF 18 TO 30KT WITH GUSTS
BETWEEN 35 AND 45KT CAN BE EXPECTED ACROSS THE NE QUARTER OF NM...
THE STRONGEST IN THE VICINITY OF UNION COUNTY BETWEEN 14Z AND 19Z
SUNDAY. THE BACKDOOR FRONT WILL HELP TRIGGER ISOLATED AFTERNOON
AND EARLY EVE -SHRA AND -TSRA TODAY...MAINLY OVER THE NORTHERN MTS
AND ALONG THE EAST SLOPES OF THE CENTRAL MOUNTAIN CHAIN INCLUDING
KLVS...EAST SLOPES OF THE SANGRE DE CRISTOS MOST FAVORED. ISOLATED
EVEN HIGHER BASED CONVECTION POSSIBLE ALSO ACROSS THE SW MTS THIS
AFTN. LATE TONIGHT THERE IS A POSSIBILITY OF SOME NEAR MVFR CIGS
ACROSS AREAS E AND SE FROM THE E SLOPES OF THE SANGRE DE CRISTOS.
43
&&
.PREV DISCUSSION...337 AM MDT SUN APR 19 2015...
.SYNOPSIS...
AN OVERALL UNSETTLED WEATHER PATTERN WILL CONTINUE FOR THE NORTHERN
HIGH TERRAIN AND THE NORTHEAST PLAINS THROUGH ALL OF THIS WEEK. HIGH
TEMPERATURES WILL SLOWLY TREND BACK TOWARD NORMAL THROUGH THE MIDDLE
OF THE WEEK AHEAD OF THE NEXT STORM SYSTEM APPROACHING FROM THE WEST.
DRY SOUTHWEST WINDS WILL INCREASE WEDNESDAY AND THURSDAY FOR WESTERN
AND CENTRAL NEW MEXICO. THE CHANCES FOR SHOWERS AND THUNDERSTORMS
WILL INCREASE AGAIN FOR ALL AREAS FRIDAY AS THE CORE OF AN UPPER LOW
SLIDES OVERHEAD. COOLER TEMPERATURES WILL MOVE BACK INTO THE AREA
BEHIND THIS SYSTEM...WHILE THE CHANCES OF PRECIPITATION CONTINUE
OVER THE NORTH THROUGH NEXT WEEKEND.
&&
.DISCUSSION...
THE FINAL VESTIGES OF WRAP-AROUND PRECIP ARE IMPACTING THE FRONT
RANGE OF COLORADO THIS MORNING AS EVIDENCED BY WIDESPREAD SHOWERS
AND GUSTY NORTH WINDS. THIS ACTIVITY IS INDICATED BY THE 00Z/06Z
NAM AND HRRR GUIDANCE TO CLIP NORTHEAST NM THIS MORNING. QPF WILL
BE LIGHT WITH MOST AREAS REPORTING LESS THAN A TENTH. HIGHS AGAIN
TODAY WILL BE BELOW NORMAL ALL AREAS...WITH READINGS 10-15F BELOW
NORMAL FOR THE EAST. HIGH PRESSURE BUILDING DOWN THE FRONT RANGE
TONIGHT BEHIND THE DEPARTING UPPER LOW WILL HELP FORCE LIGHT GAP
WINDS INTO THE RIO GRANDE VALLEY LATE TONIGHT.
ONE LAST UPPER VORT TRANSLATION WITHIN NW FLOW BEHIND THE DEPARTING
WAVE WILL SLIDE OVER THE NORTHERN MTS AND NE PLAINS MONDAY. THIS
WILL FORCE ANOTHER ROUND OF AFTERNOON SHOWERS NEAR THE HIGH TERRAIN
AS FAR SOUTH AS I-40. AGAIN TEMPS WILL BE BELOW NORMAL WITH A SLIGHT
TREND TOWARD NORMAL FOR THE FAR WEST.
AN AMORPHOUS COMPLEX OF UPPER LEVEL LOW PRESSURE CURRENTLY TAKING
SHAPE ALONG THE WEST COAST WILL BECOME THE NEXT WEATHER PLAYER FOR
MID TO LATE WEEK. GUIDANCE SHOWS H5 HEIGHTS DEEPENING INTO A 562DM
LOW TUESDAY OVER SOUTHERN CALIFORNIA WITH A WEAK SHORTWAVE RIDGE
SLIDING OVER NM. THIS WILL TREND SHOWER AND WIND ACTIVITY DOWNWARD
FOR NM. A 90-110KT 300MB JET AXIS THEN CARVES SOUTHWARD ALONG THE
WEST COAST AND DEEPENS THE TROUGH INTO A TIGHTLY WOUND 550DM H5 LOW
OVER SOUTHERN CALIFORNIA THROUGH THURSDAY. THIS WILL INCREASE MID
LEVEL FLOW AND DEEPEN THE LEE SIDE TROUGH OVER EASTERN NM. WINDS
AND TEMPS WILL INCREASE OVER THE STATE WITH SOME POSSIBLE MARGINAL
FIRE WEATHER ISSUES NOTED WEDNESDAY AND/OR THURSDAY.
BEYOND THURSDAY THERE IS CONSIDERABLE UNCERTAINTY REGARDING THE
TRANSLATION OF LOW PRESSURE OVER NM BY FRIDAY/SATURDAY AND INTO
NEXT WEEK. THE GFS AND ECMWF OPEN THE WAVE AND SLIDE DISORGANIZED
PRECIP OVER THE AREA...FOLLOWED BY A SERIES OF FAST MOVING WEAKLY
DEFINED SHORTWAVE TROUGHS AND RIDGES.
GUYER
&&
.FIRE WEATHER...
WHILE SOME POTENTIAL STILL REMAINS...AS IT CURRENTLY LOOKS THE RISK
OF A RETURN OF CRITICAL FIRE WX CONDITIONS THURSDAY AND FRIDAY HAS
DIMINISHED SOMEWHAT.
A BACK DOOR FRONT MOVING ACROSS THE EASTERN PLAINS THIS MORN AND
INTO THE AFTN WILL BRING INCREASINGLY STRONG AND GUSTY WINDS TO THE
NE PLAINS AND TO A LESSER DEGREE THE EAST CENTRAL PLAINS THIS MORN.
GUSTS NEAR 45 OR 50 MPH ARE POSSIBLE NEAR CLAYTON THIS MORN. WIND
SPEEDS ARE EXPECTED TO DECREASE SOMEWHAT THIS AFTN. CRITICAL FIRE WX
CONDITIONS NOT EXPECTED AS HUMIDITIES TO REMAIN TOO HIGH. AFTN TEMPS
WILL ONLY BE SLIGHTLY COOLER TODAY AS COMPARED TO SATURDAY BEHIND
THE FRONT. AS THE FRONT BACKS UP TO THE CENTRAL MTN CHAIN...EXPECT A
FEW HIGH BASED SHOWERS AND THUNDERSTORMS TO DEVELOP DUE TO UPSLOPE
FLOW...MORE SO ALONG THE EAST SLOPES OF THE SANGRE DE CRISTO MTNS
AND LESS SO FARTHER SOUTH. HUMIDITY RECOVERIES TONIGHT WILL BE GOOD
TO EXCELLENT MOST AREAS OUTSIDE OF WEST CENTRAL AND SW NM WHERE FAIR
TO GOOD RECOVERIES TO BE THE RULE. LOW TEMPS WILL BE A LITTLE ABOVE
NORMAL WEST AND CENTRAL...A BIT BELOW EAST. HIGH TEMPS ON SUNDAY
WILL REMAIN BELOW NORMAL ACROSS THE EAST DUE TO THE FRONTAL
PASSAGE...THOUGH WILL BE INCHING UP TOWARD NORMAL ACROSS THE WEST.
LATER MON...WEAK RIDGE ALOFT WILL DEVELOP ACROSS WESTERN NM...THOUGH
ENOUGH RESIDUAL MOISTURE WILL BE AROUND TO TRIGGER A FEW HIGH BASED
BUILDUPS AND VIRGA IN THE AFTERNOON HOURS. A FEW SPRINKLES MAY
ACTUALLY REACH THE GROUND ACROSS THE NORTHERN HIGH TERRAIN...THOUGH
THE BIGGER CONCERN MAY BE ERRATIC WIND GUSTS WITH ANY VIRGA ACROSS
WESTERN NM. OTHERWISE TEMPS SHOULD WARM TO AROUND 5 DEGREES OF
NORMAL EAST...VERY CLOSE TO NORMAL WEST.
THE BACK DOOR COLD FRONT EARLIER SCHEDULED TO ARRIVE LATER MON NIGHT
INTO TUE MORN HAS BEEN MARGINALIZED AND IN SOME MODELS ELIMINATED
FROM THE SCENE COMPLETELY. STILL MAY BE JUST ENOUGH MOISTURE AND
WEAK UPSLOPE TO CREATE A FEW SHOWERS AND THUNDERSTORMS TUE AFTN WITH
AID OF AFTN HEATING.
WED LOOKS TO BE BREEZY IN MANY AREAS...BUT FOR THE MOST PART THE
STRONGEST WINDS STILL ARE EXPECTED TO ARRIVE THU AND FRI. BUT
CRITICAL CONDITIONS HAVE SHRUNK SIGNIFICANTLY THU AND DO NOT APPEAR
AT ALL FOR FRI. THIS MAY ONLY BE A TEMPORARY REDUCTION AS FCST
MODELS SEEM TO BE IN TRANSITION AGAIN IN THEIR DEPICTION OF UPPER
LVL LOW PRESSURE EVOLUTION OFF TO OUR WEST. THE BACK DOOR FRONT WILL
BE REINFORCED ACROSS NE NM AND SOME THUNDERSTORMS MAY DEVELOP THERE
THU AFTN.
NO VENTILATION ISSUES ARE EXPECTED FOR THE NEXT 6 DAYS...WITH MAINLY
VERY GOOD TO EXCELLENT VENT RATES EXPECTED...THOUGH FAR NORTHEAST NM
MAY DROP INTO THE FAIR OR GOOD CATEGORIES MID TO LATE WEEK. SAT MAY
SEE SOME EROSION OF VENTILATION RATES.
43
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 4 PM MDT THIS AFTERNOON FOR THE FOLLOWING
ZONES...NMZ530-534-535.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
553 AM MDT SUN APR 19 2015
.AVIATION...
12Z TAF CYCLE
SIGNIFICANT BACKDOOR COLD FRONT WILL SLIDE FARTHER SOUTH ACROSS THE
ERN PLAINS THIS MORN. NORTH WINDS OF 18 TO 30KT WITH GUSTS
BETWEEN 35 AND 45KT CAN BE EXPECTED ACROSS THE NE QUARTER OF NM...
THE STRONGEST IN THE VICINITY OF UNION COUNTY BETWEEN 14Z AND 19Z
SUNDAY. THE BACKDOOR FRONT WILL HELP TRIGGER ISOLATED AFTERNOON
AND EARLY EVE -SHRA AND -TSRA TODAY...MAINLY OVER THE NORTHERN MTS
AND ALONG THE EAST SLOPES OF THE CENTRAL MOUNTAIN CHAIN INCLUDING
KLVS...EAST SLOPES OF THE SANGRE DE CRISTOS MOST FAVORED. ISOLATED
EVEN HIGHER BASED CONVECTION POSSIBLE ALSO ACROSS THE SW MTS THIS
AFTN. LATE TONIGHT THERE IS A POSSIBILITY OF SOME NEAR MVFR CIGS
ACROSS AREAS E AND SE FROM THE E SLOPES OF THE SANGRE DE CRISTOS.
43
&&
.PREV DISCUSSION...337 AM MDT SUN APR 19 2015...
.SYNOPSIS...
AN OVERALL UNSETTLED WEATHER PATTERN WILL CONTINUE FOR THE NORTHERN
HIGH TERRAIN AND THE NORTHEAST PLAINS THROUGH ALL OF THIS WEEK. HIGH
TEMPERATURES WILL SLOWLY TREND BACK TOWARD NORMAL THROUGH THE MIDDLE
OF THE WEEK AHEAD OF THE NEXT STORM SYSTEM APPROACHING FROM THE WEST.
DRY SOUTHWEST WINDS WILL INCREASE WEDNESDAY AND THURSDAY FOR WESTERN
AND CENTRAL NEW MEXICO. THE CHANCES FOR SHOWERS AND THUNDERSTORMS
WILL INCREASE AGAIN FOR ALL AREAS FRIDAY AS THE CORE OF AN UPPER LOW
SLIDES OVERHEAD. COOLER TEMPERATURES WILL MOVE BACK INTO THE AREA
BEHIND THIS SYSTEM...WHILE THE CHANCES OF PRECIPITATION CONTINUE
OVER THE NORTH THROUGH NEXT WEEKEND.
&&
.DISCUSSION...
THE FINAL VESTIGES OF WRAP-AROUND PRECIP ARE IMPACTING THE FRONT
RANGE OF COLORADO THIS MORNING AS EVIDENCED BY WIDESPREAD SHOWERS
AND GUSTY NORTH WINDS. THIS ACTIVITY IS INDICATED BY THE 00Z/06Z
NAM AND HRRR GUIDANCE TO CLIP NORTHEAST NM THIS MORNING. QPF WILL
BE LIGHT WITH MOST AREAS REPORTING LESS THAN A TENTH. HIGHS AGAIN
TODAY WILL BE BELOW NORMAL ALL AREAS...WITH READINGS 10-15F BELOW
NORMAL FOR THE EAST. HIGH PRESSURE BUILDING DOWN THE FRONT RANGE
TONIGHT BEHIND THE DEPARTING UPPER LOW WILL HELP FORCE LIGHT GAP
WINDS INTO THE RIO GRANDE VALLEY LATE TONIGHT.
ONE LAST UPPER VORT TRANSLATION WITHIN NW FLOW BEHIND THE DEPARTING
WAVE WILL SLIDE OVER THE NORTHERN MTS AND NE PLAINS MONDAY. THIS
WILL FORCE ANOTHER ROUND OF AFTERNOON SHOWERS NEAR THE HIGH TERRAIN
AS FAR SOUTH AS I-40. AGAIN TEMPS WILL BE BELOW NORMAL WITH A SLIGHT
TREND TOWARD NORMAL FOR THE FAR WEST.
AN AMORPHOUS COMPLEX OF UPPER LEVEL LOW PRESSURE CURRENTLY TAKING
SHAPE ALONG THE WEST COAST WILL BECOME THE NEXT WEATHER PLAYER FOR
MID TO LATE WEEK. GUIDANCE SHOWS H5 HEIGHTS DEEPENING INTO A 562DM
LOW TUESDAY OVER SOUTHERN CALIFORNIA WITH A WEAK SHORTWAVE RIDGE
SLIDING OVER NM. THIS WILL TREND SHOWER AND WIND ACTIVITY DOWNWARD
FOR NM. A 90-110KT 300MB JET AXIS THEN CARVES SOUTHWARD ALONG THE
WEST COAST AND DEEPENS THE TROUGH INTO A TIGHTLY WOUND 550DM H5 LOW
OVER SOUTHERN CALIFORNIA THROUGH THURSDAY. THIS WILL INCREASE MID
LEVEL FLOW AND DEEPEN THE LEE SIDE TROUGH OVER EASTERN NM. WINDS
AND TEMPS WILL INCREASE OVER THE STATE WITH SOME POSSIBLE MARGINAL
FIRE WEATHER ISSUES NOTED WEDNESDAY AND/OR THURSDAY.
BEYOND THURSDAY THERE IS CONSIDERABLE UNCERTAINTY REGARDING THE
TRANSLATION OF LOW PRESSURE OVER NM BY FRIDAY/SATURDAY AND INTO
NEXT WEEK. THE GFS AND ECMWF OPEN THE WAVE AND SLIDE DISORGANIZED
PRECIP OVER THE AREA...FOLLOWED BY A SERIES OF FAST MOVING WEAKLY
DEFINED SHORTWAVE TROUGHS AND RIDGES.
GUYER
&&
.FIRE WEATHER...
WHILE SOME POTENTIAL STILL REMAINS...AS IT CURRENTLY LOOKS THE RISK
OF A RETURN OF CRITICAL FIRE WX CONDITIONS THURSDAY AND FRIDAY HAS
DIMINISHED SOMEWHAT.
A BACK DOOR FRONT MOVING ACROSS THE EASTERN PLAINS THIS MORN AND
INTO THE AFTN WILL BRING INCREASINGLY STRONG AND GUSTY WINDS TO THE
NE PLAINS AND TO A LESSER DEGREE THE EAST CENTRAL PLAINS THIS MORN.
GUSTS NEAR 45 OR 50 MPH ARE POSSIBLE NEAR CLAYTON THIS MORN. WIND
SPEEDS ARE EXPECTED TO DECREASE SOMEWHAT THIS AFTN. CRITICAL FIRE WX
CONDITIONS NOT EXPECTED AS HUMIDITIES TO REMAIN TOO HIGH. AFTN TEMPS
WILL ONLY BE SLIGHTLY COOLER TODAY AS COMPARED TO SATURDAY BEHIND
THE FRONT. AS THE FRONT BACKS UP TO THE CENTRAL MTN CHAIN...EXPECT A
FEW HIGH BASED SHOWERS AND THUNDERSTORMS TO DEVELOP DUE TO UPSLOPE
FLOW...MORE SO ALONG THE EAST SLOPES OF THE SANGRE DE CRISTO MTNS
AND LESS SO FARTHER SOUTH. HUMIDITY RECOVERIES TONIGHT WILL BE GOOD
TO EXCELLENT MOST AREAS OUTSIDE OF WEST CENTRAL AND SW NM WHERE FAIR
TO GOOD RECOVERIES TO BE THE RULE. LOW TEMPS WILL BE A LITTLE ABOVE
NORMAL WEST AND CENTRAL...A BIT BELOW EAST. HIGH TEMPS ON SUNDAY
WILL REMAIN BELOW NORMAL ACROSS THE EAST DUE TO THE FRONTAL
PASSAGE...THOUGH WILL BE INCHING UP TOWARD NORMAL ACROSS THE WEST.
LATER MON...WEAK RIDGE ALOFT WILL DEVELOP ACROSS WESTERN NM...THOUGH
ENOUGH RESIDUAL MOISTURE WILL BE AROUND TO TRIGGER A FEW HIGH BASED
BUILDUPS AND VIRGA IN THE AFTERNOON HOURS. A FEW SPRINKLES MAY
ACTUALLY REACH THE GROUND ACROSS THE NORTHERN HIGH TERRAIN...THOUGH
THE BIGGER CONCERN MAY BE ERRATIC WIND GUSTS WITH ANY VIRGA ACROSS
WESTERN NM. OTHERWISE TEMPS SHOULD WARM TO AROUND 5 DEGREES OF
NORMAL EAST...VERY CLOSE TO NORMAL WEST.
THE BACK DOOR COLD FRONT EARLIER SCHEDULED TO ARRIVE LATER MON NIGHT
INTO TUE MORN HAS BEEN MARGINALIZED AND IN SOME MODELS ELIMINATED
FROM THE SCENE COMPLETELY. STILL MAY BE JUST ENOUGH MOISTURE AND
WEAK UPSLOPE TO CREATE A FEW SHOWERS AND THUNDERSTORMS TUE AFTN WITH
AID OF AFTN HEATING.
WED LOOKS TO BE BREEZY IN MANY AREAS...BUT FOR THE MOST PART THE
STRONGEST WINDS STILL ARE EXPECTED TO ARRIVE THU AND FRI. BUT
CRITICAL CONDITIONS HAVE SHRUNK SIGNIFICANTLY THU AND DO NOT APPEAR
AT ALL FOR FRI. THIS MAY ONLY BE A TEMPORARY REDUCTION AS FCST
MODELS SEEM TO BE IN TRANSITION AGAIN IN THEIR DEPICTION OF UPPER
LVL LOW PRESSURE EVOLUTION OFF TO OUR WEST. THE BACK DOOR FRONT WILL
BE REINFORCED ACROSS NE NM AND SOME THUNDERSTORMS MAY DEVELOP THERE
THU AFTN.
NO VENTILATION ISSUES ARE EXPECTED FOR THE NEXT 6 DAYS...WITH MAINLY
VERY GOOD TO EXCELLENT VENT RATES EXPECTED...THOUGH FAR NORTHEAST NM
MAY DROP INTO THE FAIR OR GOOD CATEGORIES MID TO LATE WEEK. SAT MAY
SEE SOME EROSION OF VENTILATION RATES.
43
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 4 PM MDT THIS AFTERNOON FOR THE FOLLOWING
ZONES...NMZ530.
&&
$$
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
337 AM MDT SUN APR 19 2015
.SYNOPSIS...
AN OVERALL UNSETTLED WEATHER PATTERN WILL CONTINUE FOR THE NORTHERN
HIGH TERRAIN AND THE NORTHEAST PLAINS THROUGH ALL OF THIS WEEK. HIGH
TEMPERATURES WILL SLOWLY TREND BACK TOWARD NORMAL THROUGH THE MIDDLE
OF THE WEEK AHEAD OF THE NEXT STORM SYSTEM APPROACHING FROM THE WEST.
DRY SOUTHWEST WINDS WILL INCREASE WEDNESDAY AND THURSDAY FOR WESTERN
AND CENTRAL NEW MEXICO. THE CHANCES FOR SHOWERS AND THUNDERSTORMS
WILL INCREASE AGAIN FOR ALL AREAS FRIDAY AS THE CORE OF AN UPPER LOW
SLIDES OVERHEAD. COOLER TEMPERATURES WILL MOVE BACK INTO THE AREA
BEHIND THIS SYSTEM...WHILE THE CHANCES OF PRECIPITATION CONTINUE
OVER THE NORTH THROUGH NEXT WEEKEND.
&&
.DISCUSSION...
THE FINAL VESTIGES OF WRAP-AROUND PRECIP ARE IMPACTING THE FRONT
RANGE OF COLORADO THIS MORNING AS EVIDENCED BY WIDESPREAD SHOWERS
AND GUSTY NORTH WINDS. THIS ACTIVITY IS INDICATED BY THE 00Z/06Z
NAM AND HRRR GUIDANCE TO CLIP NORTHEAST NM THIS MORNING. QPF WILL
BE LIGHT WITH MOST AREAS REPORTING LESS THAN A TENTH. HIGHS AGAIN
TODAY WILL BE BELOW NORMAL ALL AREAS...WITH READINGS 10-15F BELOW
NORMAL FOR THE EAST. HIGH PRESSURE BUILDING DOWN THE FRONT RANGE
TONIGHT BEHIND THE DEPARTING UPPER LOW WILL HELP FORCE LIGHT GAP
WINDS INTO THE RIO GRANDE VALLEY LATE TONIGHT.
ONE LAST UPPER VORT TRANSLATION WITHIN NW FLOW BEHIND THE DEPARTING
WAVE WILL SLIDE OVER THE NORTHERN MTS AND NE PLAINS MONDAY. THIS
WILL FORCE ANOTHER ROUND OF AFTERNOON SHOWERS NEAR THE HIGH TERRAIN
AS FAR SOUTH AS I-40. AGAIN TEMPS WILL BE BELOW NORMAL WITH A SLIGHT
TREND TOWARD NORMAL FOR THE FAR WEST.
AN AMORPHOUS COMPLEX OF UPPER LEVEL LOW PRESSURE CURRENTLY TAKING
SHAPE ALONG THE WEST COAST WILL BECOME THE NEXT WEATHER PLAYER FOR
MID TO LATE WEEK. GUIDANCE SHOWS H5 HEIGHTS DEEPENING INTO A 562DM
LOW TUESDAY OVER SOUTHERN CALIFORNIA WITH A WEAK SHORTWAVE RIDGE
SLIDING OVER NM. THIS WILL TREND SHOWER AND WIND ACTIVITY DOWNWARD
FOR NM. A 90-110KT 300MB JET AXIS THEN CARVES SOUTHWARD ALONG THE
WEST COAST AND DEEPENS THE TROUGH INTO A TIGHTLY WOUND 550DM H5 LOW
OVER SOUTHERN CALIFORNIA THROUGH THURSDAY. THIS WILL INCREASE MID
LEVEL FLOW AND DEEPEN THE LEE SIDE TROUGH OVER EASTERN NM. WINDS
AND TEMPS WILL INCREASE OVER THE STATE WITH SOME POSSIBLE MARGINAL
FIRE WEATHER ISSUES NOTED WEDNESDAY AND/OR THURSDAY.
BEYOND THURSDAY THERE IS CONSIDERABLE UNCERTAINTY REGARDING THE
TRANSLATION OF LOW PRESSURE OVER NM BY FRIDAY/SATURDAY AND INTO
NEXT WEEK. THE GFS AND ECMWF OPEN THE WAVE AND SLIDE DISORGANIZED
PRECIP OVER THE AREA...FOLLOWED BY A SERIES OF FAST MOVING WEAKLY
DEFINED SHORTWAVE TROUGHS AND RIDGES.
GUYER
&&
.FIRE WEATHER...
WHILE SOME POTENTIAL STILL REMAINS...AS IT CURRENTLY LOOKS THE RISK
OF A RETURN OF CRITICAL FIRE WX CONDITIONS THURSDAY AND FRIDAY HAS
DIMINISHED SOMEWHAT.
A BACK DOOR FRONT MOVING ACROSS THE EASTERN PLAINS THIS MORN AND
INTO THE AFTN WILL BRING INCREASINGLY STRONG AND GUSTY WINDS TO THE
NE PLAINS AND TO A LESSER DEGREE THE EAST CENTRAL PLAINS THIS MORN.
GUSTS NEAR 45 OR 50 MPH ARE POSSIBLE NEAR CLAYTON THIS MORN. WIND
SPEEDS ARE EXPECTED TO DECREASE SOMEWHAT THIS AFTN. CRITICAL FIRE WX
CONDITIONS NOT EXPECTED AS HUMIDITIES TO REMAIN TOO HIGH. AFTN TEMPS
WILL ONLY BE SLIGHTLY COOLER TODAY AS COMPARED TO SATURDAY BEHIND
THE FRONT. AS THE FRONT BACKS UP TO THE CENTRAL MTN CHAIN...EXPECT A
FEW HIGH BASED SHOWERS AND THUNDERSTORMS TO DEVELOP DUE TO UPSLOPE
FLOW...MORE SO ALONG THE EAST SLOPES OF THE SANGRE DE CRISTO MTNS
AND LESS SO FARTHER SOUTH. HUMIDITY RECOVERIES TONIGHT WILL BE GOOD
TO EXCELLENT MOST AREAS OUTSIDE OF WEST CENTRAL AND SW NM WHERE FAIR
TO GOOD RECOVERIES TO BE THE RULE. LOW TEMPS WILL BE A LITTLE ABOVE
NORMAL WEST AND CENTRAL...A BIT BELOW EAST. HIGH TEMPS ON SUNDAY
WILL REMAIN BELOW NORMAL ACROSS THE EAST DUE TO THE FRONTAL
PASSAGE...THOUGH WILL BE INCHING UP TOWARD NORMAL ACROSS THE WEST.
LATER MON...WEAK RIDGE ALOFT WILL DEVELOP ACROSS WESTERN NM...THOUGH
ENOUGH RESIDUAL MOISTURE WILL BE AROUND TO TRIGGER A FEW HIGH BASED
BUILDUPS AND VIRGA IN THE AFTERNOON HOURS. A FEW SPRINKLES MAY
ACTUALLY REACH THE GROUND ACROSS THE NORTHERN HIGH TERRAIN...THOUGH
THE BIGGER CONCERN MAY BE ERRATIC WIND GUSTS WITH ANY VIRGA ACROSS
WESTERN NM. OTHERWISE TEMPS SHOULD WARM TO AROUND 5 DEGREES OF
NORMAL EAST...VERY CLOSE TO NORMAL WEST.
THE BACK DOOR COLD FRONT EARLIER SCHEDULED TO ARRIVE LATER MON NIGHT
INTO TUE MORN HAS BEEN MARGINALIZED AND IN SOME MODELS ELIMINATED
FROM THE SCENE COMPLETELY. STILL MAY BE JUST ENOUGH MOISTURE AND
WEAK UPSLOPE TO CREATE A FEW SHOWERS AND THUNDERSTORMS TUE AFTN WITH
AID OF AFTN HEATING.
WED LOOKS TO BE BREEZY IN MANY AREAS...BUT FOR THE MOST PART THE
STRONGEST WINDS STILL ARE EXPECTED TO ARRIVE THU AND FRI. BUT
CRITICAL CONDITIONS HAVE SHRUNK SIGNIFICANTLY THU AND DO NOT APPEAR
AT ALL FOR FRI. THIS MAY ONLY BE A TEMPORARY REDUCTION AS FCST
MODELS SEEM TO BE IN TRANSITION AGAIN IN THEIR DEPICTION OF UPPER
LVL LOW PRESSURE EVOLUTION OFF TO OUR WEST. THE BACK DOOR FRONT WILL
BE REINFORCED ACROSS NE NM AND SOME THUNDERSTORMS MAY DEVELOP THERE
THU AFTN.
NO VENTILATION ISSUES ARE EXPECTED FOR THE NEXT 6 DAYS...WITH MAINLY
VERY GOOD TO EXCELLENT VENT RATES EXPECTED...THOUGH FAR NORTHEAST NM
MAY DROP INTO THE FAIR OR GOOD CATEGORIES MID TO LATE WEEK. SAT MAY
SEE SOME EROSION OF VENTILATION RATES.
43
&&
.AVIATION...
06Z TAF CYCLE
A POTENT BACKDOOR COLD FRONT WILL SLIDE DOWN THE ERN PLAINS
OVERNIGHT INTO EARLY SUNDAY MORNING. STRONG NORTH WINDS OF 20 TO
30KT WITH GUSTS NEAR 45 KT WILL BE POSSIBLE ACROSS NE NM...ESPECIALLY
BETWEEN 09Z AND 18Z SUNDAY. THE BACKDOOR FRONT WILL RESULT IN
ISOLATED AFTERNOON SHOWERS AND THUNDERSTORMS SUNDAY...MAINLY OVER
THE NORTHERN AND SOUTHWEST MOUNTAINS AND ALONG THE EAST SLOPES OF
THE CENTRAL MOUNTAIN CHAIN INCLUDING KLVS. WITH WEST TO NORTHWEST
FLOW ALOFT IN PLACE AND ELY UPSLOPE SFC FLOW...A FEW STRONG STORMS
ARE POSSIBLE DURING THE LATE AFTERNOON AND EARLY EVENING FROM THE
EAST SLOPES SANGRE DE CRISTOS EWD TO THE NE PLAINS.
33
&&
.PRELIMINARY POINT TEMPS/POPS...
FARMINGTON...................... 65 34 70 37 / 5 0 5 5
DULCE........................... 62 25 62 28 / 10 10 20 10
CUBA............................ 62 32 64 35 / 10 10 10 10
GALLUP.......................... 65 29 69 32 / 5 5 10 5
EL MORRO........................ 59 33 64 35 / 10 10 10 5
GRANTS.......................... 63 29 67 31 / 10 5 10 5
QUEMADO......................... 61 37 65 37 / 10 5 10 5
GLENWOOD........................ 74 45 76 44 / 5 5 5 5
CHAMA........................... 54 25 55 25 / 20 20 20 10
LOS ALAMOS...................... 57 40 62 41 / 20 10 20 10
PECOS........................... 57 33 60 38 / 10 10 10 10
CERRO/QUESTA.................... 54 24 55 26 / 20 30 30 20
RED RIVER....................... 45 25 46 29 / 30 50 40 30
ANGEL FIRE...................... 48 21 51 24 / 30 30 30 20
TAOS............................ 55 28 59 30 / 20 20 20 20
MORA............................ 54 29 58 34 / 20 20 20 20
ESPANOLA........................ 62 38 66 39 / 10 10 10 10
SANTA FE........................ 57 38 61 41 / 10 10 10 10
SANTA FE AIRPORT................ 63 34 66 36 / 10 10 10 10
ALBUQUERQUE FOOTHILLS........... 65 43 69 46 / 10 5 5 10
ALBUQUERQUE HEIGHTS............. 67 44 71 46 / 5 5 5 5
ALBUQUERQUE VALLEY.............. 68 39 72 41 / 5 5 5 5
ALBUQUERQUE WEST MESA........... 69 41 71 45 / 5 5 5 5
LOS LUNAS....................... 70 36 74 39 / 5 5 5 5
RIO RANCHO...................... 68 42 70 46 / 5 5 5 5
SOCORRO......................... 71 44 75 46 / 10 5 10 5
SANDIA PARK/CEDAR CREST......... 62 38 65 44 / 10 10 10 10
TIJERAS......................... 65 38 67 43 / 10 10 10 10
MORIARTY/ESTANCIA............... 61 29 66 32 / 10 10 10 10
CLINES CORNERS.................. 61 32 63 39 / 10 10 10 10
GRAN QUIVIRA.................... 63 39 66 42 / 10 10 10 10
CARRIZOZO....................... 68 44 70 46 / 10 10 5 5
RUIDOSO......................... 65 37 65 43 / 10 10 5 5
CAPULIN......................... 48 30 55 35 / 40 30 30 30
RATON........................... 54 28 58 31 / 20 40 30 30
SPRINGER........................ 55 31 64 35 / 10 50 20 30
LAS VEGAS....................... 57 29 61 37 / 10 20 20 20
CLAYTON......................... 56 33 63 40 / 20 10 20 40
ROY............................. 56 30 63 37 / 5 20 20 30
CONCHAS......................... 63 39 70 44 / 0 5 10 20
SANTA ROSA...................... 64 35 69 43 / 5 5 10 10
TUCUMCARI....................... 66 35 72 43 / 0 5 10 30
CLOVIS.......................... 65 37 68 43 / 0 5 5 20
PORTALES........................ 68 38 70 45 / 0 0 0 20
FORT SUMNER..................... 67 38 70 44 / 0 5 5 10
ROSWELL......................... 71 44 72 45 / 0 5 0 5
PICACHO......................... 68 40 69 44 / 5 10 5 5
ELK............................. 65 38 65 44 / 10 10 5 5
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 4 PM MDT THIS AFTERNOON FOR THE FOLLOWING
ZONES...NMZ530.
&&
$$
AREA FORECAST DISCUSSION
NWS RALEIGH NC
735 PM EDT MON APR 20 2015
.SYNOPSIS...A COLD FRONT WILL TRACK EAST ACROSS THE REGION TONIGHT.
HIGH PRESSURE WILL BUILD IN FROM THE SOUTHWEST LATE TONIGHT THROUGH
TUESDAY... THEN SHIFT OFF THE COAST TUESDAY NIGHT INTO WEDNESDAY.
A COLD FRONT WILL APPROACH FROM THE NORTH WEDNESDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 735 PM MONDAY...
UPDATE: MODEST PW HAS KEPT COVERAGE FROM GETTING OUT OF HAND SO FAR.
WE`RE SEEING PLENTY OF HIGH REFLECTIVITIES IN THE LOWEST 15-20
KFT... HOWEVER CORES ABOVE 25 KFT HAVE BEEN FAIRLY MUTED... AND TOPS
HAVE STRUGGLED TO REACH 30-35 KFT. THIS MAY BE A RESULT OF WEAK
INSTABILITY ABOVE 25 KFT... NOTED IN THE LATEST RAP SOUNDINGS.
NEVERTHELESS... WE`VE STILL MANAGED TO GET VIGOROUS ENOUGH
CONVECTION WITH PERSISTENT CELLS POSSESSING LONG-LIVED MESOCYCLONIC
CHARACTERISTICS TO GENERATE SEVERAL REPORTS OF DIME TO QUARTER SIZE
HAIL. SPC MESOANALYSES STILL HAVE EFFECTIVE DEEP LAYER SHEAR IN
EXCESS OF 45 KTS WITH MODEST MLCAPE NEAR 1000 J/KG... STILL
INDICATIVE OF POTENTIAL FOR A FEW SEVERE CELLS. WILL RETAIN THE
SEVERE THUNDERSTORM WATCH FOR MUCH OF THE PIEDMONT... AND BASED ON
THE THIS FAVORABLE AIR MASS EXTENDING INTO THE NE CWA AND ON
EXTRAPOLATION OF EXISTING SEVERE AND NEAR-SEVERE STORMS... HAVE
ADDED AREAS TO THE WATCH... MAINLY ALONG/NORTH OF A LINE FROM
LILLINGTON TO SMITHFIELD TO WILSON. COVERAGE SO FAR HAS BEEN LIMITED
TO AREAS FROM RALEIGH TO THE NORTH AND WEST. THE LATEST CONVECTION
ALLOWING MODELS SHOW LITTLE TO NO ACTIVITY OVER THE SE CORNER OF THE
CWA. HAVE REDUCED POPS IN THE SOUTHEAST FOR THE REMAINDER OF THE
NIGHT. -GIH
NOW THROUGH THIS EVENING: NUMEROUS SIGNALS CONTINUE TO SUPPORT AN
ENHANCED RISK OF SEVERE STORMS IN CENTRAL NC. HEATING/MIXING
DISSIPATED THE WEAK CAP OVER THE REGION NEARLY 2 HOURS AGO...
YIELDING EXPLOSIVE CONVECTION TO OUR SW OVER NE GA AND UPSTATE SC.
SEE NO REASON WHY THIS WON`T CONTINUE TO EXPAND NORTHEASTWARD TOWARD
CENTRAL NC OVER THE NEXT FEW HOURS. KINEMATICS REMAIN ROBUST WITH
EFFECTIVE DEEP LAYER SHEAR OVER 40 KTS (ACCORDING TO SPC
MESOANALYSES) AND RAP ANALYSES REVEALING A LONG STRAIGHT LINE
HODOGRAPH SUPPORTIVE OF SPLITTING SUPERCELLS. MLCAPE AND MUCAPE
VALUES ARE RAPIDLY GROWING AND NOW SIT NEAR 1000 J/KG AND 1500-2000
J/KG RESPECTIVELY... AND LOW LEVEL LAPSE RATES HAVE REACHED NEAR 8
C/KM. THESE FACTORS ALONG WITH DERIVED PARAMETERS INCLUDING THE
CRAVEN SIGSVR AND SUPERCELL COMPOSITE PARAMETER SUPPORT SUSTAINED
SUPERCELLS. PW VALUES ARE ABOVE NORMAL BUT NOT INCREDIBLY HIGH...
AND THIS MAY LIMIT COVERAGE SOMEWHAT INITIALLY... BUT ALL
INDICATIONS ARE THAT CONVECTION WILL GROW AND CONGEAL INTO A LINEAR
MCS OR OR MULTICELL CLUSTERS AFFECTING A LARGER AREA. DAMAGING
STRAIGHT LINE WINDS AND LARGE HAIL STILL LOOK TO BE THE PRIMARY
THREATS... GIVEN THE LONG STRAIGHT HODOGRAPH AND FAT CAPE IN THE 0C
TO -30C LAYER WITH CONVECTION ALLOWING MODELS INDICATING STRONG
UPDRAFTS. INTENSE TORNADOES LOOK TO BE LESS LIKELY WITH LCL HEIGHTS
UP TO 1000 M CURRENTLY AND SOMEWHAT MARGINAL STORM RELATIVE HELICITY
VALUES... BUT A FEW TORNADOES REMAIN POSSIBLE IN THIS ENVIRONMENT.
STORM MOTION IS EXPECTED TO BE 40-50 MPH FROM THE WSW... AND THESE
TRANSLATIONAL SPEEDS WILL EXACERBATE THE EFFECTS OF ANY STRONG WINDS
ASSOCIATED WITH INDIVIDUAL STORMS. STRONG TO SEVERE CONVECTION NOW
OVER THE GSP CWA WILL CONTINUE TO EXPAND TO THE NE... SO EXPECT THE
GREATEST SEVERE RISK OVER CENTRAL NC TO BE BETWEEN 4 PM AND 8 PM...
GRADUALLY TAPERING DOWN AFTERWARD... WITH LITTLE MORE THAN ISOLATED
TRAILING SHOWERS AFTER 11 PM.
AFTER MIDNIGHT: THE COLD FRONT WILL MOVE ESE THROUGH CENTRAL NC
BETWEEN MIDNIGHT AND 6 AM... AND EXPECT CLEARING SKIES WITH THE
ONSET OF DOWNSLOPE LOW LEVEL FLOW AND A DRYING COLUMN. STILL EXPECT
LOWS FROM AROUND 50 IN THE NW TO AROUND 60 SE AS COOLER AIR RUSHES
IN LATE. -GIH
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 330 PM MONDAY...
THE COLD FRONT WILL HAVE PUSHED JUST SE OF THE FORECAST AREA BY
DAYBREAK TUE... WITH HIGH PRESSURE BUILDING IN FROM THE GULF
STATES... THEN DRIFTING ACROSS GA/SRN SC. FORECAST SOUNDINGS SHOW A
STABLE AND DRY COLUMN WITH JUST A FEW FLAT CU NEAR THE TOP OF THE
MIXED LAYER IN THE AFTERNOON. A PASSING WEAK VORTICITY MAX COULD
ALSO BRING A STREAM OF MID/HIGH CLOUDS IN THE EVENING. HIGHS BELOW
NORMAL AT 68-74 WITH PARTLY TO MOSTLY SUNNY SKIES. MOSTLY CLEAR TUE
NIGHT WITH THE HIGH SHIFTING OFF THE COAST. LOWS 44-50. -GIH
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 300 PM MONDAY...
WEDNESDAY THROUGH THURSDAY NIGHT...DRY CONDITIONS WILL PERSIST ON
WEDNESDAY AS HIGH PRESSURE ACROSS THE SOUTHEAST US GRADUALLY SLIPS
OFFSHORE WEDNESDAY MORNING/EARLY AFTERNOON. ANOTHER COLD FRONT WILL
APPROACH THE AREA LATE WEDNESDAY INTO THURSDAY. HOWEVER...LIMITED
MOISTURE RETURN AHEAD OF THIS SYSTEM WILL KEEP PRECIP CHANCES
MINIMAL. NEVERTHELESS...WILL KEEP A SLIGHT CHANCE POP IN THE
FORECAST FOR WEDNESDAY NIGHT/EARLY THURSDAY...BUT MOST PLACES WILL
LIKELY STAY DRY AND THOSE THAT SEE PRECIP WILL HAVE MEAGER AMOUNTS.
HIGHS ON WEDNESDAY WILL RISE INTO THE MID/UPPER 70S...WHILE ON
THURSDAY HIGHS WILL RANGE FROM THE UPPER 60S ACROSS THE NORTH
(EARLIER FRONTAL PASSAGE) TO THE MID 70S FURTHER SOUTH. OVERNIGHT
LOWS WILL GENERALLY BE IN THE MID/UPPER 40S TO LOWER 50S (COOLEST
THURSDAY NIGHT BEHIND THE FRONT).
FRIDAY THROUGH MONDAY...UNCERTAINTY REMAINS FAIRLY HIGH WITH RESPECT
TO THE END OF THE WEEK AND ESPECIALLY INTO THE WEEKEND. THE OVERALL
PATTERN INDICATES THE AFOREMENTIONED COLD FRONT WILL STALL JUST
SOUTH OF THE REGION FOR THE END OF THE WEEK. THEN...AS A SOUTHERN
STREAM SYSTEM APPROACHES...MULTIPLE WAVES OF LOW PRESSURE WILL RIDE
ALONG THIS BOUNDARY...SPREADING PRECIP BACK INTO THE AREA.
HOWEVER...AS CAN BE EXPECTED THIS FAR OUT...DETAILS HAVE YET TO BE
WORKED OUT. REGARDLESS...WILL SHOW POPS EARLY IN THE WEEKEND WITH...
AS OF NOW AT LEAST...DRIER CONDITIONS BY SUNDAY. MONDAY ALSO LOOKS
TO BE DRY...BUT ANOTHER SYSTEM IS PROGGED TO BE ON OUR DOORSTEP BY
LATE MONDAY/MONDAY NIGHT. TEMPS WILL GENERALLY BE NEAR TO SLIGHTLY
BELOW NORMAL THROUGH THE TIME FRAME.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
AS OF 735 PM MONDAY...
SCATTERED STORMS WILL CONTINUE TO AFFECT PORTIONS OF CENTRAL NC WITH
BRIEF PERIODS OF SUB-VFR CONDITIONS. ONE BAND OF SCATTERED STORMS
WILL AFFECT RDU THROUGH 03Z... AND WILL POTENTIALLY REACH RWI
AFFECTING THAT SITE 02Z-05Z. AT THIS TIME... IT APPEARS THAT THE
STORMS WILL HOLD LARGELY TO THE NORTHEAST OF FAY. A SECOND BAND OF
STORMS OVER THE NRN FOOTHILLS AND NRN MOUNTAINS OF NC MAY SKIRT NEAR
INT BUT IS ALSO EXPECTED TO STAY MAINLY NW OF THE TRIAD. BRIEF MVFR
TO IFR CONDITIONS ARE POSSIBLE IN AND NEAR STORMS... AS WELL AS PEA
TO QUARTER SIZE HAIL. OTHERWISE... VFR CONDITIONS WILL DOMINATE
THROUGH TONIGHT. WINDS FROM THE SW AT 10-15 KTS GUSTING TO 20-25 KTS
WILL PERSIST... VEERING AROUND TO WESTERLY WITH DIMINISHING GUSTS
AFTER PASSAGE OF A COLD FRONT AFTER 04Z. A SHORT PERIOD OF MVFR CIGS
ARE POSSIBLE WITH FRONTAL PASSAGE... BUT GENERALLY WE EXPECT VFR
CONDITIONS LATE TONIGHT THROUGH THE END OF THE TAF VALID PERIOD WITH
MOSTLY CLEAR SKIES.
LOOKING BEYOND 00Z WED... VFR CONDITIONS SHOULD HOLD THROUGH WED AS
HIGH PRESSURE BUILDS OVER THE REGION. A FEW HOURS OF SUB-VFR
CIGS/VSBYS WITH A FEW SHOWERS ARE POSSIBLE WED EVENING/NIGHT INTO
EARLY THU AS A DISTURBANCE MOVES QUICKLY ACROSS THE DEEP SOUTH AND
SOUTHEAST STATES. VFR CONDITIONS AND COOLER WEATHER WILL FOLLOW FOR
LATE THU INTO SAT. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES... NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...HARTFIELD
LONG TERM...KRD
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
622 PM EDT SUN APR 19 2015
.SYNOPSIS...
A FRONTAL SYSTEM WILL BRING SHOWERS AND A FEW THUNDERSTORMS
THROUGH MONDAY. A FEW STORMS MAY BE STRONG TO SEVERE. DRY AND
SEASONABLE HIGH PRESSURE WILL BUILD INTO THE AREA TUESDAY AND
WEDNESDAY. WARMER TEMPERATURES ARE EXPECTED THURSDAY AHEAD OF
THE NEXT COLD FRONT. MUCH COOLER TEMPERATURES ARE POSSIBLE
LATE WEEK AND INTO NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF 555 PM SUNDAY...TORNADO WATCH NUMBER 82 THRU 11 PM REMAINS
IN EFFECT FOR THE ILM SC CWA...PLUS ROBESON COUNTY OF THE ILM NC
CWA.
BROKEN LINE OF STRONG TO SEVERE THUNDERSTORMS IS ON THE WESTERN
DOORSTEPS OF THE ILM CWA AT THE MOMENT. POPS HAVE BEEN RE-ADJUSTED
THRUOUT THIS EVENING TO TAKE INTO ACCOUNT OF THE TIMING AND
PROGRESSION OF THIS LINE AS IT TRAVERSES THE ILM CWA. AT THIS
POINT...THE CUMULATIVE THINKING IS THAT THE CONVECTION WILL WEAKEN
TO BELOW SEVERE LIMITS BY THE TIME IT PROGRESSES ACROSS THE ILM NC
COUNTIES LATER THIS EVENING AND OVERNIGHT AND THEREFORE A WATCH IS
WAS NOT PLANNED AT THIS TIME.
PREVIOUS........................................................
AS OF 315 PM SUNDAY...AS LIGHT STRATIFORM RAINFALL PULLS NE AWAY
FROM THE REGION THIS AFTERNOON...A MORE ORGANIZED BAND OF SHOWERS
AND TSTMS WILL MOVE INTO NE SC 6 PM - 7 PM...AND INTO SE NC IN THE
MIDDLE AND LATE EVENING. THIS IS APT TO BRING SIGNIFICANTLY MORE
RAINFALL AMOUNTS TO THE AREA TONIGHT. SATELLITE DERIVED SENSORS OF
PRECIPITABLE WATERS SHOW A LARGE SWATH OF 46MM/1.81 INCH PWATS
MOVING INTO THE AREA THAT WILL HELP FUEL THE CONVECTION. SEVERAL
ISOLATED OR DISCREET CELLS MAY ALSO FIRE AHEAD OF THE ORGANIZED
RAIN AREA AFTER THE STRATIFORM RAIN HAS CLEARED. SEVERAL RECENT
NEAR TERM MODELS SHOWS THE BULK OF RAINFALL MOVING NE OF SE NC
AFTER 5Z/1AM. THE ORGANIZED NATURE OF THIS FEATURE IF HELD INTACT
WILL INTRODUCE A SLIGHT CHANCE OF WIND DAMAGE OR HAIL TONIGHT.
MINIMUMS TONIGHT WILL NOT FALL MUCH BELOW THE MIDDLE 60S EVEN IN
RAIN COOLED LOCATIONS AS DEWPOINTS REMAIN ELEVATED.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...THE CWA WILL BE IN A RATHER WARM AND BLUSTERY
SOUTHWEST FLOW AT THE BEGINNING OF THE PERIOD...IN BETWEEN A
DEPARTING WARM FRONT TO THE NORTHEAST AND A COLD FRONT ACROSS THE
TENNESSEE VALLEY. THIS FRONT MOVES STEADILY ACROSS THE SOUTHEAST
DURING THE DAY AND SHOULD BE JUST ACROSS OUR WESTERN COUNTIES BY
0000 UTC TUESDAY. SEVERE PARAMETERS STILL LOOK CONDUCIVE FOR AN
EVENT WITH ADEQUATE INSTABILITY AND SHEAR. HOWEVER HIGH
RESOLUTION GUIDANCE IS SHOWING A LACK OF ACTIVITY WITH THE FRONT.
THE MET HAS SIX HOUR POPS IN THE SINGLE DIGITS FOR THE 18-00 UTC
TIME FRAME IN LBT AND ILM. THE GFS REMAINS MORE BULLISH WITH
SCATTERED ACTIVITY AHEAD OF A CONVECTIVE LINE. WILL MAINTAIN THE
CHANCE POPS AND FINE TUNE FOR THE TIMING FOR LATE AFTERNOON INTO
THE EVENING. SPC MAINTAINS THE SLIGHT RISK FOR THE AREA CITING THE
UNCERTAINTY. BEYOND THIS HIGH PRESSURE BUILDS IN FOR A NICE
TUESDAY AND PEACEFUL WEDNESDAY MORNING.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 300 PM SUNDAY...HIGH PRESSURE BOTH MOVES OFFSHORE AND WEAKENS
CONSIDERABLY. PAIR THIS WITH ZONAL MID FLOW AND THE AFTERNOON SHOULD
BE SEASONABLE AND RAIN-FREE WITH A FAIR AMOUNT OF SUNSHINE. THE
APPROACH OF A COLD FRONT WILL YIELD A SMALL RISE IN POPS ON THURSDAY
OR POSSIBLY EVEN WEDNESDAY NIGHT. THIS SLOW MOVING BOUNDARY MOVES
THROUGH ON THURSDAY BUT WILL HAVE TO DEAL WITH MIDLEVEL DOWNSLOPING
PREVENTING DEEP MOISTURE. THE FRONT STALLS SOUTH OF THE REGION
POSSIBLY CLOSE ENOUGH FOR THE MAINTENANCE OF LOW END POPS. SOME
DEEPER MOISTURE AND MORE MEANINGFUL RAIN CHANCES MAY MATERIALIZE
OVER THE WEEKEND AS THE FRONT REMAINS TO OUR SOUTH BUT SOME WEAK MID
LEVEL IMPULSES WORK TO PROVIDE LIFT ATOP SOME LOW LEVEL ISENTROPIC
UPGLIDE.
&&
.AVIATION /22Z SUNDAY THROUGH FRIDAY/...
AS OF 18Z...SOME CONVECTION IS TRYING TO MOVE ONSHORE NEAR
ILM...OTHERWISE THE COASTAL TERMINALS MAY NOT SEE TOO MUCH ACTION
INITIALLY. MAINLY A EAST SOUTHEAST WIND THIS AFTERNOON. THIS
EVENING...THE HRRR IS STAYING FAIRLY CONSISTENT IN BRINGING IN AN
ORGANIZED LINE OF OF CONVECTION TO THE INLAND TERMINALS AROUND 23Z.
WILL LEAN HEAVILY ON THIS MODEL THROUGH THE EVENING HOURS. AFTER THE
CONVECTION MOVES THROUGH...EXPECT IFR CEILING THROUGH THE OVERNIGHT
HOURS...WITH SOME LIGHT FOG. MONDAY...IMPROVING CEILINGS AS THE DAY
WEARS ON WITH A GUSTY SOUTHWEST WIND. CONVECTION IS EXPECTED TO FIRE
AFTER THE END OF THE FORECAST PERIOD.
EXTENDED OUTLOOK...A COLD FRONT WILL PUSH THROUGH THE AREA MONDAY
NIGHT WITH SHOWERS POSSIBLE FOLLOWED BY MAINLY VFR CONDITIONS
TUESDAY AND WEDNESDAY. POSSIBLE SHOWERS THURSDAY AND FRIDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 555 PM SUNDAY...TOR WATCH 82 AFFECTS THE ILM SC WATERS THRU
11 PM. THE MARINE BOUNDARY LAYER OVER THE COOLER SHELF WATERS
WILL ACT TO WEAKEN CONVECTION AS IT REACHES AND MOVES ACROSS ALL
WATERS DURING THIS EVENING. THE STRONGER STORMS THIS EVENING THAT
AFFECT THE ILM SC WATERS COULD PRODUCE SMW CRITERIA BRIEF GALE
FORCE WIND GUSTS OR WATERSPOUTS. OTHERWISE...THE MAJORITY OF THE
CONVECTION WILL PRODUCE MWS CRITERIA WINDS AND LIGHTNING.
PREVIOUS........................................................
AS OF 315 PM SUNDAY...SEAS SLOWLY ON THE RISE IN THE MODERATE
ONSHORE WIND FLOW AND 3-5 FOOT SEAS EXPECTED OVERNIGHT. SEVERAL
TSTMS ARRIVING FROM THE SW TONIGHT MAY PRODUCE LOCALLY HIGHER WINDS
AND SEAS...AND SEVERAL SPECIAL MARINE WARNINGS MAY BE NEEDED FOR
TONIGHT WITH CLOUD TO SEA LIGHTNING POSING AN ADDITIONAL HAZARD.
WINDS WILL VEER TO S AND SW OVERNIGHT WHICH WILL HELP TO LIMIT WAVE
GROWTH AND A SMALL CRAFT ADVISORY IS NOT PLANNED ALTHOUGH AN
EXERCISE CAUTION STATEMENT COULD BE NEEDED.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...A SOUTHWEST FLOW OF 10-15 KNOTS INITIALLY WILL
INCREASE TO 15-20 BY THE END OF THE DAY MONDAY AS A FRONT MOVES
CLOSER FROM THE WEST. THE FRONT FINALLY CROSSES THE WATERS EARLY
TUESDAY MORNING WITH A MODEST WESTERLY FLOW OF 10-15 KNOTS IN ITS
WAKE. SMOOTH SAILING FOR THE REMAINDER OF THE PERIOD WITH WINDS TEN
KNOTS OR LESS FROM THE WEST NORTHWEST AND SEAS OF 2-4 FEET.
LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 300 PM SUNDAY...WEDNESDAY BRINGS NEARLY MINIMAL WIND AND SEAS
DUE TO HIGH PRESSURE MOVING OVERHEAD. WINDS THOUGH LIGHT WILL VEER
CONSIDERABLY AS THE DAY PROGRESSES UNTIL A S TO SW FLOW BECOMES
PREDOMINANT LATE IN THE DAY OR AT NIGHT. MORE VEERING IS SLATED FOR
THURSDAY AS A COLD FRONT APPROACHES AND VERY SLOWLY CROSSES THE
WATERS. WITH THIS FRONT STALLING NEARBY TO OUR SOUTH ON FRIDAY A
LIGHT NORTHERLY FLOW WILL BE MAINTAINED.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SHK
NEAR TERM...DCH/MJC
SHORT TERM...SHK
LONG TERM...MBB
AVIATION...MJC/SHK/DL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
319 PM EDT SUN APR 19 2015
.SYNOPSIS...
A FRONTAL SYSTEM WILL BRING SHOWERS AND A FEW THUNDERSTORMS
THROUGH MONDAY. A FEW STORMS MAY BE STRONG TO SEVERE. DRY AND
SEASONABLE HIGH PRESSURE WILL BUILD INTO THE AREA TUESDAY AND
WEDNESDAY. WARMER TEMPERATURES ARE EXPECTED THURSDAY AHEAD OF
THE NEXT COLD FRONT. MUCH COOLER TEMPERATURES ARE POSSIBLE
LATE WEEK AND INTO NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF 315 PM SUNDAY...AS LIGHT STRATIFORM RAINFALL PULLS NE AWAY
FROM THE REGION THIS AFTERNOON...A MORE ORGANIZED BAND OF SHOWERS
AND TSTMS WILL MOVE INTO NE SC 6 PM - 7 PM...AND INTO SE NC IN THE
MIDDLE AND LATE EVENING. THIS IS APT TO BRING SIGNIFICANTLY MORE
RAINFALL AMOUNTS TO THE AREA TONIGHT. SATELLITE DERIVED SENSORS OF
PRECIPITABLE WATERS SHOW A LARGE SWATH OF 46MM/1.81 INCH PWATS
MOVING INTO THE AREA THAT WILL HELP FUEL THE CONVECTION. SEVERAL
ISOLATED OR DISCREET CELLS MAY ALSO FIRE AHEAD OF THE ORGANIZED
RAIN AREA AFTER THE STRATIFORM RAIN HAS CLEARED. SEVERAL RECENT
NEAR TERM MODELS SHOWS THE BULK OF RAINFALL MOVING NE OF SE NC
AFTER 5Z/1AM. THE ORGANIZED NATURE OF THIS FEATURE IF HELD INTACT
WILL INTRODUCE A SLIGHT CHANCE OF WIND DAMAGE OR HAIL TONIGHT.
MINIMUMS TONIGHT WILL NOT FALL MUCH BELOW THE MIDDLE 60S EVEN IN
RAIN COOLED LOCATIONS AS DEWPOINTS REMAIN ELEVATED.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...THE CWA WILL BE IN A RATHER WARM AND BLUSTERY
SOUTHWEST FLOW AT THE BEGINNING OF THE PERIOD...IN BETWEEN A
DEPARTING WARM FRONT TO THE NORTHEAST AND A COLD FRONT ACROSS THE
TENNESSEE VALLEY. THIS FRONT MOVES STEADILY ACROSS THE SOUTHEAST
DURING THE DAY AND SHOULD BE JUST ACROSS OUR WESTERN COUNTIES BY
0000 UTC TUESDAY. SEVERE PARAMETERS STILL LOOK CONDUCIVE FOR AN
EVENT WITH ADEQUATE INSTABILITY AND SHEAR. HOWEVE HIGH RESOLUTION
GUIDANCE IS SHOWING A LACK OF ACVITITY WITH THE FRONT. THE MET HAS
SIX HOUR POPS IN THE SINGLE DIGITS FOR THE 18-00 UTC TIME FRAME IN
LBT AND ILM. THE GFS REMAINS MORE BULLISH WITH SCATTERED ACTIVITY
AHEAD OF A CONVECTIVE LINE. WILL MAINTAIN THE CHANCE POPS AND FINE
TUNE FOR THE TIMING FOR LATE AFTERNOON INTO THE EVENING. SPC
MAINTAINS THE SLIGHT RISK FOR THE AREA CITING THE UNCERTAINTY.
BEYOND THIS HIGH PRESSURE BUILDS IN FOR A NICE TUESDAY AND PEACEFUL
WEDNESDAY MORNING.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 300 PM SUNDAY...HIGH PRESSURE BOTH MOVES OFFSHORE AND WEAKENS
CONSIDERABLY. PAIR THIS WITH ZONAL MID FLOW AND THE AFTERNOON SHOULD
BE SEASONABLE AND RAIN-FREE WITH A FAIR AMOUNT OF SUNSHINE. THE
APPROACH OF A COLD FRONT WILL YIELD A SMALL RISE IN POPS ON THURSDAY
OR POSSIBLY EVEN WEDNESDAY NIGHT. THIS SLOW MOVING BOUNDARY MOVES
THROUGH ON THURSDAY BUT WILL HAVE TO DEAL WITH MIDLEVEL DOWNSLOPING
PREVENTING DEEP MOISTURE. THE FRONT STALLS SOUTH OF THE REGION
POSSIBLY CLOSE ENOUGH FOR THE MAINTENANCE OF LOW END POPS. SOME
DEEPER MOISTURE AND MORE MEANINGFUL RAIN CHANCES MAY MATERIALIZE
OVER THE WEEKEND AS THE FRONT REMAINS TO OUR SOUTH BUT SOME WEAK MID
LEVEL IMPULSES WORK TO PROVIDE LIFT ATOP SOME LOW LEVEL ISENTROPIC
UPGLIDE.
&&
.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
AS OF 18Z...SOME CONVECTION IS TRYING TO MOVE ONSHORE NEAR
ILM...OTHERWISE THE COASTAL TERMINALS MAY NOT SEE TOO MUCH ACTION
INITIALLY. MAINLY A EAST SOUTHEAST WIND THIS AFTERNOON. THIS
EVENING...THE HRRR IS STAYING FAIRLY CONSISTENT IN BRINGING IN AN
ORGANIZED LINE OF OF CONVECTION TO THE INLAND TERMINALS AROUND 23Z.
WILL LEAN HEAVILY ON THIS MODEL THROUGH THE EVENING HOURS. AFTER THE
CONVECTION MOVES THROUGH...EXPECT IFR CEILING THROUGH THE OVERNIGHT
HOURS...WITH SOME LIGHT FOG. MONDAY...IMPROVING CEILINGS AS THE DAY
WEARS ON WITH A GUSTY SOUTHWEST WIND. CONVECTION IS EXPECTED TO FIRE
AFTER THE END OF THE FORECAST PERIOD.
EXTENDED OUTLOOK...A COLD FRONT WILL PUSH THROUGH THE AREA MONDAY
NIGHT WITH SHOWERS POSSIBLE FOLLOWED BY MAINLY VFR CONDITIONS
TUESDAY AND WEDNESDAY. POSSIBLE SHOWERS THURSDAY AND FRIDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 315 PM SUNDAY...SEAS SLOWLY ON THE RISE IN THE MODERATE
ONSHORE WIND FLOW AND 3-5 FOOT SEAS EXPECTED OVERNIGHT. SEVERAL
TSTMS ARRIVING FROM THE SW TONIGHT MAY PRODUCE LOCALLY HIGHER WINDS
AND SEAS...AND SEVERAL SPECIAL MARINE WARNINGS MAY BE NEEDED FOR
TONIGHT WITH CLOUD TO SEA LIGHTNING POSING AN ADDITIONAL HAZARD.
WINDS WILL VEER TO S AND SW OVERNIGHT WHICH WILL HELP TO LIMIT WAVE
GROWTH AND A SMALL CRAFT ADVISORY IS NOT PLANNED ALTHOUGH AN
EXERCISE CAUTION STATEMENT COULD BE NEEDED.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...A SOUTHWEST FLOW OF 10-15 KNOTS INITIALLY WILL
INCREASE TO 15-20 BY THE END OF THE DAY MONDAY AS A FRONT MOVES
CLOSER FROM THE WEST. THE FRONT FINALLY CROSSES THE WATERS EARLY
TUESDAY MORNING WITH A MODEST WESTERLY FLOW OF 10-15 KNOTS IN ITS
WAKE. SMOOTH SAILING FOR THE REMAINDER OF THE PERIOD WITH WINDS TEN
KNOTS OR LESS FROM THE WEST NORTHWEST AND SEAS OF 2-4 FEET.
LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 300 PM SUNDAY...WEDNESDAY BRINGS NEARLY MINIMAL WIND AND SEAS
DUE TO HIGH PRESSURE MOVING OVERHEAD. WINDS THOUGH LIGHT WILL VEER
CONSIDERABLY AS THE DAY PROGRESSES UNTIL A S TO SW FLOW BECOMES
PREDOMINANT LATE IN THE DAY OR AT NIGHT. MORE VEERING IS SLATED FOR
THURSDAY AS A COLD FRONT APPROACHES AND VERY SLOWLY CROSSES THE
WATERS. WITH THIS FRONT STALLING NEARBY TO OUR SOUTH ON FRIDAY A
LIGHT NORTHERLY FLOW WILL BE MAINTAINED.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SHK
NEAR TERM...MJC
SHORT TERM...SHK
LONG TERM...MBB
AVIATION...DL
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
201 PM EDT SUN APR 19 2015
.SYNOPSIS...
HIGH PRESSURE EXTENDING OVER THE AREA FROM THE NORTH WILL SHIFT
OFFSHORE TODAY. A WARM FRONT WILL LIFT NORTHEAST ACROSS THE AREA
TONIGHT AS LOW PRESSURE MOVES INTO THE OHIO VALLEY. A COLD FRONT
WILL MOVE THROUGH FROM THE WEST EARLY TUESDAY FOLLOWED BY HIGH
PRESSURE WEDNESDAY. ANOTHER COLD FRONT WILL MOVE IN FROM THE
NORTHWEST THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 110 PM SUNDAY...FORECAST PRETTY MUCH ON TRACK WITH A
MODERATE TO HEAVY SHOWERS DRIFTING IN FROM THE OCEAN AND THE
LEADING EDGE OF THE WIDESPREAD RAIN SHIELD IS MOVING INTO SOUTH
CENTRAL NORTH CAROLINA. GENERALLY FOLLOWED THE 3KM HRRR WHICH IS
DOING A GOOD JOB OF DEPICTING THE RAINFALL. NO CHANGES THROUGH THE
AFTERNOON AS RAIN BECOMES WIDESPREAD AND STEADY. CONVECTIVE
DEVELOPMENT POTENTIAL SEEMS LIMITED BASED ON CURRENT PARAMETERS AS
BEST INSTABILITY OCCURRING MUCH FURTHER SOUTHWEST ACROSS
GEORGIA...ALABAMA AND THE FLORIDA PANHANDLE. NO CHANGE TO
TEMPERATURE FORECAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
AS OF 400 AM SUNDAY...LATEST GDNC CONTINUES TO INDICATE WET
CONDITIONS TONIGHT AND INCREASED POPS TO 100% ALL ZONES. DIFFLUENT
UPR FLOW AHEAD OF UPR TROF LIFTING OUT OF SRN PLAINS WILL INDUCE
LARGE SCALE ASCENT ACROSS AREA ALONG WITH DEEP MSTR PLUME FROM
GULFMEX. SFC WARM FRONT WILL APPROACH FROM SW AS DEVELOPING LOW
PRES MOVES INTO WRN OH VLY. WDSPRD SHOWERS AND PSBLY SCT TSTMS
EXPECTED TO GRADUALLY SPREAD SW TO NE ACROSS ERN NC OVERNIGHT. QPF
LOWERED SLIGHTLY BASED ON HPC AND LATEST MODEL BLEND...BUT MOST
AREAS STILL SEEING 1/2 TO 1 INCH.
PER NEAR-TERM...MARGINAL SVR THREAT FOR SW SECTIONS WITH SOME
POTENTIAL FOR ROTATING STORMS ALONG AND AHEAD OF WARM FRONT.
GENERALLY A HIGH SHEAR/LOW CAPE THREAT WITH WDSPRD CLOUDS AND PCPN
LIMITING INSTABILITY.
MIN TEMPS MAINLY LOW-MID 60S EVEN WITH WDSPRD RAIN.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
AS OF 350 AM SUNDAY...BY MONDAY, THE UPPER TROUGH WILL SHIFT
EAST NEAR THE GREAT LAKES REGION WITH SEVERAL SHORTWAVES/
VORTICITY MAXIMA ROTATING AROUND THE BASE OF THE UPPER TROUGH. THE
SURFACE LOW WILL MOVE NORTHEAST INTO SOUTHEASTERN CANADA WITH THE
ATTENDANT COLD FRONT WELL NORTH OF THE REGION. THE BEST LIFT FROM
THE NORTHERN STREAM LIFTS WELL NORTH OF THE AREA WHILE THE
SOUTHERN STREAM JET REMAINS WELL SOUTHWEST OF EASTERN NC. THE BEST
MOISTURE ALSO LIFTS WELL NORTH OF EASTERN NC WITH FORECAST
SOUNDINGS INDICATING PWATS FALLING TO 1.20 INCHES MONDAY
AFTERNOON. GUIDANCE IS IN GOOD AGREEMENT WITH A SHORTWAVE/VORT MAX
MOVING THROUGH EASTERN NC MONDAY AFTERNOON/EVENING WHICH COULD
HELP SUPPORT OR ENHANCE ONGOING CONVECTION. 500 MB TEMPS FALL
FROM AROUND -11/-12 C SUNDAY TO -15/-16 C MONDAY AFTERNOON
INDICATING A FAVORABLE ENVIRONMENT FOR LARGE HAIL SHOULD STORMS
BECOME SEVERE. GIVEN SOUTHWESTERLY UNIDIRECTIONAL SHEAR, CAN ALSO
EXPECT A FEW SHOWERS/THUNDERSTORMS ALONG THE INLAND MOVING SEA-
BREEZE. AS DRY SLOTTING DEVELOPS MONDAY MORNING, CLOUD COVER WILL
DIMINISH ALLOWING EXCELLENT INSOLATION. INSTABILITY WILL BE
PLENTIFUL THOUGH THE ENVIRONMENT WILL A TRIGGER FOR CONVECTIVE
INITIATION, AND LACK VEERING LOW LEVEL WINDS. SPC MAINTAINS A
SLIGHT RISK FOR EASTERN NC THROUGH MONDAY EVENING/NIGHT. BIGGEST
THREAT WILL BE LARGE HAIL AND DAMAGING WIND GUSTS, THOUGH AN
ISOLATED TORNADO CANNOT BE RULED OUT.
INCREASED POPS TO CHANCE INLAND MONDAY AFTERNOON. HIGHS MONDAY
WILL BE IN THE LOW 80S INLAND AND MID 70S BEACHES.
MONDAY NIGHT/TUESDAY...COLD FRONT MOVES OFFSHORE LATE MONDAY NIGHT
AND EARLY TUESDAY MORNING WITH SLIGHTLY COOLER AND DRIER AIR
MOVING IN. TUESDAY`S HIGHS SHOULD BE IN THE MID 70S...BUT WITH
DEWPOINTS DOWN IN THE LOWER 50S BY AFTERNOON.
TUESDAY NIGHT/WEDNESDAY...HIGH PRESSURE BUILDS OVERHEAD WITH
MAINLY HIGH CLOUDS WEDNESDAY. COOL MORNING LOWS AROUND 50 REBOUND
TO AFTERNOON HIGHS IN THE MID 70S.
WEDNESDAY NIGHT/THURSDAY...ZONAL FLOW ALOFT CONTINUES AS A COLD
FRONT CROSSES THE REGION LATE THURSDAY. GUIDANCE IN MODEST
AGREEMENT FOR LIGHT SHOWERS/THUNDERSTORMS THURSDAY, THUS HAVE
INTRODUCED SLIGHT CHANCE POP WITH FRONTAL PASSAGE. ANOTHER COOL
MORNING THURSDAY WITH LOWS 50 TO 55...REBOUNDING INTO THE UPPER
70S THURSDAY AFTERNOON.
THURSDAY NIGHT/FRIDAY...DRY WEATHER BEHIND THE FRONT WITH SUNNY
COOLER WEATHER FOR FRIDAY. LOWS AGAIN IN THE 50 TO 55 DEGREE
RANGE WITH HIGHS UPPER 60S FAR NORTHEAST AND LOW 70S ELSEWHERE.
FRIDAY NIGHT/SATURDAY...ANOTHER SOUTHERN STREAM SYSTEM APPROACHES
LATE SATURDAY. HAVE INDICATED INCREASED CLOUD COVER AND A SMALL
CHANCE OF RAIN IN THE AFTERNOON.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
SHORT TERM /THROUGH 18Z MONDAY/...
AS OF 140 PM SUNDAY...VFR CONDITIONS WILL PERSIST FOR ANOTHER ONE
TO TWO HOURS...BEFORE CONDITIONS BEGIN TO DETERIORATE THIS
AFTERNOON. SE WINDS WILL CONTINUE THROUGH THIS EVENING AT 10 TO 15
KNOTS. WIDESPREAD SHOWERS WILL SPREAD FROM THE SW TO NE THIS
AFTERNOON WITH A SLIGHT CHANCE OF THUNDERSTORMS THROUGH LATE THIS
EVENING. GUIDANCE AND MODEL SOUNDING ARE SHOWING WIDESPREAD IFR
CONDITIONS FOR ALL TAF SITES SHORTLY AFTER 00Z. IFR CONDITIONS
WILL PERSIST THROUGH THE OVERNIGHT UNDER WIDESPREAD RAIN SHOWERS.
CONDITIONS WILL IMPROVE BY 12Z MONDAY AS RAIN SHOWERS TAPERS OFF
TO THE EAST. EXPECTING VFR CONDITIONS TO RETURN BY 15Z MONDAY
UNDER SCT CLOUDS.
LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 355 AM SUNDAY...PRECIPITATION DIMINISHES MONDAY BUT SOME
ISOLATED STRONG TO SEVERE TSTMS MAY BE POSSIBLE, ESPECIALLY KPGV
AND KISO, MONDAY AFTERNOON AND EVENING WHICH COULD PRODUCE SUB-VFR
AVIATION CONDITIONS. HIGH PRESSURE BUILDS IN ACROSS EASTERN NC
TUESDAY INTO WEDNESDAY YIELDING MOSTLY VFR CONDITIONS. A WEAK
FRONT WILL MOVE SOUTH INTO EASTERN NC THURSDAY BUT WITH LIMITED
MOISTURE SO EXPECT MOSTLY VFR CONDITIONS THURSDAY.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 115 PM SUNDAY...WINDS HAVE DROPPED A BIT FROM THIS MORNING
WITH GENERALLY E/NE WIND 10 TO 15 KNOTS WITH SOME GUSTS TO AROUND
21 KNOTS AT DIAMOND SHOALS. SEAS STILL 3 TO 5 FEET WITH LONG
PERIOD SWELLS OVER THE CENTRAL AND NORTHERN WATERS. WINDS BECOME
SE LATER TODAY AS WARM FRONT LIFTS NORTH. WINDS INCREASE TO 15 TO
20 KNOTS BY THIS EVENING. PRES GRAD WILL TIGHTEN TONIGHT WITH WARM
FRONT MOVING IN FROM SW...RESULTING IN WINDS BECOMING S-SW 20-25
KT. SEAS BUILDING TO 4-6 FT OUTER WATERS LATE TODAY AND PEAKING
6-8 FT LATE TONIGHT.
LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 355 AM SUNDAY...GUSTY S/SW WINDS WILL BUILD SEAS TO 7-8 FEET
MONDAY. SEAS WILL REMAIN ELEVATED INTO TUESDAY MORNING AND CURRENT
SCA FOR ALL COASTAL WATERS WILL REMAIN IN EFFECT UNTIL 12Z TUESDAY.
HIGH PRESSURE WILL BUILD OVER THE NC WATERS TUESDAY INTO WEDNESDAY
WITH WINDS SHIFTING MORE WESTERLY, 5-15 KT. SEAS WILL DIMINISH TO
2-4 FT TUESDAY NIGHT THROUGH WEDNESDAY. A COLD FRONT WILL MOVE
SOUTH INTO THE NORTHERN WATERS THURSDAY AND SHIFT SOUTH OF THE
WATERS THURSDAY NIGHT. WINDS VEER NORTHWEST BEHIND THE FRONT BUT
REMAIN 5-15 KT WITH SEAS 2-4 FEET.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO 8 AM EDT
TUESDAY FOR AMZ150-152-154-156-158.
&&
$$
SYNOPSIS...JBM
NEAR TERM...CTC
SHORT TERM...JBM
LONG TERM...DAG
AVIATION...DAG/BM
MARINE...CTC/JBM/DAG
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
148 PM EDT SUN APR 19 2015
.SYNOPSIS...
A FRONTAL SYSTEM WILL BRING SHOWERS AND A FEW THUNDERSTORMS
THROUGH MONDAY. A FEW STORMS MAY BE STRONG TO SEVERE. DRY AND
SEASONABLE HIGH PRESSURE WILL BUILD INTO THE AREA TUESDAY AND
WEDNESDAY. WARMER TEMPERATURES ARE EXPECTED THURSDAY AHEAD OF
THE NEXT COLD FRONT. MUCH COOLER TEMPERATURES ARE POSSIBLE
LATE WEEK AND INTO NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1244 PM SUNDAY...NO SIGNIFICANT CHANGES FOR THE EARLY
AFTERNOON UPDATE...WITH POP DISTRIBUTION RANGING FROM SCATTERED
TO LIKELY ACROSS THE AREA AND A SLIGHT CHANCE OF A THUNDERSTORM.
EXTENSIVE CLOUD COVER WILL LIMIT SURFACE BASED BUOYANCY BUT A
RAMPING UP IN PRECIPITABLE WATERS AS SEEN IN SATELLITE DATA WILL
LIKELY REMOVE ANY CONVECTIVE INHIBITION AND POP-UP SHOWERS COULD
OCCUR ANYWHERE NEAR SMALL OUTFLOWS...DIFFERENTIAL HEATING...AND
WEAK SEA BREEZE CONVERGENCE ZONES. A BROAD AREA OF PATCHY LIGHT
RAIN WILL SPREAD NE ACROSS THE AREA THROUGH THE AFTERNOON. THE
PREVIOUS DISCUSSION FOLLOWS.
ADJUSTMENTS WERE REQUIRED TO SCALE BACK TIMING AND COVERAGE OF
PRECIPITATION TODAY...BASED ON DECLINING NATURE OF SHOWERS
ASSOCIATED WITH AN APPROACHING WARM FRONTAL FEATURE. SEVERAL
SHOWERS WILL MAKE A RUN TOWARD THE NORTH COAST FROM THE
OCEAN...AND AREAS WEST OF I-95 APPEAR POISED TO RECEIVE A TENTH
OF AN INCH THROUGH MIDDAY...OTHERWISE PROSPECTS OF SOLID RAIN
MEASUREMENTS WERE DECREASED IN THE FORECAST AND THE GRIDDED
PRODUCTS THROUGH EARLY AFTERNOON. SOME HOPE REMAINS FOR BREAKS IN
THE CLOUD COVER TO OFFER LOW-LEVEL HEATING WHICH COULD INITIATE
CONVECTION WITH WEAK SEA BREEZE CONVERGENCE. BETTER RAIN CHANCES
APPEAR OVERNIGHT PER SEVERAL OF THE NEAR TERM MODELS. FORECAST FOR
TODAY NOW READS SCATTERED EXCEPT FAR WESTERN ZONES LIKELY. DESPITE
REDUCTION IN POPS AND TIMING...A FEW TSTMS COULD BECOME STRONG AND
SPC MAINTAINS MARGINAL RISK OVER NC AND SLIGHT RISK OVER PORTIONS
OF NE SC TODAY.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 AM SUNDAY...INTERESTING START TO THE WORK WEEK AS A
SHORTWAVE EMBEDDED WITHIN A DEEPENING TROUGH WILL CREATE THE
POTENTIAL FOR STRONG THUNDERSTORMS ON MONDAY.
WARM FRONT WILL BE WELL NORTH OF THE AREA MONDAY MORNING...AND MOST
OF THE HEAVY RAINFALL ANTICIPATED SUNDAY NIGHT WILL BE
NORTH/OFFSHORE BY THE BEGINNING OF THE PERIOD. SOME RESIDUAL SHOWERS
MAY PERSIST ON THE COAST EARLY...BUT ACTUALLY EXPECT THE MORNING
HOURS TO BE DRY FOR THE MOST PART LOCALLY. THE COLUMN WILL DRY
CONSIDERABLY FROM SUNDAY AS THE BEST MOISTURE DEPARTS TO THE
NE...AND SOME SUBSIDENCE IS EXPECTED BEHIND AN EXITING SHORTWAVE.
THIS WILL LEAVE AT LEAST PARTIAL INSOLATION...AND AS WARM/MOIST
ADVECTION CONTINUES THE ATMOSPHERE WILL BECOME QUITE UNSTABLE MONDAY
AFTN/EVE. FORECAST MLCAPE VALUES RISE TOWARDS 2000 J/KG...WITH THE
SREF MEAN AROUND 1500 J/KG. AT THE SAME TIME...A SHORTWAVE WILL RIDE
THROUGH THE DEEPENING TROUGH SO PVA COMBINED WITH HEIGHT FALLS
/STEEPENING MID-LEVEL LAPSE RATES/ WILL DRIVE AN ENVIRONMENT
CONDUCIVE TO STRONG CONVECTION. ADDITIONALLY...LFQ OF A SUBTROPICAL
250MB JET WILL APPROACH FROM THE SW. HOWEVER...SURFACE FORCING IS
MOSTLY WEAK AND THE MID-LEVELS REMAIN QUITE DRY DURING THE MOST
UNSTABLE PART OF THE DAY. THIS SUGGESTS THAT ACTIVITY WILL BE
ISOLATED OR SCATTERED MONDAY AFTN/EVE...BUT ANY STORM WILL HAVE
THE POTENTIAL TO BECOME STRONG AND SPC HAS THE AREA IN A SLIGHT
RISK FOR MONDAY. DO NOT EXPECT WIDESPREAD STRONG/SEVERE
STORMS...AND ATTM THE BEST FOCUS MAY BE ALONG THE PIEDMONT TROUGH
AND WESTERN PORTIONS OF THE CWA.
COLD FRONT WILL APPROACH SLOWLY FROM THE NW DRIVEN BY THE DEEPENING
UPPER TROUGH...AND IS NOW SLATED FOR A CROSSING JUST BEFORE DAWN
TUESDAY. THIS FRONT WILL BE ACCOMPANIED BY MORE WIDESPREAD SHOWER
ACTIVITY...BUT NOT EXPECTING STRONG CONVECTION WITH ITS PASSAGE.
COLD ADVECTION LAGS THE FRONT CONSIDERABLY...SO WHILE TUESDAY WILL
BE DRY WITH MUCH MORE SUNSHINE AS HIGH PRESSURE BUILDS ACROSS THE
REGION...TEMPS WILL NOT BE SIGNIFICANTLY COOLER THAN MONDAY.
ON THE DISCUSSION OF TEMPERATURES...MONDAY WILL LIKELY BE WELL ABOVE
NORMAL WITH WIDESPREAD 80S AWAY FROM THE BEACHES ON STRONG WARM
ADVECTION AHEAD OF THE FRONT. A RELATIVELY WARM NIGHT EXPECTED
MONDAY NIGHT AS FROPA OCCURS LATE...AND LOWS WILL DROP ONLY INTO THE
LOW 60S. SLIGHTLY COOLER TUESDAY WITH HIGHS REACHING WELL INTO THE
70S TO NEAR 80...BEFORE COOL DRY HIGH PRESSURE ALLOWS FOR TEMPS TO
CRASH TO AROUND 50 TUESDAY NIGHT.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 300 AM SUNDAY...MID-LEVELS EVOLVE INTO A DECIDEDLY WINTER-LIKE
APPEARANCE THROUGH THE EXTENDED WITH A LARGE VORTEX CUTOFF ACROSS
SOUTHEAST CANADA WHICH WILL SLOWLY DROP ACROSS NEW ENGLAND BY THE
WKND. INITIALLY THIS PRODUCES BENIGN AND SEASONABLE WEATHER ACROSS
THE CAROLINAS...AS THE FLOW BECOMES ZONAL BENEATH THE CUTOFF...SO
SURFACE HIGH PRESSURE WILL BECOME THE DOMINANT FEATURE WED/THU. THIS
HIGH WILL MOVE OFFSHORE THURSDAY AHEAD OF THE NEXT COLD
FRONT...DRIVEN BY A PIECE OF VORT ENERGY ROTATING AROUND THE LARGE
MID-LEVEL VORTEX. MID-LEVEL FLOW REMAINS W/NW HOWEVER...SO ALTHOUGH
PRECIP CHANCES INCREASE WITH THE COLD FRONT...SIGNIFICANT SHOWER
ACTIVITY IS NOT ANTICIPATED. THE BIGGER STORY COULD BE MUCH COOLER
TEMPS BEHIND THIS FRONT FRI/SAT THANKS TO 1000-500MB THICKNESSES
DROPPING TOWARDS -2 SD`S FROM CLIMO...AND HIGHS/LOWS BY SATURDAY
COULD FALL WELL BELOW NORMAL. A LOW PRESSURE SYSTEM MAY BEGIN TO
EMERGE FROM THE GULF COAST STATES AND MOVE TOWARDS THE AREA AT THE
END OF THE PERIOD...AND WILL MAINTAIN INHERITED LOW-CHC POP FOR
SATURDAY.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
AS OF 18Z...SOME CONVECTION IS TRYING TO MOVE ONSHORE NEAR
ILM...OTHERWISE THE COASTAL TERMINALS MAY NOT SEE TOO MUCH ACTION
INITIALLY. MAINLY A EAST SOUTHEAST WIND THIS AFTERNOON. THIS
EVENING...THE HRRR IS STAYING FAIRLY CONSISTENT IN BRINGING IN AN
ORGANIZED LINE OF OF CONVECTION TO THE INLAND TERMINALS AROUND 23Z.
WILL LEAN HEAVILY ON THIS MODEL THROUGH THE EVENING HOURS. AFTER THE
CONVECTION MOVES THROUGH...EXPECT IFR CEILING THROUGH THE OVERNIGHT
HOURS...WITH SOME LIGHT FOG. MONDAY...IMPROVING CEILINGS AS THE DAY
WEARS ON WITH A GUSTY SOUTHWEST WIND. CONVECTION IS EXPECTED TO FIRE
AFTER THE END OF THE FORECAST PERIOD.
EXTENDED OUTLOOK...A COLD FRONT WILL PUSH THROUGH THE AREA MONDAY
NIGHT WITH SHOWERS POSSIBLE FOLLOWED BY MAINLY VFR CONDITIONS
TUESDAY AND WEDNESDAY. POSSIBLE SHOWERS THURSDAY AND FRIDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1244 PM SUNDAY...LOW PRESSURE OVER THE MID-MISSISSIPPI
VALLEY WILL DEEPEN TODAY. THE INCREASING SOUTHERLY WIND AHEAD OF
THIS SYSTEM WILL DRAG A WARM FRONT THROUGH THE COASTAL CAROLINAS
THIS AFTERNOON. GENERALLY EASTERLY WINDS THIS MORNING WILL VEER
SOUTHEASTERLY THIS AFTERNOON...THEN SOUTHERLY TONIGHT. WINDS WILL
INCREASE BUT NOT EXCESSIVELY SO GIVEN THE PRETTY LARGE DISTANCE
FROM HERE BACK TO THE LOW...AND ALSO THE FACT THAT THE INCOMING
AIRMASS WILL BE SIGNIFICANTLY WARMER THAN THE OCEAN SURFACE
LEADING TO MOST OF THE WIND ENERGY RIDING UP AND OVER A COOL AND
STABLE LAYER OF AIR AT THE SURFACE.
WIDESPREAD SHOWERS AND EMBEDDED T-STORMS SHOULD AFFECT THE COASTAL
WATERS THIS AFTERNOON AND TONIGHT. REDUCED VISIBILITY IN HEAVY
RAINFALL AND ALSO OCCASIONAL LIGHTNING STRIKES WILL BE THE MOST
SIGNIFICANT IMPACTS. SEAS WILL GRADUALLY BUILD DUE TO THE ONSHORE
FLOW...WITH THE WORST CONDITIONS EXPECTED NORTH OF CAPE FEAR. THERE
IS A 4-6 HOUR WINDOW LATE THIS EVENING INTO EARLY MONDAY MORNING
WHERE A SMALL CRAFT ADVISORY MAY BE NEEDED NORTH OF CAPE FEAR DUE TO
6 FOOT SEAS...BUT GIVEN SOME REMAINING UNCERTAINTY ABOUT HOW LONG
SOUTHERLY WINDS BLOW BEFORE VEERING SOUTHWESTERLY AND WEAKENING...I
WILL DELAY RAISING THE ADVISORY JUST YET.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 AM SUNDAY...COLD FRONT APPROACHING FROM THE WEST WILL
PINCH THE GRADIENT MONDAY...AND GUSTY SW WINDS WILL REACH 15-20
KTS WITH SLIGHTLY HIGHER GUSTS. THIS WILL PERSIST ALL OF MONDAY
SINCE THE COLD FRONT IS NOT EXPECTED TO CROSS OFFSHORE UNTIL FIRST
LIGHT TUESDAY...AND THUS A CHOPPY SEA STATE IS EXPECTED. WAVE
HEIGHTS WILL RISE TO 4-5 FT...AND A SCEC MAY BE NEEDED MUCH OF
MONDAY. WINDS WILL SHIFT QUICKLY TO THE W AND THEN NW BEHIND THE
FRONT TUESDAY MORNING...AND THEN SLOWLY DECREASE IN SPEED FROM
10-15 KTS...TO AROUND 5 KTS AS HIGH PRESSURE BUILDS TOWARDS THE
AREA REDUCING THE PRESSURE GRADIENT. SEAS WILL FALL INITIALLY ON
THE OFFSHORE WIND TO 2-4 FT...BEFORE DROPPING FURTHER TO 1-2 FT
TUESDAY NIGHT.
LONG TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 300 AM SUNDAY...BROAD HIGH PRESSURE WILL SKIRT ACROSS THE
WATERS AND OFFSHORE WEDNESDAY...SO LIGHT AND VARIABLE WINDS WILL
GRADUALLY TRANSITION TO A SW DIRECTION WEDNESDAY NIGHT AS RETURN
FLOW DEVELOPS. THIS SW FLOW WILL PERSIST MOST OF THURSDAY BUT WITH
SPEEDS INCREASING TO 10-15 KTS AHEAD OF A COLD FRONT WHICH WILL
CROSS THE WATERS AT THE END OF THE PERIOD. WAVE HEIGHTS OF 1-2 FT
WILL BUILD SLOWLY ONCE THE WIND BECOMES PREDOMINANTLY FROM THE SW
LATE WEDNESDAY...AND THEN CONTINUE TO SLOWLY RISE THURSDAY TO 3-4
FT BEFORE THE COLD FRONTAL PASSAGE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...MJC
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...DL
MARINE...TRA/JDW
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
117 PM EDT SUN APR 19 2015
.SYNOPSIS...
HIGH PRESSURE EXTENDING OVER THE AREA FROM THE NORTH WILL SHIFT
OFFSHORE TODAY. A WARM FRONT WILL LIFT NORTHEAST ACROSS THE AREA
TONIGHT AS LOW PRESSURE MOVES INTO THE OHIO VALLEY. A COLD FRONT
WILL MOVE THROUGH FROM THE WEST EARLY TUESDAY FOLLOWED BY HIGH
PRESSURE WEDNESDAY. ANOTHER COLD FRONT WILL MOVE IN FROM THE
NORTHWEST THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 110 PM SUNDAY...FORECAST PRETTY MUCH ON TRACK WITH A
MODERATE TO HEAVY SHOWERS DRIFTING IN FROM THE OCEAN AND THE
LEADING EDGE OF THE WIDESPREAD RAIN SHIELD IS MOVING INTO SOUTH
CENTRAL NORTH CAROLINA. GENERALLY FOLLOWED THE 3KM HRRR WHICH IS
DOING A GOOD JOB OF DEPICTING THE RAINFALL. NO CHANGES THROUGH THE
AFTERNOON AS RAIN BECOMES WIDESPREAD AND STEADY. CONVECTIVE
DEVELOPMENT POTENTIAL SEEMS LIMITED BASED ON CURRENT PARAMETERS AS
BEST INSTABILITY OCCURRING MUCH FURTHER SOUTHWEST ACROSS
GEORGIA...ALABAMA AND THE FLORIDA PANHANDLE. NO CHANGE TO
TEMPERATURE FORECAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
AS OF 400 AM SUNDAY...LATEST GDNC CONTINUES TO INDICATE WET
CONDITIONS TONIGHT AND INCREASED POPS TO 100% ALL ZONES. DIFFLUENT
UPR FLOW AHEAD OF UPR TROF LIFTING OUT OF SRN PLAINS WILL INDUCE
LARGE SCALE ASCENT ACROSS AREA ALONG WITH DEEP MSTR PLUME FROM
GULFMEX. SFC WARM FRONT WILL APPROACH FROM SW AS DEVELOPING LOW
PRES MOVES INTO WRN OH VLY. WDSPRD SHOWERS AND PSBLY SCT TSTMS
EXPECTED TO GRADUALLY SPREAD SW TO NE ACROSS ERN NC OVERNIGHT. QPF
LOWERED SLIGHTLY BASED ON HPC AND LATEST MODEL BLEND...BUT MOST
AREAS STILL SEEING 1/2 TO 1 INCH.
PER NEAR-TERM...MARGINAL SVR THREAT FOR SW SECTIONS WITH SOME
POTENTIAL FOR ROTATING STORMS ALONG AND AHEAD OF WARM FRONT.
GENERALLY A HIGH SHEAR/LOW CAPE THREAT WITH WDSPRD CLOUDS AND PCPN
LIMITING INSTABILITY.
MIN TEMPS MAINLY LOW-MID 60S EVEN WITH WDSPRD RAIN.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
AS OF 350 AM SUNDAY...BY MONDAY, THE UPPER TROUGH WILL SHIFT
EAST NEAR THE GREAT LAKES REGION WITH SEVERAL SHORTWAVES/
VORTICITY MAXIMA ROTATING AROUND THE BASE OF THE UPPER TROUGH. THE
SURFACE LOW WILL MOVE NORTHEAST INTO SOUTHEASTERN CANADA WITH THE
ATTENDANT COLD FRONT WELL NORTH OF THE REGION. THE BEST LIFT FROM
THE NORTHERN STREAM LIFTS WELL NORTH OF THE AREA WHILE THE
SOUTHERN STREAM JET REMAINS WELL SOUTHWEST OF EASTERN NC. THE BEST
MOISTURE ALSO LIFTS WELL NORTH OF EASTERN NC WITH FORECAST
SOUNDINGS INDICATING PWATS FALLING TO 1.20 INCHES MONDAY
AFTERNOON. GUIDANCE IS IN GOOD AGREEMENT WITH A SHORTWAVE/VORT MAX
MOVING THROUGH EASTERN NC MONDAY AFTERNOON/EVENING WHICH COULD
HELP SUPPORT OR ENHANCE ONGOING CONVECTION. 500 MB TEMPS FALL
FROM AROUND -11/-12 C SUNDAY TO -15/-16 C MONDAY AFTERNOON
INDICATING A FAVORABLE ENVIRONMENT FOR LARGE HAIL SHOULD STORMS
BECOME SEVERE. GIVEN SOUTHWESTERLY UNIDIRECTIONAL SHEAR, CAN ALSO
EXPECT A FEW SHOWERS/THUNDERSTORMS ALONG THE INLAND MOVING SEA-
BREEZE. AS DRY SLOTTING DEVELOPS MONDAY MORNING, CLOUD COVER WILL
DIMINISH ALLOWING EXCELLENT INSOLATION. INSTABILITY WILL BE
PLENTIFUL THOUGH THE ENVIRONMENT WILL A TRIGGER FOR CONVECTIVE
INITIATION, AND LACK VEERING LOW LEVEL WINDS. SPC MAINTAINS A
SLIGHT RISK FOR EASTERN NC THROUGH MONDAY EVENING/NIGHT. BIGGEST
THREAT WILL BE LARGE HAIL AND DAMAGING WIND GUSTS, THOUGH AN
ISOLATED TORNADO CANNOT BE RULED OUT.
INCREASED POPS TO CHANCE INLAND MONDAY AFTERNOON. HIGHS MONDAY
WILL BE IN THE LOW 80S INLAND AND MID 70S BEACHES.
MONDAY NIGHT/TUESDAY...COLD FRONT MOVES OFFSHORE LATE MONDAY NIGHT
AND EARLY TUESDAY MORNING WITH SLIGHTLY COOLER AND DRIER AIR
MOVING IN. TUESDAY`S HIGHS SHOULD BE IN THE MID 70S...BUT WITH
DEWPOINTS DOWN IN THE LOWER 50S BY AFTERNOON.
TUESDAY NIGHT/WEDNESDAY...HIGH PRESSURE BUILDS OVERHEAD WITH
MAINLY HIGH CLOUDS WEDNESDAY. COOL MORNING LOWS AROUND 50 REBOUND
TO AFTERNOON HIGHS IN THE MID 70S.
WEDNESDAY NIGHT/THURSDAY...ZONAL FLOW ALOFT CONTINUES AS A COLD
FRONT CROSSES THE REGION LATE THURSDAY. GUIDANCE IN MODEST
AGREEMENT FOR LIGHT SHOWERS/THUNDERSTORMS THURSDAY, THUS HAVE
INTRODUCED SLIGHT CHANCE POP WITH FRONTAL PASSAGE. ANOTHER COOL
MORNING THURSDAY WITH LOWS 50 TO 55...REBOUNDING INTO THE UPPER
70S THURSDAY AFTERNOON.
THURSDAY NIGHT/FRIDAY...DRY WEATHER BEHIND THE FRONT WITH SUNNY
COOLER WEATHER FOR FRIDAY. LOWS AGAIN IN THE 50 TO 55 DEGREE
RANGE WITH HIGHS UPPER 60S FAR NORTHEAST AND LOW 70S ELSEWHERE.
FRIDAY NIGHT/SATURDAY...ANOTHER SOUTHERN STREAM SYSTEM APPROACHES
LATE SATURDAY. HAVE INDICATED INCREASED CLOUD COVER AND A SMALL
CHANCE OF RAIN IN THE AFTERNOON.
&&
.AVIATION /17Z SUNDAY THROUGH THURSDAY/...
SHORT TERM /THROUGH 12Z MONDAY/...
AS OF 700 AM SUNDAY...LIFT STRATUS CIGS DEVELOPED ALL TAF SITES
10-11Z WITH LIFR VSBYS AS WELL AT KPGV AND KISO. CONDITIONS
EXPECTED TO LIFT TO VFR BY AROUND 13Z. VFR PERSISTING INTO EARLY
AFTN...THEN CONDITIONS DETERIORATING. WIDESPREAD SHOWERS/ISOLD
TSTMS EXPECTED TO DEVELOP AND SPREAD SW TO NE ACROSS AREA THIS
AFTN INTO EARLY EVENING...WITH WDSPRD IFR CIGS LIKELY ALL TAF
SITES BY 00Z AND PERSISTING OVERNIGHT WITH VSBYS 3-5 SM IN SHRA.
LIGHT WINDS THIS MORNING WILL BECOME SE 10-15 KT THIS AFTN INTO
EVENING.
LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 355 AM SUNDAY...PRECIPITATION DIMINISHES MONDAY BUT SOME
ISOLATED STRONG TO SEVERE TSTMS MAY BE POSSIBLE, ESPECIALLY KPGV
AND KISO, MONDAY AFTERNOON AND EVENING WHICH COULD PRODUCE SUB-VFR
AVIATION CONDITIONS. HIGH PRESSURE BUILDS IN ACROSS EASTERN NC
TUESDAY INTO WEDNESDAY YIELDING MOSTLY VFR CONDITIONS. A WEAK
FRONT WILL MOVE SOUTH INTO EASTERN NC THURSDAY BUT WITH LIMITED
MOISTURE SO EXPECT MOSTLY VFR CONDITIONS THURSDAY.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 115 PM SUNDAY...WINDS HAVE DROPPED A BIT FROM THIS MORNING
WITH GENERALLY E/NE WIND 10 TO 15 KNOTS WITH SOME GUSTS TO AROUND
21 KNOTS AT DIAMOND SHOALS. SEAS STILL 3 TO 5 FEET WITH LONG
PERIOD SWELLS OVER THE CENTRAL AND NORTHERN WATERS. WINDS BECOME
SE LATER TODAY AS WARM FRONT LIFTS NORTH. WINDS INCREASE TO 15 TO
20 KNOTS BY THIS EVENING. PRES GRAD WILL TIGHTEN TONIGHT WITH WARM
FRONT MOVING IN FROM SW...RESULTING IN WINDS BECOMING S-SW 20-25
KT. SEAS BUILDING TO 4-6 FT OUTER WATERS LATE TODAY AND PEAKING
6-8 FT LATE TONIGHT.
LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 355 AM SUNDAY...GUSTY S/SW WINDS WILL BUILD SEAS TO 7-8 FEET
MONDAY. SEAS WILL REMAIN ELEVATED INTO TUESDAY MORNING AND CURRENT
SCA FOR ALL COASTAL WATERS WILL REMAIN IN EFFECT UNTIL 12Z TUESDAY.
HIGH PRESSURE WILL BUILD OVER THE NC WATERS TUESDAY INTO WEDNESDAY
WITH WINDS SHIFTING MORE WESTERLY, 5-15 KT. SEAS WILL DIMINISH TO
2-4 FT TUESDAY NIGHT THROUGH WEDNESDAY. A COLD FRONT WILL MOVE
SOUTH INTO THE NORTHERN WATERS THURSDAY AND SHIFT SOUTH OF THE
WATERS THURSDAY NIGHT. WINDS VEER NORTHWEST BEHIND THE FRONT BUT
REMAIN 5-15 KT WITH SEAS 2-4 FEET.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO 8 AM EDT
TUESDAY FOR AMZ150-152-154-156-158.
&&
$$
SYNOPSIS...JBM
NEAR TERM...CTC
SHORT TERM...JBM
LONG TERM...DAG
AVIATION...JBM/DAG
MARINE...CTC/JBM/DAG
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
930 AM EDT SUN APR 19 2015
.SYNOPSIS...
HIGH PRESSURE EXTENDING OVER THE AREA FROM THE NORTH WILL SHIFT
OFFSHORE TODAY. A WARM FRONT WILL LIFT NORTHEAST ACROSS THE AREA
TONIGHT AS LOW PRESSURE MOVES INTO THE OHIO VALLEY. A COLD FRONT
WILL MOVE THROUGH FROM THE WEST EARLY TUESDAY FOLLOWED BY HIGH
PRESSURE WEDNESDAY. ANOTHER COLD FRONT WILL MOVE IN FROM THE
NORTHWEST THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 925 AM SUNDAY...MADE SOME SLIGHT ADJUSTMENTS TO NEAR-TERM
POPS AS LEADING EDGE OF PRECIPITATION SHIELD NOW MOVING INTO
NORTHEAST SOUTH CAROLINA AND WILL LIKELY BE A FEW MORE HOURS UNTIL
IT ARRIVES IN OUR CWA. THERE ARE A FEW ISOLATED SHOWERS OCCURRING
INLAND DUE TO SOME WEAK ISENTROPIC LIFT. GENERALLY FOLLOWED THE
3KM HRRR WHICH IS DOING A GOOD JOB OF DEPICTING THE RAINFALL. NO
CHANGES THROUGH THE AFTERNOON AS RAIN BECOMES WIDESPREAD AND
STEADY. CONVECTIVE DEVELOPMENT POTENTIAL SEEMS LIMITED BASED ON
CURRENT PARAMETERS AS BEST INSTABILITY OCCURRING MUCH FURTHER
SOUTHWEST ACROSS GEORGIA...ALABAMA AND THE FLORIDA PANHANDLE. NO
CHANGE TO TEMPERATURE FORECAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
AS OF 400 AM SUNDAY...LATEST GDNC CONTINUES TO INDICATE WET
CONDITIONS TONIGHT AND INCREASED POPS TO 100% ALL ZONES. DIFFLUENT
UPR FLOW AHEAD OF UPR TROF LIFTING OUT OF SRN PLAINS WILL INDUCE
LARGE SCALE ASCENT ACROSS AREA ALONG WITH DEEP MSTR PLUME FROM
GULFMEX. SFC WARM FRONT WILL APPROACH FROM SW AS DEVELOPING LOW
PRES MOVES INTO WRN OH VLY. WDSPRD SHOWERS AND PSBLY SCT TSTMS
EXPECTED TO GRADUALLY SPREAD SW TO NE ACROSS ERN NC OVERNIGHT. QPF
LOWERED SLIGHTLY BASED ON HPC AND LATEST MODEL BLEND...BUT MOST
AREAS STILL SEEING 1/2 TO 1 INCH.
PER NEAR-TERM...MARGINAL SVR THREAT FOR SW SECTIONS WITH SOME
POTENTIAL FOR ROTATING STORMS ALONG AND AHEAD OF WARM FRONT.
GENERALLY A HIGH SHEAR/LOW CAPE THREAT WITH WDSPRD CLOUDS AND PCPN
LIMITING INSTABILITY.
MIN TEMPS MAINLY LOW-MID 60S EVEN WITH WDSPRD RAIN.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
AS OF 350 AM SUNDAY...BY MONDAY, THE UPPER TROUGH WILL SHIFT
EAST NEAR THE GREAT LAKES REGION WITH SEVERAL SHORTWAVES/
VORTICITY MAXIMA ROTATING AROUND THE BASE OF THE UPPER TROUGH. THE
SURFACE LOW WILL MOVE NORTHEAST INTO SOUTHEASTERN CANADA WITH THE
ATTENDANT COLD FRONT WELL NORTH OF THE REGION. THE BEST LIFT FROM
THE NORTHERN STREAM LIFTS WELL NORTH OF THE AREA WHILE THE
SOUTHERN STREAM JET REMAINS WELL SOUTHWEST OF EASTERN NC. THE BEST
MOISTURE ALSO LIFTS WELL NORTH OF EASTERN NC WITH FORECAST
SOUNDINGS INDICATING PWATS FALLING TO 1.20 INCHES MONDAY
AFTERNOON. GUIDANCE IS IN GOOD AGREEMENT WITH A SHORTWAVE/VORT MAX
MOVING THROUGH EASTERN NC MONDAY AFTERNOON/EVENING WHICH COULD
HELP SUPPORT OR ENHANCE ONGOING CONVECTION. 500 MB TEMPS FALL
FROM AROUND -11/-12 C SUNDAY TO -15/-16 C MONDAY AFTERNOON
INDICATING A FAVORABLE ENVIRONMENT FOR LARGE HAIL SHOULD STORMS
BECOME SEVERE. GIVEN SOUTHWESTERLY UNIDIRECTIONAL SHEAR, CAN ALSO
EXPECT A FEW SHOWERS/THUNDERSTORMS ALONG THE INLAND MOVING SEA-
BREEZE. AS DRY SLOTTING DEVELOPS MONDAY MORNING, CLOUD COVER WILL
DIMINISH ALLOWING EXCELLENT INSOLATION. INSTABILITY WILL BE
PLENTIFUL THOUGH THE ENVIRONMENT WILL A TRIGGER FOR CONVECTIVE
INITIATION, AND LACK VEERING LOW LEVEL WINDS. SPC MAINTAINS A
SLIGHT RISK FOR EASTERN NC THROUGH MONDAY EVENING/NIGHT. BIGGEST
THREAT WILL BE LARGE HAIL AND DAMAGING WIND GUSTS, THOUGH AN
ISOLATED TORNADO CANNOT BE RULED OUT.
INCREASED POPS TO CHANCE INLAND MONDAY AFTERNOON. HIGHS MONDAY
WILL BE IN THE LOW 80S INLAND AND MID 70S BEACHES.
MONDAY NIGHT/TUESDAY...COLD FRONT MOVES OFFSHORE LATE MONDAY NIGHT
AND EARLY TUESDAY MORNING WITH SLIGHTLY COOLER AND DRIER AIR
MOVING IN. TUESDAY`S HIGHS SHOULD BE IN THE MID 70S...BUT WITH
DEWPOINTS DOWN IN THE LOWER 50S BY AFTERNOON.
TUESDAY NIGHT/WEDNESDAY...HIGH PRESSURE BUILDS OVERHEAD WITH
MAINLY HIGH CLOUDS WEDNESDAY. COOL MORNING LOWS AROUND 50 REBOUND
TO AFTERNOON HIGHS IN THE MID 70S.
WEDNESDAY NIGHT/THURSDAY...ZONAL FLOW ALOFT CONTINUES AS A COLD
FRONT CROSSES THE REGION LATE THURSDAY. GUIDANCE IN MODEST
AGREEMENT FOR LIGHT SHOWERS/THUNDERSTORMS THURSDAY, THUS HAVE
INTRODUCED SLIGHT CHANCE POP WITH FRONTAL PASSAGE. ANOTHER COOL
MORNING THURSDAY WITH LOWS 50 TO 55...REBOUNDING INTO THE UPPER
70S THURSDAY AFTERNOON.
THURSDAY NIGHT/FRIDAY...DRY WEATHER BEHIND THE FRONT WITH SUNNY
COOLER WEATHER FOR FRIDAY. LOWS AGAIN IN THE 50 TO 55 DEGREE
RANGE WITH HIGHS UPPER 60S FAR NORTHEAST AND LOW 70S ELSEWHERE.
FRIDAY NIGHT/SATURDAY...ANOTHER SOUTHERN STREAM SYSTEM APPROACHES
LATE SATURDAY. HAVE INDICATED INCREASED CLOUD COVER AND A SMALL
CHANCE OF RAIN IN THE AFTERNOON.
&&
.AVIATION /13Z SUNDAY THROUGH THURSDAY/...
SHORT TERM /THROUGH 12Z MONDAY/...
AS OF 700 AM SUNDAY...LIFT STRATUS CIGS DEVELOPED ALL TAF SITES
10-11Z WITH LIFR VSBYS AS WELL AT KPGV AND KISO. CONDITIONS
EXPECTED TO LIFT TO VFR BY AROUND 13Z. VFR PERSISTING INTO EARLY
AFTN...THEN CONDITIONS DETERIORATING. WIDESPREAD SHOWERS/ISOLD
TSTMS EXPECTED TO DEVELOP AND SPREAD SW TO NE ACROSS AREA THIS
AFTN INTO EARLY EVENING...WITH WDSPRD IFR CIGS LIKELY ALL TAF
SITES BY 00Z AND PERSISTING OVERNIGHT WITH VSBYS 3-5 SM IN SHRA.
LIGHT WINDS THIS MORNING WILL BECOME SE 10-15 KT THIS AFTN INTO
EVENING.
LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 355 AM SUNDAY...PRECIPITATION DIMINISHES MONDAY BUT SOME
ISOLATED STRONG TO SEVERE TSTMS MAY BE POSSIBLE, ESPECIALLY KPGV
AND KISO, MONDAY AFTERNOON AND EVENING WHICH COULD PRODUCE SUB-VFR
AVIATION CONDITIONS. HIGH PRESSURE BUILDS IN ACROSS EASTERN NC
TUESDAY INTO WEDNESDAY YIELDING MOSTLY VFR CONDITIONS. A WEAK
FRONT WILL MOVE SOUTH INTO EASTERN NC THURSDAY BUT WITH LIMITED
MOISTURE SO EXPECT MOSTLY VFR CONDITIONS THURSDAY.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 930 AM SUNDAY...NO MAJOR CHANGES TO THE CURRENT FORECAST
WITH LIGHT NORTHEAST WINDS INTO EARLY AFTERNOON...BECOMING E-SE AS
WARM FRONT LIFTS NORTH. WINDS INCREASE TO 15 TO 20 KNOTS BY THIS
EVENING. PRES GRAD WILL TIGHTEN TONIGHT WITH WARM FRONT MOVING IN
FROM SW...RESULTING IN WINDS BECOMING S-SW 20-25 KT. SEAS BUILDING
TO 4-6 FT OUTER WATERS LATE TODAY AND PEAKING 6-8 FT LATE TONIGHT.
LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 355 AM SUNDAY...GUSTY S/SW WINDS WILL BUILD SEAS TO 7-8 FEET
MONDAY. SEAS WILL REMAIN ELEVATED INTO TUESDAY MORNING AND CURRENT
SCA FOR ALL COASTAL WATERS WILL REMAIN IN EFFECT UNTIL 12Z TUESDAY.
HIGH PRESSURE WILL BUILD OVER THE NC WATERS TUESDAY INTO WEDNESDAY
WITH WINDS SHIFTING MORE WESTERLY, 5-15 KT. SEAS WILL DIMINISH TO
2-4 FT TUESDAY NIGHT THROUGH WEDNESDAY. A COLD FRONT WILL MOVE
SOUTH INTO THE NORTHERN WATERS THURSDAY AND SHIFT SOUTH OF THE
WATERS THURSDAY NIGHT. WINDS VEER NORTHWEST BEHIND THE FRONT BUT
REMAIN 5-15 KT WITH SEAS 2-4 FEET.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO 8 AM EDT
TUESDAY FOR AMZ150-152-154-156-158.
&&
$$
SYNOPSIS...JBM
NEAR TERM...CTC
SHORT TERM...JBM
LONG TERM...DAG
AVIATION...JBM/DAG
MARINE...CTC/JBM/DAG
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
121 AM EDT SUN APR 19 2015
.SYNOPSIS...
AN APPROACHING FRONTAL SYSTEM WILL BRING SHOWERS AND A CHANCE OF
THUNDERSTORMS TODAY THROUGH MONDAY. A FEW STORMS COULD BE STRONG TO
SEVERE MONDAY. DRY AND SEASONABLE HIGH PRESSURE WILL BUILD INTO THE
AREA TUESDAY AND WEDNESDAY. A WEAK COLD FRONT MAY BRING SHOWERS AND
ISOLATED THUNDERSTORMS INTO LATE WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 130 AM SUNDAY...WE`RE PROBABLY AT A CONVECTIVE MINIMUM RIGHT
NOW. LATEST HRRR AND HRRRX MODELS SHOW AN INCREASE IN SHOWER
ACTIVITY LATE TONIGHT...AND ESPECIALLY AROUND DAYBREAK ACROSS THE
PEE DEE REGION AS THE DEVELOPING WARM FRONT AND BETTER UPPER SUPPORT
ARRIVES FROM THE SOUTHWEST. A FEW DOWNWARD TWEAKS HAVE BEEN MADE TO
FORECAST LOW TEMPS NEAR THE COAST. DISCUSSION FROM 1030 PM FOLLOWS...
THE DIURNALLY INDUCED CONVECTION CONTINUES TO DISSIPATE ACROSS THE
FA AND IS NOW BASICALLY WIDELY SCATTERED IN COVERAGE...AND IN THE
FORM OF LIGHT RAIN SHOWERS. WILL DROP POPS TO ISOLATED IN COVERAGE
FOR PORTIONS OF THE ILM CWA BUT ONLY FOR TEMPORARILY THIS EVENING UP
TO A FEW HRS AFTER MIDNIGHT. WITH A SFC COLD FRONTAL BOUNDARY
DROPPING SOUTH AND POSSIBLY BACKDOORING THE FA OVERNIGHT BEFORE
TEMPORARILY STALLING...AND A FEW LEFTOVER SHALLOW MESOSCALE SFC
BOUNDARIES PRESENT. WILL NOT ENTIRELY REMOVE PCPN FOR THE REMAINDER
OF THE OVERNIGHT.
IN FACT...DURING THE PRE-DAWN HRS OF SUNDAY THRU DAYBREAK...LOOK
FOR POPS TO RAMP BACK UP ACROSS THE ILM CWA FROM SW TO NE...WITH A
GOOD CHANCE OR POSSIBLY LIKELY ACROSS THE SW PORTIONS BY SUNRISE
SUN. INCREASING MID-LEVEL DYNAMICS FROM A SERIES OF S/W MID-LEVEL
TROUGHS...PLENTY OF AVBL MOISTURE WITH 00Z SUNDAY NEARBY SOUNDINGS
AND MODEL PROGS INDICATING PWS OF 1.5 TO 1.75 INCHES...AND AS
MENTIONED EARLIER...SFC BASED BOUNDARIES WILL LIE ACROSS THE FA
ALLOWING FOR SFC BASED CONVERGENCE TO AID MORE ORGANIZED PCPN
DEVELOPMENT TO COMPLEMENT THE MID-LEVEL SUPPORT. LATEST MIN TEMPS
FORECAST OVERNIGHT LOOKING AOK AND SEE NO REASON TO FURTHER TWEAK
FROM EARLIER CHANGES.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
AS OF 3 PM SATURDAY...PRIMARY HEADLINES INCLUDE POTENTIAL FOR A
GOOD SOAKING OF RAIN...AND A FEW STRONG THUNDERSTORMS. MONDAY
APPEARS THE MORE OPTIMUM SET-UP FOR STRONG/SEVERE STORMS WITH MORE
ROBUST KINEMATIC FIELDS AND STRONGER LOW-LEVEL HEATING JUST AHEAD
OF A COLD FRONT. EXTENSIVE CLOUD CANOPY SUNDAY MAY IMPEDE
CONVECTION INITIATION/GROWTH. SUNDAY MEANWHILE OFFERS THE HIGHER
RAIN AMOUNTS AS COLUMN MOISTURE SURGES AS A WARM FRONT LIFTS N OF
THE AREA AND PRECIPITABLE WATERS SURGE TO 1.8". SEVERAL MCV
PERTURBATIONS ALOFT SWEPT NE IN WAKE OF THE WARM FRONT MAY SUSTAIN
SHOWER AND STORM CHANCES INTO SUNDAY NIGHT. CURRENT IR ANIMATIONS
SHOW COLD TOPS INDEED FLARING ALONG THE NORTHERN GULF OF MEXICO.
WPC QPF DEPICTIONS SHOW .75-1 INCH BASIN AVERAGES SUNDAY...AND
WITH CONVECTIVE ELEMENTS...SOME AREAS LIKELY TO RECEIVE GREATER
AMOUNTS. MONDAY LESS BASIN QPF BUT MORE POWERFUL STORMS IN THE
CARDS WITH MAXIMUMS RISING WELL INTO THE 80S AND PARTIAL SUNSHINE
AIDING INSOLATION AND CELL POPS. SPC PAINTS SLIGHT RISK FOR BOTH
LATE SUNDAY AND MONDAY. BALMY PERIOD OVERALL AND BEST GUESS ON
FRONTAL PASSAGE NOW SLATED AROUND OR AFTER DAYBREAK TUESDAY.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 3 PM SATURDAY...AN ALMOST WINTERLIKE LOOKING UPPER PATTERN
FOR MOST OF THE PERIOD WITH A LARGE VORTEX IN THE VICINITY OF THE
GREAT LAKES. WESTERLY FLOW AROUND THIS FEATURE WILL KEEP MUCH OF THE
COLUMN DRY AND LEAD TO RAIN-FREE CONDITIONS LOCALLY. LOW LEVELS WILL
BE DRY AS WELL THROUGH SOME TIME WEDNESDAY AS HIGH PRESSURE BUILDS
IN FROM THE NORTHWEST. SOON THEREAFTER THIS HIGH MOVES OFFSHORE AND
SOME MOISTENING RETURN FLOW ENSUES. SOME GUIDANCE SHOWING THIS
CALLING FOR RAIN AS SOON AS THURSDAY BUT GIVEN THE AFOREMENTIONED
DOWNSLOPE FLOW STILL FEEL THAT THURSDAY NIGHT INTO FRIDAY IS THE
BETTER DAY TO INTRODUCE SOME RAIN CHANCES ESPECIALLY GIVEN THE
APPROACH OF A COLD FRONT. THOUGH THIS SURFACE BOUNDARY MAY LIE TO
OUR SOUTH ON SATURDAY SOME LOW LEVEL BAROCLINICITY PAIRED WITH MID
LEVEL VORT APPROACHING TO KEEP RAIN IN THE FORECAST.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 06Z...A MIXTURE OF VFR/MVFR THROUGH THE EARLY OVERNIGHT HOURS
DUE TO LOW CIGS AND PATCHY FOG...WITH CONDITIONS DETERIORATING TO
MVFR/IFR LATE OVERNIGHT AND THROUGH INTO SUNDAY WITH AN APPROACHING
FRONTAL SYSTEM.
OVERALL...VFR PREVAILS ACROSS THE AREA TONIGHT WITH LIGHT AND
VARIABLE WINDS AND INTERMITTENT LOW CIGS...AS WELL AS MID TO HIGH
CLOUDS AS SEEN FROM LATEST SATELLITE IMAGERY. OBSERVATIONS ARE ALSO
DEPICTING PATCHY FOG INLAND...JUST AT MARGINAL VFR/MVFR STATUS ATTM.
WITH ISOLATED LIGHT SHOWERS SLOWLY MOVING ACROSS THE
AREA...ANTICIPATE CONDITIONS TO DETERIORATE OVERNIGHT CREATING
WIDESPREAD MVFR/IFR DUE TO LOW CIGS AND AREAS OF FOG. AFTER
DAYBREAK...EXPECT EASTERLY WINDS AOB 12 KTS IN THE MORNING TO BECOME
EAST-SOUTHEAST BY AFTERNOON WITH GUSTS UP NEAR 20 KTS POSSIBLE WITH
A FRONTAL SYSTEM TO AFFECT THE AREA. A MIXTURE OF VFR/MVFR/IFR IS
ANTICIPATED AS SHOWERS AND ISOLATED THUNDERSTORMS...ALONG WITH LOW
CIGS AND PATCHY AREAS OF FOG MOVE THROUGHOUT THE AREA THROUGH THE
END OF THE VALID TAF PERIOD.
EXTENDED OUTLOOK...MVFR/IFR POSSIBLE INTO MONDAY WITH SHOWERS AND
ISOLATED THUNDERSTORMS. A COLD FRONT WILL PUSH THROUGH THE AREA
MONDAY NIGHT WITH SHOWERS POSSIBLE FOLLOWED BY MAINLY VFR CONDITIONS
TUESDAY. POSSIBLE SHOWERS RETURNING LATER IN THE WEEK.
&&
.MARINE... NEAR TERM /THROUGH TONIGHT/...
AS OF 130 AM SUNDAY...BASED ON OBSERVATIONS ALONG THE COAST I HAVE
BACKED WIND DIRECTIONS MORE NORTHERLY. NO OTHER SIGNIFICANT CHANGES
ARE NEEDED. DISCUSSION FROM 1030 PM FOLLOWS...
NO CHANGES TO THE WINDS FROM THE PREVIOUS UPDATE. WINDS TO BECOME NE-
E THROUGHOUT...AND INCREASE TO 10-15 KT...WITH THE HIGHER WIND SPEEDS
FROM CAPE FEAR NORTHWARD. THIS A RESULT OF THE BACKDOOR FRONTS
POSITIONING WITH ENOUGH TIGHTENING OF THE SFC PG AS RIDGING EXTENDS
SOUTH FROM THE NE STATES SFC HIGH. SIGNIFICANT SEAS WILL RUN 2 TO 4
FT...WITH THE 4 FOOTERS PRIMARILY ACROSS THE OUTER WATERS OFF CAPE
FEAR...AND NORTHWARD. DOMINANT PERIODS WILL RUN 8 TO 9 SECONDS IN
RESPONSE TO THE 2 TO 3 FOOT ESE GROUND SWELL. HAVE REDUCED THE POPS
FOR THIS EVENING BASED ON LATEST 88D TRENDS. SHOULD SEE POPS
INCREASE DURING THE PRE-DAWN SUN HRS.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 PM SATURDAY...EXERCISE CAUTION OR ADVISORY MARINE REGIME
ON TAP THIS PERIOD AS A FRONTAL SYSTEM APPROACHES AND WORSENS
LOCAL MARINE CONDITIONS. WAVE GROWTH HOWEVER MAY BE LIMITED SINCE
SE-S WIND FLOW HAS LIMITED STAYING TIME BEFORE WINDS GO SW EARLY
ON MONDAY. HAVE CAPPED SEAS AT 5 FEET SUNDAY FOR NOW WITH GUSTS TO
20 KT AHEAD OF THE COLD FRONT...SET TO CROSS THE WATERS TUESDAY
MORNING. SEVERAL STRONG TSTMS ARE POSSIBLE SUNDAY THROUGH THROUGH
EARLY TUESDAY AND SPECIAL MARINE WARNINGS MAY BE NEEDED AT TIMES.
LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 3 PM SATURDAY...OFFSHORE/NORTHWESTERLY POST COLD FRONTAL
FLOW REGIME ON TUESDAY WILL GROW LIGHTER LATE IN THE DAY AND AT
NIGHT AS CENTER OF HIGH PRESSURE APPROACHES. THE CENTER OF HIGH
PRESSURE MOVES OFFSHORE BY WEDNESDAY EVENING. THIS WILL BRING A
PERIOD OF VERY LIGHT GRADIENT WHEREIN WINDS REMAIN UNDER 10 KNOTS
AND VEER IN DIRECTION FOR AN EXTENDED TIME UNTIL FINALLY SETTLING
ON SOUTHERLY BY WED EVE. SUCH LIGHT WINDS IN THE ABSENCE OF SWELL
ENERGY OUGHT TO BE GOOD FOR MINIMAL SEAS OF 2 FT OR LESS. THE HIGH
MOVES FURTHER OFFSHORE ON THURSDAY ALLOWING FOR A ONE CATEGORY
RISE IN WINDS AND A WAVES FORECAST RISING TO JUST THE 2 TO 3 FT
RANGE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MJC
NEAR TERM...DCH/TRA
SHORT TERM...MJC
LONG TERM...MBB
AVIATION...SGL
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1203 PM CDT SUN APR 19 2015
.UPDATE...
ISSUED AT 1202 PM CDT SUN APR 19 2015
QUICK UPDATE TO ADD A MENTION OF ISOLATED THUNDERSTORMS THIS
AFTERNOON WITH SMALL HAIL BEING REPORTED ACROSS MUCH OF WESTERN
AND CENTRAL NORTH DAKOTA WITH SHALLOW CONVECTION ASSOCIATED WITH COOL
TEMPERATURES ALOFT.
UPDATE ISSUED AT 929 AM CDT SUN APR 19 2015
THE FORECAST FOR THE REMAINDER OF TODAY IS ON TRACK WITH THE
STRATUS FIELD OVERTAKING WESTERN AND CENTRAL NORTH DAKOTA EXPECTED
TO SLOWLY SCATTER WITH DIURNAL HEATING WITH RAIN SHOWER COVERAGE
INCREASING THROUGH THE AFTERNOON. THIS IS IN LINE WITH THE 12-13
UTC HRRR ITERATIONS.
UPDATE ISSUED AT 629 AM CDT SUN APR 19 2015
INITIAL BATCH OF WIDESPREAD RAIN CONTINUES TO PUSH OFF TO THE
EAST...THOUGH SECONDARY ROUND OF SCATTERED WRAP AROUND SHOWERS ARE
STARTING TO DEVELOP AND WORK INTO FAR NORTHWEST NORTH DAKOTA. HAVE
ADJUSTED POPS TO ACCOUNT FOR THIS. HAVE ALSO INCREASED CLOUD COVER
MAINLY OVER THE WEST AS CLOUDS CONTINUE TO STREAM IN BEHIND THE
LOW.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 400 AM CDT SUN APR 19 2015
CONTINUED CHANCES FOR RAIN AND WINDY CONDITIONS THROUGH
SUNDAY...HIGHLIGHT THE SHORT TERM.
AN UPPER LEVEL TROUGH OVER THE NORTHERN PLAINS WILL CONTINUE TO
PROVIDE AMPLE MOISTURE AND INSTABILITY...PROLONGING CHANCES FOR
WIDESPREAD SHOWERS IN CENTRAL AND EASTERN AREAS OF THE STATE THROUGH
THE DAY. ADDITIONALLY...TEMPERATURES SLIGHTLY BELOW AVERAGE AND
STRONG NORTHWEST WINDS WILL ACCOMPANY THE DEEPENING TROUGH. THE
CURRENT 00Z MODEL SUITE PROVIDES GOOD AGREEMENT ON THE UPPER LEVEL
TROUGH DIGGING AND SLOWLY MOVING EASTWARD...PUSHING OVER
MINNESOTA/EASTERN MANITOBA AND CLOSING OFF BY 12Z MONDAY. NORTH
CENTRAL NORTH DAKOTA INTO THE JAMES RIVER VALLEY HAVE THE
POTENTIAL FOR A FEW SNOW FLAKES EARLY MONDAY MORNING...AS COLD AIR
FILTERING SOUTHWARD FROM CANADA IS EXPECTED TO DROP OVERNIGHT LOWS
TO JUST BELOW FREEZING.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 400 AM CDT SUN APR 19 2015
UPPER LOW WILL WORK ALONG THE MINNESOTA/ONTARIO BORDER ON MONDAY.
THIS SHOULD KEEP PRECIPITATION TO THE EAST OF OUR AREA THROUGH THE
DAY...THOUGH GUSTY NORTHWEST WINDS WILL CONTINUE IN THE WAKE OF
THE SYSTEM. A FAST MOVING WAVE WILL MOVE IN BEHIND THE SYSTEM LATE
TUESDAY NIGHT INTO EARLY WEDNESDAY WHICH MAY BRING A LITTLE LIGHT
PRECIPITATION TO CENTRAL NORTH DAKOTA...BUT WILL KEEP POPS LOW
WITH LACK OF MUCH MOISTURE TO WORK WITH. QUIET AND COOL CONDITIONS
ARE THEN EXPECTED WITH RIDGING TO THE WEST AND NORTHWESTERLY FLOW
OVER OUR AREA. MODELS START TO DISAGREE WITH THE POSITION OF THE
RIDGE AND WHETHER A FEW UPPER WAVES WILL MAKE IT THROUGH THE AREA
TOWARDS THE END OF THE WEEK. THEREFORE...WILL KEEP ANY
PRECIPITATION CHANCES ON THE LOW SIDE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1202 PM CDT SUN APR 19 2015
MVFR/VFR STRATUS THIS MORNING IS EXPECTED TO SLOWLY LIFT AND
SCATTER INTO THE AFTERNOON WITH RAIN SHOWER COVERAGE ALSO
INCREASING INTO THE AFTERNOON. ISOLATED THUNDERSTORMS WITH SMALL
HAIL ARE POSSIBLE. STRONG NORTHWEST WIND GUSTS OF 30-35 KTS ARE
ALSO FORECAST ACROSS WESTERN AND CENTRAL NORTH DAKOTA TODAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...AC
LONG TERM...JJS
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
929 AM CDT SUN APR 19 2015
.UPDATE...
ISSUED AT 929 AM CDT SUN APR 19 2015
THE FORECAST FOR THE REMAINDER OF TODAY IS ON TRACK WITH THE
STRATUS FIELD OVERTAKING WESTERN AND CENTRAL NORTH DAKOTA EXPECTED
TO SLOWLY SCATTER WITH DIURNAL HEATING WITH RAIN SHOWER COVERAGE
INCREASING THROUGH THE AFTERNOON. THIS IS IN LINE WITH THE 12-13
UTC HRRR ITERATIONS.
UPDATE ISSUED AT 629 AM CDT SUN APR 19 2015
INITIAL BATCH OF WIDESPREAD RAIN CONTINUES TO PUSH OFF TO THE
EAST...THOUGH SECONDARY ROUND OF SCATTERED WRAP AROUND SHOWERS ARE
STARTING TO DEVELOP AND WORK INTO FAR NORTHWEST NORTH DAKOTA. HAVE
ADJUSTED POPS TO ACCOUNT FOR THIS. HAVE ALSO INCREASED CLOUD COVER
MAINLY OVER THE WEST AS CLOUDS CONTINUE TO STREAM IN BEHIND THE
LOW.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 400 AM CDT SUN APR 19 2015
CONTINUED CHANCES FOR RAIN AND WINDY CONDITIONS THROUGH
SUNDAY...HIGHLIGHT THE SHORT TERM.
AN UPPER LEVEL TROUGH OVER THE NORTHERN PLAINS WILL CONTINUE TO
PROVIDE AMPLE MOISTURE AND INSTABILITY...PROLONGING CHANCES FOR
WIDESPREAD SHOWERS IN CENTRAL AND EASTERN AREAS OF THE STATE THROUGH
THE DAY. ADDITIONALLY...TEMPERATURES SLIGHTLY BELOW AVERAGE AND
STRONG NORTHWEST WINDS WILL ACCOMPANY THE DEEPENING TROUGH. THE
CURRENT 00Z MODEL SUITE PROVIDES GOOD AGREEMENT ON THE UPPER LEVEL
TROUGH DIGGING AND SLOWLY MOVING EASTWARD...PUSHING OVER
MINNESOTA/EASTERN MANITOBA AND CLOSING OFF BY 12Z MONDAY. NORTH
CENTRAL NORTH DAKOTA INTO THE JAMES RIVER VALLEY HAVE THE
POTENTIAL FOR A FEW SNOW FLAKES EARLY MONDAY MORNING...AS COLD AIR
FILTERING SOUTHWARD FROM CANADA IS EXPECTED TO DROP OVERNIGHT LOWS
TO JUST BELOW FREEZING.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 400 AM CDT SUN APR 19 2015
UPPER LOW WILL WORK ALONG THE MINNESOTA/ONTARIO BORDER ON MONDAY.
THIS SHOULD KEEP PRECIPITATION TO THE EAST OF OUR AREA THROUGH THE
DAY...THOUGH GUSTY NORTHWEST WINDS WILL CONTINUE IN THE WAKE OF
THE SYSTEM. A FAST MOVING WAVE WILL MOVE IN BEHIND THE SYSTEM LATE
TUESDAY NIGHT INTO EARLY WEDNESDAY WHICH MAY BRING A LITTLE LIGHT
PRECIPITATION TO CENTRAL NORTH DAKOTA...BUT WILL KEEP POPS LOW
WITH LACK OF MUCH MOISTURE TO WORK WITH. QUIET AND COOL CONDITIONS
ARE THEN EXPECTED WITH RIDGING TO THE WEST AND NORTHWESTERLY FLOW
OVER OUR AREA. MODELS START TO DISAGREE WITH THE POSITION OF THE
RIDGE AND WHETHER A FEW UPPER WAVES WILL MAKE IT THROUGH THE AREA
TOWARDS THE END OF THE WEEK. THEREFORE...WILL KEEP ANY
PRECIPITATION CHANCES ON THE LOW SIDE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 925 AM CDT SUN APR 19 2015
MVFR/VFR STRATUS WILL CONTINUE TO SPREAD ACROSS WESTERN AND
CENTRAL NORTH DAKOTA THIS MORNING. THIS DECK IS EXPECTED TO SLOWLY
LIFT AND SCATTER INTO THE AFTERNOON WITH RAIN SHOWER COVERAGE ALSO
INCREASING INTO THE AFTERNOON. STRONG NORTHWEST WIND GUSTS OF
30-35 KTS ARE ALSO FORECAST ACROSS WESTERN AND CENTRAL NORTH
DAKOTA TODAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...AC
LONG TERM...JJS
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1218 AM CDT SUN APR 19 2015
.UPDATE...
ISSUED AT 1218 AM CDT SUN APR 19 2015
NO CHANGES MADE TO THE PREVIOUS FORECAST.
UPDATE ISSUED AT 955 PM CDT SAT APR 18 2015
ALTHOUGH THE 01 UTC RAP/HRRR ARE OVERDOING THE QPF IN MOST
AREAS...THEY HAVE A GOOD HANDLE ON THE AREA OF PRECIPITATION AND
HAVE UTILIZED THIS BLEND FOR POPS THROUGH THE NIGHT AND INTO
SUNDAY. BEST PRECIPITATION CHANCES WILL REMAIN OVER THE SOUTHEAST
FORECAST AREA. EXPECT PRECIPITATION TO FILL IN OVER THE JAMES
RIVER VALLEY OVER THE NEXT FEW HOURS. PRECIPITATION BAND FROM
SOUTHWEST INTO NORTH CENTRAL NORTH DAKOTA WILL MOVE ACROSS CENTRAL
NORTH DAKOTA AS WELL...WITH BEST PRECIPITATION CHANCES OVER
BISMARCK THROUGH AROUND MIDNIGHT. PRECIPITATION IS EXPECTED TO
MOVE OUT OF THE JAMES RIVER VALLEY AROUND 12-14Z...LOWERED POPS
ACROSS THE AREA EARLY MORNING...THEN BUMPED THEM UP MID TO LATE
MORNING INTO THE AFTERNOON AS WRAP AROUND MOISTURE MOVES INTO THE
AREA ON THE BACK SIDE OF THE EXITING SYSTEM.
UPDATE ISSUED AT |748 PM CDT SAT APR 18 2015
QUICK UPDATE FOR POPS BASED ON LATEST RADAR...ALSO REMOVED
THUNDER OVER THE SOUTHWEST. HEAVIEST SHOWERS LOOK TO REMAIN OVER
THE FAR SOUTH CENTRAL AND INTO EASTERN NORTH DAKOTA THIS EVENING.
BAND MOVING EAST ACROSS THE CENTRAL FROM AROUND MINOT TO GARRISON
TO HEBRON SHOULD HELP MOISTEN THE ATMOSPHERE NEAR KBIS THIS
EVENING. SHOWERS IN THE FAR SOUTH CENTRAL MOVING TOWARD BISMARCK
ARE NOW DISSIPATING ON THE NORTHERN FRINGE. 19 APRIL 00 UTC
SOUNDING STILL SHOWS QUITE A BIT OF DRY AIR BELOW THE MID AND
UPPER LEVEL MOISTURE BEGINNING AROUND 10K FEET.
UPDATE ISSUED AT 638 PM CDT SAT APR 18 2015
UPPER LEVEL LOW OVER SOUTHEAST COLORADO WITH A SHORTWAVE TROUGH
LIFTING NORTH THROUGH WESTERN SOUTH DAKOTA IS PUSHING SHOWERS INTO
CENTRAL NORTH DAKOTA. A NORTHERN STREAM WAVE WITH MORE INSOLATION
TO WORK WITH IS PRODUCING A LINE OF POST FRONTAL SHOWERS AND
ISOLATED THUNDER OVER WESTERN AND NORTH CENTRAL NORTH DAKOTA. THE
THUNDER IS LIMITED TO THE SOUTHWEST...AND WITH THE LOSS OF DAYTIME
HEATING...DO NOT EXPECT THUNDER TO CONTINUE MUCH LONGER. WILL KEEP
A MENTION THROUGH THE EARLY EVENING. EXPECT SHOWERS TO INCREASE
OVER SOUTH CENTRAL INTO EASTERN NORTH DAKOTA LATER THIS EVENING AS
THE SHORTWAVES LIFTING NORTH AND TRACKING EAST CONVERGE OVER
CENTRAL NORTH DAKOTA...AND THEN MOVE INTO BETTER MOISTURE AND
SURFACE SUPPORT AS THE SYSTEM MOVES INTO EASTERN NORTH DAKOTA LATE
TONIGHT. ADJUSTED POPS/SKY COVER BASED MAINLY ON SHORT TERM
CONSENSUS MODEL AND LATEST RADAR. OTHERWISE NO SIGNIFICANT CHANGES
FROM THE GOING FORECAST.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 315 PM CDT SAT APR 18 2015
RAINFALL POTENTIAL THROUGH TONIGHT HIGHLIGHTS THE SHORT TERM
FORECAST.
AS OF 1930 UTC...A COLD FRONT WAS JUST ENTERING NORTHWEST NORTH
DAKOTA AND WILL CONTINUE TO PROPAGATE THROUGH CENTRAL NORTH DAKOTA
THIS EVENING. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WITH
WEAK INSTABILITY HAVE DEVELOPED ALONG THIS FRONT AND WILL APPROACH
THE HIGHWAY 83 CORRIDOR BY 01-02 UTC. AS CYCLOGENESIS OCCURS
ACROSS EASTERN SOUTH DAKOTA THROUGH THE NIGHT AND THE NORTHERN STREAM
WAVE ASSOCIATED WITH THE COLD FRONT PHASES WITH THE LOW TO THE
SOUTH...RAINFALL COVERAGE WILL INCREASE ACROSS CENTRAL NORTH
DAKOTA THROUGH THE EVENING AND NIGHT. THEREAFTER...A WINDY SUNDAY
IS FORECAST IN THE WAKE OF THE NOW DEEPENING LOW ACROSS MINNESOTA.
AT THIS TIME...WIND GUSTS APPEAR TO STAY BELOW ADVISORY CRITERIA
WITH 30 TO 35 KTS TO MIX IN COLD AIR ADVECTION. SCATTERED LIGHT
RAIN SHOWERS ARE ALSO EXPECTED IN WRAP AROUND MOISTURE WITH
PERHAPS A FEW SNOWFLAKES MIXING IN SUNDAY MORNING AS TEMPERATURES
FALL INTO THE MID 30S NORTHWEST AND NORTH CENTRAL. GIVEN GOOD
AGREEMENT...WILL WEIGH HEAVILY ON THE 16-18 UTC HRRR ITERATIONS
BLENDED TO THE GLOBAL 12 UTC DETERMINISTIC AND ENSEMBLE SUITE.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 315 PM CDT SAT APR 18 2015
WINDY WITH SCATTERED SHOWERS TO BEGIN THE EXTENDED...COOL AND DRY
THROUGH THE REMAINDER OF THE WEEK.
AS THE MAIN SURFACE LOW ENTERS NORTHERN MINNESOTA AND SOUTHERN
CANADA...MOISTURE SHOULD WRAP AROUND THE BACKSIDE...PROVIDING
NORTH DAKOTA WITH SOME SCATTERED LIGHT RAIN. THE HIGH RESOLUTION
SHORT TERM MODELS ARE A LITTLE MORE ROBUST WITH PRECIPITATION
COVERAGE THAN THE GLOBAL MODELS (ECMWF/GFS). WITH THE LOW
REMAINING NEARBY AND REMAINING UNDER THE INFLUENCE OF A FAVORABLE
JET STREAK...LIGHT SHOWERS HERE AND THERE AREN`T OUT OF THE
QUESTION THROUGH TUESDAY. GUSTY WINDS ARE EXPECTED THOUGH THE DAY
SUNDAY AND MONDAY AS THE PRESSURE GRADIENT TIGHTENS WITH THE
SURFACE LOW DEEPENING AND PROPAGATING TOWARD THE GREAT LAKES.
THESE GUSTY NORTHWEST WINDS WILL BE ADVECTING DRIER AIR INTO THE
AREA. THIS COULD CREATE RATHER CRITICAL FIRE CONDITIONS MONDAY AS
RELATIVE HUMIDITY DROPS BELOW 20 PERCENT.
THROUGH THE REMAINDER OF THE WORK WEEK...UPPER LOW SLOWLY WORKS
OFF TO THE EAST KEEPING NORTH/NORTHWESTERLY FLOW OVER OUR AREA.
WITH THE EXCEPTION OF ISOLATED SHOWERS EARLY THIS WEEK...DRY
WEATHER IS EXPECTED. TEMPERATURES WILL REMAIN A BIT BELOW
AVERAGE WITH READINGS IN THE 50S FOR HIGHS AND 20S/30S FOR LOWS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1218 AM CDT SUN APR 19 2015
WIDESPREAD RAIN IS EXPECTED TO CONTINUE THROUGH 06Z MONDAY.
KBIS/KJMS HAVE THE GREATEST CHANCES FOR RAIN WITH PERIODS OF MVFR
CONDITIONS POSSIBLE AT EACH OF THE TAF SITES.
&&
.FIRE WEATHER...
ISSUED AT 315 PM CDT SAT APR 18 2015
CRITICAL FIRE WEATHER CONDITIONS MAY BE POSSIBLE ON MONDAY...AND
THIS WILL NEED TO BE MONITORED. WHILE TEMPERATURES WILL ONLY BE IN
THE 50S...MINIMUM RELATIVE HUMIDITY LEVELS OF 15 TO 20 PERCENT AND
NORTHWEST WINDS OF 25 TO 35 MPH ARE POSSIBLE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AC
SHORT TERM...AYD
LONG TERM...AJ
AVIATION...AC
FIRE WEATHER...AYD
AREA FORECAST DISCUSSION
NWS TULSA OK
1101 PM CDT MON APR 20 2015
.DISCUSSION...
THE 06Z TAF DISCUSSION IS INCLUDED BELOW.
&&
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
NO MAJOR CHANGES TO THE 00Z FORECAST. VFR CONDITIONS WILL PREVAIL
WITH INCREASING MID CLOUD CIGS TOWARD 12Z TUES MORNING. INCREASING
WARM ADVECTION ABOVE THE SURFACE WILL YIELD SOME SCT SHRA AND
POSSIBLY A FEW TSRA TUES MORNING.
LACY
&&
.PREV DISCUSSION... /ISSUED 732 PM CDT MON APR 20 2015/
DISCUSSION...
HAVE EXPANDED THE SLIGHT CHANCE POPS FOR TONIGHT AS THE LAST FEW
RUNS OF THE HRRR HAVE BEEN CONSISTENT IN SPREADING THE PRECIP ACROSS
A WIDER SWATH OF EASTERN OKLAHOMA THROUGH 12Z. OTHERWISE...CURRENT
FORECAST FOR TONIGHT IS ON TRACK.
PREV DISCUSSION... /ISSUED 610 PM CDT MON APR 20 2015/
DISCUSSION...
THE 00Z TAF DISCUSSION IS INCLUDED BELOW.
AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
VFR CONDITIONS WILL PREVAIL. INCREASING WARM ADVECTION ABOVE THE
SURFACE WILL PRODUCE MID CLOUD AND CHANCES FOR SHOWERS...POSSIBLY
A FEW STORMS...BY TUESDAY MORNING. CIGS WILL REMAIN IN THE VFR
RANGE HOWEVER.
LACY
PREV DISCUSSION... /ISSUED 351 PM CDT MON APR 20 2015/
DISCUSSION...
CLOUDINESS WILL BE ON THE INCREASE TONIGHT AS A WEAK UPPER LEVEL
IMPULSE APPROACHES THE AREA. SCATTERED SHOWERS AND A FEW
THUNDERSTORMS WILL MOVE INTO THE AREA LATE TONIGHT AND CONTINUE
INTO TUESDAY IN ASSOCIATION WITH THIS SYSTEM.
A FRONTAL BOUNDARY WILL MOVE SOUTH INTO THE AREA LATE TUESDAY
NIGHT AND WEDNESDAY AND WILL STALL NEAR THE RED RIVER. THIS
BOUNDARY WILL THEN RETURN NORTH LATE IN THE WEEK AND WILL BE THE
FOCUS FOR SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS. THERE WILL
BE SOME SEVERE WEATHER THREAT WEDNESDAY AND THURSDAY...ESPECIALLY
IF EARLY DAY CONVECTION IS NOT TOO EXTENSIVE...ALTHOUGH THE
GREATER THREAT MAY BE TO OUR SOUTHWEST WHERE INSTABILITY WILL BE
MAXIMIZED. FRIDAY LOOKS TO BE THE DAY OF GREATEST CONCERN IN OUR
AREA AS LOW PRESSURE ALOFT LIFTS NORTHEAST FROM NEW MEXICO INTO
KANSAS AND A DRYLINE BEGINS TO SURGE EAST ACROSS OKLAHOMA.
A FEW SHOWERS MAY LINGER INTO SATURDAY BUT MOST OF THE WEEKEND
WILL BE DRY BEFORE LOW RAIN CHANCES RETURN BY THE EARLY PART OF
NEXT WEEK.
STAYED CLOSE TO GUIDANCE TEMPERATURES THE NEXT COUPLE DAYS.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 48 73 52 70 / 10 40 20 50
FSM 45 72 52 73 / 10 30 10 50
MLC 47 71 54 74 / 20 30 20 50
BVO 44 74 50 68 / 10 30 20 40
FYV 40 68 47 68 / 0 40 10 40
BYV 43 67 49 66 / 0 30 10 40
MKO 46 72 52 72 / 20 30 10 50
MIO 42 70 49 66 / 0 40 30 30
F10 45 72 54 72 / 20 30 20 50
HHW 46 72 55 75 / 10 20 20 70
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
AVIATION...30
AREA FORECAST DISCUSSION
NWS TULSA OK
732 PM CDT MON APR 20 2015
.DISCUSSION...
HAVE EXPANDED THE SLIGHT CHANCE POPS FOR TONIGHT AS THE LAST FEW
RUNS OF THE HRRR HAVE BEEN CONSISTENT IN SPREADING THE PRECIP ACROSS
A WIDER SWATH OF EASTERN OKLAHOMA THROUGH 12Z. OTHERWISE...CURRENT
FORECAST FOR TONIGHT IS ON TRACK.
&&
.PREV DISCUSSION... /ISSUED 610 PM CDT MON APR 20 2015/
DISCUSSION...
THE 00Z TAF DISCUSSION IS INCLUDED BELOW.
AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
VFR CONDITIONS WILL PREVAIL. INCREASING WARM ADVECTION ABOVE THE
SURFACE WILL PRODUCE MID CLOUD AND CHANCES FOR SHOWERS...POSSIBLY
A FEW STORMS...BY TUESDAY MORNING. CIGS WILL REMAIN IN THE VFR
RANGE HOWEVER.
LACY
PREV DISCUSSION... /ISSUED 351 PM CDT MON APR 20 2015/
DISCUSSION...
CLOUDINESS WILL BE ON THE INCREASE TONIGHT AS A WEAK UPPER LEVEL
IMPULSE APPROACHES THE AREA. SCATTERED SHOWERS AND A FEW
THUNDERSTORMS WILL MOVE INTO THE AREA LATE TONIGHT AND CONTINUE
INTO TUESDAY IN ASSOCIATION WITH THIS SYSTEM.
A FRONTAL BOUNDARY WILL MOVE SOUTH INTO THE AREA LATE TUESDAY
NIGHT AND WEDNESDAY AND WILL STALL NEAR THE RED RIVER. THIS
BOUNDARY WILL THEN RETURN NORTH LATE IN THE WEEK AND WILL BE THE
FOCUS FOR SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS. THERE WILL
BE SOME SEVERE WEATHER THREAT WEDNESDAY AND THURSDAY...ESPECIALLY
IF EARLY DAY CONVECTION IS NOT TOO EXTENSIVE...ALTHOUGH THE
GREATER THREAT MAY BE TO OUR SOUTHWEST WHERE INSTABILITY WILL BE
MAXIMIZED. FRIDAY LOOKS TO BE THE DAY OF GREATEST CONCERN IN OUR
AREA AS LOW PRESSURE ALOFT LIFTS NORTHEAST FROM NEW MEXICO INTO
KANSAS AND A DRYLINE BEGINS TO SURGE EAST ACROSS OKLAHOMA.
A FEW SHOWERS MAY LINGER INTO SATURDAY BUT MOST OF THE WEEKEND
WILL BE DRY BEFORE LOW RAIN CHANCES RETURN BY THE EARLY PART OF
NEXT WEEK.
STAYED CLOSE TO GUIDANCE TEMPERATURES THE NEXT COUPLE DAYS.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
SHORT TERM...10
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1148 PM EDT MON APR 20 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH LATER TONIGHT AND BRING AN END TO
THE STEADY SHOWERS AND THUNDERSTORMS. A LARGE UPPER LEVEL LOW
WILL SET UP OVER ONTARIO AND QUEBEC FOR THE MIDDLE AND LATTER PART
OF THE WEEK...USHERING IN UNSEASONABLY COOL AIR WHICH WILL LAST
INTO THE WEEKEND OR LONGER.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
10 PM UPDATE...HAVE ALLOWED THE TORNADO WATCH TO EXPIRE.
CONVECTION IS STILL ACTIVE OVER THE EASTERN ZONES...BUT TOPS HAVE
COME DOWN WITH THE LOSS OF DAYLIGHT AND THE MAIN THREAT NOW WILL
BE SMALL HAIL AND BRIEF DOWNPOURS.
DID BUMP UP POPS INTO THE WEE HOURS ACCORDING TO THE LATEST RADAR
TRENDS AND HRRR WHICH SHOW MORE SHOWERS GATHERING TO OUR
SOUTHWEST...SLATED TO MOVE THROUGH OVER THE NEXT 3-6 HOURS.
SFC COLD FRONT NOW CROSSING THE PA/OHIO BORDER AND WILL PUSH EAST
ACROSS THE ENTIRE CWA BY 06Z. THE COOLER MOIST UPSLOPE FLOW BEHIND
THE FRONT WILL CREATE PLENTY OF LOW STRATUS ACROSS THE WRN
ALLEGHENIES...WHILE MOST OF THE CENTRAL VALLEY REGION WILL
FLUCTUATE BETWEEN SCT AND BKN CONDITIONS FOR THE REST OF THE
OVERNIGHT.
MIN TEMPS WILL RANGE FROM THE LOWER 40S ACROSS THE LAURELS AND NW
MTNS...TO THE LOWER 50S IN THE SE.
WESTERLY WIND WILL INCREASE AND GUST TO THE MID AND UPPER 20KT
RANGE LATE TONIGHT...SIMILAR TO WHAT WE/RE CURRENTLY SEEING ACROSS
CENTRAL AND ERN OHIO.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
COLD ADVECTION AND WESTERLY UPSLOPE FLOW WILL LEAD TO SCT SHRA
OVER THE NW INTO THE DAY ON TUESDAY...WITH VARIABLE AMOUNTS OF
CLOUDS AND SPRINKLES W/ISOLATED SHRA ALONG AND JUST TO THE SE OF
THE I-99/RT 220 CORRIDOR. MOSTLY SUNNY SKIES EXPECTED FOR THE FAR
SE ZONES.
MAXES TUESDAY WILL BE AROUND 50F IN THE NW AND PERHAPS THE
LAURELS AS WELL. THE LOWER SUSQ WILL PROBABLY REACH THE LOWER 60S.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
THE LONG TERM PATTERN WILL BE DOMINATED BY A LARGE UPPER LEVEL
LOW MOVING THROUGH THE NORTHERN GREAT LAKES...AND THROUGH SOUTHERN
CANADA MIDWEEK TO THE WEEKEND. THERE IS GOOD MODEL CONSENSUS
THROUGH THE MID RANGE PERIOD. AFTER THE FRONT LIFTS OUT BY TUESDAY
MORNING THE UPPER LOW HANGS AROUND S CANADA/NEW ENGLAND FOR
SEVERAL DAYS KEEPING FAIRLY BRISK W/NW FLOW ACROSS PA. THIS WILL
BRING A STEADY STREAM OF COLDER AIR AS TEMPS SLOWLY SLIP A BIT
LOWER EACH DAY WITH BELOW NORMAL READINGS FOR A SEVERAL DAY PERIOD
LINGERING INTO NEXT WEEKEND. PROXIMITY OF UPPER LOW WILL ALSO KEEP
MENTION OF SCT SHOWERS IN THE FORECAST. A SHORTWAVE SHOULD DROP
THROUGH THE REGION WEDNESDAY AFTERNOON INTO THURSDAY MORNING. THIS
COULD DROP EVEN COLDER AIR INTO THE REGION BRINGING THE
POSSIBILITY OF SNOW TO THE NW TO THE CENTRAL REGIONS OF PA. THE
MODELS ARE BECOMING CLOSER TO A CONSENSUS SOLUTION...HOWEVER
SOLUTION IS TRENDING TOWARD THE UPPER LEVEL LOW TO BECOME
QUASI-STATIONARY AND SLOWLY SPINNING OVER QUEBEC.WITH ONLY A
SLIGHT CHANCE FOR PRECIPITATION NEXT WEEKEND. THE MOVEMENT OF THE
LOW WILL DOMINATE THE PATTERN NEXT WEEK WITH IT POSSIBLY
RETROGRADING AND SWINGING ANOTHER TROUGH THROUGH THE REGION NEXT
WEEK.
&&
.AVIATION /04Z TUESDAY THROUGH SATURDAY/...
ASIDE FROM BRIEF IFR VIS IN +TSRA INVOF MDT/LNS THRU 06Z...EXPECT
MVFR/VFR CONDITIONS TO PREVAIL OVERNIGHT AND INTO TUESDAY. SFC
WNDS FROM 250 TO 300 DEGREES WILL BECOME GUSTY AT 25-30KTS BY
TUESDAY MORNING WITH PREDOMINATELY SCT TO BKN MVFR TO VFR CIGS.
OUTLOOK...
WED-SAT...PERSISTENT NW FLOW PATTERN WILL FAVOR MVFR CIGS OVER
THE NW AIRSPACE IN ZOB SECTOR...WITH MAINLY VFR CONDITIONS
PREVAILING IN ZNY DOMAIN. ISOLD TO SCT SHOWERS WILL BE POSSIBLE
ACROSS ALL OF THE AIRSPACE THROUGH THE REMAINDER OF THE WEEK.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/LAMBERT
NEAR TERM...LA CORTE/LAMBERT
SHORT TERM...LAMBERT/CERU
LONG TERM...CERU/RXR
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1006 PM EDT MON APR 20 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH LATER TONIGHT AND BRING AN END TO
THE STEADY SHOWERS AND THUNDERSTORMS. A LARGE UPPER LEVEL LOW
WILL SET UP OVER ONTARIO AND QUEBEC FOR THE MIDDLE AND LATTER PART
OF THE WEEK...USHERING IN UNSEASONABLY COOL AIR WHICH WILL LAST
INTO THE WEEKEND OR LONGER.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
10 PM UPDATE...HAVE ALLOWED THE TORNADO WATCH TO EXPIRE.
CONVECTION IS STILL ACTIVE OVER THE EASTERN ZONES...BUT TOPS HAVE
COME DOWN WITH THE LOSS OF DAYLIGHT AND THE MAIN THREAT NOW WILL
BE SMALL HAIL AND BRIEF DOWNPOURS.
DID BUMP UP POPS INTO THE WEE HOURS ACCORDING TO THE LATEST RADAR
TRENDS AND HRRR WHICH SHOW MORE SHOWERS GATHERING TO OUR
SOUTHWEST...SLATED TO MOVE THROUGH OVER THE NEXT 3-6 HOURS.
SFC COLD FRONT NOW CROSSING THE PA/OHIO BORDER AND WILL PUSH EAST
ACROSS THE ENTIRE CWA BY 06Z. THE COOLER MOIST UPSLOPE FLOW BEHIND
THE FRONT WILL CREATE PLENTY OF LOW STRATUS ACROSS THE WRN
ALLEGHENIES...WHILE MOST OF THE CENTRAL VALLEY REGION WILL
FLUCTUATE BETWEEN SCT AND BKN CONDITIONS FOR THE REST OF THE
OVERNIGHT.
MIN TEMPS WILL RANGE FROM THE LOWER 40S ACROSS THE LAURELS AND NW
MTNS...TO THE LOWER 50S IN THE SE.
WESTERLY WIND WILL INCREASE AND GUST TO THE MID AND UPPER 20KT
RANGE LATE TONIGHT...SIMILAR TO WHAT WE/RE CURRENTLY SEEING ACROSS
CENTRAL AND ERN OHIO.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
COLD ADVECTION AND WESTERLY UPSLOPE FLOW WILL LEAD TO SCT SHRA
OVER THE NW INTO THE DAY ON TUESDAY...WITH VARIABLE AMOUNTS OF
CLOUDS AND SPRINKLES W/ISOLATED SHRA ALONG AND JUST TO THE SE OF
THE I-99/RT 220 CORRIDOR. MOSTLY SUNNY SKIES EXPECTED FOR THE FAR
SE ZONES.
MAXES TUESDAY WILL BE AROUND 50F IN THE NW AND PERHAPS THE
LAURELS AS WELL. THE LOWER SUSQ WILL PROBABLY REACH THE LOWER 60S.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
THE LONG TERM PATTERN WILL BE DOMINATED BY A LARGE UPPER LEVEL
LOW MOVING THROUGH THE NORTHERN GREAT LAKES...AND THROUGH SOUTHERN
CANADA MIDWEEK TO THE WEEKEND. THERE IS GOOD MODEL CONSENSUS
THROUGH THE MID RANGE PERIOD. AFTER THE FRONT LIFTS OUT BY TUESDAY
MORNING THE UPPER LOW HANGS AROUND S CANADA/NEW ENGLAND FOR
SEVERAL DAYS KEEPING FAIRLY BRISK W/NW FLOW ACROSS PA. THIS WILL
BRING A STEADY STREAM OF COLDER AIR AS TEMPS SLOWLY SLIP A BIT
LOWER EACH DAY WITH BELOW NORMAL READINGS FOR A SEVERAL DAY PERIOD
LINGERING INTO NEXT WEEKEND. PROXIMITY OF UPPER LOW WILL ALSO KEEP
MENTION OF SCT SHOWERS IN THE FORECAST. A SHORTWAVE SHOULD DROP
THROUGH THE REGION WEDNESDAY AFTERNOON INTO THURSDAY MORNING. THIS
COULD DROP EVEN COLDER AIR INTO THE REGION BRINGING THE
POSSIBILITY OF SNOW TO THE NW TO THE CENTRAL REGIONS OF PA. THE
MODELS ARE BECOMING CLOSER TO A CONSENSUS SOLUTION...HOWEVER
SOLUTION IS TRENDING TOWARD THE UPPER LEVEL LOW TO BECOME
QUASI-STATIONARY AND SLOWLY SPINNING OVER QUEBEC.WITH ONLY A
SLIGHT CHANCE FOR PRECIPITATION NEXT WEEKEND. THE MOVEMENT OF THE
LOW WILL DOMINATE THE PATTERN NEXT WEEK WITH IT POSSIBLY
RETROGRADING AND SWINGING ANOTHER TROUGH THROUGH THE REGION NEXT
WEEK.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
A STRONG SFC COLD FRONT PUSHES EAST ACROSS ALL AIRFIELDS BETWEEN
02Z-07Z TUESDAY.
COLDER AND MOIST WESTERLY UPSLOPE FLOW IN THE WAKE OF THE FRONT
WILL QUICKLY LOWER CIGS AT KJST AND KBFD BACK DOWN INTO THE IFR OR
LIFR RANGE TONIGHT AND EARLY TUESDAY WITH AREAS OF MVFR LINGERING
DURING THE DAY TUESDAY.
FOR THE SUSQ VALLEY AIRFIELDS...VSBYS WILL BE VFR TO BRIEF MVFR
IN SHRA/TSRA TONIGHT...WHILE CIGS IN THE MVFR RANGE SHOULD BE
FAIRLY WIDESPREAD ACROSS THE CENTRAL MTNS AS THE MUCH COOLER AIR
PUSHES IN. BKN CIGS IMPROVE TO MAINLY VFR BY LATE MORNING TUESDAY
ACROSS THIS SAME REGION.
OUTLOOK...
TUE-FRI...PERSISTENT NW FLOW PATTERN EACH DAY WILL FAVOR MVFR CIGS
OVER THE NW AIRSPACE IN ZOB SECTOR...WITH MAINLY VFR CONDITIONS
PREVAILING IN ZNY DOMAIN. SCT SHOWERS WILL BE POSSIBLE ACROSS ALL
OF THE AIRSPACE THROUGH THE REMAINDER OF THE WEEK.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/LAMBERT
NEAR TERM...LA CORTE/LAMBERT
SHORT TERM...LAMBERT/CERU
LONG TERM...CERU/RXR
AVIATION...LAMBERT
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1221 PM EDT SUN APR 19 2015
.SYNOPSIS...
A WARM FRONT AND UPPER LEVEL DISTURBANCE APPROACHING FROM THE
TENNESSEE VALLEY WILL BRING A SOAKING RAIN TO THE REGION TONIGHT
AND EARLY MONDAY. ADDITIONAL SHOWERS AND SCATTERED THUNDERSTORMS
WILL ACCOMPANY A COLD FRONT AS IT PUSHES EAST ACROSS THE STATE
MONDAY AFTERNOON AND EVENING. A LARGE UPPER LEVEL LOW WILL SET UP
OVER ONTARIO AND QUEBEC FOR THE MIDDLE AND LATTER PART OF THE
WEEK...USHERING IN UNSEASONABLY COOL AIR WHICH WILL LAST INTO THE
WEEKEND OR LONGER.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
EARLIER...THICKER CIRROSTRATUS HAS THINNED ACROSS MUCH OF CENTRAL
AND NEPA...BUT THIS WINDOW WILL BE FLEETING AS THICKENING MID AND
HIGH CLOUDS STREAM IN QUICKLY FROM THE SW DURING THE MID TO LATE
AFTERNOON HOURS...WITH THE ONSET OF RAIN 4-6 HOURS AFTERWARD.
THE DECENT AMOUNT OF SUNSHINE HAS HELPED TO BOOST TEMPS A FEW-SVRL
DEG F ABOVE FCST HOURLY VALUES DURING THE LATE MORNING...BUT NOT
MUCH ABOVE ACTUAL FCST HIGHS FOR TODAY. SOME MAX TEMP TWEAKS WERE
DONE TO THE GRIDDED FCST DATABASE.
OVERALL...A RATHER NICE EARLY SPRING AFTERNOON...WITH A LIGHT TO
MODERATE SERLY BREEZE AND HIGH TEMPS RANGING FROM AROUND 60F
ACROSS THE HIGHER TERRAIN OF THE NORTH AND WEST...TO THE UPPER 60S
THROUGHOUT MUCH OF THE SUSQ VALLEY.
LATEST MODEL TIMING OF THE LEADING...NE EDGE OF RAIN /INCLUDING
THE 12Z NAM...09Z SREF...AND LATEST 14Z HRRR RUN/ SUGGESTS THE
BULK OF THE REGION WILL BE DRY FOR MUCH OF THE DAY.
FAR SOUTHWESTERN AREAS WILL LIKELY SEE SHOWERS BEGIN AROUND 5 PM
/21Z/...WHILE THE ONSET OF RAIN/SHOWERS MOVES TO NEAR A KBFD...TO
KUNV AND KMRB LINE AROUND 01Z MONDAY...THEN ACROSS THE SUSQ VALLEY
BETWEEN 03Z-05Z MONDAY.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH MONDAY NIGHT/...
LITTLE TO NO CHANGE WAS NECESSARY FROM THE PREVIOUS FEW FORECAST
CYCLES FOR THIS SHORT TERM PERIOD. THE MAIN CHANGE WAS TO FURTHER
REFINE THE TIMING AND TO SHOW A SLIGHTLY MORE-OBVIOUS 4-6HR BREAK
BETWEEN THE OVERNIGHT/MORNING RAIN AND THE STORMS IN THE
AFTERNOON/EVENING. MINS WILL BE HELD UP AS THE WINDS WILL BE
BREEZY. USUALLY...CENTRAL PA DOES NOT GET STRONG WIND GUSTS DURING
STABLE SERLY FLOW RAIN EVENTS. SO THOUGHTS OF A WIND ADVY WERE
DISCOUNTED RATHER EARLY IN THE FORECAST PROCESS TONIGHT.
HOWEVER...THE STRONG LOW AND MID LEVEL FLOW WILL BUMP THE PWATS
INTO THE 1-1.5 INCH RANGE TONIGHT AND MONDAY. THUS...RAIN COULD BE
HEAVY AT TIMES. WITH THE ADDITIONAL TSRA MON PM...THE
QPF REACHES BETWEEN 0.75 AND 1.25 INCHES OVER A LARGE PORTION OF
THE AREA. BUT THE STREAM FLOWS ARE REALLY LOW AND NO THUNDER
TONIGHT SHOULD TRANSLATE INTO NO FLOOD WORRIES OTHER THAN SOME
PONDING OF WATER ON ROADS AND A FEW SMALL CREEKS AT BANKFULL.
THINGS ARE GROWING NICELY NOW IN THE SE AND EVEN LOCALLY IN HAPPY
VALLEY WHICH SHOULD TAKE UP PLENTY OF WATER COMPARED TO JUST TWO
WEEKS AGO. SPC HAS PLACED ALL OF THE AREA INTO MRGL RISK AND
BROUGHT THE DAY2 SLGT RISK INTO SRN PA...RIGHTFULLY SO. THE BREAK
AND ASSOCIATED BREAKS IN THE CLOUDS/WARM SECTOR ON MONDAY WILL
LEAD TO GOOD HEATING AND THE FRONT/FORCING COMES THROUGH AT AN
OPPORTUNE TIME TO GRAB THE MAX CAPES AND MIN STABILITY. CAPES MAY
BE AROUND 1500J/KG AND LI/S DROP TO -3 TO -5. WIND PROFILES ARE
MAINLY MULTI-CELLULAR - BUT WITH THE WARM FRONT LIKELY CUTTING
THROUGH THE AREA AT THE TIME...WILL NEED TO KEEP AN EYE OUT FOR
ROTATING STORMS - ESPECIALLY IF THEY OCCUR ON OR NEAR LLVL
BOUNDARIES.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
BEHIND THE COLD FRONT MIDWEEK...THE UPPER LOW HANGS AROUND S
CANADA/NEW ENGLAND FOR SEVERAL DAYS KEEPING FAIRLY BRISK W/NW FLOW
ACROSS PA. THIS WILL BRING A STEADY STREAM OF COLDER AIR AS TEMPS
SLOWLY SLIP A BIT LOWER EACH DAY WITH BELOW NORMAL READINGS FOR A
SEVERAL DAY PERIOD LINGERING INTO NEXT WEEKEND. PROXIMITY OF
UPPER LOW WILL ALSO KEEP MENTION OF SCT SHOWERS IN THE FORECAST...
MAINLY DURING THE DAYTIME HOURS. WEDNESDAY MAY HOLD A FAST-MOVING
SHORT-WAVE WHICH COULD PRODUCE WHITE PRECIP - BUT DURING THE
MIDDLE OF THE DAY.
&&
.AVIATION /16Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS WILL PREVAIL MUCH OF THE DAY...BUT RAPIDLY
DETERIORATE FROM SOUTHWEST TO NORTHEAST TONIGHT. EXPECT
RESTRICTIONS TO REACH THE FIRST CENTRAL PENNSYLVANIA AIRFIELDS
AROUND 00Z MONDAY /KJST/.
TIGHTENING GRADIENT LATER TODAY AND TONIGHT AHEAD OF AN
APPROACHING COLD FRONT WILL PRODUCE GUSTY WINDS...AND LOW LEVEL
WIND SHEAR CONDITIONS. THESE HAVE NOW BEEN ADDED TO ALL TAFS
STARTING BETWEEN 00 AND 04Z.
RAIN AND WIDESPREAD IFR TO LIFR TONIGHT INTO MONDAY...BEFORE THE
PRECIPITATION BECOMES MORE SHOWERY WITH THE APPROACH OF THE FRONT.
THIS COLD FRONT WILL ALSO INTRODUCE THE CHANCE OF THUNDERSTORMS
MONDAY TO THE ENTIRE REGION.
OUTLOOK...
MON...WIDESPREAD RESTRICTIONS IN RAIN EARLY...SOME IMPROVEMENT IN
THE AFTERNOON...BUT TSRA POSSIBLE.
TUE- THU...UNSETTLED WITH NW FLOW EACH DAY...WITH AREAS OF
RESTRICTED CIGS/VSBYS IN SHRA IN THE WESTERN AND NORTHERN
MOUNTAINS...SPOTTY RESTRICTIONS IN MORE SCATTERED SHRA IN CENTRAL
MOUNTAINS...AND MAINLY VFR IN THE EAST AND SOUTHEAST.
&&
.FIRE WEATHER...
SFC WIND FROM THE SOUTHEAST WILL BE 10-15 KTS WITH GUSTS AROUND
20KT ACROSS THE HIGHER TERRAIN OF SOUTHERN AND WESTERN PENN THIS
AFTERNOON...WHILE THE WIND STAYS A BIT LIGHTER ACROSS THE NE HALF
OF THE STATE - WHERE REL HUMIDITY IS EXPECTED TO DIP TO/STAY BELOW
30 PERCENT FOR THE REST OF THE AFTERNOON.
GUSTS OF 15 TO 20 MPH ARE POSSIBLE IN THE NORTHEAST BY LATE
AFTERNOON.
BUT THE GUSTS OVER 20MPH WILL ONLY MATCH UP WITH THE LOW RH/S FOR
AN HOUR OR TWO AT THE MOST AND ONLY IN A SMALL PORTION OF THE
NORTHERN MOUNTAINS. THEREFORE...PLAN IS AT THIS POINT - NOT TO
ISSUE A RED FLAG WARNING.
A SIGNIFICANT RAINFALL IS EXPECTED STARTING THIS EVENING AND
LASTING UNTIL A COLD FRONT PUSHES THROUGH ON MONDAY AFTERNOON AND
EVENING. COOLER TEMPERATURES FOR THE REST OF THE WEEK WILL LIKELY
LEAD TO HIGHER RH/S AND KEEP FIRE WEATHER CONDITIONS BELOW
CRITICAL.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...DANGELO/LAMBERT
LONG TERM...CERU/RXR
AVIATION...JUNG
FIRE WEATHER...LAMBERT
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
200 PM CDT SUN APR 19 2015
.DISCUSSION...SURFACE MAP AT 18Z SHOWS A 1000 MB LOW CENTERED OVER
SOUTHERN ILLINOIS, WITH A WARM FROM SITUATED TO OUR NORTH, A
COLD FRONT STILL WEST OF THE MISSISSIPPI RIVER, AND A PRE-FRONTAL
TROUGH JUST NOW CROSSING THE TENNESSEE RIVER THAT IS PROVIDING THE
FOCUS FOR A DEVELOPING LINE OF CONVECTION. SATELLITE IMAGERY IS
STARTING TO SHOW SOME BREAKS IN THE CLOUDS, ESPECIALLY WEST OF
NASHVILLE. LAPS SOUNDING FOR BNA AT 18Z SHOWS WEAK INSTABILITY,
WITH A LIFTED INDEX OF -3.3 AND A CAPE OF 962 J/KG. ATMOSPHERE
REMAINS SUFFICIENTLY MOIST, WITH PRECIPITABLE WATER OF 1.44 INCHES
AND A K-INDEX OF 34. LATEST HRRR SHOWS SCATTERED CELLS ACROSS
MIDDLE TENNESSEE UNTIL A MORE ORGANIZED LINE OF CONVECTION COMES
THROUGH WITH THE COLD FRONT BETWEEN 04Z AND 09Z. GIVEN THE TIMING
OF THE FRONT, THE POTENTIAL FOR WIDESPREAD SEVERE STORMS APPEARS
LOW, ALTHOUGH MIDDLE TENNESSEE DOES REMAIN UNDER A SLIGHT RISK OF
SEVERE WEATHER TODAY AND TONIGHT, SO ISOLATED CASES OF SEVERE
ACTIVITY ARE STILL POSSIBLE. AFTER A FEW LINGERING SHOWERS ON
MONDAY, LOOK FOR A BRIEF RESPITE ON TUESDAY BEFORE THE NEXT COLD
FRONT DROPS SOUTHWARD THROUGH MIDDLE TENNESSEE WEDNESDAY AND
THURSDAY. GIVEN THAT THE UPPER FLOW ACROSS THE REGION WILL REMAIN
EITHER CYCLONIC OR ZONAL, WARM ADVECTION WILL BE HARD TO COME BY,
AND SO TEMPERATURES DURING THE NEXT 7 DAYS WILL REMAIN AT OR BELOW
NORMAL.
&&
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 60 67 43 72 / 50 40 10 10
CLARKSVILLE 57 66 41 71 / 50 40 05 10
CROSSVILLE 58 62 42 63 / 50 60 20 10
COLUMBIA 59 68 43 73 / 60 30 10 10
LAWRENCEBURG 57 67 43 72 / 60 20 10 10
WAVERLY 57 68 42 72 / 60 30 05 10
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
ROSE
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1135 PM CDT SAT APR 18 2015
.UPDATE...FOR AVIATION.
&&
.AVIATION...
06Z TAFS...BNA/CKV/CSV...A LOW PRESSURE SYSTEM AND WARM FRONT
WILL LIFT INTO MID TN OVERNIGHT BRINGING WIDESPREAD SHOWERS.
LOOK FOR -SHRA WITH MVFR CIGS/VSBYS TO DEVELOP AROUND 08Z...WITH
TEMPO IFR AND SOME LIFR 10Z-15Z. THE MAIN BAND OF MOISTURE WILL
LIFT NORTH OF MID TN BY 18Z. ANOTHER SYSTEM WILL APPROACH SUNDAY
AFTERNOON AND EVENING WITH SCATTERED TSRA...SOME POSSIBLY SEVERE.
13
&&
.PREV DISCUSSION... /ISSUED 1006 PM CDT SAT APR 18 2015/
UPDATE...
HAVE UPDATED THE SUITE OF FORECAST PRODUCTS TO INCREASE SHWR/TSTM CHANCES
FROM SW TO NE REST OF EVENING AND OVERNIGHT. TWEAKED HRLY TEMP...DEWPOINT...
SKY...AND WIND SPEED/DIRECTION GRIDS ALSO. REMAINDER OF FORECAST
REMAINS ON TRACK.
PREV DISCUSSION... /ISSUED 530 PM CDT SAT APR 18 2015/
UPDATE...
HAVE UPDATED THE SUITE OF FORECAST PRODUCTS TO REFLECT CURRENT REGIONAL
SFC OBS...SATELLITE...AND MOSAIC RADAR TRENDS ALONG WITH THE LATEST IN
SHORT RANGE MODEL CONSENSUS...THUS MAINTAINING ISO SHWRS/TSTMS THRU AT
LEAST THE MID EVENING HRS. BULK OF SHWR/TSTMS ACTIVITY SHOULD SPREAD FROM
THE SW TO THE NE ACROSS THE MID STATE AFTER MIDNIGHT.
PREV DISCUSSION.../ISSUED 351 PM CDT SAT APR 18 2015/
DISCUSSION...
AS AN UPPER TROUGH CENTERED OVER THE CENTRAL PLAINS MOVES EAST THIS
AFTERNOON AND OVERNIGHT IT WILL INFLUENCE SHOWERS AND THUNDERSTORMS
TO CONTINUE THEIR TREK NORTHWARD THROUGH MIDDLE TN. HRRR IS FORECASTING
SCATTERED AFTERNOON ACTIVITY TO MOVE INTO KENTUCKY AND ANOTHER
WAVE OF PRECIP TO SPREAD INTO MIDDLE TENNESSEE FROM THE SOUTH
BEFORE MIDNIGHT. PWAT VALUES WILL BE AROUND 1.5 INCHES FOR SEVERAL
HOURS OVERNIGHT TONIGHT. WITH THE GROUND ALREADY SATURATED FROM
THIS PAST WEEK`S RAINFALL...WE COULD SEE CREEKS AND STREAMS RISE
PRETTY QUICKLY DURING THE OVERNIGHT HOURS...WATCH FOR MINOR
FLOODING IN LOW LYING AREAS AND PONDING OF WATER ON ROADWAYS
OVERNIGHT. WHILE THERE MAY BE STORMS AROUND...NOT EXPECTING
ANYTHING STRONG OR SEVERE TONIGHT.
BETWEEN LATE SUNDAY MORNING AND EARLY AFTERNOON THE DEEPEST
MOISTURE WILL PUSH NORTH OF OUR AREA. LINGERING CLOUD
COVER...ESPECIALLY OVER THE NORTHEASTERN PORTION OF THE CWA MAY
INHIBIT INSTABILITY...BUT CLOUDS SHOULD BREAK UP ENOUGH DURING
THE AFTERNOON HOURS TO ALLOW FOR TEMPERATURES TO WARM INTO THE LOW
70S ALONG THE CUMBERLAND PLATEAU AND MID 70S ELSEWHERE. THIS
SHOULD BE WARM ENOUGH TO INITIATE ISOLATED TO SCATTERED STORMS
THROUGHOUT THE AFTERNOON. CURRENTLY SPC HAS THE MID-STATE IN A
SLIGHT RISK FOR SEVERE THUNDERSTORMS FOR SUNDAY AFTERNOON THROUGH
SUNDAY NIGHT. THE MAIN THREAT WITH ANY STORMS DURING THIS TIME
FRAME WILL BE DAMAGING WINDS AND HAIL. WE COULD SEE A COUPLE OF
ROUNDS OF THUNDERSTORMS OVERNIGHT SUNDAY NIGHT AHEAD OF A
SHORTWAVE AND ITS ASSOCIATED SURFACE LOW...WHICH STRENGTHEN OVER
SOUTHERN ILLINOIS AND HEAD NORTHEAST ON MONDAY.
THE FRONTAL PASSAGE ASSOCIATED WITH THE AFOREMENTIONED LOW WILL
OCCUR ON MONDAY AND WILL ALLOW FOR TEMPERATURES TO COOL INTO THE
40S OVERNIGHT MONDAY NIGHT. ALL PRECIP SHOULD PUSH EAST OF THE
TENNESSEE VALLEY TUESDAY NIGHT. A SURFACE HIGH MOVES IN ON TUESDAY
AND GIVES US A MUCH NEEDED DRY AND RELATIVELY COOL DAY WITH HIGH
TEMPERATURES IN THE MID 60S.
THE NEXT CHANCE OF PRECIP ENTERS THE FORECAST WEDNESDAY EVENING AS
A WEAK FRONT BRINGS A CHANCE OF SHOWERS AND THUNDERSTORMS THROUGH
THE AREA. COULD SEE A BREAK ON FRIDAY AS THAT MOISTURE PUSHES
SOUTH...THEN ANOTHER SURFACE LOW BRINGS ADDITIONAL THUNDERSTORM
CHANCES FRIDAY NIGHT.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
1059 PM CDT MON APR 20 2015
.AVIATION...
SHOWERS AND POSSIBLY A THUNDERSTORM COULD IMPACT KAMA UNTIL AROUND
07Z. OTHERWISE...VFR CEILINGS EXPECTED OVERNIGHT. LIGHT SURFACE
WINDS EXPECTED TUESDAY MORNING. SOUTHERLY SURFACE WINDS EXPECTED
TUESDAY AFTERNOON WITH HIGH-BASED CUMULUS. SHOWERS AND THUNDERSTORMS
EXPECTED TO NOT MAKE MUCH OF AN IMPACT ON TERMINALS THROUGH 06Z
WEDNESDAY...WITH BETTER PROSPECTS FOR CONVECTION JUST BEYOND THE
DURATION OF THIS FORECAST.
COCKRELL
&&
.PREV DISCUSSION... /ISSUED 643 PM CDT MON APR 20 2015/
UPDATE...
UPDATED GRAPHICAL FORECASTS TO INCLUDE ISOLATED THUNDER THIS EVENING.
LIGHTNING STRIKES CURRENTLY BEING OBSERVED IN NORTHWEST PART OF
FORECAST AREA AND IN EASTERN NEW MEXICO. WITH STRENGTH OF SHORTWAVE
TROF MOVING IN FROM THE WEST AT THIS TIME...BELIEVE THAT ADDITIONAL
THUNDER CAN BE EXPECTED. UPDATED TEXT PRODUCTS HAVE BEEN ISSUED.
COCKRELL
AVIATION...
SHORTWAVE TROF WILL CAUSE SHOWERS AND ISOLATED THUNDERSTORMS TO
DEVELOP THIS EVENING AND OVERNIGHT. EXPECTING VFR OVERCAST AND
MAINLY SHOWERS TO IMPACT ALL TERMINALS. PRECIPITATION EXPECTED TO
END BY 09Z TUESDAY WITH CONTINUED VFR CONDTIONS THEREAFTER.
COCKRELL
PREV DISCUSSION... /ISSUED 250 PM CDT MON APR 20 2015/
SHORT TERM... (TONIGHT)
THE SURFACE HIGH WILL CONTINUE TO SLIDE EAST ALLOWING FOR SOUTHERLY
FLOW TO BRING GULF MOISTURE INTO THE AREA AND BRINGING UPSLOPING
WINDS. THE UPPER LEVEL RIDGE OFF TO THE WEST IS ALSO MOVING
EASTWARD AND BRINGING A VORT LOBE THROUGH THE AREA. THESE TWO
LIFTING MECHANISMS WILL CREATE CHANCES FOR RAIN SHOWERS OVER THE
CENTRAL TO SOUTHERN TX PANHANDLE BETWEEN 6PM THROUGH 1AM. PREFERRED
THE GFS MODEL OVER NAM AS IT CAPTURED QPF LOCATIONS BETTER AS IT
AGREED WITH TEXAS TECH WRF AND HRRR MODELS. THUS WENT WITH MAV
GUIDANCE ON WINDS AND DEW POINTS. TONIGHT SHOULD BE WARMER THAN
LAST NIGHT DUE TO INCREASED CLOUD COVER AND THE SOUTHERLY FLOW
CREATING LOWS IN THE UPPER 30S TO MID 40S OVERNIGHT.
MB/CLK
LONG TERM... (TOMORROW THROUGH SUNDAY)
THERE IS A VERY LOW PROBABILITY OF RESIDUAL CONVECTION IN THE FAR
EAST TOMORROW MORNING AS SUBTLE MID-LEVEL WAVE EXITS THE AREA. LATER
IN THE DAY WEAK HEIGHT FALLS OCCUR JUST TO OUR WEST AS CLOSED LOW IN
THE SOUTHWEST CONUS DEEPENS. ALTHOUGH SUBTLE (AND DESPITE STILL
RELATIVELY WEAK MEAN WESTERLY-NORTHWESTERLY FLOW) THIS SHOULD STILL
BE SUFFICIENT TO FORCE LEE SURFACE PRESSURE FALLS AND START THE
NORTHWESTWARD MOVEMENT OF LOW LEVEL MOISTURE BACK INTO THE AREA.
CURRENT SURFACE OBSERVATION SHOW OFF SHORE FLOW WITH RICH LOW LEVEL
MOISTURE LIMITED TO COASTAL AREAS AND DEEP SOUTH TEXAS. SHORT RANGE
GUIDANCE GENERALLY SHOWS THE EQUATORWARD PUSH OF THE COLD FRONT HAS
STOPPED AS SURFACE FLOW VEERING IN RESPONSE TO
STRENGTHENING/SOUTHEASTWARD MOVING SURFACE HIGH IN THE LOWER
MISSISSIPPI VALLEY. TIMING OF RELATIVELY RICH LOW-LEVEL MOISTURE IS
SOMEWHAT IN QUESTION GIVEN EVAPOTRANSPIRATIVE PARAMETRIZATION
POSSIBLY EXAGGERATING QUALITY OF MOISTURE RETURN INITIALLY. AM
CONCERNED THAT GOOD QUALITY MOISTURE RETURN MAY BE TOO RAPID THROUGH
LATE AFTERNOON/EARLY EVENING. SOME CONVECTION COULD FORM BY LATE
AFTERNOON BUT COVERAGE OF MEASURABLE PRECIPITATION SHOULD BE LIMITED
NECESSITATING ONLY SLIGHT CHANCE PROBABILITIES THROUGH EARLY EVENING.
0-2KM THETA-E VALUES TREND UPWARD NOTABLY AFTER DARK AND WITH
INCREASING LARGE SCALE FORCING PRECIPITATION PROBABILITIES SHOULD BE
MARKEDLY HIGHER DURING THE EVENING AND OVERNIGHT PERIOD...ESPECIALLY
ACROSS THE EASTERN PORTION OF THE FORECAST AREA. A COLD FRONT FORCED
BY A NORTHERN STREAM WAVE WILL REACH OUR AREA BY WEDNESDAY MORNING
WITH UNCERTAINTY INCREASING SOMEWHAT BY THIS TIME. THE BOUNDARY WILL
PROBABLY PROGRESS SLOWLY SOUTHWARD THROUGH THE AREA BY EVENING WITH
WEAK ISENTROPIC LIFT ATOP SHALLOW COOL LAYER RESULTING IN
CONVECTION. HAVE DIMINISHED PROBABILITIES OVERNIGHT AS MOIST UPGLIDE
OVER THE BOUNDARY WEAKENS AND MID LEVEL HEIGHTS RISE SOME.
CONFIDENCE IS A LITTLE HIGHER IN THE EXTENDED GIVEN BETTER AGREEMENT
OF MEDIUM RANGE DETERMINISTIC GUIDANCE AND LESS SPREAD IN THE
ENSEMBLE MEMBERS. BY THURSDAY A MUCH MORE SIGNIFICANT MID-UPPER
TROUGH IN THE SOUTHWEST APPROACHES CAUSING A FAIRLY DRAMATIC SURFACE
RESPONSE THROUGH FRIDAY. STRENGTHENING LEE TROUGH/LOW WILL RESULT IN
INCREASED LOW-LEVEL MOIST FLOW AGAIN AND WITH MIXING BY THURSDAY
AFTERNOON THE DRYLINE WILL SHARPEN ACROSS THE AREA. THE BEST
OPPORTUNITY FOR PRECIPITATION WITH THIS SYSTEM WILL BE THURSDAY
AFTERNOON AND EVENING AHEAD OF SHARPENING DRYLINE WHICH SEEMS MOST
LIKELY TO BE POSITIONED NORTH-SOUTH ACROSS THE CENTRAL PORTION OF
THE PANHANDLES.
GIVEN THE PROGRESSIVE NATURE OF THIS SYSTEM A PERIOD OF POST-DRYLINE
DEEP MIXING MAY OCCUR FRIDAY AFTERNOON WITH CONCERNS FOR FIRE WEATHER
POSSIBLY DEVELOPING THEN. BY THE WEEKEND IN THE WAKE OF THIS WAVE A
QUASI-ZONAL UPPER FLOW PATTERN EVOLVES WITH SOME FAIRLY SIZABLE
PERTURBATIONS SHOWING UP IN MEDIUM RANGE GUIDANCE...PARTICULARLY
AROUND SUNDAY. ALTHOUGH TIMING IS UNCERTAIN AT THIS POINT IN
TIME...DID MAINTAIN LOW PRECIPITATION PROBABILITIES ON SUNDAY.
BRB
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
03/15
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
643 PM CDT MON APR 20 2015
.UPDATE...
UPDATED GRAPHICAL FORECASTS TO INCLUDE ISOLATED THUNDER THIS EVENING.
LIGHTNING STRIKES CURRENTLY BEING OBSERVED IN NORTHWEST PART OF
FORECAST AREA AND IN EASTERN NEW MEXICO. WITH STRENGTH OF SHORTWAVE
TROF MOVING IN FROM THE WEST AT THIS TIME...BELIEVE THAT ADDITIONAL
THUNDER CAN BE EXPECTED. UPDATED TEXT PRODUCTS HAVE BEEN ISSUED.
COCKRELL
&&
.AVIATION...
SHORTWAVE TROF WILL CAUSE SHOWERS AND ISOLATED THUNDERSTORMS TO
DEVELOP THIS EVENING AND OVERNIGHT. EXPECTING VFR OVERCAST AND
MAINLY SHOWERS TO IMPACT ALL TERMINALS. PRECIPITATION EXPECTED TO
END BY 09Z TUESDAY WITH CONTINUED VFR CONDTIONS THEREAFTER.
COCKRELL
&&
.PREV DISCUSSION... /ISSUED 250 PM CDT MON APR 20 2015/
SHORT TERM... (TONIGHT)
THE SURFACE HIGH WILL CONTINUE TO SLIDE EAST ALLOWING FOR SOUTHERLY
FLOW TO BRING GULF MOISTURE INTO THE AREA AND BRINGING UPSLOPING
WINDS. THE UPPER LEVEL RIDGE OFF TO THE WEST IS ALSO MOVING
EASTWARD AND BRINGING A VORT LOBE THROUGH THE AREA. THESE TWO
LIFTING MECHANISMS WILL CREATE CHANCES FOR RAIN SHOWERS OVER THE
CENTRAL TO SOUTHERN TX PANHANDLE BETWEEN 6PM THROUGH 1AM. PREFERRED
THE GFS MODEL OVER NAM AS IT CAPTURED QPF LOCATIONS BETTER AS IT
AGREED WITH TEXAS TECH WRF AND HRRR MODELS. THUS WENT WITH MAV
GUIDANCE ON WINDS AND DEW POINTS. TONIGHT SHOULD BE WARMER THAN
LAST NIGHT DUE TO INCREASED CLOUD COVER AND THE SOUTHERLY FLOW
CREATING LOWS IN THE UPPER 30S TO MID 40S OVERNIGHT.
MB/CLK
LONG TERM... (TOMORROW THROUGH SUNDAY)
THERE IS A VERY LOW PROBABILITY OF RESIDUAL CONVECTION IN THE FAR
EAST TOMORROW MORNING AS SUBTLE MID-LEVEL WAVE EXITS THE AREA. LATER
IN THE DAY WEAK HEIGHT FALLS OCCUR JUST TO OUR WEST AS CLOSED LOW IN
THE SOUTHWEST CONUS DEEPENS. ALTHOUGH SUBTLE (AND DESPITE STILL
RELATIVELY WEAK MEAN WESTERLY-NORTHWESTERLY FLOW) THIS SHOULD STILL
BE SUFFICIENT TO FORCE LEE SURFACE PRESSURE FALLS AND START THE
NORTHWESTWARD MOVEMENT OF LOW LEVEL MOISTURE BACK INTO THE AREA.
CURRENT SURFACE OBSERVATION SHOW OFF SHORE FLOW WITH RICH LOW LEVEL
MOISTURE LIMITED TO COASTAL AREAS AND DEEP SOUTH TEXAS. SHORT RANGE
GUIDANCE GENERALLY SHOWS THE EQUATORWARD PUSH OF THE COLD FRONT HAS
STOPPED AS SURFACE FLOW VEERING IN RESPONSE TO
STRENGTHENING/SOUTHEASTWARD MOVING SURFACE HIGH IN THE LOWER
MISSISSIPPI VALLEY. TIMING OF RELATIVELY RICH LOW-LEVEL MOISTURE IS
SOMEWHAT IN QUESTION GIVEN EVAPOTRANSPIRATIVE PARAMETRIZATION
POSSIBLY EXAGGERATING QUALITY OF MOISTURE RETURN INITIALLY. AM
CONCERNED THAT GOOD QUALITY MOISTURE RETURN MAY BE TOO RAPID THROUGH
LATE AFTERNOON/EARLY EVENING. SOME CONVECTION COULD FORM BY LATE
AFTERNOON BUT COVERAGE OF MEASURABLE PRECIPITATION SHOULD BE LIMITED
NECESSITATING ONLY SLIGHT CHANCE PROBABILITIES THROUGH EARLY EVENING.
0-2KM THETA-E VALUES TREND UPWARD NOTABLY AFTER DARK AND WITH
INCREASING LARGE SCALE FORCING PRECIPITATION PROBABILITIES SHOULD BE
MARKEDLY HIGHER DURING THE EVENING AND OVERNIGHT PERIOD...ESPECIALLY
ACROSS THE EASTERN PORTION OF THE FORECAST AREA. A COLD FRONT FORCED
BY A NORTHERN STREAM WAVE WILL REACH OUR AREA BY WEDNESDAY MORNING
WITH UNCERTAINTY INCREASING SOMEWHAT BY THIS TIME. THE BOUNDARY WILL
PROBABLY PROGRESS SLOWLY SOUTHWARD THROUGH THE AREA BY EVENING WITH
WEAK ISENTROPIC LIFT ATOP SHALLOW COOL LAYER RESULTING IN
CONVECTION. HAVE DIMINISHED PROBABILITIES OVERNIGHT AS MOIST UPGLIDE
OVER THE BOUNDARY WEAKENS AND MID LEVEL HEIGHTS RISE SOME.
CONFIDENCE IS A LITTLE HIGHER IN THE EXTENDED GIVEN BETTER AGREEMENT
OF MEDIUM RANGE DETERMINISTIC GUIDANCE AND LESS SPREAD IN THE
ENSEMBLE MEMBERS. BY THURSDAY A MUCH MORE SIGNIFICANT MID-UPPER
TROUGH IN THE SOUTHWEST APPROACHES CAUSING A FAIRLY DRAMATIC SURFACE
RESPONSE THROUGH FRIDAY. STRENGTHENING LEE TROUGH/LOW WILL RESULT IN
INCREASED LOW-LEVEL MOIST FLOW AGAIN AND WITH MIXING BY THURSDAY
AFTERNOON THE DRYLINE WILL SHARPEN ACROSS THE AREA. THE BEST
OPPORTUNITY FOR PRECIPITATION WITH THIS SYSTEM WILL BE THURSDAY
AFTERNOON AND EVENING AHEAD OF SHARPENING DRYLINE WHICH SEEMS MOST
LIKELY TO BE POSITIONED NORTH-SOUTH ACROSS THE CENTRAL PORTION OF
THE PANHANDLES.
GIVEN THE PROGRESSIVE NATURE OF THIS SYSTEM A PERIOD OF POST-DRYLINE
DEEP MIXING MAY OCCUR FRIDAY AFTERNOON WITH CONCERNS FOR FIRE WEATHER
POSSIBLY DEVELOPING THEN. BY THE WEEKEND IN THE WAKE OF THIS WAVE A
QUASI-ZONAL UPPER FLOW PATTERN EVOLVES WITH SOME FAIRLY SIZABLE
PERTURBATIONS SHOWING UP IN MEDIUM RANGE GUIDANCE...PARTICULARLY
AROUND SUNDAY. ALTHOUGH TIMING IS UNCERTAIN AT THIS POINT IN
TIME...DID MAINTAIN LOW PRECIPITATION PROBABILITIES ON SUNDAY.
BRB
&&
.PRELIMINARY POINT TEMPS/POPS...
AMARILLO TX 43 76 49 73 51 / 40 20 30 20 20
BEAVER OK 43 76 48 63 48 / 30 10 30 40 20
BOISE CITY OK 39 73 45 63 47 / 30 10 30 30 20
BORGER TX 46 77 53 72 52 / 50 20 30 30 20
BOYS RANCH TX 43 78 47 74 50 / 40 20 20 20 20
CANYON TX 43 77 47 75 50 / 20 20 20 20 20
CLARENDON TX 46 76 50 74 52 / 20 20 30 30 20
DALHART TX 41 75 44 70 47 / 50 10 30 30 20
GUYMON OK 41 76 46 64 48 / 30 10 30 40 20
HEREFORD TX 43 78 43 80 49 / 20 10 20 20 20
LIPSCOMB TX 45 75 52 65 50 / 30 20 40 40 20
PAMPA TX 44 74 49 69 50 / 50 20 40 30 20
SHAMROCK TX 47 75 52 70 53 / 30 20 40 40 30
WELLINGTON TX 47 77 55 74 54 / 20 20 40 40 20
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
03/15
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
1239 AM CDT SUN APR 19 2015
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...WIND SPEEDS ARE DECREASING AS TEMPERATURES COOL
TONIGHT. CLEAR SKIES WILL OPEN UP FOR SOME AREAS OF GROUND FOG TO
DEEPEN THROUGH THE NIGHT AND REFLECTED THAT IN THE TAFS. BRO/HRL
WILL LIKELY CONTINUE TO GET WORSE THROUGH THE NIGHT BUT MFE MAY
HOLD ON VFR MOST OF THE EVENING WITH A LARGER SFC DEWPOINT
DEPRESSION. DRIER AIR JUST ABOVE THE SURFACE SHOULD ALLOW
CONDITIONS TO IMPROVE PRETTY QUICKLY THROUGH MID MORNING. THERE IS
A CONDITIONAL RISK FOR CONVECTION MAINLY THIS AFTERNOON. /68-JGG/
&&
.PREV DISCUSSION... /ISSUED 633 PM CDT SAT APR 18 2015/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...A FEW SHOWERS HAVE ATTEMPTED TO GET GOING OVER THE
COASTAL COUNTIES OF DEEP SOUTH TEXAS...HOWEVER THEY HAVE LARGELY
FIZZLED OUT DUE TO A MORE STABLE ATMOSPHERE AIDED BY THE FRIDAY
EVENING/NIGHT CONVECTION. CURRENT SATELLITE IMAGERY DOESN/T SHOW
ANY CONVECTION IN THE VICINITY OF THE AERODROMES AND THIS HAS
BEEN REMOVED FROM THE PREVIOUS TAFS. SURFACE WINDS WILL LIKELY
REMAIN TOO STRONG OVERNIGHT TO ALLOW FOR SIGNIFICANT FORMATION OF
FOG...BUT A TEMPO HAS BEEN INCLUDED FOR LIGHT FOG DEVELOPMENT FOR
NEAR SUNRISE SUNDAY MORNING. PREVIOUSLY-LOWER CEILINGS HAVE BEEN
BEEN DUMPED IN FAVOR OF THE MID AND HIGH LEVEL CLOUDINESS
STREAMING OVERHEAD OUT OF NEIGHBORING MEXICO. OVERALL...VFR
SHOULD BE THE RULE THROUGH THE NEXT 24 HOURS.
PREV DISCUSSION... /ISSUED 255 PM CDT SAT APR 18 2015/
SHORT TERM.../NOW THROUGH SUNDAY NIGHT/...A LOW PRESSURE SYSTEM
CENTERED OVER EASTERN COLORADO IS MAINTAINING A BROAD AREA OF
DIFFLUENT FLOW ALOFT OVER SOUTH CENTRAL TEXAS. ALSO ...A VERY
ACTIVE SUB TROPICAL JET WITH SHORTWAVES WITHIN THE FLOW IS MOVING
ACROSS SOUTH TX UNDERNEATH THIS LOW. THIS WILL CONTINUE TO PRODUCE
NUMEROUS SHOWERS AND THUNDERSTORMS ALONG THE LOWER TEXAS GULF
WATERS NORTHEAST INTO THE NORTHWEST GULF COAST. THERE IS AN AREA
OF CONVECTION DEVELOPING ALONG A STATIONARY FRONT WHICH IS
INTERACTING WITH PLENTY OF DEEP LAYER MOISTURE AND INSTABILITY
POOLED ALONG IT. NEAR THE SURFACE DEW POINTS RANGE FROM 70 TO 75
DEGREES AND PRECIPITABLE WATER VALUES IN THE LAST KBRO 12Z
SOUNDING SHOWS 1.96 INCHES AND THE LATEST RAP MODEL RUN SHOWS
PWATS OF 1.5 TO 1.9 INCHES ESPECIALLY FROM HIDALGO COUNTY
NORTHEAST AND EAST TOWARDS THE COAST. IN ADDITION...THE A SLIGHT
BREAK IN THE CLOUDS IS ALLOWING FOR TEMPS TO WARM UP FOR THE NEXT
FEW HOURS RESULTING IN INCREASE INSTABILITY ACROSS THE AREA. THIS
WILL RESULT IN A CONTINUATION OF THE CONVECTION IN THE LATE
AFTERNOON THROUGH THE OVERNIGHT HOURS THROUGH MIDNIGHT. THE
CONVECTION WILL ALSO BE ENHANCE ALONG THE SIERRA MADRE AND MOVE
NORTHEAST WHICH WILL MAKE ITS WAY INTO STARR AND HIDALGO COUNTY
LATE EVENING INTO THE OVERNIGHT. THE MAIN THREAT WITH THESE STORMS
WILL BE VERY HEAVY DOWNPOURS PRODUCING FLOODING...STRONG DAMAGING
WINDS...HAIL AND FREQUENT CG LIGHTNING. INTO SUNDAY THE UPPER
LEVEL JET WILL MAKE ITS WAY INTO SOUTH TEXAS PROVIDING SUPPORT FOR
SOME CONVECTION TO DEVELOP SUNDAY AFTERNOON. EXPECT THE BEST
POTENTIAL TO REMAIN ALONG THE COAST DUE TO THE INSTABILITY IN THE
AREA. EXPECT A FEW OF THE STORMS TO BECOME SEVERE. THE CLOSED LOW
BECOMES AN OPEN WAVE AS IT MOVES NORTHEAST INTO THE GREAT LAKES
SUNDAY NIGHT PUSHING A COLD FRONT BEHIND IT ALONG THE CENTRAL
PLAINS. THE CONVECTION WILL BE ENHANCE EVEN MORE OVERNIGHT SUNDAY
ASSOCIATED TO THE BOUNDARY AS THE FRONT APPROACHES THE AREA. THE
FRONT WILL ARRIVED BY THE END OF THE SHORT TERM OVER THE NORTHERN
RANCHLANDS EARLY MONDAY MORNING.
LONG TERM.../MONDAY THROUGH SATURDAY/...THE CLOSED LOW THAT
HAS BEEN PLAUGING THE REGION WITH INTERMITTENT THUNDERSTORMS FOR
THE LAST SEVERAL DAYS OPENS UP AND MERGES WITH A SHARP SHORTWAVE
TROUGH UPPER TROUGH MOVING OUT OF CANADA. THE RESULT WILL BE A
LARGE SCALE UPPER TROUGH DEVELOPING MONDAY INTO TUESDAY FROM THE
NORTHERN PLAINS TO THE MIDWEST EXTENDING SOUTH INTO THE GULF
SOUTH. THIS SENDS A COLD FRONT THROUGH SOUTH TEXAS SUNDAY NIGHT
MOVING OFFSHORE THE LOWER TEXAS COAST AS EARLY AS SUNRISE MONDAY.
MODELS ARE IN GOOD AGREEMENT AND REMAIN VERY CONSISTENT WITH THE
EVOLUTION OF THE UPPER LEVEL AND SURFACE FEATURES. MODERATE TO
HIGH CONFIDENCE IN THE FORECAST THROUGH TUESDAY MAINTAINS A
LOWERING OF TEMPERATURES AND HIGHER CHANCES OF RAINFALL. THE
COOLING OF THE LOWER ATMOSPHERE, LOWER LAPSE RATES, WEAKENING
INSTABILITY WILL LIMIT THE THUNDERSTORM INTENSITY AND SEVERE
WEATHER PROBABILITIES GO WAY LOW. GFS MODEL SOUNDING CONTINUE TO
INDICATE THE BEST CHANCE OF THUNDER MONDAY MORNING AS THE FRONTAL
BOUNDARY PASSES THROUGH BUT AS THE COOLER SURFACE AIR SETTLES IN
THE INSTABILITY QUICKLY WEAKENS. ANY THUNDERSTORMS THAT LINGER
INTO THE MONDAY AFTERNOON AND EVENING WILL BE ELEVATED.
AS WE MOVE INTO TUESDAY AND THE REST OF THE WEEK THE FRONT
INITIALLY REMAINS STATIONARY NEAR OR JUST SOUTH OF THE REGION
KEEPING A MOIST EASTERLY FLOW AND POSSIBLY THE HIGHEST CHANCE OF
RAIN. BOTH GFS AND ECMWF INDICATE ON AVERAGE THAT TUESDAY WILL
HAVE THE BEST COVERAGE OF RAIN. THIS WILL ALSO KEEP TEMPERATURES
BELOW NORMAL.
AFTER TUESDAY FORECAST TRENDS DOWNWARD ON THE RAIN AND UP
WITH THE TEMPERATURES. THE FRONT EVENTUALLY DISSIPATES OR MOVES
BACK NORTH AS SHORTWAVE RIDGING BUILDS OVER WESTERN TEXAS WITH THE
NEXT UPPER TROUGH APPROACHING THE PACIFIC COAST. GFS AND ECMWF DO
LITTLE WITH THIS TROUGH AND IT LOOKS MUCH WEAKER THEN THE LAST FEW
TROUGHS. SOME PERTURBATIONS DO ADVANCE THROUGH THE TROUGH AND
RIDE ALONG STOUT SOUTHWESTERLY UPPER JET AND MAY SPARK SOME
AFTERNOON CONVECTION OVER THE SIERRA MADRE AND THEN DRIFT INTO OUR
CWA EACH AFTERNOON AND EVENING. THIS WILL BE INDICATED BY LOW
GRADE POPS EACH LATE DAY AND EVENING.
MARINE...NOW THROUGH SUNDAY NIGHT...THE SOUTHEAST WINDS WILL
REMAIN LIGHT TO VARIABLE WITH LOW SEAS ACROSS THE GULF WATERS. THE
MAIN CONCERNED THROUGH THE SHORT TERM WILL CONTINUE TO BE THE
CONVECTION OVER THE GULF. THERE IS ENOUGH INSTABILITY IN THE AREA
FROM A STATIONARY BOUNDARY PARALLEL TO THE COAST THAT WILL ENHANCE
MORE CONVECTION INCREASING LATE THIS AFTERNOON AND CONTINUE
OVERNIGHT. SUNDAY...THE POTENTIAL FOR CONVECTION WILL BEGIN TO
DEVELOP IN THE AFTERNOON AND CONTINUE OVERNIGHT AS A COLD FRONT IS
EXPECTED TO ARRIVED EARLY MONDAY INCREASING THE CHANCE OF RAIN
EVEN MORE AND SHIFTING WINDS NORTHERLY.
MONDAY THROUGH THURSDAY...COLD FRONT STILL ON TAP FOR EARLY
MONDAY AS HIGH PRESSURE BUILDS DOWN THE CENTRAL PLAINS AS A MID
LEVEL TROUGH DEEPENS INTO THE GULF SOUTH STATES. NORTHEAST WINDS
INCREASE APPROACHING SMALL CRAFT ADVISORY CONDITIONS MONDAY
AFTERNOON. SEAS TO RESPOND AND BUILD UPWARDS TO 6 FEET BY MONDAY
NIGHT. MODERATE NORTHEAST TO EAST WINDS PERSIST TUESDAY AS THE
FRONT BECOMES STATIONARY AND HIGH PRESSURE EXPANDS OVER THE
CENTRAL GULF. A RETURN TO SOUTHEAST WINDS WEDNESDAY WITH A GRADUAL
INCREASE THROUGH THE END OF THE WEEK IS EXPECTED. SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS MONDAY AND TUESDAY WITH
DECREASING COVERAGE MID TO LATE WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL 72 77 72 78 / 30 40 40 40
BROWNSVILLE 72 78 72 80 / 30 50 40 40
HARLINGEN 71 80 70 79 / 40 50 40 40
MCALLEN 72 80 71 79 / 30 50 40 40
RIO GRANDE CITY 71 80 68 78 / 30 40 50 60
SOUTH PADRE ISLAND 72 76 72 76 / 30 40 40 40
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
68/60
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1137 PM CDT SAT APR 18 2015
.DISCUSSION...
SEE 06Z AVIATION DISCUSSION.
&&
.AVIATION...
A LINE OF SHRA/TSRA WILL MOVE ACROSS THE NORTHERN TAF SITES BEFORE
06Z AND A PERIOD OF LIGHT RAIN WILL LIKELY PERSIST THROUGH 08S IN
THE WAKE OF THIS LINE. THINGS ARE A BIT MORE MUDDLED AS TO HOW FAR
SOUTH THIS LINE OF PRECIP WILL MOVE. LATEST HRRR SHOWS AN EASTWARD
PUSH TO THE NORTHERN HALF AND A SOUTHWARD PUSH TO THE WESTERN HALF
OF THE LINE. THE LINE IS STILL GENERATING WIND GUSTS BETWEEN 30-40
KNOTS SO FEEL IT IS BEST TO CARRY VCTS AND TEMPO A WIND GUST GROUP
AS FAR AS KHOU AND KSGR. THE COLD POOL/PRESSURE RISES LOOK STRONG
ENOUGH TO SUPPORT THE HRRR SOLUTION FURTHER SOUTH. WINDS WILL
LIKELY BECOME W-SW OVERNIGHT AND SW ON SUNDAY IN RESPONSE TO LOW
PRESSURE MOVING EAST ALONG THE RED RIVER. THE HRRR/GFS ADVERTISE A
TIGHT GRADIENT IN THE AFTN SO ADDED GUSTS TO THE NORTHERN TAF
SITES CLOSER TO THE TIGHTER GRADIENT. A COLD FRONT WILL APPROACH
SE TX ON SUN AFTN. NAM 12 FCST SOUNDINGS SHOW AN UNSTABLE
ATMOSPHERE OVER THE NORTH. JET DYNAMICS LOOK FAVORABLE WITH SE TX
LYING IN A LFQ BETWEEN 18-00Z. HAVE ADDED VCTS FOR KCXO
NORTHWARD. SOUNDINGS NOT QUITE AS UNSTABLE FOR THE HOUSTON
TERMINALS TOMORROW AFTN BUT THIS COULD CHANGE. ONE LAST
CAVEAT...IF SKIES CLEAR TONIGHT...WOULD EXPECT FOG TO DEVELOP BUT
JUST NOT SURE HOW MUCH CLEARING WILL OCCUR IN THE WAKE OF TONIGHTS
STORMS. 43
&&
.PREV DISCUSSION... /ISSUED 857 PM CDT SAT APR 18 2015/
DISCUSSION...
WATCHING A LINE OF STRONG/SEVERE STORMS HEADING TOWARD OUR WESTERN
COUNTIES THIS EVENING. AT THIS TIME...SPC WAS NOT PLANNING ON ISSUING
ANY WATCHES WITH THIS STORM COMPLEX. IF THE LATEST RUN OF THE HRRR
IS CORRECT...EXPECT THESE STORMS TO WEAKEN AS THEY MOVE INTO AND
ACROSS OUR AREA. 42
PREV DISCUSSION... /ISSUED 445 PM CDT SAT APR 18 2015/
DISCUSSION...
SENT OUT AN UPDATED FORECAST PACKAGE AND RAISED POPS AREA WIDE DUE
TO ONGOING/DEVELOPING CONVECTION ACROSS THE COASTAL COUNTIES AND
OFF THE COAST...AND FOR DEVELOPING STORMS OUT WEST THAT THE MODELS
HAVE MOVING INTO THE AREA THIS EVENING. SOME OF THE STORMS COULD
HAVE THE POTENTIAL TO BECOME STRONG OR SEVERE...WITH DAMAGING WINDS...
LARGE HAIL...AND LOCALLY HEAVY RAINFALL THE PRIMARY SEVERE WEATHER
THREATS. 42
MARINE...
AN UPPER LEVEL DISTURBANCE WILL GENERATE SCATTERED TO NUMEROUS
SHOWERS AND THUNDERSTORMS ACROSS THE COASTAL WATERS THIS EVENING.
SOME STORMS COULD BE STRONG. OTHERWISE...ONSHORE FLOW WILL PERSIST
THROUGH SUNDAY. A COLD FRONT WILL PUSH OFF THE COAST SUNDAY NIGHT
WITH MODERATE OFFSHORE WINDS IN ITS WAKE. WINDS WILL DIMINISH AND
VEER BACK TO THE SOUTHEAST BY LATE TUESDAY NIGHT AS HIGH PRESSURE
PUSHES OFF TO THE EAST. 47
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 63 85 56 75 54 / 60 20 10 10 20
HOUSTON (IAH) 64 85 61 78 57 / 50 20 20 10 10
GALVESTON (GLS) 69 81 66 77 66 / 50 20 20 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...42
AVIATION/MARINE...43
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
412 PM EDT SUN APR 19 2015
.SYNOPSIS...
LOW PRESSURE OVER WESTERN KENTUCKY WITH A WARM FRONT EXTENDING EAST
AND COLD FRONT TRAILING SOUTHWARD FROM THE LOW WILL LIFT NORTHEAST
TONIGHT INTO MONDAY. A COLD FRONT CROSSES THE REGION ON
MONDAY...THEN HIGH PRESSURE BUILDS IN FOR TUESDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF 333 PM EDT SUNDAY...
FLOOD WATCHES REMAIN IN EFFECT INTO TONIGHT.
A WARM FRONT TO OUR SOUTH WILL LIFT NORTH THIS EVENING AND CROSS THE
FORECAST AREA TONIGHT. DEEPER MOISTURE AND HIGHER PWATS WILL
INCREASE IN THE WARM ADVECTION WITH THE NORTHWARD ADVANCE OF THE
FRONT. THE REGIONAL RADAR IMAGE SHOWED WIDESPREAD CONVECTION ACROSS
THE MID ATLANTIC REGION SOUTHWARD TO THE SOUTHEAST US. THERE ARE
SOME CONCERNS OF STRONG CONVECTION ACROSS GEORGIA THIS AFTERNOON MAY
TAKE SOME OF THE MOISTURE AWAY FROM OUR AREA. OUR LOCAL RNK
WRFARW...HIRESW-ARW...NAM AND GFS WAIT UNTIL AFTER 00Z BEFORE
BRINGING IN HEAVIER CONVECTION THIS EVENING...WHILE HRRR AND ECMWF
ARE A LITTLE FASTER WITH TIMING. THE HRRR AND HIRESW-ARW LIFTS THE
PRECIPITATION NORTHEAST WITH MOST OF RAIN PULLING OUT BY 06-08Z.
USED A BLEND OF HRRR AND NAM FOR POPS...TAPERING POPS BACK AFTER 06Z
TONIGHT INTO MONDAY MORNING.
NOT EXPECTING ANY STRONG THUNDERSTORMS THIS AFTERNOON INTO TONIGHT
WITH CLOUD COVER HINDERING INSTABILITIES. HOWEVER...THE LOW LEVEL
JET INCREASING TO 50-60 KNOTS FROM THE SOUTHEAST WILL RESULT IN
STRONG UPSLOPE AND ISENTROPIC LIFT. THE STRONG WINDS THROUGH A
DEEP LAYER WILL PROVIDE LARGE HELICITY VALUES LATE THIS AFTERNOON
INTO THIS EVENING. THE DAY ONE CONVECTIVE OUTLOOK (SWODY1) PLACED
A MARGINAL (5 PERCENT CHANCE OF WIND) ACROSS SOUTHWEST PORTION OF
CWA. PLAYED LOW TEMPERATURES CLOSE TO ADJMAV WITH READINGS FROM
THE UPPER 40S IN THE NORTHWEST MOUNTAINS TO AROUND 60 DEGREES IN
THE PIEDMONT.
A WARM...MOIST AND UNSTABLE AIRMASS EXPECTED MONDAY. THE ATMOSPHERE
WILL DESTABILIZE AHEAD OF THE APPROACHING COLD FRONT WITH SHOWERS
AND THUNDERSTORMS DEVELOPING MONDAY. INITIALLY CUT BACK POPS CLOSER
TO NAM FOR MONDAY MORNING...THEN INCREASED TO LIKELY BY MONDAY
AFTERNOON. SPC CONTINUES OUR SLIGHT RISK FOR MONDAY ACROSS MOST OF
OUR CWA. THIS IS SUPPORTED BY THE DYNAMIC ENVIRONMENT WITH HEALTHY
SHEAR AND DECENT CAPES AROUND 2K. IT WILL ALSO BE QUITE BREEZY WITH
EFFICIENT DOWNWARD MOMENTUM TRANSFER IN A WELL MIXED BOUNDARY LAYER.
THE FRONT SHOULD BE CLEARING MONDAY NIGHT. HIGH TEMPERATURES MONDAY
WILL RANGE FROM THE MID 60S IN THE MOUNTAINS TO THE LOWER 80S IN THE
PIEDMONT.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
AS OF 345 PM EDT SUNDAY...
TAIL END OF COLD FRONT AND ASSOCIATED CONVECTION WILL BE EXITING
THE AREA JUST AFT 00Z. HOWEVER...A BROAD UPPER TROUGH...ALMOST
WINTERLIKE PATTERN CONTINUES TO EVOLVE AND DEEPEN ACROSS THE
GREAT LAKES WITH NUMEROUS SPOKES OF PVA/SHORT WAVES REMAINING
UPSTREAM. THIS LEAVES THE REGION...ESPECIALLY THE MOUNTAINS...WITH
A VERY UNSETTLED PATTERN. AT A MINIMUM...EXPECT VARIABLE
CLOUDINESS. TIMING OF EMBEDDED DISTURBANCES WILL BE THE KEY TO THE
TIMES FOR THE BETTER CHANCES OF SHOWERS. FOR SEVERAL DAYS...THE
GFS HAS INSISTED ON A SIGNIFICANT DISTURBANCE MOVING THROUGH THE
REGION WED WITH WIDESPREAD -SHRA AS A RESULT. THE OTHER MODELS
REMAIN LACKLUSTER WITH THIS FEATURE...BUT DO SUGGEST AT LEAST SOME
SMALL CHANCE WITHIN THIS TIME FRAME. GIVEN THE UNSETTLED NATURE OF
THE PATTERN WITH UPSLOPE FLOW AND VERY DIFFICULT TO TIME UPPER
DISTURBANCES...CANNOT REALLY DROP POPS AT ANY TIME. BEST FOCUS
THROUGH THE PERIOD WILL REMAIN WEST OF THE BLUE RIDGE...AND
ESPECIALLY ACROSS THE MOUNTAINS OF WV/FAR SW VA. IN
ADDITION...ENOUGH INSTABILITY SUGGESTED WITH COLD AIR ALOFT...TO
INTRODUCE ISOLD TSRA WITH THE WED DISTURBANCE AS WELL.
850MB TEMPS DROP TO NEAR 0C ACROSS THE NORTHERN PART OF THE
FORECAST AREA BY WED...BUT THE BETTER COLD ADVECTION COMES IN THE
EXTENDED PERIOD BEHIND THE WED DISTURBANCE.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 400 PM EDT SUNDAY...
BROAD UPPER TROUGH REMAINS IN PLACE AND DOMINATES THE EXTENDED
FORECAST...GRADUALLY SHIFTING FURTHER ESE LATE IN THE PERIOD.
THIS KEEPS THE REGION IN AN UNSTABLE/UNSETTLED NORTHWEST FLOW WITH
NUMEROUS EMBEDDED SHORT WAVES. MODELS VARY CONSIDERABLY AS TO THE
TIMING AND PLACEMENT OF THESE DISTURBANCES...BUT ENOUGH AGREEMENT
THAT POPS CANNOT BE DROPPED REALLY AT ANY TIME THE OVERALL TREND
IS TO PUSH THE BETTER MOISTURE FURTHER SOUTH OF THE REGION AS THE
WEEK PROGRESSES AND 850MB TEMPS DROP BELOW 0C IN THE NORTHERN
COUNTIES. THE ENTIRE PERIOD SHOULD FEATURE BELOW NORMAL
TEMPERATURES WITH LOW CHC POPS...HIGHEST ACROSS THE MOUNTAINS AND
TOWARD THE SOUTHERN COUNTIES...WITH THE NORTHERN PIEDMONT THE
DRIEST. ALTHOUGH TEMPERATURES WILL BE BELOW NORMAL THROUGHOUT THE
PERIOD...NO REAL CLEAR CONCERN AT THIS POINT FOR FROST/FREEZE
BECAUSE OF CYCLONIC FLOW AND CLOUDS.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
AS OF 142 PM EDT SUNDAY...
KFCX WSR-88D SHOWED RAIN SPREADING NORTHEAST ACROSS THE FORECAST
AREA THIS AFTERNOON...AS A WARM FRONT LIFTS NORTH ACROSS THE
REGION. CEILINGS WILL LOWER TO MVFR AND IFR WITH RAIN.
A STRONG SOUTHEAST LOW LEVEL JET WILL CONTINUE TO INCREASE THIS
AFTERNOON AND TONIGHT WHICH WILL BRING WIND GUSTS AS HIGH AS 30
KTS. WITH A WEDGE OF HIGH PRESSURE IN PLACE ALONG AND EAST OF THE
BLUE RIDGE...AFTER SUNSET THESE STRONG WINDS ARE NOT EXPECTED TO
REACH THE SURFACE. SHORTEN THE TIME WINDOW AND KEPT LLWS IN THE
KLWB AND KBCB TAFS AFTER 00Z/8PM.
CEILINGS WILL LOWER TO IFR THIS EVENING INTO TONIGHT AND WILL
REMAIN LOW OVERNIGHT. A COLD FRONT APPROACHES LATER MONDAY
WITH SOME THUNDERSTORMS POSSIBLE AHEAD OF AND ALONG THE
FRONT...ESPECIALLY EAST OF THE BLUE RIDGE. THIS IS LIKELY TO KEEP
PERIODS OF MVFR AND BRIEF IFR IN STORMS UNTIL THE FRONT CLEARS THE
REGION MONDAY EVENING.
MEDIUM CONFIDENCE IN CEILINGS...VISIBILITIES AND WINDS DURING THE
TAF PERIOD.
EXTENDED AVIATION...
VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH
PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS.
THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY AND THURSDAY.
&&
.HYDROLOGY...
AS OF 330 PM EDT SUNDAY...
HAVE EXPANDED THE FLOOD WATCH FOR THE ALLEGHANY HIGHLANDS OF
VIRGINIA.
A DEEP LAYER FROM THE SURFACE THROUGH MID LEVELS OF THE
ATMOSPHERE OF SOUTHEAST WINDS...WILL BE INCREASING TO AROUND 50
KNOTS LATER THIS AFTERNOON AND EVENING. PRECIPITABLE WATER VALUES
JUST ABOVE 1.5 INCHES WILL BE ADVECTED INTO THE FORECAST AREA. THE
STRONGEST LIFT AND HIGHEST RAINFALL AMOUNTS WILL BE FROM 18Z/2PM
THROUGH 06Z/2AM SO HAVE ADDED HEAVY RAIN TO THE FORECAST ALONG THE
BLUE RIDGE FOR THIS TIME FRAME.
TOTAL RAINFALL AMOUNTS WILL RANGE FROM 1 TO 3 INCHES THROUGH
12Z/8AM MONDAY. FLASH FLOOD GUIDANCE VALUES WERE ROUGHLY 1.5 TO
2.5 INCHES FOR 3 HOURS. SO THIS AMOUNT OF RAINFALL HAS THE
POTENTIAL TO PRODUCE FLOODING ON SMALL STREAMS AND CREEKS.
PROBABILISTIC GUIDANCE FOR MAINSTEM RIVERS SUGGESTS A SMALL
POSSIBILITY FOR MINOR FLOODING ALONG THE DAN RIVER AND NEW RIVER.
HOWEVER...THE IS HIGHLY DEPENDENT ON THE AMOUNT OF RAINFALL
THROUGH MONDAY MORNING.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLOOD WATCH THROUGH LATE TONIGHT FOR VAZ018>020-022>024-
033>035.
FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR VAZ009-012>017-032.
NC...FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR NCZ001>003-018>020.
WV...NONE.
&&
$$
SYNOPSIS...AMS/KK
NEAR TERM...KK
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...AMS/KK
HYDROLOGY...KK
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
334 PM EDT SUN APR 19 2015
.SYNOPSIS...
LOW PRESSURE OVER WESTERN KENTUCKY WITH A WARM FRONT EXTENDING EAST
AND COLD FRONT TRAILING SOUTHWARD FROM THE LOW WILL LIFT NORTHEAST
TONIGHT INTO MONDAY. A COLD FRONT CROSSES THE REGION ON
MONDAY...THEN HIGH PRESSURE BUILDS IN FOR TUESDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF 333 PM EDT SUNDAY...
FLOOD WATCHES REMAIN IN EFFECT INTO TONIGHT.
A WARM FRONT TO OUR SOUTH WILL LIFT NORTH THIS EVENING AND CROSS THE
FORECAST AREA TONIGHT. DEEPER MOISTURE AND HIGHER PWATS WILL
INCREASE IN THE WARM ADVECTION WITH THE NORTHWARD ADVANCE OF THE
FRONT. THE REGIONAL RADAR IMAGE SHOWED WIDESPREAD CONVECTION ACROSS
THE MID ATLANTIC REGION SOUTHWARD TO THE SOUTHEAST US. THERE ARE
SOME CONCERNS OF STRONG CONVECTION ACROSS GEORGIA THIS AFTERNOON MAY
TAKE SOME OF THE MOISTURE AWAY FROM OUR AREA. OUR LOCAL RNK
WRFARW...HIRESW-ARW...NAM AND GFS WAIT UNTIL AFTER 00Z BEFORE
BRINGING IN HEAVIER CONVECTION THIS EVENING...WHILE HRRR AND ECMWF
ARE A LITTLE FASTER WITH TIMING. THE HRRR AND HIRESW-ARW LIFTS THE
PRECIPITATION NORTHEAST WITH MOST OF RAIN PULLING OUT BY 06-08Z.
USED A BLEND OF HRRR AND NAM FOR POPS...TAPERING POPS BACK AFTER 06Z
TONIGHT INTO MONDAY MORNING.
NOT EXPECTING ANY STRONG THUNDERSTORMS THIS AFTERNOON INTO TONIGHT
WITH CLOUD COVER HINDERING INSTABILITIES. HOWEVER...THE LOW LEVEL
JET INCREASING TO 50-60 KNOTS FROM THE SOUTHEAST WILL RESULT IN
STRONG UPSLOPE AND ISENTROPIC LIFT. THE STRONG WINDS THROUGH A
DEEP LAYER WILL PROVIDE LARGE HELICITY VALUES LATE THIS AFTERNOON
INTO THIS EVENING. THE DAY ONE CONVECTIVE OUTLOOK (SWODY1) PLACED
A MARGINAL (5 PERCENT CHANCE OF WIND) ACROSS SOUTHWEST PORTION OF
CWA. PLAYED LOW TEMPERATURES CLOSE TO ADJMAV WITH READINGS FROM
THE UPPER 40S IN THE NORTHWEST MOUNTAINS TO AROUND 60 DEGREES IN
THE PIEDMONT.
A WARM...MOIST AND UNSTABLE AIRMASS EXPECTED MONDAY. THE ATMOSPHERE
WILL DESTABILIZE AHEAD OF THE APPROACHING COLD FRONT WITH SHOWERS
AND THUNDERSTORMS DEVELOPING MONDAY. INITIALLY CUT BACK POPS CLOSER
TO NAM FOR MONDAY MORNING...THEN INCREASED TO LIKELY BY MONDAY
AFTERNOON. SPC CONTINUES OUR SLIGHT RISK FOR MONDAY ACROSS MOST OF
OUR CWA. THIS IS SUPPORTED BY THE DYNAMIC ENVIRONMENT WITH HEALTHY
SHEAR AND DECENT CAPES AROUND 2K. IT WILL ALSO BE QUITE BREEZY WITH
EFFICIENT DOWNWARD MOMENTUM TRANSFER IN A WELL MIXED BOUNDARY LAYER.
THE FRONT SHOULD BE CLEARING MONDAY NIGHT. HIGH TEMPERATURES MONDAY
WILL RANGE FROM THE MID 60S IN THE MOUNTAINS TO THE LOWER 80S IN THE
PIEDMONT.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
AS OF 345 AM EDT SUNDAY...
COLDER AIR WORKING IN ON NW WINDS BEHIND THE FRONT WILL COMBINE WITH
LOW LEVEL MOISTURE TO GENERATE SOME UPSLOPE SHOWERS ACROSS THE FAR
WESTERN SLOPES MONDAY NIGHT.
A BROAD CLOSED UPPER LOW BUILDING IN OVER THE NORTHEAST US WILL THEN
KEEP COOL...BREEZY...AND UNSETTLED WEATHER CONDITIONS ACROSS THE REGION
THROUGH MIDWEEK. TUESDAY LOOKS TO BE THE BEST CHANCE FOR A BREAK IN THE
ACTION AS ANY LINGERING SHOWERS ACROSS THE FAR WEST DISSIPATE BY EARLY
MORNING. BY WEDNESDAY THE NEXT COLD FRONT WILL BE ROTATING IN FROM THE
WEST WITH A CHANCE FOR SHOWERS AND MAYBE SOME THUNDER ESPECIALLY WEST
OF THE BLUE RIDGE. TEMPERATURES TUESDAY AND WEDNESDAY WILL BE RUNNING
AT OR SLIGHTLY BELOW NORMAL WITH UPPER 50S/LOWER 60S WEST OF THE BLUE
RIDGE AND MID 60S TO AROUND 70 EAST.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 350 PM EDT SATURDAY...
MODELS IN BETTER AGREEMENT TODAY ON A DEEP AND BROAD UPPER LOW
CENTERED ACROSS THE EASTERN GREAT LAKES DOMINATING THE WEATHER
THROUGH MOST OF THE REMAINDER OF THE WORK WEEK. THIS WILL LEAVE
UNSETTLED CONDITIONS ACROSS THE MOUNTAINS...SOMEWHAT LESS SO ACROSS THE
PIEDMONT. FOLLOWING THIS DISTURBANCE COMES THE BONAFIDE COLDER AIR
WHICH PROMISES TO PUSH 850MB TEMPS DOWN TO 0C OR BELOW FOR MUCH OF THE
REMAINDER OF THE WEEK ACROSS THE NORTHERN AREAS. THE UPPER TROUGH
GRADUALLY SHIFTS MORE TOWARD THE MID-ATLANTIC LATE IN THE
PERIOD...STRENGTHENING THE NORTHWEST FLOW ACROSS THE REGION...AND
ALLOWING 850MB TEMPS TO BOTTOM OUT ACROSS THE NORTH AROUND -5C BY
SATURDAY. THIS PATTERN WILL CONTINUE TO RESULT IN A SIGNIFICANT
TEMPERATURE DIFFERENCE FROM THE WESTERN MOUNTAINS WITH CLOUDS AND
VARIABLE CLOUDS/SCATTERED SHOWERS AND MORE SUNNY/DOWNSLOPE NORTHWEST
FLOW ACROSS THE PIEDMONT. OVERALL...TEMPERATURES SHOULD AVERAGE BELOW
NORMAL THROUGH THE PERIOD...PERHAPS MUCH BELOW IN THE WEST. MEXMOS
SHOWS SEVERAL DAYS WITH HIGHS ONLY IN THE 50S/60S WEST AND LOWS IN THE
UPPER 30S TO LOWER 40S. WIND AND CLOUDS SHOULD PREVENT ANY FROST/FREEZE
CONCERN AT THIS POINT.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
AS OF 142 PM EDT SUNDAY...
KFCX WSR-88D SHOWED RAIN SPREADING NORTHEAST ACROSS THE FORECAST
AREA THIS AFTERNOON...AS A WARM FRONT LIFTS NORTH ACROSS THE
REGION. CEILINGS WILL LOWER TO MVFR AND IFR WITH RAIN.
A STRONG SOUTHEAST LOW LEVEL JET WILL CONTINUE TO INCREASE THIS
AFTERNOON AND TONIGHT WHICH WILL BRING WIND GUSTS AS HIGH AS 30
KTS. WITH A WEDGE OF HIGH PRESSURE IN PLACE ALONG AND EAST OF THE
BLUE RIDGE...AFTER SUNSET THESE STRONG WINDS ARE NOT EXPECTED TO
REACH THE SURFACE. SHORTEN THE TIME WINDOW AND KEPT LLWS IN THE
KLWB AND KBCB TAFS AFTER 00Z/8PM.
CEILINGS WILL LOWER TO IFR THIS EVENING INTO TONIGHT AND WILL
REMAIN LOW OVERNIGHT. A COLD FRONT APPROACHES LATER MONDAY
WITH SOME THUNDERSTORMS POSSIBLE AHEAD OF AND ALONG THE
FRONT...ESPECIALLY EAST OF THE BLUE RIDGE. THIS IS LIKELY TO KEEP
PERIODS OF MVFR AND BRIEF IFR IN STORMS UNTIL THE FRONT CLEARS THE
REGION MONDAY EVENING.
MEDIUM CONFIDENCE IN CEILINGS...VISIBILITIES AND WINDS DURING THE
TAF PERIOD.
EXTENDED AVIATION...
VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH
PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS.
THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY AND THURSDAY.
&&
.HYDROLOGY...
AS OF 330 PM EDT SUNDAY...
HAVE EXPANDED THE FLOOD WATCH FOR THE ALLEGHANY HIGHLANDS OF
VIRGINIA.
A DEEP LAYER FROM THE SURFACE THROUGH MID LEVELS OF THE
ATMOSPHERE OF SOUTHEAST WINDS...WILL BE INCREASING TO AROUND 50
KNOTS LATER THIS AFTERNOON AND EVENING. PRECIPITABLE WATER VALUES
JUST ABOVE 1.5 INCHES WILL BE ADVECTED INTO THE FORECAST AREA. THE
STRONGEST LIFT AND HIGHEST RAINFALL AMOUNTS WILL BE FROM 18Z/2PM
THROUGH 06Z/2AM SO HAVE ADDED HEAVY RAIN TO THE FORECAST ALONG THE
BLUE RIDGE FOR THIS TIME FRAME.
TOTAL RAINFALL AMOUNTS WILL RANGE FROM 1 TO 3 INCHES THROUGH
12Z/8AM MONDAY. FLASH FLOOD GUIDANCE VALUES WERE ROUGHLY 1.5 TO
2.5 INCHES FOR 3 HOURS. SO THIS AMOUNT OF RAINFALL HAS THE
POTENTIAL TO PRODUCE FLOODING ON SMALL STREAMS AND CREEKS.
PROBABILISTIC GUIDANCE FOR MAINSTEM RIVERS SUGGESTS A SMALL
POSSIBILITY FOR MINOR FLOODING ALONG THE DAN RIVER AND NEW RIVER.
HOWEVER...THE IS HIGHLY DEPENDENT ON THE AMOUNT OF RAINFALL
THROUGH MONDAY MORNING.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLOOD WATCH THROUGH LATE TONIGHT FOR VAZ018>020-022>024-
033>035.
FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR VAZ009-012>017-032.
NC...FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR NCZ001>003-018>020.
WV...NONE.
&&
$$
SYNOPSIS...AMS/KK
NEAR TERM...KK
SHORT TERM...MBS
LONG TERM...RAB
AVIATION...AMS/KK
HYDROLOGY...AMS/KK
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
959 AM EDT SUN APR 19 2015
.SYNOPSIS...
HIGH PRESSURE WAS OVER SOUTHEAST CANADA AND LOW PRESSURE WAS IN
ARKANSAS WITH A WARM FROM EXTENDING INTO SOUTH CAROLINA. THE LOW
AND WARM FRONT WILL MOVE NORTH TODAY AND TONIGHT. A COLD FRONT
CROSSES THE REGION ON MONDAY THEN HIGH PRESSURE BUILDS IN FOR
TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 958 AM EDT SUNDAY...
FLOOD WATCHES REMAIN IN EFFECT FROM THIS AFTERNOON INTO TONIGHT.
A WARM FRONT WILL LIFT NORTH TODAY AND CROSS THE FORECAST AREA
TONIGHT. DEEPER MOISTURE AND HIGHER PWATS WILL INCREASE IN THE
WARM ADVECTION WITH THE NORTHWARD ADVANCE OF THE FRONT. THE RNK
WRF-ARW...HIRESW-ARW AND HRRR SHOWED WIDESPREAD RAIN LIFTING
NORTHWARD ACROSS OUR AREA. LOW LEVEL JET INCREASING TO 50-60 KNOTS
FROM THE SOUTHEAST WILL RESULT IN STRONG UPSLOPE AND ISENTROPIC
LIFT. THE STRONG WINDS THROUGH A DEEP LAYER WILL PROVIDE LARGE
HELICITY VALUES LATE THIS AFTERNOON INTO THIS EVENING. THE DAY
ONE CONVECTIVE OUTLOOK (SWODY1) PLACED A MARGINAL (5 PERCENT
CHANCE OF WIND) ACROSS SOUTHWEST PORTION OF CWA. MODIFIED
TEMPERATURES...DEW POINT AND POPS FR THIS MORNING INTO THIS
AFTERNOON. MORE ADJUSTMENTS AS THE DAY PROGRESSES...
AS OF 430 AM EDT SUNDAY...
WARM FRONT ASSOCIATED WITH A LOW IN ARKANSAS WILL MOVE NORTH TODAY
AND WILL CROSS THROUGH THE FORECAST AREA TONIGHT. STRONG SYNOPTIC
SCALE LIFT WILL PRODUCE WIDESPREAD RAIN ACROSS THE FORECAST AREA.
LOW LEVEL JET INCREASING TO 50-60 KNOTS FROM THE SOUTHEAST WILL
RESULT IN STRONG UPSLOPE AND ISENTROPIC LIFT. RAIN WILL SPREAD
INTO THE AREA FROM SOUTHWEST TO NORTHEAST BEFORE 18Z/2PM. MOST
LOCATIONS WILL HAVE ABOUT A 12 HOUR PERIOD OF LIGHT TO MODERATE
RAIN. HAVE PRECIPITATION ENDING FROM SOUTHWEST TO NORTHEAST AFTER
06Z/2AM.
TEMPERATURES STARTING THE DAY QUITE MILD. GRIDDED LAMP GUIDANCE
INDICATED STEADY AND POSSIBLY SLIGHTLY FALLING TEMPERATURES TODAY.
LITTLE CHANGE IN AIR MASS IS EXPECTED TONIGHT WITH TEMPERATURES
AND DEW POINTS REMAINING MAINLY IN THE 50S.
THE STRONG WINDS THROUGH A DEEP LAYER WILL PROVIDE LARGE HELICITY
VALUES LATE THIS AFTERNOON INTO THIS EVENING. THERE IS A LOW
CHANCE THERE COULD BE ENHANCED DIRECTIONAL SHEAR AS THE WARM FRONT
CROSSES. FOR NOW WILL LEAVE OUT ANY THUNDER.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 345 AM EDT SUNDAY...
THE NEW WEEK STARTS OFF WITH OUR REGION IN A WARM AND MOIST AIRMASS. AS
TEMPERATURES RISE WELL INTO THE 70S ON MONDAY THE ATMOSPHERE WILL
DESTABILIZE AHEAD OF THE APPROACHING COLD FRONT AND THUNDERSTORMS ARE
EXPECTED TO DEVELOP. THE DYNAMIC ENVIRONMENT SUPPORTS THE CHANCE FOR
SOME SEVERE STORMS AND THE SPC SLIGHT RISK LOOKS TO BE ON TARGET ACROSS
OUR AREA WITH THE POTENTIAL FOR SVR WEATHER INCREASING EASTWARD WHERE
INSTABILITY WILL BE GREATER. IT WILL ALSO BE QUITE BREEZY WITH
EFFICIENT DOWNWARD MOMENTUM TRANSFER IN A WELL MIXED BOUNDARY LAYER.
THE FRONT SHOULD BE CLEARING THE EASTERN ZONES EARLY MONDAY EVENING.
COLDER AIR WORKING IN ON NW WINDS BEHIND THE FRONT WILL COMBINE WITH
LOW LEVEL MOISTURE TO GENERATE SOME UPSLOPE SHOWERS ACROSS THE FAR
WESTERN SLOPES MONDAY NIGHT.
A BROAD CLOSED UPPER LOW BUILDING IN OVER THE NORTHEAST US WILL THEN
KEEP COOL...BREEZY...AND UNSETTLED WEATHER CONDITIONS ACROSS THE REGION
THROUGH MIDWEEK. TUESDAY LOOKS TO BE THE BEST CHANCE FOR A BREAK IN THE
ACTION AS ANY LINGERING SHOWERS ACROSS THE FAR WEST DISSIPATE BY EARLY
MORNING. BY WEDNESDAY THE NEXT COLD FRONT WILL BE ROTATING IN FROM THE
WEST WITH A CHANCE FOR SHOWERS AND MAYBE SOME THUNDER ESPECIALLY WEST
OF THE BLUE RIDGE. TEMPERATURES TUESDAY AND WEDNESDAY WILL BE RUNNING
AT OR SLIGHTLY BELOW NORMAL WITH UPPER 50S/LOWER 60S WEST OF THE BLUE
RIDGE AND MID 60S TO AROUND 70 EAST.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
AS OF 350 PM EDT SATURDAY...
MODELS IN BETTER AGREEMENT TODAY ON A DEEP AND BROAD UPPER LOW
CENTERED ACROSS THE EASTERN GREAT LAKES DOMINATING THE WEATHER
THROUGH MOST OF THE REMAINDER OF THE WORK WEEK. THIS WILL LEAVE
UNSETTLED CONDITIONS ACROSS THE MOUNTAINS...SOMEWHAT LESS SO ACROSS THE
PIEDMONT. FOLLOWING THIS DISTURBANCE COMES THE BONAFIDE COLDER AIR
WHICH PROMISES TO PUSH 850MB TEMPS DOWN TO 0C OR BELOW FOR MUCH OF THE
REMAINDER OF THE WEEK ACROSS THE NORTHERN AREAS. THE UPPER TROUGH
GRADUALLY SHIFTS MORE TOWARD THE MID-ATLANTIC LATE IN THE
PERIOD...STRENGTHENING THE NORTHWEST FLOW ACROSS THE REGION...AND
ALLOWING 850MB TEMPS TO BOTTOM OUT ACROSS THE NORTH AROUND -5C BY
SATURDAY. THIS PATTERN WILL CONTINUE TO RESULT IN A SIGNIFICANT
TEMPERATURE DIFFERENCE FROM THE WESTERN MOUNTAINS WITH CLOUDS AND
VARIABLE CLOUDS/SCATTERED SHOWERS AND MORE SUNNY/DOWNSLOPE NORTHWEST
FLOW ACROSS THE PIEDMONT. OVERALL...TEMPERATURES SHOULD AVERAGE BELOW
NORMAL THROUGH THE PERIOD...PERHAPS MUCH BELOW IN THE WEST. MEXMOS
SHOWS SEVERAL DAYS WITH HIGHS ONLY IN THE 50S/60S WEST AND LOWS IN THE
UPPER 30S TO LOWER 40S. WIND AND CLOUDS SHOULD PREVENT ANY FROST/FREEZE
CONCERN AT THIS POINT.
&&
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
AS OF 745 AM EDT SUNDAY...
RAIN HAD ADVANCED INTO SOUTHWEST VIRGINIA AND WESTERN NORTH
CAROLINA THIS MORNING WITH CEILINGS LOWERING IN ADVANCE OF THE
RAIN. RAIN WILL BEGIN AT KBLF AROUND THE 12Z START OF THE TAF TIME
AND BY 16Z/NOON AT THE OTHER TAF SITES.
A STRONG SOUTHEAST LOW LEVEL JET WILL CONTINUE TO INCREASE TODAY
AND TONIGHT WHICH WILL BRING WIND GUSTS AS HIGH AS 30 KTS TODAY.
WITH A WEDGE OF HIGH PRESSURE IN PLACE ALONG AND EAST OF THE BLUE
RIDGE...AFTER SUNSET THESE STRONG WINDS ARE NOT EXPECTED TO REACH
THE SURFACE. HAVE LLWS IN THE KDAN...KLWB AND KBCB TAFS AFTER
00Z/8PM.
A STRONG UPSLOPE FLOW WILL TRANSPORT ABUNDANT MOISTURE INTO THE
REGION NORTH OF A STATIONARY FRONT TODAY. CEILINGS WILL LOWER TO
IFR BY THIS AFTERNOON AND WILL REMAIN LOW OVERNIGHT.
EXTENDED AVIATION...
A COLD FRONT APPROACHES LATER MONDAY WITH SOME STORMS POSSIBLE
AHEAD OF AND ALONG THE FRONT...ESPECIALLY EAST OF THE BLUE RIDGE.
THIS IS LIKELY TO KEEP PERIODS OF MVFR AND BRIEF IFR IN STORMS
UNTIL THE FRONT CLEARS THE REGION MONDAY EVENING.
VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH
PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS.
THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY AND THURSDAY.
&&
.HYDROLOGY...
AS OF 430 AM EDT SUNDAY...
HAVE EXPANDED THE FLOOD WATCH FOR MORE OF THE SOUTHERN BLUE RIDGE
AND FOR THE BLUE RIDGE AND ADJACENT EASTERN COUNTIES NORTH OF OF
ROANOKE. BUFKIT SOUNDINGS SHOWED A DEEP LAYER FROM THE SURFACE
THROUGH MID LEVELS OF THE ATMOSPHERE WITH SOUTHEAST WINDS...THAT
WILL BE INCREASING TO AROUND 50 KNOTS THIS AFTERNOON AND EVENING.
PRECIPITABLE WATER VALUES JUST ABOVE 1.5 INCHES WILL BE ADVECTED
INTO THE FORECAST AREA. THE STRONGEST LIFT AND HIGHEST RAINFALL
AMOUNTS WILL BE FROM 18Z/2PM THROUGH 06Z/2AM SO HAVE ADDED HEAVY
RAIN TO THE FORECAST ALONG THE BLUE RIDGE FOR THIS TIME FRAME.
TOTAL RAINFALL AMOUNTS WILL RANGE FROM 1 TO 3 INCHES THROUGH
12Z/8AM MONDAY. FLASH FLOOD GUIDANCE VALUES WERE ROUGHLY 1.5 TO
2.5 INCHES FOR 3 HOURS. SO THIS AMOUNT OF RAINFALL HAS THE
POTENTIAL TO PRODUCE FLOODING ON SMALL STREAMS AND CREEKS.
PROBABILISTIC GUIDANCE FOR MAINSTEM RIVERS SUGGESTS A SMALL
POSSIBILITY FOR MINOR FLOODING ALONG THE DAN RIVER AND NEW RIVER.
HOWEVER...THE IS HIGHLY DEPENDENT ON THE AMOUNT OF RAINFALL
THROUGH MONDAY MORNING.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLOOD WATCH THROUGH THIS EVENING FOR VAZ009-012>017-032.
FLOOD WATCH FROM 2 PM EDT THIS AFTERNOON THROUGH LATE TONIGHT
FOR VAZ022>024-033>035.
NC...FLOOD WATCH THROUGH THIS EVENING FOR NCZ001>003-018>020.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/KK
SHORT TERM...MBS
LONG TERM...RAB
AVIATION...AMS/PC
HYDROLOGY...AMS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
147 AM EDT SUN APR 19 2015
.SYNOPSIS...
HIGH PRESSURE WILL DRIFT EAST TONIGHT ALLOWING CLOUDS FROM LOW
PRESSURE OVER THE TENNESSEE VALLEY TO SPREAD ACROSS THE REGION
OVERNIGHT. RAIN...HEAVY AT TIMES...WILL FALL SUNDAY INTO SUNDAY
NIGHT BEFORE A COLD FRONT CROSSES THE REGION WITH A CHANCE OF
SHOWERS AND POTENTIALLY STRONG STORMS ON MONDAY. DRY AND COOL
CONDITIONS WILL PREVAIL FOR THE MIDDLE PART OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 912 PM EDT SATURDAY
STILL A FEW DIURNAL SHOWERS ALONG THE BLUE RIDGE BUT THEY ARE
FADING FAST. WILL REMOVE POPS FOR THE REST OF THE EVENING...THEN
INCREASE POPS TOWARDS SUNRISE AS LOW PRESSURE ENTERS THE
TENNESSEE VALLEY. MINOR UPDATES TO OTHER GRIDS.
PREVIOUS DISCUSSION...
AS OF 300 PM EDT SATURDAY
WEAK LOW LEVEL CONVERGENCE JUST SOUTH OF OUR FORECAST AREA HAS
IGNITED A FEW SHOWERS AND ISOLATED STORMS. THE HRRR MODEL LIFTS THIS
BOUNDARY SLIGHTLY NORTH. THIS COMBINED WITH A WEAK UPSLOPE FLOW MAY
FIRE A FEW SHOWERS AND ISOLATED STORMS SOUTH OF HIGHWAY 58 THIS
AFTERNOON AND EARLY THIS EVENING...THEREFORE KEPT A SMALL CHANCE FOR
POPS IN THE FORECAST.
ALL THE MODELS ARE IN GOOD AGREEMENT ON DEVELOPING A STRONG LOW
LEVEL SOUTHEAST JET...TRANSPORTING MOISTURE INTO THE AREA OVERNIGHT.
A FEW GUSTS OVER 30KTS WILL BE POSSIBLE IN SOUTHEAST WV/CLINCH RIVER
VALLEY VA OVERNIGHT AND SUNDAY...BUT VALUES ARE BELOW GUIDANCE
CRITERIA.
PWATS INCREASE TO 2-3 STANDARD DEVIATIONS ABOVE AVERAGE BY SUNDAY
MORNING AND THROUGH MUCH OF THE DAY SUNDAY. MEANWHILE...A LARGE AREA
UVV LIFTS NORTH INTO OUR REGION TOWARD DAWN THEN EAST OVER ENTIRE
AREA ON SUNDAY. THIS IS IN ADVANCE OF A NEGATIVELY TILTED UPPER TROF
LIFTING THROUGH THE OHIO VALLEY SUNDAY WHICH ALSO GENERATES STRONG
UPPER DIFFLUENCE. AS A RESULT...EXPECT MODERATE TO HEAVY RAIN TO FALL
FOR SEVERAL HOURS...ESPECIALLY ALONG THE EAST SLOPES OF THE BLUE
RIDGE. MORE INFORMATION ABOUT THE FLOODING POTENTIAL FROM THIS
SYSTEM CAN BE FOUND IN THE HYDROLOGY SECTION. BOTTOM LINE...A FLOOD
WATCH WILL BE POSTED FOR THE NW NC MOUNTAINS/FOOTHILLS AND SOUTHERN
BLUE RIDGE OF VA. FUTURE SHIFTS MAY NEED TO EXPAND THIS NORTH AND
EAST...IF HIGHER QPF TRENDS CONTINUE.
CONTINUED TO GO BELOW GUIDANCE FOR HIGHS SUNDAY...WITH WEDGE IN
PLACE AND WIDESPREAD CLOUDS AND PRECIPITATION. IN FACT...MANY AREAS
IN THE WEDGE LIKELY SEE LITTLE...IF ANY...RECOVERY IN TEMPS.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
AS OF 335 PM EDT SATURDAY...
HEAVIER RAINFALL ASSOCIATED WITH NORTHEASTWARD MOVING STRONGLY
NEGATIVELY TILTED UPPER TROUGH AND ASSOCIATED WARM/WEDGE FRONT
WILL MOVE INTO THE PIEDMONT THROUGH 06Z MON...THEN EAST OF THE CWA
BETWEEN 06Z AND 12Z MON. ADDITIONAL RAINFALL OF 1/2 TO 3/4 INCH
DURING THIS TIME FRAME SHOULD BE CONFINED TO THE PIEDMONT. FLOOD
WATCH ENDS AT 04Z MON...WHICH SHOULD BE GOOD TIMING. MEANWHILE...A
BROAD UPPER TROUGH CONTINUES TO DEEPEN ACROSS THE GREAT LAKES WITH
UPPER FLOW REMAINING SOUTHWEST BEHIND THE AFOREMENTIONED UPPER
TROUGH. THE NEXT UPPER SHORT WAVE WILL BE APPROACHING THE WESTERN
AREAS BY DAYBREAK MONDAY WITH A STRONG COLD FRONT MOVING INTO THE
WESTERN TN/OH VALLEY. SCATTERED SHOWERS SHOULD DEVELOP ONCE AGAIN
ACROSS THE WESTERN MOUNTAINS IN ADVANCE OF THESE FEATURES. BY
AFTERNOON...MUCH OF THE CWA...ESPECIALLY EAST OF THE BLUE RIDGE
WILL BE SOLIDLY IN THE WARM SECTOR WITH TEMPERATURES ACROSS THE
PIEDMONT NEAR 80 DEGREES AND DEWPOINTS NEAR 60. A 6-HOUR WINDOW OF
SUBSTANTIAL CAPE IN EXCESS OF 1000 J/KG...BULK 0-6KM SHEAR OF
20-30KTS...LIS TO -6 ALONG THE VA/NC BORDER...AND SIG SVR PARMS
GREATER THAN 20000 COMBINED WITH STRONG PVA AND YET ANOTHER
NEGATIVELY TILTED SHORT WAVE STRONGLY SUPPORT THE SLIGHT RISK
OUTLOOK FROM SPC EAST OF THE BLUE RIDGE MON AFTERNOON...WITH THE
MARGINAL RISK FURTHER WEST INTO THE MOUNTAINS. MAIN CONCERNS WILL
BE THUNDERSTORM WIND GUSTS AND HAIL WITH COLD AIR ALOFT ADVECTING
INTO THE REGION. A FEW MORE DISCRETE CELLS COULD DEVELOP EAST OF
THE FRONT ACROSS THE PIEDMONT IF MAXIMUM INSTABILITY/HEATING IS
REALIZED. THE SEVERE THREAT WILL END QUICKLY FROM WEST TO EAST
AFT 00Z AS THE THERMODYNAMICS WANE QUICKLY AND THE UPPER SUPPORT
SHIFTS NORTHEAST OF THE REGION. RAINFALL WILL NOT BE A CONCERN
WITH THIS SECOND EVENT AS ACTIVITY WILL BE BRIEF AND
SCATTERED...BUT A QUICK 1/2 INCH OF RAIN MAY OCCUR IN AREAS WITH
HEAVIER SHOWERS/THUNDERSTORMS. SCATTERED UPSLOPE RAIN SHOWERS
COULD PERSIST ACROSS THE MOUNTAINS INTO TUESDAY...BUT NO
SIGNIFICANT DYNAMICS ARE FORESEEN WITHIN THIS TIME FRAME.
UNSEASONABLY WARM TEMPERATURES MONDAY WILL GIVE WAY TO MUCH COOLER
CONDITIONS ACROSS THE MOUNTAINS TUESDAY WITH VARIABLE CLOUDS AND A
FEW SHOWERS...BUT DOWNSLOPE PIEDMONT AREAS SHOULD STILL BE CLOSE
TO 70 EVEN TUESDAY.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 350 PM EDT SATURDAY...
MODELS IN BETTER AGREEMENT TODAY ON A DEEP AND BROAD UPPER LOW
CENTERED ACROSS THE EASTERN GREAT LAKES DOMINATING THE WEATHER
THROUGH MOST OF THE REMAINDER OF THE WORK WEEK. THIS WILL LEAVE
UNSETTLED CONDITIONS ACROSS THE MOUNTAINS...SOMEWHAT LESS SO
ACROSS THE PIEDMONT. THE ECMWF HAS COME INTO BETTER AGREEMENT WITH
THE GFS NOW ON A DISTURBANCE ROTATING THROUGH THE BOTTOM OF THE
UPPER TROUGH WEDNESDAY...BRINGING A BETTER THREAT OF SHOWERS TO
THE REGION. THUS...HAVE INCREASED POPS IN ACCORDANCE WITH THE
BETTER MODEL AGREEMENT AND SURROUNDING OFFICES. HAVE NOT
INTRODUCED THUNDER AT THIS POINT...BUT COULD NOT TOTALLY RULE OUT
SOME THUNDER BECAUSE OF RATHER COLD AIR ALOFT. FOLLOWING THIS
DISTURBANCE COMES THE BONAFIDE COLDER AIR WHICH PROMISES TO PUSH
850MB TEMPS DOWN TO 0C OR BELOW FOR MUCH OF THE REMAINDER OF THE
WEEK ACROSS THE NORTHERN AREAS. THE UPPER TROUGH GRADUALLY SHIFTS
MORE TOWARD THE MID-ATLANTIC LATE IN THE PERIOD...STRENGTHENING
THE NORTHWEST FLOW ACROSS THE REGION...AND ALLOWING 850MB TEMPS TO
BOTTOM OUT ACROSS THE NORTH AROUND -5C BY SATURDAY. THIS PATTERN
WILL CONTINUE TO RESULT IN A SIGNIFICANT TEMPERATURE DIFFERENCE
FROM THE WESTERN MOUNTAINS WITH CLOUDS AND VARIABLE
CLOUDS/SCATTERED SHOWERS AND MORE SUNNY/DOWNSLOPE NORTHWEST FLOW
ACROSS THE PIEDMONT. OVERALL...TEMPERATURES SHOULD AVERAGE BELOW
NORMAL THROUGH THE PERIOD...PERHAPS MUCH BELOW IN THE WEST. MEXMOS
SHOWS SEVERAL DAYS WITH HIGHS ONLY IN THE 50S/60S WEST AND LOWS IN
THE UPPER 30S TO LOWER 40S. WIND AND CLOUDS SHOULD PREVENT ANY
FROST/FREEZE CONCERN AT THIS POINT.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 145 AM EDT SUNDAY...
MODELS CONTINUE TO BE CONSISTENT WITH CLOUDS AND THEN RAIN WILL
SPREAD INTO THE AREA FROM SOUTHWEST TO NORTHEAST TONIGHT. EXPECT
CEILINGS TO LOWER TO MVFR ON THE 09Z/5AM-16Z/11AM TIME RANGE.
A STRONG SOUTHEAST LOW LEVEL JET WILL DEVELOP JUST AFTER MIDNIGHT
WHICH MAY BRING WIND GUSTS TO 30 KTS TODAY. WITH A WEDGE OF HIGH
PRESSURE IN PLACE ALONG AND EAST OF THE BLUE RIDGE...AFTER SUNSET THESE
STRONG WINDS ARE NOT EXPECTED TO REACH THE SURFACE. HAVE LLWS IN
THE KDAN...KLWB AND KBCB TAFS AFTER 00Z/8PM.
A STRONG UPSLOPE FLOW WILL TRANSPORT ABUNDANT MOISTURE INTO THE
REGION NORTH OF A STATIONARY FRONT TODAY. CEILINGS WILL LOWER TO
IFR LATE THIS AFTERNOON INTO THE EVENING AND WILL REMAIN LOW
OVERNIGHT.
EXTENDED AVIATION...
A COLD FRONT APPROACHES LATER MONDAY WITH SOME STORMS POSSIBLE
AHEAD OF AND ALONG THE FRONT...ESPECIALLY EAST OF THE BLUE RIDGE.
THIS IS LIKELY TO KEEP PERIODS OF MVFR AND BRIEF IFR IN STORMS
UNTIL THE FRONT CLEARS THE REGION MONDAY EVENING.
VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH
PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS.
THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY AND THURSDAY.
&&
.HYDROLOGY...
AS OF 330 PM EDT SATURDAY...
ANTECEDENT CONDITIONS ARE STILL MOIST ACROSS THE NW NC
MOUNTAINS/FOOTHILLS INTO THE SOUTHERN BLUE RIDGE OF VA WITH THE
PERCENT OF NORMAL PRECIP OVER THE PAST WEEK EXCEEDING OVER 150%.
THIS ALSO IS SHOWN IN RIVER STAGE LEVELS ACROSS THIS REGION FROM
THE USGS WITH STREAM LEVELS IN MANY LOCATIONS RUNNING GREATER THAN
THE 75TH PERCENTILE. WITH 6 HOUR FLASH FLOOD GUIDANCE VALUES BELOW
3 INCHES IN THE REGION...AND FORECAST PW VALUES 2-3 STANDARD
DEVIATIONS ABOVE NORMAL...EXPECT FLOODING OF CREEKS AND STREAMS.
WHILE THE SREF MODEL ENSEMBLE RIVER FORECAST ONLY IS FORECASTING A
SMALL CHANCE FOR RIVERS TO REACH ACTION STAGE...WOULD NOT BE
SURPRISED TO SEE A FEW SITES REACH MINOR FLOODING CONSIDERING THE
MODEL TRENDS OF INCREASING QPF WITH EACH RUN.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLOOD WATCH THROUGH THIS EVENING FOR VAZ015>017-032.
NC...FLOOD WATCH THROUGH THIS EVENING FOR NCZ001>003-018>020.
WV...NONE.
&&
$$
SYNOPSIS...PH
NEAR TERM...PH/RCS
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...AMS/PC
HYDROLOGY...PH
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1158 AM CDT SUN APR 19 2015
UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND MONDAY
ISSUED AT 327 AM CDT SUN APR 19 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SPLIT FLOW
OVER CENTRAL NORTH AMERICA EARLY THIS MORNING. IN THE SOUTHERN
STREAM...UPPER LEVEL LOW PRESSURE IS SPINNING OVER WESTERN
KANSAS/EASTERN COLORADO. AHEAD OF THIS FEATURE...SHOWERS AND
THUNDERSTORMS ARE OCCURRING FROM NEBRASKA TO LOUISIANA. EVEN
FURTHER NORTHEAST...MID-LEVEL MOISTURE TRANSPORT AND ILL-DEFINED
SHORTWAVES ARE ALSO CREATING SHOWERS AND A FEW THUNDERSTORMS FROM
WESTERN WISCONSIN INTO ILLINOIS. A COUPLE SPOTTY SHOWERS POPPED UP
SHORTLY AFTER MIDNIGHT OVER WOOD COUNTY TO THE DELLS...AND WILL HAVE
TO CARRY AN ISOLATED MENTION EARLY THIS MORNING ACROSS THE
I-39/ROUTE 51 CORRIDOR. IN THE NORTHERN STREAM...SHORTWAVE ENERGY
IS PROGRESSING EAST OVER THE NORTHWEST PLAINS. AS THESE FEATURES
MOVE EAST...PRECIP CHANCES AND TIMING ARE THE MAIN FORECAST CONCERNS.
TODAY...LOW PRESSURE OVER THE NORTHERN PLAINS WILL HEAD EAST WHILE
THE SOUTHERN STREAM LOW WILL LIFT NORTHEAST OVER THE CENTRAL
MISSISSIPPI VALLEY. WEAK SHORTWAVE ACTIVITY ROTATING ON THE EASTERN
PERIPHERY OF THE UPPER LOW OVER WESTERN KANSAS WILL LIFT NORTH
ACROSS THE WESTERN GREAT LAKES TODAY BUT INTO A MORE STABLE AND
DRIER AIRMASS. DESPITE THIS...THE HIGHER RES MODELS AND RUC DEPICT
SPOTTY SHOWERS DEVELOPING OVER CENTRAL AND NORTHEAST WISCONSIN THIS
MORNING WHICH BEAR SOME WEIGHT GIVEN THE SPOTTY SHOWERS POPPING UP
OVER THE DELLS AT THIS HOUR. AS A RESULT...QUITE DIFFICULT TO ADD
MUCH TEMPORAL RESOLUTION TO THE FORECAST THIS MORNING OTHER THAN
SAYING SLIGHT CHANCE OF A SHOWER. FORCING INCREASES OVER WESTERN
WISCONSIN DURING THE AFTERNOON WHEN A FGEN BAND MOVES ACROSS THAT
PART OF THE STATE. THE EASTERN EDGE OF THE INDUCED RAIN BAND WILL
LIKELY BE PUSHING INTO N-C WISCONSIN LATE IN THE AFTERNOON. AM
THINKING EASTERN WISCONSIN WILL REMAIN MOSTLY DRY DUE TO NE FLOW. THE
SLOWER ARRIVAL OF THE PRECIP WILL HELP TEMPERATURES RISE INTO THE
MID 60S OVER CENTRAL WI. CLOUD COVER AND EAST WINDS WILL SUPPORT
MUCH COOLER READINGS OVER EASTERN WI THOUGH.
TONIGHT...THE MEDIUM RANGE MODELS TRACK THE SOUTHERN STREAM SURFACE
LOW FROM CENTRAL ILLINOIS/INDIANA TO NORTHERN LOWER MICHIGAN. SOME
POSSIBILITY THAT THE LOW WILL TRACK WEST OF THIS LINE IN THE
MESOMODELS THOUGH. COMMA HEAD PRECIP FROM THIS LOW LOOKS TO MOVE
INTO NORTHEAST WISCONSIN BY MID TO LATE EVENING. MEANWHILE...RAIN
BAND ASSOCIATED WITH MID-LEVEL FGEN AHEAD OF THE NORTHERN STREAM
WAVE WILL SHIFT EAST THROUGH THE NIGHT ACROSS CENTRAL AND EASTERN
WISCONSIN. SEEMS LIKE A GOOD RECIPE FOR PERIODS OF RAIN ACROSS THE
REGION. LOWS RANGING FROM THE UPPER 30S NORTH TO MID 40S SOUTH.
MONDAY...THE FGEN RAIN BAND WILL GRADUALLY BE WEAKENING AS IT MOVES
EAST ACROSS EASTERN WISCONSIN DURING THE MORNING AND EXITS DURING
THE AFTERNOON. THE MID-LEVEL DRY SLOT WILL WORK OVERHEAD IN THE
WAKE OF THE RAIN DURING THE AFTERNOON AND MAY SEE A FEW PEAKS OF
SUNSHINE. OTHERWISE...BECOMING BREEZY WITH HIGHS IN THE MID 40S
NORTH TO LOW 50S SOUTH.
.LONG TERM...MONDAY NIGHT THROUGH SATURDAY
ISSUED AT 327 AM CDT SUN APR 19 2015
CLOSED UPPER LOW WILL BRING UNSETTLED AND COOL CONDITIONS TO THE
REGION TUESDAY INTO WEDNESDAY. THE UPPER LOW WILL GRADUALLY PULL
AWAY THURSDAY AND FRIDAY...BUT CYCLONIC FLOW COULD STILL BRING A
SMALL CHANCE OF PRECIPITATION THURSDAY INTO FRIDAY ACROSS THE
FAR NORTH. DESPITE THE CALENDER STATING ITS LATE APRIL...SOME SNOW
IS IN THE FORECAST LATE AT NIGHT INTO THE MORNING HOURS. COULD BE SOME
MINOR ACCUMULATION ACROSS THE FAR NORTH TUESDAY MORNING AND AGAIN
WEDNESDAY MORNING.
BELOW NORMAL TEMPERATURES WILL CONTINUE INTO NEXT WEEKEND WITH DRY
CONDITIONS EXPECTED ON FRIDAY. ONLY MINOR CHANGES MADE TO PRECIPITATION
CHANCES AND TEMPERATURES DURING THE PERIOD.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1146 AM CDT SUN APR 19 2015
BROKEN MIDLEVEL CIGS CONTINUE THIS AFTERNOON INTO THE
EVENING...THOUGH VFR CONDITIONS SHOULD PREVAIL. LOW PRESSURE THEN
MOVE ACROSS THE GREAT LAKES REGION TONIGHT AND WILL RESULT IN
AN AREA OF STEADY RAIN OVERNIGHT. PRECIP SHOULD BE SLOWER TO
ARRIVE THAN PREVIOUSLY FORECASTED...WITH RAIN ARRIVING LATE EARLY
TONIGHT THROUGH MIDNIGHT. LOW END IFR CONDITIONS ARE EXPECTED WITH
THIS AREA OF RAIN...WITH LIFR CIGS POSSIBLE AS CURRENT OBS IN
AREA OF INCOMING PRECIP IN IL/IN SHOW SCATTERED CIGS BELOW 500FT.
LIFR CONDITIONS IN CURRENT RAIN NOT WIDESPREAD ENOUGH AND GUIDANCE
WAFFLING ON HOW LOW CIGS WILL GO...SO NOT ENOUGH CONFIDENCE TO ADD
IT TO THE TAFS AT THIS TIME...BUT WILL BE SOMETHING TO MONITOR.
HEAVIEST RAIN AND WORST CONDITIONS WILL LIKELY BE OVER EASTERN TAF
SITES.
RAIN WILL TAPER OFF MONDAY MORNING IN NORTH-CENTRAL WISCONSIN
WITH MVFR CIGS POSSIBLE BY THE SECOND HALF OF THE MORNING. LIGHT
RAIN WILL CONTINUE FURTHER EAST WITH IFR CONDITIONS MOST LIKELY
HOLDING TIGHT UNTIL LATER IN THE MORNING. WINDS WILL BACK FROM
SOUTHEAST THIS AFTERNOON...TO NORTH OVERNIGHT...TO NORTHEAST
MONDAY AS A COLD FRONT SWEEPS THROUGH THE STATE.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......ECKBERG
AVIATION.......ALLEN
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
551 AM CDT SUN APR 19 2015
UPDATED AVIATION PORTION FOR 12Z TAF ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND MONDAY
ISSUED AT 327 AM CDT SUN APR 19 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SPLIT FLOW
OVER CENTRAL NORTH AMERICA EARLY THIS MORNING. IN THE SOUTHERN
STREAM...UPPER LEVEL LOW PRESSURE IS SPINNING OVER WESTERN
KANSAS/EASTERN COLORADO. AHEAD OF THIS FEATURE...SHOWERS AND
THUNDERSTORMS ARE OCCURRING FROM NEBRASKA TO LOUISIANA. EVEN
FURTHER NORTHEAST...MID-LEVEL MOISTURE TRANSPORT AND ILL-DEFINED
SHORTWAVES ARE ALSO CREATING SHOWERS AND A FEW THUNDERSTORMS FROM
WESTERN WISCONSIN INTO ILLINOIS. A COUPLE SPOTTY SHOWERS POPPED UP
SHORTLY AFTER MIDNIGHT OVER WOOD COUNTY TO THE DELLS...AND WILL HAVE
TO CARRY AN ISOLATED MENTION EARLY THIS MORNING ACROSS THE
I-39/ROUTE 51 CORRIDOR. IN THE NORTHERN STREAM...SHORTWAVE ENERGY
IS PROGRESSING EAST OVER THE NORTHWEST PLAINS. AS THESE FEATURES
MOVE EAST...PRECIP CHANCES AND TIMING ARE THE MAIN FORECAST CONCERNS.
TODAY...LOW PRESSURE OVER THE NORTHERN PLAINS WILL HEAD EAST WHILE
THE SOUTHERN STREAM LOW WILL LIFT NORTHEAST OVER THE CENTRAL
MISSISSIPPI VALLEY. WEAK SHORTWAVE ACTIVITY ROTATING ON THE EASTERN
PERIPHERY OF THE UPPER LOW OVER WESTERN KANSAS WILL LIFT NORTH
ACROSS THE WESTERN GREAT LAKES TODAY BUT INTO A MORE STABLE AND
DRIER AIRMASS. DESPITE THIS...THE HIGHER RES MODELS AND RUC DEPICT
SPOTTY SHOWERS DEVELOPING OVER CENTRAL AND NORTHEAST WISCONSIN THIS
MORNING WHICH BEAR SOME WEIGHT GIVEN THE SPOTTY SHOWERS POPPING UP
OVER THE DELLS AT THIS HOUR. AS A RESULT...QUITE DIFFICULT TO ADD
MUCH TEMPORAL RESOLUTION TO THE FORECAST THIS MORNING OTHER THAN
SAYING SLIGHT CHANCE OF A SHOWER. FORCING INCREASES OVER WESTERN
WISCONSIN DURING THE AFTERNOON WHEN A FGEN BAND MOVES ACROSS THAT
PART OF THE STATE. THE EASTERN EDGE OF THE INDUCED RAIN BAND WILL
LIKELY BE PUSHING INTO N-C WISCONSIN LATE IN THE AFTERNOON. AM
THINKING EASTERN WISCONSIN WILL REMAIN MOSTLY DRY DUE TO NE FLOW. THE
SLOWER ARRIVAL OF THE PRECIP WILL HELP TEMPERATURES RISE INTO THE
MID 60S OVER CENTRAL WI. CLOUD COVER AND EAST WINDS WILL SUPPORT
MUCH COOLER READINGS OVER EASTERN WI THOUGH.
TONIGHT...THE MEDIUM RANGE MODELS TRACK THE SOUTHERN STREAM SURFACE
LOW FROM CENTRAL ILLINOIS/INDIANA TO NORTHERN LOWER MICHIGAN. SOME
POSSIBILITY THAT THE LOW WILL TRACK WEST OF THIS LINE IN THE
MESOMODELS THOUGH. COMMA HEAD PRECIP FROM THIS LOW LOOKS TO MOVE
INTO NORTHEAST WISCONSIN BY MID TO LATE EVENING. MEANWHILE...RAIN
BAND ASSOCIATED WITH MID-LEVEL FGEN AHEAD OF THE NORTHERN STREAM
WAVE WILL SHIFT EAST THROUGH THE NIGHT ACROSS CENTRAL AND EASTERN
WISCONSIN. SEEMS LIKE A GOOD RECIPE FOR PERIODS OF RAIN ACROSS THE
REGION. LOWS RANGING FROM THE UPPER 30S NORTH TO MID 40S SOUTH.
MONDAY...THE FGEN RAIN BAND WILL GRADUALLY BE WEAKENING AS IT MOVES
EAST ACROSS EASTERN WISCONSIN DURING THE MORNING AND EXITS DURING
THE AFTERNOON. THE MID-LEVEL DRY SLOT WILL WORK OVERHEAD IN THE
WAKE OF THE RAIN DURING THE AFTERNOON AND MAY SEE A FEW PEAKS OF
SUNSHINE. OTHERWISE...BECOMING BREEZY WITH HIGHS IN THE MID 40S
NORTH TO LOW 50S SOUTH.
.LONG TERM...MONDAY NIGHT THROUGH SATURDAY
ISSUED AT 327 AM CDT SUN APR 19 2015
CLOSED UPPER LOW WILL BRING UNSETTLED AND COOL CONDITIONS TO THE
REGION TUESDAY INTO WEDNESDAY. THE UPPER LOW WILL GRADUALLY PULL
AWAY THURSDAY AND FRIDAY...BUT CYCLONIC FLOW COULD STILL BRING A
SMALL CHANCE OF PRECIPITATION THURSDAY INTO FRIDAY ACROSS THE
FAR NORTH. DESPITE THE CALENDER STATING ITS LATE APRIL...SOME SNOW
IS IN THE FORECAST LATE AT NIGHT INTO THE MORNING HOURS. COULD BE SOME
MINOR ACCUMULATION ACROSS THE FAR NORTH TUESDAY MORNING AND AGAIN
WEDNESDAY MORNING.
BELOW NORMAL TEMPERATURES WILL CONTINUE INTO NEXT WEEKEND WITH DRY
CONDITIONS EXPECTED ON FRIDAY. ONLY MINOR CHANGES MADE TO PRECIPITATION
CHANCES AND TEMPERATURES DURING THE PERIOD.
&&
.AVIATION...FOR 12Z TAF ISSUANCE
ISSUED AT 551 AM CDT SUN APR 19 2015
BROKEN MID-LEVEL CLOUDS THROUGH THIS AFTERNOON WITH
SPOTTY SHOWERS POSSIBLE. THEN AS LOW PRESSURE MOVES ACROSS THE
REGION TONIGHT...STEADY RAIN WILL MOVE ACROSS THE TAF SITES
BEGINNING THIS EVENING AND CONTINUING FOR MUCH OF THE NIGHT. EXPECT
CIGS AND VSBYS TO LOWER ONCE THE RAIN ARRIVES. IFR CIGS LOOK
LIKELY...AND SOME THREAT OF LIFR CIGS BASED ON UPSTREAM OBS OVER THE
NORTHERN PLAINS AND MOS GUIDANCE.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......ECKBERG
AVIATION.......MPC
FORECAST DISCUSSION FOR ROUTINE MORNING FORECAST ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND MONDAY
ISSUED AT 327 AM CDT SUN APR 19 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SPLIT FLOW
OVER CENTRAL NORTH AMERICA EARLY THIS MORNING. IN THE SOUTHERN
STREAM...UPPER LEVEL LOW PRESSURE IS SPINNING OVER WESTERN
KANSAS/EASTERN COLORADO. AHEAD OF THIS FEATURE...SHOWERS AND
THUNDERSTORMS ARE OCCURRING FROM NEBRASKA TO LOUISIANA. EVEN
FURTHER NORTHEAST...MID-LEVEL MOISTURE TRANSPORT AND ILL-DEFINED
SHORTWAVES ARE ALSO CREATING SHOWERS AND A FEW THUNDERSTORMS FROM
WESTERN WISCONSIN INTO ILLINOIS. A COUPLE SPOTTY SHOWERS POPPED UP
SHORTLY AFTER MIDNIGHT OVER WOOD COUNTY TO THE DELLS...AND WILL HAVE
TO CARRY AN ISOLATED MENTION EARLY THIS MORNING ACROSS THE
I-39/ROUTE 51 CORRIDOR. IN THE NORTHERN STREAM...SHORTWAVE ENERGY
IS PROGRESSING EAST OVER THE NORTHWEST PLAINS. AS THESE FEATURES
MOVE EAST...PRECIP CHANCES AND TIMING ARE THE MAIN FORECAST CONCERNS.
TODAY...LOW PRESSURE OVER THE NORTHERN PLAINS WILL HEAD EAST WHILE
THE SOUTHERN STREAM LOW WILL LIFT NORTHEAST OVER THE CENTRAL
MISSISSIPPI VALLEY. WEAK SHORTWAVE ACTIVITY ROTATING ON THE EASTERN
PERIPHERY OF THE UPPER LOW OVER WESTERN KANSAS WILL LIFT NORTH
ACROSS THE WESTERN GREAT LAKES TODAY BUT INTO A MORE STABLE AND
DRIER AIRMASS. DESPITE THIS...THE HIGHER RES MODELS AND RUC DEPICT
SPOTTY SHOWERS DEVELOPING OVER CENTRAL AND NORTHEAST WISCONSIN THIS
MORNING WHICH BEAR SOME WEIGHT GIVEN THE SPOTTY SHOWERS POPPING UP
OVER THE DELLS AT THIS HOUR. AS A RESULT...QUITE DIFFICULT TO ADD
MUCH TEMPORAL RESOLUTION TO THE FORECAST THIS MORNING OTHER THAN
SAYING SLIGHT CHANCE OF A SHOWER. FORCING INCREASES OVER WESTERN
WISCONSIN DURING THE AFTERNOON WHEN A FGEN BAND MOVES ACROSS THAT
PART OF THE STATE. THE EASTERN EDGE OF THE INDUCED RAIN BAND WILL
LIKELY BE PUSHING INTO N-C WISCONSIN LATE IN THE AFTERNOON. AM
THINKING EASTERN WISCONSIN WILL REMAIN MOSTLY DRY DUE TO NE FLOW. THE
SLOWER ARRIVAL OF THE PRECIP WILL HELP TEMPERATURES RISE INTO THE
MID 60S OVER CENTRAL WI. CLOUD COVER AND EAST WINDS WILL SUPPORT
MUCH COOLER READINGS OVER EASTERN WI THOUGH.
TONIGHT...THE MEDIUM RANGE MODELS TRACK THE SOUTHERN STREAM SURFACE
LOW FROM CENTRAL ILLINOIS/INDIANA TO NORTHERN LOWER MICHIGAN. SOME
POSSIBILITY THAT THE LOW WILL TRACK WEST OF THIS LINE IN THE
MESOMODELS THOUGH. COMMA HEAD PRECIP FROM THIS LOW LOOKS TO MOVE
INTO NORTHEAST WISCONSIN BY MID TO LATE EVENING. MEANWHILE...RAIN
BAND ASSOCIATED WITH MID-LEVEL FGEN AHEAD OF THE NORTHERN STREAM
WAVE WILL SHIFT EAST THROUGH THE NIGHT ACROSS CENTRAL AND EASTERN
WISCONSIN. SEEMS LIKE A GOOD RECIPE FOR PERIODS OF RAIN ACROSS THE
REGION. LOWS RANGING FROM THE UPPER 30S NORTH TO MID 40S SOUTH.
MONDAY...THE FGEN RAIN BAND WILL GRADUALLY BE WEAKENING AS IT MOVES
EAST ACROSS EASTERN WISCONSIN DURING THE MORNING AND EXITS DURING
THE AFTERNOON. THE MID-LEVEL DRY SLOT WILL WORK OVERHEAD IN THE
WAKE OF THE RAIN DURING THE AFTERNOON AND MAY SEE A FEW PEAKS OF
SUNSHINE. OTHERWISE...BECOMING BREEZY WITH HIGHS IN THE MID 40S
NORTH TO LOW 50S SOUTH.
.LONG TERM...MONDAY NIGHT THROUGH SATURDAY
ISSUED AT 327 AM CDT SUN APR 19 2015
CLOSED UPPER LOW WILL BRING UNSETTLED AND COOL CONDITIONS TO THE
REGION TUESDAY INTO WEDNESDAY. THE UPPER LOW WILL GRADUALLY PULL
AWAY THURSDAY AND FRIDAY...BUT CYCLONIC FLOW COULD STILL BRING A
SMALL CHANCE OF PRECIPITATION THURSDAY INTO FRIDAY ACROSS THE
FAR NORTH. DESPITE THE CALENDER STATING ITS LATE APRIL...SOME SNOW
IS IN THE FORECAST LATE AT NIGHT INTO THE MORNING HOURS. COULD BE SOME
MINOR ACCUMULATION ACROSS THE FAR NORTH TUESDAY MORNING AND AGAIN
WEDNESDAY MORNING.
BELOW NORMAL TEMPERATURES WILL CONTINUE INTO NEXT WEEKEND WITH DRY
CONDITIONS EXPECTED ON FRIDAY. ONLY MINOR CHANGES MADE TO PRECIPITATION
CHANCES AND TEMPERATURES DURING THE PERIOD.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1014 PM CDT SAT APR 18 2015
CLOUDS WILL CONTINUE TO THICKEN AND LOWER THROUGH THE
NIGHT AND EARLY SUNDAY MORNING AS LOW PRESSURE SYSTEMS APPROACH
FROM THE WEST AND SOUTH. RAIN IS EXPECTED TO BEGIN LATER SUNDAY
MORNING ACROSS THE WEST AND SUNDAY AFTERNOON ACROSS THE EASTERN
TAF SITES. TIMING OF THE RAIN SHOWERS IS A BIT TENUOUS AS THERE
REMAINS SIGNIFICANT DIFFERENCES BETWEEN THE NWP MODELS.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......ECKBERG
AVIATION.......KURIMSKI
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
953 PM MDT MON APR 20 2015
.UPDATE...
ISSUED AT 953 PM MDT MON APR 20 2015
MAIN CONCERN OVERNIGHT IS CERTAINLY THE POTENTIAL FOR FOG
DEVELOPMENT FOR AREAS WEST OF THE LARAMIE RANGE...INCLUDING I-80
BETWEEN RAWLINS AND LARAMIE. 00Z NAM IS KEEPING FOG AT BAY WITH
LOW BL HUMIDITIES AND A DRIER NEAR SURFACE LAYER BASED OFF THE
KLAR FORECAST SOUNDINGS. HRRR IS ALSO CONSISTENTLY SHOWING NO
DEVELOPMENT OF FOG OVERNIGHT. BASED ON THIS ENSEMBLE OF
GUIDANCE...AND SOME MID CLOUDS DEVELOPING AND MOVING IN FROM THE
NORTHWEST WITH A FORECAST WIND DIRECTION FROM THE SOUTHWEST...AM
NOT SO CONFIDENT WIDESPREAD DENSE FOG WILL DEVELOP OVERNIGHT.
LINGERING SNOWPACK AND LIGHT WINDS WILL CERTAINLY AID IN
DEVELOPMENT OF MORE PATCHY AREAS OF FOG ESPECIALLY LATE IN THE
NIGHT IN THE LARAMIE VALLEY...WITH VISIBILITIES DROPPING TO
PERHAPS ONE HALF MILE OR SO...BUT A WIDESPREAD EVENT SEEMS
UNLIKELY AT THIS TIME. THE HIGHEST PROBABILITY OF FOG WILL BE FOR
EASTERN AND SOUTHERN PORTIONS OF THE LARAMIE VALLEY...AND PERHAPS
NORTHERN CARBON COUNTY AS WELL. WILL HOLD OF ON ISSUING A DENSE
FOG ADVISORY FOR NOW DUE TO LOW CONFIDENCE...BUT WILL CLOSELY
MONITOR THE SITUATION.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 250 PM MDT MON APR 20 2015
TONIGHT...LOOKS LIKE ENOUGH INSTABILITY IN THE THETA E RIDGE ACROSS
OUR FAR SOUTHWEST COUNTIES FOR ISOLATED TO WIDELY SCATTERED EARLY
EVENING SHOWERS OVER SOUTHERN CARBON AND ALBANY COUNTIES. DRY
ELSEWHERE. BASED ON PERSISTENCE...WILL AGAIN FORECAST AREAS OF FOG
OVERNIGHT AND ESPECIALLY AFTER MIDNIGHT FOR MUCH OF CARBON COUNTY
AND ESPECIALLY OVER THE LARAMIE VALLEY AND THE SNOWPACK WHERE
TEMPERATURE AND DEWPOINT SPREADS ARE STILL ONLY 2 DEGREES AT MID
AFTERNOON.
TUESDAY...NON DESCRIPT NORTHWEST FLOW ALOFT CONTINUES. LOOKS LIKE
ENOUGH LOW AND MID LEVEL MOISTURE ALONG WITH DIFFERENTIAL HEATING
AND UPSLOPE TO GENERATE ISOLATED TO WIDELY SCATTERED AFTERNOON
SHOWERS...WITH ISOLATED THUNDERSTORMS WEST OF INTERSTATE 25.
TUESDAY NIGHT...SHOWERS AND THUNDERSTORMS SHOULD END IN THE EVENING
WITH THE LOSS OF DAYTIME HEATING AND LACK OF SIGNIFICANT
LIFTING...THOUGH STILL ENOUGH LOW AND MID LEVEL MOISTURE FOR
SCATTERED TO BROKEN CLOUD COVER...AND AREAS OF FOG ONCE AGAIN OVER
THE LARAMIE VALLEY.
WEDNESDAY...TRANSITORY RIDGING ALOFT MOVES OVERHEAD. STILL
THOUGH...ENOUGH LOW AND MID LEVEL MOISTURE AND INSTABILITY FOR
ISOLATED TO SCATTERED AFTERNOON SHOWERS AND THUNDERSTORMS WITH AN
INCREASE IN THUNDERSTORM COVERAGE DUE TO INCREASED INSTABILITY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 250 PM MDT MON APR 20 2015
SHORTWAVE RIDGE MOVES OVER THE AREA WEDNESDAY NIGHT. MOST AREAS
EAST OF THE LARAMIE RANGE WILL BE DRY...THOUGH GFS DOES SHOW SOME
LIGHT SHOWERS OUT OVER CARBON COUNTY INTO THURSDAY MORNING.
RIDGE AXIS MOVES EAST OF THE CWFA THURSDAY WITH AN UPPER SHORTWAVE
PUSHING INTO NORTHWESTERN COLORADO AND WESTERN WYOMING. BOTH THE
GFS AND ECMWF PAINTING MODERATE QPF OVER THE CWFA THURSDAY
AFTERNOON. LIFTED INDICES -2 TO -4C ACROSS THE CWFA WITH -5 TO -6C
ACROSS THE PANHANDLE. ADDED THUNDERSTORM MENTION IN THE FORECAST
FOR THURSDAY AFTERNOON/EVENING.
FRIDAY COULD BE AN INTERESTING DAY THUNDERSTORM WISE AS A SURFACE
LOW DEVELOPS OVER NORTHEASTERN COLORADO. UPPER LEVEL LOW ALMOST
VERTICALLY STACKED OVER THE SURFACE LOW ON BOTH THE GFS AND
ECMWF. GFS MOST BULLISH ON QPF...WITH AN AREA OVER HEAVY RAIN OVER
THE SOUTHERN PANHANDLE. LOW SLOW TO MOVE OUT OF THE AREA WITH
SHOWER ACTIVITY CONTINUING INTO SATURDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 420 PM MDT MON APR 20 2015
GUSTY WEST AND NORTHWEST WINDS DECREASING BY EARLY THIS EVENING
WITH RELATIVELY LIGHT WINDS OVERNIGHT. SCATTERED TO BROKEN
CLOUDS TONIGHT FROM 4000 TO 8000 FEET AGL. AREAS OF FOG...WITH
VISIBILITIES AT OR BELOW ONE MILE AT LARAMIE FROM 06Z TO 15Z WITH
CEILINGS BELOW 1000 FEET AGL.
NORTH AND NORTHWEST WINDS 20 TO 30 KNOTS DEVELOPING AGAIN TUESDAY
BY LATE MORNING AND CONTINUING IN THE AFTERNOON WITH ISOLATED
TO SCATTERED SHOWERS DEVELOPING.
&&
.FIRE WEATHER...
ISSUED AT 250 PM MDT MON APR 20 2015
RECENT RAIN AND CONTINUED SNOW PACK FROM LAST WEEKS STORM WILL
KEEP FIRE WEATHER CONCERNS MINIMAL THROUGH THE WEEK. GOING TO SEE
INCREASED CHANCES FOR WETTING RAINS AND MOUNTAIN SNOWS LATE IN THE
WEEK AS ANOTHER PACIFIC LOW PRESSURE SYSTEM TRACKS ACROSS NORTHERN
COLORADO.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...RJM
SHORT TERM...RUBIN
LONG TERM...GCC
AVIATION...RUBIN
FIRE WEATHER...GCC
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1123 PM MDT SAT APR 18 2015
.UPDATE...
ISSUED AT 1108 PM MDT SAT APR 18 2015
CLOUD TOPS CONTINUE TO WARM ON IR IMAGERY...AND THE BAND OF
MODERATE SNOW HAS SHIFTED EAST MORE INTO CENTRAL/SOUTHERN ALBANY
COUNTY AND WESTERN LARAMIE COUNTY...SO ALLOWED THE WINTER
HIGHLIGHTS TO EXPIRE.
UPDATE ISSUED AT 945 PM MDT SAT APR 18 2015
THE BAND OF MODERATE TO LOCALLY HEAVY SNOW CONTINUES TO SLOWLY
SHIFT EAST THIS EVENING...BUT PERHAPS SLIGHTLY SLOWER THAN
PREVIOUS THINKING. EARLIER ANALYSIS SUGGESTED A FEW STRONGER SNOW
SHOWERS WERE PERSISTING FROM THE NORTHERN LARAMIE RANGE SOUTHWEST
THROUGH THE ARLINGTON AREA AND ON UP INTO THE SNOWY RANGE AND
SOUTHERNMOST AREAS OF THE SIERRA MADRE MOUNTAINS. SHORT TERM
MODELS ALSO SUGGESTED THAT THE BAND WOULD MOVE SLOW TO THE EAST
THIS EVENING... SO FELT IT PRUDENT TO EXTEND THE WINTER STORM
WARNING AND ADVISORY FOR A FEW MORE HOURS AS SNOW WOULD CONTINUE
TO IMPACT THESE LOCATIONS. ENDED THE HEADLINES AT 11PM AS IR
IMAGERY IS SHOWING A RAPID WARMING OF CLOUD TOPS...AND MODELS
SUGGEST THE BAND WILL HAVE WEAKENED AND SHIFTED ENOUGH TO THE EAST
TO CANCEL ALL WINTER HEADLINES AT THIS TIME.
ALSO...ADDED AREAS OF FOG TO THE SUMMIT THROUGH MIDNIGHT AS
WEBCAMS SHOWED THE DEVELOPMENT OF FOG EARLIER...AND HRRR KEEPS
THE FOG AROUND THROUGH 11PM-12AM.
.UPDATE ISSUED AT 546 PM MDT SAT APR 18 2015
TORNADO WATCH HAS BEEN CANCELLED. CONDITIONS ARE NO LONGER
FAVORABLE FOR TORNADO DEVELOPMENT IN THE SOUTHERN NEBRASKA
PANHANDLE WITH THE BOUNDARY LAYER STABILIZING. A FEW
THUNDERSTORMS AREA STILL POSSIBLE OVER THE NEXT FEW HOURS INTO
SOUTHEAST WYOMING AND PANHANDLE BUT SEVERE WEATHER IS VERY
UNLIKELY. A ROUGE FUNNEL CLOUD AND SMALL HAIL STILL POSSIBLE FOR
THE NEXT HOUR OR SO.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 440 PM MDT SAT APR 18 2015
LOTS OF WEATHER CONCERNS OVER THE NEXT 12 HOURS. HEAVY SNOW
CONTINUES IN A NARROW BAND...MAINLY ACROSS EASTERN/CENTRAL CARBON
COUNTY...STRETCHING NORTHEAST INTO THE NORTHERN LARAMIE RANGE. ON
EITHER SIDE OF THE HEAVY BAND...MAINLY LOOKING AT LIGHT NON
ACCUMULATING SNOW OR RAIN. THIS WILL CONTINUE TO BE THE CASE UNTIL
LATE THIS EVENING WHEN THE DEFORMATION AXIS BEGINS TO SHIFT EAST
AS THE NORTHWEST FLOW KICKER PUSHES THE UPPER LOW INTO THE PLAINS.
THE BAND WILL SHIFT EAST LATE THIS EVENING INTO THE OVERNIGHT
HOURS BUT IT WILL ALSO WEAKEN SUBSTANTIAL WILL LITTLE IN THE WAY
OF ADDITION MEASURABLE PRECIPITATION AFTER MIDNIGHT ANYWHERE IN
THE FORECAST AREA.
SHOWERS AND THUNDERSTORMS HAVE DEVELOPED OVER THE PLAINS. A
TORNADO WATCH IS IN EFFECT FOR MORRILL AND CHEYENNE COUNTY IN THE
SOUTHERN NEBRASKA PANHANDLE UNTIL 8 PM MDT. BASED ON RADAR TRENDS
AND CURRENT ATMOSPHERIC ENVIRONMENT...ANY TORNADO THREAT IS
RAPIDLY DECREASING. CURRENT SHOWER ACTIVITY WILL RAPIDLY
STABILIZE THE BOUNDARY LAYER. ALSO...LIMITED SHEAR IS ONLY
SUPPORTIVE OFF VERY SHORT LIVED AND WEAK TORNADIC ACTIVITY. WOULD
NOT BE SURPRISED TO SEE A FEW FUNNEL CLOUD REPORTS WITH
DEVELOPING SHOWERS AND THUNDERSTORMS AS THE OVERALL ENVIRONMENT IS
MORE SUPPORTIVE OF FUNNEL CLOUDS BUT THAT TOO WILL QUICKLY WANE
OVER THE NEXT FEW HOURS.
ANOTHER CONCERN FOR TONIGHT IS NORTHERN WINDS WHICH WILL RAMP UP
THIS EVENING INTO THE OVERNIGHT AS A COLD FRONT MOVES ACROSS THE
AREA. COULD SEE A SHORT PERIOD OF NASTY WINTER CONDITIONS...MAINLY
INTO THE SOUTHERN LARAMIE RANGE AND CHEYENNE AS THE SNOW BAND
SHIFTS EAST AND INTERACTS WITH STRONG GUSTY NORTHERN WINDS. NAM
AND GFS BUFKIT SOUNDINGS AROUND MIDNIGHT SHOWING 45 TO 50 KT
WINDS AT CHEYENNE NOT TOO FAR OFF THE SURFACE. VERY WELL COULD SEE
A 3 TO 4 HOUR PERIOD WITH LOW VISIBILITIES DUE TO FALLING SNOW AND
GUSTY WINDS. FORTUNATELY THIS WILL BE SHORT LIVED IF IT THIS
COMBINATIONS DOES INDEED OCCUR. ALSO WINDS SPEEDS WILL APPROACH
WIND ADVISORY LEVELS INTO THE NEBRASKA PANHANDLE LATER TONIGHT
AND INTO SUNDAY AFTERNOON. DID NOT ISSUE ANY WIND HEADLINES GIVEN
WINTER WEATHER AND CONVECTIVE HEADLINES...BUT A WIND ADVISORY MAY
BE NEEDED EVENTUALLY.
QUIETER WEATHER ACROSS THE AREA SUNDAY WITH THE UPPER LOW OUT OF
THE PICTURE. KEPT SOME LOW POPS GOING ACROSS THE WEST DURING THE
DAY SUNDAY...BUT IT IS LOOKING LESS AND LESS LIKELY FOR ANY
MEASURABLE PRECIPITATION FOR MOST OF SUNDAY. MAIN CHANCES WILL BE
WITH NORTHERN STREAM SHORTWAVE AND UPPER LEVEL JET ENERGY WHICH
SHOULD IMPACT THE SNOWY AND SIERRA MADRES SUNDAY NIGHT.
ACCUMULATIONS WILL BE MINIMAL.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 250 PM MDT SAT APR 18 2015
MEDIUM TO LONG RANGE MODELS IN FAIR AGREEMENT THROUGH THE MIDDLE
OF NEXT WEEK...WITH SOME DISAGREEMENT REGARDING THE TRACK AND
EVOLUTION OF A DEVELOPING LOW PRESSURE SYSTEM LIFTING NORTHEAST
ACROSS THE CENTRAL AND SOUTHERN ROCKY MOUNTAINS BY THURSDAY AND
FRIDAY. FOR EARLY NEXT WEEK...ALL MODELS SHOW NORTHWEST FLOW
INITIALLY WITH RELATIVELY DRY CONDITIONS LASTING INTO EARLY
WEDNESDAY. A WEAK SHORTWAVE TROUGH WILL PUSH ACROSS THE REGION
EMBEDDED IN THE NORTHWEST FLOW...BUT OUTSIDE OF SOME MOUNTAIN/HIGH
VALLEY RAIN AND SNOW SHOWERS...DO NOT EXPECT ANYTHING SIGNIFICANT
WITH HIGH TEMPERATURES ABOUT 10 TO 15 DEGREES COOLER THAN SEASONAL
AVERAGES. TEMPERATURES WILL FINALLY MODERATE SOME BY TUES AND
ESPECIALLY INTO WED...BACK INTO THE UPPER 50S TO UPPER 60S TO THE
EAST OF THE LARAMIE RANGE. A SURFACE HIGH WILL BUILD OVER THE
GREAT PLAINS LATE WEDNESDAY AND ON THURSDAY...RESULTING IN WINDS
VEERING INTO THE EAST AND SOUTHEAST. KEPT TSTORMS IN THE FORECAST
FOR THURSDAY WEST OF THE LARAMIE RANGE...BUT KEPT SHOWERS FURTHER
EAST DUE TO A PERSISTENT LLVL STRATUS DECK.
MODELS STRUGGLING WITH A SHORTWAVE DISTURBANCE LIFTING NORTHEAST
OUT OF ARIZONA THURSDAY NIGHT. 12Z GFS ATTEMPTS TO FORM A CLOSED
LOW ACROSS THE NORTH CENTRAL PLAINS OF COLORADO BY EARLY
FRIDAY...WITH PRECIP EXTENDING INTO THE I80 CORRIDOR OF SOUTHEAST
WYOMING AND WESTERN NEBRASKA. THE ECMWF ON THE OTHER HAND IS MUCH
FURTHER SOUTH...MAINLY SHOWING THE FEATURE ACROSS NORTHERN NEW
MEXICO LIFTING NORTHEAST INTO KANSAS BY FRIDAY. KEPT A 20 TO 30
PERCENT CHANCE OF RAIN AND HIGH ELEVATION SNOW FOR FRIDAY AND EARLY
SATURDAY MORNING.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
AREAS OF MVFR AND IFR CIGS WILL AFFECT MOST TERMINALS OVERNIGHT WITH
SOME RAIN AND SNOW EARLY IN THE PERIOD. GUSTY SFC WINDS EXPECTED
ESPECIALLY OVER THE PLAINS TONIGHT AND SUNDAY. CIGS IMPVG DURING
THE DAY SUNDAY.
&&
.FIRE WEATHER...
ISSUED AT 250 PM MDT SAT APR 18 2015
SHOWERS AND THUNDERSTORMS WILL END ACROSS ACROSS THE PLAINS
TONIGHT WITH SNOW ENDING OVER HIGHER ELEVATIONS OF WYOMING AS THE
UPPER LEVEL DISTURBANCE SHIFTS EAST INTO THE CENTRAL PLAINS.
WARMING TREND THROUGH MID WEEK BUT GENERALLY ON THE COOLER SIDE
AND DRY. NEXT CHANCE FOR WIDESPREAD PRECIPITATION IS LATE NEXT
WEEK...MAYBE.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...RJM
SHORT TERM...SML
LONG TERM...TJT
AVIATION...RE
FIRE WEATHER...SML
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1108 PM MDT SAT APR 18 2015
.UPDATE...
ISSUED AT 1108 PM MDT SAT APR 18 2015
CLOUD TOPS CONTINUE TO WARM ON IR IMAGERY...AND THE BAND OF
MODERATE SNOW HAS SHIFTED EAST MORE INTO CENTRAL/SOUTHERN ALBANY
COUNTY AND WESTERN LARAMIE COUNTY...SO ALLOWED THE WINTER
HIGHLIGHTS TO EXPIRE.
UPDATE ISSUED AT 945 PM MDT SAT APR 18 2015
THE BAND OF MODERATE TO LOCALLY HEAVY SNOW CONTINUES TO SLOWLY
SHIFT EAST THIS EVENING...BUT PERHAPS SLIGHTLY SLOWER THAN
PREVIOUS THINKING. EARLIER ANALYSIS SUGGESTED A FEW STRONGER SNOW
SHOWERS WERE PERSISTING FROM THE NORTHERN LARAMIE RANGE SOUTHWEST
THROUGH THE ARLINGTON AREA AND ON UP INTO THE SNOWY RANGE AND
SOUTHERNMOST AREAS OF THE SIERRA MADRE MOUNTAINS. SHORT TERM
MODELS ALSO SUGGESTED THAT THE BAND WOULD MOVE SLOW TO THE EAST
THIS EVENING... SO FELT IT PRUDENT TO EXTEND THE WINTER STORM
WARNING AND ADVISORY FOR A FEW MORE HOURS AS SNOW WOULD CONTINUE
TO IMPACT THESE LOCATIONS. ENDED THE HEADLINES AT 11PM AS IR
IMAGERY IS SHOWING A RAPID WARMING OF CLOUD TOPS...AND MODELS
SUGGEST THE BAND WILL HAVE WEAKENED AND SHIFTED ENOUGH TO THE EAST
TO CANCEL ALL WINTER HEADLINES AT THIS TIME.
ALSO...ADDED AREAS OF FOG TO THE SUMMIT THROUGH MIDNIGHT AS
WEBCAMS SHOWED THE DEVELOPMENT OF FOG EARLIER...AND HRRR KEEPS
THE FOG AROUND THROUGH 11PM-12AM.
.UPDATE ISSUED AT 546 PM MDT SAT APR 18 2015
TORNADO WATCH HAS BEEN CANCELLED. CONDITIONS ARE NO LONGER
FAVORABLE FOR TORNADO DEVELOPMENT IN THE SOUTHERN NEBRASKA
PANHANDLE WITH THE BOUNDARY LAYER STABILIZING. A FEW
THUNDERSTORMS AREA STILL POSSIBLE OVER THE NEXT FEW HOURS INTO
SOUTHEAST WYOMING AND PANHANDLE BUT SEVERE WEATHER IS VERY
UNLIKELY. A ROUGE FUNNEL CLOUD AND SMALL HAIL STILL POSSIBLE FOR
THE NEXT HOUR OR SO.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 440 PM MDT SAT APR 18 2015
LOTS OF WEATHER CONCERNS OVER THE NEXT 12 HOURS. HEAVY SNOW
CONTINUES IN A NARROW BAND...MAINLY ACROSS EASTERN/CENTRAL CARBON
COUNTY...STRETCHING NORTHEAST INTO THE NORTHERN LARAMIE RANGE. ON
EITHER SIDE OF THE HEAVY BAND...MAINLY LOOKING AT LIGHT NON
ACCUMULATING SNOW OR RAIN. THIS WILL CONTINUE TO BE THE CASE UNTIL
LATE THIS EVENING WHEN THE DEFORMATION AXIS BEGINS TO SHIFT EAST
AS THE NORTHWEST FLOW KICKER PUSHES THE UPPER LOW INTO THE PLAINS.
THE BAND WILL SHIFT EAST LATE THIS EVENING INTO THE OVERNIGHT
HOURS BUT IT WILL ALSO WEAKEN SUBSTANTIAL WILL LITTLE IN THE WAY
OF ADDITION MEASURABLE PRECIPITATION AFTER MIDNIGHT ANYWHERE IN
THE FORECAST AREA.
SHOWERS AND THUNDERSTORMS HAVE DEVELOPED OVER THE PLAINS. A
TORNADO WATCH IS IN EFFECT FOR MORRILL AND CHEYENNE COUNTY IN THE
SOUTHERN NEBRASKA PANHANDLE UNTIL 8 PM MDT. BASED ON RADAR TRENDS
AND CURRENT ATMOSPHERIC ENVIRONMENT...ANY TORNADO THREAT IS
RAPIDLY DECREASING. CURRENT SHOWER ACTIVITY WILL RAPIDLY
STABILIZE THE BOUNDARY LAYER. ALSO...LIMITED SHEAR IS ONLY
SUPPORTIVE OFF VERY SHORT LIVED AND WEAK TORNADIC ACTIVITY. WOULD
NOT BE SURPRISED TO SEE A FEW FUNNEL CLOUD REPORTS WITH
DEVELOPING SHOWERS AND THUNDERSTORMS AS THE OVERALL ENVIRONMENT IS
MORE SUPPORTIVE OF FUNNEL CLOUDS BUT THAT TOO WILL QUICKLY WANE
OVER THE NEXT FEW HOURS.
ANOTHER CONCERN FOR TONIGHT IS NORTHERN WINDS WHICH WILL RAMP UP
THIS EVENING INTO THE OVERNIGHT AS A COLD FRONT MOVES ACROSS THE
AREA. COULD SEE A SHORT PERIOD OF NASTY WINTER CONDITIONS...MAINLY
INTO THE SOUTHERN LARAMIE RANGE AND CHEYENNE AS THE SNOW BAND
SHIFTS EAST AND INTERACTS WITH STRONG GUSTY NORTHERN WINDS. NAM
AND GFS BUFKIT SOUNDINGS AROUND MIDNIGHT SHOWING 45 TO 50 KT
WINDS AT CHEYENNE NOT TOO FAR OFF THE SURFACE. VERY WELL COULD SEE
A 3 TO 4 HOUR PERIOD WITH LOW VISIBILITIES DUE TO FALLING SNOW AND
GUSTY WINDS. FORTUNATELY THIS WILL BE SHORT LIVED IF IT THIS
COMBINATIONS DOES INDEED OCCUR. ALSO WINDS SPEEDS WILL APPROACH
WIND ADVISORY LEVELS INTO THE NEBRASKA PANHANDLE LATER TONIGHT
AND INTO SUNDAY AFTERNOON. DID NOT ISSUE ANY WIND HEADLINES GIVEN
WINTER WEATHER AND CONVECTIVE HEADLINES...BUT A WIND ADVISORY MAY
BE NEEDED EVENTUALLY.
QUIETER WEATHER ACROSS THE AREA SUNDAY WITH THE UPPER LOW OUT OF
THE PICTURE. KEPT SOME LOW POPS GOING ACROSS THE WEST DURING THE
DAY SUNDAY...BUT IT IS LOOKING LESS AND LESS LIKELY FOR ANY
MEASURABLE PRECIPITATION FOR MOST OF SUNDAY. MAIN CHANCES WILL BE
WITH NORTHERN STREAM SHORTWAVE AND UPPER LEVEL JET ENERGY WHICH
SHOULD IMPACT THE SNOWY AND SIERRA MADRES SUNDAY NIGHT.
ACCUMULATIONS WILL BE MINIMAL.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 250 PM MDT SAT APR 18 2015
MEDIUM TO LONG RANGE MODELS IN FAIR AGREEMENT THROUGH THE MIDDLE
OF NEXT WEEK...WITH SOME DISAGREEMENT REGARDING THE TRACK AND
EVOLUTION OF A DEVELOPING LOW PRESSURE SYSTEM LIFTING NORTHEAST
ACROSS THE CENTRAL AND SOUTHERN ROCKY MOUNTAINS BY THURSDAY AND
FRIDAY. FOR EARLY NEXT WEEK...ALL MODELS SHOW NORTHWEST FLOW
INITIALLY WITH RELATIVELY DRY CONDITIONS LASTING INTO EARLY
WEDNESDAY. A WEAK SHORTWAVE TROUGH WILL PUSH ACROSS THE REGION
EMBEDDED IN THE NORTHWEST FLOW...BUT OUTSIDE OF SOME MOUNTAIN/HIGH
VALLEY RAIN AND SNOW SHOWERS...DO NOT EXPECT ANYTHING SIGNIFICANT
WITH HIGH TEMPERATURES ABOUT 10 TO 15 DEGREES COOLER THAN SEASONAL
AVERAGES. TEMPERATURES WILL FINALLY MODERATE SOME BY TUES AND
ESPECIALLY INTO WED...BACK INTO THE UPPER 50S TO UPPER 60S TO THE
EAST OF THE LARAMIE RANGE. A SURFACE HIGH WILL BUILD OVER THE
GREAT PLAINS LATE WEDNESDAY AND ON THURSDAY...RESULTING IN WINDS
VEERING INTO THE EAST AND SOUTHEAST. KEPT TSTORMS IN THE FORECAST
FOR THURSDAY WEST OF THE LARAMIE RANGE...BUT KEPT SHOWERS FURTHER
EAST DUE TO A PERSISTENT LLVL STRATUS DECK.
MODELS STRUGGLING WITH A SHORTWAVE DISTURBANCE LIFTING NORTHEAST
OUT OF ARIZONA THURSDAY NIGHT. 12Z GFS ATTEMPTS TO FORM A CLOSED
LOW ACROSS THE NORTH CENTRAL PLAINS OF COLORADO BY EARLY
FRIDAY...WITH PRECIP EXTENDING INTO THE I80 CORRIDOR OF SOUTHEAST
WYOMING AND WESTERN NEBRASKA. THE ECMWF ON THE OTHER HAND IS MUCH
FURTHER SOUTH...MAINLY SHOWING THE FEATURE ACROSS NORTHERN NEW
MEXICO LIFTING NORTHEAST INTO KANSAS BY FRIDAY. KEPT A 20 TO 30
PERCENT CHANCE OF RAIN AND HIGH ELEVATION SNOW FOR FRIDAY AND EARLY
SATURDAY MORNING.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH SUNDAY AFTERNOON)
A BAND OF SNOW AND RAIN WILL REMAIN OVER CONVERSE...CARBON...AND
ALBANY COUNTIES THIS EVENING...AND THEN WILL RAPIDLY PUSH
SOUTHEAST NEAR A COLD FRONT...WHICH WILL PUSH SOUTHWARD TONIGHT. SCATTERED
TSTORMS HAVE DEVELOPED NEAR KSNY AND JUST EAST OF KCYS THIS
AFTERNOON. THESE TSTORMS WILL GRADUALLY MOVE NORTHWEST THIS
AFTERNOON AND THIS EVENING. SMALL HAIL AND BRIEF HEAVY RAINFALL IS
EXPECTED. A MORE STABLE AIRMASS WILL PUSH INTO THE REGION ON
SUNDAY BEHIND A WEAK COLD FRONT...RESULTING IN LOW PRECIPITATION
CHANCES ACROSS MOST OF THE FORECAST AREA. HOWEVER...IT WILL BE
WINDY BEHIND THIS FRONT WITH NORTH WINDS BETWEEN 20 TO 30 KNOTS
EAST OF THE LARAMIE RANGE.
&&
.FIRE WEATHER...
ISSUED AT 250 PM MDT SAT APR 18 2015
SHOWERS AND THUNDERSTORMS WILL END ACROSS ACROSS THE PLAINS
TONIGHT WITH SNOW ENDING OVER HIGHER ELEVATIONS OF WYOMING AS THE
UPPER LEVEL DISTURBANCE SHIFTS EAST INTO THE CENTRAL PLAINS.
WARMING TREND THROUGH MID WEEK BUT GENERALLY ON THE COOLER SIDE
AND DRY. NEXT CHANCE FOR WIDESPREAD PRECIPITATION IS LATE NEXT
WEEK...MAYBE.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...RJM
SHORT TERM...SML
LONG TERM...TJT
AVIATION...TJT
FIRE WEATHER...SML
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1148 PM MDT MON APR 20 2015
.UPDATE...
ISSUED AT 1139 PM MDT MON APR 20 2015
UPDATED TO ADJUST POPS THROUGH 2 AM. AREAS SOUTH OF HIGHWAY
50 CONTINUE TO SEE ISOLATED TO SCATTERED SHOWERS WHICH SHOULD
DISSIPATE OVER THE NEXT COUPLE OF HOURS. NO OTHER UPDATES AT
THIS TIME. MOZLEY
UPDATE ISSUED AT 553 PM MDT MON APR 20 2015
UPDATED TO ADJUST SHOWER CHANCES ACROSS THE PLAINS...GENERALLY
SOUTH OF HIGHWAY 50 FOR THIS EVENING. MOST HIGH-RES MODELS HAVE
AN AREA OF SHOWER ACTIVITY DROPPING ACROSS THE PLAINS AND MADE
ADJUSTMENTS TO ACCOUNT FOR THIS. NO OTHER UPDATES AT THIS TIME.
MOZLEY
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 318 PM MDT MON APR 20 2015
CURRENTLY...
MODEST NW FLOW PREVAILS ALOFT ACROSS THE REGION. ISOLD TO SCTD SHRA
AND -TSRA WERE NOTED OVER THE HIGHER TRRN AND WERE MOVING ONTO THE
PLAINS. MOST UNSTABLE ATMOSPHERE WAS NOTED OVER THE SPANISH PEAKS
REGION PER RADAR AND TOTAL LTG DATA. TEMPS WERE COOL AT 3 PM WITH
TEMPS IN THE U50S/L60S PLAINS AND 50S VALLEYS.
REST OF TODAY AND THIS EVENING....
ISOLD PRECIP ACTIVITY WILL CONTINUE OVER THE HIGHER TRRN WITH SOME
OF THIS ACTIVITY MOVING ONTO THE PLAINS. ANY ACTIVITY OVER THE PLAINS
WILL GENERALLY REMAIN ISOLD...WITH A BIT MORE COVERAGE EXPECTED
ALONG THE CO/NM BORDER. ACTIVITY WILL REMAIN WEAK WITH BIGGEST
CONCERN BEING CG ACTIVITY.
TONIGHT...
ANY PRECIP OVER THE REGION WILL DIE BY LATER THIS EVENING IF NOT
EARLIER. HRRR AND NAM GUIDANCE DO SHOW A TSTORM OR TWO OVER THE
PLAINS EARLY THIS EVENING UNDER THE MODEST NW FLOW. TEMPS WILL COO
INTO THE 30-35F RANGE ACROSS THE PLAINS WITH 20S IN THE VALLEYS.
TUESDAY...
IT WILL BE WARMER TOMORROW WITH HIGHS EXPECTED TO REACH INTO THE
LOWER 70S MOST OF THE PLAINS...AND 60S VALLEYS. I DO EXPECT THAT WE
WILL SEE A PRECIP PATTERN SIMILAR TO TODAY IN THAT SHOWERS AND
STORMS WILL FORM OVER THE MTNS AND MOVE ONTO THE PLAINS. ACTIVITY
WILL BE A LITTLE MORE ROBUST TOMORROW AS WE SHOULD SEE A BIT MORE
INSTABILITY TOMORROW...HOWEVER NO STRONG ACTIVITY IS ANTICIPATED AT
THIS TIME. /HODANISH
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 318 PM MDT MON APR 20 2015
RELATIVELY ACTIVE LONGER TERM IS ANTICIPATED WITH PRIMARY
METEOROLOGICAL ISSUES BEING POPS(INCLUDING THUNDERSTORMS
AND MOUNTAIN SNOWS)...TEMPERATURES AND GUSTY WINDS AT TIMES.
RECENT LONGER TERM COMPUTER SIMULATIONS...FORECAST MODEL
SOUNDINGS...PV ANALYSIS AND ADDITIONAL METEOROLOGICAL PARAMETERS
SUGGEST THAT TRANSITORY UPPER RIDGING TO SOUTHWESTERLY UPPER
FLOW WILL BE IN PLACE OVER THE FORECAST DISTRICT FROM TUESDAY
NIGHT INTO THURSDAY IN ADVANCE OF NEXT UPPER DISTURBANCE
IMPACTING CWFA FROM LATER THURSDAY INTO FRIDAY NIGHT WITH
ANOTHER UPPER DISTURBANCE IMPACTING THE FORECAST DISTRICT
FROM SATURDAY INTO SATURDAY NIGHT.
AT LOWER LEVELS...SURFACE HIGH CENTERED OVER SOUTH DAKOTA AT 06Z
WEDNESDAY SLOWLY SHIFTS INTO THE UPPER MIDWEST BY FRIDAY
NIGHT...WHILE SURFACE LOW DEVELOPS OVER SOUTHEASTERN COLORADO BY
06Z FRIDAY BEFORE SHIFTING INTO OKLAHOMA BY 06Z SATURDAY AS
NORTHERLY SURFACE SURGE PUSHES ACROSS EASTERN SECTIONS FRIDAY
NIGHT.
THE COMBINATION OF THESE METEOROLOGICAL PARAMETERS IN
COMBINATION WITH ADEQUATE ATMOSPHERIC MOISTURE WILL ALLOW FOR
UNSETTLED CONDITIONS AT TIMES OVER THE CWFA DURING THE
MAJORITY OF THE LONGER TERM IN COMBINATION WITH TEMPERATURES
RUNNING WITHIN A CATEGORY OR SO OF MID TO LATE APRIL
CLIMATOLOGICAL AVERAGES MOST LOCATIONS...ALTHOUGH SOME
ADDITIONAL WARMING IS PROJECTED TO DEVELOP BY EARLY NEXT WEEK.
AT THIS TIME...IT APPEARS THAT THE HIGHEST POTENTIAL OF STRONGER
CONVECTIVE POTENTIAL DURING THE LONGER TERM MAY BE REALIZED
WEDNESDAY AND THURSDAY(ESPECIALLY EASTERN SECTIONS) AS DEEPER
ATMOSPHERIC MOISTURE INTERACTS WITH UPPER IMPULSES TO PRODUCE
LOCALIZED POTENTIAL CAPES/LIS AND BULK SHEARS VALUES OF -5C/1000+
J/KG AND 40 KNOTS RESPECTIVELY BOTH DAYS. AS ALWAYS...WFO PUEBLO
WILL MONITOR CLOSELY.
IN ADDITION...HIGHER ELEVATION ACCUMULATING SNOW IS ANTICIPATED
AT TIMES WITH GUSTY GRADIENT WINDS ALSO POSSIBLE...PRIMARILY FROM
FRIDAY INTO FRIDAY NIGHT. FINALLY...AS BRIEFLY TOUCHED UPON
EARLIER...WARMEST CONDITIONS DURING THE LONGER TERM SHOULD BE
NOTED BY NEXT MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1112 PM MDT MON APR 20 2015
VFR CONDITIONS EXPECTED AT THE TAF SITES OVER THE NEXT 24 HOURS.
LIGHT WINDS TONIGHT WILL INCREASE OUT OF THE SOUTH TO SOUTHWEST
ON TUESDAY...WITH SPEEDS UNDER 15 KTS. SHOWERS AND ISOLATED
THUNDERSTORMS WILL DEVELOP OVER THE MOUNTAINS TUESDAY
AFTERNOON...A FEW OF WHICH WILL MOVE OFF INTO THE ADJACENT TERRAIN
POTENTIALLY IMPACTING KCOS AND KALS. ALTHOUGH ODDS LOOK FAIRLY
LOW THAT THE TERMINALS WILL BE IMPACTED...PATTERN LOOKS SIMILAR TO
WHAT OCCURRED ON MONDAY...SO WILL CARRY VCSH IN THE TAFS AFTER
20Z FOR BOTH LOCATIONS. KPUB IS LESS LIKELY BE IMPACTED BY ANY
PASSING SHOWERS. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...MOZLEY
AVIATION...KT
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1117 PM MDT MON APR 20 2015
.UPDATE...
ISSUED AT 553 PM MDT MON APR 20 2015
UPDATED TO ADJUST SHOWER CHANCES ACROSS THE PLAINS...GENERALLY
SOUTH OF HIGHWAY 50 FOR THIS EVENING. MOST HIGH-RES MODELS HAVE
AN AREA OF SHOWER ACTIVITY DROPPING ACROSS THE PLAINS AND MADE
ADJUSTMENTS TO ACCOUNT FOR THIS. NO OTHER UPDATES AT THIS TIME.
MOZLEY
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 318 PM MDT MON APR 20 2015
CURRENTLY...
MODEST NW FLOW PREVAILS ALOFT ACROSS THE REGION. ISOLD TO SCTD SHRA
AND -TSRA WERE NOTED OVER THE HIGHER TRRN AND WERE MOVING ONTO THE
PLAINS. MOST UNSTABLE ATMOSPHERE WAS NOTED OVER THE SPANISH PEAKS
REGION PER RADAR AND TOTAL LTG DATA. TEMPS WERE COOL AT 3 PM WITH
TEMPS IN THE U50S/L60S PLAINS AND 50S VALLEYS.
REST OF TODAY AND THIS EVENING....
ISOLD PRECIP ACTIVITY WILL CONTINUE OVER THE HIGHER TRRN WITH SOME
OF THIS ACTIVITY MOVING ONTO THE PLAINS. ANY ACTIVITY OVER THE PLAINS
WILL GENERALLY REMAIN ISOLD...WITH A BIT MORE COVERAGE EXPECTED
ALONG THE CO/NM BORDER. ACTIVITY WILL REMAIN WEAK WITH BIGGEST
CONCERN BEING CG ACTIVITY.
TONIGHT...
ANY PRECIP OVER THE REGION WILL DIE BY LATER THIS EVENING IF NOT
EARLIER. HRRR AND NAM GUIDANCE DO SHOW A TSTORM OR TWO OVER THE
PLAINS EARLY THIS EVENING UNDER THE MODEST NW FLOW. TEMPS WILL COO
INTO THE 30-35F RANGE ACROSS THE PLAINS WITH 20S IN THE VALLEYS.
TUESDAY...
IT WILL BE WARMER TOMORROW WITH HIGHS EXPECTED TO REACH INTO THE
LOWER 70S MOST OF THE PLAINS...AND 60S VALLEYS. I DO EXPECT THAT WE
WILL SEE A PRECIP PATTERN SIMILAR TO TODAY IN THAT SHOWERS AND
STORMS WILL FORM OVER THE MTNS AND MOVE ONTO THE PLAINS. ACTIVITY
WILL BE A LITTLE MORE ROBUST TOMORROW AS WE SHOULD SEE A BIT MORE
INSTABILITY TOMORROW...HOWEVER NO STRONG ACTIVITY IS ANTICIPATED AT
THIS TIME. /HODANISH
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 318 PM MDT MON APR 20 2015
RELATIVELY ACTIVE LONGER TERM IS ANTICIPATED WITH PRIMARY
METEOROLOGICAL ISSUES BEING POPS(INCLUDING THUNDERSTORMS
AND MOUNTAIN SNOWS)...TEMPERATURES AND GUSTY WINDS AT TIMES.
RECENT LONGER TERM COMPUTER SIMULATIONS...FORECAST MODEL
SOUNDINGS...PV ANALYSIS AND ADDITIONAL METEOROLOGICAL PARAMETERS
SUGGEST THAT TRANSITORY UPPER RIDGING TO SOUTHWESTERLY UPPER
FLOW WILL BE IN PLACE OVER THE FORECAST DISTRICT FROM TUESDAY
NIGHT INTO THURSDAY IN ADVANCE OF NEXT UPPER DISTURBANCE
IMPACTING CWFA FROM LATER THURSDAY INTO FRIDAY NIGHT WITH
ANOTHER UPPER DISTURBANCE IMPACTING THE FORECAST DISTRICT
FROM SATURDAY INTO SATURDAY NIGHT.
AT LOWER LEVELS...SURFACE HIGH CENTERED OVER SOUTH DAKOTA AT 06Z
WEDNESDAY SLOWLY SHIFTS INTO THE UPPER MIDWEST BY FRIDAY
NIGHT...WHILE SURFACE LOW DEVELOPS OVER SOUTHEASTERN COLORADO BY
06Z FRIDAY BEFORE SHIFTING INTO OKLAHOMA BY 06Z SATURDAY AS
NORTHERLY SURFACE SURGE PUSHES ACROSS EASTERN SECTIONS FRIDAY
NIGHT.
THE COMBINATION OF THESE METEOROLOGICAL PARAMETERS IN
COMBINATION WITH ADEQUATE ATMOSPHERIC MOISTURE WILL ALLOW FOR
UNSETTLED CONDITIONS AT TIMES OVER THE CWFA DURING THE
MAJORITY OF THE LONGER TERM IN COMBINATION WITH TEMPERATURES
RUNNING WITHIN A CATEGORY OR SO OF MID TO LATE APRIL
CLIMATOLOGICAL AVERAGES MOST LOCATIONS...ALTHOUGH SOME
ADDITIONAL WARMING IS PROJECTED TO DEVELOP BY EARLY NEXT WEEK.
AT THIS TIME...IT APPEARS THAT THE HIGHEST POTENTIAL OF STRONGER
CONVECTIVE POTENTIAL DURING THE LONGER TERM MAY BE REALIZED
WEDNESDAY AND THURSDAY(ESPECIALLY EASTERN SECTIONS) AS DEEPER
ATMOSPHERIC MOISTURE INTERACTS WITH UPPER IMPULSES TO PRODUCE
LOCALIZED POTENTIAL CAPES/LIS AND BULK SHEARS VALUES OF -5C/1000+
J/KG AND 40 KNOTS RESPECTIVELY BOTH DAYS. AS ALWAYS...WFO PUEBLO
WILL MONITOR CLOSELY.
IN ADDITION...HIGHER ELEVATION ACCUMULATING SNOW IS ANTICIPATED
AT TIMES WITH GUSTY GRADIENT WINDS ALSO POSSIBLE...PRIMARILY FROM
FRIDAY INTO FRIDAY NIGHT. FINALLY...AS BRIEFLY TOUCHED UPON
EARLIER...WARMEST CONDITIONS DURING THE LONGER TERM SHOULD BE
NOTED BY NEXT MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1112 PM MDT MON APR 20 2015
VFR CONDITIONS EXPECTED AT THE TAF SITES OVER THE NEXT 24 HOURS.
LIGHT WINDS TONIGHT WILL INCREASE OUT OF THE SOUTH TO SOUTHWEST
ON TUESDAY...WITH SPEEDS UNDER 15 KTS. SHOWERS AND ISOLATED
THUNDERSTORMS WILL DEVELOP OVER THE MOUNTAINS TUESDAY
AFTERNOON...A FEW OF WHICH WILL MOVE OFF INTO THE ADJACENT TERRAIN
POTENTIALLY IMPACTING KCOS AND KALS. ALTHOUGH ODDS LOOK FAIRLY
LOW THAT THE TERMINALS WILL BE IMPACTED...PATTERN LOOKS SIMILAR TO
WHAT OCCURRED ON MONDAY...SO WILL CARRY VCSH IN THE TAFS AFTER
20Z FOR BOTH LOCATIONS. KPUB IS LESS LIKELY BE IMPACTED BY ANY
PASSING SHOWERS. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...MOZLEY
AVIATION...KT
AREA FORECAST DISCUSSION
NWS TAUNTON MA
404 AM EDT TUE APR 21 2015
.SYNOPSIS...
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ALONG WITH MILD
TEMPERATURES THIS MORNING...GIVES WAY TO A DRYING TREND THIS
AFTERNOON. A COLD FRONT WILL BRING SCATTERED SHOWERS...AND PERHAPS
EVEN AN ISOLATED THUNDERSTORM OR TWO...WEDNESDAY AFTERNOON AND
EVENING. UNSEASONABLY COOL WEATHER FOLLOWS THURSDAY THROUGH THIS
WEEKEND WITH JUST A SPOT SHOWER FROM TIME TO TIME.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATEST RUNS OF THE HRRR LOOK TO HAVE A VERY GOOD HANDLE ON THE
FORECAST FOR THE NEXT SEVERAL HOURS THIS MORNING. LOTS OF ELEVATED
CONVECTION ACROSS THE WESTERN HALF OF SOUTHERN NEW ENGLAND ALREADY
THIS MORNING. SO FAR...THE MAIN HAZARDS HAVE BEEN THE LIGHTNING
AND BRIEFLY TORRENTIAL RAINFALL. THESE STORMS WERE MOVING ALONG AT
35-45 MPH...SO AM NOT OVERLY CONCERNED ABOUT SIGNIFICANT
WIDESPREAD FLOODING AT THIS TIME. SOME POOR DRAINAGE AREAS COULD
EXPERIENCE NUISANCE FLOODING FOR A TIME THIS MORNING. WE WILL
CONTINUE TO MONITOR RAINFALL RATES THOUGH.
EXPECTING RAPID CLEARING BEHIND A WARM FRONT LATER THIS MORNING
WITH TEMPERATURES SOARING INTO THE UPPER 60S TO NEAR 70 MOST
LOCATIONS. WESTERLY WINDS WILL ALLOW EVEN THE COASTAL LOCATIONS TO
GET IN ON THE WARM TEMPERATURES...UNLIKE THIS PAST SATURDAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/...
A SHORTWAVE WILL BE APPROACHING FROM THE WEST...BRINGING A CHANCE
FOR SOME SHOWERS TO PORTIONS OF WESTERN MA BY DAYBREAK WEDNESDAY.
WITH A COLD FRONT HAVING ALREADY PASSED THROUGH OUR REGION LATE
THIS AFTERNOON...MODELS DO NOT SHOW MUCH RAINFALL AS INSTABILITY
IS RATHER LIMITED. MUCH OF TONIGHT SHOULD REMAIN DRY ACROSS
SOUTHERN NEW ENGLAND WITH SEASONABLE MINIMUM TEMPERATURES.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
HIGHLIGHTS...
* SCATTERED SHOWERS WED WITH A LOW RISK OF THUNDER/SMALL HAIL
* SEASONABLY MILD TEMPERATURES WED
* UNSEASONABLY COOL THU-SUN WITH A SPOT SHOWER OR TWO AT TIMES
OVERVIEW...
OVERALL THE 12Z GUIDANCE IS IN GOOD AGREEMENT WITHIN THE MEDIUM AND
LONG RANGE. HOWEVER EXACT TIMING AND STRENGTH OF EACH SYSTEM STILL
NEEDS TO BE WORKED OUT. UPPER LEVEL LOW WILL CONTINUE TO DOMINATE
THE REGION THROUGH THE EXTENDED...PINWHEELING BETWEEN THE GREAT
LAKES AND NEW ENGLAND. THIS SYSTEM WILL YIELD TO A MORE SHOWERY AND
COOLER FORECAST FOR THE REST OF THE WEEK AND INTO THE WEEKEND.
DETAILS...
* WEDNESDAY AND WEDNESDAY NIGHT...MODERATE CONFIDENCE.
STRONG SHORTWAVE WILL MOVE THROUGH THE FLOW ON WEDNESDAY DEVELOPING
A SURFACE LOW ACROSS HUDSON RIVER VALLEY AND INTO SOUTHERN NEW
ENGLAND. THIS LOW WILL BRING SCT RAIN SHOWERS AND ISOLATED THUNDER
TO THE AREA BY THE AFTERNOON HOURS. APPEARS WE MAY TRY TO WARM
SECTOR ALLOWING SURFACE TEMPS TO REACH INTO THE LOW TO MID 60S. THIS
WILL STEEPEN THE LAPSE RATES TO AROUND 7-8 C/KM AS 500 MB TEMPS ARE
-24C. MODEL GUIDANCE IS ALSO INDICATING THAT SOME SURFACE CAPE MAY
DEVELOP WHICH WILL HELP IN THUNDERSTORM DEVELOPMENT. IN FACT WE
COULD SEE SMALL HAIL/GRAUPEL AS FREEZING HEIGHTS WILL BE LOW
THANKS TO THE COLD POOL. STILL A LOT OF DETAILS TO WORK OUT BUT
SOMETHING TO WATCH IN THE COMING DAY.
* THURSDAY INTO MONDAY...MODERATE CONFIDENCE.
STRONG CUT OFF LOW WILL CONTINUE TO SPIN OVER THE NORTHEAST DURING
THIS TIME PERIOD. NEW ENGLAND COULD SEE A SEVERAL WAVES DEVELOP AND
PUSH THROUGH THE REGION. HOWEVER MAY SEE A LOT OF DIURNAL CU AND
DIURNAL SHOWERS DEVELOPING RATHER THAN WIDESPREAD RAIN. THESE
SHOWERS WILL BE DIURNALLY DRIVEN AS COLD POOL ALOFT WILL BE OVERHEAD
STEEPENING THE LAPSE RATES. AREAS THAT HAVE THE BEST CHANCE FOR
ANY PRECIP WILL BE NORTH OF THE PIKE...CLOSER TO THE LOW PRESSURE.
LASTLY EXPECT TEMPS TO BE ABOUT 5-10 F BELOW AVERAGE FOR THE WEEK
THANKS TO THE COOLER TEMPS ALOFT VIA THE COLD POOL. IN FACT SOME
AREAS MAY NOT SEE THE 60S FOR THE REST OF THE WEEK AND INTO THE
WEEKEND.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
.SHORT-TERM /THROUGH TUESDAY/...
THROUGH 12Z...LINE OF ELEVATED THUNDERSTORMS MOVES INTO THE
CENTRAL AND EASTERN SECTIONS OF SOUTHERN NEW ENGLAND. BRIEF GUSTY
WINDS AND TORRENTIAL RAINFALL ARE THE BIGGEST THREATS.
TODAY...CONDITIONS IMPROVING TO VFR BY MIDDAY. COLD FRONT MOVES
THROUGH WITH WINDS SHIFTING W/SW THIS AFTERNOON.
TONIGHT...HIGH CONFIDENCE IN MAINLY VFR CONDITIONS DESPITE THE
RISK FOR A SPOT SHOWER OR TWO.
KBOS TAF...HIGH CONFIDENCE IN TRENDS. MODERATE CONFIDENCE IN
TIMING. MORNING PUSH LIKELY TO BE AFFECTED. ALSO LOW RISK OF A
THUNDERSTORM BETWEEN 08Z AND 12Z.
KBDL TAF...HIGH CONFIDENCE IN TRENDS. MODERATE CONFIDENCE IN
TIMING. RISK FOR THUNDERSTORMS HAS LIKELY MOVED EAST OF THE
TERMINAL FOR THE REST OF THIS MORNING.
OUTLOOK...WEDNESDAY THROUGH SATURDAY...
WED...MODERATE CONFIDENCE. A COLD FRONT WILL BRING A ROUND OF
SCATTERED SHOWERS MAINLY WED AFTERNOON/EARLY EVENING. LOW RISK FOR
EVEN A FEW RUMBLES OF THUNDER AND PERHAPS SMALL HAIL/GRAUPEL WITH
THE HEAVIEST SHOWERS.
THU/FRI/SAT...HIGH CONFIDENCE. MAINLY VFR. CONDITIONS COULD LOWER TO
MVFR QUICKLY IN A BRIEF DIURNALLY DRIVEN SHOWER OR TWO.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH TONIGHT/...
WILL LIKELY BE ABLE TO CONVERT THE REST OF THE GALE WARNINGS FOR
THE OUTER SOUTHERN NEW ENGLAND WATERS TO SMALL CRAFT ADVISORIES.
STILL NEED TO WATCH FOR THUNDERSTORMS THIS MORNING...SOME OF WHICH
COULD PRODUCE BRIEF GUSTS UP TO 35 KT. VISIBILITY IMPROVES LATER
TODAY WITH WINDS AND SEAS CONTINUING TO DIMINISH TONIGHT.
VISIBILITIES MAY BE LIMITED AT TIMES.
OUTLOOK...WEDNESDAY THROUGH SATURDAY...
WEDNESDAY...HIGH CONFIDENCE. MODEST WEST TO SOUTHWEST FLOW EXPECTED
AHEAD OF A COLD FRONT...BUT SPEEDS WILL BE NEAR SCA ESP ACROSS THE
NEAR SHORE WATERS. A FEW SHOWERS WED AFTERNOON AND EVENING WITH A
LOW RISK OF AN ISOLATED THUNDERSTORM WITH SMALL HAIL.
THURSDAY THROUGH SATURDAY...HIGH CONFIDENCE. MODEST WESTERLY FLOW
AS A RESULT OF CLOSED LOW PRESSURE ACROSS QUEBEC. ENOUGH COLD
ADVECTION OVER THE WATERS WILL BE PRESENT TO GENERATE PERIODS OF 25
KNOT WIND GUSTS. MARGINAL SCA SEAS EXPECTED ACROSS THE OUTER-WATERS
AT TIMES...BUT WITH GOOD VISIBILITY.
&&
.TIDES/COASTAL FLOODING...
EAST TO SOUTHEAST WINDS WILL INCREASE THROUGH TONIGHT. GUIDANCE
CONTINUES TO TRACK STRONGEST WINDS ACROSS NEW ENGLAND EARLY THIS
EVENING...BEFORE HIGH TIDE OCCURS ALONG THE SOUTH COAST /AROUND
03Z/ AND EAST COAST /ABOUT 06Z/. THIS RESULTS IN WINDS BEGINNING
TO SLACKEN AS HIGH TIDE APPROACHES. ALSO SYSTEM IS FAIRLY
PROGRESSIVE SO DURATION OF ONSHORE WINDS IS LIMITED.
ESTOFS CONTINUES TO BE MORE ROBUST AND REALISTIC THAN ETSS WITH
SURGE VALUES 1.0-1.5 FT AT THE TIME OF HIGH TIDE. SEAS ALSO BUILDING
TO 10-15 FT JUST OFFSHORE. THIS SHOULD BE SUFFICIENT TO GENERATE
AREAS OF MINOR COASTAL FLOODING AND SPLASH OVER. THUS WILL CONTINUE
WITH A COASTAL FLOOD ADVISORY FOR THESE LOCATIONS DURING THIS
EVENING AND EARLY TUE MORNING HIGH TIDES.
WINDS DO NOT LOOK STRONG ENOUGH AT THE TIME OF HIGH TIDE FOR A
MODERATE COASTAL FLOOD EVENT.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT WEDNESDAY FOR ANZ235-237-
250-254>256.
SMALL CRAFT ADVISORY UNTIL NOON EDT WEDNESDAY FOR ANZ251.
&&
$$
SYNOPSIS...BELK/DUNTEN
NEAR TERM...BELK
SHORT TERM...BELK
LONG TERM...DUNTEN
AVIATION...BELK/DUNTEN
MARINE...BELK/DUNTEN
TIDES/COASTAL FLOODING...STAFF
AREA FORECAST DISCUSSION
NWS TAUNTON MA
321 AM EDT TUE APR 21 2015
.SYNOPSIS...
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ALONG WITH MILD
TEMPERATURES THIS MORNING...GIVES WAY TO A DRYING TREND THIS
AFTERNOON. A COLD FRONT WILL BRING SCATTERED SHOWERS...AND PERHAPS
EVEN AN ISOLATED THUNDERSTORM OR TWO...WEDNESDAY AFTERNOON AND
EVENING. UNSEASONABLY COOL WEATHER FOLLOWS THURSDAY THROUGH THIS
WEEKEND WITH JUST A SPOT SHOWER FROM TIME TO TIME.
&&
.NEAR TERM /THROUGH TODAY/...
LATEST RUNS OF THE HRRR LOOK TO HAVE A VERY GOOD HANDLE ON THE
FORECAST FOR THE NEXT SEVERAL HOURS THIS MORNING. LOTS OF ELEVATED
CONVECTION ACROSS THE WESTERN HALF OF SOUTHERN NEW ENGLAND ALREADY
THIS MORNING. SO FAR...THE MAIN HAZARDS HAVE BEEN THE LIGHTNING
AND BRIEFLY TORRENTIAL RAINFALL. THESE STORMS WERE MOVING ALONG AT
35-45 MPH...SO AM NOT OVERLY CONCERNED ABOUT SIGNIFICANT
WIDESPREAD FLOODING AT THIS TIME. SOME POOR DRAINAGE AREAS COULD
EXPERIENCE NUISANCE FLOODING FOR A TIME THIS MORNING. WE WILL
CONTINUE TO MONITOR RAINFALL RATES THOUGH.
EXPECTING RAPID CLEARING BEHIND A WARM FRONT LATER THIS MORNING
WITH TEMPERATURES SOARING INTO THE UPPER 60S TO NEAR 70 MOST
LOCATIONS. WESTERLY WINDS WILL ALLOW EVEN THE COASTAL LOCATIONS TO
GET IN ON THE WARM TEMPERATURES...UNLIKE THIS PAST SATURDAY.
&&
.SHORT TERM /TONIGHT/...
A SHORTWAVE WILL BE APPROACHING FROM THE WEST...BRINGING A CHANCE
FOR SOME SHOWERS TO PORTIONS OF WESTERN MA BY DAYBREAK WEDNESDAY.
WITH A COLD FRONT HAVING ALREADY PASSED THROUGH OUR REGION LATE
THIS AFTERNOON...MODELS DO NOT SHOW MUCH RAINFALL AS INSTABILITY
IS RATHER LIMITED. MUCH OF TONIGHT SHOULD REMAIN DRY ACROSS
SOUTHERN NEW ENGLAND WITH SEASONABLE MINIMUM TEMPERATURES.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
HIGHLIGHTS...
* SCATTERED SHOWERS WED WITH A LOW RISK OF THUNDER/SMALL HAIL
* SEASONABLY MILD TEMPERATURES WED
* UNSEASONABLY COOL THU-SUN WITH A SPOT SHOWER OR TWO AT TIMES
DETAILS...
WEDNESDAY AND WEDNESDAY NIGHT...
A FAIRLY STRONG SHORTWAVE AND ASSOCIATED COLD FRONT WILL CROSS THE
REGION WED AFTERNOON AND EVENING. HIGH TEMPS SHOULD STILL REACH
INTO INTO THE UPPER 50S TO MIDDLE 60S AHEAD OF THE FRONT. WE WILL
SEE SCATTERED SHOWERS WITH THE FRONT GIVEN DECENT FORCING AND SOME
MARGINAL INSTABILITY. MOST LIKELY TIME FRAME IS WED AFTERNOON AND
EARLY EVENING. ITS QUITE COLD ALOFT AND MID LEVEL LAPSE RATES ARE
VERY IMPRESSIVE AROUND 8C/KM! IF WE CAN MUSTER A FEW HUNDRED J/KG
OF CAPE...MAY EVEN SEE AN EMBEDDED THUNDERSTORM OR TWO. CONFIDENCE
ON THUNDER IS LOW AT THIS POINT...BUT GIVEN COLD POOL ALOFT THERE IS
AT LEAST THIS RISK FOR SOME GRAUPEL/SMALL HAIL AND PERHAPS EVEN
GUSTY WINDS IN THE HEAVIEST SHOWERS. THIS ACTIVITY SHOULD WIND DOWN
BY WED EVENING.
THURSDAY THROUGH MONDAY...
ANOMALOUS CLOSED UPPER LEVEL LOW SETS UP ACROSS NORTHERN NEW ENGLAND
AND INTO QUEBEC. THE RESULT WILL BE BELOW NORMAL HEIGHTS AND COOLER
THAN NORMAL TEMPS IN SOUTHERN NEW ENGLAND. OVERALL...HIGH TEMPS
WILL RANGE FROM THE UPPER 40S TO MIDDLE 50S MUCH OF THE TIME BUT
SOME MODERATION IS POSSIBLE BY MONDAY. AS FOR PRECIP CHANCES...THE
VAST MAJORITY OF THE TIME SHOULD FEATURE DRY WEATHER.
HOWEVER...GIVEN COLD POOL ALOFT A FEW SPOT SHOWERS WILL BE POSSIBLE
AT TIMES...ESPECIALLY IN NORTHERN SECTIONS DURING THE AFTERNOON
HOURS. LOW RISK FOR EVEN A FEW WET SNOW FLAKES TO MIX IN FOR
A TIME ACROSS THE HIGHER TERRAIN...BUT WOULD BE OF NO IMPACT.
THERE IS ONE FLY IN THE OINTMENT. WE WILL HAVE TO WATCH A MORE
SIGNIFICANT LOW PRESSURE SYSTEM SAT NIGHT/SUN. MOST OF THE MODEL
GUIDANCE KEEPS THAT SYSTEM WELL TO OUR SOUTH. THE 12Z ECMWF IS A
BIT CLOSER THEN THE REST OF THE GUIDANCE...BUT EVEN THAT WOULD KEEP
US DRY. AGAIN...ODDS STRONGLY FAVOR KEEPING THIS SYSTEM SOUTH OR
OUR REGION GIVEN ANOMALOUS CLOSED LOW SITTING JUST TO OUR NORTH.
&&
.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
.SHORT-TERM /THROUGH TUESDAY/...
THROUGH 12Z...LINE OF ELEVATED THUNDERSTORMS MOVES INTO THE
CENTRAL AND EASTERN SECTIONS OF SOUTHERN NEW ENGLAND. BRIEF GUSTY
WINDS AND TORRENTIAL RAINFALL ARE THE BIGGEST THREATS.
TODAY...CONDITIONS IMPROVING TO VFR BY MIDDAY. COLD FRONT MOVES
THROUGH WITH WINDS SHIFTING W/SW THIS AFTERNOON.
TONIGHT...HIGH CONFIDENCE IN MAINLY VFR CONDITIONS DESPITE THE
RISK FOR A SPOT SHOWER OR TWO.
KBOS TAF...HIGH CONFIDENCE IN TRENDS. MODERATE CONFIDENCE IN
TIMING. MORNING PUSH LIKELY TO BE AFFECTED. ALSO LOW RISK OF A
THUNDERSTORM BETWEEN 08Z AND 12Z.
KBDL TAF...HIGH CONFIDENCE IN TRENDS. MODERATE CONFIDENCE IN
TIMING. RISK FOR THUNDERSTORMS HAS LIKELY MOVED EAST OF THE
TERMINAL FOR THE REST OF THIS MORNING.
OUTLOOK...WEDNESDAY THROUGH SATURDAY...
WED...MODERATE CONFIDENCE. A COLD FRONT WILL BRING A ROUND OF
SCATTERED SHOWERS MAINLY WED AFTERNOON/EARLY EVENING. LOW RISK FOR
EVEN A FEW RUMBLES OF THUNDER AND PERHAPS SMALL HAIL/GRAUPEL WITH
THE HEAVIEST SHOWERS.
THU/FRI/SAT...HIGH CONFIDENCE. MAINLY VFR DESPITE THE RISK FOR A
BRIEF DIURNALLY DRIVEN SHOWER OR TWO.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH TONIGHT/...
WILL LIKELY BE ABLE TO CONVERT THE REST OF THE GALE WARNINGS FOR
THE OUTER SOUTHERN NEW ENGLAND WATERS TO SMALL CRAFT ADVISORIES.
STILL NEED TO WATCH FOR THUNDERSTORMS THIS MORNING...SOME OF WHICH
COULD PRODUCE BRIEF GUSTS UP TO 35 KT. VISIBILITY IMPROVES LATER
TODAY WITH WINDS AND SEAS CONTINUING TO DIMINISH TONIGHT.
VISIBILITIES MAY BE LIMITED AT TIMES.
OUTLOOK...WEDNESDAY THROUGH SATURDAY...
WEDNESDAY...HIGH CONFIDENCE. MODEST WEST TO SOUTHWEST FLOW
EXPECTED AHEAD OF A COLD FRONT...BUT SPEEDS SHOULD REMAIN BELOW
SMALL CRAFT THRESHOLDS. A FEW SHOWERS WED AFTERNOON AND EVENING
WITH A LOW RISK OF AN ISOLATED THUNDERSTORM WITH SMALL HAIL.
THURSDAY THROUGH SATURDAY...HIGH CONFIDENCE. MODEST WESTERLY FLOW AS
A RESULT OF CLOSED LOW PRESSURE ACROSS QUEBEC. ENOUGH COLD
ADVECTION OVER THE WATERS WILL BE PRESENT TO GENERATE PERIODS OF 25
KNOT WIND GUSTS. MARGINAL SCA SEAS EXPECTED ACROSS THE OUTER-WATERS
AT TIMES...BUT WITH GOOD VISIBILITY.
&&
.TIDES/COASTAL FLOODING...
EAST TO SOUTHEAST WINDS WILL INCREASE THROUGH TONIGHT. GUIDANCE
CONTINUES TO TRACK STRONGEST WINDS ACROSS NEW ENGLAND EARLY THIS
EVENING...BEFORE HIGH TIDE OCCURS ALONG THE SOUTH COAST /AROUND
03Z/ AND EAST COAST /ABOUT 06Z/. THIS RESULTS IN WINDS BEGINNING
TO SLACKEN AS HIGH TIDE APPROACHES. ALSO SYSTEM IS FAIRLY
PROGRESSIVE SO DURATION OF ONSHORE WINDS IS LIMITED.
ESTOFS CONTINUES TO BE MORE ROBUST AND REALISTIC THAN ETSS WITH
SURGE VALUES 1.0-1.5 FT AT THE TIME OF HIGH TIDE. SEAS ALSO BUILDING
TO 10-15 FT JUST OFFSHORE. THIS SHOULD BE SUFFICIENT TO GENERATE
AREAS OF MINOR COASTAL FLOODING AND SPLASH OVER. THUS WILL CONTINUE
WITH A COASTAL FLOOD ADVISORY FOR THESE LOCATIONS DURING THIS
EVENING AND EARLY TUE MORNING HIGH TIDES.
WINDS DO NOT LOOK STRONG ENOUGH AT THE TIME OF HIGH TIDE FOR A
MODERATE COASTAL FLOOD EVENT.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...COASTAL FLOOD ADVISORY UNTIL 4 AM EDT EARLY THIS MORNING FOR
MAZ007-015-016-019-022-024.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EDT EARLY THIS MORNING FOR
ANZ231>234.
SMALL CRAFT ADVISORY UNTIL 4 AM EDT EARLY THIS MORNING FOR
ANZ230-236.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ235-237-
251.
GALE WARNING UNTIL 4 AM EDT EARLY THIS MORNING FOR ANZ250-
254>256.
&&
$$
SYNOPSIS...BELK/FRANK
NEAR TERM...BELK
SHORT TERM...BELK
LONG TERM...FRANK
AVIATION...BELK/FRANK
MARINE...BELK/FRANK
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS ALBANY NY
1252 AM EDT TUE APR 21 2015
.SYNOPSIS...
.A LOW PRESSURE SYSTEM APPROACHING FROM THE WEST WITH ASSOCIATED
FRONTS WILL BRING OCCASIONAL SHOWERS TO THE AREA ALONG WITH A FEW
RUMBLES OF THUNDER TONIGHT. WITH A LARGE STATIONARY LOW OVER THE
REGION...UNSETTLED WEATHER WILL CONTINUE THROUGH THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1245 AM EDT...A LINE OF SHOWERS AND EMBEDDED THUNDERSTORMS
HAS NOW ENTERED WESTERN PORTIONS OF THE FORECAST AREA...EXTENDING
FROM THE WESTERN ADIRONDACKS SOUTH INTO THE WESTERN MOHAWK
VALLEY...SCHOHARIE VALLEY...AND INTO THE EASTERN CATSKILLS.
ADDITIONAL SHOWERS AND THUNDERSTORMS HAVE FORMED AHEAD OF THIS
LINE ACROSS THE MID HUDSON VALLEY AND SE CATSKILLS...AND ARE
TRANSLATING NORTH/NORTHEAST. WE EXPECT SHOWERS AND THUNDERSTORMS
TO CONTINUE EXPANDING EAST/NORTHEAST OVER THE NEXT 2-4 HOURS. SOME
THUNDERSTORMS COULD CONTAIN LOCALLY HVY DOWNPOURS...AND ISOLATED
GUSTY WINDS. IN ADDITION...SOME SMALL HAIL IS POSSIBLE WITHIN THE
TALLER CONVECTIVE ELEMENTS...AS WE HAD ONE SPOTTER FROM HIGHLAND
NY IN ULSTER CO REPORT PEA SIZE HAIL WITH ONE CELL.
THIS AREA OF SHOWERS AND THUNDERSTORMS APPEARS TO BE IN
ASSOCIATION WITH THE APPROACH OF AN OCCLUDED FRONT FROM THE
WEST...AND ALSO AIDED BY THE PASSAGE OF AN UPPER LEVEL JET CORE
OFF THE NORTHERN MID ATLANTIC COAST...PLACING OUR REGION WITHIN
ITS LEFT EXIT REGION.
A POTENT VORT LOBE CURRENTLY TRANSLATING EAST/NORTHEAST THROUGH
THE LOWER OH AND TN VALLEYS WILL ROUND THE EAST SIDE OF THE UPPER
LEVEL TROUGH AND APPROACH TOWARD DAYBREAK. THIS SHOULD ALLOW
SHOWERS TO PERSIST THROUGH DAYBREAK...WITH PERHAPS A FEW PERIODS
OF STEADY...MODERATE RAIN AT TIMES.
TEMPS WILL HOLD NEARLY STEADY...OR PERHAPS RISE A BIT IN SOME
AREAS BEFORE FALLING SEVERAL DEGREES AGAIN CLOSER TO
DAYBREAK...WITH MAINLY 40S EXPECTED FOR LOWS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY/...
DURING THE DAY ON TUESDAY WE CAN EXPECT SOME LINGERING SHOWERS
DURING THE DAY WITH SOME BREAKS OF SUN POSSIBLE IN THE AFTERNOON.
THE UPPER LEVEL TROUGH AXIS WILL BE PASSING THROUGH THE AREA WITH
AN ASSOCIATED VORT MAX. HIGH TEMPS ON TUESDAY ARE EXPECTED MAX
TEMPS ARE FORECAST TO REACH THE LOWER/MID 60S IN VALLEY AREAS AND
50S ACROSS HIGHER ELEVATIONS.
FOR TUESDAY NIGHT AND WEDNESDAY...A SECONDARY TROUGH IS EXPECTED
TO MOVE FROM THE MIDWEST THROUGH CENTRAL NEW YORK AND CENTRAL
PENNSYLVANIA BRINGING ANOTHER ROUND OF SHOWERS AND THIS WILL BE
FOLLOWED BY YET ANOTHER TROUGH OF LOW PRESSURE ON WEDNESDAY. THIS
IS ALL OCCURRING AT THE SURFACE WHILE ALOFT AN UPPER LEVEL CLOSED
LOW SITS AND SPINS JUST NORTH OF THE UPPER GREAT LAKES SENDING
PIECES OF ENERGY IN THE FORM OF VORT LOBES ACROSS OUR FA DURING
MUCH OF THE PERIOD. EXPECT LOWS ON TUESDAY NIGHT ARE EXPECTED TO
RANGE FROM THE UPPER 20S NORTHWEST TO AROUND 40 SOUTHEAST. SOME
LIGHT SNOW ACCUMULATIONS GENERALLY UNDER AN INCH ARE POSSIBLE
ACROSS THE WESTERN ADIRONDACKS. HIGHS ON WEDNESDAY ARE EXPECTED TO
RANGE FROM THE UPPER 40S NORTHWEST TO AROUND 690 NORTHWEST.
FOR WEDNESDAY NIGHT AND THURSDAY NOT MUCH IMPROVEMENT IS EXPECTED
AS THE UPPER LEVEL TROUGH AXIS SETTLES ACROSS THE NORTHEAST US
WHILE AT THE SURFACE LOW PRESSURE INTENSIFIES ACROSS THE GULF OF
MAINE WITH YET ANOTHER COLD FRONT EXPECTED TO MOVE INTO THE
EASTERN GREAT LAKES BY THURSDAY. THUS THERE WILL STILL BE
SCATTERED SHOWERS AROUND ALTHOUGH THE PCPN SHOULD BE MAINLY ON THE
LIGHT SIDE. EXPECT LOWS WEDNESDAY NIGHT TO BE IN THE UPPER 20S TO
UPPER 30S WITH ONCE AGAIN A LITTLE LIGHT SNOW POSSIBLE ACROSS THE
WESTERN ADIRONDACKS WITH HIGHS ON THURSDAY IN THE MID 40S TO LOWER
50S.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
BELOW NORMAL TEMPERATURES ALONG WITH SOME INTERVALS OF RAIN AND
EVEN SNOW SHOWERS ARE EXPECTED THROUGH THE WEEKEND.
MODEL GUIDANCE REMAINS IN GOOD AGREEMENT INDICATING A LARGE SCALE UPPER
LOW WILL DOMINATE OUR WEATHER. HOWEVER THERE CONTINUES TO BE SOME
DISAGREEMENT ON ITS EXACT TRACK AND WITH THE TIMING OF INDIVIDUAL SHORT
WAVE ROTATING ABOUT IT. THERE IS CONSENSUS THE CENTER OF THE UPPER
LOW SHOULD REMAIN TO OUR NORTH AS IT MOVES ACROSS EASTERN CANADA KEEPING
OUR THE REGION IN WESTERLY FLOW. HAVE FAVORED GUIDANCE FROM THE WEATHER
PREDICTION CENTER TO MAINTAIN FORECAST CONSISTENCY. THE BETTER CHANCES
FOR SCATTERED SHOWERS WILL BE ACROSS THE HIGHER TERRAIN. RAIN SHOWERS
ARE EXPECTED DURING THE DAY...BUT AT NIGHT IT WILL BE COLD ENOUGH FOR
SNOW SHOWER ESPECIALLY ACROSS THE HIGHER ELEVATIONS.
OVERALL EXPECTING HIGHS IN THE 40S AND 50S WITH LOWS IN THE 20S AND 30S.
NORMALS FOR LATE APRIL...
ALBANY NY: HIGHS IN THE LOWER 60S AND LOWS IN THE LOWER 40S.
GLENS FALLS NY: HIGHS IN THE LOWER 60S AND LOWS IN THE UPPER 30S.
POUGHKEEPSIE NY: HIGHS IN THE MID 60S AND LOWS AROUND 40.
BENNINGTON VT: HIGHS IN THE LOWER 60S AND LOWS IN THE UPPER 30S.
PITTSFIELD MA: HIGHS IN THE UPPER 50S AND LOWS IN THE MID 30S.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
A LOW PRESSURE SYSTEM WILL OCCLUDE AS IT MOVES ACROSS THE REGION
TONIGHT. WE HAVE HAD A BIT OF A LULL IN THE PRECIPITATION THIS
EVENING. HAVE SHOWERS ACTIVITY OCCURRING TO EAST AND CONVECTION TO
OUR WEST IN THE VICINITY OF THE WARM FRONT. THE HRRR SEEMS TO HAVE
A PRETTY GOOD HANDLE ON CONVECTION SO HAVE USED IT AS A GUIDE TO
INCREASE POPS THIS EVENING WITH THE BEST CHANCES AS WE APPROACH
MIDNIGHT AS ANOTHER DISTURBANCE AHEAD THE OCCLUDING FRONTAL
BOUNDARY WILL INCREASE THE THREAT FOR CONVECTION. WE ARE NOT
EXPECTED TO GET INTO THE WARM SECTOR IT GETS PINCHED OFF JUST TO
THE SOUTH OF OUR FORECAST AREA TONIGHT AS THE SYSTEM OCCLUDES.
THE MODELS CONTINUE TO SHOW SOME ELEVATED INSTABILITY WITH
SHOWALTER INDICES BELOW ZERO MOVING ACROSS THE REGION TONIGHT...SO
THERE IS A CHANCE FOR THUNDERSTORMS HOWEVER CONFIDENCE IS TOO LOW
TO INCLUDE IN THE TAFS.
CONDITIONS WILL LOWER WITH WIDESPREAD MVFR-IFR DEVELOPING.
A GRADUAL IMPROVEMENT WILL OCCUR WITH THE PASSAGE OF THE OCCLUDED
FRONT. WITH WIDESPREAD VFR FOR THE AFTERNOON.
HAVE NORTHEAST TO SOUTHEAST FLOW ACROSS AREA. RECENT OBSERVATIONS
SHOWN A DIMINISHING TREND IN WIND GUSTS ACROSS THE BERKSHIRES...
TACONICS AND SOUTHERN VERMONT WHERE THE FLOW HAS BEEN ENHANCED BY
THE TERRAIN. WINDS WILL LIGHTEN AS THE OCCLUDED BOUNDARY MOVES
THOUGH WITH A SHIFT TO SOUTHWEST TO WEST WITH ITS PASSAGE.
WESTERLY WINDS WILL INCREASE TO 10 TO 15 KNOTS AND WILL BE GUSTY
ESPECIALLY AT KALB AND KPSF.
OUTLOOK...
TUE NIGHT-WED: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
WED NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA...SHSN.
THU: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
THU NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
FRI: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
FRI NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
SAT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
&&
.FIRE WEATHER...
THERE ARE NO FIRE WEATHER CONCERNS THIS WEEK AS WE WILL BE UNDER
THE INFLUENCE OF AN UPPER LEVEL TROUGH. A WIDESPREAD SOAKING
RAINFALL WILL OCCUR ACROSS THE AREA THROUGH TONIGHT...WITH
RAINFALL AMTS OF 0.75-1.5 INCHES EXPECTED. THE WEATHER WILL BE
COOL AND UNSETTLED FOR MUCH OF THE WEEK.
&&
.HYDROLOGY...
A WIDESPREAD SOAKING RAINFALL WILL OCCUR ACROSS THROUGH TONIGHT.
EXPECTING WIDESPREAD QPF AMOUNTS OF AROUND AN INCH WITH HIGHER
AMOUNTS UP TO AROUND 1.5 INCHES WHERE THE RAINFALL IS ENHANCED BY
THE STRONG EAST TO SOUTHEAST FLOW...PARTICULARLY ACROSS THE
CENTRAL AND SOUTHEASTERN CATSKILLS...TACONICS...BERKSHIRES INTO
THE LITCHFIELD HILLS AND ACROSS SOUTHERN VERMONT. LOCALIZED HIGHER
AMOUNTS OF 2 TO 3 INCHES WILL BE POSSIBLE.
THERE IS STILL SOME SNOW COVER LEFT IN THE FORECAST AREA. BASED
ON NATIONAL OPERATIONAL HYDROLOGIC REMOTE SENSING CENTER (NOHRSC)
THIS IS ACROSS THE PORTIONS OF THE WESTERN ADIRONDACKS AND ACROSS
THE HIGHER TERRAIN OF THE SOUTHERN GREEN MOUNTAINS.
BASED ON CURRENT FORECASTS...ONLY THE WEST CANADA CREEK AT
HINCKLEY DAM IS EXPECTED TO EXCEED ITS FLOOD STAGE BY TUESDAY
EVENING.
THE REST OF THE WEEK THE FORECAST WILL BE DOMINATED BY A PERSISTENT
UPPER LEVEL TROUGH WHICH WILL RESULT IN COOL TEMPERATURES...BREEZY
CONDITIONS AND OCCASIONAL CHANCES FOR MAINLY LIGHT PRECIPITATION.
FOR DETAILS ON SPECIFIC AREA RIVER AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEB-
SITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...IAA/KL/LFM/11/WASULA
NEAR TERM...IAA/KL/LFM/11/WASULA
SHORT TERM...11
LONG TERM...IAA
AVIATION...IAA/WASULA
FIRE WEATHER...11
HYDROLOGY...IAA/KL/11
AREA FORECAST DISCUSSION
NWS LINCOLN IL
323 AM CDT TUE APR 21 2015
.SHORT TERM...(TODAY)
ISSUED AT 323 AM CDT TUE APR 21 2015
WINDY CONDITIONS WILL ONCE AGAIN DEVELOP ACROSS CENTRAL ILLINOIS
TODAY, THANKS TO A TIGHTENING PRESSURE GRADIENT AND DEEP-LAYER
MIXING. THE STRONGEST WINDS WILL BE FOCUSED ALONG/NORTH OF THE I-74
CORRIDOR, WHERE FORECAST SOUNDINGS SUGGEST SUSTAINED WINDS OF AROUND
30MPH WITH GUSTS UP TO 40MPH AT TIMES. WILL THEREFORE ISSUE A
WIND ADVISORY FOR THIS AREA FROM 11AM TO 7PM. FURTHER SOUTH
ACROSS THE REMAINDER OF THE KILX CWA, WINDS WILL REMAIN BELOW
ADVISORY CRITERIA, MAINLY IN THE 25 TO 30MPH RANGE. SKIES WILL
BE MOSTLY SUNNY THROUGH MUCH OF THE DAY, WITH AN INCREASE IN
CLOUDS NOTED ACROSS THE FAR SOUTH DURING THE AFTERNOON AS A
MID-LEVEL SHORT-WAVE APPROACHES FROM THE WEST. ALL MODELS ARE
DEVELOPING SCATTERED SHOWERS/THUNDER IN ADVANCE OF THIS WAVE, BUT
PRIMARILY KEEP THE ACTIVITY JUST SOUTH OF THE CWA. HIGHER-RES
MODELS SUCH AS THE HRRR ARE SLIGHTLY FURTHER NORTH, SO HAVE OPTED
TO INCLUDE SLIGHT CHANCE POPS FOR SHOWERS SOUTH OF I-70 THIS
AFTERNOON. THANKS TO INCREASED SUNSHINE, HIGH TEMPERATURES WILL
BE A FEW DEGREES WARMER THAN YESTERDAY, WITH READINGS CLIMBING
INTO THE LOWER TO MIDDLE 60S.
&&
.LONG TERM...(TONIGHT THROUGH MONDAY)
ISSUED AT 323 AM CDT TUE APR 21 2015
MAIN CHALLENGES IN THE EXTENDED CONTINUE TO BE FROST POTENTIAL
WEDNESDAY/THURSDAY NIGHTS, AS WELL AS, TIMING OF NEXT PRECIP EVENT
BY THE END OF THE WEEK.
DEEP UPPER LOW CURRENTLY CENTERED OVER THE WESTERN GREAT LAKES WILL
BE THE DOMINANT WEATHER FEATURE ACROSS THE MIDWEST FOR THE NEXT FEW
DAYS, RESULTING IN COOL CONDITIONS THROUGH FRIDAY. AS A PIECE OF
ENERGY ROTATES AROUND THE LOW, A WEAK COLD FRONT WILL DROP THROUGH
ILLINOIS TONIGHT. FORECAST SOUNDINGS ARE INITIALLY QUITE DRY:
HOWEVER, THE LATEST MODELS SHOW QUITE A BIT MORE TOP-DOWN MOISTENING
THAN IN PREVIOUS RUNS. AS A RESULT, THINK SCATTERED LIGHT SHOWERS
WILL ACCOMPANY THE FRONT TONIGHT, WITH PERHAPS A FEW SHOWERS
LINGERING INTO WEDNESDAY MORNING ACROSS THE FAR SE. ONCE THE
FRONT EXITS, CANADIAN HIGH PRESSURE WILL BUILD INTO THE REGION FOR
THE MIDDLE AND END OF THE WEEK. THE RIDGE AXIS IS PROGGED TO BE
JUST WEST OF THE MISSISSIPPI RIVER BY 12Z THURSDAY, SO AM
EXPECTING WINDS TO DIMINISH CONSIDERABLY AS THE PRESSURE GRADIENT
WEAKENS. WITH CLEAR SKIES AND LIGHT WINDS, OVERNIGHT LOWS WILL
DIP INTO THE LOWER TO MIDDLE 30S, LEADING TO FROST DEVELOPMENT
ACROSS MUCH OF THE AREA. IF SKIES REMAIN CLEAR, ANOTHER
POTENTIALLY FROSTY NIGHT WILL OCCUR THURSDAY NIGHT AS WELL.
FURTHER OUT, MODELS ARE HAVING CONSIDERABLE DIFFICULTY PINNING DOWN
THE END OF THE WEEK SYSTEM. SOLUTIONS HAVE BEEN FLIP-FLOPPING FROM
RUN TO RUN, SO OVERALL FORECAST CONFIDENCE BEYOND THURSDAY REMAINS
LOWS. THE 00Z APR 21 GFS HAS MADE A MAJOR SHIFT BACK TO A SOLUTION
IT FEATURED A COUPLE OF DAYS AGO. MEANWHILE, BOTH THE ECMWF AND GEM
SEEM TO BE HEADING IN THE OPPOSITE DIRECTION. GIVEN SO MUCH MODEL
INCONSISTENCY, PREFER TO MAKE VERY FEW CHANGES TO THE EXTENDED.
WITH CANADIAN HIGH PRESSURE INITIALLY IN PLACE ACROSS THE MIDWEST ON
WEDNESDAY/THURSDAY, STILL THINK A SLOWER ARRIVAL OF THE NEXT STORM
SYSTEM MAKES SENSE. AS A RESULT, HAVE KEPT FRIDAY DRY DESPITE WHAT
THE ECMWF AND GEM ARE ADVERTISING. HAVE INTRODUCED POPS FRIDAY
NIGHT INTO SATURDAY AS A SYSTEM OVER THE DESERT SOUTHWEST GETS
KICKED EASTWARD. STILL QUITE A BIT OF UNCERTAINTY CONCERNING HOW
FAR NORTH PRECIP WILL SPREAD, BUT HAVE STUCK WITH PREVIOUS THINKING
OF KEEPING HIGHEST POPS FOCUSED ACROSS THE SOUTHERN HALF OF THE CWA.
THIS IS IN GOOD AGREEMENT WITH THE LATEST GFS, BUT NOT THE ECMWF/GEM
WHICH BOTH FOCUS PRECIP MUCH FURTHER NORTH. ONCE THE SYSTEM EXITS,
A RETURN TO DRY WEATHER IS ANTICIPATED FOR SUNDAY BEFORE ANOTHER
FAST-MOVING NORTHERN-STREAM WAVE POTENTIALLY BRINGS A FEW SHOWERS
BACK INTO THE PICTURE BY MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1158 PM CDT MON APR 20 2015
WINDS UP OVERNIGHT, DRIVEN PARTIALLY BY A PRESSURE GRADIENT STILL
IN PLACE IN THE WAKE OF THE EXITING LOW PRESSURE SYSTEM TO THE
NORTH/NORTHEAST. WINDS REMAIN GUSTY TOMORROW, GUSTING IN EXCESS OF
30-35KTS THROUGH THE AFTERNOON WITH DAYTIME HEATING/MIXING.
DIFFERING MOISTURE PROFILES PUT CU POTENTIAL AT 5KFT IN THE EAST
AND HIGHER IN THE WEST...ALTHOUGH THE CU RULE IS ACTUALLY
MINIMIZED IN A RIDGE THROUGH CENTRAL ILLINOIS. QUICK WAVE THROUGH
THE REGION WILL BRING THREAT OF PRECIP BUT COVERAGE IS LIKELY TO
BE SCATTERED AT THIS POINT AND MOSTLY NORTH AND SOUTH OF THE
AREA...SO VCSH FOR BMI AND PIA IS ALL THAT IS MENTIONED IN THE
TAFS FOR NOW.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 11 AM THIS MORNING TO 7 PM CDT THIS EVENING
FOR ILZ027>031-037-038-043>046.
&&
$$
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...HJS
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
556 AM EDT TUE APR 21 2015
.SYNOPSIS...
ISSUED AT 356 AM EDT TUE APR 21 2015
STRONG WESTERLY WINDS ARE EXPECTED TODAY WITH GUSTS AS HIGH AS 45
MPH. THERE IS ALSO A SLIGHT CHANCE FOR A FEW AFTERNOON RAIN
SHOWERS...MAINLY ALONG AND NORTH OF THE TOLL ROAD. HIGHS TODAY WILL
BE IN THE MID 50S WITH LOWS TONIGHT IN THE MID 30S. COOL AND DRY
CONDITIONS WILL THEN CONTINUE THROUGH THE REST OF THIS WEEK.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 356 AM EDT TUE APR 21 2015
STRONG WINDS WILL BE THE FORECAST MESSAGE OF THE DAY. STILL A
DECENT HEIGHT/PRESSURE GRADIENT IN PLACE BETWEEN LARGELY
BAROTROPIC LOW PRESSURE NEAR JAMES BAY AND ANTICYCLONE ACROSS THE
GULF COAST. HOWEVER...THE REAL KEY FACTOR FOR GUSTY WINDS WILL BE
VERY DEEP BOUNDARY LAYER MIXING. COMBINATION OF DRY AIR ADVECTION
NEAR THE SURFACE...STRONG LATE APRIL SUN...AND VERY COLD
CONDITIONS ALOFT WILL SET THE STAGE FOR MIXING HEIGHTS TO CLIMB TO
AT LEAST 6 KFT WITH SOME MODELS (GFS AND RAP) SUGGESTING BOUNDARY
LAYER DEPTHS WILL APPROACH 9 KFT. WIND SPEEDS AT THOSE LEVELS WILL
BE IN THE 40-50 KT RANGE. NO DOUBT IT WILL BE WINDY BUT THE
QUESTION IS WILL IT REACH ADVISORY CRITERIA (39KTS/45MPH). LACK OF
GOOD ISENTROPIC DESCENT TO FORCE DOWN HIGHER MOMENTUM AIR IS
CONCERNING...AS IS LACK OF ISALLOBARIC COMPONENT. ALWAYS SOME
QUESTION AS TO HOW EFFICIENT TURBULENT MIXING ALONE WILL BE IN
PRODUCING HIGHER GUSTS AT THE SURFACE....ESPECIALLY WHEN MIXING
OVER SUCH A DEEP LAYER...AND NAM (AS WELL AS SOME OTHER HI-RES
MODEL) SOUNDINGS ARE NOT QUITE AS BULLISH. THAT BEING SAID...MOST
MODELS SHOW WIND SPEEDS AROUND 40 KTS AT THE TOP OF THE BOUNDARY
LAYER AND SEVERAL INDICATE MIXING INTO SOME 50 KT WINDS. GIVEN
THIS AND POTENTIAL FOR CONVECTIVE SHOWERS TO ENHANCE DOWNWARD
MOMENTUM TRANSFER (SEE NEXT PARAGRAPH)...FEEL IT IS PRUDENT TO GO
AHEAD AND PULL THE TRIGGER ON A WIND ADVISORY. EVEN IF MORE
IMPRESSIVE GFS AND RAP FORECAST SOUNDINGS/WIND FIELDS DONT
VERIFY...WILL STILL BE CLOSE TO ADVISORY CRITERIA.
500MB TEMPS BELOW -30C WILL SUPPORT A VERY DEEP LAYER OF STEEP LAPSE
RATES DURING THE DAY TODAY. DEGREE OF MOISTURE AVAILABLE IS VERY
MUCH IN QUESTION AND REMAINS A SIGNIFICANT LIMITING FACTOR FOR
PRECIP DEVELOPMENT BUT SHREDS OF VORTICITY ROTATING AROUND LARGE
CLOSED LOW COULD PROVIDE JUST ENOUGH MIDLEVEL CONVERGENCE/SATURATION
TO WARRANT A FEW ISOLATED SPRINKLES/SHOWERS...MAINLY IN OUR NORTHERN
COUNTIES. INHERITED FORECAST OF LOW CHANCE POPS ACROSS THE NORTH
SEEMS REASONABLE. IF ANY SHOWERS DO MANAGE TO DEVELOP...STRONG
NEGATIVE BUOYANCY DUE TO EVAPORATIONAL COOLING WITH "INVERTED V"
SOUNDING COULD HELP MIX DOWN SOME HIGHER GUSTS. COULD ALSO BE SOME
SMALL HAIL GIVEN COLD/DRY AIRMASS BUT VERY MARGINAL CAPE VALUES
SUGGEST ANY SUBSTANTIVE UPDRAFTS WILL BE FEW AND FAR BETWEEN.
SLIGHT CHANCE FOR SOME PRECIP LATE TONIGHT AS A MORE POTENT
SHORTWAVE SWINGS THROUGH THE AREA. MOST MODELS KEEP LOW LEVEL FGEN
RESPONSE JUST TO OUR SOUTH THOUGH AND WILL HOLD WITH A LOW CHANCE
POP. DESPITE VERY COLD AIR ALOFT...TEMPS SHOULD RECOVER INTO THE MID
50S TODAY GIVEN DEEP MIXING. LOWS TONIGHT SHOULD GENERALLY HOLD IN
THE MID 30S WITH STEADY WEST WINDS AND AT LEAST SOME CLOUDS KEEPING
THE THREAT OF FROST LOW.
&&
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 356 AM EDT TUE APR 21 2015
NEG HGT ANOMALIES WILL PERSIST OVR SE CANADA THIS PD IN ASSOCN/W SLW
EWD MEANDER OF DEEP CUTOFF FM THE LAKES THROUGH SE CANADA. THIS
YIELDS A CONTN OF NW FLW ALOFT ACRS THE LAKES/OH VALLEY ALG W/MUCH
BLO NORMAL TEMPS AND DRY WX THIS PD.
HWVR POTENTIAL PITFALL EXISTS IN FRI NIGHT-SAT TIME FRAME W/BOTH
HANDLING/PLACEMENT OF NWWD ORIENTED MID LVL TROUGH AXIS EXTENDING
BACK INTO THE NRN PLAINS AND NEWD EJECTION OF SRN STREAM SW LOCATED
OFF THE SRN CA COAST THIS MORNING. EC ELUCIDATED THIS POSSIBILITY
FIRST LAST NIGHT AND NOW HAS GROWING SPRT FM GEM. THUS FELT IT
PRUDENT TO PLACE SOME CONFIDENCE IN ALLBLEND GUIDANCE FOR THIS
TIME PD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 556 AM EDT TUE APR 21 2015
DEEP MIXING AND TIGHT GRADIENT IN THE WAKE OF LOW PRESSURE OVER
ONTARIO WILL LEAD TO STRONG WESTERLY WINDS TODAY. WIND SPEEDS AT
THE TOP OF THE BOUNDARY LAYER ARE IN THE 40-50 KT RANGE SO EXPECT
GUSTS UP TO AROUND 40 KTS FROM LATE MORNING THROUGH THE AFTERNOON.
DRY AIR AND DEEP MIXING WILL HOWEVER KEEP CEILINGS ABOVE 5 KFT
THROUGH THE PERIOD. SLIGHT CHANCE OF A SPRINKLE/SHOWER AT KSBN
BUT NO IMPACT EXPECTED.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WIND ADVISORY FROM 11 AM EDT /10 AM CDT/ THIS MORNING TO 8 PM
EDT /7 PM CDT/ THIS EVENING FOR INZ003>009-012>018-020-
022>027-032>034.
MI...WIND ADVISORY FROM 11 AM THIS MORNING TO 8 PM EDT THIS EVENING
FOR MIZ077>081.
OH...WIND ADVISORY FROM 11 AM THIS MORNING TO 8 PM EDT THIS EVENING
FOR OHZ001-002-004-005-015-016-024-025.
LM...SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR LMZ046.
SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 4 PM EDT
WEDNESDAY FOR LMZ046.
GALE WARNING FROM 11 AM THIS MORNING TO 8 PM EDT THIS EVENING
FOR LMZ046.
SMALL CRAFT ADVISORY UNTIL 4 PM EDT WEDNESDAY FOR LMZ043.
&&
$$
SYNOPSIS...AGD
SHORT TERM...AGD
LONG TERM...T
AVIATION...AGD
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
356 AM EDT TUE APR 21 2015
.SYNOPSIS...
ISSUED AT 356 AM EDT TUE APR 21 2015
STRONG WESTERLY WINDS ARE EXPECTED TODAY WITH GUSTS AS HIGH AS 45
MPH. THERE IS ALSO A SLIGHT CHANCE FOR A FEW AFTERNOON RAIN
SHOWERS...MAINLY ALONG AND NORTH OF THE TOLL ROAD. HIGHS TODAY WILL
BE IN THE MID 50S WITH LOWS TONIGHT IN THE MID 30S. COOL AND DRY
CONDITIONS WILL THEN CONTINUE THROUGH THE REST OF THIS WEEK.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 356 AM EDT TUE APR 21 2015
STRONG WINDS WILL BE THE FORECAST MESSAGE OF THE DAY. STILL A
DECENT HEIGHT/PRESSURE GRADIENT IN PLACE BETWEEN LARGELY
BAROTROPIC LOW PRESSURE NEAR JAMES BAY AND ANTICYCLONE ACROSS THE
GULF COAST. HOWEVER...THE REAL KEY FACTOR FOR GUSTY WINDS WILL BE
VERY DEEP BOUNDARY LAYER MIXING. COMBINATION OF DRY AIR ADVECTION
NEAR THE SURFACE...STRONG LATE APRIL SUN...AND VERY COLD
CONDITIONS ALOFT WILL SET THE STAGE FOR MIXING HEIGHTS TO CLIMB TO
AT LEAST 6 KFT WITH SOME MODELS (GFS AND RAP) SUGGESTING BOUNDARY
LAYER DEPTHS WILL APPROACH 9 KFT. WIND SPEEDS AT THOSE LEVELS WILL
BE IN THE 40-50 KT RANGE. NO DOUBT IT WILL BE WINDY BUT THE
QUESTION IS WILL IT REACH ADVISORY CRITERIA (39KTS/45MPH). LACK OF
GOOD ISENTROPIC DESCENT TO FORCE DOWN HIGHER MOMENTUM AIR IS
CONCERNING...AS IS LACK OF ISALLOBARIC COMPONENT. ALWAYS SOME
QUESTION AS TO HOW EFFICIENT TURBULENT MIXING ALONE WILL BE IN
PRODUCING HIGHER GUSTS AT THE SURFACE....ESPECIALLY WHEN MIXING
OVER SUCH A DEEP LAYER...AND NAM (AS WELL AS SOME OTHER HI-RES
MODEL) SOUNDINGS ARE NOT QUITE AS BULLISH. THAT BEING SAID...MOST
MODELS SHOW WIND SPEEDS AROUND 40 KTS AT THE TOP OF THE BOUNDARY
LAYER AND SEVERAL INDICATE MIXING INTO SOME 50 KT WINDS. GIVEN
THIS AND POTENTIAL FOR CONVECTIVE SHOWERS TO ENHANCE DOWNWARD
MOMENTUM TRANSFER (SEE NEXT PARAGRAPH)...FEEL IT IS PRUDENT TO GO
AHEAD AND PULL THE TRIGGER ON A WIND ADVISORY. EVEN IF MORE
IMPRESSIVE GFS AND RAP FORECAST SOUNDINGS/WIND FIELDS DONT
VERIFY...WILL STILL BE CLOSE TO ADVISORY CRITERIA.
500MB TEMPS BELOW -30C WILL SUPPORT A VERY DEEP LAYER OF STEEP LAPSE
RATES DURING THE DAY TODAY. DEGREE OF MOISTURE AVAILABLE IS VERY
MUCH IN QUESTION AND REMAINS A SIGNIFICANT LIMITING FACTOR FOR
PRECIP DEVELOPMENT BUT SHREDS OF VORTICITY ROTATING AROUND LARGE
CLOSED LOW COULD PROVIDE JUST ENOUGH MIDLEVEL CONVERGENCE/SATURATION
TO WARRANT A FEW ISOLATED SPRINKLES/SHOWERS...MAINLY IN OUR NORTHERN
COUNTIES. INHERITED FORECAST OF LOW CHANCE POPS ACROSS THE NORTH
SEEMS REASONABLE. IF ANY SHOWERS DO MANAGE TO DEVELOP...STRONG
NEGATIVE BUOYANCY DUE TO EVAPORATIONAL COOLING WITH "INVERTED V"
SOUNDING COULD HELP MIX DOWN SOME HIGHER GUSTS. COULD ALSO BE SOME
SMALL HAIL GIVEN COLD/DRY AIRMASS BUT VERY MARGINAL CAPE VALUES
SUGGEST ANY SUBSTANTIVE UPDRAFTS WILL BE FEW AND FAR BETWEEN.
SLIGHT CHANCE FOR SOME PRECIP LATE TONIGHT AS A MORE POTENT
SHORTWAVE SWINGS THROUGH THE AREA. MOST MODELS KEEP LOW LEVEL FGEN
RESPONSE JUST TO OUR SOUTH THOUGH AND WILL HOLD WITH A LOW CHANCE
POP. DESPITE VERY COLD AIR ALOFT...TEMPS SHOULD RECOVER INTO THE MID
50S TODAY GIVEN DEEP MIXING. LOWS TONIGHT SHOULD GENERALLY HOLD IN
THE MID 30S WITH STEADY WEST WINDS AND AT LEAST SOME CLOUDS KEEPING
THE THREAT OF FROST LOW.
&&
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 356 AM EDT TUE APR 21 2015
NEG HGT ANOMALIES WILL PERSIST OVR SE CANADA THIS PD IN ASSOCN/W SLW
EWD MEANDER OF DEEP CUTOFF FM THE LAKES THROUGH SE CANADA. THIS
YIELDS A CONTN OF NW FLW ALOFT ACRS THE LAKES/OH VALLEY ALG W/MUCH
BLO NORMAL TEMPS AND DRY WX THIS PD.
HWVR POTENTIAL PITFALL EXISTS IN FRI NIGHT-SAT TIME FRAME W/BOTH
HANDLING/PLACEMENT OF NWWD ORIENTED MID LVL TROUGH AXIS EXTENDING
BACK INTO THE NRN PLAINS AND NEWD EJECTION OF SRN STREAM SW LOCATED
OFF THE SRN CA COAST THIS MORNING. EC ELUCIDATED THIS POSSIBILITY
FIRST LAST NIGHT AND NOW HAS GROWING SPRT FM GEM. THUS FELT IT
PRUDENT TO PLACE SOME CONFIDENCE IN ALLBLEND GUIDANCE FOR THIS
TIME PD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 130 AM EDT TUE APR 21 2015
LOW LEVEL DRY AIR ADVECTION IN THE WAKE OF LARGE CYCLONE OVER
ONTARIO WILL ENSURE VFR CONDITIONS THROUGH THE PERIOD. MAIN IMPACT
WILL BE VERY STRONG WESTERLY WINDS DURING THE DAY TODAY AS MIXING
HEIGHTS CLIMB TO AROUND 7 KFT WHERE WIND SPEEDS ARE IN THE 40-45 KT
RANGE. A FEW GUSTS TO AROUND 40 KTS ARE POSSIBLE DURING THE LATE
MORNING AND EARLY AFTERNOON. ISOLATED SHOWERS/SPRINKLES ARE ALSO
POSSIBLE AT TIMES TODAY BUT NO IMPACT ANTICIPATED.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WIND ADVISORY FROM 11 AM EDT /10 AM CDT/ THIS MORNING TO 8 PM
EDT /7 PM CDT/ THIS EVENING FOR INZ003>009-012>018-020-
022>027-032>034.
MI...WIND ADVISORY FROM 11 AM THIS MORNING TO 8 PM EDT THIS EVENING
FOR MIZ077>081.
OH...WIND ADVISORY FROM 11 AM THIS MORNING TO 8 PM EDT THIS EVENING
FOR OHZ001-002-004-005-015-016-024-025.
LM...SMALL CRAFT ADVISORY UNTIL 4 PM EDT WEDNESDAY FOR LMZ043-046.
&&
$$
SYNOPSIS...AGD
SHORT TERM...AGD
LONG TERM...T
AVIATION...AGD
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS TOPEKA KS
353 AM CDT Tue Apr 21 2015
.SHORT TERM...(Today and Tonight)
Issued at 300 AM CDT TUE APR 21 2015
Deep upper low over the Great Lakes was making slow eastward
progress early this morning with likely a few small scale waves
rotating around it through the Northern and Central Plains. Periodic
mid cloud was present over the local area via isentropic upglide
from rather brisk and backed mid level winds. At least minor amounts
of EPV along the moist layer allowing some showers to form aloft,
with weak returns on radar showing some very light precip reaching
to the lower troposphere. HRRR and RAP runs quite similar to some
4km WRF runs with light precip forming over central Kansas in the
next few hours, with latest IR imagery indicating recent cloud
development there. All nearby 0Z soundings measured 850mb dewpoint
depressions around 12C, making measurable amounts hard to imagine in
this activity. A somewhat more unstable airmass develops over the
southeast quarter of Kansas this afternoon with weak surface
convergence. Will maintain small storm chances with still minor
isentropic lift and weak wave potential in place. The stronger wind
fields aloft could lead to some storm organization along with CAPE
around 500 J/kg and dry adiabatic low level lapse rates to produce a
very small threat for severe wind and hail in the mid afternoon to
early evening. Areas outside of storms could also see a few rather
strong wind gusts with mixing depths reaching 7000-10000ft AGL
though some veering remains through the column. The still dry
airmass and gusty winds lead to elevated fire danger in western
locations this afternoon.
Cold front via a stronger wave rotating around the low arrives this
evening and makes quick south progress through the state tonight.
Moisture, though modest, will continue to pool ahead of this front
for some storm chances through much of the night in the southern
zones, with typical diurnal trends allowing severe concerns to
diminish. Models are allowing the boundary layer to decouple fairly
quickly behind the front, but am somewhat skeptical of this given
the baroclinic zone they advertise. If winds can fall quicker than
expected, fairly clear skies could present a frost concern, but even
if they do the window of cold and calm conditions for formation
should be rather limited. Will mention patchy frost in far north
where concern is highest.
.LONG TERM...(Wednesday through Monday)
Issued at 300 AM CDT TUE APR 21 2015
Eastern Kansas remains on the southwest side of an upper surface
high for Wednesday, keeping high temperatures around 60 for most
of the area. Have kept rain chances out of the southern areas with
better chances south. Dry conditions continue Wednesday night into
Thursday, with lows in the upper 30s to near 40 and highs climbing
toward the middle 60s Thursday.
Upper pattern starts to shift Thursday night as shortwave ridge
noses out of the southern plains into our area, ahead of an upper
trof lifting northeast out of the four corners region. Initial
sensible weather impacts should be warmer lows in the 40s near 50
Thursday night with some showers possible after midnight as low
level jet makes a return over the area. Latest EC appears to be
trending toward the GFS solution for this shortwave as it moves
into the plains, taking a faster track and developing the warm
front from the surface low out into eastern or southeast Kansas.
GFS keeps the boundary south of the area and would make for cloudy
cool and rainy conditions area wide for Friday and Saturday night,
and with EC solutions also trending this way, have gone with
forecast as such.
Southern branch of the upper jet takes the shortwave trof east of
the area rather quickly on Saturday, with rain ending sometime
during the morning hours. Cooler high pressure once again noses
into the area behind the departing low and holds temperatures in
the low 60s, followed by overnight lows in the 40s. Highs on
Sunday rise a bit more into the middle 60s, and have kept rain
chances relegated to north and west while surface high continues
over the east. Another front progged to move across the area
Sunday night with northwest flow aloft returning on Monday.
Current forecast is for highs near 70, but this will depend on how
strong the front and wave are as to how much cooler air it does,
or does not, bring southward.
&&
.AVIATION...(For the 06Z TAFs through 06Z Tuesday Night)
Issued at 1123 PM CDT MON APR 20 2015
VFR prevails through period while weak passing systems bring sct
to bkn mid level clouds. Westerly winds gust near 20 kts in the
afternoon while sct thunderstorms that develop should remain
south of the terminals.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...65
LONG TERM...67
AVIATION...Bowen
AREA FORECAST DISCUSSION
NWS GRAY ME
1219 AM EDT TUE APR 21 2015
.SYNOPSIS...
LOW PRESSURE MEANDERING NORTH OF THE GREAT LAKES WILL DRIVE A COLD
FRONT TOWARD THE REGION TONIGHT. THE FRONT WILL SLOWLY CROSS THE
REGION ON TUESDAY. LOW PRESSURE NORTH OF THE GREAT LAKES WILL
GRADUALLY WEAKEN AS IT DRIFTS SOUTHEAST INTO NEW ENGLAND WEDNESDAY
THROUGH THURSDAY. LOW PRESSURE WILL CONTINUE TO WEAKEN AS IT
MEANDERS NORTH OF NEW ENGLAND FRIDAY THROUGH SATURDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
1215 AM...MINOR ESTF UPDATE TO REFLECT CURRENT RADAR TRENDS AND
TO INGEST THE 04Z MESONET INTO 1ST PERIOD GRIDS.
PREV DISC...
UPDATE...THE HIGHEST THREAT FOR STRONG WIND GUSTS IS
COMING TO AN END...SO WILL TAKE DOWN THE WIND ADVISORY. OTHERWISE
NO MAJOR CHANGES TO THE FORECAST. MESOSCALE MODELS STILL FAVOR THE
IDEA OF A COMPLEX OF TSTMS CROSSING THE FORECAST AREA DURING THE
MORNING. SO NO CHANGES THERE EITHER.
HAVE MODIFIED THE GRIDS THRU MORNING BASED ON LATEST HI-RES MODEL
GUIDANCE. EXAMINING RECENT HRRR RUNS HAVE A LARGE AREA FAVORABLE
FOR LIGHTNING DEVELOPMENT MOVING ACROSS THE REGION ON THE LEADING
EDGE OF THE DRY SLOT NEAR MORNING. IN ADDITION...THE SPC SSEO
PRODUCTS ALSO FAVOR A CLUSTER OR LINE OF TSTMS CROSSING THE
FORECAST AREA NEAR 12Z. HAVE INCREASED THE PROBABILITY FOR THUNDER
LATE TONIGHT AND EARLY TUE AS A RESULT.
HAVE ALSO INTRODUCED SOME AREAS OF HEAVY RA TO THE GRIDS NEAR THE
COASTAL FRONT AS WELL AS IN THE EAST SLOPES OF THE MTNS WHERE
STRONG SELY LLJ WILL IMPINGE UPON THE TERRAIN.
THIS LLJ...WHICH IS REALLY JUST GETTING UNDERWAY OVER SRN NEW
ENGLAND PER KBOX 88D...WILL SLOWLY TRAVERSE THE COAST THRU ABOUT
06Z. THIS PUTS HEAVIEST PRECIP IN THE FORECAST AREA BETWEEN ABOUT
00Z AND 06Z. IN ADDITION TO THE HEAVY PRECIP...THIS LLJ MAY INDUCE
SOME STRONG DOWNSLOPE WIND GUSTS NW OF THE WHITE MTNS.
PREVIOUS DISCUSSION...THE FIRST BATCH OF RAIN FROM THIS MORNING
WAS MOVING INTO EASTERN MAINE AS A WARM FRONT LIFTED NORTH INTO
SOUTHERN CANADA. SO FAR ONLY A TENTH TO ABOUT A THIRD OF AN INCH
OF RAIN HAS FALLEN TODAY WITH SOME ISOLATED HIGHER AMOUNTS. THIS
MORNINGS GYX SOUNDING HAD PLENTY OF DRY AIR AND THIS INHIBITED
RAINFALL FROM SPREADING FASTER FOR THE FIRST HALF OF THE DAY.
STEADIER RAINS ARE NOW OVER SOUTHERN NH AND MOVING INTO WESTERN
MAINE. THIS TREND WILL CONTINUE INTO THE EVENING HOURS.
A SECONDARY CYCLONE WILL FORM TONIGHT OVER THE VIRGINIAS AND MOVE
NE ALONG THE ATLANTIC COAST. AS IT DEEPENS IN THE GULF OF MAINE A
LLJ WILL STRENGTHEN AND FEED MOISTURE RICH AIR INTO COASTAL NH AND
MAINE. WARM RAIN PROCESSES AND TRAINING OF CELLS WILL SUPPORT HEAVY
RAIN OVERNIGHT AND INTO TUESDAY. A FLOOD WATCH REMAINS IN EFFECT AS
RAIN COMBINES WITH SNOWMELT TO BRING RIVERS AND STREAMS TO NEAR
BANKFULL.
WINDS WILL BE GUSTY... ESPECIALLY ALONG THE COAST... BUT WE
SHOULD FALL SHORT OF WIND ADVISORY CRITERIA. COASTAL FLOODING WILL
ALSO BE A CONCERN FROM PORTLAND WESTWARD AS EASTERLY FLOW
INCREASES AND COINCIDES WITH THE ASTRONOMICAL HIGH TIDE. MORE
INFORMATION ON THESE HAZARDS BELOW.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 AM WEDNESDAY/...
MODERATE TO HEAVY RAIN CONTINUES INTO TUESDAY MORNING. MUCAPE
VALUES INDICATE A SLIGHT CHANCE FOR THUNDERSTORMS BETWEEN 12-18Z
TOMORROW AS THE COLD CORE OF THE UPPER LOW SWINGS BY OVERHEAD.
DRIER AIR PUNCHES IN FROM THE SW MIDDAY TUESDAY. SOME LINGERING
SHOWERS WILL BE POSSIBLE OVER THE MOUNTAINS IN UPSLOPE FLOW. HIGHS
SHOULD WARM INTO THE UPPER 40S NORTH TO LOWER 60S SOUTH.
ADDITIONAL SHOWERS WILL BE POSSIBLE TUESDAY NIGHT WITH CYCLONIC
FLOW ALOFT.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
BROAD UPPER LEVEL CLOSED LOW WILL KEEP WEATHER UNSETTLED
IN THE NORTHEAST THROUGH THE WEEK AND INTO THE WEEKEND AS
IT GRADUALLY SHIFTS EAST. EXPECT SEVERAL LOBES OF ENERGY
TO ROTATE AROUND THIS SYSTEM AND INTO THE NORTHEAST. ANY
MORNING SUN ON WEDNESDAY WILL QUICKLY GIVE WAY TO CLOUDS
AND SHOWERS AS THE FIRST OF THESE DISTURBANCES SWINGS INTO
THE REGION. EXPECT THESE SHOWERS TO PERSIST INTO WEDNESDAY
NIGHT AS A WEAK SURFACE LOW SLOWLY CROSSES THE REGION.
STEADIER PRECIP WILL COME TO AN END AS LOW PRESSURE LIFTS INTO
THE MARITIMES ON THURSDAY. EXPECT CLOUDY SKIES AND SCATTERED
SHOWERS THURSDAY THROUGH FRIDAY WITH HIGHS IN THE 40S TO LOWER
50S.
SHOWER ACTIVITY WILL DIMINISH OVER THE WEEKEND BUT SKIES WILL
REMAIN MOSTLY CLOUDY WITH RAIN OR SNOW SHOWERS POSSIBLE MAINLY IN
NORTHERN ZONES.
&&
.AVIATION /04Z TUESDAY THROUGH SATURDAY/...
SHORT TERM...MVFR WILL DETERIORATE TO LIFR AND IFR SHORTLY AS
HEAVIER RAIN MOVES IN. RAIN MAY BE LIGHTER AT KHIE WHERE WE WILL
SEE THE RAIN SHADOW EFFECT. ALSO SOME SNOW MAY MIX IN LATE IN THE
NORTH. EAST WINDS MAY GUST TO 35 KTS AT TIMES. SOME IMPROVEMENT BY
MID MORNING TUESDAY AS RAIN MOVES EAST.
LONG TERM...AREAS OF MVFR CEILINGS WEDNESDAY THROUGH FRIDAY.
&&
.MARINE...
SHORT TERM...EASTERLY WINDS AND SEAS CONTINUE TO BUILD TONIGHT. A
GALE WARNING REMAINS IN EFFECT THROUGH 2 PM TUESDAY. WINDS WILL
DECREASE BUT A SCA WILL LIKELY BE NEEDED FOR WAVES THROUGH
WEDNESDAY EVENING.
LONG TERM...SCA`S MAY BE NEEDED THURSDAY AND FRIDAY.
&&
.FIRE WEATHER...
ONSHORE FLOW TODAY BRINGS MORE MOISTURE AND EVENTUALLY RAIN TO
THE AREA. A SOAKING RAIN IS EXPECTED LATE TODAY AND TUESDAY.
&&
.HYDROLOGY...
A WIDESPREAD 1 TO 2 INCHES OF RAIN IS EXPECTED FROM THIS
AFTERNOON THROUGH TUESDAY. HOWEVER...GIVEN STRONG MOISTURE
INFLOW...LOCALIZED AMOUNTS OF UP TO 3 INCHES COULD OCCUR. THIS
WOULD LEAD TO FLOODING PROBLEMS...ESPECIALLY IN AREAS WHERE SNOW
MELT IS STILL OCCURRING. A FLOOD WATCH REMAINS IN EFFECT.
&&
.TIDES/COASTAL FLOODING...
AS EASTERLY WINDS CONTINUE TO INCREASE...SEAS WILL BUILD 10 TO 15
FT. HIGH TIDE ON APRIL 21 IS AT 1:21 AM WITH A PREDICTED HEIGHT OF
11.4 FT MLLW. HOWEVER...ONSHORE WINDS ARE EXPECTED TO RESULT IN A 1-
2 FT STORM SURGE. THE COMBINATION OF WIND, WAVES AND HIGH TIDE WILL
RESULT IN OVERWASH AND POSSIBLE INUNDATION FOR THE BEACHES OF THE
SOUTH COAST OF MAINE AND NEW HAMPSHIRE. FARTHER DOWNEAST THE
EASTERLY WIND DIRECTION IS LESS FAVORABLE FOR ONSHORE INUNDATION.
EVEN SO THE SIGNIFICANT WAVES MAY RESULT IN SOME COASTAL FLOODING
AND A COASTAL FLOOD ADVISORY HAS BEEN POSTED THERE.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...FLOOD WATCH THROUGH WEDNESDAY MORNING FOR MEZ007>009-012>014-
018>028.
COASTAL FLOOD ADVISORY UNTIL 3 AM EDT EARLY THIS MORNING FOR
MEZ025>028.
COASTAL FLOOD WARNING UNTIL 3 AM EDT EARLY THIS MORNING FOR
MEZ023-024.
NH...FLOOD WATCH THROUGH WEDNESDAY MORNING FOR NHZ002>015.
COASTAL FLOOD WARNING UNTIL 3 AM EDT EARLY THIS MORNING FOR
NHZ014.
MARINE...GALE WARNING UNTIL 2 PM EDT THIS AFTERNOON FOR ANZ150>154.
&&
$$
ES
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
122 AM EDT TUE APR 21 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 353 PM EDT MON APR 20 2015
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW DEEPENING UPR TROF
OVER CENTRAL NAMERICA BTWN RDGS ALONG THE E AND W COASTS...WITH 12HR
H5 HGT FALLS UP TO 150M NOTED OVER NRN WI IN ADVANCE OF SHRTWV
LIFTING NWD INTO THE UPR LKS TO THE E OF THE UPR TROF AXIS. IR AND
WV IMAGERY SHOW A WELL DEFINED COMMA HEAD CLD OVER THE UPR GREAT LKS
IN ADVANCE OF SHRTWV AND ON CYC SIDE OF ACCOMPANYING H7 LO TRACK.
STEADY RA UNDER THIS COMMA HEAD HAS MIXED WITH SN OVER THE WRN CWA
WHERE DYNAMIC COOLING AND SOME LLVL CAA HAVE COOLED THE COLUMN
SUFFICIENTLY. FARTHER TO THE E...DRY SLOTTING ON THE ACYC SIDE OF H7
LO TRACK HAS TENDED TO DIMINISH THE PCPN COVERAGE/INTENSITY OVER THE
FAR E. ANOTHER SHRTWV IS DIGGING SWD THRU FAR NW ONTARIO/MANITOBA ON
THE WRN FLANK OF H5 CLOSED LO
MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON POPS/PTYPE ASSOCIATED
WITH SHRTWV MOVING THRU THE UPR LKS RIGHT NOW AND THEN TNGT/TMRW
ACCOMPANYING PASSAGE OF NEXT SHRTWV AND WITHIN LINGERING DEEP CYC
FLOW UNDER CUTOFF H5 LO PROGGED TO LINGER OVER THE UPR LKS.
LATE TDAY/TNGT...AS SHRTWV E OF THE UPR TROF AXIS LIFTS TO THE N
THRU THIS AFTN AND TENDS TO SHEAR OUT...MODELS SHOW AREA OF SHARP
DEEP LYR QVECTOR CNVGC SUPPORTING AXIS OF COLDER CLD TOPS
DIMINISHING AND GIVING WAY TO SOME DEEP LYR QVECTOR DVGC. SO AREA OF
STEADY RA/SN OVER THE W SHOULD DIMINISH BY LATE AFTN WITH ARRIVAL OF
THE NEGATIVE DYNAMICS/MID LVL DRYING. POPS OVER THE E WL TEND TO
INCREASE LATE THIS AFTN/EARLY EVNG AS COMMA TAIL AXIS OF HIER RH
SWINGS E THRU THAT AREA...BUT PCPN INTENSITY WL NOT BE AS GREAT AS
OVER THE W SINCE THE SUPPORTING AXIS OF DIMINISHING DEEP LYR QVECTOR
CNVGC IS FCST TO REMAIN OVER THE W. NOT OUT OF THE QUESTION THERE
COULD BE A FEW INCHES OF WET SN ACCUM OVER THE HIER TERRAIN OF THE
W...BUT THERE SHOULD BE LTL IF ANY SN OVER THE E HALF WITH WEAKER
DYNAMIC FORCING/COOLING. LATER TNGT...THE TRAILING SHRTWV DIGGING
SWD TOWARD NW MN ON THE WRN FLANK OF CLOSED H5 LO IS FCST TO DIG TO
NEAR NW WI BY 12Z TUE...BRINGING SOME DPVA/MORE DEEP LYR QVECTOR
CNVGC TO THE W LATER TNGT. SHARP CYC UPSLOPE WNW FLOW IN THE
PRESENCE OF THE DEEPER FORCING/MSTR WL SUPPORT LIKELY POPS IN THIS
AREA. THERE COULD BE A FEW INCHES OF WET SN ACCUM OVER MAINLY THE
HIER TERRAIN. OVER THE CENTRAL AND E...THERE WL BE ONLY ISOLD-SCT RA
AND SN SHOWERS.
TUE...SHRTWV/ACCOMPANYING SFC LO PRES TROF ROTATING ARND CLOSED H5
LO SHIFTING SLOWLY TO THE E OVER LK SUP IS FCST TO WEAKEN SLOWLY...
LEADING TO SLOWLY DIMINISHING DEEP LYR QVECTOR CNVGC. ALTHOUGH THESE
TRENDS WL RESULT IN DIMINISHING POPS...DAYTIME HEATING/LLVL
DESTABILIZATION WL ENHANCE POPS ESPECIALLY OVER THE ERN CWA IN THE
AFTN...WHERE LLVL CNVGC WITHIN LO PRES TROF WL BE ENHANCED BY LK
BREEZE DEVELOPMENT. OTRW...LINGERING SHARP LLVL CNVGC AND THE
DAYTIME HEATING WL MAINTAIN AT LEAST CHC POPS. THE PCPN SHOULD BE
MAINLY SN IN THE MRNG...BUT THIS PCPN WL MIX WITH/CHG TO RA OVER THE
SE HALF IN THE AFTN WITH DAYTIME HEATING/TEMPS RISING AOA 40.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 338 PM EDT MON APR 20 2015
A LARGE UPPER LOW CENTERED OVER NORTHERN ONTARIO WILL BE
INFLUENCING THE GREAT LAKES REGION THROUGH THE FIRST HALF OF THE
LONG TERM PERIOD. THIS WILL LEAD TO BELOW NORMAL TEMPERATURES AND
PERIODS OF SNOW BEFORE GRADUALLY SHIFTING EAST INTO THE ATLANTIC BY
THE WEEKEND.
AS THAT UPPER LOW SPINS BETWEEN LAKE SUPERIOR AND JAMES BAY...IT
WILL ROTATE SEVERAL SHORTWAVES ACROSS THE UPPER GREAT LAKES REGION
TUESDAY NIGHT THROUGH THURSDAY. THESE WAVES WILL BRING PERIODS OF
SHOWERS TO THE AREA...WITH HELP FROM BOTH LAKE SUPERIOR (850MB
TEMPS FALLING TO -10C TO -12C ON WEDNESDAY MORNING) AND TERRAIN
ENHANCEMENT (PERSISTENT LOW LEVEL NORTHWESTERLY FLOW). WILL CONTINUE
TO FOCUS THE HIGHEST POPS (LIKELY VALUES) IN THOSE AREAS FAVORED BY
ALL THREE FEATURES (HIGHER TERRAIN OF THE WEST/NORTHWEST) AND ALSO
EAST DOWNWIND OF LAKE SUPERIOR...AND INCLUDE CHANCE/SLIGHTS FOR THE
REST OF THE CWA. WITH THE AMOUNT OF COLD AIR IN PLACE...EXPECT THE
PRECIPITATION TO FALL MAINLY AS SNOW. WITH LOW LEVEL TEMPERATURES
WARMING AWAY OVER THE SOUTHERN THIRD OF THE CWA...COULD SEE SOME
RAIN MIXING IN THERE...BUT OTHERWISE SNOW WILL BE THE NORM. COULD
SEE A COUPLE INCHES OF ACCUMULATION IN THE FAVORED LOCATIONS
TUESDAY NIGHT AND UP TO AN INCH WEDNESDAY AND AGAIN WEDNESDAY
NIGHT. WITH DRIER AIR STARTING TO MOVE INTO THE AREA ON
THURSDAY (ASSOCIATED WITH A SURFACE RIDGE MOVING INTO THE
NORTHERN PLAINS...SHOULD SEE THE COVERAGE OF THE SHOWERS
DIMINISHING THROUGH THE DAY THURSDAY AND CONTINUING TO WEAKENING
INTO FRIDAY. ALSO...DON/T EXPECT HIGHS TO RISE MUCH OUT OF THE
LOW-MID 30S ON WED/THURS OVER THE NORTH HALF OF THE CWA...WITH SOME
HIGHS AROUND 40 OVER THE SOUTH CENTRAL. WILL LIKELY BREAK THE
RECORD LOW HIGH TEMPERATURE HERE AT OUR OFFICE ON WEDNESDAY (36 SET
IN 1972).
EXTENDED RANGE MODELS DIFFER ON HOW QUICKLY THE UPPER LOW DEPARTS
THIS WEEKEND...BUT SHOULD STILL SEE ENOUGH INFLUENCE FROM THE
SURFACE RIDGE MOVING INTO THE NORTHERN PLAINS TO KEEP MOST OF THE
AREA DRY. WITH THE NORTHERLY FLOW OFF LAKE SUPERIOR...EXPECT
TEMPERATURES TO REMAIN BELOW NORMAL BUT IN THE 40S TO AROUND 50. AS
THE UPPER LOW RETROGRADES BACK OVER QUEBEC EARLY NEXT WEEK...COULD
SEE THE UPPER GREAT LAKES REGION BEING AFFECTED BY THE WESTERN EDGE
OF THE ENERGY ROTATING AROUND THE UPPER LOW AND LIKELY KEEPING
BELOW NORMAL TEMPERATURES IN PLACE THROUGH THE END OF APRIL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 120 AM EDT TUE APR 21 2015
APPROACH OF ANOTHER DISTURBANCE/LOW PRES TROF OVERNIGHT WILL RESULT
IN DETERIORATING CONDITIONS FROM MVFR TO IFR AT KIWD/KCMX AS -SHSN
INCREASE AGAIN. NOT OUT OF THE QUESTION THAT SOME BRIEF PERIODS OF
LIFR COULD OCCUR. DOWNSLOPE W TO SW WINDS AT KSAW WILL RESTRICT THE
IMPACT THERE...SO MVFR CIGS SHOULD PREVAIL. AFTER THE DISTURBANCE
EXITS TO THE E...EXPECT MVFR CONDITIONS TO RETURN TO KIWD/KCMX MID
TO LATE MORNING. -SHSN WILL CONTINUE AT ALL TERMINALS TODAY...AND
IT`S CERTAINLY POSSIBLE THAT BRIEF IFR VIS COULD OCCUR AT TIMES...
ESPECIALLY AT KIWD/KSAW AS DAYTIME HEATING/INSTABILITY AID -SHSN
INTENSITY. WINDS WILL GENERALLY REMAIN GUSTY...PARTICULARLY AT KCMX
WHERE GUSTS OF 25-30KT SHOULD BE COMMON FOR MUCH OF THE FCST PERIOD.
MVFR CONDITIONS WILL CONTINUE INTO THIS EVENING AT ALL TERMINALS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 353 PM EDT MON APR 20 2015
SHARP PRES GRADIENT ON THE SW FLANK OF SLOW MOVING LO PRES IN
ONTARIO WILL CAUSE W TO NW WINDS UP TO 25-30 KTS INTO THU. ALTHOUGH
THERE COULD BE SOME GALE FORCE GUSTS AT TIMES...WIDESPREAD GALES ARE
NOT EXPECTED. THE CLOSER APPROACH OF HI PRES LATER IN THE WEEK WILL
RESULT IN NW WINDS DIMINISHING TO NO MORE THAN 20 KTS ON FRI AND
SAT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...KC
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
357 AM CDT TUE APR 21 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM CDT TUE APR 21 2015
AN ARCTIC COLD FRONT ACROSS NORTH DAKOTA WILL BACK INTO THE FCST
AREA THIS AFTN PRODUCING SOME CLOUDINESS. THE FRONT WILL CONTINUE
TO MOVE SOUTH AND WEST TONIGHT. BY 12Z WEDNESDAY A SMALL AREA OF
HIGH PRESSURE HAS SETTLED OVER NCNTL NEB WHICH SHOULD PRODUCE
LOWS IN THE 20S. BY THIS TIME...THE MODELS SUGGEST ANY CLOUD
COVER WOULD LIE ACROSS THE PANHANDLE AND SOUTHWEST NEB WHICH
WOULD HOLD UP LOWS IN THE LOWER 30S.
HIGHS TODAY RISE INTO THE 60S AHEAD OF THE FRONT WITH 50S NORTH
OF THE FRONT ALONG HIGHWAY 20.
THE MIDLEVEL CLOUD COVER ACROSS CNTL/SERN NEB EARLY THIS MORNING
IS ASSOCIATED WITH 700MB FRONTOGENESIS. THE RAP MOVES THESE
CLOUDS SOUTHEAST AND THEN DROPS A SECOND BATCH OF CLOUDS INTO NRN
NEB AS EARLY AS 15Z WHICH HANG AROUND MOST OF THE DAY AND THEN
MOVE SOUTH AND WEST TONIGHT. THE RADAR RETURNS ACROSS NORTH
DAKOTA MOVE EAST OF THE FCST AREA IN THE NAM MODEL WHILE THE HRRR
SHOWS TOO MUCH DRY AIR IN THE LOWER LEVELS FOR ANYTHING MORE THAN
SPRINKLES THIS AFTN AND TONIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 355 AM CDT TUE APR 21 2015
SURFACE HIGH PRESSURE QUICKLY FOLLOWS THE COLD FRONT AND WILL
SLIDE SOUTHEAST OF THE AREA EARLY IN THE DAY ON WEDNESDAY WITH
SOUTHERLY WINDS DEVELOPING. DESPITE SOUTHERLY WINDS...COOL AIR
ALOFT...850 TEMP FROM 3C EAST TO 8C WEST...AND EVEN WITH SUN AND
GOOD MIXING...HIGHS IN THE UPPER 50S AND LOWER 60S. MEANWHILE AN
UPPER LEVEL LOW LIFTS TOWARDS THE DESERT SW. MODELS ALSO SHOW A
WEAK SYSTEM AHEAD OF THE MAIN LOW...PUSHING ACROSS THE SOUTHERN
PLAINS.
A SECOND WAVE EJECTS FROM THE MAIN LOW AND ARRIVES TO THE
SOUTHERN/CENTRAL PLAINS WED NIGHT INTO THURSDAY. MARGINAL LIFT
INTO SW NEB MAY RESULT IN A FEW LIGHT SHOWERS INITIALLY. A BETTER
CHANCE ARRIVES LATER IN THE DAY ON THURSDAY AFTER WE GET SOME
HEATING. MODELS INCREASE CAPES TO A FEW 100 J/KG AND LIFTED INDEX
VALUES AROUND ZERO OR SLIGHTLY NEG. GENERALLY THING ACTIVITY WILL
BE SOME SHOWERS AND A FEW RUMBLES OF THUNDER HERE OR THERE.
BY FRIDAY THE MAIN LOW WILL BE CROSSING THE ROCKIES. MOISTURE
CONTINUES TO INCREASE AHEAD OF THE LOW AND FRIDAY LOOKS TO SEE A
WAVE OR TWO OF SHOWERS TO ROTATE THROUGH THE AREA. BETTER
MOISTURE LIFT ASSOCIATED CLOSER TO THE LOW...WHICH FAVORS HIGHER
POPS ACROSS SW NEB.
A SECOND WAVE...CLIPPER...QUICKLY FOLLOWS FOR THE WEEKEND. SHOULD
SEE A BRIEF BREAK IN THE ACTIVITY BEFORE THE SECOND WAVE
ARRIVES...ALTHOUGH TIMING THE BREAK IS DIFFICULT DUE TO MODEL
DIFFERENCES. FORECAST DOES RETAIN LOW POPS AND EXPECT THIS TO
CHANGE IN THE COMING DAYS AS THE LULL IN ACTIVITY BECOMES MORE
CLEAR. AT THIS TIME MODELS ARE IN FAVOR OF THE DRY PERIOD TO
OCCUR SOMETIME SATURDAY...EARLIEST IS THE GEM/GFS...WHILE LATER
IS FAVORED BY THE ECMWF.
THE NEXT WAVE SHOULD BE EAST OF THE AREA TO START THE WORK WEEK
DRY AND MILD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1130 PM CDT MON APR 20 2015
FOR THE REMAINDER OF TONIGHT...SCATTERED TO BROKEN CIGS OF AROUND
10000 FT AGL ARE POSSIBLE THROUGH 12Z TUESDAY MORNING WITH
CLEARING THEREAFTER. SCATTERED CIGS AROUND 9000 TO 10000 FT AGL
ARE POSSIBLE DURING THE AFTERNOON HOURS WITH CLEARING EXPECTED
TUESDAY EVENING. WINDS WILL BE LIGHT AND VARIABLE AT UNDER 10 KTS
THROUGH MID MORNING...BECOMING WEST AND INCREASING TO 10 TO 20
KTS AROUND MIDDAY TUESDAY. SOME GUSTS TO 25 KTS ARE POSSIBLE
DURING THE LATE AFTERNOON HOURS. WINDS WILL SHIFT TO THE NORTH
AROUND 00Z WEDNESDAY AND WILL BE IN THE 10 TO 15 KT RANGE THROUGH
06Z WEDS.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...CLB
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
415 AM EDT TUE APR 21 2015
.SYNOPSIS...
A STRONG LOW PRESSURE SYSTEM OVER THE GREAT LAKES WILL BRING VERY
WINDY CONDITIONS TODAY...ALONG WITH A CHANCE OF SHOWERS AT TIMES
THROUGH WEDNESDAY MORNING. DRIER CONDITIONS ARE EXPECTED FROM
WEDNESDAY AFTERNOON THROUGH THE REST OF THE WEEK...WITH BREEZY
AFTERNOONS AND COOL TEMPERATURES. ANOTHER CHANCE OF RAIN WILL ARRIVE
ON SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SCATTERED TO BROKEN CLOUDS IN THE 6KFT-10KFT LAYER ARE CROSSING
THE ILN CWA FROM WEST TO EAST...DELINEATED VERY NICELY ON IR
SATELLITE. WITHIN THESE PATCHES OF CLOUDS ARE SOME
CONVECTIVE-LOOKING SHOWERS...AND ALTHOUGH NO LIGHTNING HAS BEEN
OBSERVED...PEA SIZE HAIL WAS OBSERVED WITH ONE OF THE SHOWERS
(THANKS TO THE FREEZING LEVELS OF AROUND 4KFT).
THE PRIMARY CONCERN TODAY REMAINS THE THREAT FOR STRONG
WINDS...AND AN ANALYSIS OF 00Z MODEL DATA SUPPORTED MAINTAINING
THE CURRENT ORIENTATION FOR THE WIND ADVISORY (WITH A SPECIAL
WEATHER STATEMENT FOR THE REST OF THE FORECAST AREA). STRONG
UNIDIRECTIONAL FLOW (AT ABOUT 250 DEGREES) EXTENDS THROUGH THE
ENTIRE DEPTH OF THE TROPOSPHERE...WITH VALUES STEADILY INCREASING
OFF THE SURFACE. USING A RECENT RAP RUN AT KDAY ON BUFKIT AS AN
EXAMPLE (AT 18Z)...WINDS INCREASE TO 40 KNOTS AT 825MB...THEN 50
KNOTS AT 700MB...AND 60 KNOTS AT 600MB. TODAY WILL BE AN EXERCISE
IN MIXING...AS THE EVENTUAL DEPTH OF THE MIXED LAYER WILL LIKELY
DETERMINE JUST HOW STRONG THE WINDS GET. GUSTS IN THIS FORECAST
WERE GENERALLY GLEANED FROM BUFKIT MOMENTUM TRANSFER VIA RAP/GFS
FORECASTS...WITH VALUES IN THE LOWER 40 KNOT RANGE IN THE NORTHERN
CWA...AND LOWER 30 KNOT RANGE IN THE SOUTHERN CWA.
ALTHOUGH CLEAR SKIES WILL BE IN PLACE AT THE BEGINNING OF THE
DAY...WEAK ELEVATED FORCING AND A SLIGHT INCREASE IN MOISTURE AT
THE TOP OF THE (RATHER HIGH) MIXED LAYER WILL RESULT IN SOME CLOUD
DEVELOPMENT...AND EVENTUALLY SHOWERS IN THE SOUTHEASTERN HALF OF
THE FORECAST AREA. THESE SHOWERS MAY BE VERY HIGH-BASED (PERHAPS
8000 FEET)...WITH SCATTERED COVERAGE AT MOST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
PRECIPITATION IS EXPECTED TO MOVE INTO THE REGION (OR PERHAPS
DEVELOP OVER THE FORECAST AREA) ON TUESDAY NIGHT INTO WEDNESDAY
MORNING. ALTHOUGH THERE ARE SOME MODEL DIFFERENCES WITH REGARDS TO
THE INTENSITY AND LAYOUT OF THE PRECIPITATION...THE OVERALL TIMING
APPEARS TO FAVOR THE 06Z-15Z TIME FRAME FOR THE ILN FORECAST
AREA...AHEAD OF A SHORTWAVE AND A SURFACE COLD FRONT. ALTHOUGH
THIS FRONT SHOWS UP NICELY ON MSLP PLOTS...THE WIND SHIFT AND
CHANGE IN AIR MASS ARE NOT ESPECIALLY NOTABLE. INSTABILITY (EVEN
ELEVATED) WILL BE HARD TO COME BY...SO THOUGH THUNDER IS NOT AN
IMPOSSIBILITY WITH THIS SETUP...THE CHANCE SEEMS VERY LOW.
ONCE THIS FRONT PASSES...VERY SIMILAR CONDITIONS ARE EXPECTED FOR
THE REST OF THE WEEK...WITH NORTHWEST FLOW AND COOL WEATHER. OHIO
IS LIKELY TO REMAIN IN BETWEEN AREAS OF ENHANCED MOISTURE FROM THE
NORTHERN AND SOUTHERN STREAMS...LEADING TO GENERALLY SUNNY
CONDITIONS UNTIL FRIDAY NIGHT.
TEMPERATURES ON THURSDAY AND FRIDAY MORNING MAY BE COOL ENOUGH FOR
FROST...BUT MOISTURE AND WIND FORECASTS ARE NOT AS FAVORABLE.
THUS...FROST WILL NOT BE INCLUDED IN THE GRIDS OR HWO.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
SOME DEEPER MOISTURE WILL BE PULLED UP TOWARD OUR AREA ON
SATURDAY AHEAD OF SHORT WAVE ENERGY MOVING OUT OF THE ROCKIES.
WHILE THE BEST FORCING/MOISTURE ASSOCIATED WITH THIS WILL REMAIN
TO OUR SOUTH...SOME PCPN COULD SNEAK UP INTO AT LEAST SOUTHERN
PORTIONS OF OUR FA EARLY IN THE WEEKEND. THIS MAY ALSO ALLOW FOR A
SLIGHT MODIFICATION IN TEMPERATURES WITH HIGHS PUSHING INTO THE
UPPER 50S TO LOWER 60S BY THE END OF THE LONG TERM PERIOD.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
LARGE SCALE UPPER LEVEL LOW CENTERED OVER THE WESTERN GREAT LAKES
THIS MORNING WILL MOVE SLOWLY EAST THROUGH THE TAF PERIOD. EMBEDDED
DISTURBANCES ROTATING AROUND THE LOW WILL AFFECT OUR REGION FROM
TIME TO TIME.
FOR EARLY THIS MORNING...THERE WILL BE A LULL IN SIGNIFICANT
WEATHER ACTIVITY. MID CLOUDS CURRENTLY OVER THE REGION WILL PUSH
OFF TO THE EAST...LEAVING MOSTLY CLEAR CONDITIONS BY 12Z.
FOR TODAY...STRONG SURFACE LOW PRESSURE WILL REMAIN NORTH OF THE
GREAT LAKES. MEANWHILE...A COLD FRONT WILL APPROACH THE REGION
FROM THE WEST. THE INCREASING SURFACE PRESSURE GRADIENT COMBINED
WITH DEEP MIXING WILL RESULT IN WINDY CONDITIONS FROM MID MORNING
INTO EARLY EVENING. WINDS WILL VEER FROM A SOUTHWEST TO A
WEST/SOUTHWEST DIRECTION WITH WIND GUSTS IN THE 30 TO 40 KNOT
RANGE. MODELS CONTINUE TO INDICATE THAT SOME MOISTURE IN THE LOW
TO MID LEVEL WILL DEVELOP/ADVECT NORTHEAST INTO THE REGION BY THIS
AFTERNOON. THIS CLOUD LAYER COULD BECOME CONVECTIVE ENOUGH TO
PRODUCE A FEW SPRINKLES OR LIGHT SHOWERS...MAINLY ALONG AND SOUTH
OF THE OHIO RIVER.
FOR TONIGHT...ONE OF THOSE EMBEDDED DISTURBANCES WILL DIG
SOUTHEAST INTO OUR AREA. THIS FEATURE WILL TEAM UP WITH FRONTAL
CONVERGENCE FROM THE ADVANCING COLD FRONT TO BRING A THREAT OF
SHOWERS TO THE TAF SITES BETWEEN 06Z AND 12Z. THERE COULD BE SOME
POCKETS OF MVFR VISIBILITIES ASSOCIATED WITH THE MORE ROBUST
SHOWERS.
OUTLOOK...GUSTY WEST TO NORTHWEST WINDS UP TO 30 KNOTS EXPECTED
WEDNESDAY AFTERNOON INTO EARLY EVENING.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...WIND ADVISORY FROM 11 AM THIS MORNING TO 8 PM EDT THIS EVENING
FOR OHZ026-034-035-042>046-051>056-060>062.
KY...NONE.
IN...WIND ADVISORY FROM 11 AM THIS MORNING TO 8 PM EDT THIS EVENING
FOR INZ050.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...HATZOS
SHORT TERM...HATZOS
LONG TERM...JGL
AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS NORMAN OK
358 AM CDT TUE APR 21 2015
.DISCUSSION...
THE FORECAST CHALLENGE OF THE DAY IS SEVERE WEATHER POTENTIAL
THROUGH FRIDAY.
THIS MORNING...ISOLATED TO SCATTERED SHOWERS FROM WEAK MID LEVEL
MOISTURE CONVERGENCE/ISENTROPIC LIFT WILL CONTINUE MAINLY ACROSS
SOUTHERN OKLAHOMA. CANNOT RULE OUT A RUMBLE OF THUNDER...BUT NO
SEVERE WEATHER WILL OCCUR. ANY RAINFALL WILL BE LIGHT AND UNDER
0.10 INCH.
THIS AFTERNOON...SKIES WILL CLEAR AND ALLOW FOR GOOD DAYTIME
HEATING. THINK CAPPING WILL BE TOO STRONG FOR STORM
DEVELOPMENT...EXCEPT PERHAPS NEAR A WEAK SURFACE BOUNDARY OVER
SOUTHERN KANSAS ACCORDING TO THE LATEST HRRR RUN. KEPT 20 PERCENT
CHANCE FOR STORMS NEAR THE KANSAS AND OKLAHOMA STATE LINE EAST OF
ALVA AFTER 4 PM. IF THESE STORMS FORM...THEY COULD BE SEVERE WITH
SOME LARGE HAIL UP TO GOLF BALLS AND DAMAGING WINDS UP TO 60 MPH
AS STRONG 0-6 KM SHEAR AND MUCAPE AROUND 1000 J/KG SUPPORT SOME
SEVERE POTENTIAL.
TONIGHT...WILL MONITOR FOR ADDITIONAL STORM FORMATION...MAINLY
AFTER MIDNIGHT ACROSS WESTERN OKLAHOMA ON THE NOSE OF THE LOW
LEVEL JET. LATEST MODELS HAVE BEEN TRENDING SLOWER WITH STORM
DEVELOPMENT. WITH INCREASING ELEVATED INSTABILITY AND STRONG 0-6
KM SHEAR...STORMS WILL BEGIN WITH LARGE HAIL UP TO GOLF BALLS AS
THE MAIN HAZARD...BUT MAY TRANSITION TO SOME WIND AND HAIL AS
STORMS MAY FORM INTO A CLUSTER OR LINE THEN MOVE EAST OR SOUTHEAST
TOWARDS DAYBREAK...MAINLY AFFECTING WESTERN OKLAHOMA. A FEW
ADDITIONAL SEVERE STORMS MAY BE NEAR A DEVELOPING COLD FRONT IN
NORTHERN OKLAHOMA. WIDESPREAD SEVERE SEEMS UNLIKELY TONIGHT.
WEDNESDAY...AN ACTIVE DAY OF SEVERE WEATHER MAY OCCUR...
ESPECIALLY ACROSS THE SOUTHERN HALF OF OKLAHOMA AND NORTH TEXAS. A
COMPLEX OF STORMS MAY OCCUR DURING THE MORNING HOURS AND MOVE EAST
OR SOUTHEAST BRINGING SOME WIND AND HAIL REPORTS AS WELL AS
LOCALLY HEAVY RAINFALL. REDEVELOPMENT MAY OCCUR DURING THE
AFTERNOON AND EVENING NEAR THE OUTFLOW BOUNDARY WHICH MAY BE NEAR
THE RED RIVER. THERE IS SOME POTENTIAL FOR SIGNFICANT SEVERE
INCLUDING GIANT HAIL GREATER THAN GOLF BALLS...DAMAGING WINDS OVER
70 MPH...AND PERHAPS TORNADOES IF LOW LEVEL SHEAR IS STRONG
ENOUGH...BUT CONFIDENCE OF THIS OCCURRING REMAINS LOW AS NOT SURE
HOW THE CONVECTION DURING THE MORNING AFFECTS THE ENVIRONMENT
DURING THE AFTERNOON AND EVENING HOURS. IT APPEARS NORTHERN
OKLAHOMA MAY NOT RECEIVE MANY STORMS OR SEVERE WEATHER WHERE THE
AIR WILL BE COOLER AND MORE STABLE.
WEDNESDAY NIGHT INTO THURSDAY...A FEW SEVERE STORMS MAY LINGER
OVER FAR SOUTHERN OKLAHOMA AND NORTH TEXAS WITH LARGE HAIL...
DAMAGING WINDS...AND HEAVY RAINFALL. HOWEVER...MOST STORMS MAY BE
SOUTH OF THE RED RIVER...LEAVING BEHIND COOL AND STABLE CONDITIONS
ACROSS OKLAHOMA. CONFIDENCE OF SEVERE STORMS DURING THIS TIME
FRAME REMAINS LOW AS NOT SURE HOW WEDNESDAY/S CONVECTION CHANGES
THE AIRMASS ACROSS THE REGION. WENT BELOW MODEL GUIDANCE
TEMPERATURES.
FRIDAY...ANOTHER ROUND OF SEVERE THUNDERSTORMS...POSSIBLY WITH
SIGNIFICANT SEVERE...MAY RETURN TO THE AREA. VERY STRONG
SHEAR/WINDS WOULD SUPPORT FAST MOVING SUPERCELLS. HOWEVER...
MOISTURE AND INSTABILITY REMAIN QUESTIONABLE...ESPECIALLY AS
CONVECTION OVER TEXAS MAY LIMIT THE NORTHWARD PROGRESS OF RICHEST
MOISTURE AND HIGHEST INSTABILITY. REGARDLESS...WILL CLOSELY
MONITOR. ELEVATED TO CRITICAL FIRE WEATHER CONDITIONS ALONG WITH
WINDY AND HOT WEATHER MAY FORM BEHIND A DRYLINE.
SATURDAY THROUGH MONDAY...A QUIETER WEATHER PATTERN IS FORECAST
WITH NEAR AVERAGE TEMPERATURES.
MBS
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 77 54 69 54 / 20 20 50 40
HOBART OK 77 54 73 54 / 10 40 70 40
WICHITA FALLS TX 78 57 76 57 / 10 20 40 40
GAGE OK 79 49 66 46 / 10 40 40 30
PONCA CITY OK 78 49 64 47 / 20 30 30 30
DURANT OK 76 57 75 60 / 30 10 60 40
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
25/17
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
442 AM CDT TUE APR 21 2015
.SHORT TERM (TODAY THROUGH WEDNESDAY)...
A WEAK UPPER LEVEL DISTURBANCE MOVED OVER THE AREA OVERNIGHT AND
CLEARING SKIES ARE LEFT IN ITS WAKE. THE CLEARING SHOULD BE
TEMPORARY AS A MOIST LAYER AT 850 HPA SHOULD SATURATE IN MANY
AREAS. THE CLOUDS WILL PROBABLY BE SCT VARIABLE TO BKN SINCE THE
MOISTURE LAYER APPEARS THIN. THUS WILL GO WITH SLIGHTLY ABOVE
BLENDED GUIDANCE HIGHS TODAY. RAP SOUNDINGS SUGGEST A BREAKABLE
CAP SHOULD THERE BE ENOUGH MOISTURE SO WILL CONTINUE WITH ISOLATED
POPS. AN UPPER LOW CURRENTLY OVER SOUTHERN CA WILL CONTINUE TO
CARVE DEEPER OVER THE BAJA PENINSULA THROUGH WEDNESDAY. DEEPENING
MOISTURE WILL LEAD TO INCREASED RAIN CHANCES AND A FEW STRONG
STORMS AND POSSIBLE SUPERCELLS AS NOTED IN THE SPC DAY 2 OUTLOOK.
&&
.LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)...
A FAIRLY LIGHT LOW LEVEL FLOW WEDNESDAY NIGHT INTO THURSDAY MEANS
THAT THERE COULD BE SOME REMNANT OUTFLOW BOUNDARIES LEFT FROM
WEDNESDAY STORMS TO BRING ADDITIONAL STORM FOCUS FOR THURSDAY AS
THE UPPER LOW BEGINS TO LIFT INTO THE SOUTHERN ROCKIES. HIGHEST
POPS OF THE WEEK ARE THUS SAVED FOR THURSDAY NIGHT INTO FRIDAY.
THE EJECTION OF THE LOW INTO A SHALLOW TROUGH LEAVES SOME COVERAGE
UNCERTAINTIES THIS FAR SOUTH...SO DO NOT WANT TO OVER-ADVERTISE
THE SEVERE THREAT BEYOND A NOD IN THE HWO. POPS SHOULD LOWER
SATURDAY INTO SUNDAY AS FLAT RIDGING ALOFT RETURNS. MOISTURE IS
SUFFICIENT FOR STORMS...BUT EXPECT A STRONGER CAPPING INVERSION.
ANOTHER LOW LATITUDE UPPER DISTURBANCE IS FORECAST BY THE GFS TO
BRING RAIN AND STORMS BY MIDWEEK...BUT WILL KEEP WITH THE MORE
CONSERVATIVE ECMWF UNTIL THE PATTERN DIFFERENCES BETWEEN MODELS
DECREASE. TEMPERATURES THROUGH THE PERIOD SHOULD CONTINUE TO BE
SEASONAL. A WEAK FRONT EXPECTED SATURDAY WILL PROBABLY ADD TO
DAYTIME TEMPERATURES THROUGH REDUCED CLOUDINESS.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 80 66 82 69 86 / 20 10 30 30 20
AUSTIN BERGSTROM INTL AIRPORT 79 66 81 68 85 / 20 10 30 30 20
NEW BRAUNFELS MUNI AIRPORT 79 66 82 69 87 / 20 20 30 30 20
BURNET MUNI AIRPORT 77 66 81 68 85 / 20 20 30 30 20
DEL RIO INTL AIRPORT 81 67 86 70 88 / 20 20 20 10 20
GEORGETOWN MUNI AIRPORT 79 67 82 68 86 / 20 10 30 30 20
HONDO MUNI AIRPORT 82 67 82 69 87 / 20 20 30 20 20
SAN MARCOS MUNI AIRPORT 78 66 81 68 85 / 20 20 30 30 20
LA GRANGE - FAYETTE REGIONAL 79 66 82 70 85 / 20 10 30 30 20
SAN ANTONIO INTL AIRPORT 80 68 82 71 86 / 20 20 30 20 20
STINSON MUNI AIRPORT 81 68 82 71 87 / 20 20 30 20 20
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...17
SYNOPTIC/GRIDS...18
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
410 AM EDT TUE APR 21 2015
.SYNOPSIS...
A COLD FRONT WILL CONTINUE TO MOVE EAST THROUGH VIRGINIA AND WILL
REACH THE COAST THIS MORNING. HIGH PRESSURE OVER THE SOUTHERN
PLAINS WILL MOVE EAST TO THE COAST BY WEDNESDAY MORNING. ANOTHER
FRONT WILL MOVE THROUGH THE AREA ON WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 400 AM EDT TUESDAY...
LOCAL NATIONAL WEATHER SERVICE RADAR SHOWED WIDELY SCATTERED
SHOWERS IN THE MOUNTAINS EARLY THIS MORNING. EVEN THOUGH UPSLOPE
FLOW CONTINUES THROUGH THE DAY...HAVE ENDED THE SHOWERS AFTER
THIS MORNING AND EXPECT A CLEARING SKY THIS AFTERNOON AS THE AIR
MASS DRIES OUT. HRRR SUGGESTS SHOWERS MAY BE GONE AS EARLY AT 7AM.
SURFACE DEW POINTS ALREADY DROPPING INTO THE 30S AND
40S BEHIND THE COLD FRONT THAT EXTENDED FROM EASTERN PENNSYLVANIA
TO THE FLORIDA PANHANDLE. DRIER AIR ALOFT MAY BE SEEN ON THE WATER
VAPOR LOOP ADVANCING ACROSS THE CENTRAL AND SOUTHERN APPALACHIANS.
THE DOWNSLOPE WINDS WILL AIDE IN DRYING AND WARMING THE AIR EAST
OF THE BLUE RIDGE. EXPECT HIGHS IN THE EAST TO BE ON THE WARMER
SIDE OF GUIDANCE. BUFKIT FORECAST SOUNDINGS SHOWED DEEP MIXING
WHICH WILL AIDE IN TRANSPORTING DRIER AIR DOWN TO THE SURFACE.
THE DEEP MIXING AND PRESSURE RISES OF 3 TO 6 MB IN 6 HOURS WILL
RESULT IN GUSTS AS HIGH AS 35 MPH.
WINDS WILL DIMINISH TONIGHT AFTER SUNSET. LATER TONIGHT CLOUDS
INCREASE AHEAD OF AN APPROACHING COLD FRONT. MODELS HOLD THE
POTENTIAL FOR PRECIPITATION WEST OF THE FORECAST AREA UNTIL AFTER
07Z/3AM. LOW LEVEL JET FROM THE SOUTH-SOUTHWEST ALSO INCREASES TO
NEARLY 45 KNOTS BY LATE TONIGHT. HAVE STRONG GUSTS...BUT STILL
UNDER ADVISORY CRITERIA...AT HIGHER ELEVATIONS AFTER MIDNIGHT.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 330 AM EDT TUESDAY...
THE CLOSED UPPER LOW WILL CONTINUE TO DO A SIT AND SPIN OVER THE GREAT
LAKES REGION THROUGH THE SHORT TERM PERIOD....KEEPING OUR TEMPERATURES
AT OR SLIGHTLY BELOW NORMAL. BY WEDNESDAY MORNING A SPOKE OF ENERGY
ROTATING AROUND THE UPPER LOW WILL BE PUSHING A COLD FRONT INTO THE
AREA FROM THE WEST. MOISTURE/INSTABILITY ARE LIMITED BUT LAPSE RATES
ARE STEEP SO SOME SHOWERS AND THUNDERSTORMS WILL BE ABLE TO DEVELOP
AHEAD OF THE FRONT. THE BIG FEATURE OF NOTE WILL BE THE SYNOPTIC WINDS.
THE LOW LEVEL WIND FIELD WILL BE RAMPING UP TO 40KTS/50KTS AND MODEL
SOUNDINGS SHOW A VERY WELL MIXED AND DRY BOUNDARY LAYER THAT WILL BE
EFFICIENT FOR DOWNWARD MOMENTUM TRANSFER...ESPECIALLY AS COLDER AIR
STARTS TO WORK IN BEHIND THE FRONT. BELIEVE THE SITUATION WILL REMAIN
BELOW ADVISORY CRITERIA BUT THE RIDGES MAY SEE GUSTS AROUND 40MPH. ANY
SHOWERS/STORMS WILL ALSO HAVE PLENTY OF WIND TO MIX DOWN SO EVEN
UNIMPRESSIVE CONVECTIVE CLUSTERS MAY BE QUITE GUSTY.
BEHIND THE FRONT WE SHOULD GET ENOUGH HIGH PRESSURE BUILDING IN FROM
THE NORTHWEST TO KEEP THINGS QUIET...THOUGH BREEZY...THROUGH THE END OF
THE WORKWEEK. TEMPERATURES HAVE BEEN TRENDING COLDER FOR BOTH MAX/MIN
TEMPS THURSDAY AND FRIDAY...SO WILL BE SHADING GRIDS IN THAT DIRECTION.
SOME OF THE HIGHER TERRAIN WEST OF THE BLUE RIDGE WILL BE FLIRTING WITH
TEMPERATURES APPROACHING THE FREEZING MARK BOTH MORNINGS. HOWEVER...THE
AG PROGRAM WILL NOT BE IN FULL SWING WEST OF THE RIDGE UNTIL MAY 1 SO
THIS IS NOT LIKELY TO CAUSE ANY SIGNIFICANT PROBLEMS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
AS OF 130 PM EDT MONDAY...
NOT MUCH CHANGE TO THIS FORECAST. A SOUTHERN STREAM LOW
ARRIVES OVER THE AR/OK BORDER BY SATURDAY MORNING WITH OVERRUNNING
CLOUDS WORKING INTO THE AREA FRIDAY AHEAD OF A WARM FRONT. BY
SATURDAY ENOUGH MOISTURE TO ALLOW FOR SHOWERS TO FORM BY SATURDAY
MORNING WITH BEST FORCING ACROSS THE CAROLINAS. THIS SYSTEM EXITS BY
SAT NIGHT WITH SUNDAY BEING A DRY AND COOL/MILD DAY WITH HIGHS IN
THE 50S MOUNTAINS TO 60S EAST. HIGH PRESSURE TO ASSUME POSITION OVER
THE OHIO VALLEY INTO THE SRN APPALACHIANS MONDAY TO KEEP THINGS DRY.
NEXT SOUTHERN STREAM SYSTEM MAY WORK SOME SHOWERS OUR WAY BY TUESDAY.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
AS OF 145 AM EDT TUESDAY...
COLD FRONT WAS EAST OF THE BLUE RIDGE EARLY THIS MORNING AND WAS
CLOSE TO CROSSING THROUGH KLYH AND KDAN AT 06Z/2AM. HAVE THE FRONT
PASSING THROUGH THESE STATIONS AND WINDS BECOMING WEST BY 08Z/4AM.
PRESSURE RISES BEHIND THE FRONT WILL BRING WIND GUSTS OF 20 TO 30
KNOTS THROUGH MID TO LATE AFTERNOON. AFTER SUNSET WINDS WILL
DIMINISH TO LESS THAN 10 KTS.
CURRENTLY SOME MVFR CEILINGS IN THE MOUNTAINS AND RAPIDLY
DISSIPATING SHOWERS. LOWER CONFIDENCE ABOUT HOW WIDESPREAD MVFR
CEILINGS WILL BE BEFORE 12Z/8AM. VFR CONDITIONS WILL RETURN THIS
AFTERNOON WITH HIGH PRESSURE BUILDING IN BEHIND THE FRONT.
EXTENDED AVIATION...
THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY AND THURSDAY WITH THE PASSAGE OF A
COLD FRONT.
HIGH PRESSURE AT THE SURFACE BUILDS SOUTHEAST FROM THE OHIO
VALLEY THURSDAY NIGHT INTO FRIDAY. OVERRUNNING CLOUDS WORK INTO
THE AREA FRIDAY AHEAD OF A WARM FRONT. BY SATURDAY...ENOUGH
MOISTURE TO ALLOW FOR SHOWERS WITH BEST FORCING ACROSS THE
CAROLINAS.
&&
.HYDROLOGY...
AS OF 405 AM EDT TUESDAY...
AFTER THE IMPRESSIVE RAINFALL SINCE SUNDAY MORNING...WHICH SAW
OVER 6 INCHES AT A FEW GAGES IN ALLEGHANY COUNTY NC...RIVERS AND
LARGE CREEKS IN THE NEW RIVER AND UPPER ROANOKE VALLEYS HAVE
MOSTLY CRESTED AND ARE FALLING.
STAGES ALONG THE MAINSTEM NEW RIVER WILL CONTINUE TO FALL.
ALLISONIA AND RADFORD HAVE RECEDED BACK BELOW FLOOD STAGE.
RIVER FLOOD WARNINGS CONTINUE FOR THE LOWER ROANOKE RIVER AT
RANDOLPH AND AT DANVILLE AND SOUTH BOSTON ON THE DAN FOR MINOR
FLOODING.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...MBS
LONG TERM...WP
AVIATION...AMS/JH
HYDROLOGY...AMS/PC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
341 AM CDT TUE APR 21 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 341 AM CDT TUE APR 21 2015
MAIN FCST CONCERNS THIS PERIOD...STRONG WINDS THIS AFTERNOON...
-SHRA/-SHSN CHANCES TODAY INTO THIS EVENING...TEMPERATURES.
06Z DATA ANALYSIS HAD A 984 MB LOW SOUTHWEST OF JAMES BAY CANADA
WITH BROAD TROUGHING TO THE SOUTHWEST INTO NORTHERN MN. TIGHT
PRESSURE GRADIENT AND STEEPER LOW LEVEL LAPSE RATES REMAINED ACROSS
THE REGION...ESPECIALLY MN/WI WHERE WEST TO NORTHWEST WINDS OF 15 TO
20MPH GUSTING 25-35 MPH WERE QUITE COMMON. ONE SHORTWAVE OVER
NORTHERN MN INTO NORTHWEST WI WITH THE MID LEVEL LOW COMBINED WITH
SOME DEEPER MOISTURE AND TIGHTER 925-700MB CYCLONIC FLOW/
CONVERGENCE WERE PRODUCING SOME -SN/-SHSN OVER NORTHEAST MN INTO THE
NORTHWEST 1/4 OF WI. FURTHER SOUTH...WIDELY SCT -SHRA/-SHSN NOTED
OVER EAST CENTRAL MN INTO WESTERN WI.
21.00Z MODELS LOOK TO HAVE INITIALIZED WELL. SOLUTIONS QUITE SIMILAR
AS THE MID LEVEL LOW OVER NORTHERN MN DROPS ACROSS THE U.P. OF MI
TODAY THIS MORNING/EARLY THIS AFTERNOON...THEN LIFTS INTO EAST
CENTRAL ONTARIO LATE TODAY/TONIGHT. SOLUTIONS GENERALLY FAVOR
COMPROMISE OF THE EARLIER RUNS WITH DEEP...COLD CYCLONIC FLOW OVER
THE UPPER MIDWEST THIS PERIOD. SOME DIFFERENCES ON LIGHT QPF
PRODUCTION UNDER/SOUTH OF THE MID LEVEL LOW TODAY BUT THIS NOT
UNEXPECTED. OVERALL SHORT-TERM FCST CONFIDENCE IS GOOD THIS CYCLE.
IN THE SHORT TERM...TIGHT PRESSURE GRADIENT REMAINS OVER THE AREA
AGAIN TODAY...WITH STEEP LOW LEVEL LAPSE RATES/MIXING TO 850MB THIS
AFTERNOON. BIT MORE WIND IN THE MIXED PORTION OF COLUMN THAN
SUNDAY...25-30KTS AT 925MB AND AROUND 35KTS AT 850MB. 700MB TEMPS
AROUND -16C AS WELL THIS AFTERNOON WITH POTENTIAL OF MIXING TO
800MB. WILL MATCH UP WITH THE NEIGHBORS AND ISSUE A WIND ADVISORY
FOR ROUGHLY THE SOUTHWEST 1/3 OF THE FCST AREA FROM 16Z-23Z TODAY.
MODEL SOUNDINGS/X-SECTIONS SHOWING CONSIDERABLE MOISTURE/SATURATION
IN THE 900-500MB LAYER TO ROTATE ACROSS ROUGHLY THE NORTHEAST 2/3 OF
THE FCST AREA TODAY. THIS WITH THE -16C 700MB COLD POOL...A LOBE OF
VORTICITY ROTATING AROUND THE UPPER LOW AND THE TIGHTER 925-700MB
CYCLONIC CONVERGENCE...SETS THE STAGE FOR AT LEAST SCT -SHRA/-SHSN
ACROSS THE NORTHEAST HALF OF THE FCST AREA TODAY. RAISED PRECIP
CHANCES A BIT TODAY ACROSS THE NORTHEAST HALF OF THE FCST AREA...
WITH 60+ PERCENT ACROSS THE FAR NORTH END. COLUMN COLD ENOUGH FOR -
SHSN AS FAR SOUTH AS I-90 THRU MID MORNING. DIURNAL WARMING/ MIXING
OF LOWER PORTION OF THE COLUMN LOOKS TO CHANGE BULK OF PRECIP TO -
SHRA BY LATE MORNING...BUT STRONGER SHOWER CORES AND DRIER AIR BELOW
900MB FOR EVAPORATIVE COOLING MAY ALLOW SOME -SN/SLEET/SNOW PELLET
SHOWERS TO OCCUR WELL INTO THE AFTERNOON. DAY CREW WILL HAVE TO
MONITOR WARMING...AND OBS...AND MAY NEED TO INCLUDE THAT IN GRIDS AS
THE DAY WEARS ON. SECONDARY SHORTWAVE ROTATES IN AND ACROSS THE
AREA THIS EVENING...WITH A BETTER PV ADVECTION SIGNAL. RAISED
-SHRA/ -SHSN CHANCES/LINGERED THEM LONGER OVER THE EAST SIDE OF
THE FCST AREA THIS EVENING. 925-500MB SUBSIDENCE AND DRYING OF THE
COLUMN SPREADS ACROSS THE FCST AREA LATE THIS EVENING/OVERNIGHT...
WITH AND END TO THE -SHRA/-SHSN. SOME CLEARING LATER TONIGHT AS
WELL. PRESSURE GRADIENT CONTINUES TO RELAX TONIGHT BUT SFC WINDS
LOOKING TO REMAIN IN THE 7-14KT RANGE FOR BOUNDARY LAYER MIXING.
EVEN WITH THE WINDS...LOWS LOOKING TO FALL TO NEAR/BELOW FREEZING.
A BIT EARLY FOR FROST/FREEZE HEADLINES AT THIS POINT...BUT ANOTHER
WEEK OF THE WARMER TEMPS OF LAST WEEK WOULD HAVE LIKELY MADE THEM
NEEDED. USED A BLEND OF THE GUIDANCE HIGHS/LOWS FOR TODAY/TONIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 341 AM CDT TUE APR 21 2015
MAIN FCST CONCERNS FOR WED THRU THU NIGHT...COLD TEMPERATURES.
20.12Z MODELS IN GOOD AGREEMENT WED/WED NIGHT FOR THE MID LEVEL LOW/
TROUGH AXIS TO DRIFT SLOWLY EAST...WITH THE UPPER MIDWEST UNDER A
COLD NORTHWEST FLOW ALOFT. HGTS SLOWLY RISE THU/THU NIGHT AS THE LOW
PULLS INTO MAINE/QUEBEC AND TROUGHING MOVES INTO THE ROCKIES BUT
FLOW REMAINS OUT OF THE NORTHWEST. WITH THE TIGHTER/IMPROVING
CONSENSUS...FCST CONFIDENCE IN THE WED THRU THU NIGHT PERIOD IS GOOD
THIS CYCLE.
THE WED THRU THU NIGHT PERIOD IS DOMINATED BY SEASONABLY COLD AND
DRY CAN HIGH PRESSURE. SOME MOISTURE FROM LK SUPERIOR...STEEP LOW
LEVEL LAPSE RATES AND THE COLD AIR ALOFT LOOK TO SPREAD A SMALL -
SHRA/-SHSN CHANCE INTO THE FAR NORTH END OF THE FCST AREA WED...
OTHERWISE WED-THU NIGHT TREND DRY AS THE SFC RIDGE AXIS SLOWLY
DRIFTS EAST TOWARD/OVER THE AREA. 925MB TEMPS IN THE 0C TO -6C RANGE
AT 12Z THU AND IN THE +4C TO -2C RANGE AT 12Z FRI. NAEFS SHOWING
850MB TEMPS 1 TO 2 STANDARD DEVIATIONS BELOW NORMAL ACROSS MUCH OF
THE UPPER MIDWEST THRU 12Z FRI. SFC RIDGE AXIS MAY BE CLOSE ENOUGH
FOR WINDS TO DECOUPLE WED NIGHT BUT THIS LOOKS MORE CERTAIN THU
NIGHT WITH THE RIDGE AXIS SOMEWHERE OVER WI. BOTH NIGHT TRENDING
COLD WITH LOWS NEAR OR BELOW 32F. AGAIN...A WEEK OR SO LATER IN THE
SEASON/MORE ADVANCED GROWTH/DEVELOPMENT OF VEGETATION AND FROST/
FREEZE HEADLINES WOULD BE NEEDED. APPROACH OF THE HIGH PRESSURE AND
SLOWLY RISING HGTS ALOFT TO BRING MORE SUNSHINE TO THE AREA
WED/THU. DEEP MIXING TO 750MB INDICATED FOR WED...WITH WINDS IN THE
900-750MB PORTION OF THE COLUMN STILL IN THE 20-30KT RANGE. BREEZY
AGAIN WED AFTERNOON...BUT LESS SO THAN SUNDAY AND TODAY. MORE
SUNSHINE WED/THU WILL HELP HIGH TEMPS RECOVER INTO THE 50S. USED
A BLEND OF THE GUIDANCE HIGHS/LOWS FOR WED THRU THU NIGHT.
FOR FRIDAY THRU MONDAY...DAYS 4 TO 7...
MAIN FCST CONCERNS THIS PERIOD...MAINLY RAIN CHANCES FRI/FRI NIGHT
AND AGAIN LATE SUN INTO MON...TEMPERATURES.
21.00Z MEDIUM RANGE MODELS IN GENERAL AGREEMENT FOR THE PATTERN TO
BE PROGRESSIVE FRI/SAT WITH RISING HGTS OVER THE EASTERN CONUS AND
TROUGHING MOVING THRU THE ROCKIES INTO THE PLAINS. HOWEVER PLENTY OF
SHORTWAVE DETAIL DIFFERENCES ALREADY BY FRI...WHICH WOULD IMPACT THE
SENSIBLE WEATHER ACROSS THE UPPER MIDWEST. AGREEMENT FOR WEAK SHORT-
WAVE RIDGING OT BUILD INTO THE REGION SAT. NEXT STRONGER TROUGHING
IS INTO THE PLAINS SUNDAY...THEN APPROACHING/CROSSING THE REGION SUN
NIGHT/MON. RUN-TO-RUN CONSISTENCY LEAVES QUITE A BIT TO BE DESIRED
BY SUN/MON WITH TROUGHS OFF BOTH COASTS AND UNCERTAIN FLOW ACROSS
THE CONUS BETWEEN THEM. FCST CONFIDENCE FOR FRI THRU MON...AS FAR AS
PRECIP CHANCES IS BELOW AVERAGE. AVERAGE CONFIDENCE FOR TEMPERATURES
TO RETURN TO NEAR NORMAL BY SUN/MON.
TROUGHING MOVING INTO THE PLAINS FRI DEVELOPS LOW PRESSURE OVER THE
CENTRAL/SOUTHERN PLAINS...BUT QUESTION IS NOW FAR NORTH INTO THE
MID/UPPER MS VALLEY THE INFLUENCE OF THIS LOW GETS. ECMWF/GEM WITH
MORE SHORTWAVE RIDGING AHEAD OF THIS FEATURE...AND WOULD SPREAD
MOISTURE/PRECIP CHANCES INTO MN/IA/WI FRI/FRI NIGHT. GFS WITH LESS
SHORTWAVE RIDGING HOLDS NORTHWEST FLOW ALOFT OVER THE REGION THRU
FRI NIGHT...AND KEEPS MN/IA/WI DRY. WITH LESSER CONFIDENCE STAY WITH
THE SMALL CONSENSUS MAINLY -SHRA CHANCES FRI/FRI NIGHT. RISING HGTS/
SHORTWAVE RIDGING WOULD BRING DRY HIGH PRESSURE TO THE REGION FOR
SAT/SAT NIGHT. NEXT TROUGH THRU THE ROCKIES DEVELOPS LEE TROUGHING
FROM MT TO TX ON SUN...WITH SOME FORM OF THIS TROUGH/LOW PUSHING
INTO THE MID/UPPER MS VALLEY SUN NIGHT/MON. DEEPER SOUTHERLY FLOW
AHEAD OF THIS SYSTEM WOULD BRING WARMER LOW LEVEL AIR/INCREASING
MOISTURE NORTHWARD FOR SUN INTO MON. RAIN CHANCES OF 20-30 PERCENT
SUN NIGHT/MON PER THE MODEL/ENSEMBLE CONSENSUS APPEAR REASONABLE.
MODEL/ENSEMBLE CONSENSUS OF THE HIGHS/LOWS FOR FRI THRU MON ALSO
APPEAR WELL TRENDED FOR NOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1140 PM CDT MON APR 20 2015
THE WESTERN EDGE OF THE CLOUD DECK HAS BEEN ERODING SOME THIS
EVENING. HOWEVER...LOOKING UPSTREAM INTO MINNESOTA...IT LOOKS LIKE
THE WESTERN EDGE HAS BEEN HOLDING FIRM AND AS THIS ROTATES DOWN
ACROSS THE AREA...EXPECT THAT SKIES WILL BE REMAIN BROKEN TO
OVERCAST THROUGH TUESDAY. FOR THE MOST PART THE CEILINGS HAVE
REMAINED VFR...BUT STILL EXPECTING THESE TO COME DOWN TO MVFR.
CURRENT MVFR CEILINGS ARE UPSTREAM OVER CENTRAL MINNESOTA AND
THESE SHOULD ROTATE ACROSS THE AREA OVERNIGHT. STILL SOME RETURNS
ON THE RADAR WITH THE 21.02Z HRRR CONTINUING TO SHOW SOME
SCATTERED ACTIVITY THROUGH THE NIGHT...BUT CONFIDENCE THAT ANY OF
THESE WILL HIT THE TAF SITES REMAIN LOW. THE 21.00Z NAM BUFKIT
SOUNDINGS CONTINUE TO SHOW THE GOOD LOW LEVEL LAPSE RATES
REMAINING THROUGH THE ENTIRE PERIOD TO MAINTAIN THE GUSTY WEST TO
NORTHWEST WINDS. THE STRONGEST WINDS WILL COME LATE TUESDAY
MORNING THROUGH THE AFTERNOON WHEN THE MIXING BECOMES THE DEEPEST
ALLOWING THE GUSTS TO BE AROUND 30 KNOTS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...WIND ADVISORY FROM NOON TODAY TO 6 PM CDT THIS EVENING FOR
MNZ086-087-094-095.
IA...WIND ADVISORY FROM NOON TODAY TO 6 PM CDT THIS EVENING FOR
IAZ008>010-018-019-029-030.
&&
$$
SHORT TERM...RRS
LONG TERM....RRS
AVIATION.....04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1140 PM CDT MON APR 20 2015
.SHORT TERM...(TONIGHT THROUGH TUESDAY)
ISSUED AT 235 PM CDT MON APR 20 2015
500 MB LOW/UPPER LEVEL TROUGH MEANDERS SLOWLY EASTWARD ACROSS THE
UPPER MISSISSIPPI RIVER TONIGHT-TUE...THEN WOBBLES OVER SOUTHEAST
CANADA FOR A FEW DAYS. BITS OF UPPER LEVEL ENERGY WILL ROTATE AROUND
THE UPPER LEVEL FEATURE BUT THE DEEPER SATURATION HOLDS ACROSS
NORTHERN PARTS OF MN/WI. STRONG SWATH OF 925-700 MB COLD AIR
ADVECTION DRIVES SOUTHEAST TONIGHT-TUE...GREATER ACROSS IA. BUFKIT
SOUNDINGS STILL SHOWING AS MUCH AS A 100 MB LAYER OF WEAK
INSTABILITY TUE AFTERNOON...ASSOCIATED WITH A SATURATED LAYER. ALL
IN ALL...THE MIX OF CYCLONIC UPPER LEVEL FLOW...LOW LEVEL COLD AIR
ADVECTION...WEAK INSTABILITY...FAVORABLY LOW/MID LEVEL LAPSE
RATES...AND SOME SATURATION FAVORS AREAS/SCATTERED SHOWERS.
LOCATIONS TO THE NORTH WILL HAVE THE BEST CHANCES...SPREADING
SOUTHWARD TUESDAY AFTERNOON. SOME SNOW COULD MIX IN TO THE NORTH
EARLY/LATE.
BUFKIT SOUNDINGS POINT TO DEEP MIXING ON TUESDAY...ESPECIALLY SOUTH
OF I-90 INTO IOWA. MIXING UPWARDS OF 800 MB WITH MOMENTUM TRANSFER
OF 30 TO 35 KTS. SFC PRESSURE GRADIENT TUE FAIRLY SIMILAR TO THIS
AFTERNOON. EXPECTING CLOUDY/MOSTLY CLOUDY CONDITIONS FOR THE I-90
CORRIDOR NORTHWARD...LIMITING THE MIXING. WITH MORE SUN SOUTH...FULL
MIXING COULD BE REALIZED. SEE SOME POTENTIAL FOR WIND ADV TUE
AFTERNOON - ESPECIALLY PARTS OF NORTHEAST IA. SOMETHING TO WATCH.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 235 PM CDT MON APR 20 2015
GOOD AGREEMENT IN THE MODELS WITH PERSISTENT COOL NORTHWEST FLOW
THROUGH THE REST OF THE WORK WEEK. DIFFERENCES CROP UP FOR THE
WEEKEND AS THE ECMWF/GEM POINT TO SOME WEAK UPPER LEVEL RIDGE
BUILDING WHILE THE GFS MAINTAINS THE TROUGH - EVEN DEEPENING
IT/CARVING IT OUT MORE. WHILE ALL SOLUTIONS FAVOR KEEPING THE LOCAL
AREA DRY...THERE WOULD BE IMPACTS ON TEMPS. THE GFS WOULD KEEP HIGHS
IN THE LOW/MID 50S WHILE THE EC POINTS TO A RETURN TO NORMAL -
AROUND 60. MODELS HAVE BEEN FAIRLY CONSISTENT WITHIN
THEMSELVES...BUT STILL NOT SOLD ON THE RIDGING. WILL STICK WITH
CONSENSUS SOLUTIONS FOR THE WEEKEND FOR NOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1140 PM CDT MON APR 20 2015
THE WESTERN EDGE OF THE CLOUD DECK HAS BEEN ERODING SOME THIS
EVENING. HOWEVER...LOOKING UPSTREAM INTO MINNESOTA...IT LOOKS LIKE
THE WESTERN EDGE HAS BEEN HOLDING FIRM AND AS THIS ROTATES DOWN
ACROSS THE AREA...EXPECT THAT SKIES WILL BE REMAIN BROKEN TO
OVERCAST THROUGH TUESDAY. FOR THE MOST PART THE CEILINGS HAVE
REMAINED VFR...BUT STILL EXPECTING THESE TO COME DOWN TO MVFR.
CURRENT MVFR CEILINGS ARE UPSTREAM OVER CENTRAL MINNESOTA AND
THESE SHOULD ROTATE ACROSS THE AREA OVERNIGHT. STILL SOME RETURNS
ON THE RADAR WITH THE 21.02Z HRRR CONTINUING TO SHOW SOME
SCATTERED ACTIVITY THROUGH THE NIGHT...BUT CONFIDENCE THAT ANY OF
THESE WILL HIT THE TAF SITES REMAIN LOW. THE 21.00Z NAM BUFKIT
SOUNDINGS CONTINUE TO SHOW THE GOOD LOW LEVEL LAPSE RATES
REMAINING THROUGH THE ENTIRE PERIOD TO MAINTAIN THE GUSTY WEST TO
NORTHWEST WINDS. THE STRONGEST WINDS WILL COME LATE TUESDAY
MORNING THROUGH THE AFTERNOON WHEN THE MIXING BECOMES THE DEEPEST
ALLOWING THE GUSTS TO BE AROUND 30 KNOTS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RIECK
LONG TERM....RIECK
AVIATION...04
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
347 AM MDT TUE APR 21 2015
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 315 AM MDT TUE APR 21 2015
QUIET WEATHER THIS MORNING WITH SOME MID CLOUDS OVER SE WY KEEPING
TEMPS UP A BIT AND HINDERING ANY FOG FORMATION. NWLY FLOW ALOFT
WILL REMAIN OVER THE CWA THROUGH WEDS THEN TURN WESTERLY WEDS
NIGHT AND THURSDAY. A WEAK FRONT WILL SETTLE DOWN THE PLAINS LATER
THIS AFTERNOON INTO THIS EVENING AND LAY UP AGAINST THE MTNS BUT
NO SIGNIFICANT EFFECT SEEN FROM THIS THROUGH TONIGHT. SOME WEAK
INSTABILITY OVER WESTERN PARTS OF THE CWA SHOULD ALLOW FOR A FEW
SHOWERS TO DEVELOP THIS AFTERNOON WITH A TSTORM OR TWO NOT OUT OF
THE QUESTION. ACTIVITY WILL DECREASE THIS EVENING. AN APPROACHING
SHORTWAVE ON WEDS SHOULD ALLOW FOR SOMEWHAT BETTER COVERAGE OF
SHOWERS AND A FEW TSTORMS WEDS...MAINLY OVER SE WY WHERE SOME
MINOR UPSLOPE COMPONENT TO THE WIND SHOULD EXIST. SIMILAR PATTERN
FOR THURSDAY BUT PCPN SHOULD PROGRESS FARTHER EASTWARD OVER THE
PLAINS AND THE PANHANDLE AS THE SFC FRONT SLIPS BACK EAST.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 345 AM MDT TUE APR 21 2015
MINOR DIFFERENCES ARE APPARENT WITH THE 00Z/06Z DETERMINISTIC
MODEL GUIDANCE. FAIRLY BROAD UPPER TROUGH OVER THE INTERMOUNTAIN
WEST WILL PROGRESS EASTWARD WITH WEAK UPPER LOW MOVING SLOWLY
FROM THE FOUR CORNERS TO SOUTHEAST CO THURSDAY NIGHT AND CENTRAL
GREAT PLAINS BY FRIDAY EVENING. A SURFACE TROUGH BISECTING A PAIR
OF LOWS WILL LIE EAST OF THE LARAMIE RANGE. A RATHER MOIST
SOUTHEASTERLY UPSLOPE FLOW WITH DEW POINTS IN THE 40S COMBINED
WITH MODEST INSTABILITY /LIS -3 TO -5C/ AND WEAK UPPER LEVEL
DISTURBANCE WILL PRODUCE A DECENT COVERAGE OF SHOWERS AND
ISOLATED TSTORMS THURSDAY NIGHT AND FRIDAY. SHOWER COVERAGE
DECREASES SLIGHTLY FRIDAY NIGHT WITH THE EXIT OF THE DISTURBANCE.
SHORTWAVE TRANSITORY RIDGE ALOFT EARLY SATURDAY SLIDES EAST INTO
THE PLAINS SATURDAY AFTERNOON WHEN A STRONGER DISTURBANCE MOVES
ACROSS WY AND CO PRODUCING SCATTERED SHOWERS AND POSSIBLY A FEW
TSTORMS. THE GFS IS MORE PROGRESSIVE WITH THIS TROUGH AND CLEARS
OUT THE SHOWERS SATURDAY NIGHT WHILE THE ECMWF IS SLOWER AND KEEPS
THE CWA SHOWERY THROUGH SUNDAY. AREAS ALONG AND SOUTH OF I-80 IN
SOUTHEAST WY MAY SEE ISOLATED SHOWERS SUNDAY AFTERNOON WITH WEAK
OROGRAPHIC FLOW. A DRIER STABLE AIR MASS WILL PREVAIL MONDAY WITH
LARGE SCALE RIDGE OVER THE ROCKY MOUNTAINS. TRENDED TOWARD THE
COOLER ECMWF BIAS FOR TEMPERATURES WHICH WILL AVERAGE NEAR TO
SLIGHTLY ABOVE SEASONAL NORMALS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 239 AM MDT TUE APR 21 2015
DEVELOPMENT OF PATCHY DENSE FOG IN THE LARAMIE VALLEY EARLY THIS
MORNING IS NOT FAVORABLE GIVEN THE LARGER TEMP/DEW POINT SPREADS
AND BKN-OVC CLOUDS AROUND 8000 FT AGL. THE SREF AND HRRR PREDICT
VFR CONDITIONS. THERE COULD BE SOME MIFG AROUND...BUT SHOULD HAVE
LIMITED IMPACTS TO AVIATION. OTHERWISE...VFR WILL PREVAIL ACROSS
THE FORECAST AREA TODAY AND TONIGHT WITH OCCASIONAL MID AND HIGH
CLOUDS PASSING OVERHEAD IN NORTHWEST FLOW. IT WILL BE BREEZY WITH
WEST TO NORTHWEST SURFACE WINDS SUSTAINED 12-18 KT...GUSTING UP TO
30 KT. THE WINDS WILL DIMINISH EARLY THIS EVENING WITH THE
DECOUPLING OF THE LOW LEVEL BOUNDARY LAYER.
&&
.FIRE WEATHER...
ISSUED AT 315 AM MDT TUE APR 21 2015
CONCERNS EXPECTED TO REMAIN LOW FOR THE NEXT SEVERAL DAYS WITH
WEATHER CONDITIONS REMAINING NON-CRITICAL OVERALL. A FEW
THUNDERSTORMS WILL BE POSSIBLE MAINLY IN THE AFTERNOONS FOR THE
NEXT FEW DAYS BUT DRY LIGHTNING IS NOT EXPECTED. TEMPERATURES
WILL BE MILD THROUGH THE WEEK.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...RE
LONG TERM...MJ
AVIATION...MJ
FIRE WEATHER...RE
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1242 AM MDT TUE APR 21 2015
.UPDATE...
ISSUED AT 953 PM MDT MON APR 20 2015
MAIN CONCERN OVERNIGHT IS CERTAINLY THE POTENTIAL FOR FOG
DEVELOPMENT FOR AREAS WEST OF THE LARAMIE RANGE...INCLUDING I-80
BETWEEN RAWLINS AND LARAMIE. 00Z NAM IS KEEPING FOG AT BAY WITH
LOW BL HUMIDITIES AND A DRIER NEAR SURFACE LAYER BASED OFF THE
KLAR FORECAST SOUNDINGS. HRRR IS ALSO CONSISTENTLY SHOWING NO
DEVELOPMENT OF FOG OVERNIGHT. BASED ON THIS ENSEMBLE OF
GUIDANCE...AND SOME MID CLOUDS DEVELOPING AND MOVING IN FROM THE
NORTHWEST WITH A FORECAST WIND DIRECTION FROM THE SOUTHWEST...AM
NOT SO CONFIDENT WIDESPREAD DENSE FOG WILL DEVELOP OVERNIGHT.
LINGERING SNOWPACK AND LIGHT WINDS WILL CERTAINLY AID IN
DEVELOPMENT OF MORE PATCHY AREAS OF FOG ESPECIALLY LATE IN THE
NIGHT IN THE LARAMIE VALLEY...WITH VISIBILITIES DROPPING TO
PERHAPS ONE HALF MILE OR SO...BUT A WIDESPREAD EVENT SEEMS
UNLIKELY AT THIS TIME. THE HIGHEST PROBABILITY OF FOG WILL BE FOR
EASTERN AND SOUTHERN PORTIONS OF THE LARAMIE VALLEY...AND PERHAPS
NORTHERN CARBON COUNTY AS WELL. WILL HOLD OF ON ISSUING A DENSE
FOG ADVISORY FOR NOW DUE TO LOW CONFIDENCE...BUT WILL CLOSELY
MONITOR THE SITUATION.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 250 PM MDT MON APR 20 2015
TONIGHT...LOOKS LIKE ENOUGH INSTABILITY IN THE THETA E RIDGE ACROSS
OUR FAR SOUTHWEST COUNTIES FOR ISOLATED TO WIDELY SCATTERED EARLY
EVENING SHOWERS OVER SOUTHERN CARBON AND ALBANY COUNTIES. DRY
ELSEWHERE. BASED ON PERSISTENCE...WILL AGAIN FORECAST AREAS OF FOG
OVERNIGHT AND ESPECIALLY AFTER MIDNIGHT FOR MUCH OF CARBON COUNTY
AND ESPECIALLY OVER THE LARAMIE VALLEY AND THE SNOWPACK WHERE
TEMPERATURE AND DEWPOINT SPREADS ARE STILL ONLY 2 DEGREES AT MID
AFTERNOON.
TUESDAY...NON DESCRIPT NORTHWEST FLOW ALOFT CONTINUES. LOOKS LIKE
ENOUGH LOW AND MID LEVEL MOISTURE ALONG WITH DIFFERENTIAL HEATING
AND UPSLOPE TO GENERATE ISOLATED TO WIDELY SCATTERED AFTERNOON
SHOWERS...WITH ISOLATED THUNDERSTORMS WEST OF INTERSTATE 25.
TUESDAY NIGHT...SHOWERS AND THUNDERSTORMS SHOULD END IN THE EVENING
WITH THE LOSS OF DAYTIME HEATING AND LACK OF SIGNIFICANT
LIFTING...THOUGH STILL ENOUGH LOW AND MID LEVEL MOISTURE FOR
SCATTERED TO BROKEN CLOUD COVER...AND AREAS OF FOG ONCE AGAIN OVER
THE LARAMIE VALLEY.
WEDNESDAY...TRANSITORY RIDGING ALOFT MOVES OVERHEAD. STILL
THOUGH...ENOUGH LOW AND MID LEVEL MOISTURE AND INSTABILITY FOR
ISOLATED TO SCATTERED AFTERNOON SHOWERS AND THUNDERSTORMS WITH AN
INCREASE IN THUNDERSTORM COVERAGE DUE TO INCREASED INSTABILITY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 250 PM MDT MON APR 20 2015
SHORTWAVE RIDGE MOVES OVER THE AREA WEDNESDAY NIGHT. MOST AREAS
EAST OF THE LARAMIE RANGE WILL BE DRY...THOUGH GFS DOES SHOW SOME
LIGHT SHOWERS OUT OVER CARBON COUNTY INTO THURSDAY MORNING.
RIDGE AXIS MOVES EAST OF THE CWFA THURSDAY WITH AN UPPER SHORTWAVE
PUSHING INTO NORTHWESTERN COLORADO AND WESTERN WYOMING. BOTH THE
GFS AND ECMWF PAINTING MODERATE QPF OVER THE CWFA THURSDAY
AFTERNOON. LIFTED INDICES -2 TO -4C ACROSS THE CWFA WITH -5 TO -6C
ACROSS THE PANHANDLE. ADDED THUNDERSTORM MENTION IN THE FORECAST
FOR THURSDAY AFTERNOON/EVENING.
FRIDAY COULD BE AN INTERESTING DAY THUNDERSTORM WISE AS A SURFACE
LOW DEVELOPS OVER NORTHEASTERN COLORADO. UPPER LEVEL LOW ALMOST
VERTICALLY STACKED OVER THE SURFACE LOW ON BOTH THE GFS AND
ECMWF. GFS MOST BULLISH ON QPF...WITH AN AREA OVER HEAVY RAIN OVER
THE SOUTHERN PANHANDLE. LOW SLOW TO MOVE OUT OF THE AREA WITH
SHOWER ACTIVITY CONTINUING INTO SATURDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1238 AM MDT TUE APR 21 2015
VFR CONDITIONS WILL PREVAIL OVERNIGHT WITH SCATTERED HIGH CLOUDS
OVER SOUTHEAST WY. AREAS OF IFR-LIFR CONDITIONS IN FOG WILL BE
POSSIBLE ACROSS THE LARAMIE VALLEY INCLUDING KLAR BETWEEN 10Z AND
14Z TUESDAY. OTHERWISE...SCATTERED TO BROKEN MID AND HIGH CLOUDS
ARE EXPECTED DURING THE DAY. IT WILL BE BREEZY TUESDAY AS WEST TO
NORTHWEST WINDS GUST BETWEEN 25 AND 30 KT...EXCEPT FOR VALLEY
LOCATIONS.
&&
.FIRE WEATHER...
ISSUED AT 250 PM MDT MON APR 20 2015
RECENT RAIN AND CONTINUED SNOW PACK FROM LAST WEEKS STORM WILL
KEEP FIRE WEATHER CONCERNS MINIMAL THROUGH THE WEEK. GOING TO SEE
INCREASED CHANCES FOR WETTING RAINS AND MOUNTAIN SNOWS LATE IN THE
WEEK AS ANOTHER PACIFIC LOW PRESSURE SYSTEM TRACKS ACROSS NORTHERN
COLORADO.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...RJM
SHORT TERM...RUBIN
LONG TERM...GCC
AVIATION...MJ
FIRE WEATHER...GCC
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1013 AM CDT TUE APR 21 2015
.UPDATE...
ISSUED AT 1012 AM CDT TUE APR 21 2015
MAIN FORECAST CONCERN WILL BE WITH THE WINDS TODAY. ALREADY
STARTING TO SEE WIND GUSTS TO AROUND 30 MPH ACROSS THE NORTHERN
CWA. LATEST HRRR AND RAP DATA SUGGESTING A PERIOD OF 40-45 KNOTS
FOR A FEW HOURS EARLY THIS AFTERNOON ACROSS MAINLY AREAS ALONG AND
NORTH OF I-74...ALTHOUGH THEY ARE ALSO NOW SUGGESTING THIS AS FAR
SOUTH AS THE I-70 CORRIDOR. HAVE NOT GONE THAT HIGH SO FAR SOUTH
AS CLOUDS THERE WILL BE ON THE INCREASE AND PREVENT FULL MIXING...
BUT RAISED THE WIND GUSTS A TAD OVER THE NORTH AS MOSTLY SUNNY
CONDITIONS CONTINUE INTO AT LEAST MID AFTERNOON.
&&
.SHORT TERM...(TODAY)
ISSUED AT 323 AM CDT TUE APR 21 2015
WINDY CONDITIONS WILL ONCE AGAIN DEVELOP ACROSS CENTRAL ILLINOIS
TODAY, THANKS TO A TIGHTENING PRESSURE GRADIENT AND DEEP-LAYER
MIXING. THE STRONGEST WINDS WILL BE FOCUSED ALONG/NORTH OF THE I-74
CORRIDOR, WHERE FORECAST SOUNDINGS SUGGEST SUSTAINED WINDS OF AROUND
30MPH WITH GUSTS UP TO 40MPH AT TIMES. WILL THEREFORE ISSUE A
WIND ADVISORY FOR THIS AREA FROM 11AM TO 7PM. FURTHER SOUTH
ACROSS THE REMAINDER OF THE KILX CWA, WINDS WILL REMAIN BELOW
ADVISORY CRITERIA, MAINLY IN THE 25 TO 30MPH RANGE. SKIES WILL
BE MOSTLY SUNNY THROUGH MUCH OF THE DAY, WITH AN INCREASE IN
CLOUDS NOTED ACROSS THE FAR SOUTH DURING THE AFTERNOON AS A
MID-LEVEL SHORT-WAVE APPROACHES FROM THE WEST. ALL MODELS ARE
DEVELOPING SCATTERED SHOWERS/THUNDER IN ADVANCE OF THIS WAVE, BUT
PRIMARILY KEEP THE ACTIVITY JUST SOUTH OF THE CWA. HIGHER-RES
MODELS SUCH AS THE HRRR ARE SLIGHTLY FURTHER NORTH, SO HAVE OPTED
TO INCLUDE SLIGHT CHANCE POPS FOR SHOWERS SOUTH OF I-70 THIS
AFTERNOON. THANKS TO INCREASED SUNSHINE, HIGH TEMPERATURES WILL
BE A FEW DEGREES WARMER THAN YESTERDAY, WITH READINGS CLIMBING
INTO THE LOWER TO MIDDLE 60S.
.LONG TERM...(TONIGHT THROUGH MONDAY)
ISSUED AT 323 AM CDT TUE APR 21 2015
MAIN CHALLENGES IN THE EXTENDED CONTINUE TO BE FROST POTENTIAL
WEDNESDAY/THURSDAY NIGHTS, AS WELL AS, TIMING OF NEXT PRECIP EVENT
BY THE END OF THE WEEK.
DEEP UPPER LOW CURRENTLY CENTERED OVER THE WESTERN GREAT LAKES WILL
BE THE DOMINANT WEATHER FEATURE ACROSS THE MIDWEST FOR THE NEXT FEW
DAYS, RESULTING IN COOL CONDITIONS THROUGH FRIDAY. AS A PIECE OF
ENERGY ROTATES AROUND THE LOW, A WEAK COLD FRONT WILL DROP THROUGH
ILLINOIS TONIGHT. FORECAST SOUNDINGS ARE INITIALLY QUITE DRY:
HOWEVER, THE LATEST MODELS SHOW QUITE A BIT MORE TOP-DOWN MOISTENING
THAN IN PREVIOUS RUNS. AS A RESULT, THINK SCATTERED LIGHT SHOWERS
WILL ACCOMPANY THE FRONT TONIGHT, WITH PERHAPS A FEW SHOWERS
LINGERING INTO WEDNESDAY MORNING ACROSS THE FAR SE. ONCE THE
FRONT EXITS, CANADIAN HIGH PRESSURE WILL BUILD INTO THE REGION FOR
THE MIDDLE AND END OF THE WEEK. THE RIDGE AXIS IS PROGGED TO BE
JUST WEST OF THE MISSISSIPPI RIVER BY 12Z THURSDAY, SO AM
EXPECTING WINDS TO DIMINISH CONSIDERABLY AS THE PRESSURE GRADIENT
WEAKENS. WITH CLEAR SKIES AND LIGHT WINDS, OVERNIGHT LOWS WILL
DIP INTO THE LOWER TO MIDDLE 30S, LEADING TO FROST DEVELOPMENT
ACROSS MUCH OF THE AREA. IF SKIES REMAIN CLEAR, ANOTHER
POTENTIALLY FROSTY NIGHT WILL OCCUR THURSDAY NIGHT AS WELL.
FURTHER OUT, MODELS ARE HAVING CONSIDERABLE DIFFICULTY PINNING DOWN
THE END OF THE WEEK SYSTEM. SOLUTIONS HAVE BEEN FLIP-FLOPPING FROM
RUN TO RUN, SO OVERALL FORECAST CONFIDENCE BEYOND THURSDAY REMAINS
LOWS. THE 00Z APR 21 GFS HAS MADE A MAJOR SHIFT BACK TO A SOLUTION
IT FEATURED A COUPLE OF DAYS AGO. MEANWHILE, BOTH THE ECMWF AND GEM
SEEM TO BE HEADING IN THE OPPOSITE DIRECTION. GIVEN SO MUCH MODEL
INCONSISTENCY, PREFER TO MAKE VERY FEW CHANGES TO THE EXTENDED.
WITH CANADIAN HIGH PRESSURE INITIALLY IN PLACE ACROSS THE MIDWEST ON
WEDNESDAY/THURSDAY, STILL THINK A SLOWER ARRIVAL OF THE NEXT STORM
SYSTEM MAKES SENSE. AS A RESULT, HAVE KEPT FRIDAY DRY DESPITE WHAT
THE ECMWF AND GEM ARE ADVERTISING. HAVE INTRODUCED POPS FRIDAY
NIGHT INTO SATURDAY AS A SYSTEM OVER THE DESERT SOUTHWEST GETS
KICKED EASTWARD. STILL QUITE A BIT OF UNCERTAINTY CONCERNING HOW
FAR NORTH PRECIP WILL SPREAD, BUT HAVE STUCK WITH PREVIOUS THINKING
OF KEEPING HIGHEST POPS FOCUSED ACROSS THE SOUTHERN HALF OF THE CWA.
THIS IS IN GOOD AGREEMENT WITH THE LATEST GFS, BUT NOT THE ECMWF/GEM
WHICH BOTH FOCUS PRECIP MUCH FURTHER NORTH. ONCE THE SYSTEM EXITS,
A RETURN TO DRY WEATHER IS ANTICIPATED FOR SUNDAY BEFORE ANOTHER
FAST-MOVING NORTHERN-STREAM WAVE POTENTIALLY BRINGS A FEW SHOWERS
BACK INTO THE PICTURE BY MONDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 634 AM CDT TUE APR 21 2015
VFR CONDITIONS WILL PREVAIL AT ALL TAF SITES NEXT 24HRS. CLEAR
SKIES WILL GIVE WAY TO SCATTERED MID CLOUDS ADVECTING THROUGH THE
AREA THIS MORNING AND INTO THIS AFTERNOON. HEIGHT OF CLOUDS WILL
LOWER TO AROUND 8KFT LATER THIS EVENING JUST AHEAD OF A WEAK COLD
FRONT EXPECTED TO MOVE THROUGH THE AREA TONIGHT. BELIEVE LOWER
LAYERS WILL BE TOO DRY FOR PCPN AT FIRST, BUT THINKING SHOWERS
WILL BE POSSIBLE IN CONJUNCTION WITH THE FRONT BEGINNING LATE IN
THE EVENING AND CONTINUING INTO THE OVERNIGHT HOURS. CIGS MAY
LOWER INTO MVFR RANGES WITH PCPN, BUT NOT CONFIDENT WITH THIS,
SO WILL KEEP CIGS IN VFR RANGES. PCPN WILL LIKELY END BEFORE
SUNRISE. WEST WINDS WILL BECOME QUITE GUSTY AGAIN TODAY AND SHOULD
GET UP TO 30-35KTS DURING THE AFTERNOON. AFTER SUNSET WINDS WILL
TAPER OFF BUT STILL LOOKING AT 11-13KTS DURING THE EVENING. AS THE
FRONT MOVES THROUGH AROUND MIDNIGHT, WINDS WILL BECOME
NORTHWESTERLY AND STILL OVER 10KTS.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR ILZ027>031-037-038-
043>046.
&&
$$
UPDATE...GEELHART
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS LINCOLN IL
634 AM CDT TUE APR 21 2015
.SHORT TERM...(TODAY)
ISSUED AT 323 AM CDT TUE APR 21 2015
WINDY CONDITIONS WILL ONCE AGAIN DEVELOP ACROSS CENTRAL ILLINOIS
TODAY, THANKS TO A TIGHTENING PRESSURE GRADIENT AND DEEP-LAYER
MIXING. THE STRONGEST WINDS WILL BE FOCUSED ALONG/NORTH OF THE I-74
CORRIDOR, WHERE FORECAST SOUNDINGS SUGGEST SUSTAINED WINDS OF AROUND
30MPH WITH GUSTS UP TO 40MPH AT TIMES. WILL THEREFORE ISSUE A
WIND ADVISORY FOR THIS AREA FROM 11AM TO 7PM. FURTHER SOUTH
ACROSS THE REMAINDER OF THE KILX CWA, WINDS WILL REMAIN BELOW
ADVISORY CRITERIA, MAINLY IN THE 25 TO 30MPH RANGE. SKIES WILL
BE MOSTLY SUNNY THROUGH MUCH OF THE DAY, WITH AN INCREASE IN
CLOUDS NOTED ACROSS THE FAR SOUTH DURING THE AFTERNOON AS A
MID-LEVEL SHORT-WAVE APPROACHES FROM THE WEST. ALL MODELS ARE
DEVELOPING SCATTERED SHOWERS/THUNDER IN ADVANCE OF THIS WAVE, BUT
PRIMARILY KEEP THE ACTIVITY JUST SOUTH OF THE CWA. HIGHER-RES
MODELS SUCH AS THE HRRR ARE SLIGHTLY FURTHER NORTH, SO HAVE OPTED
TO INCLUDE SLIGHT CHANCE POPS FOR SHOWERS SOUTH OF I-70 THIS
AFTERNOON. THANKS TO INCREASED SUNSHINE, HIGH TEMPERATURES WILL
BE A FEW DEGREES WARMER THAN YESTERDAY, WITH READINGS CLIMBING
INTO THE LOWER TO MIDDLE 60S.
.LONG TERM...(TONIGHT THROUGH MONDAY)
ISSUED AT 323 AM CDT TUE APR 21 2015
MAIN CHALLENGES IN THE EXTENDED CONTINUE TO BE FROST POTENTIAL
WEDNESDAY/THURSDAY NIGHTS, AS WELL AS, TIMING OF NEXT PRECIP EVENT
BY THE END OF THE WEEK.
DEEP UPPER LOW CURRENTLY CENTERED OVER THE WESTERN GREAT LAKES WILL
BE THE DOMINANT WEATHER FEATURE ACROSS THE MIDWEST FOR THE NEXT FEW
DAYS, RESULTING IN COOL CONDITIONS THROUGH FRIDAY. AS A PIECE OF
ENERGY ROTATES AROUND THE LOW, A WEAK COLD FRONT WILL DROP THROUGH
ILLINOIS TONIGHT. FORECAST SOUNDINGS ARE INITIALLY QUITE DRY:
HOWEVER, THE LATEST MODELS SHOW QUITE A BIT MORE TOP-DOWN MOISTENING
THAN IN PREVIOUS RUNS. AS A RESULT, THINK SCATTERED LIGHT SHOWERS
WILL ACCOMPANY THE FRONT TONIGHT, WITH PERHAPS A FEW SHOWERS
LINGERING INTO WEDNESDAY MORNING ACROSS THE FAR SE. ONCE THE
FRONT EXITS, CANADIAN HIGH PRESSURE WILL BUILD INTO THE REGION FOR
THE MIDDLE AND END OF THE WEEK. THE RIDGE AXIS IS PROGGED TO BE
JUST WEST OF THE MISSISSIPPI RIVER BY 12Z THURSDAY, SO AM
EXPECTING WINDS TO DIMINISH CONSIDERABLY AS THE PRESSURE GRADIENT
WEAKENS. WITH CLEAR SKIES AND LIGHT WINDS, OVERNIGHT LOWS WILL
DIP INTO THE LOWER TO MIDDLE 30S, LEADING TO FROST DEVELOPMENT
ACROSS MUCH OF THE AREA. IF SKIES REMAIN CLEAR, ANOTHER
POTENTIALLY FROSTY NIGHT WILL OCCUR THURSDAY NIGHT AS WELL.
FURTHER OUT, MODELS ARE HAVING CONSIDERABLE DIFFICULTY PINNING DOWN
THE END OF THE WEEK SYSTEM. SOLUTIONS HAVE BEEN FLIP-FLOPPING FROM
RUN TO RUN, SO OVERALL FORECAST CONFIDENCE BEYOND THURSDAY REMAINS
LOWS. THE 00Z APR 21 GFS HAS MADE A MAJOR SHIFT BACK TO A SOLUTION
IT FEATURED A COUPLE OF DAYS AGO. MEANWHILE, BOTH THE ECMWF AND GEM
SEEM TO BE HEADING IN THE OPPOSITE DIRECTION. GIVEN SO MUCH MODEL
INCONSISTENCY, PREFER TO MAKE VERY FEW CHANGES TO THE EXTENDED.
WITH CANADIAN HIGH PRESSURE INITIALLY IN PLACE ACROSS THE MIDWEST ON
WEDNESDAY/THURSDAY, STILL THINK A SLOWER ARRIVAL OF THE NEXT STORM
SYSTEM MAKES SENSE. AS A RESULT, HAVE KEPT FRIDAY DRY DESPITE WHAT
THE ECMWF AND GEM ARE ADVERTISING. HAVE INTRODUCED POPS FRIDAY
NIGHT INTO SATURDAY AS A SYSTEM OVER THE DESERT SOUTHWEST GETS
KICKED EASTWARD. STILL QUITE A BIT OF UNCERTAINTY CONCERNING HOW
FAR NORTH PRECIP WILL SPREAD, BUT HAVE STUCK WITH PREVIOUS THINKING
OF KEEPING HIGHEST POPS FOCUSED ACROSS THE SOUTHERN HALF OF THE CWA.
THIS IS IN GOOD AGREEMENT WITH THE LATEST GFS, BUT NOT THE ECMWF/GEM
WHICH BOTH FOCUS PRECIP MUCH FURTHER NORTH. ONCE THE SYSTEM EXITS,
A RETURN TO DRY WEATHER IS ANTICIPATED FOR SUNDAY BEFORE ANOTHER
FAST-MOVING NORTHERN-STREAM WAVE POTENTIALLY BRINGS A FEW SHOWERS
BACK INTO THE PICTURE BY MONDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 634 AM CDT TUE APR 21 2015
VFR CONDITIONS WILL PREVAIL AT ALL TAF SITES NEXT 24HRS. CLEAR
SKIES WILL GIVE WAY TO SCATTERED MID CLOUDS ADVECTING THROUGH THE
AREA THIS MORNING AND INTO THIS AFTERNOON. HEIGHT OF CLOUDS WILL
LOWER TO AROUND 8KFT LATER THIS EVENING JUST AHEAD OF A WEAK COLD
FRONT EXPECTED TO MOVE THROUGH THE AREA TONIGHT. BELIEVE LOWER
LAYERS WILL BE TOO DRY FOR PCPN AT FIRST, BUT THINKING SHOWERS
WILL BE POSSIBLE IN CONJUNCTION WITH THE FRONT BEGINNING LATE IN
THE EVENING AND CONTINUING INTO THE OVERNIGHT HOURS. CIGS MAY
LOWER INTO MVFR RANGES WITH PCPN, BUT NOT CONFIDENT WITH THIS,
SO WILL KEEP CIGS IN VFR RANGES. PCPN WILL LIKELY END BEFORE
SUNRISE. WEST WINDS WILL BECOME QUITE GUSTY AGAIN TODAY AND SHOULD
GET UP TO 30-35KTS DURING THE AFTERNOON. AFTER SUNSET WINDS WILL
TAPER OFF BUT STILL LOOKING AT 11-13KTS DURING THE EVENING. AS THE
FRONT MOVES THROUGH AROUND MIDNIGHT, WINDS WILL BECOME
NORTHWESTERLY AND STILL OVER 10KTS.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 11 AM THIS MORNING TO 7 PM CDT THIS EVENING
FOR ILZ027>031-037-038-043>046.
&&
$$
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS TOPEKA KS
649 AM CDT Tue Apr 21 2015
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 300 AM CDT TUE APR 21 2015
Deep upper low over the Great Lakes was making slow eastward
progress early this morning with likely a few small scale waves
rotating around it through the Northern and Central Plains. Periodic
mid cloud was present over the local area via isentropic upglide
from rather brisk and backed mid level winds. At least minor amounts
of EPV along the moist layer allowing some showers to form aloft,
with weak returns on radar showing some very light precip reaching
to the lower troposphere. HRRR and RAP runs quite similar to some
4km WRF runs with light precip forming over central Kansas in the
next few hours, with latest IR imagery indicating recent cloud
development there. All nearby 0Z soundings measured 850mb dewpoint
depressions around 12C, making measurable amounts hard to imagine in
this activity. A somewhat more unstable airmass develops over the
southeast quarter of Kansas this afternoon with weak surface
convergence. Will maintain small storm chances with still minor
isentropic lift and weak wave potential in place. The stronger wind
fields aloft could lead to some storm organization along with CAPE
around 500 J/kg and dry adiabatic low level lapse rates to produce a
very small threat for severe wind and hail in the mid afternoon to
early evening. Areas outside of storms could also see a few rather
strong wind gusts with mixing depths reaching 7000-10000ft AGL
though some veering remains through the column. The still dry
airmass and gusty winds lead to elevated fire danger in western
locations this afternoon.
Cold front via a stronger wave rotating around the low arrives this
evening and makes quick south progress through the state tonight.
Moisture, though modest, will continue to pool ahead of this front
for some storm chances through much of the night in the southern
zones, with typical diurnal trends allowing severe concerns to
diminish. Models are allowing the boundary layer to decouple fairly
quickly behind the front, but am somewhat skeptical of this given
the baroclinic zone they advertise. If winds can fall quicker than
expected, fairly clear skies could present a frost concern, but even
if they do the window of cold and calm conditions for formation
should be rather limited. Will mention patchy frost in far north
where concern is highest.
.LONG TERM...(Wednesday through Monday)
Issued at 300 AM CDT TUE APR 21 2015
Eastern Kansas remains on the southwest side of an upper surface
high for Wednesday, keeping high temperatures around 60 for most
of the area. Have kept rain chances out of the southern areas with
better chances south. Dry conditions continue Wednesday night into
Thursday, with lows in the upper 30s to near 40 and highs climbing
toward the middle 60s Thursday.
Upper pattern starts to shift Thursday night as shortwave ridge
noses out of the southern plains into our area, ahead of an upper
trof lifting northeast out of the four corners region. Initial
sensible weather impacts should be warmer lows in the 40s near 50
Thursday night with some showers possible after midnight as low
level jet makes a return over the area. Latest EC appears to be
trending toward the GFS solution for this shortwave as it moves
into the plains, taking a faster track and developing the warm
front from the surface low out into eastern or southeast Kansas.
GFS keeps the boundary south of the area and would make for cloudy
cool and rainy conditions area wide for Friday and Saturday night,
and with EC solutions also trending this way, have gone with
forecast as such.
Southern branch of the upper jet takes the shortwave trof east of
the area rather quickly on Saturday, with rain ending sometime
during the morning hours. Cooler high pressure once again noses
into the area behind the departing low and holds temperatures in
the low 60s, followed by overnight lows in the 40s. Highs on
Sunday rise a bit more into the middle 60s, and have kept rain
chances relegated to north and west while surface high continues
over the east. Another front progged to move across the area
Sunday night with northwest flow aloft returning on Monday.
Current forecast is for highs near 70, but this will depend on how
strong the front and wave are as to how much cooler air it does,
or does not, bring southward.
&&
.AVIATION...(For the 12Z TAFs through 12Z Wednesday Morning)
Issued at 649 AM CDT TUE APR 21 2015
VFR conditions anticipated. Periods of mid cloud should dominate
with a small chance for -SHRA through much of the forecast, though
still of high-based variety. Wind gusts could push beyond forecast
parameters a few times in very deep mixing from 20Z-00Z but should
be exception. Cold front passage brings wind shift around 04Z.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...65
LONG TERM...67
AVIATION...65
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
632 AM CDT TUE APR 21 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM CDT TUE APR 21 2015
AN ARCTIC COLD FRONT ACROSS NORTH DAKOTA WILL BACK INTO THE FCST
AREA THIS AFTN PRODUCING SOME CLOUDINESS. THE FRONT WILL CONTINUE
TO MOVE SOUTH AND WEST TONIGHT. BY 12Z WEDNESDAY A SMALL AREA OF
HIGH PRESSURE HAS SETTLED OVER NCNTL NEB WHICH SHOULD PRODUCE
LOWS IN THE 20S. BY THIS TIME...THE MODELS SUGGEST ANY CLOUD
COVER WOULD LIE ACROSS THE PANHANDLE AND SOUTHWEST NEB WHICH
WOULD HOLD UP LOWS IN THE LOWER 30S.
HIGHS TODAY RISE INTO THE 60S AHEAD OF THE FRONT WITH 50S NORTH
OF THE FRONT ALONG HIGHWAY 20.
THE MIDLEVEL CLOUD COVER ACROSS CNTL/SERN NEB EARLY THIS MORNING
IS ASSOCIATED WITH 700MB FRONTOGENESIS. THE RAP MOVES THESE
CLOUDS SOUTHEAST AND THEN DROPS A SECOND BATCH OF CLOUDS INTO NRN
NEB AS EARLY AS 15Z WHICH HANG AROUND MOST OF THE DAY AND THEN
MOVE SOUTH AND WEST TONIGHT. THE RADAR RETURNS ACROSS NORTH
DAKOTA MOVE EAST OF THE FCST AREA IN THE NAM MODEL WHILE THE HRRR
SHOWS TOO MUCH DRY AIR IN THE LOWER LEVELS FOR ANYTHING MORE THAN
SPRINKLES THIS AFTN AND TONIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 355 AM CDT TUE APR 21 2015
SURFACE HIGH PRESSURE QUICKLY FOLLOWS THE COLD FRONT AND WILL
SLIDE SOUTHEAST OF THE AREA EARLY IN THE DAY ON WEDNESDAY WITH
SOUTHERLY WINDS DEVELOPING. DESPITE SOUTHERLY WINDS...COOL AIR
ALOFT...850 TEMP FROM 3C EAST TO 8C WEST...AND EVEN WITH SUN AND
GOOD MIXING...HIGHS IN THE UPPER 50S AND LOWER 60S. MEANWHILE AN
UPPER LEVEL LOW LIFTS TOWARDS THE DESERT SW. MODELS ALSO SHOW A
WEAK SYSTEM AHEAD OF THE MAIN LOW...PUSHING ACROSS THE SOUTHERN
PLAINS.
A SECOND WAVE EJECTS FROM THE MAIN LOW AND ARRIVES TO THE
SOUTHERN/CENTRAL PLAINS WED NIGHT INTO THURSDAY. MARGINAL LIFT
INTO SW NEB MAY RESULT IN A FEW LIGHT SHOWERS INITIALLY. A BETTER
CHANCE ARRIVES LATER IN THE DAY ON THURSDAY AFTER WE GET SOME
HEATING. MODELS INCREASE CAPES TO A FEW 100 J/KG AND LIFTED INDEX
VALUES AROUND ZERO OR SLIGHTLY NEG. GENERALLY THING ACTIVITY WILL
BE SOME SHOWERS AND A FEW RUMBLES OF THUNDER HERE OR THERE.
BY FRIDAY THE MAIN LOW WILL BE CROSSING THE ROCKIES. MOISTURE
CONTINUES TO INCREASE AHEAD OF THE LOW AND FRIDAY LOOKS TO SEE A
WAVE OR TWO OF SHOWERS TO ROTATE THROUGH THE AREA. BETTER
MOISTURE LIFT ASSOCIATED CLOSER TO THE LOW...WHICH FAVORS HIGHER
POPS ACROSS SW NEB.
A SECOND WAVE...CLIPPER...QUICKLY FOLLOWS FOR THE WEEKEND. SHOULD
SEE A BRIEF BREAK IN THE ACTIVITY BEFORE THE SECOND WAVE
ARRIVES...ALTHOUGH TIMING THE BREAK IS DIFFICULT DUE TO MODEL
DIFFERENCES. FORECAST DOES RETAIN LOW POPS AND EXPECT THIS TO
CHANGE IN THE COMING DAYS AS THE LULL IN ACTIVITY BECOMES MORE
CLEAR. AT THIS TIME MODELS ARE IN FAVOR OF THE DRY PERIOD TO
OCCUR SOMETIME SATURDAY...EARLIEST IS THE GEM/GFS...WHILE LATER
IS FAVORED BY THE ECMWF.
THE NEXT WAVE SHOULD BE EAST OF THE AREA TO START THE WORK WEEK
DRY AND MILD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 630 AM CDT TUE APR 21 2015
THE MID LEVEL CLOUDS ACROSS SD WILL SPREAD SOUTH THROUGH THE
FORECAST AREA TODAY AND EXIT SOUTH AND WEST TONIGHT. VFR IS
EXPECTED ALL AREAS DURING THIS TIME.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS RALEIGH NC
955 AM EDT TUE APR 21 2015
.SYNOPSIS...HIGH PRESSURE WILL BUILD OVER NC FROM THE SOUTHWEST
TODAY AND TONIGHT... THEN SHIFT EAST OFF THE COAST TUESDAY NIGHT
INTO WEDNESDAY. A DRY COLD FRONT WILL APPROACH FROM THE NORTH
WEDNESDAY NIGHT AND PUSH SOUTH OF THE REGION THURSDAY.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 955 AM TUESDAY...
THE LATEST SURFACE ANALYSIS SHOWED THE COLD FRONT OFFSHORE WITH A
WEAK SURFACE TROUGH TOWARD THE MOUNTAINS. DRY AIR WAS NOTED ON THE
LATEST WATER VAPOR IMAGES...AND ALSO SHOWN ON UPPER-AIR ANALYSES AND
THE KGSO 12Z SOUNDING. WINDS ALOFT WERE STRONGER THAN FORECAST BY
GUIDANCE...AND THIS SHOULD TRANSLATE INTO SOME SURFACE WIND GUSTS AT
LEAST AROUND 20KT BASED ON THE LATEST RAP SOUNDINGS...POSSIBLY
BRIEFLY TO 25KT IN A FEW SPOTS. OUTSIDE OF FEW-TO-SCATTERED CU
TOWARD THE TRIAD ON THE LATEST VISIBLE SATELLITE IMAGES...RAP
SOUNDINGS SUGGEST CONSIDERABLE SUNSHINE THROUGHOUT CENTRAL NORTH
CAROLINA. SURFACE DEW POINTS HAD FALLEN QUICKLY AND LEANED TOWARD
THE LOWER DEW POINT OF THE RAP MODEL THIS AFTERNOON AS A RESULT...
MAKING FOR SOME MINIMUM RELATIVE HUMIDITIES IN THE 20S PERCENT
PARTICULARLY OVER THE NORTHWEST PIEDMONT. RECENT RAIN AND WET GROUND
SHOULD KEEP FIRE WEATHER CONCERNS LOW. 1000-850MB THICKNESSES AND
GOOD MIXING PROVIDE FOR EXPECTED HIGHS AS CURRENTLY FORECAST...
LEANING TOWARD THE WARMER MET MOS GUIDANCE FOR HIGHS PRIMARILY 69 TO
74.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY/...
AS OF 1240 AM TUESDAY...
CLEAR AND COOL CONDITIONS EXPECTED TONIGHT. LOWS IN THE MID 40S WITH
LIGHT WINDS.
WEDNESDAY... THE MAIN ISSUE WILL BE THE EXPECTED GUSTY RETURN FLOW
DEVELOPING LATE MORNING THROUGH THE AFTERNOON FROM THE SW. WINDS
SHOULD INCREASE TO 15-20 MPH WITH GUSTS TO 30 MPH OUT AHEAD OF THE
APPROACHING DRY COLD FRONT. HIGHS WILL WARM INTO THE MID TO UPPER
70S WITH PARTLY SUNNY SKIES.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
AS OF 1212 AM TUESDAY...
A MOISTURE STARVED COLD FRONT IS EXPECTED TO PUSH SOUTH THROUGH
CENTRAL NORTH CAROLINA WEDNESDAY NIGHT... THEN STALL WELL SOUTH OVER
SOUTH CAROLINA THURSDAY INTO FRIDAY. THE MAIN MOISTURE SOURCES ARE
FORECAST TO BE CUT OFF AS THIS FRONT MOVES THROUGH WEDNESDAY NIGHT.
WEAK HIGH PRESSURE WILL BUILD SOUTHEAST FROM THE OHIO VALLEY INTO
NORTH CAROLINA LATER THURSDAY INTO FRIDAY. SENSIBLE WEATHER
WEDNESDAY NIGHT WILL FEATURE ONLY A CHANCE OF A SPRINKLE OR TWO OR A
VERY LIGHT SHOWER WITH THE FRONT. LOWS GENERALLY FROM 50 NORTH INTO
THE UPPER 50S SOUTH. MOSTLY SUNNY SKIES THURSDAY WILL GIVE WAY TO
SOME INCREASE IN MID AND HIGH CLOUDS IN THE WEST AND SOUTH FRIDAY.
HIGHS BOTH DAYS SHOULD BE AROUND 70 INTO THE LOWER 70S SOUTH. LOWS
THURSDAY NIGHT GENERALLY IN THE 40S.
SATURDAY THROUGH MONDAY... THE BEST CHANCE OF RAIN IS EXPECTED TO BE
SATURDAY INTO SUNDAY AS THE ACTIVE SOUTHERN BRANCH JET SYSTEM TRACKS
ACROSS THE LOWER MISSISSIPPI VALLEY TOWARD THE SOUTHEASTERN STATES.
UNCERTAINTY WITHIN THE MODELS CONTINUE WITH THE TIMING/STRENGTH/
AND TRACK WITH THE SYSTEM. MODELS CONTINUE TO SHOW A DEEP TROUGH
OVER SE CANADA AND THE EASTERN STATES AS WELL WHICH WILL ESSENTIALLY
GUARANTEE BELOW NORMAL LATE APRIL TEMPERATURES THIS WEEKEND INTO
NEXT WEEK. THE BIG QUESTION WILL BE HOW MUCH RAIN WILL FALL OVER THE
WEEKEND WITH THE SOUTHERN BRANCH SYSTEM. WE WILL MAINTAIN CHANCE POP
WITH INCREASING CONFIDENCE FOR THE WEEKEND.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
AS OF 650 AM TUESDAY...
VFR CONDITIONS ARE NOW EXPECTED THROUGH THURSDAY OR FRIDAY.
SUB-VFR CONDITIONS ARE EXPECTED TO DEVELOP WITH RAIN BY SATURDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BADGETT
NEAR TERM...DJF
SHORT TERM...BADGETT
LONG TERM...BADGETT
AVIATION...BADGETT
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
644 AM EDT TUE APR 21 2015
.SYNOPSIS...
A STRONG LOW PRESSURE SYSTEM OVER THE GREAT LAKES WILL BRING VERY
WINDY CONDITIONS TODAY...ALONG WITH A CHANCE OF SHOWERS AT TIMES
THROUGH WEDNESDAY MORNING. DRIER CONDITIONS ARE EXPECTED FROM
WEDNESDAY AFTERNOON THROUGH THE REST OF THE WEEK...WITH BREEZY
AFTERNOONS AND COOL TEMPERATURES. ANOTHER CHANCE OF RAIN WILL ARRIVE
ON SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SCATTERED TO BROKEN CLOUDS IN THE 6KFT-10KFT LAYER ARE CROSSING
THE ILN CWA FROM WEST TO EAST...DELINEATED VERY NICELY ON IR
SATELLITE. WITHIN THESE PATCHES OF CLOUDS ARE SOME
CONVECTIVE-LOOKING SHOWERS...AND ALTHOUGH NO LIGHTNING HAS BEEN
OBSERVED...PEA SIZE HAIL WAS OBSERVED WITH ONE OF THE SHOWERS
(THANKS TO THE FREEZING LEVELS OF AROUND 4KFT).
THE PRIMARY CONCERN TODAY REMAINS THE THREAT FOR STRONG
WINDS...AND AN ANALYSIS OF 00Z MODEL DATA SUPPORTED MAINTAINING
THE CURRENT ORIENTATION FOR THE WIND ADVISORY (WITH A SPECIAL
WEATHER STATEMENT FOR THE REST OF THE FORECAST AREA). STRONG
UNIDIRECTIONAL FLOW (AT ABOUT 250 DEGREES) EXTENDS THROUGH THE
ENTIRE DEPTH OF THE TROPOSPHERE...WITH VALUES STEADILY INCREASING
OFF THE SURFACE. USING A RECENT RAP RUN AT KDAY ON BUFKIT AS AN
EXAMPLE (AT 18Z)...WINDS INCREASE TO 40 KNOTS AT 825MB...THEN 50
KNOTS AT 700MB...AND 60 KNOTS AT 600MB. TODAY WILL BE AN EXERCISE
IN MIXING...AS THE EVENTUAL DEPTH OF THE MIXED LAYER WILL LIKELY
DETERMINE JUST HOW STRONG THE WINDS GET. GUSTS IN THIS FORECAST
WERE GENERALLY GLEANED FROM BUFKIT MOMENTUM TRANSFER VIA RAP/GFS
FORECASTS...WITH VALUES IN THE LOWER 40 KNOT RANGE IN THE NORTHERN
CWA...AND LOWER 30 KNOT RANGE IN THE SOUTHERN CWA.
ALTHOUGH CLEAR SKIES WILL BE IN PLACE AT THE BEGINNING OF THE
DAY...WEAK ELEVATED FORCING AND A SLIGHT INCREASE IN MOISTURE AT
THE TOP OF THE (RATHER HIGH) MIXED LAYER WILL RESULT IN SOME CLOUD
DEVELOPMENT...AND EVENTUALLY SHOWERS IN THE SOUTHEASTERN HALF OF
THE FORECAST AREA. THESE SHOWERS MAY BE VERY HIGH-BASED (PERHAPS
8000 FEET)...WITH SCATTERED COVERAGE AT MOST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
PRECIPITATION IS EXPECTED TO MOVE INTO THE REGION (OR PERHAPS
DEVELOP OVER THE FORECAST AREA) ON TUESDAY NIGHT INTO WEDNESDAY
MORNING. ALTHOUGH THERE ARE SOME MODEL DIFFERENCES WITH REGARDS TO
THE INTENSITY AND LAYOUT OF THE PRECIPITATION...THE OVERALL TIMING
APPEARS TO FAVOR THE 06Z-15Z TIME FRAME FOR THE ILN FORECAST
AREA...AHEAD OF A SHORTWAVE AND A SURFACE COLD FRONT. ALTHOUGH
THIS FRONT SHOWS UP NICELY ON MSLP PLOTS...THE WIND SHIFT AND
CHANGE IN AIR MASS ARE NOT ESPECIALLY NOTABLE. INSTABILITY (EVEN
ELEVATED) WILL BE HARD TO COME BY...SO THOUGH THUNDER IS NOT AN
IMPOSSIBILITY WITH THIS SETUP...THE CHANCE SEEMS VERY LOW.
ONCE THIS FRONT PASSES...VERY SIMILAR CONDITIONS ARE EXPECTED FOR
THE REST OF THE WEEK...WITH NORTHWEST FLOW AND COOL WEATHER. OHIO
IS LIKELY TO REMAIN IN BETWEEN AREAS OF ENHANCED MOISTURE FROM THE
NORTHERN AND SOUTHERN STREAMS...LEADING TO GENERALLY SUNNY
CONDITIONS UNTIL FRIDAY NIGHT.
TEMPERATURES ON THURSDAY AND FRIDAY MORNING MAY BE COOL ENOUGH FOR
FROST...BUT MOISTURE AND WIND FORECASTS ARE NOT AS FAVORABLE.
THUS...FROST WILL NOT BE INCLUDED IN THE GRIDS OR HWO.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
SOME DEEPER MOISTURE WILL BE PULLED UP TOWARD OUR AREA ON
SATURDAY AHEAD OF SHORT WAVE ENERGY MOVING OUT OF THE ROCKIES.
WHILE THE BEST FORCING/MOISTURE ASSOCIATED WITH THIS WILL REMAIN
TO OUR SOUTH...SOME PCPN COULD SNEAK UP INTO AT LEAST SOUTHERN
PORTIONS OF OUR FA EARLY IN THE WEEKEND. THIS MAY ALSO ALLOW FOR A
SLIGHT MODIFICATION IN TEMPERATURES WITH HIGHS PUSHING INTO THE
UPPER 50S TO LOWER 60S BY THE END OF THE LONG TERM PERIOD.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
LARGE SCALE UPPER LEVEL LOW CENTERED OVER THE WESTERN GREAT LAKES
THIS MORNING WILL MOVE SLOWLY EAST THROUGH THE TAF PERIOD. EMBEDDED
DISTURBANCES ROTATING AROUND THE LOW WILL AFFECT OUR REGION FROM
TIME TO TIME.
FOR TODAY...STRONG SURFACE LOW PRESSURE WILL REMAIN NORTH OF THE
GREAT LAKES. MEANWHILE...A COLD FRONT WILL APPROACH THE REGION
FROM THE WEST. THE INCREASING SURFACE PRESSURE GRADIENT COMBINED
WITH DEEP MIXING WILL RESULT IN WINDY CONDITIONS FROM MID MORNING
INTO EARLY EVENING. WINDS WILL VEER FROM A SOUTHWEST TO A
WEST/SOUTHWEST DIRECTION WITH WIND GUSTS IN THE 30 TO 40 KNOT
RANGE. MODELS CONTINUE TO INDICATE THAT SOME MOISTURE IN THE LOW
TO MID LEVEL WILL DEVELOP/ADVECT NORTHEAST INTO THE REGION BY THIS
AFTERNOON. THIS CLOUD LAYER COULD BECOME CONVECTIVE ENOUGH TO
PRODUCE A FEW SPRINKLES OR LIGHT SHOWERS...MAINLY ALONG AND SOUTH
OF THE OHIO RIVER.
FOR TONIGHT...ONE OF THOSE EMBEDDED DISTURBANCES MENTIONED WILL
DIG SOUTHEAST INTO OUR AREA. THIS FEATURE WILL TEAM UP WITH
FRONTAL CONVERGENCE FROM THE ADVANCING COLD FRONT TO BRING A
THREAT OF SHOWERS TO THE TAF SITES BETWEEN 06Z AND 12Z. THERE
COULD BE SOME POCKETS OF MVFR VISIBILITIES ASSOCIATED WITH THE
MORE ROBUST SHOWERS.
OUTLOOK...GUSTY WEST TO NORTHWEST WINDS UP TO 30 KNOTS EXPECTED
WEDNESDAY AFTERNOON INTO EARLY EVENING.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...WIND ADVISORY FROM 11 AM THIS MORNING TO 8 PM EDT THIS EVENING
FOR OHZ026-034-035-042>046-051>056-060>062.
KY...NONE.
IN...WIND ADVISORY FROM 11 AM THIS MORNING TO 8 PM EDT THIS EVENING
FOR INZ050.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...HATZOS
SHORT TERM...HATZOS
LONG TERM...JGL
AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS NORMAN OK
645 AM CDT TUE APR 21 2015
.DISCUSSION...
AVIATION DISCUSSION FOR THE 12Z TAFS IS BELOW.
&&
.AVIATION...
THINK VFR CONDITIONS WILL MAINLY PREVAIL.
ISO-SCT -SHRA WILL BE EAST OF KPNC-KOKC-KDUC BY 15Z.
ISO-SCT TSRA WILL LIKELY DEVELOP OVER WESTERN OKLAHOMA AFTER
06Z...THUS ADDED VCTS AT TAF SITES IN THESE AREAS. BRIEF VARIABLE
GUSTY WINDS...GS...AND MVFR OR LOWER CONDITIONS MAY BE POSSIBLE
WITH TSRA.
FAIRLY LIGHT SURFACE WINDS WILL SHIFT TO THE NORTH TO NORTHEAST
AT MANY SITES AFTER 06Z.
MVFR/IFR CONDITIONS MAY FORM SOUTH OF KWWR-KOUN AFTER 06Z. DID NOT
MENTION THINKING THESE LOWER CONDITIONS WILL NOT FORM IN THESE
LOCATIONS BEFORE 12Z WEDNESDAY.
MBS
&&
.PREV DISCUSSION... /ISSUED 358 AM CDT TUE APR 21 2015/
DISCUSSION...
THE FORECAST CHALLENGE OF THE DAY IS SEVERE WEATHER POTENTIAL
THROUGH FRIDAY.
THIS MORNING...ISOLATED TO SCATTERED SHOWERS FROM WEAK MID LEVEL
MOISTURE CONVERGENCE/ISENTROPIC LIFT WILL CONTINUE MAINLY ACROSS
SOUTHERN OKLAHOMA. CANNOT RULE OUT A RUMBLE OF THUNDER...BUT NO
SEVERE WEATHER WILL OCCUR. ANY RAINFALL WILL BE LIGHT AND UNDER
0.10 INCH.
THIS AFTERNOON...SKIES WILL CLEAR AND ALLOW FOR GOOD DAYTIME
HEATING. THINK CAPPING WILL BE TOO STRONG FOR STORM
DEVELOPMENT...EXCEPT PERHAPS NEAR A WEAK SURFACE BOUNDARY OVER
SOUTHERN KANSAS ACCORDING TO THE LATEST HRRR RUN. KEPT 20 PERCENT
CHANCE FOR STORMS NEAR THE KANSAS AND OKLAHOMA STATE LINE EAST OF
ALVA AFTER 4 PM. IF THESE STORMS FORM...THEY COULD BE SEVERE WITH
SOME LARGE HAIL UP TO GOLF BALLS AND DAMAGING WINDS UP TO 60 MPH
AS STRONG 0-6 KM SHEAR AND MUCAPE AROUND 1000 J/KG SUPPORT SOME
SEVERE POTENTIAL.
TONIGHT...WILL MONITOR FOR ADDITIONAL STORM FORMATION...MAINLY
AFTER MIDNIGHT ACROSS WESTERN OKLAHOMA ON THE NOSE OF THE LOW
LEVEL JET. LATEST MODELS HAVE BEEN TRENDING SLOWER WITH STORM
DEVELOPMENT. WITH INCREASING ELEVATED INSTABILITY AND STRONG 0-6
KM SHEAR...STORMS WILL BEGIN WITH LARGE HAIL UP TO GOLF BALLS AS
THE MAIN HAZARD...BUT MAY TRANSITION TO SOME WIND AND HAIL AS
STORMS MAY FORM INTO A CLUSTER OR LINE THEN MOVE EAST OR SOUTHEAST
TOWARDS DAYBREAK...MAINLY AFFECTING WESTERN OKLAHOMA. A FEW
ADDITIONAL SEVERE STORMS MAY BE NEAR A DEVELOPING COLD FRONT IN
NORTHERN OKLAHOMA. WIDESPREAD SEVERE SEEMS UNLIKELY TONIGHT.
WEDNESDAY...AN ACTIVE DAY OF SEVERE WEATHER MAY OCCUR...
ESPECIALLY ACROSS THE SOUTHERN HALF OF OKLAHOMA AND NORTH TEXAS. A
COMPLEX OF STORMS MAY OCCUR DURING THE MORNING HOURS AND MOVE EAST
OR SOUTHEAST BRINGING SOME WIND AND HAIL REPORTS AS WELL AS
LOCALLY HEAVY RAINFALL. REDEVELOPMENT MAY OCCUR DURING THE
AFTERNOON AND EVENING NEAR THE OUTFLOW BOUNDARY WHICH MAY BE NEAR
THE RED RIVER. THERE IS SOME POTENTIAL FOR SIGNFICANT SEVERE
INCLUDING GIANT HAIL GREATER THAN GOLF BALLS...DAMAGING WINDS OVER
70 MPH...AND PERHAPS TORNADOES IF LOW LEVEL SHEAR IS STRONG
ENOUGH...BUT CONFIDENCE OF THIS OCCURRING REMAINS LOW AS NOT SURE
HOW THE CONVECTION DURING THE MORNING AFFECTS THE ENVIRONMENT
DURING THE AFTERNOON AND EVENING HOURS. IT APPEARS NORTHERN
OKLAHOMA MAY NOT RECEIVE MANY STORMS OR SEVERE WEATHER WHERE THE
AIR WILL BE COOLER AND MORE STABLE.
WEDNESDAY NIGHT INTO THURSDAY...A FEW SEVERE STORMS MAY LINGER
OVER FAR SOUTHERN OKLAHOMA AND NORTH TEXAS WITH LARGE HAIL...
DAMAGING WINDS...AND HEAVY RAINFALL. HOWEVER...MOST STORMS MAY BE
SOUTH OF THE RED RIVER...LEAVING BEHIND COOL AND STABLE CONDITIONS
ACROSS OKLAHOMA. CONFIDENCE OF SEVERE STORMS DURING THIS TIME
FRAME REMAINS LOW AS NOT SURE HOW WEDNESDAY/S CONVECTION CHANGES
THE AIRMASS ACROSS THE REGION. WENT BELOW MODEL GUIDANCE
TEMPERATURES.
FRIDAY...ANOTHER ROUND OF SEVERE THUNDERSTORMS...POSSIBLY WITH
SIGNIFICANT SEVERE...MAY RETURN TO THE AREA. VERY STRONG
SHEAR/WINDS WOULD SUPPORT FAST MOVING SUPERCELLS. HOWEVER...
MOISTURE AND INSTABILITY REMAIN QUESTIONABLE...ESPECIALLY AS
CONVECTION OVER TEXAS MAY LIMIT THE NORTHWARD PROGRESS OF RICHEST
MOISTURE AND HIGHEST INSTABILITY. REGARDLESS...WILL CLOSELY
MONITOR. ELEVATED TO CRITICAL FIRE WEATHER CONDITIONS ALONG WITH
WINDY AND HOT WEATHER MAY FORM BEHIND A DRYLINE.
SATURDAY THROUGH MONDAY...A QUIETER WEATHER PATTERN IS FORECAST
WITH NEAR AVERAGE TEMPERATURES.
MBS
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 77 54 69 54 / 20 20 50 40
HOBART OK 77 54 73 54 / 10 40 70 40
WICHITA FALLS TX 78 57 76 57 / 10 20 40 40
GAGE OK 79 49 66 46 / 10 40 40 30
PONCA CITY OK 78 49 64 47 / 20 30 30 30
DURANT OK 76 57 75 60 / 30 10 60 40
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
25/17/17
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
652 AM CDT TUE APR 21 2015
.AVIATION...
/12Z TAFS/
CLEAR SKIES ARE IN PLACE AS UPPER LEVEL MOISTURE PUSHES TO THE
EAST AND LIGHT WINDS FROM THE NORTHWEST AND NORTHEAST DOMINATE AT
THE SURFACE. HOWEVER...THIS CONDITION IS FORECAST TO QUICKLY
CHANGE THIS MORNING AS SOUTHERLY WINDS RETURN. MVFR CONDITIONS ARE
EXPECTED ACROSS KSAT AND KSSF AROUND 14Z TO 16Z AS A POCKET OF LOW
CLOUDS FORM ACROSS THE SAN ANTONIO METRO AREA. CLOUDS WILL
INCREASE THROUGHOUT THE DAY AS GULF MOISTURE PUSHES NORTHWARD FOR
THE RETURN OF MVFR CONDITIONS ACROSS AREA SITES THIS EVENING. AREA
SOUNDINGS AND MOS GUIDANCE ARE SUGGESTING CIGS TO LOWER TO
IFR/LIFR OVERNIGHT AS SATURATED AIR DOMINATES THE AREA. WINDS WILL
BE FROM THE SOUTHEAST FOR THE MOST PARTS WITH SPEEDS OF 10 KNOTS
AND GUSTING UP TO 21 KNOTS ACROSS KDRT THIS AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 442 AM CDT TUE APR 21 2015/
SHORT TERM (TODAY THROUGH WEDNESDAY)...
A WEAK UPPER LEVEL DISTURBANCE MOVED OVER THE AREA OVERNIGHT AND
CLEARING SKIES ARE LEFT IN ITS WAKE. THE CLEARING SHOULD BE
TEMPORARY AS A MOIST LAYER AT 850 HPA SHOULD SATURATE IN MANY
AREAS. THE CLOUDS WILL PROBABLY BE SCT VARIABLE TO BKN SINCE THE
MOISTURE LAYER APPEARS THIN. THUS WILL GO WITH SLIGHTLY ABOVE
BLENDED GUIDANCE HIGHS TODAY. RAP SOUNDINGS SUGGEST A BREAKABLE
CAP SHOULD THERE BE ENOUGH MOISTURE SO WILL CONTINUE WITH ISOLATED
POPS. AN UPPER LOW CURRENTLY OVER SOUTHERN CA WILL CONTINUE TO
CARVE DEEPER OVER THE BAJA PENINSULA THROUGH WEDNESDAY. DEEPENING
MOISTURE WILL LEAD TO INCREASED RAIN CHANCES AND A FEW STRONG
STORMS AND POSSIBLE SUPERCELLS AS NOTED IN THE SPC DAY 2 OUTLOOK.
LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)...
A FAIRLY LIGHT LOW LEVEL FLOW WEDNESDAY NIGHT INTO THURSDAY MEANS
THAT THERE COULD BE SOME REMNANT OUTFLOW BOUNDARIES LEFT FROM
WEDNESDAY STORMS TO BRING ADDITIONAL STORM FOCUS FOR THURSDAY AS
THE UPPER LOW BEGINS TO LIFT INTO THE SOUTHERN ROCKIES. HIGHEST
POPS OF THE WEEK ARE THUS SAVED FOR THURSDAY NIGHT INTO FRIDAY.
THE EJECTION OF THE LOW INTO A SHALLOW TROUGH LEAVES SOME COVERAGE
UNCERTAINTIES THIS FAR SOUTH...SO DO NOT WANT TO OVER-ADVERTISE
THE SEVERE THREAT BEYOND A NOD IN THE HWO. POPS SHOULD LOWER
SATURDAY INTO SUNDAY AS FLAT RIDGING ALOFT RETURNS. MOISTURE IS
SUFFICIENT FOR STORMS...BUT EXPECT A STRONGER CAPPING INVERSION.
ANOTHER LOW LATITUDE UPPER DISTURBANCE IS FORECAST BY THE GFS TO
BRING RAIN AND STORMS BY MIDWEEK...BUT WILL KEEP WITH THE MORE
CONSERVATIVE ECMWF UNTIL THE PATTERN DIFFERENCES BETWEEN MODELS
DECREASE. TEMPERATURES THROUGH THE PERIOD SHOULD CONTINUE TO BE
SEASONAL. A WEAK FRONT EXPECTED SATURDAY WILL PROBABLY ADD TO
DAYTIME TEMPERATURES THROUGH REDUCED CLOUDINESS.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 80 66 82 69 86 / 20 10 30 30 20
AUSTIN BERGSTROM INTL AIRPORT 79 66 81 68 85 / 20 10 30 30 20
NEW BRAUNFELS MUNI AIRPORT 79 66 82 69 87 / 20 20 30 30 20
BURNET MUNI AIRPORT 77 66 81 68 85 / 20 20 30 30 20
DEL RIO INTL AIRPORT 81 67 86 70 88 / 20 20 20 10 20
GEORGETOWN MUNI AIRPORT 79 67 82 68 86 / 20 10 30 30 20
HONDO MUNI AIRPORT 82 67 82 69 87 / 20 20 30 20 20
SAN MARCOS MUNI AIRPORT 78 66 81 68 85 / 20 20 30 30 20
LA GRANGE - FAYETTE REGIONAL 79 66 82 70 85 / 20 10 30 30 20
SAN ANTONIO INTL AIRPORT 80 68 82 71 86 / 20 20 30 20 20
STINSON MUNI AIRPORT 81 68 82 71 87 / 20 20 30 20 20
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...17
SYNOPTIC/GRIDS...18
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
138 PM PDT TUE APR 21 2015
.SYNOPSIS...
A COUPLE UPPER LEVEL DISTURBANCES MOVING THROUGH THE REGION TODAY
THROUGH THURSDAY...IN ADDITION TO AN UNSTABLE ATMOSPHERE...WILL
RESULT IN THE CHANCES FOR SHOWERS AND THUNDERSTORMS...MAINLY DURING
THE AFTERNOON AND EARLY EVENING HOURS EACH DAY OVER THE MOUNTAIN AND
DESERT AREAS. BEST CHANCES AND MOST WIDESPREAD SHOWER ACTIVITY
EXPECTED ON THURSDAY...WHEN SCATTERED SHOWERS AND POSSIBLE
THUNDERSTORMS MAY OCCUR OVER THE COAST AND VALLEY AREAS AS WELL. A
THIRD DISTURBANCE MOVING THROUGH ON FRIDAY COULD BRING SOME LIGHT
SHOWERS MAINLY TO AREAS OVER AND WEST OF THE MOUNTAINS. NIGHT AND
MORNING STRATUS WILL PERSIST OVER THE COAST...VALLEY AND COASTAL
SLOPE AREAS...WITH ONLY PARTIAL CLEARING AT BEST DURING THE DAY-TIME
HOURS. DAY-TIME HIGH TEMPERATURES WILL FALL TO SEVERAL DEGREES BELOW
NORMAL. ONSHORE FLOW WILL RESULT IN CONTINUED GUSTY WEST WINDS IN
THE MOUNTAINS AND DESERTS. INCREASING HIGH PRESSURE ALOFT SATURDAY
THROUGH MONDAY WILL BRING WARMING...DRYING CONDITIONS...AND A
SHALLOW MARINE LAYER.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA
INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN
SAN BERNARDINO COUNTIES...
VISIBLE SATELLITE INDICATES THAT MARINE LAYER STRATUS HAS NOT
CLEARED OUT OF MOST COAST/VALLEY/COASTAL SLOPE AREAS THIS AFTERNOON.
12Z MIRAMAR SOUNDING SHOWS A MARINE LAYER INVERSION AT 4000 FEET.
VISIBLE SATELLITE ALSO SHOWS SOME TOWERING CUMULUS/CUMULONIMBUS
OVER THE RIVERSIDE AND SAN BERNARDINO COUNTY MOUNTAINS...AND THE
HIGH DESERTS...WITH RADAR SHOWING SOME LIGHT SHOWERS IN THESE AREAS.
RADAR WAS A LITTLE MORE ACTIVE IN THE LATE MORNING HOURS...WITH
NUMEROUS LIGHTNING STRIKES OVER THE BIG BEAR LAKE AREA...AND SOME
OVER THE RIVERSIDE MOUNTAINS AND COACHELLA VALLEY. THERE WAS ALSO A
REPORT OF PEA SIZE HAIL IN BIG BEAR. THE SHOWERS AND THUNDERSTORMS
WERE THE RESULT OF A VORTICITY MAX MOVING UP FROM THE SOUTH AROUND
THE UPPER LOW CIRCULATION. HOWEVER...BARELY ANY MEASURABLE RAIN WAS
REPORTED FROM THESE SHOWERS AND THUNDERSTORMS...WITH ONLY SOME 0.01
TO 0.02 INCH REPORTS.
ACCORDING TO THE NAM12...THERE IS A SLIGHT INFLUX OF MID-LEVEL
MOISTURE THAT OCCURS THIS AFTERNOON OVER WESTERN RIVERSIDE AND
SOUTHWEST SAN BERNARDINO COUNTIES...WITH SURFACE BASED CAPE
INCREASING TO 400-600 J/KG...LIFTED INDEX OF -2 TO -5 DEG C...MOVING
THROUGH THESE AREAS AS THE UPPER LOW SITS OVER EXTREME SOUTHWEST
CALIFORNIA. SURFACE HEATING MAY BE LIMITED OVER THE HIGH DESERTS AND
SAN BERNARDINO MOUNTAINS DUE TO THE CLOUDY CONDITIONS IN THAT AREA
AT THE MOMENT. THUS...THE RIVERSIDE AND SAN DIEGO COUNTY MOUNTAINS
AND DESERTS MAY BE MORE FAVORED FOR AFTERNOON AND EVENING SHOWERS
AND THUNDERSTORMS...AND THE 19Z HRRR DEPICTS THIS WELL. CHANCES FOR
SHOWERS DIMINISH OVERNIGHT AS INSTABILITY FROM DAY-TIME SURFACE
HEATING SHUTS OFF.
FOR WEDNESDAY...ANOTHER...DEEPER TROUGH DEVELOPS OVER THE
REGION...WITH SOME ADDITIONAL MID-LEVEL MOISTURE ADVECTION UNDER
SOUTHWEST FLOW. DYNAMICS LOOK WEAKER...WITH NOT A LOT OF PVA...
UPPER LEVEL DIVERGENCE OR LOW LEVEL CONVERGENCE OF WINDS INDICATED.
INSTABILITY ALSO APPEARS TO BE A LITTLE LESS...WITH SURFACE BASED
CAPE OF 100-500 J/KG AND LIFTED INDEX OF -1 TO -3 DEG C.
HOWEVER...WITH THE DAY-TIME HEATING...SOME SHOWERS AND THUNDERSTORMS
COULD DEVELOP OVER THE MOUNTAINS AND PORTIONS OF THE DESERTS DURING
THE AFTERNOON AND EARLY EVENING HOURS. THE HI-RES MODELS DO SHOW
MOUNTAIN AND HIGH DESERT CONVECTION BEING GENERATED GENERALLY IN THE
SAME LOCATIONS AS TODAY...AND THE WEDNESDAY POPS REFLECT THAT.
ON THURSDAY...THE TROUGH AXIS MOVES INLAND...BRINGING DEEPER
MOISTURE THAN TUESDAY/WEDNESDAY...SLIGHTLY COLDER AIR ALOFT...AND A
CONTINUED UNSTABLE ATMOSPHERE. DYNAMICS APPEAR TO BE STRONGER AS
WELL...WITH BETTER PVA AND UPPER LEVEL DIVERGENCE INDICATED. HIGH-
RES MODELS...PARTICULARLY THE CANSAC-WRF AND LOCAL WRF...SHOW THE
MOST WIDESPREAD SHOWERS AND THUNDERSTORMS OCCURRING ON THIS DAY AS
OPPOSED TO TUESDAY/WEDNESDAY. AS THE TROUGH MOVES INLAND...THE LOW-
LEVEL MOIST LAYER LOOKS TO DEEPEN TO NEAR 7000-10000
FEET...WHICH...IN ADDITION TO THE DYNAMICS...COULD PRODUCE SCATTERED
SHOWERS AND POSSIBLE THUNDERSTORMS OVER THE COAST AND VALLEY AREAS.
FOR TODAY THROUGH THURSDAY...SNOW LEVELS LOOK TO BE AROUND 7000-8000
FEET...WITH A COUPLE INCHES OF SNOW POSSIBLE ABOVE THAT ELEVATION.
OVERALL RAINFALL AMOUNTS WILL BE LIGHT...EXCEPT UNDERNEATH ANY HEAVY
SHOWERS OR THUNDERSTORMS. SINCE WINDS ALOFT WILL GENERALLY BE
WEAK...THE SHOWERS AND THUNDERSTORMS WILL LIKELY BE SLOW
MOVING...AND SOME LOCALIZED MINOR FLOODING COULD OCCUR. AS FAR AS
THE MARINE LAYER GOES...STRATUS WILL CONTINUE TO BE VERY DEEP...WITH
NIGHT AND MORNING STRATUS MOVING DEEP INTO THE VALLEYS AND THE
COASTAL SLOPES...AND ONLY PARTIAL CLEARING AT BEST DURING THE DAYS.
ONSHORE FLOW AT THE SURFACE WILL RESULT IN GUSTY WEST WINDS IN THE
MOUNTAINS AND DESERTS EACH DAY...STRONGEST ON THURSDAY WITH LOCAL
GUSTS TO 55 MPH POSSIBLE THAT DAY. FINALLY...DAY-TIME HIGH
TEMPERATURES WILL FALL TO 5-10 DEGREES BELOW NORMAL...AND LOCALLY 15
DEGREES BELOW NORMAL.
THE TROUGH MOVES OFF TO THE EAST LATE THURSDAY NIGHT...WITH
DIMINISHING SHOWER CHANCES GOING INTO FRIDAY MORNING. HOWEVER...SOME
SHOWERS MAY CONTINUE TO OCCUR DURING THE DAY FRIDAY AS A NEW SHORT-
WAVE TROUGH MOVES THROUGH. THESE SHOWERS ARE MOST LIKELY TO DEVELOP
WITHIN THE LOW-LEVEL MOIST LAYER OVER AND WEST OF THE MOUNTAINS. A
LACK OF INSTABILITY WILL LIKELY NOT RESULT IN THUNDERSTORMS ON THIS
DAY. ANY PRECIP AMOUNTS WILL BE FAIRLY LIGHT.
SATURDAY INTO NEXT MONDAY...HIGH PRESSURE WILL GRADUALLY DEVELOP
OVER THE REGION...RESULTING IN WARMER...DRIER WEATHER. ONSHORE FLOW
WILL CONTINUE FOR THE MOST PART...WITH A SHALLOW MARINE LAYER. DAY-
TIME HIGHS LIKELY TO REACH ABOVE NORMAL BY MONDAY.
&&
.AVIATION...
212000Z...COAST/VALLEYS...SCT/BKN LOW CLOUDS...WITH BASES 4000-5000
FEET MSL AND TOPS TO 6000 FEET MSL...WILL CONTINUE THROUGHOUT THE
DAY AND LOCALLY OBSCURE HIGHER TERRAIN AT TIMES. STRATUS WILL
QUICKLY BECOME OVC THIS EVENING FROM THE COAST TO THE COASTAL
MOUNTAIN SLOPES...WITH BASES FROM 3000-4000 FT MSL AND TOPS NEAR
5000 FT MSL. LOW CLOUDS WEDNESDAY WILL SLOWLY BECOME SCT THROUGH
WEDNESDAY AFTN.
MTNS AND DESERTS...CLOUDS OVER MOUNTAIN CRESTS AND HIGH DESERTS
THROUGH THIS EVENING. -SHRA/-TSRA CURRENTLY OVER THE HIGH
DESERTS...WITH DEVELOPMENT POSSIBLE OVER THE MOUNTAIN CRESTS THROUGH
THIS AFTERNOON. STORM BASES ARE NEAR 10 KFT WITH TOPS TO 25 KFT
...AND WILL BE CAPABLE OF PRODUCING GUSTY SFC WINDS AND SMALL HAIL.
SHOWERS WILL END BY 02Z...WITH RESIDUAL HIGHER DEBRIS CLOUDS
OVERNIGHT. ISOLATED AREAS OF BREEZY WEST WINDS THROUGH MTN
PASSES...WITH GUSTS TO 40 KT...WILL BE POSSIBLE TONIGHT.
&&
.MARINE...
130 PM...NO HAZARDOUS MARINE WEATHER IS FORECAST THROUGH SATURDAY.
&&
.SKYWARN...
SKYWARN ACTIVATION IS NOT ANTICIPATED TODAY. HOWEVER WEATHER
SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.
&&
$$
PUBLIC...HARRISON
AVIATION/MARINE...JJT
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1230 PM CDT TUE APR 21 2015
.UPDATE...
ISSUED AT 1012 AM CDT TUE APR 21 2015
MAIN FORECAST CONCERN WILL BE WITH THE WINDS TODAY. ALREADY
STARTING TO SEE WIND GUSTS TO AROUND 30 MPH ACROSS THE NORTHERN
CWA. LATEST HRRR AND RAP DATA SUGGESTING A PERIOD OF 40-45 KNOTS
FOR A FEW HOURS EARLY THIS AFTERNOON ACROSS MAINLY AREAS ALONG AND
NORTH OF I-74...ALTHOUGH THEY ARE ALSO NOW SUGGESTING THIS AS FAR
SOUTH AS THE I-70 CORRIDOR. HAVE NOT GONE THAT HIGH SO FAR SOUTH
AS CLOUDS THERE WILL BE ON THE INCREASE AND PREVENT FULL MIXING...
BUT RAISED THE WIND GUSTS A TAD OVER THE NORTH AS MOSTLY SUNNY
CONDITIONS CONTINUE INTO AT LEAST MID AFTERNOON.
&&
.SHORT TERM...(TODAY)
ISSUED AT 323 AM CDT TUE APR 21 2015
WINDY CONDITIONS WILL ONCE AGAIN DEVELOP ACROSS CENTRAL ILLINOIS
TODAY, THANKS TO A TIGHTENING PRESSURE GRADIENT AND DEEP-LAYER
MIXING. THE STRONGEST WINDS WILL BE FOCUSED ALONG/NORTH OF THE I-74
CORRIDOR, WHERE FORECAST SOUNDINGS SUGGEST SUSTAINED WINDS OF AROUND
30MPH WITH GUSTS UP TO 40MPH AT TIMES. WILL THEREFORE ISSUE A
WIND ADVISORY FOR THIS AREA FROM 11AM TO 7PM. FURTHER SOUTH
ACROSS THE REMAINDER OF THE KILX CWA, WINDS WILL REMAIN BELOW
ADVISORY CRITERIA, MAINLY IN THE 25 TO 30MPH RANGE. SKIES WILL
BE MOSTLY SUNNY THROUGH MUCH OF THE DAY, WITH AN INCREASE IN
CLOUDS NOTED ACROSS THE FAR SOUTH DURING THE AFTERNOON AS A
MID-LEVEL SHORT-WAVE APPROACHES FROM THE WEST. ALL MODELS ARE
DEVELOPING SCATTERED SHOWERS/THUNDER IN ADVANCE OF THIS WAVE, BUT
PRIMARILY KEEP THE ACTIVITY JUST SOUTH OF THE CWA. HIGHER-RES
MODELS SUCH AS THE HRRR ARE SLIGHTLY FURTHER NORTH, SO HAVE OPTED
TO INCLUDE SLIGHT CHANCE POPS FOR SHOWERS SOUTH OF I-70 THIS
AFTERNOON. THANKS TO INCREASED SUNSHINE, HIGH TEMPERATURES WILL
BE A FEW DEGREES WARMER THAN YESTERDAY, WITH READINGS CLIMBING
INTO THE LOWER TO MIDDLE 60S.
.LONG TERM...(TONIGHT THROUGH MONDAY)
ISSUED AT 323 AM CDT TUE APR 21 2015
MAIN CHALLENGES IN THE EXTENDED CONTINUE TO BE FROST POTENTIAL
WEDNESDAY/THURSDAY NIGHTS, AS WELL AS, TIMING OF NEXT PRECIP EVENT
BY THE END OF THE WEEK.
DEEP UPPER LOW CURRENTLY CENTERED OVER THE WESTERN GREAT LAKES WILL
BE THE DOMINANT WEATHER FEATURE ACROSS THE MIDWEST FOR THE NEXT FEW
DAYS, RESULTING IN COOL CONDITIONS THROUGH FRIDAY. AS A PIECE OF
ENERGY ROTATES AROUND THE LOW, A WEAK COLD FRONT WILL DROP THROUGH
ILLINOIS TONIGHT. FORECAST SOUNDINGS ARE INITIALLY QUITE DRY:
HOWEVER, THE LATEST MODELS SHOW QUITE A BIT MORE TOP-DOWN MOISTENING
THAN IN PREVIOUS RUNS. AS A RESULT, THINK SCATTERED LIGHT SHOWERS
WILL ACCOMPANY THE FRONT TONIGHT, WITH PERHAPS A FEW SHOWERS
LINGERING INTO WEDNESDAY MORNING ACROSS THE FAR SE. ONCE THE
FRONT EXITS, CANADIAN HIGH PRESSURE WILL BUILD INTO THE REGION FOR
THE MIDDLE AND END OF THE WEEK. THE RIDGE AXIS IS PROGGED TO BE
JUST WEST OF THE MISSISSIPPI RIVER BY 12Z THURSDAY, SO AM
EXPECTING WINDS TO DIMINISH CONSIDERABLY AS THE PRESSURE GRADIENT
WEAKENS. WITH CLEAR SKIES AND LIGHT WINDS, OVERNIGHT LOWS WILL
DIP INTO THE LOWER TO MIDDLE 30S, LEADING TO FROST DEVELOPMENT
ACROSS MUCH OF THE AREA. IF SKIES REMAIN CLEAR, ANOTHER
POTENTIALLY FROSTY NIGHT WILL OCCUR THURSDAY NIGHT AS WELL.
FURTHER OUT, MODELS ARE HAVING CONSIDERABLE DIFFICULTY PINNING DOWN
THE END OF THE WEEK SYSTEM. SOLUTIONS HAVE BEEN FLIP-FLOPPING FROM
RUN TO RUN, SO OVERALL FORECAST CONFIDENCE BEYOND THURSDAY REMAINS
LOWS. THE 00Z APR 21 GFS HAS MADE A MAJOR SHIFT BACK TO A SOLUTION
IT FEATURED A COUPLE OF DAYS AGO. MEANWHILE, BOTH THE ECMWF AND GEM
SEEM TO BE HEADING IN THE OPPOSITE DIRECTION. GIVEN SO MUCH MODEL
INCONSISTENCY, PREFER TO MAKE VERY FEW CHANGES TO THE EXTENDED.
WITH CANADIAN HIGH PRESSURE INITIALLY IN PLACE ACROSS THE MIDWEST ON
WEDNESDAY/THURSDAY, STILL THINK A SLOWER ARRIVAL OF THE NEXT STORM
SYSTEM MAKES SENSE. AS A RESULT, HAVE KEPT FRIDAY DRY DESPITE WHAT
THE ECMWF AND GEM ARE ADVERTISING. HAVE INTRODUCED POPS FRIDAY
NIGHT INTO SATURDAY AS A SYSTEM OVER THE DESERT SOUTHWEST GETS
KICKED EASTWARD. STILL QUITE A BIT OF UNCERTAINTY CONCERNING HOW
FAR NORTH PRECIP WILL SPREAD, BUT HAVE STUCK WITH PREVIOUS THINKING
OF KEEPING HIGHEST POPS FOCUSED ACROSS THE SOUTHERN HALF OF THE CWA.
THIS IS IN GOOD AGREEMENT WITH THE LATEST GFS, BUT NOT THE ECMWF/GEM
WHICH BOTH FOCUS PRECIP MUCH FURTHER NORTH. ONCE THE SYSTEM EXITS,
A RETURN TO DRY WEATHER IS ANTICIPATED FOR SUNDAY BEFORE ANOTHER
FAST-MOVING NORTHERN-STREAM WAVE POTENTIALLY BRINGS A FEW SHOWERS
BACK INTO THE PICTURE BY MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1230 PM CDT TUE APR 21 2015
STRONG WINDS GUSTING TO THE SURFACE NOW...WITH SOME GUSTS NEAR 35
KNOTS AT MIDDAY AROUND KPIA. STRONGEST WINDS EXPECTED IN THE
KPIA-KCMI CORRIDOR THROUGH AFTERNOON WITH SEVERAL GUSTS 30-40
KNOTS...WITH GUSTS STARTING TO TAIL OFF TOWARD 00Z. HAVE SEEN SOME
INCREASE IN DIURNAL CLOUDS AROUND 6000 FEET...AND VFR CONDITIONS
EXPECTED TO PREVAIL...ALTHOUGH CEILINGS WILL THICKEN UP AFTER
SUNSET. AREA OF RAIN SHOWERS WITH A FRONT WILL MOVE THROUGH
CENTRAL ILLINOIS MID TO LATE EVENING...BUT A FAIR AMOUNT OF DRY
AIR IS NOTED BELOW 4000 FEET ON FORECAST SOUNDINGS...SO WILL
CONTINUE MENTION WITH VCSH FOR NOW. HOWEVER...CEILINGS SHOULD
DROP CLOSER TO AROUND 3500-4000 FEET FOR SEVERAL HOURS...BEFORE
RISING OVERNIGHT BEHIND THE FRONT. SOME GUSTY NORTHWEST WINDS
EXPECTED AGAIN LATE WEDNESDAY MORNING...ALTHOUGH THESE SHOULD BE
ABOUT 20 KNOTS OR LESS.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR ILZ027>031-037-038-
043>046.
&&
$$
UPDATE...GEELHART
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...GEELHART
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
113 PM EDT TUE APR 21 2015
.SYNOPSIS...
ISSUED AT 107 PM EDT TUE APR 21 2015
STRONG WESTERLY WINDS WILL PERSIST THROUGH THE AFTERNOON WITH GUSTS
AS HIGH AS 45 MPH. THERE IS ALSO A SLIGHT CHANCE FOR A FEW
AFTERNOON RAIN SHOWERS...MAINLY ALONG AND NORTH OF THE TOLL ROAD.
HIGHS TODAY WILL BE IN THE MID 50S WITH LOWS TONIGHT IN THE MID
30S. COOL AND DRY CONDITIONS WILL THEN CONTINUE THROUGH THE REST
OF THIS WEEK.
&&
.UPDATE...
ISSUED AT 107 PM EDT TUE APR 21 2015
WIND ADVISORY GENERALLY ON TRACK WITH SEVERAL LOCATIONS SEEING
EITHER SUSTAINED AND/OR GUSTS NEAR OR JUST ABOVE CRITERIA. FEW
POCKETS UPSTREAM OF WIND GUSTS OVER 50 MPH WHICH MAY STILL MOVE IN
MID TO LATE AFTERNOON AS A COLD FRONT SWEEPS THROUGH AND AIDS
MIXING EVEN MORE. SCATTERED SHOWERS RAPIDLY DEVELOPED ACROSS FAR
NE INDIANA INTO NW OHIO BUT ARE DEPARTING JUST AS FAST. ADDITIONAL
SHOWERS ARE POSSIBLE ACROSS THE NE HALF OR SO OF THE AREA WITH A
NUDGE SOUTHWARD IN POPS WARRANTED IN UPDATE. THE STRONGEST SHOWERS
COULD PRODUCE SMALL HAIL AND LOCALLY INCREASE WIND SPEEDS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 356 AM EDT TUE APR 21 2015
STRONG WINDS WILL BE THE FORECAST MESSAGE OF THE DAY. STILL A
DECENT HEIGHT/PRESSURE GRADIENT IN PLACE BETWEEN LARGELY
BAROTROPIC LOW PRESSURE NEAR JAMES BAY AND ANTICYCLONE ACROSS THE
GULF COAST. HOWEVER...THE REAL KEY FACTOR FOR GUSTY WINDS WILL BE
VERY DEEP BOUNDARY LAYER MIXING. COMBINATION OF DRY AIR ADVECTION
NEAR THE SURFACE...STRONG LATE APRIL SUN...AND VERY COLD
CONDITIONS ALOFT WILL SET THE STAGE FOR MIXING HEIGHTS TO CLIMB TO
AT LEAST 6 KFT WITH SOME MODELS (GFS AND RAP) SUGGESTING BOUNDARY
LAYER DEPTHS WILL APPROACH 9 KFT. WIND SPEEDS AT THOSE LEVELS WILL
BE IN THE 40-50 KT RANGE. NO DOUBT IT WILL BE WINDY BUT THE
QUESTION IS WILL IT REACH ADVISORY CRITERIA (39KTS/45MPH). LACK OF
GOOD ISENTROPIC DESCENT TO FORCE DOWN HIGHER MOMENTUM AIR IS
CONCERNING...AS IS LACK OF ISALLOBARIC COMPONENT. ALWAYS SOME
QUESTION AS TO HOW EFFICIENT TURBULENT MIXING ALONE WILL BE IN
PRODUCING HIGHER GUSTS AT THE SURFACE....ESPECIALLY WHEN MIXING
OVER SUCH A DEEP LAYER...AND NAM (AS WELL AS SOME OTHER HI-RES
MODEL) SOUNDINGS ARE NOT QUITE AS BULLISH. THAT BEING SAID...MOST
MODELS SHOW WIND SPEEDS AROUND 40 KTS AT THE TOP OF THE BOUNDARY
LAYER AND SEVERAL INDICATE MIXING INTO SOME 50 KT WINDS. GIVEN
THIS AND POTENTIAL FOR CONVECTIVE SHOWERS TO ENHANCE DOWNWARD
MOMENTUM TRANSFER (SEE NEXT PARAGRAPH)...FEEL IT IS PRUDENT TO GO
AHEAD AND PULL THE TRIGGER ON A WIND ADVISORY. EVEN IF MORE
IMPRESSIVE GFS AND RAP FORECAST SOUNDINGS/WIND FIELDS DONT
VERIFY...WILL STILL BE CLOSE TO ADVISORY CRITERIA.
500MB TEMPS BELOW -30C WILL SUPPORT A VERY DEEP LAYER OF STEEP LAPSE
RATES DURING THE DAY TODAY. DEGREE OF MOISTURE AVAILABLE IS VERY
MUCH IN QUESTION AND REMAINS A SIGNIFICANT LIMITING FACTOR FOR
PRECIP DEVELOPMENT BUT SHREDS OF VORTICITY ROTATING AROUND LARGE
CLOSED LOW COULD PROVIDE JUST ENOUGH MIDLEVEL CONVERGENCE/SATURATION
TO WARRANT A FEW ISOLATED SPRINKLES/SHOWERS...MAINLY IN OUR NORTHERN
COUNTIES. INHERITED FORECAST OF LOW CHANCE POPS ACROSS THE NORTH
SEEMS REASONABLE. IF ANY SHOWERS DO MANAGE TO DEVELOP...STRONG
NEGATIVE BUOYANCY DUE TO EVAPORATIONAL COOLING WITH "INVERTED V"
SOUNDING COULD HELP MIX DOWN SOME HIGHER GUSTS. COULD ALSO BE SOME
SMALL HAIL GIVEN COLD/DRY AIRMASS BUT VERY MARGINAL CAPE VALUES
SUGGEST ANY SUBSTANTIVE UPDRAFTS WILL BE FEW AND FAR BETWEEN.
SLIGHT CHANCE FOR SOME PRECIP LATE TONIGHT AS A MORE POTENT
SHORTWAVE SWINGS THROUGH THE AREA. MOST MODELS KEEP LOW LEVEL FGEN
RESPONSE JUST TO OUR SOUTH THOUGH AND WILL HOLD WITH A LOW CHANCE
POP. DESPITE VERY COLD AIR ALOFT...TEMPS SHOULD RECOVER INTO THE MID
50S TODAY GIVEN DEEP MIXING. LOWS TONIGHT SHOULD GENERALLY HOLD IN
THE MID 30S WITH STEADY WEST WINDS AND AT LEAST SOME CLOUDS KEEPING
THE THREAT OF FROST LOW.
&&
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 356 AM EDT TUE APR 21 2015
NEG HGT ANOMALIES WILL PERSIST OVR SE CANADA THIS PD IN ASSOCN/W SLW
EWD MEANDER OF DEEP CUTOFF FM THE LAKES THROUGH SE CANADA. THIS
YIELDS A CONTN OF NW FLW ALOFT ACRS THE LAKES/OH VALLEY ALG W/MUCH
BLO NORMAL TEMPS AND DRY WX THIS PD.
HWVR POTENTIAL PITFALL EXISTS IN FRI NIGHT-SAT TIME FRAME W/BOTH
HANDLING/PLACEMENT OF NWWD ORIENTED MID LVL TROUGH AXIS EXTENDING
BACK INTO THE NRN PLAINS AND NEWD EJECTION OF SRN STREAM SW LOCATED
OFF THE SRN CA COAST THIS MORNING. EC ELUCIDATED THIS POSSIBILITY
FIRST LAST NIGHT AND NOW HAS GROWING SPRT FM GEM. THUS FELT IT
PRUDENT TO PLACE SOME CONFIDENCE IN ALLBLEND GUIDANCE FOR THIS
TIME PD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 107 PM EDT TUE APR 21 2015
DEEP MIXING OF STRONGER WINDS HAS BEEN A BIT SLOW TO MATERIALIZE
AT KSBN...BUT STILL PLENTY TO CAUSE ISSUES. AT KFWA TAFS PRETTY
MUCH ON TRACK. WINDS WILL SUBSIDE THIS EVENING BUT STILL REMAIN
WESTERLY AND THEN PICK UP AGAIN ON WEDNESDAY. A FEW SHOWERS MAY
PASS NEAR EITHER AIRPORT THROUGH LATE AFTERNOON...BUT LITTLE
OVERALL IMPACT EXPECTED.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WIND ADVISORY UNTIL 8 PM EDT /7 PM CDT/ THIS EVENING FOR
INZ003>009-012>018-020-022>027-032>034.
MI...WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR MIZ077>081.
OH...WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR OHZ001-002-004-005-
015-016-024-025.
LM...SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 4 PM EDT
WEDNESDAY FOR LMZ046.
GALE WARNING UNTIL 8 PM EDT THIS EVENING FOR LMZ046.
SMALL CRAFT ADVISORY UNTIL 4 PM EDT WEDNESDAY FOR LMZ043.
&&
$$
UPDATE...FISHER
SYNOPSIS...AGD
SHORT TERM...AGD
LONG TERM...T
AVIATION...FISHER
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AREA FORECAST DISCUSSION
NWS TOPEKA KS
1247 PM CDT Tue Apr 21 2015
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 300 AM CDT TUE APR 21 2015
Deep upper low over the Great Lakes was making slow eastward
progress early this morning with likely a few small scale waves
rotating around it through the Northern and Central Plains. Periodic
mid cloud was present over the local area via isentropic upglide
from rather brisk and backed mid level winds. At least minor amounts
of EPV along the moist layer allowing some showers to form aloft,
with weak returns on radar showing some very light precip reaching
to the lower troposphere. HRRR and RAP runs quite similar to some
4km WRF runs with light precip forming over central Kansas in the
next few hours, with latest IR imagery indicating recent cloud
development there. All nearby 0Z soundings measured 850mb dewpoint
depressions around 12C, making measurable amounts hard to imagine in
this activity. A somewhat more unstable airmass develops over the
southeast quarter of Kansas this afternoon with weak surface
convergence. Will maintain small storm chances with still minor
isentropic lift and weak wave potential in place. The stronger wind
fields aloft could lead to some storm organization along with CAPE
around 500 J/kg and dry adiabatic low level lapse rates to produce a
very small threat for severe wind and hail in the mid afternoon to
early evening. Areas outside of storms could also see a few rather
strong wind gusts with mixing depths reaching 7000-10000ft AGL
though some veering remains through the column. The still dry
airmass and gusty winds lead to elevated fire danger in western
locations this afternoon.
Cold front via a stronger wave rotating around the low arrives this
evening and makes quick south progress through the state tonight.
Moisture, though modest, will continue to pool ahead of this front
for some storm chances through much of the night in the southern
zones, with typical diurnal trends allowing severe concerns to
diminish. Models are allowing the boundary layer to decouple fairly
quickly behind the front, but am somewhat skeptical of this given
the baroclinic zone they advertise. If winds can fall quicker than
expected, fairly clear skies could present a frost concern, but even
if they do the window of cold and calm conditions for formation
should be rather limited. Will mention patchy frost in far north
where concern is highest.
.LONG TERM...(Wednesday through Monday)
Issued at 300 AM CDT TUE APR 21 2015
Eastern Kansas remains on the southwest side of an upper surface
high for Wednesday, keeping high temperatures around 60 for most
of the area. Have kept rain chances out of the southern areas with
better chances south. Dry conditions continue Wednesday night into
Thursday, with lows in the upper 30s to near 40 and highs climbing
toward the middle 60s Thursday.
Upper pattern starts to shift Thursday night as shortwave ridge
noses out of the southern plains into our area, ahead of an upper
trof lifting northeast out of the four corners region. Initial
sensible weather impacts should be warmer lows in the 40s near 50
Thursday night with some showers possible after midnight as low
level jet makes a return over the area. Latest EC appears to be
trending toward the GFS solution for this shortwave as it moves
into the plains, taking a faster track and developing the warm
front from the surface low out into eastern or southeast Kansas.
GFS keeps the boundary south of the area and would make for cloudy
cool and rainy conditions area wide for Friday and Saturday night,
and with EC solutions also trending this way, have gone with
forecast as such.
Southern branch of the upper jet takes the shortwave trof east of
the area rather quickly on Saturday, with rain ending sometime
during the morning hours. Cooler high pressure once again noses
into the area behind the departing low and holds temperatures in
the low 60s, followed by overnight lows in the 40s. Highs on
Sunday rise a bit more into the middle 60s, and have kept rain
chances relegated to north and west while surface high continues
over the east. Another front progged to move across the area
Sunday night with northwest flow aloft returning on Monday.
Current forecast is for highs near 70, but this will depend on how
strong the front and wave are as to how much cooler air it does,
or does not, bring southward.
&&
.AVIATION...(For the 18Z TAFs through 18Z Wednesday Afternoon)
Issued at 1245 PM CDT TUE APR 21 2015
VFR conditions are expected the entire period with gusty winds
throughout the afternoon. Mid-level clouds will move south over the
area tonight as a frontal passage veers E winds N/NE after 04Z.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...65
LONG TERM...67
AVIATION...Heller
AREA FORECAST DISCUSSION
NWS PADUCAH KY
216 PM CDT TUE APR 21 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 215 PM CDT TUE APR 21 2015
NEAR TERM ON TRACK...AS CONVECTION CONTINUES TO TAKE SHAPE OVER
SOUTHERN INTO SOUTHEAST MISSOURI...LIGHTNING NOW OBSERVED WEST OF
OUR CWFA. WILL CONTINUE TO MONITOR FOR THE POSSIBILITY OF SOME
HAIL AND GUSTY WINDS GIVEN THE STEEP LAPSE RATES AND LOW FREEZING
LEVELS...DESPITE LACK OF LOW LEVEL MOISTURE. THE CHANCES WILL
CONTINUE THROUGH THE OVERNIGHT AS A BOUNDARY SETTLES SOUTH ACROSS
THE REGION. WILL DIMINISH POPS FROM NW TO SE WEDNESDAY MORNING...DRY
BY AFTERNOON. WILL KEEP IT DRY WEDNESDAY NIGHT THROUGH THURSDAY
WITH WEAK HIGH PRESSURE ANGLING IN FROM THE UPPER MIDWEST. CHANCES
OF SHOWERS MAY EXIST JUST SOUTH OF THE AREA NEAR OUR CWFA BORDER.
CAN ADJUST IF NEED BE. TEMPS A BLEND OF MOS AND EXISTING NUMBERS.
NAM HIGH RES AND HRRR A REASONABLE APPROACH FOR CONVECTIVE TRENDS
THROUGH 06Z.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 215 PM CDT TUE APR 21 2015
THE OPERATIONAL MODELS ARE TRYING TO FALL SOMEWHAT IN LINE WITH
PRIOR ENSEMBLE MEAN SOLUTIONS THROUGH SUNDAY. ALL IN ALL...
CONFIDENCE CONTINUES TO INCREASE FOR THE FIRST SYSTEM FRIDAY
THROUGH SATURDAY. UPPER TROF SHOULD EJECT NE INTO THE PLAINS BY
00Z SAT WITH MOISTURE QUICKLY SPREADING EAST BY FRIDAY AFTERNOON
AND EVENING. S/WV RIDGE AHEAD OF THE TROF NOT STRONG ENOUGH TO
WARD OFF ONCOMING SHRA/TSRA CHANCE. SO WE ARE ON THE AGGRESSIVE
SIDE OF THE ENVELOPE. LIKELY POPS STILL IN PLAY FOR FRIDAY NIGHT
WITH CHANCE TO LOW END LIKELY SATURDAY AS WELL...AS THE UPPER TROF
WEAKENS...AND THE REMNANT ENERGY TURNS ESE ACROSS THE AREA
SATURDAY...CONTINUING THE CHANCE OF CONVECTION. SURFACE BOUNDARY
SHOULD STAY JUST TO OUR SOUTH...SO ESSENTIALLY ELEVATED CONVECTION.
CHANCES TAIL OFF SATURDAY NIGHT WITH A DRY FORECAST IN PLACE FOR
SUNDAY. FOR MONDAY THROUGH TUESDAY...THE ENSEMBLE MEAN SOLUTIONS
WERE UTILIZED AND OPERATIONAL MODELS THROWN OUT. A HIGHLY COMPLEX
PATTERN IS FORECAST TO EVOLVE WITH SOME KIND OF A TROUGH EAST OF
THE PLAINS AND RIDGE WEST. HOWEVER THERE IS TOO MUCH VARIABILITY
IN THE DETAILS TO SIDE WITH ANY OPS SOLUTION AT THIS POINT. ITS
GOING TO CHANGE. WE FEE COMFORTABLE MAINTAINING LOW CHANCE POPS
FOR SHOWERS GIVEN THE UNSETTLED LOOK TO THE PATTERN. TEMPS WERE A
BLEND OF BASE MODEL OUTPUT AND EXISTING FORECAST NUMBERS.
&&
.AVIATION...
ISSUED AT 1225 PM CDT TUE APR 21 2015
FIRST ITEM OF CONCERN THIS FORECAST PERIOD IS THE GUSTY SOUTHWEST
WINDS. THEY WILL CONTINUE GUSTING UP TO AROUND 25 MPH AT TIMES FOR
THE REST OF THE AFTERNOON...WITH THE GUSTS SUBSIDING AFTER 00-02Z.
ALL INDICATIONS ARE THAT CONVECTION WILL DEVELOP AFTER 18Z AND
LAST THROUGH THE EVENING...WITH GREATEST PROBABILITIES OVER THE
KCGI/KPAH AREAS. ACTIVITY WILL BE RATHER SCATTERED...I.E. SHOULD
BE ABLE TO FLY AROUND...SO OPTED FOR JUST A VCTS. WILL UPGRADE TO
A TEMPO GROUP IF STORMS BECOME MORE ORGANIZED/WIDESPREAD. GUSTY
WINDS WILL BE POSSIBLE IN THE STRONGER STORMS. A FRONTAL BOUNDARY
WILL BE ADVANCING FROM THE NORTH LATER TONIGHT INTO EARLY TOMORROW
MORNING. THIS WILL BE FOCUS FOR MORE CONVECTION AND POSSIBLY LOWER
CIGS. THE FRONT WILL ALSO BRING A WIND SHIFT AROUND TO THE
WEST/NORTHWEST.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
352 PM EDT TUE APR 21 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 352 PM EDT TUE APR 21 2015
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW CLOSED UPR LO OVER
THE UPR LKS DOWNSTREAM OF HI AMPLITUDE UPR RDG OVER WRN NAMERICA.
COMBINATION OF DEEP CYC FLOW W TO NW FLOW AND INSTABILITY ENHANCED
BY DAYTIME HEATING UNDER ACCOMAPANYING THERMAL TROF /12Z H5 TEMP AT
GRB WAS -31C/ AND DEEP MSTR SHOWN ON THE 12Z RAOBS IS RESULTING IN
SCT-NMRS SN SHOWERS THAT ARE MIXED WITH RA IN THE WARMER LOCATIONS.
BUT COLDER CLD TOP TEMPS/MORE WIDESRPEAD SN SHOWERS ARE CONFINED
MAINLY TO NW ONTARIO/FAR NRN MN IN AREA WHERE MODELS INDICATE DEEP
QVECTOR CNVGC.
MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON POPS AND POTENTIAL SN
ACCUMS ASSOCIATED WITH DEEP CYC...MOIST NW FLOW ARND SLOW MOVING
CLOSED LO TO THE NE OF UPR MI.
CLOSED LO CENTERED OVER ERN LK SUP THIS AFTN IS FCST TO DRIFT SLOWLY
TO THE NE AND TO JUST S OF JAMES BAY ON WED. ALTHOUGH ACCOMPANYING
DEEP LYR QVECTOR CNVGC THAT IS SUPPORTING COLDER CLD TOPS TO THE NW
IS FCST TO REMAIN TO THE N OF UPR MI...PERSISTENT MOIST...CYC NW
FLOW ARND THIS FEATURE WL MAINTAIN AT LEAST CHC POPS OVER THE CWA
THRU WED...WITH THE LOWER POPS GENERALLY OVER THE SCENTRAL AND THE
HIER POPS OVER THE HIER TERRAIN OF THE NW WITH UPSLOPE WIND
COMPONENT. BUT LOSS OF DAYTIME HEATING TNGT WL CAUSE THE
CHARACTER OF THE SHOWER PATTERN TO TRANSITIONS FM ONE THAT SUPPORTS
THE HIER POPS OVER THE INTERIOR THIS AFTN TO A MORE WINTRY LES
LOOK TNGT. IN FACT...THE NW FLOW IS PROGGED TO ADVECT H85 TEMPS AS
LO AS -13 TO -14C OVER THE KEWEENAW BY 12Z WED...TEMPS LO ENUF TO
SUPPORT LES AND INCRS SN/WATER RATIOS ONCE THE EFFECT OF DAYTIME
INSOLATION HAS FADED. OVER THE HIER TERRAIN OF THE W...THERE WL
LIKELY BE SEVERAL INCHES OF WET SN ACCUM TNGT INTO WED MRNG EVEN IN
THE ABSENCE OF SGNFT LARGER SCALE FORCING. OPTED TO ISSUE AN SPS
TO ALERT THE PUBLIC TO THE POTENTIAL OF SOME SLUSHY SN ACCUMS ON
ROADS LATER THIS EVNG INTO WED MRNG. DAYTIME HEATING ON WED WL
BRING ABOUT A RETURN TO A MORE LAND BASED INSTABILITY SHOWER
PATTERN. BUT SOMEWHAT HIER HGTS/SHARPENING MID LVL INVRN FARTHER FM
THE SLOWLY DEPARTING CLOSED LO THAT RESTRICTS DESTABILIZATION WL
TEND TO LIMIT COVERAGE/INTENSITY OF THE SHOWERS AS COMPARED TO TODAY.
ALTHOUGH H85 TEMPS ARE FCST TO MODERATE TO -10C TO -12C...MAX TEMPS
ON WED WL HOLD IN THE 30S EXPECT WHERE SOME DOWNSLOPE WARMING AIDS
DIURNAL TEMP RECOVERY INTO THE LO 40S OVER THE SCENTRAL. THERE COULD
BE SOME RECORD LO MAX TEMPS ON WED.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 305 PM EDT TUE APR 21 2015
THE UPPER LOW THAT IS CURRENTLY AFFECTING THE AREA WILL SHIFT EAST
INTO THE CANADIAN MARITIMES SHORTLY AFTER THE START OF THE LONG TERM
PERIOD. THIS WILL LEAVE THE AREA BETWEEN THAT UPPER LOW AND AN UPPER
RIDGE IN THE CENTRAL/SOUTHERN PLAINS. THUS...THE AREA WILL BE UNDER
NORTHWESTERLY FLOW ALOFT FOR MOST DAYS THROUGH THE UPCOMING WEEKEND.
WITH A SURFACE RIDGE STRETCHING SOUTH FROM A HIGH IN NORTHERN CANADA
MOVING INTO THE AREA BY FRIDAY AND FRIDAY NIGHT...EXPECT DRIER AIR
TO GRADUALLY MOVE INTO THE REGION AND DIMINISH THE PRECIPITATION
POTENTIAL AND LEAD TO A DRY WEEKEND (ALTHOUGH THERE ARE HINTS OF A
WEAK DISTURBANCE BRINGING AN ISOLATED SHOWER TO THE FAR WESTERN U.P.
LATE FRIDAY NIGHT INTO SATURDAY MORNING). WITH THE MAIN UPPER LOW
SHIFTING EAST...TEMPERATURES WILL SLOWLY WARM BUT STILL STAY BELOW
NORMAL FOR LATE APRIL (AIDED BY THE LIGHT NORTHERLY FLOW OFF LAKE
SUPERIOR).
HEADING INTO NEXT WEEK...THE UPPER LOW CURRENTLY OVER THE GULF OF
ALASKA WILL MOVE INTO THE PACIFIC NORTHWEST OVER THE NEXT 24-48HRS
AND THEN INTO THE CENTRAL CONUS ON MONDAY. AS THE WAVE CONTINUES
EAST...IT WILL INTERACT WITH THE UPPER LOW NEAR THE CANADIAN
MARITIMES AND RE-ESTABLISH THE UPPER TROUGH OVER THE EASTERN CONUS.
THIS WILL KEEP BELOW NORMAL TEMPERATURES IN PLACE INTO NEXT WEEK AND
POSSIBLY LEAD TO SOME SHOWERS AROUND THE GREAT LAKES REGION.
OVERALL...FAIRLY COOL AND QUIET END TO APRIL WITH NO HAZARDOUS
WEATHER EXPECTED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 147 PM EDT TUE APR 21 2015
EXPECT SCT -SHSN...MIXED WITH RA AT THE WARMER SAW LOCATION...THIS
AFTN IN PERSISTENT CHILLY...MOIST AND GUSTY NW FLOW ARND LO PRES IN
ONTARIO ALONG WITH PREDOMINANT MVFR CONDITIONS. BEST CHC FOR SOME
HEAVIER SHSN/AT LEAST OCNL IFR CONDITIONS WL BE AT IWD WITH FVRBL
UPSLOPE FLOW. SAW HAS THE BEST CHC FOR VFR WX WITH A DOWNSLOPE WIND
COMPONENT. AS COLDER AIR ARRIVES TNGT...THE SHSN WL TEND TO INCREASE
IN COVERAGE AT CMX/IWD WITH USPLOPE NW WIND COMPONENT. PREDOMINANT
IFR TO OCNL MVFR VSBYS WL THE RULE AT THESE LOCATIONS INTO WED
MRNG...WHEN THE SHSN WL TEND TO BECOME MORE SCT AND ALLOW FOR
IMPROVING OVERALL CONDITIONS. DOWNSLOPE NATURE OF THE NW FLOW WL
LIMIT THE POTENTIAL FOR LOWER VSBYS AT SAW...BUT MVFR CIGS SHOULD
PREVAIL THERE WITH LINGERING LLVL MSTR.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 305 PM EDT TUE APR 21 2015
NORTHWESTERLY WINDS UP TO 30 KNOTS WILL CONTINUE OVER LAKE SUPERIOR
THROUGH THURSDAY MORNING. THERE COULD BE A FEW PERIODS OF GALE
FORCE GUSTS TO 35KTS LATE TONIGHT INTO WEDNESDAY...BUT THEY
SHOULDN/T BE WIDESPREAD. HIGH PRESSURE WILL BEGIN TO BUILD INTO
WESTERN LAKE SUPERIOR THURSDAY AFTERNOON/NIGHT AND LEAD TO
GRADUALLY DIMINISHING WINDS INTO FRIDAY. LIGHT NORTHERLY WINDS UP
TO 15KTS ARE EXPECTED THIS WEEKEND.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...SRF
AVIATION...KC
MARINE...SRF
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1236 PM CDT TUE APR 21 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM CDT TUE APR 21 2015
AN ARCTIC COLD FRONT ACROSS NORTH DAKOTA WILL BACK INTO THE FCST
AREA THIS AFTN PRODUCING SOME CLOUDINESS. THE FRONT WILL CONTINUE
TO MOVE SOUTH AND WEST TONIGHT. BY 12Z WEDNESDAY A SMALL AREA OF
HIGH PRESSURE HAS SETTLED OVER NCNTL NEB WHICH SHOULD PRODUCE
LOWS IN THE 20S. BY THIS TIME...THE MODELS SUGGEST ANY CLOUD
COVER WOULD LIE ACROSS THE PANHANDLE AND SOUTHWEST NEB WHICH
WOULD HOLD UP LOWS IN THE LOWER 30S.
HIGHS TODAY RISE INTO THE 60S AHEAD OF THE FRONT WITH 50S NORTH
OF THE FRONT ALONG HIGHWAY 20.
THE MIDLEVEL CLOUD COVER ACROSS CNTL/SERN NEB EARLY THIS MORNING
IS ASSOCIATED WITH 700MB FRONTOGENESIS. THE RAP MOVES THESE
CLOUDS SOUTHEAST AND THEN DROPS A SECOND BATCH OF CLOUDS INTO NRN
NEB AS EARLY AS 15Z WHICH HANG AROUND MOST OF THE DAY AND THEN
MOVE SOUTH AND WEST TONIGHT. THE RADAR RETURNS ACROSS NORTH
DAKOTA MOVE EAST OF THE FCST AREA IN THE NAM MODEL WHILE THE HRRR
SHOWS TOO MUCH DRY AIR IN THE LOWER LEVELS FOR ANYTHING MORE THAN
SPRINKLES THIS AFTN AND TONIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 355 AM CDT TUE APR 21 2015
SURFACE HIGH PRESSURE QUICKLY FOLLOWS THE COLD FRONT AND WILL
SLIDE SOUTHEAST OF THE AREA EARLY IN THE DAY ON WEDNESDAY WITH
SOUTHERLY WINDS DEVELOPING. DESPITE SOUTHERLY WINDS...COOL AIR
ALOFT...850 TEMP FROM 3C EAST TO 8C WEST...AND EVEN WITH SUN AND
GOOD MIXING...HIGHS IN THE UPPER 50S AND LOWER 60S. MEANWHILE AN
UPPER LEVEL LOW LIFTS TOWARDS THE DESERT SW. MODELS ALSO SHOW A
WEAK SYSTEM AHEAD OF THE MAIN LOW...PUSHING ACROSS THE SOUTHERN
PLAINS.
A SECOND WAVE EJECTS FROM THE MAIN LOW AND ARRIVES TO THE
SOUTHERN/CENTRAL PLAINS WED NIGHT INTO THURSDAY. MARGINAL LIFT
INTO SW NEB MAY RESULT IN A FEW LIGHT SHOWERS INITIALLY. A BETTER
CHANCE ARRIVES LATER IN THE DAY ON THURSDAY AFTER WE GET SOME
HEATING. MODELS INCREASE CAPES TO A FEW 100 J/KG AND LIFTED INDEX
VALUES AROUND ZERO OR SLIGHTLY NEG. GENERALLY THING ACTIVITY WILL
BE SOME SHOWERS AND A FEW RUMBLES OF THUNDER HERE OR THERE.
BY FRIDAY THE MAIN LOW WILL BE CROSSING THE ROCKIES. MOISTURE
CONTINUES TO INCREASE AHEAD OF THE LOW AND FRIDAY LOOKS TO SEE A
WAVE OR TWO OF SHOWERS TO ROTATE THROUGH THE AREA. BETTER
MOISTURE LIFT ASSOCIATED CLOSER TO THE LOW...WHICH FAVORS HIGHER
POPS ACROSS SW NEB.
A SECOND WAVE...CLIPPER...QUICKLY FOLLOWS FOR THE WEEKEND. SHOULD
SEE A BRIEF BREAK IN THE ACTIVITY BEFORE THE SECOND WAVE
ARRIVES...ALTHOUGH TIMING THE BREAK IS DIFFICULT DUE TO MODEL
DIFFERENCES. FORECAST DOES RETAIN LOW POPS AND EXPECT THIS TO
CHANGE IN THE COMING DAYS AS THE LULL IN ACTIVITY BECOMES MORE
CLEAR. AT THIS TIME MODELS ARE IN FAVOR OF THE DRY PERIOD TO
OCCUR SOMETIME SATURDAY...EARLIEST IS THE GEM/GFS...WHILE LATER
IS FAVORED BY THE ECMWF.
THE NEXT WAVE SHOULD BE EAST OF THE AREA TO START THE WORK WEEK
DRY AND MILD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1235 PM CDT TUE APR 21 2015
A WEAK COLD FRONT WILL SLOWLY DROP THROUGH THE AREA THIS
AFTERNOON...SWITCHING WESTERLY WINDS TO THE NORTH. WITH GOOD
MIXING...NORTH TO NORTHWEST WINDS WILL BE 20-25 KTS AND GUSTY.
OTHERWISE...VFR CONDITIONS WILL PREVAIL THROUGH WEDNESDAY MORNING.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...UNR-SR
AREA FORECAST DISCUSSION
NWS MEDFORD OR
257 PM PDT TUE APR 21 2015
.SHORT TERM...VISIBLE SATELLITE SHOWS THE ATMOSPHERE HAS
DESTABILIZED AS EXPECTED WITH NUMEROUS CUMULUS BUILDUPS OVER THE
HIGHER TERRAIN AND EAST SIDE. RADAR IS ALREADY SHOWING RETURNS IN
EASTERN SISKIYOU, NORTHERN KLAMATH, AND CENTRAL LAKE COUNTIES.
THERE HAS EVEN BEEN A STRIKE OR TWO RECORDED IN EASTERN SISKIYOU
COUNTY JUST WEST OF TENANT. AND NUMEROUS STRIKES RECORDED JUST
SOUTH OF THE CWA IN LASSEN COUNTY. HI- RES, NEAR TERM MODELS LIKE
THE HRRR (HIGH RESOLUTION RAPID REFRESH) SHOW MOST OF THE ACTION
OVER MODOC, LAKE, AND FAR EASTERN KLAMATH COUNTIES LATER THIS
AFTERNOON. STEERING WINDS ARE FAIRLY LIGHT SO THESE STORMS WILL
LIKELY BE SLOW MOVERS RESULTING IN THE POTENTIAL FOR SOME HEAVIER
DOWNPOURS UNDER THE CORE OF THESE STORMS. ALSO EXPECT SOME GUSTY
OUTFLOW WINDS WITH THE STRONGER STORMS ALONG WITH THE POTENTIAL
FOR SMALL HAIL. MODELS CONTINUE TO SHOW THE ATMOSPHERE STABILIZING
WITH THE LOSS OF DIURNAL HEATING SO CONVECTION SHOULD DIMINISH BY
TONIGHT. THE ATMOSPHERE WEST OF THE CASCADES IS MORE STABLE WITH
WEAKER LAPSE RATES SO NOT EXPECTING ANY THUNDERSTORMS FOR THAT
AREA.
ASIDE FROM THE RAIN EXPECTED WITH THE CONVECTION PREVIOUSLY MENTIONED,
MOST AREAS WILL REMAIN DRY WITH THE PASSAGE OF THE COLD FRONT.
WINDS WILL BE QUITE BREEZY THROUGH THE AFTERNOON IN RESPONSE TO
THIS COLD FRONT MOVING THROUGH THE AREA. THE UPPER LEVEL TROUGH
MOVES THROUGH OVERNIGHT INTO TOMORROW AND DRIER, MORE STABLE AIR
MOVES IN BEHIND IT FOR WEDNESDAY. WEAK RIDGING STARTS TO BUILD
OVER THE AREA WEDNESDAY NIGHT, BUT THIS IS SHORT LIVED AS A WEAK
TROUGH APPROACHES THE AREA THURSDAY MORNING. THERE IS A CHANCE FOR
SOME SHOWERS THURSDAY AFTERNOON, BUT THIS LOOKS MOSTLY CONFINED
FROM THE UMPQUA DIVIDE AND NORTH.
AN UPPER LOW MOVES IN OVER BRITISH COLUMBIA THURSDAY EVENING AND
SHORTWAVES ROTATING AROUND IT CONTINUE THE CHANCE FOR PRECIPITATION
FOR MOST OF THE AREA THROUGH SATURDAY MORNING.
.LONG TERM...SATURDAY THROUGH TUESDAY...THE OPERATIONAL EC AND
GFS ARE IN SIMILAR AGREEMENT WITH THE OVERALL PATTERN FRIDAY INTO
NEXT WEEKEND. HOWEVER THERE IS DISAGREEMENT WITH THE PLACEMENT AND
STRENGTH OF THE UPPER LOW FRIDAY. THE EC IS STRONGER AND FURTHER
SOUTH WITH THE UPPER LOW AND WETTER. HAVE KEPT IN A CHANCE OF
SHOWERS FOR MOST OF THE FORECAST AREA...THOUGH RAIN AND MOUNTAIN
SNOW AMOUNTS SHOULD BE LIGHT. THE TROUGH AXIS SHIFTS EAST FRIDAY
NIGHT AND RIDGING WILL ATTEMPT TO MOVE IN FROM THE SOUTHWEST. THE
GFS SHOWS MORE OF A DIRTY RIDGE SCENARIO WITH WARM FRONTAL
PRECIPITATION MOVING INTO THE AREA. THE EC HAS A MORE PRONOUNCED
RIDGE AND THUS SHOWS A DRY AND MILDER SOLUTION. SUSPECT THE WARM
FRONTAL PRECIPITATION IS OVERDONE, BUT DID NOT WANT TO DISCOUNT IT
COMPLETELY, SO WITH WITH A BLEND BETWEEN THE EC AND GFS WITH A
SLIGHTLY DRIER BIAS.
A DIRTY RIDGE REMAIN OVER THE AREA SUNDAY WITH THE BEST CHANCE FOR
PRECIPITATION OVER THE NORTHERN PART OF THE CWA. ESPECIALLY WEST OF
THE CASCADES AND NORTH OF THE UMPQUA DIVIDE.
SIGNIFICANT UPPER TROUGHING THAT`S BEEN HANGING OVER THE NORTHEAST
PACIFIC FINALLY REACHES THE FORECAST AREA WITH SIGNIFICANT RAIN
POTENTIALLY MONDAY INTO TUESDAY. THAT SAID...THERE IS SOME
UNCERTAINTY AS TO WHEN THIS TROUGHING REACHES THE AREA. ENSEMBLE
MEMBERS ARE OUT OF PHASE...BUT NOT AS MUCH AS YESTERDAY WITH THE
TROUGH AXIS STARTING TO DROP SOUTH. IN CONTRAST, THE OPERATIONAL EC
SHOWS MORE OF A SPLIT FLOW PATTERN NEAR 150 W AND MORE RIDGING IN
OUR AREA, THUS DELAYING ANY SIGNIFICANT PRECIPITATION.
IN SHORT...CONFIDENCE IS LOW TO MODERATE IN THE EXTENDED PERIOD AND
DID NOT MAKE ANY SIGNIFICANT CHANGES.
&&
.AVIATION...FOR THE 21/18Z TAF CYCLE...MVFR CONDITIONS WITH TERRAIN
OBSCURATIONS ARE EXPECTED FROM THE UMPQUA BASIN AND COASTAL
MOUNTAINS WESTWARD INTO TONIGHT. FURTHER INLAND GUSTY NORTHWEST
WINDS WILL DEVELOP THIS AFTERNOON THROUGH THIS EVENING WITH
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS EXPECTED FROM THE
OREGON CASCADES AND CALIFORNIA TRINITY ALPS EASTWARD. IT`S POSSIBLE
THUNDERSTORMS COULD RESULT IN TEMPORARY MVFR CIGS WITH MOUNTAINS
PARTLY OBSCURED BETWEEN 23Z AND 04Z. -PETRUCELLI
&&
.MARINE...UPDATED 300 PM PDT TUESDAY APR 21, 2015...HIGH PRESSURE
WILL BUILD INTO THE AREA TONIGHT BUT THIS WILL RESULT IN GUSTY NORTH
WINDS AND STEEP TO VERY STEEP SEAS. GALES AND WARNING LEVEL SEAS ARE
EXPECTED AT TIMES SOUTH OF CAPE BLANCO TONIGHT THROUGH WEDNESDAY
NIGHT. THURSDAY THROUGH THE WEEKEND...A SERIES OF FRONTAL SYSTEMS IS
LIKELY TO MOVE THROUGH WITH BUILDING SWELL. NORTHWEST WINDS
WEDNESDAY NIGHT THROUGH FRIDAY ARE EXPECTED TO BECOME SOUTHWESTERLY
THIS WEEKEND. SPILDE
&&
.FIRE WEATHER....FIRE WEATHER...UPDATED 3 PM PDT TUESDAY, APRIL
21ST, 2015... THE ATMOSPHERE IS ALREADY STARTING TO BECOME
UNSTABLE AHEAD OF A RATHER SHARP, BUT NOT STRONG, INCOMING TROUGH
OF LOW PRESSURE. A FEW ISOLATED STORMS HAVE DEVELOPED IN NORTHERN
CAL AND NORTHERN KLAMATH COUNTY NORTHEAST OF CHEMULT. THE LATEST
HRRR REFLECTIVITY PRODUCT SHOWS MOST OF THE ACTIVITY DEVELOPING IN
NORTHERN CAL, THEN MIGRATING NORTH INTO PARTS OF LAKE AND KLAMATH
COUNTIES LATE THIS AFTERNOON THROUGH THIS EVENING. UNLIKE THE HIGH
IMPACT LIGHTNING EVENTS THAT SOMETIMES AFFECT OUR REGION MAINLY IN
THE SUMMER, FORCING WITH THE INCOMING SYSTEM IS WEAK IN THAT THERE
IS NO CLEAR COLD POOL MOVING THROUGH. INSTEAD, A WEAK SURFACE
FRONT IS EXPECTED TO DEVELOP ALONG AND NEAR THE CASCADES THIS
AFTERNOON. THIS SHOULD GIVE RISE TO BUILD-UPS ALONG AND NEAR THE
TRINITY ALPS AND CASCADE CREST THIS AFTERNOON, SHIFTING EASTWARD
TO THE LEE OF THE CASCADES TOWARDS THE EVENING. CONDITIONS ARE
MOST FAVORABLE FOR SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS IN
THESE LEE AND EAST SIDE AREAS. MOST GUIDANCE FOCUSES ACTIVITY THIS
EVENING IN THE WARNER MOUNTAINS OF LAKE COUNTY AND ANOTHER IN
NORTHERN LAKE COUNTY THIS EVENING. WHILE FIRE DANGER DID REACH
HIGH IN PORTIONS OF THE MODOC ON MONDAY, FORECAST FIRE DANGER FOR
TODAY IS MODERATE. ADDITIONALLY, DEPARTURE FROM AVERAGE GREENNESS
IS SPOTTY IN TERMS OF DEFICITS, SO SUSPECT THERE`S SOME GREEN-UP
COMPONENT TO THE LIVE FUELS NOW. MODELS INDICATE THAT ANY STORMS
THAT DO GET GOING WILL PRODUCE GUSTY OUTFLOW WINDS MAINLY IN THE
20 TO 30 MPH RANGE, BUT ALSO SOME MEASURABLE RAINFALL. THUS,
DESPITE UNUSUALLY DRY CONDITIONS DUE TO THE ONGOING DROUGHT, WE
HAVE DECIDED THAT THIS EVENT DOES NOT WARRANT ANY WARNINGS.
INSTEAD, A HEADS-UP TYPE OF HEADLINE WILL BE MAINTAINED IN THE
FORECAST. BTL/PETRUCELLI
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS UNTIL 5 AM PDT THURSDAY FOR
PZZ350-356-370-376.
HAZARDOUS SEAS WARNING UNTIL 5 AM PDT THURSDAY FOR PZZ356-376.
GALE WARNING UNTIL 5 AM PDT THURSDAY FOR PZZ356-376.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 5 AM PDT THURSDAY
FOR PZZ350-356-370-376.
$$
MND/MAP/MAS
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
344 PM CDT TUE APR 21 2015
.SHORT TERM...
SURFACE DEWPOINTS HAVE BEEN FAIRLY STAGNANT ACROSS THE FORECAST AREA
TODAY AS MODEST ADVECTION BALANCES MIXING. AT 3 PM...SATELLITE
IMAGERY SHOWED A DEVELOPING CUMULUS FIELD IN EASTERN NEW MEXICO
WHERE THE DEWPOINTS ARE MOSTLY IN THE 30S. MORE EXTENSIVE
DEVELOPMENT WAS ONGOING ACROSS THE SACRAMENTOS AND SANGRES OF NM.
THE HRRR HAS BEEN FAIRLY CONSISTENT WITH BRINGING SOME OF THIS
ACTIVITY EASTWARD ACROSS THE WESTERN AND CENTRAL SOUTH PLAINS LATE
THIS AFTERNOON AND EVENING...ALTHOUGH IT IS ABOUT THE ONLY MODEL TO
DO SO. FCST SOUNDINGS IN THESE AREAS INDICATE ANY STORMS THAT DO
DEVELOP WILL BE HIGH-BASED HAVE LITTLE CAPE TO WORK WITH...SO THEY
WILL ONLY BE CAPABLE OF SPOTTY RAIN AND STRONG WIND GUSTS. IF ANY
STORMS CAN SURVIVE FARTHER TO THE EAST THIS EVENING AND ENCOUNTER
THE DEEPER MOISTURE...IT IS NOT OUT OF THE QUESTION THAT A HAIL
THREAT COULD DEVELOP...BUT THIS APPEARS UNLIKELY AT THIS TIME.
TONIGHT...THE LOW LEVEL JET WILL BRING RICHER MOISTURE NWWD INTO
WEST TEXAS...WITH THE SURFACE DRYLINE RETREATING THROUGH MOST IF NOT
ALL OF THE CWA...PERHAPS HOLDING BACK ACROSS THE FAR SW TX
PANHANDLE. NAM FCST SNDGS SHOW FOG POTENTIAL ACROSS THE SOUTHERN AND
CENTRAL SOUTH PLAINS BY EARLY WED MORNING SO WE HAVE ADDED A PATCHY
MENTION IN THE GRIDS....SOME AREAS OF LOW STRATUS ARE POSSIBLE AS
WELL. MEANWHILE TO OUR NORTH ACROSS THE PANHANDLES...THEY WILL
LIKELY SEE SOME OVERNIGHT TSTM ACTIVITY COINCIDING WITH A SWD-MOVING
COLD FRONT. IT IS UNCERTAIN WHAT IMPACT STORM COLD POOLS MAY HAVE ON
THE PROGRESS OF THE FRONT...WHICH TENDS TO LOWER OUR CONFIDENCE ON
HOW THE FRONT/OUTFLOW BOUNDARY WILL BEHAVE ON WEDNESDAY. IN
GENERAL...WE EXPECT THE BOUNDARY TO SINK SOUTH THROUGH THE FAR SRN
PANHANDLE AND POSSIBLY INTO THE NORTHERN ROLLING PLAINS. BACK TO THE
WEST...THE DRYLINE SHOULD FORM UP AND MOVE EAST AS A SURFACE TROUGH
DEVELOPS FROM EASTERN NM INTO THE ROLLING PLAINS. ALTHOUGH WE HAVE
TO STRESS A LARGE UNCERTAINTY IN THE PARTICULARS...A TRIPLE-POINT
MAY DEVELOP SOMEWHERE FROM OUR CENTRAL TO SOUTHEAST COUNTIES. BACKED
FLOW AND HIGH SURFACE MOISTURE WILL BE POSSIBLE ACROSS AT LEAST OUR
NE ZONES. WITH A MID-LVL SHORTWAVE PASSING ACROSS THE AREA DURING
THE DAY...STRONG INSTABILITY AND DEEP SHEAR IS LIKELY TO DEVELOP
ALONG AND TO THE NORTH AND EAST OF THE TRIPLE-POINT. GUIDANCE
GENERALLY SHOWS A STRONG CONVECTIVE SIGNAL IN THIS AREA BY LATE
AFTERNOON...ALTHOUGH WITH A LOT OF SPREAD RECORDING THE AREA
POTENTIALLY IMPACTED. WHERE STORMS OCCUR...SEVERE WEATHER WILL BE A
STRONG POSSIBILITY...INCLUDING THE POSSIBILITY OF TORNADOES
DEPENDING THE ORIENTATION/EVOLUTION ON THE BOUNDARY/S/. FARTHER
WEST...WE HAVE TRIMMED POPS DOWN OUR NEAR THE STATE LINE BUT LEFT A
SLIGHT CHANCE GOING ACROSS MUCH OF THE SOUTH PLAINS IN CASE THE
DRYLINE IS FARTHER WEST THAN ANTICIPATED.
.LONG TERM...
THE PATTERN THEME THROUGH EARLY NEXT WEEK REMAINS THAT OF A
PROGRESSIVE ONE AS A SERIES OF SOUTHERN STREAM TROUGHS IMPACT THE
REGION. ONLY UNTIL THEREAFTER DOES THE PATTERN SHOW SIGNS OF
TRENDING MORE STAGNANT IN THE FORM OF MID-CONUS LONGWAVE RIDGING.
ALL DAYS CONSIDERED...WEDNESDAY EVENING LOOKS TO GRAB THE LIMELIGHT
FOR SENSIBLE WEATHER AS A SEVERE CONVECTIVE EPISODE SHOULD BE WELL
UNDERWAY. LOCATION OF THIS EVENT WILL BE HIGHLY DEPENDENT ON A
STATIONARY FRONT CURRENTLY PROGGED TO BISECT OUR CWA FROM NW-SE BY
LATE EVENING...THOUGH MODELS CONTINUE TO FAVOR OUR NERN COUNTIES.
BACKGROUND FORCING APPEARS RATHER SUBDUED AND LINKED MOSTLY TO A
SHORTWAVE TROUGH CRESTING SHALLOW RIDGING ALOFT AND A NORTHWARD PUSH
OF STRONGER SUBTROPICAL WINDS. THIS ALONG WITH FAVORABLE DEEP SHEAR
MAY SERVE TO KEEP CONVECTIVE MODES RESTRICTED TO ISOLATED OR
SCATTERED SUPERCELLS. FEEL 40-50 PERCENT POPS WED EVENING ARE
REPRESENTATIVE OF THIS SCENARIO FOR NOW BEFORE PRECIP EVENTUALLY
MOVES DOWNSTREAM LATE WED NIGHT.
BEYOND WEDNESDAY NIGHT...THE WAVERING FRONTAL BOUNDARY SHOULD LIFT
NORTH AS A WARM FRONT IN ADVANCE OF A MORE ROBUST TROUGH LIFTING OUT
OF THE DESERT SOUTHWEST. THIS WAVE WILL PROJECT EVEN STRONGER WINDS
ATOP THE REGION PERHAPS ACCOMPANIED BY OCCASIONAL IMPULSES AND
SLIGHT CHANCE POPS...ESPECIALLY OFF THE CAPROCK WHERE LL MOISTURE
WILL HAVE A GREATER RESIDENCE TIME. MODEL CONSENSUS IS FOR DRY
SLOTTING TO SURGE ATOP THE CAPROCK COUNTIES BY EARLY FRIDAY AND
QUICKLY SWEEP EAST AS THE BASE OF THE TROUGH LIFTS TO OUR NORTH.
THE TIMING AND PATH OF THIS TROUGH SUGGEST A WINDY DAY IS IN STORE
YET WE REMAIN A BIT RELUCTANT TO BITE ON THE STRONG WINDS AS
PROGGED BY THE GFS AT TIMES. TIME-HEIGHT X-SECTIONS SHOW NEXT TO
NIL CIRRUS...SO WE MAY NEED TO RATCHET UP OUR 20-30 MPH WINDS
EVEN FURTHER IN LATER FORECASTS IF THIS THEME PERSISTS.
BY SATURDAY...QUIETER WEATHER UNDER TRANSIENT RIDGING WILL BE
REPLACED BY ONE FINAL TROUGH AT SOME POINT ON SUNDAY AHEAD OF
MODIFIED CANADIAN AIR WHICH LOOKS TO DIVE INTO THE GULF COME
MONDAY. PRECIP MERIT FROM SUN-SUN NIGHT DOESN/T SHOW MUCH
SUBSTANCE AMONG THE LATEST GLOBAL MODELS...SO POPS WERE SCALED
BACK IN COVERAGE TO BETTER MATCH THE DRIER SUPERBLEND AND
CONSENSUS ROUTES.
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
33/93
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
114 PM CDT TUE APR 21 2015
.AVIATION...
/18Z TAFS/
MVFR CIGS BETWEEN DRT AND SAT/SSF/AUS SHOULD CONTINUE TO LIFT AND
STAY CLEAR OF OUR TAF SITES THIS AFTERNOON. SOUTHEAST FLOW FROM
THE GULF HAS RETURNED...WHICH COMBINED WITH WEAK LIFT WILL LEAD
TO CIGS LOWERING TO MVFR AROUND 3-4Z AND IFR AROUND 8Z AT ALL TAF
SITES. MODEL GUIDANCE SUGGESTS LIFR CIGS WITH TEMPO VLIFR CIGS ARE
POSSIBLE TONIGHT AT SAT/SSF/DRT...BUT HELD OFF PREVAILING THAT FOR
NOW. ISOLATED -SHRA IS POSSIBLE TONIGHT WITH A STRENGTHENING LLJ
AND -TSRA IS POSSIBLE TOMORROW AFTERNOON...BUT CAPPING ALOFT WILL
LIKELY KEEP COVERAGE TOO ISOLATED TO MENTION IN TAFS.
LH
&&
.PREV DISCUSSION... /ISSUED 1201 PM CDT TUE APR 21 2015/
UPDATE...
INCREASING CLOUD COVER HAS KEPT TEMPERATURES DOWN SLIGHTLY FROM
FORECAST. THIS TREND WILL CONTINUE AS SOUTHERLY LOWER LEVEL FLOW
INCREASES MOISTURE. HAVE LOWERED HIGH TEMPERATURES A COUPLE OF
DEGREES IN MANY AREAS FOR THIS AFTERNOON. ALSO...DUE TO UPPER
LEVEL RIDGE BUILDING IN FROM THE SOUTH WILL SERVE TO INCREASE
CONVECTIVE INHIBITION. AS A RESULT...WILL REMOVE MENTION OF
THUNDER. HOWEVER...WILL MAINTAIN SHOWERS AS RADAR IS SHOWING A
BAND OF SHOWERS STREAMING INTO TOWARD OUR AREA FROM THE SOUTH.
PREV DISCUSSION... /ISSUED 652 AM CDT TUE APR 21 2015/
AVIATION...
/12Z TAFS/
CLEAR SKIES ARE IN PLACE AS UPPER LEVEL MOISTURE PUSHES TO THE
EAST AND LIGHT WINDS FROM THE NORTHWEST AND NORTHEAST DOMINATE AT
THE SURFACE. HOWEVER...THIS CONDITION IS FORECAST TO QUICKLY
CHANGE THIS MORNING AS SOUTHERLY WINDS RETURN. MVFR CONDITIONS ARE
EXPECTED ACROSS KSAT AND KSSF AROUND 14Z TO 16Z AS A POCKET OF LOW
CLOUDS FORM ACROSS THE SAN ANTONIO METRO AREA. CLOUDS WILL
INCREASE THROUGHOUT THE DAY AS GULF MOISTURE PUSHES NORTHWARD FOR
THE RETURN OF MVFR CONDITIONS ACROSS AREA SITES THIS EVENING. AREA
SOUNDINGS AND MOS GUIDANCE ARE SUGGESTING CIGS TO LOWER TO
IFR/LIFR OVERNIGHT AS SATURATED AIR DOMINATES THE AREA. WINDS WILL
BE FROM THE SOUTHEAST FOR THE MOST PARTS WITH SPEEDS OF 10 KNOTS
AND GUSTING UP TO 21 KNOTS ACROSS KDRT THIS AFTERNOON.
PREV DISCUSSION... /ISSUED 442 AM CDT TUE APR 21 2015/
SHORT TERM (TODAY THROUGH WEDNESDAY)...
A WEAK UPPER LEVEL DISTURBANCE MOVED OVER THE AREA OVERNIGHT AND
CLEARING SKIES ARE LEFT IN ITS WAKE. THE CLEARING SHOULD BE
TEMPORARY AS A MOIST LAYER AT 850 HPA SHOULD SATURATE IN MANY
AREAS. THE CLOUDS WILL PROBABLY BE SCT VARIABLE TO BKN SINCE THE
MOISTURE LAYER APPEARS THIN. THUS WILL GO WITH SLIGHTLY ABOVE
BLENDED GUIDANCE HIGHS TODAY. RAP SOUNDINGS SUGGEST A BREAKABLE
CAP SHOULD THERE BE ENOUGH MOISTURE SO WILL CONTINUE WITH ISOLATED
POPS. AN UPPER LOW CURRENTLY OVER SOUTHERN CA WILL CONTINUE TO
CARVE DEEPER OVER THE BAJA PENINSULA THROUGH WEDNESDAY. DEEPENING
MOISTURE WILL LEAD TO INCREASED RAIN CHANCES AND A FEW STRONG
STORMS AND POSSIBLE SUPERCELLS AS NOTED IN THE SPC DAY 2 OUTLOOK.
LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)...
A FAIRLY LIGHT LOW LEVEL FLOW WEDNESDAY NIGHT INTO THURSDAY MEANS
THAT THERE COULD BE SOME REMNANT OUTFLOW BOUNDARIES LEFT FROM
WEDNESDAY STORMS TO BRING ADDITIONAL STORM FOCUS FOR THURSDAY AS
THE UPPER LOW BEGINS TO LIFT INTO THE SOUTHERN ROCKIES. HIGHEST
POPS OF THE WEEK ARE THUS SAVED FOR THURSDAY NIGHT INTO FRIDAY.
THE EJECTION OF THE LOW INTO A SHALLOW TROUGH LEAVES SOME COVERAGE
UNCERTAINTIES THIS FAR SOUTH...SO DO NOT WANT TO OVER-ADVERTISE
THE SEVERE THREAT BEYOND A NOD IN THE HWO. POPS SHOULD LOWER
SATURDAY INTO SUNDAY AS FLAT RIDGING ALOFT RETURNS. MOISTURE IS
SUFFICIENT FOR STORMS...BUT EXPECT A STRONGER CAPPING INVERSION.
ANOTHER LOW LATITUDE UPPER DISTURBANCE IS FORECAST BY THE GFS TO
BRING RAIN AND STORMS BY MIDWEEK...BUT WILL KEEP WITH THE MORE
CONSERVATIVE ECMWF UNTIL THE PATTERN DIFFERENCES BETWEEN MODELS
DECREASE. TEMPERATURES THROUGH THE PERIOD SHOULD CONTINUE TO BE
SEASONAL. A WEAK FRONT EXPECTED SATURDAY WILL PROBABLY ADD TO
DAYTIME TEMPERATURES THROUGH REDUCED CLOUDINESS.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 80 66 82 69 86 / 10 20 40 20 20
AUSTIN BERGSTROM INTL AIRPORT 79 66 81 68 85 / 10 20 40 30 20
NEW BRAUNFELS MUNI AIRPORT 79 66 82 69 87 / 10 20 40 20 20
BURNET MUNI AIRPORT 77 66 81 68 85 / 10 20 30 20 20
DEL RIO INTL AIRPORT 81 67 86 70 88 / 10 30 20 10 20
GEORGETOWN MUNI AIRPORT 79 67 82 68 86 / 10 20 40 30 20
HONDO MUNI AIRPORT 80 67 82 69 87 / 10 30 30 10 20
SAN MARCOS MUNI AIRPORT 78 66 81 68 85 / 10 20 40 20 20
LA GRANGE - FAYETTE REGIONAL 79 66 82 70 85 / 10 20 40 30 20
SAN ANTONIO INTL AIRPORT 79 68 82 71 86 / 10 20 30 20 20
STINSON MUNI AIRPORT 81 68 82 71 87 / 10 20 30 10 20
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...01
SYNOPTIC/GRIDS...04
PUBLIC SERVICE/DATA COLLECTION...12
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1201 PM CDT TUE APR 21 2015
.UPDATE...
INCREASING CLOUD COVER HAS KEPT TEMPERATURES DOWN SLIGHTLY FROM
FORECAST. THIS TREND WILL CONTINUE AS SOUTHERLY LOWER LEVEL FLOW
INCREASES MOISTURE. HAVE LOWERED HIGH TEMPERATURES A COUPLE OF
DEGREES IN MANY AREAS FOR THIS AFTERNOON. ALSO...DUE TO UPPER
LEVEL RIDGE BUILDING IN FROM THE SOUTH WILL SERVE TO INCREASE
CONVECTIVE INHIBITION. AS A RESULT...WILL REMOVE MENTION OF
THUNDER. HOWEVER...WILL MAINTAIN SHOWERS AS RADAR IS SHOWING A
BAND OF SHOWERS STREAMING INTO TOWARD OUR AREA FROM THE SOUTH.
&&
.PREV DISCUSSION... /ISSUED 652 AM CDT TUE APR 21 2015/
AVIATION...
/12Z TAFS/
CLEAR SKIES ARE IN PLACE AS UPPER LEVEL MOISTURE PUSHES TO THE
EAST AND LIGHT WINDS FROM THE NORTHWEST AND NORTHEAST DOMINATE AT
THE SURFACE. HOWEVER...THIS CONDITION IS FORECAST TO QUICKLY
CHANGE THIS MORNING AS SOUTHERLY WINDS RETURN. MVFR CONDITIONS ARE
EXPECTED ACROSS KSAT AND KSSF AROUND 14Z TO 16Z AS A POCKET OF LOW
CLOUDS FORM ACROSS THE SAN ANTONIO METRO AREA. CLOUDS WILL
INCREASE THROUGHOUT THE DAY AS GULF MOISTURE PUSHES NORTHWARD FOR
THE RETURN OF MVFR CONDITIONS ACROSS AREA SITES THIS EVENING. AREA
SOUNDINGS AND MOS GUIDANCE ARE SUGGESTING CIGS TO LOWER TO
IFR/LIFR OVERNIGHT AS SATURATED AIR DOMINATES THE AREA. WINDS WILL
BE FROM THE SOUTHEAST FOR THE MOST PARTS WITH SPEEDS OF 10 KNOTS
AND GUSTING UP TO 21 KNOTS ACROSS KDRT THIS AFTERNOON.
PREV DISCUSSION... /ISSUED 442 AM CDT TUE APR 21 2015/
SHORT TERM (TODAY THROUGH WEDNESDAY)...
A WEAK UPPER LEVEL DISTURBANCE MOVED OVER THE AREA OVERNIGHT AND
CLEARING SKIES ARE LEFT IN ITS WAKE. THE CLEARING SHOULD BE
TEMPORARY AS A MOIST LAYER AT 850 HPA SHOULD SATURATE IN MANY
AREAS. THE CLOUDS WILL PROBABLY BE SCT VARIABLE TO BKN SINCE THE
MOISTURE LAYER APPEARS THIN. THUS WILL GO WITH SLIGHTLY ABOVE
BLENDED GUIDANCE HIGHS TODAY. RAP SOUNDINGS SUGGEST A BREAKABLE
CAP SHOULD THERE BE ENOUGH MOISTURE SO WILL CONTINUE WITH ISOLATED
POPS. AN UPPER LOW CURRENTLY OVER SOUTHERN CA WILL CONTINUE TO
CARVE DEEPER OVER THE BAJA PENINSULA THROUGH WEDNESDAY. DEEPENING
MOISTURE WILL LEAD TO INCREASED RAIN CHANCES AND A FEW STRONG
STORMS AND POSSIBLE SUPERCELLS AS NOTED IN THE SPC DAY 2 OUTLOOK.
LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)...
A FAIRLY LIGHT LOW LEVEL FLOW WEDNESDAY NIGHT INTO THURSDAY MEANS
THAT THERE COULD BE SOME REMNANT OUTFLOW BOUNDARIES LEFT FROM
WEDNESDAY STORMS TO BRING ADDITIONAL STORM FOCUS FOR THURSDAY AS
THE UPPER LOW BEGINS TO LIFT INTO THE SOUTHERN ROCKIES. HIGHEST
POPS OF THE WEEK ARE THUS SAVED FOR THURSDAY NIGHT INTO FRIDAY.
THE EJECTION OF THE LOW INTO A SHALLOW TROUGH LEAVES SOME COVERAGE
UNCERTAINTIES THIS FAR SOUTH...SO DO NOT WANT TO OVER-ADVERTISE
THE SEVERE THREAT BEYOND A NOD IN THE HWO. POPS SHOULD LOWER
SATURDAY INTO SUNDAY AS FLAT RIDGING ALOFT RETURNS. MOISTURE IS
SUFFICIENT FOR STORMS...BUT EXPECT A STRONGER CAPPING INVERSION.
ANOTHER LOW LATITUDE UPPER DISTURBANCE IS FORECAST BY THE GFS TO
BRING RAIN AND STORMS BY MIDWEEK...BUT WILL KEEP WITH THE MORE
CONSERVATIVE ECMWF UNTIL THE PATTERN DIFFERENCES BETWEEN MODELS
DECREASE. TEMPERATURES THROUGH THE PERIOD SHOULD CONTINUE TO BE
SEASONAL. A WEAK FRONT EXPECTED SATURDAY WILL PROBABLY ADD TO
DAYTIME TEMPERATURES THROUGH REDUCED CLOUDINESS.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 80 66 82 69 86 / 10 10 30 30 20
AUSTIN BERGSTROM INTL AIRPORT 79 66 81 68 85 / 10 10 30 30 20
NEW BRAUNFELS MUNI AIRPORT 79 66 82 69 87 / 10 20 30 30 20
BURNET MUNI AIRPORT 77 66 81 68 85 / 10 20 30 30 20
DEL RIO INTL AIRPORT 81 67 86 70 88 / 10 20 20 10 20
GEORGETOWN MUNI AIRPORT 79 67 82 68 86 / 10 10 30 30 20
HONDO MUNI AIRPORT 80 67 82 69 87 / 10 20 30 20 20
SAN MARCOS MUNI AIRPORT 78 66 81 68 85 / 10 20 30 30 20
LA GRANGE - FAYETTE REGIONAL 79 66 82 70 85 / 10 10 30 30 20
SAN ANTONIO INTL AIRPORT 79 68 82 71 86 / 10 20 30 20 20
STINSON MUNI AIRPORT 81 68 82 71 87 / 10 20 30 20 20
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...01
SYNOPTIC/GRIDS...04
PUBLIC SERVICE/DATA COLLECTION...12
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
326 PM CDT TUE APR 21 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 326 PM CDT TUE APR 21 2015
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING OVER THE WESTERN U.S. INTO ALBERTA AND VERY DEEP
TROUGHING OVER THE FORECAST AREA INTO THE GREAT LAKES. WITHIN THIS
TROUGH WAS AN UPPER LOW OVER EASTERN LAKE SUPERIOR...A SHORTWAVE
DROPPING SOUTH TOWARDS I-90 IN THE FORECAST AREA...AND ANOTHER
SHORTWAVE OVER NORTHEAST MN. COOL TEMPERATURES ALOFT REFLECTED BY
500MB TEMPS OF -27 TO -33C PER 12Z RAOBS...DAYTIME HEATING...NEAR
SATURATED CONDITIONS BETWEEN 700-850MB AND THE AFOREMENTIONED
SHORTWAVES HELPING TO PRODUCE PLENTY OF SHOWERS ACROSS THE
REGION....ESPECIALLY ALONG AND NORTH OF I-94. TEMPERATURES HAVE
STRUGGLED TO RISE WITH CLOUDS...PRECIP AND 850MB TEMPS OF -3 TO
-7C. READINGS HAVE ONLY CLIMBED INTO THE MID 30S TO LOW 40S. THE
COLD TEMPERATURES HAVE SUPPORTED A MIX OF RAIN AND SNOW...WITH THE
SNOW CONFINED MORESO TO HIGHER ELEVATIONS AND TAYLOR/CLARK
COUNTIES. ON TOP OF THE COOL AIR...A TIGHT PRESSURE GRADIENT AND
925MB WINDS OF 25-35 KT HAS RESULTED IN WINDS GUSTING TO THE 925MB
SPEEDS...MAKING IT FEEL FALL-LIKE. THESE WINDS ARE JUST BELOW
ADVISORY CRITERIA.
THE OVERALL UPPER PATTERN CHANGES LITTLE IN THE NEXT 24 HOURS WITH
ONLY A SLIGHT DRIFT EASTWARD OF THE UPPER LOW AND TROUGHING. THIS
SLIGHT DRIFT LOOKS TO BE ENOUGH SUCH THAT MUCH OF THE SHORTWAVE AND
INSTABILITY INDUCED SHOWERS ON WEDNESDAY WILL FALL EAST OF THE
FORECAST AREA. HOWEVER...PORTIONS OF TAYLOR AND ADAMS COULD GET
CLIPPED IN THE AFTERNOON. GETTING BACK TO TONIGHT...GENERAL MODEL
CONSENSUS SUGGESTS THE LOSS OF DAYTIME HEATING WILL ALLOW SHOWER
ACTIVITY TO BECOME MORE ISOLATED THROUGH THE EVENING...EVENTUALLY
ENDING BY MIDNIGHT.
CLOUDS LOOK TO HOLD OVER MUCH OF THE FORECAST AREA TONIGHT...AIDED
BY A SURGE OF 850MB MOISTURE CURRENTLY IN NORTHWEST ONTARIO DROPPING
SOUTHWARD WITH THE SHORTWAVE IN NORTHEAST MN. SUBSIDENCE IN THE WAKE
OF THIS SHORTWAVE...COMBINED WITH 925-700MB WINDS BACKING A BIT MORE
WESTERLY ON WEDNESDAY...WILL HELP TO RESULT IN MORE SUNSHINE.
DESPITE THE CLOUDS TONIGHT...AND A PERSISTENT BREEZE...TEMPERATURES
WILL STILL FALL AS THAT SHORTWAVE IN NORTHEAST MN DRAGS COLDER AIR
INTO THE FORECAST AREA. BY 12Z WED...850MB TEMPS ARE PROGGED TO DROP
TO -8 TO -11C...OR ALMOST 2 STANDARD DEVIATIONS BELOW NORMAL.
GUIDANCE LOWS IN THE MID 20S TO LOW 30S SEEM REASONABLE. HAVING MORE
SUNSHINE ON WEDNESDAY WILL HELP PRODUCE A WARMER DAY THAN
TODAY...ALBEIT STILL WELL BELOW NORMAL GIVEN 850MB TEMPS ONLY
CLIMBING TO -2 TO -7C BY 00Z THU. MOST LOCATIONS SHOULD CLIMB INTO
THE 40S...WITH LOW 50S LIKELY IN RIVER VALLEYS AND THE SOUTHWEST
PORTION OF THE FORECAST AREA.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 326 PM CDT TUE APR 21 2015
THE UPPER FLOW PATTERN LOOKS TO BECOME MORE PROGRESSIVE THROUGH THE
END OF THE WEEK IN RESPONSE TO A DEEP UPPER TROUGH APPROACHING THE
PACIFIC NORTHWEST. THIS WILL HELP TO PUSH THE UPPER RIDGING AND
WARMER AIR OVER THE WESTERN U.S. TOWARDS THE FORECAST AREA. 850MB
TEMPS DO NOT CHANGE A WHOLE LOT WED NIGHT...BUT MORE IMPRESSIVE WARM
ADVECTION COMES IN FOR THU WITH 850MB TEMPS REACHING 0 TO -2C BY 00Z
FRI...AND 0 TO 4C BY 00Z SAT. LOW PRECIPITABLE WATER ON
THURSDAY...AROUND 0.1 INCHES...SHOULD HELP TO TANK DEWPOINTS AND
RESULTING RHS. COMBINED WITH A DRYING DAY ON WEDNESDAY AND A 10-15
MPH NORTHWEST BREEZE...FIRE WEATHER COULD BE A CONCERN. SEE FIRE
WEATHER SECTION BELOW.
FOR FRIDAY INTO SATURDAY...AN UPPER LOW CURRENTLY NEAR LOS ANGELES
IS PROGGED TO LIFT THROUGH THE CENTRAL PLAINS AND TRACK EASTWARD
ACROSS ILLINOIS. ALTHOUGH THIS TRACK IS SOUTH OF THE FORECAST
AREA...MOISTURE ADVECTION SPREADS NORTHWARD AHEAD OF THE UPPER LOW
TO HELP PRODUCE SOME RAIN. THE SPEED HAS SLOWED DOWN A BIT...AND AS
A RESULT DELAYED THE SPREADING OF CHANCES OF RAINFALL EASTWARD ON
FRIDAY. FURTHER DELAYS MAY BE NEEDED. RAIN CHANCES SPREAD ACROSS THE
FORECAST AREA FRIDAY NIGHT AND THEN SHIFT TO SOUTH OF I-90 ON
SATURDAY...RESULTING FROM EASTERLY FLOW DRAGGING MORE DRY AIR INTO
NORTHERN SECTIONS. OVERALL APPEARS TO BE A LIGHT RAIN...WITH THE
HEAVIER RAIN TO THE SOUTH TIED TO THE UPPER LOW FORCING.
DRIER WEATHER LOOKS TO FOLLOW SATURDAY NIGHT AND SUNDAY AS UPPER
RIDGING BUILDS BACK INTO THE FORECAST AREA FROM THE WEST.
TEMPERATURES SHOULD REBOUND CLOSER TO NORMAL AS WELL WITH MORE SUN
ON SUNDAY AND 850MB TEMPS IN THE 0-4C RANGE.
FOR EARLY NEXT WEEK UNCERTAINTY BEGINS TO INCREASE. NOT SO MUCH ON
THE UPPER PATTERN WHERE MODELS ADVERTISE TROUGHING DEVELOPING FROM
THE NORTHEAST U.S. INTO THE SOUTHEAST U.S....BUT WITH PRECIPITATION
CHANCES AS THIS TROUGH DEVELOPS. THE 21.12Z GFS HAS A SHORTWAVE
TROUGH DROPPING THROUGH THE REGION TO BRING PRECIPITATION TO THE
AREA. MEANWHILE THE 21.12Z ECMWF AND CANADIAN SUGGEST A DRY
PERIOD AS HIGH PRESSURE DOMINATES AT THE SURFACE...WITH THE
AFOREMENTIONED SHORTWAVE TROUGH FALLING APART. FOR NOW HAVE WENT
WITH THE CONSENSUS AND HAVE 20-30 PERCENT CHANCES. HOW THIS
SHORTWAVE TROUGH EVOLVES ALSO HAS AN IMPACT ON TEMPERATURES. IN
THE CASE OF THE 21.12Z GFS...IT SUGGESTS 850MB TEMPS PLUNGE TO
AROUND -4C BY 12Z TUE...ABOUT 8C COLDER THAN THE ECMWF. ALSO
FOLLOWED CONSENSUS HERE FOR NOW WITH TEMPS JUST SHY OF NORMAL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1201 PM CDT TUE APR 21 2015
EXPECT WINDY CONDITIONS OUT OF THE NORTHWEST TO CONTINUE THROUGH
THE TAF PERIOD WITH GUSTS OF 25 TO 35 KT THIS AFTERNOON. VFR
SHOULD PERSIST WITH A BRIEF MVFR CEILING POSSIBLE WITH A HEAVIER
SHOWER THIS AFTERNOON. SOME GUIDANCE HINTS AT MVFR CEILINGS EARLY
WEDNESDAY MORNING AS BACK EDGE OF CLOUDS MOVE THROUGH.
HOWEVER...WITH MIX OF VFR AND MVFR UPSTREAM ACROSS MINNESOTA KEPT
CEILINGS AT VFR WITH SCATTERING OUT BY MID WEDNESDAY MORNING.
&&
.FIRE WEATHER...
ISSUED AT 326 PM CDT TUE APR 21 2015
AFTER SOME RECENT COOL/WET DAYS...CONDITIONS LOOK TO DRY OUT AGAIN
WEDNESDAY AND THURSDAY. RELATIVE HUMIDITIES ARE EXPECTED TO DROP
INTO THE 20S ON WEDNESDAY AND MAY EVEN DROP BELOW 20 PERCENT IN A
FEW SOUTHEAST MN LOCATIONS ON THURSDAY. FIGURE MUCH OF WEDNESDAY
WILL BE A DRYING DAY FOR FUELS GIVEN THE WET WEATHER...WITH A 15
TO 25 MPH NORTHWEST BREEZE AIDING IN THE DRYING. THEREFORE
THURSDAY WOULD APPEAR TO BE THE MORE CONCERNING DAY...THOUGH WINDS
LOOK LIGHTER IN THE 10 TO 15 MPH RANGE. NEVERTHELESS...WELL HAVE
TO KEEP A CLOSE EYE ON THURSDAY AND SEE TOO WHERE ALL THE
VEGETATION STANDS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...WIND ADVISORY UNTIL 6 PM CDT THIS EVENING FOR MNZ086-087-094-095.
IA...WIND ADVISORY UNTIL 6 PM CDT THIS EVENING FOR IAZ008>010-018-019-
029-030.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...CC
FIRE WEATHER...AJ