Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/15/13
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
715 PM EDT TUE MAY 14 2013
.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFF THE SOUTHEAST COAST TONIGHT AND OUT TO
SEA INTO THURSDAY. A WARM FRONT IS FORECAST TO LIFT THROUGH OUR AREA
ON EARLY WEDNESDAY, FOLLOWED BY A COLD FRONT WEDNESDAY NIGHT. THIS
FRONT WILL SAG TO OUR SOUTH AND STALL FOR THE LATE WEEK PERIOD AND
INTO THE WEEKEND. THE FRONT MAY LIFT BACK NORTHWARD ACROSS THE AREA
AS A WARM FRONT EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
USED THE LATEST RAP AND HR3 TO MAKE SOME SOUTHWARD ADJUSTMENTS TO
MENTION OF PCPN AT ONSET EARLY OVERNIGHT. SO FAR AIRPORTS IN WRN
PA ARE OBSERVING TRACES. OTHERWISE TEMPS WERE TWEAKED SLIGHTLY
DOWNWARD BASED ON CURRENT TEMPS. MOST OTHER PARAMETERS AND GRIDS
DID NOT NEED MUCH CHANGE.
RAPIDLY THICKENING AND LOWERING CIGS ...THE BAND YOU SEE ON 19Z
SATELLITE IMAGERY FROM MICHIGAN TO W PTNS PA AND NYS. SCT LIGHT
SHOWERS EXPECTED...MOSTLY TRACE...AFTER MIDNIGHT AND MODELED IMO
PRETTY WELL BY THE 00Z/14 NSSL WRF AND NOW THE 18Z RAP...FLYING
SEWD 30-40 KT. LIGHT S WIND IN THE WAA PATTERN BEHIND THE
DEPARTING SFC HIGH OFF THE SE USA COAST.
50 50 BLENDED 12Z/14 NCEP MOS GUIDANCE FOR TEMPS/WINDS/DEWS.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/...
WEDNESDAY...THE 12Z GFS LOOKS LIKE MY IDEA OF A BEST MODEL SOLN OF
THE 12Z INTERNATIONAL SUITE. THE 12/14 GFS IMO HAS THE RIGHT IDEA
ABOUT STRONG CONVECTION AND PROBABLY STREAMING EAST SOUTHEAST FROM
SOUTHERN PA ACROSS S NJ AND OR THE DELMARVA LATE IN THE DAY WEDNESDAY.
SPC 1715Z SWODY2 ASSESSMENT MATCHES MY THINKING.
THE INCREASING BOUNDARY LAYER MOISTURE MAY BE OVERDONE BY THE MODELS,
THUS LIMITING INSTABILITY AND THE POTENTIAL FOR INITIATING CONVECTION.
THE 18Z GFS LAMP HAS GRIDDED LAMP TSTM PROBS IN W NYS AND NW PA BY
14Z.
MODEL REMNANTS OF AN EML NOW SPREADING EWD FROM THE MIDWEST THAT
SUPPORTS CONCERN FOR HAILERS....INCREASING THE 700-500MB LAPSE
RATES LATE IN THE DAY.
MORE THAN ADEQUATE BULK SHEAR FOR SVR WIND... AND SO THE QUESTION
BECOMES...IS THERE ENOUGH MOISTURE TO SUPPORT TSTM GENERATION. 12Z/14
GFS ML CAPE IS ONLY 600J LATER IN THE DAY AND SO DID NOT WORD HAIL
OR GUSTY WINDS IN THE ZONE PRODUCTS.
OTRW TEMPS/WINDS/DEWS ARE 50 50 BLENDED 12Z/14 NCEP MOS GUIDANCE
WITH A LEAN TO A WARMER TEMP SOLN SINCE MOST OF THE DAY SHOULD
BE RAINFREE.
CONFIDENCE ON POPS IS BELOW AVG AND I MAY BE OVER FCST THE CHC OF
A SHOWER OR TSTM WED AFTN.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
THE PRE-FRONTAL SURFACE TROUGH AND ANY ASSOCIATED CONVECTION SHOULD
BE PROGRESSING THROUGH THE AREA DURING THE EARLY EVENING TIME
WEDNESDAY. ONCE THE TROUGH MOVES THROUGH AND THE SUN GOES DOWN,
ANY CONVECTION SHOULD DIMINISH. THE ACTUAL COLD FRONT IS NOT
EXPECTED TO MOVE THROUGH THE AREA UNTIL WEDNESDAY NIGHT. THERE
STILL COULD BE A FEW SHOWERS AROUND UNTIL THE FRONT ACTUALLY MOVES
THROUGH, BUT ANY THUNDERSTORM ACTIVITY SHOULD HAVE ENDED BY THE
TIME THE FRONT APPROACHES.
THE AFOREMENTIONED COLD FRONT WILL SAG TO OUR SOUTH THURSDAY INTO
FRIDAY, WHILE THE PARENT LOW WILL SPIN THROUGH NEW ENGLAND AND
INTO THE CANADIAN MARITIMES. THIS WILL KEEP A STEADY WEST TO
NORTHWEST FLOW ACROSS THE AREA. EVEN THOUGH A WEAK SURFACE TROUGH
IS FORECAST TO CROSS THE AREA ON THURSDAY, MOST OF THE AREA SHOULD
REMAIN DRY THURSDAY AND FRIDAY. THE EXCEPTION TO THIS WILL BE
ACROSS THE SOUTHERN THIRD OF THE AREA, WHICH WOULD BE CLOSE TO THE
OLD COLD FRONT AS IT SLOWLY SAGS TO OUR SOUTH, BEFORE STALLING.
THERE MAY BE ENOUGH MOISTURE AND LIFT TO CREATE A FEW SCATTERED
SHOWERS/THUNDERSTORMS ACROSS SOUTHERN NEW JERSEY AND THE DELMARVA.
AS WE MOVE INTO THE WEEKEND, THE LOW TO OUR NORTHEAST WILL SLIDE OUT
TO SEA, ALLOWING FOR HIGH PRESSURE TO BUILD ACROSS THE NORTHEAST.
THIS HIGH IS EXPECTED TO PUSH OFF THE NEW ENGLAND COAST AND TO
OUR EAST THROUGH THE WEEKEND. THIS WILL PUT OUR AREA INTO AN
EASTERLY/SOUTHEASTERLY FLOW FOR MUCH OF THE WEEKEND, WHICH COULD
HELP KEEP OUR TEMPERATURES FRONT RISING VERY MUCH. IT MAY ALSO
KEEP SOME CLOUD COVER ACROSS THE AREA, AND WITH AN INCREASE IN
MOISTURE, ANY ADDITIONAL LIFT COULD LEAD TO SOME PRECIPITATION.
FOR NOW WE ONLY KEEP CHANCE/SLIGHT CHANCE POPS THROUGH THE
WEEKEND.
THE FRONT THAT STALLS TO OUR SOUTH IS EXPECTED TO BEGIN LIFTING
BACK NORTHWARD AS A WARM FRONT BY LATE SUNDAY INTO MONDAY. THIS
COULD LEAD TO SOME SHOWER ACTIVITY SUNDAY NIGHT INTO MONDAY. THEN
WE WAIT AND SEE WHAT HAPPENS WITH THE NEXT SYSTEM AS IT MOVES OUT
OF THE CENTRAL/NORTHERN PLAINS AND THROUGH THE GREAT LAKES.
GFS/ECMWF DIFFER ON HOW FAST THEY MOVE THE SYSTEM. IT`S POSSIBLE
IT COULD GET HERE AS EARLY AS WEDNESDAY, BUT WE WILL SEE HOW
MODELS HANDLE IT OVER THE NEXT FEW DAYS.
&&
.AVIATION /23Z TUESDAY THROUGH SUNDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
WITH THE 00Z TAFS, THE TERMINALS WERE KEPT VFR ALTHOUGH CONFIDENCE
IS NOT HIGH LATE WEDNESDAY AFTERNOON.
FOR TONIGHT, WE BRING IN A MID DECK VFR CIG AND SLOWLY BACK THE
WINDS FROM WESTSOUTHWEST TO SOUTHEAST OVERNIGHT WITH SPEEDS
GENERALLY LESS THAN 10 KNOTS. THE FORECAST WIND GROUPS REPRESENT
AN AVERAGE DIRECTION FOR THE HOURS THE FCST PERIOD IS VALID. WE
DO CARRY THE MENTION OF NON RESTRICTING SHOWERS (EXCEPT AT KABE
AND KRDG) FOR A COUPLE OF HOURS LATER TONIGHT. SO FAR WE HAVE NOT
SEEN ANY VSBY RESTRICTIONS UPSTREAM.
THEN ON WEDNESDAY WE ARE FORECASTING ANOTHER MID DECK VFR CIG TO
PREVAIL. THE FORECAST CONVECTIVE TEMPERATURE IS VERY HIGH AND DO
NOT THINK WE WILL BE ABLE TO GENERATE A LOWER CIG. SOUTH WINDS ARE
FORECAST TO PREVAIL WITH SUSTAINED SPEEDS OF 10 TO 15 KTS AND
GUSTS NEAR OR AROUND 20 KT FORECAST AT MOST OF THE TERMINALS.
WE ARE NOT CONFIDENT ABOUT THUNDER OCCURRING BECAUSE THE FORECAST
MODELS ARE PRESENTLY WAY OVERFORECASTING THE DEW POINTS WHICH IN
TURN INFLATES THE THUNDERSTORM POTENTIAL. WE CONTINUED WITH WHAT
OUR PRECEDING SHORT TERM MET DID WITH KPHL AND CARRY A CHANCE OF
SHRAS LATE IN THE TAF PERIOD ALL TERMINALS. THE HIGHER INTO THE
60S THE DEW POINTS GET TOMORROW, THE GREATER THE CHANCE FOR
THUNDER TO OCCUR.
OUTLOOK...
WEDNESDAY NIGHT...MOSTLY VFR CONDITIONS. MVFR POSSIBLE WITH ANY
SHOWERS/THUNDERSTORMS EARLY.
THURSDAY-FRIDAY...MOSTLY VFR CONDITIONS.
SATURDAY-SUNDAY...MAINLY VFR CONDITIONS...POSSIBLE PERIODS OF MVFR
SATURDAY NIGHT. SHOWERS ALSO POSSIBLE
&&
.MARINE...
HIGH PRESSURE WILL MOVE OVER THE SERN CONUS TODAY AND THEN FURTHER
EWD OVER THE SERN COASTAL WATERS TONIGHT. AS A RESULT THE WIND
AND SEAS ARE EXPECTED TO REMAIN BELOW SCA CRITERIA THRU THE NEAR
PERIOD.
WEDNESDAY...GUIDANCE INDICATES OUR COASTAL WATERS WILL REACH SCA
WIND GUSTS DURING THE DAYTIME WEDNESDAY WITH SEAS BUILDING TO 5
FT ON THE ATLC WATERS DURING THE AFTN GENERATED BY THE SLY FLOW
AHEAD OF AN APPROACHING WFRONT. FOR LOWER DE BAY THERE MAY BE A
PERIOD OF SCA WIND GUSTS WEDNESDAY BUT CONFIDENCE WAS NOT HIGH
ENOUGH AT THIS TIME TO INCLUDE THIS AS A HEADLINE.
AM STARTING THE SCA A BIT SOONER ON THE ATLC WATERS WEDNESDAY...
AROUND 12Z. WILL LEAVE IT TO THE MID SHIFT TO ISSUE FOR DE BAY.
OUTLOOK...
THE SMALL CRAFT ADVISORY WILL REMAIN IN EFFECT THROUGH WEDNESDAY
NIGHT AS SEAS WILL LIKELY REMAIN ABOVE 5 FEET AND WINDS COULD GUST
AROUND 25 KNOTS EARLY. HOWEVER, AFTER THE COLD FRONT MOVES
THROUGH, WINDS ARE EXPECTED TO DROP BELOW ADVISORY LEVELS THROUGH
FRIDAY NIGHT. SEAS MAY REMAIN AROUND 5 FEET INTO EARLY THURSDAY,
BUT NOT CONFIDENT ENOUGH TO EXTEND THE ADVISORY OUT ANOTHER DAY
YET. ONCE SEAS DROP BELOW 5 FEET, THEY WILL REMAIN SO THROUGH
FRIDAY NIGHT.
AS WE MOVE INTO THE WEEKEND, HIGH PRESSURE BUILDS TO OUR
NORTH/NORTHEAST, WHICH WILL PRESENT AN EAST/SOUTHEAST FETCH ACROSS
THE WATERS. WINDS COULD BEGIN APPROACHING SMALL CRAFT CONDITIONS
STARTING SATURDAY NIGHT AND SEAS COULD BEGIN INCREASING AS WELL
CLOSE TO 5 FEET BY SUNDAY.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 7 AM WEDNESDAY TO 8 AM EDT THURSDAY
FOR ANZ450>455.
&&
$$
SYNOPSIS...ROBERTSON
NEAR TERM...DRAG/GIGI
SHORT TERM...DRAG
LONG TERM...ROBERTSON
AVIATION...GIGI/ROBERTSON
MARINE...DRAG/ROBERTSON
AREA FORECAST DISCUSSION
NWS MIAMI FL
950 AM EDT MON MAY 13 2013
.UPDATE...
NO CHANGES ARE PLANNED FOR THE MORNING UPDATES. THE 12Z MFL
SOUNDING SHOWS THE MID LAYER CAPS ARE MOSTLY GONE BUT THE LAPSE
RATES REMAIN WEAK WITH ONLY MARGINAL INSTABILITY WITH WNW STEERING
FLOW OF AROUND 8-10 KNOTS. THE HRRR DOES NOT GET TOO OVERLY EXCITED AND
AGAIN SHOWS LATE DAY CONVECTION OVER THE INTERIOR AND MOVING
TOWARDS THE EAST COAST METRO REGION AFTER 19Z. THIS SEEMS
REASONABLE GIVEN THE ABOVE DISCUSSION. THE COLD FRONT IS CURRENTLY
JUST NORTH OF LAKE OKEECHOBEE AND QUITE EVIDENT ON VISIBLE
SATELLITE AND HEREIN LIES THE FLY IN THE OINTMENT. THERE IS QUITE
DENSE CLOUD FIELD BEHIND THE FRONT SO IT WILL DEPEND ON HOW QUICK
THIS CLOUD SHIELD MOVES SOUTH AND IF IT HOLDS TOGETHER. IT COULD
CUT OFF SOME OF THE DIURNAL HEATING. BUT FOR NOW WILL LEAVE
FORECAST AS IS BECAUSE THE ATMOSPHERE IS CAPABLE OF PRODUCING SOME
LATE DAY STRONG ACTIVITY IN THE WARM AND HUMID SECTOR SOUTH OF THE
FRONT.
KOB
&&
.PREV DISCUSSION... /ISSUED 720 AM EDT MON MAY 13 2013/
AVIATION...
LIGHT WINDS EARLY THIS MORNING WILL BECOME SOUTHERLY AT 5-10 KNOTS
BY MID-MORNING...THEN INCREASE FURTHER AND VEER SOUTHWESTERLY BY
AFTERNOON IN ADVANCE OF A COLD FRONT. SCATTERED SHOWERS AND
THUNDERSTORMS MAY DEVELOP AHEAD OF THE FRONT...THUS LOCALLY STRONG
WINDS AND BRIEF FLIGHT RESTRICTIONS ARE POSSIBLE. OVERALL...VFR
CONDITIONS WILL PREVAIL TODAY THROUGH MUCH OF THE WEEK. DRIER AIR
FILTERS IN TONIGHT...ENDING SHOWER CHANCES AND CLOUD-COVER. WINDS
OVERNIGHT WILL BE LIGHT AND NORTHWESTERLY.
PREV DISCUSSION... /ISSUED 300 AM EDT MON MAY 13 2013/
.ONE MORE WET DAY BEFORE DRY WEATHER RETURNS TO SOUTH FLORIDA
FOR REST OF THE WEEK...
SHORT TERM...
A COLD FRONT OVER CENTRAL FLORIDA WILL MOVE SOUTH AND THROUGH
SOUTH FLORIDA THIS AFTERNOON INTO EARLY THIS EVENING. THE WINDS
WILL SWING FROM A SOUTHWEST DIRECTION THIS MORNING TO A WESTERLY
DIRECTION THIS AFTERNOON FOCUSING THE SCATTERED SHOWERS AND
THUNDERSTORMS MAINLY OVER THE EASTERN INTERIOR AND EAST COAST
METRO AREAS. SO WILL CONTINUE THE 20 TO 30 PERCENT POPS OVER THE
INTERIOR AREAS AND THE 30 TO 40 PERCENT POPS OVER THE EAST COAST
METRO AREAS FOR THIS AFTERNOON.
A FEW OF THE STORMS COULD EVEN BECOME STRONG LATE THIS AFTERNOON
MAINLY OVER THE EAST COAST METRO AREAS...WHERE THE SEA BREEZES
COLLIDE. THE PRIMARY IMPACTS FROM THE STORMS WILL BE LIGHTNING
STRIKES...GUSTY WINDS...AND LOCALLY HEAVY RAINFALL.
THE COLD FRONT WILL CONTINUE TO MOVE SOUTH INTO THE FLORIDA KEYS
TONIGHT BEFORE STALLING OVER THE CUBA AREA ON TUESDAY. AT THE SAME
TIME...HIGH PRESSURE WILL BUILD INTO THE SOUTHEAST UNITED STATES
FROM THE NORTHWEST. THIS WILL ALLOW FOR A PRESSURE GRADIENT TO
BUILD OVER SOUTH FLORIDA LATE TONIGHT INTO TUESDAY LEADING TO
BREEZY NORTHERLY WINDS OVER SOUTH FLORIDA. THE WEATHER WILL ALSO
BECOME DRY LATE TONIGHT INTO TUESDAY OVER SOUTH FLORIDA...AS DRY
AIR WORKS INTO THE AREA FROM THE NORTH.
THE HIGH WILL THEN SLOWLY MOVE EAST INTO THE WESTERN ATLANTIC
WATERS WEDNESDAY INTO END OF THIS WEEK. THIS WILL ALLOW FOR THE
WINDS TO SWING SLOWLY TO A EASTERLY DIRECTION WHILE SLOWLY
DECREASING TO LESS THEN 10 KNOTS BY END OF THE WEEK. THE DRY
WEATHER WILL REMAIN IN PLACE OVER SOUTH FLORIDA THROUGH END OF
THE WEEK.
LONG TERM...
THE HIGH WILL CONTINUE TO MOVE FURTHER EAST INTO THE ATLANTIC
WATERS THIS WEEKEND INTO EARLY NEXT WEEK. THIS WILL ALLOW FOR THE
WINDS TO BECOME MORE SOUTHEAST BY LATE THIS WEEKEND INTO EARLY NEXT
WEEK...AND ALLOW FOR SOME LOW LEVEL MOISTURE TO RETURN TO THE
AREA. SO HAVE ADDED A SLIGHT CHANCE OF SHOWERS TO THE WESTERN
AREAS OF SOUTH FLORIDA EARLY THIS WEEKEND...BEFORE INCLUDING ALL OF
SOUTH FLORIDA FOR LATE THIS WEEKEND INTO EARLY NEXT WEEK.
MARINE...
THE WESTERLY WINDS TODAY WILL SWING TO A NORTHERLY DIRECTION
TONIGHT INTO TUESDAY...AS SPEEDS INCREASE FROM AROUND 10 KNOTS
TODAY TO 15 TO 20 KNOTS TONIGHT INTO TUESDAY. THE WINDS WILL THEN
SLOWLY SWING TO A EASTERLY DIRECTION WEDNESDAY INTO THURSDAY...AS
SPEEDS SLOWLY DECREASE TO 10 TO 15 KNOTS. THIS WILL ALLOW FOR THE
SEAS IN THE ATLANTIC WATERS TO REMAIN BELOW 6 FEET THROUGH
THURSDAY...EXCEPT 6 FEET IN THE GULF STREAM WATERS TUESDAY
MORNING. ON THE GULF SIDE...THE SEAS WILL BE LESS THAN 6 FEET THIS
THROUGH THURSDAY.
FIRE WEATHER...
THE RELATIVE HUMIDITIES TODAY WILL REMAIN ABOVE THE 35 PERCENT
CRITICAL VALUE OVER SOUTH FLORIDA...DUE TO THE MOISTURE IN PLACE
AHEAD OF THE COLD FRONT. ON TUESDAY...THE RELATIVE HUMIDITIES
SHOULD REMAIN ABOVE THE 35 PERCENT CRITICAL VALUE EXCEPT FOR THE
THE AREA WEST OF LAKE OKEECHOBEE WHERE THEY COULD FALL DOWN TO
AROUND 35 PERCENT FOR COUPLE OF HOURS. THE ERC (ENERGY RELEASE
COMPONENT) ACROSS SOUTH FLORIDA FOR TODAY INTO TUESDAY WILL BE IN
THE 20S. SO NO RED FLAG WATCHES OR WARNING WILL BE NEEDED FOR
SOUTH FLORIDA TODAY INTO TUESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 87 66 80 67 / 30 10 - -
FORT LAUDERDALE 88 69 81 71 / 40 20 - -
MIAMI 89 70 82 70 / 40 20 - 0
NAPLES 84 66 87 64 / 10 - - 0
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1227 PM CDT MON MAY 13 2013
.UPDATE...
ISSUED AT 1201 PM CDT MON MAY 13 2013
WARM AIR ADVECTION LIGHT SHOWERS CONTINUE TO DEVELOP ACROSS
NORTHERN IOWA AND SOUTHERN MN HEADING SOUTHEAST WITH H700 FLOW.
HAVE UPDATED ZONES TO INCLUDE A FEW SPRINKLES OVER THE NORTHERN
SECTIONS FOR THE NEXT HOUR OR TWO.
&&
.SHORT TERM.../TODAY/
ISSUED AT 416 AM CDT MON MAY 13 2013
TEMPS AND SUBTLE PRECIP TRENDS WILL BE THE MAIN CONCERN THIS
MORNING. KINEMATIC FORCING ASSOCIATED WITH CANADIAN SHORT WAVE
STILL WELL REMOVED FROM U.S. BORDER WILL REMAIN TO OUR NORTH AND
EAST TODAY. HOWEVER STRONG THERMODYNAMIC FORCING AHEAD OF THIS
FEATURE AND ADVANCING UPPER LEVEL RIDGE IS CURRENTLY PRODUCING
SCATTERED HIGH BASED SHOWERS ACROSS THE DAKOTAS. MODELS SUGGEST
THIS STRONG THETA-E ADVECTION WILL BRUSH NERN IA AROUND MIDDAY.
THERE IS A DECENT AMOUNT OF DRY AIR BELOW 3KM ON THE MASON CITY
SOUNDING...HOWEVER IT IS SATURATED ABOVE AND UVM ASSOCIATED WITH
STRONG WARM ADVECTION OFTEN IS SUFFICIENT TO GET AT LEAST
SOMETHING TO THE SURFACE. FEEL MODEL QPF AND AREAL COVERAGE OF
MEASURABLE POTENTIAL IS OVERDONE...BUT CONFIDENCE IS THERE TO
INTRODUCE A SHORT PERIOD OF SPRINKLES NE CENTERED AROUND 18Z.
FORECAST SOUNDINGS ADJUSTED FOR RECENT MIXING SUGGEST SOMETHING
CLOSE TO A MOS BLEND FOR HIGHS TODAY...WHICH PERFORMED WELL
YESTERDAY.
.LONG TERM.../TONIGHT THROUGH SUNDAY/
ISSUED AT 416 AM CDT MON MAY 13 2013
MAIN FORECAST CONCERN IS WITH HOT TEMPERATURES AND FIRE WEATHER
ON TUESDAY...AND THUNDERSTORM CHANCES LATE IN THE WEEK. LEANED
TOWARD SREF TONIGHT INTO WEDNESDAY AS GFS/NAM/ECMWF ARE TOO COLD
FOR TEMPS TOMORROW.
TONIGHT THROUGH WEDNESDAY...WAA CONTINUES TONIGHT INTO TOMORROW
AHEAD A COLD FRONT AND AREA OF LOW PRESSURE SET TO MOVE ACROSS THE
FORECAST AREA TUESDAY NIGHT. GOOD MIXING TO 900MB TOMORROW AND
POSSIBLY EVEN HIGHER. THIS MAY TAP INTO THE VERY WARM 850MB TEMPS
RANGING FROM 22C TO 25C ACROSS IOWA. WINDS LOOK TO GUST TO AROUND
25-30 KNOTS ACROSS THE NORTH AND SLIGHTLY LESS FURTHER SOUTH. VERY
DRY AIR MASS MOVING INTO THE STATE FROM THE PLAINS AND MODELS NOT
CAPTURING THE CURRENT DEW POINTS TRENDS OVER THIS AREA. FELT
CURRENT FORECAST AND MODELS WERE TOO HIGH FOR SURFACE DEW POINTS
TONIGHT INTO TOMORROW. PLUS WITH THE GOOD MIXING...LEANED TOWARD
LOWERING DEW POINTS 4 TO 6 DEGREES TONIGHT INTO TOMORROW WHICH WAS
FAIRLY CLOSE TO THE 900MB FROM THE NAM12. WITH THE DRIER AIR NOW
FORECAST...LEANED TOWARD INCREASING MAX TEMPS FOR TUESDAY ROUGHLY
1-3 DEGREES ACROSS THE FORECAST AREA. IN SOME PLACES FORECASTING A
RECORD HIGH FOR TOMORROW.
COLD FRONT SHOULD ENTER THE NORTHWEST PORTIONS OF THE FORECAST AREA
BY AROUND 00Z WEDNESDAY AND CONTINUE TO TRACK SOUTH OVERNIGHT INTO
WEDNESDAY MORNING. LIMITED MOISTURE WITH FRONT BUT ENOUGH
INSTABILITY AND FORCING TO KEEP MENTION OF SLIGHT CHANCES GOING
TUESDAY INTO WEDNESDAY. FRONT WASHES OUT ACROSS NORTHERN MISSOURI
DURING THE DAY WEDNESDAY AND MAY SEE A STRAY THUNDERSTORM ALONG
THE BORDER.
THURSDAY THROUGH MONDAY...SURFACE HIGH PRESSURE MOVES BACK IN
OVER THE STATE FOR THURSDAY AND LOOKS TO BE STRONG ENOUGH TO KEEP
CONDITIONS DRY FOR AT LEAST NORTHERN IOWA. ECMWF TRIES TO BRING
MOISTURE NORTHWARD DURING THE DAY AND MAY SEE THUNDERSTORM
ACTIVITY ACROSS THE SOUTH. EXTENDED MODELS IN DECENT AGREEMENT
WITH A SLOW MOVING SURFACE LOW AND UPPER LEVEL TROUGH TO AFFECT
THE PLAINS AND INTO THE CORN BELT FRIDAY INTO THE WEEKEND. BEST
THUNDERSTORM CHANCES IS SATURDAY NIGHT INTO SUNDAY WITH LLJ
DEVELOPING AHEAD OF THE TROUGH.
&&
.AVIATION...13/18Z
ISSUED AT 1226 PM CDT MON MAY 13 2013
MAIN CONCERNS THIS PERIOD AND JUST BEYOND WILL BE WINDS. SOME MID
TO HIGH LEVEL BKN CLOUDS ACROSS THE FORECAST AREA WILL MOVE ESE
THIS AFTERNOON. OTHER THAN A FEW SPRINKLES...NO ORGANIZED
CONVECTION EXPECTED WITH THIS PUSH OF WARM AIR. HOWEVER...WINDS
HAVE BEEN GUSTING NORTHWEST SITES AS MIXED LAYER INCREASES IN
DEPTH. EXPECT MOST SITES TO SEE GUSTS TO 20 TO 25 KTS THROUGH 01Z
WHEN DECOUPLING OCCURS. PUSH OF WARMER AIR TO ARRIVE TUESDAY AND
DEPTH OF MIXED LAYER INCREASES AGAIN AFT 18Z. MAY SEE SUSTAINED SFC
WINDS 20 TO 25 KTS WITH GUSTS 35 TO 40KTS...MAINLY NORTH SITES...AFT 19Z
TUESDAY AS MIXING MAXIMIZED DURING THE AFTERNOON HOURS.
&&
.FIRE WEATHER...
ISSUED AT 416 AM CDT MON MAY 13 2013
FIRE WEATHER CONCERNS ARE INCREASING SOMEWHAT TODAY WITH STRONGER
WIND AND LOW RH DUE TO MIXING. LOCAL AND UPSTREAM SOUNDINGS
INITIALIZED TOO MOIST IN THE LOWEST 1.5KM AT 00Z IN MOST MODELS SO
HAVE DEWPOINTS BELOW MOS AND CONSENSUS. RAP WAS THE DRIEST AND
CLOSEST TO REALITY. DID NOT GO THAT LOW YET BUT LEANED IN THAT
DIRECTION. THIS RESULTED IN MIN RH AROUND 25 PERCENT IN 5-6
COUNTIES W CENTRAL AND NW...BUT SUSTAINED WINDS WILL STAY JUST BELOW
RED FLAG WARNING CRITERIA /25 MPH/. THUS NO HEADLINES TODAY...BUT
WILL MENTION IN HWO AND HIGHLIGHT IN FIRE WEATHER FORECAST. DRYNESS
OF FUELS ALSO SOMEWHAT IN QUESTION OVER NRN IA. USED AS A PROXY FOR
FARTHER WEST WHERE CLIMATE DATA IS MORE QUESTIONABLE...MASON CITY
HAS HAD WETTEST METEOROLOGICAL SPRING TO DATE.
TUESDAY LOOKS TO BE HOTTER AND MUCH DRIER THAN PREVIOUSLY
ANTICIPATED AS MODELS OVERDOING THE SURFACE DEW POINTS ACROSS
CENTRAL IOWA. MIXING UP TO 3000 TO 3500 FEET BY TUESDAY AFTERNOON
WILL RESULT IN DEW POINTS IN THE UPPER 40S TO THE LOWER 50S.
HENCE...RH VALUES ARE FORECAST TO DROP TO 25 PERCENT OR LESS
GENERALLY ALONG AND WEST OF INTERSTATE 35. TEMPS WILL RAPIDLY
INCREASE IN THE MORNING AND THE 25 PERCENT RH VALUES LOOK TO BE
REALIZED BY AROUND NOON. SOUTHWEST WINDS GUSTING TO 30 TO 35 MPH
BY THE AFTERNOON. SO WITH THE LOW RH...GUSTY WINDS...AND HOT
TEMPS...BORDERLINE POTENTIAL FOR A RED FLAG WARNING ACROSS WESTERN
PORTIONS OF THE FORECAST AREA.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...REV
SHORT TERM...SMALL
LONG TERM...PODRAZIK
AVIATION...REV
FIRE WEATHER...SMALL/PODRAZIK
AREA FORECAST DISCUSSION...UPDATED
NWS DES MOINES IA
1203 PM CDT MON MAY 13 2013
.UPDATE...
ISSUED AT 1201 PM CDT MON MAY 13 2013
WARM AIR ADVECTION LIGHT SHOWERS CONTINUE TO DEVELOP ACROSS
NORTHERN IOWA AND SOUTHERN MN HEADING SOUTHEAST WITH H700 FLOW.
HAVE UPDATED ZONES TO INCLUDE A FEW SPRINKLES OVER THE NORTHERN
SECTIONS FOR THE NEXT HOUR OR TWO.
&&
.SHORT TERM.../TODAY/
ISSUED AT 416 AM CDT MON MAY 13 2013
TEMPS AND SUBTLE PRECIP TRENDS WILL BE THE MAIN CONCERN THIS
MORNING. KINEMATIC FORCING ASSOCIATED WITH CANADIAN SHORT WAVE
STILL WELL REMOVED FROM U.S. BORDER WILL REMAIN TO OUR NORTH AND
EAST TODAY. HOWEVER STRONG THERMODYNAMIC FORCING AHEAD OF THIS
FEATURE AND ADVANCING UPPER LEVEL RIDGE IS CURRENTLY PRODUCING
SCATTERED HIGH BASED SHOWERS ACROSS THE DAKOTAS. MODELS SUGGEST
THIS STRONG THETA-E ADVECTION WILL BRUSH NERN IA AROUND MIDDAY.
THERE IS A DECENT AMOUNT OF DRY AIR BELOW 3KM ON THE MASON CITY
SOUNDING...HOWEVER IT IS SATURATED ABOVE AND UVM ASSOCIATED WITH
STRONG WARM ADVECTION OFTEN IS SUFFICIENT TO GET AT LEAST
SOMETHING TO THE SURFACE. FEEL MODEL QPF AND AREAL COVERAGE OF
MEASURABLE POTENTIAL IS OVERDONE...BUT CONFIDENCE IS THERE TO
INTRODUCE A SHORT PERIOD OF SPRINKLES NE CENTERED AROUND 18Z.
FORECAST SOUNDINGS ADJUSTED FOR RECENT MIXING SUGGEST SOMETHING
CLOSE TO A MOS BLEND FOR HIGHS TODAY...WHICH PERFORMED WELL
YESTERDAY.
.LONG TERM.../TONIGHT THROUGH SUNDAY/
ISSUED AT 416 AM CDT MON MAY 13 2013
MAIN FORECAST CONCERN IS WITH HOT TEMPERATURES AND FIRE WEATHER
ON TUESDAY...AND THUNDERSTORM CHANCES LATE IN THE WEEK. LEANED
TOWARD SREF TONIGHT INTO WEDNESDAY AS GFS/NAM/ECMWF ARE TOO COLD
FOR TEMPS TOMORROW.
TONIGHT THROUGH WEDNESDAY...WAA CONTINUES TONIGHT INTO TOMORROW
AHEAD A COLD FRONT AND AREA OF LOW PRESSURE SET TO MOVE ACROSS THE
FORECAST AREA TUESDAY NIGHT. GOOD MIXING TO 900MB TOMORROW AND
POSSIBLY EVEN HIGHER. THIS MAY TAP INTO THE VERY WARM 850MB TEMPS
RANGING FROM 22C TO 25C ACROSS IOWA. WINDS LOOK TO GUST TO AROUND
25-30 KNOTS ACROSS THE NORTH AND SLIGHTLY LESS FURTHER SOUTH. VERY
DRY AIR MASS MOVING INTO THE STATE FROM THE PLAINS AND MODELS NOT
CAPTURING THE CURRENT DEW POINTS TRENDS OVER THIS AREA. FELT
CURRENT FORECAST AND MODELS WERE TOO HIGH FOR SURFACE DEW POINTS
TONIGHT INTO TOMORROW. PLUS WITH THE GOOD MIXING...LEANED TOWARD
LOWERING DEW POINTS 4 TO 6 DEGREES TONIGHT INTO TOMORROW WHICH WAS
FAIRLY CLOSE TO THE 900MB FROM THE NAM12. WITH THE DRIER AIR NOW
FORECAST...LEANED TOWARD INCREASING MAX TEMPS FOR TUESDAY ROUGHLY
1-3 DEGREES ACROSS THE FORECAST AREA. IN SOME PLACES FORECASTING A
RECORD HIGH FOR TOMORROW.
COLD FRONT SHOULD ENTER THE NORTHWEST PORTIONS OF THE FORECAST AREA
BY AROUND 00Z WEDNESDAY AND CONTINUE TO TRACK SOUTH OVERNIGHT INTO
WEDNESDAY MORNING. LIMITED MOISTURE WITH FRONT BUT ENOUGH
INSTABILITY AND FORCING TO KEEP MENTION OF SLIGHT CHANCES GOING
TUESDAY INTO WEDNESDAY. FRONT WASHES OUT ACROSS NORTHERN MISSOURI
DURING THE DAY WEDNESDAY AND MAY SEE A STRAY THUNDERSTORM ALONG
THE BORDER.
THURSDAY THROUGH MONDAY...SURFACE HIGH PRESSURE MOVES BACK IN
OVER THE STATE FOR THURSDAY AND LOOKS TO BE STRONG ENOUGH TO KEEP
CONDITIONS DRY FOR AT LEAST NORTHERN IOWA. ECMWF TRIES TO BRING
MOISTURE NORTHWARD DURING THE DAY AND MAY SEE THUNDERSTORM
ACTIVITY ACROSS THE SOUTH. EXTENDED MODELS IN DECENT AGREEMENT
WITH A SLOW MOVING SURFACE LOW AND UPPER LEVEL TROUGH TO AFFECT
THE PLAINS AND INTO THE CORN BELT FRIDAY INTO THE WEEKEND. BEST
THUNDERSTORM CHANCES IS SATURDAY NIGHT INTO SUNDAY WITH LLJ
DEVELOPING AHEAD OF THE TROUGH.
&&
.AVIATION...13/12Z
ISSUED AT 641 AM CDT MON MAY 13 2013
VFR CONDITIONS ARE ANTICIPATED THROUGHOUT THE PERIOD. BKN-OVC MID
CLOUDS MAY CROSS IA INTO MIDDAY WITH HIGH BASED SHOWERS
NORTHEAST STRUGGLING TO REACH THE GROUND WITH MUCH AREAL COVERAGE.
TONIGHT SHOULD SEE SOME CLEARING WITH LIGHT SOUTH WINDS...BECOMING
SOUTHWESTERLY.
&&
.FIRE WEATHER...
ISSUED AT 416 AM CDT MON MAY 13 2013
FIRE WEATHER CONCERNS ARE INCREASING SOMEWHAT TODAY WITH STRONGER
WIND AND LOW RH DUE TO MIXING. LOCAL AND UPSTREAM SOUNDINGS
INITIALIZED TOO MOIST IN THE LOWEST 1.5KM AT 00Z IN MOST MODELS SO
HAVE DEWPOINTS BELOW MOS AND CONSENSUS. RAP WAS THE DRIEST AND
CLOSEST TO REALITY. DID NOT GO THAT LOW YET BUT LEANED IN THAT
DIRECTION. THIS RESULTED IN MIN RH AROUND 25 PERCENT IN 5-6
COUNTIES W CENTRAL AND NW...BUT SUSTAINED WINDS WILL STAY JUST BELOW
RED FLAG WARNING CRITERIA /25 MPH/. THUS NO HEADLINES TODAY...BUT
WILL MENTION IN HWO AND HIGHLIGHT IN FIRE WEATHER FORECAST. DRYNESS
OF FUELS ALSO SOMEWHAT IN QUESTION OVER NRN IA. USED AS A PROXY FOR
FARTHER WEST WHERE CLIMATE DATA IS MORE QUESTIONABLE...MASON CITY
HAS HAD WETTEST METEOROLOGICAL SPRING TO DATE.
TUESDAY LOOKS TO BE HOTTER AND MUCH DRIER THAN PREVIOUSLY
ANTICIPATED AS MODELS OVERDOING THE SURFACE DEW POINTS ACROSS
CENTRAL IOWA. MIXING UP TO 3000 TO 3500 FEET BY TUESDAY AFTERNOON
WILL RESULT IN DEW POINTS IN THE UPPER 40S TO THE LOWER 50S.
HENCE...RH VALUES ARE FORECAST TO DROP TO 25 PERCENT OR LESS
GENERALLY ALONG AND WEST OF INTERSTATE 35. TEMPS WILL RAPIDLY
INCREASE IN THE MORNING AND THE 25 PERCENT RH VALUES LOOK TO BE
REALIZED BY AROUND NOON. SOUTHWEST WINDS GUSTING TO 30 TO 35 MPH
BY THE AFTERNOON. SO WITH THE LOW RH...GUSTY WINDS...AND HOT
TEMPS...BORDERLINE POTENTIAL FOR A RED FLAG WARNING ACROSS WESTERN
PORTIONS OF THE FORECAST AREA.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...REV
SHORT TERM...SMALL
LONG TERM...PODRAZIK
AVIATION...SMALL
FIRE WEATHER...SMALL/PODRAZIK
AREA FORECAST DISCUSSION
NWS DES MOINES IA
642 AM CDT MON MAY 13 2013
.SHORT TERM.../TODAY/
ISSUED AT 416 AM CDT MON MAY 13 2013
TEMPS AND SUBTLE PRECIP TRENDS WILL BE THE MAIN CONCERN THIS
MORNING. KINEMATIC FORCING ASSOCIATED WITH CANADIAN SHORT WAVE
STILL WELL REMOVED FROM U.S. BORDER WILL REMAIN TO OUR NORTH AND
EAST TODAY. HOWEVER STRONG THERMODYNAMIC FORCING AHEAD OF THIS
FEATURE AND ADVANCING UPPER LEVEL RIDGE IS CURRENTLY PRODUCING
SCATTERED HIGH BASED SHOWERS ACROSS THE DAKOTAS. MODELS SUGGEST
THIS STRONG THETA-E ADVECTION WILL BRUSH NERN IA AROUND MIDDAY.
THERE IS A DECENT AMOUNT OF DRY AIR BELOW 3KM ON THE MASON CITY
SOUNDING...HOWEVER IT IS SATURATED ABOVE AND UVM ASSOCIATED WITH
STRONG WARM ADVECTION OFTEN IS SUFFICIENT TO GET AT LEAST
SOMETHING TO THE SURFACE. FEEL MODEL QPF AND AREAL COVERAGE OF
MEASURABLE POTENTIAL IS OVERDONE...BUT CONFIDENCE IS THERE TO
INTRODUCE A SHORT PERIOD OF SPRINKLES NE CENTERED AROUND 18Z.
FORECAST SOUNDINGS ADJUSTED FOR RECENT MIXING SUGGEST SOMETHING
CLOSE TO A MOS BLEND FOR HIGHS TODAY...WHICH PERFORMED WELL
YESTERDAY.
.LONG TERM.../TONIGHT THROUGH SUNDAY/
ISSUED AT 416 AM CDT MON MAY 13 2013
MAIN FORECAST CONCERN IS WITH HOT TEMPERATURES AND FIRE WEATHER
ON TUESDAY...AND THUNDERSTORM CHANCES LATE IN THE WEEK. LEANED
TOWARD SREF TONIGHT INTO WEDNESDAY AS GFS/NAM/ECMWF ARE TOO COLD
FOR TEMPS TOMORROW.
TONIGHT THROUGH WEDNESDAY...WAA CONTINUES TONIGHT INTO TOMORROW
AHEAD A COLD FRONT AND AREA OF LOW PRESSURE SET TO MOVE ACROSS THE
FORECAST AREA TUESDAY NIGHT. GOOD MIXING TO 900MB TOMORROW AND
POSSIBLY EVEN HIGHER. THIS MAY TAP INTO THE VERY WARM 850MB TEMPS
RANGING FROM 22C TO 25C ACROSS IOWA. WINDS LOOK TO GUST TO AROUND
25-30 KNOTS ACROSS THE NORTH AND SLIGHTLY LESS FURTHER SOUTH. VERY
DRY AIR MASS MOVING INTO THE STATE FROM THE PLAINS AND MODELS NOT
CAPTURING THE CURRENT DEW POINTS TRENDS OVER THIS AREA. FELT
CURRENT FORECAST AND MODELS WERE TOO HIGH FOR SURFACE DEW POINTS
TONIGHT INTO TOMORROW. PLUS WITH THE GOOD MIXING...LEANED TOWARD
LOWERING DEW POINTS 4 TO 6 DEGREES TONIGHT INTO TOMORROW WHICH WAS
FAIRLY CLOSE TO THE 900MB FROM THE NAM12. WITH THE DRIER AIR NOW
FORECAST...LEANED TOWARD INCREASING MAX TEMPS FOR TUESDAY ROUGHLY
1-3 DEGREES ACROSS THE FORECAST AREA. IN SOME PLACES FORECASTING A
RECORD HIGH FOR TOMORROW.
COLD FRONT SHOULD ENTER THE NORTHWEST PORTIONS OF THE FORECAST AREA
BY AROUND 00Z WEDNESDAY AND CONTINUE TO TRACK SOUTH OVERNIGHT INTO
WEDNESDAY MORNING. LIMITED MOISTURE WITH FRONT BUT ENOUGH
INSTABILITY AND FORCING TO KEEP MENTION OF SLIGHT CHANCES GOING
TUESDAY INTO WEDNESDAY. FRONT WASHES OUT ACROSS NORTHERN MISSOURI
DURING THE DAY WEDNESDAY AND MAY SEE A STRAY THUNDERSTORM ALONG
THE BORDER.
THURSDAY THROUGH MONDAY...SURFACE HIGH PRESSURE MOVES BACK IN
OVER THE STATE FOR THURSDAY AND LOOKS TO BE STRONG ENOUGH TO KEEP
CONDITIONS DRY FOR AT LEAST NORTHERN IOWA. ECMWF TRIES TO BRING
MOISTURE NORTHWARD DURING THE DAY AND MAY SEE THUNDERSTORM
ACTIVITY ACROSS THE SOUTH. EXTENDED MODELS IN DECENT AGREEMENT
WITH A SLOW MOVING SURFACE LOW AND UPPER LEVEL TROUGH TO AFFECT
THE PLAINS AND INTO THE CORN BELT FRIDAY INTO THE WEEKEND. BEST
THUNDERSTORM CHANCES IS SATURDAY NIGHT INTO SUNDAY WITH LLJ
DEVELOPING AHEAD OF THE TROUGH.
&&
.AVIATION...13/12Z
ISSUED AT 641 AM CDT MON MAY 13 2013
VFR CONDITIONS ARE ANTICIPATED THROUGHOUT THE PERIOD. BKN-OVC MID
CLOUDS MAY CROSS IA INTO MIDDAY WITH HIGH BASED SHOWERS
NORTHEAST STRUGGLING TO REACH THE GROUND WITH MUCH AREAL COVERAGE.
TONIGHT SHOULD SEE SOME CLEARING WITH LIGHT SOUTH WINDS...BECOMING
SOUTHWESTERLY.
&&
.FIRE WEATHER...
ISSUED AT 416 AM CDT MON MAY 13 2013
FIRE WEATHER CONCERNS ARE INCREASING SOMEWHAT TODAY WITH STRONGER
WIND AND LOW RH DUE TO MIXING. LOCAL AND UPSTREAM SOUNDINGS
INITIALIZED TOO MOIST IN THE LOWEST 1.5KM AT 00Z IN MOST MODELS SO
HAVE DEWPOINTS BELOW MOS AND CONSENSUS. RAP WAS THE DRIEST AND
CLOSEST TO REALITY. DID NOT GO THAT LOW YET BUT LEANED IN THAT
DIRECTION. THIS RESULTED IN MIN RH AROUND 25 PERCENT IN 5-6
COUNTIES W CENTRAL AND NW...BUT SUSTAINED WINDS WILL STAY JUST BELOW
RED FLAG WARNING CRITERIA /25 MPH/. THUS NO HEADLINES TODAY...BUT
WILL MENTION IN HWO AND HIGHLIGHT IN FIRE WEATHER FORECAST. DRYNESS
OF FUELS ALSO SOMEWHAT IN QUESTION OVER NRN IA. USED AS A PROXY FOR
FARTHER WEST WHERE CLIMATE DATA IS MORE QUESTIONABLE...MASON CITY
HAS HAD WETTEST METEOROLOGICAL SPRING TO DATE.
TUESDAY LOOKS TO BE HOTTER AND MUCH DRIER THAN PREVIOUSLY
ANTICIPATED AS MODELS OVERDOING THE SURFACE DEW POINTS ACROSS
CENTRAL IOWA. MIXING UP TO 3000 TO 3500 FEET BY TUESDAY AFTERNOON
WILL RESULT IN DEW POINTS IN THE UPPER 40S TO THE LOWER 50S.
HENCE...RH VALUES ARE FORECAST TO DROP TO 25 PERCENT OR LESS
GENERALLY ALONG AND WEST OF INTERSTATE 35. TEMPS WILL RAPIDLY
INCREASE IN THE MORNING AND THE 25 PERCENT RH VALUES LOOK TO BE
REALIZED BY AROUND NOON. SOUTHWEST WINDS GUSTING TO 30 TO 35 MPH
BY THE AFTERNOON. SO WITH THE LOW RH...GUSTY WINDS...AND HOT
TEMPS...BORDERLINE POTENTIAL FOR A RED FLAG WARNING ACROSS WESTERN
PORTIONS OF THE FORECAST AREA.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...SMALL
LONG TERM...PODRAZIK
AVIATION...SMALL
FIRE WEATHER...SMALL/PODRAZIK
AREA FORECAST DISCUSSION
NWS DES MOINES IA
422 AM CDT MON MAY 13 2013
.SHORT TERM.../TODAY /...
ISSUED AT 416 AM CDT MON MAY 13 2013
TEMPS AND SUBTLE PRECIP TRENDS WILL BE THE MAIN CONCERN THIS
MORNING. KINEMATIC FORCING ASSOCIATED WITH CANADIAN SHORT WAVE
STILL WELL REMOVED FROM U.S. BORDER WILL REMAIN TO OUR NORTH AND
EAST TODAY. HOWEVER STRONG THERMODYNAMIC FORCING AHEAD OF THIS
FEATURE AND ADVANCING UPPER LEVEL RIDGE IS CURRENTLY PRODUCING
SCATTERED HIGH BASED SHOWERS ACROSS THE DAKOTAS. MODELS SUGGEST
THIS STRONG THETA-E ADVECTION WILL BRUSH NERN IA AROUND MIDDAY.
THERE IS A DECENT AMOUNT OF DRY AIR BELOW 3KM ON THE MASON CITY
SOUNDING...HOWEVER IT IS SATURATED ABOVE AND UVM ASSOCIATED WITH
STRONG WARM ADVECTION OFTEN IS SUFFICIENT TO GET AT LEAST
SOMETHING TO THE SURFACE. FEEL MODEL QPF AND AREAL COVERAGE OF
MEASURABLE POTENTIAL IS OVERDONE...BUT CONFIDENCE IS THERE TO
INTRODUCE A SHORT PERIOD OF SPRINKLES NE CENTERED AROUND 18Z.
FORECAST SOUNDINGS ADJUSTED FOR RECENT MIXING SUGGEST SOMETHING
CLOSE TO A MOS BLEND FOR HIGHS TODAY...WHICH PERFORMED WELL
YESTERDAY.
.LONG TERM.../TONIGHT THROUGH SUNDAY/...
ISSUED AT 416 AM CDT MON MAY 13 2013
.MAIN FORECAST CONCERN IS WITH HOT TEMPERATURES AND FIRE WEATHER
ON TUESDAY...AND THUNDERSTORM CHANCES LATE IN THE WEEK. LEANED
TOWARD SREF TONIGHT INTO WEDNESDAY AS GFS/NAM/ECMWF ARE TOO COLD
FOR TEMPS TOMORROW.
.TONIGHT THROUGH WEDNESDAY...WAA CONTINUES TONIGHT INTO
TOMORROW AHEAD A COLD FRONT AND AREA OF LOW PRESSURE SET TO MOVE
ACROSS THE FORECAST AREA TUESDAY NIGHT. GOOD MIXING TO 900MB
TOMORROW AND POSSIBLY EVEN HIGHER. THIS MAY TAP INTO THE VERY WARM
850MB TEMPS RANGING FROM 22C TO 25C ACROSS IOWA. WINDS LOOK TO
GUST TO AROUND 25-30 KNOTS ACROSS THE NORTH AND SLIGHTLY LESS
FURTHER SOUTH. VERY DRY AIR MASS MOVING INTO THE STATE FROM THE
PLAINS AND MODELS NOT CAPTURING THE CURRENT DEW POINTS TRENDS OVER
THIS AREA. FELT CURRENT FORECAST AND MODELS WERE TOO HIGH FOR
SURFACE DEW POINTS TONIGHT INTO TOMORROW. PLUS WITH THE GOOD
MIXING...LEANED TOWARD LOWERING DEW POINTS 4 TO 6 DEGREES TONIGHT
INTO TOMORROW WHICH WAS FAIRLY CLOSE TO THE 900MB FROM THE NAM12.
WITH THE DRIER AIR NOW FORECAST...LEANED TOWARD INCREASING MAX
TEMPS FOR TUESDAY ROUGHLY 1-3 DEGREES ACROSS THE FORECAST AREA. IN
SOME PLACES FORECASTING A RECORD HIGH FOR TOMORROW.
COLD FRONT SHOULD ENTER THE NORTHWEST PORTIONS OF THE FORECAST AREA
BY AROUND 00Z WEDNESDAY AND CONTINUE TO TRACK SOUTH OVERNIGHT INTO
WEDNESDAY MORNING. LIMITED MOISTURE WITH FRONT BUT ENOUGH
INSTABILITY AND FORCING TO KEEP MENTION OF SLIGHT CHANCES GOING
TUESDAY INTO WEDNESDAY. FRONT WASHES OUT ACROSS NORTHERN MISSOURI
DURING THE DAY WEDNESDAY AND MAY SEE A STRAY THUNDERSTORM ALONG
THE BORDER.
.THURSDAY THROUGH MONDAY...SURFACE HIGH PRESSURE MOVES BACK IN
OVER THE STATE FOR THURSDAY AND LOOKS TO BE STRONG ENOUGH TO
KEEP CONDITIONS DRY FOR AT LEAST NORTHERN IOWA. ECMWF TRIES TO
BRING MOISTURE NORTHWARD DURING THE DAY AND MAY SEE THUNDERSTORM
ACTIVITY ACROSS THE SOUTH. EXTENDED MODELS IN DECENT AGREEMENT
WITH A SLOW MOVING SURFACE LOW AND UPPER LEVEL TROUGH TO AFFECT
THE PLAINS AND INTO THE CORN BELT FRIDAY INTO THE WEEKEND. BEST
THUNDERSTORM CHANCES IS SATURDAY NIGHT INTO SUNDAY WITH LLJ
DEVELOPING AHEAD OF THE TROUGH.
&&
.AVIATION...13/06Z
ISSUED AT 1113 PM CDT SUN MAY 12 2013
VFR CONDITIONS TO CONTINUE MONDAY INTO TUESDAY MORNING. CLEAR
SKIES WILL CONTINUE UNTIL AROUND 13Z...WHEN WIDESPREAD HIGH AND MID
LEVEL CLOUDS MOVE OVER IOWA FROM THE NORTHWEST. WINDS WILL BE
LIGHT AND VARIABLE THROUGH SUNRISE...AND THEN OUT OF THE SOUTH AT
AROUND 10 TO 15 KNOTS...WITH SOME GUSTS UPWARDS OF 20 TO 25 KNOTS
BY MONDAY AFTERNOON.
&&
.FIRE WEATHER...
ISSUED AT 416 AM CDT MON MAY 13 2013
FIRE WEATHER CONCERNS ARE INCREASING SOMEWHAT TODAY WITH STRONGER
WIND AND LOW RH DUE TO MIXING. LOCAL AND UPSTREAM SOUNDINGS
INITIALIZED TOO MOIST IN THE LOWEST 1.5KM AT 00Z IN MOST MODELS SO
HAVE DEWPOINTS BELOW MOS AND CONSENSUS. RAP WAS THE DRIEST AND
CLOSEST TO REALITY. DID NOT GO THAT LOW YET BUT LEANED IN THAT
DIRECTION. THIS RESULTED IN MIN RH AROUND 25 PERCENT IN 5-6
COUNTIES W CENTRAL AND NW...BUT SUSTAINED WINDS WILL STAY JUST BELOW
RED FLAG WARNING CRITERIA /25 MPH/. THUS NO HEADLINES TODAY...BUT
WILL MENTION IN HWO AND HIGHLIGHT IN FIRE WEATHER FORECAST. DRYNESS
OF FUELS ALSO SOMEWHAT IN QUESTION OVER NRN IA. USED AS A PROXY FOR
FARTHER WEST WHERE CLIMATE DATA IS MORE QUESTIONABLE...MASON CITY
HAS HAD WETTEST METEOROLOGICAL SPRING TO DATE.
TUESDAY LOOKS TO BE HOTTER AND MUCH DRIER THAN PREVIOUSLY
ANTICIPATED AS MODELS OVERDOING THE SURFACE DEW POINTS ACROSS
CENTRAL IOWA. MIXING UP TO 3000 TO 3500 FEET BY TUESDAY AFTERNOON
WILL RESULT IN DEW POINTS IN THE UPPER 40S TO THE LOWER 50S.
HENCE...RH VALUES ARE FORECAST TO DROP TO 25 PERCENT OR LESS
GENERALLY ALONG AND WEST OF INTERSTATE 35. TEMPS WILL RAPIDLY
INCREASE IN THE MORNING AND THE 25 PERCENT RH VALUES LOOK TO BE
REALIZED BY AROUND NOON. SOUTHWEST WINDS GUSTING TO 30 TO 35 MPH
BY THE AFTERNOON. SO WITH THE LOW RH...GUSTY WINDS...AND HOT
TEMPS...BORDERLINE POTENTIAL FOR A RED FLAG WARNING ACROSS WESTERN
PORTIONS OF THE FORECAST AREA.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...SMALL
LONG TERM...PODRAZIK
AVIATION...KOTENBERG
FIRE WEATHER...SMALL/PODRAZIK
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
619 PM CDT TUE MAY 14 2013
...UPDATED AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 931 AM CDT TUE MAY 14 2013
THE 14.12Z 250 HPA RAOB MAP SHOWED TWO JETS ACROSS NORTH AMERICA. THE
POLAR JET WAS LOCATED ACROSS THE NORTHERN PORTIONS OF UNITED STATES
AND INTO CANADA. THE STRONGEST WINDS WERE LOCATED FROM NOVA SCOTIA AND
INTO THE CANADIAN MARITIMES WITH MAGNITUDES AROUND 180 KT. NEXT, THE
SUBTROPICAL JET WAS LOCATED FARTHER SOUTH WITH HIGHEST MAGNITUDES AROUND
90 KT ACROSS FLORIDA. CLOSER TO KANSAS, FLOW WAS QUITE WEAK AT 15 KT. AT
500 HPA, A TROF WAS MOVING ONSHORE ACROSS CENTRAL CALIFORNIA. DAMPENING
SHORTWAVE RIDGING WAS DOWNSTREAM OF THIS FEATURE ACROSS THE 4 CORNERS
REGION. A WEAK LOW WAS LOCATED ACROSS PORTIONS OF MEXICO. A SHORTWAVE
TROF WAS MOVING ACROSS THE CENTRAL CANADIAN PRAIRIES. AN ELONGATED TROF
WAS LOCATED ACROSS THE NE U.S. AND SE CANADA. AT 700 HPA, TEMPERATURES
ACROSS SW KANSAS WERE FAIRLY WARM (10 DEG C). AT 850 HPA, 25 DEG C AT
KDDC WAS SLIGHTLY UNDER THE +2 STANDARD DEVIATION STATISTICAL MARK.
AT THE SFC, A COLD FRONT WAS LOCATED ACROSS THE NORTHERN PLAINS AND
A SURFACE LEE TROF WAS LOCATED ACROSS FAR WESTERN KANSAS.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 252 PM CDT TUE MAY 14 2013
TONIGHT:
EARLY AFTERNOON VISIBLE SATELLITE IMAGERY SHOWS A FIELD OF CUMULUS HUMILIS
CLOUDS ACROSS NORTHWEST KANSAS. THESE CLOUDS ARE IN ASSOCIATION WITH
A LEE SURFACE TROF ACROSS NORTHWEST KANSAS AND WEAK INSTABILITY. RAP
AND HRRR KEEPS THIS ACTIVITY NORTHWEST OF THE FORECAST AREA OF RESPONSIBILITY
THROUGH TONIGHT. I HAVE 14 PERCENT PRECIPITATION PROBABILITIES IN THE
GRIDS THROUGH EARLY EVENING ACROSS WEST CENTRAL KANSAS. OTHERWISE, TONIGHT
WILL BE CLEAR AND PRECIPITATION FREE. LEE TROUGHING WILL CONTINUE THROUGH
THE OVERNIGHT PERIOD. SOUTHERLY WINDS IN ASSOCIATION WITH THIS FEATURE
WILL CONTINUE OVERNIGHT AS WELL. THESE WINDS WILL KEEP TEMPERATURES
MILD WITH LOWS IN THE UPPER 50S AND LOWER 60S DEG F.
TOMORROW:
ON WEDNESDAY, A LEE INDUCED LOW/TROF ACROSS SOUTHEASTERN COLORADO WILL DEEPEN
THROUGH THE AFTERNOON. THIS WILL CAUSE A WARM FRONT TO LIFT NORTHWARD
ACROSS PORTIONS OF WESTERN KANSAS. HIGHS TOMORROW IN THE WARM SECTOR
WILL BE WARM TO HOT AGAIN WITH HIGHS IN THE 86-91 DEG F RANGE. RAMPED
UP POPS IN THE AFTERNOON ACROSS THE EASTERN PORTIONS OF THE FORECAST
AREA OF RESPONSIBILITY. THERE IS SOME UNCERTAINTY IN WHERE CONVECTION
WILL DEVELOP ALONG THE FRONT AS MODELS DIFFER WITH THE FRONT POSITION.
12Z NAM DEVELOPS THUNDERSTORMS FROM LIBERAL TO HAYS, WHILE 12Z GFS KEEPS
PRECIPITATION MAINLY EAST OF HIGHWAY 183. THE WRF-NMM ECHOES THE NAM
SOLUTION, WHERE THE WRF-ARW KEEPS THE REGION DRY. DUE TO THE UNCERTAINTY,
WILL LIMIT PRECIPITATION PROBABILITIES IN THE SLIGHT CHANCE CATEGORY.
IF THE NAM SOLUTION IS CORRECT WITH MOISTURE, MLCAPE LOOKS TO BE AROUND
1500-3000 J/KG, MAINLY ACROSS SC KANSAS. 0-6 KM BULK SHEAR IS ON THE
WEAKER SIDE AT 30-35 KT. UPPER LEVEL WIND SHEAR IS VERY WEAK AT 15-30
KT. LCL`S WILL BE FAIRLY HIGH AS WELL. PUTTING THIS ALL TOGETHER, THE
OVERALL THREAT FOR HIGH END SEVERE WEATHER IS VERY LOW. THE MAIN THREAT
TOMORROW IS MARGINAL HAIL SIZE PERHAPS UP TO QUARTERS AND 50-60 MPH
OUTFLOW FROM THUNDERSTORMS.
LASTLY, LESS FIRE WEATHER CONCERNS ARE EXPECTED TOMORROW AFTERNOON AS
SLIGHTLY HIGHER DEWPOINTS AND RESULTANT HIGHER RELATIVE HUMIDITIES ARE
EXPECTED.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 354 PM CDT TUE MAY 14 2013
PRECIPITATION CHANCES, SEVERITY, AND COVERAGE WILL BE CHALLENGES IN
THE FORECAST LATE WEEK INTO THE WEEKEND...ALONG WITH AFTERNOON
TEMPERATURES WITH DRYLINE POSITION UNCERTAINTY.
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT:
A LOW AMPLITUDE SHORTWAVE TROUGH (CURRENTLY SEEN ON WATER VAPOR
SPINNING ACROSS CENTRAL CALIFORNIA) WILL BE MOVING TOWARD THE
CENTRAL HIGH PLAINS DURING THIS TIME FRAME. A WEAK FRONT MOVING
INTO EAST-CENTRAL COLORADO AND WEST-CENTRAL KANSAS WILL BE THE FOCUS
FOR THUNDERSTORMS LATE AFTERNOON WEDNESDAY...BUT THIS FRONT WILL
DISSOLVE BY WEDNESDAY NIGHT. A SMALL...LOOSELY ORGANIZED AREA OF
CONVECTION AHEAD OF THE APPROACHING WAVE MAY HOLD TOGETHER AS IT
APPROACHES FAR WEST-CENTRAL KANSAS...BUT CONFIDENCE IN THIS IS VERY
LOW AND ONLY SLIGHT CHANCE POPS ARE WARRANTED AT THIS TIME. ON
THURSDAY...THERE IS A LOT OF DISAGREEMENT ON THE 850MB
THERMODYNAMICS/MOISTURE BETWEEN THE NCEP MODELS AND THE ECMWF MODEL.
THE GFS AND NAM SHOW COPIOUS AMOUNTS OF MOISTURE AND NEAR-SATURATED
RH AT 850MB THROUGH 18Z THURSDAY WHICH IS AFFECTING THE BOUNDARY
LAYER TEMPERATURES TO THE POINT THAT THE NCEP MODELS KEEP
TEMPERATURES IN THE 70S FOR MUCH OF THE DAY. THE NCEP MODELS TEND TO
BE A BIT TOO AGGRESSIVE IN HOLDING ONTO STRATUS TOO LONG SO THE
OFFICIAL FORECAST FOR HIGHS THURSDAY WILL REFLECT MORE CLOSELY THE
ECMWF MODEL.
A DRYLINE WILL NO DOUBT BE A PREVAILING FEATURE, HOWEVER, WHICH
SHOULD FOCUS A FEW ISOLATED STORMS BY LATE AFTERNOON/EARLY
EVENING...ESPECIALLY SINCE THE AFOREMENTIONED LOW AMPLITUDE
SHORTWAVE TROUGH WILL BE PASSING JUST TO THE NORTH AIDING IN SOME
SLIGHT MID LEVEL COOLING AND OVERALL SLIGHT ENHANCEMENT OF DEEP
TROPOSPHERIC UPWARD VERTICAL MOTION. MID LEVEL FLOW AT THE BASE OF
THIS TROUGH AXIS OF 25 TO 35 KNOTS (500MB) ACROSS WESTERN KANSAS
WILL PROVIDE THE NECESSARY SHEAR ALONG WITH SOUTH-SOUTHEAST BOUNDARY
LAYER FLOW FOR SUPERCELL STORMS (ALONG WITH THE UPPER 50S TO NEAR 60
DEWPOINTS AT THE SURFACE). ANY THUNDERSTORMS LATE THURSDAY/THURSDAY
EVENING SHOULD DISSOLVE AFTER SUNSET AS INSOLATION GOES AWAY AND THE
SHORTWAVE TROUGH EXITS THE CENTRAL PLAINS.
FRIDAY AND SATURDAY:
A MUCH MORE IMPRESSIVE PACIFIC JET WILL ENTER THE SOUTHWEST/GREAT
BASIN REGION DURING THIS TIME FRAME...ENTERING THE ROCKIES AND
WESTERN PLAINS SATURDAY. THE DRYLINE WILL BE THE FOCUS FOR
THUNDERSTORMS BOTH OF THESE DAYS...BUT SATURDAY WILL BE THE BETTER
DAY OF THE TWO FOR MORE ORGANIZED SUPERCELL STORMS GIVEN THE GREATER
LOW LEVEL CONVERGENCE EXPECTED ALONG THE DRYLINE NEAR AND JUST SOUTH
OF THE SURFACE LOW. WILL HAVE CHANCE POPS NORTH OF A DIGHTON TO
LACROSSE LINE WHERE THE FORECAST SURFACE LOW WILL BE PER THE ECMWF
MODEL. SOUTH AND SOUTHWEST OF THE SURFACE LOW...HOT TEMPERATURES
WILL BE FOUND OVER A LARGER AREA THAN PREVIOUS DAYS WITH SOME UPPER
90S EVEN POSSIBLE.
SUNDAY AND BEYOND:
THE INITIAL JET STREAK WILL LIFT NORTH INTO THE NORTHERN PLAINS
LEADING TO THE FORMATION OF AN UPPER LOW...HOWEVER AN ENERGETIC JET
WILL STILL REMAIN ACROSS THE GREAT BASIN INTO THE CENTRAL ROCKIES
WHICH COULD LEAD TO DEVELOPMENT OF A SECONDARY LOW LATE SUNDAY INTO
MONDAY. SOME SLIGHT CHANCE POPS WERE INCLUDED THROUGH THE ALLBLEND
GUIDANCE ON SUNDAY AND MONDAY GIVEN THE PROSPECTS OF SOME POTENTIAL
POST-FRONTAL CONVECTION ROLLING EAST OFF THE EASTERN COLORADO
TERRAIN.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 616 PM CDT TUE MAY 14 2013
A SURFACE BOUNDARY LOCATED ACROSS NORTHWEST KANSAS WILL DRIFT
SOUTHEAST OVERNIGHT, AS A COLD FRONT MOVES OUT OF SOUTHERN
NEBRASKA INTO NORTHERN KANSAS. HIGH BASED CONVECTION THAT WAS
PRESENT NEAR THESE BOUNDARIES AT 21Z IS EXPECTED TO DISSIPATE OR
BECOME MORE WIDELY SCATTERED AFTER 00Z BUT A FEW SPRINKLES CAN NOT
BE RULED AT FOR A PERIOD OF TIME IN THE HAYS AREA BETWEEN 03Z AND
06Z. BASED ON BUFR SOUNDINGS THE CLOUD BASES OVERNIGHT WILL BE AT
OR ABOVE 10000FT. GUSTY SOUTH/SOUTHWEST WINDS WILL DECREASE TO
10KTS OR LESS AFTER SUNSET.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 60 89 60 86 / 0 20 20 10
GCK 58 92 59 88 / 10 10 10 20
EHA 56 91 58 92 / 0 10 10 20
LBL 57 92 60 92 / 0 10 10 10
HYS 59 90 60 83 / 10 20 20 10
P28 63 86 63 84 / 0 20 20 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 8 PM CDT THIS EVENING FOR KSZ043>045-
062>064-075>078-084>088.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM...UMSCHEID
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
154 PM EDT MON MAY 13 2013
.SYNOPSIS...
CANADIAN HIGH PRESSURE WILL REMAIN CENTERED OVER THE LOWER
MISSISSIPPI VALLEY TODAY...AS A TROUGH OF LOW PRESSURE PUSHES
THROUGH THE NORTHEAST STATES. THIS PATTERN WILL BRING WELL BELOW
NORMAL TEMPERATURES FOR THE MIDDLE OF MAY. THE HIGH WILL BUILD
INTO THE REGION TONIGHT INTO TUESDAY...AND WILL SLIDE OFF THE
COAST BY TUESDAY NIGHT. MUCH WARMER TEMPERATURES WILL RETURN
WEDNESDAY AND PERSIST INTO THE UPCOMING WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE LATEST SURFACE ANALYSIS SHOWS AN ELONGATED ~1026 MB SURFACE
HIGH SITUATED OVER THE LOWER MS VLY THIS MORNING...WITH A TROUGH
OF LOW PRESSURE DEEPENING OFF THE SC COAST IN RESPONSE TO A STRONG
UPPER TROUGH FROM THE GREAT LAKES SOUTH INTO THE SE CONUS.
MID/HIGH CLOUDS CONTINUE TO OVERSPREAD SE VA/NE NC IN RESPONSE TO
THE LOW OFF THE COAST WHILE MOSTLY SUNNY CONDITIONS PREVAIL
ELSEWHERE...ALTHOUGH THE LATEST VISIBLE IMAGERY INDICATES THE
EARLY STAGES OF CU DEVELOPMENT.
FOR TODAY...A POTENT MID LEVEL SHORTWAVE...CURRENTLY DIVING SOUTH
THROUGH EASTERN OH/WESTERN PA (AND PRODUCING LIGHT SN IN NW PA) WILL
PUSH SSE INTO SOUTH CENTRAL VA AND NE NC BY 00Z THIS EVENING.
WHILE THIS WILL CONTINUE TO DEEPEN THE COASTAL LOW...BULK OF
MOISTURE ASSOCIATED WITH THIS SHOULD STAY OFF THE COAST (PERHAPS
BRINGING A LIGHT SHRA TO THE OUTER BANKS). HOWEVER...DESPITE A
VERY DRY AIRMASS BELOW 800 MB...THE STRONG VORT MAX/PV ANOMALY
DIVES AROUND THE BACK-SIDE OF THE PARENT TROUGH DURING AFTER 18Z
THIS AFTN. THIS IS FORECAST TO DROP 500MB HEIGHTS TO -2 TO -3 ST
DEV BELOW THE MEAN PER 13/00Z GEFS. ADDITIONALLY...LOW AND MID
LEVEL LAPSE RATES WILL BE STEEP WITH COLD AIR ALOFT. GIVEN
THIS...A BKN-OVC SC DECK AROUND 6 K FT IS EXPECTED TO DEVELOP BY
MID AFTERNOON. RADAR WILL PROBABLY SHOW SOME ECHOES ACRS MUCH OF
THE CWA BETWEEN ABOUT 19Z AND 00Z. THE DRY LOW LEVELS (DEW PTS IN
UPPER 20S TO MID 30S) WILL GENLY INHIBIT MUCH OF A CHC FOR
MEASURABLE PRECIP TODAY...BUT GIVEN THE STRONG FORCING AND THE
INCOMING 13/12Z NAM AND HRRR HAVE DECIDED TO CHANGE WEATHER
WORDING FROM PROBABILITY (SLIGHT CHANCE) TO AREAL COVERAGE
(ISOLATED) BUT WILL MAINTAIN A 20 POP. ADDITIONALLY...ISOLATED
POPS HAVE BEEN EXTENDED INTO SE VA/NE NC FOR THE LATE
AFTERNOON/EARLY EVENING BASED ON THE AFOREMENTIONED DATA.
850MB TEMPERATURES DROP TO AROUND -1 C NORTH TO +1 C SOUTH THIS
AFTN...AROUND -2 ST DEV BELOW NORMAL. FULLY MIXED...EXPECT MAX
TEMPS TO RANGE MAINLY FROM THE LOWER TO MID 60S (ABOUT 1.5 TO 2 STD
DEV BELOW SEASONAL MEANS). DAYTIME HIGHS MAY BE REACHED AROUND
MIDDAY BEFORE DROPPING A FEW DEGREES IN THE MID-LATE AFTERNOON AS
CLOUD COVER INCREASES.
NEXT ISSUE WILL BE POTENTIAL RECORD LOWS EARLY TUE MORNING (SEE
CLIMATE SECTION). HAVE ADDED PATCHY FROST TO MUCH OF THE CWA WEST
OF I-95...ALTHOUGH EVEN EAST OF I-95 INTO THE INTERIOR OF SE/E VA
SOME AREAS WILL LIKELY DROP INTO THE UPPER 30S. AT THIS TIME...DE-
COUPLING NOT LIKELY TO OCCUR UNTIL AFTER 06Z...SO DO NOT ANTICIPATE
FROST TO BE WIDESPREAD ENOUGH TO WARRANT A FROST ADSY...ALTHOUGH
IF CLEARING/DE-COUPLING LOOKS TO OCCUR EARLIER...DA SHIFT MAY
CONSIDER ONE FOR PORTIONS OF THE CWA. LOWS IN THE MID TO UPPER 30S
ALONG/WEST OF I-95 AND IN MD...MID 40S IMMEDIATE COAST OF SE VA/NE
NC.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
THE HIGH SLOWLY DRIFTS OVER THE AREA TUESDAY AND THEN OFFSHORE
TUESDAY NIGHT. 850MB TEMPS REMAIN AROUND -2 TO -3 ST DEV BELOW
NORMAL SO HIGHS WILL REMAIN COOL...BUT SHOULD BE SLIGHTLY MILDER
(~ -1.5 ST DEV) DUE TO MORE SOLAR INSOLATION (MAINLY 65-70). HIGH
CLOUDS SHOULD BEGIN TO INCREASE LATER TUESDAY AND ESPECIALLY
TUESDAY NIGHT AS TEMPERATURES ALOFT BEGIN TO INCREASE RAPIDLY AS
RIDGING BUILDS IN FROM THE WEST. MUCH MILDER TUE NIGHT W/ LOWS
PRIMARILY IN THE UPPER 40S TO LWR 50S.
ON WED...SKIES BEGIN PARTLY TO MOSTLY CLOUDY WITH GRADUAL CLEARING
FROM SW TO NE THROUGH THE LATE MORNING AND AFTN. A RATHER DRAMATIC
SHIFT FROM COOL CONDITIONS TUE TO WARMER THAN AVG WX BY WED AFTN AS
850 MB TEMPS WARM BY NEARLY 15 C IN A 24 HR PERIOD. ONLY CAVEAT TO
WARMING TREND COULD BE IF CLOUD COVER DOES NOT BREAK (POSSIBLE
IF A BOUNDARY WERE TO DEVELOP). HIGHS SHOULD RANGE FROM THE UPPER
60S/LWR 70S ALONG THE IMMEDIATE COAST...TO 75-80 IMMEDIATELY
INLAND...TO THE MID 80S ALONG/W OF I-95. WILL NEED TO WATCH
POTENTIAL FOR ISO TSTMS (ESP NORTH) BY LATE AFTN IN WNW FLOW ALOFT
WITH AMPLE CAPE DEVELOPING ACRS THE INTERIOR OF THE CWA (FOR NOW
KEPT FCST MAINLY DRY THRU 00Z/THU).
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
A BOUNDARY WILL LIFT THRU THE REGION AND OFFSHR WED NGT THRU THU
MORNG. AT THIS TIME...WILL HAVE CHC TSRA/SHRA MAINLY OVER NE
SECTIONS OF THE CWA DURING THIS PERIOD. WARM AND SOMEWHAT HUMID
CONDITIONS THEN EXPECTED FOR THU THRU SUN...WITH SLGT OR SML CHCS
FOR MAINLY AFTN/EVENG SHOWERS OR TSTMS...AS WEAK BOUNDARIES OR
TROFS DEVELOP AND MOVE ACRS THE AREA IN WNW FLO ALOFT. MIN TEMPS
WILL MAINLY RANGE FM THE UPR 50S TO LWR 60S THRU THE PERIOD. MAX
TEMPS WILL GENERALLY RANGE FM THE UPR 70S TO MID 80S.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AN UPPER LEVEL TROUGH AXIS WILL SWING A SHORTWAVE ACROSS THE MID
ATLANTIC REGION FROM NW TO SE THROUGH THE REMAINDER OF TODAY INTO
EARLY THIS EVENING. TAF SITES WILL MAINLY EXPERIENCE BKN CIGS AT TO
ABOVE 7000 FT AGL ALTHOUGH VERY LIGHT RAIN SHOWERS CANNOT BE
COMPLETELY RULED OUT DURING THIS TIMEFRAME. IF SHOWERS OCCUR...THEY
WILL HAVE VERY MINIMAL IMPACTS AND WILL KEEP ANY MENTION OUT OF
AREA TAFS. NW-N SFC WINDS WILL BE AROUND 10 KT WITH OCCASIONAL
GUSTS UP TO 20 KT THROUGH AT LEAST 13/2300Z...BUT WINDS ALOFT WILL
BE 20+ KT AND INCREASING WITH HEIGHT OVER THE NEXT 24 HOURS.
UNSETTLED NW FLOW BEHIND THE EXITING TROUGH WILL ALLOW SCT CU TO
DEVELOP LATE TUE MORNING THROUGH TUE AFTN (ONCE AGAIN AROUND
7000 FT AGL). AN UPSTREAM HIGH/THIN CIRRUS SHIELD FROM A LOW IN
THE UPPER GREAT LAKES REGION SHOULD ALSO BE ABLE TO STREAM ACROSS
THE REGION ON TUE. AS THIS SYSTEM MOVES INTO SE CANADA ON WED...A
BOUNDARY WILL BE DRAGGED ACROSS THE REGION AND MAY PROVIDE JUST
ENOUGH INSTABILITY FOR AFTN SHOWERS AND THUNDERSTORMS.
&&
.MARINE...
SCA OVER THE BAY WILL BE ALLOWED TO EXPIRE AT 4 AM AS WINDS
ASSOCIATED WITH A WEAK SURGE ARE NOW STARTING TO FALL TO 10-15 KT.
THESE WINDS WILL CONTINUE THRU THE DAY TDY AS SFC HI PRES SLOWLY
BLDS TOWARDS THE REGION. NWRLY FLOW PERSISTS TNGT WITH THE HI
CENTERED JUST WEST OF THE AREA...AND EXPECT ANOTHER ROUND OF 15-20
KT WINDS OVER THE BAY WITH YET ANOTHER SURGE. SCA TIMING WILL BE
FROM 7 PM TO 7 AM TUE MRNG. EXPECT 15-20 KT OVER COASTAL WATERS AS
WELL WITH 3-4 FT SEAS. HI PRES MOVES DIRECTLY OVER THE AREA TUE AFTN
WITH WINDS AOB 10 KT. SOUTHERLY FLOW RETURNS TUE NGT AND WED AS THE
HI SLIDES OFFSHORE. SEAS WILL APPROACH 5 FT OVER NORTHERN COASTAL
WATERS. ANOTHER FRNT DROPS INTO THE AREA DURING THE SECOND HALF OF
THIS WEEK WITH GENRLY SUB-SCA CONDS EXPECTED.
&&
.CLIMATE...
RECORD LOW TEMPERATURES WILL BE POSSIBLE TUESDAY MORNING (MAY 14TH):
RECORD LOWS FOR MAY 14TH:
RICHMOND....40 (1941)
NORFOLK.....43 (2007)
SALISBURY...32 (2007)
ELIZ CITY...41 (2007)
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 7 AM EDT
TUESDAY FOR ANZ630>632-634.
&&
$$
SYNOPSIS...LKB
NEAR TERM...AJZ/LKB
SHORT TERM...AJZ/LKB
LONG TERM...TMG
AVIATION...BMD
MARINE...MAS
CLIMATE...AKQ
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
1041 AM EDT MON MAY 13 2013
.SYNOPSIS...
CANADIAN HIGH PRESSURE WILL REMAIN CENTERED OVER THE LOWER
MISSISSIPPI VALLEY TODAY...AS A TROUGH OF LOW PRESSURE PUSHES
THROUGH THE NORTHEAST STATES. THIS PATTERN WILL BRING WELL BELOW
NORMAL TEMPERATURES FOR THE MIDDLE OF MAY. THE HIGH WILL BUILD
INTO THE REGION TONIGHT INTO TUESDAY...AND WILL SLIDE OFF THE
COAST BY TUESDAY NIGHT. MUCH WARMER TEMPERATURES WILL RETURN
WEDNESDAY AND PERSIST INTO THE UPCOMING WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE LATEST SURFACE ANALYSIS SHOWS AN ELONGATED ~1026 MB SURFACE
HIGH SITUATED OVER THE LOWER MS VLY THIS MORNING...WITH A TROUGH
OF LOW PRESSURE DEEPENING OFF THE SC COAST IN RESPONSE TO A STRONG
UPPER TROUGH FROM THE GREAT LAKES SOUTH INTO THE SE CONUS.
MID/HIGH CLOUDS CONTINUE TO OVERSPREAD SE VA/NE NC IN RESPONSE TO
THE LOW OFF THE COAST WHILE MOSTLY SUNNY CONDITIONS PREVAIL
ELSEWHERE...ALTHOUGH THE LATEST VISIBLE IMAGERY INDICATES THE
EARLY STAGES OF CU DEVELOPMENT.
FOR TODAY...A POTENT MID LEVEL SHORTWAVE...CURRENTLY DIVING SOUTH
THROUGH EASTERN OH/WESTERN PA (AND PRODUCING LIGHT SN IN NW PA) WILL
PUSH SSE INTO SOUTH CENTRAL VA AND NE NC BY 00Z THIS EVENING.
WHILE THIS WILL CONTINUE TO DEEPEN THE COASTAL LOW...BULK OF
MOISTURE ASSOCIATED WITH THIS SHOULD STAY OFF THE COAST (PERHAPS
BRINGING A LIGHT SHRA TO THE OUTER BANKS). HOWEVER...DESPITE A
VERY DRY AIRMASS BELOW 800 MB...THE STRONG VORT MAX/PV ANOMALY
DIVES AROUND THE BACK-SIDE OF THE PARENT TROUGH DURING AFTER 18Z
THIS AFTN. THIS IS FORECAST TO DROP 500MB HEIGHTS TO -2 TO -3 ST
DEV BELOW THE MEAN PER 13/00Z GEFS. ADDITIONALLY...LOW AND MID
LEVEL LAPSE RATES WILL BE STEEP WITH COLD AIR ALOFT. GIVEN
THIS...A BKN-OVC SC DECK AROUND 6 K FT IS EXPECTED TO DEVELOP BY
MID AFTERNOON. RADAR WILL PROBABLY SHOW SOME ECHOES ACRS MUCH OF
THE CWA BETWEEN ABOUT 19Z AND 00Z. THE DRY LOW LEVELS (DEW PTS IN
UPPER 20S TO MID 30S) WILL GENLY INHIBIT MUCH OF A CHC FOR
MEASURABLE PRECIP TODAY...BUT GIVEN THE STRONG FORCING AND THE
INCOMING 13/12Z NAM AND HRRR HAVE DECIDED TO CHANGE WEATHER
WORDING FROM PROBABILITY (SLIGHT CHANCE) TO AREAL COVERAGE
(ISOLATED) BUT WILL MAINTAIN A 20 POP. ADDITIONALLY...ISOLATED
POPS HAVE BEEN EXTENDED INTO SE VA/NE NC FOR THE LATE
AFTERNOON/EARLY EVENING BASED ON THE AFOREMENTIONED DATA.
850MB TEMPERATURES DROP TO AROUND -1 C NORTH TO +1 C SOUTH THIS
AFTN...AROUND -2 ST DEV BELOW NORMAL. FULLY MIXED...EXPECT MAX
TEMPS TO RANGE MAINLY FROM THE LOWER TO MID 60S (ABOUT 1.5 TO 2 STD
DEV BELOW SEASONAL MEANS). DAYTIME HIGHS MAY BE REACHED AROUND
MIDDAY BEFORE DROPPING A FEW DEGREES IN THE MID-LATE AFTERNOON AS
CLOUD COVER INCREASES.
NEXT ISSUE WILL BE POTENTIAL RECORD LOWS EARLY TUE MORNING (SEE
CLIMATE SECTION). HAVE ADDED PATCHY FROST TO MUCH OF THE CWA WEST
OF I-95...ALTHOUGH EVEN EAST OF I-95 INTO THE INTERIOR OF SE/E VA
SOME AREAS WILL LIKELY DROP INTO THE UPPER 30S. AT THIS TIME...DE-
COUPLING NOT LIKELY TO OCCUR UNTIL AFTER 06Z...SO DO NOT ANTICIPATE
FROST TO BE WIDESPREAD ENOUGH TO WARRANT A FROST ADSY...ALTHOUGH
IF CLEARING/DE-COUPLING LOOKS TO OCCUR EARLIER...DA SHIFT MAY
CONSIDER ONE FOR PORTIONS OF THE CWA. LOWS IN THE MID TO UPPER 30S
ALONG/WEST OF I-95 AND IN MD...MID 40S IMMEDIATE COAST OF SE VA/NE
NC.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
THE HIGH SLOWLY DRIFTS OVER THE AREA TUESDAY AND THEN OFFSHORE
TUESDAY NIGHT. 850MB TEMPS REMAIN AROUND -2 TO -3 ST DEV BELOW
NORMAL SO HIGHS WILL REMAIN COOL...BUT SHOULD BE SLIGHTLY MILDER
(~ -1.5 ST DEV) DUE TO MORE SOLAR INSOLATION (MAINLY 65-70). HIGH
CLOUDS SHOULD BEGIN TO INCREASE LATER TUESDAY AND ESPECIALLY
TUESDAY NIGHT AS TEMPERATURES ALOFT BEGIN TO INCREASE RAPIDLY AS
RIDGING BUILDS IN FROM THE WEST. MUCH MILDER TUE NIGHT W/ LOWS
PRIMARILY IN THE UPPER 40S TO LWR 50S.
ON WED...SKIES BEGIN PARTLY TO MOSTLY CLOUDY WITH GRADUAL CLEARING
FROM SW TO NE THROUGH THE LATE MORNING AND AFTN. A RATHER DRAMATIC
SHIFT FROM COOL CONDITIONS TUE TO WARMER THAN AVG WX BY WED AFTN AS
850 MB TEMPS WARM BY NEARLY 15 C IN A 24 HR PERIOD. ONLY CAVEAT TO
WARMING TREND COULD BE IF CLOUD COVER DOES NOT BREAK (POSSIBLE
IF A BOUNDARY WERE TO DEVELOP). HIGHS SHOULD RANGE FROM THE UPPER
60S/LWR 70S ALONG THE IMMEDIATE COAST...TO 75-80 IMMEDIATELY
INLAND...TO THE MID 80S ALONG/W OF I-95. WILL NEED TO WATCH
POTENTIAL FOR ISO TSTMS (ESP NORTH) BY LATE AFTN IN WNW FLOW ALOFT
WITH AMPLE CAPE DEVELOPING ACRS THE INTERIOR OF THE CWA (FOR NOW
KEPT FCST MAINLY DRY THRU 00Z/THU).
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
A BOUNDARY WILL LIFT THRU THE REGION AND OFFSHR WED NGT THRU THU
MORNG. AT THIS TIME...WILL HAVE CHC TSRA/SHRA MAINLY OVER NE
SECTIONS OF THE CWA DURING THIS PERIOD. WARM AND SOMEWHAT HUMID
CONDITIONS THEN EXPECTED FOR THU THRU SUN...WITH SLGT OR SML CHCS
FOR MAINLY AFTN/EVENG SHOWERS OR TSTMS...AS WEAK BOUNDARIES OR
TROFS DEVELOP AND MOVE ACRS THE AREA IN WNW FLO ALOFT. MIN TEMPS
WILL MAINLY RANGE FM THE UPR 50S TO LWR 60S THRU THE PERIOD. MAX
TEMPS WILL GENERALLY RANGE FM THE UPR 70S TO MID 80S.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
VFR THRU THE TAF PERIOD. MSTLY CLR THIS MRNG AT RIC/SBY WITH
STRATOCU AT ORF/PHF/ECG. THE CLDS SHUD PERSIST THRU THE DAY...AT
6-8K FT. OTW...NORTH WINDS ~10 KT TDY AS SFC HI PRES SLOWLY BLDS
IN FROM THE WEST.
OUTLOOK...VFR AND MAINLY DRY CONDS CONTINUE THIS WEEK WITH LO
DEWPTS MAKING FOG UNLIKELY. THERE WILL BE A CHANCE FOR AFTN
SHWRS/TSTMS THURSDAY AND FRIDAY.
&&
.MARINE...
SCA OVER THE BAY WILL BE ALLOWED TO EXPIRE AT 4 AM AS WINDS
ASSOCIATED WITH A WEAK SURGE ARE NOW STARTING TO FALL TO 10-15 KT.
THESE WINDS WILL CONTINUE THRU THE DAY TDY AS SFC HI PRES SLOWLY
BLDS TOWARDS THE REGION. NWRLY FLOW PERSISTS TNGT WITH THE HI
CENTERED JUST WEST OF THE AREA...AND EXPECT ANOTHER ROUND OF 15-20
KT WINDS OVER THE BAY WITH YET ANOTHER SURGE. SCA TIMING WILL BE
FROM 7 PM TO 7 AM TUE MRNG. EXPECT 15-20 KT OVER COASTAL WATERS AS
WELL WITH 3-4 FT SEAS. HI PRES MOVES DIRECTLY OVER THE AREA TUE AFTN
WITH WINDS AOB 10 KT. SOUTHERLY FLOW RETURNS TUE NGT AND WED AS THE
HI SLIDES OFFSHORE. SEAS WILL APPROACH 5 FT OVER NORTHERN COASTAL
WATERS. ANOTHER FRNT DROPS INTO THE AREA DURING THE SECOND HALF OF
THIS WEEK WITH GENRLY SUB-SCA CONDS EXPECTED.
&&
.CLIMATE...
RECORD LOW TEMPERATURES WILL BE POSSIBLE TUESDAY MORNING (MAY 14TH):
RECORD LOWS FOR MAY 14TH:
RICHMOND....40 (1941)
NORFOLK.....43 (2007)
SALISBURY...32 (2007)
ELIZ CITY...41 (2007)
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 7 AM EDT
TUESDAY FOR ANZ630>632-634.
&&
$$
SYNOPSIS...LKB
NEAR TERM...LKB/AJZ
SHORT TERM...AJZ/LKB
LONG TERM...TMG
AVIATION...MAS
MARINE...MAS
CLIMATE...AKQ
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
711 PM EDT TUE MAY 14 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 422 PM EDT TUE MAY 14 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A ZONAL MID/UPPER LEVEL
PATTERN ACROSS THE NRN CONUS WITH A PROMINENT SHORTWAVE TROUGH NEAR
WINNIPEG. AT THE SFC...A 992 MB LOW WAS ALSO LOCATED OVER SE
MANITOBA WITH A COLD FRONT THROUGH NW MN INTO ERN SD. A WARM FRONT
STRETCHED FROM CNTRL MN INTO SRN WI. RADAR INDICATED WEAK RETURNS
WITH VERY LIGHT SHOWERS(VIRGA OR SPRINKLES) THROUGH CNTRL UPPER MI
AS THE BAND OF 310K (750-600 MB)ISENTROPIC LIFT MOVES THROUGH THE
AREA. SATELLITE SHOWED SKIES CLEARING OVER THE WEST AS DRIER AIR
BEHIND THE PCPN BAND MOVES IN.
TONIGHT...MODELS SUGGEST THAT AS THE MID LEVEL SHRTWV TROUGH AND
ASSOCIATED SFC TROUGH MOVES THROUGH UPPER MI SOME SHOWERS MAY
DEVELOP...MAINLY ACROSS NRN LAKE SUPERIOR AND POSSIBLY INTO THE NRN
PORTIONS OF UPPER MI ON THE SRN TAIL OF THE STRONGER QVECTOR CONV
AND FAVORABLE ISENTROPIC ASCENT JUST AHEAD OF THE SFC TROUGH. MUCAPE
VALUES (LIFTING FROM NEAR 750 MB) OF 500-1000 J/KG STILL SUPPORT A
CONDITIONAL THREAT OF TSRA. ALTHOUGH EFFECTIVE SHEAR VALUES ARE
MARGINAL (20-30 KT) SOME SMALL HAIL MAY BE POSSIBLE WITH ANY TSRA
THAT DEVELOP. CONFIDENCE IN SHRA/TSRA DEVELOPMENT IS LIMITED AS
MODELS HAVE TRENDED TOO HIGH WITH LOW LEVEL MOISTURE AVAILABILITY.
SO...ONLY LOWER END CHANCE POPS WERE INCLUDED.
WED...MODEL SOUNDINGS SHOW STRONG MID-LVL DRYING/SUBSIDENCE IN THE WAKE OF
THE COLD FRONT AS 850 MB TEMPS DROP TO AROUND 5C EARLY WED BUT
REBOUND TO TO AROUND 8C-9C WED AFTERNOON. MIXING HEIGHTS ABOVE 800
MB SHOULD MIX A SIGNIFICANT ENOUGH PORTION OF THE VERY DRY 800-650 MB
LAYER TO DROP DEWPOINTS INLAND TO AROUND 30F. WITH TEMPS INTO THE
LOWER TO MID 70S...RH VALUES WILL DROP TO AROUND 20 PERCENT. NW WIND
SHOULD ALSO INCREASE TO AROUND 15 MPH WITH GUSTS OF 20-25 MPH IN THE
AFTERNOON. SO...A FIRE WEATHER WATCH WAS ISSUED FOR MOST OF INLAND
WEST AND CENTRAL UPPER MICHIGAN.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 444 PM EDT TUE MAY 14 2013
OUR STRONGER WINDS WILL QUICKLY DIMINISH WEDNESDAY NIGHT...EVEN WITH
A REINFORCING SFC TROUGH STRETCHED W-E OVER LAKE SUPERIOR AT 06Z
THURSDAY SINKING SE ACROSS EASTERN UPPER MI BY 12Z THURSDAY. WITH
THAT RH VALUES SHOULD QUICKLY REBOUND TO 35 PERCENT OR BETTER BY 03Z
THURSDAY.
BEHIND THE EXITING TROUGH...HIGH PRESSURE SITUATED OVER S CENTRAL
CANADA WEDNESDAY NIGHT WILL PUSH ACROSS THE CWA AND BE DIRECTLY
OVERHEAD DURING THE DAY THURSDAY...BEFORE SLOWLY EXITING EASTERN
UPPER MI/LAKE SUPERIOR THURSDAY NIGHT INTO FRIDAY.
THURSDAY WILL BE DRY ONCE AGAIN FOR SOUTH CENTRAL AREAS...AND IN
PARTICULAR GOGEBIC...ONTONAGON...IRON...AND DICKINSON COUNTIES.
WINDS WILL BE MUCH LIGHTER THAN WEDNESDAY GIVEN THE DIMINISHED
PRESSURE GRADIENT...AVERAGING 5-10KTS. A WILDFIRE POTENTIAL
STATEMENT MAY BE NEEDED...BUT IS REALLY MARGINAL GIVEN THE NEAR
NORMAL TEMPS FOR THIS TIME OF YEAR...AND LIGHTER WINDS. THE WINDS
ARE THE MAIN THREAT THIS TIME OF YEAR...GIVEN THAT THE MAIN CARRIER
OF FIRES IS THE DRY GRASSES.
THE LINGERING HIGH OVER THE EAST WILL KEEP DRIER AIR IN
PLACE...LIMITING THE POTENTIAL FOR ANY SHOWERS TO MOVE MUCH EAST OF
A LINE FROM MQT TO ESC UNTIL SATURDAY MORNING.
EXPECT INCREASED S FLOW STARTING FRIDAY NIGHT...IN ADVANCE OF A
NEARING LOW DEVELOPING ACROSS THE CENTRAL PLAINS STATES. SEVERAL
WARMER NIGHTS ARE FIGURED WITH MID 40S FOR LOWS FRIDAY NIGHT...NEAR
50F SATURDAY NIGHT AND AGAIN SUNDAY NIGHT. THE LATEST TREND IS TO
MINIMIZE THE POTENTIAL FOR THUNDERSTORM ACTIVITY UNTIL THE SFC LOW
AND 500MB TROUGH GET A BIT CLOSER TO THE CWA...AROUND OR AFTER THE
SUNDAY TIME PERIOD. EXPECT THE ELONGATED LOW STRETCHING FROM
NORTHEAST MN TO N TX AT 18Z SUNDAY /ECMWF FARTHEST EAST/ TO
CONSOLIDATE OVER WESTERN UPPER MICHIGAN SUNDAY EVENING. THE 12Z GFS
DOES NOT BRING THE LOW TO WESTERN UPPER MI UNTIL TUESDAY. NEEDLESS
TO SAY THIS WILL BE A SLOW MOVING SYSTEM...WITH SEVERAL ROUNDS OF
PRECIP ROTING INTO THE REGION. WILL GO WITH A MODEL CONSENSUS BEYOND
SUNDAY...GIVEN THE LARGER DISCREPANCIES.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 711 PM EDT TUE MAY 14 2013
VFR CONDITIONS SHOULD PREVAIL AT ALL THREE TAF SITES THROUGH THE
FORECAST PERIOD. ANOTHER ROUND OF ISOLD SHRA POSSIBLE THIS
EVENING AS PRIMARY SFC FRONT ARRIVES. PLENTY OF DRY AIR REMAINS OVER
THE AREA WHICH MAY INHIBIT DEVELOPMENT. SHARP DRYING/CLEARING
OVERNIGHT TONIGHT. WILL ALSO SEE GUSTY WEST WINDS IN WAKE OF THE
FRONT...STRONGEST AT THE MORE EXPOSED KCMX.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 422 PM EDT TUE MAY 14 2013
SOUTHERLY FLOW WAS INCREASING AHEAD OF A LOW PRESSURE SYSTEM MOVING
EAST THROUGH SOUTHERN CANADA. WINDS INCREASE TO 25 KTS TONIGHT INTO WED
BUT WILL BE LIMITED AS LOW LEVEL WARM AIR ADVECTION RESULTS IN
INCREASING STABILITY. WINDS ARE EXPECTED TO REMAIN BELOW
30KTS LATER THIS WEEK AND INTO THE WEEKEND. AFTER COOL AND WINTRY
WEATHER FOR THE SPRING SO FAR...SUMMERTIME WEATHER IS BECOMING MORE
COMMON. THUNDERSTORMS ARE POSSIBLE TONIGHT AND ENDING BY
EARLY WEDNESDAY. ANOTHER ROUND OF THUNDERSTORMS WILL BE POSSIBLE
WEST ON SATURDAY/SATURDAY NIGHT...AND ACROSS ALL OF LAKE SUPERIOR
SUNDAY THROUGH MONDAY MORNING.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FIRE WEATHER WATCH FROM WEDNESDAY AFTERNOON THROUGH WEDNESDAY
EVENING FOR MIZ002-004>006-009>014-084-085.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
352 PM EDT MON MAY 13 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 351 PM EDT MON MAY 13 2013
TWO WAVES/DISTURBANCES WILL BE THE FOCUS FOR THE FORECAST...WITH
THE FIRST ONE AFFECTING THE AREA TONIGHT AND THE OTHER TOMORROW
AFTERNOON/EVENING.
LATEST WV IMAGERY AND RUC ANALYSIS SHOWS THE AREA UNDER RIDGING
ALOFT AS THE UPPER TROUGH THAT HAD BEEN AFFECTING THE AREA THIS
WEEKEND SHIFTING EAST ACROSS QUEBEC AND AN UPPER RIDGE OVER THE
WESTERN CONUS. THERE IS A DECENT AMOUNT OF MOISTURE ROUNDING THE
RIDGE WITH A 996MB LOW JUST TO THE WEST OF LAKE WINNIPEG. CLOSER TO
HOME...SKIES WERE CLEAR OVER MUCH OF UPPER MICHIGAN THIS
MORNING...BUT INCREASING MID-HIGH CLOUDS ARE SPREADING ACROSS THE
AREA THIS AFTERNOON. BAND OF RAIN IS STARTING TO MOVE INTO WESTERN
LAKE SUPERIOR AT THIS TIME AND IS ASSOCIATED WITH A THIN AREA OF
800-500MB MOISTURE AND 700MB F-GEN.
EXPECT THE BAND TO CONTINUE EAST-SOUTHEAST THIS EVENING AS THE
700MB F-GEN AND BROAD 850-700MB WARM AIR ADVECTION CONTINUE.
BUT...WITH THE 500MB SHORTWAVE AND ASSOCIATED HEIGHT FALLS SHIFTING
EAST THROUGH ONTARIO AND WELL NORTH OF THE AREA ALONG WITH BEING
UNDER THE WRONG AREA OF THE UPPER JET /RIGHT EXIT/ THE BETTER
FORCING ISN/T OVER THE AREA. PLUS...WITH THE DRY AIR IT WILL BE
RUNNING INTO...WONDERING IF THAT WILL LIMIT THE INTENSITY SOME.
WITH AS PERSISTENT AS IT HAS BEEN TODAY...DID BUMP UP POPS A
TOUCH TO GET MORE CHANCE/SCATTERED WORDING IN FOR THIS
EVENING...BUT BASED OFF THE LIMITED RAIN AMOUNTS SEEN UPSTREAM
/TRACE TO A COUPLE HUNDREDTHS/ DIDN/T WANT TO GO MUCH ABOVE THAT. AS
ADDITIONAL 850-700MB MOISTURE SLIDES SOUTHEAST ACROSS THE EASTERN
CWA TONIGHT...WOULD THINK THE PRECIPITATION CHANCES SHOULD INCREASE
SOME OVERNIGHT. THERE IS LITTLE OR NO INSTABILITY WITH THIS PASSING
WAA...AS MID LEVEL LAPSE RATES ARE ONLY AROUND 3-5 C/KM...SO WILL
KEEP THUNDER OUT OF THE FORECAST. WITH THE BETTER CONSISTENCY IN
THIS MOISTURE ARRIVING OVER THE EAST...DID BUMP UP VALUES TO HIGH
CHANCE POPS THERE.
EXPECT TO SEE A BRIEF REPRIEVE ON TUESDAY MORNING BEHIND THE INITIAL
AREA OF WAA TONIGHT. THIS WILL LIKELY PRODUCE SOME BREAKS OR
CLEARING OVER AT LEAST THE WEST HALF OF THE CWA DURING THE MORNING
HOURS BEFORE MID-HIGH CLOUDS STREAM BACK INTO THE AREA. THEN...THE
SHORTWAVE THAT IS CURRENTLY ENTERING THE PACIFIC NORTHWEST WILL BE
MOVING EAST-NORTHEAST ALONG THE US/CANADIAN BORDER AND BE NEAR LAKE
WINNIPEG BY 18Z TUESDAY. WARM AIR ADVECTION WILL AGAIN BE ON THE
INCREASE FROM WEST TO EAST DURING THE AFTERNOON. MOISTURE WILL ALSO
BE LIMITED AS IT MOVES THROUGH THE AREA DURING THE AFTERNOON. BEST
MOISTURE AND CLOSEST PROXIMITY TO THE SHORTWAVE WILL BE OVER THE
NORTHWEST HALF OF THE CWA...SO WILL HAVE HIGHEST POPS THEIR DURING
THE LATTER PART OF THE AFTERNOON. QPF/REFLECTIVITY FROM HIGH
RESOLUTION MODEL RUNS SEEM TO MATCH THIS IDEA AND LEADS TO GREATER
CONFIDENCE.
ELEVATED INSTABILITY IS MARGINAL ALONG/NORTH THE WARM FRONT...WITH
THE BEST INSTABILITY FARTHER SOUTHWEST AND AHEAD OF THE COLD
FRONT. THIS IS LARGELY DUE TO THE MID-LEVEL LAPSE RATES STRUGGLING
TO GET ABOVE 6C/KM. THUS...THUNDER POTENTIAL WILL BE SLIM THROUGH
THE AFTERNOON HOURS. IF ANY ELEVATED THUNDERSTORMS
DEVELOP...WOULDN/T EXPECT THEM TO BE TOO STRONG...AS EFFECTIVE SHEAR
VALUES WILL LIKELY BE BELOW 30KTS THROUGH 00Z ACROSS ALL BUT THE FAR
SOUTHWEST CWA.
AFTER A COOL WEEKEND...TEMPERATURES HAVE STARTED TO REBOUND TODAY
AND EXPECT IT TO CONTINUE ON TUESDAY. THE WARM AIR ADVECTING INTO
THE AREA ON TUESDAY ALONG WITH INCREASING SOUTHERLY FLOW SHOULD LEAD
TO HIGHS IN THE LOWER 70S OVER THE FAR WEST AND A GRADIENT TO THE
50S OVER THE EAST HALF.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 351 PM EDT MON MAY 13 2013
MUCH OF THIS PERIOD WILL BE MARKED BY THE PRESENCE OF A 70KT OR
GREATER 250MB JET OVER UPPER MICHIGAN AND/OR LAKE SUPERIOR...AT
LEAST FROM TUESDAY NIGHT THROUGH SATURDAY MORNING. THIS WILL KEEP
THE AREA IN A RELATIVELY BUSY WEATHER PATTERN...IN BETWEEN THE DOME
OF HOT AIR OVER MUCH OF THE WESTERN HALF OF THE NATION...AND COLDER
AIR RESIDING OVER CANADA.
WE WILL START OUT TUESDAY NIGHT WITH A STACKED 500MB TROUGH-SFC LOW
SET UP JUST NORTH OF CYRL IN WESTERN MANITOBA. A COLD FRONT WILL
EXTEND S FROM THE SFC LOW...THROUGH THE EASTERN THIRD OF MN TO A
SECONDARY SFC LOW/TRIPLE POINT THAT MAY BE DEVELOPING NEAR KDLH.
THE LOCATION OF THE WARM FRONT IS KEY...LIKELY SET UP FROM THE
ARROWHEAD OF MN DOWN AND NEAR THE WI BORDER OF UPPER MI AT 00Z
WEDNESDAY. AS IS TYPICAL...THESE SPLITTING SYSTEMS CAN DEVELOP AND
ROB US OF MOISTURE...AS CONVECTION POPS UP OVER WI. EXPECT
WAA...LIMITED FORCING WILL LIKELY PERSIST...WITH MUCH OF THE BEST
FORCING CLOSER TO THE MAIN SFC/500MB TROUGH ACROSS ONTARIO /WHERE AN
AVERAGE QUARTER OF AN INCH OR MORE OF RAIN IS EXPECTED/. WE LOOK TO
BE IN A PRETTY CAPPED ENVIRONMENT...WITH THE BEST CHANCE FOR ANY
STRONGER SHOWERS OR THUNDERSTORMS OVER SOUTH CENTRAL AND EASTERN
UPPER MI DURING THE LATE EVENING HOURS...AND EVEN THEN LIKELY
ELEVATED ABOVE THE DRY AIR. THE SOUTHERN LOW/COLD FRONT WILL BE OVER
EASTERN UPPER MI/LAKE SUPERIOR BY 09Z WEDNESDAY...AND EAST OF UPPER
MI BY 12Z.
COOLER/DRIER AIR WILL SWEEP IN FOR WEDNESDAY...WITH 850MB TEMPS
FALLING FROM A MAX 14-18C OVERNIGHT TO AN AVERAGE 7-8C DURING THE
DAY WEDNESDAY. PW VALUES FALL TO 0.37 TO 0.44IN...OR 60-70 PERCENT
OF NORMAL...WITH THE LOWEST VALUES AWAY FROM THE KEWEENAW PENINSULA
AND EXTREME S CENTRAL UPPER MI. EXPECT A MORE MODERATED AIRMASS FROM
MUNISING EASTWARD AS MORE MOIST AIR SLIDES IN NEAR THE SHORELINE. A
WORST CASE SCENARIO...WITH THE NAM MIXING UP TO 650-700MB DURING THE
AFTERNOON HOURS...DEW POINTS MIXING DOWN INTO THE UPPER 20S
/F/ WOULD RESULT IN AFTERNOON MIN RH VALUES OF 19-25 PERCENT FROM
JUST E OF IWD TO NORTHERN DELTA COUNTY...WITH GUSTS 25-30KTS. ON A
POSITIVE NOTE...THE LATEST MODEL RUNS ARE NOT QUITE AS STRONG WITH
THE WINDS. WILL NEED TO WAIT AND SEE IF THIS TREND HOLDS. IF
LIMITED...OR NO...PRECIPITATION FALLS TUESDAY NIGHT...FIRE CONCERNS
WILL BE ELEVATED.
BEHIND THE ELONGATED LOW SHIFTING EAST INTO QUEBEC WEDNESDAY
NIGHT...DRY WEATHER WILL REMAIN THROUGH FRIDAY MORNING...WITH COOL
WEST TO NORTHWEST FLOW LINGERING. EXPECT THE RIDGE OF HIGH PRESSURE
TO BE DIRECTLY OVERHEAD ON THURSDAY...WITH LIGHT WINDS AND LAKE
BREEZES EXPECTED.
OUR NEXT WEATHER MAKER WILL BE ORGANIZING ACROSS THE CENTRAL PLAINS
FRIDAY NIGHT THROUGH SATURDAY...BEFORE SHIFTING TOWARD MN AND IA
SATURDAY NIGHT. THE SFC LOW WILL SIT AND SPIN BEFORE FINALLY EXITING
NORTHEASTWARD ACROSS W LAKE SUPERIOR AROUND 06Z MONDAY AND SOUTHERN
ONTARIO DURING THE DAY MONDAY...AS THE 500MB TROUGH/LOW DIVES ACROSS
THE NORTHERN PLAINS SUNDAY INTO SUNDAY NIGHT. ADDED TS CHANCES
SATURDAY THROUGH MONDAY MORNING...BEFORE THE END TO THE BULK OF
MOISTURE. AT THIS POINT IT LOOKS LIKE THERE WILL BE A GOOD CHANCE OF
SOAKING RAIN OVER THE FAR W PORTIONS OF UPPER MI FRIDAY NIGHT
THROUGH SATURDAY...WITH ANOTHER ROUND POSSIBLE LATER SUNDAY INTO
MONDAY AS THE COLD FRONT SWINGS THROUGH.
OTHER THAN SUNDAY TIMING DIFFERENCES BETWEEN THE 12Z RUNS OF THE GFS
AND ECMWF...THE FCST MODELS ARE IN NORMAL TO SLIGHTLY ABOVE NORMAL
AGREEMENT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 137 PM EDT MON MAY 13 2013
EXPECT VFR CONDITIONS AT ALL THREE SITES THROUGH THE PERIOD. CLOUDS
WILL BE ON THE INCREASE WITH LOWERING CEILINGS THROUGH THIS
AFTERNOON AND EVENING...AS AN UPPER LEVEL DISTURBANCE PASSES
THROUGH. AS THIS DISTURBANCE MOVES THROUGH...THERE IS THE POTENTIAL
FOR SOME SHOWERS BUT THEY SHOULDN/T AFFECT VISIBILITIES DUE TO THE
5KFT PLUS BASES AND GENERALLY LIGHT RAIN. HAVE THE GREATEST
CONFIDENCE OF THEM OCCURRING NEAR KSAW...BUT MENTIONED THEM FOR ALL
THREE SITES. THIS DISTURBANCE WILL SHIFT EAST OVERNIGHT AND THERE
ARE SOME HINTS AT PATCHY FOG OR LOW CLOUDS OVER THE WEST. BUT WITH
LIMITED RAINFALL EXPECTED...EXISTING DRY LOW LEVELS AND
STRONG WINDS ALOFT...WILL LEAVE OUT MENTION. TOMORROW MORNING SHOULD
BE QUIET...WITH ANOTHER INCREASE IN MID-HIGH CLOUDS AHEAD OF THE
NEXT DISTURBANCE. FINALLY...WILL KEEP MENTION OF LLWS IN FOR
KIWD/KSAW THIS EVENING AND EARLY OVERNIGHT AS THE DISTURBANCE MOVES
THROUGH.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 351 PM EDT MON MAY 13 2013
HIGH PRESSURE WILL DEPART THE AREA THIS EVENING. THIS WILL LEAD TO
INCREASING SOUTHERLY FLOW TONIGHT INTO TUESDAY AHEAD OF A LOW
PRESSURE SYSTEM MOVING EAST THROUGH SOUTHERN CANADA. AT THIS
POINT...THE INCREASING WARM AIR ABOVE THE SURFACE SHOULD LIMIT GUST
TO 20KTS IN MOST LOCATIONS FOR OVERNIGHT TONIGHT AND TUESDAY.
DISPITE A COUPLE OF SIGNIFICANT SYSTEMS PUSHING THROUGH THE AREA
TUESDAY-TUESDAY NIGHT...AND AGAIN THIS WEEKEND...WINDS ARE CURRENTLY
ANTICIPATED TO REMAIN BELOW 30KTS. IT IS THAT TIME OF YEAR
AGAIN...THERE WILL BE A ROUND OF THUNDERSTORMS POSSIBLE TUESDAY
AFTERNOON OVER WESTERN LAKE SUPERIOR...PUSHING EASTWARD OVERNIGHT
AND ENDING EARLY WEDNESDAY. ANOTHER ROUND OF THUNDERSTORMS WILL BE
POSSIBLE WEST ON SATURDAY/SATURDAY NIGHT...AND ACROSS ALL OF LAKE
SUPERIOR SUNDAY THROUGH MONDAY MORNING.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...KF
AVIATION...SRF
MARINE...SRF/KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
136 AM EDT MON MAY 13 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 404 PM EDT SUN MAY 12 2013
WV IMAGERY AND RUC ANALYSIS INDICATED AN AMPLIFIED PATTERN WITH A
RIDGE OVER WRN NOAM AND A TROUGH OVER THE EAST. THE MID LEVEL LOW
CENTER WAS SLOWLY MOVING OFF TO THE EAST OF CYSB INTO QUEBEC. AT THE
SFC...THE PRES GRADIENT ACROSS LAKE SUPERIOR WAS GRADUALLY WEAKENING
AS THE 998 MB LOW ALSO MOVES INTO QUEBEC AND A RIDGE RIDGE FROM NW
ONTARIO THROUGH WRN MN BUILDS INTO THE UPPER MS VALLEY. RADAR
INDICATED THAT THE LINGERING FLURRIES BTWN MQT-ESC-ISQ WERE
DIMINISHING AS DRIER AIR MOVES IN .
TONIGHT...EXPECT THAT THE REST OF THE LOWER CLOUDS WILL DISSIPATE
DURING THE LATE AFTERNOON AND EARLY EVENING...PER SATELLITE
TRENDS...BUT MAY LINGER A BIT LONGER THAN WHAT SHORT TERM MODEL LOW
LEVEL RH GUIDANCE SUGGESTS. WITH GOOD RADIATIONAL COOLING CONDITIONS
BY LATE THIS EVENING WEST AND OVER NIGHT EAST AND PWAT VALUES BELOW
0.25 INCH...MIN TEMPS SHOULD FALL TOWARD THE LOWER END OF GUIDANCE
AND NEAR RECORD VALUES. THE RECORD FOR THE NWS OFFICE ON 5/12 IS 24
AND ON 5/13 IS 25. READINGS INTO THE UPPER TEENS INTERIOR WEST TO THE
MID 20S EAST ARE EXPECTED WHILE TEMPS AROUND 30 PREVAIL NEAR THE
GREAT LAKES.
MONDAY...AS THE MID/UPPER LEVEL RIDGE OVER THE PLAINS BUILDS TO THE
EAST...A BROAD WAA PATTERN WILL DEVELOP OVER THE UPPER MS VALLEY AND
WRN GREAT LAKES. 295-305K ISENTRPOPIC ASCENT AHEAD OF A TROUGH
MOVING TOWARD MN WILL BRING INCREASING HIGH CLOUDS ACROSS UPPER MI
DURING THE AFTERNOON. THE INITIAL DRY LOW LEVELS AHEAD OF THE BAND
OF MOISTURE/ASCENT WILL LIMIT EASTWARD PROGRESSION OF THE LIGHT PCPN
BAND TO THE FAR WEST DURING THE LATE AFTERNOON WHERE ONLY SLIGHT
CHANCE POPS WERE INCLUDED.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 157 PM EDT SUN MAY 12 2013
SLY FLOW WILL DOMINATE BETWEEN A SFC RIDGE OVER THE ERN CWA AND A
TROUGH OVER THE MN/ND/SD BORDERS AT 00Z TUE. WAA AND ASSOCIATED THIN
BAND OF LIGHT SHOWERS WILL BE OVER THE WRN CWA. COVERAGE OF THESE
RAIN SHOWERS WILL BE LIMITED BY LIMITED MOISTURE...SO WILL KEEP POPS
ON THE LOWER SIDE SIMILAR TO LAST FORECAST. THE PRECIP MOVES TO THE
FAR ERN CWA BY 12Z TUE.
BY 00Z WED...A SHORTWAVE TROUGH AND SFC LOW WILL MOVE TO SRN
MANITOBA...BRINGING A WARM FRONT INTO THE CWA AND A COLD FRONT TO
CENTRAL MN. BY THIS TIME...850MB TEMPS WILL HAVE INCREASED TO AROUND
16C OVER THE WRN CWA AND 9C OVER THE ERN CWA /14C AND 11C WARMER
THAN 24 HOURS BEFORE...RESPECTIVELY/. THE WARM FRONT WILL MOVE
THROUGH THE CWA FOLLOWED SHORTLY AFTER BY THE COLD FRONT WED NIGHT
INTO EARLY WED. WHILE THUNDERSTORMS APPEAR LIKELY GIVEN INSTABILITY
AND STEEP LAPSE RATES...THERE IS SOME UNCERTAINTY WITH CONVECTIVE
STRENGTH. MODEL FORECAST SOUNDINGS INDICATE POTENTIAL FOR OVER
1000J/KG OF ELEVATED CAPE...BUT MODELS SHORT THE DRY SLOT ROTATING
THROUGH AROUND THE SAME TIME AS THE SHORTWAVE...BRINGING AN ELEVATED
MIXED LAYER THAT LEADS TO 100-200J/KG OF CIN. WHETHER THE COLD FRONT
CAN LIFT PARCELS THROUGH THE DRY LAYER AND THE EXACT TIMING OF THE
DRYER AIR REALLY LOWERS CONFIDENCE IN STRONGER THUNDERSTORMS.
ALSO...MODELS NOW AGREE FAIRLY WELL ON TIMING OF THE SYSTEM...BUT
VARY MORE SIGNIFICANTLY ON HOW FAR N OR S TO BRING THE
SYSTEM...WHICH IMPACTS POTENTIAL FORCING FOR ASCENT AND THE STRENGTH
OF THE LOW LEVEL JET. PRECIP DOES APPEAR LIKELY ENOUGH WED NIGHT TO
GO WITH LIKELY POPS /AT LEAST OVER THE NRN AND ERN CWA/...AND
THUNDER ALSO SEEMS LIKE A GOOD BET IN MOST LOCATIONS THAT RECEIVE
RAIN. DEFINITELY NOT SURE ON SEVERE POTENTIAL YET...BUT THERE IS
SOME INDICATION THAT ISOLATED SEVERE WX MAY BE POSSIBLE.
EVEN THOUGH 850MB TEMPS ARE COOLER DURING THE DAY WED THAN
TUE...GOOD MIXING AND SUNSHINE BEHIND THE COLD FRONT WILL LEAD TO
WARMER HIGH TEMPS AND LOWER RH VALUES...COMBINED WITH BREEZY WLY
WINDS. EXPECT HIGHS IN THE 70S INLAND...WITH AROUND 60 EXPECTED
CLOSER TO LAKE SUPERIOR. WILL CONTINUE TREND FROM PREVIOUS SHIFT OF
LOWERING DEW PTS LOWER GIVEN GOOD MIXING AND DRY AIRMASS BEHIND THE
FRONT...LEADING TO MIN RH VALUES IN THE 25-30 PERCENT /OR LOWER/
RANGE OVER INTERIOR CENTRAL AND WEST UPPER MI. INCREASED WINDS ON WED
TO GUSTS TO 30KTS OVER THE WRN CWA /COULD BE HIGHER IF NAM
VERIFIES...BUT IT IS ON THE STRONGER SIDE/. IT IS WORTH NOTING THAT
THE WARMEST TEMPS...LOWEST RH AND HIGHEST WINDS ARE EXPECTED OVER
THE INTERIOR WRN CWA...WHERE THE CHANCES FOR SIGNIFICANT PRECIP TUE
NIGHT ARE THE LOWEST. WILL NEED TO CONTINUE TO MONITOR CONDITIONS
FOR WED...BUT MAY SEE CRITICAL FIRE WEATHER CONDITIONS OVER AT LEAST
PORTIONS OF UPPER MI.
HIGH TEMPS WILL BE A A DEGREE OR TWO COOLER THU...BUT STILL EXPECT
70S INLAND AND AROUND 60 NEAR LAKE SUPERIOR. MIN RH VALUES LOOK TO
BE SIMILAR TO WED ON THE LOW END OF THE COMFORT SCALE FOR FIRE
WX...BUT WINDS WILL BE MUCH LIGHTER AS BROAD HIGH PRESSURE SETTLES
OVER THE REGION.
FOR FRI THROUGH SUN...JUST LOADED A CONSENSUS OF MODEL GUIDANCE DUE
TO INCREASED UNCERTAINTY AND GREATER FOCUS ON FORECAST TUE-THU.
OVERALL...EXPECT TEMPS AROUND SEASONAL NORMALS /A REGULAR SEASONAL
NORMAL...NOT THIS SEASONS NORMAL/ WITH HIGHS IN THE 60S TO LOW 70S.
PRECIP WILL BE POSSIBLE AS FRONTAL ZONES WILL BE NEARBY...BUT
GETTING TOO SPECIFIC AT THIS POINT WOULD BE FUTILE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 135 AM EDT MON MAY 13 2013
VFR CONDITIONS WILL PREVAIL AT ALL TAF SITES THROUGH THE PERIOD.
APPROACH OF NEXT WEATHER DISTURBANCE BY LATE THIS AFTERNOON WILL
BRING A LOW TO MID DECK OF CLOUDS...BUT SHOULD STILL STAY VFR.
THERE WILL BE CHANCES FOR RAIN IN THE EVENING...BUT CHANCE IS STILL
LOW ENOUGH NOT TO PUT INTO TAFS QUITE YET. &&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 404 PM EDT SUN MAY 12 2013
GALES WILL SUBSIDE BY EARLY EVENING AND WINDS OVER THE EAST WILL
DROP BELOW 20 KNOTS OVERNIGHT AS A RIDGE BUILDS INTO THE REGION
WINDS WILL INCREASE OUT OF THE S/SE TO 25 KTS MON NIGHT THROUGH TUE
NIGHT AHEAD OF A LOW PRESSURE SYSTEM MOVING NORTH OF LAKE SUPERIOR
ON WED. A WARM FRONT SLIDING ACROSS LAKE SUPERIOR TUESDAY NIGHT AHEAD
OF THE LOW MAY RESULT IN A FEW STRONGER THUNDERSTORMS. LIGHTNING AND
HEAVY DOWNPOURS WOULD BE THE PRIMARY HAZARDS. EXPECT WINDS TO SHIFT
WESTERLY ON WEDNESDAY BEHIND THE COLD FRONT. POSSIBLE THAT GUSTS
COULD REACH 30 KTS. LIGHTER WINDS ARE EXPECTED AGAIN LATE IN THE WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS DULUTH MN
922 PM CDT TUE MAY 14 2013
.UPDATE...HAS BEEN A BUSY EVENING PROVIDING WEATHER SUPPORT FOR
THE WILDFIRE OVER THE EASTERN DOUGLAS COUNTY/WESTERN BAYFIELD
COUNTY LINE AREA. THE PRECIPITATION MAINLY STAYED NORTH OF THE CWA
THIS AFTERNOON AND EVENING. THE BIG STORY IS DEFINITELY THE
WILDFIRE...WHICH DEVELOPED RAPIDLY AND RESULTED IN ONGOING
EVACUATIONS. TEMPERATURES APPROACHED 90 DEGREES IN THAT AREA THIS
AFTERNOON WITH GUSTY SOUTHWEST WINDS. THE BIG CONCERN WAS THE
PASSAGE OF A COLD FRONT...WHICH SHIFTED WINDS TO THE WEST DURING
THE EVENING. FORTUNATELY THE INTENSE WINDS THAT MOVED ACROSS MUCH
OF MN DID NOT MAKE IT TOO FAR INTO WI BEFORE WINDS STARTED TO
DIMINISH THIS EVENING. THE DLHWRF...RAP AND HRRR ALL HAD A REALLY
GOOD HANDLE ON THE WINDS AND WE DETAILED THAT IN A COUPLE UPDATES
TO THE FIRE WEATHER SPOT FORECAST.
&&
.PREV DISCUSSION... /ISSUED 700 PM CDT TUE MAY 14 2013/
AVIATION.../00Z TAF ISSUANCE/
A COLD FRONT WILL MOVE ACROSS THE NORTHLAND TONIGHT...RESULTING IN
VFR CONDITIONS BUT GUSTY WESTERLY WINDS.
PREV DISCUSSION... /ISSUED 341 PM CDT TUE MAY 14 2013/
SHORT TERM...SFC FRONT LOCATED JUST WEST OF CWA AS OF MID
AFTERNOON. INITIAL CONVECTIVE AREA HAS SHIFTED WELL EAST OF CWA
WITH STRONG WARM ADVECTION OCCURRING. MAX TEMPS HAVE REACHED MID
TO UPPER 80S ACROSS SWRN AND SRN MN CWA... AND LOW 80S INTERIOR
WISC ZONES. MID 40S ARE COMMON ALONG LAKE SUPERIOR AS ONSHORE FLOW
PREVAILS DUE TO LARGE THERMAL GRADIENT. AHEAD OF FRONT A RELATIVE
MOIST AXIS EXISTS FROM KOOCH COUNTY SOUTH TO CASS COUNTY WITH
DEWPOINTS MID 40S TO 50. CONVECTION TRYING TO ORGANIZE ACROSS NRN
KOOCH INTO ONTARIO AS AN AREA OF MUCAPE NEAR 500 J/KG HAS
DEVELOPED. HAVE KEPT LOW POPS ALONG BORDERLAND INTO ARROWHEAD
UNTIL FROPA LATE TODAY OR THIS EVENING. REMOVED POPS OVER WISC AS
CONVECTIVE INHIBITION APPEARS TO BE TOO STRONG.
TONIGHT...FRONTAL SYSTEM WILL USHER IN GUSTY WEST AND NORTHWEST
WINDS THIS EVENING. WINDS COULD BE STRONG OVER NRN HALF OF MN CWA
THROUGH MID EVENING. MIXING POTENTIAL SHOULD CONTINUE OVER MOST OF
THE CWA THROUGH THE NIGHT SO MAY HAVE TO WATCH OVERNIGHT MINS FOR
COLD BIAS.
TOMORROW...A PLEASANT DAY AHEAD IN TERMS OF SUNSHINE AND MILD
READINGS. GUSTY WINDS WILL DEVELOP BY MID MORNING AS MOMENTUM
TRANSFER OCCURS IN A LOW SHEAR BDRY LYR. FIRE DANGER INCREASING
OVER ARROWHEAD AND WISC AS LOW RH/WARM AIR COMBINE TO INCREASE
THREAT. LIMITING FACTOR WOULD APPEAR TO BE SUFFICIENT WINDS.
LONG TERM [WEDNESDAY NIGHT - MONDAY]...
THE BEGINNING OF THE PERIOD LOOKS DRY AS HIGH PRESSURE OVER ONTARIO
AND THE GREAT LAKES HELP PROMOTE DRY AND RELATIVELY CLEAR WEATHER
FOR WEDNESDAY NIGHT AND THURSDAY. THERE IS A REMOTE POSSIBILITY OF
PCPN WEDNESDAY NIGHT DUE TO A POTENTIAL STALLED TRAILING SECONDARY
COLD FRONT IN THE WAKE OF THE LOW PRESSURE SYSTEM MOVING THROUGH
TODAY. HOWEVER...SINCE THIS SEEMS SO REMOTE...KEPT THE WEDNESDAY
NIGHT FORECAST DRY.
IT STILL LOOKS LIKE THURSDAY NIGHT AND THROUGH THE WEEKEND WILL BE
RATHER ACTIVE WITH PERIODS OF SHOWERS AND THUNDERSTORMS AS A
MID/UPPER LEVEL RIDGE MOVES INTO AND THROUGH THE PLAINS AND UPPER
MIDWEST. THE MOST ACTIVE PERIOD MAY BE LATE IN THE WEEKEND AND EARLY
NEXT WEEK WHEN A STRONG LOW PRESSURE SYSTEM POSSIBLY MOVES THROUGH
THE UPPER MIDWEST. DETAILS ARE HARD TO DETERMINE DUE TO SIGNIFICANT
DIFFERENCES BETWEEN EACH MODEL...AND FROM RUN TO RUN...BUT THE
OVERALL THEME OF A PROLONGED WET PERIOD LOOKS SIMILAR. AN OPEN GULF
OF MEXICO WILL ALLOW PLENTY OF MOISTURE TO WORK ITS WAY NORTH TO THE
UPPER MIDWEST. THE NORTHLAND COULD RACK UP SIGNIFICANT AMOUNTS OF
RAINFALL OVER THE SPAN OF SEVERAL DAYS...POSSIBLY MORE THAN A FEW
INCHES IN AREAS. THIS COULD RESULT IN RISES ALONG AREA STREAMS AND
RIVERS.
TEMPERATURES WILL LIKELY BE ABOVE NORMAL FOR THURSDAY AND
FRIDAY...AND THEN TREND TOWARDS NORMAL INTO EARLY NEXT WEEK.
AVIATION.../18Z TAF ISSUANCE/
MOSTLY CLEAR SKIES AND VFR CONDITIONS ARE RETURNING TO NE
MINNESOTA AND NW WISCONSIN EARLY THIS AFTERNOON IN THE WAKE OF
MORNING RAIN SHOWERS THAT MOVED THROUGH THE REGION. THE WINDS WILL
INCREASE THIS AFTERNOON AS A COLD FRONT IN THE FAR NW MINNESOTA
AND THE EASTERN DAKOTAS APPROACHES THE NORTHLAND. THERE IS A SMALL
CHANCE OF SHOWERS AND STORMS WITH THE PASSAGE OF THE COLD FRONT
LATER THIS AFTERNOON. THE CANADIAN BORDER AND KINL AREA HAVE THE
GREATEST CHANCE OF SEEING STORMS...SO I KEPT THE TEMPO GROUP AT
KINL FOR -TSRA. I THINK IT IS VERY UNLIKELY THAT
KBRD/KHYR/KDLH/KHIB WILL SEE ANY STORMS...BUT WE WILL NEED TO KEEP
AN EYE ON STORM DEVELOPMENT ALONG THE COLD FRONT. THERE MAY A
BRIEF PERIOD OF STRONG W WINDS OF 15 TO 20 KNOTS WITH GUSTS UP TO
30 KNOTS AT KBRD/KINL/KHIB LATE THIS AFTERNOON AND EARLY THIS
EVENING IN THE WAKE OF THE COLD FRONT.
&&
.POINT TEMPS/POPS...
DLH 47 72 46 68 / 10 0 0 0
INL 44 69 40 70 / 10 0 10 0
BRD 48 74 47 76 / 10 0 0 10
HYR 48 74 44 75 / 10 0 0 10
ASX 47 72 44 66 / 10 0 0 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...DAP
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
915 PM CDT TUE MAY 14 2013
.SYNOPSIS...
ISSUED AT 307 PM CDT TUE MAY 14 2013
RIDGING ALOFT ACROSS THE WESTERN CONUS...HAS BEGUN TO
BREAK DOWN THIS MORNING AS A DECENT JET STREAK AND DISTURBANCE
TRAVERSES THE NORTHERN ROCKIES AND NRN HIGH PLAINS. DECENT H5 HT
FALLS WERE NOTED THIS MORNING...WITH 70 METER FALLS AT GREAT FALLS
MT AND 100 METER FALLS AT GLASGOW MT. FURTHER EAST...A TROUGH OF LOW
PRESSURE ALOFT EXTENDED FROM QUEBEC SWD INTO NEW ENGLAND...WHILE A
CLOSED LOW WAS PRESENT OVER NWRN MEXICO. AT THE SURFACE...A COLD
FRONT WAS ANCHORED ACROSS NORTHERN NEBRASKA...AND THE SRN
PROGRESSION OF THIS FEATURE HAS SLOWED OVER THE PAST COUPLE OF HOURS
AND AS OF 2 PM CDT...WAS PRESENT FROM KLBF TO KODX. AS OF 2 PM
CDT...TEMPERATURES RANGED FROM...85 AT VALENTINE...TO 96 AT IMPERIAL.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 307 PM CDT TUE MAY 14 2013
ABNORMALLY WARM AND DRY CONDITIONS TODAY HAVE ALLOWED FOR WIDESPREAD
RFW CRITERIA...THUS THE RED FLAG WARNING WILL REMAIN IN EFFECT
THROUGH 02Z THIS EVENING FOR NE FIRE ZONES 206...208 & 209.
OTHERWISE THE FOCUS OF THE SHORT TERM PERIODS SHIFTS TO STORM
CHANCES ACROSS OUR SOUTHERN AND SOUTHWESTERN ZONES THIS EVENING AND
TONIGHT. A COLD FRONT HAS RAPIDLY DROPPED SOUTH ACROSS MUCH OF THE
FORECAST AREA...SAVE FOR THE FAR SOUTHEASTERN PORTIONS OF THE CWA.
THE COLD FRONT...AND ADDITIONALLY A PRE-FRONTAL TROUGH...ARE
CURRENTLY ACTING AS A FOCUSING MECHANISM...WITH AGITATED CU NOTED ON
THE REGIONAL VISIBLE SATELLITE STRETCHING FROM THE LEE OF THE PALMER
DIVIDE NORTHEAST THROUGH FAR NORTHWEST KANSAS INTO SOUTH CENTRAL
NEBRASKA. THE INITIAL CELLS HAVE THUS FAR STRUGGLED ACROSS FAR
SOUTHWEST NEBRASKA EARLY THIS AFTERNOON...OWING MAINLY TO THE
ABNORMALLY DRY LOWER LEVELS. HOWEVER MODEL GUIDANCE DOES INDICATE
THE POTENTIAL THAT A STORM OR TWO MAY BE ABLE TO MAINTAIN ITSELF.
PROXIMITY SOUNDINGS ACROSS SOUTHWEST NEBRASKA MAINTAIN AN INVERTED V
PROFILE WELL INTO THE OVERNIGHT...THUS VERY LITTLE RAIN WOULD BE
ANTICIPATED UNDER ANY STORM THAT CAN DEVELOP. GUSTY ERRATIC WINDS
WOULD BE A CONCERN HOWEVER. ALSO CANNOT ENTIRELY RULE OUT A NON
SUPERCELL SPIN UP THIS AFTERNOON/EARLY EVENING AS 0-1KM LAPSE RATES
ARE VERY STEEP AND CORRESPOND WELL WITH WEAK DEEP LAYER SHEAR AND
SUFFICIENT INSTABILITY. SPC NON-SUPERCELL TORNADO PARAMETER HAS
CONSISTENTLY INCREASED THROUGHOUT THE AFTERNOON...WITH VALUES OF 5
NOW SHOWN ACROSS FRONTIER COUNTY NORTHEAST INTO FAR SOUTHEASTERN
CUSTER COUNTY. INTO THE OVERNIGHT...NEAR TERM SOLUTIONS HINT AT
ACTIVITY BUILDING NORTHEAST FROM THE HIGHER TERRAIN OF EASTERN
COLORADO/WYOMING. HAVE GENERALLY DOWNPLAYED THIS POTENTIAL WITH THE
WEAK STEERING CURRENTS AND DRY LOW LEVELS...BUT WILL LEAVE SLIGHT
CHANCES IN ACROSS OUR FAR WEST FOR NOW.
WITHIN A POST FRONTAL REGIME...TEMPERATURES ON WEDNESDAY WILL BE
NOTICEABLY COOLER...HIGHS IN THE UPPER 70S TO LOWER 80S SHOULD
PREVAIL.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 307 PM CDT TUE MAY 14 2013
WEDNESDAY NIGHT THROUGH FRIDAY...THE MAIN FORECASTING CHALLENGES
IN THE MID RANGE ARE PRECIPITATION CHANCES THURSDAY AND FRIDAY. AS
WAS THE CASE YESTERDAY...BOTH THE NAM AND GFS INITIALIZED WELL
WITH A DECENT MID LEVEL SHORTWAVE NOTED OFF THE COAST OF CENTRAL
CALIFORNIA. BOTH MODELS TRACK THIS FEATURE EAST ACROSS THE CENTRAL
ROCKIES THROUGH 48 HOURS. AS WAS THE CASE YESTERDAY...THE NAM IS
FASTER WITH THIS FEATURE THROUGH WEDNESDAY...ABOUT 12 HOURS
FASTER...WHICH PLACES THIS FEATURE IN EASTERN COLORADO BY 00Z
THURSDAY (WEDNESDAY EVENING). THE GFS HAS THIS FEATURE IN EASTERN
COLORADO BY 12Z THURSDAY. SINCE THE GFS HAS REMAINED CONSISTENT
WITH THE TIMING OF THIS FEATURE...WILL LEAN TOWARD A DRY FCST WEDS
NIGHT AND START POPS IN THE WEST THURSDAY MORNING...AND CONTINUE
THEM EAST INTO THE REMAINDER OF THE FORECAST AREA THROUGH THURSDAY
EVENING. THE UPPER LEVEL PATTERN WILL AMPLIFY FURTHER THURSDAY
NIGHT INTO FRIDAY. THIS WILL STRENGTHEN A LEE SIDE TROUGH OFF TO
THE WEST OF THE FORECAST AREA...LEADING TO INCREASING SRLY WINDS
AND AN INFLUX OF LOW LEVEL MOISTURE. DECIDED TO INCREASE CLOUD
COVER IN THE WESTERN CWA FRIDAY MORNING AS THE INFLUX OF MOISTURE
MAY LEAD TO THE DEVELOPMENT OF LOW CLOUDINESS. THIS IS SUPPORTED
BY THE LATEST NAM AND MET AND MAV GUIDANCE. WITH SRLY WINDS
EXPECTED ACROSS THE CWA FRIDAY AND BACKED WINDS WELL NORTH OF THE
FORECAST AREA...LOW LEVEL CLOUDS WILL BURN OFF BY LATE MORNING.
THE FORECAST THEN SHIFTS TO THE THREAT FOR THUNDERSTORMS IN THE
WEST FRIDAY AFTERNOON AS A LEAD DISTURBANCE CROSSES THE CENTRAL
ROCKIES...LIFTING INTO THE WESTERN DAKOTAS. A WELL PRONOUNCED DRY
LINE WILL EXTEND FROM THE EASTERN PANHANDLE INTO EASTERN COLORADO
FRIDAY AFTERNOON. THE CAP WILL BE WEAKEST IN NEBRASKA AND SOUTH
DAKOTA...WITH IT REMAINING FAIRLY STRONG IN WESTERN KANSAS. WITH
THE H5 WINDS ORIENTED SSW TO NNE...THE BULK OF THE ACTIVITY IS
EXPECTED TO REMAIN WEST OF NORTH PLATTE THROUGH FRIDAY AFTERNOON.
DEEP LAYER SHEAR FRIDAY AFTERNOON WILL BE ON THE ORDER OF 25 TO 35
KTS ACROSS THE PANHANDLE AND WESTERN AREAS...SO MAINLY STRONG
STORMS ARE EXPECTED WITH THE THREAT FOR SEVERE STORMS RELATIVELY
LOW.
FRIDAY NIGHT THROUGH TUESDAY...THE BEFOREMENTIONED TROUGH OF LOW
PRESSURE WILL APPROACH THE CENTRAL PLAINS SATURDAY AND SATURDAY
NIGHT. SHOWERS AND THUNDERSTORMS WILL DEVELOP SATURDAY AFTERNOON AND
EVENING...AND TRAVERSE EAST INTO CENTRAL AND EASTERN NEBRASKA
SATURDAY NIGHT. SUFFICIENT SHEAR EXISTS...ALONG WITH PLENTY OF
MOISTURE...FOR SEVERE THUNDERSTORMS SATURDAY AFTERNOON AND SATURDAY
NIGHT. ATTM...FAR EASTERN PORTIONS OF THE FORECAST AREA ARE
OUTLOOKED FOR SEVERE WEATHER SATURDAY. THINKING HERE IS THAT THE
SEVERE THREAT WILL BE FURTHER WEST...ENCOMPASSING AT LEAST THE
CENTRAL...AND PORTIONS OF THE WESTERN CWA SATURDAY AND SATURDAY
NIGHT. THIS IS DUE TO INCREASED AMPLIFICATION OF THE H5 TROUGH AND
LOW LEVEL MOISTURE BEING PRESENT ACROSS MOST OF THE FORECAST
AREA...THE EXCEPTION BEING THE EASTERN PANHANDLE. BEYOND
SATURDAY...NO MAJOR CHANGES PLANNED TO THE EXTENDED ATTM.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 608 PM CDT TUE MAY 14 2013
VFR/MVFR IS EXPECTED OVERNIGHT...VFR IS EXPECTED WEDNESDAY. THE
DEVELOPING CLUSTER OF SHOWERS AND THUNDERSTORMS WEST OF KAIA
THROUGH KDGW SHOULD MOVE EAST THIS EVENING AND DISSIPATE ACROSS
WRN NEB. THE HRRR MODEL SHOWS THE ACTIVITY BECOMING MORE NUMEROUS
WITH A DAMAGING WIND THREAT WHILE THE RAP13 MODEL SHOWS THE
ACTIVITY FALLING APART BEFORE REACHING WRN NEB. GIVEN THE ONGOING
MOISTURE ADVECTION...THE HRRR IS FAVORED. STORM ACTIVITY COULD
REMAIN STRONG THROUGH 05Z AND WEAKEN AND DISSIPATE BY AROUND 08Z-
10Z. VFR IS EXPECTED THEREAFTER.
&&
.FIRE WEATHER...
ISSUED AT 913 PM CDT TUE MAY 14 2013
RELATIVE HUMIDITY AND WIND CONDITIONS HAVE IMPROVED THIS EVENING
AS TEMPERATURES DROP AND WINDS CONTINUE TO DIMINISH. BECAUSE OF
THIS...THE RED FLAG WARNING WHICH WAS IN PLACE FOR FIRE ZONES
206...208...AND 209 HAS BEEN ALLOWED TO EXPIRE AT 9 PM.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CLB
SHORT TERM...JACOBS
LONG TERM...CLB
AVIATION...CDC
FIRE WEATHER...BROOKS
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
613 PM CDT TUE MAY 14 2013
.SYNOPSIS...
ISSUED AT 307 PM CDT TUE MAY 14 2013
RIDGING ALOFT ACROSS THE WESTERN CONUS...HAS BEGUN TO
BREAK DOWN THIS MORNING AS A DECENT JET STREAK AND DISTURBANCE
TRAVERSES THE NORTHERN ROCKIES AND NRN HIGH PLAINS. DECENT H5 HT
FALLS WERE NOTED THIS MORNING...WITH 70 METER FALLS AT GREAT FALLS
MT AND 100 METER FALLS AT GLASGOW MT. FURTHER EAST...A TROUGH OF LOW
PRESSURE ALOFT EXTENDED FROM QUEBEC SWD INTO NEW ENGLAND...WHILE A
CLOSED LOW WAS PRESENT OVER NWRN MEXICO. AT THE SURFACE...A COLD
FRONT WAS ANCHORED ACROSS NORTHERN NEBRASKA...AND THE SRN
PROGRESSION OF THIS FEATURE HAS SLOWED OVER THE PAST COUPLE OF HOURS
AND AS OF 2 PM CDT...WAS PRESENT FROM KLBF TO KODX. AS OF 2 PM
CDT...TEMPERATURES RANGED FROM...85 AT VALENTINE...TO 96 AT IMPERIAL.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 307 PM CDT TUE MAY 14 2013
ABNORMALLY WARM AND DRY CONDITIONS TODAY HAVE ALLOWED FOR WIDESPREAD
RFW CRITERIA...THUS THE RED FLAG WARNING WILL REMAIN IN EFFECT
THROUGH 02Z THIS EVENING FOR NE FIRE ZONES 206...208 & 209.
OTHERWISE THE FOCUS OF THE SHORT TERM PERIODS SHIFTS TO STORM
CHANCES ACROSS OUR SOUTHERN AND SOUTHWESTERN ZONES THIS EVENING AND
TONIGHT. A COLD FRONT HAS RAPIDLY DROPPED SOUTH ACROSS MUCH OF THE
FORECAST AREA...SAVE FOR THE FAR SOUTHEASTERN PORTIONS OF THE CWA.
THE COLD FRONT...AND ADDITIONALLY A PRE-FRONTAL TROUGH...ARE
CURRENTLY ACTING AS A FOCUSING MECHANISM...WITH AGITATED CU NOTED ON
THE REGIONAL VISIBLE SATELLITE STRETCHING FROM THE LEE OF THE PALMER
DIVIDE NORTHEAST THROUGH FAR NORTHWEST KANSAS INTO SOUTH CENTRAL
NEBRASKA. THE INITIAL CELLS HAVE THUS FAR STRUGGLED ACROSS FAR
SOUTHWEST NEBRASKA EARLY THIS AFTERNOON...OWING MAINLY TO THE
ABNORMALLY DRY LOWER LEVELS. HOWEVER MODEL GUIDANCE DOES INDICATE
THE POTENTIAL THAT A STORM OR TWO MAY BE ABLE TO MAINTAIN ITSELF.
PROXIMITY SOUNDINGS ACROSS SOUTHWEST NEBRASKA MAINTAIN AN INVERTED V
PROFILE WELL INTO THE OVERNIGHT...THUS VERY LITTLE RAIN WOULD BE
ANTICIPATED UNDER ANY STORM THAT CAN DEVELOP. GUSTY ERRATIC WINDS
WOULD BE A CONCERN HOWEVER. ALSO CANNOT ENTIRELY RULE OUT A NON
SUPERCELL SPIN UP THIS AFTERNOON/EARLY EVENING AS 0-1KM LAPSE RATES
ARE VERY STEEP AND CORRESPOND WELL WITH WEAK DEEP LAYER SHEAR AND
SUFFICIENT INSTABILITY. SPC NON-SUPERCELL TORNADO PARAMETER HAS
CONSISTENTLY INCREASED THROUGHOUT THE AFTERNOON...WITH VALUES OF 5
NOW SHOWN ACROSS FRONTIER COUNTY NORTHEAST INTO FAR SOUTHEASTERN
CUSTER COUNTY. INTO THE OVERNIGHT...NEAR TERM SOLUTIONS HINT AT
ACTIVITY BUILDING NORTHEAST FROM THE HIGHER TERRAIN OF EASTERN
COLORADO/WYOMING. HAVE GENERALLY DOWNPLAYED THIS POTENTIAL WITH THE
WEAK STEERING CURRENTS AND DRY LOW LEVELS...BUT WILL LEAVE SLIGHT
CHANCES IN ACROSS OUR FAR WEST FOR NOW.
WITHIN A POST FRONTAL REGIME...TEMPERATURES ON WEDNESDAY WILL BE
NOTICEABLY COOLER...HIGHS IN THE UPPER 70S TO LOWER 80S SHOULD
PREVAIL.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 307 PM CDT TUE MAY 14 2013
WEDNESDAY NIGHT THROUGH FRIDAY...THE MAIN FORECASTING CHALLENGES
IN THE MID RANGE ARE PRECIPITATION CHANCES THURSDAY AND FRIDAY. AS
WAS THE CASE YESTERDAY...BOTH THE NAM AND GFS INITIALIZED WELL
WITH A DECENT MID LEVEL SHORTWAVE NOTED OFF THE COAST OF CENTRAL
CALIFORNIA. BOTH MODELS TRACK THIS FEATURE EAST ACROSS THE CENTRAL
ROCKIES THROUGH 48 HOURS. AS WAS THE CASE YESTERDAY...THE NAM IS
FASTER WITH THIS FEATURE THROUGH WEDNESDAY...ABOUT 12 HOURS
FASTER...WHICH PLACES THIS FEATURE IN EASTERN COLORADO BY 00Z
THURSDAY (WEDNESDAY EVENING). THE GFS HAS THIS FEATURE IN EASTERN
COLORADO BY 12Z THURSDAY. SINCE THE GFS HAS REMAINED CONSISTENT
WITH THE TIMING OF THIS FEATURE...WILL LEAN TOWARD A DRY FCST WEDS
NIGHT AND START POPS IN THE WEST THURSDAY MORNING...AND CONTINUE
THEM EAST INTO THE REMAINDER OF THE FORECAST AREA THROUGH THURSDAY
EVENING. THE UPPER LEVEL PATTERN WILL AMPLIFY FURTHER THURSDAY
NIGHT INTO FRIDAY. THIS WILL STRENGTHEN A LEE SIDE TROUGH OFF TO
THE WEST OF THE FORECAST AREA...LEADING TO INCREASING SRLY WINDS
AND AN INFLUX OF LOW LEVEL MOISTURE. DECIDED TO INCREASE CLOUD
COVER IN THE WESTERN CWA FRIDAY MORNING AS THE INFLUX OF MOISTURE
MAY LEAD TO THE DEVELOPMENT OF LOW CLOUDINESS. THIS IS SUPPORTED
BY THE LATEST NAM AND MET AND MAV GUIDANCE. WITH SRLY WINDS
EXPECTED ACROSS THE CWA FRIDAY AND BACKED WINDS WELL NORTH OF THE
FORECAST AREA...LOW LEVEL CLOUDS WILL BURN OFF BY LATE MORNING.
THE FORECAST THEN SHIFTS TO THE THREAT FOR THUNDERSTORMS IN THE
WEST FRIDAY AFTERNOON AS A LEAD DISTURBANCE CROSSES THE CENTRAL
ROCKIES...LIFTING INTO THE WESTERN DAKOTAS. A WELL PRONOUNCED DRY
LINE WILL EXTEND FROM THE EASTERN PANHANDLE INTO EASTERN COLORADO
FRIDAY AFTERNOON. THE CAP WILL BE WEAKEST IN NEBRASKA AND SOUTH
DAKOTA...WITH IT REMAINING FAIRLY STRONG IN WESTERN KANSAS. WITH
THE H5 WINDS ORIENTED SSW TO NNE...THE BULK OF THE ACTIVITY IS
EXPECTED TO REMAIN WEST OF NORTH PLATTE THROUGH FRIDAY AFTERNOON.
DEEP LAYER SHEAR FRIDAY AFTERNOON WILL BE ON THE ORDER OF 25 TO 35
KTS ACROSS THE PANHANDLE AND WESTERN AREAS...SO MAINLY STRONG
STORMS ARE EXPECTED WITH THE THREAT FOR SEVERE STORMS RELATIVELY
LOW.
FRIDAY NIGHT THROUGH TUESDAY...THE BEFOREMENTIONED TROUGH OF LOW
PRESSURE WILL APPROACH THE CENTRAL PLAINS SATURDAY AND SATURDAY
NIGHT. SHOWERS AND THUNDERSTORMS WILL DEVELOP SATURDAY AFTERNOON AND
EVENING...AND TRAVERSE EAST INTO CENTRAL AND EASTERN NEBRASKA
SATURDAY NIGHT. SUFFICIENT SHEAR EXISTS...ALONG WITH PLENTY OF
MOISTURE...FOR SEVERE THUNDERSTORMS SATURDAY AFTERNOON AND SATURDAY
NIGHT. ATTM...FAR EASTERN PORTIONS OF THE FORECAST AREA ARE
OUTLOOKED FOR SEVERE WEATHER SATURDAY. THINKING HERE IS THAT THE
SEVERE THREAT WILL BE FURTHER WEST...ENCOMPASSING AT LEAST THE
CENTRAL...AND PORTIONS OF THE WESTERN CWA SATURDAY AND SATURDAY
NIGHT. THIS IS DUE TO INCREASED AMPLIFICATION OF THE H5 TROUGH AND
LOW LEVEL MOISTURE BEING PRESENT ACROSS MOST OF THE FORECAST
AREA...THE EXCEPTION BEING THE EASTERN PANHANDLE. BEYOND
SATURDAY...NO MAJOR CHANGES PLANNED TO THE EXTENDED ATTM.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 608 PM CDT TUE MAY 14 2013
VFR/MVFR IS EXPECTED OVERNIGHT...VFR IS EXPECTED WEDNESDAY. THE
DEVELOPING CLUSTER OF SHOWERS AND THUNDERSTORMS WEST OF KAIA
THROUGH KDGW SHOULD MOVE EAST THIS EVENING AND DISSIPATE ACROSS
WRN NEB. THE HRRR MODEL SHOWS THE ACTIVITY BECOMING MORE NUMEROUS
WITH A DAMAGING WIND THREAT WHILE THE RAP13 MODEL SHOWS THE
ACTIVITY FALLING APART BEFORE REACHING WRN NEB. GIVEN THE ONGOING
MOISTURE ADVECTION...THE HRRR IS FAVORED. STORM ACTIVITY COULD
REMAIN STRONG THROUGH 05Z AND WEAKEN AND DISSIPATE BY AROUND 08Z-
10Z. VFR IS EXPECTED THEREAFTER.
&&
.FIRE WEATHER...
ISSUED AT 307 PM CDT TUE MAY 14 2013
A FAVORABLE FIRE WEATHER PATTERN IS EXPECTED TODAY WITH THE
BREAKDOWN OF THE UPPER LEVEL RIDGE AND THE PASSAGE OF A WEAK
FRONTAL BOUNDARY. IN ADVANCE OF THE FRONT...TEMPERATURES WILL SOAR
TO NEAR RECORD READINGS WITH CRITICALLY LOW RELATIVE HUMIDITY
VALUES ANTICIPATED. THE WEAK FRONT WILL CROSS INTO NORTHERN
NEBRASKA BY EARLY AFTERNOON...BUT SLOW WITH THE HEATING OF THE
DAY. WESTERLY WINDS WILL GENERALLY INCREASE AND SWITCH TO THE
NORTH BEHIND THE FRONT...AND MAY BECOME GUSTY. IN ADDITION...A DRY
THUNDERSTORM OR TWO WOULD HAVE THE POTENTIAL TO PRODUCE GUSTY
ERRATIC WINDS LATE THIS AFTERNOON ALONG AND NEAR THE FRONT WITH
OCCASIONAL DRY LIGHTNING. THE HAINES INDEX IS FORECAST TO BE A 6
OVER THE ENTIRE FORECAST AREA THIS AFTERNOON. A RED FLAG WARNING
IS NOW IN EFFECT THROUGH EARLY THIS EVENING FOR FIRE ZONES
206...208 & 209.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 9 PM CDT /8 PM MDT/ THIS EVENING FOR
NEZ206-208-209.
&&
$$
SYNOPSIS...CLB
SHORT TERM...JACOBS
LONG TERM...CLB
AVIATION...CDC
FIRE WEATHER...JACOBS
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1257 PM CDT MON MAY 13 2013
.SYNOPSIS...
ISSUED AT 334 AM CDT MON MAY 13 2013
AT H5 RIDGE OVER THE WESTERN CONUS CLOSED LOW OVER THE GREAT LAKES
WITH TROUGH INTO THE SOUTHEAST CONUS.
&&
.UPDATE...
ISSUED AT 1256 PM CDT MON MAY 13 2013
HAVE DONE AN UPDATE ON THE FORECAST TO ADJUST TEMPERATURES
SLIGHTLY TODAY. AT 17Z...OBSERVATIONS INDICATING A SURFACE TROUGH
ROUGHLY FROM KMCK TO K9V9 IN SD. LOCATIONS TO THE EAST ARE A BIT
COOLER WITH WINDS FROM THE SOUTH...WHILE WEST-NORTHWEST WINDS ON
THE WEST SIDE OF WERE HELPING TO ENHANCE WARMING. DESPITE CIRRUS
VEIL ACROSS THE FORECAST AREA TEMPERATURES HAVE MANAGED TO RISE
INTO THE MID AND UPPER 80S BY EARLY THIS AFTERNOON. STILL WILL SEE
TEMPERATURES IN THE 90S FOR THE FORECAST AREA THIS AFTERNOON.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 334 AM CDT MON MAY 13 2013
MODELS IN FAIR AGREEMENT. MAIN CONCERNS WILL BE RECORD HIGHS FOR
WESTERN NEBRASKA TODAY. RECORD AT LBF 91 FOR TODAY. LOT OF CIRRUS
PUSHING OVER THE RIDGE THIS MORNING. MODELS ALWAYS TEND TO UNDER
ESTIMATE THIS. 850MB TEMPERATURES AROUND 25C WHICH WOULD TRANSLATE
TO LOW 90S. RUC COMING UP WITH 95 FOR NORTH PLATTE WHERE MORE
INSOLATION EXPECTED AND WARM FRONT MAKING BIG PUSH. SOME CONVECTION
EXPECTED ON THE EASTERN PLAINS OF WYOMING AND COLORADO LATE THIS
AFTERNOON INTO EARLY EVENING...BUT WILL STRUGGLE TO MOVE INTO THE
NEBRASKA PANHANDLE AND HAVE LEFT THE FORECAST DRY FOR NOW.
TEMPERATURES TO STAY WARM WITH WAA AND SOUTHERLY FLOW TONIGHT
AHEAD OF THE TUESDAY SYSTEM DROPPING ACROSS THE NORTHERN PLAINS.
LOWS EXPECTED IN THE 50S AND 60S.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 334 AM CDT MON MAY 13 2013
A HOT DAY STILL ON TAP FOR TUESDAY...ESPECIALLY ACROSS CENTRAL INTO
SOUTHWEST NEBRASKA. SOME TIMING DIFFERENCES REMAIN WITH THE FRONTAL
PASSAGE. THE 13/00Z NAM CONTINUES TO OFFER THE FASTEST
SOLUTION...AND HAS THE FRONT MOVING INTO CENTRAL AND SOUTHWEST
NEBRASKA BY EARLY AFTERNOON. THE ECMWF AND GFS ARE SLOWER AND BRING
THE FRONT IN TOWARD EVENING. THE NAM COULD BE ONTO SOMETHING...AS IT
MAY BE FASTER AS A RESULT OF A CONVECTIVE COMPLEX ROLLING ACROSS ND
EARLY TUESDAY MORNING. THIS COULD GIVE THE FRONT AN EXTRA PUSH WITH
ANY OUTFLOW FROM THE COMPLEX. A QUICK GLANCE AT THE NEW 13/06Z NAM
SUGGESTS THE FRONT NOW A TAD SLOWER. AT THIS TIME WILL STICK CLOSE
TO THE PREVIOUS FORECAST...WHICH SIDED TOWARD A SLOWER FRONTAL
PASSAGE. WILL CONTINUE THE HOT HIGH TEMPERATURES IN THE MID AND
UPPER 90S ACROSS SOUTHWEST INTO CENTRAL NEBRASKA AHEAD OF THE FRONT.
VERY FAVORABLE CONDITIONS DEVELOP JUST AHEAD OF THE FRONT FOR THE
HOT WEATHER...WITH WEST TO SOUTHWEST SFC WINDS AND DEEP MIXING UP
THROUGH 600 MB. A FIRE WEATHER CONCERN WILL DEVELOP AHEAD OF THE
FRONT AS WELL DUE TO THE DRY CONDITIONS AND DEEP MIXING. MODELS
INDICATE WIND SPEEDS NOT QUITE TO RED FLAG CRITERIA...BUT WINDS MAY
END UP BEING STRONGER THAN THE MODELS INDICATE DUE TO SUCH DEEP
MIXING AHEAD OF THE FRONT. ALSO A CONCERN WOULD BE ANY DRY LIGHTNING
ASSOCIATED WITH THE ISOLATED HIGH BASED STORMS THAT DEVELOP ALONG
THE FRONT AS THE CAP WEAKENS DURING THE MID TO LATE AFTERNOON.
SLIGHT CHANCES FOR STORMS CONTINUE TUESDAY NIGHT AS AN AREA OF
ELEVATED INSTABILITY DEVELOPS TO THE NORTH OF THE COLD FRONT WHICH
WILL BE MOVING SOUTH INTO KS. A WEAK UPPER LEVEL DISTURBANCE WILL
MOVE EAST ACROSS THE AREA AFTER MIDNIGHT AND INTERACT WITH THE
INSTABILITY...SO THE SLIGHT CHANCES FOR PRECIP WILL BE
MAINTAINED.
SOMEWHAT COOLER AND DRIER AIR FILTERS ACROSS THE AREA WEDNESDAY AS
THE COLD FRONT STALLS ACROSS KS.
THUNDERSTORM CHANCES BEGIN TO INCREASE THURSDAY AND THURSDAY NIGHT
ACROSS WESTERN AND NORTH CENTRAL NEBRASKA. THE FRONT WHICH STALLED
WEDNESDAY ACROSS KS...WILL BEGIN TO LIFT NORTH AS A WARM FRONT INTO
WESTERN AND NORTH CENTRAL NEBRASKA THURSDAY. AS THIS OCCURS...GULF
MOISTURE WILL SURGE NORTH INTO THE AREA. THE 13/00Z GFS INDICATES
H85 DEW PTS RISING INTO THE 10 TO 12C RANGE DURING THE DAY
THURSDAY...AND INCREASING FURTHER TO 13 TO 15C THURSDAY NIGHT AS THE
LOW LEVEL JET STRENGTHENS. AT THE SAME TIME...SEVERAL SUBTLE UPPER
LEVEL WAVES EJECT NORTHEAST ACROSS THE AREA FROM DEVELOPING WESTERN
CONUS UPPER TROUGH. THIS SET UP WOULD APPEAR FAVORABLE FOR
THUNDERSTORM DEVELOPMENT ACROSS WESTERN NEBRASKA DURING THE LATE
AFTERNOON...BECOMING MORE WIDESPREAD DURING THE EVENING AS THE
SOUTHERLY LOW LEVEL JET INTENSIFIES. THE GFS OFFERS JUST THIS
SCENARIO...WITH THE ECMWF SIMILAR BUT A LITTLE FARTHER EAST WITH THE
BETTER MOISTURE ACROSS CENTRAL NEBRASKA. NAM MODEL NOT QUITE OUT FAR
ENOUGH TO HELP WITH THIS FORECAST PERIOD YET. FOR NOW WILL NOT GET
CARRIED AWAY WITH POPS...WITH THE GFS PROBABLY A TAD ON THE MOIST
SIDE BOTH WITH THE AMOUNT OF MOISTURE AND QPF.
WITH THE UPPER TROUGH REMAINING TO OUR WEST THROUGH SATURDAY
NIGHT...ACTIVE WEATHER WILL CONTINUE. STILL TOO EARLY TO PIN DOWN
EXACTLY WHERE THE BEST FOCUS FOR THUNDERSTORMS WILL BE...BUT
DEVELOPMENT IN OR JUST EAST OF OUR FORECAST AREA SEEMS LIKELY BOTH
FRIDAY AND SATURDAY.
BY SUNDAY BOTH THE 13/00Z RUNS OF THE ECMWF AND GFS DRIVE A COLD
FRONT SOUTHEAST THROUGH THE AREA. THIS WOULD PLACE THE BEST FOCUS
FOR RAIN TO OUR EAST...BUT FOR NOW WILL MAINTAIN THE CHANCES GOING
IN CASE THE FRONT SLOWS SOMEWHAT.
TEMPERATURE WISE...WITH THE INCREASED CLOUD COVER AND MOISTURE...80S
SEEM REASONABLE THURSDAY THROUGH SATURDAY...WITH COOLER UPPER 60S
AND 70S BEHIND THE FRONT SUNDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1222 AM CDT MON MAY 13 2013
VFR CONDITIONS WILL BE OBSERVED ACROSS NEBRASKA THROUGH TUESDAY
AFTERNOON. MAIN CONCERNS WILL BE WIND SHIFTS...AS WELL AS SOME
INCREASING WINDS BEHIND A COLD FRONT SET TO MOVE INTO NORTHERN
NEBRASKA TUESDAY MORNING. LOOKING FOR WINDS TO SHIFT TO THE
NORTHWEST BEHIND THE FRONT AND INCREASING WITH GUSTS TO 25 MPH.
THIS WILL IMPACT THE KVTN FORECAST IN THE MORNING...WHILE LOCATIONS
TO THE SOUTH SHOULD EXPECT TO SEE THIS SAME TREND LATER IN THE
AFTERNOON AND EVENING.
&&
.FIRE WEATHER...
ISSUED AT 334 AM CDT MON MAY 13 2013
WITH TEMPERATURES SOARING TODAY OVER WESTERN NEBRASKA AND DEWPOINTS
IN THE 30S AND 40S MINIMUM RELATIVE HUMIDITIES WILL FALL INTO THE
TEENS ACROSS WESTERN NEBRASKA...BASICALLY WHERE THEY HAVE BEEN THE
LAST SEVERAL DAYS. TUESDAY WILL BE SIMILAR AHEAD OF THE FRONT.
WINDS OVER NORTHERN NEBRASKA WILL BE 10 TO 15 MPH WITH SOME GUSTS
TO THE LOW 20S MAKING IT MARGINAL FOR HIGHLIGHTS. WILL HOLD OFF
FOR NOW. TUESDAY AHEAD OF THE FRONT ACROSS SOUTHWEST INTO CENTRAL
NEBRASKA...HIGHLIGHTS LOOK POSSIBLE...AS WINDS FROM THE SOUTHWEST
INCREASE DUE TO DEEP MIXING...AND DRY LIGHTNING IS POSSIBLE AS
WELL DUE TO THE HIGH BASED NATURE OF ANY STORM THAT WOULD HAPPEN
TO DEVELOP ALONG THE FRONT.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BROOKS
SYNOPSIS...POWER
SHORT TERM...TAYLOR
LONG TERM...POWER
AVIATION...BROOKS
FIRE WEATHER...POWER
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1223 PM CDT MON MAY 13 2013
.SYNOPSIS...
ISSUED AT 334 AM CDT MON MAY 13 2013
AT H5 RIDGE OVER THE WESTERN CONUS CLOSED LOW OVER THE GREAT LAKES
WITH TROUGH INTO THE SOUTHEAST CONUS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 334 AM CDT MON MAY 13 2013
MODELS IN FAIR AGREEMENT. MAIN CONCERNS WILL BE RECORD HIGHS FOR
WESTERN NEBRASKA TODAY. RECORD AT LBF 91 FOR TODAY. LOT OF CIRRUS
PUSHING OVER THE RIDGE THIS MORNING. MODELS ALWAYS TEND TO UNDER
ESTIMATE THIS. 850MB TEMPERATURES AROUND 25C WHICH WOULD TRANSLATE
TO LOW 90S. RUC COMING UP WITH 95 FOR NORTH PLATTE WHERE MORE
INSOLATION EXPECTED AND WARM FRONT MAKING BIG PUSH. SOME CONVECTION
EXPECTED ON THE EASTERN PLAINS OF WYOMING AND COLORADO LATE THIS
AFTERNOON INTO EARLY EVENING...BUT WILL STRUGGLE TO MOVE INTO THE
NEBRASKA PANHANDLE AND HAVE LEFT THE FORECAST DRY FOR NOW.
TEMPERATURES TO STAY WARM WITH WAA AND SOUTHERLY FLOW TONIGHT
AHEAD OF THE TUESDAY SYSTEM DROPPING ACROSS THE NORTHERN PLAINS.
LOWS EXPECTED IN THE 50S AND 60S.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 334 AM CDT MON MAY 13 2013
A HOT DAY STILL ON TAP FOR TUESDAY...ESPECIALLY ACROSS CENTRAL INTO
SOUTHWEST NEBRASKA. SOME TIMING DIFFERENCES REMAIN WITH THE FRONTAL
PASSAGE. THE 13/00Z NAM CONTINUES TO OFFER THE FASTEST
SOLUTION...AND HAS THE FRONT MOVING INTO CENTRAL AND SOUTHWEST
NEBRASKA BY EARLY AFTERNOON. THE ECMWF AND GFS ARE SLOWER AND BRING
THE FRONT IN TOWARD EVENING. THE NAM COULD BE ONTO SOMETHING...AS IT
MAY BE FASTER AS A RESULT OF A CONVECTIVE COMPLEX ROLLING ACROSS ND
EARLY TUESDAY MORNING. THIS COULD GIVE THE FRONT AN EXTRA PUSH WITH
ANY OUTFLOW FROM THE COMPLEX. A QUICK GLANCE AT THE NEW 13/06Z NAM
SUGGESTS THE FRONT NOW A TAD SLOWER. AT THIS TIME WILL STICK CLOSE
TO THE PREVIOUS FORECAST...WHICH SIDED TOWARD A SLOWER FRONTAL
PASSAGE. WILL CONTINUE THE HOT HIGH TEMPERATURES IN THE MID AND
UPPER 90S ACROSS SOUTHWEST INTO CENTRAL NEBRASKA AHEAD OF THE FRONT.
VERY FAVORABLE CONDITIONS DEVELOP JUST AHEAD OF THE FRONT FOR THE
HOT WEATHER...WITH WEST TO SOUTHWEST SFC WINDS AND DEEP MIXING UP
THROUGH 600 MB. A FIRE WEATHER CONCERN WILL DEVELOP AHEAD OF THE
FRONT AS WELL DUE TO THE DRY CONDITIONS AND DEEP MIXING. MODELS
INDICATE WIND SPEEDS NOT QUITE TO RED FLAG CRITERIA...BUT WINDS MAY
END UP BEING STRONGER THAN THE MODELS INDICATE DUE TO SUCH DEEP
MIXING AHEAD OF THE FRONT. ALSO A CONCERN WOULD BE ANY DRY LIGHTNING
ASSOCIATED WITH THE ISOLATED HIGH BASED STORMS THAT DEVELOP ALONG
THE FRONT AS THE CAP WEAKENS DURING THE MID TO LATE AFTERNOON.
SLIGHT CHANCES FOR STORMS CONTINUE TUESDAY NIGHT AS AN AREA OF
ELEVATED INSTABILITY DEVELOPS TO THE NORTH OF THE COLD FRONT WHICH
WILL BE MOVING SOUTH INTO KS. A WEAK UPPER LEVEL DISTURBANCE WILL
MOVE EAST ACROSS THE AREA AFTER MIDNIGHT AND INTERACT WITH THE
INSTABILITY...SO THE SLIGHT CHANCES FOR PRECIP WILL BE
MAINTAINED.
SOMEWHAT COOLER AND DRIER AIR FILTERS ACROSS THE AREA WEDNESDAY AS
THE COLD FRONT STALLS ACROSS KS.
THUNDERSTORM CHANCES BEGIN TO INCREASE THURSDAY AND THURSDAY NIGHT
ACROSS WESTERN AND NORTH CENTRAL NEBRASKA. THE FRONT WHICH STALLED
WEDNESDAY ACROSS KS...WILL BEGIN TO LIFT NORTH AS A WARM FRONT INTO
WESTERN AND NORTH CENTRAL NEBRASKA THURSDAY. AS THIS OCCURS...GULF
MOISTURE WILL SURGE NORTH INTO THE AREA. THE 13/00Z GFS INDICATES
H85 DEW PTS RISING INTO THE 10 TO 12C RANGE DURING THE DAY
THURSDAY...AND INCREASING FURTHER TO 13 TO 15C THURSDAY NIGHT AS THE
LOW LEVEL JET STRENGTHENS. AT THE SAME TIME...SEVERAL SUBTLE UPPER
LEVEL WAVES EJECT NORTHEAST ACROSS THE AREA FROM DEVELOPING WESTERN
CONUS UPPER TROUGH. THIS SET UP WOULD APPEAR FAVORABLE FOR
THUNDERSTORM DEVELOPMENT ACROSS WESTERN NEBRASKA DURING THE LATE
AFTERNOON...BECOMING MORE WIDESPREAD DURING THE EVENING AS THE
SOUTHERLY LOW LEVEL JET INTENSIFIES. THE GFS OFFERS JUST THIS
SCENARIO...WITH THE ECMWF SIMILAR BUT A LITTLE FARTHER EAST WITH THE
BETTER MOISTURE ACROSS CENTRAL NEBRASKA. NAM MODEL NOT QUITE OUT FAR
ENOUGH TO HELP WITH THIS FORECAST PERIOD YET. FOR NOW WILL NOT GET
CARRIED AWAY WITH POPS...WITH THE GFS PROBABLY A TAD ON THE MOIST
SIDE BOTH WITH THE AMOUNT OF MOISTURE AND QPF.
WITH THE UPPER TROUGH REMAINING TO OUR WEST THROUGH SATURDAY
NIGHT...ACTIVE WEATHER WILL CONTINUE. STILL TOO EARLY TO PIN DOWN
EXACTLY WHERE THE BEST FOCUS FOR THUNDERSTORMS WILL BE...BUT
DEVELOPMENT IN OR JUST EAST OF OUR FORECAST AREA SEEMS LIKELY BOTH
FRIDAY AND SATURDAY.
BY SUNDAY BOTH THE 13/00Z RUNS OF THE ECMWF AND GFS DRIVE A COLD
FRONT SOUTHEAST THROUGH THE AREA. THIS WOULD PLACE THE BEST FOCUS
FOR RAIN TO OUR EAST...BUT FOR NOW WILL MAINTAIN THE CHANCES GOING
IN CASE THE FRONT SLOWS SOMEWHAT.
TEMPERATURE WISE...WITH THE INCREASED CLOUD COVER AND MOISTURE...80S
SEEM REASONABLE THURSDAY THROUGH SATURDAY...WITH COOLER UPPER 60S
AND 70S BEHIND THE FRONT SUNDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1222 AM CDT MON MAY 13 2013
VFR CONDITIONS WILL BE OBSERVED ACROSS NEBRASKA THROUGH TUESDAY
AFTERNOON. MAIN CONCERNS WILL BE WIND SHIFTS...AS WELL AS SOME
INCREASING WINDS BEHIND A COLD FRONT SET TO MOVE INTO NORTHERN
NEBRASKA TUESDAY MORNING. LOOKING FOR WINDS TO SHIFT TO THE
NORTHWEST BEHIND THE FRONT AND INCREASING WITH GUSTS TO 25 MPH.
THIS WILL IMPACT THE KVTN FORECAST IN THE MORNING...WHILE LOCATIONS
TO THE SOUTH SHOULD EXPECT TO SEE THIS SAME TREND LATER IN THE
AFTERNOON AND EVENING.
&&
.FIRE WEATHER...
ISSUED AT 334 AM CDT MON MAY 13 2013
WITH TEMPERATURES SOARING TODAY OVER WESTERN NEBRASKA AND DEWPOINTS
IN THE 30S AND 40S MINIMUM RELATIVE HUMIDITIES WILL FALL INTO THE
TEENS ACROSS WESTERN NEBRASKA...BASICALLY WHERE THEY HAVE BEEN THE
LAST SEVERAL DAYS. TUESDAY WILL BE SIMILAR AHEAD OF THE FRONT.
WINDS OVER NORTHERN NEBRASKA WILL BE 10 TO 15 MPH WITH SOME GUSTS
TO THE LOW 20S MAKING IT MARGINAL FOR HIGHLIGHTS. WILL HOLD OFF
FOR NOW. TUESDAY AHEAD OF THE FRONT ACROSS SOUTHWEST INTO CENTRAL
NEBRASKA...HIGHLIGHTS LOOK POSSIBLE...AS WINDS FROM THE SOUTHWEST
INCREASE DUE TO DEEP MIXING...AND DRY LIGHTNING IS POSSIBLE AS
WELL DUE TO THE HIGH BASED NATURE OF ANY STORM THAT WOULD HAPPEN
TO DEVELOP ALONG THE FRONT.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...POWER
SHORT TERM...TAYLOR
LONG TERM...POWER
AVIATION...BROOKS
FIRE WEATHER...POWER
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
704 AM CDT MON MAY 13 2013
.SYNOPSIS...
ISSUED AT 334 AM CDT MON MAY 13 2013
AT H5 RIDGE OVER THE WESTERN CONUS CLOSED LOW OVER THE GREAT LAKES
WITH TROUGH INTO THE SOUTHEAST CONUS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 334 AM CDT MON MAY 13 2013
MODELS IN FAIR AGREEMENT. MAIN CONCERNS WILL BE RECORD HIGHS FOR
WESTERN NEBRASKA TODAY. RECORD AT LBF 91 FOR TODAY. LOT OF CIRRUS
PUSHING OVER THE RIDGE THIS MORNING. MODELS ALWAYS TEND TO UNDER
ESTIMATE THIS. 850MB TEMPERATURES AROUND 25C WHICH WOULD TRANSLATE
TO LOW 90S. RUC COMING UP WITH 95 FOR NORTH PLATTE WHERE MORE
INSOLATION EXPECTED AND WARM FRONT MAKING BIG PUSH. SOME CONVECTION
EXPECTED ON THE EASTERN PLAINS OF WYOMING AND COLORADO LATE THIS
AFTERNOON INTO EARLY EVENING...BUT WILL STRUGGLE TO MOVE INTO THE
NEBRASKA PANHANDLE AND HAVE LEFT THE FORECAST DRY FOR NOW.
TEMPERATURES TO STAY WARM WITH WAA AND SOUTHERLY FLOW TONIGHT
AHEAD OF THE TUESDAY SYSTEM DROPPING ACROSS THE NORTHERN PLAINS.
LOWS EXPECTED IN THE 50S AND 60S.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 334 AM CDT MON MAY 13 2013
A HOT DAY STILL ON TAP FOR TUESDAY...ESPECIALLY ACROSS CENTRAL INTO
SOUTHWEST NEBRASKA. SOME TIMING DIFFERENCES REMAIN WITH THE FRONTAL
PASSAGE. THE 13/00Z NAM CONTINUES TO OFFER THE FASTEST
SOLUTION...AND HAS THE FRONT MOVING INTO CENTRAL AND SOUTHWEST
NEBRASKA BY EARLY AFTERNOON. THE ECMWF AND GFS ARE SLOWER AND BRING
THE FRONT IN TOWARD EVENING. THE NAM COULD BE ONTO SOMETHING...AS IT
MAY BE FASTER AS A RESULT OF A CONVECTIVE COMPLEX ROLLING ACROSS ND
EARLY TUESDAY MORNING. THIS COULD GIVE THE FRONT AN EXTRA PUSH WITH
ANY OUTFLOW FROM THE COMPLEX. A QUICK GLANCE AT THE NEW 13/06Z NAM
SUGGESTS THE FRONT NOW A TAD SLOWER. AT THIS TIME WILL STICK CLOSE
TO THE PREVIOUS FORECAST...WHICH SIDED TOWARD A SLOWER FRONTAL
PASSAGE. WILL CONTINUE THE HOT HIGH TEMPERATURES IN THE MID AND
UPPER 90S ACROSS SOUTHWEST INTO CENTRAL NEBRASKA AHEAD OF THE FRONT.
VERY FAVORABLE CONDITIONS DEVELOP JUST AHEAD OF THE FRONT FOR THE
HOT WEATHER...WITH WEST TO SOUTHWEST SFC WINDS AND DEEP MIXING UP
THROUGH 600 MB. A FIRE WEATHER CONCERN WILL DEVELOP AHEAD OF THE
FRONT AS WELL DUE TO THE DRY CONDITIONS AND DEEP MIXING. MODELS
INDICATE WIND SPEEDS NOT QUITE TO RED FLAG CRITERIA...BUT WINDS MAY
END UP BEING STRONGER THAN THE MODELS INDICATE DUE TO SUCH DEEP
MIXING AHEAD OF THE FRONT. ALSO A CONCERN WOULD BE ANY DRY LIGHTNING
ASSOCIATED WITH THE ISOLATED HIGH BASED STORMS THAT DEVELOP ALONG
THE FRONT AS THE CAP WEAKENS DURING THE MID TO LATE AFTERNOON.
SLIGHT CHANCES FOR STORMS CONTINUE TUESDAY NIGHT AS AN AREA OF
ELEVATED INSTABILITY DEVELOPS TO THE NORTH OF THE COLD FRONT WHICH
WILL BE MOVING SOUTH INTO KS. A WEAK UPPER LEVEL DISTURBANCE WILL
MOVE EAST ACROSS THE AREA AFTER MIDNIGHT AND INTERACT WITH THE
INSTABILITY...SO THE SLIGHT CHANCES FOR PRECIP WILL BE
MAINTAINED.
SOMEWHAT COOLER AND DRIER AIR FILTERS ACROSS THE AREA WEDNESDAY AS
THE COLD FRONT STALLS ACROSS KS.
THUNDERSTORM CHANCES BEGIN TO INCREASE THURSDAY AND THURSDAY NIGHT
ACROSS WESTERN AND NORTH CENTRAL NEBRASKA. THE FRONT WHICH STALLED
WEDNESDAY ACROSS KS...WILL BEGIN TO LIFT NORTH AS A WARM FRONT INTO
WESTERN AND NORTH CENTRAL NEBRASKA THURSDAY. AS THIS OCCURS...GULF
MOISTURE WILL SURGE NORTH INTO THE AREA. THE 13/00Z GFS INDICATES
H85 DEW PTS RISING INTO THE 10 TO 12C RANGE DURING THE DAY
THURSDAY...AND INCREASING FURTHER TO 13 TO 15C THURSDAY NIGHT AS THE
LOW LEVEL JET STRENGTHENS. AT THE SAME TIME...SEVERAL SUBTLE UPPER
LEVEL WAVES EJECT NORTHEAST ACROSS THE AREA FROM DEVELOPING WESTERN
CONUS UPPER TROUGH. THIS SET UP WOULD APPEAR FAVORABLE FOR
THUNDERSTORM DEVELOPMENT ACROSS WESTERN NEBRASKA DURING THE LATE
AFTERNOON...BECOMING MORE WIDESPREAD DURING THE EVENING AS THE
SOUTHERLY LOW LEVEL JET INTENSIFIES. THE GFS OFFERS JUST THIS
SCENARIO...WITH THE ECMWF SIMILAR BUT A LITTLE FARTHER EAST WITH THE
BETTER MOISTURE ACROSS CENTRAL NEBRASKA. NAM MODEL NOT QUITE OUT FAR
ENOUGH TO HELP WITH THIS FORECAST PERIOD YET. FOR NOW WILL NOT GET
CARRIED AWAY WITH POPS...WITH THE GFS PROBABLY A TAD ON THE MOIST
SIDE BOTH WITH THE AMOUNT OF MOISTURE AND QPF.
WITH THE UPPER TROUGH REMAINING TO OUR WEST THROUGH SATURDAY
NIGHT...ACTIVE WEATHER WILL CONTINUE. STILL TOO EARLY TO PIN DOWN
EXACTLY WHERE THE BEST FOCUS FOR THUNDERSTORMS WILL BE...BUT
DEVELOPMENT IN OR JUST EAST OF OUR FORECAST AREA SEEMS LIKELY BOTH
FRIDAY AND SATURDAY.
BY SUNDAY BOTH THE 13/00Z RUNS OF THE ECMWF AND GFS DRIVE A COLD
FRONT SOUTHEAST THROUGH THE AREA. THIS WOULD PLACE THE BEST FOCUS
FOR RAIN TO OUR EAST...BUT FOR NOW WILL MAINTAIN THE CHANCES GOING
IN CASE THE FRONT SLOWS SOMEWHAT.
TEMPERATURE WISE...WITH THE INCREASED CLOUD COVER AND MOISTURE...80S
SEEM REASONABLE THURSDAY THROUGH SATURDAY...WITH COOLER UPPER 60S
AND 70S BEHIND THE FRONT SUNDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 700 AM CDT MON MAY 13 2013
VISUAL FLIGHT RULES EXPECTED OVER WESTERN NEBRASKA THROUGH TUESDAY
MORNING. WINDS TODAY WILL BECOME SOUTHWEST AND INCREASE TO 10 TO
15 MPH. HIGH DENSE CIRRUS WILL CONTINUE TO MOVE OVER WESTERN
NEBRASKA THROUGH THE DAY.
&&
.FIRE WEATHER...
ISSUED AT 334 AM CDT MON MAY 13 2013
WITH TEMPERATURES SOARING TODAY OVER WESTERN NEBRASKA AND DEWPOINTS
IN THE 30S AND 40S MINIMUM RELATIVE HUMIDITIES WILL FALL INTO THE
TEENS ACROSS WESTERN NEBRASKA...BASICALLY WHERE THEY HAVE BEEN THE
LAST SEVERAL DAYS. TUESDAY WILL BE SIMILAR AHEAD OF THE FRONT.
WINDS OVER NORTHERN NEBRASKA WILL BE 10 TO 15 MPH WITH SOME GUSTS
TO THE LOW 20S MAKING IT MARGINAL FOR HIGHLIGHTS. WILL HOLD OFF
FOR NOW. TUESDAY AHEAD OF THE FRONT ACROSS SOUTHWEST INTO CENTRAL
NEBRASKA...HIGHLIGHTS LOOK POSSIBLE...AS WINDS FROM THE SOUTHWEST
INCREASE DUE TO DEEP MIXING...AND DRY LIGHTNING IS POSSIBLE AS
WELL DUE TO THE HIGH BASED NATURE OF ANY STORM THAT WOULD HAPPEN
TO DEVELOP ALONG THE FRONT.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...POWER
SHORT TERM...TAYLOR
LONG TERM...POWER
AVIATION...POWER
FIRE WEATHER...POWER
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
350 AM CDT MON MAY 13 2013
.SYNOPSIS...
ISSUED AT 334 AM CDT MON MAY 13 2013
AT H5 RIDGE OVER THE WESTERN CONUS CLOSED LOW OVER THE GREAT LAKES
WITH TROUGH INTO THE SOUTHEAST CONUS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 334 AM CDT MON MAY 13 2013
MODELS IN FAIR AGREEMENT. MAIN CONCERNS WILL BE RECORD HIGHS FOR
WESTERN NEBRASKA TODAY. RECORD AT LBF 91 FOR TODAY. LOT OF CIRRUS
PUSHING OVER THE RIDGE THIS MORNING. MODELS ALWAYS TEND TO UNDER
ESTIMATE THIS. 850MB TEMPERATURES AROUND 25C WHICH WOULD TRANSLATE
TO LOW 90S. RUC COMING UP WITH 95 FOR NORTH PLATTE WHERE MORE
INSOLATION EXPECTED AND WARM FRONT MAKING BIG PUSH. SOME CONVECTION
EXPECTED ON THE EASTERN PLAINS OF WYOMING AND COLORADO LATE THIS
AFTERNOON INTO EARLY EVENING...BUT WILL STRUGGLE TO MOVE INTO THE
NEBRASKA PANHANDLE AND HAVE LEFT THE FORECAST DRY FOR NOW.
TEMPERATURES TO STAY WARM WITH WAA AND SOUTHERLY FLOW TONIGHT
AHEAD OF THE TUESDAY SYSTEM DROPPING ACROSS THE NORTHERN PLAINS.
LOWS EXPECTED IN THE 50S AND 60S.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 334 AM CDT MON MAY 13 2013
A HOT DAY STILL ON TAP FOR TUESDAY...ESPECIALLY ACROSS CENTRAL INTO
SOUTHWEST NEBRASKA. SOME TIMING DIFFERENCES REMAIN WITH THE FRONTAL
PASSAGE. THE 13/00Z NAM CONTINUES TO OFFER THE FASTEST
SOLUTION...AND HAS THE FRONT MOVING INTO CENTRAL AND SOUTHWEST
NEBRASKA BY EARLY AFTERNOON. THE ECMWF AND GFS ARE SLOWER AND BRING
THE FRONT IN TOWARD EVENING. THE NAM COULD BE ONTO SOMETHING...AS IT
MAY BE FASTER AS A RESULT OF A CONVECTIVE COMPLEX ROLLING ACROSS ND
EARLY TUESDAY MORNING. THIS COULD GIVE THE FRONT AN EXTRA PUSH WITH
ANY OUTFLOW FROM THE COMPLEX. A QUICK GLANCE AT THE NEW 13/06Z NAM
SUGGESTS THE FRONT NOW A TAD SLOWER. AT THIS TIME WILL STICK CLOSE
TO THE PREVIOUS FORECAST...WHICH SIDED TOWARD A SLOWER FRONTAL
PASSAGE. WILL CONTINUE THE HOT HIGH TEMPERATURES IN THE MID AND
UPPER 90S ACROSS SOUTHWEST INTO CENTRAL NEBRASKA AHEAD OF THE FRONT.
VERY FAVORABLE CONDITIONS DEVELOP JUST AHEAD OF THE FRONT FOR THE
HOT WEATHER...WITH WEST TO SOUTHWEST SFC WINDS AND DEEP MIXING UP
THROUGH 600 MB. A FIRE WEATHER CONCERN WILL DEVELOP AHEAD OF THE
FRONT AS WELL DUE TO THE DRY CONDITIONS AND DEEP MIXING. MODELS
INDICATE WIND SPEEDS NOT QUITE TO RED FLAG CRITERIA...BUT WINDS MAY
END UP BEING STRONGER THAN THE MODELS INDICATE DUE TO SUCH DEEP
MIXING AHEAD OF THE FRONT. ALSO A CONCERN WOULD BE ANY DRY LIGHTNING
ASSOCIATED WITH THE ISOLATED HIGH BASED STORMS THAT DEVELOP ALONG
THE FRONT AS THE CAP WEAKENS DURING THE MID TO LATE AFTERNOON.
SLIGHT CHANCES FOR STORMS CONTINUE TUESDAY NIGHT AS AN AREA OF
ELEVATED INSTABILITY DEVELOPS TO THE NORTH OF THE COLD FRONT WHICH
WILL BE MOVING SOUTH INTO KS. A WEAK UPPER LEVEL DISTURBANCE WILL
MOVE EAST ACROSS THE AREA AFTER MIDNIGHT AND INTERACT WITH THE
INSTABILITY...SO THE SLIGHT CHANCES FOR PRECIP WILL BE
MAINTAINED.
SOMEWHAT COOLER AND DRIER AIR FILTERS ACROSS THE AREA WEDNESDAY AS
THE COLD FRONT STALLS ACROSS KS.
THUNDERSTORM CHANCES BEGIN TO INCREASE THURSDAY AND THURSDAY NIGHT
ACROSS WESTERN AND NORTH CENTRAL NEBRASKA. THE FRONT WHICH STALLED
WEDNESDAY ACROSS KS...WILL BEGIN TO LIFT NORTH AS A WARM FRONT INTO
WESTERN AND NORTH CENTRAL NEBRASKA THURSDAY. AS THIS OCCURS...GULF
MOISTURE WILL SURGE NORTH INTO THE AREA. THE 13/00Z GFS INDICATES
H85 DEW PTS RISING INTO THE 10 TO 12C RANGE DURING THE DAY
THURSDAY...AND INCREASING FURTHER TO 13 TO 15C THURSDAY NIGHT AS THE
LOW LEVEL JET STRENGTHENS. AT THE SAME TIME...SEVERAL SUBTLE UPPER
LEVEL WAVES EJECT NORTHEAST ACROSS THE AREA FROM DEVELOPING WESTERN
CONUS UPPER TROUGH. THIS SET UP WOULD APPEAR FAVORABLE FOR
THUNDERSTORM DEVELOPMENT ACROSS WESTERN NEBRASKA DURING THE LATE
AFTERNOON...BECOMING MORE WIDESPREAD DURING THE EVENING AS THE
SOUTHERLY LOW LEVEL JET INTENSIFIES. THE GFS OFFERS JUST THIS
SCENARIO...WITH THE ECMWF SIMILAR BUT A LITTLE FARTHER EAST WITH THE
BETTER MOISTURE ACROSS CENTRAL NEBRASKA. NAM MODEL NOT QUITE OUT FAR
ENOUGH TO HELP WITH THIS FORECAST PERIOD YET. FOR NOW WILL NOT GET
CARRIED AWAY WITH POPS...WITH THE GFS PROBABLY A TAD ON THE MOIST
SIDE BOTH WITH THE AMOUNT OF MOISTURE AND QPF.
WITH THE UPPER TROUGH REMAINING TO OUR WEST THROUGH SATURDAY
NIGHT...ACTIVE WEATHER WILL CONTINUE. STILL TOO EARLY TO PIN DOWN
EXACTLY WHERE THE BEST FOCUS FOR THUNDERSTORMS WILL BE...BUT
DEVELOPMENT IN OR JUST EAST OF OUR FORECAST AREA SEEMS LIKELY BOTH
FRIDAY AND SATURDAY.
BY SUNDAY BOTH THE 13/00Z RUNS OF THE ECMWF AND GFS DRIVE A COLD
FRONT SOUTHEAST THROUGH THE AREA. THIS WOULD PLACE THE BEST FOCUS
FOR RAIN TO OUR EAST...BUT FOR NOW WILL MAINTAIN THE CHANCES GOING
IN CASE THE FRONT SLOWS SOMEWHAT.
TEMPERATURE WISE...WITH THE INCREASED CLOUD COVER AND MOISTURE...80S
SEEM REASONABLE THURSDAY THROUGH SATURDAY...WITH COOLER UPPER 60S
AND 70S BEHIND THE FRONT SUNDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1124 PM CDT SUN MAY 12 2013
VFR IS EXPECTED OVERNIGHT THROUGH 00Z MONDAY EVENING. THEREAFTER A
COLD FRONT MAY BE SUFFICIENT TO SPARK ISOLATED THUNDERSTORMS ALONG
AND SOUTH OF INTERSTATE 80. ELSEWHERE...VFR SHOULD PREVAIL THROUGH
06Z MONDAY EVENING.
&&
.FIRE WEATHER...
ISSUED AT 334 AM CDT MON MAY 13 2013
WITH TEMPERATURES SOARING TODAY OVER WESTERN NEBRASKA AND DEWPOINTS
IN THE 30S AND 40S MINIMUM RELATIVE HUMIDITIES WILL FALL INTO THE
TEENS ACROSS WESTERN NEBRASKA...BASICALLY WHERE THEY HAVE BEEN THE
LAST SEVERAL DAYS. TUESDAY WILL BE SIMILAR AHEAD OF THE FRONT.
WINDS OVER NORTHERN NEBRASKA WILL BE 10 TO 15 MPH WITH SOME GUSTS
TO THE LOW 20S MAKING IT MARGINAL FOR HIGHLIGHTS. WILL HOLD OFF
FOR NOW. TUESDAY AHEAD OF THE FRONT ACROSS SOUTHWEST INTO CENTRAL
NEBRASKA...HIGHLIGHTS LOOK POSSIBLE...AS WINDS FROM THE SOUTHWEST
INCREASE DUE TO DEEP MIXING...AND DRY LIGHTNING IS POSSIBLE AS
WELL DUE TO THE HIGH BASED NATURE OF ANY STORM THAT WOULD HAPPEN
TO DEVELOP ALONG THE FRONT.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...POWER
SHORT TERM...TAYLOR
LONG TERM...POWER
AVIATION...CDC
FIRE WEATHER...POWER
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
616 PM CDT TUE MAY 14 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 211 PM CDT TUE MAY 14 2013
FRONT CONTINUES TO MOVE ACROSS THE CWA THIS AFTERNOON. RECORD HEAT
OUT AHEAD OF THE FRONT WITH LOW TO EVEN MID 100S ACROSS NORTHWEST
IOWA AND PORTIONS OF SOUTHWEST MINNESOTA...AND STILL LOW TO MID 90S
BEHIND THE FRONT ACROSS SOUTHEAST SOUTH DAKOTA. WITH DEWPOINTS
MIXING OUT...NOT MUCH IN THE WAY OF INSTABILITY AHEAD OF THE FRONT.
ALTHOUGH THE HRRR AND RUC HAVE CONTINUED TO SHOW SOME ISOLATED
DEVELOPMENT ALONG THE FRONT BY 22Z. GIVEN THAT BOTH OF THESE SHORT
RANGE MODELS ARE DOING A PRETTY GOOD JOB WITH SURFACE TEMPS AND
DEWPOINTS..THINK SOME ISOLATED CONVECTION MAY FIRE AS WE MIX THROUGH
WHATEVER CAP THERE IS. HOWEVER LOOKS LIKE THIS THREAT IS MAINLY
SOUTH AND SOUTHEAST OF OUR CWA...THUS WILL KEEP THE FORECAST DRY
THROUGH THE EVENING. WEAK COLD AIR ADVECTION CONTINUES THROUGH THE
NIGHT...WITH WINDS WEAKENING. THUS WHILE LOWS WILL BE ABOVE
NORMAL...MAY STILL SEE THEM GET DOWN INTO THE LOW TO MID 50S BY
MORNING IN MOST LOCATIONS.
MID LEVEL FRONTAL BOUNDARY LINGERS OVERHEAD TONIGHT INTO
TOMORROW...WITH A WEAK WAVE RIDING OVER THE RIDGE. SO WILL SEE A
REGION OF WEAK LIFT AND DECENT MID LEVEL LAPSE RATES. HOWEVER THETAE
ADVECTION IS PRETTY WEEK...AND LOW LEVELS WILL REMAIN VERY DRY. WILL
PROBABLY SEE SOME ELEVATED CONVECTION FORM ACROSS WESTERN NEBRASKA
AND SOUTH DAKOTA TONIGHT...WHICH WILL TRY TO MOVE EAST TOWARDS OUR
AREA. HOWEVER GIVEN THE ABOVE LIMITATIONS...THINK THE CHANCE OF
MEASURABLE PRECIP IN OUR CWA IS TOO LOW TO MENTION AT THIS TIME.
HOWEVER CAN NOT RULE OUT AN ISOLATED SHOWER OR SOME SPRINKLES
REACHING THE GROUND ANYTIME FROM LATE TONIGHT THROUGH THE DAY
TOMORROW. HIGH TEMPERATURES A BIT TRICKY GIVEN CLOUD COVER
POTENTIAL. BUT FEEL WE WILL SEE PERIODS OF SUN AS WELL...WITH
GENERALLY PARTLY TO AT TIMES MOSTLY SUNNY SKIES. AND RECENTLY WE
HAVE BEEN GETTING WARMER THAN JUST ABOUT EVERY GUIDANCE...SO DESPITE
CLOUD COVER CONCERNS WENT AHEAD AND RAISED HIGHS A COUPLE
DEGREES...GENERALLY IN THE UPPER 70S TO AROUND 80.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 325 PM CDT TUE MAY 14 2013
THE FRONT SOUTH OF THE AREA WILL BEGIN TO MOVE NORTH AS A WARM
FRONT WEDNESDAY NIGHT AND SHOULD BEGIN TO BRING SOME MORE MOIST
AND UNSTABLE AIR INTO THE AREA BY THE END OF THE NIGHT. LOW
TEMPERATURES SHOULD BE NEAR SEASONAL VALUES BEFORE MOST OF THE
HUMID AIR GETS HERE ON THURSDAY. THE THREAT OF THUNDERSTORMS IN
WARM ADVECTION PATTERN NORTH OF THE FRONT MAY BEGIN IN THE SOUTH
LATE WEDNESDAY NIGHT. THIS THREAT SHOULD GENERALLY BE AROUND FOR
THE REST OF THE FORECAST...ALTHOUGH WILL KEEP POPS MINIMAL ON
FRIDAY AS IT LOOKS LIKE THERE MAY BE A BREAK ON THAT DAY. THEN THE
THREAT WILL INCREASE AGAIN FOR THE WEEKEND AS MAIN UPPER TROUGH
APPROACHES...WITH THE PEAK THREAT SATURDAY NIGHT. A SEVERE THREAT
OR MODESTLY HEAVY RAIN SEEMS POSSIBLE OVER THE WEEKEND.
INSTABILITY AND MOISTURE UNCERTAIN WITH IT BEING WELL DISCUSSED
ABOUT THE TOO HIGH GFS DEW POINTS. IN ANY EVENT TEMPERATURES WILL
BE WARM DURING THE DAY BUT EVEN WARMER RELATIVE TO NORMAL AT
NIGHT...OR NO REAL HOT SPELL.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 614 PM CDT TUE MAY 14 2013
VFR THROUGH THE PERIOD. NORTHWEST WINDS WILL GUST TO NEAR 30 MPH
THROUGH ABOUT 1Z THEN TAPER OFF PRETTY QUICKLY AFTER SUNSET.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...RED FLAG WARNING UNTIL 8 PM CDT THIS EVENING FOR SDZ255>258.
MN...RED FLAG WARNING UNTIL 8 PM CDT THIS EVENING FOR MNZ900.
IA...RED FLAG WARNING UNTIL 8 PM CDT THIS EVENING FOR IAZ300-301.
NE...RED FLAG WARNING UNTIL 8 PM CDT THIS EVENING FOR NEZ249.
&&
$$
SHORT TERM...CHENARD
LONG TERM...
AVIATION...08
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
138 PM CDT MON MAY 13 2013
.UPDATE...
ISSUED AT 1023 AM CDT MON MAY 13 2013
IN GENERAL EARLIER FORECAST IS BEHAVING FAIRLY WELL WITH A LITTLE
SLOWER DECREASE IN THE HIGH CLOUD COVER. STILL EXPECT WITH THE
CLOUDS THINNING OUT BY AFTERNOON THAT THE HEATING AND WARMING WILL
PUT TEMPERATURES CLOSE TO FORECAST HIGHS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 347 AM CDT MON MAY 13 2013
OBVIOUSLY THE MAIN CONCERN TODAY IS FIRE WEATHER. TEMPERATURES WILL
BE WELL ABOVE SEASONAL NORMALS AS A SURFACE TROUGH OF LOW PRESSURE
MOVES EASTWARD ACROSS OUR FORECAST AREA. THIS SURFACE TROUGH WILL
CAUSE A WIND SHIFT FROM THE SOUTHWEST TO NORTHWEST BEFORE IT STALLS
OUT LATE IN THE DAY IN NORTHWEST IOWA. GIVEN THE WINDS OFF THE
SURFACE AND MIXING POTENTIAL...OUR ZONES IN IOWA AROUND THE IOWA
GREAT LAKES AND STORM LAKE AREAS...AS WELL AS SOME OF THE SOUTHERN
SECTIONS IN SOUTHWEST MINNESOTA...WILL PUSH RED FLAG CRITERIA BUT
PROBABLY ONLY FOR A COUPLE OF HOURS. THIS IS BECAUSE BETWEEN 21Z AND
00Z...THE WINDS SHOULD DECREASE A FAIR AMOUNT IN THE AXIS OF THE
SURFACE TROUGH WHICH IS RIGHT IN THOSE AREAS. THEREFORE IT WILL BE A
BREEZY TO MODERATELY WINDY DAY IN THOSE AREAS...GOOD FOR A VERY HIGH
FIRE DANGER...BUT POSSIBLY JUST NOT QUITE THERE FOR A BONAFIDE RED
FLAG WARNING. THE SAME HOLDS TRUE FOR BEHIND THE SURFACE TROUGH...
WHICH IS ALONG AND WEST OF THE JAMES RIVER VALLEY. MINIMUM HUMIDITY
VALUES WILL LIKELY REALLY TANK IN THOSE ZONES TO LESS THAN 20
PERCENT. HOWEVER IN OUR WESTERN ZONES THIS AFTERNOON...SUSTAINED
NORTHWEST SURFACE WINDS WILL LIKELY STAY LESS THEN 20 MPH MUCH OF
THE TIME...WITH GUSTS FREQUENTLY AROUND 25 TO 27 MPH. SO AGAIN...
JUST A BIT BELOW RED FLAG CRITERIA...BUT CERTAINLY ELEVATED FIRE
DANGER. THE ONE THING THAT COULD REALLY ALTER THIS SCENARIO
SIGNIFICANTLY IS IF THE MIXED LAYER WINDS WHICH ARE FORECAST TO BE
AROUND 25 KNOTS IN OUR FORECAST AREA...BECOME STRONGER THEN
ANTICIPATED. IF THAT HAPPENS...WE COULD GO RED FLAG OVER MANY AREAS.
CONCERNING HUMIDITY...MUCH OF THE MODEL DEW POINT GUIDANCE IS WAY
TOO HIGH. PRIMARILY BLENDED THE REALLY DRY RAP MODEL DEW POINTS INTO
CONSENSUS SHORT. THIS SEEMED TO GIVE REASONABLE VALUES...AS IT SEEMS
THAT EACH DAY WE CANNOT GO LOW ENOUGH ON THE DEW POINTS...AND THUS
THE HUMIDITY VALUES. RIGHT NOW...DEW POINTS ARE IN THE 30S WEST
RIVER...AND LOWER TO MID 40S IN SOUTH CENTRAL NEBRASKA. THEREFORE
LOOKING AT TRAJECTORIES EITHER FOR A SOUTHWEST WIND OR NORTHWEST
WIND...MADE SURE NOT TO GO ABOVE THOSE VALUES UPSTREAM.
OBVIOUSLY THE MAIN CONCERN TODAY IS FIRE WEATHER. TEMPERATURES WILL
BE WELL ABOVE SEASONAL NORMALS AS A SURFACE TROUGH OF LOW PRESSURE
MOVES EASTWARD ACROSS OUR FORECAST AREA. THIS SURFACE TROUGH WILL
CAUSE A WIND SHIFT FROM THE SOUTHWEST TO NORTHWEST BEFORE IT STALLS
OUT LATE IN THE DAY IN NORTHWEST IOWA. GIVEN THE WINDS OFF THE
SURFACE AND MIXING POTENTIAL...OUR ZONES IN IOWA AROUND THE IOWA
GREAT LAKES AND STORM LAKE AREAS...AS WELL AS SOME OF THE SOUTHERN
SECTIONS IN SOUTHWEST MINNESOTA...WILL PUSH RED FLAG CRITERIA BUT
PROBABLY ONLY FOR A COUPLE OF HOURS. THIS IS BECAUSE BETWEEN 21Z AND
00Z...THE WINDS SHOULD DECREASE A FAIR AMOUNT IN THE AXIS OF THE
SURFACE TROUGH WHICH IS RIGHT IN THOSE AREAS. THEREFORE IT WILL BE A
BREEZY TO MODERATELY WINDY DAY IN THOSE AREAS...GOOD FOR A VERY HIGH
FIRE DANGER...BUT POSSIBLY JUST NOT QUITE THERE FOR A BONAFIDE RED
FLAG WARNING. THE SAME HOLDS TRUE FOR BEHIND THE SURFACE TROUGH...
WHICH IS ALONG AND WEST OF THE JAMES RIVER VALLEY. MINIMUM HUMIDITY
VALUES WILL LIKELY REALLY TANK IN THOSE ZONES TO LESS THAN 20
PERCENT. HOWEVER IN OUR WESTERN ZONES THIS AFTERNOON...SUSTAINED
NORTHWEST SURFACE WINDS WILL LIKELY STAY LESS THEN 20 MPH MUCH OF
THE TIME...WITH GUSTS FREQUENTLY AROUND 25 TO 27 MPH. SO AGAIN...
JUST A BIT BELOW RED FLAG CRITERIA...BUT CERTAINLY ELEVATED FIRE
DANGER. THE ONE THING THAT COULD REALLY ALTER THIS SCENARIO
SIGNIFICANTLY IS IF THE MIXED LAYER WINDS WHICH ARE FORECAST TO BE
AROUND 25 KNOTS IN OUR FORECAST AREA...BECOME STRONGER THEN
ANTICIPATED. IF THAT HAPPENS...WE COULD GO RED FLAG OVER MANY AREAS.
CONCERNING HUMIDITY...MUCH OF THE MODEL DEW POINT GUIDANCE IS WAY
TOO HIGH. PRIMARILY BLENDED THE REALLY DRY RAP MODEL DEW POINTS INTO
CONSENSUS SHORT. THIS SEEMED TO GIVE REASONABLE VALUES...AS IT SEEMS
THAT EACH DAY WE CANNOT GO LOW ENOUGH ON THE DEW POINTS...AND THUS
THE HUMIDITY VALUES. RIGHT NOW...DEW POINTS ARE IN THE 30S WEST
RIVER...AND LOWER TO MID 40S IN SOUTH CENTRAL NEBRASKA. THEREFORE
LOOKING AT TRAJECTORIES EITHER FOR A SOUTHWEST WIND OR NORTHWEST
WIND...MADE SURE NOT TO GO ABOVE THOSE VALUES UPSTREAM.
WINDS WILL TAPER DOWN THIS EVENING AND TURN SOUTHERLY OVERNIGHT.
WITH THERMAL PROFILES CONTINUING TO WARM...IT WILL BE A MILD NIGHT
WITH LOWS IN THE MID 50S TO LOWER 60S.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 347 AM CDT MON MAY 13 2013
A STRONG SOUTHERLY FLOW SETS UP ON TUESDAY OUT AHEAD OF A SURFACE
TROUGH/FRONTAL BOUNDARY WHICH WILL PUSH ACROSS THE AREA IN THE
AFTERNOON. MOISTURE LOOKS TO BE MINIMAL WITH THIS SYSTEM...SO
EXPECTING IT TO BE A DRY FRONTAL PASSAGE. IT WILL BE A VERY MIXY DAY
WITH STRONG SOUTHWESTERLY WINDS OUT AHEAD OF THE FRONT...AND STRONG
NORTHWESTERLY WINDS BEHIND THE FRONT. MODELS AGAIN SEEM TO BE
OVERDOING DEWPOINTS ON TUESDAY...MOST LIKELY OVER DOING
EVAPOTRANSPIRATION...AND PROGGING DEWPOINTS WELL INTO THE 50S.
INSTEAD USED THE MIXDOWN TOOL WHICH YIELDED A BETTER ESTIMATION OF
DEWPOINTS...GENERALLY IN THE 40S...WITH SOME MOISTURE POOLING ALONG
THE FRONTAL BOUNDARY...THOUGH STILL MAY BE SLIGHTLY TOO HIGH ON
VALUES. IN ANY EVENT...WITH THE STRONG WINDS AND AFTERNOON RELATIVE
HUMIDITY VALUES FLOATING AROUND 20 TO 25 PERCENT...ISSUED A FIRE
WEATHER WATCH FOR THE ENTIRE CWA. AS HAS BEEN ADVERTISED OF
LATE...TUESDAY WILL GENERALLY BE THE WARMEST DAY OF THE WEEK WITH
ALL MODELS PROGGING 850 MB TEMPERATURES IN THE LOWER TO MID 20S C
OVER OUR EAST IN THE AFTERNOON...SO KEPT WITH LOWER TO MID 90S
THERE. WITH COLD AIR ADVECTION BEHIND THE FRONT...IT WILL BE LITTLE
COOLER TO THE WEST...WITH HIGHS IN THE MID AND UPPER 80S.
COOLER AIR WILL FILTER INTO THE REGION ON TUESDAY NIGHT WITH WINDS
DYING OFF OVERNIGHT. LOWS LOOKING TO BE IN THE UPPER 40S TO MID 50S.
WEDNESDAY AND WEDNESDAY NIGHT APPEAR TO BE PLEASANT WITH WEAK HIGH
PRESSURE BUILDING INTO THE REGION...WITH HIGHS IN THE 70S AND LOWS
IN THE 50S.
FARTHER INTO THE EXTENDED...THURSDAY THROUGH SUNDAY...LOOKS TO BE A
FAIRLY ACTIVE PERIOD WITH A NEARLY ZONAL UPPER LEVEL FLOW AT THE
START OF THE PERIOD...TRANSITIONING TO RIDGING ON FRIDAY AS A TROUGH
BEGINS TO LIFT OUT OF THE WESTERN U.S. AND INTO THE AREA BY LATE IN
THE WEEKEND. THINK MOST OF THURSDAY WILL BE DRY AND LITTLE WARMER AS
A SOUTHERLY FLOW BEGINS TO RETURN TO THE REGION WITH HIGHS IN THE
MID AND UPPER 70S. CANNOT RULE OUT SCATTERED THUNDERSTORMS FOR
THURSDAY NIGHT AND FRIDAY WITH INCREASING THETA E ADVECTION INTO THE
REGION...THOUGH WOULD BE HARD TO PIN POINT EXACT TIMING ON ANY
CONVECTIVE DEVELOPMENT THIS FAR OUT. A BETTER CHANCE OF CONVECTION
WOULD APPEAR TO BE LIKELY ON FRIDAY NIGHT AS LOW PRESSURE BEGINS TO
LIFT OUT OF THE ROCKIES. WITH CONVECTIVE PARAMETERS INCREASING
DURING THAT TIME FRAME...SEVERE STORMS WOULD SEEM MORE
LIKELY...THOUGH MODELS ARE DIFFERING A BIT ON THE PLACEMENT OF A
BOUNDARY LAYING SOMEWHERE CLOSE TO OUR AREA ON FRIDAY NIGHT AND
SATURDAY. THE UPPER LEVEL TROUGH SWINGS THROUGH THE REGION ON
SUNDAY...KEEPING A CHANCE OF CONVECTION...WITH COOLER AIR BEGINNING
TO PULL IN BEHIND THE SYSTEM.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 108 PM CDT MON MAY 13 2013
VFR EXPECTED TO CONTINUE THROUGH 14/18Z EVEN AS COLD FRONT ENTERS
THE NORTHWEST CORNER OF THE AREA INCLUDING HON BY 14/18Z. SURFACE
GUSTS TO 25 TO 30 KNOTS FROM THE WEST TO SOUTHWEST IN SOUTHWEST MN
AND NORTHWEST IA WILL DECREASE BY 23Z BUT MAY REDEVELOP AFTER
14/15Z OVER THE AREA. WINDS WILL SHIFT TO THE NORTHWEST OVER THE
NORTHWEST CORNER OF THE AREA INCLUDING HON NEAR END OF PERIOD BY
14/18Z.
&&
.FIRE WEATHER...
ISSUED AT 138 PM CDT MON MAY 13 2013
RED FLAG WARNING HAS BEEN ISSUED FOR SOUTHWEST MN PART OF AND
NORTHWEST IA FOR THIS AFTERNOON AND CONTINUES UNTIL 6 PM CDT. THE
STRONG WINDS AND LOW RELATIVE HUMIDITIES WILL BE A PROBLEM AGAIN
TUESDAY...ONLY OVER ALL OF THE AREA. THE HIGHER DEW POINTS TUESDAY
WILL BE MORE THAN COMPENSATED FOR BY THE VERY WARM TO HOT
TEMPERATURES. THERE COULD BE SOMEWHAT OF A SLIGHT LULL NEAR THE
FRONT IN THE SHIFTING ZONE BUT FEEL THE WINDS WILL BE HIGH ENOUGH
CONTINUOUSLY ENOUGH TO UPGRADE THE FIRE WEATHER WATCH TO A RED FLAG
WARNING. THIS WILL BE FOR THE SAME TIME PERIOD THE WATCH WAS FOR. WE
HAVE ALREADY HAD FIRE ACTIVITY IN SOUTHWEST MN THIS AFTERNOON AND
THE SAME COULD HAPPEN ANYWHERE TUESDAY. RECENT GREENING OF GRASSES
HAS BEEN AT LOW LEVELS AND FIRES MAY NOT BE REAL QUICK TO
START...BUT MAY SPREAD VERY QUICKLY IN THE LINGERING DORMANT TALL
GRASSES.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR SDZ255>258.
MN...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR MNZ900.
RED FLAG WARNING UNTIL 6 PM CDT THIS EVENING FOR MNZ900.
IA...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR IAZ300-301.
RED FLAG WARNING UNTIL 6 PM CDT THIS EVENING FOR IAZ301.
NE...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR NEZ249.
&&
$$
UPDATE...
SHORT TERM...MJF/JM
LONG TERM...JM
AVIATION...
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
111 PM CDT MON MAY 13 2013
.UPDATE...
ISSUED AT 1023 AM CDT MON MAY 13 2013
IN GENERAL EARLIER FORECAST IS BEHAVING FAIRLY WELL WITH A LITTLE
SLOWER DECREASE IN THE HIGH CLOUD COVER. STILL EXPECT WITH THE
CLOUDS THINNING OUT BY AFTERNOON THAT THE HEATING AND WARMING WILL
PUT TEMPERATURES CLOSE TO FORECAST HIGHS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 347 AM CDT MON MAY 13 2013
OBVIOUSLY THE MAIN CONCERN TODAY IS FIRE WEATHER. TEMPERATURES WILL
BE WELL ABOVE SEASONAL NORMALS AS A SURFACE TROUGH OF LOW PRESSURE
MOVES EASTWARD ACROSS OUR FORECAST AREA. THIS SURFACE TROUGH WILL
CAUSE A WIND SHIFT FROM THE SOUTHWEST TO NORTHWEST BEFORE IT STALLS
OUT LATE IN THE DAY IN NORTHWEST IOWA. GIVEN THE WINDS OFF THE
SURFACE AND MIXING POTENTIAL...OUR ZONES IN IOWA AROUND THE IOWA
GREAT LAKES AND STORM LAKE AREAS...AS WELL AS SOME OF THE SOUTHERN
SECTIONS IN SOUTHWEST MINNESOTA...WILL PUSH RED FLAG CRITERIA BUT
PROBABLY ONLY FOR A COUPLE OF HOURS. THIS IS BECAUSE BETWEEN 21Z AND
00Z...THE WINDS SHOULD DECREASE A FAIR AMOUNT IN THE AXIS OF THE
SURFACE TROUGH WHICH IS RIGHT IN THOSE AREAS. THEREFORE IT WILL BE A
BREEZY TO MODERATELY WINDY DAY IN THOSE AREAS...GOOD FOR A VERY HIGH
FIRE DANGER...BUT POSSIBLY JUST NOT QUITE THERE FOR A BONAFIDE RED
FLAG WARNING. THE SAME HOLDS TRUE FOR BEHIND THE SURFACE TROUGH...
WHICH IS ALONG AND WEST OF THE JAMES RIVER VALLEY. MINIMUM HUMIDITY
VALUES WILL LIKELY REALLY TANK IN THOSE ZONES TO LESS THAN 20
PERCENT. HOWEVER IN OUR WESTERN ZONES THIS AFTERNOON...SUSTAINED
NORTHWEST SURFACE WINDS WILL LIKELY STAY LESS THEN 20 MPH MUCH OF
THE TIME...WITH GUSTS FREQUENTLY AROUND 25 TO 27 MPH. SO AGAIN...
JUST A BIT BELOW RED FLAG CRITERIA...BUT CERTAINLY ELEVATED FIRE
DANGER. THE ONE THING THAT COULD REALLY ALTER THIS SCENARIO
SIGNIFICANTLY IS IF THE MIXED LAYER WINDS WHICH ARE FORECAST TO BE
AROUND 25 KNOTS IN OUR FORECAST AREA...BECOME STRONGER THEN
ANTICIPATED. IF THAT HAPPENS...WE COULD GO RED FLAG OVER MANY AREAS.
CONCERNING HUMIDITY...MUCH OF THE MODEL DEW POINT GUIDANCE IS WAY
TOO HIGH. PRIMARILY BLENDED THE REALLY DRY RAP MODEL DEW POINTS INTO
CONSENSUS SHORT. THIS SEEMED TO GIVE REASONABLE VALUES...AS IT SEEMS
THAT EACH DAY WE CANNOT GO LOW ENOUGH ON THE DEW POINTS...AND THUS
THE HUMIDITY VALUES. RIGHT NOW...DEW POINTS ARE IN THE 30S WEST
RIVER...AND LOWER TO MID 40S IN SOUTH CENTRAL NEBRASKA. THEREFORE
LOOKING AT TRAJECTORIES EITHER FOR A SOUTHWEST WIND OR NORTHWEST
WIND...MADE SURE NOT TO GO ABOVE THOSE VALUES UPSTREAM.
OBVIOUSLY THE MAIN CONCERN TODAY IS FIRE WEATHER. TEMPERATURES WILL
BE WELL ABOVE SEASONAL NORMALS AS A SURFACE TROUGH OF LOW PRESSURE
MOVES EASTWARD ACROSS OUR FORECAST AREA. THIS SURFACE TROUGH WILL
CAUSE A WIND SHIFT FROM THE SOUTHWEST TO NORTHWEST BEFORE IT STALLS
OUT LATE IN THE DAY IN NORTHWEST IOWA. GIVEN THE WINDS OFF THE
SURFACE AND MIXING POTENTIAL...OUR ZONES IN IOWA AROUND THE IOWA
GREAT LAKES AND STORM LAKE AREAS...AS WELL AS SOME OF THE SOUTHERN
SECTIONS IN SOUTHWEST MINNESOTA...WILL PUSH RED FLAG CRITERIA BUT
PROBABLY ONLY FOR A COUPLE OF HOURS. THIS IS BECAUSE BETWEEN 21Z AND
00Z...THE WINDS SHOULD DECREASE A FAIR AMOUNT IN THE AXIS OF THE
SURFACE TROUGH WHICH IS RIGHT IN THOSE AREAS. THEREFORE IT WILL BE A
BREEZY TO MODERATELY WINDY DAY IN THOSE AREAS...GOOD FOR A VERY HIGH
FIRE DANGER...BUT POSSIBLY JUST NOT QUITE THERE FOR A BONAFIDE RED
FLAG WARNING. THE SAME HOLDS TRUE FOR BEHIND THE SURFACE TROUGH...
WHICH IS ALONG AND WEST OF THE JAMES RIVER VALLEY. MINIMUM HUMIDITY
VALUES WILL LIKELY REALLY TANK IN THOSE ZONES TO LESS THAN 20
PERCENT. HOWEVER IN OUR WESTERN ZONES THIS AFTERNOON...SUSTAINED
NORTHWEST SURFACE WINDS WILL LIKELY STAY LESS THEN 20 MPH MUCH OF
THE TIME...WITH GUSTS FREQUENTLY AROUND 25 TO 27 MPH. SO AGAIN...
JUST A BIT BELOW RED FLAG CRITERIA...BUT CERTAINLY ELEVATED FIRE
DANGER. THE ONE THING THAT COULD REALLY ALTER THIS SCENARIO
SIGNIFICANTLY IS IF THE MIXED LAYER WINDS WHICH ARE FORECAST TO BE
AROUND 25 KNOTS IN OUR FORECAST AREA...BECOME STRONGER THEN
ANTICIPATED. IF THAT HAPPENS...WE COULD GO RED FLAG OVER MANY AREAS.
CONCERNING HUMIDITY...MUCH OF THE MODEL DEW POINT GUIDANCE IS WAY
TOO HIGH. PRIMARILY BLENDED THE REALLY DRY RAP MODEL DEW POINTS INTO
CONSENSUS SHORT. THIS SEEMED TO GIVE REASONABLE VALUES...AS IT SEEMS
THAT EACH DAY WE CANNOT GO LOW ENOUGH ON THE DEW POINTS...AND THUS
THE HUMIDITY VALUES. RIGHT NOW...DEW POINTS ARE IN THE 30S WEST
RIVER...AND LOWER TO MID 40S IN SOUTH CENTRAL NEBRASKA. THEREFORE
LOOKING AT TRAJECTORIES EITHER FOR A SOUTHWEST WIND OR NORTHWEST
WIND...MADE SURE NOT TO GO ABOVE THOSE VALUES UPSTREAM.
WINDS WILL TAPER DOWN THIS EVENING AND TURN SOUTHERLY OVERNIGHT.
WITH THERMAL PROFILES CONTINUING TO WARM...IT WILL BE A MILD NIGHT
WITH LOWS IN THE MID 50S TO LOWER 60S.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 347 AM CDT MON MAY 13 2013
A STRONG SOUTHERLY FLOW SETS UP ON TUESDAY OUT AHEAD OF A SURFACE
TROUGH/FRONTAL BOUNDARY WHICH WILL PUSH ACROSS THE AREA IN THE
AFTERNOON. MOISTURE LOOKS TO BE MINIMAL WITH THIS SYSTEM...SO
EXPECTING IT TO BE A DRY FRONTAL PASSAGE. IT WILL BE A VERY MIXY DAY
WITH STRONG SOUTHWESTERLY WINDS OUT AHEAD OF THE FRONT...AND STRONG
NORTHWESTERLY WINDS BEHIND THE FRONT. MODELS AGAIN SEEM TO BE
OVERDOING DEWPOINTS ON TUESDAY...MOST LIKELY OVER DOING
EVAPOTRANSPIRATION...AND PROGGING DEWPOINTS WELL INTO THE 50S.
INSTEAD USED THE MIXDOWN TOOL WHICH YIELDED A BETTER ESTIMATION OF
DEWPOINTS...GENERALLY IN THE 40S...WITH SOME MOISTURE POOLING ALONG
THE FRONTAL BOUNDARY...THOUGH STILL MAY BE SLIGHTLY TOO HIGH ON
VALUES. IN ANY EVENT...WITH THE STRONG WINDS AND AFTERNOON RELATIVE
HUMIDITY VALUES FLOATING AROUND 20 TO 25 PERCENT...ISSUED A FIRE
WEATHER WATCH FOR THE ENTIRE CWA. AS HAS BEEN ADVERTISED OF
LATE...TUESDAY WILL GENERALLY BE THE WARMEST DAY OF THE WEEK WITH
ALL MODELS PROGGING 850 MB TEMPERATURES IN THE LOWER TO MID 20S C
OVER OUR EAST IN THE AFTERNOON...SO KEPT WITH LOWER TO MID 90S
THERE. WITH COLD AIR ADVECTION BEHIND THE FRONT...IT WILL BE LITTLE
COOLER TO THE WEST...WITH HIGHS IN THE MID AND UPPER 80S.
COOLER AIR WILL FILTER INTO THE REGION ON TUESDAY NIGHT WITH WINDS
DYING OFF OVERNIGHT. LOWS LOOKING TO BE IN THE UPPER 40S TO MID 50S.
WEDNESDAY AND WEDNESDAY NIGHT APPEAR TO BE PLEASANT WITH WEAK HIGH
PRESSURE BUILDING INTO THE REGION...WITH HIGHS IN THE 70S AND LOWS
IN THE 50S.
FARTHER INTO THE EXTENDED...THURSDAY THROUGH SUNDAY...LOOKS TO BE A
FAIRLY ACTIVE PERIOD WITH A NEARLY ZONAL UPPER LEVEL FLOW AT THE
START OF THE PERIOD...TRANSITIONING TO RIDGING ON FRIDAY AS A TROUGH
BEGINS TO LIFT OUT OF THE WESTERN U.S. AND INTO THE AREA BY LATE IN
THE WEEKEND. THINK MOST OF THURSDAY WILL BE DRY AND LITTLE WARMER AS
A SOUTHERLY FLOW BEGINS TO RETURN TO THE REGION WITH HIGHS IN THE
MID AND UPPER 70S. CANNOT RULE OUT SCATTERED THUNDERSTORMS FOR
THURSDAY NIGHT AND FRIDAY WITH INCREASING THETA E ADVECTION INTO THE
REGION...THOUGH WOULD BE HARD TO PIN POINT EXACT TIMING ON ANY
CONVECTIVE DEVELOPMENT THIS FAR OUT. A BETTER CHANCE OF CONVECTION
WOULD APPEAR TO BE LIKELY ON FRIDAY NIGHT AS LOW PRESSURE BEGINS TO
LIFT OUT OF THE ROCKIES. WITH CONVECTIVE PARAMETERS INCREASING
DURING THAT TIME FRAME...SEVERE STORMS WOULD SEEM MORE
LIKELY...THOUGH MODELS ARE DIFFERING A BIT ON THE PLACEMENT OF A
BOUNDARY LAYING SOMEWHERE CLOSE TO OUR AREA ON FRIDAY NIGHT AND
SATURDAY. THE UPPER LEVEL TROUGH SWINGS THROUGH THE REGION ON
SUNDAY...KEEPING A CHANCE OF CONVECTION...WITH COOLER AIR BEGINNING
TO PULL IN BEHIND THE SYSTEM.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 108 PM CDT MON MAY 13 2013
VFR EXPECTED TO CONTINUE THROUGH 14/18Z EVEN AS COLD FRONT ENTERS
THE NORTHWEST CORNER OF THE AREA INCLUDING HON BY 14/18Z. SURFACE
GUSTS TO 25 TO 30 KNOTS FROM THE WEST TO SOUTHWEST IN SOUTHWEST MN
AND NORTHWEST IA WILL DECREASE BY 23Z BUT MAY REDEVELOP AFTER
14/15Z OVER THE AREA. WINDS WILL SHIFT TO THE NORTHWEST OVER THE
NORTHWEST CORNER OF THE AREA INCLUDING HON NEAR END OF PERIOD BY
14/18Z.
&&
.FIRE WEATHER...
ISSUED AT 1023 AM CDT MON MAY 13 2013
FIRE WEATHER WAS DISCUSSED EXTENSIVELY IN BOTH SHORT AND LONG TERM
SECTIONS EARLIER. MAIN PROBLEM WITH WINDS COMING UP A LITTLE
FASTER THAN EXPECTED IN OUR EAST IS A POSSIBLE NEED FOR A RED FLAG
WARNING FOR THIS AFTERNOON IN OUR EAST...EVEN THOUGH DEW POINTS
ARE COMING UP ABOUT AS WE HAD. WILL TRY TO ISSUE BY THE START OF
THE AFTERNOON IF WE DECIDE ONE IS NEEDED. OF COURSE WILL ALSO BE
CHECKING ON A POSSIBLE UPGRADE OF TUESDAY WATCH TO A WARNING.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR SDZ255>258.
MN...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR MNZ900.
RED FLAG WARNING UNTIL 6 PM CDT THIS EVENING FOR MNZ900.
IA...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR IAZ300-301.
RED FLAG WARNING UNTIL 6 PM CDT THIS EVENING FOR IAZ301.
NE...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR NEZ249.
&&
$$
UPDATE...
SHORT TERM...MJF/JM
LONG TERM...JM
AVIATION...
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1030 AM CDT MON MAY 13 2013
.UPDATE...
ISSUED AT 1023 AM CDT MON MAY 13 2013
IN GENERAL EARLIER FORECAST IS BEHAVING FAIRLY WELL WITH A LITTLE
SLOWER DECREASE IN THE HIGH CLOUD COVER. STILL EXPECT WITH THE
CLOUDS THINNING OUT BY AFTERNOON THAT THE HEATING AND WARMING WILL
PUT TEMPERATURES CLOSE TO FORECAST HIGHS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 347 AM CDT MON MAY 13 2013
OBVIOUSLY THE MAIN CONCERN TODAY IS FIRE WEATHER. TEMPERATURES WILL
BE WELL ABOVE SEASONAL NORMALS AS A SURFACE TROUGH OF LOW PRESSURE
MOVES EASTWARD ACROSS OUR FORECAST AREA. THIS SURFACE TROUGH WILL
CAUSE A WIND SHIFT FROM THE SOUTHWEST TO NORTHWEST BEFORE IT STALLS
OUT LATE IN THE DAY IN NORTHWEST IOWA. GIVEN THE WINDS OFF THE
SURFACE AND MIXING POTENTIAL...OUR ZONES IN IOWA AROUND THE IOWA
GREAT LAKES AND STORM LAKE AREAS...AS WELL AS SOME OF THE SOUTHERN
SECTIONS IN SOUTHWEST MINNESOTA...WILL PUSH RED FLAG CRITERIA BUT
PROBABLY ONLY FOR A COUPLE OF HOURS. THIS IS BECAUSE BETWEEN 21Z AND
00Z...THE WINDS SHOULD DECREASE A FAIR AMOUNT IN THE AXIS OF THE
SURFACE TROUGH WHICH IS RIGHT IN THOSE AREAS. THEREFORE IT WILL BE A
BREEZY TO MODERATELY WINDY DAY IN THOSE AREAS...GOOD FOR A VERY HIGH
FIRE DANGER...BUT POSSIBLY JUST NOT QUITE THERE FOR A BONAFIDE RED
FLAG WARNING. THE SAME HOLDS TRUE FOR BEHIND THE SURFACE TROUGH...
WHICH IS ALONG AND WEST OF THE JAMES RIVER VALLEY. MINIMUM HUMIDITY
VALUES WILL LIKELY REALLY TANK IN THOSE ZONES TO LESS THAN 20
PERCENT. HOWEVER IN OUR WESTERN ZONES THIS AFTERNOON...SUSTAINED
NORTHWEST SURFACE WINDS WILL LIKELY STAY LESS THEN 20 MPH MUCH OF
THE TIME...WITH GUSTS FREQUENTLY AROUND 25 TO 27 MPH. SO AGAIN...
JUST A BIT BELOW RED FLAG CRITERIA...BUT CERTAINLY ELEVATED FIRE
DANGER. THE ONE THING THAT COULD REALLY ALTER THIS SCENARIO
SIGNIFICANTLY IS IF THE MIXED LAYER WINDS WHICH ARE FORECAST TO BE
AROUND 25 KNOTS IN OUR FORECAST AREA...BECOME STRONGER THEN
ANTICIPATED. IF THAT HAPPENS...WE COULD GO RED FLAG OVER MANY AREAS.
CONCERNING HUMIDITY...MUCH OF THE MODEL DEW POINT GUIDANCE IS WAY
TOO HIGH. PRIMARILY BLENDED THE REALLY DRY RAP MODEL DEW POINTS INTO
CONSENSUS SHORT. THIS SEEMED TO GIVE REASONABLE VALUES...AS IT SEEMS
THAT EACH DAY WE CANNOT GO LOW ENOUGH ON THE DEW POINTS...AND THUS
THE HUMIDITY VALUES. RIGHT NOW...DEW POINTS ARE IN THE 30S WEST
RIVER...AND LOWER TO MID 40S IN SOUTH CENTRAL NEBRASKA. THEREFORE
LOOKING AT TRAJECTORIES EITHER FOR A SOUTHWEST WIND OR NORTHWEST
WIND...MADE SURE NOT TO GO ABOVE THOSE VALUES UPSTREAM.
OBVIOUSLY THE MAIN CONCERN TODAY IS FIRE WEATHER. TEMPERATURES WILL
BE WELL ABOVE SEASONAL NORMALS AS A SURFACE TROUGH OF LOW PRESSURE
MOVES EASTWARD ACROSS OUR FORECAST AREA. THIS SURFACE TROUGH WILL
CAUSE A WIND SHIFT FROM THE SOUTHWEST TO NORTHWEST BEFORE IT STALLS
OUT LATE IN THE DAY IN NORTHWEST IOWA. GIVEN THE WINDS OFF THE
SURFACE AND MIXING POTENTIAL...OUR ZONES IN IOWA AROUND THE IOWA
GREAT LAKES AND STORM LAKE AREAS...AS WELL AS SOME OF THE SOUTHERN
SECTIONS IN SOUTHWEST MINNESOTA...WILL PUSH RED FLAG CRITERIA BUT
PROBABLY ONLY FOR A COUPLE OF HOURS. THIS IS BECAUSE BETWEEN 21Z AND
00Z...THE WINDS SHOULD DECREASE A FAIR AMOUNT IN THE AXIS OF THE
SURFACE TROUGH WHICH IS RIGHT IN THOSE AREAS. THEREFORE IT WILL BE A
BREEZY TO MODERATELY WINDY DAY IN THOSE AREAS...GOOD FOR A VERY HIGH
FIRE DANGER...BUT POSSIBLY JUST NOT QUITE THERE FOR A BONAFIDE RED
FLAG WARNING. THE SAME HOLDS TRUE FOR BEHIND THE SURFACE TROUGH...
WHICH IS ALONG AND WEST OF THE JAMES RIVER VALLEY. MINIMUM HUMIDITY
VALUES WILL LIKELY REALLY TANK IN THOSE ZONES TO LESS THAN 20
PERCENT. HOWEVER IN OUR WESTERN ZONES THIS AFTERNOON...SUSTAINED
NORTHWEST SURFACE WINDS WILL LIKELY STAY LESS THEN 20 MPH MUCH OF
THE TIME...WITH GUSTS FREQUENTLY AROUND 25 TO 27 MPH. SO AGAIN...
JUST A BIT BELOW RED FLAG CRITERIA...BUT CERTAINLY ELEVATED FIRE
DANGER. THE ONE THING THAT COULD REALLY ALTER THIS SCENARIO
SIGNIFICANTLY IS IF THE MIXED LAYER WINDS WHICH ARE FORECAST TO BE
AROUND 25 KNOTS IN OUR FORECAST AREA...BECOME STRONGER THEN
ANTICIPATED. IF THAT HAPPENS...WE COULD GO RED FLAG OVER MANY AREAS.
CONCERNING HUMIDITY...MUCH OF THE MODEL DEW POINT GUIDANCE IS WAY
TOO HIGH. PRIMARILY BLENDED THE REALLY DRY RAP MODEL DEW POINTS INTO
CONSENSUS SHORT. THIS SEEMED TO GIVE REASONABLE VALUES...AS IT SEEMS
THAT EACH DAY WE CANNOT GO LOW ENOUGH ON THE DEW POINTS...AND THUS
THE HUMIDITY VALUES. RIGHT NOW...DEW POINTS ARE IN THE 30S WEST
RIVER...AND LOWER TO MID 40S IN SOUTH CENTRAL NEBRASKA. THEREFORE
LOOKING AT TRAJECTORIES EITHER FOR A SOUTHWEST WIND OR NORTHWEST
WIND...MADE SURE NOT TO GO ABOVE THOSE VALUES UPSTREAM.
WINDS WILL TAPER DOWN THIS EVENING AND TURN SOUTHERLY OVERNIGHT.
WITH THERMAL PROFILES CONTINUING TO WARM...IT WILL BE A MILD NIGHT
WITH LOWS IN THE MID 50S TO LOWER 60S.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 347 AM CDT MON MAY 13 2013
A STRONG SOUTHERLY FLOW SETS UP ON TUESDAY OUT AHEAD OF A SURFACE
TROUGH/FRONTAL BOUNDARY WHICH WILL PUSH ACROSS THE AREA IN THE
AFTERNOON. MOISTURE LOOKS TO BE MINIMAL WITH THIS SYSTEM...SO
EXPECTING IT TO BE A DRY FRONTAL PASSAGE. IT WILL BE A VERY MIXY DAY
WITH STRONG SOUTHWESTERLY WINDS OUT AHEAD OF THE FRONT...AND STRONG
NORTHWESTERLY WINDS BEHIND THE FRONT. MODELS AGAIN SEEM TO BE
OVERDOING DEWPOINTS ON TUESDAY...MOST LIKELY OVER DOING
EVAPOTRANSPIRATION...AND PROGGING DEWPOINTS WELL INTO THE 50S.
INSTEAD USED THE MIXDOWN TOOL WHICH YIELDED A BETTER ESTIMATION OF
DEWPOINTS...GENERALLY IN THE 40S...WITH SOME MOISTURE POOLING ALONG
THE FRONTAL BOUNDARY...THOUGH STILL MAY BE SLIGHTLY TOO HIGH ON
VALUES. IN ANY EVENT...WITH THE STRONG WINDS AND AFTERNOON RELATIVE
HUMIDITY VALUES FLOATING AROUND 20 TO 25 PERCENT...ISSUED A FIRE
WEATHER WATCH FOR THE ENTIRE CWA. AS HAS BEEN ADVERTISED OF
LATE...TUESDAY WILL GENERALLY BE THE WARMEST DAY OF THE WEEK WITH
ALL MODELS PROGGING 850 MB TEMPERATURES IN THE LOWER TO MID 20S C
OVER OUR EAST IN THE AFTERNOON...SO KEPT WITH LOWER TO MID 90S
THERE. WITH COLD AIR ADVECTION BEHIND THE FRONT...IT WILL BE LITTLE
COOLER TO THE WEST...WITH HIGHS IN THE MID AND UPPER 80S.
COOLER AIR WILL FILTER INTO THE REGION ON TUESDAY NIGHT WITH WINDS
DYING OFF OVERNIGHT. LOWS LOOKING TO BE IN THE UPPER 40S TO MID 50S.
WEDNESDAY AND WEDNESDAY NIGHT APPEAR TO BE PLEASANT WITH WEAK HIGH
PRESSURE BUILDING INTO THE REGION...WITH HIGHS IN THE 70S AND LOWS
IN THE 50S.
FARTHER INTO THE EXTENDED...THURSDAY THROUGH SUNDAY...LOOKS TO BE A
FAIRLY ACTIVE PERIOD WITH A NEARLY ZONAL UPPER LEVEL FLOW AT THE
START OF THE PERIOD...TRANSITIONING TO RIDGING ON FRIDAY AS A TROUGH
BEGINS TO LIFT OUT OF THE WESTERN U.S. AND INTO THE AREA BY LATE IN
THE WEEKEND. THINK MOST OF THURSDAY WILL BE DRY AND LITTLE WARMER AS
A SOUTHERLY FLOW BEGINS TO RETURN TO THE REGION WITH HIGHS IN THE
MID AND UPPER 70S. CANNOT RULE OUT SCATTERED THUNDERSTORMS FOR
THURSDAY NIGHT AND FRIDAY WITH INCREASING THETA E ADVECTION INTO THE
REGION...THOUGH WOULD BE HARD TO PIN POINT EXACT TIMING ON ANY
CONVECTIVE DEVELOPMENT THIS FAR OUT. A BETTER CHANCE OF CONVECTION
WOULD APPEAR TO BE LIKELY ON FRIDAY NIGHT AS LOW PRESSURE BEGINS TO
LIFT OUT OF THE ROCKIES. WITH CONVECTIVE PARAMETERS INCREASING
DURING THAT TIME FRAME...SEVERE STORMS WOULD SEEM MORE
LIKELY...THOUGH MODELS ARE DIFFERING A BIT ON THE PLACEMENT OF A
BOUNDARY LAYING SOMEWHERE CLOSE TO OUR AREA ON FRIDAY NIGHT AND
SATURDAY. THE UPPER LEVEL TROUGH SWINGS THROUGH THE REGION ON
SUNDAY...KEEPING A CHANCE OF CONVECTION...WITH COOLER AIR BEGINNING
TO PULL IN BEHIND THE SYSTEM.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 649 AM CDT MON MAY 13 2013
CONDITIONS WILL BE VFR TODAY AND TONIGHT. THERE COULD BE SOME
OCCASIONAL GUSTS TO AROUND 30 KNOTS IN NORTHWEST IOWA AND THE
SOUTHERN SECTION OF SOUTHWEST MN FROM ABOUT MIDDAY TO MID
AFTERNOON...WITH DIRECTIONS FROM THE SOUTHWEST. THEN THE WINDS
WILL SUBSIDE. LATE IN THE TAF PERIOD...KHON WAS CLOSE TO NON
CONVECTIVE LOW LEVEL WIND SHEAR. HOWEVER WINDS OFF THE SURFACE ARE
FORECAST TO BE ABOUT 25 TO 30 KNOTS NEAR THE TOP OF THE INVERSION.
SO LEFT OUT FOR NOW.
&&
.FIRE WEATHER...
ISSUED AT 1023 AM CDT MON MAY 13 2013
FIRE WEATHER WAS DISCUSSED EXTENSIVELY IN BOTH SHORT AND LONG TERM
SECTIONS EARLIER. MAIN PROBLEM WITH WINDS COMING UP A LITTLE
FASTER THAN EXPECTED IN OUR EAST IS A POSSIBLE NEED FOR A RED FLAG
WARNING FOR THIS AFTERNOON IN OUR EAST...EVEN THOUGH DEW POINTS
ARE COMING UP ABOUT AS WE HAD. WILL TRY TO ISSUE BY THE START OF
THE AFTERNOON IF WE DECIDE ONE IS NEEDED. OF COURSE WILL ALSO BE
CHECKING ON A POSSIBLE UPGRADE OF TUESDAY WATCH TO A WARNING.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR SDZ255>258.
MN...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR MNZ900.
IA...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR IAZ300-301.
NE...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR NEZ249.
&&
$$
UPDATE...
SHORT TERM...MJF/JM
LONG TERM...JM
AVIATION...MJF
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
700 AM CDT MON MAY 13 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 347 AM CDT MON MAY 13 2013
OBVIOUSLY THE MAIN CONCERN TODAY IS FIRE WEATHER. TEMPERATURES WILL
BE WELL ABOVE SEASONAL NORMALS AS A SURFACE TROUGH OF LOW PRESSURE
MOVES EASTWARD ACROSS OUR FORECAST AREA. THIS SURFACE TROUGH WILL
CAUSE A WIND SHIFT FROM THE SOUTHWEST TO NORTHWEST BEFORE IT STALLS
OUT LATE IN THE DAY IN NORTHWEST IOWA. GIVEN THE WINDS OFF THE
SURFACE AND MIXING POTENTIAL...OUR ZONES IN IOWA AROUND THE IOWA
GREAT LAKES AND STORM LAKE AREAS...AS WELL AS SOME OF THE SOUTHERN
SECTIONS IN SOUTHWEST MINNESOTA...WILL PUSH RED FLAG CRITERIA BUT
PROBABLY ONLY FOR A COUPLE OF HOURS. THIS IS BECAUSE BETWEEN 21Z AND
00Z...THE WINDS SHOULD DECREASE A FAIR AMOUNT IN THE AXIS OF THE
SURFACE TROUGH WHICH IS RIGHT IN THOSE AREAS. THEREFORE IT WILL BE A
BREEZY TO MODERATELY WINDY DAY IN THOSE AREAS...GOOD FOR A VERY HIGH
FIRE DANGER...BUT POSSIBLY JUST NOT QUITE THERE FOR A BONAFIDE RED
FLAG WARNING. THE SAME HOLDS TRUE FOR BEHIND THE SURFACE TROUGH...
WHICH IS ALONG AND WEST OF THE JAMES RIVER VALLEY. MINIMUM HUMIDITY
VALUES WILL LIKELY REALLY TANK IN THOSE ZONES TO LESS THAN 20
PERCENT. HOWEVER IN OUR WESTERN ZONES THIS AFTERNOON...SUSTAINED
NORTHWEST SURFACE WINDS WILL LIKELY STAY LESS THEN 20 MPH MUCH OF
THE TIME...WITH GUSTS FREQUENTLY AROUND 25 TO 27 MPH. SO AGAIN...
JUST A BIT BELOW RED FLAG CRITERIA...BUT CERTAINLY ELEVATED FIRE
DANGER. THE ONE THING THAT COULD REALLY ALTER THIS SCENARIO
SIGNIFICANTLY IS IF THE MIXED LAYER WINDS WHICH ARE FORECAST TO BE
AROUND 25 KNOTS IN OUR FORECAST AREA...BECOME STRONGER THEN
ANTICIPATED. IF THAT HAPPENS...WE COULD GO RED FLAG OVER MANY AREAS.
CONCERNING HUMIDITY...MUCH OF THE MODEL DEW POINT GUIDANCE IS WAY
TOO HIGH. PRIMARILY BLENDED THE REALLY DRY RAP MODEL DEW POINTS INTO
CONSENSUS SHORT. THIS SEEMED TO GIVE REASONABLE VALUES...AS IT SEEMS
THAT EACH DAY WE CANNOT GO LOW ENOUGH ON THE DEW POINTS...AND THUS
THE HUMIDITY VALUES. RIGHT NOW...DEW POINTS ARE IN THE 30S WEST
RIVER...AND LOWER TO MID 40S IN SOUTH CENTRAL NEBRASKA. THEREFORE
LOOKING AT TRAJECTORIES EITHER FOR A SOUTHWEST WIND OR NORTHWEST
WIND...MADE SURE NOT TO GO ABOVE THOSE VALUES UPSTREAM.
OBVIOUSLY THE MAIN CONCERN TODAY IS FIRE WEATHER. TEMPERATURES WILL
BE WELL ABOVE SEASONAL NORMALS AS A SURFACE TROUGH OF LOW PRESSURE
MOVES EASTWARD ACROSS OUR FORECAST AREA. THIS SURFACE TROUGH WILL
CAUSE A WIND SHIFT FROM THE SOUTHWEST TO NORTHWEST BEFORE IT STALLS
OUT LATE IN THE DAY IN NORTHWEST IOWA. GIVEN THE WINDS OFF THE
SURFACE AND MIXING POTENTIAL...OUR ZONES IN IOWA AROUND THE IOWA
GREAT LAKES AND STORM LAKE AREAS...AS WELL AS SOME OF THE SOUTHERN
SECTIONS IN SOUTHWEST MINNESOTA...WILL PUSH RED FLAG CRITERIA BUT
PROBABLY ONLY FOR A COUPLE OF HOURS. THIS IS BECAUSE BETWEEN 21Z AND
00Z...THE WINDS SHOULD DECREASE A FAIR AMOUNT IN THE AXIS OF THE
SURFACE TROUGH WHICH IS RIGHT IN THOSE AREAS. THEREFORE IT WILL BE A
BREEZY TO MODERATELY WINDY DAY IN THOSE AREAS...GOOD FOR A VERY HIGH
FIRE DANGER...BUT POSSIBLY JUST NOT QUITE THERE FOR A BONAFIDE RED
FLAG WARNING. THE SAME HOLDS TRUE FOR BEHIND THE SURFACE TROUGH...
WHICH IS ALONG AND WEST OF THE JAMES RIVER VALLEY. MINIMUM HUMIDITY
VALUES WILL LIKELY REALLY TANK IN THOSE ZONES TO LESS THAN 20
PERCENT. HOWEVER IN OUR WESTERN ZONES THIS AFTERNOON...SUSTAINED
NORTHWEST SURFACE WINDS WILL LIKELY STAY LESS THEN 20 MPH MUCH OF
THE TIME...WITH GUSTS FREQUENTLY AROUND 25 TO 27 MPH. SO AGAIN...
JUST A BIT BELOW RED FLAG CRITERIA...BUT CERTAINLY ELEVATED FIRE
DANGER. THE ONE THING THAT COULD REALLY ALTER THIS SCENARIO
SIGNIFICANTLY IS IF THE MIXED LAYER WINDS WHICH ARE FORECAST TO BE
AROUND 25 KNOTS IN OUR FORECAST AREA...BECOME STRONGER THEN
ANTICIPATED. IF THAT HAPPENS...WE COULD GO RED FLAG OVER MANY AREAS.
CONCERNING HUMIDITY...MUCH OF THE MODEL DEW POINT GUIDANCE IS WAY
TOO HIGH. PRIMARILY BLENDED THE REALLY DRY RAP MODEL DEW POINTS INTO
CONSENSUS SHORT. THIS SEEMED TO GIVE REASONABLE VALUES...AS IT SEEMS
THAT EACH DAY WE CANNOT GO LOW ENOUGH ON THE DEW POINTS...AND THUS
THE HUMIDITY VALUES. RIGHT NOW...DEW POINTS ARE IN THE 30S WEST
RIVER...AND LOWER TO MID 40S IN SOUTH CENTRAL NEBRASKA. THEREFORE
LOOKING AT TRAJECTORIES EITHER FOR A SOUTHWEST WIND OR NORTHWEST
WIND...MADE SURE NOT TO GO ABOVE THOSE VALUES UPSTREAM.
WINDS WILL TAPER DOWN THIS EVENING AND TURN SOUTHERLY OVERNIGHT.
WITH THERMAL PROFILES CONTINUING TO WARM...IT WILL BE A MILD NIGHT
WITH LOWS IN THE MID 50S TO LOWER 60S.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 347 AM CDT MON MAY 13 2013
A STRONG SOUTHERLY FLOW SETS UP ON TUESDAY OUT AHEAD OF A SURFACE
TROUGH/FRONTAL BOUNDARY WHICH WILL PUSH ACROSS THE AREA IN THE
AFTERNOON. MOISTURE LOOKS TO BE MINIMAL WITH THIS SYSTEM...SO
EXPECTING IT TO BE A DRY FRONTAL PASSAGE. IT WILL BE A VERY MIXY DAY
WITH STRONG SOUTHWESTERLY WINDS OUT AHEAD OF THE FRONT...AND STRONG
NORTHWESTERLY WINDS BEHIND THE FRONT. MODELS AGAIN SEEM TO BE
OVERDOING DEWPOINTS ON TUESDAY...MOST LIKELY OVER DOING
EVAPOTRANSPIRATION...AND PROGGING DEWPOINTS WELL INTO THE 50S.
INSTEAD USED THE MIXDOWN TOOL WHICH YIELDED A BETTER ESTIMATION OF
DEWPOINTS...GENERALLY IN THE 40S...WITH SOME MOISTURE POOLING ALONG
THE FRONTAL BOUNDARY...THOUGH STILL MAY BE SLIGHTLY TOO HIGH ON
VALUES. IN ANY EVENT...WITH THE STRONG WINDS AND AFTERNOON RELATIVE
HUMIDITY VALUES FLOATING AROUND 20 TO 25 PERCENT...ISSUED A FIRE
WEATHER WATCH FOR THE ENTIRE CWA. AS HAS BEEN ADVERTISED OF
LATE...TUESDAY WILL GENERALLY BE THE WARMEST DAY OF THE WEEK WITH
ALL MODELS PROGGING 850 MB TEMPERATURES IN THE LOWER TO MID 20S C
OVER OUR EAST IN THE AFTERNOON...SO KEPT WITH LOWER TO MID 90S
THERE. WITH COLD AIR ADVECTION BEHIND THE FRONT...IT WILL BE LITTLE
COOLER TO THE WEST...WITH HIGHS IN THE MID AND UPPER 80S.
COOLER AIR WILL FILTER INTO THE REGION ON TUESDAY NIGHT WITH WINDS
DYING OFF OVERNIGHT. LOWS LOOKING TO BE IN THE UPPER 40S TO MID 50S.
WEDNESDAY AND WEDNESDAY NIGHT APPEAR TO BE PLEASANT WITH WEAK HIGH
PRESSURE BUILDING INTO THE REGION...WITH HIGHS IN THE 70S AND LOWS
IN THE 50S.
FARTHER INTO THE EXTENDED...THURSDAY THROUGH SUNDAY...LOOKS TO BE A
FAIRLY ACTIVE PERIOD WITH A NEARLY ZONAL UPPER LEVEL FLOW AT THE
START OF THE PERIOD...TRANSITIONING TO RIDGING ON FRIDAY AS A TROUGH
BEGINS TO LIFT OUT OF THE WESTERN U.S. AND INTO THE AREA BY LATE IN
THE WEEKEND. THINK MOST OF THURSDAY WILL BE DRY AND LITTLE WARMER AS
A SOUTHERLY FLOW BEGINS TO RETURN TO THE REGION WITH HIGHS IN THE
MID AND UPPER 70S. CANNOT RULE OUT SCATTERED THUNDERSTORMS FOR
THURSDAY NIGHT AND FRIDAY WITH INCREASING THETA E ADVECTION INTO THE
REGION...THOUGH WOULD BE HARD TO PIN POINT EXACT TIMING ON ANY
CONVECTIVE DEVELOPMENT THIS FAR OUT. A BETTER CHANCE OF CONVECTION
WOULD APPEAR TO BE LIKELY ON FRIDAY NIGHT AS LOW PRESSURE BEGINS TO
LIFT OUT OF THE ROCKIES. WITH CONVECTIVE PARAMETERS INCREASING
DURING THAT TIME FRAME...SEVERE STORMS WOULD SEEM MORE
LIKELY...THOUGH MODELS ARE DIFFERING A BIT ON THE PLACEMENT OF A
BOUNDARY LAYING SOMEWHERE CLOSE TO OUR AREA ON FRIDAY NIGHT AND
SATURDAY. THE UPPER LEVEL TROUGH SWINGS THROUGH THE REGION ON
SUNDAY...KEEPING A CHANCE OF CONVECTION...WITH COOLER AIR BEGINNING
TO PULL IN BEHIND THE SYSTEM.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 649 AM CDT MON MAY 13 2013
CONDITIONS WILL BE VFR TODAY AND TONIGHT. THERE COULD BE SOME
OCCASIONAL GUSTS TO AROUND 30 KNOTS IN NORTHWEST IOWA AND THE
SOUTHERN SECTION OF SOUTHWEST MN FROM ABOUT MIDDAY TO MID
AFTERNOON...WITH DIRECTIONS FROM THE SOUTHWEST. THEN THE WINDS
WILL SUBSIDE. LATE IN THE TAF PERIOD...KHON WAS CLOSE TO NON
CONVECTIVE LOW LEVEL WIND SHEAR. HOWEVER WINDS OFF THE SURFACE ARE
FORECAST TO BE ABOUT 25 TO 30 KNOTS NEAR THE TOP OF THE INVERSION.
SO LEFT OUT FOR NOW.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR SDZ255>258.
MN...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR MNZ900.
IA...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR IAZ300-301.
NE...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR NEZ249.
&&
$$
SHORT TERM...MJF/JM
LONG TERM...JM
AVIATION...MJF
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
352 AM CDT MON MAY 13 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 347 AM CDT MON MAY 13 2013
OBVIOUSLY THE MAIN CONCERN TODAY IS FIRE WEATHER. TEMPERATURES WILL
BE WELL ABOVE SEASONAL NORMALS AS A SURFACE TROUGH OF LOW PRESSURE
MOVES EASTWARD ACROSS OUR FORECAST AREA. THIS SURFACE TROUGH WILL
CAUSE A WIND SHIFT FROM THE SOUTHWEST TO NORTHWEST BEFORE IT STALLS
OUT LATE IN THE DAY IN NORTHWEST IOWA. GIVEN THE WINDS OFF THE
SURFACE AND MIXING POTENTIAL...OUR ZONES IN IOWA AROUND THE IOWA
GREAT LAKES AND STORM LAKE AREAS...AS WELL AS SOME OF THE SOUTHERN
SECTIONS IN SOUTHWEST MINNESOTA...WILL PUSH RED FLAG CRITERIA BUT
PROBABLY ONLY FOR A COUPLE OF HOURS. THIS IS BECAUSE BETWEEN 21Z AND
00Z...THE WINDS SHOULD DECREASE A FAIR AMOUNT IN THE AXIS OF THE
SURFACE TROUGH WHICH IS RIGHT IN THOSE AREAS. THEREFORE IT WILL BE A
BREEZY TO MODERATELY WINDY DAY IN THOSE AREAS...GOOD FOR A VERY HIGH
FIRE DANGER...BUT POSSIBLY JUST NOT QUITE THERE FOR A BONAFIDE RED
FLAG WARNING. THE SAME HOLDS TRUE FOR BEHIND THE SURFACE TROUGH...
WHICH IS ALONG AND WEST OF THE JAMES RIVER VALLEY. MINIMUM HUMIDITY
VALUES WILL LIKELY REALLY TANK IN THOSE ZONES TO LESS THAN 20
PERCENT. HOWEVER IN OUR WESTERN ZONES THIS AFTERNOON...SUSTAINED
NORTHWEST SURFACE WINDS WILL LIKELY STAY LESS THEN 20 MPH MUCH OF
THE TIME...WITH GUSTS FREQUENTLY AROUND 25 TO 27 MPH. SO AGAIN...
JUST A BIT BELOW RED FLAG CRITERIA...BUT CERTAINLY ELEVATED FIRE
DANGER. THE ONE THING THAT COULD REALLY ALTER THIS SCENARIO
SIGNIFICANTLY IS IF THE MIXED LAYER WINDS WHICH ARE FORECAST TO BE
AROUND 25 KNOTS IN OUR FORECAST AREA...BECOME STRONGER THEN
ANTICIPATED. IF THAT HAPPENS...WE COULD GO RED FLAG OVER MANY AREAS.
CONCERNING HUMIDITY...MUCH OF THE MODEL DEW POINT GUIDANCE IS WAY
TOO HIGH. PRIMARILY BLENDED THE REALLY DRY RAP MODEL DEW POINTS INTO
CONSENSUS SHORT. THIS SEEMED TO GIVE REASONABLE VALUES...AS IT SEEMS
THAT EACH DAY WE CANNOT GO LOW ENOUGH ON THE DEW POINTS...AND THUS
THE HUMIDITY VALUES. RIGHT NOW...DEW POINTS ARE IN THE 30S WEST
RIVER...AND LOWER TO MID 40S IN SOUTH CENTRAL NEBRASKA. THEREFORE
LOOKING AT TRAJECTORIES EITHER FOR A SOUTHWEST WIND OR NORTHWEST
WIND...MADE SURE NOT TO GO ABOVE THOSE VALUES UPSTREAM.
OBVIOUSLY THE MAIN CONCERN TODAY IS FIRE WEATHER. TEMPERATURES WILL
BE WELL ABOVE SEASONAL NORMALS AS A SURFACE TROUGH OF LOW PRESSURE
MOVES EASTWARD ACROSS OUR FORECAST AREA. THIS SURFACE TROUGH WILL
CAUSE A WIND SHIFT FROM THE SOUTHWEST TO NORTHWEST BEFORE IT STALLS
OUT LATE IN THE DAY IN NORTHWEST IOWA. GIVEN THE WINDS OFF THE
SURFACE AND MIXING POTENTIAL...OUR ZONES IN IOWA AROUND THE IOWA
GREAT LAKES AND STORM LAKE AREAS...AS WELL AS SOME OF THE SOUTHERN
SECTIONS IN SOUTHWEST MINNESOTA...WILL PUSH RED FLAG CRITERIA BUT
PROBABLY ONLY FOR A COUPLE OF HOURS. THIS IS BECAUSE BETWEEN 21Z AND
00Z...THE WINDS SHOULD DECREASE A FAIR AMOUNT IN THE AXIS OF THE
SURFACE TROUGH WHICH IS RIGHT IN THOSE AREAS. THEREFORE IT WILL BE A
BREEZY TO MODERATELY WINDY DAY IN THOSE AREAS...GOOD FOR A VERY HIGH
FIRE DANGER...BUT POSSIBLY JUST NOT QUITE THERE FOR A BONAFIDE RED
FLAG WARNING. THE SAME HOLDS TRUE FOR BEHIND THE SURFACE TROUGH...
WHICH IS ALONG AND WEST OF THE JAMES RIVER VALLEY. MINIMUM HUMIDITY
VALUES WILL LIKELY REALLY TANK IN THOSE ZONES TO LESS THAN 20
PERCENT. HOWEVER IN OUR WESTERN ZONES THIS AFTERNOON...SUSTAINED
NORTHWEST SURFACE WINDS WILL LIKELY STAY LESS THEN 20 MPH MUCH OF
THE TIME...WITH GUSTS FREQUENTLY AROUND 25 TO 27 MPH. SO AGAIN...
JUST A BIT BELOW RED FLAG CRITERIA...BUT CERTAINLY ELEVATED FIRE
DANGER. THE ONE THING THAT COULD REALLY ALTER THIS SCENARIO
SIGNIFICANTLY IS IF THE MIXED LAYER WINDS WHICH ARE FORECAST TO BE
AROUND 25 KNOTS IN OUR FORECAST AREA...BECOME STRONGER THEN
ANTICIPATED. IF THAT HAPPENS...WE COULD GO RED FLAG OVER MANY AREAS.
CONCERNING HUMIDITY...MUCH OF THE MODEL DEW POINT GUIDANCE IS WAY
TOO HIGH. PRIMARILY BLENDED THE REALLY DRY RAP MODEL DEW POINTS INTO
CONSENSUS SHORT. THIS SEEMED TO GIVE REASONABLE VALUES...AS IT SEEMS
THAT EACH DAY WE CANNOT GO LOW ENOUGH ON THE DEW POINTS...AND THUS
THE HUMIDITY VALUES. RIGHT NOW...DEW POINTS ARE IN THE 30S WEST
RIVER...AND LOWER TO MID 40S IN SOUTH CENTRAL NEBRASKA. THEREFORE
LOOKING AT TRAJECTORIES EITHER FOR A SOUTHWEST WIND OR NORTHWEST
WIND...MADE SURE NOT TO GO ABOVE THOSE VALUES UPSTREAM.
WINDS WILL TAPER DOWN THIS EVENING AND TURN SOUTHERLY OVERNIGHT.
WITH THERMAL PROFILES CONTINUING TO WARM...IT WILL BE A MILD NIGHT
WITH LOWS IN THE MID 50S TO LOWER 60S.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 347 AM CDT MON MAY 13 2013
A STRONG SOUTHERLY FLOW SETS UP ON TUESDAY OUT AHEAD OF A SURFACE
TROUGH/FRONTAL BOUNDARY WHICH WILL PUSH ACROSS THE AREA IN THE
AFTERNOON. MOISTURE LOOKS TO BE MINIMAL WITH THIS SYSTEM...SO
EXPECTING IT TO BE A DRY FRONTAL PASSAGE. IT WILL BE A VERY MIXY DAY
WITH STRONG SOUTHWESTERLY WINDS OUT AHEAD OF THE FRONT...AND STRONG
NORTHWESTERLY WINDS BEHIND THE FRONT. MODELS AGAIN SEEM TO BE
OVERDOING DEWPOINTS ON TUESDAY...MOST LIKELY OVER DOING
EVAPOTRANSPIRATION...AND PROGGING DEWPOINTS WELL INTO THE 50S.
INSTEAD USED THE MIXDOWN TOOL WHICH YIELDED A BETTER ESTIMATION OF
DEWPOINTS...GENERALLY IN THE 40S...WITH SOME MOISTURE POOLING ALONG
THE FRONTAL BOUNDARY...THOUGH STILL MAY BE SLIGHTLY TOO HIGH ON
VALUES. IN ANY EVENT...WITH THE STRONG WINDS AND AFTERNOON RELATIVE
HUMIDITY VALUES FLOATING AROUND 20 TO 25 PERCENT...ISSUED A FIRE
WEATHER WATCH FOR THE ENTIRE CWA. AS HAS BEEN ADVERTISED OF
LATE...TUESDAY WILL GENERALLY BE THE WARMEST DAY OF THE WEEK WITH
ALL MODELS PROGGING 850 MB TEMPERATURES IN THE LOWER TO MID 20S C
OVER OUR EAST IN THE AFTERNOON...SO KEPT WITH LOWER TO MID 90S
THERE. WITH COLD AIR ADVECTION BEHIND THE FRONT...IT WILL BE LITTLE
COOLER TO THE WEST...WITH HIGHS IN THE MID AND UPPER 80S.
COOLER AIR WILL FILTER INTO THE REGION ON TUESDAY NIGHT WITH WINDS
DYING OFF OVERNIGHT. LOWS LOOKING TO BE IN THE UPPER 40S TO MID 50S.
WEDNESDAY AND WEDNESDAY NIGHT APPEAR TO BE PLEASANT WITH WEAK HIGH
PRESSURE BUILDING INTO THE REGION...WITH HIGHS IN THE 70S AND LOWS
IN THE 50S.
FARTHER INTO THE EXTENDED...THURSDAY THROUGH SUNDAY...LOOKS TO BE A
FAIRLY ACTIVE PERIOD WITH A NEARLY ZONAL UPPER LEVEL FLOW AT THE
START OF THE PERIOD...TRANSITIONING TO RIDGING ON FRIDAY AS A TROUGH
BEGINS TO LIFT OUT OF THE WESTERN U.S. AND INTO THE AREA BY LATE IN
THE WEEKEND. THINK MOST OF THURSDAY WILL BE DRY AND LITTLE WARMER AS
A SOUTHERLY FLOW BEGINS TO RETURN TO THE REGION WITH HIGHS IN THE
MID AND UPPER 70S. CANNOT RULE OUT SCATTERED THUNDERSTORMS FOR
THURSDAY NIGHT AND FRIDAY WITH INCREASING THETA E ADVECTION INTO THE
REGION...THOUGH WOULD BE HARD TO PIN POINT EXACT TIMING ON ANY
CONVECTIVE DEVELOPMENT THIS FAR OUT. A BETTER CHANCE OF CONVECTION
WOULD APPEAR TO BE LIKELY ON FRIDAY NIGHT AS LOW PRESSURE BEGINS TO
LIFT OUT OF THE ROCKIES. WITH CONVECTIVE PARAMETERS INCREASING
DURING THAT TIME FRAME...SEVERE STORMS WOULD SEEM MORE
LIKELY...THOUGH MODELS ARE DIFFERING A BIT ON THE PLACEMENT OF A
BOUNDARY LAYING SOMEWHERE CLOSE TO OUR AREA ON FRIDAY NIGHT AND
SATURDAY. THE UPPER LEVEL TROUGH SWINGS THROUGH THE REGION ON
SUNDAY...KEEPING A CHANCE OF CONVECTION...WITH COOLER AIR BEGINNING
TO PULL IN BEHIND THE SYSTEM.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1035 PM CDT SUN MAY 12 2013
VFR CONDITIONS THROUGH THE TAF PERIOD. WINDS WILL BE LIGHT AND
VARIABLE OVERNIGHT THEN INCREASE FROM THE SOUTH LATE TONIGHT THROUGH
MONDAY. AFTER 15Z...WINDS WILL INCREASE AROUND 15 KT WITH GUSTS TO 25
KT AND TURN MORE WESTERLY IN THE AFTERNOON.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR SDZ255>258.
MN...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR MNZ900.
IA...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR IAZ300-301.
NE...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR NEZ249.
&&
$$
SHORT TERM...MJF/JM
LONG TERM...JM
AVIATION...
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1106 PM MDT SUN MAY 12 2013
.SHORT TERM...THIS EVENING THROUGH MONDAY NIGHT
ISSUED AT 255 PM MDT SUN MAY 12 2013
MASSIVE WESTERN CONUS UPPER RIDGE CONTINUES TO PUSH
EAST WITH DEEP LAYER THETA-E RIDGING ONGOING. LEE SIDE TROUGH
WILL ADVECT EAST AWAY FROM THE ROCKIES ON THE LEADING EDGE OF
UPPER LEVEL HEIGHT RISES...WITH A STRONG UPPER LEVEL TROUGH
EXPECTED TO ADVANCE INTO THE NORTHERN PLAINS MONDAY
NIGHT...SUPPORTING ANOTHER MORE PRONOUNCED LL TROUGH INTO THE
REGION. OVERALL...MAINLY DRY WEATHER EXPECTED...SAVE FOR PORTIONS
OF THE BLACK HILLS WHERE LL THETA-E ADV COUPLED WITH STEEPENING
MID LEVEL LAPSE RATES AND LOCAL OROGRAPHIC CONVERGENCE MAY SUPPORT
ISOLD SHRA/TS LATE THIS AFTERNOON/EARLY EVENING AND AGAIN MONDAY
AFTERNOON/EVENING. OTHERWISE...A SIG WARM NOSE ASSOCIATED WITH THE
ADVANCING RIDGE IS EXPECTED TO KEEP CONVECTION AT BAY ELSEWHERE.
LATE THIS AFTERNOON/TONIGHT...REMOVED LOW POPS OVER THE
CENTRAL/SOUTHERN BH. NEARLY ALL HIRES MODELS DO NOT GENERATE ANY
CONVECTION...WITH THE NAM BEING THE ONLY MODEL/OUTLIER THAT DOES.
LATEST RAP BUFR PROGS INDICATE MID LEVEL WARMING IS STRONGER/FASTER
THAN PREVIOUS INDICATIONS...WITH A DOWNTREND IN CU NOTED IN SAT
TRENDS. OTHERWISE...A WARM NIGHT EXPECTED WITH LOWS IN THE 50S AT
MANY PLACES. THERE IS A SMALL POTENTIAL FOR AN ELEVATED SHOWER
ACROSS THE FAR NORTH GIVEN THETA-E ADV AT THE BASE OVER THE GROWING
WARM NOSE WITH NEGATIVE SW INDICES. HOWEVER...GIVEN THE LOW
POTENTIAL HAVE LEFT OUT AND WILL LET THE NEXT SHIFT ASSESS.
MONDAY...LEAD LL TROUGH WILL ADVECT EAST ACROSS THE AREA IN THE
MORNING...WITH ONGOING DEEP LAYER WAA. INCREASED LL MOISTURE MAY BE
SUFFICIENT ENOUGH TO GENERATE ISOLD CONVECTION OVER THE BH...ESP
WITH A WEAK MESO LOW AS INDICATED IN THE NAM. RETAINED SLIGHT CHANCE
POPS THERE. OTHERWISE...VERY WARM CONDITIONS EXPECTED WITH LOW TO
MID 90S OVER THE SD PLAINS...COOLER WEST. CURRENT FORECAST TEMPS
SURPASSES THE RECORD OF 92 AT THE RAPID CITY AIRPORT...NEARING THE
DOWNTOWN RECORD OF 94. A VERY WARM NIGHT IS IN STORE FOR MONDAY
NIGHT...WITH LOWS IN THE 60S AT MANY PLACES GIVEN ONGOING SFC
PRESSURE FALLS PER THE ADVANCING DEEP NORTHERN STREAM UPPER IMPULSE.
THIS WILL SUPPORT A MIXED BL WITH GUSTY WINDS POTENTIALLY AT MANY
LOCATIONS...ESP OVER THE NORTHERN BH FOOTHILLS...GIVEN A NEAR 5 MB
SFC PRESSURE DIFFERENTIAL FROM THE BH TO THE PLAINS. RECORD HIGH
MIN/S MAY BE SET AT RAPID CITY.
&&
.LONG TERM...TUESDAY THROUGH SUNDAY
ISSUED AT 255 PM MDT SUN MAY 12 2013
UPPER LEVEL RIDGE BREAKS DOWN BY TUESDAY MORNING AS A SURFACE LOW
PASSES TO THE NORTH AND A STRONG COLD FRONT SLIDES QUICKLY ACROSS
THE FORECAST AREA DURING THE MORNING. STRONG NORTHWEST WINDS CAN BE
EXPECTED ACROSS THE NORTHWEST AND WEST CENTRAL SOUTH DAKOTA PLAINS
BEHIND THE FRONT. THE STRONGEST WINDS LOOK TO BE NEAR THE ND BORDER.
HAVE DECIDED TO ISSUE A HIGH WIND WATCH FOR HARDING AND PERKINS
COUNTIES...WHERE SUSTAINED WINDS OF 40 MPH OR MORE LOOK POSSIBLE...
ESPECIALLY DURING THE LATE MORNING AND EARLY AFTERNOON HOURS. HIGH
TEMPERATURES WILL RANGE FROM THE LOWER 70S OVER FAR NORTHWESTERN SD
AND PORTIONS OF NORTHEASTERN WY TO THE UPPER 80S ACROSS SOUTH
CENTRAL SD. DEPENDING ON THE EXACT TIMING OF THE FRONT AND HOW
QUICKLY THE DRIER AIR PUSHES IN BEHIND THE FRONT...THERE IS SOME
POTENTIAL FOR CRITICAL FIRE WEATHER CONDITIONS TO DEVELOP ACROSS
PORTIONS OF THE SD PLAINS TUESDAY AFTERNOON. WILL LET LATER SHIFTS
HAVE A LOOK AT UPDATED MODEL DATA FOR THIS POTENTIAL AND WHETHER A
FIRE WX WATCH MAY BE NEEDED.
MORE SEASONABLE TEMPS ARE EXPECTED FOR THE REMAINDER OF THE
WEEK...THOUGH STILL ABOVE AVERAGE...AS AREA REMAINS UNDER ZONAL
FLOW. WEAK DISTURBANCES WITHIN THIS FLOW WILL BRING SOME CHANCES FOR
MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS LATE IN THE
WEEK...WITH CHANCES LIKELY INCREASING BY THE WEEKEND. LATEST GFS AND
ECMWF BOTH CONTINUE TO SHOW A STRONGER UPPER TROF IMPACTING THE
REGION FROM LATE FRIDAY THROUGH THE WEEKEND...BRINGING THE POTENTIAL
FOR MORE WIDESPREAD PCPN AND OUR FIRST SEVERE WX OF THE SEASON.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1105 PM MDT SUN MAY 12 2013
VFR CONDITIONS ARE EXPECTED THROUGH MONDAY EVENING. OTHERWISE...A
FEW STORMS MAY FORM OVER THE BLKHLS MONDAY AFTN.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...HIGH WIND WATCH FROM TUESDAY MORNING THROUGH TUESDAY AFTERNOON
FOR SDZ001-002.
WY...NONE.
&&
$$
SHORT TERM...JC
LONG TERM...26
AVIATION...BUNKERS
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
633 PM CDT TUE MAY 14 2013
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...DUAL CLOUDS DECKS CONTINUE ACROSS SOUTH TEXAS...WITH
LOWER DECK FROM 3000 TO 4000 FEET DRIFTING TO THE NW AND MIDLEVEL
DECK RACING OFF TO THE NE. CLOUD DECK WILL REMAIN THROUGH THE
NIGHT...WITH LOWER DECK SLOWLY LOWERING TO AROUND 2000 BY MORNING.
PROB30 RAIN CHANCES STARTING AT MIDNIGHT AS THE NEXT SYSTEM MOVES
INTO THE REGION...WITH SHOWERS ALREADY SHOWING UP ON RADAR TO THE
SW. OCCASIONAL RAINFALL WILL CONTINUE TOMORROW...MAINLY BEFORE
NOON. RAIN WILL REMAIN LIGHT...WITH ISOLATED LIGHTNING STRIKES
POSSIBLE.
&&
.PREV DISCUSSION... /ISSUED 155 PM CDT TUE MAY 14 2013/
SHORT TERM.../TONIGHT THROUGH WEDNESDAY NIGHT/...EVEN THOUGH THE
LATEST RUC13 MODEL RUNS CONTINUE TO SHOW SHOWERS DEVELOPING
ACROSS THE CWA THIS AFTERNOON...RADAR AND SATELLITE IMAGES INDICATE
NOT MUCH IN THE WAY OF RAIN DEVELOPING AS OF YET. SURFACE
INSTABILITY IS MARGINAL ACROSS THE RIO GRANDE VALLEY AND THE CLOUD
COVER MAY BE INHIBITING THE INSTABILITY. IN ADDITION...WATER VAPOR
SAT IMAGES AND NAM80 500MB VORTICITY ANALYSIS INDICATE NEGATIVE VORT
CENTER JUST TO THE WEST OF THE AREA. CURRENT FORECAST THINKING IS
THAT AS THE 500MB LOW ACROSS NORTHWEST MEXICO IS KICKED EASTWARD
WITH THE SHORTWAVE TROUGH MOVING INTO SOUTHERN CALIFORNIA...SHOWERS
AND THUNDERSTORMS WILL DEVELOP LATER THIS AFTERNOON INTO THIS
EVENING ACROSS THE MEXICAN PLATEAU AND MOVE EASTWARD INTO THE
WESTERN PORTIONS OF THE CWA TONIGHT INTO EARLY WEDNESDAY. WITH THAT
SAID...WILL ADJUST TIMING OF POPS TONIGHT INTO WED NIGHT AND KEEP AT
LEAST A CHANCE OF RAIN ACROSS MOST OF THE AREA THROUGH WED
AFTERNOON. RAIN CHANCES SHOULD DIMINISH WED AFTERNOON INTO WED
EVENING AS SUBSIDENCE WILL INCREASE ACROSS SOUTHWEST TX AS THE UPPER
LEVEL LOW MOVES ACROSS NORTHWEST TX WEDNESDAY.
LONG TERM.../THURSDAY THROUGH TUESDAY NIGHT/...
LOW PRESSURE SYSTEM OVER BAJA CA WILL QUICKLY MOVE ACROSS SOUTH
CENTRAL TEXAS WED INTO THU WITH SURFACE HIGH PRESSURE TO THE EAST
MOVING SOUTHWARD OVER THE GULF WATERS AS IT INTERACTS WITH THE LOW
PRESSURE OVER WEST TEXAS. AS THIS SYSTEM LIFTS TO THE NORTHEAST...
THE SURFACE WINDS WILL RETURN TO THE SOUTHEAST ACROSS SOUTH TEXAS
AND THE GRADIENT IN RETURN WILL STRENGTHEN. EXPECT BREEZE CONDITIONS
BETWEEN 20 TO 25 MPH THURSDAY AFTERNOON. MOST OF THE MOISTURE SEEN
IN THE LAST FEW DAYS WILL DROP DRAMATICALLY ACROSS THE AREA WITH THE
BUFF SOUNDING NEAR KBRO SHOWING THE INFILTRATION OF THE DRIER AIR IN
THE UPPER AND MID LEVEL OF THE ATMOSPHERE AND A DROP IN THE PWAT
VALUES TO 1.34 INCHES AND INTO 1.10 INCHES TOWARDS THE WEST. THE
DRIER AIR MASS FROM THE RIDGE BUILDING ACROSS THE WESTERN PLAINS
WILL SET UP THAT DRIER AND WARM PATTERN FOR MOST OF THE LONG TERM
FORECAST. HIGH TEMPERATURES THURSDAY THROUGH SUNDAY WILL BE WARM AND
HUMID REACHING THE MID TO UPPER 90S THROUGH THE WEEK. ANOTHER TROUGH
DIGS SOUTHWARD ALONG BAJA CALIFORNIA AND SWING NORTHEASTWARD INTO
THE CENTRAL PLAINS SATURDAY AND SUNDAY. THE MAIN IMPACT WITH THIS
SYSTEM FOR SOUTH TEXAS WILL BE THE SE WINDS AND THE ABUNDANT WARM
TEMPERATURES ACROSS THE CWA WITH NO CONVECTION AS THE SYSTEM REMAINS
NORTH OF THE CWA. EXPECT SURFACE GRADIENT TO INCREASE WITH BREEZE TO
CONDITIONS THIS WEEKEND.
NEXT WEEK...THE TROUGH WILL CONTINUE TO MOVE NORTHEAST AND STRENGTHEN
ITS SURFACE TROUGH OVER NORTH CENTRAL PLAINS. THIS WILL CONTINUE TO
KEEP THE AREA UNDER SOUTHEAST WINDS ACROSS THE CWA. BY TUESDAY...THE
HIGH PRESSURE ALOFT BUILDS FROM THE SOUTH AND A VERY WEAK GRADIENT
AT THE SURFACE RETURNS. LOW TEMPERATURES FOR MUCH OF THE LONG TERM
FORECAST REMAIN IN THE MID 70S ACROSS THE AREA.
MARINE...TONIGHT THROUGH WEDNESDAY NIGHT...SEAS WERE NEAR 4 FEET WITH
SOUTHEAST WINDS NEAR 10 KNOTS AT BUOY020 EARLY THIS AFTERNOON. WINDS
WILL INCREASE ACROSS THE COASTAL WATERS TONIGHT AS THE PRESSURE
GRADIENT INCREASES ACROSS THE WESTERN GULF OF MEXICO. MODERATE TO
STRONG SOUTHEAST WINDS WILL PREVAIL TONIGHT WITH SCEC CONDITIONS
LIKELY OFFSHORE. THE SCEC CONDITIONS WILL PERSIST WEDNESDAY INTO WED
NIGHT...ESPECIALLY OFFSHORE...AS THE PRESSURE GRADIENT REMAINS
STRONG ACROSS THE LOWER TEXAS COAST.
THURSDAY THROUGH TUESDAY...
THE UPPER LEVEL SYSTEM OVER THE BAJA CA WILL FINALLY BEGIN TO MOVE
NORTHEAST WEDNESDAY INTO THURSDAY LIMITING THE AREA OF ANY
CONVECTION. THE SURFACE HIGH PRESSURE OVER THE SOUTHEAST PLAINS WILL
BEGIN TO SHIFT SOUTH OVER THE GULF WATERS SHIFTING WINDS ACROSS THE
GULF TOWARDS THE SE. WINDS WILL INCREASE THURSDAY AFTERNOON WITH
POSSIBLE SCA FOR MUCH OF THE DAY AND EARLY EVENING AS WINDS INCREASE.
THIS SE FLOW WILL PREVAIL FOR MUCH OF THE LONG TERM FORECAST BUT WILL
WEAKEN BY NEXT WEEK. SEAS WILL BE BETWEEN 4 TO 5 FEET OVER THE GULF
WATERS AS THERE WILL BE A LONG DURATION FETCH OVER THE GULF. THE UPPER
AND LOWER FLOW WILL WEAKEN AND KEEP THE WAVE HEIGHT 5 FEET OR LESS.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WWW.WEATHER.GOV/BROWNSVILLE
64
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1029 PM CDT TUE MAY 14 2013
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...TONIGHT
ISSUED AT 327 PM CDT TUE MAY 14 2013
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A REMNANT
NOCTURNAL MCS DIMINISHING ACROSS NORTHERN AND CENTRAL WISCONSIN
EARLY THIS AFTERNOON AFTER IT PRODUCED LIGHT SHOWERS OVER PARTS OF
THE AREA. AT THE SURFACE...A WARM FRONT EXTENDS FROM AN AREA OF LOW
PRESSURE OVER SOUTH-CENTRAL MINNESOTA TO NORTHEAST ILLINOIS. AND A
COLD FRONT ALSO EXTENDS FROM THAT SURFACE LOW SOUTHWEST TO THE
PANHANDLE OF NEBRASKA. TEMPERATURES TO THE SOUTHWEST OF THE WARM
FRONT ARE IN THE UPPER 80S TO 100 DEGREES...BUT STILL PLENTY OF 70S
TO THE NORTH OF THE BOUNDARY. CONVECTION ALONG EITHER BOUNDARY HAS
FAILED TO DEVELOP SO FAR. THE LATEST MESOANALYSIS SUGGESTS SB CIN
HAS BEEN ERODING OVER NE IOWA WHICH APPEARS TO BE THE MOSTLY LIKELY
LOCATION OF THUNDERSTORM DEVELOPMENT LATER THIS AFTERNOON. WITH
TEMPS EXPECTED TO TOP OUT ONLY IN THE 70S TO LOWER 80S ACROSS OUR
REGION THIS AFTERNOON...HAVING A HARD TIME SEEING ANY THUNDERSTORM
DEVELOPMENT IN OUR AREA...ESPECIALLY SINCE THERE IS NO SURFACE BASED
NOR MOST UNSTABLE CAPE AS OF YET...AND DEWPOINTS ARE IN THE LOWER
40S. WILL CONSEQUENTLY REMOVE ANY THUNDERSTORM CHANCES FOR THE REST
OF THE AFTERNOON. AS THE LOW MOVES ACROSS THE REGION
TONIGHT...SMALL PRECIP CHANCES ARE THE MAIN FORECAST CONCERN.
TONIGHT...WEAK LOW PRESSURE WILL MOVE FROM FAR NW WISCONSIN ACROSS
THE UPPER PENINSULA THIS EVENING. AS THIS OCCURS...AN 850MB WARM
FRONT WILL LIFT ACROSS NE WISCONSIN EARLY IN THE EVENING WHILE THE
COLD FRONT WILL SWEEP FROM NW TO SE ACROSS THE STATE MID TO LATE
EVENING. DESPITE THE WARM SECTOR REACHING INTO CENTRAL AND
EAST-CENTRAL WISCONSIN THIS EVENING...12Z SOUNDINGS FROM MPX AND DVN
AND PROGGED SOUNDINGS ALL INDICATE AMPLE DRY AIR BELOW 600 AND
700MB. ONLY SB CAPES EXISTING ACROSS THE REGION CURRENTLY ARE OVER
SW MN AND IOWA WHERE TEMPS RANGE FROM THE UPPER 80S TO THE UPPER
90S. NOT GOING TO COME CLOSE TO REACHING THOSE READINGS THIS
EVENING...SO THE POSSIBILITY OF STORMS DEVELOPING WITHIN THE WARM
SECTOR SEEMS TOO LOW TO MENTION IN THE FORECAST. IF STORMS WERE TO
DEVELOP...THE BEST CHANCES APPEAR TO BE OVER FAR N-C TO FAR NE
WISCONSIN EARLY TO MID EVENING DUE TO SOME INDICATIONS FROM THE RUC
OF THE NOSE OF THE LLJ POINTED IN THAT DIRECTION. IN ADDITION...THERE
IS SOME ELEVATED CAPE IN THE 850-800MB LAYER AROUND 850 J/KG AND
THAT REGION WOULD BE CLOSER TO THE EDGE OF THE MID-LEVEL CAP.
CAPPING WILL REMAIN TOUGH TO OVERCOME...SINCE BUFKIT SOUNDINGS
INDICATE ELEVATED CIN UPWARDS OF 150 J/KG. WILL LEAVE AN ISOLATED
STORM IN THE FORECAST FOR THIS REGION TONIGHT...BUT
ADMITTEDLY...CHANCES ARE QUITE SMALL. IF STORMS DO FIRE...STRONG
SHEAR WOULD SUPPORT ORGANIZATION THAT COULD LEAD TO HAIL AND STRONG
GUSTY WINDS. THE THREAT OF ISOLATED STORMS WILL DEPART LATE THIS
EVENING AND SKIES WILL BECOME CLEAR OVERNIGHT. WARM EVENING TEMPS
WILL FALL INTO THE 50S FOR LOWS TONIGHT.
.LONG TERM...WEDNESDAY THROUGH TUESDAY
ISSUED AT 327 PM CDT TUE MAY 14 2013
MAIN FCST CONCERNS INCLUDE FIRE WEATHER POTENTIAL ON WEDS/THURS...THEN
PCPN TRENDS FOR THE END OF THIS WEEK AND EARLY NEXT WEEK.
A VERY DRY AIR MASS WILL RESIDE OVER THE REGION FROM WEDNESDAY INTO
THURSDAY...WITH DEEP MIXING ALLOWING TEMPERATURES TO WARM NICELY...
AND ALSO CAUSING DEW POINTS TO PLUMMET DURING THE AFTERNOONS. HIGH
TEMPERATURES WILL BE WELL INTO THE 70S BOTH DAYS.
MODELS AGREE ON A GRADUAL RETURN OF PCPN CHANCES FROM THE WEST LATE
THURSDAY NIGHT AND INTO THE WEEKEND. THE LATEST TRENDS DON`T SUPPORT
AS MUCH OF A WASHOUT FOR THE WEEKEND AS WAS PREVIOUSLY SUSPECTED...
SO POPS HAVE BEEN LOWERED A BIT AND TEMPERATURES ARE EXPECTED TO BE
A LITTLE WARMER. RIGHT NOW...THE GREATEST THREAT OF SIGNIFICANT PCPN
APPEARS TO BE DURING THE SUNDAY NIGHT THROUGH MONDAY NIGHT TIME FRAME...
AS A LOW PRESSURE SYSTEM AND ASSOCIATED FRONTAL SYSTEM MOVES THROUGH.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1028 PM CDT TUE MAY 14 2013
MAINLY VFR CONDITIONS TO PREVAIL TONIGHT INTO
WEDNESDAY. LLWS CONDITIONS OVERNIGHT WITH STRONG NW WINDS TO 40
KTS BEFORE SUBSIDING IN THE MORNING. POSSIBLE SOME SMOKE FROM A
FOREST FIRE OVER FAR NORTHWEST WISCONSIN MAY REDUCE VSBYS
TO MVFR CONDITIONS DOWNSTREAM IN RHI OR AUW THIS MORNING.
&&
.FIRE WEATHER...
ISSUED AT 327 PM CDT TUE MAY 14 2013
TEMPERATURES IN THE 70S AND MINIMUM RELATIVE HUMIDITIES OF 20 TO 25
PERCENT IN THE SANDY SOIL AREAS CAN BE EXPECTED ON WEDS AND THURS.
NORTHWEST WINDS WILL GUST TO AROUND 30 MPH IN FAR NE WI ON WEDNESDAY
AFTERNOON...SETTING THE STAGE FOR A CRITICAL FIRE WEATHER DAY. A
FIRE WEATHER WATCH WILL BE ISSUED FOR FAR NE WI FROM NOON THROUGH
7 PM ON WEDNESDAY. WINDS WILL NOT BE AS STRONG ON THURSDAY...SO
HEADLINES SHOULD NOT BE NEEDED THEN.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM WEDNESDAY AFTERNOON THROUGH WEDNESDAY
EVENING FOR WIZ012-013-073.
&&
$$
SHORT TERM.....MPC
LONG TERM......KIECKBUSCH
AVIATION.......TDH
FIRE WEATHER...KIECKBUSCH
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
515 PM CDT MON MAY 13 2013
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND TUESDAY
ISSUED AT 233 PM CDT MON MAY 13 2013
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW HIGH PRESSURE
CENTERED OVER THE CENTRAL GREAT LAKES AND A WARM FRONT EXTENDING
SOUTH ACROSS THE GREAT PLAINS. LEADING EDGE OF THE WARM/MOIST AIR
ALOFT IS PRODUCING A NARROW BAND OF LIGHT RAIN ALONG THE WI/MN
BORDER THIS AFTERNOON...WHICH IS MEASURING A HUNDREDTH OR TWO
ACCORDING TO THE OBS. BAND OF LIGHT RAIN ALONG THIS 295-300K
MOISTURE ADVECTION WILL PUSH INTO CENTRAL WISCONSIN AROUND
5PM...DESPITE VERY DRY AIR PRESENTLY AT THE SURFACE. WEST OF THE
WARM FRONT...TEMPERATURES ARE MAINLY IN THE 80S AND A COUPLE 90
DEGREE READINGS ARE OUT THERE AS WELL. THE MAIN FORECAST CONCERNS
ARE TIMING OF THE PRECIP LATER THIS AFTERNOON INTO THIS
EVENING...FOLLOWED BY TEMPS AND SMALL THUNDER CHANCES TOMORROW.
TONIGHT...295-300K MOISTURE ADVECTION WILL PUSH A BAND OF LIGHT RAIN
ACROSS THE AREA LATER THIS AFTERNOON AND THROUGH THE EVENING.
MID-LEVEL LAPSE RATES ARE POOR AND SURFACE HUMIDITIES ARE IN THE
20S...SO SHOWERS SHOULD NOT AMOUNT TO MUCH. BUT OBS UPSTREAM
INDICATE A HUNDREDTH OR TWO OF ACCUM...SO WILL SHOW THIS IN THE
FORECAST AND RAISE POPS INTO THE LIKELY RANGE. THIS BAND WILL EXIT
LATE THIS EVENING...BUT A SECONDARY SURGE OF MOISTURE MAY CAUSE
ADDITIONAL REDEVELOPMENT OF SHOWERS OVER THE EASTERN HALF OR THIRD
OF THE FORECAST AREA AFTER MIDNIGHT. THINK PRECIP CHANCES WILL
LIKELY BE OVER BY THE START OF THE MORNING COMMUTE WHILE SKIES WILL
BE CLEARING FROM WEST TO EAST AT THE SAME TIME. PLENTY OF CLOUDS
AND A LIGHT SE WIND WILL KEEP TEMPS CONSIDERABLY WARMER THAN LAST
NIGHT AND WILL GO WITH LOWS IN THE LOW TO MID 40S.
TUESDAY...ELEVATED WARM FRONT WILL BE SHIFTING ACROSS LAKE MICHIGAN
EARLY TUESDAY MORNING...WHICH WILL RESULT IN CLEARING SKIES ACROSS
EASTERN WISCONSIN EARLY ON. EVEN THOUGH WILL LIKELY SEE CIRRUS
OVERHEAD...MODELS FORECAST VERY DRY AIR ARRIVING IN THE LOW TO MID
LEVELS SO DO NOT SEE A THREAT OF PRECIP THROUGH MID-AFTERNOON. BY
MID TO LATE AFTERNOON...LOW PRESSURE WILL BE ACROSS CENTRAL
MINNESOTA...AND A 850MB LLJ WILL PUSH A WARM FRONT INTO SW
WISCONSIN. ORDINARILY...MASS CONVERGENCE ON THE NOSE OF THE LLJ
WOULD BE CONDUCIVE FOR THUNDERSTORMS...ESPECIALLY WITH MID-LEVEL
LAPSE RATES AROUND 8 C/KM....BUT THE INCOMING AIRMASS IS SO DRY
BELOW 600MB...AND EXPECT SURFACE DEWPOINTS TO FALL THROUGH THE
AFTERNOON. THIS RESULTS IN PROGGED CONVECTIVE INHIBITION OF 200-300
J/KG LATE IN THE AFTERNOON WHEN THE FORCING ARRIVES...WHICH LOOKS
AWFULLY TOUGH TO OVERCOME. WILL LEAVE AN ISOLATED MENTION IN THE
FORECAST OVER CENTRAL AND NORTH-CENTRAL WISCONSIN. STRONG WARM
ADVECTION WILL PUSH TEMPS INTO THE LOWER 80S OVER CENTRAL
WISCONSIN...BUT A NE WIND WILL KEEP TEMPS IN THE 50S AND 60S OVER
FAR NE WISCONSIN.
.LONG TERM...TUESDAY NIGHT THROUGH MONDAY
ISSUED AT 233 PM CDT MON MAY 13 2013
MAIN FCST CONCERNS INCLUDE SVR TSTM POTENTIAL TUESDAY EVENING...
A DRY PERIOD FOR THE MIDDLE TO LATE PART OF THE WORK WEEK...THEN
A RETURN TO SHOWERY BUT SEASONABLE PERIOD FOR THE WEEKEND AND
EARLY NEXT WEEK.
NOTHING HAS CHANGED FOR TUESDAY NIGHT...WITH ENOUGH ELEVATED INSTABILITY
(MUCAPES 750-1500 J/KG) AND SHEAR (STG DEEP LAYER SHEAR AND 0-3 KM
HELICITIES OF 500-700) TO SUPPORT ELEVATED SUPERCELL TSTMS...BUT A
DRY AND CAPPED ATMOSPHERE LIKELY SUPPRESSING CONVECTIVE INITIATION.
HAD TO LIFT PARCELS FROM THE 850-750 MB LAYER TO GET CONVECTIVE
INHIBITION UNDER 50 J/KG...AND LOWER LEVEL PARCELS ARE MUCH MORE
STRONGLY CAPPED. BEST BEST FOR CONVECTIVE INITIATION WILL LIKELY BE
ON THE NOSE OF A 40 KT LLJ AS IT MOVES INTO NE WI DURING THE EVENING.
HAVE LOWERED POPS SLIGHTLY FROM THE PREVIOUS FEW FCSTS...BUT CAN`T
RISK A DRY FCST...GIVEN THE SVR WX PARAMETERS THAT ARE IN PLACE. SPC
HAS OUR AREA IN THE DAY 2 SEE TEXT...WHICH SEEMS REASONABLE. ANY
THREAT OF CONVECTION SHOULD END BY 06Z/WED AS THE H8 MOISTURE
CONVERGENCE SHIFTS EAST...AND THE COLD/OCCLUDED FRONT REACHES LAKE
MICHIGAN.
LOOKS LIKE A DRY PERIOD FROM LATE TUESDAY NIGHT THROUGH THURSDAY
NIGHT OR FRIDAY MORNING...AS THE COLD FRONT SAGS WELL SOUTH OF THE
REGION AND WEAK HIGH PRESSURE ARRIVES. DEEP MIXING ON WEDNESDAY AND
THURSDAY SHOULD ALLOW TEMPERATURES TO WARM INTO THE LOWER TO MIDDLE
70S IN MOST PLACES...AND ALSO CAUSE DEW POINTS/RELATIVE HUMIDITIES
TO CRASH DURING THE AFTERNOONS. GIVEN THE DRYNESS OF THE AIR MASS...
HAVE LOWERED MIN TEMPS CONSIDERABLY ON WEDNESDAY NIGHT...ESPECIALLY
IN THE TYPICAL COLD SPOTS IN NC WI.
THE PATTERN WILL UNDERGO A SIGNIFICANT CHANGE FOR THE WEEKEND AND
EARLY NEXT WEEK. AN UPPER LEVEL TROF IS EXPECTED TO DEVELOP OVER
THE ROCKIES ON FRIDAY...THEN TRACK EAST TO THE WESTERN GREAT LAKES
BY SUNDAY/MONDAY. AS THIS OCCURS...LOW PRESSURE WILL DEVELOP OVER
THE HIGH PLAINS...THEN LIFT EAST-NORTHEAST TOWARD THE REGION. THIS
WILL CAUSE THE OLD COLD FRONT TO LIFT BACK TO THE NORTH AS A WARM
FRONT...THEN BECOME STATIONARY ACROSS WI LATE IN THE PERIOD. THIS
WILL SET THE STAGE FOR AN EXTENDED PERIOD OF SHOWERS AND SCT TSTMS...
WITH THE POTENTIAL FOR SIGNIFICANT RAINFALL AMOUNTS. TEMPERATURES
SHOULD REMAIN NEAR SEASONAL NORMALS...WITH HIGHS IN THE 60S TO
AROUND 70.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 451 PM CDT MON MAY 13 2013
A NORTH TO SOUTH BAND OF LIGHT SHOWERS EXTENDING THE ENTIRE
LENGTH OF THE STATE WILL PASS QUICKLY OVER CENTRAL AND NORTHEAST
WISCONSIN THIS EVENING. AN ISOLATED MVFR CIG WILL BE POSSIBLE WITH
A FEW OF THE SHOWERS ALONG THIS BAND...OTHERWISE VFR CONDITIONS TO
DOMINATE THROUGH TUESDAY. INCREASING SOUTHWEST WINDS AT 1000 FEET AGL
AND ABOVE LATER THIS EVENING WILL INCREASE LLWS CONDITIONS BEFORE
SUBSINDING AFTER 15Z TUESDAY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......KIECKBUSCH
AVIATION.......TDH
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND TUESDAY
ISSUED AT 233 PM CDT MON MAY 13 2013
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW HIGH PRESSURE
CENTERED OVER THE CENTRAL GREAT LAKES AND A WARM FRONT EXTENDING
SOUTH ACROSS THE GREAT PLAINS. LEADING EDGE OF THE WARM/MOIST AIR
ALOFT IS PRODUCING A NARROW BAND OF LIGHT RAIN ALONG THE WI/MN
BORDER THIS AFTERNOON...WHICH IS MEASURING A HUNDREDTH OR TWO
ACCORDING TO THE OBS. BAND OF LIGHT RAIN ALONG THIS 295-300K
MOISTURE ADVECTION WILL PUSH INTO CENTRAL WISCONSIN AROUND
5PM...DESPITE VERY DRY AIR PRESENTLY AT THE SURFACE. WEST OF THE
WARM FRONT...TEMPERATURES ARE MAINLY IN THE 80S AND A COUPLE 90
DEGREE READINGS ARE OUT THERE AS WELL. THE MAIN FORECAST CONCERNS
ARE TIMING OF THE PRECIP LATER THIS AFTERNOON INTO THIS
EVENING...FOLLOWED BY TEMPS AND SMALL THUNDER CHANCES TOMORROW.
TONIGHT...295-300K MOISTURE ADVECTION WILL PUSH A BAND OF LIGHT RAIN
ACROSS THE AREA LATER THIS AFTERNOON AND THROUGH THE EVENING.
MID-LEVEL LAPSE RATES ARE POOR AND SURFACE HUMIDITIES ARE IN THE
20S...SO SHOWERS SHOULD NOT AMOUNT TO MUCH. BUT OBS UPSTREAM
INDICATE A HUNDREDTH OR TWO OF ACCUM...SO WILL SHOW THIS IN THE
FORECAST AND RAISE POPS INTO THE LIKELY RANGE. THIS BAND WILL EXIT
LATE THIS EVENING...BUT A SECONDARY SURGE OF MOISTURE MAY CAUSE
ADDITIONAL REDEVELOPMENT OF SHOWERS OVER THE EASTERN HALF OR THIRD
OF THE FORECAST AREA AFTER MIDNIGHT. THINK PRECIP CHANCES WILL
LIKELY BE OVER BY THE START OF THE MORNING COMMUTE WHILE SKIES WILL
BE CLEARING FROM WEST TO EAST AT THE SAME TIME. PLENTY OF CLOUDS
AND A LIGHT SE WIND WILL KEEP TEMPS CONSIDERABLY WARMER THAN LAST
NIGHT AND WILL GO WITH LOWS IN THE LOW TO MID 40S.
TUESDAY...ELEVATED WARM FRONT WILL BE SHIFTING ACROSS LAKE MICHIGAN
EARLY TUESDAY MORNING...WHICH WILL RESULT IN CLEARING SKIES ACROSS
EASTERN WISCONSIN EARLY ON. EVEN THOUGH WILL LIKELY SEE CIRRUS
OVERHEAD...MODELS FORECAST VERY DRY AIR ARRIVING IN THE LOW TO MID
LEVELS SO DO NOT SEE A THREAT OF PRECIP THROUGH MID-AFTERNOON. BY
MID TO LATE AFTERNOON...LOW PRESSURE WILL BE ACROSS CENTRAL
MINNESOTA...AND A 850MB LLJ WILL PUSH A WARM FRONT INTO SW
WISCONSIN. ORDINARILY...MASS CONVERGENCE ON THE NOSE OF THE LLJ
WOULD BE CONDUCIVE FOR THUNDERSTORMS...ESPECIALLY WITH MID-LEVEL
LAPSE RATES AROUND 8 C/KM....BUT THE INCOMING AIRMASS IS SO DRY
BELOW 600MB...AND EXPECT SURFACE DEWPOINTS TO FALL THROUGH THE
AFTERNOON. THIS RESULTS IN PROGGED CONVECTIVE INHIBITION OF 200-300
J/KG LATE IN THE AFTERNOON WHEN THE FORCING ARRIVES...WHICH LOOKS
AWFULLY TOUGH TO OVERCOME. WILL LEAVE AN ISOLATED MENTION IN THE
FORECAST OVER CENTRAL AND NORTH-CENTRAL WISCONSIN. STRONG WARM
ADVECTION WILL PUSH TEMPS INTO THE LOWER 80S OVER CENTRAL
WISCONSIN...BUT A NE WIND WILL KEEP TEMPS IN THE 50S AND 60S OVER
FAR NE WISCONSIN.
.LONG TERM...TUESDAY NIGHT THROUGH MONDAY
ISSUED AT 233 PM CDT MON MAY 13 2013
MAIN FCST CONCERNS INCLUDE SVR TSTM POTENTIAL TUESDAY EVENING...
A DRY PERIOD FOR THE MIDDLE TO LATE PART OF THE WORK WEEK...THEN
A RETURN TO SHOWERY BUT SEASONABLE PERIOD FOR THE WEEKEND AND
EARLY NEXT WEEK.
NOTHING HAS CHANGED FOR TUESDAY NIGHT...WITH ENOUGH ELEVATED INSTABILITY
(MUCAPES 750-1500 J/KG) AND SHEAR (STG DEEP LAYER SHEAR AND 0-3 KM
HELICITIES OF 500-700) TO SUPPORT ELEVATED SUPERCELL TSTMS...BUT A
DRY AND CAPPED ATMOSPHERE LIKELY SUPPRESSING CONVECTIVE INITIATION.
HAD TO LIFT PARCELS FROM THE 850-750 MB LAYER TO GET CONVECTIVE
INHIBITION UNDER 50 J/KG...AND LOWER LEVEL PARCELS ARE MUCH MORE
STRONGLY CAPPED. BEST BEST FOR CONVECTIVE INITIATION WILL LIKELY BE
ON THE NOSE OF A 40 KT LLJ AS IT MOVES INTO NE WI DURING THE EVENING.
HAVE LOWERED POPS SLIGHTLY FROM THE PREVIOUS FEW FCSTS...BUT CAN`T
RISK A DRY FCST...GIVEN THE SVR WX PARAMETERS THAT ARE IN PLACE. SPC
HAS OUR AREA IN THE DAY 2 SEE TEXT...WHICH SEEMS REASONABLE. ANY
THREAT OF CONVECTION SHOULD END BY 06Z/WED AS THE H8 MOISTURE
CONVERGENCE SHIFTS EAST...AND THE COLD/OCCLUDED FRONT REACHES LAKE
MICHIGAN.
LOOKS LIKE A DRY PERIOD FROM LATE TUESDAY NIGHT THROUGH THURSDAY
NIGHT OR FRIDAY MORNING...AS THE COLD FRONT SAGS WELL SOUTH OF THE
REGION AND WEAK HIGH PRESSURE ARRIVES. DEEP MIXING ON WEDNESDAY AND
THURSDAY SHOULD ALLOW TEMPERATURES TO WARM INTO THE LOWER TO MIDDLE
70S IN MOST PLACES...AND ALSO CAUSE DEW POINTS/RELATIVE HUMIDITIES
TO CRASH DURING THE AFTERNOONS. GIVEN THE DRYNESS OF THE AIR MASS...
HAVE LOWERED MIN TEMPS CONSIDERABLY ON WEDNESDAY NIGHT...ESPECIALLY
IN THE TYPICAL COLD SPOTS IN NC WI.
THE PATTERN WILL UNDERGO A SIGNIFICANT CHANGE FOR THE WEEKEND AND
EARLY NEXT WEEK. AN UPPER LEVEL TROF IS EXPECTED TO DEVELOP OVER
THE ROCKIES ON FRIDAY...THEN TRACK EAST TO THE WESTERN GREAT LAKES
BY SUNDAY/MONDAY. AS THIS OCCURS...LOW PRESSURE WILL DEVELOP OVER
THE HIGH PLAINS...THEN LIFT EAST-NORTHEAST TOWARD THE REGION. THIS
WILL CAUSE THE OLD COLD FRONT TO LIFT BACK TO THE NORTH AS A WARM
FRONT...THEN BECOME STATIONARY ACROSS WI LATE IN THE PERIOD. THIS
WILL SET THE STAGE FOR AN EXTENDED PERIOD OF SHOWERS AND SCT TSTMS...
WITH THE POTENTIAL FOR SIGNIFICANT RAINFALL AMOUNTS. TEMPERATURES
SHOULD REMAIN NEAR SEASONAL NORMALS...WITH HIGHS IN THE 60S TO
AROUND 70.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1227 PM CDT MON MAY 13 2013
A WARM FRONT OVER THE NORTHERN MISSISSIPPI VALLEY WILL
SHIFT EAST ACROSS WISCONSIN LATE THIS AFTERNOON THROUGH THE
EVENING. IT WILL BRING A COUPLE HOUR PERIOD OF LIGHT RAIN
SHOWERS...BUT CIGS TO REMAIN VFR DUE TO VERY DRY AIR IN THE LOW
LEVELS. CIGS WILL LOWER A BIT AFTER THE RAIN DEPARTS LATE THIS
EVENING BUT LOW LEVEL WIND SHEAR WILL THEN DEVELOP FOR A PERIOD.
CLOUDS TO CLEAR LATE TONIGHT AND INTO THE MORNING WHICH WILL SET UP
VFR CONDITIONS FOR MUCH OF THE DAY TOMORROW.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......KIECKBUSCH
AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
742 PM MDT TUE MAY 14 2013
.UPDATE...
ISSUED AT 738 PM MDT TUE MAY 14 2013
ISOLATED SHOWERS AND THUNDERSTORMS CONTINUE OVER THE NORTHERN
NEBRASKA PANHANDLE EARLY THIS EVENING WHILE MOST OF THE SHOWER AND
THUNDERSTORM ACTIVITY HAS DIED OFF OVER THE REST OF THE FORECAST
AREA. SHOWERS AND THUNDERSTORMS HAVE PRODUCED GUSTY WINDS.
TORRINGTON REPORTED A GUST OF 47 KTS WHILE THE ALLIANCE ASOS HIT
49 KTS. THE WIND GUST THREAT WILL QUICKLY SUBSIDE THIS EVENING AS
SHOWERS AND THUNDERSTORMS DIE OFF AND MOVE EAST OF THE AREA.
&&
.SHORT TERM...(TONIGHT THROUGH WEDNESDAY NIGHT)
ISSUED AT 234 PM MDT TUE MAY 14 2013
WIDESPREAD CUMULUS HAVE DEVELOPED ALONG THE SOUTHERN ZONES THIS
AFTERNOON IN A VERY DEEP BOUNDARY LAYER. RADAR IS SHOWING SOME
WEAK SHOWERS OUT THERE...HOWEVER ITS PROBABLY MOSTLY VIRGA WITH
GUSTY WINDS. THIS ISOLATED SHOWER ACTIVITY WILL LIKELY CONTINUE
INTO THE EVENING AS THE RUC SHOWS AROUND 100-200 J/KG OF CAPE
THROUGH AROUND 03Z. LAPS ANALYSIS SHOWS A WEAK FRONT LOCATED FROM
DOUGLAS TO SIDNEY WITH HIGHER LLVL MOISTURE (DEWPOINTS IN THE 40S)
BEHIND IT AND THE MUCH DRIER AIR TO THE SOUTH OF IT. THE MODELS
HAVE THIS BOUNDARY PUSHING TO THE SOUTHWEST OVERNIGHT AND STALLING
ALONG THE LARAMIE RANGE IN THE MORNING. BOTH THE GFS AND NAM SHOW
SOME IMPRESSIVE LLVL MOISTURE BEING ADVECTED IN ON EAST-TO-
SOUTHEAST WINDS BY THE MORNING. INCREASED DEWPOINTS INTO THE LOW-
TO-MID 40S OVER THE PLAINS OF SOUTHEAST WY FROM WEDNESDAY MORNING
THROUGH THE AFTERNOON.
THE COMBINATION OF HIGHER LLVL MOISTURE AND SLIGHTLY COOLER
MIDLEVEL TEMPS ON WEDNESDAY AFTERNOON WILL RESULT IN GOOD SFC
INSTABILITY ALONG AND EAST OF THE LARAMIE RANGE. THE GFS AND NAM
BOTH SHOW LIFTED INDICES OF -3C TO -5C WHICH TRANSLATES INTO
1000-1250 J/KG OF CAPE. THE TREND OF THE MODELS HAS BEEN TO
INCREASE CONVECTIVE POTENTIAL AND QPF FOR WEDNESDAY AFTERNOON AND
EVENING. FOR THIS REASON...UP POPS INTO THE CHANCE CATEGORY OVER
THE MTNS AND PLAINS. THE DEEP LAYER SHEAR DOES NOT LOOK IMPRESSIVE
OVER THE SOUTHERN ZONES (AROUND 20 KTS)...HOWEVER FURTHER TO THE
NORTH ACROSS CONVERSE/NIOBRARA COUNTIES THE MIDLEVEL WINDS ARE
STRONGER AND 0-6KM SHEAR APPROACHES 40 KTS. SO IT LOOKS LIKE THAT
WILL BE THE REGION TO MONITOR FOR STRONGER STORMS WITH SOME SMALL
HAIL POTENTIAL. THE STORMS THAT DEVELOP OVER THE LARAMIE RANGE IN
THE EARLY AFTERNOON WILL PROGRESS EASTWARD INTO PORTIONS OF THE
WESTERN NEBRASKA PANHANDLE BY THE EARLY EVENING. TEMPS WILL BE
AROUND 10 DEGREES COOLER ON WEDNESDAY WITH THE MOIST SE SFC WINDS
AND GREATER CLOUD COVER.
.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 234 PM MDT TUE MAY 14 2013
THURSDAY...WEAK SHORTWAVE RIDGING ALOFT. WILL SEE ISOLATED AFTERNOON
AND EVENING THUNDERSTORMS...PRIMARILY ORIENTED ALONG THE SURFACE
TROUGH AXIS FROM EASTERN WYOMING SOUTHWARD THROUGH EASTERN COLORADO.
FRIDAY...FLOW ALOFT BACKS TO SOUTHWEST IN ADVANCE OF NEXT SHORTWAVE
TROUGH ALOFT. QUITE WARM WITH A DECENT LOW LEVEL THERMAL RIDGE
ORIENTED NORTH TO SOUTH ALONG A DECENT SURFACE TROUGH OVER OUR
COUNTIES. ISOLATED AFTERNOON AND EVENING THUNDERSTORMS ALONG A LOW
LEVEL CONVERGENCE AXIS FROM CASPER TO CHADRON TO SIDNEY...WITH AREAL
COVERAGE OF THUNDERSTORMS MINIMIZED BY WARM TEMPERATURES ALOFT
PROVIDING SIGNIFICANT CONVECTIVE INHIBITION...CIN.
SATURDAY...DECENT NEGATIVELY TILTED SHORTWAVE TROUGH ALOFT ROTATES
EASTWARD ACROSS OUR COUNTIES AND ALONG WITH ITS ASSOCIATED PACIFIC
ORIGIN COLD FRONT...EXPECT ISOLATED TO SCATTERED AFTERNOON AND
EVENING THUNDERSTORMS...MOST NUMEROUS NEAR THE MOUNTAINS DUE TO
DIFFERENTIAL HEATING AND OROGRAPHIC EFFECTS.
SUNDAY...A DEFINITE BRITISH ISLES COASTAL FEEL TYPE DAY. BRISK
WINDS...COOLER TEMPERATURES AND ISOLATED TO SCATTERED AFTERNOON AND
EVENING SHOWERS AND THUNDERSTORMS ON TAP WITH NORTHWEST FLOW ALOFT
AND ENOUGH LOW AND MID LEVEL MOISTURE TO BE LIFTED BY DAYTIME
HEATING EFFECTS AND CYCLONIC FLOW ALOFT. LOW LEVEL DOWNSLOPE WINDS
WILL PRODUCE A RAIN SHADOW EFFECT FROM WHEATLAND TO CHEYENNE AND
MINIMIZE PRECIPITATION COVERAGE.
MONDAY...REFRESHINGLY COOL START TO THE TRADITIONAL WORKWEEK IN THE
WAKE OF THE RELATIVELY STRONG SHORTWAVE TROUGH PASSAGE AND WITH COOL
NORTH WINDS IN USHERING IN RELATIVELY COOL CANADIAN AIR. ISOLATED
AFTERNOON SHOWERS AND THUNDERSTORMS. TEMPERATURES WILL STILL BE NEAR
NORMAL THOUGH.
TUESDAY...TRANSITORY SHORTWAVE RIDGE ALOFT MOVES ACROSS OUR COUNTIES
AND ALONG WITH MUCH LESS LOW AND MID LEVEL MOISTURE...ONLY ISOLATED
AFTERNOON AND EVENING THUNDERSTORMS EXPECTED.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY AFTERNOON)
ISSUED AT 402 PM MDT TUE MAY 14 2013
VFR PREVAILS.
THROUGH 02Z TONIGHT...ISOLATED HIGH BASED SHOWERS AND THUNDERSTORMS
WILL AFFECT THE LARAMIE AND CHEYENNE TAFS WITH GUSTY AND ERRATIC
WINDS AS ISOLATED SHOWERS AND THUNDERSTORMS DEVELOP OVER AND NEAR
THE SNOWY...SIERRA MADRE AND SOUTHERN LARAMIE RANGES. SHOWERS AND
THUNDERSTORMS WILL PRODUCE LOCALIZED TURBULENCE.
PERIODS OF SCATTERED TO BROKEN LOW AND MIDDLE CLOUDS AT OR ABOVE
6000 FEET AGL.
A WEAK COLD FRONT WILL MOVE SOUTHWESTWARD TO THE LEE OF THE LARAMIE
RANGE THIS EVENING. SURFACE HIGH PRESSURE WILL MOVE INTO SOUTH
DAKOTA TONIGHT PRODUCING WEAK LOW LEVEL UPSLOPE SOUTH AND
SOUTHEAST WINDS ACROSS TAF SITES. LOW LEVEL SOUTH AND SOUTHEAST
WINDS WILL STRENGTHEN WEDNESDAY MORNING...WITH SCATTERED CUMULUS
AND TOWERING CUMULUS DEVELOPMENT ALONG AND WEST OF INTERSTATE 25
BY LATE MORNING...ALONG WITH ISOLATED THUNDERSTORMS IN THIS AREA
TOWARDS NOON. SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP
OVER SOUTHEAST WYOMING AFTER NOON WEDNESDAY PRODUCING LOCALIZED
MVFR AND ERRATIC AND GUSTY WINDS TO 50 MPH.
&&
.FIRE WEATHER...
ISSUED AT 234 PM MDT TUE MAY 14 2013
RELATIVE HUMIDITY VALUES HAVE DROPPED BELOW 15 PERCENT THIS
AFTERNOON ACROSS MUCH OF THE LOWER ELEVATIONS IN A VERY WARM
AIRMASS. WINDS HAVE BECOME WEAK NORTHERLY OVER THE PANHANDLE
BEHIND A WEAK FRONT...WITH GUSTS GENERALLY BELOW 20 MPH.
TEMPERATURES ON WEDNESDAY ARE EXPECTED TO BE AROUND 10 DEGREES
COOLER WITH SOUTHEAST WINDS ALONG AND EAST OF THE LARAMIE RANGE.
THE INCREASING LOW LEVEL MOISTURE WILL PROMOTE SCATTERED SHOWERS
AND THUNDERSTORMS ON WEDNESDAY AFTERNOON AND EVENING.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...LIEBL
SHORT TERM...FINCH
LONG TERM...RUBIN
AVIATION...RUBIN
FIRE WEATHER...FINCH
AREA FORECAST DISCUSSION
NWS ALBANY NY
418 AM EDT WED MAY 15 2013
.SYNOPSIS...
A WARM FRONT WILL APPROACH TODAY BRINGING RAIN SHOWERS
AND PERHAPS A THUNDERSTORM TO THE AREA...MAINLY DURING THE
AFTERNOON AND EVENING HOURS. THEN A COLD FRONT WITH LIMITED
MOISTURE WILL APPROACH AND MOVE THROUGH THE REGION LATE THURSDAY
INTO THURSDAY EVENING. THE NEXT CHANCE FOR SOME WET WEATHER IS
EXPECTED DURING THE SECOND HALF OF THE WEEKEND.
&&
.NEAR TERM /TODAY THROUGH TONIGHT/...
STRONG SURFACE WARM FRONT AND MID LEVEL THETA-E ADVECTION ARE
RESULTING IN ELEVATED SHOWERS AND SOME THUNDERSTORMS ACROSS THE
GREAT LAKE STATE TRACKING EAST-SOUTHEAST ACROSS LOWER ONTARIO
PROVINCE. PER THE NCEP MODEL SUITE AND HOURLY RAP UPDATES...THE
WARM FRONT WILL APPROACH WESTERN AND CENTRAL NY THIS MORNING WITH
SCATTERED SHOWERS EXPECTED AHEAD OF THIS FEATURE. WE WILL SLOWLY
BRING UP POPS THROUGH THE MORNING HOURS. IT APPEARS THE WARM FRONT
WILL BECOME PINCHED OFF ALONG THE I81 CORRIDOR INITIALLY THEN
SOUTH OF I90 THROUGH THE AFTERNOON HOURS AS THE MAIN SURFACE LOW
TRACKS ALONG THE ST LAWRENCE RIVER VALLEY. THE EML AND ASSOCIATED
MID LEVEL LAPSE RATES ARE EXPECTED TO TRACK ACROSS PA/NJ AND MID
ATLANTIC REGION WHERE THE SWODY1 SEE TEXT REMAINS IN PLACE. SO
WHILE NO SEVERE WEATHER IS EXPECTED TODAY...WITH AN INCREASE IN
THE WIND FIELDS AND HIGHER PWATS ADVECTING INTO THE REGION /AOA
1.30 INCHES/...WOULD NOT BE SURPRISED TO SEE SOME OF THE DEEPER
CONVECTIVE ELEMENTS PRODUCING SUB-SEVERE WIND GUSTS. THE COLD
FRONT /OR OCCLUDED FRONT/ IS EXPECTED TO PASS THROUGH THE HUDSON
VALLEY REGION AROUND SUNSET. THIS WOULD BE THE WINDOW OF
OPPORTUNITY FOR THOSE DEEPER CONVECTIVE ELEMENTS ASSUMING WE ARE
ABLE TO ROOT THOSE SURFACE PARCELS IN THE WARM SECTOR. FOR
NOW...PER THE EXPERIMENTAL REFLECTIVITY FORECASTS...WE WILL KEEP
POPS BELOW LIKELY THRESHOLDS AND WATCH TRENDS THROUGH THE DAY. AS
FOR TEMPERATURES...AFTER A CHILLY START...THE WARMER AIR SHOULD
ASSIST WITH VALLEY TEMPS CLIMBING INTO THE MID-UPPER 60S...WITH
60-65F FOR THE HIGHER TERRAIN.
TONIGHT...THE PASSAGE OF THE FRONT SHOULD BE EAST OF OUR NEW
ENGLAND COUNTIES SHORTLY AFTER SUNSET WITH DRIER AIR ADVECTING
INTO THE REGION. THIS WILL ALLOW FOR CLEARING SKIES AND CLOSE TO
SEASONABLE OVERNIGHT LOWS...MAINLY LOWER TO MIDDLE 40S.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
THURSDAY AND THURSDAY NIGHT...A NARROW WEDGE OF HIGH PRESSURE WILL
MOVE ACROSS THE REGION DURING THURSDAY WITH TRANQUIL CONDITIONS.
HOWEVER...THE WESTERLY WINDS WILL BECOME QUITE BRISK AND GUSTY AS
MIXING LAYER HEIGHTS CLIMB TO AROUND 8-10K FEET. WINDS RESIDING AT
THIS LEVEL ARE EXPECTED TO BE AT OR ABOVE 40KTS. THE HIGHER
TERRAIN AND SOME MESOSCALE IMPACTS FROM FUNNELING DOWN THE MOHAWK
AND INTO THE TACONICS COULD POTENTIALLY BE PROBLEMATIC. THE AIR
COMING OUT OF CANADA WILL NOT BE ESPECIALLY COOL THIS GO
ROUND...WITH H850 TEMPERATURES ONLY COOLING TO AN AVERAGE OF +8C
DURING THE DAY...LOWER-MIDDLE 70S FOR MANY LOCATIONS WITH UPPER
60S ACROSS THE DACKS AND SOUTHERN GREENS.
NCEP MODEL SUITE AND INTERNATIONAL GUIDANCE ARE CONVERGING WITH A
PASSAGE OF A SECONDARY COLD FRONT THURSDAY EVENING. WHILE MOISTURE
WILL REMAIN RATHER MEAGER...CAN NOT RULE OUT A SHOWER OR TWO
ACROSS THE DACKS...LAKE GEORGE SARATOGA REGION AND PORTIONS OF
SOUTHERN VT SO WE WILL HOLD ONTO THE SLIGHT CHANCE POPS.
FRIDAY...HIGH PRESSURE WILL BE STILL BE BUILDING IN FROM JAMES BAY
OF CANADA AS THOSE H850 TEMPS DIP BACK INTO THE LOWER SINGLE
DIGITS. IT SHOULD BE ANOTHER FINE SPRING DAY FILLED WITH MOSTLY
SUNNY SKIES AND A NORTHWEST BREEZE BUT NOT AS STRONG AS THURSDAY.
TEMPERATURES WILL TOP OUT AROUND 70 IN THE HUDSON VALLEY...60S
HIGHER TERRAIN.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
THE FIRST HALF OF THE PERIOD LOOKS RATHER BENIGN...AS A LARGE AREA
OF HIGH PRESSURE BUILDS ACROSS THE REGION FROM THE GREAT LAKES AND
SOUTHEAST CANADA FRIDAY NIGHT INTO SATURDAY. WITH A NORTHWEST FLOW
REGIME...THIS PATTERN SHOULD BRING MAINLY CLEAR AND COOL
NIGHTS...WITH SEASONABLY WARM DAYS AND SOME FAIR WEATHER CUMULUS
BUILDING DURING THE AFTERNOON HOURS. WINDS WILL TURN SOUTHERLY ON
SUNDAY...AS A RETURN FLOW AROUND DEPARTING HIGH PRESSURE OFF THE NEW
ENGLAND COAST DEVELOPS. THIS WILL SIGNIFY THE START OF A WARMING
TREND...BUT THERE COULD BE A FEW EXTRA CLOUDS AROUND AND PERHAPS A
BRIEF SHOWER SUNDAY INTO SUNDAY NIGHT WITHIN THE WARM ADVECTION
REGIME.
OTHERWISE...MODELS IN GOOD AGREEMENT WITH BUILDING AN UPPER LEVEL
RIDGE WITH A SURGE OF WARMTH ACROSS THE REGION MONDAY INTO TUESDAY
OF NEXT WEEK. SOME DIFFERENCES IN THAT THE GFS HAS A FEW WRINKLES
UNDER THE RIDGE WITH A FEW WEAK DISTURBANCES MOVING THROUGH...WHILE
THE ECMWF IS SHOWING MORE OF A CLASSIC UPPER RIDGE WITH A MORE
AMPLIFIED PATTERN. EITHER WAY IT LOOKS LIKE A DECENT WARMUP...BUT
CHANCES FOR RAINFALL ARE MORE UNCERTAIN. WILL MENTION SLIGHT CHANCE
POPS FOR NOW MONDAY INTO MONDAY NIGHT...INCREASING TO CHANCE FOR
TUESDAY AS THE RIDGE IS FORECAST TO START FLATTENING BY THEN.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH MUCH OF THE 24 HOUR
TAF PERIOD ENDING 06Z THURSDAY. HOWEVER...THERE IS A CHANCE FOR SOME
INTERMITTENT MVFR OR EVEN BRIEF IFR CONDITIONS TODAY ASSOCIATED WITH
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS. AN APPROACHING SURFACE
WARM FRONT AND UPPER LEVEL DISTURBANCE WILL BE RESPONSIBLE FOR THE
INCREASING CHANCES FOR SHOWERS FROM LATE THIS MORNING THROUGH THE
AFTERNOON. EXPECTING COVERAGE TO BE SCATTERED...SO WILL MENTION VCSH
AT ALL THE TERMINALS FOR NOW. MODELS FORECASTING THE BEST
INSTABILITY TO BE DISPLACED SOUTH OF THE REGION...HOWEVER SOME
LIMITED INSTABILITY AND FAIRLY POTENT DYNAMICS/LIFT COULD RESULT IN
SOME THUNDER. SHOWERS SHOULD SHIFT EAST OF OUR AREA AND INTO NEW
ENGLAND THIS EVENING.
WINDS WILL INITIALLY BE NEAR CALM...THEN INCREASE FROM THE SOUTH
AROUND 10 TO 15 KT WITH GUSTS NEAR 20 KT LATE THIS MORNING
CONTINUING THROUGH THE EARLY EVENING. A BOUNDARY WILL MOVE THROUGH
AROUND THE 00Z THURSDAY TIME FRAME...WHICH WILL SHIFT WINDS TO THE
WEST.
OUTLOOK...
THU...VFR. NO SIG WX. BREEZY.
FRI-SAT...VFR. NO SIG WX.
SUN...VFR...SLGT CHC -SHRA.
&&
.FIRE WEATHER...
...WIND GUSTS UP TO 30 MPH ARE POSSIBLE TODAY...
...WIND GUSTS UP TO 40 MPH ARE EXPECTED ON THURSDAY...
THERE WILL BE SCATTERED SHOWERS AND PERHAPS A THUNDERSTORM TODAY
AS A WARM FRONT APPROACHES. MINIMUM RH VALUES TODAY ARE EXPECTED
TO REMAIN IN THE 40 PERCENTILE. SOUTHERLY WINDS OF 10 TO 20 MPH
ARE EXPECTED WITH GUSTS UP TO 30 MPH POSSIBLE.
TONIGHT...DRIER CONDITIONS WITH A GRADUAL REDUCTION IN WIND GUSTS.
MAXIMUM RH VALUES SHOULD REBOUND TO BETWEEN 80 AND 100
PERCENT...ESPECIALLY IN LOCATIONS WHERE PRECIPITATION OCCURRED.
THURSDAY...A BREEZY DRY DAY WITH WESTERLY WINDS AVERAGING 15 TO
25 MPH...WITH GUSTS TO 40 MPH EXPECTED. RH VALUES LOOK TO DROP TO
AN AVERAGE 30 PERCENT. DEPENDING ON GREEN-UP STATUS FIRE WEATHER
HEADLINES MIGHT HAVE TO BE BROACHED. A SHOWER IS POSSIBLE IN THE
ADIRONDACKS AND SOUTHERN GREENS BY LATE IN THE DAY AS A SECONDARY
COLD FRONT APPROACHES. OTHERWISE IT WILL BE MIX OF CLOUDS AND
SUNSHINE.
FRIDAY AND SATURDAY LOOK DRY WITH LESS WIND AND MORE NORMAL
RECOVERIES AT NIGHT.
&&
.HYDROLOGY...
CHANCES OF RAIN SHOWERS AND PERHAPS A THUNDERSTORM WILL INCREASE
TODAY...MAINLY DURING THE AFTERNOON AND EVENING HOURS AS A WARM
FRONT APPROACHES. RAINFALL AMOUNTS WEDNESDAY AND WEDNESDAY NIGHT
ARE GENERALLY EXPECTED TO BE AROUND OR A LITTLE UNDER A QUARTER OF
AN INCH. THIS RAINFALL SHOULD HAVE LITTLE OR NO EFFECT ON
WATERSHEDS IN OUR HYDRO SERVICE AREA /HSA/.
AFTER THAT...MAINLY DRY WEATHER IS EXPECTED THROUGH AT LEAST THE
FIRST HALF OF THE WEEKEND.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.CLIMATE...
THE GROWING SEASON IS UNDERWAY ACROSS THE MID HUDSON VALLEY...GREATER
CAPITAL DISTRICT...LAKE GEORGE SARATOGA REGION AND SOUTHERN
LITCHFIELD COUNTY CONNECTICUT.
START DATES FOR THE REST OF EAST CENTRAL NY AND ADJACENT WESTERN
NEW ENGLAND ARE AS FOLLOWS...
MAY 15TH...THE MOHAWK VALLEY...EASTERN CATSKILLS...TACONICS...
BENNINGTON COUNTY VT...THE BERKSHIRES AND LITCHFIELD HILLS.
MAY 20TH...EASTERN WINDHAM COUNTY VT.
MAY 25TH...THE SOUTHERN ADIRONDACKS AND WESTERN WINDHAM COUNTY VT.
DURING THE GROWING SEASON FREEZE WARNINGS ARE ISSUED WHEN THE
TEMPERATURES ARE FORECAST TO BE 32 DEGREES OR LOWER...AND FROST
ADVISORIES ARE ISSUED WHEN THE TEMPERATURES ARE FORECAST TO BE IN
THE 33 TO 36 DEGREES RANGE.
THE START OF THE GROWING SEASON FOR A GIVEN AREA IS BASED ON THE
MEDIAN DATE OF THE LAST SPRING FREEZE BASED ON 1981-2010 NORMALS AND
IN COORDINATION WITH NEIGHBORING NWS OFFICES.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...FROST ADVISORY UNTIL 7 AM EDT THIS MORNING FOR CTZ001-013.
NY...FROST ADVISORY UNTIL 7 AM EDT THIS MORNING FOR NYZ038>040-
047>053-058>061-063>066.
FREEZE WARNING UNTIL 7 AM EDT THIS MORNING FOR NYZ041-043-054-
083-084.
MA...FROST ADVISORY UNTIL 7 AM EDT THIS MORNING FOR MAZ025.
FREEZE WARNING UNTIL 7 AM EDT THIS MORNING FOR MAZ001.
VT...FREEZE WARNING UNTIL 7 AM EDT THIS MORNING FOR VTZ013.
&&
$$
SYNOPSIS...BGM
NEAR TERM...BGM
SHORT TERM...BGM
LONG TERM...JPV
AVIATION...JPV
FIRE WEATHER...HWJIV/BGM
HYDROLOGY...BGM
CLIMATE...IAA
WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
310 AM EDT WED MAY 15 2013
.DISCUSSION...
TODAY-TONIGHT...
A LARGE HI PRES RIDGE EXTENDING FROM BERMUDA TO THE WRN GOMEX WILL
DRIFT SLOWLY INTO THE ATLC UNDER THE INFLUENCE OF THE SRN BRANCH OF
THE H30-H20 JET STREAM. POSITION OF THE RIDGE WILL MAINTAIN A STEADY
E/SE BREEZE ACRS CENTRAL FL. EVENING SOUNDINGS MEASURED A DRY AND
VERY STABLE AIRMASS OVERHEAD...PWAT VALUES BTWN 0.6"-0.8" WITH A
SHARP SUBSIDENCE INVERSION IN THE H85-H70 LYR. RAP ANALYSIS
INDICATING H100-H85 MEAN RH VALUES BTWN 70-80PCT...IR SAT PICS
SHOWING A FEW POCKETS OF STRATOCU ALONG AND N OF THE BAHAMA BANK.
BASE OF THE SUBSIDENCE INVERSION WILL CAP VERTICAL MOTION BTWN
5-6KFT...ONLY SCT CLOUD COVER ANTICIPATED. DESPITE NEAR FULL SUN...
THE ONSHORE BREEZE WILL KEEP MAX TEMPS SLIGHTLY BLO AVG...L80S ALONG
THE COAST...M80S INTERIOR. WEAK PGRAD AND CLEAR SKIES TONIGHT WILL
ALLOW THE BNDRY LYR TO DECOUPLE...RESULTING IN GOOD RADIATIONAL
CONDITIONS. MIN TEMPS GENERALLY IN THE L/M60S INTERIOR...IMMEDIATE
SPACE/TREASURE COAST WILL HOLD IN THE M/U60S.
LATE WEEK...LITTLE CHANGE IN LARGE SCALE FEATURES IS ADVERTISED
THROUGH THE END OF THE WEEK. AN WEST TO EAST ELONGATED HIGH
PRESSURE RIDGE FROM THE GULF TO THE WRN ATLC BASIN WILL CONTINUE
TO PRODUCE GENERALLY FAIR CONDITIONS LOCALLY WITH SEASONAL TEMPS.
STRENGTH OF THE RIDGE LOOKS TO EASE FRI AS A SHORTWAVE ALOFT MOVES
ACROSS THE GULF AND FL REGION. WL KEEP POP JUST BELOW MENTIONABLE
LEVEL THROUGH FRI BUT WOULDN`T BE SURPRISED TO SEE A DIURNAL
STORM OR TWO WEST OF ORLANDO DURING LATE FRI AFTERNOON.
EXTENDED...NEXT WEEK BEGINS WITH WEAKENING HIGH PRESSURE NORTH OF
THE AREA. SOMEWHAT HIGHER MOISTURE COMBINED WITH LESS CONV INHIBITION
WITH WEAKENING OF RIDGE NR AREA WL ALLOW FOR ISOLD/SCT DIURNAL
PCPN. INLAND STORM CHCS IMPROVE SAT/SUN AND BEST PLACEMENT WL BE
INLAND WHERE MID TO LATE AFTERNOON BOUNDARY MERGERS WL FORCE A
LITTLE MORE ACTIVITY. PRESENCE OF ONSHORE FLOW WL KEEP TEMPS
MODERATED WITH NEAR SEASONAL READINGS AND PARTLY CLOUDY SKIES.
EARLY SIGNALS BEYOND DAY 7 SHOW HIGHER MOISTURE AND WOULD EXPECT A
MENTIONABLE RAIN CHC FOR THE EXTENDED PERIODS PAST THIS TIME.
&&
.AVIATION...
THRU 16/00Z...VFR ALL SITES. BTWN 15/18Z-15/22Z...OCNL SFC WND
G20KTS S OF KVRB.
&&
.MARINE...
TODAY-TONIGHT...HI PRES RIDGE AXIS OVER N FL WILL MAINTAIN A GENTLE
TO MODERATE E/SE BREEZE...SEAS 2-3FT NEARSHORE AND 3-4FT OFFSHORE
MAINLY IN A 9SEC SWELL.
LATE WEEK...ONSHORE GRADIENT WINDS AROUND 5 TO 10 KTS WITH SOME
HIGHER AFTERNOON GUSTS WL CONTINUE INTO THE WEEKEND. SEAS
GENERALLY WL REMAIN IN THE 2-4FT RANGE.
&&
.FIRE WEATHER...
TODAY-TONIGHT...E/SE SFC/TRANSPORT FLOW WILL GRADUALLY MODIFY THE
DRY AIR OVER CENTRAL FL. MIN RH VALUES ALONG AND N OF THE I-4
CORRIDOR MAY FALL BLO 35PCT FOR 4-6HRS...NO OTHER FIRE WX ISSUES
ANTICIPATED. CONTINUATION OF ONSHORE FLOW THROUGH THE REMAINDER OF
THE WEEK WL MITIGATE ANY LOW RH DURATION CONCERNS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 80 63 83 66 / 0 0 10 10
MCO 86 63 86 65 / 0 0 0 10
MLB 81 66 82 69 / 0 0 0 10
VRB 80 65 82 66 / 0 0 0 10
LEE 86 63 87 67 / 0 0 10 10
SFB 86 63 87 66 / 0 0 10 10
ORL 86 63 87 68 / 0 0 0 10
FPR 80 65 82 66 / 0 0 0 10
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM...BRAGAW
LONG TERM....PENDERGRAST
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
242 AM EDT WED MAY 15 2013
.SYNOPSIS...
06Z WATER VAPOR AND H4 RAP ANALYSIS SHOWING A BROAD MID/UPPER LEVEL
RIDGE IN CONTROL FROM THE CENTRAL GULF OF MEXICO TO THE SOUTHEASTERN
CONUS AND FLORIDA PENINSULA. WV IMAGERY INDICATES A SWATH OF VERY
DRY MID/UPPER LEVEL AIR OVER OUR HEADS THIS MORNING...AND THIS IS
CONFIRMED WITH A QUICK GLANCE AT THE 15/00Z KTBW SOUNDING WHICH
SHOWS THIS DRY COLUMN ALOFT AND CONTINUES THE TREND DOWN ALL THE WAY
TO THE SURFACE BOUNDARY LAYER. DUE TO THE DRY COLUMN AND OVERALL
SUPPRESSION UNDERNEATH THE UPPER RIDGE...OUR SKIES ARE MOSTLY CLEAR
THIS MORNING. FURTHER DOWNSTREAM WE FIND AN ILL-DEFINED
TROUGH/DISTURBANCE CROSSING THE MEXICAN PLATEAU/SOUTHERN PLAINS
WHICH WILL APPROACH OUR AREA LATER IN THE WEEK WITH LITTLE IF ANY
FANFARE. NORTHERN STREAM FLOW IS CURRENTLY RIDING ALONG AND JUST
SOUTH OF THE U.S/CANADIAN BORDER BEFORE DIPPING INTO LONGWAVE
TROUGHING NOW EXITING THE NORTHEAST AND MID-ATLANTIC COASTS.
AT THE SURFACE...SUBTROPICAL RIDGE AXIS EXTENDS FROM OFF THE GA
COAST BACK WESTWARD THROUGH THE NATURE COAST AND INTO THE NE GULF OF
MEXICO. LIGHT GRADIENT ON THE SOUTH SIDE OF THE RIDGE AXIS IS
PROVIDING A WEAK EAST/NE FLOW FOR MUCH OF THE FORECAST AREA.
TEMPERATURES ARE ONCE AGAIN QUITE COOL FOR THE MIDDLE OF MAY.
A NOTICEABLE WARMING OF THE OVERNIGHT LOWS IS EXPECTED INTO
THE LATER PORTION OF THE WEEK.
&&
.SHORT TERM (TODAY THROUGH FRIDAY)...
TODAY/TONIGHT...STACKED RIDGING WILL CONTROL OUR WEATHER THROUGH THE
NEXT 24 HOURS KEEPING THE FORECAST DRY WITH SEASONABLE DAYTIME
TEMPERATURES AND SLIGHTLY BELOW NORMAL OVERNIGHT READINGS. MOSTLY
CLEAR SKIES THIS MORNING WILL GIVE WAY TO A FEW-SCT CU
FIELDS...ESPECIALLY SOUTH OF THE I-4 CORRIDOR...BUT STILL FEEL SAFE
IN CALLING CONDITIONS MOSTLY SUNNY. SOME OF THE MORE SENSITIVE
HI-RES CONVECTION ALLOWING MODELS ARE TRYING TO BRING A FEW ISOLATED
SHOWERS WESTWARD FROM THE EAST COAST INTO THE SOUTHERN TIER OF
ZONES. VERTICAL ANALYSIS OF THIS CORES SHOW THAT THEY FAIL TO EVEN
REACH 10KFT AGL BEFORE A HOSTILE THETA-E ENVIRONMENT FOR DEEP
CONVECTION RESULTS IN RAPID CU DISSIPATION. WILL DISREGARD ANY
CHANCE OF EVEN LIGHT ISOLATED SHOWERS THIS AFTERNOON AND KEEP THE
FORECAST DRY. TEMPERATURES WILL REBOUND NICELY INTO THE MID 80S AWAY
FROM THE BEACHES WHERE AN AFTERNOON SEA-BREEZE WILL HOLD TEMPS DOWN
A FEW DEGREES. THIS SEA-BREEZE SHOULD BE HELD VERY CLOSE TO THE
COAST THROUGH THE AFTERNOON TO THE SOUTH OF TAMPA BAY WHERE 12-14
KNOTS OF FLOW JUST ABOVE THE SURFACE WILL BE SUFFICIENT TO
SIGNIFICANTLY IMPEDE THE INLAND PROGRESS OF THE CIRCULATION. NORTH
OF TAMPA BAY IN CLOSER PROXIMITY TO THE RIDGE AXIS...FLOW IS
GENERALLY 10 KNOTS OR LESS AND WILL BE LESS EFFICIENT AT HOLDING
BACK THE SEA-BREEZE. TEMPERATURES WILL BE MORE SEASONABLE TONIGHT
WITH MANY LOCATIONS FAILING TO DROP OUT OF THE 60S. NORMALLY COLDER
SPOTS ACROSS THE NATURE COAST AND INTERIOR SOUTHERN ZONES MAY
BRIEFLY REACH THE UPPER 50S TOWARD SUNRISE.
THURSDAY/THURSDAY NIGHT...
MID/UPPER LEVEL RIDGE WILL QUICKLY BREAK DOWN AND BE SUPPRESSED
SOUTHWARD IN RESPONSE TO THE APPROACH AND ARRIVING OF SHORTWAVE
ENERGY MOVING EASTWARD ALONG THE NORTHERN GULF COAST. THE
DISTURBANCE IS ACTUALLY DECENT IN TERMS OF THE OVERALL SYNOPTIC
FORCING OVERSPREADING THE REGION...HOWEVER COLUMN MOISTURE BELOW
500MB WILL SIMPLY BE LACKING...AND THE ENVIRONMENT WILL REMAIN
HOSTILE FOR CONVECTION TO BECOME ESTABLISH. CAN NEVER RULE OUT A FEW
ISOLATED SHOWERS (ESPECIALLY NORTH OF I-4)...HOWEVER FAIRLY
CONFIDENT THAT TEMPORAL AND/OR SPATIAL COVERAGE WILL BE SMALL ENOUGH
TO LEAVE MENTION OUT OF THE CURRENT FORECAST. REALLY THE MAIN IMPACT
WE SHOULD SEE FROM THIS PASSING ENERGY WILL BE A POSSIBLE BAND OF
MID/HIGH LEVEL CLOUDS...AGAIN MAINLY OVER THE NORTHERN ZONES. HIGH
TEMPERATURES THURSDAY WILL BE WELL UP INTO THE 80S INLAND...AND
SLIGHTLY COOLER AT THE BEACHES AS FLOW AGAIN TURNS ONSHORE FOR THE
AFTERNOON. LOW TEMPERATURES AT NIGHT ONLY DROP TO THE LOWER 60S FOR
THE COOLEST SPOTS.
FRIDAY...
SHORTWAVE AXIS WILL CROSS THE AREA DURING THE DAY AND QUICKLY EXIT
TO OUR EAST FRIDAY NIGHT. WILL SEE A SMALL INCREASE IN OVERALL
COLUMN MOISTURE FOR MOST SPOTS AND THEREFORE ADDED IN A SLIGHT
CHANCE 20% FOR AN AFTERNOON/EVENING SHOWER. HOWEVER...ANY CONVECTIVE
CELLS WILL STILL HAVE TO OVERCOME A HOSTILE THETA-E ENVIRONMENT
BETWEEN 5-15KFT. THIS HOSTILE ENVIRONMENT SHOULD KEEP COVERAGE QUITE
LOW AND EXPECT MOST SPOTS TO ESCAPE WITH A DRY DAY. TEMPERATURES
WILL AGAIN BE SEASONABLE...WITH WARMEST LOCATIONS FLIRTING WITH 90
BY MID/LATE AFTERNOON. ENJOY!
&&
.LONG TERM (SATURDAY THROUGH NEXT TUESDAY)...
UPPER LEVEL RIDGING HOLDS OVER THE GULF AND WESTERN GULF COAST FOR
MOST OF THE WEEKEND AS A COUPLE OF SHORT WAVE TROUGHS...THE FIRST
ONE OVER THE MID-MISSISSIPPI/OHIO VALLY REGION AND THE SECOND OFF
THE SE U.S. COAST...SLIDE EAST. BY LATE SUN THE FIRST SHORT WAVE
TROUGH IS OVER THE MID-ATLANTIC STATES WITH THE RIDGE AXIS IN THE
CENTRAL GULF. THE RESULT FOR FL IS A GENERALLY WEAK PATTERN ALOFT.
FOR THE START OF NEXT WEEK A ROBUST TROUGH OR LOW DROPS INTO THE
NORTHERN/CENTRAL PLAINS AND MID-WEST AND MOVES EAST TO THE GREAT
LAKES BY MID-WEEK WITH THE RIDGE WEAKLY MOVING OUT OVER THE
ATLANTIC.
AT THE SURFACE...HIGH PRESSURE OVER THE ATLANTIC ALONG 30 NORTH
LATITUDE RIDGES WEST TO THE GULF COAST REGION THROUGH THE WEEKEND.
ON MON AN AREA OF HIGH PRESSURE SLIDES OFFSHORE NEW ENGLAND AND
MOVES SOUTH...REINFORCING THE HIGH ALONG 30 NORTH AS IT/S RIDGE AXIS
REACHES TO THE GULF COAST/SE U.S.
THE SURFACE RIDGE KEEPS EAST TO SE LOW LEVEL FLOW IN PLACE...BUT
WEAK ENOUGH FOR AFTERNOON SEA BREEZES..WHICH PROVIDES A GRADUAL
INCREASE IN MOISTURE. THIS MOISTURE ALONG WITH THE SEA BREEZES AND
WEAK PATTERN ALOFT WILL PRODUCE SLIGHT CHANCE TO LOW END CHANCE
SHOWERS AND STORMS...WITH TIMING AFTERNOON AND EARLY EVENING.
TEMPERATURES WILL BE NEAR SEASONABLE.
&&
.AVIATION...
VFR CONDITIONS CONTINUE FOR THE NEXT 24 HOURS WITH SKC BECOMING
FEW-SCT MAINLY CU/SC. EASTERLY WINDS EXCEPT FOR BAY/SEA BREEZE AT
TPA/PIE/SRQ.
&&
.MARINE...
THE SUBTROPICAL RIDGE AXIS WILL REMAIN IN PLACE ACROSS THE NORTHEAST
GULF OF MEXICO INTO THE UPCOMING WEEKEND. PATTERN THROUGH FRIDAY
WILL RESULT IN GENERALLY EAST TO WEST FLOW DURING THE OVERNIGHT AND
MORNING HOURS WITH THE FLOW THEN WEAKENING FOR THE AFTERNOON AND
EVENING...WHILE ONSHORE SEA BREEZES DEVELOP NEAR THE COAST. WINDS
WILL APPROACH EXERCISE CAUTION LEVELS FOR A TIME EARLY THIS
MORNING...ESPECIALLY SOUTH OF TARPON SPRINGS...BUT THEN RELAX BY
MIDDAY. ANOTHER BRIEF EASTERLY SURGE IS POSSIBLE TO THE SOUTH OF
TAMPA BAY EARLY THURSDAY MORNING.
&&
.FIRE WEATHER...
HIGH PRESSURE WILL KEEP OUR WEATHER DRY AND GENERALLY QUIET THE NEXT
SEVERAL DAYS. RELATIVE HUMIDITY VALUES ARE FORECAST TO DROP BELOW 35
PERCENT FOR A FEW HOURS THIS AFTERNOON AWAY FROM THE IMMEDIATE
COAST...EXTEND DURATIONS OF THESE CRITICAL VALUES ARE GENERALLY NOT
ANTICIPATED AND WILL NOT COINCIDE WITH ANY ZONES WHERE ERC VALUES
ARE ABOVE 37. A SLOW INCREASE IN MOISTURE WILL CONTINUE INTO
THURSDAY AND FRIDAY. CURRENT FORECAST HAS A BRIEF PERIOD OF NEAR 35
PERCENT RELATIVE HUMIDITY INLAND FROM THE I-75 CORRIDOR ON THURSDAY
AND KEEPS ALL AREAS ABOVE CRITICAL VALUES OF RELATIVE HUMIDITY FOR
FRIDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 87 67 87 70 / 0 0 0 0
FMY 88 64 88 68 / 05 0 10 10
GIF 87 64 88 67 / 0 0 10 10
SRQ 86 65 86 68 / 05 0 10 10
BKV 86 60 88 64 / 0 0 0 0
SPG 85 70 86 72 / 0 0 0 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/MARINE/FIRE WX...MROCZKA
LONG TERM/AVIATION/DECISION SUPPORT...RUDE
AREA FORECAST DISCUSSION
NWS DES MOINES IA
400 AM CDT WED MAY 15 2013
.SHORT TERM.../TODAY /...
ISSUED AT 359 AM CDT WED MAY 15 2013
SURFACE HIGH PRESSURE WILL MOVE INTO THE STATE
TODAY AND WILL PROVIDE A MUCH QUIETER DAY ACROSS THE FORECAST AREA.
THERE IS A SMALL POTENTIAL FOR SOME VERY HIGH BASED SHOWERS AND A
STRAY THUNDERSTORM ACROSS NORTHERN IOWA THIS MORNING...DUE TO SOME
WEAK THETA-E ADVECTION AND FORCING BETWEEN 700-500MB. HRRR HAS THE
ISOLATED SHOWERS THROUGH 18Z...BUT 00Z NMM WRF DIMINISHING THE
SHOWER ACTIVITY BEFORE ENTERING THE STATE. LEANED TOWARD THE HRRR AS
IT SEEMED TO HAVE A DECENT GRASP ON CURRENT RADAR TRENDS.
WEAK BOUNDARY ACROSS SOUTHERN IOWA LOOKS TO BE A FOCAL POINT FOR
SOME ISOLATED THUNDERSTORMS THIS AFTERNOON. AGAIN...VERY HIGH BASED
AS VERY MINIMAL MOISTURE BELOW 700MB.
MAX TEMPS TODAY A LITTLE TRICK AS THINK GUIDANCE IS TOO LOW AGAIN
AND FELT CONFIDENT ENOUGH TO TWEAK TEMPS UP TODAY...ESPECIALLY
ACROSS THE SOUTH WHERE THE COOLER AIR DOES NOT REACH THIS AREA UNTIL
THE AFTERNOON. WENT ABOVE GUIDANCE ACROSS THE CENTRAL TO SOUTHERN
PORTIONS OF THE FORECAST AREA...WHICH WAS FAIRLY CLOSE TO THE MAV
MOS GUIDANCE. IN NORTHERN IOWA WENT CLOSER THE THE NAM/MET MOS
GUIDANCE FOR MAX TEMPS.
.LONG TERM.../TONIGHT THROUGH TUESDAY/...
ISSUED AT 359 AM CDT WED MAY 15 2013
RELATIVELY ACTIVE PERIOD THROUGH THE EXTENDED. HIGH PRESSURE WILL
GRADUALLY DEPART TONIGHT INTO THURSDAY AND AS IT DOES...A STALLED
FRONTAL BOUNDARY OVER NORTHERN MISSOURI WILL BEGIN TO LIFT BACK
NORTH INTO IOWA. AS THIS OCCURS...A PLUME OF MOISTURE LIFTING
THROUGH OKLAHOMA AND KANSAS WILL ARRIVE INTO SRN IA. THIS WILL
BRING BACK THE CHANCE FOR THUNDERSTORMS IN THAT REGION. A STRONG
PV ANOMALY OVER SRN NEVADA WILL APPROACH IA LATE THURSDAY AND
THURSDAY NIGHT. PREFER THE FARTHER NORTH NAM/ECMWF SOLUTION OVER
THE LESS ORGANIZED AND FARTHER SOUTH GFS. THIS WOULD PLACE THE
FOCUS FOR ADDITIONAL THUNDERSTORMS OVER NORTHWEST AND NORTH
CENTRAL IOWA. THIS POPS CONTINUE INTO FRIDAY MAINLY OVER THE
NORTH. EXPECT AT THIS POINT THAT POPS MAY BE OVERDONE FOR FRIDAY.
HAVE BEGUN TO TRIM BACK OVER THE CENTRAL AND SOUTH BUT IT MAY VERY
WELL BE MOSTLY DRY MOST LOCATIONS. THE SAME CAN BE SAID FOR FRIDAY
NIGHT WHERE POPS HAVE BEEN DROPPED FOR ALL BUT THE FAR NORTHEAST.
IOWA WILL BE IN THE WARM SECTOR ON SATURDAY AND WHILE LOW POPS
REMAIN...THE CONVECTIVE INHIBITION SHOULD HOLD STRONG MUCH OF THE
DAY. THE PRECIPITATION CHANCES THROUGH THE REMAINDER OF THE PERIOD
ARE MORE COMPLEX. THE INITIAL WAVE TO MOVE INTO THE INTER MOUNTAIN
WEST WILL BE FOLLOWED BY ANOTHER INTENSE PIECE OF ENERGY SATURDAY
NIGHT INTO SUNDAY. LONG RANGE GUIDANCE IS BEGINNING TO FAVOR THE
TWO TO MERGE AND FORM A CLOSED LOW TO THE WEST/NORTHWEST OF THE
AREA. THE FIRST WAVE WILL NUDGE THE UPPER LEVEL RIDGE ENOUGH EAST
SATURDAY NIGHT TO BRING A RETURN FOR PRECIPITATION
CHANCES...MAINLY OVER THE NORTH HOWEVER THE EVOLUTION TO A CLOSE
LOW WILL SLOW THE BOUNDARY ARRIVAL TO LATER SUNDAY INTO MONDAY.
INCREASING SOUTHWEST FLOW OVER THE STATE WILL KEEP THE PERIOD
ACTIVE AND EVENTUALLY SHOULD BRING A SEVERE WEATHER THREAT TO THE
STATE. TEMPERATURES THROUGH THE PERIOD WILL GENERALLY BE ABOVE
SEASONAL VALUES. COOLER ACROSS THE SOUTH ON THURSDAY DUE TO
ENHANCED CLOUD COVER THEN WARMER AGAIN FRIDAY INTO SATURDAY.
&&
.AVIATION...15/06Z
ISSUED AT 1129 PM CDT TUE MAY 14 2013
A COLD FRONT HAS SLOWED BUT IS STILL PUSHING SOUTHEAST ACROSS THE
AREA...WITH SW WINDS AT DSM/OTM AND NW WINDS AT THE OTHER
TERMINALS. WINDS WILL SWITCH TO NW EVERYWHERE BEFORE
SUNRISE...THEN TURN THROUGH N TO NE OR E BY WED EVENING...BUT WITH
SPEEDS LESS THAN 12 KT THROUGHOUT. ONLY HIGH CLOUDS ARE EXPECTED
AND NO PRECIP FORECAST OTHER THAN POSSIBLY A FEW SPRINKLES BUT
EVEN THOSE ARE UNLIKELY AT ANY GIVEN TERMINAL.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...PODRAZIK
LONG TERM...DONAVON
AVIATION...LEE
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1219 AM CDT WED MAY 15 2013
...UPDATED FOR THE AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 931 AM CDT TUE MAY 14 2013
THE 14.12Z 250 HPA RAOB MAP SHOWED TWO JETS ACROSS NORTH AMERICA. THE
POLAR JET WAS LOCATED ACROSS THE NORTHERN PORTIONS OF UNITED STATES
AND INTO CANADA. THE STRONGEST WINDS WERE LOCATED FROM NOVA SCOTIA AND
INTO THE CANADIAN MARITIMES WITH MAGNITUDES AROUND 180 KT. NEXT, THE
SUBTROPICAL JET WAS LOCATED FARTHER SOUTH WITH HIGHEST MAGNITUDES AROUND
90 KT ACROSS FLORIDA. CLOSER TO KANSAS, FLOW WAS QUITE WEAK AT 15 KT. AT
500 HPA, A TROF WAS MOVING ONSHORE ACROSS CENTRAL CALIFORNIA. DAMPENING
SHORTWAVE RIDGING WAS DOWNSTREAM OF THIS FEATURE ACROSS THE 4 CORNERS
REGION. A WEAK LOW WAS LOCATED ACROSS PORTIONS OF MEXICO. A SHORTWAVE
TROF WAS MOVING ACROSS THE CENTRAL CANADIAN PRAIRIES. AN ELONGATED TROF
WAS LOCATED ACROSS THE NE U.S. AND SE CANADA. AT 700 HPA, TEMPERATURES
ACROSS SW KANSAS WERE FAIRLY WARM (10 DEG C). AT 850 HPA, 25 DEG C AT
KDDC WAS SLIGHTLY UNDER THE +2 STANDARD DEVIATION STATISTICAL MARK.
AT THE SFC, A COLD FRONT WAS LOCATED ACROSS THE NORTHERN PLAINS AND
A SURFACE LEE TROF WAS LOCATED ACROSS FAR WESTERN KANSAS.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 252 PM CDT TUE MAY 14 2013
TONIGHT:
EARLY AFTERNOON VISIBLE SATELLITE IMAGERY SHOWS A FIELD OF CUMULUS HUMILIS
CLOUDS ACROSS NORTHWEST KANSAS. THESE CLOUDS ARE IN ASSOCIATION WITH
A LEE SURFACE TROF ACROSS NORTHWEST KANSAS AND WEAK INSTABILITY. RAP
AND HRRR KEEPS THIS ACTIVITY NORTHWEST OF THE FORECAST AREA OF RESPONSIBILITY
THROUGH TONIGHT. I HAVE 14 PERCENT PRECIPITATION PROBABILITIES IN THE
GRIDS THROUGH EARLY EVENING ACROSS WEST CENTRAL KANSAS. OTHERWISE, TONIGHT
WILL BE CLEAR AND PRECIPITATION FREE. LEE TROUGHING WILL CONTINUE THROUGH
THE OVERNIGHT PERIOD. SOUTHERLY WINDS IN ASSOCIATION WITH THIS FEATURE
WILL CONTINUE OVERNIGHT AS WELL. THESE WINDS WILL KEEP TEMPERATURES
MILD WITH LOWS IN THE UPPER 50S AND LOWER 60S DEG F.
TOMORROW:
ON WEDNESDAY, A LEE INDUCED LOW/TROF ACROSS SOUTHEASTERN COLORADO WILL DEEPEN
THROUGH THE AFTERNOON. THIS WILL CAUSE A WARM FRONT TO LIFT NORTHWARD
ACROSS PORTIONS OF WESTERN KANSAS. HIGHS TOMORROW IN THE WARM SECTOR
WILL BE WARM TO HOT AGAIN WITH HIGHS IN THE 86-91 DEG F RANGE. RAMPED
UP POPS IN THE AFTERNOON ACROSS THE EASTERN PORTIONS OF THE FORECAST
AREA OF RESPONSIBILITY. THERE IS SOME UNCERTAINTY IN WHERE CONVECTION
WILL DEVELOP ALONG THE FRONT AS MODELS DIFFER WITH THE FRONT POSITION.
12Z NAM DEVELOPS THUNDERSTORMS FROM LIBERAL TO HAYS, WHILE 12Z GFS KEEPS
PRECIPITATION MAINLY EAST OF HIGHWAY 183. THE WRF-NMM ECHOES THE NAM
SOLUTION, WHERE THE WRF-ARW KEEPS THE REGION DRY. DUE TO THE UNCERTAINTY,
WILL LIMIT PRECIPITATION PROBABILITIES IN THE SLIGHT CHANCE CATEGORY.
IF THE NAM SOLUTION IS CORRECT WITH MOISTURE, MLCAPE LOOKS TO BE AROUND
1500-3000 J/KG, MAINLY ACROSS SC KANSAS. 0-6 KM BULK SHEAR IS ON THE
WEAKER SIDE AT 30-35 KT. UPPER LEVEL WIND SHEAR IS VERY WEAK AT 15-30
KT. LCL`S WILL BE FAIRLY HIGH AS WELL. PUTTING THIS ALL TOGETHER, THE
OVERALL THREAT FOR HIGH END SEVERE WEATHER IS VERY LOW. THE MAIN THREAT
TOMORROW IS MARGINAL HAIL SIZE PERHAPS UP TO QUARTERS AND 50-60 MPH
OUTFLOW FROM THUNDERSTORMS.
LASTLY, LESS FIRE WEATHER CONCERNS ARE EXPECTED TOMORROW AFTERNOON AS
SLIGHTLY HIGHER DEWPOINTS AND RESULTANT HIGHER RELATIVE HUMIDITIES ARE
EXPECTED.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 354 PM CDT TUE MAY 14 2013
PRECIPITATION CHANCES, SEVERITY, AND COVERAGE WILL BE CHALLENGES IN
THE FORECAST LATE WEEK INTO THE WEEKEND...ALONG WITH AFTERNOON
TEMPERATURES WITH DRYLINE POSITION UNCERTAINTY.
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT:
A LOW AMPLITUDE SHORTWAVE TROUGH (CURRENTLY SEEN ON WATER VAPOR
SPINNING ACROSS CENTRAL CALIFORNIA) WILL BE MOVING TOWARD THE
CENTRAL HIGH PLAINS DURING THIS TIME FRAME. A WEAK FRONT MOVING
INTO EAST-CENTRAL COLORADO AND WEST-CENTRAL KANSAS WILL BE THE FOCUS
FOR THUNDERSTORMS LATE AFTERNOON WEDNESDAY...BUT THIS FRONT WILL
DISSOLVE BY WEDNESDAY NIGHT. A SMALL...LOOSELY ORGANIZED AREA OF
CONVECTION AHEAD OF THE APPROACHING WAVE MAY HOLD TOGETHER AS IT
APPROACHES FAR WEST-CENTRAL KANSAS...BUT CONFIDENCE IN THIS IS VERY
LOW AND ONLY SLIGHT CHANCE POPS ARE WARRANTED AT THIS TIME. ON
THURSDAY...THERE IS A LOT OF DISAGREEMENT ON THE 850MB
THERMODYNAMICS/MOISTURE BETWEEN THE NCEP MODELS AND THE ECMWF MODEL.
THE GFS AND NAM SHOW COPIOUS AMOUNTS OF MOISTURE AND NEAR-SATURATED
RH AT 850MB THROUGH 18Z THURSDAY WHICH IS AFFECTING THE BOUNDARY
LAYER TEMPERATURES TO THE POINT THAT THE NCEP MODELS KEEP
TEMPERATURES IN THE 70S FOR MUCH OF THE DAY. THE NCEP MODELS TEND TO
BE A BIT TOO AGGRESSIVE IN HOLDING ONTO STRATUS TOO LONG SO THE
OFFICIAL FORECAST FOR HIGHS THURSDAY WILL REFLECT MORE CLOSELY THE
ECMWF MODEL.
A DRYLINE WILL NO DOUBT BE A PREVAILING FEATURE, HOWEVER, WHICH
SHOULD FOCUS A FEW ISOLATED STORMS BY LATE AFTERNOON/EARLY
EVENING...ESPECIALLY SINCE THE AFOREMENTIONED LOW AMPLITUDE
SHORTWAVE TROUGH WILL BE PASSING JUST TO THE NORTH AIDING IN SOME
SLIGHT MID LEVEL COOLING AND OVERALL SLIGHT ENHANCEMENT OF DEEP
TROPOSPHERIC UPWARD VERTICAL MOTION. MID LEVEL FLOW AT THE BASE OF
THIS TROUGH AXIS OF 25 TO 35 KNOTS (500MB) ACROSS WESTERN KANSAS
WILL PROVIDE THE NECESSARY SHEAR ALONG WITH SOUTH-SOUTHEAST BOUNDARY
LAYER FLOW FOR SUPERCELL STORMS (ALONG WITH THE UPPER 50S TO NEAR 60
DEWPOINTS AT THE SURFACE). ANY THUNDERSTORMS LATE THURSDAY/THURSDAY
EVENING SHOULD DISSOLVE AFTER SUNSET AS INSOLATION GOES AWAY AND THE
SHORTWAVE TROUGH EXITS THE CENTRAL PLAINS.
FRIDAY AND SATURDAY:
A MUCH MORE IMPRESSIVE PACIFIC JET WILL ENTER THE SOUTHWEST/GREAT
BASIN REGION DURING THIS TIME FRAME...ENTERING THE ROCKIES AND
WESTERN PLAINS SATURDAY. THE DRYLINE WILL BE THE FOCUS FOR
THUNDERSTORMS BOTH OF THESE DAYS...BUT SATURDAY WILL BE THE BETTER
DAY OF THE TWO FOR MORE ORGANIZED SUPERCELL STORMS GIVEN THE GREATER
LOW LEVEL CONVERGENCE EXPECTED ALONG THE DRYLINE NEAR AND JUST SOUTH
OF THE SURFACE LOW. WILL HAVE CHANCE POPS NORTH OF A DIGHTON TO
LACROSSE LINE WHERE THE FORECAST SURFACE LOW WILL BE PER THE ECMWF
MODEL. SOUTH AND SOUTHWEST OF THE SURFACE LOW...HOT TEMPERATURES
WILL BE FOUND OVER A LARGER AREA THAN PREVIOUS DAYS WITH SOME UPPER
90S EVEN POSSIBLE.
SUNDAY AND BEYOND:
THE INITIAL JET STREAK WILL LIFT NORTH INTO THE NORTHERN PLAINS
LEADING TO THE FORMATION OF AN UPPER LOW...HOWEVER AN ENERGETIC JET
WILL STILL REMAIN ACROSS THE GREAT BASIN INTO THE CENTRAL ROCKIES
WHICH COULD LEAD TO DEVELOPMENT OF A SECONDARY LOW LATE SUNDAY INTO
MONDAY. SOME SLIGHT CHANCE POPS WERE INCLUDED THROUGH THE ALLBLEND
GUIDANCE ON SUNDAY AND MONDAY GIVEN THE PROSPECTS OF SOME POTENTIAL
POST-FRONTAL CONVECTION ROLLING EAST OFF THE EASTERN COLORADO
TERRAIN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1209 AM CDT WED MAY 15 2013
THIS PERIOD WILL HAVE VFR CONDITIONS THROUGH THE NEXT 24 HOURS.
A TROUGH OF LOW PRESSURE ASSURE SOUTHWEST WINDS OF 10 TO 15 KNOTS
THIS MORNING, BUT THEY WILL CHANGE TO SOUTHEAST AFTER SUNRISE, AND
THEN TO EASTERLY BY THIS AFTERNOON. A LOW PRESSURE AREA WILL MOVE
THROUGH NORTHERN KANSAS, AND HELP PULL DOWN A COLD FRONT THIS
AFTERNOON. CIGS MAY RESULT IN THE BKN080-120 RANGE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 60 86 64 91 / 20 10 20 20
GCK 59 88 62 95 / 10 20 20 20
EHA 58 92 60 97 / 10 20 20 20
LBL 60 92 61 97 / 10 10 20 20
HYS 60 83 64 85 / 20 10 20 10
P28 63 84 65 85 / 20 10 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM...UMSCHEID
AVIATION...BURKE
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
351 AM EDT WED MAY 15 2013
.SYNOPSIS...
A FRONTAL BOUNDARY WILL APPROACH FROM PENNSYLVANIA LATE TODAY AND
STALL OUT OVER THE SOUTHERN MID-ATLANTIC THROUGH THE END OF THE
WEEK AND INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE CONVEYOR BELT OF ISOLATED SHOWERS CONTINUES OVER THE NERN
QUADRANT OF THE CWA...A STEADY STREAM OF SPRINKLES COMING OUT OF MID
CLOUD DECKS. BUT THE MAIN STORY OF THE NEAR TERM IS THE
TEMPERATURES. WE`RE NOW A SOLID 10-15 DEG ABOVE CONDITIONS AT THIS
TIME 24 HRS AGO. THIS DIFFERENCE WILL CARRY OVER AND EVEN MORE SO
INTO THE AFTN HRS TODAY...AS WE PEAK WELL INTO THE 80S ACROSS MUCH
OF THE REGION.
A RELATIVELY SMALL BUT VERY STRONG UPPER RIDGE CENTERED OVER THE NRN
PLAINS DEVELOPED A LOCALIZED AREA OF TEMPS IN THE UPPER 90S/L100S
YESTERDAY AFTN. AT THE SAME TIME NEAR TRIPLE-DIGIT HEAT WAS
OCCURRING...ONLY A FEW HUNDRED MILES TO THE EAST - OVER THE GREAT
LAKES - TEMPS WERE ONLY THE 50S. IN BETWEEN THESE AREAS RESIDES A
HIGHWAY OF FAST UPPER FLOW CREATED BY THESE STRONG OPPOSING FORCES.
A PIECE OF THIS ENERGY FROM THE WEST WILL BE FORCED TOWARD THE AREA
TODAY.
A COMPLEX SFC SCENARIO W/ ALL THESE POTENT BUT SMALL SCALE FEATURES
MOVING ABOUT THE NRN HALF OF THE COUNTRY TODAY. A WARM FRONT HAS
BEEN FORMING ALONG THE I-70 CORRIDOR OF THE UPPER MIDWEST...
STRETCHING HUNDREDS OF MILES AND WILL EVENTUALLY BECOME A WX-MAKER
FOR THE AREA BEGINNING LATE TONIGHT AND INTO EARLY FRI. FOR
TODAY...A COLD FRONT DRIFTING DOWN FROM THE SYSTEM THAT BROUGHT COOL
TEMPS TO THE GREAT LAKES YESTERDAY WILL STAY WELL TO THE NORTH BUT
JOIN UP W/ THE WARM FRONT AND BECOME A PSEUDO-STATIONARY BOUNDARY
NEAR THE MASON-DIXON LINE OVERNIGHT.
LOCAL GUIDANCE LIKE THE HRRR AND GFS-BASED WRF MODELS TAKING THE
ACTIVITY CURRENTLY OVER THE LAKE ERIE REGION...SPILLING IT OVER INTO
THE ERN HALF OF THE CWA LATER THIS MRNG AND EARLY AFTN. PLACED AN
ISOLATED/SCATTERED POP FOR THESE AREAS...DRYING OUT AND CLEARING OUT
DURING THE AFTN. A QUICK RETURN TO THE CLOUDS AND PRECIP ALONG THE
MASON-DIXON LINE LATE THIS AFTN THOUGH...AS HI-RES MODELS CONTINUING
TO DEPICT A DEVELOPMENT OF CONVECTION JUST TO OUR NORTH -
POTENTIALLY DRIFTING ESE INTO THE NRN TIER COUNTIES TOWARD LATE
EVE...DISSIPATING OVERNIGHT BEFORE HEADING TOO FAR SOUTH.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
FRONTAL BOUNDARY IS FORECAST TO SINK SOUTHWARD ACROSS THE SOUTHERN
MID-ATLANTIC THROUGH THE END OF THE WEEK...POSSIBLY SNAKING BACK UP
THE APPALACHIANS ON FRIDAY. WITH FRONTAL BOUNDARY OVER THE CWA ON
THURSDAY...WILL CONTINUE WITH CHANCE POPS MAINLY IN THE
AFTERNOON/EVENING WITH MAXIMA IN THE LOWER TO MID 80S.
WITH FRONT SAGGING A LITTLE FURTHER SOUTH INTO FRIDAY...WILL FOCUS
POPS ACROSS THE SOUTHERN HALF ON THE CWA WITH MAXIMA POSSIBLY A
COUPLE OF DEGREES LOWER.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
FRONTAL BOUNDARY IS FORECAST TO REMAIN SOUTH OF THE AREA OVER THE
WEEKEND...THEN LIFTS BACK NORTH AS A WARM FRONT EARLY NEXT WEEK IN
ADVANCE OF THE NEXT SHORTWAVE. FEW ADJUSTMENTS WERE MADE TO THE
FORECAST WHICH INCLUDE CHANCE POPS THROUGH MUCH OF THE PERIOD.
&&
.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
LITTLE HAS CHANGED IN TERMS OF THE SOLID 7-8KFT DECK OVER THE METRO
DC/BALT AREAS AND EVEN A FEW INTERMITTENT SPRINKLES ALONG THE WAY.
THIS WILL CONTINUE THRU DAWN AND POSSIBLY INTO THE LATE MRNG HRS
ACROSS A PORTION OF NERN MD. THIS ACTIVITY IS EXPECTED TO DISSIPATE
AND RECEDE TO THE NORTH DURING THE AFTN HRS...AS SLY WINDS PICK UP
INTO THE G20-25KT RANGE. MID DECKS WILL RETURN FROM THE NORTH LATE
THIS EVE...BUT MAINLY TO THE NORTH OF THE I-66 CORRIDOR W/ SOLID VFR
CONDITIONS THRU THE TAF PERIOD.
FRONTAL BOUNDARY IS FORECAST TO STALL OUT TO THE SOUTH OF THE AREA
DURING THE LATE WEEK-WEEKEND PERIOD. WITH BOUNDARY FAIRLY
CLOSE...CONVECTION IS POSSIBLE MAINLY IN THE AFTERNOON/EVENING EACH
DAY.
&&
.MARINE...
SLY CHANNELING CONTINUES OVERNIGHT AND WILL CONTINUE TO SLOWLY BUILD
W/ OBS HOVERING IN THE LOW-END SCA RANGE. THESE CONDITIONS WILL
SPREAD FURTHER NORTH INTO THE MRNG HRS...AND OVER THE TP RVR BY LATE
MRNG. THE AFTN HRS WILL SEE THE HIGHER SYNOPTIC GUSTS THIS AFTN...W/
MOST AREAS IN SOLID SCA RANGE AND A FEW GUSTS IN THE U20KT RANGE
BEFORE SUNSET. A FEW ISOLATED SHOWERS WILL ALSO CONTINUE THIS
MRNG...AND AGAIN ANOTHER ROUND OVER THE NRN BAY LATE TONIGHT.
FRONTAL BOUNDARY SLIPS SOUTH OF THE WATERS LATE WEEK AND REMAINS
SOUTH THROUGH THE WEEKEND. GRADIENT IS EXPECTED TO REMAIN FAIRLY
WEAK THROUGH THE PERIOD. AS WINDS BECOME SOUTHEAST OVER THE
WEEKEND...WINDS MAY CREEP UP CLOSE TO SCA LEVELS OVER PORTIONS OF
THE WATERS.
&&
.TIDES/COASTAL FLOODING...
THE SLY CHANNELING OF WINDS UP THE MAIN STEM OF THE BAY HAS
INCREASED POSITIVE TIDAL ANOMALIES TOWARD THE 1 FT ABOVE MARK BUT
STILL CLOSER TO 3/4FT ATTM. WATER LEVEL MODEL GUIDANCE KEEPING
ANNAPOLIS UNDER MINOR THRESHOLDS FOR THE UPCOMING H.T. CYCLE WHICH
WILL BE THE MOST SENSITIVE AND BEST CHANCE FOR MINOR TIDAL
FLOODING IN THE NEAR TERM. WINDS WILL CONTINUE TO GUST OUT OF THE
SOUTH FOR MUCH OF THE DAY...BEFORE A COLD FRONT ARRIVES LATE
TONIGHT AND BEGINS TO TAPER OFF THESE WINDS AND CHANGE DIRECTIONS
TO MORE WLY AND CAUSE LEVELS TO DROP AGAIN.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ531>534-
537-539>541-543.
SMALL CRAFT ADVISORY FROM NOON TODAY TO 8 PM EDT THIS EVENING
FOR ANZ530-535-536-538-542.
&&
$$
SYNOPSIS...GMS/BPP
NEAR TERM...GMS
SHORT TERM...BPP
LONG TERM...BPP
AVIATION...GMS/BPP
MARINE...GMS/BPP
TIDES/COASTAL FLOODING...GMS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
140 AM EDT WED MAY 15 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 422 PM EDT TUE MAY 14 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A ZONAL MID/UPPER LEVEL
PATTERN ACROSS THE NRN CONUS WITH A PROMINENT SHORTWAVE TROUGH NEAR
WINNIPEG. AT THE SFC...A 992 MB LOW WAS ALSO LOCATED OVER SE
MANITOBA WITH A COLD FRONT THROUGH NW MN INTO ERN SD. A WARM FRONT
STRETCHED FROM CNTRL MN INTO SRN WI. RADAR INDICATED WEAK RETURNS
WITH VERY LIGHT SHOWERS(VIRGA OR SPRINKLES) THROUGH CNTRL UPPER MI
AS THE BAND OF 310K (750-600 MB)ISENTROPIC LIFT MOVES THROUGH THE
AREA. SATELLITE SHOWED SKIES CLEARING OVER THE WEST AS DRIER AIR
BEHIND THE PCPN BAND MOVES IN.
TONIGHT...MODELS SUGGEST THAT AS THE MID LEVEL SHRTWV TROUGH AND
ASSOCIATED SFC TROUGH MOVES THROUGH UPPER MI SOME SHOWERS MAY
DEVELOP...MAINLY ACROSS NRN LAKE SUPERIOR AND POSSIBLY INTO THE NRN
PORTIONS OF UPPER MI ON THE SRN TAIL OF THE STRONGER QVECTOR CONV
AND FAVORABLE ISENTROPIC ASCENT JUST AHEAD OF THE SFC TROUGH. MUCAPE
VALUES (LIFTING FROM NEAR 750 MB) OF 500-1000 J/KG STILL SUPPORT A
CONDITIONAL THREAT OF TSRA. ALTHOUGH EFFECTIVE SHEAR VALUES ARE
MARGINAL (20-30 KT) SOME SMALL HAIL MAY BE POSSIBLE WITH ANY TSRA
THAT DEVELOP. CONFIDENCE IN SHRA/TSRA DEVELOPMENT IS LIMITED AS
MODELS HAVE TRENDED TOO HIGH WITH LOW LEVEL MOISTURE AVAILABILITY.
SO...ONLY LOWER END CHANCE POPS WERE INCLUDED.
WED...MODEL SOUNDINGS SHOW STRONG MID-LVL DRYING/SUBSIDENCE IN THE WAKE OF
THE COLD FRONT AS 850 MB TEMPS DROP TO AROUND 5C EARLY WED BUT
REBOUND TO TO AROUND 8C-9C WED AFTERNOON. MIXING HEIGHTS ABOVE 800
MB SHOULD MIX A SIGNIFICANT ENOUGH PORTION OF THE VERY DRY 800-650 MB
LAYER TO DROP DEWPOINTS INLAND TO AROUND 30F. WITH TEMPS INTO THE
LOWER TO MID 70S...RH VALUES WILL DROP TO AROUND 20 PERCENT. NW WIND
SHOULD ALSO INCREASE TO AROUND 15 MPH WITH GUSTS OF 20-25 MPH IN THE
AFTERNOON. SO...A FIRE WEATHER WATCH WAS ISSUED FOR MOST OF INLAND
WEST AND CENTRAL UPPER MICHIGAN.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 444 PM EDT TUE MAY 14 2013
OUR STRONGER WINDS WILL QUICKLY DIMINISH WEDNESDAY NIGHT...EVEN WITH
A REINFORCING SFC TROUGH STRETCHED W-E OVER LAKE SUPERIOR AT 06Z
THURSDAY SINKING SE ACROSS EASTERN UPPER MI BY 12Z THURSDAY. WITH
THAT RH VALUES SHOULD QUICKLY REBOUND TO 35 PERCENT OR BETTER BY 03Z
THURSDAY.
BEHIND THE EXITING TROUGH...HIGH PRESSURE SITUATED OVER S CENTRAL
CANADA WEDNESDAY NIGHT WILL PUSH ACROSS THE CWA AND BE DIRECTLY
OVERHEAD DURING THE DAY THURSDAY...BEFORE SLOWLY EXITING EASTERN
UPPER MI/LAKE SUPERIOR THURSDAY NIGHT INTO FRIDAY.
THURSDAY WILL BE DRY ONCE AGAIN FOR SOUTH CENTRAL AREAS...AND IN
PARTICULAR GOGEBIC...ONTONAGON...IRON...AND DICKINSON COUNTIES.
WINDS WILL BE MUCH LIGHTER THAN WEDNESDAY GIVEN THE DIMINISHED
PRESSURE GRADIENT...AVERAGING 5-10KTS. A WILDFIRE POTENTIAL
STATEMENT MAY BE NEEDED...BUT IS REALLY MARGINAL GIVEN THE NEAR
NORMAL TEMPS FOR THIS TIME OF YEAR...AND LIGHTER WINDS. THE WINDS
ARE THE MAIN THREAT THIS TIME OF YEAR...GIVEN THAT THE MAIN CARRIER
OF FIRES IS THE DRY GRASSES.
THE LINGERING HIGH OVER THE EAST WILL KEEP DRIER AIR IN
PLACE...LIMITING THE POTENTIAL FOR ANY SHOWERS TO MOVE MUCH EAST OF
A LINE FROM MQT TO ESC UNTIL SATURDAY MORNING.
EXPECT INCREASED S FLOW STARTING FRIDAY NIGHT...IN ADVANCE OF A
NEARING LOW DEVELOPING ACROSS THE CENTRAL PLAINS STATES. SEVERAL
WARMER NIGHTS ARE FIGURED WITH MID 40S FOR LOWS FRIDAY NIGHT...NEAR
50F SATURDAY NIGHT AND AGAIN SUNDAY NIGHT. THE LATEST TREND IS TO
MINIMIZE THE POTENTIAL FOR THUNDERSTORM ACTIVITY UNTIL THE SFC LOW
AND 500MB TROUGH GET A BIT CLOSER TO THE CWA...AROUND OR AFTER THE
SUNDAY TIME PERIOD. EXPECT THE ELONGATED LOW STRETCHING FROM
NORTHEAST MN TO N TX AT 18Z SUNDAY /ECMWF FARTHEST EAST/ TO
CONSOLIDATE OVER WESTERN UPPER MICHIGAN SUNDAY EVENING. THE 12Z GFS
DOES NOT BRING THE LOW TO WESTERN UPPER MI UNTIL TUESDAY. NEEDLESS
TO SAY THIS WILL BE A SLOW MOVING SYSTEM...WITH SEVERAL ROUNDS OF
PRECIP ROTING INTO THE REGION. WILL GO WITH A MODEL CONSENSUS BEYOND
SUNDAY...GIVEN THE LARGER DISCREPANCIES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 139 AM EDT WED MAY 15 2013
VFR CONDITIONS SHOULD PREVAIL AT ALL THREE TAF SITES THROUGH THE
FORECAST PERIOD. WILL GET GUSTY THROUGH THE MORNING AT ALL SITES.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 422 PM EDT TUE MAY 14 2013
SOUTHERLY FLOW WAS INCREASING AHEAD OF A LOW PRESSURE SYSTEM MOVING
EAST THROUGH SOUTHERN CANADA. WINDS INCREASE TO 25 KTS TONIGHT INTO WED
BUT WILL BE LIMITED AS LOW LEVEL WARM AIR ADVECTION RESULTS IN
INCREASING STABILITY. WINDS ARE EXPECTED TO REMAIN BELOW
30KTS LATER THIS WEEK AND INTO THE WEEKEND. AFTER COOL AND WINTRY
WEATHER FOR THE SPRING SO FAR...SUMMERTIME WEATHER IS BECOMING MORE
COMMON. THUNDERSTORMS ARE POSSIBLE TONIGHT AND ENDING BY
EARLY WEDNESDAY. ANOTHER ROUND OF THUNDERSTORMS WILL BE POSSIBLE
WEST ON SATURDAY/SATURDAY NIGHT...AND ACROSS ALL OF LAKE SUPERIOR
SUNDAY THROUGH MONDAY MORNING.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FIRE WEATHER WATCH FROM 1 PM EDT /NOON CDT/ THIS AFTERNOON
THROUGH THIS EVENING FOR MIZ002-004>006-009>014-084-085.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS DULUTH MN
139 AM CDT WED MAY 15 2013
.AVIATION...06Z TAF ISSUANCE.
HIGH PRESSURE WILL BRING VFR CONDITIONS FOR THE OVERNIGHT
HOURS...ALONG WITH SOME GUSTY WINDS BEHIND A DEPARTING COLD FRONT.
THE WINDS WILL LOSE THEIR GUSTS FOR THE MOST PART OVERNIGHT...BUT
WILL PICK UP AGAIN ON WEDNESDAY WITH DAYTIME HEATING. THERE COULD
ALSO BE A FEW SHOWERS DEVELOPING AS A WEAK SYSTEM DROPS ACROSS THE
REGION. THE SHOWERS WILL RESULT IN ERRATIC WINDS WITH THE PASSAGE
OF THE SHOWERS.
&&
.PREV DISCUSSION... /ISSUED 922 PM CDT TUE MAY 14 2013/
UPDATE...HAS BEEN A BUSY EVENING PROVIDING WEATHER SUPPORT FOR
THE WILDFIRE OVER THE EASTERN DOUGLAS COUNTY/WESTERN BAYFIELD
COUNTY LINE AREA. THE PRECIPITATION MAINLY STAYED NORTH OF THE CWA
THIS AFTERNOON AND EVENING. THE BIG STORY IS DEFINITELY THE
WILDFIRE...WHICH DEVELOPED RAPIDLY AND RESULTED IN ONGOING
EVACUATIONS. TEMPERATURES APPROACHED 90 DEGREES IN THAT AREA THIS
AFTERNOON WITH GUSTY SOUTHWEST WINDS. THE BIG CONCERN WAS THE
PASSAGE OF A COLD FRONT...WHICH SHIFTED WINDS TO THE WEST DURING
THE EVENING. FORTUNATELY THE INTENSE WINDS THAT MOVED ACROSS MUCH
OF MN DID NOT MAKE IT TOO FAR INTO WI BEFORE WINDS STARTED TO
DIMINISH THIS EVENING. THE DLHWRF...RAP AND HRRR ALL HAD A REALLY
GOOD HANDLE ON THE WINDS AND WE DETAILED THAT IN A COUPLE UPDATES
TO THE FIRE WEATHER SPOT FORECAST.
PREV DISCUSSION... /ISSUED 700 PM CDT TUE MAY 14 2013/
AVIATION.../00Z TAF ISSUANCE/
A COLD FRONT WILL MOVE ACROSS THE NORTHLAND TONIGHT...RESULTING IN
VFR CONDITIONS BUT GUSTY WESTERLY WINDS.
PREV DISCUSSION... /ISSUED 341 PM CDT TUE MAY 14 2013/
SHORT TERM...SFC FRONT LOCATED JUST WEST OF CWA AS OF MID
AFTERNOON. INITIAL CONVECTIVE AREA HAS SHIFTED WELL EAST OF CWA
WITH STRONG WARM ADVECTION OCCURRING. MAX TEMPS HAVE REACHED MID
TO UPPER 80S ACROSS SWRN AND SRN MN CWA... AND LOW 80S INTERIOR
WISC ZONES. MID 40S ARE COMMON ALONG LAKE SUPERIOR AS ONSHORE FLOW
PREVAILS DUE TO LARGE THERMAL GRADIENT. AHEAD OF FRONT A RELATIVE
MOIST AXIS EXISTS FROM KOOCH COUNTY SOUTH TO CASS COUNTY WITH
DEWPOINTS MID 40S TO 50. CONVECTION TRYING TO ORGANIZE ACROSS NRN
KOOCH INTO ONTARIO AS AN AREA OF MUCAPE NEAR 500 J/KG HAS
DEVELOPED. HAVE KEPT LOW POPS ALONG BORDERLAND INTO ARROWHEAD
UNTIL FROPA LATE TODAY OR THIS EVENING. REMOVED POPS OVER WISC AS
CONVECTIVE INHIBITION APPEARS TO BE TOO STRONG.
TONIGHT...FRONTAL SYSTEM WILL USHER IN GUSTY WEST AND NORTHWEST
WINDS THIS EVENING. WINDS COULD BE STRONG OVER NRN HALF OF MN CWA
THROUGH MID EVENING. MIXING POTENTIAL SHOULD CONTINUE OVER MOST OF
THE CWA THROUGH THE NIGHT SO MAY HAVE TO WATCH OVERNIGHT MINS FOR
COLD BIAS.
TOMORROW...A PLEASANT DAY AHEAD IN TERMS OF SUNSHINE AND MILD
READINGS. GUSTY WINDS WILL DEVELOP BY MID MORNING AS MOMENTUM
TRANSFER OCCURS IN A LOW SHEAR BDRY LYR. FIRE DANGER INCREASING
OVER ARROWHEAD AND WISC AS LOW RH/WARM AIR COMBINE TO INCREASE
THREAT. LIMITING FACTOR WOULD APPEAR TO BE SUFFICIENT WINDS.
LONG TERM [WEDNESDAY NIGHT - MONDAY]...
THE BEGINNING OF THE PERIOD LOOKS DRY AS HIGH PRESSURE OVER ONTARIO
AND THE GREAT LAKES HELP PROMOTE DRY AND RELATIVELY CLEAR WEATHER
FOR WEDNESDAY NIGHT AND THURSDAY. THERE IS A REMOTE POSSIBILITY OF
PCPN WEDNESDAY NIGHT DUE TO A POTENTIAL STALLED TRAILING SECONDARY
COLD FRONT IN THE WAKE OF THE LOW PRESSURE SYSTEM MOVING THROUGH
TODAY. HOWEVER...SINCE THIS SEEMS SO REMOTE...KEPT THE WEDNESDAY
NIGHT FORECAST DRY.
IT STILL LOOKS LIKE THURSDAY NIGHT AND THROUGH THE WEEKEND WILL BE
RATHER ACTIVE WITH PERIODS OF SHOWERS AND THUNDERSTORMS AS A
MID/UPPER LEVEL RIDGE MOVES INTO AND THROUGH THE PLAINS AND UPPER
MIDWEST. THE MOST ACTIVE PERIOD MAY BE LATE IN THE WEEKEND AND EARLY
NEXT WEEK WHEN A STRONG LOW PRESSURE SYSTEM POSSIBLY MOVES THROUGH
THE UPPER MIDWEST. DETAILS ARE HARD TO DETERMINE DUE TO SIGNIFICANT
DIFFERENCES BETWEEN EACH MODEL...AND FROM RUN TO RUN...BUT THE
OVERALL THEME OF A PROLONGED WET PERIOD LOOKS SIMILAR. AN OPEN GULF
OF MEXICO WILL ALLOW PLENTY OF MOISTURE TO WORK ITS WAY NORTH TO THE
UPPER MIDWEST. THE NORTHLAND COULD RACK UP SIGNIFICANT AMOUNTS OF
RAINFALL OVER THE SPAN OF SEVERAL DAYS...POSSIBLY MORE THAN A FEW
INCHES IN AREAS. THIS COULD RESULT IN RISES ALONG AREA STREAMS AND
RIVERS.
TEMPERATURES WILL LIKELY BE ABOVE NORMAL FOR THURSDAY AND
FRIDAY...AND THEN TREND TOWARDS NORMAL INTO EARLY NEXT WEEK.
AVIATION.../18Z TAF ISSUANCE/
MOSTLY CLEAR SKIES AND VFR CONDITIONS ARE RETURNING TO NE
MINNESOTA AND NW WISCONSIN EARLY THIS AFTERNOON IN THE WAKE OF
MORNING RAIN SHOWERS THAT MOVED THROUGH THE REGION. THE WINDS WILL
INCREASE THIS AFTERNOON AS A COLD FRONT IN THE FAR NW MINNESOTA
AND THE EASTERN DAKOTAS APPROACHES THE NORTHLAND. THERE IS A SMALL
CHANCE OF SHOWERS AND STORMS WITH THE PASSAGE OF THE COLD FRONT
LATER THIS AFTERNOON. THE CANADIAN BORDER AND KINL AREA HAVE THE
GREATEST CHANCE OF SEEING STORMS...SO I KEPT THE TEMPO GROUP AT
KINL FOR -TSRA. I THINK IT IS VERY UNLIKELY THAT
KBRD/KHYR/KDLH/KHIB WILL SEE ANY STORMS...BUT WE WILL NEED TO KEEP
AN EYE ON STORM DEVELOPMENT ALONG THE COLD FRONT. THERE MAY A
BRIEF PERIOD OF STRONG W WINDS OF 15 TO 20 KNOTS WITH GUSTS UP TO
30 KNOTS AT KBRD/KINL/KHIB LATE THIS AFTERNOON AND EARLY THIS
EVENING IN THE WAKE OF THE COLD FRONT.
&&
.POINT TEMPS/POPS...
DLH 72 47 66 45 / 0 0 0 10
INL 71 41 70 44 / 0 10 0 20
BRD 76 48 76 51 / 0 0 10 30
HYR 74 45 75 47 / 0 0 10 20
ASX 72 44 65 43 / 0 0 0 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
AVIATION...DAP/MELDE
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1225 AM CDT WED MAY 15 2013
.UPDATE...
ISSUED AT 1225 AM CDT WED MAY 15 2013
THE MAIN CHANGE WITH THIS ESTF UPDATE WAS TO INCREASE CLOUD COVER
TO BETTER DEPICT CURRENT IR SATELLITE. SOME MINOR ADJUSTMENTS WILL
BE NEEDED AS THE NGT PROGRESSES AS CLOUDS HAVE A GENERAL THINNING
TREND THAT WILL NOT BE EASY TO FORESEE MUCH BEYOND A COUPLE HRS.
WE ARE NOTING NEW TSTMS GOING UP JUST W OF THE FCST AREA. FOR NOW
THE FCST IS DRY THE REST OF TNGT AND THE 03Z HRRR KEEPS S-CNTRL
NEB DRY. HOWEVER...WE/VE ALSO SEEN COOLING CLOUD TOPS OVER NRN KS
AND THE HRRR DOES DVLP SOME SHWRS. FOR NOW WE/LL CONTINUE TO
MONITOR. WE WILL ALSO NEED TO WATCH FOR ISOLATED HEATBURSTS.
UPDATE ISSUED AT 824 PM CDT TUE MAY 14 2013
OUTFLOW FROM EARLIER CONVECTION...ALONG WITH DECREASING DIABATIC
HEATING...IS ALLOWING THE RELATIVE HUMIDITY TO CLIMB ACROSS THE
ENTIRE CWA AT THIS HOUR. IN ADDITION...THE SURFACE WIND IS
DECREASING IN INTENSITY. THESE TRENDS ARE EXPECTED TO CONTINUE
THROUGH THE REST OF THE EVENING AND AS A RESULT...THE RED FLAG
WARNING HAS BEEN CANCELLED.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 401 PM CDT TUE MAY 14 2013
FORECAST IS PRETTY MUCH ON TRACK. THE EXPECTED COLD FRONT IS SLICING
SOUTHEAST ACROSS THE CWA WITH CONVECTION ALREADY TRYING TO FIRE
ALONG IT. ANY SHOWERS OR THUNDERSTORMS WILL BE HIGH BASED WITH AN
INVERTED V SOUNDING SCENARIO. THIS MEANS THAT THE LIKELY OUTCOME
WILL BE LOW PRECIPITATION AND GUSTY WIND FROM CONVECTION. SHEAR IS
WEAK AND MOISTURE IS LIMITED...SO ALL ONE WOULD EXPECT IS AN OUTSIDE
CHANCE OF A SEVERE WIND GUSTS WITH THE INVERTED V SOUNDING SIGNATURE.
THE FRONT WILL CONTINUE TO SLIDE SOUTH TONIGHT...BUT ANY INSTABILITY
WILL WANE BY MID EVENING...SO CONVECTION SHOULD FOLLOW SUIT AND DIE
OUT. STILL EXPECT THE FRONT TO STALL JUST SOUTH OF THE CWA FOR
WEDNESDAY. ANY CONVECTION NEAR THE FRONT WILL BE LATE AFTERNOON AT
THE EARLIEST...AND WOULD PROBABLY ONLY AFFECT THE EXTREME SOUTHERN
CWA...SO KEPT CHANCES OF SHOWERS AND THUNDERSTORMS IN THE EXTREME
SOUTH AND VERY LATE IN THE DAY. ALSO...COOLER TEMPERATURES ARE
LAGGING BEHIND THE FRONT...SO INCREASED TEMPERATURES FOR WEDNESDAY
FOR MOST LOCATIONS...EXCEPT PERHAPS ORD...WHICH STANDS A BETTER
CHANCE OF BEING IN COOLER AIR.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 401 PM CDT TUE MAY 14 2013
THE MAIN FOCUS OF THE MID AND LONG TERM PERIODS WILL CENTER AROUND
NUMEROUS CHANCES FOR THUNDERSTORMS...SOME OF WHICH MIGHT END UP
BEING SEVERE. THERE IS PLENTY OF INSTABILITY THROUGHOUT MOST OF THE
PERIOD...ALTHOUGH SEVERAL DAYS LIKELY REMAIN TOO CAPPED.
BEGINNING WEDNESDAY NIGHT...THE UPPER LEVEL LOW WHICH HAS REMAINED
MOSTLY CUT OFF ACROSS THE DESERT SOUTHWEST/NORTHWEST MEXICO REGION
WILL FINALLY SHIFT NORTHEAST ACROSS OKLAHOMA...KANSAS AND MISSOURI.
MODELS ARE IN FAIRLY GOOD AGREEMENT ON THIS TRACK OF THIS LOW
PRESSURE SYSTEM. AT THE SURFACE...IT APPEARS A WARM FRONT WILL
LIKELY LIFT NORTH BEFORE POSSIBLY WASHING OUT ACROSS PORTIONS OF
NEBRASKA. AS A RESULT...INCREASED CLOUD COVER AND CONTINUED AT LEAST
SLIGHT CHANCES FOR POPS INTO SOUTH CENTRAL NEBRASKA AS WELL THURSDAY
MORNING. SREF PROBABILITIES INDICATES AT LEAST SOME CHANCE FOR FOG
DEVELOPMENT...WHICH IS ALSO IN AGREEMENT WITH MODEL SOUNDINGS.
THEREFORE...THREW IN AT LEAST PATCHY FOG ACROSS MUCH OF THE AREA. BY
THURSDAY MORNING...LEFT SLIGHT CHANCES IN ACROSS THE ENTIRE AREA FOR
LINGERING SHOWERS IN THE MORNING BUT EXPECT MOST PLACES TO REMAIN
DRY DURING THAT 6 HOUR PERIOD.
ON THE BACKSIDE OF THE UPPER LEVEL LOW...ANOTHER SHORTWAVE WILL
SLIDE THROUGH THE REGION...POSSIBLY PROVIDING THE BEST CHANCES FOR
PRECIPITATION THURSDAY AFTERNOON. MODELS ARE CONSISTENT WITH THIS
SHORT WAVE TROUGH/PV ANOMALY SHIFTING ACROSS OUR NORTHERN CWA. THERE
IS ALSO DECENT THETA E ADVECTION ACROSS OUR NORTHERN ZONES. THERE
REMAINS PLENTY OF INSTABILITY ACROSS THE AREA ABOUT 1400
J/KG...WHILE 700 MB TEMPERATURES WILL LIKELY BE AROUND 6 CELSIUS.
CERTAINLY CANNOT RULE OUT AN ISOLATED SEVERE THUNDERSTORM...MAINLY
ACROSS WESTERN ZONES.
BY FRIDAY...AN UPPER LEVEL RIDGE WILL BEGIN TO SHIFT ACROSS THE
PLAINS...PROVIDING A MORE THAN LIKELY DRY DAY ACROSS THE PLAINS.
HOWEVER...THAT BEING SAID...MODELS CONTINUE TO INDICATE VERY WEAK
PERTURBATIONS SLIDING ACROSS THE UPPER LEVEL RIDGE FLOW DURING THE
DAY ON FRIDAY. MODELS...SUCH AS THE NAM SOLUTION TRY TO HINT AT SOME
LIGHTER SHOWERS POSSIBLY EVEN DRIZZLE AROUND. DECIDED TO LEAVE IN
SLIGHT CHANCES MAINLY ACROSS KANSAS BEFORE SHIFTING NORTH BY FRIDAY
NIGHT.
A DEEPENING UPPER LEVEL LOW WILL SLOWLY BEGAN TO DEGRADE THE RIDGE
ACROSS THE PLAINS BY FRIDAY NIGHT. AT THE SURFACE....DEVELOPING LOW
PRESSURE ALONG THE ROCKIES....COMBINED WITH DECENT THETA E ADVECTION
WILL PROVIDE AT LEAST A CHANCE FOR PRECIPITATION ACROSS THE WESTERN
ZONES FRIDAY NIGHT INTO SATURDAY. BEST CHANCES FOR PRECIPITATION
WILL COME SATURDAY NIGHT INTO SUNDAY...AS THE UPPER LEVEL LOW PUSHES
INTO THE REGION. INSTABILITY WITH THIS SYSTEM IS PROBABLY THE BEST
IN THE LONG TERM...WITH 4500 TO 5000 J/KG NOSING INTO OUR AREA.
STILL 700 MB TEMPERATURES ON THE ORDER OF 10 TO 12 CELSIUS INDICATES
AT LEAST SOME CAP LINGERING THROUGH SATURDAY NIGHT. 0 TO 6 KM BULK
SHEAR VECTORS ARE ALSO NOT TOO HIGH...WITH ABOUT 20 TO 30 KTS ACROSS
THE REGION. EVEN STILL...THINKING THAT SATURDAY IS LIKELY THE BEST
CHANCE FOR SEVERE DURING THE PERIOD. ALTHOUGH...MODELS REMAIN A BIT
INCONSISTENT ON THIS GIVEN LOW PRESSURE SYSTEM...ESPECIALLY
REGARDING STRENGTH AND TRACK. THE ECMWF SOLUTION IS A BIT FURTHER
NORTH ACROSS THE DAKOTAS AND REMAINS AN OPEN WAVE...WHILE THE GFS
HAS TENDED TO BECOME CLOSED DIRECTLY ACROSS OUR CWA FROM RUN TO RUN.
DEFINITELY SOMETHING TO CONTINUE TO MONITOR.
LINGERING CHANCES FOR PRECIPITATION WILL CONTINUE THROUGHOUT THE
REST OF THE LONG TERM...ON THE BACKSIDE OF THE UPPER LEVEL LOW.
REGARDING TEMPERATURES IN THE PERIOD...MADE ONLY A FEW TWEAKS.
MAINLY LOWERED HIGH TEMPERATURES A FEW DEGREES ON THURSDAY TO
REFLECT CHANGES TO CLOUD COVER AND CHANCES FOR PRECIPITATION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1225 AM CDT WED MAY 15 2013
REST OF TNGT: VFR WITH SCT-BKN 25K FT CIRRUS. NE WINDS WILL
AVERAGE JUST UNDER 10 KTS. SOME MARGINAL LLWS IS POSSIBLE.
WED: VFR WITH SCT MID-LVL CLOUDS POSSIBLE FROM THE REMNANTS OF
SHWR/TSTM ACTIVITY. ENE WINDS 10-15 KTS.
WED NGT THRU 06Z: VFR CIRRUS CIGS. ENE WINDS SETTLE AROUND 5 KTS.
CIG CONFIDENCE: HIGH
VSBY CONFIDENCE: HIGH
WIND CONFIDENCE: HIGH
WX CONFIDENCE: HIGH
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...HALBLAUB
SHORT TERM...HEINLEIN
LONG TERM...SALTZMAN
AVIATION...HALBLAUB
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
411 AM EDT WED MAY 15 2013
.SYNOPSIS...
A WARM AIR MASS WILL REMAIN OVER THE REGION THROUGH THE REST OF THE
WEEK. LIGHT SOUTHWEST WINDS WILL SUPPLY HIGHER HUMIDITY VALUES EACH
DAY THIS PERIOD. A MID LEVEL DISTURBANCE WILL ARRIVE OVER THE REGION
ON THURSDAY AND WILL REMAIN INTO FRIDAY. AN UNSETTLED PATTERN WILL
CONTINUE ACROSS THE REGION THIS WEEKEND THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 410 AM EDT...WILL PUSH NRN NC MTN WINDS UP SLIGHTLY GIVEN
LATEST RUC PROFILES AND OBSERVATIONS FROM BOONE TO WEST JEFFERSON.
THIS WILL KEEP GUSTS JUST BELOW ADVISORY CRITERIA ALONG THE HIGHER
RIDGE TOPS...WITH LESSER GUSTS IN THE LOWER MTN VALLEYS.
OTHERWISE...A FLAT RIDGE WILL PERSIST OVER THE AREA TODAY AS A
CLOSED LOW PRES SYSTEM MOVES SLOWLY E ACROSS THE SOUTHERN PLAINS.
STOUT WESTERLY 850 MB FLOW OVER THE RIDGE AXIS WILL IMPACT THE
HIGHEST ELEVATIONS OF THE NC MTNS THIS MORNING...BUT WITH WINDS
GENERALLY NOT MIXING DOWN TO THE MID SLOPES OR LOWER VALLEYS IN THIS
WARM ADVECTION REGIME. THE WESTERLY FLOW WILL PRODUCE DOWNSLOPE
WARMING EAST OF THE MTNS TODAY...WITH A LEE TROUGH LIKELY
STRENGTHENING. A FEW SREF MEMBERS AS WELL AS THE OPERATIONAL GFS
HAVE ISOLATED SHOWERS LATE TODAY IN THE LEE TROUGH AXIS. MODEL
PROFILES INDICATE FAIRLY DECENT SFC BASED CAPE VALUES AROUND 1000
J/KG. HOWEVER...LOW LEVEL CONVERGENCE IN THE LEE TROUGH SHOULD BE
TOO WEAK TO PROVIDE MUCH TRIGGERING GIVEN THE RELATIVELY HIGH LFC
HEIGHTS. MAX TEMPS WILL SURGE TO 7 TO 10 DEGREES ABOVE NORMAL IN
MOST LOCATIONS THIS AFTN.
THE H5 LOW WILL MEANDER INTO THE MID MS RIVER VALLEY TONIGHT...WITH
ALL ATTENDANT SHORTWAVE ENERGY STAYING W OF THE FORECAST AREA
THROUGH THE PERIOD. EXPECT MAINLY AN INCREASE IN HIGH CLOUDS FROM
THE W OVERNIGHT...WITH MIN TEMPERATURES 1 TO 2 CATEGORIES ABOVE
NORMAL.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
AS OF 225 AM WEDNESDAY...BROAD MID LEVEL RIDGING WILL REMAIN OVER
THE FORECAST AREA BY SUNRISE THURSDAY. DURING THE AFTERNOON AND
EVENING...THE H5 TROUGH WILL RIPPLE ACROSS THE SOUTHERN MISSISSIPPI
RIVER VALLEY...RESULTING IN FALLING HEIGHTS ACROSS THE SOUTHERN
APPALACHIANS. AT THE SFC...A WEST TO EAST FRONT WILL BECOMING
STATIONARY ACROSS THE MID APPALACHIANS AND MID ATLANTIC STATES...WITH
HIGH PRESSURE ACROSS THE SOUTHEAST. FORECAST SOUNDINGS INDICATE
FAIRLY MILD TEMPERATURES BELOW H5 WITH DEEP WEST WINDS. A CONSENSUS
OF MOS GUIDANCE SUPPORTS HIGHS WITHIN THE MTN VALLEYS IN THE LOW 80S
WITH MID TO UPPER 80S EAST...DEWPOINTS IN THE LOW TO MID 50S.
FORECAST SOUNDINGS ALSO INDICATES CIN VALUES BETWEEN 50-100 J/KG
EAST OF THE MTNS. I WILL FORECAST CHC POPS ACROSS THE MTNS FOR
SHRA/TSRA...FAVORING THE TN LINE FOR THE GREATEST COVERAGE. EAST OF
THE MTNS...INHIBITION SHOULD KEEP DEEP CONVECTION LIMITED TO ISO
COVERAGE. CONVECTION IS FORECAST TO SLOWLY ASHE OUT DURING THE
EVENING HOURS. CLOUD COVER AND MILE LLVL THICKNESSES WILL FAVOR MIN
TEMPERATURES AROUND 3 TO 5 DEGREES ABOVE NORMAL.
FRIDAY...THE H5 TROF OR CLOSED LOW IS EXPECTED TO SLIDE OVER THE
FORECAST AREA DURING THE AFTERNOON. SHORT RANGE MODELS SHOW VERY
LITTLE CHANGE IN THE SFC FEATURES FROM THURSDAY.
HOWEVER...INCREASING MOISTURE AND GRADUALLY RISING DEWPOINTS SHOULD
PROVIDE SLIGHT INCREASE IN CONDITIONAL INSTABILITY WITH SHALLOW CIN
LAYER. I WILL FORECAST CHC POPS ACROSS THE NC AND MTN ZONES...SCHC
ELSEWHERE. HIGH TEMPERATURES WILL LIKELY RANGE VERY CLOSE TO
THURSDAY VALUES.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 240 AM WEDNESDAY...MEDIUM RANGE GUIDANCE INDICATES THAT
UNSETTLED ZONAL FLOW WILL REMAIN OVER THE CWA DURING THE
WEEKEND...SHALLOW RIDGING EXPECTED EARLY NEXT WEEK. THE GFS APPEARS
VERY CHAOTIC WITH A FEW PASSAGES OF MCS FEATURES ACROSS KY/TN/NC.
THE ECMWF APPEARS LESS ACTIVE WITH MCS/S...BUT DOES INDICATE A RIPE
ENVIRONMENT FOR DIURNAL CONVECTION. I WILL USE A BLEND OF BOTH
SOLUTIONS...FORECASTING CHC POPS PEAKING DURING THE HEAT OF THE
AFTERNOON...ONLY FADING TO SCHC AT NIGHT...COVERAGE GREATEST OVER
THE MTNS. TEMPERATURES WILL FEATURE LITTLE CHANGE FROM DAY TO
DAY...REMAINING 3 TO 5 DEGREES ABOVE NORMAL.
&&
.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
AT KCLT AND ELSEWHERE...VFR CONDITIONS WILL CONTINUE THROUGH THE TAF
PERIOD. WESTERLY FLOW OVER THE MTNS WILL HELP TO ESTABLISH A LEE
TROUGH E OF THE BLUE RIDGE TODAY...WITH WINDS ADJUSTING TO SW AT THE
FOOTHILLS TAF SITES AS WELL AS KCLT. LOW END GUSTS OF 17 TO 19 KT
ARE EXPECTED WITH PEAK MIXING THIS AFTN. MAINLY FEW TO SCT MID AND
HIGH CLOUDS ARE EXPECTED...BUT HIGH BASED CONVECTIVE CUMULUS MAY
DEVELOP IN THE LEE TROUGH CONVERGENCE AXIS THIS
AFTERNOON...ESPECIALLY FROM KGSP TO KCLT. EXPECT LIGHT SW FLOW
TONIGHT...WITH HIGH CLOUDS INCREASING FROM THE W.
OUTLOOK...VFR CONDITIONS ARE GENERALLY EXPECTED THROUGH THE REST OF
THE WEEK. HOWEVER...SCATTERED AFTN AND EVENING THUNDERSTORMS WILL BE
POSSIBLE FROM THURSDAY THROUGH THE WEEKEND.
CONFIDENCE TABLE...
08-14Z 14-20Z 20-02Z 02-08Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...NED
NEAR TERM...HG
SHORT TERM...NED
LONG TERM...NED
AVIATION...HG
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
428 AM CDT WED MAY 15 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 428 AM CDT WED MAY 15 2013
LINGERING MID LEVEL BOUNDARY AND SOME WEAKLY UNSTABLE 700-500 HPA
LAPSE RATES CREATING SOME ISSUES WITH THE FORECAST EARLY THIS
MORNING. WAVE TOPPING DEVELOPING RIDGE ALOFT AND NUDGING UP AGAINST
NORTHWEST SOUTH DAKOTA ACTING TO INDUCE SOME CROSS FRONTAL FLOW...
AND WEAK REGION OF HIGH BASED LIFT FROM NORTHWEST TO SOUTHEAST ACROSS
THE STATE. MID LEVEL FRONTOGENETIC FORCING REMAINS FAIRLY STRONG
MAINLY ALONG AND NORTH OF I90 THROUGH THE DAY... WEAKENING SOME BY
AFTERNOON AS WAVE MOVES PAST. VERY DRY LOWER ATMOSPHERE IS CERTAINLY
IMPACTING THE POTENTIAL EASTWARD SPREAD AND OVERALL COVERAGE OF
WETTING RAINFALL. THE HRRR KEEP SLIPPING AWAY ON DEVELOPING
PRECIP...PUSHING IT BACK AT LEAST AN HOUR OR TWO WITH SUCCESSIVE RUN
DESPITE THE INCREASING PRESENCE ON RADAR OVER THE LAST HOUR OR TWO.
HIGH RES MODELS SEEM TO HAVE THE RIGHT IDEA...AND SUPPORT FROM LARGER
SCALE DYNAMICS MENTIONED ABOVE. INDICATIONS ON VARIOUS FORECAST
SOUNDING FROM 100 TO 300 J/K ELEVATED INSTABILITY...SO WOULD NOT BE
SURPRISED TO GET A FEW RUMBLES OF HIGH BASED THUNDER...EVEN WITH THE
OVERALL PROBABILITY/ COVERAGE OF PRECIPITATION LIKELY LACKING...AND
AT THIS POINT NOT WARRANTING MUCH MORE THAN A LOWER SCATTERED
MENTION.
SOME CONCERN THAT LINGERING CLOUDS AND ANY EVAPORATIVE EFFECTS WOULD
HAVE AN IMPACT ON TEMPERATURES TODAY...BUT SHOULD START TO GET AT
LEAST A DECENT AMOUNT OF SUNSHINE AFTER MAIN WAVE SHEARS BY TO THE
NORTH...AND LINGERING DIV Q ACROSS THE SOUTH WEAKENS AS WELL. MIXING
CENTERS AROUND THE MID TO UPPER 70S...AND DID NUDGE THIS JUST A BIT
HIGHER FOR THE FAR WEST.
TONIGHT LOOKS TO BE QUIETEST PERIOD OF THE FORECAST...WITH WEAK MID
TO UPPER LEVEL RIDGING OVER THE AREA TONIGHT AHEAD OF NEXT WAVE. NAM
AND GEM ACTUALLY A BIT FASTER IN BRINGING PRECIP CHANCE BACK INTO
OUR SOUTHWEST LATE TONIGHT...HOWEVER BEST FORCING WITH WARM ADVECTION
AND ADVANCING WAVE APPEARS TO REMAIN FOCUSED JUST WEST OF OUR AREA
THROUGH 12Z AND WILL LEAVE TONIGHT DRY AS A RESULT. LIGHT WINDS AND
RELATIVELY DRY AIR MASS WILL ALLOW FOR FAIR AMOUNT OF RADIATIONAL
COOLING...AND LOWS IN THE LOWER 50S LOOK REASONABLE FOR MOST AREAS.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 428 AM CDT WED MAY 15 2013
MESSY PATTERN THROUGHOUT THE LONG TERM PERIOD OF THIS FORECAST...WITH
DIFFICULTY PINPOINTING ANY PERIOD WHICH COULD BE SIGNIFICANTLY DRIER
THAN ANOTHER.
PERIOD STARTS WITH WARM FRONT AND ASSOCIATED WAVE MOVING ACROSS THE
FORECAST AREA THURSDAY/THURSDAY NIGHT. NAM/GEM/ECMWF QUITE BULLISH IN
PRODUCING FAIR AMOUNT OF PRECIP WITH THIS SYSTEM...WHILE THE GFS IS
MUCH DRIER THOUGH STILL INDICATIVE OF SOME PRECIP CHANCE. 15/00Z NAM
SEEMS TO BE SLIGHT OUTLIER IN SPEED WITH WHICH IS TRACKS THE WAVE AND
ASSOCIATED PRECIP TO THE NORTHEAST ON THURSDAY...AND HAVE GENERALLY
FOLLOWED SLOWER IDEA FOR NOW...KEEPING OUR NORTHEAST COUNTIES DRY
UNTIL THURSDAY EVENING. PERSISTENT WARM ADVECTION WILL THEN LEAD TO
INCREASING PRECIP CHANCE THROUGH THE OVERNIGHT HOURS THURSDAY NIGHT.
TEMPERATURES SHOULD BE SEASONABLE WITH HIGHS THURSDAY IN THE MID TO
UPPER 70S. INCREASING MOISTURE/CLOUD COVER WILL HOLD TEMPERATURES UP
IN THE UPPER 50S THURSDAY NIGHT.
MUCH OF FRIDAY/FRIDAY NIGHT COULD AGAIN BE BETWEEN PERIODS OF MORE
WIDESPREAD/ORGANIZED PRECIPITATION...THOUGH EASTERN AREAS COULD SEE
A FEW THUNDERSTORMS LINGER INTO THE MORNING...WHILE THE WEST HAS A
CHANCE OF DEVELOPMENT FRIDAY NIGHT AS RETURN FLOW OF MOISTURE MOVES
INTO CENTRAL SOUTH DAKOTA. WITH WARM FRONT EXPECTED TO BE NORTH OF
THE AREA BY FRIDAY AFTERNOON...AND GENERAL LACK OF PRECIP ALONG WITH
BREEZY SOUTH WINDS...SHOULD SEE DECENT MIXING TO HELP WARM TEMPS INTO
THE MID 80S ACROSS THE WEST. DESPITE WARMER TEMPS AND POTENTIAL FOR
SOME GUSTY WINDS...DO NOT EXPECT SIGNIFICANT FIRE DANGER FRIDAY AS
WE SHOULD HAVE MUCH HIGHER BOUNDARY LAYER MOISTURE WITH EVEN MIXED
OUT DEW POINTS HOLDING IN THE UPPER 50S TO AROUND 60. THAT MOISTURE
ALONG WITH WEAK LOW LEVEL JET WILL HOLD OVERNIGHT LOWS IN THE LOWER
TO MID 60S FOR FRIDAY NIGHT.
SATURDAY INTO SATURDAY NIGHT CONTINUES TO LOOK LIKE MOST FAVORED
PERIOD FOR ORGANIZED PRECIPITATION ACROSS THE REGION...AS BROAD
WESTERN CONUS TROUGH BEGINS TO SHIFT EASTWARD INTO THE PLAINS.
PRECIP SHOULD INITIALLY BE FOCUSED NEAR BOUNDARY ACROSS CENTRAL
SOUTH DAKOTA BY SATURDAY AFTERNOON...WITH THUNDERSTORMS THEN
EXPANDING EASTWARD ACROSS OUR FORECAST AREA SATURDAY NIGHT. THIS
PERIOD CONTINUES TO BE GREATEST THREAT FOR SEVERE WEATHER FOR OUR
FORECAST AREA...WITH STEEP MID LEVEL LAPSE RATES AND DEEP FORCING
AHEAD OF TROUGH BRINGING POTENTIAL FOR HAIL/WIND.
AS IS TYPICAL IN CONVECTIVE SEASON...MODELS NOT SHOWING A GREAT DEAL
OF AGREEMENT IN TIMING/LOCATION OF BOUNDARIES FROM THIS POINT
FORWARD. HOWEVER...THEY HAVE TRENDED TOWARD A FAVORED SOLUTION IN
CLOSING OFF THE UPPER LOW SOMEWHERE IN THE CENTRAL/NORTHERN PLAINS
BY SUNDAY NIGHT/MONDAY...WITH THE LOW THEN PERSISTING ACROSS THIS
REGION THROUGH MUCH OF EARLY NEXT WEEK. THIS LEADS TO POTENTIAL FOR
AT LEAST SCATTERED PRECIPITATION SUNDAY THROUGH TUESDAY...AND HAVE
NOT STRAYED FAR FROM CONSENSUS GRIDS WHICH HOLD ONTO CHANCE RANGE
POPS FOR THE LONGER RANGE. TEMPERATURES SHOWING LESS AGREEMENT LATE
IN THE PERIOD...WITH LATEST ECMWF WRAPPING MUCH COLDER AIR AROUND THE
BACK SIDE OF THE UPPER LOW BY MONDAY AND ESPECIALLY TUESDAY. FOR NOW
WILL STICK WITH SOMEWHAT MORE MILD GFS/CONSENSUS SOLUTION WHICH...
ALTHOUGH COOLER THAN THE MILD TEMPERATURES EXPECTED THROUGH THE
WEEKEND...WILL KEEP HIGHS IN THE 60S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1127 PM CDT TUE MAY 14 2013
VFR CONDITIONS WILL CONTINUE THROUGH 06Z THURSDAY.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...CHAPMAN/JH
LONG TERM...JH
AVIATION...CHAPMAN
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1127 PM CDT TUE MAY 14 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 211 PM CDT TUE MAY 14 2013
FRONT CONTINUES TO MOVE ACROSS THE CWA THIS AFTERNOON. RECORD HEAT
OUT AHEAD OF THE FRONT WITH LOW TO EVEN MID 100S ACROSS NORTHWEST
IOWA AND PORTIONS OF SOUTHWEST MINNESOTA...AND STILL LOW TO MID 90S
BEHIND THE FRONT ACROSS SOUTHEAST SOUTH DAKOTA. WITH DEWPOINTS
MIXING OUT...NOT MUCH IN THE WAY OF INSTABILITY AHEAD OF THE FRONT.
ALTHOUGH THE HRRR AND RUC HAVE CONTINUED TO SHOW SOME ISOLATED
DEVELOPMENT ALONG THE FRONT BY 22Z. GIVEN THAT BOTH OF THESE SHORT
RANGE MODELS ARE DOING A PRETTY GOOD JOB WITH SURFACE TEMPS AND
DEWPOINTS..THINK SOME ISOLATED CONVECTION MAY FIRE AS WE MIX THROUGH
WHATEVER CAP THERE IS. HOWEVER LOOKS LIKE THIS THREAT IS MAINLY
SOUTH AND SOUTHEAST OF OUR CWA...THUS WILL KEEP THE FORECAST DRY
THROUGH THE EVENING. WEAK COLD AIR ADVECTION CONTINUES THROUGH THE
NIGHT...WITH WINDS WEAKENING. THUS WHILE LOWS WILL BE ABOVE
NORMAL...MAY STILL SEE THEM GET DOWN INTO THE LOW TO MID 50S BY
MORNING IN MOST LOCATIONS.
MID LEVEL FRONTAL BOUNDARY LINGERS OVERHEAD TONIGHT INTO
TOMORROW...WITH A WEAK WAVE RIDING OVER THE RIDGE. SO WILL SEE A
REGION OF WEAK LIFT AND DECENT MID LEVEL LAPSE RATES. HOWEVER THETAE
ADVECTION IS PRETTY WEEK...AND LOW LEVELS WILL REMAIN VERY DRY. WILL
PROBABLY SEE SOME ELEVATED CONVECTION FORM ACROSS WESTERN NEBRASKA
AND SOUTH DAKOTA TONIGHT...WHICH WILL TRY TO MOVE EAST TOWARDS OUR
AREA. HOWEVER GIVEN THE ABOVE LIMITATIONS...THINK THE CHANCE OF
MEASURABLE PRECIP IN OUR CWA IS TOO LOW TO MENTION AT THIS TIME.
HOWEVER CAN NOT RULE OUT AN ISOLATED SHOWER OR SOME SPRINKLES
REACHING THE GROUND ANYTIME FROM LATE TONIGHT THROUGH THE DAY
TOMORROW. HIGH TEMPERATURES A BIT TRICKY GIVEN CLOUD COVER
POTENTIAL. BUT FEEL WE WILL SEE PERIODS OF SUN AS WELL...WITH
GENERALLY PARTLY TO AT TIMES MOSTLY SUNNY SKIES. AND RECENTLY WE
HAVE BEEN GETTING WARMER THAN JUST ABOUT EVERY GUIDANCE...SO DESPITE
CLOUD COVER CONCERNS WENT AHEAD AND RAISED HIGHS A COUPLE
DEGREES...GENERALLY IN THE UPPER 70S TO AROUND 80.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 325 PM CDT TUE MAY 14 2013
THE FRONT SOUTH OF THE AREA WILL BEGIN TO MOVE NORTH AS A WARM
FRONT WEDNESDAY NIGHT AND SHOULD BEGIN TO BRING SOME MORE MOIST
AND UNSTABLE AIR INTO THE AREA BY THE END OF THE NIGHT. LOW
TEMPERATURES SHOULD BE NEAR SEASONAL VALUES BEFORE MOST OF THE
HUMID AIR GETS HERE ON THURSDAY. THE THREAT OF THUNDERSTORMS IN
WARM ADVECTION PATTERN NORTH OF THE FRONT MAY BEGIN IN THE SOUTH
LATE WEDNESDAY NIGHT. THIS THREAT SHOULD GENERALLY BE AROUND FOR
THE REST OF THE FORECAST...ALTHOUGH WILL KEEP POPS MINIMAL ON
FRIDAY AS IT LOOKS LIKE THERE MAY BE A BREAK ON THAT DAY. THEN THE
THREAT WILL INCREASE AGAIN FOR THE WEEKEND AS MAIN UPPER TROUGH
APPROACHES...WITH THE PEAK THREAT SATURDAY NIGHT. A SEVERE THREAT
OR MODESTLY HEAVY RAIN SEEMS POSSIBLE OVER THE WEEKEND.
INSTABILITY AND MOISTURE UNCERTAIN WITH IT BEING WELL DISCUSSED
ABOUT THE TOO HIGH GFS DEW POINTS. IN ANY EVENT TEMPERATURES WILL
BE WARM DURING THE DAY BUT EVEN WARMER RELATIVE TO NORMAL AT
NIGHT...OR NO REAL HOT SPELL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1127 PM CDT TUE MAY 14 2013
VFR CONDITIONS WILL CONTINUE THROUGH 06Z THURSDAY.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...CHENARD
LONG TERM...
AVIATION...CHAPMAN
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
355 AM CDT WED MAY 15 2013
.SHORT TERM (TODAY THROUGH THURSDAY)...CONTINUING TO WATCH
CONVECTIVE DEVELOPMENT THIS MORNING. SO FAR TWO MAIN AREAS OF
PRECIP...ONE STAYING NORTH OF THE FORECAST AREA...THE OTHER
LARGELY STAYING SOUTH...BOTH ASSOCIATED WITH AN UPPER LEVEL
SHORTWAVE. THE ACTIVITY TO THE SOUTH IS STARTING TO INCLUDE A
NORTHWARD DRIFT ALONG WITH ITS EASTWARD PROGRESSIONS. CLOUD TOPS
ARE ALSO COOLING ACROSS ZAPATA AND JIM HOGG COUNTIES WITH SOME
HIGHER REFLECTIVITY ACTIVITY DEVELOPING. THIS SHOULD PUSH INTO THE
BRUSH COUNTRY AND COASTAL BEND AS THE MORNING GOES ON. STARTING TO
GET SOME ADDITIONAL DEVELOPMENT INTO THE COASTAL BEND AT THIS
TIME.
MODELS CONTINUE TO INDICATE MOISTURE FLUX CONVERGENCE THROUGH THE
AREA THIS MORNING AS WELL. MOST OF GOES SOUNDER PWAT PRODUCT THIS
MORNING IS CONTAMINATED BY CLOUDS...BUT A FEW PIXELS SHOW UP
INDICATING NEARLY 2 INCH PWATS IN THE AREA. 00HR RUC PWAT ANALYSIS
SHOW AS MUCH AS 2.2 INCHES ALONG THE DEEP SOUTH TEXAS COAST. RUC
FORECAST WOULD SUGGEST AROUND 2 INCH VALUES IN TO OUR AREA IN THE
NEXT FEW HOURS. THESE VALUES WOULD BE AROUND THE +2 STANDARD
DEVIATION VALUES FOR THIS TIME OF YEAR. RUC MAY BE A LITTLE HIGH
WITH THESE NUMBERS THOUGH. GFS AND NAM BOTH ARE JUST ABOVE 1.9
INCHES.
HAVE NOT CHANGED POP FORECAST MUCH FOR TODAY...KEEPING A 40 TO 50
POP FOR EASTERN AREAS DURING THE DAY. UPPER LEVEL ENERGY PUSHES
OUT OF THE AREA LATER THIS AFTERNOON ENDING PRECIP CHANCES. HAVE
JUST A LINGERING 20 POP IN THE EAST AFTER 00Z THIS EVENING. MID
LEVEL WAA WILL THEN INCREASE A CAPPING INVERSION OVER THE AREA
TONIGHT INTO THURSDAY.
TEMPERATURES WARM A BIT TODAY IN THE WEST...BUT PRECIP IN THE EAST
COULD KEEP THE BRUSH COUNTRY AND COASTAL BEND AT OR BELOW
YESTERDAYS TEMPS. ADDITIONALLY...A THICK CLOUD COVER LOOKS TO
PERSIST OVER THE AREA WITH STRATUS MAYBE JUST A COUPLE THOUSAND
FEET UP ALL DAY. BY THURSDAY CLOUDS BEGIN TO CLEAR WEST TO EAST
AND SHOULD ALLOW FOR WARMER TEMPS. LAREDO COULD BE NEAR 100.
&&
.LONG TERM (THURSDAY NIGHT THROUGH TUESDAY)...STRONG CAP IS IN PLACE
ACROSS SOUTH TEXAS LATE THIS WEEK THROUGH EARLY NEXT WEEK. PWATS
DO INCREASE BACK UP THE RIO GRANDE OVER THE WEEKEND TO NEAR 1.5
INCHES. MODELS INDICATE THE TAIL END OF A WEAK SHORTWAVE MOVING OUT
OF MEXICO AND ACROSS SOUTH TEXAS LATE SATURDAY INTO SUNDAY.
CONVECTION MAY FIRE ALONG THE SIERRA MADRE LATE SATURDAY AFTERNOON
AND MOVE TOWARDS THE RIO GRANDE SATURDAY EVENING...BUT STRENGTH OF
CAP OVER THE REGION MAKES CONFIDENCE IN CONVECTION REACHING WESTERN
CWA LOW...AND THEREFORE NO WX CURRENTLY MENTIONED. OTHERWISE LONG
TERM WILL FEATURE WARM AND DRY CONDITIONS ACROSS SOUTH TEXAS WITH
PERIODS OF BREEZY CONDITIONS. 12Z ECMWF HAD BEEN INDICATE WEAK FRONT
APPROACHING NORTHERN CWA LATE TUESDAY (DAY 7) BUT HAS BACKED OFF TO
THE NORTH IN THE 00Z RUN.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 85 73 87 74 90 / 50 20 10 10 10
VICTORIA 83 72 85 74 88 / 50 20 10 10 10
LAREDO 93 73 100 73 99 / 20 10 10 10 10
ALICE 87 70 91 73 91 / 40 10 10 10 10
ROCKPORT 83 74 83 74 84 / 50 20 10 10 10
COTULLA 91 71 97 73 98 / 30 10 10 10 10
KINGSVILLE 87 72 89 74 91 / 40 10 10 10 10
NAVY CORPUS 80 74 84 73 84 / 50 20 10 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
PZ/83...SHORT TERM
JR/76...LONG TERM
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
1235 AM CDT WED MAY 15 2013
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...KBRO RADAR SHOWS MAINLY ISOLATED LIGHT RAIN SHOWERS
ACROSS THE VALLEY WITH MORE DEVELOPING UPSTREAM INTO NORTHERN
MEXICO AS ANOTHER PERTURBATION MOVES ACROSS THAT AREA. THERE ARE MVFR
LOW CLOUDS SNEAKING AROUND UNDERNEATH MID LEVEL DECK WITH HEIGHTS
AROUND 025. SHOWERS SHOULD CONTINUE TO DEVELOP AND MOVE ACROSS
THIS MORNING THEN ANOTHER SHOT OF SHOWERS WEDNESDAY AFTERNOON
BEFORE UPPER LEVEL LOW DEPARTS THE AREA. WINDS WILL INCREASE
TODAY AS LOW PRESSURE DEVELOPS OVER THE HIGH PLAINS WITH GUSTS TO
25 KNOTS POSSIBLE THROUGH THE DAY.
&&
.PREV DISCUSSION... /ISSUED 633 PM CDT TUE MAY 14 2013/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...DUAL CLOUDS DECKS CONTINUE ACROSS SOUTH TEXAS...WITH
LOWER DECK FROM 3000 TO 4000 FEET DRIFTING TO THE NW AND MIDLEVEL
DECK RACING OFF TO THE NE. CLOUD DECK WILL REMAIN THROUGH THE
NIGHT...WITH LOWER DECK SLOWLY LOWERING TO AROUND 2000 BY MORNING.
PROB30 RAIN CHANCES STARTING AT MIDNIGHT AS THE NEXT SYSTEM MOVES
INTO THE REGION...WITH SHOWERS ALREADY SHOWING UP ON RADAR TO THE
SW. OCCASIONAL RAINFALL WILL CONTINUE TOMORROW...MAINLY BEFORE
NOON. RAIN WILL REMAIN LIGHT...WITH ISOLATED LIGHTNING STRIKES
POSSIBLE.
PREV DISCUSSION... /ISSUED 155 PM CDT TUE MAY 14 2013/
SHORT TERM.../TONIGHT THROUGH WEDNESDAY NIGHT/...EVEN THOUGH THE
LATEST RUC13 MODEL RUNS CONTINUE TO SHOW SHOWERS DEVELOPING
ACROSS THE CWA THIS AFTERNOON...RADAR AND SATELLITE IMAGES INDICATE
NOT MUCH IN THE WAY OF RAIN DEVELOPING AS OF YET. SURFACE
INSTABILITY IS MARGINAL ACROSS THE RIO GRANDE VALLEY AND THE CLOUD
COVER MAY BE INHIBITING THE INSTABILITY. IN ADDITION...WATER VAPOR
SAT IMAGES AND NAM80 500MB VORTICITY ANALYSIS INDICATE NEGATIVE VORT
CENTER JUST TO THE WEST OF THE AREA. CURRENT FORECAST THINKING IS
THAT AS THE 500MB LOW ACROSS NORTHWEST MEXICO IS KICKED EASTWARD
WITH THE SHORTWAVE TROUGH MOVING INTO SOUTHERN CALIFORNIA...SHOWERS
AND THUNDERSTORMS WILL DEVELOP LATER THIS AFTERNOON INTO THIS
EVENING ACROSS THE MEXICAN PLATEAU AND MOVE EASTWARD INTO THE
WESTERN PORTIONS OF THE CWA TONIGHT INTO EARLY WEDNESDAY. WITH THAT
SAID...WILL ADJUST TIMING OF POPS TONIGHT INTO WED NIGHT AND KEEP AT
LEAST A CHANCE OF RAIN ACROSS MOST OF THE AREA THROUGH WED
AFTERNOON. RAIN CHANCES SHOULD DIMINISH WED AFTERNOON INTO WED
EVENING AS SUBSIDENCE WILL INCREASE ACROSS SOUTHWEST TX AS THE UPPER
LEVEL LOW MOVES ACROSS NORTHWEST TX WEDNESDAY.
LONG TERM.../THURSDAY THROUGH TUESDAY NIGHT/...
LOW PRESSURE SYSTEM OVER BAJA CA WILL QUICKLY MOVE ACROSS SOUTH
CENTRAL TEXAS WED INTO THU WITH SURFACE HIGH PRESSURE TO THE EAST
MOVING SOUTHWARD OVER THE GULF WATERS AS IT INTERACTS WITH THE LOW
PRESSURE OVER WEST TEXAS. AS THIS SYSTEM LIFTS TO THE NORTHEAST...
THE SURFACE WINDS WILL RETURN TO THE SOUTHEAST ACROSS SOUTH TEXAS
AND THE GRADIENT IN RETURN WILL STRENGTHEN. EXPECT BREEZE CONDITIONS
BETWEEN 20 TO 25 MPH THURSDAY AFTERNOON. MOST OF THE MOISTURE SEEN
IN THE LAST FEW DAYS WILL DROP DRAMATICALLY ACROSS THE AREA WITH THE
BUFF SOUNDING NEAR KBRO SHOWING THE INFILTRATION OF THE DRIER AIR IN
THE UPPER AND MID LEVEL OF THE ATMOSPHERE AND A DROP IN THE PWAT
VALUES TO 1.34 INCHES AND INTO 1.10 INCHES TOWARDS THE WEST. THE
DRIER AIR MASS FROM THE RIDGE BUILDING ACROSS THE WESTERN PLAINS
WILL SET UP THAT DRIER AND WARM PATTERN FOR MOST OF THE LONG TERM
FORECAST. HIGH TEMPERATURES THURSDAY THROUGH SUNDAY WILL BE WARM AND
HUMID REACHING THE MID TO UPPER 90S THROUGH THE WEEK. ANOTHER TROUGH
DIGS SOUTHWARD ALONG BAJA CALIFORNIA AND SWING NORTHEASTWARD INTO
THE CENTRAL PLAINS SATURDAY AND SUNDAY. THE MAIN IMPACT WITH THIS
SYSTEM FOR SOUTH TEXAS WILL BE THE SE WINDS AND THE ABUNDANT WARM
TEMPERATURES ACROSS THE CWA WITH NO CONVECTION AS THE SYSTEM REMAINS
NORTH OF THE CWA. EXPECT SURFACE GRADIENT TO INCREASE WITH BREEZE TO
CONDITIONS THIS WEEKEND.
NEXT WEEK...THE TROUGH WILL CONTINUE TO MOVE NORTHEAST AND STRENGTHEN
ITS SURFACE TROUGH OVER NORTH CENTRAL PLAINS. THIS WILL CONTINUE TO
KEEP THE AREA UNDER SOUTHEAST WINDS ACROSS THE CWA. BY TUESDAY...THE
HIGH PRESSURE ALOFT BUILDS FROM THE SOUTH AND A VERY WEAK GRADIENT
AT THE SURFACE RETURNS. LOW TEMPERATURES FOR MUCH OF THE LONG TERM
FORECAST REMAIN IN THE MID 70S ACROSS THE AREA.
MARINE...TONIGHT THROUGH WEDNESDAY NIGHT...SEAS WERE NEAR 4 FEET WITH
SOUTHEAST WINDS NEAR 10 KNOTS AT BUOY020 EARLY THIS AFTERNOON. WINDS
WILL INCREASE ACROSS THE COASTAL WATERS TONIGHT AS THE PRESSURE
GRADIENT INCREASES ACROSS THE WESTERN GULF OF MEXICO. MODERATE TO
STRONG SOUTHEAST WINDS WILL PREVAIL TONIGHT WITH SCEC CONDITIONS
LIKELY OFFSHORE. THE SCEC CONDITIONS WILL PERSIST WEDNESDAY INTO WED
NIGHT...ESPECIALLY OFFSHORE...AS THE PRESSURE GRADIENT REMAINS
STRONG ACROSS THE LOWER TEXAS COAST.
THURSDAY THROUGH TUESDAY...
THE UPPER LEVEL SYSTEM OVER THE BAJA CA WILL FINALLY BEGIN TO MOVE
NORTHEAST WEDNESDAY INTO THURSDAY LIMITING THE AREA OF ANY
CONVECTION. THE SURFACE HIGH PRESSURE OVER THE SOUTHEAST PLAINS WILL
BEGIN TO SHIFT SOUTH OVER THE GULF WATERS SHIFTING WINDS ACROSS THE
GULF TOWARDS THE SE. WINDS WILL INCREASE THURSDAY AFTERNOON WITH
POSSIBLE SCA FOR MUCH OF THE DAY AND EARLY EVENING AS WINDS INCREASE.
THIS SE FLOW WILL PREVAIL FOR MUCH OF THE LONG TERM FORECAST BUT WILL
WEAKEN BY NEXT WEEK. SEAS WILL BE BETWEEN 4 TO 5 FEET OVER THE GULF
WATERS AS THERE WILL BE A LONG DURATION FETCH OVER THE GULF. THE UPPER
AND LOWER FLOW WILL WEAKEN AND KEEP THE WAVE HEIGHT 5 FEET OR LESS.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
55/68
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1121 PM MDT TUE MAY 14 2013
.UPDATE...
ISSUED AT 738 PM MDT TUE MAY 14 2013
ISOLATED SHOWERS AND THUNDERSTORMS CONTINUE OVER THE NORTHERN
NEBRASKA PANHANDLE EARLY THIS EVENING WHILE MOST OF THE SHOWER AND
THUNDERSTORM ACTIVITY HAS DIED OFF OVER THE REST OF THE FORECAST
AREA. SHOWERS AND THUNDERSTORMS HAVE PRODUCED GUSTY WINDS.
TORRINGTON REPORTED A GUST OF 47 KTS WHILE THE ALLIANCE ASOS HIT
49 KTS. THE WIND GUST THREAT WILL QUICKLY SUBSIDE THIS EVENING AS
SHOWERS AND THUNDERSTORMS DIE OFF AND MOVE EAST OF THE AREA.
&&
.SHORT TERM...(TONIGHT THROUGH WEDNESDAY NIGHT)
ISSUED AT 234 PM MDT TUE MAY 14 2013
WIDESPREAD CUMULUS HAVE DEVELOPED ALONG THE SOUTHERN ZONES THIS
AFTERNOON IN A VERY DEEP BOUNDARY LAYER. RADAR IS SHOWING SOME
WEAK SHOWERS OUT THERE...HOWEVER ITS PROBABLY MOSTLY VIRGA WITH
GUSTY WINDS. THIS ISOLATED SHOWER ACTIVITY WILL LIKELY CONTINUE
INTO THE EVENING AS THE RUC SHOWS AROUND 100-200 J/KG OF CAPE
THROUGH AROUND 03Z. LAPS ANALYSIS SHOWS A WEAK FRONT LOCATED FROM
DOUGLAS TO SIDNEY WITH HIGHER LLVL MOISTURE (DEWPOINTS IN THE 40S)
BEHIND IT AND THE MUCH DRIER AIR TO THE SOUTH OF IT. THE MODELS
HAVE THIS BOUNDARY PUSHING TO THE SOUTHWEST OVERNIGHT AND STALLING
ALONG THE LARAMIE RANGE IN THE MORNING. BOTH THE GFS AND NAM SHOW
SOME IMPRESSIVE LLVL MOISTURE BEING ADVECTED IN ON EAST-TO-
SOUTHEAST WINDS BY THE MORNING. INCREASED DEWPOINTS INTO THE LOW-
TO-MID 40S OVER THE PLAINS OF SOUTHEAST WY FROM WEDNESDAY MORNING
THROUGH THE AFTERNOON.
THE COMBINATION OF HIGHER LLVL MOISTURE AND SLIGHTLY COOLER
MIDLEVEL TEMPS ON WEDNESDAY AFTERNOON WILL RESULT IN GOOD SFC
INSTABILITY ALONG AND EAST OF THE LARAMIE RANGE. THE GFS AND NAM
BOTH SHOW LIFTED INDICES OF -3C TO -5C WHICH TRANSLATES INTO
1000-1250 J/KG OF CAPE. THE TREND OF THE MODELS HAS BEEN TO
INCREASE CONVECTIVE POTENTIAL AND QPF FOR WEDNESDAY AFTERNOON AND
EVENING. FOR THIS REASON...UP POPS INTO THE CHANCE CATEGORY OVER
THE MTNS AND PLAINS. THE DEEP LAYER SHEAR DOES NOT LOOK IMPRESSIVE
OVER THE SOUTHERN ZONES (AROUND 20 KTS)...HOWEVER FURTHER TO THE
NORTH ACROSS CONVERSE/NIOBRARA COUNTIES THE MIDLEVEL WINDS ARE
STRONGER AND 0-6KM SHEAR APPROACHES 40 KTS. SO IT LOOKS LIKE THAT
WILL BE THE REGION TO MONITOR FOR STRONGER STORMS WITH SOME SMALL
HAIL POTENTIAL. THE STORMS THAT DEVELOP OVER THE LARAMIE RANGE IN
THE EARLY AFTERNOON WILL PROGRESS EASTWARD INTO PORTIONS OF THE
WESTERN NEBRASKA PANHANDLE BY THE EARLY EVENING. TEMPS WILL BE
AROUND 10 DEGREES COOLER ON WEDNESDAY WITH THE MOIST SE SFC WINDS
AND GREATER CLOUD COVER.
.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 234 PM MDT TUE MAY 14 2013
THURSDAY...WEAK SHORTWAVE RIDGING ALOFT. WILL SEE ISOLATED AFTERNOON
AND EVENING THUNDERSTORMS...PRIMARILY ORIENTED ALONG THE SURFACE
TROUGH AXIS FROM EASTERN WYOMING SOUTHWARD THROUGH EASTERN COLORADO.
FRIDAY...FLOW ALOFT BACKS TO SOUTHWEST IN ADVANCE OF NEXT SHORTWAVE
TROUGH ALOFT. QUITE WARM WITH A DECENT LOW LEVEL THERMAL RIDGE
ORIENTED NORTH TO SOUTH ALONG A DECENT SURFACE TROUGH OVER OUR
COUNTIES. ISOLATED AFTERNOON AND EVENING THUNDERSTORMS ALONG A LOW
LEVEL CONVERGENCE AXIS FROM CASPER TO CHADRON TO SIDNEY...WITH AREAL
COVERAGE OF THUNDERSTORMS MINIMIZED BY WARM TEMPERATURES ALOFT
PROVIDING SIGNIFICANT CONVECTIVE INHIBITION...CIN.
SATURDAY...DECENT NEGATIVELY TILTED SHORTWAVE TROUGH ALOFT ROTATES
EASTWARD ACROSS OUR COUNTIES AND ALONG WITH ITS ASSOCIATED PACIFIC
ORIGIN COLD FRONT...EXPECT ISOLATED TO SCATTERED AFTERNOON AND
EVENING THUNDERSTORMS...MOST NUMEROUS NEAR THE MOUNTAINS DUE TO
DIFFERENTIAL HEATING AND OROGRAPHIC EFFECTS.
SUNDAY...A DEFINITE BRITISH ISLES COASTAL FEEL TYPE DAY. BRISK
WINDS...COOLER TEMPERATURES AND ISOLATED TO SCATTERED AFTERNOON AND
EVENING SHOWERS AND THUNDERSTORMS ON TAP WITH NORTHWEST FLOW ALOFT
AND ENOUGH LOW AND MID LEVEL MOISTURE TO BE LIFTED BY DAYTIME
HEATING EFFECTS AND CYCLONIC FLOW ALOFT. LOW LEVEL DOWNSLOPE WINDS
WILL PRODUCE A RAIN SHADOW EFFECT FROM WHEATLAND TO CHEYENNE AND
MINIMIZE PRECIPITATION COVERAGE.
MONDAY...REFRESHINGLY COOL START TO THE TRADITIONAL WORKWEEK IN THE
WAKE OF THE RELATIVELY STRONG SHORTWAVE TROUGH PASSAGE AND WITH COOL
NORTH WINDS IN USHERING IN RELATIVELY COOL CANADIAN AIR. ISOLATED
AFTERNOON SHOWERS AND THUNDERSTORMS. TEMPERATURES WILL STILL BE NEAR
NORMAL THOUGH.
TUESDAY...TRANSITORY SHORTWAVE RIDGE ALOFT MOVES ACROSS OUR COUNTIES
AND ALONG WITH MUCH LESS LOW AND MID LEVEL MOISTURE...ONLY ISOLATED
AFTERNOON AND EVENING THUNDERSTORMS EXPECTED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY EVENING)
ISSUED AT 1121 PM MDT TUE MAY 14 2013
VFR EXPECTED OVER ALL TERMINALS FOR THE MOST PART DURING THE
PERIOD. WIDELY SCATTERED SHOWERS AND A FEW TSTMS EXPECTED TO REFORM
WEDS AFTERNOON WITH BRIEF GUSTY WINDS ASSOCIATED WITH SOME OF THEM.
ACTIVITY WILL DIMINISH DURING THE EVENING HOURS.
&&
.FIRE WEATHER...
ISSUED AT 234 PM MDT TUE MAY 14 2013
RELATIVE HUMIDITY VALUES HAVE DROPPED BELOW 15 PERCENT THIS
AFTERNOON ACROSS MUCH OF THE LOWER ELEVATIONS IN A VERY WARM
AIRMASS. WINDS HAVE BECOME WEAK NORTHERLY OVER THE PANHANDLE
BEHIND A WEAK FRONT...WITH GUSTS GENERALLY BELOW 20 MPH.
TEMPERATURES ON WEDNESDAY ARE EXPECTED TO BE AROUND 10 DEGREES
COOLER WITH SOUTHEAST WINDS ALONG AND EAST OF THE LARAMIE RANGE.
THE INCREASING LOW LEVEL MOISTURE WILL PROMOTE SCATTERED SHOWERS
AND THUNDERSTORMS ON WEDNESDAY AFTERNOON AND EVENING.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...LIEBL
SHORT TERM...FINCH
LONG TERM...RUBIN
AVIATION...RUBIN
FIRE WEATHER...FINCH
AREA FORECAST DISCUSSION
NWS ALBANY NY
950 AM EDT WED MAY 15 2013
.SYNOPSIS...
A WARM FRONT WILL APPROACH TODAY BRINGING RAIN SHOWERS
AND PERHAPS A THUNDERSTORM TO THE AREA...MAINLY DURING THE
AFTERNOON AND EVENING HOURS. THEN A COLD FRONT WITH LIMITED
MOISTURE WILL APPROACH AND MOVE THROUGH THE REGION LATE THURSDAY
INTO THURSDAY EVENING. THE NEXT CHANCE FOR SOME WET WEATHER IS
EXPECTED LATE IN THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM...RADAR/STLT LOOPS INDICATE CLOUDS AND SHOWERS MOVING
IN FASTER THAN PREVIOUSLY FORECAST...AND HAVE ADJUSTED THE
POP/WX/CLOUD GRIDS ACCORDINGLY THIS MORNING. HAVE ALSO RAISED THE
OVERALL POP FOR TODAY TO LIKELY (AROUND 60 PERCENT)...AS RADAR
COVERAGE APPEARS TO SUPPORT SOMEWHAT HIGHER POPS.
.PREVIOUS DISCUSSION...
STRONG SURFACE WARM FRONT AND MID LEVEL THETA-E ADVECTION ARE
RESULTING IN ELEVATED SHOWERS AND SOME THUNDERSTORMS ACROSS THE
GREAT LAKE STATE TRACKING EAST-SOUTHEAST ACROSS LOWER ONTARIO
PROVINCE. PER THE NCEP MODEL SUITE AND HOURLY RAP UPDATES...THE
WARM FRONT WILL APPROACH WESTERN AND CENTRAL NY THIS MORNING WITH
SCATTERED SHOWERS EXPECTED AHEAD OF THIS FEATURE. WE WILL SLOWLY
BRING UP POPS THROUGH THE MORNING HOURS. IT APPEARS THE WARM FRONT
WILL BECOME PINCHED OFF ALONG THE I81 CORRIDOR INITIALLY THEN
SOUTH OF I90 THROUGH THE AFTERNOON HOURS AS THE MAIN SURFACE LOW
TRACKS ALONG THE ST LAWRENCE RIVER VALLEY. THE EML AND ASSOCIATED
MID LEVEL LAPSE RATES ARE EXPECTED TO TRACK ACROSS PA/NJ AND MID
ATLANTIC REGION WHERE THE SWODY1 SEE TEXT REMAINS IN PLACE. SO
WHILE NO SEVERE WEATHER IS EXPECTED TODAY...WITH AN INCREASE IN
THE WIND FIELDS AND HIGHER PWATS ADVECTING INTO THE REGION /AOA
1.30 INCHES/...WOULD NOT BE SURPRISED TO SEE SOME OF THE DEEPER
CONVECTIVE ELEMENTS PRODUCING SUB-SEVERE WIND GUSTS. THE COLD
FRONT /OR OCCLUDED FRONT/ IS EXPECTED TO PASS THROUGH THE HUDSON
VALLEY REGION AROUND SUNSET. THIS WOULD BE THE WINDOW OF
OPPORTUNITY FOR THOSE DEEPER CONVECTIVE ELEMENTS ASSUMING WE ARE
ABLE TO ROOT THOSE SURFACE PARCELS IN THE WARM SECTOR. FOR
NOW...PER THE EXPERIMENTAL REFLECTIVITY FORECASTS...WE WILL KEEP
POPS BELOW LIKELY THRESHOLDS AND WATCH TRENDS THROUGH THE DAY. AS
FOR TEMPERATURES...AFTER A CHILLY START...THE WARMER AIR SHOULD
ASSIST WITH VALLEY TEMPS CLIMBING INTO THE MID-UPPER 60S...WITH
60-65F FOR THE HIGHER TERRAIN.
TONIGHT...THE PASSAGE OF THE FRONT SHOULD BE EAST OF OUR NEW
ENGLAND COUNTIES SHORTLY AFTER SUNSET WITH DRIER AIR ADVECTING
INTO THE REGION. THIS WILL ALLOW FOR CLEARING SKIES AND CLOSE TO
SEASONABLE OVERNIGHT LOWS...MAINLY LOWER TO MIDDLE 40S.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
THURSDAY AND THURSDAY NIGHT...A NARROW WEDGE OF HIGH PRESSURE WILL
MOVE ACROSS THE REGION DURING THURSDAY WITH TRANQUIL CONDITIONS.
HOWEVER...THE WESTERLY WINDS WILL BECOME QUITE BRISK AND GUSTY AS
MIXING LAYER HEIGHTS CLIMB TO AROUND 8-10K FEET. WINDS RESIDING AT
THIS LEVEL ARE EXPECTED TO BE AT OR ABOVE 40KTS. THE HIGHER
TERRAIN AND SOME MESOSCALE IMPACTS FROM FUNNELING DOWN THE MOHAWK
AND INTO THE TACONICS COULD POTENTIALLY BE PROBLEMATIC. THE AIR
COMING OUT OF CANADA WILL NOT BE ESPECIALLY COOL THIS GO
ROUND...WITH H850 TEMPERATURES ONLY COOLING TO AN AVERAGE OF +8C
DURING THE DAY...LOWER-MIDDLE 70S FOR MANY LOCATIONS WITH UPPER
60S ACROSS THE DACKS AND SOUTHERN GREENS.
NCEP MODEL SUITE AND INTERNATIONAL GUIDANCE ARE CONVERGING WITH A
PASSAGE OF A SECONDARY COLD FRONT THURSDAY EVENING. WHILE MOISTURE
WILL REMAIN RATHER MEAGER...CAN NOT RULE OUT A SHOWER OR TWO
ACROSS THE DACKS...LAKE GEORGE SARATOGA REGION AND PORTIONS OF
SOUTHERN VT SO WE WILL HOLD ONTO THE SLIGHT CHANCE POPS.
FRIDAY...HIGH PRESSURE WILL BE STILL BE BUILDING IN FROM JAMES BAY
OF CANADA AS THOSE H850 TEMPS DIP BACK INTO THE LOWER SINGLE
DIGITS. IT SHOULD BE ANOTHER FINE SPRING DAY FILLED WITH MOSTLY
SUNNY SKIES AND A NORTHWEST BREEZE BUT NOT AS STRONG AS THURSDAY.
TEMPERATURES WILL TOP OUT AROUND 70 IN THE HUDSON VALLEY...60S
HIGHER TERRAIN.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
THE FIRST HALF OF THE PERIOD LOOKS RATHER BENIGN...AS A LARGE AREA
OF HIGH PRESSURE BUILDS ACROSS THE REGION FROM THE GREAT LAKES AND
SOUTHEAST CANADA FRIDAY NIGHT INTO SATURDAY. WITH A NORTHWEST FLOW
REGIME...THIS PATTERN SHOULD BRING MAINLY CLEAR AND COOL
NIGHTS...WITH SEASONABLY WARM DAYS AND SOME FAIR WEATHER CUMULUS
BUILDING DURING THE AFTERNOON HOURS. WINDS WILL TURN SOUTHERLY ON
SUNDAY...AS A RETURN FLOW AROUND DEPARTING HIGH PRESSURE OFF THE NEW
ENGLAND COAST DEVELOPS. THIS WILL SIGNIFY THE START OF A WARMING
TREND...BUT THERE COULD BE A FEW EXTRA CLOUDS AROUND AND PERHAPS A
BRIEF SHOWER SUNDAY INTO SUNDAY NIGHT WITHIN THE WARM ADVECTION
REGIME.
OTHERWISE...MODELS IN GOOD AGREEMENT WITH BUILDING AN UPPER LEVEL
RIDGE WITH A SURGE OF WARMTH ACROSS THE REGION MONDAY INTO TUESDAY
OF NEXT WEEK. SOME DIFFERENCES IN THAT THE GFS HAS A FEW WRINKLES
UNDER THE RIDGE WITH A FEW WEAK DISTURBANCES MOVING THROUGH...WHILE
THE ECMWF IS SHOWING MORE OF A CLASSIC UPPER RIDGE WITH A MORE
AMPLIFIED PATTERN. EITHER WAY IT LOOKS LIKE A DECENT WARMUP...BUT
CHANCES FOR RAINFALL ARE MORE UNCERTAIN. WILL MENTION SLIGHT CHANCE
POPS FOR NOW MONDAY INTO MONDAY NIGHT...INCREASING TO CHANCE FOR
TUESDAY AS THE RIDGE IS FORECAST TO START FLATTENING BY THEN.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
VFR CONDITIONS ARE GENERALLY EXPECTED TO PREVAIL THROUGH MUCH OF THE
24 HOUR TAF PERIOD ENDING 12Z THURSDAY. HOWEVER...THERE IS A CHANCE
FOR SOME INTERMITTENT MVFR OR EVEN BRIEF IFR CONDITIONS TODAY
ASSOCIATED WITH SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS. AN
APPROACHING SURFACE WARM FRONT AND UPPER LEVEL DISTURBANCE WILL BE
RESPONSIBLE FOR THE INCREASING CHANCES FOR SHOWERS BY LATE THIS
MORNING OR EARLY AFTERNOON INTO EARLY EVENING. EXPECTING COVERAGE TO
BE SCATTERED...SO WILL CONTINUE TO MENTION VCSH AT ALL THE
TERMINALS. MODELS FORECASTING THE BEST INSTABILITY TO BE DISPLACED
SOUTH OF THE REGION...HOWEVER SOME LIMITED INSTABILITY AND FAIRLY
POTENT DYNAMICS/LIFT COULD RESULT IN SOME THUNDER.
SHOWERS SHOULD SHIFT EAST OF OUR AREA AND INTO NEW ENGLAND THIS
EVENING WITH GRADUALLY IMPROVING CONDITIONS. THERE IS A CHANCE FOR
SOME FOG FORMATION...MAINLY FOR KGFL/KPOU WHERE WINDS WILL BECOME
NEAR CALM OVERNIGHT...WHILE A PERSISTENT BREEZE AROUND 5 KT SHOULD
PRECLUDE FOG FORMING AT KALB/KPSF.
WINDS WILL INCREASE FROM THE SOUTH AROUND 10 TO 15 KT WITH GUSTS
AROUND 20 KT LATE THIS MORNING CONTINUING THROUGH THE EARLY EVENING.
A BOUNDARY WILL MOVE THROUGH AROUND THE 00Z THURSDAY TIME
FRAME...WHICH WILL SHIFT WINDS TO THE WEST.
OUTLOOK...
THU...VFR. NO SIG WX. BREEZY.
FRI-SAT...VFR. NO SIG WX.
SUN...VFR...SLGT CHC -SHRA.
&&
.FIRE WEATHER...
WIND GUSTS UP TO 30 MPH ARE POSSIBLE TODAY...
WIND GUSTS UP TO 40 MPH ARE EXPECTED ON THURSDAY...
THERE WILL BE SCATTERED SHOWERS AND PERHAPS A THUNDERSTORM TODAY
AS A WARM FRONT APPROACHES. MINIMUM RH VALUES TODAY ARE EXPECTED
TO REMAIN IN THE 40 PERCENTILE. SOUTHERLY WINDS OF 10 TO 20 MPH
ARE EXPECTED WITH GUSTS UP TO 30 MPH POSSIBLE.
TONIGHT...DRIER CONDITIONS WITH A GRADUAL REDUCTION IN WIND GUSTS.
MAXIMUM RH VALUES SHOULD REBOUND TO BETWEEN 80 AND 100
PERCENT...ESPECIALLY IN LOCATIONS WHERE PRECIPITATION OCCURRED.
THURSDAY...A BREEZY DRY DAY WITH WESTERLY WINDS AVERAGING 15 TO
25 MPH...WITH GUSTS TO 40 MPH EXPECTED. RH VALUES LOOK TO DROP TO
AN AVERAGE 30 PERCENT. DEPENDING ON GREEN-UP STATUS FIRE WEATHER
HEADLINES MIGHT HAVE TO BE BROACHED. A SHOWER IS POSSIBLE IN THE
ADIRONDACKS AND SOUTHERN GREENS BY LATE IN THE DAY AS A SECONDARY
COLD FRONT APPROACHES. OTHERWISE IT WILL BE MIX OF CLOUDS AND
SUNSHINE.
FRIDAY AND SATURDAY LOOK DRY WITH LESS WIND AND MORE NORMAL
RECOVERIES AT NIGHT.
&&
.HYDROLOGY...
CHANCES OF RAIN SHOWERS AND PERHAPS A THUNDERSTORM WILL INCREASE
TODAY...MAINLY DURING THE AFTERNOON AND EVENING HOURS AS A WARM
FRONT APPROACHES. RAINFALL AMOUNTS WEDNESDAY AND WEDNESDAY NIGHT
ARE GENERALLY EXPECTED TO BE AROUND OR A LITTLE UNDER A QUARTER OF
AN INCH. THIS RAINFALL SHOULD HAVE LITTLE OR NO EFFECT ON
WATERSHEDS IN OUR HYDRO SERVICE AREA /HSA/.
AFTER THAT...MAINLY DRY WEATHER IS EXPECTED THROUGH AT LEAST THE
FIRST HALF OF THE WEEKEND.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.CLIMATE...
THE GROWING SEASON IS UNDERWAY ACROSS THE MID HUDSON VALLEY...GREATER
CAPITAL DISTRICT...LAKE GEORGE SARATOGA REGION AND SOUTHERN
LITCHFIELD COUNTY CONNECTICUT.
START DATES FOR THE REST OF EAST CENTRAL NY AND ADJACENT WESTERN
NEW ENGLAND ARE AS FOLLOWS...
MAY 15TH...THE MOHAWK VALLEY...EASTERN CATSKILLS...TACONICS...
BENNINGTON COUNTY VT...THE BERKSHIRES AND LITCHFIELD HILLS.
MAY 20TH...EASTERN WINDHAM COUNTY VT.
MAY 25TH...THE SOUTHERN ADIRONDACKS AND WESTERN WINDHAM COUNTY VT.
DURING THE GROWING SEASON FREEZE WARNINGS ARE ISSUED WHEN THE
TEMPERATURES ARE FORECAST TO BE 32 DEGREES OR LOWER...AND FROST
ADVISORIES ARE ISSUED WHEN THE TEMPERATURES ARE FORECAST TO BE IN
THE 33 TO 36 DEGREES RANGE.
THE START OF THE GROWING SEASON FOR A GIVEN AREA IS BASED ON THE
MEDIAN DATE OF THE LAST SPRING FREEZE BASED ON 1981-2010 NORMALS AND
IN COORDINATION WITH NEIGHBORING NWS OFFICES.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...BGM
NEAR TERM...GJM
SHORT TERM...BGM
LONG TERM...JPV
AVIATION...JPV
FIRE WEATHER...HWJIV/BGM
HYDROLOGY...BGM
CLIMATE...IAA
AREA FORECAST DISCUSSION
NWS ALBANY NY
659 AM EDT WED MAY 15 2013
.SYNOPSIS...
A WARM FRONT WILL APPROACH TODAY BRINGING RAIN SHOWERS
AND PERHAPS A THUNDERSTORM TO THE AREA...MAINLY DURING THE
AFTERNOON AND EVENING HOURS. THEN A COLD FRONT WITH LIMITED
MOISTURE WILL APPROACH AND MOVE THROUGH THE REGION LATE THURSDAY
INTO THURSDAY EVENING. THE NEXT CHANCE FOR SOME WET WEATHER IS
EXPECTED DURING THE SECOND HALF OF THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM...ALL HEADLINES HAVE BEEN ALLOWED TO EXPIRE.
OTHERWISE...HIGH AND MID LEVEL CLOUDS ARE INCREASING FROM WEST TO
EAST WITH REGIONAL RADAR MOSAIC REVEALING THE LEADING EDGE OF THE
SHOWERS WAS STILL WEST OF I81. EXTRAPOLATION OF THESE SHOWERS /IF
THEY HOLD TOGETHER/ WOULD ARRIVE INTO THE WESTERN COUNTIES TOWARD
14Z AND THE HUDSON RIVER VALLEY REGION TOWARD 16Z. NO OTHER CHANGES
TO THE FORECAST AT THE PRESENT TIME...
STRONG SURFACE WARM FRONT AND MID LEVEL THETA-E ADVECTION ARE
RESULTING IN ELEVATED SHOWERS AND SOME THUNDERSTORMS ACROSS THE
GREAT LAKE STATE TRACKING EAST-SOUTHEAST ACROSS LOWER ONTARIO
PROVINCE. PER THE NCEP MODEL SUITE AND HOURLY RAP UPDATES...THE
WARM FRONT WILL APPROACH WESTERN AND CENTRAL NY THIS MORNING WITH
SCATTERED SHOWERS EXPECTED AHEAD OF THIS FEATURE. WE WILL SLOWLY
BRING UP POPS THROUGH THE MORNING HOURS. IT APPEARS THE WARM FRONT
WILL BECOME PINCHED OFF ALONG THE I81 CORRIDOR INITIALLY THEN
SOUTH OF I90 THROUGH THE AFTERNOON HOURS AS THE MAIN SURFACE LOW
TRACKS ALONG THE ST LAWRENCE RIVER VALLEY. THE EML AND ASSOCIATED
MID LEVEL LAPSE RATES ARE EXPECTED TO TRACK ACROSS PA/NJ AND MID
ATLANTIC REGION WHERE THE SWODY1 SEE TEXT REMAINS IN PLACE. SO
WHILE NO SEVERE WEATHER IS EXPECTED TODAY...WITH AN INCREASE IN
THE WIND FIELDS AND HIGHER PWATS ADVECTING INTO THE REGION /AOA
1.30 INCHES/...WOULD NOT BE SURPRISED TO SEE SOME OF THE DEEPER
CONVECTIVE ELEMENTS PRODUCING SUB-SEVERE WIND GUSTS. THE COLD
FRONT /OR OCCLUDED FRONT/ IS EXPECTED TO PASS THROUGH THE HUDSON
VALLEY REGION AROUND SUNSET. THIS WOULD BE THE WINDOW OF
OPPORTUNITY FOR THOSE DEEPER CONVECTIVE ELEMENTS ASSUMING WE ARE
ABLE TO ROOT THOSE SURFACE PARCELS IN THE WARM SECTOR. FOR
NOW...PER THE EXPERIMENTAL REFLECTIVITY FORECASTS...WE WILL KEEP
POPS BELOW LIKELY THRESHOLDS AND WATCH TRENDS THROUGH THE DAY. AS
FOR TEMPERATURES...AFTER A CHILLY START...THE WARMER AIR SHOULD
ASSIST WITH VALLEY TEMPS CLIMBING INTO THE MID-UPPER 60S...WITH
60-65F FOR THE HIGHER TERRAIN.
TONIGHT...THE PASSAGE OF THE FRONT SHOULD BE EAST OF OUR NEW
ENGLAND COUNTIES SHORTLY AFTER SUNSET WITH DRIER AIR ADVECTING
INTO THE REGION. THIS WILL ALLOW FOR CLEARING SKIES AND CLOSE TO
SEASONABLE OVERNIGHT LOWS...MAINLY LOWER TO MIDDLE 40S.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
THURSDAY AND THURSDAY NIGHT...A NARROW WEDGE OF HIGH PRESSURE WILL
MOVE ACROSS THE REGION DURING THURSDAY WITH TRANQUIL CONDITIONS.
HOWEVER...THE WESTERLY WINDS WILL BECOME QUITE BRISK AND GUSTY AS
MIXING LAYER HEIGHTS CLIMB TO AROUND 8-10K FEET. WINDS RESIDING AT
THIS LEVEL ARE EXPECTED TO BE AT OR ABOVE 40KTS. THE HIGHER
TERRAIN AND SOME MESOSCALE IMPACTS FROM FUNNELING DOWN THE MOHAWK
AND INTO THE TACONICS COULD POTENTIALLY BE PROBLEMATIC. THE AIR
COMING OUT OF CANADA WILL NOT BE ESPECIALLY COOL THIS GO
ROUND...WITH H850 TEMPERATURES ONLY COOLING TO AN AVERAGE OF +8C
DURING THE DAY...LOWER-MIDDLE 70S FOR MANY LOCATIONS WITH UPPER
60S ACROSS THE DACKS AND SOUTHERN GREENS.
NCEP MODEL SUITE AND INTERNATIONAL GUIDANCE ARE CONVERGING WITH A
PASSAGE OF A SECONDARY COLD FRONT THURSDAY EVENING. WHILE MOISTURE
WILL REMAIN RATHER MEAGER...CAN NOT RULE OUT A SHOWER OR TWO
ACROSS THE DACKS...LAKE GEORGE SARATOGA REGION AND PORTIONS OF
SOUTHERN VT SO WE WILL HOLD ONTO THE SLIGHT CHANCE POPS.
FRIDAY...HIGH PRESSURE WILL BE STILL BE BUILDING IN FROM JAMES BAY
OF CANADA AS THOSE H850 TEMPS DIP BACK INTO THE LOWER SINGLE
DIGITS. IT SHOULD BE ANOTHER FINE SPRING DAY FILLED WITH MOSTLY
SUNNY SKIES AND A NORTHWEST BREEZE BUT NOT AS STRONG AS THURSDAY.
TEMPERATURES WILL TOP OUT AROUND 70 IN THE HUDSON VALLEY...60S
HIGHER TERRAIN.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
THE FIRST HALF OF THE PERIOD LOOKS RATHER BENIGN...AS A LARGE AREA
OF HIGH PRESSURE BUILDS ACROSS THE REGION FROM THE GREAT LAKES AND
SOUTHEAST CANADA FRIDAY NIGHT INTO SATURDAY. WITH A NORTHWEST FLOW
REGIME...THIS PATTERN SHOULD BRING MAINLY CLEAR AND COOL
NIGHTS...WITH SEASONABLY WARM DAYS AND SOME FAIR WEATHER CUMULUS
BUILDING DURING THE AFTERNOON HOURS. WINDS WILL TURN SOUTHERLY ON
SUNDAY...AS A RETURN FLOW AROUND DEPARTING HIGH PRESSURE OFF THE NEW
ENGLAND COAST DEVELOPS. THIS WILL SIGNIFY THE START OF A WARMING
TREND...BUT THERE COULD BE A FEW EXTRA CLOUDS AROUND AND PERHAPS A
BRIEF SHOWER SUNDAY INTO SUNDAY NIGHT WITHIN THE WARM ADVECTION
REGIME.
OTHERWISE...MODELS IN GOOD AGREEMENT WITH BUILDING AN UPPER LEVEL
RIDGE WITH A SURGE OF WARMTH ACROSS THE REGION MONDAY INTO TUESDAY
OF NEXT WEEK. SOME DIFFERENCES IN THAT THE GFS HAS A FEW WRINKLES
UNDER THE RIDGE WITH A FEW WEAK DISTURBANCES MOVING THROUGH...WHILE
THE ECMWF IS SHOWING MORE OF A CLASSIC UPPER RIDGE WITH A MORE
AMPLIFIED PATTERN. EITHER WAY IT LOOKS LIKE A DECENT WARMUP...BUT
CHANCES FOR RAINFALL ARE MORE UNCERTAIN. WILL MENTION SLIGHT CHANCE
POPS FOR NOW MONDAY INTO MONDAY NIGHT...INCREASING TO CHANCE FOR
TUESDAY AS THE RIDGE IS FORECAST TO START FLATTENING BY THEN.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
VFR CONDITIONS ARE GENERALLY EXPECTED TO PREVAIL THROUGH MUCH OF THE
24 HOUR TAF PERIOD ENDING 12Z THURSDAY. HOWEVER...THERE IS A CHANCE
FOR SOME INTERMITTENT MVFR OR EVEN BRIEF IFR CONDITIONS TODAY
ASSOCIATED WITH SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS. AN
APPROACHING SURFACE WARM FRONT AND UPPER LEVEL DISTURBANCE WILL BE
RESPONSIBLE FOR THE INCREASING CHANCES FOR SHOWERS BY LATE THIS
MORNING OR EARLY AFTERNOON INTO EARLY EVENING. EXPECTING COVERAGE TO
BE SCATTERED...SO WILL CONTINUE TO MENTION VCSH AT ALL THE
TERMINALS. MODELS FORECASTING THE BEST INSTABILITY TO BE DISPLACED
SOUTH OF THE REGION...HOWEVER SOME LIMITED INSTABILITY AND FAIRLY
POTENT DYNAMICS/LIFT COULD RESULT IN SOME THUNDER.
SHOWERS SHOULD SHIFT EAST OF OUR AREA AND INTO NEW ENGLAND THIS
EVENING WITH GRADUALLY IMPROVING CONDITIONS. THERE IS A CHANCE FOR
SOME FOG FORMATION...MAINLY FOR KGFL/KPOU WHERE WINDS WILL BECOME
NEAR CALM OVERNIGHT...WHILE A PERSISTENT BREEZE AROUND 5 KT SHOULD
PRECLUDE FOG FORMING AT KALB/KPSF.
WINDS WILL INCREASE FROM THE SOUTH AROUND 10 TO 15 KT WITH GUSTS
AROUND 20 KT LATE THIS MORNING CONTINUING THROUGH THE EARLY EVENING.
A BOUNDARY WILL MOVE THROUGH AROUND THE 00Z THURSDAY TIME
FRAME...WHICH WILL SHIFT WINDS TO THE WEST.
OUTLOOK...
THU...VFR. NO SIG WX. BREEZY.
FRI-SAT...VFR. NO SIG WX.
SUN...VFR...SLGT CHC -SHRA.
&&
.FIRE WEATHER...
WIND GUSTS UP TO 30 MPH ARE POSSIBLE TODAY...
WIND GUSTS UP TO 40 MPH ARE EXPECTED ON THURSDAY...
THERE WILL BE SCATTERED SHOWERS AND PERHAPS A THUNDERSTORM TODAY
AS A WARM FRONT APPROACHES. MINIMUM RH VALUES TODAY ARE EXPECTED
TO REMAIN IN THE 40 PERCENTILE. SOUTHERLY WINDS OF 10 TO 20 MPH
ARE EXPECTED WITH GUSTS UP TO 30 MPH POSSIBLE.
TONIGHT...DRIER CONDITIONS WITH A GRADUAL REDUCTION IN WIND GUSTS.
MAXIMUM RH VALUES SHOULD REBOUND TO BETWEEN 80 AND 100
PERCENT...ESPECIALLY IN LOCATIONS WHERE PRECIPITATION OCCURRED.
THURSDAY...A BREEZY DRY DAY WITH WESTERLY WINDS AVERAGING 15 TO
25 MPH...WITH GUSTS TO 40 MPH EXPECTED. RH VALUES LOOK TO DROP TO
AN AVERAGE 30 PERCENT. DEPENDING ON GREEN-UP STATUS FIRE WEATHER
HEADLINES MIGHT HAVE TO BE BROACHED. A SHOWER IS POSSIBLE IN THE
ADIRONDACKS AND SOUTHERN GREENS BY LATE IN THE DAY AS A SECONDARY
COLD FRONT APPROACHES. OTHERWISE IT WILL BE MIX OF CLOUDS AND
SUNSHINE.
FRIDAY AND SATURDAY LOOK DRY WITH LESS WIND AND MORE NORMAL
RECOVERIES AT NIGHT.
&&
.HYDROLOGY...
CHANCES OF RAIN SHOWERS AND PERHAPS A THUNDERSTORM WILL INCREASE
TODAY...MAINLY DURING THE AFTERNOON AND EVENING HOURS AS A WARM
FRONT APPROACHES. RAINFALL AMOUNTS WEDNESDAY AND WEDNESDAY NIGHT
ARE GENERALLY EXPECTED TO BE AROUND OR A LITTLE UNDER A QUARTER OF
AN INCH. THIS RAINFALL SHOULD HAVE LITTLE OR NO EFFECT ON
WATERSHEDS IN OUR HYDRO SERVICE AREA /HSA/.
AFTER THAT...MAINLY DRY WEATHER IS EXPECTED THROUGH AT LEAST THE
FIRST HALF OF THE WEEKEND.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.CLIMATE...
THE GROWING SEASON IS UNDERWAY ACROSS THE MID HUDSON VALLEY...GREATER
CAPITAL DISTRICT...LAKE GEORGE SARATOGA REGION AND SOUTHERN
LITCHFIELD COUNTY CONNECTICUT.
START DATES FOR THE REST OF EAST CENTRAL NY AND ADJACENT WESTERN
NEW ENGLAND ARE AS FOLLOWS...
MAY 15TH...THE MOHAWK VALLEY...EASTERN CATSKILLS...TACONICS...
BENNINGTON COUNTY VT...THE BERKSHIRES AND LITCHFIELD HILLS.
MAY 20TH...EASTERN WINDHAM COUNTY VT.
MAY 25TH...THE SOUTHERN ADIRONDACKS AND WESTERN WINDHAM COUNTY VT.
DURING THE GROWING SEASON FREEZE WARNINGS ARE ISSUED WHEN THE
TEMPERATURES ARE FORECAST TO BE 32 DEGREES OR LOWER...AND FROST
ADVISORIES ARE ISSUED WHEN THE TEMPERATURES ARE FORECAST TO BE IN
THE 33 TO 36 DEGREES RANGE.
THE START OF THE GROWING SEASON FOR A GIVEN AREA IS BASED ON THE
MEDIAN DATE OF THE LAST SPRING FREEZE BASED ON 1981-2010 NORMALS AND
IN COORDINATION WITH NEIGHBORING NWS OFFICES.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...BGM
NEAR TERM...BGM
SHORT TERM...BGM
LONG TERM...JPV
AVIATION...JPV
FIRE WEATHER...HWJIV/BGM
HYDROLOGY...BGM
CLIMATE...IAA
AREA FORECAST DISCUSSION
NWS ALBANY NY
655 AM EDT WED MAY 15 2013
.SYNOPSIS...
A WARM FRONT WILL APPROACH TODAY BRINGING RAIN SHOWERS
AND PERHAPS A THUNDERSTORM TO THE AREA...MAINLY DURING THE
AFTERNOON AND EVENING HOURS. THEN A COLD FRONT WITH LIMITED
MOISTURE WILL APPROACH AND MOVE THROUGH THE REGION LATE THURSDAY
INTO THURSDAY EVENING. THE NEXT CHANCE FOR SOME WET WEATHER IS
EXPECTED DURING THE SECOND HALF OF THE WEEKEND.
&&
.NEAR TERM /TODAY THROUGH TONIGHT/...
AS OF 630 AM...ALL HEADLINES HAVE BEEN ALLOWED TO EXPIRE.
OTHERWISE...HIGH AND MID LEVEL CLOUDS ARE INCREASING FROM WEST TO
EAST WITH REGIONAL RADAR MOSAIC REVEALING THE LEADING EDGE OF THE
SHOWERS WAS STILL WEST OF I81. EXTRAPOLATION OF THESE SHOWERS /IF
THEY HOLD TOGETHER/ WOULD ARRIVE INTO THE WESTERN COUNTIES TOWARD
14Z AND THE HUDSON RIVER VALLEY REGION TOWARD 16Z. NO OTHER CHANGES
TO THE FORECAST AT THE PRESENT TIME...
STRONG SURFACE WARM FRONT AND MID LEVEL THETA-E ADVECTION ARE
RESULTING IN ELEVATED SHOWERS AND SOME THUNDERSTORMS ACROSS THE
GREAT LAKE STATE TRACKING EAST-SOUTHEAST ACROSS LOWER ONTARIO
PROVINCE. PER THE NCEP MODEL SUITE AND HOURLY RAP UPDATES...THE
WARM FRONT WILL APPROACH WESTERN AND CENTRAL NY THIS MORNING WITH
SCATTERED SHOWERS EXPECTED AHEAD OF THIS FEATURE. WE WILL SLOWLY
BRING UP POPS THROUGH THE MORNING HOURS. IT APPEARS THE WARM FRONT
WILL BECOME PINCHED OFF ALONG THE I81 CORRIDOR INITIALLY THEN
SOUTH OF I90 THROUGH THE AFTERNOON HOURS AS THE MAIN SURFACE LOW
TRACKS ALONG THE ST LAWRENCE RIVER VALLEY. THE EML AND ASSOCIATED
MID LEVEL LAPSE RATES ARE EXPECTED TO TRACK ACROSS PA/NJ AND MID
ATLANTIC REGION WHERE THE SWODY1 SEE TEXT REMAINS IN PLACE. SO
WHILE NO SEVERE WEATHER IS EXPECTED TODAY...WITH AN INCREASE IN
THE WIND FIELDS AND HIGHER PWATS ADVECTING INTO THE REGION /AOA
1.30 INCHES/...WOULD NOT BE SURPRISED TO SEE SOME OF THE DEEPER
CONVECTIVE ELEMENTS PRODUCING SUB-SEVERE WIND GUSTS. THE COLD
FRONT /OR OCCLUDED FRONT/ IS EXPECTED TO PASS THROUGH THE HUDSON
VALLEY REGION AROUND SUNSET. THIS WOULD BE THE WINDOW OF
OPPORTUNITY FOR THOSE DEEPER CONVECTIVE ELEMENTS ASSUMING WE ARE
ABLE TO ROOT THOSE SURFACE PARCELS IN THE WARM SECTOR. FOR
NOW...PER THE EXPERIMENTAL REFLECTIVITY FORECASTS...WE WILL KEEP
POPS BELOW LIKELY THRESHOLDS AND WATCH TRENDS THROUGH THE DAY. AS
FOR TEMPERATURES...AFTER A CHILLY START...THE WARMER AIR SHOULD
ASSIST WITH VALLEY TEMPS CLIMBING INTO THE MID-UPPER 60S...WITH
60-65F FOR THE HIGHER TERRAIN.
TONIGHT...THE PASSAGE OF THE FRONT SHOULD BE EAST OF OUR NEW
ENGLAND COUNTIES SHORTLY AFTER SUNSET WITH DRIER AIR ADVECTING
INTO THE REGION. THIS WILL ALLOW FOR CLEARING SKIES AND CLOSE TO
SEASONABLE OVERNIGHT LOWS...MAINLY LOWER TO MIDDLE 40S.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
THURSDAY AND THURSDAY NIGHT...A NARROW WEDGE OF HIGH PRESSURE WILL
MOVE ACROSS THE REGION DURING THURSDAY WITH TRANQUIL CONDITIONS.
HOWEVER...THE WESTERLY WINDS WILL BECOME QUITE BRISK AND GUSTY AS
MIXING LAYER HEIGHTS CLIMB TO AROUND 8-10K FEET. WINDS RESIDING AT
THIS LEVEL ARE EXPECTED TO BE AT OR ABOVE 40KTS. THE HIGHER
TERRAIN AND SOME MESOSCALE IMPACTS FROM FUNNELING DOWN THE MOHAWK
AND INTO THE TACONICS COULD POTENTIALLY BE PROBLEMATIC. THE AIR
COMING OUT OF CANADA WILL NOT BE ESPECIALLY COOL THIS GO
ROUND...WITH H850 TEMPERATURES ONLY COOLING TO AN AVERAGE OF +8C
DURING THE DAY...LOWER-MIDDLE 70S FOR MANY LOCATIONS WITH UPPER
60S ACROSS THE DACKS AND SOUTHERN GREENS.
NCEP MODEL SUITE AND INTERNATIONAL GUIDANCE ARE CONVERGING WITH A
PASSAGE OF A SECONDARY COLD FRONT THURSDAY EVENING. WHILE MOISTURE
WILL REMAIN RATHER MEAGER...CAN NOT RULE OUT A SHOWER OR TWO
ACROSS THE DACKS...LAKE GEORGE SARATOGA REGION AND PORTIONS OF
SOUTHERN VT SO WE WILL HOLD ONTO THE SLIGHT CHANCE POPS.
FRIDAY...HIGH PRESSURE WILL BE STILL BE BUILDING IN FROM JAMES BAY
OF CANADA AS THOSE H850 TEMPS DIP BACK INTO THE LOWER SINGLE
DIGITS. IT SHOULD BE ANOTHER FINE SPRING DAY FILLED WITH MOSTLY
SUNNY SKIES AND A NORTHWEST BREEZE BUT NOT AS STRONG AS THURSDAY.
TEMPERATURES WILL TOP OUT AROUND 70 IN THE HUDSON VALLEY...60S
HIGHER TERRAIN.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
THE FIRST HALF OF THE PERIOD LOOKS RATHER BENIGN...AS A LARGE AREA
OF HIGH PRESSURE BUILDS ACROSS THE REGION FROM THE GREAT LAKES AND
SOUTHEAST CANADA FRIDAY NIGHT INTO SATURDAY. WITH A NORTHWEST FLOW
REGIME...THIS PATTERN SHOULD BRING MAINLY CLEAR AND COOL
NIGHTS...WITH SEASONABLY WARM DAYS AND SOME FAIR WEATHER CUMULUS
BUILDING DURING THE AFTERNOON HOURS. WINDS WILL TURN SOUTHERLY ON
SUNDAY...AS A RETURN FLOW AROUND DEPARTING HIGH PRESSURE OFF THE NEW
ENGLAND COAST DEVELOPS. THIS WILL SIGNIFY THE START OF A WARMING
TREND...BUT THERE COULD BE A FEW EXTRA CLOUDS AROUND AND PERHAPS A
BRIEF SHOWER SUNDAY INTO SUNDAY NIGHT WITHIN THE WARM ADVECTION
REGIME.
OTHERWISE...MODELS IN GOOD AGREEMENT WITH BUILDING AN UPPER LEVEL
RIDGE WITH A SURGE OF WARMTH ACROSS THE REGION MONDAY INTO TUESDAY
OF NEXT WEEK. SOME DIFFERENCES IN THAT THE GFS HAS A FEW WRINKLES
UNDER THE RIDGE WITH A FEW WEAK DISTURBANCES MOVING THROUGH...WHILE
THE ECMWF IS SHOWING MORE OF A CLASSIC UPPER RIDGE WITH A MORE
AMPLIFIED PATTERN. EITHER WAY IT LOOKS LIKE A DECENT WARMUP...BUT
CHANCES FOR RAINFALL ARE MORE UNCERTAIN. WILL MENTION SLIGHT CHANCE
POPS FOR NOW MONDAY INTO MONDAY NIGHT...INCREASING TO CHANCE FOR
TUESDAY AS THE RIDGE IS FORECAST TO START FLATTENING BY THEN.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH MUCH OF THE 24 HOUR
TAF PERIOD ENDING 06Z THURSDAY. HOWEVER...THERE IS A CHANCE FOR SOME
INTERMITTENT MVFR OR EVEN BRIEF IFR CONDITIONS TODAY ASSOCIATED WITH
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS. AN APPROACHING SURFACE
WARM FRONT AND UPPER LEVEL DISTURBANCE WILL BE RESPONSIBLE FOR THE
INCREASING CHANCES FOR SHOWERS FROM LATE THIS MORNING THROUGH THE
AFTERNOON. EXPECTING COVERAGE TO BE SCATTERED...SO WILL MENTION VCSH
AT ALL THE TERMINALS FOR NOW. MODELS FORECASTING THE BEST
INSTABILITY TO BE DISPLACED SOUTH OF THE REGION...HOWEVER SOME
LIMITED INSTABILITY AND FAIRLY POTENT DYNAMICS/LIFT COULD RESULT IN
SOME THUNDER. SHOWERS SHOULD SHIFT EAST OF OUR AREA AND INTO NEW
ENGLAND THIS EVENING.
WINDS WILL INITIALLY BE NEAR CALM...THEN INCREASE FROM THE SOUTH
AROUND 10 TO 15 KT WITH GUSTS NEAR 20 KT LATE THIS MORNING
CONTINUING THROUGH THE EARLY EVENING. A BOUNDARY WILL MOVE THROUGH
AROUND THE 00Z THURSDAY TIME FRAME...WHICH WILL SHIFT WINDS TO THE
WEST.
OUTLOOK...
THU...VFR. NO SIG WX. BREEZY.
FRI-SAT...VFR. NO SIG WX.
SUN...VFR...SLGT CHC -SHRA.
&&
.FIRE WEATHER...
...WIND GUSTS UP TO 30 MPH ARE POSSIBLE TODAY...
...WIND GUSTS UP TO 40 MPH ARE EXPECTED ON THURSDAY...
THERE WILL BE SCATTERED SHOWERS AND PERHAPS A THUNDERSTORM TODAY
AS A WARM FRONT APPROACHES. MINIMUM RH VALUES TODAY ARE EXPECTED
TO REMAIN IN THE 40 PERCENTILE. SOUTHERLY WINDS OF 10 TO 20 MPH
ARE EXPECTED WITH GUSTS UP TO 30 MPH POSSIBLE.
TONIGHT...DRIER CONDITIONS WITH A GRADUAL REDUCTION IN WIND GUSTS.
MAXIMUM RH VALUES SHOULD REBOUND TO BETWEEN 80 AND 100
PERCENT...ESPECIALLY IN LOCATIONS WHERE PRECIPITATION OCCURRED.
THURSDAY...A BREEZY DRY DAY WITH WESTERLY WINDS AVERAGING 15 TO
25 MPH...WITH GUSTS TO 40 MPH EXPECTED. RH VALUES LOOK TO DROP TO
AN AVERAGE 30 PERCENT. DEPENDING ON GREEN-UP STATUS FIRE WEATHER
HEADLINES MIGHT HAVE TO BE BROACHED. A SHOWER IS POSSIBLE IN THE
ADIRONDACKS AND SOUTHERN GREENS BY LATE IN THE DAY AS A SECONDARY
COLD FRONT APPROACHES. OTHERWISE IT WILL BE MIX OF CLOUDS AND
SUNSHINE.
FRIDAY AND SATURDAY LOOK DRY WITH LESS WIND AND MORE NORMAL
RECOVERIES AT NIGHT.
&&
.HYDROLOGY...
CHANCES OF RAIN SHOWERS AND PERHAPS A THUNDERSTORM WILL INCREASE
TODAY...MAINLY DURING THE AFTERNOON AND EVENING HOURS AS A WARM
FRONT APPROACHES. RAINFALL AMOUNTS WEDNESDAY AND WEDNESDAY NIGHT
ARE GENERALLY EXPECTED TO BE AROUND OR A LITTLE UNDER A QUARTER OF
AN INCH. THIS RAINFALL SHOULD HAVE LITTLE OR NO EFFECT ON
WATERSHEDS IN OUR HYDRO SERVICE AREA /HSA/.
AFTER THAT...MAINLY DRY WEATHER IS EXPECTED THROUGH AT LEAST THE
FIRST HALF OF THE WEEKEND.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.CLIMATE...
THE GROWING SEASON IS UNDERWAY ACROSS THE MID HUDSON VALLEY...GREATER
CAPITAL DISTRICT...LAKE GEORGE SARATOGA REGION AND SOUTHERN
LITCHFIELD COUNTY CONNECTICUT.
START DATES FOR THE REST OF EAST CENTRAL NY AND ADJACENT WESTERN
NEW ENGLAND ARE AS FOLLOWS...
MAY 15TH...THE MOHAWK VALLEY...EASTERN CATSKILLS...TACONICS...
BENNINGTON COUNTY VT...THE BERKSHIRES AND LITCHFIELD HILLS.
MAY 20TH...EASTERN WINDHAM COUNTY VT.
MAY 25TH...THE SOUTHERN ADIRONDACKS AND WESTERN WINDHAM COUNTY VT.
DURING THE GROWING SEASON FREEZE WARNINGS ARE ISSUED WHEN THE
TEMPERATURES ARE FORECAST TO BE 32 DEGREES OR LOWER...AND FROST
ADVISORIES ARE ISSUED WHEN THE TEMPERATURES ARE FORECAST TO BE IN
THE 33 TO 36 DEGREES RANGE.
THE START OF THE GROWING SEASON FOR A GIVEN AREA IS BASED ON THE
MEDIAN DATE OF THE LAST SPRING FREEZE BASED ON 1981-2010 NORMALS AND
IN COORDINATION WITH NEIGHBORING NWS OFFICES.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...FROST ADVISORY UNTIL 7 AM EDT THIS MORNING FOR CTZ001-013.
NY...FROST ADVISORY UNTIL 7 AM EDT THIS MORNING FOR NYZ038>040-
047>053-058>061-063>066.
FREEZE WARNING UNTIL 7 AM EDT THIS MORNING FOR NYZ041-043-054-
083-084.
MA...FROST ADVISORY UNTIL 7 AM EDT THIS MORNING FOR MAZ025.
FREEZE WARNING UNTIL 7 AM EDT THIS MORNING FOR MAZ001.
VT...FREEZE WARNING UNTIL 7 AM EDT THIS MORNING FOR VTZ013.
&&
$$
SYNOPSIS...BGM
NEAR TERM...BGM
SHORT TERM...BGM
LONG TERM...JPV
AVIATION...JPV
FIRE WEATHER...HWJIV/BGM
HYDROLOGY...BGM
CLIMATE...IAA
WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS DES MOINES IA
614 AM CDT WED MAY 15 2013
...UPDATED AVIATION DISCUSSION...
.SHORT TERM.../TODAY /...
ISSUED AT 359 AM CDT WED MAY 15 2013
SURFACE HIGH PRESSURE WILL MOVE INTO THE STATE
TODAY AND WILL PROVIDE A MUCH QUIETER DAY ACROSS THE FORECAST
AREA. THERE IS A SMALL POTENTIAL FOR SOME VERY HIGH BASED
SHOWERS AND A STRAY THUNDERSTORM ACROSS NORTHERN IOWA THIS
MORNING...DUE TO SOME WEAK THETA-E ADVECTION AND FORCING BETWEEN
700-500MB. HRRR HAS THE ISOLATED SHOWERS THROUGH 18Z...BUT 00Z NMM
WRF DIMINISHING THE SHOWER ACTIVITY BEFORE ENTERING THE STATE.
LEANED TOWARD THE HRRR AS IT SEEMED TO HAVE A DECENT GRASP ON
CURRENT RADAR TRENDS.
WEAK BOUNDARY ACROSS SOUTHERN IOWA LOOKS TO BE A FOCAL POINT FOR
SOME ISOLATED THUNDERSTORMS THIS AFTERNOON. AGAIN...VERY HIGH BASED
AS VERY MINIMAL MOISTURE BELOW 700MB.
MAX TEMPS TODAY A LITTLE TRICK AS THINK GUIDANCE IS TOO LOW AGAIN
AND FELT CONFIDENT ENOUGH TO TWEAK TEMPS UP TODAY...ESPECIALLY
ACROSS THE SOUTH WHERE THE COOLER AIR DOES NOT REACH THIS AREA
UNTIL THE AFTERNOON. WENT ABOVE GUIDANCE ACROSS THE CENTRAL TO
SOUTHERN PORTIONS OF THE FORECAST AREA...WHICH WAS FAIRLY CLOSE TO
THE MAV MOS GUIDANCE. IN NORTHERN IOWA WENT CLOSER THE THE NAM/MET
MOS GUIDANCE FOR MAX TEMPS.
.LONG TERM.../TONIGHT THROUGH TUESDAY/...
ISSUED AT 359 AM CDT WED MAY 15 2013
RELATIVELY ACTIVE PERIOD THROUGH THE EXTENDED. HIGH PRESSURE WILL
GRADUALLY DEPART TONIGHT INTO THURSDAY AND AS IT DOES...A STALLED
FRONTAL BOUNDARY OVER NORTHERN MISSOURI WILL BEGIN TO LIFT BACK
NORTH INTO IOWA. AS THIS OCCURS...A PLUME OF MOISTURE LIFTING
THROUGH OKLAHOMA AND KANSAS WILL ARRIVE INTO SRN IA. THIS WILL
BRING BACK THE CHANCE FOR THUNDERSTORMS IN THAT REGION. A STRONG
PV ANOMALY OVER SRN NEVADA WILL APPROACH IA LATE THURSDAY AND
THURSDAY NIGHT. PREFER THE FARTHER NORTH NAM/ECMWF SOLUTION OVER
THE LESS ORGANIZED AND FARTHER SOUTH GFS. THIS WOULD PLACE THE
FOCUS FOR ADDITIONAL THUNDERSTORMS OVER NORTHWEST AND NORTH
CENTRAL IOWA. THIS POPS CONTINUE INTO FRIDAY MAINLY OVER THE
NORTH. EXPECT AT THIS POINT THAT POPS MAY BE OVERDONE FOR FRIDAY.
HAVE BEGUN TO TRIM BACK OVER THE CENTRAL AND SOUTH BUT IT MAY VERY
WELL BE MOSTLY DRY MOST LOCATIONS. THE SAME CAN BE SAID FOR FRIDAY
NIGHT WHERE POPS HAVE BEEN DROPPED FOR ALL BUT THE FAR NORTHEAST.
IOWA WILL BE IN THE WARM SECTOR ON SATURDAY AND WHILE LOW POPS
REMAIN...THE CONVECTIVE INHIBITION SHOULD HOLD STRONG MUCH OF THE
DAY. THE PRECIPITATION CHANCES THROUGH THE REMAINDER OF THE PERIOD
ARE MORE COMPLEX. THE INITIAL WAVE TO MOVE INTO THE INTER MOUNTAIN
WEST WILL BE FOLLOWED BY ANOTHER INTENSE PIECE OF ENERGY SATURDAY
NIGHT INTO SUNDAY. LONG RANGE GUIDANCE IS BEGINNING TO FAVOR THE
TWO TO MERGE AND FORM A CLOSED LOW TO THE WEST/NORTHWEST OF THE
AREA. THE FIRST WAVE WILL NUDGE THE UPPER LEVEL RIDGE ENOUGH EAST
SATURDAY NIGHT TO BRING A RETURN FOR PRECIPITATION
CHANCES...MAINLY OVER THE NORTH HOWEVER THE EVOLUTION TO A CLOSE
LOW WILL SLOW THE BOUNDARY ARRIVAL TO LATER SUNDAY INTO MONDAY.
INCREASING SOUTHWEST FLOW OVER THE STATE WILL KEEP THE PERIOD
ACTIVE AND EVENTUALLY SHOULD BRING A SEVERE WEATHER THREAT TO THE
STATE. TEMPERATURES THROUGH THE PERIOD WILL GENERALLY BE ABOVE
SEASONAL VALUES. COOLER ACROSS THE SOUTH ON THURSDAY DUE TO
ENHANCED CLOUD COVER THEN WARMER AGAIN FRIDAY INTO SATURDAY.
&&
.AVIATION...15/12Z
ISSUED AT 612 AM CDT WED MAY 15 2013
VFR CONDITIONS WILL PREVAIL THROUGHOUT THE ENTIRE TAF PERIOD AS
SURFACE HIGH PRESSURE BUILDS INTO THE STATE TODAY. WINDS WILL
GRADUALLY SHIFT TO EAST TODAY AND REMAIN EAST OR VARIABLE THROUGH
THURSDAY MORNING.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...PODRAZIK
LONG TERM...DONAVON
AVIATION...PODRAZIK
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
522 AM CDT WED MAY 15 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 428 AM CDT WED MAY 15 2013
LINGERING MID LEVEL BOUNDARY AND SOME WEAKLY UNSTABLE 700-500 HPA
LAPSE RATES CREATING SOME ISSUES WITH THE FORECAST EARLY THIS
MORNING. WAVE TOPPING DEVELOPING RIDGE ALOFT AND NUDGING UP AGAINST
NORTHWEST SOUTH DAKOTA ACTING TO INDUCE SOME CROSS FRONTAL FLOW...
AND WEAK REGION OF HIGH BASED LIFT FROM NORTHWEST TO SOUTHEAST ACROSS
THE STATE. MID LEVEL FRONTOGENETIC FORCING REMAINS FAIRLY STRONG
MAINLY ALONG AND NORTH OF I90 THROUGH THE DAY... WEAKENING SOME BY
AFTERNOON AS WAVE MOVES PAST. VERY DRY LOWER ATMOSPHERE IS CERTAINLY
IMPACTING THE POTENTIAL EASTWARD SPREAD AND OVERALL COVERAGE OF
WETTING RAINFALL. THE HRRR KEEP SLIPPING AWAY ON DEVELOPING
PRECIP...PUSHING IT BACK AT LEAST AN HOUR OR TWO WITH SUCCESSIVE RUN
DESPITE THE INCREASING PRESENCE ON RADAR OVER THE LAST HOUR OR TWO.
HIGH RES MODELS SEEM TO HAVE THE RIGHT IDEA...AND SUPPORT FROM LARGER
SCALE DYNAMICS MENTIONED ABOVE. INDICATIONS ON VARIOUS FORECAST
SOUNDING FROM 100 TO 300 J/K ELEVATED INSTABILITY...SO WOULD NOT BE
SURPRISED TO GET A FEW RUMBLES OF HIGH BASED THUNDER...EVEN WITH THE
OVERALL PROBABILITY/ COVERAGE OF PRECIPITATION LIKELY LACKING...AND
AT THIS POINT NOT WARRANTING MUCH MORE THAN A LOWER SCATTERED
MENTION.
SOME CONCERN THAT LINGERING CLOUDS AND ANY EVAPORATIVE EFFECTS WOULD
HAVE AN IMPACT ON TEMPERATURES TODAY...BUT SHOULD START TO GET AT
LEAST A DECENT AMOUNT OF SUNSHINE AFTER MAIN WAVE SHEARS BY TO THE
NORTH...AND LINGERING DIV Q ACROSS THE SOUTH WEAKENS AS WELL. MIXING
CENTERS AROUND THE MID TO UPPER 70S...AND DID NUDGE THIS JUST A BIT
HIGHER FOR THE FAR WEST.
TONIGHT LOOKS TO BE QUIETEST PERIOD OF THE FORECAST...WITH WEAK MID
TO UPPER LEVEL RIDGING OVER THE AREA TONIGHT AHEAD OF NEXT WAVE. NAM
AND GEM ACTUALLY A BIT FASTER IN BRINGING PRECIP CHANCE BACK INTO
OUR SOUTHWEST LATE TONIGHT...HOWEVER BEST FORCING WITH WARM ADVECTION
AND ADVANCING WAVE APPEARS TO REMAIN FOCUSED JUST WEST OF OUR AREA
THROUGH 12Z AND WILL LEAVE TONIGHT DRY AS A RESULT. LIGHT WINDS AND
RELATIVELY DRY AIR MASS WILL ALLOW FOR FAIR AMOUNT OF RADIATIONAL
COOLING...AND LOWS IN THE LOWER 50S LOOK REASONABLE FOR MOST AREAS.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 428 AM CDT WED MAY 15 2013
MESSY PATTERN THROUGHOUT THE LONG TERM PERIOD OF THIS FORECAST...WITH
DIFFICULTY PINPOINTING ANY PERIOD WHICH COULD BE SIGNIFICANTLY DRIER
THAN ANOTHER.
PERIOD STARTS WITH WARM FRONT AND ASSOCIATED WAVE MOVING ACROSS THE
FORECAST AREA THURSDAY/THURSDAY NIGHT. NAM/GEM/ECMWF QUITE BULLISH IN
PRODUCING FAIR AMOUNT OF PRECIP WITH THIS SYSTEM...WHILE THE GFS IS
MUCH DRIER THOUGH STILL INDICATIVE OF SOME PRECIP CHANCE. 15/00Z NAM
SEEMS TO BE SLIGHT OUTLIER IN SPEED WITH WHICH IS TRACKS THE WAVE AND
ASSOCIATED PRECIP TO THE NORTHEAST ON THURSDAY...AND HAVE GENERALLY
FOLLOWED SLOWER IDEA FOR NOW...KEEPING OUR NORTHEAST COUNTIES DRY
UNTIL THURSDAY EVENING. PERSISTENT WARM ADVECTION WILL THEN LEAD TO
INCREASING PRECIP CHANCE THROUGH THE OVERNIGHT HOURS THURSDAY NIGHT.
TEMPERATURES SHOULD BE SEASONABLE WITH HIGHS THURSDAY IN THE MID TO
UPPER 70S. INCREASING MOISTURE/CLOUD COVER WILL HOLD TEMPERATURES UP
IN THE UPPER 50S THURSDAY NIGHT.
MUCH OF FRIDAY/FRIDAY NIGHT COULD AGAIN BE BETWEEN PERIODS OF MORE
WIDESPREAD/ORGANIZED PRECIPITATION...THOUGH EASTERN AREAS COULD SEE
A FEW THUNDERSTORMS LINGER INTO THE MORNING...WHILE THE WEST HAS A
CHANCE OF DEVELOPMENT FRIDAY NIGHT AS RETURN FLOW OF MOISTURE MOVES
INTO CENTRAL SOUTH DAKOTA. WITH WARM FRONT EXPECTED TO BE NORTH OF
THE AREA BY FRIDAY AFTERNOON...AND GENERAL LACK OF PRECIP ALONG WITH
BREEZY SOUTH WINDS...SHOULD SEE DECENT MIXING TO HELP WARM TEMPS INTO
THE MID 80S ACROSS THE WEST. DESPITE WARMER TEMPS AND POTENTIAL FOR
SOME GUSTY WINDS...DO NOT EXPECT SIGNIFICANT FIRE DANGER FRIDAY AS
WE SHOULD HAVE MUCH HIGHER BOUNDARY LAYER MOISTURE WITH EVEN MIXED
OUT DEW POINTS HOLDING IN THE UPPER 50S TO AROUND 60. THAT MOISTURE
ALONG WITH WEAK LOW LEVEL JET WILL HOLD OVERNIGHT LOWS IN THE LOWER
TO MID 60S FOR FRIDAY NIGHT.
SATURDAY INTO SATURDAY NIGHT CONTINUES TO LOOK LIKE MOST FAVORED
PERIOD FOR ORGANIZED PRECIPITATION ACROSS THE REGION...AS BROAD
WESTERN CONUS TROUGH BEGINS TO SHIFT EASTWARD INTO THE PLAINS.
PRECIP SHOULD INITIALLY BE FOCUSED NEAR BOUNDARY ACROSS CENTRAL
SOUTH DAKOTA BY SATURDAY AFTERNOON...WITH THUNDERSTORMS THEN
EXPANDING EASTWARD ACROSS OUR FORECAST AREA SATURDAY NIGHT. THIS
PERIOD CONTINUES TO BE GREATEST THREAT FOR SEVERE WEATHER FOR OUR
FORECAST AREA...WITH STEEP MID LEVEL LAPSE RATES AND DEEP FORCING
AHEAD OF TROUGH BRINGING POTENTIAL FOR HAIL/WIND.
AS IS TYPICAL IN CONVECTIVE SEASON...MODELS NOT SHOWING A GREAT DEAL
OF AGREEMENT IN TIMING/LOCATION OF BOUNDARIES FROM THIS POINT
FORWARD. HOWEVER...THEY HAVE TRENDED TOWARD A FAVORED SOLUTION IN
CLOSING OFF THE UPPER LOW SOMEWHERE IN THE CENTRAL/NORTHERN PLAINS
BY SUNDAY NIGHT/MONDAY...WITH THE LOW THEN PERSISTING ACROSS THIS
REGION THROUGH MUCH OF EARLY NEXT WEEK. THIS LEADS TO POTENTIAL FOR
AT LEAST SCATTERED PRECIPITATION SUNDAY THROUGH TUESDAY...AND HAVE
NOT STRAYED FAR FROM CONSENSUS GRIDS WHICH HOLD ONTO CHANCE RANGE
POPS FOR THE LONGER RANGE. TEMPERATURES SHOWING LESS AGREEMENT LATE
IN THE PERIOD...WITH LATEST ECMWF WRAPPING MUCH COLDER AIR AROUND THE
BACK SIDE OF THE UPPER LOW BY MONDAY AND ESPECIALLY TUESDAY. FOR NOW
WILL STICK WITH SOMEWHAT MORE MILD GFS/CONSENSUS SOLUTION WHICH...
ALTHOUGH COOLER THAN THE MILD TEMPERATURES EXPECTED THROUGH THE
WEEKEND...WILL KEEP HIGHS IN THE 60S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 521 AM CDT WED MAY 15 2013
ELEVATED INSTABILITY AND A DISTURBANCE MOVING ACROSS FAR NORTHERN
SOUTH DAKOTA THIS MORNING WILL CONTINUE TO PRODUCE ISOLATED TO
SCATTERED SHOWERS AND A FEW THUNDERSTORMS ACROSS THE AREA. OTHER
THAN THE IMMEDIATE SHORT TERM AROUND KHON...NOT LIKELY TO HAVE A
HIGH ENOUGH PROBABILITY OF THUNDER TO WARRANT MENTION IN THE TAFS.
DESPITE PRECIPITATION...VERY HIGH BASED NATURE WILL MEAN THAT
CONDITIONS SHOULD REMAIN VFR. THE PRECIPITATION SHOULD MOVE OUT
OF THE IMMEDIATE AREA BY 18Z...AND DRY CONDITIONS ARE EXPECTED
THROUGH 12Z THURSDAY. HOWEVER...SCATTERED THUNDERSTORMS SHOULD BE
POISED SOUTHWEST OF THE KHON AREA TOWARD 12Z MOVING FROM ORIGINS
IN WESTERN NEBRASKA AND SOUTHWEST SOUTH DAKOTA.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...CHAPMAN/JH
LONG TERM...JH
AVIATION...CHAPMAN
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
635 AM CDT WED MAY 15 2013
.DISCUSSION...UPDATED FOR 12Z TAFS.
&&
.AVIATION...SHOWERS AND THUNDERSTORMS ARE NOTED AT AND NEAR CRP
AND VCT TAF SITES. LRD AND ALI STILL MAY SEE A FEW SHOWERS IN THE
VICINITY THIS MORNING...BUT MOST OF THE ACTIVITY WILL REMAIN ALONG
THE COAST. MVFR CONDITIONS WILL CONTINUE FOR MOST SITES THROUGH
THE DAY...BUT LRD SHOULD IMPROVE TO VFR. BREEZY CONDITIONS ARE
EXPECTED TO DEVELOP DURING THE DAY.
&&
.PREV DISCUSSION... /ISSUED 355 AM CDT WED MAY 15 2013/
SHORT TERM (TODAY THROUGH THURSDAY)...CONTINUING TO WATCH
CONVECTIVE DEVELOPMENT THIS MORNING. SO FAR TWO MAIN AREAS OF
PRECIP...ONE STAYING NORTH OF THE FORECAST AREA...THE OTHER
LARGELY STAYING SOUTH...BOTH ASSOCIATED WITH AN UPPER LEVEL
SHORTWAVE. THE ACTIVITY TO THE SOUTH IS STARTING TO INCLUDE A
NORTHWARD DRIFT ALONG WITH ITS EASTWARD PROGRESSIONS. CLOUD TOPS
ARE ALSO COOLING ACROSS ZAPATA AND JIM HOGG COUNTIES WITH SOME
HIGHER REFLECTIVITY ACTIVITY DEVELOPING. THIS SHOULD PUSH INTO THE
BRUSH COUNTRY AND COASTAL BEND AS THE MORNING GOES ON. STARTING TO
GET SOME ADDITIONAL DEVELOPMENT INTO THE COASTAL BEND AT THIS
TIME.
MODELS CONTINUE TO INDICATE MOISTURE FLUX CONVERGENCE THROUGH THE
AREA THIS MORNING AS WELL. MOST OF GOES SOUNDER PWAT PRODUCT THIS
MORNING IS CONTAMINATED BY CLOUDS...BUT A FEW PIXELS SHOW UP
INDICATING NEARLY 2 INCH PWATS IN THE AREA. 00HR RUC PWAT ANALYSIS
SHOW AS MUCH AS 2.2 INCHES ALONG THE DEEP SOUTH TEXAS COAST. RUC
FORECAST WOULD SUGGEST AROUND 2 INCH VALUES IN TO OUR AREA IN THE
NEXT FEW HOURS. THESE VALUES WOULD BE AROUND THE +2 STANDARD
DEVIATION VALUES FOR THIS TIME OF YEAR. RUC MAY BE A LITTLE HIGH
WITH THESE NUMBERS THOUGH. GFS AND NAM BOTH ARE JUST ABOVE 1.9
INCHES.
HAVE NOT CHANGED POP FORECAST MUCH FOR TODAY...KEEPING A 40 TO 50
POP FOR EASTERN AREAS DURING THE DAY. UPPER LEVEL ENERGY PUSHES
OUT OF THE AREA LATER THIS AFTERNOON ENDING PRECIP CHANCES. HAVE
JUST A LINGERING 20 POP IN THE EAST AFTER 00Z THIS EVENING. MID
LEVEL WAA WILL THEN INCREASE A CAPPING INVERSION OVER THE AREA
TONIGHT INTO THURSDAY.
TEMPERATURES WARM A BIT TODAY IN THE WEST...BUT PRECIP IN THE EAST
COULD KEEP THE BRUSH COUNTRY AND COASTAL BEND AT OR BELOW
YESTERDAYS TEMPS. ADDITIONALLY...A THICK CLOUD COVER LOOKS TO
PERSIST OVER THE AREA WITH STRATUS MAYBE JUST A COUPLE THOUSAND
FEET UP ALL DAY. BY THURSDAY CLOUDS BEGIN TO CLEAR WEST TO EAST
AND SHOULD ALLOW FOR WARMER TEMPS. LAREDO COULD BE NEAR 100.
LONG TERM (THURSDAY NIGHT THROUGH TUESDAY)...STRONG CAP IS IN PLACE
ACROSS SOUTH TEXAS LATE THIS WEEK THROUGH EARLY NEXT WEEK. PWATS
DO INCREASE BACK UP THE RIO GRANDE OVER THE WEEKEND TO NEAR 1.5
INCHES. MODELS INDICATE THE TAIL END OF A WEAK SHORTWAVE MOVING OUT
OF MEXICO AND ACROSS SOUTH TEXAS LATE SATURDAY INTO SUNDAY.
CONVECTION MAY FIRE ALONG THE SIERRA MADRE LATE SATURDAY AFTERNOON
AND MOVE TOWARDS THE RIO GRANDE SATURDAY EVENING...BUT STRENGTH OF
CAP OVER THE REGION MAKES CONFIDENCE IN CONVECTION REACHING WESTERN
CWA LOW...AND THEREFORE NO WX CURRENTLY MENTIONED. OTHERWISE LONG
TERM WILL FEATURE WARM AND DRY CONDITIONS ACROSS SOUTH TEXAS WITH
PERIODS OF BREEZY CONDITIONS. 12Z ECMWF HAD BEEN INDICATE WEAK FRONT
APPROACHING NORTHERN CWA LATE TUESDAY (DAY 7) BUT HAS BACKED OFF TO
THE NORTH IN THE 00Z RUN.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 85 73 87 74 90 / 50 20 10 10 10
VICTORIA 83 72 85 74 88 / 50 20 10 10 10
LAREDO 93 73 100 73 99 / 20 10 10 10 10
ALICE 87 70 91 73 91 / 40 10 10 10 10
ROCKPORT 83 74 83 74 84 / 50 20 10 10 10
COTULLA 91 71 97 73 98 / 30 10 10 10 10
KINGSVILLE 87 72 89 74 91 / 40 10 10 10 10
NAVY CORPUS 80 74 84 73 84 / 50 20 10 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
PZ/83...AVIATION
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1212 PM CDT WED MAY 15 2013
.SHORT TERM.../TODAY /...
ISSUED AT 359 AM CDT WED MAY 15 2013
SURFACE HIGH PRESSURE WILL MOVE INTO THE STATE
TODAY AND WILL PROVIDE A MUCH QUIETER DAY ACROSS THE FORECAST
AREA. THERE IS A SMALL POTENTIAL FOR SOME VERY HIGH BASED
SHOWERS AND A STRAY THUNDERSTORM ACROSS NORTHERN IOWA THIS
MORNING...DUE TO SOME WEAK THETA-E ADVECTION AND FORCING BETWEEN
700-500MB. HRRR HAS THE ISOLATED SHOWERS THROUGH 18Z...BUT 00Z NMM
WRF DIMINISHING THE SHOWER ACTIVITY BEFORE ENTERING THE STATE.
LEANED TOWARD THE HRRR AS IT SEEMED TO HAVE A DECENT GRASP ON
CURRENT RADAR TRENDS.
WEAK BOUNDARY ACROSS SOUTHERN IOWA LOOKS TO BE A FOCAL POINT FOR
SOME ISOLATED THUNDERSTORMS THIS AFTERNOON. AGAIN...VERY HIGH BASED
AS VERY MINIMAL MOISTURE BELOW 700MB.
MAX TEMPS TODAY A LITTLE TRICK AS THINK GUIDANCE IS TOO LOW AGAIN
AND FELT CONFIDENT ENOUGH TO TWEAK TEMPS UP TODAY...ESPECIALLY
ACROSS THE SOUTH WHERE THE COOLER AIR DOES NOT REACH THIS AREA
UNTIL THE AFTERNOON. WENT ABOVE GUIDANCE ACROSS THE CENTRAL TO
SOUTHERN PORTIONS OF THE FORECAST AREA...WHICH WAS FAIRLY CLOSE TO
THE MAV MOS GUIDANCE. IN NORTHERN IOWA WENT CLOSER THE THE NAM/MET
MOS GUIDANCE FOR MAX TEMPS.
.LONG TERM.../TONIGHT THROUGH TUESDAY/...
ISSUED AT 359 AM CDT WED MAY 15 2013
RELATIVELY ACTIVE PERIOD THROUGH THE EXTENDED. HIGH PRESSURE WILL
GRADUALLY DEPART TONIGHT INTO THURSDAY AND AS IT DOES...A STALLED
FRONTAL BOUNDARY OVER NORTHERN MISSOURI WILL BEGIN TO LIFT BACK
NORTH INTO IOWA. AS THIS OCCURS...A PLUME OF MOISTURE LIFTING
THROUGH OKLAHOMA AND KANSAS WILL ARRIVE INTO SRN IA. THIS WILL
BRING BACK THE CHANCE FOR THUNDERSTORMS IN THAT REGION. A STRONG
PV ANOMALY OVER SRN NEVADA WILL APPROACH IA LATE THURSDAY AND
THURSDAY NIGHT. PREFER THE FARTHER NORTH NAM/ECMWF SOLUTION OVER
THE LESS ORGANIZED AND FARTHER SOUTH GFS. THIS WOULD PLACE THE
FOCUS FOR ADDITIONAL THUNDERSTORMS OVER NORTHWEST AND NORTH
CENTRAL IOWA. THIS POPS CONTINUE INTO FRIDAY MAINLY OVER THE
NORTH. EXPECT AT THIS POINT THAT POPS MAY BE OVERDONE FOR FRIDAY.
HAVE BEGUN TO TRIM BACK OVER THE CENTRAL AND SOUTH BUT IT MAY VERY
WELL BE MOSTLY DRY MOST LOCATIONS. THE SAME CAN BE SAID FOR FRIDAY
NIGHT WHERE POPS HAVE BEEN DROPPED FOR ALL BUT THE FAR NORTHEAST.
IOWA WILL BE IN THE WARM SECTOR ON SATURDAY AND WHILE LOW POPS
REMAIN...THE CONVECTIVE INHIBITION SHOULD HOLD STRONG MUCH OF THE
DAY. THE PRECIPITATION CHANCES THROUGH THE REMAINDER OF THE PERIOD
ARE MORE COMPLEX. THE INITIAL WAVE TO MOVE INTO THE INTER MOUNTAIN
WEST WILL BE FOLLOWED BY ANOTHER INTENSE PIECE OF ENERGY SATURDAY
NIGHT INTO SUNDAY. LONG RANGE GUIDANCE IS BEGINNING TO FAVOR THE
TWO TO MERGE AND FORM A CLOSED LOW TO THE WEST/NORTHWEST OF THE
AREA. THE FIRST WAVE WILL NUDGE THE UPPER LEVEL RIDGE ENOUGH EAST
SATURDAY NIGHT TO BRING A RETURN FOR PRECIPITATION
CHANCES...MAINLY OVER THE NORTH HOWEVER THE EVOLUTION TO A CLOSE
LOW WILL SLOW THE BOUNDARY ARRIVAL TO LATER SUNDAY INTO MONDAY.
INCREASING SOUTHWEST FLOW OVER THE STATE WILL KEEP THE PERIOD
ACTIVE AND EVENTUALLY SHOULD BRING A SEVERE WEATHER THREAT TO THE
STATE. TEMPERATURES THROUGH THE PERIOD WILL GENERALLY BE ABOVE
SEASONAL VALUES. COOLER ACROSS THE SOUTH ON THURSDAY DUE TO
ENHANCED CLOUD COVER THEN WARMER AGAIN FRIDAY INTO SATURDAY.
&&
.AVIATION...15/18Z
ISSUED AT 1209 PM CDT WED MAY 15 2013
CEILINGS WILL REMAIN VFR FOR PERIOD AT SITES WITH HIGH PRESSURE
BUILDING IN. WINDS WILL BE GUSTY IN THE AFTERNOON WITH
MIXING...BUT WILL REMAIN BELOW 20KTS. BOUNDARY NEAR SOUTHERN IOWA
WILL BE FOCUS FOR ISOLATED RA/TSRA DEVELOPMENT IN THE AFTERNOON.
MAY SEE SOME TSRA AT SOUTHERN SITES...KDMS/KOTM...BUT HAVE NOT
INCLUDED MENTION ATTM WITH SCATTERED NATURE OF RA. WINDS WILL
DECREASE AFTER 00Z...BECOMING MORE EASTERLY.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...PODRAZIK
LONG TERM...DONAVON
AVIATION...AWB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
440 PM EDT WED MAY 15 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 409 PM EDT WED MAY 15 2013
WV IMAGERY AND RUC ANALYSIS INDICATED WNW MID/UPPER LEVEL FLOW
THROUGH THE NRN GREAT LAKES ON THE SRN FLANK OF A TROUGH OVER NRN
ONTARIO TO THE SRN END OF JAMES BAY. A WEAK SHORTWAVE TROUGH
OVER THE SE CORNER OF MANITOBA SUPPORTED AN AREA OF MID CLOUDS AND
SOME SCT/ISOLD -SHRA INTO NW MN. AT THE SFC...A TIGHT PRES GRADIENT
PERSISTED BTWN A 995 MB LOW BTWN JAMES BAY AND LAKE SUPERIOR AND A
RIDGE FROM THE NRN PLAINS INTO SRN MN. WNW WINDS HAVE GUSTED AT OR
ABOVE 30 MPH OVER MUCH OF UPPER MI AND TO NEAR 45 MPH WHERE TERRAIN
HAS BOOSTED THE WINDS AT CMX. SUNSHINE WITH TEMPS INTO THE LOWER TO
MID 70S AND DEEP MIXING TO AROUND 750 MB HAS LOWERED DEWPOINTS TO
AROUND 30F WITH RH VALUES TO AROUND 20 PCT. THE COMBINATION OF THE
DRY AIR WINDS HAS RESULTED IN CRITICAL FIRE WEATHER CONDITIONS.
TONIGHT...AS THE PRES GRADIENT WEAKENS AND DAYTIME HEATING
SUBSIDES...WINDS WILL DIMINISH QUICKLY THIS EVENING AND BECOME LIGHT
OVERNIGHT. HIGHER RES SHORT RANGE MODELS SUGGEST THAT THE BEST
CHANCES OF PCPN ASSOCIATED WITH THE MANITOBA SHORTWAVE OVER THE SW
HALF OF UPPER MI. EVEN THERE...WITH DRY LOW LEVELS AND WEAK FORCING
WITH THE SHRTWV MAINLY JUST SPRINKLES AT MOST WOULD BE EXPECTED.
SO...ONLY A SMALL AREA OF SLIGHT CHANCE POPS WERE INCLUDED.
THURSDAY...EXPECT COOLER CONDITIONS OVER THE NORTH HALF OF UPPER MI
WITH NRLY WINDS BEHIND A COLD FRONT MOVING THROUGH THE AREA LATE
TONIGHT. WITH 850 MB TEMPS RANGING FROM AROUND 4C NORTH TO TO 9C
SOUTH...TEMPS SHOULD RANGE FROM THE LOWER 50S NEAR LAKE SUPERIOR TO
THE LOWER 70S INLAND SOUTHWEST. SUNSHINE AND FAVORABLE MIXING WILL
AGAIN DROP DEWPOINTS INTO THE LOWER 30S WITH RH VALUES TO AROUND 25
PERCENT SOUTH. HOWEVER...WITH WINDS ONLY TO AROUND 10 MPH...THE
WILDFIRE RISK WILL BE LOWER THAN TODAY.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 440 PM EDT WED MAY 15 2013
TEMPS WILL HOLD STEADY IN THE 60S ON FRIDAY AND SATURDAY...WITH A
WARM UP FOR SUNDAY AS SSE WINDS INCREASE AHEAD OF LOW PRESSURE
NEARING FROM THE CENTRAL PLAINS. AT THIS POINT THE STRONGER WINDS
LOOK TO BE ASSOCIATED WITH INCREASED DEW POINTS...LIMITING
SIGNIFICANT FIRE CONCERNS.
THERE IS A LOT OF UNCERTAINTY WITH THE MID TO LONGER RANGE OF THIS
FORECAST...WITH THE TRACK AND TIMING OF THE SLOW MOVING LOW PRESSURE
SYSTEM. WITH THAT SAID...THERE IS A SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS IN THE FORECAST FROM SATURDAY ON /MAINLY WEST/.
THUNDERSTORM CHANCES ARE NOT THAT IMPRESSIVE. IT LOOKS LIKE THE BEST
CHANCE FOR SHOWERS AND THUNDERSTORMS ACROSS THE ENTIRE CWA WILL HOLD
OFF UNTIL MONDAY...WITH THE SFC LOW IS SET UP OVER THE EASTERN
DAKOTAS AND WESTERN MN. THE SYSTEM CONTINUES TO SLOW DOWN...AS IT
WAS ORIGINALLY EXPECTED TO CROSS UPPER MI ON SUNDAY...AT LEAST OF A
COUPLE OF DAYS AGO. NOW IT LOOKS TO HOLD OFF UNTIL TUESDAY AT THE
EARLIEST /12Z ECMWF SOLUTION/. THE GFS IS EVEN SLOWER...AND HAS THE
500MB LOW OVER ND TUESDAY AFTERNOON RETROGRADING AND CONSOLIDATING
WITH THE DEEP LOW PUSHING INTO THE PACIFIC NORTHWEST. WILL OPT FOR
FOR A SOLUTION CLOSER TO THE ECMWF AT THIS POINT...WITH LOWER
CONFIDENCE IN THE FORECAST BEYOND SUNDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 149 PM EDT WED MAY 15 2013
VFR CONDITIONS ARE EXPECTED TO PREVAIL AT ALL THREE TAF SITES
THROUGH THE FORECAST PERIOD. EXPECT WNW WINDS TO GUST OVER 20 KTS AT
ALL THE SITES TODAY...STRONGEST AT KCMX AND KSAW. ONLY SKY COVER
WILL BE SCT-BKN MID CLOUDS...ESPECIALLY THIS AFTERNOON AND EVENING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 409 PM EDT WED MAY 15 2013
EXPECT WINDS WITH GUSTS 25 KNOTS TO DIMINISH TONIGHT AS HIGH PRES
BUILDS INTO THE REGION. HIGH PRESSURE WILL EXPAND ACROSS GREAT LAKES
INTO THE WEEKEND WITH EAST-SOUTHEAST WINDS AT OR BLO 25 KTS. WINDS
BECOME SOUTHERLY LATE THIS WEEKEND AHEAD OF LOW PRESSURE TROUGH
PUSHING IN FROM NORTHERN PLAINS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
RED FLAG WARNING UNTIL 9 PM EDT /8 PM CDT/ THIS EVENING FOR
MIZ002-004>006-009>014-084-085.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
411 PM EDT WED MAY 15 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 409 PM EDT WED MAY 15 2013
WV IMAGERY AND RUC ANALYSIS INDICATED WNW MID/UPPER LEVEL FLOW
THROUGH THE NRN GREAT LAKES ON THE SRN FLANK OF A TROUGH OVER NRN
ONTARIO TO THE SRN END OF JAMES BAY. A WEAK SHORTWAVE TROUGH
OVER THE SE CORNER OF MANITOBA SUPPORTED AN AREA OF MID CLOUDS AND
SOME SCT/ISOLD -SHRA INTO NW MN. AT THE SFC...A TIGHT PRES GRADIENT
PERSISTED BTWN A 995 MB LOW BTWN JAMES BAY AND LAKE SUPERIOR AND A
RIDGE FROM THE NRN PLAINS INTO SRN MN. WNW WINDS HAVE GUSTED AT OR
ABOVE 30 MPH OVER MUCH OF UPPER MI AND TO NEAR 45 MPH WHERE TERRAIN
HAS BOOSTED THE WINDS AT CMX. SUNSHINE WITH TEMPS INTO THE LOWER TO
MID 70S AND DEEP MIXING TO AROUND 750 MB HAS LOWERED DEWPOINTS TO
AROUND 30F WITH RH VALUES TO AROUND 20 PCT. THE COMBINATION OF THE
DRY AIR WINDS HAS RESULTED IN CRITICAL FIRE WEATHER CONDITIONS.
TONIGHT...AS THE PRES GRADIENT WEAKENS AND DAYTIME HEATING
SUBSIDES...WINDS WILL DIMINISH QUICKLY THIS EVENING AND BECOME LIGHT
OVERNIGHT. HIGHER RES SHORT RANGE MODELS SUGGEST THAT THE BEST
CHANCES OF PCPN ASSOCIATED WITH THE MANITOBA SHORTWAVE OVER THE SW
HALF OF UPPER MI. EVEN THERE...WITH DRY LOW LEVELS AND WEAK FORCING
WITH THE SHRTWV MAINLY JUST SPRINKLES AT MOST WOULD BE EXPECTED.
SO...ONLY A SMALL AREA OF SLIGHT CHANCE POPS WERE INCLUDED.
THURSDAY...EXPECT COOLER CONDITIONS OVER THE NORTH HALF OF UPPER MI
WITH NRLY WINDS BEHIND A COLD FRONT MOVING THROUGH THE AREA LATE
TONIGHT. WITH 850 MB TEMPS RANGING FROM AROUND 4C NORTH TO TO 9C
SOUTH...TEMPS SHOULD RANGE FROM THE LOWER 50S NEAR LAKE SUPERIOR TO
THE LOWER 70S INLAND SOUTHWEST. SUNSHINE AND FAVORABLE MIXING WILL
AGAIN DROP DEWPOINTS INTO THE LOWER 30S WITH RH VALUES TO AROUND 25
PERCENT SOUTH. HOWEVER...WITH WINDS ONLY TO AROUND 10 MPH...THE
WILDFIRE RISK WILL BE LOWER THAN TODAY.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 429 AM EDT WED MAY 15 2013
TO START THE LONG TERM...AT 12Z THU...SFC AND UPPER RIDGE WILL BE
MOVING INTO THE CWA FROM THE NW...STICKING AROUND THROUGH FRI. THIS
WILL CREATE MOSTLY SUNNY SKIES FOR THE MOST PART THU THROUGH FRIDAY.
EXPECT HIGHS IN THE 60S AND 70S FOR THE LAST 2 DAYS OF THE WORK
WEEK.
AN UPPER TROUGH MOVING INTO THE WRN CONUS AND DEEPENING SFC LOW
PRESSURE OVER THE PLAINS STATES WILL DRAW A FRONTAL ZONE NORTHWARD
TO NEAR THE CWA FOR SAT AND SUN. THIS WILL BRING PRECIP CHANCES TO
THE CWA...BUT MOST MODELS SHOW PRECIP EITHER N OR S OF THE CWA OR A
COMBINATION THEREOF. DECREASED POPS FOR THIS TIME PERIOD AS MODELS
HAVE POOR AGREEMENT AND RUN TO RUN CONTINUITY WITH THE EVER VOLATILE
CONVECTION. EXPECT TEMPS TO BE SIMILAR TO THU AND FRI IN THE 60S AND
70S.
MON INTO THE MIDDLE OF NEXT WEEK...MODELS SHOW THE SYSTEM CLOSING
OFF OVER MN AND EVENTUALLY MOVING ACROSS OR NEAR THE CWA...BUT
UNCERTAINTY REMAINS HIGH GIVEN POOR MODEL AGREEMENT AND POOR RUN TO
RUN CONTINUITY WITH THE SYSTEM AND ASSOCIATED PRECIP. CONVECTION IS
ESPECIALLY HARD TO PINPOINT AT THIS TIME FRAME...FURTHER DECREASING
CONFIDENCE. TEMPS SHOULD COOL DOWN A BIT MOVING INTO MID WEEK IF THE
UPPER LOW DOES INDEED MOVE TOWARD OR OVER THE CWA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 149 PM EDT WED MAY 15 2013
VFR CONDITIONS ARE EXPECTED TO PREVAIL AT ALL THREE TAF SITES
THROUGH THE FORECAST PERIOD. EXPECT WNW WINDS TO GUST OVER 20 KTS AT
ALL THE SITES TODAY...STRONGEST AT KCMX AND KSAW. ONLY SKY COVER
WILL BE SCT-BKN MID CLOUDS...ESPECIALLY THIS AFTERNOON AND EVENING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 409 PM EDT WED MAY 15 2013
EXPECT WINDS WITH GUSTS 25 KNOTS TO DIMINISH TONIGHT AS HIGH PRES
BUILDS INTO THE REGION. HIGH PRESSURE WILL EXPAND ACROSS GREAT LAKES
INTO THE WEEKEND WITH EAST-SOUTHEAST WINDS AT OR BLO 25 KTS. WINDS
BECOME SOUTHERLY LATE THIS WEEKEND AHEAD OF LOW PRESSURE TROUGH
PUSHING IN FROM NORTHERN PLAINS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
RED FLAG WARNING UNTIL 9 PM EDT /8 PM CDT/ THIS EVENING FOR
MIZ002-004>006-009>014-084-085.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS HASTINGS NE
558 PM CDT WED MAY 15 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 348 PM CDT WED MAY 15 2013
FORECAST COULD BE PRETTY COMPLICATED CONCERNING CHANCES OF
PRECIPITATION FOR THE SHORT TERM.
FOR STARTERS...A NEARLY STATIONARY BOUNDARY IN OUR FAR SOUTHERN CWA
COULD BE THE FOCUS OF SOME AFTERNOON AND EVENING THUNDERSTORM
ACTIVITY. SHEAR IS EXTREMELY WEAK AND INSTABILITY IS MARGINAL AT
BEST. WE STILL HAVE INVERTED V SOUNDINGS...BUT NOT MIXING NEARLY AS
HIGH AS YESTERDAY...AND AIR NOT NEARLY AS DRY. OUR MAIN CONCERN
WOULD BE TO GET AN ISOLATED STRONG TO SEVERE WIND GUST...BUT THIS
WOULD BE A LONGSHOT. WENT CLOSER WITH RAP FOR DEWPOINTS AND WIND
WITHIN THE FIRST 6 TO 12 HOURS AS THE SOLUTIONS OF THIS MODEL HAVE
BEEN SUPERIOR TO OTHERS. I HAD TO INCREASE THE TOP END OF WIND
SPEEDS A BIT AS WE ARE MIXING A BIT BETTER THAN WHAT IS
FORECAST...BUT AS THE FRONT EDGES NORTH...WIND SPEEDS SHOULD
DECREASE ACROSS MUCH OF THE CWA. WENT TOWARD CONSRAW FOR DEWPOINTS
AS WE GET CLOSER TO THE OVERNIGHT HOURS INTO THURSDAY. THERE IS A
BIT OF A SIGNAL FOR SOME FOG TONIGHT FROM THE SREF SO WILL
CONTINUE WITH MENTIONING OF PATCHY FOG...ESPECIALLY AS THE FRONT
MOVES NORTH.
THE FORECAST GETS A LITTLE MUDDLED TONIGHT FOR PRECIPITATION
CHANCES. MODELS ARE GENERALLY LIFTING THE BOUNDARY TO THE NORTH AS A
WARM FRONT. THERE WILL NOT BE MUCH OF A LOW-LEVEL JET TO SUSTAIN ANY
CONVECTION THAT MIGHT FIRE UP THIS AFTERNOON AND EVENING. WITH
DECREASING WITH SUNSET...MOST CONVECTION SHOULD DIE OUT.
OVERNIGHT...HOWEVER...SOME MODELS ARE INDICATING THE POSSIBILITY OF
MORE CONVECTION MAINLY IN THE NORTHERN CWA. THE NMM INDICATES A
POSSIBLE SMALL-SCALE MCS DEVELOP OVER THE CWA OF LBF AND FOLLOW THE
BOUNDARY TO THE EAST ACROSS THE NORTHERN CWA...WHICH MAY POSSIBLY
LAST INTO THE EARLY MORNING HOURS.
THEN ANOTHER LULL IS LIKELY BY LATE MORNING THURSDAY INTO EARLY
AFTERNOON AS THE BOUNDARY TO THE NORTH EITHER CONTINUES TO LIFT
NORTH OR WASHES OUT...DEPENDING ON WHICH SOLUTION IS REALIZED.
EITHER WAY...A LULL IS LIKELY. A MID-LEVEL PERTURBATION IS STILL
FORECAST TO MOVE EAST ACROSS THE AREA BY THURSDAY AFTERNOON...BUT
AMPLITUDE SHOULD REMAIN QUITE LOW. AS A THETA E RIDGE SHIFTS
EAST...ALONG WITH THE WEAK PERTURBATION...WE SHOULD HAVE A GOOD SHOT
OF SOME SHOWERS AND THUNDERSHOWERS...ESPECIALLY WEST/INTO CENTRAL
PARTS OF THE CWA. MUCAPES WILL BE HIGH ENOUGH TO SUSTAIN
THUNDERSTORMS...BUT SHEAR WILL BE WEAK ONCE AGAIN...SO SEVERE
WEATHER WOULD NOT BE OUT OF THE QUESTION...BUT CERTAINLY NO OUTBREAK
IS ANTICIPATED.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 348 PM CDT WED MAY 15 2013
FOCUS OF THE LONG TERM PERIOD WILL CENTER AROUND CHANCES FOR
THUNDERSTORMS...SOME OF WHICH MIGHT BE POSSIBLY SEVERE AT
TIMES...MAINLY SATURDAY AFTERNOON THROUGH SUNDAY EVENING.
THE CUTOFF LOW ACROSS THE DESERT SOUTHWEST WILL FINALLY BEGIN TO
INGEST BACK INTO THE MEAN FLOW THROUGHOUT THE SHORT TERM...FINALLY
SHIFTING OFF TO THE SOUTHEAST ACROSS MISSOURI AND ARKANSAS BY
THURSDAY NIGHT. THROUGH THE OVERNIGHT PERIODS...A WEAK UPPER LEVEL
DISTURBANCE WILL BEGIN TO SHIFT ACROSS THE PLAINS...ON THE BACKSIDE
OF THE UPPER LEVEL LOW. MODELS DISAGREE ON THE DEPTH OF THE
WAVE...WITH THE ECMWF...UKMET AND NAM SOLUTIONS A BIT MORE SHALLOW
THAN THE DEEPER PROGRESSIVE GFS. AT THE SURFACE...MODELS INDICATE A
A DEVELOPING TROUGH ALONG THE FRONT RANGE OF THE ROCKIES...WITH SOME
SORT OF FRONT...WASHED OUT BOUNDARY SHIFTING NORTH OF THE OUTLOOK
AREA. COMBINED WITH THE WAVE AND WARM AIR ADVECTION...MODELS
CONTINUE TO HINT AT AT LEAST A CHANCE FOR PRECIPITATION...WITH THE
GFS HEDGING FURTHER SOUTH INTO KANSAS. AT THIS POINT...REALLY NOT
BUYING INTO THE SOUTHERN SOLUTION AND TRENDING MORE TOWARDS A
NEBRASKA RAIN EVENT.
AFTER THE PASSAGE OF THE UPPER LEVEL WAVE...SUBSIDENCE TAKES
HOLD...AND CURRENT THINKING IS THAT MUCH OF FRIDAY DURING THE DAY
WILL BE DRY. HOWEVER...BY FRIDAY AFTERNOON AND EVENING...ANOTHER
UPPER LEVEL TROUGH WILL BEGIN TO SHIFT INTO THE AREA. WITH THE
EASTWARD PROGRESSION OF THE TROUGH...HEIGHT FALLS...AND A SURFACE
LEESIDE TROUGH...ITS POSSIBLE WESTERN PORTIONS OF NEBRASKA COULD SEE
SOME CONVECTION FRIDAY AFTERNOON. A FAIRLY DECENT LLJ IS EXPECTED TO
DEVELOP ACROSS WESTERN AREAS AND SHIFT EASTWARD OVERNIGHT. THIS
COMBINED WITH A DECENT THETA E RIDGE OVER THE OUTLOOK AREA...WENT
AHEAD AND CONTINUED AT LEAST SLIGHT POPS OVERNIGHT. SHOULD STORMS
DEVELOP...THERE IS PLENTY OF INSTABILITY TO WORK WITH...ABOUT
2000-3000 J/KG. HOWEVER...A STRONG CAP EXISTS WITH 700 MB
TEMPERATURES NEAR 10 TO 11 DEGREES...AND BULK SHEAR IS LIMITED
AROUND 20 TO 30 KTS.
SATURDAY LOOKS TO BE THE MAIN FOCUS OF THE MID TERM PERIOD...AS THE
UPPER LEVEL LOW SHIFTS EASTWARD. BY SATURDAY AFTERNOON...THE SURFACE
TROUGH BECOMES ELONGATED ALONG THE FRONT RANGE. BOTH THE GFS AND
ECMWF SOLUTIONS HAVE BEGUN TO TREND A BIT SLOWER IN PREVIOUS
RUNS...BRINGING IN CHANCES FOR PRECIPITATION ACROSS THE
WEST...MAINLY DURING LATE AFTERNOON AND EVENING. INSTABILITY IS
QUITE HIGH DURING THE SATURDAY AFTERNOON PERIOD THROUGH
OVERNIGHT...WITH 4000 TO 5000 J/KG POSSIBLE. AGAIN...AS HAS BEEN THE
CASE MOST OF THIS WEEK...700 MB TEMPERATURES ARE ON THE ORDER OF 10
TO 12 AND EVEN 13 DEGREES AT TIMES. 0 TO 6 KM BULK SHEAR IS ALSO AT
ITS HIGHEST SATURDAY EVENING...CLIMBING TO NEAR 30 TO 40 KTS...WITH
50 KTS EXPECTED FURTHER WEST.
BY SUNDAY AFTERNOON...THE SURFACE TROUGH AND FRONTAL BOUNDARY WILL
FINALLY MIGRATE EASTWARD ACROSS THE CWA. THIS WILL GIVE US YET
ANOTHER CHANCE FOR PRECIPITATION...POSSIBLY SEVERE AS THE CWA
REMAINS SITUATED JUST ON THE EASTERN FRINGE OF THE UPPER LEVEL
TROUGH. THE ECMWF SOLUTIONS TENDS TO BE A BIT MORE PROGRESSIVE THAN
THE GFS SOLUTION WITH A CLOSED LOW ACROSS NORTHERN NEBRASKA BY 0Z
MONDAY...WHILE THE GFS REMAINS CLOSED OVER THE PANHANDLE. SEVERE IS
BEGINNING TO LOOK POSSIBLE ALSO ON SUNDAY. INSTABILITY DOES NOT LOOK
QUITE AS STRONG AS SATURDAY BUT STILL IS NEAR 2000 J/KG OF MOST
UNSTABLE CAPE. HOWEVER...THE CAP IS ALSO NOT QUITE AS STRONG WITH
700 MB TEMPERATURES ON THE ORDER OF 6 TO 7 DEGREES CELSIUS.
THEREFORE...SEVERE STORMS DO NOT LOOK OUT OF THE QUESTION FOR SUNDAY
AFTERNOON.
THROUGH THE REST OF THE LONG TERM...THE UPPER LEVEL LOW SPINS ACROSS
THE PLAINS GENERATING CHANCES FOR PRECIPITATION THROUGH MONDAY.
HOWEVER...AN UPPER LEVEL RIDGE LOOKS TO SLOWLY BEGIN TO BUILD ACROSS
THE DESERT SOUTHWEST TOWARDS THE BEGINNING OF NEXT WEEK. AS
SUCH...THE UPPER LEVEL LOW EJECTS NORTHWARD...WITH PRECIPITATION
QUICKLY EXITING THE REGION. DECIDED TO PULL OUT ANY SLIGHT MENTION
OF PRECIPITATION ALONG THE FRINGES OF THE CWA AS THE CWA SEEMS TO
BECOME DRY SLOTTED BY MONDAY NIGHT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 558 PM CDT WED MAY 15 2013
VFR CONDITIONS EXPECTED THROUGH THE NEXT 24 HOURS...WITH
CONVECTIVE ACTIVITY ALSO POSSIBLE.
INCREASING HIGH LEVEL CLOUDS...WITH BASES NEAR 20000FT AGL...WILL
BE OBSERVED DURING THE TAF PERIOD. A SCATTERED CUMULUS
FIELD...WITH BASES NEAR 6000FT AGL...WILL ALSO LIKELY BE OBSERVED
IN THE AREA THURSDAY AFTERNOON. ISOLATED TO SCATTERED CONVECTION
WILL BE POSSIBLE NEAR THE TERMINAL TONIGHT...PRIMARILY AFTER
06Z...BUT THE PROBABILITY OF MEASURABLE PRECIPITATION BEING
REALIZED AT KGRI IS TOO LOW FOR INSERTION INTO THE TAF AT THIS
TIME. A BETTER CHANCE FOR SCATTERED CONVECTION IS FORECAST AT AND
NEAR KGRI THURSDAY AFTERNOON...WHICH MAY IN TURN PROVIDE
MEASURABLE PRECIPITATION TO THE TERMINAL. THAT BEING
SAID...CONFIDENCE IS ONLY HIGH ENOUGH TO PROVIDE VCTS STARTING 21Z
THURSDAY...FOR THE TIME BEING. THERE IS AN OUTSIDE CHANCE OF
PATCHY FOG DEVELOPMENT AROUND SUNRISE THURSDAY...BUT THE
PROBABILITY OF VISIBILITY RESTRICTION BEING REALIZED AT THE
TERMINAL IS TOO LOW FOR INSERTION INTO THE TAF AT THIS TIME. THE
SURFACE WIND WILL REMAIN FROM THE EAST...SUSTAINED AT AROUND
12KTS...TO START THE TAF PERIOD...BECOMING LIGHT AND VARIABLE
TONIGHT AND THEN BECOMING ESTABLISHED FROM THE SOUTHEAST AT AROUND
12KTS DURING THE DAY THURSDAY.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...HEINLEIN
LONG TERM...SALTZMAN
AVIATION...BRYANT
AREA FORECAST DISCUSSION
NWS HASTINGS NE
353 PM CDT WED MAY 15 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 348 PM CDT WED MAY 15 2013
FORECAST COULD BE PRETTY COMPLICATED CONCERNING CHANCES OF
PRECIPITATION FOR THE SHORT TERM.
FOR STARTERS...A NEARLY STATIONARY BOUNDARY IN OUR FAR SOUTHERN CWA
COULD BE THE FOCUS OF SOME AFTERNOON AND EVENING THUNDERSTORM
ACTIVITY. SHEAR IS EXTREMELY WEAK AND INSTABILITY IS MARGINAL AT
BEST. WE STILL HAVE INVERTED V SOUNDINGS...BUT NOT MIXING NEARLY AS
HIGH AS YESTERDAY...AND AIR NOT NEARLY AS DRY. OUR MAIN CONCERN
WOULD BE TO GET AN ISOLATED STRONG TO SEVERE WIND GUST...BUT THIS
WOULD BE A LONGSHOT. WENT CLOSER WITH RAP FOR DEWPOINTS AND WIND
WITHIN THE FIRST 6 TO 12 HOURS AS THE SOLUTIONS OF THIS MODEL HAVE
BEEN SUPERIOR TO OTHERS. I HAD TO INCREASE THE TOP END OF WIND
SPEEDS A BIT AS WE ARE MIXING A BIT BETTER THAN WHAT IS
FORECAST...BUT AS THE FRONT EDGES NORTH...WIND SPEEDS SHOULD
DECREASE ACROSS MUCH OF THE CWA. WENT TOWARD CONSRAW FOR DEWPOINTS
AS WE GET CLOSER TO THE OVERNIGHT HOURS INTO THURSDAY. THERE IS A
BIT OF A SIGNAL FOR SOME FOG TONIGHT FROM THE SREF SO WILL
CONTINUE WITH MENTIONING OF PATCHY FOG...ESPECIALLY AS THE FRONT
MOVES NORTH.
THE FORECAST GETS A LITTLE MUDDLED TONIGHT FOR PRECIPITATION
CHANCES. MODELS ARE GENERALLY LIFTING THE BOUNDARY TO THE NORTH AS A
WARM FRONT. THERE WILL NOT BE MUCH OF A LOW-LEVEL JET TO SUSTAIN ANY
CONVECTION THAT MIGHT FIRE UP THIS AFTERNOON AND EVENING. WITH
DECREASING WITH SUNSET...MOST CONVECTION SHOULD DIE OUT.
OVERNIGHT...HOWEVER...SOME MODELS ARE INDICATING THE POSSIBILITY OF
MORE CONVECTION MAINLY IN THE NORTHERN CWA. THE NMM INDICATES A
POSSIBLE SMALL-SCALE MCS DEVELOP OVER THE CWA OF LBF AND FOLLOW THE
BOUNDARY TO THE EAST ACROSS THE NORTHERN CWA...WHICH MAY POSSIBLY
LAST INTO THE EARLY MORNING HOURS.
THEN ANOTHER LULL IS LIKELY BY LATE MORNING THURSDAY INTO EARLY
AFTERNOON AS THE BOUNDARY TO THE NORTH EITHER CONTINUES TO LIFT
NORTH OR WASHES OUT...DEPENDING ON WHICH SOLUTION IS REALIZED.
EITHER WAY...A LULL IS LIKELY. A MID-LEVEL PERTURBATION IS STILL
FORECAST TO MOVE EAST ACROSS THE AREA BY THURSDAY AFTERNOON...BUT
AMPLITUDE SHOULD REMAIN QUITE LOW. AS A THETA E RIDGE SHIFTS
EAST...ALONG WITH THE WEAK PERTURBATION...WE SHOULD HAVE A GOOD SHOT
OF SOME SHOWERS AND THUNDERSHOWERS...ESPECIALLY WEST/INTO CENTRAL
PARTS OF THE CWA. MUCAPES WILL BE HIGH ENOUGH TO SUSTAIN
THUNDERSTORMS...BUT SHEAR WILL BE WEAK ONCE AGAIN...SO SEVERE
WEATHER WOULD NOT BE OUT OF THE QUESTION...BUT CERTAINLY NO OUTBREAK
IS ANTICIPATED.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 348 PM CDT WED MAY 15 2013
FOCUS OF THE LONG TERM PERIOD WILL CENTER AROUND CHANCES FOR
THUNDERSTORMS...SOME OF WHICH MIGHT BE POSSIBLY SEVERE AT
TIMES...MAINLY SATURDAY AFTERNOON THROUGH SUNDAY EVENING.
THE CUTOFF LOW ACROSS THE DESERT SOUTHWEST WILL FINALLY BEGIN TO
INGEST BACK INTO THE MEAN FLOW THROUGHOUT THE SHORT TERM...FINALLY
SHIFTING OFF TO THE SOUTHEAST ACROSS MISSOURI AND ARKANSAS BY
THURSDAY NIGHT. THROUGH THE OVERNIGHT PERIODS...A WEAK UPPER LEVEL
DISTURBANCE WILL BEGIN TO SHIFT ACROSS THE PLAINS...ON THE BACKSIDE
OF THE UPPER LEVEL LOW. MODELS DISAGREE ON THE DEPTH OF THE
WAVE...WITH THE ECMWF...UKMET AND NAM SOLUTIONS A BIT MORE SHALLOW
THAN THE DEEPER PROGRESSIVE GFS. AT THE SURFACE...MODELS INDICATE A
A DEVELOPING TROUGH ALONG THE FRONT RANGE OF THE ROCKIES...WITH SOME
SORT OF FRONT...WASHED OUT BOUNDARY SHIFTING NORTH OF THE OUTLOOK
AREA. COMBINED WITH THE WAVE AND WARM AIR ADVECTION...MODELS
CONTINUE TO HINT AT AT LEAST A CHANCE FOR PRECIPITATION...WITH THE
GFS HEDGING FURTHER SOUTH INTO KANSAS. AT THIS POINT...REALLY NOT
BUYING INTO THE SOUTHERN SOLUTION AND TRENDING MORE TOWARDS A
NEBRASKA RAIN EVENT.
AFTER THE PASSAGE OF THE UPPER LEVEL WAVE...SUBSIDENCE TAKES
HOLD...AND CURRENT THINKING IS THAT MUCH OF FRIDAY DURING THE DAY
WILL BE DRY. HOWEVER...BY FRIDAY AFTERNOON AND EVENING...ANOTHER
UPPER LEVEL TROUGH WILL BEGIN TO SHIFT INTO THE AREA. WITH THE
EASTWARD PROGRESSION OF THE TROUGH...HEIGHT FALLS...AND A SURFACE
LEESIDE TROUGH...ITS POSSIBLE WESTERN PORTIONS OF NEBRASKA COULD SEE
SOME CONVECTION FRIDAY AFTERNOON. A FAIRLY DECENT LLJ IS EXPECTED TO
DEVELOP ACROSS WESTERN AREAS AND SHIFT EASTWARD OVERNIGHT. THIS
COMBINED WITH A DECENT THETA E RIDGE OVER THE OUTLOOK AREA...WENT
AHEAD AND CONTINUED AT LEAST SLIGHT POPS OVERNIGHT. SHOULD STORMS
DEVELOP...THERE IS PLENTY OF INSTABILITY TO WORK WITH...ABOUT
2000-3000 J/KG. HOWEVER...A STRONG CAP EXISTS WITH 700 MB
TEMPERATURES NEAR 10 TO 11 DEGREES...AND BULK SHEAR IS LIMITED
AROUND 20 TO 30 KTS.
SATURDAY LOOKS TO BE THE MAIN FOCUS OF THE MID TERM PERIOD...AS THE
UPPER LEVEL LOW SHIFTS EASTWARD. BY SATURDAY AFTERNOON...THE SURFACE
TROUGH BECOMES ELONGATED ALONG THE FRONT RANGE. BOTH THE GFS AND
ECMWF SOLUTIONS HAVE BEGUN TO TREND A BIT SLOWER IN PREVIOUS
RUNS...BRINGING IN CHANCES FOR PRECIPITATION ACROSS THE
WEST...MAINLY DURING LATE AFTERNOON AND EVENING. INSTABILITY IS
QUITE HIGH DURING THE SATURDAY AFTERNOON PERIOD THROUGH
OVERNIGHT...WITH 4000 TO 5000 J/KG POSSIBLE. AGAIN...AS HAS BEEN THE
CASE MOST OF THIS WEEK...700 MB TEMPERATURES ARE ON THE ORDER OF 10
TO 12 AND EVEN 13 DEGREES AT TIMES. 0 TO 6 KM BULK SHEAR IS ALSO AT
ITS HIGHEST SATURDAY EVENING...CLIMBING TO NEAR 30 TO 40 KTS...WITH
50 KTS EXPECTED FURTHER WEST.
BY SUNDAY AFTERNOON...THE SURFACE TROUGH AND FRONTAL BOUNDARY WILL
FINALLY MIGRATE EASTWARD ACROSS THE CWA. THIS WILL GIVE US YET
ANOTHER CHANCE FOR PRECIPITATION...POSSIBLY SEVERE AS THE CWA
REMAINS SITUATED JUST ON THE EASTERN FRINGE OF THE UPPER LEVEL
TROUGH. THE ECMWF SOLUTIONS TENDS TO BE A BIT MORE PROGRESSIVE THAN
THE GFS SOLUTION WITH A CLOSED LOW ACROSS NORTHERN NEBRASKA BY 0Z
MONDAY...WHILE THE GFS REMAINS CLOSED OVER THE PANHANDLE. SEVERE IS
BEGINNING TO LOOK POSSIBLE ALSO ON SUNDAY. INSTABILITY DOES NOT LOOK
QUITE AS STRONG AS SATURDAY BUT STILL IS NEAR 2000 J/KG OF MOST
UNSTABLE CAPE. HOWEVER...THE CAP IS ALSO NOT QUITE AS STRONG WITH
700 MB TEMPERATURES ON THE ORDER OF 6 TO 7 DEGREES CELSIUS.
THEREFORE...SEVERE STORMS DO NOT LOOK OUT OF THE QUESTION FOR SUNDAY
AFTERNOON.
THROUGH THE REST OF THE LONG TERM...THE UPPER LEVEL LOW SPINS ACROSS
THE PLAINS GENERATING CHANCES FOR PRECIPITATION THROUGH MONDAY.
HOWEVER...AN UPPER LEVEL RIDGE LOOKS TO SLOWLY BEGIN TO BUILD ACROSS
THE DESERT SOUTHWEST TOWARDS THE BEGINNING OF NEXT WEEK. AS
SUCH...THE UPPER LEVEL LOW EJECTS NORTHWARD...WITH PRECIPITATION
QUICKLY EXITING THE REGION. DECIDED TO PULL OUT ANY SLIGHT MENTION
OF PRECIPITATION ALONG THE FRINGES OF THE CWA AS THE CWA SEEMS TO
BECOME DRY SLOTTED BY MONDAY NIGHT.
&&
.AVIATION...(FOR THE 18Z KGRI TAF THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 348 PM CDT WED MAY 15 2013
WIND SHOULD DECREASE BY EARLY EVENING AS A FRONT TO THE SOUTH
LIFTS NORTH. THERE IS AN OUTSIDE CHANCE OF A THUNDERSTORM...BUT
THE FOCUS SHOULD BE TO THE SOUTH THROUGH EARLY EVENING...THEN TO
THE NORTH DURING THE OVERNIGHT...WITH VCTS BY THURSDAY AFTERNOON
COMING IN FROM THE WEST. VFR CONDITIONS ARE ANTICIPATED...WITH THE
POSSIBILITY OF SOME MVFR DURING THE EARLY MORNING...BUT THIS IS A
LONGSHOT...SO LEFT OUT OF THE FORECAST FOR NOW.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...HEINLEIN
LONG TERM...SALTZMAN
AVIATION...HEINLEIN
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
650 PM EDT WED MAY 15 2013
.SYNOPSIS...
A COLD FRONT JUST SOUTH OF THE LAKESHORE WILL PUSH INTO CENTRAL OHIO
TONIGHT AND THEN STALL. THE FRONT WILL LIFT NORTH AS A WARM FRONT
THIS WEEKEND.
&&
.NEAR TERM /THROUGH THURSDAY/...
COLD FRONT CURRENTLY SOUTH OF THE LAKESHORE. SHOWERS HAVE ENDED
ACROSS THE SOUTHERN TIER OF COUNTIES. SO HAVE REMOVED THE PRECIP
CHANCES FOR THE REMAINDER OF THE EVENING. DID HOWEVER RE-INTRODUCE
A SLIGHT CHANCE FOR A SHOWER/TS FROM FINDLAY TO MILLERSBURG. HRRR
AND RAP WANT TO PAINT SOME QPF TONIGHT. IT HAS A REASONABLE
PICTURE FOR THE CONDITIONS RIGHT NOW...AND WITH BOUNDARY IN THE
VICINITY AND A LITTLE BIT OF ENERGY UPSTREAM...DID NOT WANT A
COMPLETELY DRY FORECAST. WILL WATCH FOR THIS TONIGHT. FOR TEMPS
WENT UPPER 40S TO THE MID 50S. HOWEVER...BELIEVE THE MODELS
OVERDOING THE CLOUDS TONIGHT...IF THAT IS THE CASE TEMPS WILL BE A
LITTLE LOWER.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
MODELS CONTINUE TO STALL THE FRONT WELL SOUTH OF THE AREA. GFS A
LITTLE SLOWER TODAY MOVING THE FRONT NORTH. EXCEPT FOR THE EXTREME
SW PORTION OF THE FORECAST AREA REMOVED MENTION OF POPS FOR FRIDAY
AND FRIDAY NIGHT. MODELS STILL IN CONFLICT FOR SATURDAY. ECMWF
KEEPS FRONT SOUTH OF THE AREA ON SATURDAY WHILE GFS CONTINUES TO
HAVE THE FRONT ACROSS THE AREA. FOR NOW SEE NO REASON TO START FLIP
FLOPPING FORECASTS THIS FAR OUT WHEN THINGS ARE STILL IN DOUBT. SO
FOR NOW KEPT CHANCE POPS GOING FOR SATURDAY.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
THE RIDGE IS STILL PROGGED TO BUILD ACROSS THE AREA THIS WEEKEND
THROUGH EARLY NEXT WEEK. THE CHANCES OF SHOWERS/STORMS SHOULD
DIMINISH UNDER THE BUILDING RIDGE. CANNOT TOTALLY RULE OUT OUT A
SHOWER OR THUNDERSTORM GIVEN THE OLD FRONTAL BOUNDARY OR SOME
OUTFLOW/MESO BOUNDARY... INCREASING HEAT ETC...BUT FOR THE
MOST PART SUNDAY AND MONDAY SHOULD BE WARM AND MOSTLY RAIN FREE. CUT
BACK ON THE 12 HOUR POP SUNDAY/MONDAY MOSTLY TO 15 TO 25 PERCENT.
THIS WILL BE "SLIGHT CHANCE" IN MOST FORECASTS WHICH DOES NOT SHOW
UP IN MOST OF OUR TEXT FORECASTS (AFTER THE FIRST DAY).
BY THE MIDDLE OF NEXT WEEK THE NEXT FRONT FROM THE WEST SHOULD WORK
INTO THE AREA. IT WILL LIKELY NOT BE IN A HURRY TO MOVE EAST AS A
TROUGH ALOFT IS PROGGED TO BE DEEPENING IN THE MIDDLE OF THE
COUNTRY. WILL HAVE A HIGHER CHANCE OF SHOWERS AND THUNDERSTORMS BY
TUESDAY AND WEDNESDAY. WILL BEGIN TO CUT BACK ON TEMPERATURES BY
NEXT WEDNESDAY GIVEN THE INCREASE IN CLOUDS AND SHOWERS.
FORECAST HIGHS WILL BE ABOVE GUIDANCE GIVEN THE BIG RIDGE AND THE
TIME OF YEAR. HIGHS 75 TO 80 SUNDAY...AROUND 80 OR IN THE LOWER 80S
MONDAY AND TUESDAY...THEN 70S WEDNESDAY. LOWS GENERALLY MID 50S TO
THE LOWER 60S.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
THE WEAK COLD FRONT HAS SLIPPED ACROSS THE LAKE ERIE LAKESHORE AND
SHOULD MAKE SLOW PROGRESS SOUTHEAST DURING THE AFTERNOON/EVENING.
COUNTING ON NO NEW SHOWERS TO DEVELOP WITH THE FRONT AS THE
EARLIER BATCH OF SHOWERS/STORMS IS NOW SOUTHEAST OF THE TAF SITES.
GUSTY WEST WINDS WILL DIMINISH QUICKLY THIS EVENING. PATCHES OF
MID AND HIGH CLOUDS WILL SPREAD IN FROM THE WEST TONIGHT AND
THURSDAY BUT VFR CONDITIONS WILL CONTINUE.
.OUTLOOK... NON-VFR POSSIBLE IN SHOWERS OR THUNDERSTORMS
SATURDAY AND SUNDAY.
&&
.MARINE...
A FAIRLY TIGHT PRESSURE GRADIENT IS IN PLACE ACROSS LAKE ERIE THIS
AFTERNOON EXTENDING FROM LOW PRESSURE APPROACHING JAMES BAY. THIS
TROUGH WILL SHIFT EAST OF THE LAKE THIS EVENING...PUSHING A COLD
FRONT SOUTH ACROSS THE LAKE WITH DECREASING WINDS AND WAVES. THE
SMALL CRAFT ADVISORY WEST OF AVON WILL BE ALLOWED TO EXPIRE AT 4 PM
AND THE ENDING TIME OF 10 PM STILL LOOKS ON TRACK FOR THE EASTERN
PORTION OF THE LAKE.
HIGH PRESSURE WILL SLOWLY BUILD EAST ACROSS THE LAKE FROM THURSDAY
THROUGH THE WEEKEND. TEMPERATURES WILL BE ABOVE NORMAL THROUGH THIS
TIME WITH STABLE CONDITIONS ON THE LAKE. WINDS WILL GENERALLY BE
LESS THAN 15 KNOTS WITH WAVES LESS THAN 2 FEET. LOW PRESSURE WILL
SLOWLY APPROACH THE REGION FROM THE WEST EARLY NEXT WEEK BRINGING
INCREASING CHANCES OF SHOWERS AND THUNDERSTORMS.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR
LEZ146>149.
&&
$$
SYNOPSIS...DJB
NEAR TERM...DJB/OUDEMAN
SHORT TERM...DJB
LONG TERM...KOSARIK
AVIATION...KOSARIK
MARINE...KEC
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1244 PM CDT WED MAY 15 2013
.UPDATE...
18Z AVIATION DISCUSSION UPDATED BELOW.
CURRENT RADAR IMAGERY SHOWS ISOLATED SHOWERS EXTENDING FROM EAST
CENTRAL SOUTH DAKOTA THROUGH SOUTHWEST NORTH DAKOTA. WHILE LITTLE
IN THE WAY OF ADDITIONAL ACCUMULATION TODAY...THE HRRR MODEL HAS
PICKED UP ON THIS VERY WELL AND DOES INDICATE THAT ISOLATED
SHOWERS OR THUNDERSTORMS WILL LINGER ACROSS THE NORTHERN/EASTERN
CWA THIS AFTERNOON. THEREFORE...DID ADD A 20 POP FOR ISOLATED
SHOWERS AND THUNDERSTORMS. THE ONLY OTHER MINOR CHANGE TO THE
FORECAST WAS TO KNOCK DOWN TEMPERATURES A FEW DEGREES UNDER THE
THICKEST CLOUD COVER. WHILE THE CLOUDS ARE EXPECTED TO BREAK APART
THIS AFTERNOON...ITS GOING TO TAKE AWHILE FOR IT TO HAPPEN ACROSS
THE CENTRAL CWA...AND THEREFORE LIMIT SOME OF THE DAYTIME HEATING.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH FRIDAY
PRECIPITATION CHANCES THROUGHOUT THE PERIOD WILL BE THE MAIN
FORECAST CHALLENGE.
SHOWERS AND THUNDERSTORMS ARE CURRENTLY MOVING ACROSS THE CWA THIS
MORNING. RIGHT ENTRANCE REGION OF AN UPPER LEVEL JET ALONG WITH A
WEAK SHORT WAVE TROUGH WILL LIKELY CONTINUE TO PRODUCE THESE LIGHT
SHOWERS THROUGH THE MID MORNING HOURS BEFORE DIMINISHING. THE
LOWER LEVELS ARE RATHER DRY SO WOULD NOT EXPECT A GREAT DEAL OF
MOISTURE REACHING THE GROUND. THIS AFTERNOON AND A BETTER PORTION
OF TONIGHT WILL BE DRY UNTIL THE NEXT SYSTEM MOVES ACROSS THE
REGION LATE TONIGHT THROUGH THURSDAY. THIS STORM SYSTEM APPEARS TO
SPLIT IN TWO WITH THE NORTHERN PORTION TRACKING ACROSS NORTH DAKOTA
AND THE SOUTHERN PORTION MOVING ALONG AND SOUTH OF I-90.
THURSDAY NIGHT LOOKS LIKE THE BEST TIME PERIOD FOR THE DEVELOPMENT
OF SHOWERS AND THUNDERSTORMS...ESPECIALLY FOR THE EASTERN CWA.
ADDITIONAL SHORT WAVE ACTIVITY WILL COMBINE WITH A 35 TO 40 KNOT
LLJ TO RESULT IN CONVECTIVE DEVELOPMENT. SEVERE THUNDERSTORMS DO
NOT APPEAR LIKELY...NEITHER DOES LOCALLY HEAVY RAINFALL.
ASIDE FROM LINGERING CONVECTION DURING THE MORNING HOURS...A
BETTER PORTION OF FRIDAY LOOKS DRY. MID LEVEL TEMPERATURES WILL
WARM THROUGH THE DAY WITH H7 TEMPS REACHING THE UPPER SINGLE
DIGITS. THESE WARM TEMPS SHOULD CAP CONVECTION UNTIL AFTER 00Z
SATURDAY OR JUST BEYOND THE SHORT TERM PORTION OF THE FORECAST.
.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY
AN UPPER LEVEL RIDGE WILL EXIT THE REGION FRIDAY NIGHT AND
SATURDAY AHEAD OF AN APPROACHING TROUGH. SHORTWAVE ENERGY
ASSOCIATED WITH THE TROUGH WILL THEN AFFECT THE NORTHERN PLAINS
THROUGH THE END OF THE PERIOD. THE MODELS ARE IN DECENT AGREEMENT
WITH THE SURFACE PATTERN THROUGH THE DAY MONDAY...THEN BEGIN TO
DIVERGE SOME AS THE ECMWF BRINGS HIGH PRESSURE OVER THE AREA WHILE
THE GFS KEEPS THE LOW IN THE VICINITY LONGER. THERE IS SOME DECENT
INSTABILITY THAT SHOWS UP ACROSS THE WEST FRIDAY NIGHT...AND EVEN
BETTER INSTABILITY ACROSS THE CENTRAL AND EAST SATURDAY NIGHT.
EXPECT THERE COULD BE SOME STRONG TO SEVERE THUNDERSTORMS
SOMEWHERE IN THE AREA BOTH EVENINGS. CANNOT REALLY DISCERN ANY
TIME PERIOD WHEN IT WILL BE COMPLETELY DRY...SO WILL STICK CLOSE
TO ALLBLEND POPS...WHICH ARE GENERALLY IN THE SCHC TO HIGH CHC
CATEGORY THROUGHOUT THE PERIOD.
SATURDAY WILL BE THE WARMEST DAY OF THE PERIOD WITH HIGH
TEMPERATURES GENERALLY IN THE 70S. WILL THEN SEE A COOLING TREND
THROUGH THE REST OF THE PERIOD UNDER MOSTLY CLOUDY SKIES AND WITH
CHANCES OF PRECIPITATION. HIGHS WILL BE IN THE UPPER 60S TO LOWER
70S ON SUNDAY...THEN MAINLY IN THE 60S MONDAY AND TUESDAY.
&&
.AVIATION...
18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
VFR CONDITIONS ARE EXPECTED AT ALL TERMINALS THROUGH THURSDAY
MORNING. ANOTHER SHORT WAVE TROUGH MOVING IN FROM THE WEST WILL
SPREAD MID LEVEL CLOUDS INTO THE REGION LATER TONIGHT AND EAST
THROUGH THURSDAY. ALONG WITH THE CLOUDS WILL COME SOME SCATTERED
SHOWERS/THUNDERSTORMS MAINLY ON THURSDAY. WILL HAVE TO WATCH FOR
THEM TO POSSIBLY AFFECT THE TERMINALS.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...MOHR/SERR
SHORT TERM...SD
LONG TERM...PARKIN
AVIATION...MOHR
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1213 PM CDT WED MAY 15 2013
.UPDATE...
ISSUED AT 1114 AM CDT WED MAY 15 2013
EXTENDED THE POPS FURTHER IN TOWN AND BOOSTED COVERAGE EARLIER
THIS MORNING PRIMARILY ALONG THE HIGHWAY 14 CORRIDOR. SHORT WAVE
ENERGY CONTINUES TO MOVE EASTWARD ALONG WITH A FAIR AMOUNT OF MID
LEVEL BASED FRONTOGENESIS IN THAT AREA. LOOKING UPSTREAM...IT
APPEARS THINGS MAY COOPERATE AND MOVE OUT OF OUR AREA FOR A BULK
OF THE AFTERNOON HOURS...ALLOWING OUR NORTHERN ZONES TO WARM UP.
THAT SAID...DUE TO EXTENSIVE CLOUD COVER THIS MORNING...DID LOWER
SOME HIGHS A CATEGORY OR SO IN EAST CENTRAL SD AND ACROSS THE
NORTHERN PORTIONS OF SOUTHWEST MN. ELSEWHERE...THE HIGH
TEMPERATURES STILL LOOK PRETTY GOOD...ONLY ADJUSTED A FEW OF THEM
A DEGREE OR TWO.
OTHERWISE...SURFACE HIGH PRESSURE AXIS WILL REMAIN VERY CLOSE TO
OUR NORTHERN ZONES THIS AFTERNOON. THIS MAKES THE WIND DIRECTION
RATHER TRICKY FOR THE ON GOING SPOT BURN FORECASTS FOR THOSE
AREAS. IN ADDITION...THERE IS SOME INDICATION WITH THE SHORT
RANGE HIGH RES MODELS THAT THE WIND DIRECTION WILL SHIFT TO THE
NORTH ALONG AND NORTH OF I 90 AS THE AFTERNOON PROGRESSES LIKELY
DUE TO THE RAINFALL. HOWEVER AT THIS TIME...THERE IS NO INDICATION
OF THAT HAPPENING OTHER THAN A LIGHT NORTH WIND AT MADISON.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 428 AM CDT WED MAY 15 2013
LINGERING MID LEVEL BOUNDARY AND SOME WEAKLY UNSTABLE 700-500 HPA
LAPSE RATES CREATING SOME ISSUES WITH THE FORECAST EARLY THIS
MORNING. WAVE TOPPING DEVELOPING RIDGE ALOFT AND NUDGING UP AGAINST
NORTHWEST SOUTH DAKOTA ACTING TO INDUCE SOME CROSS FRONTAL FLOW...
AND WEAK REGION OF HIGH BASED LIFT FROM NORTHWEST TO SOUTHEAST ACROSS
THE STATE. MID LEVEL FRONTOGENETIC FORCING REMAINS FAIRLY STRONG
MAINLY ALONG AND NORTH OF I90 THROUGH THE DAY... WEAKENING SOME BY
AFTERNOON AS WAVE MOVES PAST. VERY DRY LOWER ATMOSPHERE IS CERTAINLY
IMPACTING THE POTENTIAL EASTWARD SPREAD AND OVERALL COVERAGE OF
WETTING RAINFALL. THE HRRR KEEP SLIPPING AWAY ON DEVELOPING
PRECIP...PUSHING IT BACK AT LEAST AN HOUR OR TWO WITH SUCCESSIVE RUN
DESPITE THE INCREASING PRESENCE ON RADAR OVER THE LAST HOUR OR TWO.
HIGH RES MODELS SEEM TO HAVE THE RIGHT IDEA...AND SUPPORT FROM LARGER
SCALE DYNAMICS MENTIONED ABOVE. INDICATIONS ON VARIOUS FORECAST
SOUNDING FROM 100 TO 300 J/K ELEVATED INSTABILITY...SO WOULD NOT BE
SURPRISED TO GET A FEW RUMBLES OF HIGH BASED THUNDER...EVEN WITH THE
OVERALL PROBABILITY/ COVERAGE OF PRECIPITATION LIKELY LACKING...AND
AT THIS POINT NOT WARRANTING MUCH MORE THAN A LOWER SCATTERED
MENTION.
SOME CONCERN THAT LINGERING CLOUDS AND ANY EVAPORATIVE EFFECTS WOULD
HAVE AN IMPACT ON TEMPERATURES TODAY...BUT SHOULD START TO GET AT
LEAST A DECENT AMOUNT OF SUNSHINE AFTER MAIN WAVE SHEARS BY TO THE
NORTH...AND LINGERING DIV Q ACROSS THE SOUTH WEAKENS AS WELL. MIXING
CENTERS AROUND THE MID TO UPPER 70S...AND DID NUDGE THIS JUST A BIT
HIGHER FOR THE FAR WEST.
TONIGHT LOOKS TO BE QUIETEST PERIOD OF THE FORECAST...WITH WEAK MID
TO UPPER LEVEL RIDGING OVER THE AREA TONIGHT AHEAD OF NEXT WAVE. NAM
AND GEM ACTUALLY A BIT FASTER IN BRINGING PRECIP CHANCE BACK INTO
OUR SOUTHWEST LATE TONIGHT...HOWEVER BEST FORCING WITH WARM ADVECTION
AND ADVANCING WAVE APPEARS TO REMAIN FOCUSED JUST WEST OF OUR AREA
THROUGH 12Z AND WILL LEAVE TONIGHT DRY AS A RESULT. LIGHT WINDS AND
RELATIVELY DRY AIR MASS WILL ALLOW FOR FAIR AMOUNT OF RADIATIONAL
COOLING...AND LOWS IN THE LOWER 50S LOOK REASONABLE FOR MOST AREAS.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 428 AM CDT WED MAY 15 2013
MESSY PATTERN THROUGHOUT THE LONG TERM PERIOD OF THIS FORECAST...WITH
DIFFICULTY PINPOINTING ANY PERIOD WHICH COULD BE SIGNIFICANTLY DRIER
THAN ANOTHER.
PERIOD STARTS WITH WARM FRONT AND ASSOCIATED WAVE MOVING ACROSS THE
FORECAST AREA THURSDAY/THURSDAY NIGHT. NAM/GEM/ECMWF QUITE BULLISH IN
PRODUCING FAIR AMOUNT OF PRECIP WITH THIS SYSTEM...WHILE THE GFS IS
MUCH DRIER THOUGH STILL INDICATIVE OF SOME PRECIP CHANCE. 15/00Z NAM
SEEMS TO BE SLIGHT OUTLIER IN SPEED WITH WHICH IS TRACKS THE WAVE AND
ASSOCIATED PRECIP TO THE NORTHEAST ON THURSDAY...AND HAVE GENERALLY
FOLLOWED SLOWER IDEA FOR NOW...KEEPING OUR NORTHEAST COUNTIES DRY
UNTIL THURSDAY EVENING. PERSISTENT WARM ADVECTION WILL THEN LEAD TO
INCREASING PRECIP CHANCE THROUGH THE OVERNIGHT HOURS THURSDAY NIGHT.
TEMPERATURES SHOULD BE SEASONABLE WITH HIGHS THURSDAY IN THE MID TO
UPPER 70S. INCREASING MOISTURE/CLOUD COVER WILL HOLD TEMPERATURES UP
IN THE UPPER 50S THURSDAY NIGHT.
MUCH OF FRIDAY/FRIDAY NIGHT COULD AGAIN BE BETWEEN PERIODS OF MORE
WIDESPREAD/ORGANIZED PRECIPITATION...THOUGH EASTERN AREAS COULD SEE
A FEW THUNDERSTORMS LINGER INTO THE MORNING...WHILE THE WEST HAS A
CHANCE OF DEVELOPMENT FRIDAY NIGHT AS RETURN FLOW OF MOISTURE MOVES
INTO CENTRAL SOUTH DAKOTA. WITH WARM FRONT EXPECTED TO BE NORTH OF
THE AREA BY FRIDAY AFTERNOON...AND GENERAL LACK OF PRECIP ALONG WITH
BREEZY SOUTH WINDS...SHOULD SEE DECENT MIXING TO HELP WARM TEMPS INTO
THE MID 80S ACROSS THE WEST. DESPITE WARMER TEMPS AND POTENTIAL FOR
SOME GUSTY WINDS...DO NOT EXPECT SIGNIFICANT FIRE DANGER FRIDAY AS
WE SHOULD HAVE MUCH HIGHER BOUNDARY LAYER MOISTURE WITH EVEN MIXED
OUT DEW POINTS HOLDING IN THE UPPER 50S TO AROUND 60. THAT MOISTURE
ALONG WITH WEAK LOW LEVEL JET WILL HOLD OVERNIGHT LOWS IN THE LOWER
TO MID 60S FOR FRIDAY NIGHT.
SATURDAY INTO SATURDAY NIGHT CONTINUES TO LOOK LIKE MOST FAVORED
PERIOD FOR ORGANIZED PRECIPITATION ACROSS THE REGION...AS BROAD
WESTERN CONUS TROUGH BEGINS TO SHIFT EASTWARD INTO THE PLAINS.
PRECIP SHOULD INITIALLY BE FOCUSED NEAR BOUNDARY ACROSS CENTRAL
SOUTH DAKOTA BY SATURDAY AFTERNOON...WITH THUNDERSTORMS THEN
EXPANDING EASTWARD ACROSS OUR FORECAST AREA SATURDAY NIGHT. THIS
PERIOD CONTINUES TO BE GREATEST THREAT FOR SEVERE WEATHER FOR OUR
FORECAST AREA...WITH STEEP MID LEVEL LAPSE RATES AND DEEP FORCING
AHEAD OF TROUGH BRINGING POTENTIAL FOR HAIL/WIND.
AS IS TYPICAL IN CONVECTIVE SEASON...MODELS NOT SHOWING A GREAT DEAL
OF AGREEMENT IN TIMING/LOCATION OF BOUNDARIES FROM THIS POINT
FORWARD. HOWEVER...THEY HAVE TRENDED TOWARD A FAVORED SOLUTION IN
CLOSING OFF THE UPPER LOW SOMEWHERE IN THE CENTRAL/NORTHERN PLAINS
BY SUNDAY NIGHT/MONDAY...WITH THE LOW THEN PERSISTING ACROSS THIS
REGION THROUGH MUCH OF EARLY NEXT WEEK. THIS LEADS TO POTENTIAL FOR
AT LEAST SCATTERED PRECIPITATION SUNDAY THROUGH TUESDAY...AND HAVE
NOT STRAYED FAR FROM CONSENSUS GRIDS WHICH HOLD ONTO CHANCE RANGE
POPS FOR THE LONGER RANGE. TEMPERATURES SHOWING LESS AGREEMENT LATE
IN THE PERIOD...WITH LATEST ECMWF WRAPPING MUCH COLDER AIR AROUND THE
BACK SIDE OF THE UPPER LOW BY MONDAY AND ESPECIALLY TUESDAY. FOR NOW
WILL STICK WITH SOMEWHAT MORE MILD GFS/CONSENSUS SOLUTION WHICH...
ALTHOUGH COOLER THAN THE MILD TEMPERATURES EXPECTED THROUGH THE
WEEKEND...WILL KEEP HIGHS IN THE 60S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1212 PM CDT WED MAY 15 2013
ISOLATED THUNDERTORMS WILL CONTINUE TO MOVE EASTWARD GENERALLY
ALONG AND EAST OF THE I 29 CORRIDOR FOR THE NEXT FEW HOURS INTO
MID AFTERNOON. MENTIONED A THUNDERSTORM IN THE VICINITY OF THE
KFSD AIRPORT THROUGH 2 PM...THEN THE ACTIVITY SHOULD PUSH OFF TO
THE EAST. THE SHOWERS AND ISOLATED THUNDERSTORMS ARE VERY HIGH
BASED...COMING OUT OF ACCAS CLOUDS. HOWEVER MODERATE TO STRONG
WINDS ARE NOT EXPECTED UNDER ANY OF THESE SHOWERS. OTHERWISE THE
AREA WILL BE VFR THROUGH THURSDAY MORNING.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...MJF
SHORT TERM...CHAPMAN/JH
LONG TERM...JH
AVIATION...MJF
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1115 AM CDT WED MAY 15 2013
.UPDATE...
ISSUED AT 1114 AM CDT WED MAY 15 2013
EXTENDED THE POPS FURTHER IN TOWN AND BOOSTED COVERAGE EARLIER
THIS MORNING PRIMARILY ALONG THE HIGHWAY 14 CORRIDOR. SHORT WAVE
ENERGY CONTINUES TO MOVE EASTWARD ALONG WITH A FAIR AMOUNT OF MID
LEVEL BASED FRONTOGENESIS IN THAT AREA. LOOKING UPSTREAM...IT
APPEARS THINGS MAY COOPERATE AND MOVE OUT OF OUR AREA FOR A BULK
OF THE AFTERNOON HOURS...ALLOWING OUR NORTHERN ZONES TO WARM UP.
THAT SAID...DUE TO EXTENSIVE CLOUD COVER THIS MORNING...DID LOWER
SOME HIGHS A CATEGORY OR SO IN EAST CENTRAL SD AND ACROSS THE
NORTHERN PORTIONS OF SOUTHWEST MN. ELSEWHERE...THE HIGH
TEMPERATURES STILL LOOK PRETTY GOOD...ONLY ADJUSTED A FEW OF THEM
A DEGREE OR TWO.
OTHERWISE...SURFACE HIGH PRESSURE AXIS WILL REMAIN VERY CLOSE TO
OUR NORTHERN ZONES THIS AFTERNOON. THIS MAKES THE WIND DIRECTION
RATHER TRICKY FOR THE ON GOING SPOT BURN FORECASTS FOR THOSE
AREAS. IN ADDITION...THERE IS SOME INDICATION WITH THE SHORT
RANGE HIGH RES MODELS THAT THE WIND DIRECTION WILL SHIFT TO THE
NORTH ALONG AND NORTH OF I 90 AS THE AFTERNOON PROGRESSES LIKELY
DUE TO THE RAINFALL. HOWEVER AT THIS TIME...THERE IS NO INDICATION
OF THAT HAPPENING OTHER THAN A LIGHT NORTH WIND AT MADISON.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 428 AM CDT WED MAY 15 2013
LINGERING MID LEVEL BOUNDARY AND SOME WEAKLY UNSTABLE 700-500 HPA
LAPSE RATES CREATING SOME ISSUES WITH THE FORECAST EARLY THIS
MORNING. WAVE TOPPING DEVELOPING RIDGE ALOFT AND NUDGING UP AGAINST
NORTHWEST SOUTH DAKOTA ACTING TO INDUCE SOME CROSS FRONTAL FLOW...
AND WEAK REGION OF HIGH BASED LIFT FROM NORTHWEST TO SOUTHEAST ACROSS
THE STATE. MID LEVEL FRONTOGENETIC FORCING REMAINS FAIRLY STRONG
MAINLY ALONG AND NORTH OF I90 THROUGH THE DAY... WEAKENING SOME BY
AFTERNOON AS WAVE MOVES PAST. VERY DRY LOWER ATMOSPHERE IS CERTAINLY
IMPACTING THE POTENTIAL EASTWARD SPREAD AND OVERALL COVERAGE OF
WETTING RAINFALL. THE HRRR KEEP SLIPPING AWAY ON DEVELOPING
PRECIP...PUSHING IT BACK AT LEAST AN HOUR OR TWO WITH SUCCESSIVE RUN
DESPITE THE INCREASING PRESENCE ON RADAR OVER THE LAST HOUR OR TWO.
HIGH RES MODELS SEEM TO HAVE THE RIGHT IDEA...AND SUPPORT FROM LARGER
SCALE DYNAMICS MENTIONED ABOVE. INDICATIONS ON VARIOUS FORECAST
SOUNDING FROM 100 TO 300 J/K ELEVATED INSTABILITY...SO WOULD NOT BE
SURPRISED TO GET A FEW RUMBLES OF HIGH BASED THUNDER...EVEN WITH THE
OVERALL PROBABILITY/ COVERAGE OF PRECIPITATION LIKELY LACKING...AND
AT THIS POINT NOT WARRANTING MUCH MORE THAN A LOWER SCATTERED
MENTION.
SOME CONCERN THAT LINGERING CLOUDS AND ANY EVAPORATIVE EFFECTS WOULD
HAVE AN IMPACT ON TEMPERATURES TODAY...BUT SHOULD START TO GET AT
LEAST A DECENT AMOUNT OF SUNSHINE AFTER MAIN WAVE SHEARS BY TO THE
NORTH...AND LINGERING DIV Q ACROSS THE SOUTH WEAKENS AS WELL. MIXING
CENTERS AROUND THE MID TO UPPER 70S...AND DID NUDGE THIS JUST A BIT
HIGHER FOR THE FAR WEST.
TONIGHT LOOKS TO BE QUIETEST PERIOD OF THE FORECAST...WITH WEAK MID
TO UPPER LEVEL RIDGING OVER THE AREA TONIGHT AHEAD OF NEXT WAVE. NAM
AND GEM ACTUALLY A BIT FASTER IN BRINGING PRECIP CHANCE BACK INTO
OUR SOUTHWEST LATE TONIGHT...HOWEVER BEST FORCING WITH WARM ADVECTION
AND ADVANCING WAVE APPEARS TO REMAIN FOCUSED JUST WEST OF OUR AREA
THROUGH 12Z AND WILL LEAVE TONIGHT DRY AS A RESULT. LIGHT WINDS AND
RELATIVELY DRY AIR MASS WILL ALLOW FOR FAIR AMOUNT OF RADIATIONAL
COOLING...AND LOWS IN THE LOWER 50S LOOK REASONABLE FOR MOST AREAS.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 428 AM CDT WED MAY 15 2013
MESSY PATTERN THROUGHOUT THE LONG TERM PERIOD OF THIS FORECAST...WITH
DIFFICULTY PINPOINTING ANY PERIOD WHICH COULD BE SIGNIFICANTLY DRIER
THAN ANOTHER.
PERIOD STARTS WITH WARM FRONT AND ASSOCIATED WAVE MOVING ACROSS THE
FORECAST AREA THURSDAY/THURSDAY NIGHT. NAM/GEM/ECMWF QUITE BULLISH IN
PRODUCING FAIR AMOUNT OF PRECIP WITH THIS SYSTEM...WHILE THE GFS IS
MUCH DRIER THOUGH STILL INDICATIVE OF SOME PRECIP CHANCE. 15/00Z NAM
SEEMS TO BE SLIGHT OUTLIER IN SPEED WITH WHICH IS TRACKS THE WAVE AND
ASSOCIATED PRECIP TO THE NORTHEAST ON THURSDAY...AND HAVE GENERALLY
FOLLOWED SLOWER IDEA FOR NOW...KEEPING OUR NORTHEAST COUNTIES DRY
UNTIL THURSDAY EVENING. PERSISTENT WARM ADVECTION WILL THEN LEAD TO
INCREASING PRECIP CHANCE THROUGH THE OVERNIGHT HOURS THURSDAY NIGHT.
TEMPERATURES SHOULD BE SEASONABLE WITH HIGHS THURSDAY IN THE MID TO
UPPER 70S. INCREASING MOISTURE/CLOUD COVER WILL HOLD TEMPERATURES UP
IN THE UPPER 50S THURSDAY NIGHT.
MUCH OF FRIDAY/FRIDAY NIGHT COULD AGAIN BE BETWEEN PERIODS OF MORE
WIDESPREAD/ORGANIZED PRECIPITATION...THOUGH EASTERN AREAS COULD SEE
A FEW THUNDERSTORMS LINGER INTO THE MORNING...WHILE THE WEST HAS A
CHANCE OF DEVELOPMENT FRIDAY NIGHT AS RETURN FLOW OF MOISTURE MOVES
INTO CENTRAL SOUTH DAKOTA. WITH WARM FRONT EXPECTED TO BE NORTH OF
THE AREA BY FRIDAY AFTERNOON...AND GENERAL LACK OF PRECIP ALONG WITH
BREEZY SOUTH WINDS...SHOULD SEE DECENT MIXING TO HELP WARM TEMPS INTO
THE MID 80S ACROSS THE WEST. DESPITE WARMER TEMPS AND POTENTIAL FOR
SOME GUSTY WINDS...DO NOT EXPECT SIGNIFICANT FIRE DANGER FRIDAY AS
WE SHOULD HAVE MUCH HIGHER BOUNDARY LAYER MOISTURE WITH EVEN MIXED
OUT DEW POINTS HOLDING IN THE UPPER 50S TO AROUND 60. THAT MOISTURE
ALONG WITH WEAK LOW LEVEL JET WILL HOLD OVERNIGHT LOWS IN THE LOWER
TO MID 60S FOR FRIDAY NIGHT.
SATURDAY INTO SATURDAY NIGHT CONTINUES TO LOOK LIKE MOST FAVORED
PERIOD FOR ORGANIZED PRECIPITATION ACROSS THE REGION...AS BROAD
WESTERN CONUS TROUGH BEGINS TO SHIFT EASTWARD INTO THE PLAINS.
PRECIP SHOULD INITIALLY BE FOCUSED NEAR BOUNDARY ACROSS CENTRAL
SOUTH DAKOTA BY SATURDAY AFTERNOON...WITH THUNDERSTORMS THEN
EXPANDING EASTWARD ACROSS OUR FORECAST AREA SATURDAY NIGHT. THIS
PERIOD CONTINUES TO BE GREATEST THREAT FOR SEVERE WEATHER FOR OUR
FORECAST AREA...WITH STEEP MID LEVEL LAPSE RATES AND DEEP FORCING
AHEAD OF TROUGH BRINGING POTENTIAL FOR HAIL/WIND.
AS IS TYPICAL IN CONVECTIVE SEASON...MODELS NOT SHOWING A GREAT DEAL
OF AGREEMENT IN TIMING/LOCATION OF BOUNDARIES FROM THIS POINT
FORWARD. HOWEVER...THEY HAVE TRENDED TOWARD A FAVORED SOLUTION IN
CLOSING OFF THE UPPER LOW SOMEWHERE IN THE CENTRAL/NORTHERN PLAINS
BY SUNDAY NIGHT/MONDAY...WITH THE LOW THEN PERSISTING ACROSS THIS
REGION THROUGH MUCH OF EARLY NEXT WEEK. THIS LEADS TO POTENTIAL FOR
AT LEAST SCATTERED PRECIPITATION SUNDAY THROUGH TUESDAY...AND HAVE
NOT STRAYED FAR FROM CONSENSUS GRIDS WHICH HOLD ONTO CHANCE RANGE
POPS FOR THE LONGER RANGE. TEMPERATURES SHOWING LESS AGREEMENT LATE
IN THE PERIOD...WITH LATEST ECMWF WRAPPING MUCH COLDER AIR AROUND THE
BACK SIDE OF THE UPPER LOW BY MONDAY AND ESPECIALLY TUESDAY. FOR NOW
WILL STICK WITH SOMEWHAT MORE MILD GFS/CONSENSUS SOLUTION WHICH...
ALTHOUGH COOLER THAN THE MILD TEMPERATURES EXPECTED THROUGH THE
WEEKEND...WILL KEEP HIGHS IN THE 60S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 521 AM CDT WED MAY 15 2013
ELEVATED INSTABILITY AND A DISTURBANCE MOVING ACROSS FAR NORTHERN
SOUTH DAKOTA THIS MORNING WILL CONTINUE TO PRODUCE ISOLATED TO
SCATTERED SHOWERS AND A FEW THUNDERSTORMS ACROSS THE AREA. OTHER
THAN THE IMMEDIATE SHORT TERM AROUND KHON...NOT LIKELY TO HAVE A
HIGH ENOUGH PROBABILITY OF THUNDER TO WARRANT MENTION IN THE TAFS.
DESPITE PRECIPITATION...VERY HIGH BASED NATURE WILL MEAN THAT
CONDITIONS SHOULD REMAIN VFR. THE PRECIPITATION SHOULD MOVE OUT
OF THE IMMEDIATE AREA BY 18Z...AND DRY CONDITIONS ARE EXPECTED
THROUGH 12Z THURSDAY. HOWEVER...SCATTERED THUNDERSTORMS SHOULD BE
POISED SOUTHWEST OF THE KHON AREA TOWARD 12Z MOVING FROM ORIGINS
IN WESTERN NEBRASKA AND SOUTHWEST SOUTH DAKOTA.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...MJF
SHORT TERM...CHAPMAN/JH
LONG TERM...JH
AVIATION...CHAPMAN
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1113 AM CDT WED MAY 15 2013
.UPDATE...
CURRENT RADAR IMAGERY SHOWS ISOLATED SHOWERS EXTENDING FROM EAST
CENTRAL SOUTH DAKOTA THROUGH SOUTHWEST NORTH DAKOTA. WHILE LITTLE
IN THE WAY OF ADDITIONAL ACCUMULATION TODAY...THE HRRR MODEL HAS
PICKED UP ON THIS VERY WELL AND DOES INDICATE THAT ISOLATED
SHOWERS OR THUNDERSTORMS WILL LINGER ACROSS THE NORTHERN/EASTERN
CWA THIS AFTERNOON. THEREFORE...DID ADD A 20 POP FOR ISOLATED
SHOWERS AND THUNDERSTORMS. THE ONLY OTHER MINOR CHANGE TO THE
FORECAST WAS TO KNOCK DOWN TEMPERATURES A FEW DEGREES UNDER THE
THICKEST CLOUD COVER. WHILE THE CLOUDS ARE EXPECTED TO BREAK APART
THIS AFTERNOON...ITS GOING TO TAKE AWHILE FOR IT TO HAPPEN ACROSS
THE CENTRAL CWA...AND THEREFORE LIMIT SOME OF THE DAYTIME HEATING.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH FRIDAY
PRECIPITATION CHANCES THROUGHOUT THE PERIOD WILL BE THE MAIN
FORECAST CHALLENGE.
SHOWERS AND THUNDERSTORMS ARE CURRENTLY MOVING ACROSS THE CWA THIS
MORNING. RIGHT ENTRANCE REGION OF AN UPPER LEVEL JET ALONG WITH A
WEAK SHORT WAVE TROUGH WILL LIKELY CONTINUE TO PRODUCE THESE LIGHT
SHOWERS THROUGH THE MID MORNING HOURS BEFORE DIMINISHING. THE
LOWER LEVELS ARE RATHER DRY SO WOULD NOT EXPECT A GREAT DEAL OF
MOISTURE REACHING THE GROUND. THIS AFTERNOON AND A BETTER PORTION
OF TONIGHT WILL BE DRY UNTIL THE NEXT SYSTEM MOVES ACROSS THE
REGION LATE TONIGHT THROUGH THURSDAY. THIS STORM SYSTEM APPEARS TO
SPLIT IN TWO WITH THE NORTHERN PORTION TRACKING ACROSS NORTH DAKOTA
AND THE SOUTHERN PORTION MOVING ALONG AND SOUTH OF I-90.
THURSDAY NIGHT LOOKS LIKE THE BEST TIME PERIOD FOR THE DEVELOPMENT
OF SHOWERS AND THUNDERSTORMS...ESPECIALLY FOR THE EASTERN CWA.
ADDITIONAL SHORT WAVE ACTIVITY WILL COMBINE WITH A 35 TO 40 KNOT
LLJ TO RESULT IN CONVECTIVE DEVELOPMENT. SEVERE THUNDERSTORMS DO
NOT APPEAR LIKELY...NEITHER DOES LOCALLY HEAVY RAINFALL.
ASIDE FROM LINGERING CONVECTION DURING THE MORNING HOURS...A
BETTER PORTION OF FRIDAY LOOKS DRY. MID LEVEL TEMPERATURES WILL
WARM THROUGH THE DAY WITH H7 TEMPS REACHING THE UPPER SINGLE
DIGITS. THESE WARM TEMPS SHOULD CAP CONVECTION UNTIL AFTER 00Z
SATURDAY OR JUST BEYOND THE SHORT TERM PORTION OF THE FORECAST.
.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY
AN UPPER LEVEL RIDGE WILL EXIT THE REGION FRIDAY NIGHT AND
SATURDAY AHEAD OF AN APPROACHING TROUGH. SHORTWAVE ENERGY
ASSOCIATED WITH THE TROUGH WILL THEN AFFECT THE NORTHERN PLAINS
THROUGH THE END OF THE PERIOD. THE MODELS ARE IN DECENT AGREEMENT
WITH THE SURFACE PATTERN THROUGH THE DAY MONDAY...THEN BEGIN TO
DIVERGE SOME AS THE ECMWF BRINGS HIGH PRESSURE OVER THE AREA WHILE
THE GFS KEEPS THE LOW IN THE VICINITY LONGER. THERE IS SOME DECENT
INSTABILITY THAT SHOWS UP ACROSS THE WEST FRIDAY NIGHT...AND EVEN
BETTER INSTABILITY ACROSS THE CENTRAL AND EAST SATURDAY NIGHT.
EXPECT THERE COULD BE SOME STRONG TO SEVERE THUNDERSTORMS
SOMEWHERE IN THE AREA BOTH EVENINGS. CANNOT REALLY DISCERN ANY
TIME PERIOD WHEN IT WILL BE COMPLETELY DRY...SO WILL STICK CLOSE
TO ALLBLEND POPS...WHICH ARE GENERALLY IN THE SCHC TO HIGH CHC
CATEGORY THROUGHOUT THE PERIOD.
SATURDAY WILL BE THE WARMEST DAY OF THE PERIOD WITH HIGH
TEMPERATURES GENERALLY IN THE 70S. WILL THEN SEE A COOLING TREND
THROUGH THE REST OF THE PERIOD UNDER MOSTLY CLOUDY SKIES AND WITH
CHANCES OF PRECIPITATION. HIGHS WILL BE IN THE UPPER 60S TO LOWER
70S ON SUNDAY...THEN MAINLY IN THE 60S MONDAY AND TUESDAY.
&&
.AVIATION...
12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
AN AREA OF SHOWERS AND WEAK THUNDERSTORMS WILL TRACK ACROSS THE
SOUTHERN HALF OF THE CWA THROUGH THE MORNING HOURS...AFFECTING
KPIR AND KATY. CIGS WILL REMAIN VFR WITH THE PRECIPITATION...BUT
VSBYS MAY BRIEFLY FALL INTO THE MVFR CATEGORY WITH THE
THUNDERSTORMS. THE PRECIPITATION SHOULD EXIT THE AREA BY EARLY
AFTERNOON...THEN VFR CONDITIONS WILL PREVAIL THROUGH THE REMAINDER
OF THE TAF PERIOD.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...SERR
SHORT TERM...SD
LONG TERM...PARKIN
AVIATION...PARKIN
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
1255 PM CDT WED MAY 15 2013
.DISCUSSION...NOTE AVIATION DISCUSSION.
&&
.AVIATION...PREDOMINATE VFR CONDITIONS EXPECTED THIS AFTN EXCEPT
BRIEF MVFR CONDITIONS PSBL NEAR ISOLD SHOWERS/THUNDERSTORMS.
CONVECTION SHOULD END BY THIS EVENING. A TRANSITION TO MVFR
CEILINGS GENERALLY EAST OF U.S. ROUTE 281 AFTER 06Z THURSDAY.
NON-CONVECTIVE LLWS IS ANTICIPATED FOR ALI DRG THE 06-14Z THU
PERIOD. A TRANSITION TO VFR CONDITIONS AREAWIDE AFTER 15Z
THURSDAY. ONSHORE SFC WIND EXPECTED DURING THE TAF PERIOD WITH
MODERATE/BREEZY CONDITIONS THIS AFTN/EARLY EVENING...LIGHT
OVERNIGHT...THEN INCREASING TO MODERATE/BREEZY BY MID MORNING
THURSDAY.
&&
.PREV DISCUSSION... /ISSUED 635 AM CDT WED MAY 15 2013/
DISCUSSION...UPDATED FOR 12Z TAFS.
AVIATION...SHOWERS AND THUNDERSTORMS ARE NOTED AT AND NEAR CRP
AND VCT TAF SITES. LRD AND ALI STILL MAY SEE A FEW SHOWERS IN THE
VICINITY THIS MORNING...BUT MOST OF THE ACTIVITY WILL REMAIN ALONG
THE COAST. MVFR CONDITIONS WILL CONTINUE FOR MOST SITES THROUGH
THE DAY...BUT LRD SHOULD IMPROVE TO VFR. BREEZY CONDITIONS ARE
EXPECTED TO DEVELOP DURING THE DAY.
PREV DISCUSSION... /ISSUED 355 AM CDT WED MAY 15 2013/
SHORT TERM (TODAY THROUGH THURSDAY)...CONTINUING TO WATCH
CONVECTIVE DEVELOPMENT THIS MORNING. SO FAR TWO MAIN AREAS OF
PRECIP...ONE STAYING NORTH OF THE FORECAST AREA...THE OTHER
LARGELY STAYING SOUTH...BOTH ASSOCIATED WITH AN UPPER LEVEL
SHORTWAVE. THE ACTIVITY TO THE SOUTH IS STARTING TO INCLUDE A
NORTHWARD DRIFT ALONG WITH ITS EASTWARD PROGRESSIONS. CLOUD TOPS
ARE ALSO COOLING ACROSS ZAPATA AND JIM HOGG COUNTIES WITH SOME
HIGHER REFLECTIVITY ACTIVITY DEVELOPING. THIS SHOULD PUSH INTO THE
BRUSH COUNTRY AND COASTAL BEND AS THE MORNING GOES ON. STARTING TO
GET SOME ADDITIONAL DEVELOPMENT INTO THE COASTAL BEND AT THIS
TIME.
MODELS CONTINUE TO INDICATE MOISTURE FLUX CONVERGENCE THROUGH THE
AREA THIS MORNING AS WELL. MOST OF GOES SOUNDER PWAT PRODUCT THIS
MORNING IS CONTAMINATED BY CLOUDS...BUT A FEW PIXELS SHOW UP
INDICATING NEARLY 2 INCH PWATS IN THE AREA. 00HR RUC PWAT ANALYSIS
SHOW AS MUCH AS 2.2 INCHES ALONG THE DEEP SOUTH TEXAS COAST. RUC
FORECAST WOULD SUGGEST AROUND 2 INCH VALUES IN TO OUR AREA IN THE
NEXT FEW HOURS. THESE VALUES WOULD BE AROUND THE +2 STANDARD
DEVIATION VALUES FOR THIS TIME OF YEAR. RUC MAY BE A LITTLE HIGH
WITH THESE NUMBERS THOUGH. GFS AND NAM BOTH ARE JUST ABOVE 1.9
INCHES.
HAVE NOT CHANGED POP FORECAST MUCH FOR TODAY...KEEPING A 40 TO 50
POP FOR EASTERN AREAS DURING THE DAY. UPPER LEVEL ENERGY PUSHES
OUT OF THE AREA LATER THIS AFTERNOON ENDING PRECIP CHANCES. HAVE
JUST A LINGERING 20 POP IN THE EAST AFTER 00Z THIS EVENING. MID
LEVEL WAA WILL THEN INCREASE A CAPPING INVERSION OVER THE AREA
TONIGHT INTO THURSDAY.
TEMPERATURES WARM A BIT TODAY IN THE WEST...BUT PRECIP IN THE EAST
COULD KEEP THE BRUSH COUNTRY AND COASTAL BEND AT OR BELOW
YESTERDAYS TEMPS. ADDITIONALLY...A THICK CLOUD COVER LOOKS TO
PERSIST OVER THE AREA WITH STRATUS MAYBE JUST A COUPLE THOUSAND
FEET UP ALL DAY. BY THURSDAY CLOUDS BEGIN TO CLEAR WEST TO EAST
AND SHOULD ALLOW FOR WARMER TEMPS. LAREDO COULD BE NEAR 100.
LONG TERM (THURSDAY NIGHT THROUGH TUESDAY)...STRONG CAP IS IN PLACE
ACROSS SOUTH TEXAS LATE THIS WEEK THROUGH EARLY NEXT WEEK. PWATS
DO INCREASE BACK UP THE RIO GRANDE OVER THE WEEKEND TO NEAR 1.5
INCHES. MODELS INDICATE THE TAIL END OF A WEAK SHORTWAVE MOVING OUT
OF MEXICO AND ACROSS SOUTH TEXAS LATE SATURDAY INTO SUNDAY.
CONVECTION MAY FIRE ALONG THE SIERRA MADRE LATE SATURDAY AFTERNOON
AND MOVE TOWARDS THE RIO GRANDE SATURDAY EVENING...BUT STRENGTH OF
CAP OVER THE REGION MAKES CONFIDENCE IN CONVECTION REACHING WESTERN
CWA LOW...AND THEREFORE NO WX CURRENTLY MENTIONED. OTHERWISE LONG
TERM WILL FEATURE WARM AND DRY CONDITIONS ACROSS SOUTH TEXAS WITH
PERIODS OF BREEZY CONDITIONS. 12Z ECMWF HAD BEEN INDICATE WEAK FRONT
APPROACHING NORTHERN CWA LATE TUESDAY (DAY 7) BUT HAS BACKED OFF TO
THE NORTH IN THE 00Z RUN.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 73 87 74 90 75 / 20 10 10 10 10
VICTORIA 72 85 74 88 73 / 20 10 10 10 10
LAREDO 73 100 73 99 74 / 10 10 10 10 10
ALICE 70 91 73 91 74 / 10 10 10 10 10
ROCKPORT 74 83 74 84 74 / 20 10 10 10 10
COTULLA 71 97 73 98 73 / 10 10 10 10 10
KINGSVILLE 72 89 74 91 75 / 10 10 10 10 10
NAVY CORPUS 74 84 73 84 74 / 20 10 10 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
WC/87...AVIATION