Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/12/14
AREA FORECAST DISCUSSION
NWS NEW YORK NY
702 PM EDT SAT MAY 10 2014
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS LATE TONIGHT. HIGH PRESSURE THEN
BUILDS OVER THE AREA ON SUNDAY AND SUNDAY NIGHT. HIGH PRESSURE
DEPARTS ON MONDAY...AND THEN A SERIES OF FRONTAL BOUNDARIES AND
WEAK LOW PRESSURE SYSTEMS WILL MOVE ACROSS THE REGION THROUGH THE
MIDDLE OF THE WEEK. A STRONGER COLD FRONT IMPACTS THE REGION LATE
NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
SOME BREAK IN CONVECTIVE ACTIVITY WILL BE SEEN ACROSS MUCH OF THE
REGION OUTSIDE OF INTERIOR SOUTHERN CT BEFORE 10 PM. SOME
SCATTERED CONVECTION WILL STILL BE IN THE FORECAST THIS EVENING.
THE CHANCE INCREASES LATER THIS EVENING WHEN ANOTHER AREA OF
SHOWERS WILL BE APPROACHING FROM SOUTH CENTRAL PA. THIS IS MODELED
BY THE HRRR TO MOVE THROUGH BETWEEN 03-07Z. INSTABILITY WILL BE
LOWERING GOING THROUGH THE EVENING...ALLOWING THUNDERSTORMS TO
BECOME LESS IN COVERAGE. OTHERWISE...JUST SOME MINOR ADJUSTMENTS
MADE TO TEMPS AND DEWPOINTS WITH NO OTHER REMARKABLE CHANGES MADE.
THROUGH EARLY THIS EVENING...MAIN THREAT WITH ANY THUNDERSTORMS
WILL BE BRIEF GUSTY WINDS AND HEAVY DOWNPOURS.
FOR THE NEXT FEW ROUNDS OF CONVECTION BACK IN PA THROUGH CENTRAL
NY...THEY WILL BE ARRIVING INTO A COOLER BUT STILL MOIST AIRMASS
LATER THIS EVENING. EXPECTING THE THUNDERSTORMS TO BE LESS
COVERAGE GOING TO MID TO LATE EVENING AS TEMPERATURES COOL AND
FORCING JUST REMAINS AHEAD OF THE SHORTWAVE AND COLD FRONT AT THE
SURFACE. THE JET STREAM ALOFT WILL MOVE NEAR THE REGION THIS
EVENING AND SHOULD KEEP DIVERGENCE GOING ALOFT...ALLOWING FOR A
HIGHER CHANCE OF PRECIP.
ALSO...WITH RATHER LIGHT WESTERLY FLOW BEHIND THE FRONT...THINKING
LOW LEVELS WILL BE SLOWER TO DRY OUT LATE TONIGHT.
THEREFORE...HAVE PATCHY FOG DEVELOPING LATE. LOWS WERE A BLEND OF
NAM12 AND MET GUIDANCE...HIGHER SIDE OF GUIDANCE.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
BEHIND THE COLD FRONT...MID LEVEL RIDGING WITH HIGH PRESSURE
BUILDING IN AT THE SURFACE FROM THE SOUTH AND WEST WILL PROMOTE
DRY WEATHER DURING THIS PERIOD. WITH THE WESTERLY FLOW
SUNDAY...EXPECTING A QUICK INCREASE TO TEMPERATURES IN THE MORNING
WITH HIGHS WELL ABOVE NORMAL ONCE AGAIN...IN THE MID 70S TO LOWER
80S RANGE FOR MOST PLACES. THE JET STREAM ALOFT WILL BE LIFTING
FARTHER NORTH OF THE REGION WITH THE RIDGING. HIGHS WERE TAKEN
FROM MAVS AND INCREASED TWO DEGREES. SKIES WILL BE CLEARING SUNDAY
AND THESE MOSTLY CLEAR SKIES LINGER INTO SUNDAY NIGHT. LOWS SUNDAY
NIGHT WILL BE COOLER THAN OF RECENT NIGHTS WITH RADIATIONAL
COOLING AS WINDS WILL BE LIGHT. LOWS SUNDAY NIGHT WERE TAKEN FROM
ECS AND CONVEY A RANGE FROM THE MID 40S ACROSS RURAL AND INTERIOR
LOCATIONS TO THE LOWER 60S NEAR NYC.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
HIGH PRES DEPARTS ON MONDAY AS A DEEP UPPER TROUGH DIGS INTO THE
CENTRAL U.S. THIS TROUGH WILL EXTEND FROM CANADA INTO THE GULF OF
MEXICO...AND SFC LOW PRES WILL DEVELOP OVER THE WESTERN GREAT LAKES
BEFORE TRACKING TO THE NORTHEAST INTO CANADA. MEANWHILE...A WARM
FRONT APPROACHES ON MONDAY...AND THEN WEAK LOW PRES FORMS ALONG THE
BOUNDARY AS IT LIFTS TO THE NORTH. THAT BOUNDARY WILL BECOME NEARLY
STATIONARY NORTH OF THE REGION ON TUESDAY. AS A RESULT...WILL EXPECT
SCATTERED SHOWERS AND TSTMS TO DEVELOP MONDAY AFTERNOON...MAINLY
ACROSS NORTHERN ZONES. UNSETTLED WEATHER CONTINUES INTO TUESDAY AS
HIGH PRES OVER EASTERN CANADA DROPS SOUTH INTO THE GOLF OF MAINE.
THE STATIONARY FRONT NORTH OF THE AREA WILL PUSH TO THE SOUTH AS A
BACK DOOR COLD FRONT...AND THEN THE HIGH ANCHORS ITSELF OVER THE
WESTERN ATLANTIC THROUGH THE END OF THE WEEK.
THE UPPER TROUGH OVER THE MIDWEST WILL SLOWLY TRACK EAST...BUT WILL
EFFECTIVELY BECOME BLOCKED BY THE OFFSHORE HIGH. SEVERAL WEAK
IMPULSES WILL DEVELOP AT THE BASE OF THE TROUGH...AND THOSE WILL
TRACK TOWARDS THE REGION...KEEPING UNSETTLED WEATHER IN THE FORECAST
THROUGH THE END OF THE WEEK.
THE HIGH MOVES TO THE EAST THURSDAY NIGHT...AND THEN THE UPPER
TROUGH MOVES INTO THE EASTERN U.S. THERE ARE SOME INDICATIONS THAT
THE TROUGH BECOMES NEGATIVELY TILTED...AND THEN LOW PRES WILL
DEVELOP OVER THE MID-ATLANTIC BEFORE MOVING THROUGH THE REGION
THURSDAY NIGHT THROUGH FRIDAY. WILL BUMP UP POPS TO LIKELY FOR MOST
OF THE REGION FOR THAT TIME FRAME. COULD BE SOME LINGERING SHOWERS
INTO SATURDAY AS SEVERAL STRONG SHORTWAVES DIVE INTO THE REGION AS
THE TROUGH MOVES OVERHEAD.
SUMMER-LIKE TEMPS CONTINUE ON MONDAY WITH HIGHS WELL ABOVE
NORMAL...TOPPING OFF IN THE LOW 80S WEST OF THE HUDSON RIVER AND IN
THE MID TO UPPER 70S MOST ELSEWHERE...AND COOLER NEAR THE COASTS.
TEMPS RETURN CLOSER TO NORMAL ON TUESDAY...TOPPING OFF IN THE UPPER
60S TO LOWER 70S WITH THE WARMEST TEMPS ONCE AGAIN WEST OF THE
HUDSON RIVER. BY WEDNESDAY...BEHIND THE BACK DOOR COLD FRONT AND
WITH ONSHORE FLOW...HIGHS WILL RANGE FROM THE UPPER 50S NEAR THE
COASTS TO THE MID 60S ACROSS THE INTERIOR. TEMPS WILL THEN TOP OFF
AROUND NORMAL TO CLOSE OUT THE WEEK...GENERALLY IN THE UPPER 60S.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS THIS AFTN INTO THE EVENING. A COLD FRONT APPROACHES
AND PASSES TONIGHT...BRINGING PERIODS OF SUB-VFR CONDITIONS.
SW FLOW THIS AFTN/EVENING...GENERALLY 8-13 KTS. OCNL GUSTS PSBL
18-25 KTS. GUSTS WILL SUBSIDE AFTR 00Z.
VIS MAINLY P6SM...THOUGH ANY PCPN COULD DROP VIS TO 3-5SM FOR A PERIOD.
CIGS MAINLY VFR...WITH INCREASING MID AND HIGH LEVEL CLOUDS. CIGS
COULD DROP TO 1500-2500 FT WITH ANY PCPN. PSBL STRATUS OVER
EASTERN AREAS AS WELL THIS EVENING AHEAD OF FRONTAL PASSAGE.
FIRST ROUND OF PCPN PSBL AFTR 19Z...WITH HIGHER CONFIDENCE OF THE
21-01Z TIME FRAME. MAINLY SHRA BUT COULD SEE ISO TSTM...LOW
CONFIDENCE OF COVERAGE/TIMING AT THIS TIME AND WILL NOT INCLUDE.
ANOTHER ROUND OF PCPN THIS EVENING/EARLY OVERNIGHT RIGHT AHEAD OF
FRONT...MAINLY SHRA. WILL BRING SUB-VFR CONDITIONS FOR BOTH
VIS/CIGS. WINDS SHIFT BEHIND FRONT AFTR 06Z TO WNW FLOW.
.OUTLOOK FOR 18Z SUN THROUGH THURSDAY...
.SUN-MON...VFR WITH W/NW FLOW.
.MON NIGHT-THURS...PERIODS OF MVFR OR LOWER WITH PCPN.
&&
.MARINE...
PATCHY FOG CAN BE EXPECTED ACROSS THE WATERS TONIGHT WITH MOIST
LOW LEVELS. SCA CONDITIONS STILL EXPECTED FOR THE OCEAN BUT
SYNOPTIC GUSTS WILL BE MARGINAL...NEAR 25 KT BUT FREQUENCY MAY BE
MORE OCCASIONAL WITH THIS. HOWEVER...EXPECTING THE INCREASING SW
FETCH WILL HELP BUILD SEAS AS WELL TO 5 FT ACROSS THE OCEAN ZONES.
JUST EASTERN OCEAN ZONES HAVE SCA CONDITIONS THROUGH TONIGHT WITH
WESTERN OCEAN UNTIL MIDNIGHT. FOR SUNDAY AND SUNDAY NIGHT...SUB
SCA CONDITIONS ARE EXPECTED WITH HIGH PRESSURE IN CONTROL.
SUB-SCA CONDITIONS ON TAP FOR THE START THE NEW WEEK. BY THE MIDDLE
OF NEXT WEEK...SMALL CRAFT CONDITIONS RETURN AS A PERSISTENT ONSHORE
FLOW WILL HELP PUSH OCEAN SEAS UP TO 3-5 FT.
&&
.HYDROLOGY...
AROUND THREE TENTHS TO A HALF INCH OF BASIN AVERAGE QPF IS
EXPECTED THROUGH TONIGHT WITH SOME HIGHER AMOUNTS FROM CONVECTION.
ANY FLOODING POTENTIAL IS EXPECTED TO BE GENERALLY
MINOR...PARTICULARLY FOR THOSE LOCATIONS GETTING MULTIPLE ROUNDS
OF SHOWERS AND THUNDERSTORMS.
SCATTERED SHOWERS/TSTMS COULD PRODUCE LOCALLY HEAVY RAIN FOR MOST OF
THE UPCOMING WEEK...BUT WIDESPREAD ORGANIZED PRECIPITATION OF 1/2"
QPF OR MORE WILL HOLD OFF UNTIL LATE NEXT WEEK WHEN LOW PRESSURE
TRACKS THROUGH THE REGION.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ355.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT SUNDAY FOR ANZ350-353.
&&
$$
SYNOPSIS...JM/MPS
NEAR TERM...JM
SHORT TERM...JM
LONG TERM...MPS
AVIATION...SEARS
MARINE...JM/MPS
HYDROLOGY...JM/MPS
AREA FORECAST DISCUSSION
NWS ALBANY NY
423 AM EDT SAT MAY 10 2014
.SYNOPSIS...
A WARM FRONT WILL CONTINUE TO LIFT ACROSS THE REGION
DURING THE MORNING HOURS WITH SOME SHOWERS AND ISOLATED
THUNDERSTORMS. LATER DURING THE DAY TODAY...A WEAK COLD FRONT WILL
CROSS THE REGION...BRINGING SOME ADDITIONAL SHOWERS AND
THUNDERSTORMS TO THE AREA FOR THIS AFTERNOON INTO THIS EVENING. HIGH
PRESSURE WILL BUILD IN FOR TOMORROW WITH FAIR AND MILD WEATHER. A
FRONTAL BOUNDARY APPROACHING FROM THE NORTH WILL RETURN THE THREAT
FOR SOME RAIN SHOWERS ON MONDAY...WITH CONTINUED WARM TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 423 AM EDT...AN UPPER LEVEL SHORTWAVE TROUGH IS SITUATED
OVER THE GREAT LAKES. AHEAD OF THIS SYSTEM...A MOIST SW FLOW RIGHT
OUT OF THE GULF OF MEXICO IS TRANSPORTING PLENTY OF AMPLE MOISTURE
TOWARDS UPSTATE NY AND NEW ENGLAND. PWAT VALUES WERE AROUND 1.00
INCH ON THE 00Z KALY SOUNDING...AND MODELS PROJECTIONS SHOW THIS
RISING TO NEARLY 1.50 INCHES AT ALBANY TOWARDS SUNRISE...WHICH
WOULD BE NEARING ABOUT 2 STD ABOVE NORMAL.
AT THE SURFACE...A NORTH TO SOUTH ORIENTED WARM FRONT OVER CENTRAL
NEW YORK IS FINALLY MAKING ITS WAY ACROSS OUR REGION FROM WEST TO
EAST. THIS WARM FRONT HAS BEEN HUNG UP JUST SOUTH AND WEST OF OUR
AREA FOR NEARLY TWO DAYS...AND IS FINALLY GETTING THE PUSH IT
NEEDS TO OVERCOME THE STABLE MARINE LAYER THAT HAS BEEN IN PLACE
ACROSS OUR AREA. A WIDESPREAD AREA OF SHOWERS AND EMBEDDED
THUNDERSTORMS ARE CURRENTLY MOVING ACROSS THE NORTHERN PART OF THE
AREA...AND THIS LOOKS TO CONTINUE FOR THE NEXT FEW HOURS AS THE
WARM FRONT MOVES ACROSS THE REGION THIS MORNING. WHILE SOME
SHOWERS OR ISOLATED THUNDERSTORMS ARE POSSIBLE EVERYWHERE...RADAR
TRENDS AND HIRES MODEL OUTPUT FROM THE 3KM HRRR AND LOCAL WRF ALL
SUGGEST THAT NORTHERN HALF OF THE AREA WILL HAVE THE MOST
CONCENTRATED ACTIVITY. ANY THUNDER LOOKS RATHER ISOLATED DUE TO
THE STABLE LOW LEVELS...BUT WITH SHOWALTER VALUES CLOSE TO ZERO...THERE
MAY BE JUST ENOUGH ELEVATED INSTABILITY FOR A FEW RUMBLES OF
THUNDER HERE AND THERE.
THE WARM FRONT SHOULD BE THROUGH BY THE MID TO LATE MORNING...AND
THERE SHOULD BE BREAK IN THE ACTIVITY. THE COLD FRONT WILL REMAIN
UPSTREAM OVER THE EASTERN GREAT LAKES...AND WITH OUR REGION IN THE
WARM SECTOR...WE WILL HAVE A MILD DAY. ALTHOUGH THERE WILL BE
PLENTY OF LOW STRATUS TO START THE DAY...SOME BREAKS OF SUNSHINE SHOULD
OCCUR BY THE LATE MORNING OR EARLY AFTERNOON...AND DECENT MIXING
WILL OCCUR...AS A S-SW BREEZE AT LOW LEVELS WILL BE IN PLACE. MAX
TEMPS LOOK TO REACH WELL INTO THE 70S FOR VALLEY LOCATIONS...WITH
UPPER 60S OVER THE HIGH TERRAIN.
WITH THE COLD FRONT PASSING THROUGH LATE IN THE DAY...THERE LOOKS
TO BE SOME ADDITIONAL SCATTED SHOWERS AND THUNDERSTORMS...MAINLY
FOR AREAS FROM THE CAPITAL REGION ON SOUTH. WITH THE BREAKS OF
SUN...THERE MAY BE BETTER INSTABILITY THAN EARLIER IN THE DAY TO
ALLOW FOR A LITTLE MORE THUNDER. STILL...NO SEVERE WX IS
ANTICIPATED...AS INSTABILITY WILL BE MEAGER...AND LOW
DEWPOINTS/WEAK FORCING WILL PREVENT ANY STORM FROM BECOMING TOO
STRONG. THE THREAT FOR SHOWERS/TSTMS WILL END FROM NORTH TO SOUTH
DURING THE EVENING AS THE COLD FRONT PASSES THROUGH THE AREA.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
ANY LINGERING SHOWERS DOWN SOUTH WILL END SHORTLY AFTER SUNSET
THIS EVENING AS THE COLD FRONT STARTS TO SHIFT SOUTH AND EAST OF
THE REGION...AND HIGH PRESSURE BEGINS TO BUILD IN FROM THE GREAT
LAKES. CLOUDS WILL CLEAR OUT AND A COOLER AND LESS HUMID NIGHT IS
EXPECTED TONIGHT...WITH LOWS IN THE 40S TO LOW 50S.
DRY AND PLEASANT WEATHER IS EXPECTED ON SUNDAY WITH LOW HUMIDITY
AND DEEP MIXING. WESTERLY WINDS WILL BE BREEZY WITH PLENTY OF
SUNSHINE...AND MAX TEMPS LOOK TO REACH INTO THE 70S FOR MANY
AREAS. WITH HIGH PRESSURE NEARBY...DRY WEATHER WILL CONTINUE AND MIN
TEMPS WILL BE COOL FOR SUNDAY NIGHT...WITH UPPER 30S TO UPPER 40S
ACROSS THE REGION.
ANOTHER FRONTAL BOUNDARY LOOKS TO DROP ACROSS THE REGION FOR
MONDAY. THIS BOUNDARY WILL BE RATHER WEAK...BUT WITH DAYTIME
HEATING...SOME SHOWERS WILL BE POSSIBLE BY THE AFTN HOURS.
TEMPERATURES WILL VARY ACROSS THE REGION THANKS TO THE BOUNDARY...AS
NORTHERN AREAS MAY ONLY REACH THE UPPER 60S TO LOW 70S...WHILE
SOUTH OF THE BOUNDARY ACROSS THE MID HUDSON VALLEY...MAX TEMPS MAY
REACH IN THE LOW 80S. THE BEST CHC OF SEEING A SHOWER WILL BE
ACROSS THE ADIRONDACKS. WE WONT INCLUDE THUNDER JUST YET...AS
INSTABILITY AND DEEP MOISTURE DOESN/T LOOK TOO HIGH JUST
YET...LIMITING THE THUNDER THREAT.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MOST OF THE UPCOMING WEEK WILL BE UNSETTLED AS UPPER PATTEN BECOMES
INCREASINGLY AMPLIFIED ACROSS NOAM.
MONDAY NIGHT...
CENTRAL CONUS WILL BECOME UNDER THE INFLUENCE OF AN AMPLIFYING UPPER
TROUGH. MEANWHILE...RIDGE WILL AMPLIFY ACROSS JAMES/HUDSON BAY AND
JUST OFF THE SOUTHEAST CONUS. THIS WILL SET THE STAGE FOR AN ACTIVE
WARM FRONT TO BE SITUATED IN THE VICINITY OF THE LOCAL REGION WITH
AN INCREASING PROBABILITY FOR SHOWERS AND THUNDERSTORMS. GUIDANCE
NUMBERS ARE CLOSE TO WPC GUIDANCE AND WAS FOLLOWED.
TUESDAY AND TUESDAY NIGHT...
GLOBAL MODEL TRENDS ARE TO STRENGTHEN THE UPPER RIDGE AND RISING
SURFACE PRESSURES ACROSS NEW ENGLAND AND INTO PORTIONS OF THE MID
ATLANTIC. THIS WILL LIKELY RESULT IN A SLOWER FORWARD PROGRESS OF
THE WARM FRONT. AT THIS TIME...IT APPEARS LOCATIONS EAST OF THE
HUDSON RIVER WILL SEE A DIMINISHING THREAT FOR WET WEATHER WITH
WESTERN AREAS REMAINING UNDER THE INFLUENCE OF THE WARM FRONT.
HOWEVER...THE UPPER RIDGE WILL BE BUILDING WITH RISING HEIGHTS WHICH
SUGGESTS ANY SHOWERS WILL BE RATHER SCATTERED. IT SHOULD BE RATHER
MILD AND A BIT MORE HUMID WITH MANY AREAS CLIMBING WELL INTO THE 60S
AND OVERNIGHT LOWS MAINLY INTO THE 50S.
WEDNESDAY...
THE UPPER RIDGE AXIS SLIDES JUST TO THE EAST WITH LOW LEVEL FLOW
TRAJECTORIES FORECAST TO ORIGINATE FROM THE SOUTHEAST. THIS SHOULD
ALLOW FOR AN INCREASE INFLUENCE FROM THE ATLANTIC OCEAN TO BRING
ABOUT A MARINE INFLUENCE. SO ADDITIONAL CLOUD COVER AND THE THREAT
FOR ADDITIONAL SHOWERS AND PERHAPS A THUNDERSTORM WITH HIGHS ONCE
AGAIN WELL INTO THE 60S TO NEAR 70 FOR VALLEY LOCATIONS.
WEDNESDAY NIGHT INTO THURSDAY...
THIS IS WHERE THE GLOBAL MODELS DIFFER WITH TIMING AND PLACEMENT OF
THE APPROACHING COLD FRONT. THE 00Z/GFS REMAINS THE MOST
PROGRESSIVE DURING THIS TIME FRAME WITH THE 00Z/ECMWF AND 18Z/0509
DGEX KEEPING THE FRONT FURTHER UPSTREAM AS RIDGE STRENGTHENS OVER
THE WESTERN ATLANTIC. THE GGEM IS SOMEWHAT OF A COMPROMISE WITH A
LITTLE SLOWER FORWARD PROGRESSION OF THE COLD FRONT BUT STILL
KEEPING CLOUDS AND THE THREAT FOR CONVECTION IN THE FORECAST.
THURSDAY NIGHT INTO FRIDAY...
EVENTUALLY THE UPPER TROUGH UPSTREAM WILL BECOME NEGATIVELY TILTED
AND ADVECT IN A HEALTHY AREA OF HIGHER PWATS INTO THE REGION. THIS
APPEARS TO BE THE BEST CHANCE FOR A MORE WIDESPREAD
SHOWERS/THUNDERSTORMS OR A PERIOD OF RAIN FOR ENTIRE REGION. AT
THIS TIME...IT DOES APPEAR THIS WILL BE RATHER PROGRESSIVE TO LIMIT
TOO MUCH RAIN BUT THIS WILL NEED TO BE MONITORED CLOSELY. STILL
RATHER MILD BUT NOT FULLY REALIZING THE VERY WARM TEMPS ALOFT DUE TO
LIMITED MIXING AND CLOUD COVER.
OVERALL...PRECIPITATION TRENDS ARE TOWARD ABOVE NORMAL WITH
TEMPERATURES NEAR NORMAL.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
THE REGION REMAINS WELL ENTRENCHED IN A MARINE TYPE ENVIRONMENT WITH
MVFR/IFR CIGS WITH AN OCCASIONAL DRIZZLE BEING OBSERVED. REGIONAL
RADAR REVEALS A BAND OF SCT-BKN SHOWERS OVER WESTERN NEW YORK THAT
WILL MOVE ACROSS THE TERMINALS DURING THE OVERNIGHT PERIOD. PER
EXPERIMENTAL REFLECTIVITIES FORECASTS...MOST OF THE SHOWERS SHOULD
BE DEPARTING BETWEEN 11-13Z AND HAVE FORECAST THIS WITHIN THE TAFS.
THERE IS A SMALL CHANCE FOR THUNDER BUT CONFIDENCE IS TOO LOW TO
MENTION IN THE FORECAST.
IN THE WAKE OF THE SHOWERS...MAIN FRONT REMAINS UPSTREAM AND WITH
THE DAYTIME HEATING...ADDITIONAL SHOWERS WILL BE POSSIBLE AS WE WILL
PLACE A VCSH IN THE TAFS AT THIS TIME. THE CHANCE FOR SHOWERS WILL
QUICKLY DISSIPATE CLOSE TO SUNSET WITH IMPROVING AVIATION CONDITIONS
INTO THE SATURDAY EVENING HOURS.
WINDS WILL BE SOUTHEAST AROUND 10 KTS WITH SOME OCCASIONAL HIGHER
GUSTS...BECOMING SOUTHWESTERLY SATURDAY MORNING AND INCREASING TO
AROUND 10-15 KT WITH SOME HIGHER GUSTS INTO THE 20 KT RANGE.
OUTLOOK...
SUNDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
MONDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
MONDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
TUESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
TUESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
WEDNESDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA...TSRA.
WEDNESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
THURSDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
&&
.FIRE WEATHER...
A FRONTAL SYSTEM MOVING ACROSS THE REGION WILL BRING SHOWERS AND
THUNDERSTORMS TODAY. RH VALUES WILL ONLY DROP TO 40 TO 55 PERCENT
THIS AFTERNOON ALONG WITH S-SW WINDS OF 10 TO 15 MPH. RH VALUES WILL
RECOVER TO NEAR 100 PERCENT TONIGHT WITH WEST WINDS OF 5 TO 10 MPH.
DRY WEATHER IS EXPECTED ON SUNDAY...WITH RH VALUES DROPPING AS LOW
AS 25 TO 35 PERCENT IN THE AFTERNOON HOURS. WINDS ON SUNDAY ARE
EXPECTED TO BE WEST AT 10 TO 20 MPH...WITH THE HIGHEST SPEEDS IN THE
AFTERNOON.
&&
.HYDROLOGY...
NO WIDESPREAD HYDROLOGIC ISSUES ARE EXPECTED OVER THE NEXT SEVERAL
DAYS.
A FRONTAL SYSTEM WILL CONTINUE TO BRING SOME SHOWERS AND
THUNDERSTORMS TODAY. THE THREAT FOR RAIN WILL END BY LATE THIS
EVENING AS THE COLD FRONT CROSSES THE ENTIRE AREA. HIGH PRESSURE
WILL ALLOW FOR DRY WEATHER ON SUNDAY...BUT A WEAK FRONT DROPPING
FROM THE NORTH WILL RETURN THE THREAT FOR SOME SCATTERED LIGHT RAIN
SHOWERS ON MONDAY. THERE WILL BE A THREAT FOR ADDITIONAL SHOWERS AND
THUNDERSTORMS INTO THE MIDDLE OF NEXT WEEK...AS THE FRONTAL BOUNDARY
REMAINS NEARBY THE AREA.
RAINFALL TODAY MAY ALLOW FOR SOME MINOR RISES ON RIVERS AND
STREAMS...BUT ALL WATERWAYS ARE EXPECTED TO REMAIN WITHIN THEIR
BANKS. ALTHOUGH PRECIPITATION NEXT WEEK WILL INITIALLY BE SCATTERED
AND LIGHT IN NATURE...WE WILL HAVE TO WATCH MODELS TRENDS CLOSELY
FOR LATER IN THE WEEK...AS MORE CONCENTRATED AND HEAVIER RAINFALL
COULD EVENTUALLY OCCUR SOMEWHERE IN OR NEAR OUR AREA.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS
NEAR TERM...FRUGIS
SHORT TERM...FRUGIS
LONG TERM...BGM
AVIATION...BGM
FIRE WEATHER...FRUGIS
HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS ALBANY NY
130 AM EDT SAT MAY 10 2014
.SYNOPSIS...
A WARM FRONT WILL CONTINUE TO LIFT ACROSS THE REGION
DURING THE EARLY MORNING HOURS WITH SOME SHOWERS AND ISOLATED
THUNDERSTORMS. LATER DURING THE DAY ON SATURDAY...A WEAK COLD FRONT
WILL CROSS THE REGION...BRINGING SOME ADDITIONAL SHOWERS AND
THUNDERSTORMS TO THE AREA. HIGH PRESSURE WILL BUILD IN FOR SUNDAY
WITH FAIR AND MILD WEATHER.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 130 AM EDT...A WARM FRONT OVER CENTRAL NEW YORK IS CONTINUING TO
MOVE EASTWARD TOWARDS OUR AREA. THE FRONT...WHICH HAD BEEN STALLED
FOR MUCH OF THE DAY FRIDAY OVER WESTERN NEW YORK...IS NOW LOCATED
JUST WEST OF OUR CWA. A BATCH OF SHOWERS ASSOCIATED WITH THIS
BOUNDARY IS JUST NOW ENTERING THE WESTERN MOHAWK VALLEY AND
WESTERN ADIRONDACKS. MUCH OF OUR AREA CONTINUES TO BE REMAIN
SOCKED IN WITH LOW STRATUS CLOUDS COURTESY OF A MARINE INFLUENCE
WITH A SOUTHEAST FLOW OFF THE OCEAN. THE STRATUS DECK WILL LINGER
THROUGH THE OVERNIGHT HOURS WITH A STRONG LOW LEVEL INVERSION IN PLACE.
MID LEVEL LAPSE RATES ABOVE THE INVERSION ARE FAIRLY STEEP SO
WILL CONTINUE TO MENTION A SLIGHT CHANCE OF THUNDER OVERNIGHT. HI
RES MODELS...SUCH AS THE HRRR AND LOCAL WRF...CONTINUE TO INDICATE A
FAIRLY WIDESPREAD BATCH OF SHOWERS WITH EMBEDDED THUNDER MOVING
ACROSS THE AREA INTO EARLY SATURDAY MORNING ASSOCIATED WITH THE
PASSAGE OF THE SURFACE WARM FRONT AND UPPER LEVEL HEIGHT
FALLS...SO POPS WILL RISE THROUGH THE OVERNIGHT HOURS.
OVERNIGHT TEMPERATURES WILL MAINLY HOLD STEADY AND REMAIN NEAR
CURRENT READINGS...WITH UPPER 50S TO MID 60S ACROSS THE REGION.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY NIGHT/...
AS THE WEAK COLD FRONT CROSSES THE REGION SATURDAY...THE SHOWERS
WILL COME TO AN END ACROSS THE FAR NORTHWEST PART OF THE FORECAST
AREA DURING THE AFTERNOON...BUT SHOWER/TSTM ACTIVITY WILL CONTINUE
ACROSS THE SOUTH AS A WEAK UPPER LEVEL WAVE RIDES ALONG THE FRONTAL
BOUNDARY DURING THE AFTERNOON AND EVENING. THIS WILL KEEP THE THREAT
OF SHOWERS/TSTMS IN THESE AREAS GOING WELL INTO SATURDAY EVENING.
BY LATE SATURDAY NIGHT THE SHOWERS WILL END IN ALL AREAS. HIGHS
SATURDAY WILL BE IN THE UPPER 60S AND 70S. LOWS SATURDAY NIGHT
IN THE 40S TO LOWER 50S.
HIGH PRESSURE WILL BUILD IN ON SUNDAY WITH FAIR AND MILD WEATHER. IT
WILL BE MOSTLY SUNNY WITH HIGHS IN THE UPPER 60S TO MID 70S.
CLOUDS WILL BEGIN TO INCREASE AGAIN SUNDAY NIGHT AS OVERUNNING
MOISTURE QUICKLY OVERSPREADS THE REGION AND A BACK DOOR COLD FRONT
TRIES TO SLIP SOUTH INTO THE AREA BY MONDAY MORNING. HOWEVER...NO
PCPN HAS BEEN FORECAST FOR SUNDAY NIGHT. LOWS WILL BE IN THE UPPER
40S TO MID 50S.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
MUCH OF THE LONG TERM PERIOD LOOKS TO FEATURE UNSETTLED
WEATHER...ALTHOUGH THERE WILL ALSO BE PERIODS OF PRECIP-FREE
CONDITIONS. MONDAY WILL CONTINUE TO BE WARMER THAN NORMAL WITH A
WEAK SURFACE TROUGH PROVIDING THE FOCUS FOR SOME WIDELY SCATTERED
DIURNAL SHOWERS AND THUNDERSTORMS. TEMPERATURES COULD EVEN APPROACH
80 IN THE HUDSON VALLEY.
AS UPPER LEVEL HEIGHTS FLATTEN OUT MONDAY NIGHT INTO TUESDAY...A FEW
DISTURBANCES MOVING THROUGH IN THE INCREASING WESTERLY FLOW ALOFT
WILL RESULT IN A CONTINUED CHANCE FOR CONVECTION. DUE TO LACK OF
SIGNIFICANT INSTABILITY...ONLY GENERIC NON-SEVERE STORMS ARE
EXPECTED. TUESDAY ALSO LOOKS TO BE A DAY OF TRANSITION IN TERM OF
TEMPERATURES...AS BOTH GFS/ECMWF INDICATING A SIDE-DOOR COLD FRONT
WILL PUSH WESTWARD FROM NEW ENGLAND AS THE PATTERN AMPLIFIES WITH
HIGH PRESSURE NOSING SOUTHWARD INTO MAINE AND THE CANADIAN
MARITIMES. IT LOOKS LIKE THE COLD FRONT WILL APPROACH LATE ON
TUESDAY...SO WILL STILL MAINTAIN RELATIVELY WARM MAX TEMPERATURES.
HOWEVER...ONCE THE FRONT MOVES THROUGH AN ABRUPT WIND SHIFT ALONG
WITH DROPPING TEMPERATURES MAY OCCUR LATE IN THE DAY.
AN UPPER LEVEL RIDGE AXIS IS FORECAST TO MOVE ACROSS THE AREA ON
WEDNESDAY...ALTHOUGH AT THE SURFACE IT WILL BE CLOUDY AND COOL DUE
TO CONTINUED EASTERLY FLOW COMPONENT. WE COULD GET A BREAK IN THE
SHOWER ACTIVITY FOR A SHORT TIME AS WELL...ALTHOUGH THERE COULD
STILL BE LIGHT RAIN OR DRIZZLE POSSIBLE.
MORE WIDESPREAD WET WEATHER COULD DEVELOP THURSDAY INTO FRIDAY...AS
A LONG WAVE TROUGH MOVING EASTWARD MAY STALL OVER OUR REGION AS IT
ENCOUNTERS A STRONG RIDGE ALONG THE EASTERN SEABOARD. COMPLICATING
MATTERS IS ALSO THE POTENTIAL FOR A CUT-OFF LOW TO DEVELOP OVER THE
OHIO VALLEY DEPICTED BY THE ECMWF. THIS COULD RESULT IN SIGNIFICANT
RAINFALL SOMEWHERE IN THE MID ATLANTIC REGION AND NORTHEAST...BUT IS
TOO EARLY TO PINPOINT AT THIS TIME. WILL MAINTAIN CHANCE POPS
THROUGH THE PERIOD TO ACCOUNT FOR UNSETTLED CONDITIONS.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
THE REGION REMAINS WELL ENTRENCHED IN A MARINE TYPE ENVIRONMENT WITH
MVFR/IFR CIGS WITH AN OCCASIONAL DRIZZLE BEING OBSERVED. REGIONAL
RADAR REVEALS A BAND OF SCT-BKN SHOWERS OVER WESTERN NEW YORK THAT
WILL MOVE ACROSS THE TERMINALS DURING THE OVERNIGHT PERIOD. PER
EXPERIMENTAL REFLECTIVITIES FORECASTS...MOST OF THE SHOWERS SHOULD
BE DEPARTING BETWEEN 11-13Z AND HAVE FORECAST THIS WITHIN THE TAFS.
THERE IS A SMALL CHANCE FOR THUNDER BUT CONFIDENCE IS TOO LOW TO
MENTION IN THE FORECAST.
IN THE WAKE OF THE SHOWERS...MAIN FRONT REMAINS UPSTREAM AND WITH
THE DAYTIME HEATING...ADDITIONAL SHOWERS WILL BE POSSIBLE AS WE WILL
PLACE A VCSH IN THE TAFS AT THIS TIME. THE CHANCE FOR SHOWERS WILL
QUICKLY DISSIPATE CLOSE TO SUNSET WITH IMPROVING AVIATION CONDITIONS
INTO THE SATURDAY EVENING HOURS.
WINDS WILL BE SOUTHEAST AROUND 10 KTS WITH SOME OCCASIONAL HIGHER
GUSTS...BECOMING SOUTHWESTERLY SATURDAY MORNING AND INCREASING TO
AROUND 10-15 KT WITH SOME HIGHER GUSTS INTO THE 20 KT RANGE.
OUTLOOK...
SATURDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA...TSRA.
SUNDAY: LOW OPERATIONAL IMPACT.BREEZY NO SIG WX.
SUNDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
MONDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
MONDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
TUESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
TUESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
WEDNESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
&&
.FIRE WEATHER...
A NEARLY STATIONARY WARM FRONT ACROSS THE REGION WILL LIFT
NORTHEASTWARD BY LATE TONIGHT. ON SATURDAY A WEAK COLD FRONT WILL
CROSS THE REGION. THESE FRONTAL BOUNDARIES WILL BE ACCOMPANIED BY
SOME SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL BUILD IN FOR
SUNDAY WITH FAIR AND MILD WEATHER.
FIRE WEATHER CONCERNS THROUGH SATURDAY WILL BE MINIMAL.
&&
.HYDROLOGY...
NO WIDESPREAD HYDROLOGIC PROBLEMS ARE ANTICIPATED DURING THE NEXT
FIVE DAYS.
A NEARLY STATIONARY WARM FRONT ACROSS THE REGION WILL LIFT
NORTHEASTWARD BY LATE TONIGHT. ON SATURDAY A WEAK COLD FRONT WILL
CROSS THE REGION. THESE FRONTAL BOUNDARIES WILL BE ACCOMPANIED BY
SOME SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL BUILD IN FOR
SUNDAY WITH FAIR AND MILD WEATHER.
BASIN AVERAGE RAINFALL FROM THESE FRONTAL BOUNDARIES WILL GENERALLY
BE BETWEEN A QUARTER AND HALF AN INCH THROUGH SATURDAY NIGHT...
ALTHOUGH LOCALIZED AMOUNTS OF AN INCH OR MORE ARE POSSIBLE WHERE
THUNDERSTORMS OCCUR.
WHILE THERE MAY BE SOME MINOR RISES ON RIVERS AND STREAMS...ALL
WATERWAYS ARE EXPECTED TO STAY WITHIN THEIR BANKS...AND NO
FLOODING IS ANTICIPATED AT THIS TIME.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS/GJM
NEAR TERM...FRUGIS/GJM/JPV
SHORT TERM...GJM
LONG TERM...JPV
AVIATION...BGM
FIRE WEATHER...NAS
HYDROLOGY...NAS
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
915 PM EDT SUN MAY 11 2014
.DISCUSSION...
TONIGHT-MON...A POCKET OF DRIER AIR WAS ADVECTING IN FROM THE
EAST/SOUTHEAST AS EVIDENCED BY BLENDED TOTAL PRECIPITABLE WATER
VALUES AROUND ONE INCH OVER THE SOUTHERN PART OF THE STATE. SURFACE
HIGH PRESSURE RIDGE WILL NUDGE JUST A LITTLE TO THE NORTH WHICH WILL
BACK SURFACE WINDS TO THE EAST ON MON. THE PRESSURE GRADIENT WILL
START TO TIGHTEN A BIT TOO AS EASTERLY WAVE MOVES ACROSS THE
SOUTHERN BAHAMAS/CUBA. THEREFORE IT WILL GET ON THE WINDY SIDE
ALONG THE SPACE/TREASURE COAST BEHIND THE SEA BREEZE ON MON.
THE MAIN MOISTENING WITH THE EASTERLY WAVE WILL STAY WELL SOUTH OF
THE AREA ON MON BUT WITH INCREASING EAST FLOW...EXPECT A FEW
ATLANTIC CLOUD LINES TO SET UP. THE NAM/GFS ARE DRY TONIGHT/MON BUT
THE HRRR AND LOCAL WRF INDICATE A FEW SHOWERS LATE TONIGHT ACROSS
THE SOUTH. THEREFORE WILL RETAIN A LESS THAN 20 PERCENT POP THERE
LATE TONIGHT.
THE INCREASING ONSHORE FLOW WILL CAUSE ANY EAST/WEST COAST BOUNDARY
INTERACTION LATE MON TO OCCUR OVER WEST CENTRAL FLORIDA. MOS POPS
ARE BELOW 10 PERCENT...SO OTHER THAN A SLIGHT MORNING COASTAL POP
POSSIBLE IN THE SOUTH...IT LOOKS LIKE A DRY DAY.
FORECAST SOUNDINGS CONTINUE TO SHOW THAT THERE WILL BE SOME CIRRUS
BUT STILL EXPECT PARTLY SUNNY SKIES. LITTLE CHANGE IN MAX TEMPS WITH
MID 80S ALONG THE COAST AND AROUND 90 ACROSS THE INTERIOR.
&&
.AVIATION...
VFR. BREEZY CONDITIONS WILL RETURN BEHIND THE SEA BREEZE ON MON WITH
GUSTS 20-25 KNOTS INDICATED KMLB-KSUA.
&&
.MARINE...
TONIGHT/MON...THERE WILL BE A GRADUAL DETERIORATION OF CONDITIONS
FOR SMALL CRAFT. THE PRESSURE GRADIENT WILL TIGHTEN UP A BIT AND
WINDS WILL BACK TO EASTERLY BY MON. EXERCISE CAUTION CONDITIONS
LOOK LIKELY ON MON IN THE SOUTH. THE CENTRAL ZONES SHOULD BE 10-15
KNOTS EARLY MON BUT 15-17 KNOTS BY LATE AFTERNOON. THE NORTHERN
ZONES LOOK CLOSE TO 10 KNOTS EARLY MON THEN CLOSE TO 15 KNOTS BY
LATE DAY.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
FORECASTS...LASCODY
IMPACT WX...WEITLICH
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
1027 PM EDT SUN MAY 11 2014
.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL PREVAIL INTO THE MIDDLE OF THE WEEK.
A COLD FRONT WILL PUSH THROUGH THE REGION LATER THURSDAY OR
EARLY FRIDAY. COOLER AND DRIER HIGH PRESSURE WILL THEN BUILD INTO
THE AREA THROUGH NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
PER LATE SUNDAY EVENING RADAR TRENDS...APPEARS THAT CONVECTION HAS
ENDED FOR THE NIGHT ACROSS INTERIOR SE GA. ADJUSTED FORECASTS
ACCORDINGLY.
OVERNIGHT...THE RUC13 SUGGESTS THAT ADDITIONAL SHOWERS/THUNDERSTORMS
WILL DEVELOP ACROSS SC COUNTIES LATE TONIGHT...ESPECIALLY CLOSE TO THE
COAST. EVEN ACCOUNTING FOR DIURNAL STABILIZATION...THE 00Z KCHS SOUNDING
REVEALED AMPLE INSTABILITY TO SUPPORT ADDITIONAL CONVECTION.
HOWEVER...A MECHANISM TO INITIATE ADDITIONAL DEEP MOIST CONVECTION
IS LACKING. ALSO...OTHER GUIDANCE INCLUDING THE 00Z NAM DOES NOT
INDICATE ANY NEW CONVECTION OVERNIGHT. THUS...OVERNIGHT POPS
REMAIN BELOW 15 PERCENT WITH NO MENTION OF PRECIPITATION ACROSS
THE FORECAST AREA.
LIGHT WINDS...CLEARING SKIES AND LOW LEVEL MOISTURE WILL SUPPORT
PATCHY STRATUS/FOG OVERNIGHT...ESPECIALLY WHERE RAINFALL OCCURRED SUNDAY
AFTERNOON/EVENING.
TEMPERATURES WILL BOTTOM OUT IN THE UPPER 60S/LOWER 70S MOST
AREAS. A FEW INLAND LOCATIONS COULD DROP INTO THE MIDDLE 60S
TOWARD DAYBREAK.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
MONDAY THROUGH WEDNESDAY...THE PATTERN WILL BE DOMINATED WITH
UPPER RIDGING POSITIONED ACROSS THE SOUTHEAST U.S. WITH THE AREA
LOCATED ALONG THE WESTERN FRINGES OF ATLANTIC HIGH PRESSURE. THIS
SYNOPTIC SETUP WILL FAVOR TYPICAL EARLY SUMMER WEATHER...FEATURING
THE DEVELOPMENT OF DIURNALLY DRIVEN SHOWERS/TSTMS EACH AFTERNOON
AND EVENING...MAINLY ALONG AND AHEAD OF THE SEA BREEZE. GIVEN THE
STRENGTH OF THE UPPER RIDGE...POPS WILL BE CAPPED AT 20-30 PERCENT
AND MAINLY CLUSTERED WEST OF THE I-95 CORRIDOR.
HIGHS WILL GENERALLY TOP OUT IN THE UPPER 80S TO AROUND 90 INLAND
WITH MID 80S JUST INLAND FROM THE BEACHES. OVERNIGHT LOWS WILL DROP
INTO THE MID-UPPER 60S EACH NIGHT...LOCALLY WARMER ALONG THE BEACHES.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
RAIN CHANCES WILL BE ON THE INCREASE WEDNESDAY NIGHT AND THURSDAY AS
DEEP MOISTURE MOVES IN AHEAD OF A COLD FRONT. THERE REMAINS SOME
UNCERTAINTY REGARDING THE EXACT TIMING OF THE FRONTAL PASSAGE AND
THIS WILL IMPACT THE AMOUNT OF INSTABILITY AVAILABLE FOR
THUNDERSTORMS. DEEP LAYER SHEAR APPEARS SUBSTANTIAL ENOUGH TO SUPPORT
SEVERE STORMS SO WILL HAVE TO MONITOR THIS THROUGH THE WEEK. WILL
ALSO KEEP WATCHING A WAVE OF LOW PRESSURE TRACKING ACROSS THE
NORTHERN CARIBBEAN TOWARD THE BAHAMAS WHICH SHOULD REMAIN OFFSHORE
THE SOUTHEAST COAST BUT COULD BRING A BIT MORE MOISTURE TO THE
REGION. DRIER AND UNSEASONABLY COOL AIR LOOKS TO MOVE IN FRIDAY AND
SATURDAY BEFORE ANOTHER COLD FRONT POSSIBLY AFFECTS THE AREA SUNDAY.
SOME INLAND LOCALES COULD SEE MIN TEMPS IN THE UPPER 40S OVER THE
WEEKEND.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS WILL PREVAIL UNTIL LATER TONIGHT. THEN...LOW LEVEL
MOISTURE ENHANCED BY RAINFALL WILL SUPPORT AT LEAST OCCASIONAL
MVFR CONDITIONS AT BOTH TERMINALS...AND BRIEF IFR OR LOWER
CONDITIONS CANNOT BE RULED OUT. VFR CONDITIONS ARE THEN EXPECTED
BY MID-MORNING MONDAY THROUGH THE REMAINDER OF THE 00Z TAF
PERIOD.
EXTENDED AVIATION OUTLOOK...GENERALLY VFR THROUGH WED WITH THE
PROBABILITY OF ANY SIGNIFICANT IMPACTS LESS THAN 30 PERCENT. A COLD
FRONT PUSHING THROUGH THURSDAY OR THURSDAY NIGHT WILL LIKELY BRING
MVFR OR LOWER CIGS/VSBYS DUE TO SHOWERS AND THUNDERSTORMS.
&&
.MARINE...
TRANQUIL CONDITIONS ARE EXPECTED ACROSS COASTAL WATERS OVERNIGHT.
SOUTHERLY WINDS GENERALLY LESS THAN 15 KT AND SEAS 1-3 FT WILL
PREVAIL.
MONDAY THROUGH FRIDAY...NO SIGNIFICANT IMPACTS EXPECTED THROUGH
WED WITH ATLANTIC HIGH PRESSURE DOMINATING. SOUTHERLY WIND REGIME
WILL CONTINUE WITH SPEEDS GENERALLY 15 KT OR LESS WITH SIGNIFICANT
WAVE HEIGHTS 3 FT OR LESS WITHIN 20 NM AND UP TO 4 FT OVER THE GA
20-60 NM ZONE. THERE IS SOME UNCERTAINTY REGARDING THE STRENGTH AND
TIMING OF A COLD FRONT THURSDAY...ALONG WITH A WAVE OF LOW PRESSURE
TRACKING THROUGH THE NORTHERN CARIBBEAN AND BAHAMAS. ANY WAVE SHOULD
REMAIN OFFSHORE GIVEN THE APPROACHING FRONT BUT WINDS AND SEAS COULD
STILL BE HIGHER THAN CURRENTLY FORECAST DEPENDING ON THE STRENGTH OF
THE FRONT.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...SPR
SHORT TERM...ST
LONG TERM...RJB
AVIATION...SPR/ST
MARINE...SPR/ST
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
922 PM EDT SUN MAY 11 2014
.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL PREVAIL INTO THE MIDDLE OF THE WEEK
BEFORE A COLD FRONT LIKELY PUSHES THROUGH THURSDAY OR THURSDAY
NIGHT. UNSEASONABLY COOL HIGH PRESSURE WILL THEN MOVE IN THROUGH
THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
ISOLATED/SCATTERED SHOWERS/THUNDERSTORMS WILL CONTINUE TO DEVELOP
AND DISSIPATE ALONG INTERSECTING MESOSCALE BOUNDARIES ACROSS
INTERIOR SOUTHEAST GEORGIA THIS EVENING...ESPECIALLY ALONG THE I-16
CORRIDOR WELL WEST OF I-95. MLCAPES 1500-2000 J/KG AND DOWNDRAFT
CAPES AROUND 1000 J/KG COULD SUPPORT LOCALLY GUSTY WINDS...WHILE
SLOW STORM PROPAGATION COULD SUPPORT LOCALLY HEAVY RAIN. THEN...
POPS IN THIS AREA FALL BELOW 15 PERCENT BY MIDNIGHT AS BOUNDARIES
PUSH INLAND AND DIURNAL STABILIZATION CONTINUES.
OVERNIGHT...THE RUC13 SUGGESTS THAT ADDITIONAL SHOWERS/THUNDERSTORMS
WILL DEVELOP ACROSS SC COUNTIES...ESPECIALLY CLOSE TO THE
COAST. THE 00Z KCHS SOUNDING REVEALED AMPLE INSTABILITY TO SUPPORT
ADDITIONAL CONVECTION...BUT A MECHANISM TO INITIATE ADDITIONAL
DEEP MOIST CONVECTION IS LACKING. ALSO...OTHER HIGH RESOLUTION
GUIDANCE DOES NOT INDICATE ANY NEW CONVECTION OVERNIGHT.
THUS...OVERNIGHT POPS REMAIN BELOW 15 PERCENT WITH NO MENTION OF
PRECIPITATION ACROSS THE FORECAST AREA.
LIGHT WINDS...CLEARING SKIES AND LOW LEVEL MOISTURE WILL SUPPORT
PATCHY FOG OVERNIGHT...ESPECIALLY WHERE RAINFALL OCCURRED SUNDAY
AFTERNOON/EVENING.
TEMPERATURES WILL BOTTOM OUT IN THE UPPER 60S/LOWER 70S MOST
AREAS. A FEW INLAND LOCATIONS COULD DROP INTO THE MIDDLE 60S
TOWARD DAYBREAK.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
MONDAY THROUGH WEDNESDAY...THE PATTERN WILL BE DOMINATED WITH
UPPER RIDGING POSITIONED ACROSS THE SOUTHEAST U.S. WITH THE AREA
LOCATED ALONG THE WESTERN FRINGES OF ATLANTIC HIGH PRESSURE. THIS
SYNOPTIC SETUP WILL FAVOR TYPICAL EARLY SUMMER WEATHER...FEATURING
THE DEVELOPMENT OF DIURNALLY DRIVEN SHOWERS/TSTMS EACH AFTERNOON
AND EVENING...MAINLY ALONG AND AHEAD OF THE SEA BREEZE. GIVEN THE
STRENGTH OF THE UPPER RIDGE...POPS WILL BE CAPPED AT 20-30 PERCENT
AND MAINLY CLUSTERED WEST OF THE I-95 CORRIDOR.
HIGHS WILL GENERALLY TOP OUT IN THE UPPER 80S TO AROUND 90 INLAND
WITH MID 80S JUST INLAND FROM THE BEACHES. OVERNIGHT LOWS WILL DROP
INTO THE MID-UPPER 60S EACH NIGHT...LOCALLY WARMER ALONG THE BEACHES.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
RAIN CHANCES WILL BE ON THE INCREASE WEDNESDAY NIGHT AND THURSDAY AS
DEEP MOISTURE MOVES IN AHEAD OF A COLD FRONT. THERE REMAINS SOME
UNCERTAINTY REGARDING THE EXACT TIMING OF THE FRONTAL PASSAGE AND
THIS WILL IMPACT THE AMOUNT OF INSTABILITY AVAILABLE FOR
THUNDERSTORMS. DEEP LAYER SHEAR APPEARS SUBSTANTIAL ENOUGH TO SUPPORT
SEVERE STORMS SO WILL HAVE TO MONITOR THIS THROUGH THE WEEK. WILL
ALSO KEEP WATCHING A WAVE OF LOW PRESSURE TRACKING ACROSS THE
NORTHERN CARIBBEAN TOWARD THE BAHAMAS WHICH SHOULD REMAIN OFFSHORE
THE SOUTHEAST COAST BUT COULD BRING A BIT MORE MOISTURE TO THE
REGION. DRIER AND UNSEASONABLY COOL AIR LOOKS TO MOVE IN FRIDAY AND
SATURDAY BEFORE ANOTHER COLD FRONT POSSIBLY AFFECTS THE AREA SUNDAY.
SOME INLAND LOCALES COULD SEE MIN TEMPS IN THE UPPER 40S OVER THE
WEEKEND.
&&
.AVIATION /01Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS WILL PREVAIL UNTIL LATER TONIGHT. THEN...LOW LEVEL
MOISTURE ENHANCED BY RAINFALL WILL SUPPORT AT LEAST OCCASIONAL
MVFR CONDITIONS AT BOTH TERMINALS...AND BRIEF IFR OR LOWER
CONDITIONS CANNOT BE RULED OUT. VFR CONDITIONS ARE THEN EXPECTED
BY MID-MORNING MONDAY THROUGH THE REMAINDER OF THE 00Z TAF
PERIOD.
EXTENDED AVIATION OUTLOOK...GENERALLY VFR THROUGH WED WITH THE
PROBABILITY OF ANY SIGNIFICANT IMPACTS LESS THAN 30 PERCENT. A COLD
FRONT PUSHING THROUGH THURSDAY OR THURSDAY NIGHT WILL LIKELY BRING
MVFR OR LOWER CIGS/VSBYS DUE TO SHOWERS AND THUNDERSTORMS.
&&
.MARINE...
TRANQUIL CONDITIONS ARE EXPECTED ACROSS COASTAL WATERS OVERNIGHT.
SOUTHERLY WINDS GENERALLY LESS THAN 15 KT AND SEAS 1-3 FT WILL
PREVAIL.
MONDAY THROUGH FRIDAY...NO SIGNIFICANT IMPACTS EXPECTED THROUGH
WED WITH ATLANTIC HIGH PRESSURE DOMINATING. SOUTHERLY WIND REGIME
WILL CONTINUE WITH SPEEDS GENERALLY 15 KT OR LESS WITH SIGNIFICANT
WAVE HEIGHTS 3 FT OR LESS WITHIN 20 NM AND UP TO 4 FT OVER THE GA
20-60 NM ZONE. THERE IS SOME UNCERTAINTY REGARDING THE STRENGTH AND
TIMING OF A COLD FRONT THURSDAY...ALONG WITH A WAVE OF LOW PRESSURE
TRACKING THROUGH THE NORTHERN CARIBBEAN AND BAHAMAS. ANY WAVE SHOULD
REMAIN OFFSHORE GIVEN THE APPROACHING FRONT BUT WINDS AND SEAS COULD
STILL BE HIGHER THAN CURRENTLY FORECAST DEPENDING ON THE STRENGTH OF
THE FRONT.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...SPR
SHORT TERM...ST
LONG TERM...RJB
AVIATION...SPR/ST
MARINE...SPR/ST
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
416 PM EDT SAT MAY 10 2014
.SYNOPSIS...
HIGH PRESSURE WILL RIDGE INTO THE FORECAST AREA FROM THE ATLANTIC
TROUGH MONDAY. SOME MOISTURE ASSOCIATED WITH THE REMNANTS OF A
COLD FRONT WILL LINGER. THE MOISTURE AND HEATING MAY HELP SUPPORT
SHOWERS AND THUNDERSTORMS...BUT THE RIDGING SHOULD GENERALLY KEEP
COVERAGE ISOLATED.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
THIS AFTERNOON...MOISTURE ASSOCIATED WITH THE REMNANTS OF A COLD
FRONT...A LITTLE CONVERGENCE INTO A WEAK LEE-SIDE TROUGH...PLUS
HEATING WILL HELP SUPPORT SHOWERS AND THUNDERSTORMS THIS AFTERNOON.
EXPECT COVERAGE WILL REMAIN LIMITED BECAUSE OF A LACK OF DEEP
MOISTURE. THE LATEST LAPS SOUNDINGS INDICATED JUST SHALLOW
MOISTURE. THE LATEST HRRR SUPPORTED SCATTERED COVERAGE. OUR
FORECAST OF CHANCE POPS APPEARS ON TRACK.
LIMITED MOISTURE WILL PROBABLY KEEP THUNDERSTORMS WEAK...BUT SEVERE
THUNDERSTORMS ARE NOT OUT OF THE QUESTION. EARLY AFTERNOON
SURFACE-BASED LI/S WERE NEAR -5. THE KCAE 88D SHOWED UNI-
DIRECTIONAL SHEAR WITH WINDS INCREASING TO 30 KNOTS AT 5000 FEET.
THIS INSTABILITY AND SHEAR PLUS EVAPORATIVE COOLING IN THE MID-
LEVELS POTENTIALLY AIDING DOWNDRAFTS COULD POSSIBLY HELP SUPPORT
NEAR-SEVERE WIND GUSTS IN STRONGER THUNDERSTORMS. WET-BULB ZERO
HEIGHTS NEAR 10000 FEET ALSO SUPPORT HAIL.
TONIGHT...THUNDERSTORMS MAY LINGER THIS EVENING ASSOCIATED
WITH CONVERGENCE INTO THE WEAK LEE-SIDE TROUGH AND BAND OF
MOISTURE FROM THE REMNANTS OF THE FRONT COUPLED WITH WEAK
INSTABILITY. THE HRRR INDICATED SCATTERED COVERAGE IN THE EVENING...
WITH SOME CONCENTRATION IN THE SOUTH PART. AN AVERAGE OF THE GFS
AND NAM MOS SUPPORTED POPS AROUND 20 PERCENT.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
THE GFS AND ESPECIALLY THE NAM SHOW MORE MOISTURE LINGERING MAINLY
IN THE SOUTHEAST SECTION SUNDAY THROUGH MONDAY NIGHT. A WELL-
DEFINED SURFACE FEATURE APPEARS TO BE LACKING. ALOFT...THE MODELS
SHOW RISING H5 HEIGHT. WE USED THE LOWER GUIDANCE POPS. BELIEVE
ANY SHOWERS AND THUNDERSTORMS WILL BE ISOLATED AND MAINLY TIED TO
HEATING. KEPT HIGHS SLIGHTLY HIGHER THAN THE MOS GUIDANCE GIVEN
RECENT VERIFICATION...UPPER RIDGING...AND THE DRY ENVIRONMENTAL
CONDITIONS. USED THE MOS CONSENSUS FOR THE LOW TEMPERATURES.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
MODELS IN GENERAL AGREEMENT ON TUESDAY WITH BERMUDA HIGH IN PLACE
FOR THE SE US AND AN UPPER TROUGH OVER THE MID PART OF THE COUNTRY.
THE PROGRESSION EASTWARD OF THE UPPER TROUGH HAS SLOWED IN LATEST
MODEL RUNS. WHILE THE HIGH OFF THE COAST WILL DOMINATE INTO MID
WEEK...INCREASING MOISTURE AND TEMPERATURES WILL RESULT IN A CHANCE
OF A FEW AFTERNOON THUNDERSTORMS TUESDAY. THE DIURNAL ACTIVITY WILL
DIMINISH OVERNIGHT AND THEN THE CHANCE OF AFTERNOON THUNDERSTORMS
INCREASES WEDNESDAY. AS THE NEXT SYSTEM SLOWLY APPROACHES THE AREA
AND MOVES THROUGH ON THURSDAY EXPECT THE CHANCE OF RAIN TO CONTINUE
AND ATTM EXPECT THE HIGHEST CHANCE TO BE THURSDAY
AFTERNOON/EVENING. WILL HAVE TO CONTINUE TO WATCH THE TIMING AND
PROGRESSION OF THE UPPER TROUGH. TEMPERATURES AHEAD OF THE NEXT
SYSTEM SHOULD BE ABOVE NORMAL IN THE UPPER 80S TUESDAY AND
WEDNESDAY AND THEN AS CLOUDS AND PRECIPITATION MOVE IN...HIGHS
WILL BE SOMEWHAT COOLER THE REMAINDER OF THE WEEK IN THE UPPER 70S
TO AROUND 80.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
MOISTURE ASSOCIATED WITH THE REMNANTS OF A COLD FONT COMBINED WITH
HEATING AND A LITTLE CONVERGENCE INTO A WEAK LEE-SIDE TROUGH HAS
HELPED SUPPORT SCATTERED SHOWERS AND THUNDERSTORMS. BELIEVE
COVERAGE WILL REMAIN SCATTERED BECAUSE OF LIMITED MOISTURE.
LINGERING THUNDERSTORMS WILL LIKELY DISSIPATE LATER THIS EVENING
WITH THE LOSS OF HEATING. LIGHT WIND...SOME LOW-LEVEL MOISTURE
AND NOCTURNAL COOLING MAY HELP CAUSE FOG LATE TONIGHT. SOME OF THE
NAM AND GFS MOS INDICATE MVFR OR IFR FOG WITH THE GREATER
RESTRICTIONS AT THE RIVER VALLEY TERMINALS OF AGS AND OGB. HEATING
AND MIXING SHOULD DISSIPATE ANY FOG BY 14Z.
.EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED
THROUGH WEDNESDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
203 PM EDT SAT MAY 10 2014
.SYNOPSIS...
HIGH PRESSURE WILL RIDGE INTO THE FORECAST AREA FROM THE ATLANTIC
TROUGH MONDAY. SOME MOISTURE ASSOCIATED WITH THE REMNANTS OF A
COLD FRONT WILL LINGER. THE MOISTURE AND HEATING MAY HELP SUPPORT
SHOWERS AND THUNDERSTORMS...BUT THE RIDGING SHOULD GENERALLY KEEP
COVERAGE ISOLATED.
&&
.NEAR TERM /THROUGH TONIGHT/...
THIS AFTERNOON...MOISTURE ASSOCIATED WITH THE REMNANTS OF A COLD
FRONT...A LITTLE CONVERGENCE INTO A WEAK LEE-SIDE TROUGH...PLUS
HEATING WILL HELP SUPPORT SHOWERS AND THUNDERSTORMS THIS AFTERNOON.
EXPECT COVERAGE WILL REMAIN LIMITED BECAUSE OF A LACK OF DEEP
MOISTURE. THE LATEST LAPS SOUNDINGS INDICATED JUST SHALLOW
MOISTURE. THE LATEST HRRR SUPPORTED SCATTERED COVERAGE. OUR
FORECAST OF CHANCE POPS APPEARS ON TRACK.
LIMITED MOISTURE WILL PROBABLY KEEP THUNDERSTORMS WEAK...BUT SEVERE
THUNDERSTORMS ARE NOT OUT OF THE QUESTION. EARLY AFTERNOON
SURFACE-BASED LI/S WERE NEAR -5. THE KCAE 88D SHOWED UNI-
DIRECTIONAL SHEAR WITH WINDS INCREASING TO 30 KNOTS AT 5000 FEET.
THIS INSTABILITY AND SHEAR PLUS EVAPORATIVE COOLING IN THE MID-
LEVELS POTENTIALLY AIDING DOWNDRAFTS COULD POSSIBLY HELP SUPPORT
NEAR-SEVERE WIND GUSTS IN STRONGER THUNDERSTORMS. WET-BULB ZERO
HEIGHTS NEAR 10000 FEET ALSO SUPPORT HAIL.
TONIGHT...THUNDERSTORMS MAY LINGER THIS EVENING ASSOCIATED
WITH CONVERGENCE INTO THE WEAK LEE-SIDE TROUGH AND BAND OF
MOISTURE FROM THE REMNANTS OF THE FRONT COUPLED WITH WEAK
INSTABILITY. THE HRRR INDICATED SCATTERED COVERAGE IN THE EVENING...
WITH SOME CONCENTRATION IN THE SOUTH PART. AN AVERAGE OF THE GFS
AND NAM MOS SUPPORTED POPS AROUND 20 PERCENT.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
THE GFS AND ESPECIALLY THE NAM SHOW MORE MOISTURE LINGERING MAINLY
IN THE SOUTHEAST SECTION SUNDAY THROUGH MONDAY NIGHT. A WELL-
DEFINED SURFACE FEATURE APPEARS TO BE LACKING. ALOFT...THE MODELS
SHOW RISING H5 HEIGHT. WE USED THE LOWER GUIDANCE POPS. BELIEVE
ANY SHOWERS AND THUNDERSTORMS WILL BE ISOLATED AND MAINLY TIED TO
HEATING. KEPT HIGHS SLIGHTLY HIGHER THAN THE MOS GUIDANCE GIVEN
RECENT VERIFICATION...UPPER RIDGING...AND THE DRY ENVIRONMENTAL
CONDITIONS. USED THE MOS CONSENSUS FOR THE LOW TEMPERATURES.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
MODELS IN GENERAL AGREEMENT ON TUESDAY WITH BERMUDA HIGH IN PLACE
FOR THE SE US AND AN UPPER TROUGH OVER THE MID PART OF THE COUNTRY.
THE PROGRESSION EASTWARD OF THE UPPER TROUGH HAS SLOWED IN LATEST
MODEL RUNS. WHILE THE HIGH OFF THE COAST WILL DOMINATE INTO MID
WEEK...INCREASING MOISTURE AND TEMPERATURES WILL RESULT IN A CHANCE
OF A FEW AFTERNOON THUNDERSTORMS TUESDAY. THE DIURNAL ACTIVITY WILL
DIMINISH OVERNIGHT AND THEN THE CHANCE OF AFTERNOON THUNDERSTORMS
INCREASES WEDNESDAY. AS THE NEXT SYSTEM SLOWLY APPROACHES THE AREA
AND MOVES THROUGH ON THURSDAY EXPECT THE CHANCE OF RAIN TO CONTINUE
AND ATTM EXPECT THE HIGHEST CHANCE TO BE THURSDAY
AFTERNOON/EVENING. WILL HAVE TO CONTINUE TO WATCH THE TIMING AND
PROGRESSION OF THE UPPER TROUGH. TEMPERATURES AHEAD OF THE NEXT
SYSTEM SHOULD BE ABOVE NORMAL IN THE UPPER 80S TUESDAY AND
WEDNESDAY AND THEN AS CLOUDS AND PRECIPITATION MOVE IN...HIGHS
WILL BE SOMEWHAT COOLER THE REMAINDER OF THE WEEK IN THE UPPER 70S
TO AROUND 80.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
SOME MOISTURE ASSOCIATED WITH THE REMNANTS OF A COLD FRONT WILL
BE IN THE FORECAST AREA THIS AFTERNOON AND EVENING. THE MOISTURE
COMBINED WITH A LITTLE CONVERGENCE INTO A WEAK LEE-SIDE TROUGH
WILL LIKELY SUPPORT THUNDERSTORMS. HOWEVER...THE MOISTURE WILL
REMAIN LIMITED AND THE FORCING WILL BE WEAK. EXPECT SCATTERED
COVERAGE. THE CHANCE OF THUNDERSTORMS IS TOO LOW TO INCLUDE IN THE
TERMINAL FORECASTS AT THIS TIME. LIGHT WIND...SOME LOW-LEVEL
MOISTURE AND NOCTURNAL COOLING MAY HELP CAUSE FOG LATE TONIGHT.
SOME OF THE NAM AND GFS MOS INDICATE MVFR OR IFR FOG WITH THE
GREATER RESTRICTIONS AT THE RIVER VALLEY TERMINALS OF AGS AND OGB.
.EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED
THROUGH WEDNESDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
113 PM EDT SAT MAY 10 2014
.SYNOPSIS...
HIGH PRESSURE WILL RIDGE INTO THE FORECAST AREA FROM THE ATLANTIC
TROUGH MONDAY. SOME MOISTURE ASSOCIATED WITH THE REMNANTS OF A
COLD FRONT WILL LINGER. THE MOISTURE AND HEATING MAY HELP SUPPORT
SHOWERS AND THUNDERSTORMS...BUT THE RIDGING SHOULD GENERALLY KEEP
COVERAGE ISOLATED.
&&
.NEAR TERM /THROUGH TONIGHT/...
THIS AFTERNOON...MOISTURE ASSOCIATED WITH THE REMNANTS OF A COLD
FRONT...A LITTLE CONVERGENCE INTO A WEAK LEE-SIDE TROUGH...PLUS
HEATING WILL HELP SUPPORT SHOWERS AND THUNDERSTORMS THIS AFTERNOON.
EXPECT COVERAGE WILL REMAIN LIMITED BECAUSE OF A LACK OF DEEP
MOISTURE. THE LATEST LAPS SOUNDINGS INDICATED JUST SHALLOW
MOISTURE. THE LATEST HRRR SUPPORTED SCATTERED COVERAGE. OUR
FORECAST OF CHANCE POPS APPEARS ON TRACK.
LIMITED MOISTURE WILL PROBABLY KEEP THUNDERSTORMS WEAK...BUT SEVERE
THUNDERSTORMS ARE NOT OUT OF THE QUESTION. EARLY AFTERNOON
SURFACE-BASED LI/S WERE NEAR -5. THE KCAE 88D SHOWED UNI-
DIRECTIONAL SHEAR WITH WINDS INCREASING TO 30 KNOTS AT 5000 FEET.
THIS INSTABILITY AND SHEAR PLUS EVAPORATIVE COOLING IN THE MID-
LEVELS POTENTIALLY AIDING DOWNDRAFTS COULD POSSIBLY HELP SUPPORT
NEAR-SEVERE WIND GUSTS IN STRONGER THUNDERSTORMS. WET-BULB ZERO
HEIGHTS NEAR 10000 FEET ALSO SUPPORT HAIL.
TONIGHT...THUNDERSTORMS MAY LINGER THIS EVENING ASSOCIATED
WITH CONVERGENCE INTO THE WEAK LEE-SIDE TROUGH AND BAND OF
MOISTURE FROM THE REMNANTS OF THE FRONT COUPLED WITH WEAK
INSTABILITY. THE HRRR INDICATED SCATTERED COVERAGE IN THE EVENING...
WITH SOME CONCENTRATION IN THE SOUTH PART. AN AVERAGE OF THE GFS
AND NAM MOS SUPPORTED POPS AROUND 20 PERCENT.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
THE GFS AND ESPECIALLY THE NAM SHOW MORE MOISTURE LINGERING MAINLY
IN THE SOUTHEAST SECTION SUNDAY THROUGH MONDAY NIGHT. A WELL-
DEFINED SURFACE FEATURE APPEARS TO BE LACKING. ALOFT...THE MODELS
SHOW RISING H5 HEIGHT. WE USED THE LOWER GUIDANCE POPS. BELIEVE
ANY SHOWERS AND THUNDERSTORMS WILL BE ISOLATED AND MAINLY TIED TO
HEATING. KEPT HIGHS SLIGHTLY HIGHER THAN THE MOS GUIDANCE GIVEN
RECENT VERIFICATION...UPPER RIDGING...AND THE DRY ENVIRONMENTAL
CONDITIONS. USED THE MOS CONSENSUS FOR THE LOW TEMPERATURES.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
MODELS IN GENERAL AGREEMENT ON TUESDAY WITH BERMUDA HIGH IN PLACE
FOR THE SE US AND AN UPPER TROUGH OVER THE MID PART OF THE COUNTRY.
THE PROGRESSION EASTWARD OF THE UPPER TROUGH HAS SLOWED IN LATEST
MODEL RUNS. WHILE THE HIGH OFF THE COAST WILL DOMINATE INTO MID
WEEK...INCREASING MOISTURE AND TEMPERATURES WILL RESULT IN A CHANCE
OF A FEW AFTERNOON THUNDERSTORMS TUESDAY. THE DIURNAL ACTIVITY WILL
DIMINISH OVERNIGHT AND THEN THE CHANCE OF AFTERNOON THUNDERSTORMS
INCREASES WEDNESDAY. AS THE NEXT SYSTEM SLOWLY APPROACHES THE AREA
AND MOVES THROUGH ON THURSDAY EXPECT THE CHANCE OF RAIN TO CONTINUE
AND ATTM EXPECT THE HIGHEST CHANCE TO BE THURSDAY
AFTERNOON/EVENING. WILL HAVE TO CONTINUE TO WATCH THE TIMING AND
PROGRESSION OF THE UPPER TROUGH. TEMPERATURES AHEAD OF THE NEXT
SYSTEM SHOULD BE ABOVE NORMAL IN THE UPPER 80S TUESDAY AND
WEDNESDAY AND THEN AS CLOUDS AND PRECIPITATION MOVE IN...HIGHS
WILL BE SOMEWHAT COOLER THE REMAINDER OF THE WEEK IN THE UPPER 70S
TO AROUND 80.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
SOME MOISTURE ASSOCIATED WITH THE REMNANTS OF A COLD FRONT WILL
BE IN THE FORECAST AREA THIS AFTERNOON AND EVENING. THE MOISTURE
COMBINED WITH A LITTLE CONVERGENCE INTO A WEAK LEE-SIDE TROUGH
WILL LIKELY SUPPORT THUNDERSTORMS. HOWEVER...THE MOISTURE WILL
REMAIN LIMITED AND THE FORCING WILL BE WEAK. EXPECT SCATTERED
COVERAGE. THE CHANCE OF THUNDERSTORMS IS TOO LOW TO INCLUDE IN THE
TERMINAL FORECASTS AT THIS TIME. LIGHT WIND...SOME LOW-LEVEL
MOISTURE AND NOCTURNAL COOLING MAY HELP CAUSE FOG LATE TONIGHT.
SOME OF THE NAM AND GFS MOS INDICATE MVFR OR IFR FOG WITH THE
GREATER RESTRICTIONS AT THE RIVER VALLEY TERMINALS OF AGS AND OGB.
.EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED
THROUGH WEDNESDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1115 AM EDT SAT MAY 10 2014
.SYNOPSIS...
MOISTURE ASSOCIATED WITH THE REMNANTS OF A COLD FRONT WILL SHIFT
EAST OF THE FORECAST AREA TONIGHT. HIGH PRESSURE EXTENDING INTO
THE FORECAST AREA FROM THE ATLANTIC WILL DOMINATE SUNDAY THROUGH
TUESDAY. MOISTURE WILL INCREASE WEDNESDAY AHEAD OF A FRONTAL
SYSTEM.
&&
.NEAR TERM /THROUGH TONIGHT/...
THIS AFTERNOON...MOISTURE ASSOCIATED WITH THE REMNANTS OF A COLD
FRONT...A LITTLE CONVERGENCE INTO A WEAK LEE-SIDE TROUGH...PLUS
HEATING WILL HELP SUPPORT SHOWERS AND THUNDERSTORMS THIS AFTERNOON.
EXPECT COVERAGE WILL REMAIN LIMITED BECAUSE OF A LACK OF DEEP
MOISTURE. THE LATEST LAPS SOUNDINGS INDICATED JUST SHALLOW
MOISTURE. THE LATEST HRRR SUPPORTED SCATTERED COVERAGE. OUR
FORECAST OF CHANCE POPS APPEARS ON TRACK.
LIMITED MOISTURE WILL PROBABLY KEEP THUNDERSTORMS WEAK...BUT SEVERE
THUNDERSTORMS ARE NOT OUT OF THE QUESTION. LATE MORNING SURFACE-
BASED LI/S WERE NEAR -4. EXPECT AFTERNOON VALUES AROUND -5. THE
KCAE 88D SHOWED UNI-DIRECTIONAL SHEAR WITH WINDS INCREASING TO
30 KNOTS AT 5000 FEET. THIS INSTABILITY AND SHEAR PLUS EVAPORATIVE
COOLING IN THE MID-LEVELS POTENTIALLY AIDING DOWNDRAFTS COULD
POSSIBLY HELP SUPPORT NEAR-SEVERE WIND GUSTS IN STRONGER
THUNDERSTORMS. WET-BULB ZERO HEIGHTS NEAR 10000 FEET ALSO SUPPORT
HAIL.
TONIGHT...THUNDERSTORMS MAY LINGER THIS EVENING ASSOCIATED
WITH CONVERGENCE INTO THE WEAK LEE-SIDE TROUGH AND BAND OF
MOISTURE FROM THE REMNANTS OF THE FRONT COUPLED WITH WEAK
INSTABILITY. THE GUIDANCE CONSENSUS SUPPORTS POPS AROUND 20
PERCENT.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
THE MODELS INDICATE RISING HEIGHTS SUNDAY INTO SUNDAY NIGHT. THE
SURFACE SUBTROPICAL ATLANTIC RIDGE WILL SLOWLY BUILD WESTWARD INTO
THE SOUTHEASTERN STATES. ENSEMBLE POPS REMAIN BELOW NORMAL...
THOUGH CANNOT RULE OUT ISOLATED THUNDERSTORMS MAINLY ASSOCIATED
WITH HEATING MONDAY AND TUESDAY. KEPT HIGHS SLIGHTLY HIGHER THAN
MOS GUIDANCE GIVEN RECENT VERIFICATION...UPPER RIDGING...AND THE
DRY ENVIRONMENTAL CONDITIONS. THE MOS CONSENSUS WAS USED FOR
OVERNIGHT LOWS.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
MODELS ARE IN RELATIVELY GOOD AGREEMENT THROUGH TUESDAY...THEN
BEGIN TO DIFFER LATER IN THE WEEK. THE GFS MOVES THE UPPER LEVEL
TROF AND SFC CDFNT OUT EARLIER WHILE THE ECMWF IS SLOWER BY 24HRS.
AS A RESULT CHANCES OF RAIN AND TEMPS ARE DIFFERENT. FORECAST
LEANS TOWARD THE SLOWER ECMWF FOR THE END OF NEXT WEEK.
SHOULD SEE MAINLY DRY CONDITIONS THROUGH TUESDAY AS THE UPPER
RIDGE BUILDS ACROSS THE REGION AND SURFACE HIGH PRESSURE OVER THE
WESTERN ATLANTIC RIDGES INTO THE SOUTHEASTERN STATES. THE NEXT
CHANCE OF PRECIP ARRIVES MID-WEEK. MAX TEMPERATURES WILL BE AROUND
90 TUESDAY WITH UPPER 80S WEDNESDAY COOLING INTO THE UPPER 70S TO
LOWER 80S THURSDAY AND FRIDAY. OVERNIGHT LOWS WILL BE IN THE 60S
THROUGH THURSDAY AND IN THE 50S FRIDAY.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
SOME MOISTURE ASSOCIATED WITH THE REMNANTS OF A COLD FRONT WILL
BE IN THE FORECAST AREA THIS AFTERNOON AND EVENING. THE MOISTURE
COMBINED WITH A LITTLE CONVERGENCE INTO A WEAK LEE-SIDE TROUGH
WILL LIKELY SUPPORT THUNDERSTORMS. HOWEVER...THE MOISTURE WILL
REMAIN LIMITED AND THE FORCING WILL BE WEAK. EXPECT SCATTERED
COVERAGE. THE CHANCE OF THUNDERSTORMS IS TOO LOW TO INCLUDE IN THE
TERMINAL FORECASTS AT THIS TIME. LIGHT WIND...SOME LOW-LEVEL
MOISTURE AND NOCTURNAL COOLING MAY HELP CAUSE FOG LATE TONIGHT.
SOME OF THE NAM AND GFS MOS INDICATE MVFR OR IFR FOG WITH THE
GREATER RESTRICTIONS AT THE RIVER VALLEY TERMINALS OF AGS AND OGB.
.EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED
THROUGH WEDNESDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS CHICAGO/ROMEOVILLE IL
932 PM CDT SUN MAY 11 2014
.DISCUSSION...
930 PM CDT
STORMS ACROSS THE FAR SOUTHERN FORECAST AREA HAVE SHOWN A
CONSISTENT WEAKENING TREND IN THE PAST HOUR. STILL SOME
CONVERGENCE ON THE OUTFLOW BOUNDARY WITH WARM/MOIST ADVECTION
850-925MB ADVECTION INTO THIS AREA. SO SOME REGENERATION OF
STORMS MAY CONTINUE AS RADAR TRENDS HAVE INDICATED IN MCCLEAN
COUNTY...ALTHOUGH THE REFLECTIVITY TREND IS GENERALLY DOWNWARDS.
SO THE FLOODING THREAT IS GRADUALLY DIMINISHING.
TEMPORARY SUPPRESSION AND MID-LEVEL DRYING BEHIND MCS SHOULD KEEP
MUCH OF THE FORECAST AREA QUIET THROUGH 3 AM OR SO. WIDESPREAD
CONVECTION ACROSS WESTERN IOWA SHOULD EVOLVE EAST NORTHEAST WITH
POSSIBLE SCATTERED DEVELOPMENT AHEAD OF THIS ON THE LOW-LEVEL JET
AND JUST INCREASING UPPER/MID-LEVEL FORCING. THIS IS MOST FAVORED
IN NORTH CENTRAL ILLINOIS...INCLUDING TOWARD ROCKFORD. THIS WOULD
HAVE A SMALL SEVERE WEATHER CHANCE. OVERALL BUILDING HEIGHTS
SHOULD LIMIT A WELL-DEVELOPED MCS FROM THE WEST MOVING INTO THE
FORECAST AREA.
MTF
&&
.PREV DISCUSSION...
300 PM CDT
FORECAST CONCERNS ARE MAINLY ON THE IMMEDIATE SEVERE WEATHER
CHANCES THROUGH EARLY/MID EVENING. ALSO FOCUS ON THE SEVERE
WEATHER POTENTIAL ON MONDAY...PRIMARILY MONDAY LATE AFTERNOON INTO
THE NIGHTTIME PERIOD.
OVERNIGHT INTO MONDAY MORNING...
STRONG UPPER JET WILL PROPAGATE AROUND THE UPPER TROUGH LATE
TONIGHT INTO THE MORNING ON MONDAY AND WITH THAT LEAD TO FURTHER
AMPLIFYING OF THE UPSTREAM RIDGE...INCLUDING BUILDING HEIGHTS
ACROSS MUCH OF THE FORECAST AREA. MUCH OF THE FORCING FOR
RAIN/STORMS IN THIS PERIOD WOULD BE FOCUSED TO THE WEST AND NORTH
IN SUCH A PATTERN. THE STRONG LOW-LEVEL JET WILL AT LEAST IN PART
BE OVER THE AREA...HOWEVER THE NOSE OF IT WILL BE POINTED FURTHER
NORTH. CONVECTIVE CHANCES LOOK MINIMAL AND MAINLY THE NORTHWEST
FORECAST AREA TOWARD ROCKFORD. CHANCES MAY BE INCREASED SOMEWHAT
IF ANY ORGANIZED CONVECTION FROM THE CENTRAL PLAINS WERE TO
PROPAGATE EASTWARD INTO NORTHERN IL...BUT THE GRADUALLY MORE
MERIDIONAL FLOW AND ORIENTATION OF FORECAST CORFIDI VECTORS WOULD
PUSH MUCH OF THE CONVECTION NORTH OF THE AREA. LOW TEMPS WILL BE
BALMY WITH CONTINUED SOUTHERLY FLOW AND HIGH DEW POINT AIR...WITH
SOME PLACES EXPERIENCING SOME WARMING OF TEMPS LATER THIS
EVENING...ESPECIALLY THOSE IMPACTED BY EARLY EVE CONVECTION AND
THOSE COMMUNITIES NEAR THE LAKE SHORE THAT HAD AFTERNOON/EVE
COOLING.
MONDAY AFTERNOON THROUGH TUESDAY...
THE UPPER TROUGH WILL CONTINUE TO AMPLIFY AS THE UPPER JET TO ITS
FRONT AND BACK INTENSITY. A WARM AND MUGGY DAY IS ANTICIPATED
MONDAY. CONVECTIVE INHIBITION ON MONDAY AFTERNOON DOES LOOK TO BE
OVERCOME BUT A FOCUS IS NOT OVERLY EVIDENT IN OUR FORECAST AREA.
GRADUALLY MORE CONVERGENCE AND INCREASING DEEP LAYER MOISTURE AND
UPWARD MOTION IS FORECAST TO MOVE EASTWARD ACROSS MAINLY NORTH
CENTRAL ILLINOIS LATE IN THE DAY INTO EARLY EVE AND EASE ITS WAY
EASTWARD THROUGH THE REMAINDER OF THE NIGHT. THIS LOOKS LIKE A
PERIOD OF STORMS MOVING NORTHEAST WITHIN THE DEEP MOIST PLUME.
THE SEVERE POTENTIAL WOULD SEEM MOST FAVORED WITH THE INITIAL
CONVECTION IN THE LATE AFTERNOON/EVE AND THEN A GENERAL WANING
LATER INTO THE NIGHT. LOCALLY HEAVY RAINFALL WILL BE PROBABLE IN
SOME OF THESE STORMS AS THE PWATS ARE FORECAST TO BE AROUND 1.50
INCHES AND DEEP MOISTURE CONVERGENCE WILL BE ORIENTED PARALLEL TO
THE UPPER FLOW. THIS PLUME WILL SHIFT EASTWARD THROUGH TUESDAY
MORNING AND LIKELY POPS CERTAINLY SEEM JUSTIFIED TUESDAY MORNING. IF
THE FRONT IS SLOW ENOUGH SOME AFTERNOON ENHANCEMENT OF A FEW STORMS
COULD HAPPEN IN THE EAST...BUT THIS SEEMS MOST FAVORED EAST OF THE
FORECAST AREA AT THIS TIME.
THE COLD AIR ADVECTION WITH THE COLD FRONT...ALONG WITH POTENTIALLY
SOME ANAFRONTAL SHOWERS...WILL LIKELY LEAD TO FALLING TEMPS IN SOME
PLACES AT LEAST AT TIMES ON TUESDAY.
WEDNESDAY AND BEYOND...
LITTLE CHANGES MADE TO THIS PART OF THE FORECAST DUE TO ONGOING
HIGHER IMPACT WEATHER. LARGE MODEL DIFFERENCES EXIST IN THE WED-THU
TIME FRAME...WITH THE 12Z EC COMING IN SLOWER AND MORE AGGRESSIVE
WITH A LOW RIDING UP THE BAROCLINIC ZONE TO OUR EAST. THIS PROVIDES
WIDESPREAD SHOWERS WEDNESDAY AFTERNOON THROUGH EARLY THURSDAY AND
PARTICULARY COOL TEMPS. WITH AN EC/GFS/GOING FORECAST BLEND THIS
PROVIDES A FEW PERIODS OF CHANCE POPS.
TEMPS TO LOOK TO BE BELOW NORMAL NO MATTER WHICH MODEL VERIFIES IN
THE WED-FRI TIME FRAME. IF CONDITIONS CLEAR AND SURFACE RIDGING
MOVES OVER...POSSIBLY THU NIGHT...THERE PROBABLY WILL BE A CONCERN
FOR FROST.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* SHRA/TSRA THROUGH MID EVENING.
* WIND DIRECTIONS THIS EVENING.
* POSSIBLE MVFR CIGS MONDAY MORNING.
* STRONG/GUSTY SOUTHERLY WINDS MONDAY.
* POSSIBLE TSRA LATE MONDAY AFTERNOON/MONDAY EVENING. CMS
//DISCUSSION...UPDATED 00Z...
TSRA HAS CONTINUED TO CONSOLIDATE AND MOVE EAST. ADDITIONAL SHRA
WITH AN OCCASIONAL LIGHTNING STRIKE WILL CONTINUE FOR THE NEXT
HOUR OR TWO. THE BULK OF THIS ACTIVITY IS EXPECTED TO BE EAST OR
SOUTHEAST OF THE CHICAGO AREA TERMINALS BY 02Z-03Z AND HAVE
MAINTAINED SIMILAR TIMING/TRENDS FROM THE PREVIOUS FORECAST.
ANOTHER LINE OF TSRA OVER THE PLAINS WILL NEED TO BE MONITORED AS
IT MOVES EAST OVERNIGHT. CONFIDENCE IS LOW REGARDING HOW FAR EAST
THIS WILL MOVE BEFORE DISSIPATING. SOME OF THE SHORT TERM GUIDANCE
WOULD SUGGEST THAT THIS WILL MAKE IT INTO THE RFD AREA BY DAYBREAK.
INCLUDED A VCSH MENTION THERE BUT FURTHER EAST...MAINTAINED DRY
FORECAST AND TRENDS WILL NEED TO BE MONITORED THROUGH THE NIGHT.
LOW CONFIDENCE CONTINUES FOR PRECIP CHANCES THROUGH SUNSET MONDAY.
WHILE MUCH OF MONDAY LOOKS DRY...ITS POSSIBLE THAT ISOLATED TSRA
MAY DEVELOP ACROSS PARTS OF NORTHERN IL...POSSIBLY REMAINING NORTH
OF THE TERMINALS.
WITH THE LOW LEVELS NOW SATURATED...AS LOW LEVEL MOISTURE
INCREASES...THERE IS A POTENTIAL FOR LOW MVFR CIGS TO DEVELOP
OVERNIGHT AND PERSIST INTO THE MID MORNING HOURS. CONFIDENCE IS
NOT HIGH AND MAINTAINED SCATTERED MENTION FOR NOW.
WINDS WILL SETTLE BACK TO SOUTHEAST AROUND 10KTS THIS EVENING THEN
TURN MORE SOUTHERLY OVERNIGHT WITH THE POTENTIAL FOR SOME GUSTS
INTO THE MID TEEN RANGE. WIND SPEEDS/GUSTS WILL THEN STEADILY
INCREASE THROUGH THE MORNING WITH GUSTS INTO THE MID TO UPPER 20
KT RANGE FOR THE AFTERNOON.
LOW LEVEL WINDS NOW APPEAR LOW ENOUGH OVERNIGHT INTO MONDAY
MORNING THAT LOW LEVEL WIND SHEAR CRITERIA WILL NOT BE MET AND
REMOVED IT FROM THIS FORECAST. CMS
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* HIGH FOR SHRA/TSRA EARLY THIS EVENING.
* LOW FOR WIND DIRECTIONS THIS EVENING...MEDIUM FOR WINDS FOR THE
REST OF THE PERIOD.
* LOW FOR MVFR CIGS OVERNIGHT/MONDAY MORNING.
* LOW FOR TSRA LATE MONDAY AFTERNOON/MONDAY NIGHT. CMS
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
* TUESDAY...TSRA LIKELY IN THE MORNING.
* WEDNESDAY...CHANCE OF SHRA.
* THURSDAY...CHANCE OF SHRA.
* FRIDAY...SLIGHT CHANCE OF SHRA.
* SATURDAY...DRY/VFR.
&&
.MARINE...
242 PM...LOW PRESSURE OVER KANSAS WILL MOVE NORTHEAST TO LAKE
SUPERIOR TUESDAY MORNING. AS IT DOES...A WARM FRONT EXTENDING EAST
FROM THE LOW WILL MOVE NORTH ACROSS THE LAKE TONIGHT THROUGH
MONDAY NIGHT...SHIFTING EASTERLY WINDS SOUTHERLY. LOW LEVEL
MOISTURE WILL ALSO BE INCREASING AND AS IT SPREADS ACROSS THE
COOLER LAKE...AREAS OF FOG ARE POSSIBLE AND SOME OF THE FOG MAY
BECOME DENSE. CURRENT WIND SPEEDS ARE FAIRLY LIGHT IN THE 5-15 KT
RANGE AND WILL INCREASE INTO THE 15-25KT RANGE AND REMAIN THERE
UNTIL A COLD FRONT MOVES ACROSS THE LAKE TUESDAY MORNING. THERE IS
A POTENTIAL FOR WINDS TO BE A BIT STRONGER ON MONDAY...ESPECIALLY
WITH THE EASTERLY FLOW NORTH OF THE WARM FRONT ACROSS NORTHERN
LAKE MICHIGAN. THERE REMAINS UNCERTAINTY REGARDING THE POTENTIAL
FOR STRONG NORTHERLY WINDS WEDNESDAY NIGHT INTO THURSDAY AS LOW
PRESSURE DEEPENS MOVING NORTH ACROSS THE GREAT LAKES REGION. THIS
TIME PERIOD WILL NEED TO BE MONITORED FOR HIGHER NORTHERLY WIND
SPEEDS. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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[top]
Area Forecast Discussion
National Weather Service Lincoln IL
931 PM CDT Sun May 11 2014
.DISCUSSION...
ISSUED 927 PM CDT Sun May 11 2014
The rest of WW #144 will be let go at 10 pm CDT. Most of the
stronger storms have shifted off to our east with some lingering
showers over north central McLean county. Large bow echo over
western Iowa tracking east northeast at 45 to 50 mph. Latest
HRRR model suggest what is left of the complex may get into
western IL just before 12z. Will continue to keep low chance
POPs across the north with the remainder of the area expecting
to see dry conditions. Overall, the grids are in good shape.
Will update the ZFP once our watch expires at 10 pm.
Smith
&&
.AVIATION...
ISSUED 649 PM CDT Sun May 11 2014
VFR conditions expected across the central Illinois terminals
through the 00Z TAF valid time. A warm front has lifted north of
the area today, associated with a few showers/storms. However, now
mainly dry conditions are anticipated until the trailing cold
front associated with the same storm system pushes into the area
Monday night. While this dry period should last across most of the
area until after 00Z Tuesday, VFR low/mid cloud cigs will last
for much of the next 24 hours.
Gusty southerly winds will fall off this evening with the loss of
diurnal heating/mixing. This, and an approaching low level jet,
will allow LLWS to develop later tonight. The LLWS will end as
deeper mixing and gustiness returns Monday morning.
Bak
&&
.PREV DISCUSSION...
ISSUED 248 PM CDT Sun May 11 2014
Air mass destabilizing quickly across central and southeast
Illinois early this afternoon. 18Z upper air sounding from our
office showing CAPE of around 2600 J/kg with no convective
inhibition, although shear values are not especially impressive.
Latest SPC mesoanalysis indicates CAPE`s are over 3000 J/kg south
of I-72, as dew points of 70 degrees have made it as far north as
Taylorville. Warm front extends from southern Nebraska along the
Iowa/Missouri border, but becomes more diffuse in northern
Illinois where it is more of a dew point discontinuity.
Thunderstorms have been percolating most of the day across the
Ohio Valley, and a persistent, small MCS is advancing across Iowa.
Some development has recently started as well across northeast
Missouri south of the main MCS. Has been quiet in our area the
last few hours, but latest radar returns are starting to show
thunderstorms developing between Taylorville and St Louis.
The primary forecast concern remains with the severe weather
threat over the next 24 to 36 hours.
SHORT TERM...Tonight through Tuesday:
Latest runs of the HRRR have been persistent with the Iowa storms
affecting more of the northern third of Illinois, with more
scattered strong/severe storms affecting our area through about
7 pm. Shear parameters don`t really improve any in our area, so
thinking that hail/wind threat will be the primary concerns here
with the tornado threat closer to the warm front. After sunset,
capping of the atmosphere will begin in the warm sector. Have
maintained some 30-40% PoP`s after midnight northwest of the
Illinois River, and slight chances as far east as I-55, with dry
conditions across the southeast half of the forecast area.
Similar convective parameters expected on Monday, with CAPE`s
rising to 2500-3000 J/kg, although shear remains on the low side.
Day2 slight risk basically along and northwest of the Illinois
River, where the shear will be a bit higher as it is closer to the
incoming cold front, and severe weather threat will mainly be mid
afternoon to early evening. With the front slowing down a tad,
will keep any PoP`s east of I-57 around 20% during the day, while
likely PoP`s around 60% found during the afternoon along/west of
the Illinois River. Have maintained the 60-70% PoP`s everywhere
during the night as the front slowly moves through, and over the
eastern CWA on Tuesday with some 80% values south of I-70 Tuesday.
Severe weather threat on Tuesday appears minimal, and would be
near the Indiana border if any did occur.
LONG TERM...Wednesday through Sunday:
A broad upper trough will be dominating much of the eastern half
of the nation into the first part of the weekend, with cool
conditions prevailing. The ECMWF has been persistent with a closed
upper low forming by late Thursday over the Great Lakes, then
lifting northward, while the GFS keeps a more progressive trough.
Toward the end of the weekend, the trough will finally start to
break down as an upper low digs southward across the Pacific
Northwest, causing rising heights over the center of the nation.
Most challenging area in this forecast period is with rain on
Wednesday. The tail end of the NAM is trending toward the solution
favored by the ECMWF and GEM for the last few days, with a surface
low riding northeast along the base of the trough, although the
NAM is much further west with it. The GFS has keep its surface
features much weaker and further east. Have kept the likely PoP`s
on Wednesday across the southeast third of the area, although the
ECMWF/GEM solutions would likely require this to be expanded
further northwest toward the I-55 corridor. Thursday and Friday,
the rain will be much more scattered in nature, as weak troughs
rotate around through the broad upper trough. Rain chances will
diminish this weekend as the upper flow flattens.
Geelhart
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS CHICAGO/ROMEOVILLE IL
804 PM CDT SUN MAY 11 2014
.MESOSCALE DISCUSSION...
804 PM CDT
THE TORNADO WARNED CELL ACROSS CENTRAL NEWTON AND JASPER COUNTIES
IS FOR A RAPIDLY INTENSIFYING UPDRAFT WITH VERTICALLY CONSISTENT
AND STRENGTHENING ROTATION. THIS STORM IS AT THE VERY SOUTHERN
EDGE OF THE ONGOING CLUSTER/COMPLEX AND IS FEEDING ON 100-150 J/KG
OF 0-3KM CAPE...AND A MODIFIED RAP SOUNDING DOES INDICATE LIFT
FROM THE SURFACE ALONG WITH LOWERING LCLS FROM EARLIER ACTIVITY
FURTHER WEST AND NORTH. THE 0-1KM SHEAR IS SLIGHTLY MARGINAL AT 15
KT BUT INCREASING WITH THE STRENGTHENING LOW-LEVEL JET. IN
ADDITION...A FUNNEL CLOUD REPORT WAS RECEIVED FROM JUST NORTH OF
BROOK INDIANA AT 757 PM WITH THIS STORM.
MTF
&&
.DISCUSSION...
300 PM CDT
FORECAST CONCERNS ARE MAINLY ON THE IMMEDIATE SEVERE WEATHER
CHANCES THROUGH EARLY/MID EVENING. ALSO FOCUS ON THE SEVERE
WEATHER POTENTIAL ON MONDAY...PRIMARILY MONDAY LATE AFTERNOON INTO
THE NIGHTTIME PERIOD.
OVERNIGHT INTO MONDAY MORNING...
STRONG UPPER JET WILL PROPAGATE AROUND THE UPPER TROUGH LATE
TONIGHT INTO THE MORNING ON MONDAY AND WITH THAT LEAD TO FURTHER
AMPLIFYING OF THE UPSTREAM RIDGE...INCLUDING BUILDING HEIGHTS
ACROSS MUCH OF THE FORECAST AREA. MUCH OF THE FORCING FOR
RAIN/STORMS IN THIS PERIOD WOULD BE FOCUSED TO THE WEST AND NORTH
IN SUCH A PATTERN. THE STRONG LOW-LEVEL JET WILL AT LEAST IN PART
BE OVER THE AREA...HOWEVER THE NOSE OF IT WILL BE POINTED FURTHER
NORTH. CONVECTIVE CHANCES LOOK MINIMAL AND MAINLY THE NORTHWEST
FORECAST AREA TOWARD ROCKFORD. CHANCES MAY BE INCREASED SOMEWHAT
IF ANY ORGANIZED CONVECTION FROM THE CENTRAL PLAINS WERE TO
PROPAGATE EASTWARD INTO NORTHERN IL...BUT THE GRADUALLY MORE
MERIDIONAL FLOW AND ORIENTATION OF FORECAST CORFIDI VECTORS WOULD
PUSH MUCH OF THE CONVECTION NORTH OF THE AREA. LOW TEMPS WILL BE
BALMY WITH CONTINUED SOUTHERLY FLOW AND HIGH DEW POINT AIR...WITH
SOME PLACES EXPERIENCING SOME WARMING OF TEMPS LATER THIS
EVENING...ESPECIALLY THOSE IMPACTED BY EARLY EVE CONVECTION AND
THOSE COMMUNITIES NEAR THE LAKE SHORE THAT HAD AFTERNOON/EVE
COOLING.
MONDAY AFTERNOON THROUGH TUESDAY...
THE UPPER TROUGH WILL CONTINUE TO AMPLIFY AS THE UPPER JET TO ITS
FRONT AND BACK INTENSITY. A WARM AND MUGGY DAY IS ANTICIPATED
MONDAY. CONVECTIVE INHIBITION ON MONDAY AFTERNOON DOES LOOK TO BE
OVERCOME BUT A FOCUS IS NOT OVERLY EVIDENT IN OUR FORECAST AREA.
GRADUALLY MORE CONVERGENCE AND INCREASING DEEP LAYER MOISTURE AND
UPWARD MOTION IS FORECAST TO MOVE EASTWARD ACROSS MAINLY NORTH
CENTRAL ILLINOIS LATE IN THE DAY INTO EARLY EVE AND EASE ITS WAY
EASTWARD THROUGH THE REMAINDER OF THE NIGHT. THIS LOOKS LIKE A
PERIOD OF STORMS MOVING NORTHEAST WITHIN THE DEEP MOIST PLUME.
THE SEVERE POTENTIAL WOULD SEEM MOST FAVORED WITH THE INITIAL
CONVECTION IN THE LATE AFTERNOON/EVE AND THEN A GENERAL WANING
LATER INTO THE NIGHT. LOCALLY HEAVY RAINFALL WILL BE PROBABLE IN
SOME OF THESE STORMS AS THE PWATS ARE FORECAST TO BE AROUND 1.50
INCHES AND DEEP MOISTURE CONVERGENCE WILL BE ORIENTED PARALLEL TO
THE UPPER FLOW. THIS PLUME WILL SHIFT EASTWARD THROUGH TUESDAY
MORNING AND LIKELY POPS CERTAINLY SEEM JUSTIFIED TUESDAY MORNING. IF
THE FRONT IS SLOW ENOUGH SOME AFTERNOON ENHANCEMENT OF A FEW STORMS
COULD HAPPEN IN THE EAST...BUT THIS SEEMS MOST FAVORED EAST OF THE
FORECAST AREA AT THIS TIME.
THE COLD AIR ADVECTION WITH THE COLD FRONT...ALONG WITH POTENTIALLY
SOME ANAFRONTAL SHOWERS...WILL LIKELY LEAD TO FALLING TEMPS IN SOME
PLACES AT LEAST AT TIMES ON TUESDAY.
WEDNESDAY AND BEYOND...
LITTLE CHANGES MADE TO THIS PART OF THE FORECAST DUE TO ONGOING
HIGHER IMPACT WEATHER. LARGE MODEL DIFFERENCES EXIST IN THE WED-THU
TIME FRAME...WITH THE 12Z EC COMING IN SLOWER AND MORE AGGRESSIVE
WITH A LOW RIDING UP THE BAROCLINIC ZONE TO OUR EAST. THIS PROVIDES
WIDESPREAD SHOWERS WEDNESDAY AFTERNOON THROUGH EARLY THURSDAY AND
PARTICULARY COOL TEMPS. WITH AN EC/GFS/GOING FORECAST BLEND THIS
PROVIDES A FEW PERIODS OF CHANCE POPS.
TEMPS TO LOOK TO BE BELOW NORMAL NO MATTER WHICH MODEL VERIFIES IN
THE WED-FRI TIME FRAME. IF CONDITIONS CLEAR AND SURFACE RIDGING
MOVES OVER...POSSIBLY THU NIGHT...THERE PROBABLY WILL BE A CONCERN
FOR FROST.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* SHRA/TSRA THROUGH MID EVENING.
* WIND DIRECTIONS THIS EVENING.
* POSSIBLE MVFR CIGS MONDAY MORNING.
* STRONG/GUSTY SOUTHERLY WINDS MONDAY.
* POSSIBLE TSRA LATE MONDAY AFTERNOON/MONDAY EVENING. CMS
//DISCUSSION...UPDATED 00Z...
TSRA HAS CONTINUED TO CONSOLIDATE AND MOVE EAST. ADDITIONAL SHRA
WITH AN OCCASIONAL LIGHTNING STRIKE WILL CONTINUE FOR THE NEXT
HOUR OR TWO. THE BULK OF THIS ACTIVITY IS EXPECTED TO BE EAST OR
SOUTHEAST OF THE CHICAGO AREA TERMINALS BY 02Z-03Z AND HAVE
MAINTAINED SIMILAR TIMING/TRENDS FROM THE PREVIOUS FORECAST.
ANOTHER LINE OF TSRA OVER THE PLAINS WILL NEED TO BE MONITORED AS
IT MOVES EAST OVERNIGHT. CONFIDENCE IS LOW REGARDING HOW FAR EAST
THIS WILL MOVE BEFORE DISSIPATING. SOME OF THE SHORT TERM GUIDANCE
WOULD SUGGEST THAT THIS WILL MAKE IT INTO THE RFD AREA BY DAYBREAK.
INCLUDED A VCSH MENTION THERE BUT FURTHER EAST...MAINTAINED DRY
FORECAST AND TRENDS WILL NEED TO BE MONITORED THROUGH THE NIGHT.
LOW CONFIDENCE CONTINUES FOR PRECIP CHANCES THROUGH SUNSET MONDAY.
WHILE MUCH OF MONDAY LOOKS DRY...ITS POSSIBLE THAT ISOLATED TSRA
MAY DEVELOP ACROSS PARTS OF NORTHERN IL...POSSIBLY REMAINING NORTH
OF THE TERMINALS.
WITH THE LOW LEVELS NOW SATURATED...AS LOW LEVEL MOISTURE
INCREASES...THERE IS A POTENTIAL FOR LOW MVFR CIGS TO DEVELOP
OVERNIGHT AND PERSIST INTO THE MID MORNING HOURS. CONFIDENCE IS
NOT HIGH AND MAINTAINED SCATTERED MENTION FOR NOW.
WINDS WILL SETTLE BACK TO SOUTHEAST AROUND 10KTS THIS EVENING THEN
TURN MORE SOUTHERLY OVERNIGHT WITH THE POTENTIAL FOR SOME GUSTS
INTO THE MID TEEN RANGE. WIND SPEEDS/GUSTS WILL THEN STEADILY
INCREASE THROUGH THE MORNING WITH GUSTS INTO THE MID TO UPPER 20
KT RANGE FOR THE AFTERNOON.
LOW LEVEL WINDS NOW APPEAR LOW ENOUGH OVERNIGHT INTO MONDAY
MORNING THAT LOW LEVEL WIND SHEAR CRITERIA WILL NOT BE MET AND
REMOVED IT FROM THIS FORECAST. CMS
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* HIGH FOR SHRA/TSRA EARLY THIS EVENING.
* LOW FOR WIND DIRECTIONS THIS EVENING...MEDIUM FOR WINDS FOR THE
REST OF THE PERIOD.
* LOW FOR MVFR CIGS OVERNIGHT/MONDAY MORNING.
* LOW FOR TSRA LATE MONDAY AFTERNOON/MONDAY NIGHT. CMS
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
* TUESDAY...TSRA LIKELY IN THE MORNING.
* WEDNESDAY...CHANCE OF SHRA.
* THURSDAY...CHANCE OF SHRA.
* FRIDAY...SLIGHT CHANCE OF SHRA.
* SATURDAY...DRY/VFR.
&&
.MARINE...
242 PM...LOW PRESSURE OVER KANSAS WILL MOVE NORTHEAST TO LAKE
SUPERIOR TUESDAY MORNING. AS IT DOES...A WARM FRONT EXTENDING EAST
FROM THE LOW WILL MOVE NORTH ACROSS THE LAKE TONIGHT THROUGH
MONDAY NIGHT...SHIFTING EASTERLY WINDS SOUTHERLY. LOW LEVEL
MOISTURE WILL ALSO BE INCREASING AND AS IT SPREADS ACROSS THE
COOLER LAKE...AREAS OF FOG ARE POSSIBLE AND SOME OF THE FOG MAY
BECOME DENSE. CURRENT WIND SPEEDS ARE FAIRLY LIGHT IN THE 5-15 KT
RANGE AND WILL INCREASE INTO THE 15-25KT RANGE AND REMAIN THERE
UNTIL A COLD FRONT MOVES ACROSS THE LAKE TUESDAY MORNING. THERE IS
A POTENTIAL FOR WINDS TO BE A BIT STRONGER ON MONDAY...ESPECIALLY
WITH THE EASTERLY FLOW NORTH OF THE WARM FRONT ACROSS NORTHERN
LAKE MICHIGAN. THERE REMAINS UNCERTAINTY REGARDING THE POTENTIAL
FOR STRONG NORTHERLY WINDS WEDNESDAY NIGHT INTO THURSDAY AS LOW
PRESSURE DEEPENS MOVING NORTH ACROSS THE GREAT LAKES REGION. THIS
TIME PERIOD WILL NEED TO BE MONITORED FOR HIGHER NORTHERLY WIND
SPEEDS. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
711 PM CDT SUN MAY 11 2014
.MESOSCALE DISCUSSION...
550 PM CDT
THE SEVERE WEATHER THREAT CONTINUES ACROSS THE AREA. A LOCAL
EXPANSION OF THE SEVERE THUNDERSTORM WATCH HAS BEEN DONE TO
INCLUDE THE FAR SOUTHEAST COUNTY WARNING AREA.
STORMS SOME OF WHICH ARE SEVERE CONTINUE TO PROPAGATE EAST
FEEDING ON UNCAPPED AND VERY UNSTABLE AIR...WITH MLCAPE VALUES OF
2000-3000 J/KG ACROSS THE AREA. THIS AREA NORTH OF THE WARM FRONT
HAD DEVELOPED FAIRLY STEEP LOW-LEVEL LAPSE RATES PER AMDAR
SOUNDINGS AND THUS INCREASED SOME OF THE WIND POTENTIAL. RADAR HAS
ALSO INDICATED SOME OUTFLOWS QUICKLY RACING OUT FROM THESE STORMS
AS EVIDENCE TO THIS. WIND AND HAIL THREATS CONTINUE WITH THE
STRONGEST CORES...INCLUDING ONE APPROACHING DOWNTOWN CHICAGO AS OF
550 PM.
AN ARC OF SEVERE STORMS FROM NEAR KEWANEE EAST SOUTHEAST TOWARD
WATSEKA IS LIFTING SLOWLY NORTHEAST. THIS IS JUST AHEAD OF REMNANT
MCV. AS MID-LEVEL WINDS PICK UP FROM THE WEST...OVERALL
SHEAR/INSTABILITY SPECTRUM WILL CONTINUE TO FAVOR SEVERE
POTENTIAL WITH THESE AS WELL...WITH MODE LIKELY CONTINUING TO
SHIFT TO LESS DISCRETE AS MESOSCALE COLD POOLS INTERACT.
IN ADDITION...A HEAVY RAIN AND POSSIBLE FLOODING THREAT MAY
TEMPORARILY EVOLVE EARLY THIS EVE NEAR THE I-80 CORRIDOR AS THIS
AFOREMENTIONED ARC OF STORMS BECOMES MORE WEST-TO-EAST ORIENTED
AHEAD OF MCV. COULD BE A 1-3 HOUR EPISODE OF MODERATE TO HEAVY
RAINFALL RATES. THIS IS BEING MONITORED CLOSELY.
THE SECONDARY WARM FRONT CONTINUES TO REMAIN PRIMARILY TO THE
SOUTH OF THE AREA AND SOMEWHAT DIFFUSE. WHILE PRESSURE FALLS AND
HIGHER DEW POINT AIR IS EVOLVING INTO THE SOUTHERN FORECAST
AREA...THE DEGREE OF BACKING WINDS HAS NOT BEEN THAT
NOTEWORTHY...AND THUS THE TORNADO THREAT IS DIMINISHING. STILL A
NONZERO CHANCE THOUGH...MAINLY SOUTH OF INTERSTATE 80 AND WEST OF
ILLINOIS HIGHWAY 47.
MTF
&&
.DISCUSSION...
300 PM CDT
FORECAST CONCERNS ARE MAINLY ON THE IMMEDIATE SEVERE WEATHER
CHANCES THROUGH EARLY/MID EVENING. ALSO FOCUS ON THE SEVERE
WEATHER POTENTIAL ON MONDAY...PRIMARILY MONDAY LATE AFTERNOON INTO
THE NIGHTTIME PERIOD.
OVERNIGHT INTO MONDAY MORNING...
STRONG UPPER JET WILL PROPAGATE AROUND THE UPPER TROUGH LATE
TONIGHT INTO THE MORNING ON MONDAY AND WITH THAT LEAD TO FURTHER
AMPLIFYING OF THE UPSTREAM RIDGE...INCLUDING BUILDING HEIGHTS
ACROSS MUCH OF THE FORECAST AREA. MUCH OF THE FORCING FOR
RAIN/STORMS IN THIS PERIOD WOULD BE FOCUSED TO THE WEST AND NORTH
IN SUCH A PATTERN. THE STRONG LOW-LEVEL JET WILL AT LEAST IN PART
BE OVER THE AREA...HOWEVER THE NOSE OF IT WILL BE POINTED FURTHER
NORTH. CONVECTIVE CHANCES LOOK MINIMAL AND MAINLY THE NORTHWEST
FORECAST AREA TOWARD ROCKFORD. CHANCES MAY BE INCREASED SOMEWHAT
IF ANY ORGANIZED CONVECTION FROM THE CENTRAL PLAINS WERE TO
PROPAGATE EASTWARD INTO NORTHERN IL...BUT THE GRADUALLY MORE
MERIDIONAL FLOW AND ORIENTATION OF FORECAST CORFIDI VECTORS WOULD
PUSH MUCH OF THE CONVECTION NORTH OF THE AREA. LOW TEMPS WILL BE
BALMY WITH CONTINUED SOUTHERLY FLOW AND HIGH DEW POINT AIR...WITH
SOME PLACES EXPERIENCING SOME WARMING OF TEMPS LATER THIS
EVENING...ESPECIALLY THOSE IMPACTED BY EARLY EVE CONVECTION AND
THOSE COMMUNITIES NEAR THE LAKE SHORE THAT HAD AFTERNOON/EVE
COOLING.
MONDAY AFTERNOON THROUGH TUESDAY...
THE UPPER TROUGH WILL CONTINUE TO AMPLIFY AS THE UPPER JET TO ITS
FRONT AND BACK INTENSITY. A WARM AND MUGGY DAY IS ANTICIPATED
MONDAY. CONVECTIVE INHIBITION ON MONDAY AFTERNOON DOES LOOK TO BE
OVERCOME BUT A FOCUS IS NOT OVERLY EVIDENT IN OUR FORECAST AREA.
GRADUALLY MORE CONVERGENCE AND INCREASING DEEP LAYER MOISTURE AND
UPWARD MOTION IS FORECAST TO MOVE EASTWARD ACROSS MAINLY NORTH
CENTRAL ILLINOIS LATE IN THE DAY INTO EARLY EVE AND EASE ITS WAY
EASTWARD THROUGH THE REMAINDER OF THE NIGHT. THIS LOOKS LIKE A
PERIOD OF STORMS MOVING NORTHEAST WITHIN THE DEEP MOIST PLUME.
THE SEVERE POTENTIAL WOULD SEEM MOST FAVORED WITH THE INITIAL
CONVECTION IN THE LATE AFTERNOON/EVE AND THEN A GENERAL WANING
LATER INTO THE NIGHT. LOCALLY HEAVY RAINFALL WILL BE PROBABLE IN
SOME OF THESE STORMS AS THE PWATS ARE FORECAST TO BE AROUND 1.50
INCHES AND DEEP MOISTURE CONVERGENCE WILL BE ORIENTED PARALLEL TO
THE UPPER FLOW. THIS PLUME WILL SHIFT EASTWARD THROUGH TUESDAY
MORNING AND LIKELY POPS CERTAINLY SEEM JUSTIFIED TUESDAY MORNING. IF
THE FRONT IS SLOW ENOUGH SOME AFTERNOON ENHANCEMENT OF A FEW STORMS
COULD HAPPEN IN THE EAST...BUT THIS SEEMS MOST FAVORED EAST OF THE
FORECAST AREA AT THIS TIME.
THE COLD AIR ADVECTION WITH THE COLD FRONT...ALONG WITH POTENTIALLY
SOME ANAFRONTAL SHOWERS...WILL LIKELY LEAD TO FALLING TEMPS IN SOME
PLACES AT LEAST AT TIMES ON TUESDAY.
WEDNESDAY AND BEYOND...
LITTLE CHANGES MADE TO THIS PART OF THE FORECAST DUE TO ONGOING
HIGHER IMPACT WEATHER. LARGE MODEL DIFFERENCES EXIST IN THE WED-THU
TIME FRAME...WITH THE 12Z EC COMING IN SLOWER AND MORE AGGRESSIVE
WITH A LOW RIDING UP THE BAROCLINIC ZONE TO OUR EAST. THIS PROVIDES
WIDESPREAD SHOWERS WEDNESDAY AFTERNOON THROUGH EARLY THURSDAY AND
PARTICULARY COOL TEMPS. WITH AN EC/GFS/GOING FORECAST BLEND THIS
PROVIDES A FEW PERIODS OF CHANCE POPS.
TEMPS TO LOOK TO BE BELOW NORMAL NO MATTER WHICH MODEL VERIFIES IN
THE WED-FRI TIME FRAME. IF CONDITIONS CLEAR AND SURFACE RIDGING
MOVES OVER...POSSIBLY THU NIGHT...THERE PROBABLY WILL BE A CONCERN
FOR FROST.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* SHRA/TSRA THROUGH MID EVENING.
* WIND DIRECTIONS THIS EVENING.
* POSSIBLE MVFR CIGS MONDAY MORNING.
* STRONG/GUSTY SOUTHERLY WINDS MONDAY.
* POSSIBLE TSRA LATE MONDAY AFTERNOON/MONDAY EVENING. CMS
//DISCUSSION...UPDATED 00Z...
TSRA HAS CONTINUED TO CONSOLIDATE AND MOVE EAST. ADDITIONAL SHRA
WITH AN OCCASIONAL LIGHTNING STRIKE WILL CONTINUE FOR THE NEXT
HOUR OR TWO. THE BULK OF THIS ACTIVITY IS EXPECTED TO BE EAST OR
SOUTHEAST OF THE CHICAGO AREA TERMINALS BY 02Z-03Z AND HAVE
MAINTAINED SIMILAR TIMING/TRENDS FROM THE PREVIOUS FORECAST.
ANOTHER LINE OF TSRA OVER THE PLAINS WILL NEED TO BE MONITORED AS
IT MOVES EAST OVERNIGHT. CONFIDENCE IS LOW REGARDING HOW FAR EAST
THIS WILL MOVE BEFORE DISSIPATING. SOME OF THE SHORT TERM GUIDANCE
WOULD SUGGEST THAT THIS WILL MAKE IT INTO THE RFD AREA BY DAYBREAK.
INCLUDED A VCSH MENTION THERE BUT FURTHER EAST...MAINTAINED DRY
FORECAST AND TRENDS WILL NEED TO BE MONITORED THROUGH THE NIGHT.
LOW CONFIDENCE CONTINUES FOR PRECIP CHANCES THROUGH SUNSET MONDAY.
WHILE MUCH OF MONDAY LOOKS DRY...ITS POSSIBLE THAT ISOLATED TSRA
MAY DEVELOP ACROSS PARTS OF NORTHERN IL...POSSIBLY REMAINING NORTH
OF THE TERMINALS.
WITH THE LOW LEVELS NOW SATURATED...AS LOW LEVEL MOISTURE
INCREASES...THERE IS A POTENTIAL FOR LOW MVFR CIGS TO DEVELOP
OVERNIGHT AND PERSIST INTO THE MID MORNING HOURS. CONFIDENCE IS
NOT HIGH AND MAINTAINED SCATTERED MENTION FOR NOW.
WINDS WILL SETTLE BACK TO SOUTHEAST AROUND 10KTS THIS EVENING THEN
TURN MORE SOUTHERLY OVERNIGHT WITH THE POTENTIAL FOR SOME GUSTS
INTO THE MID TEEN RANGE. WIND SPEEDS/GUSTS WILL THEN STEADILY
INCREASE THROUGH THE MORNING WITH GUSTS INTO THE MID TO UPPER 20
KT RANGE FOR THE AFTERNOON.
LOW LEVEL WINDS NOW APPEAR LOW ENOUGH OVERNIGHT INTO MONDAY
MORNING THAT LOW LEVEL WIND SHEAR CRITERIA WILL NOT BE MET AND
REMOVED IT FROM THIS FORECAST. CMS
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* HIGH FOR SHRA/TSRA EARLY THIS EVENING.
* LOW FOR WIND DIRECTIONS THIS EVENING...MEDIUM FOR WINDS FOR THE
REST OF THE PERIOD.
* LOW FOR MVFR CIGS OVERNIGHT/MONDAY MORNING.
* LOW FOR TSRA LATE MONDAY AFTERNOON/MONDAY NIGHT. CMS
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
* TUESDAY...TSRA LIKELY IN THE MORNING.
* WEDNESDAY...CHANCE OF SHRA.
* THURSDAY...CHANCE OF SHRA.
* FRIDAY...SLIGHT CHANCE OF SHRA.
* SATURDAY...DRY/VFR.
&&
.MARINE...
242 PM...LOW PRESSURE OVER KANSAS WILL MOVE NORTHEAST TO LAKE
SUPERIOR TUESDAY MORNING. AS IT DOES...A WARM FRONT EXTENDING EAST
FROM THE LOW WILL MOVE NORTH ACROSS THE LAKE TONIGHT THROUGH
MONDAY NIGHT...SHIFTING EASTERLY WINDS SOUTHERLY. LOW LEVEL
MOISTURE WILL ALSO BE INCREASING AND AS IT SPREADS ACROSS THE
COOLER LAKE...AREAS OF FOG ARE POSSIBLE AND SOME OF THE FOG MAY
BECOME DENSE. CURRENT WIND SPEEDS ARE FAIRLY LIGHT IN THE 5-15 KT
RANGE AND WILL INCREASE INTO THE 15-25KT RANGE AND REMAIN THERE
UNTIL A COLD FRONT MOVES ACROSS THE LAKE TUESDAY MORNING. THERE IS
A POTENTIAL FOR WINDS TO BE A BIT STRONGER ON MONDAY...ESPECIALLY
WITH THE EASTERLY FLOW NORTH OF THE WARM FRONT ACROSS NORTHERN
LAKE MICHIGAN. THERE REMAINS UNCERTAINTY REGARDING THE POTENTIAL
FOR STRONG NORTHERLY WINDS WEDNESDAY NIGHT INTO THURSDAY AS LOW
PRESSURE DEEPENS MOVING NORTH ACROSS THE GREAT LAKES REGION. THIS
TIME PERIOD WILL NEED TO BE MONITORED FOR HIGHER NORTHERLY WIND
SPEEDS. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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Area Forecast Discussion
National Weather Service Lincoln IL
649 PM CDT Sun May 11 2014
.DISCUSSION...
ISSUED 248 PM CDT Sun May 11 2014
Air mass destabilizing quickly across central and southeast
Illinois early this afternoon. 18Z upper air sounding from our
office showing CAPE of around 2600 J/kg with no convective
inhibition, although shear values are not especially impressive.
Latest SPC mesoanalysis indicates CAPE`s are over 3000 J/kg south
of I-72, as dew points of 70 degrees have made it as far north as
Taylorville. Warm front extends from southern Nebraska along the
Iowa/Missouri border, but becomes more diffuse in northern
Illinois where it is more of a dew point discontinuity.
Thunderstorms have been percolating most of the day across the
Ohio Valley, and a persistent, small MCS is advancing across Iowa.
Some development has recently started as well across northeast
Missouri south of the main MCS. Has been quiet in our area the
last few hours, but latest radar returns are starting to show
thunderstorms developing between Taylorville and St Louis.
The primary forecast concern remains with the severe weather
threat over the next 24 to 36 hours.
SHORT TERM...Tonight through Tuesday:
Latest runs of the HRRR have been persistent with the Iowa storms
affecting more of the northern third of Illinois, with more
scattered strong/severe storms affecting our area through about
7 pm. Shear parameters don`t really improve any in our area, so
thinking that hail/wind threat will be the primary concerns here
with the tornado threat closer to the warm front. After sunset,
capping of the atmosphere will begin in the warm sector. Have
maintained some 30-40% PoP`s after midnight northwest of the
Illinois River, and slight chances as far east as I-55, with dry
conditions across the southeast half of the forecast area.
Similar convective parameters expected on Monday, with CAPE`s
rising to 2500-3000 J/kg, although shear remains on the low side.
Day2 slight risk basically along and northwest of the Illinois
River, where the shear will be a bit higher as it is closer to the
incoming cold front, and severe weather threat will mainly be mid
afternoon to early evening. With the front slowing down a tad,
will keep any PoP`s east of I-57 around 20% during the day, while
likely PoP`s around 60% found during the afternoon along/west of
the Illinois River. Have maintained the 60-70% PoP`s everywhere
during the night as the front slowly moves through, and over the
eastern CWA on Tuesday with some 80% values south of I-70 Tuesday.
Severe weather threat on Tuesday appears minimal, and would be
near the Indiana border if any did occur.
LONG TERM...Wednesday through Sunday:
A broad upper trough will be dominating much of the eastern half
of the nation into the first part of the weekend, with cool
conditions prevailing. The ECMWF has been persistent with a closed
upper low forming by late Thursday over the Great Lakes, then
lifting northward, while the GFS keeps a more progressive trough.
Toward the end of the weekend, the trough will finally start to
break down as an upper low digs southward across the Pacific
Northwest, causing rising heights over the center of the nation.
Most challenging area in this forecast period is with rain on
Wednesday. The tail end of the NAM is trending toward the solution
favored by the ECMWF and GEM for the last few days, with a surface
low riding northeast along the base of the trough, although the
NAM is much further west with it. The GFS has keep its surface
features much weaker and further east. Have kept the likely PoP`s
on Wednesday across the southeast third of the area, although the
ECMWF/GEM solutions would likely require this to be expanded
further northwest toward the I-55 corridor. Thursday and Friday,
the rain will be much more scattered in nature, as weak troughs
rotate around through the broad upper trough. Rain chances will
diminish this weekend as the upper flow flattens.
Geelhart
&&
.AVIATION...
ISSUED 649 PM CDT Sun May 11 2014
VFR conditions expected across the central Illinois terminals
through the 00Z TAF valid time. A warm front has lifted north of
the area today, associated with a few showers/storms. However, now
mainly dry conditions are anticipated until the trailing cold
front associated with the same storm system pushes into the area
Monday night. While this dry period should last across most of the
area until after 00Z Tuesday, VFR low/mid cloud cigs will last
for much of the next 24 hours.
Gusty southerly winds will fall off this evening with the loss of
diurnal heating/mixing. This, and an approaching low level jet,
will allow LLWS to develop later tonight. The LLWS will end as
deeper mixing and gustiness returns Monday morning.
Bak
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
100 PM CDT SAT MAY 10 2014
.DISCUSSION...
252 AM CDT
PRIMARY FORECAST CHALLENGE THIS MORNING REMAINS THE CONVECTIVE
POTENTIAL STARTING TONIGHT AND CONTINUING AT TIMES THROUGH MONDAY
NIGHT. SECONDARY CONCERNS INCLUDE TEMPERATURES SUNDAY INTO MONDAY
AND THEN PRECIP CHANCES NEXT WEEK.
HIGH PRESSURE OVER THE REGION TODAY SHOULD RESULT IN A PRETTY NICE
DAY OVERALL. SLUG OF HIGH CLOUDINESS OVER MISSOURI IS ASSOCIATED
WITH A SHORTWAVE ALOFT...MUCH MORE DEFINED AT 250MB THAN AT 500MB
WITH VERY LITTLE REFLECTION AT 700MB. DRY LOW LEVELS AND ABSENCE OF
FORCING SHOULD KEEP THIS ONLY A HIGH CLOUD PRODUCER AND MAINLY THIS
MORNING. LIGHT WIND REGIME SHOULD ALLOW LAKE BREEZE TO FORM BY EARLY
AFTERNOON WITH FALLING TEMPS NEAR THE LAKE THIS AFTERNOON...BUT
FAIRLY MILD CONDITIONS AWAY FROM THE LAKE.
TONIGHT LOW LEVEL JET SHOULD RESULT IN STRENGTHENING LOW LEVEL
THETA-E ADVECTION AND LIKELY THE DEVELOPING OF SHOWERS AND
THUNDERSTORMS OVER MISSOURI THIS EVENING. THIS ACTIVITY IS EXPECTED
TO PUSH EAST INTO ILLINOIS LATE TONIGHT...HOWEVER GUIDANCE IS
INCREASINGLY SUGGESTING THAT THE STRONGEST MOISTURE CONVERGENCE WILL
REMAIN FARTHER SOUTH ACROSS CENTRAL ILLINOIS WITH FAR LESSER SUPPORT
FROM PRECIP FARTHER NORTH. HAVE DECREASED POPS CONSIDERABLY OVER
NORTHERN 2/3RD OF CWA...MAINTAINING CHANCE POPS MOSTLY FOR
CONTINUITY SAKE AS IT LOOKS MORE AND MORE LIKELY THAT IT COULD STAY
DRY ALTOGETHER NORTH OF I-80. FAR SOUTHERN CWA STANDS A BETTER
CHANCE OF SEEING SOME OF THIS CONVECTION AND HAVE MAINTAINED HIGHER
POPS THERE.
SUNDAY SHOULD SEE DEVELOPING SOUTHERLY FLOW AS CYCLOGENESIS TAKES
PLACE OVER THE PLAINS WITH STRENGTHENING WARM AND MOIST ADVECTION
INTO THE AREA. DOES APPEAR AS THOUGH A SOMEWHAT ILL DEFINED WARM
FRONT WILL DEVELOP AND LIFT NORTH ACROSS THE CWA SUNDAY BUT
OTHERWISE SYNOPTIC SCALE FORCING LOOKS SOMEWHAT
NEBULOUS...PARTICULARLY IN LIGHT IN STRONG HEIGHT RISES DOWNSTREAM
OF THE AMPLIFYING TROUGH TO OUR WEST. CERTAINLY PLAUSIBLE THAT
REMNANT MCV FROM TODAY`S CONVECTION OVER THE PLAINS OR FORCING
ALONG THE WEAK WARM FRONT COULD BE ENOUGH TO KICK OF THUNDERSTORMS
SUNDAY AFTERNOON...BUT OVERALL SYNOPTIC PATTERN WOULD ARGUE FOR
LARGELY A RAIN-FREE DAY ACROSS THE CWA AND HAVE ATTEMPTED TO SCALE
BACK POPS SOME. WORTH NOTING HOWEVER...THAT MODERATE INSTABILITY
SHOULD DEVELOP WITH THE INCREASINGLY WARM/HUMID AIRMASS AND WITH
STILL RESPECTABLE VALUES OF DEEP LAYER SHEAR THREAT DOES EXISTS FOR
ANY CONVECTION THAT DOES DEVELOP SUNDAY AFTERNOON TO BE SEVERE. NOT
TO MENTION THAT ILLINOIS WARM FRONTS SEEM TO LIKE TO PRODUCE
"SURPRISES" THIS TIME OF YEAR.
SOUTHERLY WINDS ON SUNDAY LOOK LIGHT ENOUGH FOR AT LEAST AN ILLINOIS
SHORE LAKE BREEZE TO DEVELOP IN THE AFTERNOON...PARTICULARLY IF WARM
FRONT BECOMES BETTER DEFINED AND WINDS MORE BACKED AHEAD OF IT.
ASSUMING THIS SCENARIO PANS OUT DID KEEP LAKE COOLING IN THE GRIDS
SUNDAY WITH FAIRLY WARM TEMPERATURES EXPECTED ELSEWHERE. BY SUNDAY
NIGHT THE MAJORITY OF GUIDANCE AGREES THAT THE WARM FRONT WILL
BECOME BETTER DEFINED TO OUR NORTH OVER WISCONSIN WITH FOCUS FOR
POTENTIALLY SIGNIFICANT CONVECTIVE EVENT NORTH OF THE BORDER WITH
OUR CWA JUST UNSEASONABLY WARM AND STEAMY WITH LOWS STRUGGLING TO
DIP BELOW 70 DEGREES AS DEWPOINTS CLIMB WELL INTO THE 60S AND
MODERATELY STRONG WINDS THROUGH THE NIGHT. GFS IS THE ODD MAN OUT
KEEPING WARM FRONT AND SIGNIFICANT CONVECTION FARTHER SOUTH INTO OUR
CWA. HAVE TRENDED POPS DOWN SUNDAY NIGHT...ESPECIALLY SOUTHERN
CWA...BUT RELUCTANT TO GO TOO LOW GIVEN GFS SOLUTION AND POSSIBILITY
THAT EVEN IF OTHER MODELS VERIFY OUTFLOW COULD PUSH SOUTH AND ALLOW
CONVECTION TO PROPAGATE INTO OUR FAR NORTHERN CWA. UNUSUALLY HIGH
PWATS AND SLOW MOVING NATURE OF WARM FRONT RAISE CONCERNS FOR HEAVY
RAINFALL AND FLASH FLOODING...THOUGH THANKFULLY THAT APPEARS TO BE
MORE OF A THREAT NORTH OF THE STATE LINE IN WISCONSIN.
SUNDAY AFTERNOON`S LIKELY SEVERE CONVECTION OVER THE EASTERN PLAINS
WILL PROBABLY SPILL A FAIR AMOUNT OF DEBRIS CLOUDINESS AND POSSIBLY
SOME SHOWERS INTO THE AREA EARLY MONDAY...BUT AS THIS CONVECTION
MOVES AWAY FROM BETTER UPPER SUPPORT AND INTO MORE CAPPED
ENVIRONMENT TOWARD THE MS VALLEY WOULD EXPECT IT TO WEAKEN OR
DISSIPATE ALTOGETHER. STRONG SOUTHERLY WINDS AND 925MB TEMPS PROGGED
TO GET ABOVE 20C MONDAY COULD EASILY RESULT IN HIGHS IN THE UPPER
80S OVER MUCH OF THE CWA...THOUGH UNCERTAINTIES REGARDING EXTENT OF
DEBRIS FROM SUNDAY`S PLAINS CONVECTION AND LOWER GUIDANCE VALUES
HAVE PROMPTED ME TO BE MORE RESTRAINED IN MY BUMPING UP OVER TEMPS
MONDAY.
LOOKS LIKE STRONG TO SEVERE THUNDERSTORMS WILL DEVELOP TO OUR WEST
MONDAY AFTERNOON WITH STORMS MOVING INTO OUR AREA MONDAY NIGHT IN
ADVANCE OF APPROACHING STRONG COLD FRONT. GUIDANCE HAS CONTINUED TO
KEEP THE STRONGER WINDS ALOFT BEHIND THE COLD FRONT RESULTING IN
MORE MARGINAL SHEAR VALUES IN THE WARM SECTOR MONDAY. CERTAINLY
LOOKS TO BE ENOUGH SHEAR FOR AN ORGANIZED MULTIPLE EVENT TO
DEVELOP...BUT SOMEWHAT MARGINAL FOR A SUBSTANTIAL SEVERE THREAT
LOCALLY...ESPECIALLY WITH TIMING OF STORMS ARRIVING AFTER DARK
MONDAY NIGHT.
THE GFS IS REALLY AGGRESSIVE IN DEVELOPING POST FRONTAL
PRECIPITATION TUESDAY WITH OTHER GUIDANCE LESS GUNG-HO. OPTED TO
HANG ONTO CHANCE POPS TUESDAY MORNING AS A NOD TO THE GFS BUT
WOULDN`T BE SURPRISED IF MOST AREAS END UP DRY ALTOGETHER TUESDAY.
PRETTY BIG UNCERTAINTIES LINGER WEDNESDAY THROUGH FRIDAY IN THE
DETAILS OF ANY PRECIP CHANCES...THOUGH IT LOOKS LIKE THE MAJORITY OF
THE TIME FRAME WILL BE DRY DESPITE THE NEED TO MAINTAIN LOW CHANCES
POPS THROUGH THE PERIOD. HIGHER CONFIDENCE IN TEMPERATURES REMAINING
BELOW AVERAGE AS GUIDANCE AGREES ON COLD UPPER TROUGH SETTING UP
SHOP OVER THE AREA.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* TIMING OF WIND SHIFT TO EAST-SOUTHEAST WINDS LATE THIS
AFTERNOON/EARLY EVENING.
* WINDS AROUND DUE SOUTH AT TIMES ON SUNDAY.
* SMALL CHANCE FOR THUNDERSTORMS VERY EARLY SUNDAY MORNING...THEN
A BETTER CHANCE LATE SUNDAY AFTERNOON INTO THE EVENING.
//DISCUSSION...UPDATED 18Z...
HIGH PRESSURE OVER INDIANA AND EASTERN ILLINOIS WILL DEPART TO THE
SOUTHEAST LATE TONIGHT. IN THE MEANTIME...THE LIGHT WIND REGIME
FROM THE HIGH ALLOWED FOR A LAKE BREEZE TO DEVELOP. THIS LAKE
BREEZE HOWEVER HAS HAD DIFFICULTY ADVANCING INLAND AS MIXING AND
WEST TO SOUTHWEST GUSTS HAVE BEEN OBSERVED OVER INLAND PORTIONS OF
NORTHERN ILLINOIS...INCLUDING ORD AND MDW. THE EFFECTS OF THESE
WINDS HAVE ALREADY BEEN SEEN ON THE ORD TERMINAL DOPPLER WEATHER
RADAR...WITH THE LAKE BREEZE HAVING BECOME STATIONARY...EVEN
RETREATING SLIGHTLY. WITH LOSS OF MIXING LATE IN THE
AFTERNOON/EARLY EVE...THE LAKE BREEZE SHOULD PROPAGATE INLAND SOME
MORE. IN ADDITION...THE SYNOPTIC FLOW WILL TURN SOUTHEAST DURING
THE EARLY TO MID EVE AS THE HIGH PRESSURE MOVES AWAY. THE
SOUTHERLY WINDS WILL LIKELY PERSIST INTO SUNDAY AND INCREASE IN
SPEED.
THE OUTER EDGE OF WARM AIR ADVECTION AND ELEVATED INSTABILITY WILL
LIFT OVER THE REGION LATE TONIGHT/VERY EARLY SUNDAY MORNING.
ISOLATED/SCATTERED SHRA AND POSSIBLY A FEW TSRA ARE FAVORED TO
ACCOMPANY THIS FORCING. A BETTER CHANCE FOR THUNDER WILL ARRIVE
NEAR THE WARM FRONT LATER SUNDAY AFTERNOON INTO THE EVENING. SOME
OF THESE STORMS MAY BE DEEPER AND STRONGER.
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* LOW IN WIND SHIFT TIMING TO EAST SOUTHEAST AND MEDIUM THAT
SPEEDS WILL BE 8 KT OR LESS AFTER SHIFTING TO SOUTHEAST.
* MEDIUM IN WINDS ON SUNDAY.
* LOW IN ANY STORMS VERY EARLY SUNDAY MORNING AND THEN MEDIUM IN
ISOLATED/SCATTERED STORMS BY LATE SUNDAY AFTERNOON.
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...PERIODS OF SHRA/TSRA POSSIBLE.
MONDAY...PERIODS OF SHRA/TSRA POSSIBLE. GUSTY SOUTHWEST WINDS.
TUESDAY THROUGH FRIDAY...CHANCE OF SHRA.
MTF/KJB
&&
.MARINE...
201 AM CDT
A SURFACE RIDGE OF HIGH PRESSURE WILL MOVE ACROSS LAKE MICHIGAN
LATER TODAY...AND THIS WILL PROVIDE A PERIOD OF LIGHT AND VARIABLE
WINDS ACROSS THE SOUTHERN PORTION OF THE LAKE THIS AFTERNOON. LAKE
BREEZE INFLUENCES WILL LIKELY PRODUCE A LIGHT ONSHORE FLOW ACROSS THE
NEAR SHORE WATERS. THE WINDS WILL ULTIMATELY BECOME SOUTHERLY AGAIN
BY SUNDAY IN RESPONSE TO LOW PRESSURE TAKING SHAPE ACROSS THE
PLAINS. THIS AREA OF LOW PRESSURE IS EXPECTED TO SHIFT NORTHEASTWARD
ACROSS THE MID AND UPPER MISSISSIPPI VALLEY BY LATE MONDAY. AS THIS
OCCURS...AN ASSOCIATED WARM FRONT IS EXPECTED TO LIFT NORTHWARD UP
THE LAKE. A PERIOD OF STRONGER SOUTHERLY WINDS UP AROUND 20-25 KT
WILL LIKELY ENSUE IN THE WAKE OF THIS FRONTAL BOUNDARY...WITH AN
EAST-SOUTHEASTERLY WIND COMPONENT LIKELY NORTH OF THE BOUNDARY.
THESE SOUTHERLY WINDS WILL LIKELY CONTINUE THROUGH MONDAY
NIGHT...BEFORE A COLD FRONT SHIFTS ACROSS THE LAKE SOMETIME ON
TUESDAY...SHIFTING THE WINDS OUT OF THE WEST-NORTHWEST.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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Area Forecast Discussion
National Weather Service Lincoln IL
1232 PM CDT Sat May 10 2014
.DISCUSSION...
ISSUED 945 AM CDT Sat May 10 2014
14z/9am surface analysis shows stationary frontal boundary draped
across the far SE KILX CWA, generally south of a Robinson to Flora
line. Warm/moist airmass is still in place near and south of the
boundary where dewpoints are hovering in the middle 60s. Widely
scattered thunderstorms are ongoing south of the front near the
I-64 corridor: however, with a weak upper-level impulse currently
tracking out of Missouri into the Ohio River Valley, would not be
surprised to see a couple of cells develop further north near the
front. Latest RAP model hints at this through early afternoon
before upper wave exits into Indiana. As such, have decided to
include isolated thunder south of I-70. Further north, mostly
sunny and drier conditions are noted, with dewpoints only in the
40s. Another upper wave is evident on water vapor imagery over
Nebraska: however, this feature will lift northeastward and not
impact the weather across central Illinois today. End result will
be a warm/dry day with highs in the upper 70s and lower 80s. As
upper low over Washington/Oregon digs southward west of the
Rockies, downstream ridging will allow frontal boundary to lift
back northward tonight. Showers and thunderstorms will develop
along the boundary, but precip will hold off until evening. Zone
update has already been issued.
Barnes
&&
.AVIATION...
ISSUED 1232 PM CDT Sat May 10 2014
Dry/stable airmass will remain in place across central Illinois
this afternoon, resulting in mostly clear skies and light winds.
As a warm frontal boundary begins to lift back northward tonight,
scattered showers and thunderstorms will develop and track through
the area. Timing of convection remains in question, as stable
surface-based layer will slow eastward progression of any storms
that develop west of the Mississippi River this afternoon. Most
high-res model guidance suggests convective development
along/north of the warm front across western Missouri over the
next couple of hours, with storms tracking E/SE along the
boundary into south-central Illinois by evening. Trajectory of
storms may keep them south of the central Illinois terminals until
later in the evening when front lifts further northward and
low-level jet strengthens across the area. Due to low confidence
concerning timing and areal coverage, have opted to only go with
VCTS in the TAFs at this time. Will introduce VCTS at KSPI
earliest by 03z, then further northeast at KCMI by 07z. Front will
lift north of the area by Sunday morning, taking best focus for
additional convection into northern Illinois. Light SE winds this
afternoon will become southerly and will increase into the 10 to
15kt range behind the warm front on Sunday.
Barnes
&&
.PREV DISCUSSION...
ISSUED 330 AM CDT Sat May 10 2014
SHORT TERM...Today through Tuesday
A nice day in store for central IL today as skies become partly to
mostly sunny and highs in the upper 70s to around 80F. A frontal
boundary lingers in far southeast CWA early this morning and have
isolated showers and thunderstorms possible near Lawrenceville
until mid morning until front pushes slowly se of there. More
active weather pattern takes shape from tonight through the middle
of next week, with daily chances of showers and thunderstorms. SPC
has areas sw of Canton to Lincoln to Effingham in a slight risk of
severe storms tonight as warm front lift north with increasing
chances of showers and thunderstorms from west to east during the
night. Areas from I-72 north are in a slight risk of severe on
Sunday afternoon into Sunday night. And areas from I-55 west are
in a slight risk of severe storms again later Monday afternoon and
Monday night as a cold front moves east across IL Monday night.
Have lowered chances of showers and thunderstorms Sunday night and
Monday morning especially southern counties as best convection
chances shift north with warm front. Warm weather in store through
Monday with highs Sunday/Monday in the low to mid 80s. Monday has
potential to be the warmest day with 850 mb temps elevating to
near 20C and this depends on how much sunshine we see. Will have
breezy south southwest winds Monday and increase wind speeds then.
On Tue kept likely chances of showers and isolated thunderstorms
over eastern IL closer to departing cold front while chance of
showers west of I-57 Tue. Highs Tue range from mid 60s over IL
river valley to mid 70s near the Wabash River.
LONG TERM...Tuesday night through Saturday
Unsettled weather pattern looks to continue at least Tue night and
Wed as strong upper level trof shifts east into IL and ECMWF model
even shows surface low pressure lifting ne and passing se of
central IL Wed and bringing widespread showers to the area. If
this pans out may need to increase pops further on Wed and have
cooler temps. Large upper level trof over the Midwest and Great
Lakes region continues for 2nd half of next week keeping temps
below normal along with lingering chances of light rain showers.
07
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1056 AM CDT SAT MAY 10 2014
.DISCUSSION...
252 AM CDT
PRIMARY FORECAST CHALLENGE THIS MORNING REMAINS THE CONVECTIVE
POTENTIAL STARTING TONIGHT AND CONTINUING AT TIMES THROUGH MONDAY
NIGHT. SECONDARY CONCERNS INCLUDE TEMPERATURES SUNDAY INTO MONDAY
AND THEN PRECIP CHANCES NEXT WEEK.
HIGH PRESSURE OVER THE REGION TODAY SHOULD RESULT IN A PRETTY NICE
DAY OVERALL. SLUG OF HIGH CLOUDINESS OVER MISSOURI IS ASSOCIATED
WITH A SHORTWAVE ALOFT...MUCH MORE DEFINED AT 250MB THAN AT 500MB
WITH VERY LITTLE REFLECTION AT 700MB. DRY LOW LEVELS AND ABSENCE OF
FORCING SHOULD KEEP THIS ONLY A HIGH CLOUD PRODUCER AND MAINLY THIS
MORNING. LIGHT WIND REGIME SHOULD ALLOW LAKE BREEZE TO FORM BY EARLY
AFTERNOON WITH FALLING TEMPS NEAR THE LAKE THIS AFTERNOON...BUT
FAIRLY MILD CONDITIONS AWAY FROM THE LAKE.
TONIGHT LOW LEVEL JET SHOULD RESULT IN STRENGTHENING LOW LEVEL
THETA-E ADVECTION AND LIKELY THE DEVELOPING OF SHOWERS AND
THUNDERSTORMS OVER MISSOURI THIS EVENING. THIS ACTIVITY IS EXPECTED
TO PUSH EAST INTO ILLINOIS LATE TONIGHT...HOWEVER GUIDANCE IS
INCREASINGLY SUGGESTING THAT THE STRONGEST MOISTURE CONVERGENCE WILL
REMAIN FARTHER SOUTH ACROSS CENTRAL ILLINOIS WITH FAR LESSER SUPPORT
FROM PRECIP FARTHER NORTH. HAVE DECREASED POPS CONSIDERABLY OVER
NORTHERN 2/3RD OF CWA...MAINTAINING CHANCE POPS MOSTLY FOR
CONTINUITY SAKE AS IT LOOKS MORE AND MORE LIKELY THAT IT COULD STAY
DRY ALTOGETHER NORTH OF I-80. FAR SOUTHERN CWA STANDS A BETTER
CHANCE OF SEEING SOME OF THIS CONVECTION AND HAVE MAINTAINED HIGHER
POPS THERE.
SUNDAY SHOULD SEE DEVELOPING SOUTHERLY FLOW AS CYCLOGENESIS TAKES
PLACE OVER THE PLAINS WITH STRENGTHENING WARM AND MOIST ADVECTION
INTO THE AREA. DOES APPEAR AS THOUGH A SOMEWHAT ILL DEFINED WARM
FRONT WILL DEVELOP AND LIFT NORTH ACROSS THE CWA SUNDAY BUT
OTHERWISE SYNOPTIC SCALE FORCING LOOKS SOMEWHAT
NEBULOUS...PARTICULARLY IN LIGHT IN STRONG HEIGHT RISES DOWNSTREAM
OF THE AMPLIFYING TROUGH TO OUR WEST. CERTAINLY PLAUSIBLE THAT
REMNANT MCV FROM TODAY`S CONVECTION OVER THE PLAINS OR FORCING
ALONG THE WEAK WARM FRONT COULD BE ENOUGH TO KICK OF THUNDERSTORMS
SUNDAY AFTERNOON...BUT OVERALL SYNOPTIC PATTERN WOULD ARGUE FOR
LARGELY A RAIN-FREE DAY ACROSS THE CWA AND HAVE ATTEMPTED TO SCALE
BACK POPS SOME. WORTH NOTING HOWEVER...THAT MODERATE INSTABILITY
SHOULD DEVELOP WITH THE INCREASINGLY WARM/HUMID AIRMASS AND WITH
STILL RESPECTABLE VALUES OF DEEP LAYER SHEAR THREAT DOES EXISTS FOR
ANY CONVECTION THAT DOES DEVELOP SUNDAY AFTERNOON TO BE SEVERE. NOT
TO MENTION THAT ILLINOIS WARM FRONTS SEEM TO LIKE TO PRODUCE
"SURPRISES" THIS TIME OF YEAR.
SOUTHERLY WINDS ON SUNDAY LOOK LIGHT ENOUGH FOR AT LEAST AN ILLINOIS
SHORE LAKE BREEZE TO DEVELOP IN THE AFTERNOON...PARTICULARLY IF WARM
FRONT BECOMES BETTER DEFINED AND WINDS MORE BACKED AHEAD OF IT.
ASSUMING THIS SCENARIO PANS OUT DID KEEP LAKE COOLING IN THE GRIDS
SUNDAY WITH FAIRLY WARM TEMPERATURES EXPECTED ELSEWHERE. BY SUNDAY
NIGHT THE MAJORITY OF GUIDANCE AGREES THAT THE WARM FRONT WILL
BECOME BETTER DEFINED TO OUR NORTH OVER WISCONSIN WITH FOCUS FOR
POTENTIALLY SIGNIFICANT CONVECTIVE EVENT NORTH OF THE BORDER WITH
OUR CWA JUST UNSEASONABLY WARM AND STEAMY WITH LOWS STRUGGLING TO
DIP BELOW 70 DEGREES AS DEWPOINTS CLIMB WELL INTO THE 60S AND
MODERATELY STRONG WINDS THROUGH THE NIGHT. GFS IS THE ODD MAN OUT
KEEPING WARM FRONT AND SIGNIFICANT CONVECTION FARTHER SOUTH INTO OUR
CWA. HAVE TRENDED POPS DOWN SUNDAY NIGHT...ESPECIALLY SOUTHERN
CWA...BUT RELUCTANT TO GO TOO LOW GIVEN GFS SOLUTION AND POSSIBILITY
THAT EVEN IF OTHER MODELS VERIFY OUTFLOW COULD PUSH SOUTH AND ALLOW
CONVECTION TO PROPAGATE INTO OUR FAR NORTHERN CWA. UNUSUALLY HIGH
PWATS AND SLOW MOVING NATURE OF WARM FRONT RAISE CONCERNS FOR HEAVY
RAINFALL AND FLASH FLOODING...THOUGH THANKFULLY THAT APPEARS TO BE
MORE OF A THREAT NORTH OF THE STATE LINE IN WISCONSIN.
SUNDAY AFTERNOON`S LIKELY SEVERE CONVECTION OVER THE EASTERN PLAINS
WILL PROBABLY SPILL A FAIR AMOUNT OF DEBRIS CLOUDINESS AND POSSIBLY
SOME SHOWERS INTO THE AREA EARLY MONDAY...BUT AS THIS CONVECTION
MOVES AWAY FROM BETTER UPPER SUPPORT AND INTO MORE CAPPED
ENVIRONMENT TOWARD THE MS VALLEY WOULD EXPECT IT TO WEAKEN OR
DISSIPATE ALTOGETHER. STRONG SOUTHERLY WINDS AND 925MB TEMPS PROGGED
TO GET ABOVE 20C MONDAY COULD EASILY RESULT IN HIGHS IN THE UPPER
80S OVER MUCH OF THE CWA...THOUGH UNCERTAINTIES REGARDING EXTENT OF
DEBRIS FROM SUNDAY`S PLAINS CONVECTION AND LOWER GUIDANCE VALUES
HAVE PROMPTED ME TO BE MORE RESTRAINED IN MY BUMPING UP OVER TEMPS
MONDAY.
LOOKS LIKE STRONG TO SEVERE THUNDERSTORMS WILL DEVELOP TO OUR WEST
MONDAY AFTERNOON WITH STORMS MOVING INTO OUR AREA MONDAY NIGHT IN
ADVANCE OF APPROACHING STRONG COLD FRONT. GUIDANCE HAS CONTINUED TO
KEEP THE STRONGER WINDS ALOFT BEHIND THE COLD FRONT RESULTING IN
MORE MARGINAL SHEAR VALUES IN THE WARM SECTOR MONDAY. CERTAINLY
LOOKS TO BE ENOUGH SHEAR FOR AN ORGANIZED MULTIPLE EVENT TO
DEVELOP...BUT SOMEWHAT MARGINAL FOR A SUBSTANTIAL SEVERE THREAT
LOCALLY...ESPECIALLY WITH TIMING OF STORMS ARRIVING AFTER DARK
MONDAY NIGHT.
THE GFS IS REALLY AGGRESSIVE IN DEVELOPING POST FRONTAL
PRECIPITATION TUESDAY WITH OTHER GUIDANCE LESS GUNG-HO. OPTED TO
HANG ONTO CHANCE POPS TUESDAY MORNING AS A NOD TO THE GFS BUT
WOULDN`T BE SURPRISED IF MOST AREAS END UP DRY ALTOGETHER TUESDAY.
PRETTY BIG UNCERTAINTIES LINGER WEDNESDAY THROUGH FRIDAY IN THE
DETAILS OF ANY PRECIP CHANCES...THOUGH IT LOOKS LIKE THE MAJORITY OF
THE TIME FRAME WILL BE DRY DESPITE THE NEED TO MAINTAIN LOW CHANCES
POPS THROUGH THE PERIOD. HIGHER CONFIDENCE IN TEMPERATURES REMAINING
BELOW AVERAGE AS GUIDANCE AGREES ON COLD UPPER TROUGH SETTING UP
SHOP OVER THE AREA.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* TIMING OF LAKE BREEZE AND WIND SHIFT TO EAST-SOUTHEAST WINDS LATE
THIS AFTERNOON/EARLY EVENING.
* INCREASING CHANCES OF THUNDERSTORMS INTO SUNDAY.
MTF/KJB
//DISCUSSION...UPDATED 12Z...
OVERALL A FAIRLY QUIET WEATHER DAY APPEARS IN STORE FOR THE AREA
TODAY. THE ONLY MINOR CONCERNS WILL BE THE POTENTIAL FOR A LAKE
BREEZE TO SHIFT THE WINDS EASTERLY VERY LATE THIS AFTERNOON AT THE
EASTERN TERMINALS...AND A SMALL CHANCE FOR THUNDERSTORMS LATE
TONIGHT INTO EARLY SUNDAY.
A SURFACE RIDGE OF HIGH PRESSURE...CURRENTLY IN PLACE ACROSS THE
REGION...WILL CONTINUE TO SUPPORT A FAIRLY LIGHT SYNOPTIC WIND
FIELD ACROSS THE AREA TODAY. THIS SHOULD PROMOTE A LAKE BREEZE TO
DEVELOP ALONG THE NORTHEASTERN ILLINOIS SHORELINE LATER TODAY. THE
EXACT TIMING OF THIS BOUNDARY...AND THE ASSOCIATED WIND
SHIFT...REACHING KORD AND KMDW REMAINS A BIT UNCERTAIN.
HOWEVER...IT APPEARS THAT THIS WIND SHIFT SHOULD OCCUR EITHER VERY
LATE THIS AFTERNOON...AFTER 22 UTC...OR EARLY THIS EVENING AS THE
LARGELY SCALE WIND PATTERN BEGINS TO FAVOR AN EAST-SOUTHEASTERLY
WIND COMPONENT. WIND SPEEDS WITH THE WIND SHIFT LOOK TO REMAIN AT
OR UNDER 10 KT.
ANOTHER STORM SYSTEM WILL BE TAKING SHAPE ACROSS THE PLAINS STATES
LATE TODAY AND TONIGHT. THIS SYSTEM WILL LIKELY BE THE CULPRIT FOR
ANOTHER PERIOD OR TWO OF THUNDERSTORMS ACROSS THE AREA LATER IN THE
WEEKEND THROUGH EARLY NEXT WEEK. SOME OF THESE SHOWERS AND
THUNDERSTORMS COULD ENTER THE PICTURE AS EARLY AS LATER TONIGHT INTO
EARLY SUNDAY. HOWEVER...IT APPEARS THAT THE BEST CHANCES FOR
CONVECTIVE ACTIVITY TONIGHT WILL REMAIN SOUTH OF THE TERMINALS.
BETTER CHANCES FOR CONVECTIVE ACTIVITY APPEAR TO BE IN STORE
ACROSS NORTHERN ILLINOIS LATER SUNDAY AS A WARM FRONT LIFTS ACROSS
THE AREA. THIS THREAT IS CURRENTLY BEYOND THE 30 HOUR KORD
TAF.
THE ONLY CHANGE TO THE EXTEND PORTION OF THE TAFS WAS TO ADD
A PROB 30 GROUP FOR -SHRA LATE TONIGHT INTO EARLY SUNDAY TO COVER
THE LOW THREAT FOR SOME ACTIVITY IMPACTING NORTHERN ILLINOIS.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM IN TIMING OF SHIFT TO EAST-SOUTHEAST THIS
AFTERNOON/EVENING. LOW-MEDIUM IN SPEEDS BEING 8 KT OR LESS
BEHIND WIND SHIFT.
* LOW ON CONVECTIVE ACTIVITY IMPACTING THE TERMINALS LATE TONIGHT.
MTF/KJB
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...PERIODS OF SHRA/TSRA POSSIBLE.
MONDAY...PERIODS OF SHRA/TSRA POSSIBLE. GUSTY SOUTHWEST WINDS.
TUESDAY THROUGH FRIDAY...CHANCE OF SHRA.
KJB
&&
.MARINE...
201 AM CDT
A SURFACE RIDGE OF HIGH PRESSURE WILL MOVE ACROSS LAKE MICHIGAN
LATER TODAY...AND THIS WILL PROVIDE A PERIOD OF LIGHT AND VARIABLE
WINDS ACROSS THE SOUTHERN PORTION OF THE LAKE THIS AFTERNOON. LAKE
BREEZE INFLUENCES WILL LIKELY PRODUCE A LIGHT ONSHORE FLOW ACROSS THE
NEAR SHORE WATERS. THE WINDS WILL ULTIMATELY BECOME SOUTHERLY AGAIN
BY SUNDAY IN RESPONSE TO LOW PRESSURE TAKING SHAPE ACROSS THE
PLAINS. THIS AREA OF LOW PRESSURE IS EXPECTED TO SHIFT NORTHEASTWARD
ACROSS THE MID AND UPPER MISSISSIPPI VALLEY BY LATE MONDAY. AS THIS
OCCURS...AN ASSOCIATED WARM FRONT IS EXPECTED TO LIFT NORTHWARD UP
THE LAKE. A PERIOD OF STRONGER SOUTHERLY WINDS UP AROUND 20-25 KT
WILL LIKELY ENSUE IN THE WAKE OF THIS FRONTAL BOUNDARY...WITH AN
EAST-SOUTHEASTERLY WIND COMPONENT LIKELY NORTH OF THE BOUNDARY.
THESE SOUTHERLY WINDS WILL LIKELY CONTINUE THROUGH MONDAY
NIGHT...BEFORE A COLD FRONT SHIFTS ACROSS THE LAKE SOMETIME ON
TUESDAY...SHIFTING THE WINDS OUT OF THE WEST-NORTHWEST.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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Area Forecast Discussion
National Weather Service Lincoln IL
945 AM CDT Sat May 10 2014
.DISCUSSION...
ISSUED 945 AM CDT Sat May 10 2014
14z/9am surface analysis shows stationary frontal boundary draped
across the far SE KILX CWA, generally south of a Robinson to Flora
line. Warm/moist airmass is still in place near and south of the
boundary where dewpoints are hovering in the middle 60s. Widely
scattered thunderstorms are ongoing south of the front near the
I-64 corridor: however, with a weak upper-level impulse currently
tracking out of Missouri into the Ohio River Valley, would not be
surprised to see a couple of cells develop further north near the
front. Latest RAP model hints at this through early afternoon
before upper wave exits into Indiana. As such, have decided to
include isolated thunder south of I-70. Further north, mostly
sunny and drier conditions are noted, with dewpoints only in the
40s. Another upper wave is evident on water vapor imagery over
Nebraska: however, this feature will lift northeastward and not
impact the weather across central Illinois today. End result will
be a warm/dry day with highs in the upper 70s and lower 80s. As
upper low over Washington/Oregon digs southward west of the
Rockies, downstream ridging will allow frontal boundary to lift
back northward tonight. Showers and thunderstorms will develop
along the boundary, but precip will hold off until evening. Zone
update has already been issued.
Barnes
&&
.AVIATION...
ISSUED 658 AM CDT Sat May 10 2014
The stationary front across southeast IL will linger in place south
of the terminal sites today, with BKN high clouds north of the
front in central Illinois through the day. Winds will generally
be less than 10 kt from the east-southeast until afternoon, when
wind speeds increase between 10-14kt for the western terminals.
Storm chances will be tied to the northward advance of the
front as a warm front tonight. Storms are forecast to develop
across Missouri this evening and advance from west to east across
the area tonight. It appears that storms could reach as far east as
PIA to SPI by 02z. The NCEP 4km WRF output has the initial wave of
storms in a 4 hour window, so tempo`s for MVFR vis in TSRA were
included at all TAF sites for late evening to just after midnight.
Storm chances could linger through morning under VCTS conditions,
but SPI and PIA could see a break develop by 10z.
Shimon
&&
.PREV DISCUSSION...
ISSUED 330 AM CDT Sat May 10 2014
SHORT TERM...Today through Tuesday
A nice day in store for central IL today as skies become partly to
mostly sunny and highs in the upper 70s to around 80F. A frontal
boundary lingers in far southeast CWA early this morning and have
isolated showers and thunderstorms possible near Lawrenceville
until mid morning until front pushes slowly se of there. More
active weather pattern takes shape from tonight through the middle
of next week, with daily chances of showers and thunderstorms. SPC
has areas sw of Canton to Lincoln to Effingham in a slight risk of
severe storms tonight as warm front lift north with increasing
chances of showers and thunderstorms from west to east during the
night. Areas from I-72 north are in a slight risk of severe on
Sunday afternoon into Sunday night. And areas from I-55 west are
in a slight risk of severe storms again later Monday afternoon and
Monday night as a cold front moves east across IL Monday night.
Have lowered chances of showers and thunderstorms Sunday night and
Monday morning especially southern counties as best convection
chances shift north with warm front. Warm weather in store through
Monday with highs Sunday/Monday in the low to mid 80s. Monday has
potential to be the warmest day with 850 mb temps elevating to
near 20C and this depends on how much sunshine we see. Will have
breezy south southwest winds Monday and increase wind speeds then.
On Tue kept likely chances of showers and isolated thunderstorms
over eastern IL closer to departing cold front while chance of
showers west of I-57 Tue. Highs Tue range from mid 60s over IL
river valley to mid 70s near the Wabash River.
LONG TERM...Tuesday night through Saturday
Unsettled weather pattern looks to continue at least Tue night and
Wed as strong upper level trof shifts east into IL and ECMWF model
even shows surface low pressure lifting ne and passing se of
central IL Wed and bringing widespread showers to the area. If
this pans out may need to increase pops further on Wed and have
cooler temps. Large upper level trof over the Midwest and Great
Lakes region continues for 2nd half of next week keeping temps
below normal along with lingering chances of light rain showers.
07
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
216 AM EDT SAT MAY 10 2014
.UPDATE...
THE LONG TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 251 PM EDT FRI MAY 9 2014
A FEW THUNDERSTORMS REMAIN POSSIBLE OVERNIGHT AS A COLD FRONT
MOVES ACROSS CENTRAL INDIANA AFTER A MAINLY DRY SATURDAY...ANOTHER
SYSTEM WILL RESULT IN PROLONGED THUNDERSTORM CHANCES FROM
SATURDAY NIGHT THROUGH WEDNESDAY WITH LINGERING SHOWERS AFTER
THAT.
TEMPERATURES WILL REMAIN ABOVE NORMAL IN THE 70S AND 80S UNTIL A
MIDWEEK COLD FRONT MOVES THROUGH NEXT WEEK. THEN...TEMPERATURES
WILL BECOME BELOW NORMAL IN THE 60S AND CONTINUE THAT WAY THROUGH
THE LATE WEEK.
&&
.NEAR TERM /OVERNIGHT/...
ISSUED AT 1017 PM EDT FRI MAY 9 2014
CONVECTION AHEAD OF THE FRONT HAS FINALLY MOVED OFF TO THE
NORTHEAST WITH THE WEAKENING WAVE ALOFT. CLOUDS REMAIN ACROSS MUCH
OF THE FORECAST AREA WITH SOME CLEARING INTO THE FAR NORTHWEST
COUNTIES AS SOME SUBSIDENCE HAS WORKED IN BEHIND THE UPPER WAVE.
TEMPS REMAINED LARGELY IN THE 60S AS OF 02Z.
WHILE THE BULK OF THE CONVECTION HAS FINISHED FOR THE NIGHT...
CANNOT ENTIRELY RULE OUT ANY ADDITIONAL ACTIVITY WITH THE FRONT
TAKING MOST OF THE NIGHT TO SAG INTO SOUTHERN COUNTIES. 00Z NAM
AND CURRENT HRRR HINT AT SOME REDEVELOPMENT OVERNIGHT...FOCUSED
SOUTH OF INTERSTATE 70 AND MAINLY AFTER 07-08Z. HAVE ADJUSTED POPS
DOWN TO 20-30 FOR ALL BUT THE NORTHWEST COUNTIES FOR THE REMAINDER
OF THE NIGHT. ADJUSTED LOW TEMPS UP A DEGREE OR TWO IN THE SOUTH
WITH THE FRONT NOT MAKING IT INTO SOUTHERN COUNTIES UNTIL LATE.
ZONE AND GRID UPDATES OUT.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY/...
ISSUED AT 251 PM EDT FRI MAY 9 2014
SHOWER OR THUNDERSTORM CHANCES WILL BE THE MAIN CONCERN FOR THE
SHORT TERM. THE 00Z ECMWF AND ITS ENSEMBLES HAVE BEEN MUCH MORE
CONSISTENT WITH THE SHORT TERM SYNOPTIC PATTERN. A COLD FRONT WILL
STALL NEAR OUR SOUTHERN BORDER ON SATURDAY MORNING AND RETURN NORTH
AS A WARM FRONT SATURDAY NIGHT AND SUNDAY IN RESPONSE TO A SURFACE
LOW NEAR THE OKLAHOMA PANHANDLE SPAWNED FROM AN UPSTREAM UPPER LOW
NEAR THE FOUR CORNERS REGION. THUS...WITH THE FRONT NEARBY SATURDAY
MORNING ALONG WITH LINGERING INSTABILITY...WILL HOLD ON TO SMALL
THUNDERSTORM CHANCES SATURDAY MORNING AND BRING BACK HIGH CHANCES BY
SATURDAY NIGHT AS THE WARM FRONT APPROACHES. THE AREA SHOULD BE IN
THE WARM SECTOR AFTER THAT AS SURFACE LOW LIFTS NORTHEAST TO THE
UPPER MIDWEST MONDAY. SO...KEPT POPS SUNDAY...ALBEIT LOW POPS WITH
AN ASSOCIATED COLD FRONT WELL TO THE WEST...ACROSS THE PLAINS.
BLEND OF COOLER 12Z NAM AND WARMER 12Z GFS LOOKS OK FOR THE SHORT
TERM AND MATCHES WELL WITH 12Z ALLBLEND. SHOULD CONTINUE TO SEE
ABOVE NORMAL TEMPERATURES WITH AFTERNOON HIGHS IN MID TO UPPER 70S
SATURDAY AND UPPER 70S AND LOWER 80S SUNDAY AND MONDAY.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
ISSUED AT 207 AM EDT SAT MAY 10 2014
CONFIDENCE IS GROWING FOR A RAIN EVENING SOMETIME ON TUESDAY INTO
WEDNESDAY HOWEVER CONFIDENCE IN TIMING REMAINS LOW. GFS AND ECMWF
CONTINUE TO SUGGEST A WARM AND MOIST AIR MASS IN PLACE OVER
INDIANA AHEAD OF AN APPROACHING COLD FRONT AND UPPER WAVE. FARTHER
DOWNSTREAM A BLOCKING RIDGE WAS IN PLACE. THE GFS IS QUICKER WITH
THE PROGRESSION OF THE FRONT THAN THE ECMWF AND WITH THE BLOCKING
RIDGE IN PLACE TO THE EAST...A SLOWER PROGRESSION IS PREFERRED.
NONETHELESS...PRECIP LOOKS LIKE A GOOD BET IN THE MIDDLE OF NEXT
WEEK AS THIS SYSTEM PASSES.
IN THE WAKE OF THAT FRONTAL PASSAGE...BOTH THE GFS AND ECMWF KEEP
BROAD UPPER CYCLONIC FLOW ACROSS THE AREA...HOWEVER MOISTURE WILL
REMAIN LIMITED IN THE LOWER LEVELS. WILL TREND POPS AND TEMPS
LOWERS AMID A COOLER AND DRIER FLOW INTO THE AREA FOR LATE NEXT WEEK.
&&
.AVIATION /DISCUSSION FOR 100600Z TAF UPDATE/...
ISSUED AT 1208 PM EDT FRI MAY 9 2014
SHORT TERM MODELS SHOWING VARIABILITY ABOUT RAIN/THUNDER DURING THE
OVERNIGHT...BUT A COUPLE ARE SHOWING THE FRONT STALLING OUT AND RAIN
OR POSSIBLY THUNDER ALONG AN EAST-WEST AREA THAT WOULD INCLUDE ALL
SITES BUT KLAF. PUT A TEMPO SHOWER IN AT KHUF AND KIND AND PUT A
PREVAILING SHOWER IN AT KBMG. GUIDANCE INDICATES SOME MVFR
CEILINGS/VISIBILITIES WITH THIS SO INCLUDED THEM AS WELL. ANY
RESTRICTIONS THAT DO DEVELOP SHOULD BE GONE BY AROUND 13Z AND THEN
VFR FOR THE DAY. WINDS WILL DROP OFF OVER THE NEXT COUPLE OF HOURS
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MK/RYAN
NEAR TERM...RYAN
SHORT TERM...MK
LONG TERM....PUMA
AVIATION...CP/JP
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AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1208 PM EDT FRI MAY 9 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 251 PM EDT FRI MAY 9 2014
A FEW THUNDERSTORMS REMAIN POSSIBLE OVERNIGHT AS A COLD FRONT
MOVES ACROSS CENTRAL INDIANA AFTER A MAINLY DRY SATURDAY...ANOTHER
SYSTEM WILL RESULT IN PROLONGED THUNDERSTORM CHANCES FROM
SATURDAY NIGHT THROUGH WEDNESDAY WITH LINGERING SHOWERS AFTER
THAT.
TEMPERATURES WILL REMAIN ABOVE NORMAL IN THE 70S AND 80S UNTIL A
MIDWEEK COLD FRONT MOVES THROUGH NEXT WEEK. THEN...TEMPERATURES
WILL BECOME BELOW NORMAL IN THE 60S AND CONTINUE THAT WAY THROUGH
THE LATE WEEK.
&&
.NEAR TERM /OVERNIGHT/...
ISSUED AT 1017 PM EDT FRI MAY 9 2014
CONVECTION AHEAD OF THE FRONT HAS FINALLY MOVED OFF TO THE
NORTHEAST WITH THE WEAKENING WAVE ALOFT. CLOUDS REMAIN ACROSS MUCH
OF THE FORECAST AREA WITH SOME CLEARING INTO THE FAR NORTHWEST
COUNTIES AS SOME SUBSIDENCE HAS WORKED IN BEHIND THE UPPER WAVE.
TEMPS REMAINED LARGELY IN THE 60S AS OF 02Z.
WHILE THE BULK OF THE CONVECTION HAS FINISHED FOR THE NIGHT...
CANNOT ENTIRELY RULE OUT ANY ADDITIONAL ACTIVITY WITH THE FRONT
TAKING MOST OF THE NIGHT TO SAG INTO SOUTHERN COUNTIES. 00Z NAM
AND CURRENT HRRR HINT AT SOME REDEVELOPMENT OVERNIGHT...FOCUSED
SOUTH OF INTERSTATE 70 AND MAINLY AFTER 07-08Z. HAVE ADJUSTED POPS
DOWN TO 20-30 FOR ALL BUT THE NORTHWEST COUNTIES FOR THE REMAINDER
OF THE NIGHT. ADJUSTED LOW TEMPS UP A DEGREE OR TWO IN THE SOUTH
WITH THE FRONT NOT MAKING IT INTO SOUTHERN COUNTIES UNTIL LATE.
ZONE AND GRID UPDATES OUT.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY/...
ISSUED AT 251 PM EDT FRI MAY 9 2014
SHOWER OR THUNDERSTORM CHANCES WILL BE THE MAIN CONCERN FOR THE
SHORT TERM. THE 00Z ECMWF AND ITS ENSEMBLES HAVE BEEN MUCH MORE
CONSISTENT WITH THE SHORT TERM SYNOPTIC PATTERN. A COLD FRONT WILL
STALL NEAR OUR SOUTHERN BORDER ON SATURDAY MORNING AND RETURN NORTH
AS A WARM FRONT SATURDAY NIGHT AND SUNDAY IN RESPONSE TO A SURFACE
LOW NEAR THE OKLAHOMA PANHANDLE SPAWNED FROM AN UPSTREAM UPPER LOW
NEAR THE FOUR CORNERS REGION. THUS...WITH THE FRONT NEARBY SATURDAY
MORNING ALONG WITH LINGERING INSTABILITY...WILL HOLD ON TO SMALL
THUNDERSTORM CHANCES SATURDAY MORNING AND BRING BACK HIGH CHANCES BY
SATURDAY NIGHT AS THE WARM FRONT APPROACHES. THE AREA SHOULD BE IN
THE WARM SECTOR AFTER THAT AS SURFACE LOW LIFTS NORTHEAST TO THE
UPPER MIDWEST MONDAY. SO...KEPT POPS SUNDAY...ALBEIT LOW POPS WITH
AN ASSOCIATED COLD FRONT WELL TO THE WEST...ACROSS THE PLAINS.
BLEND OF COOLER 12Z NAM AND WARMER 12Z GFS LOOKS OK FOR THE SHORT
TERM AND MATCHES WELL WITH 12Z ALLBLEND. SHOULD CONTINUE TO SEE
ABOVE NORMAL TEMPERATURES WITH AFTERNOON HIGHS IN MID TO UPPER 70S
SATURDAY AND UPPER 70S AND LOWER 80S SUNDAY AND MONDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY NIGHT/...
ISSUED AT 251 PM EDT FRI MAY 9 2014
A COLD FRONT IS PROGGED TO AFFECT CENTRAL INDIANA AT THE BEGINNING
OF THE EXTENDED PERIOD. GFS AND EURO ARE IN GOOD AGREEMENT WITH
TIMING...AND LATEST INITIALIZATION IS SHOWING LIKELY POPS FOR
TUESDAY. AFTER A BRIEF DRY SLOT ON WEDNESDAY...MODELS HAVE A BROAD
AREA OF LOW PRESSURE ALOFT EXTENDING FROM ONTARIO INTO THE
MISSISSIPPI VALLEY. THIS SHOULD GENERATE ENOUGH LIFT FOR ADDITIONAL
SHOWERS AND THUNDERSTORMS THROUGH THURSDAY NIGHT. AFTER THAT...A
LARGE RIDGE OF SURFACE HIGH PRESSURE IS EXPECTED TO MOVE INTO THE
CENTRAL PLAINS...BUT TIMING BECOMES INCONSISTENT IN MODELS AT THAT
POINT. THE EURO BRINGS DRIER CONDITIONS INTO THE FORECAST AREA
EARLIER THAN THE GFS. MEANWHILE...THE LATEST INITIALIZATION FAVORS
SLIGHT CHANCE POPS THROUGH THE REMAINDER OF EXTENDED PERIOD. FOR
NOW...WILL KEEP INITIALIZATION FORECAST UNTIL MODELS BECOME MORE
CONSISTENT. TEMPERATURES WILL GRADUALLY DECREASE BELOW NORMAL
THROUGH THE COURSE OF THE EXTENDED PERIOD WITH HIGHS ONLY TOPPING
OFF IN THE 60S AND LOWS DIPPING INTO THE 40S.
&&
.AVIATION /DISCUSSION FOR 100600Z TAF UPDATE/...
ISSUED AT 1208 PM EDT FRI MAY 9 2014
SHORT TERM MODELS SHOWING VARIABILITY ABOUT RAIN/THUNDER DURING THE
OVERNIGHT...BUT A COUPLE ARE SHOWING THE FRONT STALLING OUT AND RAIN
OR POSSIBLY THUNDER ALONG AN EAST-WEST AREA THAT WOULD INCLUDE ALL
SITES BUT KLAF. PUT A TEMPO SHOWER IN AT KHUF AND KIND AND PUT A
PREVAILING SHOWER IN AT KBMG. GUIDANCE INDICATES SOME MVFR
CEILINGS/VISIBILITIES WITH THIS SO INCLUDED THEM AS WELL. ANY
RESTRICTIONS THAT DO DEVELOP SHOULD BE GONE BY AROUND 13Z AND THEN
VFR FOR THE DAY. WINDS WILL DROP OFF OVER THE NEXT COUPLE OF HOURS
AND THEN SHOULD REMAIN FAIRLY LIGHT THROUGH SATURDAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...MK/RYAN
NEAR TERM...RYAN
SHORT TERM...MK
LONG TERM....TDUD
AVIATION...CP/JP
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AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
645 PM CDT SUN MAY 11 2014
.UPDATE...
ISSUED AT 635 PM CDT SUN MAY 11 2014
DATA TRENDS THE PAST 3 HOURS NOW INDICATE THERE WILL BE A BREAK IN
ACTIVITY DURING THE EVENING HOURS.
THE CURRENT THUNDERSTORM COMPLEX IS SLOWLY MOVING INTO NORTHEAST
ILLINOIS BUT BOUNDARIES LEFT OVER WILL ALLOW STORMS TO PERSIST
OVER THE SOUTHERN PARTS OF THE AREA FOR THE NEXT SEVERAL HOURS.
AN EFFECTIVE BOUNDARY IS EVIDENT ACROSS SOUTHERN IOWA WITH NO
CELLULAR CLOUDS NORTH OF THE BOUNDARY AND DIURNAL CLOUDS ACROSS
MISSOURI. THIS BOUNDARY MAY PROVIDE A FOCUS FOR ADDITIONAL
ISOLATED TO SCATTERED STORMS THROUGH SUNSET.
DATA STILL SUGGESTS THE STORMS IN NEBRASKA WILL EVOLVE INTO A NEW
THUNDERSTORM COMPLEX ACROSS WESTERN IOWA THIS EVENING IN THE
BETTER FORCING AND SLOWLY MOVE EASTWARD WITH ACTIVITY ENTERING THE
NORTHWEST HALF OF THE AREA AFTER MIDNIGHT.
&&
.SYNOPSIS...
ISSUED AT 356 PM CDT SUN MAY 11 2014
12Z UA ANALYSIS HAS 850MB LOWS IN NORTHWEST MINNESOTA WITH A STRONG
850MB LOW IN WESTERN KANSAS. AN 850MB WARM FRONT RAN FROM THE KANSAS
LOW INTO SOUTHERN IOWA. A STRONG LLJ RAN FROM THE GULF COAST INTO
THE CENTRAL PLAINS. SATELLITE/RADAR TRENDS THROUGH MID AFTERNOON HAS
CONVECTION ACROSS EASTERN IOWA AND NORTHERN ILLINOIS WITH NEW
CONVECTION DEVELOPING IN THE PLAINS.
18Z SFC ANALYSIS HAS A WEAK LOW IN WESTERN WISCONSIN WITH A
DEVELOPING WARM FRONT SOUTHEAST INTO CENTRAL LAKE MICHIGAN. AN
IMPLIED LOW WAS IN SOUTHERN IOWA APPROACHING KOTM WITH ANOTHER LOW
IN WESTERN KANSAS. A FRONTAL BOUNDARY RAN FROM THE KANSAS LOW INTO
THE IOWA LOW NEAR KOTM WITH A WARM FRONT FROM NEAR KOTM NORTHEAST TO
THE WISCONSIN/ILLINOIS BORDER. DEW POINTS SOUTH OF THE FRONT WERE IN
THE 60S WITH 40S AND 50S IN THE NORTHERN PLAINS INTO THE GREAT LAKES
NORTH OF THE FRONT.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 356 PM CDT SUN MAY 11 2014
BOUNDARIES FROM THE NOCTURNAL THUNDERSTORM COMPLEX INITIATED A NEW
STORM COMPLEX ALONG THE WARM FRONT IN SOUTHERN IOWA THIS MORNING.
THIS NEW STORM COMPLEX MOVED EAST NORTHEAST AND IS SLOWLY DECAYING
ACROSS THE AREA.
HOWEVER...BOUNDARIES FROM THIS STORM ALONG WITH DIURNAL HEATING HAS
INITIATED NEW DISCRETE STRONG TO SEVERE STORMS THAT WILL CONTINUE
THROUGH LATE AFTERNOON.
BASED ON SATELLITE...RADAR...AND RAP TRENDS...THERE MAY BE A BREAK
IN STORM ACTIVITY THIS EVENING AS THE NEW SEVERE STORMS CONTINUE TO
DEVELOP AND MOVE NORTHEAST WELL WEST OF THE AREA.
AFTER MIDNIGHT THE STORMS OUT WEST WILL EVOLVE UPSCALE INTO ANOTHER
NOCTURNAL THUNDERSTORM COMPLEX THAT WILL SLOWLY MOVE INTO THE
NORTHWEST THIRD OF THE AREA. ISOLATED TO SCATTERED STORMS ARE VERY
POSSIBLE AHEAD OF THIS STORM COMPLEX AS MOISTURE CONTINUES TO FEED
INTO THE AREA.
ON MONDAY THE BETTER RAIN CHANCES WILL BE OVER THE NORTHWEST HALF OF
THE AREA DURING THE MORNING. DURING THE AFTERNOON...NEW CONVECTION
IS EXPECTED TO DEVELOP AS ANOTHER DISTURBANCE ALOFT MOVES THROUGH
THE AREA. BASED ON THE POSITION OF THE MAIN FEATURES AND OVERALL
EXPECTED FORCING...SEVERE STORMS ARE POSSIBLE.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 356 PM CDT SUN MAY 11 2014
MONDAY NIGHT THE MAIN COLD FRONT BEGINS MOVING THROUGH THE AREA.
CONVECTION IS EXPECTED TO BE WIDESPREAD AND MAY EVOLVE INTO A BAND
OF STRONG STORMS DURING THE EVENING HOURS. IF A BAND DOES FORM IT
WILL SLOWLY MOVE EAST OVERNIGHT.
ON TUESDAY...RAIN WILL END FROM WEST TO EAST DURING THE DAY WITH
MOST OF THE AREA BEING DRY BY MID DAY. TEMPERATURES WILL BE WELL
BELOW NORMAL.
HIGH PRESSURE MOVING THROUGH THE MIDWEST TUESDAY NIGHT WILL RESULT
IN DRY CONDITIONS WITH SEASONABLY COOL TEMPERATURES.
ON WEDNESDAY THE NEXT STORM SYSTEM MOVES NORTHEAST FROM THE SOUTHERN
PLAINS INTO THE OHIO VALLEY. THE TRENDS WITH THE MODELS HAVE BEEN TO
SLOWLY PULL THE STORM SYSTEM TO THE NORTH AND WEST.
WEDNESDAY NIGHT ON...
THERE CONTINUES TO BE DIFFERENCES BETWEEN THE GLOBAL MODELS AS TO
WHAT WILL OCCUR...BUT...ALL AGREE THAT TEMPERATURES WILL AVERAGE
BELOW NORMAL WEDNESDAY NIGHT THROUGH SUNDAY.
WEDNESDAY NIGHT/THURSDAY THE MODEL CONSENSUS HAS SLIGHT CHANCE TO
CHANCE POPS AS THE NEXT SYSTEM MOVES UP THROUGH THE OHIO VALLEY. THE
TREND IN THE MODELS HAS BEEN TO SLOWLY BRING THE STORM FURTHER TO
THE NORTH AND WEST.
THE MODEL CONSENSUS HAS MAINLY DRY CONDITIONS THURSDAY NIGHT AS THE
STORM SYSTEM EXITS THE AREA.
FRIDAY THROUGH SATURDAY THE MODEL CONSENSUS HAS MAINLY SLIGHT CHANCE
POPS FRIDAY AND SATURDAY WITH MAINLY DRY CONDITIONS FRIDAY NIGHT.
DISTURBANCES WILL CONTINUE TO ROTATE AROUND THE UPPER LOW OVER THE
GREAT LAKES PRODUCING MAINLY DIURNAL SHOWERS. IF ENOUGH CLEARING CAN
TAKE PLACE FRIDAY NIGHT AND WINDS REMAIN LIGHT...THERE MAY BE A
POTENTIAL FOR FROST.
DRY CONDITIONS SHOULD BE SEEN SATURDAY NIGHT AS HIGH PRESSURE MOVES
THROUGH THE AREA.
ON SUNDAY...THE MODEL CONSENSUS HAS SLIGHT CHANCE TO CHANCE POPS FOR
ROUGHLY THE WESTERN HALF OF THE AREA AS THE NEXT STORM SYSTEM MOVES
EAST FROM THE PLAINS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 635 PM CDT SUN MAY 11 2014
VFR CONDITIONS WILL BE SEEN THROUGH 06Z/12 EXCEPT AROUND THE
CONVECTION THAT MAY AFFECT KMLI/KBRL THROUGH 02Z/12. AFT 06Z/12 A
THUNDERSTORM COMPLEX WILL DEVELOP IN WESTERN IOWA THAT SLOWLY
MOVES EAST. THIS STORM COMPLEX SHOULD BEGIN ENTERING EASTERN IOWA
PRIOR TO SUNRISE. VFR CONDITIONS SHOULD BE SEEN THROUGH SUNRISE
WITH POSSIBLE MVFR CONDITIONS AS CONVECTION MOVES INTO EASTERN
IOWA. AFT 12Z/12 BORDERLINE MVFR/VFR CONDITIONS ARE EXPECTED WITH
SCATTERED TSRA. TSRA WILL DECAY/DISSIPATE MONDAY MORNING WITH NEW
TSRA DEVELOPMENT AFT 18Z/12 WITH POSSIBLE MVFR CONDITIONS.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...08
SYNOPSIS...08
SHORT TERM...08
LONG TERM...08
AVIATION...08
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
103 PM CDT SAT MAY 10 2014
.SYNOPSIS...
ISSUED AT 222 AM CDT SAT MAY 10 2014
00Z UPPER AIR ANALYSIS DEPICTED SHORTWAVE LIFTING NORTHEAST ACROSS
WISCONSIN WITH WEAK RIDGING DEVELOPING ACROSS THE UPPER PLAINS.
STRONG 130 KT JET ALSO ANALYZED COMING ONSHORE OVER CALIFORNIA.
LATEST WV IMAGERY SHOWS SEVERAL OTHER WEAKER WAVES MOVING IN THE
SEMI-ZONAL FLOW OVER THE PLAINS. THESE WAVES WERE RESPONSIBLE FOR
THE INCREASING CLOUDS OVER THE CENTRAL CONUS. AT THE SURFACE...A
RIDGE OF HIGH PRESSURE EXTENDED FROM FREEPORT ILLINOIS NORTHWEST
INTO NORTH DAKOTA.
TEMPERATURES AS OF 2AM WERE IN THE LOWER 40S TO LOWER 50S WITH
THE LOWEST READINGS SEEN IN THE WAPSI RIVER VALLEY. DEWPOINTS WERE
IN THE UPPER 30S TO MIDDLE 40S.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 222 AM CDT SAT MAY 10 2014
FORECAST FOCUS ON PCPN CHANCES THIS EVENING AND INTO SUNDAY WITH
A CHANCE OF A FEW STRONG TO SEVERE STORMS MAINLY IN THE FAR SOUTH
PORTIONS OF THE CWA
TODAY...SURFACE RIDGE AXIS TO MOVE EAST OVER THE GREAT LAKES TODAY
RESULTING IN A S-SE RETURN FLOW. THIS COMBINED WITH SLOWLY WARMING
TEMPERATURES ALOFT WILL ALLOW FOR A WARMER DAY THAN COMPARED TO
YESTERDAY. DEEP MIXING...DEWPOINTS IN THE 40S...AND AT LEAST PARTLY
SUNNY SKIES WILL BOOST TEMPERATURES WELL INTO THE 70S. A FEW
LOCATIONS IN THE FAR SOUTH MAY EVEN APPROACH 80 DEGREES. SURFACE
LOW TO DEVELOP ON LEE SIDE OF ROCKIES AND MOVE INTO WESTERN KANSAS
BY THIS EVENING. LATEST HI-RES MODELS AND RAP TRENDS SHOW
CONVECTION ACROSS NORTHWEST MISSOURI AROUND 21Z ALONG AND NORTH
OF A WARM FRONT TODAY AND PROPAGATE EAST. SOME OF THESE STORMS
MAY BECOME SEVERE DUE TO A FAVORABLE ENVIRONMENT WITH STEEP LOW
LEVEL LAPSE RATES...MUCAPES OVER 2000 J/KG...AND 0-6KM SHEAR VALES
IN EXCESS OF 50 KTS. AMOUNT OF DAYTIME HEATING WILL BE KEY AS TO
WHEN STORMS INITIATE. LOW FREEZING LEVELS SUGGEST THAT THE PRIMARY
THREAT WILL BE LARGE HAIL AS NOTED IN SPC DAY 1 OUTLOOK. LOW LEVEL
SHEAR ALTHOUGH MARGINAL MAY BE ENOUGH FOR AN ISOLATED TORNADO THREAT AS
WELL DUE TO THE CLOSE PROXIMITY OF THE WARM FRONT. THIS APPEARS
AT THIS TIME A BETTER POSSIBLY JUST SOUTH AND WEST OF THE CWA.
TONIGHT...FORCING PROGS AND TIME HEIGHT SECTIONS SHOW THE BEST
FORCING AND LOW LEVEL MOISTURE ARRIVING AFTER 00Z SUN ESPECIALLY
ACROSS THE SOUTH AS WARM FRONT IS DRAPED OVER NORTHERN MISSOURI
INTO SOUTHERN ILLINOIS. INCREASING LLJ OVERNIGHT SHOULD ALLOW
STORMS TO CONTINUE INTO THE NIGHT. QPF AMOUNTS WILL BE LESS THAN A
QUARTER OF AN INCH BY 12Z SUNDAY ACROSS MOST AREAS EXCEPT FOR
THOSE THAT RECEIVE A THUNDERSTORM. CLOUDS AND WAA ALOFT WILL ALLOW
FOR A MILD NIGHT...WITH LOWS IN THE MIDDLE 50S NORTH TO THE LOWER
60S IN THE SOUTH.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 222 AM CDT SAT MAY 10 2014
A DEEP UPPER TROF DEVELOPING OVER THE WESTERN U.S. WILL MOVE SLOWLY
EAST PUSHING A COLD FRONT THROUGH THE REGION MONDAY AND MONDAY
NIGHT. THE UPPER TROF AND COLD FRONT WILL KEEP THUNDERSTORM CHANCES
OVER THE FORECAST AREA THROUGH MONDAY NIGHT. THE LONG RANGE MODELS
ARE IN BETTER AGREEMENT ON THE 00Z RUN WITH THE TIMING OF THE
SURFACE FRONT THROUGH THE FORECAST AREA...ALTHOUGH THE 00Z ECMWF
CONTINUES TO LAG THE GFS/NAM TIMING. ALL MODEL SOLUTIONS ARE
POINTING TO A POTENTIALLY SIGNIFICANT SEVERE WEATHER EVENT FOR THE
MIDWEST SUNDAY AND SUNDAY NIGHT ALONG WITH A THREAT OF LOCALLY HEAVY
RAINS.
BY SUNDAY MORNING THE UPPER TROF IS PROGGED TO BE LOCATED OVER THE
ROCKIES WITH A COLD FRONT FROM WESTERN KANSAS THROUGH NORTHWEST IOWA
AND A WARM FRONT NEAR THE IA/MO BORDER. THE COLD FRONT WILL MOVE
SLOWLY EAST AS AT LEAST A COUPLE OF WAVES MOVE NORTHEAST ALONG THE
FRONT. THESE WAVES WILL KEEP THE FRONT FROM MOVING MUCH SUNDAY AND
SUNDAY NIGHT...THEN THE BOUNDARY SHOULD PUSH EAST MONDAY AND EXIT
THE FORECAST AREA MONDAY NIGHT. WARM MOIST AIR WILL SPREAD NORTH
AHEAD OF THE FRONT BRINGING MORE WARM AND HUMID CONDITIONS TO THE
REGION SUNDAY AND MONDAY. THE INFLUX OF THE WARM MOIST AIR WILL
PROVIDE A GOOD SUPPLY OF UNSTABLE AIR TO FUEL THUNDERSTORMS
ESPECIALLY SUNDAY AFTERNOON AND SUNDAY NIGHT. IT APPEARS THAT SOME
OF THE STORMS DURING THIS PERIOD WILL BE SEVERE WITH THE POTENTIAL
FOR LARGE HAIL...DAMAGING WINDS AND TORNADOES. THE TORNADIC THREAT
WILL BE THE GREATEST NEAR A WARM FRONT THAT IS EXPECTED TO EXTEND
THROUGH EAST CENTRAL OR NORTHEAST IOWA INTO NORTHERN ILLINOIS OR
SOUTHERN WI BY SUNDAY EVENING. A HEAVY RAIN THREAT WILL ALSO EXIST
SUNDAY AND SUNDAY NIGHT WITH PW/S EXPECTED TO BE AROUND 1.5 TO 1.75
INCHES. THE COLD FRONT TO THE WEST AND THE WARM FRONT WILL PROVIDE
THE FOCUS FOR THE HEAVIER RAINFALL. LATEST WPC GUIDANCE SHOWS A
SWATH OF 2 TO 4 INCHES OF RAIN SUNDAY AND SUNDAY NIGHT FROM
NORTHEAST THROUGH SOUTHWEST IOWA. WHILE THE AMOUNTS LOOK REASONABLE
GIVEN THE MOIST ENVIRONMENT THERE IS STILL SOME UNCERTAINTY ON THE
LOCATION OF THE SURFACE BOUNDARIES...SO KEPT THE FORECAST QPF LOWER
THAN WPC.
THE COLD FRONT IS EXPECTED TO MOVE THROUGH THE FORECAST AREA MONDAY
OR MONDAY EVENING. THIS WILL KEEP THE CWFA IN THE UNSEASONABLY WARM
AND MOIST AIRMASS FOR MOST IF NOT ALL OF MONDAY. THERE WILL ALSO BE
A CONTINUED THREAT OF SEVERE THUNDERSTORMS UNTIL THE COLD FRONT
MOVES THROUGH.
FOR THE REST OF THE WEEK THE MODEL SOLUTIONS DIVERGE WITH RESPECT TO
THE UPPER TROF. THE ECMWF CONTINUES TO FAVOR A SLOWER EASTWARD
PROGRESSION THAN THE GFS. WITH THE SLOWER ECM PROGS WILL HAVE TO
KEEP A CHANCE OF SHOWERS GOING MOST DAYS FROM TUESDAY THROUGH
FRIDAY. AFTER THE COLD FROPA MONDAY NIGHT TEMPERATURES WILL RETURN
TO BELOW NORMAL FOR THE REST OF THE WEEK. HIGHS SHOULD BE IN THE
UPPER 50S TO MID 60S WITH LOWS MAINLY IN THE 40S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1249 PM CDT SAT MAY 10 2014
MAINLY VFR CONDITIONS EXPECTED THROUGH SUNDAY AM. FEW HIGH BASED
LIGHT SHOWERS WILL MOVE ACROSS NORTHEAST IA EARLY THIS AFTERNOON.
ADDITIONAL SCATTERED SHOWERS AND STORMS EXPECTED TO DEVELOP
MID TO LATE AFTERNOON INTO EARLY EVENING TO W/SW OF CWA... AND
ANTICIPATE BULK OF STORMS WITH POTENTIAL FOR STRONG TO SEVERE
STORMS TO SLIDE E/SE SOUTH OF TERMINALS NORTH OF WARM FRONT ALONG
MOISTURE GRADIENT. STILL EXPECT AT LEAST SOME SCATTERED SHOWERS
AND POSSIBLY FEW STORMS AROUND THE AREA THIS EVENING EXITING
OVERNIGHT WITH PASSAGE OF UPPER LEVEL DISTURBANCE. THEN... WILL
HAVE POTENTIAL FOR ELEVATED SCATTERED SHOWERS AND STORMS
DEVELOPING LATE TONIGHT FAR SOUTHEAST IA...NORTHEAST MO INTO WEST
CENTRAL IL NORTH OF WARM FRONT. THIS ACTIVITY MAY CONTINUE TO
DEVELOP AND/OR LIFT NORTHWARD THROUGH EASTERN IA SUNDAY AM. WINDS
WILL REMAIN SOUTHERLY AROUND 10 KTS THROUGH THE PERIOD AND
OCCASIONALLY GUST AROUND 20-25 KTS THIS AFTERNOON AND AGAIN MID TO
LATE SUNDAY AM.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...GROSS
SHORT TERM...GROSS
LONG TERM...DLF
AVIATION...05
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
651 AM CDT SAT MAY 10 2014
.SYNOPSIS...
ISSUED AT 222 AM CDT SAT MAY 10 2014
00Z UPPER AIR ANALYSIS DEPICTED SHORTWAVE LIFTING NORTHEAST ACROSS
WISCONSIN WITH WEAK RIDGING DEVELOPING ACROSS THE UPPER PLAINS.
STRONG 130 KT JET ALSO ANALYZED COMING ONSHORE OVER CALIFORNIA.
LATEST WV IMAGERY SHOWS SEVERAL OTHER WEAKER WAVES MOVING IN THE
SEMI-ZONAL FLOW OVER THE PLAINS. THESE WAVES WERE RESPONSIBLE FOR
THE INCREASING CLOUDS OVER THE CENTRAL CONUS. AT THE SURFACE...A
RIDGE OF HIGH PRESSURE EXTENDED FROM FREEPORT ILLINOIS NORTHWEST
INTO NORTH DAKOTA.
TEMPERATURES AS OF 2AM WERE IN THE LOWER 40S TO LOWER 50S WITH
THE LOWEST READINGS SEEN IN THE WAPSI RIVER VALLEY. DEWPOINTS WERE
IN THE UPPER 30S TO MIDDLE 40S.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 222 AM CDT SAT MAY 10 2014
FORECAST FOCUS ON PCPN CHANCES THIS EVENING AND INTO SUNDAY WITH
A CHANCE OF A FEW STRONG TO SEVERE STORMS MAINLY IN THE FAR SOUTH
PORTIONS OF THE CWA
TODAY...SURFACE RIDGE AXIS TO MOVE EAST OVER THE GREAT LAKES TODAY
RESULTING IN A S-SE RETURN FLOW. THIS COMBINED WITH SLOWLY WARMING
TEMPERATURES ALOFT WILL ALLOW FOR A WARMER DAY THAN COMPARED TO
YESTERDAY. DEEP MIXING...DEWPOINTS IN THE 40S...AND AT LEAST PARTLY
SUNNY SKIES WILL BOOST TEMPERATURES WELL INTO THE 70S. A FEW
LOCATIONS IN THE FAR SOUTH MAY EVEN APPROACH 80 DEGREES. SURFACE
LOW TO DEVELOP ON LEE SIDE OF ROCKIES AND MOVE INTO WESTERN KANSAS
BY THIS EVENING. LATEST HI-RES MODELS AND RAP TRENDS SHOW
CONVECTION ACROSS NORTHWEST MISSOURI AROUND 21Z ALONG AND NORTH
OF A WARM FRONT TODAY AND PROPAGATE EAST. SOME OF THESE STORMS
MAY BECOME SEVERE DUE TO A FAVORABLE ENVIRONMENT WITH STEEP LOW
LEVEL LAPSE RATES...MUCAPES OVER 2000 J/KG...AND 0-6KM SHEAR VALES
IN EXCESS OF 50 KTS. AMOUNT OF DAYTIME HEATING WILL BE KEY AS TO
WHEN STORMS INITIATE. LOW FREEZING LEVELS SUGGEST THAT THE PRIMARY
THREAT WILL BE LARGE HAIL AS NOTED IN SPC DAY 1 OUTLOOK. LOW LEVEL
SHEAR ALTHOUGH MARGINAL MAY BE ENOUGH FOR AN ISOLATED TORNADO THREAT AS
WELL DUE TO THE CLOSE PROXIMITY OF THE WARM FRONT. THIS APPEARS
AT THIS TIME A BETTER POSSIBLY JUST SOUTH AND WEST OF THE CWA.
TONIGHT...FORCING PROGS AND TIME HEIGHT SECTIONS SHOW THE BEST
FORCING AND LOW LEVEL MOISTURE ARRIVING AFTER 00Z SUN ESPECIALLY
ACROSS THE SOUTH AS WARM FRONT IS DRAPED OVER NORTHERN MISSOURI
INTO SOUTHERN ILLINOIS. INCREASING LLJ OVERNIGHT SHOULD ALLOW
STORMS TO CONTINUE INTO THE NIGHT. QPF AMOUNTS WILL BE LESS THAN A
QUARTER OF AN INCH BY 12Z SUNDAY ACROSS MOST AREAS EXCEPT FOR
THOSE THAT RECEIVE A THUNDERSTORM. CLOUDS AND WAA ALOFT WILL ALLOW
FOR A MILD NIGHT...WITH LOWS IN THE MIDDLE 50S NORTH TO THE LOWER
60S IN THE SOUTH.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 222 AM CDT SAT MAY 10 2014
A DEEP UPPER TROF DEVELOPING OVER THE WESTERN U.S. WILL MOVE SLOWLY
EAST PUSHING A COLD FRONT THROUGH THE REGION MONDAY AND MONDAY
NIGHT. THE UPPER TROF AND COLD FRONT WILL KEEP THUNDERSTORM CHANCES
OVER THE FORECAST AREA THROUGH MONDAY NIGHT. THE LONG RANGE MODELS
ARE IN BETTER AGREEMENT ON THE 00Z RUN WITH THE TIMING OF THE
SURFACE FRONT THROUGH THE FORECAST AREA...ALTHOUGH THE 00Z ECMWF
CONTINUES TO LAG THE GFS/NAM TIMING. ALL MODEL SOLUTIONS ARE
POINTING TO A POTENTIALLY SIGNIFICANT SEVERE WEATHER EVENT FOR THE
MIDWEST SUNDAY AND SUNDAY NIGHT ALONG WITH A THREAT OF LOCALLY HEAVY
RAINS.
BY SUNDAY MORNING THE UPPER TROF IS PROGGED TO BE LOCATED OVER THE
ROCKIES WITH A COLD FRONT FROM WESTERN KANSAS THROUGH NORTHWEST IOWA
AND A WARM FRONT NEAR THE IA/MO BORDER. THE COLD FRONT WILL MOVE
SLOWLY EAST AS AT LEAST A COUPLE OF WAVES MOVE NORTHEAST ALONG THE
FRONT. THESE WAVES WILL KEEP THE FRONT FROM MOVING MUCH SUNDAY AND
SUNDAY NIGHT...THEN THE BOUNDARY SHOULD PUSH EAST MONDAY AND EXIT
THE FORECAST AREA MONDAY NIGHT. WARM MOIST AIR WILL SPREAD NORTH
AHEAD OF THE FRONT BRINGING MORE WARM AND HUMID CONDITIONS TO THE
REGION SUNDAY AND MONDAY. THE INFLUX OF THE WARM MOIST AIR WILL
PROVIDE A GOOD SUPPLY OF UNSTABLE AIR TO FUEL THUNDERSTORMS
ESPECIALLY SUNDAY AFTERNOON AND SUNDAY NIGHT. IT APPEARS THAT SOME
OF THE STORMS DURING THIS PERIOD WILL BE SEVERE WITH THE POTENTIAL
FOR LARGE HAIL...DAMAGING WINDS AND TORNADOES. THE TORNADIC THREAT
WILL BE THE GREATEST NEAR A WARM FRONT THAT IS EXPECTED TO EXTEND
THROUGH EAST CENTRAL OR NORTHEAST IOWA INTO NORTHERN ILLINOIS OR
SOUTHERN WI BY SUNDAY EVENING. A HEAVY RAIN THREAT WILL ALSO EXIST
SUNDAY AND SUNDAY NIGHT WITH PW/S EXPECTED TO BE AROUND 1.5 TO 1.75
INCHES. THE COLD FRONT TO THE WEST AND THE WARM FRONT WILL PROVIDE
THE FOCUS FOR THE HEAVIER RAINFALL. LATEST WPC GUIDANCE SHOWS A
SWATH OF 2 TO 4 INCHES OF RAIN SUNDAY AND SUNDAY NIGHT FROM
NORTHEAST THROUGH SOUTHWEST IOWA. WHILE THE AMOUNTS LOOK REASONABLE
GIVEN THE MOIST ENVIRONMENT THERE IS STILL SOME UNCERTAINTY ON THE
LOCATION OF THE SURFACE BOUNDARIES...SO KEPT THE FORECAST QPF LOWER
THAN WPC.
THE COLD FRONT IS EXPECTED TO MOVE THROUGH THE FORECAST AREA MONDAY
OR MONDAY EVENING. THIS WILL KEEP THE CWFA IN THE UNSEASONABLY WARM
AND MOIST AIRMASS FOR MOST IF NOT ALL OF MONDAY. THERE WILL ALSO BE
A CONTINUED THREAT OF SEVERE THUNDERSTORMS UNTIL THE COLD FRONT
MOVES THROUGH.
FOR THE REST OF THE WEEK THE MODEL SOLUTIONS DIVERGE WITH RESPECT TO
THE UPPER TROF. THE ECMWF CONTINUES TO FAVOR A SLOWER EASTWARD
PROGRESSION THAN THE GFS. WITH THE SLOWER ECM PROGS WILL HAVE TO
KEEP A CHANCE OF SHOWERS GOING MOST DAYS FROM TUESDAY THROUGH
FRIDAY. AFTER THE COLD FROPA MONDAY NIGHT TEMPERATURES WILL RETURN
TO BELOW NORMAL FOR THE REST OF THE WEEK. HIGHS SHOULD BE IN THE
UPPER 50S TO MID 60S WITH LOWS MAINLY IN THE 40S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 631 AM CDT SAT MAY 10 2014
VFR CONDITIONS EXPECTED THROUGH THE TAF CYCLE. SURFACE RIDGE TO
CONTINUE TO MOVE EAST THIS MORNING RESULTING IN S-SE WINDS
DEVELOPING. HIGH BASED STORMS TO FORM DURING THE LATE AFTERNOON IN
NORTHWEST MISSOURI AND PUSH EAST AFFECTING THE TERMINALS MAINLY
DURING THE LATE EVENING HOURS. THUNDERSTORM POTENTIAL GREATEST IN
NORTHERN MISSOURI AND SOUTHEAST IOWA AND HAVE INCLUDED TEMPO GROUP
AT THE BRL TERMINAL. ELEVATED STORMS WILL KEEP CIGS/VSBYS
GENERALLY VFR THROUGH 12Z SUNDAY.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...GROSS
SHORT TERM...GROSS
LONG TERM...DLF
AVIATION...GROSS
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
315 AM CDT SAT MAY 10 2014
.SYNOPSIS...
ISSUED AT 222 AM CDT SAT MAY 10 2014
00Z UPPER AIR ANALYSIS DEPICTED SHORTWAVE LIFTING NORTHEAST ACROSS
WISCONSIN WITH WEAK RIDGING DEVELOPING ACROSS THE UPPER PLAINS.
STRONG 130 KT JET ALSO ANALYZED COMING ONSHORE OVER CALIFORNIA.
LATEST WV IMAGERY SHOWS SEVERAL OTHER WEAKER WAVES MOVING IN THE
SEMI-ZONAL FLOW OVER THE PLAINS. THESE WAVES WERE RESPONSIBLE FOR
THE INCREASING CLOUDS OVER THE CENTRAL CONUS. AT THE SURFACE...A
RIDGE OF HIGH PRESSURE EXTENDED FROM FREEPORT ILLINOIS NORTHWEST
INTO NORTH DAKOTA.
TEMPERATURES AS OF 2AM WERE IN THE LOWER 40S TO LOWER 50S WITH
THE LOWEST READINGS SEEN IN THE WAPSI RIVER VALLEY. DEWPOINTS WERE
IN THE UPPER 30S TO MIDDLE 40S.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 222 AM CDT SAT MAY 10 2014
FORECAST FOCUS ON PCPN CHANCES THIS EVENING AND INTO SUNDAY WITH
A CHANCE OF A FEW STRONG TO SEVERE STORMS MAINLY IN THE FAR SOUTH
PORTIONS OF THE CWA
TODAY...SURFACE RIDGE AXIS TO MOVE EAST OVER THE GREAT LAKES TODAY
RESULTING IN A S-SE RETURN FLOW. THIS COMBINED WITH SLOWLY WARMING
TEMPERATURES ALOFT WILL ALLOW FOR A WARMER DAY THAN COMPARED TO
YESTERDAY. DEEP MIXING...DEWPOINTS IN THE 40S...AND AT LEAST PARTLY
SUNNY SKIES WILL BOOST TEMPERATURES WELL INTO THE 70S. A FEW
LOCATIONS IN THE FAR SOUTH MAY EVEN APPROACH 80 DEGREES. SURFACE
LOW TO DEVELOP ON LEE SIDE OF ROCKIES AND MOVE INTO WESTERN KANSAS
BY THIS EVENING. LATEST HI-RES MODELS AND RAP TRENDS SHOW
CONVECTION ACROSS NORTHWEST MISSOURI AROUND 21Z ALONG AND NORTH
OF A WARM FRONT TODAY AND PROPAGATE EAST. SOME OF THESE STORMS
MAY BECOME SEVERE DUE TO A FAVORABLE ENVIRONMENT WITH STEEP LOW
LEVEL LAPSE RATES...MUCAPES OVER 2000 J/KG...AND 0-6KM SHEAR VALES
IN EXCESS OF 50 KTS. AMOUNT OF DAYTIME HEATING WILL BE KEY AS TO
WHEN STORMS INITIATE. LOW FREEZING LEVELS SUGGEST THAT THE PRIMARY
THREAT WILL BE LARGE HAIL AS NOTED IN SPC DAY 1 OUTLOOK. LOW LEVEL
SHEAR ALTHOUGH MARGINAL MAY BE ENOUGH FOR AN ISOLATED TORNADO THREAT AS
WELL DUE TO THE CLOSE PROXIMITY OF THE WARM FRONT. THIS APPEARS
AT THIS TIME A BETTER POSSIBLY JUST SOUTH AND WEST OF THE CWA.
TONIGHT...FORCING PROGS AND TIME HEIGHT SECTIONS SHOW THE BEST
FORCING AND LOW LEVEL MOISTURE ARRIVING AFTER 00Z SUN ESPECIALLY
ACROSS THE SOUTH AS WARM FRONT IS DRAPED OVER NORTHERN MISSOURI
INTO SOUTHERN ILLINOIS. INCREASING LLJ OVERNIGHT SHOULD ALLOW
STORMS TO CONTINUE INTO THE NIGHT. QPF AMOUNTS WILL BE LESS THAN A
QUARTER OF AN INCH BY 12Z SUNDAY ACROSS MOST AREAS EXCEPT FOR
THOSE THAT RECEIVE A THUNDERSTORM. CLOUDS AND WAA ALOFT WILL ALLOW
FOR A MILD NIGHT...WITH LOWS IN THE MIDDLE 50S NORTH TO THE LOWER
60S IN THE SOUTH.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 222 AM CDT SAT MAY 10 2014
A DEEP UPPER TROF DEVELOPING OVER THE WESTERN U.S. WILL MOVE SLOWLY
EAST PUSHING A COLD FRONT THROUGH THE REGION MONDAY AND MONDAY
NIGHT. THE UPPER TROF AND COLD FRONT WILL KEEP THUNDERSTORM CHANCES
OVER THE FORECAST AREA THROUGH MONDAY NIGHT. THE LONG RANGE MODELS
ARE IN BETTER AGREEMENT ON THE 00Z RUN WITH THE TIMING OF THE
SURFACE FRONT THROUGH THE FORECAST AREA...ALTHOUGH THE 00Z ECMWF
CONTINUES TO LAG THE GFS/NAM TIMING. ALL MODEL SOLUTIONS ARE
POINTING TO A POTENTIALLY SIGNIFICANT SEVERE WEATHER EVENT FOR THE
MIDWEST SUNDAY AND SUNDAY NIGHT ALONG WITH A THREAT OF LOCALLY HEAVY
RAINS.
BY SUNDAY MORNING THE UPPER TROF IS PROGGED TO BE LOCATED OVER THE
ROCKIES WITH A COLD FRONT FROM WESTERN KANSAS THROUGH NORTHWEST IOWA
AND A WARM FRONT NEAR THE IA/MO BORDER. THE COLD FRONT WILL MOVE
SLOWLY EAST AS AT LEAST A COUPLE OF WAVES MOVE NORTHEAST ALONG THE
FRONT. THESE WAVES WILL KEEP THE FRONT FROM MOVING MUCH SUNDAY AND
SUNDAY NIGHT...THEN THE BOUNDARY SHOULD PUSH EAST MONDAY AND EXIT
THE FORECAST AREA MONDAY NIGHT. WARM MOIST AIR WILL SPREAD NORTH
AHEAD OF THE FRONT BRINGING MORE WARM AND HUMID CONDITIONS TO THE
REGION SUNDAY AND MONDAY. THE INFLUX OF THE WARM MOIST AIR WILL
PROVIDE A GOOD SUPPLY OF UNSTABLE AIR TO FUEL THUNDERSTORMS
ESPECIALLY SUNDAY AFTERNOON AND SUNDAY NIGHT. IT APPEARS THAT SOME
OF THE STORMS DURING THIS PERIOD WILL BE SEVERE WITH THE POTENTIAL
FOR LARGE HAIL...DAMAGING WINDS AND TORNADOES. THE TORNADIC THREAT
WILL BE THE GREATEST NEAR A WARM FRONT THAT IS EXPECTED TO EXTEND
THROUGH EAST CENTRAL OR NORTHEAST IOWA INTO NORTHERN ILLINOIS OR
SOUTHERN WI BY SUNDAY EVENING. A HEAVY RAIN THREAT WILL ALSO EXIST
SUNDAY AND SUNDAY NIGHT WITH PW/S EXPECTED TO BE AROUND 1.5 TO 1.75
INCHES. THE COLD FRONT TO THE WEST AND THE WARM FRONT WILL PROVIDE
THE FOCUS FOR THE HEAVIER RAINFALL. LATEST WPC GUIDANCE SHOWS A
SWATH OF 2 TO 4 INCHES OF RAIN SUNDAY AND SUNDAY NIGHT FROM
NORTHEAST THROUGH SOUTHWEST IOWA. WHILE THE AMOUNTS LOOK REASONABLE
GIVEN THE MOIST ENVIRONMENT THERE IS STILL SOME UNCERTAINTY ON THE
LOCATION OF THE SURFACE BOUNDARIES...SO KEPT THE FORECAST QPF LOWER
THAN WPC.
THE COLD FRONT IS EXPECTED TO MOVE THROUGH THE FORECAST AREA MONDAY
OR MONDAY EVENING. THIS WILL KEEP THE CWFA IN THE UNSEASONABLY WARM
AND MOIST AIRMASS FOR MOST IF NOT ALL OF MONDAY. THERE WILL ALSO BE
A CONTINUED THREAT OF SEVERE THUNDERSTORMS UNTIL THE COLD FRONT
MOVES THROUGH.
FOR THE REST OF THE WEEK THE MODEL SOLUTIONS DIVERGE WITH RESPECT TO
THE UPPER TROF. THE ECMWF CONTINUES TO FAVOR A SLOWER EASTWARD
PROGRESSION THAN THE GFS. WITH THE SLOWER ECM PROGS WILL HAVE TO
KEEP A CHANCE OF SHOWERS GOING MOST DAYS FROM TUESDAY THROUGH
FRIDAY. AFTER THE COLD FROPA MONDAY NIGHT TEMPERATURES WILL RETURN
TO BELOW NORMAL FOR THE REST OF THE WEEK. HIGHS SHOULD BE IN THE
UPPER 50S TO MID 60S WITH LOWS MAINLY IN THE 40S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1130 PM CDT FRI MAY 9 2014
SFC RIDGE CONTINUES TO MIGRATE EASTWARD ACRS THE REGION...
MAINTAINING VFR CONDITIONS THROUGH SAT AFTERNOON. LIGHT AND
VARIABLE WINDS ACRS THE AREA OVERNIGHT...WILL BECOME SOUTHERLY
10-15 KTS BEHIND PASSING RIDGE ON SAT. HIGH CLOUDS TO INCREASE AS
SFC WINDS BACK MORE SOUTHEASTERLY BY LATE SAT AFTERNOON AND EARLY
EVENING. ELEVATED PLUME OF WARM AIR ADVECTION MAY TOUCH OFF A FEW
HIGH BASED SHOWERS AND THUNDERSTORMS BY MID SAT EVENING ACRS
CENTRAL IA...WITH A CHANCE THAT SOME OF THESE MAKE IT FAR ENOUGH
TO THE EAST TO GET IN THE VCNTY OF CID...DBQ AND POSSIBLY BRL FROM
03Z-06Z SUNDAY. WITH THE ELEVATED NATURE OF THESE SHOWERS/STORMS...
CIGS STILL MAY REMAIN VFR THROUGH THE END OF THE TAF PERIOD.
..12..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...GROSS
SHORT TERM...GROSS
LONG TERM...DLF
AVIATION...12
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1010 PM CDT Sun May 11 2014
...UPDATE TO SYNOPSIS...
.SYNOPSIS...
ISSUED AT 1007 PM CDT SUN MAY 11 2014
Water vapor imagery and 00Z upper air analysis indicate a strong
closed off upper level low shifting eastward across the Four Corners
Region. A +70kt upper level jet is lifting northeast across western
Kansas. Near the surface, a strong cold front extending from
northeastern Kansas southwest into the Oklahoma panhandle, is
pushing southeast across central Kansas. Much colder and drier
air is spilling southward into western Kansas with surface
dewpoints dropping mainly into the 40s(F) with a few 30s(F)
out near the Colorado border.
&&
.SHORT TERM...(This evening through Monday)
ISSUED AT 254 PM CDT SUN MAY 11 2014
Abbreviated AFD due to ongoing warning operations.
From my mesoscale discussion at 1:53 PM...
(Convection already has developed by the same mesoscale assessments
still applies)
Special 18Z KDDC raob shows just a little bit of CIN remaining. Won`t
be long before convection develops. Visible satellite imagery shows
increasing cumulus along the dryline/front. HRRR indicates thunderstorms
developing along the Highway 283 corridor in the 3-4 pm time range.
Right moving Bunkers shows propagation vectors northeasterly at 45 kt.
Initial threat will be large hail (up to 20! on the LHP using NAM thermodynamic
and kinematic variables) and damaging outflow winds. There is an small
window of tornadic opportunity between 7 and 9 pm as low level winds
back across central/south central-Kansas but all the big wedge/strong tornadoes
should remain across Nebraska/Iowa with just small spin ups/weak tornadoes
in our area, if possible.
Convection will depart the area tonight. Some light showers will be
possible on the backside of the departing wave. It will be windy post
frontal through tomorrow. Right now conditions look borderline for wind
advisory criteria.
.LONG TERM...(Monday night through Sunday)
ISSUED AT 122 PM CDT SUN MAY 11 2014
An upper level longwave trough will be moving across the Plains on
Tuesday but should be dry with the moisture pushed east of the area.
Colder temperatures will accompany this trough with overnight lows
on Monday night into the mid 30s and highs on Tuesday in the low to
mid 60s. Strong northwest winds will mix down to the surface with
winds of 15 to 30 mph and partly cloudy skies.
For Wednesday into Thursday, dry northwesterly upper level flow will
follow with highs slowly warming into the upper 60s and 70s.
Wednesday morning may be the coldest morning with light winds and
lows in the low to mid 30s.
For Friday and Saturday, a few showers and thunderstorms may form as
as some upper air disturbances in northwest flow aloft interact with
increasing upslope moisture. Lows will be in the 40s and highs
around 70 to 75.
On Sunday, of next week, upper level ridging is forecast with dry
and warmer temps around 80.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
ISSUED AT 649 PM CDT SUN MAY 11 2014
The severe weather threat will be diminishing early this evening
for DDC and HYS terminals. Winds will become strong north-
northwest this evening as the cold front moves through. Ceiling
will fall to 2000 to 3000 feet behind the front with MVFR
conditions expected through the night into tomorrow morning. VFR
will resume by around midday to early afternoon, but northwest
winds sustained around 20 knots will continue.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 46 56 35 63 / 20 10 0 0
GCK 42 53 34 62 / 20 20 0 0
EHA 42 55 34 61 / 10 10 0 10
LBL 44 58 34 62 / 10 10 0 10
HYS 46 53 35 63 / 80 30 0 0
P28 56 63 40 66 / 80 20 0 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY until 1 AM CDT /Midnight MDT/ Monday FOR KSZ030-
031-043>046-061>066-074>081-084>090.
&&
$$
SYNOPSIS...JJohnson
SHORT TERM...Sugden
LONG TERM...Kruse
AVIATION...Umscheid
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
653 PM CDT Sun May 11 2014
...Updated aviation section...
.SHORT TERM...(This evening through Monday)
ISSUED AT 254 PM CDT SUN MAY 11 2014
Abbreviated AFD due to ongoing warning operations.
From my mesoscale discussion at 1:53 PM...
(Convection already has developed by the same mesoscale assessments
still applies)
Special 18Z KDDC raob shows just a little bit of CIN remaining. Won`t
be long before convection develops. Visible satellite imagery shows
increasing cumulus along the dryline/front. HRRR indicates thunderstorms
developing along the Highway 283 corridor in the 3-4 pm time range.
Right moving Bunkers shows propagation vectors northeasterly at 45 kt.
Initial threat will be large hail (up to 20! on the LHP using NAM thermodynamic
and kinematic variables) and damaging outflow winds. There is an small
window of tornadic opportunity between 7 and 9 pm as low level winds
back across central/south central-Kansas but all the big wedge/strong tornadoes
should remain across Nebraska/Iowa with just small spin ups/weak tornadoes
in our area, if possible.
Convection will depart the area tonight. Some light showers will be
possible on the backside of the departing wave. It will be windy post
frontal through tomorrow. Right now conditions look borderline for wind
advisory criteria.
.LONG TERM...(Monday night through Sunday)
ISSUED AT 122 PM CDT SUN MAY 11 2014
An upper level longwave trough will be moving across the Plains on
Tuesday but should be dry with the moisture pushed east of the area.
Colder temperatures will accompany this trough with overnight lows
on Monday night into the mid 30s and highs on Tuesday in the low to
mid 60s. Strong northwest winds will mix down to the surface with
winds of 15 to 30 mph and partly cloudy skies.
For Wednesday into Thursday, dry northwesterly upper level flow will
follow with highs slowly warming into the upper 60s and 70s.
Wednesday morning may be the coldest morning with light winds and
lows in the low to mid 30s.
For Friday and Saturday, a few showers and thunderstorms may form as
as some upper air disturbances in northwest flow aloft interact with
increasing upslope moisture. Lows will be in the 40s and highs
around 70 to 75.
On Sunday, of next week, upper level ridging is forecast with dry
and warmer temps around 80.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
ISSUED AT 649 PM CDT SUN MAY 11 2014
The severe weather threat will be diminishing early this evening
for DDC and HYS terminals. Winds will become strong north-
northwest this evening as the cold front moves through. Ceiling
will fall to 2000 to 3000 feet behind the front with MVFR
conditions expected through the night into tomorrow morning. VFR
will resume by around midday to early afternoon, but northwest
winds sustained around 20 knots will continue.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 46 56 35 63 / 20 10 0 0
GCK 42 53 34 62 / 20 20 0 0
EHA 42 55 34 61 / 10 10 0 10
LBL 44 58 34 62 / 10 10 0 10
HYS 46 53 35 63 / 80 30 0 0
P28 56 63 40 66 / 80 20 0 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY until 8 PM CDT this evening FOR KSZ046-065-066-
078>081-088>090.
RED FLAG WARNING until 9 PM CDT this evening FOR KSZ074>076-
084>086.
&&
$$
SHORT TERM...Sugden
LONG TERM...Kruse
AVIATION...Umscheid
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1202 AM CDT Sat May 10 2014
...UPDATE TO AVIATION...
.SYNOPSIS...
ISSUED AT 955 PM CDT FRI MAY 9 2014
Water vapor imagery and 00Z upper air analysis indicate a zonal flow
aloft prevailing across the Western High Plains. Meanwhile, an upper
level trough is pushing southeast across the Pacific Northwest. Near
the surface...a weak lee side trough of low pressure is set up along
the Colorado and Kansas border. Drier air remains in place across
the area with surface dewpoints in the 30s(F) across central and
much of southwest Kansas.
&&
.SHORT TERM...(This evening through Saturday)
ISSUED AT 313 PM CDT FRI MAY 9 2014
The upper level jet is progged to continue moving east this
afternoon with western Kansas coming under the left exit region of
upper jet this evening. Model soundings from the NAM and RUC13 show
fairly deep mixing with some small elevated CAPE developing along
the Colorado border by late this afternoon. The last few runs of the
HRRR have been consistent in showing isolated showers developing
along the Colorado border and moving into west central and southwest
Kansas for a few hours this evening. Will add this to the grids for
this evening.
As the weak shortwave moves over late tonight, another weak surge of
high pressure will push into southwest Kansas late tonight and early
Saturday. Overnight lows will drop into the mid 40s over west
central Kansas where dewpoints will be lower and winds could go
light for a few hours around sunrise. Low temperatures in south
central Kansas may only drop into the mid 50s where dewpoints are
higher.
During the day Saturday, mid level flow over the central Plains
gradually becomes southwesterly with time as an upper level
shortwave trough digs into the western states. This will result in
surface cyclogenesis over southeast Colorado during the afternoon.
Areas of southwest Kansas along the Oklahoma border should see high
temperatures rising into the upper 80s to near 90 degrees with
southerly winds increasing during the day. This could result in
critical fire weather conditions over far southwest Kansas in the
afternoon.
.LONG TERM...(Saturday night through Friday)
ISSUED AT 349 PM CDT FRI MAY 9 2014
The first issue during this period will be Saturday night. Rich
gulf moisture is not too far southeast, meaning it`s as close as
extreme southeast Oklahoma and north Texas. With the vigorous jet
and upper level anomaly digging into the Rockies, the surface
response will be rapidly falling pressure in the lee of the
Rockies. The surface low should deepen in southeast Colorado.
Boundary layer winds will become east to southeast and the
aforementioned rich moisture will begin stream northwest towards
my forecast area. Warm frontogenesis will take place and this will
advance rapidly north by Saturday night. I see a small opportunity
of elevated and nocturnal convection developing along the nose of
the moisture surge across my far southeast area after dark
Saturday night. Confidence is not high though.
Sunday will be the "warm" day in advance of a strong surge of cold
air that will be sweeping into the plains as the digging system
into the Rockies lifts out into the plains. There should be a
rather tight gradient of temperatures across my area and will
adjust the grids accordingly. With the rich gulf moisture, strong
uvv and surface convergence along the front the chance for
thunderstorms will be high late Sunday and Sunday evening. Behind
the front there should be continued lift and with strong cold air
advection there should be low stratus and at least drizzle, if not
light rain. Monday should be a rather raw day with clouds,
blustery winds and some precipitation. My forecast highs may be a
little optimistic but the trend is to definitely cooler
temperatures.
Beyond Monday, the flow will be northwest flow aloft with perhaps
another minor wave sliding southeast which might promote showers
about mid week. Overall temperatures will be below normal seasonal
normals.
&&
.AVIATION...(For the 06Z TAFS through 06Z Saturday night)
ISSUED AT 1200 AM CDT SAT MAY 10 2014
VFR conditions will prevail at all TAF sites through early Saturday
evening. As for winds, light southeasterly winds will persist across
central and southwest Kansas overnight as a lee side trough remains
anchored along the Kansas and Colorado border. Winds will become
more light and variable Saturday as the surface trough shifts slowly
eastward across western Kansas.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 55 81 43 57 / 0 20 50 40
GCK 52 77 41 55 / 0 10 50 50
EHA 53 78 41 55 / 0 10 30 30
LBL 55 82 43 59 / 0 10 30 20
HYS 55 77 44 56 / 0 10 60 50
P28 63 91 49 65 / 0 40 50 50
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JJohnson
SHORT TERM...Gerard
LONG TERM...Hutton
AVIATION...JJohnson
AREA FORECAST DISCUSSION
NWS PADUCAH KY
930 PM CDT Sun May 11 2014
.UPDATE...
Issued at 930 PM CDT SUN MAY 11 2014
The likelihood of lightning strikes has dropped low enough
this evening that there will be no mention of them in the HWO or the
gridded products overnight. Despite ridging in the mid levels, the
tepid lower trop is such that a stray light rain shower cannot be
ruled out overnight, however.
&&
.SHORT TERM...(Tonight through Tuesday night)
Issued at 317 PM CDT SUN MAY 11 2014
Pockets of surface-based instability continue to expand over the
WFO PAH CWA this afternoon, aided by decent insolation and weak to
moderate directional shear (25-35 knots) aloft (as evidenced by
the anvil rain plumes oriented from northwest to southeast). The
old cold pool has eroded over southeast IL and southwest IN from
the morning convection, so distinct theta-e gradients are in
place. Given the GOES Water Vapor imagery, the moisture gradient
aloft implies a gradient in lapse rates as well, helping to
enhance updrafts. (This is evidenced by the newly organized storms
with hail in Southeast IL).
The 12km RUC also suggests that the expended CAPE along and north
of the implied surface warm frontal reflection arcing from
northwest to southeast through southeast Illinois into northwest
Kentucky. Further expenditure of CAPE through 01z suggests that
the pool of convective instability should drop markedly. In
addition, model heights are expected to rise this evening with a
subtle change in balance takes place between the eastern U.S. ridge
and the center of the sharpening trough over Western Nebraska.
Expect that rain chances will be essentially nil over the entire
WFO PAH CWA by midnight, as the warm frontal boundary moves well
north of the area and shear decreases with time.
As mentioned in yesterday`s discussion, channeled vorticity along
the eastern limb of the trough near the inflection point between
the trough/ridge circulation (cyclonic/anticyclonic flow) will aid
in creating some lift in advance of an approaching moisture plume
from the Gulf of Mexico around daybreak on Monday. This transition
zone for convection will move slowly east through Monday
afternoon, as the main trough actually sharpens and becomes
slightly negatively tilted west of Iowa and Missouri Monday night
into Tuesday morning.
By 09z (4 am CDT) Tuesday morning, the cold front associated with
this trough is expected to move into western sections of the WFO
PAH Forecast area (Southwest IL/Southeast MO). By late evening
Monday and into early Tuesday, the coverage of showers and
thunderstorms should pick up significantly. It is at this time,
that my concern for heavy rain potential will increase, with the
potential for at least minor flooding by daybreak on Tuesday over
parts of Southeast Missouri northeast to the Mississippi River.
QPF values in excess of two inches would not be out of the
question during that time period.
The 12km NAM-WRF is actually suggesting a new closed circulation
will develop at the based of the mean trough over the upper
Midwest, somewhere near the OK/TX panhandles by Tuesday night,
moving into southern Missouri by Wednesday evening. This is similar
to what the ECMWF advertised in the Friday/Saturday model runs. This
will lead to enhanced precipitation, both pre/post frontal as the
frontal boundary remains fixed along the Interstate 57/55 corridor
in Southern IL/Southeast Missouri. Most of the upright
(thunderstorm) instability may be mixed out by Tuesday afternoon and
night, but warm top (satellite reference) convection processes will
likely take over increasing the effectiveness of the rainfall from
Tuesday into Wednesday. There is still some question with respect to
severe potential during this time period, but heavy rainfall still
remains the dominant threat Tuesday into Wednesday.
.LONG TERM...(Wednesday through Sunday)
Issued at 417 PM CDT SUN MAY 11 2014
Confidence is fairly high concerning the general synoptic pattern in
the Wed-Sun time frame. It is looking more and more like a high
amplitude mid level trof will be carved out from southeast Canada
southward all the way into the Ms River Valley by the Wed/Thu
period. On east side of the trof, broad swly flow aloft will be
evident. As a sfc low lifts ne along the spine of the Appalachians
Wed, it appears showers will once again overspread most of the
forecast area. Highest rain amounts will probably be over wrn KY and
sw IN. Once the sfc low pulls off to the northeast Wed night, and
the h50 trof axis moves east of the region, rain chcs should
decrease considerably for much of the remainder of the extended.
However, very low height fields and extensive daytime cloudiness
behind the system will likely lead to an extended period of below
normal temperatures. Highs are only expected to reach the 60s most
locations Thu/Fri/Sat.
&&
.AVIATION...
Issued at 636 PM CDT SUN MAY 11 2014
There are just a few isolated showers left across the region early
this evening, and they should dissipate completely in the next
hour or two. KEVV is the most likely terminal to be impacted, but
suspect that those developed on outflow to the south of KEVV and
that they will not survive long north of that boundary.
Outflow has created a light east or east southeast wind at KEVV
and KOWB, but a south wind near 10kts should develop there by late
evening. Elsewhere the south winds will continue through the
night. South southwest winds will gust 20-25kts across the area
Monday.
The area should be completely in the warm sector Monday, and that
should lead to much less convection than today. In fact, there may
not be any across the area. Will keep all of the TAFs dry. Cannot
rule out a periodic lower VFR ceiling Monday, but figure that it
will primarily be a scattered cu deck.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...DB
SHORT TERM...Smith
LONG TERM...GM
AVIATION...DRS
AREA FORECAST DISCUSSION
NWS PADUCAH KY
636 PM CDT Sun May 11 2014
.UPDATE...
Issued at 636 PM CDT SUN MAY 11 2014
The Lake Wind Advisory will expire at 7 PM.
The AVIATION section has been updated for the 00Z TAF issuance.
&&
.SHORT TERM...(Tonight through Tuesday night)
Issued at 317 PM CDT SUN MAY 11 2014
Pockets of surface-based instability continue to expand over the
WFO PAH CWA this afternoon, aided by decent insolation and weak to
moderate directional shear (25-35 knots) aloft (as evidenced by
the anvil rain plumes oriented from northwest to southeast). The
old cold pool has eroded over southeast IL and southwest IN from
the morning convection, so distinct theta-e gradients are in
place. Given the GOES Water Vapor imagery, the moisture gradient
aloft implies a gradient in lapse rates as well, helping to
enhance updrafts. (This is evidenced by the newly organized storms
with hail in Southeast IL).
The 12km RUC also suggests that the expended CAPE along and north
of the implied surface warm frontal reflection arcing from
northwest to southeast through southeast Illinois into northwest
Kentucky. Further expenditure of CAPE through 01z suggests that
the pool of convective instability should drop markedly. In
addition, model heights are expected to rise this evening with a
subtle change in balance takes place between the eastern U.S. ridge
and the center of the sharpening trough over Western Nebraska.
Expect that rain chances will be essentially nil over the entire
WFO PAH CWA by midnight, as the warm frontal boundary moves well
north of the area and shear decreases with time.
As mentioned in yesterday`s discussion, channeled vorticity along
the eastern limb of the trough near the inflection point between
the trough/ridge circulation (cyclonic/anticyclonic flow) will aid
in creating some lift in advance of an approaching moisture plume
from the Gulf of Mexico around daybreak on Monday. This transition
zone for convection will move slowly east through Monday
afternoon, as the main trough actually sharpens and becomes
slightly negatively tilted west of Iowa and Missouri Monday night
into Tuesday morning.
By 09z (4 am CDT) Tuesday morning, the cold front associated with
this trough is expected to move into western sections of the WFO
PAH Forecast area (Southwest IL/Southeast MO). By late evening
Monday and into early Tuesday, the coverage of showers and
thunderstorms should pick up significantly. It is at this time,
that my concern for heavy rain potential will increase, with the
potential for at least minor flooding by daybreak on Tuesday over
parts of Southeast Missouri northeast to the Mississippi River.
QPF values in excess of two inches would not be out of the
question during that time period.
The 12km NAM-WRF is actually suggesting a new closed circulation
will develop at the based of the mean trough over the upper
Midwest, somewhere near the OK/TX panhandles by Tuesday night,
moving into southern Missouri by Wednesday evening. This is similar to
what the ECMWF advertised in the Friday/Saturday model runs. This
will lead to enhanced precipitation, both pre/post frontal as the
frontal boundary remains fixed along the Interstate 57/55 corridor
in Southern IL/Southeast Missouri. Most of the upright
(thunderstorm) instability may be mixed out by Tuesday afternoon
and night, but warm top (satellite reference) convection processes
will likely take over increasing the effectiveness of the
rainfall from Tuesday into Wednesday. There is still some question
with respect to severe potential during this time period, but
heavy rainfall still remains the dominant threat Tuesday into
Wednesday.
.LONG TERM...(Wednesday through Sunday)
Issued at 417 PM CDT SUN MAY 11 2014
Confidence is fairly high concerning the general synoptic pattern in
the Wed-Sun time frame. It is looking more and more like a high
amplitude mid level trof will be carved out from southeast Canada
southward all the way into the Ms River Valley by the Wed/Thu
period. On east side of the trof, broad swly flow aloft will be
evident. As a sfc low lifts ne along the spine of the Appalachians
Wed, it appears showers will once again overspread most of the
forecast area. Highest rain amounts will probably be over wrn KY and
sw IN. Once the sfc low pulls off to the northeast Wed night, and
the h50 trof axis moves east of the region, rain chcs should
decrease considerably for much of the remainder of the extended.
However, very low height fields and extensive daytime cloudiness
behind the system will likely lead to an extended period of below
normal temperatures. Highs are only expected to reach the 60s most
locations Thu/Fri/Sat.
&&
.AVIATION...
Issued at 636 PM CDT SUN MAY 11 2014
There are just a few isolated showers left across the region early
this evening, and they should dissipate completely in the next
hour or two. KEVV is the most likely terminal to be impacted, but
suspect that those developed on outflow to the south of KEVV and
that they will not survive long north of that boundary.
Outflow has created a light east or east southeast wind at KEVV
and KOWB, but a south wind near 10kts should develop there by late
evening. Elsewhere the south winds will continue through the
night. South southwest winds will gust 20-25kts across the area
Monday.
The area should be completely in the warm sector Monday, and that
should lead to much less convection than today. In fact, there may
not be any across the area. Will keep all of the TAFs dry. Cannot
rule out a periodic lower VFR ceiling Monday, but figure that it
will primarily be a scattered cu deck.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...DRS
SHORT TERM...Smith
LONG TERM...GM
AVIATION...DRS
AREA FORECAST DISCUSSION
NWS JACKSON KY
143 PM EDT SAT MAY 10 2014
.UPDATE...
ISSUED AT 1234 PM EDT SAT MAY 10 2014
THE FORECAST HAS BEEN PRETTY MUCH ON TRACK SO FAR TODAY. THE LATEST
MODEL DATA HAS BEEN ABOUT AN HOUR OR SLOW WITH ITS TIMING OF A LINE
OF CONVECTION ACROSS EASTERN KENTUCKY THROUGH EARLY THIS AFTERNOON.
THE INHERITED FORECAST HAS BEEN MUCH CLOSER TO REALITY THAN THE
MODELS IN THAT REGARD SO FAR...SO NO MAJOR CHANGES WERE MADE TO THE
PRECIPITATION PROBABILITIES OR TIMING OF SHOWERS AND STORMS AS THEY
MOVE ACROSS OUR AREA TODAY. SOME MINOR CHANGES WERE MADE TO THE
HOURLY TEMPERATURES AND TODAYS MAX TEMPS BASED ON TRENDS SEEN IN
OBSERVED DATA AND THE INFLUENCE OF PRECIPITATION AT SEVERAL OBSERVING
STATIONS TO THE WEST OF THE WEATHER OFFICE. ALSO REMOVED ANY OUTDATED
MORNING OR AFTERNOON WORDING FROM THE ZONE FORECAST PRODUCT. THE
UPDATED ZONE FORECAST HAS ALREADY BEEN ISSUED.
UPDATE ISSUED AT 803 AM EDT SAT MAY 10 2014
UPPER LEVEL SHORT WAVE CURRENTLY MOVING THROUGH THE MID MISSISSIPPI
VALLEY REGION. COLD FRONTAL BOUNDARY JUST NORTH OF THE OHIO RIVER
WILL ONLY MAKE LITTLE IF ANY PROGRESS SOUTHWARD. WHAT HAS BEEN A
STATIONARY BAND OF SHOWERS AND THUNDERSTORMS OVER WEST CENTRAL KY IS
SHOWING SIGNS OF FINALLY BEING KICKED EASTWARD BY APPROACHING UPPER
LEVEL SHORT WAVE. THIS BAND WILL GRADUALLY SHIFT EASTWARD ACROSS
EASTERN KENTUCKY THROUGH THE DAY.
A COUPLE OF THE MOST RECENT RUNS OF THE HRRR SUGGEST THIS BAND WILL
LIFT NORTHEASTWARD BY 15Z...MISSING MOST OF OUR FORECAST AREA IN THE
PROCESS. AFTER A LULL IN ACTIVITY THE HRRR THEN REDEVELOPS SHOWER
AND THUNDERSTORMS IN A SECOND WAVE WHICH ENTERS INTO OUR AREA FROM
THE WEST BY 17-18Z. SHOWER ACTIVITY LINGERS A BIT LONGER INTO THE
EARLY EVENING AS WELL WHEN COMPARED TO LOWER RESOLUTION MODELS.
CURRENT SWATH OF PRECIPITATION EXTENDS SOUTHWESTWARD...WELL BACK
TOWARDS TEXARKANA. NOT SURE WHAT THE HRRR IS PICKING UP ON BUT
THOUGHTS ARE THAT CURRENT BAND OF SHOWERS WILL NOT LIFT OUT TO THE
NORTHEAST PER THE HRRR. SEEMS MORE LIKELY THE BAND WILL CONTINUE TO
GRADUALLY SHIFT EASTWARD...WITH ADDITIONAL REDEVELOPMENT OF
CLUSTERS/LINE SEGMENTS FURTHER WEST BEHIND THE ORIGINAL BAND AS WE
PROGRESS THROUGH THE DAY. EITHER WAY IT APPEARS LIKELY THAT JUST
ABOUT EVERYONE WILL SEE SOME RAINFALL TODAY...AND HEAR A FEW CLAPS
OF THUNDER FROM TIME TO TIME AS WELL.
WITH SLOW MOVEMENT OF LINE EASTWARD ONLY OTHER CONCERN WOULD BE
POTENTIAL OF TRAINING CELLS WHICH COULD PRODUCE SOME LOCALLY HEAVIER
RAINFALL...AND MINOR FLOODING IN SPOTS. BASED ON KY MESONET RAINFALL
IN GENERAL HAS BEEN ON THE LIGHTER SIDE. BUT A COUPLE OF THE UPSTREAM
GAGES ARE REPORTING TOTALS OVER AN INCH NOW...ONE IS REPORTING AN INCH
AND A HALF. RADAR ESTIMATES ARE EVEN HIGHER IN A FEW LOCATIONS SUCH
AS BUTLER COUNTY WITH ESTIMATES OF BETWEEN 4 AND 7 INCHES OF TOTAL
RAINFALL SO FAR. UNFORTUNATELY THERE IS NO GROUND TRUTH THERE BUT LMK
HAS CONFIRMED THE POTENTIAL BASED ON INCOMING COOP REPORTS. WILL
PASS ON CONCERNS TO FOLLOWING SHIFT. THANKS TO LMK FOR CHAT...
COLLABORATION ON CONCERNS.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 300 AM EDT SAT MAY 10 2014
MODELS ARE IN GOOD AGREEMENT DURING THE SHORT TERM. HOWEVER THERE ARE
DIFFERENCES IN THE DETAILS...PARTICULARLY WITH RESPECT TO TIMING A
BAND OF PRECIPITATION TO OUR WEST THROUGH THE AREA THIS MORNING...
TODAY. SWATH OF SHOWERS AND THUNDERSTORMS TO OUR WEST HAS BEEN
CREEPING SLOWLY EASTWARD BUT SHOULD PICK UP SPEED LATER THIS MORNING
AS AN UPPER LEVEL SHORTWAVE LIFTS THIS BAND EASTWARD WHILE MOVING
ACROSS THE REGION. FORECAST SOUNDINGS ARE MORE STABLE THAN THE
PREVIOUS 12 TO 24 HOURS AND THERE ARE PLENTY OF STRIKES ASSOCIATED
WITH THE BAND...AND EVEN A FEW CLOUD TO CLOUD STRIKES WITH ACTIVITY
ON THE EASTERN FRINGE. WHILE CAN NOT RULE OUT AN ISOLD STRONG/SEVERE
STORM...OVERALL SEVERE THREAT APPEARS MINIMAL.
ATMOSPHERE STABILIZES QUICKLY TONIGHT AS ACTIVITY DIES OUT. AM NOT
REAL IMPRESSED WITH POTENTIAL OF SHOWERS AND THUNDERSTORMS SUNDAY AS
UPPER LEVEL SHORT WAVE RIDGING HELPS BUILD A WEAK CAP ACROSS THE
AREA. THE GFS IS STRONGER THAN THE NAM WITH THIS CAP...PROBABLY DUE
TO THE NAMS TENDENCY TO OVERDO SFC MOISTURE AND CONSEQUENTLY
INSTABILITY. BUT WILL LEAVE A SLIGHT POP IN THE FORECAST FOR GOOD
MEASURE AS THE TRUTH WILL PROBABLY BE SOMEWHERE IN THE MIDDLE...AND
TO MATCH UP BETTER WITH NEIGHBORS.
OTHERWISE...NUDGED TEMPS TOWARDS LATEST BLEND OF MODEL GUIDANCE.
OVERALL TEMPS APPEARED IN GREAT SHAPE.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 300 AM EDT SAT MAY 10 2014
OVERALL...WHILE MODELS CONTINUE TO SHOW INCONSISTENCIES...THE TREND
IS FOR A SLOWER PROGRESSION OF AN UPPER LEVEL TROUGH AS IT PUSHES
INTO THE REGION MID TO LATE WEEK. THE GFS APPEARS TO BE TRENDING
TOWARDS THE SLOWER ECWMF WITH EACH SUBSEQUENT RUN...SO CLEARLY...THE
SLOWER TREND NEEDS TO BE ADDRESSED WITH HIGHER POPS INTO THE END OF
THE WEEK. AS IT STANDS NOW...STRONG RIDGING WILL PERSIST OVER THE
EASTERN US INTO TUESDAY...AND POSSIBLY WEDNESDAY...LEADING TO THE
CONTINUATION OF MILD WEATHER WITH DAYTIME HIGHS INTO THE 80S WITH A
OUTSIDE CHANCE OF AN ISOLATED SHOWER OR STORM EACH AFTERNOON.
HOWEVER...WITH WINDS NEVER COMPLETELY GOING SOUTHWEST...WE MAY KEEP
SOME DOWNSLOPE COMPONENT OF THE WIND...WHICH MAY LIMIT ANY SHOWER OR
STORM POTENTIAL THROUGH AT LEAST TUESDAY NIGHT.
BY WEDNESDAY...AND ESPECIALLY INTO THURSDAY...A SHARP MID/UPPER
LEVEL TROUGH WILL PROGRESS INTO THE OHIO RIVER VALLEY...WITH A
STRONG SURFACE COLD FRONT PUSHING ACROSS THE AREA. STILL PLENTY OF
UNCERTAINTY WITH EXACT TIMING OF THE FRONT...BUT IT DOES APPEAR
AFTER A LONG STRETCH OF MILD WEATHER...WE WILL TURN MUCH COOLER AND
UNSETTLED BY WEEKS END AND INTO NEXT WEEKEND. HIGHS MAY STRUGGLE TO
GET OUT OF THE 50S OR 60S...DEPENDING ON THE DEGREE OF CLOUD COVER
AND PRECIPITATION WITH THE UPPER LEVEL FEATURE. THE UPPER LEVEL LOW
WILL EVENTUALLY CUT OFF SOMEWHERE OVER THE OHIO VALLEY OR GREAT
LAKES REGION...AND EXACT PLACEMENT WILL DETERMINE HOW UNSETTLED THE
WEATHER WILL REMAIN INTO THE WEEKEND. THUS...FOR NOW...WILL TRAIL
OFF POPS AS WE HEAD INTO THE WEEKEND...BUT IF THE UPPER LEVEL LOW
BECOMES MORE ANCHORED OVER EASTERN KENTUCKY...WE COULD BE LOOKING AT
UNSETTLED WEATHER THROUGH THE WEEKEND. STILL PLENTY OF TIME TO IRON
OUT THESE DETAILS. ITS SEEMS THE COOLER WEATHER WILL PERSIST THROUGH
NEXT WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 143 PM EDT SAT MAY 10 2014
A LINE OF SHOWERS AND THUNDERSTORMS WILL CONTINUE TO PUSH ACROSS
EASTERN KENTUCKY THIS AFTERNOON. THIS INITIAL LINE HAS CLEARED THE
AIRPORTS AT JKL...LOZ...AND SME. SJS WILL EXPERIENCE SHOWER AND
STORM ACTIVITY THROUGH 19 OR 20Z BEFORE THINGS BEGIN TO TAPER. AFTER
A BRIEF LULL IN ACTIVITY...ANOTHER AREA OF SHOWERS AND STORMS IS
EXPECTED TO MOVE ACROSS THE AREA LATER THIS AFTERNOON...PERHAPS IN
THE 20 TO 23Z RANGE. THIS SECOND AREA OF PRECIPITATION WILL BEAR
WATCHING TO GET A BETTER HANDLE ON HOW WIDESPREAD IT BECOMES AND IT
EXACT DIRECTION AND SPEED OF MOVEMENT. IN GENERAL THE TAF SITES WILL
EXPERIENCE VFR TO MVFR CONDITIONS FROM ANY EXISTING SHOWERS AND
STORMS AND ANY FOG ASSOCIATED WITH THEM. WORSE CONDITIONS WILL BE
POSSIBLE DURING HEAVY DOWNPOURS AND WINDY CONDITIONS IN ANY
THUNDERSTORMS OR INTENSE RAIN SHOWERS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AR
SHORT TERM...RAY
LONG TERM...KAS
AVIATION...AR
AREA FORECAST DISCUSSION
NWS JACKSON KY
1234 PM EDT SAT MAY 10 2014
.UPDATE...
ISSUED AT 1234 PM EDT SAT MAY 10 2014
THE FORECAST HAS BEEN PRETTY MUCH ON TRACK SO FAR TODAY. THE LATEST
MODEL DATA HAS BEEN ABOUT AN HOUR OR SLOW WITH ITS TIMING OF A LINE
OF CONVECTION ACROSS EASTERN KENTUCKY THROUGH EARLY THIS AFTERNOON.
THE INHERITED FORECAST HAS BEEN MUCH CLOSER TO REALITY THAN THE
MODELS IN THAT REGARD SO FAR...SO NO MAJOR CHANGES WERE MADE TO THE
PRECIPITATION PROBABILITIES OR TIMING OF SHOWERS AND STORMS AS THEY
MOVE ACROSS OUR AREA TODAY. SOME MINOR CHANGES WERE MADE TO THE
HOURLY TEMPERATURES AND TODAYS MAX TEMPS BASED ON TRENDS SEEN IN
OBSERVED DATA AND THE INFLUENCE OF PRECIPITATION AT SEVERAL OBSERVING
STATIONS TO THE WEST OF THE WEATHER OFFICE. ALSO REMOVED ANY OUTDATED
MORNING OR AFTERNOON WORDING FROM THE ZONE FORECAST PRODUCT. THE
UPDATED ZONE FORECAST HAS ALREADY BEEN ISSUED.
UPDATE ISSUED AT 803 AM EDT SAT MAY 10 2014
UPPER LEVEL SHORT WAVE CURRENTLY MOVING THROUGH THE MID MISSISSIPPI
VALLEY REGION. COLD FRONTAL BOUNDARY JUST NORTH OF THE OHIO RIVER
WILL ONLY MAKE LITTLE IF ANY PROGRESS SOUTHWARD. WHAT HAS BEEN A
STATIONARY BAND OF SHOWERS AND THUNDERSTORMS OVER WEST CENTRAL KY IS
SHOWING SIGNS OF FINALLY BEING KICKED EASTWARD BY APPROACHING UPPER
LEVEL SHORT WAVE. THIS BAND WILL GRADUALLY SHIFT EASTWARD ACROSS
EASTERN KENTUCKY THROUGH THE DAY.
A COUPLE OF THE MOST RECENT RUNS OF THE HRRR SUGGEST THIS BAND WILL
LIFT NORTHEASTWARD BY 15Z...MISSING MOST OF OUR FORECAST AREA IN THE
PROCESS. AFTER A LULL IN ACTIVITY THE HRRR THEN REDEVELOPS SHOWER
AND THUNDERSTORMS IN A SECOND WAVE WHICH ENTERS INTO OUR AREA FROM
THE WEST BY 17-18Z. SHOWER ACTIVITY LINGERS A BIT LONGER INTO THE
EARLY EVENING AS WELL WHEN COMPARED TO LOWER RESOLUTION MODELS.
CURRENT SWATH OF PRECIPITATION EXTENDS SOUTHWESTWARD...WELL BACK
TOWARDS TEXARKANA. NOT SURE WHAT THE HRRR IS PICKING UP ON BUT
THOUGHTS ARE THAT CURRENT BAND OF SHOWERS WILL NOT LIFT OUT TO THE
NORTHEAST PER THE HRRR. SEEMS MORE LIKELY THE BAND WILL CONTINUE TO
GRADUALLY SHIFT EASTWARD...WITH ADDITIONAL REDEVELOPMENT OF
CLUSTERS/LINE SEGMENTS FURTHER WEST BEHIND THE ORIGINAL BAND AS WE
PROGRESS THROUGH THE DAY. EITHER WAY IT APPEARS LIKELY THAT JUST
ABOUT EVERYONE WILL SEE SOME RAINFALL TODAY...AND HEAR A FEW CLAPS
OF THUNDER FROM TIME TO TIME AS WELL.
WITH SLOW MOVEMENT OF LINE EASTWARD ONLY OTHER CONCERN WOULD BE
POTENTIAL OF TRAINING CELLS WHICH COULD PRODUCE SOME LOCALLY HEAVIER
RAINFALL...AND MINOR FLOODING IN SPOTS. BASED ON KY MESONET RAINFALL
IN GENERAL HAS BEEN ON THE LIGHTER SIDE. BUT A COUPLE OF THE UPSTREAM
GAGES ARE REPORTING TOTALS OVER AN INCH NOW...ONE IS REPORTING AN INCH
AND A HALF. RADAR ESTIMATES ARE EVEN HIGHER IN A FEW LOCATIONS SUCH
AS BUTLER COUNTY WITH ESTIMATES OF BETWEEN 4 AND 7 INCHES OF TOTAL
RAINFALL SO FAR. UNFORTUNATELY THERE IS NO GROUND TRUTH THERE BUT LMK
HAS CONFIRMED THE POTENTIAL BASED ON INCOMING COOP REPORTS. WILL
PASS ON CONCERNS TO FOLLOWING SHIFT. THANKS TO LMK FOR CHAT...
COLLABORATION ON CONCERNS.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 300 AM EDT SAT MAY 10 2014
MODELS ARE IN GOOD AGREEMENT DURING THE SHORT TERM. HOWEVER THERE ARE
DIFFERENCES IN THE DETAILS...PARTICULARLY WITH RESPECT TO TIMING A
BAND OF PRECIPITATION TO OUR WEST THROUGH THE AREA THIS MORNING...
TODAY. SWATH OF SHOWERS AND THUNDERSTORMS TO OUR WEST HAS BEEN
CREEPING SLOWLY EASTWARD BUT SHOULD PICK UP SPEED LATER THIS MORNING
AS AN UPPER LEVEL SHORTWAVE LIFTS THIS BAND EASTWARD WHILE MOVING
ACROSS THE REGION. FORECAST SOUNDINGS ARE MORE STABLE THAN THE
PREVIOUS 12 TO 24 HOURS AND THERE ARE PLENTY OF STRIKES ASSOCIATED
WITH THE BAND...AND EVEN A FEW CLOUD TO CLOUD STRIKES WITH ACTIVITY
ON THE EASTERN FRINGE. WHILE CAN NOT RULE OUT AN ISOLD STRONG/SEVERE
STORM...OVERALL SEVERE THREAT APPEARS MINIMAL.
ATMOSPHERE STABILIZES QUICKLY TONIGHT AS ACTIVITY DIES OUT. AM NOT
REAL IMPRESSED WITH POTENTIAL OF SHOWERS AND THUNDERSTORMS SUNDAY AS
UPPER LEVEL SHORT WAVE RIDGING HELPS BUILD A WEAK CAP ACROSS THE
AREA. THE GFS IS STRONGER THAN THE NAM WITH THIS CAP...PROBABLY DUE
TO THE NAMS TENDENCY TO OVERDO SFC MOISTURE AND CONSEQUENTLY
INSTABILITY. BUT WILL LEAVE A SLIGHT POP IN THE FORECAST FOR GOOD
MEASURE AS THE TRUTH WILL PROBABLY BE SOMEWHERE IN THE MIDDLE...AND
TO MATCH UP BETTER WITH NEIGHBORS.
OTHERWISE...NUDGED TEMPS TOWARDS LATEST BLEND OF MODEL GUIDANCE.
OVERALL TEMPS APPEARED IN GREAT SHAPE.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 300 AM EDT SAT MAY 10 2014
OVERALL...WHILE MODELS CONTINUE TO SHOW INCONSISTENCIES...THE TREND
IS FOR A SLOWER PROGRESSION OF AN UPPER LEVEL TROUGH AS IT PUSHES
INTO THE REGION MID TO LATE WEEK. THE GFS APPEARS TO BE TRENDING
TOWARDS THE SLOWER ECWMF WITH EACH SUBSEQUENT RUN...SO CLEARLY...THE
SLOWER TREND NEEDS TO BE ADDRESSED WITH HIGHER POPS INTO THE END OF
THE WEEK. AS IT STANDS NOW...STRONG RIDGING WILL PERSIST OVER THE
EASTERN US INTO TUESDAY...AND POSSIBLY WEDNESDAY...LEADING TO THE
CONTINUATION OF MILD WEATHER WITH DAYTIME HIGHS INTO THE 80S WITH A
OUTSIDE CHANCE OF AN ISOLATED SHOWER OR STORM EACH AFTERNOON.
HOWEVER...WITH WINDS NEVER COMPLETELY GOING SOUTHWEST...WE MAY KEEP
SOME DOWNSLOPE COMPONENT OF THE WIND...WHICH MAY LIMIT ANY SHOWER OR
STORM POTENTIAL THROUGH AT LEAST TUESDAY NIGHT.
BY WEDNESDAY...AND ESPECIALLY INTO THURSDAY...A SHARP MID/UPPER
LEVEL TROUGH WILL PROGRESS INTO THE OHIO RIVER VALLEY...WITH A
STRONG SURFACE COLD FRONT PUSHING ACROSS THE AREA. STILL PLENTY OF
UNCERTAINTY WITH EXACT TIMING OF THE FRONT...BUT IT DOES APPEAR
AFTER A LONG STRETCH OF MILD WEATHER...WE WILL TURN MUCH COOLER AND
UNSETTLED BY WEEKS END AND INTO NEXT WEEKEND. HIGHS MAY STRUGGLE TO
GET OUT OF THE 50S OR 60S...DEPENDING ON THE DEGREE OF CLOUD COVER
AND PRECIPITATION WITH THE UPPER LEVEL FEATURE. THE UPPER LEVEL LOW
WILL EVENTUALLY CUT OFF SOMEWHERE OVER THE OHIO VALLEY OR GREAT
LAKES REGION...AND EXACT PLACEMENT WILL DETERMINE HOW UNSETTLED THE
WEATHER WILL REMAIN INTO THE WEEKEND. THUS...FOR NOW...WILL TRAIL
OFF POPS AS WE HEAD INTO THE WEEKEND...BUT IF THE UPPER LEVEL LOW
BECOMES MORE ANCHORED OVER EASTERN KENTUCKY...WE COULD BE LOOKING AT
UNSETTLED WEATHER THROUGH THE WEEKEND. STILL PLENTY OF TIME TO IRON
OUT THESE DETAILS. ITS SEEMS THE COOLER WEATHER WILL PERSIST THROUGH
NEXT WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 803 AM EDT SAT MAY 10 2014
MODELS AND GUIDANCE ARE HOLDING OFF ON THE BULK OF SHOWER AND
THUNDERSTORM ACTIVITY UNTIL LATER THIS MORNING AND MID DAY AS AN
UPPER LEVEL DISTURBANCE PASSES THROUGH THE REGION TODAY. TRIED TO
TIME ONSET OF SHOWERS INTO THE AREA BASED ON MOST RECENT HIGH
RESOLUTION MODELS AND EXTRAPOLATION OF CURRENT BAND INTO THE AREA.
FEEL THERE WILL BE A 4 TO 6 HOUR WINDOW OF SHOWER AND THUNDERSTORM
ACTIVITY AT EACH TERMINAL CENTERED SOMEWHERE AROUND 17-20Z. IN
GENERAL CIGS HAVE BEEN DROPPING TO ABOUT 3K FT AND VSBYS TO AROUND
1-2SM WITH PASSING THUNDERSTORM CELLS. CONDITIONS WOULD BE ONLY
TEMPORARY WITH PASSING STORMS. WILL AMEND TAFS FOR TEMPO GROUPS ONCE
WE ARE ABLE TO GET BETTER TIMING OF ANY STORMS ON STATION.
SURFACE FRONTAL BOUNDARY WILL WASH OUT JUST TO OUR NORTH. WITH RAIN
EXPECTED TODAY AND NO CLEAR PUSH OF DRIER AIR INTO OUR FORECAST AREA
HELD ONTO SOME LIGHT MVFR MIST/FOG IN THE FORECAST AFTER 0Z. WINDS
WILL BE SOUTHERLY AND LIGHT...WITH A TENDENCY TO INCREASE TO AROUND
10 KTS AND BECOME A BIT MORE WESTERLY LATER THIS AFTERNOON.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AR
SHORT TERM...RAY
LONG TERM...KAS
AVIATION...RAY
AREA FORECAST DISCUSSION
NWS JACKSON KY
803 AM EDT SAT MAY 10 2014
.UPDATE...
ISSUED AT 803 AM EDT SAT MAY 10 2014
UPPER LEVEL SHORT WAVE CURRENTLY MOVING THROUGH THE MID MISSISSIPPI
VALLEY REGION. COLD FRONTAL BOUNDARY JUST NORTH OF THE OHIO RIVER
WILL ONLY MAKE LITTLE IF ANY PROGRESS SOUTHWARD. WHAT HAS BEEN A
STATIONARY BAND OF SHOWERS AND THUNDERSTORMS OVER WEST CENTRAL KY IS
SHOWING SIGNS OF FINALLY BEING KICKED EASTWARD BY APPROACHING UPPER
LEVEL SHORT WAVE. THIS BAND WILL GRADUALLY SHIFT EASTWARD ACROSS
EASTERN KENTUCKY THROUGH THE DAY.
A COUPLE OF THE MOST RECENT RUNS OF THE HRRR SUGGEST THIS BAND WILL
LIFT NORTHEASTWARD BY 15Z...MISSING MOST OF OUR FORECAST AREA IN THE
PROCESS. AFTER A LULL IN ACTIVITY THE HRRR THEN REDEVELOPS SHOWER
AND THUNDERSTORMS IN A SECOND WAVE WHICH ENTERS INTO OUR AREA FROM
THE WEST BY 17-18Z. SHOWER ACTIVITY LINGERS A BIT LONGER INTO THE
EARLY EVENING AS WELL WHEN COMPARED TO LOWER RESOLUTION MODELS.
CURRENT SWATH OF PRECIPITATION EXTENDS SOUTHWESTWARD...WELL BACK
TOWARDS TEXARKANA. NOT SURE WHAT THE HRRR IS PICKING UP ON BUT
THOUGHTS ARE THAT CURRENT BAND OF SHOWERS WILL NOT LIFT OUT TO THE
NORTHEAST PER THE HRRR. SEEMS MORE LIKELY THE BAND WILL CONTINUE TO
GRADUALLY SHIFT EASTWARD...WITH ADDITIONAL REDEVELOPMENT OF
CLUSTERS/LINE SEGMENTS FURTHER WEST BEHIND THE ORIGINAL BAND AS WE
PROGRESS THROUGH THE DAY. EITHER WAY IT APPEARS LIKELY THAT JUST
ABOUT EVERYONE WILL SEE SOME RAINFALL TODAY...AND HEAR A FEW CLAPS
OF THUNDER FROM TIME TO TIME AS WELL.
WITH SLOW MOVEMENT OF LINE EASTWARD ONLY OTHER CONCERN WOULD BE
POTENTIAL OF TRAINING CELLS WHICH COULD PRODUCE SOME LOCALLY HEAVIER
RAINFALL...AND MINOR FLOODING IN SPOTS. BASED ON KY MESONET RAINFALL
IN GENERAL HAS BEEN ON THE LIGHTER SIDE. BUT A COUPLE OF THE UPSTREAM
GAGES ARE REPORTING TOTALS OVER AN INCH NOW...ONE IS REPORTING AN INCH
AND A HALF. RADAR ESTIMATES ARE EVEN HIGHER IN A FEW LOCATIONS SUCH
AS BUTLER COUNTY WITH ESTIMATES OF BETWEEN 4 AND 7 INCHES OF TOTAL
RAINFALL SO FAR. UNFORTUNATELY THERE IS NO GROUND TRUTH THERE BUT LMK
HAS CONFIRMED THE POTENTIAL BASED ON INCOMING COOP REPORTS. WILL
PASS ON CONCERNS TO FOLLOWING SHIFT. THANKS TO LMK FOR CHAT...
COLLABORATION ON CONCERNS.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 300 AM EDT SAT MAY 10 2014
MODELS ARE IN GOOD AGREEMENT DURING THE SHORT TERM. HOWEVER THERE ARE
DIFFERENCES IN THE DETAILS...PARTICULARLY WITH RESPECT TO TIMING A
BAND OF PRECIPITATION TO OUR WEST THROUGH THE AREA THIS MORNING...
TODAY. SWATH OF SHOWERS AND THUNDERSTORMS TO OUR WEST HAS BEEN
CREEPING SLOWLY EASTWARD BUT SHOULD PICK UP SPEED LATER THIS MORNING
AS AN UPPER LEVEL SHORTWAVE LIFTS THIS BAND EASTWARD WHILE MOVING
ACROSS THE REGION. FORECAST SOUNDINGS ARE MORE STABLE THAN THE
PREVIOUS 12 TO 24 HOURS AND THERE ARE PLENTY OF STRIKES ASSOCIATED
WITH THE BAND...AND EVEN A FEW CLOUD TO CLOUD STRIKES WITH ACTIVITY
ON THE EASTERN FRINGE. WHILE CAN NOT RULE OUT AN ISOLD STRONG/SEVERE
STORM...OVERALL SEVERE THREAT APPEARS MINIMAL.
ATMOSPHERE STABILIZES QUICKLY TONIGHT AS ACTIVITY DIES OUT. AM NOT
REAL IMPRESSED WITH POTENTIAL OF SHOWERS AND THUNDERSTORMS SUNDAY AS
UPPER LEVEL SHORT WAVE RIDGING HELPS BUILD A WEAK CAP ACROSS THE
AREA. THE GFS IS STRONGER THAN THE NAM WITH THIS CAP...PROBABLY DUE
TO THE NAMS TENDENCY TO OVERDO SFC MOISTURE AND CONSEQUENTLY
INSTABILITY. BUT WILL LEAVE A SLIGHT POP IN THE FORECAST FOR GOOD
MEASURE AS THE TRUTH WILL PROBABLY BE SOMEWHERE IN THE MIDDLE...AND
TO MATCH UP BETTER WITH NEIGHBORS.
OTHERWISE...NUDGED TEMPS TOWARDS LATEST BLEND OF MODEL GUIDANCE.
OVERALL TEMPS APPEARED IN GREAT SHAPE.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 300 AM EDT SAT MAY 10 2014
OVERALL...WHILE MODELS CONTINUE TO SHOW INCONSISTENCIES...THE TREND
IS FOR A SLOWER PROGRESSION OF AN UPPER LEVEL TROUGH AS IT PUSHES
INTO THE REGION MID TO LATE WEEK. THE GFS APPEARS TO BE TRENDING
TOWARDS THE SLOWER ECWMF WITH EACH SUBSEQUENT RUN...SO CLEARLY...THE
SLOWER TREND NEEDS TO BE ADDRESSED WITH HIGHER POPS INTO THE END OF
THE WEEK. AS IT STANDS NOW...STRONG RIDGING WILL PERSIST OVER THE
EASTERN US INTO TUESDAY...AND POSSIBLY WEDNESDAY...LEADING TO THE
CONTINUATION OF MILD WEATHER WITH DAYTIME HIGHS INTO THE 80S WITH A
OUTSIDE CHANCE OF AN ISOLATED SHOWER OR STORM EACH AFTERNOON.
HOWEVER...WITH WINDS NEVER COMPLETELY GOING SOUTHWEST...WE MAY KEEP
SOME DOWNSLOPE COMPONENT OF THE WIND...WHICH MAY LIMIT ANY SHOWER OR
STORM POTENTIAL THROUGH AT LEAST TUESDAY NIGHT.
BY WEDNESDAY...AND ESPECIALLY INTO THURSDAY...A SHARP MID/UPPER
LEVEL TROUGH WILL PROGRESS INTO THE OHIO RIVER VALLEY...WITH A
STRONG SURFACE COLD FRONT PUSHING ACROSS THE AREA. STILL PLENTY OF
UNCERTAINTY WITH EXACT TIMING OF THE FRONT...BUT IT DOES APPEAR
AFTER A LONG STRETCH OF MILD WEATHER...WE WILL TURN MUCH COOLER AND
UNSETTLED BY WEEKS END AND INTO NEXT WEEKEND. HIGHS MAY STRUGGLE TO
GET OUT OF THE 50S OR 60S...DEPENDING ON THE DEGREE OF CLOUD COVER
AND PRECIPITATION WITH THE UPPER LEVEL FEATURE. THE UPPER LEVEL LOW
WILL EVENTUALLY CUT OFF SOMEWHERE OVER THE OHIO VALLEY OR GREAT
LAKES REGION...AND EXACT PLACEMENT WILL DETERMINE HOW UNSETTLED THE
WEATHER WILL REMAIN INTO THE WEEKEND. THUS...FOR NOW...WILL TRAIL
OFF POPS AS WE HEAD INTO THE WEEKEND...BUT IF THE UPPER LEVEL LOW
BECOMES MORE ANCHORED OVER EASTERN KENTUCKY...WE COULD BE LOOKING AT
UNSETTLED WEATHER THROUGH THE WEEKEND. STILL PLENTY OF TIME TO IRON
OUT THESE DETAILS. ITS SEEMS THE COOLER WEATHER WILL PERSIST THROUGH
NEXT WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 803 AM EDT SAT MAY 10 2014
MODELS AND GUIDANCE ARE HOLDING OFF ON THE BULK OF SHOWER AND
THUNDERSTORM ACTIVITY UNTIL LATER THIS MORNING AND MID DAY AS AN
UPPER LEVEL DISTURBANCE PASSES THROUGH THE REGION TODAY. TRIED TO
TIME ONSET OF SHOWERS INTO THE AREA BASED ON MOST RECENT HIGH
RESOLUTION MODELS AND EXTRAPOLATION OF CURRENT BAND INTO THE AREA.
FEEL THERE WILL BE A 4 TO 6 HOUR WINDOW OF SHOWER AND THUNDERSTORM
ACTIVITY AT EACH TERMINAL CENTERED SOMEWHERE AROUND 17-20Z. IN
GENERAL CIGS HAVE BEEN DROPPING TO ABOUT 3K FT AND VSBYS TO AROUND
1-2SM WITH PASSING THUNDERSTORM CELLS. CONDITIONS WOULD BE ONLY
TEMPORARY WITH PASSING STORMS. WILL AMEND TAFS FOR TEMPO GROUPS ONCE
WE ARE ABLE TO GET BETTER TIMING OF ANY STORMS ON STATION.
SURFACE FRONTAL BOUNDARY WILL WASH OUT JUST TO OUR NORTH. WITH RAIN
EXPECTED TODAY AND NO CLEAR PUSH OF DRIER AIR INTO OUR FORECAST AREA
HELD ONTO SOME LIGHT MVFR MIST/FOG IN THE FORECAST AFTER 0Z. WINDS
WILL BE SOUTHERLY AND LIGHT...WITH A TENDENCY TO INCREASE TO AROUND
10 KTS AND BECOME A BIT MORE WESTERLY LATER THIS AFTERNOON.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...RAY
SHORT TERM...RAY
LONG TERM...KAS
AVIATION...RAY
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
109 AM EDT Sat May 10 2014
...Updated Aviation Discussion...
...Forecast Update...
Issued at 1130 PM EDT Fri May 9 2014
Did an update to increase POPs west of I-65 overnight. Models
aren`t handling this evening`s convection very well. Storms
continue to re-generate from SE Missouri through south
Indiana/central KY. This is courtesy of multiple waves riding
northeast along the south side of an upper trough to our north. The
associate sfc boundary still sits well to our west over central
MO/IL. Therefore, feel scattered shower/storms will continue
overnight. A few high-res models and the 18Z/0Z NAM runs indicate a
more solid area of showers/storms may form in our area (mainly over
KY) late tonight into tomorrow morning. Will continue 60-70% POPs
during that time frame. Think that storms will be mostly sub-severe
overnight in an elevated environment. Pea size hail and perhaps a
wind gust up to 40 mph may be possible in the strongest storms.
Only made minor tweaks to temps/dewpts. Low temps will be in the
lower 60s overnight.
Issued at 810 PM EDT Fri May 9 2014
Did a quick update to better time POPs as the line of showers and
storms moves through the region. The line has become pretty solid
as far as coverage goes, but overall strength of storms has
declined. The strongest storms will likely contain 35 to 45 mph
wind gusts and perhaps some small hail. However, the convection is
moving into a more unfavorable environment so do expect storms to
continue to decrease in strength as the evening wears on. This
round of storms should pass through the area by midnight. We`ll see
a break in convection with another round looking likely late tonight
into tomorrow morning.
.SHORT TERM (Now through Saturday Night)...
Issued at 305 PM EDT Fri May 9 2014
In the near term, rainfall from this morning continues to move NE
but is still hanging in there over east-central KY. The rain will
exit our forecast area in the next 1-2 hrs. Otherwise, conditions
are dry with ample cloud cover over the rest of the region, with
some cumulus clouds now starting to emerge with modest diurnal
warming and decent low-level moisture. Nevertheless, the atmosphere
remains relatively stable at this time, as evidenced by current SPC
mesoanalysis. Thus, expect mainly rain free weather for the next few
hours over central KY and south-central IN as temperatures top out
thru the 70s to around 80 west.
Meanwhile, convection continues to slowly develop along and ahead of
a low-level frontal boundary and confluent zone from southwest IL
into south-central MO. Latest SPC mesoanalysis shows an axis of -4
to -6 surface-based LI values and around 1000 J/kg CAPE in this
axis. All short-range models and the latest HRRR and SPC SREF
suggest this convection will continue to develop and expand E-NE
late this afternoon and evening. Model soundings in our area show
lapse rates increasing late this afternoon and evening, especially
aloft resulting in a more conducive environment in time to develop
and maintain convection within. As a result, will ramp up POPs this
evening, first over south-central IN and northwest KY, then eastward
later tonight.
The best chances for severe storms are to our west in the area of
the current SPC severe thunderstorm watch, enhanced by good
instability and deep-layer speed shear (with a strong upper jet
advancing eastward). As the storms move east later tonight, they may
have a tendency to become slightly elevated with modest nocturnal
cooling over our area. Nevertheless, the boundary layer may stay
adequately mixed to allow some downward momentum transport from the
strongest cells to produce isolated strong or damaging winds, mainly
along and west of the I-65 corridor. After the storms move through,
can`t totally rule out additional scattered showers and isolated
thunderstorms well after midnight and into Saturday morning as a
mid-level shortwave approaches.
During the day Saturday, the shortwave will pass through our area.
This could continue the chance for scattered showers and storms over
eastern and southern forecast area in the morning, but should
effectively clear things out later in the day. As a result, much of
the afternoon should be precipitation free with temperatures rising
through the 70s. If enough sunshine occurs in the afternoon, could
see around 80 or lower 80s in western half of forecast area.
Air mass will begin to destabilize again Saturday afternoon in the
wake of the morning showers, but forcing should be quite limited
in the wake of the morning shortwave. Therefore, expect only
isolated cell redevelopment by late afternoon mainly over western
and northern areas of forecast area. This activity could become a
little more prevalent, especially northern half of forecast area,
Saturday night if a model weak signal of another approaching
shortwave proves correct.
.LONG TERM (Sunday through Friday)...
Issued at 250 PM EDT Fri May 9 2014
The long term period will be fairly active with multiple chances for
showers and thunderstorms. In addition, a big shift in the upper air
pattern will bring much cooler temperatures by the end of the next
work week.
For Sunday through Monday ridging will be building aloft. At the
surface, high pressure will be centered off the east coast.
Southerly winds on the back side of this high pressure will usher in
warm and moist air to the lower Ohio Valley. Temperatures on Sunday
will warm into the lower to mid 80s. Soundings show surface based
instability developing during the afternoon and little to no cap
across the area. However, with the lack of a trigger, storms look to
remain scattered in nature and should mostly dissipate during the
evening hours. For Monday soundings show more of a cap in place, so
rain chances look to be less than Sunday. However, isolated to
scattered showers and storms will still be possible. Highs will be
in the mid 80s.
A cold front will approach and move through the area during the
Tuesday through Wednesday time frame. There is still quite a bit of
discrepancy in the timing of this frontal passage. Thus, have gone
with pops over a wider time frame than is expected with the frontal
passage to account for uncertainty. For now, it looks like
Tuesday/Tuesday night will be the best chance for showers and
storms. However, if slower solutions pan out, chances will linger
into Wednesday.
The timing issue with the front will also have quite an impact on
temperatures mid week as a trough will move in behind this system.
This will usher in cooler air for the end of the week. Highs
Thursday and Friday will be in the lower to mid 60s with lows in the
upper 40s. There may be a slight chance of rain toward the end of
the long term as a weak disturbance moves through the flow aloft,
but timing with these is usually fairly questionable this far out.
&&
.AVIATION (06Z TAF Update)...
Issued at 107 AM EDT Sat May 10 2014
A rather complex TAF forecast is in store, as several boundaries
from earlier convection are currently sparking convection. Over the
next couple of hours, convection should remain scattered in nature.
However, there is a subtle signal in guidance that convection will
increase before dawn as another shortwave trough ejects north into
the region. The best coverage of this precip looks to be across
KBWG and KLEX. KSDF looks to remain on the northern edge of the
better coverage of showers and embedded thunderstorms, but certainly
they cannot be ruled out at any time overnight into Saturday
morning. MVFR ceilings will likely move into all terminals
overnight, especially as the steadier precipitation pushes in just
before dawn.
After more widespread coverage of showers/storms Saturday morning,
they should become more isolated in nature by the afternoon hours.
Winds will be out of the SSW at 10-15 knots.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Update.........AMS
Short Term.....TWF
Long Term......EER
Aviation.......KJD
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1028 PM CDT SUN MAY 11 2014
.DISCUSSION...
INTERESTING FORECAST UPDATE FOR THE REMAINDER OF THE OVERNIGHT
HOURS. CONVECTION ACROSS NATCHITOCHES PARISH HAS FINALLY
DISSIPATED BUT RENEWED CONVECTION CONTINUES TO DEVELOP ACROSS DEEP
EAST TEXAS AND SHOWS SIGNS OF EXPANDING NORTH AND WEST. THIS WOULD
MAKE SENSE AS LATEST RUN OF THE HRRR SUGGESTS INCREASING CAPE
OVERNIGHT ACROSS OUR WESTERN HALF. CONVECTION IS PROBABLY BEING
AIDED BY A 50KT LOW LEVEL JET OFF SHV`S WSR-88D VAD WIND PROFILER.
A QUICK LOOK AT ISENTROPIC SFCS NEAR OR SLIGHTLY ABOVE THE 930MB
LEVEL SUGGEST A CONTINUATION OF ISENTROPIC LIFT WITH LOW CONDENSATION
PRESSURE DEFICITS ACROSS OUR WESTERN HALF AS WELL.
HAVING SAID ALL THIS...FOR THE UPDATE...WILL CONTINUE WITH A
SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS THROUGH THE REMAINDER
OF THE NIGHT ACROSS ALL ZONES...EVEN THOUGH I`M A LITTLE MORE
CERTAIN OF THE BEST COVERAGE BEING ACROSS OUR WESTERN ZONES WHERE
THE INSTABILITY OVERNIGHT WILL BE GREATER.
TEMPERATURES AS OF 03Z ARE RUNNING A LITTLE WARMER THAN THIS TIME
AND GIVEN THE QUICK RETURN TO THE LOW LEVEL CLOUD COVER ALREADY
SEEN ON IR IMAGERY ALONG AND SOUTH OF A LFK...SHV...MLU
LINE...ANOTHER WARM NIGHT IS IN STORE ACROSS THE REGION. HOURLY
TEMPS ARE ALMOST DEAD ON WITH FCST HOURLY TEMPS AND OVERNIGHT MINS
ARE FORECAST TO BE SOME 2 TO 3 DEGREES WARMER THAN LAST NIGHT. FOR
THAT REASON...TEMPS APPEAR TO BE IN PRETTY GOOD SHAPE.
EXPECTING SOUTHEAST WINDS NEAR 10 TO 15 MPH AREAWIDE WITH AN
OCCASIONAL GUST FROM TIME TO TIME GIVEN THE STRONG PRESSURE
GRADIENT IN THE LOWER LEVELS.
ONLY UPDATE NECESSARY APPEAR TO BE AN EXTENSION TO THE POP
FORECAST SPATIALLY BUT OTHERWISE...NO OTHER CHANGES ARE NECESSARY.
FCST UPDATE OUT SHORTLY...13.
&&
.PREV DISCUSSION... /ISSUED 658 PM CDT SUN MAY 11 2014/
AVIATION...
FOR THE 12/00Z TAF ISSUE...EXPECT VFR FLIGHT WEATHER TO BEGIN THE
24 HOUR FORECAST PERIOD MOST LOCATIONS. HOWEVER...THROUGH 02Z...
ISOLATED TSTMS WILL BE ONGOING IN NORTH CENTRAL LOUISIANA INTO
SOUTH CENTRAL ARKANSAS. THIS CONVECTION WILL BRING MODERATE
TO SEVERE TURBULENCE AND SURFACE WIND GUSTS BETWEEN 30 AND 40 KTS.
AFTER 06Z...MVFR TO IFR CONDITIONS WILL BEGIN TO RETURN...AS
SOUTHERLY WIND CONTINUES TO BRING MOISTURE INTO THE REGION. EXPECT
THE FIRST CIGS AROUND 2 KFT...HOWEVER BY 09Z AND CONTINUING UNTIL
14Z...IFR CIGS BETWEEN 5 HUNDRED AND 1 KFT WILL BE COMMON ACROSS
THE REGION. LIGHT FOG WILL ACCOMPANY THE LOWER CIGS AT A FEW
TERMINALS WITH VSBYS BETWEEN 3 AND 5 MILES. VFR SHOULD RETURN TO
MOST LOCATIONS BY 15Z...WITH CIGS 3 TO 4 KFT. ISOLATED TSTMS WILL
DEVELOP WITH AFTERNOON HEATING...BECOMING MORE NUMEROUS WESTERN
AREAS AFTER 21Z. SURFACE WIND SOUTH 5 TO 10 KTS TONIGHT...INCREASING
UP TO 15 KTS WITH GUSTS 20 TO 25 KTS AFTER 14Z. /14/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 73 86 67 79 57 / 20 50 60 70 50
MLU 70 86 67 83 60 / 20 50 50 60 50
DEQ 71 82 60 70 51 / 20 60 80 70 50
TXK 71 83 62 72 54 / 20 60 80 70 50
ELD 70 84 66 78 55 / 20 50 60 70 50
TYR 73 84 61 70 52 / 20 60 80 60 50
GGG 73 85 65 74 54 / 20 50 80 70 50
LFK 73 87 69 79 55 / 20 50 60 70 50
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
13
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
1238 PM CDT SAT MAY 10 2014
.AVIATION...
VFR CONDITIONS EXPECTED TODAY AND THIS EVENING WITH HIGH BASED
CEILINGS EVENTUALLY CLEARING FROM WEST TO EAST. MARINE LAYER
CLOUDS LIKELY TO DEVELOP OVERNIGHT TO BRING A BRIEF PERIOD OF MVFR
CIGS BASED AROUND 1500 FT THAT MIXES OUT AFTER 14Z. AIR MASS HAS
BECOME LESS UNSTABLE AND CONVECTION SHOULD REMAIN LESS THAN 30
PERCENT COVERAGE/CONFIDENCE TO MENTION IN ANY TAF LOCATION. 24/RR
&&
.PREV DISCUSSION... /ISSUED 1011 AM CDT SAT MAY 10 2014/
SOUNDING DISCUSSION...
PW VALUES HAVE DROPPED FROM 2.17" AT 00Z(1900CST YESTERDAY) TO
1.68" AT 12Z THIS MORNING. THIS IS EVIDENT FROM THE DRY LAYER THAT
HAS DEVELOPED BETWEEN THE SFC UP TO 850MB. YESTERDAYS SOUNDING
SHOWED A VERY SHALLOW COOL POOL THAT WAS RESPONSIBLE FOR GIVING
THE MUCH NEEDED INITIAL LIFT TO THE SFC PARCELS. ONCE PARCELS
REACHED ~975MB OR ~1100 FEET...THE PARCEL BECAME MOIST ADIABATIC
ALL THE WAY UP TO 300MB AND AT 14.5 G/KG MIXING RATIO(YES 14.5)...THESE
VARIABLES POINT TO A VERY TROPICAL AIR MASS WHICH MAY HAVE CAME
FROM THE DEEP MOISTURE LOADING FROM THE OLD TROPICAL SYSTEM OFF
THE WEST COAST OF MEXICO. THIS MORNINGS SOUNDING DOES NOT SHOW
THAT DEPTH OF MOISTURE ANY LONGER.
PREV DISCUSSION... /ISSUED 856 AM CDT SAT MAY 10 2014/
UPDATE...
SENDING UPDATED ZONES TO REMOVE HEADLINES AT TOP OF THE HOUR. FLASH FLOOD
WATCH ALLOWED TO EXPRIRE AT 9 AM AS SCHEDULED. 24/RR
PREV DISCUSSION... /ISSUED 342 AM CDT SAT MAY 10 2014/
SYNOPSIS...
SURFACE LOW CENTERED OVER EASTERN ONTARIO WITH A COLD FRONT
EXTENDING SOUTHWARD AND SOUTHWESTWARD THROUGH THE OHIO VALLEY AND
INTO SOUTH CENTRAL MISSOURI WHERE IT HAS BECOME STATIONARY. LARGE
SHIELD OF LIGHT TO MODERATE RAINFALL OVER NORTHERN GULF COAST
REGION IS GRADUALLY ERODING AS OUTFLOW BOUNDARY FROM EARLIER
CONVECTION HELPS CUT OFF MOISTURE SOURCE. TEMPS SITTING IN THE
MID TO UPPER 60S WITH DEWPOINTS IN THE LOW TO MID 60S.
DISCUSSION...
HAVE CHOSEN TO LEAVE THE FLASH FLOOD WATCH IN PLACE JUST IN CASE
OF ANY UNEXPECTED REDEVELOPMENT OF HEAVIER STORMS DURING THE NEXT
FEW HOURS. THE GROUND IS NOW SATURATED ACROSS MOST OF THE AREA AND
RAINFALL RATES IN EXCESS OF 2 INCHES PER HOUR HAVE BEEN COMMON
WITH THIS AIR MASS. ANY HEAVIER STORMS THAT REDEVELOP WILL EASILY
PRODUCE SIMILAR RAINFALL RATES AND OVERWHELM NATURAL DRAINAGE.
ASSUMING MOTHER NATURE COOPERATES...THE FLASH FLOOD THREAT SHOULD
CONTINUE DIMINISHING THROUGH THE MORNING AND AN EXTENSION TO THE
FLASH FLOOD WATCH IS NOT CURRENTLY ANTICIPATED.
CONFIDENCE IN SHORT TERM FORECAST IS LOWER THAN NORMAL WITH FAIRLY
SIGNIFICANT DIFFERENCES IN THE MODELS CONCERNING RAINFALL. EURO IS
GENERALLY THE WETTEST OF THE MODELS WITH THE NAM BEING THE DRIEST
AND THE GFS SOMEWHERE IN THE MIDDLE...THOUGH EVEN GFS ENSEMBLE
MEMBERS GENERALLY INDICATE A 30 PERCENT SPREAD IN POP FORECASTS AT
ANY GIVEN LOCATION FOR TODAY. GIVEN RECENT RADAR TRENDS...AM
LEANING TOWARD THE LOWER POP SOLUTIONS FOR TODAY. THIS IS ALSO
SUPPORTED BY THE LATEST HRRR RUNS WHICH HAVE BEEN FAIRLY ACCURATE
AND CONSISTENT OVER THE PAST 8 RUNS. AM NOT QUITE AS AGGRESSIVE
CLEARING THE AREA OUT AS THE HRRR WHICH CUTS OFF NEARLY ALL
RAINFALL BY 15Z WITH LITTLE REDEVELOPMENT INDICATED DURING THE
EARLY AFTERNOON HOURS. THOUGH THERE MAY BE A SIGNIFICANT BREAK IN
THE RAIN...ESPECIALLY DURING THE LATE MORNING...BELIEVE THERE IS
ENOUGH MOISTURE IN PLACE TO SEE ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS DURING THE AFTERNOON HOURS SIMPLY DUE TO LIFT
ASSOCIATED WITH DAYTIME HEATING.
DEEP MOISTURE WILL REMAIN IN PLACE NEXT FEW DAYS AS PERSISTENT
ONSHORE FLOW CONTINUES TO PUMP IN WARM AND MOIST AIR FROM THE
GULF OF MEXICO. WITH WEAK AND BROAD RIDGING ALOFT AND A LACK OF
ANY LARGE SCALE FORCING MECHANISM...WILL BE RELYING ON DIURNAL
HEATING TO PROVIDE THE NECESSARY LIFT FOR CONVECTION. WITH TEMPS
FORECAST TO TOP OUT IN THE MID TO UPPER 80S EACH DAY...THAT SHOULD
BE ENOUGH TO FIRE OFF ISOLATED TO WIDELY SCATTERED SHOWERS AND
THUNDERSTORMS SO AM CARRYING SLIGHT CHANCE TO LOW END CHANCE POPS
EACH DAY THROUGH TUESDAY.
BY TUESDAY...STRONG UPPER TROUGH WILL BE DIGGING INTO THE SOUTHERN
PLAINS FORCING A COLD FRONT TOWARD THE AREA. MODELS CONTINUE TO
STRUGGLE WITH TIMING OF THIS FRONT AND THERE IS STILL ABOUT A 12
TO 18 HOUR DIFFERENCE IN THE TIMING OF THE LOCAL FROPA. THE GFS
CONTINUES TO BE THE MORE PROGRESSIVE OF THE MODELS WITH THE EURO
BEING THE SLOWER SOLUTION. HAVE GENERALLY GONE WITH A BLEND...
WHICH RESULTS IN A FROPA EARLY WEDNESDAY. GFS AND EURO BOTH AGREE
THAT WE SHOULD SEE SOME DECENT COOLING BEHIND THIS FRONT WITH
TEMPS DROPPING WELL BELOW NORMAL DURING THE OVERNIGHT HOURS
WEDNESDAY NIGHT AND THURSDAY NIGHT. HIGHS WILL ALSO DROP SEVERAL
DEGREES AND SHOULD TOP OUT IN THE UPPER 70S OR LOWER 80S WEDNESDAY
AND THURSDAY. THESE COOLER TEMPS WILL ALSO BE ACCOMPANIED BY LOWER
DEWPOINTS WHICH SHOULD MAKE THE AFTERNOONS DOWNRIGHT PLEASANT LATE
IN THE WEEK IF THE FORECAST PANS OUT.
AVIATION...
WIDESPREAD MAINLY LIGHT TO MODERATE RAIN CONTINUES FALL ACROSS MOST
OF THE FORECAST AREA EARLY THIS MORNING...AFFECTING ALL OF THE
TERMINALS. MVFR CONDITIONS WILL BE THE RULE THROUGH THE EARLY
MORNING HOURS WITH VFR CONDITIONS PREVAILING FROM MID MORNING ON AS
THE RAINFALL ACROSS THE AREA DIMINISHES.
MARINE...
A RIDGE OF HIGH PRESSURE EXTENDING ACROSS THE COASTAL WATERS WILL
PERSIST THROUGH THE WEEKEND BEFORE SHIFTING EAST EARLY NEXT WEEK. A
COLD FRONT WILL THEN PUSH ACROSS THE COASTAL WATERS TUESDAY NIGHT.
MODERATE ONSHORE FLOW WILL GENERALLY PREVAIL THROUGH THE PERIOD IN
ADVANCE OF THE COLD FRONT...WITH MODERATE OFFSHORE FLOW DEVELOPING
IN ITS WAKE LATE TUESDAY NIGHT AND WEDNESDAY.
DECISION SUPPORT...
DSS CODE...YELLOW.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...SLURRY SUPPORT
MONITORING RIVER FLOODING
DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED
WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED = FULL ENGAGEMENT FOR MODERATE TO HIGH RISK SVR
AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL
SIGNIFICANCE
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 83 66 85 70 / 20 10 30 10
BTR 85 70 87 72 / 20 10 30 10
ASD 82 69 83 71 / 20 10 40 10
MSY 83 70 84 72 / 20 10 30 10
GPT 80 72 83 71 / 30 20 30 10
PQL 80 69 84 71 / 30 20 40 10
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
1011 AM CDT SAT MAY 10 2014
.SOUNDING DISCUSSION...
PW VALUES HAVE DROPPED FROM 2.17" AT 00Z(1900CST YESTERDAY) TO
1.68" AT 12Z THIS MORNING. THIS IS EVIDENT FROM THE DRY LAYER THAT
HAS DEVELOPED BETWEEN THE SFC UP TO 850MB. YESTERDAYS SOUNDING
SHOWED A VERY SHALLOW COOL POOL THAT WAS RESPONSIBLE FOR GIVING
THE MUCH NEEDED INITIAL LIFT TO THE SFC PARCELS. ONCE PARCELS
REACHED ~975MB OR ~1100 FEET...THE PARCEL BECAME MOIST ADIABATIC
ALL THE WAY UP TO 300MB AND AT 14.5 G/KG MIXING RATIO(YES 14.5)...THESE
VARIABLES POINT TO A VERY TROPICAL AIR MASS WHICH MAY HAVE CAME
FROM THE DEEP MOISTURE LOADING FROM THE OLD TROPICAL SYSTEM OFF
THE WEST COAST OF MEXICO. THIS MORNINGS SOUNDING DOES NOT SHOW
THAT DEPTH OF MOISTURE ANY LONGER.
&&
.PREV DISCUSSION... /ISSUED 856 AM CDT SAT MAY 10 2014/
UPDATE...
SENDING UPDATED ZONES TO REMOVE HEADLINES AT TOP OF THE HOUR. FLASH FLOOD
WATCH ALLOWED TO EXPRIRE AT 9 AM AS SCHEDULED. 24/RR
&&
PREV DISCUSSION... /ISSUED 342 AM CDT SAT MAY 10 2014/
SYNOPSIS...
SURFACE LOW CENTERED OVER EASTERN ONTARIO WITH A COLD FRONT
EXTENDING SOUTHWARD AND SOUTHWESTWARD THROUGH THE OHIO VALLEY AND
INTO SOUTH CENTRAL MISSOURI WHERE IT HAS BECOME STATIONARY. LARGE
SHIELD OF LIGHT TO MODERATE RAINFALL OVER NORTHERN GULF COAST
REGION IS GRADUALLY ERODING AS OUTFLOW BOUNDARY FROM EARLIER
CONVECTION HELPS CUT OFF MOISTURE SOURCE. TEMPS SITTING IN THE
MID TO UPPER 60S WITH DEWPOINTS IN THE LOW TO MID 60S.
DISCUSSION...
HAVE CHOSEN TO LEAVE THE FLASH FLOOD WATCH IN PLACE JUST IN CASE
OF ANY UNEXPECTED REDEVELOPMENT OF HEAVIER STORMS DURING THE NEXT
FEW HOURS. THE GROUND IS NOW SATURATED ACROSS MOST OF THE AREA AND
RAINFALL RATES IN EXCESS OF 2 INCHES PER HOUR HAVE BEEN COMMON
WITH THIS AIR MASS. ANY HEAVIER STORMS THAT REDEVELOP WILL EASILY
PRODUCE SIMILAR RAINFALL RATES AND OVERWHELM NATURAL DRAINAGE.
ASSUMING MOTHER NATURE COOPERATES...THE FLASH FLOOD THREAT SHOULD
CONTINUE DIMINISHING THROUGH THE MORNING AND AN EXTENSION TO THE
FLASH FLOOD WATCH IS NOT CURRENTLY ANTICIPATED.
CONFIDENCE IN SHORT TERM FORECAST IS LOWER THAN NORMAL WITH FAIRLY
SIGNIFICANT DIFFERENCES IN THE MODELS CONCERNING RAINFALL. EURO IS
GENERALLY THE WETTEST OF THE MODELS WITH THE NAM BEING THE DRIEST
AND THE GFS SOMEWHERE IN THE MIDDLE...THOUGH EVEN GFS ENSEMBLE
MEMBERS GENERALLY INDICATE A 30 PERCENT SPREAD IN POP FORECASTS AT
ANY GIVEN LOCATION FOR TODAY. GIVEN RECENT RADAR TRENDS...AM
LEANING TOWARD THE LOWER POP SOLUTIONS FOR TODAY. THIS IS ALSO
SUPPORTED BY THE LATEST HRRR RUNS WHICH HAVE BEEN FAIRLY ACCURATE
AND CONSISTENT OVER THE PAST 8 RUNS. AM NOT QUITE AS AGGRESSIVE
CLEARING THE AREA OUT AS THE HRRR WHICH CUTS OFF NEARLY ALL
RAINFALL BY 15Z WITH LITTLE REDEVELOPMENT INDICATED DURING THE
EARLY AFTERNOON HOURS. THOUGH THERE MAY BE A SIGNIFICANT BREAK IN
THE RAIN...ESPECIALLY DURING THE LATE MORNING...BELIEVE THERE IS
ENOUGH MOISTURE IN PLACE TO SEE ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS DURING THE AFTERNOON HOURS SIMPLY DUE TO LIFT
ASSOCIATED WITH DAYTIME HEATING.
DEEP MOISTURE WILL REMAIN IN PLACE NEXT FEW DAYS AS PERSISTENT
ONSHORE FLOW CONTINUES TO PUMP IN WARM AND MOIST AIR FROM THE
GULF OF MEXICO. WITH WEAK AND BROAD RIDGING ALOFT AND A LACK OF
ANY LARGE SCALE FORCING MECHANISM...WILL BE RELYING ON DIURNAL
HEATING TO PROVIDE THE NECESSARY LIFT FOR CONVECTION. WITH TEMPS
FORECAST TO TOP OUT IN THE MID TO UPPER 80S EACH DAY...THAT SHOULD
BE ENOUGH TO FIRE OFF ISOLATED TO WIDELY SCATTERED SHOWERS AND
THUNDERSTORMS SO AM CARRYING SLIGHT CHANCE TO LOW END CHANCE POPS
EACH DAY THROUGH TUESDAY.
BY TUESDAY...STRONG UPPER TROUGH WILL BE DIGGING INTO THE SOUTHERN
PLAINS FORCING A COLD FRONT TOWARD THE AREA. MODELS CONTINUE TO
STRUGGLE WITH TIMING OF THIS FRONT AND THERE IS STILL ABOUT A 12
TO 18 HOUR DIFFERENCE IN THE TIMING OF THE LOCAL FROPA. THE GFS
CONTINUES TO BE THE MORE PROGRESSIVE OF THE MODELS WITH THE EURO
BEING THE SLOWER SOLUTION. HAVE GENERALLY GONE WITH A BLEND...
WHICH RESULTS IN A FROPA EARLY WEDNESDAY. GFS AND EURO BOTH AGREE
THAT WE SHOULD SEE SOME DECENT COOLING BEHIND THIS FRONT WITH
TEMPS DROPPING WELL BELOW NORMAL DURING THE OVERNIGHT HOURS
WEDNESDAY NIGHT AND THURSDAY NIGHT. HIGHS WILL ALSO DROP SEVERAL
DEGREES AND SHOULD TOP OUT IN THE UPPER 70S OR LOWER 80S WEDNESDAY
AND THURSDAY. THESE COOLER TEMPS WILL ALSO BE ACCOMPANIED BY LOWER
DEWPOINTS WHICH SHOULD MAKE THE AFTERNOONS DOWNRIGHT PLEASANT LATE
IN THE WEEK IF THE FORECAST PANS OUT.
AVIATION...
WIDESPREAD MAINLY LIGHT TO MODERATE RAIN CONTINUES FALL ACROSS MOST
OF THE FORECAST AREA EARLY THIS MORNING...AFFECTING ALL OF THE
TERMINALS. MVFR CONDITIONS WILL BE THE RULE THROUGH THE EARLY
MORNING HOURS WITH VFR CONDITIONS PREVAILING FROM MID MORNING ON AS
THE RAINFALL ACROSS THE AREA DIMINISHES.
MARINE...
A RIDGE OF HIGH PRESSURE EXTENDING ACROSS THE COASTAL WATERS WILL
PERSIST THROUGH THE WEEKEND BEFORE SHIFTING EAST EARLY NEXT WEEK. A
COLD FRONT WILL THEN PUSH ACROSS THE COASTAL WATERS TUESDAY NIGHT.
MODERATE ONSHORE FLOW WILL GENERALLY PREVAIL THROUGH THE PERIOD IN
ADVANCE OF THE COLD FRONT...WITH MODERATE OFFSHORE FLOW DEVELOPING
IN ITS WAKE LATE TUESDAY NIGHT AND WEDNESDAY.
DECISION SUPPORT...
DSS CODE...YELLOW.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...SLURRY SUPPORT
MONITORING RIVER FLOODING
DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED
WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED = FULL ENGAGEMENT FOR MODERATE TO HIGH RISK SVR
AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL
SIGNIFICANCE
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 83 66 85 70 / 20 10 30 10
BTR 85 70 87 72 / 20 10 30 10
ASD 82 69 83 71 / 40 20 40 10
MSY 83 70 84 72 / 40 20 30 10
GPT 80 72 83 71 / 50 20 30 10
PQL 80 69 84 71 / 50 30 40 10
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS NEW ORLEANS LA
856 AM CDT SAT MAY 10 2014
.UPDATE...
SENDING UPDATED ZONES TO REMOVE HEADLINES AT TOP OF THE HOUR. FLASH FLOOD
WATCH ALLOWED TO EXPRIRE AT 9 AM AS SCHEDULED. 24/RR
&&
.DECISION SUPPORT...
DSS CODE...BLUE.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...SLURRY SUPPORT
MONITORING RIVER FLOODING
DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED
WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED = FULL ENGAGEMENT FOR MODERATE TO HIGH RISK SVR
AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL
SIGNIFICANCE
&&
.PREV DISCUSSION... /ISSUED 342 AM CDT SAT MAY 10 2014/
SYNOPSIS...
SURFACE LOW CENTERED OVER EASTERN ONTARIO WITH A COLD FRONT
EXTENDING SOUTHWARD AND SOUTHWESTWARD THROUGH THE OHIO VALLEY AND
INTO SOUTH CENTRAL MISSOURI WHERE IT HAS BECOME STATIONARY. LARGE
SHIELD OF LIGHT TO MODERATE RAINFALL OVER NORTHERN GULF COAST
REGION IS GRADUALLY ERODING AS OUTFLOW BOUNDARY FROM EARLIER
CONVECTION HELPS CUT OFF MOISTURE SOURCE. TEMPS SITTING IN THE
MID TO UPPER 60S WITH DEWPOINTS IN THE LOW TO MID 60S.
DISCUSSION...
HAVE CHOSEN TO LEAVE THE FLASH FLOOD WATCH IN PLACE JUST IN CASE
OF ANY UNEXPECTED REDEVELOPMENT OF HEAVIER STORMS DURING THE NEXT
FEW HOURS. THE GROUND IS NOW SATURATED ACROSS MOST OF THE AREA AND
RAINFALL RATES IN EXCESS OF 2 INCHES PER HOUR HAVE BEEN COMMON
WITH THIS AIR MASS. ANY HEAVIER STORMS THAT REDEVELOP WILL EASILY
PRODUCE SIMILAR RAINFALL RATES AND OVERWHELM NATURAL DRAINAGE.
ASSUMING MOTHER NATURE COOPERATES...THE FLASH FLOOD THREAT SHOULD
CONTINUE DIMINISHING THROUGH THE MORNING AND AN EXTENSION TO THE
FLASH FLOOD WATCH IS NOT CURRENTLY ANTICIPATED.
CONFIDENCE IN SHORT TERM FORECAST IS LOWER THAN NORMAL WITH FAIRLY
SIGNIFICANT DIFFERENCES IN THE MODELS CONCERNING RAINFALL. EURO IS
GENERALLY THE WETTEST OF THE MODELS WITH THE NAM BEING THE DRIEST
AND THE GFS SOMEWHERE IN THE MIDDLE...THOUGH EVEN GFS ENSEMBLE
MEMBERS GENERALLY INDICATE A 30 PERCENT SPREAD IN POP FORECASTS AT
ANY GIVEN LOCATION FOR TODAY. GIVEN RECENT RADAR TRENDS...AM
LEANING TOWARD THE LOWER POP SOLUTIONS FOR TODAY. THIS IS ALSO
SUPPORTED BY THE LATEST HRRR RUNS WHICH HAVE BEEN FAIRLY ACCURATE
AND CONSISTENT OVER THE PAST 8 RUNS. AM NOT QUITE AS AGGRESSIVE
CLEARING THE AREA OUT AS THE HRRR WHICH CUTS OFF NEARLY ALL
RAINFALL BY 15Z WITH LITTLE REDEVELOPMENT INDICATED DURING THE
EARLY AFTERNOON HOURS. THOUGH THERE MAY BE A SIGNIFICANT BREAK IN
THE RAIN...ESPECIALLY DURING THE LATE MORNING...BELIEVE THERE IS
ENOUGH MOISTURE IN PLACE TO SEE ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS DURING THE AFTERNOON HOURS SIMPLY DUE TO LIFT
ASSOCIATED WITH DAYTIME HEATING.
DEEP MOISTURE WILL REMAIN IN PLACE NEXT FEW DAYS AS PERSISTENT
ONSHORE FLOW CONTINUES TO PUMP IN WARM AND MOIST AIR FROM THE
GULF OF MEXICO. WITH WEAK AND BROAD RIDGING ALOFT AND A LACK OF
ANY LARGE SCALE FORCING MECHANISM...WILL BE RELYING ON DIURNAL
HEATING TO PROVIDE THE NECESSARY LIFT FOR CONVECTION. WITH TEMPS
FORECAST TO TOP OUT IN THE MID TO UPPER 80S EACH DAY...THAT SHOULD
BE ENOUGH TO FIRE OFF ISOLATED TO WIDELY SCATTERED SHOWERS AND
THUNDERSTORMS SO AM CARRYING SLIGHT CHANCE TO LOW END CHANCE POPS
EACH DAY THROUGH TUESDAY.
BY TUESDAY...STRONG UPPER TROUGH WILL BE DIGGING INTO THE SOUTHERN
PLAINS FORCING A COLD FRONT TOWARD THE AREA. MODELS CONTINUE TO
STRUGGLE WITH TIMING OF THIS FRONT AND THERE IS STILL ABOUT A 12
TO 18 HOUR DIFFERENCE IN THE TIMING OF THE LOCAL FROPA. THE GFS
CONTINUES TO BE THE MORE PROGRESSIVE OF THE MODELS WITH THE EURO
BEING THE SLOWER SOLUTION. HAVE GENERALLY GONE WITH A BLEND...
WHICH RESULTS IN A FROPA EARLY WEDNESDAY. GFS AND EURO BOTH AGREE
THAT WE SHOULD SEE SOME DECENT COOLING BEHIND THIS FRONT WITH
TEMPS DROPPING WELL BELOW NORMAL DURING THE OVERNIGHT HOURS
WEDNESDAY NIGHT AND THURSDAY NIGHT. HIGHS WILL ALSO DROP SEVERAL
DEGREES AND SHOULD TOP OUT IN THE UPPER 70S OR LOWER 80S WEDNESDAY
AND THURSDAY. THESE COOLER TEMPS WILL ALSO BE ACCOMPANIED BY LOWER
DEWPOINTS WHICH SHOULD MAKE THE AFTERNOONS DOWNRIGHT PLEASANT LATE
IN THE WEEK IF THE FORECAST PANS OUT.
AVIATION...
WIDESPREAD MAINLY LIGHT TO MODERATE RAIN CONTINUES FALL ACROSS MOST
OF THE FORECAST AREA EARLY THIS MORNING...AFFECTING ALL OF THE
TERMINALS. MVFR CONDITIONS WILL BE THE RULE THROUGH THE EARLY
MORNING HOURS WITH VFR CONDITIONS PREVAILING FROM MID MORNING ON AS
THE RAINFALL ACROSS THE AREA DIMINISHES.
MARINE...
A RIDGE OF HIGH PRESSURE EXTENDING ACROSS THE COASTAL WATERS WILL
PERSIST THROUGH THE WEEKEND BEFORE SHIFTING EAST EARLY NEXT WEEK. A
COLD FRONT WILL THEN PUSH ACROSS THE COASTAL WATERS TUESDAY NIGHT.
MODERATE ONSHORE FLOW WILL GENERALLY PREVAIL THROUGH THE PERIOD IN
ADVANCE OF THE COLD FRONT...WITH MODERATE OFFSHORE FLOW DEVELOPING
IN ITS WAKE LATE TUESDAY NIGHT AND WEDNESDAY.
DECISION SUPPORT...
DSS CODE...YELLOW.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...SLURRY SUPPORT
MONITORING RIVER FLOODING
DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED
WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED = FULL ENGAGEMENT FOR MODERATE TO HIGH RISK SVR
AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL
SIGNIFICANCE
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 83 66 85 70 / 20 10 30 10
BTR 85 70 87 72 / 20 10 30 10
ASD 82 69 83 71 / 40 20 40 10
MSY 83 70 84 72 / 40 20 30 10
GPT 80 72 83 71 / 50 20 30 10
PQL 80 69 84 71 / 50 30 40 10
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.
&&
$$
24/RR
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
342 AM CDT SAT MAY 10 2014
.SYNOPSIS...
SURFACE LOW CENTERED OVER EASTERN ONTARIO WITH A COLD FRONT
EXTENDING SOUTHWARD AND SOUTHWESTWARD THROUGH THE OHIO VALLEY AND
INTO SOUTH CENTRAL MISSOURI WHERE IT HAS BECOME STATIONARY. LARGE
SHIELD OF LIGHT TO MODERATE RAINFALL OVER NORTHERN GULF COAST
REGION IS GRADUALLY ERODING AS OUTFLOW BOUNDARY FROM EARLIER
CONVECTION HELPS CUT OFF MOISTURE SOURCE. TEMPS SITTING IN THE
MID TO UPPER 60S WITH DEWPOINTS IN THE LOW TO MID 60S.
&&
.DISCUSSION...
HAVE CHOSEN TO LEAVE THE FLASH FLOOD WATCH IN PLACE JUST IN CASE
OF ANY UNEXPECTED REDEVELOPMENT OF HEAVIER STORMS DURING THE NEXT
FEW HOURS. THE GROUND IS NOW SATURATED ACROSS MOST OF THE AREA AND
RAINFALL RATES IN EXCESS OF 2 INCHES PER HOUR HAVE BEEN COMMON
WITH THIS AIR MASS. ANY HEAVIER STORMS THAT REDEVELOP WILL EASILY
PRODUCE SIMILAR RAINFALL RATES AND OVERWHELM NATURAL DRAINAGE.
ASSUMING MOTHER NATURE COOPERATES...THE FLASH FLOOD THREAT SHOULD
CONTINUE DIMINISHING THROUGH THE MORNING AND AN EXTENSION TO THE
FLASH FLOOD WATCH IS NOT CURRENTLY ANTICIPATED.
CONFIDENCE IN SHORT TERM FORECAST IS LOWER THAN NORMAL WITH FAIRLY
SIGNIFICANT DIFFERENCES IN THE MODELS CONCERNING RAINFALL. EURO IS
GENERALLY THE WETTEST OF THE MODELS WITH THE NAM BEING THE DRIEST
AND THE GFS SOMEWHERE IN THE MIDDLE...THOUGH EVEN GFS ENSEMBLE
MEMBERS GENERALLY INDICATE A 30 PERCENT SPREAD IN POP FORECASTS AT
ANY GIVEN LOCATION FOR TODAY. GIVEN RECENT RADAR TRENDS...AM
LEANING TOWARD THE LOWER POP SOLUTIONS FOR TODAY. THIS IS ALSO
SUPPORTED BY THE LATEST HRRR RUNS WHICH HAVE BEEN FAIRLY ACCURATE
AND CONSISTENT OVER THE PAST 8 RUNS. AM NOT QUITE AS AGGRESSIVE
CLEARING THE AREA OUT AS THE HRRR WHICH CUTS OFF NEARLY ALL
RAINFALL BY 15Z WITH LITTLE REDEVELOPMENT INDICATED DURING THE
EARLY AFTERNOON HOURS. THOUGH THERE MAY BE A SIGNIFICANT BREAK IN
THE RAIN...ESPECIALLY DURING THE LATE MORNING...BELIEVE THERE IS
ENOUGH MOISTURE IN PLACE TO SEE ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS DURING THE AFTERNOON HOURS SIMPLY DUE TO LIFT
ASSOCIATED WITH DAYTIME HEATING.
DEEP MOISTURE WILL REMAIN IN PLACE NEXT FEW DAYS AS PERSISTENT
ONSHORE FLOW CONTINUES TO PUMP IN WARM AND MOIST AIR FROM THE
GULF OF MEXICO. WITH WEAK AND BROAD RIDGING ALOFT AND A LACK OF
ANY LARGE SCALE FORCING MECHANISM...WILL BE RELYING ON DIURNAL
HEATING TO PROVIDE THE NECESSARY LIFT FOR CONVECTION. WITH TEMPS
FORECAST TO TOP OUT IN THE MID TO UPPER 80S EACH DAY...THAT SHOULD
BE ENOUGH TO FIRE OFF ISOLATED TO WIDELY SCATTERED SHOWERS AND
THUNDERSTORMS SO AM CARRYING SLIGHT CHANCE TO LOW END CHANCE POPS
EACH DAY THROUGH TUESDAY.
BY TUESDAY...STRONG UPPER TROUGH WILL BE DIGGING INTO THE SOUTHERN
PLAINS FORCING A COLD FRONT TOWARD THE AREA. MODELS CONTINUE TO
STRUGGLE WITH TIMING OF THIS FRONT AND THERE IS STILL ABOUT A 12
TO 18 HOUR DIFFERENCE IN THE TIMING OF THE LOCAL FROPA. THE GFS
CONTINUES TO BE THE MORE PROGRESSIVE OF THE MODELS WITH THE EURO
BEING THE SLOWER SOLUTION. HAVE GENERALLY GONE WITH A BLEND...
WHICH RESULTS IN A FROPA EARLY WEDNESDAY. GFS AND EURO BOTH AGREE
THAT WE SHOULD SEE SOME DECENT COOLING BEHIND THIS FRONT WITH
TEMPS DROPPING WELL BELOW NORMAL DURING THE OVERNIGHT HOURS
WEDNESDAY NIGHT AND THURSDAY NIGHT. HIGHS WILL ALSO DROP SEVERAL
DEGREES AND SHOULD TOP OUT IN THE UPPER 70S OR LOWER 80S WEDNESDAY
AND THURSDAY. THESE COOLER TEMPS WILL ALSO BE ACCOMPANIED BY LOWER
DEWPOINTS WHICH SHOULD MAKE THE AFTERNOONS DOWNRIGHT PLEASANT LATE
IN THE WEEK IF THE FORECAST PANS OUT.
&&
.AVIATION...
WIDESPREAD MAINLY LIGHT TO MODERATE RAIN CONTINUES FALL ACROSS MOST
OF THE FORECAST AREA EARLY THIS MORNING...AFFECTING ALL OF THE
TERMINALS. MVFR CONDITIONS WILL BE THE RULE THROUGH THE EARLY
MORNING HOURS WITH VFR CONDITIONS PREVAILING FROM MID MORNING ON AS
THE RAINFALL ACROSS THE AREA DIMINISHES.
&&
.MARINE...
A RIDGE OF HIGH PRESSURE EXTENDING ACROSS THE COASTAL WATERS WILL
PERSIST THROUGH THE WEEKEND BEFORE SHIFTING EAST EARLY NEXT WEEK. A
COLD FRONT WILL THEN PUSH ACROSS THE COASTAL WATERS TUESDAY NIGHT.
MODERATE ONSHORE FLOW WILL GENERALLY PREVAIL THROUGH THE PERIOD IN
ADVANCE OF THE COLD FRONT...WITH MODERATE OFFSHORE FLOW DEVELOPING
IN ITS WAKE LATE TUESDAY NIGHT AND WEDNESDAY.
&&
.DECISION SUPPORT...
DSS CODE...YELLOW.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...SLURRY SUPPORT
MONITORING RIVER FLOODING
DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED
WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED = FULL ENGAGEMENT FOR MODERATE TO HIGH RISK SVR
AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL
SIGNIFICANCE
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 83 66 85 70 / 40 10 30 10
BTR 85 70 87 72 / 40 10 30 10
ASD 82 69 83 71 / 60 20 40 10
MSY 83 70 84 72 / 60 20 30 10
GPT 80 72 83 71 / 70 20 30 10
PQL 80 69 84 71 / 70 30 40 10
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...FLASH FLOOD WATCH UNTIL 9 AM SATURDAY FOR THE FOLLOWING ZONES:
ASCENSION...ASSUMPTION...EAST BATON ROUGE...EAST
FELICIANA...IBERVILLE...LIVINGSTON...LOWER
JEFFERSON...LOWER LAFOURCHE...LOWER PLAQUEMINES...LOWER ST.
BERNARD...LOWER TERREBONNE...NORTHERN
TANGIPAHOA...ORLEANS...POINTE COUPEE...SOUTHERN
TANGIPAHOA...ST. CHARLES...ST. HELENA...ST. JAMES...ST.
JOHN THE BAPTIST...ST. TAMMANY...UPPER JEFFERSON...UPPER
LAFOURCHE...UPPER PLAQUEMINES...UPPER ST. BERNARD...UPPER
TERREBONNE...WASHINGTON...WEST BATON ROUGE...AND WEST
FELICIANA.
GM...NONE.
MS...FLASH FLOOD WATCH UNTIL 9 AM SATURDAY FOR THE FOLLOWING ZONES:
AMITE...HANCOCK...HARRISON...JACKSON...PEARL
RIVER...PIKE...WALTHALL...AND WILKINSON.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CARIBOU ME
650 PM EDT SAT MAY 10 2014
.SYNOPSIS...
A COLD FRONT WILL CROSS THE AREA TONIGHT. A BACKDOOR COLD FRONT
WILL MOVE IN FROM THE NORTHEAST SUNDAY NIGHT AND MONDAY WITH
COOLER TEMPERATURES AND A CHANCE OF SHOWERS. HIGH PRESSURE BUILDS
IN TUESDAY AND TUESDAY NIGHT BEFORE MOIST SOUTHERLY FLOW RETURNS
MID TO LATE WEEK.&&
.NEAR TERM /THROUGH SUNDAY/...
UPDATE: NOT MUCH HAPPENING ACROSS THE AREA AS SHOWERS/STORMS
HAVING A TUF TIME GETTING ORGANIZED. AN ISOLD SHOWER PAST HR MOVD
THRU PQI AND NOW INTO WRN NB W/ JUST SOME LGT TO BRIEFLY MDT RAIN
RPTD. HRRR SUGGESTS SOME SHOWERS/STORMS CURRENTLY NW OF THE AREA MAY
BUILD SWWRD AND MOVE ACROSS OUR NRN AREAS LATER THIS EVE. HAVE
ADJUSTED POPS/WX TO BETTER REFLECT CURRENT AND EXPECTED TRENDS...
PREV DISC: CLEARING OVER WESTERN MAINE AND THE QUEBEC EASTERN
TOWNSHIPS HAS ALLOWED FOR DESTABILIZING AHEAD OF THE SURFACE COLD
FRONT, WITH CONVECTION. EXPECT SCATTERED SHOWERS AND STORMS MAINLY
OVER NORTHERN AND CENTRAL PORTIONS OF THE AREA, WITH STRONG WINDS
BEING THE PRIMARY THREAT WITH THE STORMS. DO NOT EXPECT ANYTHING
SEVERE.
WEAK COLD FRONT PASSES THROUGH THIS EVENING AND DRIER AIR MOVES IN.
FOR SUNDAY, WITH WESTERLY FLOW OVER THE AREA, LOOK FOR A PARTLY
CLOUDY, BREEZY, AND WARM DAY DOWNEAST, BUT MOSTLY CLOUDY OVER THE
NORTH WITH A CHANCE OF SHOWERS AS A BACKDOOR COLD FRONT APPROACHES
FROM THE NORTHEAST. THIS COLD FRONT WILL MOVE INTO NORTHEASTERN
MAINE IN THE EVENING.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
CYCLONIC FLOW ALOFT WITH EMBEDDED SHORTWAVES WILL AFFECT OUR FCST
AREA THROUGH MOST OF THE SHORT TERM PERIOD. THIS WILL KEEP MUCH OF
THE AREA UNDER A CHANCE OF SHOWERS SUNDAY NIGHT THROUGH MONDAY.
FINALLY ON MONDAY NIGHT AND TUESDAY...CONDITIONS WILL BECOME
MOSTLY DRY BUT SEASONALLY COOL AS A RIDGE OF HIGH PRESSURE BUILDS
ACROSS THE NORTHEAST.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THE AFOREMENTIONED RIDGE WILL GRADUALLY DRIFT EWD THROUGH THE
EARLY PART OF THE EXTENDED FCST PERIOD. BY THE WED/TUES TIME
FRAME...MORE UNSETTLED CONDITIONS WILL DEVELOP ACROSS OUR WRN
ZONES IN RESPONSE TO RETURN SRLY FLOW AHEAD OF AN APPROACHING COLD
FRONT. THE MEDIUM RANGE MODEL THEN DIVERGE IN THEIR SOLUTIONS FOR
FRIDAY INTO SATURDAY OF NEXT WEEK...WITH THE GFS BEING MORE
AGGRESSIVE BRINGING LOW FROM THE SOUTHWEST ACROSS NEW ENGLAND WITH
WIDESPREAD PRECIP. THE ECMWF IS SLOWER WITH NO LOW DEVELOPING
ALONG THE MID-ATLANTIC. THE COLD FRONT IS EXPECTED MOVE OVER THE
CWA ON SATURDAY...BEFORE WASHING OUT.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
NEAR TERM:
LATE THIS AFTERNOON, EXPECT ANY REMAINING IFR TO DISSIPATE FROM WEST
TO EAST. GENERALLY VFR LATE AFTERNOON INTO OVERNIGHT HOURS, ALTHOUGH
SCATTERED STORMS LATE THIS AFTERNOON COULD LEAD TO LOCALLY GUSTY
WINDS AND BRIEF MVFR CONDITIONS.
MAINLY VFR ON SUNDAY, ALTHOUGH A FRONT MOVING INTO NORTHERN MAINE
LATE IN THE AFTERNOON COULD LEAD TO MVFR CEILINGS EITHER LATE
SUNDAY AFTERNOON OR SUNDAY NIGHT. WINDS WILL BE FAIRLY GUSTY OUT
OF THE WEST ON SUNDAY.
SHORT TERM:
MVFR CEILINGS POSSIBLE SUNDAY NIGHT INTO MONDAY, MAINLY NORTH OF
BANGOR. CLEARING WITH VFR FOR TUESDAY.
&&
.MARINE...
NEAR TERM:
SOUTH WINDS WILL DIMINISH TO BELOW SMALL CRAFT LEVELS THIS
EVENING, WITH SEAS FALLING BELOW SMALL CRAFT LEVELS (5 FEET)
AROUND DAYBREAK SUNDAY. WINDS SWITCH TO OFFSHORE FOR SUNDAY, AND
MAY PICK UP TO SMALL CRAFT CONDITIONS IN THE AFTERNOON.
SHORT TERM:
WINDS AND WAVES WILL INCREASE FOR THE SHORT TERM...POSSIBLY REACHING
MARGINAL SMALL CRAFT ADVISORY LEVELS.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT SUNDAY FOR ANZ050-051.
&&
$$
NEAR TERM...KHW/FOISY
SHORT TERM...RB
LONG TERM...RB
AVIATION...KHW
MARINE...KHW/FOISY/RB
AREA FORECAST DISCUSSION
NWS GRAY ME
254 PM EDT SAT MAY 10 2014
.SYNOPSIS...
A COLD FRONT WILL STALL BRIEFLY OFFSHORE TONIGHT. HIGH PRESSURE
WILL BUILD IN FOR SUNDAY AND MONDAY. A BACK DOOR COLD FRONT TRACKS
SOUTHWEST ACROSS THE AREA MONDAY NIGHT AND TUESDAY MORNING. HIGH
PRESSURE WILL THEN BUILD IN FROM THE NORTHEAST THROUGH WEDNESDAY.
A SLOW MOVING COLD FRONT WILL MOVE IN FROM THE WEST ON THURSDAY
AND CROSS THE AREA FRIDAY. HIGH PRESSURE WILL ENTER THE REGION
NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
CLOUDS AND FOG ARE HANGING IN TOUGH OVER EASTERN AREAS LATE THIS
AFTERNOON. OTHERWISE...CLEARING AND SOMEWHAT DRIER AIR CONTINUES
TO MOVE IN FROM THE WEST. THERE IS CONVECTION OVER SOUTHERN NYS
WHICH WILL CONTINUE TO MOVE ENE PER LATEST HRRR MODEL RUN.
CONVECTION MAY BRIEFLY REACH SOUTHERNMOST PORTIONS OF THE FORECAST
AREA THIS EVENING...AND HAVE INCLUDED CHC POPS FOR THIS REGION FOR
A COUPLE HOURS.
OTHERWISE...THERE APPEARS TO BE SUFFICIENT GRADIENT OVERNIGHT TO
KEEP FOG FROM FORMING.
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
OFFSHORE FLOW WILL ALLOW FOR WARM TEMPERATURES ON SUNDAY FOR ALL
AREAS. THIS WILL BRING TEMPERATURES IN THE 70S FOR MANY
SECTIONS...THE FIRST TIME IN QUITE A PERIOD. CYCLONIC FLOW MAY
INDUCE A COUPLE SHOWERS OVER THE FAR NRN MOUNTAINS DURING THE
LATE MORNING AND EARLY AFTERNOON HOURS.
IT WILL BE DRY SUNDAY NIGHT. HOWEVER...A BACK DOOR COLD FRONT MAY
BE APPROACHING THE REGION...RETROGRADING INTO OUR AREA FROM
NORTHEAST TO SOUTHWEST.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
MODELS ARE IN GOOD AGREEMENT THROUGH LATE NEXT WEEK ON LONGWAVE
PATTERN. THE UPPER TROUGH OVER NEW ENGLAND IS LIFTING OUT AS WE
BEGIN THE PERIOD ON MONDAY WITH UPPER RIDGE PROGRESSING EASTWARD
INTO THE REGION THROUGH MIDWEEK BEFORE SLIDING OFFSHORE BY
THURSDAY. AN UNUSUALLY DEEP TROUGH FOR THIS TIME OF YEAR THEN
ARRIVES BY LATE IN THE WEEK BEFORE CLOSING OFF OVER THE GREAT
LAKES. OVERALL...EXPECT ONE WELL ABOVE NORMAL DAY MONDAY FOLLOWED
BY SEVERAL DAYS OF WELL BELOW NORMAL TEMPERATURES AS FLOW TURNS
ONSHORE. IN THE DAILIES...WE BEGIN THE PERIOD WITH A FRONT STALLED
TO OUR SOUTH AND WEST AS HIGH PRESSURE BUILDS BY TO OUR
NORTH...BEFORE THE HIGH SLIDES OFFSHORE ON WEDNESDAY. A WARM
WESTERLY FLOW ON MONDAY IS REPLACED BY A COOL ONSHORE FLOW FOR
TUESDAY AND WEDNESDAY. WHILE THE RIDGE WILL KEEP THE FRONT STALLED
TO OUR WEST THROUGH WEDNESDAY...THE PERSISTENT ONSHORE FLOW MAY
EVENTUALLY PRODUCE MARINE STRATUS AND DRIZZLE BY TUESDAY NIGHT OR
WEDNESDAY. WE BECOME INCREASINGLY UNSETTLED AFTER THAT AS THE
FRONTAL BOUNDARY MEANDERS EASTWARD AND THE UPPER TROUGH CLOSES OFF
TO OUR WEST.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
SHORT TERM...LOCAL LIFR CONDITIONS EARLY EAST...OTHERWISE
IMPROVING TO VFR.
LONG TERM...
WED - THU...AREAS OF MVFR IN MARINE STRATUS WITH LCL IFR POSSIBLE
IN FOG AND DRIZZLE.
&&
.MARINE...
SHORT TERM...SCA TO REMAIN IN EFFECT FOR SEAS.
LONG TERM...
TUE - THU...SMALL CRAFT WINDS AND SEAS ARE POSSIBLE.
&&
.FIRE WEATHER...
SHOWERS TODAY HAVE LEFT HUMIDITY LEVELS HIGH AND FIRE CONCERNS LOW.
HOWEVER...DRIER CONDITIONS RETURN ON SUNDAY. WITH DEEP MIXING THE
HUMIDITY LEVELS WILL FALL TO 25 TO 30 PERCENT ON THE COASTAL SIDE
OF THE MOUNTAINS DURING THE AFTERNOON SUNDAY ALONG WITH WINDS
GUSTING TO 20 MPH. THIS BORDERLINES BUT DOES NOT EXCEED RED FLAG
WARNING CONDITIONS. SOME WETTING TODAY HAS HELPED FUEL
CONDITIONS WILL BE COORDINATING WITH MAINE LATER TODAY.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT SUNDAY FOR ANZ150-152.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ154.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAY ME
952 AM EDT SAT MAY 10 2014
.SYNOPSIS...
A COLD FRONT WILL CROSS THE AREA THIS AFTERNOON...WHICH WILL STALL
BRIEFLY OFFSHORE TONIGHT. HIGH PRESSURE WILL BUILD IN FOR SUNDAY
AND MONDAY. A BACK DOOR COLD FRONT TRACKS SOUTHWEST ACROSS THE
AREA MONDAY NIGHT AND TUESDAY MORNING. HIGH PRESSURE WILL THEN
BUILD IN FROM THE NORTHEAST THROUGH WEDNESDAY. A SLOW MOVING COLD
FRONT WILL MOVE IN FROM THE WEST ON THURSDAY AND CROSS THE AREA
FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
1347Z UPDATE...HAVE UPDATED GRIDS BASED ON CURRENT CONDITIONS. LOW
CLOUDS...FOG AND SHOWERS CONTINUE ACROSS PORTIONS OF THE FORECAST
AREA. THERE ARE ALSO A FEW LIGHTNING STROKES ALONG THE COAST AND
THE OFFSHORE WATERS WHICH WILL LAST FOR ANOTHER HOUR OR TWO.
LATEST HRRR RUN CONTINUES TO SHOW THIS PRECIPITATION EXITING
EASTERN PORTIONS OF THE FORECAST AREA BY AROUND 18Z. CLEARING TO
TAKE PLACE THIS AFTERNOON...HOWEVER THE PRECISE TIME OF
THIS...ESPECIALLY ALONG THE COAST WILL BE CHALLENGING. LATEST STLT
IMAGERY CONTINUES TO SHOW A SHARP CLEARING LINE OVER VERMONT AND
EASTERNMOST NYS. COASTAL LOW CLOUDS WILL HANG ON TOUGH THROUGH
EARLY THIS AFTERNOON HOWEVER...ESPECIALLY AS YOU HEAD EAST TOWARDS
PENOBSCOT BAY.
PREV DISC...
RAIN HAS MOVED INTO NORTHERN/CENTRAL NEW HAMPSHIRE
AND NORTHWEST MAINE. THIS SHOULD CONTINUE FOR ABOUT 3 HOURS BEFORE
ENDING FROM WEST TO EAST. THE BACK EDGE OF THIS PRECIPITATION IS
ALREADY VISIBLE ON REGIONAL RADAR IMAGERY IN NEW YORK STATE...
WITH A TRACK SET TO ARRIVE IN NEW HAMPSHIRE AT ABOUT 10AM. HAVE
ADJUSTED POP FORECAST TO BETTER REFLECT CERTAINTY OF PRECIPITATION
ACROSS MUCH OF NORTHERN AREAS AS WELL AS TIMING OF ARRIVAL AND
DEPARTURE OF THE AREA OF RAIN. NO OTHER CHANGES WERE MADE TO THE
FORECAST.
ORIGINAL DISCUSSION...
AS THE RIDGE GRADUALLY SHIFTS EAST THIS MORNING... IT WILL BE
REPLACED BY A SHORTWAVE TROUGH MOVING OUT OF THE GREAT LAKES. THIS
TROUGH IS ALREADY PRODUCING WIDESPREAD SHOWERS ACROSS UPSTATE NEW
YORK. THIS SHOWER ACTIVITY WILL SPREAD ACROSS NEW HAMPSHIRE AND
MAINE DURING THE MORNING HOURS AHEAD OF THE FRONT. AN ISOLATED
THUNDERSTORM IS POSSIBLE AS WELL. EXPECT SHOWERS TO END FROM WEST
TO EAST DURING THE MORNING TO EARLY AFTERNOON. WINDS BEHIND THE
FRONT SHIFT TO THE WEST AND CLOUDS WILL CLEAR OUT. TEMPERATURES
WILL WARM INTO THE 70S... THOUGH NEAR THE COAST FROM PORTLAND
EASTWARD MAY STAY IN THE 60S. PARTS OF SOUTHERN AND CENTRAL NEW
HAMPSHIRE COULD GET CLOSE TO 80 DEGREES.
IF PORTLAND REACHES 70 DEGREES IT WILL BE THE FIRST TIME THIS
YEAR. THAT IS ABOUT 3 WEEKS LATER THAN NORMAL FOR THE FIRST 70
DEGREE DAY.
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
ANOTHER SHORTWAVE TROUGH WILL TRACK THROUGH THE MID ATLANTIC AND
SOUTHERN NEW ENGLAND TONIGHT. THIS IS EXPECTED TO PRODUCE SHOWERS
OVERNIGHT. SOUTHERN NEW HAMPSHIRE AND COASTAL MAINE MAY BE BRUSHED
BY A FEW SHOWERS OVERNIGHT FROM THIS FEATURE BUT MOST OF THE AREA
WILL REMAIN DRY. TEMPERATURES BOTTOM OUT IN THE 40S AND 50S.
SHOULD BE ANOTHER MOSTLY SUNNY AND WARM DAY ON SUNDAY. WARM/DRY
AIR ALOFT WILL ALLOW FOR GOOD MIXING WITH WINDS GUSTING AS HIGH AS
25 MPH. THIS SHOULD BE ENOUGH TO PREVENT THE SEA BREEZE FROM
REACHING THE COAST... AND THUS EVEN COASTAL AREAS SHOULD SEE 70+
DEGREES ON SUNDAY.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
SURFACE RIDGE LOOKS TO HOLD SUNDAY NIGHT INTO AT LEAST PART OF THE
DAY ON MONDAY...WHICH WILL MAKE FOR ANOTHER WARM AND GENERALLY
FAIR DAY...ALTHOUGH WILL HAVE TO WATCH FOR INCREASED CLOUDS OR
SHOWERS IN NE ZONES IN THE AFTERNOON AS WEAK WAVE AT 500 MB...AND
BACK DOOR SURFACE COLD FRONT APPROACHES. IN AND OF ITSELF THIS BACK
DOOR COLD FRONT IS NOT THAT IMPRESSIVE...BUT MODELS WANT TO BRING
A REMNANT MCS-LIKE SYSTEM OVER THE TOP OF THE RIDGE ASSOCIATED WITH
MID LEVEL JET MAX. THIS COMBINATION INCREASES THE CHANCES OF
SHOWERS ACROSS THE FORECAST AREA MONDAY NIGHT INTO EARLY TUESDAY.
ONCE THE SYSTEMS CLEAR OUT OF THE AREA TUESDAY...COOLER SURFACE
HIGH BUILDS SOUTHWARD...AND WE WILL SEE SOME CLEARING WITH HIGHS
THE 60S TUESDAY INTO WEDNESDAY. 500MB PATTERN BECOMES QUITE
AMPLIFIED BY WEDNESDAY...AS 500MB CLOSED LOW DEVELOPS TO THE
WEST...AND RIDGE AMPLIFIES TO THE EAST. THIS WILL PRODUCE A SLOW
MOVING COLD FRONT TO OUR WEST WHICH WILL TRACK SLOWLY TO THE EAST
THURSDAY-FRIDAY AND WILL BRING A THREAT OF SHOWERS...ALTHOUGH MODELS
CONTINUE TO PROLONG THE ARRIVAL OF THE FRONT...WHICH LOOKS TO BE
LATE FRIDAY OR SATURDAY AT THIS POINT...WHICH WOULD BE THE BEST
SHOT FOR RAIN.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM...
IFR CEILINGS AND SHOWERS CONTINUE THROUGH THE MORNING. WINDS SHIFT
TO THE WEST BEHIND A FRONT LATE IN THE MORNING OR EARLY AFTERNOON.
THIS SHOULD BE ENOUGH TO CLEAR OUT THE LOW CLOUDS AND BRING
CONDITIONS BACK TO VFR. VFR CONTINUES ON SUNDAY WITH GUSTY
NORTHWEST WINDS.
LONG TERM...
MAINLY VFR SUNDAY NIGHT THRU WEDNESDAY. SOME POSSIBLE FLIGHT
RESTRICTIONS MONDAY NIGHT IN SHOWERS.
&&
.MARINE...
SHORT TERM...
SMALL CRAFT ADVISORY FOR PENOBSCOT BAY WAS DROPPED AS WAVE HEIGHTS
ARE NOT EXPECTED TO REACH 5 FEET INSIDE THE ISLANDS. THE SOUTHERLY
FLOW TODAY WILL PROVIDE A LONG ENOUGH FETCH TO PRODUCE WAVE
HEIGHTS OF 5 TO 7 FEET OVER THE OUTER WATERS... ESPECIALLY IN THE
EASTERN WATERS. WINDS SHIFT TO THE WEST THIS EVENING BEHIND THE
FRONT. WAVE HEIGHTS SHOULD FALL BELOW 5 FEET AGAIN OVERNIGHT.
LONG TERM...SCA CONDITIONS NOT EXPECTED SUNDAY NIGHT THRU WEDNESDAY.
&&
.FIRE WEATHER...
SHOWERS TODAY WILL KEEP HUMIDITY LEVELS HIGH AND FIRE CONCERNS
LOW. HOWEVER... DRIER CONDITIONS RETURN ON SUNDAY. WITH DEEP
MIXING THE HUMIDITY LEVELS WILL FALL TO 20 TO 30 PERCENT ON THE
COASTAL SIDE OF THE MOUNTAINS DURING THE AFTERNOON SUNDAY ALONG
WITH WINDS GUSTING TO 25 MPH. THIS COULD WARRANT A RED FLAG
WARNING DEPENDING ON FUEL CONDITIONS.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT SUNDAY FOR ANZ150-152.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ154.
&&
$$
AREA FORECAST DISCUSSION
NWS CARIBOU ME
612 AM EDT SAT MAY 10 2014
.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION LATER TODAY INTO TONIGHT.
AN UPPER LEVEL DISTURBANCE IS EXPECTED TO SLIDE ACROSS THE REGION ON
SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
615 AM UPDATE...MINOR ADJUSTMENTS TO HRLY TEMPS...OTHERWISE
PREVIOUS FORECAST REMAINS ON TRACK.
PREVIOUS DISCUSSION...THE UPPER RIDGE SHIFT EAST OF THE AREA AS
THE COLD FRONT MOVES ACROSS NH. PARTIAL CLEARING THIS MORNING INTO
THE EARLY AFTERNOON IN THE WARM SECTOR COULD ALLOW FOR SOME
THUNDERSTORM ACTIVITY ACROSS INTERIOR DOWNEAST AND THE INTERIOR
HIGH LANDS TOMORROW AFTERNOON IN ADVANCE OF THE APPROACHING COLD
FRONT. THE COLD FRONT WILL MOVE THROUGH LATE AFTERNOON EARLY IN
THE EVENING. HIGHER PRESSURE WILL BUILD IN BEHIND THE COLD FRONT
AND WILL DOMINATE THROUGH THE END OF THE PERIOD.
LOADED HRRR FOR SKY/POP GRIDS THROUGH 12Z USED A BLEND OF
NAM/GEM/GFS/ECMWF FOR BALANCE OF PERIOD. LOADED NAM/GEM/GFS/ECMWF
FOR HRLY TEMP/DP/WNDS. HPC GUIDANCE FOR QPF. ADDED 15 PERCENT TO
WNDS FOR GUSTS OVER LAND...20 PERCENT OVER WATER. LOADED NAWAVE 4
FOR SEAS IN THE COASTAL WATERS.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
UNSETTLED CONDITIONS IN MONDAY WITH A BLOCKING PATTERN IN PLACE.
A SFC TROF IS FORECAST TO SWING ACROSS THE REGION ON SUNDAY. BEST
UPPER LEVEL SUPPORT IS SLATED TO BE ACROSS THE FAR N AND W.
DECIDED TO FOLLOW THE DAYCREW`S SETUP AND CONTINUE W/A CHANCE FOR
SHOWERS(30-40%) INTO SUNDAY NIGHT. THE AXIS OF SHOWER ACTIVITY
DOES SHIFT TO THE N AND E AND THIS IS SUPPORTED BY THE ECMWF/GFS
AND SREF. FURTHER S ACROSS THE CENTRAL HIGHLANDS AND INTO THE
DOWNEAST, PRETTY MUCH RAIN-FREE SUNDAY INTO SUNDAY NIGHT W/THE
POTENTIAL FOR PARTIAL CLEARING. DAYTIME HIGH TEMPERATURES ON
SUNDAY WILL BE DEPENDENT ON SUNSHINE AND THEREFORE, DECIDED TO GO
W/MID TO UPPER 60S ACROSS THE CENTRAL AND DOWENAST AREAS AND
SLIGHTLY COOLER ACROSS THE NORTHERN 1/2 OF THE CWA W/UPPER 50S TO
AROUND 60.
THE BIGGER CHALLENGE WILL BE MONDAY AS THE MEDIUM RANGE GUIDANCE
IS SHOWING DISCONTINUITY W/THE BLOCKING PATTERN. THE ECMWF
CONTINUES TO HOLD ITS COURSE OF BRINGING ANOTHER DISTURBANCE
THROUGH THE REGION WHILE THE GFS WANT TO DRY IT OUT W/HIGH PRES
NOSING DOWN FROM CANADA. THE GFS ENSEMBLE KEEPS THE FRONT
LINGERING ACROSS NORTHERN AND SECTIONS. STAYED CLOSER TO AN
ENSEMBLE APPROACH BLENDING IN THE ECMWF AND KEPT A CHANCE FOR SHOWERS
IN THE AFOREMENTIONED AREAS FOR MONDAY INTO MONDAY EVENING.
TEMPERATURES ON MONDAY ARE EXPECTED TO MID TO UPPER 50S ACROSS THE
NORTH AND WEST AND LOW TO MID 60S CENTRAL AND DOWNEAST. QPF FOR
THIS TERM IS FORECAST TO BE LESS THAN 0.15".
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
THE UNSETTLED PATTERN CONTINUES THROUGH THIS TERM.
DRY WEATHER LOOKS TO RETURN FOR TUESDAY INTO MIDDAY WEDNESDAY AS HIGH
PRES BUILDS DOWN FROM CANADA. COOLER FOR TUESDAY W/AOB NORMAL TEMPERATURES
AND THEN TEMPERATURES ARE EXPECTED TO RISE INTO LOWER 60S BY WEDNESDAY.
HIGH PRES IS FORECAST TO SLIDE OFF THE E BY THURSDAY W/A CHANCE
FOR SHOWERS AS A FRONTAL BOUNDARY SLOWLY APPROACHES FROM THE WEST.
DECIDED TO CONTINUE THE DAYCREW`S TREND AND CARRY THE CHANCE FOR
SHOWERS INTO FRIDAY. THE UPSIDE TO THIS IS THAT TEMPERATURES ARE
FORECAST TO BE IN THE 60S BOTH THURSDAY AND FRIDAY.
&&
.AVIATION /10Z SATURDAY THROUGH WEDNESDAY/...
NEAR TERM: IFR CONDITIONS ALL SITES EARLY THIS MORNING WITH SCT
SHOWERS AND ISOLATED TSTMS. SKYCON WILL BREAK LATE MORNING BECMG
MVFR INTO MID AFTERNOON AHEAD OF THE APPROACHING COLD FRONT. SCT
SHOWERS AND TSTMS WILL RETURN MID TO LATE AFTERNOON THROUGH EARLY
EVENING WITH THE PASSING OF THE COLD FRONT. IMPROVING CONDITIONS
OVERNIGHT AS HIGH PRESSURE BUILDS IN BEHIND THE COLD FRONT.
SHORT TERM: MVFR POSSIBLE FOR THE NORTHERN TERMINALS ON SUNDAY
MAINLY N OF KHUL. MVFR CONDITIONS AGAIN ON MONDAY ALL THE WAY TO
KHUL AND VFR FOR KBGR AND KBHB. MVFR CIGS COULD POSE A PROBLEM FOR
KBGR AND KBHB MONDAY NIGHT AND TUESDAY AS A ENE FLOW SETS UP.
&&
.MARINE...
NEAR TERM: AN SCA IS IN EFFECT FOR THE OUTER WATERS FOR WINDS AND SEAS.
WINDS AND SEAS WILL FALL BELOW SCA CRITERIA LATE IN THE PERIOD.
SHORT TERM: NO HEADLINES EXPECTED FOR THIS TERM. WINDS 10-15 KTS
W/GUST TO 20 KTS ON SUNDAY DROPPING OFF TO 10 KTS OR LESS SUNDAY
NIGHT THROUGH MONDAY. WINDS ARE EXPECTED TO PICK UP TO 10-15 KTS
W/GUSTS NEAR 20 KTS MONDAY NIGHT INTO TUESDAY AS HIGH PRES BUILDS
DOWN FROM CANADA AND THE FLOW BECOME ENE. WAVE HEIGHTS WILL RANGE
FROM 2-4 FT MAINLY AWAY FROM THE INTRA COASTAL AREAS.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT SUNDAY FOR ANZ050-051.
&&
$$
NEAR TERM...NORTON
SHORT TERM...HEWITT
LONG TERM...HEWITT
AVIATION...NORTON/HEWITT
MARINE...NORTON/HEWITT
AREA FORECAST DISCUSSION
NWS CARIBOU ME
456 AM EDT SAT MAY 10 2014
.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION LATER TODAY INTO TONIGHT.
AN UPPER LEVEL DISTURBANCE IS EXPECTED TO SLIDE ACROSS THE REGION ON
SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AT THE START OF THE NEAR TERM PERIOD THE WARM FRONT MOVES INTO
NRN MAINE. THE UPPER RIDGE SHIFT EAST OF THE AREA AS THE COLD
FRONT MOVES ACROSS NH. PARTIAL CLEARING TOMORROW MORNING INTO THE
EARLY AFTERNOON IN THE WARM SECTOR COULD ALLOW FOR SOME
THUNDERSTORM ACTIVITY ACROSS INTERIOR DOWNEAST AND THE INTERIOR
HIGH LANDS TOMORROW AFTERNOON IN ADVANCE OF THE APPROACHING COLD
FRONT. THE COLD FRONT WILL MOVE THROUGH LATE AFTERNOON EARLY IN
THE EVENING. HIGHER PRESSURE WILL BUILD IN BEHIND THE COLD FRONT
AND WILL DOMINATE THROUGH THE END OF THE PERIOD.
LOADED HRRR FOR SKY/POP GRIDS THROUGH 12Z USED A BLEND OF
NAM/GEM/GFS/ECMWF FOR BALANCE OF PERIOD. LOADED NAM/GEM/GFS/ECMWF
FOR HRLY TEMP/DP/WNDS. HPC GUIDANCE FOR QPF. ADDED 15 PERCENT TO
WNDS FOR GUSTS OVER LAND...20 PERCENT OVER WATER. LOADED NAWAVE 4
FOR SEAS IN THE COASTAL WATERS.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
UNSETTLED CONDITIONS IN MONDAY WITH A BLOCKING PATTERN IN PLACE.
A SFC TROF IS FORECAST TO SWING ACROSS THE REGION ON SUNDAY. BEST
UPPER LEVEL SUPPORT IS SLATED TO BE ACROSS THE FAR N AND W.
DECIDED TO FOLLOW THE DAYCREW`S SETUP AND CONTINUE W/A CHANCE FOR
SHOWERS(30-40%) INTO SUNDAY NIGHT. THE AXIS OF SHOWER ACTIVITY
DOES SHIFT TO THE N AND E AND THIS IS SUPPORTED BY THE ECMWF/GFS
AND SREF. FURTHER S ACROSS THE CENTRAL HIGHLANDS AND INTO THE
DOWNEAST, PRETTY MUCH RAIN-FREE SUNDAY INTO SUNDAY NIGHT W/THE
POTENTIAL FOR PARTIAL CLEARING. DAYTIME HIGH TEMPERATURES ON
SUNDAY WILL BE DEPENDENT ON SUNSHINE AND THEREFORE, DECIDED TO GO
W/MID TO UPPER 60S ACROSS THE CENTRAL AND DOWENAST AREAS AND
SLIGHTLY COOLER ACROSS THE NORTHERN 1/2 OF THE CWA W/UPPER 50S TO
AROUND 60.
THE BIGGER CHALLENGE WILL BE MONDAY AS THE MEDIUM RANGE GUIDANCE
IS SHOWING DISCONTINUITY W/THE BLOCKING PATTERN. THE ECMWF
CONTINUES TO HOLD ITS COURSE OF BRINGING ANOTHER DISTURBANCE
THROUGH THE REGION WHILE THE GFS WANT TO DRY IT OUT W/HIGH PRES
NOSING DOWN FROM CANADA. THE GFS ENSEMBLE KEEPS THE FRONT
LINGERING ACROSS NORTHERN AND SECTIONS. STAYED CLOSER TO AN
ENSEMBLE APPROACH BLENDING IN THE ECMWF AND KEPT A CHANCE FOR SHOWERS
IN THE AFOREMENTIONED AREAS FOR MONDAY INTO MONDAY EVENING.
TEMPERATURES ON MONDAY ARE EXPECTED TO MID TO UPPER 50S ACROSS THE
NORTH AND WEST AND LOW TO MID 60S CENTRAL AND DOWNEAST. QPF FOR
THIS TERM IS FORECAST TO BE LESS THAN 0.15".
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
THE UNSETTLED PATTERN CONTINUES THROUGH THIS TERM.
DRY WEATHER LOOKS TO RETURN FOR TUESDAY INTO MIDDAY WEDNESDAY AS HIGH
PRES BUILDS DOWN FROM CANADA. COOLER FOR TUESDAY W/AOB NORMAL TEMPERATURES
AND THEN TEMPERATURES ARE EXPECTED TO RISE INTO LOWER 60S BY WEDNESDAY.
HIGH PRES IS FORECAST TO SLIDE OFF THE E BY THURSDAY W/A CHANCE
FOR SHOWERS AS A FRONTAL BOUNDARY SLOWLY APPROACHES FROM THE WEST.
DECIDED TO CONTINUE THE DAYCREW`S TREND AND CARRY THE CHANCE FOR
SHOWERS INTO FRIDAY. THE UPSIDE TO THIS IS THAT TEMPERATURES ARE
FORECAST TO BE IN THE 60S BOTH THURSDAY AND FRIDAY.
&&
.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
NEAR TERM: IFR CONDITIONS ALL SITES EARLY THIS MORNING WITH SCT
SHOWERS AND ISOLATED TSTMS. SKYCON WILL BREAK LATE MORNING BECMG
MVFR INTO MID AFTERNOON AHEAD OF THE APPROACHING COLD FRONT. SCT
SHOWERS AND TSTMS WILL RETURN MID TO LATE AFTERNOON THROUGH EARLY
EVENING WITH THE PASSING OF THE COLD FRONT. IMPROVING CONDITIONS
OVERNIGHT AS HIGH PRESSURE BUILDS IN BEHIND THE COLD FRONT.
SHORT TERM: MVFR POSSIBLE FOR THE NORTHERN TERMINALS ON SUNDAY
MAINLY N OF KHUL. MVFR CONDITIONS AGAIN ON MONDAY ALL THE WAY TO
KHUL AND VFR FOR KBGR AND KBHB. MVFR CIGS COULD POSE A PROBLEM FOR
KBGR AND KBHB MONDAY NIGHT AND TUESDAY AS A ENE FLOW SETS UP.
&&
.MARINE...
NEAR TERM: AN SCA IS IN EFFECT FOR THE OUTER WATERS FOR WINDS AND SEAS.
WINDS AND SEAS WILL FALL BELOW SCA CRITERIA LATE IN THE PERIOD.
SHORT TERM: NO HEADLINES EXPECTED FOR THIS TERM. WINDS 10-15 KTS
W/GUST TO 20 KTS ON SUNDAY DROPPING OFF TO 10 KTS OR LESS SUNDAY
NIGHT THROUGH MONDAY. WINDS ARE EXPECTED TO PICK UP TO 10-15 KTS
W/GUSTS NEAR 20 KTS MONDAY NIGHT INTO TUESDAY AS HIGH PRES BUILDS
DOWN FROM CANADA AND THE FLOW BECOME ENE. WAVE HEIGHTS WILL RANGE
FROM 2-4 FT MAINLY AWAY FROM THE INTRA COASTAL AREAS.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM THIS MORNING TO 6 AM EDT SUNDAY
FOR ANZ050-051.
&&
$$
NEAR TERM...NORTON
SHORT TERM...HEWITT
LONG TERM...HEWITT
AVIATION...NORTON/HEWITT
MARINE...NORTON/HEWITT
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
904 PM EDT SUN MAY 11 2014
.SYNOPSIS...
ALTHOUGH WARM WEATHER WILL QUICKLY RETURN...THE CHANCE FOR RAIN
INCREASES AS THE WEEK PROGRESSES.
&&
.NEAR TERM /THROUGH MONDAY/...
CLUSTER OF STORMS OVER CENTRAL OHIO CONTINUES TO SLOWLY MOVE
EASTWARD THIS EVENING. MODERATE CAPE AND WEAK SHEAR HAS SUPPORTED A
FEW STORMS TO SEVERE LEVELS OVER OHIO BUT EXPECT THIS TREND TO
QUICKLY DIMINISH AS INSTABILITY WEAKENS. THE MESOANALYSIS
CONTINUES TO SHOW THAT MUCH OF OUR REGION IS CAPPED AND EARLIER
SATELLITE DATA SHOWED VERY LITTLE CU DEVELOPMENT OVER OUR REGION
WHICH REINFORCES THIS. HAVE UPPED THE POPS OVER OHIO BUT DO NOT
THINK THERE IS MUCH OF A SEVERE THREAT.
THE HRRR HAS CONSISTENTLY SUGGESTED THAT ANOTHER CLUSTER OF
THUNDERSTORMS JUST SOUTH OF LAKE MICHIGAN WILL DIVE SOUTHEASTWARD
TOWARDS THE REGION BY MORNING. WHETHER THESE SHOWERS AND STORMS
HOLD TOGETHER REMAINS IN QUESTION BUT FOR NOW OPTED TO KEEP AT
LEAST CHANCE POPS FOR THE WESTERNMOST ZONES FOR MUCH OF THE
NIGHT...EXPANDING EASTWARD BY MORNING. WILL CONTINUE TO MONITOR
RADAR TRENDS AND ADJUST FORECAST AS NEEDED.
PRECIP CHANCES WILL CONTINUE THROUGH THE DAY ON MONDAY...INCREASING
DURING THE AFTERNOON AS INSTABILITY INCREASES WITH DAYTIME
HEATING. MOISTURE ADVECTION WILL INCREASE IN THE RESULTING
SOUTH/SOUTHWEST FLOW PUSHING PWAT VALUES BACK UP TO JUST BELOW
1.5" WHICH IS NEARLY TWO STANDARD DEVIATIONS ABOVE NORMAL FOR THIS
TIME OF YEAR. THERE IS A LARGE DIFFERENCE IN MODEL FORECAST CAPE
VALUES FOR MONDAY AFTERNOON RANGING FROM 500 TO 1500 J/KG...BUT IN
ANY CASE WITH RELATIVELY WEAK SHEAR AND STORM MOTION AROUND
15KTS...THE POTENTIAL FOR SEVERE WEATHER LOOKS LOW ATTM.
WARM ADVECTION SHOULD ALLOW FOR TEMPERATURES TO BE APPROXIMATELY
15 DEGREES ABOVE MONDAY.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
WITH THE WESTERN TOUGH SLOWLY TRANSITIONING EAST...NOT MUCH CHANGE
IS IN STORE FOR TUESDAY WITH MAX TEMPERATURES NOSING UP FURTHER
AND SHOWER/THUNDERSTORM CHANCES AGAIN MAINLY DURING THE AFTERNOON
AND EARLY EVENING. BY WEDNESDAY THE LONGWAVE TROUGH WILL HAVE
MOVED FAR ENOUGH EAST TO INCREASE DYNAMICS ACROSS THE FORECAST
AREA AND WITH PLENTY OF MOISTURE AND INSTABILITY ALREADY IN PLACE
IT LOOKS LIKELY THAT THERE WILL BE MORE WIDESPREAD THUNDERSTORM
COVERAGE. INCREASED DIRECTIONAL AND SPEED SHEAR ALOFT ALSO RAISES
THE POTENTIAL FOR MORE ORGANIZED CONVECTION BY WEDNESDAY...BUT
ATTM VALUES ARE STILL MARGINAL.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
GIVEN THE AMPLITUDE OF THE FLOW PTN PROGGED FOR THIS WEEK...EXPECT
THAT TIMING ADJUSTMENTS FOR THE EWD PROGRESS OF THE UPR TROF/CDFNT
SHOULD BE ANTICIPATED. NEVERTHELESS...THE LONG TERM FORECAST
FEATURES A CONTINUATION OF LIKELY POPS THROUGH THURSDAY FOLLOWED
BY CHC NMBRS INTO THE WEEKEND TO ACCOUNT FOR THE ADVN OF THE TROF
AND CURRENTLY PROGGED CUTOFF OVR THE GREAT LAKES REGION. PCPN AND
FRONTAL PASSAGE WL SPPRT TEMPS NR...THEN BLO THE SEASONAL AVGS FOR
THE PD.
&&
.AVIATION /01Z MONDAY THROUGH FRIDAY/...
SCT MID CLOUDS AND A CANOPY OF CIRRUS DOMINATE THE FORECAST.
SHOWERS AND THUNDERSTORMS OVER IL/IA AS OF 23Z COULD HOLD TOGETHER
AND CROSS THE REGION DURING THE EARLY MORNING HOURS MONDAY
ACCORDING TO THE HRRR. DO NOT FORESEE ANYWHERE NEAR THE INTENSITY
THEY CURRENTLY HAVE...HOWEVER A BRIEF DROP TO MVFR VIS/CIGS IS
POSSIBLE. GIVEN CONFIDENCE IS LOW...DID NOT INCLUDE ANY PCPN
MENTION IN THE TERMINALS.
SHOWERS AND THUNDERSTORMS OVER WRN OH HAVE A LOW PROBABILITY OF
IMPACTING ZZV LATER TONIGHT...IF PCPN DOES OCCUR MVFR FOG IS
POSSIBLE TOWARD DAWN MONDAY MORNING.
.OUTLOOK.../00Z TUESDAY MONDAY THROUGH FRIDAY/...
MVFR AND PERHAPS BRIEF IFR WEATHER IS POSSIBLE IN SHOWERS AND
THUNDERSTORMS ALONG AND AHEAD OF A COLD FRONT THAT CROSSES MID
WEEK.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
851 PM EDT SUN MAY 11 2014
.SYNOPSIS...
HIGH PRESSURE WILL MOVE INTO THE SOUTHEAST STATES
TONIGHT...LEADING TO WARM CONDITIONS THROUGH THE FIRST PART OF
THE WEEK. A COLD FRONT WILL MOVE INTO THE REGION WEDNESDAY AND
REMAIN OVER THE AREA THROUGH THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH MONDAY/...
HIGH PRESSURE IS LOCATED ACROSS THE MID ATLANTIC AND SOUTHEASTERN
COAST THIS EVENING. A DISTURBANCE MOVING IN ZONAL FLOW ALOFT HAS
PRODUCED SHOWERS AND THUNDERSTORMS ACROSS PARTS OF THE MIDWEST AND
CLOUD DEBRIS WILL ENTER THE POTOMAC HIGHLANDS AND CENTRAL FOOTHILLS
TONIGHT. A SUBTROPICAL RIDGE ACROSS THE GULF COAST STATES WILL
WILL PUSH NORTHWARD THROUGH THE START OF THE WORK WEEK.
HIGH PRESSURE WILL MOVE OFF THE COAST TONIGHT AND RETURN FLOW
WILL INCREASE DEWPTS OVERNIGHT AND MONDAY. MOISTURE FROM THE
ACTIVITY IN THE MID WEST WILL MOVE EASTWARD CROSSING THE OHIO
VALLEY AND NRN PORTIONS OF THE MID ATLANTIC BY SUNRISE. HI RES
MODELS HAVE SHOWERS DISSAPATING AS THEY REACH THE POTOMAC
HIGHLANDS LATE TONIGHT.
THE MID ATLANTIC WILL BE LOCATED ON THE NORTHERN EDGE OF A
NORTHWARD ADVANCING SUBTROPICAL RIDGE MONDAY. DAYTIME HEATING WILL
RESULT IN A CU FIELD ACROSS THE REGION AND SHOWERS AND
THUNDERSTORMS ARE POSSIBLE ALONG THE HIGHER ELEVATIONS SUCH AS THE
POTOMAC HIGHLANDS AND BLUE RIDGE BY MIDDAY. A LEE TROUGH IS ALSO
EXPECTED TO FORM ALONG AND EAST OF THE BLUE RIDGE BY MONDAY
AFTERNOON WHICH MAY PRODUCE A ZONE FOR CONVECTIVE DEVELOPMENT.
WESTERLY FLOW ALOFT WILL LEAD TO THE POTENTIAL OF THIS ACTIVITY TO
MOVE EASTWARD AND REACH THE I-95 CORRIDOR BY MONDAY AFTERNOON. NAM
FCST SOUNDINGS SHOW A SLIGHT CAP BUT GFS AND RAP SHOW LITTLE
INHIBITION ACROSS THE REGION TOMORROW. SFC DEWPTS AND CLOUD COVER
WILL BE FACTORS IN THE COVERAGE OF SHOWERS AND THUNDERSTORMS EAST
OF THE BLUE RIDGE BUT AT THIS TIME DEWPTS ARE FCST TO REACH THE
LOW TO MID 60S EAST OF THE BLUE RIDGE. THIN CLOUD DEBRIS IS
EXPECTED ACROSS THE REGION BY MONDAY MORNING DUE TO THE ACTIVITY
IN THE MIDWEST. THE AIRMASS OVER THE MIDWEST TONIGHT WILL BE
MOVING OVER THE MID ATLANTIC MONDAY SETTING THE STAGE FOR THE
POTENTIAL FOR SHOWERS AND POSSIBLY THUNDERSTORMS. THE SVR THREAT
IS LOW DUE TO WEAK FORCING AND MARGINAL INSTABILITY AND SHEAR.
TEMPS WILL RISE INTO THE MID TO UPPER 80S MONDAY AFTERNOON AND A
RIVER/BAY BREEZE MAY ALSO PRODUCE LOW LEVEL CONVERGENCE TO FORM
SHOWERS AND POSSIBLY THUNDERSTORMS.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
IN TERMS OF CONVECTIVE INSTABILITY OVER A MULTI-DAY PERIOD...THE
NEXT FEW DAYS WILL BE THE MOST UNSTABLE FOR OUR REGION SO FAR THIS
YEAR. THE PASSAGE OF ANY ORGANIZED SYNOPTIC-SCALE FEATURE WILL BE A
SLOW BOIL HOWEVER...W/ EACH DAY FOR THE UPCOMING WORK WEEK HAVING
THE POTENTIAL FOR SOME WEAK CONVERGENCE/DIURNAL CONVECTION. AN
OFFSHORE HIGH WILL SUPPLY THE MUCH-ABOVE AVG TEMPS AND MOISTURE. A
DEEPENING UPPER TROUGH TO OUR WEST WILL SUPPLY THE GRADUALLY
ENVIRONMENT FOR STEEPER LAPSE RATES. DESPITE THESE MORE FAVORABLE
CONVECTIVE CONDITIONS...ONLY LOCAL-SCALE AND/OR WEAK CONVERGENCE
ZONES WILL HELP DEVELOP OUR SHOWER/TSTM CHANCES FOR THE NEXT FEW
DAYS.
AFTER SOME SCATTERED/ISOLATED TSTMS ON MON-MON EVE...CONDITIONS WILL
SETTLE DOWN AGAIN W/ A WARM OVERNIGHT THAT WILL SET US UP FOR
ANOTHER HOT DAY ON TUE. WHILE MIDWEST AND MS VLY ARE UNDER THE
CONVECTIVE CROSSHAIRS MON-TUE...A NEARBY WARM FRONT AND SOME WEAK
LEE TROUGH ACTIVITY WILL HELP DEVELOP TSTMS OVER THE MID ATLC ON TUE
AFTN. GIVEN SOME CONVECTION INITIATION...THERE WILL BE AMPLE
INSTABILITY FOR INDIVIDUAL CELLS TO PRODUCE STRONG-SEVERE WX IN
ISOLATED AREAS. WE`LL BE EXPERIENCING SOME OF THE HIGHEST DEWPOINTS
OF THE YEAR SO FAR ON TUE AFTN. COUPLE THAT W/ TEMPS ON DOORSTEP OF
THE 90F MARK AND WE`LL SEE SOME OF THE WARMEST HEAT INDICES OF THE
YEAR...POTENTIALLY IN THE M90S.
THE FRONTAL SYSTEM CAUSING LIKELY WIDESPREAD CONVECTION A COUPLE OF
STATES TO OUR WEST ON TUE WILL BREAK OFF FROM ANOTHER UPPER WAVE
OVER THE SRN PLAINS AND TAKE OFF TO THE NE - WELL AWAY FROM OUR
AREA. THE COLD FRONT WON`T EVEN PASS OVER OUR AREA AS THE SRN PLAINS
UPPER WAVE GEARS-UP TO DEVELOP IT`S OWN LOW PRESSURE SYSTEM. A SFC
HIGH WILL DEVELOP OFF THE NEW ENGLAND COASTLINE LATE TUE INTO
WED...SETTING-UP AN ONSHORE ELY FLOW OVER THE MID ATLC - ADDING SOME
STABILITY AND COOLER CONDITIONS FOR AREAS E OF THE BLUE RIDGE ON
WED. TEMPS WILL TAKE A BREAK FROM THE U80S ON WED...LIKELY
STRUGGLING TO REACH THE L80S - OUTSIDE OF THE LOWER SHEN VLY/VA
PIEDMONT. TSTMS WILL STILL BE POSSIBLE ACROSS THE AREA LATER IN THE
DAY AS THE ONSHORE FLOW SUBSIDES AND SOME HEATING PUSHES THRU THE
MARINE LAYER.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
STILL LOOKING GOOD FOR POTENTIAL HEAVY RAIN THURSDAY DESPITE SOME
TIMING DIFFERENCES IN GFS/ECMWF WITH FROPA. LONG SOUTHERLY FETCH
AHEAD OF DEEP LONG WAVE TROUGH DRAWS IN AMPLE MOISTURE FROM
GULF/CARIBBEAN THROUGH MID WEEK. MOISTURE AXIS IMPINGING LOW LEVEL
THERMAL BOUNDARY WILL PROVIDE FOCUSED LOW LEVEL LIFT AND SOUTHERLY
SHORT WAVE LIFTING NORTH ON THE FRONT SIDE OF THE UPPER TROUGH WILL
PROVIDE SYNOPTIC LIFT FOR NUMEROUS SHOWERS/STORMS THURSDAY. FORECAST
SOUNDINGS SHOW THIN CAPE PROFILES AND DEEP WARM CLOUD
LAYER...FAVORABLE FOR COLLISION-COALESCENCE HEAVY RAIN PROCESSES.
THE FRONT IS SOMEWHAT PROGRESSIVE HOWEVER WHICH LOOKS TO HINDER
TRAINING ECHOES AS DRY AIR PUSHES IN POST COLD FRONT LATE THURSDAY
NIGHT INTO FRIDAY. COOLER AIRMASS BUILDS IN AS UPPER TROUGH MOVES
ACROSS THE GREAT LAKE FRIDAY INTO THE WEEKEND. THIS COOLER POOL
ALOFT COMBINED WITH DAYTIME SURFACE HEATING MAY PRODUCE SOME
INSTABILITY CONVECTION AND HAVE MAINTAINED POPS FOR THIS SHOWER
POTENTIAL.
&&
.AVIATION /01Z MONDAY THROUGH FRIDAY/...
HIGH PRESSURE WILL CONTINUE ACROSS THE AREA TONIGHT BEFORE MOVING
OFF THE EAST COAST BY MONDAY. NO VIS/CIG FLIGHT RESTRICTIONS
EXPECTED DURING THE VALID TAF PERIOD. SHOWERS AND THUNDERSTORMS
MAY FORM AT HIGHER ELEVATIONS BY MONDAY AFTERNOON AND A FEW MAY
MOVE INTO THE TAF SITES BY SUNSET. SOUTHERLY WINDS EXPECTED
THROUGH TUESDAY.
WHILE A LARGE-SCALE LOW PRESSURE TROUGH BUILDS WELL TO OUR WEST
EARLY THIS WEEK...THE EASTERN SEABOARD WILL WARM-UP AND THE
ENVIRONMENT WILL BECOME MORE UNSTABLE. DAYTIME HEATING WILL PROVIDE
THE SET-UP FOR CONVECTIVE POTENTIAL BUT THE TRIGGER FOR DEVELOPING
SHOWERS AND TSTMS WILL BE LIMITED. A CHANCE OF PRECIP POSSIBLE
THROUGHOUT MUCH OF THE WEEK...THOUGH THE FIRST HALF WILL BE THE
WARMEST PERIOD. A SLOW MOVING COLD FRONT IS EXPECTED TO BRING UNSETTLED
WEATHER WITH CHANCES OF STORMS/HEAVY RAIN FOR MAINLY THURSDAY AND
THURSDAY NIGHT.
&&
.MARINE...
HIGH PRESSURE SHIFTS SOUTH OF THE WATERS TONIGHT. WEAK NW WIND WILL
BECOME TO THE S BY EVENING. S WINDS LIKELY INCREASE TONIGHT INTO
MONDAY...POSSIBLY TO AROUND 15 KT UP THE BAY. BUT WITH RELATIVELY
WEAK GRADIENT...SCA CONDITIONS ARE NOT EXPECTED AT THIS TIME. A
FEW SCT SHOWERS ARE POSSIBLE ACROSS THE WATERS LATE MONDAY
AFTERNOON INTO EARLY EVENING.
HIGH PRESSURE WILL BE IN PLACE FOR THE FIRST HALF OF THE WEEK...
KEEPING THE WATERS RELATIVELY QUIET. SOME SLY CHANNELING LATE MON
INTO TUE...W/ THE MAIN THREATS BEING POTENTIAL TSTMS EACH AFTN/EVE
THRU MID WEEK. UNSETTLED WEATHER CONDITIONS WITH CHANCES OF
STORMS/HEAVY RAIN ARE EXPECTED MAINLY THURSDAY AND THURSDAY NIGHT
DUE TO A SLOW MOVING COLD FRONT.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...BPP
NEAR TERM...BPP/HAS
SHORT TERM...GMS
LONG TERM...AEB
AVIATION...HAS/GMS/AEB
MARINE...HAS/GMS/AEB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
751 PM EDT SUN MAY 11 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 347 PM EDT SUN MAY 11 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW STRONG SHORTWAVE ENERGY
ROUNDING BASE OF AMPLIFIED TROF OVER THE FOUR CORNERS REGION OF THE
SW CONUS. MODELS SHOW THIS STRONG SHORTWAVE BEGINNING TO EJECT NE
FROM WRN/CENTRAL PLAINS TONIGHT AS ITS ASSOC SFC LOW LIFTS NE
THROUGH THE PLAINS. INCREASING MOISTURE AND ISENTROPIC ASCENT AHEAD
OF THIS LOW PRES SYSTEM SHOULD SIGNAL THE BEGINNING OF A FAIRLY WET
PERIOD FOR THE CWA STARTING LATE TONIGHT AND CONTINUING INTO EARLY
TUESDAY.
TONIGHT...AS THE STRONGER SHORTWAVE BEGINS TO EJECT OUT OF THE
DEEPENING UPPER TROF THE SFC LOW PRES WILL IN TURN LIFT NE THRU THE
PLAINS. THE EVENING SHOULD REMAIN DRY...AND PERHAPS CONTINUE INTO
THE OVERNIGHT OVER THE NE HALF OF THE FCST AREA CLOSER TO DRY
LOW-LEVEL NE TRAJECTORIES OUT OF SFC HIGH PRES IN ONTARIO. MOST OF
THE MODELS SHOW INCREASING 850-700 MB MOISTURE TRANSPORT AND
ADVECTION INTO THE AREA FM THE SOUTH BTWN 06-12Z ALONG WITH
INCREASING 300-305K WAA/ISENTROPIC ASCENT AHEAD OF THE APPROACHING
LOW PRES SYSTEM. MODELS ALSO INDICATE A SUBTLE SHORTWAVE WILL LIFT
NE INTO THE UPPER MISSISSIPPI VALLEY LATE TONIGHT THAT WILL FURTHER
AID THE DEVELOPMENT/SPREAD OF SHRA NE INTO UPPER MI DURING THE
OVERNIGHT. NOT MUCH INSTABILITY IS NOTED PER 0-3KM MUCAPE OFF THE
NAM/GFS. WITH A COUPLE HUNDRED J/KG AND SHOWALTER INDEX FALLING JUST
BLO 0C OVER THE FAR SCNTRL LATE TONIGHT IN MOST MODEL
GUIDANCE...WILL CONTINUE THE MENTION OF THUNDER IN THAT AREA LATE
TONIGHT.
MONDAY...WITH H85 WARM FRONT IN THE VICINITY...MODELS SHOW CONTINUED
MOISTURE TRANSPORT/ADVECTION AT H85-H7 ACROSS THE FRONTAL BOUNDARY
AS PWATS OVER OUR AREA RISE TO AROUND 1.5 INCHES OR WELL OVER 200
PCT OF NORMAL. SHORTWAVE/PV ANAMOLY EMERGING NORTHEAST OUT OF THE
WESTERN CONUS TROUGH WILL SPREAD AREA OF H85-H5 Q-VECTOR CONVERGENCE
INTO THE UPPER GREAT LAKES BY MONDAY AFTERNOON. DESPITE THESE
FAVORABLE FACTORS FOR SHOWERS...MODELS STILL DIFFER SOMEWHAT ON
PLACEMENT OF MAXIMUM MOISTURE ADVECTION...WITH THE GFS AND NAM
INDICATING BEST MOISTURE ADVECTION WEST AND THE REG GEM TO THE
EAST. HOWEVER CORFIDI VECTORS...BOTH FORWARD AND BACKWARD
PROPAGATING...ARE GENERALLY ORIENTED FROM WEST TO EAST ACROSS THE
FCST AREA WHICH WOULD ARGUE SHOWERS MAKING IT INTO THE WRN FCST AREA
SHOULD ADVECT INTO THE ERN COUNTIES AS WELL. GOING FCST LIKELY POPS
STILL SEEM REASONABLE CONSIDERING THE H85 FRONT IS IN THE VICINTY.
WILL CONTINUE IDEA OF LIKELY POPS WEST IN THE MORNING SPREADING EAST
INTO THE AFTERNOON HRS. ALSO WILL CONTINUE TO KEEP MENTION OF
TSRA MAINLY OVER SOUTH HALF INTO THE WESTERN CWA ALONG NORTHERN
GRADIENT OF ELEVATED INSTABILITY WITH SEVERAL HUNDRED J/KG OF
ELEVATED CAPE AND NEG SHOWALTER INDICES. BIGGEST THREAT WITH ANY
TSRA WILL BE HEAVY RAIN GIVEN HIGH PWATS ACROSS AREA. ANY HEAVY RAIN
OVER THE WRN COUNTIES WILL CONTINUE TO ADD MORE RUNOFF TO RIVERS
ALREADY RUNNING NEAR BANKFULL...ESPECIALLY THE STURGEON...TRAP ROCK
AND MICHIGAMME RIVERS.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 329 PM EDT SUN MAY 11 2014
AT THE START OF THE PERIOD /00Z TUE/ MODELS ARE IN DECENT LARGE
SCALE AGREEMENT IN SHOWING A SHARP AND DEEP 500MB TROUGH FROM THE
SASK/MANITOBA BORDER S ACROSS THE DAKOTAS THEN TO THE FOUR CORNERS
REGION. A 1004MB SFC LOW WILL BE SOMEWHERE IN THE SERN MN TO NWRN
WI. MODELS HAVE BEEN TRENDING TOWARD THE CURRENT SOLUTION THAT TAKES
THE SFC LOW W OF THE CWA TO JUST N OF THE MN ARROWHEAD BY 12Z TUE.
WITH THE MORE NLY TRACK...MODELS ARE NOW SHOWING THE SFC WARM FRONT
MOVING INTO THE FAR SRN CWA MON NIGHT...BUT WITH COLD LAKE TEMPS AND
CONVECTION EXPECTED ALONG THE FRONT...CONFIDENCE IN THE FRONT MOVING
THAT FAR N IS LOW. FORCING FROM UPPER LEVEL HEIGHT FALLS FROM THE
DEEPENING TROUGH...GOOD MOISTURE TRANSPORT AND ISENTROPIC ASCENT
WILL FAVOR PERIODS OF MODERATE RAIN SHOWERS MON NIGHT INTO EARLY
TUE. THE OCCLUDED/COLD FRONT WILL MOVE THROUGH FROM LATE MON NIGHT
INTO TUE...BRINGING AN END TO THE BULK OF THE PRECIP. SOME SHOWERS
COULD REDEVELOP BEHIND THE FRONT AS CLEARING OVER THE WRN U.P. MAY
ALLOW FOR ENOUGH INSTABILITY. MODELS GENERALLY SHOW ADDITIONAL QPF
AMOUNTS OF AN INCH...BUT THAT WILL BE HIGHLY DEPENDENT ON EXACT
DETAILS OF CONVECTION...MAKING EXACT PRECIP AMOUNTS HIGHLY
UNCERTAIN. INSTABILITY FOR CONVECTION WILL ALSO BE HIGHLY UNCERTAIN
DUE TO DEPENDENCY ON WARM FRONTAL LOCATION AND OTHER CONVECTION. IF
THE FRONT CAN MAKE IT FARTHER N...THE WARM NOSE AT 900MB MAY BE
STRONG ENOUGH TO LEAD TO GREATER ELEVATED CONVECTION. GFS AND NAM
ARE SHOWING UP TO AROUND 1000 J/KG OF ELEVATED CAPE OVER THE
SCENTRAL CWA...BUT STILL THINK THAT IS NOT AS LIKELY AS THE FRONT
WILL PROBABLY STAY FARTHER S. IF THE WORST CASE SCENARIO OF THE
FARTHER N FRONTAL POSITION DOES OCCUR...SOME HAIL WOULD BE POSSIBLE
SCENTRAL. THE ADDITIONAL QPF AMOUNTS /COMBINED WITH PRECIP ON MON/
WOULD LIKELY LEAD TO ADDITIONAL FLOODING CONCERNS ON AREA RIVERS
THAT ALREADY HAVE ELEVATED LEVELS.
THE UPPER TROUGH MOVES OVERHEAD THROUGH MUCH OF THE REST OF THE WORK
WEEK...ALTHOUGH THE ECMWF CLOSES IT OFF INTO A LOW THU INTO FRI. THE
ECMWF SOLUTION WOULD RESULT IN MORE WIDESPREAD PRECIP THU INTO
FRI...BUT THE GFS AND GEM SOLUTIONS WITH THE OPEN TROUGH WOULD LEAD
TO SCATTERED SHOWER ACTIVITY MAINLY DURING PEAK HEATING WED THROUGH
FRI. THIS DUE TO 850MB TEMPS OF -2C TO -4C WED THROUGH FRI NIGHT
/AND AS COLD AS -7C IF THE ECMWF SOLUTION PANS OUT/. OF
COURSE...THIS WILL LEAD TO A RETURN OF SIGNIFICANTLY BELOW NORMAL
TEMPS /10-15 DEGREES BELOW NORMAL/.
NEXT WEEKEND LOOKS DRIER AND WARMER AS RIDGING MOVES OVERHEAD.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 751 PM EDT SUN MAY 11 2014
LINGERING DRY AIR AT THE LOW LEVELS WILL ENSURE VFR CONDITIONS
THROUGH THIS EVENING. LATE TONIGHT...NORTHWARD ADVANCING LOW
PRESSURE AND A WARM FRONT WILL SPREAD SHRA INTO UPPER MI. THERE
IS STILL SOME UNCERTAINTY IN HOW FAST PCPN WILL DEVELOP. KIWD HAS
THE BEST CHC OF CONDITIONS FALLING TO MVFR AROUND 08Z WITH THE ONSET
OF RAIN. EXPECT ALL SITES TO QUICKLY FALL TO IFR OR LIFR IN LOWERING
STRATUS BY 12Z OR SHORTLY THEREAFTER WITH CONTINUED SHOWERS AND
ADVECTION OF HIGHER DEWPOINTS INTO THE AREA.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 347 PM EDT SUN MAY 11 2014
NE WINDS 15-25 KTS THIS EVENING WILL BEGIN TO INCREASE OVER WESTERN
PORTIONS OF LK SUPERIOR LATE TONIGHT AND MORE SO ON MONDAY AS LOW
PRESSURE APPROACHES FROM THE SOUTHWEST. DECIDED TO REPLACE GALE
WATCH WITH GALE WARNING OVER WESTERN TWO ZONES LATE TONIGHT THROUGH
TUE EVENING. WINDS OVER THE REST OF THE LAKE WILL STAY AT OR BLO 30
KTS. WINDS DIMINISH LATER MONDAY NIGHT AND THEN SWITCH TO THE WEST
TO 20-25 KTS ON TUESDAY. LOW SLOWLY SLIDES TO THE NORTHEAST OF LK
SUPERIOR REST OF THE WEEK...RESULTING IN NORTHWEST WINDS MAINLY
STAYING BLO 20 KTS.
&&
.HYDROLOGY...
ISSUED AT 329 PM EDT SUN MAY 11 2014
HIGHS MOSTLY IN THE 60S TODAY WILL RESULT IN ADDITIONAL SNOWMELT
OVER HIGHER TERRAIN OF NORTHERN UPR MICHIGAN. MINIMAL RAIN AMOUNTS
ARE EXPECTED THROUGH AT LEAST EARLY TONIGHT...BUT RAIN CHANCES
INCREASE LATE TONIGHT INTO TUESDAY MORNING. THERE IS A POTENTIAL FOR
MODERATE TO HEAVY RAIN OVER THE AREAS THAT ARE STILL MELTING
SNOW...SO THE RECENT HIGHER RIVER LEVELS WILL CONTINUE THROUGH MUCH
OF THE UPCOMING WEEK. THE FLOOD WARNING CONTINUES FOR THE STURGEON
RIVER NEAR CHASSELL...WHILE ADVISORIES ARE IN PLACE FOR OTHER
PORTIONS OF THE STURGEON RIVER IN HOUGHTON AND BARAGA COUNTIES AS
WELL AS PORTIONS OF THE MICHIGAMME RIVER. IF HEAVIER RAINS
MATERIALIZE EARLY THIS WEEK... ADDITIONAL ADVISORIES AND WARNINGS
MAY BE NEEDED. THOSE LIVING NEAR RIVERS...CREEKS...AND STREAMS
SHOULD CONTINUE TO MONITOR THE LATEST RIVER LEVELS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 6 AM EDT /5 AM CDT/ MONDAY TO MIDNIGHT EDT /11
PM CDT/ MONDAY NIGHT FOR LSZ162.
GALE WARNING FROM 10 AM TO 11 PM EDT MONDAY FOR LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...TITUS
AVIATION...JLB
MARINE...VOSS
HYDROLOGY...TITUS
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1202 AM EDT SAT MAY 10 2014
.AVIATION...
//DISCUSSION...
THE COLD FRONT WILL BE THROUGH ALL TERMINAL LOCATIONS TO START THE
FORECAST LEAVING A CLEARING TREND BEHIND THROUGH THE EARLY MORNING.
THE EXCEPTION WILL BE IN THE MBS AREA WHERE A FIELD OF VFR STRATUS
WILL SPREAD IN FROM WESTERN LOWER MICHIGAN. TRENDS IN SATELLITE
IMAGERY SUGGEST IT WILL NOT BE ABLE TO REACH SOUTH OF FNT BEFORE
MOVING INTO ONTARIO TOWARD SUNRISE. THE CLOUDS WILL BE DRIVEN OUT OF
THE AREA BY HIGH PRESSURE BUILDING IN DURING THE MORNING. THE HIGH
PRESSURE WILL BRING IN AND MAINTAIN VFR CONDITIONS THROUGH SATURDAY
EVENING.
//DTW THRESHOLD THREATS...
* NONE.
&&
.PREV DISCUSSION...ISSUED 945 PM EDT FRI MAY 9 2014
UPDATE...
SURFACE ANALYSIS AND OBSERVATIONS INDICATE THE COLD FRONT SURGING
THROUGH THE TRI CITIES AND ABOUT TO PASS THROUGH FLINT AT PRESS
TIME. THE FRONT WILL SUPPORT A FEW MORE POCKETS OF SHOWERS AND
THUNDERSTORMS BUT THE STRENGTH OF ANY STORMS WILL BE LIMITED BY
INSTABILITY WANING AFTER SUNSET. EARLIER UPDATES SHIFTED THE FOCUS
ON PRECIPITATION FROM THE PREFRONTAL LINE EXITING INTO ONTARIO TO
THE ACTUAL COLD FRONT FOR THE REST OF THE EVENING. EXPECT THE
FRONT TO BE THROUGH THE ENTIRE AREA SHORTLY AFTER MIDNIGHT AND
LEAVE SE MICHIGAN WITH DRY CONDITIONS AND A CLEARING TREND THROUGH
THE EARLY OVERNIGHT. THIS WILL BE FOLLOWED BY STRATUS MOVING IN
FROM WISCONSIN AND WESTERN LOWER MICHIGAN LATER IN THE NIGHT THAT
SHOULD MOVE OVER MOST OF THE REGION NORTH OF INTERSTATE 69. THESE
CLOUD EXPECTATIONS WILL BE REFINED WITH ONE MORE UPDATE TO COVER
TRENDS THROUGH SATURDAY MORNING.
PREV DISCUSSION...ISSUED 400 PM EDT FRI MAY 9 2014
SHORT TERM...THIS EVENING AND TONIGHT
CLOUDS AND SHALLOW EARLY AFTERNOON CONVECTION HAVE RESULTED IN A
RATHER NEBULOUS PICTURE FOR THUNDERSTORM POTENTIAL THIS EVENING.
ABUNDANT MID AND HIGH CLOUDS HAVE LIMITED BOUNDARY LAYER RECOVERY IN
THE WAKE OF THE PASSING CONVECTION, ALTHOUGH MID 70S TEMPS AND
DEWPOINTS AROUND 60 ARE MAKING A RENEWED PUSH INTO SOUTHWEST LOWER
MICHIGAN DURING THE MID AFTN AND CLOUD OPACITY IS DECREASING.
MESOANALYSIS SHOWS MUCAPES AT A RATHER MODEST 500 J/KG OVER WESTERN
LOWER FOR NOW...BUT THE 12Z NAM AND RECENT RUNS OF THE RUC SUGGEST A
RECOVERY TO 1000 J/KG CAPE BY AROUND 22Z IN ADVANCE OF THE
APPROACHING COLD FRONT. THE OVERZEALOUS HANDLING OF QPF BY TODAY`S
NWP MAKES THE PROGGED RECOVERY ALL THE MORE IMPRESSIVE. HOWEVER, IN
AND AN ATTEMPT TO ADDRESS UNCERTAINTIES REGARDING BOTH THE MID-LEVEL
AND LOW-LEVEL THERMODYNAMIC ENVIRONMENT RESULTING FROM BOTH POOR
MODEL PERFORMANCE AND EARLY CONVECTION, A SPECIAL SOUNDING WAS
LAUNCHED AT APPROXIMATELY 1930Z. THE DATA WILL BECOME AVAILABLE
SHORTLY AFTER ISSUANCE OF THE AFTERNOON PACKAGE. FINALLY, ALTHOUGH
ANY CONVECTION THAT BUBBLES UP IN ADVANCE OF THE FRONT MAY BEGIN TO
LOOSE FOOTING IN THE BOUNDARY LAYER AROUND 00Z...STEEPENING
MID-LEVEL LAPSE RATES WILL MAINTAIN RESPECTABLE MID-LEVEL
INSTABILITY WELL INTO THE EVENING HOURS AND MAY EVEN ALLOW A HAIL
THREAT TO DEVELOP IN ADDITION TO WIND AS UPDRAFTS ARE ALLOWED TO
DEEPEN. WIDESPREAD SEVERE WEATHER IS NOT EXPECTED...PARTICULARLY
GIVEN PARALLEL NATURE OF THE MEAN FLOW TO THE INITIATING
BOUNDARY...BUT AT LEAST A MARGINAL THREAT WILL EXIST DEPENDING ON
THE BEHAVIOR OF INDIVIDUAL CELLS. WILL MAINTAIN CHANCE POPS
THROUGH THE EVENING HOURS AND MENTION A RISK OF AT LEAST ISOLATED
WIND/HAIL THREATS DEVELOPING OVER THE NEXT SEVERAL HOURS IN THE HWO.
THE GREATEST THREAT WILL BE FOCUSED FURTHER SOUTH AND WEST WHERE
INSTABILITY WILL BE MAXIMIZED.
LONG TERM...
DIFFERENTIAL HEIGHT RISES BEHIND THE DEPARTING SHARP MIDLEVEL
TROUGH AXIS WILL LEAD TO A SURFACE RIDGE ACROSS SOUTHEASTERN
MICHIGAN ON SATURDAY. DRYING SIGNAL IN THE 925-850MB LAYER SUPPORTS
THE FORECAST SOUNDINGS OF LCL HEIGHTS EVENTUALLY REACHING A VERY
HIGH 6000 FT AGL. THE ENVIRONMENT FAVORABLE FOR DEEP TURBULENT
MIXING WILL EVENTUALLY ALLOW BREEZY WESTERLIES TO DEVELOP DURING
THE LATE AFTERNOON. SURFACE WIND GUSTS ARE EXPECTED TO REACH 25 TO
30 KNOTS. FORECASTED SOUNDINGS FOR SATURDAY ARE NOW QUITE A BIT
DIFFERENT WITH ANY EXPECTED MIDLEVEL LAPSE RATES. IN FACT...POCKET
OF STEEP MIDLEVEL LAPSE RATES IS NOWHERE TO BE SEEN...SUGGESTING
THAT EVEN A SCATTERED CU FIELD WILL BE DIFFICULT. HIGHS SATURDAY
WILL BE COOLER...READING REACHING THE UPPER 60S FOR MANY AREAS...72
OR 73 DEGREES FOR THE HIGHER SURFACE PRESSURE/LOWER TERRAIN
LOCATIONS ACROSS THE EXTREME SOUTHEAST.
THE INBOUND LONGWAVE RIDGE WILL BE VERY PROGRESSIVE DURING THE
LATTER HALF OF THE WEEKEND...AMPLIFYING AS WELL. PRECEDING MID TO
UPPER LEVEL TROPOSPHERIC DEFORMATION IS PROGGED TO BE VERY GOOD
WHICH WILL AID IN THE RAPID DEVELOPMENT OF A WARM FRONT BY SUNDAY.
EARLY PART OF THE DAY IS EXPECTED TO BE QUIET WITH VERY DRY AIR IN
RESIDENCE DURING THE MORNING. WIND TRAJECTORIES WILL EVENTUALLY VEER
SOUTHWESTERLY WHICH WILL ALLOW WARMTH AND INSTABILITY TO INCREASE
FOR THE AFTERNOON. THE SUNDAY PERIOD HAS BEEN A NOISY ONE WITHIN THE
MODELS SO CONFIDENCE IS NOT OVERLY HIGH...ESPECIALLY WITH REGARDS TO
TIMING. HOWEVER...ENOUGH UPPER LEVEL FORCING APPEARS TO BE COMING
TOGETHER SUPPORTIVE OF A MID CHANCE POP IN THUNDERSTORMS FOR THE
SOUTHERN HALF OF THE CWA. THE LATE AFTERNOON PUSH WITH WARMTH WILL
ALLOW TEMPERATURES TO REACH THE MID 70S FOR MANY LOCATIONS.
MONDAY WILL BEGIN A PERIOD OF ACTIVE WEATHER FOR THE EXTENDED AS A
WARM FRONT LIFTS NORTH INTO THE TRI CITIES AREA. AGAIN...WARM AND
MOIST AIR WILL ADVECT NORTH VIA A 40KT H85 JET. THIS WILL BRING PWAT
VALUES OVER 1.5 INCHES. WILL CONTINUE TO TREND UPWARD WITH POPS 50
TO 60 PERCENT. THE COLD FRONT WILL SWING THROUGH ON TUESDAY AND
CONTINUE THE HIGH POP EVENT. BOTH DAYS POSE THE THREAT FOR THUNDER
AS LI/S WILL BE NEGATIVE. MUCH LIKE THE PAST 2 DAYS HERE...MONDAY IN
THE WARM SECTOR WILL REMAIN CAPPED BUT WITH CAPE WELL OVER 2500
J/KG. TUESDAY WILL HAVE MORE POTENTIAL WITH THE STRONGER
FORCING...BUT LOWER CAPE VALUES. CHANCE POPS WILL ALSO BE IN THE
FORECAST WEDNESDAY AS REMNANT MOISTURE FROM THE SLOW CHURNING LOW
PRESSURE REMAINS PROXIMAL TO THE AREA. THIS WILL BE ALONG WITH A
GENERAL THUNDER THREAT. THE REST OF THE PERIOD STILL LOOKS TO REMAIN
COOL WITH TEMPS BELOW CLIMO.
MARINE...
A STRONGLY STABLE PROFILE OVER THE GREAT LAKES WILL KEEP WIND GUSTS
MAINLY UNDER 30 KNOTS. THE COLD FRONT WILL TRACK ACROSS LAKE HURON
THIS EVENING AND WILL BE MARKED BY A VEERING OF THE WIND TO THE
SOUTHWEST. THE POST FRONTAL COLD AIR ADVECTION IN THE WAKE OF THE
FRONT WILL NOT BE SIGNIFICANT ENOUGH TO OVERCOME THE STRONG OVER
LAKE STABILITY. THUS WINDS WILL REMAIN MAINLY UNDER 25 KNOTS ON
SATURDAY. WINDS WILL QUICKLY DIMINISH SATURDAY NIGHT AS SFC HIGH
PRESSURE MOVES OVER THE LAKES. A WARM FRONT WILL SLOWLY LIFT ACROSS
THE REGION SUN NIGHT THROUGH MONDAY NIGHT. THE CONTINUED STRONG
STABILITY WILL KEEP WINDS AND WAVES IN CHECK. HOWEVER...THERE WILL
BE A GOOD CHANCE FOR THUNDERSTORMS THROUGH THE PERIOD.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....BT
UPDATE.......BT
SHORT TERM...JVC
LONG TERM....CB/MM
MARINE.......CB
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
759 PM CDT SUN MAY 11 2014
.UPDATE...
ISSUED AT 725 PM CDT SUN MAY 11 2014
UPDATED TO INCLUDE 00Z AVIATION DISCUSSION BELOW.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 355 PM CDT SUN MAY 11 2014
EARLY AFTERNOON WATER VAPOR IMAGERY TOGETHER WITH RAP 500MB
HEIGHTS AND WINDS IDENTIFIED A VIGOROUS SHORTWAVE ROTATING OVER
THE 4-CORNERS REGION...WITH AN MCS ONGOING IN EASTERN IA. VISIBLE
SATELLITE SHOWED CLEARING BEHIND THIS MCS...AND THE SURFACE OBS
HAVE ALREADY REFLECTED THE BOUNDARY LAYER DESTABILIZATION AS
TEMPERATURES HAVE INCREASED 5DEG/HR BUT KEPT THE EASTERLY
COMPONENT IN THE WIND FIELD.
THIS WIND SHIFT MARKED THE STOUT FRONTAL BOUNDARY WHICH WILL
BE THE FOCUS FOR TORNADOES LATER THIS AFTERNOON ACROSS EASTERN NE
AND WESTERN IA. TEMPERATURES WERE IN THE MID 80S SOUTH OF THIS
WARM FRONT WITH SOUTHERLY WINDS...WHILE NORTH OF THE WARM FRONT
TEMPERATURES WERE IN THE LOW TO MID 70S WITH DEWPOINTS IN THE MID
60S. THE MLCAPE GRADIENT MIRRORED THE POSITION OF THE EAST/WEST
ORIENTED WARM FRONT...BUT INSTABILITY WAS BUILDING WELL NORTH OF
THE FRONT AS EVIDENT BY THE 3HR SBCAPE CHANGE ON THE SPC
MESOANALYSIS PAGE. THE FINAL POSITION OF THE WARM FRONT WILL
DICTATE WHERE THE SURFACE BASED STORMS ARE...AND THUS THE BEST
THREAT FOR TORNADOES. AT THIS TIME IT APPEARS THAT THE THREAT WILL
REMAIN WELL SOUTH OF THE CWA.
HOWEVER...THE LAST FEW RUNS OF THE HRRR AND HOPWRF INDICATE THAT A
FEW ELEVATED STORMS ARE EXPECTED AFTER 00Z ACROSS THE SOUTHERN
PART OF THE FORECAST AREA. THESE STORMS WILL HAVE 1000-1500J/KG OF
MUCAPE TO WORK WITH DEEP SHEAR FAVORABLE FOR ORGANIZED CONVECTION.
A FEW STORMS WILL HAVE THE POTENTIAL FOR PRODUCE SEVERE
HAIL...MAINLY ALONG THE I-90 CORRIDOR. HEAVY RAIN IS ALSO A
THREAT...PERHAPS MORESO THAN THE SEVERE WEATHER. AT THIS TIME...IT
APPEARS THAT THE HEAVIEST RAINFALL WILL FALL JUST SOUTH AND EAST
OF THE FORECAST AREA ALONG A LINE FROM OMAHA TO LA CROSSE WI. IT
IS WITHIN THIS LINE THAT A HP SUPERCELLS ARE EXPECTED WHICH WILL
BE CAPABLE OF PRODUCING 2-3IN/HR RAINFALL RATES AND FLASH FLOODING
GIVEN THE RAINFALL THAT OCCURRED EARLIER THIS MORNING. IN OUR
CWA...WE DID NOT HAVE THE MORNING RAINFALL...AND SUPERCELLS APPEAR
LESS LIKELY...SO ALTHOUGH WE MAY GET A QUICK 1-2 INCHES OF RAIN
WITH A FEW OF THE HEAVIER CELLS...THIS IS ABOVE FLASH FLOOD
GUIDANCE. THEREFORE HAVE OPTED TO HOLD OFF ON A FLOOD WATCH FOR
NOW. TO TIE BACK INTO THE HIRES MODELS...THE PROGRESSIVE NATURE OF
THE EASTWARD MOVING STORMS ALSO SUPPORTS NOT ISSUING A FLOOD
WATCH.
THERE WILL BE A LULL IN THE PRECIP ACROSS CENTRAL MN AS THE
SURFACE LOW TRACKS NORTHEASTWARD OVERNIGHT. MEANWHILE LIGHT RAIN
WILL CONTINUE ACROSS THE WESTERN CWA IN THE DEFORMATION AREA OF
THE UPPER LEVEL WAVE. FORECAST MODELS SHOW THE POTENTIAL FOR SOME
CONVECTION REDEVELOPING IN THE WARM SECTOR OF THE SURFACE LOW
ACROSS EASTERN MN AND WESTERN WI...SO TRIED TO REFLECT THAT IN THE
AFTERNOON POP GRIDS. THESE STORMS DO HAVE THE POTENTIAL TO BE
SEVERE.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 355 PM CDT SUN MAY 11 2014
NOT MUCH IN THE WAY OF CHANGE TO THE EXTENDED PORTION OF THE
FORECAST...WITH THE UPCOMING WEEK BEING MARKED BY COOL
TEMPERATURES AND PERIODIC SCATTERED LIGHT SHOWERS AS A DEEPLY
AMPLIFIED LONGWAVE TROUGH PIVOTS ACROSS THE UPPER MIDWEST AND
GREAT LAKES REGIONS.
THE BEGINNING OF THE LONG TERM PERIOD /MONDAY NIGHT/ WILL FEATURE
RAIN SHOWERS WINDING DOWN AS THE LOW LIFTS TO LAKE SUPERIOR.
ADDITIONAL RAINFALL AMOUNTS SHOULD BE AROUND A COUPLE TENTHS OF AN
INCH OR LESS.
TUESDAY THROUGH FRIDAY BRINGS CYCLONIC FLOW WITH COOLER THAN
NORMAL TEMPERATURES AND THE POTENTIAL FOR OCCASIONAL SCATTERED
SHOWERS AS THE TROUGH BLANKETS THE REGION. HIGHS WILL BE IN THE
50S AND LOWS WILL DIP INTO THE LOWER 30S AND 40S. THE POTENTIAL
FOR FROST LOOKS TO BE TUESDAY THROUGH THURSDAY NIGHTS.
TEMPERATURES MODERATE NEXT WEEKEND AS WESTERN UPPER RIDGING BUILDS
INTO THE CENTRAL CONUS. HIGHS IN THE 60S LOOK LIKE A GOOD BET FOR
NEXT WEEKEND...ALTHOUGH A FEW SHOWERS MAY BE LURKING ON SUNDAY IF
THE ECMWF SOLUTION VERIFIES /WHICH INDICATES A TROUGH WILL BUST
IN FROM THE PACIFIC NORTHWEST AND BREAK DOWN THE RIDGE/.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 725 PM CDT SUN MAY 11 2014
NWD MOVG WMFNT WILL SPREAD SHWRS/TSTMS ACRS THE REGION THRU THE
REST OF THE EVENING INTO THE OVERNIGHT HRS. THIS PRESENTS THE
FIRST ISSUE OF THE 12/00Z TAFS - TIMING OF TSRA. INITIAL RADAR
TRENDS FOLLOW LOCAL MODEL INITIALIZATIONS SO EXTRAPOLATING THAT
BRINGS CONVECTION INTO ALL SITES EXCEPT KAXN AS THE WMFNT LOOKS TO
HOLD OFF PUSHING INTO WRN MN...SO THE REMAINDER OF THE TAF SITES
DO HAVE A BRIEF WINDOW DURING WHICH IFR CONDS DUE TO TSTMS LOOKS
TO OCCUR...MAINLY UP THRU 07Z IN MN AND IN THE 04Z-10Z TIMEFRAME
IN WI. THOUGH THE REDUCTION IN VSBY WILL BE DUE TO PRECIP
INTENSITY...THERE IS A GOOD LIKELIHOOD OF FLIGHT COND REDUCTION
DUE TO LOW STRATUS...WHICH IS THE NEXT ISSUE. AFTER THE PRECIP
ENDS LATE THIS EVENING INTO THE OVERNIGHT...WINDS WILL DROP OFF TO
ARND 5 KT OR SLIGHTLY LESS WITH VRBL DIRECTION...AND WITH PLENTY
OF LOW LEVEL MOISTURE IN PLACE...LOW STRATUS WILL BE AN ISSUE.
WOULD THINK MORE FOG IF WINDS WENT CALM...BUT SFC WINDS LOOK TO
STAY 4-5 KT SO AM THINKING MORE LOW STRATUS WITH LESSER FOG. THE
LAST ISSUE THEN BECOMES TIMING ANOTHER PRECIP WINDOW LATE TMRW
MRNG INTO TMRW AFTN ON THE BACKSIDE OF THE DEPARTING LOW PRES
CENTER...WHEN WINDS WILL SHIFT ARND TO W AND NW. NO CONVECTION
XPCTD AT THAT TIME...BUT LOW STRATUS WILL CONTINUE THRU TMRW.
KMSP...VFR TO START AND INTO THE FIRST COUPLE HRS OF THE TAF THEN
CONDITIONS DETERIORATE LATER THIS EVENING AS SHWRS/TSTMS IMPACT
THE TERMINAL. MAINLY VFR BUT OCNL TSTMS MOVG ACRS THE AREA MAY
WELL DROP VSBY INTO IFR ALONG WITH CIGS SUB-1700 FT. ONCE THE
PRECIP ENDS AND WINDS DROP OFF SLIGHTLY...LOW STRATUS WILL BECOME
AN ISSUE...LEAVING CEILINGS BELOW 1700 FT...AND POSSIBLY UNDER
1000 FT...FOR MUCH THE MORNING PUSH INTO MIDDAY MON. CONDS IMPROVE
SLIGHTLY TMRW AFTN WHEN ANOTHER BATCH OF -RA IS XPCTD BUT CIGS ARE
STILL LIKELY TO REMAIN BELOW 1700 FT THRU TMRW EVE. WINDS SHIFT TO
WLY TMRW AFTN AND INCRS TO ARND 10 KT.
/OUTLOOK FOR KMSP/
TUE...MVFR POSSIBLE. SLGT CHC -SHRA. WINDS W-NW 15-20 KTS.
WED...MVFR POSSIBLE. SLGT CHC -SHRA. WINDS W-NW 5-15 KTS.
THU...MVFR POSSIBLE. SLGT CHC -SHRA. WINDS NW 5-15 KTS.
&&
.HYDROLOGY...
ISSUED AT 355 PM CDT SUN MAY 11 2014
AT THIS TIME RIVER FLOODING APPEARS TO BE THE PRIMARY CONCERN
MAINLY IN WESTERN WI AND THE MAINSTEM OF THE MISSISSIPPI RIVER.
ANOTHER ROUND OF 1 TO 2 INCHES OF BASIN-WIDE RAINFALL IS EXPECTED
OVER THE NEXT 24 HRS. AT THIS TIME...THE THREAT FOR THE HEAVIEST
RAIN AND FLASH FLOODING APPEARS TO BE ACROSS IOWA...SO NOT
ANTICIPATING ANY FLASH FLOODING IN MN OR WI. IF IT WERE TO
HAPPEN...IT WOULD BE IN FAR SOUTHERN MN. LASTLY, IF THE FORECAST
RAINFALL AMOUNTS TREND HIGHER THAN CURRENTLY EXPECTED...THE
FLOODING POTENTIAL WILL INCREASE AS WELL.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
UPDATE...JPC
SHORT TERM...JRB
LONG TERM...LS
AVIATION...JPC
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
234 PM CDT SAT MAY 10 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 235 PM CDT SAT MAY 10 2014
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ARE EXPECTED TO MOVE
ACROSS THE FORECAST AREA THROUGH MIDNIGHT. THE THREAT FOR SEVERE
WEATHER IS LOW...AND THE BEST CHANCE FOR HAIL AND WIND EXISTS ACROSS
WEST CENTRAL AND SOUTHWEST MINNESOTA.
WEAK SURFACE LOW NEARLY CO-LOCATED WITH NICE SHORTWAVE DIGGING IN
ACROSS SOUTH DAKOTA THIS AFTERNOON. THE COMBINATION OF SURFACE
HEATING...WEAK MOISTURE TRANSPORT AND LIFT IS PROMOTING CONVECTIVE
INITIATION ACROSS SOUTHWEST MINNESOTA AND NORTHERN IOWA. THE CURRENT
SHOWERS EXTEND ALONG A NW-SE AXIS OF HIGHER PWATS /0.70"-0.90"/ PER
THE 19Z SURFACE RAP ANALYSIS. THE SBCAPE IS WEAK BUT THE APPROACH
SHORTWAVE IS HELPING TO STEEPEN THE MID LEVEL LAPSE RATE TO
7-7.5C/KM IN WESTERN MINNESOTA. THE UPPER FLOW IS PRETTY WEAK BUT
THERE SHOULD BE ENOUGH FORCING AND SHEAR TO PROMOTE MULTI-CELL
CONVECTIVE MODE AND A SLIGHT CHANCE FOR HAIL AND GUSTY WINDS WITH
THE STRONGEST UPDRAFTS. THIS IS ESPECIALLY TRUE FROM 4-7PM WHERE
THE SFC-6KM MAX LAYER THETA-E DIFFERENCE IS BETWEEN -15C AND -20C
IN WESTERN MN. FARTHER EAST IN EASTERN MN AND WESTERN WI...THE
CONVECTIVE POTENTIAL IS LOWER /ALTHOUGH THERE SHOULD STILL BE A
HEALTHY BAND OF SHOWERS WITH GOOD VERTICAL EXTENT AND IN-CLOUD
LIGHTNING/. MANY OF THE HI-RES WRF SIMULATIONS
/SPC...HOPWRF...NCEP/ HAVE THE RAIN CLEARING MN BY ABOUT 9PM AND
WESTERN WI BY ABOUT MIDNIGHT. THERE WILL BE A BREAK IN THE PRECIP
BEFORE ISENTROPIC LIFT WITH THE STRENGTHENING SOUTHERN PLAINS LOW
STARTS TO SPREAD SHOWERS AND STORMS INTO SOUTHERN MINNESOTA BY
TOMORROW AFTERNOON.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 235 PM CDT SAT MAY 10 2014
THE LONG TERM PORTION OF THE FORECAST WILL BE ACTIVE FROM THE GET-
GO...WITH A SURFACE TROUGH EXPECTED TO BE NOSING INTO SOUTHERN MN
AT 00Z MONDAY. THUNDERSTORMS /LIKELY SEVERE/ ARE EXPECTED TO BE
ONGOING TO THE SOUTH...WITH THE THREAT FOR STRONG THUNDERSTORMS
SHIFTING NORTH INTO SOUTH CENTRAL/EAST MN AND WEST CENTRAL WI ON
SUNDAY NIGHT AS THE INSTABILITY GRADIENT LIFTS NORTH. PRECIPITABLE
WATER VALUES INCREASE TO AROUND 200 PERCENT OF NORMAL /1.5
INCHES/...SO HEAVY RAIN PRODUCING THUNDERSTORMS ARE CERTAINLY A
POSSIBILITY AS LLVL MOISTURE TRANSPORT ENSUES SUNDAY NIGHT AND
MONDAY. COULD STILL POTENTIALLY SEE AMOUNTS CURTAILED A BIT DUE
TO THE CONVECTION TO THE SOUTH...BUT STILL THINK 1-2 INCH TOTALS
ARE QUITE POSSIBLE BETWEEN SUNDAY EVENING AND MONDAY MORNING ALONG
THE INTERSTATE 90 CORRIDOR OF SOUTH CENTRAL AND SOUTHEAST MN...AND
EAST OF INTERSTATE 35 FROM THE TWIN CITIES ACROSS WEST CENTRAL WI.
MONDAY AFTERNOON/EVE WILL BE ANOTHER WINDOW OF TIME WHEN STRONG TO
SEVERE STORMS COULD SKIRT THE SOUTHEASTERN BORDER OF THE FORECAST
AREA...NAMELY ACROSS WEST CENTRAL WI. MONDAY NIGHT AND TUESDAY THE
MID LEVEL TROUGH PIVOTS ACROSS THE AREA AND SUPPLIES ANOTHER ROUND
OF SHOWERS...ALTHOUGH THE THUNDER POTENTIAL WILL HAVE LOWERED
NOTABLY AND COVERAGE SHOULD BE MORE SCATTERED IN NATURE.
MODEL TRENDS FOR WEDNESDAY...PARTICULARLY THE 10.12Z ECMWF WERE TO
KEEP THE NORTHERN AND SOUTHERN STREAM ENERGY A BIT MORE
DISJOINTED...HENCE LEAVING THE LOCAL AREA IN BETWEEN THE MAIN
AREAS OF FORCING. HOWEVER...COULD STILL SEE A FEW INSTABILITY
SHOWERS ON WEDNESDAY THROUGH THE END OF THE WEEK AS THE NORTHERN
STREAM TROUGH SAGS INTO THE UPPER MIDWEST AND GREAT LAKES REGION.
NO SURPRISE THAT TEMPERATURES WILL BE COOL NEXT WEEK...AS H85
TEMPERATURES FLIRT WITH 0 CELSIUS FROM TUESDAY THROUGH FRIDAY.
WILL NEED TO MONITOR THE POTENTIAL FOR FROST DURING THE OVERNIGHT
PERIODS...WITH THE GROWING SEASON NEARING.
BETTER NEWS /IN THE FORM OF WARMER TEMPERATURES/ IS EXPECTED TO
ARRIVE FOR NEXT WEEKEND...AS THE TROUGH LIFTS TO HUDSON BAY AND
WESTERN RIDGING BUILDS TOWARD THE CENTRAL CONUS. EXPECT TO SEE 60S
BACK IN THE FORECAST FOR NEXT SATURDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 148 PM CDT SAT MAY 10 2014
SHOWERS AND THUNDERSTORMS WILL CONTINUE TO EXPAND TO THE NORTHEAST
OVER THE NEXT SEVERAL HOURS. THUNDER CHANCES TODAY ARE DEFINITELY
BETTER AT KAXN/KRWF/KSTC...THAN THE TAF SITES TO THE EAST. VFR
CONDITIONS SHOULD STILL DOMINATE OUTSIDE MVFR CEILINGS AND BRIEF
MVFR/IFR VISIBILITY WITH HEAVIER DOWNPOURS OF RAIN. THE RAIN WILL
CLEAR THIS EVENING.
KMSP...
WE ARE HIGHLY CONFIDENT IN RAIN LATE THIS AFTERNOON AND EARLY
EVENING...BUT THE THREAT FOR THUNDER IS ADMITTEDLY BETTER TO THE
WEST OF THE AIRPORT. WE STILL EXPECT HEALTHY SHOWER WITH AT LEAST
IN CLOUD LIGHTNING OVER KMSP BETWEEN 5-7 PM.
/OUTLOOK FOR KMSP/
SUN...MVFR POSSIBLE. LIKELY -SHRA. WINDS SW TO NW 10-15KTS.
MON...MVFR LIKELY. IFR POSSIBLE. LIKELY -SHRA. WINDS NW 10KTS.
TUE...MVFR POSSIBLE. ISO-SCT -SHRA. WINDS W-NW 15-25KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...CLF
LONG TERM...LS
AVIATION...CLF
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1225 AM CDT SAT MAY 10 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 252 PM CDT FRI MAY 9 2014
MAIN FORECAST CONCERNS WILL BE CHANCE FOR SPRINKLES AND LATE TONIGHT
AND INTO SATURDAY MORNING AND TEMPERATURES THROUGH THE PERIOD.
A WEAK SURFACE HIGH PRESSURE SYSTEM IS DRIFTING THROUGH THE CENTRAL
PLAINS TODAY. THIS HAS KEPT SKIES MOSTLY CLEAR AND WINDS FAIRLY
LIGHT AND VARIABLE.
THE SURFACE HIGH IS EXPECTED TO SLIDE TO THE SOUTHEAST LATE THIS
AFTERNOON AND THIS EVENING. WINDS WILL CONTINUE TO TURN TO THE
SOUTHWEST OR WEST THROUGH THE EVENING HOURS. AN UPPER LEVEL WAVE
WILL MOVE INTO THE AREA TONIGHT. SO FAR THE LOWER LAYERS ARE FAIRLY
DRY...BUT BOTH THE GFS AND NAM BRING IN SOME SPOTTY PRECIPITATION
TONIGHT AND THE HRRR AND WRF ALSO HINT AS SOMETHING VERY SPOTTY
ACROSS THE AREA. WITH THE DRY LOWER LEVELS HAVE KEPT A FEW SPRINKLES
MAINLY IN THE NORTHERN PART OF THE FORECAST AREA BECAUSE CONFIDENCE
IS LOW THERE WOULD BE ANYTHING MEASURABLE. A WEAK COLD FRONT WILL
MOVE INTO THE AREA LATE TONIGHT...MOVING THROUGH THE AREA SATURDAY
MORNING. FOR A FEW HOURS BEHIND THE FRONT THERE WILL BE A LITTLE
BREEZIER CONDITIONS...BUT BEFORE MID AFTERNOON THE WINDS START TO
DIMINISH A LITTLE. EVEN BEHIND THE COLD FRONT THE TEMPERATURES ON
SATURDAY WILL BE FAIRLY WARM.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 252 PM CDT FRI MAY 9 2014
GUIDANCE FROM THE NAM...OPERATIONAL GFS AND EC ALL SUGGEST QUASI-
ZONAL UPPER TROPOSPHERIC FLOW WILL EXIST ACROSS MUCH OF THE CONUS AT
00Z SUNDAY...ALTHOUGH A STRENGTHENING UPPER TROPOSPHERIC SHORT WAVE
OVER THE SOUTHWESTERN CONUS WILL BEGIN TURNING THE FLOW OVER OUR
AREA MORE SOUTHWESTERLY BY 12Z SUNDAY. EVENTUALLY AN UPPER
TROPOSPHERIC LONGWAVE TROUGH AXIS IS EXPECTED TO DEVELOP FROM SOUTH
CENTRAL CANADA INTO THE SOUTHWESTERN CONUS BY 00Z MONDAY...WITH THE
TROUGH AXIS EXPECTED TO MOVE EAST ACROSS ACROSS OUR AREA MONDAY
NIGHT INTO TUESDAY...RESULTING IN NORTHWESTERLY UPPER TROPOSPHERIC
FLOW OVER OUR AREA TUESDAY NIGHT ONWARD. AT THE SURFACE AN AREA OF
LOW BAROMETRIC PRESSURE IS EXPECTED ACROSS WESTERN KANSAS AND
EASTERN COLORADO AT 00Z SUNDAY. THIS SURFACE LOW IS EXPECTED TO MOVE
NORTHEAST...LIKELY NEARING NORTHEAST KANSAS BY 00Z MONDAY AND THE
UPPER MISSISSIPPI VALLEY BY 00Z TUESDAY. SO ALTHOUGH THE LOWER
TROPOSPHERIC FLOW ACROSS OUR AREA WILL START THE LONG TERM FORECAST
PERIOD FROM THE EAST/SOUTHEAST...A TRANSITION TO THE NORTHEAST IS
EXPECTED ACROSS MUCH OF THE AREA DURING THE DAY SUNDAY...AND TO
THE NORTHWEST SUNDAY NIGHT THROUGH MUCH OF THE REST OF THE LONG
TERM FORECAST PERIOD.
THE NAM...OPERATIONAL GFS AND EC ALL SUGGEST A 50-60KT JET STREAK
JUST ABOVE THE BOUNDARY LAYER WILL PROMOTE ENOUGH THERMAL ADVECTION
FOR PRECIPITATION PRODUCTION ACROSS MUCH OF THE CWA SATURDAY NIGHT
...ESPECIALLY ACROSS EASTERN PORTIONS OF THE CWA WHERE THERMAL
ADVECTION...AS WELL AS MOISTURE CONVERGENCE...WILL BE ENHANCED.
GIVEN THIS...WENT AHEAD WITH 20-70% POPS ACROSS MUCH OF THE CWA
SATURDAY NIGHT...WITH THE HIGHEST POPS RELEGATED ACROSS OUR EAST. AT
THIS TIME ANY CONVECTION THAT IS REALIZED SATURDAY NIGHT IS EXPECTED
TO REMAIN WEAK.
ANY OVERNIGHT CONVECTION SHOULD DEPART TO THE EAST/NORTHEAST BY
DAYBREAK SUNDAY AS THE LOWER TROPOSPHERIC JET STREAK ALSO SHIFTS TO
THE EAST. THIS MAY ALLOW FOR A BREAK IN PRECIPITATION AT SOME POINT
SUNDAY MORNING...BUT POPS STILL REMAIN INTACT FOR THE ENTIRE CWA ON
SUNDAY AS THERMAL ADVECTION AHEAD OF THE APPROACHING UPPER
TROPOSPHERIC TROUGH INCREASES. AS THE AFOREMENTIONED SURFACE LOW
MOVES INTO NORTHEASTERN KANSAS SUNDAY AFTERNOON AND EVENING...AN
ASSOCIATED LOWER TROPOSPHERIC BAROCLINIC ZONE IS EXPECTED TO BACK
NORTHWEST AS A WARM FRONT...PERHAPS PUSHING INTO OUR EXTREME
EAST/SOUTHEASTERN CWA. LOWER TROPOSPHERIC CONVERGENCE AND RESULTANT
LIFT ALONG THIS BAROCLINIC ZONE...ALONG WITH INCREASING SYNOPTIC-
SCALE OMEGA DUE TO INCREASING UPPER TROPOSPHERIC THERMAL ADVECTION
AHEAD OF THE APPROACHING TROUGH...APPEARS AS THOUGH THEY WILL BE
SUFFICIENT FOR CONVECTIVE INITIATION SUNDAY AFTERNOON AND EVENING.
SOME OF THIS CONVECTION COULD CERTAINLY BE REALIZED OVER OUR
EAST/SOUTHEAST SUNDAY AFTERNOON AND EVENING. THE BAROCLINIC ZONE
SHOULD QUICKLY DEPART OUR AREA TO THE EAST/SOUTHEAST SUNDAY EVENING
AS THE SURFACE LOW MOVES NORTHEAST...THUS ALLOWING A MUCH COOLER AND
DRIER LOWER TROPOSPHERIC AIR MASS INTO THE AREA. THIS WILL RESULT IN
RAPIDLY DECREASING POTENTIAL INSTABILITY THUS ELIMINATING ANY CHANCE
OF DEEP CONVECTION ACROSS OUR AREA. THAT BEING SAID...CONTINUED
THERMAL ADVECTION AHEAD OF THE APPROACHING TROUGH APPEARS IT WILL
STILL BE SUFFICIENT FOR PRECIPITATION PRODUCTION HEADING INTO THE
REMAINDER OF SUNDAY NIGHT AND EVEN MONDAY. AS A RESULT...POPS REMAIN
INTACT ACROSS MUCH OF THE CWA SUNDAY NIGHT INTO MONDAY. BY MONDAY
NIGHT...UPPER TROPOSPHERIC THERMAL ADVECTION SHOULD DIMINISH AS THE
TROUGH AXIS BEGINS CLEARING THE AREA. DRY CONDITIONS ARE CURRENTLY
FORECAST MONDAY NIGHT THROUGH WEDNESDAY AS A RESULT. WEDNESDAY NIGHT
INTO THURSDAY...THERE ARE INDICATIONS FROM THE OPERATIONAL GFS...AND
TO A LESSER EXTENT THE NAM...OF A WEAK UPPER TROPOSPHERIC
PERTURBATION MOVING ACROSS THE REGION AND PERHAPS PROVIDING A PERIOD
OF LIGHT PRECIPITATION. CONFIDENCE REGARDING THIS FEATURE IS NOT
HIGH...BUT ALLBLEND PRESENTED A ~20% POP TO OUR NORTH/NORTHEAST
WEDNESDAY NIGHT INTO THURSDAY AND OPTED TO KEEP THIS POP AS IS.
GUIDANCE SUGGESTS DEW POINT READINGS WELL INTO THE 60S WILL
INFILTRATE MUCH OF EASTERN KANSAS SUNDAY AFTERNOON ON THE WARM SIDE
OF THE BAROCLINIC ZONE. THE MOISTURE CONTENT OF THE LOWER
TROPOSPHERIC AIR MASS IS NOT EXPECTED TO BE NEARLY AS ROBUST FARTHER
NORTHWEST INTO OUR AREA...BUT AGAIN IF THE BAROCLINIC ZONE CAN SNEAK
INTO OUR EAST/SOUTHEAST SUNDAY AFTERNOON AND EVENING...THEN
POTENTIAL INSTABILITY VALUES COULD CERTAINLY CLIMB INTO THE 1000-
2000J/KG RANGE. DEEP LAYER BULK SHEAR VALUES ON THE ORDER OF ~50KTS
ARE ALSO FORECAST ACROSS OUR EAST/SOUTHEAST SUNDAY AFTERNOON AND
EVENING. SO...ALTHOUGH IT APPEARS THE BULK OF THE SEVERE WEATHER
SHOULD REMAIN SOUTH AND EAST OF OUR CWA...IT STILL APPEARS THERE
WILL BE A BRIEF WINDOW OF OPPORTUNITY FOR STRONG THUNDERSTORM
ACTIVITY ACROSS PORTIONS OF OUR CWA...GENERALLY ALONG AND SOUTHEAST
OF A LINE FROM ALMA TO YORK. A THREAT FOR SEVERE WEATHER WILL RESIDE
FARTHER SOUTHEAST...GENERALLY ALONG AND SOUTHEAST OF A LINE FROM
BELOIT TO HEBRON. WILL GO AHEAD AND MENTION THESE THREATS IN THE HWO
FOR SUNDAY.
GUIDANCE ALSO SUGGESTS LOWER TROPOSPHERIC PRESSURE RISES POST-FROPA
COULD PROVIDE A STRONG LOWER TROPOSPHERIC WIND FIELD ACROSS
NORTHWESTERN PORTIONS OF THE CWA SUNDAY AFTERNOON INTO SUNDAY
EVENING. GUIDANCE SUGGESTS A SUSTAINED WIND OF 25-30KTS WITH LOCALLY
HIGHER GUSTS WILL BE REALIZED AND AS A RESULT...WILL MENTION SUCH
CONDITIONS IN THE HWO.
A COOLER LOWER TROPOSPHERIC AIR MASS WILL INFILTRATE THE AREA
FOLLOWING THE PASSAGE OF THE BAROCLINIC ZONE SUNDAY...WITH HIGHS
GENERALLY IN THE 50 ON MONDAY AND IN THE 60S TUESDAY THROUGH FRIDAY.
OVERNIGHT LOWS IN THE 40S ARE FORECAST FOR THE MOST PART THROUGH THE
LONG TERM FORECAST PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1219 AM CDT SAT MAY 10 2014
VFR CONDITIONS ARE FORECAST THROUGH THE TAF PERIOD. A SURFACE
TROUGH WILL BE WORKING EAST ACROSS THE CENTRAL PLAINS OVERNIGHT
AND EARLY SATURDAY MORNING. WINDS WILL BE LIGHT FROM THE SOUTH
INITIALLY DURING THE TAF PERIOD...HOWEVER ABOVE THE SFC WINDS WILL
BE MUCH STRONGER DUE TO A STRENGTHENING LLVL JET AND INCLUDED A
PERIOD OF LLVL WIND SHEAR. BEHIND THE SURFACE BOUNDARY WINDS WILL
TRANSITION WESTERLY AND NORTHWESTERLY ON SATURDAY. IN DEEP MIXING
WIND GUSTS OVER 20KT ARE POSSIBLE. SFC HIGH PRESSURE WILL BUILD
SOUTHEAST BEHIND THE FRONT AND WINDS WILL DROP OFF AND SWITCH
NORTHEASTERLY TOWARD THE LATTER TAF HOURS. CLOUDS WILL BE LIMITED
TO THE MID/HIGH LEVELS.
&&
.FIRE WEATHER...
ISSUED AT 252 PM CDT FRI MAY 9 2014
RELATIVE HUMIDITY LEVELS ARE EXPECTED TO DROP BELOW 25 PERCENT FOR
NORTH CENTRAL KANSAS AND FAR SOUTHERN SOUTH CENTRAL NEBRASKA FOR
SATURDAY AFTERNOON. DURING THE MORNING THE WINDS WILL BE WEST OR
NORTHWEST AT 15 TO 20 MPH WITH GUSTS TO AROUND 25 MPH...BUT BY
AFTERNOON...WHEN THE RELATIVE HUMIDITY WILL BE THE LOWEST...THE
WINDS WILL HAVE DIMINISHED TO 10 TO 15 MPH WITH GUSTS TO 20 MPH.
EXPECT THERE TO ONLY BE A SMALL TIME FRAME WHERE NEAR CRITICAL FIRE
DANGER IS EVEN CLOSE. WILL LEAVE IT OUT OF THE HWO AT THIS TIME.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...JCB
LONG TERM...BRYANT
AVIATION...FAY
FIRE WEATHER...JCB
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1128 PM EDT SUN MAY 11 2014
.SYNOPSIS...
HIGH PRESSURE OFFSHORE WILL MAINTAIN WELL ABOVE NORMAL TEMPERATURES
THROUGH THE MIDDLE OF THE UPCOMING WEEK. A COLD FRONT WILL
APPROACH THURSDAY BEFORE CROSSING OFFSHORE ON FRIDAY...BRINGING A
GOOD CHANCE FOR SHOWERS AND THUNDERSTORMS. COOLER TEMPERATURES
WILL DEVELOP IN THE WAKE OF THIS COLD FRONT INTO NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF 1045 PM SUNDAY...RIDGING ALOFT AND ITS AXIS NEARLY
OVERHEAD...WILL AMPLIFY-SOME ACROSS THE BI-STATE REGION OVERNIGHT
AND INTO THE SHORT TERM PERIOD. THIS WILL DEFLECT ANY S/W TROFS
ALOFT TO THE WEST AND NORTH OF THE FA. AT THE SFC...MODEST HIGH
PRESSURE CENTERED OFFSHORE AND EAST OF THE CAROLINAS...WILL RIDGE
BACK ACROSS THE REGION...AND PREVAIL GOING INTO THE SHORT TERM
PERIOD. FOR THE REMAINDER OF THIS EVENING AND OVERNIGHT...THE
DIURNALLY INDUCED CONVECTION HAS DISSIPATED LEAVING A FEW OUTFLOW
BOUNDARIES ACROSS PORTIONS OF THE FA GOING INTO DAYLIGHT MONDAY.
WITH THE MAJORITY OF THE LEFTOVER CONVECTIVE CLOUDINESS
DISSIPATING...A SFC BASED INVERSION SHOULD DEVELOP COURTESY OF THE
HOURLY NAMBUFR SOUNDINGS. LOW LEVEL STRATUS BELOW 1K FEET WILL
DEVELOP ACROSS THE FA VIA LATEST HRRR MODEL RUNS. MIN TEMPS HAVE
BEEN MASSAGED UPWARDS ESPECIALLY WITH LOW LEVEL STRATUS OVERTAKING
THE FA AND SFC DEWPOINTS REMAINING WELL INTO THE 60S ACROSS THE
MAJORITY OF THE FA. PATCHY TO AREAS OF FOG WILL ALSO BE ADVERTISED
ACROSS THE FA...FOR MAINLY THE HOURS BETWEEN MIDNIGHT TO JUST AFTER
SUNRISE. COULD BE ONE OF THOSE NIGHTS WHERE LOW LEVEL STRATUS AND FOG
DUEL WITH ONE ANOTHER IN SEEING WHO WILL PREVAIL OVER THE OTHER.
PREVIOUS DISCUSSION............................................
AS OF 300 PM SUNDAY...ISOLATED TO WIDELY SCATTERED SHOWERS ARE
BREAKING OUT ACROSS THE FORECAST AREA EARLY THIS AFTERNOON. SO FAR
HAVE NOTED ONLY ONE BRIEF THUNDERSTORM OVER COASTAL GEORGETOWN
COUNTY. WITH A MODERATELY UNSTABLE ATMOSPHERE AND MOIST LOW LEVELS
EXPECT THIS ACTIVITY TO CONTINUE FOR THE REMAINDER OF THE
AFTERNOON AND INTO THE EARLY EVENING.
BOTH GFS AND NAM INDICATE COLUMN MOISTURE BECOMING MORE SHALLOW
AFTER SUNSET AND WITH AN UPPER RIDGE BUILDING IN SEE LITTLE CHANCE
FOR SIGNIFICANT OVERNIGHT PRECIPITATION. SO...AS THIS ACTIVITY
SEEMS DIURNALLY DRIVEN WITH NO STRONG FORCING MECHANISM
PRESENT...EXPECT CONVECTION TO FADE WITH THE SETTING SUN AND TO BE
OVER WITH BY MIDNIGHT.
HAVE CONTINUED RECENT TREND OF FORECASTING MINIMUM TEMPERATURES A
FEW DEGREES ABOVE GUIDANCE. THIS METHOD HAS BEEN VERIFYING WELL
AGAINST GUIDANCE RECENTLY AND GIVES US OVERNIGHT MINIMUMS IN THE
MID 60S FOR MOST PLACES.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...SUMMERTIME PATTERN AMPLIFIES DURING THE
BEGINNING OF THE WEEK THANKS TO A STRENGTHENING 5H RIDGE. THIS WILL
DRIVE TEMPERATURES WELL INTO THE 80S TO AROUND 90 MONDAY AND TUESDAY
AWAY FROM THE COAST...WITH LOW 80S ANTICIPATED AT THE BEACHES. THESE
VERY WARM TEMPS...COMBINED WITH STILL COOL OCEAN TEMPS...AND A WEAK
GRADIENT BOTH AT THE SURFACE AND ALOFT...SHOULD ALLOW DECENT INLAND
PENETRATION OF THE SEA BREEZE BOTH DAYS. THIS WILL HAVE ONLY LIMITED
IMPACT ON HIGHS THOUGH SINCE TEMPS WILL SOAR QUICKLY DURING LATE
MORNING EARLY AFTN...THANKS TO LOWS ONLY FALLING INTO THE MID/UPR
60S...70 AT THE COAST.
MORE QUESTIONABLE PORTION OF THE FORECAST INVOLVES CONVECTIVE
POTENTIAL THROUGH EARLY WEEK. GUIDANCE IS STUBBORNLY DEPICTING
SCATTERED SHOWERS/TSTMS BOTH MONDAY AND TUESDAY AFTNS...FOCUSED
PRIMARILY ON THE SEA BREEZE. SPC HAS GENERAL RISK ACROSS THE AREA
BOTH DAYS AS WELL. AM STRUGGLING TO FIND REASONS TO INCLUDE
CONVECTION IN THE FORECAST...OTHER THAN DEWPOINTS WELL INTO THE 60S
AND STEEP SURFACE-BASED LAPSE RATES. HOWEVER...PRETTY MUCH
EVERYTHING ELSE POINTS TO THE NEXT TWO DAYS BEING DRY. 500MB RIDGE
AXIS SITS NEARLY OVERHEAD...PROVIDING A SUBSIDENT LID WITH VERY WEAK
MID-LEVEL LAPSE RATES. 700MB RIDGE REMAINS ANCHORED OVERHEAD AS
WELL...FORCING ANY MOISTURE AROUND TO THE WEST OF THE AREA...WHICH
IS ALSO ECHOED BY WEAK 850-700MB MOISTURE TRANSPORT VECTORS AND
DRYING FORECAST SOUNDINGS. LCL`S ARE AT THE TOP OF WHATEVER RESIDUAL
MOIST LAYER EXISTS MONDAY AND TUESDAY...SO UPDRAFTS SHOULD SUFFER
FROM SIGNIFICANT DRY AIR ENTRAINMENT...FURTHER LIMITING CONVECTIVE
POTENTIAL. STILL...INHERITED HAS SCHC MONDAY AND SURROUNDING WFO`S
HAVE AT LEAST THAT...SO WILL KEEP SCHC MONDAY FOR ISOLATED
SHOWERS...BUT DROP POP TO SILENT ON TUESDAY.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 3 PM SUNDAY...THE BIG WEATHER MAKER IN THE LONG TERM WILL BE
AN EASTWARD-MOVING COLD FRONT THURSDAY...PUSHED ALONG BY A FULL
LATITUDE UPPER TROUGH EXTENDING FROM HUDSON BAY TO THE GULF COAST.
THE WESTERN EXTENSION OF THE BERMUDA HIGH WILL COVER THE AREA
WEDNESDAY. RELATIVELY STABLE ONSHORE WINDS AND PLENTY OF DRY AIR
ASSOCIATED WITH THE DEEP-LAYER RIDGING SHOULD KEEP THINGS MOSTLY
SUNNY AND DRY WITH HIGHS IN THE UPPER 80S INLAND AND AROUND 80 ON
THE BEACHES. PRESSURES WILL BEGIN TO FALL WEDNESDAY NIGHT AS THE
AFOREMENTIONED FRONT CROSSES THE LOWER MISSISSIPPI VALLEY.
INCREASING SOUTHERLY FLOW WILL BEGIN TO MOISTEN OUR AIRMASS...AND
PRECIPITABLE WATER VALUES SHOULD CLIMB FROM AROUND 1 INCH WEDNESDAY
TO 1.5 INCHES BY LATE WEDNESDAY NIGHT.
INTEGRATED COLUMN MOISTURE PEAKS JUST AHEAD OF THE FRONT THURSDAY
EVENING WITH PW VALUES NEAR 1.9 INCHES. 850 MB WINDS DO NOT BECOME
PARTICULARLY STRONG...20-30 KT DEPENDING ON YOUR MODEL...AND
KINEMATIC FIELDS ARE NOT OVERLY CONCERNING FOR A SEVERE WEATHER
RISK. GIVEN MODEST FORECAST INSTABILITY (CAPE 1000-1500 J/KG) AND
SUCH MOIST SOUNDINGS THE LARGEST CONCERN COULD BE LOCALLY HEAVY RAIN
AND PERHAPS A WET DOWNBURST IN STRONGER CELLS.
THE BULK OF THE LATEST OPERATIONAL MODEL RUNS SHOW THE COLD FRONT
PUSHING ACROSS THE EASTERN CAROLINAS THURSDAY NIGHT...HOWEVER THE
12Z CANADIAN AS WELL AS ABOUT 25% OF THE 00Z & 06Z GFS ENSEMBLE
MEMBERS ARE SLOWER MOVING THE BOUNDARY OFF THE COAST. I HAVE
THEREFORE MAINTAINED A 30-40 POP INTO FRIDAY. DRY WEATHER SHOULD
ALMOST CERTAINLY DEVELOP BY FRIDAY EVENING LASTING INTO SATURDAY AS
HIGH PRESSURE BUILDS OVER THE CAROLINAS. THE MOST NOTABLE FEATURE
ABOUT THIS INCOMING AIRMASS WILL BE HOW MILD TEMPERATURES WILL BE
COMPARED TO WHAT WE HAVE EXPERIENCED THE PAST WEEK. WITH 850 MB
TEMPS PROGGED +8C TO +10C BOTH FRIDAY AND SATURDAY...HIGHS SHOULD
REMAIN IN THE UPPER 70S FOR MOST AREAS WITH LOWS IN THE 50S.
BY NEXT SUNDAY BOTH THE GFS AND ECMWF SHOW THE TRAILING END OF A
POTENT UPPER LEVEL DISTURBANCE MOVING ACROSS THE CAROLINAS. EVEN
WITH NO LOW-LEVEL GULF OR ATLANTIC INFLOW...MODELS SHOW ENOUGH
PACIFIC MOISTURE COMING ACROSS AT AND ABOVE 850 MB THAT A 30 POP FOR
SHOWERS APPEARS WARRANTED.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
AS OF 00Z...THE RADAR IS QUIET THIS EVENING AS DIURNAL CONVECTION
FROM EARLIER TODAY HAS DISSIPATED. SATELLITE IMAGERY SHOWS MID
LEVEL CLOUDS ARE RAPIDLY DIMINISHING...WHICH ENHANCES THE
POTENTIAL FOR MVFR/IFR FOG OVERNIGHT. WEAK PRESSURE GRADIENT
SHOULD ALLOW WINDS TO BECOME CALM LATER TONIGHT...AND UPPER 60S
DEWPOINTS INDICATE THE LOW LEVEL ENVIRONMENT IS PRIMED FOR FOG.
VSBYS WILL LIKELY DROP FIRST AT KCRE/KMYR GIVEN THEIR SMALL
TEMP/DEWPOINT SPREADS. THESE TERMS COULD SEE IFR VSBYS DEVELOP
BEFORE 06Z. ELSEWHERE...IFR FOG IS EXPECTED TO HOLD OFF UNTIL
AFTER 06Z. GIVEN THE AGREEMENT IN FCST SOUNDINGS AND MAV/MET
GUIDANCE...AT LEAST PERIODS OF IFR VSBYS APPEAR LIKELY AT ALL TAF
SITES OVERNIGHT. THE MID LEVEL MOISTURE THAT HELPED FUEL STORMS
TODAY WILL BE DISPLACED SOUTHWARD TOMORROW. THEREFORE... EXPECT
VFR ON MONDAY WITH SCT AFTN CU AND SOUTH WINDS AOB 10 KTS.
EXTENDED OUTLOOK...EARLY MORNING MVFR/IFR FOG/STRATUS IS POSSIBLE
THROUGH THURSDAY. OTHERWISE VFR CONDITIONS WILL PREVAIL THROUGH
WEDNESDAY. SHOWERS/TSTMS EXPECTED THURSDAY THROUGH EARLY FRIDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1045 PM SUNDAY...ORIENTATION OF THE SFC RIDGE AXIS EXTENDING
ACROSS THE AREA WATERS FROM THE HIGHS CENTER OFFSHORE AND EAST OF
THE CAROLINAS...WILL DETERMINE WIND DIRECTIONS. AT THIS
POINT...MODELS INDICATE WINDS BECOMING SW-WSW NORTH OF LITTLE
RIVER INLET...AND S TO SSW SOUTH OF THIS INLET. THIS TO OCCUR
AFTER THE DEMISE OF THE SEA BREEZE CIRCULATION. THE LOOSE SYNOPTIC
SFC PRESSURE GRADIENT WILL KEEP WIND SPEEDS AT OR BELOW 10 KT.
SIGNIFICANT SEAS WILL RUN 2 TO OCCASIONALLY 3 FT...AND MAINLY BE
COMPRISED OF WIND DRIVEN WAVES WITH PERIODS OF 5 TO 6 SECONDS. AT
THIS POINT...THE 11 TO 13 SECOND PERIOD EASTERLY GROUND SWELL
REMAINS NEGLIGIBLE FOR ANY INPUT INTO THE SIGNIFICANT SEAS.
PREVIOUS DISCUSSION..........................
AS OF 300 PM SUNDAY...MANAGEABLE MARINE CONDITIONS EXPECTED.
EXPECT A LIGHT SW WIND FLOW ACROSS THE WATERS THROUGH TONIGHT.
SEAS GENERALLY 2-3 FEET...IN A MIX OF SSW WAVES 1-2 FEET EVERY 4-5
SEC AND SE WAVES 1-2 FT EVERY 7-8 SECONDS. ISOLATED TSTMS ARE
POSSIBLE NEAR SHORE THIS AFTERNOON INTO THIS EVENING...AND THE
MOTION WILL BE FROM SW TO NE.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...PRIMARILY UNIFORM WIND/WAVE CONDITIONS DURING
THE SHORT TERM AS BERMUDA HIGH PRESSURE SITS OFFSHORE INTO MID-WEEK.
RETURN FLOW AROUND THIS HIGH PRODUCES SW WINDS OF 10-15 KTS DURING
THE DAY...AND 5-10 KTS AT NIGHT. THE EXCEPTION WILL BE IN THE
NEAR-SHORE WATERS WHERE A SEA BREEZE WILL CAUSE WINDS TO GUST UP TO
20 KTS FOR A FEW HOURS EACH AFTN/EVE. THESE WINDS COMBINED WITH THE
LONG FETCH AROUND THE HIGH PRESSURE WILL BUILD SEAS TO 2-3 FT
THROUGH THE PERIOD...WITH A 5 SEC S/SW WIND WAVE AND A 7 SEC SE
GROUND SWELL COMPRISING THE SPECTRUM.
LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 300 PM SUNDAY...HIGH PRESSURE JUST OFFSHORE WEDNESDAY
SHOULD PROVIDE GENTLE ONSHORE WINDS AND DRY WEATHER. MOISTURE WILL
INCREASE THURSDAY AHEAD OF A COLD FRONT...EXPECTED TO MOVE OFF THE
COAST FRIDAY MORNING. THIS FRONT SHOULD BE PRECEDED BY WAVES OF
SHOWERS AND EMBEDDED THUNDERSTORMS...ESPECIALLY LATE THURSDAY
AFTERNOON INTO THURSDAY NIGHT. ONCE THE FRONT MOVES FARTHER
OFFSHORE FRIDAY... CLEARING CONDITIONS ARE EXPECTED ALONG WITH
BREEZY NORTH TO NORTHWEST WINDS. AT THIS TIME IT APPEARS
CONDITIONS SHOULD REMAIN BELOW ADVISORY THRESHOLDS...ALTHOUGH
WINDS BOTH AHEAD OF AND BEHIND THE FRONT COULD APPROACH 20 KNOTS
SOUTHEAST OF CAPE FEAR WHERE SEA SURFACE TEMPERATURES ARE
CURRENTLY HIGHEST.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JDW
NEAR TERM...DCH/REK
SHORT TERM...JDW
LONG TERM...TRA
AVIATION...BJR
AREA FORECAST DISCUSSION
NWS RALEIGH NC
650 AM EDT SAT MAY 10 2014
.SYNOPSIS...AS A COLD FRONT MOVES TOWARD THE REGION FROM THE
NORTHWEST...AN UPPER LEVEL DISTURBANCE MOVES THROUGH THE REGION THIS
AFTERNOON AND EVENING. THE COLD FRONT WEAKENS AS IT APPROACHES THE
CAROLINAS LATE TONIGHT AND EARLY SUNDAY. THE FRONT MOVES BACK NORTH
BY MONDAY AS HIGH PRESSURE BUILDS IN FROM THE EAST.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 310 AM SATURDAY...
THE LATEST SURFACE ANALYSIS SHOWED THE WESTERN END OF HIGH PRESSURE
OVER CENTRAL NORTH CAROLINA WITH A WARM FRONT TO OUR NORTHEAST AND A
COLD FRONT MOVING GRADUALLY SOUTHEAST ACROSS THE GREAT LAKES. FOR
TODAY...AS THE FRONT HEADS TOWARD THE MID-ATLANTIC...BOTH THE NAM
AND THE GFS MOVE A MODEST MID-LEVEL SHORTWAVE THROUGH CENTRAL NORTH
CAROLINA DURING THE AFTERNOON AND EVENING HOURS. ALONG WITH THE MID-
LEVEL WAVE IS AN INCREASE IN MID- AND UPPER-LEVEL WINDS...WITH THE
GFS FORECASTING THE RIGHT ENTRANCE REGION OF A 75KT 300MB JETLET AND
A 55KT 500MB JETLET MOVING ACROSS THE AREA INTO SOUTHERN VIRGINIA
DURING THE AFTERNOON AND EARLY EVENING. UPPER DIVERGENCE ALSO
INCREASES SLIGHTLY WITH THE APPROACH AND PASSAGE OF THE SHORTWAVE
AND JETLETS...WITH MODEST 850MB THETA-E RIDGING IN PLACE THROUGH
ABOUT 18Z.
AFTER ABOUT 18Z...FORECAST CONFIDENCE IN THE DETAILS DECREASES SOME.
MOS GUIDANCE SURFACE DEW POINTS ARE FORECAST TO REMAIN HIGH...IN
GENERAL AROUND 60F...WHILE BOTH THE HRRR AND PARTICULARLY THE RAP
MARKEDLY DIMINISH SURFACE DEW POINTS THIS AFTERNOON...THE LATTER
WELL INTO THE 40S OR BELOW ESPECIALLY OVER THE SOUTHEAST PART OF
CENTRAL NORTH CAROLINA. WHILE THIS MAY BE OVERDONE...THE GFS DOES
SHOW A LARGE DECREASE IN 850MB THETA-E VALUES THIS AFTERNOON...SUCH
THAT THERE IS AN 850MB THETA-E MINIMUM BISECTING CENTRAL NORTH
CAROLINA BY 00Z. LAPSE RATES STEEPEN ESPECIALLY BETWEEN 850MB AND
500MB THIS AFTERNOON...BUT THE GFS ONLY FORECASTS SUCH LAPSE RATES
TO ABOUT WHAT THEY WERE SATURDAY WHILE THE NAM IS NOTICEABLY MORE
UNSTABLE. CONVECTIVE-ALLOWING MODELS SUGGEST THE BEST CHANCES FOR
PRECIPITATION THIS AFTERNOON IS IN THE REGIME OF BETTER 850MB
CONVERGENCE AND UPPER-LEVEL DIVERGENCE OVER THE WESTERN PIEDMONT
ABOUT THE TIME OF INITIAL SHORTWAVE AND JETLET APPROACH...WITH
LESSER CHANCES PARTICULARLY FROM U.S. 1 AND EAST. THIS FORECAST WILL
GRADUATE POPS SIMILARLY...HIGH CHANCE OVER THE WESTERN PIEDMONT AND
SLIGHT CHANCE TO LOW CHANCE ALONG AND EAST OF U.S. 1.
IN TERMS OF THE POTENTIAL FOR SEVERE WEATHER...850MB WINDS DO
INCREASE THIS AFTERNOON TO NEAR 40KT...AND IF THE LOW-LEVELS DO MIX
MORE THAN EXPECTED...THEN AN ISOLATED NEAR-SEVERE OR SEVERE GUST IS
POSSIBLE IN THE STRONGEST ECHOES. ON SATURDAY...EVEN MODEST SHOWERS
WERE APPARENTLY RESULTING IN SOME WIND GUSTS NEAR 40 MPH. IN THE HWO
WILL LIKELY MENTION THE POTENTIAL FOR A STRONG STORM WITH A WIND
GUST TO 50 MPH AS THE BEST TEMPERATURE RISE AND INSTABILITY SHOULD
LIE FARTHER EAST WHERE THE CHANCES FOR DEEP CONVECTION IS LESS.
OVERNIGHT...THE SURFACE FRONT WEAKENS AS IT APPROACHES FROM THE
NORTH. PRECIPITABLE WATER VALUES DIMINISH LATE...AND WILL HOLD ONTO
THE POTENTIAL FOR A SLIGHT CHANCE OR AN ISOLATED SHOWER UNTIL LATE
AT NIGHT...AHEAD OF THE FRONT. HIGHS TODAY...LOWER 80S FAR NORTHWEST
TO UPPER 80S FAR SOUTHEAST...WITH WIND GUSTS AROUND 25 MPH AT TIMES
FROM LATE MORNING THROUGH THE AFTERNOON...POSSIBLY TO AROUND 30 MPH
DESPITE THE CLOUDS TOWARD THE TRIAD. OVERNIGHT LOWS AROUND 60 IN THE
NORTHWEST PIEDMONT TO THE MID 60S TOWARD KFAY AND KCTZ.
&&
.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
AS OF 310 AM SATURDAY...
A WEAK SURFACE FRONT MAY BE OVER OR NEAR THE AREA...BUT THIS
BOUNDARY SHOULD HAVE LIMITED LOW-LEVEL CONVERGENCE ASSOCIATED WITH
IT. BUFR SOUNDINGS FROM BOTH THE NAM AND THE GFS APPEAR CAPPED TO
DEEP CONVECTION...AND WHILE THE GFS DOES SHOW A FEW HUNDREDTHS INCH
OF PRECIPITATION MAINLY OVER THE COASTAL PLAIN SUNDAY AFTERNOON NEAR
THE WEAK SURFACE BOUNDARY...MID-LEVEL FEATURES CURRENTLY SEEM TO
STAY SOUTH OF THE AREA AND SHEAR IS VERY WEAK. IF A SHOWER DOES
OCCUR...CURRENTLY IT IS ANTICIPATED TO BE HIGHLY ISOLATED.
PRECIPITABLE WATER VALUES OVERALL ARE ONLY NEAR AN INCH TOWARD THE
VIRGINIA BORDER AND THE NORTHWEST PIEDMONT...TO NEAR 1.25 INCHES
TOWARD THE SANDHILLS AND SOUTHERN COASTAL PLAIN...STILL LESS THAN
VALUES EXPECTED THIS AFTERNOON. WILL SHOW A DRY FORECAST SUNDAY AND
SUNDAY NIGHT WITH DIMINISHING CLOUDS IN THE MORNING ESPECIALLY
SOUTHEAST OF THE TRIANGLE...PARTLY TO MOSTLY SUNNY ELSEWHERE. HIGHS
IN THE MID TO UPPER 80S WITH OVERNIGHT LOWS IN THE LOWER TO MID 60S.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 310 AM SATURDAY...
MONDAY THROUGH TUESDAY NIGHT: RIDGING ALOFT AND A BERMUDA HIGH OFF
THE COAST WILL DOMINATE THIS PERIOD...RESULTING IN WARM MOIST RETURN
FLOW INTO THE AREA. THE INCREASING TEMPS AND MOISTURE WILL RESULT IN
MARGINAL INSTABILITY...AND WITH WEAK SHEAR OVER THE AREA...THERE
WILL CONTINUE TO BE THE CHANCE FOR DIURNAL SHOWERS AND STORMS TO
DEVELOP...ALTHOUGH THE CHANCE OF SEVERE STORMS CONTINUES TO BE LOW
AT THIS TIME. OTHERWISE...EXPECT MAINLY DRY CONDITIONS. HIGHS IN THE
MID 80S TO AROUND 90 DEGREES AND LOWS IN THE MID 60S.
WEDNESDAY THROUGH FRIDAY: THERE CONTINUES TO BE A LOT OF UNCERTAINTY
FOR THIS PART OF THE FORECAST...AS THE GFS (FASTER) AND ECMWF
(SLOWER) CONTINUE TO DIFFER IN TIMING BY APPROX 24 HOURS OR SO...
BOTH HAVING SLOWED DOWN SOME OVER THE LAST COUPLE OF MODEL RUNS.
WILL CONTINUE TO LEAN MORE TOWARD THE SLOWER ECMWF PROGRESSION OF
THIS SYSTEM...WITH CONFIDENCE REMAINING LOW. REGARDLESS...EXPECT
INCREASING CHANCES OF SHOWERS AND STORMS THROUGH THE PERIOD...WITH
THE BEST CHANCES FOR RAIN AND STRONGEST STORMS BEING THURSDAY
AFT/EVE. THE SHEAR AND INSTABILITY WILL BE BEST ALONG THE FRONT...
AND WITH THE BETTER FORCING DURING THIS TIME...MAY MAKE MENTION OF
SOME POSSIBLE STRONG STORMS MID TO LATE WEEK IN THE HWO. WILL BE
CLOSELY MONITORING THE EVOLUTION OF THIS SYSTEM AS IT APPROACHES IN
HOPES OF NARROWING DOWN TIMING AND INTENSITY...AND HOPEFULLY
INCREASING CONFIDENCE. EXPECT PRECIP CHANCES AND TEMPERATURES TO
DECREASE BEHIND THE FRONT. THOUGH THEY WILL DEPEND ON THE TIMING OF
THE FRONT AND THUS ARE LIKELY TO CHANGE OVER THE NEXT SEVERAL
DAYS...GENERALLY EXPECT TEMPERATURES TO DECREASE DURING THIS PERIOD.
FOR NOW EXPECT HIGHS GENERALLY IN THE MID TO UPPER 80S WEDNESDAY...
DECREASING INTO THE MID TO UPPER 70S BY FRIDAY. LOWS IN THE MID 60S
WEDNESDAY NIGHT...DECREASING INTO THE LOW TO MID 50S BY THE END OF
THE WEEK.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 650 AM SATURDAY...
VFR CONDITIONS ARE EXPECTED TO PREVAIL DURING THE 12Z VALID TAF
PERIOD OUTSIDE OF ANY SHOWER OR THUNDERSTORM...AND A FEW AREAS OF
EARLY MORNING LOW CLOUDS TOWARD KFAY AS NOTED BY THE SURFACE
OBSERVATIONS AROUND 11Z. OUTSIDE OF A VERY ISOLATED SHOWER THIS
MORNING THROUGHOUT CENTRAL NORTH CAROLINA...THE BETTER CHANCE OF A
SHOWER OR THUNDERSTORM THIS AFTERNOON APPEARS TO BE ALONG AND WEST
OF U.S. 1...OR AT THE KRDU AND PARTICULARLY THE TRIAD TAF SITES. THE
LOW-LEVEL WIND FIELD INCREASES SUCH THAT ANY SHOWER OR THUNDERSTORM
COULD PRODUCE A GUSTY WIND...AND HAVE MENTIONED THIS POSSIBILITY...
FOR NOW TO 35KT...AT THE KINT AND KGSO TAF SITES. ANY SHOWERS THIS
EVENING SHOULD BECOME ISOLATED AND WINDS WILL DIMINISH FROM THE
SOUTH TO SOUTHWEST.
BEYOND THE 12Z VALID TAF PERIOD...VFR CONDITIONS SHOULD BE THE RULE
FOR THE REST OF THE WEEKEND. THR PROBABILITY OF LATE NIGHT AND EARLY
MORNING LOW CLOUDS GRADUALLY INCREASES...CURRENTLY FIRST TOWARD THE
TRIAD BY TUESDAY...AND THEN ACROSS CENTRAL NORTH CAROLINA BY
WEDNESDAY. THE CHANCES FOR SHOWERS AND THUNDERSTORMS AND THEIR
ASSOCIATED SUB-VFR CONDITIONS INCREASE AGAIN OVER CENTRAL NORTH
CAROLINA BY WEDNESDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...DJF
SHORT TERM...DJF
LONG TERM...KCP
AVIATION...DJF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
310 AM EDT SAT MAY 10 2014
.SYNOPSIS...AS A COLD FRONT MOVES TOWARD THE REGION FROM THE
NORTHWEST...AN UPPER LEVEL DISTURBANCE MOVES THROUGH THE REGION THIS
AFTERNOON AND EVENING. THE COLD FRONT WEAKENS AS IT APPROACHES THE
CAROLINAS LATE TONIGHT AND EARLY SUNDAY. THE FRONT MOVES BACK NORTH
BY MONDAY AS HIGH PRESSURE BUILDS IN FROM THE EAST.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 310 AM SATURDAY...
THE LATEST SURFACE ANALYSIS SHOWED THE WESTERN END OF HIGH PRESSURE
OVER CENTRAL NORTH CAROLINA WITH A WARM FRONT TO OUR NORTHEAST AND A
COLD FRONT MOVING GRADUALLY SOUTHEAST ACROSS THE GREAT LAKES. FOR
TODAY...AS THE FRONT HEADS TOWARD THE MID-ATLANTIC...BOTH THE NAM
AND THE GFS MOVE A MODEST MID-LEVEL SHORTWAVE THROUGH CENTRAL NORTH
CAROLINA DURING THE AFTERNOON AND EVENING HOURS. ALONG WITH THE MID-
LEVEL WAVE IS AN INCREASE IN MID- AND UPPER-LEVEL WINDS...WITH THE
GFS FORECASTING THE RIGHT ENTRANCE REGION OF A 75KT 300MB JETLET AND
A 55KT 500MB JETLET MOVING ACROSS THE AREA INTO SOUTHERN VIRGINIA
DURING THE AFTERNOON AND EARLY EVENING. UPPER DIVERGENCE ALSO
INCREASES SLIGHTLY WITH THE APPROACH AND PASSAGE OF THE SHORTWAVE
AND JETLETS...WITH MODEST 850MB THETA-E RIDGING IN PLACE THROUGH
ABOUT 18Z.
AFTER ABOUT 18Z...FORECAST CONFIDENCE IN THE DETAILS DECREASES SOME.
MOS GUIDANCE SURFACE DEW POINTS ARE FORECAST TO REMAIN HIGH...IN
GENERAL AROUND 60F...WHILE BOTH THE HRRR AND PARTICULARLY THE RAP
MARKEDLY DIMINISH SURFACE DEW POINTS THIS AFTERNOON...THE LATTER
WELL INTO THE 40S OR BELOW ESPECIALLY OVER THE SOUTHEAST PART OF
CENTRAL NORTH CAROLINA. WHILE THIS MAY BE OVERDONE...THE GFS DOES
SHOW A LARGE DECREASE IN 850MB THETA-E VALUES THIS AFTERNOON...SUCH
THAT THERE IS AN 850MB THETA-E MINIMUM BISECTING CENTRAL NORTH
CAROLINA BY 00Z. LAPSE RATES STEEPEN ESPECIALLY BETWEEN 850MB AND
500MB THIS AFTERNOON...BUT THE GFS ONLY FORECASTS SUCH LAPSE RATES
TO ABOUT WHAT THEY WERE SATURDAY WHILE THE NAM IS NOTICEABLY MORE
UNSTABLE. CONVECTIVE-ALLOWING MODELS SUGGEST THE BEST CHANCES FOR
PRECIPITATION THIS AFTERNOON IS IN THE REGIME OF BETTER 850MB
CONVERGENCE AND UPPER-LEVEL DIVERGENCE OVER THE WESTERN PIEDMONT
ABOUT THE TIME OF INITIAL SHORTWAVE AND JETLET APPROACH...WITH
LESSER CHANCES PARTICULARLY FROM U.S. 1 AND EAST. THIS FORECAST WILL
GRADUATE POPS SIMILARLY...HIGH CHANCE OVER THE WESTERN PIEDMONT AND
SLIGHT CHANCE TO LOW CHANCE ALONG AND EAST OF U.S. 1.
IN TERMS OF THE POTENTIAL FOR SEVERE WEATHER...850MB WINDS DO
INCREASE THIS AFTERNOON TO NEAR 40KT...AND IF THE LOW-LEVELS DO MIX
MORE THAN EXPECTED...THEN AN ISOLATED NEAR-SEVERE OR SEVERE GUST IS
POSSIBLE IN THE STRONGEST ECHOES. ON SATURDAY...EVEN MODEST SHOWERS
WERE APPARENTLY RESULTING IN SOME WIND GUSTS NEAR 40 MPH. IN THE HWO
WILL LIKELY MENTION THE POTENTIAL FOR A STRONG STORM WITH A WIND
GUST TO 50 MPH AS THE BEST TEMPERATURE RISE AND INSTABILITY SHOULD
LIE FARTHER EAST WHERE THE CHANCES FOR DEEP CONVECTION IS LESS.
OVERNIGHT...THE SURFACE FRONT WEAKENS AS IT APPROACHES FROM THE
NORTH. PRECIPITABLE WATER VALUES DIMINISH LATE...AND WILL HOLD ONTO
THE POTENTIAL FOR A SLIGHT CHANCE OR AN ISOLATED SHOWER UNTIL LATE
AT NIGHT...AHEAD OF THE FRONT. HIGHS TODAY...LOWER 80S FAR NORTHWEST
TO UPPER 80S FAR SOUTHEAST...WITH WIND GUSTS AROUND 25 MPH AT TIMES
FROM LATE MORNING THROUGH THE AFTERNOON...POSSIBLY TO AROUND 30 MPH
DESPITE THE CLOUDS TOWARD THE TRIAD. OVERNIGHT LOWS AROUND 60 IN THE
NORTHWEST PIEDMONT TO THE MID 60S TOWARD KFAY AND KCTZ.
&&
.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
AS OF 310 AM SATURDAY...
A WEAK SURFACE FRONT MAY BE OVER OR NEAR THE AREA...BUT THIS
BOUNDARY SHOULD HAVE LIMITED LOW-LEVEL CONVERGENCE ASSOCIATED WITH
IT. BUFR SOUNDINGS FROM BOTH THE NAM AND THE GFS APPEAR CAPPED TO
DEEP CONVECTION...AND WHILE THE GFS DOES SHOW A FEW HUNDREDTHS INCH
OF PRECIPITATION MAINLY OVER THE COASTAL PLAIN SUNDAY AFTERNOON NEAR
THE WEAK SURFACE BOUNDARY...MID-LEVEL FEATURES CURRENTLY SEEM TO
STAY SOUTH OF THE AREA AND SHEAR IS VERY WEAK. IF A SHOWER DOES
OCCUR...CURRENTLY IT IS ANTICIPATED TO BE HIGHLY ISOLATED.
PRECIPITABLE WATER VALUES OVERALL ARE ONLY NEAR AN INCH TOWARD THE
VIRGINIA BORDER AND THE NORTHWEST PIEDMONT...TO NEAR 1.25 INCHES
TOWARD THE SANDHILLS AND SOUTHERN COASTAL PLAIN...STILL LESS THAN
VALUES EXPECTED THIS AFTERNOON. WILL SHOW A DRY FORECAST SUNDAY AND
SUNDAY NIGHT WITH DIMINISHING CLOUDS IN THE MORNING ESPECIALLY
SOUTHEAST OF THE TRIANGLE...PARTLY TO MOSTLY SUNNY ELSEWHERE. HIGHS
IN THE MID TO UPPER 80S WITH OVERNIGHT LOWS IN THE LOWER TO MID 60S.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 310 AM SATURDAY...
MONDAY THROUGH TUESDAY NIGHT: RIDGING ALOFT AND A BERMUDA HIGH OFF
THE COAST WILL DOMINATE THIS PERIOD...RESULTING IN WARM MOIST RETURN
FLOW INTO THE AREA. THE INCREASING TEMPS AND MOISTURE WILL RESULT IN
MARGINAL INSTABILITY...AND WITH WEAK SHEAR OVER THE AREA...THERE
WILL CONTINUE TO BE THE CHANCE FOR DIURNAL SHOWERS AND STORMS TO
DEVELOP...ALTHOUGH THE CHANCE OF SEVERE STORMS CONTINUES TO BE LOW
AT THIS TIME. OTHERWISE...EXPECT MAINLY DRY CONDITIONS. HIGHS IN THE
MID 80S TO AROUND 90 DEGREES AND LOWS IN THE MID 60S.
WEDNESDAY THROUGH FRIDAY: THERE CONTINUES TO BE A LOT OF UNCERTAINTY
FOR THIS PART OF THE FORECAST...AS THE GFS (FASTER) AND ECMWF
(SLOWER) CONTINUE TO DIFFER IN TIMING BY APPROX 24 HOURS OR SO...
BOTH HAVING SLOWED DOWN SOME OVER THE LAST COUPLE OF MODEL RUNS.
WILL CONTINUE TO LEAN MORE TOWARD THE SLOWER ECMWF PROGRESSION OF
THIS SYSTEM...WITH CONFIDENCE REMAINING LOW. REGARDLESS...EXPECT
INCREASING CHANCES OF SHOWERS AND STORMS THROUGH THE PERIOD...WITH
THE BEST CHANCES FOR RAIN AND STRONGEST STORMS BEING THURSDAY
AFT/EVE. THE SHEAR AND INSTABILITY WILL BE BEST ALONG THE FRONT...
AND WITH THE BETTER FORCING DURING THIS TIME...MAY MAKE MENTION OF
SOME POSSIBLE STRONG STORMS MID TO LATE WEEK IN THE HWO. WILL BE
CLOSELY MONITORING THE EVOLUTION OF THIS SYSTEM AS IT APPROACHES IN
HOPES OF NARROWING DOWN TIMING AND INTENSITY...AND HOPEFULLY
INCREASING CONFIDENCE. EXPECT PRECIP CHANCES AND TEMPERATURES TO
DECREASE BEHIND THE FRONT. THOUGH THEY WILL DEPEND ON THE TIMING OF
THE FRONT AND THUS ARE LIKELY TO CHANGE OVER THE NEXT SEVERAL
DAYS...GENERALLY EXPECT TEMPERATURES TO DECREASE DURING THIS PERIOD.
FOR NOW EXPECT HIGHS GENERALLY IN THE MID TO UPPER 80S WEDNESDAY...
DECREASING INTO THE MID TO UPPER 70S BY FRIDAY. LOWS IN THE MID 60S
WEDNESDAY NIGHT...DECREASING INTO THE LOW TO MID 50S BY THE END OF
THE WEEK.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 200 AM SATURDAY...
VFR CONDITIONS ARE EXPECTED TO PREVAIL DURING THE 06Z VALID TAF
PERIOD OUTSIDE OF ANY SHOWER OR THUNDERSTORM. OUTSIDE OF AN ISOLATED
SHOWER EARLY THIS MORNING THROUGHOUT CENTRAL NORTH CAROLINA...THE
BETTER CHANCE OF A SHOWER OR THUNDERSTORM FROM LATE MORNING THROUGH
THE AFTERNOON APPEARS TO BE ALONG AND WEST OF U.S. 1...OR AT THE
KRDU AND PARTICULARLY THE TRIAD TAF SITES. THE LOW-LEVEL WIND FIELD
INCREASES SUCH THAT ANY SHOWER OR THUNDERSTORM COULD PRODUCE A GUSTY
WIND...AND HAVE MENTIONED THIS POSSIBILITY...FOR NOW TO 35KT...AT
THE KINT AND KGSO TAF SITES. ANY SHOWERS THIS EVENING SHOULD BE
ISOLATED AND WINDS DIMINISH FROM THE SOUTH TO SOUTHWEST.
BEYOND THE 06Z VALID TAF PERIOD...VFR CONDITIONS SHOULD BE THE RULE
FOR THE REST OF THE WEEKEND. THR PROBABILITY OF LATE NIGHT AND EARLY
MORNING LOW CLOUDS GRADUALLY INCREASES...CURRENTLY FIRST TOWARD THE
TRIAD BY TUESDAY...AND THEN ACROSS CENTRAL NORTH CAROLINA BY
WEDNESDAY. THE CHANCES FOR SHOWERS AND THUNDERSTORMS AND THEIR
ASSOCIATED SUB-VFR CONDITIONS INCREASE AGAIN OVER CENTRAL NORTH
CAROLINA BY WEDNESDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...DJF
SHORT TERM...DJF
LONG TERM...KCP
AVIATION...DJF
AREA FORECAST DISCUSSION
NWS BISMARCK ND
407 PM CDT SAT MAY 10 2014
.UPDATE...
ISSUED AT 350 PM CDT SAT MAY 10 2014
ADDED THIS UPDATE FOR SCATTERED TO ISOLATED THUNDERSTORMS
NORTHWEST REMAINDER OF THIS AFTERNOON.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 233 PM CDT SAT MAY 10 2014
THE MAIN FORECAST ISSUES IN THE SHORT TERM PERIOD ARE PRECIPITATION
TRENDS AND AMOUNTS TONIGHT THROUGH SUNDAY.
IN THE NEAR TERM...SHOWERS ARE MOST WIDESPREAD ACROSS THE JAMES
RIVER VALLEY...THEN STRETCHING WEST ALONG THE I-94 CORRIDOR INTO
THE SOUTHWEST COUNTIES. THE MODEL CONSENSUS...INCLUDING THE HIGH
RESOLUTION HRRR AND WRF...INDICATE THE FOCUS OF THE HEAVIER RAIN
WILL SHIFT INTO THE NORTHWEST AND NORTH CENTRAL COUNTIES LATER
TONIGHT INTO SUNDAY MORNING. LINGERING SHOWERS ARE POSSIBLE ACROSS
THE EAST SUNDAY AFTERNOON. ELEVATED INSTABILITY FAVORS ISOLATED LATE
AFTERNOON/EVENING THUNDERSTORMS MAINLY EAST OF BISMARCK INTO THE
JAMES RIVER VALLEY...BUT NO SEVERE WEATHER IS EXPECTED. FOR
SUNDAY...EXPECT A CHILLY AND RAW DAY...WITH HIGHS IN THE UPPER 40S
TO UPPER 50S...ABOUT 10-15 DEGREES BELOW NORMAL. A NORTHWEST WIND
WILL BE SUSTAINED AT 20 TO 25 MPH AND MAY FLIRT WITH ADVISORY
CRITERIA ACROSS THE FAR SOUTHWEST.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 233 PM CDT SAT MAY 10 2014
AN SEMI-ACTIVE AND COOL WEATHER PATTERN WILL BE THE MAIN STORY
THROUGH THE LONG TERM FORECAST PERIOD.
UPPER LEVEL TROUGH OVER THE ROCKIES WILL MOVE SLOWLY EAST INTO
THE CENTRAL CONUS SUNDAY NIGHT INTO MONDAY...THEN OFF TO OUR EAST
TUESDAY FOLLOWED BY A QUASI-ACTIVE NORTHWEST FLOW PATTERN FOR THE
REST OF THE WORK WEEK.
FOR SUNDAY NIGHT-MONDAY...SUBSIDENCE ACROSS THE WESTERN HALF OF
THE STATE WILL DRY THINGS OUT WITH LINGERING MOISTURE EAST ALONG
THE UPPER TROUGH. WITH THE TROUGH SLOW TO MOVE EAST...DIURNALLY
DRIVEN SHOWERS WILL BE POSSIBLE BOTH MONDAY AND TUESDAY. MAY BE
COLD ENOUGH DURING THE OVERNIGHT/MORNING PERIODS FOR A RAIN/SNOW
MIX SOME LOCATIONS.
NORTHWEST FLOW WED-FRI WITH POSSIBLE EMBEDDED WAVES AND THE UPPER
JET ALOFT CONTINUING THE THREAT FOR PERIODS OF LIGHT PRECIPITATION.
TEMPERATURES COOL (HIGHS 40S/50S AND LOWS 30S) THROUGH MID
WEEK...WITH A MODERATION IN TEMPERATURES TOWARDS NEXT WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 350 PM CDT SAT MAY 10 2014
SURFACE LOW PRESSURE ACROSS SOUTH CENTRAL NORTH DAKOTA WILL LIFT
EAST NORTHEAST THROUGH TODAY. THE LOW WILL SPREAD SHOWERS ACROSS
WESTERN AND NORTHERN NORTH DAKOTA THIS AFTERNOON AND TONIGHT.
HAZARDS TO AVIATION SCATTERED TO ISOLATED THUNDERSTORMS FROM KJMS-
KMOT THROUGH 06Z...AND LOW VFR BECOMING MVFR AFTER 02Z...THEN
LOWERING TO IFR CEILINGS AFTER 06Z.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...WAA
LONG TERM...NH
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
233 PM CDT SAT MAY 10 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 233 PM CDT SAT MAY 10 2014
THE MAIN FORECAST ISSUES IN THE SHORT TERM PERIOD ARE PRECIPITATION
TRENDS AND AMOUNTS TONIGHT THROUGH SUNDAY.
IN THE NEAR TERM...SHOWERS ARE MOST WIDESPREAD ACROSS THE JAMES
RIVER VALLEY...THEN STRETCHING WEST ALONG THE I-94 CORRIDOR INTO
THE SOUTHWEST COUNTIES. THE MODEL CONSENSUS...INCLUDING THE HIGH
RESOLUTION HRRR AND WRF...INDICATE THE FOCUS OF THE HEAVIER RAIN
WILL SHIFT INTO THE NORTHWEST AND NORTH CENTRAL COUNTIES LATER
TONIGHT INTO SUNDAY MORNING. LINGERING SHOWERS ARE POSSIBLE ACROSS
THE EAST SUNDAY AFTERNOON. ELEVATED INSTABILITY FAVORS ISOLATED LATE
AFTERNOON/EVENING THUNDERSTORMS MAINLY EAST OF BISMARCK INTO THE
JAMES RIVER VALLEY...BUT NO SEVERE WEATHER IS EXPECTED. FOR
SUNDAY...EXPECT A CHILLY AND RAW DAY...WITH HIGHS IN THE UPPER 40S
TO UPPER 50S...ABOUT 10-15 DEGREES BELOW NORMAL. A NORTHWEST WIND
WILL BE SUSTAINED AT 20 TO 25 MPH AND MAY FLIRT WITH ADVISORY
CRITERIA ACROSS THE FAR SOUTHWEST.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 233 PM CDT SAT MAY 10 2014
AN SEMI-ACTIVE AND COOL WEATHER PATTERN WILL BE THE MAIN STORY
THROUGH THE LONG TERM FORECAST PERIOD.
UPPER LEVEL TROUGH OVER THE ROCKIES WILL MOVE SLOWLY EAST INTO
THE CENTRAL CONUS SUNDAY NIGHT INTO MONDAY...THEN OFF TO OUR EAST
TUESDAY FOLLOWED BY A QUASI-ACTIVE NORTHWEST FLOW PATTERN FOR THE
REST OF THE WORK WEEK.
FOR SUNDAY NIGHT-MONDAY...SUBSIDENCE ACROSS THE WESTERN HALF OF
THE STATE WILL DRY THINGS OUT WITH LINGERING MOISTURE EAST ALONG
THE UPPER TROUGH. WITH THE TROUGH SLOW TO MOVE EAST...DIURNALLY
DRIVEN SHOWERS WILL BE POSSIBLE BOTH MONDAY AND TUESDAY. MAY BE
COLD ENOUGH DURING THE OVERNIGHT/MORNING PERIODS FOR A RAIN/SNOW
MIX SOME LOCATIONS.
NORTHWEST FLOW WED-FRI WITH POSSIBLE EMBEDDED WAVES AND THE UPPER
JET ALOFT CONTINUING THE THREAT FOR PERIODS OF LIGHT PRECIPITATION.
TEMPERATURES COOL (HIGHS 40S/50S AND LOWS 30S) THROUGH MID
WEEK...WITH A MODERATION IN TEMPERATURES TOWARDS NEXT WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 110 PM CDT SAT MAY 10 2014
CONFIDENCE IS INCREASING ON COVERAGE OF SHOWERS DURING THE
AFTERNOON AND TONIGHT...AS WELL AS MVFR CEILINGS AND VISIBILITIES
IN SHOWERS AND LIGHT FOG. THESE CONDITIONS ARE EXPECTED TO DEVELOP
THIS AFTERNOON AT KDIK/KBIS/KISN...THEN KMOT/KJMS LATER TONIGHT.
PERIODS OF IFR CEILINGS ALSO POSSIBLE. WINDS WILL TRANSITION TO N/NW
TONIGHT FOLLOWING THE PASSAGE OF A SURFACE LOW.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM/AVIATION...RP KINNEY
LONG TERM...NH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
141 PM CDT SAT MAY 10 2014
.UPDATE...
ISSUED AT 110 PM CDT SAT MAY 10 2014
EARLY AFTERNOON UPDATE FOR MORE ADJUSTMENT TO POPS AND TEMPERATURE
TRENDS. THE MAIN CHANGE FOR TEMPS WAS LOWERING THE HIGHS ACROSS
THE SOUTHWEST IN SHOWERS AND CLOUDS. ELEVATED INSTABILITY WILL BE
CONFINED MAINLY TO THE SOUTHEAST...WHERE AN AFTERNOON THUNDERSTORM
IS POSSIBLE.
UPDATE ISSUED AT 947 AM CDT SAT MAY 10 2014
MORNING UPDATE FOR MINOR ADJUSTMENTS TO POPS TODAY. SCATTERED
SHOWERS CONTINUE TO INCREASE IN COVERAGE ACROSS THE SOUTH
CENTRAL...WHILE BROADER RAIN COVERAGE WILL HOLD OFF UNTIL THIS
AFTERNOON IN THE WEST. POINTS SOUTH AND EAST OF BISMARCK ARE
FAVORED FOR ISOLATED THUNDERSTORMS THIS AFTERNOON AND
EVENING...WITH NO SEVERE WEATHER EXPECTED.
UPDATE ISSUED AT 634 AM CDT SAT MAY 10 2014
WATER VAPOR IMAGERY SHOWS A SHORTWAVE PIVOTING NORTH OVER WESTERN
NORTH DAKOTA THIS MORNING. THIS FEATURE HAS GENERATED AN AREA OF
RAIN SHOWERS ROTATING NORTH OVER SOUTHWESTERN NORTH DAKOTA. THE
LATEST HRRR PROGS THIS ACTIVITY TO CONTINUE TO ROTATE NORTH
OVER WESTERN NORTH DAKOTA THROUGH THE DAY...WITH INCREASING
INSTABILITY DEVELOPING OVER THE SOUTHERN JAMES RIVER BASIN THIS
AFTERNOON. THIS INSTABILITY WILL ALLOW FOR SHOWERS AND POSSIBLE
THUNDERSTORMS TO DEVELOP EAST OF HIGHWAY 83 THIS AFTERNOON.
HOWEVER...WEAK DEEP LAYER SHEAR WILL PRECLUDE ANY SEVERE
DEVELOPMENT.
ONLY MADE MINOR MODIFICATIONS TO THE HOURLY SENSIBLE WEATHER GRIDS
BASED ON CURRENT OBS/TRENDS. OTHERWISE...THE CURRENT FORECAST IS
ON TRACK. THE UPDATED PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 354 AM CDT SAT MAY 10 2014
FOCUS IN THE SHORT TERM WILL BE ON THE ONSET OF PRECIPITATION
TONIGHT AND CHANCES FOR THUNDERSTORMS TOMORROW AFTERNOON AND NIGHT.
LATEST RADAR REFLECTIVITIES STILL SHOW PRECIPITATION JUST ACROSS THE
BORDER IN EASTERN MONTANA AND NORTHWEST SOUTH DAKOTA. NEARLY ALL
MODELS BROUGHT RAIN SHOWERS IN TO EARLY TONIGHT AND THUS HAVE
CONTINUOUSLY BACKED OFF POPS IN THE VERY SHORT TERM THROUGH THE
NIGHT. THAT SAID SHOWERS ARE BEGINNING TO FILL IN OVER WESTERN SOUTH
DAKOTA AND THE LATEST MODEL CONSENSUS ON SHOWERS MOVING IN FROM
SOUTH SOUTHWEST TO NORTH NORTHEAST IS GOOD IN THE EARLY MORNING
HOURS THROUGH THE AFTERNOON AND EVENING.
THERE MAY BE AN OPPORTUNITY FOR CONVECTION IN THE SOUTH CENTRAL
NEAR THE SURFACE LOW AND ON THE BACK EDGE OF PRECIPITATION SHIELD
IN THE AFTERNOON INTO THE EVENING. NOT EXPECTING ANY SEVERE STORMS
IN BUT EMBEDDED THUNDER CAN NOT BE RULED OUT YET. BEYOND 00 UTC
SUNDAY EMBEDDED THUNDER MAY PROGRESS AS FAR NORTH AS THE
INTERNATIONAL BORDER WHILE ALSO SLIGHT CHANCES FOR STRAY
THUNDERSTORMS WILL ALSO BE POSSIBLE FURTHER SOUTH IN THE JAMES
RIVER VALLEY.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 354 AM CDT SAT MAY 10 2014
THE MEDIUM RANGE MODELS ARE IN A LITTLE BETTER AGREEMENT WITH
RESPECT TO THE UPPER PATTERN OVER THE CONUS SUNDAY.
HOWEVER...MODEL SOLUTIONS DIVERGE MONDAY THROUGH THE REMAINDER OF
THE PERIOD. THEREFORE...UNCERTAINTY ABOUNDS REGARDING THE FORECAST
DURING THE WORK WEEK.
THE MAIN WEATHER DRIVER WILL BE THE POSITION OF AN UPPER LOW PROGGED
TO AFFECT THE NORTHERN PLAINS SUNDAY-TUESDAY. THE 00Z GFS/ECMWF/GEM
PROG THE LOW TO SET UP OVER SOUTHERN SASKATCHEWAN SUNDAY. THE
WESTERN AND SOUTHERN COUNTIES ARE FORECAST TO GET DRY SLOTTED WITH
SLIGHT CHANCE POPS INDICATED.
BY MONDAY...THE 00Z GFS PROGS THE LOW TO DIP INTO NORTH CENTRAL
NORTH DAKOTA WHEREAS THE 00Z GEM/ECMWF PROG THE LOW TO BECOME AN
OPEN WAVE OVER SOUTHEASTERN SASKATCHEWAN/WESTERN NORTH DAKOTA. THE
00Z GFS DRY SLOTS NORTH DAKOTA WHEREAS THE 00Z ECMWF/GEM PAINT
CHANCE POPS OVER EASTERN NORTH DAKOTA. FOR THE SAKE OF
CONSISTENCY...WILL CONTINUE TO FOLLOW THE ECMWF/GEM SOLUTIONS FOR
THIS PERIOD AND INDICATE CHANCE POPS ALONG AND EAST OF HIGHWAY 83.
BY TUESDAY...THE GEM/GFS/ECMWF PROG THE LOW/OPEN WAVE TO SHIFT EAST
INTO MINNESOTA...WITH NORTHWESTERLY FLOW ALOFT DEVELOPING OVER THE
STATE. THIS SYNOPTIC REGIME IS FORECAST TO CONTINUE THROUGH
WEDNESDAY. EMBEDDED SHORTWAVES IN THE NORTHWESTERLY FLOW ALOFT
SHOULD PROVIDE AT LEAST A SLIGHT CHANCE OF RAIN SHOWERS THROUGH
WEDNESDAY.
BY THURSDAY...SYNOPTIC SUBSIDENCE IS PROGGED TO OVERSPREAD THE STATE
AHEAD OF A SUBTLE PACIFIC RIDGE. THIS SHOULD LEAD TO MAINLY DRY
CONDITIONS WITH HIGHS POSSIBLY IN THE 60S AGAIN BY FRIDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 110 PM CDT SAT MAY 10 2014
CONFIDENCE IS INCREASING ON COVERAGE OF SHOWERS DURING THE
AFTERNOON AND TONIGHT...AS WELL AS MVFR CEILINGS AND VISIBILITIES
IN SHOWERS AND LIGHT FOG. THESE CONDITIONS ARE EXPECTED TO DEVELOP
THIS AFTERNOON AT KDIK/KBIS/KISN...THEN KMOT/KJMS LATER TONIGHT.
PERIODS OF IFR CEILINGS ALSO POSSIBLE. WINDS WILL TRANSITION TO N/NW
TONIGHT FOLLOWING THE PASSAGE OF A SURFACE LOW.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE/AVIATION...RP KINNEY
SHORT TERM...MM
LONG TERM...TM
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1004 AM CDT SAT MAY 10 2014
.UPDATE...
ISSUED AT 947 AM CDT SAT MAY 10 2014
MORNING UPDATE FOR MINOR ADJUSTMENTS TO POPS TODAY. SCATTERED
SHOWERS CONTINUE TO INCREASE IN COVERAGE ACROSS THE SOUTH
CENTRAL...WHILE BROADER RAIN COVERAGE WILL HOLD OFF UNTIL THIS
AFTERNOON IN THE WEST. POINTS SOUTH AND EAST OF BISMARCK ARE
FAVORED FOR ISOLATED THUNDERSTORMS THIS AFTERNOON AND
EVENING...WITH NO SEVERE WEATHER EXPECTED.
UPDATE ISSUED AT 634 AM CDT SAT MAY 10 2014
WATER VAPOR IMAGERY SHOWS A SHORTWAVE PIVOTING NORTH OVER WESTERN
NORTH DAKOTA THIS MORNING. THIS FEATURE HAS GENERATED AN AREA OF
RAIN SHOWERS ROTATING NORTH OVER SOUTHWESTERN NORTH DAKOTA. THE
LATEST HRRR PROGS THIS ACTIVITY TO CONTINUE TO ROTATE NORTH
OVER WESTERN NORTH DAKOTA THROUGH THE DAY...WITH INCREASING
INSTABILITY DEVELOPING OVER THE SOUTHERN JAMES RIVER BASIN THIS
AFTERNOON. THIS INSTABILITY WILL ALLOW FOR SHOWERS AND POSSIBLE
THUNDERSTORMS TO DEVELOP EAST OF HIGHWAY 83 THIS AFTERNOON.
HOWEVER...WEAK DEEP LAYER SHEAR WILL PRECLUDE ANY SEVERE
DEVELOPMENT.
ONLY MADE MINOR MODIFICATIONS TO THE HOURLY SENSIBLE WEATHER GRIDS
BASED ON CURRENT OBS/TRENDS. OTHERWISE...THE CURRENT FORECAST IS
ON TRACK. THE UPDATED PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 354 AM CDT SAT MAY 10 2014
FOCUS IN THE SHORT TERM WILL BE ON THE ONSET OF PRECIPITATION
TONIGHT AND CHANCES FOR THUNDERSTORMS TOMORROW AFTERNOON AND NIGHT.
LATEST RADAR REFLECTIVITIES STILL SHOW PRECIPITATION JUST ACROSS THE
BORDER IN EASTERN MONTANA AND NORTHWEST SOUTH DAKOTA. NEARLY ALL
MODELS BROUGHT RAIN SHOWERS IN TO EARLY TONIGHT AND THUS HAVE
CONTINUOUSLY BACKED OFF POPS IN THE VERY SHORT TERM THROUGH THE
NIGHT. THAT SAID SHOWERS ARE BEGINNING TO FILL IN OVER WESTERN SOUTH
DAKOTA AND THE LATEST MODEL CONSENSUS ON SHOWERS MOVING IN FROM
SOUTH SOUTHWEST TO NORTH NORTHEAST IS GOOD IN THE EARLY MORNING
HOURS THROUGH THE AFTERNOON AND EVENING.
THERE MAY BE AN OPPORTUNITY FOR CONVECTION IN THE SOUTH CENTRAL
NEAR THE SURFACE LOW AND ON THE BACK EDGE OF PRECIPITATION SHIELD
IN THE AFTERNOON INTO THE EVENING. NOT EXPECTING ANY SEVERE STORMS
IN BUT EMBEDDED THUNDER CAN NOT BE RULED OUT YET. BEYOND 00 UTC
SUNDAY EMBEDDED THUNDER MAY PROGRESS AS FAR NORTH AS THE
INTERNATIONAL BORDER WHILE ALSO SLIGHT CHANCES FOR STRAY
THUNDERSTORMS WILL ALSO BE POSSIBLE FURTHER SOUTH IN THE JAMES
RIVER VALLEY.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 354 AM CDT SAT MAY 10 2014
THE MEDIUM RANGE MODELS ARE IN A LITTLE BETTER AGREEMENT WITH
RESPECT TO THE UPPER PATTERN OVER THE CONUS SUNDAY.
HOWEVER...MODEL SOLUTIONS DIVERGE MONDAY THROUGH THE REMAINDER OF
THE PERIOD. THEREFORE...UNCERTAINTY ABOUNDS REGARDING THE FORECAST
DURING THE WORK WEEK.
THE MAIN WEATHER DRIVER WILL BE THE POSITION OF AN UPPER LOW PROGGED
TO AFFECT THE NORTHERN PLAINS SUNDAY-TUESDAY. THE 00Z GFS/ECMWF/GEM
PROG THE LOW TO SET UP OVER SOUTHERN SASKATCHEWAN SUNDAY. THE
WESTERN AND SOUTHERN COUNTIES ARE FORECAST TO GET DRY SLOTTED WITH
SLIGHT CHANCE POPS INDICATED.
BY MONDAY...THE 00Z GFS PROGS THE LOW TO DIP INTO NORTH CENTRAL
NORTH DAKOTA WHEREAS THE 00Z GEM/ECMWF PROG THE LOW TO BECOME AN
OPEN WAVE OVER SOUTHEASTERN SASKATCHEWAN/WESTERN NORTH DAKOTA. THE
00Z GFS DRY SLOTS NORTH DAKOTA WHEREAS THE 00Z ECMWF/GEM PAINT
CHANCE POPS OVER EASTERN NORTH DAKOTA. FOR THE SAKE OF
CONSISTENCY...WILL CONTINUE TO FOLLOW THE ECMWF/GEM SOLUTIONS FOR
THIS PERIOD AND INDICATE CHANCE POPS ALONG AND EAST OF HIGHWAY 83.
BY TUESDAY...THE GEM/GFS/ECMWF PROG THE LOW/OPEN WAVE TO SHIFT EAST
INTO MINNESOTA...WITH NORTHWESTERLY FLOW ALOFT DEVELOPING OVER THE
STATE. THIS SYNOPTIC REGIME IS FORECAST TO CONTINUE THROUGH
WEDNESDAY. EMBEDDED SHORTWAVES IN THE NORTHWESTERLY FLOW ALOFT
SHOULD PROVIDE AT LEAST A SLIGHT CHANCE OF RAIN SHOWERS THROUGH
WEDNESDAY.
BY THURSDAY...SYNOPTIC SUBSIDENCE IS PROGGED TO OVERSPREAD THE STATE
AHEAD OF A SUBTLE PACIFIC RIDGE. THIS SHOULD LEAD TO MAINLY DRY
CONDITIONS WITH HIGHS POSSIBLY IN THE 60S AGAIN BY FRIDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 947 AM CDT SAT MAY 10 2014
EXPECTING MVFR TO LOW VFR CEILINGS IN SHOWERS THIS
AFTERNOON/EVENING AT KDIK/KISN/KBIS/KJMS...AND LATER TONIGHT
AT KMOT. AN ISOLATED AFTERNOON/EVENING THUNDERSTORM IS NOT OUT OF
THE QUESTION AT KJMS. WINDS WILL BECOME NORTHWESTERLY FROM WEST TO EAST
TONIGHT AFTER THE PASSAGE OF A SURFACE LOW/TROUGH.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE/AVIATION...RP KINNEY
SHORT TERM...MM
LONG TERM...TM
AREA FORECAST DISCUSSION
NWS BISMARCK ND
634 AM CDT SAT MAY 10 2014
.UPDATE...
ISSUED AT 634 AM CDT SAT MAY 10 2014
WATER VAPOR IMAGERY SHOWS A SHORTWAVE PIVOTING NORTH OVER WESTERN
NORTH DAKOTA THIS MORNING. THIS FEATURE HAS GENERATED AN AREA OF
RAIN SHOWERS ROTATING NORTH OVER SOUTHWESTERN NORTH DAKOTA. THE
LATEST HRRR PROGS THIS ACTIVITY TO CONTINUE TO ROTATE NORTH
OVER WESTERN NORTH DAKOTA THROUGH THE DAY...WITH INCREASING
INSTABILITY DEVELOPING OVER THE SOUTHERN JAMES RIVER BASIN THIS
AFTERNOON. THIS INSTABILITY WILL ALLOW FOR SHOWERS AND POSSIBLE
THUNDERSTORMS TO DEVELOP EAST OF HIGHWAY 83 THIS AFTERNOON.
HOWEVER...WEAK DEEP LAYER SHEAR WILL PRECLUDE ANY SEVERE
DEVELOPMENT.
ONLY MADE MINOR MODIFICATIONS TO THE HOURLY SENSIBLE WEATHER GRIDS
BASED ON CURRENT OBS/TRENDS. OTHERWISE...THE CURRENT FORECAST IS
ON TRACK. THE UPDATED PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 354 AM CDT SAT MAY 10 2014
FOCUS IN THE SHORT TERM WILL BE ON THE ONSET OF PRECIPITATION
TONIGHT AND CHANCES FOR THUNDERSTORMS TOMORROW AFTERNOON AND NIGHT.
LATEST RADAR REFLECTIVITIES STILL SHOW PRECIPITATION JUST ACROSS THE
BORDER IN EASTERN MONTANA AND NORTHWEST SOUTH DAKOTA. NEARLY ALL
MODELS BROUGHT RAIN SHOWERS IN TO EARLY TONIGHT AND THUS HAVE
CONTINUOUSLY BACKED OFF POPS IN THE VERY SHORT TERM THROUGH THE
NIGHT. THAT SAID SHOWERS ARE BEGINNING TO FILL IN OVER WESTERN SOUTH
DAKOTA AND THE LATEST MODEL CONSENSUS ON SHOWERS MOVING IN FROM
SOUTH SOUTHWEST TO NORTH NORTHEAST IS GOOD IN THE EARLY MORNING
HOURS THROUGH THE AFTERNOON AND EVENING.
THERE MAY BE AN OPPORTUNITY FOR CONVECTION IN THE SOUTH CENTRAL
NEAR THE SURFACE LOW AND ON THE BACK EDGE OF PRECIPITATION SHIELD
IN THE AFTERNOON INTO THE EVENING. NOT EXPECTING ANY SEVERE STORMS
IN BUT EMBEDDED THUNDER CAN NOT BE RULED OUT YET. BEYOND 00 UTC
SUNDAY EMBEDDED THUNDER MAY PROGRESS AS FAR NORTH AS THE
INTERNATIONAL BORDER WHILE ALSO SLIGHT CHANCES FOR STRAY
THUNDERSTORMS WILL ALSO BE POSSIBLE FURTHER SOUTH IN THE JAMES
RIVER VALLEY.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 354 AM CDT SAT MAY 10 2014
THE MEDIUM RANGE MODELS ARE IN A LITTLE BETTER AGREEMENT WITH
RESPECT TO THE UPPER PATTERN OVER THE CONUS SUNDAY.
HOWEVER...MODEL SOLUTIONS DIVERGE MONDAY THROUGH THE REMAINDER OF
THE PERIOD. THEREFORE...UNCERTAINTY ABOUNDS REGARDING THE FORECAST
DURING THE WORK WEEK.
THE MAIN WEATHER DRIVER WILL BE THE POSITION OF AN UPPER LOW PROGGED
TO AFFECT THE NORTHERN PLAINS SUNDAY-TUESDAY. THE 00Z GFS/ECMWF/GEM
PROG THE LOW TO SET UP OVER SOUTHERN SASKATCHEWAN SUNDAY. THE
WESTERN AND SOUTHERN COUNTIES ARE FORECAST TO GET DRY SLOTTED WITH
SLIGHT CHANCE POPS INDICATED.
BY MONDAY...THE 00Z GFS PROGS THE LOW TO DIP INTO NORTH CENTRAL
NORTH DAKOTA WHEREAS THE 00Z GEM/ECMWF PROG THE LOW TO BECOME AN
OPEN WAVE OVER SOUTHEASTERN SASKATCHEWAN/WESTERN NORTH DAKOTA. THE
00Z GFS DRY SLOTS NORTH DAKOTA WHEREAS THE 00Z ECMWF/GEM PAINT
CHANCE POPS OVER EASTERN NORTH DAKOTA. FOR THE SAKE OF
CONSISTENCY...WILL CONTINUE TO FOLLOW THE ECMWF/GEM SOLUTIONS FOR
THIS PERIOD AND INDICATE CHANCE POPS ALONG AND EAST OF HIGHWAY 83.
BY TUESDAY...THE GEM/GFS/ECMWF PROG THE LOW/OPEN WAVE TO SHIFT EAST
INTO MINNESOTA...WITH NORTHWESTERLY FLOW ALOFT DEVELOPING OVER THE
STATE. THIS SYNOPTIC REGIME IS FORECAST TO CONTINUE THROUGH
WEDNESDAY. EMBEDDED SHORTWAVES IN THE NORTHWESTERLY FLOW ALOFT
SHOULD PROVIDE AT LEAST A SLIGHT CHANCE OF RAIN SHOWERS THROUGH
WEDNESDAY.
BY THURSDAY...SYNOPTIC SUBSIDENCE IS PROGGED TO OVERSPREAD THE STATE
AHEAD OF A SUBTLE PACIFIC RIDGE. THIS SHOULD LEAD TO MAINLY DRY
CONDITIONS WITH HIGHS POSSIBLY IN THE 60S AGAIN BY FRIDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 634 AM CDT SAT MAY 10 2014
A FRONTAL BOUNDARY SITS ACROSS EASTERN MONTANA INTO WESTERN SOUTH
DAKOTA. EXPECT RAIN SHOWERS TO MOVE SOUTHWEST TO NORTHEAST ACROSS
NORTH DAKOTA AS THE FRONTAL BOUNDER MOVES EAST ACROSS THE REGION.
MVFR CONDITIONS ARE BEING SEEN IN SOME LOCATIONS RECEIVING RAINFALL
IN EASTERN MONTANA AND WESTERN SOUTH DAKOTA EARLY THIS
MORNING...THUS HAVE GONE AHEAD AND PUT MVFR CONDITIONS IN FOR
KDIK...KISN...KJMS...AND KBIS AT THE TIME RAIN SHOWERS ARE EXPECTED.
AT THIS TIME NOTHING LESS THAN MVFR IS EXPECTED WITH THE RAIN
SHOWERS...HOWEVER CEILINGS MAY DROP TO IFR CATEGORY IN MORE MODERATE
SHOWERS...ESPECIALLY AT SITES KDIK AND KISN.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TM
SHORT TERM...MM
LONG TERM...TM
AVIATION...MM
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1250 AM CDT SAT MAY 10 2014
.UPDATE...
ISSUED AT 1242 AM CDT SAT MAY 10 2014
UPDATE TO POPS ACROSS THE WEST AS SCATTERED SHOWER ACTIVITY
REMAINS OVER EASTERN MONTANA AND FAR NORTHWEST SOUTH DAKOTA.
LATEST HRRR MOVES SHOWERS INTO THE FAR SOUTHWEST AFTER 2
AM.
UPDATE ISSUED AT 940 PM CDT FRI MAY 9 2014
SHOWERS TAKING A SLIGHTLY SLOWER EASTWARD TREND AS THEY BEGIN TO
MOVE TO EASTERN MONTANA THIS EVENING. EXPECT SHOWERS MAINLY AFTER
MIDNIGHT CDT ACROSS THE WEST. NEW NAM BRINGS A CHANCE OF SHOWERS
SOUTH CENTRAL AFTER NOON SATURDAY WITH MOST OF THE PRECIP LIMITED
TO THE NORTHWEST DURING THE DAY ON SATURDAY.
UPDATE ISSUED AT 630 PM CDT FRI MAY 9 2014
SLOW MOVING AREA OF SHOWERS IN EASTERN MONTANA LIKELY WILL BEGIN
TO MOVE INTO FAR WESTERN NORTH DAKOTA THIS EVENING...BUT A BIT
SLOWER. ADJUSTED THIS TO A MORE MID EVENING TIME FRAME...WITH
INITIALLY LOW POPS MOVING IN.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 255 PM CDT FRI MAY 9 2014
THE MAIN FORECAST ISSUE IN THE SHORT TERM PERIOD WILL BE
PRECIPITATION CHANCES TONIGHT AND SATURDAY. ECMWF HAS BEEN THE
MOST CONSISTENT OF THE DETERMINISTIC MODELS AND WILL USE FOR
PRECIPITATION DETAILS.
CURRENTLY...SUNNY SKIES ACROSS WESTERN AND CENTRAL NORTH DAKOTA
WITH INCREASING CLOUDS MOVING FROM CENTRAL INTO EASTERN MONTANA.
TEMPERATURES ARE RANGING FROM THE MID 50S TO LOWER 60S ACROSS THE
STATE.
FOR TONIGHT...MODELS HAVE BEEN TRENDING A LITTLE SLOWER WITH THE
INITIAL PRECIPITATION MOVING INTO WESTERN NORTH DAKOTA TONIGHT AND
HAVE ADJUSTED POPS ACCORDINGLY. IN ADDITION...WITH THE SLOWER
MOVEMENT...LATEST 17 UTC HRRR AND 18 UTC RAP ARE INDICATING BEST
MOISTURE AND INSTABILITY NOT MAKING IT INTO WESTERN NORTH DAKOTA
UNTIL AROUND MIDNIGHT...OR AFTER. BY THIS TIME THINK THE
POSSIBILITY OF CONVECTION WILL BE MINIMAL SO WILL LEAVE OUT THE
MENTION OF THUNDER.
SATURDAY...A SPLIT UPPER LEVEL TROUGH TAKES SHAPE OVER THE WESTERN
U.S. WITH LEAD SHORTWAVE ENERGY FROM THE SOUTHERN WAVE EJECTING
INTO THE DAKOTAS. WITH AN ASSOCIATED SURFACE LOW LIFTING FROM
SOUTH DAKOTA INTO CENTRAL NORTH DAKOTA. PRECIPITATION CHANCES
WILL SPREAD SOUTHWEST TO NORTHEAST ACROSS THE CWA DURING THE DAY.
THERE MAY BE A BRIEF OPPORTUNITY FOR CONVECTION NEAR THE SURFACE
LOW AND ON THE BACK EDGE OF PRECIPITATION SHIELD IN THE SOUTH CENTRAL
SATURDAY AFTERNOON.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 255 PM CDT FRI MAY 9 2014
AN ACTIVE AND COOL WEATHER PATTERN WILL BE THE MAIN STORY THROUGH
THE LONG TERM FORECAST PERIOD.
UPPER LOW/TROUGH OVER THE PACIFIC NORTHWEST DIGS ACROSS THE
WESTERN CONUS INTO SATURDAY...MOVING OVER THE ROCKIES SUNDAY. 12Z
MODELS HAVE COME INTO MUCH BETTER AGREEMENT WITH THE TROUGH
LINGERING ACROSS THE NORTHERN PLAINS INTO TUESDAY...FOLLOWED BY AN
ACTIVE NORTHWEST FLOW PATTERN FOR THE REST OF THE WORK WEEK.
WILL MAINTAIN CHANCES FOR PRECIPITATION THROUGH MUCH OF THE
PERIOD ALONG WITH CONTINUED COOL/BELOW AVERAGE TEMPERATURES.
FOR SATURDAY NIGHT-SUNDAY...EMBEDDED UPPER LEVEL LOW LIFTS SLOWLY
NORTH ACROSS THE DAKOTAS...PUTTING BEST PRECIP CHANCES NORTH AND
WRAP AROUND MOISTURE WEST. MIX OF RAIN/SNOW POSSIBLE WEST SUNDAY
MORNING AS COLDER AIR IS PULLED SOUTH FROM CANADA. SHOWERS
CONTINUE EAST AND NORTH DURING THE DAY SUNDAY ALONG WITH
INCREASING NORTHWESTERLY WINDS FROM WEST TO EAST BEHIND A SFC LOW.
SUBSIDENCE ACROSS THE WESTERN HALF OF THE STATE SUNDAY NIGHT
SHOULD DRY THINGS OUT WITH LINGERING MOISTURE EAST ALONG THE UPPER
TROUGH. WITH THE TROUGH SLOW TO MOVE EAST...DIURNALLY DRIVEN
SHOWERS WILL BE POSSIBLE BOTH MONDAY AND TUESDAY. MAY BE COLD
ENOUGH DURING THE OVERNIGHT/MORNING PERIODS FOR A RAIN/SNOW MIX
SOME LOCATIONS.
NORTHWEST FLOW WED-FRI WITH POSSIBLE EMBEDDED WAVES AND THE UPPER
JET ALOFT CONTINUING THE THREAT FOR PRECIPITATION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1250 AM CDT SAT MAY 10 2014
FRONTAL BOUNDARY SITS JUST WEST OF THE MONTANA DAKOTA BORDER AT 06
UTC TONIGHT. THIS BOUNDARY WILL SLOWLY PROGRESS EAST THROUGH THE
06 UTC TAF CYCLE. RAIN SHOWERS WILL ACCOMPANY THE FRONT FROM WEST
TO EAST. AT THIS TIME VFR CONDITIONS ARE ANTICIPATED AT ALL SITES
EXCEPT KISN...MVFR...STARTING AT 03 UTC. HOWEVER WITH THE SHOWERS
MVFR CONDITIONS COULD BECOME COMMON ACROSS WESTERN AND CENTRAL
NORTH DAKOTA.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...MM
SHORT TERM...TWH
LONG TERM...NH
AVIATION...MM
AREA FORECAST DISCUSSION
NWS TULSA OK
1149 PM CDT FRI MAY 9 2014
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
AN ISOLATED SHOWER OR THUNDERSTORM COULD AFFECT THE NORTHWEST
ARKANSAS TAF SITES IN THE FIRST COUPLE HOURS OF THE FORECAST
PERIOD...BUT THE CHANCES ARE TOO LOW TO INCLUDE IN THE TAFS.
MAINLY VFR CONDITIONS WILL PREVAIL THROUGH THE FORECAST PERIOD
WITH GUSTY SOUTH WINDS DEVELOPING DURING THE DAY SATURDAY. THE
ARKANSAS TAF SITES MAY SEE VISIBILITIES OCCASIONALLY FALL INTO THE
MVFR CATEGORY IN LIGHT FOG LATE TONIGHT AND EARLY SATURDAY.
&&
.PREV DISCUSSION... /ISSUED 843 PM CDT FRI MAY 9 2014/
..UPDATE...
DISCUSSION...
MAIN UPDATE TO THE GOING FORECAST HAS BEEN TO PULL THUNDERSTORM
CHANCES BACK TO THE NORTHWEST A BIT OVERNIGHT INTO PARTS OF
NORTHEAST AND EAST CENTRAL OKLAHOMA AND ALSO MOST OF NORTHWEST
ARKANSAS. BOTH THE HRRR AND THE LOCAL WRF FAVORING SOME
THUNDERSTORM DEVELOPMENT ALONG THE DIFFUSE BOUNDARY TOWARD
MIDNIGHT IN EAST CENTRAL OKLAHOMA AND NORTHWEST ARKANSAS AS THE
MID LEVEL VORT MAX SWINGS ACROSS EASTERN OKLAHOMA AND INTO WESTERN
ARKANSAS. SOME SEVERE POTENTIAL WOULD EXIST WITH ANY DEVELOPMENT
ESPECIALLY GIVEN COLDER UPPER LEVEL TEMPS ASSOCIATED WITH THE VORT
MAX. REMAINDER OF THE GOING FORECAST OKAY.
PREV DISCUSSION... /ISSUED 619 PM CDT FRI MAY 9 2014/
AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
MAINLY VFR CONDITIONS WILL PREVAIL THROUGH THE FORECAST PERIOD.
VISIBILITIES MAY BE REDUCED INTO THE MVFR CATEGORY AT TIMES IN
LIGHT FOG LATE TONIGHT AND EARLY SATURDAY...MAINLY AT THE ARKANSAS
TAF SITES.
PREV DISCUSSION... /ISSUED 304 PM CDT FRI MAY 9 2014/
DISCUSSION...
DIFFUSE SURFACE FRONT CONTINUES TO SLIDE VERY SLOWLY SE THIS
AFTERNOON...AND ESSENTIALLY SEPARATES THE 45-60F DEWPOINTS IN NE OK
AND 60+ DEWPOINTS ELSEWHERE. THERE REMAINS A SLIM CHANCE OF
THUNDERSTORM DEVELOP LATER THIS AFTERNOON NEAR AND AHEAD OF THE
QUASI-STATIONARY BOUNDARY...ALTHOUGH BEST CHANCES WILL LIKELY REMAIN
EAST OF OUR FORECAST AREA.
THE SURFACE FRONT WILL LIFT BACK N THROUGH THE AREA OVERNIGHT...AND
COULD SEE SOME ELEVATED MORNING CONVECTION ACROSS PARTS OF NE OK/NW
AR SATURDAY MORNING. AFTERNOON DESTABILIZATION SHOULD EVENTUALLY
LEAD TO THUNDERSTORM DEVELOPMENT ALONG THE STRENGTHENING COLD FRONT
OVER ERN KS SWWD TO THE TRIPLE POINT REGION OVER NWRN OK BY LATE
AFTERNOON/EARLY EVENING. BULK OF CONVECTION IS EXPECTED TO REMAIN
ACROSS KS THROUGH THE OVERNIGHT HOURS...ALTHOUGH COULD SEE SOME
ACTIVITY ACROSS NE OK...IN ZONE OF 45-55KT LOW-LEVEL JET.
UPPER SYSTEM CURRENTLY OFF THE PAC NW COAST WILL MOVE INLAND
TODAY...AND EVENTUALLY CARVE OUT A LARGE-SCALE UPPER LOW ACROSS THE
SWRN STATES. PERSISTENT/MOIST SWLY UPPER FLOW IS FORECAST FOR THE
EARLY PART OF NEXT WEEK...AS THE UPPER LOW EJECTS OUT INTO THE PLAINS
IN SEVERAL PIECES. RAIN CHANCES INCREASE BY SUNDAY NIGHT AND
ESPECIALLY MONDAY/MONDAY NIGHT AS THE COLD FRONT ENTERS THE AREA.
THE SWLY UPPER FLOW WILL FAVOR BOTH PRE AND POST-FRONTAL
CONVECTION...WITH HEAVY RAINFALL LIKELY AT LEAST INTO TUESDAY
MORNING. WILL CONTINUE TO FAVOR THE SLIGHTLY SLOWER SOLUTION OF THE
ECMWF/CMC OVER THE MORE PROGRESSIVE GFS/DGEX...ALTHOUGH CONFIDENCE
FALLS OFF SOME TOWARD THE MIDDLE OF THE WEEK AS THE ECMWF/CMC HANG
ON TO RAINFALL WELL INTO WEDNESDAY.
COOLER/DRIER WEATHER IS EXPECTED THE REMAINDER OF THE WEEK.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
AVIATION...05
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
113 AM EDT SAT MAY 10 2014
.SYNOPSIS...
A WEAK FRONT WILL APPROACH THE CAROLINAS FROM THE WEST THIS EVENING
AND MOVE OVER THE REGION AND THEN WASH OUT ON SATURDAY. IN THE
FRONTS WAKE...VERY WARM SOUTHERLY FLOW WILL SPREAD BACK OVER THE
REGION AND PERSIST UNTIL ANOTHER FRONT APPROACHES THE REGION BY THE
MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
0515 UTC UPDATE...SKY COVER HAS BEEN ADJUSTED BASED ON THE LATEST
INFRARED SATELLITE IMAGERY. POPS HAVE BEEN ADJUSTED PER RADAR
TRENDS...FAVORING A DECREASE IN THE SC PIEDMONT AND THE NC MOUNTAINS.
AS 1015 PM...KGSP 88D INDICATED SEVERAL PATCHES OF LIGHT RETURNS
ACROSS THE REGION. LATEST MESOSCALE ANALYSIS INDICATED WIDESPREAD
CIN WITH VERY LIMITED CAPE. THE ONGOING LIGHT RAIN SHOULD GRADUALLY
DECREASE THROUGH THE REST OF TONIGHT...I WILL KEEP LOW CHC TO SCHC
POPS. THE HRRR INDICATES A FEW POCKETS OF SFC LOW COND PRES DEF
ACROSS THE WESTERN NC MTNS AND I-77 CORRDIOR BY DAYBREAK. IT IS
POSSIBLE THAT PATCHY FOG COULD DEVELOP OVER WET GROUND.
AS OF 750 PM...A LINE OF SHOWERS AND THUNDERSTORMS WAS RUNNING FROM
THE UPPER SAVANNAH RIVER VALLEY NE INTO THE NC FOOTHILLS...MOVING
EAST AT 20 MPH. AT THIS RATE...THE LINE WOULD REACH KAND AT 0025
Z...KGMU 0035Z...AND KGSP AROUND 1Z. I WILL UPDATE THE FORECAST TO
ADJUST TIMING.
AS OF 535 PM...TCLT AND KGSP RADARS INDICATE A CLUSTER OF
THUNDERSTORM SOUTH OF THE CLT METRO AREA AND A LINE OF THUNDERSTORMS
ARRIVING OVER EXTREME NE GA. THE STORMS ACROSS THE PIEDMONT HAVE A
HISTORY OF STRONG GUSTY WINDS WITH SMALL HAIL. THE THREAT OF GUSTY
WINDS SHOULD REMAIN AS DCAPE VALUES BORDER ON 1000 J/KG. IN
ADDITION...TORRENTIAL DOWNPOURS SHOULD RESULT AS THE CLUSTER TRACK
NE ACROSS CLT. THE LINE TO THE WEST SHOULD SWEEP EAST OVER THE NEXT
THREE HOURS. I WILL MAKE CHANGES TO MOST FORECAST FIELDS TO ALIGN
WITH LATEST OBS AND THINKING.
AS OF 230 PM...THE LATEST HIGH-RES MODEL RUNS ARE FINALLY STARTING
TO CATCH UP WITH THE DEVELOPING CONVECTION ACRS THE ERN UPSTATE AND
THE NC PIEDMONT (WHERE THEY EARLIER SHOWED LITTLE ACTIVITY) THIS
AFTN. I HAVE BUMPED UP POP TO CHC IN THE ERN ZONES WHERE IT USED TO
BE DRY OR ONLY SLGT CHC. THERE IS STILL ONLY 500-1000 J/KG OF SBCAPE
PER THE LAPS ANALYSIS...AND SHEAR IS WEEK. SO EXPECT MAINLY SHWRS
AND A FEW GARDEN VARIETY TSTMS. WITH THAT SAID...THE SPC
MESOANALYSIS PAGE SHOWS DCAPE OF 1000-1200 J/KG ACRS THE ERN 1/3RD
OF THE CWFA. SO EVEN SHWRS MAY PRODUCE SOME GUSTY WINDS. STILL THINK
SEVERE THREAT IS LOW...GIVEN THE LOW CAPE AND SHEAR. TO THE
WEST...THE EXTENSIVE CLOUDS ARE KEEPING THINGS CAPPED...WITH JUST
SPOTTY LIGHT SHWRS ACRS THE NC MTNS.
LATER THIS AFTN INTO THIS EVENING...SHWRS SHUD CONTINUE TO INCREASE
IN COVERAGE AS DEEP LAYER MOISTURE CONTINUES TO WORK IN FROM THE
WEST. BETTER INSTBY AND UPPER SUPPORT WILL ALSO SPREAD INTO THE SWRN
AND CENTRAL NC MTNS...INCREASING THE THREAT FOR TSTMS. AGAIN...NOT
EXPECTING MUCH SEVERE THREAT. SO THE POPS RAMPING UP TO SOLID CHC TO
LIKELY INTO THIS EVENING...HIGHEST WEST...STILL LOOKS GOOD.
TONIGHT...THE DEEP LAYER RH MAXIMUM AXIS WILL SPREAD INTO THE CWFA
AHEAD OF A WEAKENING COLD FRONT...WHICH WILL STILL BE BACK WEST ACRS
THE OH/TN VLYS. MOST OF THE GUIDANCE SEEMS TO AGREE IN GENERAL FOR A
DECREASING TREND IN SHWR COVERAGE AND INTENSITY. BUT WITH PLENTY OF
MOISTURE...THERE WILL PROBABLY BE AT LEAST SCATTERED LINGERING
ACTIVITY THRU THE OVERNIGHT. THE CLOUDS AND MOISTURE WILL KEEP TEMPS
ELEVATED ABOVE NORMAL...MAINLY IN THE 50S MTNS AND LWR-MID 60S
PIEDMONT.
SATURDAY...SOME OF THE CONVECTION-ALLOWING MODELS SHOW SOME SORT OF
MCS ACRS THE OH VLY...TURNING TOWARD THE SW TOWARD THE NRN MTNS
AROUND DAYBREAK. CONFIDENCE IS LOW...WITH NO MENTION OF THIS IN THE
SPC OUTLOOKS. OTHERWISE...I ACTUALLY EXPECT A LULL IN COVERAGE
DURING THE MORNING HOURS...AS INSTBY WILL BE AT ITS LOWEST.
STILL...POPS ONLY DROP SLIGHTLY BASED ON THE ONGOING MOIST SW FLOW.
THERE SHUD BE PLENTY OF CLOUD COVER THRU THE DAY...SO IT/S DIFFICULT
TO SAY HOW MUCH INSTBY THERE WILL BE FOR REDEVELOPMENT DURING THE
AFTN. WILL GO WITH HIGH-END CHC EAST TO LIKELY WEST FOR SHWRS AND
SCATTERED TSTMS. PROFILES CONTINUE TO SHOW FAIRLY MODEST CAPE AND
SHEAR FOR MORE ROBUST CONVECTION. SO SEVERE THREAT REMAINS LOW. THE
DAY 2 CONVECTIVE OUTLOOK KEEPS OUR AREA IN GENERAL THUNDER. THE
CLOUD COVER AND PRECIP SHUD KEEP TEMPS PRIMARILY IN THE 70S WEST TO
LWR 80S EAST.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY/...
AS OF 215 PM EDT FRI...MAJOR HEIGHT FALLS FROM THE ROCKIES TO THE
PLAINS SAT NIGHT THROUGH SUNDAY WILL ALLOW A RIDGE TO GRADUALLY
BUILD ACROSS THE SE LATE THIS WEEKEND. THE HIGHLY AMPLIFIED PATTERN
WILL BE FULLY IN PLACE BY MON...WITH A 588 DM H5 RIDGE ENTRENCHED
OVER THE SE. MAINLY A DIURNAL CONVECTIVE PATTERN IS EXPECTED UNDER
THE BUILDING RIDGE SUN AND MON AFTN/EVENING...BUT PERSISTENT S TO SW
LOW LEVEL FLOW COULD PROVIDE ISOLD SHRA COVERAGE IN UPSLOPE AREAS
EVEN DURING THE MORNING HOURS. THE STRONGEST CONVECTION OF THE
WEEKEND MAY ACTUALLY OCCUR SUNDAY AFTERNOON AND EVENING AS
INSOLATION IMPROVES...BOUNDARY LAYER MOISTURE REMAINS AND SLIGHT MID
LEVEL DRYING OCCURS BEFORE THE SE RIDGE REBOUNDS IN EARNEST. WILL
FEATURE SOLID SCATTERED DIURNAL POPS...MAINLY OVER THE MTNS...EACH
AFTN/EVENING. EXPECT MINS AND MAXES TO RUN TWO CATEGORIES OR MORE
ABOVE CLIMO THROUGH THE SHORT RANGE PERIOD.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 130 PM EDT THURSDAY...THE MEDIUM RANGE FCST PICKS UP AT 00Z ON
TUESDAY WITH UPPER RIDGING IN PLACE OVER THE SE CONUS AND DEEP UPPER
TROFFING OVER THE CENTRAL AND SOUTHERN ROCKIES. OVER THE NEXT FEW
DAYS...THE TROF WILL GRADUALLY MAKE ITS WAY EAST AND TOWARDS THE
CAROLINAS AS THE RIDGE GETS PUSHED OFFSHORE. THE TIMING DIFFERENCES
AMONG THE LONG MODELS HAVE BEEN REDUCED SINCE YESTERDAYS FCST YET
THE GFS IS STILL ABOUT 12 TO 24HRS FASTER WITH THE TROFS APPROACH
COMPARED TO THE GFS AND THE CANADIAN. THE OVERALL TREND OF THE FCST
HAS BEEN TO LEAN MORE TOWARDS A SLOWER...ECMWF TYPE SOLUTION WHICH I
WILL CONTINUE TO ADVERTISE. AT ANY RATE...THE MODELS DO AGREE THAT
THE TROF SHOULD SLOW DOWN AS IT MOVES OVER THE EASTERN CONUS TOWARDS
THE END OF THE MEDIUM RANGE AND STILL BE OVER THE REGION BY NEW DAY
7.
AT THE SFC...THE BERMUDA HIGH WILL BE FIRMLY IN PLACE OVER THE
REGION AT THE START OF THE PERIOD WITH WARM SLY LOW LVL FLOW
PERSISTING OVER THE CWFA FOR MOST OF THE PERIOD. AS WITH THE UPPER
LVL PATTERN...THE GFS HAS BEEN SLOWING THE APPROACH OF THE NEXT
FRONTAL SYSTEM AND IS NOW MORE IN LINE WITH THE ECMWF. THE FRONT IS
NOW MORE LIKELY TO MOVE INTO THE WESTERN CAROLINAS BY LATE WED/EARLY
THURS AND BY EARLY FRI...THE SYSTEM SHOULD EAST OF THE CWFA. SOME
DEGREE OF DRIER AND COOLER SFC RIDGING SHOULD MOVE IN BEHIND THE
FROPA FOR THE REMAINDER OF THE PERIOD WITH LITTLE CHANCE FOR PRECIP.
THE ECMWF AND ESPECIALLY THE CANADIAN MODELS STILL DEVELOP SOME SORT
OF LOW TO OUR SE JUST OFF THE COAST OF FLORIDA BY THE END OF THE
PERIOD...THE CANADIAN NOW TRYING TO SPIN UP A FULL BLOWN TROPICAL
SYSTEM. AS FOR THE SENSIBLE FCST...NO SIGNIFICANT CHANGES WERE
NEEDED. I DID PUSH BACK THE BEST WINDOW FOR WIDESPREAD SHOWERS AND
TS BY ABOUT 6 TO 12HRS BASED ON A SLOWER FRONTAL APPROACH AND FROPA.
BY 00Z FRI...ONLY A SLIGHT CHANCE LINGERS OVER THE EASTERN ZONES
WITH A DRY FCST FOR THE REST OF FRI. TEMPS WILL DROP A FAIR AMOUNT
ON WED AND THURS AS CLOUD COVER INCREASES AND THE FRONT PASSES THRU.
ON FRI...VALUES WILL PERSIST AROUND NORMAL FOR MID MAY.
&&
.AVIATION /05Z SATURDAY THROUGH WEDNESDAY/...
AT KCLT...THE LATEST MODEL GUIDANCE SUGGESTS BRIEF LOW VFR CIGS
BEFORE DAWN...OTHERWISE A MID TO HIGH CIG WILL PERSIST UNTIL LATE
AFTERNOON OR EARLY EVENING. MODEL GUIDANCE STILL HAS VFR VSBY AT
DAYBREAK...BUT WITH RAIN SOAKED GROUND IN THE AREA...CONFIDENCE IS
LOWER ON VFR. ARES JUST WEST OF KCLT HAVE A BETTER CHANCE OF FOG. SW
WINDS WILL INCREASE AND BECOME GUSTY AFTER DAWN....DIMINISHING AFTER
SUNSET. ANOTHER ROUND OF THUNDERSTORMS IS EXPECTED DURING THE
DAY...AS A WEAKENING COLD FRONT ARRIVES...WITH THE BEST CHANCE IN
THE AFTERNOON.
ELSEWHERE...SOME MODEL GUIDANCE MEMBERS ARE SUPPORTIVE OF FOG
RELATED VSBY RESTRICITONS TOWARD DAYBREAK...ESPECIALLY IN THE
MOUNTAINS AND UPPER SAVANNAH RIVER VALLEY...AND WITH RAIN SOAKED
GROUND...THE FORECAST WILL LEAN IN THAT DIRECTION. GUIDANCE SUPPORTS
LOW VFR CIGS DEVELOPING BENEATH MID TO HIGH CLOUDS BY DAWN...THAT
GRADUALLY BREAK UP IN THE AFTERNOON. SW WINDS WILL INCREASE AND
BECOME GUSTY DURING THE DAY...THEN DIMINISH IN THE EVENING. AN
APPROACHING COLD FRONT WILL SUPPORT MORE THUNDERSTORMS TODAY...WITH
THE BEST CHANCE IN THE AFTERNOON DURING MAXIMUM HEATING.
OUTLOOK...A WEAK COLD FRONT WILL BRING CHANCES FOR PRECIPITATION
THROUGH SATURDAY NIGHT...WITH RESTRICTIONS POSSIBLE IN
THUNDERSTORMS. HIGH PRESSURE RETURNS SUNDAY AND MONDAY...BUT
AFTERNOON AND EVENING CONVECTION WILL BE POSSIBLE BOTH DAYS.
CONFIDENCE TABLE...
05-11Z 11-17Z 17-23Z 23-05Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 95% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 95% 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 95% 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...JPT
NEAR TERM...ARK/JAT/NED
SHORT TERM...HG
LONG TERM...JPT
AVIATION...JAT
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
917 PM CDT SUN MAY 11 2014
.DISCUSSION...MINOR TEMPERATURE/DEW POINT ADJUSTMENTS TO FALL IN
LINE WITH CURRENT/FORECAST TEMPERATURES. SEE NO REASON AT THIS
TIME TO MAKE OTHER CHANGES INLAND AREAS.
&&
.MARINE...INCLUDED PATCHY FOG FOR THE MARINE ZONES AND SOME
LOCATIONS REPORTING 2-5SM. WILL PUT A BRIEF MENTION OF THIS IN
MWW. AM KEEPING SCA GOING AS THIS IS WHAT THE RUC IS SHOWING AND
OTHER MODELS TOO.
&&
.PREV DISCUSSION... /ISSUED 644 PM CDT SUN MAY 11 2014/
DISCUSSION...UPDATE FOR 00Z AVIATION DISCUSSION.
AVIATION...DETERIORATING FLIGHT RULES OVERNIGHT. MVFR EARLY IN
THE TAF PERIOD AT KCRP/KVCT/KALI WITH CONDITIONS QUICKLY LOWERING
TO IFR BY MID EVENING...AND REMAINING AT IFR OVERNIGHT. KLRD SHOULD
REMAIN VFR THRU MUCH OF THE NIGHT WITH CIGS LOWERING TO IFR BY
LATE IN THE NIGHT. CIGS AT ALL TERMINALS WILL SLOWLY RISE MON
MRNG WITH MVFR TO VFR RETURNING TO KLRD BY LATE MRNG...KALI BY
MIDDAY...WITH KCRP/KVCT LIKELY REMAINING AT MVFR THRU MON AFTN.
ISO CONVECTION MAY APPROACH KLRD BY LATE MON AFTN BUT BETTER
CHANCES WILL OCCUR JUST BEYOND VALID TAF TIME FRAME...SO WILL ONLY
INCLUDE VCTS FOR NOW. ELSEWHERE...CURRENTLY XPCT KCRP/KVCT/KALI
TO REMAIN DRY THRU THE TAF PERIOD ASIDE FROM SOME BRIEF -DZ.
MODERATE/GUSTY SE WINDS THIS EVENING WILL REMAIN BETWEEN 08-14 KTS
OVERNIGHT...WITH GUSTY SE WINDS RETURNING FOR MIDDAY/AFTN HRS OF
MON.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 75 88 73 76 59 / 10 30 50 70 60
VICTORIA 74 88 72 75 57 / 10 30 60 70 60
LAREDO 77 96 74 80 61 / 10 40 70 60 40
ALICE 74 91 72 77 58 / 10 30 60 70 60
ROCKPORT 75 84 73 75 62 / 10 20 40 70 60
COTULLA 75 92 71 77 57 / 10 40 70 50 40
KINGSVILLE 76 90 73 77 59 / 10 30 50 70 60
NAVY CORPUS 75 84 73 75 61 / 10 20 40 60 60
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 7 AM CDT MONDAY FOR THE FOLLOWING
ZONES: COASTAL WATERS FROM BAFFIN BAY TO PORT ARANSAS OUT
20 NM...COASTAL WATERS FROM PORT ARANSAS TO MATAGORDA SHIP
CHANNEL OUT 20 NM...WATERS FROM BAFFIN BAY TO PORT ARANSAS
FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS TO MATAGORDA
SHIP CHANNEL FROM 20 TO 60 NM.
&&
$$
GW/86...SHORT TERM
AREA FORECAST DISCUSSION...UPDATED
NWS SAN ANGELO TX
813 PM CDT Sun May 11 2014
.DISCUSSION...
Despite the instability in place and persistent cumulus field,
thunderstorms have not developed along the dryline so far this
evening in the eastern TX Panhandle or Low Rolling Plains east of
Lubbock. Surface convergence is weak and upper forcing is still
lagging to the west over the southern Rockies. The dryline farther
south is retreating to the west. The GFS looks to be the the most
optimistic with convective development early tonight before 06Z in
our northern and western counties. Recent HRRR and Texas Tech WRF,
however, hold off with shower/thunderstorm development until 2-3
hours after Midnight across our far western counties. The Texas Tech
WRF indicates possibility of isolated thunderstorm development near
our northwestern border counties (Fisher and Nolan Counties) late
this evening/early tonight. Given the satellite and model trends,
have scaled back the PoPs early tonight with slight chance confined
to the the area west of Haskell to Sweetwater before 2 AM. With the
instability and deep layer shear, severe potential remains for any
storms which can develop on the dryline. As large scale ascent
begins to impinge on the area late tonight, could have
shower/thunderstorm development across our west and northwest
counties, spreading east overnight and early Monday morning.
Carrying 30-40 PoPs across the area north and west of a San Angelo
to Baird line late tonight. Have also adjusted sky condition to
clear skies this evening based on satellite indications. Updated
forecast will be out shortly.
19
&&
.PREV DISCUSSION... /ISSUED 650 PM CDT SUN MAY 11 2014/
AVIATION...
/00Z TAFS/
Thunderstorms and MVFR ceilings are possible across West Central
Texas during the next 24 hours. Forecast models indicate stratus
will return to our southern terminals a couple hours after midnight.
The best timing for thunderstorms will also begin after midnight and
continue through tomorrow, as another cold front moves into West
Central Texas.
Huber
PREV DISCUSSION... /ISSUED 335 PM CDT SUN MAY 11 2014/
SHORT TERM...
(Tonight and Monday)
A fairly complex weather forecast can be expected through the
next 24 hours. Currently a dryline is located west of the area,
with all of West Central Texas experiencing dewpoints in the mid
50s to lower 60s. The dryline is forecast to continue to sharpen
to our west this afternoon, with an increasingly unstable
atmosphere ahead of it. The main caveat is the lack of upper level
forcing, and whether we are able to break the cap late this
afternoon or early this evening. My current thinking is that we
will see at least isolated convection along the dryline, mainly
beginning this evening as better upper level forcing arrives, then
moving east late this evening and early Monday morning. A
strengthening low level jet should help to sustain any convection
that does develop, with most convection waning by sunrise. Any
storms that do develop this evening, have the potential to become
strong to severe, with large hail and damaging winds being the
main hazards.
The main feature of interest on Monday is a cold front that will
slowly move through the area. The front is forecast to move into the
northern Big Country late Monday morning, then into the Concho
Valley during the afternoon, with a dryline extending south across
the northern Edwards Plateau. Showers and thunderstorms are forecast
to develop along and ahead of the front late in the morning, then
increase in coverage by mid to late afternoon. At this time, the
best coverage and heaviest rainfall looks to generally east of a
Cross Plains, to Eden, to Junction line, where precipitable water
values of 1 to 1.5 inches are forecast. Again, a few storms could
become strong to severe, with large hail and damaging winds being
the main hazards.
Daniels
LONG TERM...
(Monday night through Sunday)
..A heavy rainfall threat will exist through Monday night...
A very slow moving cold front will ease across the southeast
quadrant of the CWA Monday night, providing a low-level focus for
convective development. Ascent will be aided by strong upper-level
divergence in the right entrance region to the polar jet. Forecast
precipitable water values Monday night are progged to be in the
1.4 to 1.7" range, about 2 standard deviations above the mean for
this time of year. The 0-6km shear vector will be nearly parallel
with the aforementioned frontal boundary, suggesting that storms
may train along the baroclinic zone, enhancing the potential for
locally heavy rainfall. Widespread showers and thunderstorms will
result in general rainfall amounts of 1-3", with locally higher
amounts, generally east of a Cross Plains to Junction line.
Farther west, QPF amounts are quite a bit lighter, but a good 1/4"
of rain or more is expected from Sweetwater south to Sonora. There
is a threat for severe thunderstorms as well, mainly during the
afternoon and evening hours before convection congeals into a
multicell mess. The primary threats will be large hail and
damaging winds.
The cold front will be south of the area by Tuesday morning with
north winds of 15-20 mph expected throughout the day. Upper-level
forcing will remain present, but without the frontal forcing, it
looks like precipitation will be weaker, with thunder becoming
less likely. PoPs in the 20-40% range were carried southeast of
an Ozona to Cross Plains line, but rainfall amounts should remain
less than 1/4" on average. Temperatures will be noticeably cooler
on Tuesday with highs generally in the mid 60s. The NAM is still
keeping highs in the 50s across the area but this seems a bit
extreme.
Precip is expected to come to an end by Tuesday evening with drier
air advecting into the area overnight. As winds decrease, the
dry air should allow fairly strong decoupling of the boundary
layer. With skies clearing, temps are expected to fall into the
low/mid 40s. North to northeast winds on Wednesday will keep temps
on the cool side, with highs only the 70s. We`re in store for
another cool morning on Thursday with 40s once again expected
across most of the area.
Generally benign weather conditions are expected through the
remainder of the forecast period. Dry northwesterly flow
downstream of the western CONUS ridge will promote mostly clear
skies. Southerly winds will resume across the area by Thursday as
lee cyclogenesis ramps up. With the return flow, temps will
rebound quickly into the 80s with highs expected to reach 90
degrees over the weekend. This is a potential cold front we`ll
have to watch out for Friday into Saturday as a potent shortwave
trough moves across the central Plains. However, the current model
guidance stalls this boundary near the Red River, maintaining
southerly winds across the region.
Johnson
FIRE WEATHER...
Elevated fire weather conditions are forecast across the western
Concho Valley and Crockett County Monday afternoon. Minimum relative
humidity values will drop below 20 percent, but 20 foot winds will
remain light. Elevated fire weather conditions will once again be
possible across much of West Central Texas Wednesday through Friday,
as minimum relative humidity values drop to 15 to 20 percent, but 20
foot winds generally remain below 15 mph.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 69 80 50 66 46 / 30 40 20 10 5
San Angelo 69 84 52 65 44 / 30 30 30 10 5
Junction 72 82 57 68 47 / 10 50 70 40 10
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS SAN ANGELO TX
805 PM CDT Sun May 11 2014
.DISCUSSION...
Despite the instability in place and persistent cumulus field,
thunderstorms have not developed along the dryline so far this
evening in the eastern TX Panhandle or Low Rolling Plains east of
Lubbock. Surface convergence is weak and upper forcing is still
lagging to the west over the southern Rockies. The dryline farther
south is retreating to the west. The GFS looks to be the the most
optimistic with convective development early tonight before 06Z in
our northern and western counties. Recent HRRR and Texas Tech WRF,
however, hold off with shower/thunderstorm development until 2-3
hours after Midnight across our far western counties. The Texas
Tech 3km WRF indicates possibility of isolated thunderstorm
development near our northwestern border counties (Fisher and
Nolan Counties) late this evening/early tonight. Given the
satellite and model trends, have scaled back the PoPs early
tonight with slight chance confined to the the area west of
Haskell to Sweetwater before 2 AM. With the instability and deep
layer shear, severe potential remains for any storms which can
develop on the dryline. As large scale ascent begins to impinge on
the area late tonight, could have shower/thunderstorm development
across our west and northwest counties, spreading east overnight
and early Monday morning. To varying extent, the HRRR and Texas
Tech 3 Carrying 30-40 PoPs across the area north and west of a San
Angelo to Baird line late tonight. Have also adjusted sky
condition to clear skies this evening based on satellite
indications. Updated forecast will be out shortly.
19
&&
.PREV DISCUSSION... /ISSUED 650 PM CDT SUN MAY 11 2014/
AVIATION...
/00Z TAFS/
Thunderstorms and MVFR ceilings are possible across West Central
Texas during the next 24 hours. Forecast models indicate stratus
will return to our southern terminals a couple hours after midnight.
The best timing for thunderstorms will also begin after midnight and
continue through tomorrow, as another cold front moves into West
Central Texas.
Huber
PREV DISCUSSION... /ISSUED 335 PM CDT SUN MAY 11 2014/
SHORT TERM...
(Tonight and Monday)
A fairly complex weather forecast can be expected through the
next 24 hours. Currently a dryline is located west of the area,
with all of West Central Texas experiencing dewpoints in the mid
50s to lower 60s. The dryline is forecast to continue to sharpen
to our west this afternoon, with an increasingly unstable
atmosphere ahead of it. The main caveat is the lack of upper level
forcing, and whether we are able to break the cap late this
afternoon or early this evening. My current thinking is that we
will see at least isolated convection along the dryline, mainly
beginning this evening as better upper level forcing arrives, then
moving east late this evening and early Monday morning. A
strengthening low level jet should help to sustain any convection
that does develop, with most convection waning by sunrise. Any
storms that do develop this evening, have the potential to become
strong to severe, with large hail and damaging winds being the
main hazards.
The main feature of interest on Monday is a cold front that will
slowly move through the area. The front is forecast to move into the
northern Big Country late Monday morning, then into the Concho
Valley during the afternoon, with a dryline extending south across
the northern Edwards Plateau. Showers and thunderstorms are forecast
to develop along and ahead of the front late in the morning, then
increase in coverage by mid to late afternoon. At this time, the
best coverage and heaviest rainfall looks to generally east of a
Cross Plains, to Eden, to Junction line, where precipitable water
values of 1 to 1.5 inches are forecast. Again, a few storms could
become strong to severe, with large hail and damaging winds being
the main hazards.
Daniels
LONG TERM...
(Monday night through Sunday)
..A heavy rainfall threat will exist through Monday night...
A very slow moving cold front will ease across the southeast
quadrant of the CWA Monday night, providing a low-level focus for
convective development. Ascent will be aided by strong upper-level
divergence in the right entrance region to the polar jet. Forecast
precipitable water values Monday night are progged to be in the
1.4 to 1.7" range, about 2 standard deviations above the mean for
this time of year. The 0-6km shear vector will be nearly parallel
with the aforementioned frontal boundary, suggesting that storms
may train along the baroclinic zone, enhancing the potential for
locally heavy rainfall. Widespread showers and thunderstorms will
result in general rainfall amounts of 1-3", with locally higher
amounts, generally east of a Cross Plains to Junction line.
Farther west, QPF amounts are quite a bit lighter, but a good 1/4"
of rain or more is expected from Sweetwater south to Sonora. There
is a threat for severe thunderstorms as well, mainly during the
afternoon and evening hours before convection congeals into a
multicell mess. The primary threats will be large hail and
damaging winds.
The cold front will be south of the area by Tuesday morning with
north winds of 15-20 mph expected throughout the day. Upper-level
forcing will remain present, but without the frontal forcing, it
looks like precipitation will be weaker, with thunder becoming
less likely. PoPs in the 20-40% range were carried southeast of
an Ozona to Cross Plains line, but rainfall amounts should remain
less than 1/4" on average. Temperatures will be noticeably cooler
on Tuesday with highs generally in the mid 60s. The NAM is still
keeping highs in the 50s across the area but this seems a bit
extreme.
Precip is expected to come to an end by Tuesday evening with drier
air advecting into the area overnight. As winds decrease, the
dry air should allow fairly strong decoupling of the boundary
layer. With skies clearing, temps are expected to fall into the
low/mid 40s. North to northeast winds on Wednesday will keep temps
on the cool side, with highs only the 70s. We`re in store for
another cool morning on Thursday with 40s once again expected
across most of the area.
Generally benign weather conditions are expected through the
remainder of the forecast period. Dry northwesterly flow
downstream of the western CONUS ridge will promote mostly clear
skies. Southerly winds will resume across the area by Thursday as
lee cyclogenesis ramps up. With the return flow, temps will
rebound quickly into the 80s with highs expected to reach 90
degrees over the weekend. This is a potential cold front we`ll
have to watch out for Friday into Saturday as a potent shortwave
trough moves across the central Plains. However, the current model
guidance stalls this boundary near the Red River, maintaining
southerly winds across the region.
Johnson
FIRE WEATHER...
Elevated fire weather conditions are forecast across the western
Concho Valley and Crockett County Monday afternoon. Minimum relative
humidity values will drop below 20 percent, but 20 foot winds will
remain light. Elevated fire weather conditions will once again be
possible across much of West Central Texas Wednesday through Friday,
as minimum relative humidity values drop to 15 to 20 percent, but 20
foot winds generally remain below 15 mph.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 69 80 50 66 46 / 30 40 20 10 5
San Angelo 69 84 52 65 44 / 30 30 30 10 5
Junction 72 82 57 68 47 / 10 50 70 40 10
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1247 PM CDT SAT MAY 10 2014
.AVIATION...
CONTINUED VFR WITH 15-20 KNOT SOUTHWEST WINDS BACKING SOUTH
AROUND SUNSET. SLIM CHANCE THAT A FEW LOW CLOUDS COULD SNEAK INTO
THE TERMINALS SUN MORNING EAST OF A DRYLINE BEFORE GUSTY SW WINDS
RESUME AT THE TERMINALS AROUND 18Z.
&&
PREV DISCUSSION... /ISSUED 440 AM CDT SAT MAY 10 2014/
SHORT TERM...
LATER THIS MORNING...WINDS WILL INITIALLY INCREASE WITH LOW LEVEL
JET WINDS QUICKLY MIXING DOWN TO THE SURFACE...ESPECIALLY FOR AREAS
OFF THE CAPROCK. OBSERVATIONAL ANALYSIS AND RAP FORECASTS SHOW
40-50KT WINDS WITHIN 1 KFT OF THE SURFACE EARLY THIS MORNING
MAXIMIZED OVER THE ROLLING PLAINS. THERE WILL THEN LIKELY BE A
SLIGHT LULL IN WINDS LATE MORNING BEFORE STRONG WINDS TAKE OVER IN
THE AFTERNOON. DEEP MIXING IS PROGGED TO BE APPROXIMATELY TO 600MB.
HOWEVER...WINDS AROUND THIS LEVEL ARE NOT THAT NOTABLE. AN INCREASE
IN THESE WINDS WILL OCCUR BY LATE IN THE AFTERNOON BUT THIS IS MORE
ASSOCIATED WITH THE APPROACHING TROUGH WHICH IS CURRENTLY NEAR
TROUTDALE OR. STRENGTHENING SURFACE CYCLOGENESIS OVER SOUTHEASTERN
COLORADO WILL BRING THE WINDS UP DURING THE AFTERNOON.
THE APPROACHING TROUGH WILL ASSIST IN A MOISTURE SURGE BACK TO THE
WEST AND POSSIBLY TO THE STATE LINE ON SUNDAY MORNING. THERE MAY BE
A SHOT AT SOME BRIEF LOW STRATUS ON SUNDAY MORNING COMING UP FROM
THE SOUTHEAST.
LONG TERM...
PRIMARY FOCUS REVOLVED AROUND THE IMPACTS OF A DEEPENING UPPER
LEVEL LOW PRESSURE SYSTEM ROLLING THROUGH THE FOUR-CORNERS LATE
SUNDAY. SHALLOW RICH MOISTURE EARLY SUNDAY IS EXPECTED TO BE
SHUNTED EAST WITH ONSET OF MIXING AND FAIRLY STRONG DOWNSLOPE
WINDS...WITH A MORE DIFFUSE DRY-LINE EVENTUALLY RESIDING OVER OUR
EASTERN AND SOUTHEAST BORDER AREAS LATE IN THE DAY. BACKING FLOW
SUNDAY EVENING SHOULD PULL TIGHTENED DRY-LINE WEST TO NEAR THE
CAP-ROCK AS AIRMASS DESTABILIZES THOUGH STILL DISAGREEMENT OVER
ABILITY OF THUNDERSTORMS TO DEVELOP ALONG THE DRYLINE ITSELF. A
SHARP COLD FRONT DRIVING SOUTHWARD SUNDAY NIGHT MAY BE NEEDED TO
ACTIVATE THUNDERSTORMS...ESPECIALLY AS IT NEARS THE DRY-LINE. WE
MADE ONLY MINOR ADJUSTMENTS WITH THIS ATTEMPT WITH NET IMPACT TO
RETAIN PREVIOUS LOW MENTION MAINLY EASTERN ZONES SUNDAY NIGHT.
MUCH COOLER/COLDER AIR WILL SWEEP SOUTHWARD EARLY MONDAY WITH
STIFF NORTHERLY BREEZES AS A 1030+ MB SURFACE RIDGE PRESSES
SOUTHWARD FROM THE ROCKIES. THIS EVENTUALLY MAY LEAD TO A RISK FOR
A LIGHT FREEZE OR FROST ACROSS OUR NORTHWEST ZONES TUESDAY AND
WEDNESDAY MORNINGS. LATEST WRF/NAM THREW A BIT MORE DOUBT INTO THE
EARLY WEEK FORECAST WITH A SHARPER TROUGH DIGGING THROUGH THE
SOUTHERN ROCKIES TOWARDS SOUTHERN HIGH PLAINS EARLY TUESDAY ALONG
WITH MORE WIDESPREAD LIGHT PRECIPITATION IN THE COLD AIR. WE HAVE
EXPANDED CLOUD COVER MONDAY NIGHT INTO TUESDAY AND ALSO LOWERED
TUESDAY MAXIMUMS A LITTLE MORE THOUGH NOT ENOUGH AGREEMENT AMONG
VARIOUS SOLUTIONS FOR A MENTION OF PRECIPITATION TUESDAY. DRY
OTHERWISE WITH SLOW WARMING LATER IN THE WEEK. SIGNIFICANT LOW
LEVEL MOISTURE UNLIKELY TO RETURN THROUGH NEXT WEEK. RMCQUEEN
FIRE WEATHER...
THIS AFTERNOON WILL LIKELY SEE MORE WIDE SPREAD FIRE WEATHER
CONCERNS BUT LOW END CRITICAL CONDITIONS ARE EXPECTED TO BE BRIEF
AND INTERMITTENT. WINDS WILL INCREASE BY EARLY AFTERNOON WITH
HIGHEST WINDS EXPECTED TO BE ACROSS THE WESTERN SOUTH PLAINS. WINDS
AT THE 20 FOOT LEVEL WILL LIKELY BE AROUND OR JUST SLIGHTLY ABOVE 20
MPH AT THE PEAK. TEMPERATURES AROUND 10 DEGREES ABOVE SEASONAL
AVERAGES AND VERY DRY AIR WILL HAVE NO ISSUE IN GENERATING RELATIVE
HUMIDITY VALUES BELOW 10 PERCENT.
SUNDAY CONTINUES TO LOOK LIKELY AS A CRITICAL FIRE WEATHER DAY AS
SHARP UPPER LEVEL LOW PRESSURE SYSTEM DIGS INTO THE FOUR-CORNERS
AREA LATE BY 00Z MONDAY. THIS SHOULD SPREAD STRONGER WIND FIELDS
ACROSS THE REGION LATE SUNDAY AFTERNOON AND MAY EVEN LEAD TO
EXTREMELY CRITICAL CONDITIONS AS NOTED BY THE SPC. WE CONTINUE TO
HAVE QUESTION ABOUT THE TOTAL MASS AND CONTINUITY OF FUEL LOAD
ESPECIALLY OVER THE HIGH PLAINS GIVEN THE ON-GOING DROUGHT THOUGH
AGREE THAT EVEN MORE LIMITED FUELS WILL BE PUSHED HARD BY SUNDAYS
EXPECTED 25-30 MPH WIND SPEEDS COMBINED WITH THE HOT TEMPERATURES
AND VERY LOW HUMIDITY. PREVIOUS WATCH AREA STILL VALID SO NO
CHANGES THIS FORECAST. RMCQUEEN
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 88 54 88 42 62 / 0 0 0 10 0
TULIA 90 59 92 45 64 / 0 0 0 10 0
PLAINVIEW 92 61 93 47 66 / 0 0 0 10 0
LEVELLAND 92 57 93 48 69 / 0 0 0 10 0
LUBBOCK 95 63 95 49 70 / 0 0 0 10 0
DENVER CITY 92 55 92 50 72 / 0 0 0 10 0
BROWNFIELD 93 59 93 51 72 / 0 0 0 10 0
CHILDRESS 96 64 98 56 70 / 0 0 10 30 10
SPUR 95 65 97 57 73 / 0 0 0 20 10
ASPERMONT 98 68 98 62 75 / 0 0 10 30 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING
FOR THE FOLLOWING ZONES: TXZ021>025-027>031-033>037-039>042.
&&
$$
93
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
440 AM CDT SAT MAY 10 2014
.SHORT TERM...
LATER THIS MORNING...WINDS WILL INITIALLY INCREASE WITH LOW LEVEL
JET WINDS QUICKLY MIXING DOWN TO THE SURFACE...ESPECIALLY FOR AREAS
OFF THE CAPROCK. OBSERVATIONAL ANALYSIS AND RAP FORECASTS SHOW
40-50KT WINDS WITHIN 1 KFT OF THE SURFACE EARLY THIS MORNING
MAXIMIZED OVER THE ROLLING PLAINS. THERE WILL THEN LIKELY BE A
SLIGHT LULL IN WINDS LATE MORNING BEFORE STRONG WINDS TAKE OVER IN
THE AFTERNOON. DEEP MIXING IS PROGGED TO BE APPROXIMATELY TO 600MB.
HOWEVER...WINDS AROUND THIS LEVEL ARE NOT THAT NOTABLE. AN INCREASE
IN THESE WINDS WILL OCCUR BY LATE IN THE AFTERNOON BUT THIS IS MORE
ASSOCIATED WITH THE APPROACHING TROUGH WHICH IS CURRENTLY NEAR
TROUTDALE OR. STRENGTHENING SURFACE CYCLOGENESIS OVER SOUTHEASTERN
COLORADO WILL BRING THE WINDS UP DURING THE AFTERNOON.
THE APPROACHING TROUGH WILL ASSIST IN A MOISTURE SURGE BACK TO THE
WEST AND POSSIBLY TO THE STATE LINE ON SUNDAY MORNING. THERE MAY BE
A SHOT AT SOME BRIEF LOW STRATUS ON SUNDAY MORNING COMING UP FROM
THE SOUTHEAST.
&&
.LONG TERM...
PRIMARY FOCUS REVOLVED AROUND THE IMPACTS OF A DEEPENING UPPER
LEVEL LOW PRESSURE SYSTEM ROLLING THROUGH THE FOUR-CORNERS LATE
SUNDAY. SHALLOW RICH MOISTURE EARLY SUNDAY IS EXPECTED TO BE
SHUNTED EAST WITH ONSET OF MIXING AND FAIRLY STRONG DOWNSLOPE
WINDS...WITH A MORE DIFFUSE DRY-LINE EVENTUALLY RESIDING OVER OUR
EASTERN AND SOUTHEAST BORDER AREAS LATE IN THE DAY. BACKING FLOW
SUNDAY EVENING SHOULD PULL TIGHTENED DRY-LINE WEST TO NEAR THE
CAP-ROCK AS AIRMASS DESTABILIZES THOUGH STILL DISAGREEMENT OVER
ABILITY OF THUNDERSTORMS TO DEVELOP ALONG THE DRYLINE ITSELF. A
SHARP COLD FRONT DRIVING SOUTHWARD SUNDAY NIGHT MAY BE NEEDED TO
ACTIVATE THUNDERSTORMS...ESPECIALLY AS IT NEARS THE DRY-LINE. WE
MADE ONLY MINOR ADJUSTMENTS WITH THIS ATTEMPT WITH NET IMPACT TO
RETAIN PREVIOUS LOW MENTION MAINLY EASTERN ZONES SUNDAY NIGHT.
MUCH COOLER/COLDER AIR WILL SWEEP SOUTHWARD EARLY MONDAY WITH
STIFF NORTHERLY BREEZES AS A 1030+ MB SURFACE RIDGE PRESSES
SOUTHWARD FROM THE ROCKIES. THIS EVENTUALLY MAY LEAD TO A RISK FOR
A LIGHT FREEZE OR FROST ACROSS OUR NORTHWEST ZONES TUESDAY AND
WEDNESDAY MORNINGS. LATEST WRF/NAM THREW A BIT MORE DOUBT INTO THE
EARLY WEEK FORECAST WITH A SHARPER TROUGH DIGGING THROUGH THE
SOUTHERN ROCKIES TOWARDS SOUTHERN HIGH PLAINS EARLY TUESDAY ALONG
WITH MORE WIDESPREAD LIGHT PRECIPITATION IN THE COLD AIR. WE HAVE
EXPANDED CLOUD COVER MONDAY NIGHT INTO TUESDAY AND ALSO LOWERED
TUESDAY MAXIMUMS A LITTLE MORE THOUGH NOT ENOUGH AGREEMENT AMONG
VARIOUS SOLUTIONS FOR A MENTION OF PRECIPITATION TUESDAY. DRY
OTHERWISE WITH SLOW WARMING LATER IN THE WEEK. SIGNIFICANT LOW
LEVEL MOISTURE UNLIKELY TO RETURN THROUGH NEXT WEEK. RMCQUEEN
&&
.FIRE WEATHER...
THIS AFTERNOON WILL LIKELY SEE MORE WIDE SPREAD FIRE WEATHER
CONCERNS BUT LOW END CRITICAL CONDITIONS ARE EXPECTED TO BE BRIEF
AND INTERMITTENT. WINDS WILL INCREASE BY EARLY AFTERNOON WITH
HIGHEST WINDS EXPECTED TO BE ACROSS THE WESTERN SOUTH PLAINS. WINDS
AT THE 20 FOOT LEVEL WILL LIKELY BE AROUND OR JUST SLIGHTLY ABOVE 20
MPH AT THE PEAK. TEMPERATURES AROUND 10 DEGREES ABOVE SEASONAL
AVERAGES AND VERY DRY AIR WILL HAVE NO ISSUE IN GENERATING RELATIVE
HUMIDITY VALUES BELOW 10 PERCENT.
SUNDAY CONTINUES TO LOOK LIKELY AS A CRITICAL FIRE WEATHER DAY AS
SHARP UPPER LEVEL LOW PRESSURE SYSTEM DIGS INTO THE FOUR-CORNERS
AREA LATE BY 00Z MONDAY. THIS SHOULD SPREAD STRONGER WIND FIELDS
ACROSS THE REGION LATE SUNDAY AFTERNOON AND MAY EVEN LEAD TO
EXTREMELY CRITICAL CONDITIONS AS NOTED BY THE SPC. WE CONTINUE TO
HAVE QUESTION ABOUT THE TOTAL MASS AND CONTINUITY OF FUEL LOAD
ESPECIALLY OVER THE HIGH PLAINS GIVEN THE ON-GOING DROUGHT THOUGH
AGREE THAT EVEN MORE LIMITED FUELS WILL BE PUSHED HARD BY SUNDAYS
EXPECTED 25-30 MPH WIND SPEEDS COMBINED WITH THE HOT TEMPERATURES
AND VERY LOW HUMIDITY. PREVIOUS WATCH AREA STILL VALID SO NO
CHANGES THIS FORECAST. RMCQUEEN
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 88 56 88 42 62 / 0 0 0 10 0
TULIA 90 59 91 45 64 / 0 0 0 10 0
PLAINVIEW 92 62 92 47 66 / 0 0 0 10 0
LEVELLAND 92 60 92 48 69 / 0 0 0 10 0
LUBBOCK 95 64 93 49 70 / 0 0 0 10 0
DENVER CITY 92 58 93 50 72 / 0 0 0 10 0
BROWNFIELD 93 62 93 51 72 / 0 0 10 10 0
CHILDRESS 96 69 96 56 70 / 0 0 10 20 10
SPUR 95 69 96 57 73 / 0 0 10 20 10
ASPERMONT 98 71 97 62 75 / 0 0 10 20 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING
FOR THE FOLLOWING ZONES: TXZ021>025-027>031-033>037-039>042.
&&
$$
01/05
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
938 PM CDT SUN MAY 11 2014
.UPDATE...
ISSUED AT 938 PM CDT SUN MAY 11 2014
WITH RAINFALL RATES OF 1 TO 2 INCHES PER HOUR POSSIBLE
OVERNIGHT AND GRB ADDING A FLASH FLOOD WATCH FOR SOME OF THEIR
COUNTIES IN NORTH CENTRAL WISCONSIN...HAVE DECIDED TO CHANGE OVER
THE FLOOD WATCH TO A FLASH FLOOD WATCH AND EXTEND IT THROUGH 6Z
TUESDAY WHEN THE COLD FRONT SHOULD BE CLEAR OF THE REGION. TIMING
OF THE COMPLEX MAKING IT INTO NORTHEAST IOWA STILL LOOKS GOOD FOR
AROUND MIDNIGHT NEAR THE I-35 CORRIDOR...IT IS JUST A MATTER OF
HOW INTENSE IT WILL BE AS IT GETS IN.
UPDATE ISSUED AT 855 PM CDT SUN MAY 11 2014
THE MAIN FOCUS WITH THE FORECAST IS WITH THE SEVERE WEATHER
POTENTIAL OVERNIGHT. CURRENT SURFACE ANALYSIS SHOWS A LOW PRESSURE
SYSTEM CENTERED NEAR OMAHA WHERE A BOWING COMPLEX HAS EMERGED FROM
A LONG TRACK HP SUPERCELL THAT TRACKED ACROSS SOUTHEAST NEBRASKA
THIS AFTERNOON. THE MAIN SURFACE WARM FRONT APPEARS TO EXTEND EAST
FROM OMAHA ACROSS SOUTHERN IOWA WITH AN INVERTED TROUGH EXTENDING
NORTH FROM THE LOW INTO SOUTHWEST MINNESOTA. ANOTHER DEW POINT
GRADIENT EXISTS ALONG THE MINNESOTA/IOWA BORDER WHERE DEW POINTS
GO FROM THE MID 50S IN SOUTHEAST MINNESOTA TO THE LOW 60S IN
NORTHEAST IOWA. 12.00Z RAP ANALYSIS SUGGESTS THAT THERE STILL IS
QUITE A BIT OF INSTABILITY AHEAD OF THIS COMPLEX RUNNING EAST
ACROSS IOWA WITH 0-3KM MUCAPE AROUND 2000 J/KG FROM DES MOINES
EAST AND AROUND 1000 J/KG RUNNING ALONG THE MINNESOTA/IOWA BORDER.
SURFACE BASED CAPE IS STARTING TO DECREASE...BUT IS STILL FAIRLY
DECENT OUT AHEAD OF THE BOW AT 2000 J/KG.
SHORT TERM GUIDANCE HAS BEEN VERY CONSISTENT THIS AFTERNOON/EARLY
EVENING WITH SHOWING AN INITIAL BAND OF MAINLY WEAK CONVECTION
DEVELOPING ALONG THE LEADING EDGE OF THE 925-850MB MOISTURE
TRANSPORT AND LIFTING NORTH THROUGH THE EVENING. THE MAIN QUESTION
IS WITH WHERE THE COMPLEX IN WESTERN IOWA WILL TRACK. WITH THE
925MB JET AND MOISTURE TRANSPORT INCREASING AND LIFTING NORTH
OVERNIGHT...THE SUPPORT IS THERE FOR ANY CONVECTION TO CONTINUE
TO TRACK EAST-NORTHEAST. FORWARD PROPAGATING CORFIDI VECTORS AND
0-3KM SHEAR IS ALL POINTING FROM THE SOUTHWEST TO THE NORTHEAST
AND THAT HAS BEEN BACKED BY THE INITIAL TRENDS WITH THE BOW.
CURRENT EXTRAPOLATION AND MESO-MODELS WOULD SAY THAT THE LEADING
EDGE OF THIS COMPLEX WOULD BE INTO THE CHARLES CITY IOWA AREA
AROUND OR SHORTLY AFTER MIDNIGHT...TO THE MISSISSIPPI RIVER IN NE
IA/SW WI AROUND 3AM...AND ON INTO SOUTH CENTRAL WISCONSIN BY 5AM.
THIS LINE OF STORMS HAS ALREADY PRODUCED 80MPH WIND GUSTS AT
OMAHA...BUT DO NOT EXPECT IT TO BE AT THAT STRENGTH...BUT STILL
POSSIBLY SEVERE...AS IT GETS INTO THE REGION. AM CONSIDERING CHANGING
THE FLOOD WATCH TO A FLASH FLOOD WATCH SINCE THERE APPEARS TO BE A
CHANCE THAT THIS COMPLEX SLOWS DOWN AND PRODUCES SOME HEAVY
RAINFALL OVER A SHORT PERIOD OVERNIGHT THAT IS TIED MORE TO
CONVECTION THAN A LONG LIVED MODERATE RAIN.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 325 PM CDT SUN MAY 11 2014
FOCUS OF THE FORECAST IS ON RAIN THROUGH TUESDAY.
REGIONAL RADARS SHOW A CONVECTIVE COMPLEX HAS SURVIVED FROM THE
OVERNIGHT HOURS AND CONTINUES TO TRANSLATE ACROSS SOUTHERN IOWA.
THAT HAS EFFECTIVELY PINNED THE WARM FRONT WELL SOUTH OF THE AREA
ALONG THE IOWA/MISSOURI BORDER. THIS HAS ALSO PINNED MOST OF THE
CAPE TO THE SOUTH WITH THE 19Z MU CAPE SHOWING LESS THAN 500 J/KG
ACROSS THE AREA. THE CONCERN BECOMES WHAT HAPPENS THIS EVENING AS
THE COMPLEX CONTINUES TO MOVE EAST AND IF THE WARM FRONT CAN MAKE
A MOVE NORTH. THE 11.17Z HRRR SUGGESTS THAT THE WARM FRONT WILL
START TO PUSH NORTH THIS EVENING BUT MAY STILL BE ONLY ABOUT AS
FAR NORTH AS THE INTERSTATE 80 CORRIDOR BY 03Z. THE WARM FRONT
COULD THEN GET PUSHED NORTHEAST THROUGH THE REST OF THE EVENING
AND NIGHT AS A STRONG SHORT WAVE TROUGH MOVES NORTHEAST ACROSS THE
REGION. THE 11.12Z NAM DOES SUGGEST BETWEEN 1000-1500 J/KG OF ML
CAPE WILL BE IN PLACE ALONG AND NEAR THE WARM FRONT...BUT IF THE
WARM FRONT GETS PUSHED NORTHEAST...THIS CAPE MAY JUST CLIP THE
SOUTHEAST PORTIONS OF THE AREA. HOWEVER...IF THIS SCENARIO DOES
NOT PLAY OUT AND THE CAPE IS FARTHER WEST...THERE WILL STILL BE A
SEVERE THREAT. THE 0-6KM SHEAR THIS EVENING SHOULD INCREASE TO A
RANGE OF 30 TO 50 KNOTS THIS EVENING THEN TO AROUND 60 KNOTS FOR
THE OVERNIGHT HOURS. THE NAM REMAINS CONSISTENT SHOWING 200-300
M2/S2 OF HELICITY OVER THE AREA IN THE 0-3KM LAYER WITH THE BULK
OF THE RESIDING THE 0-1KM LAYER. SO IF THE WARM FRONT CAN GET INTO
THE AREA...THERE WOULD STILL BE A THREAT FOR AN ISOLATED
TORNADO...BUT CONFIDENCE ON THE POSITION OF THE WARM FRONT IS NOT
VERY HIGH.
CONFIDENCE IS HIGH THAT IT WILL RAIN TONIGHT. THE MODELS HAVE BEEN
CONVERGING TOWARD THE SCENARIO THAT AS THE SHORT WAVE TROUGH
COMES OUT OF THE CENTRAL PLAINS AND MOVES NORTHEAST OVER THE
REGION TONIGHT THAT CONVECTION WILL FORM ALONG AN INVERTED TROUGH.
THIS TROUGH CURRENTLY EXTENDS FROM THE SOUTHWEST KANSAS ACROSS
WESTERN IOWA INTO WESTERN WISCONSIN. AS THE SHORT WAVE TROUGH
COMES OUT...MODERATE PV ADVECTION IN THE 500-300 MB LAYER IS
EXPECTED TO OCCUR. IN THE LOW LEVELS...THE WARM AIR ADVECTION WILL
INCREASE AHEAD OF THE WAVE WITH 5 TO 7 UBAR/S OF UP GLIDE ON THE
300K ISENTROPIC SURFACE WITH THE MOISTURE TRANSPORT ON THIS LEVEL
RIGHT INTO THE AREA. EXPECT TO SEE THE LINE OF CONVECTION DEVELOP
IN RESPONSE TO THIS WAVE FROM SOUTHERN MINNESOTA INTO KANSAS AND
THEN MOVE NORTHEAST ACROSS THE AREA THROUGH THE NIGHT. ONCE THE
SHORT WAVE TROUGH MOVES PAST...THE FORCING WILL SHIFT BACK TO THE
WEST AGAIN AHEAD OF THE MAIN LONG WAVE TROUGH AND THE EMBEDDED
SHORT WAVE TROUGH. THIS IS EXPECTED TO MAKE THE MAIN SURFACE LOW
MOVE FROM KANSAS INTO MINNESOTA OR WISCONSIN DURING THE DAY
MONDAY WITH THE COLD FRONT ADVANCING EAST INTO THE AREA. ANOTHER
ROUND OF VERY SIMILAR ISENTROPIC UP GLIDE AND MOISTURE TRANSPORT
IS EXPECTED ON THE 300K SURFACE FOR CONTINUED SHOWERS AND
THUNDERSTORMS AHEAD OF THE FRONT. EVERYTHING THEN STARTS TO
TRANSLATE EAST FOR MONDAY NIGHT WITH THE RAIN CHANCES ENDING FROM
WEST TO EAST THROUGH TUESDAY MORNING.
.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 325 PM CDT SUN MAY 11 2014
WILL CARRY SOME SMALL RAIN CHANCES FOR WEDNESDAY THROUGH FRIDAY
AND THEN SOME ON AND OFF CHANCES OVER THE WEEKEND. ONCE THE SYSTEM
FROM EARLY IN THE WEEK MOVES PAST...THE LONG WAVE TROUGH LOOKS TO
REMAIN OVER THE CENTRAL PART OF THE COUNTRY WITH A NORTHWEST FLOW
FROM NORTHWEST CANADA. THIS SHOULD ALLOW SEVERAL WEAK SHORT WAVE
TROUGHS TO ROTATE THROUGH THE LONG WAVE TROUGH TO SUPPORT THE RAIN
CHANCES. THIS FLOW WILL ALSO HELP TO KEEP TEMPERATURES BELOW
NORMAL WITH HIGHS IN THE 50S TO END THE WEEK AND THEN CREEPING
BACK INTO THE 60S FOR THE WEEKEND. OVERNIGHT LOWS WILL BE IN THE
30S AND MAY HAVE TO DEAL WITH SOME FROST HEADLINES TOWARD THE END
OF THE WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 638 PM CDT SUN MAY 11 2014
CONFIDENCE REMAINS HIGH THAT RAIN SHOWERS AND THUNDERSTORMS WILL
MOVE THROUGH THE REGION THIS EVENING AND OVERNIGHT WITH IFR
CONDITIONS LIKELY WITHIN THE THUNDERSTORM CLUSTERS. THE FIRST WAVE
OF SHOWERS AND STORMS ARE CURRENTLY MOVING NORTH ACROSS NORTHEAST
IOWA AND SHOULD BE INTO THE RST VICINITY AROUND 1Z AND LSE
VICINITY AROUND 3Z. THE MORE WIDESPREAD THUNDERSTORMS ARE EXPECTED
TO COME THROUGH LATE THIS EVENING AND OVERNIGHT BEFORE TRACKING TO
THE EAST BY DAYBREAK. A BREAK IS EXPECTED TO OCCUR WITH ANOTHER
ROUND OF STORMS EXPECTED TOMORROW AFTERNOON.
&&
.HYDROLOGY...
ISSUED AT 325 PM CDT SUN MAY 11 2014
RAINFALL FROM THIS SYSTEM THROUGH MONDAY SHOULD AVERAGE AROUND 2
INCHES FOR MUCH OF THE FORECAST AREA WITH LOCALIZED HIGHER AMOUNTS
EXPECTED. MANY OF THE RIVERS REMAIN HIGH FROM RECENT RUN OFFS AND
THE LATEST FORECASTS FROM THE RFC INDICATED WITHIN BANK RISES FOR
MANY OF THE TRIBUTARIES WITH RENEWED FLOODING POSSIBLE AT SOME
SPOTS ALONG THE MISSISSIPPI. IF THE RAINFALL ENDS UP BEING HIGHER
THAN THE QPF USED BY THE RFC...WHICH IS HIGH PROBABILITY...SOME
THE TRIBUTARIES COULD ALSO GO TO FLOOD. BASED ON THIS...HAVE OPTED
TO ISSUE A FLOOD WATCH FOR THE ENTIRE AREA FOR TONIGHT AND MONDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...FLASH FLOOD WATCH THROUGH LATE MONDAY NIGHT FOR WIZ017-029-
032>034-041>044-053>055-061.
MN...FLASH FLOOD WATCH THROUGH LATE MONDAY NIGHT FOR MNZ079-086>088-
094>096.
IA...FLASH FLOOD WATCH THROUGH LATE MONDAY NIGHT FOR IAZ008>011-018-
019-029-030.
&&
$$
UPDATE...HALBACH
SHORT TERM...04
LONG TERM...04
AVIATION...HALBACH
HYDROLOGY...04
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
936 PM CDT SUN MAY 11 2014
.UPDATE...
EXPECTED LULL OCCURRING AFTER LATE AFTERNOON/EARLY EVENING STRONG/SEVERE
CONVECTION. WATCHING WRN IOWA CONVECTION AS MODELS ARE TAKING THIS
COMPLEX AND LIFTING IT TO THE NNE ON LOW-LEVEL JET. THE BAND OF
BROKEN CONVECTION OVER SRN MN IN CONVERGENCE ZONE ON THE LEADING
EDGE OF THE STRONGER 850 MB WINDS...WHICH MODELS KEEP WEST OF SRN
WI FOR MOST OF THE OVERNIGHT. STILL CHANCES OF THUNDER INCREASE
AFTER MIDNIGHT AS LOW-LEVEL WINDS HEEL OVER TOWARD FORECAST
AREA...ESPECIALLY AFTER 09Z...THOUGH THEY DO WEAKEN. COULD SEE
SOME HEAVY RAIN TOTALS IN A SHORT AMOUNT OF TIME WITH ANY
OVERNIGHT CONVECTION WITH PRECIPITABLE WATER VALUES RISING FROM
1.2 TO 1.5 INCHES. WILL KEEP HIGHLIGHTED WORDING IN ZFP AND HWO
THOUGH LATEST NAM AND HRRR INDICATE BEST POTENTIAL FOR HEAVIEST
RAIN WILL BE NORTH AND WEST OF CWA.
&&
.AVIATION/06Z TAFS/...
WILL KEEP PREVIOUS TREND OF LOWERING CIGS WITH APPROACH OF WARM
FRONT THAT EARLIER CONVECTION HAS NOW PUSHED SOUTH INTO CENTRAL
IL...BUT SHOULD BEGIN A NORTHWARD TREK OVERNIGHT AS LOW PRESSURE
LIFTS UP THROUGH KS AND IA. WILL SEE A CONTINUED BREAK IN PCPN
UNTIL AFTER 06Z...AND POSSIBLY CLOSER TO 09Z...WHEN LOW-LEVEL JET
WINDS HEEL OVER TOWARD SRN WI. THEN ANOTHER BREAK WITH ONLY A FEW
SCATTERED SHOWERS UNTIL COLD FRONT PUSHES WEST TO EAST MONDAY
EVENING/OVERNIGHT. HAVE A CHANCE OF SEEING SEVERE STORMS ALONG
THIS LINE WITH GUSTY WINDS AND HAIL.
&&
.PREV DISCUSSION... /ISSUED 225 PM CDT SUN MAY 11 2014/
REST OF THIS AFTERNOON AND TONIGHT - CONFIDENCE...MEDIUM SPC MESO
PAGE CONTINUES TO SHOW DESTABILIZATION IN THE MID LEVELS WITH MUCAPE
INCREASING. ELEVATED HAIL PRODUCING STORMS WILL MOVE TAKING SHAPE
ACRS NE IA. LOW LEVELS ALSO DESTABLIZED. SSW WINDS HAVE BROUGHT 60
PLUS DEW POINT AIR INTO PARTS OF SC WI. HAIL AND HEAVY RAIN APPEAR
TO BE THE MAIN THREATS DUE TO FAVORABLE MID LEVEL LAPSE RATES AND
MOISTURE ADVECTION. 0-6KM SHEAR NOT THAT FAVORABLE. FOR LATER
TONIGHT...UPPER TROUGH AND PRIMARY SHORTWAVE ENERGY AT THE BASE OF
TROUGH WILL CONTINUE TO SHIFT EAST FROM THE ROCKIES. A LEAD
SHORTWAVE PICKED UP BY THE MODELS IS EXPECTED TO REACH NW WI BY 12Z.
SURFACE LOW WILL HEAD NORTHEAST AND BECOME SOMEWHAT ELONGATED FROM
MN THROUGH WRN IA. WIND FLOW WILL RESPOND AND INCREASE FROM THE
SOUTH. LOW LEVEL JET DOES TRANSLATE EASTWARD A BUT THOUGH PRIMARY
FORCING IS WEST. HOWEVER ENOUGH MOISTURE ADVECTION AND SPEED
CONVERGENCE TO SUPPORT TSRA ACRS THE CWA. HRRR SHOWING POTENTIAL MCS
ARRIVING AFTER 7Z OR SO INTO WRN CWA. 12Z NAM AND 12Z GFS DO FOCUS
THE STRONGEST CONVECTION CLOSER TO THE NOSE OF THE JET TO OUR
WEST...HOWEVER 12Z ECMWF/12Z GEM LEAN THE JET CLOSER TO SRN WI WITH
QPF PANELS RESPONDING WITH A MORE ORGANIZED CONVECTIVE COMPLEX
TAKING SHAPE. GIVEN THE SHORTWAVE RIDING NORTHEAST AND PLACEMENT OF
LLJ AXIS...WILL PLAY IT THAT MORE ORGANIZED CONVECTION RETURNS LATER
TONIGHT AFTER A BREAK BETWEEN THE AFTN/EARLY EVE STORMS.
MONDAY - CONFIDENCE...MEDIUM LEADING EDGE OF UPPER TROUGH DYNAMICS
PUSH INTO WRN IA AND WRN MN. STRONG SOUTHWEST UPPER FLOW ACRS SRN
WI. WARM SECTOR WILL BE WELL ENTRENCHED ACRS SRN WI. MODELS IN
GENERAL GREEMENT IN TAKING SURFACE LOW FROM MN TOWARDS NW WI.
WARM...MOIST AND UNSTABLE AIRMASS IN PLACE. THE UPPER JET WILL BE
WELL TO OUR WEST THOUGH MODELS HINTING AT SOME UPPER DIVERGENCE
HERE. BUFKIT SOUNDINGS SHOW DECENT MOISTURE WITH CAPES OVER 1000
J/KG. SO REAL EMPHASIS WILL BE ON THE TRIGGER. 4KM SPC WRF SHOWS
GENERAL WARM SECTOR/AIRMASS DEVELOPMENT WITH MAIN FOCUS FURTHER WEST
IN CLOSER PROXIMITY TO THE COLD FRONT. 925 TEMPS WILL BE AROUND
20C... SOME LAKE COOLING POSSIBLE BUT NOT EXPECTING MUCH OF AN
INLAND PUSH WITH THAT...SO EXPECT HIGHS WELL INTO THE 70S WITH A FEW
LOW 80S.
MONDAY NIGHT...FORECAST CONFIDENCE - MEDIUM.
RIGHT ENTRANCE REGION OF UPPER JET PASSES ACROSS SRN WI AS SFC CDFNT
MOVES ACROSS. PWAT VALUES WILL REMAIN IN THE 1.5 INCH RANGE AHEAD
OF THE FRONT WITH DEEP WARM CLOUD DEPTH AND MBE VELOCITY LESS THAN
10 KNOTS MOST OF THE NIGHT. 925-850MB MOISTURE FLUX CONVERGENCE
INCREASES ONCE AGAIN BUT DOES NOT REMAIN ORIENTATED WITH THE MEAN
STEERING FLOW. NEVER THE LESS...POTENTIAL FOR HEAVY RAINFALL WL
CONTINUE DURING THIS PD DUE TO STRONG FORCING AND DEEP MOISTURE.
TUESDAY THROUGH WEDNESDAY...FORECAST CONFIDENCE - HIGH.
SFC CDFNT WILL BE EXITING SOUTHEAST WISCONSIN EARLY TUESDAY MORNING.
LINGERING SHRA IN ITS WAKE SHOULD GRADUALLY DIMINISH FROM WEST TO
EAST AS COOLER...DRIER AIR SLOWLY WORKS ITS WAY ACROSS SRN WI AND
LOW LEVEL FRONTOGENETICAL FORCING SLIDES OFF TO THE EAST.
A QUIET AND COOL NIGHT IS EXPECTED TUESDAY NIGHT AS ANY INSTABILITY
-SHRA THAT WILL HAVE FORMED UPSTREAM IN THE AREA OF STEEP LOW TO MID
LEVEL LAPSE RATES SHOULD END WITH INSOLATION LOSS.
ON WEDNESDAY...MOST OF THE SHORT TERM GUIDANCE HINTING AT NEW SHORT
WAVE ROUNDING BASE OF LONG WAVE TROUGH OVER CENTRAL CONUS AND TAKING
NORTHEAST TRACK ALONG BAROCLINIC ZONE THROUGH TN AND OH VALLEY
REGION WED AND WED NGT. WL CONTINUE LOWER POPS FOR NOW WITH HIGHEST
IN THE SOUTHEAST WHERE PORTIONS OF SOUTHERN WI MAY BE ON THE
NORTHWEST SIDE OF THE EXPANDING PRECIP SHIELD WITH THIS SYSTEM.
WEDNESDAY NIGHT THROUGH SUNDAY...FORECAST CONFIDENCE - MEDIUM.
BROADSCALE AGREEMENT IN THE MEDIUM RANGE GUIDANCE ON COOLER AIR
SETTLING INTO THE REGION AND LINGERING THROUGH THE END OF THE WEEK.
THIS WILL BE DUE TO LINGERING LONG WAVE TROUGH OVER CENTRAL CONUS
WHICH WILL BE SPREADING SLOWLY EWD THROUGH THE END OF THE WEEK. EWD
PROGRESSION OF TROUGH WL BE SLOWED BY WESTERN ATLANTIC BLOCKING
RIDGE. MID-UPPER LEVEL RIDGE AXIS EXPCD TO PERSIST OVER WI THROUGH
FRI. SHORT WAVE TROUGH APPROACHING PACIFIC NW WILL FINALLY NUDGE
TROF TO THE EAST OF WI FOR THE WEEKEND.
HENCE THE COOLER THAN NORMAL TEMPERATURES THAT WILL HAVE SETTLED
OVER SRN WI BY WED ARE EXPECTED TO LINGER INTO THE WEEKEND BEFORE
GRADUALLY WARMING. 85H TEMPS WL HAVE COOLED TO AROUND 0C BY WED AND
WL REMAIN A FEW DEGREES WITH 0C INTO SAT. IN ADDITION...WEAKER
SHORT WAVES ROTATING AROUND PARENT LONG WAVE TROUGH MAY BRING SOME
-SHRA TO SRN WI FROM WED THROUGH FRI. LAST SEVERAL RUNS OF THE
ECMWF HAVE BEEN SHOWING MORE POTENT LOW PRESSURE MOVING NORTHWARD
THROUGH TN/OH VALLEYS WED NGT INTO THU...WITH THE POTENTIAL FOR
PORTIONS OF SRN WI ON THE NORTHWEST WIDE OF THE -RA SHIELD FROM THIS
SYSTEM. CANADIAN AND GFS SHOW WEAKER RIPPLE AND ECMWF ENSEMBLE
FLATTENS THIS STRONGER SYSTEM AS WELL. HENCE FOR NOW WL CONTINUE
LOWER POPS FOR -SHRA WED NIGHT INTO THU.
EXPECTING MORE CLOUDS AND WEAK BOUNDARY LAYER MIXING TO KEEP
OVERNIGHT TEMPERATURES IN THE MIDDLE 30S TO LOWER 40S THURSDAY NIGHT
AND AGAIN FRIDAY NIGHT. HOWEVER IF MORE CLEARING IS EXPECTED IN
THESE PERIODS IN LATER FORECAST PERIODS...WL NEED TO CONSIDER ADDING
FROST TO THE LATE NIGHT FORECASTS.
AVIATION/12Z TAFS/...HRRR AND 4KM SPC WRF SHOW SOME ELEVATED STORMS
INTO SRN WI THIS AFTN/EVE WHICH LOOKS RIGHT ON GIVEN TRENDS IN 88-D.
LOOKING AT A BREAK A BIT LATER THIS EVE BEFORE POTENTIAL MCS ARRIVES
AFTER MIDNIGHT. THREAT THIS EVE LOOKS TO BE HAIL WITH DECENT MID
LEVEL LAPSE RATES. MORE DEVELOPMENT LIKELY TONIGHT AS LLJ REFOCUSES
TO OUR WEST AND THE LOW TO OUR WEST STRENGTHENS. NAM/GFS KEYING ON
IA/SE MN/ CNTRL/NRN WI THOUGH 12Z ECMWF/GEM AND HRRR SUGGEST STORMS
FOCUSED MORE INTO SRN WI. POTENTIAL FOR MORE SHRA/TSRA ON MONDAY
WITH WARM/HUMID/UNSTABLE AIRMASS THOUGH COLD FRONT STILL BACK TO OUR
WEST AND NOT EXPECTED TO ARRIVE UNTIL MONDAY NIGHT.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...REM
TONIGHT/MONDAY AND AVIATION/MARINE...COLLAR
MONDAY NIGHT THROUGH SUNDAY...MRC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
855 PM CDT SUN MAY 11 2014
.UPDATE...
ISSUED AT 855 PM CDT SUN MAY 11 2014
THE MAIN FOCUS WITH THE FORECAST IS WITH THE SEVERE WEATHER
POTENTIAL OVERNIGHT. CURRENT SURFACE ANALYSIS SHOWS A LOW PRESSURE
SYSTEM CENTERED NEAR OMAHA WHERE A BOWING COMPLEX HAS EMERGED FROM
A LONG TRACK HP SUPERCELL THAT TRACKED ACROSS SOUTHEAST NEBRASKA
THIS AFTERNOON. THE MAIN SURFACE WARM FRONT APPEARS TO EXTEND EAST
FROM OMAHA ACROSS SOUTHERN IOWA WITH AN INVERTED TROUGH EXTENDING
NORTH FROM THE LOW INTO SOUTHWEST MINNESOTA. ANOTHER DEW POINT
GRADIENT EXISTS ALONG THE MINNESOTA/IOWA BORDER WHERE DEW POINTS
GO FROM THE MID 50S IN SOUTHEAST MINNESOTA TO THE LOW 60S IN
NORTHEAST IOWA. 12.00Z RAP ANALYSIS SUGGESTS THAT THERE STILL IS
QUITE A BIT OF INSTABILITY AHEAD OF THIS COMPLEX RUNNING EAST
ACROSS IOWA WITH 0-3KM MUCAPE AROUND 2000 J/KG FROM DES MOINES
EAST AND AROUND 1000 J/KG RUNNING ALONG THE MINNESOTA/IOWA BORDER.
SURFACE BASED CAPE IS STARTING TO DECREASE...BUT IS STILL FAIRLY
DECENT OUT AHEAD OF THE BOW AT 2000 J/KG.
SHORT TERM GUIDANCE HAS BEEN VERY CONSISTENT THIS AFTERNOON/EARLY
EVENING WITH SHOWING AN INITIAL BAND OF MAINLY WEAK CONVECTION
DEVELOPING ALONG THE LEADING EDGE OF THE 925-850MB MOISTURE
TRANSPORT AND LIFTING NORTH THROUGH THE EVENING. THE MAIN QUESTION
IS WITH WHERE THE COMPLEX IN WESTERN IOWA WILL TRACK. WITH THE
925MB JET AND MOISTURE TRANSPORT INCREASING AND LIFTING NORTH
OVERNIGHT...THE SUPPORT IS THERE FOR ANY CONVECTION TO CONTINUE
TO TRACK EAST-NORTHEAST. FORWARD PROPAGATING CORFIDI VECTORS AND
0-3KM SHEAR IS ALL POINTING FROM THE SOUTHWEST TO THE NORTHEAST
AND THAT HAS BEEN BACKED BY THE INITIAL TRENDS WITH THE BOW.
CURRENT EXTRAPOLATION AND MESO-MODELS WOULD SAY THAT THE LEADING
EDGE OF THIS COMPLEX WOULD BE INTO THE CHARLES CITY IOWA AREA
AROUND OR SHORTLY AFTER MIDNIGHT...TO THE MISSISSIPPI RIVER IN NE
IA/SW WI AROUND 3AM...AND ON INTO SOUTH CENTRAL WISCONSIN BY 5AM.
THIS LINE OF STORMS HAS ALREADY PRODUCED 80MPH WIND GUSTS AT
OMAHA...BUT DO NOT EXPECT IT TO BE AT THAT STRENGTH...BUT STILL
POSSIBLY SEVERE...AS IT GETS INTO THE REGION. AM CONSIDERING CHANGING
THE FLOOD WATCH TO A FLASH FLOOD WATCH SINCE THERE APPEARS TO BE A
CHANCE THAT THIS COMPLEX SLOWS DOWN AND PRODUCES SOME HEAVY
RAINFALL OVER A SHORT PERIOD OVERNIGHT THAT IS TIED MORE TO
CONVECTION THAN A LONG LIVED MODERATE RAIN.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 325 PM CDT SUN MAY 11 2014
FOCUS OF THE FORECAST IS ON RAIN THROUGH TUESDAY.
REGIONAL RADARS SHOW A CONVECTIVE COMPLEX HAS SURVIVED FROM THE
OVERNIGHT HOURS AND CONTINUES TO TRANSLATE ACROSS SOUTHERN IOWA.
THAT HAS EFFECTIVELY PINNED THE WARM FRONT WELL SOUTH OF THE AREA
ALONG THE IOWA/MISSOURI BORDER. THIS HAS ALSO PINNED MOST OF THE
CAPE TO THE SOUTH WITH THE 19Z MU CAPE SHOWING LESS THAN 500 J/KG
ACROSS THE AREA. THE CONCERN BECOMES WHAT HAPPENS THIS EVENING AS
THE COMPLEX CONTINUES TO MOVE EAST AND IF THE WARM FRONT CAN MAKE
A MOVE NORTH. THE 11.17Z HRRR SUGGESTS THAT THE WARM FRONT WILL
START TO PUSH NORTH THIS EVENING BUT MAY STILL BE ONLY ABOUT AS
FAR NORTH AS THE INTERSTATE 80 CORRIDOR BY 03Z. THE WARM FRONT
COULD THEN GET PUSHED NORTHEAST THROUGH THE REST OF THE EVENING
AND NIGHT AS A STRONG SHORT WAVE TROUGH MOVES NORTHEAST ACROSS THE
REGION. THE 11.12Z NAM DOES SUGGEST BETWEEN 1000-1500 J/KG OF ML
CAPE WILL BE IN PLACE ALONG AND NEAR THE WARM FRONT...BUT IF THE
WARM FRONT GETS PUSHED NORTHEAST...THIS CAPE MAY JUST CLIP THE
SOUTHEAST PORTIONS OF THE AREA. HOWEVER...IF THIS SCENARIO DOES
NOT PLAY OUT AND THE CAPE IS FARTHER WEST...THERE WILL STILL BE A
SEVERE THREAT. THE 0-6KM SHEAR THIS EVENING SHOULD INCREASE TO A
RANGE OF 30 TO 50 KNOTS THIS EVENING THEN TO AROUND 60 KNOTS FOR
THE OVERNIGHT HOURS. THE NAM REMAINS CONSISTENT SHOWING 200-300
M2/S2 OF HELICITY OVER THE AREA IN THE 0-3KM LAYER WITH THE BULK
OF THE RESIDING THE 0-1KM LAYER. SO IF THE WARM FRONT CAN GET INTO
THE AREA...THERE WOULD STILL BE A THREAT FOR AN ISOLATED
TORNADO...BUT CONFIDENCE ON THE POSITION OF THE WARM FRONT IS NOT
VERY HIGH.
CONFIDENCE IS HIGH THAT IT WILL RAIN TONIGHT. THE MODELS HAVE BEEN
CONVERGING TOWARD THE SCENARIO THAT AS THE SHORT WAVE TROUGH
COMES OUT OF THE CENTRAL PLAINS AND MOVES NORTHEAST OVER THE
REGION TONIGHT THAT CONVECTION WILL FORM ALONG AN INVERTED TROUGH.
THIS TROUGH CURRENTLY EXTENDS FROM THE SOUTHWEST KANSAS ACROSS
WESTERN IOWA INTO WESTERN WISCONSIN. AS THE SHORT WAVE TROUGH
COMES OUT...MODERATE PV ADVECTION IN THE 500-300 MB LAYER IS
EXPECTED TO OCCUR. IN THE LOW LEVELS...THE WARM AIR ADVECTION WILL
INCREASE AHEAD OF THE WAVE WITH 5 TO 7 UBAR/S OF UP GLIDE ON THE
300K ISENTROPIC SURFACE WITH THE MOISTURE TRANSPORT ON THIS LEVEL
RIGHT INTO THE AREA. EXPECT TO SEE THE LINE OF CONVECTION DEVELOP
IN RESPONSE TO THIS WAVE FROM SOUTHERN MINNESOTA INTO KANSAS AND
THEN MOVE NORTHEAST ACROSS THE AREA THROUGH THE NIGHT. ONCE THE
SHORT WAVE TROUGH MOVES PAST...THE FORCING WILL SHIFT BACK TO THE
WEST AGAIN AHEAD OF THE MAIN LONG WAVE TROUGH AND THE EMBEDDED
SHORT WAVE TROUGH. THIS IS EXPECTED TO MAKE THE MAIN SURFACE LOW
MOVE FROM KANSAS INTO MINNESOTA OR WISCONSIN DURING THE DAY
MONDAY WITH THE COLD FRONT ADVANCING EAST INTO THE AREA. ANOTHER
ROUND OF VERY SIMILAR ISENTROPIC UP GLIDE AND MOISTURE TRANSPORT
IS EXPECTED ON THE 300K SURFACE FOR CONTINUED SHOWERS AND
THUNDERSTORMS AHEAD OF THE FRONT. EVERYTHING THEN STARTS TO
TRANSLATE EAST FOR MONDAY NIGHT WITH THE RAIN CHANCES ENDING FROM
WEST TO EAST THROUGH TUESDAY MORNING.
.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 325 PM CDT SUN MAY 11 2014
WILL CARRY SOME SMALL RAIN CHANCES FOR WEDNESDAY THROUGH FRIDAY
AND THEN SOME ON AND OFF CHANCES OVER THE WEEKEND. ONCE THE SYSTEM
FROM EARLY IN THE WEEK MOVES PAST...THE LONG WAVE TROUGH LOOKS TO
REMAIN OVER THE CENTRAL PART OF THE COUNTRY WITH A NORTHWEST FLOW
FROM NORTHWEST CANADA. THIS SHOULD ALLOW SEVERAL WEAK SHORT WAVE
TROUGHS TO ROTATE THROUGH THE LONG WAVE TROUGH TO SUPPORT THE RAIN
CHANCES. THIS FLOW WILL ALSO HELP TO KEEP TEMPERATURES BELOW
NORMAL WITH HIGHS IN THE 50S TO END THE WEEK AND THEN CREEPING
BACK INTO THE 60S FOR THE WEEKEND. OVERNIGHT LOWS WILL BE IN THE
30S AND MAY HAVE TO DEAL WITH SOME FROST HEADLINES TOWARD THE END
OF THE WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 638 PM CDT SUN MAY 11 2014
CONFIDENCE REMAINS HIGH THAT RAIN SHOWERS AND THUNDERSTORMS WILL
MOVE THROUGH THE REGION THIS EVENING AND OVERNIGHT WITH IFR
CONDITIONS LIKELY WITHIN THE THUNDERSTORM CLUSTERS. THE FIRST WAVE
OF SHOWERS AND STORMS ARE CURRENTLY MOVING NORTH ACROSS NORTHEAST
IOWA AND SHOULD BE INTO THE RST VICINITY AROUND 1Z AND LSE
VICINITY AROUND 3Z. THE MORE WIDESPREAD THUNDERSTORMS ARE EXPECTED
TO COME THROUGH LATE THIS EVENING AND OVERNIGHT BEFORE TRACKING TO
THE EAST BY DAYBREAK. A BREAK IS EXPECTED TO OCCUR WITH ANOTHER
ROUND OF STORMS EXPECTED TOMORROW AFTERNOON.
&&
.HYDROLOGY...
ISSUED AT 325 PM CDT SUN MAY 11 2014
RAINFALL FROM THIS SYSTEM THROUGH MONDAY SHOULD AVERAGE AROUND 2
INCHES FOR MUCH OF THE FORECAST AREA WITH LOCALIZED HIGHER AMOUNTS
EXPECTED. MANY OF THE RIVERS REMAIN HIGH FROM RECENT RUN OFFS AND
THE LATEST FORECASTS FROM THE RFC INDICATED WITHIN BANK RISES FOR
MANY OF THE TRIBUTARIES WITH RENEWED FLOODING POSSIBLE AT SOME
SPOTS ALONG THE MISSISSIPPI. IF THE RAINFALL ENDS UP BEING HIGHER
THAN THE QPF USED BY THE RFC...WHICH IS HIGH PROBABILITY...SOME
THE TRIBUTARIES COULD ALSO GO TO FLOOD. BASED ON THIS...HAVE OPTED
TO ISSUE A FLOOD WATCH FOR THE ENTIRE AREA FOR TONIGHT AND MONDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...FLOOD WATCH THROUGH MONDAY EVENING FOR WIZ017-029-032>034-
041>044-053>055-061.
MN...FLOOD WATCH THROUGH MONDAY EVENING FOR MNZ079-086>088-094>096.
IA...FLOOD WATCH THROUGH MONDAY EVENING FOR IAZ008>011-018-019-029-
030.
&&
$$
UPDATE...HALBACH
SHORT TERM...04
LONG TERM...04
AVIATION...HALBACH
HYDROLOGY...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
638 PM CDT SUN MAY 11 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 325 PM CDT SUN MAY 11 2014
FOCUS OF THE FORECAST IS ON RAIN THROUGH TUESDAY.
REGIONAL RADARS SHOW A CONVECTIVE COMPLEX HAS SURVIVED FROM THE
OVERNIGHT HOURS AND CONTINUES TO TRANSLATE ACROSS SOUTHERN IOWA.
THAT HAS EFFECTIVELY PINNED THE WARM FRONT WELL SOUTH OF THE AREA
ALONG THE IOWA/MISSOURI BORDER. THIS HAS ALSO PINNED MOST OF THE
CAPE TO THE SOUTH WITH THE 19Z MU CAPE SHOWING LESS THAN 500 J/KG
ACROSS THE AREA. THE CONCERN BECOMES WHAT HAPPENS THIS EVENING AS
THE COMPLEX CONTINUES TO MOVE EAST AND IF THE WARM FRONT CAN MAKE
A MOVE NORTH. THE 11.17Z HRRR SUGGESTS THAT THE WARM FRONT WILL
START TO PUSH NORTH THIS EVENING BUT MAY STILL BE ONLY ABOUT AS
FAR NORTH AS THE INTERSTATE 80 CORRIDOR BY 03Z. THE WARM FRONT
COULD THEN GET PUSHED NORTHEAST THROUGH THE REST OF THE EVENING
AND NIGHT AS A STRONG SHORT WAVE TROUGH MOVES NORTHEAST ACROSS THE
REGION. THE 11.12Z NAM DOES SUGGEST BETWEEN 1000-1500 J/KG OF ML
CAPE WILL BE IN PLACE ALONG AND NEAR THE WARM FRONT...BUT IF THE
WARM FRONT GETS PUSHED NORTHEAST...THIS CAPE MAY JUST CLIP THE
SOUTHEAST PORTIONS OF THE AREA. HOWEVER...IF THIS SCENARIO DOES
NOT PLAY OUT AND THE CAPE IS FARTHER WEST...THERE WILL STILL BE A
SEVERE THREAT. THE 0-6KM SHEAR THIS EVENING SHOULD INCREASE TO A
RANGE OF 30 TO 50 KNOTS THIS EVENING THEN TO AROUND 60 KNOTS FOR
THE OVERNIGHT HOURS. THE NAM REMAINS CONSISTENT SHOWING 200-300
M2/S2 OF HELICITY OVER THE AREA IN THE 0-3KM LAYER WITH THE BULK
OF THE RESIDING THE 0-1KM LAYER. SO IF THE WARM FRONT CAN GET INTO
THE AREA...THERE WOULD STILL BE A THREAT FOR AN ISOLATED
TORNADO...BUT CONFIDENCE ON THE POSITION OF THE WARM FRONT IS NOT
VERY HIGH.
CONFIDENCE IS HIGH THAT IT WILL RAIN TONIGHT. THE MODELS HAVE BEEN
CONVERGING TOWARD THE SCENARIO THAT AS THE SHORT WAVE TROUGH
COMES OUT OF THE CENTRAL PLAINS AND MOVES NORTHEAST OVER THE
REGION TONIGHT THAT CONVECTION WILL FORM ALONG AN INVERTED TROUGH.
THIS TROUGH CURRENTLY EXTENDS FROM THE SOUTHWEST KANSAS ACROSS
WESTERN IOWA INTO WESTERN WISCONSIN. AS THE SHORT WAVE TROUGH
COMES OUT...MODERATE PV ADVECTION IN THE 500-300 MB LAYER IS
EXPECTED TO OCCUR. IN THE LOW LEVELS...THE WARM AIR ADVECTION WILL
INCREASE AHEAD OF THE WAVE WITH 5 TO 7 UBAR/S OF UP GLIDE ON THE
300K ISENTROPIC SURFACE WITH THE MOISTURE TRANSPORT ON THIS LEVEL
RIGHT INTO THE AREA. EXPECT TO SEE THE LINE OF CONVECTION DEVELOP
IN RESPONSE TO THIS WAVE FROM SOUTHERN MINNESOTA INTO KANSAS AND
THEN MOVE NORTHEAST ACROSS THE AREA THROUGH THE NIGHT. ONCE THE
SHORT WAVE TROUGH MOVES PAST...THE FORCING WILL SHIFT BACK TO THE
WEST AGAIN AHEAD OF THE MAIN LONG WAVE TROUGH AND THE EMBEDDED
SHORT WAVE TROUGH. THIS IS EXPECTED TO MAKE THE MAIN SURFACE LOW
MOVE FROM KANSAS INTO MINNESOTA OR WISCONSIN DURING THE DAY
MONDAY WITH THE COLD FRONT ADVANCING EAST INTO THE AREA. ANOTHER
ROUND OF VERY SIMILAR ISENTROPIC UP GLIDE AND MOISTURE TRANSPORT
IS EXPECTED ON THE 300K SURFACE FOR CONTINUED SHOWERS AND
THUNDERSTORMS AHEAD OF THE FRONT. EVERYTHING THEN STARTS TO
TRANSLATE EAST FOR MONDAY NIGHT WITH THE RAIN CHANCES ENDING FROM
WEST TO EAST THROUGH TUESDAY MORNING.
.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 325 PM CDT SUN MAY 11 2014
WILL CARRY SOME SMALL RAIN CHANCES FOR WEDNESDAY THROUGH FRIDAY
AND THEN SOME ON AND OFF CHANCES OVER THE WEEKEND. ONCE THE SYSTEM
FROM EARLY IN THE WEEK MOVES PAST...THE LONG WAVE TROUGH LOOKS TO
REMAIN OVER THE CENTRAL PART OF THE COUNTRY WITH A NORTHWEST FLOW
FROM NORTHWEST CANADA. THIS SHOULD ALLOW SEVERAL WEAK SHORT WAVE
TROUGHS TO ROTATE THROUGH THE LONG WAVE TROUGH TO SUPPORT THE RAIN
CHANCES. THIS FLOW WILL ALSO HELP TO KEEP TEMPERATURES BELOW
NORMAL WITH HIGHS IN THE 50S TO END THE WEEK AND THEN CREEPING
BACK INTO THE 60S FOR THE WEEKEND. OVERNIGHT LOWS WILL BE IN THE
30S AND MAY HAVE TO DEAL WITH SOME FROST HEADLINES TOWARD THE END
OF THE WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 638 PM CDT SUN MAY 11 2014
CONFIDENCE REMAINS HIGH THAT RAIN SHOWERS AND THUNDERSTORMS WILL
MOVE THROUGH THE REGION THIS EVENING AND OVERNIGHT WITH IFR
CONDITIONS LIKELY WITHIN THE THUNDERSTORM CLUSTERS. THE FIRST WAVE
OF SHOWERS AND STORMS ARE CURRENTLY MOVING NORTH ACROSS NORTHEAST
IOWA AND SHOULD BE INTO THE RST VICINITY AROUND 1Z AND LSE
VICINITY AROUND 3Z. THE MORE WIDESPREAD THUNDERSTORMS ARE EXPECTED
TO COME THROUGH LATE THIS EVENING AND OVERNIGHT BEFORE TRACKING TO
THE EAST BY DAYBREAK. A BREAK IS EXPECTED TO OCCUR WITH ANOTHER
ROUND OF STORMS EXPECTED TOMORROW AFTERNOON.
&&
.HYDROLOGY...
ISSUED AT 325 PM CDT SUN MAY 11 2014
RAINFALL FROM THIS SYSTEM THROUGH MONDAY SHOULD AVERAGE AROUND 2
INCHES FOR MUCH OF THE FORECAST AREA WITH LOCALIZED HIGHER AMOUNTS
EXPECTED. MANY OF THE RIVERS REMAIN HIGH FROM RECENT RUN OFFS AND
THE LATEST FORECASTS FROM THE RFC INDICATED WITHIN BANK RISES FOR
MANY OF THE TRIBUTARIES WITH RENEWED FLOODING POSSIBLE AT SOME
SPOTS ALONG THE MISSISSIPPI. IF THE RAINFALL ENDS UP BEING HIGHER
THAN THE QPF USED BY THE RFC...WHICH IS HIGH PROBABILITY...SOME
THE TRIBUTARIES COULD ALSO GO TO FLOOD. BASED ON THIS...HAVE OPTED
TO ISSUE A FLOOD WATCH FOR THE ENTIRE AREA FOR TONIGHT AND MONDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...FLOOD WATCH THROUGH MONDAY EVENING FOR WIZ017-029-032>034-
041>044-053>055-061.
MN...FLOOD WATCH THROUGH MONDAY EVENING FOR MNZ079-086>088-094>096.
IA...FLOOD WATCH THROUGH MONDAY EVENING FOR IAZ008>011-018-019-029-
030.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...HALBACH
HYDROLOGY...04
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND SUNDAY
ISSUED AT 324 PM CDT SAT MAY 10 2014
CONCERN ON PCPN CHANCES TONIGHT INTO SUNDAY.
HIGH PRESSURE OVER STATE...LEADING TO DEEP MIXING AND DEW POINTS
IN THE LOWER 20S IN SOME OF OUR DRIER SPOTS. MORNING SOUNDINGS MSP
AND GRB SHOWING THIS DRY AIR. AREA OF CLOUDS/SHOWERS WITH SHORT
WAVE HAVING HARD TIME MOVING NORTH. HRRR SHOWS THE AREA DRYING UP
AS MOVES INTO SOUTHWEST WI. HAVE BACKED OFF ON CLOUDS/POPS THROUGH EARLY
EVENING HOURS.
SHORT WAVE TO WEAKEN AS IT LIFTS NORTH TO THE WEST OF STATE.
MODELS TRENDS HAVE BEEN WEST WITH PCPN WITH LOW LEVEL FLOW FOCUSED
INTO SOUTHERN MN...SHIFTING SOUTHWEST INTO WESTERN WI LATE. HAVE
BACKED OFF ON EASTWARD PROGRESSION WITH POPS...THINKING BEST POPS
NORTH LATE TONIGHT WITH 850 FRONT LIFTING INTO THE AREA.
PCPN WITH THE LEAD WAVE EXPECTED TO EXIT THE N DURING THE MORNING...THEN
EXPECT A LULL FOR THE MUCH OF THE DAY. MADE LITTLE CHANGE TO
PREVIOUS FORECAST FOR TEMPS/AFTN POPS.
.LONG TERM...SUNDAY NIGHT THROUGH SATURDAY
ISSUED AT 324 PM CDT SAT MAY 10 2014
MAIN CONCERN WILL BE THE SYSTEM SUNDAY NIGHT INTO TUESDAY MORNING.
LOW LEVEL JET IS EXPECTED TO INCREASE TO 50 TO 60 KTS SUNDAY NIGHT.
MID LEVEL LAPSE RATES WERE NEAR 6 C/KM. THERE IS CONSIDERABLE CONCERN
WHERE AXIS OF HEAVY RAIN WILL SET UP. BASED ON POSITION OF THE
SURFACE WARM FRONT...WRF MODEL TOO FAR NORTH WHILE THE GFS IS FURTHER
SOUTH COMPARED TO THE CANADIAN/ECMWF. IF GFS IS CORRECT...THE
HEAVY RAIN SUNDAY NIGHT WOULD BE SOUTH OF OUR AREA AND THE WARM
FRONT WILL BE NO WHERE CLOSE TO OUR FORECAST AREA AS OUTFLOW
BOUNDARIES SHOULD SHOVE THE FRONT SOUTH. IF THE ECMWF/CANADIAN
ARE CORRECT...OUR SOUTHERN FORECAST AREA WILL BE ON THE NORTHERN
EDGE OF THE HEAVY RAIN. MAIN CONCERN FOR LATER SUNDAY NIGHT WILL
BE THE POTENTIAL FOR HEAVY RAIN AND SMALL HAIL.
EITHER WAY...SURFACE WARM FRONT WILL BE SOUTH OF OUR AREA ON
MONDAY. ONGOING CONVECTION/OUTFLOW BOUNDARIES FROM OVERNIGHT
CONVECTION THAT LINGERS INTO MONDAY MORNING WILL SLOW THE NORTHWARD
PROGRESS OF THE WARM FRONT. THE SEVERE POTENTIAL REMAINS UNCERTAIN
FOR THESE REASONS. IF WE DO GET SOME CLEARING ACROSS THE SOUTH
ON MONDAY...SOME OF THE STORMS COULD BECOME STRONG OR SEVERE...
ESPECIALLY SOUTH OF HIGHWAY 29. A SECONDARY WAVE IS EXPECTED TO
MOVE ALONG THE FRONT MONDAY NIGHT INTO TUESDAY MORNING...BRINGING
MORE LOCALLY HEAVY RAIN. RAINFALL TOTALS OF 1 TO 2 INCHES ARE
EXPECTED ACROSS MUCH OF THE AREA...WITH LOCALLY HIGHER AMOUNTS
ACROSS THE SOUTH.
HIGH PRESSURE BUILDS INTO THE REGION TUESDAY NIGHT. COOL CYCLONIC
FLOW EXPECTED FOR THE REMAINDER OF THE WORK WEEK...BRINGING A
CHANCE FOR INSTABILITY SHOWERS WEDNESDAY THROUGH FRIDAY. THE
GREATEST CONCENTRATION OF SHOWERS WILL BE DURING THE AFTERNOON
AND EARLY EVENING HOURS. CAN NOT RULE OUT ISOLATED/SCATTERED
SHOWERS OUTSIDE THIS PERIOD EACH DAY DUE TO WEAK DISTURBANCES
MOVING WITH THE MEAN FLOW.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1201 PM CDT SAT MAY 10 2014
MAINLY VFR CONDITIONS EXPECTED THROUGHOUT THE TAF PERIOD. MODELS
TRENDING WEST AND NORTH WITH PCPN TONIGHT...WHICH IN TURN HAS TO
DEAL WITH RATHER DRY AIRMASS TODAY. PCPN THAT DEVELOPS TNGT SHOULD BE
PRIMARY OUT OF A MIDDLE CLOUD DECK... THOUGH COULD GET SOME BRIEF
MVFR CIGS WITH ANY HEAVIER SHOWERS MAINLY NORTH CENTRAL.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....TE
LONG TERM......ECKBERG
AVIATION.......TE
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
310 PM CDT SAT MAY 10 2014
.SHORT TERM...(TONIGHT THROUGH SUNDAY NIGHT)
ISSUED AT 310 PM CDT SAT MAY 10 2014
MAIN FORECAST CONCERNS THIS PERIOD...SHRA/TSRA CHANCES THIS EVENING
AND AGAIN SUN AFTERNOON/NIGHT. POTENTIAL HEAVY RAINS SUN NIGHT.
18Z DATA ANALYSIS HAD A WEAK RIDGE OF HIGH PRESSURE FROM NORTHEAST
MN THRU SOUTHEAST WI. SUNNY...QUIET DAY OVER THE NORTHEAST HALF OF
THE REGION. WV IMAGERY SHOWED A MORE ROBUST LOOKING SHORTWAVE
LIFTING NORTHEAST ACROSS SD/NEB EARLY THIS AFTERNOON. THIS WAVE AND
SOME 850-700MB MOISTURE TRANSPORT/THERMO-DYNAMIC FORCING RESPONSIBLE
FOR A BROAD BAND OF SCT SHRA/ISOLATED TSRA LIFTING ACROSS NORTHERN
IA/SOUTHWEST MN. PER 10.12Z KMPX SOUNDING...PLENTY OF DRY AIR ABOVE
850MB AHEAD OF THIS BAND OF SHRA/TSRA TO OVERCOME BEFORE PRECIP
REACHES THE GROUND...AND MOST RAIN AMOUNTS SO FAR TODAY HAVE BEEN A
TRACE TO A FEW HUNDREDTHS OF AN INCH.
10.12Z MODELS INITIALIZED WELL...BUT FOR GFS ABOUT 5F HIGH ON SFC
DEW POINTS ACROSS THE SOUTH HALF OF THE UPPER MS VALLEY.
SOLUTIONS CONTINUE TO OFFER A TIGHTER CONSENSUS ON THE SHORTWAVE
TO LIFT ACROSS THE UPPER MIDWEST TONIGHT AND THE NEXT STRONG
TROUGHING/ ENERGY TO CROSS THE ROCKIES SUN/SUN NIGHT.
SLOWER/STRONGER ECMWF/ CAN-GEM OFFERING THE BETTER RUN-TO-RUN
CONSISTENCY WITH THE ROCKIES TROUGHING LATE SUN/SUN NIGHT WITH
GFS/NAM SLOWING TO MATCH UP. NAM APPEARS AS BIT OF AN OUTLIER AT
12Z MON WITH A FURTHER NORTH/EAST SFC LOW/TRAILING COLD FRONT AND
ITS SOLUTION GENERALLY DISCOUNTED. GIVEN THE NOW RATHER TIGHT NON-
NAM CONSENSUS THRU 12Z MON...SHORT- TERM FCST CONFIDENCE FOR A
RATHER ACTIVE PERIOD IS GOOD THIS CYCLE.
FIRST SHORTWAVE CROSSING THE UPPER MIDWEST TONIGHT WEAKENS AS
LOOSES THE BATTLE WITH THE RISING HGTS/RIDGING AHEAD OF THE
STRONGER TROUGHING DIGGING INTO THE ROCKIES. 925-700MB MOISTURE
TRANSPORT/ WARM ADVECTION AND SOME 295-305K ISENTROPIC LIFT STILL
SPREADS NORTHEAST ACROSS THE FCST AREA MAINLY LATE THIS
AFTERNOON/EVENING... WITH STEEPER MID LEVEL LAPSE RATES AND WEAK
INSTABILITY. WILL CONTINUE SHRA/TSRA CHANCES THRU THE EVENING...IN
THE 20-50 PERCENT RANGE...THEN TAPER/END THEM AFTER MIDNIGHT AS
THE LOWER LEVEL FORCING WEAKENS/MOVES EAST OF THE FCST AREA. MOST
RAIN AMOUNTS TONIGHT TO BE QUITE LIGHT.
BREAK FROM THE RAIN CHANCES LATE TONIGHT/SUN MORNING AS SOME 850-
700MB DRYING TEMPORARILY SPREADS ACROSS THE AREA. MOISTURE RETURN
AHEAD OF THE CENTRAL PLAINS LEE LOW ALREADY SPREAD ACROSS THE AREA
SUN MORNING...WITH THE 700MB MOISTURE ARRIVING DURING THE LATER
MORNING/EARLY AFTERNOON HOURS AND 925-50MB MOISTURE ARRIVING DURING
THE AFTERNOON. PW VALUES OF AROUND 1.5 INCHES TO SPREAD NORTH ACROSS
THE AREA FOR SUN AFTERNOON/NIGHT. QUESTION NO LONGER SEEMS IF ITS
GOING TO RAIN LATE SUN AFTERNOON/NIGHT BUT HOW MUCH. BROAD/DEEP
LAYERED FORCING/LIFT AHEAD OF THE SFC THRU MID LEVEL TROUGH SPREADS
ACROSS WITH THE MOISTURE INCREASE SUN AFTERNOON/NIGHT.
AT 00Z MON...MODEL SOUNDINGS SHOWING STABILITY/CIN OF 50-150IN THE
SFC-700MB LAYER WITH MUCAPES OF 500-1500 J/KG OVER MAINLY THE SOUTH
1/3 OF THE FCST AREA. LFC AROUND 700MB IN THE SOUNDINGS WITH THE CIN
IN A RATHER DEEP 900-700MB LAYER. CAPE PROFILE IS DEEP...BUT SKINNY.
WITH WARM CLOUD DEPTH OF AROUND 3500 METERS...THE SKINNY CAPE OF 500-
1500 J/KG DOES NOT SEEM LIKE ENOUGH FOR A BIG HAIL THREAT. WITH THE
AREA LOOKING TO BE NORTH OF THE WARM FRONT SUN EVENING AND THE CIN
BELOW 700MB...APPEARS MAIN TORNADO AND STRONG WIND THREAT WOULD
BE SOUTH OF THE FCST AREA. ALSO...NUMEROUS SHRA/TSRA EXPECTED TO
BE SPREADING INTO/ACROSS THE AREA SUN AFTERNOON/ EVENING...ALL
COMPETING FOR THE SAME CAPE/SHEAR...WILL REDUCE THE SEVERE THREAT
FROM ANY ONE TSRA. CONCERNS AS WELL ON SUN WITH HIGH TEMPS BEING
TOO WARM AND CAPE ON THE HIGH SIDE GIVEN THICKENING
CLOUDS/SHRA/TSRA SPREADING NORTH INTO THE AREA DURING THE
AFTERNOON.
THE 3500 METER WARM CLOUD DEPTH...A WARM FRONT TO THE SOUTH FOR
LIFTING...PW VALUES NEAR 200 PERCENT OF NORMAL AND A FEED OF THIS
MOISTURE ON A 40-50KT 850MB JET SUN NIGHT ALL POINT TSRA BEING
EFFICIENT RAIN MAKERS AND A HEAVY RAIN THREAT. CONSIDERED A FLOOD
WATCH FOR SUN NIGHT/MON...BUT IT WOULD HAVE AND TO BE RATHER BROAD
WITH QPF DETAIL DIFFERENCES AMONG THE MODELS. WILL ISSUE AND ESF FOR
NOW AND PASS ALONG CONCERNS TO THE MIDNIGHT CREW.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 310 PM CDT SAT MAY 10 2014
MAIN FORECAST CONCERNS MON THRU TUE NIGHT...SHRA/TSRA CHANCES/RAIN
AMOUNTS MON INTO MON NIGHT...COOLING TEMPERATURES.
MODEL RUNS OF 10.12Z OFFERING A TIGHTER CONSENSUS MON/MON NIGHT AS
THE MID LEVEL TROUGH LIFTS INTO THE UPPER MIDWEST AND THE SFC LOW
LIFTS TO LK SUPERIOR. TREND IS TOWARD COMPROMISE OF THE EARLIER RUNS
ON STRENGTH/TIMING OF THE MID LEVEL TROUGH INTO THE REGION WITH
SOMEWHAT BETTER RUN-TO-RUN CONSISTENCY BY THE ECMWF. IMPROVING
CONSENSUS TUE/TUE NIGHT AS THE TROUGH VIRTUALLY STALLS OVER THE
CENTRAL CONUS. FCST CONFIDENCE IN THE MON-TUE NIGHT PERIOD IS
AVERAGE TO GOOD THIS CYCLE.
BROAD/DEEP FORCING/LIFT CONTINUES OVER THE AREA MON...ALONG WITH A
FEED OF THE 1.5 INCH PW VALUES ON A 30-40KT 850MB JET. STRONGEST OF
THIS IS OVER THE FCST AREA IN THE MORNING...GRADUALLY TRANSLATING
EAST MON AFTERNOON/EVENING AS THE SFC THRU 850MB COLD FRONT/TROUGH
MOVE EAST INTO/ACROSS THE AREA. PLENTY OF FORCING/LIFT REMAINS OVER
THE WEST SIDE OF THE FCST AREA MON AFTERNOON/EVENING...WITH THE 700-
500MB TROUGH AXIS STILL WEST OF THE AREA AND SHORTWAVES LIFT UP THE
EAST SIDE OF THE TROUGH THRU WESTERN MN. HEAVIEST RAIN THREAT SHIFTS
EAST OF THE AREA THRU MON AFTERNOON/EVENING...BUT SHRA/TSRA LOOK TO
CONTINUE ACROSS THE ENTIRE FCST AREA MON AFTERNOON. AFTER A POSSIBLE
1 TO 2 INCHES OF RAIN SUN NIGHT...ANOTHER 1/4 TO 3/4 INCH OF RAIN
POSSIBLE MONDAY. SHRA/TSRA THEN TAPER OFF AND EXIT EAST THRU MON
NIGHT/TUE MORNING AS THE SFC-850MB TROUGH/FRONT MOVE EAST OF THE
AREA.
CONCERNS WITH THE SEVERE THREAT DEPICTED IN DAY 3 SIMILAR TO THOSE
CENTERED ON SUN EVENING. SHRA/TSRA SHOULD BE ONGOING ACROSS MUCH OF
THE UPPER MIDWEST MON MORNING...AND CONTINUE MUCH OF THE DAY. DEBRIS
CLOUDS AND THE RAIN SHOULD LIMIT HIGH TEMPS AND POTENTIAL FOR CAPE
TO BUILD ACROSS THE AREA. USED THE MODEL/ENSEMBLE CONSENSUS HIGHS
FOR MON BUT IF CLOUDS/SHRA/TSRA PREVAIL...THESE ARE LIKELY TOO WARM
RESULTING IN TOO MUCH CAPE IN THE PROGS. MON CAPE PROFILES ALSO DEEP
AND SKINNY SIMILAR TO SUN EVENING. NUMEROUS SHRA/TSRA ALL COMPETING
FOR THE SAME CAPE/SHEAR WILL AGAIN LIMIT THE SEVERE POTENTIAL WITH
ANY ONE STORM.
DRIER/COOLER 925-700MB AIR WRAPS ACROSS THE AREA FOR TUE AFTERNOON/
NIGHT FOR WHAT SHOULD BE DRY PERIODS AND A DECREASE OF CLOUDS. 850MB
TEMPS IN THE +2C TO -1C RANGE BY 12Z WED. THIS PLUS LIGHT WINDS AND
MOSTLY CLEAR SKIES TUE NIGHT...LOWS IN THE UPPER 30S-LOW 40S WED
MORNING APPEAR REASONABLE.
FOR WEDNESDAY THRU SATURDAY.../DAYS 4 TO 7/...
MAIN FORECAST CONCERNS THIS PERIOD...COOL TEMPERATURES AND -SHRA
CHANCES THRU THE PERIOD.
MEDIUM RANGE MODEL RUNS OF 10.00Z/10.12Z HAVE COME INTO BETTER
AGREEMENT WED/THU ON LOCATION/STRENGTH OF THE TROUGHING TO SLOWLY
MOVE ACROSS CENTRAL NOAM. MODELS CONVERGING TOWARD THE EARLIER
ECMWF RUNS. IMPROVING CONSENSUS FOR SOME NORTHERN STREAM ENERGY TO
DROP INTO THE UPPER MIDWEST THU/FRI...FURTHER DEEPENING THE TROUGH
AND CARVING OUT A MID LEVEL OVER THE WESTERN GREAT LAKES FOR FRI
INTO SAT. GIVEN THE IMPROVED MEDIUM RANGE MODEL CONSENSUS...DAY
4-7 FCST CONFIDENCE IS GENERALLY GOOD THIS CYCLE...ESPECIALLY FOR
BELOW NORMAL TEMPERATURES.
ONE SURGE OF COLDER LOW LEVEL HAS ALREADY SETTLED OVER THE REGION BY
WED. A SECONDARY...EVEN COLDER SURGE IS POISED TO DROP SOUTH INTO
THE REGION FOR THU/FRI. 850MB TEMPS PROGGED TO BOTTOM OUT IN THE
-1C TO -3C RANGE AT 12Z FRI. SOME TEMP RECOVERY SAT AS WARMER AIR
ACTUALLY WRAPS IN FROM THE NORTH. SIGNAL REMAINS CONSISTENT FOR
850MB TEMPS TO BE SOME 1.5 TO 2 STANDARD DEVIATIONS BELOW NORMAL
ACROSS THE UPPER MIDWEST FOR MOST OF THE WE-SAT PERIOD. CONFIDENCE
IS GOOD FOR DAY 4-7 HIGHS TO BE SOME 10-15F BELOW NORMAL. LOWS
THRU THE PERIOD A LITTLE TRICKER AND DEPENDENT ON EXTENT OF CLOUD
COVER ANY ONE NIGHT. WITH MODEST 925-700MB MOISTURE AND THE DEEP
COLD CORE TROUGH/LOW AND CYCLONIC FLOW OVER THE REGION...CLOUDS
EXPECTED TO PREVAIL MUCH OF THE WED-SAT PERIOD. IF ANY ONE OF THE
NIGHTS ENDS UP MORE CLEAR THAN CLOUDY...PATCHY FROST WOULD BE
EXPECTED...ESPECIALLY ALONG/NORTHEAST OF I-94 THU/FRI NIGHTS. FOR
NOW THE MODEL/ENSEMBLE CONSENSUS HIGHS/LOWS FOR WED- SAT ARE WELL
TRENDED.
LESS CONFIDENCE ON -SHRA CHANCES IN THE WED-SAT PERIOD AS THESE
CHANCES WILL DEPEND ON THE TIMING OF STRONGER SHORTWAVES THRU THE
PERSISTENT TROUGHING OVER THE REGION. PRESENT TIMING HAS ONE
STRONGER SHORTWAVE DROPPING INTO THE REGION WED THEN MORE
SHORTWAVE ENERGY ROTATING AROUND THE DEEP TROUGH/MID LEVEL LOW
OVER THE WESTERN GREAT LAKES FRI/SAT. WITH THE DEEP CYCLONIC
FLOW...COLD CORE OF 850-700MB TEMPS OVER THE REGION...STEEP SFC-
700MB LAPSE...RATES/WEAK INSTABILITY DURING THE AFTERNOON
HOURS...ANY SHORTWAVE WOULD BE CAPABLE OF TRIGGERING SCT -SHRA.
SMALL -SHRA CHANCES MUCH OF THE WED-SAT PERIOD STILL LOOK
REASONABLE UNTIL THE SHORTWAVE TIMING DETAILS CAN BE SORTED OUT.
ANY PRECIP DURING THE WED-SAT WOULD BE SCT AND LIGHT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1207 PM CDT SAT MAY 10 2014
SMALL AREA OF LIGHT SHOWERS/SPRINKLES CONTINUES TO ADVANCE NORTHEAST
AHEAD OF A WEAK SHORT WAVE TROUGH. THE 10.14Z HRRR SEEMS TO HAVE A
GOOD HANDLE ON THESE SHOWERS AND BRINGS THEM EASTWARD WHILE
WEAKENING THEM. WILL SHOW A VCSH FOR THESE SHOWERS THROUGH ABOUT THE
MIDDLE OF THE AFTERNOON. THERE SHOULD THEN BE A BREAK IN THE
ACTIVITY BEFORE THE NEXT SHORT WAVE TROUGH COMES IN AND BRINGS
ANOTHER CHANCE FOR SOME ACTIVITY. EXPECTING THIS NEXT ROUND OF
ACTIVITY TO APPROACH THE TAF SITES AROUND 00Z AND THERE COULD BE
SOME THUNDER WITH IT AS THE 10.12Z NAM BUFKIT SOUNDINGS SHOW 200-400
J/KG OF ELEVATED SKINNY CAPE. WILL HAVE A VCTS FOR THIS NEXT ROUND
BASED ON THIS AVAILABLE CAPE...BUT NOT SURE HOW LONG TO HOLD ONTO
THE CHANCES AS THE HRRR WOULD PUSH IT THROUGH DURING THE EVENING
HOURS WHILE THE NAM WOULD HOLD ONTO SOME CHANCES THROUGH MUCH OF THE
NIGHT. FOR NOW...WILL LIMIT THE CHANCES TO THE EVENING HOURS AS BOTH
THE 10.12Z GFS AND 10.00Z ECMWF WOULD ALSO SUGGEST THE BETTER
CHANCES WILL BE IN THE EVENING. THROUGH THE ENTIRE PERIOD...THE BEST
MOISTURE LOOKS TO BE MAINLY IN THE MID LEVELS SO EXPECT CEILINGS TO
REMAIN VFR.
&&
.HYDROLOGY...
ISSUED AT 310 PM CDT SAT MAY 10 2014
MINOR FLOODING/HIGH WATER CONTINUES ALONG PORTIONS OF THE
MISSISSIPPI RIVER. LATER SUN AFTERNOON INTO MON EVENING WILL BE A
WET PERIOD...WITH POTENTIAL FOR 1 TO 2 OR MORE INCHES OF RAINFALL
DURING THAT PERIOD. THE HEAVIEST RAIN/HIGHEST TOTALS WILL FALL
SUNDAY NIGHT INTO MONDAY MORNING. THESE RAINS COULD HAVE
ADDITIONAL IMPACTS ON BOTH TRIBUTARIES AND THE MISSISSIPPI
RIVER...SLOWING THE RATES OF FALL...PRODUCE ADDITIONAL RISES OR
RENEWED FLOODING. WILL ISSUE AN ESF CONCERNING THE POTENTIAL
HEAVY RAINS SUN NIGHT/MON AND RISING RIVER LEVELS/FLOODING THREAT.
CHECK THE LATEST HYDROLOGIC STATEMENTS FOR THE DETAILS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RRS
LONG TERM....RRS
AVIATION.....04
HYDROLOGY....RRS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1207 PM CDT SAT MAY 10 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 300 AM CDT SAT MAY 10 2014
GFS/NAM IN GOOD AGREEMENT WITH SPINNING AN UPPER LEVEL SHORTWAVE
TROUGH ACROSS THE NORTHERN PLAINS THIS AFTERNOON...TRACKING ACROSS
THE UPPER MISSISSIPPI RIVER VALLEY TONIGHT. 500-1000 J/KG MUCAPE VIA
THE GFS/NAM AT 00Z ACROSS SOUTHERN MN/WESTERN WI FOR THE SHORTWAVE
TO WORK ON. BUFKIT SOUNDINGS POINT TO SKINNY CAPE THOUGH...NOT
FAVORABLE FOR STRONG UPDRAFTS. SOME 0-6 KM SHEAR BY 06Z...40-50
KTS...BUT THE INSTABILITY IS WEAKENED/NIL BY THAT TIME. THIS SYSTEM
IS PACKING A BIT MORE PUNCH THAN PREVIOUS MODEL RUNS
SUGGESTED...MAKING A PERIOD OF SHOWERS/STORMS MORE LIKELY FOR THE
SAT NIGHT. SOME HINTS THAT THE CENTER OF THE FORECAST AREA COULD
MISS OUT ON MOST OF THE ACTIVITY...WITH A PIECE OF THE LOW LEVEL
MOISTURE TRANSPORT INTO THE SHORTWAVE...WHILE THE BULK OF IT FOCUSES
INTO A WEST-EAST RUNNING WARM FRONT ACROSS THE IA/MO BORDER. DRY SUB
CLOUD LAYER PER SOUNDINGS SUGGEST SOME ENHANCED GUSTINESS POSSIBLE
AROUND ANY OF THE ANTICIPATED STORMS. SKINNY CAPE WOULDN/T SUPPORT
LARGE HAIL FORMATION...ALTHOUGH SOME PEA SIZED CAN/T BE RULED OUT.
OVERALL...SEVERE THREAT LOOKS MINIMAL.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 230 AM CDT SAT MAY 10 2014
WEST COAST LONGWAVE UPPER LEVEL TROUGH GOING TO SLOWLY PUSH INTO THE
PLAINS SUN/MON...EJECTING PIECES OF ENERGY NORTHEAST TOWARD THE
LOCAL AREA. A COLD FRONT/SFC LOW DEVELOPS IN RESPONSE TO THE
FORCING...EXTENDING FROM CENTRAL MN INTO THE SOUTHERN PLAINS BY 00Z
MON...GRADUALLY EASING INTO EASTERN WI MONDAY NIGHT. LOW LEVEL
MOISTURE TRANSPORT RAMPS UP AHEAD OF A SFC FRONT...WITH THE NOSE OF
A 40-50 KT 850 MB POINTING INTO SOUTHWEST WI SUN EVENING. THE STEADY
RIBBON OF LOW LEVEL MOISTURE PERSISTS ALONG/AHEAD OF THE SFC FRONT
INTO MONDAY. GFS/NAM A BIT MORE BULLISH ON THE INSTABILITY WITH THEIR
00Z RUNS COMPARED TO PREVIOUS DAYS...WITH 1000-2000 J/KG OF MUCAPE
PUSHING ACROSS WESTERN WI BY 18-00Z SUN/MON. 0-6 KM SHEAR 45-50 KTS
BY 00Z...WITH 30+ KTS IN THE 0-3 KM LAYER. SEVERE PARAMETERS
INCREASING FOR THE FORECAST AREA. PW/S CLIMB TO OVER 1 1/2 INCHES.
THE HIGHER SEVERE THREAT WILL CONTINUE TO BE TO THE SOUTH...BUT THE
THREAT FOR STRONG/SEVERE STORMS IS INCREASING. A LOT IS
UNCERTAIN...AS IN WHERE VARIOUS SFC BOUNDARIES FROM PREVIOUS
CONVECTION COULD LIE...IF ANY CONVECTION WILL GET GOING BEFORE THE
MAIN SURGE OF LOW LEVEL MOISTURE/FORCING SUN EVENING...HOW MUCH A
SOUTHERN BOUNDARY/WARM FRONT WILL IMPACT SEVERE POTENTIAL ADVANCING
NORTH ETC. IT SHOULD BE NOTED THAT SOUNDINGS LEAN TOWARD A SKINNY
CAPE PROFILE TOO...AGAIN...NOT FAVORABLE FOR STRONG
UPDRAFTS/EXPLOSIVE GROWTH. STAY TUNED.
PERIODS OF SHOWERS WILL PERSIST FOR MUCH OF MONDAY AS THE UPPER
LEVEL TROUGH STILL HANGS JUST EAST AND THE COLD FRONT TAKES ITS TIME
GOING EAST.
GFS/ECMWF FAVOR KEEPING THE REGION UNDER THE INFLUENCE OF THE UPPER
LEVEL TROUGH INTO NEXT WEEKEND. THE PERSISTENT NORTHWEST FLOW WILL
USHER IN ANOTHER ROUND OF COLDER AIR...WITH 850 MB TEMP ANOMALIES
VIA THE EC AROUND -1 MUCH OF THE WEEK. HIGHS WILL PROBABLY STRUGGLE
TO REACH 60 MANY OF THE DAYS. MEANWHILE...SOME DIFFERENCES BETWEEN
THE EC AND GFS ON WHETHER OR NOT RIPPLES IN THE UPPER LEVEL FLOW
WILL TRACK ACROSS THE REGION...AND THEN...IF THERE WOULD BE ANY PCPN
CHANCES WITH THEM. CONFIDENCE LOW IN THESE DETAILS...SO WILL STICK
WITH THE CONSENSUS SOLUTION FOR THE MOMENT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1207 PM CDT SAT MAY 10 2014
SMALL AREA OF LIGHT SHOWERS/SPRINKLES CONTINUES TO ADVANCE
NORTHEAST AHEAD OF A WEAK SHORT WAVE TROUGH. THE 10.14Z HRRR SEEMS
TO HAVE A GOOD HANDLE ON THESE SHOWERS AND BRINGS THEM EASTWARD
WHILE WEAKENING THEM. WILL SHOW A VCSH FOR THESE SHOWERS THROUGH
ABOUT THE MIDDLE OF THE AFTERNOON. THERE SHOULD THEN BE A BREAK IN
THE ACTIVITY BEFORE THE NEXT SHORT WAVE TROUGH COMES IN AND BRINGS
ANOTHER CHANCE FOR SOME ACTIVITY. EXPECTING THIS NEXT ROUND OF
ACTIVITY TO APPROACH THE TAF SITES AROUND 00Z AND THERE COULD BE
SOME THUNDER WITH IT AS THE 10.12Z NAM BUFKIT SOUNDINGS SHOW
200-400 J/KG OF ELEVATED SKINNY CAPE. WILL HAVE A VCTS FOR THIS
NEXT ROUND BASED ON THIS AVAILABLE CAPE...BUT NOT SURE HOW LONG TO
HOLD ONTO THE CHANCES AS THE HRRR WOULD PUSH IT THROUGH DURING THE
EVENING HOURS WHILE THE NAM WOULD HOLD ONTO SOME CHANCES THROUGH
MUCH OF THE NIGHT. FOR NOW...WILL LIMIT THE CHANCES TO THE EVENING
HOURS AS BOTH THE 10.12Z GFS AND 10.00Z ECMWF WOULD ALSO SUGGEST
THE BETTER CHANCES WILL BE IN THE EVENING. THROUGH THE ENTIRE
PERIOD...THE BEST MOISTURE LOOKS TO BE MAINLY IN THE MID LEVELS SO
EXPECT CEILINGS TO REMAIN VFR.
&&
.HYDROLOGY...
ISSUED AT 300 AM CDT SAT MAY 10 2014
MINOR FLOODING/HIGH WATER CONTINUES ALONG PORTIONS OF THE
MISSISSIPPI RIVER. TODAY THROUGH MONDAY WILL BE A WET PERIOD...WITH
ADDITIONAL AMOUNTS FROM 1 TO 2 INCHES POSSIBLE. THE HEAVIEST
RAIN/HIGHEST TOTALS WILL FALL SUNDAY NIGHT. THESE RAINS COULD HAVE
ADDITIONAL IMPACTS ON BOTH TRIBUTARIES AND THE MISSISSIPPI
RIVER...SLOWING THE RATES OF FALL OR PRODUCE ADDITIONAL RISES.
CHECK THE LATEST HYDROLOGIC STATEMENTS FOR THE DETAILS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RIECK
LONG TERM....RIECK
AVIATION...04
HYDROLOGY....RIECK
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1118 PM MDT SUN MAY 11 2014
.UPDATE...
ISSUED AT 1108 PM MDT SUN MAY 11 2014
UPDATED TO CANCEL WINTER WX ADVISORY FOR SOUTHERN EL PASO COUNTY
AND TO ADD OTERO COUNTY TO THE FREEZE WARNING. ALSO ADJUSTED
SNOW AMOUNTS FOR TONIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 258 PM MDT SUN MAY 11 2014
...SIGNIFICANT SNOWS EXPECTED TO CONTINUE ACROSS THE CENTRAL
MOUNTAINS AND PIKES PEAK REGION...
UPPER LOW NEARING THE FOUR CORNERS REGION THIS AFTERNOON WILL BE
LIFTING NORTHEASTWARD OVERNIGHT INTO NORTHEAST CO BY 18Z MONDAY.
SURFACE FRONT HAS PUSHED THROUGH ALL OF THE SOUTHEAST PLAINS AS OF
21Z. SNOWFALL AMOUNTS SO FAR HAVE BEEN HIGHLY DETERMINED BY THE
SNOW LEVELS AND WARM GROUND. PIKES PEAK REGION HAS ALREADY DROPPED
INTO THE LOWER TO MID 30S...WITH UPPER 20S ACROSS TELLER COUNTY.
THIS HAS BEEN THE AREA WHICH HAS RECEIVED THE MOST SNOW...THOUGH A
LOOK AT WEB CAMS ACROSS THE AREA SHOWS THAT WARM GROUND HAS
MITIGATED ACCUMULATIONS SOME. MAINLY GRASSY SURFACES HAVE
ACCUMULATION...BUT OCCASIONALLY HAVE SEEN SOME SNOW ON THE PAVEMENT
DURING THE HEAVIER SNOW BURSTS. STILL WAITING FOR SNOW LEVELS TO
DROP ACROSS THE UPPER ARKANSAS RIVER VALLEY...WITH SALIDA AND BUENA
VISTA AIRPORTS STILL IN THE 40S AS OF 21Z. DOWN AROUND COLORADO
CITY AND RYE...TEMPERATURES ARE STILL IN THE UPPER 30S AND LOWER
40S...BUT TEMPERATURES HAVE BEEN DROPPING QUICKLY THIS LAST HOUR AND
SUSPECT RAIN/SNOW SWITCH OVER FOR THE UPPER ARKANSAS RIVER VALLEY OF
FREMONT AND CHAFFEE AND THE LOWER ELEVATION OF THE WET MOUNTAINS IS
NOT LONG OFF.
AS FOR HIGHLIGHTS...HAVE LEFT THEM AS IS. A LITTLE CONCERNED THAT
LATER SWITCH OVER TO SNOW ACROSS LOWER ELEVATIONS OF CHAFFEE COUNTY
MAY HURT SNOW TOTALS SOME...BUT BEST FORCING WILL CONTINUE TO TREK
ACROSS THIS AREA THROUGH THE EVENING...AND LATEST 18Z NAM IS NOW
HITTING THIS AREA WITH AROUND 4 INCHES OF SNOW THROUGH THE EVENING
HOURS. ONCE THE SWITCH OVER OCCURS...IT WILL NOT TAKE LONG FOR
ACCUMULATIONS TO START STACKING UP...THOUGH SUSPECT THE WARM GROUND
WILL MAKE FOR A WIDE RANGE OF ACCUMULATIONS WITH LOCATIONS LIKE
SALIDA COMING UP ON THE LOW END. ON THE FENCE WITH UPGRADING TO A
WINTER STORM WARNING FOR THE LOWER ELEVATIONS OF THE WET MOUNTAINS
AND THE NORTHERN SANGRE DE CRISTO MOUNTAINS. THERE COULD BE A FEW
AREAS THAT HIT AROUND 12 INCHES...BUT THE LATE TRANSITION OVER TO
SNOW WILL LARGELY KEEP AMOUNTS MORE IN THE ADVISORY RANGE.
AS FOR TIMING OF THE HEAVIER SNOWS...HEAVIEST SHOULD FALL NOW
THROUGH MIDNIGHT. AFTER MIDNIGHT...BEST FORCING SHIFTS NORTH OF THE
AREA...AND ALTHOUGH THERE WILL STILL BE SOME WRAP AROUND SNOWS
ACROSS THE CENTRAL MOUNTAINS/PIKES PEAK AREA...DOWNSLOPE NORTHERLY
WINDS OFF THE PALMER DIVIDE SHOULD OPEN UP THE PRECIPITATION MINIMUM
ACROSS SOUTHERN EL PASO AND NORTHERN PUEBLO COUNTIES. THIS COULD
OCCUR AS EARLY AS 10 PM. WINTER WEATHER ADVISORIES FOR SOUTHERN EL
PASO COUNTY MAY RUN A TAD TOO LONG...BUT WILL LET LATER SHIFTS
MONITOR TRENDS AND MAKE ANY NEEDED ADJUSTMENTS.
THE WET MOUNTAINS AND SOUTHERN I-25 CORRIDOR WILL SEE MORE
CONVECTIVE BURSTS OF RAIN/SNOW...WHICH SHOULD SWITCH OVER TO ALL
SNOW BY AROUND 6 PM. HOWEVER...MAJORITY OF THE HEAVIER SNOW MAY BE
DONE BY 6 AM...AND POSSIBLY EVEN SOONER IF LATEST HRRR IS CORRECT.
AS FOR THE SOUTHEAST PLAINS...HAVE EXTENDED THE FREEZE WARNING TO
INCLUDE CROWLEY COUNTY...AS AM GETTING A FEW HOURS OF SUBFREEZING
TEMPERATURES THERE. NOT MUCH SNOW IS EXPECTED...THOUGH SWITCH OVER
COULD OCCUR AROUND 6 PM FOR PUB...AROUND MIDNIGHT FOR LHX...AND EVEN
LATER FOR POINTS FARTHER EAST WHERE IT MAY STAY ALL RAIN...OR GO TO
A BRIEF RAIN/SNOW MIX TOWARDS MORNING BEFORE IT ENDS. GRASSY
SURFACES AROUND PUEBLO...WALSENBURG...TRINIDAD COULD SEE AN INCH OR
TWO AT ANY TIME...BUT WARM GROUND MAY MELT IT OFF QUICKLY.
ON MONDAY...ANOTHER TRAILING DISTURBANCE DROPS IN IN NORTHWEST FLOW
ALOFT...AND SENDS ANOTHER ROUND OF SNOW INTO THE MOUNTAIN
AREAS...PARTICULARLY ALONG THE CONTINENTAL DIVIDE. THIS CONTINUES
INTO MONDAY EVENING. ITS POSSIBLE THESE AREAS MAY NEED ANOTHER
HIGHLIGHT...MOST LIKELY AN ADVISORY...BUT SINCE THERE SEEMS TO BE A
DISTINCT BREAK BETWEEN THE TWO SYSTEMS...WILL LET LATER SHIFTS
DETERMINE WHAT IF ANY HIGHLIGHTS WILL BE NEEDED. SUSPECT THAT TO
SOME EXTENT...THE HIGHER SNOWFALL AMOUNTS IN THE GFS MAY BE A TAD
OVERDONE DUE TO SOME CONVECTIVE COMPONENT...AND HAVE GONE CLOSER TO
THE NAM FOR NOW. -KT
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 258 PM MDT SUN MAY 11 2014
SECONDARY UPPER LOW AND UPSLOPE FLOW WILL KEEP SOME SNOW GOING
OVER THE SAN JUANS/SANGRES MON EVENING...AND SOME ADDITIONAL LIGHT
ACCUMULATION IS POSSIBLE WITH BEST CHANCE OVER THE EASTERN SAN
JUANS. PRECIP THEN SLOWLY SHIFTS SOUTH OVERNIGHT AS UPPER TROUGH
MOVES EAST...WHICH WILL END MOST ACCUMULATING SNOW BY EARLY
TUESDAY MORNING. MANY AREAS WILL HAVE THE POTENTIAL FOR FREEZING
TEMPS ONCE AGAIN BY EARLY TUE MORNING...THOUGH AMOUNT OF MID LEVEL
CLOUDINESS MAY BE THE DETERMINING FACTOR ON HOW WIDESPREAD COLD
TEMPS BECOME. VERY GRADUAL WARMING AND DRYING TREND BEGINS
TUESDAY AFTERNOON...THOUGH SOME RESIDUAL MOISTURE/INSTABILITY
OVER THE MOUNTAINS MAY PRODUCE A FEW LIGHT SHOWERS TUE AFTERNOON.
NEUTRAL TO WEAK WARM ADVECTION...COMBINED WITH INCREASING MAY SUN
SHOULD BOOST MAX TEMPS SEVERAL DEGF VERSUS MONDAYS HIGHS...THOUGH
READINGS WILL STILL RUN WELL BELOW SEASONAL AVERAGES. ANOTHER THREAT
OF SOME PATCHY FROST TUE NIGHT/WED MORNING AS SKIES
CLEAR...ESPECIALLY EL PASO COUNTY/LOW LYING AREAS OF PUEBLO
COUNTY.
UPPER RIDGE THEN BUILDS OVER THE WESTERN U.S. FOR MID-WEEK...THEN
GRADUALLY FLATTENS NEXT WEEKEND. IN GENERAL...GRADUAL
WARMING/DRYING TREND IN STORE FOR THE AREA THROUGH THE
PERIOD...THOUGH A COUPLE WAVES EMBEDDED IN THE NW FLOW MAY
PRODUCE AT LEAST SOME ISOLATED -TSRA/-SHRA OVER THE EASTERN
MOUNTAINS AND PLAINS THU/FRI AS MODEST LOW LEVEL MOISTURE RETURNS
SLOWLY INTO THE HIGH PLAINS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1108 PM MDT SUN MAY 11 2014
KALS...VFR CONDITIONS EXPECTED FOR ALS FOR THE NEXT 24 HRS...WITH
SHOWERS IN THE VCNTY THROUGH 18Z TODAY. AFTER 18Z...A BRIEF
BREAK THEN SHOWERS WILL REDEVELOP OVER THE MTS TO THE WEST.
KCOS AND KPUB...IFR CONDITIONS WITH -SHRASN IN THE VCNTY THROUGH 18Z
AND STRONG NORTH WINDS WITH GUSTS UP TO 35 MPH EXPECTED. VFR
CONDITIONS THEN DEVELOPING AFTER 18Z AS THE UPPER SYSTEM LIFTS OUT
TO THE EAST. MOORE
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
FREEZE WARNING UNTIL 8 AM MDT MONDAY FOR COZ083>089-093-094.
WINTER STORM WARNING UNTIL 9 AM MDT MONDAY FOR COZ058>063-073-
076-080>082-084.
WINTER WEATHER ADVISORY UNTIL 9 AM MDT MONDAY FOR COZ072-074-075-
077>079.
WINTER WEATHER ADVISORY UNTIL 6 AM MDT MONDAY FOR COZ066-068.
&&
$$
UPDATE...28
SHORT TERM...KT
LONG TERM...PETERSEN
AVIATION...MOORE
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
105 AM CDT MON MAY 12 2014
.DISCUSSION...
930 PM CDT
STORMS ACROSS THE FAR SOUTHERN FORECAST AREA HAVE SHOWN A
CONSISTENT WEAKENING TREND IN THE PAST HOUR. STILL SOME
CONVERGENCE ON THE OUTFLOW BOUNDARY WITH WARM/MOIST ADVECTION
850-925MB ADVECTION INTO THIS AREA. SO SOME REGENERATION OF
STORMS MAY CONTINUE AS RADAR TRENDS HAVE INDICATED IN MCCLEAN
COUNTY...ALTHOUGH THE REFLECTIVITY TREND IS GENERALLY DOWNWARDS.
SO THE FLOODING THREAT IS GRADUALLY DIMINISHING.
TEMPORARY SUPPRESSION AND MID-LEVEL DRYING BEHIND MCS SHOULD KEEP
MUCH OF THE FORECAST AREA QUIET THROUGH 3 AM OR SO. WIDESPREAD
CONVECTION ACROSS WESTERN IOWA SHOULD EVOLVE EAST NORTHEAST WITH
POSSIBLE SCATTERED DEVELOPMENT AHEAD OF THIS ON THE LOW-LEVEL JET
AND JUST INCREASING UPPER/MID-LEVEL FORCING. THIS IS MOST FAVORED
IN NORTH CENTRAL ILLINOIS...INCLUDING TOWARD ROCKFORD. THIS WOULD
HAVE A SMALL SEVERE WEATHER CHANCE. OVERALL BUILDING HEIGHTS
SHOULD LIMIT A WELL-DEVELOPED MCS FROM THE WEST MOVING INTO THE
FORECAST AREA.
MTF
//PREV DISCUSSION...
300 PM CDT
FORECAST CONCERNS ARE MAINLY ON THE IMMEDIATE SEVERE WEATHER
CHANCES THROUGH EARLY/MID EVENING. ALSO FOCUS ON THE SEVERE
WEATHER POTENTIAL ON MONDAY...PRIMARILY MONDAY LATE AFTERNOON INTO
THE NIGHTTIME PERIOD.
OVERNIGHT INTO MONDAY MORNING...
STRONG UPPER JET WILL PROPAGATE AROUND THE UPPER TROUGH LATE
TONIGHT INTO THE MORNING ON MONDAY AND WITH THAT LEAD TO FURTHER
AMPLIFYING OF THE UPSTREAM RIDGE...INCLUDING BUILDING HEIGHTS
ACROSS MUCH OF THE FORECAST AREA. MUCH OF THE FORCING FOR
RAIN/STORMS IN THIS PERIOD WOULD BE FOCUSED TO THE WEST AND NORTH
IN SUCH A PATTERN. THE STRONG LOW-LEVEL JET WILL AT LEAST IN PART
BE OVER THE AREA...HOWEVER THE NOSE OF IT WILL BE POINTED FURTHER
NORTH. CONVECTIVE CHANCES LOOK MINIMAL AND MAINLY THE NORTHWEST
FORECAST AREA TOWARD ROCKFORD. CHANCES MAY BE INCREASED SOMEWHAT
IF ANY ORGANIZED CONVECTION FROM THE CENTRAL PLAINS WERE TO
PROPAGATE EASTWARD INTO NORTHERN IL...BUT THE GRADUALLY MORE
MERIDIONAL FLOW AND ORIENTATION OF FORECAST CORFIDI VECTORS WOULD
PUSH MUCH OF THE CONVECTION NORTH OF THE AREA. LOW TEMPS WILL BE
BALMY WITH CONTINUED SOUTHERLY FLOW AND HIGH DEW POINT AIR...WITH
SOME PLACES EXPERIENCING SOME WARMING OF TEMPS LATER THIS
EVENING...ESPECIALLY THOSE IMPACTED BY EARLY EVE CONVECTION AND
THOSE COMMUNITIES NEAR THE LAKE SHORE THAT HAD AFTERNOON/EVE
COOLING.
MONDAY AFTERNOON THROUGH TUESDAY...
THE UPPER TROUGH WILL CONTINUE TO AMPLIFY AS THE UPPER JET TO ITS
FRONT AND BACK INTENSITY. A WARM AND MUGGY DAY IS ANTICIPATED
MONDAY. CONVECTIVE INHIBITION ON MONDAY AFTERNOON DOES LOOK TO BE
OVERCOME BUT A FOCUS IS NOT OVERLY EVIDENT IN OUR FORECAST AREA.
GRADUALLY MORE CONVERGENCE AND INCREASING DEEP LAYER MOISTURE AND
UPWARD MOTION IS FORECAST TO MOVE EASTWARD ACROSS MAINLY NORTH
CENTRAL ILLINOIS LATE IN THE DAY INTO EARLY EVE AND EASE ITS WAY
EASTWARD THROUGH THE REMAINDER OF THE NIGHT. THIS LOOKS LIKE A
PERIOD OF STORMS MOVING NORTHEAST WITHIN THE DEEP MOIST PLUME.
THE SEVERE POTENTIAL WOULD SEEM MOST FAVORED WITH THE INITIAL
CONVECTION IN THE LATE AFTERNOON/EVE AND THEN A GENERAL WANING
LATER INTO THE NIGHT. LOCALLY HEAVY RAINFALL WILL BE PROBABLE IN
SOME OF THESE STORMS AS THE PWATS ARE FORECAST TO BE AROUND 1.50
INCHES AND DEEP MOISTURE CONVERGENCE WILL BE ORIENTED PARALLEL TO
THE UPPER FLOW. THIS PLUME WILL SHIFT EASTWARD THROUGH TUESDAY
MORNING AND LIKELY POPS CERTAINLY SEEM JUSTIFIED TUESDAY MORNING. IF
THE FRONT IS SLOW ENOUGH SOME AFTERNOON ENHANCEMENT OF A FEW STORMS
COULD HAPPEN IN THE EAST...BUT THIS SEEMS MOST FAVORED EAST OF THE
FORECAST AREA AT THIS TIME.
THE COLD AIR ADVECTION WITH THE COLD FRONT...ALONG WITH POTENTIALLY
SOME ANAFRONTAL SHOWERS...WILL LIKELY LEAD TO FALLING TEMPS IN SOME
PLACES AT LEAST AT TIMES ON TUESDAY.
WEDNESDAY AND BEYOND...
LITTLE CHANGES MADE TO THIS PART OF THE FORECAST DUE TO ONGOING
HIGHER IMPACT WEATHER. LARGE MODEL DIFFERENCES EXIST IN THE WED-THU
TIME FRAME...WITH THE 12Z EC COMING IN SLOWER AND MORE AGGRESSIVE
WITH A LOW RIDING UP THE BAROCLINIC ZONE TO OUR EAST. THIS PROVIDES
WIDESPREAD SHOWERS WEDNESDAY AFTERNOON THROUGH EARLY THURSDAY AND
PARTICULARY COOL TEMPS. WITH AN EC/GFS/GOING FORECAST BLEND THIS
PROVIDES A FEW PERIODS OF CHANCE POPS.
TEMPS TO LOOK TO BE BELOW NORMAL NO MATTER WHICH MODEL VERIFIES IN
THE WED-FRI TIME FRAME. IF CONDITIONS CLEAR AND SURFACE RIDGING
MOVES OVER...POSSIBLY THU NIGHT...THERE PROBABLY WILL BE A CONCERN
FOR FROST.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* POSSIBLE MVFR CIGS EARLY THIS MORNING.
* GUSTY SOUTHERLY WINDS TODAY.
* TIMING AND CHANCES OF ADDITIONAL TSRA TODAY AND TONIGHT.
KJB
//DISCUSSION...UPDATED 06Z...
CHANCES AND TIMING OF ADDITIONAL CONVECTIVE ACTIVITY WILL BE THE
PRIMARILY WEATHER CONCERN ACROSS THE NORTHERN ILLINOIS TERMINALS
AGAIN TODAY AND TONIGHT. UNFORTUNATELY...CONFIDENCE IS LOW ON ANY
CONVECTIVE ACTIVITY MATERIALIZING ACROSS THE EASTERN TERMINALS
TODAY...AND FOR THIS REASON...THE FORECAST REMAINS DRY FOR THE
AREA.
THE MAIN ATTENTION EARLY THIS MORNING IS OUT WEST ACROSS CENTRAL
IOWA...WHERE A COMPLEX OF THUNDERSTORMS IS MOVING EASTWARD. THIS
ACTIVITY COULD IMPACT THE TERMINALS LATER THIS MORNING IF IT HOLDS
TOGETHER. HOWEVER...CONFIDENCE ON THIS MAKING IT TO THE EASTERN
TERMINALS BEFORE WEAKENING...IS TOO LOW TO INCLUDE A MENTION IN
THE TAF. TRAJECTORIES FOR THE STORM MOTIONS TEND TO SUPPORT AN
EAST-NORTHEASTERLY MOVEMENT OF THROUGH THE EARLY MORNING
HOURS...SO I HAVE INCLUDED THE MENTION OF A VCTS IN THE KRFD TAF
AFTER 10 UTC THIS MORNING...TO ACCOUNT FOR ANY OF THE REMNANTS OF
THIS ACTIVITY POSSIBLY IMPACTING THE TERMINAL.
THE WINDS SHOULD BECOME SOUTHERLY TOWARDS DAYBREAK WITH THE SURFACE
WARM FRONT STILL EXPECTED TO LIFT NORTH OF THE AREA. AS THIS
OCCURS...IT IS POSSIBLE THAT A FEW LOW CLOUDS OR A BRIEF PERIOD OF
LOWER CIGS COULD DEVELOP TOWARDS DAYBREAK AS LOWER LEVEL MOISTURE
CONTINUES TO STREAM NORTHWARD OVER THE AREA. I CONTINUED THE
MENTION OF SOME SCT015 CLOUDS IN THE GOING TAF. THERE IS A SMALL
THREAT FOR AN MVFR CIG AROUND 1500 FEET TO DEVELOP FOR A BRIEF
PERIOD THIS MORNING...BUT ANY LOWER CIGS SHOULD IMPROVE SHORTLY
AFTER DAYBREAK TODAY.
THE THREAT FOR CONVECTIVE ACTIVITY OVER OR NEAR THE TERMINALS
THROUGH THE DAY TODAY APPEARS LOW...BUT NOT ZERO. IT APPEARS THAT
ANY ACTIVITY...IF IT WERE TO DEVELOP ACROSS THE AREA...WOULD BE OF
FAIRLY LOW AREAL COVERAGE DUE THE LACK OF ANY SIGNIFICANT TRIGGER
MECHANISM ACROSS THE AREA. THERE ARE ALSO SOME CONCERNS ABOUT THE
POSSIBILITY OF HIGHER LEVEL CLOUD DEBRIS...FROM THE OVERNIGHT
STORMS...LINGERING OVER THE AREA TODAY AND LIMITING THE THREAT FOR
ADDITIONAL DEVELOPMENT. THE NEXT MAIN THREAT FOR A PERIOD OF
POSSIBLY MORE WIDESPREAD SHOWERS AND STORMS WILL LIKELY BE EITHER
LATE MONDAY NIGHT OR EARLY TUESDAY AHEAD OF AN APPROACHING COLD
FRONT.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* LOW FOR MVFR CIGS OVERNIGHT/EARLY MORNING.
* LOW FOR TSRA DURING THE DAY TODAY.
KJB
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
* TUESDAY...TSRA LIKELY IN THE MORNING.
* WEDNESDAY...CHANCE OF SHRA.
* THURSDAY...CHANCE OF SHRA.
* FRIDAY...SLIGHT CHANCE OF SHRA.
* SATURDAY...DRY/VFR.
&&
.MARINE...
242 PM...LOW PRESSURE OVER KANSAS WILL MOVE NORTHEAST TO LAKE
SUPERIOR TUESDAY MORNING. AS IT DOES...A WARM FRONT EXTENDING EAST
FROM THE LOW WILL MOVE NORTH ACROSS THE LAKE TONIGHT THROUGH
MONDAY NIGHT...SHIFTING EASTERLY WINDS SOUTHERLY. LOW LEVEL
MOISTURE WILL ALSO BE INCREASING AND AS IT SPREADS ACROSS THE
COOLER LAKE...AREAS OF FOG ARE POSSIBLE AND SOME OF THE FOG MAY
BECOME DENSE. CURRENT WIND SPEEDS ARE FAIRLY LIGHT IN THE 5-15 KT
RANGE AND WILL INCREASE INTO THE 15-25KT RANGE AND REMAIN THERE
UNTIL A COLD FRONT MOVES ACROSS THE LAKE TUESDAY MORNING. THERE IS
A POTENTIAL FOR WINDS TO BE A BIT STRONGER ON MONDAY...ESPECIALLY
WITH THE EASTERLY FLOW NORTH OF THE WARM FRONT ACROSS NORTHERN
LAKE MICHIGAN. THERE REMAINS UNCERTAINTY REGARDING THE POTENTIAL
FOR STRONG NORTHERLY WINDS WEDNESDAY NIGHT INTO THURSDAY AS LOW
PRESSURE DEEPENS MOVING NORTH ACROSS THE GREAT LAKES REGION. THIS
TIME PERIOD WILL NEED TO BE MONITORED FOR HIGHER NORTHERLY WIND
SPEEDS. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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Area Forecast Discussion
National Weather Service Lincoln IL
1118 PM CDT Sun May 11 2014
.DISCUSSION...
ISSUED 927 PM CDT Sun May 11 2014
The rest of WW #144 will be let go at 10 pm CDT. Most of the
stronger storms have shifted off to our east with some lingering
showers over north central McLean county. Large bow echo over
western Iowa tracking east northeast at 45 to 50 mph. Latest
HRRR model suggest what is left of the complex may get into
western IL just before 12z. Will continue to keep low chance
POPs across the north with the remainder of the area expecting
to see dry conditions. Overall, the grids are in good shape.
Will update the ZFP once our watch expires at 10 pm.
&&
.AVIATION...
ISSUED 1115 PM CDT Sun May 11 2014
Main concern will be with the potential for convection, currently
over central Iowa, to make it into at least our northern TAF sites
by morning. Based on the current movement of the large complex
of storms over central Iowa, have decided to add a VCTS group to
PIA and BMI between 11z and 14z. Until then, VFR conditions will
continue. We should see VFR cigs during the day on Monday with any
early morning showers out of the way by 16z or 17z. Then we will
wait for more storms along a cold front to move in after 23z from
west to east Monday evening. Confidence on coverage not very high
this far out for convection so will just include a VCTS group for
each site starting out west around 00z with the potential reaching
our eastern counties by 03z.
Surface winds will be from a 130-160 direction tonight and then
turn more southerly on Monday with speeds tonight in the 8 to 13 kt
range and then increase in speed to between 12 to 17 kts on Monday
with gusts up to 25 kts at times by late morning into the afternoon
hours.
Smith
&&
.PREV DISCUSSION...
ISSUED 248 PM CDT Sun May 11 2014
Air mass destabilizing quickly across central and southeast
Illinois early this afternoon. 18Z upper air sounding from our
office showing CAPE of around 2600 J/kg with no convective
inhibition, although shear values are not especially impressive.
Latest SPC mesoanalysis indicates CAPE`s are over 3000 J/kg south
of I-72, as dew points of 70 degrees have made it as far north as
Taylorville. Warm front extends from southern Nebraska along the
Iowa/Missouri border, but becomes more diffuse in northern
Illinois where it is more of a dew point discontinuity.
Thunderstorms have been percolating most of the day across the
Ohio Valley, and a persistent, small MCS is advancing across Iowa.
Some development has recently started as well across northeast
Missouri south of the main MCS. Has been quiet in our area the
last few hours, but latest radar returns are starting to show
thunderstorms developing between Taylorville and St Louis.
The primary forecast concern remains with the severe weather
threat over the next 24 to 36 hours.
SHORT TERM...Tonight through Tuesday:
Latest runs of the HRRR have been persistent with the Iowa storms
affecting more of the northern third of Illinois, with more
scattered strong/severe storms affecting our area through about
7 pm. Shear parameters don`t really improve any in our area, so
thinking that hail/wind threat will be the primary concerns here
with the tornado threat closer to the warm front. After sunset,
capping of the atmosphere will begin in the warm sector. Have
maintained some 30-40% PoP`s after midnight northwest of the
Illinois River, and slight chances as far east as I-55, with dry
conditions across the southeast half of the forecast area.
Similar convective parameters expected on Monday, with CAPE`s
rising to 2500-3000 J/kg, although shear remains on the low side.
Day2 slight risk basically along and northwest of the Illinois
River, where the shear will be a bit higher as it is closer to the
incoming cold front, and severe weather threat will mainly be mid
afternoon to early evening. With the front slowing down a tad,
will keep any PoP`s east of I-57 around 20% during the day, while
likely PoP`s around 60% found during the afternoon along/west of
the Illinois River. Have maintained the 60-70% PoP`s everywhere
during the night as the front slowly moves through, and over the
eastern CWA on Tuesday with some 80% values south of I-70 Tuesday.
Severe weather threat on Tuesday appears minimal, and would be
near the Indiana border if any did occur.
LONG TERM...Wednesday through Sunday:
A broad upper trough will be dominating much of the eastern half
of the nation into the first part of the weekend, with cool
conditions prevailing. The ECMWF has been persistent with a closed
upper low forming by late Thursday over the Great Lakes, then
lifting northward, while the GFS keeps a more progressive trough.
Toward the end of the weekend, the trough will finally start to
break down as an upper low digs southward across the Pacific
Northwest, causing rising heights over the center of the nation.
Most challenging area in this forecast period is with rain on
Wednesday. The tail end of the NAM is trending toward the solution
favored by the ECMWF and GEM for the last few days, with a surface
low riding northeast along the base of the trough, although the
NAM is much further west with it. The GFS has keep its surface
features much weaker and further east. Have kept the likely PoP`s
on Wednesday across the southeast third of the area, although the
ECMWF/GEM solutions would likely require this to be expanded
further northwest toward the I-55 corridor. Thursday and Friday,
the rain will be much more scattered in nature, as weak troughs
rotate around through the broad upper trough. Rain chances will
diminish this weekend as the upper flow flattens.
Geelhart
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
332 AM CDT MON MAY 12 2014
.SYNOPSIS...
ISSUED AT 321 AM CDT MON MAY 12 2014
LOW PRESSURE MOVING INTO WESTERN IA WILL LIFT NORTHEAST AS COLD
FRONT SWEEPS ACROSS THE STATE BY LATE TONIGHT. PATTERN WILL CHANGE
TO A MUCH COOLER REGIME AS CANADIAN HIGH PRESSURE DOMINATES
THROUGH THE REST OF THE WORK WEEK.
&&
.SHORT TERM /TODAY/...
ISSUED AT 321 AM CDT MON MAY 12 2014
TWO PROBLEMS TODAY ARE BOTH WITH CONVECTION THE EARLY MORNING
CONVECTION WILL BE AN ISSUE WITH THE POTENTIAL FOR LOCALLY HEAVY
RAINFALL MOVING INTO ALREADY SATURATED AREAS. THIS IS ASSOCIATED
WITH A WEAK WAVE IN THE FLOW THAT IS LIFTING NORTHEAST ACROSS THE
STATE. ADDITIONAL DEVELOPMENT IS LIKELY OVER THE SOUTHEAST HALF OF
THE STATE WITH THE COLD FRONT PROGRESSING EAST. THE HRRR HAS WHAT
SEEMS TO BE A REASONABLE HANDLE ON THIS. SEVERITY WILL DEPEND ON
HOW MUCH RECOVERY WE CAN ACHIEVE AFTER THE MORNING CONVECTION.
.LONG TERM /TONIGHT THROUGH SUNDAY/...
ISSUED AT 321 AM CDT MON MAY 12 2014
PRECIPITATION WILL MOVE OUT OF THE STATE BY 06Z AS THE PATTERN
CHANGES FROM A SOUTHWEST FLOW TO A NORTHWEST FLOW. CANADIAN HIGH
PRESSURE WILL DOMINATE THE WEEKS WEATHER WITH TEMPERATURES WELL
BELOW NORMAL. WILL POTENTIAL NEED TO CONSIDER SOME FROST WORDING
LATER IN THE WEEK, BUT CERTAINTY IS NOT THERE AT THIS TIME BECAUSE
OF THE POTENTIAL FOR SOME CLOUD COVER. IT WILL LIKELY TAKE UNTIL
THE WEEKEND BEFORE THE COOL HIGH PRESSURE MOVES OFF TO THE EAST.
WARMING AND AN INCREASED CHANCE FOR THUNDERSTORMS IS EXPECTED
LATER IN THE WEEKEND.
&&
.AVIATION...12/06Z
ISSUED AT 1249 AM CDT MON MAY 12 2014
THUNDERSTORMS WILL REMAIN POSSIBLE OVERNIGHT ESPECIALLY OVER THE
SOUTHEAST SITES. GUSTY WINDS FROM THE WEST TO SOUTHWEST ARE
POSSIBLE WITH STORM OUTFLOW ALONG WITH GREATLY REDUCED VSBYS WITH
HEAVY RAINFALL. THE PRECIPITATION SHOULD DIMINISH EARLY MONDAY
MORNING BEFORE INCREASING AGAIN LATE MORNING AND INTO THE
AFTERNOON. MVFR CIGS ARE EXPECTED TO DEVELOP MONDAY. A FRONTAL
BOUNDARY WILL ARRIVE LATE WITH A SWITCH TO WESTERLY WINDS.
&&
.HYDROLOGY...
ISSUED AT 321 AM CDT MON MAY 12 2014
THEN ENVIRONMENT REMAINS FAVORABLE FOR HEAVY RAINFALL AT LEAST
THROUGH EARLY THIS MORNING WITH THE LOW PRESSURE AND COLD FRONT
CLOSE. DECENT DEVELOPMENT OVER WESTERN IOWA AND TO THE SOUTHWEST
OF THE STATE WILL MOVE NORTHEAST THROUGH THE STATE THIS MORNING.
MOST VULNERABLE AREAS WILL BE THE SOUTHWEST AND SOUTH CENTRAL
AREAS...AND SOME IN THE NORTHWEST...WHERE RAINFALL TOTALS HAVE
BEEN IN THE 2 TO 3 INCH RAIN LOCALLY WITH SOME HIGHER TOTALS.
ADDITIONAL THUNDERSTORM DEVELOPMENT LATER IN THE DAY IS LIKELY TO
BE EAST OF THESE AREAS AND TO NOW ANTICIPATE EXTENDING THE FLASH
FLOOD WATCH AT THIS TIME.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 7 AM CDT THIS MORNING FOR ADAIR-ADAMS-
AUDUBON-BLACK HAWK-BOONE-BREMER-BUTLER-CALHOUN-CARROLL-CASS-
CERRO GORDO-CRAWFORD-DALLAS-EMMET-FRANKLIN-GREENE-GRUNDY-GUTHRIE-
HAMILTON-HANCOCK-HARDIN-HUMBOLDT-KOSSUTH-MADISON-MARSHALL-PALO
ALTO-POCAHONTAS-POLK-RINGGOLD-SAC-STORY-TAMA-TAYLOR-UNION-
WEBSTER-WINNEBAGO-WORTH-WRIGHT.
&&
$$
SYNOPSIS...MS MAY 14
SHORT TERM...MS MAY 14
LONG TERM...MS MAY 14
AVIATION...DONAVON
HYDROLOGY...MS MAY 14
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1142 PM CDT SUN MAY 11 2014
.UPDATE...
ISSUED AT 635 PM CDT SUN MAY 11 2014
DATA TRENDS THE PAST 3 HOURS NOW INDICATE THERE WILL BE A BREAK IN
ACTIVITY DURING THE EVENING HOURS.
THE CURRENT THUNDERSTORM COMPLEX IS SLOWLY MOVING INTO NORTHEAST
ILLINOIS BUT BOUNDARIES LEFT OVER WILL ALLOW STORMS TO PERSIST
OVER THE SOUTHERN PARTS OF THE AREA FOR THE NEXT SEVERAL HOURS.
AN EFFECTIVE BOUNDARY IS EVIDENT ACROSS SOUTHERN IOWA WITH NO
CELLULAR CLOUDS NORTH OF THE BOUNDARY AND DIURNAL CLOUDS ACROSS
MISSOURI. THIS BOUNDARY MAY PROVIDE A FOCUS FOR ADDITIONAL
ISOLATED TO SCATTERED STORMS THROUGH SUNSET.
DATA STILL SUGGESTS THE STORMS IN NEBRASKA WILL EVOLVE INTO A NEW
THUNDERSTORM COMPLEX ACROSS WESTERN IOWA THIS EVENING IN THE
BETTER FORCING AND SLOWLY MOVE EASTWARD WITH ACTIVITY ENTERING THE
NORTHWEST HALF OF THE AREA AFTER MIDNIGHT.
&&
.SYNOPSIS...
ISSUED AT 356 PM CDT SUN MAY 11 2014
12Z UA ANALYSIS HAS 850MB LOWS IN NORTHWEST MINNESOTA WITH A STRONG
850MB LOW IN WESTERN KANSAS. AN 850MB WARM FRONT RAN FROM THE KANSAS
LOW INTO SOUTHERN IOWA. A STRONG LLJ RAN FROM THE GULF COAST INTO
THE CENTRAL PLAINS. SATELLITE/RADAR TRENDS THROUGH MID AFTERNOON HAS
CONVECTION ACROSS EASTERN IOWA AND NORTHERN ILLINOIS WITH NEW
CONVECTION DEVELOPING IN THE PLAINS.
18Z SFC ANALYSIS HAS A WEAK LOW IN WESTERN WISCONSIN WITH A
DEVELOPING WARM FRONT SOUTHEAST INTO CENTRAL LAKE MICHIGAN. AN
IMPLIED LOW WAS IN SOUTHERN IOWA APPROACHING KOTM WITH ANOTHER LOW
IN WESTERN KANSAS. A FRONTAL BOUNDARY RAN FROM THE KANSAS LOW INTO
THE IOWA LOW NEAR KOTM WITH A WARM FRONT FROM NEAR KOTM NORTHEAST TO
THE WISCONSIN/ILLINOIS BORDER. DEW POINTS SOUTH OF THE FRONT WERE IN
THE 60S WITH 40S AND 50S IN THE NORTHERN PLAINS INTO THE GREAT LAKES
NORTH OF THE FRONT.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 356 PM CDT SUN MAY 11 2014
BOUNDARIES FROM THE NOCTURNAL THUNDERSTORM COMPLEX INITIATED A NEW
STORM COMPLEX ALONG THE WARM FRONT IN SOUTHERN IOWA THIS MORNING.
THIS NEW STORM COMPLEX MOVED EAST NORTHEAST AND IS SLOWLY DECAYING
ACROSS THE AREA.
HOWEVER...BOUNDARIES FROM THIS STORM ALONG WITH DIURNAL HEATING HAS
INITIATED NEW DISCRETE STRONG TO SEVERE STORMS THAT WILL CONTINUE
THROUGH LATE AFTERNOON.
BASED ON SATELLITE...RADAR...AND RAP TRENDS...THERE MAY BE A BREAK
IN STORM ACTIVITY THIS EVENING AS THE NEW SEVERE STORMS CONTINUE TO
DEVELOP AND MOVE NORTHEAST WELL WEST OF THE AREA.
AFTER MIDNIGHT THE STORMS OUT WEST WILL EVOLVE UPSCALE INTO ANOTHER
NOCTURNAL THUNDERSTORM COMPLEX THAT WILL SLOWLY MOVE INTO THE
NORTHWEST THIRD OF THE AREA. ISOLATED TO SCATTERED STORMS ARE VERY
POSSIBLE AHEAD OF THIS STORM COMPLEX AS MOISTURE CONTINUES TO FEED
INTO THE AREA.
ON MONDAY THE BETTER RAIN CHANCES WILL BE OVER THE NORTHWEST HALF OF
THE AREA DURING THE MORNING. DURING THE AFTERNOON...NEW CONVECTION
IS EXPECTED TO DEVELOP AS ANOTHER DISTURBANCE ALOFT MOVES THROUGH
THE AREA. BASED ON THE POSITION OF THE MAIN FEATURES AND OVERALL
EXPECTED FORCING...SEVERE STORMS ARE POSSIBLE.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 356 PM CDT SUN MAY 11 2014
MONDAY NIGHT THE MAIN COLD FRONT BEGINS MOVING THROUGH THE AREA.
CONVECTION IS EXPECTED TO BE WIDESPREAD AND MAY EVOLVE INTO A BAND
OF STRONG STORMS DURING THE EVENING HOURS. IF A BAND DOES FORM IT
WILL SLOWLY MOVE EAST OVERNIGHT.
ON TUESDAY...RAIN WILL END FROM WEST TO EAST DURING THE DAY WITH
MOST OF THE AREA BEING DRY BY MID DAY. TEMPERATURES WILL BE WELL
BELOW NORMAL.
HIGH PRESSURE MOVING THROUGH THE MIDWEST TUESDAY NIGHT WILL RESULT
IN DRY CONDITIONS WITH SEASONABLY COOL TEMPERATURES.
ON WEDNESDAY THE NEXT STORM SYSTEM MOVES NORTHEAST FROM THE SOUTHERN
PLAINS INTO THE OHIO VALLEY. THE TRENDS WITH THE MODELS HAVE BEEN TO
SLOWLY PULL THE STORM SYSTEM TO THE NORTH AND WEST.
WEDNESDAY NIGHT ON...
THERE CONTINUES TO BE DIFFERENCES BETWEEN THE GLOBAL MODELS AS TO
WHAT WILL OCCUR...BUT...ALL AGREE THAT TEMPERATURES WILL AVERAGE
BELOW NORMAL WEDNESDAY NIGHT THROUGH SUNDAY.
WEDNESDAY NIGHT/THURSDAY THE MODEL CONSENSUS HAS SLIGHT CHANCE TO
CHANCE POPS AS THE NEXT SYSTEM MOVES UP THROUGH THE OHIO VALLEY. THE
TREND IN THE MODELS HAS BEEN TO SLOWLY BRING THE STORM FURTHER TO
THE NORTH AND WEST.
THE MODEL CONSENSUS HAS MAINLY DRY CONDITIONS THURSDAY NIGHT AS THE
STORM SYSTEM EXITS THE AREA.
FRIDAY THROUGH SATURDAY THE MODEL CONSENSUS HAS MAINLY SLIGHT CHANCE
POPS FRIDAY AND SATURDAY WITH MAINLY DRY CONDITIONS FRIDAY NIGHT.
DISTURBANCES WILL CONTINUE TO ROTATE AROUND THE UPPER LOW OVER THE
GREAT LAKES PRODUCING MAINLY DIURNAL SHOWERS. IF ENOUGH CLEARING CAN
TAKE PLACE FRIDAY NIGHT AND WINDS REMAIN LIGHT...THERE MAY BE A
POTENTIAL FOR FROST.
DRY CONDITIONS SHOULD BE SEEN SATURDAY NIGHT AS HIGH PRESSURE MOVES
THROUGH THE AREA.
ON SUNDAY...THE MODEL CONSENSUS HAS SLIGHT CHANCE TO CHANCE POPS FOR
ROUGHLY THE WESTERN HALF OF THE AREA AS THE NEXT STORM SYSTEM MOVES
EAST FROM THE PLAINS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1133 PM CDT SUN MAY 11 2014
A LARGE...BUT PROGRESSIVELY MORE LOOSELY ORGANIZED COMPLEX OF
STORMS WILL SPREAD EAST FROM CENTRAL IOWA INTO EASTERN IOWA AND
NORTHWEST ILLINOIS THE REST OF TONIGHT. THIS MAY BRING SOME GUSTY
WINDS...ESPECIALLY TO NORTHEAST IOWA. VFR CONDITIONS WILL DROP TO
MVFR/HIGHER IFR AT TIMES IN ANY STORM. MONDAY WILL CONTINUE TO SEE
A RISK FOR SHOWERS AND STORMS...MOST WIDESPREAD IN THE LATE
AFTERNOON AND EVENING HOURS. AT THAT TIME...ANOTHER ROUND OF
POTENTIAL MVFR/IFR IS LIKELY IN STORMS. WINDS WILL BE SOUTH TO
SOUTHEAST AROUND 10 KTS THROUGH THE PERIOD.
ERVIN
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...08
SYNOPSIS...08
SHORT TERM...08
LONG TERM...08
AVIATION...ERVIN
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1215 AM CDT Mon May 12 2014
...UPDATE TO AVIATION...
.SYNOPSIS...
ISSUED AT 1007 PM CDT SUN MAY 11 2014
Water vapor imagery and 00Z upper air analysis indicate a strong
closed off upper level low shifting eastward across the Four Corners
Region. A +70kt upper level jet is lifting northeast across western
Kansas. Near the surface, a strong cold front extending from
northeastern Kansas southwest into the Oklahoma panhandle, is
pushing southeast across central Kansas. Much colder and drier
air is spilling southward into western Kansas with surface
dewpoints dropping mainly into the 40s(F) with a few 30s(F)
out near the Colorado border.
&&
.SHORT TERM...(This evening through Monday)
ISSUED AT 254 PM CDT SUN MAY 11 2014
Abbreviated AFD due to ongoing warning operations.
From my mesoscale discussion at 1:53 PM...
(Convection already has developed by the same mesoscale assessments
still applies)
Special 18Z KDDC raob shows just a little bit of CIN remaining. Won`t
be long before convection develops. Visible satellite imagery shows
increasing cumulus along the dryline/front. HRRR indicates thunderstorms
developing along the Highway 283 corridor in the 3-4 pm time range.
Right moving Bunkers shows propagation vectors northeasterly at 45 kt.
Initial threat will be large hail (up to 20! on the LHP using NAM thermodynamic
and kinematic variables) and damaging outflow winds. There is an small
window of tornadic opportunity between 7 and 9 pm as low level winds
back across central/south central-Kansas but all the big wedge/strong tornadoes
should remain across Nebraska/Iowa with just small spin ups/weak tornadoes
in our area, if possible.
Convection will depart the area tonight. Some light showers will be
possible on the backside of the departing wave. It will be windy post
frontal through tomorrow. Right now conditions look borderline for wind
advisory criteria.
.LONG TERM...(Monday night through Sunday)
ISSUED AT 122 PM CDT SUN MAY 11 2014
An upper level longwave trough will be moving across the Plains on
Tuesday but should be dry with the moisture pushed east of the area.
Colder temperatures will accompany this trough with overnight lows
on Monday night into the mid 30s and highs on Tuesday in the low to
mid 60s. Strong northwest winds will mix down to the surface with
winds of 15 to 30 mph and partly cloudy skies.
For Wednesday into Thursday, dry northwesterly upper level flow will
follow with highs slowly warming into the upper 60s and 70s.
Wednesday morning may be the coldest morning with light winds and
lows in the low to mid 30s.
For Friday and Saturday, a few showers and thunderstorms may form as
as some upper air disturbances in northwest flow aloft interact with
increasing upslope moisture. Lows will be in the 40s and highs
around 70 to 75.
On Sunday, of next week, upper level ridging is forecast with dry
and warmer temps around 80.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday night)
ISSUED AT 1215 AM CDT MON MAY 12 2014
MVFR/IFR cigs will prevail at all TAF sites through early this
afternoon as low level stratus developing behind the exiting cold
front persists across central and southwest Kansas. The cigs will
continue to lift through the afternoon with VFR returning by
Monday evening. As for winds, surface high pressure across the
Northern Rockies will build southeast into the Colorado Rockies
today. As a result, northwesterly winds of around 15 to 30kt will
persist through Monday afternoon.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 35 63 37 69 / 0 0 0 0
GCK 34 62 37 68 / 0 0 0 0
EHA 34 61 35 68 / 0 10 0 0
LBL 34 62 36 70 / 0 10 0 0
HYS 35 63 38 69 / 0 0 0 0
P28 40 66 42 70 / 0 10 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY until 1 AM CDT /Midnight MDT/ early this morning
FOR KSZ030-031-043>046-061>066-074>081-084>090.
&&
$$
SYNOPSIS...JJohnson
SHORT TERM...Sugden
LONG TERM...Kruse
AVIATION...JJohnson
AREA FORECAST DISCUSSION
NWS JACKSON KY
215 AM EDT MON MAY 12 2014
.UPDATE...
ISSUED AT 215 AM EDT MON MAY 12 2014
A FEW SHOWERS HAVE DEVELOPED OVER THE NE PART OF THE FORECAST AREA.
THE HRRR MODEL HAS THIS IN HAND...AND IS SHOWING THE PRECIP HEADING
OUT TO THE EAST OVERNIGHT. HAVE UPDATED TO INCLUDE A SLIGHT CHANCE OF
PRECIP IN THAT AREA FOR A SHORT TIME OVERNIGHT.
UPDATE ISSUED AT 1109 PM EDT SUN MAY 11 2014
THE FORECAST REMAINS ON TRACK TONIGHT. SOME OF THE MORE SHELTERED
VALLEYS HAVE DROPPED OFF INTO THE MID 60S...SO A FEW UPPER 50S STILL
LOOK ACHIEVABLE. THICKER HIGH CLOUD BLOW OFF FROM EARLIER CONVECTION
IS ALSO THINNING ACROSS THE NORTHERN HALF OF THE AREA...SO WILL
MAINTAIN PARTLY CLOUDY SKIES NORTH AND MOSTLY CLEAR SKY CONDITIONS
SOUTH...BESIDES A FEW PATCHES OF MID-LEVEL CLOUDS DEVELOPING FROM
TIME TO TIME. FRESHENED UP THE HOURLY SKY COVER...TEMPERATURES...AND
DEW POINTS ACCORDING TO THE LATEST TRENDS IN OBSERVATIONS.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 301 PM EDT SUN MAY 11 2014
FAIRLY QUIET PATTERN IN STORE FOR EASTERN KENTUCKY THROUGH TUESDAY
MORNING. A RIDGE OF HIGH PRESSURE SHOULD KEEP THINGS HIGH AND DRY
OVERNIGHT INTO EARLY MONDAY MORNING. THE MODEL DATA IS ALL SUGGESTING
THAT JUST ENOUGH INSTABILITY AND LOW LEVEL MOISTURE WILL BE AVAILABLE
TO SPARK SHOWER AND THUNDERSTORMS ACROSS THE AREA...WITH THE
AFTERNOON PEAK HEATING HOURS PREFERRED. THE LATEST MOS GUIDANCE AND
MODEL TIME HEIGHTS AND SOUNDINGS ALSO SUGGEST THIS POSSIBILITY. WITH
THE MODELS ALL SHOWING FAIRLY SIMILAR SOLUTIONS FOR THE AREA FROM
LATE TONIGHT THROUGH TUESDAY MORNING...THE NAM12 SOLUTION SEEMED AS
GOOD AS ANY FOR THIS GO ROUND. IN SPITE OF A GOOD DEAL OF SHOWER AND
STORM ACTIVITY ONGOING ACROSS CENTRAL AND WESTERN KENTUCKY AND
SOUTHERN INDIANA...IT APPEARS THAT IT WILL BE TOO DRY SHOWERS OR
STORMS TO FORM ACROSS EASTERN KENTUCKY TODAY AND TONIGHT. THEREFORE...THE
NEW FORECAST WILL FEATURE A DRY OVERNIGHT PERIOD...WITH ISOLATED
SHOWERS AND STORMS BEGINNING TO FIRE UP BETWEEN 16 AND 17Z ON MONDAY.
ONCE THE SUN BEGINS TO SET AND HEATING IS LOST...ANY EXISTING SHOWERS
OR STORMS WILL DISSIPATE QUICKLY LATE TOMORROW AFTERNOON. MONDAY
NIGHT AND TUESDAY LOOK TO BE WARM AND DRY AS HIGH PRESSURE BUILDS
WESTWARD AND KEEPS PRECIPITATION PUSHED OFF TO OUR WEST. TEMPERATURES
WILL BE WELL ABOVE NORMAL THE NEXT COUPLE OF DAYS...WITH TOMORROWS
HIGHS TOPPING OUT IN THE MID 80S AND LOWS ON MAKING IT INTO THE UPPER
50S AND LOWER 60S THE NEXT TWO NIGHTS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 425 PM EDT SUN MAY 11 2014
THE PERIOD WILL BEGIN WITH AN UPPER LEVEL RIDGE CENTERED OFF THE
SOUTHEAST UNITED STATES WITH RIDGING NORTH INTO THE CENTRAL
APPALACHIANS. ANOTHER RIDGE IS EXPECTED TO BE IN PLACE ALONG THE WEST
COAST WITH A TROUGH EXPENDING FROM CENTRAL CANADA SOUTH INTO THE
PLAINS AND SOUTHERN ROCKIES. BY THE START OF THE PERIOD...THE ECMWF
IS QUICKER MOVING A SHORTWAVE TROUGH NEAR THE US/CANADIAN BORDER EAST
AS IT IS WITH A MORE SOUTHERN SHORTWAVE WORKING THROUGH THE ROCKIES.
DOWNSTREAM OF THIS TROUGH THE ECMWF IS ALSO FURTHER WEST WITH THE
TROUGH AXIS OVER THE EASTERN CONUS.
THROUGH WED EVENING...THE TROUGH AXIS WILL GRADUALLY WORK EAST AND
APPROACH THE MS VALLEY REGION AS THE AXIS OF THE RIDGE TO THE EAST
MOVES OFF INTO THE ATLANTIC AND THE RIDGE AXIS MOVES ONTO THE US WEST
COAST. AT THE SFC...A PARENT SFC LOW SHOULD TRACK WELL NORTH OF THE
REGION INTO QUEBEC BY WED EVENING. THE TRAILING SFC COLD FRONT WILL
ENTER THE COMMONWEALTH ON TUE AFTERNOON AND BEGIN TO BECOME
STATIONARY AS IT NEAR THE MID AND UPPER OH VALLEY AND APPALACHIANS. A
SFC WAVE IS PROGGED TO DEVELOP ALONG THE BOUNDARY TUE NIGHT AND TRACK
INTO THE COMMONWEALTH BY WED EVENING. THE ECMWF CONTINUES TO BE
DEEPER WITH THE INITIAL SOUTHERN ROCKIES SHORTWAVE AS IT MOVES TOWARD
THE MID MS VALLEY REGION. THIS LEADS TO MODEL DIFFERENCES WITH A
MORE WESTERN AND DEEPER SFC WAVE DEVELOPMENT TUE NIGHT INTO WED.
THE SFC LOW SHOULD EVENTUALLY TRACK INTO THE GREAT LAKES REGION BY
LATE WED NIGHT OR THU AND SEND THE COLD FRONT TO THE EAST OF THE
REGION BY MIDDAY ON THU. DEEPER MOISTURE SHOULD ALSO DEPART TO THE
EAST AT THAT TIME...BUT THE UPPER TROUGH AXIS WILL NOT WORK ACROSS
THE AREA UNTIL FRIDAY. A WESTERN RIDGE AND EASTERN TROUGH IS
EXPECTED TO START THE WEEKEND...WITH THE RIDGE AXIS WORKING INTO THE
PLAINS BY THE END OF THE PERIOD AND AT THAT TIME...THE TROUGH AXIS
SHOULD MOVE TOWARD THE EASTERN SEABOARD.
CONVECTION CHANCES WILL SOMEWHAT DIURNALLY DRIVEN EARLY IN THE
PERIOD...BUT AS THE SFC FRONT APPROACHES LATE TUE NIGHT AND WED
MOISTURE WILL INCREASE AND A WEAK LEAD SHORTWAVE MAY APPROACH FROM
THE SOUTHWEST. HOWEVER...AS THE MAIN SHORTWAVE APPROACHES AND THE SFC
WAVE TRACKS THROUGH THE OH VALLEY LATER WED INTO THU AM...CONVECTION
CHANCES WILL BE BEST. UNSETTLED WEATHER WILL STILL REMAIN POSSIBLE
INTO THE START OF THE WEEKEND...BEFORE THE TROUGH AXIS MOVES TO THE
EAST.
TEMPERATURES WILL BEGIN THE PERIOD ABOVE NORMAL...BUT BELOW NORMAL
TEMPERATURES...AVERAGE ABOUT 10 OR MORE DEGREES BELOW NORMAL ARE
EXPECTED BEHIND THE FRONT...FROM THU INTO SUN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 215 AM EDT MON MAY 12 2014
A FEW SHOWERS WERE OCCURRING OVER THE NE PART OF THE FORECAST AREA AT
THE START OF THE PERIOD. THEY SHOULD MOVE OUT BEFORE DAWN...AND
PROVIDE LITTLE IN THE WAY OF CEILING/VISIBILITY RESTRICTIONS.
HOWEVER...FOG WILL AFFECT THE DEEPER VALLEYS IN EASTERN KY WITH
LOCALIZED VISIBILITY LESS THAN A MILE UNTIL SHORTLY PAST SUNRISE.
THERE IS A POSSIBILITY OF SHOWERS POPPING UP DURING THE DAY ON
MONDAY...AND A FEW THUNDERSTORMS CAN NOT BE RULED OUT. THE
PROBABILITY AT ANY GIVEN LOCATION IS RATHER LOW...AND ONLY VCSH HAS
BEEN USED IN TAFS. OUTSIDE OF HEAVIER SHOWERS...VFR IS ANTICIPATED
THROUGH MOST OF THE DAY. WILL LOOK FOR ANY PRECIP TO DIE OUT TOWARD
EVENING.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HAL/GEOGERIAN
SHORT TERM...AR
LONG TERM...JP
AVIATION...HAL
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1156 PM CDT Sun May 11 2014
.UPDATE...
Issued at 1155 PM CDT SUN MAY 11 2014
The AVIATION section has been updated for the 06Z TAF issuance.
UPDATE Issued at 930 PM CDT SUN MAY 11 2014
The likelihood of lightning strikes has dropped low enough
this evening that there will be no mention of them in the HWO or the
gridded products overnight. Despite ridging in the mid levels, the
tepid lower trop is such that a stray light rain shower cannot be
ruled out overnight, however.
&&
.SHORT TERM...(Tonight through Tuesday night)
Issued at 317 PM CDT SUN MAY 11 2014
Pockets of surface-based instability continue to expand over the
WFO PAH CWA this afternoon, aided by decent insolation and weak to
moderate directional shear (25-35 knots) aloft (as evidenced by
the anvil rain plumes oriented from northwest to southeast). The
old cold pool has eroded over southeast IL and southwest IN from
the morning convection, so distinct theta-e gradients are in
place. Given the GOES Water Vapor imagery, the moisture gradient
aloft implies a gradient in lapse rates as well, helping to
enhance updrafts. (This is evidenced by the newly organized storms
with hail in Southeast IL).
The 12km RUC also suggests that the expended CAPE along and north
of the implied surface warm frontal reflection arcing from
northwest to southeast through southeast Illinois into northwest
Kentucky. Further expenditure of CAPE through 01z suggests that
the pool of convective instability should drop markedly. In
addition, model heights are expected to rise this evening with a
subtle change in balance takes place between the eastern U.S. ridge
and the center of the sharpening trough over Western Nebraska.
Expect that rain chances will be essentially nil over the entire
WFO PAH CWA by midnight, as the warm frontal boundary moves well
north of the area and shear decreases with time.
As mentioned in yesterday`s discussion, channeled vorticity along
the eastern limb of the trough near the inflection point between
the trough/ridge circulation (cyclonic/anticyclonic flow) will aid
in creating some lift in advance of an approaching moisture plume
from the Gulf of Mexico around daybreak on Monday. This transition
zone for convection will move slowly east through Monday
afternoon, as the main trough actually sharpens and becomes
slightly negatively tilted west of Iowa and Missouri Monday night
into Tuesday morning.
By 09z (4 am CDT) Tuesday morning, the cold front associated with
this trough is expected to move into western sections of the WFO
PAH Forecast area (Southwest IL/Southeast MO). By late evening
Monday and into early Tuesday, the coverage of showers and
thunderstorms should pick up significantly. It is at this time,
that my concern for heavy rain potential will increase, with the
potential for at least minor flooding by daybreak on Tuesday over
parts of Southeast Missouri northeast to the Mississippi River.
QPF values in excess of two inches would not be out of the
question during that time period.
The 12km NAM-WRF is actually suggesting a new closed circulation
will develop at the based of the mean trough over the upper
Midwest, somewhere near the OK/TX panhandles by Tuesday night,
moving into southern Missouri by Wednesday evening. This is similar
to what the ECMWF advertised in the Friday/Saturday model runs. This
will lead to enhanced precipitation, both pre/post frontal as the
frontal boundary remains fixed along the Interstate 57/55 corridor
in Southern IL/Southeast Missouri. Most of the upright
(thunderstorm) instability may be mixed out by Tuesday afternoon and
night, but warm top (satellite reference) convection processes will
likely take over increasing the effectiveness of the rainfall from
Tuesday into Wednesday. There is still some question with respect to
severe potential during this time period, but heavy rainfall still
remains the dominant threat Tuesday into Wednesday.
.LONG TERM...(Wednesday through Sunday)
Issued at 417 PM CDT SUN MAY 11 2014
Confidence is fairly high concerning the general synoptic pattern in
the Wed-Sun time frame. It is looking more and more like a high
amplitude mid level trof will be carved out from southeast Canada
southward all the way into the Ms River Valley by the Wed/Thu
period. On east side of the trof, broad swly flow aloft will be
evident. As a sfc low lifts ne along the spine of the Appalachians
Wed, it appears showers will once again overspread most of the
forecast area. Highest rain amounts will probably be over wrn KY and
sw IN. Once the sfc low pulls off to the northeast Wed night, and
the h50 trof axis moves east of the region, rain chcs should
decrease considerably for much of the remainder of the extended.
However, very low height fields and extensive daytime cloudiness
behind the system will likely lead to an extended period of below
normal temperatures. Highs are only expected to reach the 60s most
locations Thu/Fri/Sat.
&&
.AVIATION...
Issued at 1155 PM CDT SUN MAY 11 2014
The latest guidance seems to be trending wetter for Monday, but
figure with the entire area in the warm sector, diurnal convection
will be very sparse in coverage. Kept the TAFs dry for the entire
period. South southwest winds should gust 20-25kts for much of the
day.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...DRS
SHORT TERM...Smith
LONG TERM...GM
AVIATION...DRS
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1135 PM CDT SUN MAY 11 2014
.AVIATION...
FOR THE 12/06Z TAF ISSUE...EXPECT MVFR CIGS TO CONTINUE SPREADING
NORTHWARD INTO EAST TEXAS AND WESTERN LOUISIANA. ISOLATED SHWRS
AND TSTMS WILL ALSO BE ONGOING IN THE EAST TEXAS LAKES AREA AS
WELL AS NORTH CENTRAL LOUISIANA. BY 09Z AND CONTINUING UNTIL
14Z...IFR CIGS BETWEEN 5 HUNDRED AND 1 KFT WILL BE COMMON ACROSS
THE REGION. LIGHT FOG WILL ACCOMPANY THE LOWER CIGS AT A FEW
TERMINALS WITH VSBYS BETWEEN 3 AND 5 MILES. VFR SHOULD RETURN TO
MOST LOCATIONS BETWEEN 15Z AND 16Z...WITH CIGS 3 TO 4 KFT.
ISOLATED TSTMS WILL DEVELOP WITH AFTERNOON HEATING...BECOMING MORE
NUMEROUS FROM SE OK INTO E TX AFTER 21Z. SURFACE WIND SOUTH TO
SOUTHEAST 10 TO 15 KTS TONIGHT AND INTO MONDAY WITH GUSTS 20 TO 25
KTS AFTER 14Z. /14/
&&
.PREV DISCUSSION... /ISSUED 1028 PM CDT SUN MAY 11 2014/
DISCUSSION...
INTERESTING FORECAST UPDATE FOR THE REMAINDER OF THE OVERNIGHT
HOURS. CONVECTION ACROSS NATCHITOCHES PARISH HAS FINALLY
DISSIPATED BUT RENEWED CONVECTION CONTINUES TO DEVELOP ACROSS DEEP
EAST TEXAS AND SHOWS SIGNS OF EXPANDING NORTH AND WEST. THIS WOULD
MAKE SENSE AS LATEST RUN OF THE HRRR SUGGESTS INCREASING CAPE
OVERNIGHT ACROSS OUR WESTERN HALF. CONVECTION IS PROBABLY BEING
AIDED BY A 50KT LOW LEVEL JET OFF SHV`S WSR-88D VAD WIND PROFILER.
A QUICK LOOK AT ISENTROPIC SFCS NEAR OR SLIGHTLY ABOVE THE 930MB
LEVEL SUGGEST A CONTINUATION OF ISENTROPIC LIFT WITH LOW CONDENSATION
PRESSURE DEFICITS ACROSS OUR WESTERN HALF AS WELL.
HAVING SAID ALL THIS...FOR THE UPDATE...WILL CONTINUE WITH A
SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS THROUGH THE REMAINDER
OF THE NIGHT ACROSS ALL ZONES...EVEN THOUGH I`M A LITTLE MORE
CERTAIN OF THE BEST COVERAGE BEING ACROSS OUR WESTERN ZONES WHERE
THE INSTABILITY OVERNIGHT WILL BE GREATER.
TEMPERATURES AS OF 03Z ARE RUNNING A LITTLE WARMER THAN THIS TIME
AND GIVEN THE QUICK RETURN TO THE LOW LEVEL CLOUD COVER ALREADY
SEEN ON IR IMAGERY ALONG AND SOUTH OF A LFK...SHV...MLU
LINE...ANOTHER WARM NIGHT IS IN STORE ACROSS THE REGION. HOURLY
TEMPS ARE ALMOST DEAD ON WITH FCST HOURLY TEMPS AND OVERNIGHT MINS
ARE FORECAST TO BE SOME 2 TO 3 DEGREES WARMER THAN LAST NIGHT. FOR
THAT REASON...TEMPS APPEAR TO BE IN PRETTY GOOD SHAPE.
EXPECTING SOUTHEAST WINDS NEAR 10 TO 15 MPH AREAWIDE WITH AN
OCCASIONAL GUST FROM TIME TO TIME GIVEN THE STRONG PRESSURE
GRADIENT IN THE LOWER LEVELS.
ONLY UPDATE NECESSARY APPEAR TO BE AN EXTENSION TO THE POP
FORECAST SPATIALLY BUT OTHERWISE...NO OTHER CHANGES ARE NECESSARY.
FCST UPDATE OUT SHORTLY...13.
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 73 86 67 79 57 / 20 50 60 70 50
MLU 70 86 67 83 60 / 20 50 50 60 50
DEQ 71 82 60 70 51 / 20 60 80 70 50
TXK 71 83 62 72 54 / 20 60 80 70 50
ELD 70 84 66 78 55 / 20 50 60 70 50
TYR 73 84 61 70 52 / 20 60 80 60 50
GGG 73 85 65 74 54 / 20 50 80 70 50
LFK 73 87 69 79 55 / 20 50 60 70 50
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
516 AM EDT MON MAY 12 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 515 AM EDT MON MAY 12 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A BUILDING RIDGE ALONG THE
W COAST OF NAMERICA WITH AMPLIFIED DOWNSTREAM TROF OVER THE ROCKIES.
MAIN PIECE OF ENERGY IS IN THE BASE OF THE TROF OVER COLORADO.
WAA/ISENTROPIC ASCENT DOWNSTREAM INTO THE UPPER LAKES IS SUPPORTING
A LARGE AREA OF SHRA/TSRA LIFTING NE ACROSS MN/WI EARLY THIS
MORNING. SHORTWAVE MOVING NE INTO WRN WI IS FURTHER AIDING THE PCPN.
INSTABILITY HAS BEEN SLOW TO ADVANCE N PER SPC MESOANALYIS...SO
WHILE SHRA ARE ADVANCING STEADILY N AND E...TSRA ARE LAGGING FARTHER
AND FARTHER S WITHIN THE OVERALL SHRA AREA.
HIGH RES MODEL GUIDANCE...PARTICULARLY THE HIGH RES RAPID REFRESH...
HAS A DECENT HANDLE ON APPROACHING SHRA. UTILIZED RADAR TRENDS AND
HIGH RES GUIDANCE TO SWING A PERIOD OF CATEGORICAL POPS ACROSS THE
FCST AREA THIS MORNING. FORTUNATELY...PCPN AMOUNTS DON`T LOOK TO BE
EXCESSIVE AS MAIN AREA OF TSRA WILL PASS BY TO THE S. STILL...
EXPECT ROUGHLY 0.5 TO 0.75 INCHES WHICH WILL GIVE AREA
RIVERS/STREAMS A BOOST IN FLOW. AS SUPPORTING SHORTWAVE MOVES NE OF
THE AREA...MUCH OF THE AFTN MAY TURN DRY IN ITS WAKE. POPS WERE
LOWERED INTO THE CHC/SCT CATEGORY...BUT BELIEVE MANY AREAS WILL
PROBABLY SEE A GOOD PERIOD OF DRY WEATHER THIS AFTN. WITH PCPN AT A
MINIMUM DURING THE AFTN...TEMPS WILL HAVE A CHANCE TO RESPOND...AT
LEAST IN AREAS WHERE GENERAL EASTERLY FLOW IS NOT OFF THE GREAT
LAKES. BUMPED TEMPS UP INTO THE UPPER 50S/LWR 60S ACROSS MUCH OF THE
INTERIOR. HIGH RES RAPID REFRESH SHOWS TEMPS RISING TO AROUND 70F
OVER THE INTERIOR W THIS AFTN...CERTAINLY POSSIBLE IF CLOUDS THIN
OUT SUFFICIENTLY.
AS SFC LOW PRES LIFTS FROM WRN WI ACROSS WRN LAKE SUPERIOR
TONIGHT...WARM FRONT WILL ATTEMPT TO MOVE INTO UPPER MI. AT THIS
POINT...IT APPEARS THE WARM FRONT MAY JUST SLIP INTO FAR SRN UPPER
MI. ADDITIONAL SHRA/TSRA WILL LIKELY DEVELOP AS SFC LOW/WARM FRONT
LIFT N...THOUGH PCPN COVERAGE PROBABLY WON`T BE AS WIDESPREAD AS
WHAT WILL OCCUR THIS MORNING. WITH ELEVATED CAPE UP AROUND 1000J/KG
AND DEEP LAYER SHEAR AROUND 30KT OR SO...STORMS WILL HAVE THE
POTENTIAL TO BECOME ORGANIZED WITH ISOLD SVR POSSIBLE...MAINLY OVER
FAR SCNTRL UPPER MI...CLOSER TO WARM FRONT. MAIN THREAT SHOULD BE
HAIL...BUT WITH PRECIPITABLE WATER 200-250PCT OF NORMAL...HVY
RAINFALL WILL BE A GOOD BET WITH ANY TSRA.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 504 AM EDT MON MAY 12 2014
DEEP TROUGH FOR MAY AND REALLY ANYTIME OF THE YEAR STRETCHES FROM
CENTRAL CANADA TO THE SOUTHERN PLAINS ON TUESDAY. SFC LOW CURRENTLY
OVER THE CENTRAL PLAINS SHOULD BE JUST NORTHWEST OF LK SUPERIOR
DAYBREAK ON TUESDAY. OCCLUDED FRONT WILL BE SLICING ACROSS CWA
THROUGH MID MORNING...EXITING EASTERN CWA BY EARLY AFTN. SHOULD BE AT
LEAST SCT SHRA/TSRA EXPECTED ALONG AND AHEAD OF FRONT AS HIGHER
1000-850MB THETA-E POOLS ALONG THE BOUNDARY. SHARP DRYING ENDS ANY
RAIN QUICKLY OVER WEST HALF IN THE MORNING...BUT MAY SEE ISOLD
SHRA/TSRA OVER FAR SOUTHEAST CWA AS WEAK LOW-LEVEL CONVERGENCE
LINGERS AND AS ANOTHER WEAKER SHORTWAVE/Q-VECTOR CONVERGENCE AT
H85-H5 LIFTS OVER FAR EAST CWA. ANY STORMS AHAEAD OF FRONT IN THE
MORNING SHOULD BE WEAK AS 1-6KM MUCAPE AND MLCAPE BOTH DIMINISH
STEADILY COMPARED TO THE OVERNIGHT HOURS. TEMPS WILL RISE INTO THE
60S OVER THE CNTRL WHERE WEST WINDS DOWNSLOPE...IMT-ESC-MNM...BUT
WILL STAY IN THE 50S OVER THE WESTERN/NORTHWEST CWA WITH GRADIENT
WINDS OFF LK SUPERIOR. THOSE WINDS COULD BE QUITE GUSTY...ESPECIALLY
OVER THE MORE EXPOSED KEWEENAW...WHERE NAM/GFS SOUNDINGS INDICATE
MIXED LAYER BUILDING TO H85-H8 WITH WINDS OVER 35 KTS IN THE MIXED
LAYER.
QUIET WEATHER TUESDAY NIGHT AND WEDNESDAY AS DEEP SFC LOW SLOWLY
LIFTS TO JAMES BAY/HUDSON BAY. GRADIENT WEST FLOW STAYS OVER UPR
MICHIGAN...BUT WILL LIGHTEN ENOUGH ON WEDNESDAY TO RESULT IN LAKE
BREEZES. SLIM CHANCE THAT RESULTING LOW-LEVEL CONVERGENCE ADDED TO
WEAK H7-H5 FORCING FM SHORTWAVE DROPPING ACROSS ON PERIFERY OF DEEP
TROUGH ALOFT COULD TRIGGER A FEW SHOWERS/SPRINKLES INTERIOR CENTRAL.
DEEP MIXING TO H8 WILL LIMIT POTENTIAL THOUGH AS LOW-LEVEL RH VALUES
DROP OFF BLO 40 PCT. MAX TEMPS SHOULD PUSH INTO THE 50S INLAND AND
FALL BACK INTO THE 40S NEAR LK SUPERIOR ONCE LAKE BREEZE DEVELOPS.
THE FORECAST FOR THURSDAY INTO FRIDAY REMAINS UNCERTAIN. AT THE
LEAST...TEMPS WILL BE BLO NORMAL FOR MOST CWA...PERHAPS BY MORE
THAN 10-15F OVER THE NORTHERN CWA. ECMWF STILL SUPPORTS POTENTIAL
FOR ACCUMULATING SNOW...NOW MAINLY DELAYED UNTIL THURSDAY NIGHT
THROUGH FRIDAY AND POSSIBLY INTO FRIDAY NIGHT. LATEST UKMET ALSO
IN LINE WITH THE ECMWF IDEA. MEANWHILE...GFS AND GEM-NH STAY WITH
PROGRESSIVE IDEA INDICATING STRONG SHORTWAVE ROUNDING BASE OF DEEP
TROUGH STAYS SEPARATE ENOUGH FROM TROUGH FROM HUDSON BAY TO THE
NORTHERN PLAINS TO LIMIT PHASING. IF GFS THEME IDEA IS RIGHT...WOULD
SEE SETUP WITH MORE DIURNALLY DRIVEN MAINLY RAIN SHOWERS DUE TO
INSTABILITY ALOFT BENEATH THE TROUGH AXIS. IF THE ECMWF AND UKMET
ARE ON THE RIGHT TRACK...THEY INDICATE ENOUGH PHASING BTWN THE LARGE
SCALE TROUGHS TO DRAG A SFC LOW PRESSURE SYSTEM NORTHWARD OVER THE
CNTRL GREAT LAKES INTO TOWARD THE UPPER GREAT LAKES THURSDAY INTO
FRIDAY. WITH THAT SCNEARIO...WIDESPREAD RAIN AND SNOW THURSDAY
EVENING WOULD CHANGE TO SNOW THURSDAY NIGHT INTO MUCH OF FRIDAY AND
NORTHERLY FLOW WOULD ONLY BOOST THE SNOW OVER HIGHER TERRAIN AREAS
NEAR LK SUPERIOR. SNOW COULD BE PRETTY WIDESRPEAD AS PYTPE WITH H85
TEMPS DROPPING BLO -5C AND SINCE 1000-850MB THICKNESSES FALL BLO
1300M. PHASING SYSTEMS ARE ALWAYS TOUGH TO FORECAST. ADD TO THAT
FACT THAT WE ARE PUSHING INTO MIDDLE OF MAY AND IT MAKES IT REALLY
TOUGH TO SAY IF UKMET AND ECMWF SOLUTION WILL WORK OUT AS FORECAST.
SINCE ECMWF ENSEMBLE MEAN WOULD ALSO SUPPORT SIMILAR IDEA AND SOME
CANADIAN ENSEMBLES HAVE SHOWN THIS RECENTLY IT DOES SUGGEST THE IDEA
AT LEAST HAS SOME MERIT COMPARED TO JUST ONE ROUGE OPERATIONAL MODEL
RUN SHOWING A BIG STORM IN THE FAR REACHES OF THE EXTENDED.
ONCE THE SYSTEM OR JUST THE OPEN TROUGH MOVES BY...WEEKEND LOOKS
DRIER WITH GRADUAL WARMING TREND. DID NOT STRAY FROM CONSENSUS LOW
CHANCE POPS FOR NEXT WEEKEND ATTM.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 128 AM EDT MON MAY 12 2014
LINGERING DRY AIR AT THE LOW LEVELS WITH PREVAILING VFR CONDITIONS
ARE EXPECTED TIL LATE IN THE NIGHT. A NORTHWARD MOVING LOW AND A
WARM FRONT WILL SPREAD SHRA INTO UPPER MI...MAINLY AFT 09Z ALTHOUGH
THERE IS STILL SOME UNCERTAINTY IN HOW FAST PCPN WILL DEVELOP. KIWD
HAS THE BEST CHC OF CONDITIONS FALLING TO MVFR OVERNIGHT WITH THE
ONSET OF RAIN. EXPECT ALL SITES TO QUICKLY FALL TO IFR OR LIFR IN
LOWERING STRATUS BY 12Z OR SHORTLY THEREAFTER WITH CONTINUED SHOWERS
AND ADVECTION OF HIGHER DEWPOINTS INTO THE AREA.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 504 AM EDT MON MAY 12 2014
EXPECT PERIOD OF STRONGER WINDS OVER LAKE SUPERIOR. APPROACHING LOW
PRESSURE SYSTEM RESULTS IN NORTHEAST WINDS INCREASING TO GALES BY
AFTN OVER WEST HALF OF LK SUPERIOR. WINDS TO 30 KTS OVER REST OF LK
SUPERIOR. STRONG WINDS DIMINISH BRIEFLY LATER THIS EVENING AND
OVERNIGHT TONIGHT AS THE LOW SLIDES ACROSS WESTERN LK SUPERIOR. ONCE
THE LOW MOVES NORTH OF THE LAKE ON TUESDAY MORNING...STRONG WEST
WINDS KICK UP. EXPECT THESE STRONG WESTERLIES...PROBABLY REACHING
GALES ON TUESDAY OVER NCNTRL LK SUPERIOR...TO SLOWLY FADE BLO 25 KTS
BY WEDNESDAY MORNING. WINDS REST OF THE WEEK WILL MAINLY BE BLO 20
KTS. HOWEVER...A LOW PRESSURE SYSTEM COULD IMPACT THE REGION LATE
THIS WEEK WITH WINDS OVER 25 KTS THURSDAY INTO FRIDAY. UNCERTAINTY
IS HIGH WITH THAT SYSTEM THOUGH...SO CURRENT FORECAST WILL ONLY CALL
FOR NORTHWEST TO 20 KTS AT THIS TIME.
&&
.HYDROLOGY...
ISSUED AT 504 AM EDT MON MAY 12 2014
WIDESRPEAD MODERATE TO HEAVY RAIN WILL AFFECT ALL OF UPR MICHIGAN
THROUGH EARLY THIS AFTN BEFORE DIMINISHING...THEN THERE MAY BE
ANOTHER PERIOD OF MODERATE RAINFALL TONIGHT. RAINFALL AMOUNTS MAY
EXCEED ONE INCH TODAY OVER PORTIONS OF WESTERN UPR MICHIGAN. RAIN
CHANCES DIMINISH FROM WEST TO EAST ON TUESDAY AS A FRONTAL BOUNDARY
EXITS THE REGION. RAINFALL WILL ONLY ADD TO THE ONGOING SNOWMELT AND
ALREADY HIGH FLOWS ON AREA RIVERS AND STREAMS. THE PRIMARY CHANGE TO
ONGOING HEADLINES WAS LAST EVENING...WHEN BASED ON EXPECTED
RAINFALL...WHICH LOOKS LIKE IT IS WORKING OUT...ADVISORIES WERE
UPGRADED TO WARNINGS FOR THE MICHIGAMME RIVER NEAR REPUBLIC AND
WITCH LAKE. THE WARNING FOR THE STURGEON RIVER NEAR CHASSELL AND THE
ADVISORY FOR THE STURGEON RIVER NEAR ALSTON CONTINUE...AS DOES THE
ADVISORY FOR THE MICHIGAMME RIVER DOWNSTREAM OF WAY DAM...TO THE
EAST OF CRYSTAL FALLS IN IRON COUNTY.
GIVEN THE RAINFALL THAT WILL AFFECT THE AREA THE NEXT 24-36
HOURS...RIVER LEVELS WILL KEEP RISING AND ADJUSTMENTS WILL LIKELY BE
NEEDED BASED ON LATEST TRENDS. ALL THIS WATER DUE TO THE SNOWMELT
AND THE RAINFALL WILL TAKE A WHILE TO WORK THROUGH THE RIVERS...SO
IT IS QUITE LIKELY THAT HIGHER RIVER FLOWS AND THE ASSOCIATED
ADVISORIES AND WARNINGS ON AREA RIVERS WILL CONTINUE THROUGH LATE
THIS WEEK...IF NOT INTO NEXT WEEKEND. THOSE LIVING NEAR
RIVERS...CREEKS...AND STREAMS SHOULD CONTINUE TO MONITOR THE LATEST
RIVER LEVELS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL MIDNIGHT EDT /11 PM CDT/ TONIGHT FOR LSZ162.
GALE WARNING FROM 10 AM THIS MORNING TO 11 PM EDT THIS EVENING
FOR LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...JLB
MARINE...JLA
HYDROLOGY...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
505 AM EDT MON MAY 12 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 347 PM EDT SUN MAY 11 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW STRONG SHORTWAVE ENERGY
ROUNDING BASE OF AMPLIFIED TROF OVER THE FOUR CORNERS REGION OF THE
SW CONUS. MODELS SHOW THIS STRONG SHORTWAVE BEGINNING TO EJECT NE
FROM WRN/CENTRAL PLAINS TONIGHT AS ITS ASSOC SFC LOW LIFTS NE
THROUGH THE PLAINS. INCREASING MOISTURE AND ISENTROPIC ASCENT AHEAD
OF THIS LOW PRES SYSTEM SHOULD SIGNAL THE BEGINNING OF A FAIRLY WET
PERIOD FOR THE CWA STARTING LATE TONIGHT AND CONTINUING INTO EARLY
TUESDAY.
TONIGHT...AS THE STRONGER SHORTWAVE BEGINS TO EJECT OUT OF THE
DEEPENING UPPER TROF THE SFC LOW PRES WILL IN TURN LIFT NE THRU THE
PLAINS. THE EVENING SHOULD REMAIN DRY...AND PERHAPS CONTINUE INTO
THE OVERNIGHT OVER THE NE HALF OF THE FCST AREA CLOSER TO DRY
LOW-LEVEL NE TRAJECTORIES OUT OF SFC HIGH PRES IN ONTARIO. MOST OF
THE MODELS SHOW INCREASING 850-700 MB MOISTURE TRANSPORT AND
ADVECTION INTO THE AREA FM THE SOUTH BTWN 06-12Z ALONG WITH
INCREASING 300-305K WAA/ISENTROPIC ASCENT AHEAD OF THE APPROACHING
LOW PRES SYSTEM. MODELS ALSO INDICATE A SUBTLE SHORTWAVE WILL LIFT
NE INTO THE UPPER MISSISSIPPI VALLEY LATE TONIGHT THAT WILL FURTHER
AID THE DEVELOPMENT/SPREAD OF SHRA NE INTO UPPER MI DURING THE
OVERNIGHT. NOT MUCH INSTABILITY IS NOTED PER 0-3KM MUCAPE OFF THE
NAM/GFS. WITH A COUPLE HUNDRED J/KG AND SHOWALTER INDEX FALLING JUST
BLO 0C OVER THE FAR SCNTRL LATE TONIGHT IN MOST MODEL
GUIDANCE...WILL CONTINUE THE MENTION OF THUNDER IN THAT AREA LATE
TONIGHT.
MONDAY...WITH H85 WARM FRONT IN THE VICINITY...MODELS SHOW CONTINUED
MOISTURE TRANSPORT/ADVECTION AT H85-H7 ACROSS THE FRONTAL BOUNDARY
AS PWATS OVER OUR AREA RISE TO AROUND 1.5 INCHES OR WELL OVER 200
PCT OF NORMAL. SHORTWAVE/PV ANAMOLY EMERGING NORTHEAST OUT OF THE
WESTERN CONUS TROUGH WILL SPREAD AREA OF H85-H5 Q-VECTOR CONVERGENCE
INTO THE UPPER GREAT LAKES BY MONDAY AFTERNOON. DESPITE THESE
FAVORABLE FACTORS FOR SHOWERS...MODELS STILL DIFFER SOMEWHAT ON
PLACEMENT OF MAXIMUM MOISTURE ADVECTION...WITH THE GFS AND NAM
INDICATING BEST MOISTURE ADVECTION WEST AND THE REG GEM TO THE
EAST. HOWEVER CORFIDI VECTORS...BOTH FORWARD AND BACKWARD
PROPAGATING...ARE GENERALLY ORIENTED FROM WEST TO EAST ACROSS THE
FCST AREA WHICH WOULD ARGUE SHOWERS MAKING IT INTO THE WRN FCST AREA
SHOULD ADVECT INTO THE ERN COUNTIES AS WELL. GOING FCST LIKELY POPS
STILL SEEM REASONABLE CONSIDERING THE H85 FRONT IS IN THE VICINTY.
WILL CONTINUE IDEA OF LIKELY POPS WEST IN THE MORNING SPREADING EAST
INTO THE AFTERNOON HRS. ALSO WILL CONTINUE TO KEEP MENTION OF
TSRA MAINLY OVER SOUTH HALF INTO THE WESTERN CWA ALONG NORTHERN
GRADIENT OF ELEVATED INSTABILITY WITH SEVERAL HUNDRED J/KG OF
ELEVATED CAPE AND NEG SHOWALTER INDICES. BIGGEST THREAT WITH ANY
TSRA WILL BE HEAVY RAIN GIVEN HIGH PWATS ACROSS AREA. ANY HEAVY RAIN
OVER THE WRN COUNTIES WILL CONTINUE TO ADD MORE RUNOFF TO RIVERS
ALREADY RUNNING NEAR BANKFULL...ESPECIALLY THE STURGEON...TRAP ROCK
AND MICHIGAMME RIVERS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 504 AM EDT MON MAY 12 2014
DEEP TROUGH FOR MAY AND REALLY ANYTIME OF THE YEAR STRETCHES FROM
CENTRAL CANADA TO THE SOUTHERN PLAINS ON TUESDAY. SFC LOW CURRENTLY
OVER THE CENTRAL PLAINS SHOULD BE JUST NORTHWEST OF LK SUPERIOR
DAYBREAK ON TUESDAY. OCCLUDED FRONT WILL BE SLICING ACROSS CWA
THROUGH MID MORNING...EXITING EASTERN CWA BY EARLY AFTN. SHOULD BE AT
LEAST SCT SHRA/TSRA EXPECTED ALONG AND AHEAD OF FRONT AS HIGHER
1000-850MB THETA-E POOLS ALONG THE BOUNDARY. SHARP DRYING ENDS ANY
RAIN QUICKLY OVER WEST HALF IN THE MORNING...BUT MAY SEE ISOLD
SHRA/TSRA OVER FAR SOUTHEAST CWA AS WEAK LOW-LEVEL CONVERGENCE
LINGERS AND AS ANOTHER WEAKER SHORTWAVE/Q-VECTOR CONVERGENCE AT
H85-H5 LIFTS OVER FAR EAST CWA. ANY STORMS AHAEAD OF FRONT IN THE
MORNING SHOULD BE WEAK AS 1-6KM MUCAPE AND MLCAPE BOTH DIMINISH
STEADILY COMPARED TO THE OVERNIGHT HOURS. TEMPS WILL RISE INTO THE
60S OVER THE CNTRL WHERE WEST WINDS DOWNSLOPE...IMT-ESC-MNM...BUT
WILL STAY IN THE 50S OVER THE WESTERN/NORTHWEST CWA WITH GRADIENT
WINDS OFF LK SUPERIOR. THOSE WINDS COULD BE QUITE GUSTY...ESPECIALLY
OVER THE MORE EXPOSED KEWEENAW...WHERE NAM/GFS SOUNDINGS INDICATE
MIXED LAYER BUILDING TO H85-H8 WITH WINDS OVER 35 KTS IN THE MIXED
LAYER.
QUIET WEATHER TUESDAY NIGHT AND WEDNESDAY AS DEEP SFC LOW SLOWLY
LIFTS TO JAMES BAY/HUDSON BAY. GRADIENT WEST FLOW STAYS OVER UPR
MICHIGAN...BUT WILL LIGHTEN ENOUGH ON WEDNESDAY TO RESULT IN LAKE
BREEZES. SLIM CHANCE THAT RESULTING LOW-LEVEL CONVERGENCE ADDED TO
WEAK H7-H5 FORCING FM SHORTWAVE DROPPING ACROSS ON PERIFERY OF DEEP
TROUGH ALOFT COULD TRIGGER A FEW SHOWERS/SPRINKLES INTERIOR CENTRAL.
DEEP MIXING TO H8 WILL LIMIT POTENTIAL THOUGH AS LOW-LEVEL RH VALUES
DROP OFF BLO 40 PCT. MAX TEMPS SHOULD PUSH INTO THE 50S INLAND AND
FALL BACK INTO THE 40S NEAR LK SUPERIOR ONCE LAKE BREEZE DEVELOPS.
THE FORECAST FOR THURSDAY INTO FRIDAY REMAINS UNCERTAIN. AT THE
LEAST...TEMPS WILL BE BLO NORMAL FOR MOST CWA...PERHAPS BY MORE
THAN 10-15F OVER THE NORTHERN CWA. ECMWF STILL SUPPORTS POTENTIAL
FOR ACCUMULATING SNOW...NOW MAINLY DELAYED UNTIL THURSDAY NIGHT
THROUGH FRIDAY AND POSSIBLY INTO FRIDAY NIGHT. LATEST UKMET ALSO
IN LINE WITH THE ECMWF IDEA. MEANWHILE...GFS AND GEM-NH STAY WITH
PROGRESSIVE IDEA INDICATING STRONG SHORTWAVE ROUNDING BASE OF DEEP
TROUGH STAYS SEPARATE ENOUGH FROM TROUGH FROM HUDSON BAY TO THE
NORTHERN PLAINS TO LIMIT PHASING. IF GFS THEME IDEA IS RIGHT...WOULD
SEE SETUP WITH MORE DIURNALLY DRIVEN MAINLY RAIN SHOWERS DUE TO
INSTABILITY ALOFT BENEATH THE TROUGH AXIS. IF THE ECMWF AND UKMET
ARE ON THE RIGHT TRACK...THEY INDICATE ENOUGH PHASING BTWN THE LARGE
SCALE TROUGHS TO DRAG A SFC LOW PRESSURE SYSTEM NORTHWARD OVER THE
CNTRL GREAT LAKES INTO TOWARD THE UPPER GREAT LAKES THURSDAY INTO
FRIDAY. WITH THAT SCNEARIO...WIDESPREAD RAIN AND SNOW THURSDAY
EVENING WOULD CHANGE TO SNOW THURSDAY NIGHT INTO MUCH OF FRIDAY AND
NORTHERLY FLOW WOULD ONLY BOOST THE SNOW OVER HIGHER TERRAIN AREAS
NEAR LK SUPERIOR. SNOW COULD BE PRETTY WIDESRPEAD AS PYTPE WITH H85
TEMPS DROPPING BLO -5C AND SINCE 1000-850MB THICKNESSES FALL BLO
1300M. PHASING SYSTEMS ARE ALWAYS TOUGH TO FORECAST. ADD TO THAT
FACT THAT WE ARE PUSHING INTO MIDDLE OF MAY AND IT MAKES IT REALLY
TOUGH TO SAY IF UKMET AND ECMWF SOLUTION WILL WORK OUT AS FORECAST.
SINCE ECMWF ENSEMBLE MEAN WOULD ALSO SUPPORT SIMILAR IDEA AND SOME
CANADIAN ENSEMBLES HAVE SHOWN THIS RECENTLY IT DOES SUGGEST THE IDEA
AT LEAST HAS SOME MERIT COMPARED TO JUST ONE ROUGE OPERATIONAL MODEL
RUN SHOWING A BIG STORM IN THE FAR REACHES OF THE EXTENDED.
ONCE THE SYSTEM OR JUST THE OPEN TROUGH MOVES BY...WEEKEND LOOKS
DRIER WITH GRADUAL WARMING TREND. DID NOT STRAY FROM CONSENSUS LOW
CHANCE POPS FOR NEXT WEEKEND ATTM.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 128 AM EDT MON MAY 12 2014
LINGERING DRY AIR AT THE LOW LEVELS WITH PREVAILING VFR CONDITIONS
ARE EXPECTED TIL LATE IN THE NIGHT. A NORTHWARD MOVING LOW AND A
WARM FRONT WILL SPREAD SHRA INTO UPPER MI...MAINLY AFT 09Z ALTHOUGH
THERE IS STILL SOME UNCERTAINTY IN HOW FAST PCPN WILL DEVELOP. KIWD
HAS THE BEST CHC OF CONDITIONS FALLING TO MVFR OVERNIGHT WITH THE
ONSET OF RAIN. EXPECT ALL SITES TO QUICKLY FALL TO IFR OR LIFR IN
LOWERING STRATUS BY 12Z OR SHORTLY THEREAFTER WITH CONTINUED SHOWERS
AND ADVECTION OF HIGHER DEWPOINTS INTO THE AREA.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 504 AM EDT MON MAY 12 2014
EXPECT PERIOD OF STRONGER WINDS OVER LAKE SUPERIOR. APPROACHING LOW
PRESSURE SYSTEM RESULTS IN NORTHEAST WINDS INCREASING TO GALES BY
AFTN OVER WEST HALF OF LK SUPERIOR. WINDS TO 30 KTS OVER REST OF LK
SUPERIOR. STRONG WINDS DIMINISH BRIEFLY LATER THIS EVENING AND
OVERNIGHT TONIGHT AS THE LOW SLIDES ACROSS WESTERN LK SUPERIOR. ONCE
THE LOW MOVES NORTH OF THE LAKE ON TUESDAY MORNING...STRONG WEST
WINDS KICK UP. EXPECT THESE STRONG WESTERLIES...PROBABLY REACHING
GALES ON TUESDAY OVER NCNTRL LK SUPERIOR...TO SLOWLY FADE BLO 25 KTS
BY WEDNESDAY MORNING. WINDS REST OF THE WEEK WILL MAINLY BE BLO 20
KTS. HOWEVER...A LOW PRESSURE SYSTEM COULD IMPACT THE REGION LATE
THIS WEEK WITH WINDS OVER 25 KTS THURSDAY INTO FRIDAY. UNCERTAINTY
IS HIGH WITH THAT SYSTEM THOUGH...SO CURRENT FORECAST WILL ONLY CALL
FOR NORTHWEST TO 20 KTS AT THIS TIME.
&&
.HYDROLOGY...
ISSUED AT 504 AM EDT MON MAY 12 2014
WIDESRPEAD MODERATE TO HEAVY RAIN WILL AFFECT ALL OF UPR MICHIGAN
THROUGH EARLY THIS AFTN BEFORE DIMINISHING...THEN THERE MAY BE
ANOTHER PERIOD OF MODERATE RAINFALL TONIGHT. RAINFALL AMOUNTS MAY
EXCEED ONE INCH TODAY OVER PORTIONS OF WESTERN UPR MICHIGAN. RAIN
CHANCES DIMINISH FROM WEST TO EAST ON TUESDAY AS A FRONTAL BOUNDARY
EXITS THE REGION. RAINFALL WILL ONLY ADD TO THE ONGOING SNOWMELT AND
ALREADY HIGH FLOWS ON AREA RIVERS AND STREAMS. THE PRIMARY CHANGE TO
ONGOING HEADLINES WAS LAST EVENING...WHEN BASED ON EXPECTED
RAINFALL...WHICH LOOKS LIKE IT IS WORKING OUT...ADVISORIES WERE
UPGRADED TO WARNINGS FOR THE MICHIGAMME RIVER NEAR REPUBLIC AND
WITCH LAKE. THE WARNING FOR THE STURGEON RIVER NEAR CHASSELL AND THE
ADVISORY FOR THE STURGEON RIVER NEAR ALSTON CONTINUE...AS DOES THE
ADVISORY FOR THE MICHIGAMME RIVER DOWNSTREAM OF WAY DAM...TO THE
EAST OF CRYSTAL FALLS IN IRON COUNTY.
GIVEN THE RAINFALL THAT WILL AFFECT THE AREA THE NEXT 24-36
HOURS...RIVER LEVELS WILL KEEP RISING AND ADJUSTMENTS WILL LIKELY BE
NEEDED BASED ON LATEST TRENDS. ALL THIS WATER DUE TO THE SNOWMELT
AND THE RAINFALL WILL TAKE A WHILE TO WORK THROUGH THE RIVERS...SO
IT IS QUITE LIKELY THAT HIGHER RIVER FLOWS AND THE ASSOCIATED
ADVISORIES AND WARNINGS ON AREA RIVERS WILL CONTINUE THROUGH LATE
THIS WEEK...IF NOT INTO NEXT WEEKEND. THOSE LIVING NEAR
RIVERS...CREEKS...AND STREAMS SHOULD CONTINUE TO MONITOR THE LATEST
RIVER LEVELS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL MIDNIGHT EDT /11 PM CDT/ TONIGHT FOR LSZ162.
GALE WARNING FROM 10 AM THIS MORNING TO 11 PM EDT THIS EVENING
FOR LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...JLA
AVIATION...JLB
MARINE...JLA
HYDROLOGY...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
128 AM EDT MON MAY 12 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 347 PM EDT SUN MAY 11 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW STRONG SHORTWAVE ENERGY
ROUNDING BASE OF AMPLIFIED TROF OVER THE FOUR CORNERS REGION OF THE
SW CONUS. MODELS SHOW THIS STRONG SHORTWAVE BEGINNING TO EJECT NE
FROM WRN/CENTRAL PLAINS TONIGHT AS ITS ASSOC SFC LOW LIFTS NE
THROUGH THE PLAINS. INCREASING MOISTURE AND ISENTROPIC ASCENT AHEAD
OF THIS LOW PRES SYSTEM SHOULD SIGNAL THE BEGINNING OF A FAIRLY WET
PERIOD FOR THE CWA STARTING LATE TONIGHT AND CONTINUING INTO EARLY
TUESDAY.
TONIGHT...AS THE STRONGER SHORTWAVE BEGINS TO EJECT OUT OF THE
DEEPENING UPPER TROF THE SFC LOW PRES WILL IN TURN LIFT NE THRU THE
PLAINS. THE EVENING SHOULD REMAIN DRY...AND PERHAPS CONTINUE INTO
THE OVERNIGHT OVER THE NE HALF OF THE FCST AREA CLOSER TO DRY
LOW-LEVEL NE TRAJECTORIES OUT OF SFC HIGH PRES IN ONTARIO. MOST OF
THE MODELS SHOW INCREASING 850-700 MB MOISTURE TRANSPORT AND
ADVECTION INTO THE AREA FM THE SOUTH BTWN 06-12Z ALONG WITH
INCREASING 300-305K WAA/ISENTROPIC ASCENT AHEAD OF THE APPROACHING
LOW PRES SYSTEM. MODELS ALSO INDICATE A SUBTLE SHORTWAVE WILL LIFT
NE INTO THE UPPER MISSISSIPPI VALLEY LATE TONIGHT THAT WILL FURTHER
AID THE DEVELOPMENT/SPREAD OF SHRA NE INTO UPPER MI DURING THE
OVERNIGHT. NOT MUCH INSTABILITY IS NOTED PER 0-3KM MUCAPE OFF THE
NAM/GFS. WITH A COUPLE HUNDRED J/KG AND SHOWALTER INDEX FALLING JUST
BLO 0C OVER THE FAR SCNTRL LATE TONIGHT IN MOST MODEL
GUIDANCE...WILL CONTINUE THE MENTION OF THUNDER IN THAT AREA LATE
TONIGHT.
MONDAY...WITH H85 WARM FRONT IN THE VICINITY...MODELS SHOW CONTINUED
MOISTURE TRANSPORT/ADVECTION AT H85-H7 ACROSS THE FRONTAL BOUNDARY
AS PWATS OVER OUR AREA RISE TO AROUND 1.5 INCHES OR WELL OVER 200
PCT OF NORMAL. SHORTWAVE/PV ANAMOLY EMERGING NORTHEAST OUT OF THE
WESTERN CONUS TROUGH WILL SPREAD AREA OF H85-H5 Q-VECTOR CONVERGENCE
INTO THE UPPER GREAT LAKES BY MONDAY AFTERNOON. DESPITE THESE
FAVORABLE FACTORS FOR SHOWERS...MODELS STILL DIFFER SOMEWHAT ON
PLACEMENT OF MAXIMUM MOISTURE ADVECTION...WITH THE GFS AND NAM
INDICATING BEST MOISTURE ADVECTION WEST AND THE REG GEM TO THE
EAST. HOWEVER CORFIDI VECTORS...BOTH FORWARD AND BACKWARD
PROPAGATING...ARE GENERALLY ORIENTED FROM WEST TO EAST ACROSS THE
FCST AREA WHICH WOULD ARGUE SHOWERS MAKING IT INTO THE WRN FCST AREA
SHOULD ADVECT INTO THE ERN COUNTIES AS WELL. GOING FCST LIKELY POPS
STILL SEEM REASONABLE CONSIDERING THE H85 FRONT IS IN THE VICINTY.
WILL CONTINUE IDEA OF LIKELY POPS WEST IN THE MORNING SPREADING EAST
INTO THE AFTERNOON HRS. ALSO WILL CONTINUE TO KEEP MENTION OF
TSRA MAINLY OVER SOUTH HALF INTO THE WESTERN CWA ALONG NORTHERN
GRADIENT OF ELEVATED INSTABILITY WITH SEVERAL HUNDRED J/KG OF
ELEVATED CAPE AND NEG SHOWALTER INDICES. BIGGEST THREAT WITH ANY
TSRA WILL BE HEAVY RAIN GIVEN HIGH PWATS ACROSS AREA. ANY HEAVY RAIN
OVER THE WRN COUNTIES WILL CONTINUE TO ADD MORE RUNOFF TO RIVERS
ALREADY RUNNING NEAR BANKFULL...ESPECIALLY THE STURGEON...TRAP ROCK
AND MICHIGAMME RIVERS.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 329 PM EDT SUN MAY 11 2014
AT THE START OF THE PERIOD /00Z TUE/ MODELS ARE IN DECENT LARGE
SCALE AGREEMENT IN SHOWING A SHARP AND DEEP 500MB TROUGH FROM THE
SASK/MANITOBA BORDER S ACROSS THE DAKOTAS THEN TO THE FOUR CORNERS
REGION. A 1004MB SFC LOW WILL BE SOMEWHERE IN THE SERN MN TO NWRN
WI. MODELS HAVE BEEN TRENDING TOWARD THE CURRENT SOLUTION THAT TAKES
THE SFC LOW W OF THE CWA TO JUST N OF THE MN ARROWHEAD BY 12Z TUE.
WITH THE MORE NLY TRACK...MODELS ARE NOW SHOWING THE SFC WARM FRONT
MOVING INTO THE FAR SRN CWA MON NIGHT...BUT WITH COLD LAKE TEMPS AND
CONVECTION EXPECTED ALONG THE FRONT...CONFIDENCE IN THE FRONT MOVING
THAT FAR N IS LOW. FORCING FROM UPPER LEVEL HEIGHT FALLS FROM THE
DEEPENING TROUGH...GOOD MOISTURE TRANSPORT AND ISENTROPIC ASCENT
WILL FAVOR PERIODS OF MODERATE RAIN SHOWERS MON NIGHT INTO EARLY
TUE. THE OCCLUDED/COLD FRONT WILL MOVE THROUGH FROM LATE MON NIGHT
INTO TUE...BRINGING AN END TO THE BULK OF THE PRECIP. SOME SHOWERS
COULD REDEVELOP BEHIND THE FRONT AS CLEARING OVER THE WRN U.P. MAY
ALLOW FOR ENOUGH INSTABILITY. MODELS GENERALLY SHOW ADDITIONAL QPF
AMOUNTS OF AN INCH...BUT THAT WILL BE HIGHLY DEPENDENT ON EXACT
DETAILS OF CONVECTION...MAKING EXACT PRECIP AMOUNTS HIGHLY
UNCERTAIN. INSTABILITY FOR CONVECTION WILL ALSO BE HIGHLY UNCERTAIN
DUE TO DEPENDENCY ON WARM FRONTAL LOCATION AND OTHER CONVECTION. IF
THE FRONT CAN MAKE IT FARTHER N...THE WARM NOSE AT 900MB MAY BE
STRONG ENOUGH TO LEAD TO GREATER ELEVATED CONVECTION. GFS AND NAM
ARE SHOWING UP TO AROUND 1000 J/KG OF ELEVATED CAPE OVER THE
SCENTRAL CWA...BUT STILL THINK THAT IS NOT AS LIKELY AS THE FRONT
WILL PROBABLY STAY FARTHER S. IF THE WORST CASE SCENARIO OF THE
FARTHER N FRONTAL POSITION DOES OCCUR...SOME HAIL WOULD BE POSSIBLE
SCENTRAL. THE ADDITIONAL QPF AMOUNTS /COMBINED WITH PRECIP ON MON/
WOULD LIKELY LEAD TO ADDITIONAL FLOODING CONCERNS ON AREA RIVERS
THAT ALREADY HAVE ELEVATED LEVELS.
THE UPPER TROUGH MOVES OVERHEAD THROUGH MUCH OF THE REST OF THE WORK
WEEK...ALTHOUGH THE ECMWF CLOSES IT OFF INTO A LOW THU INTO FRI. THE
ECMWF SOLUTION WOULD RESULT IN MORE WIDESPREAD PRECIP THU INTO
FRI...BUT THE GFS AND GEM SOLUTIONS WITH THE OPEN TROUGH WOULD LEAD
TO SCATTERED SHOWER ACTIVITY MAINLY DURING PEAK HEATING WED THROUGH
FRI. THIS DUE TO 850MB TEMPS OF -2C TO -4C WED THROUGH FRI NIGHT
/AND AS COLD AS -7C IF THE ECMWF SOLUTION PANS OUT/. OF
COURSE...THIS WILL LEAD TO A RETURN OF SIGNIFICANTLY BELOW NORMAL
TEMPS /10-15 DEGREES BELOW NORMAL/.
NEXT WEEKEND LOOKS DRIER AND WARMER AS RIDGING MOVES OVERHEAD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 128 AM EDT MON MAY 12 2014
LINGERING DRY AIR AT THE LOW LEVELS WITH PREVAILING VFR CONDITIONS
ARE EXPECTED TIL LATE IN THE NIGHT. A NORTHWARD MOVING LOW AND A
WARM FRONT WILL SPREAD SHRA INTO UPPER MI...MAINLY AFT 09Z ALTHOUGH
THERE IS STILL SOME UNCERTAINTY IN HOW FAST PCPN WILL DEVELOP. KIWD
HAS THE BEST CHC OF CONDITIONS FALLING TO MVFR OVERNIGHT WITH THE
ONSET OF RAIN. EXPECT ALL SITES TO QUICKLY FALL TO IFR OR LIFR IN
LOWERING STRATUS BY 12Z OR SHORTLY THEREAFTER WITH CONTINUED SHOWERS
AND ADVECTION OF HIGHER DEWPOINTS INTO THE AREA.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 347 PM EDT SUN MAY 11 2014
NE WINDS 15-25 KTS THIS EVENING WILL BEGIN TO INCREASE OVER WESTERN
PORTIONS OF LK SUPERIOR LATE TONIGHT AND MORE SO ON MONDAY AS LOW
PRESSURE APPROACHES FROM THE SOUTHWEST. DECIDED TO REPLACE GALE
WATCH WITH GALE WARNING OVER WESTERN TWO ZONES LATE TONIGHT THROUGH
TUE EVENING. WINDS OVER THE REST OF THE LAKE WILL STAY AT OR BLO 30
KTS. WINDS DIMINISH LATER MONDAY NIGHT AND THEN SWITCH TO THE WEST
TO 20-25 KTS ON TUESDAY. LOW SLOWLY SLIDES TO THE NORTHEAST OF LK
SUPERIOR REST OF THE WEEK...RESULTING IN NORTHWEST WINDS MAINLY
STAYING BLO 20 KTS.
&&
.HYDROLOGY...
ISSUED AT 329 PM EDT SUN MAY 11 2014
HIGHS MOSTLY IN THE 60S TODAY WILL RESULT IN ADDITIONAL SNOWMELT
OVER HIGHER TERRAIN OF NORTHERN UPR MICHIGAN. MINIMAL RAIN AMOUNTS
ARE EXPECTED THROUGH AT LEAST EARLY TONIGHT...BUT RAIN CHANCES
INCREASE LATE TONIGHT INTO TUESDAY MORNING. THERE IS A POTENTIAL FOR
MODERATE TO HEAVY RAIN OVER THE AREAS THAT ARE STILL MELTING
SNOW...SO THE RECENT HIGHER RIVER LEVELS WILL CONTINUE THROUGH MUCH
OF THE UPCOMING WEEK. THE FLOOD WARNING CONTINUES FOR THE STURGEON
RIVER NEAR CHASSELL...WHILE ADVISORIES ARE IN PLACE FOR OTHER
PORTIONS OF THE STURGEON RIVER IN HOUGHTON AND BARAGA COUNTIES AS
WELL AS PORTIONS OF THE MICHIGAMME RIVER. IF HEAVIER RAINS
MATERIALIZE EARLY THIS WEEK... ADDITIONAL ADVISORIES AND WARNINGS
MAY BE NEEDED. THOSE LIVING NEAR RIVERS...CREEKS...AND STREAMS
SHOULD CONTINUE TO MONITOR THE LATEST RIVER LEVELS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 6 AM EDT /5 AM CDT/ THIS MORNING TO MIDNIGHT
EDT /11 PM CDT/ TONIGHT FOR LSZ162.
GALE WARNING FROM 10 AM THIS MORNING TO 11 PM EDT THIS EVENING
FOR LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...TITUS
AVIATION...JLB
MARINE...VOSS
HYDROLOGY...TITUS
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
421 AM CDT MON MAY 12 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 334 AM CDT MON MAY 12 2014
SHOWERS ARE PUSHING EAST OF OUR WEST CENTRAL WI COUNTIES EARLY THIS
MORNING WITH JUST A FEW SCATTERED SHOWERS ACROSS THE MN COUNTIES.
RAINFALL AMOUNTS OVERNIGHT FROM 1 TO 1.50 INCHES HAVE BEEN COMMON
ACROSS SOUTHERN MN AND ADJOINING AREAS OF WEST CENTRAL WI. RAINFALL
AMOUNTS DROP OFF TO AROUND A HALF INCH FROM WEST CENTRAL MN TO NW
WI.
THE DAY AHEAD WILL FEATURE A LOW PRESSURE SYSTEM MOVING SLOWLY
NORTHEAST FROM IA TO THE SOUTHERN TWIN CITIES METRO BY EARLY THIS
AFTERNOON. THE LOW SHOULD REACH FAR NORTHERN WI BY LATE THIS
EVENING. THERE IS PLENTY OF POTENTIAL FOR SEVERE STORMS TO DEVELOP
THIS AFTERNOON/EVENING IN THE VICINITY OF THE SURFACE LOW AND WARM
FRONT EXTENDING TO THE EAST. LIMITING FACTORS WILL BE THE EXTENSIVE
CLOUDINESS THAT WILL HOLD DOWN ON THE DESTABILIZATION. RAP DATA
SHOWS A WARM POCKET MOVING NORTHEAST FROM IA THIS MORNING BETWEEN
650-700MB. THIS IS SQUARELY OVER WEST CENTRAL WI EARLY THIS
AFTERNOON. LOW LEVEL LAPSE RATES SUFFER AS WELL AS SURFACE BASED
CAPE. HOWEVER...BY LATE IN THE AFTERNOON...SOUNDING DATA FOR KEAU
SHOWS THE POTENTIAL TO WARM ENOUGH TO GET PAST THE MID LEVEL WARM
POCKET. SURFACE BASED CAPE REACHES A LITTLE MORE THAN 2000 J/KG.
SHEAR IS ADEQUATE WITH 0-1KM REACHING 25 KNOTS WITH 0-6KM BETTER
THAN 45 KNOTS. 500MB WINDS ARE VERY IMPRESSIVE WITH A CORE OF 60-70
KNOT WINDS PROGGED ACROSS THE TWIN CITIES AND WEST CENTRAL WI THIS
AFTERNOON. OUR MPXWRF...THE HOPWRF AND THE SPCWRF START BREWING
TROUBLE ALONG OUR MN/WI BORDER AREA BY 21Z WITH THE HINT OF A FEW
SUPERCELLS ACROSS WEST CENTRAL WI INTO THE EARLY EVENING. GIVEN THE
LOW LCLS...SHEAR AND WARM FRONT...A TORNADO OR TWO CAN NOT BE RULED
OUT. IN FACT...THERE HAVE BEEN TORNADOES THE PAST TWO DAYS NEAR THE
SURFACE LOW AND WARM FRONT.
NORTHWEST WINDS WILL STRENGTHEN ACROSS THE FA TONIGHT IN THE WAKE OF
THE LOW PRESSURE SYSTEM. THIS WILL USHER IN MUCH COOLER AIR THAT
WILL BE WITH US FOR THE BALANCE OF THE WEEK AS A LARGE TROUGH ALOFT
DOMINATES ACROSS THE MISSISSIPPI VALLEY REGION.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 334 AM CDT MON MAY 12 2014
THE THEME FOR THE LONG TERM PERIOD IS DRY WEATHER FOR THE UPPER
MIDWEST. ALTHOUGH...IT WILL ALSO BE A COOL PERIOD MAINLY TUESDAY
THROUGH FRIDAY AS TEMPERATURES WILL RUN 10 TO 15 DEGREES BELOW
NORMAL.
PICKING UP TUESDAY MORNING...THE UPPER LEVEL TROUGH AXIS WILL BE IN THE
VICINITY OF THE WESTERN MN/EASTERN DAKOTAS BORDER. THE SURFACE LOW
WILL HAVE LIFTED UP INTO ONTARIO NORTH OF LAKE SUPERIOR. THE NAM
REMAINS STUBBORN IN HAVING THE MOVEMENT OF THE LOW A TAD
SLOWER/GIVEN ITS DEEPER SOLUTION WITH THE TROUGH MONDAY
NIGHT/...BUT IT HAS STARTED TO MOVE TOWARD THE GFS/EC SOLUTIONS.
PREFERRED A EC/GFS BLEND THAT HAS THE LOW QUICKLY MOVING NORTH.
THE UPPER TROUGH AND MOISTURE ON THE BACK SIDE OF THE LOW
WARRANTED THE MENTION OF POPS ACROSS THE NORTHERN PART OF THE
FA...BUT ANY PRECIPITATION WILL BE VERY LIGHT. WITH THE UPPER
TROUGH OVERHEAD...TEMPERATURES WILL BE HELD IN THE 50S DURING THE
DAY...AND WITH THE DEPARTING LOW NORTHWEST WINDS WILL BE BLUSTERY
AND MAKE FOR A COOL DAY. WINDS SHOULD SLACKEN AND SKY COVER BEGIN
TO BREAK UP TUESDAY EVENING. 850H TEMPS WILL FALL BELOW ZERO
OVERNIGHT AND GIVEN WEAKENING WINDS AND AND DIMINISHING SKY COVER
OVERNIGHT...TEMPERATURES BY EARLY WEDNESDAY MORNING WILL BE IN THE
30S ACROSS THE FA. LITTLE CHANGE IS EXPECTED WEDNESDAY AS THE
AMPLIFIED UPPER TROUGH AND CORE OF THE COOL AIR REMAINS OVERHEAD.
MEANWHILE...BOTH THE EAST COAST AND WEST COAST WILL HAVE HIGHLY
AMPLIFIED RIDGING AND WARM TEMPERATURES. SLIGHT CHANCE POPS DO
SHOW UP AGAIN WEDNESDAY AFTERNOON ACROSS THE WEST AS ADDITIONAL
MOISTURE ALOFT ROTATES SOUTH ON THE BACK SIDE OF THE UPPER TROUGH.
WOULD NOT BE SURPRISED IF LOW LEVEL DRY AIR PREVENTS ANYTHING FROM
REACHING THE GROUND. WEDNESDAY NIGHT WILL BE COLDER AS 850H TEMPS
DROP TO -2C TO -6C GENERALLY ACROSS THE FA. WIDESPREAD 30S ARE
EXPECTED WITH SOME SPOTS HITTING THE FREEZING MARK.
THE AMPLIFIED TROUGH WILL PUSH SLIGHTLY EAST AND BECOME A CLOSED
UPPER LOW OVER WISCONSIN THURSDAY NIGHT INTO FRIDAY SO
CYCLONICALLY CURVED FLOW MAY AGAIN PRODUCE VERY LIGHT PRECIP
THURSDAY AFTERNOON. THE POPS ASSOCIATED WITH THIS TROUGH DURING
THE MIDWEEK MAY BE OVERDONE BY THE LARGE SCALE SYNOPTIC
MODELS...HOWEVER...SO WHILE THERE ARE SOME POPS IN THE FORECAST
FOR THE MIDWEEK TIME FRAME...TOTAL AMOUNTS WILL BE UNDER A TENTH OF
AN INCH...AND WILL LIKELY BE ZERO FOR PARTS OF THE AREA.
WE`LL SEE THE CORE OF THE COOL AIR ALOFT PUSH EAST AT THE START OF
THE WEEKEND AS THE WESTERN CONUS RIDGE STARTS PUSHING INTO THE
CENTER OF THE COUNTRY BY SUNDAY. BESIDES A COOL START...THE
WEEKEND LOOKS DRY...PARTLY CLOUDY...AND WARMER THAN THE COLD MIDWEEK
AHEAD. BEYOND THE WEEKEND...THE RIDGE AXIS WILL PUSH OVER OUR AREA
EARLY NEXT WEEK AND TEMPERATURES WILL CONTINUE TO WARM.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1221 AM CDT MON MAY 12 2014
RAIN WITH EMBEDDED TSTMS SPREAD ACROS ENTIRE COVERAGE AREA...
ALTHOUGH BACK EDGE HAS ENTERED SWRN MN AND IS PROGRESSING NEWD.
HAVE TRIED TO TIME THIS BACK EDGE ACRS ALL TAF SITES DURING THE
FIRST PORTION OF THE 12/06Z TAF SET. CEILINGS HAVE STEADILY
LOWERED...AND ONCE THE PRECIP ENDS...AM LOOKING FOR CIGS TO DROP
INTO IFR RANGE DUE TO LOW LEVEL MOISTURE CAUSING LOW STRATUS
DEVELOPMENT. WITH WINDS NOT GOING CALM...STAYING CLOSE TO 5 KT
OVERNIGHT EVEN WHEN GOING VRBL IN ERN MN INTO WRN WI...NOT LOOKING
FOR ANYTHING WORSE THAN MVFR VSBY. THERE LOOKS TO BE A SECOND
BATCH OF -RA FOR LATE TMRW MRNG INTO TMRW AFTN. THERE ARE ENOUGH
QUESTIONS REGARDING CONVECTIVE POTENTIAL SO HAVE OPTED TO OMIT ITS
MENTION ATTM...BUT WILL ANALYZE LATEST MODELS AND DETERMINE IF
CONVECTION NEEDS TO BE ADDED TO LATER TAFS. WINDS FROM THE E AND
SE WILL GO VRBL ARND DAYBREAK THEN ALL SITES WILL SWING TO THE W
AND NW THIS AFTN AND REMAIN THERE THRU THE EVE. SUSTAINED SPEEDS
WILL INCRS TO 10-15 KT WITH GUSTS NEAR 25 KT THIS AFTN AND EVE
BEFORE SLIGHTLY DIMINISHING THIS EVE.
KMSP...VFR CONDS TO START DESPITE WIDESPREAD -RA WITH A FEW
TSRA...MAINLY S AND E OF MSP. STILL MAY BE POCKETS OF MOD/HVY RAIN
IN THE FIRST COUPLE OF HRS THAT WILL DROP VSBY INTO IFR RANGE.
ONCE THE RAIN EXITS...LOW STRATUS WITH MVFR VSBY WILL PREVAIL FOR
THE REST OF THE EARLY MRNG HRS THRU ARND NOON. THEN THE NEXT
BATCH OF RAIN WILL PUSH THRU...SLIGHTLY IMPROVING CONDITIONS AS
THE RAIN HELPS WASH OUT SOME OF THE LOW LEVEL MOISTURE. AFTER THIS
BATCH...THEN THE IFR CEILINGS ARE EXPECTED TO REDEVELOP. THAT
SAID...CEILINGS SUB-1700 FT WILL LIKELY PREVAIL FOR MUCH OF THE
TAF PERIOD STARTING OVERNIGHT AND PERSISTING THRU THE REST OF
THIS TAF PERIOD.
/OUTLOOK FOR KMSP/
TUE...MVFR POSSIBLE. SLGT CHC -SHRA. WINDS W-NW 15-20 KTS.
WED...MVFR POSSIBLE. SLGT CHC -SHRA. WINDS W-NW 5-15 KTS.
THU...MVFR POSSIBLE. SLGT CHC -SHRA. WINDS NW 5-15 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...RAH
LONG TERM...SPD
AVIATION...JPC
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1240 AM CDT MON MAY 12 2014
.UPDATE...
ISSUED AT 1221 AM CDT MON MAY 12 2014
UPDATED TO INCLUDE 06Z AVIATION DISCUSSION BELOW.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 355 PM CDT SUN MAY 11 2014
EARLY AFTERNOON WATER VAPOR IMAGERY TOGETHER WITH RAP 500MB
HEIGHTS AND WINDS IDENTIFIED A VIGOROUS SHORTWAVE ROTATING OVER
THE 4-CORNERS REGION...WITH AN MCS ONGOING IN EASTERN IA. VISIBLE
SATELLITE SHOWED CLEARING BEHIND THIS MCS...AND THE SURFACE OBS
HAVE ALREADY REFLECTED THE BOUNDARY LAYER DESTABILIZATION AS
TEMPERATURES HAVE INCREASED 5DEG/HR BUT KEPT THE EASTERLY
COMPONENT IN THE WIND FIELD.
THIS WIND SHIFT MARKED THE STOUT FRONTAL BOUNDARY WHICH WILL
BE THE FOCUS FOR TORNADOES LATER THIS AFTERNOON ACROSS EASTERN NE
AND WESTERN IA. TEMPERATURES WERE IN THE MID 80S SOUTH OF THIS
WARM FRONT WITH SOUTHERLY WINDS...WHILE NORTH OF THE WARM FRONT
TEMPERATURES WERE IN THE LOW TO MID 70S WITH DEWPOINTS IN THE MID
60S. THE MLCAPE GRADIENT MIRRORED THE POSITION OF THE EAST/WEST
ORIENTED WARM FRONT...BUT INSTABILITY WAS BUILDING WELL NORTH OF
THE FRONT AS EVIDENT BY THE 3HR SBCAPE CHANGE ON THE SPC
MESOANALYSIS PAGE. THE FINAL POSITION OF THE WARM FRONT WILL
DICTATE WHERE THE SURFACE BASED STORMS ARE...AND THUS THE BEST
THREAT FOR TORNADOES. AT THIS TIME IT APPEARS THAT THE THREAT WILL
REMAIN WELL SOUTH OF THE CWA.
HOWEVER...THE LAST FEW RUNS OF THE HRRR AND HOPWRF INDICATE THAT A
FEW ELEVATED STORMS ARE EXPECTED AFTER 00Z ACROSS THE SOUTHERN
PART OF THE FORECAST AREA. THESE STORMS WILL HAVE 1000-1500J/KG OF
MUCAPE TO WORK WITH DEEP SHEAR FAVORABLE FOR ORGANIZED CONVECTION.
A FEW STORMS WILL HAVE THE POTENTIAL FOR PRODUCE SEVERE
HAIL...MAINLY ALONG THE I-90 CORRIDOR. HEAVY RAIN IS ALSO A
THREAT...PERHAPS MORESO THAN THE SEVERE WEATHER. AT THIS TIME...IT
APPEARS THAT THE HEAVIEST RAINFALL WILL FALL JUST SOUTH AND EAST
OF THE FORECAST AREA ALONG A LINE FROM OMAHA TO LA CROSSE WI. IT
IS WITHIN THIS LINE THAT A HP SUPERCELLS ARE EXPECTED WHICH WILL
BE CAPABLE OF PRODUCING 2-3IN/HR RAINFALL RATES AND FLASH FLOODING
GIVEN THE RAINFALL THAT OCCURRED EARLIER THIS MORNING. IN OUR
CWA...WE DID NOT HAVE THE MORNING RAINFALL...AND SUPERCELLS APPEAR
LESS LIKELY...SO ALTHOUGH WE MAY GET A QUICK 1-2 INCHES OF RAIN
WITH A FEW OF THE HEAVIER CELLS...THIS IS ABOVE FLASH FLOOD
GUIDANCE. THEREFORE HAVE OPTED TO HOLD OFF ON A FLOOD WATCH FOR
NOW. TO TIE BACK INTO THE HIRES MODELS...THE PROGRESSIVE NATURE OF
THE EASTWARD MOVING STORMS ALSO SUPPORTS NOT ISSUING A FLOOD
WATCH.
THERE WILL BE A LULL IN THE PRECIP ACROSS CENTRAL MN AS THE
SURFACE LOW TRACKS NORTHEASTWARD OVERNIGHT. MEANWHILE LIGHT RAIN
WILL CONTINUE ACROSS THE WESTERN CWA IN THE DEFORMATION AREA OF
THE UPPER LEVEL WAVE. FORECAST MODELS SHOW THE POTENTIAL FOR SOME
CONVECTION REDEVELOPING IN THE WARM SECTOR OF THE SURFACE LOW
ACROSS EASTERN MN AND WESTERN WI...SO TRIED TO REFLECT THAT IN THE
AFTERNOON POP GRIDS. THESE STORMS DO HAVE THE POTENTIAL TO BE
SEVERE.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 355 PM CDT SUN MAY 11 2014
NOT MUCH IN THE WAY OF CHANGE TO THE EXTENDED PORTION OF THE
FORECAST...WITH THE UPCOMING WEEK BEING MARKED BY COOL
TEMPERATURES AND PERIODIC SCATTERED LIGHT SHOWERS AS A DEEPLY
AMPLIFIED LONGWAVE TROUGH PIVOTS ACROSS THE UPPER MIDWEST AND
GREAT LAKES REGIONS.
THE BEGINNING OF THE LONG TERM PERIOD /MONDAY NIGHT/ WILL FEATURE
RAIN SHOWERS WINDING DOWN AS THE LOW LIFTS TO LAKE SUPERIOR.
ADDITIONAL RAINFALL AMOUNTS SHOULD BE AROUND A COUPLE TENTHS OF AN
INCH OR LESS.
TUESDAY THROUGH FRIDAY BRINGS CYCLONIC FLOW WITH COOLER THAN
NORMAL TEMPERATURES AND THE POTENTIAL FOR OCCASIONAL SCATTERED
SHOWERS AS THE TROUGH BLANKETS THE REGION. HIGHS WILL BE IN THE
50S AND LOWS WILL DIP INTO THE LOWER 30S AND 40S. THE POTENTIAL
FOR FROST LOOKS TO BE TUESDAY THROUGH THURSDAY NIGHTS.
TEMPERATURES MODERATE NEXT WEEKEND AS WESTERN UPPER RIDGING BUILDS
INTO THE CENTRAL CONUS. HIGHS IN THE 60S LOOK LIKE A GOOD BET FOR
NEXT WEEKEND...ALTHOUGH A FEW SHOWERS MAY BE LURKING ON SUNDAY IF
THE ECMWF SOLUTION VERIFIES /WHICH INDICATES A TROUGH WILL BUST
IN FROM THE PACIFIC NORTHWEST AND BREAK DOWN THE RIDGE/.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1221 AM CDT MON MAY 12 2014
RAIN WITH EMBEDDED TSTMS SPREAD ACROS ENTIRE COVERAGE AREA...
ALTHOUGH BACK EDGE HAS ENTERED SWRN MN AND IS PROGRESSING NEWD.
HAVE TRIED TO TIME THIS BACK EDGE ACRS ALL TAF SITES DURING THE
FIRST PORTION OF THE 12/06Z TAF SET. CEILINGS HAVE STEADILY
LOWERED...AND ONCE THE PRECIP ENDS...AM LOOKING FOR CIGS TO DROP
INTO IFR RANGE DUE TO LOW LEVEL MOISTURE CAUSING LOW STRATUS
DEVELOPMENT. WITH WINDS NOT GOING CALM...STAYING CLOSE TO 5 KT
OVERNIGHT EVEN WHEN GOING VRBL IN ERN MN INTO WRN WI...NOT LOOKING
FOR ANYTHING WORSE THAN MVFR VSBY. THERE LOOKS TO BE A SECOND
BATCH OF -RA FOR LATE TMRW MRNG INTO TMRW AFTN. THERE ARE ENOUGH
QUESTIONS REGARDING CONVECTIVE POTENTIAL SO HAVE OPTED TO OMIT ITS
MENTION ATTM...BUT WILL ANALYZE LATEST MODELS AND DETERMINE IF
CONVECTION NEEDS TO BE ADDED TO LATER TAFS. WINDS FROM THE E AND
SE WILL GO VRBL ARND DAYBREAK THEN ALL SITES WILL SWING TO THE W
AND NW THIS AFTN AND REMAIN THERE THRU THE EVE. SUSTAINED SPEEDS
WILL INCRS TO 10-15 KT WITH GUSTS NEAR 25 KT THIS AFTN AND EVE
BEFORE SLIGHTLY DIMINISHING THIS EVE.
KMSP...VFR CONDS TO START DESPITE WIDESPREAD -RA WITH A FEW
TSRA...MAINLY S AND E OF MSP. STILL MAY BE POCKETS OF MOD/HVY RAIN
IN THE FIRST COUPLE OF HRS THAT WILL DROP VSBY INTO IFR RANGE.
ONCE THE RAIN EXITS...LOW STRATUS WITH MVFR VSBY WILL PREVAIL FOR
THE REST OF THE EARLY MRNG HRS THRU ARND NOON. THEN THE NEXT
BATCH OF RAIN WILL PUSH THRU...SLIGHTLY IMPROVING CONDITIONS AS
THE RAIN HELPS WASH OUT SOME OF THE LOW LEVEL MOISTURE. AFTER THIS
BATCH...THEN THE IFR CEILINGS ARE EXPECTED TO REDEVELOP. THAT
SAID...CEILINGS SUB-1700 FT WILL LIKELY PREVAIL FOR MUCH OF THE
TAF PERIOD STARTING OVERNIGHT AND PERSISTING THRU THE REST OF
THIS TAF PERIOD.
/OUTLOOK FOR KMSP/
TUE...MVFR POSSIBLE. SLGT CHC -SHRA. WINDS W-NW 15-20 KTS.
WED...MVFR POSSIBLE. SLGT CHC -SHRA. WINDS W-NW 5-15 KTS.
THU...MVFR POSSIBLE. SLGT CHC -SHRA. WINDS NW 5-15 KTS.
&&
.HYDROLOGY...
ISSUED AT 355 PM CDT SUN MAY 11 2014
AT THIS TIME RIVER FLOODING APPEARS TO BE THE PRIMARY CONCERN
MAINLY IN WESTERN WI AND THE MAINSTEM OF THE MISSISSIPPI RIVER.
ANOTHER ROUND OF 1 TO 2 INCHES OF BASIN-WIDE RAINFALL IS EXPECTED
OVER THE NEXT 24 HRS. AT THIS TIME...THE THREAT FOR THE HEAVIEST
RAIN AND FLASH FLOODING APPEARS TO BE ACROSS IOWA...SO NOT
ANTICIPATING ANY FLASH FLOODING IN MN OR WI. IF IT WERE TO
HAPPEN...IT WOULD BE IN FAR SOUTHERN MN. LASTLY, IF THE FORECAST
RAINFALL AMOUNTS TREND HIGHER THAN CURRENTLY EXPECTED...THE
FLOODING POTENTIAL WILL INCREASE AS WELL.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
UPDATE...JPC
SHORT TERM...JRB
LONG TERM...LS
AVIATION...JPC
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
346 AM CDT Mon May 12 2014
.SHORT TERM: (Today and Tonight)
Issued at 330 AM CDT Mon May 12 2014
Main forecast issues for today are the probability of thunderstorms
and any severe potental, as well as just how warm it may get.
Current thinking is there should be a gradual upswing in convection
as the day progresses, primarily during the later half of the
afternoon. It appears that northeast Missouri will be the area we
will have to watch most closely through mid morning. Two things to
key an eye on - an outflow boundary pushing southeastward across
eastern Iowa as a focus for additional thunderstorms, and also a
cluster of thunderstorms across eastern Kansas just southwest of
Kansas City and if they will hold together as they move northeastward.
Otherwise I think that there will be a general decrease in the
convective cloud debris during the morning, which given the mild
early morning temperatures should allow for a quick warm-up by
early afternoon. The convection allowing models and more
specifically the HRRR is suggesting that by mid morning, isolated
showers or thunderstorms could develop just about anywhere within
the CWA, but most favored across southeast Missouri and southern
Illinois. The main action still looks like the later half of the
afternoon. The warm sector air mass ahead of the cold front will
become quite unstable by mid-late afternoon with SBCAPE in excess
of 2000 J/KG and little CIN. Expecting numerous thunderstorms to
develop across western Missouri into central and northeast
Missouri. Deep layer shear of 20-30 kts and the anticipated CAPE
would support a few severe storms capable of large hail and
damaging winds from the afternoon into about mid-evening. The
front moves through all but the far eastern sections of the CWA
tonight accompanied by widespread showers and thunderstorms and
ushering much cooler air into the region in its wake. It also
appears that there will be an increasing amount of post-frontal
showers overnight immediately in the cool air in response to large
scale forcing.
Glass
.LONG TERM: (Tuesday through Sunday)
Issued at 330 AM CDT Mon May 12 2014
This marks the beginning of a cooler than normal period with a
slow-moving and deep upper trof dominating the region through the
week. The front will quickly exit the remainder of the CWA early
Tuesday morning with post-frontal showers impacting eastern
Missouri and southwest Illinois in the morning and exiting by
early-mid afternoon. Highs on Tuesday will be around 20 degrees
cooler than today. A strong short-wave and possibly upper low will
then migrate through the base of the deep trof from the southern
Plains and into the mid MS valley Tuesday night-Wednesday night.
More reminiscent of Fall or early Spring, large scale ascent with this
system should produce a large area of showers or rain spreading
into the area late Tuesday night into Wednesday. Its northward
extent and longevity is all dependent on the strength of the
system, and NAM featuring a closed low and large deformation zone, has
the greatest northward push and keeps precipitation well into
Wednesday night. Regardless the precipitation and accompanying
overcast low clouds will keep temperatures well below average on
Wednesday. We could continue to see a periodic shower threat
through the end of the week as we get into deeper cyclonic flow on
the backside of the slow-moving deep upper trof. Temperatures will
remain below average into at least Friday.
Glass
&&
.AVIATION: (For the 06z TAFs through 06z Monday Night)
Issued at 1136 PM CDT Sun May 11 2014
Expecting VFR flight conditions to prevail across most of the area
for the rest of the night. Low level wind shear conditions will
spread further than previously thought; probably as far east as
southwest Illinois. Have included LLWS in all terminal forecasts.
Thunderstorms over Iowa are trying to spread a bit further south
into northern Missouri, however most guidance agrees that storms
will be weakening as they get far enough east to threaten our
area. Some widely scattered showers or storms may develop as
diurnal heating increases during the late morning or early
afternoon, but the primary threat for thunderstorms will be during
the late afternoon and evening ahead of the cold front. Guidance
seems to be in good agreement that there will be a line of storms
marching eastward from western Missouri in the afternoon, reaching
eastern Missouri by early evening. With these high precipitation
chances in guidance, feel it`s ok to go ahead and star TEMPOs in
the terminal forecasts.
Specifics for KSTL:
VFR flight conditions are expected to continue at Lambert tonight.
Low level wind shear looks to spread further east than previously
forecast with 45kt or higher winds around 1500-2000ft, so have
included it until 12Z. The guidance suite seems to be in good
agreement that the storms over Iowa won`t spread south to affect
Lambert through the morning, but there may be some widely
scattered showers or storms developing during the late morning or
early afternoon. Think coverage will be pretty low though so have
not mentioned it in this update. The primary threat for
thunderstorms will come during the early evening ahead of a cold
front. While timing is still uncertain, it looks very likely that
Lambert will receive a period of thunderstorms in the early
evening followed by lighter rain later in the evening/overnight.
Carney
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
130 AM EDT MON MAY 12 2014
.SYNOPSIS...
HIGH PRESSURE OFFSHORE WILL MAINTAIN WELL ABOVE NORMAL TEMPERATURES
THROUGH THE MIDDLE OF THE UPCOMING WEEK. A COLD FRONT WILL
APPROACH THURSDAY BEFORE CROSSING OFFSHORE ON FRIDAY...BRINGING A
GOOD CHANCE FOR SHOWERS AND THUNDERSTORMS. COOLER TEMPERATURES
WILL DEVELOP IN THE WAKE OF THIS COLD FRONT INTO NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF 1045 PM SUNDAY...RIDGING ALOFT AND ITS AXIS NEARLY
OVERHEAD...WILL AMPLIFY-SOME ACROSS THE BI-STATE REGION OVERNIGHT
AND INTO THE SHORT TERM PERIOD. THIS WILL DEFLECT ANY S/W TROFS
ALOFT TO THE WEST AND NORTH OF THE FA. AT THE SFC...MODEST HIGH
PRESSURE CENTERED OFFSHORE AND EAST OF THE CAROLINAS...WILL RIDGE
BACK ACROSS THE REGION...AND PREVAIL GOING INTO THE SHORT TERM
PERIOD. FOR THE REMAINDER OF THIS EVENING AND OVERNIGHT...THE
DIURNALLY INDUCED CONVECTION HAS DISSIPATED LEAVING A FEW OUTFLOW
BOUNDARIES ACROSS PORTIONS OF THE FA GOING INTO DAYLIGHT MONDAY.
WITH THE MAJORITY OF THE LEFTOVER CONVECTIVE CLOUDINESS
DISSIPATING...A SFC BASED INVERSION SHOULD DEVELOP COURTESY OF THE
HOURLY NAMBUFR SOUNDINGS. LOW LEVEL STRATUS BELOW 1K FEET WILL
DEVELOP ACROSS THE FA VIA LATEST HRRR MODEL RUNS. MIN TEMPS HAVE
BEEN MASSAGED UPWARDS ESPECIALLY WITH LOW LEVEL STRATUS OVERTAKING
THE FA AND SFC DEWPOINTS REMAINING WELL INTO THE 60S ACROSS THE
MAJORITY OF THE FA. PATCHY TO AREAS OF FOG WILL ALSO BE ADVERTISED
ACROSS THE FA...FOR MAINLY THE HOURS BETWEEN MIDNIGHT TO JUST AFTER
SUNRISE. COULD BE ONE OF THOSE NIGHTS WHERE LOW LEVEL STRATUS AND FOG
DUEL WITH ONE ANOTHER IN SEEING WHO WILL PREVAIL OVER THE OTHER.
PREVIOUS DISCUSSION............................................
AS OF 300 PM SUNDAY...ISOLATED TO WIDELY SCATTERED SHOWERS ARE
BREAKING OUT ACROSS THE FORECAST AREA EARLY THIS AFTERNOON. SO FAR
HAVE NOTED ONLY ONE BRIEF THUNDERSTORM OVER COASTAL GEORGETOWN
COUNTY. WITH A MODERATELY UNSTABLE ATMOSPHERE AND MOIST LOW LEVELS
EXPECT THIS ACTIVITY TO CONTINUE FOR THE REMAINDER OF THE
AFTERNOON AND INTO THE EARLY EVENING.
BOTH GFS AND NAM INDICATE COLUMN MOISTURE BECOMING MORE SHALLOW
AFTER SUNSET AND WITH AN UPPER RIDGE BUILDING IN SEE LITTLE CHANCE
FOR SIGNIFICANT OVERNIGHT PRECIPITATION. SO...AS THIS ACTIVITY
SEEMS DIURNALLY DRIVEN WITH NO STRONG FORCING MECHANISM
PRESENT...EXPECT CONVECTION TO FADE WITH THE SETTING SUN AND TO BE
OVER WITH BY MIDNIGHT.
HAVE CONTINUED RECENT TREND OF FORECASTING MINIMUM TEMPERATURES A
FEW DEGREES ABOVE GUIDANCE. THIS METHOD HAS BEEN VERIFYING WELL
AGAINST GUIDANCE RECENTLY AND GIVES US OVERNIGHT MINIMUMS IN THE
MID 60S FOR MOST PLACES.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...SUMMERTIME PATTERN AMPLIFIES DURING THE
BEGINNING OF THE WEEK THANKS TO A STRENGTHENING 5H RIDGE. THIS WILL
DRIVE TEMPERATURES WELL INTO THE 80S TO AROUND 90 MONDAY AND TUESDAY
AWAY FROM THE COAST...WITH LOW 80S ANTICIPATED AT THE BEACHES. THESE
VERY WARM TEMPS...COMBINED WITH STILL COOL OCEAN TEMPS...AND A WEAK
GRADIENT BOTH AT THE SURFACE AND ALOFT...SHOULD ALLOW DECENT INLAND
PENETRATION OF THE SEA BREEZE BOTH DAYS. THIS WILL HAVE ONLY LIMITED
IMPACT ON HIGHS THOUGH SINCE TEMPS WILL SOAR QUICKLY DURING LATE
MORNING EARLY AFTN...THANKS TO LOWS ONLY FALLING INTO THE MID/UPR
60S...70 AT THE COAST.
MORE QUESTIONABLE PORTION OF THE FORECAST INVOLVES CONVECTIVE
POTENTIAL THROUGH EARLY WEEK. GUIDANCE IS STUBBORNLY DEPICTING
SCATTERED SHOWERS/TSTMS BOTH MONDAY AND TUESDAY AFTNS...FOCUSED
PRIMARILY ON THE SEA BREEZE. SPC HAS GENERAL RISK ACROSS THE AREA
BOTH DAYS AS WELL. AM STRUGGLING TO FIND REASONS TO INCLUDE
CONVECTION IN THE FORECAST...OTHER THAN DEWPOINTS WELL INTO THE 60S
AND STEEP SURFACE-BASED LAPSE RATES. HOWEVER...PRETTY MUCH
EVERYTHING ELSE POINTS TO THE NEXT TWO DAYS BEING DRY. 500MB RIDGE
AXIS SITS NEARLY OVERHEAD...PROVIDING A SUBSIDENT LID WITH VERY WEAK
MID-LEVEL LAPSE RATES. 700MB RIDGE REMAINS ANCHORED OVERHEAD AS
WELL...FORCING ANY MOISTURE AROUND TO THE WEST OF THE AREA...WHICH
IS ALSO ECHOED BY WEAK 850-700MB MOISTURE TRANSPORT VECTORS AND
DRYING FORECAST SOUNDINGS. LCL`S ARE AT THE TOP OF WHATEVER RESIDUAL
MOIST LAYER EXISTS MONDAY AND TUESDAY...SO UPDRAFTS SHOULD SUFFER
FROM SIGNIFICANT DRY AIR ENTRAINMENT...FURTHER LIMITING CONVECTIVE
POTENTIAL. STILL...INHERITED HAS SCHC MONDAY AND SURROUNDING WFO`S
HAVE AT LEAST THAT...SO WILL KEEP SCHC MONDAY FOR ISOLATED
SHOWERS...BUT DROP POP TO SILENT ON TUESDAY.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 300 PM SUNDAY...THE BIG WEATHER MAKER IN THE LONG TERM WILL BE
AN EASTWARD-MOVING COLD FRONT THURSDAY...PUSHED ALONG BY A FULL
LATITUDE UPPER TROUGH EXTENDING FROM HUDSON BAY TO THE GULF COAST.
THE WESTERN EXTENSION OF THE BERMUDA HIGH WILL COVER THE AREA
WEDNESDAY. RELATIVELY STABLE ONSHORE WINDS AND PLENTY OF DRY AIR
ASSOCIATED WITH THE DEEP-LAYER RIDGING SHOULD KEEP THINGS MOSTLY
SUNNY AND DRY WITH HIGHS IN THE UPPER 80S INLAND AND AROUND 80 ON
THE BEACHES. PRESSURES WILL BEGIN TO FALL WEDNESDAY NIGHT AS THE
AFOREMENTIONED FRONT CROSSES THE LOWER MISSISSIPPI VALLEY.
INCREASING SOUTHERLY FLOW WILL BEGIN TO MOISTEN OUR AIRMASS...AND
PRECIPITABLE WATER VALUES SHOULD CLIMB FROM AROUND 1 INCH WEDNESDAY
TO 1.5 INCHES BY LATE WEDNESDAY NIGHT.
INTEGRATED COLUMN MOISTURE PEAKS JUST AHEAD OF THE FRONT THURSDAY
EVENING WITH PW VALUES NEAR 1.9 INCHES. 850 MB WINDS DO NOT BECOME
PARTICULARLY STRONG...20-30 KT DEPENDING ON YOUR MODEL...AND
KINEMATIC FIELDS ARE NOT OVERLY CONCERNING FOR A SEVERE WEATHER
RISK. GIVEN MODEST FORECAST INSTABILITY (CAPE 1000-1500 J/KG) AND
SUCH MOIST SOUNDINGS THE LARGEST CONCERN COULD BE LOCALLY HEAVY RAIN
AND PERHAPS A WET DOWNBURST IN STRONGER CELLS.
THE BULK OF THE LATEST OPERATIONAL MODEL RUNS SHOW THE COLD FRONT
PUSHING ACROSS THE EASTERN CAROLINAS THURSDAY NIGHT...HOWEVER THE
12Z CANADIAN AS WELL AS ABOUT 25% OF THE 00Z & 06Z GFS ENSEMBLE
MEMBERS ARE SLOWER MOVING THE BOUNDARY OFF THE COAST. I HAVE
THEREFORE MAINTAINED A 30-40 POP INTO FRIDAY. DRY WEATHER SHOULD
ALMOST CERTAINLY DEVELOP BY FRIDAY EVENING LASTING INTO SATURDAY AS
HIGH PRESSURE BUILDS OVER THE CAROLINAS. THE MOST NOTABLE FEATURE
ABOUT THIS INCOMING AIRMASS WILL BE HOW MILD TEMPERATURES WILL BE
COMPARED TO WHAT WE HAVE EXPERIENCED THE PAST WEEK. WITH 850 MB
TEMPS PROGGED +8C TO +10C BOTH FRIDAY AND SATURDAY...HIGHS SHOULD
REMAIN IN THE UPPER 70S FOR MOST AREAS WITH LOWS IN THE 50S.
BY NEXT SUNDAY BOTH THE GFS AND ECMWF SHOW THE TRAILING END OF A
POTENT UPPER LEVEL DISTURBANCE MOVING ACROSS THE CAROLINAS. EVEN
WITH NO LOW-LEVEL GULF OR ATLANTIC INFLOW...MODELS SHOW ENOUGH
PACIFIC MOISTURE COMING ACROSS AT AND ABOVE 850 MB THAT A 30 POP FOR
SHOWERS APPEARS WARRANTED.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 06Z...EXPECT IFR CIGS/VSBYS ACROSS THE CWA TONIGHT AS NEARLY
CALM CONDITIONS PROMOTE FOG AND STRATUS. WIDESPREAD STRATUS AND SOME
FOG WAS ALREADY OCCURRING ACROSS THE COASTAL TAF SITES...PRODUCING
IFR OR LOWER CONDITIONS. WE EXPECT THESE SAME CONDITIONS WILL
OVERSPREAD KLBT AND KFLO THROUGH 08Z.
CONDITIONS SHOULD IMPROVE TO VFR BY 13Z OR SO...WITH LIGHT AND VRB
WINDS EARLY BECOMING SOUTH AOB 10 KT IN THE AFTERNOON. FCST
SOUNDINGS SHOW A LOT OF DRY MID-LEVEL AIR DURING THE DAY...SO
CONVECTION SHOULD BE ISOLATED AT BEST AS DIURNAL CU BUILDS WITH
DAYTIME HEATING.
EXTENDED OUTLOOK...EARLY MORNING MVFR/IFR FOG/STRATUS IS POSSIBLE
THROUGH THURSDAY. OTHERWISE VFR CONDITIONS WILL PREVAIL THROUGH
WEDNESDAY. SHOWERS/TSTMS EXPECTED THURSDAY THROUGH EARLY FRIDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1045 PM SUNDAY...ORIENTATION OF THE SFC RIDGE AXIS EXTENDING
ACROSS THE AREA WATERS FROM THE HIGHS CENTER OFFSHORE AND EAST OF
THE CAROLINAS...WILL DETERMINE WIND DIRECTIONS. AT THIS
POINT...MODELS INDICATE WINDS BECOMING SW-WSW NORTH OF LITTLE
RIVER INLET...AND S TO SSW SOUTH OF THIS INLET. THIS TO OCCUR
AFTER THE DEMISE OF THE SEA BREEZE CIRCULATION. THE LOOSE SYNOPTIC
SFC PRESSURE GRADIENT WILL KEEP WIND SPEEDS AT OR BELOW 10 KT.
SIGNIFICANT SEAS WILL RUN 2 TO OCCASIONALLY 3 FT...AND MAINLY BE
COMPRISED OF WIND DRIVEN WAVES WITH PERIODS OF 5 TO 6 SECONDS. AT
THIS POINT...THE 11 TO 13 SECOND PERIOD EASTERLY GROUND SWELL
REMAINS NEGLIGIBLE FOR ANY INPUT INTO THE SIGNIFICANT SEAS.
PREVIOUS DISCUSSION..........................
AS OF 300 PM SUNDAY...MANAGEABLE MARINE CONDITIONS EXPECTED.
EXPECT A LIGHT SW WIND FLOW ACROSS THE WATERS THROUGH TONIGHT.
SEAS GENERALLY 2-3 FEET...IN A MIX OF SSW WAVES 1-2 FEET EVERY 4-5
SEC AND SE WAVES 1-2 FT EVERY 7-8 SECONDS. ISOLATED TSTMS ARE
POSSIBLE NEAR SHORE THIS AFTERNOON INTO THIS EVENING...AND THE
MOTION WILL BE FROM SW TO NE.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...PRIMARILY UNIFORM WIND/WAVE CONDITIONS DURING
THE SHORT TERM AS BERMUDA HIGH PRESSURE SITS OFFSHORE INTO MID-WEEK.
RETURN FLOW AROUND THIS HIGH PRODUCES SW WINDS OF 10-15 KTS DURING
THE DAY...AND 5-10 KTS AT NIGHT. THE EXCEPTION WILL BE IN THE
NEAR-SHORE WATERS WHERE A SEA BREEZE WILL CAUSE WINDS TO GUST UP TO
20 KTS FOR A FEW HOURS EACH AFTN/EVE. THESE WINDS COMBINED WITH THE
LONG FETCH AROUND THE HIGH PRESSURE WILL BUILD SEAS TO 2-3 FT
THROUGH THE PERIOD...WITH A 5 SEC S/SW WIND WAVE AND A 7 SEC SE
GROUND SWELL COMPRISING THE SPECTRUM.
LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 300 PM SUNDAY...HIGH PRESSURE JUST OFFSHORE WEDNESDAY
SHOULD PROVIDE GENTLE ONSHORE WINDS AND DRY WEATHER. MOISTURE WILL
INCREASE THURSDAY AHEAD OF A COLD FRONT...EXPECTED TO MOVE OFF THE
COAST FRIDAY MORNING. THIS FRONT SHOULD BE PRECEDED BY WAVES OF
SHOWERS AND EMBEDDED THUNDERSTORMS...ESPECIALLY LATE THURSDAY
AFTERNOON INTO THURSDAY NIGHT. ONCE THE FRONT MOVES FARTHER
OFFSHORE FRIDAY... CLEARING CONDITIONS ARE EXPECTED ALONG WITH
BREEZY NORTH TO NORTHWEST WINDS. AT THIS TIME IT APPEARS
CONDITIONS SHOULD REMAIN BELOW ADVISORY THRESHOLDS...ALTHOUGH
WINDS BOTH AHEAD OF AND BEHIND THE FRONT COULD APPROACH 20 KNOTS
SOUTHEAST OF CAPE FEAR WHERE SEA SURFACE TEMPERATURES ARE
CURRENTLY HIGHEST.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...DCH/REK
SHORT TERM...JDW
LONG TERM...TRA
AVIATION...BJR/RJD
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1214 AM CDT MON MAY 12 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 347 PM CDT SUN MAY 11 2014
COMPLEX FORECAST CONTINUES THIS AFTERNOON INTO THE OVERNIGHT.
CURRENT ANALYSIS SHOWS SURFACE LOW PRESSURE OVER WESTERN KANSAS.
KIND OF A DUAL WARM FRONT SIGNATURE. WITH MAIN AND STRONGEST WARM
FRONT ACROSS FAR SOUTHERN NEBRASKA INTO SOUTHWEST IOWA...WHICH WAS
REINFORCED BY THE OVERNIGHT MCS. MODELS IN GOOD AGREEMENT WITH THE
POSITION OF THIS FRONT...AND ALL GUIDANCE SUGGESTS IT WILL ONLY
SLOWLY MOVE NORTH TODAY. THIS IS THE AREA...SOUTHEASTERN NEBRASKA
INTO SOUTHWESTERN IOWA...AT GREATEST RISK FOR SEVERE WEATHER AND
TORNADOES...AS HIGHLIGHTED BY THE SPC OUTLOOK. FURTHER NORTH WE HAVE
A SECONDARY WARM FRONT RUNNING FROM THE TRIPLE POINT OVER SOUTHERN
NEBRASKA...NORTHEAST TO JUST SOUTH OF STORM LAKE. MARGINAL SURFACE
INSTABILITY IS BEGINNING TO FORM IN THIS AREA...ALTHOUGH MOST OF IT
IS REMAINING SOUTH OF OUR CWA. ALSO LARGE SCALE LIFT INCREASING ON
THE NOSE OF A PV WAVE IS HELPING TO TRIGGER ELEVATED SHOWERS AND
THUNDERSTORMS ACROSS THE NORTHWEST HALF OF THE CWA. THESE SHOULD
STAY BELOW SEVERE LIMITS AND PUSH NORTH OF THE AREA BY THIS EVENING.
DAYTIME HEATING AND INCREASING FORCING HAS ALSO HELPED FIRE
CONVECTION ACROSS SOUTH CENTRAL NEBRASKA. THE STRONGEST SURFACE
BASED SUPERCELLS WILL LIKELY RIDE FROM NEAR THE SOUTHERN WARM FRONT
TO THE SECONDARY WARM FRONT...AND THUS STAY SOUTH OF OUR CWA.
ALTHOUGH WILL NEED TO WATCH AREAS FROM SIOUX CITY TO STORM LAKE. LOW
LEVELS REMAIN STABLE...BUT ENOUGH DESTABILIZATION IS POSSIBLE FOR
STORMS MOVING INTO THIS AREA TO TAP INTO THE NEAR SURFACE LAYER. IF
THIS HAPPENED AN ISOLATED TORNADO WOULD BE POSSIBLE. WHILE THIS
STILL SEEMS TO BE A LOW THREAT...IT IS NOT IMPOSSIBLE AND WILL NEED
TO MONITOR TRENDS. SEEMS MORE LIKELY THAT STORMS THAT FORM AND MOVE
INTO OUR CWA WILL STAY ELEVATED...BASED ABOVE THE LOW LEVEL STABLE
LAYER. DECENT ELEVATED INSTABILITY SHOULD INCREASE AND COULD MAKE IT
ALL THE WAY TO ALMOST THE JAMES RIVER. QUESTION IS HOW MUCH MOISTURE
WE CAN GET ADVECTED INTO THE CWA...WITH THE CONVECTION TO OUR SOUTH
HAMPERING THIS TO A DEGREE. SEEMS LIKE A GOOD BET THAT NORTHWEST
IOWA AND SOUTHWEST MINNESOTA WILL GET INTO THE ACTION...LESS CERTAIN
FURTHER NORTHWEST. WITH THE ELEVATED WARM FRONT WELL TO OUR
NORTH...EVEN PARCELS LIFTED FROM NEAR 750 MB SHOULD HAVE AROUND 40
KTS OF SHEAR TO WORK WITH. SO THOUGHT IS ELEVATED SUPERCELLS WILL BE
POSSIBLE IF WE CAN GET THE MOISTURE AND ELEVATED INSTABILITY INTO
THE AREA. MAIN THREAT WOULD BE LARGE HAIL WITH ANY STORM. AGAIN
HIGHEST SEVERE THREAT SHOULD BE ACROSS NORTHWEST IOWA AND ADJACENT
AREAS OF SOUTHWEST MINNESOTA WHERE CONFIDENCE IS HIGHEST ON
INSTABILITY...THREAT IS MORE CONDITIONAL TOWARDS INTERSTATE 29. DO
LIKE THE HRRR IDEA OF PUSHING EVERYTHING EAST BY LATER THIS EVENING
AS STORMS ORGANIZE AND HELP PUSH THE FRONT EATS OF THE CWA. STILL
COULD BE SOME SCATTERED SHOWERS...BUT MOST OF THE OVERNIGHT MAY END
UP FREE OF HEAVY RAIN.
ANOTHER PUSH OF THETAE ADVECTION LATE TONIGHT INTO EARLY MONDAY AS
THE WHOLE SYSTEM BEGINS MOVING NORTHEAST. PRETTY GOOD LARGE SCALE
LIFT TOO AS A STRONG JET ROUNDS THE BASE OF THE TROUGH. THUS
THINKING PRECIPITATION COVERAGE WILL RAPIDLY INCREASE LATER TONIGHT
INTO TOMORROW. MOST OF THIS WEST OF THE JAMES RIVER WILL BE MORE
STABLE SHOWERY PRECIPITATION. DOES LOOK LIKE ELEVATED INSTABILITY
WILL REMAIN TO THE EAST...THUS SHOULD GET SOME THUNDER OUT OF THE
ACTIVITY. MAYBE EVEN SOME MARGINALLY SEVERE HAIL LATE TONIGHT INTO
MONDAY MORNING GIVEN THE WIND PROFILES IF ENOUGH INSTABILITY IS
PRESENT. ANY SURFACE BASED SEVERE WEATHER SHOULD STAY EAST OF THE
CWA. SO OVERALL MONDAY LOOKS LIKE A PRETTY WET DAY WITH HIGHS IN THE
40S AND 50S. WINDS WILL BE ON THE INCREASE AS WELL...WITH AROUND 35
KTS AT 925 MB. WILL BE VERY CLOSE TO WIND ADVISORY CRITERIA ALONG
AND WETS OF THE JAMES RIVER...WITH GUSTS APPROACHING 40 KTS. GIVEN
EXPECTED WEAK MIXING DUE TO THE RAIN AND MARGINAL WINDS ALOFT...WILL
HOLD OFF ON AN ADVISORY FOR NOW.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 347 PM CDT SUN MAY 11 2014
IN THE LONGER TERM...THE WEATHER IS HIGHLIGHTED BY MUCH BELOW
NORMAL TEMPERATURES FOR A BULK OF THE UPCOMING WEEK. FOR MONDAY
NIGHT...DECIDED TO RAISE POPS TO A LOW END LIKELY CATEGORY IN SOME
OF OUR WESTERN ZONES. ALTHOUGH THE GFS IS DRY BY MONDAY EVENING...
THE HIGHER RESOLUTION MODELS DO HANG BACK DEEPER RESIDUAL MOISTURE
IN OUR FORECAST AREA...ESPECIALLY FOR LOCATIONS WEST OF I 29. IN
ADDITION...BOTH THE NAM AND GFS SHOW TROWALING MONDAY EVENING IN
THE 305-315K LAYER. STILL...RAINFALL WILL BE LIGHT EVEN IN OUR
WESTERN ZONES...WITH OUR EASTERN ZONES NOT SEEING MUCH OF A
RAINFALL POTENTIAL. ALTHOUGH COOL...THE CLOUD COVER AND WIND WILL
HELP OUR LOWS FROM PLUMMETING TOO FAR MONDAY NIGHT WITH READINGS
MOSTLY A COUPLE OF DEGREES EITHER SIDE OF 40.
THEN THE UPPER LOW BEGINS TO MEANDER ACROSS SOUTHERN CANADA AND
THE NORTHERN MS VALLEY ALL THE WAY FROM TUESDAY THROUGH THURSDAY...
EVENTUALLY LIFTING INTO THE WESTERN GREAT LAKES BY FRIDAY.
THEREFORE VERY CHILLY WEATHER FOR THIS TIME OF YEAR WILL FOLLOW
SUIT. EVEN THE BIAS CORRECTED TEMPERATURES ARE NOW COLD...AND THEY
HAVE BEEN THE BEST RECENTLY IN OUR FORECAST AREA IN CAPTURING WARM...
MIXED OUT TEMPERATURES DURING THE DAYTIME. INSTABILITY CU WILL
POP ON TUESDAY WITH A STRONG UPPER CYCLONIC FLOW EXISTING...WITH A
SMALL CHANCE FOR LIGHT SHOWERS AROUND BROOKINGS AND SOUTHWEST MN.
AFTER SUNSET...SKIES WILL CLEAR TUESDAY NIGHT FOLLOWED BY SOME
MORE INSTABILITY DAYTIME CU ON WEDNESDAY...AND THERE ARE STRONG
INDICATIONS THAT A SHORT WAVE WILL DIVE DOWN THE NORTHWEST FLOW
ALOFT GIVING THE POSSIBILITY OF MORE WIDELY SCATTERED LIGHT
SHOWERS ACROSS THE ENTIRE FORECAST AREA. BUT LOW POPS ARE STILL
WARRANTED AS A QUESTION EXISTS AS TO HOW MUCH OF THIS RAINFALL
WILL ACTUALLY MEASURE. ULTIMATELY...THIS SHORT WAVE WILL REINFORCE
THE PARENT UPPER LOW AND KEEP OUR CYCLONIC FLOW GOING WITH A FEW
SHOWERS AGAIN POSSIBLE ON THURSDAY.
AS MENTIONED ABOVE...TUESDAY THROUGH THURSDAY WILL BE COLD WITH
HIGHS ONLY IN THE 50S TO AROUND 60. FURTHERMORE...MIXED LAYER
WINDS ARE STOUT ON TUESDAY PROMISING BREEZY CONDITIONS...LESS SO
ON WEDNESDAY BUT STILL THE WIND WILL BE STRONG ENOUGH TO GIVE A
RATHER RAW DAY.
ONE THING TO WATCH FOR BOTH TUESDAY NIGHT AND WEDNESDAY NIGHT AS
SKIES CLEAR AFTER SUNSET AND WINDS SUBSIDE...IS THE POSSIBILITY OF
FROST HERE AND THERE. DID NOT PUT THEM IN THE GRIDS YET...AND
CERTAINLY DID NOT ISSUE ANY FROST HEADLINES. BUT SOME OF OUR LOWS
DO FALL INTO THE MID 30S SO WOULD NOT BE SURPRISED TO SEE SOME
LIGHT FROST IN LOW LYING AREAS.
FURTHER OUT FRIDAY THROUGH SUNDAY...THE UPPER LOW FINALLY MOVES
INTO THE GREAT LAKES...THE NORTH OF THE GREAT LAKES ALLOWING THE
FLOW TO BECOME QUASI ZONAL. THERE MAY BE SOME WARM AIR ADVECTION
SHOWERS ON SUNDAY AS THE NEXT UPPER TROUGH BEGINS TO DIG DOWN THE
WESTERN U.S. COAST. THEREFORE HIGHS WILL FINALLY WARM UP INTO THE
60S FRIDAY THROUGH SUNDAY WITH LOWS ALSO MODERATING.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1204 AM CDT MON MAY 12 2014
WIDESPREAD SHOWERS AND STORMS HAVE MOVED EAST OF THE AREA...HOWEVER
COULD SEE AN ADDITIONAL CLUSTER OF SHOWERS AND STORMS MOVE ACROSS OUR
FAR SOUTHEAST COUNTIES...INCLUDING KSUX THROUGH AROUND 09Z. ANOTHER
BAND OF RAINFALL IS EXPECTED TO LIFT ACROSS SOUTHEAST SOUTH
DAKOTA...WITH MORE SCATTERED COVERAGE INTO SOUTHWEST MINNESOTA AFTER
07Z. ALONG WITH OCCASIONAL RAINFALL...MVFR TO IFR CEILINGS ARE
EXPECTED TO SPREAD NORTHEAST...BECOMING WIDESPREAD OVERNIGHT. THESE
CEILINGS WILL STICK AROUND THROUGH THE DAY ON MONDAY AND COULD BEGIN
LIFTING ACROSS THE WEST AFTER 00Z TUESDAY...POSSIBLY ALSO NEAR THE
MISSOURI VALLEY...INCLUDING KHON AND KSUX. WINDS WILL BE GUSTY FROM
THE NORTHWEST THROUGHOUT THE PERIOD...AVERAGING 15 TO 25 KT WITH
GUSTS AS HIGH AS 35 KT.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...CHENARD
LONG TERM...MJ
AVIATION...
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
442 AM CDT MON MAY 12 2014
.SHORT TERM...
(Today and Tonight)
WV imagery this morning was showing and a strong upper level trough
over the central and southern Rockies with a mid level speed max of
50 to 70 knots rotating out in the Plains. Upper level flow has
backed to southwest over Texas. Also, a lot mid and upper subsidence
evident which is still resulting in a strong cap over West Central
Texas. At the surface, a cold front was located along a Quanah to
Seminole line. A dryline extended south along a Wink to Sanderson
line. Not much happening yet convection wise as low level inhibition
and cap is still holding strong. A few showers have developed just
behind the cold front across northwest Texas. The airmass was very
moist across our area with southerly flow and dewpoints in the mid
to upper 60s.
For today, the chance of showers and thunderstorms will increase mid
morning through the afternoon across mainly the eastern half of the
CWFA. The cold front will continue southeast into West Central Texas
and will probably slow its forward speed. Scattered showers and
thunderstorms will develop along and behind the front as elevated
instability erases the cap. The HRRR convective allowing model is
showing best coverage of activity east of an Abilene to San Angelo
line. The combination of good instability in the warm sector and
weak 0-6KM shear of 25 to 30 knots will result in multicell storms
with possible brief supercell structures. A few strong to severe
storms are possible across mainly the Heartland and Northwest Hill
Country. The main hazards will be large hail, damaging winds and
dangerous cloud to ground lightning. Going with mainly chance to
slight chance POPS for today. Temperatures will be cooler with highs
in the 80s.
For tonight, There will be a chance of showers thunderstorms across
much of our area with better coverage of storms east of a Coleman to
Sonora line. a few storms may be severe. The main hazards will be
large hail, damaging winds and dangerous cloud to ground lightning
mainly before 06Z Tuesday. The bigger focus will be the potential
for locally heavy rainfall across the Heartland and Northwest Hill
Country, due to good low level southerly flow. moisture flux
convergence along a slow moving cold front, PWAT values of 1.5 to
1.75 inches and in the RRQ of highly amplified 250MB jet. Rainfall
amounts of 1 to 2 inches with locally heavy amounts are possible
along and east of a Brownwood to Junction line. Also, going with
LKLY to CAT POPS across the southeast CWFA.
.LONG TERM...
(Tuesday through next Monday)
The cold front will be well south of the area early Tuesday morning,
with the upper level trough axis over New Mexico. Showers and
thunderstorms may be ongoing across far southeast sections early
Tuesday morning but will move east of the area by mid to late
morning. Additional showers and isolated thunderstorms will be
possible across much of the area during the day as lift increases
ahead of the approaching upper trough. Moisture will be limited, so
precipitation is expected to be light, with most areas seeing one
tenth inch or less of rainfall. It will be considerably cooler on
Tuesday with highs well below normal for this time of year. NAM
guidance looks too cool with highs in the upper 50s, so went with a
GFS/NAM blend, which looks more reasonable with highs topping out in
the lower 60s. Lingering showers will be possible Tuesday evening
over southeast sections, otherwise dry conditions are expected
overnight with clearing skies, as drier air filters in behind the
departing upper trough. Temperatures will be very chilly Wednesday
night with overnight lows in the lower and middle 40s.
Dry and cool weather will continue on Wednesday with sunny skies,
light winds and highs in the lower 70s. Another cool night is in
store Wednesday night with low temperatures again in the 40s. Will
maintain a dry forecast Thursday into next weekend with a warming
trend through the period. Northwest flow aloft is expected through
Saturday, with a short wave ridge overspreading the Plains on
Sunday. High temperatures will warm from the mid 80s late week, to
the upper 80s and lower 90s by the end of the weekend. Expect
overnight lows in the 50s, warming into the 60s through the
period.
&&
.FIRE WEATHER...
Elevated fire weather conditions will be possible across much of
West Central Texas Wednesday through Friday, as minimum relative
humidity values drop to 15 to 20 percent, but 20 foot winds
generally remain below 15 mph.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 80 50 63 45 72 / 40 20 20 10 0
San Angelo 86 52 62 43 73 / 30 20 20 10 0
Junction 85 57 64 46 73 / 50 70 40 20 0
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
21/24
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
437 AM CDT MON MAY 12 2014
.DISCUSSION...
THE POTENT UPPER LEVEL LOW OVER THE FOUR CORNERS THAT WAS
RESPONSIBLE FOR SNOW IN DENVER YESTERDAY WILL EJECT NORTHEAST OUT
INTO THE PLAINS TODAY...BUT ADDITIONAL UPPER ENERGY WILL DROP INTO
THE BASE OF A DEEPENING LONGWAVE TROUGH TODAY. THIS UPPER TROUGH
WILL ENGULF THE CENTRAL US BY TOMORROW...A PATTERN THAT IS VERY
UNUSUAL FOR MID MAY. THIS SYSTEM HAS TAPPED INTO A CANADIAN
AIRMASS AND HAS SENT AN UNSEASONABLY STRONG COLD FRONT BARRELING
SOUTH. AT 4AM...THIS FRONT WAS LOCATED JUST SOUTH OF LUBBOCK TO
NEAR VERNON TO EL RENO OKLAHOMA AND WAS MOVING SOUTHEAST AT 15 TO
20MPH. THE FRONT IS AHEAD OF MOST MODEL PROJECTIONS...WHICH IS
NOT SURPRISING GIVEN THE COLD AIR BEHIND IT. THE RAP HAS A GOOD
HANDLE ON THE FRONT/S SPEED AND IT WILL BE USED FOR TIMING.
THE FRONT WILL ARRIVE INTO THE NORTHWEST CWA BY MID-MORNING AND
CONTINUE TO TRACK SOUTHEAST...BUT SLOW DOWN A BIT DUE TO DAYTIME
HEATING. THE FRONT SHOULD REACH A SHERMAN TO DFW TO COMANCHE LINE
BY MID-AFTERNOON. THE AIRMASS AHEAD OF THE FRONT WILL BE WARM AND
MOIST...WITH SEVERAL DAYS OF SOUTHERLY FLOW NOW BRINGING
PRECIPITABLE WATER VALUES UP TO 1.75 TO 2 INCHES. SURFACE BASED
CAPE WILL PEAK AROUND 2000-2500 J/KG THIS AFTERNOON AS TEMPS WARM
INTO THE MID 80S. DAYTIME HEATING AND FORCING FOR ASCENT FROM THE
UPPER LEVEL TROUGH WILL LIFT/ERODE THE WEAK CAPPING
INVERSION...AND THUS CONVECTION WILL INCREASE IN COVERAGE ALONG
THE FRONT BY LATE MORNING. BULK LAYER SHEAR IS FAIRLY WEAK...ON
THE ORDER OF 25KT...SO MULTICELLULAR CONVECTIVE MODES ARE
EXPECTED. GIVEN THE HIGH INSTABILITY AND WEAK SHEAR...SOME SEVERE
WIND/HAIL REPORTS ARE POSSIBLE TODAY WITH THE STRONGEST STORMS.
CONVECTION ALONG THE FRONT WILL LIKELY CONGEAL INTO A SOLID LINE
OF THUNDERSTORMS BY MID-AFTERNOON...WITH THE LINE CONTINUING TO
GROW UPSCALE INTO A FORMIDABLE LINEAR MCS BY THE EVENING HOURS.
MCS PROPAGATION VECTORS AND DIFFLUENT THICKNESS FIELDS ALOFT
SUGGEST THAT THE MOVEMENT OF THIS SYSTEM WILL REMAIN FAIRLY
SLOW...LIKELY LESS THAN 10-15MPH. THIS FORWARD SPEED SHOULD IN
THEORY LIMIT THE DAMAGING WIND THREAT THIS EVENING OVER THE
SOUTHEAST HALF OF THE CWA...BUT WILL RESULT IN ENHANCED RAINFALL
TOTALS. THE MCS WILL LIKELY HAVE SLOWER WEST TO EAST MOVEMENT THAN
NORTH TO SOUTH...AND THUS THE ORIENTATION OF THE LINE SUGGESTS
THAT EASTERN ZONES WILL HAVE A GREATER RISK FOR PROLONGED HEAVY
RAINFALL. EXPECT THE LINE TO PUSH THROUGH THE SOUTHWEST ZONES
FAIRLY QUICKLY...LIKELY REACHING A LAMPASAS TO WACO LINE BY 6 PM.
A TIGHT RAINFALL GRADIENT IS FORECAST OVER THE CWA WITH LESS THAN
A HALF INCH EXPECTED OVER THE NW ZONES...TO 1-2 INCHES IN A BAND
FROM THE SHERMAN AREA TO THE METROPLEX TO COMANCHE...AND 2-3
INCHES SOUTH AND EAST OF A PARIS TO GREENVILLE TO HILLSBORO LINE.
THIS LATTER REGION WAS THE SAME AREA THAT RECEIVED A SWATH OF 2-4
INCHES OF RAIN THURSDAY AND SOILS ARE ALREADY SATURATED. THUS A
FLASH FLOOD WATCH WAS ISSUED FOR LOCATIONS ALONG AND SOUTHEAST OF
A BONHAM TO DALLAS TO TEMPLE LINE. WHILE WE DONT EXPECT MOST OF
DALLAS AND COLLIN COUNTIES TO RECEIVE MORE THAN 2 INCHES...GIVEN
THE URBAN DEVELOPMENT THERE AND THE FACT THAT THE SOUTHEAST PARTS
OF THESE COUNTIES DID SEE OVER 4 INCHES...FELT IT WAS BEST TO
INCLUDE THEM. FARTHER SOUTH...FROM WACO TO ATHENS...LESS RAIN FELL
IN THIS AREA LAST THURSDAY...BUT QUICK TOTALS OF 2-3 INCHES ARE
POSSIBLE THIS EVENING. FOR WACO/TEMPLE/KILLEEN ONLY AROUND 2
INCHES ARE FORECAST...BUT AGAIN URBAN INFRASTRUCTURE MAY
EXACERBATE ANY FLOODING...SO THEY WERE INCLUDED IN THE WATCH TOO.
BECAUSE THE UPPER LEVEL TROUGH WILL BE SLOW TO MOVE
EAST...CONTINUED SOUTHERLY FLOW ALOFT BEHIND THE FRONT/LINE OF
STORMS WILL OCCUR THIS EVENING. THUS THE LINE OF STORMS WILL
LIKELY BE SUCCEEDED BY A FEW HOURS OF STEADY LIGHT TO MODERATE
STRATIFORM RAINS...ESPECIALLY ACROSS THE WATCH AREA. THIS ACTIVITY
SHOULD END FROM NORTHWEST TO SOUTHEAST LATE TONIGHT...BUT MAY
LINGER OVER THE SOUTHEAST ZONES INTO TUESDAY MORNING. TUESDAY
SHOULD BE DRY FOR THE REMAINDER OF THE AREA WITH MOSTLY CLOUDY AND
COOL CONDITIONS AS COOLER AIR POURS INTO THE REGION BEHIND THE
FRONT. FORECAST HIGH TEMPS MAY BE TOO WARM...BUT IT WOULD ONLY
TAKE AN HOUR OR TWO OF AFTERNOON MAY SUNSHINE TO WARM US INTO THE
MID 60S...SO STAYED CONSERVATIVE THERE.
THE STRONGEST UPPER LEVEL FORCING WILL CROSS THE REGION TUESDAY
EVENING BUT THE AIRMASS WILL BE PRETTY WORKED OVER. HOWEVER THIS
FORCING SHOULD RESULT IN SCATTERED ELEVATED SHOWERS AND A FEW
STORMS OVER THE REGION AND SHOULD SQUEEZE OUT ANOTHER TENTH TO
QUARTER INCH OF RAINFALL. HAVE BUMPED POPS UP TUESDAY NIGHT AS
MODEL GUIDANCE HAS COME INTO BETTER AGREEMENT ON THIS ROUND.
OTHERWISE THE REMAINDER OF THE FORECAST LOOKS QUIET AND VERY NICE
FOR MID TO LATE MAY. DRY NORTHWESTERLY FLOW ALOFT WILL PREVAIL
THROUGH THE WEEKEND LEADING TO CLEAR SKIES AND LIGHT WINDS. GOOD
RADIATIONAL COOLING WEDNESDAY NIGHT WILL SEND LOW TEMPS DOWN INTO
THE 40S AREA WIDE...AND WACO MAY BREAK ITS RECORD LOW OF 46. HIGHS
IN THE UPPER 60S ARE EXPECTED THURSDAY...BUT TEMPS SHOULD WARM
INTO THE 70S FRIDAY AND THE 80S BY THE WEEKEND. DRY WEATHER WILL
CONTINUE INTO NEXT WEEK WITH TEMPS WARMING TO ABOVE NORMAL.
TR.92
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 83 54 66 51 68 / 90 80 20 40 10
WACO, TX 87 57 65 51 69 / 70 100 40 60 10
PARIS, TX 84 56 63 51 64 / 70 90 20 50 20
DENTON, TX 80 52 65 49 68 / 80 70 20 40 10
MCKINNEY, TX 83 53 64 50 68 / 90 80 20 40 10
DALLAS, TX 84 55 65 52 68 / 90 80 20 50 10
TERRELL, TX 85 57 64 51 67 / 70 90 20 50 20
CORSICANA, TX 86 59 64 52 67 / 60 100 40 60 20
TEMPLE, TX 87 58 64 52 69 / 50 100 50 60 10
MINERAL WELLS, TX 79 50 66 47 71 / 70 60 20 30 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM THIS AFTERNOON THROUGH LATE TONIGHT FOR
TXZ094-095-104>107-119>123-134-135-145>148-158>162-174-175.
&&
$$
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
1248 AM CDT MON MAY 12 2014
.DISCUSSION...NOTE AVIATION DISCUSSION BELOW.
&&
.AVIATION...MVFR/IFR CEILINGS EXPECTED OVERNIGHT. MVFR/VFR
CEILINGS EXPECTED DRG THE DAYTIME MONDAY ALONG WITH THE
POSSIBILITY OF SHOWERS AND THUNDERSTORMS...WITH MVFR VISIBILITIES...
DRG THE AFTN MAINLY WEST OF U.S. ROUTE 77. THE CHANCE FOR SHOWERS
AND THUNDERSTORMS WL INCREASE MONDAY EVENING/NIGHT. ANTICIPATE
THAT VERTICAL WIND SHEAR WL REMAIN BELOW NON-CONVECTIVE LLWS
CRITERION OVERNIGHT. MODERATE/BREEZY ONSHORE FLOW EXPECTED DRG THE
LATE MORNING/AFTN.
&&
.PREV DISCUSSION... /ISSUED 917 PM CDT SUN MAY 11 2014/
DISCUSSION...MINOR TEMPERATURE/DEW POINT ADJUSTMENTS TO FALL IN
LINE WITH CURRENT/FORECAST TEMPERATURES. SEE NO REASON AT THIS
TIME TO MAKE OTHER CHANGES INLAND AREAS.
MARINE...INCLUDED PATCHY FOG FOR THE MARINE ZONES AND SOME
LOCATIONS REPORTING 2-5SM. WILL PUT A BRIEF MENTION OF THIS IN
MWW. AM KEEPING SCA GOING AS THIS IS WHAT THE RUC IS SHOWING AND
OTHER MODELS TOO.
PREV DISCUSSION... /ISSUED 644 PM CDT SUN MAY 11 2014/
DISCUSSION...UPDATE FOR 00Z AVIATION DISCUSSION.
AVIATION...DETERIORATING FLIGHT RULES OVERNIGHT. MVFR EARLY IN
THE TAF PERIOD AT KCRP/KVCT/KALI WITH CONDITIONS QUICKLY LOWERING
TO IFR BY MID EVENING...AND REMAINING AT IFR OVERNIGHT. KLRD SHOULD
REMAIN VFR THRU MUCH OF THE NIGHT WITH CIGS LOWERING TO IFR BY
LATE IN THE NIGHT. CIGS AT ALL TERMINALS WILL SLOWLY RISE MON
MRNG WITH MVFR TO VFR RETURNING TO KLRD BY LATE MRNG...KALI BY
MIDDAY...WITH KCRP/KVCT LIKELY REMAINING AT MVFR THRU MON AFTN.
ISO CONVECTION MAY APPROACH KLRD BY LATE MON AFTN BUT BETTER
CHANCES WILL OCCUR JUST BEYOND VALID TAF TIME FRAME...SO WILL ONLY
INCLUDE VCTS FOR NOW. ELSEWHERE...CURRENTLY XPCT KCRP/KVCT/KALI
TO REMAIN DRY THRU THE TAF PERIOD ASIDE FROM SOME BRIEF -DZ.
MODERATE/GUSTY SE WINDS THIS EVENING WILL REMAIN BETWEEN 08-14 KTS
OVERNIGHT...WITH GUSTY SE WINDS RETURNING FOR MIDDAY/AFTN HRS OF
MON.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 88 73 76 59 75 / 30 50 70 60 20
VICTORIA 88 72 75 57 75 / 30 60 70 60 20
LAREDO 96 74 80 61 79 / 40 70 60 40 10
ALICE 91 72 77 58 76 / 30 60 70 60 20
ROCKPORT 84 73 75 62 74 / 20 40 70 60 20
COTULLA 92 71 77 57 78 / 40 70 50 40 10
KINGSVILLE 90 73 77 59 76 / 30 50 70 60 20
NAVY CORPUS 84 73 75 61 74 / 20 40 60 60 20
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 7 AM CDT THIS MORNING FOR THE
FOLLOWING ZONES: COASTAL WATERS FROM BAFFIN BAY TO PORT
ARANSAS OUT 20 NM...COASTAL WATERS FROM PORT ARANSAS TO
MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM BAFFIN BAY
TO PORT ARANSAS FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS
TO MATAGORDA SHIP CHANNEL FROM 20 TO 60 NM.
&&
$$
WC/87...AVIATION
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1157 PM CDT SUN MAY 11 2014
.AVIATION...
/06Z TAFS/
Thunderstorms and widespread MVFR ceilings do not look likely for
the remainder of tonight. The latest satellite imagery indicates
stratus is returning. However, the latest METAR for Junction
indicates a broken ceiling at only twenty nine hundred feet above
ground level. So, stratus may not be as low as the previous forecast
package indicated. Thunderstorms, associated with the cold front,
still look possible for tomorrow.
&&
.PREV DISCUSSION... /ISSUED 813 PM CDT SUN MAY 11 2014/
DISCUSSION...
Despite the instability in place and persistent cumulus field,
thunderstorms have not developed along the dryline so far this
evening in the eastern TX Panhandle or Low Rolling Plains east of
Lubbock. Surface convergence is weak and upper forcing is still
lagging to the west over the southern Rockies. The dryline farther
south is retreating to the west. The GFS looks to be the the most
optimistic with convective development early tonight before 06Z in
our northern and western counties. Recent HRRR and Texas Tech WRF,
however, hold off with shower/thunderstorm development until 2-3
hours after Midnight across our far western counties. The Texas Tech
WRF indicates possibility of isolated thunderstorm development near
our northwestern border counties (Fisher and Nolan Counties) late
this evening/early tonight. Given the satellite and model trends,
have scaled back the PoPs early tonight with slight chance confined
to the the area west of Haskell to Sweetwater before 2 AM. With the
instability and deep layer shear, severe potential remains for any
storms which can develop on the dryline. As large scale ascent
begins to impinge on the area late tonight, could have
shower/thunderstorm development across our west and northwest
counties, spreading east overnight and early Monday morning.
Carrying 30-40 PoPs across the area north and west of a San Angelo
to Baird line late tonight. Have also adjusted sky condition to
clear skies this evening based on satellite indications. Updated
forecast will be out shortly.
19
PREV DISCUSSION... /ISSUED 650 PM CDT SUN MAY 11 2014/
AVIATION...
/00Z TAFS/
Thunderstorms and MVFR ceilings are possible across West Central
Texas during the next 24 hours. Forecast models indicate stratus
will return to our southern terminals a couple hours after midnight.
The best timing for thunderstorms will also begin after midnight and
continue through tomorrow, as another cold front moves into West
Central Texas.
PREV DISCUSSION... /ISSUED 335 PM CDT SUN MAY 11 2014/
SHORT TERM...
(Tonight and Monday)
A fairly complex weather forecast can be expected through the
next 24 hours. Currently a dryline is located west of the area,
with all of West Central Texas experiencing dewpoints in the mid
50s to lower 60s. The dryline is forecast to continue to sharpen
to our west this afternoon, with an increasingly unstable
atmosphere ahead of it. The main caveat is the lack of upper level
forcing, and whether we are able to break the cap late this
afternoon or early this evening. My current thinking is that we
will see at least isolated convection along the dryline, mainly
beginning this evening as better upper level forcing arrives, then
moving east late this evening and early Monday morning. A
strengthening low level jet should help to sustain any convection
that does develop, with most convection waning by sunrise. Any
storms that do develop this evening, have the potential to become
strong to severe, with large hail and damaging winds being the
main hazards.
The main feature of interest on Monday is a cold front that will
slowly move through the area. The front is forecast to move into the
northern Big Country late Monday morning, then into the Concho
Valley during the afternoon, with a dryline extending south across
the northern Edwards Plateau. Showers and thunderstorms are forecast
to develop along and ahead of the front late in the morning, then
increase in coverage by mid to late afternoon. At this time, the
best coverage and heaviest rainfall looks to generally east of a
Cross Plains, to Eden, to Junction line, where precipitable water
values of 1 to 1.5 inches are forecast. Again, a few storms could
become strong to severe, with large hail and damaging winds being
the main hazards.
Daniels
LONG TERM...
(Monday night through Sunday)
..A heavy rainfall threat will exist through Monday night...
A very slow moving cold front will ease across the southeast
quadrant of the CWA Monday night, providing a low-level focus for
convective development. Ascent will be aided by strong upper-level
divergence in the right entrance region to the polar jet. Forecast
precipitable water values Monday night are progged to be in the
1.4 to 1.7" range, about 2 standard deviations above the mean for
this time of year. The 0-6km shear vector will be nearly parallel
with the aforementioned frontal boundary, suggesting that storms
may train along the baroclinic zone, enhancing the potential for
locally heavy rainfall. Widespread showers and thunderstorms will
result in general rainfall amounts of 1-3", with locally higher
amounts, generally east of a Cross Plains to Junction line.
Farther west, QPF amounts are quite a bit lighter, but a good 1/4"
of rain or more is expected from Sweetwater south to Sonora. There
is a threat for severe thunderstorms as well, mainly during the
afternoon and evening hours before convection congeals into a
multicell mess. The primary threats will be large hail and
damaging winds.
The cold front will be south of the area by Tuesday morning with
north winds of 15-20 mph expected throughout the day. Upper-level
forcing will remain present, but without the frontal forcing, it
looks like precipitation will be weaker, with thunder becoming
less likely. PoPs in the 20-40% range were carried southeast of
an Ozona to Cross Plains line, but rainfall amounts should remain
less than 1/4" on average. Temperatures will be noticeably cooler
on Tuesday with highs generally in the mid 60s. The NAM is still
keeping highs in the 50s across the area but this seems a bit
extreme.
Precip is expected to come to an end by Tuesday evening with drier
air advecting into the area overnight. As winds decrease, the
dry air should allow fairly strong decoupling of the boundary
layer. With skies clearing, temps are expected to fall into the
low/mid 40s. North to northeast winds on Wednesday will keep temps
on the cool side, with highs only the 70s. We`re in store for
another cool morning on Thursday with 40s once again expected
across most of the area.
Generally benign weather conditions are expected through the
remainder of the forecast period. Dry northwesterly flow
downstream of the western CONUS ridge will promote mostly clear
skies. Southerly winds will resume across the area by Thursday as
lee cyclogenesis ramps up. With the return flow, temps will
rebound quickly into the 80s with highs expected to reach 90
degrees over the weekend. This is a potential cold front we`ll
have to watch out for Friday into Saturday as a potent shortwave
trough moves across the central Plains. However, the current model
guidance stalls this boundary near the Red River, maintaining
southerly winds across the region.
Johnson
FIRE WEATHER...
Elevated fire weather conditions are forecast across the western
Concho Valley and Crockett County Monday afternoon. Minimum relative
humidity values will drop below 20 percent, but 20 foot winds will
remain light. Elevated fire weather conditions will once again be
possible across much of West Central Texas Wednesday through Friday,
as minimum relative humidity values drop to 15 to 20 percent, but 20
foot winds generally remain below 15 mph.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 69 80 50 66 46 / 30 40 20 10 5
San Angelo 69 84 52 65 44 / 30 30 30 10 5
Junction 72 82 57 68 47 / 10 50 70 40 10
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
501 AM EDT MON MAY 12 2014
.SYNOPSIS...
HIGH PRESSURE OFF THE SOUTHEAST COAST IS GOING TO KEEP OUR REGION
IN A INCREASINGLY HUMID AIRMASS. A SLOW MOVING FRONT ENTERS THE
REGION BY THURSDAY AND SLIDES EAST FRIDAY. A COOLER AIRMASS
FOLLOWS THIS FRONT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 400 AM EDT MONDAY...
DESPITE INCREASING 5H HEIGHTS TODAY...WILL STILL SEE A COUPLE OF
EMBEDDED SHORTWAVES RIDE THE NRN CENTER OF THE HIGH ACROSS OUR AREA.
EARLY THIS MORNING...THERE IS A WEAK SHORTWAVE MOVING ACROSS WV
WITH TAIL END OF SHOWERS PUSHING EAST BETWEEN BKW-CRW BUT WEAKENING.
THE LATEST HRRR SHOWS THIS AREA MAYBE SCRAPING NRN GREENBRIER AND
BATH. OVERALL...SHOULD BE A DRY MORNING WITH PATCH FOG IN THE
VALLEYS/RIVER AREAS.
TODAY...THE SFC HIGH OFF THE COAST WILL CONTINUE TO KEEP MOISTURE
STREAMING NWD INTO THE CENTRAL APPALACHIANS. HEATING WILL LEAD TO
INSTABILITY AND OVERALL WEAK FORCING FAVORS SCATTERED SHOWERS AND
STORMS POPPING AROUND MIDDAY IN THE MTNS WITH STEERING FLOW TAKING
THEM EAST TO THE BLUE RIDGE AND FOOTHILLS DURING THE AFTERNOON.
FURTHER SOUTH ACROSS NC/SOUTHSIDE VA...AIRMASS MAY BE JUST CAPPED
ENOUGH TO LIMIT CONVECTION...ALTHOUGH A FEW SHOULD SKIRT BY THIS
EVENING WHEN CAP WEAKENS. OVERALL KEPT POPS UNDER HIGH CHANCE...BUT
WILL BE A CASE WHERE 1/3-1/2 OF A COUNTY GETS RAINED ON...WHILE THE
OTHER HALF MISSES OUT.
FOR HIGHS WILL SEE MOSTLY SUNNY SKIES EARLY WITH CU/TCU DEVELOPING
WITH SOME AC/CI OVERTOP. THIS WILL LIMIT HEATING MAINLY OVER THE
MOUNTAINS BUT STILL LOOKING AT TEMPS RUNNING AROUND 10 DEGREES ABOVE
NORMAL. HIGHS RANGING FROM THE UPPER 70S/LOWER 80S WEST TO NEAR 90
SOUTHEAST.
TONIGHT...CONVECTION WEAKENS WITH LOSS OF HEATING. THE 00Z WRF/NAM
HOLD ONTO ACTIVITY INTO LATE EVENING WHILE THE OTHER MODELS SHOWING
LITTLE TO NONE AFTER 00Z/8 PM. WILL LEAN TOWARD THE HIGHER RES
MODELS SINCE ANY OUTFLOW COULD KEEP A SHOWER/STORM GOING PAST 8 PM.
BY MIDNIGHT WILL BE CLEAR TO PARTLY CLOUDY AND HUMID WITH LOWS IN
THE UPPER 50S TO LOWER 60S. FOG COULD BECOME AN ISSUE SINCE RAIN
SHOWERS ARE EXPECTED THIS AFTERNOON...ALTHOUGH COVERAGE WILL BE
PATCHY.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/...
AS OF 415 AM EDT MONDAY...
UPPER LEVEL RIDGING WILL BE FIRMLY IN PLACE TUESDAY MORNING ACROSS
THE EASTERN SEABOARD...WHICH WILL RESULT IN VERY SUMMER LIKE
TEMPERATURES. EXPECT AFTERNOON HIGHS TO RANGE FROM THE LOW/MID 80S
ACROSS THE MOUNTAINS... TO THE LOW 90S ACROSS THE SOUTHSIDE. STRONG
HEATING AND CONTINUED MOISTURE INFLOW SHOULD HELP KICK OFF A FEW
SHOWERS AND THUNDERSTORMS DURING LATE AFTERNOON AND EARLY EVENING...
HOWEVER THE RIDGING WILL KEEP THIS ACTIVITY SPOTTY AT BEST AND
DISORGANIZED. WILL BE KEEPING AN EYE ON A COLD FRONT BACK DOORING
ITS WAY SOUTHWARD FROM NEW ENGLAND DURING THE AFTERNOON AND
EVENING...BUT DO NOT THINK IT WILL APPROACH CLOSE ENOUGH TO ENHANCE
CONVECTION OVER OUR AREA. AT ANY RATE...ANY CONVECTION SHOULD
GRADUALLY FIZZLE TOWARD SUNSET...AND PATCHY FOG WILL BE POSSIBLE
TUESDAY NIGHT...ESPECIALLY IN AREAS WHICH DO RECEIVE A DOWNPOUR.
BETTER CHANCES FOR SHOWER AND THUNDERSTORMS WILL OCCUR ON WEDNESDAY
AS UPPER LEVEL RIDGING BEGINS TO SHIFT EAST...WHILE THE BACK DOOR
FRONT STALLS ACROSS NORTHERN VIRGINIA JUST OUTSIDE OUR FORECAST
REGION. ANOTHER DAY OF STRONG HEATING AS HIGHS REACH INTO THE 80S
MOST LOCATIONS...COMBINED WITH LOW LEVEL CONVERGENCE ASSOCIATED WITH
THE NEARBY FRONT...WILL LEAD TO HIGHER RAIN CHANCES ACROSS THE
MOUNTAINS AND THE PIEDMONT NORTH OF HIGHWAY 460. THE INCREASED
INSTABILITY WILL ALLOW FOR GREATER POTENTIAL FOR ORGANIZED
THUNDERSTORM ACTIVITY...AND A FEW STORMS WILL LIKELY BECOME STRONG
DURING LATE AFTERNOON AND EARLY EVENING...CAPABLE OF PRODUCING
LOCALLY STRONG WINDS AND HAIL. WILL SEE THE BOUNDARY ACROSS NORTHERN
VIRGINIA LIFT TOWARD NEW ENGLAND DURING LATE EVENING AS A WARM
FRONT...WHILE A STRONG COLD FRONT APPROACHES OUR REGION FROM THE
WEST.
THE COLD FRONT WILL ENTER OUR WESTERN MOST COUNTIES DURING MID
AFTERNOON...RESULTING IN WAVES OF LOCALLY HEAVY RAIN AS UPPER LEVEL
DISTURBANCES PASS OVERHEAD ALONG THE BOUNDARY. MODELS ARE PICKING UP
ON AT LEAST ONE STRONG WAVE POTENTIALLY BRINGING HEAVY RAIN TO THE
FOOTHILLS AND THE PIEDMONT DURING THE EVENING...AND POSSIBLY A
SECOND WAVE IF THE COLD FRONT SLOWS/STALLS BEFORE EXITING OUR REGION
DURING EARLY FRIDAY MORNING. STILL NOT ENOUGH CONFIDENCE IN THE
MODELS TO TACK DOWN RAINFALL AMOUNTS...BUT IT IS LOOKING SAFE TO SAY
THAT THE MUCH OF THE REGION WILL RECEIVE BETWEEN ONE AND TWO INCHES
FOR THE THURSDAY AND EARLY FRIDAY TIME PERIOD...WITH SOME AREAS
PICKING IN EXCESS OF 3 INCHES...ESPECIALLY ALONG THE BLUE RIDGE.
MODELS ARE IN DECENT AGREEMENT THAT THE FRONT AND ASSOCIATED HEAVY
RAIN WILL BE EAST OF OUR AREA DURING EARLY FRIDAY AFTERNOON...
LEAVING ONLY RESIDUAL SHOWER ACTIVITY...AS WELL AS A SHARP DROP IN
TEMPERATURES AS A DEEP UPPER TROUGH APPROACHES FROM THE WEST.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 400 PM EDT SUNDAY...
AN AMPLIFIED MID-UPPER LEVEL MEAN TROUGH SETTLES OVER THE ERN HALF
OF THE CONUS FOR THE LATTER HALF OF THE WEEK AND INTO NEXT
WEEKEND.
AS WE TRANSITION INTO THE WEEKEND...FLOW BECOMES BLOCKY WITH A
DEEP QUASI-STATIONARY...ALMOST WINTERLIKE UPPER LOW PARKED OVER
THE GREAT LAKES REGION. 850MB TEMPS WILL DROP INTO THE 3C TO 6C
RANGE FOR MOST OF THE CWA AND LINGER IN THIS RANGE FOR SEVERAL
DAYS. SEVERAL SPOKES OF PVA ARE EXPECTED TO ROTATE AROUND THIS
UPPER LOW WHICH SUGGESTS POTENTIAL FOR CLOUDS AND SHOWERS...
ESPECIALLY ACROSS THE MOUNTAINS. TEMPERATURES WILL TREND TO THE
COOLER SIDE OF NORMAL. FORTUNATELY...CLOUDS...SHOWERS...AND A BIT
OF A NW BREEZE SHOULD MITIGATE FROST POTENTIAL. NONETHELESS...IT
WILL BE QUITE CHILLY WITH HIGHS IN THE 60S AND LOWS IN THE 40S
ACROSS MUCH OF THE REGION...A BIG CONTRAST FROM THE WARMTH THE
FIRST HALF OF THIS WEEK.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
AS OF 120 AM EDT MONDAY...
CIRRUS FROM UPSTREAM CONVECTION ALONG WITH SCATTERED AC WILL BE
PUSHING ACROSS SE WV THIS MORNING AND PORTIONS OF THE ROA/BCB
CORRIDOR. OVERALL THE CONDITIONS WILL BE VFR...WITH MOISTURE
SITUATED IN THE SFC LAYER TO PROVIDE FOG POTENTIAL AT ALL SITES
WITH BEST THREAT AT BCB/LWB...TO GO AS LOW AS LIFR AROUND 09-12Z.
THE HIGH CLOUDINESS IF IT HANGS AROUND WILL PRECLUDE THIS BUT
CONFIDENCE IS ENOUGH THINNING AND CALM WINDS TO ADD IT TO THE
TAFS.
TODAY...ANY FOG BURNS OFF AROUND 12-13Z. SW FLOW ALOFT PLUS
HEATING THROUGH THE DAY WILL BE ENOUGH TO PRODUCE SCT/BKN
CU...WITH HIGHER COVERAGE OVER THE MOUNTAINS. PER LATEST
NAM/WRF...SHOULD SEE ISOLATED COVERAGE OF SHOWERS/STORMS IN THE
PIEDMONT THIS AFTERNOON WITH SCATTERED COVERAGE ALONG AND WEST OF
THE BLUE RIDGE. THINK HIGH PRESSURE ALOFT MAY CAP THINGS ACROSS
SOUTHSIDE VA/DAN AND POINTS SOUTH. FOR NOW HAVE VCTS AT ALL BUT
DAN DURING THE AFTERNOON...BEFORE TAKING IT OUT AROUND 0Z TUE.
UPPER RIDGE ALOFT STRENGTHENS OVER THE REGION TUESDAY...PROVIDING
MAINLY VFR CONDITIONS. THE UPPER RIDGE WILL SHIFT EAST OF THE
REGION WEDNESDAY AS A STRONG COLD FRONT AND DEEPENING UPPER LOW
MOVE INTO THE AREA FROM THE CENTRAL UNITED STATES. THIS SYSTEM HAS
THE POTENTIAL TO BRING AN EXTENDED PERIOD OF SHRA/TSRA AND
ASSOCIATED MVFR OR LOWER CIGS AND VSBYS TO THE REGION...LINGERING
PERHAPS INTO EARLY FRIDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...PC/WP
NEAR TERM...WP
SHORT TERM...NF
LONG TERM...PM
AVIATION...RCS/WP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1133 PM CDT SUN MAY 11 2014
.UPDATE...
ISSUED AT 938 PM CDT SUN MAY 11 2014
WITH RAINFALL RATES OF 1 TO 2 INCHES PER HOUR POSSIBLE
OVERNIGHT AND GRB ADDING A FLASH FLOOD WATCH FOR SOME OF THEIR
COUNTIES IN NORTH CENTRAL WISCONSIN...HAVE DECIDED TO CHANGE OVER
THE FLOOD WATCH TO A FLASH FLOOD WATCH AND EXTEND IT THROUGH 6Z
TUESDAY WHEN THE COLD FRONT SHOULD BE CLEAR OF THE REGION. TIMING
OF THE COMPLEX MAKING IT INTO NORTHEAST IOWA STILL LOOKS GOOD FOR
AROUND MIDNIGHT NEAR THE I-35 CORRIDOR...IT IS JUST A MATTER OF
HOW INTENSE IT WILL BE AS IT GETS IN.
UPDATE ISSUED AT 855 PM CDT SUN MAY 11 2014
THE MAIN FOCUS WITH THE FORECAST IS WITH THE SEVERE WEATHER
POTENTIAL OVERNIGHT. CURRENT SURFACE ANALYSIS SHOWS A LOW PRESSURE
SYSTEM CENTERED NEAR OMAHA WHERE A BOWING COMPLEX HAS EMERGED FROM
A LONG TRACK HP SUPERCELL THAT TRACKED ACROSS SOUTHEAST NEBRASKA
THIS AFTERNOON. THE MAIN SURFACE WARM FRONT APPEARS TO EXTEND EAST
FROM OMAHA ACROSS SOUTHERN IOWA WITH AN INVERTED TROUGH EXTENDING
NORTH FROM THE LOW INTO SOUTHWEST MINNESOTA. ANOTHER DEW POINT
GRADIENT EXISTS ALONG THE MINNESOTA/IOWA BORDER WHERE DEW POINTS
GO FROM THE MID 50S IN SOUTHEAST MINNESOTA TO THE LOW 60S IN
NORTHEAST IOWA. 12.00Z RAP ANALYSIS SUGGESTS THAT THERE STILL IS
QUITE A BIT OF INSTABILITY AHEAD OF THIS COMPLEX RUNNING EAST
ACROSS IOWA WITH 0-3KM MUCAPE AROUND 2000 J/KG FROM DES MOINES
EAST AND AROUND 1000 J/KG RUNNING ALONG THE MINNESOTA/IOWA BORDER.
SURFACE BASED CAPE IS STARTING TO DECREASE...BUT IS STILL FAIRLY
DECENT OUT AHEAD OF THE BOW AT 2000 J/KG.
SHORT TERM GUIDANCE HAS BEEN VERY CONSISTENT THIS AFTERNOON/EARLY
EVENING WITH SHOWING AN INITIAL BAND OF MAINLY WEAK CONVECTION
DEVELOPING ALONG THE LEADING EDGE OF THE 925-850MB MOISTURE
TRANSPORT AND LIFTING NORTH THROUGH THE EVENING. THE MAIN QUESTION
IS WITH WHERE THE COMPLEX IN WESTERN IOWA WILL TRACK. WITH THE
925MB JET AND MOISTURE TRANSPORT INCREASING AND LIFTING NORTH
OVERNIGHT...THE SUPPORT IS THERE FOR ANY CONVECTION TO CONTINUE
TO TRACK EAST-NORTHEAST. FORWARD PROPAGATING CORFIDI VECTORS AND
0-3KM SHEAR IS ALL POINTING FROM THE SOUTHWEST TO THE NORTHEAST
AND THAT HAS BEEN BACKED BY THE INITIAL TRENDS WITH THE BOW.
CURRENT EXTRAPOLATION AND MESO-MODELS WOULD SAY THAT THE LEADING
EDGE OF THIS COMPLEX WOULD BE INTO THE CHARLES CITY IOWA AREA
AROUND OR SHORTLY AFTER MIDNIGHT...TO THE MISSISSIPPI RIVER IN NE
IA/SW WI AROUND 3AM...AND ON INTO SOUTH CENTRAL WISCONSIN BY 5AM.
THIS LINE OF STORMS HAS ALREADY PRODUCED 80MPH WIND GUSTS AT
OMAHA...BUT DO NOT EXPECT IT TO BE AT THAT STRENGTH...BUT STILL
POSSIBLY SEVERE...AS IT GETS INTO THE REGION. AM CONSIDERING CHANGING
THE FLOOD WATCH TO A FLASH FLOOD WATCH SINCE THERE APPEARS TO BE A
CHANCE THAT THIS COMPLEX SLOWS DOWN AND PRODUCES SOME HEAVY
RAINFALL OVER A SHORT PERIOD OVERNIGHT THAT IS TIED MORE TO
CONVECTION THAN A LONG LIVED MODERATE RAIN.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 325 PM CDT SUN MAY 11 2014
FOCUS OF THE FORECAST IS ON RAIN THROUGH TUESDAY.
REGIONAL RADARS SHOW A CONVECTIVE COMPLEX HAS SURVIVED FROM THE
OVERNIGHT HOURS AND CONTINUES TO TRANSLATE ACROSS SOUTHERN IOWA.
THAT HAS EFFECTIVELY PINNED THE WARM FRONT WELL SOUTH OF THE AREA
ALONG THE IOWA/MISSOURI BORDER. THIS HAS ALSO PINNED MOST OF THE
CAPE TO THE SOUTH WITH THE 19Z MU CAPE SHOWING LESS THAN 500 J/KG
ACROSS THE AREA. THE CONCERN BECOMES WHAT HAPPENS THIS EVENING AS
THE COMPLEX CONTINUES TO MOVE EAST AND IF THE WARM FRONT CAN MAKE
A MOVE NORTH. THE 11.17Z HRRR SUGGESTS THAT THE WARM FRONT WILL
START TO PUSH NORTH THIS EVENING BUT MAY STILL BE ONLY ABOUT AS
FAR NORTH AS THE INTERSTATE 80 CORRIDOR BY 03Z. THE WARM FRONT
COULD THEN GET PUSHED NORTHEAST THROUGH THE REST OF THE EVENING
AND NIGHT AS A STRONG SHORT WAVE TROUGH MOVES NORTHEAST ACROSS THE
REGION. THE 11.12Z NAM DOES SUGGEST BETWEEN 1000-1500 J/KG OF ML
CAPE WILL BE IN PLACE ALONG AND NEAR THE WARM FRONT...BUT IF THE
WARM FRONT GETS PUSHED NORTHEAST...THIS CAPE MAY JUST CLIP THE
SOUTHEAST PORTIONS OF THE AREA. HOWEVER...IF THIS SCENARIO DOES
NOT PLAY OUT AND THE CAPE IS FARTHER WEST...THERE WILL STILL BE A
SEVERE THREAT. THE 0-6KM SHEAR THIS EVENING SHOULD INCREASE TO A
RANGE OF 30 TO 50 KNOTS THIS EVENING THEN TO AROUND 60 KNOTS FOR
THE OVERNIGHT HOURS. THE NAM REMAINS CONSISTENT SHOWING 200-300
M2/S2 OF HELICITY OVER THE AREA IN THE 0-3KM LAYER WITH THE BULK
OF THE RESIDING THE 0-1KM LAYER. SO IF THE WARM FRONT CAN GET INTO
THE AREA...THERE WOULD STILL BE A THREAT FOR AN ISOLATED
TORNADO...BUT CONFIDENCE ON THE POSITION OF THE WARM FRONT IS NOT
VERY HIGH.
CONFIDENCE IS HIGH THAT IT WILL RAIN TONIGHT. THE MODELS HAVE BEEN
CONVERGING TOWARD THE SCENARIO THAT AS THE SHORT WAVE TROUGH
COMES OUT OF THE CENTRAL PLAINS AND MOVES NORTHEAST OVER THE
REGION TONIGHT THAT CONVECTION WILL FORM ALONG AN INVERTED TROUGH.
THIS TROUGH CURRENTLY EXTENDS FROM THE SOUTHWEST KANSAS ACROSS
WESTERN IOWA INTO WESTERN WISCONSIN. AS THE SHORT WAVE TROUGH
COMES OUT...MODERATE PV ADVECTION IN THE 500-300 MB LAYER IS
EXPECTED TO OCCUR. IN THE LOW LEVELS...THE WARM AIR ADVECTION WILL
INCREASE AHEAD OF THE WAVE WITH 5 TO 7 UBAR/S OF UP GLIDE ON THE
300K ISENTROPIC SURFACE WITH THE MOISTURE TRANSPORT ON THIS LEVEL
RIGHT INTO THE AREA. EXPECT TO SEE THE LINE OF CONVECTION DEVELOP
IN RESPONSE TO THIS WAVE FROM SOUTHERN MINNESOTA INTO KANSAS AND
THEN MOVE NORTHEAST ACROSS THE AREA THROUGH THE NIGHT. ONCE THE
SHORT WAVE TROUGH MOVES PAST...THE FORCING WILL SHIFT BACK TO THE
WEST AGAIN AHEAD OF THE MAIN LONG WAVE TROUGH AND THE EMBEDDED
SHORT WAVE TROUGH. THIS IS EXPECTED TO MAKE THE MAIN SURFACE LOW
MOVE FROM KANSAS INTO MINNESOTA OR WISCONSIN DURING THE DAY
MONDAY WITH THE COLD FRONT ADVANCING EAST INTO THE AREA. ANOTHER
ROUND OF VERY SIMILAR ISENTROPIC UP GLIDE AND MOISTURE TRANSPORT
IS EXPECTED ON THE 300K SURFACE FOR CONTINUED SHOWERS AND
THUNDERSTORMS AHEAD OF THE FRONT. EVERYTHING THEN STARTS TO
TRANSLATE EAST FOR MONDAY NIGHT WITH THE RAIN CHANCES ENDING FROM
WEST TO EAST THROUGH TUESDAY MORNING.
.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 325 PM CDT SUN MAY 11 2014
WILL CARRY SOME SMALL RAIN CHANCES FOR WEDNESDAY THROUGH FRIDAY
AND THEN SOME ON AND OFF CHANCES OVER THE WEEKEND. ONCE THE SYSTEM
FROM EARLY IN THE WEEK MOVES PAST...THE LONG WAVE TROUGH LOOKS TO
REMAIN OVER THE CENTRAL PART OF THE COUNTRY WITH A NORTHWEST FLOW
FROM NORTHWEST CANADA. THIS SHOULD ALLOW SEVERAL WEAK SHORT WAVE
TROUGHS TO ROTATE THROUGH THE LONG WAVE TROUGH TO SUPPORT THE RAIN
CHANCES. THIS FLOW WILL ALSO HELP TO KEEP TEMPERATURES BELOW
NORMAL WITH HIGHS IN THE 50S TO END THE WEEK AND THEN CREEPING
BACK INTO THE 60S FOR THE WEEKEND. OVERNIGHT LOWS WILL BE IN THE
30S AND MAY HAVE TO DEAL WITH SOME FROST HEADLINES TOWARD THE END
OF THE WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1133 PM CDT SUN MAY 11 2014
A BAND OF SHOWERS AND THUNDERSTORMS ARE CURRENTLY MOVING ACROSS
SOUTHEAST MINNESOTA AND NORTH CENTRAL IOWA AND WILL CONTINUE TO
TRACK TO THE EAST THROUGH THE EARLY MORNING HOURS. VISIBILITY HAS
DROPPED TO 1SM WITH SOME OF THE STRONGER THUNDERSTORMS...SO HAVE
KEPT THAT AS THE TEMPO GROUP THROUGH 10Z AT LSE AND 8Z AT RST. IT
APPEARS THAT THIS RAIN WILL TRACK EAST WITH A DRY PERIOD POSSIBLE
THROUGH THE REST OF THE MORNING. ANOTHER ROUND OF CONVECTION WILL
DEVELOP IN THE AFTERNOON...BUT CONFIDENCE IS NOT VERY HIGH AT THIS
POINT WITH HOW IT WILL PAN OUT AND WHEN IT WILL COME THROUGH THE
TAF SITES.
&&
.HYDROLOGY...
ISSUED AT 325 PM CDT SUN MAY 11 2014
RAINFALL FROM THIS SYSTEM THROUGH MONDAY SHOULD AVERAGE AROUND 2
INCHES FOR MUCH OF THE FORECAST AREA WITH LOCALIZED HIGHER AMOUNTS
EXPECTED. MANY OF THE RIVERS REMAIN HIGH FROM RECENT RUN OFFS AND
THE LATEST FORECASTS FROM THE RFC INDICATED WITHIN BANK RISES FOR
MANY OF THE TRIBUTARIES WITH RENEWED FLOODING POSSIBLE AT SOME
SPOTS ALONG THE MISSISSIPPI. IF THE RAINFALL ENDS UP BEING HIGHER
THAN THE QPF USED BY THE RFC...WHICH IS HIGH PROBABILITY...SOME
THE TRIBUTARIES COULD ALSO GO TO FLOOD. BASED ON THIS...HAVE OPTED
TO ISSUE A FLOOD WATCH FOR THE ENTIRE AREA FOR TONIGHT AND MONDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...FLASH FLOOD WATCH THROUGH LATE MONDAY NIGHT FOR WIZ017-029-
032>034-041>044-053>055-061.
MN...FLASH FLOOD WATCH THROUGH LATE MONDAY NIGHT FOR MNZ079-086>088-
094>096.
IA...FLASH FLOOD WATCH THROUGH LATE MONDAY NIGHT FOR IAZ008>011-018-
019-029-030.
&&
$$
UPDATE...HALBACH
SHORT TERM...04
LONG TERM...04
AVIATION...HALBACH
HYDROLOGY...04
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1014 AM EDT MON MAY 12 2014
.SYNOPSIS...
HIGH PRESSURE REMAINS IN CONTROL THROUGH TODAY THEN A BACK DOOR
COLD FRONT STARTS MOVING THROUGH THE REGION LATE TONIGHT INTO
TUESDAY. MARITIME HIGH PRESSURE WEDNESDAY PROVIDES BELOW AVERAGE
TEMPERATURES FOLLOWED BY A PERIOD OF UNSETTLED WEATHER THURSDAY
THROUGH SATURDAY. BEST CHANCE OF HEAVY RAIN AND POSSIBLE
THUNDERSTORMS EXPECTED FRIDAY NIGHT INTO SATURDAY.
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
10 AM UPDATE...
ANOTHER SPECTACULAR DAY IN PROGRESS WITH DEEP LAYER RIDGE OVER THE
EASTERN GREAT LAKES AND SURFACE HIGH SOUTH OF NEW ENGLAND. THIS
SETUP IS PROVIDING LARGE SCALE SUBSIDENCE OVER THE REGION ALONG
WITH LOW LEVEL WESTERLY FLOW. THUS ABUNDANT SUNSHINE PREVAILS
ALONG WITH COMFORTABLE HUMIDITY WITH DEW PTS IN THE 30S AND 40S.
UPSTREAM SOUNDING AT ALBANY NY SUPPORTS HIGHS AROUND 80F WITH 850
TEMPS OF +11C. HOWEVER WITH BLYR EXTENDING UP TO 700 MB ALONG WITH
WESTERLY BLYR WINDS HIGHS WILL CLIMB INTO THE M80S WITH A LOW
PROBABILITY OF A FEW SPOTS BRIEFLY GETTING INTO THE U80S! THUS
HAVE INCREASED HIGHS A TAD FROM PREVIOUS FORECAST.
THINK DRY WEATHER WILL PREVAIL TODAY DESPITE BACKDOOR FRONT
APPROACHING FROM MAINE. PREFRONTAL AIRMASS IS VERY DRY WITH DEW
PTS IN THE 30S AND 40S. THIS RESULTS IN VERY LITTLE TO ANY
AVAILABLE INSTABILITY. IN ADDITION AS BLYR DEEPENS WINDS BECOME
WEST AND LIMIT SURFACE CONVERGENCE. HENCE DRY WEATHER SHOULD
PREVAIL THRU SUNSET. THIS IS TYPICALLY THE CASE AHEAD OF BACKDOOR
FRONTS. IN ADDITION LATEST HRRR KEEPS SOUTHERN NEW ENGLAND DRY
THRU 23Z FOLLOWED BY A FEW POSSIBLE SHOWERS/TSTMS ZIPPING ACROSS
WESTERN CT THEREAFTER. HOWEVER THIS IS A VERY LOW PROB. OTHERWISE
PREVIOUS FORECAST IN GOOD SHAPE AND NO MAJOR CHANGES PLANNED.
&&
.SHORT TERM /7 PM THIS EVENING THROUGH 6 PM TUESDAY/...
TONIGHT...AN APPROACHING WARM FRONT WILL BE STALLED BY A LOW
PRESSURE MOVING EAST INTO MAINE. ONCE THIS LOW PRESSURE MOVES
QUICKLY EAST...A STRONG HIGH PRESSURE WILL START TO BUILD SOUTH
ACROSS NORTHERN NEW ENGLAND. THIS HIGH PRESSURE WILL PUSH A BACK
DOOR COLD FRONT INTO SOUTHERN NEW ENGLAND LATE TONIGHT INTO
TUESDAY. WILL CONTINUE THE CHANCE FOR SOME SHOWERS INTO PARTS OF
OUR REGION TONIGHT...AT LEAST UNTIL THE SUBSIDENCE BECOMES
DOMINANT. THERE IS STILL SOME QUESTION AS TO WHEN THIS OCCURS...
BUT THE LATEST THINKING IS IT MAY TAKE MOST OF THE NIGHT.
COOLER OVERNIGHT TEMPERATURES ARE EXPECTED AS WINDS SHIFT TO THE
NORTH AND NORTHEAST BEHIND THE BACK DOOR COLD FRONT.
TUESDAY...
BACK-DOOR COLD FRONT CONTINUES TO MOVE WEST AS A HIGH PRESSURE
BUILDS OVER THE GULF OF MAINE. IT WILL TURN UNSEASONABLY COOL
WITH ONSHORE FLOW OFF ROUGHLY UPPER 40S DEGREE WATER. LIKELY TO
BE FAIRLY CLOUDY WITH A LONG FETCH OF EASTERLY FLOW UNDERGOING
WEAK UPSLOPE AS OVERRUNNING REMAINS PREVALENT ALONG THE LOW- TO
MID- LEVEL FRONTAL BOUNDARY SITUATED ACROSS AND TO THE WEST OF
NEW ENGLAND. AS SUCH CANNOT COMPLETELY RULE OUT A STRAY SHOWER OR
TWO. HOWEVER...EXPECTING MAINLY DRY CONDITIONS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
HIGHLIGHTS...
* HIGH PRESSURE ON WEDNESDAY WITH UNSEASONABLE TEMPS ALONG E COAST
* SEASONABLE TEMPS AND UNSETTLED WEATHER THURSDAY THROUGH THE WEEKEND
* POTENTIALLY TURNING CHILLY WITH SHOWERS INTO EARLY NEXT WEEK
MODELS AND CONFIDENCE...
LATEST 00Z GUIDANCE IS IN AGREEMENT SHOWING A STRONG WEST COAST
RIDGE WHICH WILL SUPPORT A BROAD/DEEP TROUGH SETTLING OVER THE ERN
HALF OF THE CONUS. CLOSER AT HOME...HIGH PRESSURE WILL BE BUILDING IN
THE GULF OF MAINE ON WEDNESDAY ALLOWING FOR DRY WEATHER. AS THE
TROUGH MOVES TOWARDS NEW ENGLAND...A NORTH ATLANTIC RIDGE WILL HOLD
STEADY...AND EVENTUALLY BLOCKS THE PROGRESSION OF THE TROUGH. A SFC
LOW PRES WILL INTENSIFIES OVER THE MID-ATLANTIC AS SEVERAL STRONG
SHORTWAVES DIG INTO THE BASE OF THE TROUGH. THAT LOW WILL THEN SLIDE
UP THE EAST COAST FRIDAY...AND DRAG A COLD FRONT ACROSS THE REGION
FRIDAY NIGHT INTO SATURDAY. STILL A LOT OF TIMING ISSUES WITH THIS
FORECAST BUT CONFIDENCE IS INCREASING THAT ASIDE FROM HIT OR MISS
SHOWERS IN THE MEDIUM RANGE...THE LONG TERM WILL BE VERY UNSETTLED
WITH POSSIBLE HEAVY RAIN/FLOODING ISSUES. SOLUTION SPREAD IS
GRADUALLY NARROWING BUT GFS/GEFS ARE CONTINUING LEADING HGT FALLS
INTO THE EAST FASTER THAN MOST OTHER GUIDANCE IN THE MID-LATE WEEK
TIME FRAME. ALTHOUGH LATEST EC GUIDANCE IS ON THE SLOWER SIDE OF THE
ENVELOPE WITH THE CMC ACTUALLY BEING IN THE MIDDLE OF THE SOLUTIONS
AND ENSEMBLES. TRENDS AND CONTINUITY OVER MULTIPLE DAYS HAVE BEEN
FAVORING SLOWER TIMING AS SUPPORTED BY THE AMPLIFIED NATURE OF THE
APPROACHING TROUGH AS WELL AS BLOCKY PATTERN IN THE ATLANTIC...WHICH
IS SUPPORTED WITH NAO TRENDING NEGATIVE. THEREFORE TRENDED THIS
FORECAST TOWARDS THE ENSEMBLES AS WELL AS WPC.
DETAILS...
WEDNESDAY...
HIGH PRESSURE WILL BUILD IN ACROSS THE GULF OF MAINE KEEPING MOST OF
THE REGION DRY. TEMPS WILL BE SEASONABLE EXCEPT ALONG THE EASTERN
COASTLINE AS ONSHORE FLOW WILL KEEP THE MARITIME AIR AROUND ON
WEDNESDAY. HOWEVER STALLED BOUNDARY ACROSS CENTRAL NY MAY ALLOW FOR
SOME ISO SHOWERS ACROSS WESTERN ZONES.
THURSDAY INTO SATURDAY...
STRONG ATLANTIC RIDGE TO THE EAST WILL SLOW THE PROGRESSION OF THE
DIGGING TROUGH AND STALL IT JUST WEST OF THE REGION. HOWEVER BY
THURSDAY...THE RIDGE WILL BREAK DOWN TEMPORARILY AS STRONG WESTERN
RIDGE PUSHES THE TROUGH TOWARDS THE NORTHEAST. EXPECT SEVERAL WEAK
WAVES TO DEVELOP AHEAD OF THIS TROUGH WHICH WILL APPROACH THE AREA.
HIT OR MISS SHOWERS/T-STORMS POSSIBLE ON THURSDAY WITH MORE
WIDESPREAD RAINFALL ON FRIDAY INTO SATURDAY. ALTHOUGH EXACT TIMING
OF EACH WAVE IS STILL UNCERTAIN...IT APPEARS THAT THE BEST CHANCE
FOR HIGHER PRECIP LOOKS TO BE FRIDAY NIGHT AS LOW PRESSURE SYSTEM
DEVELOPS ALONG THE FRONT. STRONG LLJ AND INCREASING MOISTURE
TRANSPORT SUPPORTS THE IDEA OF THE POSSIBILITY OF HEAVY RAINFALL.
ESPECIALLY SINCE THE TROUGH IS TAPPING INTO DEEP GULF MOISTURE
ALLOWING PWAT VALUES TO BE 3 STANDARD DEVIATIONS AWAY. INCREASING
CONFIDENCE THAT HEAVY RAINFALL WILL OCCUR BUT THERE IS STILL SOME
UNCERTAINTY ON EXACT TIMING...THEREFORE CONTINUED TO MENTION LIKELY
POPS FOR FRIDAY INTO SATURDAY. ALSO A LOW CONFIDENCE ON FLOODING
POTENTIAL AS FLASH FLOOD GUIDANCE IS APPROX 3 INCHES FOR MUCH OF THE
AREA. IN FACT WPC IS FORECASTING 2.5 INCHES OF QPF. SO IF THIS FRONT
STALLS/OR SLOWS DOWN ANY MORE WE MAY SEE SIGNIFICANT RAIN FALL
AMOUNTS NEAR FLASH FLOOD GUIDANCE.
A SEASONABLE BUT HUMID AIR MASS WILL OVERSPREAD THE REGION WITH SW
FLOW TAPPING INTO THE GULF...ADVECTING HIGHER DEWPOINTS AHEAD OF
THE TROUGH. FOG IS A POSSIBILITY ON WED NIGHT INTO THURSDAY AND
AGAIN ON FRIDAY. HIGHS WILL GENERALLY TOP OFF IN THE UPPER 60S TO
MID 70S WITH COOLER CONDITIONS ALONG THE COAST...ESP THE SOUTH COAST
DUE TO SOUTHERLY FLOW.
SUNDAY AND BEYOND...
MODELS DIFFER ON THE TIMING ON THE EXIT OF THE SYSTEM LATE SATURDAY
INTO SUNDAY. HAVE LOW CONFIDENCE ON WHEN THE FRONT WILL SWEEP
EASTWARD AS A SLIGHT CHANGE IN THE PATH COULD LEAD TO A SIGNIFICANT
CHANGE IN THE WEATHER FOR THE WEEKEND. OVERALL IT APPEARS THAT THE
STRONG ATLANTIC HIGH PRESSURE WILL STALL THE SYSTEM JUST EAST OF THE
REGION ON SUNDAY WITH AN UPPER LEVEL CUT OFF LOW FORMING. THIS LOW
WILL KEEP THE REGION SHOWERY AS WELL AS COOLER DUE TO THE COLD CORE
LOW WOBBLING OVER THE AREA.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH TUESDAY/...HIGH CONFIDENCE.
VFR. VERY LOW PROB OF AN ISOLATED SHOWER/TSTM NEAR BDL/BAF TOWARD
00Z. OTHERWISE DRY WEATHER PREVAILS. LIGHT/VARIABLE WINDS THIS
MORNING BECOME WESTERLY THIS AFTERNOON.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF. LIGHT/VARIABLE WINDS
BECOME WEST BY NOON.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF.
OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...
TUESDAY NIGHT INTO WEDNESDAY...HIGH CONFIDENCE.
EASTERLY WINDS. VFR WITH POSSIBLE MVFR CIGS ANTICIPATED. IFR
OVERNIGHT IS POSSIBLE AS WINDS SWITCH BACK TO THE SOUTH.
THURSDAY INTO FRIDAY...MODERATE CONFIDENCE.
VFR FOR THURSDAY. CONDITIONS DETERIORATING FRIDAY TO IFR WITH
INCREASING AREAL EXTENT OF SHRA AND POSSIBLE TSRA. SOUTHERLY WINDS
ON THURSDAY CONTINUING INTO FRIDAY WITH GUSTS UP AROUND 25-30 KTS
POSSIBLE.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
HIGH CONFIDENCE THROUGH TUESDAY.
WINDS AND SEAS EXPECTED TO REMAIN BELOW SMALL CRAFT CRITERIA
THROUGH TODAY.
WINDS INCREASE AS A BACK DOOR COLD FRONT MOVES FROM NORTHEAST TO
SOUTHWEST TONIGHT. SMALL CRAFT ADVISORIES MAY AGAIN BE NECESSARY
FOR A TIME TONIGHT INTO TUESDAY...THOUGH SEAS LOOK TO REMAIN
BELOW 5 FEET. AT THIS POINT...DO NOT HAVE ENOUGH CONFIDENCE IN
REACHING 25 KT GUSTS OR 5 FOOT SEAS TO ISSUE SMALL CRAFT
ADVISORIES NOW. IT DOES REMAIN A POSSIBILITY...AND IS SOMETHING
FUTURE SHIFTS WILL HAVE TO CONSIDER.
OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...
TUESDAY NIGHT INTO WEDNESDAY...MODERATE CONFIDENCE.
HIGH PRESSURE WILL BUILD OVER THE EASTERN WATERS TUESDAY NIGHT
AND INTO WEDNESDAY. EXPECT EASTERLY WINDS TO CONTINUE...ALLOWING
FOR EASTERLY SWELL TO BUILD. FOG AND DRIZZLE POSSIBLE BY LATE
WEDNESDAY AS FLOW SWITCH TO THE SOUTH. SCA MAY BE NEEDED FOR THE
PERIOD.
THURSDAY INTO FRIDAY...LOW CONFIDENCE.
LINGER 5FT SEAS TO START INCREASING THROUGHOUT THE DAY WITH THE
POSSIBILITY FOR A FEW SHOWERS ON THURSDAY. CONDITIONS DETERIORATE
ON FRIDAY AS FRONT APPROACHES THE WATERS. SEAS AND WINDS WILL
BUILD IN RESPONSE AS WELL AS HEAVY DOWNPOURS AND ISO THUNDER. SCA
WILL BE NEEDED.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...BELK/DUNTEN
NEAR TERM...BELK/NOCERA/DUNTEN
SHORT TERM...BELK
LONG TERM...DUNTEN
AVIATION...BELK/NOCERA/DUNTEN
MARINE...BELK/DUNTEN
AREA FORECAST DISCUSSION
NWS ALBANY NY
924 AM EDT MON MAY 12 2014
.SYNOPSIS...HIGH PRESSURE SLIDES OUT TO SEA OFF THE MID ATLANTIC
COAST TODAY. AFTER A DELIGHTFULL SUNNY WARM DAY OUR WEATHER WILL
TURN INCREASINGLY UNSETTLED AS THE WEEK PROGRESSES. LATE TODAY A
BACK DOOR COLD FRONT WILL DROP SOUTH THROUGH THE REGION...STALLING
ACROSS THE MID ATLANTIC STATES. BY MIDWEEK A LARGE FRONTAL SYSTEM
IN THE GREAT LAKES WILL PUSH TOWARD THE EASTERN SEABOARD.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 915AM SOME HI CLOUDS ASSOC WITH CONVECTIVE DEBRIS FROM THE
OVERNIGHT OHIO MCS WERE SPILLING OVER S PRTNS OF FCA...BUT THESE
SHOULD THIN AND SHIFT SOUTH DURING THE REST OF THE DAY...UNTIL
THE NEXT RIDGE ROLLER STARTS SPILLING CI/MID INTO FCA TWRD EVNG.
TEMPS ARE A FEW DEG ABV CURRENT FCST...AND NUDGED MAXES 1-3 DEG
BASED ON CURRENT TEMPS AND 06UTC MOS/MET. HRRR AND LOCAL WRF REFLECTIVITIES
SUGGEST STILL THE POTENTIAL FOR SOME SHOWERS DEVELOPING ACROSS THE
CATSKILLS. ALTHOUGH CONVECTIVE TEMP AT ALB ON MRNG SNDGS IS 103F.
WILL CONT POPS BUT LOWERED TO SLGT CHC THERE.
THE IR SATELLITE IMAGERY ALONG WITH SURFACE FRONT ANALYSIS
REVEALS A BACKDOOR COLD FRONT HAS REACHED THE ST LAWRENCE VALLEY.
ONE MCS THAT MOVED THROUGH OHIO INTO WV HAS DISSIPATED TO -SHRA AND
CLOUDS...ANOTHER MOVING FM WI INTO MICHIGAN IS ALSO WEAKENING.
COMBINATION OF THIS FRONT AND CONVECTIVE CLOUD DEBRIS WILL BRING
AN INCREASE IN HIGH AND MID LEVEL MOISTURE ACROSS THE REGION LATE
TODAY. CLOUD OPAQUENESS WILL VARY BUT ENOUGH SUNSHINE SHOULD
RESULT IN A RATHER MILD AFTERNOON WITH HIGHS AT OR JUST ABOVE 80F
FOR SEVERAL VALLEY LOCATIONS AND MAINLY 70S FOR THE REMAINDER OF
THE REGION.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
INTO THIS EVENING...EXPERIENTIAL HIRES REFLECTIVITY FORECASTS
FROM SPC/HRRR/WRF SUGGEST WIDESPREAD CONVECTION DEVELOPS ALONG A
WARM FRONT NEAR THE NY/PA BORDER WITH ADDITIONAL SHOWER ACTIVITY
ALONG THE BACKDOOR COLD FRONT INTO THE DACKS. WE WILL INCREASE
POPS INTO THE SLIGHT CHANCE TO CHANCE CATEGORY FOR THE REGION WITH
THE HIGHER VALUES INTO THE CATSKILLS AND MID HUDSON VALLEY.
OTHERWISE...THERE WILL BE A NOTABLE INCREASE AND THICKENING CLOUD
COVER ACROSS THE REGION WITH NEAR SEASONABLE OVERNIGHT LOWS FOR
THE REGION WITH SLIGHTLY COOLER VALUES ACROSS THE LAKE GEORGE
SARATOGA REGION AND WESTERN NEW ENGLAND AS SURFACE HIGH ACROSS
NORTHEAST CANADA IS EXPECTED TO BUILD AND CREST INTO NEW ENGLAND
TONIGHT.
TUESDAY THROUGH WEDNESDAY...CONFIDENCE IS NOT PARTICULARLY HIGH
WITH RESPECT TO PLACEMENT OF HIGHER PROBABILITIES OF
SHOWERS/TSTORMS. NCEP MODEL SUITE AND INTERNATIONAL GUIDANCE FAVOR
AN IDEA OF A WARM FRONT LIFTING EAST-NORTHEAST ACROSS THE REGION
WITH RISING HEIGHTS ALOFT FOR A MORE ANTICYCLONIC FLOW.
FURTHERMORE...BEST LOW LEVEL JET FORCING AND THETA-E ADVECTIVE
PROPERTIES REMAIN UPSTREAM FROM THE LOCAL SERVICE AREA WHICH TOO
LIMITS A MORE ORGANIZED PRECIPITATION EVENT. SO WE WILL KEEP POPS
INTO THE SLIGHT CHANCE FOR PORTIONS OF NEW ENGLAND TO CHC-SCT
VALUES FOR EASTERN NY /THE HIGHER POP VALUES WEST OF THE HUDSON
RIVER/. GIVEN THE CONSIDERABLE CLOUD COVER EXPECTED...WE WILL KEEP
TEMPERATURES AROUND SEASONABLE LEVELS DURING THIS TIME FRAME WITH
A BLEND OF THE WARMER MAV GUIDANCE AND COOLER MET GUIDANCE WHICH
IS SOMEWHAT CLOSE TO THE EXPERIMENTAL ECMWF MOS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
STRONG RIDGING WILL BE DEPARTING THE EASTERN SEABOARD AT THE START
OF THE EXTENDED PERIOD...WHILE A DIGGING TROUGH MOVES ACROSS THE
UPPER MIDWEST/GREAT PLAINS AND TOWARDS THE GREAT LAKES AND OHIO
VALLEY.
INITIALLY...THE BEST FORCING FOR PRECIP WILL BE LOCATED WEST OF OUR
AREA...AND WHILE SOME STRAY SHOWERS/THUNDERSTORMS CANT BE RULED OUT
FOR WESTERN PARTS OF THE CWA...IT LOOKS TO BE MAINLY DRY AND MILD
FOR WED NIGHT INTO THURSDAY. MINS ON WED NIGHT WILL BE IN THE
50S...WITH HIGHS ON THURSDAY WELL INTO THE 70S...AS 850 HPA TEMPS OF
12-14 DEGREES C WILL SUPPORT QUITE A WARM DAY.
EVENTUALLY...THE UPPER LEVEL TROUGH AND ASSOCIATED SLOW MOVING SFC
FRONT WILL MOVE CLOSER TO OUR AREA AND PASS THROUGH FROM WEST TO
EAST FOR THE LATE WEEK PERIOD. THIS WILL LIKELY BRING A BAND OF
HEAVY RAIN SHOWERS ACROSS OUR REGION FOR SOMETIME BETWEEN THURSDAY
NIGHT AND SATURDAY MORNING. WITH PWAT VALUES SURGING TO AROUND 1.50
INCHES...A PERIOD OF HEAVY RAIN WILL BE POSSIBLE WHEN THE BEST
FORCING MOVES ACROSS THE AREA. IN ADDITION...THERE MAY BE SOME
EMBEDDED CONVECTIVE ELEMENTS WITHIN THE BAND OF HEAVY RAIN
SHOWERS...AS SHOWALTER VALUES DROPPING BELOW ZERO SHOW THERE MAY BE
ELEVATED INSTABILITY...WHICH CAN ALSO CONTRIBUTE TO THE HEAVY RAIN
POTENTIAL.
IT WILL BE MILD AHEAD OF THE FRONTAL BOUNDARY WITH MINS IN THE MID
50S TO LOW 60S FOR THURSDAY NIGHT...AND TEMPS NEAR 70 ON FRIDAY.
COOLER TEMPS WILL START TO MOVE IN FROM THE WEST FOR FRIDAY
NIGHT...AS THE BOUNDARY STARTS TO CROSS THE REGION...WITH MID 40S TO
MID 50S...AND HIGHS ON SATURDAY MAINLY IN THE 60S.
OVER THE WEEKEND...THERE MAY BE SOME LINGERING RAIN SHOWERS...AS THE
UPPER LEVEL TROUGH WILL STILL BE MOVING ACROSS THE AREA. IT/S STILL
HARD TO SAY IF THE CORE OF THE UPPER LEVEL CLOSES OFF AND IF IT WILL
CROSS OVER OUR AREA...OR IF IT WILL JUST PASS OFF TO OUR NORTH. IN
EITHER CASE...A CONTINUED CHANCE FOR RAIN SHOWERS IS
JUSTIFIED...ALONG WITH COOLER TEMPS FOR SAT NIGHT INTO SUNDAY.
&&
.AVIATION /13Z MONDAY THROUGH FRIDAY/...
A BATCH OF SCT-BKN MID LEVEL CLOUDS AROUND 10 KFT HAVE MOVED ACROSS
THE REGION EARLY THIS MORNING. THESE CLOUDS HAVE STARTED TO THIN OUT
AND MOVE AWAY FOR NOW...BUT SOME ADDITIONAL MID AND HIGH LEVEL
CLOUDS CAN BE SEEN UPSTREAM ON IR SATELLITE IMAGERY.
DURING THE DAY TODAY...SOME DIURNAL CU WILL DEVELOP...ALONG WITH THE
AFOREMENTIONED PASSING MID AND HIGH LEVEL CLOUDS. VFR CONDITIONS
WILL CONTINUE FOR ALL TERMINALS THROUGHOUT THE ENTIRE DAY. AT THIS
POINT...THE THREAT FOR RAIN SHOWERS APPEARS TO BE MINIMAL...AS ANY
ACTIVITY SHOULD REMAIN TO THE WEST OF THE HUDSON VALLEY TAF
SITES...SO NO RAIN SHOWERS WILL BE MENTIONED IN THE TAF AT THIS
TIME. WINDS FROM A W-SW DIRECTION WILL INCREASE TO ABOUT 5-10 KTS
DURING THE BEST DAYTIME MIXING IN THE AFTN/EARLY EVENING.
BY EVENING...MID LEVEL CLOUDS WILL INCREASE AND BECOME BKN FOR ALL
SITES. WINDS WILL SWITCH TO A N-NW DIRECTION AS A BACKDOOR FRONTAL
BOUNDARY MOVES THROUGH THE AREA...BUT WIND SPEEDS SHOULD DECREASE TO
5 KTS OR LESS FOR TONIGHT. THE THREAT FOR RAIN SHOWERS CONTINUES TO
BE RATHER LOW...SO WILL CONTINUE WITH A DRY TAF FORECAST FOR
TONIGHT WITH CONTINUED VFR CONDITIONS.
OUTLOOK...
TUESDAY THROUGH THURSDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE
OF SHRA...TSRA.
FRIDAY: HIGH OPERATIONAL IMPACT. LIKELY SHRA...TSRA.
FRIDAY NIGHT THROUGH SATURDAY: MODERATE OPERATIONAL IMPACT. LIKELY
SHRA.
&&
.FIRE WEATHER...
RH VALUES TODAY WILL LOWER TO BETWEEN 25 AND 35 PERCENT AS HIGH
TEMPERATURES REACH THE MID 70S TO LOWER 80S. WINDS ARE EXPECTED TO
BE 10 MPH OR LESS. THERE IS A CHANCE OF SHOWERS DURING THE LATE
AFTERNOON HOURS.
THE RH LEVELS RECOVER TONIGHT TO BETWEEN 60 AND 90 PERCENT TONIGHT
WITH A LIGHT WIND. THE CHANCE FOR SHOWERS WILL CONTINUE FOR THE
ENTIRE REGION WITH THE HIGHER PROBABILITIES WEST OF THE HUDSON
RIVER.
&&
.HYDROLOGY...
NO WIDESPREAD HYDROLOGIC ISSUES ARE EXPECTED OVER THE NEXT SEVERAL
DAYS.
A MAINLY DRY AND WARM DAY IS EXPECTED TODAY WITH THE CHANCE FOR
SHOWERS ON THE INCREASE LATE IN THE DAY. THIS CHANCE FOR SHOWERS
WILL CONTINUE FOR MOST THE REGION WITH THE INCREASE PROBABILITY
FOR SOME HEAVIER RAINFALL TOWARD THE END OF THIS WEEK.
HOWEVER...ANY RAINFALL DURING THE EARLY AND MIDDLE PART OF THE
WEEK WILL BE LIGHT AND HAVE LITTLE IMPACT ON AREA STREAMS AND
RIVERS. THE RAINFALL LATER IN THE WEEK COULD BE HEAVY AND WE WILL
NEED TO WATCH NUMERICAL TRENDS CLOSELY.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...SNYDER
NEAR TERM...BGM/SNYDER
SHORT TERM...BGM
LONG TERM...FRUGIS
AVIATION...FRUGIS
FIRE WEATHER...BGM
HYDROLOGY...BGM
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
1046 AM EDT MON MAY 12 2014
.UPDATE...
HI RES MODELS ARE STILL IN GOOD AGREEMENT WITH ISOLATED TO
SCATTERED SHOWER AND THUNDERSTORM DEVELOPMENT THIS AFTERNOON BUT
SOME DIFFERENCES IN TIMING. HRRR IS QUICKER WITH INITIALIZATION
THAN THE LOCAL WRF...16Z COMPARED TO ABOUT 20Z. OVERALL THE
POP FORECAST IS ON TRACK AND DID NOT ADJUST THE SLIGHT
CHANCE/CHANCE FOR THIS AFTERNOON. I DID HOWEVER END UP PUSHING
BACK THE INITIATION TO 17Z. FORECAST DEW POINTS WERE A LITTLE ON
THE LOW SIDE SO INCREASED THEM INTO THE AFTERNOON.
11
&&
.PREV DISCUSSION... /ISSUED 740 AM EDT MON MAY 12 2014/
SHORT TERM /TODAY THROUGH TUESDAY/...
WEAK UPPER-LEVEL RIDGING CONTINUES OVER THE REGION TODAY...THEN
BEGINS SHIFTING EAST INTO THE WESTERN ATLANTIC TUESDAY. THE RIDGE
DOES NOT APPEAR TO BE DOMINANT ENOUGH TO SHUT OFF ALL CHANCES FOR
CONVECTION BUT SHOULD LIMIT COVERAGE TO SCATTERED AT BEST AND
DIURNALLY ORIENTED. MID-LEVEL LAPSE RATES AROUND 6DEGC/KM OR LESS
KEEP INSTABILITY LIMITED WITH ANY THUNDERSTORMS EXPECTED TO REMAIN
BELOW SEVERE LIMITS.
FOR EARLY THIS MORNING...LOW-LEVEL MOISTURE AND MOIST SOILS ONCE
AGAIN CONTRIBUTING TO AREAS OF FOG WITH PATCHY AREAS OF DENSE FOG.
COVERAGE IS LESS THAN YESTERDAY MORNING AND IS EXPECTED TO REMAIN SO
THIS MORNING AND IT DOES NOT APPEAR THAT THE AREAL COVERAGE OF
VISIBILITIES BELOW 1/4 MILE WOULD BE SUFFICIENT FOR A DENSE FOG
ADVISORY.
20
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
LARGE HIGH AMPLITUDE H5 TROUGH OVER CENTRAL US FCST TO CONTINUE
PROGRESSING SLOWLY EASTWARD REST OF THE WEEK. BY 12Z WED...TROUGH
AXIS WILL STILL BE CENTERED ALONG 90W LONGITUDE BUT SWLY FLOW
ALOFT AND WARM/MOIST ADVECTION AHEAD OF IT WILL INCREASE ACROSS
THE SE STATES BRINGING CLOUDS AND SOME SCT SHRA WITH IT.
INSTABILITY QUITE HIGH OVER THE CENTRAL STATES. HOWEVER AS THE
TROUGH PUSHES EAST EACH DAY...LOW LEVEL FLOW PROGGED TO WEAKEN AND
INSTABILITY DECREASES SOME. BY 12Z THURSDAY WHEN THE FRONT
ASSOCIATED WITH THE UPPER TROUGH MOVES INTO THE STATE...MLCAPE
VALUES ONLY AROUND 250-500 J/KG AND 0-1KM BULK SHEAR ONLY
10-20KTS. COULD ALSO SEE UPSTREAM CONVECTION ALONG THE CENTRAL
GULF COAST AGAIN INHIBIT STORM DEVELOPMENT INLAND. DEEP SHEAR
PROGGED TO REMAIN QUITE STRONG WITH 0-6KM BULK SHEAR 12Z THUR
40-50KTS...INDICATIVE OF STRONG TEMP GRADIENT ALONG FRONT AS WELL.
EVEN WITH STRONG DEEP SHEAR...WITH LACK OF INSTABILITY AND LOW
LEVEL SHEAR...SVR STORMS APPEAR UNLIKELY AT THIS TIME. COULD SEE
PERIOD OF MDT TO HEAVY RAIN ON THURS...BUT WITH SLOW PROGRESSIVE
NATURE OF SYSTEM...APPEARS ANY ONE AREA SHOULD NOT SEE MORE THAN
2 INCHES THROUGH 12Z FRI.
AFTER FRONT AND ASSOCD SHORT WAVE PUSH THROUGH...UPPER TROUGH SLOW
TO PUSH OUT OF EASTERN CONUS. ANOTHER WAVE IN NW FLOW OVER THE
CENTRAL PLAINS PROGGED TO MOVE INTO THE TN VALLEY SAT. QUITE A BIT
OF DISCREPANCY BETWEEN MED RANGE MODELS /00Z GFS...ECMWF AND CMC/
ON THIS FEATURE...ECMWF SOMEWHAT SLOWER. WITH DRY AIR MASS EXPECTED
AS THIS SECOND WAVE APPROACHES...HAVE BACKED OFF A LITTLE ON POPS.
NW FLOW CAN BE TRICKY IN THE WARM SEASON SO WILL NEED TO MONITOR
THIS. INSTABILITY PROGGED TO BE LOW BUT NOT ZERO.
SNELSON
AVIATION...
12Z UPDATE...
WIDE RANGE OF LIFR TO VFR CONDITIONS...MAINLY DUE TO FOG..CURRENTLY
ACROSS THE FORECAST AREA. MVFR VISIBILITIES PREDOMINATE WITH
SCATTERED VFR AND A FEW LOCAL LIFR VISIBILITIES. EXPECT MAINLY VFR
CONDITIONS AFTER 14Z OUTSIDE OF ISOLATED TO SCATTERED CONVECTION
EXPECTED BETWEEN 18-02Z. SCATTERED CUMULUS DEVELOPMENT AROUND 2-3KFT
BY 14 THROUGH 18Z... LIFTING TO 4-5KFT AFTER 18Z. WINDS WILL BE
LIGHT..LESS THAN 5KTS...AND SOMEWHAT VARIABLE IN DIRECTION THROUGH
14Z BUT WILL FAVOR SOUTHEAST. WIND SPEEDS WILL INCREASE TO 5-9KTS
AFTER 14Z WITH DIRECTION VARYING BETWEEN SOUTHWEST AND SOUTHEAST.
//ATL CONFIDENCE...12Z UPDATE...
MEDIUM TO HIGH CONFIDENCE ON ALL ELEMENTS.
20
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 89 65 88 64 / 30 20 30 10
ATLANTA 87 68 86 66 / 30 20 30 10
BLAIRSVILLE 84 61 83 62 / 30 20 30 20
CARTERSVILLE 87 63 86 65 / 30 20 30 30
COLUMBUS 91 68 90 67 / 30 20 30 10
GAINESVILLE 85 66 84 65 / 30 20 30 20
MACON 90 65 89 65 / 30 20 30 10
ROME 87 63 86 63 / 30 20 30 30
PEACHTREE CITY 89 64 88 63 / 30 20 30 10
VIDALIA 90 67 89 68 / 30 20 30 5
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...11
LONG TERM....NLISTEMAA
AVIATION...11
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1052 AM CDT MON MAY 12 2014
.DISCUSSION...
328 AM CDT
AMONG THIS MORNING`S MANY RECAST CHALLENGES ARE TEMPS
TODAY...PRECIP AND CONVECTIVE TRENDS THROUGH TONIGHT...RAIN CHANCES
LATER IN THE WEEK WITH SECONDARY CYCLONE...AND MAGNITUDE OF COLD AIR
MASS LATER THIS WEEK.
IT IS FUNNY HOW OFTEN CONFIDENCE IN A FORECAST DECREASES AS THE
FORECAST TIME NEARS. LAST NIGHT AT THIS TIME WAS FAIRLY CONFIDENT
THAT CONVECTION TO OUR WEST WOULD DISSIPATE BEFORE MAKING IT INTO
OUR AREA WITH THE FOCUS SHIFTING NORTH INTO WISCONSIN...BUT PLAYING
A GAME OF METEOROLOGICAL CHICKEN WITH THE MCS OVER IOWA THAT
CONTINUES TO CHARGE EAST TOWARD THE MISSISSIPPI RIVER EARLY THIS
MORNING AND AM GROWING INCREASINGLY TEMPTED TO FLINCH AND BUMP UP
POPS SOME THIS MORNING. THE ATMOSPHERE OVER NORTHERN ILLINOIS WAS
SIGNIFICANTLY MODIFIED AND STABILIZED BY SUNDAY EVENING`S
CONVECTION...BUT CONTRASTING THE 00Z SOUNDINGS FROM DVN AND ILX SHOW
JUST HOW NEARBY THE CONVECTIVELY MOIST AND UNSTABLE AIR MASS LIES.
THE COMPOSITE SECONDARY WARM FRONT/OUTFLOW BOUNDARY EXTENDING
ROUGHLY FROM KLAF TO JUST SOUTH OF THE QUAD CITIES IS LIFTING NORTH
AND/OR WASHING OUT WITH WINDS ACROSS NORTHERN ILLINOIS VEERING MORE
SOUTHERLY AND HIGHER DEWPOINTS CREEPING NORTHWARD.
SHORT RANGE GUIDANCE IS STRONGLY DIVIDED IN THE HANDLING OF THE MCS
OVER IOWA...WITH ONE CAMP SHOWING A FAIRLY RAPID DEMISE OVER THE
NEXT SEVERAL HOURS WITH ONLY SCTD SHRA/ISOLD TSRA POTENTIALLY MAKING
IT INTO NW CWA WHILE ANOTHER CAMP OF MODELS IS MORE AGGRESSIVE IN
BRINGING STORMS EAST ACROSS THE CWA THROUGH THE MORNING. THE
IMPLICATIONS OF HOW THIS SCENARIO EVOLVES ARE HUGE FOR
TEMPS...WINDS...AND SUBSEQUENT CONVECTIVE CHANCES WITH THE COLD
FRONT. CONFIDENCE IS NOT HIGH...BUT LEANING TOWARD STAYING THE
COURSE WITH THINKING FROM PREVIOUS FORECASTS WHICH SUGGEST A QUICK
WEAKENING TREND WITHOUT MUCH CONVECTION MAKING IT FAR INTO OUR CWA.
RECENT REGIONAL RADAR AND SATELLITE TRENDS SEEM TO FINALLY BE
SUPPORTING THIS LINE OF THINKING WITH CLOUD TOPS BEGINNING TO
QUICKLY WARM WITH DECREASING COVERAGE AND INTENSITY OF THE STORMS.
SEVERAL MODELS ARE HINTING AT THE POTENTIAL FOR ADDITIONAL SCTD
CONVECTION DEVELOPING IN THE WARM/MOIST/UNSTABLE AXIS EXTENDING FROM
DOWNSTATE IL NNE INTO NNW INDIANA. DESPITE LEANING TOWARD THE DRIER
SOLUTIONS FOR TODAY WILL BE MAINTAINING CHANCE POPS ACROSS THE CWA
TO ALLOW FOR EITHER THE IOWA MCS PERSISTING LONGER AND/OR
MOIST/UNSTABLE AXIS THIS AFTERNOON.
HIGH TEMPS AND EVEN GUSTINESS OF THE WINDS TODAY WILL HINGE ON CLOUD
COVER AND PRECIP. IF THE MCS CONTINUES TO QUICKLY WEAKEN AND DEBRIS
CLOUDINESS DISSIPATE...THEN IT SHOULD ALLOW FOR PARTIAL SUNSHINE AND
WHICH COULD SEND TIMES CLIMBING WELL INTO THE 80S AND ABOVE
OBJECTIVE GUIDANCE. THIS IS THE CURRENT FORECAST AND RATHER THAN
FLIP ONLY TO HAVE THE DAY SHIFT HAVE TO FLOP WILL STAY THE COURSE
WITH ABOVE GUIDANCE HIGHS AND IF IT BECOMES CLEAR THAT CLOUDS WILL
STICK AROUND THE DAY SHIFT CAN BACK OFF ON TEMPS WITH A MORNING
UPDATE. THERE ARE A HANDFUL OF CONVECTIVE ALLOWING MODELS SHOWING A
RELATIVE MIN IN CONVECTIVE REDEVELOPMENT OVER IOWA TONIGHT FOLLOWING
THE STABILIZING EFFECTS OF CURRENT MCS...BUT WITH GREATER NUMBER OF
MODELS SUPPORTING RE-DEVELOPMENT PLAN TO HANG ON TO LIKELY POPS
TONIGHT AS THE FRONT MOVES EAST TOWARD THE AREA. MORE MARGINAL AND
UNIDIRECTIONAL SHEAR PROFILES AND DECREASING INSTABILITY AT NIGHT
BOTH WOULD ARGUE FOR STORMS MOVING INTO THE AREA TONIGHT TO BE IN A
WEAKENING PHASE WITH SEVERE THREAT DECREASING WITH TIME AND EASTWARD
EXTENT TONIGHT.
RAIN COULD LINGER INTO TUESDAY...ESPECIALLY IN THE MORNING AND OVER
THE EASTERN CWA BEFORE BETTER FORCING PUSHES OFF TO THE EAST AND
DRIER AIR MOVES IN. TUESDAY AFTERNOON COULD BE SALVAGEABLE FOR MANY
AREAS WITH NEAR NORMAL HIGHS AND LIKELY AN END TO THE PRECIPITATION.
LATER WEDNESDAY INTO THURSDAY GUIDANCE REALLY RUNS THE GAMUT IN
HANDLING OF THE SECONDARY SHORTWAVE TROUGH ROUNDING THE BASE OF THE
DEEP UPPER TROUGH THAT WILL BECOME ESTABLISHED OVER EASTERN NOAM.
WPC PREFERRED MODEL CHOICE WAS THE 00Z ECMWF WHICH IS CLOSE TO THE
MIDDLE OF THE ROAD OF POSSIBLE SOLUTIONS AND SAW NO REASON TO
DEVIATE FROM THIS LINE OF THINKING. ASSUMING THE ECMWF VERIFIES A
SECONDARY WAVE OF LOW PRESSURE WILL TRACK NORTHEAST ALONG THE
PASSING COLD FRONT AND PRODUCE A PERIOD OF RAIN/SHOWERS...MAINLY
SOUTHEASTERN HALF OF THE CWA. REMARKABLY SOME GUIDANCE HAS 850MB
TEMPS DROPPING TO 0 TO -2C DURING THE PRECIP WHICH WHILE COLD IS
PROBABLY NOT COLD ENOUGH FOR ANY MIXED PRECIP GIVEN THE TIME YEAR
BUT PERILOUSLY CLOSE. GIVEN THE MODEL SPREAD EARLY IN THE PERIOD
PROBABLY NOT SURPRISING THAT THERE IS SUBSTANTIAL SPREAD IN THE
INTENSITY OF THE UPPER TROUGH/LOW LATE IN THE WEEK AND SUBSEQUENT
TEMPS WITH FAR MORE AMPLIFIED AND COLD SOLUTION IN THE ECMWF
SUPPORTIVE OF TEMPS COLDER THAN WHAT OUR CURRENT FORECAST BUT WITH
SO MUCH UNCERTAINTY SO NO REASON TO STRAY FROM THE BLENDED MODEL
CONSENSUS.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* GUSTY SOUTHERLY TO SOUTH-SOUTHWESTERLY WINDS TODAY.
* TIMING AND CHANCES OF ADDITIONAL TSRA TODAY AND TONIGHT.
* LOWER MVFR CIGS POSS TUESDAY MORNING.
KREIN
//DISCUSSION...UPDATED 16Z...
ADDED TEMPO GROUP FOR TSRA TO ALL TAFS FOR EARLY THIS AFTERNOON.
FOLLOWING AN MCV OVER ERN IOWA AND TIMING WOULD BRING ANY
ASSOCIATED THUNDERSTORM ACTIVITY TO THE RFD AREA BY ARND 18Z AND
THE CHICAGO AREA BY ARND 19-20Z. THE CONVECTIVE ACTIVITY CURRENTLY
ASSOCIATED WITH THE SYSTEM IS ON A WEAKENING TREND...BUT IT WILL
BE MOVING INTO A MORE CONVECTIVELY FAVORABLY ENVIRONMENT OVER THE
NEXT COUPLE HOURS...SO WILL NEED TO BE MONITORED CLOSELY.
KREIN
UPDATED 12Z...
THE CHANCES AND TIMING OF ADDITIONAL CONVECTIVE ACTIVITY WILL BE
THE PRIMARILY WEATHER CONCERN ACROSS THE NORTHERN ILLINOIS
TERMINALS AGAIN TODAY AND TONIGHT.
THE THREAT FOR CONVECTIVE ACTIVITY OVER OR NEAR THE TERMINALS
THROUGH THE DAY TODAY APPEARS LOW...BUT NOT ZERO. A WARM...MOIST
AND UNSTABLE AIR MASS WILL BE IN PLACE ACROSS THE AREA TODAY.
HOWEVER...WITH THE LACK OF ANY SIGNIFICANT TRIGGER MECHANISM TO
GET CONVECTION GOING...IT APPEARS THAT ANY ACTIVITY THAT DEVELOPS
ACROSS THE AREA DURING THE DAY WILL BE OF FAIRLY LOW AREAL
COVERAGE. WITH THIS IN MIND...I WILL CONTINUE TO KEEP THE MENTION
OF THUNDER OUT OF THE TAF THROUGH THE DAY. THE NEXT MAIN THREAT FOR A
PERIOD OF POSSIBLY MORE WIDESPREAD SHOWERS AND STORMS WILL TONIGHT AHEAD
OF AN APPROACHING COLD FRONT.
WINDS ARE EXPECTED TO BE GUSTY UP AROUND 25 KT OUT OF THE SOUTH-
SOUTHWEST DURING THE DAY TODAY. A COLD FRONT WILL THEN SHIFT
ACROSS THE AREA AROUND DAYBREAK ON TUESDAY. THIS WILL RESULT IN A
WESTERLY WIND SHIFT ACROSS THE AREA...ALONG WITH THE POTENTIAL FOR
SOME LOWER CIGS TO MOVE ACROSS THE AREA.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM-HIGH CONFIDENCE IN WIND FORECAST.
* LOW CONFIDENCE CONVECTIVE TIMING AND COVERAGE TODAY AND TONIGHT.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
* TUESDAY NIGHT...VFR.
* WEDNESDAY...SLIGHT CHANCE OF PM SHRA.
* THURSDAY...CHANCE OF SHRA.
* FRIDAY...SLIGHT CHANCE OF SHRA.
* SATURDAY AND SUNDAY...DRY/VFR.
KJB
&&
.MARINE...
323 AM CDT
AN AREA OF LOW PRESSURE ACROSS THE MID MISSOURI VALLEY EARLY THIS
MORNING WILL TRACK NORTHEASTWARD TOWARDS LAKE SUPERIOR BY TONIGHT.
AS THIS OCCURS...AN ASSOCIATED WARM FRONT IS EXPECTED TO LIFT
NORTHWARD UP THE LAKE THROUGH TONIGHT. AREAS OF FOG...POTENTIALLY
DENSE WILL BE LIKELY ACROSS PORTIONS OF THE LAKE TODAY AND TONIGHT
AS THIS FRONT...AND THE ACCOMPANYING VERY MOIST AIR MASS MOVES OVER THE
COOL LAKE WATERS. A MARINE DENSE FOG ADVISORY MAY BE NEEDED.
THE OTHER CONCERN WILL BE THE WINDS TODAY AND TONIGHT WITH THIS WARM
FRONT LIFTING UP THE LAKE. THE WINDS SOUTH OF THIS WARM FRONT WILL
BECOME SOUTHERLY AROUND 25 KT TODAY...WHILE NORTH OF THE WARM
FRONT...SOME STOUT EASTERLY WINDS WILL BE LIKELY. THESE GUSTY
SOUTHERLY WINDS WILL RESULT IN LIKELY RESULT IN NEAR SMALL CRAFT
ADVISORY WINDS OVER THE ILLINOIS AND INDIANA NEAR SHORE WATERS BY
MIDDAY. HOWEVER...IN SPITE OF THIS...I HAVE OPTED TO HOLD OFF ON AN
ADVISORY DUE TO THERE BEING SOME QUESTION AS TO EXACTLY HOW STRONG
THE WINDS WILL BE OVER THE NEAR SHORE WATERS. IN ADDITION...WITH THE
OFFSHORE COMPONENT...WAVES WILL LIKELY NOT BUILD OVER 4 FT IN THE
NEAR SHORE WATERS. THE POTENTIAL IS CERTAINLY THERE FOR 25+ KT
OFFSHORE FLOW TODAY...WITH THE POTENTIAL NEED FOR AN UPGRADE TO A
SMALL CRAFT ADVISORY.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM MONDAY.
DENSE FOG ADVISORY...LMZ567-LMZ669-LMZ671-LMZ868-LMZ870-LMZ872
UNTIL 3 PM MONDAY.
DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565
UNTIL 1 AM TUESDAY.
&&
$$
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[top]
Area Forecast Discussion
National Weather Service Lincoln IL
949 AM CDT Mon May 12 2014
.DISCUSSION...
ISSUED 949 AM CDT Mon May 12 2014
Another warm and humid day is unfolding across central Illinois,
as 14z/9am temps have already risen well into the 70s. The area
remains convection-free for the time being, but as weak capping is
broken over the next couple of hours widely scattered thunderstorms
will begin to develop. Enhanced Cu field is currently evident on
visible satellite imagery from Arkansas northeastward across the
eastern half of the KILX CWA. Latest mesoanalysis from SPC
indicates deep layer moisture convergence maximized from southeast
Missouri into southeast Illinois, where HRRR shows scattered
thunderstorm development between now and 18z. Elsewhere around
central Illinois, convection will likely remain more isolated in
nature until later this afternoon when cold front begins to
approach from the west. Front is still progged to reach the area
after dark tonight, so best chances for widespread convection will
likely hold off until late afternoon/early evening in the Illinois
River Valley, then further east across the remainder of the area
overnight.
Barnes
&&
.AVIATION...
ISSUED 641 AM CDT Mon May 12 2014
VFR conditions will start each TAF most of the day. Mid and high
clouds will remain over the area this morning and then around noon
cigs will fall to around 6kft at all TAF sites, as CU thickens
ahead of the cold front. Thunderstorms are expected to develop
late this afternoon to the west of the area and then move east
into the area...affecting each TAF site...tonight. Lots of
uncertainty on timing of the next round of storms...so kept VCTS
in TAFs as previously forecasted. Did add a TEMPO group at the end
as best first guess on when storms will on station. Winds will be
southerly through the period with gusty conditions during the day
today.
Auten
&&
.PREV DISCUSSION...
ISSUED 330 AM CDT Mon May 12 2014
SHORT TERM...Today through Wednesday night
Quiet conditions temporarily returned to central and southeast IL
early this morning as convection with MCS had shifted east of IL
into east central IN and Ohio, and a larger area of convection with
a couple MCSS was over WI/IA and eastern KS into far nw MO. Cold
front over western IA and eastern KS into central OK and west Texas
while warm front was over northern IL. Moist dewpoints in the
upper 60s over central and southern IL and mild temps 69-75F with
sse winds in warm sector.
Strong upper level trof over the Rockies with 557 dm 500 mb low
over western CO to eject surface 1002 mb low over east central KS
ne into the upper MS river valley by midnight tonight and swing a
cold front east across IL overnight. 00Z models are in fair
agreement with timing of this cold frontal passage. Isolated to
scattered thunderstorms to develop during today especially this
afternoon over the IL river valley as air mass destabilizes with
CAPES increasing to 1500-2500 J/kg. Best chances of convection
will be tonight with slight chance of severe storms nw of IL river
this evening. Best risk of severe supercells with possible
tornados form mid afternoon into mid evening will be over eastern IA
northern MO into far nw IL and sw WI where stronger wind shear
will be. Another very warm and humid day with highs in the mid 80s
with a few areas se of IL river even seeing upper 80s with enough
sunshine.
Cold front to pass east into Indiana early Tue morning and have
highest chances of convection over eastern IL Tue morning and
diminishing to the west. SPC has 5% risk of severe storms Tue from
Wabash river east so mostly over IN. Highs Tue range from mid 60s
from I-55 west to the low to mid 70s east of I-57 in eastern IL.
Looks like a lull in shower chances over central IL Tue night
though kept chances of showers over southern areas especially se
IL closer to frontal boundary stalling just se of IL. Leaned on
wetter ECMWF and NAM models with surface low ejecting ne Wed and
passing just se of IL while GFS appears too weak and far to the
east with its QPF fields. Have isolated thunderstorms Wed se of
I-70 while SPC keeps slight risk of severe storms se of IL Wed.
Showers to diminish from the west during Wed night with highest
chances near the IN border Wed evening. Cooler highs in the upper
50s and lower 60s Wed and these cooler readings to linger Thu.
LONG TERM...Thursday through Monday
Medium to long range models and their ensembles continues to
advertise large upper level trof over the MS river valley Thu
and upper level low lifting north of the Great Lakes this weekend
while trof shifts east into the eastern states. As core of coolest
850 mb air shifts ne of central IL during the weekend with upper
level low, expect temperatures to modify during this weekend into
early next week but generally still stay a below normal. Cool
nights in the low to mid 40s Thu night through Sat night.
Instability light rain showers possible Thu & Fri especially
during the afternoon and early evening with disturbances pivoting
thru the nearby upper level trof. Isolated light showers still
possible Sat sw of I-74 while dry conditions then prevail from Sat
night through Monday.
07
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
708 AM CDT MON MAY 12 2014
.SYNOPSIS...
ISSUED AT 321 AM CDT MON MAY 12 2014
LOW PRESSURE MOVING INTO WESTERN IA WILL LIFT NORTHEAST AS COLD
FRONT SWEEPS ACROSS THE STATE BY LATE TONIGHT. PATTERN WILL CHANGE
TO A MUCH COOLER REGIME AS CANADIAN HIGH PRESSURE DOMINATES
THROUGH THE REST OF THE WORK WEEK.
&&
.UPDATE...
ISSUED AT 704 AM CDT MON MAY 12 2014
UPDATED FORECAST FOR MINOR ADJUSTMENTS TO PRECIP TRENDS AND TEMP
TRENDS. ALSO FOR REMOVAL OF HEADLINES.
&&
.SHORT TERM /TODAY/...
ISSUED AT 321 AM CDT MON MAY 12 2014
TWO PROBLEMS TODAY ARE BOTH WITH CONVECTION THE EARLY MORNING
CONVECTION WILL BE AN ISSUE WITH THE POTENTIAL FOR LOCALLY HEAVY
RAINFALL MOVING INTO ALREADY SATURATED AREAS. THIS IS ASSOCIATED
WITH A WEAK WAVE IN THE FLOW THAT IS LIFTING NORTHEAST ACROSS THE
STATE. ADDITIONAL DEVELOPMENT IS LIKELY OVER THE SOUTHEAST HALF OF
THE STATE WITH THE COLD FRONT PROGRESSING EAST. THE HRRR HAS WHAT
SEEMS TO BE A REASONABLE HANDLE ON THIS. SEVERITY WILL DEPEND ON
HOW MUCH RECOVERY WE CAN ACHIEVE AFTER THE MORNING CONVECTION.
.LONG TERM /TONIGHT THROUGH SUNDAY/...
ISSUED AT 321 AM CDT MON MAY 12 2014
PRECIPITATION WILL MOVE OUT OF THE STATE BY 06Z AS THE PATTERN
CHANGES FROM A SOUTHWEST FLOW TO A NORTHWEST FLOW. CANADIAN HIGH
PRESSURE WILL DOMINATE THE WEEKS WEATHER WITH TEMPERATURES WELL
BELOW NORMAL. WILL POTENTIAL NEED TO CONSIDER SOME FROST WORDING
LATER IN THE WEEK, BUT CERTAINTY IS NOT THERE AT THIS TIME BECAUSE
OF THE POTENTIAL FOR SOME CLOUD COVER. IT WILL LIKELY TAKE UNTIL
THE WEEKEND BEFORE THE COOL HIGH PRESSURE MOVES OFF TO THE EAST.
WARMING AND AN INCREASED CHANCE FOR THUNDERSTORMS IS EXPECTED
LATER IN THE WEEKEND.
&&
.AVIATION...12/12Z
ISSUED AT 544 AM CDT MON MAY 12 2014
LOW PRESSURE OVER SERN NEBRASKA WILL MOVE NORTHEAST THROUGH
WESTERN IA AND INTO MINNESOTA BY THIS EVENING. TRAILING COLD
FRONT WILL MOVE EAST ACROSS THE TAF SITES LATER TODAY AND THIS
EVENING. AREA OF THUNDERSTORMS ARE EXPECTED ALONG AND AHEAD OF
THE COLD FRONT TODAY...WITH MVFR STRATUS SPREADING INTO THE AREA
BEHIND THE COLD FRONT. MVFR CIGS WILL HOLD THROUGH THE NIGHT.
OUTLOOK...HIGH PRESSURE WILL BUILD INTO THE AREA TUE AND WED AND
DOMINATE THE WEATHER THROUGH THE WORK WEEK. SEVERAL MINOR
DISTURBANCES WILL MOVE THROUGH...BUT CONDITIONS WILL REMAIN VFR.
&&
.HYDROLOGY...
ISSUED AT 704 AM CDT MON MAY 12 2014
THUNDERSTORMS CONTINUE TO LIVE NORTHEAST ACROSS THE STATE AHEAD OF
THE APPROACHING COLD FRONT. THE HEAVIER STORMS WILL MOVE OVER
AREAS THE DID NOT RECEIVE A LOT OF RAIN DURING THE PAST 24 HOURS.
THE RAIN IS EXPECTED TO END BY MID MORNING. ADDITIONAL SCATTERED
THUNDERSTORMS WILL DEVELOP THIS AFTERNOON...ESPECIALLY EAST OF
INTERSTATE 35. THEY ARE NOT EXPECTED TO PRODUCE FLASH FLOODING
HOWEVER.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...MS MAY 14
SYNOPSIS...MS MAY 14
SHORT TERM...MS MAY 14
LONG TERM...MS MAY 14
AVIATION...MS MAY 14
HYDROLOGY...MS MAY 14
AREA FORECAST DISCUSSION
NWS DES MOINES IA
547 AM CDT MON MAY 12 2014
.SYNOPSIS...
ISSUED AT 321 AM CDT MON MAY 12 2014
LOW PRESSURE MOVING INTO WESTERN IA WILL LIFT NORTHEAST AS COLD
FRONT SWEEPS ACROSS THE STATE BY LATE TONIGHT. PATTERN WILL CHANGE
TO A MUCH COOLER REGIME AS CANADIAN HIGH PRESSURE DOMINATES
THROUGH THE REST OF THE WORK WEEK.
&&
.SHORT TERM /TODAY/...
ISSUED AT 321 AM CDT MON MAY 12 2014
TWO PROBLEMS TODAY ARE BOTH WITH CONVECTION THE EARLY MORNING
CONVECTION WILL BE AN ISSUE WITH THE POTENTIAL FOR LOCALLY HEAVY
RAINFALL MOVING INTO ALREADY SATURATED AREAS. THIS IS ASSOCIATED
WITH A WEAK WAVE IN THE FLOW THAT IS LIFTING NORTHEAST ACROSS THE
STATE. ADDITIONAL DEVELOPMENT IS LIKELY OVER THE SOUTHEAST HALF OF
THE STATE WITH THE COLD FRONT PROGRESSING EAST. THE HRRR HAS WHAT
SEEMS TO BE A REASONABLE HANDLE ON THIS. SEVERITY WILL DEPEND ON
HOW MUCH RECOVERY WE CAN ACHIEVE AFTER THE MORNING CONVECTION.
.LONG TERM /TONIGHT THROUGH SUNDAY/...
ISSUED AT 321 AM CDT MON MAY 12 2014
PRECIPITATION WILL MOVE OUT OF THE STATE BY 06Z AS THE PATTERN
CHANGES FROM A SOUTHWEST FLOW TO A NORTHWEST FLOW. CANADIAN HIGH
PRESSURE WILL DOMINATE THE WEEKS WEATHER WITH TEMPERATURES WELL
BELOW NORMAL. WILL POTENTIAL NEED TO CONSIDER SOME FROST WORDING
LATER IN THE WEEK, BUT CERTAINTY IS NOT THERE AT THIS TIME BECAUSE
OF THE POTENTIAL FOR SOME CLOUD COVER. IT WILL LIKELY TAKE UNTIL
THE WEEKEND BEFORE THE COOL HIGH PRESSURE MOVES OFF TO THE EAST.
WARMING AND AN INCREASED CHANCE FOR THUNDERSTORMS IS EXPECTED
LATER IN THE WEEKEND.
&&
.AVIATION...12/12Z
ISSUED AT 544 AM CDT MON MAY 12 2014
LOW PRESSURE OVER SERN NEBRASKA WILL MOVE NORTHEAST THROUGH
WESTERN IA AND INTO MINNESOTA BY THIS EVENING. TRAILING COLD
FRONT WILL MOVE EAST ACROSS THE TAF SITES LATER TODAY AND THIS
EVENING. AREA OF THUNDERSTORMS ARE EXPECTED ALONG AND AHEAD OF
THE COLD FRONT TODAY...WITH MVFR STRATUS SPREADING INTO THE AREA
BEHIND THE COLD FRONT. MVFR CIGS WILL HOLD THROUGH THE NIGHT.
OUTLOOK...HIGH PRESSURE WILL BUILD INTO THE AREA TUE AND WED AND
DOMINATE THE WEATHER THROUGH THE WORK WEEK. SEVERAL MINOR
DISTURBANCES WILL MOVE THROUGH...BUT CONDITIONS WILL REMAIN VFR.
&&
.HYDROLOGY...
ISSUED AT 321 AM CDT MON MAY 12 2014
THEN ENVIRONMENT REMAINS FAVORABLE FOR HEAVY RAINFALL AT LEAST
THROUGH EARLY THIS MORNING WITH THE LOW PRESSURE AND COLD FRONT
CLOSE. DECENT DEVELOPMENT OVER WESTERN IOWA AND TO THE SOUTHWEST
OF THE STATE WILL MOVE NORTHEAST THROUGH THE STATE THIS MORNING.
MOST VULNERABLE AREAS WILL BE THE SOUTHWEST AND SOUTH CENTRAL
AREAS...AND SOME IN THE NORTHWEST...WHERE RAINFALL TOTALS HAVE
BEEN IN THE 2 TO 3 INCH RAIN LOCALLY WITH SOME HIGHER TOTALS.
ADDITIONAL THUNDERSTORM DEVELOPMENT LATER IN THE DAY IS LIKELY TO
BE EAST OF THESE AREAS AND TO NOW ANTICIPATE EXTENDING THE FLASH
FLOOD WATCH AT THIS TIME.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 7 AM CDT THIS MORNING FOR ADAIR-ADAMS-
AUDUBON-BLACK HAWK-BOONE-BREMER-BUTLER-CALHOUN-CARROLL-CASS-
CERRO GORDO-CRAWFORD-DALLAS-EMMET-FRANKLIN-GREENE-GRUNDY-GUTHRIE-
HAMILTON-HANCOCK-HARDIN-HUMBOLDT-KOSSUTH-MADISON-MARSHALL-PALO
ALTO-POCAHONTAS-POLK-RINGGOLD-SAC-STORY-TAMA-TAYLOR-UNION-
WEBSTER-WINNEBAGO-WORTH-WRIGHT.
&&
$$
SYNOPSIS...MS MAY 14
SHORT TERM...MS MAY 14
LONG TERM...MS MAY 14
AVIATION...MS MAY 14
HYDROLOGY...MS MAY 14
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
610 AM CDT Mon May 12 2014
...Updated aviation discussion...
.SHORT TERM...(Today and tonight)
ISSUED AT 200 AM CDT MON MAY 12 2014
A few high based showers will be possible across west central and
portions of southwest Kansas through late morning as the closed off
upper level low to our west opens up while moving east into the
Western High Plains today. Much colder air aloft surging southward
into the region will increase lapse rates aloft supporting the
potential for a few isolated showers. Otherwise, tranquil
conditions are likely Monday afternoon through Monday night as
drier air continues move down into the high plains of western
Kansas. Much cooler temperatures are on the way today as colder
air surges southward into western Kansas through the period. The
NAM/GFS show the H85 isotherm slipping southward nosing into west
central and the I-70 corridor with H85 temperatures near 5C closer
to the Oklahoma border. With low level stratus lingering through
at least mid day, look for highs struggling to reach the 50s(F)
across west central and central Kansas near the I-70 corridor with
the upper 50s(F) to near 60F in south central Kansas.
.LONG TERM...(Tuesday through Sunday)
ISSUED AT 246 AM CDT MON MAY 12 2014
An upper level trough will slowly move east across western Kansas
late Tuesday and Wednesday. Mid level moisture under the cool
upper low appears to increase late Wednesday as 700mb warm air
advection develops ahead of a north to south oriented upper level
jet located on the western side of this upper level trough.
Precipitation chances still appear small mid week, however
increasing clouds are expected which may limit how warm
temperatures will be mid week. At this time will lean towards the
latest guidance for highs on Wednesday with temperatures mainly in
the mid to upper 60s. Lows Tuesday night may also be impacted and
given the potential for increasing clouds from the west towards
daybreak will favor lows several degrees warmer than what the
latest guidance suggests across far western Kansas.
On Thursday a cold front will move into northern Kansas as an
upper level disturbance drops south of of Canada and crosses the
northern Plains. Timing issues exist on when this boundary will
move into western Kansas. Given these timing issues with the
frontal passage will stay close to the latest CRExtendFcst_Init on
Temperatures Thursday and Friday. In addition to some cooler air
returning to portions of northern Kansas behind the cold front
late week there will also be improving chances for precipitation,
especially across northern central Kansas.
&&
.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
ISSUED AT 608 AM CDT MON MAY 12 2014
Model soundings indicating the depth of the low level moisture
will decrease today as a surface ridge axis begins to build into
western Kansas. Model soundings suggesting ceilings will improve
to MVFR by 14z and VFR after 18z. HRRR also suggesting this trend
as well. Gusty northwest winds of 20 to near 25 knots can be
expected through at 00z Tuesday based on the mean mixed layer
winds. After sunset winds will decrease to around 10 knots.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 55 35 63 36 / 10 0 0 0
GCK 52 34 61 34 / 20 0 0 0
EHA 53 34 58 36 / 10 0 10 0
LBL 55 34 64 33 / 10 0 10 0
HYS 52 35 63 36 / 30 0 0 0
P28 62 40 65 39 / 20 0 10 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...JJohnson
LONG TERM...Burgert
AVIATION...Burgert
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
740 AM EDT MON MAY 12 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 515 AM EDT MON MAY 12 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A BUILDING RIDGE ALONG THE
W COAST OF NAMERICA WITH AMPLIFIED DOWNSTREAM TROF OVER THE ROCKIES.
MAIN PIECE OF ENERGY IS IN THE BASE OF THE TROF OVER COLORADO.
WAA/ISENTROPIC ASCENT DOWNSTREAM INTO THE UPPER LAKES IS SUPPORTING
A LARGE AREA OF SHRA/TSRA LIFTING NE ACROSS MN/WI EARLY THIS
MORNING. SHORTWAVE MOVING NE INTO WRN WI IS FURTHER AIDING THE PCPN.
INSTABILITY HAS BEEN SLOW TO ADVANCE N PER SPC MESOANALYIS...SO
WHILE SHRA ARE ADVANCING STEADILY N AND E...TSRA ARE LAGGING FARTHER
AND FARTHER S WITHIN THE OVERALL SHRA AREA.
HIGH RES MODEL GUIDANCE...PARTICULARLY THE HIGH RES RAPID REFRESH...
HAS A DECENT HANDLE ON APPROACHING SHRA. UTILIZED RADAR TRENDS AND
HIGH RES GUIDANCE TO SWING A PERIOD OF CATEGORICAL POPS ACROSS THE
FCST AREA THIS MORNING. FORTUNATELY...PCPN AMOUNTS DON`T LOOK TO BE
EXCESSIVE AS MAIN AREA OF TSRA WILL PASS BY TO THE S. STILL...
EXPECT ROUGHLY 0.5 TO 0.75 INCHES WHICH WILL GIVE AREA
RIVERS/STREAMS A BOOST IN FLOW. AS SUPPORTING SHORTWAVE MOVES NE OF
THE AREA...MUCH OF THE AFTN MAY TURN DRY IN ITS WAKE. POPS WERE
LOWERED INTO THE CHC/SCT CATEGORY...BUT BELIEVE MANY AREAS WILL
PROBABLY SEE A GOOD PERIOD OF DRY WEATHER THIS AFTN. WITH PCPN AT A
MINIMUM DURING THE AFTN...TEMPS WILL HAVE A CHANCE TO RESPOND...AT
LEAST IN AREAS WHERE GENERAL EASTERLY FLOW IS NOT OFF THE GREAT
LAKES. BUMPED TEMPS UP INTO THE UPPER 50S/LWR 60S ACROSS MUCH OF THE
INTERIOR. HIGH RES RAPID REFRESH SHOWS TEMPS RISING TO AROUND 70F
OVER THE INTERIOR W THIS AFTN...CERTAINLY POSSIBLE IF CLOUDS THIN
OUT SUFFICIENTLY.
AS SFC LOW PRES LIFTS FROM WRN WI ACROSS WRN LAKE SUPERIOR
TONIGHT...WARM FRONT WILL ATTEMPT TO MOVE INTO UPPER MI. AT THIS
POINT...IT APPEARS THE WARM FRONT MAY JUST SLIP INTO FAR SRN UPPER
MI. ADDITIONAL SHRA/TSRA WILL LIKELY DEVELOP AS SFC LOW/WARM FRONT
LIFT N...THOUGH PCPN COVERAGE PROBABLY WON`T BE AS WIDESPREAD AS
WHAT WILL OCCUR THIS MORNING. WITH ELEVATED CAPE UP AROUND 1000J/KG
AND DEEP LAYER SHEAR AROUND 30KT OR SO...STORMS WILL HAVE THE
POTENTIAL TO BECOME ORGANIZED WITH ISOLD SVR POSSIBLE...MAINLY OVER
FAR SCNTRL UPPER MI...CLOSER TO WARM FRONT. MAIN THREAT SHOULD BE
HAIL...BUT WITH PRECIPITABLE WATER 200-250PCT OF NORMAL...HVY
RAINFALL WILL BE A GOOD BET WITH ANY TSRA.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 504 AM EDT MON MAY 12 2014
DEEP TROUGH FOR MAY AND REALLY ANYTIME OF THE YEAR STRETCHES FROM
CENTRAL CANADA TO THE SOUTHERN PLAINS ON TUESDAY. SFC LOW CURRENTLY
OVER THE CENTRAL PLAINS SHOULD BE JUST NORTHWEST OF LK SUPERIOR
DAYBREAK ON TUESDAY. OCCLUDED FRONT WILL BE SLICING ACROSS CWA
THROUGH MID MORNING...EXITING EASTERN CWA BY EARLY AFTN. SHOULD BE AT
LEAST SCT SHRA/TSRA EXPECTED ALONG AND AHEAD OF FRONT AS HIGHER
1000-850MB THETA-E POOLS ALONG THE BOUNDARY. SHARP DRYING ENDS ANY
RAIN QUICKLY OVER WEST HALF IN THE MORNING...BUT MAY SEE ISOLD
SHRA/TSRA OVER FAR SOUTHEAST CWA AS WEAK LOW-LEVEL CONVERGENCE
LINGERS AND AS ANOTHER WEAKER SHORTWAVE/Q-VECTOR CONVERGENCE AT
H85-H5 LIFTS OVER FAR EAST CWA. ANY STORMS AHAEAD OF FRONT IN THE
MORNING SHOULD BE WEAK AS 1-6KM MUCAPE AND MLCAPE BOTH DIMINISH
STEADILY COMPARED TO THE OVERNIGHT HOURS. TEMPS WILL RISE INTO THE
60S OVER THE CNTRL WHERE WEST WINDS DOWNSLOPE...IMT-ESC-MNM...BUT
WILL STAY IN THE 50S OVER THE WESTERN/NORTHWEST CWA WITH GRADIENT
WINDS OFF LK SUPERIOR. THOSE WINDS COULD BE QUITE GUSTY...ESPECIALLY
OVER THE MORE EXPOSED KEWEENAW...WHERE NAM/GFS SOUNDINGS INDICATE
MIXED LAYER BUILDING TO H85-H8 WITH WINDS OVER 35 KTS IN THE MIXED
LAYER.
QUIET WEATHER TUESDAY NIGHT AND WEDNESDAY AS DEEP SFC LOW SLOWLY
LIFTS TO JAMES BAY/HUDSON BAY. GRADIENT WEST FLOW STAYS OVER UPR
MICHIGAN...BUT WILL LIGHTEN ENOUGH ON WEDNESDAY TO RESULT IN LAKE
BREEZES. SLIM CHANCE THAT RESULTING LOW-LEVEL CONVERGENCE ADDED TO
WEAK H7-H5 FORCING FM SHORTWAVE DROPPING ACROSS ON PERIFERY OF DEEP
TROUGH ALOFT COULD TRIGGER A FEW SHOWERS/SPRINKLES INTERIOR CENTRAL.
DEEP MIXING TO H8 WILL LIMIT POTENTIAL THOUGH AS LOW-LEVEL RH VALUES
DROP OFF BLO 40 PCT. MAX TEMPS SHOULD PUSH INTO THE 50S INLAND AND
FALL BACK INTO THE 40S NEAR LK SUPERIOR ONCE LAKE BREEZE DEVELOPS.
THE FORECAST FOR THURSDAY INTO FRIDAY REMAINS UNCERTAIN. AT THE
LEAST...TEMPS WILL BE BLO NORMAL FOR MOST CWA...PERHAPS BY MORE
THAN 10-15F OVER THE NORTHERN CWA. ECMWF STILL SUPPORTS POTENTIAL
FOR ACCUMULATING SNOW...NOW MAINLY DELAYED UNTIL THURSDAY NIGHT
THROUGH FRIDAY AND POSSIBLY INTO FRIDAY NIGHT. LATEST UKMET ALSO
IN LINE WITH THE ECMWF IDEA. MEANWHILE...GFS AND GEM-NH STAY WITH
PROGRESSIVE IDEA INDICATING STRONG SHORTWAVE ROUNDING BASE OF DEEP
TROUGH STAYS SEPARATE ENOUGH FROM TROUGH FROM HUDSON BAY TO THE
NORTHERN PLAINS TO LIMIT PHASING. IF GFS THEME IDEA IS RIGHT...WOULD
SEE SETUP WITH MORE DIURNALLY DRIVEN MAINLY RAIN SHOWERS DUE TO
INSTABILITY ALOFT BENEATH THE TROUGH AXIS. IF THE ECMWF AND UKMET
ARE ON THE RIGHT TRACK...THEY INDICATE ENOUGH PHASING BTWN THE LARGE
SCALE TROUGHS TO DRAG A SFC LOW PRESSURE SYSTEM NORTHWARD OVER THE
CNTRL GREAT LAKES INTO TOWARD THE UPPER GREAT LAKES THURSDAY INTO
FRIDAY. WITH THAT SCNEARIO...WIDESPREAD RAIN AND SNOW THURSDAY
EVENING WOULD CHANGE TO SNOW THURSDAY NIGHT INTO MUCH OF FRIDAY AND
NORTHERLY FLOW WOULD ONLY BOOST THE SNOW OVER HIGHER TERRAIN AREAS
NEAR LK SUPERIOR. SNOW COULD BE PRETTY WIDESRPEAD AS PYTPE WITH H85
TEMPS DROPPING BLO -5C AND SINCE 1000-850MB THICKNESSES FALL BLO
1300M. PHASING SYSTEMS ARE ALWAYS TOUGH TO FORECAST. ADD TO THAT
FACT THAT WE ARE PUSHING INTO MIDDLE OF MAY AND IT MAKES IT REALLY
TOUGH TO SAY IF UKMET AND ECMWF SOLUTION WILL WORK OUT AS FORECAST.
SINCE ECMWF ENSEMBLE MEAN WOULD ALSO SUPPORT SIMILAR IDEA AND SOME
CANADIAN ENSEMBLES HAVE SHOWN THIS RECENTLY IT DOES SUGGEST THE IDEA
AT LEAST HAS SOME MERIT COMPARED TO JUST ONE ROUGE OPERATIONAL MODEL
RUN SHOWING A BIG STORM IN THE FAR REACHES OF THE EXTENDED.
ONCE THE SYSTEM OR JUST THE OPEN TROUGH MOVES BY...WEEKEND LOOKS
DRIER WITH GRADUAL WARMING TREND. DID NOT STRAY FROM CONSENSUS LOW
CHANCE POPS FOR NEXT WEEKEND ATTM.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 738 AM EDT MON MAY 12 2014
CHALLENGING FCST SHAPING OVER THE NEXT 24HRS AS LOW PRES AND WARM
FRONT LIFT INTO THE UPPER GREAT LAKES. ONGOING SHRA WILL WORK TO
MOISTEN THE LOW-LEVELS...AND EXPECT KIWD/KCMX/KSAW TO FALL TO MVFR
THIS MORNING WITH SOME PERIODS OF IFR POSSIBLE. AS DISTURBANCE
GENERATING THE MORNING SHRA EXITS TO THE NE...THERE MAY NOT BE ANY
SHRA AT THE TERMINALS DURING THE AFTN HRS. WITH E UPSLOPE FLOW OFF
CHILLY LAKE SUPERIOR...KCMX WILL PROBABLY SEE LIFR CONDITIONS
DEVELOP. MAINTAINED MVFR CONDITIONS AT KIWD/KSAW. WITH MORE OF A
DOWNSLOPE COMPONENT AT KIWD...EXPECT HIGHER CIGS THERE...AND ITS
POSSIBLE THERE COULD BE SOME PERIODS OF VFR. ON THE OTHER
HAND...UPSLOPE WIND AT KSAW COULD LEAD TO SOME PERIODS OF IFR. SHRA
WILL REDEVELOP TONIGHT WITH LIFR/IFR CONDITIONS PREVAILING. COULD BE
SOME TSRA AS WELL...PARTICULARLY AROUND KSAW...BUT LIMITED CONFIDENCE
IN TIMING/COVERAGE OF TSRA PRECLUDES A MENTION IN THIS FCST.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 504 AM EDT MON MAY 12 2014
EXPECT PERIOD OF STRONGER WINDS OVER LAKE SUPERIOR. APPROACHING LOW
PRESSURE SYSTEM RESULTS IN NORTHEAST WINDS INCREASING TO GALES BY
AFTN OVER WEST HALF OF LK SUPERIOR. WINDS TO 30 KTS OVER REST OF LK
SUPERIOR. STRONG WINDS DIMINISH BRIEFLY LATER THIS EVENING AND
OVERNIGHT TONIGHT AS THE LOW SLIDES ACROSS WESTERN LK SUPERIOR. ONCE
THE LOW MOVES NORTH OF THE LAKE ON TUESDAY MORNING...STRONG WEST
WINDS KICK UP. EXPECT THESE STRONG WESTERLIES...PROBABLY REACHING
GALES ON TUESDAY OVER NCNTRL LK SUPERIOR...TO SLOWLY FADE BLO 25 KTS
BY WEDNESDAY MORNING. WINDS REST OF THE WEEK WILL MAINLY BE BLO 20
KTS. HOWEVER...A LOW PRESSURE SYSTEM COULD IMPACT THE REGION LATE
THIS WEEK WITH WINDS OVER 25 KTS THURSDAY INTO FRIDAY. UNCERTAINTY
IS HIGH WITH THAT SYSTEM THOUGH...SO CURRENT FORECAST WILL ONLY CALL
FOR NORTHWEST TO 20 KTS AT THIS TIME.
&&
.HYDROLOGY...
ISSUED AT 504 AM EDT MON MAY 12 2014
WIDESRPEAD MODERATE TO HEAVY RAIN WILL AFFECT ALL OF UPR MICHIGAN
THROUGH EARLY THIS AFTN BEFORE DIMINISHING...THEN THERE MAY BE
ANOTHER PERIOD OF MODERATE RAINFALL TONIGHT. RAINFALL AMOUNTS MAY
EXCEED ONE INCH TODAY OVER PORTIONS OF WESTERN UPR MICHIGAN. RAIN
CHANCES DIMINISH FROM WEST TO EAST ON TUESDAY AS A FRONTAL BOUNDARY
EXITS THE REGION. RAINFALL WILL ONLY ADD TO THE ONGOING SNOWMELT AND
ALREADY HIGH FLOWS ON AREA RIVERS AND STREAMS. THE PRIMARY CHANGE TO
ONGOING HEADLINES WAS LAST EVENING...WHEN BASED ON EXPECTED
RAINFALL...WHICH LOOKS LIKE IT IS WORKING OUT...ADVISORIES WERE
UPGRADED TO WARNINGS FOR THE MICHIGAMME RIVER NEAR REPUBLIC AND
WITCH LAKE. THE WARNING FOR THE STURGEON RIVER NEAR CHASSELL AND THE
ADVISORY FOR THE STURGEON RIVER NEAR ALSTON CONTINUE...AS DOES THE
ADVISORY FOR THE MICHIGAMME RIVER DOWNSTREAM OF WAY DAM...TO THE
EAST OF CRYSTAL FALLS IN IRON COUNTY.
GIVEN THE RAINFALL THAT WILL AFFECT THE AREA THE NEXT 24-36
HOURS...RIVER LEVELS WILL KEEP RISING AND ADJUSTMENTS WILL LIKELY BE
NEEDED BASED ON LATEST TRENDS. ALL THIS WATER DUE TO THE SNOWMELT
AND THE RAINFALL WILL TAKE A WHILE TO WORK THROUGH THE RIVERS...SO
IT IS QUITE LIKELY THAT HIGHER RIVER FLOWS AND THE ASSOCIATED
ADVISORIES AND WARNINGS ON AREA RIVERS WILL CONTINUE THROUGH LATE
THIS WEEK...IF NOT INTO NEXT WEEKEND. THOSE LIVING NEAR
RIVERS...CREEKS...AND STREAMS SHOULD CONTINUE TO MONITOR THE LATEST
RIVER LEVELS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL MIDNIGHT EDT /11 PM CDT/ TONIGHT FOR LSZ162.
GALE WARNING UNTIL 11 PM EDT THIS EVENING FOR LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...ROLFSON
MARINE...JLA
HYDROLOGY...JLA
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
706 AM CDT MON MAY 12 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 334 AM CDT MON MAY 12 2014
SHOWERS ARE PUSHING EAST OF OUR WEST CENTRAL WI COUNTIES EARLY THIS
MORNING WITH JUST A FEW SCATTERED SHOWERS ACROSS THE MN COUNTIES.
RAINFALL AMOUNTS OVERNIGHT FROM 1 TO 1.50 INCHES HAVE BEEN COMMON
ACROSS SOUTHERN MN AND ADJOINING AREAS OF WEST CENTRAL WI. RAINFALL
AMOUNTS DROP OFF TO AROUND A HALF INCH FROM WEST CENTRAL MN TO NW
WI.
THE DAY AHEAD WILL FEATURE A LOW PRESSURE SYSTEM MOVING SLOWLY
NORTHEAST FROM IA TO THE SOUTHERN TWIN CITIES METRO BY EARLY THIS
AFTERNOON. THE LOW SHOULD REACH FAR NORTHERN WI BY LATE THIS
EVENING. THERE IS PLENTY OF POTENTIAL FOR SEVERE STORMS TO DEVELOP
THIS AFTERNOON/EVENING IN THE VICINITY OF THE SURFACE LOW AND WARM
FRONT EXTENDING TO THE EAST. LIMITING FACTORS WILL BE THE EXTENSIVE
CLOUDINESS THAT WILL HOLD DOWN ON THE DESTABILIZATION. RAP DATA
SHOWS A WARM POCKET MOVING NORTHEAST FROM IA THIS MORNING BETWEEN
650-700MB. THIS IS SQUARELY OVER WEST CENTRAL WI EARLY THIS
AFTERNOON. LOW LEVEL LAPSE RATES SUFFER AS WELL AS SURFACE BASED
CAPE. HOWEVER...BY LATE IN THE AFTERNOON...SOUNDING DATA FOR KEAU
SHOWS THE POTENTIAL TO WARM ENOUGH TO GET PAST THE MID LEVEL WARM
POCKET. SURFACE BASED CAPE REACHES A LITTLE MORE THAN 2000 J/KG.
SHEAR IS ADEQUATE WITH 0-1KM REACHING 25 KNOTS WITH 0-6KM BETTER
THAN 45 KNOTS. 500MB WINDS ARE VERY IMPRESSIVE WITH A CORE OF 60-70
KNOT WINDS PROGGED ACROSS THE TWIN CITIES AND WEST CENTRAL WI THIS
AFTERNOON. OUR MPXWRF...THE HOPWRF AND THE SPCWRF START BREWING
TROUBLE ALONG OUR MN/WI BORDER AREA BY 21Z WITH THE HINT OF A FEW
SUPERCELLS ACROSS WEST CENTRAL WI INTO THE EARLY EVENING. GIVEN THE
LOW LCLS...SHEAR AND WARM FRONT...A TORNADO OR TWO CAN NOT BE RULED
OUT. IN FACT...THERE HAVE BEEN TORNADOES THE PAST TWO DAYS NEAR THE
SURFACE LOW AND WARM FRONT.
NORTHWEST WINDS WILL STRENGTHEN ACROSS THE FA TONIGHT IN THE WAKE OF
THE LOW PRESSURE SYSTEM. THIS WILL USHER IN MUCH COOLER AIR THAT
WILL BE WITH US FOR THE BALANCE OF THE WEEK AS A LARGE TROUGH ALOFT
DOMINATES ACROSS THE MISSISSIPPI VALLEY REGION.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 334 AM CDT MON MAY 12 2014
THE THEME FOR THE LONG TERM PERIOD IS DRY WEATHER FOR THE UPPER
MIDWEST. ALTHOUGH...IT WILL ALSO BE A COOL PERIOD MAINLY TUESDAY
THROUGH FRIDAY AS TEMPERATURES WILL RUN 10 TO 15 DEGREES BELOW
NORMAL.
PICKING UP TUESDAY MORNING...THE UPPER LEVEL TROUGH AXIS WILL BE
IN THE VICINITY OF THE WESTERN MN/EASTERN DAKOTAS BORDER. THE
SURFACE LOW WILL HAVE LIFTED UP INTO ONTARIO NORTH OF LAKE
SUPERIOR. THE NAM REMAINS STUBBORN IN HAVING THE MOVEMENT OF THE
LOW A TAD SLOWER/GIVEN ITS DEEPER SOLUTION WITH THE TROUGH MONDAY
NIGHT/...BUT IT HAS STARTED TO MOVE TOWARD THE GFS/EC SOLUTIONS.
PREFERRED A EC/GFS BLEND THAT HAS THE LOW QUICKLY MOVING NORTH.
THE UPPER TROUGH AND MOISTURE ON THE BACK SIDE OF THE LOW
WARRANTED THE MENTION OF POPS ACROSS THE NORTHERN PART OF THE
FA...BUT ANY PRECIPITATION WILL BE VERY LIGHT. WITH THE UPPER
TROUGH OVERHEAD...TEMPERATURES WILL BE HELD IN THE 50S DURING THE
DAY...AND WITH THE DEPARTING LOW NORTHWEST WINDS WILL BE BLUSTERY
AND MAKE FOR A COOL DAY. WINDS SHOULD SLACKEN AND SKY COVER BEGIN
TO BREAK UP TUESDAY EVENING. 850H TEMPS WILL FALL BELOW ZERO
OVERNIGHT AND GIVEN WEAKENING WINDS AND AND DIMINISHING SKY COVER
OVERNIGHT...TEMPERATURES BY EARLY WEDNESDAY MORNING WILL BE IN THE
30S ACROSS THE FA. LITTLE CHANGE IS EXPECTED WEDNESDAY AS THE
AMPLIFIED UPPER TROUGH AND CORE OF THE COOL AIR REMAINS OVERHEAD.
MEANWHILE...BOTH THE EAST COAST AND WEST COAST WILL HAVE HIGHLY
AMPLIFIED RIDGING AND WARM TEMPERATURES. SLIGHT CHANCE POPS DO
SHOW UP AGAIN WEDNESDAY AFTERNOON ACROSS THE WEST AS ADDITIONAL
MOISTURE ALOFT ROTATES SOUTH ON THE BACK SIDE OF THE UPPER TROUGH.
WOULD NOT BE SURPRISED IF LOW LEVEL DRY AIR PREVENTS ANYTHING FROM
REACHING THE GROUND. WEDNESDAY NIGHT WILL BE COLDER AS 850H TEMPS
DROP TO -2C TO -6C GENERALLY ACROSS THE FA. WIDESPREAD 30S ARE
EXPECTED WITH SOME SPOTS HITTING THE FREEZING MARK.
THE AMPLIFIED TROUGH WILL PUSH SLIGHTLY EAST AND BECOME A CLOSED
UPPER LOW OVER WISCONSIN THURSDAY NIGHT INTO FRIDAY SO
CYCLONICALLY CURVED FLOW MAY AGAIN PRODUCE VERY LIGHT PRECIP
THURSDAY AFTERNOON. THE POPS ASSOCIATED WITH THIS TROUGH DURING
THE MIDWEEK MAY BE OVERDONE BY THE LARGE SCALE SYNOPTIC
MODELS...HOWEVER...SO WHILE THERE ARE SOME POPS IN THE FORECAST
FOR THE MIDWEEK TIME FRAME...TOTAL AMOUNTS WILL BE UNDER A TENTH OF
AN INCH...AND WILL LIKELY BE ZERO FOR PARTS OF THE AREA.
WE`LL SEE THE CORE OF THE COOL AIR ALOFT PUSH EAST AT THE START OF
THE WEEKEND AS THE WESTERN CONUS RIDGE STARTS PUSHING INTO THE
CENTER OF THE COUNTRY BY SUNDAY. BESIDES A COOL START...THE
WEEKEND LOOKS DRY...PARTLY CLOUDY...AND WARMER THAN THE COLD MIDWEEK
AHEAD. BEYOND THE WEEKEND...THE RIDGE AXIS WILL PUSH OVER OUR AREA
EARLY NEXT WEEK AND TEMPERATURES WILL CONTINUE TO WARM.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 706 AM CDT MON MAY 12 2014
SURFACE LOW PRESSURE OVER FAR SOUTH CENTRAL MN WILL BE MOVING
SLOWLY NORTHEAST TODAY...REACHING THE TWIN CITIES BY EARLY THIS
AFTERNOON AND NORTHERN WI BY LATE THIS EVENING. IFR CEILINGS AND
MVFR VSBYS IN -RA/DZ/BR ARE WIDESPREAD ON THE COLD SIDE OF THE LOW
(KRWF/KSTC/KAXN). THESE SITES SHOULD STAY THIS WAY THROUGH THE DAY
WITH ONLY A LITTLE IMPROVEMENT OVERNIGHT. CONFIDENCE IS LOWER FOR
KMSP...KRNH AND KEAU WHERE MAINLY VFR CEILINGS EXISTS.
HOWEVER...DUE TO THE HIGHS DEW POINTS AND NEAR SATURATION IN THE
LOW LEVELS...MVFR OR LOWER CIGS SHOULD DEVELOP THIS MORNING AND
PERSIST THROUGH THE AFTERNOON AND THEN LOWER TO IFR TONIGHT ON THE
BACKSIDE OF THE LOW. SOME SHOWERS WILL MOVE THROUGH THIS MORNING
WITH THE THREAT FOR THUNDERSTORMS THIS AFTERNOON AND EARLY
EVENING. CONFIDENCE IS HIGHEST FOR THUNDER AT KEAU DURING THE LATE
AFTERNOON HOURS. SOUTHEAST WINDS AHEAD OF THE LOW ON THE WARM SIDE
WITH NORTH TO NORTHWEST WINDS 10-15 KNOTS ON THE COLD SIDE.
KMSP...LOW CONFIDENCE FORECAST ON MVFR CEILINGS THIS MORNING.
ERRED ON THE LOW SIDE VERSUS VFR BEING OBSERVED FROM THE AIRFIELD
ON SOUTH AND EAST. FIGURING A LITTLE HEATING THIS MORNING WITH THE
SATURATED CONDITIONS WILL RESULT IN LOW CEILINGS DEVELOPING
QUICKLY. CERTAINLY THIS AFTERNOON AS WE TRANSITION TO THE BACKSIDE
OF THE APPROACHING LOW PRESSURE SYSTEM CEILINGS WILL DROP TO IFR
AND STAY THERE THROUGH MUCH OF TONIGHT. SHOWER/TSRA CHANCES ARE
BEST TO THE EAST AND SOUTH OF THE AIRFIELD TODAY WITH -RA/DZ MORE
LIKELY LATER THIS AFTERNOON AND TONIGHT. WINDS HAVE DIMINISHED
SINCE TAF ISSUANCE WITH LIGHT WINDS FOR THE NEXT FEW HOURS. THE
WINDS SHOULD PICK UP LATER IN THE MORNING FROM THE NE AND THEN
BECOME NW THIS AFTERNOON.
/OUTLOOK FOR KMSP/
TUE...MVFR LIKELY. SLGT CHC -SHRA. WINDS W-NW 15-20 KTS.
WED...MVFR POSSIBLE. SLGT CHC -SHRA. WINDS W-NW 10-15 KTS.
THU...MVFR POSSIBLE. SLGT CHC -SHRA. WINDS NW 10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...RAH
LONG TERM...SPD
AVIATION...RAH
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
650 AM CDT Mon May 12 2014
.SHORT TERM: (Today and Tonight)
Issued at 330 AM CDT Mon May 12 2014
Main forecast issues for today are the probability of thunderstorms
and any severe potental, as well as just how warm it may get.
Current thinking is there should be a gradual upswing in convection
as the day progresses, primarily during the later half of the
afternoon. It appears that northeast Missouri will be the area we
will have to watch most closely through mid morning. Two things to
key an eye on - an outflow boundary pushing southeastward across
eastern Iowa as a focus for additional thunderstorms, and also a
cluster of thunderstorms across eastern Kansas just southwest of
Kansas City and if they will hold together as they move northeastward.
Otherwise I think that there will be a general decrease in the
convective cloud debris during the morning, which given the mild
early morning temperatures should allow for a quick warm-up by
early afternoon. The convection allowing models and more
specifically the HRRR is suggesting that by mid morning, isolated
showers or thunderstorms could develop just about anywhere within
the CWA, but most favored across southeast Missouri and southern
Illinois. The main action still looks like the later half of the
afternoon. The warm sector air mass ahead of the cold front will
become quite unstable by mid-late afternoon with SBCAPE in excess
of 2000 J/KG and little CIN. Expecting numerous thunderstorms to
develop across western Missouri into central and northeast
Missouri. Deep layer shear of 20-30 kts and the anticipated CAPE
would support a few severe storms capable of large hail and
damaging winds from the afternoon into about mid-evening. The
front moves through all but the far eastern sections of the CWA
tonight accompanied by widespread showers and thunderstorms and
ushering much cooler air into the region in its wake. It also
appears that there will be an increasing amount of post-frontal
showers overnight immediately in the cool air in response to large
scale forcing.
Glass
.LONG TERM: (Tuesday through Sunday)
Issued at 330 AM CDT Mon May 12 2014
This marks the beginning of a cooler than normal period with a
slow-moving and deep upper trof dominating the region through the
week. The front will quickly exit the remainder of the CWA early
Tuesday morning with post-frontal showers impacting eastern
Missouri and southwest Illinois in the morning and exiting by
early-mid afternoon. Highs on Tuesday will be around 20 degrees
cooler than today. A strong short-wave and possibly upper low will
then migrate through the base of the deep trof from the southern
Plains and into the mid MS valley Tuesday night-Wednesday night.
More reminiscent of Fall or early Spring, large scale ascent with this
system should produce a large area of showers or rain spreading
into the area late Tuesday night into Wednesday. Its northward
extent and longevity is all dependent on the strength of the
system, and NAM featuring a closed low and large deformation zone, has
the greatest northward push and keeps precipitation well into
Wednesday night. Regardless the precipitation and accompanying
overcast low clouds will keep temperatures well below average on
Wednesday. We could continue to see a periodic shower threat
through the end of the week as we get into deeper cyclonic flow on
the backside of the slow-moving deep upper trof. Temperatures will
remain below average into at least Friday.
Glass
&&
.AVIATION: (For the 12z TAFs through 12z Tuesday Morning)
Issued at 640 AM CDT Mon May 12 2014
Mvfr strato cu deck advecting northward in warm sector and will
remain over region through mid morning before scattering out.
Otherwise, main issue is the chance for showers and thunderstorms
as cold front moves through region late this afternoon and
tonight. Activity will be scattered ahead of boundary so added
vcnty ts mention after 15z with tempo of thunderstorms later this
afternoon, mainly after 21z. Once front moves through will still
see some lingering showers through rest of forecast period. As for
winds, to remain from the south and pickup with gusts to near
25kts at times today. Then veer to the west as front moves through
and become northwesterly later tonight.
Specifics for KSTL:
Mvfr strato cu deck advecting northward in warm sector and will
remain over region through mid morning before scattering out.
Otherwise, main issue is the chance for showers and thunderstorms
as cold front moves through region late this afternoon and
tonight. Thunderstorms to develop and move in later this
afternoon, mainly after 00z Tuesday. Once front moves through will still
see some lingering showers through rest of forecast period. As for
winds, to remain from the south and pickup with gusts to near
25kts at times today. Then veer to the west by 04z Tuesday as
front moves through and become northwesterly after 09z Tuesday.
Byrd
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1005 AM CDT MON MAY 12 2014
.UPDATE...
ISSUED AT 1005 AM CDT MON MAY 12 2014
MADE SOME SLIGHT ADJUSTMENTS TO BUMP UP SKY COVER A LITTLE IN THE
WEST THROUGH THIS MORNING. ALSO ADJUSTED PRECIPITATION BASED ON
LATEST RADAR AND 12Z HRRR GUIDANCE. OTHERWISE NO SIGNIFICANT
CHANGES TO THE GOING FORECAST.
UPDATE ISSUED AT 639 AM CDT MON MAY 12 2014
NO MAJOR UPDATES ARE REQUIRED TO THE ONGOING FORECAST. THE CURRENT
WIND ADVISORY STILL LOOKS GOOD FOR TODAY. ONLY MODIFIED THE HOURLY
SENSIBLE WEATHER GRIDS BASED ON CURRENT OBS/TRENDS. THE UPDATED
PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 353 AM CDT MON MAY 12 2014
MAIN FORECAST ISSUE IN THE SHORT TERM PERIOD WILL BE PRECIPITATION
CHANCES OVER THE EASTERN THIRD OF THE FORECAST AREA TODAY...AND
WINDS TODAY.
CURRENTLY...FRONTAL BOUNDARY EXTENDED FROM LAKE WINNIPEG SOUTHEAST
ACROSS MINNESOTA SOUTH INTO IOWA AND SOUTHWESTWARD TO KANSAS AND
OKLAHOMA. HIGH PRESSURE EXTENDED ALONG THE FRONT RANGE OF THE
ROCKIES. WIDESPREAD LOWER CLOUD COVER ACROSS EASTERN PORTIONS OF
CENTRAL NORTH DAKOTA...WITH HIGHER CLOUDS TO THE WEST. AT UPPER
LEVELS...A LARGE LONGWAVE TROUGH EXTENDED FROM NORTH CENTRAL CANADA
SOUTHWARD ACROSS THE DAKOTAS TO THE 4-CORNERS AREA.
MODELS ARE IN GOOD AGREEMENT KEEPING AN AREA OF SHOWERS MAINLY FROM
SOUTH CENTRAL NORTH DAKOTA EAST OF THE MISSOURI RIVER TO THE JAMES
AND DEVILS LAKE BASINS...MAINLY SOUTH AND EAST OF A LINE FROM LINTON
TO HARVEY AND CARRINGTON. THERE MAY BE A RAIN/SNOW MIX ON THE FAR
WESTERN EDGE OF THE PRECIPITATION - BUT WOULD BE VERY LIGHT.
TEMPERATURES WEST OF THE PRECIPITATION AREA WERE IN THE LOWER
30S...WITH UPPER 30S TO 40 WHERE SCATTERED SHOWERS WERE OCCURRING.
THE UPPER LEVEL TROUGH IS PROGGED TO MOVE EASTWARD SLOWLY TODAY -
REACHING MINNESOTA BY DAYBREAK TUESDAY MORNING. MEANWHILE THE
SURFACE FRONTAL BOUNDARY EVOLVES INTO A CLOSED LOW OVER WISCONSIN BY
THIS EVENING...LIFTING NORTHWARD ACROSS LAKE SUPERIOR INTO WESTERN
ONTARIO BY DAYBREAK TUESDAY. THIS WILL KEEP THE EASTERN THIRD OF
NORTH DAKOTA WITHIN THE WESTERN BOUNDARY OF THE EXPECTED AREA OF
SHOWERS TODAY THROUGH THIS EVENING...WITH CHANCES OF PRECIPITATION
DECREASING DURING THE OVERNIGHT HOURS MONDAY NIGHT.
THE WEST WILL CONTINUE TO DRY OUT AS HIGH PRESSURE CONTINUES TO MOVE
SOUTH/SOUTHEAST INTO THE WESTERN PLAINS. THE PRESSURE GRADIENT
BETWEEN THE STRONG LOW AND HIGH PRESSURE SYSTEMS WILL SET UP FOR
WINDY CONDITIONS TODAY - AND THE CURRENT WIND ADVISORY FOR ALL BUT
THE FAR NORTHWEST SEEMS REASONABLE AND WILL NOT CHANGE AREAL
COVERAGE OR TIMING OF THE WIND ADVISORY. BUFR SOUNDINGS STILL
INDICATE THAT BY AROUND 9-10 AM SHOULD SEE MIXING OF BOUNDARY LAYER
WINDS...RESULTING IN AN AREA OF SUSTAINED 30 MPH WINDS WITH GUSTS TO
40 MPH AT TIMES. USED A CONSENSUS BLEND OF MODELS FOR WIND SPEEDS
WHICH KEEPS THE ADVISORY CRITERIA ACROSS MOST OF THE CWA.
WINDS SHOULD DECREASE FROM WEST TO EAST TONIGHT TO AROUND 10 TO 15
MPH.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 353 AM CDT MON MAY 12 2014
THE 00Z GFS/GEM/ECMWF PROG AN UPPER LOW/WAVE TO CONTINUE TO
MEANDER EAST INTO NORTHEASTERN MANITOBA/NORTHWESTERN ONTARIO
TUESDAY. MOST OF THE MOISTURE/PRECIPITATION CHANCES OVER WESTERN
AND CENTRAL NORTH DAKOTA WILL CONTINUE TO SHIFT EAST IN RESPONSE.
BY WEDNESDAY AND THURSDAY...SYNOPTIC SUBSIDENCE IS PROGGED TO
OVERSPREAD THE STATE LEADING TO DRY CONDITIONS. SURFACE HIGH
PRESSURE IS PROGGED TO SETTLE ACROSS THE STATE THURSDAY MORNING.
THIS COULD LEAD TO LOWS IN THE LOWER 30S/UPPER 20S THURSDAY
MORNING...ESPECIALLY IN LOW-LYING AREAS.
THE MEDIUM RANGE MODELS HAVE BACKED OFF ON A WEAK WAVE PREVIOUSLY
FORECAST TO TRAVERSE NORTH DAKOTA FRIDAY/FRIDAY NIGHT. FOR THE
SAKE OF CONSISTENCY...CONTINUED TO INDICATE SLIGHT CHANCE POPS
FRIDAY/FRIDAY NIGHT. IF THE LATEST TRENDS CONTINUE...FUTURE SHIFTS
MAY NEED TO REMOVE POPS FROM THE FRIDAY FORECAST ALTOGETHER.
AN UPPER LEVEL RIDGE IS THEN FORECAST TO TRANSLATE EAST INTO THE
GREAT PLAINS BY SATURDAY GENERATING DRY CONDITIONS AND NEAR NORMAL
TEMPERATURES.
THE MEDIUM RANGE MODELS ARE SURPRISINGLY CONSISTENT PROGGING A
PACIFIC NORTHWEST LONGWAVE TROUGH TO ENTER THE NORTHERN ROCKIES
SUNDAY. THE POSITION OF THIS FEATURE WARRANTS A CHANCE OF SHOWERS
MENTION FOR NOW...ESPECIALLY ACROSS WESTERN NORTH DAKOTA. COULD
BEGIN TO SEE SOME THUNDER CHANCES SNEAK IN OVER WESTERN NORTH
DAKOTA GIVEN THE FORECAST UPPER PATTERN SUNDAY. HOWEVER...WILL
KEEP THUNDER OUT OF THE FORECAST FOR NOW DUE TO THE UNCERTAINTIES
ASSOCIATED WITH A DAY 7 FORECAST.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 1005 AM CDT MON MAY 12 2014
SCATTERED TO NUMEROUS SHOWERS EXPECTED AT KJMS WITH MVFR CEILINGS
THE PREVAILING CONDITIONS. VFR CLOUDS WILL BE IN PLACE AT THE
REMAINING TAF SITES. STRONG NORTH WINDS EXPECTED ACROSS MOST OF
WESTERN AND CENTRAL NORTH DAKOTA TODAY. SUSTAINED WINDS AROUND 25
KTS AT KDID...KBIS...KMOT AND KJMS WITH GUSTS UP TO AROUND 35 KTS.
WINDS WILL BE NOT AS STRONG AT KISN WITH SUSTAINED 15 T0 20 KNOTS
AND GUSTS TO 30 KTS. WINDS TO SUBSIDE BY AROUND 00Z WEST TO 03Z
EAST.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 7 PM CDT /6 PM MDT/ THIS EVENING FOR
NDZ002>005-010>013-018>023-025-031>037-040>048-050-051.
&&
$$
UPDATE...TWH
SHORT TERM...JV
LONG TERM...TM
AVIATION...TWH
AREA FORECAST DISCUSSION...UPDATED
NWS MORRISTOWN TN
1008 AM EDT MON MAY 12 2014
.DISCUSSION...
AN UPPER-LEVEL RIDGE OF HIGH PRESSURE WILL REMAIN THE DOMINANT
WEATHER FEATURE ACROSS THE FORECAST AREA TODAY...AND HAS PROMOTED
MOSTLY CLEAR CONDITIONS ACROSS THE TENNESSEE VALLEY THIS MORNING
/EXCEPTION OF A FEW BANDS OF HIGH CLOUDS MOVING OVER THE NORTHERN
PLATEAU AND CENTRAL VALLEY/. THE ABUNDANT SUNSHINE AND WARM
TEMPERATURES ALOFT/HIGH THICKNESS VALUES WILL ALLOW FOR A QUICK
WARM-UP INTO THE LOW 80S BY MIDDAY AND A EVENTUALLY INTO THE MID TO
UPPER 80S ACROSS MUCH OF THE VALLEY AGAIN BY THE AFTERNOON /WITH A
FEW SPOTS APPROACHING 90 DEGREES/. WITH MOISTURE UNDERNEATH THIS
RIDGE HOWEVER...THE SOME DIURNALLY DRIVEN CONVECTION IS EXPECTED
/PRIMARILY ALONG THE EAST TENNESSEE/WESTERN NORTH CAROLINA
MOUNTAINS/ THIS AFTERNOON AND EVENING. MODELS ARE ALSO SHOWING SOME
ADDITIONAL CONVECTION FIRING ACROSS SOUTHERN KENTUCKY AND MAKING
ITS WAY ALONG THE NORTHERN PLATEAU AND SOUTHWEST VIRGINIA BY THE
AFTERNOON.
GIVEN THIS...HAVE LOW-END MENTIONABLE POPS IN THESE AREAS AND
CHANCE POPS ALONG THE MOUNTAINS /AS THIS ACTIVITY SHOULD BE
ISOLATED TO SCATTERED IN NATURE/. HOWEVER...KEPT MENTIONABLE POPS
OUT OF THE VALLEY FOR NOW AS THINK MODELS ARE OVER DOING IT
SOMEWHAT WITH THE CAP STILL IN PLACE. THIS THINKING IS SUPPORTED
WELL BY THE HRRR WHICH SHOWS CONVECTION PRIMARILY ALONG THE
MOUNTAINS AND LATE MOVING INTO SW VIRGINIA. THERE WILL BE ENOUGH
INSTABILITY LATER TO SUPPORT SOME STRONG STORMS CAPABLE OF GUSTY
WINDS AND SMALL HAIL ALONG THE MOUNTAINS...WITH THE POTENTIAL FOR
A ROGUE SEVERE STORM OR TWO. HOWEVER...GIVEN THE LACK OF
ORGANIZATION...AM NOT ANTICIPATING ANYTHING MORE THAN A VERY
ISOLATED SEVERE THREAT FOR THOSE AFOREMENTIONED AREAS ATTM.
&&
.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN 88 65 87 64 / 10 10 30 40
KNOXVILLE MCGHEE TYSON AIRPORT, TN 87 63 86 63 / 10 10 30 30
OAK RIDGE, TN 87 63 85 63 / 10 10 30 40
TRI CITIES AIRPORT, TN 85 60 84 60 / 20 10 30 30
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
AMP
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1039 AM CDT MON MAY 12 2014
.UPDATE...
CURRENT FORECAST IS IN GOOD SHAPE AND HAVE ONLY MADE SOME COSMETIC
CHANGES TO THE HOURLY DATA AND MORNING POPS. LATEST SURFACE
ANALYSIS INDICATES THAT THE COLD FRONT IS LOCATED ALONG A LINE
ACROSS CENTRAL OKLAHOMA INTO NORTHWEST TEXAS BETWEEN BOWIE AND
WICHITA FALLS SOUTHWARD TO BRECKENRIDGE. AHEAD OF THE COLD FRONT
AN AREA OF SHOWERS AND THUNDERSTORMS INITIATED ON WHAT APPEARS TO
BE AN INITIAL WAVE OF FORCING OR A SOUTHWARD PROPAGATING GRAVITY
WAVE. EITHER WAY...AMDAR SOUNDING DATA FROM DFW AIRCRAFT INDICATE
THAT STRONG CAPPING INVERSION NOTED ON 12Z FWD SOUNDING WAS ALL
BUT COMPLETELY ERODED IN ABOUT 45 MINUTES. THIS INITIAL WAVE OF
ACTIVITY HAS FAILED TO ORGANIZE OR REALLY TAKE OFF IN INTENSITY
WHICH HAS LEFT THE LOW LEVEL WINDS AND MOISTURE IN PLACE BEHIND
IT. THIS WILL LIKELY HELP TO INITIATE MORE ROBUST THUNDERSTORM
ACTIVITY OVER THE NEXT FEW HOURS AS THE FRONT CONTINUES TO MOVE
SOUTH. LATEST OBJECTIVE ANALYSIS ACROSS NORTH TEXAS SHOWS AROUND
2000 J/KG OF SURFACE BASED INSTABILITY SOUTH/EAST OF THE FRONT
WHERE THE SUN HAS COME OUT A BIT WITH LITTLE INHIBITION LEFT.
EXPECT THUNDERSTORMS TO BECOME MORE NUMEROUS IN COVERAGE THROUGH
EARLY AFTERNOON.
THE SEVERE THREAT REMAINS ACROSS NORTH TEXAS...ESPECIALLY GIVEN
THE STRONG INSTABILITY...HOWEVER DEEP LAYER SHEAR ISNT ALL THAT
STRONG SO MULTICELL CLUSTERS ARE EXPECTED. SOME SEVERE WIND GUSTS
WOULD BE POSSIBLE ALONG WITH SEVERE HAIL. THE MORE SIGNIFICANT
THREAT WILL BE FOR VERY HEAVY RAINFALL AND FLASH
FLOODING...ESPECIALLY ACROSS THE EASTERN COUNTIES WHERE THE FRONT
IS EXPECTED TO SLOWLY MOVE THROUGH TONIGHT. SOME AREAS COULD PICK
UP IN EXCESS OF 3 INCHES OF RAIN IN A SHORT PERIOD OF TIME WITH
ADDITIONAL RAINFALL PERSISTING INTO TONIGHT.
DUNN
&&
.AVIATION...
CONCERNS...TIMING OF CONVECTION AND WIND SHIFT.
...WIDESPREAD DISRUPTIONS ARE EXPECTED THIS AFTERNOON AT DFW AIRPORT
AND DALLAS LOVE FIELD...
A COLD FRONT IS STEADILY APPROACHING FROM THE NORTHWEST. ALTHOUGH
FRONTS TEND TO SLOW DOWN DURING THE DAYLIGHT HOURS...THE MOTION OF
THE BOUNDARY TODAY WILL BE ENHANCED BY CONVECTION. SHOWERS AND
THUNDERSTORMS HAVE ALREADY REDEVELOPED ALONG THE BOUNDARY DURING
THE PREDAWN HOURS...AND ADDITIONAL ACTIVITY MAY DEVELOP WELL IN
ADVANCE OF THE WIND SHIFT THIS MORNING. THIS ACTIVITY WILL
PRIMARILY IMPACT NORTHWEST ARRIVALS THIS MORNING...BUT SOME SHOWERS
OR STORMS COULD OCCUR NEAR METROPLEX AIRPORTS BEFORE MIDDAY. THE
BULK OF THE THUNDERSTORM ACTIVITY IN THE IMMEDIATE METROPLEX WILL
BE DURING THE AFTERNOON HOURS...WHEN A LINE OF STORMS MOVES SLOWLY
THROUGH. WINDS MAY BE CHAOTIC WITH THE ACTIVITY...BUT NORTHWEST
WINDS SHOULD PREVAIL BY MID-AFTERNOON. ALTHOUGH SOME STRONG OR
MARGINALLY SEVERE STORMS WILL BE POSSIBLE WITHIN THE LINE...THE
MAIN IMPACTS TO COMMERCIAL AVIATION TODAY WILL BE FROM LIGHTNING.
SIMILAR IMPACTS ARE EXPECTED AT CENTRAL TEXAS AIRPORTS...BUT THE
ACTIVITY AND WIND SHIFT WILL LIKELY OCCUR A FEW HOURS LATER THAN
IN THE METROPLEX.
THE FRONTAL PASSAGE WILL NOT BRING AN END TO THE PRECIPITATION...
AND RAIN WILL CONTINUE MUCH OF THE EVENING. THE 850MB FRONT MAY BE
AS MUCH AS 12 HOURS BEHIND THE SURFACE BOUNDARY...AND BUOYANT GULF
AIR WILL MAINTAIN INSTABILITY ABOVE THE FRONTAL LAYER SUFFICIENT
FOR THUNDER. HOWEVER...THE THUNDER THIS EVENING AND OVERNIGHT IS
EXPECTED TO BE ISOLATED. TO REDUCE THE NUMBER OF HOURS WITH
THUNDER IN THE TAFS...WILL CARRY PREVAILING RAIN WITHOUT THUNDER.
25
&&
.PREV DISCUSSION... /ISSUED 437 AM CDT MON MAY 12 2014/
THE POTENT UPPER LEVEL LOW OVER THE FOUR CORNERS THAT WAS
RESPONSIBLE FOR SNOW IN DENVER YESTERDAY WILL EJECT NORTHEAST OUT
INTO THE PLAINS TODAY...BUT ADDITIONAL UPPER ENERGY WILL DROP INTO
THE BASE OF A DEEPENING LONGWAVE TROUGH TODAY. THIS UPPER TROUGH
WILL ENGULF THE CENTRAL US BY TOMORROW...A PATTERN THAT IS VERY
UNUSUAL FOR MID MAY. THIS SYSTEM HAS TAPPED INTO A CANADIAN
AIRMASS AND HAS SENT AN UNSEASONABLY STRONG COLD FRONT BARRELING
SOUTH. AT 4AM...THIS FRONT WAS LOCATED JUST SOUTH OF LUBBOCK TO
NEAR VERNON TO EL RENO OKLAHOMA AND WAS MOVING SOUTHEAST AT 15 TO
20MPH. THE FRONT IS AHEAD OF MOST MODEL PROJECTIONS...WHICH IS
NOT SURPRISING GIVEN THE COLD AIR BEHIND IT. THE RAP HAS A GOOD
HANDLE ON THE FRONT/S SPEED AND IT WILL BE USED FOR TIMING.
THE FRONT WILL ARRIVE INTO THE NORTHWEST CWA BY MID-MORNING AND
CONTINUE TO TRACK SOUTHEAST...BUT SLOW DOWN A BIT DUE TO DAYTIME
HEATING. THE FRONT SHOULD REACH A SHERMAN TO DFW TO COMANCHE LINE
BY MID-AFTERNOON. THE AIRMASS AHEAD OF THE FRONT WILL BE WARM AND
MOIST...WITH SEVERAL DAYS OF SOUTHERLY FLOW NOW BRINGING
PRECIPITABLE WATER VALUES UP TO 1.75 TO 2 INCHES. SURFACE BASED
CAPE WILL PEAK AROUND 2000-2500 J/KG THIS AFTERNOON AS TEMPS WARM
INTO THE MID 80S. DAYTIME HEATING AND FORCING FOR ASCENT FROM THE
UPPER LEVEL TROUGH WILL LIFT/ERODE THE WEAK CAPPING
INVERSION...AND THUS CONVECTION WILL INCREASE IN COVERAGE ALONG
THE FRONT BY LATE MORNING. BULK LAYER SHEAR IS FAIRLY WEAK...ON
THE ORDER OF 25KT...SO MULTICELLULAR CONVECTIVE MODES ARE
EXPECTED. GIVEN THE HIGH INSTABILITY AND WEAK SHEAR...SOME SEVERE
WIND/HAIL REPORTS ARE POSSIBLE TODAY WITH THE STRONGEST STORMS.
CONVECTION ALONG THE FRONT WILL LIKELY CONGEAL INTO A SOLID LINE
OF THUNDERSTORMS BY MID-AFTERNOON...WITH THE LINE CONTINUING TO
GROW UPSCALE INTO A FORMIDABLE LINEAR MCS BY THE EVENING HOURS.
MCS PROPAGATION VECTORS AND DIFFLUENT THICKNESS FIELDS ALOFT
SUGGEST THAT THE MOVEMENT OF THIS SYSTEM WILL REMAIN FAIRLY
SLOW...LIKELY LESS THAN 10-15MPH. THIS FORWARD SPEED SHOULD IN
THEORY LIMIT THE DAMAGING WIND THREAT THIS EVENING OVER THE
SOUTHEAST HALF OF THE CWA...BUT WILL RESULT IN ENHANCED RAINFALL
TOTALS. THE MCS WILL LIKELY HAVE SLOWER WEST TO EAST MOVEMENT THAN
NORTH TO SOUTH...AND THUS THE ORIENTATION OF THE LINE SUGGESTS
THAT EASTERN ZONES WILL HAVE A GREATER RISK FOR PROLONGED HEAVY
RAINFALL. EXPECT THE LINE TO PUSH THROUGH THE SOUTHWEST ZONES
FAIRLY QUICKLY...LIKELY REACHING A LAMPASAS TO WACO LINE BY 6 PM.
A TIGHT RAINFALL GRADIENT IS FORECAST OVER THE CWA WITH LESS THAN
A HALF INCH EXPECTED OVER THE NW ZONES...TO 1-2 INCHES IN A BAND
FROM THE SHERMAN AREA TO THE METROPLEX TO COMANCHE...AND 2-3
INCHES SOUTH AND EAST OF A PARIS TO GREENVILLE TO HILLSBORO LINE.
THIS LATTER REGION WAS THE SAME AREA THAT RECEIVED A SWATH OF 2-4
INCHES OF RAIN THURSDAY AND SOILS ARE ALREADY SATURATED. THUS A
FLASH FLOOD WATCH WAS ISSUED FOR LOCATIONS ALONG AND SOUTHEAST OF
A BONHAM TO DALLAS TO TEMPLE LINE. WHILE WE DONT EXPECT MOST OF
DALLAS AND COLLIN COUNTIES TO RECEIVE MORE THAN 2 INCHES...GIVEN
THE URBAN DEVELOPMENT THERE AND THE FACT THAT THE SOUTHEAST PARTS
OF THESE COUNTIES DID SEE OVER 4 INCHES...FELT IT WAS BEST TO
INCLUDE THEM. FARTHER SOUTH...FROM WACO TO ATHENS...LESS RAIN FELL
IN THIS AREA LAST THURSDAY...BUT QUICK TOTALS OF 2-3 INCHES ARE
POSSIBLE THIS EVENING. FOR WACO/TEMPLE/KILLEEN ONLY AROUND 2
INCHES ARE FORECAST...BUT AGAIN URBAN INFRASTRUCTURE MAY
EXACERBATE ANY FLOODING...SO THEY WERE INCLUDED IN THE WATCH TOO.
BECAUSE THE UPPER LEVEL TROUGH WILL BE SLOW TO MOVE
EAST...CONTINUED SOUTHERLY FLOW ALOFT BEHIND THE FRONT/LINE OF
STORMS WILL OCCUR THIS EVENING. THUS THE LINE OF STORMS WILL
LIKELY BE SUCCEEDED BY A FEW HOURS OF STEADY LIGHT TO MODERATE
STRATIFORM RAINS...ESPECIALLY ACROSS THE WATCH AREA. THIS ACTIVITY
SHOULD END FROM NORTHWEST TO SOUTHEAST LATE TONIGHT...BUT MAY
LINGER OVER THE SOUTHEAST ZONES INTO TUESDAY MORNING. TUESDAY
SHOULD BE DRY FOR THE REMAINDER OF THE AREA WITH MOSTLY CLOUDY AND
COOL CONDITIONS AS COOLER AIR POURS INTO THE REGION BEHIND THE
FRONT. FORECAST HIGH TEMPS MAY BE TOO WARM...BUT IT WOULD ONLY
TAKE AN HOUR OR TWO OF AFTERNOON MAY SUNSHINE TO WARM US INTO THE
MID 60S...SO STAYED CONSERVATIVE THERE.
THE STRONGEST UPPER LEVEL FORCING WILL CROSS THE REGION TUESDAY
EVENING BUT THE AIRMASS WILL BE PRETTY WORKED OVER. HOWEVER THIS
FORCING SHOULD RESULT IN SCATTERED ELEVATED SHOWERS AND A FEW
STORMS OVER THE REGION AND SHOULD SQUEEZE OUT ANOTHER TENTH TO
QUARTER INCH OF RAINFALL. HAVE BUMPED POPS UP TUESDAY NIGHT AS
MODEL GUIDANCE HAS COME INTO BETTER AGREEMENT ON THIS ROUND.
OTHERWISE THE REMAINDER OF THE FORECAST LOOKS QUIET AND VERY NICE
FOR MID TO LATE MAY. DRY NORTHWESTERLY FLOW ALOFT WILL PREVAIL
THROUGH THE WEEKEND LEADING TO CLEAR SKIES AND LIGHT WINDS. GOOD
RADIATIONAL COOLING WEDNESDAY NIGHT WILL SEND LOW TEMPS DOWN INTO
THE 40S AREA WIDE...AND WACO MAY BREAK ITS RECORD LOW OF 46. HIGHS
IN THE UPPER 60S ARE EXPECTED THURSDAY...BUT TEMPS SHOULD WARM
INTO THE 70S FRIDAY AND THE 80S BY THE WEEKEND. DRY WEATHER WILL
CONTINUE INTO NEXT WEEK WITH TEMPS WARMING TO ABOVE NORMAL.
TR.92
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 83 54 66 51 68 / 90 80 20 40 10
WACO, TX 87 57 65 51 69 / 70 100 40 60 10
PARIS, TX 84 56 63 51 64 / 70 90 20 50 20
DENTON, TX 80 52 65 49 68 / 80 70 20 40 10
MCKINNEY, TX 83 53 64 50 68 / 90 80 20 40 10
DALLAS, TX 84 55 65 52 68 / 90 80 20 50 10
TERRELL, TX 85 57 64 51 67 / 70 90 20 50 20
CORSICANA, TX 86 59 64 52 67 / 60 100 40 60 20
TEMPLE, TX 87 58 64 52 69 / 50 100 50 60 10
MINERAL WELLS, TX 80 50 66 47 71 / 70 60 20 30 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM 4 PM CDT THIS AFTERNOON THROUGH LATE
TONIGHT FOR TXZ094-095-104>107-119>123-134-135-145>148-158>162-
174-175.
&&
$$
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
634 AM CDT MON MAY 12 2014
.AVIATION...
/12Z TAFS/
Stratus will remain over the Heartland and Northwest Hill Country
through mid morning and then will dissipate. Going with MVFR CIGS at
the KJCT and KBBD terminals until 16Z. Mainly VFR conditions are
expected the rest of the TAF forecast. Isolated to scattered
thunderstorms will be possible east of an Abilene to
San Angelo line mainly this afternoon and tonight. Storms may even
be more numerous by tonight east of a Coleman to Junction line. The
models are developing an MCS along a cold front by 06Z Tuesday and
moving it slowly east into central Texas. However, confidence is
only high enough to add VCTS to the terminals through 02Z Tuesday.
Winds will be south and then become north as cold front moves
through West Central Texas today and this evening.
&&
.PREV DISCUSSION... /ISSUED 442 AM CDT MON MAY 12 2014/
SHORT TERM...
(Today and Tonight)
WV imagery this morning was showing and a strong upper level trough
over the central and southern Rockies with a mid level speed max of
50 to 70 knots rotating out in the Plains. Upper level flow has
backed to southwest over Texas. Also, a lot mid and upper subsidence
evident which is still resulting in a strong cap over West Central
Texas. At the surface, a cold front was located along a Quanah to
Seminole line. A dryline extended south along a Wink to Sanderson
line. Not much happening yet convection wise as low level inhibition
and cap is still holding strong. A few showers have developed just
behind the cold front across northwest Texas. The airmass was very
moist across our area with southerly flow and dewpoints in the mid
to upper 60s.
For today, the chance of showers and thunderstorms will increase mid
morning through the afternoon across mainly the eastern half of the
CWFA. The cold front will continue southeast into West Central Texas
and will probably slow its forward speed. Scattered showers and
thunderstorms will develop along and behind the front as elevated
instability erases the cap. The HRRR convective allowing model is
showing best coverage of activity east of an Abilene to San Angelo
line. The combination of good instability in the warm sector and
weak 0-6KM shear of 25 to 30 knots will result in multicell storms
with possible brief supercell structures. A few strong to severe
storms are possible across mainly the Heartland and Northwest Hill
Country. The main hazards will be large hail, damaging winds and
dangerous cloud to ground lightning. Going with mainly chance to
slight chance POPS for today. Temperatures will be cooler with highs
in the 80s.
For tonight, There will be a chance of showers thunderstorms across
much of our area with better coverage of storms east of a Coleman to
Sonora line. a few storms may be severe. The main hazards will be
large hail, damaging winds and dangerous cloud to ground lightning
mainly before 06Z Tuesday. The bigger focus will be the potential
for locally heavy rainfall across the Heartland and Northwest Hill
Country, due to good low level southerly flow. moisture flux
convergence along a slow moving cold front, PWAT values of 1.5 to
1.75 inches and in the RRQ of highly amplified 250MB jet. Rainfall
amounts of 1 to 2 inches with locally heavy amounts are possible
along and east of a Brownwood to Junction line. Also, going with
LKLY to CAT POPS across the southeast CWFA.
LONG TERM...
(Tuesday through next Monday)
The cold front will be well south of the area early Tuesday morning,
with the upper level trough axis over New Mexico. Showers and
thunderstorms may be ongoing across far southeast sections early
Tuesday morning but will move east of the area by mid to late
morning. Additional showers and isolated thunderstorms will be
possible across much of the area during the day as lift increases
ahead of the approaching upper trough. Moisture will be limited, so
precipitation is expected to be light, with most areas seeing one
tenth inch or less of rainfall. It will be considerably cooler on
Tuesday with highs well below normal for this time of year. NAM
guidance looks too cool with highs in the upper 50s, so went with a
GFS/NAM blend, which looks more reasonable with highs topping out in
the lower 60s. Lingering showers will be possible Tuesday evening
over southeast sections, otherwise dry conditions are expected
overnight with clearing skies, as drier air filters in behind the
departing upper trough. Temperatures will be very chilly Wednesday
night with overnight lows in the lower and middle 40s.
Dry and cool weather will continue on Wednesday with sunny skies,
light winds and highs in the lower 70s. Another cool night is in
store Wednesday night with low temperatures again in the 40s. Will
maintain a dry forecast Thursday into next weekend with a warming
trend through the period. Northwest flow aloft is expected through
Saturday, with a short wave ridge overspreading the Plains on
Sunday. High temperatures will warm from the mid 80s late week, to
the upper 80s and lower 90s by the end of the weekend. Expect
overnight lows in the 50s, warming into the 60s through the
period.
FIRE WEATHER...
Elevated fire weather conditions will be possible across much of
West Central Texas Wednesday through Friday, as minimum relative
humidity values drop to 15 to 20 percent, but 20 foot winds
generally remain below 15 mph.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 80 50 63 45 72 / 40 20 20 10 0
San Angelo 86 52 62 43 73 / 30 20 20 10 0
Junction 85 57 64 46 73 / 50 70 40 20 0
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
21/24
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
608 AM CDT MON MAY 12 2014
.AVIATION...
CONCERNS...TIMING OF CONVECTION AND WIND SHIFT.
...WIDESPREAD DISRUPTIONS ARE EXPECTED THIS AFTERNOON AT DFW AIRPORT
AND DALLAS LOVE FIELD...
A COLD FRONT IS STEADILY APPROACHING FROM THE NORTHWEST. ALTHOUGH
FRONTS TEND TO SLOW DOWN DURING THE DAYLIGHT HOURS...THE MOTION OF
THE BOUNDARY TODAY WILL BE ENHANCED BY CONVECTION. SHOWERS AND
THUNDERSTORMS HAVE ALREADY REDEVELOPED ALONG THE BOUNDARY DURING
THE PREDAWN HOURS...AND ADDITIONAL ACTIVITY MAY DEVELOP WELL IN
ADVANCE OF THE WIND SHIFT THIS MORNING. THIS ACTIVITY WILL
PRIMARILY IMPACT NORTHWEST ARRIVALS THIS MORNING...BUT SOME SHOWERS
OR STORMS COULD OCCUR NEAR METROPLEX AIRPORTS BEFORE MIDDAY. THE
BULK OF THE THUNDERSTORM ACTIVITY IN THE IMMEDIATE METROPLEX WILL
BE DURING THE AFTERNOON HOURS...WHEN A LINE OF STORMS MOVES SLOWLY
THROUGH. WINDS MAY BE CHAOTIC WITH THE ACTIVITY...BUT NORTHWEST
WINDS SHOULD PREVAIL BY MID-AFTERNOON. ALTHOUGH SOME STRONG OR
MARGINALLY SEVERE STORMS WILL BE POSSIBLE WITHIN THE LINE...THE
MAIN IMPACTS TO COMMERCIAL AVIATION TODAY WILL BE FROM LIGHTNING.
SIMILAR IMPACTS ARE EXPECTED AT CENTRAL TEXAS AIRPORTS...BUT THE
ACTIVITY AND WIND SHIFT WILL LIKELY OCCUR A FEW HOURS LATER THAN
IN THE METROPLEX.
THE FRONTAL PASSAGE WILL NOT BRING AN END TO THE PRECIPITATION...
AND RAIN WILL CONTINUE MUCH OF THE EVENING. THE 850MB FRONT MAY BE
AS MUCH AS 12 HOURS BEHIND THE SURFACE BOUNDARY...AND BUOYANT GULF
AIR WILL MAINTAIN INSTABILITY ABOVE THE FRONTAL LAYER SUFFICIENT
FOR THUNDER. HOWEVER...THE THUNDER THIS EVENING AND OVERNIGHT IS
EXPECTED TO BE ISOLATED. TO REDUCE THE NUMBER OF HOURS WITH
THUNDER IN THE TAFS...WILL CARRY PREVAILING RAIN WITHOUT THUNDER.
25
&&
.PREV DISCUSSION... /ISSUED 437 AM CDT MON MAY 12 2014/
THE POTENT UPPER LEVEL LOW OVER THE FOUR CORNERS THAT WAS
RESPONSIBLE FOR SNOW IN DENVER YESTERDAY WILL EJECT NORTHEAST OUT
INTO THE PLAINS TODAY...BUT ADDITIONAL UPPER ENERGY WILL DROP INTO
THE BASE OF A DEEPENING LONGWAVE TROUGH TODAY. THIS UPPER TROUGH
WILL ENGULF THE CENTRAL US BY TOMORROW...A PATTERN THAT IS VERY
UNUSUAL FOR MID MAY. THIS SYSTEM HAS TAPPED INTO A CANADIAN
AIRMASS AND HAS SENT AN UNSEASONABLY STRONG COLD FRONT BARRELING
SOUTH. AT 4AM...THIS FRONT WAS LOCATED JUST SOUTH OF LUBBOCK TO
NEAR VERNON TO EL RENO OKLAHOMA AND WAS MOVING SOUTHEAST AT 15 TO
20MPH. THE FRONT IS AHEAD OF MOST MODEL PROJECTIONS...WHICH IS
NOT SURPRISING GIVEN THE COLD AIR BEHIND IT. THE RAP HAS A GOOD
HANDLE ON THE FRONT/S SPEED AND IT WILL BE USED FOR TIMING.
THE FRONT WILL ARRIVE INTO THE NORTHWEST CWA BY MID-MORNING AND
CONTINUE TO TRACK SOUTHEAST...BUT SLOW DOWN A BIT DUE TO DAYTIME
HEATING. THE FRONT SHOULD REACH A SHERMAN TO DFW TO COMANCHE LINE
BY MID-AFTERNOON. THE AIRMASS AHEAD OF THE FRONT WILL BE WARM AND
MOIST...WITH SEVERAL DAYS OF SOUTHERLY FLOW NOW BRINGING
PRECIPITABLE WATER VALUES UP TO 1.75 TO 2 INCHES. SURFACE BASED
CAPE WILL PEAK AROUND 2000-2500 J/KG THIS AFTERNOON AS TEMPS WARM
INTO THE MID 80S. DAYTIME HEATING AND FORCING FOR ASCENT FROM THE
UPPER LEVEL TROUGH WILL LIFT/ERODE THE WEAK CAPPING
INVERSION...AND THUS CONVECTION WILL INCREASE IN COVERAGE ALONG
THE FRONT BY LATE MORNING. BULK LAYER SHEAR IS FAIRLY WEAK...ON
THE ORDER OF 25KT...SO MULTICELLULAR CONVECTIVE MODES ARE
EXPECTED. GIVEN THE HIGH INSTABILITY AND WEAK SHEAR...SOME SEVERE
WIND/HAIL REPORTS ARE POSSIBLE TODAY WITH THE STRONGEST STORMS.
CONVECTION ALONG THE FRONT WILL LIKELY CONGEAL INTO A SOLID LINE
OF THUNDERSTORMS BY MID-AFTERNOON...WITH THE LINE CONTINUING TO
GROW UPSCALE INTO A FORMIDABLE LINEAR MCS BY THE EVENING HOURS.
MCS PROPAGATION VECTORS AND DIFFLUENT THICKNESS FIELDS ALOFT
SUGGEST THAT THE MOVEMENT OF THIS SYSTEM WILL REMAIN FAIRLY
SLOW...LIKELY LESS THAN 10-15MPH. THIS FORWARD SPEED SHOULD IN
THEORY LIMIT THE DAMAGING WIND THREAT THIS EVENING OVER THE
SOUTHEAST HALF OF THE CWA...BUT WILL RESULT IN ENHANCED RAINFALL
TOTALS. THE MCS WILL LIKELY HAVE SLOWER WEST TO EAST MOVEMENT THAN
NORTH TO SOUTH...AND THUS THE ORIENTATION OF THE LINE SUGGESTS
THAT EASTERN ZONES WILL HAVE A GREATER RISK FOR PROLONGED HEAVY
RAINFALL. EXPECT THE LINE TO PUSH THROUGH THE SOUTHWEST ZONES
FAIRLY QUICKLY...LIKELY REACHING A LAMPASAS TO WACO LINE BY 6 PM.
A TIGHT RAINFALL GRADIENT IS FORECAST OVER THE CWA WITH LESS THAN
A HALF INCH EXPECTED OVER THE NW ZONES...TO 1-2 INCHES IN A BAND
FROM THE SHERMAN AREA TO THE METROPLEX TO COMANCHE...AND 2-3
INCHES SOUTH AND EAST OF A PARIS TO GREENVILLE TO HILLSBORO LINE.
THIS LATTER REGION WAS THE SAME AREA THAT RECEIVED A SWATH OF 2-4
INCHES OF RAIN THURSDAY AND SOILS ARE ALREADY SATURATED. THUS A
FLASH FLOOD WATCH WAS ISSUED FOR LOCATIONS ALONG AND SOUTHEAST OF
A BONHAM TO DALLAS TO TEMPLE LINE. WHILE WE DONT EXPECT MOST OF
DALLAS AND COLLIN COUNTIES TO RECEIVE MORE THAN 2 INCHES...GIVEN
THE URBAN DEVELOPMENT THERE AND THE FACT THAT THE SOUTHEAST PARTS
OF THESE COUNTIES DID SEE OVER 4 INCHES...FELT IT WAS BEST TO
INCLUDE THEM. FARTHER SOUTH...FROM WACO TO ATHENS...LESS RAIN FELL
IN THIS AREA LAST THURSDAY...BUT QUICK TOTALS OF 2-3 INCHES ARE
POSSIBLE THIS EVENING. FOR WACO/TEMPLE/KILLEEN ONLY AROUND 2
INCHES ARE FORECAST...BUT AGAIN URBAN INFRASTRUCTURE MAY
EXACERBATE ANY FLOODING...SO THEY WERE INCLUDED IN THE WATCH TOO.
BECAUSE THE UPPER LEVEL TROUGH WILL BE SLOW TO MOVE
EAST...CONTINUED SOUTHERLY FLOW ALOFT BEHIND THE FRONT/LINE OF
STORMS WILL OCCUR THIS EVENING. THUS THE LINE OF STORMS WILL
LIKELY BE SUCCEEDED BY A FEW HOURS OF STEADY LIGHT TO MODERATE
STRATIFORM RAINS...ESPECIALLY ACROSS THE WATCH AREA. THIS ACTIVITY
SHOULD END FROM NORTHWEST TO SOUTHEAST LATE TONIGHT...BUT MAY
LINGER OVER THE SOUTHEAST ZONES INTO TUESDAY MORNING. TUESDAY
SHOULD BE DRY FOR THE REMAINDER OF THE AREA WITH MOSTLY CLOUDY AND
COOL CONDITIONS AS COOLER AIR POURS INTO THE REGION BEHIND THE
FRONT. FORECAST HIGH TEMPS MAY BE TOO WARM...BUT IT WOULD ONLY
TAKE AN HOUR OR TWO OF AFTERNOON MAY SUNSHINE TO WARM US INTO THE
MID 60S...SO STAYED CONSERVATIVE THERE.
THE STRONGEST UPPER LEVEL FORCING WILL CROSS THE REGION TUESDAY
EVENING BUT THE AIRMASS WILL BE PRETTY WORKED OVER. HOWEVER THIS
FORCING SHOULD RESULT IN SCATTERED ELEVATED SHOWERS AND A FEW
STORMS OVER THE REGION AND SHOULD SQUEEZE OUT ANOTHER TENTH TO
QUARTER INCH OF RAINFALL. HAVE BUMPED POPS UP TUESDAY NIGHT AS
MODEL GUIDANCE HAS COME INTO BETTER AGREEMENT ON THIS ROUND.
OTHERWISE THE REMAINDER OF THE FORECAST LOOKS QUIET AND VERY NICE
FOR MID TO LATE MAY. DRY NORTHWESTERLY FLOW ALOFT WILL PREVAIL
THROUGH THE WEEKEND LEADING TO CLEAR SKIES AND LIGHT WINDS. GOOD
RADIATIONAL COOLING WEDNESDAY NIGHT WILL SEND LOW TEMPS DOWN INTO
THE 40S AREA WIDE...AND WACO MAY BREAK ITS RECORD LOW OF 46. HIGHS
IN THE UPPER 60S ARE EXPECTED THURSDAY...BUT TEMPS SHOULD WARM
INTO THE 70S FRIDAY AND THE 80S BY THE WEEKEND. DRY WEATHER WILL
CONTINUE INTO NEXT WEEK WITH TEMPS WARMING TO ABOVE NORMAL.
TR.92
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 83 54 66 51 68 / 90 80 20 40 10
WACO, TX 87 57 65 51 69 / 70 100 40 60 10
PARIS, TX 84 56 63 51 64 / 70 90 20 50 20
DENTON, TX 80 52 65 49 68 / 80 70 20 40 10
MCKINNEY, TX 83 53 64 50 68 / 90 80 20 40 10
DALLAS, TX 84 55 65 52 68 / 90 80 20 50 10
TERRELL, TX 85 57 64 51 67 / 70 90 20 50 20
CORSICANA, TX 86 59 64 52 67 / 60 100 40 60 20
TEMPLE, TX 87 58 64 52 69 / 50 100 50 60 10
MINERAL WELLS, TX 79 50 66 47 71 / 70 60 20 30 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM 4 PM CDT THIS AFTERNOON THROUGH LATE
TONIGHT FOR TXZ094-095-104>107-119>123-134-135-145>148-158>162-
174-175.
&&
$$
25/92
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
843 AM EDT MON MAY 12 2014
.SYNOPSIS...
HIGH PRESSURE OFF THE SOUTHEAST COAST IS GOING TO KEEP OUR REGION
IN A INCREASINGLY HUMID AIRMASS. A SLOW MOVING FRONT ENTERS THE
REGION BY THURSDAY AND SLIDES EAST FRIDAY. A COOLER AIRMASS
FOLLOWS THIS FRONT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 700 AM EDT MONDAY...
FEW SHOWERS ACROSS GREENBRIER COUNTY WV THIS MORNING...OTHERWISE
MAINLY SEEING SOME AC/CI. UPDATES JUST REFLECT TRENDS IN TEMPS/SKY
COVER WITH ISOLATED POPS IN THE NW CWA.
PREVIOUS VALID DISCUSSION...
DESPITE INCREASING 5H HEIGHTS TODAY...WILL STILL SEE A COUPLE OF
EMBEDDED SHORTWAVES RIDE THE NRN CENTER OF THE HIGH ACROSS OUR AREA.
EARLY THIS MORNING...THERE IS A WEAK SHORTWAVE MOVING ACROSS WV
WITH TAIL END OF SHOWERS PUSHING EAST BETWEEN BKW-CRW BUT WEAKENING.
THE LATEST HRRR SHOWS THIS AREA MAYBE SCRAPING NRN GREENBRIER AND
BATH. OVERALL...SHOULD BE A DRY MORNING WITH PATCH FOG IN THE
VALLEYS/RIVER AREAS.
TODAY...THE SFC HIGH OFF THE COAST WILL CONTINUE TO KEEP MOISTURE
STREAMING NWD INTO THE CENTRAL APPALACHIANS. HEATING WILL LEAD TO
INSTABILITY AND OVERALL WEAK FORCING FAVORS SCATTERED SHOWERS AND
STORMS POPPING AROUND MIDDAY IN THE MTNS WITH STEERING FLOW TAKING
THEM EAST TO THE BLUE RIDGE AND FOOTHILLS DURING THE AFTERNOON.
FURTHER SOUTH ACROSS NC/SOUTHSIDE VA...AIRMASS MAY BE JUST CAPPED
ENOUGH TO LIMIT CONVECTION...ALTHOUGH A FEW SHOULD SKIRT BY THIS
EVENING WHEN CAP WEAKENS. OVERALL KEPT POPS UNDER HIGH CHANCE...BUT
WILL BE A CASE WHERE 1/3-1/2 OF A COUNTY GETS RAINED ON...WHILE THE
OTHER HALF MISSES OUT.
FOR HIGHS WILL SEE MOSTLY SUNNY SKIES EARLY WITH CU/TCU DEVELOPING
WITH SOME AC/CI OVERTOP. THIS WILL LIMIT HEATING MAINLY OVER THE
MOUNTAINS BUT STILL LOOKING AT TEMPS RUNNING AROUND 10 DEGREES ABOVE
NORMAL. HIGHS RANGING FROM THE UPPER 70S/LOWER 80S WEST TO NEAR 90
SOUTHEAST.
TONIGHT...CONVECTION WEAKENS WITH LOSS OF HEATING. THE 00Z WRF/NAM
HOLD ONTO ACTIVITY INTO LATE EVENING WHILE THE OTHER MODELS SHOWING
LITTLE TO NONE AFTER 00Z/8 PM. WILL LEAN TOWARD THE HIGHER RES
MODELS SINCE ANY OUTFLOW COULD KEEP A SHOWER/STORM GOING PAST 8 PM.
BY MIDNIGHT WILL BE CLEAR TO PARTLY CLOUDY AND HUMID WITH LOWS IN
THE UPPER 50S TO LOWER 60S. FOG COULD BECOME AN ISSUE SINCE RAIN
SHOWERS ARE EXPECTED THIS AFTERNOON...ALTHOUGH COVERAGE WILL BE
PATCHY.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/...
AS OF 415 AM EDT MONDAY...
UPPER LEVEL RIDGING WILL BE FIRMLY IN PLACE TUESDAY MORNING ACROSS
THE EASTERN SEABOARD...WHICH WILL RESULT IN VERY SUMMER LIKE
TEMPERATURES. EXPECT AFTERNOON HIGHS TO RANGE FROM THE LOW/MID 80S
ACROSS THE MOUNTAINS... TO THE LOW 90S ACROSS THE SOUTHSIDE. STRONG
HEATING AND CONTINUED MOISTURE INFLOW SHOULD HELP KICK OFF A FEW
SHOWERS AND THUNDERSTORMS DURING LATE AFTERNOON AND EARLY EVENING...
HOWEVER THE RIDGING WILL KEEP THIS ACTIVITY SPOTTY AT BEST AND
DISORGANIZED. WILL BE KEEPING AN EYE ON A COLD FRONT BACK DOORING
ITS WAY SOUTHWARD FROM NEW ENGLAND DURING THE AFTERNOON AND
EVENING...BUT DO NOT THINK IT WILL APPROACH CLOSE ENOUGH TO ENHANCE
CONVECTION OVER OUR AREA. AT ANY RATE...ANY CONVECTION SHOULD
GRADUALLY FIZZLE TOWARD SUNSET...AND PATCHY FOG WILL BE POSSIBLE
TUESDAY NIGHT...ESPECIALLY IN AREAS WHICH DO RECEIVE A DOWNPOUR.
BETTER CHANCES FOR SHOWER AND THUNDERSTORMS WILL OCCUR ON WEDNESDAY
AS UPPER LEVEL RIDGING BEGINS TO SHIFT EAST...WHILE THE BACK DOOR
FRONT STALLS ACROSS NORTHERN VIRGINIA JUST OUTSIDE OUR FORECAST
REGION. ANOTHER DAY OF STRONG HEATING AS HIGHS REACH INTO THE 80S
MOST LOCATIONS...COMBINED WITH LOW LEVEL CONVERGENCE ASSOCIATED WITH
THE NEARBY FRONT...WILL LEAD TO HIGHER RAIN CHANCES ACROSS THE
MOUNTAINS AND THE PIEDMONT NORTH OF HIGHWAY 460. THE INCREASED
INSTABILITY WILL ALLOW FOR GREATER POTENTIAL FOR ORGANIZED
THUNDERSTORM ACTIVITY...AND A FEW STORMS WILL LIKELY BECOME STRONG
DURING LATE AFTERNOON AND EARLY EVENING...CAPABLE OF PRODUCING
LOCALLY STRONG WINDS AND HAIL. WILL SEE THE BOUNDARY ACROSS NORTHERN
VIRGINIA LIFT TOWARD NEW ENGLAND DURING LATE EVENING AS A WARM
FRONT...WHILE A STRONG COLD FRONT APPROACHES OUR REGION FROM THE
WEST.
THE COLD FRONT WILL ENTER OUR WESTERN MOST COUNTIES DURING MID
AFTERNOON...RESULTING IN WAVES OF LOCALLY HEAVY RAIN AS UPPER LEVEL
DISTURBANCES PASS OVERHEAD ALONG THE BOUNDARY. MODELS ARE PICKING UP
ON AT LEAST ONE STRONG WAVE POTENTIALLY BRINGING HEAVY RAIN TO THE
FOOTHILLS AND THE PIEDMONT DURING THE EVENING...AND POSSIBLY A
SECOND WAVE IF THE COLD FRONT SLOWS/STALLS BEFORE EXITING OUR REGION
DURING EARLY FRIDAY MORNING. STILL NOT ENOUGH CONFIDENCE IN THE
MODELS TO TACK DOWN RAINFALL AMOUNTS...BUT IT IS LOOKING SAFE TO SAY
THAT THE MUCH OF THE REGION WILL RECEIVE BETWEEN ONE AND TWO INCHES
FOR THE THURSDAY AND EARLY FRIDAY TIME PERIOD...WITH SOME AREAS
PICKING IN EXCESS OF 3 INCHES...ESPECIALLY ALONG THE BLUE RIDGE.
MODELS ARE IN DECENT AGREEMENT THAT THE FRONT AND ASSOCIATED HEAVY
RAIN WILL BE EAST OF OUR AREA DURING EARLY FRIDAY AFTERNOON...
LEAVING ONLY RESIDUAL SHOWER ACTIVITY...AS WELL AS A SHARP DROP IN
TEMPERATURES AS A DEEP UPPER TROUGH APPROACHES FROM THE WEST.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 400 PM EDT SUNDAY...
AN AMPLIFIED MID-UPPER LEVEL MEAN TROUGH SETTLES OVER THE ERN HALF
OF THE CONUS FOR THE LATTER HALF OF THE WEEK AND INTO NEXT
WEEKEND.
AS WE TRANSITION INTO THE WEEKEND...FLOW BECOMES BLOCKY WITH A
DEEP QUASI-STATIONARY...ALMOST WINTERLIKE UPPER LOW PARKED OVER
THE GREAT LAKES REGION. 850MB TEMPS WILL DROP INTO THE 3C TO 6C
RANGE FOR MOST OF THE CWA AND LINGER IN THIS RANGE FOR SEVERAL
DAYS. SEVERAL SPOKES OF PVA ARE EXPECTED TO ROTATE AROUND THIS
UPPER LOW WHICH SUGGESTS POTENTIAL FOR CLOUDS AND SHOWERS...
ESPECIALLY ACROSS THE MOUNTAINS. TEMPERATURES WILL TREND TO THE
COOLER SIDE OF NORMAL. FORTUNATELY...CLOUDS...SHOWERS...AND A BIT
OF A NW BREEZE SHOULD MITIGATE FROST POTENTIAL. NONETHELESS...IT
WILL BE QUITE CHILLY WITH HIGHS IN THE 60S AND LOWS IN THE 40S
ACROSS MUCH OF THE REGION...A BIG CONTRAST FROM THE WARMTH THE
FIRST HALF OF THIS WEEK.
&&
.AVIATION /13Z MONDAY THROUGH FRIDAY/...
AS OF 710 AM EDT MONDAY...
NOT MUCH CHANGE FROM PREVIOUS TAFS. MODELS STILL SHOWING A
SCATTERING OF CONVECTION BETWEE 16-18Z TODAY OVER THE
MOUNTAINS...AND SKIRTING TOWARD LYH BY 20Z. STILL TOO LOOSE OF
COVERAGE TO HAVE ANYTHING MORE THAN VCTS IN THE TAFS ASIDE FROM
BLF. ASIDE FROM THE STORMS...EXPECT VFR.
THIS EVENING...CONVECTION WANES AND SKIES WILL BE CLEAR/PC AND
VFR. SOME MVFR VSBYS AND POSSIBLY LOWER OVERNIGHT. WILL HAVE TO
SEE WHERE IT RAINS THIS AFTERNOON WHICH CAN SET UP MORE FOG
OVERNIGHT. RIGHT NOW CONFIDENCE HIGH THAT AT LEAST THE CLIMO
FAVORED STATIONS OF LWB/BCB GET MVFR VSBYS OVERNIGHT.
FORECAST FAVORS SLOWING OF THE FRONT SO THAT NOW EVEN WEDNESDAY
COULD HAVE LESS COVERAGE. UNTIL THE FRONT GETS CLOSER EXPECT
MAINLY VFR WITH POP UP STORMS IN THE AFTERNOON...AND MAYBE FOG
ENTERING THE PICTURE MORE OVERNIGHT AT MOST SITES OUTSIDE OF
BLF/LWB.
HEAVY RAINS AND STORMS WILL BE AFFECTING OUR REGION BY THURSDAY
AND COULD LINGER INTO EARLY FRIDAY. SO DURING THE WED-FRI TIME
FRAME GOOD CHANCE OF SUB VFR VSBYS/CIGS.
&&
.CLIMATE...
TEMPERATURES REMAIN VERY WARM MONDAY AND TUESDAY. MONDAYS RECORD
HIGH FOR BLUEFIELD WV IS 83 DEGREES AND IN BLACKSBURG VA IT IS 85
DEGREES. THESE ARE THE ONLY TWO LOCATIONS MONDAY WHERE HIGH
TEMPERATURES MAY TIE OR EXCEED THE CURRENT RECORD HIGH TEMPERATURE.
TEMPERATURES ARE EXPECTED TO BE EVEN WARMER ON TUESDAY ALLOWING ALL
CLIMATE STATIONS TO HAVE A SHOT AT BREAKING A RECORD. HERE ARE
THE CURRENT RECORD HIGH TEMPERATURES FOR TUESDAY:
MAY 13
ROA92 (2000)
LYH92 (1956)
DAN93 (2000)
BCB84 (2000)
BLF83 (2010)
LWB 84 (2000)
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...PC/WP
NEAR TERM...WP
SHORT TERM...NF
LONG TERM...PM
AVIATION...RCS/WP
CLIMATE...CF
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
718 AM EDT MON MAY 12 2014
.SYNOPSIS...
HIGH PRESSURE OFF THE SOUTHEAST COAST IS GOING TO KEEP OUR REGION
IN A INCREASINGLY HUMID AIRMASS. A SLOW MOVING FRONT ENTERS THE
REGION BY THURSDAY AND SLIDES EAST FRIDAY. A COOLER AIRMASS
FOLLOWS THIS FRONT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 700 AM EDT MONDAY...
FEW SHOWERS ACROSS GREENBRIER COUNTY WV THIS MORNING...OTHERWISE
MAINLY SEEING SOME AC/CI. UPDATES JUST REFLECT TRENDS IN TEMPS/SKY
COVER WITH ISOLATED POPS IN THE NW CWA.
PREVIOUS VALID DISCUSSION...
DESPITE INCREASING 5H HEIGHTS TODAY...WILL STILL SEE A COUPLE OF
EMBEDDED SHORTWAVES RIDE THE NRN CENTER OF THE HIGH ACROSS OUR AREA.
EARLY THIS MORNING...THERE IS A WEAK SHORTWAVE MOVING ACROSS WV
WITH TAIL END OF SHOWERS PUSHING EAST BETWEEN BKW-CRW BUT WEAKENING.
THE LATEST HRRR SHOWS THIS AREA MAYBE SCRAPING NRN GREENBRIER AND
BATH. OVERALL...SHOULD BE A DRY MORNING WITH PATCH FOG IN THE
VALLEYS/RIVER AREAS.
TODAY...THE SFC HIGH OFF THE COAST WILL CONTINUE TO KEEP MOISTURE
STREAMING NWD INTO THE CENTRAL APPALACHIANS. HEATING WILL LEAD TO
INSTABILITY AND OVERALL WEAK FORCING FAVORS SCATTERED SHOWERS AND
STORMS POPPING AROUND MIDDAY IN THE MTNS WITH STEERING FLOW TAKING
THEM EAST TO THE BLUE RIDGE AND FOOTHILLS DURING THE AFTERNOON.
FURTHER SOUTH ACROSS NC/SOUTHSIDE VA...AIRMASS MAY BE JUST CAPPED
ENOUGH TO LIMIT CONVECTION...ALTHOUGH A FEW SHOULD SKIRT BY THIS
EVENING WHEN CAP WEAKENS. OVERALL KEPT POPS UNDER HIGH CHANCE...BUT
WILL BE A CASE WHERE 1/3-1/2 OF A COUNTY GETS RAINED ON...WHILE THE
OTHER HALF MISSES OUT.
FOR HIGHS WILL SEE MOSTLY SUNNY SKIES EARLY WITH CU/TCU DEVELOPING
WITH SOME AC/CI OVERTOP. THIS WILL LIMIT HEATING MAINLY OVER THE
MOUNTAINS BUT STILL LOOKING AT TEMPS RUNNING AROUND 10 DEGREES ABOVE
NORMAL. HIGHS RANGING FROM THE UPPER 70S/LOWER 80S WEST TO NEAR 90
SOUTHEAST.
TONIGHT...CONVECTION WEAKENS WITH LOSS OF HEATING. THE 00Z WRF/NAM
HOLD ONTO ACTIVITY INTO LATE EVENING WHILE THE OTHER MODELS SHOWING
LITTLE TO NONE AFTER 00Z/8 PM. WILL LEAN TOWARD THE HIGHER RES
MODELS SINCE ANY OUTFLOW COULD KEEP A SHOWER/STORM GOING PAST 8 PM.
BY MIDNIGHT WILL BE CLEAR TO PARTLY CLOUDY AND HUMID WITH LOWS IN
THE UPPER 50S TO LOWER 60S. FOG COULD BECOME AN ISSUE SINCE RAIN
SHOWERS ARE EXPECTED THIS AFTERNOON...ALTHOUGH COVERAGE WILL BE
PATCHY.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/...
AS OF 415 AM EDT MONDAY...
UPPER LEVEL RIDGING WILL BE FIRMLY IN PLACE TUESDAY MORNING ACROSS
THE EASTERN SEABOARD...WHICH WILL RESULT IN VERY SUMMER LIKE
TEMPERATURES. EXPECT AFTERNOON HIGHS TO RANGE FROM THE LOW/MID 80S
ACROSS THE MOUNTAINS... TO THE LOW 90S ACROSS THE SOUTHSIDE. STRONG
HEATING AND CONTINUED MOISTURE INFLOW SHOULD HELP KICK OFF A FEW
SHOWERS AND THUNDERSTORMS DURING LATE AFTERNOON AND EARLY EVENING...
HOWEVER THE RIDGING WILL KEEP THIS ACTIVITY SPOTTY AT BEST AND
DISORGANIZED. WILL BE KEEPING AN EYE ON A COLD FRONT BACK DOORING
ITS WAY SOUTHWARD FROM NEW ENGLAND DURING THE AFTERNOON AND
EVENING...BUT DO NOT THINK IT WILL APPROACH CLOSE ENOUGH TO ENHANCE
CONVECTION OVER OUR AREA. AT ANY RATE...ANY CONVECTION SHOULD
GRADUALLY FIZZLE TOWARD SUNSET...AND PATCHY FOG WILL BE POSSIBLE
TUESDAY NIGHT...ESPECIALLY IN AREAS WHICH DO RECEIVE A DOWNPOUR.
BETTER CHANCES FOR SHOWER AND THUNDERSTORMS WILL OCCUR ON WEDNESDAY
AS UPPER LEVEL RIDGING BEGINS TO SHIFT EAST...WHILE THE BACK DOOR
FRONT STALLS ACROSS NORTHERN VIRGINIA JUST OUTSIDE OUR FORECAST
REGION. ANOTHER DAY OF STRONG HEATING AS HIGHS REACH INTO THE 80S
MOST LOCATIONS...COMBINED WITH LOW LEVEL CONVERGENCE ASSOCIATED WITH
THE NEARBY FRONT...WILL LEAD TO HIGHER RAIN CHANCES ACROSS THE
MOUNTAINS AND THE PIEDMONT NORTH OF HIGHWAY 460. THE INCREASED
INSTABILITY WILL ALLOW FOR GREATER POTENTIAL FOR ORGANIZED
THUNDERSTORM ACTIVITY...AND A FEW STORMS WILL LIKELY BECOME STRONG
DURING LATE AFTERNOON AND EARLY EVENING...CAPABLE OF PRODUCING
LOCALLY STRONG WINDS AND HAIL. WILL SEE THE BOUNDARY ACROSS NORTHERN
VIRGINIA LIFT TOWARD NEW ENGLAND DURING LATE EVENING AS A WARM
FRONT...WHILE A STRONG COLD FRONT APPROACHES OUR REGION FROM THE
WEST.
THE COLD FRONT WILL ENTER OUR WESTERN MOST COUNTIES DURING MID
AFTERNOON...RESULTING IN WAVES OF LOCALLY HEAVY RAIN AS UPPER LEVEL
DISTURBANCES PASS OVERHEAD ALONG THE BOUNDARY. MODELS ARE PICKING UP
ON AT LEAST ONE STRONG WAVE POTENTIALLY BRINGING HEAVY RAIN TO THE
FOOTHILLS AND THE PIEDMONT DURING THE EVENING...AND POSSIBLY A
SECOND WAVE IF THE COLD FRONT SLOWS/STALLS BEFORE EXITING OUR REGION
DURING EARLY FRIDAY MORNING. STILL NOT ENOUGH CONFIDENCE IN THE
MODELS TO TACK DOWN RAINFALL AMOUNTS...BUT IT IS LOOKING SAFE TO SAY
THAT THE MUCH OF THE REGION WILL RECEIVE BETWEEN ONE AND TWO INCHES
FOR THE THURSDAY AND EARLY FRIDAY TIME PERIOD...WITH SOME AREAS
PICKING IN EXCESS OF 3 INCHES...ESPECIALLY ALONG THE BLUE RIDGE.
MODELS ARE IN DECENT AGREEMENT THAT THE FRONT AND ASSOCIATED HEAVY
RAIN WILL BE EAST OF OUR AREA DURING EARLY FRIDAY AFTERNOON...
LEAVING ONLY RESIDUAL SHOWER ACTIVITY...AS WELL AS A SHARP DROP IN
TEMPERATURES AS A DEEP UPPER TROUGH APPROACHES FROM THE WEST.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 400 PM EDT SUNDAY...
AN AMPLIFIED MID-UPPER LEVEL MEAN TROUGH SETTLES OVER THE ERN HALF
OF THE CONUS FOR THE LATTER HALF OF THE WEEK AND INTO NEXT
WEEKEND.
AS WE TRANSITION INTO THE WEEKEND...FLOW BECOMES BLOCKY WITH A
DEEP QUASI-STATIONARY...ALMOST WINTERLIKE UPPER LOW PARKED OVER
THE GREAT LAKES REGION. 850MB TEMPS WILL DROP INTO THE 3C TO 6C
RANGE FOR MOST OF THE CWA AND LINGER IN THIS RANGE FOR SEVERAL
DAYS. SEVERAL SPOKES OF PVA ARE EXPECTED TO ROTATE AROUND THIS
UPPER LOW WHICH SUGGESTS POTENTIAL FOR CLOUDS AND SHOWERS...
ESPECIALLY ACROSS THE MOUNTAINS. TEMPERATURES WILL TREND TO THE
COOLER SIDE OF NORMAL. FORTUNATELY...CLOUDS...SHOWERS...AND A BIT
OF A NW BREEZE SHOULD MITIGATE FROST POTENTIAL. NONETHELESS...IT
WILL BE QUITE CHILLY WITH HIGHS IN THE 60S AND LOWS IN THE 40S
ACROSS MUCH OF THE REGION...A BIG CONTRAST FROM THE WARMTH THE
FIRST HALF OF THIS WEEK.
&&
.AVIATION /11Z MONDAY THROUGH FRIDAY/...
AS OF 710 AM EDT MONDAY...
NOT MUCH CHANGE FROM PREVIOUS TAFS. MODELS STILL SHOWING A
SCATTERING OF CONVECTION BETWEE 16-18Z TODAY OVER THE
MOUNTAINS...AND SKIRTING TOWARD LYH BY 20Z. STILL TOO LOOSE OF
COVERAGE TO HAVE ANYTHING MORE THAN VCTS IN THE TAFS ASIDE FROM
BLF. ASIDE FROM THE STORMS...EXPECT VFR.
THIS EVENING...CONVECTION WANES AND SKIES WILL BE CLEAR/PC AND
VFR. SOME MVFR VSBYS AND POSSIBLY LOWER OVERNIGHT. WILL HAVE TO
SEE WHERE IT RAINS THIS AFTERNOON WHICH CAN SET UP MORE FOG
OVERNIGHT. RIGHT NOW CONFIDENCE HIGH THAT AT LEAST THE CLIMO
FAVORED STATIONS OF LWB/BCB GET MVFR VSBYS OVERNIGHT.
FORECAST FAVORS SLOWING OF THE FRONT SO THAT NOW EVEN WEDNESDAY
COULD HAVE LESS COVERAGE. UNTIL THE FRONT GETS CLOSER EXPECT
MAINLY VFR WITH POP UP STORMS IN THE AFTERNOON...AND MAYBE FOG
ENTERING THE PICTURE MORE OVERNIGHT AT MOST SITES OUTSIDE OF
BLF/LWB.
HEAVY RAINS AND STORMS WILL BE AFFECTING OUR REGION BY THURSDAY
AND COULD LINGER INTO EARLY FRIDAY. SO DURING THE WED-FRI TIME
FRAME GOOD CHANCE OF SUB VFR VSBYS/CIGS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...PC/WP
NEAR TERM...WP
SHORT TERM...NF
LONG TERM...PM
AVIATION...RCS/WP
AREA FORECAST DISCUSSION
NWS PUEBLO CO
341 PM MDT MON MAY 12 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 340 PM MDT MON MAY 12 2014
...HEAVY SNOW CONTINUES FOR THE CONTINENTAL DIVIDE...WITH FREEZING
TEMPERATURES FOR THE SOUTHEAST PLAINS TONIGHT...
ENERGY DROPPING DOWN THE WEST SIDE OF THE UPPER TROF WILL KEEP SNOW
SHOWERS GOING ACROSS SOUTHERN AND WESTERN PORTIONS OF THE AREA.
LAPSE RATES ARE STEEP BENEATH THE UPPER TROF ALOFT..AND SNOW HAS
BEEN REALLY COMING DOWN IN WEB CAMS AT WOLF CREEK. VIS IS DOWN TO
1/4 MILE AS OF THIS LAST HOUR. ROADWAYS STILL LOOK CLEAR...BUT WITH
TEMPERATURES ALREADY IN THE 20S ACROSS THE HIGHER ELEVATIONS...IT
WOULD NOT TAKE MUCH MORE COOLING FOR SNOW TO BEGIN TO STICK.
NAM12...GFS...AND RAP ALL KEEP HEAVY SNOW CONTINUING THROUGH THE
OVERNIGHT HOURS...THOUGH MAJORITY WILL LIKELY FALL BEFORE MIDNIGHT.
FOR THAT REASON...UPGRADED THE WINTER WEATHER ADVISORIES FOR THE
HIGHER ELEVATIONS OF THE EASTERN SAN JUANS AND LA GARITAS TO A
WINTER STORM WARNING WITH AN EARLIER FORECAST PACKAGE UPDATE.
EASTERLY UPSLOPE FLOW INTO THE EASTERN SLOPES OF THESE RANGES WILL
ALSO LEAD TO FAIRLY HEALTHY SNOW AMOUNTS FOR THE WESTERN SIDE OF THE
SAN LUIS VALLEY. CDOT WEBCAM AT ANTONITO HAS SOME SNOW
FALLING...THOUGH MOST IS MELTING ON PAVEMENT SURFACES...AND WITH
TEMPERATURES STILL AROUND OR SLIGHTLY ABOVE FREEZING EXPECT THIS TO
CONTINUE. HAVE PUT UP A WINTER WEATHER ADVISORY FOR THE LOWER
ELEVATIONS OF THE EASTERN SAN JUANS AND LA GARITAS AS WELL AS THE
HIGHER AREAS OF THE SAWATCH RANGE. WARNING AREAS COULD PICK UP A
TOTAL OF 8 TO 16 INCHES...WITH 4 TO 8 INCHES FOR THE ADVISORY AREAS.
THE WESTERN SIDE OF THE SAN LUIS VALLEY COULD SEE ON THE ORDER OF
1 TO 4 INCHES...BUT WARM GROUND MAY LIMIT ACCUMULATIONS TO LESSER
AMOUNTS.
THE SANGRES AND WETS COULD ALSO PICK UP SOME ADDITIONAL
ACCUMULATIONS TONIGHT...WITH ANOTHER 1 TO 3 INCHES FOR THE LOWER
ELEVATIONS...AND 2 TO 5 INCHES FOR THE HIGHER PEAKS.
SNOW WILL WIND DOWN EARLY TOMORROW MORNING...SO HEADLINES WILL
EXPIRE AT 6 AM. MEANWHILE...SOUTHEAST PLAINS WILL SEE A WIDESPREAD
FREEZE TONIGHT...AND CURRENT FREEZE WARNING STILL LOOKS ON TRACK.
UPPER TROF AXIS WILL SHIFT EAST OF THE AREA ON TUESDAY...BUT WITH
LINGER MOISTURE AND INSTABILITY...EXPECT ANOTHER ROUND OF ISOLATED
TO SCATTERED SHOWERS ACROSS THE MOUNTAINS. TEMPERATURES WILL
REBOUND A FEW DEGREES OVER THOSE OF TODAY...BUT HIGHER MOUNTAINS
WILL STILL SEE PRECIPITATION IN THE FORM OF SNOW. ANY ACCUMULATIONS
SHOULD REMAIN LIGHT...WITH A SPOTTY 1-3 INCHES POSSIBLE. -KT
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 340 PM MDT MON MAY 12 2014
TUESDAY NIGHT THROUGH SATURDAY...LONG RANGE MODELS INDICATE THAT THE
UPPER SYSTEM WILL PARK OVER THE MIDWEST THROUGH MUCH OF THE WORK
WEEK...KEEPING COLORADO UNDER NW FLOW ALOFT. THIS FLOW IS A COOLER
ONE...SO THE WARM UP FOR THE FORECAST AREA IS EXPECTED TO BE SLOWER
UNTIL THE UPPER PATTERN SHIFTS. THE UPPER RIDGE TO THE WEST IS
FORECAST TO FINALLY FLATTEN AND SLIDE ACROSS THE STATE ON SAT. THIS
TRANSLATES TO ANOTHER THREAT OF FREEZING TEMPS FOR THE PLAINS TUE
NIGHT...THEN HIGH TEMPS ON WED IN THE 50S AND 60S. TEMPS GRADUALLY
WARM THU THROUGH SAT WITH MAX TEMPS IN THE 70S FOR THE PLAINS...AND
IN THE 60S FOR THE HIGH VALLEYS. EXTENDED MODELS ALSO HINT AT MORE
OF A SUMMERTIME PATTERN WHEN IT COMES TO CONVECTION...WITH AN
ISOLATED THREAT FOR SHOWERS AND STORMS OVER THE MTS EACH AFTN AND
EARLY EVE THROUGH SAT.
SUNDAY AND MONDAY...A LARGE UPPER TROUGH OF LOW PRESSURE MOVES
ONSHORE ACROSS THE WEST COAST LATE SAT...PRODUCING INCREASING SW
FLOW ALOFT FOR THE DESERT SW. LOOK FOR DRY AND VERY WARM CONDITIONS
FOR THE FORECAST AREA BOTH SUN AND MON...WITH MAX TEMPS IN THE 80S
FOR THE E PLAINS...AND IN THE 60S AND 70S FOR THE HIGH VALLEYS.
MOORE
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 340 PM MDT MON MAY 12 2014
VFR CIGS EXPECTED AT KCOS AND KPUB...THOUGH KCOS COULD
SEE A BRIEF DIP TO MVFR AS SHOWERS DROP DOWN OUT OF THE NORTH AND
CLIP BY THE TERMINAL. NORTH WINDS OFF THE PALMER DIVIDE SHOULD
PREVENT FOG FORMATION TOWARDS MORNING...THOUGH SOME MVFR STRATUS
WILL BE POSSIBLE AT TIMES TUESDAY MORNING. KALS WILL SEE THE BEST
CHANCE FOR SNOW SHOWERS...THOUGH ACCUMULATIONS AT THE TERMINAL
SHOULD REMAIN AROUND AN INCH OR LESS...MAINLY ON GRASSY SURFACES.
VFR CONDITIONS ARE EXPECTED ALL THREE TERMINALS TUESDAY AFTERNOON.
-KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
FREEZE WARNING FROM MIDNIGHT TONIGHT TO 8 AM MDT TUESDAY FOR
COZ083>089-093>099.
WINTER WEATHER ADVISORY UNTIL 6 AM MDT TUESDAY FOR COZ060-064-
067.
WINTER STORM WARNING UNTIL 6 AM MDT TUESDAY FOR COZ066-068.
&&
$$
SHORT TERM...KT
LONG TERM...MOORE
AVIATION...KT
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1217 PM MDT MON MAY 12 2014
.UPDATE...
ISSUED AT 1208 PM MDT MON MAY 12 2014
ANOTHER DISTURBANCE COMING DOWN THE BACK SIDE OF THE UPPER TROF
WILL KEEP SNOW GOING ALONG THE CONTINENTAL DIVIDE. NAM...GFS...AND
RAP ALL SUGGEST WARNING CRITERIA SNOWFALL WILL OCCUR ACROSS THE
HIGHER ELEVATIONS OF THE EASTERN SAN JUAN AND LA GARITAS WITH
ADVISORY SNOWFALL AMOUNTS FOR THE LOWER ELEVATIONS. THIS SEEMS
REASONABLE GIVEN THE FORCING AND INSTABILITY PRESENT. HAVE
UPGRADED THE WINTER WEATHER ADVISORIES TO WARNINGS FOR ZONES 66
AND 68...AND HOISTED ADVISORIES FOR THE LOWER ELEVATIONS OF THE
EASTERN SAN JUANS AND LA GARITAS...AS WELL AS THE HIGHER
ELEVATIONS OF THE SAWATCH RANGE. AS TEMPERATURES DROP INTO THIS
EVENING...EXPECT ROADWAYS WILL BECOME SLICK AND SNOW PACKED.
WESTERN PORTIONS OF THE SAN LUIS VALLEY COULD PICK UP 1 TO 4
INCHES OF SNOW WITH EASTERLY UPSLOPE FLOW IMPINGING ON THE HIGHER
TERRAIN...THOUGH SUSPECT THAT WARM GROUND WILL MELT SOME OF THIS
OFF AS IT FALLS THIS AFTERNOON...SO NO HIGHLIGHTS APPEAR NEEDED.
ANOTHER WAVE OF MODERATE TO HEAVY SNOW IS CURRENTLY FALLING
ACROSS THE EASTERN SLOPES OF THE WETS AND SANGRES THIS AFTERNOON.
HIGH RES HRRR WANES THIS OFF PRETTY QUICKLY THROUGH THE EARLY
AFTERNOON...SO WILL NOT HOIST ANY HIGHLIGHTS JUST YET...BUT WILL
MONITOR THESE AREAS CLOSELY. -KT
UPDATE ISSUED AT 905 AM MDT MON MAY 12 2014
ANOTHER BAND OF SNOW IS MOVING INTO NORTHERN EL PASO AND TELLER
COUNTIES THIS MORNING. ALTHOUGH ADDITIONAL SNOWFALL AMOUNTS WILL
REMAIN LIGHT (1-2 INCHES)...GUSTY WINDS AND POOR VISIBILITIES
WILL KEEP TRAVEL CONDITIONS POOR. HAVE OPTED TO ALLOW THE WINTER
STORM WARNINGS FOR TELLER AND NORTHERN EL PASO COUNTY TO
EXPIRE...BUT HAVE PUT UP A WINTER WEATHER ADVISORY UNTIL NOON TO
ACCOUNT FOR CONTINUING SNOWFALL AND POOR VISIBILITY. ALL OTHER
HIGHLIGHTS ASIDE FROM THE SOUTHWEST MOUNTAIN WINTER WEATHER
ADVISORY...HAVE EXPIRED AT 9 PM. -KT
UPDATE ISSUED AT 816 AM MDT MON MAY 12 2014
UPDATED TO TAKE DOWN FREEZE WARNINGS VALID FOR THIS MORNING.
HOWEVER...ANOTHER ROUND OF FREEZING TEMPERATURES IS EXPECTED
TONIGHT...AND FREEZE WARNINGS ARE ALREADY OUT. -KT
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM MDT MON MAY 12 2014
...MAIN CONCERNS INCLUDE UNSEASONABLY COLD TEMPS FOR
TODAY...FREEZING TEMPS FOR PLAINS TONIGHT...AND SNOWS FOR THE SW
MTNS...
CURRENTLY...
WEATHER SYSTEM THAT HAS BROUGHT BENEFICIAL PRECIP TO THE REGION
(ALONG WITH LATE SEASON SNOW) IS GRADUALLY WINDING DOWN OVER A GOOD
PART OF THE REGION. MOST PRECIP OVER THE PLAINS IS DECREASING AT 3
AM WITH A SOME PRECIP STILL NOTED GENERALLY N OF HIGHWAY 50. PRECIP
WAS STILL OCCURRING OVER THE MTNS AS PER RADAR...SFC OBS AND WEB
CAMS. SAT PIX AND MOSAIC RADAR IMGY STILL SHOWS LOW SPINNING OVER
THE CO REGION WITH 1 WELL DEFINED VORT CENTER OVER NC CO WHILE THE
MAIN LOW WAS STILL BACK OVER THE 4 CORNERS REGION.
TODAY...
PRECIP OVER THE PLAINS WILL CONTINUE TO DECREASE AND EXPECT MOST IF
NOT ALL OF IT TO BE OVER WITH BY MID TO LATE MORNING. ONLY EXCEPTION
WILL BE OVER THE PALMER DVD WHERE SHOWERS MAY LINGER INTO EARLY
AFTERNOON GIVEN THE STRONG NORTHERLY FLOW.
MAIN AREA OF PRECIP WILL BE OVER THE GREATER SAN JUAN REGION. TROUGH
IS GOING TO HOLD BACK OVER THIS AREA TODAY AND TONIGHT...AND FLOW AT
700 MB BECOMES EASTERLY OVER THE S CENTRAL CO REGION. THIS FLOW
COMBINED WITH FAVORABLE LAPSE RATES AND QG FORCING SHOULD ALLOW FOR
SEVERAL MORE INCHES OF SNOW FOR THE HIGHER ELEVATIONS OF THE SAN
JUANS...ALONG WITH LOWER ELEVATION RAIN/SNOW SHOWERS. FOR THIS
REASON I EXTENDED THE WINTER WX ADVISORIES FOR THE SAN JUAN REGION.
IT IS QUITE POSSIBLE THAT WARNING CRITERIA MAY OCCUR GIVEN THE
CONVECTIVE NATURE OF THE SNOW THAT WILL OCCUR TODAY.
IT IS GOING TO BE QUITE COOL TODAY OVER THE REGION AND MAX TEMPS
WILL RANGE 25 TO 30F DEGREES BELOW NORMAL. HIGHS WILL ONLY BE MAINLY
IN THE 40S OVER THE PLAINS WITH A 50 OR TWO OVER THE FAR E PLAINS.
TEMPS OVER THE PALMER DIVIDE WILL BE IN THE 30S. WE MAY SEE A MINIMUM
MAX TEMP RECORD TODAY FOR AREAS OF THE PLAINS. GIVEN THE GUSTY NNW
WINDS IT WILL EVEN FEEL COLDER. IN A NUTSHELL...IT WILL FEEL MORE
LIKE MARCH THAN MID MAY. DRESS APPROPRIATELY.
TONIGHT...
FREEZE WARNINGS HAVE BEEN ISSUED FOR THE ENTIRE PLAINS. TEMPS ALONG
THE LOWER ARK RVR VALLEY WILL GENERALLY BE AT OR AROUND 32 WITH
TEMPS ON THE PALMER DVD AND RATON MESA IN THE 25 TO 30F DEGREE
RANGE.
SNOW WILL CONTINUE OVER THE SAN JUANS THIS EVENING BUT SHOULD
DECREASE IN INTENSITY AND COVERAGE DURING THE EARLY MORNING HOURS AS
THE LOW SHIFT EAST-SOUTHEAST INTO THE TX PHDL REGION. OVERALL...WE
COULD SEE 4-8 OF ADDITIONAL SNOW FOR THE SAN JUANS TODAY THROUGH
TONIGHT. /HODANISH
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 340 AM MDT MON MAY 12 2014
MODELS IN GOOD AGREEMENT THROUGH THE EXTENDED WITH A HIGHLY
AMPLIFIED PATTERN ACROSS THE REGION.
AN UPPER LEVEL STORM SYSTEM STRETCHING FROM THE NORTHERN PLAINS TO
THE DESERT SOUTHWEST WILL BEGIN TO SLOWLY MOVE EASTWARD ON
TUESDAY. A DISTURBANCE ALONG THE BACKSIDE OF THE MAIN TROUGH WILL
BE TRACKING SOUTH ACROSS THE CONTINENTAL DIVIDE TUESDAY MORNING
AND MOVE INTO NEW MEXICO BY TUESDAY AFTERNOON. MODELS ALL HAVE
WIDESPREAD LIGHT TO MODERATE SNOWFALL FOR ALL MOUNTAIN AREAS
TUESDAY MORNING. THE HEAVIEST SNOW WILL LIKELY FALL OVER THE SAN
JUAN RANGE WHERE AN ADDITIONAL 2 TO 4 INCHES OF SNOW ARE EXPECTED.
THE CENTRAL AND EASTERN MOUNTAINS WILL LIKELY SEE AN ADDITIONAL 1
TO 3 INCHES ON TUESDAY. ON THE PLAINS...EXPECT DRY AND BREEZY
CONDITIONS WITH COOL AFTERNOON HIGHS IN THE 50S. MODELS ALL HAVE
PRECIPITATION FOR THE MOUNTAINS COMING TO AN END BY TUESDAY
EVENING AS THE UPPER SYSTEM SHIFTS EAST...AND THE DISTURBANCE
EMBEDDED IN THE BACKSIDE FLOW IS SOUTH IN NEW MEXICO. OVERNIGHT
LOWS TUESDAY NIGHT INTO WEDNESDAY MORNING WILL ONCE AGAIN DROP
INTO THE UPPER 20S TO LOWER 30S. THOSE WITH SENSITIVE OUTDOOR
PLANTS SHOULD BRING THEM INDOORS.
THE PATTERN STALLS ON WEDNESDAY...WITH THE LARGE UPPER LEVEL
TROUGH FROM THE GREAT LAKES INTO THE SOUTHERN PLAINS...WHILE AN
UPPER LEVEL RIDGE BUILDS ALONG THE WEST COAST. THIS WILL PUT
SOUTHERN COLORADO UNDER BROAD AND PERSISTENT NORTHWESTERLY FLOW.
PRECIPITATION CHANCES WILL BE HIGHLY DEPENDENT ON EMBEDDED
DISTURBANCES IN THE NORTHWEST FLOW THROUGH AT LEAST FRIDAY.
PERIODS OF LIGHT SNOW WILL BE POSSIBLE ACROSS THE MOUNTAIN AREAS
EACH DAY. AS FOR THE PLAINS...MODELS REMAIN CONSISTENT WITH A
DISTURBANCE ON THURSDAY NIGHT INTO FRIDAY WHICH MAY BRING SHOWER
ACTIVITY TO AT LEAST THE FAR EASTERN PLAINS. COVERAGE AND
CONVECTIVE NATURE ARE HIGHLY UNCERTAIN FOR THE PLAINS AT THIS TIME
BUT THE POSSIBILITY IS THERE. TEMPERATURES WILL GRADUALLY WARM
WEDNESDAY THROUGH FRIDAY...WITH THE PLAINS REACHING THE 70S BY
THURSDAY AND FRIDAY.
THE PATTERN WILL BEGIN TO PROGRESS ON SATURDAY AS A STORM SYSTEM
OFF THE BRITISH COLUMBIA COAST MOVES ONSHORE. THIS WILL FORCE
THE UPPER RIDGE OVER COLORADO. EXPECT DRY CONDITIONS THROUGH THIS
PERIOD WITH MUCH WARMER TEMPERATURES. HIGHS ACROSS THE EASTERN
PLAINS WILL LIKELY REACH WELL INTO THE 80S WITH A FEW LOW 90S
POSSIBLE. MOZLEY
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1141 AM MDT MON MAY 12 2014
CIGS WILL REMAIN MVFR TO VFR THROUGH THE AFTERNOON AT THE TAF
SITES...THOUGH THERE IS THE POTENTIAL INTO THIS EVENING FOR KALS
TO DROP DOWN INTO THE IFR CATEGORY IN SNOW SHOWERS AND FOG. KCOS
WILL ALSO HAVE THE POTENTIAL FOR SOME STRATUS AND FOG TOWARDS
MORNING...THOUGH HAVE KEPT CIGS IN THE MVFR RANGE FOR NOW. WINDS
WILL REMAIN GUSTY OUT OF THE NORTH AT 20 TO 35 KTS FOR BOTH KCOS
AND KPUB THROUGH THE AFTERNOON BEFORE DECREASING OVERNIGHT. WINDS
AT KALS WILL REMAIN OUT OF THE EAST AT 10-15 KTS THROUGH THE
AFTERNOON. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
FREEZE WARNING FROM MIDNIGHT TONIGHT TO 8 AM MDT TUESDAY FOR
COZ083>089-093>099.
WINTER WEATHER ADVISORY UNTIL 6 AM MDT TUESDAY FOR COZ060-064-
067.
WINTER STORM WARNING UNTIL 6 AM MDT TUESDAY FOR COZ066-068.
&&
$$
UPDATE...KT
SHORT TERM...HODANISH
LONG TERM...MOZLEY
AVIATION...KT
AREA FORECAST DISCUSSION
NWS TAUNTON MA
305 PM EDT MON MAY 12 2014
.SYNOPSIS...
HIGH PRESSURE REMAINS IN CONTROL THROUGH TODAY THEN A BACK DOOR
COLD FRONT STARTS MOVING THROUGH THE REGION LATE TONIGHT INTO
TUESDAY. MARITIME HIGH PRESSURE WEDNESDAY PROVIDES BELOW AVERAGE
TEMPERATURES FOLLOWED BY A PERIOD OF UNSETTLED WEATHER THURSDAY
INTO THE WEEKEND. THE BEST CHANCE OF HEAVY RAIN AND POSSIBLE
THUNDERSTORMS IS EXPECTED FRIDAY NIGHT INTO SATURDAY.
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
2 PM UPDATE...
TEMPS NOW IN THE LOW TO MID 80S AT 2 PM ACROSS THE INTERIOR IN
RESPONSE TO DEEP BLYR MIXING WITH SURFACE WINDS WSW UP TO 20-25
MPH. AT THE COAST PGRAD WEAK ENOUGH TO SUPPORT A SSW WIND. HOWEVER
TEMPS AT THE SHORE STILL WARM WITH READINGS 75-80!
WATCHING AREA OF CLOUD DEVELOPMENT OVER PA WITH NOTICEABLE
CYCLONIC SWIRL AS LOW AMPLITUDE SHORT WAVE MOVES ACROSS THIS AREA.
THIS SHOWS UP NICELY ON THE SPC MESOANALYSIS ESPECIALLY AT H7. SHOWERS
TRYING TO DEVELOP BUT INSTABILITY IS LACKING...BOTH AT THE SURFACE
AND ALOFT. DEW PTS ACROSS SOUTHERN NEW ENGLAND REMAIN DRY WITH
VALUES IN THE U30S AND L40S. SOME INSTABILITY OVER SOUTHERN NJ
THAT MAY ADVECT NORTHEAST INTO NYC/LONG ISLAND. THUS ANY SHOWER
ACTIVITY SHOULD SLIDE ACROSS PA/NJ/NYC...PERHAPS CLIPPING
SOUTHWEST CT. THEREFORE EXPECTING SOUTHERN NEW ENGLAND TO REMAIN
DRY THRU THIS EVENING. PREVIOUS DISCUSSION BELOW.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
ANOTHER SPECTACULAR DAY IN PROGRESS WITH DEEP LAYER RIDGE OVER THE
EASTERN GREAT LAKES AND SURFACE HIGH SOUTH OF NEW ENGLAND. THIS
SETUP IS PROVIDING LARGE SCALE SUBSIDENCE OVER THE REGION ALONG
WITH LOW LEVEL WESTERLY FLOW. THUS ABUNDANT SUNSHINE PREVAILS
ALONG WITH COMFORTABLE HUMIDITY WITH DEW PTS IN THE 30S AND 40S.
UPSTREAM SOUNDING AT ALBANY NY SUPPORTS HIGHS AROUND 80F WITH 850
TEMPS OF +11C. HOWEVER WITH BLYR EXTENDING UP TO 700 MB ALONG WITH
WESTERLY BLYR WINDS HIGHS WILL CLIMB INTO THE M80S WITH A LOW
PROBABILITY OF A FEW SPOTS BRIEFLY GETTING INTO THE U80S! THUS
HAVE INCREASED HIGHS A TAD FROM PREVIOUS FORECAST.
THINK DRY WEATHER WILL PREVAIL TODAY DESPITE BACKDOOR FRONT
APPROACHING FROM MAINE. PREFRONTAL AIRMASS IS VERY DRY WITH DEW
PTS IN THE 30S AND 40S. THIS RESULTS IN VERY LITTLE TO ANY
AVAILABLE INSTABILITY. IN ADDITION AS BLYR DEEPENS WINDS BECOME
WEST AND LIMIT SURFACE CONVERGENCE. HENCE DRY WEATHER SHOULD
PREVAIL THRU SUNSET. THIS IS TYPICALLY THE CASE AHEAD OF BACKDOOR
FRONTS. IN ADDITION LATEST HRRR KEEPS SOUTHERN NEW ENGLAND DRY
THRU 23Z FOLLOWED BY A FEW POSSIBLE SHOWERS/TSTMS ZIPPING ACROSS
WESTERN CT THEREAFTER. HOWEVER THIS IS A VERY LOW PROB. OTHERWISE
PREVIOUS FORECAST IN GOOD SHAPE AND NO MAJOR CHANGES PLANNED.
&&
.SHORT TERM /7 PM THIS EVENING THROUGH TUESDAY NIGHT/...
TONIGHT...AN APPROACHING WARM FRONT WILL BE STALLED BY A LOW
PRESSURE MOVING EAST INTO MAINE. ONCE THIS LOW PRESSURE MOVES
QUICKLY EAST...A STRONG HIGH PRESSURE WILL START TO BUILD SOUTH
ACROSS NORTHERN NEW ENGLAND. THIS HIGH PRESSURE WILL PUSH A BACK
DOOR COLD FRONT INTO SOUTHERN NEW ENGLAND LATE TONIGHT INTO
TUESDAY. WILL CONTINUE THE CHANCE FOR SOME SHOWERS INTO PARTS OF
OUR REGION TONIGHT...AT LEAST UNTIL THE SUBSIDENCE BECOMES
DOMINANT. THERE IS STILL SOME QUESTION AS TO WHEN THIS OCCURS...
BUT THE LATEST THINKING IS IT MAY TAKE MOST OF THE NIGHT.
COOLER OVERNIGHT TEMPERATURES ARE EXPECTED AS WINDS SHIFT TO THE
NORTH AND NORTHEAST BEHIND THE BACK DOOR COLD FRONT.
TUESDAY...
BACK-DOOR COLD FRONT CONTINUES TO MOVE WEST AS A HIGH PRESSURE
BUILDS OVER THE GULF OF MAINE. IT WILL TURN UNSEASONABLY COOL
WITH ONSHORE FLOW OFF ROUGHLY UPPER 40S DEGREE WATER. LIKELY TO
BE FAIRLY CLOUDY WITH A LONG FETCH OF EASTERLY FLOW UNDERGOING
WEAK UPSLOPE AS OVERRUNNING REMAINS PREVALENT ALONG THE LOW- TO
MID- LEVEL FRONTAL BOUNDARY SITUATED ACROSS AND TO THE WEST OF
NEW ENGLAND. AS SUCH CANNOT COMPLETELY RULE OUT A STRAY SHOWER OR
TWO. HOWEVER...EXPECTING MAINLY DRY CONDITIONS.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
HIGHLIGHTS...
* DRY WEDNESDAY
* UNSETTLED THU INTO WEEKEND WITH POTENTIAL FOR HEAVY RAIN
* REMAINING COOL EARLY NEXT WEEK WITH SPOTTY SHOWERS
FAIRLY CONFIDENT ON EVOLVING LARGE SCALE PATTERN LATER THIS WEEK
AND THROUGH WEEKEND. BUILDING RIDGE OVER WEST COAST LEADS TO
DEEPENING FULL LATITUDE TROUGH OVER EASTERN STATES...WHICH
EVENTUALLY CLOSES ITSELF OFF OVER GREAT LAKES AS RIDGING PERSISTS
ACROSS NORTH ATLANTIC. RESULT IS PERSISTENT S/SE FLOW WHICH WILL
LEAD TO PERIODS OF AT LEAST ISOLATED OR SCATTERED SHOWERS.
RAINFALL SHOULD BECOME MORE WIDESPREAD AS SLOW MOVING FRONT
APPROACHES LATE FRI/SAT...WHEN LOCALLY HEAVY RAINFALL IS ALSO
POSSIBLE.
WED...
UPPER RIDGE BUILDS OVER NEW ENGLAND WHILE HIGH PRESSURE REMAINS
OFFSHORE. THIS SHOULD MAINTAIN DRY WEATHER WITH NEAR SEASONABLE
TEMPERATURES...ASIDE FROM IMMEDIATE COAST DUE TO ONSHORE FLOW.
THU INTO SAT...
MAY SEE FEW SHOWERS THU DUE MORE TO PROLONGED S FLOW AS OPPOSED TO
SLOW MOVING COLD FRONT WHICH SHOULD STILL BE WELL TO OUR W. COULD
BE RATHER WARM/MUGGY DAY THU AS WEAK RIDGING STILL PREVAILS...
WHICH MAY ALLOW CLOUDS TO BREAK FOR A TIME.
ENSEMBLES AND 12Z MODELS SUGGEST MAIN WINDOW FOR MORE WIDESPREAD
SHOWERS/ISOLATED THUNDERSTORMS WILL BE LATE FRI INTO SAT MORNING
AS FRONT PUSHES THROUGH. DEEP S FLOW WITH UPPER LOW CLOSING OFF
ACROSS GREAT LAKES WILL BRING ANOMALOUSLY MOIST /+2 TO +3 SD/
AIRMASS INTO REGION ALONG WITH FAIRLY POTENT 850 MB JET. EARLY
INDICATIONS ARE FOR AS MUCH AS 1 TO 2 INCHES OF RAIN DURING THIS
TIME FRAME PER ENSEMBLE PROBABILITIES.
SUN AND MON...
DESPITE FRONT MOVING OFFSHORE...CLOSED UPPER LOW MEANS COOL/SHOWERY
PERIOD MAY BE IN STORE. 12Z GFS IS MOST AGGRESSIVE WITH THIS
FEATURE AS IT IS DAMPENED OUT IN ENSEMBLE MEANS.
&&
.AVIATION /19Z MONDAY THROUGH SATURDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH TUESDAY/...HIGH CONFIDENCE.
THRU 00Z...VFR WITH SSW WINDS ALONG THE COAST AND WSW INLAND
GUSTING UP TO 20 KT. DRY WEATHER PREVAILS WITH ANY SHOWERS/TSTMS
DEVELOPING OVER PA MOVING INTO NJ/NYC/LONG ISLAND AND OFFSHORE.
LOW PROBABILITY OF THIS ACTIVITY CLIPPING WESTERN CT.
AFTER 00Z...BACKDOOR FRONT FROM MAINE MOVES SOUTHWEST-WARD INTO
MA/RI/CT BEGINNING 01Z/02Z FIRST ACROSS NORTHEAST MA AND THEN
SOUTHWEST-WARD AS THE EVENING PROGRESSES. FRONT WILL COME THRU DRY
WITH ANY SHOWER ACTIVITY ACROSS THE LOWER HUDSON VALLEY OF
NY/NYC/LONG ISLAND...POSSIBLY CLIPPING CT.
TUE AND TUE NIGHT...VFR WITH MAINLY DRY WEATHER. ANY PRECIP WOULD
BE VERY LIGHT IN THE FORM OF SPRINKLES. NE WINDS TUE WITH GUSTS UP
TO 20 KT ALONG THE COAST...BECOME SE TUE NIGHT.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF. S WINDS BECOME SW AS THE
AFTERNOON PROGRESSES.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF.
OUTLOOK...WEDNESDAY THROUGH SATURDAY...
WEDNESDAY...HIGH CONFIDENCE.
VFR WITH POSSIBLE MVFR CIGS NEAR COAST.
THURSDAY...MODERATE CONFIDENCE.
MVFR IN SCT SHOWERS. IFR POSSIBLE NEAR COAST IN FOG/DRIZZLE.
FRIDAY INTO SATURDAY...MODERATE CONFIDENCE.
MVFR/IFR IN MORE WIDESPREAD SHOWERS AND ISOLATED TSTMS.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
HIGH CONFIDENCE THROUGH TUESDAY.
WINDS AND SEAS EXPECTED TO REMAIN BELOW SMALL CRAFT CRITERIA
THROUGH TODAY.
WINDS INCREASE AS A BACK DOOR COLD FRONT MOVES FROM NORTHEAST TO
SOUTHWEST TONIGHT. SMALL CRAFT ADVISORIES MAY AGAIN BE NECESSARY
FOR A TIME TONIGHT INTO TUESDAY...THOUGH SEAS LOOK TO REMAIN
BELOW 5 FEET. AT THIS POINT...DO NOT HAVE ENOUGH CONFIDENCE IN
REACHING 25 KT GUSTS OR 5 FOOT SEAS TO ISSUE SMALL CRAFT
ADVISORIES NOW. IT DOES REMAIN A POSSIBILITY...AND IS SOMETHING
FUTURE SHIFTS WILL HAVE TO CONSIDER.
OUTLOOK...WEDNESDAY THROUGH SATURDAY...
WEDNESDAY...HIGH CONFIDENCE.
HIGH PRESSURE REMAINS OFFSHORE WITH S/SE FLOW ACROSS WATERS.
INCREASING E SWELL BUT SHOULD STAY BELOW SCA. MAY SEE AREAS OF
FOG/DRIZZLE LATER IN DAY OR AT NIGHT.
THURSDAY INTO SATURDAY...MODERATE CONFIDENCE.
PERSISTENT S/SE WINDS SHOULD REMAIN BELOW 25 KT BUT SEAS WILL
SLOWLY BUILD THROUGH PERIOD...PROBABLY REACHING 5 TO 8 FT ON OUTER
WATERS. AREAS FOG SHOULD PREVAIL ALONG WITH AT LEAST SCATTERED
SHOWERS. BETTER CHANCE OF WIDESPREAD SHOWERS/FEW THUNDERSTORMS
LATE FRI INTO SAT AS SLOW MOVING COLD FRONT APPROACHES WATERS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...NOCERA/JWD
NEAR TERM...NOCERA
SHORT TERM...BELK
LONG TERM...JWD
AVIATION...NOCERA/JWD
MARINE...NOCERA/JWD
AREA FORECAST DISCUSSION
NWS TAUNTON MA
206 PM EDT MON MAY 12 2014
.SYNOPSIS...
HIGH PRESSURE REMAINS IN CONTROL THROUGH TODAY THEN A BACK DOOR
COLD FRONT STARTS MOVING THROUGH THE REGION LATE TONIGHT INTO
TUESDAY. MARITIME HIGH PRESSURE WEDNESDAY PROVIDES BELOW AVERAGE
TEMPERATURES FOLLOWED BY A PERIOD OF UNSETTLED WEATHER THURSDAY
THROUGH SATURDAY. BEST CHANCE OF HEAVY RAIN AND POSSIBLE
THUNDERSTORMS EXPECTED FRIDAY NIGHT INTO SATURDAY.
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
2 PM UPDATE...
TEMPS NOW IN THE LOW TO MID 80S AT 2 PM ACROSS THE INTERIOR IN
RESPONSE TO DEEP BLYR MIXING WITH SURFACE WINDS WSW UP TO 20-25
MPH. AT THE COAST PGRAD WEAK ENOUGH TO SUPPORT A SSW WIND. HOWEVER
TEMPS AT THE SHORE STILL WARM WITH READINGS 75-80!
WATCHING AREA OF CLOUD DEVELOPMENT OVER PA WITH NOTICEABLE
CYCLONIC SWIRL AS LOW AMPLITUDE SHORT WAVE MOVES ACROSS THIS AREA.
THIS SHOWS UP NICELY ON THE SPC MESOANALYSIS ESPECIALLY AT H7. SHOWERS
TRYING TO DEVELOP BUT INSTABILITY IS LACKING...BOTH AT THE SURFACE
AND ALOFT. DEW PTS ACROSS SOUTHERN NEW ENGLAND REMAIN DRY WITH
VALUES IN THE U30S AND L40S. SOME INSTABILITY OVER SOUTHERN NJ
THAT MAY ADVECT NORTHEAST INTO NYC/LONG ISLAND. THUS ANY SHOWER
ACTIVITY SHOULD SLIDE ACROSS PA/NJ/NYC...PERHAPS CLIPPING
SOUTHWEST CT. THEREFORE EXPECTING SOUTHERN NEW ENGLAND TO REMAIN
DRY THRU THIS EVENING. PREVIOUS DISCUSSION BELOW.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
ANOTHER SPECTACULAR DAY IN PROGRESS WITH DEEP LAYER RIDGE OVER THE
EASTERN GREAT LAKES AND SURFACE HIGH SOUTH OF NEW ENGLAND. THIS
SETUP IS PROVIDING LARGE SCALE SUBSIDENCE OVER THE REGION ALONG
WITH LOW LEVEL WESTERLY FLOW. THUS ABUNDANT SUNSHINE PREVAILS
ALONG WITH COMFORTABLE HUMIDITY WITH DEW PTS IN THE 30S AND 40S.
UPSTREAM SOUNDING AT ALBANY NY SUPPORTS HIGHS AROUND 80F WITH 850
TEMPS OF +11C. HOWEVER WITH BLYR EXTENDING UP TO 700 MB ALONG WITH
WESTERLY BLYR WINDS HIGHS WILL CLIMB INTO THE M80S WITH A LOW
PROBABILITY OF A FEW SPOTS BRIEFLY GETTING INTO THE U80S! THUS
HAVE INCREASED HIGHS A TAD FROM PREVIOUS FORECAST.
THINK DRY WEATHER WILL PREVAIL TODAY DESPITE BACKDOOR FRONT
APPROACHING FROM MAINE. PREFRONTAL AIRMASS IS VERY DRY WITH DEW
PTS IN THE 30S AND 40S. THIS RESULTS IN VERY LITTLE TO ANY
AVAILABLE INSTABILITY. IN ADDITION AS BLYR DEEPENS WINDS BECOME
WEST AND LIMIT SURFACE CONVERGENCE. HENCE DRY WEATHER SHOULD
PREVAIL THRU SUNSET. THIS IS TYPICALLY THE CASE AHEAD OF BACKDOOR
FRONTS. IN ADDITION LATEST HRRR KEEPS SOUTHERN NEW ENGLAND DRY
THRU 23Z FOLLOWED BY A FEW POSSIBLE SHOWERS/TSTMS ZIPPING ACROSS
WESTERN CT THEREAFTER. HOWEVER THIS IS A VERY LOW PROB. OTHERWISE
PREVIOUS FORECAST IN GOOD SHAPE AND NO MAJOR CHANGES PLANNED.
&&
.SHORT TERM /7 PM THIS EVENING THROUGH 6 PM TUESDAY/...
TONIGHT...AN APPROACHING WARM FRONT WILL BE STALLED BY A LOW
PRESSURE MOVING EAST INTO MAINE. ONCE THIS LOW PRESSURE MOVES
QUICKLY EAST...A STRONG HIGH PRESSURE WILL START TO BUILD SOUTH
ACROSS NORTHERN NEW ENGLAND. THIS HIGH PRESSURE WILL PUSH A BACK
DOOR COLD FRONT INTO SOUTHERN NEW ENGLAND LATE TONIGHT INTO
TUESDAY. WILL CONTINUE THE CHANCE FOR SOME SHOWERS INTO PARTS OF
OUR REGION TONIGHT...AT LEAST UNTIL THE SUBSIDENCE BECOMES
DOMINANT. THERE IS STILL SOME QUESTION AS TO WHEN THIS OCCURS...
BUT THE LATEST THINKING IS IT MAY TAKE MOST OF THE NIGHT.
COOLER OVERNIGHT TEMPERATURES ARE EXPECTED AS WINDS SHIFT TO THE
NORTH AND NORTHEAST BEHIND THE BACK DOOR COLD FRONT.
TUESDAY...
BACK-DOOR COLD FRONT CONTINUES TO MOVE WEST AS A HIGH PRESSURE
BUILDS OVER THE GULF OF MAINE. IT WILL TURN UNSEASONABLY COOL
WITH ONSHORE FLOW OFF ROUGHLY UPPER 40S DEGREE WATER. LIKELY TO
BE FAIRLY CLOUDY WITH A LONG FETCH OF EASTERLY FLOW UNDERGOING
WEAK UPSLOPE AS OVERRUNNING REMAINS PREVALENT ALONG THE LOW- TO
MID- LEVEL FRONTAL BOUNDARY SITUATED ACROSS AND TO THE WEST OF
NEW ENGLAND. AS SUCH CANNOT COMPLETELY RULE OUT A STRAY SHOWER OR
TWO. HOWEVER...EXPECTING MAINLY DRY CONDITIONS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
HIGHLIGHTS...
* HIGH PRESSURE ON WEDNESDAY WITH UNSEASONABLE TEMPS ALONG E COAST
* SEASONABLE TEMPS AND UNSETTLED WEATHER THURSDAY THROUGH THE WEEKEND
* POTENTIALLY TURNING CHILLY WITH SHOWERS INTO EARLY NEXT WEEK
MODELS AND CONFIDENCE...
LATEST 00Z GUIDANCE IS IN AGREEMENT SHOWING A STRONG WEST COAST
RIDGE WHICH WILL SUPPORT A BROAD/DEEP TROUGH SETTLING OVER THE ERN
HALF OF THE CONUS. CLOSER AT HOME...HIGH PRESSURE WILL BE BUILDING IN
THE GULF OF MAINE ON WEDNESDAY ALLOWING FOR DRY WEATHER. AS THE
TROUGH MOVES TOWARDS NEW ENGLAND...A NORTH ATLANTIC RIDGE WILL HOLD
STEADY...AND EVENTUALLY BLOCKS THE PROGRESSION OF THE TROUGH. A SFC
LOW PRES WILL INTENSIFIES OVER THE MID-ATLANTIC AS SEVERAL STRONG
SHORTWAVES DIG INTO THE BASE OF THE TROUGH. THAT LOW WILL THEN SLIDE
UP THE EAST COAST FRIDAY...AND DRAG A COLD FRONT ACROSS THE REGION
FRIDAY NIGHT INTO SATURDAY. STILL A LOT OF TIMING ISSUES WITH THIS
FORECAST BUT CONFIDENCE IS INCREASING THAT ASIDE FROM HIT OR MISS
SHOWERS IN THE MEDIUM RANGE...THE LONG TERM WILL BE VERY UNSETTLED
WITH POSSIBLE HEAVY RAIN/FLOODING ISSUES. SOLUTION SPREAD IS
GRADUALLY NARROWING BUT GFS/GEFS ARE CONTINUING LEADING HGT FALLS
INTO THE EAST FASTER THAN MOST OTHER GUIDANCE IN THE MID-LATE WEEK
TIME FRAME. ALTHOUGH LATEST EC GUIDANCE IS ON THE SLOWER SIDE OF THE
ENVELOPE WITH THE CMC ACTUALLY BEING IN THE MIDDLE OF THE SOLUTIONS
AND ENSEMBLES. TRENDS AND CONTINUITY OVER MULTIPLE DAYS HAVE BEEN
FAVORING SLOWER TIMING AS SUPPORTED BY THE AMPLIFIED NATURE OF THE
APPROACHING TROUGH AS WELL AS BLOCKY PATTERN IN THE ATLANTIC...WHICH
IS SUPPORTED WITH NAO TRENDING NEGATIVE. THEREFORE TRENDED THIS
FORECAST TOWARDS THE ENSEMBLES AS WELL AS WPC.
DETAILS...
WEDNESDAY...
HIGH PRESSURE WILL BUILD IN ACROSS THE GULF OF MAINE KEEPING MOST OF
THE REGION DRY. TEMPS WILL BE SEASONABLE EXCEPT ALONG THE EASTERN
COASTLINE AS ONSHORE FLOW WILL KEEP THE MARITIME AIR AROUND ON
WEDNESDAY. HOWEVER STALLED BOUNDARY ACROSS CENTRAL NY MAY ALLOW FOR
SOME ISO SHOWERS ACROSS WESTERN ZONES.
THURSDAY INTO SATURDAY...
STRONG ATLANTIC RIDGE TO THE EAST WILL SLOW THE PROGRESSION OF THE
DIGGING TROUGH AND STALL IT JUST WEST OF THE REGION. HOWEVER BY
THURSDAY...THE RIDGE WILL BREAK DOWN TEMPORARILY AS STRONG WESTERN
RIDGE PUSHES THE TROUGH TOWARDS THE NORTHEAST. EXPECT SEVERAL WEAK
WAVES TO DEVELOP AHEAD OF THIS TROUGH WHICH WILL APPROACH THE AREA.
HIT OR MISS SHOWERS/T-STORMS POSSIBLE ON THURSDAY WITH MORE
WIDESPREAD RAINFALL ON FRIDAY INTO SATURDAY. ALTHOUGH EXACT TIMING
OF EACH WAVE IS STILL UNCERTAIN...IT APPEARS THAT THE BEST CHANCE
FOR HIGHER PRECIP LOOKS TO BE FRIDAY NIGHT AS LOW PRESSURE SYSTEM
DEVELOPS ALONG THE FRONT. STRONG LLJ AND INCREASING MOISTURE
TRANSPORT SUPPORTS THE IDEA OF THE POSSIBILITY OF HEAVY RAINFALL.
ESPECIALLY SINCE THE TROUGH IS TAPPING INTO DEEP GULF MOISTURE
ALLOWING PWAT VALUES TO BE 3 STANDARD DEVIATIONS AWAY. INCREASING
CONFIDENCE THAT HEAVY RAINFALL WILL OCCUR BUT THERE IS STILL SOME
UNCERTAINTY ON EXACT TIMING...THEREFORE CONTINUED TO MENTION LIKELY
POPS FOR FRIDAY INTO SATURDAY. ALSO A LOW CONFIDENCE ON FLOODING
POTENTIAL AS FLASH FLOOD GUIDANCE IS APPROX 3 INCHES FOR MUCH OF THE
AREA. IN FACT WPC IS FORECASTING 2.5 INCHES OF QPF. SO IF THIS FRONT
STALLS/OR SLOWS DOWN ANY MORE WE MAY SEE SIGNIFICANT RAIN FALL
AMOUNTS NEAR FLASH FLOOD GUIDANCE.
A SEASONABLE BUT HUMID AIR MASS WILL OVERSPREAD THE REGION WITH SW
FLOW TAPPING INTO THE GULF...ADVECTING HIGHER DEWPOINTS AHEAD OF
THE TROUGH. FOG IS A POSSIBILITY ON WED NIGHT INTO THURSDAY AND
AGAIN ON FRIDAY. HIGHS WILL GENERALLY TOP OFF IN THE UPPER 60S TO
MID 70S WITH COOLER CONDITIONS ALONG THE COAST...ESP THE SOUTH COAST
DUE TO SOUTHERLY FLOW.
SUNDAY AND BEYOND...
MODELS DIFFER ON THE TIMING ON THE EXIT OF THE SYSTEM LATE SATURDAY
INTO SUNDAY. HAVE LOW CONFIDENCE ON WHEN THE FRONT WILL SWEEP
EASTWARD AS A SLIGHT CHANGE IN THE PATH COULD LEAD TO A SIGNIFICANT
CHANGE IN THE WEATHER FOR THE WEEKEND. OVERALL IT APPEARS THAT THE
STRONG ATLANTIC HIGH PRESSURE WILL STALL THE SYSTEM JUST EAST OF THE
REGION ON SUNDAY WITH AN UPPER LEVEL CUT OFF LOW FORMING. THIS LOW
WILL KEEP THE REGION SHOWERY AS WELL AS COOLER DUE TO THE COLD CORE
LOW WOBBLING OVER THE AREA.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH TUESDAY/...HIGH CONFIDENCE.
THRU 00Z...VFR WITH SSW WINDS ALONG THE COAST AND WSW INLAND
GUSTING UP TO 20 KT. DRY WEATHER PREVAILS WITH ANY SHOWERS/TSTMS
DEVELOPING OVER PA MOVING INTO NJ/NYC/LONG ISLAND AND OFFSHORE.
LOW PROBABILITY OF THIS ACTIVITY CLIPPING WESTERN CT.
AFTER 00Z...BACKDOOR FRONT FROM MAINE MOVES SOUTHWEST-WARD INTO
MA/RI/CT BEGINNING 01Z/02Z FIRST ACROSS NORTHEAST MA AND THEN
SOUTHWEST-WARD AS THE EVENING PROGRESSES. FRONT WILL COME THRU DRY
WITH ANY SHOWER ACTIVITY ACROSS THE LOWER HUDSON VALLEY OF
NY/NYC/LONG ISLAND...POSSIBLY CLIPPING CT.
TUE AND TUE NIGHT...VFR WITH MAINLY DRY WEATHER. ANY PRECIP WOULD
BE VERY LIGHT IN THE FORM OF SPRINKLES. NE WINDS TUE WITH GUSTS UP
TO 20 KT ALONG THE COAST...BECOME SE TUE NIGHT.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF. S WINDS BECOME SW AS THE
AFTERNOON PROGRESSES.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF.
OUTLOOK...WEDNESDAY THROUGH FRIDAY...
WEDNESDAY...HIGH CONFIDENCE. EASTERLY WINDS. VFR WITH POSSIBLE
MVFR CIGS ANTICIPATED. IFR OVERNIGHT IS POSSIBLE AS WINDS SWITCH
BACK TO THE SOUTH.
THURSDAY INTO FRIDAY...MODERATE CONFIDENCE.
VFR FOR THURSDAY. CONDITIONS DETERIORATING FRIDAY TO IFR WITH
INCREASING AREAL EXTENT OF SHRA AND POSSIBLE TSRA. SOUTHERLY WINDS
ON THURSDAY CONTINUING INTO FRIDAY WITH GUSTS UP AROUND 25-30 KTS
POSSIBLE.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
HIGH CONFIDENCE THROUGH TUESDAY.
WINDS AND SEAS EXPECTED TO REMAIN BELOW SMALL CRAFT CRITERIA
THROUGH TODAY.
WINDS INCREASE AS A BACK DOOR COLD FRONT MOVES FROM NORTHEAST TO
SOUTHWEST TONIGHT. SMALL CRAFT ADVISORIES MAY AGAIN BE NECESSARY
FOR A TIME TONIGHT INTO TUESDAY...THOUGH SEAS LOOK TO REMAIN
BELOW 5 FEET. AT THIS POINT...DO NOT HAVE ENOUGH CONFIDENCE IN
REACHING 25 KT GUSTS OR 5 FOOT SEAS TO ISSUE SMALL CRAFT
ADVISORIES NOW. IT DOES REMAIN A POSSIBILITY...AND IS SOMETHING
FUTURE SHIFTS WILL HAVE TO CONSIDER.
OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...
TUESDAY NIGHT INTO WEDNESDAY...MODERATE CONFIDENCE.
HIGH PRESSURE WILL BUILD OVER THE EASTERN WATERS TUESDAY NIGHT
AND INTO WEDNESDAY. EXPECT EASTERLY WINDS TO CONTINUE...ALLOWING
FOR EASTERLY SWELL TO BUILD. FOG AND DRIZZLE POSSIBLE BY LATE
WEDNESDAY AS FLOW SWITCH TO THE SOUTH. SCA MAY BE NEEDED FOR THE
PERIOD.
THURSDAY INTO FRIDAY...LOW CONFIDENCE.
LINGER 5FT SEAS TO START INCREASING THROUGHOUT THE DAY WITH THE
POSSIBILITY FOR A FEW SHOWERS ON THURSDAY. CONDITIONS DETERIORATE
ON FRIDAY AS FRONT APPROACHES THE WATERS. SEAS AND WINDS WILL
BUILD IN RESPONSE AS WELL AS HEAVY DOWNPOURS AND ISO THUNDER. SCA
WILL BE NEEDED.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...BELK/DUNTEN
NEAR TERM...NOCERA
SHORT TERM...BELK
LONG TERM...DUNTEN
AVIATION...NOCERA/DUNTEN
MARINE...BELK/DUNTEN
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
147 PM EDT MON MAY 12 2014
.PREV DISCUSSION...
UPDATE...
/ISSUED 1046 AM EDT MON MAY 12 2014/
HI RES MODELS ARE STILL IN GOOD AGREEMENT WITH ISOLATED TO
SCATTERED SHOWER AND THUNDERSTORM DEVELOPMENT THIS AFTERNOON BUT
SOME DIFFERENCES IN TIMING. HRRR IS QUICKER WITH INITIALIZATION
THAN THE LOCAL WRF...16Z COMPARED TO ABOUT 20Z. OVERALL THE
POP FORECAST IS ON TRACK AND DID NOT ADJUST THE SLIGHT
CHANCE/CHANCE FOR THIS AFTERNOON. I DID HOWEVER END UP PUSHING
BACK THE INITIATION TO 17Z. FORECAST DEW POINTS WERE A LITTLE ON
THE LOW SIDE SO INCREASED THEM INTO THE AFTERNOON.
11
SHORT TERM /TODAY THROUGH TUESDAY/...
WEAK UPPER-LEVEL RIDGING CONTINUES OVER THE REGION TODAY...THEN
BEGINS SHIFTING EAST INTO THE WESTERN ATLANTIC TUESDAY. THE RIDGE
DOES NOT APPEAR TO BE DOMINANT ENOUGH TO SHUT OFF ALL CHANCES FOR
CONVECTION BUT SHOULD LIMIT COVERAGE TO SCATTERED AT BEST AND
DIURNALLY ORIENTED. MID-LEVEL LAPSE RATES AROUND 6DEGC/KM OR LESS
KEEP INSTABILITY LIMITED WITH ANY THUNDERSTORMS EXPECTED TO REMAIN
BELOW SEVERE LIMITS.
FOR EARLY THIS MORNING...LOW-LEVEL MOISTURE AND MOIST SOILS ONCE
AGAIN CONTRIBUTING TO AREAS OF FOG WITH PATCHY AREAS OF DENSE FOG.
COVERAGE IS LESS THAN YESTERDAY MORNING AND IS EXPECTED TO REMAIN SO
THIS MORNING AND IT DOES NOT APPEAR THAT THE AREAL COVERAGE OF
VISIBILITIES BELOW 1/4 MILE WOULD BE SUFFICIENT FOR A DENSE FOG
ADVISORY.
20
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
LARGE HIGH AMPLITUDE H5 TROUGH OVER CENTRAL US FCST TO CONTINUE
PROGRESSING SLOWLY EASTWARD REST OF THE WEEK. BY 12Z WED...TROUGH
AXIS WILL STILL BE CENTERED ALONG 90W LONGITUDE BUT SWLY FLOW
ALOFT AND WARM/MOIST ADVECTION AHEAD OF IT WILL INCREASE ACROSS
THE SE STATES BRINGING CLOUDS AND SOME SCT SHRA WITH IT.
INSTABILITY QUITE HIGH OVER THE CENTRAL STATES. HOWEVER AS THE
TROUGH PUSHES EAST EACH DAY...LOW LEVEL FLOW PROGGED TO WEAKEN AND
INSTABILITY DECREASES SOME. BY 12Z THURSDAY WHEN THE FRONT
ASSOCIATED WITH THE UPPER TROUGH MOVES INTO THE STATE...MLCAPE
VALUES ONLY AROUND 250-500 J/KG AND 0-1KM BULK SHEAR ONLY
10-20KTS. COULD ALSO SEE UPSTREAM CONVECTION ALONG THE CENTRAL
GULF COAST AGAIN INHIBIT STORM DEVELOPMENT INLAND. DEEP SHEAR
PROGGED TO REMAIN QUITE STRONG WITH 0-6KM BULK SHEAR 12Z THUR
40-50KTS...INDICATIVE OF STRONG TEMP GRADIENT ALONG FRONT AS WELL.
EVEN WITH STRONG DEEP SHEAR...WITH LACK OF INSTABILITY AND LOW
LEVEL SHEAR...SVR STORMS APPEAR UNLIKELY AT THIS TIME. COULD SEE
PERIOD OF MDT TO HEAVY RAIN ON THURS...BUT WITH SLOW PROGRESSIVE
NATURE OF SYSTEM...APPEARS ANY ONE AREA SHOULD NOT SEE MORE THAN
2 INCHES THROUGH 12Z FRI.
AFTER FRONT AND ASSOCD SHORT WAVE PUSH THROUGH...UPPER TROUGH SLOW
TO PUSH OUT OF EASTERN CONUS. ANOTHER WAVE IN NW FLOW OVER THE
CENTRAL PLAINS PROGGED TO MOVE INTO THE TN VALLEY SAT. QUITE A BIT
OF DISCREPANCY BETWEEN MED RANGE MODELS /00Z GFS...ECMWF AND CMC/
ON THIS FEATURE...ECMWF SOMEWHAT SLOWER. WITH DRY AIR MASS EXPECTED
AS THIS SECOND WAVE APPROACHES...HAVE BACKED OFF A LITTLE ON POPS.
NW FLOW CAN BE TRICKY IN THE WARM SEASON SO WILL NEED TO MONITOR
THIS. INSTABILITY PROGGED TO BE LOW BUT NOT ZERO.
SNELSON
&&
.AVIATION...
18Z UPDATE...
WINDS WILL REMAIN SOUTHERLY THROUGH THIS EVENING AND WILL BE VRB
AROUND SOUTH. OVERALL THOUGH...TREND SHOULD BE TOWARDS SSW THIS
AFTERNOON AND TRANSITION TO SSE THIS EVENING. POP UP SHOWERS ARE
DEVELOPING ACROSS THE AREA. FOR THE MOST PART...AM HANDLING THIS
WITH A TEMPO SHRA FOR THE BEST TIMING /18-23Z RANGE/. THERE IS A
CHANCE OF TS BUT NOT HIGH ENOUGH AT THIS POINT TO MENTION IN THE
TAFS.
//ATL CONFIDENCE...18Z UPDATE...
LOW CONFIDENCE ON WIND DIRECTION DUE TO VARIABILITY AROUND SOUTH.
HIGH CONFIDENCE ON CIGS. HIGH CONFIDENCE ON VSBYS EXCEPT MEDIUM
DURING THE MORNING. MEDIUM CONFIDENCE ON SHRA OCCURRING AT THE
AIRPORT.
11
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 89 65 88 64 / 30 20 20 20
ATLANTA 87 68 86 66 / 30 20 20 20
BLAIRSVILLE 84 61 83 62 / 30 20 30 20
CARTERSVILLE 87 63 86 65 / 30 20 20 20
COLUMBUS 91 68 90 67 / 30 20 20 10
GAINESVILLE 85 66 84 65 / 30 20 20 20
MACON 90 65 89 65 / 30 20 20 10
ROME 87 63 86 63 / 30 20 30 20
PEACHTREE CITY 89 64 88 63 / 30 20 20 20
VIDALIA 90 67 89 68 / 30 20 20 10
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...11
LONG TERM....NLISTEMAA
AVIATION...11
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
321 PM CDT MON MAY 12 2014
.MESOSCALE DISCUSSION...
150 PM CDT
THE OVERALL COVERAGE OF CONVECTION LOOKS TO BE LOW THROUGH MID
AFTERNOON. THE MESOSCALE CONVECTIVE SYSTEM /MCS/ THAT TRACKED
ACROSS SOUTHERN WISCONSIN EARLIER HAS PLACED AN OUTFLOW BOUNDARY
OUT TO ITS SOUTH...WHICH IS LOCATED JUST NORTH OF THE IL/WI STATE
LINE. WEAK TO MODERATE CONVERGENCE EXISTS ALONG THIS BOUNDARY
THANKS TO THE MODEST SOUTH-SOUTHWEST FLOW WITHIN THE WARM SECTOR.
THIS WOULD BE ONE AREA FOR POSSIBLE REDEVELOPMENT WITH STORMS
LIKELY MOVING EAST-NORTHEAST IF THEY CAN SPARK. FURTHER TO THE
SOUTH...OUTFLOW FROM THE EARLIER MCS ACROSS EASTERN IA HAS
PROGRESSED EASTWARD WITH SOME OCCASIONAL MORE AGITATED CU SEEN
FROM MORRIS/PERU AREAS SOUTHWESTWARD NEAR PEORIA. OVERALL THOUGH
THE CU HAS APPEARED FAIRLY FLAT OVER A LOT OF THE AREA. SO
DEVELOPMENT CONFIDENCE ALONG THIS EARLIER OUTFLOW BOUNDARY IS LOW.
IT IS LOW CONFIDENCE THAT ANY SEVERE STORMS...AND EVEN POSSIBLY
MUCH FOR STORMS ACROSS CHICAGO...WILL DEVELOP OVER A GOOD PORTION
OF THE CURRENT WATCH THROUGH 5 PM. WILL CONTINUE THE WATCH LOCALLY
HOWEVER BASED ON COLLABORATION WITH SPC AND WFO MKX. CONVECTION IS
ALSO POSSIBLE LATE IN THE DAY INTO THE EVE AND AS STORMS IN SEVERE
THUNDERSTORM WATCH 150 IN EFFECT IMMEDIATELY TO THE WEST OF THE
AREA PROGRESS EAST. THAT COULD POSSIBLY RESULT IN A WATCH SOON
AFTER THE CURRENT ONE...NAMELY FOR NORTH CENTRAL ILLINOIS...SO DO
NOT WANT TO SEND ANY CONFUSING MESSAGES OF A WATCH CANCELLATION
THEN A RE-ISSUANCE.
MTF
&&
.DISCUSSION...
244 PM...MULTIPLE FORECAST CONCERNS AND CHALLENGES THROUGH THE
PERIOD INCLUDING THUNDERSTORM COVERAGE/TIMING THROUGH TUESDAY
AFTERNOON ALONG WITH SEVERE/HEAVY RAIN POTENTIAL. THEN TURNING
MUCH COLDER MIDWEEK WITH A PERIOD OF SHOWERS/RAIN FROM WEDNESDAY
EVENING INTO THURSDAY.
CONVECTIVE TRENDS OVER THE NEXT FEW HOURS DISCUSSED IN THE
ABOVE/RECENT MESOSCALE DISCUSSION WITH ATTENTION NOW SHIFTING TO
THUNDERSTORMS EXTENDING FROM CENTRAL IOWA SOUTH TO TEXAS...AHEAD
OF THE SLOWLY ADVANCING COLD FRONT. SHORT TERM GUIDANCE CONTINUES TO
SHOW ADDITIONAL ACTIVITY DEVELOPING AHEAD OF THE CURRENT LINE AS IT
ALL SLOWLY SHIFTS EAST...WHICH WOULD BRING ACTIVITY INTO THE WESTERN
CWA AS SOON AS 23Z-00Z. SEVERE POTENTIAL WOULD BE HIGHEST EARLIER
WITH BETTER INSTABILITY BEFORE LOST OF DAYTIME HEATING...THOUGH
TEMPS WILL ONLY SLOWLY DROP THROUGH THE 70S THIS EVENING. AS NOTED
IN THE PREVIOUS DISCUSSION...DO ANTICIPATE ANOTHER WATCH LATER THIS
EVENING BUT HOW FAR EAST AND COVERAGE OF SEVERE POTENTIAL WILL BE
TIED TO TIMING. MAIN THREATS WOULD CONTINUE TO BE LARGE HAIL AND
DAMAGING WIND GUSTS.
PRECIPITABLE WATER VALUES INCREASE TO 1.5 INCHES AND EVEN A BIT
HIGHER TONIGHT AND COMBINED WITH DEWPOINTS IN THE UPPER 60S AND
EVEN A FEW LOWER 70S...HEAVY RAIN IS LIKELY. WHILE THE INDIVIDUAL
STORMS WILL BE MOVING NORTHEAST FAIRLY QUICKLY...THE ENTIRE FRONTAL
PROGRESSION EASTWARD WILL BE RELATIVELY SLOW THUS HEAVY RAIN OVER
THE SAME AREAS COULD RESULT IN SOME FLOODING POTENTIAL. AND WITH THE
HEAVY RAINS IN PARTS OF THE AREA SUNDAY EVENING...INCLUDING THE
SOUTHERN SUBURBS AND NORTHWEST INDIANA...ADDITIONAL HEAVY RAIN COULD
LEAD TO LOCALIZED FLASH FLOODING. HOWEVER...CONFIDENCE IS SOMEWHAT
LOW WITH THE POTENTIAL FOR CONVECTION TO THE SOUTHWEST TO MOVE EAST
SOUTH OF THE AREA AND POTENTIALLY CUT OFF STRONGER/HEAVIER PRECIP
ACROSS NORTHERN IL.
PRECIP PROGRESSION EASTWARD WILL LIKELY SLOW TUESDAY MORNING AS IT
SLOWLY ENDS FROM WEST TO EAST BUT COULD CONTINUE INTO THE AFTERNOON
ACROSS NORTHWEST INDIANA. TEMP TRENDS WILL ALSO BE TRICKY AS THEY
WILL LIKELY FALL OR BECOME STEADY ACROSS THE EASTERN HALF WITH
SOME RECOVERY IN THE WEST IN THE AFTERNOON. TEMPS WILL CONTINUE TO
FALL INTO THE MID/UPPER 40S FOR LOWS BY WEDNESDAY MORNING AND
WHILE THESE ARE CLOSE TO NORMAL FOR MID MAY...IT WILL LIKELY FEEL
MUCH COLDER GIVEN THE CURRENT TEMPS AND DEWPOINTS.
AS THE UPPER TROUGH DIGS ACROSS THE CENTRAL AND SOUTHERN PLAINS
WEDNESDAY INTO WEDNESDAY NIGHT...NEW LOW PRESSURE WILL DEVELOP OVER
THE OHIO VALLEY AND LIFT NORTHEAST ACROSS THE CENTRAL OR EASTERN
GREAT LAKES REGION ON THURSDAY. WHILE CONFIDENCE IS INCREASING IN
THE OVERALL TRENDS WITH THIS SYSTEM...ITS EXACT TRACK COULD STILL
HAVE LARGE IMPACTS ON THE SPECIFICS OF THE FORECAST. FIRST...THERE
WILL PROBABLY BE A SHARP PRECIP GRADIENT ON THE NORTHWEST SIDE OF
THIS SYSTEM...WHICH WILL LIKELY BE ACROSS THE WESTERN CWA. THE
CLOSER THE LOW TRACKS TO THE AREA...THE STRONGER THE NORTHERLY WINDS
WILL BE...ESPECIALLY ACROSS THE EASTERN CWA. BUT AS CLOUDS AND
SHOWERS SPREAD NORTH WEDNESDAY WITH A RATHER COLD/WET WEDNESDAY
NIGHT/THURSDAY MORNING. HIGHS WEDNESDAY AND THURSDAY LIKELY ONLY
IN THE 50S...THOUGH ANY SUNSHINE ESPECIALLY WESTERN AREAS COULD
PUSH TEMPS INTO THE 60S.
AS AN UPPER LOW DEVELOPS ACROSS THE NORTHERN LAKES REGION THURSDAY
AND SLOWLY DRIFTS EAST THIS WEEKEND...WEAK IMPULSES COULD HELP
TRIGGER AFTERNOON SHOWERS ON FRIDAY AND PERHAPS AGAIN ON SATURDAY
THOUGH COVERAGE SHOULD BE MAINLY ISOLATED. TEMPERATURES WILL START
A SLOW WARMING TREND THROUGH THE 60S THIS WEEKEND AND PERHAPS
BACK INTO THE 70S EARLY NEXT WEEK. CMS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* SSWLY TO SWLY WINDS TO 25KT THIS AFTERNOON AND EVENING OUTSIDE
OF THUNDERSTORMS.
* TIMING AND CHANCES OF ADDITIONAL TSRA THIS AFTERNOON AND TONIGHT.
* OCNL MVFR CIGS THIS AFTERNOON AND TONIGHT.
KREIN
//DISCUSSION...UPDATED 18Z...
MAIN CONCERN CONTINUES TO BE THE CHANCES FOR THUNDERSTORMS THIS
AFTERNOON AND TONIGHT...UNTIL A COLD FRONTAL PASSAGE TOMORROW
MORNING.
THE ENVIRONMENT OVER THE AREA IS WARM AND MOIST WITH TEMPERATURES
IN THE 80S AND DEWPOINTS IN UPPER 60S. OLD OUTFLOW BOUNDARIES FROM
EARLIER CONVECTIVE ACTIVITY CAN PROVIDE THE FOCUS FOR ADDITIONAL
THUNDERSTORM DEVELOPMENT...BUT TIMING IS VERY UNCERTAIN AND
RESIDUAL CLOUD COVER MAY BE A LIMITING FACTOR FOR THE NEXT FEW
HOURS AS BOTH CI AND LOWER STRATOCU ARE FILTERING TH SUNSHINE.
ANTICIPATE THAT CLOUD COVER SHOULD THIN WITH TIME AND IS THE TREND
IN THE LATEST SATELLITE IMAGERY...SO THERE WILL BE A CHANCE FOR
SCATTERED THUNDERSTORM DEVELOPMENT THROUGH THE AFTERNOON AND
EVENING. GIVEN THE TIMING AND COVERAGE UNCERTAINTIES...HAVE BACK
OFF TO JUST VCTS MENTION...UNTIL A MORE ORGANIZED FOCUSING
MECHANISM BECOMES APPARENT. HAVE MAINTAINED THE PROB30 MENTION FOR
THUNDER FOR THE LATE NIGHT TO EARLY MORNING HOURS...IN CONJUNCTION
WITH THE APPROACHING COLD FRONT. EXPECT THAT WINDS SHOULD SHIFT TO
WESTERLY FOLLOWING THE FROPA...WHILE REMAINING RELATIVELY BRISK
AND GUSTY.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM TO HIGH CONFIDENCE IN WIND FORECAST.
* MEDIUM CONFIDENCE IN CEILING TRENDS.
* LOW CONFIDENCE CONVECTIVE TIMING AND COVERAGE TODAY AND TONIGHT.
* MEDIUM TO HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
* TUESDAY NIGHT...VFR.
* WEDNESDAY...SLIGHT CHANCE OF PM SHRA.
* THURSDAY...CHANCE OF SHRA.
* FRIDAY...SLIGHT CHANCE OF SHRA.
* SATURDAY AND SUNDAY...DRY/VFR.
KJB
&&
.MARINE...
320 PM CDT
AREAS OF DENSE FOG CONTINUE TO PERSIST LATE THIS AFTERNOON ACROSS
NORTHERN LAKE MICHIGAN PER SHIP OBS AND SURROUNDING SFC COASTAL
OBS NORTH OF THE WARM FRONT DRAPED WEST TO EAST ACROSS THE MIDDLE
PART OF THE LAKE. THIS WARM FRONT EXTENDS BACK WEST TO LOW
PRESSURE OVER E CENTRAL MN / NORTHWEST WI WHICH WILL CONTINUE TO
MOVE NORTHEAST TONIGHT. THIS FRONTAL BOUNDARY WILL CONTINUE TO BE
A FOCUS FOR SHOWER AND THUNDERSTORM DEVELOPMENT TONIGHT AS WELL. A
COLD FRONT ASSOCIATED WITH THE LOW WILL SWEEP WEST TO EAST ACROSS
THE LAKE AROUND DAYBREAK TUESDAY SWEEPING OUT THE FOG AND
BRINGING ANOTHER CHANCE OF SHOWERS AND THUNDERSTORMS INTO THE
MORNING TUESDAY.
WINDS OCCASIONALLY EXCEEDING SMALL CRAFT ADVISORY THRESHOLDS WILL
CONTINUE INTO THIS EVENING ALONG THE ILLINOIS AND INDIANA
SHORELINES. ONGOING CONVECTION HAS DISRUPTED THE WIND FIELD
CAUSING AN ONSHORE LAKE BREEZE ESPECIALLY FARTHER NORTH CLOSER TO
THE OUTFLOW FROM EARLIER THUNDERSTORMS ACROSS WISCONSIN AND
CENTRAL LAKE MICHIGAN. AS THE SOUTHERLY GRADIENT REESTABLISHES
ITSELF... NEW SCATTERED THUNDERSTORMS MAY ALSO CAUSE HIGHER WINDS AND
WAVES INTO THE EVENING THROUGHOUT THE NEAR SHORE WATERS.
ED F
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM MONDAY.
DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565
UNTIL 1 AM TUESDAY.
&&
$$
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[top]
Area Forecast Discussion
National Weather Service Lincoln IL
254 PM CDT Mon May 12 2014
.DISCUSSION...
ISSUED 252 PM CDT Mon May 12 2014
Warm and rather humid day across the forecast area today, with dew
points in the upper 60s to around 70 degrees and temperatures
mostly in the 80s. Air mass over our area is uncapped and CAPE`s
are from 3500-4000 J/kg in central Illinois, but so far convection
in our CWA has been spotty. More widespread showers/storms have
been occurring across the Ohio Valley. Main action has been
filling in across Iowa and the northwest half of Missouri, along a
cold front.
SHORT TERM...Tonight through Thursday:
Initial forecast concern is on the severe weather potential the
next several hours. The individual storms to our west have been
moving northeast with the overall area only slowly shifting
eastward. The HRRR and NMM high-resolution models have that
particular band of storms reaching the Illinois River around 6 to
7 pm and the I-55 corridor around 9 to 10 pm. Surface observations
over the area are not showing any meaningful boundary currently
present, thus the popcorn nature of the showers/storms so far.
Infrared and water vapor imagery showing some anti-cyclonic motion
over our CWA, which could be causing enough sinking of the air to
keep the showers under control so far. 0-6km shear values expected
to remain rather modest in most areas, so am thinking that the
storms will remain rather disorganized but briefly severe until
the main line gets here. Loss of daytime heating should weaken the
line of storms somewhat as it moves through tonight, but CAPE`s
remain 1000-2000 J/kg ahead of the front so there will still be
some instability to work with.
Morning model runs have the front roughly along the Indiana border
by midday, with threat of thunder diminishing from west to east
through the day. Have kept the dry weather west of I-55 for the
afternoon with likely PoP`s across east central and southeast
Illinois continuing in the afternoon. Temperatures across the east
will be slowly falling in the afternoon behind the front.
Long-advertised phasing of upper troughs in the north central and
southwest U.S. will try to take place the next couple days, although
the models keep them somewhat distinct through mid week.
Development of a surface low will take place Tuesday night across
the lower Mississippi Valley, and this low will be ejected
northeast on the nose of a developing 90-110 knot jet. Dry
northeast flow will erode the northern fringes of the rain shield
some, so will continue to focus the higher PoP`s on Wednesday
across the southeast half of the forecast area. As the surface low
moves northeast, a large upper low will develop over the upper
Mississippi Valley, so the threat of showers will continue even
after the main precipitation shield exits. High temperatures both
Wednesday and Thursday only expected to be in the upper 50s to
around 60 most areas due to the cooler air aloft and the rain.
LONG TERM...Friday through Monday:
The cool and showery weather will continue into Friday, before the
upper low starts to lift into Ontario and the upper pattern over
the U.S. flattens out somewhat. A fast moving wave in the upper
flow tracks an area of rain southeast later in the weekend, with
the ECMWF model about 12-18 hours faster and a bit further north.
Have limited PoP`s on Saturday night and Sunday to slight chances
across the south half of the forecast area, but this may need to
be bumped up if these trends persist on the next couple model
runs. A more substantial warming trend will occur early next week,
as ridging occurs across the Plains.
Geelhart
&&
.AVIATION...
ISSUED 1253 PM CDT Mon May 12 2014
Main aviation concern during the 18z TAF period will be timing of
potential convection later this afternoon into tonight. Model
solutions are all over the place concerning convective initiation:
however, best forcing associated with cold front and other
mesoscale boundaries appears that it will stay west of the central
Illinois terminals until evening. HRRR tries to develop scattered
showers/storms west of I-55 between 20z and 23z, while NAM
continues to focus mainly on the evening hours. Will include VCTS
at all TAF sites from mid-afternoon on, but will not mention
predominant thunder until later. Based on NAM solution, will
include TSRA between 00z and 04z at KPIA, then further east to
KCMI between 05z and 09z. Once initial line of storms passes, a
period of light rain will likely linger along and just behind the
cold front overnight into early Tuesday morning. Forecast
soundings suggest MVFR ceilings with this precip. Winds will
initially be from the S/SW this afternoon, gusting to between 20
and 25kt at times. S/SW winds will continue through the evening
before veering to the W/NW after FROPA overnight. Winds will shift
to the W/NW at KPIA by 09z, then further east to KCMI by 15z.
Barnes
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1256 PM CDT MON MAY 12 2014
.DISCUSSION...
1056 AM CDT
A SEVERE THUNDERSTORM WATCH HAS BEEN ISSUED FOR FAR NORTHERN
ILLINOIS UNTIL 5 PM THAT COVERS BASICALLY THE INTERSTATE 88
CORRIDOR AND NORTHWARD. THIS INCLUDES ROCKFORD AND THE CITY OF
CHICAGO.
THE REALLY CHALLENGING FORECAST OF CONVECTIVE EVOLUTION CONTINUES
WITH A COUPLE REGIONAL COMPLEXES OF STORMS PROPAGATING EASTWARD AT
THE LEADING EDGE OF THE WARM AND MOIST LOW-LEVEL AIR. THE NORTHERN
ONE ACROSS SOUTHERN WI IS THE MORE ROBUST ONE AND FEEDING ON
BETTER UPPER AND MID-LEVEL SUPPORT. THE STORMS NEAR THE QUAD
CITIES HAVE SHOWN A GENERAL WEAKENING TREND. THE ORIENTATION OF
DEEP LAYER SHEAR VECTORS TO THESE COMPLEXES DO NOT INDICATE A
RAPID WIND THREAT DEVELOPING FROM THESE...HOWEVER THE OVERALL
CAPE/SHEAR SPECTRUM IS POTENTIALLY FAVORING SCATTERED SEVERE
STORMS TO DEVELOP THROUGH THE AFTERNOON.
THE 12Z RAOBS AT DVN AND ILX SOUNDING MODIFIED FOR FORECAST EARLY
AFTERNOON TEMPERATURES INDICATED INSTABILITY IN EXCESS OF 2000
J/KG IN THE MIXED LAYER...AND POTENTIALLY TOPPING 3500 J/KG. AS
THINNING OF HIGH CLOUDS CONTINUES OVER THE FORECAST
AREA...THIS HIGH DEGREE OF DESTABILIZATION SHOULD BE REALIZED.
WHILE EXACT EVOLUTION OF THESE COMPLEXES AS IT RELATES TO OUR
FORECAST AREA IS UNCERTAIN...AT LEAST SCATTERED CONVECTIVE
DEVELOPMENT IS BELIEVED TO BE PROBABLE FROM SURFACE AND/OR
ELEVATED OUTFLOW BOUNDARIES OVER FAR NORTHERN ILLINOIS.
CONVECTIVE ALLOWING MODELS CERTAINLY VARY IN THEIR SOLUTIONS...BUT
GENERALLY HAVE BEEN TRENDING WITH MORE AFTERNOON CONVECTION ACROSS
NORTHERN ILLINOIS. SO IT WAS THOUGHT BEST TO INCLUDE FAR NORTHERN
ILLINOIS IN THIS SEVERE THUNDERSTORM WATCH THROUGH THIS AFTERNOON.
THE PRIMARY HAZARDS WOULD BE WINDS AND LARGE HAIL...WITH MULTI-
CELL CLUSTERS THE FAVORED MODE.
MTF
//PREV DISCUSSION...
328 AM CDT
AMONG THIS MORNING`S MANY RECAST CHALLENGES ARE TEMPS
TODAY...PRECIP AND CONVECTIVE TRENDS THROUGH TONIGHT...RAIN CHANCES
LATER IN THE WEEK WITH SECONDARY CYCLONE...AND MAGNITUDE OF COLD AIR
MASS LATER THIS WEEK.
IT IS FUNNY HOW OFTEN CONFIDENCE IN A FORECAST DECREASES AS THE
FORECAST TIME NEARS. LAST NIGHT AT THIS TIME WAS FAIRLY CONFIDENT
THAT CONVECTION TO OUR WEST WOULD DISSIPATE BEFORE MAKING IT INTO
OUR AREA WITH THE FOCUS SHIFTING NORTH INTO WISCONSIN...BUT PLAYING
A GAME OF METEOROLOGICAL CHICKEN WITH THE MCS OVER IOWA THAT
CONTINUES TO CHARGE EAST TOWARD THE MISSISSIPPI RIVER EARLY THIS
MORNING AND AM GROWING INCREASINGLY TEMPTED TO FLINCH AND BUMP UP
POPS SOME THIS MORNING. THE ATMOSPHERE OVER NORTHERN ILLINOIS WAS
SIGNIFICANTLY MODIFIED AND STABILIZED BY SUNDAY EVENING`S
CONVECTION...BUT CONTRASTING THE 00Z SOUNDINGS FROM DVN AND ILX SHOW
JUST HOW NEARBY THE CONVECTIVELY MOIST AND UNSTABLE AIR MASS LIES.
THE COMPOSITE SECONDARY WARM FRONT/OUTFLOW BOUNDARY EXTENDING
ROUGHLY FROM KLAF TO JUST SOUTH OF THE QUAD CITIES IS LIFTING NORTH
AND/OR WASHING OUT WITH WINDS ACROSS NORTHERN ILLINOIS VEERING MORE
SOUTHERLY AND HIGHER DEWPOINTS CREEPING NORTHWARD.
SHORT RANGE GUIDANCE IS STRONGLY DIVIDED IN THE HANDLING OF THE MCS
OVER IOWA...WITH ONE CAMP SHOWING A FAIRLY RAPID DEMISE OVER THE
NEXT SEVERAL HOURS WITH ONLY SCTD SHRA/ISOLD TSRA POTENTIALLY MAKING
IT INTO NW CWA WHILE ANOTHER CAMP OF MODELS IS MORE AGGRESSIVE IN
BRINGING STORMS EAST ACROSS THE CWA THROUGH THE MORNING. THE
IMPLICATIONS OF HOW THIS SCENARIO EVOLVES ARE HUGE FOR
TEMPS...WINDS...AND SUBSEQUENT CONVECTIVE CHANCES WITH THE COLD
FRONT. CONFIDENCE IS NOT HIGH...BUT LEANING TOWARD STAYING THE
COURSE WITH THINKING FROM PREVIOUS FORECASTS WHICH SUGGEST A QUICK
WEAKENING TREND WITHOUT MUCH CONVECTION MAKING IT FAR INTO OUR CWA.
RECENT REGIONAL RADAR AND SATELLITE TRENDS SEEM TO FINALLY BE
SUPPORTING THIS LINE OF THINKING WITH CLOUD TOPS BEGINNING TO
QUICKLY WARM WITH DECREASING COVERAGE AND INTENSITY OF THE STORMS.
SEVERAL MODELS ARE HINTING AT THE POTENTIAL FOR ADDITIONAL SCTD
CONVECTION DEVELOPING IN THE WARM/MOIST/UNSTABLE AXIS EXTENDING FROM
DOWNSTATE IL NNE INTO NNW INDIANA. DESPITE LEANING TOWARD THE DRIER
SOLUTIONS FOR TODAY WILL BE MAINTAINING CHANCE POPS ACROSS THE CWA
TO ALLOW FOR EITHER THE IOWA MCS PERSISTING LONGER AND/OR
MOIST/UNSTABLE AXIS THIS AFTERNOON.
HIGH TEMPS AND EVEN GUSTINESS OF THE WINDS TODAY WILL HINGE ON CLOUD
COVER AND PRECIP. IF THE MCS CONTINUES TO QUICKLY WEAKEN AND DEBRIS
CLOUDINESS DISSIPATE...THEN IT SHOULD ALLOW FOR PARTIAL SUNSHINE AND
WHICH COULD SEND TIMES CLIMBING WELL INTO THE 80S AND ABOVE
OBJECTIVE GUIDANCE. THIS IS THE CURRENT FORECAST AND RATHER THAN
FLIP ONLY TO HAVE THE DAY SHIFT HAVE TO FLOP WILL STAY THE COURSE
WITH ABOVE GUIDANCE HIGHS AND IF IT BECOMES CLEAR THAT CLOUDS WILL
STICK AROUND THE DAY SHIFT CAN BACK OFF ON TEMPS WITH A MORNING
UPDATE. THERE ARE A HANDFUL OF CONVECTIVE ALLOWING MODELS SHOWING A
RELATIVE MIN IN CONVECTIVE REDEVELOPMENT OVER IOWA TONIGHT FOLLOWING
THE STABILIZING EFFECTS OF CURRENT MCS...BUT WITH GREATER NUMBER OF
MODELS SUPPORTING RE-DEVELOPMENT PLAN TO HANG ON TO LIKELY POPS
TONIGHT AS THE FRONT MOVES EAST TOWARD THE AREA. MORE MARGINAL AND
UNIDIRECTIONAL SHEAR PROFILES AND DECREASING INSTABILITY AT NIGHT
BOTH WOULD ARGUE FOR STORMS MOVING INTO THE AREA TONIGHT TO BE IN A
WEAKENING PHASE WITH SEVERE THREAT DECREASING WITH TIME AND EASTWARD
EXTENT TONIGHT.
RAIN COULD LINGER INTO TUESDAY...ESPECIALLY IN THE MORNING AND OVER
THE EASTERN CWA BEFORE BETTER FORCING PUSHES OFF TO THE EAST AND
DRIER AIR MOVES IN. TUESDAY AFTERNOON COULD BE SALVAGEABLE FOR MANY
AREAS WITH NEAR NORMAL HIGHS AND LIKELY AN END TO THE PRECIPITATION.
LATER WEDNESDAY INTO THURSDAY GUIDANCE REALLY RUNS THE GAMUT IN
HANDLING OF THE SECONDARY SHORTWAVE TROUGH ROUNDING THE BASE OF THE
DEEP UPPER TROUGH THAT WILL BECOME ESTABLISHED OVER EASTERN NOAM.
WPC PREFERRED MODEL CHOICE WAS THE 00Z ECMWF WHICH IS CLOSE TO THE
MIDDLE OF THE ROAD OF POSSIBLE SOLUTIONS AND SAW NO REASON TO
DEVIATE FROM THIS LINE OF THINKING. ASSUMING THE ECMWF VERIFIES A
SECONDARY WAVE OF LOW PRESSURE WILL TRACK NORTHEAST ALONG THE
PASSING COLD FRONT AND PRODUCE A PERIOD OF RAIN/SHOWERS...MAINLY
SOUTHEASTERN HALF OF THE CWA. REMARKABLY SOME GUIDANCE HAS 850MB
TEMPS DROPPING TO 0 TO -2C DURING THE PRECIP WHICH WHILE COLD IS
PROBABLY NOT COLD ENOUGH FOR ANY MIXED PRECIP GIVEN THE TIME YEAR
BUT PERILOUSLY CLOSE. GIVEN THE MODEL SPREAD EARLY IN THE PERIOD
PROBABLY NOT SURPRISING THAT THERE IS SUBSTANTIAL SPREAD IN THE
INTENSITY OF THE UPPER TROUGH/LOW LATE IN THE WEEK AND SUBSEQUENT
TEMPS WITH FAR MORE AMPLIFIED AND COLD SOLUTION IN THE ECMWF
SUPPORTIVE OF TEMPS COLDER THAN WHAT OUR CURRENT FORECAST BUT WITH
SO MUCH UNCERTAINTY SO NO REASON TO STRAY FROM THE BLENDED MODEL
CONSENSUS.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* SSWLY TO SWLY WINDS TO 25KT THIS AFTERNOON AND EVENING OUTSIDE
OF THUNDERSTORMS.
* TIMING AND CHANCES OF ADDITIONAL TSRA THIS AFTERNOON TONIGHT.
* OCNL MVFR CIGS THIS AFTERNOON AND TONIGHT.
KREIN
//DISCUSSION...UPDATED 18Z...
MAIN CONCERN CONTINUES TO BE THE CHANCES FOR THUNDERSTORMS THIS
AFTERNOON AND TONIGHT...UNTIL A COLD FRONTAL PASSAGE TOMORROW
MORNING.
THE ENVIRONMENT OVER THE AREA IS WARM AND MOIST WITH TEMPERATURES
IN THE 80S AND DEWPOINTS IN UPPER 60S. OLD OUTFLOW BOUNDARIES FROM
EARLIER CONVECTIVE ACTIVITY CAN PROVIDE THE FOCUS FOR ADDITIONAL
THUNDERSTORM DEVELOPMENT...BUT TIMING IS VERY UNCERTAIN AND
RESIDUAL CLOUD COVER MAY BE A LIMITING FACTOR FOR THE NEXT FEW
HOURS AS BOTH CI AND LOWER STRATOCU ARE FILTERING TH SUNSHINE.
ANTICIPATE THAT CLOUD COVER SHOULD THIN WITH TIME AND IS THE TREND
IN THE LATEST SATELLITE IMAGERY...SO THERE WILL BE A CHANCE FOR
SCATTERED THUNDERSTORM DEVELOPMENT THROUGH THE AFTERNOON AND
EVENING. GIVEN THE TIMING AND COVERAGE UNCERTAINTIES...HAVE BACK
OFF TO JUST VCTS MENTION...UNTIL A MORE ORGANIZED FOCUSING
MECHANISM BECOMES APPARENT. HAVE MAINTAINED THE PROB30 MENTION FOR
THUNDER FOR THE LATE NIGHT TO EARLY MORNING HOURS...IN CONJUNCTION
WITH THE APPROACHING COLD FRONT. EXPECT THAT WINDS SHOULD SHIFT TO
WESTERLY FOLLOWING THE FROPA...WHILE REMAINING RELATIVELY BRISK
AND GUSTY.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM TO HIGH CONFIDENCE IN WIND FORECAST.
* MEDIUM CONFIDENCE IN CEILING TRENDS.
* LOW CONFIDENCE CONVECTIVE TIMING AND COVERAGE TODAY AND TONIGHT.
* MEDIUM TO HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
* TUESDAY NIGHT...VFR.
* WEDNESDAY...SLIGHT CHANCE OF PM SHRA.
* THURSDAY...CHANCE OF SHRA.
* FRIDAY...SLIGHT CHANCE OF SHRA.
* SATURDAY AND SUNDAY...DRY/VFR.
KJB
&&
.MARINE...
323 AM CDT
AN AREA OF LOW PRESSURE ACROSS THE MID MISSOURI VALLEY EARLY THIS
MORNING WILL TRACK NORTHEASTWARD TOWARDS LAKE SUPERIOR BY TONIGHT.
AS THIS OCCURS...AN ASSOCIATED WARM FRONT IS EXPECTED TO LIFT
NORTHWARD UP THE LAKE THROUGH TONIGHT. AREAS OF FOG...POTENTIALLY
DENSE WILL BE LIKELY ACROSS PORTIONS OF THE LAKE TODAY AND TONIGHT
AS THIS FRONT...AND THE ACCOMPANYING VERY MOIST AIR MASS MOVES OVER THE
COOL LAKE WATERS. A MARINE DENSE FOG ADVISORY MAY BE NEEDED.
THE OTHER CONCERN WILL BE THE WINDS TODAY AND TONIGHT WITH THIS WARM
FRONT LIFTING UP THE LAKE. THE WINDS SOUTH OF THIS WARM FRONT WILL
BECOME SOUTHERLY AROUND 25 KT TODAY...WHILE NORTH OF THE WARM
FRONT...SOME STOUT EASTERLY WINDS WILL BE LIKELY. THESE GUSTY
SOUTHERLY WINDS WILL RESULT IN LIKELY RESULT IN NEAR SMALL CRAFT
ADVISORY WINDS OVER THE ILLINOIS AND INDIANA NEAR SHORE WATERS BY
MIDDAY. HOWEVER...IN SPITE OF THIS...I HAVE OPTED TO HOLD OFF ON AN
ADVISORY DUE TO THERE BEING SOME QUESTION AS TO EXACTLY HOW STRONG
THE WINDS WILL BE OVER THE NEAR SHORE WATERS. IN ADDITION...WITH THE
OFFSHORE COMPONENT...WAVES WILL LIKELY NOT BUILD OVER 4 FT IN THE
NEAR SHORE WATERS. THE POTENTIAL IS CERTAINLY THERE FOR 25+ KT
OFFSHORE FLOW TODAY...WITH THE POTENTIAL NEED FOR AN UPGRADE TO A
SMALL CRAFT ADVISORY.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM MONDAY.
DENSE FOG ADVISORY...LMZ567-LMZ669-LMZ671-LMZ868-LMZ870-LMZ872
UNTIL 3 PM MONDAY.
DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565
UNTIL 1 AM TUESDAY.
&&
$$
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Area Forecast Discussion
National Weather Service Lincoln IL
1253 PM CDT Mon May 12 2014
.DISCUSSION...
ISSUED 949 AM CDT Mon May 12 2014
Another warm and humid day is unfolding across central Illinois,
as 14z/9am temps have already risen well into the 70s. The area
remains convection-free for the time being, but as weak capping is
broken over the next couple of hours widely scattered thunderstorms
will begin to develop. Enhanced Cu field is currently evident on
visible satellite imagery from Arkansas northeastward across the
eastern half of the KILX CWA. Latest mesoanalysis from SPC
indicates deep layer moisture convergence maximized from southeast
Missouri into southeast Illinois, where HRRR shows scattered
thunderstorm development between now and 18z. Elsewhere around
central Illinois, convection will likely remain more isolated in
nature until later this afternoon when cold front begins to
approach from the west. Front is still progged to reach the area
after dark tonight, so best chances for widespread convection will
likely hold off until late afternoon/early evening in the Illinois
River Valley, then further east across the remainder of the area
overnight.
Barnes
&&
.AVIATION...
ISSUED 1253 PM CDT Mon May 12 2014
Main aviation concern during the 18z TAF period will be timing of
potential convection later this afternoon into tonight. Model
solutions are all over the place concerning convective initiation:
however, best forcing associated with cold front and other
mesoscale boundaries appears that it will stay west of the central
Illinois terminals until evening. HRRR tries to develop scattered
showers/storms west of I-55 between 20z and 23z, while NAM
continues to focus mainly on the evening hours. Will include VCTS
at all TAF sites from mid-afternoon on, but will not mention
predominant thunder until later. Based on NAM solution, will
include TSRA between 00z and 04z at KPIA, then further east to
KCMI between 05z and 09z. Once initial line of storms passes, a
period of light rain will likely linger along and just behind the
cold front overnight into early Tuesday morning. Forecast
soundings suggest MVFR ceilings with this precip. Winds will
initially be from the S/SW this afternoon, gusting to between 20
and 25kt at times. S/SW winds will continue through the evening
before veering to the W/NW after FROPA overnight. Winds will shift
to the W/NW at KPIA by 09z, then further east to KCMI by 15z.
Barnes
&&
.PREV DISCUSSION...
ISSUED 330 AM CDT Mon May 12 2014
SHORT TERM...Today through Wednesday night
Quiet conditions temporarily returned to central and southeast IL
early this morning as convection with MCS had shifted east of IL
into east central IN and Ohio, and a larger area of convection with
a couple MCSS was over WI/IA and eastern KS into far nw MO. Cold
front over western IA and eastern KS into central OK and west Texas
while warm front was over northern IL. Moist dewpoints in the
upper 60s over central and southern IL and mild temps 69-75F with
sse winds in warm sector.
Strong upper level trof over the Rockies with 557 dm 500 mb low
over western CO to eject surface 1002 mb low over east central KS
ne into the upper MS river valley by midnight tonight and swing a
cold front east across IL overnight. 00Z models are in fair
agreement with timing of this cold frontal passage. Isolated to
scattered thunderstorms to develop during today especially this
afternoon over the IL river valley as air mass destabilizes with
CAPES increasing to 1500-2500 J/kg. Best chances of convection
will be tonight with slight chance of severe storms nw of IL river
this evening. Best risk of severe supercells with possible
tornados form mid afternoon into mid evening will be over eastern IA
northern MO into far nw IL and sw WI where stronger wind shear
will be. Another very warm and humid day with highs in the mid 80s
with a few areas se of IL river even seeing upper 80s with enough
sunshine.
Cold front to pass east into Indiana early Tue morning and have
highest chances of convection over eastern IL Tue morning and
diminishing to the west. SPC has 5% risk of severe storms Tue from
Wabash river east so mostly over IN. Highs Tue range from mid 60s
from I-55 west to the low to mid 70s east of I-57 in eastern IL.
Looks like a lull in shower chances over central IL Tue night
though kept chances of showers over southern areas especially se
IL closer to frontal boundary stalling just se of IL. Leaned on
wetter ECMWF and NAM models with surface low ejecting ne Wed and
passing just se of IL while GFS appears too weak and far to the
east with its QPF fields. Have isolated thunderstorms Wed se of
I-70 while SPC keeps slight risk of severe storms se of IL Wed.
Showers to diminish from the west during Wed night with highest
chances near the IN border Wed evening. Cooler highs in the upper
50s and lower 60s Wed and these cooler readings to linger Thu.
LONG TERM...Thursday through Monday
Medium to long range models and their ensembles continues to
advertise large upper level trof over the MS river valley Thu
and upper level low lifting north of the Great Lakes this weekend
while trof shifts east into the eastern states. As core of coolest
850 mb air shifts ne of central IL during the weekend with upper
level low, expect temperatures to modify during this weekend into
early next week but generally still stay a below normal. Cool
nights in the low to mid 40s Thu night through Sat night.
Instability light rain showers possible Thu & Fri especially
during the afternoon and early evening with disturbances pivoting
thru the nearby upper level trof. Isolated light showers still
possible Sat sw of I-74 while dry conditions then prevail from Sat
night through Monday.
07
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
102 PM CDT MON MAY 12 2014
.SHORT TERM /TODAY/... ISSUED AT 321 AM CDT MON MAY 12 2014
TWO PROBLEMS TODAY ARE BOTH WITH CONVECTION THE EARLY MORNING
CONVECTION WILL BE AN ISSUE WITH THE POTENTIAL FOR LOCALLY HEAVY
RAINFALL MOVING INTO ALREADY SATURATED AREAS. THIS IS ASSOCIATED
WITH A WEAK WAVE IN THE FLOW THAT IS LIFTING NORTHEAST ACROSS THE
STATE. ADDITIONAL DEVELOPMENT IS LIKELY OVER THE SOUTHEAST HALF OF
THE STATE WITH THE COLD FRONT PROGRESSING EAST. THE HRRR HAS WHAT
SEEMS TO BE A REASONABLE HANDLE ON THIS. SEVERITY WILL DEPEND ON
HOW MUCH RECOVERY WE CAN ACHIEVE AFTER THE MORNING CONVECTION.
.LONG TERM /TONIGHT THROUGH SUNDAY/...
ISSUED AT 321 AM CDT MON MAY 12 2014
PRECIPITATION WILL MOVE OUT OF THE STATE BY 06Z AS THE PATTERN
CHANGES FROM A SOUTHWEST FLOW TO A NORTHWEST FLOW. CANADIAN HIGH
PRESSURE WILL DOMINATE THE WEEKS WEATHER WITH TEMPERATURES WELL
BELOW NORMAL. WILL POTENTIAL NEED TO CONSIDER SOME FROST WORDING
LATER IN THE WEEK, BUT CERTAINTY IS NOT THERE AT THIS TIME BECAUSE
OF THE POTENTIAL FOR SOME CLOUD COVER. IT WILL LIKELY TAKE UNTIL
THE WEEKEND BEFORE THE COOL HIGH PRESSURE MOVES OFF TO THE EAST.
WARMING AND AN INCREASED CHANCE FOR THUNDERSTORMS IS EXPECTED
LATER IN THE WEEKEND.
&&
.AVIATION...12/18Z
ISSUED AT 102 PM CDT MON MAY 12 2014
UNSETTLED WEATHER EXPECTED THRU THE TAF PD AS A SFC COLD FRONT
SWEEPS THRU THE RGN. SHRA/TSRA POSSIBLE THRU THIS EVE AT THE
KOTM...KDSM AND KALO TERMINALS. IFR/MVFR CIGS FILL IN BEHIND THE
FROPA. IFR/MVFR CIGS EXPECTED TO LIFT BY 15Z TUE.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...MS MAY 14
LONG TERM...MS MAY 14
AVIATION...ZOGG
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
318 PM CDT MON MAY 12 2014
.DISCUSSION...
SIGNIFICANT HEAVY RAINFALL EVENT IS IN ITS BEGINNING STAGES ACROSS
CENTRAL AND N TX THIS AFTN PER REGIONAL MOSAIC RADAR IMAGERY.
MODELS ARE IN GOOD AGREEMENT THAT THIS EVENT WILL CONTINUE TO
UNFOLD AS THE FRONT PUSHES EWD INTO OUR REGION THIS EVENING/TONIGHT.
THE HEAVIEST RAINFALL IS EXPECTED TO FALL DURING THE OVERNIGHT
HOURS...BEFORE THE FRONT OUTRUNS THE UPPER LEVEL SUPPORT. TRAINING
OF STORMS...ESPECIALLY OVER AREAS THAT HAVE SEEN SIGNIFICANT
RAINFALL WITHIN THE LAST 7 DAYS WILL BRING THE THREAT OF FLASH
FLOODING TO MUCH OF E TX/SE OK/SW AR. IT APPEARS THAT THIS THREAT
MAY BEGIN EARLIER THAN ANTICIPATED...SO HAVE PUSHED THE START TIME
OF THE FLASH FLOOD WATCH UP TO 7 PM THIS EVENING. THE HEAVIEST
RAINFALL IS EXPECTED TO FALL DURING THE OVERNIGHT HOURS...BEFORE
THE FRONT OUTRUNS THE UPPER LEVEL SUPPORT. LIFT WILL BECOME MORE
ISENTROPIC AS WE LOSE THE SFC FORCING DURING THE DAY TUESDAY...
WHICH WILL LIKELY RESULT IN DECREASING RAIN RATES. DESPITE THIS...
A CONTINUING THREAT FOR FLASH FLOODING MAY BE SEEN DUE TO THE
OVERNIGHT RAINS...AND THE WATCH MAY NEED TO BE EXTENDED INTO
WEDNESDAY. MODELS CONTINUE TO BE IN RESPECTABLE AGREEMENT WITH
REGARD TO QPF...PAINTING A WIDESPREAD 3-5 INCHES /WITH HIGHER
ISOLD TOTALS LIKELY/ ACROSS THE WATCH AREA...TAPERING OFF
SIGNIFICANTLY TO THE SE.
RAIN IS EXPECTED TO FINALLY COME TO AN END WEDNESDAY
AFTERNOON/NIGHT...AS THE BASE OF THE UPPER TROF MOVES OVERHEAD.
UNSEASONABLY COOL TEMPERATURES ARE STILL EXPECTED TUESDAY THROUGH
THURSDAY AS NW FLOW ALOFT AND A COOL AIRMASS LINGER OVER THE
REGION. MODELS CONTINUE TO TOY WITH A BACK-DOOR COLD FRONT
DROPPING INTO OUR EXTREME N DURING FRI/SAT...WITH POSSIBLY SOME
LIGHT PRECIP OVER THE NRN HALF OF OUR REGION. BOTH THE GFS AND
EURO STALL THE FRONT TO OUR N...SO TEMPS ARE EXPECTED TO GRADUALLY
WARM THROUGH THE WEEKEND. /12/
&&
.PREV DISCUSSION... /ISSUED 1229 PM CDT MON MAY 12 2014/
AVIATION...
OBSERVED SOUNDING THIS MORNING FROM SHV SHOWED A NEARLY SATURATED
SOUNDING TO NEAR 10KFT AND STRONG LOW LEVEL WINDS IN EXCESS OF
30KTS IN THE LOWEST 5KFT. LATE MORNING/EARLY AFTERNOON HEATING AND
A WEAKLY CAPPED ENVIRONMENT HAS RESULTED IN THE DEVELOPMENT OF
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS IN AND AROUND THE
TERMINALS THIS AFTERNOON. CURRENTLY CEILINGS RANGE FROM NEAR 3KFT
TO NEAR 6KFT BUT EXPECT BRIEF MVFR CONDITIONS WITH BOTH CEILINGS
AND VSBYS IF AND WHEN ANY CONVECTION MOVES OVER A TERMINAL
LOCATION. A STRONG PRESSURE GRADIENT WILL KEEP SSE WINDS SUSTAINED
NEAR 10-12KTS WITH HIGHER GUSTS THROUGH THE EARLY EVENING HOURS.
LATEST HRRR PROGS SHOW THIS SCATTERED ACTIVITY CONTINUING THROUGH
THE AFTERNOON WITH MORE OF A SOLID LINE OF CONVECTION MOVING
EASTWARD FROM N CENTRAL TEXAS/CENTRAL OK LATER THIS EVENING ALONG
AND AHEAD OF A STRONG COLD FRONT. HANDLED THE SCATTERED AFTERNOON
CONVECTION WITH VCTS WITH TEMPO GROUPS BUT PREVAILED TSRA DURING
THE EVENING AND OVERNIGHT HOURS ACROSS ALL BUT OUR EASTERN MOST
TERMINAL LOCATIONS BASED ON THE HRRR PROGRESSION ON THE CONVECTIVE
LINE. /13/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 67 72 56 67 48 / 90 70 60 60 10
MLU 68 82 62 70 48 / 30 60 50 60 10
DEQ 59 65 52 65 40 / 100 60 60 50 10
TXK 60 66 54 64 46 / 100 70 60 60 10
ELD 66 72 55 65 43 / 70 70 50 60 10
TYR 60 64 53 67 46 / 100 60 60 30 10
GGG 62 67 54 66 45 / 100 70 60 30 10
LFK 69 73 56 69 47 / 80 70 50 40 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...FLASH FLOOD WATCH FROM 7 PM CDT THIS EVENING THROUGH TUESDAY
AFTERNOON FOR THE FOLLOWING ZONES:
ARZ050-051-059>061-070>072.
LA...FLASH FLOOD WATCH FROM 7 PM CDT THIS EVENING THROUGH TUESDAY
AFTERNOON FOR THE FOLLOWING ZONES: LAZ001>003.
OK...FLASH FLOOD WATCH FROM 7 PM CDT THIS EVENING THROUGH TUESDAY
AFTERNOON FOR THE FOLLOWING ZONES: OKZ077.
TX...FLASH FLOOD WATCH FROM 7 PM CDT THIS EVENING THROUGH TUESDAY
AFTERNOON FOR THE FOLLOWING ZONES:
TXZ096-097-108>112-124>126-136>138-149>151.
&&
$$
12
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1229 PM CDT MON MAY 12 2014
.AVIATION...
OBSERVED SOUNDING THIS MORNING FROM SHV SHOWED A NEARLY SATURATED
SOUNDING TO NEAR 10KFT AND STRONG LOW LEVEL WINDS IN EXCESS OF
30KTS IN THE LOWEST 5KFT. LATE MORNING/EARLY AFTERNOON HEATING AND
A WEAKLY CAPPED ENVIRONMENT HAS RESULTED IN THE DEVELOPMENT OF
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS IN AND AROUND THE
TERMINALS THIS AFTERNOON. CURRENTLY CEILINGS RANGE FROM NEAR 3KFT
TO NEAR 6KFT BUT EXPECT BRIEF MVFR CONDITIONS WITH BOTH CEILINGS
AND VSBYS IF AND WHEN ANY CONVECTION MOVES OVER A TERMINAL
LOCATION. A STRONG PRESSURE GRADIENT WILL KEEP SSE WINDS SUSTAINED
NEAR 10-12KTS WITH HIGHER GUSTS THROUGH THE EARLY EVENING HOURS.
LATEST HRRR PROGS SHOW THIS SCATTERED ACTIVITY CONTINUING THROUGH
THE AFTERNOON WITH MORE OF A SOLID LINE OF CONVECTION MOVING
EASTWARD FROM N CENTRAL TEXAS/CENTRAL OK LATER THIS EVENING ALONG
AND AHEAD OF A STRONG COLD FRONT. HANDLED THE SCATTERED AFTERNOON
CONVECTION WITH VCTS WITH TEMPO GROUPS BUT PREVAILED TSRA DURING
THE EVENING AND OVERNIGHT HOURS ACROSS ALL BUT OUR EASTERN MOST
TERMINAL LOCATIONS BASED ON THE HRRR PROGRESSION ON THE CONVECTIVE
LINE.
&&
.PREV DISCUSSION... /ISSUED 1055 AM CDT MON MAY 12 2014/
DISCUSSION...
WIDELY SCATTERED SHWRS/TSTMS ONGOING THIS MORNING...MOSTLY
ASSOCIATED WITH A WEAK PIECE OF ENERGY /BARELY VISIBLE IN WV
IMAGERY/ MOVING SEWD ACROSS E TX. SCATTERED CONVECTION WILL
CONTINUE TO DEVELOP WITH HEATING...BEFORE THE BIG SHOW BEGINS LATE
THIS AFTERNOON/EARLY THIS EVENING WITH THE APPROACH OF THE FRONT.
THE FRONT IS CURRENTLY ALONG A ABILENE/WICHITA FALLS/STILLWATER
LINE AND MAKING SIGNIFICANT EWD PROGRESS. THAT SAID...CURRENT
TEMP/POP FCST IS ON-TRACK...SO NO CHANGES TO THESE MAJOR FCST
ELEMENTS ARE EXPECTED. WIND-WISE...WIND SPEEDS ARE RUNNING
SIGNIFICANTLY LOWER THAN PREVIOUSLY ANTICIPATED...AND WELL BELOW
LAKE WIND ADVISORY CRITERIA. HAVE GONE AHEAD AND MADE THE
NECESSARY ADJUSTMENTS TO THE WIND GRIDS AND DROPPED THE ADVISORY.
/12/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 68 70 56 66 49 / 70 70 60 50 10
MLU 67 80 62 69 48 / 50 60 60 60 20
DEQ 59 65 52 64 41 / 90 60 50 60 10
TXK 60 66 54 65 47 / 90 70 60 60 10
ELD 66 72 55 65 44 / 70 70 60 60 20
TYR 61 65 51 65 47 / 90 60 60 30 10
GGG 62 67 53 66 47 / 90 70 60 50 10
LFK 69 75 57 69 49 / 70 70 60 50 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...FLASH FLOOD WATCH FROM 10 PM CDT THIS EVENING THROUGH TUESDAY
AFTERNOON FOR THE FOLLOWING ZONES:
ARZ050-051-059>061-070>072.
LA...FLASH FLOOD WATCH FROM 10 PM CDT THIS EVENING THROUGH TUESDAY
AFTERNOON FOR THE FOLLOWING ZONES: LAZ001>003.
OK...FLASH FLOOD WATCH FROM 10 PM CDT THIS EVENING THROUGH TUESDAY
AFTERNOON FOR THE FOLLOWING ZONES: OKZ077.
TX...FLASH FLOOD WATCH FROM 10 PM CDT THIS EVENING THROUGH TUESDAY
AFTERNOON FOR THE FOLLOWING ZONES:
TXZ096-097-108>112-124>126-136>138-149>151.
&&
$$
13
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
421 PM EDT MON MAY 12 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 420 PM EDT MON MAY 12 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A DEEP MID LEVEL TROUGH FROM
WRN MANITOBA INTO THE SRN ROCKIES RESULTING IN SW FLOW FROM THE SRN
PLAINS INTO THE WRN GREAT LAKES. AT THE SFC... LOW PRES WAS LOCATED
OVER WRN WI WITH A COLD FRONT TO THE SE THROUGH CNTRL IA AND A WARM
FRONT INTO NRN WI. RADARS INDICATED THERE WAS A GAP IN THE PCPN OVER
NRN WI AND UPPER MI AS ONE MCS SLIDES TO THE E INTO WRN LOWER MI AND
ANOTHER LINE OF CONVECTION STRETCHED TO THE SW FROM ERN IA. WITH
ABUNDANT LOW LEVEL MOISTURE OVER THE AREA...AREAS OF FOG HAD
DEVELOPED ESPECIALLY IN AREAS WITH UPSLOPE ERLY FLOW.
TONIGHT...AS SFC LOW PRES LIFTS FROM WRN WI ACROSS WRN LAKE SUPERIOR
TONIGHT...THE WARM FRONT WILL ATTEMPT TO MOVE INTO UPPER MI. AT THIS
POINT...IT APPEARS THE WARM FRONT MAY JUST SLIP INTO FAR SRN UPPER
MI. SHRA/TSRA ARE EXPECTED TO DEVELOP BUT THE GREATEST COVERAGE IS
EXPECTED FROM WI INTO FAR SRN UPPER MI...CLOSER TO THE HIGHER
INSTABILITY AND MORE FAVORABLE LOW LEVEL INFLOW. WITH ELEVATED CAPE
UP AROUND 1000J/KG AND DEEP LAYER SHEAR AROUND 30KT OR SO...STORMS
WILL HAVE THE POTENTIAL TO BECOME ORGANIZED WITH ISOLD SVR
POSSIBLE...MAINLY OVER FAR SCNTRL UPPER MI...CLOSER TO WARM FRONT.
THE MAIN THREAT SHOULD BE HAIL...BUT WITH PWATS NEAR 1.5 INCH
...HEAVY RAINFALL WILL ALSO BE POSSIBLE. ADDITIONAL SHRA/TSRA MAY
ALSO DEVELOP LATE TONIGHT ALONG THE COLD FRONT AS IT MOVES INTO THE
W HALF BTWN 06Z-12Z.
TUE...SHRA/TSRA WILL BE LIKELY IN THE MORNING OVER THE EAST HALF AS
THE COLD FRONT MOVES THROUGH THE AREA. OTHERWISE...STRONG DRYING
WILL MOVE INTO THE REST OF THE CWA. TEMPERATURES MAY CLIMB TO AROUND
60 BEFORE CAA STRENGTHENS IN THE AFTERNOON. GUSTY WEST WINDS WILL
ALSO DEVELOP ESPECIALLY ACROSS THE HIGHER TERRAIN OF THE KEWEENAW.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 401 PM EDT MON MAY 12 2014
NAM SHOWS A CLOSED 500 MB LOW OVER EASTERN MANITOBA 00Z WED WITH A
TROUGH OVER THE UPPER GREAT LAKES AND A RIDGE ON THE WEST COAST.
THIS TROUGH DOES NOT MOVE MUCH THROUGH THU. NAM SHOWS SOME 850-500
MB Q-VECTOR CONVERGENCE THROUGH THE PERIOD WITH THE STRONGEST
CONVERGENCE OVER THE ERN CWA. MOISTURE STAYS LIMITED UNTIL THU AND
WILL REMAIN DRY THROUGH WED NIGHT BEFORE MOISTURE MOVES IN.
TEMPERATURES WILL REMAIN BELOW NORMAL THROUGH THIS FORECAST PERIOD
AND DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST.
IN THE EXTENDED...GFS AND ECMWF SHOW A 500 MB TROUGH OVER THE UPPER
GREAT LAKES 12Z FRI WITH A RIDGE OVER THE WESTERN U.S. PATTERN
CHANGES LITTLE 12Z SAT WITH THE RIDGE MOVING INTO THE PLAINS ON SUN
AND THE TROUGH MOVING INTO THE LOWER GREAT LAKES. THE RIDGE MOVES
INTO THE MISSISSIPPI RIVER VALLEY ON MON. TEMPERATURES LOOK TO STAY
BELOW NORMAL THIS FORECAST PERIOD WITH A SLOW MODIFICATION TREND AND
LOOKS WET THIS FORECAST PERIOD UNTIL SUN AND SUN NIGHT WHEN THE
UPPER RIDGE MOVES IN. OTHERWISE...PCPN CHANCES WILL STAY LOW
THROUGH THE PERIOD. HAVING SOME SNOW IN DURING THE LATE NIGHT AND
EARLY MORNING HOURS THU NIGHT THROUGH SAT MORNING STILL LOOKS GOOD
AS WELL WITH COLD ENOUGH TEMPERATURES TO NOT COMPLETELY RULE THIS
POSSIBILITY OUT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 142 PM EDT MON MAY 12 2014
AFTER THE WIDESPREAD MODERATE RAINFALL...ABUNDANT LOW LEVEL MOISTURE WILL
REMAIN ACROSS THE REGION THIS AFTERNOON EVEN THOUGH THERE WILL LITTLE
ADDITIONAL RAIN. AS A RESULT...LIFR CONDITIONS WILL LINGER INTO THIS
EVENING. SHRA WILL REDEVELOP TONIGHT WITH LIFR/IFR CONDITIONS
PREVAILING. THERE COULD BE SOME TSRA AS WELL...PARTICULARLY AROUND
KSAW...BUT LIMITED CONFIDENCE IN TIMING/COVERAGE OF TSRA PRECLUDES A
MENTION IN THIS FCST. CONDITIONS WILL IMPROVE TO MVFR TUE MORNING
WITH LOW LEVEL DRYING IN THE WAKE OF A COLD FRONT. WEST WINDS WILL
ALSO BECOME GUSTY...ESPECIALLY AT CMX.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 420 PM EDT MON MAY 12 2014
NE GALES ACROSS WRN LAKE SUPERIOR LATE THIS AFTERNOON INTO THIS
EVENING WILL DIMINISH OVERNIGHT AS LOW PRES LIFTS TOWARD THE AREA
AND THE PRES GRADIENT WEAKENS. ONCE THE LOW MOVES NORTH OF THE LAKE
TUE MORNING...STRONG WEST WINDS WILL DEVELOP. THE GUSTY WINDS WILL
SLOWLY DIMINISHING BELOW 25 KTS BY WEDNESDAY MORNING. WINDS FOR THE REST
OF THE WEEK WILL MAINLY BE BLO 20 KTS. HOWEVER...A LOW PRESSURE
SYSTEM COULD IMPACT THE REGION LATE THIS WEEK WITH WINDS OVER 25 KTS
THURSDAY INTO FRIDAY. UNCERTAINTY IS HIGH WITH THAT SYSTEM
THOUGH...SO CURRENT FORECAST WILL ONLY CALL FOR NORTHWEST TO 20 KTS
AT THIS TIME.
&&
.HYDROLOGY...
ISSUED AT 401 PM EDT MON MAY 12 2014
RAINFALL AMOUNTS FOR THIS WHOLE RAIN EVENT THROUGH TUE AFTERNOON MAY
EXCEED ONE TO ONE AND A HALF INCHES OVER PORTIONS OF WESTERN UPR
MICHIGAN. RAIN CHANCES DIMINISH FROM WEST TO EAST ON TUESDAY AS A
FRONTAL BOUNDARY EXITS THE REGION. RAINFALL WILL ONLY ADD TO THE
ONGOING SNOWMELT AND ALREADY HIGH FLOWS ON AREA RIVERS AND STREAMS.
THE MICHIGAMME RIVER NEAR REPUBLIC AND WITCH LAKE...THE STURGEON
RIVER AT CHASSELL AND ALSTON AND THE MICHIGAMME RIVER DOWNSTREAM OF
THE WAY DAM TO THE EAST OF CRYSTAL FALLS ARE UNDER FLOOD WARNINGS.
GIVEN THE RAINFALL THAT WILL OCCUR THE NEXT 24-36 HOURS...RIVER
LEVELS WILL KEEP RISING AND ADJUSTMENTS WILL LIKELY BE NEEDED BASED
ON LATEST TRENDS. ALL THIS WATER DUE TO THE SNOWMELT AND THE
RAINFALL WILL TAKE A WHILE TO WORK THROUGH THE RIVERS...SO IT IS
QUITE LIKELY THAT HIGHER RIVER FLOWS AND THE ASSOCIATED ADVISORIES
AND WARNINGS ON AREA RIVERS WILL CONTINUE THROUGH LATE THIS
WEEK...IF NOT INTO THIS WEEKEND. THOSE LIVING NEAR
RIVERS...CREEKS...AND STREAMS SHOULD CONTINUE TO MONITOR THE LATEST
RIVER LEVELS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL MIDNIGHT EDT /11 PM CDT/ TONIGHT FOR LSZ162.
GALE WARNING UNTIL 11 PM EDT THIS EVENING FOR LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...07
AVIATION...JLB
MARINE...JLB
HYDROLOGY...07
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
402 PM EDT MON MAY 12 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 515 AM EDT MON MAY 12 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A BUILDING RIDGE ALONG THE
W COAST OF NAMERICA WITH AMPLIFIED DOWNSTREAM TROF OVER THE ROCKIES.
MAIN PIECE OF ENERGY IS IN THE BASE OF THE TROF OVER COLORADO.
WAA/ISENTROPIC ASCENT DOWNSTREAM INTO THE UPPER LAKES IS SUPPORTING
A LARGE AREA OF SHRA/TSRA LIFTING NE ACROSS MN/WI EARLY THIS
MORNING. SHORTWAVE MOVING NE INTO WRN WI IS FURTHER AIDING THE PCPN.
INSTABILITY HAS BEEN SLOW TO ADVANCE N PER SPC MESOANALYIS...SO
WHILE SHRA ARE ADVANCING STEADILY N AND E...TSRA ARE LAGGING FARTHER
AND FARTHER S WITHIN THE OVERALL SHRA AREA.
HIGH RES MODEL GUIDANCE...PARTICULARLY THE HIGH RES RAPID REFRESH...
HAS A DECENT HANDLE ON APPROACHING SHRA. UTILIZED RADAR TRENDS AND
HIGH RES GUIDANCE TO SWING A PERIOD OF CATEGORICAL POPS ACROSS THE
FCST AREA THIS MORNING. FORTUNATELY...PCPN AMOUNTS DON`T LOOK TO BE
EXCESSIVE AS MAIN AREA OF TSRA WILL PASS BY TO THE S. STILL...
EXPECT ROUGHLY 0.5 TO 0.75 INCHES WHICH WILL GIVE AREA
RIVERS/STREAMS A BOOST IN FLOW. AS SUPPORTING SHORTWAVE MOVES NE OF
THE AREA...MUCH OF THE AFTN MAY TURN DRY IN ITS WAKE. POPS WERE
LOWERED INTO THE CHC/SCT CATEGORY...BUT BELIEVE MANY AREAS WILL
PROBABLY SEE A GOOD PERIOD OF DRY WEATHER THIS AFTN. WITH PCPN AT A
MINIMUM DURING THE AFTN...TEMPS WILL HAVE A CHANCE TO RESPOND...AT
LEAST IN AREAS WHERE GENERAL EASTERLY FLOW IS NOT OFF THE GREAT
LAKES. BUMPED TEMPS UP INTO THE UPPER 50S/LWR 60S ACROSS MUCH OF THE
INTERIOR. HIGH RES RAPID REFRESH SHOWS TEMPS RISING TO AROUND 70F
OVER THE INTERIOR W THIS AFTN...CERTAINLY POSSIBLE IF CLOUDS THIN
OUT SUFFICIENTLY.
AS SFC LOW PRES LIFTS FROM WRN WI ACROSS WRN LAKE SUPERIOR
TONIGHT...WARM FRONT WILL ATTEMPT TO MOVE INTO UPPER MI. AT THIS
POINT...IT APPEARS THE WARM FRONT MAY JUST SLIP INTO FAR SRN UPPER
MI. ADDITIONAL SHRA/TSRA WILL LIKELY DEVELOP AS SFC LOW/WARM FRONT
LIFT N...THOUGH PCPN COVERAGE PROBABLY WON`T BE AS WIDESPREAD AS
WHAT WILL OCCUR THIS MORNING. WITH ELEVATED CAPE UP AROUND 1000J/KG
AND DEEP LAYER SHEAR AROUND 30KT OR SO...STORMS WILL HAVE THE
POTENTIAL TO BECOME ORGANIZED WITH ISOLD SVR POSSIBLE...MAINLY OVER
FAR SCNTRL UPPER MI...CLOSER TO WARM FRONT. MAIN THREAT SHOULD BE
HAIL...BUT WITH PRECIPITABLE WATER 200-250PCT OF NORMAL...HVY
RAINFALL WILL BE A GOOD BET WITH ANY TSRA.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 401 PM EDT MON MAY 12 2014
NAM SHOWS A CLOSED 500 MB LOW OVER EASTERN MANITOBA 00Z WED WITH A
TROUGH OVER THE UPPER GREAT LAKES AND A RIDGE ON THE WEST COAST.
THIS TROUGH DOES NOT MOVE MUCH THROUGH THU. NAM SHOWS SOME 850-500
MB Q-VECTOR CONVERGENCE THROUGH THE PERIOD WITH THE STRONGEST
CONVERGENCE OVER THE ERN CWA. MOISTURE STAYS LIMITED UNTIL THU AND
WILL REMAIN DRY THROUGH WED NIGHT BEFORE MOISTURE MOVES IN.
TEMPERATURES WILL REMAIN BELOW NORMAL THROUGH THIS FORECAST PERIOD
AND DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST.
IN THE EXTENDED...GFS AND ECMWF SHOW A 500 MB TROUGH OVER THE UPPER
GREAT LAKES 12Z FRI WITH A RIDGE OVER THE WESTERN U.S. PATTERN
CHANGES LITTLE 12Z SAT WITH THE RIDGE MOVING INTO THE PLAINS ON SUN
AND THE TROUGH MOVING INTO THE LOWER GREAT LAKES. THE RIDGE MOVES
INTO THE MISSISSIPPI RIVER VALLEY ON MON. TEMPERATURES LOOK TO STAY
BELOW NORMAL THIS FORECAST PERIOD WITH A SLOW MODIFICATION TREND AND
LOOKS WET THIS FORECAST PERIOD UNTIL SUN AND SUN NIGHT WHEN THE
UPPER RIDGE MOVES IN. OTHERWISE...PCPN CHANCES WILL STAY LOW
THROUGH THE PERIOD. HAVING SOME SNOW IN DURING THE LATE NIGHT AND
EARLY MORNING HOURS THU NIGHT THROUGH SAT MORNING STILL LOOKS GOOD
AS WELL WITH COLD ENOUGH TEMPERATURES TO NOT COMPLETELY RULE THIS
POSSIBILITY OUT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 142 PM EDT MON MAY 12 2014
AFTER THE WIDESPREAD MODERATE RAINFALL...ABUNDANT LOW LEVEL MOISTURE WILL
REMAIN ACROSS THE REGION THIS AFTERNOON EVEN THOUGH THERE WILL LITTLE
ADDITIONAL RAIN. AS A RESULT...LIFR CONDITIONS WILL LINGER INTO THIS
EVENING. SHRA WILL REDEVELOP TONIGHT WITH LIFR/IFR CONDITIONS
PREVAILING. THERE COULD BE SOME TSRA AS WELL...PARTICULARLY AROUND
KSAW...BUT LIMITED CONFIDENCE IN TIMING/COVERAGE OF TSRA PRECLUDES A
MENTION IN THIS FCST. CONDITIONS WILL IMPROVE TO MVFR TUE MORNING
WITH LOW LEVEL DRYING IN THE WAKE OF A COLD FRONT. WEST WINDS WILL
ALSO BECOME GUSTY...ESPECIALLY AT CMX.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 504 AM EDT MON MAY 12 2014
EXPECT PERIOD OF STRONGER WINDS OVER LAKE SUPERIOR. APPROACHING LOW
PRESSURE SYSTEM RESULTS IN NORTHEAST WINDS INCREASING TO GALES BY
AFTN OVER WEST HALF OF LK SUPERIOR. WINDS TO 30 KTS OVER REST OF LK
SUPERIOR. STRONG WINDS DIMINISH BRIEFLY LATER THIS EVENING AND
OVERNIGHT TONIGHT AS THE LOW SLIDES ACROSS WESTERN LK SUPERIOR. ONCE
THE LOW MOVES NORTH OF THE LAKE ON TUESDAY MORNING...STRONG WEST
WINDS KICK UP. EXPECT THESE STRONG WESTERLIES...PROBABLY REACHING
GALES ON TUESDAY OVER NCNTRL LK SUPERIOR...TO SLOWLY FADE BLO 25 KTS
BY WEDNESDAY MORNING. WINDS REST OF THE WEEK WILL MAINLY BE BLO 20
KTS. HOWEVER...A LOW PRESSURE SYSTEM COULD IMPACT THE REGION LATE
THIS WEEK WITH WINDS OVER 25 KTS THURSDAY INTO FRIDAY. UNCERTAINTY
IS HIGH WITH THAT SYSTEM THOUGH...SO CURRENT FORECAST WILL ONLY CALL
FOR NORTHWEST TO 20 KTS AT THIS TIME.
&&
.HYDROLOGY...
ISSUED AT 401 PM EDT MON MAY 12 2014
RAINFALL AMOUNTS FOR THIS WHOLE RAIN EVENT THROUGH TUE AFTERNOON MAY
EXCEED ONE TO ONE AND A HALF INCHES OVER PORTIONS OF WESTERN UPR
MICHIGAN. RAIN CHANCES DIMINISH FROM WEST TO EAST ON TUESDAY AS A
FRONTAL BOUNDARY EXITS THE REGION. RAINFALL WILL ONLY ADD TO THE
ONGOING SNOWMELT AND ALREADY HIGH FLOWS ON AREA RIVERS AND STREAMS.
THE MICHIGAMME RIVER NEAR REPUBLIC AND WITCH LAKE...THE STURGEON
RIVER AT CHASSELL AND ALSTON AND THE MICHIGAMME RIVER DOWNSTREAM OF
THE WAY DAM TO THE EAST OF CRYSTAL FALLS ARE UNDER FLOOD WARNINGS.
GIVEN THE RAINFALL THAT WILL OCCUR THE NEXT 24-36 HOURS...RIVER
LEVELS WILL KEEP RISING AND ADJUSTMENTS WILL LIKELY BE NEEDED BASED
ON LATEST TRENDS. ALL THIS WATER DUE TO THE SNOWMELT AND THE
RAINFALL WILL TAKE A WHILE TO WORK THROUGH THE RIVERS...SO IT IS
QUITE LIKELY THAT HIGHER RIVER FLOWS AND THE ASSOCIATED ADVISORIES
AND WARNINGS ON AREA RIVERS WILL CONTINUE THROUGH LATE THIS
WEEK...IF NOT INTO THIS WEEKEND. THOSE LIVING NEAR
RIVERS...CREEKS...AND STREAMS SHOULD CONTINUE TO MONITOR THE LATEST
RIVER LEVELS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL MIDNIGHT EDT /11 PM CDT/ TONIGHT FOR LSZ162.
GALE WARNING UNTIL 11 PM EDT THIS EVENING FOR LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...07
AVIATION...JLB
MARINE...JLA
HYDROLOGY...07
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
144 PM EDT MON MAY 12 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 515 AM EDT MON MAY 12 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A BUILDING RIDGE ALONG THE
W COAST OF NAMERICA WITH AMPLIFIED DOWNSTREAM TROF OVER THE ROCKIES.
MAIN PIECE OF ENERGY IS IN THE BASE OF THE TROF OVER COLORADO.
WAA/ISENTROPIC ASCENT DOWNSTREAM INTO THE UPPER LAKES IS SUPPORTING
A LARGE AREA OF SHRA/TSRA LIFTING NE ACROSS MN/WI EARLY THIS
MORNING. SHORTWAVE MOVING NE INTO WRN WI IS FURTHER AIDING THE PCPN.
INSTABILITY HAS BEEN SLOW TO ADVANCE N PER SPC MESOANALYIS...SO
WHILE SHRA ARE ADVANCING STEADILY N AND E...TSRA ARE LAGGING FARTHER
AND FARTHER S WITHIN THE OVERALL SHRA AREA.
HIGH RES MODEL GUIDANCE...PARTICULARLY THE HIGH RES RAPID REFRESH...
HAS A DECENT HANDLE ON APPROACHING SHRA. UTILIZED RADAR TRENDS AND
HIGH RES GUIDANCE TO SWING A PERIOD OF CATEGORICAL POPS ACROSS THE
FCST AREA THIS MORNING. FORTUNATELY...PCPN AMOUNTS DON`T LOOK TO BE
EXCESSIVE AS MAIN AREA OF TSRA WILL PASS BY TO THE S. STILL...
EXPECT ROUGHLY 0.5 TO 0.75 INCHES WHICH WILL GIVE AREA
RIVERS/STREAMS A BOOST IN FLOW. AS SUPPORTING SHORTWAVE MOVES NE OF
THE AREA...MUCH OF THE AFTN MAY TURN DRY IN ITS WAKE. POPS WERE
LOWERED INTO THE CHC/SCT CATEGORY...BUT BELIEVE MANY AREAS WILL
PROBABLY SEE A GOOD PERIOD OF DRY WEATHER THIS AFTN. WITH PCPN AT A
MINIMUM DURING THE AFTN...TEMPS WILL HAVE A CHANCE TO RESPOND...AT
LEAST IN AREAS WHERE GENERAL EASTERLY FLOW IS NOT OFF THE GREAT
LAKES. BUMPED TEMPS UP INTO THE UPPER 50S/LWR 60S ACROSS MUCH OF THE
INTERIOR. HIGH RES RAPID REFRESH SHOWS TEMPS RISING TO AROUND 70F
OVER THE INTERIOR W THIS AFTN...CERTAINLY POSSIBLE IF CLOUDS THIN
OUT SUFFICIENTLY.
AS SFC LOW PRES LIFTS FROM WRN WI ACROSS WRN LAKE SUPERIOR
TONIGHT...WARM FRONT WILL ATTEMPT TO MOVE INTO UPPER MI. AT THIS
POINT...IT APPEARS THE WARM FRONT MAY JUST SLIP INTO FAR SRN UPPER
MI. ADDITIONAL SHRA/TSRA WILL LIKELY DEVELOP AS SFC LOW/WARM FRONT
LIFT N...THOUGH PCPN COVERAGE PROBABLY WON`T BE AS WIDESPREAD AS
WHAT WILL OCCUR THIS MORNING. WITH ELEVATED CAPE UP AROUND 1000J/KG
AND DEEP LAYER SHEAR AROUND 30KT OR SO...STORMS WILL HAVE THE
POTENTIAL TO BECOME ORGANIZED WITH ISOLD SVR POSSIBLE...MAINLY OVER
FAR SCNTRL UPPER MI...CLOSER TO WARM FRONT. MAIN THREAT SHOULD BE
HAIL...BUT WITH PRECIPITABLE WATER 200-250PCT OF NORMAL...HVY
RAINFALL WILL BE A GOOD BET WITH ANY TSRA.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 504 AM EDT MON MAY 12 2014
DEEP TROUGH FOR MAY AND REALLY ANYTIME OF THE YEAR STRETCHES FROM
CENTRAL CANADA TO THE SOUTHERN PLAINS ON TUESDAY. SFC LOW CURRENTLY
OVER THE CENTRAL PLAINS SHOULD BE JUST NORTHWEST OF LK SUPERIOR
DAYBREAK ON TUESDAY. OCCLUDED FRONT WILL BE SLICING ACROSS CWA
THROUGH MID MORNING...EXITING EASTERN CWA BY EARLY AFTN. SHOULD BE AT
LEAST SCT SHRA/TSRA EXPECTED ALONG AND AHEAD OF FRONT AS HIGHER
1000-850MB THETA-E POOLS ALONG THE BOUNDARY. SHARP DRYING ENDS ANY
RAIN QUICKLY OVER WEST HALF IN THE MORNING...BUT MAY SEE ISOLD
SHRA/TSRA OVER FAR SOUTHEAST CWA AS WEAK LOW-LEVEL CONVERGENCE
LINGERS AND AS ANOTHER WEAKER SHORTWAVE/Q-VECTOR CONVERGENCE AT
H85-H5 LIFTS OVER FAR EAST CWA. ANY STORMS AHAEAD OF FRONT IN THE
MORNING SHOULD BE WEAK AS 1-6KM MUCAPE AND MLCAPE BOTH DIMINISH
STEADILY COMPARED TO THE OVERNIGHT HOURS. TEMPS WILL RISE INTO THE
60S OVER THE CNTRL WHERE WEST WINDS DOWNSLOPE...IMT-ESC-MNM...BUT
WILL STAY IN THE 50S OVER THE WESTERN/NORTHWEST CWA WITH GRADIENT
WINDS OFF LK SUPERIOR. THOSE WINDS COULD BE QUITE GUSTY...ESPECIALLY
OVER THE MORE EXPOSED KEWEENAW...WHERE NAM/GFS SOUNDINGS INDICATE
MIXED LAYER BUILDING TO H85-H8 WITH WINDS OVER 35 KTS IN THE MIXED
LAYER.
QUIET WEATHER TUESDAY NIGHT AND WEDNESDAY AS DEEP SFC LOW SLOWLY
LIFTS TO JAMES BAY/HUDSON BAY. GRADIENT WEST FLOW STAYS OVER UPR
MICHIGAN...BUT WILL LIGHTEN ENOUGH ON WEDNESDAY TO RESULT IN LAKE
BREEZES. SLIM CHANCE THAT RESULTING LOW-LEVEL CONVERGENCE ADDED TO
WEAK H7-H5 FORCING FM SHORTWAVE DROPPING ACROSS ON PERIFERY OF DEEP
TROUGH ALOFT COULD TRIGGER A FEW SHOWERS/SPRINKLES INTERIOR CENTRAL.
DEEP MIXING TO H8 WILL LIMIT POTENTIAL THOUGH AS LOW-LEVEL RH VALUES
DROP OFF BLO 40 PCT. MAX TEMPS SHOULD PUSH INTO THE 50S INLAND AND
FALL BACK INTO THE 40S NEAR LK SUPERIOR ONCE LAKE BREEZE DEVELOPS.
THE FORECAST FOR THURSDAY INTO FRIDAY REMAINS UNCERTAIN. AT THE
LEAST...TEMPS WILL BE BLO NORMAL FOR MOST CWA...PERHAPS BY MORE
THAN 10-15F OVER THE NORTHERN CWA. ECMWF STILL SUPPORTS POTENTIAL
FOR ACCUMULATING SNOW...NOW MAINLY DELAYED UNTIL THURSDAY NIGHT
THROUGH FRIDAY AND POSSIBLY INTO FRIDAY NIGHT. LATEST UKMET ALSO
IN LINE WITH THE ECMWF IDEA. MEANWHILE...GFS AND GEM-NH STAY WITH
PROGRESSIVE IDEA INDICATING STRONG SHORTWAVE ROUNDING BASE OF DEEP
TROUGH STAYS SEPARATE ENOUGH FROM TROUGH FROM HUDSON BAY TO THE
NORTHERN PLAINS TO LIMIT PHASING. IF GFS THEME IDEA IS RIGHT...WOULD
SEE SETUP WITH MORE DIURNALLY DRIVEN MAINLY RAIN SHOWERS DUE TO
INSTABILITY ALOFT BENEATH THE TROUGH AXIS. IF THE ECMWF AND UKMET
ARE ON THE RIGHT TRACK...THEY INDICATE ENOUGH PHASING BTWN THE LARGE
SCALE TROUGHS TO DRAG A SFC LOW PRESSURE SYSTEM NORTHWARD OVER THE
CNTRL GREAT LAKES INTO TOWARD THE UPPER GREAT LAKES THURSDAY INTO
FRIDAY. WITH THAT SCNEARIO...WIDESPREAD RAIN AND SNOW THURSDAY
EVENING WOULD CHANGE TO SNOW THURSDAY NIGHT INTO MUCH OF FRIDAY AND
NORTHERLY FLOW WOULD ONLY BOOST THE SNOW OVER HIGHER TERRAIN AREAS
NEAR LK SUPERIOR. SNOW COULD BE PRETTY WIDESRPEAD AS PYTPE WITH H85
TEMPS DROPPING BLO -5C AND SINCE 1000-850MB THICKNESSES FALL BLO
1300M. PHASING SYSTEMS ARE ALWAYS TOUGH TO FORECAST. ADD TO THAT
FACT THAT WE ARE PUSHING INTO MIDDLE OF MAY AND IT MAKES IT REALLY
TOUGH TO SAY IF UKMET AND ECMWF SOLUTION WILL WORK OUT AS FORECAST.
SINCE ECMWF ENSEMBLE MEAN WOULD ALSO SUPPORT SIMILAR IDEA AND SOME
CANADIAN ENSEMBLES HAVE SHOWN THIS RECENTLY IT DOES SUGGEST THE IDEA
AT LEAST HAS SOME MERIT COMPARED TO JUST ONE ROUGE OPERATIONAL MODEL
RUN SHOWING A BIG STORM IN THE FAR REACHES OF THE EXTENDED.
ONCE THE SYSTEM OR JUST THE OPEN TROUGH MOVES BY...WEEKEND LOOKS
DRIER WITH GRADUAL WARMING TREND. DID NOT STRAY FROM CONSENSUS LOW
CHANCE POPS FOR NEXT WEEKEND ATTM.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 142 PM EDT MON MAY 12 2014
AFTER THE WIDESPREAD MODERATE RAINFALL...ABUNDANT LOW LEVEL MOISTURE WILL
REMAIN ACROSS THE REGION THIS AFTERNOON EVEN THOUGH THERE WILL LITTLE
ADDITIONAL RAIN. AS A RESULT...LIFR CONDITIONS WILL LINGER INTO THIS
EVENING. SHRA WILL REDEVELOP TONIGHT WITH LIFR/IFR CONDITIONS
PREVAILING. THERE COULD BE SOME TSRA AS WELL...PARTICULARLY AROUND
KSAW...BUT LIMITED CONFIDENCE IN TIMING/COVERAGE OF TSRA PRECLUDES A
MENTION IN THIS FCST. CONDITIONS WILL IMPROVE TO MVFR TUE MORNING
WITH LOW LEVEL DRYING IN THE WAKE OF A COLD FRONT. WEST WINDS WILL
ALSO BECOME GUSTY...ESPECIALLY AT CMX.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 504 AM EDT MON MAY 12 2014
EXPECT PERIOD OF STRONGER WINDS OVER LAKE SUPERIOR. APPROACHING LOW
PRESSURE SYSTEM RESULTS IN NORTHEAST WINDS INCREASING TO GALES BY
AFTN OVER WEST HALF OF LK SUPERIOR. WINDS TO 30 KTS OVER REST OF LK
SUPERIOR. STRONG WINDS DIMINISH BRIEFLY LATER THIS EVENING AND
OVERNIGHT TONIGHT AS THE LOW SLIDES ACROSS WESTERN LK SUPERIOR. ONCE
THE LOW MOVES NORTH OF THE LAKE ON TUESDAY MORNING...STRONG WEST
WINDS KICK UP. EXPECT THESE STRONG WESTERLIES...PROBABLY REACHING
GALES ON TUESDAY OVER NCNTRL LK SUPERIOR...TO SLOWLY FADE BLO 25 KTS
BY WEDNESDAY MORNING. WINDS REST OF THE WEEK WILL MAINLY BE BLO 20
KTS. HOWEVER...A LOW PRESSURE SYSTEM COULD IMPACT THE REGION LATE
THIS WEEK WITH WINDS OVER 25 KTS THURSDAY INTO FRIDAY. UNCERTAINTY
IS HIGH WITH THAT SYSTEM THOUGH...SO CURRENT FORECAST WILL ONLY CALL
FOR NORTHWEST TO 20 KTS AT THIS TIME.
&&
.HYDROLOGY...
ISSUED AT 504 AM EDT MON MAY 12 2014
WIDESRPEAD MODERATE TO HEAVY RAIN WILL AFFECT ALL OF UPR MICHIGAN
THROUGH EARLY THIS AFTN BEFORE DIMINISHING...THEN THERE MAY BE
ANOTHER PERIOD OF MODERATE RAINFALL TONIGHT. RAINFALL AMOUNTS MAY
EXCEED ONE INCH TODAY OVER PORTIONS OF WESTERN UPR MICHIGAN. RAIN
CHANCES DIMINISH FROM WEST TO EAST ON TUESDAY AS A FRONTAL BOUNDARY
EXITS THE REGION. RAINFALL WILL ONLY ADD TO THE ONGOING SNOWMELT AND
ALREADY HIGH FLOWS ON AREA RIVERS AND STREAMS. THE PRIMARY CHANGE TO
ONGOING HEADLINES WAS LAST EVENING...WHEN BASED ON EXPECTED
RAINFALL...WHICH LOOKS LIKE IT IS WORKING OUT...ADVISORIES WERE
UPGRADED TO WARNINGS FOR THE MICHIGAMME RIVER NEAR REPUBLIC AND
WITCH LAKE. THE WARNING FOR THE STURGEON RIVER NEAR CHASSELL AND THE
ADVISORY FOR THE STURGEON RIVER NEAR ALSTON CONTINUE...AS DOES THE
ADVISORY FOR THE MICHIGAMME RIVER DOWNSTREAM OF WAY DAM...TO THE
EAST OF CRYSTAL FALLS IN IRON COUNTY.
GIVEN THE RAINFALL THAT WILL AFFECT THE AREA THE NEXT 24-36
HOURS...RIVER LEVELS WILL KEEP RISING AND ADJUSTMENTS WILL LIKELY BE
NEEDED BASED ON LATEST TRENDS. ALL THIS WATER DUE TO THE SNOWMELT
AND THE RAINFALL WILL TAKE A WHILE TO WORK THROUGH THE RIVERS...SO
IT IS QUITE LIKELY THAT HIGHER RIVER FLOWS AND THE ASSOCIATED
ADVISORIES AND WARNINGS ON AREA RIVERS WILL CONTINUE THROUGH LATE
THIS WEEK...IF NOT INTO NEXT WEEKEND. THOSE LIVING NEAR
RIVERS...CREEKS...AND STREAMS SHOULD CONTINUE TO MONITOR THE LATEST
RIVER LEVELS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL MIDNIGHT EDT /11 PM CDT/ TONIGHT FOR LSZ162.
GALE WARNING UNTIL 11 PM EDT THIS EVENING FOR LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...JLB
MARINE...JLA
HYDROLOGY...JLA
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1220 PM CDT MON MAY 12 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 334 AM CDT MON MAY 12 2014
SHOWERS ARE PUSHING EAST OF OUR WEST CENTRAL WI COUNTIES EARLY THIS
MORNING WITH JUST A FEW SCATTERED SHOWERS ACROSS THE MN COUNTIES.
RAINFALL AMOUNTS OVERNIGHT FROM 1 TO 1.50 INCHES HAVE BEEN COMMON
ACROSS SOUTHERN MN AND ADJOINING AREAS OF WEST CENTRAL WI. RAINFALL
AMOUNTS DROP OFF TO AROUND A HALF INCH FROM WEST CENTRAL MN TO NW
WI.
THE DAY AHEAD WILL FEATURE A LOW PRESSURE SYSTEM MOVING SLOWLY
NORTHEAST FROM IA TO THE SOUTHERN TWIN CITIES METRO BY EARLY THIS
AFTERNOON. THE LOW SHOULD REACH FAR NORTHERN WI BY LATE THIS
EVENING. THERE IS PLENTY OF POTENTIAL FOR SEVERE STORMS TO DEVELOP
THIS AFTERNOON/EVENING IN THE VICINITY OF THE SURFACE LOW AND WARM
FRONT EXTENDING TO THE EAST. LIMITING FACTORS WILL BE THE EXTENSIVE
CLOUDINESS THAT WILL HOLD DOWN ON THE DESTABILIZATION. RAP DATA
SHOWS A WARM POCKET MOVING NORTHEAST FROM IA THIS MORNING BETWEEN
650-700MB. THIS IS SQUARELY OVER WEST CENTRAL WI EARLY THIS
AFTERNOON. LOW LEVEL LAPSE RATES SUFFER AS WELL AS SURFACE BASED
CAPE. HOWEVER...BY LATE IN THE AFTERNOON...SOUNDING DATA FOR KEAU
SHOWS THE POTENTIAL TO WARM ENOUGH TO GET PAST THE MID LEVEL WARM
POCKET. SURFACE BASED CAPE REACHES A LITTLE MORE THAN 2000 J/KG.
SHEAR IS ADEQUATE WITH 0-1KM REACHING 25 KNOTS WITH 0-6KM BETTER
THAN 45 KNOTS. 500MB WINDS ARE VERY IMPRESSIVE WITH A CORE OF 60-70
KNOT WINDS PROGGED ACROSS THE TWIN CITIES AND WEST CENTRAL WI THIS
AFTERNOON. OUR MPXWRF...THE HOPWRF AND THE SPCWRF START BREWING
TROUBLE ALONG OUR MN/WI BORDER AREA BY 21Z WITH THE HINT OF A FEW
SUPERCELLS ACROSS WEST CENTRAL WI INTO THE EARLY EVENING. GIVEN THE
LOW LCLS...SHEAR AND WARM FRONT...A TORNADO OR TWO CAN NOT BE RULED
OUT. IN FACT...THERE HAVE BEEN TORNADOES THE PAST TWO DAYS NEAR THE
SURFACE LOW AND WARM FRONT.
NORTHWEST WINDS WILL STRENGTHEN ACROSS THE FA TONIGHT IN THE WAKE OF
THE LOW PRESSURE SYSTEM. THIS WILL USHER IN MUCH COOLER AIR THAT
WILL BE WITH US FOR THE BALANCE OF THE WEEK AS A LARGE TROUGH ALOFT
DOMINATES ACROSS THE MISSISSIPPI VALLEY REGION.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 334 AM CDT MON MAY 12 2014
THE THEME FOR THE LONG TERM PERIOD IS DRY WEATHER FOR THE UPPER
MIDWEST. ALTHOUGH...IT WILL ALSO BE A COOL PERIOD MAINLY TUESDAY
THROUGH FRIDAY AS TEMPERATURES WILL RUN 10 TO 15 DEGREES BELOW
NORMAL.
PICKING UP TUESDAY MORNING...THE UPPER LEVEL TROUGH AXIS WILL BE
IN THE VICINITY OF THE WESTERN MN/EASTERN DAKOTAS BORDER. THE
SURFACE LOW WILL HAVE LIFTED UP INTO ONTARIO NORTH OF LAKE
SUPERIOR. THE NAM REMAINS STUBBORN IN HAVING THE MOVEMENT OF THE
LOW A TAD SLOWER/GIVEN ITS DEEPER SOLUTION WITH THE TROUGH MONDAY
NIGHT/...BUT IT HAS STARTED TO MOVE TOWARD THE GFS/EC SOLUTIONS.
PREFERRED A EC/GFS BLEND THAT HAS THE LOW QUICKLY MOVING NORTH.
THE UPPER TROUGH AND MOISTURE ON THE BACK SIDE OF THE LOW
WARRANTED THE MENTION OF POPS ACROSS THE NORTHERN PART OF THE
FA...BUT ANY PRECIPITATION WILL BE VERY LIGHT. WITH THE UPPER
TROUGH OVERHEAD...TEMPERATURES WILL BE HELD IN THE 50S DURING THE
DAY...AND WITH THE DEPARTING LOW NORTHWEST WINDS WILL BE BLUSTERY
AND MAKE FOR A COOL DAY. WINDS SHOULD SLACKEN AND SKY COVER BEGIN
TO BREAK UP TUESDAY EVENING. 850H TEMPS WILL FALL BELOW ZERO
OVERNIGHT AND GIVEN WEAKENING WINDS AND AND DIMINISHING SKY COVER
OVERNIGHT...TEMPERATURES BY EARLY WEDNESDAY MORNING WILL BE IN THE
30S ACROSS THE FA. LITTLE CHANGE IS EXPECTED WEDNESDAY AS THE
AMPLIFIED UPPER TROUGH AND CORE OF THE COOL AIR REMAINS OVERHEAD.
MEANWHILE...BOTH THE EAST COAST AND WEST COAST WILL HAVE HIGHLY
AMPLIFIED RIDGING AND WARM TEMPERATURES. SLIGHT CHANCE POPS DO
SHOW UP AGAIN WEDNESDAY AFTERNOON ACROSS THE WEST AS ADDITIONAL
MOISTURE ALOFT ROTATES SOUTH ON THE BACK SIDE OF THE UPPER TROUGH.
WOULD NOT BE SURPRISED IF LOW LEVEL DRY AIR PREVENTS ANYTHING FROM
REACHING THE GROUND. WEDNESDAY NIGHT WILL BE COLDER AS 850H TEMPS
DROP TO -2C TO -6C GENERALLY ACROSS THE FA. WIDESPREAD 30S ARE
EXPECTED WITH SOME SPOTS HITTING THE FREEZING MARK.
THE AMPLIFIED TROUGH WILL PUSH SLIGHTLY EAST AND BECOME A CLOSED
UPPER LOW OVER WISCONSIN THURSDAY NIGHT INTO FRIDAY SO
CYCLONICALLY CURVED FLOW MAY AGAIN PRODUCE VERY LIGHT PRECIP
THURSDAY AFTERNOON. THE POPS ASSOCIATED WITH THIS TROUGH DURING
THE MIDWEEK MAY BE OVERDONE BY THE LARGE SCALE SYNOPTIC
MODELS...HOWEVER...SO WHILE THERE ARE SOME POPS IN THE FORECAST
FOR THE MIDWEEK TIME FRAME...TOTAL AMOUNTS WILL BE UNDER A TENTH OF
AN INCH...AND WILL LIKELY BE ZERO FOR PARTS OF THE AREA.
WE`LL SEE THE CORE OF THE COOL AIR ALOFT PUSH EAST AT THE START OF
THE WEEKEND AS THE WESTERN CONUS RIDGE STARTS PUSHING INTO THE
CENTER OF THE COUNTRY BY SUNDAY. BESIDES A COOL START...THE
WEEKEND LOOKS DRY...PARTLY CLOUDY...AND WARMER THAN THE COLD MIDWEEK
AHEAD. BEYOND THE WEEKEND...THE RIDGE AXIS WILL PUSH OVER OUR AREA
EARLY NEXT WEEK AND TEMPERATURES WILL CONTINUE TO WARM.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1203 PM CDT MON MAY 12 2014
WEAK SFC LOW THAT WAS ACROSS EC MN THIS MORNING HAS SHIFTED
FURTHER TO THE NE AND W/NW WINDS HAVE NEARLY MOVED THRU THE METRO
AREA. ONLY AREAS WITH A SOUTHERLY WIND FLOW WAS ACROSS WC WI/SE MN
WHERE THE BEST CHC OF ANY TSRA ACTIVITY IN THE NEXT 6 TO 12 HRS.
IN ADDITION TO THE WINDS SHIFTING TO THE W/NW...CIGS DROP TO
IFR/LIFR AND VSBYS DROP WITH DRIZZLE/-RA. MORE PERSISTENT SHRA
WERE ACROSS SD/ND EARLY THIS AFTN. WILL CONTINUE CHC POPS...BUT IT
WILL LIKELY BE MORE SCATTERED IN NATURE WITH A BETTER CHC OF
WIDESPREAD ACTIVITY ACROSS WC MN DURING THE LATE AFTN AS THE MAIN
UPPER LOW MOVES ACROSS THE UPPER MIDWEST. CIGS/VSBYS WILL REMAIN
IFR/LIFR FOR THE BULK OF THE AFTN/EVENING ACROSS MN...WITH WC WI
HAVING THE BEST CHC OF MVFR CIGS AND TSRA. CONFIDENCE IN TSRA
REMAINS LOW FOR ALL MPX TAF SITES WITH THE EXCEPTION OF KEAU WHERE
VCTS LOOKS REASONABLE FOR THIS AFTN/EVENING. WILL UPDATE KEAU AS
PER LATEST RADAR AND ADJUST AS NEEDED. WINDS WILL REMAIN FROM THE
NW/WNW THRU THE PERIOD ACROSS MN...WITH WINDS SHIFTING TO THE W/NW
AT KRNH BY EARLY/MID AFTN...AND AT KEAU AFT 23Z.
KMSP...
WINDS HAVE SHIFTED TO THE NW IN THE LAST HR...WHICH BASICALLY
CAUSES ANY CHC/S OF TSRA ALMOST NIL THIS AFTN WITH ONLY A SMALL
CHC BASED ON MID LEVEL LAPSE RATES IN FAR EC MN. WILL LEAVE OUT
VCTS ATTM...BUT WILL NEED TO SEE HOW CONVECTION DEVELOPS IN NC IA
THIS AFTN. OTHERWISE...IFR CIGS WILL CONTINUE WITH VSBYS SLOWLY
IMPROVING LATER THIS AFTN/EVENING AS WINDS INCREASE FROM THE
WNW/NW AND BECOME GUSTY. SOME INSTABILITY SHRA ARE POSSIBLE
TUESDAY AFTN...BUT NOT CONFIDENT ENOUGH TO WARRANT ANYTHING MORE
THAN VCSH AFT 18Z. CIGS SHOULD BEGIN TO LIFT TUESDAY
MORNING...WITH VFR CIGS DURING THE AFTN.
/OUTLOOK FOR KMSP/
TUE AFTN...VFR. MVFR POSSIBLE IN -SHRA. WINDS W-NW 15-20 KTS.
WED...VFR. WINDS W 5-15 KTS.
THU...VFR. WINDS N/NE 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...RAH
LONG TERM...SPD
AVIATION...JLT
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1239 PM CDT Mon May 12 2014
.SHORT TERM: (Today and Tonight)
Issued at 330 AM CDT Mon May 12 2014
Main forecast issues for today are the probability of thunderstorms
and any severe potential, as well as just how warm it may get.
Current thinking is there should be a gradual upswing in convection
as the day progresses, primarily during the later half of the
afternoon. It appears that northeast Missouri will be the area we
will have to watch most closely through mid morning. Two things to
key an eye on - an outflow boundary pushing southeastward across
eastern Iowa as a focus for additional thunderstorms, and also a
cluster of thunderstorms across eastern Kansas just southwest of
Kansas City and if they will hold together as they move northeastward.
Otherwise I think that there will be a general decrease in the
convective cloud debris during the morning, which given the mild
early morning temperatures should allow for a quick warm-up by
early afternoon. The convection allowing models and more
specifically the HRRR is suggesting that by mid morning, isolated
showers or thunderstorms could develop just about anywhere within
the CWA, but most favored across southeast Missouri and southern
Illinois. The main action still looks like the later half of the
afternoon. The warm sector air mass ahead of the cold front will
become quite unstable by mid-late afternoon with SBCAPE in excess
of 2000 J/KG and little CIN. Expecting numerous thunderstorms to
develop across western Missouri into central and northeast
Missouri. Deep layer shear of 20-30 kts and the anticipated CAPE
would support a few severe storms capable of large hail and
damaging winds from the afternoon into about mid-evening. The
front moves through all but the far eastern sections of the CWA
tonight accompanied by widespread showers and thunderstorms and
ushering much cooler air into the region in its wake. It also
appears that there will be an increasing amount of post-frontal
showers overnight immediately in the cool air in response to large
scale forcing.
Glass
.LONG TERM: (Tuesday through Sunday)
Issued at 330 AM CDT Mon May 12 2014
This marks the beginning of a cooler than normal period with a
slow-moving and deep upper trof dominating the region through the
week. The front will quickly exit the remainder of the CWA early
Tuesday morning with post-frontal showers impacting eastern
Missouri and southwest Illinois in the morning and exiting by
early-mid afternoon. Highs on Tuesday will be around 20 degrees
cooler than today. A strong short-wave and possibly upper low will
then migrate through the base of the deep trof from the southern
Plains and into the mid MS valley Tuesday night-Wednesday night.
More reminiscent of Fall or early Spring, large scale ascent with this
system should produce a large area of showers or rain spreading
into the area late Tuesday night into Wednesday. Its northward
extent and longevity is all dependent on the strength of the
system, and NAM featuring a closed low and large deformation zone, has
the greatest northward push and keeps precipitation well into
Wednesday night. Regardless the precipitation and accompanying
overcast low clouds will keep temperatures well below average on
Wednesday. We could continue to see a periodic shower threat
through the end of the week as we get into deeper cyclonic flow on
the backside of the slow-moving deep upper trof. Temperatures will
remain below average into at least Friday.
Glass
&&
.AVIATION: (For the 18z TAFs through 18z Tuesday Afternoon)
Issued at 1227 PM CDT Mon May 12 2014
Specifics for KSTL, KSUS, KCPS, KUIN, KCOU: An approaching cold
front will likely bring a period of SHRA/TSRA to all TAF sites
during the late afternoon and evening. A stray shower or
thunderstorm is possible early this afternoon, but the main
precipitation threat is with the front. A broad area of MVFR cigs
is located behind the front, and these clouds will remain over the
terminals even after the front has moved eastward and
precipitation has ended. Initially south to southwest winds will
become northwesterly after fropa.
Kanofsky
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BISMARCK ND
329 PM CDT MON MAY 12 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 329 PM CDT MON MAY 12 2014
MAIN FORECAST ISSUE IN THE SHORT TERM PERIOD WILL BE WINDS ACROSS
THE AREA THROUGH THE REMAINDER OF THE AFTERNOON...PRECIPITATION
ENDING IN THE EAST THIS EVENING AND OVERNIGHT TEMPERATURES.
CURRENTLY...SURFACE LOW PRESSURE OVER SOUTHEAST MINNESOTA WITH AN
INVERTED TROUGH NORTH THROUGH NORTHERN MINNESOTA. THE DEFORMATION
ZONE ASSOCIATED WITH THIS LOW PRESSURE SYSTEM WILL CONTINUE TO
TRACK EAST THIS EVENING AND RAIN SHOWERS WILL END OVER THE JAMES
RIVER VALLEY THIS EVENING.
LATEST RAP SOUNDINGS INDICATE THAT AREAS ALONG AND WEST OF
HIGHWAY 83 WILL SEE DIMINISHING WINDS THIS EVENING. IT MAY BE
BREEZY THROUGH AROUND 9 PM BUT WINDS SHOULD REMAIN BELOW ADVISORY
LEVELS. WINDS COULD HOLD ON OVER EASTERN PORTIONS OF CENTRAL NORTH
DAKOTA WITH KJMS AND CARRINGTON 19 UTC BUFR SOUNDINGS INDICATING
THE BOUNDARY LAYER REMAINING LIFTED WITH 40 KNOT WINDS AVAILABLE
TO WORK DOWN. GRADIENT WINDS WILL BE STRONGEST HERE ALSO...CLOSER
TO THE SURFACE LOW. WILL KEEP THE ADVISORY GOING AND EVENING SHIFT
WILL NEED TO LOOK INTO POSSIBLY EXTENDING EASTERN PORTIONS OF THE
ADVISORY.
CONVECTIVE CUMULUS FLATTENING OUT SHOULD SLOWLY DISSIPATE THIS
EVENING. THUS MOSTLY CLEAR SKIES ARE EXPECTED BY MORNING. WILL SEE
LOWS IN THE LOW TO MID 30S MOST AREAS. WINDS SHOULD REMAIN AT 5 TO
10 MPH OVERNIGHT...KEEPING TEMPERATURES FROM FALLING INTO THE
20S. MID 30S ARE EXPECTED OVER EASTERN PORTIONS OF CENTRAL NORTH
DAKOTA WHERE WINDS AND CLOUDS HANG ON LONGER TONIGHT.
TUESDAY WILL BE MUCH NICER THAN TODAY OVER THE JAMES RIVER
VALLEY...WITH NO RAIN...LESS WIND AND MORE SUN. ELSEWHERE...TUESDAY
IS EXPECTED TO SIMILAR TO TODAY...BUT WITH A LITTLE LESS CLOUDS
AND WINDS AND A LITTLE MORE SUNSHINE.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 329 PM CDT MON MAY 12 2014
TROUGH MOVES EAST WEDNESDAY WITH NORTHWEST FLOW ALOFT DEVELOPING AND
PERSISTING THROUGH THE FIRST HALF OF NEXT WEEKEND. EMBEDDED WAVE IS
DEPICTED TO MOVE THROUGH SOMETIME THURSDAY NIGHT OR FRIDAY BRINGING
A CHANCE FOR SHOWERS TO THE LOCAL AREA. OTHERWISE THE REST OF THE
WORK WEEK APPEARS MAINLY DRY.
12Z GFS/ECMWF SHOW A SHORT WAVE RIDGE SATURDAY NIGHT FOLLOWED BY A
MORE ACTIVE FLOW SUNDAY INTO MONDAY AHEAD AND ALONG A DEVELOPING
TROUGH ORIGINATING OVER THE PACIFIC NORTHWEST AND PROGRESSING
EASTWARD. MILDER TEMPERATURES OVER THE WEEKEND AS WELL...HELPING TO
INCREASE THE POTENTIAL FOR THUNDERSTORMS SUNDAY-MONDAY. UNCERTAINTY
STILL HIGH SO WILL LEAVE OUT OF THE FORECAST AT THIS TIME.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 329 PM CDT MON MAY 12 2014
MVFR CEILINGS WILL CONTINUE THROUGH THE AFTERNOON AT KJMS...WITH
CEILINGS EXPECTED TO LIFT ABOVE MVFR MONDAY EVENING. ELSEWHERE VFR
CEILINGS ARE EXPECTED THROUGH THE PERIOD. LOW VFR CEILINGS WILL
CONTINUE TO LIFT AND DISSIPATE THIS EVENING...BECOMING MOSTLY
CLEAR OVERNIGHT. STRONG NORTH WINDS THROUGH THE AFTERNOON WILL
DIMINISH TONIGHT AND PICK UP AGAIN ON TUESDAY BUT ARE NOT EXPECTED
TO BE AS STRONG...WITH MORE OF A NORTHWEST DIRECTION. WE MAY SEE
A PERIOD OF LOW VFR CEILINGS IN CUMULUS EARLY TUESDAY
AFTERNOON...JUST BEYOND THE TAF PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 7 PM CDT /6 PM MDT/ THIS EVENING FOR
NDZ002>005-010>013-018>023-025-031>037-040>048-050-051.
&&
$$
SHORT TERM...TWH
LONG TERM...NH
AVIATION...TWH
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
109 PM CDT MON MAY 12 2014
.AVIATION...
MVFR CONDITIONS ARE EXPECTED FOR THIS FORECAST PERIOD AND
WIDESPREAD DISRUPTIONS ARE EXPECTED THIS AFTERNOON AND EVENING DUE
TO THUNDERSTORM ACTIVITY AFFECTING THE AREA.
A COLD FRONT CONTINUES TO APPROACH FROM THE NORTHWEST. AT 1730Z...
THE FRONT WAS LOCATED ALONG A LINE FROM JACKSBORO TO JUST WEST OF
COMANCHE AND WAS MOVING EAST AROUND 14KTS. HOWEVER... THE SPEED OF
THE FRONT MAY INCREASE DEPENDING ON THE INTENSITY OF THE CONVECTION
ALONG THE BOUNDARY. WINDS WILL CONTINUE TO BE GUSTY BUT WILL SHIFT
TO THE NORTH BEHIND THE FRONT.
STORMS HAVE ALREADY BEGUN TO DEVELOP ALONG THE FRONT BUT CONVECTION
WILL LIKELY AFFECT AREAS AHEAD OF THE PRIMARY WIND SHIFT.
CONVECTION WILL BEGIN TO AFFECT DFW TAF SITES AROUND 20Z AND WACO
AROUND 22Z. SOME OF THE STORMS MAY BE MARGINALLY SEVERE WITH A
DAMAGING WIND THREAT BEING THE PRIMARY CONCERN. WINDS WILL LIKELY
SHIFT TO THE NORTHWEST WITH CONVECTION ALONG THE FRONT. AMENDMENTS
WILL LIKELY BE REQUIRED OVER THE NEXT COUPLE OF HOURS AS
CONVECTION MOVES EAST TO ADDRESS WINDS/TIMING OF TSTMS.
WHILE MVFR CONDITIONS ARE FORECAST...IFR VIS MAY BRIEFLY AFFECT
TAF SITES DURING CONVECTION. IT WAS NOTED DURING THE MORNING
CONVECTION THAT AFFECTED THE DFW METRO TAF SITES THAT THE RAINFALL
APPEARED LIGHT ON RADAR...BUT RESULTED IN LOW VIS AND HIGHER
RAINFALL AMOUNTS THAN EXPECTED.
&&
.UPDATE...
CURRENT FORECAST IS IN GOOD SHAPE AND HAVE ONLY MADE SOME COSMETIC
CHANGES TO THE HOURLY DATA AND MORNING POPS. LATEST SURFACE
ANALYSIS INDICATES THAT THE COLD FRONT IS LOCATED ALONG A LINE
ACROSS CENTRAL OKLAHOMA INTO NORTHWEST TEXAS BETWEEN BOWIE AND
WICHITA FALLS SOUTHWARD TO BRECKENRIDGE. AHEAD OF THE COLD FRONT
AN AREA OF SHOWERS AND THUNDERSTORMS INITIATED ON WHAT APPEARS TO
BE AN INITIAL WAVE OF FORCING OR A SOUTHWARD PROPAGATING GRAVITY
WAVE. EITHER WAY...AMDAR SOUNDING DATA FROM DFW AIRCRAFT INDICATE
THAT STRONG CAPPING INVERSION NOTED ON 12Z FWD SOUNDING WAS ALL
BUT COMPLETELY ERODED IN ABOUT 45 MINUTES. THIS INITIAL WAVE OF
ACTIVITY HAS FAILED TO ORGANIZE OR REALLY TAKE OFF IN INTENSITY
WHICH HAS LEFT THE LOW LEVEL WINDS AND MOISTURE IN PLACE BEHIND
IT. THIS WILL LIKELY HELP TO INITIATE MORE ROBUST THUNDERSTORM
ACTIVITY OVER THE NEXT FEW HOURS AS THE FRONT CONTINUES TO MOVE
SOUTH. LATEST OBJECTIVE ANALYSIS ACROSS NORTH TEXAS SHOWS AROUND
2000 J/KG OF SURFACE BASED INSTABILITY SOUTH/EAST OF THE FRONT
WHERE THE SUN HAS COME OUT A BIT WITH LITTLE INHIBITION LEFT.
EXPECT THUNDERSTORMS TO BECOME MORE NUMEROUS IN COVERAGE THROUGH
EARLY AFTERNOON.
THE SEVERE THREAT REMAINS ACROSS NORTH TEXAS...ESPECIALLY GIVEN
THE STRONG INSTABILITY...HOWEVER DEEP LAYER SHEAR ISNT ALL THAT
STRONG SO MULTICELL CLUSTERS ARE EXPECTED. SOME SEVERE WIND GUSTS
WOULD BE POSSIBLE ALONG WITH SEVERE HAIL. THE MORE SIGNIFICANT
THREAT WILL BE FOR VERY HEAVY RAINFALL AND FLASH
FLOODING...ESPECIALLY ACROSS THE EASTERN COUNTIES WHERE THE FRONT
IS EXPECTED TO SLOWLY MOVE THROUGH TONIGHT. SOME AREAS COULD PICK
UP IN EXCESS OF 3 INCHES OF RAIN IN A SHORT PERIOD OF TIME WITH
ADDITIONAL RAINFALL PERSISTING INTO TONIGHT.
DUNN
&&
.PREV DISCUSSION... /ISSUED 437 AM CDT MON MAY 12 2014/
THE POTENT UPPER LEVEL LOW OVER THE FOUR CORNERS THAT WAS
RESPONSIBLE FOR SNOW IN DENVER YESTERDAY WILL EJECT NORTHEAST OUT
INTO THE PLAINS TODAY...BUT ADDITIONAL UPPER ENERGY WILL DROP INTO
THE BASE OF A DEEPENING LONGWAVE TROUGH TODAY. THIS UPPER TROUGH
WILL ENGULF THE CENTRAL US BY TOMORROW...A PATTERN THAT IS VERY
UNUSUAL FOR MID MAY. THIS SYSTEM HAS TAPPED INTO A CANADIAN
AIRMASS AND HAS SENT AN UNSEASONABLY STRONG COLD FRONT BARRELING
SOUTH. AT 4AM...THIS FRONT WAS LOCATED JUST SOUTH OF LUBBOCK TO
NEAR VERNON TO EL RENO OKLAHOMA AND WAS MOVING SOUTHEAST AT 15 TO
20MPH. THE FRONT IS AHEAD OF MOST MODEL PROJECTIONS...WHICH IS
NOT SURPRISING GIVEN THE COLD AIR BEHIND IT. THE RAP HAS A GOOD
HANDLE ON THE FRONT/S SPEED AND IT WILL BE USED FOR TIMING.
THE FRONT WILL ARRIVE INTO THE NORTHWEST CWA BY MID-MORNING AND
CONTINUE TO TRACK SOUTHEAST...BUT SLOW DOWN A BIT DUE TO DAYTIME
HEATING. THE FRONT SHOULD REACH A SHERMAN TO DFW TO COMANCHE LINE
BY MID-AFTERNOON. THE AIRMASS AHEAD OF THE FRONT WILL BE WARM AND
MOIST...WITH SEVERAL DAYS OF SOUTHERLY FLOW NOW BRINGING
PRECIPITABLE WATER VALUES UP TO 1.75 TO 2 INCHES. SURFACE BASED
CAPE WILL PEAK AROUND 2000-2500 J/KG THIS AFTERNOON AS TEMPS WARM
INTO THE MID 80S. DAYTIME HEATING AND FORCING FOR ASCENT FROM THE
UPPER LEVEL TROUGH WILL LIFT/ERODE THE WEAK CAPPING
INVERSION...AND THUS CONVECTION WILL INCREASE IN COVERAGE ALONG
THE FRONT BY LATE MORNING. BULK LAYER SHEAR IS FAIRLY WEAK...ON
THE ORDER OF 25KT...SO MULTICELLULAR CONVECTIVE MODES ARE
EXPECTED. GIVEN THE HIGH INSTABILITY AND WEAK SHEAR...SOME SEVERE
WIND/HAIL REPORTS ARE POSSIBLE TODAY WITH THE STRONGEST STORMS.
CONVECTION ALONG THE FRONT WILL LIKELY CONGEAL INTO A SOLID LINE
OF THUNDERSTORMS BY MID-AFTERNOON...WITH THE LINE CONTINUING TO
GROW UPSCALE INTO A FORMIDABLE LINEAR MCS BY THE EVENING HOURS.
MCS PROPAGATION VECTORS AND DIFFLUENT THICKNESS FIELDS ALOFT
SUGGEST THAT THE MOVEMENT OF THIS SYSTEM WILL REMAIN FAIRLY
SLOW...LIKELY LESS THAN 10-15MPH. THIS FORWARD SPEED SHOULD IN
THEORY LIMIT THE DAMAGING WIND THREAT THIS EVENING OVER THE
SOUTHEAST HALF OF THE CWA...BUT WILL RESULT IN ENHANCED RAINFALL
TOTALS. THE MCS WILL LIKELY HAVE SLOWER WEST TO EAST MOVEMENT THAN
NORTH TO SOUTH...AND THUS THE ORIENTATION OF THE LINE SUGGESTS
THAT EASTERN ZONES WILL HAVE A GREATER RISK FOR PROLONGED HEAVY
RAINFALL. EXPECT THE LINE TO PUSH THROUGH THE SOUTHWEST ZONES
FAIRLY QUICKLY...LIKELY REACHING A LAMPASAS TO WACO LINE BY 6 PM.
A TIGHT RAINFALL GRADIENT IS FORECAST OVER THE CWA WITH LESS THAN
A HALF INCH EXPECTED OVER THE NW ZONES...TO 1-2 INCHES IN A BAND
FROM THE SHERMAN AREA TO THE METROPLEX TO COMANCHE...AND 2-3
INCHES SOUTH AND EAST OF A PARIS TO GREENVILLE TO HILLSBORO LINE.
THIS LATTER REGION WAS THE SAME AREA THAT RECEIVED A SWATH OF 2-4
INCHES OF RAIN THURSDAY AND SOILS ARE ALREADY SATURATED. THUS A
FLASH FLOOD WATCH WAS ISSUED FOR LOCATIONS ALONG AND SOUTHEAST OF
A BONHAM TO DALLAS TO TEMPLE LINE. WHILE WE DONT EXPECT MOST OF
DALLAS AND COLLIN COUNTIES TO RECEIVE MORE THAN 2 INCHES...GIVEN
THE URBAN DEVELOPMENT THERE AND THE FACT THAT THE SOUTHEAST PARTS
OF THESE COUNTIES DID SEE OVER 4 INCHES...FELT IT WAS BEST TO
INCLUDE THEM. FARTHER SOUTH...FROM WACO TO ATHENS...LESS RAIN FELL
IN THIS AREA LAST THURSDAY...BUT QUICK TOTALS OF 2-3 INCHES ARE
POSSIBLE THIS EVENING. FOR WACO/TEMPLE/KILLEEN ONLY AROUND 2
INCHES ARE FORECAST...BUT AGAIN URBAN INFRASTRUCTURE MAY
EXACERBATE ANY FLOODING...SO THEY WERE INCLUDED IN THE WATCH TOO.
BECAUSE THE UPPER LEVEL TROUGH WILL BE SLOW TO MOVE
EAST...CONTINUED SOUTHERLY FLOW ALOFT BEHIND THE FRONT/LINE OF
STORMS WILL OCCUR THIS EVENING. THUS THE LINE OF STORMS WILL
LIKELY BE SUCCEEDED BY A FEW HOURS OF STEADY LIGHT TO MODERATE
STRATIFORM RAINS...ESPECIALLY ACROSS THE WATCH AREA. THIS ACTIVITY
SHOULD END FROM NORTHWEST TO SOUTHEAST LATE TONIGHT...BUT MAY
LINGER OVER THE SOUTHEAST ZONES INTO TUESDAY MORNING. TUESDAY
SHOULD BE DRY FOR THE REMAINDER OF THE AREA WITH MOSTLY CLOUDY AND
COOL CONDITIONS AS COOLER AIR POURS INTO THE REGION BEHIND THE
FRONT. FORECAST HIGH TEMPS MAY BE TOO WARM...BUT IT WOULD ONLY
TAKE AN HOUR OR TWO OF AFTERNOON MAY SUNSHINE TO WARM US INTO THE
MID 60S...SO STAYED CONSERVATIVE THERE.
THE STRONGEST UPPER LEVEL FORCING WILL CROSS THE REGION TUESDAY
EVENING BUT THE AIRMASS WILL BE PRETTY WORKED OVER. HOWEVER THIS
FORCING SHOULD RESULT IN SCATTERED ELEVATED SHOWERS AND A FEW
STORMS OVER THE REGION AND SHOULD SQUEEZE OUT ANOTHER TENTH TO
QUARTER INCH OF RAINFALL. HAVE BUMPED POPS UP TUESDAY NIGHT AS
MODEL GUIDANCE HAS COME INTO BETTER AGREEMENT ON THIS ROUND.
OTHERWISE THE REMAINDER OF THE FORECAST LOOKS QUIET AND VERY NICE
FOR MID TO LATE MAY. DRY NORTHWESTERLY FLOW ALOFT WILL PREVAIL
THROUGH THE WEEKEND LEADING TO CLEAR SKIES AND LIGHT WINDS. GOOD
RADIATIONAL COOLING WEDNESDAY NIGHT WILL SEND LOW TEMPS DOWN INTO
THE 40S AREA WIDE...AND WACO MAY BREAK ITS RECORD LOW OF 46. HIGHS
IN THE UPPER 60S ARE EXPECTED THURSDAY...BUT TEMPS SHOULD WARM
INTO THE 70S FRIDAY AND THE 80S BY THE WEEKEND. DRY WEATHER WILL
CONTINUE INTO NEXT WEEK WITH TEMPS WARMING TO ABOVE NORMAL.
TR.92
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 83 54 66 51 68 / 90 80 20 40 10
WACO, TX 87 57 65 51 69 / 70 100 40 60 10
PARIS, TX 84 56 63 51 64 / 70 90 20 50 20
DENTON, TX 80 52 65 49 68 / 80 70 20 40 10
MCKINNEY, TX 83 53 64 50 68 / 90 80 20 40 10
DALLAS, TX 84 55 65 52 68 / 90 80 20 50 10
TERRELL, TX 85 57 64 51 67 / 70 90 20 50 20
CORSICANA, TX 86 59 64 52 67 / 60 100 40 60 20
TEMPLE, TX 87 58 64 52 69 / 50 100 50 60 10
MINERAL WELLS, TX 80 50 66 47 71 / 70 60 20 30 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM 4 PM CDT THIS AFTERNOON THROUGH LATE
TONIGHT FOR TXZ094-095-104>107-119>123-134-135-145>148-158>162-
174-175.
&&
$$
/
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1250 PM CDT MON MAY 12 2014
.AVIATION...
/18Z TAFS/
A cold front has moved into the southeast half of the CWA this
afternoon, with showers and thunderstorms developing in the warm
sector. The greatest threat for thunderstorms will be from the
KBWD, to KBBD, to KJCT terminals. VCTS remarks were included
through early evening in these areas with winds eventually
shifting to the northwest as the front moves slowly south. Behind
the front, winds will remain from the northwest at near 15 kts,
gusting up to 25 kts at times. MVFR ceilings will continue for a
bit longer at KABI but VFR conditions will persist at KSJT.
More widespread rain will be possible over the southeast terminals
overnight, mainly at KJCT. The NAM model is suggesting very low
clouds continuing across the southeast through the period but the
GFS looks more reasonable, keeping prevailing ceilings above 3000
ft.
Johnson
&&
.PREV DISCUSSION... /ISSUED 1131 AM CDT MON MAY 12 2014/
UPDATE...
The cold front is just a bit ahead of schedule, currently
bifurcating the CWA from southwest to northeast (Ozona, to Paint
Rock, to Cross Plains). Winds are from the north at 15-20 mph in
the wake of this front. Temperatures remain in the 60s in areas
that experienced the frontal passage early this morning, but have
only regressed into the mid 70s at locations where the front as
arrived in the past 1-2 hours. I lowered max temps across the Big
Country and western Concho Valley a few degrees with only minor
tweaks needed elsewhere. Other minor changes were made to the
dewpoint/wind grids to account for the faster cold front.
Convection is just now beginning to ramp up in the warm sector,
primarily from Paint Rock to Brownwood. The EMC RAP meso-analysis
provided by the SPC indicates MLCAPE values of 2000-3000 J/kg
across the area with little/no CINH. Effective shear has
increased over the past few hours and should be supportive of
organized convection this afternoon and early this evening. Steep
mid-level lapse rates will promote hail growth, however, the drier
air behind this front may push the severe threat east of the area
by early evening. During the late afternoon and evening hours,
this convection should grow upscale, decreasing the severe threat
and becoming more of a heavy rain producer.
PREV DISCUSSION... /ISSUED 634 AM CDT MON MAY 12 2014/
AVIATION...
/12Z TAFS/
Stratus will remain over the Heartland and Northwest Hill Country
through mid morning and then will dissipate. Going with MVFR
CIGS at the KJCT and KBBD terminals until 16Z. Mainly VFR
conditions are expected the rest of the TAF forecast. Isolated to
scattered thunderstorms will be possible east of an Abilene to San
Angelo line mainly this afternoon and tonight. Storms may even be
more numerous by tonight east of a Coleman to Junction line. The
models are developing an MCS along a cold front by 06Z Tuesday and
moving it slowly east into central Texas. However, confidence is
only high enough to add VCTS to the terminals through 02Z Tuesday.
Winds will be south and then become north as cold front moves
through West Central Texas today and this evening.
PREV DISCUSSION... /ISSUED 442 AM CDT MON MAY 12 2014/
SHORT TERM...
(Today and Tonight)
WV imagery this morning was showing and a strong upper level
trough over the central and southern Rockies with a mid level
speed max of 50 to 70 knots rotating out in the Plains. Upper
level flow has backed to southwest over Texas. Also, a lot mid and
upper subsidence evident which is still resulting in a strong
cap over West Central Texas. At the surface, a cold front was
located along a Quanah to Seminole line. A dryline extended south
along a Wink to Sanderson line. Not much happening yet convection
wise as low level inhibition and cap is still holding strong. A
few showers have developed just behind the cold front across
northwest Texas. The airmass was very moist across our area with
southerly flow and dewpoints in the mid to upper 60s.
For today, the chance of showers and thunderstorms will increase
mid morning through the afternoon across mainly the eastern half
of the CWFA. The cold front will continue southeast into West
Central Texas and will probably slow its forward speed. Scattered
showers and thunderstorms will develop along and behind the front
as elevated instability erases the cap. The HRRR convective
allowing model is showing best coverage of activity east of an
Abilene to San Angelo line. The combination of good instability in
the warm sector and weak 0-6KM shear of 25 to 30 knots will result
in multicell storms with possible brief supercell structures. A
few strong to severe storms are possible across mainly the
Heartland and Northwest Hill Country. The main hazards will be
large hail, damaging winds and dangerous cloud to ground
lightning. Going with mainly chance to slight chance POPS for
today. Temperatures will be cooler with highs in the 80s.
For tonight, There will be a chance of showers thunderstorms
across much of our area with better coverage of storms east of a
Coleman to Sonora line. a few storms may be severe. The main
hazards will be large hail, damaging winds and dangerous cloud to
ground lightning mainly before 06Z Tuesday. The bigger focus will
be the potential for locally heavy rainfall across the Heartland
and Northwest Hill Country, due to good low level southerly flow.
moisture flux convergence along a slow moving cold front, PWAT
values of 1.5 to 1.75 inches and in the RRQ of highly amplified
250MB jet. Rainfall amounts of 1 to 2 inches with locally heavy
amounts are possible along and east of a Brownwood to Junction
line. Also, going with LKLY to CAT POPS across the southeast CWFA.
LONG TERM...
(Tuesday through next Monday)
The cold front will be well south of the area early Tuesday
morning, with the upper level trough axis over New Mexico.
Showers and thunderstorms may be ongoing across far southeast
sections early Tuesday morning but will move east of the area by
mid to late morning. Additional showers and isolated thunderstorms
will be possible across much of the area during the day as lift
increases ahead of the approaching upper trough. Moisture will be
limited, so precipitation is expected to be light, with most areas
seeing one tenth inch or less of rainfall. It will be considerably
cooler on Tuesday with highs well below normal for this time of
year. NAM guidance looks too cool with highs in the upper 50s, so
went with a GFS/NAM blend, which looks more reasonable with highs
topping out in the lower 60s. Lingering showers will be possible
Tuesday evening over southeast sections, otherwise dry conditions
are expected overnight with clearing skies, as drier air filters
in behind the departing upper trough. Temperatures will be very
chilly Wednesday night with overnight lows in the lower and middle
40s.
Dry and cool weather will continue on Wednesday with sunny skies,
light winds and highs in the lower 70s. Another cool night is in
store Wednesday night with low temperatures again in the 40s. Will
maintain a dry forecast Thursday into next weekend with a warming
trend through the period. Northwest flow aloft is expected through
Saturday, with a short wave ridge overspreading the Plains on
Sunday. High temperatures will warm from the mid 80s late week, to
the upper 80s and lower 90s by the end of the weekend. Expect
overnight lows in the 50s, warming into the 60s through the
period.
FIRE WEATHER...
Elevated fire weather conditions will be possible across much of
West Central Texas Wednesday through Friday, as minimum relative
humidity values drop to 15 to 20 percent, but 20 foot winds
generally remain below 15 mph.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 50 63 44 71 45 / 20 20 10 0 0
San Angelo 52 62 42 72 42 / 20 20 10 0 0
Junction 57 64 46 72 41 / 70 40 20 0 0
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
Aviation: Johnson
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1131 AM CDT MON MAY 12 2014
.UPDATE...
The cold front is just a bit ahead of schedule, currently
bifurcating the CWA from southwest to northeast (Ozona, to Paint
Rock, to Cross Plains). Winds are from the north at 15-20 mph in
the wake of this front. Temperatures remain in the 60s in areas
that experienced the frontal passage early this morning, but have
only regressed into the mid 70s at locations where the front as
arrived in the past 1-2 hours. I lowered max temps across the Big
Country and western Concho Valley a few degrees with only minor
tweaks needed elsewhere. Other minor changes were made to the
dewpoint/wind grids to account for the faster cold front.
Convection is just now beginning to ramp up in the warm sector,
primarily from Paint Rock to Brownwood. The EMC RAP meso-analysis
provided by the SPC indicates MLCAPE values of 2000-3000 J/kg
across the area with little/no CINH. Effective shear has
increased over the past few hours and should be supportive of
organized convection this afternoon and early this evening. Steep
mid-level lapse rates will promote hail growth, however, the drier
air behind this front may push the severe threat east of the area
by early evening. During the late afternoon and evening hours,
this convection should grow upscale, decreasing the severe threat
and becoming more of a heavy rain producer.
&&
.PREV DISCUSSION... /ISSUED 634 AM CDT MON MAY 12 2014/
AVIATION...
/12Z TAFS/
Stratus will remain over the Heartland and Northwest Hill Country
through mid morning and then will dissipate. Going with MVFR CIGS at
the KJCT and KBBD terminals until 16Z. Mainly VFR conditions are
expected the rest of the TAF forecast. Isolated to scattered
thunderstorms will be possible east of an Abilene to
San Angelo line mainly this afternoon and tonight. Storms may even
be more numerous by tonight east of a Coleman to Junction line. The
models are developing an MCS along a cold front by 06Z Tuesday and
moving it slowly east into central Texas. However, confidence is
only high enough to add VCTS to the terminals through 02Z Tuesday.
Winds will be south and then become north as cold front moves
through West Central Texas today and this evening.
PREV DISCUSSION... /ISSUED 442 AM CDT MON MAY 12 2014/
SHORT TERM...
(Today and Tonight)
WV imagery this morning was showing and a strong upper level trough
over the central and southern Rockies with a mid level speed max of
50 to 70 knots rotating out in the Plains. Upper level flow has
backed to southwest over Texas. Also, a lot mid and upper subsidence
evident which is still resulting in a strong cap over West Central
Texas. At the surface, a cold front was located along a Quanah to
Seminole line. A dryline extended south along a Wink to Sanderson
line. Not much happening yet convection wise as low level inhibition
and cap is still holding strong. A few showers have developed just
behind the cold front across northwest Texas. The airmass was very
moist across our area with southerly flow and dewpoints in the mid
to upper 60s.
For today, the chance of showers and thunderstorms will increase mid
morning through the afternoon across mainly the eastern half of the
CWFA. The cold front will continue southeast into West Central Texas
and will probably slow its forward speed. Scattered showers and
thunderstorms will develop along and behind the front as elevated
instability erases the cap. The HRRR convective allowing model is
showing best coverage of activity east of an Abilene to San Angelo
line. The combination of good instability in the warm sector and
weak 0-6KM shear of 25 to 30 knots will result in multicell storms
with possible brief supercell structures. A few strong to severe
storms are possible across mainly the Heartland and Northwest Hill
Country. The main hazards will be large hail, damaging winds and
dangerous cloud to ground lightning. Going with mainly chance to
slight chance POPS for today. Temperatures will be cooler with highs
in the 80s.
For tonight, There will be a chance of showers thunderstorms across
much of our area with better coverage of storms east of a Coleman to
Sonora line. a few storms may be severe. The main hazards will be
large hail, damaging winds and dangerous cloud to ground lightning
mainly before 06Z Tuesday. The bigger focus will be the potential
for locally heavy rainfall across the Heartland and Northwest Hill
Country, due to good low level southerly flow. moisture flux
convergence along a slow moving cold front, PWAT values of 1.5 to
1.75 inches and in the RRQ of highly amplified 250MB jet. Rainfall
amounts of 1 to 2 inches with locally heavy amounts are possible
along and east of a Brownwood to Junction line. Also, going with
LKLY to CAT POPS across the southeast CWFA.
LONG TERM...
(Tuesday through next Monday)
The cold front will be well south of the area early Tuesday morning,
with the upper level trough axis over New Mexico. Showers and
thunderstorms may be ongoing across far southeast sections early
Tuesday morning but will move east of the area by mid to late
morning. Additional showers and isolated thunderstorms will be
possible across much of the area during the day as lift increases
ahead of the approaching upper trough. Moisture will be limited, so
precipitation is expected to be light, with most areas seeing one
tenth inch or less of rainfall. It will be considerably cooler on
Tuesday with highs well below normal for this time of year. NAM
guidance looks too cool with highs in the upper 50s, so went with a
GFS/NAM blend, which looks more reasonable with highs topping out in
the lower 60s. Lingering showers will be possible Tuesday evening
over southeast sections, otherwise dry conditions are expected
overnight with clearing skies, as drier air filters in behind the
departing upper trough. Temperatures will be very chilly Wednesday
night with overnight lows in the lower and middle 40s.
Dry and cool weather will continue on Wednesday with sunny skies,
light winds and highs in the lower 70s. Another cool night is in
store Wednesday night with low temperatures again in the 40s. Will
maintain a dry forecast Thursday into next weekend with a warming
trend through the period. Northwest flow aloft is expected through
Saturday, with a short wave ridge overspreading the Plains on
Sunday. High temperatures will warm from the mid 80s late week, to
the upper 80s and lower 90s by the end of the weekend. Expect
overnight lows in the 50s, warming into the 60s through the
period.
FIRE WEATHER...
Elevated fire weather conditions will be possible across much of
West Central Texas Wednesday through Friday, as minimum relative
humidity values drop to 15 to 20 percent, but 20 foot winds
generally remain below 15 mph.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 76 50 63 45 72 / 40 20 20 10 0
San Angelo 85 52 62 43 73 / 20 20 20 10 0
Junction 84 57 64 46 73 / 30 70 40 20 0
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
Update: Johnson
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
328 PM CDT MON MAY 12 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 328 PM CDT MON MAY 12 2014
FOCUS OF THE FORECAST IS ON THE RAIN CHANCES AND IMPACTS TONIGHT.
LATEST SURFACE ANALYSIS SUGGESTS THE INVERTED TROUGH/COLD FRONT
EXTENDS FROM NORTHWEST WISCONSIN INTO WESTERN WISCONSIN. HARD TO
DEFINE A COMPACT AREA OF LOW PRESSURE BUT LOOKS TO BE MORE OF AN
ELONGATED FEATURE ALONG THE TROUGH/FRONT FROM SOUTHEAST MINNESOTA
ACROSS MUCH OF IOWA. A WARM FRONT LOOKED TO EXTEND ACROSS
NORTHEAST IOWA INTO NORTHERN ILLINOIS...ROUGHLY ALONG THE HIGHWAY
20 CORRIDOR. LOCAL AND REGIONAL RADARS SHOWING A LINE OF
CONVECTION ALONG THE COLD FRONT FROM NORTHEAST IOWA INTO WESTERN
MISSOURI/EASTERN KANSAS.
LATEST ANALYSIS INDICATES AROUND 500 J/KG OF SB CAPE WAS ALONG
INTERSTATE 90 BUT THIS INCREASED TO ALMOST 2000 J/KG ALONG THE
SOUTHERN BORDER OF THE FORECAST AREA. THE 12.18Z RAP SUGGESTS
THESE HIGHER CAPE VALUES WILL SPREAD ACROSS THE EASTERN PARTS OF
THE FORECAST AREA THROUGH THE REST OF THE AFTERNOON INTO THE EARLY
EVENING. THE RAP BUFKIT SOUNDINGS STILL SUGGESTS THIS IS
PRIMARILY A TALL SKINNY CAPE PROFILE WHICH WOULD SUGGEST THAT
LARGE HAIL MAY NOT BE MUCH OF A THREAT. FOR ANY STORMS THAT GET
INTO THE AREA AND CAN ORIENT WITH THE 0-3KM SHEAR
VECTORS...DAMAGING WIND WILL BE POSSIBLE. CANNOT TOTALLY RULE OUT
AN ISOLATED TORNADO AS THE WARM FRONT MOVES INTO THE AREA...BUT
BECAUSE OF THE ELONGATED SURFACE LOW...NOT REALLY SEEING ANY
LOCALIZED BACKING OF THE WINDS TO ENHANCE THE LOW LEVEL HELICITY.
CURRENTLY EXPECTING THE LINE OF ACTIVITY ACROSS IOWA INTO MISSOURI
TO CONTINUE TRANSLATING NORTHEAST AHEAD OF THE TROUGH/FRONT AND
PRIMARILY AFFECTING THE EASTERN SECTIONS OF THE FORECAST AREA FROM
NORTHEAST IOWA INTO CENTRAL WISCONSIN. HAVE LINED UP THE RAIN
CHANCES WITH 80 PERCENT OVER THIS AREA TRAILING BACK TO ABOUT A 40
PERCENT CHANCE ACROSS THE WEST. AS THE TROUGH/COLD FRONT ADVANCES
SLOWLY EAST TONIGHT...THE RAIN CHANCES WILL ESSENTIALLY END FROM
WEST TO EAST AND EXPECT THE ENTIRE AREA TO BE DRY BY 12Z TUESDAY.
AFTER TONIGHT...SOME SMALL RAIN CHANCES RETURN TO THE SOUTHEAST
PARTS OF THE FORECAST AREA WEDNESDAY NIGHT. THE MEAN LONG WAVE
TROUGH WILL REMAIN OVER THE CENTRAL PART OF THE COUNTRY THANKS TO
AN UPPER LEVEL LOW NEAR HUDSON BAY AND ANOTHER SHORT WAVE TROUGH
COMING OUT OF THE SOUTHWEST PART OF THE COUNTRY. THIS SHORT WAVE
TROUGH IS EXPECTED TO PASS OFF JUST TO THE SOUTHEAST OF THE AREA
ACROSS ILLINOIS WITH THE SURFACE LOW NEAR THE OHIO RIVER. THE
DEFORMATION AREA OF RAIN ON THE NORTHWEST SIDE OF THE LOW COULD
EXTEND BACK INTO THE AREA AND WILL HAVE THE SMALL RAIN CHANCES FOR
THIS POSSIBILITY.
.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 328 PM CDT MON MAY 12 2014
THE LONG WAVE TROUGH WILL THEN MOVE SLOWLY NORTHEAST AS SEVERAL
WEAKER SHORT WAVE TROUGHS COME INTO THE LONG WAVE TROUGH ON THE
NORTHWEST FLOW FROM SOUTHERN AND WESTERN CANADA. THIS WILL PROVIDE
JUST ENOUGH FORCING FOR SOME SMALL RAIN CHANCES THURSDAY THROUGH
FRIDAY...SATURDAY AND AGAIN MONDAY. TEMPERATURES WILL STILL BE
COOL TO CLOSE OUT THE WEEK BUT THEN START TO MODERATE FOR THE
WEEKEND INTO EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1247 PM CDT MON MAY 12 2014
MUCH OF THE AREA TO GET A BREAK FROM THE SHRA/TSRA DURING THE EARLY
AFTERNOON HOURS. A SFC TROUGH/FRONT WILL SLIDE EAST INTO AND ACROSS
THE TAF SITES LATER THIS AFTERNOON/EARLY THIS EVENING. ONE MORE
ROUND OF SHRA/TSRA EXPECTED TO DEVELOP ALONG/AHEAD OF THIS BOUNDARY
AND IMPACT THE TAF SITES MAINLY IN THE 20Z-01Z PERIOD THIS
AFTERNOON/EARLY THIS EVENING. SHRA/TSRA WITH MVFR/IFR CIGS/VSBYS TO
BE MORE OF AN IMPACT AT KLSE VS. KRST...CARRIED A PERIOD OF TEMPO
TSRA AT KLSE AND ONLY VCTS/CB AT KRST DURING THIS TIME-FRAME.
ONCE THE TROUGH/FRONT PUSHES THRU...CONCERN SHIFTS TO THE ABUNDANT
LOW LEVEL MOISTURE AND IFR/LIFR CIGS BEHIND IT WHICH WILL SPREAD
ACROSS THE TAF SITES FOR MUCH OF TONIGHT INTO TUE MORNING. A PERIOD
OF MVFR VSBYS IN BR EXPECTED AS WELL. EVENTUALLY THE BRISK NORTHWEST
WINDS/LOW LEVEL FLOW WILL SPREAD/MIX SOME DRIER BOUNDARY LAYER AIR
INTO THE AREA WITH VSBYS EXPECTED TO IMPROVE TO VFR AND CIGS TO
IMPROVE TO MVFR THRU TUE MORNING.
&&
.HYDROLOGY...
ISSUED AT 328 PM CDT MON MAY 12 2014
AS THE STORMS COME IN ACROSS THE EASTERN SECTIONS TONIGHT...THE
TALL SKINNY CAPE PROFILE SHOULD LEAD TO MORE RAIN DROP PRODUCTION
INSTEAD OF HAIL. THIS CAN ALSO BE SEEN IN THE WARM CLOUD
DEPTHS...WHICH THE 12.18Z NAM CONTINUES TO SHOW TO BE AROUND 3500
METERS. WHILE THE QPF THAT FALLS THROUGH THE REST OF THE AFTERNOON
AND EVENING MAY BE AN INCH OR LESS...IT WILL BE FALLING ON GROUND
THAT RECEIVED UP TO 1.5 INCHES SUNDAY NIGHT. WITH THE GROUND BEING
SATURATED FROM THESE PREVIOUS RAINS...THE ADDITIONAL RAIN COULD
STILL PRODUCE SOME LOCALIZED FLOODING PROBLEMS AND WILL CONTINUE
THE FLASH FLOOD WATCH FOR ALL BUT THE FAR NORTHWEST SECTION OF THE
FORECAST AREA.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...FLASH FLOOD WATCH UNTIL 1 AM CDT TUESDAY FOR WIZ017-029-032>034-
041>044-053>055-061.
MN...FLASH FLOOD WATCH UNTIL 1 AM CDT TUESDAY FOR MNZ088-095-096.
IA...FLASH FLOOD WATCH UNTIL 1 AM CDT TUESDAY FOR IAZ009>011-018-019-
029-030.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION.....RRS
HYDROLOGY...04
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
310 PM CDT MON MAY 12 2014
.REST OF THIS AFTERNOON AND TONIGHT - CONFIDENCE...MEDIUM
ELONGATED LOW PRESSURE FROM ERN IA INTO WRN WI AREA WILL LIFT TO
NORTH OF LAKE SUPERIOR. PLENTY OF MOIST AND UNSTABLE AIR RETURNING.
SPC MESO CHARTS ARE SHOWING SOME VERY IMPRESSIVE PARAMETERS
ESPECIALLY INTO SC WI. SO HEIGHTENED CONCERN FOR ALL FORMS OF SEVERE
WEATHER AND THIS INCLUDES THE POTENTIAL FOR TORNADOGENESIS. OUTFLOW
BOUNDARY SETTING UP FAR SRN WI WILL ONLY ADD TO THAT CONCERN.
ISOLATED STORMS ALREADY FIRING ACRS NRN IL. 0-6KM SHEAR AND 0-1KM
SHEAR GETS A LITTLE BETTER MOVING FROM IL INTO WI. LATEST HRRR
SHOWING IA DEVELOPMENT SPREADS ACRS SRN WI LATE AFTN/ERLY EVE WITH
LESS CONFIDENCE LATER IN THE NIGHT WITH THE APPROACH OF THE COLD
FRONT. AIRMASS MAY BE PRETTY WORKED OVER BY THEN. TWO AREAS RECEIVED
DECENT RAINS...ONE BEING IN THE NW CWA NEAR THE DELLS AND THE OTHER
IN THE SE. WILL HOLD OFF ON FLASH FLOOD WATCH AS CONVECTION SHOULD
BE ON THE MOVE BUT ANY TRAINING ALONG THE OUTFLOW COULD CAUSE
PROBLEMS.
.TUESDAY - CONFIDENCE...MEDIUM
LOW PRESSURE WILL CONTINUE TO LIFT NNE INTO CANADA WITH COLD FRONT
SHIFTING TO THE EAST. EXPECT SOME LINGERING SHRA IN ERN CWA DURG THE
MRNG HRS. UPPER FLOW IS STILL SOUTHWEST SO THIS WILL LIKELY CARRY
SOME WEAK DISTURBANCES ALONG AND AHEAD OF 850 FRONT TO MAINTAIN RAIN
CHANCES IN THE MORNING ACROSS THE SE 1/2. THEN WITH THE COLD
ADVECTION ON THE BACK SIDE OF THIS SYSTEM WE CAN TAKE ABOUT 10-15
DEGREES OFF THE 925 TEMPS. SO TURNING COOLER...LESS HUMID AND LIKELY
A GOOD DEAL OF CLOUD COVER TO CONTEND WITH. LLVL RH PROGS AND MOS
SKY COVER SUGGEST THIS... ESPECIALLY WITH THE INCOMING LOW LEVEL
COOL POOL AND MID LEVEL TROUGH AXIS STILL TO THE WEST.
.TUESDAY NIGHT - CONFIDENCE...HIGH
A QUIET PERIOD AS DRY...COOLER AIR SETTLES INTO SOUTHERN WI. 85H
TEMPS FALL TO AROUND 0C OVERNIGHT. BOUNDARY LAYER MIXING WILL KEEP
THE LOWEST LEVELS STIRRED ENOUGH TO KEEP OVERNIGHT TEMPS MOSTLY 40
TO 45F.
.WEDNESDAY THROUGH THURSDAY...FORECAST CONFIDENCE - MEDIUM.
UNCERTAINTY CREEPS IN LATER WEDNESDAY THROUGH THURSDAY FOR PRECIP
THREAT. SHORT TERM GUIDANCE IN GENERAL AGREEMENT ON CYCLOGENESIS
OCCURRING OVER SOUTHERN PLAINS LATER WEDNESDAY WITH STRENGTHENING
LOW PRESSURE TRACKING NORTHEAST THROUGH THE TN AND OH VALLEYS. MID-
LEVEL CIRCULATION TRACKING ALONG BAROCLINIC ZONE OVER IL MAY BRING
SOME -RA TO SOUTHEAST WI WED NGT INTO THU. HOWEVER LATEST CANADIAN
A LITTLE FARTHER EAST WITH THE BAROCLINIC ZONE. DUE TO
UNCERTAINTY...WL BUMP UP POPS TO HIGH CHANCE IN MY
SOUTHEAST...DROPPING OFF FAIRLY QUICKLY TO LOW/SLIGHT CHANCE AS
EXPECT A SHARP CUTOFF ACROSS SOUTHEAST WI. LOW LEVEL THERMAL
PROFILE FAVORS RAIN...HOWEVER IF SLIGHT ADDITIONAL COOLING WERE TO
TAKE PLACE...THEN COULD BE SOME SNOW MIXED IN WITH THE RAIN AT
TIMES.
.THURSDAY NIGHT THROUGH MONDAY...FORECAST CONFIDENCE - MEDIUM.
LOW MOVING NORTH FROM THE OH VALLEY ACROSS THE GTLAKES THU AND THU
NIGHT WILL TRANSITION TO STATIONARY UPPER LOW OVER THE REGION FOR
THE END OF THE WEEK...ON INTO THE WEEKEND. THIS WILL RESULT IN
CONTINUED PERIOD OF COLD NORTHWEST WINDS REINFORCING CHILLY AIR OVER
SRN WI INTO SATURDAY. THE UPPER LOW FINALLY STARTS TO BREAK DOWN
OVER THE WEEKEND...WHICH WOULD ALLOW MILDER AIR TO RETURN TO THE
AREA BEGINNING SUNDAY. OVERNIGHT LOWS EXPECTED TO DIP INTO THE 30S
SEVERAL NIGHTS. WL NEED TO WATCH NIGHT TIME CLOUD COVER AND THINK
ABOUT FROST POTENTIAL FOR THURSDAY NIGHT AND FRIDAY NIGHT.
&&
.AVIATION/00Z TAFS/...MAIN SHORT TERM CONCERN WILL BE CONVECTION
INTO THE EVENING HOURS. NEXT WAVE OF STORMS APPROACHING FROM IOWA
WILL ARRIVE LATER THIS AFTN/EVE. ISOLATED STORMS FIRING VCNTY
OUTFLOW BOUNDARY IN NRN IL. THESE MAY BECOME SVR. STORMS IN IA MOVG
INTO WI THIS EVE MAY BE SVR AS WELL. LATEST HRRR SUGGESTS LESS
ACTIVITY LATER IN THE NIGHT AS AIRMASS STABILIZES ONCE THIS SURGE
PASSES. HOWEVER WILL STILL KEEP TSRA CHANCES DUE TO APPROACHING
UPPER JET DYNAMICS AND SURFACE COLD FRONT DRAWING CLOSER. DENSE FOG
CONCERNS ARE NORTH OF TAF SITES.
&&
.MARINE...WILL RETAIN DENSE FOG ADVISORY THROUGH LATER IN THE NIGHT
FOR PORT WASHINGTON TO SHEBOYGAN AS THAT AREA ENTRENCHED IN THE
FOGGY CONDITIONS WITH COOL FLOW OFF THE LAKE.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...DENSE FOG ADVY LMZ643 TIL 03Z/13.
&&
$$
TONIGHT/TUESDAY AND AVIATION/MARINE...PC
TUESDAY NIGHT THROUGH MONDAY...MBK
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1119 AM CDT MON MAY 12 2014
.UPDATE...LOTS GOING ON FROM DENSE FOG IN PARTS OF EC WI AND OVER
THE LAKE...TO LINE OF STORMS RACING EAST THROUGH SRN WI. SPC MESO
PAGE SHOWS DECENT AIRMASS IN PLACE FOR THE STORMS IN NRN IL TO
FEED OFF. LOTS OF CLOUDS UPSTREAM SO FURTHER DESTABILIZATION LATER
WILL HINGE ON GETTING THINGS CLEARED OFF. BUT BETTER DYNAMICS AND
COLD FRONT ARRIVES TONIGHT. LATEST HRRR DOES SHOW MORE CONVECTION
ARRIVING TONIGHT WITH SLIGHT RISK STILL IN PLACE.
PC
&&
.AVIATION/18Z TAFS/...MAIN SHORT TERM CONCERN WILL BE ONGOING LINE
OF STORMS SWEEPING THROUGH SRN WI. DENSE FOG CONCERNS ARE NORTH
OF TAF SITES. WILL CLEAR CURRENT STORMS OUT OF THE FAR EAST BY 20Z
OR SO THEN WAIT FOR POSSIBLE REDEVELOPMENT THIS EVENING AND
OVERNIGHT AS COLD FRONT AND BETTER DYNAMICS GET A BIT CLOSER.
PC
&&
.PREV DISCUSSION... /ISSUED 340 AM CDT MON MAY 12 2014/
TODAY AND TONIGHT...FORECAST CONFIDENCE...HIGH
THE UPPER LEVEL RIDGE OVER THE WESTERN GREAT LAKES AHEAD OF THE
STRONG WESTERN TROUGH ACROSS THE ROCKIES WILL PUSH INTO THE EASTERN
GREAT LAKES BY SUNRISE TUESDAY. THE 105 KNOT JET MAX WAS LIFTING
NORTHEAST FROM THE BASE OF THE TROUGH THIS MORNING AND WILL REACH
WESTERN MINNESOTA THIS EVENING STRENGTHENING TO 115 KNOTS. WEAK TO
MODERATE UPPER DIVERGENCE CONTINUES ACROSS SOUTHERN WISCONSIN TODAY
AND TONIGHT.
A 700 MB WIND MAX OF 40 KNOTS PUSHES INTO CENTRAL WISCONSIN BY
SUNRISE. A SECOND STRONGER 700 MB WIND MAX OF 55 KNOTS ASSOCIATED
WITH THE MAIN TROUGH REACHES WESTERN WISCONSIN THIS EVENING AND
PUSHES EAST EARLY TUESDAY MORNING. AT 850 MB A 50 KNOT LOW LEVEL JET
ACROSS EASTERN KANSAS INTO SOUTHERN IOWA PUSHES INTO SOUTHWEST
WISCONSIN JUST AFTER SUNRISE BEFORE WEAKENING AND LIFTING NORTH
LATER THIS MORNING. A 45 KNOT 850 MB JET MAX ALSO MOVES ACROSS
SOUTHERN WISCONSIN LATE TONIGHT.
700 MB MODERATE UPWARD MOTION OCCURS EARLY THIS MORNING WITH THE
APPROACHING LOW LEVEL JET MAX AND 850 MB MOISTURE CONVERGENCE AS THE
WARM FRONT ADVANCES NORTH. THEREFORE EXPECT AN AREA OF THUNDERSTORMS
TO ROLL THROUGH THIS MORNING. SOME MAY PRODUCE BRIEF HEAVY RAINS.
850/700 MB DEW POINTS INCREASE THIS MORNING WITH 850 MB DEWPOINTS
AROUND 11 TO 12 CELSIUS THIS EVENING UNTIL THE CONVECTION OCCURS.
BY AFTERNOON SOUTH CENTRAL AND SOUTHEAST WISCONSIN WILL BE IN THE
WARM SECTOR. UNTIL THEN EAST TO SOUTHEAST WINDS WILL KEEP THE
LAKESHORE AREAS COOL WITH SOME FOG POSSIBLE AS THE AIRMASS DEW
POINTS RISE INTO IN THE MID 60S...WITH SOME UPPER 60S POSSIBLE.
INLAND AREAS SHOULD REACH 80...BUT AREAS ALONG THE LAKE...ESPECIALLY
TOWARD SHEBOYGAN SHOULD STAY COOLER WITH SOUTH/SOUTHEAST FLOW MUCH
OF THE DAY.
WITH MODELS PRODUCING SOME PRECIPITATION TODAY IN THE WARM
SECTOR...THE AMOUNT OF MODEL CAPE IS LIKELY LESS THAN WHAT WILL
OCCUR. THERE WILL BE A CHANCE OF THUNDERSTORMS...BUT LIFTING
MECHANISM DIFFICULT FOR TIMING DUE TO LIKELY MORNING CONVECTION AND
BOUNDARIES.
FOCUS FOR SEVERE WILL LIKELY BE IN AREAS WEST OF MADISON EARLY THIS
EVENING AHEAD OF THE ADVANCING COLD FRONT. HELICITY VALUES DO RISE
TO NEAR 200 WITH SOME LOW LEVEL VEERING. THEREFORE THERE WILL BE A
TORNADO THREAT. COLD FRONT THEN MOVES ACROSS SOUTHERN WISCONSIN
TONIGHT WITH A LINE OF THUNDERSTORMS EXPECTED. CAPE VALUES WILL
DECREASE AS THE STORMS MOVE EAST DUE TO DIURNAL COOLING.
LOCAL SEVERE PROBABILITY CWASP VALUES INCREASE TO 75 TO 80 PCT INTO
PORTIONS OF SOUTH CENTRAL WISCONSIN THIS AFTERNOON AND EARLY EVENING
WITH 70 PCT EAST.
TUESDAY AND WEDNESDAY...FORECAST CONFIDENCE...MEDIUM
THE SURFACE COLD FRONT SHOULD BE THROUGH BY DAYBREAK
TUESDAY...WITH A FEW SHOWERS/STORMS POSSIBLY LINGERING EAST IN THE
MORNING. IT SHOULD BE DRY THEN THE REST OF THE DAY WITH MUCH
COOLER TEMPS BEHIND THE DEPARTING FRONT.
DRY WEATHER WILL THEN PERSIST TUESDAY NIGHT THROUGH AT LEAST
WEDNESDAY MORNING. LOW PRESSURE PASSING BY WELL TO THE SOUTHEAST
MAY BRING SOME LIGHT RAIN THEN LATE WEDNESDAY AFTERNOON INTO THE
NIGHT...MAINLY ACROSS THE SOUTHEAST. EVEN COOLER TEMPS ARE LIKELY
WEDNESDAY...STRUGGLING INTO THE UPPER 50S MOST PLACES.
THURSDAY THROUGH SUNDAY...FORECAST CONFIDENCE...MEDIUM
NORTHWEST FLOW WILL BRING CONTINUED BELOW NORMAL TEMPERATURES FOR
THURSDAY THROUGH THE WEEKEND. A SERIES OF SHORTWAVES WILL ALSO
BRING A CHANCE FOR SHOWERS AT TIMES.
AVIATION/12Z TAFS/...
STILL EXPECTING SOME MVFR CIGS/VSBYS AHEAD OF A WARM FRONT. THE
WARM FRONT WILL LIFT NORTH THIS MORNING...BUT SOME SOUTHEAST FLOW
MAY STILL AFFECT THE LAKESHORE AREAS OF LAKE MICHIGAN WITH MVFR
VSBYS IN FOG/HAZE.
EXPECT AN AREA OF THUNDERSTORMS THIS MORNING WITH THE WARM FRONT AND
A CHANCE OF THUNDERSTORMS THIS AFTERNOON. THEN MORE THUNDERSTORMS
LIKELY WITH A COLD FRONT TONIGHT. SOME OF THE STORMS COULD BE
SEVERE...ESPECIALLY THIS AFTERNOON AND EVENING. IFR CONDITIONS IN
ANY STORMS.
MARINE...
LIGHT EAST TO SOUTHEAST WINDS THIS MORNING AHEAD OF AN ADVANCING
WARM FRONT WILL BRING AREAS OF FOG. THE WARM FRONT WILL MOVE NORTH
LATER TODAY BUT A WEAK ONSHORE FLOW WILL LIKELY CONTINUE NORTH OF
MILWAUKEE. LOOK FOR PERIODS OF THUNDERSTORMS TODAY AND TONIGHT.
SOME MAY BE SEVERE ESPECIALLY TONIGHT.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...DENSE FOG ADVISORY UNTIL 1 PM CDT THIS AFTERNOON FOR WIZ052.
LM...DENSE FOG ADVISORY UNTIL 2 PM CDT THIS AFTERNOON FOR LMZ643.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...HENTZ
TUESDAY THROUGH SUNDAY...DDV