Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 06/17/13
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
813 PM MDT SUN JUN 16 2013
.UPDATE...
&&
.SHORT TERM...MOST ACTIVITY HAS ENDED ALTHOUGH THERE ARE A FEW
LINGERING SHOWERS AND STORMS IN THE MTNS. AN OUTFLOW BNDRY FROM
CONVECTION OVER NE AND KS WAS MOVING INTO FAR NERN CO EARLY THIS
EVENING. LATEST RAP HAS A WK DENVER CYCLONE DEVELOPING OVERNIGHT
WITH THE BNDRY STALLING OVER SRN WELD AND MORGAN COUNTIES. STRATUS
WILL LIKELY DVLP LATER TONIGHT OVER THE PLAINS ALONG AND NORTH OF
BNDRY.
.AVIATION...WINDS HAVE BEEN SWLY EARLY THIS EVENING. LATEST RAP
DVLPS A WK DENVER CYCLONE OVERNIGHT OVER SRN WELD COUNTY AND KEEPS
WINDS SSW THRU 12Z AS OUTFLOW BNDRY MENTIONED ABV STALLS OUT TO
THE N AND NE OF THE AIRPORT. FOR NOW WILL NOT MENTION ANY STRATUS
BUT IF BNDRY ENDS UP FURTHER SW THEN SOME OF THE STRATUS COULD
POSSIBLY AFFECT DIA AFTER 12Z.
&&
.PREV DISCUSSION... /ISSUED 331 PM MDT SUN JUN 16 2013/
SHORT TERM...MAIN AREA OF STRONGER CONVECTION AND POTENTIAL
SEVERE WEATHER IS QUICKLY SHIFTING EASTWARD ACROSS THE EASTERN
PLAINS THIS AFTERNOON. THERE WAS SOME BRIEF CLEARING BEHIND
THIS...WHILE NEXT BATCH OF STORMS WAS SPREADING EAST ACROSS
NORTHWEST COLORADO. STABILIZATION HAS OCCURRED BEHIND THE INITIAL
BATCH...BUT STILL CAN`T RULE OUT A FEW STORMS LINGERING THROUGH
THE EVENING AND PUSHING EAST ACROSS THE FRONT RANGE. BELIEVE THE
GOING FORECAST OF SLIGHT CHANCE BEHIND THE INITIAL CONVECTION
WORKS WELL AT THIS TIME. STORMS WILL DIE OFF BY OR SHORTLY AFTER
SUNSET WITH THE LOSS OF DAYTIME HEATING.
ON MONDAY...THE AIRMASS WILL LIKELY BECOME INCREASINGLY MOIST AND
UNSTABLE OVER THE NORTHEAST PLAINS AS DEEPER LOW LEVEL MOISTURE
PUSHES SLOWLY SOUTHWEST BEHIND A FRONTAL/BOUNDARY SURGE. THIS
WOULD BRING CAPES TO NEAR 2000 J/KG RANGE...SO SEVERE STORMS WILL
BE POSSIBLE ONCE AGAIN. AT THIS TIME...MAIN THREAT LOOKS TO BE
OVER THE NORTHEAST CORNER OF THE STATE WHILE LOCATIONS ALONG THE
FRONT RANGE WOULD MOST LIKELY SEE DRIER AIR REMAIN IN PLACE. ONE
FACTOR THAT COULD BRING STRONGER STORMS INTO THE FRONT RANGE METRO
AREA WOULD BE A BIGGER SURGE FROM CONVECTION OVER NEBRASKA
TONIGHT/EARLY MONDAY MORNING SO WILL CONTINUE TO MONITOR THAT.
LONG TERM...THE RIDGE ALOFT WILL REMAIN OVER THE ROCKY MOUNTAIN
REGION THROUGH WEDNESDAY BEFORE SHIFTING EAST INTO THE CENTRAL
PLAINS ON THURSDAY AND FRIDAY. FOR MONDAY NIGHT AND TUESDAY EXPECT
SCATTERED THUNDERSTORMS OVER THE PLAINS...MORE NUMEROUS ON THE
FAR NORTHEAST PLAINS WITH A SLIGHT CHANCE FOR SEVERE STORMS.
MOISTURE LEVELS WILL BE HIGHER ON THE EASTERN PLAINS WITH
SUFFICIENT SHEAR FOR SEVERE STORMS. FURTHER WEST NEAR THE
MOUNTAINS...THE AIRMASS WILL BE DRIER WITH MAINLY GUSTY WINDS AND
BRIEF RAIN WITH THE STORMS.
AS THE RIDGE SHIFTS EAST LATER IN THE WEAK...THE FLOW ALOFT WILL
BE A MORE DRIER AND WARMER SOUTHWEST FLOW. THIS WILL BRING DRY
CONDITIONS EXCEPT FOR FAR EASTER COLORADO WILL THERE MAY BE AN
ISOLATED STORM WITH BETTER MOISTURE THERE. THIS PATTERN LATE IN
THE WEEK WILL ALSO RESULT IN ELEVATED FIRE DANGER OVER COLORADO
WITH THE WARMER AND DRIER CONDITIONS. TEMPERATURES ACROSS LOWER
ELEVATIONS WIL RETURN INTO THE 90S.
AVIATION...MAIN THREAT OF STORMS HAS SHIFTED EAST OF THE AIRPORTS
AS OF MID AFTERNOON...BUT GUSTY WINDS REMAINED. THE WINDS WILL
LIKELY FAVOR WESTERLY DIRECTIONS BUT MAY BECOME VARIABLE DUE TO
STRONG OUTFLOW OF ANY SHOWERS/STORMS THROUGH THE COURSE OF THE
EVENING. STRATUS THREAT LATE TONIGHT AND EARLY MONDAY MORNING IS
LOW AT THIS POINT WITH BETTER MOISTURE CONFINED TO THE FAR
NORTHEAST PLAINS. STORM COVERAGE MONDAY ALSO LOOKS ISOLATED BUT
PERHAPS A BETTER CHANCE AFTER 00Z TUESDAY WITH ANY
OUTFLOWS/MOISTURE SURGES BACKING AGAINST THE FRONT RANGE.
HYDROLOGY...NO CONCERNS AT THIS TIME DUE TO FAST MOVING AND
GENERALLY LIGHT PRECIPITATION IN THE MOUNTAINS/FOOTHILLS LATE THIS
AFTERNOON/EVENING.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RPK
LONG TERM....ENTREKIN
AVIATION...RPK
AREA FORECAST DISCUSSION
NWS ALBANY NY
1043 PM EDT SUN JUN 16 2013
.SYNOPSIS...
A WIND SHIFT LINE WILL WORK ACROSS THE REGION TONIGHT WITH FEW IF
ANY ADDITIONAL SHOWERS. A STRONGER COLD FRONT WILL SLOWLY APPROACH
DURING THE FIRST COUPLE OF DAYS OF THIS WORK WEEK. THIS WILL KEEP
OUR PATTERN A LITTLE UNSETTLED WITH THE CHANCE FOR SHOWERS AND
THUNDERSTORMS. OUR WEATHER IMPROVES FOR THE MID AND LATE WEEK PERIOD
AS HIGH PRESSURE SETTLES IN WITH DRIER AND SEASONABLE CONDITIONS.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF 1030 PM EDT...WE ARE TRACKING A FEW CELLS WELL TO OUR
NORTHWEST THAT HAVE WORKED OFF LAKE ONTARIO (AND BUFFALO ISSUED
SPECIAL MARINE WARNING FOR)...HAVE WEAKENED BUT NOT ENTIRELY AS THEY
APPROACH HERKIMER COUNTY. THE HRRR INDICATES THESE CELLS COULD HOLD
TOGETHER DOWN INTO THE MOHAWK VALLEY...BUT AS WEAK ONES.
WE WILL CONTINUE TO MONITOR.
THE CLOUDS DID IN FACT DIMINISH AROUND THE REGION AND AS A
RESULT...SOME PATCHY FOG WAS ALREADY BEGINNING TO FORM IN THE USUAL
FOG PRONE PLACES.
FOR NOW...CONTINUE SLIGHT CHANCES OF SHOWERS THROUGH 100 AM.
OTHERWISE VERY FEW CHANGES TO THE EXISTING FORECAST. LOOK FOR LOWS
AROUND 60 LOCALLY IN THE CAPITAL DISTRICT...MID TO UPPER 50S ACROSS
THE REMAINDER OF THE REGION.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
GENERALLY FOLLOWED THE GFS/ECMWF FOR THE SHORT TERM PORTION OF THE
FORECAST.
A CLOSER LOOK AT THE H2O VAPOR LOOP REVEALS A NEARLY ZONAL FLOW
ACROSS THE NORTHERN TIER OF THE CONUS. A FEW UPSTREAM WAVES...ONE
APPROACHING THE ARROWHEAD OF MINNESOTA...ONE JUST SOUTH OF LAKE
WINNIPEG AND THE OTHER IN THE VICINITY OF SOUTHERN HUDSON BAY...
WILL ACT IN TANDEM TO BRING UNSETTLED CONDITIONS THROUGH TUESDAY.
THE NAM WANTS TO BREAK THE PATTERN RATHER QUICKLY AS THE GLOBAL
MODELS AND ITS ENSEMBLES FAVOR A SLOWER PROGRESSION AND WAS
FOLLOWED FOR THIS FORECAST.
MONDAY...A PRE-FRONTAL TROUGH AXIS WITHIN A WARM SECTOR MAY
DEVELOP SOME CONVECTION BUT SEVERE POTENTIAL LOOKS RATHER LIMITED.
COMBINATION OF SBCAPES LESS THAN 1K J/KG AND SHEAR VALUES OF
20-30KTS SUGGEST SUB-SEVERE CONDITIONS. HOWEVER...BEST LOW LEVEL
CONVERGENCE FIELDS ARE NORTH OF I90 AND THIS IS WHERE WE WILL
PLACE THE HIGHER POPS. SINCE WE SHOULD SEE SOME BREAKS OF
SUNSHINE...WE WILL CONTINUE TO FAVOR THE COOLER SIDE OF THE MOS
GUIDANCE.
MONDAY NIGHT...THOSE AFOREMENTIONED UPSTREAM WAVES CONTINUE TO
APPROACH WITH DOWNSTREAM IMPACTS /IE OUR REGION/ KEEPS THE UPPER
FLOW RATHER ZONAL. THIS WILL LIKELY SLOWLY DOWN THE SURFACE FRONT
FURTHER /NON-NAM SOLUTION/ TO KEEP OUR PATTERN RATHER UNSETTLED
WITH CONSIDERABLE CLOUD COVER AND STILL THE CHANCE FOR SHOWERS.
THERE COULD BE MORE PROBLEMATIC ISSUES WITH FOG BUT THE BOUNDARY
LAYER WINDS MAY BE JUST ENOUGH TO LIMIT WIDESPREAD FOG SO WE WILL
WATCH TRENDS. GUIDANCE NUMBERS THIS TIME FRAME ARE FAIRLY CLOSE
AND A BLENDED APPROACH WAS UTILIZED WITH MAINLY 50S FOR OVERNIGHT
LOWS.
TUESDAY...THE COMBINATION OF THE UPSTREAM WAVES AND SURFACE COLD
WILL PROVIDE THE REGION WITH THE BEST CHANCE FOR DEEPER
CONVECTION. THE DEGREE OF INSTABILITY WILL BE HIGHLY DEPENDENT ON
THE AMOUNT OF INSOLATION WE RECEIVE WHICH APPEARS LIMITED AT THIS
TIME. IF THERE IS A WINDOW OF OPPORTUNITY...SOUTH OF I90 WOULD BE
THE HIGHER PROBABILITY FOR STRONGER STORMS. IN COLLABORATION WITH
SPC...WE WILL KEEP THREAT OF SEVERE POPS AT OR BELOW 5%. HIGH
TEMPERATURES SHOULD AVERAGE INTO THE 70S.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
DRY WEATHER SHOULD BE THE RULE THROUGH MUCH OF THE PERIOD.
HOWEVER...THERE IS A POTENTIAL FLY IN THE OINTMENT.
THE 12Z GFS INDICATED LARGE CANADIAN HIGH PRESSURE WILL BUILD INTO
OUR REGION WEDNESDAY...BRINGING INITIALLY COOLER THAN NORMAL WEATHER
BUT DRY WEATHER THROUGH THE SATURDAY. AS THE HIGH SLIDES OFF THE
COAST...TEMPERATURES WOULD SLOWLY MODERATE.
WHILE THE 12Z EUROPEAN (ECMWF) AND CANADIAN (CMC) LONG RANGE MODELS
KEEP US DRY...BOTH INDICATED AN AREA OF LOW PRESSURE DEVELOPING
ALONG THE DEPARTING COLD FRONT...SLIDING TO OUR SOUTH BRINGING
ANOTHER ROUND OF RAIN TO THE MID ATLANTIC STATES. THE CMC BROUGHT
RAIN RIGHT TO ABOUT THE I-84 AREA EARLY WEDNESDAY BEFORE HIGH
PRESSURE SQUELCHED IT FURTHER SOUTH.
IF THE MID LEVEL TROUGH WERE TO BECOME SHARPEN AND MORE
DEFINED...THERE WOULD BE AN OUTSIDE CHANCE LOW PRESSURE COULD REACH
FAR ENOUGH NORTH TO BRING SOME RAIN WEDNESDAY INTO MUCH OF OUR
REGION BUT AT THIS TIME WE LEAN AGAINST THIS SOLUTION.
HOWEVER...THIS STILL SEVERAL DAYS AND THERE IS A CHANCE THE
CONFIGURATION COULD CHANGE A LITTLE BY THEN.
BY NEXT SUNDAY...ALL MODELS HAVE THE HIGH PRESSURE AREA WELL OFF
SHORE AND A WARM FRONT COULD BRING SOME SHOWERS BACK TO THE
REGION...MAYBE EVEN THUNDERSTORMS.
TEMPERATURES THROUGHOUT THE PERIOD LOOK TO AVERAGE A LITTLE BELOW
NORMAL. PRECIPITATION MIGHT ACTUALLY ENDING UP BEING A LITTLE BELOW
NORMAL AS WELL.
LOOK FOR HIGHS ON WEDNESDAY RANGING FROM THE UPPER 60S TO MID 70S
WHILE OVERNIGHT LOWS WEDNESDAY NIGHT COULD ACTUALLY DIP INTO THE 40S
REGIONWIDE. HIGHS WILL MODERATE TO THE 70S TO NEAR 80 BY FRIDAY
THROUGH SUNDAY WITH OVERNIGHT LOWS AROUND 50 NORTH TO LOWER 60S
SOUTH.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
LOW PRESSURE AND WEAK SURFACE TROUGH WILL WORK THROUGH THE TAFS THIS
EVENING WITH LITTLE FANFARE. HOWEVER...THERE MIGHT BE SOME IFR FOG
OVERNIGHT...MAINLY AT KGFL.
WITH THE EXCEPTION OF THE KGFL LITTLE OR NO RAIN HAS FALLEN AT THE
OTHER TAF SITES. THE LACK OF RAIN (TODAY) AND A LITTLE BREEZE BEHIND
THE TROUGH MIGHT PREVENT IFR FOG AT KALB/KPOU/KPSF OVERNIGHT. FOR
NOW...WE DID PLACE MVFR FOG IN WITH NO RESTRICTING CIGS OVERNIGHT
UNTIL THE MORNING PEAK. CONFIDENCE OF THIS WAS MODERATE BUT NOT HIGH
(ABOUT 70 PERCENT).
ON THE OTHER HAND...SOME RAIN DID FALL AT KGFL. ASSUMING NOT MUCH OF
BREEZE THIS EVENING...AND EVEN LESS OVERNIGHT...WE DECIDED TO TO
PLACE IFR FOG IN THAT TAF...BEGINNING AS TEMPO GROUP AT 04Z...THEN
PREVAILING FROM 06Z ON. AGAIN CONFIDENCE OF THIS IS MODERATE (NOT
HIGH)...ABOUT 60-70 PERCENT.
ANY FOG SHOULD DISSIPATE BY 12Z MONDAY AS BREEZE FROM THE WEST OR
SOUTHWEST PICKS UP TO 5-10KTS. LOOKING AT MAINLY VFR CONDITIONS BUT
THERE IS A CHANCE OF SHOWERS AND EVEN A THUNDERSTORM LATER IN THE
AFTERNOON (AFTER 21Z). FOR NOW...JUST WENT WITH THE VCSH SINCE
CONFIDENCE IS LOW (LESS THAN 25 PERCENT) THAT ANY TAF SITES WOULD
SEE IFR OR EVEN MVFR WITH ANY SHOWER/THUNDER.
OUTLOOK...
MON NITE...MAINLY VFR. CHC EVE -SHRA/-TSRA.
TUE...MAINLY VFR. SLIGHT CHC -TSRA.
TUE NIGHT-FRI...VFR. NO SIG WX.
&&
.FIRE WEATHER...
NO FIRE WEATHER RELATED PROBLEMS ARE EXPECTED THE NEXT SEVERAL
DAYS DUE TO THE PERSISTENT WET PATTERN SINCE LATE MAY.
THE CHANCE FOR ADDITIONAL SHOWERS AND THUNDERSTORMS WILL PERSIST
THROUGH TUESDAY UNTIL A COLD FRONT THAT IS FORECAST TO SLIDE SOUTH
OF THE REGION TUESDAY NIGHT.
DRIER WEATHER IS EXPECTED FOR THE SECOND HALF OF THE WEEK WITH
HIGHER SURFACE PRESSURE SETTLING INTO THE REGION.
&&
.HYDROLOGY...
FLOWS REMAIN ABOVE NORMAL FOR MID JUNE ACROSS THE HYDRO SERVICE
AREA. MINOR FLOODING CONTINUES ACROSS PORTIONS OF THE HOUSATONIC
BASIN IN NW CT FROM THE HEAVY RAINFALL A FEW DAYS AGO.
RAINFALL TODAY INTO TONIGHT WILL RANGE FROM A QUARTER OF AN INCH
OR LESS WITH EVEN LOWER VALUES SOUTH OF I90.
QPF WILL BE HIGHLY VARIABLE WITH THE COLD FRONTAL PASSAGE MONDAY
INTO TUESDAY WITH A FEW HUNDREDTHS TO A FEW TENTHS OF AN INCH
POSSIBLE WITH LOCALLY HIGHER AMOUNTS WITH ANY THUNDERSTORMS.
DRY WEATHER IS EXPECTED TO RETURN TUESDAY NIGHT INTO THE MID WEEK
ALLOWING RIVERS TO CONTINUE TO GRADUALLY LOWER FROM THE VERY WET
WEATHER THE PAST FEW WEEKS.
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...HWJIV/BGM
NEAR TERM...HWJIV
SHORT TERM...BGM
LONG TERM...HWJIV
AVIATION...HWJIV
FIRE WEATHER...BGM/WASULA
HYDROLOGY...BGM
AREA FORECAST DISCUSSION
NWS MIAMI FL
202 PM EDT SAT JUN 15 2013
.DISCUSSION...
HIGH PRESSURE BUILDING OVER THE AREA, HAS ALLOWED THE UPPER
ATMOSPHERE TO WARM AND DRY OUT SOME. THIS HAS INHIBITED ANY
CONVECTIVE CELLS SO FAR TODAY. THE GFS KEEPS ANYTHING THAT IS ABLE
TO DEVELOP, NEAR THE LAKE REGION. THE ECMWF IS NOT MUCH DIFFERENT.
WITH LAPSE RATES LOWER THAN YESTERDAY, AS WELL AS PWATS DROPPING TO
BELOW 1.5 INCHES, THIS IS BELIEVABLE. THE HRRR IS SHOWING
CONVECTION TRYING TO FIRE IN THE WESTERN HALF OF THE CWA THIS
EVENING, BUT AM NOT BITING OFF ENTIRELY ON THIS SCENARIO. HAVE
KEPT LOW END CHANCE POPS OVER GLADE/HENDRY/AND COLLIER COUNTIES,
AND SLIGHT CHANCE OVER MUCH OF THE REST OF THE CWA, BUT THIS MAY
WELL EVEN BE OVERKILL TODAY. BUT, ONLY TIME WILL TELL. IF IT IS
NOT ABLE TO GO TODAY, IT WILL PROBABLY HAVE A HARD TIME GOING
TOMORROW AS WELL, AS CONDITIONS WILL ONLY BE DRIER, WITH A
SOMEWHAT STRONGER UPPER LEVEL HIGH. HAVE KEPT LOW END CHANCE OVER
THE GULF COAST FOR TOMORROW WITH THIS PACKAGE, BUT AGAIN, THAT MAY
BE TOO HIGH.
THE HIGH CONTINUES FOR THE BEGINNING OF THE WEEK IN THE UPPER
LEVELS. IN THE LOWER LEVELS, HOWEVER, THE BERMUDA HIGH STRENGTHENS
ONCE AGAIN, BRINGING A MORE EASTERLY FLOW BACK TO SOUTH FLORIDA,
AND THEREFORE INCREASING MOISTURE. SO, THE GULF COAST WILL KEEP
CHANCE POPS INTO AT LEAST MID NEXT WEEK AND PROBABLY THROUGH THE
END OF THE WEEK, BY WHICH TIME, MORE OF SOUTH FLORIDA MAY SEE
CONVECTION FIRING.
THERE IS A TROPICAL WAVE THAT MODELS SHOW WILL BE WELL TO THE
SOUTH. IF IT KEEPS THAT TRACK, IT SHOULD NOT HAVE AN IMPACT ON
SOUTH FLORIDA WEATHER. IF IT DOES COME CLOSER, IT WILL, OF COURSE,
CHANGE THE FORECAST TO MOST LIKELY ADDITIONAL COVERAGE OF SHOWERS
AND THUNDERSTORMS FROM MID TO LATE NEXT WEEK.
&&
.AVIATION...
THE EAST AND WEST COAST SEA BREEZES WILL CONTINUE TO PUSH INLAND
THIS AFTERNOON...AND THE EAST COAST SEA BREEZE SHOULD BE WEST OF
THE EAST COAST TAF SITES BY 20Z. SO WILL KEEP THE VRB05 KTS IN THE
EAST COAST TAF SITES UNTIL 19Z BEFORE GOING TO A EASTERLY
DIRECTION AT 5 TO 10 KNOTS UNTIL 01Z. THE WINDS WILL THEN DECREASE
TO LESS THAN 5 KNOTS AFTER 01Z AT ALL OF THE TAF SITES WHILE
REMAINING FROM THE EAST DIRECTION.
THE WEATHER WILL ALSO REMAIN DRY OVER ALL OF THE TAF SITES ACROSS
SOUTH FLORIDA THIS AFTERNOON INTO TONIGHT...AS ANY AFTERNOON AND
EVENING SHOWERS AND THUNDERSTORMS SHOULD AFFECT THE INTERIOR
AREAS. THE CEILING AND VIS WILL ALSO REMAIN IN THE VFR CONDITIONS
THROUGH TONIGHT AT ALL OF THE TAF SITES IN SOUTH FLORIDA.
&&
.MARINE...
CONDITIONS SHOULD REMAIN FAIRLY QUIET INTO THE BEGINNING OF THE
WEEK. THE BERMUDA HIGH IS FORECAST TO STRENGTHEN, WHICH COULD
ALLOW SEAS TO BUILD BY MID WEEK. OTHERWISE, EASTERLY WINDS WILL
KICK IN BY THE BEGINNING OF THE WEEK FOR THE ATLANTIC WATERS.
THERE IS A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY.
&&
.FIRE WEATHER...
THERE IS AN UPPER LEVEL RIDGE THAT IS BUILDING OVER SOUTH FLORIDA.
THIS SHOULD LEAD TO INCREASING STABILITY FOR A COUPLE OF DAYS. THE
BERMUDA HIGH WILL STRENGTHEN FOR THE BEGINNING OF THE WEEK,
ALLOWING AN EASTERLY FLOW TO BEGIN TO BEING MORE MOISTURE BACK
INTO THE AREA, AND THUS MORE CONVECTIVE ACTIVITY NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 75 85 75 87 / 20 20 10 20
FORT LAUDERDALE 78 87 78 88 / 10 20 10 20
MIAMI 78 88 77 89 / 10 20 10 20
NAPLES 76 89 75 92 / 10 30 20 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...13/SI
AVIATION/RADAR...54/BNB
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
145 PM EDT SAT JUN 15 2013
.SYNOPSIS...
17Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS OUR REGION UNDER UPPER
LEVEL RIDGING BUILDING ACROSS THE NORTHERN GULF OF MEXICO IN THE
WAKE OF A DEPARTING LONG WAVE TROUGH. THIS RIDGE WILL BE OVER OUR
HEADS THROUGH THE REMAINDER OF THE WEEKEND BEFORE FLOW BECOMES MORE
ZONAL IN NATURE DURING THE EARLY PORTION OF NEXT WEEK.
AT THE SURFACE...A WEAK FRONTAL BOUNDARY HAS BEEN SLOWLY SAGGING
SOUTHWARD ALONG THE NATURE COAST ZONES THIS MORNING AND IS NOW
ALIGNED NEAR THE I-4 CORRIDOR. THIS FRONT WILL NOT MAKE MUCH MORE
PROGRESS SOUTHWARD AND GENERALLY DISSIPATE THROUGH THE NEXT 12-18
HOURS. A SCATTERING OF SHOWERS AND STORMS HAVE CONTINUED WITHIN THE
FRONTAL FOCUS BAND ACROSS THE NATURE COAST THE PAST FEW HOURS AND
NOW SEEING DEVELOPMENT EXTEND SOUTHWARD INTO POLK COUNTY.
&&
.SHORT TERM (TONIGHT THROUGH MONDAY)...
REST OF TODAY...THE INTERACTION OF THE SEA-BREEZE AND THE DECAYING
FRONT WILL CONTINUE TO PRODUCE A SCATTERING OF SHOWERS AND STORMS
INTO THE EVENING HOURS. BEST CONCENTRATION OF STORMS LOOKS TO BE
ALONG AND NEAR THE I-4/NATURE COAST ZONES WITH MORE ISOLATED
ACTIVITY SOUTHWARD TOWARD FORT MYERS.
TONIGHT...LINGERING SHOWERS AND STORMS DISSIPATE WITH THE LOSS OF
DIURNAL HEATING BY AROUND MIDNIGHT. UNTIL THE FRONTAL FOCUS IS
COMPLETELY GONE...CAN NOT RULE OUT A FEW SHOWERS AND WILL HOLD AT
LEAST A 20% RAIN CHANCE IN THE GRIDS THROUGH THE EVENING.
SUNDAY/MONDAY...
A TYPICAL SUMMER-LIKE PATTERN WILL DEVELOP OVER THE REGION.
SUBTROPICAL RIDGE AXIS IS SHOWN BY GLOBAL GUIDANCE TO EXTEND ACROSS
THE CENTRAL FL PENINSULA WITH UPPER LEVEL RIDGING ON SUNDAY GIVING
WAY TO A MORE ZONAL/WEAKER RIDGE BY THE EARLY PORTION OF NEXT WEEK.
THE WEAKER GRADIENT WILL ALLOW WELL-DEFINED EAST AND WEST COAST
SEA-BREEZES THE NEXT COUPLE OF DAYS. WITH NO DOMINANT
SEA-BREEZE...SHOWERS AND STORM DEVELOPING NEAR THE COAST EARLY IN
THE AFTERNOON SHOULD MIGRATE INLAND AND CONGEAL BY THE LATE
AFTERNOON/EVENING HOURS. WITH THIS IN MIND WILL HAVE HIGHEST POPS
GENERALLY INLAND FROM THE I-75 CORRIDOR. FOR THOSE WITH EXTENDED
OUTDOOR ACTIVITIES PLANNED...TEMPERATURES AND DEWPOINTS WILL COMBINE
TO PRODUCE HEAT INDICES BETWEEN 98-103 THE NEXT COUPLE OF DAYS.
&&
.LONG TERM (TUESDAY-SATURDAY)...
MEDIUM RANGE GUIDANCE REMAINS IN GOOD AGREEMENT SHOWING ATLANTIC
HIGH PRESSURE HOLDING IN PLACE THROUGH THE PERIOD. THE RIDGE AXIS
WILL MEANDER NORTH AND SOUTH ACROSS THE FLORIDA PENINSULA THROUGH
THE PERIOD...BUT GENERALLY EXPECT A TYPICAL SUMMERTIME REGIME WITH
SCATTERED MAINLY AFTERNOON/EARLY EVENING SHOWERS AND THUNDERSTORMS
EACH DAY. TEMPERATURES WILL HOLD CLOSE TO SEASONAL LEVELS THROUGH
THE PERIOD.
&&
.AVIATION...
PREVAILING VFR WITH SOME BKN CIGS AOA 3500FT. BUT EXPECT TSRA
AT/NEAR TERMINALS...WITH MVFR IN TSRA AT TPA/PIE/LAL/SRO. HAVE OPTED
TO KEEP PGD/FMY/RSW JUST VCNTY. WESTERLY WINDS BECOME LIGHT AND
VARIABLE OR EASTERLY OVERNIGHT THEN SOUTHEAST LATE SUN MORNING.
&&
.MARINE...
WEAK FRONTAL BOUNDARY OVER THE NORTHERN WATERS WILL DISSIPATE
THROUGH THE OVERNIGHT ALLOWING THE SUBTROPICAL RIDGE TO BUILD BACK
OVER THE EASTERN GULF OF MEXICO THROUGH THE MIDDLE PORTION OF THE
WEEK. 10 TO 15 KNOTS OF EASTERLY FLOW IS EXPECTED TO DEVELOP TONIGHT
TO THE NORTH OF TAMPA BAY BEHIND THE DECAYING FRONT. THEREAFTER FOR
SUNDAY AND MONDAY...WINDS WILL BE GENERALLY LIGHT AND VARIABLE
OUTSIDE OF STEADIER ONSHORE FLOW NEAR THE COAST EACH AFTERNOON WITH
THE SEA-BREEZE.
&&
.FIRE WEATHER...
A WEAK FRONTAL BOUNDARY ACROSS THE PENINSULA WILL WASH OUT THROUGH
TONIGHT AND SET UP A TYPICAL SUMMER PATTERN FOR THE REGION THROUGH
THE EARLY PORTION OF THE WEEK. ABUNDANT LOW LEVEL MOISTURE SHOULD
PREVENT CRITICAL LEVELS OF RELATIVE HUMIDITY WITH A NORMAL
DISTRIBUTION OF MAINLY AFTERNOON AND EVENING STORMS.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 76 91 77 91 / 30 30 20 30
FMY 76 93 75 92 / 20 40 20 40
GIF 74 94 73 94 / 30 50 30 40
SRQ 75 89 76 89 / 20 20 20 20
BKV 73 92 72 92 / 30 40 20 40
SPG 78 90 78 90 / 30 30 20 30
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/MARINE/FIRE WX...MROCZKA
LONG TERM...JELSEMA
AVIATION...RUDE
AREA FORECAST DISCUSSION
NWS MIAMI FL
950 AM EDT SAT JUN 15 2013
.UPDATE...
MORNING SOUNDING SHOWING PWATS HAVE DROPPED TO ABOUT 1.5 INCHES
AND 500 MB TEMP IS ABOUT -6. ALSO, IT SHOWS THERE IS A CAP AT
ABOUT 550MB. MODEL SOUNDINGS SHOW THAT PWATS WILL SLOWLY DROP FROM
HERE AS WELL AS 500MB TEMPS WARMING AND A STRENGTHENING CAP. THERE
IS STILL CAPE OF AROUND 3000 JOULES. LAPSE RATES ARE LOWER THAN
YESTERDAY. GIVEN ALL THIS, HAVE BACKED OF ON POPS FOR MOST OF
SOUTH FLORIDA, AS WELL AS LOWERED SKY COVER PERCENTAGES TODAY.
WHILE THERE COULD STILL BE SOME SHOWERS AND THUNDERSTORMS, SHOWED
BE LESS COVERAGE THAN YESTERDAY, AND PROBABLY MORE POSSIBLE AROUND
THE LAKE REGION.
&&
.PREV DISCUSSION... /ISSUED 724 AM EDT SAT JUN 15 2013/
AVIATION...
A WEAK WESTERLY TO NORTHWESTERLY FLOW CONTINUES ACROSS THE REGION
WHICH WILL HELP TO DELAY THE ON-SET OF THE EAST COAST SEA BREEZE.
THE TAF`S INDICATE EAST COAST SEA BREEZE STARTING AT 16Z BUT COULD
BE DELAYED EVEN FURTHER TO 18-19Z. CONVECTION IS FORECAST TO BE
MAINLY INLAND OF THE TERMINALS WITH VCSH ASSIGNED ALL TERMINALS
AROUND 16Z BUT ON-SET OF SHOWERS/THUNDERSTORMS COULD BE EVEN FURTHER
DELAYED TO AROUND 18-19Z. MAINLY VFR CONDITIONS EXPECTED TO PREVAIL
THROUGH AT LEAST 16Z.
AVIATION...BNB/BD
PREV DISCUSSION... /ISSUED 428 AM EDT SAT JUN 15 2013/
DISCUSSION...A COLD FRONT OVER NORTH FLORIDA WILL SLIDE SOUTHWARD
INTO CENTRAL FLORIDA THIS AFTERNOON WHILE DISSIPATING. CONVECTION
CONTINUES ALONG THIS BOUNDARY OVER NORTH CENTRAL FL. THE MODEL
CONSENSUS KEEPS THIS MORE ORGANIZED ACTIVITY OVER CENTRAL FL THIS
AFTERNOON...FOCUSING TSTMS OVER WEST CENTRAL FL ASSOCIATED WITH
THE AFOREMENTIONED BOUNDARY AND GULF SEA BREEZE INFLUENCES. ACROSS
SOUTH FLORIDA, ACTIVITY IS EXPECTED TO BE LESS AS THE ATMOSPHERE
HAS DRIED OUT COMPARED TO YESTERDAY WITH GPS MET DATA SHOWING
PWATS NOW AROUND 1.5 INCHES ON AVERAGE ACROSS THE AREA. WHILE
GLOBAL MODELS POINT TO NEGLIGIBLE POPS TODAY, THE HRRR AND SREF SHOW
CONVECTION DEVELOPING AS SEA BREEZES DEVELOP THIS AFTERNOON. GIVEN
THE STRONG HEATING AND STILL SUFFICIENT MOISTURE, ALBEIT LOWER
THAN RECENT DAYS, HAVE SIDED WITH THE HIGHER RESOLUTION
MODELS DEPICTING ISOLATED TSTMS ALONG BOTH COASTS WITH
SCATTERED TSTMS OVER THE INTERIOR. WARMING ALOFT AS A GULF RIDGE
BUILDS IN WILL LEAD TO WEAKER LAPSE RATES COMPARED TO YESTERDAY, SO
STORMS ARE FORECAST TO BE LESS INTENSE, THOUGH A FEW STRONG STORMS
ARE STILL POSSIBLE.
WHAT`S LEFT OF THE BOUNDARY WILL EDGE SOUTHWARD TO THE LAKE REGION
TONIGHT-SUNDAY. STEERING FLOW IS MORE EASTERLY ON SUNDAY, SO
CONVECTION IS FORECAST TO FOCUS ACROSS THE WESTERN INTERIOR AND
GULF COAST.
A TROPICAL WAVE OVER HISPANIOLA IS FORECAST TO PASS SOUTH OF THE
AREA EARLY NEXT WEEK. LOW LEVEL WINDS TURN SOUTH-SOUTHEAST TUE-WED
WITH GRADUAL MOISTENING MID WEEK. TYPICAL SCATTERED MAINLY
AFTERNOON TSTMS ARE EXPECTED. THEN DRYING LOOKS TO OCCUR THU-FRI
AS BOTH GFS AND ECMWF SHOW A SAHARAN AIR LAYER (SAL) MOVING INTO
SOUTH FLORIDA DURING THIS TIME. THIS IS EXPECTED TO RESULT IN
HAZY SKIES ACROSS SOUTH FL WITH LESS TSTM COVERAGE, BUT
POTENTIALLY STRONGER STORMS GIVEN STEEPING LAPSE RATES OF THE
SAL...BUT THIS WOULD BE DEPENDENT ON IF THERE IS SUFFICIENT
MOISTURE PRESENT. TOO FAR OFF IN TIME TO MAKE THAT CALL.
MARINE...SOUTHWEST WINDS WILL BECOME NORTHEAST-EAST THIS
AFTERNOON, EXCEPT WESTERLY ALONG THE GULF COAST IN THE AFTERNOON
AS THE GULF BREEZE DEVELOPS. WINDS NEXT WEEK WILL PREDOMINATE OUT
OF THE EAST SOUTHEAST. SPEEDS WILL CONTINUE LESS THAN 15 KT WITH
LOW SEAS EXPECTED TO CONTINUE.
FIRE WEATHER...NO CONCERNS AS RELATIVE HUMIDITIES REMAIN
TYPICALLY HIGH FOR THIS TIME OF THE YEAR.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 87 75 85 75 / 20 20 20 10
FORT LAUDERDALE 89 78 87 78 / 20 10 20 10
MIAMI 90 78 88 77 / 20 10 20 10
NAPLES 89 76 89 75 / 10 10 30 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...13/SI
AVIATION/RADAR...60/BD
AREA FORECAST DISCUSSION...UPDATED
NWS MIAMI FL
724 AM EDT SAT JUN 15 2013
.AVIATION...
A WEAK WESTERLY TO NORTHWESTERLY FLOW CONTINUES ACROSS THE REGION
WHICH WILL HELP TO DELAY THE ON-SET OF THE EAST COAST SEA BREEZE.
THE TAF`S INDICATE EAST COAST SEA BREEZE STARTING AT 16Z BUT COULD
BE DELAYED EVEN FURTHER TO 18-19Z. CONVECTION IS FORECAST TO BE
MAINLY INLAND OF THE TERMINALS WITH VCSH ASSIGNED ALL TERMINALS
AROUND 16Z BUT ON-SET OF SHOWERS/THUNDERSTORMS COULD BE EVEN FURTHER
DELAYED TO AROUND 18-19Z. MAINLY VFR CONDITIONS EXPECTED TO PREVAIL
THROUGH AT LEAST 16Z.
&&
.AVIATION...BNB/BD
.PREV DISCUSSION... /ISSUED 428 AM EDT SAT JUN 15 2013/
DISCUSSION...A COLD FRONT OVER NORTH FLORIDA WILL SLIDE SOUTHWARD
INTO CENTRAL FLORIDA THIS AFTERNOON WHILE DISSIPATING. CONVECTION
CONTINUES ALONG THIS BOUNDARY OVER NORTH CENTRAL FL. THE MODEL
CONSENSUS KEEPS THIS MORE ORGANIZED ACTIVITY OVER CENTRAL FL THIS
AFTERNOON...FOCUSING TSTORMS OVER WEST CENTRAL FL ASSOCIATED WITH
THE AFOREMENTIONED BOUNDARY AND GULF SEA BREEZE INFLUENCES. ACROSS
SOUTH FLORIDA, ACTIVITY IS EXPECTED TO BE LESS AS THE ATMOSPHERE
HAS DRIED OUT COMPARED TO YESTERDAY WITH GPS MET DATA SHOWING
PWATS NOW AROUND 1.5 INCHES ON AVERAGE ACROSS THE AREA. WHILE
GLOBAL MODELS POINT TO NEGLIGIBLE POPS TODAY, THE HRRR AND SREF SHOW
CONVECTION DEVELOPING AS SEA BREEZES DEVELOP THIS AFTERNOON. GIVEN
THE STRONG HEATING AND STILL SUFFICIENT MOISTURE, ALBEIT LOWER
THAN RECENT DAYS, HAVE SIDED WITH THE HIGHER RESOLUTION
MODELS DEPICTING ISOLATED TSTORMS ALONG BOTH COASTS WITH
SCATTERED TSTORMS OVER THE INTERIOR. WARMING ALOFT AS A GULF RIDGE
BUILDS IN WILL LEAD TO WEAKER LAPSE RATES COMPARED TO YESTERDAY, SO
STORMS ARE FORECAST TO BE LESS INTENSE, THOUGH A FEW STRONG STORMS
ARE STILL POSSIBLE.
WHAT`S LEFT OF THE BOUNDARY WILL EDGE SOUTHWARD TO THE LAKE REGION
TONIGHT-SUNDAY. STEERING FLOW IS MORE EASTERLY ON SUNDAY, SO
CONVECTION IS FORECAST TO FOCUS ACROSS THE WESTERN INTERIOR AND
GULF COAST.
A TROPICAL WAVE OVER HISPANIOLA IS FORECAST TO PASS SOUTH OF THE
AREA EARLY NEXT WEEK. LOW LEVEL WINDS TURN SOUTH-SOUTHEAST TUE-WED
WITH GRADUAL MOISTENING MID WEEK. TYPICAL SCATTERED MAINLY
AFTERNOON TSTORMS ARE EXPECTED. THEN DRYING LOOKS TO OCCUR THU-FRI
AS BOTH GFS AND ECMWF SHOW A SAHARAN AIR LAYER (SAL) MOVING INTO
SOUTH FLORIDA DURING THIS TIME. THIS IS EXPECTED TO RESULT IN
HAZY SKIES ACROSS SOUTH FL WITH LESS TSTORM COVERAGE, BUT
POTENTIALLY STRONGER STORMS GIVEN STEEPING LAPSE RATES OF THE
SAL...BUT THIS WOULD BE DEPENDENT ON IF THERE IS SUFFICIENT
MOISTURE PRESENT. TOO FAR OFF IN TIME TO MAKE THAT CALL.
MARINE...SOUTHWEST WINDS WILL BECOME NORTHEAST-EAST THIS
AFTERNOON, EXCEPT WESTERLY ALONG THE GULF COAST IN THE AFTERNOON
AS THE GULF BREEZE DEVELOPS. WINDS NEXT WEEK WILL PREDOMINATE OUT
OF THE EAST SOUTHEAST. SPEEDS WILL CONTINUE LESS THAN 15 KT WITH
LOW SEAS EXPECTED TO CONTINUE.
FIRE WEATHER...NO CONCERNS AS RELATIVE HUMIDITIES REMAIN
TYPICALLY HIGH FOR THIS TIME OF THE YEAR.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 89 77 87 78 / 20 10 20 20
FORT LAUDERDALE 88 79 88 80 / 20 10 20 20
MIAMI 90 79 89 79 / 20 10 20 20
NAPLES 92 76 92 75 / 20 10 40 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...57/DG
AVIATION/RADAR...60/BD
AREA FORECAST DISCUSSION
NWS MIAMI FL
428 AM EDT SAT JUN 15 2013
.DISCUSSION...A COLD FRONT OVER NORTH FLORIDA WILL SLIDE SOUTHWARD
INTO CENTRAL FLORIDA THIS AFTERNOON WHILE DISSIPATING. CONVECTION
CONTINUES ALONG THIS BOUNDARY OVER NORTH CENTRAL FL. THE MODEL
CONSENSUS KEEPS THIS MORE ORGANIZED ACTIVITY OVER CENTRAL FL THIS
AFTERNOON...FOCUSING TSTORMS OVER WEST CENTRAL FL ASSOCIATED WITH
THE AFOREMENTIONED BOUNDARY AND GULF SEA BREEZE INFLUENCES. ACROSS
SOUTH FLORIDA, ACTIVITY IS EXPECTED TO BE LESS AS THE ATMOSPHERE
HAS DRIED OUT COMPARED TO YESTERDAY WITH GPS MET DATA SHOWING
PWATS NOW AROUND 1.5 INCHES ON AVERAGE ACROSS THE AREA. WHILE
GLOBAL MODELS POINT TO NEGLIGIBLE POPS TODAY, THE HRRR AND SREF SHOW
CONVECTION DEVELOPING AS SEA BREEZES DEVELOP THIS AFTERNOON. GIVEN
THE STRONG HEATING AND STILL SUFFICIENT MOISTURE, ALBEIT LOWER
THAN RECENT DAYS, HAVE SIDED WITH THE HIGHER RESOLUTION
MODELS DEPICTING ISOLATED TSTORMS ALONG BOTH COASTS WITH
SCATTERED TSTORMS OVER THE INTERIOR. WARMING ALOFT AS A GULF RIDGE
BUILDS IN WILL LEAD TO WEAKER LAPSE RATES COMPARED TO YESTERDAY, SO
STORMS ARE FORECAST TO BE LESS INTENSE, THOUGH A FEW STRONG STORMS
ARE STILL POSSIBLE.
WHAT`S LEFT OF THE BOUNDARY WILL EDGE SOUTHWARD TO THE LAKE REGION
TONIGHT-SUNDAY. STEERING FLOW IS MORE EASTERLY ON SUNDAY, SO
CONVECTION IS FORECAST TO FOCUS ACROSS THE WESTERN INTERIOR AND
GULF COAST.
A TROPICAL WAVE OVER HISPANIOLA IS FORECAST TO PASS SOUTH OF THE
AREA EARLY NEXT WEEK. LOW LEVEL WINDS TURN SOUTH-SOUTHEAST TUE-WED
WITH GRADUAL MOISTENING MID WEEK. TYPICAL SCATTERED MAINLY
AFTERNOON TSTORMS ARE EXPECTED. THEN DRYING LOOKS TO OCCUR THU-FRI
AS BOTH GFS AND ECMWF SHOW A SAHARAN AIR LAYER (SAL) MOVING INTO
SOUTH FLORIDA DURING THIS TIME. THIS IS EXPECTED TO RESULT IN
HAZY SKIES ACROSS SOUTH FL WITH LESS TSTORM COVERAGE, BUT
POTENTIALLY STRONGER STORMS GIVEN STEEPING LAPSE RATES OF THE
SAL...BUT THIS WOULD BE DEPENDENT ON IF THERE IS SUFFICIENT
MOISTURE PRESENT. TOO FAR OFF IN TIME TO MAKE THAT CALL.
&&
.MARINE...SOUTHWEST WINDS WILL BECOME NORTHEAST-EAST THIS
AFTERNOON, EXCEPT WESTERLY ALONG THE GULF COAST IN THE AFTERNOON
AS THE GULF BREEZE DEVELOPS. WINDS NEXT WEEK WILL PREDOMINATE OUT
OF THE EAST SOUTHEAST. SPEEDS WILL CONTINUE LESS THAN 15 KT WITH
LOW SEAS EXPECTED TO CONTINUE.
&&
.FIRE WEATHER...NO CONCERNS AS RELATIVE HUMIDITIES REMAIN
TYPICALLY HIGH FOR THIS TIME OF THE YEAR.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 89 77 87 78 / 20 10 20 20
FORT LAUDERDALE 88 79 88 80 / 20 10 20 20
MIAMI 90 79 89 79 / 20 10 20 20
NAPLES 92 76 92 75 / 20 10 40 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...57/GREGORIA
AVIATION/RADAR...60/BD
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
806 PM EDT SUN JUN 16 2013
.SYNOPSIS...
HIGH PRESSURE OVER THE AREA WILL WEAKEN OVERNIGHT. A WEAK SYSTEM
WILL APPROACH FROM THE WEST MONDAY BRINGING A SLOW MOVING COLD
FRONT AND INCREASING THE MOISTURE ACROSS THE REGION MONDAY
THROUGH TUESDAY. AN INCREASE IN THE CHANCES OF SHOWERS AND
THUNDERSTORMS IS ALSO EXPECTED MONDAY THROUGH TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
CURRENT VISIBLE SATELLITE IMAGERY SHOWING MAJORITY OF DIURNAL CU
HAS DISSIPATED WITH SKIES BECOMING MOSTLY CLEAR. CLOUD COVER WILL
INCREASE FROM WEST TO EAST OVERNIGHT ASSOCIATED WITH AN
APPROACHING SHORTWAVE. INCREASING CLOUDS WILL PREVENT TEMPS FROM
DROPPING AS LOW AS THE PAST COUPLE OF NIGHTS...WITH NEAR NORMAL
LOWS IN THE UPPER 60S EXPECTED. GUIDANCE IS IN GOOD AGREEMENT WITH
TEMPS. HIGH PRESSURE WILL CONTINUE TO RETREAT FURTHER INTO THE
ATLANTIC THROUGH MONDAY MORNING. INCREASING POP TREND OVERNIGHT AS
THE SHORTWAVE MOVES TOWARD THE AREA.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
A MID-UPPER LEVEL TROUGH WILL MOVE INTO THE REGION MONDAY
THROUGH TUESDAY WITH A COUPLE WEAK SHORT WAVES TRAVERSING
THE AREA MONDAY AND AGAIN ON TUESDAY. IN ADDITION...INCREASING
LOW LEVEL SOUTHWEST WIND FLOW WILL ADVECT MOISTURE INTO THE
FORECAST AREA. ALONG WITH THE INCREASE IN MOISTURE...THERE
WILL BE OVERNIGHT LOW CLOUDS IN THE FORM OF STRATUS BOTH
MONDAY MORNING AND TUESDAY MORNING. DAYTIME HEATING WILL
HELP BREAK UP THE LOW CLOUD DECK BUT THERE SHOULD BE PLENTY
OF MOISTURE FOR SHOWERS AND THUNDERSTORMS TO DEVELOP BOTH
MONDAY AND TUESDAY. PLAN ON CONTINUING THE 40-50 PERCENT
CHANCE OF SHOWERS AND THUNDERSTORMS MONDAY THROUGH TUESDAY.
CLOUDS ARE EXPECTED TO HOLD HIGHS BELOW 90 IN THE UPPER 80S
MONDAY AND MORE CLOUDS ON TUESDAY SHOULD HOLD HIGHS INTO THE
MIDDLE 80S. OVERNIGHT LOWS MONDAY NIGHT SHOULD BE RIGHT AROUND
70 AND IN THE LOWER 70S TUESDAY NIGHT. IN ADDITION...RAIN
CHANCES CONTINUE NEAR 40 PERCENT TUESDAY NIGHT.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
THE GFS AND ECMWF APPEAR TO BE IN PRETTY GOOD AGREEMENT
WEDNESDAY THROUGH SUNDAY. THE MID-UPPER LEVEL TROUGH REMAINS
NEAR THE EAST COAST AT LEAST THROUGH FRIDAY...THEN AN UPPER
RIDGE TO THE WEST TRIES TO NUDGE IN FOR THE WEEKEND. HOWEVER
THERE APPEARS TO BE A CHANCE OF SHOWERS AND THUNDERSTORMS
EACH DAY. THE HIGHEST CHANCES ARE EARLY IN THE PERIOD
WEDNESDAY THROUGH FRIDAY WITH A 30-40 PERCENT CHANCE. AS
THE UPPER RIDGE TRIES TO BUILD EAST...RAIN CHANCES DROP
A BIT TO 20-30 PERCENT FOR SATURDAY AND SUNDAY AND THE
CONVECTIVE ACTIVITY SHOULD BECOME MORE DIURNAL OR SUMMER
LIKE IN NATURE. HIGHS ARE A BIT BELOW NORMAL MAINLY IN
THE MIDDLE 80S WEDNESDAY AND THURSDAY BUT INCREASE TO
THE UPPER 80S BY SATURDAY AND SUNDAY BUT THERE MAY BE
A FEW 90S AROUND SUNDAY DEPENDING ON THE AMOUNT OF SUNSHINE.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
A FEW SHOWERS OVER N GA...WITH MORE ACTIVITY OVER N ALA. A WEAK
UPPER IMPULSE MAY PROVIDE SOME SHOWER ACTIVITY EASTWARD INTO NE
GA/UPSTATE SC LATE TODAY AND THIS EVENING...BUT EXPECT IT TO REMAIN
NORTH OF OUR TERMINALS. DEWPOINTS THIS AFTERNOON OVER OUR FA RAN
ABOUT 7-8 DEGREES HIGHER THAN YESTERDAY...WHICH WOULD PROVIDE SOME
CONCERN OVER RADIATION FOG POTENTIAL LATE TONIGHT/EARLY MONDAY.
HOWEVER...BUFKIT INDICATES A 25 KNOT BOUNDARY LAYER FLOW DEVELOPING
FROM THE SW...WHICH WOULD WORK AGAINST FOG FORMATION...BUT COULD
CONTRIBUTE TO SOME STRATUS FORMATION...THOUGH A SW DIRECTION IS
TYPICALLY NOT THE MOST FAVORABLE DIRECTION FOR STRATUS. LATEST MOS
BULLETINS AND GFS LAMP SUGGESTING SOME STRATUS POSSIBLE...WITH
MAINLY MVFR CIGS. LAMP ALSO INDICATING MVFR VSBY POTENTIAL AT FOG
PRONE AGS/OGB. LATEST RAP SUGGESTING IFR CIG POTENTIAL AT
DNL/AGS...WITH NO RESTRICTIONS ELSEWHERE. FOR NOW...WILL MAINTAIN
MENTION OF MVFR CONDITIONS LATE TONIGHT/EARLY MONDAY. AFTER ANY
MORNING RESTRICTIONS...VFR EXPECTED MONDAY OUTSIDE OF ANY
CONVECTION. A DEEPENING UPPER TROUGH AND INCREASING ATMOSPHERIC
MOISTURE IS EXPECTED TO LEAD TO SCATTERED THUNDERSTORMS MONDAY
AFTERNOON...MAINLY AFTER 18Z. CHANCES OF IT AFFECTING TERMINALS TOO
LOW TO INCLDUE MENTION IN THE TAFS AT THIS TIME.
EXTENDED AVIATION OUTLOOK...CHANCE OF MAINLY AFTERNOON/EVENING
THUNDERSTORMS. CHANCE OF LATE NIGHT/EARLY MORNING FOG/STRATUS.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
534 PM CDT SAT JUN 15 2013
.MESOSCALE DISCUSSION...
317 PM CDT
CONTINUING TO MONITOR CONVECTIVE TRENDS EARLY THIS AFTERNOON.
STILL PLENTY OF UNCERTAINTY REGARDING EXTENT OF SEVERE THREAT BUT
CURRENT SATELLITE AND SURFACE OBS AND MESO-ANALYSIS GIVE SOME
HINT AT HOW THINGS MIGHT PLAY OUT. MCV ASSOCIATED WITH LATE
MORNING COMPLEX CURRENTLY PIVOTING SOUTHEAST FROM EASTERN
CWA...WITH BREAKS IN CLOUDS DEVELOPING ON BACK SIDE OF MCV.
EASTERN HALF OF CWA IS QUITE STABLE INITIALLY...BUT RECOVERY OF
DEW POINTS INTO MID AND UPPER 60S INTO WEST AND SOUTHWEST
CWA...ALONG WITH TEMPERATURES ALREADY WARMING INTO UPPER 70S TO
AROUND 80 HAS RENEWED DESTABILIZATION PROCESS FOR THESE AREAS.
RAP IS MOST BULLISH/LIKELY TOO BULLISH ON MLCAPE VALUES BY LATE
AFTERNOON...BUT EVEN NAM SUPPORTS ML CAPES OF ABOUT 1000-1500
J/KG BY LATE AFTERNOON OVER THE WESTERN CWA...WITH MINIMAL TO NO
CAPPING BY THEN AND ONLY MINIMAL CAPPING RETURNING BY EARLY
EVENING.
EXPECT THE COMPLEX OVER WEST CENTRAL ILLINOIS TO BE STEERED SOUTH
OF THE CWA...WITH THE LIKELY FOCUS FOR ROBUST DEVELOPMENT IN THE
LATE AFTERNOON INTO THE EVENING TO BE THE WAVE NOTED ON W/V AND
RADAR OVER NORTH CENTRAL IOWA. HI RES MODELS SUCH AS SPC-WRF NMM
AND HRRR SEEM TO HAVE A DECENT HANDLE ON TRENDS AND SHOW CLUSTER
OR CLUSTERS DEVELOPING SOUTH OF THE CURRENTLY WEAKENING
CONVECTION OVER NORTH CENTRAL IOWA OVER EASTERN IOWA AND NORTHERN
MO. THESE THEN FOLLOW THE 850-300 MB THICKNESS LINES EAST OR EAST-
SOUTHEAST FROM WESTERN ILLINOIS BY THE LATE AFTERNOON AND EARLY
EVENING (23Z-01Z) TO NORTHEAST IL AND NORTHWEST INDIANA A FEW
HOURS LATER (02-04Z).
0-6 KM BULK SHEAR STRENGTHENING TO 40 TO AS MUCH AS 50 KT BY
EARLY EVENING WILL SUPPORT ORGANIZATION...AND INCREASING LOW
LEVEL JET/0-3 KM SHEAR COULD RESULT IN DAMAGING WIND THREAT.
ALSO...MID LEVEL LAPSE RATES STEEPENING FROM THE WEST WITH
APPROACH OF WAVE COULD PRESENT A SEVERE HAIL THREAT...MAINLY FOR
NORTH CENTRAL IL AND POINTS WEST. THINK THAT COMPLEX WILL BE ON
WEAKENING TREND AS IT HEADS EAST INTO NORTHEAST IL AND NW INDIANA
DUE TO LOWER AND DIMINISHING INSTABILITY BY THAT TIME...BUT STILL
CAN FORESEE LIGHTNING AND GUSTY WINDS AFFECTING OUTDOOR EVENTS
OVER THESE AREAS. IN ADDITION...MORE INTENSE STORMS TODAY OVER
REGION HAVE PRODUCED VERY HEAVY RAINFALL WITH PWAT OVER 1.5
INCHES AND WITH 850 MB MOISTURE TRANSPORT INCREASING THIS
EVENING...IMPRESSIVE RAINFALL RATES AND LOCALIZED FLASH FLOODING
ARE CERTAINLY POSSIBLE. FINALLY...SOME CONCERN THAT THE
INCREASING 850 MB MOISTURE TRANSPORT AND FLOW COULD ALSO MAINTAIN
SEVERE THREAT FARTHER EAST THAN CURRENTLY EXPECTED...SO WILL
CONTINUE TO MONITOR THIS POSSIBILITY AS WELL. THIS IS SOMETHING
THAT THE LATEST 17Z HRRR SHOWS.
RC
&&
.DISCUSSION...
306 PM CDT
THIS EVENING AND TONIGHT...
FOR A SPECIFIC DISCUSSION OF THE FORECAST THROUGH EARLY THIS
EVENING SEE THE MESOSCALE DISCUSSION ABOVE.
THE WEAKENING LINE OF STORMS WILL CONTINUE TO MOVE ESE THROUGH
THE EVENING AND OVERNIGHT. HEAVY RAIN AND LIGHTNING WILL BE THE
PRIMARY THREATS LATER THIS EVENING WITH GUSTY WINDS PSBL. FLASH
FLOODING WILL ALSO NOT BE OUTSIDE OF THE REALM OF POSSIBILITY.
DESPITE THE LINE OF SHOWERS AND STORMS MOVING THROUGH...STILL
LOOKING LIKE A SOUPY NIGHT WITH TEMPS IN THE MID TO UPPER 60S AND
DEW POINTS ABOUT THE SAME. PUT AREAS OF FOG IN THE FORECAST
BEHIND THE RAIN...BUT NOT EXPECTING WIDESPREAD FOG DEVELOPMENT.
SUNDAY AND MONDAY...
THE CLOSED UPPER LEVEL LOW CURRENTLY OVER SASKATCHEWAN WEAKENS
AND MOVES INTO NORTH DAKOTA SUNDAY EVENING. IT THEN BECOMES
ABSORBED BY A STRONGER TROUGH OVER JAMES BAY SUNDAY NIGHT...AND
THE TROUGH AXIS PASSES OVERHEAD MONDAY NIGHT. AT THE SURFACE...
THE LOW ALSO OVER SASKATCHEWAN EXPANDS OVER THE GREAT LAKES AND
THEN CONTINUES EASTWARD MOVING OVER NEW ENGLAND BY LATE SUNDAY
NIGHT.
THINKING THERE MAY BE A FEW LINGERING SHOWERS...SO HAVE SLIGHT
CHANCE TO CHANCE POPS FOR AREAS SOUTH OF A GARY TO STREATOR LINE.
THE SHOWERS SHOULD EXIT TO THE SOUTHEAST DURING THE DAY AS THE
SHORTWAVE SHIFTS EAST. THEN EXPECTING SHOWERS AND THUNDERSTORMS
TO FORM OVER THE NORTH END OF LAKE MICHIGAN SUNDAY AFTN/EVENING
AS THE LOW EXPANDS. THINKING SHOWERS AND STORMS WILL NOT REACH
NORTHERN IL/IN UNTIL MONDAY. HAVE CHANCE POPS BEGINNING MONDAY
MORNING...BUT CONFIDENCE IS LOW IN EXACT TIMING. THINKING SHOWERS
AND TS COULD POSSIBLY BE A BIT DELAYED AND NOT ARRIVE UNTIL THE
MORNING/EARLY AFTN. THE SYSTEM KEEPS PUSHING SOUTH WITH SHOWERS
AND STORMS SOUTH OF THE CWA LATE MONDAY NIGHT. PWATS WILL BE
AROUND AN INCH THROUGHOUT THE EVENT SO A DECENT SOAKING RAIN IS
VERY POSSIBLE...BUT HEAVY RAIN LIKE WE HAVE EXPERIENCED WITH THE
PAST FEW SYSTEMS IS NOT LIKELY.
FOR TEMPS...DID NOT MAKE TOO MANY ADJUSTMENTS TO THE PREVIOUS
HIGH TEMPS FOR SUNDAY. NOT SURE HOW QUICKLY THE SKIES WILL CLEAR
TOMORROW WITH HIGHER TEMPS EXPECTED IF WE CLEAR QUICKER THAN
INDICATED. LOW TO MID 80S ARE EXPECTED AT LEAST...WITH OVERNIGHT
LOWS IN THE 60S. LOWS WILL BE WARMER DOWNTOWN AND SOUTH OF I-80.
HIGH TEMPS ON MONDAY WILL GET INTO THE LOW TO MID 80S AGAIN BUT
EXPECTING A SIGNIFICANT COOLING TREND MONDAY NIGHT AS THE LOW
PUSHES SOUTH. LOW TEMPS MONDAY NIGHT WILL DROP TO AROUND 60...
WITH CLEAR SKIES HELPING THE COOLING ALONG.
EXTENDED...TUESDAY THROUGH FRIDAY...
HIGH PRESSURE OVER THE NORTHERN GREAT LAKES EXPANDS SOUTHWARD
DOMINATING THE PATTERN THROUGH THE EXTENDED. A WEAK SHORTWAVE
WEAKENS AS IT APPROACHES NW IL TUESDAY...BUT KEPT TUESDAY DRY.
DRY WEATHER SETTLES IN THROUGH AT LEAST FRIDAY. THE RIDGE BEGINS
TO FLATTEN AND THE ZONAL FLOW ALLOWS A SHORTWAVE TROUGH AND
SURFACE LOW TO MOVE NORTH OF THE CWA BRINGING SHOWERS AND TS TO
THE REGION FRIDAY. FOR TEMPS...TEMPS WARM UNDER THE RIDGE TO NEAR
NORMAL BY THURSDAY AND PERHAPS INTO THE MID TO UPPER 80S BY THE
END OF THE WEEK.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* WEAK LAKE BREEZE MAY REACH MDW AND ORD BY 00Z AND TURN SFC
WINDS TO LIGHT SOUTHEASTERLY.
* TIMING...MAGNITUDE...DURATION OF TSRA THIS EVENING.
TRS
//DISCUSSION...UPDATED 18Z...
CONFIDENCE IN CONVECTIVE TRENDS TODAY AND THIS EVENING IS
INCREASING SOMEWHAT...WITH THE BASIC IDEA SIMILAR TO WHAT WAS
ALREADY BEING CONVEYED IN EARLIER FCST PRODUCTS. FACTORS THAT
WERE RESPONSIBLE FOR LAST NIGHTS CONVECTION OVER THE IA/MO/IL
INTERSECTION ARE DEPICTED TO OCCUR AGAIN TONIGHT...AND WITH
GREATER INTENSITY...ACROSS NORTHEAST ILLINOIS.
THE THOUGHT IS THAT EXISTING ACTIVITY TO THE SOUTHWEST OF THE
AREA...FROM MLI TO SPI...WILL ERODE FROM NORTH TO SOUTH AS IT
SLIDES EAST OR SOUTHEAST AND STAYS OUT OF THE LOCAL AREA.
ACTIVITY OVER NORTHERN IOWA ALSO IS BEGINNING TO FADE. NEW
ACTIVITY IS EXPECTED TO DEVELOP IN THE MOIST AND DESTABILIZING
AIR OVER SOUTH CENTRAL IOWA AND EVEN MORE SO ACROSS NORTHERN
MISSOURI. THIS NEW DEVELOPMENT WOULD WORK INTO THE CHICAGO
TERMINALS TOWARD THE END OF THE EVENING RUSH...SOMEWHERE IN THE
02Z TIME-FRAME.
OVERNIGHT THE FOCUS FOR THIS CONVECTION IS DEPICTED TO PUSH
THROUGH THE TERMINALS OVER A 2-3 HOUR PERIOD AND THEN EVENTUALLY
DROP SOUTH BY MORNING.
LENNING
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* MEDIUM CONFIDENCE TIMING OF TSRA.
* MEDIUM CONFIDENCE IN VISIBILITY DURING TSRA.
* MEDIUM CONFIDENCE IN LINGERING SHRA DURING LATE OVERNIGHT TO
DUSK.
* LOW CONFIDENCE IN WINDS LATE THIS AFTERNOON-EARLY THIS EVENING
AS WEAK LAKE BREEZE PROGGED TO PAST W OF TERMINALS MAY ACTUALLY
NOT NOT QUITE REACH AIR FIELDS.
* LOW CONFIDENCE IN WINDS LATER EVENING AS WEAK SYNOPTIC SCALE
FLOW COULD BE OVERWHELMED BY CONVECTIVE OUTFLOWS.
* HIGH CONFIDENCE IN WINDS VEERING TO W AND NW DURING THE
OVERNIGHT AND SUNDAY.
TRS
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR.
MONDAY...CHANCE OF PM TSRA...OTHERWISE VFR.
TUESDAY THROUGH THURSDAY...VFR.
FRIDAY...CHANCE OF SHRA/TSRA.
IZZI
&&
.MARINE...
404 PM CDT
LARGE HIGH PRESSURE OVER THE EASTERN UNITED STATES WILL SLOWLY
CONTINUE EAST WHILE A TROUGH OF LOW PRESSURE AND FRONTAL BOUNDARY
OVER THE UPPER MISSISSIPPI VALLEY SHIFT EAST ACROSS THE LAKE
TONIGHT. WITH THIS IN PLACE...EXPECT GENERALLY SOUTHERLY FLOW TO
SPAN THE LAKE BEFORE WINDS TURN MORE TO THE SOUTHWEST OVERNIGHT.
WEAK HIGH PRESSURE WILL THEN BUILD EAST ACROSS THE SOUTHERN GREAT
LAKES ON SUNDAY...WITH A TROUGH OF LOW PRESSURE EXTENDING FROM
SOUTHERN QUEBEC WEST TO SOUTHERN ONTARIO. THIS TROUGH OF LOW
PRESSURE WILL SLOWLY SHIFT SOUTH DOWN THE LAKE SUNDAY NIGHT INTO
MONDAY. WESTERLY WINDS WILL TURN TO THE NORTHWEST AND NORTH AS
THIS TROUGH AND ASSOCIATED BOUNDARY WORK DOWN THE LAKE. WINDS AND
WAVES WILL INCREASE BEHIND THIS TROUGH/BOUNDARY...BUT STILL
REMAINING AT 10 TO 20 KT. HIGH PRESSURE WILL THEN MOVE SOUTHEAST
FROM THE CANADIAN PRAIRIES INTO THE GREAT LAKES BEHIND THIS FRONT
BY MIDWEEK.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
405 PM CDT SAT JUN 15 2013
.MESOSCALE DISCUSSION...
CONTINUING TO MONITOR CONVECTIVE TRENDS EARLY THIS AFTERNOON.
STILL PLENTY OF UNCERTAINTY REGARDING EXTENT OF SEVERE THREAT BUT
CURRENT SATELLITE AND SURFACE OBS AND MESOANALYSIS GIVE SOME HINT
AT HOW THINGS MIGHT PLAY OUT. MCV ASSOCIATED WITH LATE MORNING
COMPLEX CURRENTLY PIVOTING SOUTHEAST FROM EASTERN CWA...WITH
BREAKS IN CLOUDS DEVELOPING ON BACK SIDE OF MCV. EASTERN HALF OF
CWA IS QUITE STABLE INITIALLY...BUT RECOVERY OF DEWPOINTS INTO MID
AND UPPER 60S INTO WEST AND SOUTHWEST CWA...ALONG WITH
TEMPERATURES ALREADY WARMING INTO UPPER 70S TO AROUND 80 HAS
RENEWED DESTABILIZATION PROCESS FOR THESE AREAS. RAP IS MOST
BULLISH/LIKELY TOO BULLISH ON MLCAPE VALUES BY LATE
AFTERNOON...BUT EVEN NAM SUPPORTS MLCAPES OF ABOUT 1000-1500 J/KG
BY LATE AFTERNOON OVER THE WESTERN CWA...WITH MINIMAL TO NO
CAPPING BY THEN AND ONLY MINIMAL CAPPING RETURNING BY EARLY
EVENING.
EXPECT THE COMPLEX OVER WEST CENTRAL ILLINOIS TO BE STEERED SOUTH OF
THE CWA...WITH THE LIKELY FOCUS FOR ROBUST DEVELOPMENT IN THE
LATE AFTERNOON INTO THE EVENING TO BE THE WAVE NOTED ON W/V AND
RADAR OVER NORTH CENTRAL IOWA. HI RES MODELS SUCH AS SPC-WRF NMM
AND HRRR SEEM TO HAVE A DECENT HANDLE ON TRENDS AND SHOW CLUSTER
OR CLUSTERS DEVELOPING SOUTH OF THE CURRENTLY WEAKENING
CONVECTION OVER NORTH CENTRAL IOWA OVER EASTERN IOWA AND NORTHERN
MO. THESE THEN FOLLOW THE 850-300 MB THICKNESS LINES EAST OR
EAST-SOUTHEAST FROM WESTERN ILLINOIS BY THE LATE AFTERNOON AND
EARLY EVENING (23Z-01Z) TO NORTHEAST IL AND NORTHWEST INDIANA A
FEW HOURS LATER (02-04Z).
0-6 KM BULK SHEAR STRENGTHENING TO 40 TO AS MUCH AS 50 KT BY EARLY
EVENING WILL SUPPORT ORGANIZATION...AND INCREASING LOW LEVEL JET/0-3
KM SHEAR COULD RESULT IN DAMAGING WIND THREAT. ALSO...MID LEVEL
LAPSE RATES STEEPENING FROM THE WEST WITH APPROACH OF WAVE COULD
PRESENT A SEVERE HAIL THREAT...MAINLY FOR NORTH CENTRAL IL AND
POINTS WEST. THINK THAT COMPLEX WILL BE ON WEAKENING TREND AS IT
HEADS EAST INTO NORTHEAST IL AND NW INDIANA DUE TO LOWER AND
DIMINISHING INSTABILITY BY THAT TIME...BUT STILL CAN FORESEE
LIGHTNING AND GUSTY WINDS AFFECTING OUTDOOR EVENTS OVER THESE AREAS.
IN ADDITION...MORE INTENSE STORMS TODAY OVER REGION HAVE PRODUCED
VERY HEAVY RAINFALL WITH PWAT OVER 1.5 INCHES AND WITH 850 MB
MOISTURE TRANSPORT INCREASING THIS EVENING...IMPRESSIVE RAINFALL
RATES AND LOCALIZED FLASH FLOODING ARE CERTAINLY POSSIBLE.
FINALLY...SOME CONCERN THAT THE INCREASING 850 MB MOISTURE TRANSPORT
AND FLOW COULD ALSO MAINTAIN SEVERE THREAT FARTHER EAST THAN
CURRENTLY EXPECTED...SO WILL CONTINUE TO MONITOR THIS POSSIBILITY
AS WELL. THIS IS SOMETHING THAT THE LATEST 17Z HRRR SHOWS.
RC
&&
.DISCUSSION...
306 PM CDT
THIS EVENING AND TONIGHT...
FOR A SPECIFIC DISCUSSION OF THE FORECAST THROUGH EARLY THIS EVENING
SEE THE MESOSCALE DISCUSSION ABOVE.
THE WEAKENING LINE OF STORMS WILL CONTINUE TO MOVE ESE THROUGH THE
EVENING AND OVERNIGHT. HEAVY RAIN AND LIGHTNING WILL BE THE PRIMARY
THREATS LATER THIS EVENING WITH GUSTY WINDS PSBL. FLASH FLOODING
WILL ALSO NOT BE OUTSIDE OF THE REALM OF POSSIBILITY.
DESPITE THE LINE OF SHOWERS AND STORMS MOVING THROUGH...STILL
LOOKING LIKE A SOUPY NIGHT WITH TEMPS IN THE MID TO UPPER 60S AND
DEWPOINTS ABOUT THE SAME. PUT AREAS OF FOG IN THE FORECAST BEHIND
THE RAIN...BUT NOT EXPECTING WIDESPREAD FOG DEVELOPMENT.
SUNDAY AND MONDAY...
THE CLOSED UPPER LEVEL LOW CURRENTLY OVER SASKATCHEWAN WEAKENS AND
MOVES INTO NORTH DAKOTA SUNDAY EVENING. IT THEN BECOMES ABSORBED BY
A STRONGER TROUGH OVER JAMES BAY SUNDAY NIGHT...AND THE TROUGH AXIS
PASSES OVERHEAD MONDAY NIGHT. AT THE SURFACE...THE LOW ALSO OVER
SASKATCHEWAN EXPANDS OVER THE GREAT LAKES AND THEN CONTINUES
EASTWARD MOVING OVER NEW ENGLAND BY LATE SUNDAY NIGHT.
THINKING THERE MAY BE A FEW LINGERING SHOWERS...SO HAVE SLIGHT
CHANCE TO CHANCE POPS FOR AREAS SOUTH OF A GARY TO STREATOR LINE.
THE SHOWERS SHOULD EXIT TO THE SOUTHEAST DURING THE DAY AS THE
SHORTWAVE SHIFTS EAST. THEN EXPECTING SHOWERS AND THUNDERSTORMS TO
FORM OVER THE NORTH END OF LAKE MICHIGAN SUNDAY AFTN/EVENING AS THE
LOW EXPANDS. THINKING SHOWERS AND STORMS WILL NOT REACH NORTHERN
IL/IN UNTIL MONDAY. HAVE CHANCE POPS BEGINNING MONDAY MORNING...BUT
CONFIDENCE IS LOW IN EXACT TIMING. THINKING SHOWERS AND TS COULD
POSSIBLY BE A BIT DELAYED AND NOT ARRIVE UNTIL THE MORNING/EARLY
AFTN. THE SYSTEM KEEPS PUSHING SOUTH WITH SHOWERS AND STORMS SOUTH
OF THE CWA LATE MONDAY NIGHT. PWATS WILL BE AROUND AN INCH
THROUGHOUT THE EVENT SO A DECENT SOAKING RAIN IS VERY POSSIBLE...BUT
HEAVY RAIN LIKE WE HAVE EXPERIENCED WITH THE PAST FEW SYSTEMS IS NOT
LIKELY.
FOR TEMPS...DID NOT MAKE TOO MANY ADJUSTMENTS TO THE PREVIOUS HIGH
TEMPS FOR SUNDAY. NOT SURE HOW QUICKLY THE SKIES WILL CLEAR
TOMORROW WITH HIGHER TEMPS EXPECTED IF WE CLEAR QUICKER THAN
INDICATED. LOW TO MID 80S ARE EXPECTED AT LEAST...WITH OVERNIGHT
LOWS IN THE 60S. LOWS WILL BE WARMER DOWNTOWN AND SOUTH OF I-80.
HIGH TEMPS ON MONDAY WILL GET INTO THE LOW TO MID 80S AGAIN BUT
EXPECTING A SIGNIFICANT COOLING TREND MONDAY NIGHT AS THE LOW PUSHES
SOUTH. LOW TEMPS MONDAY NIGHT WILL DROP TO AROUND 60...WITH CLEAR
SKIES HELPING THE COOLING ALONG.
EXTENDED...TUESDAY THROUGH FRIDAY...
HIGH PRESSURE OVER THE NORTHERN GREAT LAKES EXPANDS SOUTHWARD
DOMINATING THE PATTERN THROUGH THE EXTENDED. A WEAK SHORTWAVE
WEAKENS AS IT APPROACHES NW IL TUESDAY...BUT KEPT TUESDAY DRY. DRY
WEATHER SETTLES IN THROUGH AT LEAST FRIDAY. THE RIDGE BEGINS TO
FLATTEN AND THE ZONAL FLOW ALLOWS A SHORTWAVE TROUGH AND SURFACE LOW
TO MOVE NORTH OF THE CWA BRINGING SHOWERS AND TS TO THE REGION
FRIDAY. FOR TEMPS...TEMPS WARM UNDER THE RIDGE TO NEAR NORMAL BY
THURSDAY AND PERHAPS INTO THE MID TO UPPER 80S BY THE END OF THE
WEEK.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* TIMING...MAGNITUDE...AND DURATION OF TSRA THIS EVENING.
* POSSIBLE LAKE BREEZE PASSAGE THIS AFTERNOON.
LENNING
//DISCUSSION...UPDATED 18Z...
CONFIDENCE IN CONVECTIVE TRENDS TODAY AND THIS EVENING IS
INCREASING SOMEWHAT...WITH THE BASIC IDEA SIMILAR TO WHAT WAS
ALREADY BEING CONVEYED IN EARLIER FCST PRODUCTS. FACTORS THAT WERE
RESPONSIBLE FOR LAST NIGHTS CONVECTION OVER THE IA/MO/IL
INTERSECTION ARE DEPICTED TO OCCUR AGAIN TONIGHT...AND WITH
GREATER INTENSITY...ACROSS NORTHEAST ILLINOIS.
THE THOUGHT IS THAT EXISTING ACTIVITY TO THE SOUTHWEST OF THE
AREA...FROM MLI TO SPI...WILL ERODE FROM NORTH TO SOUTH AS IT
SLIDES EAST OR SOUTHEAST AND STAYS OUT OF THE LOCAL AREA. ACTIVITY
OVER NORTHERN IOWA ALSO IS BEGINNING TO FADE. NEW ACTIVITY IS
EXPECTED TO DEVELOP IN THE MOIST AND DESTABILIZING AIR OVER SOUTH
CENTRAL IOWA AND EVEN MORE SO ACROSS NORTHERN MISSOURI. THIS NEW
DEVELOPMENT WOULD WORK INTO THE CHICAGO TERMINALS TOWARD THE END
OF THE EVENING RUSH...SOMEWHERE IN THE 02Z TIMEFRAME.
OVERNIGHT THE FOCUS FOR THIS CONVECTION IS DEPICTED TO PUSH
THROUGH THE TERMINALS OVER A 2-3 HOUR PERIOD AND THEN EVENTUALLY DROP
SOUTH BY MORNING.
LENNING
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM CONFIDENCE ON TIMING OF CONVECTION. COULD ARRIVE AN
HOUR...POSSIBLY TWO HOURS...EARLIER THAN DEPICTED IN TAFS. LOWER
CONFIDENCE IN MAGNITUDE OF WINDS AND REDUCED VSBYS.
* MEDIUM TO HIGH CONFIDENCE THAT OVERNIGHT CONVECTION WILL PUSH
WELL SOUTH OF TERMINALS BY MORNING.
* LOW CONFIDENCE IN WHETHER LAKE BREEZE MIGHT PASS THIS
AFTERNOON...AND WHEN THAT MIGHT OCCUR. ELECTED TO LEAVE OUT OF
TAFS FOR NOW.
LENNING
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR.
MONDAY...CHANCE OF PM TSRA...OTHERWISE VFR.
TUESDAY THROUGH THURSDAY...VFR.
FRIDAY...CHANCE OF SHRA/TSRA.
IZZI
&&
.MARINE...
404 PM CDT
LARGE HIGH PRESSURE OVER THE EASTERN UNITED STATES WILL SLOWLY
CONTINUE EAST WHILE A TROUGH OF LOW PRESSURE AND FRONTAL BOUNDARY
OVER THE UPPER MISSISSIPPI VALLEY SHIFT EAST ACROSS THE LAKE
TONIGHT. WITH THIS IN PLACE...EXPECT GENERALLY SOUTHERLY FLOW TO
SPAN THE LAKE BEFORE WINDS TURN MORE TO THE SOUTHWEST OVERNIGHT.
WEAK HIGH PRESSURE WILL THEN BUILD EAST ACROSS THE SOUTHERN GREAT
LAKES ON SUNDAY...WITH A TROUGH OF LOW PRESSURE EXTENDING FROM
SOUTHERN QUEBEC WEST TO SOUTHERN ONTARIO. THIS TROUGH OF LOW
PRESSURE WILL SLOWLY SHIFT SOUTH DOWN THE LAKE SUNDAY NIGHT INTO
MONDAY. WESTERLY WINDS WILL TURN TO THE NORTHWEST AND NORTH AS
THIS TROUGH AND ASSOCIATED BOUNDARY WORK DOWN THE LAKE. WINDS AND
WAVES WILL INCREASE BEHIND THIS TROUGH/BOUNDARY...BUT STILL
REMAINING AT 10 TO 20 KT. HIGH PRESSURE WILL THEN MOVE SOUTHEAST
FROM THE CANADIAN PRAIRIES INTO THE GREAT LAKES BEHIND THIS FRONT
BY MIDWEEK.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
317 PM CDT SAT JUN 15 2013
.MESOSCALE DISCUSSION...
CONTINUING TO MONITOR CONVECTIVE TRENDS EARLY THIS AFTERNOON.
STILL PLENTY OF UNCERTAINTY REGARDING EXTENT OF SEVERE THREAT BUT
CURRENT SATELLITE AND SURFACE OBS AND MESOANALYSIS GIVE SOME HINT
AT HOW THINGS MIGHT PLAY OUT. MCV ASSOCIATED WITH LATE MORNING
COMPLEX CURRENTLY PIVOTING SOUTHEAST FROM EASTERN CWA...WITH
BREAKS IN CLOUDS DEVELOPING ON BACK SIDE OF MCV. EASTERN HALF OF
CWA IS QUITE STABLE INITIALLY...BUT RECOVERY OF DEWPOINTS INTO MID
AND UPPER 60S INTO WEST AND SOUTHWEST CWA...ALONG WITH
TEMPERATURES ALREADY WARMING INTO UPPER 70S TO AROUND 80 HAS
RENEWED DESTABILIZATION PROCESS FOR THESE AREAS. RAP IS MOST
BULLISH/LIKELY TOO BULLISH ON MLCAPE VALUES BY LATE
AFTERNOON...BUT EVEN NAM SUPPORTS MLCAPES OF ABOUT 1000-1500 J/KG
BY LATE AFTERNOON OVER THE WESTERN CWA...WITH MINIMAL TO NO
CAPPING BY THEN AND ONLY MINIMAL CAPPING RETURNING BY EARLY
EVENING.
EXPECT THE COMPLEX OVER WEST CENTRAL ILLINOIS TO BE STEERED SOUTH OF
THE CWA...WITH THE LIKELY FOCUS FOR ROBUST DEVELOPMENT IN THE
LATE AFTERNOON INTO THE EVENING TO BE THE WAVE NOTED ON W/V AND
RADAR OVER NORTH CENTRAL IOWA. HI RES MODELS SUCH AS SPC-WRF NMM
AND HRRR SEEM TO HAVE A DECENT HANDLE ON TRENDS AND SHOW CLUSTER
OR CLUSTERS DEVELOPING SOUTH OF THE CURRENTLY WEAKENING
CONVECTION OVER NORTH CENTRAL IOWA OVER EASTERN IOWA AND NORTHERN
MO. THESE THEN FOLLOW THE 850-300 MB THICKNESS LINES EAST OR
EAST-SOUTHEAST FROM WESTERN ILLINOIS BY THE LATE AFTERNOON AND
EARLY EVENING (23Z-01Z) TO NORTHEAST IL AND NORTHWEST INDIANA A
FEW HOURS LATER (02-04Z).
0-6 KM BULK SHEAR STRENGTHENING TO 40 TO AS MUCH AS 50 KT BY EARLY
EVENING WILL SUPPORT ORGANIZATION...AND INCREASING LOW LEVEL JET/0-3
KM SHEAR COULD RESULT IN DAMAGING WIND THREAT. ALSO...MID LEVEL
LAPSE RATES STEEPENING FROM THE WEST WITH APPROACH OF WAVE COULD
PRESENT A SEVERE HAIL THREAT...MAINLY FOR NORTH CENTRAL IL AND
POINTS WEST. THINK THAT COMPLEX WILL BE ON WEAKENING TREND AS IT
HEADS EAST INTO NORTHEAST IL AND NW INDIANA DUE TO LOWER AND
DIMINISHING INSTABILITY BY THAT TIME...BUT STILL CAN FORESEE
LIGHTNING AND GUSTY WINDS AFFECTING OUTDOOR EVENTS OVER THESE AREAS.
IN ADDITION...MORE INTENSE STORMS TODAY OVER REGION HAVE PRODUCED
VERY HEAVY RAINFALL WITH PWAT OVER 1.5 INCHES AND WITH 850 MB
MOISTURE TRANSPORT INCREASING THIS EVENING...IMPRESSIVE RAINFALL
RATES AND LOCALIZED FLASH FLOODING ARE CERTAINLY POSSIBLE.
FINALLY...SOME CONCERN THAT THE INCREASING 850 MB MOISTURE TRANSPORT
AND FLOW COULD ALSO MAINTAIN SEVERE THREAT FARTHER EAST THAN
CURRENTLY EXPECTED...SO WILL CONTINUE TO MONITOR THIS POSSIBILITY
AS WELL. THIS IS SOMETHING THAT THE LATEST 17Z HRRR SHOWS.
RC
&&
.DISCUSSION...
306 PM CDT
THIS EVENING AND TONIGHT...
FOR A SPECIFIC DISCUSSION OF THE FORECAST THROUGH EARLY THIS EVENING
SEE THE MESOSCALE DISCUSSION ABOVE.
THE WEAKENING LINE OF STORMS WILL CONTINUE TO MOVE ESE THROUGH THE
EVENING AND OVERNIGHT. HEAVY RAIN AND LIGHTNING WILL BE THE PRIMARY
THREATS LATER THIS EVENING WITH GUSTY WINDS PSBL. FLASH FLOODING
WILL ALSO NOT BE OUTSIDE OF THE REALM OF POSSIBILITY.
DESPITE THE LINE OF SHOWERS AND STORMS MOVING THROUGH...STILL
LOOKING LIKE A SOUPY NIGHT WITH TEMPS IN THE MID TO UPPER 60S AND
DEWPOINTS ABOUT THE SAME. PUT AREAS OF FOG IN THE FORECAST BEHIND
THE RAIN...BUT NOT EXPECTING WIDESPREAD FOG DEVELOPMENT.
SUNDAY AND MONDAY...
THE CLOSED UPPER LEVEL LOW CURRENTLY OVER SASKATCHEWAN WEAKENS AND
MOVES INTO NORTH DAKOTA SUNDAY EVENING. IT THEN BECOMES ABSORBED BY
A STRONGER TROUGH OVER JAMES BAY SUNDAY NIGHT...AND THE TROUGH AXIS
PASSES OVERHEAD MONDAY NIGHT. AT THE SURFACE...THE LOW ALSO OVER
SASKATCHEWAN EXPANDS OVER THE GREAT LAKES AND THEN CONTINUES
EASTWARD MOVING OVER NEW ENGLAND BY LATE SUNDAY NIGHT.
THINKING THERE MAY BE A FEW LINGERING SHOWERS...SO HAVE SLIGHT
CHANCE TO CHANCE POPS FOR AREAS SOUTH OF A GARY TO STREATOR LINE.
THE SHOWERS SHOULD EXIT TO THE SOUTHEAST DURING THE DAY AS THE
SHORTWAVE SHIFTS EAST. THEN EXPECTING SHOWERS AND THUNDERSTORMS TO
FORM OVER THE NORTH END OF LAKE MICHIGAN SUNDAY AFTN/EVENING AS THE
LOW EXPANDS. THINKING SHOWERS AND STORMS WILL NOT REACH NORTHERN
IL/IN UNTIL MONDAY. HAVE CHANCE POPS BEGINNING MONDAY MORNING...BUT
CONFIDENCE IS LOW IN EXACT TIMING. THINKING SHOWERS AND TS COULD
POSSIBLY BE A BIT DELAYED AND NOT ARRIVE UNTIL THE MORNING/EARLY
AFTN. THE SYSTEM KEEPS PUSHING SOUTH WITH SHOWERS AND STORMS SOUTH
OF THE CWA LATE MONDAY NIGHT. PWATS WILL BE AROUND AN INCH
THROUGHOUT THE EVENT SO A DECENT SOAKING RAIN IS VERY POSSIBLE...BUT
HEAVY RAIN LIKE WE HAVE EXPERIENCED WITH THE PAST FEW SYSTEMS IS NOT
LIKELY.
FOR TEMPS...DID NOT MAKE TOO MANY ADJUSTMENTS TO THE PREVIOUS HIGH
TEMPS FOR SUNDAY. NOT SURE HOW QUICKLY THE SKIES WILL CLEAR
TOMORROW WITH HIGHER TEMPS EXPECTED IF WE CLEAR QUICKER THAN
INDICATED. LOW TO MID 80S ARE EXPECTED AT LEAST...WITH OVERNIGHT
LOWS IN THE 60S. LOWS WILL BE WARMER DOWNTOWN AND SOUTH OF I-80.
HIGH TEMPS ON MONDAY WILL GET INTO THE LOW TO MID 80S AGAIN BUT
EXPECTING A SIGNIFICANT COOLING TREND MONDAY NIGHT AS THE LOW PUSHES
SOUTH. LOW TEMPS MONDAY NIGHT WILL DROP TO AROUND 60...WITH CLEAR
SKIES HELPING THE COOLING ALONG.
EXTENDED...TUESDAY THROUGH FRIDAY...
HIGH PRESSURE OVER THE NORTHERN GREAT LAKES EXPANDS SOUTHWARD
DOMINATING THE PATTERN THROUGH THE EXTENDED. A WEAK SHORTWAVE
WEAKENS AS IT APPROACHES NW IL TUESDAY...BUT KEPT TUESDAY DRY. DRY
WEATHER SETTLES IN THROUGH AT LEAST FRIDAY. THE RIDGE BEGINS TO
FLATTEN AND THE ZONAL FLOW ALLOWS A SHORTWAVE TROUGH AND SURFACE LOW
TO MOVE NORTH OF THE CWA BRINGING SHOWERS AND TS TO THE REGION
FRIDAY. FOR TEMPS...TEMPS WARM UNDER THE RIDGE TO NEAR NORMAL BY
THURSDAY AND PERHAPS INTO THE MID TO UPPER 80S BY THE END OF THE
WEEK.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* TIMING...MAGNITUDE...AND DURATION OF TSRA THIS EVENING.
* POSSIBLE LAKE BREEZE PASSAGE THIS AFTERNOON.
LENNING
//DISCUSSION...UPDATED 18Z...
CONFIDENCE IN CONVECTIVE TRENDS TODAY AND THIS EVENING IS
INCREASING SOMEWHAT...WITH THE BASIC IDEA SIMILAR TO WHAT WAS
ALREADY BEING CONVEYED IN EARLIER FCST PRODUCTS. FACTORS THAT WERE
RESPONSIBLE FOR LAST NIGHTS CONVECTION OVER THE IA/MO/IL
INTERSECTION ARE DEPICTED TO OCCUR AGAIN TONIGHT...AND WITH
GREATER INTENSITY...ACROSS NORTHEAST ILLINOIS.
THE THOUGHT IS THAT EXISTING ACTIVITY TO THE SOUTHWEST OF THE
AREA...FROM MLI TO SPI...WILL ERODE FROM NORTH TO SOUTH AS IT
SLIDES EAST OR SOUTHEAST AND STAYS OUT OF THE LOCAL AREA. ACTIVITY
OVER NORTHERN IOWA ALSO IS BEGINNING TO FADE. NEW ACTIVITY IS
EXPECTED TO DEVELOP IN THE MOIST AND DESTABILIZING AIR OVER SOUTH
CENTRAL IOWA AND EVEN MORE SO ACROSS NORTHERN MISSOURI. THIS NEW
DEVELOPMENT WOULD WORK INTO THE CHICAGO TERMINALS TOWARD THE END
OF THE EVENING RUSH...SOMEWHERE IN THE 02Z TIMEFRAME.
OVERNIGHT THE FOCUS FOR THIS CONVECTION IS DEPICTED TO PUSH
THROUGH THE TERMINALS OVER A 2-3 HOUR PERIOD AND THEN EVENTUALLY DROP
SOUTH BY MORNING.
LENNING
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM CONFIDENCE ON TIMING OF CONVECTION. COULD ARRIVE AN
HOUR...POSSIBLY TWO HOURS...EARLIER THAN DEPICTED IN TAFS. LOWER
CONFIDENCE IN MAGNITUDE OF WINDS AND REDUCED VSBYS.
* MEDIUM TO HIGH CONFIDENCE THAT OVERNIGHT CONVECTION WILL PUSH
WELL SOUTH OF TERMINALS BY MORNING.
* LOW CONFIDENCE IN WHETHER LAKE BREEZE MIGHT PASS THIS
AFTERNOON...AND WHEN THAT MIGHT OCCUR. ELECTED TO LEAVE OUT OF
TAFS FOR NOW.
LENNING
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR.
MONDAY...CHANCE OF PM TSRA...OTHERWISE VFR.
TUESDAY THROUGH THURSDAY...VFR.
FRIDAY...CHANCE OF SHRA/TSRA.
IZZI
&&
.MARINE...
229 AM CDT
OUTSIDE OF THUNDERSTORM CHANCES...GENERALLY QUIET WEATHER ON THE
LAKE THROUGH THE WEEKEND WITH SOUTHERLY WINDS DEVELOPING. A COUPLE
OF COLD FRONT WILL MOVE ACROSS THE LAKE...FIRST ONE THIS WEEKEND
WITH WIND SHIFT TO WEST WITH THE SECONDARY...MORE ROBUST...FRONT
MOVING DOWN THE LAKE MONDAY INTO MONDAY NIGHT. COULD SEE A PERIOD
OF SOMEWHAT STRONGER NORTHERLY FLOW WITH THE COLD AIR ADVECTION
MONDAY NIGHT INTO TUESDAY...BUT STILL ONLY LOOKING AT A PERIOD OF
FORCE 3 WINDS FOR THE SOUTHERN PORTIONS OF THE LAKE AS A WORST
CASE SCENARIO. HIGH PRESSURE BUILDS BACK INTO THE REGION WITH
QUIET CONDITIONS AGAIN BY MID WEEK.
IZZI
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
307 PM CDT SAT JUN 15 2013
.MESOSCALE DISCUSSION...215 PM CDT
CONTINUING TO MONITOR CONVECTIVE TRENDS EARLY THIS AFTERNOON. STILL
PLENTY OF UNCERTAINTY REGARDING EXTENT OF SEVERE THREAT BUT CURRENT
SATELLITE AND SURFACE OBS AND MESOANALYSIS GIVE SOME HINT AT HOW
THINGS MIGHT PLAY OUT. MCV ASSOCIATED WITH LATE MORNING COMPLEX
CURRENTLY PIVOTING SOUTHEAST FROM EASTERN CWA...WITH BREAKS IN
CLOUDS DEVELOPING ON BACK SIDE OF MCV. EASTERN HALF OF CWA IS QUITE
STABLE INITIALLY...BUT RECOVERY OF DEWPOINTS INTO MID AND UPPER 60S
INTO WEST AND SOUTHWEST CWA...ALONG WITH TEMPERATURES ALREADY
WARMING INTO UPPER 70S TO AROUND 80 HAS RENEWED DESTABILIZATION
PROCESS FOR THESE AREAS. RAP IS MOST BULLISH/LIKELY TOO BULLISH ON
MLCAPE VALUES BY LATE AFTERNOON...BUT EVEN NAM SUPPORTS MLCAPES OF
ABOUT 1000-1500 J/KG BY LATE AFTERNOON OVER THE WESTERN CWA...WITH
MINIMAL TO NO CAPPING BY THEN AND ONLY MINIMAL CAPPING RETURNING BY
EARLY EVENING.
EXPECT THE COMPLEX OVER WEST CENTRAL ILLINOIS TO BE STEERED SOUTH OF
THE CWA...WITH THE LIKELY FOCUS FOR ROBUST DEVELOPMENT IN THE
LATE AFTERNOON INTO THE EVENING TO BE THE WAVE NOTED ON W/V AND
RADAR OVER NORTH CENTRAL IOWA. HI RES MODELS SUCH AS SPC-WRF NMM
AND HRRR SEEM TO HAVE A DECENT HANDLE ON TRENDS AND SHOW CLUSTER
OR CLUSTERS DEVELOPING SOUTH OF THE CURRENTLY WEAKENING
CONVECTION OVER NORTH CENTRAL IOWA OVER EASTERN IOWA AND NORTHERN
MO. THESE THEN FOLLOW THE 850-300 MB THICKNESS LINES EAST OR
EAST-SOUTHEAST FROM WESTERN ILLINOIS BY THE LATE AFTERNOON AND
EARLY EVENING (23Z-01Z) TO NORTHEAST IL AND NORTHWEST INDIANA A
FEW HOURS LATER (02-04Z).
0-6 KM BULK SHEAR STRENGTHENING TO 40 TO AS MUCH AS 50 KT BY EARLY
EVENING WILL SUPPORT ORGANIZATION...AND INCREASING LOW LEVEL JET/0-3
KM SHEAR COULD RESULT IN DAMAGING WIND THREAT. ALSO...MID LEVEL
LAPSE RATES STEEPENING FROM THE WEST WITH APPROACH OF WAVE COULD
PRESENT A SEVERE HAIL THREAT...MAINLY FOR NORTH CENTRAL IL AND
POINTS WEST. THINK THAT COMPLEX WILL BE ON WEAKENING TREND AS IT
HEADS EAST INTO NORTHEAST IL AND NW INDIANA DUE TO LOWER AND
DIMINISHING INSTABILITY BY THAT TIME...BUT STILL CAN FORESEE
LIGHTNING AND GUSTY WINDS AFFECTING OUTDOOR EVENTS OVER THESE AREAS.
IN ADDITION...MORE INTENSE STORMS TODAY OVER REGION HAVE PRODUCED
VERY HEAVY RAINFALL WITH PWAT OVER 1.5 INCHES AND WITH 850 MB
MOISTURE TRANSPORT INCREASING THIS EVENING...IMPRESSIVE RAINFALL
RATES AND LOCALIZED FLASH FLOODING ARE CERTAINLY POSSIBLE.
FINALLY...SOME CONCERN THAT THE INCREASING 850 MB MOISTURE TRANSPORT
AND FLOW COULD ALSO MAINTAIN SEVERE THREAT FARTHER EAST THAN
CURRENTLY EXPECTED...SO WILL CONTINUE TO MONITOR THIS POSSIBILITY
AS WELL. THIS IS SOMETHING THAT THE LATEST 17Z HRRR SHOWS.
RC
&&
.DISCUSSION...
306 PM CDT
THIS EVENING AND TONIGHT...
FOR A SPECIFIC DISCUSSION OF THE FORECAST THROUGH EARLY THIS EVENING
SEE THE MESOSCALE DISCUSSION ABOVE.
THE WEAKENING LINE OF STORMS WILL CONTINUE TO MOVE ESE THROUGH THE
EVENING AND OVERNIGHT. HEAVY RAIN AND LIGHTNING WILL BE THE PRIMARY
THREATS LATER THIS EVENING WITH GUSTY WINDS PSBL. FLASH FLOODING
WILL ALSO NOT BE OUTSIDE OF THE REALM OF POSSIBILITY.
DESPITE THE LINE OF SHOWERS AND STORMS MOVING THROUGH...STILL
LOOKING LIKE A SOUPY NIGHT WITH TEMPS IN THE MID TO UPPER 60S AND
DEWPOINTS ABOUT THE SAME. PUT AREAS OF FOG IN THE FORECAST BEHIND
THE RAIN...BUT NOT EXPECTING WIDESPREAD FOG DEVELOPMENT.
SUNDAY AND MONDAY...
THE CLOSED UPPER LEVEL LOW CURRENTLY OVER SASKATCHEWAN WEAKENS AND
MOVES INTO NORTH DAKOTA SUNDAY EVENING. IT THEN BECOMES ABSORBED BY
A STRONGER TROUGH OVER JAMES BAY SUNDAY NIGHT...AND THE TROUGH AXIS
PASSES OVERHEAD MONDAY NIGHT. AT THE SURFACE...THE LOW ALSO OVER
SASKATCHEWAN EXPANDS OVER THE GREAT LAKES AND THEN CONTINUES
EASTWARD MOVING OVER NEW ENGLAND BY LATE SUNDAY NIGHT.
THINKING THERE MAY BE A FEW LINGERING SHOWERS...SO HAVE SLIGHT
CHANCE TO CHANCE POPS FOR AREAS SOUTH OF A GARY TO STREATOR LINE.
THE SHOWERS SHOULD EXIT TO THE SOUTHEAST DURING THE DAY AS THE
SHORTWAVE SHIFTS EAST. THEN EXPECTING SHOWERS AND THUNDERSTORMS TO
FORM OVER THE NORTH END OF LAKE MICHIGAN SUNDAY AFTN/EVENING AS THE
LOW EXPANDS. THINKING SHOWERS AND STORMS WILL NOT REACH NORTHERN
IL/IN UNTIL MONDAY. HAVE CHANCE POPS BEGINNING MONDAY MORNING...BUT
CONFIDENCE IS LOW IN EXACT TIMING. THINKING SHOWERS AND TS COULD
POSSIBLY BE A BIT DELAYED AND NOT ARRIVE UNTIL THE MORNING/EARLY
AFTN. THE SYSTEM KEEPS PUSHING SOUTH WITH SHOWERS AND STORMS SOUTH
OF THE CWA LATE MONDAY NIGHT. PWATS WILL BE AROUND AN INCH
THROUGHOUT THE EVENT SO A DECENT SOAKING RAIN IS VERY POSSIBLE...BUT
HEAVY RAIN LIKE WE HAVE EXPERIENCED WITH THE PAST FEW SYSTEMS IS NOT
LIKELY.
FOR TEMPS...DID NOT MAKE TOO MANY ADJUSTMENTS TO THE PREVIOUS HIGH
TEMPS FOR SUNDAY. NOT SURE HOW QUICKLY THE SKIES WILL CLEAR
TOMORROW WITH HIGHER TEMPS EXPECTED IF WE CLEAR QUICKER THAN
INDICATED. LOW TO MID 80S ARE EXPECTED AT LEAST...WITH OVERNIGHT
LOWS IN THE 60S. LOWS WILL BE WARMER DOWNTOWN AND SOUTH OF I-80.
HIGH TEMPS ON MONDAY WILL GET INTO THE LOW TO MID 80S AGAIN BUT
EXPECTING A SIGNIFICANT COOLING TREND MONDAY NIGHT AS THE LOW PUSHES
SOUTH. LOW TEMPS MONDAY NIGHT WILL DROP TO AROUND 60...WITH CLEAR
SKIES HELPING THE COOLING ALONG.
EXTENDED...TUESDAY THROUGH FRIDAY...
HIGH PRESSURE OVER THE NORTHERN GREAT LAKES EXPANDS SOUTHWARD
DOMINATING THE PATTERN THROUGH THE EXTENDED. A WEAK SHORTWAVE
WEAKENS AS IT APPROACHES NW IL TUESDAY...BUT KEPT TUESDAY DRY. DRY
WEATHER SETTLES IN THROUGH AT LEAST FRIDAY. THE RIDGE BEGINS TO
FLATTEN AND THE ZONAL FLOW ALLOWS A SHORTWAVE TROUGH AND SURFACE LOW
TO MOVE NORTH OF THE CWA BRINGING SHOWERS AND TS TO THE REGION
FRIDAY. FOR TEMPS...TEMPS WARM UNDER THE RIDGE TO NEAR NORMAL BY
THURSDAY AND PERHAPS INTO THE MID TO UPPER 80S BY THE END OF THE
WEEK.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* TIMING...MAGNITUDE...AND DURATION OF TSRA TOWARD EVENING.
LENNING
//DISCUSSION...UPDATED 18Z...
CONFIDENCE IN CONVECTIVE TRENDS TODAY AND THIS EVENING IS
INCREASING SOMEWHAT...WITH THE BASIC IDEA SIMILAR TO WHAT WAS
ALREADY BEING CONVEYED IN EARLIER FCST PRODUCTS. FACTORS THAT WERE
RESPONSIBLE FOR LAST NIGHTS CONVECTION OVER THE IA/MO/IL
INTERSECTION ARE DEPICTED TO OCCUR AGAIN TONIGHT...AND WITH
GREATER INTENSITY...ACROSS NORTHEAST ILLINOIS.
THE THOUGHT IS THAT EXISTING ACTIVITY TO THE SOUTHWEST OF THE
AREA...FROM MLI TO SPI...WILL ERODE FROM NORTH TO SOUTH AS IT
SLIDES EAST OR SOUTHEAST AND STAYS OUT OF THE LOCAL AREA. ACTIVITY
OVER NORTHERN IOWA ALSO IS BEGINNING TO FADE. NEW ACTIVITY IS
EXPECTED TO DEVELOP IN THE MOIST AND DESTABILIZING AIR OVER SOUTH
CENTRAL IOWA AND EVEN MORE SO ACROSS NORTHERN MISSOURI. THIS NEW
DEVELOPMENT WOULD WORK INTO THE CHICAGO TERMINALS TOWARD THE END
OF THE EVENING RUSH...SOMEWHERE IN THE 02Z TIMEFRAME.
OVERNIGHT THE FOCUS FOR THIS CONVECTION IS DEPICTED TO PUSH
THROUGH THE TERMINALS OVER A 2-3 HOUR PERIOD AND THEN EVENTUALLY DROP
SOUTH BY MORNING.
LENNING
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM CONFIDENCE IN TIMING OF CONVECTION INTO THE TERMINALS
THIS EVENING. LOWER CONFIDENCE IN MAGNITUDE OF WINDS AND REDUCED
VSBYS.
* MEDIUM TO HIGH CONFIDENCE THAT OVERNIGHT CONVECTION WILL PUSH
WELL SOUTH OF TERMINALS BY MORNING.
LENNING
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR.
MONDAY...CHANCE OF PM TSRA...OTHERWISE VFR.
TUESDAY THROUGH THURSDAY...VFR.
FRIDAY...CHANCE OF SHRA/TSRA.
IZZI
&&
.MARINE...
229 AM CDT
OUTSIDE OF THUNDERSTORM CHANCES...GENERALLY QUIET WEATHER ON THE
LAKE THROUGH THE WEEKEND WITH SOUTHERLY WINDS DEVELOPING. A COUPLE
OF COLD FRONT WILL MOVE ACROSS THE LAKE...FIRST ONE THIS WEEKEND
WITH WIND SHIFT TO WEST WITH THE SECONDARY...MORE ROBUST...FRONT
MOVING DOWN THE LAKE MONDAY INTO MONDAY NIGHT. COULD SEE A PERIOD
OF SOMEWHAT STRONGER NORTHERLY FLOW WITH THE COLD AIR ADVECTION
MONDAY NIGHT INTO TUESDAY...BUT STILL ONLY LOOKING AT A PERIOD OF
FORCE 3 WINDS FOR THE SOUTHERN PORTIONS OF THE LAKE AS A WORST
CASE SCENARIO. HIGH PRESSURE BUILDS BACK INTO THE REGION WITH
QUIET CONDITIONS AGAIN BY MID WEEK.
IZZI
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
215 PM CDT SAT JUN 15 2013
.MESOSCALE DISCUSSION...
215 PM CDT
CONTINUING TO MONITOR CONVECTIVE TRENDS EARLY THIS AFTERNOON. STILL
PLENTY OF UNCERTAINTY REGARDING EXTENT OF SEVERE THREAT BUT CURRENT
SATELLITE AND SURFACE OBS AND MESOANALYSIS GIVE SOME HINT AT HOW
THINGS MIGHT PLAY OUT. MCV ASSOCIATED WITH LATE MORNING COMPLEX
CURRENTLY PIVOTING SOUTHEAST FROM EASTERN CWA...WITH BREAKS IN
CLOUDS DEVELOPING ON BACK SIDE OF MCV. EASTERN HALF OF CWA IS QUITE
STABLE INITIALLY...BUT RECOVERY OF DEWPOINTS INTO MID AND UPPER 60S
INTO WEST AND SOUTHWEST CWA...ALONG WITH TEMPERATURES ALREADY
WARMING INTO UPPER 70S TO AROUND 80 HAS RENEWED DESTABILIZATION
PROCESS FOR THESE AREAS. RAP IS MOST BULLISH/LIKELY TOO BULLISH ON
MLCAPE VALUES BY LATE AFTERNOON...BUT EVEN NAM SUPPORTS MLCAPES OF
ABOUT 1000-1500 J/KG BY LATE AFTERNOON OVER THE WESTERN CWA...WITH
MINIMAL TO NO CAPPING BY THEN AND ONLY MINIMAL CAPPING RETURNING BY
EARLY EVENING.
EXPECT THE COMPLEX OVER WEST CENTRAL ILLINOIS TO BE STEERED SOUTH OF
THE CWA...WITH THE LIKELY FOCUS FOR ROBUST DEVELOPMENT IN THE
LATE AFTERNOON INTO THE EVENING TO BE THE WAVE NOTED ON W/V AND
RADAR OVER NORTH CENTRAL IOWA. HI RES MODELS SUCH AS SPC-WRF NMM
AND HRRR SEEM TO HAVE A DECENT HANDLE ON TRENDS AND SHOW CLUSTER
OR CLUSTERS DEVELOPING SOUTH OF THE CURRENTLY WEAKENING
CONVECTION OVER NORTH CENTRAL IOWA OVER EASTERN IOWA AND NORTHERN
MO. THESE THEN FOLLOW THE 850-300 MB THICKNESS LINES EAST OR
EAST-SOUTHEAST FROM WESTERN ILLINOIS BY THE LATE AFTERNOON AND
EARLY EVENING (23Z-01Z) TO NORTHEAST IL AND NORTHWEST INDIANA A
FEW HOURS LATER (02-04Z).
0-6 KM BULK SHEAR STRENGTHENING TO 40 TO AS MUCH AS 50 KT BY EARLY
EVENING WILL SUPPORT ORGANIZATION...AND INCREASING LOW LEVEL JET/0-3
KM SHEAR COULD RESULT IN DAMAGING WIND THREAT. ALSO...MID LEVEL
LAPSE RATES STEEPENING FROM THE WEST WITH APPROACH OF WAVE COULD
PRESENT A SEVERE HAIL THREAT...MAINLY FOR NORTH CENTRAL IL AND
POINTS WEST. THINK THAT COMPLEX WILL BE ON WEAKENING TREND AS IT
HEADS EAST INTO NORTHEAST IL AND NW INDIANA DUE TO LOWER AND
DIMINISHING INSTABILITY BY THAT TIME...BUT STILL CAN FORESEE
LIGHTNING AND GUSTY WINDS AFFECTING OUTDOOR EVENTS OVER THESE AREAS.
IN ADDITION...MORE INTENSE STORMS TODAY OVER REGION HAVE PRODUCED
VERY HEAVY RAINFALL WITH PWAT OVER 1.5 INCHES AND WITH 850 MB
MOISTURE TRANSPORT INCREASING THIS EVENING...IMPRESSIVE RAINFALL
RATES AND LOCALIZED FLASH FLOODING ARE CERTAINLY POSSIBLE.
FINALLY...SOME CONCERN THAT THE INCREASING 850 MB MOISTURE TRANSPORT
AND FLOW COULD ALSO MAINTAIN SEVERE THREAT FARTHER EAST THAN
CURRENTLY EXPECTED...SO WILL CONTINUE TO MONITOR THIS POSSIBILITY
AS WELL. THIS IS SOMETHING THAT THE LATEST 17Z HRRR SHOWS.
RC
&&
.DISCUSSION...
1147 AM CDT
VERY COMPLEX FORECAST UNFOLDING THIS AFTERNOON. TWO AREAS OF
CONVECTION ARE TO THE WEST AND SOUTH OF THE REGION WITH ANOTHER
LINE OF STORMS BEGINNING TO TAKE SHAPE FROM CEDAR RAPIDS IA TO
GALESBURG IL. MEANWHILE SHOWERS ARE STILL SLOWLY MAKING THEIR WAY
OUT OF NORTHERN IL AND IN. THE LINGERING STABLE CONDITIONS AND
CLOUD COVER DUE TO THE MORNING SHOWERS IS LIMITING INSTABILITY
OVER NORTHERN IL AND IN. HOWEVER...CONFIDENCE IS INCREASING ON
WHERE CONVECTION WILL OCCUR THIS AFTERNOON AND EVENING. GUIDANCE
AND OBS INDICATE INSTABILITY WILL INCREASE SOUTH OF A ROCKFORD IL
TO HEBRON IL LINE THIS AFTERNOON...WHICH WOULD SUGGEST THAT THE
LINE OF STORMS ACROSS EASTERN IA AND WEST CENTRAL IL WILL CONTINUE
TO MOVE EASTWARD. THINKING THAT LINE WILL BE OUR MAIN SHOW TODAY
WITH STRONG WINDS...HEAVY RAIN...AND FLASH FLOODING BE THE MAIN
CONCERNS.
THINKING THE COMPLEX OVER NORTH CENTRAL IA WILL SHIFT NORTHWARD
AND PASS THROUGH SOUTHERN WI. WILL KEEP SHOWERS AND THUNDERSTORMS
ACROSS THE ENTIRE CWA THIS AFTERNOON AND EVENING REGARDLESS...BUT
STILL THINK THE BEST CHANCE FOR SEVERE CONVECTION WILL BE SOUTH OF
A ROCKFORD IL TO HEBRON IN LINE.
JEE
//PREV DISCUSSION...
309 AM CDT
MAIN FORECAST CONCERNS THIS MORNING WILL BE DEALING WITH SEVERE
WEATHER CHANCES THIS AFTERNOON/EVENING AND HEAVY RAIN POTENTIAL THIS
EVENING AND TONIGHT.
TODAY AND TONIGHT...
EARLY THIS MORNING A CONVECTIVE COMPLEX IS PUSHING SOUTHEAST ACROSS
NORTHERN MISSOURI THOUGH HAS SHOWN SIGNS OF WEAKENING AS IT MOVES
FROM THE BETTER FORCING ASSOCIATED WITH THE LOW LEVEL JET FOCUSED
OVER CENTRAL IOWA. FARTHER NORTH UNORGANIZED AND WEAKER CONVECTION
SHOULD DIMINISH WITH PERHAPS A FEW LINGERING SHOWERS MOVING INTO THE
AREA THIS MORNING. AN MCV OVER SOUTHEASTERN IOWA WILL MOVE ESE
ACROSS CENTRAL ILLINOIS THIS MORNING AND SHOULD SUPPORT THE GREATEST
POPS OVER THE SOUTHERN CWA //LATEST RAP RUN SEEMS TO HANDLE THIS
FEATURE WELL//. HOW QUICKLY THESE SHOWERS CLEAR OUT AND THE
ASSOCIATED CLOUD COVER...INCLUDING THE CIRRUS CANOPY FROM THE MCS TO
THE SOUTHWEST WILL BE KEY TO BEING ABLE TO RECOVER AND SUPPORT
ADDITIONAL SEVERE WEATHER TODAY. DO EXPECT A LULL IN PRECIP LATE
THIS MORNING THROUGH MID AFTERNOON BETWEEN SYSTEMS.
GUIDANCE SUPPORTS AN AXIS OF MODERATE TO STRONG MLCAPE DEVELOPING
FROM KANSAS NORTHEAST INTO NORTHERN WISCONSIN THIS AFTERNOON WITH
NORTH CENTRAL ILLINOIS ON THE EASTERN PERIPHERY OF THE INSTABILITY.
WHILE INITIALLY CAPPED...A COMPACT WAVE MOVING ACROSS IOWA LATE THIS
AFTERNOON AND EARLY EVENING WILL HELP TO WEAKEN THE CAP ALLOWING FOR
STRONGER SURFACE BASED CONVECTION TO DEVELOP OVER IOWA. DEEP LAYER
SHEAR IS STRONG ENOUGH TO SUPPORT ORGANIZED CONVECTION THIS EVENING
AND COULD SEE THUNDERSTORMS BECOME LINEAR AS THEY MOVE WEST TO EAST
INTO NORTHERN ILLINOIS LATE THIS EVENING. THE SEVERE THREAT SHOULD
DIMINISH THROUGH THE LATE EVENING WITH LOSS OF DAYTIME HEATING...BUT
STRONG MOISTURE TRANSPORT AND PWATS PUSHING TOWARDS THE 2 INCH MARK
TONIGHT WOULD SUGGEST A HEAVY RAIN THREAT INTO THE OVERNIGHT HOURS.
SEVERAL MODELS PRODUCE QFP WELL OVER AN INCH SOMEWHERE ACROSS
NORTHERN ILLINOIS OVERNIGHT...THOUGH STILL CONSIDERABLE UNCERTAINTY
AS TO WHERE EXACTLY THE HEAVY PRECIP AXIS DEVELOPS. THERE IS A
DISTINCT POSSIBILITY THAT THE SOUTHERN HALF OF THE CWA IS FAVORED
DUE TO THE OUTFLOW BOUNDARIES FROM THIS MORNINGS CONVECTION LAYING
OUT ACROSS CENTRAL ILLINOIS TODAY AND SERVING AS THE FOCUS.
SUNDAY THROUGH MONDAY...
A SURFACE LOW WILL TRACK EAST ACROSS THE NORTHERN GREAT LAKES REGION
SUNDAY WITH A COLD FRONT LAYING OUT ACROSS NORTHERN ILLINOIS.
ADDITIONAL THUNDERSTORM CHANCES SHOULD GENERALLY BE ALONG AND OUT
AHEAD OF THE COLD FRONT AS IT SAGS SOUTH ACROSS THE CWA THROUGH THE
DAY AND MUCH DRIER MID LEVEL AIR FILTERS SOUTH. NOT MUCH COLD AIR
ASSOCIATED WITH THE FRONT AND SKIES CLEARING BEHIND SHOULD HELP
ALLOW TEMPS TO RISE INTO THE LOW TO MID 80S SUNDAY. SECONDARY
TROUGH/FRONT WILL SINK SOUTH ACROSS THE AREA WITH THE POTENTIAL FOR
ADDITIONAL THUNDERSTORMS MONDAY. GFS AT THIS POINT IS HAVING GROWING
ISSUES WITH CONVECTIVE FEEDBACK DEVELOPING A DEEP LOW OVER THE
PLAINS...THUS LEANED TOWARDS A BLEND OF NON-GFS SOLUTIONS WHICH
LOWERS POPS ACROSS THE CWA ON MONDAY.
TUESDAY THROUGH THURSDAY...
PERIOD WILL BE DOMINATED BY HIGH PRESSURE AND DRY CONDITIONS.
TEMPERATURES WILL MODERATE THROUGH THE PERIOD WITH TEMPS ONLY IN THE
70S TUESDAY WARMING INTO THE LOW 80S THURSDAY. LAKE BREEZES ARE
EXPECTED EACH DAY WHICH WILL KEEP TEMPS QUITE A BIT COOLER ALONG THE
LAKE FRONT.
DEUBELBEISS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* TIMING...MAGNITUDE...AND DURATION OF TSRA TOWARD EVENING.
LENNING
//DISCUSSION...UPDATED 18Z...
CONFIDENCE IN CONVECTIVE TRENDS TODAY AND THIS EVENING IS
INCREASING SOMEWHAT...WITH THE BASIC IDEA SIMILAR TO WHAT WAS
ALREADY BEING CONVEYED IN EARLIER FCST PRODUCTS. FACTORS THAT WERE
RESPONSIBLE FOR LAST NIGHTS CONVECTION OVER THE IA/MO/IL
INTERSECTION ARE DEPICTED TO OCCUR AGAIN TONIGHT...AND WITH
GREATER INTENSITY...ACROSS NORTHEAST ILLINOIS.
THE THOUGHT IS THAT EXISTING ACTIVITY TO THE SOUTHWEST OF THE
AREA...FROM MLI TO SPI...WILL ERODE FROM NORTH TO SOUTH AS IT
SLIDES EAST OR SOUTHEAST AND STAYS OUT OF THE LOCAL AREA. ACTIVITY
OVER NORTHERN IOWA ALSO IS BEGINNING TO FADE. NEW ACTIVITY IS
EXPECTED TO DEVELOP IN THE MOIST AND DESTABILIZING AIR OVER SOUTH
CENTRAL IOWA AND EVEN MORE SO ACROSS NORTHERN MISSOURI. THIS NEW
DEVELOPMENT WOULD WORK INTO THE CHICAGO TERMINALS TOWARD THE END
OF THE EVENING RUSH...SOMEWHERE IN THE 02Z TIMEFRAME.
OVERNIGHT THE FOCUS FOR THIS CONVECTION IS DEPICTED TO PUSH
THROUGH THE TERMINALS OVER A 2-3 HOUR PERIOD AND THEN EVENTUALLY DROP
SOUTH BY MORNING.
LENNING
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM CONFIDENCE IN TIMING OF CONVECTION INTO THE TERMINALS
THIS EVENING. LOWER CONFIDENCE IN MAGNITUDE OF WINDS AND REDUCED
VSBYS.
* MEDIUM TO HIGH CONFIDENCE THAT OVERNIGHT CONVECTION WILL PUSH
WELL SOUTH OF TERMINALS BY MORNING.
LENNING
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR.
MONDAY...CHANCE OF PM TSRA...OTHERWISE VFR.
TUESDAY THROUGH THURSDAY...VFR.
FRIDAY...CHANCE OF SHRA/TSRA.
IZZI
&&
.MARINE...
229 AM CDT
OUTSIDE OF THUNDERSTORM CHANCES...GENERALLY QUIET WEATHER ON THE
LAKE THROUGH THE WEEKEND WITH SOUTHERLY WINDS DEVELOPING. A COUPLE
OF COLD FRONT WILL MOVE ACROSS THE LAKE...FIRST ONE THIS WEEKEND
WITH WIND SHIFT TO WEST WITH THE SECONDARY...MORE ROBUST...FRONT
MOVING DOWN THE LAKE MONDAY INTO MONDAY NIGHT. COULD SEE A PERIOD
OF SOMEWHAT STRONGER NORTHERLY FLOW WITH THE COLD AIR ADVECTION
MONDAY NIGHT INTO TUESDAY...BUT STILL ONLY LOOKING AT A PERIOD OF
FORCE 3 WINDS FOR THE SOUTHERN PORTIONS OF THE LAKE AS A WORST
CASE SCENARIO. HIGH PRESSURE BUILDS BACK INTO THE REGION WITH
QUIET CONDITIONS AGAIN BY MID WEEK.
IZZI
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
133 PM CDT SAT JUN 15 2013
.DISCUSSION...
1147 AM CDT
VERY COMPLEX FORECAST UNFOLDING THIS AFTERNOON. TWO AREAS OF
CONVECTION ARE TO THE WEST AND SOUTH OF THE REGION WITH ANOTHER
LINE OF STORMS BEGINNING TO TAKE SHAPE FROM CEDAR RAPIDS IA TO
GALESBURG IL. MEANWHILE SHOWERS ARE STILL SLOWLY MAKING THEIR WAY
OUT OF NORTHERN IL AND IN. THE LINGERING STABLE CONDITIONS AND
CLOUD COVER DUE TO THE MORNING SHOWERS IS LIMITING INSTABILITY
OVER NORTHERN IL AND IN. HOWEVER...CONFIDENCE IS INCREASING ON
WHERE CONVECTION WILL OCCUR THIS AFTERNOON AND EVENING. GUIDANCE
AND OBS INDICATE INSTABILITY WILL INCREASE SOUTH OF A ROCKFORD IL
TO HEBRON IL LINE THIS AFTERNOON...WHICH WOULD SUGGEST THAT THE
LINE OF STORMS ACROSS EASTERN IA AND WEST CENTRAL IL WILL CONTINUE
TO MOVE EASTWARD. THINKING THAT LINE WILL BE OUR MAIN SHOW TODAY
WITH STRONG WINDS...HEAVY RAIN...AND FLASH FLOODING BE THE MAIN
CONCERNS.
THINKING THE COMPLEX OVER NORTH CENTRAL IA WILL SHIFT NORTHWARD
AND PASS THROUGH SOUTHERN WI. WILL KEEP SHOWERS AND THUNDERSTORMS
ACROSS THE ENTIRE CWA THIS AFTERNOON AND EVENING REGARDLESS...BUT
STILL THINK THE BEST CHANCE FOR SEVERE CONVECTION WILL BE SOUTH OF
A ROCKFORD IL TO HEBRON IN LINE.
JEE
//PREV DISCUSSION...
309 AM CDT
MAIN FORECAST CONCERNS THIS MORNING WILL BE DEALING WITH SEVERE
WEATHER CHANCES THIS AFTERNOON/EVENING AND HEAVY RAIN POTENTIAL THIS
EVENING AND TONIGHT.
TODAY AND TONIGHT...
EARLY THIS MORNING A CONVECTIVE COMPLEX IS PUSHING SOUTHEAST ACROSS
NORTHERN MISSOURI THOUGH HAS SHOWN SIGNS OF WEAKENING AS IT MOVES
FROM THE BETTER FORCING ASSOCIATED WITH THE LOW LEVEL JET FOCUSED
OVER CENTRAL IOWA. FARTHER NORTH UNORGANIZED AND WEAKER CONVECTION
SHOULD DIMINISH WITH PERHAPS A FEW LINGERING SHOWERS MOVING INTO THE
AREA THIS MORNING. AN MCV OVER SOUTHEASTERN IOWA WILL MOVE ESE
ACROSS CENTRAL ILLINOIS THIS MORNING AND SHOULD SUPPORT THE GREATEST
POPS OVER THE SOUTHERN CWA //LATEST RAP RUN SEEMS TO HANDLE THIS
FEATURE WELL//. HOW QUICKLY THESE SHOWERS CLEAR OUT AND THE
ASSOCIATED CLOUD COVER...INCLUDING THE CIRRUS CANOPY FROM THE MCS TO
THE SOUTHWEST WILL BE KEY TO BEING ABLE TO RECOVER AND SUPPORT
ADDITIONAL SEVERE WEATHER TODAY. DO EXPECT A LULL IN PRECIP LATE
THIS MORNING THROUGH MID AFTERNOON BETWEEN SYSTEMS.
GUIDANCE SUPPORTS AN AXIS OF MODERATE TO STRONG MLCAPE DEVELOPING
FROM KANSAS NORTHEAST INTO NORTHERN WISCONSIN THIS AFTERNOON WITH
NORTH CENTRAL ILLINOIS ON THE EASTERN PERIPHERY OF THE INSTABILITY.
WHILE INITIALLY CAPPED...A COMPACT WAVE MOVING ACROSS IOWA LATE THIS
AFTERNOON AND EARLY EVENING WILL HELP TO WEAKEN THE CAP ALLOWING FOR
STRONGER SURFACE BASED CONVECTION TO DEVELOP OVER IOWA. DEEP LAYER
SHEAR IS STRONG ENOUGH TO SUPPORT ORGANIZED CONVECTION THIS EVENING
AND COULD SEE THUNDERSTORMS BECOME LINEAR AS THEY MOVE WEST TO EAST
INTO NORTHERN ILLINOIS LATE THIS EVENING. THE SEVERE THREAT SHOULD
DIMINISH THROUGH THE LATE EVENING WITH LOSS OF DAYTIME HEATING...BUT
STRONG MOISTURE TRANSPORT AND PWATS PUSHING TOWARDS THE 2 INCH MARK
TONIGHT WOULD SUGGEST A HEAVY RAIN THREAT INTO THE OVERNIGHT HOURS.
SEVERAL MODELS PRODUCE QFP WELL OVER AN INCH SOMEWHERE ACROSS
NORTHERN ILLINOIS OVERNIGHT...THOUGH STILL CONSIDERABLE UNCERTAINTY
AS TO WHERE EXACTLY THE HEAVY PRECIP AXIS DEVELOPS. THERE IS A
DISTINCT POSSIBILITY THAT THE SOUTHERN HALF OF THE CWA IS FAVORED
DUE TO THE OUTFLOW BOUNDARIES FROM THIS MORNINGS CONVECTION LAYING
OUT ACROSS CENTRAL ILLINOIS TODAY AND SERVING AS THE FOCUS.
SUNDAY THROUGH MONDAY...
A SURFACE LOW WILL TRACK EAST ACROSS THE NORTHERN GREAT LAKES REGION
SUNDAY WITH A COLD FRONT LAYING OUT ACROSS NORTHERN ILLINOIS.
ADDITIONAL THUNDERSTORM CHANCES SHOULD GENERALLY BE ALONG AND OUT
AHEAD OF THE COLD FRONT AS IT SAGS SOUTH ACROSS THE CWA THROUGH THE
DAY AND MUCH DRIER MID LEVEL AIR FILTERS SOUTH. NOT MUCH COLD AIR
ASSOCIATED WITH THE FRONT AND SKIES CLEARING BEHIND SHOULD HELP
ALLOW TEMPS TO RISE INTO THE LOW TO MID 80S SUNDAY. SECONDARY
TROUGH/FRONT WILL SINK SOUTH ACROSS THE AREA WITH THE POTENTIAL FOR
ADDITIONAL THUNDERSTORMS MONDAY. GFS AT THIS POINT IS HAVING GROWING
ISSUES WITH CONVECTIVE FEEDBACK DEVELOPING A DEEP LOW OVER THE
PLAINS...THUS LEANED TOWARDS A BLEND OF NON-GFS SOLUTIONS WHICH
LOWERS POPS ACROSS THE CWA ON MONDAY.
TUESDAY THROUGH THURSDAY...
PERIOD WILL BE DOMINATED BY HIGH PRESSURE AND DRY CONDITIONS.
TEMPERATURES WILL MODERATE THROUGH THE PERIOD WITH TEMPS ONLY IN THE
70S TUESDAY WARMING INTO THE LOW 80S THURSDAY. LAKE BREEZES ARE
EXPECTED EACH DAY WHICH WILL KEEP TEMPS QUITE A BIT COOLER ALONG THE
LAKE FRONT.
DEUBELBEISS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* TIMING...MAGNITUDE...AND DURATION OF TSRA TOWARD EVENING.
LENNING
//DISCUSSION...UPDATED 18Z...
CONFIDENCE IN CONVECTIVE TRENDS TODAY AND THIS EVENING IS
INCREASING SOMEWHAT...WITH THE BASIC IDEA SIMILAR TO WHAT WAS
ALREADY BEING CONVEYED IN EARLIER FCST PRODUCTS. FACTORS THAT WERE
RESPONSIBLE FOR LAST NIGHTS CONVECTION OVER THE IA/MO/IL
INTERSECTION ARE DEPICTED TO OCCUR AGAIN TONIGHT...AND WITH
GREATER INTENSITY...ACROSS NORTHEAST ILLINOIS.
THE THOUGHT IS THAT EXISTING ACTIVITY TO THE SOUTHWEST OF THE
AREA...FROM MLI TO SPI...WILL ERODE FROM NORTH TO SOUTH AS IT
SLIDES EAST OR SOUTHEAST AND STAYS OUT OF THE LOCAL AREA. ACTIVITY
OVER NORTHERN IOWA ALSO IS BEGINNING TO FADE. NEW ACTIVITY IS
EXPECTED TO DEVELOP IN THE MOIST AND DESTABILIZING AIR OVER SOUTH
CENTRAL IOWA AND EVEN MORE SO ACROSS NORTHERN MISSOURI. THIS NEW
DEVELOPMENT WOULD WORK INTO THE CHICAGO TERMINALS TOWARD THE END
OF THE EVENING RUSH...SOMEWHERE IN THE 02Z TIMEFRAME.
OVERNIGHT THE FOCUS FOR THIS CONVECTION IS DEPICTED TO PUSH
THROUGH THE TERMINALS OVER A 2-3 HOUR PERIOD AND THEN EVENTUALLY DROP
SOUTH BY MORNING.
LENNING
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM CONFIDENCE IN TIMING OF CONVECTION INTO THE TERMINALS
THIS EVENING. LOWER CONFIDENCE IN MAGNITUDE OF WINDS AND REDUCED
VSBYS.
* MEDIUM TO HIGH CONFIDENCE THAT OVERNIGHT CONVECTION WILL PUSH
WELL SOUTH OF TERMINALS BY MORNING.
LENNING
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR.
MONDAY...CHANCE OF PM TSRA...OTHERWISE VFR.
TUESDAY THROUGH THURSDAY...VFR.
FRIDAY...CHANCE OF SHRA/TSRA.
IZZI
&&
.MARINE...
229 AM CDT
OUTSIDE OF THUNDERSTORM CHANCES...GENERALLY QUIET WEATHER ON THE
LAKE THROUGH THE WEEKEND WITH SOUTHERLY WINDS DEVELOPING. A COUPLE
OF COLD FRONT WILL MOVE ACROSS THE LAKE...FIRST ONE THIS WEEKEND
WITH WIND SHIFT TO WEST WITH THE SECONDARY...MORE ROBUST...FRONT
MOVING DOWN THE LAKE MONDAY INTO MONDAY NIGHT. COULD SEE A PERIOD
OF SOMEWHAT STRONGER NORTHERLY FLOW WITH THE COLD AIR ADVECTION
MONDAY NIGHT INTO TUESDAY...BUT STILL ONLY LOOKING AT A PERIOD OF
FORCE 3 WINDS FOR THE SOUTHERN PORTIONS OF THE LAKE AS A WORST
CASE SCENARIO. HIGH PRESSURE BUILDS BACK INTO THE REGION WITH
QUIET CONDITIONS AGAIN BY MID WEEK.
IZZI
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSCHICAGO
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AREA FORECAST DISCUSSION
NWS LINCOLN IL
1246 PM CDT SAT JUN 15 2013
.DISCUSSION...
ISSUED 1027 AM CDT SAT JUN 15 2013
MCV FROM OVERNIGHT MCS OVER IA NOW SHIFTING THROUGH NE IL.
MESOSCALE BOUNDARY SOUTHWEST OF THIS FEATURE LOOKS TO HAVE SET UP
FROM NEAR BURLINGTON TO SPRINGFIELD AND HAS BEEN THE FOCUS FOR A
CLUSTER OF TSTMS PAST FEW HOURS. THIS IS BEING MAINTAINED BY A
CONVERGENT +20C DEWPOINT FEED AT 925 MB FROM ERN KS AND NRN MO.
HEAVY DOWNPOURS LIKELY GIVEN VERY HIGH P/W OVER 1.6. FEEL THIS
WILL BE MOST CONCENTRATED AREA OF CONVECTION FOR NEXT FEW
HOURS...AS NOT MUCH OF A FOCUS ELSEWHERE AND HAVE REMOVED POPS
EAST OF I-57 AND ONLY HAVE SLIGHT CHANCE NORTH OF CURRENT
ACTIVITY. STILL NOT MUCH OF A FOCUS FOR ADDITIONAL DEVELOPMENT
THIS AFTERNOON...HOWEVER WITH LEFTOVER BOUNDARIES AND INCREASING
INSTABILITY CHANCE POPS FOR THE WESTERN HALF LOOK GOOD. INCREASING
SHEAR WOULD PROVIDE MORE ORGANIZATION LATER IN THE DAY...SO STRONG
OR ISOLATED SEVERE POSSIBLE. BEST CHANCE FOR SVR APPEARS TIED TO
A SHORTWAVE NOW LIFTING NORTHEAST THROUGH CENTRAL KS...AND AHEAD
OF A WEAK COLD FRONT SHIFTING THROUGH NW IA. THIS WOULD FAVOR MORE
INTENSE TSTM DEVELOPMENT OVER NRN MO LATER THIS AFTERNOON...WHICH
WOULD SHIFT INTO WESTERN IL LATE THIS AFTERNOON AND EVENING. HIGH
TEMPS WILL BE A CHALLENGE WITH AREAS OF CLOUD COVER AND PRECIP
ESPECIALLY ACROSS THE SOUTHWEST CWA...BUT SUNNIER LOCATIONS COULD
CERTAINLY SEE HIGHS IN THE MID 80S.
&&
.AVIATION...
ISSUED 1246 PM CDT SAT JUN 15 2013
MAINLY VFR CONDITIONS AGAIN NEXT 24 HOURS OUTSIDE OF
THUNDERSTORMS. CURRENT COMPLEX AFFECTING PARTS OF CENTRAL IL THIS
AFTERNOON WILL PRODUCE BRIEF VSBY REDUCTIONS DOWN TO 4SM AND
POSSIBLY BRIEFLY LOWER IN HEAVIER TSRA. NEXT BATCH OF STORMS
EXPECTED TO FORM OVER IA AND NRN MO LATER THIS AFTERNOON AND SHIFT
OVER THE TAF SITES THIS EVENING AND HAVE TEMPO GROUPS FOR MOST
LIKELY TIME OF OCCURRENCE. AFTER THIS SYSTEM PUSHES THROUGH MUCH
OF THE ACTIVITY SHOULD BE SUPPRESSED TO OUR SOUTH/EAST FOR SUNDAY
MORNING. CHANCE OF SOME VSBY REDUCTIONS AFTER 06Z IN LIGHT WIND
REGIME AND WITH WET GROUND AND HAVE TRENDED THIS DIRECTION FOR
MOST SITES.
25
&&
.PREV DISCUSSION...
ISSUED 243 AM CDT SAT JUN 15 2013
SHORT TERM...TODAY THROUGH MONDAY
07Z IR SATELLITE IMAGERY SHOWS WARMING CLOUD TOPS ASSOCIATED
WITH THE MCS OVER IOWA/NORTHERN MISSOURI. FURTHER DISSIPATION IS
ANTICIPATED AS THE SYSTEM TRACKS E/SE INTO AN INCREASINGLY
UNFAVORABLE AIR MASS EAST OF THE MISSISSIPPI RIVER EARLY THIS
MORNING. BIG QUESTION WILL BE HOW FAR EAST THE PRECIP WILL MAKE
IT BEFORE COMPLETELY DIMINISHING. AS IS TYPICALLY THE CASE WITH
CONVECTION...MOST MODEL GUIDANCE LEAVES A LOT TO BE DESIRED. THE
ONLY MODEL THAT SEEMS TO HAVE A DECENT HANDLE ON THE CURRENT
SITUATION IS THE 05Z HRRR...WHICH BRINGS SHOWERS ACROSS MUCH OF
CENTRAL ILLINOIS THIS MORNING BEFORE FINALLY DISSIPATING THEM
SOUTH OF I-70 TOWARD MIDDAY. GIVEN LATEST SATELLITE/RADAR
TRENDS...THIS SEEMS TO BE A PLAUSIBLE SOLUTION...SO WILL FOLLOW
CLOSELY FOR THE SHORT-TERM. AS A RESULT...WILL CARRY LIKELY POPS
FOR SHOWERS ALONG AND NORTHWEST OF A CHAMPAIGN TO SHELBYVILLE LINE
THROUGH MIDDAY...WITH JUST CHANCE POPS FURTHER E/SE. ONCE THE
DECAYING MCS EXITS INTO INDIANA...THE STABLE AIR MASS LEFT IN ITS
WAKE WILL RESULT IN A LULL IN PRECIP CHANCES FROM LATE MORNING
THROUGH MID-AFTERNOON. HRRR DEPICTS ADDITIONAL CONVECTION FIRING
FURTHER WEST WHERE MUCH GREATER INSTABILITY WILL DEVELOP ACROSS
KANSAS/MISSOURI AFTER 20Z. THINK THIS ACTIVITY WILL GRADUALLY
SPREAD E/NE INTO CENTRAL ILLINOIS LATE THIS AFTERNOON AND EVENING
AHEAD OF AN APPROACHING COLD FRONT. WITH GOOD CONVERGENCE ALONG
THE FRONT...UPPER SUPPORT PROVIDED BY A SIGNIFICANT SHORT-WAVE
TRACKING INTO THE SOUTHERN GREAT LAKES...AND AMPLE MID/LOW-LEVEL
MOISTURE IN PLACE...EXPECT WIDESPREAD SHOWERS/THUNDER ALONG
ADVANCING FRONT. WILL CARRY CATEGORICAL POPS ACROSS ALL BUT THE
FAR SE KILX CWA ACCORDINGLY TONIGHT.
DESPITE QUESTIONABLE CONVECTION FORECASTS IN THE IMMEDIATE
SHORT-TERM...SYNOPTIC MODELS ALL AGREE THAT FRONTAL BOUNDARY WILL
SAG SOUTHWARD THROUGH CENTRAL ILLINOIS ON SUNDAY...SHIFTING THE
GREATEST EMPHASIS FOR ADDITIONAL PRECIP FURTHER SOUTH. WITH WEAK
HIGH PRESSURE BUILDING INTO THE UPPER MIDWEST AND A SLIGHTLY DRIER
AIR MASS TRICKLING SOUTHWARD BEHIND THE BOUNDARY...HAVE REMOVED
MENTIONABLE POPS ACROSS THE NORTHERN CWA ON SUNDAY...THEN ACROSS
THE ENTIRE AREA SUNDAY NIGHT.
ANOTHER SHORT-WAVE TROUGH IS PROGGED TO DIG E/SE ACROSS THE UPPER
MIDWEST INTO THE GREAT LAKES EARLY NEXT WEEK. SYNOPTIC LIFT PROVIDED
BY THIS FEATURE IN CONJUNCTION WITH ANOTHER FRONTAL BOUNDARY IN
THE AREA WILL BE ENOUGH TO TRIGGER SCATTERED SHOWERS/THUNDER ON
MONDAY. FRONT WILL THEN SETTLE FURTHER SOUTHWARD MONDAY
NIGHT...TAKING RAIN CHANCES OUT OF THE AREA OVERNIGHT.
LONG TERM...TUESDAY THROUGH FRIDAY
A RELATIVELY QUIET PERIOD OF WEATHER IS EXPECTED IN THE
EXTENDED...AS A SOMEWHAT COOLER W/NW UPPER FLOW EARLY IN THE
PERIOD IS GRADUALLY REPLACED BY RIDGING BY THE END OF THE WEEK. AS
A RESULT...HIGH TEMPS IN THE UPPER 70S ON TUESDAY WILL WARM INTO
THE MIDDLE TO UPPER 80S BY FRIDAY. MODELS CONTINUE TO SPLASH LIGHT
QPF ACROSS THE AREA FROM TIME TO TIME THROUGHOUT THE
PERIOD...HOWEVER THINK THIS IS WAY OVERDONE. WILL KEEP MENTIONABLE
POPS OUT OF THE FORECAST...UNTIL STRONGER/MORE CONSISTENT SIGNALS
FOR PRECIP DEVELOP.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1210 PM CDT SAT JUN 15 2013
.DISCUSSION...
1147 AM CDT
VERY COMPLEX FORECAST UNFOLDING THIS AFTERNOON. TWO AREAS OF
CONVECTION ARE TO THE WEST AND SOUTH OF THE REGION WITH ANOTHER
LINE OF STORMS BEGINNING TO TAKE SHAPE FROM CEDAR RAPIDS IA TO
GALESBURG IL. MEANWHILE SHOWERS ARE STILL SLOWLY MAKING THEIR WAY
OUT OF NORTHERN IL AND IN. THE LINGERING STABLE CONDITIONS AND
CLOUD COVER DUE TO THE MORNING SHOWERS IS LIMITING INSTABILITY
OVER NORTHERN IL AND IN. HOWEVER...CONFIDENCE IS INCREASING ON
WHERE CONVECTION WILL OCCUR THIS AFTERNOON AND EVENING. GUIDANCE
AND OBS INDICATE INSTABILITY WILL INCREASE SOUTH OF A ROCKFORD IL
TO HEBRON IL LINE THIS AFTERNOON...WHICH WOULD SUGGEST THAT THE
LINE OF STORMS ACROSS EASTERN IA AND WEST CENTRAL IL WILL CONTINUE
TO MOVE EASTWARD. THINKING THAT LINE WILL BE OUR MAIN SHOW TODAY
WITH STRONG WINDS...HEAVY RAIN...AND FLASH FLOODING BE THE MAIN
CONCERNS.
THINKING THE COMPLEX OVER NORTH CENTRAL IA WILL SHIFT NORTHWARD
AND PASS THROUGH SOUTHERN WI. WILL KEEP SHOWERS AND THUNDERSTORMS
ACROSS THE ENTIRE CWA THIS AFTERNOON AND EVENING REGARDLESS...BUT
STILL THINK THE BEST CHANCE FOR SEVERE CONVECTION WILL BE SOUTH OF
A ROCKFORD IL TO HEBRON IN LINE.
JEE
&&
.PREV DISCUSSION...
309 AM CDT
MAIN FORECAST CONCERNS THIS MORNING WILL BE DEALING WITH SEVERE
WEATHER CHANCES THIS AFTERNOON/EVENING AND HEAVY RAIN POTENTIAL THIS
EVENING AND TONIGHT.
TODAY AND TONIGHT...
EARLY THIS MORNING A CONVECTIVE COMPLEX IS PUSHING SOUTHEAST ACROSS
NORTHERN MISSOURI THOUGH HAS SHOWN SIGNS OF WEAKENING AS IT MOVES
FROM THE BETTER FORCING ASSOCIATED WITH THE LOW LEVEL JET FOCUSED
OVER CENTRAL IOWA. FARTHER NORTH UNORGANIZED AND WEAKER CONVECTION
SHOULD DIMINISH WITH PERHAPS A FEW LINGERING SHOWERS MOVING INTO THE
AREA THIS MORNING. AN MCV OVER SOUTHEASTERN IOWA WILL MOVE ESE
ACROSS CENTRAL ILLINOIS THIS MORNING AND SHOULD SUPPORT THE GREATEST
POPS OVER THE SOUTHERN CWA //LATEST RAP RUN SEEMS TO HANDLE THIS
FEATURE WELL//. HOW QUICKLY THESE SHOWERS CLEAR OUT AND THE
ASSOCIATED CLOUD COVER...INCLUDING THE CIRRUS CANOPY FROM THE MCS TO
THE SOUTHWEST WILL BE KEY TO BEING ABLE TO RECOVER AND SUPPORT
ADDITIONAL SEVERE WEATHER TODAY. DO EXPECT A LULL IN PRECIP LATE
THIS MORNING THROUGH MID AFTERNOON BETWEEN SYSTEMS.
GUIDANCE SUPPORTS AN AXIS OF MODERATE TO STRONG MLCAPE DEVELOPING
FROM KANSAS NORTHEAST INTO NORTHERN WISCONSIN THIS AFTERNOON WITH
NORTH CENTRAL ILLINOIS ON THE EASTERN PERIPHERY OF THE INSTABILITY.
WHILE INITIALLY CAPPED...A COMPACT WAVE MOVING ACROSS IOWA LATE THIS
AFTERNOON AND EARLY EVENING WILL HELP TO WEAKEN THE CAP ALLOWING FOR
STRONGER SURFACE BASED CONVECTION TO DEVELOP OVER IOWA. DEEP LAYER
SHEAR IS STRONG ENOUGH TO SUPPORT ORGANIZED CONVECTION THIS EVENING
AND COULD SEE THUNDERSTORMS BECOME LINEAR AS THEY MOVE WEST TO EAST
INTO NORTHERN ILLINOIS LATE THIS EVENING. THE SEVERE THREAT SHOULD
DIMINISH THROUGH THE LATE EVENING WITH LOSS OF DAYTIME HEATING...BUT
STRONG MOISTURE TRANSPORT AND PWATS PUSHING TOWARDS THE 2 INCH MARK
TONIGHT WOULD SUGGEST A HEAVY RAIN THREAT INTO THE OVERNIGHT HOURS.
SEVERAL MODELS PRODUCE QFP WELL OVER AN INCH SOMEWHERE ACROSS
NORTHERN ILLINOIS OVERNIGHT...THOUGH STILL CONSIDERABLE UNCERTAINTY
AS TO WHERE EXACTLY THE HEAVY PRECIP AXIS DEVELOPS. THERE IS A
DISTINCT POSSIBILITY THAT THE SOUTHERN HALF OF THE CWA IS FAVORED
DUE TO THE OUTFLOW BOUNDARIES FROM THIS MORNINGS CONVECTION LAYING
OUT ACROSS CENTRAL ILLINOIS TODAY AND SERVING AS THE FOCUS.
SUNDAY THROUGH MONDAY...
A SURFACE LOW WILL TRACK EAST ACROSS THE NORTHERN GREAT LAKES REGION
SUNDAY WITH A COLD FRONT LAYING OUT ACROSS NORTHERN ILLINOIS.
ADDITIONAL THUNDERSTORM CHANCES SHOULD GENERALLY BE ALONG AND OUT
AHEAD OF THE COLD FRONT AS IT SAGS SOUTH ACROSS THE CWA THROUGH THE
DAY AND MUCH DRIER MID LEVEL AIR FILTERS SOUTH. NOT MUCH COLD AIR
ASSOCIATED WITH THE FRONT AND SKIES CLEARING BEHIND SHOULD HELP
ALLOW TEMPS TO RISE INTO THE LOW TO MID 80S SUNDAY. SECONDARY
TROUGH/FRONT WILL SINK SOUTH ACROSS THE AREA WITH THE POTENTIAL FOR
ADDITIONAL THUNDERSTORMS MONDAY. GFS AT THIS POINT IS HAVING GROWING
ISSUES WITH CONVECTIVE FEEDBACK DEVELOPING A DEEP LOW OVER THE
PLAINS...THUS LEANED TOWARDS A BLEND OF NON-GFS SOLUTIONS WHICH
LOWERS POPS ACROSS THE CWA ON MONDAY.
TUESDAY THROUGH THURSDAY...
PERIOD WILL BE DOMINATED BY HIGH PRESSURE AND DRY CONDITIONS.
TEMPERATURES WILL MODERATE THROUGH THE PERIOD WITH TEMPS ONLY IN THE
70S TUESDAY WARMING INTO THE LOW 80S THURSDAY. LAKE BREEZES ARE
EXPECTED EACH DAY WHICH WILL KEEP TEMPS QUITE A BIT COOLER ALONG THE
LAKE FRONT.
DEUBELBEISS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* LINGERING SHOWERS WITH POSSIBLE 3-5 SM VSBYS INTO THE AFTERNOON.
* VARIABLE BUT GENERALLY LIGHT WINDS.
* TIMING AND EXTENT OF CONVECTION TOWARD EVENING.
LENNING
//DISCUSSION...UPDATED 12Z...
WEAKENING CLUSTER OF STORMS WITH ASSOCIATED UPPER LEVEL
DISTURBANCE WILL MOVE ACROSS THE REGION THIS MORNING WITH WDLY SCT
SHRA AND POSSIBLY A TSRA UNTIL THIS DISTURBANCE MOVES EAST BY
MIDDAY. CANNOT TOTALLY RULE OUT ISOLD SHRA/TSRA THIS AFTERNOON BUT
CHANCES LOOK SLIM THROUGH EARLY EVENING. STRONG-SEVERE TSRA
EXPECTED TO DEVELOP OVER CENTRAL/EASTERN IOWA THIS AFTERNOON AND
MOVE QUICKLY EAST ACROSS NORTHERN/CENTRAL ILLINOIS THIS EVENING.
OTHER MINOR CONCERN IS WITH WINDS TODAY. INITIALLY EASTERLY WINDS
SHOULD VEER MORE SOUTHEASTERLY WITH SYNOPTIC GRADIENT FAVORING A
SHIFT TO SOUTH BY MIDDAY...BUT GIVEN THE DECAYING TSRA CLUSTER
UPSTREAM THE WIND FIELD COULD BECOME DISTURBED AND POTENTIALLY
SOMEWHAT ERRATIC FOR A TIME LATER THIS MORNING INTO THE EARLY
AFTERNOON. QUITE POSSIBLE THAT TERMINALS MAY MAINTAIN A MORE
EASTERLY COMPONENT TO THE WINDS INTO THE EARLLY AFTERNOON BEFORE
EVENTUALLY TRANSITIONING TO SOUTH DURING THE AFTERNOON.
IZZI
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM CONFIDENCE IN VCSH AT LEAST INTO EARLY AFTERNOON.
* MEDIUM TO HIGH CONFIDENCE THAT VSBYS STAY ABOVE IFR.
* MEDIUM TO LOW CONFIDENCE ON TSRA TRENDS TOWARD EVENING.
LENNING
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR.
MONDAY...CHANCE OF PM TSRA...OTHERWISE VFR.
TUESDAY THROUGH THURSDAY...VFR.
FRIDAY...CHANCE OF SHRA/TSRA.
IZZI
&&
.MARINE...
229 AM CDT
OUTSIDE OF THUNDERSTORM CHANCES...GENERALLY QUIET WEATHER ON THE
LAKE THROUGH THE WEEKEND WITH SOUTHERLY WINDS DEVELOPING. A COUPLE
OF COLD FRONT WILL MOVE ACROSS THE LAKE...FIRST ONE THIS WEEKEND
WITH WIND SHIFT TO WEST WITH THE SECONDARY...MORE ROBUST...FRONT
MOVING DOWN THE LAKE MONDAY INTO MONDAY NIGHT. COULD SEE A PERIOD
OF SOMEWHAT STRONGER NORTHERLY FLOW WITH THE COLD AIR ADVECTION
MONDAY NIGHT INTO TUESDAY...BUT STILL ONLY LOOKING AT A PERIOD OF
FORCE 3 WINDS FOR THE SOUTHERN PORTIONS OF THE LAKE AS A WORST
CASE SCENARIO. HIGH PRESSURE BUILDS BACK INTO THE REGION WITH
QUIET CONDITIONS AGAIN BY MID WEEK.
IZZI
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1114 AM CDT SAT JUN 15 2013
.DISCUSSION...
309 AM CDT
MAIN FORECAST CONCERNS THIS MORNING WILL BE DEALING WITH SEVERE
WEATHER CHANCES THIS AFTERNOON/EVENING AND HEAVY RAIN POTENTIAL THIS
EVENING AND TONIGHT.
TODAY AND TONIGHT...
EARLY THIS MORNING A CONVECTIVE COMPLEX IS PUSHING SOUTHEAST ACROSS
NORTHERN MISSOURI THOUGH HAS SHOWN SIGNS OF WEAKENING AS IT MOVES
FROM THE BETTER FORCING ASSOCIATED WITH THE LOW LEVEL JET FOCUSED
OVER CENTRAL IOWA. FARTHER NORTH UNORGANIZED AND WEAKER CONVECTION
SHOULD DIMINISH WITH PERHAPS A FEW LINGERING SHOWERS MOVING INTO THE
AREA THIS MORNING. AN MCV OVER SOUTHEASTERN IOWA WILL MOVE ESE
ACROSS CENTRAL ILLINOIS THIS MORNING AND SHOULD SUPPORT THE GREATEST
POPS OVER THE SOUTHERN CWA //LATEST RAP RUN SEEMS TO HANDLE THIS
FEATURE WELL//. HOW QUICKLY THESE SHOWERS CLEAR OUT AND THE
ASSOCIATED CLOUD COVER...INCLUDING THE CIRRUS CANOPY FROM THE MCS TO
THE SOUTHWEST WILL BE KEY TO BEING ABLE TO RECOVER AND SUPPORT
ADDITIONAL SEVERE WEATHER TODAY. DO EXPECT A LULL IN PRECIP LATE
THIS MORNING THROUGH MID AFTERNOON BETWEEN SYSTEMS.
GUIDANCE SUPPORTS AN AXIS OF MODERATE TO STRONG MLCAPE DEVELOPING
FROM KANSAS NORTHEAST INTO NORTHERN WISCONSIN THIS AFTERNOON WITH
NORTH CENTRAL ILLINOIS ON THE EASTERN PERIPHERY OF THE INSTABILITY.
WHILE INITIALLY CAPPED...A COMPACT WAVE MOVING ACROSS IOWA LATE THIS
AFTERNOON AND EARLY EVENING WILL HELP TO WEAKEN THE CAP ALLOWING FOR
STRONGER SURFACE BASED CONVECTION TO DEVELOP OVER IOWA. DEEP LAYER
SHEAR IS STRONG ENOUGH TO SUPPORT ORGANIZED CONVECTION THIS EVENING
AND COULD SEE THUNDERSTORMS BECOME LINEAR AS THEY MOVE WEST TO EAST
INTO NORTHERN ILLINOIS LATE THIS EVENING. THE SEVERE THREAT SHOULD
DIMINISH THROUGH THE LATE EVENING WITH LOSS OF DAYTIME HEATING...BUT
STRONG MOISTURE TRANSPORT AND PWATS PUSHING TOWARDS THE 2 INCH MARK
TONIGHT WOULD SUGGEST A HEAVY RAIN THREAT INTO THE OVERNIGHT HOURS.
SEVERAL MODELS PRODUCE QFP WELL OVER AN INCH SOMEWHERE ACROSS
NORTHERN ILLINOIS OVERNIGHT...THOUGH STILL CONSIDERABLE UNCERTAINTY
AS TO WHERE EXACTLY THE HEAVY PRECIP AXIS DEVELOPS. THERE IS A
DISTINCT POSSIBILITY THAT THE SOUTHERN HALF OF THE CWA IS FAVORED
DUE TO THE OUTFLOW BOUNDARIES FROM THIS MORNINGS CONVECTION LAYING
OUT ACROSS CENTRAL ILLINOIS TODAY AND SERVING AS THE FOCUS.
SUNDAY THROUGH MONDAY...
A SURFACE LOW WILL TRACK EAST ACROSS THE NORTHERN GREAT LAKES REGION
SUNDAY WITH A COLD FRONT LAYING OUT ACROSS NORTHERN ILLINOIS.
ADDITIONAL THUNDERSTORM CHANCES SHOULD GENERALLY BE ALONG AND OUT
AHEAD OF THE COLD FRONT AS IT SAGS SOUTH ACROSS THE CWA THROUGH THE
DAY AND MUCH DRIER MID LEVEL AIR FILTERS SOUTH. NOT MUCH COLD AIR
ASSOCIATED WITH THE FRONT AND SKIES CLEARING BEHIND SHOULD HELP
ALLOW TEMPS TO RISE INTO THE LOW TO MID 80S SUNDAY. SECONDARY
TROUGH/FRONT WILL SINK SOUTH ACROSS THE AREA WITH THE POTENTIAL FOR
ADDITIONAL THUNDERSTORMS MONDAY. GFS AT THIS POINT IS HAVING GROWING
ISSUES WITH CONVECTIVE FEEDBACK DEVELOPING A DEEP LOW OVER THE
PLAINS...THUS LEANED TOWARDS A BLEND OF NON-GFS SOLUTIONS WHICH
LOWERS POPS ACROSS THE CWA ON MONDAY.
TUESDAY THROUGH THURSDAY...
PERIOD WILL BE DOMINATED BY HIGH PRESSURE AND DRY CONDITIONS.
TEMPERATURES WILL MODERATE THROUGH THE PERIOD WITH TEMPS ONLY IN THE
70S TUESDAY WARMING INTO THE LOW 80S THURSDAY. LAKE BREEZES ARE
EXPECTED EACH DAY WHICH WILL KEEP TEMPS QUITE A BIT COOLER ALONG THE
LAKE FRONT.
DEUBELBEISS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* LINGERING SHOWERS WITH POSSIBLE 3-5 SM VSBYS INTO THE AFTERNOON.
* VARIABLE BUT GENERALLY LIGHT WINDS.
* TIMING AND EXTENT OF CONVECTION TOWARD EVENING.
LENNING
//DISCUSSION...UPDATED 12Z...
WEAKENING CLUSTER OF STORMS WITH ASSOCIATED UPPER LEVEL
DISTURBANCE WILL MOVE ACROSS THE REGION THIS MORNING WITH WDLY SCT
SHRA AND POSSIBLY A TSRA UNTIL THIS DISTURBANCE MOVES EAST BY
MIDDAY. CANNOT TOTALLY RULE OUT ISOLD SHRA/TSRA THIS AFTERNOON BUT
CHANCES LOOK SLIM THROUGH EARLY EVENING. STRONG-SEVERE TSRA
EXPECTED TO DEVELOP OVER CENTRAL/EASTERN IOWA THIS AFTERNOON AND
MOVE QUICKLY EAST ACROSS NORTHERN/CENTRAL ILLINOIS THIS EVENING.
OTHER MINOR CONCERN IS WITH WINDS TODAY. INITIALLY EASTERLY WINDS
SHOULD VEER MORE SOUTHEASTERLY WITH SYNOPTIC GRADIENT FAVORING A
SHIFT TO SOUTH BY MIDDAY...BUT GIVEN THE DECAYING TSRA CLUSTER
UPSTREAM THE WIND FIELD COULD BECOME DISTURBED AND POTENTIALLY
SOMEWHAT ERRATIC FOR A TIME LATER THIS MORNING INTO THE EARLY
AFTERNOON. QUITE POSSIBLE THAT TERMINALS MAY MAINTAIN A MORE
EASTERLY COMPONENT TO THE WINDS INTO THE EARLLY AFTERNOON BEFORE
EVENTUALLY TRANSITIONING TO SOUTH DURING THE AFTERNOON.
IZZI
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM CONFIDENCE IN VCSH AT LEAST INTO EARLY AFTERNOON.
* MEDIUM TO HIGH CONFIDENCE THAT VSBYS STAY ABOVE IFR.
* MEDIUM TO LOW CONFIDENCE ON TSRA TRENDS TOWARD EVENING.
LENNING
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR.
MONDAY...CHANCE OF PM TSRA...OTHERWISE VFR.
TUESDAY THROUGH THURSDAY...VFR.
FRIDAY...CHANCE OF SHRA/TSRA.
IZZI
&&
.MARINE...
229 AM CDT
OUTSIDE OF THUNDERSTORM CHANCES...GENERALLY QUIET WEATHER ON THE
LAKE THROUGH THE WEEKEND WITH SOUTHERLY WINDS DEVELOPING. A COUPLE
OF COLD FRONT WILL MOVE ACROSS THE LAKE...FIRST ONE THIS WEEKEND
WITH WIND SHIFT TO WEST WITH THE SECONDARY...MORE ROBUST...FRONT
MOVING DOWN THE LAKE MONDAY INTO MONDAY NIGHT. COULD SEE A PERIOD
OF SOMEWHAT STRONGER NORTHERLY FLOW WITH THE COLD AIR ADVECTION
MONDAY NIGHT INTO TUESDAY...BUT STILL ONLY LOOKING AT A PERIOD OF
FORCE 3 WINDS FOR THE SOUTHERN PORTIONS OF THE LAKE AS A WORST
CASE SCENARIO. HIGH PRESSURE BUILDS BACK INTO THE REGION WITH
QUIET CONDITIONS AGAIN BY MID WEEK.
IZZI
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1027 AM CDT SAT JUN 15 2013
.DISCUSSION...
ISSUED 1027 AM CDT SAT JUN 15 2013
MCV FROM OVERNIGHT MCS OVER IA NOW SHIFTING THROUGH NE IL.
MESOSCALE BOUNDARY SOUTHWEST OF THIS FEATURE LOOKS TO HAVE SET UP
FROM NEAR BURLINGTON TO SPRINGFIELD AND HAS BEEN THE FOCUS FOR A
CLUSTER OF TSTMS PAST FEW HOURS. THIS IS BEING MAINTAINED BY A
CONVERGENT +20C DEWPOINT FEED AT 925 MB FROM ERN KS AND NRN MO.
HEAVY DOWNPOURS LIKELY GIVEN VERY HIGH P/W OVER 1.6. FEEL THIS
WILL BE MOST CONCENTRATED AREA OF CONVECTION FOR NEXT FEW
HOURS...AS NOT MUCH OF A FOCUS ELSEWHERE AND HAVE REMOVED POPS
EAST OF I-57 AND ONLY HAVE SLIGHT CHANCE NORTH OF CURRENT
ACTIVITY. STILL NOT MUCH OF A FOCUS FOR ADDITIONAL DEVELOPMENT
THIS AFTERNOON...HOWEVER WITH LEFTOVER BOUNDARIES AND INCREASING
INSTABILITY CHANCE POPS FOR THE WESTERN HALF LOOK GOOD. INCREASING
SHEAR WOULD PROVIDE MORE ORGANIZATION LATER IN THE DAY...SO STRONG
OR ISOLATED SEVERE POSSIBLE. BEST CHANCE FOR SVR APPEARS TIED TO
A SHORTWAVE NOW LIFTING NORTHEAST THROUGH CENTRAL KS...AND AHEAD
OF A WEAK COLD FRONT SHIFTING THROUGH NW IA. THIS WOULD FAVOR MORE
INTENSE TSTM DEVELOPMENT OVER NRN MO LATER THIS AFTERNOON...WHICH
WOULD SHIFT INTO WESTERN IL LATE THIS AFTERNOON AND EVENING. HIGH
TEMPS WILL BE A CHALLENGE WITH AREAS OF CLOUD COVER AND PRECIP
ESPECIALLY ACROSS THE SOUTHWEST CWA...BUT SUNNIER LOCATIONS COULD
CERTAINLY SEE HIGHS IN THE MID 80S.
25
&&
.AVIATION...
ISSUED 635 AM CDT SAT JUN 15 2013
TRICKY TAF FORECAST DUE TO TIMING OF CONVECTIVE REDEVELOPMENT.
EARLIER MCS HAS FADED QUICKLY THE LAST COUPLE HOURS...AND WILL
ONLY SEE A FEW SHOWERS OVER THE TAF SITES THROUGH ABOUT MID
MORNING. CLUSTER OF SHOWERS CURRENTLY IN THE SOUTHEAST TIP OF
IOWA ON TRACK TO REACH KPIA BY 1430Z IF IT HOLDS TOGETHER. THINK
THERE WILL BE A LULL IN THE PRECIP FOR A GOOD PORTION OF THE LATE
MORNING AND EARLY AFTERNOON BEFORE MORE STORMS BEGIN TO REDEVELOP.
MODELS ARE HAVING A HARD TIME AGREEING ON THE LOCATION OF THIS
REDEVELOPMENT...NOT UNUSUAL GIVEN THAT LEFTOVER SUBTLE BOUNDARIES
FROM THE MORNING CONVECTION WILL PLAY A ROLE. THUS...WILL
GENERALLY STICK WITH VCTS MENTION UNTIL MORE CONSISTENT SIGNALS
APPEAR...ALTHOUGH HAVE INCLUDED A FEW HOURS OF TEMPO TSRA PERIODS
LATE AS A FRONTAL BOUNDARY PUSHES THROUGH THE AREA.
GEELHART
&&
.PREV DISCUSSION...
ISSUED 243 AM CDT SAT JUN 15 2013
SHORT TERM...TODAY THROUGH MONDAY
07Z IR SATELLITE IMAGERY SHOWS WARMING CLOUD TOPS ASSOCIATED
WITH THE MCS OVER IOWA/NORTHERN MISSOURI. FURTHER DISSIPATION IS
ANTICIPATED AS THE SYSTEM TRACKS E/SE INTO AN INCREASINGLY
UNFAVORABLE AIR MASS EAST OF THE MISSISSIPPI RIVER EARLY THIS
MORNING. BIG QUESTION WILL BE HOW FAR EAST THE PRECIP WILL MAKE
IT BEFORE COMPLETELY DIMINISHING. AS IS TYPICALLY THE CASE WITH
CONVECTION...MOST MODEL GUIDANCE LEAVES A LOT TO BE DESIRED. THE
ONLY MODEL THAT SEEMS TO HAVE A DECENT HANDLE ON THE CURRENT
SITUATION IS THE 05Z HRRR...WHICH BRINGS SHOWERS ACROSS MUCH OF
CENTRAL ILLINOIS THIS MORNING BEFORE FINALLY DISSIPATING THEM
SOUTH OF I-70 TOWARD MIDDAY. GIVEN LATEST SATELLITE/RADAR
TRENDS...THIS SEEMS TO BE A PLAUSIBLE SOLUTION...SO WILL FOLLOW
CLOSELY FOR THE SHORT-TERM. AS A RESULT...WILL CARRY LIKELY POPS
FOR SHOWERS ALONG AND NORTHWEST OF A CHAMPAIGN TO SHELBYVILLE LINE
THROUGH MIDDAY...WITH JUST CHANCE POPS FURTHER E/SE. ONCE THE
DECAYING MCS EXITS INTO INDIANA...THE STABLE AIR MASS LEFT IN ITS
WAKE WILL RESULT IN A LULL IN PRECIP CHANCES FROM LATE MORNING
THROUGH MID-AFTERNOON. HRRR DEPICTS ADDITIONAL CONVECTION FIRING
FURTHER WEST WHERE MUCH GREATER INSTABILITY WILL DEVELOP ACROSS
KANSAS/MISSOURI AFTER 20Z. THINK THIS ACTIVITY WILL GRADUALLY
SPREAD E/NE INTO CENTRAL ILLINOIS LATE THIS AFTERNOON AND EVENING
AHEAD OF AN APPROACHING COLD FRONT. WITH GOOD CONVERGENCE ALONG
THE FRONT...UPPER SUPPORT PROVIDED BY A SIGNIFICANT SHORT-WAVE
TRACKING INTO THE SOUTHERN GREAT LAKES...AND AMPLE MID/LOW-LEVEL
MOISTURE IN PLACE...EXPECT WIDESPREAD SHOWERS/THUNDER ALONG
ADVANCING FRONT. WILL CARRY CATEGORICAL POPS ACROSS ALL BUT THE
FAR SE KILX CWA ACCORDINGLY TONIGHT.
DESPITE QUESTIONABLE CONVECTION FORECASTS IN THE IMMEDIATE
SHORT-TERM...SYNOPTIC MODELS ALL AGREE THAT FRONTAL BOUNDARY WILL
SAG SOUTHWARD THROUGH CENTRAL ILLINOIS ON SUNDAY...SHIFTING THE
GREATEST EMPHASIS FOR ADDITIONAL PRECIP FURTHER SOUTH. WITH WEAK
HIGH PRESSURE BUILDING INTO THE UPPER MIDWEST AND A SLIGHTLY DRIER
AIR MASS TRICKLING SOUTHWARD BEHIND THE BOUNDARY...HAVE REMOVED
MENTIONABLE POPS ACROSS THE NORTHERN CWA ON SUNDAY...THEN ACROSS
THE ENTIRE AREA SUNDAY NIGHT.
ANOTHER SHORT-WAVE TROUGH IS PROGGED TO DIG E/SE ACROSS THE UPPER
MIDWEST INTO THE GREAT LAKES EARLY NEXT WEEK. SYNOPTIC LIFT PROVIDED
BY THIS FEATURE IN CONJUNCTION WITH ANOTHER FRONTAL BOUNDARY IN
THE AREA WILL BE ENOUGH TO TRIGGER SCATTERED SHOWERS/THUNDER ON
MONDAY. FRONT WILL THEN SETTLE FURTHER SOUTHWARD MONDAY
NIGHT...TAKING RAIN CHANCES OUT OF THE AREA OVERNIGHT.
LONG TERM...TUESDAY THROUGH FRIDAY
A RELATIVELY QUIET PERIOD OF WEATHER IS EXPECTED IN THE
EXTENDED...AS A SOMEWHAT COOLER W/NW UPPER FLOW EARLY IN THE
PERIOD IS GRADUALLY REPLACED BY RIDGING BY THE END OF THE WEEK. AS
A RESULT...HIGH TEMPS IN THE UPPER 70S ON TUESDAY WILL WARM INTO
THE MIDDLE TO UPPER 80S BY FRIDAY. MODELS CONTINUE TO SPLASH LIGHT
QPF ACROSS THE AREA FROM TIME TO TIME THROUGHOUT THE
PERIOD...HOWEVER THINK THIS IS WAY OVERDONE. WILL KEEP MENTIONABLE
POPS OUT OF THE FORECAST...UNTIL STRONGER/MORE CONSISTENT SIGNALS
FOR PRECIP DEVELOP.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
922 AM CDT SAT JUN 15 2013
.DISCUSSION...
309 AM CDT
MAIN FORECAST CONCERNS THIS MORNING WILL BE DEALING WITH SEVERE
WEATHER CHANCES THIS AFTERNOON/EVENING AND HEAVY RAIN POTENTIAL THIS
EVENING AND TONIGHT.
TODAY AND TONIGHT...
EARLY THIS MORNING A CONVECTIVE COMPLEX IS PUSHING SOUTHEAST ACROSS
NORTHERN MISSOURI THOUGH HAS SHOWN SIGNS OF WEAKENING AS IT MOVES
FROM THE BETTER FORCING ASSOCIATED WITH THE LOW LEVEL JET FOCUSED
OVER CENTRAL IOWA. FARTHER NORTH UNORGANIZED AND WEAKER CONVECTION
SHOULD DIMINISH WITH PERHAPS A FEW LINGERING SHOWERS MOVING INTO THE
AREA THIS MORNING. AN MCV OVER SOUTHEASTERN IOWA WILL MOVE ESE
ACROSS CENTRAL ILLINOIS THIS MORNING AND SHOULD SUPPORT THE GREATEST
POPS OVER THE SOUTHERN CWA //LATEST RAP RUN SEEMS TO HANDLE THIS
FEATURE WELL//. HOW QUICKLY THESE SHOWERS CLEAR OUT AND THE
ASSOCIATED CLOUD COVER...INCLUDING THE CIRRUS CANOPY FROM THE MCS TO
THE SOUTHWEST WILL BE KEY TO BEING ABLE TO RECOVER AND SUPPORT
ADDITIONAL SEVERE WEATHER TODAY. DO EXPECT A LULL IN PRECIP LATE
THIS MORNING THROUGH MID AFTERNOON BETWEEN SYSTEMS.
GUIDANCE SUPPORTS AN AXIS OF MODERATE TO STRONG MLCAPE DEVELOPING
FROM KANSAS NORTHEAST INTO NORTHERN WISCONSIN THIS AFTERNOON WITH
NORTH CENTRAL ILLINOIS ON THE EASTERN PERIPHERY OF THE INSTABILITY.
WHILE INITIALLY CAPPED...A COMPACT WAVE MOVING ACROSS IOWA LATE THIS
AFTERNOON AND EARLY EVENING WILL HELP TO WEAKEN THE CAP ALLOWING FOR
STRONGER SURFACE BASED CONVECTION TO DEVELOP OVER IOWA. DEEP LAYER
SHEAR IS STRONG ENOUGH TO SUPPORT ORGANIZED CONVECTION THIS EVENING
AND COULD SEE THUNDERSTORMS BECOME LINEAR AS THEY MOVE WEST TO EAST
INTO NORTHERN ILLINOIS LATE THIS EVENING. THE SEVERE THREAT SHOULD
DIMINISH THROUGH THE LATE EVENING WITH LOSS OF DAYTIME HEATING...BUT
STRONG MOISTURE TRANSPORT AND PWATS PUSHING TOWARDS THE 2 INCH MARK
TONIGHT WOULD SUGGEST A HEAVY RAIN THREAT INTO THE OVERNIGHT HOURS.
SEVERAL MODELS PRODUCE QFP WELL OVER AN INCH SOMEWHERE ACROSS
NORTHERN ILLINOIS OVERNIGHT...THOUGH STILL CONSIDERABLE UNCERTAINTY
AS TO WHERE EXACTLY THE HEAVY PRECIP AXIS DEVELOPS. THERE IS A
DISTINCT POSSIBILITY THAT THE SOUTHERN HALF OF THE CWA IS FAVORED
DUE TO THE OUTFLOW BOUNDARIES FROM THIS MORNINGS CONVECTION LAYING
OUT ACROSS CENTRAL ILLINOIS TODAY AND SERVING AS THE FOCUS.
SUNDAY THROUGH MONDAY...
A SURFACE LOW WILL TRACK EAST ACROSS THE NORTHERN GREAT LAKES REGION
SUNDAY WITH A COLD FRONT LAYING OUT ACROSS NORTHERN ILLINOIS.
ADDITIONAL THUNDERSTORM CHANCES SHOULD GENERALLY BE ALONG AND OUT
AHEAD OF THE COLD FRONT AS IT SAGS SOUTH ACROSS THE CWA THROUGH THE
DAY AND MUCH DRIER MID LEVEL AIR FILTERS SOUTH. NOT MUCH COLD AIR
ASSOCIATED WITH THE FRONT AND SKIES CLEARING BEHIND SHOULD HELP
ALLOW TEMPS TO RISE INTO THE LOW TO MID 80S SUNDAY. SECONDARY
TROUGH/FRONT WILL SINK SOUTH ACROSS THE AREA WITH THE POTENTIAL FOR
ADDITIONAL THUNDERSTORMS MONDAY. GFS AT THIS POINT IS HAVING GROWING
ISSUES WITH CONVECTIVE FEEDBACK DEVELOPING A DEEP LOW OVER THE
PLAINS...THUS LEANED TOWARDS A BLEND OF NON-GFS SOLUTIONS WHICH
LOWERS POPS ACROSS THE CWA ON MONDAY.
TUESDAY THROUGH THURSDAY...
PERIOD WILL BE DOMINATED BY HIGH PRESSURE AND DRY CONDITIONS.
TEMPERATURES WILL MODERATE THROUGH THE PERIOD WITH TEMPS ONLY IN THE
70S TUESDAY WARMING INTO THE LOW 80S THURSDAY. LAKE BREEZES ARE
EXPECTED EACH DAY WHICH WILL KEEP TEMPS QUITE A BIT COOLER ALONG THE
LAKE FRONT.
DEUBELBEISS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* LIGHT SHOWERS THIS MORNING WITH ERRATIC BUT LIGHT WINDS.
* BETTER CHANCE OF TSRA...POSSIBLY STRONG...THIS EVENING.
LENNING
//DISCUSSION...UPDATED 12Z...
WEAKENING CLUSTER OF STORMS WITH ASSOCIATED UPPER LEVEL
DISTURBANCE WILL MOVE ACROSS THE REGION THIS MORNING WITH WDLY SCT
SHRA AND POSSIBLY A TSRA UNTIL THIS DISTURBANCE MOVES EAST BY
MIDDAY. CANNOT TOTALLY RULE OUT ISOLD SHRA/TSRA THIS AFTERNOON BUT
CHANCES LOOK SLIM THROUGH EARLY EVENING. STRONG-SEVERE TSRA
EXPECTED TO DEVELOP OVER CENTRAL/EASTERN IOWA THIS AFTERNOON AND
MOVE QUICKLY EAST ACROSS NORTHERN/CENTRAL ILLINOIS THIS EVENING.
OTHER MINOR CONCERN IS WITH WINDS TODAY. INITIALLY EASTERLY WINDS
SHOULD VEER MORE SOUTHEASTERLY WITH SYNOPTIC GRADIENT FAVORING A
SHIFT TO SOUTH BY MIDDAY...BUT GIVEN THE DECAYING TSRA CLUSTER
UPSTREAM THE WIND FIELD COULD BECOME DISTURBED AND POTENTIALLY
SOMEWHAT ERRATIC FOR A TIME LATER THIS MORNING INTO THE EARLY
AFTERNOON. QUITE POSSIBLE THAT TERMINALS MAY MAINTAIN A MORE
EASTERLY COMPONENT TO THE WINDS INTO THE EARLLY AFTERNOON BEFORE
EVENTUALLY TRANSITIONING TO SOUTH DURING THE AFTERNOON.
IZZI
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* MEDIUM-HIGH CONFIDENCE IN PRECIP TRENDS THRU THIS AFTERNOON.
* LOW CONFIDENCE IN WIND DIRECTION TODAY BUT MAIN COMPONENT IS
SOUTH.
* MEDIUM CONFIDENCE IN TSRA THIS EVENING.
LENNING
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR.
MONDAY...CHANCE OF PM TSRA...OTHERWISE VFR.
TUESDAY THROUGH THURSDAY...VFR.
FRIDAY...CHANCE OF SHRA/TSRA.
IZZI
&&
.MARINE...
229 AM CDT
OUTSIDE OF THUNDERSTORM CHANCES...GENERALLY QUIET WEATHER ON THE
LAKE THROUGH THE WEEKEND WITH SOUTHERLY WINDS DEVELOPING. A COUPLE
OF COLD FRONT WILL MOVE ACROSS THE LAKE...FIRST ONE THIS WEEKEND
WITH WIND SHIFT TO WEST WITH THE SECONDARY...MORE ROBUST...FRONT
MOVING DOWN THE LAKE MONDAY INTO MONDAY NIGHT. COULD SEE A PERIOD
OF SOMEWHAT STRONGER NORTHERLY FLOW WITH THE COLD AIR ADVECTION
MONDAY NIGHT INTO TUESDAY...BUT STILL ONLY LOOKING AT A PERIOD OF
FORCE 3 WINDS FOR THE SOUTHERN PORTIONS OF THE LAKE AS A WORST
CASE SCENARIO. HIGH PRESSURE BUILDS BACK INTO THE REGION WITH
QUIET CONDITIONS AGAIN BY MID WEEK.
IZZI
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS LINCOLN IL
636 AM CDT SAT JUN 15 2013
.DISCUSSION...
ISSUED 243 AM CDT SAT JUN 15 2013
SHORT TERM...TODAY THROUGH MONDAY
07Z IR SATELLITE IMAGERY SHOWS WARMING CLOUD TOPS ASSOCIATED
WITH THE MCS OVER IOWA/NORTHERN MISSOURI. FURTHER DISSIPATION IS
ANTICIPATED AS THE SYSTEM TRACKS E/SE INTO AN INCREASINGLY
UNFAVORABLE AIR MASS EAST OF THE MISSISSIPPI RIVER EARLY THIS
MORNING. BIG QUESTION WILL BE HOW FAR EAST THE PRECIP WILL MAKE
IT BEFORE COMPLETELY DIMINISHING. AS IS TYPICALLY THE CASE WITH
CONVECTION...MOST MODEL GUIDANCE LEAVES A LOT TO BE DESIRED. THE
ONLY MODEL THAT SEEMS TO HAVE A DECENT HANDLE ON THE CURRENT
SITUATION IS THE 05Z HRRR...WHICH BRINGS SHOWERS ACROSS MUCH OF
CENTRAL ILLINOIS THIS MORNING BEFORE FINALLY DISSIPATING THEM
SOUTH OF I-70 TOWARD MIDDAY. GIVEN LATEST SATELLITE/RADAR
TRENDS...THIS SEEMS TO BE A PLAUSIBLE SOLUTION...SO WILL FOLLOW
CLOSELY FOR THE SHORT-TERM. AS A RESULT...WILL CARRY LIKELY POPS
FOR SHOWERS ALONG AND NORTHWEST OF A CHAMPAIGN TO SHELBYVILLE LINE
THROUGH MIDDAY...WITH JUST CHANCE POPS FURTHER E/SE. ONCE THE
DECAYING MCS EXITS INTO INDIANA...THE STABLE AIR MASS LEFT IN ITS
WAKE WILL RESULT IN A LULL IN PRECIP CHANCES FROM LATE MORNING
THROUGH MID-AFTERNOON. HRRR DEPICTS ADDITIONAL CONVECTION FIRING
FURTHER WEST WHERE MUCH GREATER INSTABILITY WILL DEVELOP ACROSS
KANSAS/MISSOURI AFTER 20Z. THINK THIS ACTIVITY WILL GRADUALLY
SPREAD E/NE INTO CENTRAL ILLINOIS LATE THIS AFTERNOON AND EVENING
AHEAD OF AN APPROACHING COLD FRONT. WITH GOOD CONVERGENCE ALONG
THE FRONT...UPPER SUPPORT PROVIDED BY A SIGNIFICANT SHORT-WAVE
TRACKING INTO THE SOUTHERN GREAT LAKES...AND AMPLE MID/LOW-LEVEL
MOISTURE IN PLACE...EXPECT WIDESPREAD SHOWERS/THUNDER ALONG
ADVANCING FRONT. WILL CARRY CATEGORICAL POPS ACROSS ALL BUT THE
FAR SE KILX CWA ACCORDINGLY TONIGHT.
DESPITE QUESTIONABLE CONVECTION FORECASTS IN THE IMMEDIATE
SHORT-TERM...SYNOPTIC MODELS ALL AGREE THAT FRONTAL BOUNDARY WILL
SAG SOUTHWARD THROUGH CENTRAL ILLINOIS ON SUNDAY...SHIFTING THE
GREATEST EMPHASIS FOR ADDITIONAL PRECIP FURTHER SOUTH. WITH WEAK
HIGH PRESSURE BUILDING INTO THE UPPER MIDWEST AND A SLIGHTLY DRIER
AIR MASS TRICKLING SOUTHWARD BEHIND THE BOUNDARY...HAVE REMOVED
MENTIONABLE POPS ACROSS THE NORTHERN CWA ON SUNDAY...THEN ACROSS
THE ENTIRE AREA SUNDAY NIGHT.
ANOTHER SHORT-WAVE TROUGH IS PROGGED TO DIG E/SE ACROSS THE UPPER
MIDWEST INTO THE GREAT LAKES EARLY NEXT WEEK. SYNOPTIC LIFT PROVIDED
BY THIS FEATURE IN CONJUNCTION WITH ANOTHER FRONTAL BOUNDARY IN
THE AREA WILL BE ENOUGH TO TRIGGER SCATTERED SHOWERS/THUNDER ON
MONDAY. FRONT WILL THEN SETTLE FURTHER SOUTHWARD MONDAY
NIGHT...TAKING RAIN CHANCES OUT OF THE AREA OVERNIGHT.
LONG TERM...TUESDAY THROUGH FRIDAY
A RELATIVELY QUIET PERIOD OF WEATHER IS EXPECTED IN THE
EXTENDED...AS A SOMEWHAT COOLER W/NW UPPER FLOW EARLY IN THE
PERIOD IS GRADUALLY REPLACED BY RIDGING BY THE END OF THE WEEK. AS
A RESULT...HIGH TEMPS IN THE UPPER 70S ON TUESDAY WILL WARM INTO
THE MIDDLE TO UPPER 80S BY FRIDAY. MODELS CONTINUE TO SPLASH LIGHT
QPF ACROSS THE AREA FROM TIME TO TIME THROUGHOUT THE
PERIOD...HOWEVER THINK THIS IS WAY OVERDONE. WILL KEEP MENTIONABLE
POPS OUT OF THE FORECAST...UNTIL STRONGER/MORE CONSISTENT SIGNALS
FOR PRECIP DEVELOP.
BARNES
&&
.AVIATION...
ISSUED 635 AM CDT SAT JUN 15 2013
TRICKY TAF FORECAST DUE TO TIMING OF CONVECTIVE REDEVELOPMENT.
EARLIER MCS HAS FADED QUICKLY THE LAST COUPLE HOURS...AND WILL
ONLY SEE A FEW SHOWERS OVER THE TAF SITES THROUGH ABOUT MID
MORNING. CLUSTER OF SHOWERS CURRENTLY IN THE SOUTHEAST TIP OF
IOWA ON TRACK TO REACH KPIA BY 1430Z IF IT HOLDS TOGETHER. THINK
THERE WILL BE A LULL IN THE PRECIP FOR A GOOD PORTION OF THE LATE
MORNING AND EARLY AFTERNOON BEFORE MORE STORMS BEGIN TO REDEVELOP.
MODELS ARE HAVING A HARD TIME AGREEING ON THE LOCATION OF THIS
REDEVELOPMENT...NOT UNUSUAL GIVEN THAT LEFTOVER SUBTLE BOUNDARIES
FROM THE MORNING CONVECTION WILL PLAY A ROLE. THUS...WILL
GENERALLY STICK WITH VCTS MENTION UNTIL MORE CONSISTENT SIGNALS
APPEAR...ALTHOUGH HAVE INCLUDED A FEW HOURS OF TEMPO TSRA PERIODS
LATE AS A FRONTAL BOUNDARY PUSHES THROUGH THE AREA.
GEELHART
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
612 AM CDT SAT JUN 15 2013
.DISCUSSION...
309 AM CDT
MAIN FORECAST CONCERNS THIS MORNING WILL BE DEALING WITH SEVERE
WEATHER CHANCES THIS AFTERNOON/EVENING AND HEAVY RAIN POTENTIAL THIS
EVENING AND TONIGHT.
TODAY AND TONIGHT...
EARLY THIS MORNING A CONVECTIVE COMPLEX IS PUSHING SOUTHEAST ACROSS
NORTHERN MISSOURI THOUGH HAS SHOWN SIGNS OF WEAKENING AS IT MOVES
FROM THE BETTER FORCING ASSOCIATED WITH THE LOW LEVEL JET FOCUSED
OVER CENTRAL IOWA. FARTHER NORTH UNORGANIZED AND WEAKER CONVECTION
SHOULD DIMINISH WITH PERHAPS A FEW LINGERING SHOWERS MOVING INTO THE
AREA THIS MORNING. AN MCV OVER SOUTHEASTERN IOWA WILL MOVE ESE
ACROSS CENTRAL ILLINOIS THIS MORNING AND SHOULD SUPPORT THE GREATEST
POPS OVER THE SOUTHERN CWA //LATEST RAP RUN SEEMS TO HANDLE THIS
FEATURE WELL//. HOW QUICKLY THESE SHOWERS CLEAR OUT AND THE
ASSOCIATED CLOUD COVER...INCLUDING THE CIRRUS CANOPY FROM THE MCS TO
THE SOUTHWEST WILL BE KEY TO BEING ABLE TO RECOVER AND SUPPORT
ADDITIONAL SEVERE WEATHER TODAY. DO EXPECT A LULL IN PRECIP LATE
THIS MORNING THROUGH MID AFTERNOON BETWEEN SYSTEMS.
GUIDANCE SUPPORTS AN AXIS OF MODERATE TO STRONG MLCAPE DEVELOPING
FROM KANSAS NORTHEAST INTO NORTHERN WISCONSIN THIS AFTERNOON WITH
NORTH CENTRAL ILLINOIS ON THE EASTERN PERIPHERY OF THE INSTABILITY.
WHILE INITIALLY CAPPED...A COMPACT WAVE MOVING ACROSS IOWA LATE THIS
AFTERNOON AND EARLY EVENING WILL HELP TO WEAKEN THE CAP ALLOWING FOR
STRONGER SURFACE BASED CONVECTION TO DEVELOP OVER IOWA. DEEP LAYER
SHEAR IS STRONG ENOUGH TO SUPPORT ORGANIZED CONVECTION THIS EVENING
AND COULD SEE THUNDERSTORMS BECOME LINEAR AS THEY MOVE WEST TO EAST
INTO NORTHERN ILLINOIS LATE THIS EVENING. THE SEVERE THREAT SHOULD
DIMINISH THROUGH THE LATE EVENING WITH LOSS OF DAYTIME HEATING...BUT
STRONG MOISTURE TRANSPORT AND PWATS PUSHING TOWARDS THE 2 INCH MARK
TONIGHT WOULD SUGGEST A HEAVY RAIN THREAT INTO THE OVERNIGHT HOURS.
SEVERAL MODELS PRODUCE QFP WELL OVER AN INCH SOMEWHERE ACROSS
NORTHERN ILLINOIS OVERNIGHT...THOUGH STILL CONSIDERABLE UNCERTAINTY
AS TO WHERE EXACTLY THE HEAVY PRECIP AXIS DEVELOPS. THERE IS A
DISTINCT POSSIBILITY THAT THE SOUTHERN HALF OF THE CWA IS FAVORED
DUE TO THE OUTFLOW BOUNDARIES FROM THIS MORNINGS CONVECTION LAYING
OUT ACROSS CENTRAL ILLINOIS TODAY AND SERVING AS THE FOCUS.
SUNDAY THROUGH MONDAY...
A SURFACE LOW WILL TRACK EAST ACROSS THE NORTHERN GREAT LAKES REGION
SUNDAY WITH A COLD FRONT LAYING OUT ACROSS NORTHERN ILLINOIS.
ADDITIONAL THUNDERSTORM CHANCES SHOULD GENERALLY BE ALONG AND OUT
AHEAD OF THE COLD FRONT AS IT SAGS SOUTH ACROSS THE CWA THROUGH THE
DAY AND MUCH DRIER MID LEVEL AIR FILTERS SOUTH. NOT MUCH COLD AIR
ASSOCIATED WITH THE FRONT AND SKIES CLEARING BEHIND SHOULD HELP
ALLOW TEMPS TO RISE INTO THE LOW TO MID 80S SUNDAY. SECONDARY
TROUGH/FRONT WILL SINK SOUTH ACROSS THE AREA WITH THE POTENTIAL FOR
ADDITIONAL THUNDERSTORMS MONDAY. GFS AT THIS POINT IS HAVING GROWING
ISSUES WITH CONVECTIVE FEEDBACK DEVELOPING A DEEP LOW OVER THE
PLAINS...THUS LEANED TOWARDS A BLEND OF NON-GFS SOLUTIONS WHICH
LOWERS POPS ACROSS THE CWA ON MONDAY.
TUESDAY THROUGH THURSDAY...
PERIOD WILL BE DOMINATED BY HIGH PRESSURE AND DRY CONDITIONS.
TEMPERATURES WILL MODERATE THROUGH THE PERIOD WITH TEMPS ONLY IN THE
70S TUESDAY WARMING INTO THE LOW 80S THURSDAY. LAKE BREEZES ARE
EXPECTED EACH DAY WHICH WILL KEEP TEMPS QUITE A BIT COOLER ALONG THE
LAKE FRONT.
DEUBELBEISS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* ISOLD SHRA/SLIGHT CHANCE OF TSRA THIS MORNING
* BETTER CHANCE OF TSRA...POSSIBLY STRONG...MOVE IN THIS EVENING
IZZI
//DISCUSSION...UPDATED 12Z...
WEAKENING CLUSTER OF STORMS WITH ASSOCIATED UPPER LEVEL
DISTURBANCE WILL MOVE ACROSS THE REGION THIS MORNING WITH WDLY SCT
SHRA AND POSSIBLY A TSRA UNTIL THIS DISTURBANCE MOVES EAST BY
MIDDAY. CANNOT TOTALLY RULE OUT ISOLD SHRA/TSRA THIS AFTERNOON BUT
CHANCES LOOK SLIM THROUGH EARLY EVENING. STRONG-SEVERE TSRA
EXPECTED TO DEVELOP OVER CENTRAL/EASTERN IOWA THIS AFTERNOON AND
MOVE QUICKLY EAST ACROSS NORTHERN/CENTRAL ILLINOIS THIS EVENING.
OTHER MINOR CONCERN IS WITH WINDS TODAY. INITIALLY EASTERLY WINDS
SHOULD VEER MORE SOUTHEASTERLY WITH SYNOPTIC GRADIENT FAVORING A
SHIFT TO SOUTH BY MIDDAY...BUT GIVEN THE DECAYING TSRA CLUSTER
UPSTREAM THE WIND FIELD COULD BECOME DISTURBED AND POTENTIALLY
SOMEWHAT ERRATIC FOR A TIME LATER THIS MORNING INTO THE EARLY
AFTERNOON. QUITE POSSIBLE THAT TERMINALS MAY MAINTAIN A MORE
EASTERLY COMPONENT TO THE WINDS INTO THE EARLLY AFTERNOON BEFORE
EVENTUALLY TRANSITIONING TO SOUTH DURING THE AFTERNOON.
IZZI
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* MEDIUM-HIGH CONFIDENCE IN PRECIP TRENDS THRU THIS AFTERNOON
* LOW CONFIDENCE IN WIND DIRECTION TODAY
* MEDIUM CONFIDENCE IN TSRA THIS EVENING
IZZI
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR.
MONDAY...CHANCE OF PM TSRA...OTHERWISE VFR.
TUESDAY THROUGH THURSDAY...VFR.
FRIDAY...CHANCE OF SHRA/TSRA.
IZZI
&&
.MARINE...
229 AM CDT
OUTSIDE OF THUNDERSTORM CHANCES...GENERALLY QUIET WEATHER ON THE
LAKE THROUGH THE WEEKEND WITH SOUTHERLY WINDS DEVELOPING. A COUPLE
OF COLD FRONT WILL MOVE ACROSS THE LAKE...FIRST ONE THIS WEEKEND
WITH WIND SHIFT TO WEST WITH THE SECONDARY...MORE ROBUST...FRONT
MOVING DOWN THE LAKE MONDAY INTO MONDAY NIGHT. COULD SEE A PERIOD
OF SOMEWHAT STRONGER NORTHERLY FLOW WITH THE COLD AIR ADVECTION
MONDAY NIGHT INTO TUESDAY...BUT STILL ONLY LOOKING AT A PERIOD OF
FORCE 3 WINDS FOR THE SOUTHERN PORTIONS OF THE LAKE AS A WORST
CASE SCENARIO. HIGH PRESSURE BUILDS BACK INTO THE REGION WITH
QUIET CONDITIONS AGAIN BY MID WEEK.
IZZI
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
433 AM CDT SAT JUN 15 2013
.DISCUSSION...
309 AM CDT
MAIN FORECAST CONCERNS THIS MORNING WILL BE DEALING WITH SEVERE
WEATHER CHANCES THIS AFTERNOON/EVENING AND HEAVY RAIN POTENTIAL THIS
EVENING AND TONIGHT.
TODAY AND TONIGHT...
EARLY THIS MORNING A CONVECTIVE COMPLEX IS PUSHING SOUTHEAST ACROSS
NORTHERN MISSOURI THOUGH HAS SHOWN SIGNS OF WEAKENING AS IT MOVES
FROM THE BETTER FORCING ASSOCIATED WITH THE LOW LEVEL JET FOCUSED
OVER CENTRAL IOWA. FARTHER NORTH UNORGANIZED AND WEAKER CONVECTION
SHOULD DIMINISH WITH PERHAPS A FEW LINGERING SHOWERS MOVING INTO THE
AREA THIS MORNING. AN MCV OVER SOUTHEASTERN IOWA WILL MOVE ESE
ACROSS CENTRAL ILLINOIS THIS MORNING AND SHOULD SUPPORT THE GREATEST
POPS OVER THE SOUTHERN CWA //LATEST RAP RUN SEEMS TO HANDLE THIS
FEATURE WELL//. HOW QUICKLY THESE SHOWERS CLEAR OUT AND THE
ASSOCIATED CLOUD COVER...INCLUDING THE CIRRUS CANOPY FROM THE MCS TO
THE SOUTHWEST WILL BE KEY TO BEING ABLE TO RECOVER AND SUPPORT
ADDITIONAL SEVERE WEATHER TODAY. DO EXPECT A LULL IN PRECIP LATE
THIS MORNING THROUGH MID AFTERNOON BETWEEN SYSTEMS.
GUIDANCE SUPPORTS AN AXIS OF MODERATE TO STRONG MLCAPE DEVELOPING
FROM KANSAS NORTHEAST INTO NORTHERN WISCONSIN THIS AFTERNOON WITH
NORTH CENTRAL ILLINOIS ON THE EASTERN PERIPHERY OF THE INSTABILITY.
WHILE INITIALLY CAPPED...A COMPACT WAVE MOVING ACROSS IOWA LATE THIS
AFTERNOON AND EARLY EVENING WILL HELP TO WEAKEN THE CAP ALLOWING FOR
STRONGER SURFACE BASED CONVECTION TO DEVELOP OVER IOWA. DEEP LAYER
SHEAR IS STRONG ENOUGH TO SUPPORT ORGANIZED CONVECTION THIS EVENING
AND COULD SEE THUNDERSTORMS BECOME LINEAR AS THEY MOVE WEST TO EAST
INTO NORTHERN ILLINOIS LATE THIS EVENING. THE SEVERE THREAT SHOULD
DIMINISH THROUGH THE LATE EVENING WITH LOSS OF DAYTIME HEATING...BUT
STRONG MOISTURE TRANSPORT AND PWATS PUSHING TOWARDS THE 2 INCH MARK
TONIGHT WOULD SUGGEST A HEAVY RAIN THREAT INTO THE OVERNIGHT HOURS.
SEVERAL MODELS PRODUCE QFP WELL OVER AN INCH SOMEWHERE ACROSS
NORTHERN ILLINOIS OVERNIGHT...THOUGH STILL CONSIDERABLE UNCERTAINTY
AS TO WHERE EXACTLY THE HEAVY PRECIP AXIS DEVELOPS. THERE IS A
DISTINCT POSSIBILITY THAT THE SOUTHERN HALF OF THE CWA IS FAVORED
DUE TO THE OUTFLOW BOUNDARIES FROM THIS MORNINGS CONVECTION LAYING
OUT ACROSS CENTRAL ILLINOIS TODAY AND SERVING AS THE FOCUS.
SUNDAY THROUGH MONDAY...
A SURFACE LOW WILL TRACK EAST ACROSS THE NORTHERN GREAT LAKES REGION
SUNDAY WITH A COLD FRONT LAYING OUT ACROSS NORTHERN ILLINOIS.
ADDITIONAL THUNDERSTORM CHANCES SHOULD GENERALLY BE ALONG AND OUT
AHEAD OF THE COLD FRONT AS IT SAGS SOUTH ACROSS THE CWA THROUGH THE
DAY AND MUCH DRIER MID LEVEL AIR FILTERS SOUTH. NOT MUCH COLD AIR
ASSOCIATED WITH THE FRONT AND SKIES CLEARING BEHIND SHOULD HELP
ALLOW TEMPS TO RISE INTO THE LOW TO MID 80S SUNDAY. SECONDARY
TROUGH/FRONT WILL SINK SOUTH ACROSS THE AREA WITH THE POTENTIAL FOR
ADDITIONAL THUNDERSTORMS MONDAY. GFS AT THIS POINT IS HAVING GROWING
ISSUES WITH CONVECTIVE FEEDBACK DEVELOPING A DEEP LOW OVER THE
PLAINS...THUS LEANED TOWARDS A BLEND OF NON-GFS SOLUTIONS WHICH
LOWERS POPS ACROSS THE CWA ON MONDAY.
TUESDAY THROUGH THURSDAY...
PERIOD WILL BE DOMINATED BY HIGH PRESSURE AND DRY CONDITIONS.
TEMPERATURES WILL MODERATE THROUGH THE PERIOD WITH TEMPS ONLY IN THE
70S TUESDAY WARMING INTO THE LOW 80S THURSDAY. LAKE BREEZES ARE
EXPECTED EACH DAY WHICH WILL KEEP TEMPS QUITE A BIT COOLER ALONG THE
LAKE FRONT.
DEUBELBEISS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* SCTD SHRA AND SLIGHT CHANCE OF TSRA THROUGH MID/LATE MORNING
* ADDITIONAL TSRA LIKELY SATURDAY EVENING...POSSIBLY STRONG
IZZI
//DISCUSSION...UPDATED 09Z...
CLUSTER OF SHRA/TSRA OVER IA WEAKENING AS EXPECTED...THOUGH A BIT
MORE QUICKLY THAN EARLIER THOUGHT. SOME SCTD SHRA/ISOLD TSRA
CONTINUE TO FLARE UP ACROSS THE REGION AND UNTIL THIS UPPER
DISTURBANCE MOVES EAST OF THE REGION LATER THIS MORNING WDLY SCTD
SHRA/ISOLD TSRA WILL REMAIN A THREAT. MAJORITY OF THIS MORNING
WILL BE DRY SO WILL HANDLE PRECIP THREAT THIS MORNING WITH A VCSH
THOUGH ITS PRETTY LIKELY AT LEAST A COUPLE BRIEF SHOWERS AND
POSSIBLY A BRIEF TSRA COULD IMPACT THE TERMINALS ANYTIME BETWEEN
NOW AND THE 15-17Z TIME FRAME.
IZZI
UPDATED 06Z...
LARGE CLUSTER OF SHRA/TSRA OVER IA WILL CONTINUE MOVING EASTWARD
TOWARD N IL...THOUGH EXPECT TSRA COVERAGE WILL DECREASE AS IT
MOVES INTO IL INTO MORE STABLE ENVIRONMENT. STILL SEEMS PLAUSIBLE
THAT THERE WILL BE SOME SCTD SHRA AROUND MID/LATE MORNING WITH A
LOW END THREAT OF AN ISOLD TSRA. IN THE WAKE OF THIS CLUSTER
ANTICIPATE PERIOD OF DRY AND STABLE CONDITIONS THIS AFTERNOON
AND PROBABLY LINGERING INTO EARLY EVENING WITH VFR CONDITIONS.
ANOTHER STRONGER UPPER DISTURBANCE WILL MOVE INTO THE CORN BELT
THIS AFTERNOON AND LIKELY RESULT IN INTENSE THUNDERSTORMS
DEVELOPING OVER CENTRAL/EASTERN IOWA LATER THIS AFTERNOON...WITH
THESE STORMS LIKELY TO CONSOLIDATE INTO A CLUSTER OF STRONG TO
SEVERE TSRA AND MOVE EASTWARD ACROSS NORTHERN ILLINOIS THIS
EVENING. USUAL UNCERTAINTIES EXISTS WITH TIMING AND PLACEMENT OF
TSRA THIS AFTERNOON AND EVENING...SO FORECAST IS BASED ON WHAT
APPEARS TO BE MOST PROBABLE SCENARIO AT THIS TIME...BUT MAY NEED
TO BE REFINED TODAY AS MESOSCALE TRENDS BECOME MORE APPARENT.
OTHER MORE MINOR CONCERN IS WITH WINDS THROUGH THE PERIOD.
INITIALLY EASTERLY WINDS SHOULD VEER MORE SOUTHEASTERLY THIS
MORNING. SYNOPTIC GRADIENT FAVORS A SHIFT TO SOUTH BY LATER THIS
MORNING...BUT GIVEN THE WELL DEVELOP TSRA CLUSTER UPSTREAM THE
WIND FIELD COULD BECOME DISTURBED AND POTENTIALLY SOMEWHAT ERRATIC
FOR A TIME LATER THIS MORNING INTO THE EARLY AFTERNOON. QUITE
POSSIBLE THAT TERMINALS MAY MAINTAIN A MORE EASTERLY COMPONENT TO
THE WINDS INTO THE AFTERNOON BEFORE EVENTUALLY TRANSITIONING TO
SOUTH BY MID/LATE AFTERNOON.
IZZI
//ORD AND MDW CONFIDENCE...UPDATED 09Z...
* MEDIUM CONFIDENCE IN SCTD SHRA MID/LATE MORNING WITH LOW
CONFIDENCE IN TSRA
* MEDIUM-HIGH CONFIDENCE IN MAINLY DRY CONDITIONS THIS AFTERNOON
INTO VERY EARLY EVENING
* LOW/MEDIUM CONFIDENCE IN WIND DIRECTION LATER THIS MORNING INTO
THE EARLY AFTERNOON
* MEDIUM CONFIDENCE IN PERIOD OF TSRA THIS EVENING...LOW
CONFIDENCE IN PRECISE TIMING
IZZI
//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...
SUN...VFR. SLGT CHC TSRA DURG DAYTIME.
MON...VFR. CHC TSRA DURG DAY...SLGT CHC SHRA DURG NIGHT.
TUE THRU THU...VFR. NO SIG WX.
TRS
&&
.MARINE...
229 AM CDT
OUTSIDE OF THUNDERSTORM CHANCES...GENERALLY QUIET WEATHER ON THE
LAKE THROUGH THE WEEKEND WITH SOUTHERLY WINDS DEVELOPING. A COUPLE
OF COLD FRONT WILL MOVE ACROSS THE LAKE...FIRST ONE THIS WEEKEND
WITH WIND SHIFT TO WEST WITH THE SECONDARY...MORE ROBUST...FRONT
MOVING DOWN THE LAKE MONDAY INTO MONDAY NIGHT. COULD SEE A PERIOD
OF SOMEWHAT STRONGER NORTHERLY FLOW WITH THE COLD AIR ADVECTION
MONDAY NIGHT INTO TUESDAY...BUT STILL ONLY LOOKING AT A PERIOD OF
FORCE 3 WINDS FOR THE SOUTHERN PORTIONS OF THE LAKE AS A WORST
CASE SCENARIO. HIGH PRESSURE BUILDS BACK INTO THE REGION WITH
QUIET CONDITIONS AGAIN BY MID WEEK.
IZZI
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
310 AM CDT SAT JUN 15 2013
.DISCUSSION...
309 AM CDT
MAIN FORECAST CONCERNS THIS MORNING WILL BE DEALING WITH SEVERE
WEATHER CHANCES THIS AFTERNOON/EVENING AND HEAVY RAIN POTENTIAL THIS
EVENING AND TONIGHT.
TODAY AND TONIGHT...
EARLY THIS MORNING A CONVECTIVE COMPLEX IS PUSHING SOUTHEAST ACROSS
NORTHERN MISSOURI THOUGH HAS SHOWN SIGNS OF WEAKENING AS IT MOVES
FROM THE BETTER FORCING ASSOCIATED WITH THE LOW LEVEL JET FOCUSED
OVER CENTRAL IOWA. FARTHER NORTH UNORGANIZED AND WEAKER CONVECTION
SHOULD DIMINISH WITH PERHAPS A FEW LINGERING SHOWERS MOVING INTO THE
AREA THIS MORNING. AN MCV OVER SOUTHEASTERN IOWA WILL MOVE ESE
ACROSS CENTRAL ILLINOIS THIS MORNING AND SHOULD SUPPORT THE GREATEST
POPS OVER THE SOUTHERN CWA //LATEST RAP RUN SEEMS TO HANDLE THIS
FEATURE WELL//. HOW QUICKLY THESE SHOWERS CLEAR OUT AND THE
ASSOCIATED CLOUD COVER...INCLUDING THE CIRRUS CANOPY FROM THE MCS TO
THE SOUTHWEST WILL BE KEY TO BEING ABLE TO RECOVER AND SUPPORT
ADDITIONAL SEVERE WEATHER TODAY. DO EXPECT A LULL IN PRECIP LATE
THIS MORNING THROUGH MID AFTERNOON BETWEEN SYSTEMS.
GUIDANCE SUPPORTS AN AXIS OF MODERATE TO STRONG MLCAPE DEVELOPING
FROM KANSAS NORTHEAST INTO NORTHERN WISCONSIN THIS AFTERNOON WITH
NORTH CENTRAL ILLINOIS ON THE EASTERN PERIPHERY OF THE INSTABILITY.
WHILE INITIALLY CAPPED...A COMPACT WAVE MOVING ACROSS IOWA LATE THIS
AFTERNOON AND EARLY EVENING WILL HELP TO WEAKEN THE CAP ALLOWING FOR
STRONGER SURFACE BASED CONVECTION TO DEVELOP OVER IOWA. DEEP LAYER
SHEAR IS STRONG ENOUGH TO SUPPORT ORGANIZED CONVECTION THIS EVENING
AND COULD SEE THUNDERSTORMS BECOME LINEAR AS THEY MOVE WEST TO EAST
INTO NORTHERN ILLINOIS LATE THIS EVENING. THE SEVERE THREAT SHOULD
DIMINISH THROUGH THE LATE EVENING WITH LOSS OF DAYTIME HEATING...BUT
STRONG MOISTURE TRANSPORT AND PWATS PUSHING TOWARDS THE 2 INCH MARK
TONIGHT WOULD SUGGEST A HEAVY RAIN THREAT INTO THE OVERNIGHT HOURS.
SEVERAL MODELS PRODUCE QFP WELL OVER AN INCH SOMEWHERE ACROSS
NORTHERN ILLINOIS OVERNIGHT...THOUGH STILL CONSIDERABLE UNCERTAINTY
AS TO WHERE EXACTLY THE HEAVY PRECIP AXIS DEVELOPS. THERE IS A
DISTINCT POSSIBILITY THAT THE SOUTHERN HALF OF THE CWA IS FAVORED
DUE TO THE OUTFLOW BOUNDARIES FROM THIS MORNINGS CONVECTION LAYING
OUT ACROSS CENTRAL ILLINOIS TODAY AND SERVING AS THE FOCUS.
SUNDAY THROUGH MONDAY...
A SURFACE LOW WILL TRACK EAST ACROSS THE NORTHERN GREAT LAKES REGION
SUNDAY WITH A COLD FRONT LAYING OUT ACROSS NORTHERN ILLINOIS.
ADDITIONAL THUNDERSTORM CHANCES SHOULD GENERALLY BE ALONG AND OUT
AHEAD OF THE COLD FRONT AS IT SAGS SOUTH ACROSS THE CWA THROUGH THE
DAY AND MUCH DRIER MID LEVEL AIR FILTERS SOUTH. NOT MUCH COLD AIR
ASSOCIATED WITH THE FRONT AND SKIES CLEARING BEHIND SHOULD HELP
ALLOW TEMPS TO RISE INTO THE LOW TO MID 80S SUNDAY. SECONDARY
TROUGH/FRONT WILL SINK SOUTH ACROSS THE AREA WITH THE POTENTIAL FOR
ADDITIONAL THUNDERSTORMS MONDAY. GFS AT THIS POINT IS HAVING GROWING
ISSUES WITH CONVECTIVE FEEDBACK DEVELOPING A DEEP LOW OVER THE
PLAINS...THUS LEANED TOWARDS A BLEND OF NON-GFS SOLUTIONS WHICH
LOWERS POPS ACROSS THE CWA ON MONDAY.
TUESDAY THROUGH THURSDAY...
PERIOD WILL BE DOMINATED BY HIGH PRESSURE AND DRY CONDITIONS.
TEMPERATURES WILL MODERATE THROUGH THE PERIOD WITH TEMPS ONLY IN THE
70S TUESDAY WARMING INTO THE LOW 80S THURSDAY. LAKE BREEZES ARE
EXPECTED EACH DAY WHICH WILL KEEP TEMPS QUITE A BIT COOLER ALONG THE
LAKE FRONT.
DEUBELBEISS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* SCTD SHRA AND SLIGHT CHANCE OF TSRA MID/LATE MORNING
* ADDITIONAL TSRA LIKELY SATURDAY EVENING
IZZI
//DISCUSSION...UPDATED 06Z...
LARGE CLUSTER OF SHRA/TSRA OVER IA WILL CONTINUE MOVING EASTWARD
TOWARD N IL...THOUGH EXPECT TSRA COVERAGE WILL DECREASE AS IT
MOVES INTO IL INTO MORE STABLE ENVIRONMENT. STILL SEEMS PLAUSIBLE
THAT THERE WILL BE SOME SCTD SHRA AROUND MID/LATE MORNING WITH A
LOW END THREAT OF AN ISOLD TSRA. IN THE WAKE OF THIS CLUSTER
ANTICIPATE PERIOD OF DRY AND STABLE CONDITIONS THIS AFTERNOON
AND PROBABLY LINGERING INTO EARLY EVENING WITH VFR CONDITIONS.
ANOTHER STRONGER UPPER DISTURBANCE WILL MOVE INTO THE CORN BELT
THIS AFTERNOON AND LIKELY RESULT IN INTENSE THUNDERSTORMS
DEVELOPING OVER CENTRAL/EASTERN IOWA LATER THIS AFTERNOON...WITH
THESE STORMS LIKELY TO CONSOLIDATE INTO A CLUSTER OF STRONG TO
SEVERE TSRA AND MOVE EASTWARD ACROSS NORTHERN ILLINOIS THIS
EVENING. USUAL UNCERTAINTIES EXISTS WITH TIMING AND PLACEMENT OF
TSRA THIS AFTERNOON AND EVENING...SO FORECAST IS BASED ON WHAT
APPEARS TO BE MOST PROBABLE SCENARIO AT THIS TIME...BUT MAY NEED
TO BE REFINED TODAY AS MESOSCALE TRENDS BECOME MORE APPARENT.
OTHER MORE MINOR CONCERN IS WITH WINDS THROUGH THE PERIOD.
INITIALLY EASTERLY WINDS SHOULD VEER MORE SOUTHEASTERLY THIS
MORNING. SYNOPTIC GRADIENT FAVORS A SHIFT TO SOUTH BY LATER THIS
MORNING...BUT GIVEN THE WELL DEVELOP TSRA CLUSTER UPSTREAM THE
WIND FIELD COULD BECOME DISTURBED AND POTENTIALLY SOMEWHAT ERRATIC
FOR A TIME LATER THIS MORNING INTO THE EARLY AFTERNOON. QUITE
POSSIBLE THAT TERMINALS MAY MAINTAIN A MORE EASTERLY COMPONENT TO
THE WINDS INTO THE AFTERNOON BEFORE EVENTUALLY TRANSITIONING TO
SOUTH BY MID/LATE AFTERNOON.
IZZI
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM CONFIDENCE IN SCTD SHRA MID/LATE MORNING WITH LOW
CONFIDENCE IN TSRA
* MEDIUM CONFIDENCE IN MAINLY DRY CONDITIONS THIS AFTERNOON INTO
EARLY EVENING
* LOW/MEDIUM CONFIDENCE IN WIND DIRECTION LATER THIS MORNING INTO
THE EARLY AFTERNOON
* MEDIUM CONFIDENCE IN PERIOD OF TSRA THIS EVENING...LOW
CONFIDENCE IN PRECISE TIMING
IZZI
//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...
SUN...VFR. SLGT CHC TSRA DURG DAYTIME.
MON...VFR. CHC TSRA DURG DAY...SLGT CHC SHRA DURG NIGHT.
TUE THRU THU...VFR. NO SIG WX.
TRS
&&
.MARINE...
229 AM CDT
OUTSIDE OF THUNDERSTORM CHANCES...GENERALLY QUIET WEATHER ON THE
LAKE THROUGH THE WEEKEND WITH SOUTHERLY WINDS DEVELOPING. A COUPLE
OF COLD FRONT WILL MOVE ACROSS THE LAKE...FIRST ONE THIS WEEKEND
WITH WIND SHIFT TO WEST WITH THE SECONDARY...MORE ROBUST...FRONT
MOVING DOWN THE LAKE MONDAY INTO MONDAY NIGHT. COULD SEE A PERIOD
OF SOMEWHAT STRONGER NORTHERLY FLOW WITH THE COLD AIR ADVECTION
MONDAY NIGHT INTO TUESDAY...BUT STILL ONLY LOOKING AT A PERIOD OF
FORCE 3 WINDS FOR THE SOUTHERN PORTIONS OF THE LAKE AS A WORST
CASE SCENARIO. HIGH PRESSURE BUILDS BACK INTO THE REGION WITH
QUIET CONDITIONS AGAIN BY MID WEEK.
IZZI
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS LINCOLN IL
244 AM CDT SAT JUN 15 2013
.DISCUSSION...
ISSUED 243 AM CDT SAT JUN 15 2013
SHORT TERM...TODAY THROUGH MONDAY
07Z IR SATELLITE IMAGERY SHOWS WARMING CLOUD TOPS ASSOCIATED
WITH THE MCS OVER IOWA/NORTHERN MISSOURI. FURTHER DISSIPATION IS
ANTICIPATED AS THE SYSTEM TRACKS E/SE INTO AN INCREASINGLY
UNFAVORABLE AIRMASS EAST OF THE MISSISSIPPI RIVER EARLY THIS
MORNING. BIG QUESTION WILL BE HOW FAR EAST THE PRECIP WILL MAKE
IT BEFORE COMPLETELY DIMINISHING. AS IS TYPICALLY THE CASE WITH
CONVECTION...MOST MODEL GUIDANCE LEAVES A LOT TO BE DESIRED. THE
ONLY MODEL THAT SEEMS TO HAVE A DECENT HANDLE ON THE CURRENT
SITUATION IS THE 05Z HRRR...WHICH BRINGS SHOWERS ACROSS MUCH OF
CENTRAL ILLINOIS THIS MORNING BEFORE FINALLY DISSIPATING THEM
SOUTH OF I-70 TOWARD MIDDAY. GIVEN LATEST SATELLITE/RADAR
TRENDS...THIS SEEMS TO BE A PLAUSIBLE SOLUTION...SO WILL FOLLOW
CLOSELY FOR THE SHORT-TERM. AS A RESULT...WILL CARRY LIKELY POPS
FOR SHOWERS ALONG AND NORTHWEST OF A CHAMPAIGN TO SHELBYVILLE LINE
THROUGH MIDDAY...WITH JUST CHANCE POPS FURTHER E/SE. ONCE THE
DECAYING MCS EXITS INTO INDIANA...THE STABLE AIRMASS LEFT IN ITS
WAKE WILL RESULT IN A LULL IN PRECIP CHANCES FROM LATE MORNING
THROUGH MID-AFTERNOON. HRRR DEPICTS ADDITIONAL CONVECTION FIRING
FURTHER WEST WHERE MUCH GREATER INSTABILITY WILL DEVELOP ACROSS
KANSAS/MISSOURI AFTER 20Z. THINK THIS ACTIVITY WILL GRADUALLY
SPREAD E/NE INTO CENTRAL ILLINOIS LATE THIS AFTERNOON AND EVENING
AHEAD OF AN APPROACHING COLD FRONT. WITH GOOD CONVERGENCE ALONG
THE FRONT...UPPER SUPPORT PROVIDED BY A SIGNIFICANT SHORT-WAVE
TRACKING INTO THE SOUTHERN GREAT LAKES...AND AMPLE MID/LOW-LEVEL
MOISTURE IN PLACE...EXPECT WIDESPREAD SHOWERS/THUNDER ALONG
ADVANCING FRONT. WILL CARRY CATEGORICAL POPS ACROSS ALL BUT THE
FAR SE KILX CWA ACCORDINGLY TONIGHT.
DESPITE QUESTIONABLE CONVECTION FORECASTS IN THE IMMEDIATE
SHORT-TERM...SYNOPTIC MODELS ALL AGREE THAT FRONTAL BOUNDARY WILL
SAG SOUTHWARD THROUGH CENTRAL ILLINOIS ON SUNDAY...SHIFTING THE
GREATEST EMPHASIS FOR ADDITIONAL PRECIP FURTHER SOUTH. WITH WEAK
HIGH PRESSURE BUILDING INTO THE UPPER MIDWEST AND A SLIGHTLY DRIER
AIRMASS TRICKLING SOUTHWARD BEHIND THE BOUNDARY...HAVE REMOVED
MENTIONABLE POPS ACROSS THE NORTHERN CWA ON SUNDAY...THEN ACROSS
THE ENTIRE AREA SUNDAY NIGHT.
ANOTHER SHORT-WAVE TROUGH IS PROGGED TO DIG E/SE ACROSS THE UPPER
MIDWEST INTO THE GREAT LAKES EARLY NEXT WEEK. SYNOPTIC LIFT PROVIDED
BY THIS FEATURE IN CONJUNCTION WITH ANOTHER FRONTAL BOUNDARY IN
THE AREA WILL BE ENOUGH TO TRIGGER SCATTERED SHOWERS/THUNDER ON
MONDAY. FRONT WILL THEN SETTLE FURTHER SOUTHWARD MONDAY
NIGHT...TAKING RAIN CHANCES OUT OF THE AREA OVERNIGHT.
LONG TERM...TUESDAY THROUGH FRIDAY
A RELATIVELY QUIET PERIOD OF WEATHER IS EXPECTED IN THE
EXTENDED...AS A SOMEWHAT COOLER W/NW UPPER FLOW EARLY IN THE
PERIOD IS GRADUALLY REPLACED BY RIDGING BY THE END OF THE WEEK. AS
A RESULT...HIGH TEMPS IN THE UPPER 70S ON TUESDAY WILL WARM INTO
THE MIDDLE TO UPPER 80S BY FRIDAY. MODELS CONTINUE TO SPLASH LIGHT
QPF ACROSS THE AREA FROM TIME TO TIME THROUGHOUT THE
PERIOD...HOWEVER THINK THIS IS WAY OVERDONE. WILL KEEP MENTIONABLE
POPS OUT OF THE FORECAST...UNTIL STRONGER/MORE CONSISTENT SIGNALS
FOR PRECIP DEVELOP.
BARNES
&&
.AVIATION...
ISSUED 1204 AM CDT SAT JUN 15 2013
MODELS HAVING DIFFICULTY WITH EVOLUTION OF THUNDERSTORMS THROUGH
THE MORNING...AS WELL AS INTO THE AFTERNOON WITH REFIRING OF
CONVECTION ALONG THE REMNANTS OF TONIGHTS MCS. AS A RESULT...MANY
VCTS MENTIONS. BEST TS THREAT WARRANTING A TEMPO...LATER THIS
MORNING IN PIA...CLOSER TO THE MORE SATURATED AIR AS A RESULT OF
MOISTURE ADVECTION DUE TO CONVECTION TO THE WEST. FOR
TOMORROW...REFIRE OF CONVECTION WITH DIURNAL HEATING AND TERMINALS
CLOSER TO THE APPROACHING WAVE...PIA BMI AND SPI WITH A TEMPO FROM
21-24Z. OUTSIDE OF CONVECTIVE ACTIVITY...VFR CONDITIONS WITH
INCREASINGLY SOUTHERLY WINDS AS THE RIDGE AXIS SHIFTS EASTWARD.
HJS
&&
.PREV DISCUSSION...
ISSUED 302 PM CDT FRI JUN 14 2013
MAIN CONCERN DURING THIS FORECAST PACKAGE REMAINS THE
CHANCES OF PCPN FOR TONIGHT THROUGH MONDAY. MODELS REMAIN IN GOOD
AGREEMENT WITH OVERALL UPPER LEVEL PATTERN NEXT 3-5 DAYS BUT THEN
BEGIN TO DIFFER SOME IN THE EXTENDED PERIODS FOR NEXT WEEK. ON THE
SFC HOWEVER...THINGS ARE A LITTLE DIFFERENT. EXTENDED MODELS LOOK
OK THROUGH ABOUT 48HRS BUT THEN BEGIN TO LOOK MESSY/UNSURE OF
THEMSELVES AS TO WHAT THE PRESSURE FIELDS ARE GOING TO LOOK LIKE
BEYOND SUNDAY. SO A BLEND OF MODELS FOR THE FORECAST LOOKS OK
THROUGH ABOUT 48HRS AND THEN AGAIN FOR NEXT WEEK. IN BETWEEN THOSE
TIMES...WILL JUST GO WITH PERSISTENCE AND HOPE THE MODELS WILL
WORK OUT DIFFERENCES ONCE THOSE TIME FRAMES GET CLOSER.
SHORT TERM...TONIGHT THROUGH MONDAY
MODELS SEEM TO INDICATE A SERIES OF THUNDERSTORMS COMPLEXES
POSSIBLE THE NEXT TWO NIGHTS...POSSIBLY THREE. CURRENT CONVECTION
NORTHWEST OF THE AREA WILL CONTINUE TO DIMINISH AS IT MOVES
SOUTHEAST AWAY FROM THE BEST SUPPORT AND MOISTURE. HOWEVER...AS
THE LOW LEVEL JET BECOMES MORE FOCUSED BACK OUT IN THE PLAINS
TONIGHT AN MCS IS EXPECTED TO DEVELOP NORTHWEST OF THE AREA AND
THEN MOVE EAST-SOUTHEAST TOWARD THE CWA OVERNIGHT. WILL HAVE
LINGERING PCPN CHANCES IN THE WEST THIS EVENING...BUT THEN SHIFT
THE FOCUS TO THE NORTHWEST FOR THE REMAINDER OF THE NIGHT...WITH
HIGHEST POPS AFTER 06Z-09Z IN THE NORTHWEST AND WEST. OUTFLOW
BOUNDARIES FROM THIS COMPLEX OF STORMS WILL BECOME THE FOCUS FOR
MORE THUNDERSTORMS TOMORROW LATE MORNING INTO TOMORROW AFTERNOON
AND PROBABLY CONTINUING INTO TOMORROW NIGHT. SO POPS WILL BECOME
LIKELY ACROSS THE WHOLE AREA TOMORROW AFTERNOON THROUGH TOMORROW
NIGHT.
ANOTHER MCS IS POSSIBLE TO THE WEST OF THE AREA...MOVING EAST INTO
THE AREA TOMORROW NIGHT INTO SUNDAY MORNING. POPS WILL REMAIN
LIKELY THROUGH SUNDAY IN THE CENTRAL AND SOUTH BUT THERE WILL
LIKELY BE SOME PERIODS WHERE THERE WILL BE BREAKS BETWEEN THE PCPN
ENDING AND THEN STARTING AGAIN. IN THESE SITUATIONS...TIMING OF
THESE BREAKS DEPENDS ON THE MICRO-SCALE FEATURES...WHICH SYNOPTIC
MODELS HAVE DIFFICULTY PICKING UP PAST 24HRS. SO WILL WAIT TIL
TOMORROW AND LATE TO FINE TUNE OTHER PERIODS BEYOND TOMORROW.
THOUGH MODELS SHOW A BREAK IN THE PCPN FOR SUNDAY NIGHT...STILL
SOME UNCERTAINTY. SO WILL PUSH POPS DOWN INTO THE CHC CATEGORY FOR
NOW AND WAIT TIL LATE TO SEE WHAT THE REAL STORY COULD BE. PCPN
SHOULD CONTINUE INTO MONDAY...BUT AGAIN...MODELS DIFFER ON WHO
THIS WILL LOOK SO WILL JUST KEEP CHC POPS THERE TOO.
HIGH TEMPS WILL WARM SLIGHTLY BUT STILL REMAIN AT OR JUST ABOVE
NORMAL...IN THE LOWER TO MIDDLE 80S.
LONG TERM...MONDAY NIGHT THROUGH FRIDAY
LINGER PCPN IS POSSIBLE IN EASTERN AND SOUTHEASTERN IL MONDAY
EVENING BUT DRY WEATHER IS EXPECTED AFTER THAT. ANOTHER HIGH PRSS
AREA BUILDS IN AFTER THIS ROUND OF PCPN DO DRY WEATHER IS EXPECTED
TUESDAY THROUGH WEDNESDAY NIGHT. REMAINDER OF THE WEEK SHOULD BE
DRY TOO...BUT BOTH ECMWF AND GFS ARE TRYING TO BRING MORE PCPN
INTO THE REGION FOR LAST PART OF THE WEEK. SOME UNCERTAINTY HERE
AS BOTH MODELS BUILD A RIDGE OVER THE REGION...THEY JUST DIFFER ON
HOW STEEP THE RIDGE WILL BE. THE ECMWF HAS A STEEPER RIDGE...WHICH WILL
PREVENT PCPN...WHILE THE GFS IS SOMEWHAT FLATTER...WHICH WOULD ALLOW
SOME PCPN TO MOVE INTO THE REGION. SO FOR NOW...WILL JUST HAVE
SILENT 20PCT IN THE WESTERN HALF FOR THUR THROUGH FRI.
TEMPS WILL BE AROUND NORMAL TO START THE WEEK BUT SHOULD WARM TO
THE MIDDLE 80S BY THE END OF THE WEEK. TEMPS COULD END UP BEING
WARMER...AS EVIDENCE OF 850 TEMPS OF AROUND 20C BEING FORECAST BY
THE MODELS.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1230 PM CDT SAT JUN 15 2013
.UPDATE...
ISSUED AT 632 AM CDT SAT JUN 15 2013
MCV IS QUITE NOTICEABLE ON RADAR AS THE DROP IN RETURNS PASSING
BETWEEN KDBQ/KMLI. THE NEWEST RAP TRENDS HAS THIS FEATURE EXITING
THE CWFA BY MID MORNING WHICH IS EXPECTED TO CORRESPOND WITH AN
END TO THE PRECIPITATION.
DRY CONDITIONS SHOULD THEN BE SEEN FROM LATE MORNING THROUGH EARLY
AFTERNOON DUE TO BUILDING HEIGHTS ALOFT. DIURNAL HEATING WILL
DESTABILIZE THE ATMOSPHERE DURING THE AFTERNOON AND LEFT OVER
BOUNDARIES FROM THE NOCTURNAL CONVECTION WILL PROVIDE THE FOCUS
FOR DIURNAL CONVECTION DURING THE AFTERNOON. TRENDS IN THE FCST
SOUNDINGS FROM THE RAP SUGGEST CONVECTIVE TEMPERATURES IN THE
UPPER 80S AND 90S AND A CAP IN PLACE. IF CORRECT...THEN CONVECTION
WOULD HAVE TO WAIT UNTIL EVENING WITH THE APPROACH OF THE NE/KS
SHORTWAVE AND THE NEWLY CREATED MCS.
PRELIMINARY DATA OFF THE 12Z SOUNDING SUGGESTS A CONVECTIVE
TEMPERATURE IN THE LOWER 80S. ASSUMING THIS NUMBER WILL INCREASE
SLIGHTLY DURING THE DAY...IT WOULD STILL BE IN THE GENERAL RANGE
OF PREDICTED AFTERNOON MAX TEMPERATURES. THUS CONVECTION MAY HOLD
OFF UNTIL LATE AFTERNOON BEFORE DEVELOPING. ..08..
UPDATE ISSUED AT 454 AM CDT SAT JUN 15 2013
A FAIRLY SUBSTANTIAL UPDATE TO THE FCST HAS BEEN DONE TO REFLECT
CURRENT TRENDS.
THE MCS OVER THE AREA IS RAPIDLY DECAYING AS IT MOVES AWAY FROM
THE BETTER SUPPORT AND MOISTURE.
MESOANALYSIS HAS A WAKE LOW NEARING KOTM WITH A MESOHIGH IN WEST
CENTRAL ILLINOIS JUST EAST OF THE MISSISSIPPI. OUTFLOW BOUNDARIES
ARE ACROSS CENTRAL ILLINOIS AND INTO CENTRAL MISSOURI.
WATER VAPOR SHOWS THE RESPECTABLE MCV AND ASSOCIATED SHORTWAVE
MOVED ROUGHLY OVER KDSM AND RAP TRENDS HAVE IT REACHING THE
MISSISSIPPI BY MID MORNING. THUS THE MCS WILL CONTINUE TO DECAY BUT
OVERALL LIFT FROM THE MCV WILL HELP GENERATE ISOLATED TO SCATTERED
CONVECTION FOR THE NEXT SEVERAL HOURS.
BUILDING HEIGHTS FROM MID MORNING THROUGH MID DAY SHOULD THEN
RESULT IN A LULL IN THE PRECIPITATION WITH MAINLY DRY CONDITIONS
EXPECTED.
THE NEXT ROUND OF ORGANIZED CONVECTION WILL DEVELOP WITH THE NEXT
SHORTWAVE THAT IS ENTERING THE WESTERN PARTS OF NE/KS. THIS
SHORTWAVE IS EXPECTED TO INITIATE CONVECTION FROM EASTERN NEBRASKA
INTO WESTERN IOWA FROM MID DAY TO EARLY AFTERNOON. AS THIS
CONVECTION ORGANIZES DURING THE AFTERNOON IT WILL EVOLVE INTO THE
NEXT MCS THAT WILL AFFECT THE AREA LATE THIS AFTERNOON AND
TONIGHT. ..08..
&&
.SYNOPSIS...
ISSUED AT 315 AM CDT SAT JUN 15 2013
06Z SFC ANALYSIS HAS A SYNOPTIC LOW IN NORTHEAST NEBRASKA WITH A
WARM FRONT RUNNING INTO MISSOURI AND A COLD FRONT INTO SOUTHWEST
NEBRASKA. MESO LOWS AND HIGHS WERE ACROSS IOWA AND NEBRASKA
ASSOCIATED WITH THUNDERSTORM COMPLEXES. DEW POINTS WERE MAINLY IN
THE 50S AND 60S ACROSS THE MIDWEST WITH A NARROW TONGUE OF 70 DEW
POINTS FROM THE SOUTHERN PLAINS INTO EASTERN KANSAS. SATELLITE/RADAR
TRENDS HAVE AN MCS ACROSS IOWA THAT IS SLOWLY DECAYING WITH TIME.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 315 AM CDT SAT JUN 15 2013
NOWCASTING TOOLS HAVE BEEN USED FOR THE IMMEDIATE WX. THESE INDICATE
THE MCS WILL CONTINUE TO DECAY THROUGH SUNRISE WITH DISSIPATION
OCCURRING DURING THE MORNING HOURS.
MCS AND LIFT TOOLS THEN SUGGEST A PERIOD OF DRY WX WITH CLEARING
SKIES FROM MID TO LATE MORNING THROUGH EARLY AFTERNOON. THE NEXT
SHORTWAVE SHOULD INITIATE CONVECTION BY MID DAY OR EARLY AFTERNOON
ACROSS WESTERN IOWA THAT WILL EVOLVE INTO ANOTHER MCS BY EVENING
ACROSS CENTRAL AND EASTERN IOWA. STRONG DIURNAL HEATING AHEAD OF
THIS NEW COMPLEX SHOULD RESULT IN ISOLATED TO SCATTERED STORMS OVER
THE CWFA FROM MID AFTERNOON INTO EARLY EVENING.
SEVERE STORMS MAY BE POSSIBLE THIS AFTERNOON AND EVENING. HOWEVER...
HOW THE CURRENT MCS DECAYS AND HOW MUCH HEATING OCCURS DURING THE
DAY WILL DICTATE THE OVERALL SEVERE THREAT. THE RAP MODEL IS
SUGGESTING POSSIBLY TWO DIFFERENT BOUNDARIES ACROSS THE CWFA DURING
THE AFTERNOON THAT WOULD PROVIDE A FOCUS FOR NEW CONVECTION. ONE
BOUNDARY...THE NORTHERN ONE...APPEARS TO BE LAKE INDUCED. THE
SOUTHERN BOUNDARY LOOKS TO BE THE OUTFLOW BOUNDARY FROM THE CURRENT
MCS MOVING BACK NORTH AS A WARM FRONT.
THUNDERSTORMS SHOULD BE SEEN DURING THE EVENING HOURS ACROSS THE
AREA AS THE NEXT MCS MOVES THROUGH THE AREA. CONVECTION SHOULD BE IN
A WANING/DISSIPATING STAGE AFTER MIDNIGHT AS THE NEXT FRONT/BOUNDARY
BEGINS MOVING INTO THE CWFA. ..08..
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 315 AM CDT SAT JUN 15 2013
NW FLOW ALOFT AND SURFACE HIGH PRESSURE TO PROVIDE A BREAK IN THE
ACTIVE WEATHER PATTERN FROM MONDAY NIGHT THROUGH WED...THEN RAIN AND
THUNDERSTORM CHANCES RESUME LATE IN THE WEEK.
BEFORE THIS...SUNDAY IS NOW LOOKING LIKE IT WILL BE DRY AS THE
AREA WILL BE UNDER SHORTWAVE SUBSIDENCE AND ALL MODELS HAVE THE MAIN
FRONT SUPPRESSED WELL TO THE SOUTH ACROSS NORTHERN MO INTO CENTRAL
IL AND HIGH PRESSURE BUILDING OVERHEAD. HAVE THUS LIMITED POPS TO
SLIGHT CHANCES ONLY ACROSS THE FAR SOUTH. UNDER MOSTLY SUNNY
SKIES...HIGHS SHOULD BE CLOSE TO GUIDANCE IN THE LOWER TO MID 80S.
SUNDAY NIGHT...WEAK ELEVATED THETAE ADVECTION MAY TRIGGER SHOWERS
AND THUNDERSTORMS AND HAVE LOW CHANCES OVER ESPECIALLY THE SOUTH AND
WEST. THESE CHANCES INCREASE MONDAY WITH LIFT ALONG AND AHEAD OF A
SHORTWAVE AND ASSOCIATED LATE DAY COLD FRONTAL PASSAGE. HIGHS SHOULD
AGAIN REACH INTO THE LOWER TO MID 80S.
SURFACE HIGH PRESSURE AND A CANADIAN AIRMASS WILL THEN DRY WEATHER
WITH LOW HUMIDITY AND SOMEWHAT BELOW NORMAL TEMPERATURES FOR TUE AND
WED. ONE CAVEAT WILL BE A SHORTWAVE PASSAGE ON TUESDAY. THE 00Z
ECMWF IS STRONGER WITH THIS FEATURE THAN OTHER MODELS AND HAS
PRECIPITATION BREAKING OUT DURING THE DAY. WILL KEEP A DRY FORECAST
FOR NOW AND WATCH TO SEE IF THIS IS A NEW TREND OR A LIMITED TO JUST
THIS RUN.
HIGH PRESSURE PUSHES EAST THU AND FRI WITH A MORE ACTIVE TRAIN OF
SHORTWAVES PUSHING THROUGH THE UPPER RIDGE THAT WILL BEGIN TO
ADVANCE INTO THE CENTRAL U.S. TO BRING BACK CHANCES FOR
THUNDERSTORMS. RISING HEIGHTS AND WARM ADVECTION SHOULD RETURN
TEMPERATURES TO LATE JUNE NORMALS WITH HIGHS IN THE 80S AND LOWS IN
THE 60S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1225 PM CDT SAT JUN 15 2013
GENERALLY VFR CONDITIONS TO DOMINATE TERMINALS EXCEPT IN STRONGEST
THUNDERSTORMS NEXT 12 HOURS AND RISK OF PATCHY FOG TOWARD SUNRISE.
WEAK UPPER LEVEL DISTURBANCES WILL PRODUCE AREAS OF THUNDERSTORMS
AND SHOWERS AT ALL TERMINALS THROUGH 16/09Z. SCT-BKN CLOUDS WITH
BASES AOA 4K AGL WILL BRIEFLY LOWER TO 2-3K AGL IN STRONGEST STORMS.
BRIEF HEAVY RAINS MAY ALSO LOWER VISIBILITIES TO 1-3 MILES.
CONVECTION SHOULD SLIDE EAST BEFORE DAYBREAK WITH PATCHY FOG
POSSIBLE WITH VISIBILITIES LOCALLY REDUCED TO 2-5 MILES. ANY FOG
TO BURN OFF BY 16/14Z WITH MOSTLY SUNNY SKIES ON SUNDAY.
NICHOLS
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...08
SYNOPSIS...08
SHORT TERM...08
LONG TERM...SHEETS
AVIATION...NICHOLS
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
647 AM CDT SAT JUN 15 2013
.UPDATE...
ISSUED AT 632 AM CDT SAT JUN 15 2013
MCV IS QUITE NOTICEABLE ON RADAR AS THE DROP IN RETURNS PASSING
BETWEEN KDBQ/KMLI. THE NEWEST RAP TRENDS HAS THIS FEATURE EXITING
THE CWFA BY MID MORNING WHICH IS EXPECTED TO CORRESPOND WITH AN
END TO THE PRECIPITATION.
DRY CONDITIONS SHOULD THEN BE SEEN FROM LATE MORNING THROUGH EARLY
AFTERNOON DUE TO BUILDING HEIGHTS ALOFT. DIURNAL HEATING WILL
DESTABILIZE THE ATMOSPHERE DURING THE AFTERNOON AND LEFT OVER
BOUNDARIES FROM THE NOCTURNAL CONVECTION WILL PROVIDE THE FOCUS
FOR DIURNAL CONVECTION DURING THE AFTERNOON. TRENDS IN THE FCST
SOUNDINGS FROM THE RAP SUGGEST CONVECTIVE TEMPERATURES IN THE
UPPER 80S AND 90S AND A CAP IN PLACE. IF CORRECT...THEN CONVECTION
WOULD HAVE TO WAIT UNTIL EVENING WITH THE APPROACH OF THE NE/KS
SHORTWAVE AND THE NEWLY CREATED MCS.
PRELIMINARY DATA OFF THE 12Z SOUNDING SUGGESTS A CONVECTIVE
TEMPERATURE IN THE LOWER 80S. ASSUMING THIS NUMBER WILL INCREASE
SLIGHTLY DURING THE DAY...IT WOULD STILL BE IN THE GENERAL RANGE
OF PREDICTED AFTERNOON MAX TEMPERATURES. THUS CONVECTION MAY HOLD
OFF UNTIL LATE AFTERNOON BEFORE DEVELOPING. ..08..
UPDATE ISSUED AT 454 AM CDT SAT JUN 15 2013
A FAIRLY SUBSTANTIAL UPDATE TO THE FCST HAS BEEN DONE TO REFLECT
CURRENT TRENDS.
THE MCS OVER THE AREA IS RAPIDLY DECAYING AS IT MOVES AWAY FROM
THE BETTER SUPPORT AND MOISTURE.
MESOANALYSIS HAS A WAKE LOW NEARING KOTM WITH A MESOHIGH IN WEST
CENTRAL ILLINOIS JUST EAST OF THE MISSISSIPPI. OUTFLOW BOUNDARIES
ARE ACROSS CENTRAL ILLINOIS AND INTO CENTRAL MISSOURI.
WATER VAPOR SHOWS THE RESPECTABLE MCV AND ASSOCIATED SHORTWAVE
MOVED ROUGHLY OVER KDSM AND RAP TRENDS HAVE IT REACHING THE
MISSISSIPPI BY MID MORNING. THUS THE MCS WILL CONTINUE TO DECAY BUT
OVERALL LIFT FROM THE MCV WILL HELP GENERATE ISOLATED TO SCATTERED
CONVECTION FOR THE NEXT SEVERAL HOURS.
BUILDING HEIGHTS FROM MID MORNING THROUGH MID DAY SHOULD THEN
RESULT IN A LULL IN THE PRECIPITATION WITH MAINLY DRY CONDITIONS
EXPECTED.
THE NEXT ROUND OF ORGANIZED CONVECTION WILL DEVELOP WITH THE NEXT
SHORTWAVE THAT IS ENTERING THE WESTERN PARTS OF NE/KS. THIS
SHORTWAVE IS EXPECTED TO INITIATE CONVECTION FROM EASTERN NEBRASKA
INTO WESTERN IOWA FROM MID DAY TO EARLY AFTERNOON. AS THIS
CONVECTION ORGANIZES DURING THE AFTERNOON IT WILL EVOLVE INTO THE
NEXT MCS THAT WILL AFFECT THE AREA LATE THIS AFTERNOON AND
TONIGHT. ..08..
&&
.SYNOPSIS...
ISSUED AT 315 AM CDT SAT JUN 15 2013
06Z SFC ANALYSIS HAS A SYNOPTIC LOW IN NORTHEAST NEBRASKA WITH A
WARM FRONT RUNNING INTO MISSOURI AND A COLD FRONT INTO SOUTHWEST
NEBRASKA. MESO LOWS AND HIGHS WERE ACROSS IOWA AND NEBRASKA
ASSOCIATED WITH THUNDERSTORM COMPLEXES. DEW POINTS WERE MAINLY IN
THE 50S AND 60S ACROSS THE MIDWEST WITH A NARROW TONGUE OF 70 DEW
POINTS FROM THE SOUTHERN PLAINS INTO EASTERN KANSAS. SATELLITE/RADAR
TRENDS HAVE AN MCS ACROSS IOWA THAT IS SLOWLY DECAYING WITH TIME.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 315 AM CDT SAT JUN 15 2013
NOWCASTING TOOLS HAVE BEEN USED FOR THE IMMEDIATE WX. THESE INDICATE
THE MCS WILL CONTINUE TO DECAY THROUGH SUNRISE WITH DISSIPATION
OCCURRING DURING THE MORNING HOURS.
MCS AND LIFT TOOLS THEN SUGGEST A PERIOD OF DRY WX WITH CLEARING
SKIES FROM MID TO LATE MORNING THROUGH EARLY AFTERNOON. THE NEXT
SHORTWAVE SHOULD INITIATE CONVECTION BY MID DAY OR EARLY AFTERNOON
ACROSS WESTERN IOWA THAT WILL EVOLVE INTO ANOTHER MCS BY EVENING
ACROSS CENTRAL AND EASTERN IOWA. STRONG DIURNAL HEATING AHEAD OF
THIS NEW COMPLEX SHOULD RESULT IN ISOLATED TO SCATTERED STORMS OVER
THE CWFA FROM MID AFTERNOON INTO EARLY EVENING.
SEVERE STORMS MAY BE POSSIBLE THIS AFTERNOON AND EVENING. HOWEVER...
HOW THE CURRENT MCS DECAYS AND HOW MUCH HEATING OCCURS DURING THE
DAY WILL DICTATE THE OVERALL SEVERE THREAT. THE RAP MODEL IS
SUGGESTING POSSIBLY TWO DIFFERENT BOUNDARIES ACROSS THE CWFA DURING
THE AFTERNOON THAT WOULD PROVIDE A FOCUS FOR NEW CONVECTION. ONE
BOUNDARY...THE NORTHERN ONE...APPEARS TO BE LAKE INDUCED. THE
SOUTHERN BOUNDARY LOOKS TO BE THE OUTFLOW BOUNDARY FROM THE CURRENT
MCS MOVING BACK NORTH AS A WARM FRONT.
THUNDERSTORMS SHOULD BE SEEN DURING THE EVENING HOURS ACROSS THE
AREA AS THE NEXT MCS MOVES THROUGH THE AREA. CONVECTION SHOULD BE IN
A WANING/DISSIPATING STAGE AFTER MIDNIGHT AS THE NEXT FRONT/BOUNDARY
BEGINS MOVING INTO THE CWFA. ..08..
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 315 AM CDT SAT JUN 15 2013
NW FLOW ALOFT AND SURFACE HIGH PRESSURE TO PROVIDE A BREAK IN THE
ACTIVE WEATHER PATTERN FROM MONDAY NIGHT THROUGH WED...THEN RAIN AND
THUNDERSTORM CHANCES RESUME LATE IN THE WEEK.
BEFORE THIS...SUNDAY IS NOW LOOKING LIKE IT WILL BE DRY AS THE
AREA WILL BE UNDER SHORTWAVE SUBSIDENCE AND ALL MODELS HAVE THE MAIN
FRONT SUPPRESSED WELL TO THE SOUTH ACROSS NORTHERN MO INTO CENTRAL
IL AND HIGH PRESSURE BUILDING OVERHEAD. HAVE THUS LIMITED POPS TO
SLIGHT CHANCES ONLY ACROSS THE FAR SOUTH. UNDER MOSTLY SUNNY
SKIES...HIGHS SHOULD BE CLOSE TO GUIDANCE IN THE LOWER TO MID 80S.
SUNDAY NIGHT...WEAK ELEVATED THETAE ADVECTION MAY TRIGGER SHOWERS
AND THUNDERSTORMS AND HAVE LOW CHANCES OVER ESPECIALLY THE SOUTH AND
WEST. THESE CHANCES INCREASE MONDAY WITH LIFT ALONG AND AHEAD OF A
SHORTWAVE AND ASSOCIATED LATE DAY COLD FRONTAL PASSAGE. HIGHS SHOULD
AGAIN REACH INTO THE LOWER TO MID 80S.
SURFACE HIGH PRESSURE AND A CANADIAN AIRMASS WILL THEN DRY WEATHER
WITH LOW HUMIDITY AND SOMEWHAT BELOW NORMAL TEMPERATURES FOR TUE AND
WED. ONE CAVEAT WILL BE A SHORTWAVE PASSAGE ON TUESDAY. THE 00Z
ECMWF IS STRONGER WITH THIS FEATURE THAN OTHER MODELS AND HAS
PRECIPITATION BREAKING OUT DURING THE DAY. WILL KEEP A DRY FORECAST
FOR NOW AND WATCH TO SEE IF THIS IS A NEW TREND OR A LIMITED TO JUST
THIS RUN.
HIGH PRESSURE PUSHES EAST THU AND FRI WITH A MORE ACTIVE TRAIN OF
SHORTWAVES PUSHING THROUGH THE UPPER RIDGE THAT WILL BEGIN TO
ADVANCE INTO THE CENTRAL U.S. TO BRING BACK CHANCES FOR
THUNDERSTORMS. RISING HEIGHTS AND WARM ADVECTION SHOULD RETURN
TEMPERATURES TO LATE JUNE NORMALS WITH HIGHS IN THE 80S AND LOWS IN
THE 60S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 632 AM CDT SAT JUN 15 2013
OVERNIGHT TSRA COMPLEX IS RAPIDLY DISSIPATING AND ALL CONVECTION
SHOULD BE GONE BY 15Z/15. OVERALL VFR CONDITIONS ARE EXPECTED
THROUGH 21Z/15 BUT A BRIEF PERIOD OF MVFR/IFR CONDITIONS MAY BE
REALIZED AT KMLI AND TO A LESSER EXTENT AT KDBQ AS THE CIRCULATION
FROM THE TSRA COMPLEX MOVES INTO ILLINOIS. AFT 21Z/15 THE 12Z TAFS
HAVE VFR CONDITIONS BUT TSRA THAT DVLP WILL HAVE THE POTENTIAL TO
CREATE MVFR/IFR CONDITIONS IF THEY AFFECT A TAF SITE. ANOTHER TSRA
COMPLEX WILL AFFECT EASTERN IOWA/NORTHERN ILLINOIS AFT 00Z/16
WHICH MAY RESULT IN MVFR CONDITIONS. ..08..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...08
SYNOPSIS...08
SHORT TERM...08
LONG TERM...SHEETS
AVIATION...08
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
507 AM CDT SAT JUN 15 2013
.UPDATE...
ISSUED AT 454 AM CDT SAT JUN 15 2013
A FAIRLY SUBSTANTIAL UPDATE TO THE FCST HAS BEEN DONE TO REFLECT
CURRENT TRENDS.
THE MCS OVER THE AREA IS RAPIDLY DECAYING AS IT MOVES AWAY FROM
THE BETTER SUPPORT AND MOISTURE.
MESOANALYSIS HAS A WAKE LOW NEARING KOTM WITH A MESOHIGH IN WEST
CENTRAL ILLINOIS JUST EAST OF THE MISSISSIPPI. OUTFLOW BOUNDARIES
ARE ACROSS CENTRAL ILLINOIS AND INTO CENTRAL MISSOURI.
WATER VAPOR SHOWS THE RESPECTABLE MCV AND ASSOCIATED SHORTWAVE
MOVED ROUGHLY OVER KDSM AND RAP TRENDS HAVE IT REACHING THE
MISSISSIPPI BY MID MORNING. THUS THE MCS WILL CONTINUE TO DECAY BUT
OVERALL LIFT FROM THE MCV WILL HELP GENERATE ISOLATED TO SCATTERED
CONVECTION FOR THE NEXT SEVERAL HOURS.
BUILDING HEIGHTS FROM MID MORNING THROUGH MID DAY SHOULD THEN
RESULT IN A LULL IN THE PRECIPITATION WITH MAINLY DRY CONDITIONS
EXPECTED.
THE NEXT ROUND OF ORGANIZED CONVECTION WILL DEVELOP WITH THE NEXT
SHORTWAVE THAT IS ENTERING THE WESTERN PARTS OF NE/KS. THIS
SHORTWAVE IS EXPECTED TO INITIATE CONVECTION FROM EASTERN NEBRASKA
INTO WESTERN IOWA FROM MID DAY TO EARLY AFTERNOON. AS THIS
CONVECTION ORGANIZES DURING THE AFTERNOON IT WILL EVOLVE INTO THE
NEXT MCS THAT WILL AFFECT THE AREA LATE THIS AFTERNOON AND
TONIGHT. ..08..
&&
.SYNOPSIS...
ISSUED AT 315 AM CDT SAT JUN 15 2013
06Z SFC ANALYSIS HAS A SYNOPTIC LOW IN NORTHEAST NEBRASKA WITH A
WARM FRONT RUNNING INTO MISSOURI AND A COLD FRONT INTO SOUTHWEST
NEBRASKA. MESO LOWS AND HIGHS WERE ACROSS IOWA AND NEBRASKA
ASSOCIATED WITH THUNDERSTORM COMPLEXES. DEW POINTS WERE MAINLY IN
THE 50S AND 60S ACROSS THE MIDWEST WITH A NARROW TONGUE OF 70 DEW
POINTS FROM THE SOUTHERN PLAINS INTO EASTERN KANSAS. SATELLITE/RADAR
TRENDS HAVE AN MCS ACROSS IOWA THAT IS SLOWLY DECAYING WITH TIME.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 315 AM CDT SAT JUN 15 2013
NOWCASTING TOOLS HAVE BEEN USED FOR THE IMMEDIATE WX. THESE INDICATE
THE MCS WILL CONTINUE TO DECAY THROUGH SUNRISE WITH DISSIPATION
OCCURRING DURING THE MORNING HOURS.
MCS AND LIFT TOOLS THEN SUGGEST A PERIOD OF DRY WX WITH CLEARING
SKIES FROM MID TO LATE MORNING THROUGH EARLY AFTERNOON. THE NEXT
SHORTWAVE SHOULD INITIATE CONVECTION BY MID DAY OR EARLY AFTERNOON
ACROSS WESTERN IOWA THAT WILL EVOLVE INTO ANOTHER MCS BY EVENING
ACROSS CENTRAL AND EASTERN IOWA. STRONG DIURNAL HEATING AHEAD OF
THIS NEW COMPLEX SHOULD RESULT IN ISOLATED TO SCATTERED STORMS OVER
THE CWFA FROM MID AFTERNOON INTO EARLY EVENING.
SEVERE STORMS MAY BE POSSIBLE THIS AFTERNOON AND EVENING. HOWEVER...
HOW THE CURRENT MCS DECAYS AND HOW MUCH HEATING OCCURS DURING THE
DAY WILL DICTATE THE OVERALL SEVERE THREAT. THE RAP MODEL IS
SUGGESTING POSSIBLY TWO DIFFERENT BOUNDARIES ACROSS THE CWFA DURING
THE AFTERNOON THAT WOULD PROVIDE A FOCUS FOR NEW CONVECTION. ONE
BOUNDARY...THE NORTHERN ONE...APPEARS TO BE LAKE INDUCED. THE
SOUTHERN BOUNDARY LOOKS TO BE THE OUTFLOW BOUNDARY FROM THE CURRENT
MCS MOVING BACK NORTH AS A WARM FRONT.
THUNDERSTORMS SHOULD BE SEEN DURING THE EVENING HOURS ACROSS THE
AREA AS THE NEXT MCS MOVES THROUGH THE AREA. CONVECTION SHOULD BE IN
A WANING/DISSIPATING STAGE AFTER MIDNIGHT AS THE NEXT FRONT/BOUNDARY
BEGINS MOVING INTO THE CWFA. ..08..
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 315 AM CDT SAT JUN 15 2013
NW FLOW ALOFT AND SURFACE HIGH PRESSURE TO PROVIDE A BREAK IN THE
ACTIVE WEATHER PATTERN FROM MONDAY NIGHT THROUGH WED...THEN RAIN AND
THUNDERSTORM CHANCES RESUME LATE IN THE WEEK.
BEFORE THIS...SUNDAY IS NOW LOOKING LIKE IT WILL BE DRY AS THE
AREA WILL BE UNDER SHORTWAVE SUBSIDENCE AND ALL MODELS HAVE THE MAIN
FRONT SUPPRESSED WELL TO THE SOUTH ACROSS NORTHERN MO INTO CENTRAL
IL AND HIGH PRESSURE BUILDING OVERHEAD. HAVE THUS LIMITED POPS TO
SLIGHT CHANCES ONLY ACROSS THE FAR SOUTH. UNDER MOSTLY SUNNY
SKIES...HIGHS SHOULD BE CLOSE TO GUIDANCE IN THE LOWER TO MID 80S.
SUNDAY NIGHT...WEAK ELEVATED THETAE ADVECTION MAY TRIGGER SHOWERS
AND THUNDERSTORMS AND HAVE LOW CHANCES OVER ESPECIALLY THE SOUTH AND
WEST. THESE CHANCES INCREASE MONDAY WITH LIFT ALONG AND AHEAD OF A
SHORTWAVE AND ASSOCIATED LATE DAY COLD FRONTAL PASSAGE. HIGHS SHOULD
AGAIN REACH INTO THE LOWER TO MID 80S.
SURFACE HIGH PRESSURE AND A CANADIAN AIRMASS WILL THEN DRY WEATHER
WITH LOW HUMIDITY AND SOMEWHAT BELOW NORMAL TEMPERATURES FOR TUE AND
WED. ONE CAVEAT WILL BE A SHORTWAVE PASSAGE ON TUESDAY. THE 00Z
ECMWF IS STRONGER WITH THIS FEATURE THAN OTHER MODELS AND HAS
PRECIPITATION BREAKING OUT DURING THE DAY. WILL KEEP A DRY FORECAST
FOR NOW AND WATCH TO SEE IF THIS IS A NEW TREND OR A LIMITED TO JUST
THIS RUN.
HIGH PRESSURE PUSHES EAST THU AND FRI WITH A MORE ACTIVE TRAIN OF
SHORTWAVES PUSHING THROUGH THE UPPER RIDGE THAT WILL BEGIN TO
ADVANCE INTO THE CENTRAL U.S. TO BRING BACK CHANCES FOR
THUNDERSTORMS. RISING HEIGHTS AND WARM ADVECTION SHOULD RETURN
TEMPERATURES TO LATE JUNE NORMALS WITH HIGHS IN THE 80S AND LOWS IN
THE 60S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1135 PM CDT FRI JUN 14 2013
TIMING OF PRECIPITATION THE MAIN CHALLENGE WITH 06Z TAFS. BOWING
LINE OF STORMS CURRENTLY OVER SOUTH CENTRAL INTO SOUTHWEST
IOWA WILL LIKELY INTERRUPT LOW LEVEL JET INTO EASTERN IOWA FOR AS
LONG AS THE LINE CONTINUES. FAIRLY LARGE STRATIFORM RAIN SHIELD
WITH EMBEDDED STORMS OVER CENTRAL INTO NORTHERN IOWA MOVING
EASTWARD WITH AN APPARENT CONVECTIVELY ENHANCED SHORTWAVE.
THUS... DESPITE INTERRUPT OF LOW LEVEL JET... SUFFICIENT FORCING
FROM AFOREMENTIONED WAVE SHOULD ALLOW FOR INCREASE IN RAIN WITH
SOME STORMS OVERNIGHT. IF SOUTHERN IOWA LINE WEAKENS ALLOWING
LOW LEVEL JET TO IMPINGE ON EASTERN IOWA THEN STRONG CONVERGENCE
AND MOISTURE TRANSPORT COULD LEAD TO INTENSIFICATION OF CONVECTION
OVER AREA LATER TONIGHT UNTIL MID MORNING SATURDAY...WITH LOCALLY
HEAVY RAINS. ANTICIPATE A BREAK OR RELATIVE LULL IN PRECIPITATION
BY MIDDAY WITH ADDITIONAL DEVELOPMENT BY MID AFTERNOON INTO SATURDAY
EVENING AHEAD OF NEXT DISTURBANCE. POTENTIAL EXISTS FOR SOME SEVERE
STORMS. UNCERTAINTY WITH COVERAGE AND LOCATION AND THUS VCTS MENTION
DURING THE AFTERNOON AND EVENING AT ALL SITES. OVERALL... EXPECT
MVFR TO POSSIBLY IFR CONDITIONS ESPECIALLY FOR VSBYS WITH ANY
STORMS OTHERWISE...VFR CONDITIONS TO PREVAIL. WINDS LIKELY TO
FAVOR SOUTHERLY THROUGH SATURDAY EXCEPT VARIABLE IN STORMS. COULD
SEE SOME GUSTS BY AFTERNOON. SATURDAY NIGHT WINDS SHOULD BECOME
LIGHT AND SHIFT TO WESTERLY.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...08
SYNOPSIS...08
SHORT TERM...08
LONG TERM...SHEETS
AVIATION...05
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
316 AM CDT SAT JUN 15 2013
.SYNOPSIS...
ISSUED AT 315 AM CDT SAT JUN 15 2013
06Z SFC ANALYSIS HAS A SYNOPTIC LOW IN NORTHEAST NEBRASKA WITH A
WARM FRONT RUNNING INTO MISSOURI AND A COLD FRONT INTO SOUTHWEST
NEBRASKA. MESO LOWS AND HIGHS WERE ACROSS IOWA AND NEBRASKA
ASSOCIATED WITH THUNDERSTORM COMPLEXES. DEW POINTS WERE MAINLY IN
THE 50S AND 60S ACROSS THE MIDWEST WITH A NARROW TONGUE OF 70 DEW
POINTS FROM THE SOUTHERN PLAINS INTO EASTERN KANSAS. SATELLITE/RADAR
TRENDS HAVE AN MCS ACROSS IOWA THAT IS SLOWLY DECAYING WITH TIME.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 315 AM CDT SAT JUN 15 2013
NOWCASTING TOOLS HAVE BEEN USED FOR THE IMMEDIATE WX. THESE INDICATE
THE MCS WILL CONTINUE TO DECAY THROUGH SUNRISE WITH DISSIPATION
OCCURRING DURING THE MORNING HOURS.
MCS AND LIFT TOOLS THEN SUGGEST A PERIOD OF DRY WX WITH CLEARING
SKIES FROM MID TO LATE MORNING THROUGH EARLY AFTERNOON. THE NEXT
SHORTWAVE SHOULD INITIATE CONVECTION BY MID DAY OR EARLY AFTERNOON
ACROSS WESTERN IOWA THAT WILL EVOLVE INTO ANOTHER MCS BY EVENING
ACROSS CENTRAL AND EASTERN IOWA. STRONG DIURNAL HEATING AHEAD OF
THIS NEW COMPLEX SHOULD RESULT IN ISOLATED TO SCATTERED STORMS OVER
THE CWFA FROM MID AFTERNOON INTO EARLY EVENING.
SEVERE STORMS MAY BE POSSIBLE THIS AFTERNOON AND EVENING. HOWEVER...
HOW THE CURRENT MCS DECAYS AND HOW MUCH HEATING OCCURS DURING THE
DAY WILL DICTATE THE OVERALL SEVERE THREAT. THE RAP MODEL IS
SUGGESTING POSSIBLY TWO DIFFERENT BOUNDARIES ACROSS THE CWFA DURING
THE AFTERNOON THAT WOULD PROVIDE A FOCUS FOR NEW CONVECTION. ONE
BOUNDARY...THE NORTHERN ONE...APPEARS TO BE LAKE INDUCED. THE
SOUTHERN BOUNDARY LOOKS TO BE THE OUTFLOW BOUNDARY FROM THE CURRENT
MCS MOVING BACK NORTH AS A WARM FRONT.
THUNDERSTORMS SHOULD BE SEEN DURING THE EVENING HOURS ACROSS THE
AREA AS THE NEXT MCS MOVES THROUGH THE AREA. CONVECTION SHOULD BE IN
A WANING/DISSIPATING STAGE AFTER MIDNIGHT AS THE NEXT FRONT/BOUNDARY
BEGINS MOVING INTO THE CWFA. ..08..
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 315 AM CDT SAT JUN 15 2013
NW FLOW ALOFT AND SURFACE HIGH PRESSURE TO PROVIDE A BREAK IN THE
ACTIVE WEATHER PATTERN FROM MONDAY NIGHT THROUGH WED...THEN RAIN AND
THUNDERSTORM CHANCES RESUME LATE IN THE WEEK.
BEFORE THIS...SUNDAY IS NOW LOOKING LIKE IT WILL BE DRY AS THE
AREA WILL BE UNDER SHORTWAVE SUBSIDENCE AND ALL MODELS HAVE THE MAIN
FRONT SUPPRESSED WELL TO THE SOUTH ACROSS NORTHERN MO INTO CENTRAL
IL AND HIGH PRESSURE BUILDING OVERHEAD. HAVE THUS LIMITED POPS TO
SLIGHT CHANCES ONLY ACROSS THE FAR SOUTH. UNDER MOSTLY SUNNY
SKIES...HIGHS SHOULD BE CLOSE TO GUIDANCE IN THE LOWER TO MID 80S.
SUNDAY NIGHT...WEAK ELEVATED THETAE ADVECTION MAY TRIGGER SHOWERS
AND THUNDERSTORMS AND HAVE LOW CHANCES OVER ESPECIALLY THE SOUTH AND
WEST. THESE CHANCES INCREASE MONDAY WITH LIFT ALONG AND AHEAD OF A
SHORTWAVE AND ASSOCIATED LATE DAY COLD FRONTAL PASSAGE. HIGHS SHOULD
AGAIN REACH INTO THE LOWER TO MID 80S.
SURFACE HIGH PRESSURE AND A CANADIAN AIRMASS WILL THEN DRY WEATHER
WITH LOW HUMIDITY AND SOMEWHAT BELOW NORMAL TEMPERATURES FOR TUE AND
WED. ONE CAVEAT WILL BE A SHORTWAVE PASSAGE ON TUESDAY. THE 00Z
ECMWF IS STRONGER WITH THIS FEATURE THAN OTHER MODELS AND HAS
PRECIPITATION BREAKING OUT DURING THE DAY. WILL KEEP A DRY FORECAST
FOR NOW AND WATCH TO SEE IF THIS IS A NEW TREND OR A LIMITED TO JUST
THIS RUN.
HIGH PRESSURE PUSHES EAST THU AND FRI WITH A MORE ACTIVE TRAIN OF
SHORTWAVES PUSHING THROUGH THE UPPER RIDGE THAT WILL BEGIN TO
ADVANCE INTO THE CENTRAL U.S. TO BRING BACK CHANCES FOR
THUNDERSTORMS. RISING HEIGHTS AND WARM ADVECTION SHOULD RETURN
TEMPERATURES TO LATE JUNE NORMALS WITH HIGHS IN THE 80S AND LOWS IN
THE 60S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1135 PM CDT FRI JUN 14 2013
TIMING OF PRECIPITATION THE MAIN CHALLENGE WITH 06Z TAFS. BOWING
LINE OF STORMS CURRENTLY OVER SOUTH CENTRAL INTO SOUTHWEST
IOWA WILL LIKELY INTERRUPT LOW LEVEL JET INTO EASTERN IOWA FOR AS
LONG AS THE LINE CONTINUES. FAIRLY LARGE STRATIFORM RAIN SHIELD
WITH EMBEDDED STORMS OVER CENTRAL INTO NORTHERN IOWA MOVING
EASTWARD WITH AN APPARENT CONVECTIVELY ENHANCED SHORTWAVE.
THUS... DESPITE INTERRUPT OF LOW LEVEL JET... SUFFICIENT FORCING
FROM AFOREMENTIONED WAVE SHOULD ALLOW FOR INCREASE IN RAIN WITH
SOME STORMS OVERNIGHT. IF SOUTHERN IOWA LINE WEAKENS ALLOWING
LOW LEVEL JET TO IMPINGE ON EASTERN IOWA THEN STRONG CONVERGENCE
AND MOISTURE TRANSPORT COULD LEAD TO INTENSIFICATION OF CONVECTION
OVER AREA LATER TONIGHT UNTIL MID MORNING SATURDAY...WITH LOCALLY
HEAVY RAINS. ANTICIPATE A BREAK OR RELATIVE LULL IN PRECIPITATION
BY MIDDAY WITH ADDITIONAL DEVELOPMENT BY MID AFTERNOON INTO SATURDAY
EVENING AHEAD OF NEXT DISTURBANCE. POTENTIAL EXISTS FOR SOME SEVERE
STORMS. UNCERTAINTY WITH COVERAGE AND LOCATION AND THUS VCTS MENTION
DURING THE AFTERNOON AND EVENING AT ALL SITES. OVERALL... EXPECT
MVFR TO POSSIBLY IFR CONDITIONS ESPECIALLY FOR VSBYS WITH ANY
STORMS OTHERWISE...VFR CONDITIONS TO PREVAIL. WINDS LIKELY TO
FAVOR SOUTHERLY THROUGH SATURDAY EXCEPT VARIABLE IN STORMS. COULD
SEE SOME GUSTS BY AFTERNOON. SATURDAY NIGHT WINDS SHOULD BECOME
LIGHT AND SHIFT TO WESTERLY.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...08
SHORT TERM...08
LONG TERM...SHEETS
AVIATION...05
AREA FORECAST DISCUSSION
NWS WICHITA KS
718 PM CDT SUN JUN 16 2013
.UPDATE...
ISSUED AT 718 PM CDT SUN JUN 16 2013
SVR TSRA THAT WERE PROLIFIC GOLFBALL-SIZED HAIL PRODUCERS OVER COWLEY
COUNTY HAVE DISSIPATED BUT HAVE ALSO UNLEASHED A W-NW MOVG OUTFLOW
BOUNDARY ACROSS SUMNER & HARPER COUNTIES & TOWARD KICT. A CELLS HAVE
DEVELOPED E OF THE OUTFLOW. ISOLD CELLS HAVE ALSO DEVELOPED OVER THE
SE CORNER OF KS AS WELL AS OVER EC KS. MID-LVL FLOW IS VERY WEAK & AS
SUCH FAVORS A RATHER CHAOTIC CONVECTIVE "PATTERN" FOR THE REST OF THE
EVENING. HAVE TEMPORARILY ASSIGNED 40-50% TSRA TO EXTREME SC-SE KS
WITH SHARP POP-GRADIENT N TOWARD KS TURNPIKE TIL 10 PM. HAVE ALSO
ADJUSTED TSRA PROBABILITIES FOR LATER THIS EVENING TO REFLECT ONSET OF
MCS THAT`LL SURGE SE TOWARD...THEN ACROSS...PRIMARILY SC KS. POP GAME
PLAN FROM MID-NGT TO 7 AM APPEARS ON TARGET. MADE MINOR ADJUSTMENTS TO
SKY GRIDS FOR EARLY THIS EVENING.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 311 PM CDT SUN JUN 16 2013
A RATHER COMPLICATED SCENARIO IS UNDERWAY ACROSS THE CENTRAL PLAINS
THIS AFTERNOON. AN OUTFLOW BOUNDARY WAS LOCATED ACROSS CENTRAL
KANSAS FROM NEAR KHUT EXTENDING NORTH AND WEST TOWARD NORTON KANSAS
AT 2 PM CDT. CU HAS DEVELOPED ON THE COOL SIDE OF THIS OUTFLOW
BOUNDARY WHILE THE OPERATIONAL ECM RAP SHOWS MINIMAL CINH WITHIN AN
AXIS OF 2000-2500 J/KG. THIS BOUNDARY MAY BECOME A FOCUS FOR DEEP
MOIST CONVECTION BY LATE AFTERNOON. ANOTHER DIFFUSE OUTFLOW BOUNDARY
WAS SITUATED NEAR THE OKLAHOMA STATE LINE WHERE WIDELY SCATTERED
SHOWERS AND THUNDERSTORMS WILL REMAIN POSSIBLE ESPECIALLY SOUTH OF
THE STATE LINE. FURTHER NORTH AND WEST ANOTHER OUTFLOW BOUNDARY WAS
SURGING SOUTH ACROSS WESTERN NEBRASKA WHILE HIGH-BASED THUNDERSTORMS
WERE DEVELOPING ACROSS THE FRONT RANGE DOWNSTREAM OF A PV ANOMALY
TRANSLATING EASTWARD ACROSS THE CENTRAL ROCKIES. THE LATEST 12Z
SUITE OF MODEL DATA HAS SHIFTED THE QPF AXIS A BIT FURTHER WEST
TONIGHT...HOWEVER THIS AREA REMAINS OVERTURNED FROM DEEP MOIST CONVECTION
LAST NIGHT/EARLY TODAY. ANY ACTIVITY DEVELOPING ALONG THE OUTFLOW
BOUNDARY ACROSS CENTRAL KANSAS WOULD BE STEERED TOWARD SOUTH CENTRAL
KANSAS THIS EVENING WHILE ANOTHER LINE OF SHOWERS AND THUNDERSTORMS
MAY PROPAGATE SOUTHEASTWARD OFF THE HIGH PLAINS OF WESTERN KANSAS
LATE TONIGHT WHILE MERGING WITH THE ACTIVITY DRIFTING SOUTH OUT OF
NEBRASKA. WILL MAINTAIN HIGH POPS ACROSS MUCH OF CENTRAL/SOUTH
CENTRAL KANSAS TONIGHT WHILE THE THREAT FOR FLOODING OVER SOUTHEAST
KANSAS APPEARS TO HAVE DIMINISHED SLIGHTLY...HOWEVER NO PLANS TO
REMOVE THE FLOOD WATCH AT THIS TIME GIVEN RAINFALL AMOUNTS BETWEEN
2-3 INCHES A FEW LOCATIONS.
MAINTAINED POPS ACROSS MAINLY SOUTHEAST KANSAS THROUGH EARLY
AFTERNOON ON MONDAY WITH SOME TIMING DIFFERENCES...HOWEVER BY LATE
AFTERNOON TEMPERATURES ARE EXPECTED RECOVER INTO THE LOW TO MID 80S
WITHIN A STABLE AIRMASS BEHIND THE DEPARTING MCS. THERE IS SOME
CONCERN FOR CONTINUED OVERNIGHT CONVECTION MOVING EASTWARD OFF THE
HIGH PLAINS MONDAY NIGHT AND AGAIN ON TUESDAY NIGHT ACROSS MAINLY
CENTRAL KANSAS. HOWEVER BETTER CHANCES FOR DEEP MOIST CONVECTION MAY
ARRIVE TOWARD THE MIDDLE OF THE WEEK AS A MORE ROBUST SHORTWAVE
TROUGH MOVES OVER THE CENTRAL AND NORTHERN PLAINS. SEASONABLE
TEMPERATURES ARE EXPECTED THROUGH THE PERIOD WITH HIGHS IN THE 80S
AND LOW IN THE 60S. -MCGUIRE
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 311 PM CDT SUN JUN 16 2013
LINGERING SHOWERS AND THUNDERSTORMS ARE POSSIBLE FOR THE EASTERN
THIRD OF KANSAS ON THURSDAY AS A SHORTWAVE EXITS THE AREA. A RIDGE
OVER THE CENTRAL U.S. WILL STAY PLANTED FOR MOST OF THIS TIME FRAME
WITHOUT A BREAKDOWN IN THE FLOW PATTERN UNTIL LATE IN THE WEEKEND
WHEN A TROUGH MOVES OVER THE NORTHERN U.S. THERE IS MODEL
DISAGREEMENT IN THE LOCATION AND TIMING OF A WAVE AHEAD OF THE MAIN
TROUGH. THUS ANY IMPACT TO THE AREA COULD ONLY BE CONSIDERED
PRELIMINARY AT THIS TIME. THE RIDGE IN PLACE WILL HELP SET THE STAGE
FOR TEMPERATURES CLIMBING ABOVE 90 ONCE MORE. -JUANITA
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 718 PM CDT SUN JUN 16 2013
NO DOUBT (+)TSRA TO POSE GREATEST THREAT FOR THE 17/00Z TAF EDITION.
WITH THE NOW DISSIPATED SVR TSRA OVER COWLEY COUNTY HAVING UNLEASHED
A W-NW MOVG OUTFLOW BOUNDARY...PIN-POINTING WHERE TSRA WILL FIRE OVER
THE NEXT 3 HOURS IS A PROBLEM AS AIRMASS HAS NO DOUBT BEEN MODIFIED.
HAVE ASSIGNED "VCTS" TO MOST TERMINALS FOR THIS EVENING & UPDATE AS
CONVECTIVE PICTURE COMES INTO BETTER FOCUS. CONFIDENCE INCREASES LATER
TONIGHT AS AN MCD IS STILL EXPECTED TO SURGE SE FROM W & NW KS ACROSS
CNTRL & ESPECIALLY SC KS. DAMAGING WINDS REMAIN THE GREATEST THREAT &
WILL NO DOUBT REQUIRE UPDATES WHEN THIS FACET OF FCST LIKEWISE COMES
INTO BETTER FOCUS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 67 85 64 84 / 80 60 10 10
HUTCHINSON 67 85 63 84 / 80 50 10 10
NEWTON 67 84 63 83 / 70 50 10 10
ELDORADO 67 84 63 83 / 70 50 10 10
WINFIELD-KWLD 68 85 65 84 / 80 60 10 10
RUSSELL 65 85 61 84 / 60 20 20 10
GREAT BEND 65 86 62 84 / 70 20 20 10
SALINA 66 85 62 84 / 60 20 10 10
MCPHERSON 66 85 62 83 / 80 40 10 10
COFFEYVILLE 68 83 65 85 / 70 70 10 10
CHANUTE 68 84 63 84 / 60 70 0 0
IOLA 68 83 62 83 / 60 60 0 0
PARSONS-KPPF 68 83 64 84 / 70 70 10 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH THROUGH MONDAY AFTERNOON FOR KSZ071-072-094>096-
098>100.
&&
$$
ES
AREA FORECAST DISCUSSION
NWS TOPEKA KS
618 PM CDT SUN JUN 16 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 326 PM CDT SUN JUN 16 2013
TRICKY FORECAST FOR THE FIRST 12-24 HOURS WITH MANY FACTORS IN PLAY
FOR CONVECTION POTENTIAL...AND DIFFERENCES IN GUIDANCE AS TO
HOW/WHERE/WHEN STORMS EVOLVE. CURRENTLY VERY LITTLE CIN OVER THE
FORECAST AREA WITH AN AREA OF GENERALLY 1500-2000J/KG CAPE BISECTING
THE FA FROM NW TO SE. BULK SHEAR HOWEVER IS QUITE LOW...LESS THAN
10KTS WITHIN THE FIRST 15KFT PER NAM SOUNDINGS. PER CU FIELD ON
VISIBLE AND WINDS IN OBS WOULD APPEAR THAT BOUNDARY HAS MADE IT
SOUTH OF EMPORIA...WITH SOME WEAK WIND CONVERGENCE JUST SOUTH. NOT
CONFIDENT OF DEVELOPMENT ON THIS BOUNDARY BUT WILL LEAVE A SLIGHT
CHANCE SOUTH AND WEST TO ACCOUNT FOR PROBABILITY.
STARTING TO SEE CONVECTION DEVELOP IN SW NEBRASKA AS WELL AS FAR SW
SOUTH DAKOTA AT THIS HOUR. MOISTURE AXIS AND CORFIDI VECTORS
INDICATE THESE STORMS WOULD MOVE TO THE EAST TO SOUTHEAST WITH
TIME...BECOMING A CLUSTER AND MOVING ACROSS WESTERN AND PORTIONS OF
CENTRAL KANSAS. HOW FAR EASTWARD THEY CAN DEVELOP IS IN
QUESTION...WITH THE NAM/GFS/EC TAKING THE BRUNT OF THE QPF MAINLY
WEST OF OUR FORECAST AREA. LAST FEW RUNS OF THE HRRR BRING A SQUALL
LINE ACROSS MUCH OF THE FORECAST AREA GENERALLY 9PM TO AFTER
MIDNIGHT. THINK THE EARLIER SCENARIO IS MORE LIKELY AND WILL TAKE
MOST OF THE LLJ ENERGY INTO THE WESTERNMOST STORM COMPLEX...THINKING
WON`T BE ABLE TO DEVELOP A LINE OF STORMS FURTHER EAST BACK TOWARD
THE COOLER AIR. ONCE AGAIN WILL GO WITH CHANCE POPS TO THE WEST AND
DECREASE CHANCES EAST...BUT NOT WILLING TO TAKE POPS OUT FAR EAST
JUST YET GIVEN MODEL DIFFERENCES. ENOUGH INSTABILITY WITH A LINE OF
STORMS TO MAKE WIND AND HEAVY RAIN A CONCERN...BUT SHEAR PROFILES
NOT AS FAVORABLE FOR LOW LEVEL ROTATION. STORMS MOVE EASTWARD
QUICKLY AND HAVE A DRY FORECAST ALL AREAS BY AFTERNOON. HAVE LOWS IN
THE 60S TONIGHT WITH HIGHS IN THE 80S ON MONDAY...COOLER SE WHERE
CLOUDS AND RAIN MAY LINGER A FEW HOURS INTO THE MORNING MONDAY. 67
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 326 PM CDT SUN JUN 16 2013
MID RANGE AND EXTENDED FORECAST (TUESDAY THROUGH SUNDAY)...
EXPECT LARGE SCALE RIDGING TO TAKE PLACE IN THE MID RANGE TO
EXTENDED PERIOD OF THE FORECAST...WHICH WILL LIKELY SPELL A
CONSISTENT PERIOD OF ABOVE NORMAL TEMPERATURES THROUGH THE END OF
THE WORK WEEK AND THROUGH NEXT THE WEEKEND. HIGHS WILL LIKELY
REACH THE MID TO UPPER 90S...HOWEVER AS THAT TIME PERIOD
APPROACHES AND MODELS CONTINUE CONSISTENCY IN BRINGING IN THE MID
LEVEL RIDGE PERHAPS WE COULD SEE TEMPERATURES LATE IN THE WEEK AND
THIS WEEKEND REACH THE TRIPLE DIGIT MARK...ESPECIALLY IN THE
WESTERN ZONES WHERE MOISTURE COULD BE A LITTLE HARDER TO COME BY.
PRECIP CHANCES THROUGH THE EXTENDED WILL BE TOUGH TO NAIL
DOWN...AS THERE ARE NO REAL STRONG MID LEVEL SIGNALS TO REALLY
TRACK FOR PRECIP. THE BEST CHANCE FOR PRECIP DOES LOOK LIKE IT
WILL TAKE PLACE IN THE MID TO LATE PART OF THE WEEK AS MODELS HINT
AT SOME STRONG CONVECTION TAKING PLACE OFF THE HIGH PLAINS...AND
DRAGGING THE CONVECTION EASTWARD THROUGH THE CENTRAL PLAINS. THE
POSITION OF THE MID LEVEL TROUGH AND THE SUBSEQUENT STEERING FLOW
WILL LIKELY DETERMINE THE EXACT TRACK OF THE PRECIP. SHOULD THE
RIDGE BECOME LESS AMPLIFIED THE W-SW STEERING FLOW MAY END UP OVER
THE FORECAST AREA...HOWEVER SHOULD THE RIDGE BE A LITTLE STRONGER
THAN ANTICIPATED IT WOULD SHUNT THE CONVECTION NORTH. EITHER
WAY...WILL MAINTAIN CHANCE POPS FOR THE WED NIGHT THROUGH FRIDAY
TIME FRAME FOR THESE SHOWERS. OTHERWISE...THE MAINLY DRY AND WARM
FORECAST DESCRIBED ABOVE WILL BE EXPECTED THROUGH THE EXTENDED.
JL
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 617 PM CDT SUN JUN 16 2013
FOR THE 00Z TAFS...THE AREA OF SHOWERS AND THUNDERSTORMS OVER
NEBRASKA AND NORTHWEST KANSAS WILL CONTINUE TO TRACK SOUTHEAST
TOWARD CENTRAL AND EASTERN KANSAS THROUGH THE EVENING AND OVERNIGHT
HOURS. THERE IS STILL SOME UNCERTAINTY REGARDING HOW WELL THESE
THUNDERSTORMS WILL HOLD TOGETHER AS THEY APPROACH THE AREA...AS WELL
AS THE TIMING OF ANY THUNDERSTORMS INTO THE TAF SITES SO HAVE KEPT
THE MENTION OF VCTS FOR OVERNIGHT TONIGHT AND WILL CONTINUE TO
MONITOR RADAR TRENDS. DRY CONDITIONS ARE EXPECTED FOR MUCH OF MONDAY
WITH LIGHT EASTERLY WINDS PREVAILING THROUGH THE DAY.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...67
LONG TERM...LEIGHTON
AVIATION...HENNECKE
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
337 PM CDT SAT JUN 15 2013
...UPDATED FOR LONG TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 202 PM CDT SAT JUN 15 2013
THE 12Z UPPER AIR ANALYSIS SHOWED BROAD RIDGING CONTINUING OVER THE
LOWER 48 STATES. NUMEROUS WEAK SHORTWAVE TROUGHS WERE EMBEDDED IN
THE FLOW OVER THE RIDGE. A STRONGER WAVE EXTENDED FROM OVER
WESTERN KANSAS INTO THE BIG BEND AREA OF SOUTHWEST TEXAS. THIS
WAVE HAD BROUGHT SOME EARLY MORNING SHOWERS AND THUNDERSTORMS TO
WESTERN KANSAS WHICH HAVE SINCE MOVED INTO CENTRAL AND EASTERN
KANSAS BY EARLY AFTERNOON. BEHIND THIS WAVE...SUBSIDENCE WAS
SPREADING ACROSS WESTERN KANSAS AS EVIDENT IN THE WATER VAPOR IMAGERY.
TO THE WEST OF THIS...A WEAK DISTURBANCE WAS MOVING EAST THROUGH
THE CENTRAL ROCKIES. A WEAK FRONTAL BOUNDARY EXTENDED FROM EASTERN
NEBRASKA ACROSS NORTHWEST KANSAS INTO EAST CENTRAL COLORADO. LOW
LEVEL MOISTURE CONTINUES TO STREAM NORTH TOWARD THE CENTRAL PLAINS AS
DEWPOINTS IN THE LOW TO MID 60S ADVECT INTO WESTERN AND CENTRAL KANSAS.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 202 PM CDT SAT JUN 15 2013
IT APPEARS THAT PORTIONS OF WESTERN AND CENTRAL KANSAS COULD HAVE
A DECENT SHOT AT RECEIVING RAIN LATE THIS AFTERNOON INTO
TONIGHT. THE NAM AND GFS MODELS SHOW A TREND OF THUNDERSTORMS
DEVELOPING OVER EASTERN COLORADO AND MOVING INTO WESTERN KANSAS
DURING THE EVENING HOURS. THE HRRR HAS BEEN SHOWING THIS TREND AS
WELL. THE LATEST RUNS OF THAT MODEL ARE SHOWING WIDELY SCATTERED
THUNDERSTORMS DEVELOPING OVER WEST CENTRAL KANSAS LATE THIS
AFTERNOON AND MOVING INTO CENTRAL KANSAS WITH ANOTHER ROUND OF
THUNDERSTORMS THAT DEVELOP OVER EASTERN COLORADO THEN MOVING
ACROSS NORTHWEST AND WEST CENTRAL KANSAS LATER THIS EVENING. THINK
THAT THE TWO AREAS OF STORMS DEPICTED BY THE HRRR MAY BE CORRECT
GIVEN THE LOCATION OF THE FRONTAL BOUNDARY AND INCREASING
INSTABILITY. THE SUBSIDENCE CURRENTLY OVER THE REGION MAY QUASH
ANY LATE AFTERNOON CONVECTION BUT MODEL SOUNDINGS SHOW THE AREA
BECOMING UNCAPPED BY 00Z SO CAN`T TOTALLY RULE OUT A STORM OR TWO.
LATER TONIGHT AM EXPECTING THUNDERSTORMS TO MOVE OUT INTO WEST
CENTRAL AND PARTS OF SOUTHWEST KANSAS. HAVE INCREASED
PRECIPITATION CHANCES TO 50-55 PERCENT ESPECIALLY IN THE AREA
NORTH OF A LINE FROM SYRACUSE THROUGH MONTEZUMA, DODGE CITY AND
LARNED BASED OFF OF TRENDS IN THE HRRR. THE MODELS HINT AT A LOW
LEVEL JET DEVELOPING TONIGHT WHICH COULD HELP SUSTAIN THINGS INTO
THE LATE NIGHT HOURS BUT THINK WE WILL SEE A DECREASING TREND
AFTER 06Z.
SUNDAY SHOULD STAR OUT PARTLY TO MOSTLY SUNNY. ANOTHER WEAK
SHORTWAVE IS PROGGED TO MOVE OUT OF THE ROCKIES DURING THE LATE
AFTERNOON HOURS. HARD TO TELL WHERE EXACTLY THUNDERSTORMS WILL
INITIATE GIVEN THE UNCERTAINTY OF THE FRONTAL POSITION AND THE
POTENTIAL FOR ANY LEFTOVER OUTFLOW BOUNDARIES. WILL CONTINUE THE
PREVIOUS FORECAST TREND OF INCREASING POPS INTO THE CHANCE
CATEGORY BY LATE AFTERNOON. HIGH TEMPERATURES ON SUNDAY MAY ALSO
BE A LITTLE PROBLEMATIC DEPENDING ON HOW MUCH AND WHERE RAINFALL
OCCURS TONIGHT. WILL KEEP HIGHS IN THE UPPER 80S TO NEAR 90 IN
MOST AREAS WITH SOME LOW 90S OUT ALONG THE COLORADO BORDER.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 333 PM CDT SAT JUN 15 2013
FOR THE LATE SUNDAY THROUGH EARLY WEDNESDAY PERIOD, A FLAT UPPER
LEVEL RIDGE WILL BE SITUATED OVER THE SOUTHERN AND CENTRAL ROCKIES, WITH
WEST-NORTHWESTERLY CROSS-MOUNTAIN, MID LEVEL, FLOW ACROSS THE HIGH
PLAINS. THIS PATTERN WILL LEAD TO WEAK MID LEVEL CAPPING AND SURFACE
LEE TROUGHING, ALONG WITH LOW LEVEL MOISTURE RETURN ON THE HIGH
PLAINS. IN ADDITION, THE SOUTHERN BRANCH OF THE WESTERLIES AT MID
AND HIGH LEVELS WILL BE SITUATED FROM THE SOUTHWESTERN UNITED
STATES ACROSS THE CENTRAL PLAINS. ALL THESE FACTORS ARE FAVORABLE
FOR NOCTURNAL STORM CLUSTERS TO DEVELOP THIS TIME OF YEAR ON THE FRONT
RANGE AND HIGH PLAINS EVERY EVENING AND NIGHTTIME. THEREFORE,
CHANCES OF THUNDERSTORMS WITH BENEFICIAL RAINS LOOK HIGH. BUT THE
EXACT PLACEMENT OF THE RAIN AREAS IS NOT KNOWN WITH HIGH
CONFIDENCE. LOTS OF COOL OUTFLOW FROM THE THUNDERSTORM CLUSTERS
WILL LEAD TO COOLER HIGH TEMPERATURES EACH DAY THROUGH TUESDAY.
THE BEST CHANCES FOR RAIN APPEAR TO BE SUNDAY AND MONDAY NIGHTS AS
MUCH MORE STABLE AIR COULD BE IN PLACE BY TUESDAY.
FOR THE WEDNESDAY TO FRIDAY PERIOD, UPPER LEVEL RIDGING IS EXPECTED
TO REDEVELOP ACROSS EASTERN KANSAS, MISSOURI AND OKLAHOMA, WITH
UPPER LEVEL TROUGHING OVER THE NORTHERN ROCKIES. THIS WILL LEAD TO
MUCH DRIER WEATHER AND WARMER TEMPERATURES, WITH HIGHS APPROACHING
100F BY FRIDAY AND SATURDAY. ISOLATED THUNDERSTORMS CANNOT BE RULED
OUT EACH AFTERNOON AND EVENING ALONG THE SOUTHERN EDGE OF THE WESTERLIES
NEAR THE LEE TROUGH IN WESTERN KANSAS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1250 PM CDT SAT JUN 15 2013
VFR CONDITIONS WILL PREVAIL ACROSS SOUTHWEST AND CENTRAL KANSAS
THROUGH THE FIRST PART OF THIS TAF PERIOD. WIDELY SCATTERED
THUNDERSTORMS ARE EXPECTED TO DEVELOP ACROSS WESTERN KANSAS ALONG
A WEAK FRONTAL BOUNDARY AND SHOULD MOVE THROUGH WESTERN KANSAS
DURING THE LATE AFTERNOON AND EARLY EVENING HOURS. WILL CARRY VCTS
AT THE TAF SITES FOR THAT POSSIBILITY EARLY ON. BETWEEN 03Z AND
06Z, MORE THUNDERSTORMS ARE EXPECTED TO MOVE IN FROM EASTERN
COLORADO SO WILL CARRY A PREVAILING PERIOD OF THUNDERSTORMS AT THE
TAF SITES LATER IN THE EVENING.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 67 89 64 85 / 50 40 70 10
GCK 66 89 64 86 / 50 40 50 10
EHA 66 92 64 87 / 30 20 40 10
LBL 67 91 64 86 / 30 30 60 10
HYS 66 87 64 87 / 50 50 60 10
P28 69 91 68 88 / 30 40 80 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...GERARD
SHORT TERM...GERARD
LONG TERM...FINCH
AVIATION...GERARD
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
203 PM CDT SAT JUN 15 2013
...UPDATED SYNOPSIS AND SHORT TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 202 PM CDT SAT JUN 15 2013
THE 12Z UPPER AIR ANALYSIS SHOWED BROAD RIDGING CONTINUING OVER THE
LOWER 48 STATES. NUMEROUS WEAK SHORTWAVE TROUGHS WERE EMBEDDED IN
THE FLOW OVER THE RIDGE. A STRONGER WAVE EXTENDED FROM OVER
WESTERN KANSAS INTO THE BIG BEND AREA OF SOUTHWEST TEXAS. THIS
WAVE HAD BROUGHT SOME EARLY MORNING SHOWERS AND THUNDERSTORMS TO
WESTERN KANSAS WHICH HAVE SINCE MOVED INTO CENTRAL AND EASTERN
KANSAS BY EARLY AFTERNOON. BEHIND THIS WAVE...SUBSIDENCE WAS
SPREADING ACROSS WESTERN KANSAS AS EVIDENT IN THE WATER VAPOR IMAGERY.
TO THE WEST OF THIS...A WEAK DISTURBANCE WAS MOVING EAST THROUGH
THE CENTRAL ROCKIES. A WEAK FRONTAL BOUNDARY EXTENDED FROM EASTERN
NEBRASKA ACROSS NORTHWEST KANSAS INTO EAST CENTRAL COLORADO. LOW
LEVEL MOISTURE CONTINUES TO STREAM NORTH TOWARD THE CENTRAL PLAINS AS
DEWPOINTS IN THE LOW TO MID 60S ADVECT INTO WESTERN AND CENTRAL KANSAS.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 202 PM CDT SAT JUN 15 2013
IT APPEARS THAT PORTIONS OF WESTERN AND CENTRAL KANSAS COULD HAVE
A DECENT SHOT AT RECEIVING RAIN LATE THIS AFTERNOON INTO
TONIGHT. THE NAM AND GFS MODELS SHOW A TREND OF THUNDERSTORMS
DEVELOPING OVER EASTERN COLORADO AND MOVING INTO WESTERN KANSAS
DURING THE EVENING HOURS. THE HRRR HAS BEEN SHOWING THIS TREND AS
WELL. THE LATEST RUNS OF THAT MODEL ARE SHOWING WIDELY SCATTERED
THUNDERSTORMS DEVELOPING OVER WEST CENTRAL KANSAS LATE THIS
AFTERNOON AND MOVING INTO CENTRAL KANSAS WITH ANOTHER ROUND OF
THUNDERSTORMS THAT DEVELOP OVER EASTERN COLORADO THEN MOVING
ACROSS NORTHWEST AND WEST CENTRAL KANSAS LATER THIS EVENING. THINK
THAT THE TWO AREAS OF STORMS DEPICTED BY THE HRRR MAY BE CORRECT
GIVEN THE LOCATION OF THE FRONTAL BOUNDARY AND INCREASING
INSTABILITY. THE SUBSIDENCE CURRENTLY OVER THE REGION MAY QUASH
ANY LATE AFTERNOON CONVECTION BUT MODEL SOUNDINGS SHOW THE AREA
BECOMING UNCAPPED BY 00Z SO CAN`T TOTALLY RULE OUT A STORM OR TWO.
LATER TONIGHT AM EXPECTING THUNDERSTORMS TO MOVE OUT INTO WEST
CENTRAL AND PARTS OF SOUTHWEST KANSAS. HAVE INCREASED
PRECIPITATION CHANCES TO 50-55 PERCENT ESPECIALLY IN THE AREA
NORTH OF A LINE FROM SYRACUSE THROUGH MONTEZUMA, DODGE CITY AND
LARNED BASED OFF OF TRENDS IN THE HRRR. THE MODELS HINT AT A LOW
LEVEL JET DEVELOPING TONIGHT WHICH COULD HELP SUSTAIN THINGS INTO
THE LATE NIGHT HOURS BUT THINK WE WILL SEE A DECREASING TREND
AFTER 06Z.
SUNDAY SHOULD STAR OUT PARTLY TO MOSTLY SUNNY. ANOTHER WEAK
SHORTWAVE IS PROGGED TO MOVE OUT OF THE ROCKIES DURING THE LATE
AFTERNOON HOURS. HARD TO TELL WHERE EXACTLY THUNDERSTORMS WILL
INITIATE GIVEN THE UNCERTAINTY OF THE FRONTAL POSITION AND THE
POTENTIAL FOR ANY LEFTOVER OUTFLOW BOUNDARIES. WILL CONTINUE THE
PREVIOUS FORECAST TREND OF INCREASING POPS INTO THE CHANCE
CATEGORY BY LATE AFTERNOON. HIGH TEMPERATURES ON SUNDAY MAY ALSO
BE A LITTLE PROBLEMATIC DEPENDING ON HOW MUCH AND WHERE RAINFALL
OCCURS TONIGHT. WILL KEEP HIGHS IN THE UPPER 80S TO NEAR 90 IN
MOST AREAS WITH SOME LOW 90S OUT ALONG THE COLORADO BORDER.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 220 AM CDT SAT JUN 15 2013
AN ACTIVE PATTERN IS EXPECTED THIS WEEKEND INTO THE FIRST HALF OF
NEXT WEEK AS A SERIES OF UPPER LEVEL DISTURBANCES MOVE AROUND THE
PERIPHERY OF A WEAK UPPER LEVEL RIDGE OF HIGH PRESSURE POSITIONED
ACROSS NORTHERN MEXICO AND THE SOUTHERN PLAINS. THIS WILL BRING
CHANCES OF THUNDERSTORMS TO THE FORECAST AREA SUNDAY THROUGH
WEDNESDAY. THE BEST CHANCE OF PRECIPITATION WILL BE SUNDAY NIGHT
INTO MONDAY AS MODELS DEPICT AN MCS TO DEVELOP ACROSS EASTERN
COLORADO AND MOVE ACROSS WESTERN KANSAS. SPC HAS PLACED A SLIGHT
RISK OF SEVERE STORMS ACROSS THE AREA FOR SUNDAY WITH LARGE HAIL AND
DAMAGING WINDS BEING THE MAIN CONCERN. THUNDERSTORM CHANCES WILL
CONTINUE THROUGH WEDNESDAY, MAINLY ACROSS WESTERN PORTIONS OF THE
FORECAST AREA. OTHERWISE PARTLY CLOUDY SKIES WILL BE OBSERVED. WINDS
THROUGHOUT THIS PERIOD WILL GENERALLY BE FROM THE EAST TO NORTHEAST
SUNDAY THROUGH MONDAY SHIFTING TO MORE OF A SOUTHERLY DIRECTION
TUESDAY AND WEDNESDAY. HIGHS DURING THIS PERIOD WILL GENERALLY BE IN
THE 80S WITH THE EXCEPTION OF SUNDAY WHERE LOWER 90S WILL BE FOUND
ACROSS THE KS/OK BORDER. LOWS WILL GENERALLY BE IN THE 60S.
A DRIER WEATHER PATTERN IS FORECASTED FOR THE REMAINDER OF THE
FORECAST AS UPPER LEVEL RIDGING BUILDS ACROSS THE PLAINS WITH AN
UPPER LEVEL TROUGH OF LOW PRESSURE DIGGING INTO THE WESTERN UNITED
STATES. THIS TROUGH WILL IN TURN ALLOW LEE TROUGHING TO CONTINUE
ACROSS EASTERN COLORADO WITH SOUTHERLY WINDS OBSERVED ACROSS WESTERN
KANSAS. WARMER TEMPERATURES ARE EXPECTED DURING THIS TIME FRAME WITH
HIGHS IN THE UPPER 90S AND LOWS IN THE LOWER 70S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1250 PM CDT SAT JUN 15 2013
VFR CONDITIONS WILL PREVAIL ACROSS SOUTHWEST AND CENTRAL KANSAS
THROUGH THE FIRST PART OF THIS TAF PERIOD. WIDELY SCATTERED
THUNDERSTORMS ARE EXPECTED TO DEVELOP ACROSS WESTERN KANSAS ALONG
A WEAK FRONTAL BOUNDARY AND SHOULD MOVE THROUGH WESTERN KANSAS
DURING THE LATE AFTERNOON AND EARLY EVENING HOURS. WILL CARRY VCTS
AT THE TAF SITES FOR THAT POSSIBILITY EARLY ON. BETWEEN 03Z AND
06Z, MORE THUNDERSTORMS ARE EXPECTED TO MOVE IN FROM EASTERN
COLORADO SO WILL CARRY A PREVAILING PERIOD OF THUNDERSTORMS AT THE
TAF SITES LATER IN THE EVENING.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 67 89 64 85 / 50 40 50 20
GCK 66 89 64 86 / 50 40 50 30
EHA 66 92 64 87 / 30 20 20 30
LBL 67 91 64 86 / 30 30 50 30
HYS 66 87 64 87 / 50 50 70 10
P28 69 91 68 88 / 30 40 90 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...GERARD
SHORT TERM...GERARD
LONG TERM...HOVORKA_42
AVIATION...GERARD
AREA FORECAST DISCUSSION
NWS GRAY ME
1200 AM EDT MON JUN 17 2013
.SYNOPSIS...
A WEAK AREA OF LOW PRESSURE WILL CROSS THE REGION THIS EVENING BRINGING
WIDESPREAD SHOWERS TO MOUNTAINS AND FOOTHILLS AND SCATTERED
SHOWERS ALONG THE COAST. A COLD FRONT ASSOCIATED WITH ANOTHER
AREA OF LOW PRESSURE PASSING TO OUR NORTH MONDAY WILL TRIGGER
SHOWERS AND THUNDERSTORMS ACROSS THE AREA MONDAY AFTERNOON. THE
FRONT WILL MOVE OFF THE COAST TUESDAY MORNING. HIGH PRESSURE WILL
BUILD IN FOR THE MIDDLE AND LATTER PART OF THE WEEK.
&&
.NEAR TERM /OVERNIGHT/...
MIDNIGHT UPDATE...
HAVE MADE ADJUSTMENTS PRIMARILY TO POP GRIDS TO REFLECT THE FACT
THAT SHOWERS HAVE ENDED ACROSS THE AREA. MORE SHOWERS AND A FEW
EMBEDDED THUNDERSTORMS ARE DRIFTING ACROSS THE CANADIAN BORDER
INTO VERMONT AND MAY MOVE INTO NEW HAMPSHIRE AND NORTHWEST MAINE
OVER THE NEXT FEW HOURS. WITH DEW POINTS IN THE MID TO UPPER
50S... TEMPERATURES WILL NOT FALL MUCH OVERNIGHT AND HAVE RAISED
MINIMUM TEMPERATURES IN THE MOUNTAIN VALLEYS.
PREVIOUS UPDATE...
HAVE UPDATED GRIDDED FORECAST BASED ON CURRENT CONDITIONS. LATEST
RADAR ANIMATIONS CONTINUE TO SHOW SCATTERED SHOWERS OVER EASTERN
AREAS BEGINNING TO EXIT NEAR THE PENOBSCOT VALLEY REGION AND
WESTERN MOUNTAINS OF MAINE. WHILE SOME OF THIS IS DRYING UP WITH
EVAPORATIVE COOLING...RAIN IS REACHING THE GROUND IN SOME AREAS. HAVE
LOWERED POPS FOR SOUTHERN AND WESTERN COUNTIES...AND ADDED PATCHY
FOG FOR MUCH OF THE REGION OVERNIGHT.
WILL CONTINUE TO USE THE HRRR FOR THE TIMING OF THE EXITING
PRECIPITATION FIELDS.
PREVIOUS DISCUSSION...
AREA OF SHOWERS CONTINUES TO MOVE EAST FROM NY STATE THIS
AFTERNOON. MUCH OF THE INITIAL PRECIPITATION HAS BEEN EVAPORATING
BEFORE REACHING THE GROUND, ESPECIALLY IN SOUTHERN AREAS. AIR
OVER MOUNTAINS AND FOOTHILLS SHOULD SATURATE...SO EXPECT
WIDESPREAD RAIN IN THOSE AREAS THIS EVENING. ELSEWHERE...EXPECT
ONLY SCATTERED SHOWERS TO REACH THE GROUND AS AIR IS VERY DRY.
PATCHY FOG EXPECTED OVERNIGHT IN AREAS THAT GET A SHOWER THIS
EVENING.
&&
.SHORT TERM /MONDAY AND MONDAY NIGHT/...
FRONTAL BOUNDARY APPROACHES FROM THE WEST MONDAY WITH INCREASING
MOISTURE AND TEMPERATURES. AHEAD OF THE FRONT...TEMPERATURES IN
SOUTHERN AREAS COULD REACH THE MID 80S. ATMOSPHERE BECOMES A BIT
UNSTABLE AHEAD OF THE FRONT BRINGING THE THREAT OF SHOWERS AND
THUNDERSTORMS TO THE AREA MONDAY AFTERNOON AND EVENING. FRONT
MOVES VERY THROUGH REGION WITH SHOWER THREAT CONTINUING MONDAY
NIGHT.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
FAIRLY QUIET EXTENDED PERIOD IN STORE. SHOULD BE A WEAK BOUNDARY
DRAPED ACROSS THE REGION TUESDAY MORNING THAT COULD PROVIDE A
FOCUS FOR SOME AFTERNOON CONVECTION. THE BOUNDARY IS EXPECTED TO
MOVE OFFSHORE TUESDAY NIGHT AS HIGH PRESSURE BUILDS IN FROM THE
WEST. HIGH PRESSURE THEN REMAINS IN PLACE ACROSS NORTHERN NEW
ENGLAND UNTIL AT LEAST FRIDAY. CYCLONIC FLOW ALOFT SETS UP OVER
THE REGION FRIDAY NIGHT. THE GFS IS TRYING TO DROP A WEAK BACK
DOOR COLD FRONT OUT OF CANADA FRIDAY NIGHT AND INTO SATURDAY BUT
APPEARS TO BE THE OUTLIER. WILL NOT GIVE IT TOO MUCH WEIGHT YET
BUT IT WILL REMAIN A FEATURE TO LOOK FOR OVER THE NEXT FEW DAYS.
&&
.AVIATION /04Z MONDAY THROUGH FRIDAY/...
SHORT TERM...MVFR CONDITIONS POSSIBLE TONIGHT IN SHOWERS AND IFR
CONDITIONS POSSIBLE IN PATCHY FOG OVERNIGHT. MVFR TO IFR
CONDITIONS POSSIBLE IN SHOWERS AND THUNDERSTORMS MONDAY AFTERNOON
AND NIGHT.
LONG TERM...VFR CONDITIONS EXPECTED THROUGHOUT THE PERIOD.
&&
.MARINE...
SHORT TERM...WINDS AND SEAS EXPECTED TO BE BELOW SCA CRITERIA.
LONG TERM...NO FLAGS EXPECTED.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
NEAR TERM UPDATE... KIMBLE
AREA FORECAST DISCUSSION
NWS GRAY ME
927 PM EDT SUN JUN 16 2013
.SYNOPSIS...
A WEAK AREA OF LOW PRESSURE WILL CROSS THE REGION THIS EVENING BRINGING
WIDESPREAD SHOWERS TO MOUNTAINS AND FOOTHILLS AND SCATTERED
SHOWERS ALONG THE COAST. A COLD FRONT ASSOCIATED WITH ANOTHER
AREA OF LOW PRESSURE PASSING TO OUR NORTH MONDAY WILL TRIGGER
SHOWERS AND THUNDERSTORMS ACROSS THE AREA MONDAY AFTERNOON. THE
FRONT WILL MOVE OFF THE COAST TUESDAY MORNING. HIGH PRESSURE WILL
BUILD IN FOR THE MIDDLE AND LATTER PART OF THE WEEK.
&&
.NEAR TERM /THROUGH MONDAY/...
UPDATE...
HAVE UPDATED GRIDDED FORECAST BASED ON CURRENT CONDITIONS. LATEST
RADAR ANIMATIONS CONTINUE TO SHOW SCATTERED SHOWERS OVER EASTERN
AREAS BEGINNING TO EXIT NEAR THE PENOBSCOT VALLEY REGION AND
WESTERN MOUNTAINS OF MAINE. WHILE SOME OF THIS IS DRYING UP WITH
EVAP COOLING...RAIN IS REACHING THE GROUND IN SOME AREAS. HAVE
LOWERED POPS FOR SOUTHERN AND WESTERN COUNTIES...AND ADDED PATCHY
FOG FOR MUCH OF THE REGION OVERNIGHT.
WILL CONTINUE TO USE THE HRRR FOR THE TIMING OF THE EXITING PCPN
FIELDS.
PREV DISC...
AREA OF SHOWERS CONTINUES TO MOVE EAST FROM NY STATE THIS
AFTERNOON. MUCH OF THE INITIAL PRECIP HAS BEEN EVAPORATING BEFORE
REACHING THE GROUND, ESPECIALLY IN SOUTHERN AREAS. AIR OVER MOUNTAINS
AND FOOTHILLS SHOULD SATURATE...SO EXPECT WIDESPREAD RAIN IN
THOSE AREAS THIS EVENING. ELSEWHERE...EXPECT ONLY SCATTERED
SHOWERS TO REACH THE GROUND AS AIR IS VERY DRY. PATCHY FOG
EXPECTED OVERNIGHT IN AREAS THAT GET A SHOWER THIS EVENING.
&&
.SHORT TERM /MONDAY NIGHT/...
FRONTAL BOUNDARY APPROACHES FROM THE WEST MONDAY WITH INCREASING
MOISTURE AND TEMPERATURES. AHEAD OF THE FRONT...TEMPS IN SOUTHERN
AREAS COULD REACH THE MID 80S. ATMOSPHERE BECOMES A BIT UNSTABLE
AHEAD OF THE FRONT BRINGING THE THREAT OF SHOWERS AND
THUNDERSTORMS TO THE AREA MONDAY AFTERNOON AND EVENING. FRONT
MOVES VERY THROUGH REGION WITH SHOWER THREAT CONTINUING MONDAY
NIGHT.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
FAIRLY QUIET EXTENDED PERIOD IN STORE. SHOULD BE A WEAK BOUNDARY
DRAPED ACROSS THE REGION TUESDAY MORNING THAT COULD PROVIDE A
FOCUS FOR SOME AFTERNOON CONVECTION. THE BOUNDARY IS EXPECTED TO
MOVE OFFSHORE TUESDAY NIGHT AS HIGH PRESSURE BUILDS IN FROM THE
WEST. HIGH PRESSURE THEN REMAINS IN PLACE ACROSS NORTHERN NEW
ENGLAND UNTIL AT LEAST FRIDAY. CYCLONIC FLOW ALOFT SETS UP OVER
THE REGION FRIDAY NIGHT. THE GFS IS TRYING TO DROP A WEAK BACK
DOOR COLD FRONT OUT OF CANADA FRIDAY NIGHT AND INTO SATURDAY BUT
APPEARS TO BE THE OUTLIER. WILL NOT GIVE IT TOO MUCH WEIGHT YET
BUT IT WILL REMAIN A FEATURE TO LOOK FOR OVER THE NEXT FEW DAYS.
&&
.AVIATION /01Z MONDAY THROUGH FRIDAY/...
SHORT TERM...MVFR CONDITIONS POSSIBLE TONIGHT IN SHOWERS AND IFR
CONDITIONS POSSIBLE IN PATCHY FOG OVERNIGHT. MVFR TO IFR
CONDITIONS POSSIBLE IN SHOWERS AND THUNDERSTORMS MONDAY AFTERNOON
AND NIGHT.
LONG TERM...VFR CONDITIONS EXPECTED THROUGHOUT THE PERIOD.
&&
.MARINE...
SHORT TERM...WINDS AND SEAS EXPECTED TO BE BELOW SCA CRITERIA.
LONG TERM...NO FLAGS EXPECTED.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
714 PM EDT SUN JUN 16 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 411 PM EDT SUN JUN 16 2013
THE MAIN CONCERN FOR THE SHORT TERM FORECAST WILL BE THE ONGOING
SHOWERS AND THUNDERSTORMS AND ADDITIONAL SHOWERS WITH THE TROUGH
DROPPING SOUTH ACROSS THE AREA TONIGHT. INITIAL CONVECTION WAS OVER
EASTERN UPPER MICHIGAN...WHERE THERE WAS INCREASED MOISTURE FROM THE
FOG EARLIER TODAY AND CONVERGENCE FROM WEAK LAKE BREEZES. THESE
INITIAL SHOWERS HAVE SHIFTED TO THE SOUTHEAST AND OUT OF THE
CWA...BUT ARE SEEING SOME SHOWERS IN CENTRAL UPPER MICHIGAN ALONG
THE LAKE SUPERIOR LAKE BREEZE. THESE SHOWERS HAVE BEEN LIMITED THUS
FAR DUE TO THE DRY MID LEVEL AIR EVEN THOUGH THERE IS STRONG
LOW LEVEL LAPSE RATES AND RAP ANALYZED SB CAPE VALUES OF
500-1000 J/KG. BUT WITH THE INVERTED V LOOK TO THE RAP
SOUNDINGS...ML CAPES ARE STRUGGLING TO GET MUCH ABOVE 250-500 J/KG.
THIS DRY AIR CAN ALSO BE SEEN IN THE DEWPOINTS /UPPER 40S/ AWAY
FROM THE INFLUENCE OF THE GREAT LAKES. THERE HAVE EVEN BEEN SOME
SIGNIFICANT JUMPS IN THE DEWPOINTS OVER THE EASTERN CWA...AS THE
LAKE BREEZES HAVE MOVED IN AND OUT OF SOME OF THE SITES. FARTHER
WEST...A PERSISTENT SHOWER/THUNDERSTORM CLUSTER MOVED INTO WESTERN
GOGEBIC COUNTY OVER THE LAST HOUR AND DID PRODUCE SOME GUSTS UP TO
40KTS EVEN THOUGH THE CLUSTER IS DIMINISHING. THIS ISN/T TOO
UNREASONABLE WITH CURRENT DCAPE VALUES OVER MUCH OF UPPER MICHIGAN
AROUND 800-1000 J/KG AND THE INVERTED V SOUNDINGS. WOULD EXPECT
THIS TO BE THE PRIMARY CONCERN FOR ANY SHOWERS/THUNDERSTORMS LATE
THIS AFTERNOON AND EVENING. FINALLY...ADDITIONAL
SHOWERS/THUNDERSTORMS HAVE BEEN ONGOING JUST NORTHEAST OF LAKE
SUPERIOR...DUE TO ONE PIECE OF SHEARED OFF UPPER LEVEL ENERGY
DROPPING SOUTHEAST ALONG THE TROUGH. THESE SHOWERS WILL CONTINUE
QUICKLY SOUTHEAST AS THE STORM MOTION IS AROUND 40KTS.
THE AREA THAT WILL BRING THE BEST CHANCE FOR SHOWERS IS THE
REMNANT SHORTWAVE FROM THE UPPER LOW THAT WAS IN CENTRAL
SASKATCHEWAN YESTERDAY. THIS SHORTWAVE HAS STARTED TO MOVE TOWARDS
THE CANADA/ND/MN BORDER AND HAS SPARKED SHOWERS AND THUNDERSTORMS
ALONG THE SURFACE TROUGH WHERE THERE IS DEEPER MOISTURE. WITH THE
STORM MOTION TO THE SOUTHEAST AROUND 30-35KTS AND THE TROUGH SLOWLY
SAGGING SOUTHEAST...WOULD EXPECT THOSE SHOWERS TO MOVE SOUTHEAST
ACROSS WESTERN/CENTRAL UPPER MICHIGAN LATE THIS AFTERNOON AND INTO
THE EVENING HOURS. NOT ENTIRELY CONFIDENT ON THE EASTERN CWA...AS
IT WILL DEPEND ON THE THUNDERSTORMS CURRENTLY MOVING SOUTHEAST
FROM THUNDER BAY AND HOW FAR SOUTHEAST THEY WILL MAKE IT BEFORE
DIMINISHING. WILL HAVE LOWER POPS THAN OVER THE WEST...BUT STILL
IN THE LOW END CHANCE CATEGORY. AN EARLIER UPDATE COVERED THE
TIMING WELL OVER THE WEST AND HAVE JUST MADE MINOR TWEAKS TO
MATCH THE CURRENT CONDITIONS...WITH MOST AREAS IN THE HIGHER REACHES
OF THE SCATTERED/CHANCE CATEGORY. THINK THERE IS A DECENT SHOT MOST
LOCATIONS WILL SEE RAIN...BUT THE COVERAGE/TIMING WOULD BE BETTER
REFLECTED IN THE SCATTERED WORDING. AS MENTIONED ABOVE...THE DRY
AIR AND LIMITED INSTABILITY WILL BE THE MAIN LIMITING FACTORS TO
THE THUNDERSTORMS AND THEIR SEVERE POTENTIAL. BEST THREAT WILL BE
WEST-SOUTHWEST OF THE CWA WHERE THE 850-700/500MB LAPSE RATES ARE
THE STEEPEST...BUT THERE COULD BE SOME STRONGER STORMS OVER THE
SOUTHWEST THIRD OF THE CWA. HAIL POTENTIAL WILL BE LIMITED DUE TO
THE LIMITED INSTABILITY AND TALL/SKINNY CAPE. AS MENTIONED
ABOVE...GUSTY WINDS WILL BE THE BIGGEST THREAT OVER THE SW
HALF OF THE CWA...AS THEY HAVE THE STEEPER MID LEVEL LAPSE
RATES...COMBINED WITH THE DRY LOW LEVELS TO PRODUCE THE HIGHER
DCAPE VALUES.
THEN...AS THE SHORTWAVE TRACKS SOUTHEAST INTO NORTHWEST WISCONSIN
TONIGHT AND THE REST OF NORTHERN WISCONSIN ON MONDAY
MORNING...WOULD EXPECT SCATTERED SHOWERS TO CONTINUE THROUGH THE
NIGHT OVER THE SOUTHWEST HALF OF THE CWA. THAT IS ALSO WHERE
THE BEST 850-500MB Q-VECTOR CONV IS LOCATED EVEN THOUGH THE DEEPER
MOISTURE IS OVER EASTERN UPPER MICHIGAN. HAVE SLOWLY DIMINISHED THE
THUNDER THREAT OVERNIGHT AND INTO MONDAY MORNING TO BE OVER THE
SOUTHERN PART OF THE CWA...WHERE THE BETTER FORCING IS LOCATED. WILL
HOLD ON TO SOME LIGHT RAIN SHOWERS OVER NORTHERN UPPER MICHIGAN
OVERNIGHT TONIGHT AND INTO TOMORROW MORNING...AS LOW LEVEL
CONVERGENCE INCREASES WITH THE WINDS SHIFTING TO THE
NORTH-NORTHEAST. WITH DECENT MOISTURE BELOW 10KFT AS THAT
CONVERGENCE OCCURS...THINKING THERE WILL BE ENOUGH TO PRODUCE SOME
SHOWERS...ESPECIALLY OVER SOME OF THE HIGHER TERRAIN LOCATIONS OF
NORTH CENTRAL UPPER MICHIGAN WHERE THE WINDS BECOME UPSLOPE FOR A
PERIOD OF TIME.
THE LARGER SCALE FORCING SHOULD DEPART THE SOUTHWEST AND SOUTH
CENTRAL CWA AROUND DAYBREAK AND THEY WILL BE LEFT WITH ANY SHOWERS
DROPPING SOUTH ALONG THE ENHANCED CONVERGENCE. BEHIND THE
TROUGH...LOW CLOUDS SEEN IN CENTRAL ONTARIO/MANITOBA THIS MORNING
WILL MOVE SOUTH ACROSS THE CWA LATE TONIGHT INTO TOMORROW MORNING.
MODELS STRUGGLING WITH HOW LOW THE CLOUDS WILL BE...BUT EITHER WAY
A CLOUDY START TO THE WORK WEEK IS EXPECTED. CANADIAN HIGH PRESSURE
IS EXPECTED TO BUILD OVER THE AREA ON MONDAY AFTERNOON...BRINGING
DRIER AIR AND SUBSIDENCE TO THE AREA IN THE AFTERNOON. THIS WILL
PRODUCE DECREASING CLOUDS FROM NORTH TO SOUTH. HIGHS WILL BE MUCH
COOLER TOMORROW...WITH 60S IN MOST LOCATIONS EXCEPT NEAR LAKE
SUPERIOR WHERE NORTHERLY FLOW OFF THE LAKE WILL KEEP HIGHS IN THE
UPPER 50S.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 411 PM EDT SUN JUN 16 2013
THROUGH THE MIDDLE OF THE WEEK...NW FLOW WILL PREVAIL INTO THE UPPER
GREAT LAKES BTWN A RIDGE DRIFTING FROM THE ROCKIES TO THE PLAINS AND
A BROAD TROF OVER ERN NAMERICA. AS THE RIDGE SHIFTS TO THE
MISSISSIPPI VALLEY/GREAT LAKES LATE WEEK...IT WILL LOOSE AMPLITUDE
AS SHORTWAVE ENERGY EJECTING E FROM A TROF OVER THE NW CONUS BEGINS
TO SUPPRESS THE RIDGE. THE NW FLOW EARLY ON WILL SUPPORT DRY WEATHER
FOR UPPER MI. MOVING INTO THE LATE WEEK PERIOD...PATTERN SHOULD
BECOME ACTIVE WITH DECENT PCPN PROSPECTS AS SHORTWAVES TRACK E
ACROSS THE NRN PLAINS TO THE GREAT LAKES. AS FOR TEMPS...COOLEST
WEATHER WILL OCCUR OVER THE NEXT DAY OR TWO BEHIND SHORTWAVE PASSING
TONIGHT/MON. THEN...DESPITE NW FLOW...TEMPS THRU THE MIDWEEK PERIOD
SHOULD BE CLOSE TO NORMAL OR EVEN A LITTLE ABOVE NORMAL SINCE ERN
TROF WILL NOT HAVE SIGNIFICANT AMPLITUDE INTO THE ERN CONUS...
RESULTING IN COOLER AIR STAYING E AND NE OF THE AREA. TEMPS LATE
WEEK INTO THE WEEKEND WILL BE ABOVE NORMAL WITH WARMER/MORE HUMID
CONDITIONS. COULD BE UNCOMFORTABLY HUMID FOR A DAY OR TWO.
BEGINNING MON NIGHT...A CHILLY NIGHT IS ON THE WAY AS HIGH PRES
BUILDS INTO THE UPPER LAKES. WITH VERY DRY COLUMN (PRECIPITABLE
WATER 30-50PCT OF NORMAL) AND WINDS DIMINISHING TO LIGHT/CALM...WILL
CONTINUE TO FAVOR THE LOW END OF MODEL GUIDANCE FOR MIN TEMPS...
ESPECIALLY OVER THE W WHERE SFC HIGH PRES CENTER WILL BE ARRIVING
DURING THE NIGHT. WITH IDEAL RADIATIONAL COOLING CONDITIONS...THERE
IS A GOOD POTENTIAL FOR SOME FROST IN THE USUAL COLDER AREAS.
SOME OF THE TRADITIONAL COLD SPOTS COULD FALL TO NEAR FREEZING.
RECORD LOW FOR NWS MQT SITE ON THE 18TH IS 38F. NOT OUT OF THE
QUESTION THAT RECORD COULD BE TIED OR BROKEN.
SFC HIGH PRES WILL BE SETTLED OVER THE UPPER LAKES TUE...PROVIDING A
DRY/PLEASANT MID JUNE DAY WITH ABUNDANT SUNSHINE UNDER LINGERING
VERY DRY COLUMN. LAKE BREEZES WILL BE THE RULE...KEEPING LAKESIDE
LOCATIONS COOLER IN THE AFTN. GIVEN AVBL DRY AIR TO MIX DOWN...DWPTS
SHOULD FALL TO THE MID 30S...POSSIBLY LOWER...IN THE INTERIOR...
RESULTING IN MIN RH DOWN AROUND 25PCT. WOULDN`T BE SURPRISED TO SEE
SOME LOCATIONS FALL TO AROUND 20PCT. FORTUNATELY...LIGHT WINDS WILL
KEEP FIRE WX CONCERNS IN CHECK.
MEDIUM RANGE GUIDANCE HAS AND STILL CONTINUES TO HINT THAT A
SHORTWAVE WILL DROP SE...PASSING JUST N OF UPPER MI LATE WED/WED
NIGHT. GIVEN THE FAIRLY CONSISTENT SIGNAL FROM ALL MEDIUM RANGE
GUIDANCE...IT STILL APPEARS THERE MAY BE SOME PCPN AT SOME POINT
LATE WED/WED NIGHT. NOTHING MORE THAN SCHC/LOW CHC POPS ARE
WARRANTED SINCE BETTER FORCING PASSES BY TO THE N AND SINCE COVERAGE
WILL BE LOW IF PCPN DOES OCCUR. IF WAVE IS FASTER AND ARRIVES DURING
PEAK HEATING WED...PCPN CHC WILL BE GREATER...BUT WOULD STILL NOT
EXPECT ANYTHING MORE THAN SCT COVERAGE.
ON THU...THERE IS THE POTENTIAL FOR SUBTLE BOUNDARY ASSOCIATED WITH
THE SHORTWAVE PASSING BY THE AREA WED NIGHT TO HANG UP OVER/NEAR
UPPER MI...AND THAT COULD BE THE FOCUS FOR SOME CONVECTION THU AFTN.
MAINTAINED SCHC/LOW CHC POPS IN FCST.
AS MENTIONED EARLIER...THE LATE WEEK PERIOD INTO THE WEEKEND COULD
BECOME ACTIVE AS SHORTWAVES TRACK ACROSS THE NRN CONUS TO THE GREAT
LAKES...SUPPRESSING THE RIDGE THAT WAS SHIFTING ACROSS THE PLAINS
TOWARD THE AREA. SIGNAL LOOKS STRONG ENOUGH TO WARRANT AT LEAST MID
RANGE CHC POPS FOR SHRA/TSRA FOR PORTIONS OF FRI/SAT. SFC HIGH PRES
MAY BEGIN TO BUILD S TOWARD THE UPPER LAKES SUN IN THE WAKE OF A
SHORTWAVE SWINGING ACROSS HUDSON BAY/QUEBEC...SO PCPN CHANCES MAY
DIMINISH ON SUN. OVERALL...THERE APPEARS TO BE DECENT POTENTIAL THAT
MOST LOCATIONS WILL SEE SOME RAIN AT SOME POINT BTWN FRI AND SUN.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 713 PM EDT SUN JUN 16 2013
AN UPPER LEVEL DISTURBANCE WILL COMBINE WITH A SURFACE TROUGH
DROPPING SOUTH ACROSS LAKE SUPERIOR TO PRODUCE SHOWERS AND SOME
THUNDERSTORMS FOR ALL TAF SITES INTO TONIGHT. AS THE DISTURBANCE
NEARS OVER THE NEXT FEW HOURS...THE POTENTIAL FOR SHOWERS WILL BE ON
THE INCREASE. FELT CONFIDENT ENOUGH WITH A LINE OF
SHOWERS/THUNDERSTORMS NEARING DULUTH TO MENTION THUNDER AT
KIWD...BUT LEFT OUT OTHERWISE. THE SCATTERED SHOWERS/THUNDERSTORMS
WILL SPREAD SOUTHEAST THROUGH THE REST OF THE EVENING...AS THE FRONT
AND SHORTWAVE PASS THROUGH THE AREA. EXPECT THE THUNDER THREAT TO
DIMINISH AND SLIDE SOUTH OVERNIGHT. MEANWHILE...LIGHT NORTHERLY FLOW
BEHIND THE SFC TROUGH WILL TRY TO PULL LOW CLOUDS INTO THE AREA.
THESE CLOUDS HAVE BEEN SEEN OVER SOUTHERN ONTARIO TODAY...BUT THE
MODELS HAVE BEEN VARYING ON IF THEY WILL OCCUR LATE TONIGHT INTO
TOMORROW MORNING. SINCE IT IS LATER IN THE PERIOD...OPTED TO PLAY
THE MIDDLE GROUND AT THIS POINT /MVFR CEILINGS/ BUT IFR OR LOWER
CEILINGS/VISIBILITY IS POSSIBLE AT KCMX/KSAW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 411 PM EDT SUN JUN 16 2013
WINDS ARE EXPECTED TO STAY BELOW 20KTS THROUGH THE PERIOD. A TROUGH
WILL DROP SOUTH ACROSS LAKE SUPERIOR THIS EVENING...LEADING TO WINDS
SHIFTING TO THE NORTH TONIGHT. AS THE TROUGH CONTINUES SOUTHEAST ON
MONDAY...HIGH PRESSURE WILL BUILD OVER THE UPPER GREAT LAKES AND
REMAIN THROUGH WEDNESDAY. A WEAK TROUGH WILL THEN APPROACH THE AREA
FROM THE NORTHWEST FOR THURSDAY. THERE IS A POCKET OF FOG OVER
EASTERN LAKE SUPERIOR /NEAR AND EAST OF GRAND MARAIS MI/ THAT HAS
BEEN DIMINISHING AND MOVING AROUND TODAY. WOULD EXPECT THE DRY AIR
TO CONTINUE TO EAT AWAY AT IT THIS EVENING...BUT THERE IS SOME
CONCERN IT COULD EXPAND WITH RAIN OCCURRING OVER CENTRAL LAKE
SUPERIOR THIS AFTERNOON/EVENING AND LINGER THROUGH THE NIGHT. IF FOG
DOES LINGER TONIGHT...IT WILL CLEAR OUT MON MORNING AS MUCH DRIER AIR
SURGES S INTO THE UPPER LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...ROLFSON
AVIATION...07
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
434 PM EDT SAT JUN 15 2013
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 432 PM EDT SAT JUN 15 2013
WEAKENING UPPER RIDGE AXIS IS STILL OVER THE WESTERN GREAT
LAKES...WHILE A LARGE UPPER LOW IS SPINNING OVER CENTRAL
SASKATCHEWAN. THERE AREA A COUPLE SUBTLE DISTURBANCES ROUNDING THE
RIDGE. THE FIRST ONE IS CURRENTLY EXITING EASTERN UPPER MICHIGAN.
THIS WAVE COMBINED WITH BROAD WARM AIR ADVECTION TO PRODUCE
THE SHOWERS THIS MORNING OVER THE WEST AND THEN THE DIMINISHING
SHOWERS OVER THE EAST THIS AFTERNOON. THE NEXT WAVE IS CURRENTLY
ASSOCIATED WITH THE CONVECTION IN NORTHERN IOWA AND SOUTHERN
MINNESOTA AND MOVING TO THE EAST-NORTHEAST. AT THE SURFACE...A
TROUGH IS CURRENTLY STRETCHING SOUTH ACROSS EASTERN MINNESOTA FROM
THE LOW IN CENTRAL SASKATCHEWAN. POCKET OF MLCAPE VALUES AROUND
1000 J/KG IS LOCATED AHEAD OF THIS TROUGH IN WESTERN WISCONSIN AND
STARTING TO NOSE NORTHEAST INTO WESTERN UPPER MICHIGAN. SHOWERS AND
THUNDERSTORMS HAVE STARTED TO DEVELOP NORTH OF THE TWIN CITIES...AS
HINTED AT BY MORNING RUNS OF THE HRRR...AND HAVE BEEN LIFTING
NORTHEAST.
FOR THE REST OF THIS AFTERNOON AND TONIGHT THE FORECAST DEPENDS ON
TWO FEATURES...THE TROUGH MOVING THROUGH THE U.P. THIS EVENING AND
THE SHORTWAVE ASSOCIATED WITH THE DECAYING CONVECTION IN SOUTHEAST
MN. THEY BOTH SEEM TO BE INTERACTING OVER THE LAST COUPLE OF HOURS
WITH THE DEVELOPMENT OF THUNDERSTORMS NORTH OF THE TWIN CITIES AND
INTO WEST CENTRAL WISCONSIN. AS INDICATED BY THE HRRR THIS
MORNING...WOULD EXPECT THESE THUNDERSTORMS TO CONTINUE DEVELOP AND
PUSH NORTHEAST INITIALLY BEFORE THE STORM MOTIONS TAKE THEM MORE
EASTERLY AS IT ROUNDS THE RIDGE. ML CAPES SHOULD CONTINUE TO PUSH
NORTHEAST TOWARDS THE WISCONSIN BORDER...AS THE LOW CLOUDS BEGIN TO
THIN AND INCREASE HEATING. THE ONE CONCERN WILL BE THE THICKENING
HIGH CLOUDS ON THE NORTH SIDE OF THE CONVECTION MAY BE ENOUGH TO
LIMIT THE NORTHWARD EXTENT OF THE INSTABILITY. WITH THE SHORTWAVE
ALSO ROUNDING THE RIDGE...THAT SHOULD FOCUS THE BEST FORCING ACROSS
CENTRAL WISCONSIN. THEREFORE...WOULD EXPECT THE BEST CHANCE FOR
SHOWERS AND THUNDERSTORMS LATE THIS AFTERNOON AND EVENING OVER THE
SOUTHERN HALF OF THE CWA...ESPECIALLY NEAR THE WISCONSIN BORDER
WHERE THE BEST INSTABILITY WILL BE LOCATED AND STORM MOTION WOULD
TRACK THE THUNDERSTORMS. AT THIS POINT...WOULD EXPECT HEAVY RAIN TO
BE THE MAIN THREAT SINCE NCAPE SHOULD REMAIN BELOW 0.1 AND DCAPE
VALUES STRUGGLE TO RISE ABOVE 700 J/KG AS THE LOW CLOUDS OVER THE
SOUTHWEST DISSIPATE.
FARTHER NORTHWEST...THE UPPER LOW SPINNING IN CENTRAL SASKATCHEWAN
WILL LIKELY SPARK SOME SHOWERS AND THUNDERSTORMS ALONG THE
MN/ND/CANADA BORDER THIS AFTERNOON WHICH WILL TRACK EAST THIS
EVENING. WITH THE LOSS OF DIURNAL HEATING...WOULD EXPECT THEM TO
DIMINISH AS THEY APPROACH NORTHERN LAKE SUPERIOR. BUT WITH THE
CLOSE PROXIMITY OF THE UPPER LEVEL SHORTWAVES...DEEPER MOISTURE AND
STEEPER LAPSE RATES...WILL HOLD ONTO SLIGHT CHANCE POPS AS THAT
MOVES ACROSS THE NORTHERN LAKE TONIGHT.
OTHERWISE...ONCE THE THE TROUGH AND CONVECTION SLIDE THROUGH...DRY
MID LEVEL AIR WILL SURGE OVER THE AREA AND LEAD TO A FAIRLY QUIET
NIGHT WITH DECREASING CLOUDS FROM WEST TO EAST. WITH THE MOIST
SOUTHERLY FLOW OFF LAKE MICHIGAN AND THE POTENTIAL FOR SOME FOG OFF
THE LAKE WITH THE SHOWERS UPSTREAM...HAVE ADDED IN FOG OVER EASTERN
UPPER MICHIGAN. ALSO ADDED A MENTION OVER CENTRAL/EASTERN LAKE
SUPERIOR...ALONG WITH THE KEWEENAW...SINCE THERE IS A DENCENT
CONSISTENCY IN THE MODELS AND THERE ARE 50S AND LOW 60S DEWPOINTS
MOVING OVER WESTERN/CENTRAL LAKE SUPERIOR THIS AFTERNOON.
UNFORTUNATELY...CLOUDS HAVE OBSCURED THE LAKE TO SEE IF ANY FOG IS
GOING...BUT SHIP OBS HAVE YET TO REPORT FOG.
EXPECT SUNDAY TO START OFF ON THE NICE SIDE WITH A DECENT AMOUNT OF
SUNSHINE...AS THE AREA IS STILL UNDER THE 900-500MB DRY AIR. THIS
DRY AIR WILL SLIDE EAST-SOUTHEAST THROUGH THE DAY AS THE UPPER
LOW WEST OF LAKE WINNIPEG SHEARS OFF AND STARTS TO SEND PIECES OF
ENERGY ACROSS THE AREA. THE ABUNDANT SUNSHINE TO START THE DAY WILL
ALLOW TEMPERATURES TO QUICKLY RISE INTO THE 70S...WITH A FEW
VALUES IN THE LOWER 80S OVER THE SOUTH CENTRAL.
AS FOR FORCING FEATURES...SURFACE LOW ASSOCIATED WITH THE ELONGATED
TROUGH WILL BE RE-FOCUSING EAST OF LAKE SUPERIOR SUNDAY MORNING AND
THEN PUSHING EAST INTO SOUTHEASTERN ONTARIO ON SUNDAY AFTERNOON...AS
THE MAIN AREA OF SHORTWAVE ENERGY FOLLOWS THAT SAME TRACK. THIS WILL
LEAVE A SURFACE TROUGH OR COLD FRONT BACK ACROSS LAKE
SUPERIOR...WHICH WILL START TO DROP SOUTH OVER UPPER MICHIGAN DURING
THE AFTERNOON HOURS. AS THAT OCCURS...THE INCREASING 850-750MB
MOISTURE SHOULD SPARK SOME HIGH BASED DIURNAL CU. WITH MODEL
CONSENSUS ML CAPE VALUES AROUND 400J/KG...QUESTION COMES TO IF THERE
WILL BE ENOUGH MOISTURE FOR SHOWERS TO DEVELOP. MARGINAL MID-LEVEL
MOISTURE AND DECENT DRY AIR ABOVE 650MB WILL LIKELY
LIMIT THINGS...BUT DID INCLUDE SLIGHTS AND LOW END CHANCES FROM MID
AFTERNOON ON IN CASE THE DEEPER MOISTURE WITH THE TROUGH ARRIVES A
LITTLE QUICKER. IF THERE WASN/T THE INVERTED V LOOK TO THE
SOUNDINGS WITH THE MIXING TO 800-700MB WOULD HAVE CONSIDERED THE
HIGHER INSTABILITY VALUES SEEN IN THE NAM...ML CAPE VALUES AROUND
1000 J/KG...AND BOOSTED POPS UP MORE. EXPECT THE SEVERE THREAT TO BE
LIMITED WITH THESE SHOWERS/THUNDERSTORMS UNLESS THE NAM SOLUTION
VERIFIES. THIS IS DUE TO THE CAPE IS FAIRLY TALL/SKINNY WITH NCAPE
VALUES BELOW 0.1 ALTHOUGH EFFECTIVE SHEAR VALUES ARE IN THE 30-40KT
RANGE. GUSTY WINDS COULD BE A CONCERN WITH THAT INVERTED V
LOOK...DCAPE VALUES OVER 750 J/KG OVER THE SOUTH CENTRAL...AND
EXISTING WINDS GUSTING TO 20-25KTS OVER THE WESTERN CWA.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 432 PM EDT SAT JUN 15 2013
THE FIRST HALF OF THE UPCOMING WEEK WILL FEATURE NW FLOW INTO THE
UPPER GREAT LAKES BTWN A RIDGE DRIFTING FROM THE ROCKIES TO THE
PLAINS AND A BROAD TROF OVER ERN NAMERICA. LATER IN THE WEEK...RIDGE
PROGRESSING INTO THE PLAINS WILL BE SUPPRESSED BY SHORTWAVE ENERGY
EJECTING E FROM A TROF OVER THE PACIFIC NW. WHILE THERE MAY BE SOME
LIMITED OPPORTUNITIES FOR PCPN...NW FLOW WILL NOT SUPPORT
WIDESPREAD/SIGNIFICANT RAINFALL THRU MID WEEK. THE LATE WEEK PERIOD
COULD THEN BECOME ACTIVE WITH BETTER PCPN PROSPECTS AS SHORTWAVES
EJECT E ACROSS THE NRN PLAINS TO THE GREAT LAKES. AS FOR TEMPS...
COOLEST WEATHER WILL OCCUR EARLY IN THE WEEK BEHIND SHORTWAVE
PASSING SUN NIGHT/MON. THEN...DESPITE NW FLOW...TEMPS THRU THE
MIDWEEK PERIOD SHOULD BE CLOSE TO NORMAL OR EVEN A LITTLE ABOVE
NORMAL SINCE ERN TROF WILL NOT HAVE SIGNIFICANT AMPLITUDE INTO THE
ERN CONUS...RESULTING IN COOLER AIR STAYING E AND NE OF THE AREA.
TEMPS LATE WEEK WILL BE ABOVE NORMAL WITH WARMER/MORE HUMID
CONDITIONS.
BEGINNING SUN NIGHT/MON...CURRENTLY WELL-DEFINED MID-LEVEL LOW OVER
SASKATCHEWAN WILL BE WEAKENING CONSIDERABLY/OPENING UP AS IT GETS
SHEARED ESE IN THE FLOW BTWN RIDGE OVER THE ROCKIES AND AMPLIFYING
ERN CANADA TROF. DESPITE THE CURRENT VIGOROUS APPEARANCE/RELATIVELY
LARGE CIRCULATION OF MID-LEVEL LOW...RECENT MODEL TRENDS POINT
TOWARD A WEAKER REMNANT DROPPING THRU THE UPPER MISSISSIPPI
VALLEY/WRN GREAT LAKES WITH BULK OF DEEP LAYER FORCING PER QVECTORS
PASSING BY TO THE SW AND S OF UPPER MI SUN NIGHT/MON. AS SUCH...WILL
ONLY CONTINUE CHC POPS FOR SHRA/TSRA SUN NIGHT INTO MON MORNING.
WITH SHORTWAVE SWINGING BY TO THE S OF UPPER MI MON AND WITH
VIGOROUS LOW/MID LEVEL DRYING SURGING INTO THE AREA FROM THE N IN
THE WAKE OF SHORTWAVE ROTATING THRU NRN ONTARIO...EXPECT ANY SHRA TO
END FROM NW TO SE DURING THE DAY WITH CLEARING FOLLOWING. IT WILL BE
A COOLER DAY...ESPECIALLY NEAR LAKE SUPERIOR...DUE TO BREEZY N WINDS
AND CLOUDS DOMINATING INTO AT LEAST EARLY AFTN. A CHILLY NIGHT IS
THEN ON THE WAY FOR MON NIGHT AS HIGH PRES BUILDS INTO THE UPPER
LAKES. WITH VERY DRY COLUMN (PRECIPITABLE WATER 30-50PCT OF NORMAL)
AND WINDS DIMINISHING TO LIGHT/CALM...WILL CONTINUE OUR RECENT TREND
OF LOWERING MIN TEMPS FOR MON NIGHT. WILL FAVOR LOWER END OF MODEL
GUIDANCE...ESPECIALLY OVER THE W WHERE SFC HIGH PRES CENTER WILL BE
ARRIVING DURING THE NIGHT. WITH IDEAL RADIATIONAL COOLING
CONDITIONS...FROST IS CERTAINLY POSSIBLE IN THE USUAL COLDER
AREAS...AND A MENTION OF FROST WILL BE INCLUDED IN FCST. SOME OF THE
TRADITIONAL COLD SPOTS COULD FALL TO NEAR FREEZING. RECORD LOW FOR
NWS MQT SITE ON THE 18TH IS 38F. NOT OUT OF THE QUESTION THAT RECORD
COULD BE TIED OR POSSIBLY BROKEN.
IN THE WAKE OF THE SHORTWAVE PASSAGE MON...SFC HIGH PRES WILL SETTLE
INTO THE UPPER LAKES TUE...PROVIDING A DRY/PLEASANT MID JUNE DAY
WITH ABUNDANT SUNSHINE UNDER LINGERING VERY DRY COLUMN. LAKE BREEZES
WILL BE THE RULE...KEEPING LAKESIDE LOCATIONS COOLER IN THE AFTN.
UTILIZING MIXING HEIGHTS TO DETERMINE POSSIBLE DWPT CRASH IN THE
AFTN SUGGESTS DWPTS COULD DROP INTO THE 20S IN THE INTERIOR...BUT
DID NOT GO THAT LOW JUST YET. EVEN WITH MID 30S DWPTS...RH WILL
BOTTOM OUT AROUND 25PCT. FORTUNATELY...LIGHT WINDS WILL KEEP FIRE WX
CONCERNS IN CHECK. MEDIUM RANGE GUIDANCE HAS AND CONTINUES TO HINT
THAT A SHORTWAVE MAY DROP SE...PASSING JUST N OF UPPER MI WED/WED
NIGHT. GIVEN THE FAIRLY CONSISTENT SIGNAL FROM ALL MEDIUM RANGE
GUIDANCE...IT APPEARS THERE MAY BE SOME PCPN AT SOME POINT LATER
WED/WED NIGHT. NOTHING MORE THAN SCHC POPS ARE WARRANTED AT THIS
TIME GIVEN THE UNCERTAINTY AND WHAT SHOULD BE LOW COVERAGE IF PCPN
DOES OCCUR. IF WAVE IS FASTER AND ARRIVES DURING PEAK HEATING WED...
PCPN CHC WILL BE GREATER...BUT WOULD STILL NOT EXPECT ANYTHING MORE
THAN SCT COVERAGE.
IT WOULD APPEAR THU SHOULD BE DRY. HOWEVER...THERE IS THE POTENTIAL
FOR SUBTLE BOUNDARY ASSOCIATED WITH SHORTWAVE PASSING BY THE AREA WED
NIGHT TO HANG UP OVER/NEAR UPPER MI...AND THAT COULD BE THE FOCUS FOR
SOME CONVECTION THU AFTN. SCHC/LOW CHC POPS WERE INCLUDED IN FCST.
AS MENTIONED EARLIER...THE LATE WEEK PERIOD COULD BECOME ACTIVE AS
SHORTWAVES TRACK ACROSS THE NRN CONUS TO THE GREAT LAKES...
SUPPRESSING THE RIDGE THAT WAS SHIFTING ACROSS THE PLAINS TO THE
MISSISSIPPI VALLEY. SIGNAL LOOKS STRONG ENOUGH TO WARRANT AT LEAST
MID RANGE CHC POPS FOR SHRA/TSRA FOR MUCH OF FRI AND SAT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 144 PM EDT SAT JUN 15 2013
HAVE REMOVED MENTION OF SHOWERS FOR THE FIRST PART OF THIS
AFTERNOON...AS THE CONSIDERABLE CLOUDINESS AFFECTING ALL THREE
SITES LOWERS CONFIDENCE ON TIMING/LOCATION FOR ANY DIURNAL
DEVELOPMENT. COULD SEE SHOWERS BRUSHING KIWD/KSAW LATE THIS
AFTERNOON AND EARLY EVENING AS A SURFACE TROUGH MOVES THROUGH...BUT
CONFIDENCE IS LOW ON DEVELOPMENT UPSTREAM AND IF THEY WOULD MAKE IT
THAT FAR NORTH.
THE OTHER CONCERN IS WHEN/IF MVFR CLOUDS WILL REACH KCMX/KSAW. BOTH
ARE ON THE NORTHEAST EDGE OF THE MOISTURE IN SOUTHWEST UPPER
MICHIGAN...BUT MODELS ARE PERSISTENT ON IT REACHING BOTH SITES FOR A
FEW HOURS THIS AFTERNOON. CONFIDENCE WASN/T HIGH ENOUGH TO
MENTION AS CEILING...BUT DID INCLUDED SOME SCATTERED MVFR CLOUDS
FOR THIS AFTERNOON. FINALLY...THE MOIST LOW LEVEL AIR MAY PRODUCE
SOME FOG OR LOW STRATUS OVER WESTERN/CENTRAL LAKE SUPERIOR THIS
AFTERNOON/EVENING. THEN...WITH WINDS TURNING WESTERLY BEHIND THE
TROUGH...THIS HAS THE POTENTIAL TO INFLUENCE KCMX. HAVE STARTED A
TREND TOWARDS LOWER VISIBILITIES AND HOPEFULLY THERE WILL BE SHIP
OBS OR CLEARING OVER THE WESTERN LAKE TO GET A BETTER HANDLE ON FOG
FOR THE 00Z TAFS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 432 PM EDT SAT JUN 15 2013
EXPECT WINDS LESS THAN 20KT ACROSS LAKE SUPERIOR THRU THE FCST
PERIOD AS PRES GRADIENT WILL REMAIN GENERALLY WEAK...TYPICAL OF THE
WARM SEASON. THERE MAY BE SOME FOG PATCHES THRU SUN EVENING BEFORE
DRIER AIR BEGINS TO SURGE S INTO THE AREA. IF SOME RAINFALL OCCURS
OVER THE LAKE...FOG WILL BE MORE LIKELY TO FORM AND BECOME MORE
WIDESPREAD/DENSE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...ROLFSON
AVIATION...SRF
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS GAYLORD MI
205 PM EDT SAT JUN 15 2013
.SYNOPSIS...
ISSUED AT 250 AM EDT SAT JUN 15 2013
CLOUDS WILL INCREASE TODAY AS A SERIES OF UPPER LEVEL DISTURBANCES
BRING A CHANCE OF SHOWERS AND THUNDERSTORMS TO NORTHERN MICHIGAN
BEGINNING THIS AFTERNOON AND CONTINUING THROUGH THE WEEKEND AND INTO
EARLY NEXT WORK WEEK.
&&
.UPDATE...
ISSUED AT 158 PM EDT SAT JUN 15 2013
SCATTERED RADAR RETURNS OVER NORTHWEST LOWER...SOME SPITS OF RAIN
REPORTED AT PLN/FKS/TVC. THINGS SEEM TO BE EVOLVING AS
ANTICIPATED... DRY FORECAST OVER EASTERN UPPER STILL LOOKS FINE
AND MAY EVEN SEE SOME PEEKS OF SUN LATER. EXPECT THAT BEST CHANCE
FOR RAINFALL WILL ARRIVE DURING THE EVENING HOURS AS SHORT WAVE
TROUGH MOVING INTO NORTHWEST IOWA SPINS TOWARD LOWER MICHIGAN.
EXPECT ADDITIONAL CONVECTIVE DEVELOPMENT AHEAD OF THIS WAVE OVER
THE NEXT SEVERAL HOURS THAT EVENTUALLY GETS PUSHED INTO AT LEAST
LOWER MICHIGAN BY THIS EVENING.
UPDATE ISSUED AT 1209 PM EDT SAT JUN 15 2013
14Z SURFACE/COMPOSITE ANALYSIS SHOWS 1021MB HIGH CENTERED OVER WEST
VIRGINIA RIDGING NORTHWESTWARD ACROSS LAKE HURON/FAR EASTERN LAKE
SUPERIOR...COLD/OCCLUDED FRONT RUNS FROM NORTHWEST ONTARIO SOUTHWARD
INTO THE UPPER MIDWEST/CENTRAL PLAINS. COUPLE WARM FRONTAL
STRUCTURES EAST OF THE FRONT...ONE EMANATES FROM A FRONTAL WAVE NEAR
MSP AND EXTENDS INTO WISCONSIN...THE OTHER CUTS ACROSS CENTRAL/
SOUTHEAST IOWA. PAIR OF UPPER LOWS TO THE NORTHWEST AND NORTHEAST
OF THE GREAT LAKES...WEAK SHORT WAVE RIDGING IN BETWEEN ACROSS
ILLINOIS/WISCONSIN. WATER VAPOR IMAGERY SHOWS ANOTHER SHORT WAVE
CROSSING THE CENTRAL PLAINS WITH A SMALL MCS IN TOW...MCV MOVING
ACROSS NORTHERN ILLINOIS AND A SMALL SCALE CIRCULATION SHOWING UP ON
RADAR CROSSING NORTHERN LAKE MICHIGAN. THIS LATTER FEATURE IS
PUSHING AN AREA OF LIGHT RAIN SHOWERS AND SPRINKLES TOWARD FAR
NORTHWEST LOWER MICHIGAN AS OF LATE MORNING. FARTHER UPSTREAM
SCATTERED SHOWERS/THUNDERSTORMS OCCURRING ACROSS WESTERN/CENTRAL
UPPER AND NORTHEAST WISCONSIN WITHIN AREA OF LOW LEVEL WARM
ADVECTION AND AHEAD OF AN 850MB TROUGH AXIS. LOW LEVELS ARE DRIER
ACROSS NORTHERN MICHIGAN PER 12Z APX SOUNDING...BUT AXIS OF DEEPER
MOISTURE EXISTS ACROSS WESTERN UPPER/WISCONSIN WHERE PRECIPITABLE
WATER VALUES AROUND 1.25 INCH. PARCELS LIFTED FROM 850MB OFF MPX
SOUNDING YIELDS 2130J/KG CAPE.
WILL CONTINUE WITH THE IDEA OF SPOTTY SHOWERS/SPRINKLES ACROSS
NORTHERN LOWER THIS AFTERNOON WITH PASSAGE OF SMALL VORTICITY CENTER
ACROSS THE TIP OF THE MITT COUNTIES...AND ADDITIONAL SCATTERED
ACTIVITY OCCURRING BEHIND IT. POSSIBLE THAT EASTERN UPPER STAYS
MOSTLY DRY THIS AFTERNOON AND WILL TREND THE FORECAST IN THIS
DIRECTION.
UPDATE ISSUED AT 1009 AM EDT SAT JUN 15 2013
13Z MESOANALYSIS SHOWS A NORTHWEST-SOUTHEAST ORIENTED RIDGE AXIS
RUNNING FROM THE EASTERN SHORE OF LAKE SUPERIOR...ACROSS LAKE HURON
AND DOWN INTO EASTERN OHIO. BROKEN-OVERCAST MID CLOUD DECK HAS
OVERSPREAD NORTHERN MICHIGAN...NOT MUCH ON RADAR OVER THE IMMEDIATE
AREA WITH SOME VERY LIGHT RAIN SHOWERS MOVING ACROSS CENTRAL UPPER
MICHIGAN THOUGH RADAR LOOPS SHOW THIS DRIVEN BY A COMPACT MESOSCALE
VORTICITY CENTER. 12Z APX SOUNDING SHOWS SATURATION IN THE 650-
550MB LAYER BUT IS QUITE DRY BELOW (36C DEW POINT DEPRESSION AT
850MB).
IMMEDIATE NOWCAST CHANGES TO FORECAST WILL BE TO INCREASE CLOUD
COVER... AND ADD IN SOME VERY LIGHT RAIN SHOWERS (OR MOSTLY
SPRINKLES) TO MUCH OF EASTERN UPPER AND NORTH OF A TVC-OSC LINE IN
NORTHWEST LOWER (MOSTLY AFTER 16Z).
UPDATE ISSUED AT 700 AM EDT SAT JUN 15 2013
WIDELY SCATTERED MID LEVEL RETURNS CONTINUE TO DRIFT SOUTH OF OUR
CWA EARLY THIS MORNING PER LATEST KAPX 88D BASE REF LOOP. ALL CIGS
REMAIN ABOVE 10 KFT SO FAR TODAY...BUT DO EXPECTED SOME LOW CLOUD
DEVELOPMENT AS WE HEAD INTO THIS AFTERNOON IN RESPONSE TO
GRADUALLY INCREASING LOW LEVEL MOISTURE AHEAD OF WEAK LOW PRESSURE
TRACKING TOWARD MICHIGAN. PRECIP CHANCES WILL GRADUALLY INCREASE
TOWARD AFTERNOON AS WELL...BUT ANY SHOWER OR THUNDERSTORM ACTIVITY
WILL REMAIN SCATTERED...WITH BETTER CHANCES AND HEAVIER PRECIP
REMAINING SOUTH OF OUR CWA. HAVE MADE SOME ADJUSTMENTS TO CLOUD
COVER BASED ON LATEST IR SATELLITE LOOP. OTHERWISE...CURRENT
FORECAST HIGHLIGHTS INCREASING SMALL CHANCES OF SHOWERS/STORMS
THIS AFTERNOON...WHICH IS STILL ON TARGET.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 250 AM EDT SAT JUN 15 2013
FIRST OF ALL...HATS OFF TO OLD MOTHER NATURE...DELIVERING ONE OF THE
FINER SUMMER DAYS YOU WILL SEE AROUND THESE PARTS YESTERDAY. DRY
AIRMASS RESPONSIBLE FOR SUCH FANTASTIC WEATHER STILL FIRMLY IN
CONTROL AT THIS EARLY HOUR...WITH EXPANSIVE SURFACE HIGH PRESSURE
EXTENDING FROM THE NORTHERN LAKES RIGHT DOWN INTO THE SOUTHEASTERN
STATES. 00Z RAOB PWAT ANALYSIS CONFIRMS SUCH...WITH CP AIRMASS
BRINGING SUB ONE INCH PWAT VALUES ACROSS THIS SAME REGION (RATHER
IMPRESSIVE FOR THIS TIME OF YEAR). UNFORTUNATELY...ONE DOES NOT HAVE
TO VENTURE TOO FAR WEST FOR SOME INCLEMENT WEATHER. BACKSIDE RETURN
FLOW ALREADY AMPING UP ACROSS THE WESTERN LAKES...WITH REAL-TIME OBS
AND HIGH RES RUC ANALYSIS SHOWING ELEVATED MOISTURE PLUME ALREADY
PUNCHING THROUGH WISCONSIN AND WESTERN UPPER MICHIGAN. LEADING
MOISTURE CONVERGENCE AXIS AND SUBTLE WAVE PIVOTING THROUGH BROADER
UPSTREAM RIDGING MANAGED TO KICK OFF SOME EVENING SHOWERS AND STORMS
TO OUR NORTHWEST...ALTHOUGH THESE HAVE LARGELY DIED OUT AS THEY
APPROACH OVERHEAD DEEP LAYER DRY WEDGE. THEME OF THIS SUMMER
CONTINUES...WITH THE MOST PROMINENT AREA OF SHOWERS AND STORMS
REMAINING SAFELY TO OUR SOUTHWEST WHERE NOCTURNALLY CHARGED LOW
LEVEL JET FORCED MASS CONVERGENCE AND DEEP INSTABILITY ARE BETTER
JUXTAPOSED. RADAR AND SATELLITE TRENDS BOTH SUGGEST THIS SHOULD
REMAIN THE CASE RIGHT THROUGH THE EARLY MORNING HOURS...LEAVING
MOSTLY DRY CONDITIONS ACROSS OUR AREA THROUGH AT LEAST THE FIRST
HALF OF THE MORNING. SHORT TERM FORECAST CONCERNS CENTER ON POSSIBLE
ADDITIONAL SHOWER AND STORM DEVELOPMENT TODAY AND TONIGHT.
GOING TO BE AWFULLY HARD TO BEAT YESTERDAY...AND......WE WON`T.
THAT SAID...UPSTREAM TRENDS AND PATTERN RECOGNITION SUPPORTS A
NOT-TO-SHABBY START TO THE WEEKEND. REMAIN LARGELY UNENTHUSED WITH
RAIN CHANCES TODAY...DESPITE STAGE RIGHT DEPARTURE OF CURRENT
SURFACE HIGH. UPSTREAM MID LEVEL RIDGING REPLACES ITS SURFACE
LIKENESS...ALTHOUGH DEAMPLIFYING AS IT DOES SO WITH ENERGY CUTTING
ACROSS SOUTHERN CANADA. UPPER LEVEL FORCING ARRIVES LATE VIA RER
UPPER JET DYNAMICS...MOST OF WHICH HOLDS OFF UNTIL THE OVERNIGHT
HOURS. PER THE USUAL...GUIDANCE JUST SEEMS MUCH TOO AGGRESSIVE
DRIVING LOW LEVEL MOISTURE THIS FAR NORTH...ESPECIALLY GIVEN
ANTECEDENT DRY CONDITIONS AND PROPENSITY FOR MOISTURE STEALING
CONVECTION TO CONTINUE TO FIRE WELL TO OUR SOUTHWEST. MODIFYING
MODEL SUGGESTED SOUNDINGS FOR SUCH SHOWS SIGNIFICANT MID LEVEL CAP
UNTIL VERY LATE...AND LITTLE...IF ANY ML CAPE DEVELOPMENT. CORE OF
MORE IMPRESSIVE MID LEVEL LAPSE RATES REMAINS JUST UPSTREAM ACROSS
WISCONSIN. THETA-E RIDGING DOES ADVANCE EAST WITH TIME....CROSSING
OUR AREA LATE MORNING THROUGH THE AFTERNOON. EVEN THIS...HOWEVER...
WILL BE LOSING DEFINITION WITH TIME. NO DOUBT CLOUDS WILL BE ON THE
INCREASE AS UPSTREAM MID LEVEL MOISTURE PLUME ADVANCES EAST...BUT
GIVEN ALL THE ABOVE...THE PROSPECTS FOR ANY MEANINGFUL RAINS ARE
MUCH LESS THAN IDEAL. SUPPOSE A SPRINKLE/VERY LIGHT SHOWER IS
PLAUSIBLE ALONG THETA-E GRADIENT OR FROM WHAT`S EVER LEFT OF
UPSTREAM ACTIVITY. TEMPTED TO PULL POPS ALTOGETHER...BUT GIVEN SOME
LINGERING UNCERTAINTY...WILL JUST SIMPLY MAINTAIN INHERITED LOW
CHANCE MENTION. DESPITE CLOUDS...THERMAL PROFILES SUPPORT A RATHER
MILD DAY...WITH HIGHS WELL INTO THE 70S ACROSS MOST AREAS. LIGHT
PRESSURE GRADIENT SUPPORTS LATE MORNING AND AFTERNOON LAKE BREEZE
DEVELOPMENT...KEEPING SHORELINE AREAS A FEW DEGREES COOLER.
THINGS TRY TO CONGEAL TO BRING BETTER RAIN CHANCES TONIGHT...WITH
SOMEWHAT DEEPER LOW LEVEL MOISTURE OVERTOPPED BY UPPER JET DYNAMICS.
NOTHING OVERLY IMPRESSIVE THROUGH THE MID LEVELS...WITH PERHAPS A
CONVECTIVELY AUGMENTED VORT LOBE/SUBTLE WAVE RACING EAST ACROSS THE
SOUTHERN THIRD OF THE AREA. PATTERN RECOGNITION CONTINUES TO SUPPORT
SOUTHERN LAKES/NORTHERN OHIO VALLEY MCS DEVELOPMENT ON NOSE OF
STRONGER LOW LEVEL JET. SOME GUIDANCE SEEMS OVERLY AGGRESSIVE
DRIVING CONVECTIVE DEVELOPMENT NORTH...ESPECIALLY THE 00Z GFS AND
12Z ECMWF. DEEP LAYER FLOW SIMPLY DOES NOT BACK ENOUGH TO SUPPORT
THESE NORTH BASED TRENDS. CONVECTIVE EVOLUTION TODAY WILL HAVE
PLENTY TO SAY ON OVERALL MASS FIELDS...BUT LARGE SCALE PATTERN FULLY
SUPPORTS A MORE SOUTH BASED PASSAGE TO ANY MCS TONIGHT...WITH JUST
SOME LIGHTER ACTIVITY THIS FAR NORTH. WILL TREND POPS AS SUCH...BUT
STILL LEAVE PLENTY OF OPPORTUNITY FOR FUTURE ADJUSTMENTS BASED ON
THIS AFTERNOONS UPSTREAM TRENDS. A MILD NIGHT...WITH LOWS IN THE 50S
AND LOWER 60S.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 250 AM EDT SAT JUN 15 2013
SUNDAY AND MONDAY...A WEAK AREA OF LOW PRESSURE WILL SLIDE EAST THRU
MICHIGAN EARLY SUNDAY MORNING. THIS LOW WILL GRADUALLY MERGE WITH
ANOTHER NRN STREAM LOW DROPPING SE INTO MICHIGAN SUNDAY AFTERNOON
AND EVENING. A COLD FRONT ASSOCIATED WITH THE SECOND LOW PRESSURE
SYSTEM WILL DROP INTO NRN MICHIGAN SUNDAY NIGHT...AND WILL THEN
SWEEP THRU LWR MICHIGAN ON MONDAY. LATEST NAM APPEARS TO BE TOO FAST
WITH THE PASSAGE OF THIS FRONT CONSIDERING THE FRONT BECOMES
ORIENTED WEST TO EAST ALONG THE UPPER LEVEL FLOW ONCE IT REACHES
UPPER MICHIGAN. ECMWF PROVIDES A SLOWER AND THUS MORE REASONABLE
SOLUTION...AND WILL LEAN IN THIS DIRECTION. CHANCE OF SHOWERS/STORMS
WILL LINGER INTO SUNDAY MORNING FOR MUCH OF OUR CWA AS THE INITIAL
SURFACE LOW EXITS LWR MICHIGAN. DIURNAL INSTABILITY COMBINED WITH
WEAK LAKE BREEZE BOUNDARIES AND LINGERING LOW LEVEL MOISTURE TO
PROVIDE SMALL CHANCES OF SHOWERS AND STORMS FOR ERN UPR AND NE LWR
MICHIGAN SUNDAY AFTERNOON. SECONDARY SURFACE LOW AND ASSOCIATED COLD
FRONT WILL DROP INTO ERN UPR AND FAR NRN LWR MICHIGAN SUNDAY
AFTERNOON/EVENING...PROVIDING ADDITIONAL FOCUS FOR CONVECTIVE
DEVELOPMENT TO PERSIST THRU THE NIGHT ACROSS LOCATIONS ALONG AND
NORTH OF M-32. BY MONDAY...THE SLOW-MOVING COLD FRONT WILL DROP THRU
THE REST OF OUR CWA...RESULTING IN CONTINUED CONVECTIVE DEVELOPMENT
THRU THE DAY. CHANCES OF SHOWERS AND STORMS WILL COME TO AN END THRU
MONDAY NIGHT AS THE COLD FRONT EXITS LWR MICHIGAN.
TUESDAY THRU FRIDAY...STRONG CANADIAN HIGH PRESSURE...SUBSIDENCE AND
DRY AIR WILL BUILD INTO THE GREAT LAKES TUESDAY INTO WEDNESDAY
BEHIND THE DEPARTING COLD FRONT. DRY WEATHER IS EXPECTED THRU THIS
TIME PERIOD...WITH TEMPS SEVERAL DEGREES BELOW NORMAL THANKS TO CAA.
WEAK AREA OF LOW PRESSURE WILL SLOWLY TRACK THRU ONTARIO AND INTO
QUEBEC WEDNESDAY NIGHT THRU FRIDAY...DRAGGING THE SRN END OF A WEAK
FRONT THRU NRN MICHIGAN. BOTH MOISTURE AND LIFT WILL BE LIMITED WITH
THIS WEAK FEATURE...BUT WILL INTRODUCE SMALL PRECIP CHANCES INTO THE
FORECAST FOR THIS TIMEFRAME AS THIS FRONT PASSES THRU THE REGION.
TEMPS WILL REBOUND TO NEAR NORMAL IN WEAK WAA AHEAD OF THIS FRONT.
INITIAL LOOK FOR NEXT WEEKEND SUGGESTS MAINLY DRY WEATHER WITH NEAR
NORMAL TEMPS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 158 PM EDT SAT JUN 15 2013
VFR CONDITIONS THROUGH THE AFTERNOON...SOME MVFR VISIBLITIES WITH
RAIN SHOWERS TONIGHT AND A PERIOD OF MVFR/IFR CEILINGS OVERNIGHT
THAT WILL MIX OUT SUNDAY MORNING.
&&
.MARINE...
ISSUED AT 250 AM EDT SAT JUN 15 2013
LIGHT WINDS CONTINUE...WITH LOCAL LAKE BREEZE DEVELOPMENT
THIS AFTERNOON...ESPECIALLY OFF LAKE HURON. WEAK SURFACE TROUGH
PASSES THROUGH THE REGION LATE TONIGHT INTO EARLY SUNDAY...VEERING
SOUTHWEST FLOW TO WESTERLY. MARINE FOG EXPECTED TO DEVELOP LATER
TONIGHT INTO SUNDAY AS LOW LEVEL MOISTURE ADVECTION STRENGTHENS.
SHOWERS AND STORMS POSSIBLE TONIGHT...ALTHOUGH STRONGEST ACTIVITY
EXPECTED TO REMAIN ACROSS THE SOUTHERN LAKES. EARLY INDICATIONS ARE
FOR MAINLY LIGHT WINDS TO CONTINUE RIGHT THROUGH MUCH OF NEXT WORK
WEEK.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...JPB
SYNOPSIS...MLR
SHORT TERM...MSB
LONG TERM...MLR
MARINE...MSB
AREA FORECAST DISCUSSION
NWS GAYLORD MI
1209 PM EDT SAT JUN 15 2013
.SYNOPSIS...
ISSUED AT 250 AM EDT SAT JUN 15 2013
CLOUDS WILL INCREASE TODAY AS A SERIES OF UPPER LEVEL DISTURBANCES
BRING A CHANCE OF SHOWERS AND THUNDERSTORMS TO NORTHERN MICHIGAN
BEGINNING THIS AFTERNOON AND CONTINUING THROUGH THE WEEKEND AND INTO
EARLY NEXT WORK WEEK.
&&
.UPDATE...
ISSUED AT 1209 PM EDT SAT JUN 15 2013
14Z SURFACE/COMPOSITE ANALYSIS SHOWS 1021MB HIGH CENTERED OVER WEST
VIRGINIA RIDGING NORTHWESTWARD ACROSS LAKE HURON/FAR EASTERN LAKE
SUPERIOR...COLD/OCCLUDED FRONT RUNS FROM NORTHWEST ONTARIO SOUTHWARD
INTO THE UPPER MIDWEST/CENTRAL PLAINS. COUPLE WARM FRONTAL
STRUCTURES EAST OF THE FRONT...ONE EMANATES FROM A FRONTAL WAVE NEAR
MSP AND EXTENDS INTO WISCONSIN...THE OTHER CUTS ACROSS CENTRAL/
SOUTHEAST IOWA. PAIR OF UPPER LOWS TO THE NORTHWEST AND NORTHEAST
OF THE GREAT LAKES...WEAK SHORT WAVE RIDGING IN BETWEEN ACROSS
ILLINOIS/WISCONSIN. WATER VAPOR IMAGERY SHOWS ANOTHER SHORT WAVE
CROSSING THE CENTRAL PLAINS WITH A SMALL MCS IN TOW...MCV MOVING
ACROSS NORTHERN ILLINOIS AND A SMALL SCALE CIRCULATION SHOWING UP ON
RADAR CROSSING NORTHERN LAKE MICHIGAN. THIS LATTER FEATURE IS
PUSHING AN AREA OF LIGHT RAIN SHOWERS AND SPRINKLES TOWARD FAR
NORTHWEST LOWER MICHIGAN AS OF LATE MORNING. FARTHER UPSTREAM
SCATTERED SHOWERS/THUNDERSTORMS OCCURRING ACROSS WESTERN/CENTRAL
UPPER AND NORTHEAST WISCONSIN WITHIN AREA OF LOW LEVEL WARM
ADVECTION AND AHEAD OF AN 850MB TROUGH AXIS. LOW LEVELS ARE DRIER
ACROSS NORTHERN MICHIGAN PER 12Z APX SOUNDING...BUT AXIS OF DEEPER
MOISTURE EXISTS ACROSS WESTERN UPPER/WISCONSIN WHERE PRECIPITABLE
WATER VALUES AROUND 1.25 INCH. PARCELS LIFTED FROM 850MB OFF MPX
SOUNDING YIELDS 2130J/KG CAPE.
WILL CONTINUE WITH THE IDEA OF SPOTTY SHOWERS/SPRINKLES ACROSS
NORTHERN LOWER THIS AFTERNOON WITH PASSAGE OF SMALL VORTICITY CENTER
ACROSS THE TIP OF THE MITT COUNTIES...AND ADDITIONAL SCATTERED
ACTIVITY OCCURRING BEHIND IT. POSSIBLE THAT EASTERN UPPER STAYS
MOSTLY DRY THIS AFTERNOON AND WILL TREND THE FORECAST IN THIS
DIRECTION.
UPDATE ISSUED AT 1009 AM EDT SAT JUN 15 2013
13Z MESOANALYSIS SHOWS A NORTHWEST-SOUTHEAST ORIENTED RIDGE AXIS
RUNNING FROM THE EASTERN SHORE OF LAKE SUPERIOR...ACROSS LAKE HURON
AND DOWN INTO EASTERN OHIO. BROKEN-OVERCAST MID CLOUD DECK HAS
OVERSPREAD NORTHERN MICHIGAN...NOT MUCH ON RADAR OVER THE IMMEDIATE
AREA WITH SOME VERY LIGHT RAIN SHOWERS MOVING ACROSS CENTRAL UPPER
MICHIGAN THOUGH RADAR LOOPS SHOW THIS DRIVEN BY A COMPACT MESOSCALE
VORTICITY CENTER. 12Z APX SOUNDING SHOWS SATURATION IN THE 650-
550MB LAYER BUT IS QUITE DRY BELOW (36C DEW POINT DEPRESSION AT
850MB).
IMMEDIATE NOWCAST CHANGES TO FORECAST WILL BE TO INCREASE CLOUD
COVER... AND ADD IN SOME VERY LIGHT RAIN SHOWERS (OR MOSTLY
SPRINKLES) TO MUCH OF EASTERN UPPER AND NORTH OF A TVC-OSC LINE IN
NORTHWEST LOWER (MOSTLY AFTER 16Z).
UPDATE ISSUED AT 700 AM EDT SAT JUN 15 2013
WIDELY SCATTERED MID LEVEL RETURNS CONTINUE TO DRIFT SOUTH OF OUR
CWA EARLY THIS MORNING PER LATEST KAPX 88D BASE REF LOOP. ALL CIGS
REMAIN ABOVE 10 KFT SO FAR TODAY...BUT DO EXPECTED SOME LOW CLOUD
DEVELOPMENT AS WE HEAD INTO THIS AFTERNOON IN RESPONSE TO
GRADUALLY INCREASING LOW LEVEL MOISTURE AHEAD OF WEAK LOW PRESSURE
TRACKING TOWARD MICHIGAN. PRECIP CHANCES WILL GRADUALLY INCREASE
TOWARD AFTERNOON AS WELL...BUT ANY SHOWER OR THUNDERSTORM ACTIVITY
WILL REMAIN SCATTERED...WITH BETTER CHANCES AND HEAVIER PRECIP
REMAINING SOUTH OF OUR CWA. HAVE MADE SOME ADJUSTMENTS TO CLOUD
COVER BASED ON LATEST IR SATELLITE LOOP. OTHERWISE...CURRENT
FORECAST HIGHLIGHTS INCREASING SMALL CHANCES OF SHOWERS/STORMS
THIS AFTERNOON...WHICH IS STILL ON TARGET.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 250 AM EDT SAT JUN 15 2013
FIRST OF ALL...HATS OFF TO OLD MOTHER NATURE...DELIVERING ONE OF THE
FINER SUMMER DAYS YOU WILL SEE AROUND THESE PARTS YESTERDAY. DRY
AIRMASS RESPONSIBLE FOR SUCH FANTASTIC WEATHER STILL FIRMLY IN
CONTROL AT THIS EARLY HOUR...WITH EXPANSIVE SURFACE HIGH PRESSURE
EXTENDING FROM THE NORTHERN LAKES RIGHT DOWN INTO THE SOUTHEASTERN
STATES. 00Z RAOB PWAT ANALYSIS CONFIRMS SUCH...WITH CP AIRMASS
BRINGING SUB ONE INCH PWAT VALUES ACROSS THIS SAME REGION (RATHER
IMPRESSIVE FOR THIS TIME OF YEAR). UNFORTUNATELY...ONE DOES NOT HAVE
TO VENTURE TOO FAR WEST FOR SOME INCLEMENT WEATHER. BACKSIDE RETURN
FLOW ALREADY AMPING UP ACROSS THE WESTERN LAKES...WITH REAL-TIME OBS
AND HIGH RES RUC ANALYSIS SHOWING ELEVATED MOISTURE PLUME ALREADY
PUNCHING THROUGH WISCONSIN AND WESTERN UPPER MICHIGAN. LEADING
MOISTURE CONVERGENCE AXIS AND SUBTLE WAVE PIVOTING THROUGH BROADER
UPSTREAM RIDGING MANAGED TO KICK OFF SOME EVENING SHOWERS AND STORMS
TO OUR NORTHWEST...ALTHOUGH THESE HAVE LARGELY DIED OUT AS THEY
APPROACH OVERHEAD DEEP LAYER DRY WEDGE. THEME OF THIS SUMMER
CONTINUES...WITH THE MOST PROMINENT AREA OF SHOWERS AND STORMS
REMAINING SAFELY TO OUR SOUTHWEST WHERE NOCTURNALLY CHARGED LOW
LEVEL JET FORCED MASS CONVERGENCE AND DEEP INSTABILITY ARE BETTER
JUXTAPOSED. RADAR AND SATELLITE TRENDS BOTH SUGGEST THIS SHOULD
REMAIN THE CASE RIGHT THROUGH THE EARLY MORNING HOURS...LEAVING
MOSTLY DRY CONDITIONS ACROSS OUR AREA THROUGH AT LEAST THE FIRST
HALF OF THE MORNING. SHORT TERM FORECAST CONCERNS CENTER ON POSSIBLE
ADDITIONAL SHOWER AND STORM DEVELOPMENT TODAY AND TONIGHT.
GOING TO BE AWFULLY HARD TO BEAT YESTERDAY...AND......WE WON`T.
THAT SAID...UPSTREAM TRENDS AND PATTERN RECOGNITION SUPPORTS A
NOT-TO-SHABBY START TO THE WEEKEND. REMAIN LARGELY UNENTHUSED WITH
RAIN CHANCES TODAY...DESPITE STAGE RIGHT DEPARTURE OF CURRENT
SURFACE HIGH. UPSTREAM MID LEVEL RIDGING REPLACES ITS SURFACE
LIKENESS...ALTHOUGH DEAMPLIFYING AS IT DOES SO WITH ENERGY CUTTING
ACROSS SOUTHERN CANADA. UPPER LEVEL FORCING ARRIVES LATE VIA RER
UPPER JET DYNAMICS...MOST OF WHICH HOLDS OFF UNTIL THE OVERNIGHT
HOURS. PER THE USUAL...GUIDANCE JUST SEEMS MUCH TOO AGGRESSIVE
DRIVING LOW LEVEL MOISTURE THIS FAR NORTH...ESPECIALLY GIVEN
ANTECEDENT DRY CONDITIONS AND PROPENSITY FOR MOISTURE STEALING
CONVECTION TO CONTINUE TO FIRE WELL TO OUR SOUTHWEST. MODIFYING
MODEL SUGGESTED SOUNDINGS FOR SUCH SHOWS SIGNIFICANT MID LEVEL CAP
UNTIL VERY LATE...AND LITTLE...IF ANY ML CAPE DEVELOPMENT. CORE OF
MORE IMPRESSIVE MID LEVEL LAPSE RATES REMAINS JUST UPSTREAM ACROSS
WISCONSIN. THETA-E RIDGING DOES ADVANCE EAST WITH TIME....CROSSING
OUR AREA LATE MORNING THROUGH THE AFTERNOON. EVEN THIS...HOWEVER...
WILL BE LOSING DEFINITION WITH TIME. NO DOUBT CLOUDS WILL BE ON THE
INCREASE AS UPSTREAM MID LEVEL MOISTURE PLUME ADVANCES EAST...BUT
GIVEN ALL THE ABOVE...THE PROSPECTS FOR ANY MEANINGFUL RAINS ARE
MUCH LESS THAN IDEAL. SUPPOSE A SPRINKLE/VERY LIGHT SHOWER IS
PLAUSIBLE ALONG THETA-E GRADIENT OR FROM WHAT`S EVER LEFT OF
UPSTREAM ACTIVITY. TEMPTED TO PULL POPS ALTOGETHER...BUT GIVEN SOME
LINGERING UNCERTAINTY...WILL JUST SIMPLY MAINTAIN INHERITED LOW
CHANCE MENTION. DESPITE CLOUDS...THERMAL PROFILES SUPPORT A RATHER
MILD DAY...WITH HIGHS WELL INTO THE 70S ACROSS MOST AREAS. LIGHT
PRESSURE GRADIENT SUPPORTS LATE MORNING AND AFTERNOON LAKE BREEZE
DEVELOPMENT...KEEPING SHORELINE AREAS A FEW DEGREES COOLER.
THINGS TRY TO CONGEAL TO BRING BETTER RAIN CHANCES TONIGHT...WITH
SOMEWHAT DEEPER LOW LEVEL MOISTURE OVERTOPPED BY UPPER JET DYNAMICS.
NOTHING OVERLY IMPRESSIVE THROUGH THE MID LEVELS...WITH PERHAPS A
CONVECTIVELY AUGMENTED VORT LOBE/SUBTLE WAVE RACING EAST ACROSS THE
SOUTHERN THIRD OF THE AREA. PATTERN RECOGNITION CONTINUES TO SUPPORT
SOUTHERN LAKES/NORTHERN OHIO VALLEY MCS DEVELOPMENT ON NOSE OF
STRONGER LOW LEVEL JET. SOME GUIDANCE SEEMS OVERLY AGGRESSIVE
DRIVING CONVECTIVE DEVELOPMENT NORTH...ESPECIALLY THE 00Z GFS AND
12Z ECMWF. DEEP LAYER FLOW SIMPLY DOES NOT BACK ENOUGH TO SUPPORT
THESE NORTH BASED TRENDS. CONVECTIVE EVOLUTION TODAY WILL HAVE
PLENTY TO SAY ON OVERALL MASS FIELDS...BUT LARGE SCALE PATTERN FULLY
SUPPORTS A MORE SOUTH BASED PASSAGE TO ANY MCS TONIGHT...WITH JUST
SOME LIGHTER ACTIVITY THIS FAR NORTH. WILL TREND POPS AS SUCH...BUT
STILL LEAVE PLENTY OF OPPORTUNITY FOR FUTURE ADJUSTMENTS BASED ON
THIS AFTERNOONS UPSTREAM TRENDS. A MILD NIGHT...WITH LOWS IN THE 50S
AND LOWER 60S.
&&
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 250 AM EDT SAT JUN 15 2013
SUNDAY AND MONDAY...A WEAK AREA OF LOW PRESSURE WILL SLIDE EAST THRU
MICHIGAN EARLY SUNDAY MORNING. THIS LOW WILL GRADUALLY MERGE WITH
ANOTHER NRN STREAM LOW DROPPING SE INTO MICHIGAN SUNDAY AFTERNOON
AND EVENING. A COLD FRONT ASSOCIATED WITH THE SECOND LOW PRESSURE
SYSTEM WILL DROP INTO NRN MICHIGAN SUNDAY NIGHT...AND WILL THEN
SWEEP THRU LWR MICHIGAN ON MONDAY. LATEST NAM APPEARS TO BE TOO FAST
WITH THE PASSAGE OF THIS FRONT CONSIDERING THE FRONT BECOMES
ORIENTED WEST TO EAST ALONG THE UPPER LEVEL FLOW ONCE IT REACHES
UPPER MICHIGAN. ECMWF PROVIDES A SLOWER AND THUS MORE REASONABLE
SOLUTION...AND WILL LEAN IN THIS DIRECTION. CHANCE OF SHOWERS/STORMS
WILL LINGER INTO SUNDAY MORNING FOR MUCH OF OUR CWA AS THE INITIAL
SURFACE LOW EXITS LWR MICHIGAN. DIURNAL INSTABILITY COMBINED WITH
WEAK LAKE BREEZE BOUNDARIES AND LINGERING LOW LEVEL MOISTURE TO
PROVIDE SMALL CHANCES OF SHOWERS AND STORMS FOR ERN UPR AND NE LWR
MICHIGAN SUNDAY AFTERNOON. SECONDARY SURFACE LOW AND ASSOCIATED COLD
FRONT WILL DROP INTO ERN UPR AND FAR NRN LWR MICHIGAN SUNDAY
AFTERNOON/EVENING...PROVIDING ADDITIONAL FOCUS FOR CONVECTIVE
DEVELOPMENT TO PERSIST THRU THE NIGHT ACROSS LOCATIONS ALONG AND
NORTH OF M-32. BY MONDAY...THE SLOW-MOVING COLD FRONT WILL DROP THRU
THE REST OF OUR CWA...RESULTING IN CONTINUED CONVECTIVE DEVELOPMENT
THRU THE DAY. CHANCES OF SHOWERS AND STORMS WILL COME TO AN END THRU
MONDAY NIGHT AS THE COLD FRONT EXITS LWR MICHIGAN.
TUESDAY THRU FRIDAY...STRONG CANADIAN HIGH PRESSURE...SUBSIDENCE AND
DRY AIR WILL BUILD INTO THE GREAT LAKES TUESDAY INTO WEDNESDAY
BEHIND THE DEPARTING COLD FRONT. DRY WEATHER IS EXPECTED THRU THIS
TIME PERIOD...WITH TEMPS SEVERAL DEGREES BELOW NORMAL THANKS TO CAA.
WEAK AREA OF LOW PRESSURE WILL SLOWLY TRACK THRU ONTARIO AND INTO
QUEBEC WEDNESDAY NIGHT THRU FRIDAY...DRAGGING THE SRN END OF A WEAK
FRONT THRU NRN MICHIGAN. BOTH MOISTURE AND LIFT WILL BE LIMITED WITH
THIS WEAK FEATURE...BUT WILL INTRODUCE SMALL PRECIP CHANCES INTO THE
FORECAST FOR THIS TIMEFRAME AS THIS FRONT PASSES THRU THE REGION.
TEMPS WILL REBOUND TO NEAR NORMAL IN WEAK WAA AHEAD OF THIS FRONT.
INITIAL LOOK FOR NEXT WEEKEND SUGGESTS MAINLY DRY WEATHER WITH NEAR
NORMAL TEMPS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 700 AM EDT SAT JUN 15 2013
OVERALL CONDITIONS WILL REMAIN VFR THRU THE 24 HR TAF FORECAST
PERIOD. A THICK DECK OF MID CLOUDS WILL REMAIN OVERHEAD...AS
SCT/BKN LOW CLOUDS AT AROUND 5-6 KFT DEVELOPS TODAY AND TONIGHT.
CHANCES OF SHOWERS AND POSSIBLY A THUNDERSTORM WILL GRADUALLY
INCREASE AS WE HEAD INTO THIS AFTERNOON AND TONIGHT ALONG AND
AHEAD OF WEAK LOW PRESSURE TRACKING EAST THRU MICHIGAN. LIGHT
WINDS THIS MORNING WILL ONLY INCREASE TO LESS THAN 10 KTS FROM THE
SW BY THIS AFTERNOON...WITH SOME LAKE BREEZE DEVELOPMENT EXPECTED
ALONG THE LAKESHORES.
&&
.MARINE...
ISSUED AT 250 AM EDT SAT JUN 15 2013
LIGHT WINDS CONTINUE...WITH LOCAL LAKE BREEZE DEVELOPMENT
THIS AFTERNOON...ESPECIALLY OFF LAKE HURON. WEAK SURFACE TROUGH
PASSES THROUGH THE REGION LATE TONIGHT INTO EARLY SUNDAY...VEERING
SOUTHWEST FLOW TO WESTERLY. MARINE FOG EXPECTED TO DEVELOP LATER
TONIGHT INTO SUNDAY AS LOW LEVEL MOISTURE ADVECTION STRENGTHENS.
SHOWERS AND STORMS POSSIBLE TONIGHT...ALTHOUGH STRONGEST ACTIVITY
EXPECTED TO REMAIN ACROSS THE SOUTHERN LAKES. EARLY INDICATIONS ARE
FOR MAINLY LIGHT WINDS TO CONTINUE RIGHT THROUGH MUCH OF NEXT WORK
WEEK.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...JPB
SYNOPSIS...MLR
SHORT TERM...MSB
LONG TERM...MLR
AVIATION...MLR
MARINE...MSB
AREA FORECAST DISCUSSION
NWS GAYLORD MI
1009 AM EDT SAT JUN 15 2013
.SYNOPSIS...
ISSUED AT 250 AM EDT SAT JUN 15 2013
CLOUDS WILL INCREASE TODAY AS A SERIES OF UPPER LEVEL DISTURBANCES
BRING A CHANCE OF SHOWERS AND THUNDERSTORMS TO NORTHERN MICHIGAN
BEGINNING THIS AFTERNOON AND CONTINUING THROUGH THE WEEKEND AND INTO
EARLY NEXT WORK WEEK.
&&
.UPDATE...
ISSUED AT 1009 AM EDT SAT JUN 15 2013
13Z MESOANALYSIS SHOWS A NORTHWEST-SOUTHEAST ORIENTED RIDGE AXIS
RUNNING FROM THE EASTERN SHORE OF LAKE SUPERIOR...ACROSS LAKE HURON
AND DOWN INTO EASTERN OHIO. BROKEN-OVERCAST MID CLOUD DECK HAS
OVERSPREAD NORTHERN MICHIGAN...NOT MUCH ON RADAR OVER THE IMMEDIATE
AREA WITH SOME VERY LIGHT RAIN SHOWERS MOVING ACROSS CENTRAL UPPER
MICHIGAN THOUGH RADAR LOOPS SHOW THIS DRIVEN BY A COMPACT MESOSCALE
VORTICITY CENTER. 12Z APX SOUNDING SHOWS SATURATION IN THE 650-
550MB LAYER BUT IS QUITE DRY BELOW (36C DEW POINT DEPRESSION AT
850MB).
IMMEDIATE NOWCAST CHANGES TO FORECAST WILL BE TO INCREASE CLOUD
COVER... AND ADD IN SOME VERY LIGHT RAIN SHOWERS (OR MOSTLY
SPRINKLES) TO MUCH OF EASTERN UPPER AND NORTH OF A TVC-OSC LINE IN
NORTHWEST LOWER (MOSTLY AFTER 16Z).
UPDATE ISSUED AT 700 AM EDT SAT JUN 15 2013
WIDELY SCATTERED MID LEVEL RETURNS CONTINUE TO DRIFT SOUTH OF OUR
CWA EARLY THIS MORNING PER LATEST KAPX 88D BASE REF LOOP. ALL CIGS
REMAIN ABOVE 10 KFT SO FAR TODAY...BUT DO EXPECTED SOME LOW CLOUD
DEVELOPMENT AS WE HEAD INTO THIS AFTERNOON IN RESPONSE TO
GRADUALLY INCREASING LOW LEVEL MOISTURE AHEAD OF WEAK LOW PRESSURE
TRACKING TOWARD MICHIGAN. PRECIP CHANCES WILL GRADUALLY INCREASE
TOWARD AFTERNOON AS WELL...BUT ANY SHOWER OR THUNDERSTORM ACTIVITY
WILL REMAIN SCATTERED...WITH BETTER CHANCES AND HEAVIER PRECIP
REMAINING SOUTH OF OUR CWA. HAVE MADE SOME ADJUSTMENTS TO CLOUD
COVER BASED ON LATEST IR SATELLITE LOOP. OTHERWISE...CURRENT
FORECAST HIGHLIGHTS INCREASING SMALL CHANCES OF SHOWERS/STORMS
THIS AFTERNOON...WHICH IS STILL ON TARGET.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 250 AM EDT SAT JUN 15 2013
FIRST OF ALL...HATS OFF TO OLD MOTHER NATURE...DELIVERING ONE OF THE
FINER SUMMER DAYS YOU WILL SEE AROUND THESE PARTS YESTERDAY. DRY
AIRMASS RESPONSIBLE FOR SUCH FANTASTIC WEATHER STILL FIRMLY IN
CONTROL AT THIS EARLY HOUR...WITH EXPANSIVE SURFACE HIGH PRESSURE
EXTENDING FROM THE NORTHERN LAKES RIGHT DOWN INTO THE SOUTHEASTERN
STATES. 00Z RAOB PWAT ANALYSIS CONFIRMS SUCH...WITH CP AIRMASS
BRINGING SUB ONE INCH PWAT VALUES ACROSS THIS SAME REGION (RATHER
IMPRESSIVE FOR THIS TIME OF YEAR). UNFORTUNATELY...ONE DOES NOT HAVE
TO VENTURE TOO FAR WEST FOR SOME INCLEMENT WEATHER. BACKSIDE RETURN
FLOW ALREADY AMPING UP ACROSS THE WESTERN LAKES...WITH REAL-TIME OBS
AND HIGH RES RUC ANALYSIS SHOWING ELEVATED MOISTURE PLUME ALREADY
PUNCHING THROUGH WISCONSIN AND WESTERN UPPER MICHIGAN. LEADING
MOISTURE CONVERGENCE AXIS AND SUBTLE WAVE PIVOTING THROUGH BROADER
UPSTREAM RIDGING MANAGED TO KICK OFF SOME EVENING SHOWERS AND STORMS
TO OUR NORTHWEST...ALTHOUGH THESE HAVE LARGELY DIED OUT AS THEY
APPROACH OVERHEAD DEEP LAYER DRY WEDGE. THEME OF THIS SUMMER
CONTINUES...WITH THE MOST PROMINENT AREA OF SHOWERS AND STORMS
REMAINING SAFELY TO OUR SOUTHWEST WHERE NOCTURNALLY CHARGED LOW
LEVEL JET FORCED MASS CONVERGENCE AND DEEP INSTABILITY ARE BETTER
JUXTAPOSED. RADAR AND SATELLITE TRENDS BOTH SUGGEST THIS SHOULD
REMAIN THE CASE RIGHT THROUGH THE EARLY MORNING HOURS...LEAVING
MOSTLY DRY CONDITIONS ACROSS OUR AREA THROUGH AT LEAST THE FIRST
HALF OF THE MORNING. SHORT TERM FORECAST CONCERNS CENTER ON POSSIBLE
ADDITIONAL SHOWER AND STORM DEVELOPMENT TODAY AND TONIGHT.
GOING TO BE AWFULLY HARD TO BEAT YESTERDAY...AND......WE WON`T.
THAT SAID...UPSTREAM TRENDS AND PATTERN RECOGNITION SUPPORTS A
NOT-TO-SHABBY START TO THE WEEKEND. REMAIN LARGELY UNENTHUSED WITH
RAIN CHANCES TODAY...DESPITE STAGE RIGHT DEPARTURE OF CURRENT
SURFACE HIGH. UPSTREAM MID LEVEL RIDGING REPLACES ITS SURFACE
LIKENESS...ALTHOUGH DEAMPLIFYING AS IT DOES SO WITH ENERGY CUTTING
ACROSS SOUTHERN CANADA. UPPER LEVEL FORCING ARRIVES LATE VIA RER
UPPER JET DYNAMICS...MOST OF WHICH HOLDS OFF UNTIL THE OVERNIGHT
HOURS. PER THE USUAL...GUIDANCE JUST SEEMS MUCH TOO AGGRESSIVE
DRIVING LOW LEVEL MOISTURE THIS FAR NORTH...ESPECIALLY GIVEN
ANTECEDENT DRY CONDITIONS AND PROPENSITY FOR MOISTURE STEALING
CONVECTION TO CONTINUE TO FIRE WELL TO OUR SOUTHWEST. MODIFYING
MODEL SUGGESTED SOUNDINGS FOR SUCH SHOWS SIGNIFICANT MID LEVEL CAP
UNTIL VERY LATE...AND LITTLE...IF ANY ML CAPE DEVELOPMENT. CORE OF
MORE IMPRESSIVE MID LEVEL LAPSE RATES REMAINS JUST UPSTREAM ACROSS
WISCONSIN. THETA-E RIDGING DOES ADVANCE EAST WITH TIME....CROSSING
OUR AREA LATE MORNING THROUGH THE AFTERNOON. EVEN THIS...HOWEVER...
WILL BE LOSING DEFINITION WITH TIME. NO DOUBT CLOUDS WILL BE ON THE
INCREASE AS UPSTREAM MID LEVEL MOISTURE PLUME ADVANCES EAST...BUT
GIVEN ALL THE ABOVE...THE PROSPECTS FOR ANY MEANINGFUL RAINS ARE
MUCH LESS THAN IDEAL. SUPPOSE A SPRINKLE/VERY LIGHT SHOWER IS
PLAUSIBLE ALONG THETA-E GRADIENT OR FROM WHAT`S EVER LEFT OF
UPSTREAM ACTIVITY. TEMPTED TO PULL POPS ALTOGETHER...BUT GIVEN SOME
LINGERING UNCERTAINTY...WILL JUST SIMPLY MAINTAIN INHERITED LOW
CHANCE MENTION. DESPITE CLOUDS...THERMAL PROFILES SUPPORT A RATHER
MILD DAY...WITH HIGHS WELL INTO THE 70S ACROSS MOST AREAS. LIGHT
PRESSURE GRADIENT SUPPORTS LATE MORNING AND AFTERNOON LAKE BREEZE
DEVELOPMENT...KEEPING SHORELINE AREAS A FEW DEGREES COOLER.
THINGS TRY TO CONGEAL TO BRING BETTER RAIN CHANCES TONIGHT...WITH
SOMEWHAT DEEPER LOW LEVEL MOISTURE OVERTOPPED BY UPPER JET DYNAMICS.
NOTHING OVERLY IMPRESSIVE THROUGH THE MID LEVELS...WITH PERHAPS A
CONVECTIVELY AUGMENTED VORT LOBE/SUBTLE WAVE RACING EAST ACROSS THE
SOUTHERN THIRD OF THE AREA. PATTERN RECOGNITION CONTINUES TO SUPPORT
SOUTHERN LAKES/NORTHERN OHIO VALLEY MCS DEVELOPMENT ON NOSE OF
STRONGER LOW LEVEL JET. SOME GUIDANCE SEEMS OVERLY AGGRESSIVE
DRIVING CONVECTIVE DEVELOPMENT NORTH...ESPECIALLY THE 00Z GFS AND
12Z ECMWF. DEEP LAYER FLOW SIMPLY DOES NOT BACK ENOUGH TO SUPPORT
THESE NORTH BASED TRENDS. CONVECTIVE EVOLUTION TODAY WILL HAVE
PLENTY TO SAY ON OVERALL MASS FIELDS...BUT LARGE SCALE PATTERN FULLY
SUPPORTS A MORE SOUTH BASED PASSAGE TO ANY MCS TONIGHT...WITH JUST
SOME LIGHTER ACTIVITY THIS FAR NORTH. WILL TREND POPS AS SUCH...BUT
STILL LEAVE PLENTY OF OPPORTUNITY FOR FUTURE ADJUSTMENTS BASED ON
THIS AFTERNOONS UPSTREAM TRENDS. A MILD NIGHT...WITH LOWS IN THE 50S
AND LOWER 60S.
&&
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 250 AM EDT SAT JUN 15 2013
SUNDAY AND MONDAY...A WEAK AREA OF LOW PRESSURE WILL SLIDE EAST THRU
MICHIGAN EARLY SUNDAY MORNING. THIS LOW WILL GRADUALLY MERGE WITH
ANOTHER NRN STREAM LOW DROPPING SE INTO MICHIGAN SUNDAY AFTERNOON
AND EVENING. A COLD FRONT ASSOCIATED WITH THE SECOND LOW PRESSURE
SYSTEM WILL DROP INTO NRN MICHIGAN SUNDAY NIGHT...AND WILL THEN
SWEEP THRU LWR MICHIGAN ON MONDAY. LATEST NAM APPEARS TO BE TOO FAST
WITH THE PASSAGE OF THIS FRONT CONSIDERING THE FRONT BECOMES
ORIENTED WEST TO EAST ALONG THE UPPER LEVEL FLOW ONCE IT REACHES
UPPER MICHIGAN. ECMWF PROVIDES A SLOWER AND THUS MORE REASONABLE
SOLUTION...AND WILL LEAN IN THIS DIRECTION. CHANCE OF SHOWERS/STORMS
WILL LINGER INTO SUNDAY MORNING FOR MUCH OF OUR CWA AS THE INITIAL
SURFACE LOW EXITS LWR MICHIGAN. DIURNAL INSTABILITY COMBINED WITH
WEAK LAKE BREEZE BOUNDARIES AND LINGERING LOW LEVEL MOISTURE TO
PROVIDE SMALL CHANCES OF SHOWERS AND STORMS FOR ERN UPR AND NE LWR
MICHIGAN SUNDAY AFTERNOON. SECONDARY SURFACE LOW AND ASSOCIATED COLD
FRONT WILL DROP INTO ERN UPR AND FAR NRN LWR MICHIGAN SUNDAY
AFTERNOON/EVENING...PROVIDING ADDITIONAL FOCUS FOR CONVECTIVE
DEVELOPMENT TO PERSIST THRU THE NIGHT ACROSS LOCATIONS ALONG AND
NORTH OF M-32. BY MONDAY...THE SLOW-MOVING COLD FRONT WILL DROP THRU
THE REST OF OUR CWA...RESULTING IN CONTINUED CONVECTIVE DEVELOPMENT
THRU THE DAY. CHANCES OF SHOWERS AND STORMS WILL COME TO AN END THRU
MONDAY NIGHT AS THE COLD FRONT EXITS LWR MICHIGAN.
TUESDAY THRU FRIDAY...STRONG CANADIAN HIGH PRESSURE...SUBSIDENCE AND
DRY AIR WILL BUILD INTO THE GREAT LAKES TUESDAY INTO WEDNESDAY
BEHIND THE DEPARTING COLD FRONT. DRY WEATHER IS EXPECTED THRU THIS
TIME PERIOD...WITH TEMPS SEVERAL DEGREES BELOW NORMAL THANKS TO CAA.
WEAK AREA OF LOW PRESSURE WILL SLOWLY TRACK THRU ONTARIO AND INTO
QUEBEC WEDNESDAY NIGHT THRU FRIDAY...DRAGGING THE SRN END OF A WEAK
FRONT THRU NRN MICHIGAN. BOTH MOISTURE AND LIFT WILL BE LIMITED WITH
THIS WEAK FEATURE...BUT WILL INTRODUCE SMALL PRECIP CHANCES INTO THE
FORECAST FOR THIS TIMEFRAME AS THIS FRONT PASSES THRU THE REGION.
TEMPS WILL REBOUND TO NEAR NORMAL IN WEAK WAA AHEAD OF THIS FRONT.
INITIAL LOOK FOR NEXT WEEKEND SUGGESTS MAINLY DRY WEATHER WITH NEAR
NORMAL TEMPS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 700 AM EDT SAT JUN 15 2013
OVERALL CONDITIONS WILL REMAIN VFR THRU THE 24 HR TAF FORECAST
PERIOD. A THICK DECK OF MID CLOUDS WILL REMAIN OVERHEAD...AS
SCT/BKN LOW CLOUDS AT AROUND 5-6 KFT DEVELOPS TODAY AND TONIGHT.
CHANCES OF SHOWERS AND POSSIBLY A THUNDERSTORM WILL GRADUALLY
INCREASE AS WE HEAD INTO THIS AFTERNOON AND TONIGHT ALONG AND
AHEAD OF WEAK LOW PRESSURE TRACKING EAST THRU MICHIGAN. LIGHT
WINDS THIS MORNING WILL ONLY INCREASE TO LESS THAN 10 KTS FROM THE
SW BY THIS AFTERNOON...WITH SOME LAKE BREEZE DEVELOPMENT EXPECTED
ALONG THE LAKESHORES.
&&
.MARINE...
ISSUED AT 250 AM EDT SAT JUN 15 2013
LIGHT WINDS CONTINUE...WITH LOCAL LAKE BREEZE DEVELOPMENT
THIS AFTERNOON...ESPECIALLY OFF LAKE HURON. WEAK SURFACE TROUGH
PASSES THROUGH THE REGION LATE TONIGHT INTO EARLY SUNDAY...VEERING
SOUTHWEST FLOW TO WESTERLY. MARINE FOG EXPECTED TO DEVELOP LATER
TONIGHT INTO SUNDAY AS LOW LEVEL MOISTURE ADVECTION STRENGTHENS.
SHOWERS AND STORMS POSSIBLE TONIGHT...ALTHOUGH STRONGEST ACTIVITY
EXPECTED TO REMAIN ACROSS THE SOUTHERN LAKES. EARLY INDICATIONS ARE
FOR MAINLY LIGHT WINDS TO CONTINUE RIGHT THROUGH MUCH OF NEXT WORK
WEEK.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...JPB
SYNOPSIS...MLR
SHORT TERM...MSB
LONG TERM...MLR
AVIATION...MLR
MARINE...MSB
AREA FORECAST DISCUSSION
NWS GAYLORD MI
700 AM EDT SAT JUN 15 2013
.SYNOPSIS...
ISSUED AT 250 AM EDT SAT JUN 15 2013
CLOUDS WILL INCREASE TODAY AS A SERIES OF UPPER LEVEL DISTURBANCES
BRING A CHANCE OF SHOWERS AND THUNDERSTORMS TO NORTHERN MICHIGAN
BEGINNING THIS AFTERNOON AND CONTINUING THROUGH THE WEEKEND AND INTO
EARLY NEXT WORK WEEK.
&&
.UPDATE...
ISSUED AT 700 AM EDT SAT JUN 15 2013
WIDELY SCATTERED MID LEVEL RETURNS CONTINUE TO DRIFT SOUTH OF OUR
CWA EARLY THIS MORNING PER LATEST KAPX 88D BASE REF LOOP. ALL CIGS
REMAIN ABOVE 10 KFT SO FAR TODAY...BUT DO EXPECTED SOME LOW CLOUD
DEVELOPMENT AS WE HEAD INTO THIS AFTERNOON IN RESPONSE TO
GRADUALLY INCREASING LOW LEVEL MOISTURE AHEAD OF WEAK LOW PRESSURE
TRACKING TOWARD MICHIGAN. PRECIP CHANCES WILL GRADUALLY INCREASE
TOWARD AFTERNOON AS WELL...BUT ANY SHOWER OR THUNDERSTORM ACTIVITY
WILL REMAIN SCATTERED...WITH BETTER CHANCES AND HEAVIER PRECIP
REMAINING SOUTH OF OUR CWA. HAVE MADE SOME ADJUSTMENTS TO CLOUD
COVER BASED ON LATEST IR SATELLITE LOOP. OTHERWISE...CURRENT
FORECAST HIGHLIGHTS INCREASING SMALL CHANCES OF SHOWERS/STORMS
THIS AFTERNOON...WHICH IS STILL ON TARGET.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 250 AM EDT SAT JUN 15 2013
FIRST OF ALL...HATS OFF TO OLD MOTHER NATURE...DELIVERING ONE OF THE
FINER SUMMER DAYS YOU WILL SEE AROUND THESE PARTS YESTERDAY. DRY
AIRMASS RESPONSIBLE FOR SUCH FANTASTIC WEATHER STILL FIRMLY IN
CONTROL AT THIS EARLY HOUR...WITH EXPANSIVE SURFACE HIGH PRESSURE
EXTENDING FROM THE NORTHERN LAKES RIGHT DOWN INTO THE SOUTHEASTERN
STATES. 00Z RAOB PWAT ANALYSIS CONFIRMS SUCH...WITH CP AIRMASS
BRINGING SUB ONE INCH PWAT VALUES ACROSS THIS SAME REGION (RATHER
IMPRESSIVE FOR THIS TIME OF YEAR). UNFORTUNATELY...ONE DOES NOT HAVE
TO VENTURE TOO FAR WEST FOR SOME INCLEMENT WEATHER. BACKSIDE RETURN
FLOW ALREADY AMPING UP ACROSS THE WESTERN LAKES...WITH REAL-TIME OBS
AND HIGH RES RUC ANALYSIS SHOWING ELEVATED MOISTURE PLUME ALREADY
PUNCHING THROUGH WISCONSIN AND WESTERN UPPER MICHIGAN. LEADING
MOISTURE CONVERGENCE AXIS AND SUBTLE WAVE PIVOTING THROUGH BROADER
UPSTREAM RIDGING MANAGED TO KICK OFF SOME EVENING SHOWERS AND STORMS
TO OUR NORTHWEST...ALTHOUGH THESE HAVE LARGELY DIED OUT AS THEY
APPROACH OVERHEAD DEEP LAYER DRY WEDGE. THEME OF THIS SUMMER
CONTINUES...WITH THE MOST PROMINENT AREA OF SHOWERS AND STORMS
REMAINING SAFELY TO OUR SOUTHWEST WHERE NOCTURNALLY CHARGED LOW
LEVEL JET FORCED MASS CONVERGENCE AND DEEP INSTABILITY ARE BETTER
JUXTAPOSED. RADAR AND SATELLITE TRENDS BOTH SUGGEST THIS SHOULD
REMAIN THE CASE RIGHT THROUGH THE EARLY MORNING HOURS...LEAVING
MOSTLY DRY CONDITIONS ACROSS OUR AREA THROUGH AT LEAST THE FIRST
HALF OF THE MORNING. SHORT TERM FORECAST CONCERNS CENTER ON POSSIBLE
ADDITIONAL SHOWER AND STORM DEVELOPMENT TODAY AND TONIGHT.
GOING TO BE AWFULLY HARD TO BEAT YESTERDAY...AND......WE WON`T.
THAT SAID...UPSTREAM TRENDS AND PATTERN RECOGNITION SUPPORTS A
NOT-TO-SHABBY START TO THE WEEKEND. REMAIN LARGELY UNENTHUSED WITH
RAIN CHANCES TODAY...DESPITE STAGE RIGHT DEPARTURE OF CURRENT
SURFACE HIGH. UPSTREAM MID LEVEL RIDGING REPLACES ITS SURFACE
LIKENESS...ALTHOUGH DEAMPLIFYING AS IT DOES SO WITH ENERGY CUTTING
ACROSS SOUTHERN CANADA. UPPER LEVEL FORCING ARRIVES LATE VIA RER
UPPER JET DYNAMICS...MOST OF WHICH HOLDS OFF UNTIL THE OVERNIGHT
HOURS. PER THE USUAL...GUIDANCE JUST SEEMS MUCH TOO AGGRESSIVE
DRIVING LOW LEVEL MOISTURE THIS FAR NORTH...ESPECIALLY GIVEN
ANTECEDENT DRY CONDITIONS AND PROPENSITY FOR MOISTURE STEALING
CONVECTION TO CONTINUE TO FIRE WELL TO OUR SOUTHWEST. MODIFYING
MODEL SUGGESTED SOUNDINGS FOR SUCH SHOWS SIGNIFICANT MID LEVEL CAP
UNTIL VERY LATE...AND LITTLE...IF ANY ML CAPE DEVELOPMENT. CORE OF
MORE IMPRESSIVE MID LEVEL LAPSE RATES REMAINS JUST UPSTREAM ACROSS
WISCONSIN. THETA-E RIDGING DOES ADVANCE EAST WITH TIME....CROSSING
OUR AREA LATE MORNING THROUGH THE AFTERNOON. EVEN THIS...HOWEVER...
WILL BE LOSING DEFINITION WITH TIME. NO DOUBT CLOUDS WILL BE ON THE
INCREASE AS UPSTREAM MID LEVEL MOISTURE PLUME ADVANCES EAST...BUT
GIVEN ALL THE ABOVE...THE PROSPECTS FOR ANY MEANINGFUL RAINS ARE
MUCH LESS THAN IDEAL. SUPPOSE A SPRINKLE/VERY LIGHT SHOWER IS
PLAUSIBLE ALONG THETA-E GRADIENT OR FROM WHAT`S EVER LEFT OF
UPSTREAM ACTIVITY. TEMPTED TO PULL POPS ALTOGETHER...BUT GIVEN SOME
LINGERING UNCERTAINTY...WILL JUST SIMPLY MAINTAIN INHERITED LOW
CHANCE MENTION. DESPITE CLOUDS...THERMAL PROFILES SUPPORT A RATHER
MILD DAY...WITH HIGHS WELL INTO THE 70S ACROSS MOST AREAS. LIGHT
PRESSURE GRADIENT SUPPORTS LATE MORNING AND AFTERNOON LAKE BREEZE
DEVELOPMENT...KEEPING SHORELINE AREAS A FEW DEGREES COOLER.
THINGS TRY TO CONGEAL TO BRING BETTER RAIN CHANCES TONIGHT...WITH
SOMEWHAT DEEPER LOW LEVEL MOISTURE OVERTOPPED BY UPPER JET DYNAMICS.
NOTHING OVERLY IMPRESSIVE THROUGH THE MID LEVELS...WITH PERHAPS A
CONVECTIVELY AUGMENTED VORT LOBE/SUBTLE WAVE RACING EAST ACROSS THE
SOUTHERN THIRD OF THE AREA. PATTERN RECOGNITION CONTINUES TO SUPPORT
SOUTHERN LAKES/NORTHERN OHIO VALLEY MCS DEVELOPMENT ON NOSE OF
STRONGER LOW LEVEL JET. SOME GUIDANCE SEEMS OVERLY AGGRESSIVE
DRIVING CONVECTIVE DEVELOPMENT NORTH...ESPECIALLY THE 00Z GFS AND
12Z ECMWF. DEEP LAYER FLOW SIMPLY DOES NOT BACK ENOUGH TO SUPPORT
THESE NORTH BASED TRENDS. CONVECTIVE EVOLUTION TODAY WILL HAVE
PLENTY TO SAY ON OVERALL MASS FIELDS...BUT LARGE SCALE PATTERN FULLY
SUPPORTS A MORE SOUTH BASED PASSAGE TO ANY MCS TONIGHT...WITH JUST
SOME LIGHTER ACTIVITY THIS FAR NORTH. WILL TREND POPS AS SUCH...BUT
STILL LEAVE PLENTY OF OPPORTUNITY FOR FUTURE ADJUSTMENTS BASED ON
THIS AFTERNOONS UPSTREAM TRENDS. A MILD NIGHT...WITH LOWS IN THE 50S
AND LOWER 60S.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 250 AM EDT SAT JUN 15 2013
SUNDAY AND MONDAY...A WEAK AREA OF LOW PRESSURE WILL SLIDE EAST THRU
MICHIGAN EARLY SUNDAY MORNING. THIS LOW WILL GRADUALLY MERGE WITH
ANOTHER NRN STREAM LOW DROPPING SE INTO MICHIGAN SUNDAY AFTERNOON
AND EVENING. A COLD FRONT ASSOCIATED WITH THE SECOND LOW PRESSURE
SYSTEM WILL DROP INTO NRN MICHIGAN SUNDAY NIGHT...AND WILL THEN
SWEEP THRU LWR MICHIGAN ON MONDAY. LATEST NAM APPEARS TO BE TOO FAST
WITH THE PASSAGE OF THIS FRONT CONSIDERING THE FRONT BECOMES
ORIENTED WEST TO EAST ALONG THE UPPER LEVEL FLOW ONCE IT REACHES
UPPER MICHIGAN. ECMWF PROVIDES A SLOWER AND THUS MORE REASONABLE
SOLUTION...AND WILL LEAN IN THIS DIRECTION. CHANCE OF SHOWERS/STORMS
WILL LINGER INTO SUNDAY MORNING FOR MUCH OF OUR CWA AS THE INITIAL
SURFACE LOW EXITS LWR MICHIGAN. DIURNAL INSTABILITY COMBINED WITH
WEAK LAKE BREEZE BOUNDARIES AND LINGERING LOW LEVEL MOISTURE TO
PROVIDE SMALL CHANCES OF SHOWERS AND STORMS FOR ERN UPR AND NE LWR
MICHIGAN SUNDAY AFTERNOON. SECONDARY SURFACE LOW AND ASSOCIATED COLD
FRONT WILL DROP INTO ERN UPR AND FAR NRN LWR MICHIGAN SUNDAY
AFTERNOON/EVENING...PROVIDING ADDITIONAL FOCUS FOR CONVECTIVE
DEVELOPMENT TO PERSIST THRU THE NIGHT ACROSS LOCATIONS ALONG AND
NORTH OF M-32. BY MONDAY...THE SLOW-MOVING COLD FRONT WILL DROP THRU
THE REST OF OUR CWA...RESULTING IN CONTINUED CONVECTIVE DEVELOPMENT
THRU THE DAY. CHANCES OF SHOWERS AND STORMS WILL COME TO AN END THRU
MONDAY NIGHT AS THE COLD FRONT EXITS LWR MICHIGAN.
TUESDAY THRU FRIDAY...STRONG CANADIAN HIGH PRESSURE...SUBSIDENCE AND
DRY AIR WILL BUILD INTO THE GREAT LAKES TUESDAY INTO WEDNESDAY
BEHIND THE DEPARTING COLD FRONT. DRY WEATHER IS EXPECTED THRU THIS
TIME PERIOD...WITH TEMPS SEVERAL DEGREES BELOW NORMAL THANKS TO CAA.
WEAK AREA OF LOW PRESSURE WILL SLOWLY TRACK THRU ONTARIO AND INTO
QUEBEC WEDNESDAY NIGHT THRU FRIDAY...DRAGGING THE SRN END OF A WEAK
FRONT THRU NRN MICHIGAN. BOTH MOISTURE AND LIFT WILL BE LIMITED WITH
THIS WEAK FEATURE...BUT WILL INTRODUCE SMALL PRECIP CHANCES INTO THE
FORECAST FOR THIS TIMEFRAME AS THIS FRONT PASSES THRU THE REGION.
TEMPS WILL REBOUND TO NEAR NORMAL IN WEAK WAA AHEAD OF THIS FRONT.
INITIAL LOOK FOR NEXT WEEKEND SUGGESTS MAINLY DRY WEATHER WITH NEAR
NORMAL TEMPS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 700 AM EDT SAT JUN 15 2013
OVERALL CONDITIONS WILL REMAIN VFR THRU THE 24 HR TAF FORECAST
PERIOD. A THICK DECK OF MID CLOUDS WILL REMAIN OVERHEAD...AS
SCT/BKN LOW CLOUDS AT AROUND 5-6 KFT DEVELOPS TODAY AND TONIGHT.
CHANCES OF SHOWERS AND POSSIBLY A THUNDERSTORM WILL GRADUALLY
INCREASE AS WE HEAD INTO THIS AFTERNOON AND TONIGHT ALONG AND
AHEAD OF WEAK LOW PRESSURE TRACKING EAST THRU MICHIGAN. LIGHT
WINDS THIS MORNING WILL ONLY INCREASE TO LESS THAN 10 KTS FROM THE
SW BY THIS AFTERNOON...WITH SOME LAKE BREEZE DEVELOPMENT EXPECTED
ALONG THE LAKESHORES.
&&
.MARINE...
ISSUED AT 250 AM EDT SAT JUN 15 2013
LIGHT WINDS CONTINUE...WITH LOCAL LAKE BREEZE DEVELOPMENT
THIS AFTERNOON...ESPECIALLY OFF LAKE HURON. WEAK SURFACE TROUGH
PASSES THROUGH THE REGION LATE TONIGHT INTO EARLY SUNDAY...VEERING
SOUTHWEST FLOW TO WESTERLY. MARINE FOG EXPECTED TO DEVELOP LATER
TONIGHT INTO SUNDAY AS LOW LEVEL MOISTURE ADVECTION STRENGTHENS.
SHOWERS AND STORMS POSSIBLE TONIGHT...ALTHOUGH STRONGEST ACTIVITY
EXPECTED TO REMAIN ACROSS THE SOUTHERN LAKES. EARLY INDICATIONS ARE
FOR MAINLY LIGHT WINDS TO CONTINUE RIGHT THROUGH MUCH OF NEXT WORK
WEEK.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...MR
SYNOPSIS...MR
SHORT TERM...MB
LONG TERM...MR
AVIATION...MR
MARINE...MB
AREA FORECAST DISCUSSION
NWS GAYLORD MI
250 AM EDT SAT JUN 15 2013
.SYNOPSIS...
ISSUED AT 250 AM EDT SAT JUN 15 2013
CLOUDS WILL INCREASE TODAY AS A SERIES OF UPPER LEVEL DISTURBANCES
BRING A CHANCE OF SHOWERS AND THUNDERSTORMS TO NORTHERN MICHIGAN
BEGINNING THIS AFTERNOON AND CONTINUING THROUGH THE WEEKEND AND INTO
EARLY NEXT WORK WEEK.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 250 AM EDT SAT JUN 15 2013
FIRST OF ALL...HATS OFF TO OLD MOTHER NATURE...DELIVERING ONE OF THE
FINER SUMMER DAYS YOU WILL SEE AROUND THESE PARTS YESTERDAY. DRY
AIRMASS RESPONSIBLE FOR SUCH FANTASTIC WEATHER STILL FIRMLY IN
CONTROL AT THIS EARLY HOUR...WITH EXPANSIVE SURFACE HIGH PRESSURE
EXTENDING FROM THE NORTHERN LAKES RIGHT DOWN INTO THE SOUTHEASTERN
STATES. 00Z RAOB PWAT ANALYSIS CONFIRMS SUCH...WITH CP AIRMASS
BRINGING SUB ONE INCH PWAT VALUES ACROSS THIS SAME REGION (RATHER
IMPRESSIVE FOR THIS TIME OF YEAR). UNFORTUNATELY...ONE DOES NOT HAVE
TO VENTURE TOO FAR WEST FOR SOME INCLEMENT WEATHER. BACKSIDE RETURN
FLOW ALREADY AMPING UP ACROSS THE WESTERN LAKES...WITH REAL-TIME OBS
AND HIGH RES RUC ANALYSIS SHOWING ELEVATED MOISTURE PLUME ALREADY
PUNCHING THROUGH WISCONSIN AND WESTERN UPPER MICHIGAN. LEADING
MOISTURE CONVERGENCE AXIS AND SUBTLE WAVE PIVOTING THROUGH BROADER
UPSTREAM RIDGING MANAGED TO KICK OFF SOME EVENING SHOWERS AND STORMS
TO OUR NORTHWEST...ALTHOUGH THESE HAVE LARGELY DIED OUT AS THEY
APPROACH OVERHEAD DEEP LAYER DRY WEDGE. THEME OF THIS SUMMER
CONTINUES...WITH THE MOST PROMINENT AREA OF SHOWERS AND STORMS
REMAINING SAFELY TO OUR SOUTHWEST WHERE NOCTURNALLY CHARGED LOW
LEVEL JET FORCED MASS CONVERGENCE AND DEEP INSTABILITY ARE BETTER
JUXTAPOSED. RADAR AND SATELLITE TRENDS BOTH SUGGEST THIS SHOULD
REMAIN THE CASE RIGHT THROUGH THE EARLY MORNING HOURS...LEAVING
MOSTLY DRY CONDITIONS ACROSS OUR AREA THROUGH AT LEAST THE FIRST
HALF OF THE MORNING. SHORT TERM FORECAST CONCERNS CENTER ON POSSIBLE
ADDITIONAL SHOWER AND STORM DEVELOPMENT TODAY AND TONIGHT.
GOING TO BE AWFULLY HARD TO BEAT YESTERDAY...AND......WE WON`T.
THAT SAID...UPSTREAM TRENDS AND PATTERN RECOGNITION SUPPORTS A
NOT-TO-SHABBY START TO THE WEEKEND. REMAIN LARGELY UNENTHUSED WITH
RAIN CHANCES TODAY...DESPITE STAGE RIGHT DEPARTURE OF CURRENT
SURFACE HIGH. UPSTREAM MID LEVEL RIDGING REPLACES ITS SURFACE
LIKENESS...ALTHOUGH DEAMPLIFYING AS IT DOES SO WITH ENERGY CUTTING
ACROSS SOUTHERN CANADA. UPPER LEVEL FORCING ARRIVES LATE VIA RER
UPPER JET DYNAMICS...MOST OF WHICH HOLDS OFF UNTIL THE OVERNIGHT
HOURS. PER THE USUAL...GUIDANCE JUST SEEMS MUCH TOO AGGRESSIVE
DRIVING LOW LEVEL MOISTURE THIS FAR NORTH...ESPECIALLY GIVEN
ANTECEDENT DRY CONDITIONS AND PROPENSITY FOR MOISTURE STEALING
CONVECTION TO CONTINUE TO FIRE WELL TO OUR SOUTHWEST. MODIFYING
MODEL SUGGESTED SOUNDINGS FOR SUCH SHOWS SIGNIFICANT MID LEVEL CAP
UNTIL VERY LATE...AND LITTLE...IF ANY ML CAPE DEVELOPMENT. CORE OF
MORE IMPRESSIVE MID LEVEL LAPSE RATES REMAINS JUST UPSTREAM ACROSS
WISCONSIN. THETA-E RIDGING DOES ADVANCE EAST WITH TIME....CROSSING
OUR AREA LATE MORNING THROUGH THE AFTERNOON. EVEN THIS...HOWEVER...
WILL BE LOSING DEFINITION WITH TIME. NO DOUBT CLOUDS WILL BE ON THE
INCREASE AS UPSTREAM MID LEVEL MOISTURE PLUME ADVANCES EAST...BUT
GIVEN ALL THE ABOVE...THE PROSPECTS FOR ANY MEANINGFUL RAINS ARE
MUCH LESS THAN IDEAL. SUPPOSE A SPRINKLE/VERY LIGHT SHOWER IS
PLAUSIBLE ALONG THETA-E GRADIENT OR FROM WHAT`S EVER LEFT OF
UPSTREAM ACTIVITY. TEMPTED TO PULL POPS ALTOGETHER...BUT GIVEN SOME
LINGERING UNCERTAINTY...WILL JUST SIMPLY MAINTAIN INHERITED LOW
CHANCE MENTION. DESPITE CLOUDS...THERMAL PROFILES SUPPORT A RATHER
MILD DAY...WITH HIGHS WELL INTO THE 70S ACROSS MOST AREAS. LIGHT
PRESSURE GRADIENT SUPPORTS LATE MORNING AND AFTERNOON LAKE BREEZE
DEVELOPMENT...KEEPING SHORELINE AREAS A FEW DEGREES COOLER.
THINGS TRY TO CONGEAL TO BRING BETTER RAIN CHANCES TONIGHT...WITH
SOMEWHAT DEEPER LOW LEVEL MOISTURE OVERTOPPED BY UPPER JET DYNAMICS.
NOTHING OVERLY IMPRESSIVE THROUGH THE MID LEVELS...WITH PERHAPS A
CONVECTIVELY AUGMENTED VORT LOBE/SUBTLE WAVE RACING EAST ACROSS THE
SOUTHERN THIRD OF THE AREA. PATTERN RECOGNITION CONTINUES TO SUPPORT
SOUTHERN LAKES/NORTHERN OHIO VALLEY MCS DEVELOPMENT ON NOSE OF
STRONGER LOW LEVEL JET. SOME GUIDANCE SEEMS OVERLY AGGRESSIVE
DRIVING CONVECTIVE DEVELOPMENT NORTH...ESPECIALLY THE 00Z GFS AND
12Z ECMWF. DEEP LAYER FLOW SIMPLY DOES NOT BACK ENOUGH TO SUPPORT
THESE NORTH BASED TRENDS. CONVECTIVE EVOLUTION TODAY WILL HAVE
PLENTY TO SAY ON OVERALL MASS FIELDS...BUT LARGE SCALE PATTERN FULLY
SUPPORTS A MORE SOUTH BASED PASSAGE TO ANY MCS TONIGHT...WITH JUST
SOME LIGHTER ACTIVITY THIS FAR NORTH. WILL TREND POPS AS SUCH...BUT
STILL LEAVE PLENTY OF OPPORTUNITY FOR FUTURE ADJUSTMENTS BASED ON
THIS AFTERNOONS UPSTREAM TRENDS. A MILD NIGHT...WITH LOWS IN THE 50S
AND LOWER 60S.
&&
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 250 AM EDT SAT JUN 15 2013
SUNDAY AND MONDAY...A WEAK AREA OF LOW PRESSURE WILL SLIDE EAST THRU
MICHIGAN EARLY SUNDAY MORNING. THIS LOW WILL GRADUALLY MERGE WITH
ANOTHER NRN STREAM LOW DROPPING SE INTO MICHIGAN SUNDAY AFTERNOON
AND EVENING. A COLD FRONT ASSOCIATED WITH THE SECOND LOW PRESSURE
SYSTEM WILL DROP INTO NRN MICHIGAN SUNDAY NIGHT...AND WILL THEN
SWEEP THRU LWR MICHIGAN ON MONDAY. LATEST NAM APPEARS TO BE TOO FAST
WITH THE PASSAGE OF THIS FRONT CONSIDERING THE FRONT BECOMES
ORIENTED WEST TO EAST ALONG THE UPPER LEVEL FLOW ONCE IT REACHES
UPPER MICHIGAN. ECMWF PROVIDES A SLOWER AND THUS MORE REASONABLE
SOLUTION...AND WILL LEAN IN THIS DIRECTION. CHANCE OF SHOWERS/STORMS
WILL LINGER INTO SUNDAY MORNING FOR MUCH OF OUR CWA AS THE INITIAL
SURFACE LOW EXITS LWR MICHIGAN. DIURNAL INSTABILITY COMBINED WITH
WEAK LAKE BREEZE BOUNDARIES AND LINGERING LOW LEVEL MOISTURE TO
PROVIDE SMALL CHANCES OF SHOWERS AND STORMS FOR ERN UPR AND NE LWR
MICHIGAN SUNDAY AFTERNOON. SECONDARY SURFACE LOW AND ASSOCIATED COLD
FRONT WILL DROP INTO ERN UPR AND FAR NRN LWR MICHIGAN SUNDAY
AFTERNOON/EVENING...PROVIDING ADDITIONAL FOCUS FOR CONVECTIVE
DEVELOPMENT TO PERSIST THRU THE NIGHT ACROSS LOCATIONS ALONG AND
NORTH OF M-32. BY MONDAY...THE SLOW-MOVING COLD FRONT WILL DROP THRU
THE REST OF OUR CWA...RESULTING IN CONTINUED CONVECTIVE DEVELOPMENT
THRU THE DAY. CHANCES OF SHOWERS AND STORMS WILL COME TO AN END THRU
MONDAY NIGHT AS THE COLD FRONT EXITS LWR MICHIGAN.
TUESDAY THRU FRIDAY...STRONG CANADIAN HIGH PRESSURE...SUBSIDENCE AND
DRY AIR WILL BUILD INTO THE GREAT LAKES TUESDAY INTO WEDNESDAY
BEHIND THE DEPARTING COLD FRONT. DRY WEATHER IS EXPECTED THRU THIS
TIME PERIOD...WITH TEMPS SEVERAL DEGREES BELOW NORMAL THANKS TO CAA.
WEAK AREA OF LOW PRESSURE WILL SLOWLY TRACK THRU ONTARIO AND INTO
QUEBEC WEDNESDAY NIGHT THRU FRIDAY...DRAGGING THE SRN END OF A WEAK
FRONT THRU NRN MICHIGAN. BOTH MOISTURE AND LIFT WILL BE LIMITED WITH
THIS WEAK FEATURE...BUT WILL INTRODUCE SMALL PRECIP CHANCES INTO THE
FORECAST FOR THIS TIMEFRAME AS THIS FRONT PASSES THRU THE REGION.
TEMPS WILL REBOUND TO NEAR NORMAL IN WEAK WAA AHEAD OF THIS FRONT.
INITIAL LOOK FOR NEXT WEEKEND SUGGESTS MAINLY DRY WEATHER WITH NEAR
NORMAL TEMPS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 135 AM EDT SAT JUN 15 2013
VFR CONDITIONS EXPECTED TO CONTINUE THROUGH THIS TAF PERIOD.
INCREASING MOISTURE MAY BRING A FEW LIGHT SHOWERS LATER THIS
AFTERNOON. STRONGER FORCING ARRIVES TONIGHT...ALTHOUGH TRENDS
SUPPORT BETTER SHOWER AND STORM POTENTIAL REMAINING OFF TO THE
SOUTH OF THE TAF SITES. LOW LEVEL DRY AIR LOOKS TO KEEP CIGS
WITHIN VFR CATEGORY. WILL NOT INCLUDE THUNDER MENTION UNTIL
UPSTREAM CONVECTIVE TRENDS BECOME ESTABLISHED. LIGHT WINDS...WITH
LOCAL LAKE BREEZE DEVELOPMENT THIS AFTERNOON...WILL CONTINUE.
&&
.MARINE...
ISSUED AT 250 AM EDT SAT JUN 15 2013
LIGHT WINDS CONTINUE...WITH LOCAL LAKE BREEZE DEVELOPMENT
THIS AFTERNOON...ESPECIALLY OFF LAKE HURON. WEAK SURFACE TROUGH
PASSES THROUGH THE REGION LATE TONIGHT INTO EARLY SUNDAY...VEERING
SOUTHWEST FLOW TO WESTERLY. MARINE FOG EXPECTED TO DEVELOP LATER
TONIGHT INTO SUNDAY AS LOW LEVEL MOISTURE ADVECTION STRENGTHENS.
SHOWERS AND STORMS POSSIBLE TONIGHT...ALTHOUGH STRONGEST ACTIVITY
EXPECTED TO REMAIN ACROSS THE SOUTHERN LAKES. EARLY INDICATIONS ARE
FOR MAINLY LIGHT WINDS TO CONTINUE RIGHT THROUGH MUCH OF NEXT WORK
WEEK.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
SYNOPSIS...MR
SHORT TERM...MB
LONG TERM...MR
AVIATION...MB
MARINE...MB
AREA FORECAST DISCUSSION
NWS DULUTH MN
114 PM CDT SAT JUN 15 2013
.AVIATION...MAINLY VFR CONDITONS AT TAF SITES EXPECT FOR LIFR CIGS
AT HYR. THIS WILL IMPROVE TO VFR BY LATE AFTERNOON AS CLEARING
WILL MOVE INTO THE AREA. THERE IS AN AREA OF SHOWERS MOVING
THROUGH NE MN ATTM WITH MVFR CIGS WITH RAIN. THERE WILL BE
A POSSIBILITY OF SHOWERS THIS EVENING WITH CLEAR TOWARD MIDNIGHT.
VFR CONDITIONS WILL CONTINUE INTO SUNDAY MORNING.
&&
.PREV DISCUSSION... /ISSUED 1056 AM CDT SAT JUN 15 2013/
UPDATE...
RATHER COMPLEX FORECAST SCENARIO FOR THE FIRST 12 HOURS THIS
MORNING WITH SOMEWHAT LOW CONFIDENCE ON EXACT PLACEMENT OF
REDEVELOPMENT OF SHOWERS/TSTORMS TODAY/TONIGHT. DEEP LAYER CYCLONE
HAS CLOSED OFF OVER SASKATCHEWAN THIS MORNING..WITH DRY SLOT/PV
LOBE CLEARLY EVIDENT IN WV IMAGERY WRAPPING AROUND THE SOUTHEAST
PERIPHERY OF THE CIRCULATION. THE INITIAL ROUND OF SHOWERS/TSTORMS
OVERNIGHT ASSOCIATED WITH WARM/MOIST ADVECTION HAS MOVED EAST OF
THE AREA..BUT WITH THE MAIN PUSH ON THE DRY SLOT BECOMING MORE
NORTHEASTERLY THIS MORNING..THE EASTWARD PROGRESS OF THE LOW
LEVEL FRONTAL ZONE AND INSTABILITY AXIS HAS SLOWED OR EVEN STALLED
ACROSS THE DLH CWA AS A SECONDARY WAVE ROTATES EASTWARD ACROSS THE
DAKOTAS.
AN AXIS OF SHOWERS HAS BEEN EVIDENT ALL MORNING FROM NRN SD INTO
WRN MN. THESE SHOWERS ARE HIGH BASED..AND HAVE BEEN LOCATED ALONG
THE LEADING EDGE OF THE MID LEVEL PV LOBE..AND ALSO APPEAR TO BE
GETTING SOME ASSISTANCE IN MAINTENANCE FROM MID LEVEL FGEN. OVER
THE PAST HOUR..THERE HAS BEEN SOME INCREASE IN COVERAGE JUST TO
THE SW OF THE BRAINERD AREA..AS A FLUX OF MOISTURE MOVES NORTHWARD
INTO THIS UVM FORCING ZONE FROM THE NORTHERN EXTENT OF THE
STRATIFORM RAIN AREA OF LARGE MCS IN THE SIOUX FALLS AREA. MAIN
UNCERTAINTY FOR THE REST OF THE DAY REVOLVES AROUND TWO FACTORS 1)
HOW FAR NORTH/EAST WILL THE EXISTING SHOWERS PERSIST..AND 2) WILL
THERE BE ADDITIONAL REDEVELOPMENT OVER NRN MN WHERE STRONGER FLOW
AND SUN WILL RESULT IN DEEP MIXING ALONG NORTHERN END OF
INSTABILITY AXIS.
THERE IS FAIRLY WIDESPREAD DIFFERENCE IN THE SHORT RANGE
GUIDANCE..WITH SOME MODELS WANTING TO DRY THINGS OUT COMPLETELY
ACROSS THE NORTH..WHILE OTHERS DEVELOP QPF. SIMILAR SPREAD IN
SOLUTIONS OVER THE SOUTH WHERE THE HRRR IN PARTICULAR WANTS TO
SPREAD RAIN ACROSS MUCH OF THE SOUTHERN CWA BY MID AFTERNOON
EVOLVING OUT OF THE ONGOING MCS OVER SRN MN/NRN IA. IF ANYTHING
WERE TO DEVELOP ACROSS THE NORTH..DEEP LAYER SHEAR AND STEEP LAPSE
RATES SUGGEST AT LEAST A MARGINAL HAIL/WIND THREAT AND SOME
ORGANIZATION FOR THE STRONGEST STORMS.
FOR NOW..WE HAVE EXPANDED POPS OVER MOST OF THE CWA FOR THIS
AFTERNOON TO AT LEAST MAINTAIN A MENTION OF ADDITIONAL
REDEVELOPMENT. BUT..WITH THE EXCEPTION OF PARTS OF NW WI..WE HAVE
KEPT THEM 15-25 PERCENT FOR NOW. LOOKING AT CURRENT RADAR TRENDS
HOWEVER..WE MAY NEED TO ADJUST UPWARD EVEN MORE ACROSS WRN/SW
PARTS OF THE CWA. ALSO MADE SOME MINOR TWEAKS TO TEMPS/SKY COVER
AND WINDS TO ACCOUNT FOR HIGHER CLOUD COVERAGE AND SLOWER CLEARING
TREND IN ALL LOCATIONS EXCEPT FOR THE FAR NW PART OF THE CWA. ALSO
HELD ON TO EASTERLY WIND COMPONENT OVER LK SUPERIOR UNTIL LATE
AFTERNOON WHEN PRESSURE RISE CENTER FINALLY IS FORECAST TO MOVE
EAST OF THE TWIN PORTS. UNTIL THEN..EAST WINDS AND TEMPS IN THE
40S ARE LIKELY TO HOLD FIRM IN AREAS IMMEDIATELY ADJACENT TO THE
LAKE. UPDATES ARE ALREADY AVAILABLE.
PREV DISCUSSION... /ISSUED 631 AM CDT SAT JUN 15 2013/
AVIATION...12Z TAFS
SCATTERED SHOWERS AND A FEW THUNDERSTORMS CONTINUED OVER THE
ARROWHEAD SOUTH OVER PORTIONS OF NORTHWEST WISCONSIN EARLY THIS
MORNING. MUCH OF THIS ACTIVITY WILL MOVE OFF TO THE EAST OVER THE
NEXT 2-3 HOURS. THERE WERE SOME PATCHY MVFR CEILINGS OUT
THERE...AND THEY MAY IMPACT THE TAF SITES THROUGH 15Z.
ANOTHER AREAS OF LIGHT SHOWERS WERE OCCURRING IN AN AREA OF MID
LEVEL FGEN. THE RAP WAS DOING AN DECENT JOB DEPICTING THESE
SHOWERS...AND THEY MAY IMPACT KBRD/KHIB/KDLH EARLY TO MID
AFTERNOON...AND KHYR LATER THIS AFTERNOON/EVENING. AT THIS
TIME...WE DID NOT ADD A MENTION AS COVERAGE SHOULD BE LIMITED.
WE MAY NEED TO UPDATE THE TAF ONCE CERTAINTY INCREASES ON WHEN THE
SHOWERS WILL MOVE IN.
PREV DISCUSSION... /ISSUED 354 AM CDT SAT JUN 15 2013/
CURRENT...WARM ADVECTION REGIME CONTINUES ACROSS THE CWA AHEAD
OF APPROACHING FRONTAL BDRY. AN AREA OF CONVECTION STRETCHES FROM
THE ARROWHEAD TO NORTHWEST WISCONSIN AS OF MID MORNING. THIS
APPEARS TO BE ASSOCIATED WITH THE 70H THETAE RIDGE. A FEW STORMS
HAVE PUSHED THEIR 50DBZ CORES TO 30/33K FT OVER CENTRAL ST LOUIS
COUNTY BUT ONLY PEA SIZED HAIL REPORTED AT THIS TIME. INITIAL BAND
OF CONVECTION HAS OUTRUN BEST THERMODYNAMICS WITH A FEW CELLS
REDEVELOPING OVER WRN CWA CLOSER TO ACTUAL FRONTAL BDRY. TEMPS RANGE
FROM MID 60S OVER SRN TIER OF CWA TO 40S NEAR LAKE SUPERIOR.
TODAY...FRNTL BDRY WILL MOVE RATHER SLOWLY EAST ACROSS THE CWA
TODAY. LINGERING RW/TRW ARE POSSIBLE FROM ARROWHEAD INTO NWRN
WISCONSIN. INSTABILITY/DEEP LAYER SHEAR VALUES STILL SUPPORTIVE OF
POTENTIAL FOR A FEW STRONG STORMS. MAX TEMPS WILL RISE TO ABOVE
CLIMO VALUES. HI RES DLHWRF SHOWS A PUSH OF WARMER OFFSHORE FLOW
LATE TODAY AFTER COOLER ONSHORE FLOW INITIALLY.
TONIGHT/TOMORROW...FRNTL BDRY PUSHES FARTHER SOUTH AND EAST OF
CWA TONIGHT AS DEEP LAYER DRYING INCREASES TEMPORARILY. AN
ELONGATED MID LVL TROF NORTH OF THE BORDER WILL MOVE SOUTH
TOMORROW. A SFC COLD FRONT WILL ACT IN CONJUNCTION WITH AN
INCREASE IN MOISTURE AND INCREASE THE LIKELIHOOD OF RW/TRW SUNDAY
ACROSS MOST OF THE MN ZONES. MDLS DIFFER ON HOW FAR SOUTH
SUFFICIENT MOISTURE PUSHES. HAVE OPTED FOR THE CONSENSUS BETWEEN
THE MORE AGGRESSIVE NAM AND THE MORE NRN SOLUTION PROVIDED BY THE
ECMWF. MAX TEMPS SHOULD CLIMB INTO LOW 80S ACROSS SRN CWA WITH MID
70S ELSEWHERE.
EXTENDED...SUNDAY NIGHT THROUGH FRIDAY.
A SHORTWAVE AND INVERTED SURFACE TROUGH WILL KEEP SHOWERS AND
THUNDERSTORMS IN THE FORECAST SUNDAY NIGHT INTO MONDAY...ALTHOUGH
PROBABILITIES WILL BE DIMINISHING ON MONDAY AS HIGH PRESSURE STARTS
TO MOVE INTO THE NORTHLAND.
HIGH PRESSURE SHOULD PROVIDE DRY WEATHER MONDAY NIGHT INTO TUESDAY.
A RIDGE ALOFT WILL EXTEND NORTH THROUGH THE NORTHERN PLAINS TUESDAY
NIGHT WITH IT MOVING EAST AND FLATTENING BY FRIDAY. THE GFS SHOWS A
SHORTWAVE MOVING THROUGH THE RIDGE PROVIDING A CHANCE FOR
SHOWERS/STORMS OVER NORTHERN MINNESOTA...WITH THE ECMWF DRY. WE
FOLLOWED CLOSER TO THE GFS AT THIS TIME. WE HAVE LOW POPS INTO
FRIDAY FOR SOME SHOWERS/STORMS...BUT CONFIDENCE IS LOW FROM TUESDAY
NIGHT THROUGH FRIDAY ON RAIN CHANCES.
TEMPERATURES WILL GRADUALLY WARM THROUGH THE PERIOD...STARTING OUT
IN THE UPPER SIXTIES TO LOWER SEVENTIES MONDAY...AND WARMING TO 75
TO 80 BY THURSDAY.
AVIATION...06Z TAF ISSUANCE. MID LEVEL CEILINGS WILL PREVAIL
THROUGH NIGHT WITH SCT SHOWERS/STORMS AND POSSIBLE BRIEF MVFR
CIGS. THE EXCEPTION WILL BE AT KBRD WHERE THE THUNDER THREAT IS
MINIMAL. WINDS WILL TURN OUT OF THE SOUTHWEST THEN WEST...SATURDAY
MORNING...WITH GRADUALLY CLEARING SKIES FROM THE WEST THROUGH THE
DAY SAT.
&&
.POINT TEMPS/POPS...
DLH 72 54 78 53 / 30 20 20 50
INL 77 50 77 49 / 20 20 40 40
BRD 77 55 80 57 / 40 10 10 30
HYR 77 54 81 55 / 20 20 10 50
ASX 72 52 77 52 / 30 20 20 50
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...MILLER
LONG TERM....STEWART
AVIATION...STEWART
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
101 PM CDT SAT JUN 15 2013
.UPDATE...
ISSUED AT 1035 AM CDT SAT JUN 15 2013
MADE SOME CHANGES TO THE POPS THIS MORNING TO INCREASE THEM
CONSIDERABLY TROUGH THE AFTERNOON FROM SOUTH CENTRAL MN INTO ERN
MN AND WESTERN WI. THIS WAS BASED QUITE HEAVILY ON THE HRRR /WHICH
HAS BEEN VERY CONSISTENT THROUGH THE MORNING/ AND THE 15.00 RUN OF
THE MPXWRF.
FRONT IS JUST NOW PUSHING THROUGH THE I-35 CORRIDOR IN TERMS OF A
WIND SHIFT...BUT DEWPOINT DROP IS TRAILING THE WIND SHIFT BY A
GOOD 75+ MILES TO THE WEST. MESO ANALYSIS PAGE SHOWING 500-1500
J/KG OF MLCAPE AT 15Z OUT AHEAD OF THE BOUNDARY...WITH CIN
BEGINNING TO DECREASE. THIS INSTABILITY/WEAK STABILITY AHEAD OF
THE DEWP DROP IS LIKELY WHY THE HRRR CONTINUES TO SHOW DEEP
CONVECTION INITIATING WEST OF THE TWIN CITIES BETWEEN 16Z AND 17Z.
DO PUT SOME MORE STOCK IN THE HRRR IDEA...AS SHORTWAVE THAT HAS
GENERATED CLUSTER OF THUNDERSTORMS NOW OVER NW IA WILL BE TRACKING
ACROSS MN...AND ALONG THE DEWP GRADIENT THIS AFTERNOON PER THE RAP
AND 12Z NAM.
COUPLE OF LIMITING FACTORS FOR STORMS THOUGH IS THAT THE 12Z MPX
SOUNDING SHOWED QUITE A BIT OF DRY AIR ABOVE 750 MB /POSSIBLE
ENTRAINMENT ISSUES/...THE SAME SOUNDING ALSO SHOWED WEAK LAPSE
RATES FROM THE SFC TO 700 MB /IS THE RAP TOO AGGRESSIVE WITH
ANALYZED INSTABILITY?/...AND CONVECTION OVER NW IA HAS DEPOSITED A
DENSE CIRRUS SHIELD OVER MN...LIMITING AMOUNT OF SOLAR INSOLATION
AND POSSIBLE DESTABILIZATION.
AS FOR SEVERE THREAT...THAT IS LOOKING SMALL NOW THAT COMPLEX OVER
NW IOWA THAT BROUGHT SOME 60 MPH WINDS TO THE YANKTON AREA LOOKS
TO BE FOLLOWING THE 850-300MB THICKNESS LINES EAST ACROSS IOWA.
H85 WINDS THROUGH THE DAY WILL REMAIN WEAK UP HERE IN THE MPX
AREA...AND MASS FIELDS JUST DO NOT SEEM TO BE THERE FOR SEVERE
WEATHER. WITH THAT SAID...IF WE DO SEE STORMS INITIATE...EXPECT
THEM TO BE OF THE SCT-BKN VARIETY WITH A COUPLE OF STORMS POSSIBLY
PULSING UP ENOUGH FOR A BRIEF HAIL/WIND THREAT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 420 AM CDT SAT JUN 15 2013
WIDELY SCATTERED CONVECTIVE ACTIVITY STILL NOTED AT 0.5 REFLECTIVITY
AT THIS HOUR OVER FAR EASTERN PORTIONS OF WEST CENTRAL WI. LARGE
MCS WHICH FORMED DURING THE EVENING HOURS FROM FAR SOUTHERN MN
INTO IOWA AND NORTHERN MO CONTINUES TO SLOWLY MARCH EASTWARD INTO
THE WESTERN GREAT LAKES REGION. HAVE DROPPED THE FLOOD WATCH FOR
FARIBAULT AND FREEBORN COUNTIES DUE TO LACK OF ANY APPRECIABLE
QPF ANTICIPATED TODAY ASSOCIATED WITH APPROACHING COLD FRONT.
IN ADDITION SATURATED SOIL PRESENT AFTER WEDNESDAY`S HEAVY RAIN
HAS HAD OVER 48 HOURS OF DRYING/LIMITED NEW RAINFALL EXPOSURE.
INTRODUCED SLIGHT CHANCE OF POPS TO MUCH OF CWA DURING THE AFTERNOON
ASSOCIATED WITH FRONTAL PASSAGE NOTED ABOVE. HRRR PAINTING A FAIRLY
WIDESPREAD AREA OF LIGHT SHOWERS...WITH A FEW THUNDERSTORMS FROM
SOUTH CENTRAL MN TO EAST CENTRAL MN THROUGH WEST CENTRAL WI BY
19Z. ALTHOUGH VERY HEALTHY DIVERGENCE ALOFT WILL BE PRESENT AT THIS
TIME...BELIEVE HRRR IS OVER DOING INTENSITY OF CONVECTIVE ACTIVITY.
DRYING BEHIND THE FRONT WILL ELIMINATE MOST RAINFALL AND ASSOCIATED
CLOUD DECK BY 02Z OVER FA. A NICE COOL CRISP NIGHT ANTICIPATED
TONIGHT WITH MOSTLY CLEAR SKIES AND READING DIPPING INTO THE MID
TO UPPER 50S MOST LOCALES.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 420 AM CDT SAT JUN 15 2013
SUNDAY SHOULD BE A WARM AND PRIMARILY DRY DAY...AS WESTERLY FLOW
DOMINATES IN ADVANCE OF AN ELONGATED TROUGH OVER
MANITOBA/SASKATCHEWAN/ONTARIO. MODELS HAVE EXHIBITED DECENT
CONTINUITY WITH THIS FEATURE...WHICH IS FORECAST TO DROP ACROSS
MN/WI LATE SUNDAY INTO MONDAY. ASSOCIATED MOISTURE/LIFT SHOULD BE
SUFFICIENT TO GENERATE SCATTERED SHOWERS AND THUNDERSTORMS BY 00Z
MONDAY ACROSS WEST CENTRAL MN...AND OVER THE REMAINDER OF THE
FORECAST AREA ON SUNDAY NIGHT INTO MONDAY MORNING. QPF AMOUNTS
SHOULD BE RATHER LIGHT...GENERALLY IN THE ONE TO TWO TENTHS OF AN
INCH RANGE.
TUESDAY AND WEDNESDAY FEATURE RISING MID LEVEL HEIGHTS AS THE
WESTERN RIDGE BUILDS INTO THE CENTRAL UNITED STATES. SEASONAL TEMPERATURES
IN THE MID 70S TO LOWER 80S SHOULD PREVAIL...ALONG WITH DRY
WEATHER.
AN EVEN WARMER DAY IS EXPECTED FOR THURSDAY...AS THE THERMAL RIDGE
AHEAD OF AN APPROACHING TROUGH BUILDS INTO THE AREA. SHOWERS AND
THUNDERSTORM CHANCES RE-ENTER THE FORECAST ON THURSDAY AND FRIDAY
AS LLVL MOISTURE TRANSPORT/ADVECTION NOSE INTO THE AREA. HAVE
INCLUDED 30-40 POPS AT THIS POINT...WITH HIGHER CONFIDENCE IN MORE
ORGANIZED CONVECTION NEXT FRIDAY NIGHT AND SATURDAY AS THE SURFACE
TROUGH AND ASSOCIATED BOUNDARIES PASS ACROSS IN CONJUNCTION WITH
MID LEVEL SHORTWAVE ENERGY. THIS IS ALSO THE TIME FRAME WHEN THE
JET STRUCTURE SHOULD BE SUPPLYING DECENT DIFFERENTIAL DIVERGENCE.
HAVE INCLUDED 50-60 POPS FROM 00Z SATURDAY TO 00Z SUNDAY...GIVEN
DECENT AGREEMENT BETWEEN THE 15.00Z ECMWF AND GFS SOLUTIONS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 101 PM CDT SAT JUN 15 2013
STRONG SHORTWAVE NOW MOVING INTO THE FAIRMONT AREA...WITH
THUNDERSTORM COVERAGE STARTING TO INCREASE AS LIFT FROM THIS WAVE
BEGINS TO INTERACT WITH INSTABILITY PRESENT OVER THE REGION. PER
THE RAP...EXPECT THE UPPER WAVE TO TRACK TO RST OVER TO SOUTH OF
EAU. MOST WIDESPREAD TSRA COVERAGE IS EXPECTED TO REMAIN JUST
SOUTH OF THE FIELDS...THOUGH SCT-BKN SHRA/TSRA STILL EXPECTED FROM
MSP EAST...AS SHOWN IN THE 15Z RUN OF THE HRRR. DEWPOINT BOUNDARY
NEAR RWF/STC AT 18Z...AND LOW TEMP/DEWP SPREADS TO THE EAST OF THE
BOUNDARY WILL CONTINUE THE THREAT FOR MVFR CIGS FROM ERN MN INTO
WRN WI. STILL EXPECT THIS ACTIVITY TO BE EAST OF THE MPX TERMINALS
BY 00Z...WITH VFR CONDITIONS EXPECTED THROUGH THE REST OF THE
NIGHT. SUNDAY...NAM FORECAST SOUNDINGS SHOWING DEEP MIXING BY THE
AFTERNOON...WITH GUSTS OF 20-25KTS EXPECTED AS A RESULT BY THE END
OF THE TAFS.
KMSP...STORMS FINALLY BEGINNING TO DEVELOP AS ERN MN STARTS
GETTING UNDER THE INFLUENCE OF THE SHORT WAVE DOWN TOWARD MKT.
WILL HAVE THUNDER IN THE AREA THRU ABOUT 22Z BEFORE CONDITIONS
RAPIDLY DRY OUT THE REST OF THE NIGHT. FOR SUNDAY AFTERNOON COULD
SEE AN ISOLATED THUNDERSTORM DEVELOP AROUND 00Z...BUT BETTER
MOISTURE LOOKS TO BE UP IN NRN MN FOR SOME ISO THUNDER BEFORE 00Z.
/OUTLOOK FOR KMSP/
MON...CHANCE OF MVFR CONDS AND TSRA MAINLY IN MORNING. NW WINDS 10KTS.
TUE...VFR. LGT AND VRB WINDS.
WED...VFR. S WINDS 5 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
UPDATE...MPG
SHORT TERM...AJZ
LONG TERM...LS
AVIATION...MPG
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1056 AM CDT SAT JUN 15 2013
.UPDATE...
RATHER COMPLEX FORECAST SCENARIO FOR THE FIRST 12 HOURS THIS
MORNING WITH SOMEWHAT LOW CONFIDENCE ON EXACT PLACEMENT OF
REDEVELOPMENT OF SHOWERS/TSTORMS TODAY/TONIGHT. DEEP LAYER CYCLONE
HAS CLOSED OFF OVER SASKATCHEWAN THIS MORNING..WITH DRY SLOT/PV
LOBE CLEARLY EVIDENT IN WV IMAGERY WRAPPING AROUND THE SOUTHEAST
PERIPHERY OF THE CIRCULATION. THE INITIAL ROUND OF SHOWERS/TSTORMS
OVERNIGHT ASSOCIATED WITH WARM/MOIST ADVECTION HAS MOVED EAST OF
THE AREA..BUT WITH THE MAIN PUSH ON THE DRY SLOT BECOMING MORE
NORTHEASTERLY THIS MORNING..THE EASTWARD PROGRESS OF THE LOW
LEVEL FRONTAL ZONE AND INSTABILITY AXIS HAS SLOWED OR EVEN STALLED
ACROSS THE DLH CWA AS A SECONDARY WAVE ROTATES EASTWARD ACROSS THE
DAKOTAS.
AN AXIS OF SHOWERS HAS BEEN EVIDENT ALL MORNING FROM NRN SD INTO
WRN MN. THESE SHOWERS ARE HIGH BASED..AND HAVE BEEN LOCATED ALONG
THE LEADING EDGE OF THE MID LEVEL PV LOBE..AND ALSO APPEAR TO BE
GETTING SOME ASSISTANCE IN MAINTENANCE FROM MID LEVEL FGEN. OVER
THE PAST HOUR..THERE HAS BEEN SOME INCREASE IN COVERAGE JUST TO
THE SW OF THE BRAINERD AREA..AS A FLUX OF MOISTURE MOVES NORTHWARD
INTO THIS UVM FORCING ZONE FROM THE NORTHERN EXTENT OF THE
STRATIFORM RAIN AREA OF LARGE MCS IN THE SIOUX FALLS AREA. MAIN
UNCERTAINTY FOR THE REST OF THE DAY REVOLVES AROUND TWO FACTORS 1)
HOW FAR NORTH/EAST WILL THE EXISTING SHOWERS PERSIST..AND 2) WILL
THERE BE ADDITIONAL REDEVELOPMENT OVER NRN MN WHERE STRONGER FLOW
AND SUN WILL RESULT IN DEEP MIXING ALONG NORTHERN END OF
INSTABILITY AXIS.
THERE IS FAIRLY WIDESPREAD DIFFERENCE IN THE SHORT RANGE
GUIDANCE..WITH SOME MODELS WANTING TO DRY THINGS OUT COMPLETELY
ACROSS THE NORTH..WHILE OTHERS DEVELOP QPF. SIMILAR SPREAD IN
SOLUTIONS OVER THE SOUTH WHERE THE HRRR IN PARTICULAR WANTS TO
SPREAD RAIN ACROSS MUCH OF THE SOUTHERN CWA BY MID AFTERNOON
EVOLVING OUT OF THE ONGOING MCS OVER SRN MN/NRN IA. IF ANYTHING
WERE TO DEVELOP ACROSS THE NORTH..DEEP LAYER SHEAR AND STEEP LAPSE
RATES SUGGEST AT LEAST A MARGINAL HAIL/WIND THREAT AND SOME
ORGANIZATION FOR THE STRONGEST STORMS.
FOR NOW..WE HAVE EXPANDED POPS OVER MOST OF THE CWA FOR THIS
AFTERNOON TO AT LEAST MAINTAIN A MENTION OF ADDITIONAL
REDEVELOPMENT. BUT..WITH THE EXCEPTION OF PARTS OF NW WI..WE HAVE
KEPT THEM 15-25 PERCENT FOR NOW. LOOKING AT CURRENT RADAR TRENDS
HOWEVER..WE MAY NEED TO ADJUST UPWARD EVEN MORE ACROSS WRN/SW
PARTS OF THE CWA. ALSO MADE SOME MINOR TWEAKS TO TEMPS/SKY COVER
AND WINDS TO ACCOUNT FOR HIGHER CLOUD COVERAGE AND SLOWER CLEARING
TREND IN ALL LOCATIONS EXCEPT FOR THE FAR NW PART OF THE CWA. ALSO
HELD ON TO EASTERLY WIND COMPONENT OVER LK SUPERIOR UNTIL LATE
AFTERNOON WHEN PRESSURE RISE CENTER FINALLY IS FORECAST TO MOVE
EAST OF THE TWIN PORTS. UNTIL THEN..EAST WINDS AND TEMPS IN THE
40S ARE LIKELY TO HOLD FIRM IN AREAS IMMEDIATELY ADJACENT TO THE
LAKE. UPDATES ARE ALREADY AVAILABLE.
&&
.PREV DISCUSSION... /ISSUED 631 AM CDT SAT JUN 15 2013/
AVIATION...12Z TAFS
SCATTERED SHOWERS AND A FEW THUNDERSTORMS CONTINUED OVER THE
ARROWHEAD SOUTH OVER PORTIONS OF NORTHWEST WISCONSIN EARLY THIS
MORNING. MUCH OF THIS ACTIVITY WILL MOVE OFF TO THE EAST OVER THE
NEXT 2-3 HOURS. THERE WERE SOME PATCHY MVFR CEILINGS OUT
THERE...AND THEY MAY IMPACT THE TAF SITES THROUGH 15Z.
ANOTHER AREAS OF LIGHT SHOWERS WERE OCCURRING IN AN AREA OF MID
LEVEL FGEN. THE RAP WAS DOING AN DECENT JOB DEPICTING THESE
SHOWERS...AND THEY MAY IMPACT KBRD/KHIB/KDLH EARLY TO MID
AFTERNOON...AND KHYR LATER THIS AFTERNOON/EVENING. AT THIS
TIME...WE DID NOT ADD A MENTION AS COVERAGE SHOULD BE LIMITED.
WE MAY NEED TO UPDATE THE TAF ONCE CERTAINTY INCREASES ON WHEN THE
SHOWERS WILL MOVE IN.
PREV DISCUSSION... /ISSUED 354 AM CDT SAT JUN 15 2013/
CURRENT...WARM ADVECTION REGIME CONTINUES ACROSS THE CWA AHEAD
OF APPROACHING FRONTAL BDRY. AN AREA OF CONVECTION STRETCHES FROM
THE ARROWHEAD TO NORTHWEST WISCONSIN AS OF MID MORNING. THIS
APPEARS TO BE ASSOCIATED WITH THE 70H THETAE RIDGE. A FEW STORMS
HAVE PUSHED THEIR 50DBZ CORES TO 30/33K FT OVER CENTRAL ST LOUIS
COUNTY BUT ONLY PEA SIZED HAIL REPORTED AT THIS TIME. INITIAL BAND
OF CONVECTION HAS OUTRUN BEST THERMODYNAMICS WITH A FEW CELLS
REDEVELOPING OVER WRN CWA CLOSER TO ACTUAL FRONTAL BDRY. TEMPS RANGE
FROM MID 60S OVER SRN TIER OF CWA TO 40S NEAR LAKE SUPERIOR.
TODAY...FRNTL BDRY WILL MOVE RATHER SLOWLY EAST ACROSS THE CWA
TODAY. LINGERING RW/TRW ARE POSSIBLE FROM ARROWHEAD INTO NWRN
WISCONSIN. INSTABILITY/DEEP LAYER SHEAR VALUES STILL SUPPORTIVE OF
POTENTIAL FOR A FEW STRONG STORMS. MAX TEMPS WILL RISE TO ABOVE
CLIMO VALUES. HI RES DLHWRF SHOWS A PUSH OF WARMER OFFSHORE FLOW
LATE TODAY AFTER COOLER ONSHORE FLOW INITIALLY.
TONIGHT/TOMORROW...FRNTL BDRY PUSHES FARTHER SOUTH AND EAST OF
CWA TONIGHT AS DEEP LAYER DRYING INCREASES TEMPORARILY. AN
ELONGATED MID LVL TROF NORTH OF THE BORDER WILL MOVE SOUTH
TOMORROW. A SFC COLD FRONT WILL ACT IN CONJUNCTION WITH AN
INCREASE IN MOISTURE AND INCREASE THE LIKELIHOOD OF RW/TRW SUNDAY
ACROSS MOST OF THE MN ZONES. MDLS DIFFER ON HOW FAR SOUTH
SUFFICIENT MOISTURE PUSHES. HAVE OPTED FOR THE CONSENSUS BETWEEN
THE MORE AGGRESSIVE NAM AND THE MORE NRN SOLUTION PROVIDED BY THE
ECMWF. MAX TEMPS SHOULD CLIMB INTO LOW 80S ACROSS SRN CWA WITH MID
70S ELSEWHERE.
EXTENDED...SUNDAY NIGHT THROUGH FRIDAY.
A SHORTWAVE AND INVERTED SURFACE TROUGH WILL KEEP SHOWERS AND
THUNDERSTORMS IN THE FORECAST SUNDAY NIGHT INTO MONDAY...ALTHOUGH
PROBABILITIES WILL BE DIMINISHING ON MONDAY AS HIGH PRESSURE STARTS
TO MOVE INTO THE NORTHLAND.
HIGH PRESSURE SHOULD PROVIDE DRY WEATHER MONDAY NIGHT INTO TUESDAY.
A RIDGE ALOFT WILL EXTEND NORTH THROUGH THE NORTHERN PLAINS TUESDAY
NIGHT WITH IT MOVING EAST AND FLATTENING BY FRIDAY. THE GFS SHOWS A
SHORTWAVE MOVING THROUGH THE RIDGE PROVIDING A CHANCE FOR
SHOWERS/STORMS OVER NORTHERN MINNESOTA...WITH THE ECMWF DRY. WE
FOLLOWED CLOSER TO THE GFS AT THIS TIME. WE HAVE LOW POPS INTO
FRIDAY FOR SOME SHOWERS/STORMS...BUT CONFIDENCE IS LOW FROM TUESDAY
NIGHT THROUGH FRIDAY ON RAIN CHANCES.
TEMPERATURES WILL GRADUALLY WARM THROUGH THE PERIOD...STARTING OUT
IN THE UPPER SIXTIES TO LOWER SEVENTIES MONDAY...AND WARMING TO 75
TO 80 BY THURSDAY.
AVIATION...06Z TAF ISSUANCE. MID LEVEL CEILINGS WILL PREVAIL
THROUGH NIGHT WITH SCT SHOWERS/STORMS AND POSSIBLE BRIEF MVFR
CIGS. THE EXCEPTION WILL BE AT KBRD WHERE THE THUNDER THREAT IS
MINIMAL. WINDS WILL TURN OUT OF THE SOUTHWEST THEN WEST...SATURDAY
MORNING...WITH GRADUALLY CLEARING SKIES FROM THE WEST THROUGH THE
DAY SAT.
&&
.POINT TEMPS/POPS...
DLH 72 54 78 53 / 20 20 20 50
INL 77 50 77 49 / 20 20 40 40
BRD 77 55 80 57 / 20 10 10 30
HYR 77 54 81 55 / 20 20 10 50
ASX 72 52 77 52 / 30 20 20 50
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...MILLER
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1036 AM CDT SAT JUN 15 2013
.UPDATE...
ISSUED AT 1035 AM CDT SAT JUN 15 2013
MADE SOME CHANGES TO THE POPS THIS MORNING TO INCREASE THEM
CONSIDERABLY TROUGH THE AFTERNOON FROM SOUTH CENTRAL MN INTO ERN
MN AND WESTERN WI. THIS WAS BASED QUITE HEAVILY ON THE HRRR /WHICH
HAS BEEN VERY CONSISTENT THROUGH THE MORNING/ AND THE 15.00 RUN OF
THE MPXWRF.
FRONT IS JUST NOW PUSHING THROUGH THE I-35 CORRIDOR IN TERMS OF A
WIND SHIFT...BUT DEWPOINT DROP IS TRAILING THE WIND SHIFT BY A
GOOD 75+ MILES TO THE WEST. MESO ANALYSIS PAGE SHOWING 500-1500
J/KG OF MLCAPE AT 15Z OUT AHEAD OF THE BOUNDARY...WITH CIN
BEGINNING TO DECREASE. THIS INSTABILITY/WEAK STABILITY AHEAD OF
THE DEWP DROP IS LIKELY WHY THE HRRR CONTINUES TO SHOW DEEP
CONVECTION INITIATING WEST OF THE TWIN CITIES BETWEEN 16Z AND 17Z.
DO PUT SOME MORE STOCK IN THE HRRR IDEA...AS SHORTWAVE THAT HAS
GENERATED CLUSTER OF THUNDERSTORMS NOW OVER NW IA WILL BE TRACKING
ACROSS MN...AND ALONG THE DEWP GRADIENT THIS AFTERNOON PER THE RAP
AND 12Z NAM.
COUPLE OF LIMITING FACTORS FOR STORMS THOUGH IS THAT THE 12Z MPX
SOUNDING SHOWED QUITE A BIT OF DRY AIR ABOVE 750 MB /POSSIBLE
ENTRAINMENT ISSUES/...THE SAME SOUNDING ALSO SHOWED WEAK LAPSE
RATES FROM THE SFC TO 700 MB /IS THE RAP TOO AGGRESSIVE WITH
ANALYZED INSTABILITY?/...AND CONVECTION OVER NW IA HAS DEPOSITED A
DENSE CIRRUS SHIELD OVER MN...LIMITING AMOUNT OF SOLAR INSOLATION
AND POSSIBLE DESTABILIZATION.
AS FOR SEVERE THREAT...THAT IS LOOKING SMALL NOW THAT COMPLEX OVER
NW IOWA THAT BROUGHT SOME 60 MPH WINDS TO THE YANKTON AREA LOOKS
TO BE FOLLOWING THE 850-300MB THICKNESS LINES EAST ACROSS IOWA.
H85 WINDS THROUGH THE DAY WILL REMAIN WEAK UP HERE IN THE MPX
AREA...AND MASS FIELDS JUST DO NOT SEEM TO BE THERE FOR SEVERE
WEATHER. WITH THAT SAID...IF WE DO SEE STORMS INITIATE...EXPECT
THEM TO BE OF THE SCT-BKN VARIETY WITH A COUPLE OF STORMS POSSIBLY
PULSING UP ENOUGH FOR A BRIEF HAIL/WIND THREAT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 420 AM CDT SAT JUN 15 2013
WIDELY SCATTERED CONVECTIVE ACTIVITY STILL NOTED AT 0.5 REFLECTIVITY
AT THIS HOUR OVER FAR EASTERN PORTIONS OF WEST CENTRAL WI. LARGE
MCS WHICH FORMED DURING THE EVENING HOURS FROM FAR SOUTHERN MN
INTO IOWA AND NORTHERN MO CONTINUES TO SLOWLY MARCH EASTWARD INTO
THE WESTERN GREAT LAKES REGION. HAVE DROPPED THE FLOOD WATCH FOR
FARIBAULT AND FREEBORN COUNTIES DUE TO LACK OF ANY APPRECIABLE
QPF ANTICIPATED TODAY ASSOCIATED WITH APPROACHING COLD FRONT.
IN ADDITION SATURATED SOIL PRESENT AFTER WEDNESDAY`S HEAVY RAIN
HAS HAD OVER 48 HOURS OF DRYING/LIMITED NEW RAINFALL EXPOSURE.
INTRODUCED SLIGHT CHANCE OF POPS TO MUCH OF CWA DURING THE AFTERNOON
ASSOCIATED WITH FRONTAL PASSAGE NOTED ABOVE. HRRR PAINTING A FAIRLY
WIDESPREAD AREA OF LIGHT SHOWERS...WITH A FEW THUNDERSTORMS FROM
SOUTH CENTRAL MN TO EAST CENTRAL MN THROUGH WEST CENTRAL WI BY
19Z. ALTHOUGH VERY HEALTHY DIVERGENCE ALOFT WILL BE PRESENT AT THIS
TIME...BELIEVE HRRR IS OVER DOING INTENSITY OF CONVECTIVE ACTIVITY.
DRYING BEHIND THE FRONT WILL ELIMINATE MOST RAINFALL AND ASSOCIATED
CLOUD DECK BY 02Z OVER FA. A NICE COOL CRISP NIGHT ANTICIPATED
TONIGHT WITH MOSTLY CLEAR SKIES AND READING DIPPING INTO THE MID
TO UPPER 50S MOST LOCALES.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 420 AM CDT SAT JUN 15 2013
SUNDAY SHOULD BE A WARM AND PRIMARILY DRY DAY...AS WESTERLY FLOW
DOMINATES IN ADVANCE OF AN ELONGATED TROUGH OVER
MANITOBA/SASKATCHEWAN/ONTARIO. MODELS HAVE EXHIBITED DECENT
CONTINUITY WITH THIS FEATURE...WHICH IS FORECAST TO DROP ACROSS
MN/WI LATE SUNDAY INTO MONDAY. ASSOCIATED MOISTURE/LIFT SHOULD BE
SUFFICIENT TO GENERATE SCATTERED SHOWERS AND THUNDERSTORMS BY 00Z
MONDAY ACROSS WEST CENTRAL MN...AND OVER THE REMAINDER OF THE
FORECAST AREA ON SUNDAY NIGHT INTO MONDAY MORNING. QPF AMOUNTS
SHOULD BE RATHER LIGHT...GENERALLY IN THE ONE TO TWO TENTHS OF AN
INCH RANGE.
TUESDAY AND WEDNESDAY FEATURE RISING MID LEVEL HEIGHTS AS THE
WESTERN RIDGE BUILDS INTO THE CENTRAL UNITED STATES. SEASONAL TEMPERATURES
IN THE MID 70S TO LOWER 80S SHOULD PREVAIL...ALONG WITH DRY
WEATHER.
AN EVEN WARMER DAY IS EXPECTED FOR THURSDAY...AS THE THERMAL RIDGE
AHEAD OF AN APPROACHING TROUGH BUILDS INTO THE AREA. SHOWERS AND
THUNDERSTORM CHANCES RE-ENTER THE FORECAST ON THURSDAY AND FRIDAY
AS LLVL MOISTURE TRANSPORT/ADVECTION NOSE INTO THE AREA. HAVE
INCLUDED 30-40 POPS AT THIS POINT...WITH HIGHER CONFIDENCE IN MORE
ORGANIZED CONVECTION NEXT FRIDAY NIGHT AND SATURDAY AS THE SURFACE
TROUGH AND ASSOCIATED BOUNDARIES PASS ACROSS IN CONJUNCTION WITH
MID LEVEL SHORTWAVE ENERGY. THIS IS ALSO THE TIME FRAME WHEN THE
JET STRUCTURE SHOULD BE SUPPLYING DECENT DIFFERENTIAL DIVERGENCE.
HAVE INCLUDED 50-60 POPS FROM 00Z SATURDAY TO 00Z SUNDAY...GIVEN
DECENT AGREEMENT BETWEEN THE 15.00Z ECMWF AND GFS SOLUTIONS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 720 AM CDT SAT JUN 15 2013
WEAK SURFACE COLD FRONT TO PASS ACROSS THE TAF AREA TODAY. WHILE
PROGGED FORCING IS SHORT OF IMPRESSIVE AND MOISTURE IS SOMEWHAT LACKING...TRENDS
IN SEVERAL OF THE SHORT TERM MODELS...NAMELY THE HRRR AND HI-RES
ARW- WEST...WHICH PERFORMED FAIRLY WELL OVER THE LAST 12
HOURS...INDICATE DIURNAL CONVECTIVE DEVELOPMENT COULD OCCUR AS FAR
NORTH AND WEST AS KRWF-KMSP AROUND 18-19Z. HAVE INCLUDED VCTS WITH
A TEMPO FOR SHRA AT EASTERN SITES /KMSP-KRNH-KEAU/ THIS
AFTERNOON...ALTHOUGH RESTRICTIONS SHOULD MOSTLY BE LOW-END VFR TO
HIGH-END MVFR. CLOUDS SCATTER THIS EVENING AND OVERNIGHT. WINDS
WILL SHIFT TO THE WEST/NORTHWEST THROUGHOUT THE DAY WITH THE
PASSING OF THE FRONT...ALTHOUGH POST-FRONTAL SPEEDS ARE NOT
EXPECTED TO INCREASE TO MORE THAN ABOUT 12 KTS.
KMSP...
WINDOW FOR POTENTIAL SHRA/TS APPEARS TO LIE BETWEEN 18Z AND
23Z...ALTHOUGH CONFIDENCE IS NOT HIGH. CIGS ARE EXPECTED TO STAY
VFR WITH MVFR VSBYS POSSIBLE IN ANY SHRA/TS. WINDS SHIFT TO THE
SOUTHWEST BY 15Z...THEN NORTHWESTERLY BY 17Z. SPEEDS AOB 10 KTS.
/OUTLOOK FOR KMSP/
MON...CHANCE OF MVFR CONDS AND TSRA. NW WINDS 10KTS.
TUE...VFR. LGT AND VRB WINDS.
WED...VFR. S WINDS 5 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
UPDATE...MPG
SHORT TERM...AJZ
LONG TERM...LS
AVIATION...LS
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
720 AM CDT SAT JUN 15 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 420 AM CDT SAT JUN 15 2013
WIDELY SCATTERED CONVECTIVE ACTIVITY STILL NOTED AT 0.5 REFLECTIVITY
AT THIS HOUR OVER FAR EASTERN PORTIONS OF WEST CENTRAL WI. LARGE
MCS WHICH FORMED DURING THE EVENING HOURS FROM FAR SOUTHERN MN
INTO IOWA AND NORTHERN MO CONTINUES TO SLOWLY MARCH EASTWARD INTO
THE WESTERN GREAT LAKES REGION. HAVE DROPPED THE FLOOD WATCH FOR
FARIBAULT AND FREEBORN COUNTIES DUE TO LACK OF ANY APPRECIABLE
QPF ANTICIPATED TODAY ASSOCIATED WITH APPROACHING COLD FRONT.
IN ADDITION SATURATED SOIL PRESENT AFTER WEDNESDAY`S HEAVY RAIN
HAS HAD OVER 48 HOURS OF DRYING/LIMITED NEW RAINFALL EXPOSURE.
INTRODUCED SLIGHT CHANCE OF POPS TO MUCH OF CWA DURING THE AFTERNOON
ASSOCIATED WITH FRONTAL PASSAGE NOTED ABOVE. HRRR PAINTING A FAIRLY
WIDESPREAD AREA OF LIGHT SHOWERS...WITH A FEW THUNDERSTORMS FROM
SOUTH CENTRAL MN TO EAST CENTRAL MN THROUGH WEST CENTRAL WI BY
19Z. ALTHOUGH VERY HEALTHY DIVERGENCE ALOFT WILL BE PRESENT AT THIS
TIME...BELIEVE HRRR IS OVER DOING INTENSITY OF CONVECTIVE ACTIVITY.
DRYING BEHIND THE FRONT WILL ELIMINATE MOST RAINFALL AND ASSOCIATED
CLOUD DECK BY 02Z OVER FA. A NICE COOL CRISP NIGHT ANTICIPATED
TONIGHT WITH MOSTLY CLEAR SKIES AND READING DIPPING INTO THE MID
TO UPPER 50S MOST LOCALES.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 420 AM CDT SAT JUN 15 2013
SUNDAY SHOULD BE A WARM AND PRIMARILY DRY DAY...AS WESTERLY FLOW
DOMINATES IN ADVANCE OF AN ELONGATED TROUGH OVER
MANITOBA/SASKATCHEWAN/ONTARIO. MODELS HAVE EXHIBITED DECENT
CONTINUITY WITH THIS FEATURE...WHICH IS FORECAST TO DROP ACROSS
MN/WI LATE SUNDAY INTO MONDAY. ASSOCIATED MOISTURE/LIFT SHOULD BE
SUFFICIENT TO GENERATE SCATTERED SHOWERS AND THUNDERSTORMS BY 00Z
MONDAY ACROSS WEST CENTRAL MN...AND OVER THE REMAINDER OF THE
FORECAST AREA ON SUNDAY NIGHT INTO MONDAY MORNING. QPF AMOUNTS
SHOULD BE RATHER LIGHT...GENERALLY IN THE ONE TO TWO TENTHS OF AN
INCH RANGE.
TUESDAY AND WEDNESDAY FEATURE RISING MID LEVEL HEIGHTS AS THE
WESTERN RIDGE BUILDS INTO THE CENTRAL UNITED STATES. SEASONAL TEMPERATURES
IN THE MID 70S TO LOWER 80S SHOULD PREVAIL...ALONG WITH DRY
WEATHER.
AN EVEN WARMER DAY IS EXPECTED FOR THURSDAY...AS THE THERMAL RIDGE
AHEAD OF AN APPROACHING TROUGH BUILDS INTO THE AREA. SHOWERS AND
THUNDERSTORM CHANCES RE-ENTER THE FORECAST ON THURSDAY AND FRIDAY
AS LLVL MOISTURE TRANSPORT/ADVECTION NOSE INTO THE AREA. HAVE
INCLUDED 30-40 POPS AT THIS POINT...WITH HIGHER CONFIDENCE IN MORE
ORGANIZED CONVECTION NEXT FRIDAY NIGHT AND SATURDAY AS THE SURFACE
TROUGH AND ASSOCIATED BOUNDARIES PASS ACROSS IN CONJUNCTION WITH
MID LEVEL SHORTWAVE ENERGY. THIS IS ALSO THE TIME FRAME WHEN THE
JET STRUCTURE SHOULD BE SUPPLYING DECENT DIFFERENTIAL DIVERGENCE.
HAVE INCLUDED 50-60 POPS FROM 00Z SATURDAY TO 00Z SUNDAY...GIVEN
DECENT AGREEMENT BETWEEN THE 15.00Z ECMWF AND GFS SOLUTIONS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 720 AM CDT SAT JUN 15 2013
WEAK SURFACE COLD FRONT TO PASS ACROSS THE TAF AREA TODAY. WHILE
PROGGED FORCING IS SHORT OF IMPRESSIVE AND MOISTURE IS SOMEWHAT LACKING...TRENDS
IN SEVERAL OF THE SHORT TERM MODELS...NAMELY THE HRRR AND HI-RES
ARW- WEST...WHICH PERFORMED FAIRLY WELL OVER THE LAST 12
HOURS...INDICATE DIURNAL CONVECTIVE DEVELOPMENT COULD OCCUR AS FAR
NORTH AND WEST AS KRWF-KMSP AROUND 18-19Z. HAVE INCLUDED VCTS WITH
A TEMPO FOR SHRA AT EASTERN SITES /KMSP-KRNH-KEAU/ THIS
AFTERNOON...ALTHOUGH RESTRICTIONS SHOULD MOSTLY BE LOW-END VFR TO
HIGH-END MVFR. CLOUDS SCATTER THIS EVENING AND OVERNIGHT. WINDS
WILL SHIFT TO THE WEST/NORTHWEST THROUGHOUT THE DAY WITH THE
PASSING OF THE FRONT...ALTHOUGH POST-FRONTAL SPEEDS ARE NOT
EXPECTED TO INCREASE TO MORE THAN ABOUT 12 KTS.
KMSP...
WINDOW FOR POTENTIAL SHRA/TS APPEARS TO LIE BETWEEN 18Z AND
23Z...ALTHOUGH CONFIDENCE IS NOT HIGH. CIGS ARE EXPECTED TO STAY
VFR WITH MVFR VSBYS POSSIBLE IN ANY SHRA/TS. WINDS SHIFT TO THE
SOUTHWEST BY 15Z...THEN NORTHWESTERLY BY 17Z. SPEEDS AOB 10 KTS.
/OUTLOOK FOR KMSP/
MON...CHANCE OF MVFR CONDS AND TSRA. NW WINDS 10KTS.
TUE...VFR. LGT AND VRB WINDS.
WED...VFR. S WINDS 5 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...AJZ
LONG TERM...LS
AVIATION...LS
AREA FORECAST DISCUSSION
NWS DULUTH MN
631 AM CDT SAT JUN 15 2013
.AVIATION...12Z TAFS
SCATTERED SHOWERS AND A FEW THUNDERSTORMS CONTINUED OVER THE
ARROWHEAD SOUTH OVER PORTIONS OF NORTHWEST WISCONSIN EARLY THIS
MORNING. MUCH OF THIS ACTIVITY WILL MOVE OFF TO THE EAST OVER THE
NEXT 2-3 HOURS. THERE WERE SOME PATCHY MVFR CEILINGS OUT
THERE...AND THEY MAY IMPACT THE TAF SITES THROUGH 15Z.
ANOTHER AREAS OF LIGHT SHOWERS WERE OCCURRING IN AN AREA OF MID
LEVEL FGEN. THE RAP WAS DOING AN DECENT JOB DEPICTING THESE
SHOWERS...AND THEY MAY IMPACT KBRD/KHIB/KDLH EARLY TO MID
AFTERNOON...AND KHYR LATER THIS AFTERNOON/EVENING. AT THIS
TIME...WE DID NOT ADD A MENTION AS COVERAGE SHOULD BE LIMITED.
WE MAY NEED TO UPDATE THE TAF ONCE CERTAINTY INCREASES ON WHEN THE
SHOWERS WILL MOVE IN.
&&
.PREV DISCUSSION... /ISSUED 354 AM CDT SAT JUN 15 2013/
CURRENT...WARM ADVECTION REGIME CONTINUES ACROSS THE CWA AHEAD
OF APPROACHING FRONTAL BDRY. AN AREA OF CONVECTION STRETCHES FROM
THE ARROWHEAD TO NORTHWEST WISCONSIN AS OF MID MORNING. THIS
APPEARS TO BE ASSOCIATED WITH THE 70H THETAE RIDGE. A FEW STORMS
HAVE PUSHED THEIR 50DBZ CORES TO 30/33K FT OVER CENTRAL ST LOUIS
COUNTY BUT ONLY PEA SIZED HAIL REPORTED AT THIS TIME. INITIAL BAND
OF CONVECTION HAS OUTRUN BEST THERMODYNAMICS WITH A FEW CELLS
REDEVELOPING OVER WRN CWA CLOSER TO ACTUAL FRONTAL BDRY. TEMPS RANGE
FROM MID 60S OVER SRN TIER OF CWA TO 40S NEAR LAKE SUPERIOR.
TODAY...FRNTL BDRY WILL MOVE RATHER SLOWLY EAST ACROSS THE CWA
TODAY. LINGERING RW/TRW ARE POSSIBLE FROM ARROWHEAD INTO NWRN
WISCONSIN. INSTABILITY/DEEP LAYER SHEAR VALUES STILL SUPPORTIVE OF
POTENTIAL FOR A FEW STRONG STORMS. MAX TEMPS WILL RISE TO ABOVE
CLIMO VALUES. HI RES DLHWRF SHOWS A PUSH OF WARMER OFFSHORE FLOW
LATE TODAY AFTER COOLER ONSHORE FLOW INITIALLY.
TONIGHT/TOMORROW...FRNTL BDRY PUSHES FARTHER SOUTH AND EAST OF
CWA TONIGHT AS DEEP LAYER DRYING INCREASES TEMPORARILY. AN
ELONGATED MID LVL TROF NORTH OF THE BORDER WILL MOVE SOUTH
TOMORROW. A SFC COLD FRONT WILL ACT IN CONJUNCTION WITH AN
INCREASE IN MOISTURE AND INCREASE THE LIKELIHOOD OF RW/TRW SUNDAY
ACROSS MOST OF THE MN ZONES. MDLS DIFFER ON HOW FAR SOUTH
SUFFICIENT MOISTURE PUSHES. HAVE OPTED FOR THE CONSENSUS BETWEEN
THE MORE AGGRESSIVE NAM AND THE MORE NRN SOLUTION PROVIDED BY THE
ECMWF. MAX TEMPS SHOULD CLIMB INTO LOW 80S ACROSS SRN CWA WITH MID
70S ELSEWHERE.
EXTENDED...SUNDAY NIGHT THROUGH FRIDAY.
A SHORTWAVE AND INVERTED SURFACE TROUGH WILL KEEP SHOWERS AND
THUNDERSTORMS IN THE FORECAST SUNDAY NIGHT INTO MONDAY...ALTHOUGH
PROBABILITIES WILL BE DIMINISHING ON MONDAY AS HIGH PRESSURE STARTS
TO MOVE INTO THE NORTHLAND.
HIGH PRESSURE SHOULD PROVIDE DRY WEATHER MONDAY NIGHT INTO TUESDAY.
A RIDGE ALOFT WILL EXTEND NORTH THROUGH THE NORTHERN PLAINS TUESDAY
NIGHT WITH IT MOVING EAST AND FLATTENING BY FRIDAY. THE GFS SHOWS A
SHORTWAVE MOVING THROUGH THE RIDGE PROVIDING A CHANCE FOR
SHOWERS/STORMS OVER NORTHERN MINNESOTA...WITH THE ECMWF DRY. WE
FOLLOWED CLOSER TO THE GFS AT THIS TIME. WE HAVE LOW POPS INTO
FRIDAY FOR SOME SHOWERS/STORMS...BUT CONFIDENCE IS LOW FROM TUESDAY
NIGHT THROUGH FRIDAY ON RAIN CHANCES.
TEMPERATURES WILL GRADUALLY WARM THROUGH THE PERIOD...STARTING OUT
IN THE UPPER SIXTIES TO LOWER SEVENTIES MONDAY...AND WARMING TO 75
TO 80 BY THURSDAY.
AVIATION...06Z TAF ISSUANCE. MID LEVEL CEILINGS WILL PREVAIL
THROUGH NIGHT WITH SCT SHOWERS/STORMS AND POSSIBLE BRIEF MVFR
CIGS. THE EXCEPTION WILL BE AT KBRD WHERE THE THUNDER THREAT IS
MINIMAL. WINDS WILL TURN OUT OF THE SOUTHWEST THEN WEST...SATURDAY
MORNING...WITH GRADUALLY CLEARING SKIES FROM THE WEST THROUGH THE
DAY SAT.
&&
.POINT TEMPS/POPS...
DLH 76 54 78 53 / 10 10 20 50
INL 76 50 77 49 / 10 10 40 40
BRD 78 55 80 57 / 10 10 10 30
HYR 77 54 81 55 / 20 10 10 50
ASX 76 52 77 52 / 20 10 20 50
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...CANNON
LONG TERM....MELDE
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
419 AM CDT SAT JUN 15 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 420 AM CDT SAT JUN 15 2013
WIDELY SCATTERED CONVECTIVE ACTIVITY STILL NOTED AT 0.5 REFLECTIVITY
AT THIS HOUR OVER FAR EASTERN PORTIONS OF WEST CENTRAL WI. LARGE
MCS WHICH FORMED DURING THE EVENING HOURS FROM FAR SOUTHERN MN
INTO IOWA AND NORTHERN MO CONTINUES TO SLOWLY MARCH EASTWARD INTO
THE WESTERN GREAT LAKES REGION. HAVE DROPPED THE FLOOD WATCH FOR
FARIBAULT AND FREEBORN COUNTIES DUE TO LACK OF ANY APPRECIABLE
QPF ANTICIPATED TODAY ASSOCIATED WITH APPROACHING COLD FRONT.
IN ADDITION SATURATED SOIL PRESENT AFTER WEDNESDAY`S HEAVY RAIN
HAS HAD OVER 48 HOURS OF DRYING/LIMITED NEW RAINFALL EXPOSURE.
INTRODUCED SLIGHT CHANCE OF POPS TO MUCH OF CWA DURING THE AFTERNOON
ASSOCIATED WITH FRONTAL PASSAGE NOTED ABOVE. HRRR PAINTING A FAIRLY
WIDESPREAD AREA OF LIGHT SHOWERS...WITH A FEW THUNDERSTORMS FROM
SOUTH CENTRAL MN TO EAST CENTRAL MN THROUGH WEST CENTRAL WI BY
19Z. ALTHOUGH VERY HEALTHY DIVERGENCE ALOFT WILL BE PRESENT AT THIS
TIME...BELIEVE HRRR IS OVER DOING INTENSITY OF CONVECTIVE ACTIVITY.
DRYING BEHIND THE FRONT WILL ELIMINATE MOST RAINFALL AND ASSOCIATED
CLOUD DECK BY 02Z OVER FA. A NICE COOL CRISP NIGHT ANTICIPATED
TONIGHT WITH MOSTLY CLEAR SKIES AND READING DIPPING INTO THE MID
TO UPPER 50S MOST LOCALES.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 420 AM CDT SAT JUN 15 2013
SUNDAY SHOULD BE A WARM AND PRIMARILY DRY DAY...AS WESTERLY FLOW
DOMINATES IN ADVANCE OF AN ELONGATED TROUGH OVER
MANITOBA/SASKATCHEWAN/ONTARIO. MODELS HAVE EXHIBITED DECENT
CONTINUITY WITH THIS FEATURE...WHICH IS FORECAST TO DROP ACROSS
MN/WI LATE SUNDAY INTO MONDAY. ASSOCIATED MOISTURE/LIFT SHOULD BE
SUFFICIENT TO GENERATE SCATTERED SHOWERS AND THUNDERSTORMS BY 00Z
MONDAY ACROSS WEST CENTRAL MN...AND OVER THE REMAINDER OF THE
FORECAST AREA ON SUNDAY NIGHT INTO MONDAY MORNING. QPF AMOUNTS
SHOULD BE RATHER LIGHT...GENERALLY IN THE ONE TO TWO TENTHS OF AN
INCH RANGE.
TUESDAY AND WEDNESDAY FEATURE RISING MID LEVEL HEIGHTS AS THE
WESTERN RIDGE BUILDS INTO THE CENTRAL UNITED STATES. SEASONAL TEMPERATURES
IN THE MID 70S TO LOWER 80S SHOULD PREVAIL...ALONG WITH DRY
WEATHER.
AN EVEN WARMER DAY IS EXPECTED FOR THURSDAY...AS THE THERMAL RIDGE
AHEAD OF AN APPROACHING TROUGH BUILDS INTO THE AREA. SHOWERS AND
THUNDERSTORM CHANCES RE-ENTER THE FORECAST ON THURSDAY AND FRIDAY
AS LLVL MOISTURE TRANSPORT/ADVECTION NOSE INTO THE AREA. HAVE
INCLUDED 30-40 POPS AT THIS POINT...WITH HIGHER CONFIDENCE IN MORE
ORGANIZED CONVECTION NEXT FRIDAY NIGHT AND SATURDAY AS THE SURFACE
TROUGH AND ASSOCIATED BOUNDARIES PASS ACROSS IN CONJUNCTION WITH
MID LEVEL SHORTWAVE ENERGY. THIS IS ALSO THE TIME FRAME WHEN THE
JET STRUCTURE SHOULD BE SUPPLYING DECENT DIFFERENTIAL DIVERGENCE.
HAVE INCLUDED 50-60 POPS FROM 00Z SATURDAY TO 00Z SUNDAY...GIVEN
DECENT AGREEMENT BETWEEN THE 15.00Z ECMWF AND GFS SOLUTIONS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 141 AM CDT SAT JUN 15 2013
88D RADAR INDICATING FAIRLY RAPID EASTWARD MARCH OF CONVECTION OVER
PORTIONS OF WEST CENTRAL WI...AND SMALL PORTION OF SOUTH CENTRAL MN.
EXPECT MUCH OF THIS ACTIVITY TO SUBSIDE BY 09Z. IR SATELLITE
DEPICTING LARGE CLOUD SHIELD FROM SW MN INTO NW WI AND SOUTHWARD
FROM THIS LINE. AREA INDICATIVE OF MCS WHICH WILL SLOWLY TREK
EAST...BUT EXPAND SLIGHTLY NORTH PRIOR TO 12Z. SHIELD COMPRISED
OF MAINLY VFR CIGS...WITH OCNL HIGH LEVEL MVFR CIGS. WITH THAT
SAID ANTICIPATE MAINLY VFR CIGS/VSBYS OUTSIDE OF CONVECTIVE
ACTIVITY THROUGH END OF PERIOD ALL SITES. ENOUGH FORCING INDICATED
WITH APPROACHING UPPER LEVEL TROUGH LATE THIS MORNING INTO THE AFTN FOR
WIDELY SCT -SHRA OVER MUCH OF THE REGION. OF COURSE...LIGHT TO MDT
SE FLOW AHEAD OF THE FRONTAL BOUNDARY WILL SWING TO NW WINDS AROUND
10-12KTS BEHIND BOUNDARY. SKIES WILL CLEAR ALL MN AIRPORTS BY
15/21Z...AND ALL WESTERN WI TAF LOCALES BY 16/00Z.
KMSP...
SHOWERS VCNTY PRIOR TO 08Z. VFR CIGS DROPPING SLIGHTLY
AS MCS SHIELD SLOWLY MOVES EAST AND TEMPS ALOFT SLOWLY DROP.
ALTHOUGH VFR CIGS ANTICIPATED TO CLEAR BY 15Z...POSSIBILITY
EXISTS OF REDEVELOPMENT OF THIS TYPE OF CLOUD DECK NEAR 20Z
...ASSOCIATED WITH UPPER LEVEL TROUGH. VCSH ALSO A POSSIBILITY NEAR
THIS TIME PERIOD. OTHERWISE VFR CIGS/VSBYS THROUGH END OF PERIOD
...WITH SE WINDS 5 TO 10KTS...BECOMING NW 10-12KTS BY 16Z.
/OUTLOOK FOR KMSP/
SUN...VFR. WSW WINDS 5-10KTS.
MON...CHANCE OF MVFR CONDS AND TSRA. NW WINDS 10KTS.
TUE...VFR. WINDS LGT AND VRB.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...AJZ
LONG TERM...LS
AVIATION...AJZ
AREA FORECAST DISCUSSION...CORRECTED
NWS HASTINGS NE
404 PM CDT SAT JUN 15 2013
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 306 PM CDT SAT JUN 15 2013
TONIGHT THROUGH SUNDAY AFTERNOON. PRIMARY CONCERN WILL CENTER
AROUND THUNDERSTORM CHANCES. WILL NOT MAKE THIS TOO DETAILED TODAY
JUST IN CASE CONVECTION GETS GOING BY MID AFTERNOON.
CURRENT WATER VAPOR IMAGERY AND UPPER AIR DATA SHOWING CLOSED
UPPER LOW OVER SASKATCHEWAN CANADA WITH BROAD TROUGH INTO THE
NORTHERN PLAINS. THIS FEATURE GIVING THE NORTHERN PART OF OUR CWA
A LITTLE STRONGER DEEP LAYER SHEAR THAN THE SOUTHERN PART DUE TO
THE STRONGER WESTERLY FLOW. ANOTHER WEAK WAVE FROM KS TO TX HAS
HELPED DEVELOP/SUSTAIN NON SEVERE CONVECTION OVER THE SOUTHERN AND
SOUTHEAST PART OF THE CWA THIS MORNING...AND WAS JUST PUSHING TO
THE EAST OF THE AREA BY 1 PM CDT. ALSO ON THE VISIBLE SATELLITE
IMAGERY...LOOKS LIKE AN MCV OR NEDDY EDDY SWIRLING FROM THE SOUTH
CENTRAL INTO THE EASTERN PART OF THE CWA EARLY THIS AFTERNOON BUT
WOULD EXPECT ANY EFFECTS FROM THIS TO BE TO OUR EAST. DIFFICULT TO
PLACE THE SURFACE BOUNDARY EARLY THIS AFTERNOON DUE TO DIFFUSE
NATURE OF THE BOUNDARY AND EXTENSIVE CLOUD COVER THAT PASSED
ACROSS OUR SOUTHERN CWA THIS MORNING. BY 17Z THE BOUNDARY APPEARED
TO BE LYING FROM THE SOUTHWEST TO THE NORTHEAST PART OF THE CWA.
BEST SURFACE MOISTURE POOLING IN THIS AREA WITH UPPER 60S FOR
DEWPOINTS...AS COMPARED TO THE 50S NORTHWEST OF THE CWA. TO GO
ALONG WITH THIS...ML CAPES THE HIGHEST HERE AT 17Z WITH VALUES
AROUND 1500 J/KG. 0-6 KM SHEAR AT 50 KT ALONG NEB/SDAK BORDER...30
KT IN THE NORTHERN PART OF THE CWA AND LESS THAN THAT IN OUR
SOUTH.
FIRST QUESTION THEN IS WILL THUNDERSTORMS POP THIS AFTERNOON AND
TO WHAT EXTENT. THE 4KM WRF DEVELOPS CONVECTION ALONG THE FRONT
LATE THIS AFTERNOON AND THEN SAGS IT SOUTH DURING THE EVENING. IT
ALSO DEVELOPS AN MCS OVER NORTHEAST COLORADO THIS EVENING AND THEN
SLIDES IT EAST ACROSS NORTHERN KS OVERNIGHT. THIS SCENARIO ALSO
SUPPORTED BY SEVERAL RUNS OF THE HRRR TODAY. QUESTION HERE IS WILL
THE TRACK TAKE IT ACROSS OR JUST SOUTH OF OUR KS COUNTIES. WILL
MOST LIKELY KEEP AT LEAST A SLIGHT CHANCE IN THE NORTH LATER TODAY
INTO THE EVENING WITH A LITTLE BIT BETTER CHANCES ACROSS KS. SO
FAR SEVERE CHANCES LATER THIS AFTERNOON DO NOT LOOK THAT PROMISING
DUE TO THE LACK OF MID LEVEL FORCING AND WEAK SHEAR. COULD SEE
SOME SEVERE THUNDERSTORMS OVERNIGHT IF MCS SCENARIO MATERIALIZES.
THE SITUATION IS NOT MUCH CLEARER FOR SUNDAY WITH LOCATIONS OF THE
SURFACE BOUNDARIES STILL A BIT OF A QUESTION. IT DOES LOOK LIKE WE
COULD HAVE SOME MID LEVEL SUPPORT AND INSTABILITY AND SHEAR
PARAMETERS LOOKING MORE FAVORABLE THAN THEY DO TODAY. LATEST DAY 2
OUTLOOK FROM SPC HAS AREA IN A SLIGHT RISK. THEY MENTION THAT
CONDITIONS LOOK FAVORABLE FOR A LINEAR SYSTEM TO DEVELOP WITH
DAMAGING WINDS THE GREATEST THREAT ALTHOUGH EARLY ON WE COULD SEE
DISCRETE CELLS WITH LARGE HAIL...DAMAGING WINDS AND A FEW
TORNADOES POSSIBLE. WILL PROBABLY HAVE HIGHEST POPS IN THE SOUTH
FOR SUNDAY...CLOSER TO EXPECTED LOCATION OF THE SURFACE BOUNDARY.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 306 PM CDT SAT JUN 15 2013
GUIDANCE FROM THE NAM...OPERATIONAL GFS...EC...AND SREF-MEAN
SUGGESTS A MID TO UPPER LEVEL RIDGE WILL LINGER OVER THE ROCKY
MOUNTAIN RANGE MONDAY AND TUESDAY...THUS HELPING PROMOTE
NORTHWESTERLY MID TO UPPER LEVEL FLOW OVER THE CENTRAL PLAINS.
PERIODIC MID LEVEL PERTURBATIONS ARE EXPECTED TO PUSH OVER OUR
AREA WITHIN THE MEAN MID LEVEL FLOW...THUS PRESENTING PERIODS OF
INCREASED OMEGA. SUNDAY NIGHT INTO EARLY MONDAY MORNING IS ONE
SUCH TIME PERIOD WITH QPF FIELDS FROM THE OPERATIONAL GFS...EC
...SREF-MEAN...AND TO A LESSER EXTENT THE NAM...ALL SUGGESTING
MEASURABLE PRECIPITATION WILL BE REALIZED OVER OUR AREA.
MAINTAINED THE ~50% POPS INHERITED FROM THE PREVIOUS FORECAST FOR
SUNDAY NIGHT INTO EARLY MONDAY MORNING AS A RESULT. MONDAY INTO
TUESDAY...POP-RELATED DETAILS BECOME MURKY AT BEST...WITH VARIOUS
MODELS SUGGESTING THE AFOREMENTIONED MID LEVEL PERTURBATIONS WILL
MOVE OVER SOME PORTION OF OUR CWA AT SOME POINT IN TIME. RESULTANT
QPF FIELDS ARE ALL OVER THE PLACE AS A RESULT...THUS MAKING IT
DIFFICULT TO PIN DOWN AN EXACT LOCATION TO PLACE POPS. THAT BEING
SAID...THERE DOES SEEM TO BE SOME AGREEMENT BETWEEN THE
NAM...EC...AND SREF-MEAN OF MEASURABLE PRECIPITATION BEING
REALIZED SOMEWHERE ACROSS OUR WEST/SOUTHWESTERN CWA BOTH MONDAY
AND TUESDAY DURING THE AFTERNOON AND EVENING HOURS. FORECAST
PROXIMITY SOUNDINGS FROM ACROSS OUR WEST/SOUTHWEST...PER THE
NAM...EC...AND EVEN THE OPERATIONAL GFS DESPITE ITS DRY QPF OUTPUT
ON BOTH DAYS...SUGGEST STEEP LOW TO MID LEVEL LAPSE RATES MAY
ALLOW A FEW LOCATIONS TO AUTO-CONVECT ACROSS THE HIGHER TERRAIN OF
OUR WEST/SOUTHWESTERN CWA. GIVEN THE MODEST CONSENSUS FROM MODEL
QPF FIELDS...AS WELL AS THE LOW TO MID LEVEL LAPSE RATES SUGGESTED
BY THE AFOREMENTIONED FORECAST PROXIMITY SOUNDINGS...WENT AHEAD
WITH ~20% POPS ACROSS ROUGHLY THE WEST/SOUTHWESTERN ONE-THIRD OF
OUR CWA FOR THE AFTERNOON AND EVENING HOURS ON MONDAY AND TUESDAY.
WEDNESDAY AND BEYOND...THE OPERATIONAL GFS AND EC BOTH SUGGEST MID
TO UPPER LEVEL FLOW WILL TRANSITION FROM THE NORTHWEST TO MORE OF
A SOUTHWESTERLY DIRECTION...WITH MULTIPLE MID LEVEL PERTURBATIONS
MOVING OVER THE REGION. ALLBLEND RESPONDED BY PROVIDING 20-50%
POPS FOR VARIOUS POINTS ACROSS OUR CWA DURING VARIOUS TIME
PERIODS. TIMING AND POSITION DETAILS WITH RESPECT TO ANY OF THE
MID LEVEL PERTURBATIONS MID TO LATE NEXT WEEK WILL LIKELY NOT
BECOME ANY MORE CLEAR FOR A COUPLE MORE DAYS AND AS A RESULT...THE
PROBABILITY OF SUCCESSFULLY IMPROVING THE FORECAST AS PROVIDED BY
ALLBLEND IS LOW. GIVEN THIS LOW PROBABILITY...OPTED TO LEAVE THE
ALLBLEND POPS UNCHANGED FOR THE MOST PART.
FORECAST PROXIMITY SOUNDINGS FROM ACROSS OUR CWA...IN PARTICULAR
THE NAM...SUGGEST ASCENDING PARCELS ROOTED TO BETWEEN 825MB AND
750MB WILL HAVE ~1500J/KG TO WORK WITH SUNDAY NIGHT INTO EARLY
MONDAY MORNING. IN ADDITION TO THIS POTENTIAL ENERGY...DEEP LAYER
BULK SHEAR VALUES OF ~30KTS ARE ALSO FORECAST ACROSS MUCH OF OUR
AREA. ALTHOUGH CONFIDENCE IS NOT OVERLY HIGH WITH RESPECT TO
SEVERE WEATHER CHANCES SUNDAY NIGHT INTO EARLY MONDAY
MORNING...WILL GO AHEAD AND MAINTAIN SEVERE WEATHER WORDING IN THE
HWO FOR SUNDAY NIGHT AND EARLY MONDAY MORNING. SEVERE WEATHER
COULD BE OBSERVED SHOULD THUNDERSTORM ACTIVITY BE REALIZED ACROSS
OUR WEST/SOUTHWESTERN CWA DURING THE AFTERNOON AND/OR EVENING
HOURS MONDAY AND TUESDAY...WITH THE NAM...OPERATIONAL GFS...AND EC
ALL SUGGESTING DEEP LAYER MUCAPE VALUES GENERALLY IN THE
2000-3000J/KG RANGE. DEEP LAYER BULK SHEAR VALUES ON THE ORDER OF
~30KTS ARE ALSO FORECAST. GIVEN ALL THIS...WILL GO AHEAD AND
OUTLOOK THE THREAT FOR ISOLATED SEVERE WEATHER BOTH MONDAY AND
TUESDAY ACROSS OUR WEST/SOUTHWEST. MUCH LIKE THE OVERALL POP
FORECAST...DETAILS REGARDING SEVERE WEATHER TIMING AND POSITION
WEDNESDAY AND BEYOND WILL NOT LIKELY BECOME ANY MORE CLEAR FOR A
COUPLE MORE DAYS AND AS A RESULT...WILL CONTINUE THE GENERAL
THUNDERSTORM MENTION IN THE HWO FOR THE TIME BEING.
LITTLE CHANGE IN THE LOW LEVEL AIRMASS SHOULD PRESENT SIMILAR
TEMPERATURES BETWEEN MONDAY AND WEDNESDAY...WITH AFTERNOON HIGH
TEMPERATURE GENERALLY IN THE 80S CURRENTLY FORECAST. LOW LEVEL
SOUTHERLY FLOW AND RESULTANT LOW LEVEL WARM AIR ADVECTION
BEGINNING WEDNESDAY HOWEVER...SHOULD PROMOTE A WARMING TREND TO
FINISH OUT THE FORECAST PERIOD...WITH AFTERNOON HIGH TEMPERATURES
IN THE UPPER 80S AND 90S EXPECTED FOR THE MOST LOCATIONS BY LATE
NEXT WEEK. OVERNIGHT TEMPERATURES IN THE 60S ARE FORECAST FOR MOST
LOCATIONS THROUGH WEDNESDAY NIGHT...WITH LOWS CREEPING INTO THE
70S FOR SOME LOCATIONS BY LATE NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAF THROUGH 18Z SUNDAY AFTERNOON) ISSUED
AT 1223 PM CDT SAT JUN 15 2013
WIND DIRECTION AND SMALL CHANCES FOR THUNDERSTORMS THIS AFTERNOON
ARE MAIN CONCERNS IN THE TAF. TERMINAL AREA STILL LYING NORTH OF
FRONTAL BOUNDARY WITH RESULTING EASTERLY WINDS. THESE COULD SWITCH
TO MORE OF A NORTHERLY DIRECTION THIS AFTERNOON IF BOUNDARY SAGS
SOUTH AS PROGGED. NOT A LOT OF SUPPORT FOR WIDESPREAD
THUNDERSTORMS THIS AFTERNOON BUT ISOLATED ACTIVITY ONGOING AND
EXPECTED TO INCREASE JUST A BIT OVER THE NEXT FEW HOURS AS WE NEAR
PEAK HEATING. WILL GO WITH VICINITY WORDING DUE TO EXPECTED
LIMITED COVERAGE. OTHERWISE WINDS WILL GO VARIABLE OVERNIGHT AND
FOG A POSSIBILITY AROUND SUNRISE SUNDAY.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...EWALD
LONG TERM...BRYANT
AVIATION...EWALD
AREA FORECAST DISCUSSION
NWS HASTINGS NE
306 PM CDT SAT JUN 15 2013
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 306 PM CDT SAT JUN 15 2013
TONIGHT THROUGH SUNDAY AFTERNOON. PRIMARY CONCERN WILL CENTER
AROUND THUNDERSTORM CHANCES. WILL NOT MAKE THIS TOO DETAILED TODAY
JUST IN CASE CONVECTION GETS GOING BY MID AFTERNOON.
CURRENT WATER VAPOR IMAGERY AND UPPER AIR DATA SHOWING CLOSED
UPPER LOW OVER SASKATCHEWAN CANADA WITH BROAD TROUGH INTO THE
NORTHERN PLAINS. THIS FEATURE GIVING THE NORTHERN PART OF OUR CWA
A LITTLE STRONGER DEEP LAYER SHEAR THAN THE SOUTHERN PART DUE TO
THE STRONGER WESTERLY FLOW. ANOTHER WEAK WAVE FROM KS TO TX HAS
HELPED DEVELOP/SUSTAIN NON SEVERE CONVECTION OVER THE SOUTHERN AND
SOUTHEAST PART OF THE CWA THIS MORNING...AND WAS JUST PUSHING TO
THE EAST OF THE AREA BY 1 PM CDT. ALSO ON THE VISIBLE SATELLITE
IMAGERY...LOOKS LIKE AN MCV OR NEDDY EDDY SWIRLING FROM THE SOUTH
CENTRAL INTO THE EASTERN PART OF THE CWA EARLY THIS AFTERNOON BUT
WOULD EXPECT ANY EFFECTS FROM THIS TO BE TO OUR EAST. DIFFICULT TO
PLACE THE SURFACE BOUNDARY EARLY THIS AFTERNOON DUE TO DIFFUSE
NATURE OF THE BOUNDARY AND EXTENSIVE CLOUD COVER THAT PASSED
ACROSS OUR SOUTHERN CWA THIS MORNING. BY 17Z THE BOUNDARY APPEARED
TO BE LYING FROM THE SOUTHWEST TO THE NORTHEAST PART OF THE CWA.
BEST SURFACE MOISTURE POOLING IN THIS AREA WITH UPPER 60S FOR
DEWPOINTS...AS COMPARED TO THE 50S NORTHWEST OF THE CWA. TO GO
ALONG WITH THIS...ML CAPES THE HIGHEST HERE AT 17Z WITH VALUES
AROUND 1500 J/KG. 0-6 KM SHEAR AT 50 KT ALONG NEB/SDAK BORDER...30
KT IN THE NORTHERN PART OF THE CWA AND LESS THAN THAT IN OUR
SOUTH.
FIRST QUESTION THEN IS WILL THUNDERSTORMS POP THIS AFTERNOON AND
TO WHAT EXTENT. THE 4KM WRF DEVELOPS CONVECTION ALONG THE FRONT
LATE THIS AFTERNOON AND THEN SAG IT SOUTH DURING THE EVENING. IT
ALSO DEVELOPS AN MCS OVER NORTHEAST COLORADO THIS EVENING AND THEN
SLIDES IT EAST ACROSS NORTHERN KS OVERNIGHT. THIS SCENARIO ALSO
SUPPORTED BY SEVERAL RUNS OF THE HRRR TODAY. QUESTION HERE IS WILL
THE TRACK TAKE IT ACROSS OR JUST SOUTH OF OUR KS COUNTIES. WILL
MOST LIKELY KEEP AT LEAST A SLIGHT CHANCE IN THE NORTH LATER TODAY
INTO THE EVENING WITH A LITTLE BIT BETTER CHANCES ACROSS KS. SO
FAR SEVERE CHANCES LATER THIS AFTERNOON DO NOT LOOK THAT PROMISING
DUE TO THE LACK OF MID LEVEL FORCING AND WEAK SHEAR. COULD SEE
SOME SEVERE OVERNIGHT IF MCS SCENARIO MATERIALIZES.
THE SITUATION IS NOT MUCH CLEARER FOR SUNDAY WITH LOCATIONS OF THE
SURFACE BOUNDARIES STILL A BIT OF OF QUESTION. IT DOES LOOK LIKE
WE COULD HAVE SOME MID LEVEL SUPPORT AND INSTABILITY AND SHEAR
PARAMETERS LOOKING MORE FAVORABLE THAN THEY DO TODAY. LATEST DAY 2
OUTLOOK FROM SPC HAS AREA IN A SLIGHT RISK. THEY MENTION THAT
CONDITIONS LOOK FAVORABLE FOR A LINEAR SYSTEM TO DEVELOP WITH
DAMAGING WINDS THE GREATEST THREAT ALTHOUGH EARLY ON WE COULD SEE
DISCRETE CELLS WITH LARGE HAIL...DAMAGING WINDS AND A FEW
TORNADOES POSSIBLE. WILL PROBABLY HAVE HIGHEST POPS IN THE SOUTH
FOR SUNDAY...CLOSER TO EXPECTED LOCATION OF THE SURFACE BOUNDARY.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 306 PM CDT SAT JUN 15 2013
GUIDANCE FROM THE NAM...OPERATIONAL GFS...EC...AND SREF-MEAN
SUGGESTS A MID TO UPPER LEVEL RIDGE WILL LINGER OVER THE ROCKY
MOUNTAIN RANGE MONDAY AND TUESDAY...THUS HELPING PROMOTE
NORTHWESTERLY MID TO UPPER LEVEL FLOW OVER THE CENTRAL PLAINS.
PERIODIC MID LEVEL PERTURBATIONS ARE EXPECTED TO PUSH OVER OUR
AREA WITHIN THE MEAN MID LEVEL FLOW...THUS PRESENTING PERIODS OF
INCREASED OMEGA. SUNDAY NIGHT INTO EARLY MONDAY MORNING IS ONE
SUCH TIME PERIOD WITH QPF FIELDS FROM THE OPERATIONAL GFS...EC
...SREF-MEAN...AND TO A LESSER EXTENT THE NAM...ALL SUGGESTING
MEASURABLE PRECIPITATION WILL BE REALIZED OVER OUR AREA.
MAINTAINED THE ~50% POPS INHERITED FROM THE PREVIOUS FORECAST FOR
SUNDAY NIGHT INTO EARLY MONDAY MORNING AS A RESULT. MONDAY INTO
TUESDAY...POP-RELATED DETAILS BECOME MURKY AT BEST...WITH VARIOUS
MODELS SUGGESTING THE AFOREMENTIONED MID LEVEL PERTURBATIONS WILL
MOVE OVER SOME PORTION OF OUR CWA AT SOME POINT IN TIME. RESULTANT
QPF FIELDS ARE ALL OVER THE PLACE AS A RESULT...THUS MAKING IT
DIFFICULT TO PIN DOWN AN EXACT LOCATION TO PLACE POPS. THAT BEING
SAID...THERE DOES SEEM TO BE SOME AGREEMENT BETWEEN THE
NAM...EC...AND SREF-MEAN OF MEASURABLE PRECIPITATION BEING
REALIZED SOMEWHERE ACROSS OUR WEST/SOUTHWESTERN CWA BOTH MONDAY
AND TUESDAY DURING THE AFTERNOON AND EVENING HOURS. FORECAST
PROXIMITY SOUNDINGS FROM ACROSS OUR WEST/SOUTHWEST...PER THE
NAM...EC...AND EVEN THE OPERATIONAL GFS DESPITE ITS DRY QPF OUTPUT
ON BOTH DAYS...SUGGEST STEEP LOW TO MID LEVEL LAPSE RATES MAY
ALLOW A FEW LOCATIONS TO AUTO-CONVECT ACROSS THE HIGHER TERRAIN OF
OUR WEST/SOUTHWESTERN CWA. GIVEN THE MODEST CONSENSUS FROM MODEL
QPF FIELDS...AS WELL AS THE LOW TO MID LEVEL LAPSE RATES SUGGESTED
BY THE AFOREMENTIONED FORECAST PROXIMITY SOUNDINGS...WENT AHEAD
WITH ~20% POPS ACROSS ROUGHLY THE WEST/SOUTHWESTERN ONE-THIRD OF
OUR CWA FOR THE AFTERNOON AND EVENING HOURS ON MONDAY AND TUESDAY.
WEDNESDAY AND BEYOND...THE OPERATIONAL GFS AND EC BOTH SUGGEST MID
TO UPPER LEVEL FLOW WILL TRANSITION FROM THE NORTHWEST TO MORE OF
A SOUTHWESTERLY DIRECTION...WITH MULTIPLE MID LEVEL PERTURBATIONS
MOVING OVER THE REGION. ALLBLEND RESPONDED BY PROVIDING 20-50%
POPS FOR VARIOUS POINTS ACROSS OUR CWA DURING VARIOUS TIME
PERIODS. TIMING AND POSITION DETAILS WITH RESPECT TO ANY OF THE
MID LEVEL PERTURBATIONS MID TO LATE NEXT WEEK WILL LIKELY NOT
BECOME ANY MORE CLEAR FOR A COUPLE MORE DAYS AND AS A RESULT...THE
PROBABILITY OF SUCCESSFULLY IMPROVING THE FORECAST AS PROVIDED BY
ALLBLEND IS LOW. GIVEN THIS LOW PROBABILITY...OPTED TO LEAVE THE
ALLBLEND POPS UNCHANGED FOR THE MOST PART.
FORECAST PROXIMITY SOUNDINGS FROM ACROSS OUR CWA...IN PARTICULAR
THE NAM...SUGGEST ASCENDING PARCELS ROOTED TO BETWEEN 825MB AND
750MB WILL HAVE ~1500J/KG TO WORK WITH SUNDAY NIGHT INTO EARLY
MONDAY MORNING. IN ADDITION TO THIS POTENTIAL ENERGY...DEEP LAYER
BULK SHEAR VALUES OF ~30KTS ARE ALSO FORECAST ACROSS MUCH OF OUR
AREA. ALTHOUGH CONFIDENCE IS NOT OVERLY HIGH WITH RESPECT TO
SEVERE WEATHER CHANCES SUNDAY NIGHT INTO EARLY MONDAY
MORNING...WILL GO AHEAD AND MAINTAIN SEVERE WEATHER WORDING IN THE
HWO FOR SUNDAY NIGHT AND EARLY MONDAY MORNING. SEVERE WEATHER
COULD BE OBSERVED SHOULD THUNDERSTORM ACTIVITY BE REALIZED ACROSS
OUR WEST/SOUTHWESTERN CWA DURING THE AFTERNOON AND/OR EVENING
HOURS MONDAY AND TUESDAY...WITH THE NAM...OPERATIONAL GFS...AND EC
ALL SUGGESTING DEEP LAYER MUCAPE VALUES GENERALLY IN THE
2000-3000J/KG RANGE. DEEP LAYER BULK SHEAR VALUES ON THE ORDER OF
~30KTS ARE ALSO FORECAST. GIVEN ALL THIS...WILL GO AHEAD AND
OUTLOOK THE THREAT FOR ISOLATED SEVERE WEATHER BOTH MONDAY AND
TUESDAY ACROSS OUR WEST/SOUTHWEST. MUCH LIKE THE OVERALL POP
FORECAST...DETAILS REGARDING SEVERE WEATHER TIMING AND POSITION
WEDNESDAY AND BEYOND WILL NOT LIKELY BECOME ANY MORE CLEAR FOR A
COUPLE MORE DAYS AND AS A RESULT...WILL CONTINUE THE GENERAL
THUNDERSTORM MENTION IN THE HWO FOR THE TIME BEING.
LITTLE CHANGE IN THE LOW LEVEL AIRMASS SHOULD PRESENT SIMILAR
TEMPERATURES BETWEEN MONDAY AND WEDNESDAY...WITH AFTERNOON HIGH
TEMPERATURE GENERALLY IN THE 80S CURRENTLY FORECAST. LOW LEVEL
SOUTHERLY FLOW AND RESULTANT LOW LEVEL WARM AIR ADVECTION
BEGINNING WEDNESDAY HOWEVER...SHOULD PROMOTE A WARMING TREND TO
FINISH OUT THE FORECAST PERIOD...WITH AFTERNOON HIGH TEMPERATURES
IN THE UPPER 80S AND 90S EXPECTED FOR THE MOST LOCATIONS BY LATE
NEXT WEEK. OVERNIGHT TEMPERATURES IN THE 60S ARE FORECAST FOR MOST
LOCATIONS THROUGH WEDNESDAY NIGHT...WITH LOWS CREEPING INTO THE
70S FOR SOME LOCATIONS BY LATE NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAF THROUGH 18Z SUNDAY AFTERNOON) ISSUED
AT 1223 PM CDT SAT JUN 15 2013
WIND DIRECTION AND SMALL CHANCES FOR THUNDERSTORMS THIS AFTERNOON
ARE MAIN CONCERNS IN THE TAF. TERMINAL AREA STILL LYING NORTH OF
FRONTAL BOUNDARY WITH RESULTING EASTERLY WINDS. THESE COULD SWITCH
TO MORE OF A NORTHERLY DIRECTION THIS AFTERNOON IF BOUNDARY SAGS
SOUTH AS PROGGED. NOT A LOT OF SUPPORT FOR WIDESPREAD
THUNDERSTORMS THIS AFTERNOON BUT ISOLATED ACTIVITY ONGOING AND
EXPECTED TO INCREASE JUST A BIT OVER THE NEXT FEW HOURS AS WE NEAR
PEAK HEATING. WILL GO WITH VICINITY WORDING DUE TO EXPECTED
LIMITED COVERAGE. OTHERWISE WINDS WILL GO VARIABLE OVERNIGHT AND
FOG A POSSIBILITY AROUND SUNRISE SUNDAY.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...EWALD
LONG TERM...BRYANT
AVIATION...EWALD
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1234 PM CDT SAT JUN 15 2013
.DISCUSSION...
HAVE ADJUSTED PRECIP TRENDS AND TEMPS FOR THE REST OF THE DAY.
NORTHWEST CWA MAY SEE ONLY ISOLATED ACTIVITY FOR THE REST OF
TODAY...WHILE A BAND OF SHRA/TSRA ALSO IS DEVELOPING FROM AROUND
COLUMBUS TO ONAWA...TIED TO THE LIKELY SYNOPTIC FRONT IN A SEA OF
OUTFLOW BOUNDARIES. THAT LINE WILL SAG SOUTHEAST THROUGH THE
AFTERNOON AND EVENING. ALSO...AN AREA OF RAIN WITH SOME EMBEDDED
THUNDER IS MOVING OUT OF NORTH CENTRAL KS INTO THE SOUTHWEST CWA.
HAVE DECREASED POPS SOUTH AND ADJUSTED TIMING FOR THESE TWO MAIN
AREAS OF PRECIP. DID USE THUNDERSTORM WORDING AS LIGHTNING
ACTIVITY SHOULD INCREASE THIS AFTERNOON. THAT SAID ...MID-LEVEL
LAPSE RATES ARE NOT GREAT IN MOST OF THE CWA AS AIRMASS WAS
OVERTURNED WITH CONVECTION LAST NIGHT...WITH HIGHEST LAPSE RATES
ALONG AND EAST OF THE MO RIVER. LATEST MESOANALYSIS INDICATES
1500-2000 J/GK OF MLCAPE FROM I-80 SOUTHWARD...WTIH HIGHEST CAPE
TO THE SOUTH IN EASTERN KS/WESTERN MO...AND WITH CAP ERODING.
EFFECTIVE BULK SHEAR IS WEAK IN THAT REGION THOUGH.
OVERALL...THINK SEVERE THUNDERSTORM THREAT IS LOW AND LIMITED TO
AREAS SOUTH OF I-80...WITH WIND MORE OF A THREAT THAN HAIL...AND
WITH LOCALLY HEAVY RAIN POSSIBLE AS PWATS REMAIN AROUND 1.5
INCHES ACROSS THE AREA.
MAYES
&&
.AVIATION...
18Z TAFS FOR KOMA...KLNK...AND KOFK.
VFR CONDITIONS WILL DOMINATE THROUGH THE TAF CYCLE. SHOWERS ARE
DEVELOPING NEAR OR MOVING TOWARD ALL THREE TAF SITES...AND HAVE
INCLUDED VCSH WORDING THIS AFTERNOON. BELIEVE SHOWERS SHOULD STAY
SOUTH OF KOFK...BUT MAY SEE SHRA MOVE INTO KOMA/KLNK LATER THIS
AFTERNOON...AND HAVE INCLUDED TEMPO WORDING FOR A FIRST GUESS ON
TIMING. KEPT THUNDER OUT FOR NOW AS STORMS WILL NOT BE
WIDESPREAD...BUT WILL NEED TO MONITOR TAFS THIS AFTERNOON AND
UPDATE IF THUNDER IS THREATENING THE SITES. WIND SPEEDS WILL TREND
DOWNWARD TODAY...WITH DIRECTIONS VARIABLE THROUGH SUNDAY MORNING.
MAYES
&&
.PREV DISCUSSION... /ISSUED 338 AM CDT SAT JUN 15 2013/
DISCUSSION...
..MAIN FORECAST CONCERN WILL CENTER AROUND THUNDERSTORM CHANCES
TODAY...
LATEST WATER VAPOR IMAGERY AND 500 MB RAP ANALYSIS SHOWS
SOUTHWESTERLY FLOW ALOFT WITH A CLOSED LOW OVER SOUTHERN SASKATCHEWAN
AND A RIDGE AXIS JUST TO OUR EAST. EMBEDDED IN THE SOUTHWESTERLY
FLOW IS A SHORTWAVE CURRENTLY OVER THE OKLAHOMA/TEXAS PANHANDLE. AT
THE SURFACE...A BOUNDARY EXTENDS EAST NORTHEAST FROM WESTERN
KANSAS INTO EAST CENTRAL NEBRASKA. DEWPOINTS ALONG AND SOUTH OF
THE BOUNDARY ARE POOLED IN THE MID TO UPPER 60S.
AS PER THE LATEST RAP/HRRR/NAM...THINK THERE WILL BE TWO AREAS OF
MORNING CONVECTION. THE FIRST WILL BE THE ONGOING ACTIVITY ACROSS
THE NEBRASKA PANHANDLE WHICH DRIFTS EAST-NORTHEAST THROUGHOUT THE
MORNING. THE SECOND WILL BE IN ASSOCIATION TO THE NORTHEAST MOVING
CENTRAL PLAINS SHORTWAVE. MOST UNSTABLE AIRMASS WILL BE SOUTH OF
THE ABOVE MENTIONED SFC BOUNDARY AND THIS WILL LIKELY BECOME
ACTIVE THIS AFTERNOON AS THE UPPER LEVEL SUPPORT APPROACHES.
CONVECTIVE ACTIVITY IS FORECAST TO SHIFT SOUTH INTO KANSAS AND
MISSOURI BY EVENING AS THE SFC BOUNDARY DROPS SOUTH AND UPPER
LEVEL FLOW BECOMES MORE ZONAL.
MUCH OF SUNDAY MORNING LOOKS QUIET ACROSS THE FORECAST AREA. THE
FRONTAL BOUNDARY IS FORECAST TO PUSH NORTH LATER IN THE DAY SUNDAY
AND STORMS MAY FIRE TO OUR WEST AND POTENTIALLY EVOLVE INTO AN
MCS AND SLIDE EAST-SOUTHEAST SUNDAY LATE AFTERNOON AND EVENING
CLIPPING OUR SOUTHWESTERN COUNTIES.
MUCH OF MONDAY AND TUESDAY LOOK TO BE DRY WITH WEAK SFC HIGH
PRESSURE BUILDING OVER THE REGION. UPPER RIDGING BEGINS TO BUILD
OVER THE CENTRAL PLAINS BY EARLY WEDNESDAY. A FEW IMPULSES ARE
PROGGED TO MOVE UP AND OVER THE RIDGE AND SO CANNOT DISCOUNT ANY
CHANCE OF TSTMS IN THAT PATTERN WHILE A SFC BOUNDARY STRETCHES
ACROSS THE FORECAST AREA.
KERN
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
338 AM CDT SAT JUN 15 2013
.DISCUSSION...
...MAIN FORECAST CONCERN WILL CENTER AROUND THUNDERSTORM CHANCES
TODAY...
LATEST WATER VAPOR IMAGERY AND 500 MB RAP ANALYSIS SHOWS
SOUTHWESTERLY FLOW ALOFT WITH A CLOSED LOW OVER SOUTHERN SASKATCHEWAN
AND A RIDGE AXIS JUST TO OUR EAST. EMBEDDED IN THE SOUTHWESTERLY
FLOW IS A SHORTWAVE CURRENTLY OVER THE OKLAHOMA/TEXAS PANHANDLE. AT
THE SURFACE...A BOUNDARY EXTENDS EAST NORTHEAST FROM WESTERN
KANSAS INTO EAST CENTRAL NEBRASKA. DEWPOINTS ALONG AND SOUTH OF
THE BOUNDARY ARE POOLED IN THE MID TO UPPER 60S.
AS PER THE LATEST RAP/HRRR/NAM...THINK THERE WILL BE TWO AREAS OF
MORNING CONVECTION. THE FIRST WILL BE THE ONGOING ACTIVITY ACROSS
THE NEBRASKA PANHANDLE WHICH DRIFTS EAST-NORTHEAST THROUGHOUT THE
MORNING. THE SECOND WILL BE IN ASSOCIATION TO THE NORTHEAST MOVING
CENTRAL PLAINS SHORTWAVE. MOST UNSTABLE AIRMASS WILL BE SOUTH OF
THE ABOVE MENTIONED SFC BOUNDARY AND THIS WILL LIKELY BECOME
ACTIVE THIS AFTERNOON AS THE UPPER LEVEL SUPPORT APPROACHES.
CONVECTIVE ACTIVITY IS FORECAST TO SHIFT SOUTH INTO KANSAS AND
MISSOURI BY EVENING AS THE SFC BOUNDARY DROPS SOUTH AND UPPER
LEVEL FLOW BECOMES MORE ZONAL.
MUCH OF SUNDAY MORNING LOOKS QUIET ACROSS THE FORECAST AREA. THE
FRONTAL BOUNDARY IS FORECAST TO PUSH NORTH LATER IN THE DAY SUNDAY
AND STORMS MAY FIRE TO OUR WEST AND POTENTIALLY EVOLVE INTO AN
MCS AND SLIDE EAST-SOUTHEAST SUNDAY LATE AFTERNOON AND EVENING
CLIPPING OUR SOUTHWESTERN COUNTIES.
MUCH OF MONDAY AND TUESDAY LOOK TO BE DRY WITH WEAK SFC HIGH
PRESSURE BUILDING OVER THE REGION. UPPER RIDGING BEGINS TO BUILD
OVER THE CENTRAL PLAINS BY EARLY WEDNESDAY. A FEW IMPULSES ARE
PROGGED TO MOVE UP AND OVER THE RIDGE AND SO CANNOT DISCOUNT ANY
CHANCE OF TSTMS IN THAT PATTERN WHILE A SFC BOUNDARY STRETCHES
ACROSS THE FORECAST AREA.
KERN
&&
.AVIATION...06Z TAFS FOR KOFK...KOMA AND KLNK.
CONVECTION REMAINS PRIMARY AVIATION CONCERN. NEW DEVELOPMENT IN
SRN NEBR POSES A RISK MAINLY AT KLNK/KOMA EARLY IN FORECAST
PERIOD WITH OTHER ACTIVITY IN WRN NEBRASKA MOVING TOWARD REGION
LATE TONIGHT/SATURDAY MORNING. GUSTY VARIABLE BUT MOSTLY SE WINDS
IN WAKE OF EARLIER CONVECTION CAN BE EXPECTED EARLY TONIGHT NEAR
FIRST BATCH OF CONVECTION THAT WILL IMPACT KLNK/KOMA. THE SECOND
AREA OF CONVECTION IN WRN NEBR WAS EXPECTED TO IMPACT THE KOFK
VICINITY SATURDAY MORNING...WITH NEW DEVELOPMENT LIKELY SEWD
THROUGH THE AFTERNOON. THUS ADDITIONAL TSTM MENTION WAS CARRIED AT
KOMA/KLNK. AREAS OF MVFR CIGS LIKELY TO DEVELOP BEHIND THIS SECOND
CONVECTIVE BAND BY SATURDAY MORNING...ESPECIALLY OVER NERN NEBR.
CHERMOK
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
99/99
AREA FORECAST DISCUSSION
NWS RALEIGH NC
940 PM EDT SUN JUN 16 2013
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST MONDAY AND MOVE ACROSS
OUR REGION LATE TUESDAY INTO EARLY WEDNESDAY MORNING.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF 940 PM SUNDAY...
RELATIVELY BENIGN CONVECTION HAS BEEN MOVING WEST TO EAST ACROSS
KY/WV/VA THIS EVENING...WITHIN A ZONE OF PREFRONTAL CONVERGENCE AND
DEEP MOISTURE. FURTHER SOUTH OVER THE LOWER TENNESSEE
VALLEY...WHERE DAYTIME INSTABILITY STILL LINGERS...A MORE WELL
DEFINED CLUSTER OF STORMS IS CURRENTLY MOVING ACROSS NORTHERN GA AND
AND INTO FAR WESTERN NC. THESE TWO AREAS WILL GRADUALLY POSE A
THREAT TO THE NORTHERN AND WESTERN PORTIONS OF CENTRAL NC THROUGH
MONDAY. TONIGHT...FORCING WILL BE WEAK AS THE MOIST/CONVERGENCE
AXIS..WHERE PW VALUES AT 1.5-2"...SLOWLY SHIFTS SOUTHEASTWARD TOWARD
THE AREA. THE AFOREMENTIONED CLUSTER OF STORMS APPROACHING WESTERN
NC SHOULD WEAKEN AS IT ENCOUNTERS MORE HOSTILE AIR EAST OF THE
MOUNTAINS...BUT THE LINGERING OUTFLOW COULD ALSO SERVE AS A CATALYST
FOR SHOWERS IF IT DRIFTS ALL THE WAY INTO THE SOUTHERN/WESTERN
PIEDMONT. BASED ON CURRENT RADAR TRENDS AND LATEST HRRR DATA...HAVE
PUSHED CHANCE POPS BACK UNTIL AFTER 08Z. OTHERWISE...TEMPS WILL
REMAIN RATHER MILD..FALLING INTO THE UPPER 60S AS CLOUDS STEADILY
INCREASE. -BLS
MONDAY...THE MID-LEVEL SHORTWAVE IS FORECAST TO MOVE THROUGH CENTRAL
NORTH CAROLINA...LEAVING SOME SUBSIDENCE IN ITS WAKE LATE IN THE
DAY...MAINLY TOWARD THE TRIAD. THE NAM IS WEAKER WITH ITS
MIXED-LAYER CAPE...500-1000J/KG COMPARED TO THE 1000-1500J/KG OF THE
GFS. BOTH MODELS SHOW ONLY LIMITED DOWNDRAFT CAPE...MAINLY 200J/KG
OR LESS...UNDER WEAK 0-3KM SHEAR IN THE RANGE OF 15KT. 1000-500MB
LAPSE RATES ARE WEAK AS WELL...TO ABOUT 6C/KM BASED ON THE HIGHER
GFS. AS THE DISTURBANCE PASSES THROUGH WITH A WEAK SURFACE TROUGH IN
PLACE...WILL ESSENTIALLY CARRY HIGH CHANCE POPS FOR THE DAY...
CONFINING THOSE POPS MAINLY TO THE AFTERNOON IN THE FAR SOUTHEAST.
ANTICIPATING MORE CLOUDS...HAVE LOWERED MAXES FOR MONDAY TO THE
LOWER TO MID 80S.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
AS OF 250 PM SUNDAY...
MONDAY NIGHT...BOTH THE NAM AND THE GFS FORECAST SOME SUBSIDENCE
BEHIND THE MID-LEVEL SHORTWAVE...PARTICULARLY FROM THE TRIANGLE
NORTHWEST AND NORTH OVERNIGHT. THIS MAY RESULT IN CHANCES FOR
PRECIPITATION BECOMING LIMITED IN THOSE AREAS. FARTHER SOUTH...
HIGHER MOISTURE AND INSTABILITY PERSISTS OVERNIGHT...WITH ANOTHER
MID-LEVEL SHORTWAVE SKIRTING THE AREA TO THE SOUTH. IF THIS
VERIFIES...CHANCES FOR SHOWERS AND ISOLATED THUNDERSTORMS COULD
LINGER INTO THE OVERNIGHT HOURS...ESPECIALLY ACROSS THE SANDHILLS
AND SOUTHERN COASTAL PLAIN. FOR THIS FORECAST...WILL SHOW A
DIMINISHING TREND TO PRECIPITATION CHANCES...ONLY SLIGHT CHANCE IN
THE TRIAD OVERNIGHT WITH CHANCES MAINLY ALONG AND SOUTH OF U.S. 64.
ONCE AGAIN...OVERNIGHT LOWS SHOULD BE WARM...WITHIN A DEGREE OR
THREE OF 70. -DJF
TUESDAY...A DAMPENING MID LEVEL S/W CROSSING CENTRAL NC DURING PRIME
HEATING SHOULD INTERACT WITH THE MOIST AND SLIGHTLY UNSTABLE AIR
MASS IN PLACE TO TRIGGER NUMEROUS-WIDESPREAD SHOWERS AND A FEW
T-STORMS...MAINLY TUESDAY AFTERNOON. LOW LEVEL CONVERGENCE WILL BE
MAXIMIZED ALONG A SWD DRIFTING SFC BOUNDARY WILL LIFT ALOFT A RESULT
OF THE WEAKENING S/W AND 300MB JET CROSSING SOUTHERN NEW ENGLAND
PLACING CENTRAL NC IN THE FAVORABLE RIGHT ENTRANCE REGION. DYNAMICS
NOT OVERLY IMPRESSIVE THOUGH 30KTS OF BULK SHEAR OCCUR IN THE
AFTERNOON ACROSS THE NORTH AND MLCAPE (GFS) REACHES 1000-1400 J/KG
IN THE AFTERNOON. AS ELUDED TO IN PREVIOUS FORECAST...POTENTIAL FOR
SHOWERS/STORMS TO PASS REPEATEDLY OVER THE SAME LOCATION AS MEAN
FLOW PARALLEL TO THE SWD DRIFTING SFC BOUNDARY. THIS MAY LEAD TO
LOCALIZED FLOODING ISSUES...MAINLY IN URBAN AREAS. ANY UPDRAFTS ABLE
TO SUSTAIN MORE THAN 20 MINUTES MAY PRODUCE A WET MICROBURST BUT A
MARGINAL WIND PROFILE AND DEEP MOISTURE (LACK OF DRY AIR
ENTRAINMENT) SUGGEST ANY DAMAGING WINDS WILL BE QUITE ISOLATED.
TUESDAY NIGHT INTO WEDNESDAY...MID LEVEL TROUGH AND ASSOCIATED SFC
BOUNDARY DRIFT SE AND EXIT THE REGION TUESDAY EVENING. THIS SUGGEST
A GRADUAL DIMINISHING IN CONVECTIVE COVERAGE FROM THE NORTH TUESDAY.
ON WEDNESDAY...S/W IN THE ACTIVE NORTHERN STREAM WILL CROSS THE MID
ATLANTIC WEDNESDAY. THIS FEATURE WILL SEND ANOTHER SFC FRONT SWD
ACROSS CENTRAL NC ON WEDNESDAY. WEAK CONVERGENCE ALONG THIS BOUNDARY
COUPLED WITH MODEST UPPER AIR SUPPORT MAY TRIGGER/SUSTAIN
ISOLATED-SCATTERED SHOWERS AND THUNDERSTORMS ON WEDNESDAY. COVERAGE
APPEARS TO BE BETTER SOUTH VERSUS NORTH AS AIR MASS ACROSS THE NORTH
WILL BE DRIER AND MORE STABLE.
HIGH TEMPERATURES TUESDAY DEPENDENT ON CONVECTIVE COVERAGE. IF
WIDESPREAD CONVECTION OCCURS SOONER THAN ANTICIPATED...MAX TEMPS MAY
BE 3-4 DEGREES TOO WARM. A SFC N-NE FLOW WILL SLOWLY ADVECT COOLER
AIR INTO CENTRAL NC WEDNESDAY. LOW LEVEL THICKNESSES SUPPORT MAX
TEMPS NEAR 80-LOWER 80S. -WSS
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 250 PM SUNDAY...
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...SURFACE RIDGE WILL
STRENGTHEN OVER CENTRAL NC. RESULTANT LOW LEVEL NE FLOW WILL
MAINTAIN A RELATIVELY COOL AND STABLE AIR MASS OVER THE BULK OF
CENTRAL NC. THE EXCEPTION WILL BE THE FAR SOUTH AND WEST AS ENOUGH
LIFT/MOISTURE MAY EXIST AROUND THE PERIPHERY OF THE RIDGE TO PERMIT
ISOLATED CONVECTION TO OCCUR. AFTERNOON TEMPS THURSDAY WILL AGAIN
AVERAGE A FEW DEGREES BELOW NORMAL WITH MOST SPOTS IN THE LOWER 80S.
MIN TEMPS BOTH NIGHTS IN THE LOW-MID 60S.
FRI-SUN: MEDIUM RANGE GUIDANCE DIFFER IN THE UPPER AIR PATTERN OVER
THE CAROLINAS AT THE END OF THE WEEK. GFS DEPICTION OF A SERIES OF
S/W CROSSING THE OH VALLEY INTO THE NORTHERN MID ATLANTIC EXTENDING
SWD INTO CENTRAL NC FRI-SAT WOULD SUGGEST A THREAT OF SCATTERED
CONVECTION OVER OUR REGION. MEANWHILE...ECMWF DEPICTS AN ELONGATED
UPPER LEVEL LOW/SHEAR AXIS OFF THE SE U.S. COAST THAT MOVES LITTLE
FRI-SAT. THIS FEATURE ALONG WITH THE MAIN STORM TRACK ACROSS THE
LOWER GREAT LAKES INTO THE NORTHERN MID ATLANTIC PERMITS A NARROW
RIDGE OF HIGH PRESSURE TO EXTEND ACROSS THE CAROLINAS FROM AN
ANTI-CYCLONE POSITIONED OVER THE SOUTHERN PLAINS/LOWER MS VALLEY.
THIS SCENARIO WOULD KEEP CENTRAL NC DRY FRI AND SAT. DIFFICULT TO
SAY AT THIS TIME WHICH SCENARIO MOST LIKELY TO VERIFY AS EACH
SCENARIO HAS AN EQUAL CHANCE TO VERIFY. BY SUNDAY....MODEL CONSENSUS
KEYS ON UPPER RIDGE EXPANDING EWD INTO THE CAROLINAS FROM THE
TN-LOWER OH VALLEY. ANY SHEAR AXES ASSOCIATED WITH CONVECTION
OCCURRING ALONG THE STORM TRACK FROM THE GREAT LAKES INTO THE
NORTHERN MID ATLANTIC WOULD BRUSH OUR FAR NE COUNTIES.
AIR MASS WILL GRADUALLY MODIFY THIS PERIOD WITH AFTERNOON TEMPS
RETURNING TO NEAR OR SLIGHTLY ABOVE NORMAL LEVELS BY SUNDAY.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
AS OF 825 PM SUNDAY...
MID LEVEL RIDGE AXIS (OF HIGH PRESSURE) IS CURRENTLY PUSHING TO THE
EAST OF THE AREA THIS EVENING. MEANWHILE... A WEAK DISTURBANCE IS
EXPECTED TO PUSH INTO THE AREA OVERNIGHT. THIS MAY ALLOW FOR SOME
SHOWERS TO MOVE INTO NORTHWESTERN PORTIONS OF CENTRAL NC VERY LATE
THIS EVENING/EARLY MONDAY MORNING. THUS... HAVE INCLUDED A TEMPO
GROUP FOR SHOWERS AND POSSIBLY MVFR CIGS AND VISBYS IN THE 06-09Z
TIME FRAME AT KGSO AND KINT. ELSEWHERE.... EXPECT VFR CONDITIONS
WILL CONTINUE THROUGH AT LEAST 12Z MONDAY. UNSETTLED WEATHER IS
EXPECTED ON MONDAY. FOR NOW WILL SHOW VFR CONDITIONS AT ALL TAF
SITES OUTSIDE OF THE NORTHWEST (KGSO/KINT)... AS CONFIDENCE IS NOT
HIGH ENOUGH OF SUB-VFR CONDITIONS OUTSIDE OF ANY SCATTERED SHOWERS
AND STORMS. HOWEVER... EXPECT WE MAY HAVE PERIODS OF SHOWERS AND
STORMS MID MORNING THROUGH THE LATE AFTERNOON (WEST)/REST OF THE 00Z
TAF PERIOD (EAST)... AND POSSIBLE MVFR/IFR CONDITIONS ASSOCIATED
WITH THE MOIST CONDITIONS AND WITH SHOWERS AND STORMS.
WE MAY BRIEFLY SEE A PERIOD OF DRY CONDITIONS MONDAY EVENING INTO
EARLY TUESDAY MORNING... BEFORE ADDITIONAL DISTURBANCES MOVE ACROSS
THE AREA ALONG WITH A WEAK COLD FRONT LATE TUESDAY THROUGH
WEDNESDAY. UNTIL THEN EXPECT PERIOD OF SHOWERS AND STORMS... WITH
POSSIBLE SUB-VFR CONDITIONS. VFR CONDITIONS ARE GENERALLY EXPECTED
FROM THURSDAY ONWARD... OUTSIDE OF POSSIBLY SOME EARLY MORNING
STRATUS AND OR FOG DURING THE PRE-DAWN HOURS OF EACH MORNING.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...KMC/DJF
NEAR TERM...DJF/BLS
SHORT TERM...DJF/WSS
LONG TERM...WSS
AVIATION...BSD
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1250 PM CDT SAT JUN 15 2013
.UPDATE...
ISSUED AT 1249 PM CDT SAT JUN 15 2013
ONLY MINOR ADJUSTMENTS AS SHOWERS OVER THE FAR SOUTHEAST PART OF
THE FA ARE PERSISTENT BUT CONTINUE TO WEAKEN. THUS...EXTENDED OUT
THE SHOWERS FOR THE NEXT FEW HOURS IN THAT AREA. OTHERWISE...NO
OTHER CHANGES ARE PLANNED ATTM.
UPDATE ISSUED AT 954 CDT SAT JUN 15 2013
SHOWERS OVER THE FAR SOUTHEAST PART OF THE FA ARE WEAKENING AS THE
UPPER WAVE EXITS. 850MB SFC SHOWS DRIER AIR PUSHING ACROSS THE
AREA FROM THE WEST AND SREF MODEL INDICATES QUIET CONDITIONS THRU
THE REST OF THE DAY. LOW PRESSURE ACROSS SRN SASK IS EXPECTED TO
PUSH EAST INTO MANITOBA LATER THIS EVENING...AND MAY SPREAD SOME
CLOUDINESS AND POSSIBLE A FEW SHOWERS OVER THE FAR NORTH IN THE
EARLY MORNING HOURS SUNDAY SO ADJUSTED FORECAST ACCORDINGLY.
OTHERWISE...REST OF FORECAST LOOKS TO BE ON TARGET.
UPDATE ISSUED AT 636 AM CDT SAT JUN 15 2013
A FEW SHOWERS AND STORMS HAVE GONE UP ALONG THE RIGHT ENTRANCE
REGION OF AN UPPER JET MOVING ACROSS ND. THE ACTIVITY SHOULD MOVE
FROM THE FARGO AREA OUT TOWARDS PARK RAPIDS. NOT MUCH IF ANYTHING
HAS BEEN REACHING THE GROUND...BUT INCLUDED SOME LOW POPS ACROSS
THE SOUTHERN COUNTIES THROUGH 17Z WHICH IS WHEN THE RAP HAS THE
BAND DISSIPATING. ALSO TWEAKED CLOUD COVER FOR A BIT MORE HIGH
CLOUDS MOVING IN WITH THE JET THAN ORIGINALLY EXPECTED.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 324 AM CDT SAT JUN 15 2013
THE MAIN UPPER TROUGH WILL LIFT NORTHEASTWARD INTO CENTRAL CANADA
DURING THE DAY TODAY...LEAVING NEAR ZONAL FLOW OVER THE NORTHERN
PLAINS. CLOUDS WILL CONTINUE TO DECREASE AND WITH WEST WINDS WE
SHOULD STILL GET UP INTO THE MID TO UPPER 70S TODAY EVEN WITH
SLIGHTLY LOWER 850MB TEMPS THAN YESTERDAY. SEVERAL OF THE MODELS
HAVE SOME PRECIP RIGHT ALONG THE CANADIAN BORDER THANKS TO THE
COLD POOL ALOFT. INCLUDED SOME LOW POPS IN THE FAR NORTHERN
COUNTIES FOR THIS AFTERNOON AND EVENING BUT THINK THAT MOST OF THE
ACTIVITY WILL STAY TO OUR NORTH.
CLEAR SKIES AND LIGHT WEST WINDS WILL HELP KEEP LOWS IN THE MID
50S TONIGHT. BY TOMORROW...AN UPPER SHORTWAVE TROUGH WILL BEGIN TO
DIG DOWN FROM CANADA INTO NORTHERN NORTH DAKOTA. A SFC LOW WILL
MOVE OFF INTO NORTHERN MN AND A COLD FRONT WILL BE PUSHING THROUGH
THE CWA. THE SOUTHERN COUNTIES WILL NOT SEE FRONTAL PASSAGE UNTIL
TOWARDS SUNDAY EVENING...SO HIGHS SHOULD AGAIN RISE TO NEAR 80
WHILE THE NORTHWESTERN COUNTIES WILL HAVE MORE PROLONGED COLD AIR
ADVECTION AND WILL ONLY GET INTO THE UPPER 60S. THERE WILL BE SOME
SHOWERS AND THUNDERSTORMS IN THE NORTH BEHIND THE COLD FRONT
MAINLY IN THE AFTERNOON.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 324 AM CDT SAT JUN 15 2013
THE UPPER SHORTWAVE WILL CONTINUE TO DIG INTO MN SUNDAY NIGHT AND
A COLD FRONT WILL PUSH THE REST OF THE WAY THROUGH THE CWA.
NORTHWESTERLY FLOW ALOFT AND SFC HIGH PRESSURE WILL KEEP THINGS A
BIT COOLER THAN AVERAGE ON MONDAY WITH HIGHS ONLY TOPPING OUT IN
THE 70S. WITH THE COLD AIR ALOFT...CONVECTIVE TEMPS WILL BE FAIRLY
EASY TO REACH SO THERE SHOULD BE SOME SHOWER REDEVELOPMENT BY
MONDAY AFTERNOON. THE SHOWERS SHOULD QUICKLY DISSIPATE AFTER
SUNSET AND MONDAY NIGHT WILL BE DRY.
TUESDAY TO FRIDAY...A DIFFICULT POP FORECAST FOR MUCH OF THE TIME
FRAME AS THE AREA WILL BE ON THE NORTHERN PERIPHERY OF CENTRAL
PLAINS 500MB RIDGE AND/OR STILL UNDER THE INFLUENCE OF 500MB NW
FLOW. DRY WEATHER FROM SFC HIGH ON TUESDAY WILL GIVE WAY TO SHOWER
CHANCES AS WEAK ENERGY COMBINES WITH INCREASING MOISTURE AVAILABLE
UNDER THE SLOWLY NORTHWARD ADVECTING CENTRAL PLAINS AIRMASS.
INCREASING MOISTURE AND INSTABILITY WILL INTERACT WITH IMPULSES IN
THE GENERAL FLOW EITHER ORIGINATING FROM THE CANADIAN PRAIRIES IN
THE NW FLOW OR FROM SHORT WAVES FEATURES ROLLING OVER TOP THE RIDGE.
EITHER WAY EXPECTING SEASON TEMPERATURES AND WEAK CHCS FOR
CONVECTION FOR MUCH OF THE LATTER HALF OF NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1249 PM CDT SAT JUN 15 2013
VFR CONDITIONS THROUGH THE PERIOD. WILL SEE SOME HIGH BASED SCT-
BKN CU DEVELOPMENT MAINLY ACROSS THE NORTHERN FORECAST AREA THIS
AFTERNOON CLEARING THIS EVENING WITH LOSS OF HEATING. GUSTY WEST
WINDS WILL BE CONFINED TO AREAS WEST OF THE VALLEY. THESE TOO WILL
DIMINISH THIS EVENING.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...HOPKINS
SHORT TERM...JR
LONG TERM...JR/JK
AVIATION...VOELKER
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
954 AM CDT SAT JUN 15 2013
.UPDATE...
ISSUED AT 954 CDT SAT JUN 15 2013
SHOWERS OVER THE FAR SOUTHEAST PART OF THE FA ARE WEAKENING AS THE
UPPER WAVE EXITS. 850MB SFC SHOWS DRIER AIR PUSHING ACROSS THE
AREA FROM THE WEST AND SREF MODEL INDICATES QUIET CONDITIONS THRU
THE REST OF THE DAY. LOW PRESSURE ACROSS SRN SASK IS EXPECTED TO
PUSH EAST INTO MANITOBA LATER THIS EVENING...AND MAY SPREAD SOME
CLOUDINESS AND POSSIBLE A FEW SHOWERS OVER THE FAR NORTH IN THE
EARLY MORNING HOURS SUNDAY SO ADJUSTED FORECAST ACCORDINGLY.
OTHERWISE...REST OF FORECAST LOOKS TO BE ON TARGET.
UPDATE ISSUED AT 636 AM CDT SAT JUN 15 2013
A FEW SHOWERS AND STORMS HAVE GONE UP ALONG THE RIGHT ENTRANCE
REGION OF AN UPPER JET MOVING ACROSS ND. THE ACTIVITY SHOULD MOVE
FROM THE FARGO AREA OUT TOWARDS PARK RAPIDS. NOT MUCH IF ANYTHING
HAS BEEN REACHING THE GROUND...BUT INCLUDED SOME LOW POPS ACROSS
THE SOUTHERN COUNTIES THROUGH 17Z WHICH IS WHEN THE RAP HAS THE
BAND DISSIPATING. ALSO TWEAKED CLOUD COVER FOR A BIT MORE HIGH
CLOUDS MOVING IN WITH THE JET THAN ORIGINALLY EXPECTED.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 324 AM CDT SAT JUN 15 2013
THE MAIN UPPER TROUGH WILL LIFT NORTHEASTWARD INTO CENTRAL CANADA
DURING THE DAY TODAY...LEAVING NEAR ZONAL FLOW OVER THE NORTHERN
PLAINS. CLOUDS WILL CONTINUE TO DECREASE AND WITH WEST WINDS WE
SHOULD STILL GET UP INTO THE MID TO UPPER 70S TODAY EVEN WITH
SLIGHTLY LOWER 850MB TEMPS THAN YESTERDAY. SEVERAL OF THE MODELS
HAVE SOME PRECIP RIGHT ALONG THE CANADIAN BORDER THANKS TO THE
COLD POOL ALOFT. INCLUDED SOME LOW POPS IN THE FAR NORTHERN
COUNTIES FOR THIS AFTERNOON AND EVENING BUT THINK THAT MOST OF THE
ACTIVITY WILL STAY TO OUR NORTH.
CLEAR SKIES AND LIGHT WEST WINDS WILL HELP KEEP LOWS IN THE MID
50S TONIGHT. BY TOMORROW...AN UPPER SHORTWAVE TROUGH WILL BEGIN TO
DIG DOWN FROM CANADA INTO NORTHERN NORTH DAKOTA. A SFC LOW WILL
MOVE OFF INTO NORTHERN MN AND A COLD FRONT WILL BE PUSHING THROUGH
THE CWA. THE SOUTHERN COUNTIES WILL NOT SEE FRONTAL PASSAGE UNTIL
TOWARDS SUNDAY EVENING...SO HIGHS SHOULD AGAIN RISE TO NEAR 80
WHILE THE NORTHWESTERN COUNTIES WILL HAVE MORE PROLONGED COLD AIR
ADVECTION AND WILL ONLY GET INTO THE UPPER 60S. THERE WILL BE SOME
SHOWERS AND THUNDERSTORMS IN THE NORTH BEHIND THE COLD FRONT
MAINLY IN THE AFTERNOON.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 324 AM CDT SAT JUN 15 2013
THE UPPER SHORTWAVE WILL CONTINUE TO DIG INTO MN SUNDAY NIGHT AND
A COLD FRONT WILL PUSH THE REST OF THE WAY THROUGH THE CWA.
NORTHWESTERLY FLOW ALOFT AND SFC HIGH PRESSURE WILL KEEP THINGS A
BIT COOLER THAN AVERAGE ON MONDAY WITH HIGHS ONLY TOPPING OUT IN
THE 70S. WITH THE COLD AIR ALOFT...CONVECTIVE TEMPS WILL BE FAIRLY
EASY TO REACH SO THERE SHOULD BE SOME SHOWER REDEVELOPMENT BY
MONDAY AFTERNOON. THE SHOWERS SHOULD QUICKLY DISSIPATE AFTER
SUNSET AND MONDAY NIGHT WILL BE DRY.
TUESDAY TO FRIDAY...A DIFFICULT POP FORECAST FOR MUCH OF THE TIME
FRAME AS THE AREA WILL BE ON THE NORTHERN PERIPHERY OF CENTRAL
PLAINS 500MB RIDGE AND/OR STILL UNDER THE INFLUENCE OF 500MB NW
FLOW. DRY WEATHER FROM SFC HIGH ON TUESDAY WILL GIVE WAY TO SHOWER
CHANCES AS WEAK ENERGY COMBINES WITH INCREASING MOISTURE AVAILABLE
UNDER THE SLOWLY NORTHWARD ADVECTING CENTRAL PLAINS AIRMASS.
INCREASING MOISTURE AND INSTABILITY WILL INTERACT WITH IMPULSES IN
THE GENERAL FLOW EITHER ORIGINATING FROM THE CANADIAN PRAIRIES IN
THE NW FLOW OR FROM SHORT WAVES FEATURES ROLLING OVER TOP THE RIDGE.
EITHER WAY EXPECTING SEASON TEMPERATURES AND WEAK CHCS FOR
CONVECTION FOR MUCH OF THE LATTER HALF OF NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 636 AM CDT SAT JUN 15 2013
CONDITIONS WILL REMAIN VFR THROUGHOUT THE PERIOD WITH ONLY HIGH
AND A FEW MID LEVEL CLOUDS. THE MAIN CONCERN WILL BE WINDS. WEST
WINDS WILL PICK UP BY LATE MORNING TO EARLY AFTERNOON INTO THE 15
TO 20 KT RANGE WITH GUSTS TO AROUND 25 KTS IN SOME PLACES. WINDS
WILL DIMINISH BY EVENING.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...HOPKINS
SHORT TERM...JR
LONG TERM...JR/JK
AVIATION...JR
AREA FORECAST DISCUSSION
NWS BISMARCK ND
105 AM CDT SAT JUN 15 2013
.UPDATE...
ISSUED AT 105 AM CDT SAT JUN 15 2013
WATER VAPOR IMAGERY SHOWS CLOSED STATIONARY LOW OVER CENTRAL
SASKATCHEWAN WITH SURFACE HIGH BUILDING IN ACROSS NORTH DAKOTA
BEHIND COLD FRONT CURRENTLY CROSSING MINNESOTA. DRY CONDITIONS WILL
PREVAIL OVERNIGHT AND SATURDAY UNDER MOSTLY CLEAR SKIES.
TEMPERATURES WERE DROPPING A LITTLE FASTER THAN THE FORECAST
ACCOUNTED FOR SO THAT WAS THE MAIN UPDATE CHANGE. OTHERWISE THE
FORECAST REMAINS ON TRACK. EXPECT BREEZY CONDITIONS TO DEVELOP
DURING THE MORNING WITH GUSTY WEST WINDS. MODELS CONTINUE TO
INDICATE INSTABILITY SATURDAY AFTERNOON MAINLY ACROSS NORTH
CENTRAL NORTH DAKOTA. WILL MOSTLY LIKELY MAINTAIN LOW POPS ACROSS
THIS REGION WITH THE NEXT UPDATE AS WELL WITH FORECAST SOUNDINGS
FROM GFS/NAM BOTH SUPPORTING THE CHANCE OF SHOWERS AND POSSIBLY A
THUNDERSTORM CLOSE TO CANADIAN BORDER.
UPDATE ISSUED AT 948 PM CDT FRI JUN 14 2013
REMOVED ALL PRECIPITATION MENTION FOR THE REST OF TONIGHT. A FEW
SHOWERS/ISOLATED THUNDERSTORMS TRACKING EAST ALONG THE
INTERNATIONAL BORDER ACROSS FAR NORTHEAST MONTANA. DOUBTFUL THESE
SHOWERS/STORMS WILL MAKE IT INTO NORTHWEST ND SO KEPT THE FORECAST
DRY. OTHER UPDATES MINOR AT BEST.
UPDATE ISSUED AT 715 PM CDT FRI JUN 14 2013
SURFACE TROUGH IS NOW EXITING OUR FORECAST AREA AND NO LONGER
EXPECT ANY CONVECTION THROUGH THE REMAINDER OF TONIGHT OVER MY
EAST. THUS LOWERED POPS THERE AND WILL MAINTAIN DRY CONDITIONS
MOST OTHER LOCATIONS. SCATTERED SHOWERS/THUNDERSTORMS OVER
NORTHEAST MONTANA CONTINUE TO TRACK EAST TOWARDS NORTHWEST NORTH
DAKOTA BEHIND A STRONG S/WV IMPULSE NOW OVER SOUTH CENTRAL CANADA.
EXPECT THIS TO BE MAINLY DIURNAL SO WILL KEEP SCATTERED
THUNDERSTORMS UNTIL 03Z THEN GO DRY FOR THE REST OF THE PERIOD.
OTHER FORECAST ELEMENTS ON TRACK WITH ONLY MINIMAL CHANGES WITH
THIS UPDATE.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 257 PM CDT FRI JUN 14 2013
MAIN CONCERN FOR THE SHORT TERM WILL BE THUNDERSTORMS ACROSS THE
NORTHWEST THIS EVENING. SATELLITE AND THE RAP MODEL SHOW A MID
LEVEL IMPULSE THAT WILL TRACK THROUGH NORTHEAST MONTANA INTO
NORTHWEST NORTH DAKOTA THIS EVENING. WILL ADD A CHANCE FOR
THUNDERSTORMS FOR THE EVENING HOURS. TO THE EAST...A COLD FRONT
WAS MAKING ITS WAY ACROSS CENTRAL NORTH DAKOTA. STILL BELIEVE
THERE WILL BE A CHANCE FOR CONVECTIVE INITIATION ACROSS THE EAST
CENTRAL TONIGHT. AFTER SUNRISE SATURDAY...BELIEVE ITS REASONABLE
FOR ALL THE PRECIPITATION TO BE NORTH AND EAST OF THE REGION .
WILL GO DRY FOR SATURDAY IN GENERAL SUBSIDENCE ON THE SOUTH AND
WEST SIDE OF THE UPPER LOW WHICH WILL BE IN CANADA.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 257 PM CDT FRI JUN 14 2013
NO SIGNIFICANT WEATHER TO HIGHLIGHT THE EXTENDED FORECAST WITH
BELOW NORMAL TEMPERATURES SUNDAY AND MONDAY TRANSITIONING TO NEAR
NORMAL VALUES THROUGH THE REMAINDER OF NEXT WEEK.
THE 12 UTC GUIDANCE SUITE IS IN GOOD AGREEMENT THROUGH WEDNESDAY
WITH A DIVERGENCE IN SOLUTIONS THURSDAY INTO FRIDAY. FOR
SUNDAY...A FILLING UPPER LEVEL LOW PROPAGATES SOUTHEAST OUT OF
CANADA WHICH SUPPORTS DIURNALLY DRIVEN ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS UNDER THE COLD CORE ALOFT. COOL HIGH
PRESSURE IN THE WAKE OF THIS SYSTEM FOR MONDAY SUGGESTS WIDESPREAD
HIGHS IN THE UPPER 60S AND LOWER 70S...ABOUT 7 TO 10 DEGREES BELOW
NORMAL. THEREAFTER...UPPER LEVEL RIDGING BUILDS ACROSS THE
NORTHERN PLAINS WITH A RETURN TO NORMAL HIGHS NEAR 80. UNCERTAINTY
INCREASES FOR CONVECTIVE CHANCES THURSDAY THROUGH FRIDAY IN REGARDS
TO THE PROPAGATION AND EVOLUTION OF THE UPPER LEVEL LOW COMING ON
SHORE TO THE PACIFIC NORTHWEST ON WEDNESDAY...AND HOW FAR EAST THE
LOW CAN PROPAGATE TO TURN TO THE UPPER LEVEL FLOW TO THE SOUTHWEST
ACROSS THE NORTHERN PLAINS. OVERALL...A BLEND OF THE 12 UTC
GUIDANCE SUITE WAS USED FOR MOST FIELDS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 105 AM CDT SAT JUN 15 2013
VFR CONDITIONS EXPECTED THROUGH THE PERIOD AT ALL SITES AS SURFACE
HIGH PRESSURE STRENGTHENS ACROSS THE STATE. WINDS WILL INCREASE
OUT OF THE WEST THIS MORNING AT ALL SITES GENERALLY 20 KTS GUSTING
TO 30 KTS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JNS
SHORT TERM...WAA
LONG TERM...AYD
AVIATION...JNS
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
210 PM EDT SAT JUN 15 2013
.SYNOPSIS...
HIGH PRESSURE NOW OVER THE AREA WILL MOVE SOUTHEAST OFF THE
CAROLINA COAST BY THIS EVENING. LOW PRESSURE WILL DEVELOP AND MOVE
ACROSS THE CENTRAL GREAT LAKES ON SUNDAY. ANOTHER LOW OVER
CENTRAL CANADA WILL DROP ACROSS THE CENTRAL GREAT LAKES MONDAY AND
DRAG A COLD FRONT ACROSS THE REGION. HIGH PRESSURE WILL BUILD IN
BY THE MIDDLE OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MINOR ADJUSTMENTS TO THE FORECAST. THE CLOUDS APPROACHING FROM THE
WEST SHOULD DISSIPATE AND THIN FOR THE NEXT HOURS. STILL THINK IT
WILL BECOME MOSTLY CLOUDY TOWARDS EVENING. SHOWERS APPROACHING
FROM THE WEST ARE ALSO HAVING A TOUGH TIME. LATEST HRRR CONTINUES
TO SHOW MORE PRECIP ARRIVING LATE IN THE DAY SO WILL LEAVE CHANCES
IN THE FORECAST.
UPDATE...WHILE MOST OF THE AREA SHOULD HAVE THIN/VARIABLE
CIRRUS...THICKER CLOUDS ARE ABOUT TO MOVE INTO NWRN OHIO FROM THE
DYING MCS TO OUR WEST. DIURNALLY...THESE CLOUDS SHOULD THIN INTO THE
AFTERNOON AS THE PARENT MCS DISSIPATES SO FOR THE GRAPHICS...WILL
BRING BKN CLOUDS INTO NWRN OHIO THIS MORNING AND THEN THIN THEM A
BIT FOR MID DAY BEFORE INCREASING AGAIN LATE THIS AFTERNOON. WILL
CONTINUE WITH PARTLY SUNNY TO PARTLY CLOUDY ELSEWHERE. NO OTHER
CHANGES.
HIGH PRESSURE ACROSS THE AREA AND SKIES ARE CLEAR HOWEVER MCS
FROM NRN MO ACROSS IA INTO WI WILL EVENTUALLY MOVE OVER THE WEAK
UPPER RIDGE AXIS AND BEGIN TO MOVE INTO THE OHIO VALLEY. FOLLOWING
THE HEIGHTS AND THICKNESS...MUCH WILL MOVE TO OUR SOUTH HOWEVER CI
OVER WI AND CENTRAL LK MI SHOULD DROP ACROSS THE AREA. CLOUDS
SHOULD BE THINNING AS THEY MOVE INTO THE OHIO VALLEY. DID INCREASE
CLOUDS IN THE WESTERN GROUPS TO MOSTLY CLOUDY BY AFTERNOON.
ELSEWHERE EXPECTING VEILED SUNSHINE BUT WORDING WILL LIKELY BE
PARTLY SUNNY TO PARTLY CLOUDY. FOR THE FAR NW BROUGHT CHANCE POPS
TO THE REGION BY MID/LATE AFTERNOON. GIVEN THE ANTICIPATED CLOUDS
SHAVED A DEGREE OR TWO OFF GUIDANCE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
THIS EVENING THE HIGH WILL MOVE OFF THE CAROLINA COAST AND ALLOW A
DEVELOPING LOW TO MOVE ACROSS THE CENTRAL GREAT LAKES EARLY
TONIGHT. MODELS ALSO SHOW A SHORT WAVES MOVING THROUGH IN THE
FLATTENING UPPER LOW AND INCREASING MOISTURE. WILL HAVE POPS
INCREASING FROM THE NORTHWEST OVERNIGHT TO LIKELY WEST OF ROUGHLY A
ERI-CLE-MFD LINE. EARLY SUNDAY WILL HAVE LIKELY POPS SHIFT TO THE
EAST FOR THE MORNING AND THEN DECREASE TO CHANCE IN THE AFTERNOON
AS THE SYSTEM MOVES EAST. MONDAY ANOTHER LOW WILL DROP ACROSS THE
CENTRAL LAKES FROM CANADA. THIS SECOND LOW WILL DRIVE A COLD
FRONT ACROSS THE AREA LATE MONDAY OR MONDAY NIGHT BRINGING ANOTHER
SHOT OF SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL BUILD IN
TUESDAY AFTERNOON. TOWARD THE END OF THE SHORT TERM PERIOD
SHIFTED FROM THE NAM TO THE ECMWF WHICH WAS MUCH DRIER ON TUESDAY
VS THE GFS WHICH APPEARS TO SUFFER FROM CONVECTIVE FEEDBACK
DEVELOPING AN UPPER LOW AND A RATHER WOUND UP SURFACE LOW IN THE
LOWER OHIO VALLEY WHILE THE ECMWF IS MUCH WEAKER WITH THE
FEATURES. HIGH TEMPS NEAR NORMAL TODAY AND SUNDAY AND A COUPLE
DEGREES ABOVE NORMAL MONDAY. TUESDAY TEMPS WILL DROP BACK TO BELOW
NORMAL BY A FEW DEGREES POST COLD FRONT.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
THE BIG PICTURE HAS A RIDGE AXIS UP INTO THE DAKOTAS AND A TROUGH
ACROSS THE GREAT LAKES AND NEW ENGLAND. WITH TIME DURING THE SECOND
HALF OF THE WEEK...THAT RIDGE WILL SHIFT EAST...BUT AT THE SAME TIME
WEAKEN/FLATTEN LEAVING MORE ZONAL FLOW ACROSS THE LOCAL AREA GOING
INTO THE WEEKEND. THEREFORE HIGH PRESSURE WILL BE IN PLACE
WEDNESDAY...AND LIKELY LINGER INTO THURSDAY. TEMPERATURES WILL BE
SLIGHTLY BELOW NORMAL...BUT STILL SEASONABLE. BY FRIDAY MOISTURE
BEGINS TO INCREASE AND THE NEXT SYSTEM WILL BE MAKING ITS WAY TO THE
CENTRAL GREAT LAKES. WILL WARM TO NEAR 80 AGAIN. WILL LEAVE THE LONG
TERM DRY FOR NOW.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
CLOUDS AND SHOWERS APPROACHING FROM THE WEST ACROSS INDIANA WILL
APPROACH TOL/FDY BY 22Z ALTHOUGH SHOWERS ARE EXPECTED TO BECOME MORE
SCATTERED AS THEY CONTINUE EASTWARD INTO THE DRIER AIR. THE NEXT
ROUND OF SHOWERS AND THUNDERSTORMS DEVELOPING BACK TO THE WEST
ACROSS ILLINOIS/IOWA ARE EXPECTED TO MOVE ACROSS NORTHERN OHIO
WITH SUPPORT FROM A WEAK LOW LEVEL JET DURING THE OVERNIGHT HOURS.
SOME UNCERTAINTY EXISTS IN THE TRAJECTORY OF THE NEXT ROUND BUT
CONFIDENCE WAS HIGH ENOUGH TO INTRODUCE A TEMPO WITH THUNDERSTORMS
BETWEEN 02-07Z AT TOL/FDY/MFD. WILL WAIT TO ADD MORE THAN A VCTS
TO THE OTHER SITES UNTIL TIMING AND EVOLUTION BECOMES A LITTLE
MORE CLEAR. EXPECTING VFR TO CONTINUE UNTIL ANY HEAVIER SHOWERS
ARRIVE TONIGHT WITH MVFR CEILINGS POSSIBLE BEHIND THE RAIN LATE
TONIGHT. SOUTHERLY WINDS WILL SHIFT TO THE WEST BEHIND THE COMPLEX
ON SUNDAY.
.OUTLOOK...NON VFR POSSIBLE TONIGHT THROUGH MONDAY IN SHOWERS AND
THUNDERSTORMS. NON VFR CEILINGS MAY LINGER INTO TUESDAY.
&&
.MARINE...
HIGH PRESSURE OVERHEAD TODAY AND THE LAKE WILL BE QUIET. LATE
TONIGHT GOING INTO SUNDAY MORNING SOUTHWEST WINDS WILL INCREASE TO
10 TO 20 KNOTS AHEAD OF A COLD FRONT FOR LATER ON SUNDAY. THIS WILL
MAKE THE OFFSHORE WATERS AND THE EAST NEARSHORE WATERS CHOPPY TO
START THE DAY. FOR NOW WILL KEEP CONDITIONS BELOW SMALL CRAFT
CRITERIA. WINDS/WAVES SETTLE SUNDAY EVENING. IN GENERAL LIGHT AND
VARIABLE FLOW EARLY NEXT WORK WEEK...BUT THERE ARE DECENT DIFFERENCE
IN TIMING OF THE NEXT SYSTEM/S/...AND THOSE DETAILS WILL HAVE AN
EFFECT ON WIND DIRECTION.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TK
NEAR TERM...TK/KUBINA
SHORT TERM...TK
LONG TERM...OUDEMAN
AVIATION...KEC
MARINE...OUDEMAN
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1003 AM EDT SAT JUN 15 2013
.SYNOPSIS...
HIGH PRESSURE NOW OVER THE AREA WILL MOVE SOUTHEAST OFF THE
CAROLINA COAST BY THIS EVENING. LOW PRESSURE WILL DEVELOP AND MOVE
ACROSS THE CENTRAL GREAT LAKES ON SUNDAY. ANOTHER LOW OVER
CENTRAL CANADA WILL DROP ACROSS THE CENTRAL GREAT LAKES MONDAY AND
DRAG A COLD FRONT ACROSS THE REGION. HIGH PRESSURE WILL BUILD IN
BY THE MIDDLE OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MINOR ADJUSTMENTS TO THE FORECAST. THE CLOUDS APPROACHING FROM THE
WEST SHOULD DISSIPATE AND THIN FOR THE NEXT HOURS. STILL THINK IT
WILL BECOME MOSTLY CLOUDY TOWARDS EVENING. SHOWERS APPROACHING
FROM THE WEST ARE ALSO HAVING A TOUGH TIME. LATEST HRRR CONTINUES
TO SHOW MORE PRECIP ARRIVING LATE IN THE DAY SO WILL LEAVE CHANCES
IN THE FORECAST.
UPDATE...WHILE MOST OF THE AREA SHOULD HAVE THIN/VARIABLE
CIRRUS...THICKER CLOUDS ARE ABOUT TO MOVE INTO NWRN OHIO FROM THE
DYING MCS TO OUR WEST. DIURNALLY...THESE CLOUDS SHOULD THIN INTO THE
AFTERNOON AS THE PARENT MCS DISSIPATES SO FOR THE GRAPHICS...WILL
BRING BKN CLOUDS INTO NWRN OHIO THIS MORNING AND THEN THIN THEM A
BIT FOR MID DAY BEFORE INCREASING AGAIN LATE THIS AFTERNOON. WILL
CONTINUE WITH PARTLY SUNNY TO PARTLY CLOUDY ELSEWHERE. NO OTHER
CHANGES.
HIGH PRESSURE ACROSS THE AREA AND SKIES ARE CLEAR HOWEVER MCS
FROM NRN MO ACROSS IA INTO WI WILL EVENTUALLY MOVE OVER THE WEAK
UPPER RIDGE AXIS AND BEGIN TO MOVE INTO THE OHIO VALLEY. FOLLOWING
THE HEIGHTS AND THICKNESS...MUCH WILL MOVE TO OUR SOUTH HOWEVER CI
OVER WI AND CENTRAL LK MI SHOULD DROP ACROSS THE AREA. CLOUDS
SHOULD BE THINNING AS THEY MOVE INTO THE OHIO VALLEY. DID INCREASE
CLOUDS IN THE WESTERN GROUPS TO MOSTLY CLOUDY BY AFTERNOON.
ELSEWHERE EXPECTING VEILED SUNSHINE BUT WORDING WILL LIKELY BE
PARTLY SUNNY TO PARTLY CLOUDY. FOR THE FAR NW BROUGHT CHANCE POPS
TO THE REGION BY MID/LATE AFTERNOON. GIVEN THE ANTICIPATED CLOUDS
SHAVED A DEGREE OR TWO OFF GUIDANCE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
THIS EVENING THE HIGH WILL MOVE OFF THE CAROLINA COAST AND ALLOW A
DEVELOPING LOW TO MOVE ACROSS THE CENTRAL GREAT LAKES EARLY
TONIGHT. MODELS ALSO SHOW A SHORT WAVES MOVING THROUGH IN THE
FLATTENING UPPER LOW AND INCREASING MOISTURE. WILL HAVE POPS
INCREASING FROM THE NORTHWEST OVERNIGHT TO LIKELY WEST OF ROUGHLY A
ERI-CLE-MFD LINE. EARLY SUNDAY WILL HAVE LIKELY POPS SHIFT TO THE
EAST FOR THE MORNING AND THEN DECREASE TO CHANCE IN THE AFTERNOON
AS THE SYSTEM MOVES EAST. MONDAY ANOTHER LOW WILL DROP ACROSS THE
CENTRAL LAKES FROM CANADA. THIS SECOND LOW WILL DRIVE A COLD
FRONT ACROSS THE AREA LATE MONDAY OR MONDAY NIGHT BRINGING ANOTHER
SHOT OF SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL BUILD IN
TUESDAY AFTERNOON. TOWARD THE END OF THE SHORT TERM PERIOD
SHIFTED FROM THE NAM TO THE ECMWF WHICH WAS MUCH DRIER ON TUESDAY
VS THE GFS WHICH APPEARS TO SUFFER FROM CONVECTIVE FEEDBACK
DEVELOPING AN UPPER LOW AND A RATHER WOUND UP SURFACE LOW IN THE
LOWER OHIO VALLEY WHILE THE ECMWF IS MUCH WEAKER WITH THE
FEATURES. HIGH TEMPS NEAR NORMAL TODAY AND SUNDAY AND A COUPLE
DEGREES ABOVE NORMAL MONDAY. TUESDAY TEMPS WILL DROP BACK TO BELOW
NORMAL BY A FEW DEGREES POST COLD FRONT.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
THE BIG PICTURE HAS A RIDGE AXIS UP INTO THE DAKOTAS AND A TROUGH
ACROSS THE GREAT LAKES AND NEW ENGLAND. WITH TIME DURING THE SECOND
HALF OF THE WEEK...THAT RIDGE WILL SHIFT EAST...BUT AT THE SAME TIME
WEAKEN/FLATTEN LEAVING MORE ZONAL FLOW ACROSS THE LOCAL AREA GOING
INTO THE WEEKEND. THEREFORE HIGH PRESSURE WILL BE IN PLACE
WEDNESDAY...AND LIKELY LINGER INTO THURSDAY. TEMPERATURES WILL BE
SLIGHTLY BELOW NORMAL...BUT STILL SEASONABLE. BY FRIDAY MOISTURE
BEGINS TO INCREASE AND THE NEXT SYSTEM WILL BE MAKING ITS WAY TO THE
CENTRAL GREAT LAKES. WILL WARM TO NEAR 80 AGAIN. WILL LEAVE THE LONG
TERM DRY FOR NOW.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
VEIL OF CIRRUS WILL OVERSPREAD THE AREA TODAY. SIGNIFICANT AVIATION
WEATHER WILL TAKE PLACE FROM THIS EVENING AND INTO SUNDAY MORNING
WITH THE ARRIVAL OF SHOWERS AND THUNDERSTORMS. UNCERTAIN TO EXACT
ARRIVAL TIME AND HAVE A PROB30 FOR THIS. MORE CERTAINTY IN
PRECIP EXISTS FOR THE EARLY MORNING HOURS OF SUNDAY...AND ALL TAF
SITES WILL LIKELY SEE RAIN BY ABOUT 12Z SUN. NON-VFR IN THE TS.
SOUTH- SOUTHWEST FLOW WILL CONTINUE.
.OUTLOOK...NON VFR POSSIBLE TONIGHT THROUGH MONDAY IN SHOWERS AND
THUNDERSTORMS. NON VFR CEILINGS MAY LINGER INTO TUESDAY.
&&
.MARINE...
HIGH PRESSURE OVERHEAD TODAY AND THE LAKE WILL BE QUIET. LATE
TONIGHT GOING INTO SUNDAY MORNING SOUTHWEST WINDS WILL INCREASE TO
10 TO 20 KNOTS AHEAD OF A COLD FRONT FOR LATER ON SUNDAY. THIS WILL
MAKE THE OFFSHORE WATERS AND THE EAST NEARSHORE WATERS CHOPPY TO
START THE DAY. FOR NOW WILL KEEP CONDITIONS BELOW SMALL CRAFT
CRITERIA. WINDS/WAVES SETTLE SUNDAY EVENING. IN GENERAL LIGHT AND
VARIABLE FLOW EARLY NEXT WORK WEEK...BUT THERE ARE DECENT DIFFERENCE
IN TIMING OF THE NEXT SYSTEM/S/...AND THOSE DETAILS WILL HAVE AN
EFFECT ON WIND DIRECTION.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TK
NEAR TERM...TK/KUBINA
SHORT TERM...TK
LONG TERM...OUDEMAN
AVIATION...OUDEMAN
MARINE...OUDEMAN
AREA FORECAST DISCUSSION
NWS MEDFORD OR
319 AM PDT SAT JUN 15 2013
.SYNOPSIS...A BROAD UPPER LEVEL LOW PRESSURE SYSTEM OVER THE
NORTHEAST PACIFIC WILL PUSH SLOWLY INTO THE PACIFIC NORTHWEST
OVER THE NEXT SEVERAL DAYS. THIS WILL PRODUCE A COOLING TREND WITH
AN INCREASE IN AFTERNOON AND EVENING BREEZINESS. IN ADDITION...THE
LOW WILL BRING INCREASED CLOUDINESS AND SLIGHT CHANCE TO CHANCE
PROBABILITIES FOR SHOWERS AND SOME THUNDERSTORMS. THE HIGHER
THREAT WILL BE OVER THE SOUTHERN OREGON CASCADES AND PORTIONS OF
SOUTH-CENTRAL OREGON. HIGH TEMPERATURES ACROSS THE REGION SHOULD
FALL 10 TO 15 DEGREES BELOW NORMAL BY MID WEEK.
.DISCUSSION...MAIN FORECAST CHALLENGE THIS CYCLE IS POPS FOR
SHOWERS AND THUNDERSTORMS TODAY AND SUNDAY. THE BROAD UPPER LOW
OFF THE COAST WILL BE SLOW TO MOVE INLAND OVER THE REGION. MODELS
ARE IN FAIRLY GOOD AGREEMENT WITH PROGRESSING IT FROM THE CURRENT
POSITION NEAR 50N/135W INLAND OVER OREGON TUESDAY INTO WEDNESDAY.
THE EC IS CURRENTLY THE WETTER SOLUTION TUESDAY AND WEDNESDAY.
IN THE NEAR TERM...COORDINATED IN LAST EVENING`S UPDATE WITH
INCREASING THE THUNDER CHANCE JUST A BIT TODAY AND REFINING THE
AREA TO THE TRINITIES NORTHWARD TO AROUND AND NORTHEAST OF CRATER
LAKE. WEAK SHORT WAVE ENERGY COMING UP FROM OFF OF NORTHERN
CALIFORNIA SHOULD PROVIDE A MARGINAL TRIGGER TO INTERACT WITH
DESTABILIZATION AND SURFACE CONVERGENCE OVER MAINLY THE HIGHER
TERRAIN OF THE CASCADES AND SISKIYOUS. AREAS EAST OF THE CASCADES
ARE IN MODERATE FIRE DANGER SO THE MAIN AREA TO BEWARE FOR
LIGHTNING TODAY IS CENTRAL SISKIYOU COUNTY WHERE FIRE DANGER IS
HIGH. WE HAVE ABOVE AVERAGE CONFIDENCE THAT STRIKE COVERAGE THERE
WILL REMAIN BELOW RED FLAG LEVELS.
OVERALL THREAT LOOKS MINIMAL OVER THE WEST SIDE WITH A MODERATE
CAP AND INCREASING AFTERNOON ONSHORE GRADIENT KEEPING IT STABLE.
NOT OUT OF THE QUESTION THAT SOMETHING COULD SNEAK INTO CENTRAL
JACKSON COUNTY BUT UNLIKELY.
FOR SUNDAY...WE HAVE TAPERED BACK PROBABILITIES FOR PRECIP OVER
THE WEST SIDE AND NUDGED THE AFTERNOON AND EVENING THUNDER THREAT
JUST A BIT EASTWARD. OVERALL MODEL CONSENSUS KEEPS THE MAJORITY
OF THE FORECAST AREA DRY THIS WEEKEND...BUT CONFIDENCE IN SOME
STORM DEVELOPMENT OVER THE MENTIONED AREAS IS HIGH.
00Z NAM12 AND GFS ADVERTISE MONDAY CONSIDERABLY DRIER THAN GOING
FORECAST. SCALED BACK JUST A BIT BUT MAINTAINED THE WETTER EC-
LIKE FORECAST LATER MONDAY THROUGH WEDNESDAY. LOW CONFIDENCE ON
RAIN AMOUNTS MONDAY AFTERNOON/NIGHT INLAND FROM THE COAST.
&&
.AVIATION...LATEST HIGH-RESOLUTION RAP MODEL DATA SUGGESTS THE
MARINE LAYER AND LIKELY MVFR CEILINGS WILL AFFECT THE COAST...MOST
LIKELY ALONG AND NORTH OF CAPE BLANCO...BY AROUND 02Z WITH OTHER
GUIDANCE SUGGESTING AROUND 08Z RETURN OF CEILINGS...SO THERE IS
SOME UNCERTAINTY WITH TIMING HERE. GIVEN WARMING TEMPERATURES
ALOFT...EXPECT THE MARINE LAYER TO REMAIN COMPRESSED ENOUGH TO
KEEP CEILINGS JUST WEST OF ROSEBURG OVERNIGHT. COASTAL CEILINGS
ARE EXPECTED TO CONTINUE INTO SATURDAY AFTERNOON. CEILINGS IN THE
1000 TO 1500 FOOT RANGE ARE EXPECTED TO REMAIN IN ALMOST ALL OF
THE COASTAL WATERS OUT TO 60 NM FOR THE NEXT 24 HOURS. ELSEWHERE...
AREAS WELL INLAND FROM THE COAST SHOULD STAY VFR THROUGH TOMORROW.
SVEN
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS UNTIL 5 AM PDT
EARLY THIS MORNING FOR PZZ376.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 5 AM PDT EARLY THIS
MORNING FOR PZZ376.
$$
AREA FORECAST DISCUSSION
NWS MEDFORD OR
930 PM PDT FRI JUN 14 2013
.UPDATE...
AN UPDATE HAS BEEN MADE TO THE FORECAST FOR SATURDAY AFTERNOON AND
EVENING. MODEL CONSENSUS INDICATES A GOOD CHANCE OF THUNDERSTORMS
OVER THE OREGON CASCADES FROM MT MCLOUGHLIN NORTH AND
NORTHEASTWARD, SO HAVE INCREASED PROBABILITIES THERE. ALSO ADDED
SOME SLIGHT CHANCE MENTION IN NORTHERN CALIFORNIA. BTL
&&
.DISCUSSION...
BENIGN WEATHER THIS EVENING WILL FEATURE A SUBTLE CHANGE THAT
WILL LIKELY RESULT IN SOME RUMBLES OF THUNDER ON SATURDAY
AFTERNOON AND EVENING, PRIMARILY FROM AROUND CRATER LAKE NATIONAL
PARK NORTHEASTWARD. A FRONTAL SYSTEM CURRENTLY CROSSING 130 WEST
LONGITUDE WILL PUSH INTO THE FORECAST AREA TOMORROW AFTERNOON
PROVIDING SOME UPPER LEVEL FORCING FOR THUNDERSTORM ACTIVITY ALONG
AND NEAR THE CASCADES. GFS40, NAM12, AND SREF GUIDANCE ALL
INDICATE MOISTURE TO BE SUFFICIENT FOR ISOLATED THUNDERSTORM
ACTIVITY ALONG WITH SUFFICIENT INSTABILITY IN SOME OF THE
MENTIONED AREA. THE TRINITY ALPS AREA IN NORTHERN CALIFORNIA COULD
GET IN ON THE THUNDER, BUT IT IS LESS LIKELY THERE. THE MAIN AREA
OF CONCERN IS CRATER LAKE NORTHEASTWARD, WHERE ORGANIZED MULTICELL
THUNDERSTORMS COULD RESULT IN SCATTERED LIGHTNING COVERAGE DURING
THE EARLY TO MID EVENING HOURS. BTL
&&
.AVIATION...
BASED ON THE 15/00Z TAF CYCLE.
LATEST HIGH-RESOLUTION RAP MODEL DATA SUGGESTS THE MARINE LAYER AND
LIKELY MVFR CEILINGS WILL AFFECT THE COAST...MOST LIKELY ALONG AND
NORTH OF CAPE BLANCO...BY AROUND 02Z WITH OTHER GUIDANCE SUGGESTING
AROUND 08Z RETURN OF CEILINGS...SO THERE IS SOME UNCERTAINTY WITH
TIMING HERE. GIVEN WARMING TEMPERATURES ALOFT...EXPECT THE MARINE
LAYER TO REMAIN COMPRESSED ENOUGH TO KEEP CEILINGS JUST WEST OF
ROSEBURG OVERNIGHT. COASTAL CEILINGS ARE EXPECTED TO CONTINUE INTO
SATURDAY AFTERNOON. CEILINGS IN THE 1000 TO 1500 FOOT RANGE ARE
EXPECTED TO REMAIN IN ALMOST ALL OF THE COASTAL WATERS OUT TO 60 NM
FOR THE NEXT 24 HOURS. ELSEWHERE...AREAS WELL INLAND FROM THE COAST
SHOULD STAY VFR THROUGH TOMORROW. SVEN
&&
.PREV DISCUSSION... /ISSUED 233 PM PDT FRI JUN 14 2013/
DISCUSSION...THE COMBINATION OF WEAK UPPER RIDGING AND A WEAK LOW
LEVEL THERMAL TROUGH ALONG THE NORTHERN CALIFORNIA COAST IS
LEADING TO A SUNNY AND WARMER DAY TODAY ACROSS THE ENTIRE AREA
TODAY. TEMPERATURES ARE GENERALLY RUNNING 5-10 DEGREES WARMER THAN
YESTERDAY AT THIS TIME. WE MAY SEE SOME AFTERNOON CUMULUS OVER THE
MOUNTAINS AS HEATING CONTINUES TODAY, BUT FORECAST SOUNDINGS SHOW
US REMAINING CAPPED BELOW THE LCL, SO WE SHOULDN`T SEE MUCH IN THE
VALLEYS. WHATEVER CUMULUS DOES DEVELOP WILL DISSIPATE AROUND
SUNSET WITH CLEAR SKIES AGAIN TONIGHT. THE EXCEPTION WILL BE AT
THE COAST WHERE STRATUS WILL LIKELY DEVELOP RIGHT ALONG THE
COASTAL STRIP LATER TONIGHT.
THERE IS A LARGE UPPER TROUGH CENTERED AROUND 50N/140W OVER THE
NORTHEAST PACIFIC THAT IS SLOWLY CHURNING IN OUR DIRECTION. SW
FLOW ALOFT WILL RESULT IN GRADUALLY INCREASING MOISTURE AND
INSTABILITY OVER THE WEEKEND. FORECAST SOUNDINGS SHOW THE CAP
WEAKENING OVER THE VALLEYS BUT NOT QUITE BREAKING, WHEREAS THE
MOUNTAINS WILL BECOME UNCAPPED DURING THE AFTERNOONS. THIS WILL
LEAD TO AFTERNOON AND EVENING CONVECTION OVER THE MOUNTAINS BOTH
SATURDAY AND SUNDAY. EVEN THOUGH THERE IS NO TRIGGER, HEATING
ALONE SHOULD BE SUFFICIENT TO ALLOW SOME THUNDERSTORM DEVELOPMENT
IN THE MOUNTAINS. I DON`T THINK THE VALLEYS WILL GET IN ON THIS
ACTION, SO I HAVE LOWERED POPS IN VALLEY LOCATIONS. THE EXCEPTION
IS NORTHERN KLAMATH COUNTY WHERE SW UPPER FLOW COULD PUSH STORMS
OUT OFF THE MOUNTAINS AT TIMES.
EVEN THOUGH HEIGHTS FALL OVER THE WEEKEND AS THIS SYSTEM NEARS,
TEMPERATURES WILL REMAIN NORMAL TO ABOVE. THERE WILL LIKELY BE A
GREATER MARINE PUSH SATURDAY NIGHT INTO SUNDAY INTO THE UMPQUA AS
THE FLOW BECOMES ONSHORE WITH SUNDAY TEMPERATURES A LITTLE LOWER
THERE.
HAVEN`T MADE ANY SUBSTANTIAL CHANGES TO THE EXTENDED. WE`LL COOL
OFF A BIT MONDAY WITH A GREATER CHANCE OF SHOWERS AND
THUNDERSTORMS AS THE TROUGH EDGES CLOSER TO THE COAST. THE MODELS
ARE FAIRLY CONSISTENT IN BRINGING THE TROUGH ONSHORE TUESDAY,
LINGERING IT OVER THE PACNW WEDNESDAY, AND THEN MOVING IT EAST
THURSDAY. THIS WILL RESULT IN A COOL, SHOWERY PATTERN FROM TUESDAY
THROUGH THURSDAY WITH TEMPERATURES 5-10 DEGREES BELOW NORMAL. WE
WILL BEGIN TO REBOUND FRIDAY AS A RIDGE BUILDS ALONG THE COAST IN
THE WAKE OF THE UPPER LOW. -WRIGHT
AVIATION...VFR CONDITIONS WITH CLEAR SKIES EXIST OVER THE ENTIRE
FORECAST AREA EARLY THIS AFTERNOON. LATEST HIGH-RESOLUTION RAP
MODEL DATA SUGGESTS THE MARINE LAYER AND LIKELY MVFR CEILINGS WILL
AFFECT THE COAST...MOST LIKELY ALONG AND NORTH OF CAPE BLANCO...BY
AROUND 02Z WITH OTHER GUIDANCE SUGGESTING AROUND 08Z RETURN OF
CEILINGS...SO THERE IS SOME UNCERTAINTY WITH TIMING HERE. GIVEN
WARMING TEMPERATURES ALOFT...EXPECT THE MARINE LAYER TO REMAIN
COMPRESSED ENOUGH TO KEEP CEILINGS JUST WEST OF ROSEBURG
OVERNIGHT. COASTAL CEILINGS ARE EXPECTED TO CONTINUE INTO SATURDAY
AFTERNOON. ELSEWHERE...AREAS WELL INLAND FROM THE COAST SHOULD
STAY VFR THROUGH TOMORROW. SK
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
CA...NONE.
PACIFIC COASTAL WATERS...
- SMALL CRAFT ADVISORY FOR WINDS UNTIL 11 PM PDT THIS EVENING FOR
PZZ356.
- SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 PM PDT THIS
EVENING FOR PZZ356.
- SMALL CRAFT ADVISORY FOR WINDS UNTIL 5 AM PDT SATURDAY FOR
PZZ376.
- HAZARDOUS SEAS WARNING UNTIL MIDNIGHT PDT TONIGHT FOR
PZZ376.
$$
BTL/SVEN/WRIGHT
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
921 PM CDT SUN JUN 16 2013
.UPDATE...
RADAR COVERAGE HAS DECREASED MARKEDLY ACROSS NORTHERN AND WESTERN
AREAS OF THE MID STATE. MODELS LEAN TOWARD A DECREASE IN MOISTURE
LEVELS ACROSS NORTHERN AREAS. FURTHERMORE...LATEST MODEL SOLUTIONS
SHOWING NVA TOWARD 12Z ACROSS THE NORTH. BUT...LATEST HRRR SOLUTION
TENDS TO REGENERATE CONVECTION ACROSS CENTRAL AND SOUTHERN AREAS
TOWARD 12Z AS SOME UPPER DIVERGENCE REENTERS THE PICTURE TOWARD
12Z. FOR THE UPDATE...WILL CUT POPS TO 30 PERCENT ACROSS THE
NORTH...BUT WILL KEEP THE 40%-50% FOR MUCH OF THE REMAINDER OF
THE MID STATE. UPDATE OUT SHORTLY.
&&
.PREV DISCUSSION... /ISSUED 721 PM CDT SUN JUN 16 2013/
UPDATE...
00Z TAF DISCUSSION.
AVIATION...
RADAR INDICATES SCATTERED -TSRA CONTINUE OVER SOUTHERN MIDDLE
TENNESSEE WITH A FEW -SHRA OVER NORTHERN AREAS. WILL CONTINUE
MENTION OF VCTS FOR THE EVENING HOURS FOR ALL AIRPORTS...BUT LACK
OF -TSRA OVER NORTHERN ZONES NO LONGER WARRANT TEMPO GROUPS AND MAY
PROMPT REMOVAL OF VCTS FROM TAFS AS WELL. CONVECTION IS EXPECTED
TO DISSIPATE ACROSS MOST OF THE AREA OVERNIGHT. WIDESPREAD CIRRUS
AND MID LEVEL CLOUD COVER WILL LIKELY PREVENT ANY SIGNIFICANT FOG
FORMATION BUT SOME MVFR VIS RESTRICTIONS ARE POSSIBLE AT CKV/CSV
AROUND SUNRISE. SCT CUMULUS TO DEVELOP ONCE AGAIN MONDAY MORNING
WITH CONVECTION REDEVELOPING DURING THE DAY...WITH MORE VCTS BY
AFTERNOON IF NOT SOONER.
SHAMBURGER
PREV DISCUSSION... /ISSUED 630 PM CDT SUN JUN 16 2013/
MESOSCALE UPDATE...
CURRENTLY...SCATTERED CONVECTION SOUTH...MINIMAL ACTIVITY NORTH
BUT BETTER COVERAGE NORTHWARD INTO KY. SEMI ACTIVE PATTERN WITHIN
THE WESTERLIES ALOFT AS MINI DISTURBANCES ARE MOVING EASTWARD
WITHIN THE FLOW. LATEST LAPS DATA SHOWING APPRECIABLE SURFACE BASE
CAPES WITH MAXIMUMS LOCATED ACROSS LEWIS COUNTY...AND ALSO OUR
FAR NW AND THE NORTHERN PLATEAU. THUS...THROUGH THIS EVENING
STRONG STORMS WILL BE AN ONGOING POSSIBILITY. NOT SEEING MUCH
OVERNIGHT DIVERGENCE SO NOT LOOKING FOR WIDESPREAD RAINFALL TO
DEVELOP ALTHOUGH MRH LEVELS DO INCREASE SLIGHTLY THROUGH 12Z
ACROSS OUR SOUTHERN COUNTIES.
PREV DISCUSSION... /ISSUED 317 PM CDT SUN JUN 16 2013/
DISCUSSION...
GENERAL TREND FOR THE WEEK AHEAD WILL FEATURE A BUILDING H5 RIDGE
TO OUR WEST WITH OCCASIONAL WEAK SHORT WAVES IN THE NORTHWEST FLOW
ALOFT. BEST CHANCE OF RAIN WILL BE MONDAY INTO EARLY TUESDAY.
AFTER A WEAK COLD FRONTAL PASSAGE ON TUESDAY...EXPECT MAX TEMPS TO
INCREASE TO 85 TO 90 AREA WIDE MID/LATE WEEK AS UPPER LEVEL RIDGE
EDGES CLOSER TO MIDDLE TN.
THIS AFTERNOON/S TEMPS WERE NEAR SATURDAY/S BUT DEW POINTS WERE UP
5 TO 10 DEGREES DUE TO SOUTH FLOW ACROSS THE REGION BEHIND DEPARTED
SFC HIGH PRESSURE. INSTABILITY IS GREATER TODAY BUT STORMS HAVE
BEEN SLOW TO FIRE PARTLY DUE TO EXTENSIVE MID/HIGH CLOUDS
STREAMING IN FROM THE WEST. STILL THINK SOME STORMS WILL DEVELOP
OVER MIDDLE TN NEXT COUPLE HOURS...AND ADDITIONAL STORMS SHOULD
MOVE IN FROM THE WEST WITH THE APPROACHING WEAK SHORT WAVE.
ABOVE AVERAGE CHANCE OF STORMS MONDAY/TUESDAY AS ANOTHER WEAK
SHORT WAVE MOVES INTO THE REGION. BEST CHANCE SHOULD BE LATE
MONDAY INTO EARLY TUESDAY AS WAVE MOVES ACROSS THE AREA AND A WEAK
COLD FRONT MOVES IN FROM THE NORTH. NOT A STRONG PUSH BEHIND THIS
FRONT BUT EXPECT/HOPE IT TO MOVE JUST SOUTH OF MIDDLE TN TUESDAY
NIGHT.
NOT MUCH PRECIP EXPECTED WED/THURS AS MOISTURE SHOULD DECREASE
BEHIND THE FRONT. HOWEVER...LOW LEVEL MOISTURE WILL INCREASE AGAIN
BY FRIDAY AS SFC HIGH SLIDES TO THE EAST. POTENTIAL FOR STORMS
FRIDAY THROUGH NEXT WEEKEND SHOULD BE LIMITED BY INCREASINGLY
STRONG HIGH PRESSURE ALOFT.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
21
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
910 PM CDT SUN JUN 16 2013
.DISCUSSION...WATER VAPOR SATELLITE/UPPER AIR PROFILERS/WSR-88D
VAD WIND PROFILES INDICATE SEVERAL 500 MB MID LEVEL SHORTWAVES
EMBEDDED WITHIN NEARLY ZONAL FLOW ALOFT ACROSS THE
CENTRAL/SOUTHERN PLAINS AND MIDDLE/LOWER MISSISSIPPI VALLEYS THIS
EVENING. SCATTERED SHOWERS AND THUNDERSTORMS ACROSS THE MID SOUTH
DISSIPATED A FEW HOURS AGO WITH THE MOST OF THE CONVECTIVE ACTIVITY
THIS EVENING OCCURRING ACROSS PORTIONS OF OKLAHOMA...MISSOURI...ARKANSAS...AND
TEXAS. TEMPERATURES AS OF 8 PM CDT RANGE FROM THE LOWER TO MIDDLE
80S WEST OF THE MISSISSIPPI RIVER...AND 70S TO LOWER 80S EAST.
SHOWER AND THUNDERSTORM POTENTIAL FOR THE REMAINDER OF THE NIGHT
REMAINS THE PREDOMINANT FORECAST CHALLENGE.
00Z KLZK UPPER AIR SOUNDING STILL REMAINS QUITE UNSTABLE WITH
SURFACE BASED CAPE VALUES AROUND 3200 J/KG...LI/S AROUND -8...AND
VERY LITTLE CONVECTIVE INHIBITION. INSTABILITY AT KJAN REMAINS
SIMILAR WITH MUCH MORE LOW LEVEL MOISTURE PRESENT THAN LZK.
MEANWHILE...INSTABILITY IS LOWER AT OHX THIS EVENING. 18Z MODELS
AND THE 00Z NAM ARE NOT HANDLING THE CURRENT CONVECTIVE ACTIVITY
PARTICULARLY WELL. THE LATEST RAPID REFRESH /HRRR/ INDICATES THE
BEST POTENTIAL FOR SHOWER/THUNDERSTORM ACTIVITY WILL REMAIN MAINLY
ALONG AND WEST OF THE MISSISSIPPI RIVER OVERNIGHT. AN ISOLATED
STRONG TO PERHAPS SEVERE THUNDERSTORM MAY BE POSSIBLE FOR THE NEXT
FEW HOURS MAINLY WEST OF THE MISSISSIPPI RIVER. OTHERWISE...OVERALL
POTENTIAL REMAINS LOW AT THIS TIME.
BASED ON THE LATEST TRENDS WILL LOWER POPS SLIGHTLY ACROSS
EASTERN SECTIONS OF THE FORECAST AREA AND KEEP ONGOING CHANCE POPS
ALONG AND WEST OF THE MISSISSIPPI RIVER. WILL ALSO ADJUST
TEMPERATURES...CLOUD COVER...AND ALL OTHER ELEMENTS AS NEEDED TO
ACCOUNT FOR SHORT TERM TRENDS. OTHERWISE...FORECAST OVERALL IS IN
GOOD SHAPE.
UPDATED GRIDS WILL BE AVAILABLE SHORTLY.
CJC
&&
.PREV DISCUSSION... /ISSUED 620 PM CDT SUN JUN 16 2013/
UPDATE...AVIATION DISCUSSION.
PREV DISCUSSION... /ISSUED 318 PM CDT SUN JUN 16 2013/
DISCUSSION...
WET PATTERN SETTING OVER THE MIDSOUTH OVER THE NEXT COUPLE OF
DAYS AS A COLD FRONT AND SEVERAL SHORTWAVES MOVE INTO THE REGION.
TONIGHT...VERY LOW CONFIDENCE ON WHAT WILL HAPPEN AS MODELS DID
NOT INITIALIZE VERY WELL. ABUNDANCE OF CLOUD COVER OVER THE REGION
HAS KEPT THE ATMOSPHERE MORE STABLE THAN WHAT THE MODELS WERE
INDICATING. THUS THE NAM AND RAP MODELS SHOWED NUMEROUS SHOWERS
AND THUNDERSTORMS DEVELOPING THIS AFTERNOON INTO THE EVENING HOURS
DUE TO THE COMBINATION OF PEAK HEATING AND THE EXPECTED UNSTABLE
ATMOSPHERE. THIS IS NOT THE CASE AT LEAST SO FAR. HOWEVER...WITHIN
THE LAST 45 MINUTES A THUNDERSTORM HAS DEVELOPED OVER PANOLA
COUNTY. THE NAM AND RAP SHOWED WHATEVER ACTIVITY DEVELOPED DYING
OUT AFTER SUNSET. MEANWHILE...OTHER MODELS LIKE THE HRRR SHOWED
DEVELOPMENT ALONG AND AHEAD OF AN OUTFLOW BOUNDARY WHICH IS DRAPED
ACROSS SOUTHERN MISSOURI. BEGINNING TO SEE DEVELOPMENT OCCUR ALONG
THE BOUNDARY BUT NOTHING AHEAD OF IT YET OTHER THAN A FEW SHOWERS.
THE HRRR BRINGS THE ACTIVITY INTO NORTHERN PORTIONS OF THE
MIDSOUTH THIS EVENING AND THEN DISSIPATES IT BY MIDNIGHT. IN
ADDITION...THE GFS AND ECMWF SHOWED LITTLE ACTIVITY OCCURRING THIS
EVENING. IN FACT...THE ECMWF SHOWED LITTLE ACTIVITY THE ENTIRE
NIGHT. HOWEVER...THE GFS AND THE NAM BOTH SHOW REDEVELOPMENT OF
SHOWERS AFTER MIDNIGHT...POSSIBLY DUE TO A WEAK LOW LEVEL JET.
WITH SUCH A WIDE RANGE OF SCENARIOS...HAVE KEPT 40 POPS ACROSS
FROM THE TENNESSEE/MISSISSIPPI LINE NORTHWARD MAINLY DUE TO THE
CONVECTION YOU SEE BEGINNING TO DEVELOP ALONG THE OLD OUTFLOW
BOUNDARY. THINK THIS CONVECTION WILL PUSH DOWN INTO NORTHEAST
ARKANSAS...THE MISSOURI BOOTHEEL...AND NORTHWEST TENNESSEE. MAY
ALSO SEE A FEW MORE POP UP DIURNAL THUNDERSTORMS ACROSS NORTH MISSISSIPPI. DON/T
KNOW IF ANY STORM WILL BE SEVERE BUT WILL KEEP THE STRONG TO
SEVERE WORDING IN THE HWO FOR NOW. LOWS WILL BE IN THE LOWER TO
MID 70S.
MONDAY...A STRONGER SHORTWAVE WILL MOVE INTO THE REGION AS A COLD
FRONT SLIDES SOUTH INTO THE CWA. THE COMBINATION OF THE TWO SHOULD
PRODUCE NUMEROUS SHOWERS AND THUNDERSTORMS ACROSS THE CWA. CLOUD
COVER MAY AFFECT INSTABILITY LIKE IT DID TODAY BUT CAN/T RULE OUT
A FEW STORMS BECOMING STRONG TO SEVERE. ISOLATED HEAVY RAINFALL
UNDERNEATH SLOW MOVING STORMS MAY BE A BIGGEST ISSUE WITH ANY
THUNDERSTORMS THAT OCCUR TOMORROW. THE ACTIVITY WILL CONTINUE INTO
MONDAY NIGHT AND TUESDAY AS THE COLD FRONT SLIDES SOUTHWARD. HIGHS
ON MONDAY AND TUESDAY WILL BE IN THE 80S DUE TO THE CLOUD COVER
AND AMOUNT OF CONVECTION AROUND.
TUESDAY NIGHT INTO WEDNESDAY....THE GFS SLIDES THE FRONT SOUTH OF THE
CWA WHILE THE ECMWF CONTINUES TO HOLD THE FRONT UP OVER NORTH
MISSISSIPPI. BOTH THE GFS/ECMWF ARE CONSISTENT WITH THEIR
SOLUTIONS AND ITS REALLY ANYBODY/S GUESS WHICH IS CORRECT. FOR NOW
WILL CONTINUE WITH CURRENT FORECAST WHICH LEANS TOWARD THE GFS.
THURSDAY AND FRIDAY...UPPER RIDGE BEGINS TO START MOVING BACK INTO
THE AREA FROM THE WEST. SOME DIURNAL CONVECTION COULD OCCUR ON
THURSDAY. OTHERWISE...WARMER TEMPERATURES WILL RETURN WITH HIGHS
IN THE UPPER 80S TO LOWER 90S.
NEXT WEEKEND...HOT AND DRY CONDITIONS ARE EXPECTED AS THE UPPER
RIDGE WILL BE CENTERED OVER THE MIDSOUTH. HIGHS WILL BE IN THE
LOWER TO MID 90S WITH LOWS IN THE 70S.
KRM
&&
.AVIATION...
00Z TAF CYCLE
VFR CONDITIONS WILL PREVAIL THROUGH THIS TAF PERIOD. RADAR TRENDS
CONTINUE TO INDICATE DIMINISHING THUNDERSTORM COVERAGE AND
WEAKENING STORMS. REMOVES MENTION OF TS AT ALL SITES WITH THE
EXCEPTION OF TUP FOR ANOTHER COUPLE OF HOURS. SEE NO FEATURES THAT
INDICATE ADDITIONAL DEVELOPMENT IS LIKELY OVERNIGHT. WINDS WILL BE
LIGHT AND VARIABLE DUE TO MULTIPLE OUTFLOW BOUNDARIES ACROSS THE
MIDSOUTH...BUT GENERALLY FROM THE SOUTH. TOMORROW...THUNDERSTORM
COVERAGE WILL INCREASE AGAIN BY MIDDAY. INCLUDED VCTS AT ALL
SITES. INDIVIDUAL STORMS WILL REDUCE VIS AND MAY RESULT IN STRONG
GUSTY WINDS...BUT PREVAILING CONDITIONS WILL REMAIN VFR.
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 75 86 71 86 / 40 70 80 40
MKL 71 85 69 85 / 40 70 80 30
JBR 72 85 69 87 / 40 70 40 10
TUP 71 88 72 84 / 30 70 70 60
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
620 PM CDT SUN JUN 16 2013
.UPDATE...AVIATION DISCUSSION.
&&
.PREV DISCUSSION... /ISSUED 318 PM CDT SUN JUN 16 2013/
DISCUSSION...
WET PATTERN SETTING OVER THE MIDSOUTH OVER THE NEXT COUPLE OF
DAYS AS A COLD FRONT AND SEVERAL SHORTWAVES MOVE INTO THE REGION.
TONIGHT...VERY LOW CONFIDENCE ON WHAT WILL HAPPEN AS MODELS DID
NOT INITIALIZE VERY WELL. ABUNDANCE OF CLOUD COVER OVER THE REGION
HAS KEPT THE ATMOSPHERE MORE STABLE THAN WHAT THE MODELS WERE
INDICATING. THUS THE NAM AND RAP MODELS SHOWED NUMEROUS SHOWERS
AND THUNDERSTORMS DEVELOPING THIS AFTERNOON INTO THE EVENING HOURS
DUE TO THE COMBINATION OF PEAK HEATING AND THE EXPECTED UNSTABLE
ATMOSPHERE. THIS IS NOT THE CASE AT LEAST SO FAR. HOWEVER...WITHIN
THE LAST 45 MINUTES A THUNDERSTORM HAS DEVELOPED OVER PANOLA
COUNTY. THE NAM AND RAP SHOWED WHATEVER ACTIVITY DEVELOPED DYING
OUT AFTER SUNSET. MEANWHILE...OTHER MODELS LIKE THE HRRR SHOWED
DEVELOPMENT ALONG AND AHEAD OF AN OUTFLOW BOUNDARY WHICH IS DRAPED
ACROSS SOUTHERN MISSOURI. BEGINNING TO SEE DEVELOPMENT OCCUR ALONG
THE BOUNDARY BUT NOTHING AHEAD OF IT YET OTHER THAN A FEW SHOWERS.
THE HRRR BRINGS THE ACTIVITY INTO NORTHERN PORTIONS OF THE
MIDSOUTH THIS EVENING AND THEN DISSIPATES IT BY MIDNIGHT. IN
ADDITION...THE GFS AND ECMWF SHOWED LITTLE ACTIVITY OCCURRING THIS
EVENING. IN FACT...THE ECMWF SHOWED LITTLE ACTIVITY THE ENTIRE
NIGHT. HOWEVER...THE GFS AND THE NAM BOTH SHOW REDEVELOPMENT OF
SHOWERS AFTER MIDNIGHT...POSSIBLY DUE TO A WEAK LOW LEVEL JET.
WITH SUCH A WIDE RANGE OF SCENARIOS...HAVE KEPT 40 POPS ACROSS
FROM THE TENNESSEE/MISSISSIPPI LINE NORTHWARD MAINLY DUE TO THE
CONVECTION YOU SEE BEGINNING TO DEVELOP ALONG THE OLD OUTFLOW
BOUNDARY. THINK THIS CONVECTION WILL PUSH DOWN INTO NORTHEAST
ARKANSAS...THE MISSOURI BOOTHEEL...AND NORTHWEST TENNESSEE. MAY
ALSO SEE A FEW MORE POP UP DIURNAL THUNDERSTORMS ACROSS NORTH MISSISSIPPI. DON/T
KNOW IF ANY STORM WILL BE SEVERE BUT WILL KEEP THE STRONG TO
SEVERE WORDING IN THE HWO FOR NOW. LOWS WILL BE IN THE LOWER TO
MID 70S.
MONDAY...A STRONGER SHORTWAVE WILL MOVE INTO THE REGION AS A COLD
FRONT SLIDES SOUTH INTO THE CWA. THE COMBINATION OF THE TWO SHOULD
PRODUCE NUMEROUS SHOWERS AND THUNDERSTORMS ACROSS THE CWA. CLOUD
COVER MAY AFFECT INSTABILITY LIKE IT DID TODAY BUT CAN/T RULE OUT
A FEW STORMS BECOMING STRONG TO SEVERE. ISOLATED HEAVY RAINFALL
UNDERNEATH SLOW MOVING STORMS MAY BE A BIGGEST ISSUE WITH ANY
THUNDERSTORMS THAT OCCUR TOMORROW. THE ACTIVITY WILL CONTINUE INTO
MONDAY NIGHT AND TUESDAY AS THE COLD FRONT SLIDES SOUTHWARD. HIGHS
ON MONDAY AND TUESDAY WILL BE IN THE 80S DUE TO THE CLOUD COVER
AND AMOUNT OF CONVECTION AROUND.
TUESDAY NIGHT INTO WEDNESDAY....THE GFS SLIDES THE FRONT SOUTH OF THE
CWA WHILE THE ECMWF CONTINUES TO HOLD THE FRONT UP OVER NORTH
MISSISSIPPI. BOTH THE GFS/ECMWF ARE CONSISTENT WITH THEIR
SOLUTIONS AND ITS REALLY ANYBODY/S GUESS WHICH IS CORRECT. FOR NOW
WILL CONTINUE WITH CURRENT FORECAST WHICH LEANS TOWARD THE GFS.
THURSDAY AND FRIDAY...UPPER RIDGE BEGINS TO START MOVING BACK INTO
THE AREA FROM THE WEST. SOME DIURNAL CONVECTION COULD OCCUR ON
THURSDAY. OTHERWISE...WARMER TEMPERATURES WILL RETURN WITH HIGHS
IN THE UPPER 80S TO LOWER 90S.
NEXT WEEKEND...HOT AND DRY CONDITIONS ARE EXPECTED AS THE UPPER
RIDGE WILL BE CENTERED OVER THE MIDSOUTH. HIGHS WILL BE IN THE
LOWER TO MID 90S WITH LOWS IN THE 70S.
KRM
.AVIATION...
00Z TAF CYCLE
VFR CONDITIONS WILL PREVAIL THROUGH THIS TAF PERIOD. RADAR TRENDS
CONTINUE TO INDICATE DIMINISHING THUNDERSTORM COVERAGE AND
WEAKENING STORMS. REMOVES MENTION OF TS AT ALL SITES WITH THE
EXCEPTION OF TUP FOR ANOTHER COUPLE OF HOURS. SEE NO FEATURES THAT
INDICATE ADDITIONAL DEVELOPMENT IS LIKELY OVERNIGHT. WINDS WILL BE
LIGHT AND VARIABLE DUE TO MULTIPLE OUTFLOW BOUNDARIES ACROSS THE
MIDSOUTH...BUT GENERALLY FROM THE SOUTH. TOMORROW...THUNDERSTORM
COVERAGE WILL INCREASE AGAIN BY MIDDAY. INCLUDED VCTS AT ALL
SITES. INDIVIDUAL STORMS WILL REDUCE VIS AND MAY RESULT IN STRONG
GUSTY WINDS...BUT PREVAILING CONDITIONS WILL REMAIN VFR.
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 75 86 71 86 / 40 70 80 40
MKL 71 85 69 85 / 40 70 80 30
JBR 72 85 69 87 / 40 70 40 10
TUP 71 88 72 84 / 30 70 70 60
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
528 AM CDT SAT JUN 15 2013
.UPDATE...ADDED AVIATION SECTION FOR 12Z TAF`S.
&&
.AVIATION...BNA/CKV/CSV...HIGH PRESSURE WILL SHIFT FAR ENOUGH EAST
THIS MORNING TO INTRODUCE WEAK RETURN FLOW TO MIDDLE TENNESSEE.
LOOK FOR CIRRUS CLOUDS TO STREAM IN FROM AN MCS OVER THE MIDWEST,
BUT ANY CIGS WILL LIKELY BE HIGH CIGS. WARMER, WETTER AIR WILL
GRADUALLY FILTER IN TODAY, BUT THE MID STATE WILL REMAIN DRY WITH
VFR WX FOR AT LEAST THE NEXT 24 HRS.
&&
.PREV DISCUSSION... /ISSUED 410 AM CDT SAT JUN 15 2013/
DISCUSSION...
CURRENT RUC ANALYSIS SHOWS A SURFACE RIDGE AXIS FIRMLY ENSCONCED
OVER THE OHIO AND TENNESSEE VALLEYS THIS MORNING...AND A DECENTLY
AMPLIFIED RIDGE JUST TO OUR WEST. THE POSITION OF THIS UPPER RIDGE
HAS MIDDLE TENNESSEE IN A NORTHWESTERLY FLOW ALOFT...AND AS THOSE
OF YOU WHO FOLLOW THESE WRITINGS KNOW ALL TOO WELL...NW FLOW ALOFT
CAN BE VERY TRICKY. THIS MORNING IS NO DIFFERENT. AN MCS OVER NE
MISSOURI AND WEST CENTRAL ILLINOIS IS ON A TRAJECTORY TOWARDS
TENNESSEE. LATEST SHORT TERM GUIDANCE SHOWS THIS SYSTEM DYING AS
IT MOVES SOUTHEASTWARD ALONG THE MISSISSIPPI RIVER...AND DUE TO
THE SUBSIDENCE IN PLACE I WOULD HAVE TO AGREE WITH THOSE
SOLUTIONS...BUT IT WILL HAVE TO BE MONITORED THROUGH THE MORNING
HOURS. IN THE LEAST...BLOW OFF FROM THIS MCS WILL LIKELY USHER IN
HIGH CLOUDS OVER THE STATE...WHICH COULD HAMPER OUR ABILITY TO
REACH THE MIDDLE TO UPPER 80S TODAY. WILL HOLD FIRM THOUGH AS WE
SHOULD HAVE ENOUGH SUBSIDENCE TO GET US CLOSE TO THOSE NUMBERS.
AS WE MOVE INTO TONIGHT AND TOMORROW...THE SURFACE RIDGE WILL MOVE
EASTWARD AND PUT MIDDLE TENNESSEE INTO SOUTHERLY SURFACE FLOW. THIS
WILL INCREASE MOISTURE ACROSS THE STATE DRAMATICALLY BY SUNDAY
AFTERNOON. DEW POINTS WILL CREEP TOWARDS THE 70 DEGREE MARK MUCH
LIKE THE EARLY PART OF LAST WEEK. THIS INCREASE IN BOUNDARY LAYER
MOISTURE...COUPLED WITH THE DEGRADATION OF THE UPPER RIDGE WILL OPEN
US UP TO THE POTENTIAL FOR THUNDERSTORM DEVELOPMENT STARTING SUNDAY
AFTERNOON. WHILE COVERAGE OF ANY CONVECTION SHOULD BE SCATTERED AT
BEST...MID-LEVEL LAPSE RATES SUNDAY AFTERNOON ON THE ORDER OF 6.5 TO
7 DEGREES CELSIUS WILL CREATE A VERY UNSTABLE ENVIRONMENT AND ANY
SHORTWAVE THAT MOVES THROUGH THE TENNESSEE VALLEY WILL LIKELY SPARK
AT LEAST A FEW THUNDERSTORMS...SOME OF WHICH COULD BE STRONG TO
SEVERE. IF THERE IS ANY GOOD NEWS IN THIS...A LACK OF DEEP LAYER
SHEAR SHOULD PREVENT ANY REAL ORGANIZATION SUNDAY. BECAUSE OF THIS
I WILL GO AHEAD AND HIGHLIGHT THIS ISOLATED THREAT OF SEVERE IN THE
HAZARDOUS WEATHER OUTLOOK FOR DAMAGING STRAIGHT LINE WINDS...LARGE
HAIL...AND HEAVY DOWNPOURS WHICH COULD LEAD TO SOME LOCALIZED
FLOODING...BUT THE THREAT SHOULD END AS THE SUN GOES DOWN SUNDAY
EVENING.
BY SUNDAY NIGHT WE SHOULD BEGIN TO SEE A WEAK AND DIFFUSE FRONTAL
SYSTEM DROPPING INTO THE REGION FROM THE NORTH. THIS FRONT WILL
LIKELY SPELL A WET BEGINNING TO THE WORKWEEK AS IT MOVES INTO THE
TENNESSEE VALLEY. WITHOUT ANY KICKER EXPECTED TO PUSH IT THROUGH
THE STATE...THE FRONT COULD BECOME QUASI-STATIONARY AND OPEN US UP
TO A GOOD AMOUNT OF RAINFALL THROUGH TUESDAY AFTERNOON AS MULTIPLE
SHORTWAVES TRAVERSE THIS FRONT. IT IS YET TO BE DETERMINED HOW
PROGRESSIVE THIS FRONT WILL BE. THE LATEST EURO GUIDANCE WANTS TO
HANG THE FRONT UP OVER SOUTHERN PORTIONS OF TENNESSEE/NORTHERN
PORTIONS OF ALABAMA...AND THE GFS IS MUCH MORE PROGRESSIVE...PUSHING
THE FRONT COMPLETELY OUT OF THE STATE EARLY TUESDAY. WITH THE
NUMBER OF DIVERSE SOLUTIONS OF THE GFS ENSEMBLE AND THE PROPENSITY
OF THE GFS TO BE TOO PROGRESSIVE...I WILL GO WITH THE SLOWER EURO
SOLUTION AND KEEP POPS IN THROUGH TUESDAY NIGHT. AS FAR AS THE
INTENSITY OF THUNDERSTORMS GOES MONDAY AND TUESDAY...WILL REFRAIN
FROM ADDING ANY SEVERE WORDING FOR THESE PERIODS...BUT IT MAY BECOME
NECESSARY IN FUTURE FORECASTS PACKAGES.
BY WEDNESDAY OR WEDNESDAY NIGHT MIDDLE TENNESSEE SHOULD BEGIN TO DRY
OUT...BUT TEMPERATURES WILL NOT GET MUCH OF A CHANCE TO SUBSIDE. WE
MAY SEE AFTERNOON TEMPS BACK TOWARDS NORMAL TUESDAY AND WEDNESDAY...
BUT DEW POINTS WILL REMAIN ELEVATED AND WITH RIDGING EXPECTED TO
BUILD BACK INTO THE SOUTH...TEMPERATURES SHOULD WARM BACK ABOVE
NORMAL BY THE END OF THE WEEK AND INTO NEXT WEEKEND.
27/UNGER
AVIATION...06Z TAF DISCUSSION.
VFR. IR SATELLITE IMAGERY CONTINUES TO SHOWS SOME CIRRUS
SPREADING ACROSS THE MID STATE FROM THE NORTHWEST...AND SCT-BKN
CIRRUS WILL REMAIN THROUGHOUT THE TAF PERIOD. DRY LOW LEVELS
SHOULD LIMIT FOG FORMATION OVERNIGHT BUT CANNOT RULE OUT BRIEF
MVFR VIS AT CKV/CSV IN THE 10-12Z TIMEFRAME. LIGHT TO CALM WINDS
OVERNIGHT WILL BECOME SOUTH TO SOUTHWEST 5-10 KTS SATURDAY
MORNING.
SHAMBURGER
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
ROSE
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
410 AM CDT SAT JUN 15 2013
.DISCUSSION...
CURRENT RUC ANALYSIS SHOWS A SURFACE RIDGE AXIS FIRMLY ENSCONCED
OVER THE OHIO AND TENNESSEE VALLEYS THIS MORNING...AND A DECENTLY
AMPLIFIED RIDGE JUST TO OUR WEST. THE POSITION OF THIS UPPER RIDGE
HAS MIDDLE TENNESSEE IN A NORTHWESTERLY FLOW ALOFT...AND AS THOSE
OF YOU WHO FOLLOW THESE WRITINGS KNOW ALL TOO WELL...NW FLOW ALOFT
CAN BE VERY TRICKY. THIS MORNING IS NO DIFFERENT. AN MCS OVER NE
MISSOURI AND WEST CENTRAL ILLINOIS IS ON A TRAJECTORY TOWARDS
TENNESSEE. LATEST SHORT TERM GUIDANCE SHOWS THIS SYSTEM DYING AS
IT MOVES SOUTHEASTWARD ALONG THE MISSISSIPPI RIVER...AND DUE TO
THE SUBSIDENCE IN PLACE I WOULD HAVE TO AGREE WITH THOSE
SOLUTIONS...BUT IT WILL HAVE TO BE MONITORED THROUGH THE MORNING
HOURS. IN THE LEAST...BLOW OFF FROM THIS MCS WILL LIKELY USHER IN
HIGH CLOUDS OVER THE STATE...WHICH COULD HAMPER OUR ABILITY TO
REACH THE MIDDLE TO UPPER 80S TODAY. WILL HOLD FIRM THOUGH AS WE
SHOULD HAVE ENOUGH SUBSIDENCE TO GET US CLOSE TO THOSE NUMBERS.
AS WE MOVE INTO TONIGHT AND TOMORROW...THE SURFACE RIDGE WILL MOVE
EASTWARD AND PUT MIDDLE TENNESSEE INTO SOUTHERLY SURFACE FLOW. THIS
WILL INCREASE MOISTURE ACROSS THE STATE DRAMATICALLY BY SUNDAY
AFTERNOON. DEW POINTS WILL CREEP TOWARDS THE 70 DEGREE MARK MUCH
LIKE THE EARLY PART OF LAST WEEK. THIS INCREASE IN BOUNDARY LAYER
MOISTURE...COUPLED WITH THE DEGRADATION OF THE UPPER RIDGE WILL OPEN
US UP TO THE POTENTIAL FOR THUNDERSTORM DEVELOPMENT STARTING SUNDAY
AFTERNOON. WHILE COVERAGE OF ANY CONVECTION SHOULD BE SCATTERED AT
BEST...MID-LEVEL LAPSE RATES SUNDAY AFTERNOON ON THE ORDER OF 6.5 TO
7 DEGREES CELSIUS WILL CREATE A VERY UNSTABLE ENVIRONMENT AND ANY
SHORTWAVE THAT MOVES THROUGH THE TENNESSEE VALLEY WILL LIKELY SPARK
AT LEAST A FEW THUNDERSTORMS...SOME OF WHICH COULD BE STRONG TO
SEVERE. IF THERE IS ANY GOOD NEWS IN THIS...A LACK OF DEEP LAYER
SHEAR SHOULD PREVENT ANY REAL ORGANIZATION SUNDAY. BECAUSE OF THIS
I WILL GO AHEAD AND HIGHLIGHT THIS ISOLATED THREAT OF SEVERE IN THE
HAZARDOUS WEATHER OUTLOOK FOR DAMAGING STRAIGHT LINE WINDS...LARGE
HAIL...AND HEAVY DOWNPOURS WHICH COULD LEAD TO SOME LOCALIZED
FLOODING...BUT THE THREAT SHOULD END AS THE SUN GOES DOWN SUNDAY
EVENING.
BY SUNDAY NIGHT WE SHOULD BEGIN TO SEE A WEAK AND DIFFUSE FRONTAL
SYSTEM DROPPING INTO THE REGION FROM THE NORTH. THIS FRONT WILL
LIKELY SPELL A WET BEGINNING TO THE WORKWEEK AS IT MOVES INTO THE
TENNESSEE VALLEY. WITHOUT ANY KICKER EXPECTED TO PUSH IT THROUGH
THE STATE...THE FRONT COULD BECOME QUASI-STATIONARY AND OPEN US UP
TO A GOOD AMOUNT OF RAINFALL THROUGH TUESDAY AFTERNOON AS MULTIPLE
SHORTWAVES TRAVERSE THIS FRONT. IT IS YET TO BE DETERMINED HOW
PROGRESSIVE THIS FRONT WILL BE. THE LATEST EURO GUIDANCE WANTS TO
HANG THE FRONT UP OVER SOUTHERN PORTIONS OF TENNESSEE/NORTHERN
PORTIONS OF ALABAMA...AND THE GFS IS MUCH MORE PROGRESSIVE...PUSHING
THE FRONT COMPLETELY OUT OF THE STATE EARLY TUESDAY. WITH THE
NUMBER OF DIVERSE SOLUTIONS OF THE GFS ENSEMBLE AND THE PROPENSITY
OF THE GFS TO BE TOO PROGRESSIVE...I WILL GO WITH THE SLOWER EURO
SOLUTION AND KEEP POPS IN THROUGH TUESDAY NIGHT. AS FAR AS THE
INTENSITY OF THUNDERSTORMS GOES MONDAY AND TUESDAY...WILL REFRAIN
FROM ADDING ANY SEVERE WORDING FOR THESE PERIODS...BUT IT MAY BECOME
NECESSARY IN FUTURE FORECASTS PACKAGES.
BY WEDNESDAY OR WEDNESDAY NIGHT MIDDLE TENNESSEE SHOULD BEGIN TO DRY
OUT...BUT TEMPERATURES WILL NOT GET MUCH OF A CHANCE TO SUBSIDE. WE
MAY SEE AFTERNOON TEMPS BACK TOWARDS NORMAL TUESDAY AND WEDNESDAY...
BUT DEW POINTS WILL REMAIN ELEVATED AND WITH RIDGING EXPECTED TO
BUILD BACK INTO THE SOUTH...TEMPERATURES SHOULD WARM BACK ABOVE
NORMAL BY THE END OF THE WEEK AND INTO NEXT WEEKEND.
27/UNGER
&&
.AVIATION...06Z TAF DISCUSSION.
VFR. IR SATELLITE IMAGERY CONTINUES TO SHOWS SOME CIRRUS
SPREADING ACROSS THE MID STATE FROM THE NORTHWEST...AND SCT-BKN
CIRRUS WILL REMAIN THROUGHOUT THE TAF PERIOD. DRY LOW LEVELS
SHOULD LIMIT FOG FORMATION OVERNIGHT BUT CANNOT RULE OUT BRIEF
MVFR VIS AT CKV/CSV IN THE 10-12Z TIMEFRAME. LIGHT TO CALM WINDS
OVERNIGHT WILL BECOME SOUTH TO SOUTHWEST 5-10 KTS SATURDAY
MORNING.
SHAMBURGER
&&
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 89 67 91 69 / 0 05 30 40
CLARKSVILLE 89 65 91 68 / 0 05 30 30
CROSSVILLE 84 63 84 66 / 0 05 30 40
COLUMBIA 90 67 91 70 / 0 05 30 30
LAWRENCEBURG 90 66 91 69 / 0 05 30 30
WAVERLY 89 65 91 69 / 0 05 30 30
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
27
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1012 PM CDT SUN JUN 16 2013
.UPDATE...
SOME CONVECTION MAY SNEAK ACROSS THE RED RIVER LATE THIS
EVENING...BUT THE BETTER CHANCES WILL BE LATE TONIGHT INTO MONDAY
MORNING. THE MCS THAT HAS RAPIDLY DEVELOPED IN SOUTHWESTERN KANSAS
MAY REACH THE RED RIVER VALLEY BEFORE DAYBREAK. THE MAIN SHORTWAVE
WILL TRACK THROUGH OKLAHOMA...AND A NEGLIGIBLE LLJ WILL LIMIT ITS
MOTION/EXPANSION SOUTH OF THE RED RIVER. LOW CONFIDENCE IN THE
ACTIVITY REACHING THE I-20 CORRIDOR...BUT WILL MAINTAIN LOW POPS
ALONG AND NORTH OF I-20 BOTH BEFORE AND AFTER DAYBREAK...WITH THE
BEST CHANCES HUGGING OKLAHOMA.
25
&&
.AVIATION...
UPDATE...MCS HAS DEVELOPED IN KS. HAVE INCLUDED VCTS IN METROPLEX
TAFS FROM 11-14Z...AS THERE IS A CHANCE WEAKENING MCS MAKES IT
INTO THE REGION AT THAT TIME.
&&
.../PREVIOUS AVIATION DISCUSSION/...
DIFFICULT CONVECTIVE FORECAST DURING THE NEXT 12 HOURS DUE TO
DIFFERING MODEL OUTPUT AND CONVECTION LARGELY DRIVEN BY MESOSCALE
PROCESSES. CONVECTION WILL BE MOVING TOWARD THE REGION IN NW FLOW
ALOFT...BUT WHETHER THERE IS THE SUPPORT FOR IT TO HOLD TOGETHER
LONG ENOUGH TO IMPACT THE TAF SITES IS A BIT MORE IN QUESTION.
AIRMASS OVER THE REGION IS NOT ESPECIALLY FAVORABLE
THERMODYNAMICALLY...NOR ARE THE LOW LEVEL WIND FIELDS VERY
IMPRESSIVE FOR A GOOD MCS PROPAGATION EVENT. NONETHELESS MODELS
ARE SHOWING TWO WINDOWS OF POSSIBLE CONVECTIVE ACTIVITY IN NORTH
TEXAS.
THE FIRST ONE WOULD BE LATE EVENING FROM 4Z-8Z AS ADVERTISED BY
THE RUC/4KMWRF/NAM AND PREVIOUS RUNS OF THE HRRR...WHICH TAKE
CURRENT CONVECTION IN OKLAHOMA AND GROW IT UPSCALE DURING THE
NEXT 2 HOURS AND PUSH IT INTO THE METROPLEX BEFORE MIDNIGHT LOCAL.
CURRENT RADAR TRENDS TO OUR NORTH DO NOT SEEM TO SUPPORT THIS IDEA
WITH CONVECTION REMAINING A BIT TOO ISOLATED FOR GOOD COLD POOL
DEVELOPMENT. THESE MODELS CAN HAVE ISSUES WITH OVER-ESTIMATING THE
INFLUENCE OF OUTFLOWS ENHANCING CONVECTION AND ITS PROPAGATION.
WILL NOT MENTION VCTS FOR THIS THREAT WINDOW BUT WILL CONTINUE TO
MONITOR TRENDS DURING THE NEXT COUPLE OF HOURS AND JUMP ON IT IF
ACTIVITY CAN INCREASE IN COVERAGE BETWEEN OKC-FDR.
THE SECOND WINDOW OF CONVECTIVE OPPORTUNITY WILL BE FROM 10Z TO
14Z FROM CONVECTION NOW FORMING IN COLORADO. THIS HAS A BETTER
SHOT TO MAKE IT INTO THE AREA...AS IT WILL BE SUPPORTED BY LIFT
FROM A SHORTWAVE TROUGH. THE LATEST RUN OF THE HRRR AND A HI-RES
WRF ARE HITTING ON THIS POTENTIAL WITH A DECAYING MCS ARRIVING
NEAR OR JUST BEFORE SUNRISE. AM ALMOST READY TO INCLUDE VCTS IN
TAFS FROM 10Z-13Z...BUT WILL WAIT TO SEE HOW CONVECTION EVOLVES IN
THE HIGH PLAINS AND WHETHER THE FIRST POSSIBLE ROUND OF CONVECTION
NOW OVER OKLAHOMA DOES IN FACT STEAL THE SHOW.
SO IN SUMMARY NO CHANGES WITH THE 00Z TAF ISSUANCE JUST YET...BUT
AMENDMENTS FOR A WINDOW OF VCTS LOOK LIKELY IN THE NEXT 2-3
HOURS.
TR.92
&&
.PREV DISCUSSION... /ISSUED 251 PM CDT SUN JUN 16 2013/
A LESS ACTIVE AFTERNOON TODAY VERSUS THIS TIME YESTERDAY WITH THE
OLD UPPER TROUGH NOW LONG GONE AND AN UPPER RIDGE THAT HAS EXPANDED
WESTWARD ACROSS SOUTH/CENTRAL TX. THOUGH A ROGUE ISOLATED STRONG
STORM IS POSSIBLE NORTH OF I-20 THIS AFTERNOON...BETTER CHANCES
WILL LIKELY COME LATER TONIGHT. A SHORTWAVE OVER THE OK/TX
PANHANDLES WILL MOVE ESE TOWARD THE RED RIVER VALLEY AFTER MIDNIGHT.
A FEW STORMS WERE ALREADY POPPING ACROSS CENTRAL AND NORTHERN OK.
HIGH RESOLUTION HRRR/ARW-EAST/TEXAS TECH WRF MODELS ALL SHOW
CURRENT ISOLATED STORMS OVER NW OK INCREASING IN COVERAGE IN A
WEST-EAST LINE THIS EVENING...THEN DIVING SOUTHEAST TOWARD THE RED
RIVER LATE TONIGHT. TIMING THE LINEAR MCS TONIGHT IS SOMEWHAT
PROBLEMATIC HOWEVER AS THE HRRR IS MUCH FASTER THAN THE OTHER TWO
MODELS IN BRINGING ACTIVITY INTO THE RED RIVER VALLEY. CONSIDERING
WHERE THIS ACTIVITY IS FORMING AT THE MOMENT...WILL GO WITH THE
SLOWER TIMING MOSTLY BETWEEN MIDNIGHT AND SUNRISE MONDAY MORNING.
POPS WILL VARY FROM 50 PERCENT ACROSS THE IMMEDIATE RED RIVER AREA
TO AROUND 20 PERCENT ACROSS THE I-20 CORRIDOR. THE LINEAR MCS
SHOULD WEAKEN WITH THE VEERING/WEAKENING OF A 30-35KT NOCTURNAL
LLJ NEAR SUNRISE MONDAY MORNING.
THE FORECAST FOR LATER MONDAY AND THROUGH EARLY WEDNESDAY BECOMES A
BIT MORE DIFFICULT DUE TO THE UPPER RIDGE ANCHORED OVER SOUTH AND
CENTRAL TX AND WHERE ANY OUTFLOW BOUNDARIES SET UP ACROSS THE
NORTH. HAVE LINGERED BEST CHANCES AFTER SUNRISE MONDAY ACROSS THE
NORTHEAST COUNTIES WITH THE WEAKENING COMPLEX AND A SHORTWAVE
PASSING SOUTHEAST OVER ARKANSAS. LOW CHANCES LOOK PRUDENT FOR THE
AFTERNOON HOURS NEAR ANY OUTFLOWS ACROSS THE NORTHERN HALF OF THE
CWA. BY MONDAY NIGHT...ANOTHER SHORTWAVE DISTURBANCE MOVES EAST
FROM WEST TX AND WILL CARRY HIGHER CHANCES ACROSS THE WESTERN
COUNTIES BY MONDAY EVENING. THIS SYSTEM SHOULD WEAKEN AS IT HITS
THE RIDGE OVERNIGHT AND INTO TUESDAY MORNING. ON MORE SHORTWAVE
WILL TRANSITION SOUTHEAST OVER THE TOP OF THE UPPER RIDGE AND
TOWARD OUR OLD OUTFLOW BOUNDARY OVER THE NORTHERN COUNTIES WITH
ISOLATED TO SCATTERED STORMS FOR THE PM HOURS ONCE AGAIN. FEEL THE
UPPER RIDGE WILL KEEP AREAS FROM WACO AND ATHENS SOUTHWARD MAINLY
CAPPED AND DRY...THOUGH A ROGUE SHOWER CANNOT BE COMPLETELY RULED
OUT OVER OUR CENTRAL TX COUNTIES.
THE UPPER RIDGE EXPANDS NORTHWARD OVER NORTH TEXAS WEDNESDAY AS AN
UPPER LOW AND ASSOCIATED LONGWAVE TROUGH DEEPEN ACROSS THE WESTERN
U.S. HAVE LINGERED LOW RAIN CHANCES ACROSS THE FAR NORTHEAST CWA
WHERE SOME WEAKNESS ALOFT WILL REMAIN...BUT CONFIDENCE WILL BE
WANING BY THEN ON RAIN CHANCES. SUBSIDENCE AND DRY/HOT WEATHER
TAKE HOLD THE LATTER HALF OF THE WEEK INTO NEXT WEEKEND WITH RAIN
CHANCES NEAR ZERO. HIGHS WILL RISE INTO THE UPPER 90S AND 100 BY
FRIDAY AND SATURDAY...ESPECIALLY ACROSS THE WESTERN COUNTIES BY
NEXT WEEKEND.
05/
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 77 93 75 89 75 / 20 20 30 30 20
WACO, TX 75 95 75 92 75 / 5 0 20 10 10
PARIS, TX 74 90 72 87 71 / 50 50 20 40 40
DENTON, TX 76 91 73 88 73 / 30 30 30 40 30
MCKINNEY, TX 75 92 72 88 72 / 30 30 20 40 30
DALLAS, TX 77 94 75 89 76 / 20 20 20 30 20
TERRELL, TX 75 93 74 89 73 / 20 20 20 30 20
CORSICANA, TX 75 95 74 91 74 / 5 5 20 10 10
TEMPLE, TX 75 96 73 93 73 / 5 0 10 10 10
MINERAL WELLS, TX 75 93 73 89 71 / 30 20 40 30 20
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
92/25
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
937 PM CDT SUN JUN 16 2013
.AVIATION...
UPDATE...MCS HAS DEVELOPED IN KS. HAVE INCLUDED VCTS IN METROPLEX
TAFS FROM 11-14Z...AS THERE IS A CHANCE WEAKENING MCS MAKES IT
INTO THE REGION AT THAT TIME.
.../PREVIOUS AVIATION DISCUSSION/...
DIFFICULT CONVECTIVE FORECAST DURING THE NEXT 12 HOURS DUE TO
DIFFERING MODEL OUTPUT AND CONVECTION LARGELY DRIVEN BY MESOSCALE
PROCESSES. CONVECTION WILL BE MOVING TOWARD THE REGION IN NW FLOW
ALOFT...BUT WHETHER THERE IS THE SUPPORT FOR IT TO HOLD TOGETHER
LONG ENOUGH TO IMPACT THE TAF SITES IS A BIT MORE IN QUESTION.
AIRMASS OVER THE REGION IS NOT ESPECIALLY FAVORABLE
THERMODYNAMICALLY...NOR ARE THE LOW LEVEL WIND FIELDS VERY
IMPRESSIVE FOR A GOOD MCS PROPAGATION EVENT. NONETHELESS MODELS
ARE SHOWING TWO WINDOWS OF POSSIBLE CONVECTIVE ACTIVITY IN NORTH
TEXAS.
THE FIRST ONE WOULD BE LATE EVENING FROM 4Z-8Z AS ADVERTISED BY
THE RUC/4KMWRF/NAM AND PREVIOUS RUNS OF THE HRRR...WHICH TAKE
CURRENT CONVECTION IN OKLAHOMA AND GROW IT UPSCALE DURING THE
NEXT 2 HOURS AND PUSH IT INTO THE METROPLEX BEFORE MIDNIGHT LOCAL.
CURRENT RADAR TRENDS TO OUR NORTH DO NOT SEEM TO SUPPORT THIS IDEA
WITH CONVECTION REMAINING A BIT TOO ISOLATED FOR GOOD COLD POOL
DEVELOPMENT. THESE MODELS CAN HAVE ISSUES WITH OVER-ESTIMATING THE
INFLUENCE OF OUTFLOWS ENHANCING CONVECTION AND ITS PROPAGATION.
WILL NOT MENTION VCTS FOR THIS THREAT WINDOW BUT WILL CONTINUE TO
MONITOR TRENDS DURING THE NEXT COUPLE OF HOURS AND JUMP ON IT IF
ACTIVITY CAN INCREASE IN COVERAGE BETWEEN OKC-FDR.
THE SECOND WINDOW OF CONVECTIVE OPPORTUNITY WILL BE FROM 10Z TO
14Z FROM CONVECTION NOW FORMING IN COLORADO. THIS HAS A BETTER
SHOT TO MAKE IT INTO THE AREA...AS IT WILL BE SUPPORTED BY LIFT
FROM A SHORTWAVE TROUGH. THE LATEST RUN OF THE HRRR AND A HI-RES
WRF ARE HITTING ON THIS POTENTIAL WITH A DECAYING MCS ARRIVING
NEAR OR JUST BEFORE SUNRISE. AM ALMOST READY TO INCLUDE VCTS IN
TAFS FROM 10Z-13Z...BUT WILL WAIT TO SEE HOW CONVECTION EVOLVES IN
THE HIGH PLAINS AND WHETHER THE FIRST POSSIBLE ROUND OF CONVECTION
NOW OVER OKLAHOMA DOES IN FACT STEAL THE SHOW.
SO IN SUMMARY NO CHANGES WITH THE 00Z TAF ISSUANCE JUST YET...BUT
AMENDMENTS FOR A WINDOW OF VCTS LOOK LIKELY IN THE NEXT 2-3
HOURS.
TR.92
&&
.PREV DISCUSSION... /ISSUED 251 PM CDT SUN JUN 16 2013/
A LESS ACTIVE AFTERNOON TODAY VERSUS THIS TIME YESTERDAY WITH THE
OLD UPPER TROUGH NOW LONG GONE AND AN UPPER RIDGE THAT HAS EXPANDED
WESTWARD ACROSS SOUTH/CENTRAL TX. THOUGH A ROGUE ISOLATED STRONG
STORM IS POSSIBLE NORTH OF I-20 THIS AFTERNOON...BETTER CHANCES
WILL LIKELY COME LATER TONIGHT. A SHORTWAVE OVER THE OK/TX
PANHANDLES WILL MOVE ESE TOWARD THE RED RIVER VALLEY AFTER MIDNIGHT.
A FEW STORMS WERE ALREADY POPPING ACROSS CENTRAL AND NORTHERN OK.
HIGH RESOLUTION HRRR/ARW-EAST/TEXAS TECH WRF MODELS ALL SHOW
CURRENT ISOLATED STORMS OVER NW OK INCREASING IN COVERAGE IN A
WEST-EAST LINE THIS EVENING...THEN DIVING SOUTHEAST TOWARD THE RED
RIVER LATE TONIGHT. TIMING THE LINEAR MCS TONIGHT IS SOMEWHAT
PROBLEMATIC HOWEVER AS THE HRRR IS MUCH FASTER THAN THE OTHER TWO
MODELS IN BRINGING ACTIVITY INTO THE RED RIVER VALLEY. CONSIDERING
WHERE THIS ACTIVITY IS FORMING AT THE MOMENT...WILL GO WITH THE
SLOWER TIMING MOSTLY BETWEEN MIDNIGHT AND SUNRISE MONDAY MORNING.
POPS WILL VARY FROM 50 PERCENT ACROSS THE IMMEDIATE RED RIVER AREA
TO AROUND 20 PERCENT ACROSS THE I-20 CORRIDOR. THE LINEAR MCS
SHOULD WEAKEN WITH THE VEERING/WEAKENING OF A 30-35KT NOCTURNAL
LLJ NEAR SUNRISE MONDAY MORNING.
THE FORECAST FOR LATER MONDAY AND THROUGH EARLY WEDNESDAY BECOMES A
BIT MORE DIFFICULT DUE TO THE UPPER RIDGE ANCHORED OVER SOUTH AND
CENTRAL TX AND WHERE ANY OUTFLOW BOUNDARIES SET UP ACROSS THE
NORTH. HAVE LINGERED BEST CHANCES AFTER SUNRISE MONDAY ACROSS THE
NORTHEAST COUNTIES WITH THE WEAKENING COMPLEX AND A SHORTWAVE
PASSING SOUTHEAST OVER ARKANSAS. LOW CHANCES LOOK PRUDENT FOR THE
AFTERNOON HOURS NEAR ANY OUTFLOWS ACROSS THE NORTHERN HALF OF THE
CWA. BY MONDAY NIGHT...ANOTHER SHORTWAVE DISTURBANCE MOVES EAST
FROM WEST TX AND WILL CARRY HIGHER CHANCES ACROSS THE WESTERN
COUNTIES BY MONDAY EVENING. THIS SYSTEM SHOULD WEAKEN AS IT HITS
THE RIDGE OVERNIGHT AND INTO TUESDAY MORNING. ON MORE SHORTWAVE
WILL TRANSITION SOUTHEAST OVER THE TOP OF THE UPPER RIDGE AND
TOWARD OUR OLD OUTFLOW BOUNDARY OVER THE NORTHERN COUNTIES WITH
ISOLATED TO SCATTERED STORMS FOR THE PM HOURS ONCE AGAIN. FEEL THE
UPPER RIDGE WILL KEEP AREAS FROM WACO AND ATHENS SOUTHWARD MAINLY
CAPPED AND DRY...THOUGH A ROGUE SHOWER CANNOT BE COMPLETELY RULED
OUT OVER OUR CENTRAL TX COUNTIES.
THE UPPER RIDGE EXPANDS NORTHWARD OVER NORTH TEXAS WEDNESDAY AS AN
UPPER LOW AND ASSOCIATED LONGWAVE TROUGH DEEPEN ACROSS THE WESTERN
U.S. HAVE LINGERED LOW RAIN CHANCES ACROSS THE FAR NORTHEAST CWA
WHERE SOME WEAKNESS ALOFT WILL REMAIN...BUT CONFIDENCE WILL BE
WANING BY THEN ON RAIN CHANCES. SUBSIDENCE AND DRY/HOT WEATHER
TAKE HOLD THE LATTER HALF OF THE WEEK INTO NEXT WEEKEND WITH RAIN
CHANCES NEAR ZERO. HIGHS WILL RISE INTO THE UPPER 90S AND 100 BY
FRIDAY AND SATURDAY...ESPECIALLY ACROSS THE WESTERN COUNTIES BY
NEXT WEEKEND.
05/
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 77 93 75 89 75 / 20 20 30 30 20
WACO, TX 75 95 75 92 75 / 5 0 20 10 10
PARIS, TX 74 90 72 87 71 / 50 50 20 40 40
DENTON, TX 76 91 73 88 73 / 30 30 30 40 30
MCKINNEY, TX 75 92 72 88 72 / 30 30 20 40 30
DALLAS, TX 77 94 75 89 76 / 20 20 20 30 20
TERRELL, TX 75 93 74 89 73 / 20 20 20 30 20
CORSICANA, TX 75 95 74 91 74 / 5 5 20 10 10
TEMPLE, TX 75 96 73 93 73 / 5 0 10 10 10
MINERAL WELLS, TX 75 93 73 89 71 / 30 20 40 30 20
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
649 PM CDT SUN JUN 16 2013
.AVIATION...
DIFFICULT CONVECTIVE FORECAST DURING THE NEXT 12 HOURS DUE TO
DIFFERING MODEL OUTPUT AND CONVECTION LARGELY DRIVEN BY MESOSCALE
PROCESSES. CONVECTION WILL BE MOVING TOWARD THE REGION IN NW FLOW
ALOFT...BUT WHETHER THERE IS THE SUPPORT FOR IT TO HOLD TOGETHER
LONG ENOUGH TO IMPACT THE TAF SITES IS A BIT MORE IN QUESTION.
AIRMASS OVER THE REGION IS NOT ESPECIALLY FAVORABLE
THERMODYNAMICALLY...NOR ARE THE LOW LEVEL WIND FIELDS VERY
IMPRESSIVE FOR A GOOD MCS PROPAGATION EVENT. NONETHELESS MODELS
ARE SHOWING TWO WINDOWS OF POSSIBLE CONVECTIVE ACTIVITY IN NORTH
TEXAS.
THE FIRST ONE WOULD BE LATE EVENING FROM 4Z-8Z AS ADVERTISED BY
THE RUC/4KMWRF/NAM AND PREVIOUS RUNS OF THE HRRR...WHICH TAKE
CURRENT CONVECTION IN OKLAHOMA AND GROW IT UPSCALE DURING THE
NEXT 2 HOURS AND PUSH IT INTO THE METROPLEX BEFORE MIDNIGHT LOCAL.
CURRENT RADAR TRENDS TO OUR NORTH DO NOT SEEM TO SUPPORT THIS IDEA
WITH CONVECTION REMAINING A BIT TOO ISOLATED FOR GOOD COLD POOL
DEVELOPMENT. THESE MODELS CAN HAVE ISSUES WITH OVER-ESTIMATING THE
INFLUENCE OF OUTFLOWS ENHANCING CONVECTION AND ITS PROPAGATION.
WILL NOT MENTION VCTS FOR THIS THREAT WINDOW BUT WILL CONTINUE TO
MONITOR TRENDS DURING THE NEXT COUPLE OF HOURS AND JUMP ON IT IF
ACTIVITY CAN INCREASE IN COVERAGE BETWEEN OKC-FDR.
THE SECOND WINDOW OF CONVECTIVE OPPORTUNITY WILL BE FROM 10Z TO
14Z FROM CONVECTION NOW FORMING IN COLORADO. THIS HAS A BETTER
SHOT TO MAKE IT INTO THE AREA...AS IT WILL BE SUPPORTED BY LIFT
FROM A SHORTWAVE TROUGH. THE LATEST RUN OF THE HRRR AND A HI-RES
WRF ARE HITTING ON THIS POTENTIAL WITH A DECAYING MCS ARRIVING
NEAR OR JUST BEFORE SUNRISE. AM ALMOST READY TO INCLUDE VCTS IN
TAFS FROM 10Z-13Z...BUT WILL WAIT TO SEE HOW CONVECTION EVOLVES IN
THE HIGH PLAINS AND WHETHER THE FIRST POSSIBLE ROUND OF CONVECTION
NOW OVER OKLAHOMA DOES IN FACT STEAL THE SHOW.
SO IN SUMMARY NO CHANGES WITH THE 00Z TAF ISSUANCE JUST YET...BUT
AMENDMENTS FOR A WINDOW OF VCTS LOOK LIKELY IN THE NEXT 2-3
HOURS.
TR.92
&&
.PREV DISCUSSION... /ISSUED 251 PM CDT SUN JUN 16 2013/
A LESS ACTIVE AFTERNOON TODAY VERSUS THIS TIME YESTERDAY WITH THE
OLD UPPER TROUGH NOW LONG GONE AND AN UPPER RIDGE THAT HAS EXPANDED
WESTWARD ACROSS SOUTH/CENTRAL TX. THOUGH A ROGUE ISOLATED STRONG
STORM IS POSSIBLE NORTH OF I-20 THIS AFTERNOON...BETTER CHANCES
WILL LIKELY COME LATER TONIGHT. A SHORTWAVE OVER THE OK/TX
PANHANDLES WILL MOVE ESE TOWARD THE RED RIVER VALLEY AFTER MIDNIGHT.
A FEW STORMS WERE ALREADY POPPING ACROSS CENTRAL AND NORTHERN OK.
HIGH RESOLUTION HRRR/ARW-EAST/TEXAS TECH WRF MODELS ALL SHOW
CURRENT ISOLATED STORMS OVER NW OK INCREASING IN COVERAGE IN A
WEST-EAST LINE THIS EVENING...THEN DIVING SOUTHEAST TOWARD THE RED
RIVER LATE TONIGHT. TIMING THE LINEAR MCS TONIGHT IS SOMEWHAT
PROBLEMATIC HOWEVER AS THE HRRR IS MUCH FASTER THAN THE OTHER TWO
MODELS IN BRINGING ACTIVITY INTO THE RED RIVER VALLEY. CONSIDERING
WHERE THIS ACTIVITY IS FORMING AT THE MOMENT...WILL GO WITH THE
SLOWER TIMING MOSTLY BETWEEN MIDNIGHT AND SUNRISE MONDAY MORNING.
POPS WILL VARY FROM 50 PERCENT ACROSS THE IMMEDIATE RED RIVER AREA
TO AROUND 20 PERCENT ACROSS THE I-20 CORRIDOR. THE LINEAR MCS
SHOULD WEAKEN WITH THE VEERING/WEAKENING OF A 30-35KT NOCTURNAL
LLJ NEAR SUNRISE MONDAY MORNING.
THE FORECAST FOR LATER MONDAY AND THROUGH EARLY WEDNESDAY BECOMES A
BIT MORE DIFFICULT DUE TO THE UPPER RIDGE ANCHORED OVER SOUTH AND
CENTRAL TX AND WHERE ANY OUTFLOW BOUNDARIES SET UP ACROSS THE
NORTH. HAVE LINGERED BEST CHANCES AFTER SUNRISE MONDAY ACROSS THE
NORTHEAST COUNTIES WITH THE WEAKENING COMPLEX AND A SHORTWAVE
PASSING SOUTHEAST OVER ARKANSAS. LOW CHANCES LOOK PRUDENT FOR THE
AFTERNOON HOURS NEAR ANY OUTFLOWS ACROSS THE NORTHERN HALF OF THE
CWA. BY MONDAY NIGHT...ANOTHER SHORTWAVE DISTURBANCE MOVES EAST
FROM WEST TX AND WILL CARRY HIGHER CHANCES ACROSS THE WESTERN
COUNTIES BY MONDAY EVENING. THIS SYSTEM SHOULD WEAKEN AS IT HITS
THE RIDGE OVERNIGHT AND INTO TUESDAY MORNING. ON MORE SHORTWAVE
WILL TRANSITION SOUTHEAST OVER THE TOP OF THE UPPER RIDGE AND
TOWARD OUR OLD OUTFLOW BOUNDARY OVER THE NORTHERN COUNTIES WITH
ISOLATED TO SCATTERED STORMS FOR THE PM HOURS ONCE AGAIN. FEEL THE
UPPER RIDGE WILL KEEP AREAS FROM WACO AND ATHENS SOUTHWARD MAINLY
CAPPED AND DRY...THOUGH A ROGUE SHOWER CANNOT BE COMPLETELY RULED
OUT OVER OUR CENTRAL TX COUNTIES.
THE UPPER RIDGE EXPANDS NORTHWARD OVER NORTH TEXAS WEDNESDAY AS AN
UPPER LOW AND ASSOCIATED LONGWAVE TROUGH DEEPEN ACROSS THE WESTERN
U.S. HAVE LINGERED LOW RAIN CHANCES ACROSS THE FAR NORTHEAST CWA
WHERE SOME WEAKNESS ALOFT WILL REMAIN...BUT CONFIDENCE WILL BE
WANING BY THEN ON RAIN CHANCES. SUBSIDENCE AND DRY/HOT WEATHER
TAKE HOLD THE LATTER HALF OF THE WEEK INTO NEXT WEEKEND WITH RAIN
CHANCES NEAR ZERO. HIGHS WILL RISE INTO THE UPPER 90S AND 100 BY
FRIDAY AND SATURDAY...ESPECIALLY ACROSS THE WESTERN COUNTIES BY
NEXT WEEKEND.
05/
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 77 93 75 89 75 / 20 20 30 30 20
WACO, TX 75 95 75 92 75 / 5 0 20 10 10
PARIS, TX 74 90 72 87 71 / 50 50 20 40 40
DENTON, TX 76 91 73 88 73 / 30 30 30 40 30
MCKINNEY, TX 75 92 72 88 72 / 30 30 20 40 30
DALLAS, TX 77 94 75 89 76 / 20 20 20 30 20
TERRELL, TX 75 93 74 89 73 / 20 20 20 30 20
CORSICANA, TX 75 95 74 91 74 / 5 5 20 10 10
TEMPLE, TX 75 96 73 93 73 / 5 0 10 10 10
MINERAL WELLS, TX 75 93 73 89 71 / 30 20 40 30 20
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
506 AM EDT Mon Jun 17 2013
...UPDATED FOR AVIATION DISCUSSION...
.NEAR TERM [Today]...
The large scale longwave pattern is highlighted by an elongated
ridge over the Nrn Gulf of Mex with high centered over W/Cntrl Gulf.
North of this ridge axis, exists moist quasi-zonal flow across SE
region and into the Wrn Atlc. However, a series of embedded short-
waves will continue to ride Ewd in this flow. During the predawn
hours, latest satellite imagery shows lead impulse over NW GA thru
S/Cntrl AL and into Gulf of Mex. At surface, Atlc high well east of
Carolinas with ridge axis WSW across Nrn Gulf region. Approaching
impulse continues to shunt surface ridge SEWD resulting in a
moistening up of deep layer moisture underneath the zonal flow
including a veering of low level flow. All this reflected in area
model soundings. i.e. GFS TAE with PWATS increasing from 1.38 to
1.92 inches from 12z Mon to 00z Tues, also 24 hr comparisons show
dew points running 4 to 9 degrees higher than same time yesterday
with models showing a return to inland aftn dewpoints around 70
degrees. With moist near surface conditions from recent rains,
patchy light fog or stratus may persist past sunrise.
RAP shows that shortwave will move ewd across FL/AL then FL/GA
border area during the late morning into the aftn. At surface, deep
WSW steering flow will drive Gulf seabreeze inland into late aftn
and to I-10 and beyond during eve. So models to show that the
juxtaposition of passing shortwave and lifting seabreeze plus any
convection that develops along mesoscale boundaries will generate a
good chance of storms today. HI RES guidance like WRF and NM4 imply
that focus should be across SE AL and Nrn tier GA counties in the
late aftn into eve when closest to seabreeze and when impulse
providing best lift. Strong to isold severe storms possible but any
severe threat should remain isolated and brief pulsy as is typical
for summer. i.e. RAP 21z Mon for SE AL with good cape 3200 J/KG but
0-6km shear only 20kts, BRN shear only 20 m/s and 700-500mb lapse
rate of 6c/km. Will go with sharp 60-10% NW-SE pop gradient. Expect
inland highs in the low 90s.
&&
.SHORT TERM [Tonight Through Tuesday Night]...
A broad low amplitude upper level trough over the eastern CONUS
will gradually deepen as a series of impulses eject out of the
Plains. Deep layer moisture will be on increase and a cold front
will drop down into northern AL/GA by 00z Wednesday. The deepest
moisture and best upper level support will be over the northern
portions of the forecast area. PoPs on Tuesday will be tapered from
good chance/likely for our AL and most Georgia zones with chances
PoPs for all Florida zones (30-40%) except the southeast Big Bend
(20%). Expect slight to chance PoPs for the nighttime periods. Max
and min temps will remain near seasonal averages.
&&
.LONG TERM [Wednesday through Sunday]...
A fairly seasonal period is expected with scattered afternoon and
evening convection each day. Some days will likely have slightly
higher PoPs than others depending on the timing of individual weak
shortwaves, which is hard to forecast in the long term. No major
synoptic scale system are expected to impact the area during the
period. Temperatures are expected to remain near their seasonal
averages.
&&
.AVIATION [Through 12z Tuesday]...
Expect MVFR ceilings/vsbys in fog to settle in briefly rest of
predawn hoUrs. Brief IFR possible around sunrise especially at TLH
and also at DHN and VLD. Conditions should improve to VFR after 14z.
Showers and thunderstorms starting in the late morning/early
afternoon and all sites will include VCTS with prob30 TSRA at DHN
and ABY 20Z-24Z. Winds will be from the southeast around 5-10 kts
becoming light southwest after sundown. After 08z, expect MVFR CIGS
and possibly VSBYS to redevelop especially across VLD and TLH.
IFR CIGS remain possible exepcially at VLD near sunrise.
&&
.MARINE...
The subtropical ridge will be the dominant feature across the
northern Gulf of Mexico this week, yielding mainly light southwest
to west flow and low seas.
&&
.FIRE WEATHER...
Red Flag conditions are not expected thru the work week as RH values
remain above critical levels. The combination of deep mixing and
somewhat stronger winds aloft will help dispersion values climb
above 75 Tues afternoon.]
&&
.HYDROLOGY...
River gauges are expected to remain below flood stage for at least
the next several days.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 91 72 92 72 92 / 30 20 40 20 40
Panama City 87 75 90 75 87 / 40 20 30 20 40
Dothan 91 72 91 73 91 / 50 40 60 30 40
Albany 92 73 91 72 92 / 50 40 60 30 50
Valdosta 91 71 92 72 92 / 40 30 40 30 40
Cross City 92 69 92 71 91 / 10 20 20 20 20
Apalachicola 86 75 88 76 86 / 20 10 20 10 40
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
SHORT TERM...Barry
MARINE...Barry/DVD
NEAR TERM/AVIATION/FIRE WEATHER...Block
LONG TERM/HYDROLOGY...DVD
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
347 AM EDT Mon Jun 17 2013
.NEAR TERM [Today]...
The large scale longwave pattern is highlighted by an upper ridge
moving slowly ewd across Rockies, an elongated ridge over the Nrn
Gulf of Mex with high centered over W/Cntrl Gulf, and north of this
ridge axis, a moist quasi-zonal flow across SE region and into the
Wrn Atlc. A series of embedded impulses will continue to ride Ewd in
this flow. Lead vort moving into Cntrl AL during pre-dawn hours
spawning active convection across Cntrl GA but should remain well
north of our area. At surface, Atlc high well east of Carolinas with
ridge axis WSW across Nrn Gulf region. With moist near surface
conditions from recent rains, patchy light fog or stratus may
persist past sunrise.
RAP shows another shortwave moving from Cntrl MS to Cntrl AL later
today with vort lobe brushing our area in late aftn. At surface,
Gulf seabreeze again expected to push Nwd into late aftn and eve. So
models continue to show a moistening up of deep layer moisture
underneath the zonal flow. All this reflected in area model
soundings. i.e. GFS TAE with PWATS increasing from 1.38 to 1.92
inches from 12z Mon to 00z Tues, also 24 hr comparisons show dew
points running 4 to 9 degrees higher than same time yesterday with
models showing a return to inland aftn dewpoints around 70 degrees.
The juxtaposition of passing impulse and lifting seabreeze plus any
convection that develops along mesoscale boundaries will generate a
good chance of storms today. HI RES guidance like WRF and NM4 imply
that focus should be across SE AL and adjacent SW GA counties in the
late aftn into eve when closest to seabreeze and when impulse
providing best lift. Strong to isold severe storms possible but
any severe threat should remain isolated and brief pulsy as is
typical for summer. i.e. RAP 21z Mon for SE AL with good cape 3200
J/KG but 0-6km shear only 20kts, BRN shear only 20 m/s and 700-500mb
lapse rate of 6c/km. Will go with sharp 60-10% NW-SE pop gradient.
Expect inland highs in the low 90s.
&&
.SHORT TERM [Tonight Through Tuesday Night]...
A broad low amplitude upper level trough over the eastern CONUS
will gradually deepen as a series of impulses eject out of the
Plains. Deep layer moisture will be on increase and a cold front
will drop down into northern AL/GA by 00z Wednesday. The deepest
moisture and best upper level support will be over the northern
portions of the forecast area. PoPs on Tuesday will be tapered from
good chance/likely for our AL and most Georgia zones with chances
PoPs for all Florida zones (30-40%) except the southeast Big Bend
(20%). Expect slight to chance PoPs for the nighttime periods. Max
and min temps will remain near seasonal averages.
&&
.LONG TERM [Wednesday through Sunday]...
A fairly seasonal period is expected with scattered afternoon and
evening convection each day. Some days will likely have slightly
higher PoPs than others depending on the timing of individual weak
shortwaves, which is hard to forecast in the long term. No major
synoptic scale system are expected to impact the area during the
period. Temperatures are expected to remain near their seasonal
averages.
&&
.AVIATION [Through 06z Tuesday]...
Expect MVFR ceilings/vsbys in fog to settle in briefly around
09-11Z. Brief IFR possible around sunrise especially at TLH and also
at DHN and VLD. Conditions should improve to VFR after 14z. Showers
and thunderstorms starting in the late morning/early afternoon and
all sites will include VCTS with prob30 TSRA at DHN and ABY
20Z-24Z. Winds will be from the southeast around 5-10 kts becoming
light southwest after sundown.
&&
.MARINE...
The subtropical ridge will be the dominant feature across the
northern Gulf of Mexico this week, yielding mainly light southwest
to west flow and low seas.
&&
.FIRE WEATHER...
Red Flag conditions are not expected thru the work week as RH values
remain above critical levels. The combination of deep mixing and
somewhat stronger winds aloft will help dispersion values climb
above 75 Tues afternoon.]
&&
.HYDROLOGY...
River gauges are expected to remain below flood stage for at least
the next several days.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 91 72 92 72 92 / 30 20 40 20 40
Panama City 87 75 90 75 87 / 40 20 30 20 40
Dothan 91 72 91 73 91 / 50 40 60 30 40
Albany 92 73 91 72 92 / 50 40 60 30 50
Valdosta 91 71 92 72 92 / 40 30 40 30 40
Cross City 92 69 92 71 91 / 10 20 20 20 20
Apalachicola 86 75 88 76 86 / 20 10 20 10 40
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
SHORT TERM...Barry
MARINE...Barry/DVD
NEAR TERM/AVIATION/FIRE WEATHER...Block
LONG TERM/HYDROLOGY...DVD
AREA FORECAST DISCUSSION
NWS LINCOLN IL
252 AM CDT MON JUN 17 2013
.DISCUSSION...
ISSUED 252 AM CDT MON JUN 17 2013
SHORT TERM...TODAY THROUGH WEDNESDAY
VERY WEAK SURFACE BOUNDARY EXTENDING ACROSS SOUTH-CENTRAL ILLINOIS
WILL BE THE PRIMARY FOCUSING MECHANISM FOR SCATTERED THUNDERSTORMS
TODAY. WITH ONE UPPER-WAVE PASSING WELL TO THE NORTH ACROSS THE
GREAT LAKES AND ANOTHER TRACKING TO THE S/SW INTO THE LOWER OHIO
RIVER VALLEY...VERY LITTLE UPPER SUPPORT WILL BE IN PLACE FOR
WIDESPREAD CONVECTION ACROSS CENTRAL ILLINOIS. DESPITE LACK OF
UPPER DYNAMICS...VERY MOIST AIRMASS IN PRESENCE OF WEAK SURFACE
FORCING WILL BE ENOUGH TO TRIGGER A FEW SHOWERS/THUNDERSTORMS
LATER TODAY. HRRR SUGGESTS DEVELOPMENT AROUND MIDDAY...ESPECIALLY
IN CLOSER PROXIMITY TO BOUNDARY. WILL THEREFORE INCLUDE LOW CHANCE
POPS TODAY...WITH BEST RAIN CHANCES SOUTH OF I-72.
SHORT-WAVE TROUGH CURRENTLY EVIDENT ON WATER VAPOR IMAGERY OVER
SOUTHERN SASKATCHEWAN MAY PROVIDE A NEW WRINKLE IN THE FORECAST
FOR TUESDAY. WHILE WE PREVIOUSLY THOUGHT TUESDAY WOULD BE
DRY...LATEST MODEL GUIDANCE IS INDICATING THE POTENTIAL FOR
ISOLATED CONVECTION DURING THE AFTERNOON. THANKS TO A CONTINUED
MOIST AIRMASS AND THE ARRIVAL OF MODEST UPPER FORCING DURING PEAK
HEATING...HAVE INCLUDED A SLIGHT CHANCE FOR THUNDER TUESDAY
AFTERNOON. ONCE THE WAVE PUSHES FURTHER EAST...SURFACE HIGH
PRESSURE WILL BUILD INTO THE REGION FOR TUESDAY NIGHT AND
WEDNESDAY...PROVIDING SEASONABLY WARM AND DRY CONDITIONS.
LONG TERM...THURSDAY THROUGH SUNDAY
00Z 17 JUN MODELS CONTINUE TO SUGGEST A VERY WARM AND LARGELY DRY
EXTENDED FORECAST. ALL MODELS BUILD AN UPPER-LEVEL RIDGE ACROSS
THE PLAINS ON THURSDAY...THEN SHIFT IT INTO THE MIDWEST OVER THE
WEEKEND. PREVIOUS RUNS DISAGREED ON THE EXACT STRENGTH/POSITIONING
OF THE RIDGE...WHICH BROUGHT INTO QUESTION WHETHER ANY MCS
ACTIVITY COULD RIDE UP/OVER THE RIDGE INTO THE AREA DURING THE
PERIOD. LATEST GFS/ECMWF/GEM ARE ALL LOOKING STRONGER WITH THE
RIDGING...KEEPING BEST FORCING FOR NOCTURNAL MCS DEVELOPMENT
FURTHER NORTH ACROSS THE UPPER MIDWEST INTO THE GREAT LAKES. MODELS
INDICATE ONE CONVECTIVE COMPLEX MAY BRUSH THE KILX CWA TO THE
NORTH FRIDAY NIGHT...BEFORE RIDGE BUILDS EVEN FURTHER ON SATURDAY.
HAVE THEREFORE INCLUDED CHANCE POPS ALONG AND NORTH OF A CANTON TO
BLOOMINGTON LINE FRIDAY NIGHT...BUT HAVE GONE WITH A DRY FORECAST
ACROSS THE BOARD FOR THE REMAINDER OF THE EXTENDED. WILL LIKELY
HAVE TO WAIT UNTIL RIDGE BEGINS TO FLATTEN EARLY NEXT WEEK BEFORE
ANY WIDESPREAD RAIN CHANCES RETURN TO THE AREA. GIVEN BUILDING
UPPER HEIGHTS AND LACK OF CONVECTION...HIGH TEMPERATURES WILL
REACH THE UPPER 80S/LOWER 90S WHILE OVERNIGHT LOWS ONLY DROP INTO
THE LOWER 70S FRIDAY THROUGH SUNDAY.
BARNES
&&
.AVIATION...
ISSUED 1150 PM CDT SUN JUN 16 2013
FOG HAS ALREADY STARTED TO DEVELOP ACROSS THE AREA AND CMI IS
ALREADY AT 4SM. BELIEVE THIS WILL CONTINUE AND AM EXPECTING THE
REMAINDER OF THE TAF SITES TO HAVE MVFR VIS STARTING AT 06Z OR
SHORTLY THEREAFTER. THIS MVFR VIS WILL LIKELY HOLD TIL CLOSE TO
SUNRISE AND THEN ALL TAF SITES WILL SEE TEMPO VIS DOWN TO IFR OF
1-2SM. AFTER SUNRISE FOG WILL DISSIPATE QUICKLY AND NOT EXPECTING
ANY VIS ISSUES REMAINDER OF THE TAF PERIOD. HIGH CIRRUS WILL BE
THE ONLY CLOUD AROUND OVERNIGHT. THEN CU WILL DEVELOP TOMORROW
MORNING AT AROUND 4-5KFT AND THEN DISSIPATE AROUND
SUNSET...LEAVING CLEAR SKIES TOMORROW EVENING. WINDS WILL BE LIGHT
OVERNIGHT AND THEN WESTERLY TOMORROW...LESS THAN 10KTS. THEN LIGHT
OUT OF THE WEST AGAIN TOMORROW EVENING.
AUTEN
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
1246 AM CDT MON JUN 17 2013
.UPDATE...
ISSUED AT 718 PM CDT SUN JUN 16 2013
SVR TSRA THAT WERE PROLIFIC GOLFBALL-SIZED HAIL PRODUCERS OVER COWLEY
COUNTY HAVE DISSIPATED BUT HAVE ALSO UNLEASHED A W-NW MOVG OUTFLOW
BOUNDARY ACROSS SUMNER & HARPER COUNTIES & TOWARD KICT. A CELLS HAVE
DEVELOPED E OF THE OUTFLOW. ISOLD CELLS HAVE ALSO DEVELOPED OVER THE
SE CORNER OF KS AS WELL AS OVER EC KS. MID-LVL FLOW IS VERY WEAK & AS
SUCH FAVORS A RATHER CHAOTIC CONVECTIVE "PATTERN" FOR THE REST OF THE
EVENING. HAVE TEMPORARILY ASSIGNED 40-50% TSRA TO EXTREME SC-SE KS
WITH SHARP POP-GRADIENT N TOWARD KS TURNPIKE TIL 10 PM. HAVE ALSO
ADJUSTED TSRA PROBABILITIES FOR LATER THIS EVENING TO REFLECT ONSET OF
MCS THAT`LL SURGE SE TOWARD...THEN ACROSS...PRIMARILY SC KS. POP GAME
PLAN FROM MID-NGT TO 7 AM APPEARS ON TARGET. MADE MINOR ADJUSTMENTS TO
SKY GRIDS FOR EARLY THIS EVENING.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 311 PM CDT SUN JUN 16 2013
A RATHER COMPLICATED SCENARIO IS UNDERWAY ACROSS THE CENTRAL PLAINS
THIS AFTERNOON. AN OUTFLOW BOUNDARY WAS LOCATED ACROSS CENTRAL
KANSAS FROM NEAR KHUT EXTENDING NORTH AND WEST TOWARD NORTON KANSAS
AT 2 PM CDT. CU HAS DEVELOPED ON THE COOL SIDE OF THIS OUTFLOW
BOUNDARY WHILE THE OPERATIONAL ECM RAP SHOWS MINIMAL CINH WITHIN AN
AXIS OF 2000-2500 J/KG. THIS BOUNDARY MAY BECOME A FOCUS FOR DEEP
MOIST CONVECTION BY LATE AFTERNOON. ANOTHER DIFFUSE OUTFLOW BOUNDARY
WAS SITUATED NEAR THE OKLAHOMA STATE LINE WHERE WIDELY SCATTERED
SHOWERS AND THUNDERSTORMS WILL REMAIN POSSIBLE ESPECIALLY SOUTH OF
THE STATE LINE. FURTHER NORTH AND WEST ANOTHER OUTFLOW BOUNDARY WAS
SURGING SOUTH ACROSS WESTERN NEBRASKA WHILE HIGH-BASED THUNDERSTORMS
WERE DEVELOPING ACROSS THE FRONT RANGE DOWNSTREAM OF A PV ANOMALY
TRANSLATING EASTWARD ACROSS THE CENTRAL ROCKIES. THE LATEST 12Z
SUITE OF MODEL DATA HAS SHIFTED THE QPF AXIS A BIT FURTHER WEST
TONIGHT...HOWEVER THIS AREA REMAINS OVERTURNED FROM DEEP MOIST CONVECTION
LAST NIGHT/EARLY TODAY. ANY ACTIVITY DEVELOPING ALONG THE OUTFLOW
BOUNDARY ACROSS CENTRAL KANSAS WOULD BE STEERED TOWARD SOUTH CENTRAL
KANSAS THIS EVENING WHILE ANOTHER LINE OF SHOWERS AND THUNDERSTORMS
MAY PROPAGATE SOUTHEASTWARD OFF THE HIGH PLAINS OF WESTERN KANSAS
LATE TONIGHT WHILE MERGING WITH THE ACTIVITY DRIFTING SOUTH OUT OF
NEBRASKA. WILL MAINTAIN HIGH POPS ACROSS MUCH OF CENTRAL/SOUTH
CENTRAL KANSAS TONIGHT WHILE THE THREAT FOR FLOODING OVER SOUTHEAST
KANSAS APPEARS TO HAVE DIMINISHED SLIGHTLY...HOWEVER NO PLANS TO
REMOVE THE FLOOD WATCH AT THIS TIME GIVEN RAINFALL AMOUNTS BETWEEN
2-3 INCHES A FEW LOCATIONS.
MAINTAINED POPS ACROSS MAINLY SOUTHEAST KANSAS THROUGH EARLY
AFTERNOON ON MONDAY WITH SOME TIMING DIFFERENCES...HOWEVER BY LATE
AFTERNOON TEMPERATURES ARE EXPECTED RECOVER INTO THE LOW TO MID 80S
WITHIN A STABLE AIRMASS BEHIND THE DEPARTING MCS. THERE IS SOME
CONCERN FOR CONTINUED OVERNIGHT CONVECTION MOVING EASTWARD OFF THE
HIGH PLAINS MONDAY NIGHT AND AGAIN ON TUESDAY NIGHT ACROSS MAINLY
CENTRAL KANSAS. HOWEVER BETTER CHANCES FOR DEEP MOIST CONVECTION MAY
ARRIVE TOWARD THE MIDDLE OF THE WEEK AS A MORE ROBUST SHORTWAVE
TROUGH MOVES OVER THE CENTRAL AND NORTHERN PLAINS. SEASONABLE
TEMPERATURES ARE EXPECTED THROUGH THE PERIOD WITH HIGHS IN THE 80S
AND LOW IN THE 60S. -MCGUIRE
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 311 PM CDT SUN JUN 16 2013
LINGERING SHOWERS AND THUNDERSTORMS ARE POSSIBLE FOR THE EASTERN
THIRD OF KANSAS ON THURSDAY AS A SHORTWAVE EXITS THE AREA. A RIDGE
OVER THE CENTRAL U.S. WILL STAY PLANTED FOR MOST OF THIS TIME FRAME
WITHOUT A BREAKDOWN IN THE FLOW PATTERN UNTIL LATE IN THE WEEKEND
WHEN A TROUGH MOVES OVER THE NORTHERN U.S. THERE IS MODEL
DISAGREEMENT IN THE LOCATION AND TIMING OF A WAVE AHEAD OF THE MAIN
TROUGH. THUS ANY IMPACT TO THE AREA COULD ONLY BE CONSIDERED
PRELIMINARY AT THIS TIME. THE RIDGE IN PLACE WILL HELP SET THE STAGE
FOR TEMPERATURES CLIMBING ABOVE 90 ONCE MORE. -JUANITA
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1241 AM CDT MON JUN 17 2013
A SQUALL LINE OF THUNDERSTORMS WILL CONTINUE TO RACE EASTWARD
ACROSS THE REGION TONIGHT. DAMAGING WINDS OF 60 MPH FROM THE WEST
ARE EXPECTED WITH THIS LINE OF THUNDERSTORMS. CONDITIONS WILL
BEGIN TO IMPROVE ONCE THE LINE OF THUNDERSTORMS MOVES THROUGH THE
AREA WITH LIGHT EASTERLY WINDS DEVELOPING IN ITS WAKE.
JAKUB
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 64 84 65 84 / 10 10 10 40
HUTCHINSON 63 84 65 84 / 10 10 20 40
NEWTON 63 83 64 83 / 10 10 10 40
ELDORADO 63 83 64 83 / 10 10 10 30
WINFIELD-KWLD 65 84 66 85 / 10 10 10 40
RUSSELL 61 84 64 83 / 20 10 30 50
GREAT BEND 62 84 64 84 / 20 10 30 50
SALINA 62 84 64 83 / 10 10 20 40
MCPHERSON 62 83 64 83 / 10 10 20 40
COFFEYVILLE 65 85 66 85 / 10 10 0 30
CHANUTE 63 84 65 84 / 0 0 0 30
IOLA 62 83 64 83 / 0 0 0 30
PARSONS-KPPF 64 84 65 84 / 10 0 0 30
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH THROUGH THIS AFTERNOON FOR KSZ071-072-095-096-
098>100.
FLOOD WATCH THROUGH THIS AFTERNOON FOR KSZ094.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1141 PM CDT SUN JUN 16 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 326 PM CDT SUN JUN 16 2013
TRICKY FORECAST FOR THE FIRST 12-24 HOURS WITH MANY FACTORS IN PLAY
FOR CONVECTION POTENTIAL...AND DIFFERENCES IN GUIDANCE AS TO
HOW/WHERE/WHEN STORMS EVOLVE. CURRENTLY VERY LITTLE CIN OVER THE
FORECAST AREA WITH AN AREA OF GENERALLY 1500-2000J/KG CAPE BISECTING
THE FA FROM NW TO SE. BULK SHEAR HOWEVER IS QUITE LOW...LESS THAN
10KTS WITHIN THE FIRST 15KFT PER NAM SOUNDINGS. PER CU FIELD ON
VISIBLE AND WINDS IN OBS WOULD APPEAR THAT BOUNDARY HAS MADE IT
SOUTH OF EMPORIA...WITH SOME WEAK WIND CONVERGENCE JUST SOUTH. NOT
CONFIDENT OF DEVELOPMENT ON THIS BOUNDARY BUT WILL LEAVE A SLIGHT
CHANCE SOUTH AND WEST TO ACCOUNT FOR PROBABILITY.
STARTING TO SEE CONVECTION DEVELOP IN SW NEBRASKA AS WELL AS FAR SW
SOUTH DAKOTA AT THIS HOUR. MOISTURE AXIS AND CORFIDI VECTORS
INDICATE THESE STORMS WOULD MOVE TO THE EAST TO SOUTHEAST WITH
TIME...BECOMING A CLUSTER AND MOVING ACROSS WESTERN AND PORTIONS OF
CENTRAL KANSAS. HOW FAR EASTWARD THEY CAN DEVELOP IS IN
QUESTION...WITH THE NAM/GFS/EC TAKING THE BRUNT OF THE QPF MAINLY
WEST OF OUR FORECAST AREA. LAST FEW RUNS OF THE HRRR BRING A SQUALL
LINE ACROSS MUCH OF THE FORECAST AREA GENERALLY 9PM TO AFTER
MIDNIGHT. THINK THE EARLIER SCENARIO IS MORE LIKELY AND WILL TAKE
MOST OF THE LLJ ENERGY INTO THE WESTERNMOST STORM COMPLEX...THINKING
WON`T BE ABLE TO DEVELOP A LINE OF STORMS FURTHER EAST BACK TOWARD
THE COOLER AIR. ONCE AGAIN WILL GO WITH CHANCE POPS TO THE WEST AND
DECREASE CHANCES EAST...BUT NOT WILLING TO TAKE POPS OUT FAR EAST
JUST YET GIVEN MODEL DIFFERENCES. ENOUGH INSTABILITY WITH A LINE OF
STORMS TO MAKE WIND AND HEAVY RAIN A CONCERN...BUT SHEAR PROFILES
NOT AS FAVORABLE FOR LOW LEVEL ROTATION. STORMS MOVE EASTWARD
QUICKLY AND HAVE A DRY FORECAST ALL AREAS BY AFTERNOON. HAVE LOWS IN
THE 60S TONIGHT WITH HIGHS IN THE 80S ON MONDAY...COOLER SE WHERE
CLOUDS AND RAIN MAY LINGER A FEW HOURS INTO THE MORNING MONDAY. 67
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 326 PM CDT SUN JUN 16 2013
MID RANGE AND EXTENDED FORECAST (TUESDAY THROUGH SUNDAY)...
EXPECT LARGE SCALE RIDGING TO TAKE PLACE IN THE MID RANGE TO
EXTENDED PERIOD OF THE FORECAST...WHICH WILL LIKELY SPELL A
CONSISTENT PERIOD OF ABOVE NORMAL TEMPERATURES THROUGH THE END OF
THE WORK WEEK AND THROUGH NEXT THE WEEKEND. HIGHS WILL LIKELY
REACH THE MID TO UPPER 90S...HOWEVER AS THAT TIME PERIOD
APPROACHES AND MODELS CONTINUE CONSISTENCY IN BRINGING IN THE MID
LEVEL RIDGE PERHAPS WE COULD SEE TEMPERATURES LATE IN THE WEEK AND
THIS WEEKEND REACH THE TRIPLE DIGIT MARK...ESPECIALLY IN THE
WESTERN ZONES WHERE MOISTURE COULD BE A LITTLE HARDER TO COME BY.
PRECIP CHANCES THROUGH THE EXTENDED WILL BE TOUGH TO NAIL
DOWN...AS THERE ARE NO REAL STRONG MID LEVEL SIGNALS TO REALLY
TRACK FOR PRECIP. THE BEST CHANCE FOR PRECIP DOES LOOK LIKE IT
WILL TAKE PLACE IN THE MID TO LATE PART OF THE WEEK AS MODELS HINT
AT SOME STRONG CONVECTION TAKING PLACE OFF THE HIGH PLAINS...AND
DRAGGING THE CONVECTION EASTWARD THROUGH THE CENTRAL PLAINS. THE
POSITION OF THE MID LEVEL TROUGH AND THE SUBSEQUENT STEERING FLOW
WILL LIKELY DETERMINE THE EXACT TRACK OF THE PRECIP. SHOULD THE
RIDGE BECOME LESS AMPLIFIED THE W-SW STEERING FLOW MAY END UP OVER
THE FORECAST AREA...HOWEVER SHOULD THE RIDGE BE A LITTLE STRONGER
THAN ANTICIPATED IT WOULD SHUNT THE CONVECTION NORTH. EITHER
WAY...WILL MAINTAIN CHANCE POPS FOR THE WED NIGHT THROUGH FRIDAY
TIME FRAME FOR THESE SHOWERS. OTHERWISE...THE MAINLY DRY AND WARM
FORECAST DESCRIBED ABOVE WILL BE EXPECTED THROUGH THE EXTENDED.
JL
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1141 PM CDT SUN JUN 16 2013
FOR THE 06Z TAFS...TWO AREAS OF SHOWERS AND THUNDERSTORMS CONTINUED
TO DEVELOP ACROSS CENTRAL KANSAS...TRACKING SOUTH AND EAST INTO
SOUTHEASTERN KANSAS. AS THESE TWO AREAS MERGE TOGETHER...MAY SEE
MORE SCATTERED ACTIVITY OVER CENTRAL AND EAST CENTRAL KANSAS THROUGH
MONDAY MORNING. THERE IS SOME UNCERTAINTY REGARDING HOW LONG THIS
ACTIVITY WILL PERSIST INTO THE MORNING HOURS. DRY CONDITIONS
EXPECTED DURING THE AFTERNOON AND EVENING HOURS WITH LIGHT NORTHEASTERLY
WINDS.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...67
LONG TERM...LEIGHTON
AVIATION...HENNECKE
AREA FORECAST DISCUSSION
NWS CARIBOU ME
323 AM EDT MON JUN 17 2013
.SYNOPSIS...
LOW PRESSURE WILL CROSS THE REGION TODAY BRINGING A COLD FRONT ACROSS
THE AREA BY TONIGHT. A SECOND COLD FRONT IS EXPECTED TO CROSS THE
REGION ON TUESDAY WITH COOLER AIR TUESDAY NIGHT INTO WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
PROBLEM OF THE DAY WILL BE POTENTIAL FOR CONVECTION.
THE ATMOSPHERE IS STABLE W/STRATUS AND RAIN MOVING ACROSS THE
REGION EARLY THIS MORNING. STEADY RAINFALL HAS SHIFTED TO NERN
MAINE AND WESTERN NEW BRUNSWICK AS DEPICTED BY THE LATEST RADAR
MOSAIC. 00Z UA SHOWED A NICE JETLET AT 700MBS ENHANCING THE
RAINFALL. A FRONTAL BOUNDARY REMAINS IN PLACE ACROSS NORTH CENTRAL
MAINE W/AN AREA OF LOW PRES MOVING THROUGH NORTHERN AREAS AS OF
06Z. TEMPERATURES WERE HOLDING IN THE MID TO UPPER 50S ACROSS
CENTRAL AND DOWNEAST AREAS(SOUTH OF THE FRONT) AND IN THE UPPER
40S AND LOWER 50S ACROSS NORTHERN MAINE IN IN CLOSE PROXIMITY OF
THE FRONT. THE REGIONAL GEM AND RUC WERE HANDLING THIS LATEST
SITUATION THE BEST AND THIS HOW THE FORECAST WAS RUN THROUGH THIS
MORNING W/CLOUDS, WIDELY SCATTERED SHOWERS AND SOME FOG.
THINGS ARE EXPECTED TO CHANGE BY EARLY AFTERNOON AS THE FRONTAL
BOUNDARY LIFTS NORTH AND THE CWA GETS INTO A PSEUDO WARM SECTOR
AHEAD OF THE APCHG COLD FRONT. THIS WILL ALLOW FOR DESTABILIZATION
W/SOME SUNSHINE EXPECTED W/TEMPERATURES HITTING UPPER 60S TO LOWER 70S.
LLVLS WILL WARM AHEAD OF A PRE-FRONTAL BOUNDARY AID IN LLVL INSTABILITY.
ALOFT, THE AIRMASS WILL BE COLD ENOUGH W/MID LEVEL TEMPERATURES(700/500MBS)
RUNNING -2C/-19C RESPECTIVELY. MDL SOUNDINGS FROM THE NAM AND GFS
SUPPORT POSSIBLE TSTMS EARLY THIS AFTERNOON ACROSS THE NORTH AND
WESTERN AREAS W/SB CAPES OF 600-900J/KG W/THE GFS THE MOST AGGRESSIVE.
0-6KM BULK SHEAR IS FCST TO BE AROUND 35 KTS. 700-500MB LAPSE RATES
FCST TO BE 6.0-6.5 ACROSS THE NORTHERN 1/2 EARLY THIS AFTERNOON AND
CLOSE TO 7.0 C/KM ACROSS THE INTERIOR DOWNEAST BY MID/LATE AFTERNOON.
ENOUGH LLVL MOISTURE IN PLACE W/SOME DRYING IN THE MID LEVELS WILL
ADD TO THE MIX. THEREFORE, DECIDED TO ADD THE MENTION OF SMALL HAIL
AND GUSTY WINDS IN FOR TSTMS ACROSS THE AFOREMENTIONED AREAS. THE
ACTION WILL SHIFT TO THE CENTRAL AND INTERIOR DOWNEAST AREAS THIS
AFTERNOON AND CONTINUE INTO EARLY EVENING AS TEMPERATURES ARE FCST
TO WARM WELL INTO THE 70S AND DEWPOINTS CLIMB TO AROUND 60F. SW
WIND SHIFTING TO THE WEST THIS AFTERNOON WILL ERODE OUT THE STABLE
MARINE LAYER ALLOWING FOR FURTHER DESTABILIZATION. DECIDED TO
CARRY ENHANCED WORDING W/THE TSTMS INCLUDING THE BANGOR AND CALAIS
AREAS AND KEPT THE MENTION OF THUNDER OUT OF THE COAST DUE TO A
SOUTH FLOW HOLDING ON LONGER. QPF WILL BE A CHALLENGE DUE TO THE
EXPECTED CONVECTION. DECIDED ON A BLEND OF THE GEM/NAM12 AND GFS
AND MANUALLY ADJUSTED TO ACCOUNT TO 2 AREAS OF HEAVIER AMOUNTS(0.25")
W/ONE AREA ACROSS THE NORTH AND THE 2ND AREA OVER THE DOWNEAST REGION.
THINGS WILL WIND DOWN TONIGHT AS THE COLD FRONT CROSSES THE REGION
AS LOW PRES MOVES ACROSS SOUTHERN CANADA. SOME PARTIAL CLEARING IS
EXPECTED AND THIS WILL LEAD TO SOME FOG. ATTM, DECIDED TO STAY W/PATCHY
FOG. THE DAYCREW CAN ASSESS THIS FURTHER W/THE LATER MODEL RUNS. FOLLOWED
THE GEM AND NAM12 FOR TEMPERATURES/DEWPOINTS FOR TONIGHT.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
HIGH PRESSURE IS EXPECTED TO BUILD IN AT THE SURFACE AT THE
BEGINNING OF THIS PERIOD. AT THE SAME TIME AN UPPER LEVEL TROUGH
WILL APPROACH FROM THE WEST AND MOVE ACROSS THE REGION
WEDNESDAY...HOWEVER WITH DRY CONDITIONS WILL KEEP POPS LOW. HAVE
BLENDED THE GFS...SREF...NAM AND ECMWF FOR POP AND QPF GRIDS. WILL
USE A BLEND OF NAM12 AND GMOS FOR WINDS. FOR TEMPERATURE GRIDS WILL
INITIALIZE WITH GMOS AND WILL RAISE MINIMUM TEMPERATURE TWO
DEGREES BASED ON VERIFICATION. HAVE USED THE GEM FOR DEW POINT
GRIDS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
HIGH PRESSURE WILL CONTINUE TO BUILD IN FROM THE WEST AT THE
BEGINNING OF THIS PERIOD THEN CREST OVER THE REGION THURSDAY
MORNING. A COLD FRONT WILL APPROACH FROM THE NORTHWEST THURSDAY
NIGHT AND CROSS THE STATE FRIDAY. A FRONTAL SYSTEM WILL REMAIN
NEAR THE NORTHERN PORTION OF THE STATE LATE SATURDAY THROUGH
TUESDAY. HAVE USED THE GMOS TO INITIALIZE ALL GRIDS. WILL ADJUST
POP AND SKY GRIDS. HAVE ALSO ADJUSTED ALL MINIMUM TEMPERATURES
HIGHER AND TO BETTER FIT THREE HOUR GMOS.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
NEAR TERM: IFR/MVFR ACROSS THE REGION THIS MORNING. CONDITIONS
WILL IMPROVE TO VFR BY MID TO LATE MORNING. TSTMS ARE POSSIBLE
THIS AFTERNOON INTO EARLY EVENING AFFECTING THE TERMINALS. WIND
SHEAR AND SMALL WILL BE A CONCERN. DAYCREW WILL NEED TO MONITOR
FOR POSSIBLE AWW FOR BIA THIS AFTERNOON IF TSTMS FIRE.
SHORT TERM: EXPECT VFR CONDITIONS TUESDAY THROUGH FRIDAY.
&&
.MARINE...
NEAR TERM: NO HEADLINES FOR THIS TERM. WAVE HEIGHTS WERE ADJUSTED
TO BRING THEM UP A FOOT W/A FCST OF 5 FT BY THIS EVENING AS A SOUTHERLY
FETCH SETS W/A SWELL COMPONENT. WINDS WILL BE LIGHT AVERAGING SPEEDS
OF 10 KTS. DECIDED ON THE NAM12/GFS40 AND GEM FOR THE SUSTAINED WINDS.
SHORT TERM: FOR WINDS HAVE BLENDED THE NAM12 AND GFS40 AND WILL
USE 125 PERCENT OF THE MODEL BLEND FOR GUST SPEED. FOR WAVES:
EXPECT WINDS ACROSS LOCAL WATERS TO BE LIGHT THROUGH THIS PERIOD
SO LONG PERIOD WAVE WILL DOMINATE. EXPECT SOUTHERLY WAVE GROUP
2-3 FEET/8 SECONDS ACCOMPANIED BY SECONDARY SOUTHEAST GROUP 1-2
FEET/10 SECONDS.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HEWITT
SHORT TERM...MIGNONE
LONG TERM...MIGNONE
AVIATION...HEWITT/MIGNONE
MARINE...HEWITT/MIGNONE
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
453 AM EDT MON JUN 17 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 411 PM EDT SUN JUN 16 2013
THE MAIN CONCERN FOR THE SHORT TERM FORECAST WILL BE THE ONGOING
SHOWERS AND THUNDERSTORMS AND ADDITIONAL SHOWERS WITH THE TROUGH
DROPPING SOUTH ACROSS THE AREA TONIGHT. INITIAL CONVECTION WAS OVER
EASTERN UPPER MICHIGAN...WHERE THERE WAS INCREASED MOISTURE FROM THE
FOG EARLIER TODAY AND CONVERGENCE FROM WEAK LAKE BREEZES. THESE
INITIAL SHOWERS HAVE SHIFTED TO THE SOUTHEAST AND OUT OF THE
CWA...BUT ARE SEEING SOME SHOWERS IN CENTRAL UPPER MICHIGAN ALONG
THE LAKE SUPERIOR LAKE BREEZE. THESE SHOWERS HAVE BEEN LIMITED THUS
FAR DUE TO THE DRY MID LEVEL AIR EVEN THOUGH THERE IS STRONG
LOW LEVEL LAPSE RATES AND RAP ANALYZED SB CAPE VALUES OF
500-1000 J/KG. BUT WITH THE INVERTED V LOOK TO THE RAP
SOUNDINGS...ML CAPES ARE STRUGGLING TO GET MUCH ABOVE 250-500 J/KG.
THIS DRY AIR CAN ALSO BE SEEN IN THE DEWPOINTS /UPPER 40S/ AWAY
FROM THE INFLUENCE OF THE GREAT LAKES. THERE HAVE EVEN BEEN SOME
SIGNIFICANT JUMPS IN THE DEWPOINTS OVER THE EASTERN CWA...AS THE
LAKE BREEZES HAVE MOVED IN AND OUT OF SOME OF THE SITES. FARTHER
WEST...A PERSISTENT SHOWER/THUNDERSTORM CLUSTER MOVED INTO WESTERN
GOGEBIC COUNTY OVER THE LAST HOUR AND DID PRODUCE SOME GUSTS UP TO
40KTS EVEN THOUGH THE CLUSTER IS DIMINISHING. THIS ISN/T TOO
UNREASONABLE WITH CURRENT DCAPE VALUES OVER MUCH OF UPPER MICHIGAN
AROUND 800-1000 J/KG AND THE INVERTED V SOUNDINGS. WOULD EXPECT
THIS TO BE THE PRIMARY CONCERN FOR ANY SHOWERS/THUNDERSTORMS LATE
THIS AFTERNOON AND EVENING. FINALLY...ADDITIONAL
SHOWERS/THUNDERSTORMS HAVE BEEN ONGOING JUST NORTHEAST OF LAKE
SUPERIOR...DUE TO ONE PIECE OF SHEARED OFF UPPER LEVEL ENERGY
DROPPING SOUTHEAST ALONG THE TROUGH. THESE SHOWERS WILL CONTINUE
QUICKLY SOUTHEAST AS THE STORM MOTION IS AROUND 40KTS.
THE AREA THAT WILL BRING THE BEST CHANCE FOR SHOWERS IS THE
REMNANT SHORTWAVE FROM THE UPPER LOW THAT WAS IN CENTRAL
SASKATCHEWAN YESTERDAY. THIS SHORTWAVE HAS STARTED TO MOVE TOWARDS
THE CANADA/ND/MN BORDER AND HAS SPARKED SHOWERS AND THUNDERSTORMS
ALONG THE SURFACE TROUGH WHERE THERE IS DEEPER MOISTURE. WITH THE
STORM MOTION TO THE SOUTHEAST AROUND 30-35KTS AND THE TROUGH SLOWLY
SAGGING SOUTHEAST...WOULD EXPECT THOSE SHOWERS TO MOVE SOUTHEAST
ACROSS WESTERN/CENTRAL UPPER MICHIGAN LATE THIS AFTERNOON AND INTO
THE EVENING HOURS. NOT ENTIRELY CONFIDENT ON THE EASTERN CWA...AS
IT WILL DEPEND ON THE THUNDERSTORMS CURRENTLY MOVING SOUTHEAST
FROM THUNDER BAY AND HOW FAR SOUTHEAST THEY WILL MAKE IT BEFORE
DIMINISHING. WILL HAVE LOWER POPS THAN OVER THE WEST...BUT STILL
IN THE LOW END CHANCE CATEGORY. AN EARLIER UPDATE COVERED THE
TIMING WELL OVER THE WEST AND HAVE JUST MADE MINOR TWEAKS TO
MATCH THE CURRENT CONDITIONS...WITH MOST AREAS IN THE HIGHER REACHES
OF THE SCATTERED/CHANCE CATEGORY. THINK THERE IS A DECENT SHOT MOST
LOCATIONS WILL SEE RAIN...BUT THE COVERAGE/TIMING WOULD BE BETTER
REFLECTED IN THE SCATTERED WORDING. AS MENTIONED ABOVE...THE DRY
AIR AND LIMITED INSTABILITY WILL BE THE MAIN LIMITING FACTORS TO
THE THUNDERSTORMS AND THEIR SEVERE POTENTIAL. BEST THREAT WILL BE
WEST-SOUTHWEST OF THE CWA WHERE THE 850-700/500MB LAPSE RATES ARE
THE STEEPEST...BUT THERE COULD BE SOME STRONGER STORMS OVER THE
SOUTHWEST THIRD OF THE CWA. HAIL POTENTIAL WILL BE LIMITED DUE TO
THE LIMITED INSTABILITY AND TALL/SKINNY CAPE. AS MENTIONED
ABOVE...GUSTY WINDS WILL BE THE BIGGEST THREAT OVER THE SW
HALF OF THE CWA...AS THEY HAVE THE STEEPER MID LEVEL LAPSE
RATES...COMBINED WITH THE DRY LOW LEVELS TO PRODUCE THE HIGHER
DCAPE VALUES.
THEN...AS THE SHORTWAVE TRACKS SOUTHEAST INTO NORTHWEST WISCONSIN
TONIGHT AND THE REST OF NORTHERN WISCONSIN ON MONDAY
MORNING...WOULD EXPECT SCATTERED SHOWERS TO CONTINUE THROUGH THE
NIGHT OVER THE SOUTHWEST HALF OF THE CWA. THAT IS ALSO WHERE
THE BEST 850-500MB Q-VECTOR CONV IS LOCATED EVEN THOUGH THE DEEPER
MOISTURE IS OVER EASTERN UPPER MICHIGAN. HAVE SLOWLY DIMINISHED THE
THUNDER THREAT OVERNIGHT AND INTO MONDAY MORNING TO BE OVER THE
SOUTHERN PART OF THE CWA...WHERE THE BETTER FORCING IS LOCATED. WILL
HOLD ON TO SOME LIGHT RAIN SHOWERS OVER NORTHERN UPPER MICHIGAN
OVERNIGHT TONIGHT AND INTO TOMORROW MORNING...AS LOW LEVEL
CONVERGENCE INCREASES WITH THE WINDS SHIFTING TO THE
NORTH-NORTHEAST. WITH DECENT MOISTURE BELOW 10KFT AS THAT
CONVERGENCE OCCURS...THINKING THERE WILL BE ENOUGH TO PRODUCE SOME
SHOWERS...ESPECIALLY OVER SOME OF THE HIGHER TERRAIN LOCATIONS OF
NORTH CENTRAL UPPER MICHIGAN WHERE THE WINDS BECOME UPSLOPE FOR A
PERIOD OF TIME.
THE LARGER SCALE FORCING SHOULD DEPART THE SOUTHWEST AND SOUTH
CENTRAL CWA AROUND DAYBREAK AND THEY WILL BE LEFT WITH ANY SHOWERS
DROPPING SOUTH ALONG THE ENHANCED CONVERGENCE. BEHIND THE
TROUGH...LOW CLOUDS SEEN IN CENTRAL ONTARIO/MANITOBA THIS MORNING
WILL MOVE SOUTH ACROSS THE CWA LATE TONIGHT INTO TOMORROW MORNING.
MODELS STRUGGLING WITH HOW LOW THE CLOUDS WILL BE...BUT EITHER WAY
A CLOUDY START TO THE WORK WEEK IS EXPECTED. CANADIAN HIGH PRESSURE
IS EXPECTED TO BUILD OVER THE AREA ON MONDAY AFTERNOON...BRINGING
DRIER AIR AND SUBSIDENCE TO THE AREA IN THE AFTERNOON. THIS WILL
PRODUCE DECREASING CLOUDS FROM NORTH TO SOUTH. HIGHS WILL BE MUCH
COOLER TOMORROW...WITH 60S IN MOST LOCATIONS EXCEPT NEAR LAKE
SUPERIOR WHERE NORTHERLY FLOW OFF THE LAKE WILL KEEP HIGHS IN THE
UPPER 50S.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 452 AM EDT MON JUN 17 2013
TAKING A LOOK AT FCST SOUNDINGS...TUESDAY THROUGH EARLY WEDNESDAY
SHOULD BE PRETTY DRY WITH LITTLE TO NO CLOUDS IN THE SKY. WILL KEEP
THE 0 POPS GOING. OTHER THAN THE TYPICAL LAKE BREEZES...WITH HIGH
PRESSURE DIRECTLY OVERHEAD...WINDS WILL BE LIGHT. WILL LIKELY BE
ABLE TO MIX UP TO 800MB...OR HIGHER...RESULTING IN AFTERNOON RH
VALUES IN THE 20 PERCENT RANGE FOR MOST OF UPPER MI...FIRE CONCERNS
SHOULD REMAIN IN CHECK HOWEVER WITH THE RELATIVELY LIGHT WINDS.
EXPECT THE WARMING TREND TO CONTINUE INTO WEDNESDAY...WITH INCREASED
W-SW FLOW THROUGH 750MB...AS THE SFC HIGH SHIFTS TOWARD THE LOWER
GREAT LAKES. 850MB TEMPS SHOULD RISE FROM A CWA AVERAGE OF 7C
TUESDAY AFTERNOON TO AROUND 12C BY LATE WEDNESDAY AFTERNOON. WITH NW
FLOW ALOFT...EXPECT A FEW PESKY WAVES IN THE MEAN FLOW TO SLIDE
ACROSS THE CWA. THE NEXT SIGNIFICANT ONE WILL LINE UP WITH THE
NEARING OF A WEAK SFC LOW PUSHING OVER ONTARIO WEDNESDAY...AND INTO
QUEBEC LATE WEDNESDAY NIGHT INTO THURSDAY. THE WEAK COLD FRONT
SHOULD BE PRETTY WASHED OUT AS IT NEARS LAKE SUPERIOR WEDNESDAY
NIGHT. A FEW SHOWERS AND POSSIBLY THUNDERSTORMS ACROSS MN AND
WESTERN WI WEDNESDAY MORNING WILL LIKELY BE WINDING DOWN AS THEY
HEAD TOWARD UPPER MI. 200-500 J/KG CAPE VALUES OVER FAR W UPPER MI
BETWEEN 18Z WED AND 00Z THUR SHOULD BE ALL BUT GONE BY 06Z THURSDAY.
MOISTURE LOOKS TO BE VERY LIMITED...WITH ANY GOLF MOISTURE STUCK
ACROSS THE GULF STATES. EXPECT THE WEAK COLD FRONT TO SINK SOUTH OF
THE CWA BY THE END OF THE DAY THURSDAY. THE MAIN RESULT WILL BE
CLOUD COVER AND A WIND SHIFT...AND EVEN THROUGH WE DO HAVE 30-40
PERCENT POPS THEY WILL LIKELY RESULT IN LOW AMOUNTS OF PRECIP WITH
AROUND A TENTH OF AN INCH OR LESS EXPECTED FOR MOST LOCATIONS.
HIGH PRESSURE SET UP ACROSS MUCH OF N AND CENTRAL ONTARIO THURSDAY
MORNING WILL EXTEND A RIDGE ACROSS LAKE SUPERIOR BY LATE THURSDAY
MORNING...AND MUCH OF THE CWA BY 00Z FRIDAY. THE 500MB RIDGE ACROSS
THE PLAINS STATES WILL CONTINUE TO BUILD THURSDAY...IN ADVANCE OF
THE 500MB LOW STUCK SPINNING OVER THE PACIFIC NORTHWEST...AND SFC
LOW ORGANIZING OFF THE ROCKY MOUNTAIN FRONT. WENT AHEAD AND
BROKE UP THE THURSDAY NIGHT PERIOD TO INCLUDE A BIT MORE DRYING
WEATHER THURSDAY EVENING.
THE CLOSEST THE SFC LOW WILL LIKELY GET TO UPPER MI WILL BE MN AND S
WI...ON SATURDAY. STILL...MUCH OF OUR WEATHER FOR FRIDAY THROUGH THE
WEEKEND WILL REVOLVED AROUND THE 500MB FLOW WITH SEVERAL SMALLER
SCALE DISTURBANCES RESULTING IN A FEW TO SCATTERED SHOWERS AND
THUNDERSTORMS THROUGH THE REST OF THE PERIOD. THEY WILL REMAIN
DIFFICULT TO TIME UNTIL WE GET CLOSER TO THE WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 141 AM EDT MON JUN 17 2013
AN UPPER LEVEL DISTURBANCE WILL PRODUCE SHOWERS FOR KIWD AND POSSIBLY
KSAW OVERNIGHT. LIFR CLOUD DECK HAS ALREADY FORMED AT KCMX AND IT
LOOKS LIKE IT/S BEGINNING TO FORM AT KSAW IN UPSLOPE NE FLOW SO WILL
INCLUDE LIFR CLOUDS IN AT BOTH SITES FOR THE OVERNIGHT. BELIEVE IFR
TO LIFR CLOUD DECK WILL ALSO FORM AT KIWD BY 10Z AS WINDS SHIFT
TO ONSHORE NE DIRECTION. LOW CLOUDS WILL GRADUALLY LIFT BY LATE MON
MORNING BRINGING VFR CONDITIONS TO ALL TAF SITES.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 411 PM EDT SUN JUN 16 2013
WINDS ARE EXPECTED TO STAY BELOW 20KTS THROUGH THE PERIOD. A TROUGH
WILL DROP SOUTH ACROSS LAKE SUPERIOR THIS EVENING...LEADING TO WINDS
SHIFTING TO THE NORTH TONIGHT. AS THE TROUGH CONTINUES SOUTHEAST ON
MONDAY...HIGH PRESSURE WILL BUILD OVER THE UPPER GREAT LAKES AND
REMAIN THROUGH WEDNESDAY. A WEAK TROUGH WILL THEN APPROACH THE AREA
FROM THE NORTHWEST FOR THURSDAY. THERE IS A POCKET OF FOG OVER
EASTERN LAKE SUPERIOR /NEAR AND EAST OF GRAND MARAIS MI/ THAT HAS
BEEN DIMINISHING AND MOVING AROUND TODAY. WOULD EXPECT THE DRY AIR
TO CONTINUE TO EAT AWAY AT IT THIS EVENING...BUT THERE IS SOME
CONCERN IT COULD EXPAND WITH RAIN OCCURRING OVER CENTRAL LAKE
SUPERIOR THIS AFTERNOON/EVENING AND LINGER THROUGH THE NIGHT. IF FOG
DOES LINGER TONIGHT...IT WILL CLEAR OUT MON MORNING AS MUCH DRIER AIR
SURGES S INTO THE UPPER LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...KF
AVIATION...07/JV
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
441 AM EDT MON JUN 17 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 411 PM EDT SUN JUN 16 2013
THE MAIN CONCERN FOR THE SHORT TERM FORECAST WILL BE THE ONGOING
SHOWERS AND THUNDERSTORMS AND ADDITIONAL SHOWERS WITH THE TROUGH
DROPPING SOUTH ACROSS THE AREA TONIGHT. INITIAL CONVECTION WAS OVER
EASTERN UPPER MICHIGAN...WHERE THERE WAS INCREASED MOISTURE FROM THE
FOG EARLIER TODAY AND CONVERGENCE FROM WEAK LAKE BREEZES. THESE
INITIAL SHOWERS HAVE SHIFTED TO THE SOUTHEAST AND OUT OF THE
CWA...BUT ARE SEEING SOME SHOWERS IN CENTRAL UPPER MICHIGAN ALONG
THE LAKE SUPERIOR LAKE BREEZE. THESE SHOWERS HAVE BEEN LIMITED THUS
FAR DUE TO THE DRY MID LEVEL AIR EVEN THOUGH THERE IS STRONG
LOW LEVEL LAPSE RATES AND RAP ANALYZED SB CAPE VALUES OF
500-1000 J/KG. BUT WITH THE INVERTED V LOOK TO THE RAP
SOUNDINGS...ML CAPES ARE STRUGGLING TO GET MUCH ABOVE 250-500 J/KG.
THIS DRY AIR CAN ALSO BE SEEN IN THE DEWPOINTS /UPPER 40S/ AWAY
FROM THE INFLUENCE OF THE GREAT LAKES. THERE HAVE EVEN BEEN SOME
SIGNIFICANT JUMPS IN THE DEWPOINTS OVER THE EASTERN CWA...AS THE
LAKE BREEZES HAVE MOVED IN AND OUT OF SOME OF THE SITES. FARTHER
WEST...A PERSISTENT SHOWER/THUNDERSTORM CLUSTER MOVED INTO WESTERN
GOGEBIC COUNTY OVER THE LAST HOUR AND DID PRODUCE SOME GUSTS UP TO
40KTS EVEN THOUGH THE CLUSTER IS DIMINISHING. THIS ISN/T TOO
UNREASONABLE WITH CURRENT DCAPE VALUES OVER MUCH OF UPPER MICHIGAN
AROUND 800-1000 J/KG AND THE INVERTED V SOUNDINGS. WOULD EXPECT
THIS TO BE THE PRIMARY CONCERN FOR ANY SHOWERS/THUNDERSTORMS LATE
THIS AFTERNOON AND EVENING. FINALLY...ADDITIONAL
SHOWERS/THUNDERSTORMS HAVE BEEN ONGOING JUST NORTHEAST OF LAKE
SUPERIOR...DUE TO ONE PIECE OF SHEARED OFF UPPER LEVEL ENERGY
DROPPING SOUTHEAST ALONG THE TROUGH. THESE SHOWERS WILL CONTINUE
QUICKLY SOUTHEAST AS THE STORM MOTION IS AROUND 40KTS.
THE AREA THAT WILL BRING THE BEST CHANCE FOR SHOWERS IS THE
REMNANT SHORTWAVE FROM THE UPPER LOW THAT WAS IN CENTRAL
SASKATCHEWAN YESTERDAY. THIS SHORTWAVE HAS STARTED TO MOVE TOWARDS
THE CANADA/ND/MN BORDER AND HAS SPARKED SHOWERS AND THUNDERSTORMS
ALONG THE SURFACE TROUGH WHERE THERE IS DEEPER MOISTURE. WITH THE
STORM MOTION TO THE SOUTHEAST AROUND 30-35KTS AND THE TROUGH SLOWLY
SAGGING SOUTHEAST...WOULD EXPECT THOSE SHOWERS TO MOVE SOUTHEAST
ACROSS WESTERN/CENTRAL UPPER MICHIGAN LATE THIS AFTERNOON AND INTO
THE EVENING HOURS. NOT ENTIRELY CONFIDENT ON THE EASTERN CWA...AS
IT WILL DEPEND ON THE THUNDERSTORMS CURRENTLY MOVING SOUTHEAST
FROM THUNDER BAY AND HOW FAR SOUTHEAST THEY WILL MAKE IT BEFORE
DIMINISHING. WILL HAVE LOWER POPS THAN OVER THE WEST...BUT STILL
IN THE LOW END CHANCE CATEGORY. AN EARLIER UPDATE COVERED THE
TIMING WELL OVER THE WEST AND HAVE JUST MADE MINOR TWEAKS TO
MATCH THE CURRENT CONDITIONS...WITH MOST AREAS IN THE HIGHER REACHES
OF THE SCATTERED/CHANCE CATEGORY. THINK THERE IS A DECENT SHOT MOST
LOCATIONS WILL SEE RAIN...BUT THE COVERAGE/TIMING WOULD BE BETTER
REFLECTED IN THE SCATTERED WORDING. AS MENTIONED ABOVE...THE DRY
AIR AND LIMITED INSTABILITY WILL BE THE MAIN LIMITING FACTORS TO
THE THUNDERSTORMS AND THEIR SEVERE POTENTIAL. BEST THREAT WILL BE
WEST-SOUTHWEST OF THE CWA WHERE THE 850-700/500MB LAPSE RATES ARE
THE STEEPEST...BUT THERE COULD BE SOME STRONGER STORMS OVER THE
SOUTHWEST THIRD OF THE CWA. HAIL POTENTIAL WILL BE LIMITED DUE TO
THE LIMITED INSTABILITY AND TALL/SKINNY CAPE. AS MENTIONED
ABOVE...GUSTY WINDS WILL BE THE BIGGEST THREAT OVER THE SW
HALF OF THE CWA...AS THEY HAVE THE STEEPER MID LEVEL LAPSE
RATES...COMBINED WITH THE DRY LOW LEVELS TO PRODUCE THE HIGHER
DCAPE VALUES.
THEN...AS THE SHORTWAVE TRACKS SOUTHEAST INTO NORTHWEST WISCONSIN
TONIGHT AND THE REST OF NORTHERN WISCONSIN ON MONDAY
MORNING...WOULD EXPECT SCATTERED SHOWERS TO CONTINUE THROUGH THE
NIGHT OVER THE SOUTHWEST HALF OF THE CWA. THAT IS ALSO WHERE
THE BEST 850-500MB Q-VECTOR CONV IS LOCATED EVEN THOUGH THE DEEPER
MOISTURE IS OVER EASTERN UPPER MICHIGAN. HAVE SLOWLY DIMINISHED THE
THUNDER THREAT OVERNIGHT AND INTO MONDAY MORNING TO BE OVER THE
SOUTHERN PART OF THE CWA...WHERE THE BETTER FORCING IS LOCATED. WILL
HOLD ON TO SOME LIGHT RAIN SHOWERS OVER NORTHERN UPPER MICHIGAN
OVERNIGHT TONIGHT AND INTO TOMORROW MORNING...AS LOW LEVEL
CONVERGENCE INCREASES WITH THE WINDS SHIFTING TO THE
NORTH-NORTHEAST. WITH DECENT MOISTURE BELOW 10KFT AS THAT
CONVERGENCE OCCURS...THINKING THERE WILL BE ENOUGH TO PRODUCE SOME
SHOWERS...ESPECIALLY OVER SOME OF THE HIGHER TERRAIN LOCATIONS OF
NORTH CENTRAL UPPER MICHIGAN WHERE THE WINDS BECOME UPSLOPE FOR A
PERIOD OF TIME.
THE LARGER SCALE FORCING SHOULD DEPART THE SOUTHWEST AND SOUTH
CENTRAL CWA AROUND DAYBREAK AND THEY WILL BE LEFT WITH ANY SHOWERS
DROPPING SOUTH ALONG THE ENHANCED CONVERGENCE. BEHIND THE
TROUGH...LOW CLOUDS SEEN IN CENTRAL ONTARIO/MANITOBA THIS MORNING
WILL MOVE SOUTH ACROSS THE CWA LATE TONIGHT INTO TOMORROW MORNING.
MODELS STRUGGLING WITH HOW LOW THE CLOUDS WILL BE...BUT EITHER WAY
A CLOUDY START TO THE WORK WEEK IS EXPECTED. CANADIAN HIGH PRESSURE
IS EXPECTED TO BUILD OVER THE AREA ON MONDAY AFTERNOON...BRINGING
DRIER AIR AND SUBSIDENCE TO THE AREA IN THE AFTERNOON. THIS WILL
PRODUCE DECREASING CLOUDS FROM NORTH TO SOUTH. HIGHS WILL BE MUCH
COOLER TOMORROW...WITH 60S IN MOST LOCATIONS EXCEPT NEAR LAKE
SUPERIOR WHERE NORTHERLY FLOW OFF THE LAKE WILL KEEP HIGHS IN THE
UPPER 50S.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 411 PM EDT SUN JUN 16 2013
THROUGH THE MIDDLE OF THE WEEK...NW FLOW WILL PREVAIL INTO THE UPPER
GREAT LAKES BTWN A RIDGE DRIFTING FROM THE ROCKIES TO THE PLAINS AND
A BROAD TROF OVER ERN NAMERICA. AS THE RIDGE SHIFTS TO THE
MISSISSIPPI VALLEY/GREAT LAKES LATE WEEK...IT WILL LOOSE AMPLITUDE
AS SHORTWAVE ENERGY EJECTING E FROM A TROF OVER THE NW CONUS BEGINS
TO SUPPRESS THE RIDGE. THE NW FLOW EARLY ON WILL SUPPORT DRY WEATHER
FOR UPPER MI. MOVING INTO THE LATE WEEK PERIOD...PATTERN SHOULD
BECOME ACTIVE WITH DECENT PCPN PROSPECTS AS SHORTWAVES TRACK E
ACROSS THE NRN PLAINS TO THE GREAT LAKES. AS FOR TEMPS...COOLEST
WEATHER WILL OCCUR OVER THE NEXT DAY OR TWO BEHIND SHORTWAVE PASSING
TONIGHT/MON. THEN...DESPITE NW FLOW...TEMPS THRU THE MIDWEEK PERIOD
SHOULD BE CLOSE TO NORMAL OR EVEN A LITTLE ABOVE NORMAL SINCE ERN
TROF WILL NOT HAVE SIGNIFICANT AMPLITUDE INTO THE ERN CONUS...
RESULTING IN COOLER AIR STAYING E AND NE OF THE AREA. TEMPS LATE
WEEK INTO THE WEEKEND WILL BE ABOVE NORMAL WITH WARMER/MORE HUMID
CONDITIONS. COULD BE UNCOMFORTABLY HUMID FOR A DAY OR TWO.
BEGINNING MON NIGHT...A CHILLY NIGHT IS ON THE WAY AS HIGH PRES
BUILDS INTO THE UPPER LAKES. WITH VERY DRY COLUMN (PRECIPITABLE
WATER 30-50PCT OF NORMAL) AND WINDS DIMINISHING TO LIGHT/CALM...WILL
CONTINUE TO FAVOR THE LOW END OF MODEL GUIDANCE FOR MIN TEMPS...
ESPECIALLY OVER THE W WHERE SFC HIGH PRES CENTER WILL BE ARRIVING
DURING THE NIGHT. WITH IDEAL RADIATIONAL COOLING CONDITIONS...THERE
IS A GOOD POTENTIAL FOR SOME FROST IN THE USUAL COLDER AREAS.
SOME OF THE TRADITIONAL COLD SPOTS COULD FALL TO NEAR FREEZING.
RECORD LOW FOR NWS MQT SITE ON THE 18TH IS 38F. NOT OUT OF THE
QUESTION THAT RECORD COULD BE TIED OR BROKEN.
SFC HIGH PRES WILL BE SETTLED OVER THE UPPER LAKES TUE...PROVIDING A
DRY/PLEASANT MID JUNE DAY WITH ABUNDANT SUNSHINE UNDER LINGERING
VERY DRY COLUMN. LAKE BREEZES WILL BE THE RULE...KEEPING LAKESIDE
LOCATIONS COOLER IN THE AFTN. GIVEN AVBL DRY AIR TO MIX DOWN...DWPTS
SHOULD FALL TO THE MID 30S...POSSIBLY LOWER...IN THE INTERIOR...
RESULTING IN MIN RH DOWN AROUND 25PCT. WOULDN`T BE SURPRISED TO SEE
SOME LOCATIONS FALL TO AROUND 20PCT. FORTUNATELY...LIGHT WINDS WILL
KEEP FIRE WX CONCERNS IN CHECK.
MEDIUM RANGE GUIDANCE HAS AND STILL CONTINUES TO HINT THAT A
SHORTWAVE WILL DROP SE...PASSING JUST N OF UPPER MI LATE WED/WED
NIGHT. GIVEN THE FAIRLY CONSISTENT SIGNAL FROM ALL MEDIUM RANGE
GUIDANCE...IT STILL APPEARS THERE MAY BE SOME PCPN AT SOME POINT
LATE WED/WED NIGHT. NOTHING MORE THAN SCHC/LOW CHC POPS ARE
WARRANTED SINCE BETTER FORCING PASSES BY TO THE N AND SINCE COVERAGE
WILL BE LOW IF PCPN DOES OCCUR. IF WAVE IS FASTER AND ARRIVES DURING
PEAK HEATING WED...PCPN CHC WILL BE GREATER...BUT WOULD STILL NOT
EXPECT ANYTHING MORE THAN SCT COVERAGE.
ON THU...THERE IS THE POTENTIAL FOR SUBTLE BOUNDARY ASSOCIATED WITH
THE SHORTWAVE PASSING BY THE AREA WED NIGHT TO HANG UP OVER/NEAR
UPPER MI...AND THAT COULD BE THE FOCUS FOR SOME CONVECTION THU AFTN.
MAINTAINED SCHC/LOW CHC POPS IN FCST.
AS MENTIONED EARLIER...THE LATE WEEK PERIOD INTO THE WEEKEND COULD
BECOME ACTIVE AS SHORTWAVES TRACK ACROSS THE NRN CONUS TO THE GREAT
LAKES...SUPPRESSING THE RIDGE THAT WAS SHIFTING ACROSS THE PLAINS
TOWARD THE AREA. SIGNAL LOOKS STRONG ENOUGH TO WARRANT AT LEAST MID
RANGE CHC POPS FOR SHRA/TSRA FOR PORTIONS OF FRI/SAT. SFC HIGH PRES
MAY BEGIN TO BUILD S TOWARD THE UPPER LAKES SUN IN THE WAKE OF A
SHORTWAVE SWINGING ACROSS HUDSON BAY/QUEBEC...SO PCPN CHANCES MAY
DIMINISH ON SUN. OVERALL...THERE APPEARS TO BE DECENT POTENTIAL THAT
MOST LOCATIONS WILL SEE SOME RAIN AT SOME POINT BTWN FRI AND SUN.
&&
FOR THE EXTENDED...
ISSUED AT 440 AM EDT MON JUN 17 2013
MODELS ARE STILL IN FAIRLY GOOD AGREEMENT IN THE PLACEMENT OF A
MID/UPPER LEVEL RIDGE OVER THE PLAINS THROUGH THE DAY FRIDAY...WITH
THE ASSOCIATED SURFACE HIGH PRESSURE DOMINATING THE UPPER GREAT
LAKES REGION THROUGH SATURDAY. THIS WILL KEEP DRY WEATHER WITH
PREDOMINATE LIGHT N/NERLY WINDS THROUGH THIS TIME PERIOD.
SUNNY/PARTLY CLOUDY SKIES WILL KEEP TEMPERATURES FAIRLY STEADY /AT
OR SLIGHTLY BELOW NORMAL/...WITH COOLEST TEMPERATURES NEAR LAKE
SUPERIOR DUE TO NORTHERLY WINDS OFF THE LAKE.
MODEL CONSENSUS ALSO SHOWS A SHORTWAVE DEVELOPING ON THE BACKSIDE OF
THE RIDGE...HOWEVER DISAGREEMENTS COME IN TO PLAY ON THE PATH THIS
SHORTWAVE WILL TAKE. GFS AND GEM SOLUTIONS HAVE THE SHORTWAVE
DEVELOPING OVER THE PLAINS ON SATURDAY...THEN GETTING PUSHED TO THE
SOUTHEAST UNDER THE INFLUENCE OF THE HIGH PRESSURE RIDGE AND DRY AIR
ALREADY IN PLACE. THIS SOLUTION SEEMS THE MOST REASONABLE. ECMWF
SOLUTION ON THE OTHER HAND CONTINUES TO BE MORE AGGRESSIVE WITH THIS
SYSTEM...MOVING IT NORTHEAST ALONG THE BACKSIDE OF THE RIDGE AND
REACHING THE UPPER GREAT LAKES BY SATURDAY AFTERNOON. WITH THE
GFS/GEM...UPPER MI SHOULD REMAIN DRY. HOWEVER WILL KEEP SLIGHT
CHANCES NEAR THE WI BORDER SATURDAY AFTERNOON...SPREADING FURTHER
INLAND SATURDAY NIGHT AND SUNDAY TO ACCOUNT FOR ECMWF SOLUTION. WITH
THE INCREASE IN CLOUD COVER ASSOCIATED WITH THIS SYSTEM...EXPECT LOW
TEMPERATURES SAT NIGHT TO BE SLIGHTLY WARMER THAN PREVIOUS...BUT
STILL HOVERING ON THE FREEZING LINE...SO SNOW COULD MIX IN WITH RAIN
IN AFFECTED AREAS. PRECIP SHOULD DISSIPATE BY SUNDAY NIGHT AS
SHORTWAVE MOVES TO THE SOUTHEAST AND HIGH PRESSURE BEGINS TO BUILD
IN FROM CANADA THROUGH THE DAY MONDAY.
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 141 AM EDT MON JUN 17 2013
AN UPPER LEVEL DISTURBANCE WILL PRODUCE SHOWERS FOR KIWD AND POSSIBLY
KSAW OVERNIGHT. LIFR CLOUD DECK HAS ALREADY FORMED AT KCMX AND IT
LOOKS LIKE IT/S BEGINNING TO FORM AT KSAW IN UPSLOPE NE FLOW SO WILL
INCLUDE LIFR CLOUDS IN AT BOTH SITES FOR THE OVERNIGHT. BELIEVE IFR
TO LIFR CLOUD DECK WILL ALSO FORM AT KIWD BY 10Z AS WINDS SHIFT
TO ONSHORE NE DIRECTION. LOW CLOUDS WILL GRADUALLY LIFT BY LATE MON
MORNING BRINGING VFR CONDITIONS TO ALL TAF SITES.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 411 PM EDT SUN JUN 16 2013
WINDS ARE EXPECTED TO STAY BELOW 20KTS THROUGH THE PERIOD. A TROUGH
WILL DROP SOUTH ACROSS LAKE SUPERIOR THIS EVENING...LEADING TO WINDS
SHIFTING TO THE NORTH TONIGHT. AS THE TROUGH CONTINUES SOUTHEAST ON
MONDAY...HIGH PRESSURE WILL BUILD OVER THE UPPER GREAT LAKES AND
REMAIN THROUGH WEDNESDAY. A WEAK TROUGH WILL THEN APPROACH THE AREA
FROM THE NORTHWEST FOR THURSDAY. THERE IS A POCKET OF FOG OVER
EASTERN LAKE SUPERIOR /NEAR AND EAST OF GRAND MARAIS MI/ THAT HAS
BEEN DIMINISHING AND MOVING AROUND TODAY. WOULD EXPECT THE DRY AIR
TO CONTINUE TO EAT AWAY AT IT THIS EVENING...BUT THERE IS SOME
CONCERN IT COULD EXPAND WITH RAIN OCCURRING OVER CENTRAL LAKE
SUPERIOR THIS AFTERNOON/EVENING AND LINGER THROUGH THE NIGHT. IF FOG
DOES LINGER TONIGHT...IT WILL CLEAR OUT MON MORNING AS MUCH DRIER AIR
SURGES S INTO THE UPPER LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...ROLFSON
EXTENDED...
AVIATION...07/JV
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
148 AM EDT MON JUN 17 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 411 PM EDT SUN JUN 16 2013
THE MAIN CONCERN FOR THE SHORT TERM FORECAST WILL BE THE ONGOING
SHOWERS AND THUNDERSTORMS AND ADDITIONAL SHOWERS WITH THE TROUGH
DROPPING SOUTH ACROSS THE AREA TONIGHT. INITIAL CONVECTION WAS OVER
EASTERN UPPER MICHIGAN...WHERE THERE WAS INCREASED MOISTURE FROM THE
FOG EARLIER TODAY AND CONVERGENCE FROM WEAK LAKE BREEZES. THESE
INITIAL SHOWERS HAVE SHIFTED TO THE SOUTHEAST AND OUT OF THE
CWA...BUT ARE SEEING SOME SHOWERS IN CENTRAL UPPER MICHIGAN ALONG
THE LAKE SUPERIOR LAKE BREEZE. THESE SHOWERS HAVE BEEN LIMITED THUS
FAR DUE TO THE DRY MID LEVEL AIR EVEN THOUGH THERE IS STRONG
LOW LEVEL LAPSE RATES AND RAP ANALYZED SB CAPE VALUES OF
500-1000 J/KG. BUT WITH THE INVERTED V LOOK TO THE RAP
SOUNDINGS...ML CAPES ARE STRUGGLING TO GET MUCH ABOVE 250-500 J/KG.
THIS DRY AIR CAN ALSO BE SEEN IN THE DEWPOINTS /UPPER 40S/ AWAY
FROM THE INFLUENCE OF THE GREAT LAKES. THERE HAVE EVEN BEEN SOME
SIGNIFICANT JUMPS IN THE DEWPOINTS OVER THE EASTERN CWA...AS THE
LAKE BREEZES HAVE MOVED IN AND OUT OF SOME OF THE SITES. FARTHER
WEST...A PERSISTENT SHOWER/THUNDERSTORM CLUSTER MOVED INTO WESTERN
GOGEBIC COUNTY OVER THE LAST HOUR AND DID PRODUCE SOME GUSTS UP TO
40KTS EVEN THOUGH THE CLUSTER IS DIMINISHING. THIS ISN/T TOO
UNREASONABLE WITH CURRENT DCAPE VALUES OVER MUCH OF UPPER MICHIGAN
AROUND 800-1000 J/KG AND THE INVERTED V SOUNDINGS. WOULD EXPECT
THIS TO BE THE PRIMARY CONCERN FOR ANY SHOWERS/THUNDERSTORMS LATE
THIS AFTERNOON AND EVENING. FINALLY...ADDITIONAL
SHOWERS/THUNDERSTORMS HAVE BEEN ONGOING JUST NORTHEAST OF LAKE
SUPERIOR...DUE TO ONE PIECE OF SHEARED OFF UPPER LEVEL ENERGY
DROPPING SOUTHEAST ALONG THE TROUGH. THESE SHOWERS WILL CONTINUE
QUICKLY SOUTHEAST AS THE STORM MOTION IS AROUND 40KTS.
THE AREA THAT WILL BRING THE BEST CHANCE FOR SHOWERS IS THE
REMNANT SHORTWAVE FROM THE UPPER LOW THAT WAS IN CENTRAL
SASKATCHEWAN YESTERDAY. THIS SHORTWAVE HAS STARTED TO MOVE TOWARDS
THE CANADA/ND/MN BORDER AND HAS SPARKED SHOWERS AND THUNDERSTORMS
ALONG THE SURFACE TROUGH WHERE THERE IS DEEPER MOISTURE. WITH THE
STORM MOTION TO THE SOUTHEAST AROUND 30-35KTS AND THE TROUGH SLOWLY
SAGGING SOUTHEAST...WOULD EXPECT THOSE SHOWERS TO MOVE SOUTHEAST
ACROSS WESTERN/CENTRAL UPPER MICHIGAN LATE THIS AFTERNOON AND INTO
THE EVENING HOURS. NOT ENTIRELY CONFIDENT ON THE EASTERN CWA...AS
IT WILL DEPEND ON THE THUNDERSTORMS CURRENTLY MOVING SOUTHEAST
FROM THUNDER BAY AND HOW FAR SOUTHEAST THEY WILL MAKE IT BEFORE
DIMINISHING. WILL HAVE LOWER POPS THAN OVER THE WEST...BUT STILL
IN THE LOW END CHANCE CATEGORY. AN EARLIER UPDATE COVERED THE
TIMING WELL OVER THE WEST AND HAVE JUST MADE MINOR TWEAKS TO
MATCH THE CURRENT CONDITIONS...WITH MOST AREAS IN THE HIGHER REACHES
OF THE SCATTERED/CHANCE CATEGORY. THINK THERE IS A DECENT SHOT MOST
LOCATIONS WILL SEE RAIN...BUT THE COVERAGE/TIMING WOULD BE BETTER
REFLECTED IN THE SCATTERED WORDING. AS MENTIONED ABOVE...THE DRY
AIR AND LIMITED INSTABILITY WILL BE THE MAIN LIMITING FACTORS TO
THE THUNDERSTORMS AND THEIR SEVERE POTENTIAL. BEST THREAT WILL BE
WEST-SOUTHWEST OF THE CWA WHERE THE 850-700/500MB LAPSE RATES ARE
THE STEEPEST...BUT THERE COULD BE SOME STRONGER STORMS OVER THE
SOUTHWEST THIRD OF THE CWA. HAIL POTENTIAL WILL BE LIMITED DUE TO
THE LIMITED INSTABILITY AND TALL/SKINNY CAPE. AS MENTIONED
ABOVE...GUSTY WINDS WILL BE THE BIGGEST THREAT OVER THE SW
HALF OF THE CWA...AS THEY HAVE THE STEEPER MID LEVEL LAPSE
RATES...COMBINED WITH THE DRY LOW LEVELS TO PRODUCE THE HIGHER
DCAPE VALUES.
THEN...AS THE SHORTWAVE TRACKS SOUTHEAST INTO NORTHWEST WISCONSIN
TONIGHT AND THE REST OF NORTHERN WISCONSIN ON MONDAY
MORNING...WOULD EXPECT SCATTERED SHOWERS TO CONTINUE THROUGH THE
NIGHT OVER THE SOUTHWEST HALF OF THE CWA. THAT IS ALSO WHERE
THE BEST 850-500MB Q-VECTOR CONV IS LOCATED EVEN THOUGH THE DEEPER
MOISTURE IS OVER EASTERN UPPER MICHIGAN. HAVE SLOWLY DIMINISHED THE
THUNDER THREAT OVERNIGHT AND INTO MONDAY MORNING TO BE OVER THE
SOUTHERN PART OF THE CWA...WHERE THE BETTER FORCING IS LOCATED. WILL
HOLD ON TO SOME LIGHT RAIN SHOWERS OVER NORTHERN UPPER MICHIGAN
OVERNIGHT TONIGHT AND INTO TOMORROW MORNING...AS LOW LEVEL
CONVERGENCE INCREASES WITH THE WINDS SHIFTING TO THE
NORTH-NORTHEAST. WITH DECENT MOISTURE BELOW 10KFT AS THAT
CONVERGENCE OCCURS...THINKING THERE WILL BE ENOUGH TO PRODUCE SOME
SHOWERS...ESPECIALLY OVER SOME OF THE HIGHER TERRAIN LOCATIONS OF
NORTH CENTRAL UPPER MICHIGAN WHERE THE WINDS BECOME UPSLOPE FOR A
PERIOD OF TIME.
THE LARGER SCALE FORCING SHOULD DEPART THE SOUTHWEST AND SOUTH
CENTRAL CWA AROUND DAYBREAK AND THEY WILL BE LEFT WITH ANY SHOWERS
DROPPING SOUTH ALONG THE ENHANCED CONVERGENCE. BEHIND THE
TROUGH...LOW CLOUDS SEEN IN CENTRAL ONTARIO/MANITOBA THIS MORNING
WILL MOVE SOUTH ACROSS THE CWA LATE TONIGHT INTO TOMORROW MORNING.
MODELS STRUGGLING WITH HOW LOW THE CLOUDS WILL BE...BUT EITHER WAY
A CLOUDY START TO THE WORK WEEK IS EXPECTED. CANADIAN HIGH PRESSURE
IS EXPECTED TO BUILD OVER THE AREA ON MONDAY AFTERNOON...BRINGING
DRIER AIR AND SUBSIDENCE TO THE AREA IN THE AFTERNOON. THIS WILL
PRODUCE DECREASING CLOUDS FROM NORTH TO SOUTH. HIGHS WILL BE MUCH
COOLER TOMORROW...WITH 60S IN MOST LOCATIONS EXCEPT NEAR LAKE
SUPERIOR WHERE NORTHERLY FLOW OFF THE LAKE WILL KEEP HIGHS IN THE
UPPER 50S.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 411 PM EDT SUN JUN 16 2013
THROUGH THE MIDDLE OF THE WEEK...NW FLOW WILL PREVAIL INTO THE UPPER
GREAT LAKES BTWN A RIDGE DRIFTING FROM THE ROCKIES TO THE PLAINS AND
A BROAD TROF OVER ERN NAMERICA. AS THE RIDGE SHIFTS TO THE
MISSISSIPPI VALLEY/GREAT LAKES LATE WEEK...IT WILL LOOSE AMPLITUDE
AS SHORTWAVE ENERGY EJECTING E FROM A TROF OVER THE NW CONUS BEGINS
TO SUPPRESS THE RIDGE. THE NW FLOW EARLY ON WILL SUPPORT DRY WEATHER
FOR UPPER MI. MOVING INTO THE LATE WEEK PERIOD...PATTERN SHOULD
BECOME ACTIVE WITH DECENT PCPN PROSPECTS AS SHORTWAVES TRACK E
ACROSS THE NRN PLAINS TO THE GREAT LAKES. AS FOR TEMPS...COOLEST
WEATHER WILL OCCUR OVER THE NEXT DAY OR TWO BEHIND SHORTWAVE PASSING
TONIGHT/MON. THEN...DESPITE NW FLOW...TEMPS THRU THE MIDWEEK PERIOD
SHOULD BE CLOSE TO NORMAL OR EVEN A LITTLE ABOVE NORMAL SINCE ERN
TROF WILL NOT HAVE SIGNIFICANT AMPLITUDE INTO THE ERN CONUS...
RESULTING IN COOLER AIR STAYING E AND NE OF THE AREA. TEMPS LATE
WEEK INTO THE WEEKEND WILL BE ABOVE NORMAL WITH WARMER/MORE HUMID
CONDITIONS. COULD BE UNCOMFORTABLY HUMID FOR A DAY OR TWO.
BEGINNING MON NIGHT...A CHILLY NIGHT IS ON THE WAY AS HIGH PRES
BUILDS INTO THE UPPER LAKES. WITH VERY DRY COLUMN (PRECIPITABLE
WATER 30-50PCT OF NORMAL) AND WINDS DIMINISHING TO LIGHT/CALM...WILL
CONTINUE TO FAVOR THE LOW END OF MODEL GUIDANCE FOR MIN TEMPS...
ESPECIALLY OVER THE W WHERE SFC HIGH PRES CENTER WILL BE ARRIVING
DURING THE NIGHT. WITH IDEAL RADIATIONAL COOLING CONDITIONS...THERE
IS A GOOD POTENTIAL FOR SOME FROST IN THE USUAL COLDER AREAS.
SOME OF THE TRADITIONAL COLD SPOTS COULD FALL TO NEAR FREEZING.
RECORD LOW FOR NWS MQT SITE ON THE 18TH IS 38F. NOT OUT OF THE
QUESTION THAT RECORD COULD BE TIED OR BROKEN.
SFC HIGH PRES WILL BE SETTLED OVER THE UPPER LAKES TUE...PROVIDING A
DRY/PLEASANT MID JUNE DAY WITH ABUNDANT SUNSHINE UNDER LINGERING
VERY DRY COLUMN. LAKE BREEZES WILL BE THE RULE...KEEPING LAKESIDE
LOCATIONS COOLER IN THE AFTN. GIVEN AVBL DRY AIR TO MIX DOWN...DWPTS
SHOULD FALL TO THE MID 30S...POSSIBLY LOWER...IN THE INTERIOR...
RESULTING IN MIN RH DOWN AROUND 25PCT. WOULDN`T BE SURPRISED TO SEE
SOME LOCATIONS FALL TO AROUND 20PCT. FORTUNATELY...LIGHT WINDS WILL
KEEP FIRE WX CONCERNS IN CHECK.
MEDIUM RANGE GUIDANCE HAS AND STILL CONTINUES TO HINT THAT A
SHORTWAVE WILL DROP SE...PASSING JUST N OF UPPER MI LATE WED/WED
NIGHT. GIVEN THE FAIRLY CONSISTENT SIGNAL FROM ALL MEDIUM RANGE
GUIDANCE...IT STILL APPEARS THERE MAY BE SOME PCPN AT SOME POINT
LATE WED/WED NIGHT. NOTHING MORE THAN SCHC/LOW CHC POPS ARE
WARRANTED SINCE BETTER FORCING PASSES BY TO THE N AND SINCE COVERAGE
WILL BE LOW IF PCPN DOES OCCUR. IF WAVE IS FASTER AND ARRIVES DURING
PEAK HEATING WED...PCPN CHC WILL BE GREATER...BUT WOULD STILL NOT
EXPECT ANYTHING MORE THAN SCT COVERAGE.
ON THU...THERE IS THE POTENTIAL FOR SUBTLE BOUNDARY ASSOCIATED WITH
THE SHORTWAVE PASSING BY THE AREA WED NIGHT TO HANG UP OVER/NEAR
UPPER MI...AND THAT COULD BE THE FOCUS FOR SOME CONVECTION THU AFTN.
MAINTAINED SCHC/LOW CHC POPS IN FCST.
AS MENTIONED EARLIER...THE LATE WEEK PERIOD INTO THE WEEKEND COULD
BECOME ACTIVE AS SHORTWAVES TRACK ACROSS THE NRN CONUS TO THE GREAT
LAKES...SUPPRESSING THE RIDGE THAT WAS SHIFTING ACROSS THE PLAINS
TOWARD THE AREA. SIGNAL LOOKS STRONG ENOUGH TO WARRANT AT LEAST MID
RANGE CHC POPS FOR SHRA/TSRA FOR PORTIONS OF FRI/SAT. SFC HIGH PRES
MAY BEGIN TO BUILD S TOWARD THE UPPER LAKES SUN IN THE WAKE OF A
SHORTWAVE SWINGING ACROSS HUDSON BAY/QUEBEC...SO PCPN CHANCES MAY
DIMINISH ON SUN. OVERALL...THERE APPEARS TO BE DECENT POTENTIAL THAT
MOST LOCATIONS WILL SEE SOME RAIN AT SOME POINT BTWN FRI AND SUN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 141 AM EDT MON JUN 17 2013
AN UPPER LEVEL DISTURBANCE WILL PRODUCE SHOWERS FOR KIWD AND POSSIBLY
KSAW OVERNIGHT. LIFR CLOUD DECK HAS ALREADY FORMED AT KCMX AND IT
LOOKS LIKE IT/S BEGINNING TO FORM AT KSAW IN UPSLOPE NE FLOW SO WILL
INCLUDE LIFR CLOUDS IN AT BOTH SITES FOR THE OVERNIGHT. BELIEVE IFR
TO LIFR CLOUD DECK WILL ALSO FORM AT KIWD BY 10Z AS WINDS SHIFT
TO ONSHORE NE DIRECTION. LOW CLOUDS WILL GRADUALLY LIFT BY LATE MON
MORNING BRINGING VFR CONDITIONS TO ALL TAF SITES. &&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 411 PM EDT SUN JUN 16 2013
WINDS ARE EXPECTED TO STAY BELOW 20KTS THROUGH THE PERIOD. A TROUGH
WILL DROP SOUTH ACROSS LAKE SUPERIOR THIS EVENING...LEADING TO WINDS
SHIFTING TO THE NORTH TONIGHT. AS THE TROUGH CONTINUES SOUTHEAST ON
MONDAY...HIGH PRESSURE WILL BUILD OVER THE UPPER GREAT LAKES AND
REMAIN THROUGH WEDNESDAY. A WEAK TROUGH WILL THEN APPROACH THE AREA
FROM THE NORTHWEST FOR THURSDAY. THERE IS A POCKET OF FOG OVER
EASTERN LAKE SUPERIOR /NEAR AND EAST OF GRAND MARAIS MI/ THAT HAS
BEEN DIMINISHING AND MOVING AROUND TODAY. WOULD EXPECT THE DRY AIR
TO CONTINUE TO EAT AWAY AT IT THIS EVENING...BUT THERE IS SOME
CONCERN IT COULD EXPAND WITH RAIN OCCURRING OVER CENTRAL LAKE
SUPERIOR THIS AFTERNOON/EVENING AND LINGER THROUGH THE NIGHT. IF FOG
DOES LINGER TONIGHT...IT WILL CLEAR OUT MON MORNING AS MUCH DRIER AIR
SURGES S INTO THE UPPER LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...ROLFSON
AVIATION...07/JV
MARINE...SRF
AREA FORECAST DISCUSSION
NWS BUFFALO NY
103 AM EDT MON JUN 17 2013
.SYNOPSIS...
A WAVE OF LOW PRESSURE ASSOCIATED WITH THE UPPER LEVEL TROUGH WILL
BRING A WEAK COLD FRONT ACROSS THE REGION ON MONDAY...BRINGING
SHOWERS AND A FEW THUNDERSTORMS THROUGH MONDAY NIGHT. A LARGE AREA
OF HIGH PRESSURE WILL THEN MOVE INTO THE GREAT LAKES...REMAINING
NEARLY STATIONARY OVER THE REGION. THIS PATTERN WILL GENERATE SOME
SUN ALONG WITH NEARLY SEASONAL TEMPERATURES.
&&
.NEAR TERM /THROUGH TODAY/...
A CLUSTER OF THUNDERSTORMS WHICH FORMED NORTH OF LAKE ONTARIO LAST
EVENING CONTINUES TO SHIFT SOUTHEAST ACROSS LAKE ONTARIO EARLY THIS
MORNING. SOME GUSTY WINDS AND POSSIBLE SMALL HAIL MAY EXIST WITHIN
THE STRONGER CELLS. MESOANALYSIS SHOWS A WEAK POOL OF ELEVATED
INSTABILITY...LESS THAN 500 J/KG SURFACE/MIXED LAYER CAPE...OVER THE
FORECAST AREA THAT THESE STORMS ARE FEEDING ON. THE HRRR MODEL HAS
CAPTURED THIS CLUSTER WELL AND SHOWS IT WILL CONTINUE SOUTHEAST
WHILE WEAKENING SOME ONCE IT REACHES THE SOUTHEASTERN LAKE ONTARIO
SHORELINE. FORECAST GRIDS HAVE BEEN UPDATED WITH THIS IN MIND.
OUTFLOW BOUNDARIES SURGING SOUTH FROM THIS CLUSTER WILL BE WATCHED
FOR TRIGGERING NEW CELLS FURTHER WEST NORTH OF THE NY THRUWAY. A
SECOND MUCH SMALLER AREA OF THUNDERSTORMS HAS NOW SHIFTED SOUTH OF
CHAUTAUQUA COUNTY INTO NORTHWESTERN PA.
BROAD MID LEVEL TROUGHING ANCHORED ACROSS THE SOUTH CENTRAL CANADA
WILL UNDERGO SOME STRENGTHENING WITH TIME OVER THE NEXT 24 HOURS
WITH A CLOSED LOW EVOLVING OVER HUDSON BAY. THIS WILL PROMPT THE
SOUTHERN EXTENSION OF THE MAIN HEIGHT FALL REGION TO SQUEEZE INTO
THE PREVAILING MID LEVEL WESTERLIES POSITIONED OVER THE GREAT LAKES.
THIS PROCESS WILL ALLOW A COLD FRONTAL BOUNDARY TO SETTLE SOUTHWARD
INTO THE LOWER LAKES REGION DURING THE DAY MONDAY. SOLID WINDOW WILL
EXIST TO CAPITALIZE ON DAYTIME HEATING WITH INCREASING CHANCES FOR
SHOWERS AND THUNDERSTORMS DURING THE AFTERNOON HOURS.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
DURING THE COURSE OF MONDAY NIGHT...THE COLD FRONT WILL CONTINUE TO
SAG SOUTHWARD ACROSS THE AREA...WITH ADDITIONAL SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS ACCOMPANYING THE PASSAGE OF THIS
FEATURE DURING THE EVENING. WILL CONTINUE TO INDICATE THE HIGHEST
PRECIPITATION CHANCES /LIKELIES/ ACROSS THE NORTH COUNTRY WHERE
FORCING AND MOISTURE WILL BE MOST CONCENTRATED...WITH CHANCE POPS
FOR AREAS SOUTH OF LAKE ONTARIO. FOLLOWING THE FROPA...SCATTERED
LEFTOVER SHOWERS WILL SLOWLY DIMINISH FROM NORTH TO SOUTH
OVERNIGHT...WHICH WILL BE REFLECTED IN THE FORECAST WITH POPS
GRADUALLY DIMINISHING THROUGH THE CHANCE RANGE. WITH A FAIR AMOUNT
OF CLOUD COVER LINGERING IN PLACE AND COLD ADVECTION JUST STARTING
TO SET UP BEHIND THE FRONT OVERNIGHT...TEMPS WILL NOT DROP OFF TOO
MUCH...AND WILL GENERALLY BOTTOM OUT IN THE LOWER 50S ACROSS THE
NORTH COUNTRY AND THE MID-UPPER 50S ELSEWHERE...OR RIGHT ABOUT
NORMAL FOR MID JUNE.
ON TUESDAY...THE COLD FRONT WILL CONTINUE TO SAG SOUTH TO THE
VICINITY OF THE MASON-DIXON LINE...THOUGH A CONSENSUS OF THE 12Z
GUIDANCE SUITE NOW SUGGESTS THAT THIS BOUNDARY WILL DEPART A LITTLE
MORE SLOWLY THAN PREVIOUSLY FORECAST. CONSEQUENTLY...HAVE KEPT CLOUD
COVER AND CHANCES FOR A LEFTOVER SHOWER OR TWO IN A LITTLE LONGER
THAN IN PREVIOUS FORECASTS...THOUGH THE BULK OF THE DAY SHOULD STILL
BE DRY WITH MOST AREAS SEEING A RETURN TO AT LEAST PARTIAL SUNSHINE
BY AFTERNOON AS SPRAWLING CANADIAN HIGH PRESSURE OVER THE UPPER
LAKES BEGINS TO TAKE HOLD. UNDER CONTINUED COOL AIR ADVECTION...850
MB TEMPS WILL DROP OFF TO +6C TO +10C...WHICH SHOULD RESULT IN HIGHS
FALLING BACK TO BELOW NORMAL LEVELS IN THE UPPER 60S TO LOWER 70S.
TUESDAY NIGHT...THE AFOREMENTIONED RIDGE WILL CONTINUE TO BUILD
SOUTHEAST TOWARD OUR REGION ALONG WITH PROGRESSIVELY COOLER AND
DRIER AIR...BEFORE SETTLING DIRECTLY ACROSS NEW YORK STATE FOR
WEDNESDAY AND WEDNESDAY NIGHT. THIS WILL PROVIDE OUR AREA WITH
TRANQUIL WEATHER FOR THE LATTER HALF OF THE PERIOD...ALONG WITH
CONTINUED BELOW NORMAL TEMPERATURES. EXPECT NIGHTTIME LOWS TUESDAY
NIGHT AND WEDNESDAY NIGHT TO DIP INTO THE MID TO UPPER 40S IN MOST
LOCATIONS...WITH ONLY THE LAKE PLAINS REMAINING IN THE LOWER 50S.
MEANWHILE...HIGHS ON WEDNESDAY SHOULD AGAIN RANGE WITHIN A FEW
DEGREES OF 70.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
DURING THE FIRST COUPLE DAYS OF THE EXTENDED PERIOD...LINGERING
BROAD/RELATIVELY FLAT TROUGHING ALOFT WILL GIVE WAY TO A MORE ZONAL
FLOW ACROSS OUR REGION...WHILE SURFACE HIGH PRESSURE SLOWLY DRIFTS
FROM THE SPINE OF THE APPALACHIANS TO A POSITION OFF THE EAST COAST
BY FRIDAY. THIS WILL RESULT IN CONTINUED MAINLY DRY WEATHER THROUGH
THE END OF THE WORK WEEK...THOUGH A COUPLE WEAK FEATURES DROPPING
THROUGH THE BACKSIDE OF THE DEPARTING TROUGH COULD TOUCH OFF AN
ISOLATED SHOWER OR TWO ACROSS THE SAINT LAWRENCE VALLEY/NORTH
COUNTRY BOTH THURSDAY AND FRIDAY.
AS WE GET INTO NEXT WEEKEND...INCREASING RETURN FLOW ON THE BACKSIDE
OF THE RIDGE SHOULD PUMP SOMEWHAT MORE HUMID AIR BACK INTO OUR
REGION...AND THIS COUPLED WITH DAYTIME HEATING AND THE APPROACH OF
THE NEXT FRONTAL SYSTEM SHOULD EVENTUALLY RESULT IN A MORE GENERAL
CHANCE OF SOME SCATTERED CONVECTION BY SATURDAY NIGHT AND SUNDAY.
ACCORDINGLY...HAVE INDICATED POPS CLIMBING BACK TO LOW CHANCE LEVELS
DURING THIS TIME FRAME.
WITH RESPECT TO TEMPERATURES...THE ABOVE EVOLUTION IN THE PATTERN
WILL ALSO RESULT IN READINGS MODERATING BACK TO NEAR NORMAL LEVELS
BY THURSDAY...THEN TO AT LEAST A BIT ABOVE NORMAL FOR THE REMAINDER
OF THE PERIOD. MORE SPECIFICALLY...DAYTIME HIGHS IN THE 70S ON
THURSDAY SHOULD WARM BACK TO AT LEAST THE LOWER 80S FOR THE
WEEKEND...WITH SOME READINGS IN THE MID 80S POSSIBLE DEPENDING ON
BOTH THE EVENTUAL TEMPERATURES ALOFT AND THE AREAL COVERAGE OF ANY
CONVECTION/ASSOCIATED CLOUD COVER. AS MENTIONED ABOVE...HUMIDITY
LEVELS SHOULD ALSO BE ON THE RISE...WITH COMFORTABLE DEWPOINTS OF
AROUND 50 ON THURSDAY CLIMBING BACK TO MODERATELY HUMID LEVELS IN
THE LOWER 60S BY SUNDAY.
&&
.AVIATION /05Z MONDAY THROUGH FRIDAY/...
VFR FOUND AT THE TAF SITES EARLY THIS MORNING. SOME CONVECTION
SHIFTING SOUTHEAST ACROSS LAKE ONTARIO IS NOT EXPECTED TO LARGELY
IMPACT TERMINALS. MAY SEE A VCTS OR -TSRA AT KROC IF NEW CELLS
DEVELOP ON STORM OUTFLOW. OTHERWISE...PARTIAL CLEARING AND
DIMINISHING WINDS MAY ALLOW FOR ENOUGH RADIATIONAL COOLING OVER WET
GROUNDS TO DEVELOP SOME LOWER CLOUDS AND FOG OVERNIGHT. KJHW MAY SEE
CONDITIONS DOWN TO MVFR. ON MONDAY A CHANCE OF SHOWERS AND
THUNDERSTORMS IS POSSIBLE WITH AFTERNOON HEATING AND BROAD UPPER
LEVEL TROUGH BUILDING SOUTH OVER NEW YORK.
OUTLOOK...
MONDAY AND TUESDAY...MAINLY VFR WITH A CHANCE OF SHOWERS
AND THUNDERSTORMS.
WEDNESDAY THROUGH FRIDAY...VFR.
&&
.MARINE...
CLUSTER OF THUNDERSTORMS IS FOUND OF LAKE ONTARIO EARLY THIS
MORNING. THIS WILL SHIFT SOUTHEAST OVER THE EASTERN HALF OF THE LAKE
EARLY THIS MORNING AND SHIFT OVER CENTRAL NEW YORK FROM THE LAKE.
UNSETTLED CONDITIONS WHICH CONTINUE FOR THE CHANCE OF SHOWERS AND
THUNDERSTORMS WILL CONTINUE MONDAY INTO TUESDAY WITH BROAD UPPER
LEVEL TROUGH OVER NEW YORK THEN BY WEDNESDAY HIGH PRESSURE WILL
BUILD BACK ACROSS THE LOWER LAKES WITH TRANQUIL CONDITIONS.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SMITH/TMA
NEAR TERM...SMITH/TMA/WCH
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...SMITH
MARINE...SMITH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
308 AM EDT MON JUN 17 2013
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST TODAY AND ACROSS OUR
REGION LATE TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 940 PM SUNDAY...
RELATIVELY BENIGN CONVECTION HAS BEEN MOVING WEST TO EAST ACROSS
KY/WV/VA THIS EVENING...WITHIN A ZONE OF PREFRONTAL CONVERGENCE AND
DEEP MOISTURE. FURTHER SOUTH OVER THE LOWER TENNESSEE
VALLEY...WHERE DAYTIME INSTABILITY STILL LINGERS...A MORE WELL
DEFINED CLUSTER OF STORMS IS CURRENTLY MOVING ACROSS NORTHERN GA AND
AND INTO FAR WESTERN NC. THESE TWO AREAS WILL GRADUALLY POSE A
THREAT TO THE NORTHERN AND WESTERN PORTIONS OF CENTRAL NC THROUGH
MONDAY. TONIGHT...FORCING WILL BE WEAK AS THE MOIST/CONVERGENCE
AXIS..WHERE PW VALUES AT 1.5-2"...SLOWLY SHIFTS SOUTHEASTWARD TOWARD
THE AREA. THE AFOREMENTIONED CLUSTER OF STORMS APPROACHING WESTERN
NC SHOULD WEAKEN AS IT ENCOUNTERS MORE HOSTILE AIR EAST OF THE
MOUNTAINS...BUT THE LINGERING OUTFLOW COULD ALSO SERVE AS A CATALYST
FOR SHOWERS IF IT DRIFTS ALL THE WAY INTO THE SOUTHERN/WESTERN
PIEDMONT. BASED ON CURRENT RADAR TRENDS AND LATEST HRRR DATA...HAVE
PUSHED CHANCE POPS BACK UNTIL AFTER 08Z. OTHERWISE...TEMPS WILL
REMAIN RATHER MILD..FALLING INTO THE UPPER 60S AS CLOUDS STEADILY
INCREASE. -BLS
MONDAY...THE MID-LEVEL SHORTWAVE IS FORECAST TO MOVE THROUGH CENTRAL
NORTH CAROLINA...LEAVING SOME SUBSIDENCE IN ITS WAKE LATE IN THE
DAY...MAINLY TOWARD THE TRIAD. THE NAM IS WEAKER WITH ITS
MIXED-LAYER CAPE...500-1000J/KG COMPARED TO THE 1000-1500J/KG OF THE
GFS. BOTH MODELS SHOW ONLY LIMITED DOWNDRAFT CAPE...MAINLY 200J/KG
OR LESS...UNDER WEAK 0-3KM SHEAR IN THE RANGE OF 15KT. 1000-500MB
LAPSE RATES ARE WEAK AS WELL...TO ABOUT 6C/KM BASED ON THE HIGHER
GFS. AS THE DISTURBANCE PASSES THROUGH WITH A WEAK SURFACE TROUGH IN
PLACE...WILL ESSENTIALLY CARRY HIGH CHANCE POPS FOR THE DAY...
CONFINING THOSE POPS MAINLY TO THE AFTERNOON IN THE FAR SOUTHEAST.
ANTICIPATING MORE CLOUDS...HAVE LOWERED MAXES FOR MONDAY TO THE
LOWER TO MID 80S.
MONDAY NIGHT...BOTH THE NAM AND THE GFS FORECAST SOME SUBSIDENCE
BEHIND THE MID-LEVEL SHORTWAVE...PARTICULARLY FROM THE TRIANGLE
NORTHWEST AND NORTH OVERNIGHT. THIS MAY RESULT IN CHANCES FOR
PRECIPITATION BECOMING LIMITED IN THOSE AREAS. FARTHER
SOUTH...HIGHER MOISTURE AND INSTABILITY PERSISTS OVERNIGHT...WITH
ANOTHER MID-LEVEL SHORTWAVE SKIRTING THE AREA TO THE SOUTH. IF THIS
VERIFIES...CHANCES FOR SHOWERS AND ISOLATED THUNDERSTORMS COULD
LINGER INTO THE OVERNIGHT HOURS...ESPECIALLY ACROSS THE SANDHILLS
AND SOUTHERN COASTAL PLAIN. FOR THIS FORECAST...WILL SHOW A
DIMINISHING TREND TO PRECIPITATION CHANCES...ONLY SLIGHT CHANCE IN
THE TRIAD OVERNIGHT WITH CHANCES MAINLY ALONG AND SOUTH OF U.S. 64.
ONCE AGAIN...OVERNIGHT LOWS SHOULD BE WARM...WITHIN A DEGREE OR
THREE OF 70.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 240 AM MONDAY...
A SERIES OF DISTURBANCES ALOFT...WHICH HAVE TRENDED WEAKER IN NWP
GUIDANCE DURING THE PAST FEW DAYS AND WHOSE TIMING IS UNCERTAIN
GIVEN THE PROBABILITY OF BEING MODULATED BY UPSTREAM
CONVECTION...WILL MIGRATE THROUGH THE BASE OF A BROAD TROUGH ALOFT
EAST OF THE ROCKIES...AND ACROSS THE CENTRAL APPALACHIANS/NC THROUGH
WED. MEANWHILE AT THE SURFACE...A PRE-FRONTAL TROUGH OVER THE MIDDLE
ATLANTIC REGION THIS MORNING WILL STRENGTHEN THROUGH TUE...THEN BE
OVERTAKEN BY A COLD FRONT THAT WILL SETTLE SLOWLY SOUTHWARD FROM THE
MASON DIXON LINE TUE EVENING TO THE NC/SC LINE BY WED EVENING.
PRECIPITABLE WATER VALUES WILL CONSEQUENTLY REMAIN ABOVE
AVERAGE...BETWEEN 1.5 AND 1.8 INCHES... UNTIL FRONTAL PASSAGE. THE
DEEP MOISTURE AND ASSOCIATED UNINHIBITED CONDITIONAL INSTABILITY...
WHICH IS FORECAST TO MAXIMIZE IN THE 1000-1500 J/KG EACH
AFTERNOON...WILL SUPPORT NUMEROUS TO WIDESPREAD THUNDERSTORMS...WITH
COVERAGE DIMINISHING WITH NOCTURNAL COOLING TUE NIGHT...AND THEN
FROM NORTH TO SOUTH WITH THE FRONTAL PASSAGE ON WED. GIVEN THE
EXPECTATION OF WEAKER DISTURBANCES THAN PREVIOUSLY INDICATED...NOTED
ABOVE...MID LEVEL FLOW AND ASSOCIATED BULK SHEAR VALUES ARE NOW
FORECAST TO PEAK ONLY IN THE 20-25 KT RANGE...HIGHEST WED. AS
SUCH...ALREADY MINIMAL SEVERE POTENTIAL WILL BE FURTHER MUTED UNLESS
POCKETS OF STRONGER INSOLATION AND MODERATE INSTABILITY ARE
REALIZED...IN WHICH CASE A FEW STRONG-MARGINALLY SEVERE WET
MICROBURSTS WOULD BE PROBABLE. A MORE LIKELY SCENARIO REMAINS A
THREAT OF DOWNPOURS AND LOCALIZED FLOODING IN TRAINING
CONVECTION...OWING TO WSW MEAN FLOW ALIGNED PARALLEL TO THE MYRIAD
OF UNDERLYING SURFACE BOUNDARIES (TROUGH/EFFECTIVE FRONT-OUTFLOW
/ACTUAL FRONT...AND TO BACKBUILDING INDICATED BY SMALL FORECAST
CORFIDI VECTORS. ANY SUCH FLOODING WILL NOT BE WIDESPREAD...AND
INSTEAD CONFINED MOST LIKELY TO URBAN AREAS SINCE THE ANDREA-SOAKED
SOIL HAS DRIED IN THE PAST WEEK TO 10 DAYS...AND RESULTANT FLASH
FLOOD GUIDANCE VALUES HAVE INCREASED...INTO THE 2.5 TO 3 INCH RANGE
FOR ONE HOUR FOR EXAMPLE.
PROVIDED THERE ARE AT LEAST A FEW BREAKS IN OTHERWISE MOSTLY CLOUDY
SKIES AND CONVECTION...TEMPERATURES SHOULD CLIMB INTO THE LOWER TO
MIDDLE 80S...WARMEST SANDHILLS TUE. OTHERWISE...UPPER 70S WOULD BE
PROBABLE (IE. IN AREAS THAT EXPERIENCE MORE FREQUENT SHOWERS AND
STORMS). LOWS TUE NIGHT MOSTLY IN THE UPPER 60S...TO AROUND 70
DEGREES SOUTH...COOLING A CATEGORY TO TWO IN COOLER POST-FRONTAL NE
FLOW WED NIGHT.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 305 AM SUNDAY...
THU THROUGH FRI: BELOW AVERAGE TEMPERATURES - GENERALLY IN THE LOWER
TO MIDDLE 80S - IN WEAK POST-FRONTAL HIGH PRESSURE AND ASSOCIATED NE
TO EAST LOW LEVEL FLOW AND STABILITY...WILL THEN PREVAIL THROUGH THE
END OF THE WEEK. WILL ACCORDINGLY MAINTAIN THE FLAVOR OF PREVIOUS
GENERALLY DRY FORECASTS FOR THU-FRI...EXCEPT FOR THE SLIGHTEST OF
CHANCES ALONG THE FAR SOUTHERN AND WESTERN TIER...WHERE BOUNDARY
LAYER MOISTURE WOULD SUPPORT A LATE DAY SHOWER OR STORM. EVEN THAT
SLIGHT CHANCE MAY BE OVERDONE GIVEN AN APPARENT LACK OF TRIGGER
AMIDST DIVERGENT ANTICYCLONIC FLOW WITHIN THE AFOREMENTIONED SURFACE
RIDGE AXIS.
THIS WEEKEND: A SHALLOW UPPER LOW WILL HAVE DRIFTED INTO THE
SOUTHEAST STATES BY THE START OF THE WEEKEND...BUT INSTEAD OF
LIFTING TOWARD THE EAST COAST...GUIDANCE SUGGESTS THIS FEATURE WILL
MOVE WESTWARD AROUND THE SOUTHERN PERIPHERY OF A DEVELOPING
MID-UPPER RIDGE FROM THE SOUTHERN PLAINS TO THE MIDDLE ATLANTIC
REGION. AS SUCH...TEMPERATURES...AND HUMIDITY LEVELS WILL GRADUALLY
INCREASE IN INCREASINGLY SE TO SOUTHERLY RETURN FLOW. THE INCREASING
WARMTH AND HUMIDITY WILL ALSO SUPPORT A SLIGHT UPTICK IN PROBABILITY
OF PRECIPITATION...THOUGH STILL BELOW CLIMATOLOGICAL VALUES IN THE
20TH PERCENTILE GIVEN THE AFOREMENTIONED EXPANSION OF RIDGING
ALOFT...AND LACK OF LOW LEVEL FOCI OTHER THAN PERHAPS THE SEA
BREEZE.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 140 AM MONDAY...
WARM...MOIST...BUT WEAKLY FORCED ENVIRONMENT WILL REMAIN OVER
CENTRAL NC THIS TAF PERIOD. CONDITIONS WILL REMAIN VFR THROUGH THE
PERIOD OUTSIDE OF CONVECTION.
EXPECT A GRADUAL INCREASE THIS MORNING IN MID LEVEL CLOUDINESS
ACROSS THE NORTHERN TIER OF THE AREA. WEAK FORCING FROM OVERNIGHT
CONVECTION IN WESTERN TN AND NORTHERN GA WILL BE MIGRATING INTO THE
WESTERN PIEDMONT THIS MORNING...WITH SCATTERED SHOWERS AT INT/GSO
AFTER SUNRISE...PERHAPS MID MORNING FURTHER EAST...RDU AND RWI.
DECENT INSTABILITY WILL SUPPORT MORE WIDESPREAD SHOWERS AND WIDELY
SCATTERED THUNDER THIS AFTERNOON...TSRA COVERAGE AND CONFIDENCE IN
TIMING/PLACEMENT PRECLUDE TAF INCLUSION AT THIS TIME. EXPECT A LULL
OVERNIGHT ALTHOUGH SCATTERED SHOWERS ARE EXPECTED. WINDS WILL BE
SOUTH TO SOUTHWEST AT LESS THAN 10KT.
ADDITIONAL DISTURBANCES WILL BE CROSSING THE AREA ALONG WITH A WEAK
COLD FRONT TUESDAY INTO WEDNESDAY...WITH PERIODS OF SHOWERS AND
STORMS PRODUCING SUB-VFR CONDITIONS. VFR CONDITIONS ARE
GENERALLY EXPECTED FROM THURSDAY ONWARD... OUTSIDE OF POSSIBLY SOME
EARLY MORNING STRATUS AND OR FOG DURING THE PRE-DAWN HOURS OF EACH
MORNING.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MLM
NEAR TERM...DJF/BLS
SHORT TERM...MWS
LONG TERM...MWS
AVIATION...MLM
AREA FORECAST DISCUSSION
NWS RALEIGH NC
140 AM EDT MON JUN 17 2013
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST TODAY AND ACROSS OUR
REGION LATE TUESDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF 940 PM SUNDAY...
RELATIVELY BENIGN CONVECTION HAS BEEN MOVING WEST TO EAST ACROSS
KY/WV/VA THIS EVENING...WITHIN A ZONE OF PREFRONTAL CONVERGENCE AND
DEEP MOISTURE. FURTHER SOUTH OVER THE LOWER TENNESSEE
VALLEY...WHERE DAYTIME INSTABILITY STILL LINGERS...A MORE WELL
DEFINED CLUSTER OF STORMS IS CURRENTLY MOVING ACROSS NORTHERN GA AND
AND INTO FAR WESTERN NC. THESE TWO AREAS WILL GRADUALLY POSE A
THREAT TO THE NORTHERN AND WESTERN PORTIONS OF CENTRAL NC THROUGH
MONDAY. TONIGHT...FORCING WILL BE WEAK AS THE MOIST/CONVERGENCE
AXIS..WHERE PW VALUES AT 1.5-2"...SLOWLY SHIFTS SOUTHEASTWARD TOWARD
THE AREA. THE AFOREMENTIONED CLUSTER OF STORMS APPROACHING WESTERN
NC SHOULD WEAKEN AS IT ENCOUNTERS MORE HOSTILE AIR EAST OF THE
MOUNTAINS...BUT THE LINGERING OUTFLOW COULD ALSO SERVE AS A CATALYST
FOR SHOWERS IF IT DRIFTS ALL THE WAY INTO THE SOUTHERN/WESTERN
PIEDMONT. BASED ON CURRENT RADAR TRENDS AND LATEST HRRR DATA...HAVE
PUSHED CHANCE POPS BACK UNTIL AFTER 08Z. OTHERWISE...TEMPS WILL
REMAIN RATHER MILD..FALLING INTO THE UPPER 60S AS CLOUDS STEADILY
INCREASE. -BLS
MONDAY...THE MID-LEVEL SHORTWAVE IS FORECAST TO MOVE THROUGH CENTRAL
NORTH CAROLINA...LEAVING SOME SUBSIDENCE IN ITS WAKE LATE IN THE
DAY...MAINLY TOWARD THE TRIAD. THE NAM IS WEAKER WITH ITS
MIXED-LAYER CAPE...500-1000J/KG COMPARED TO THE 1000-1500J/KG OF THE
GFS. BOTH MODELS SHOW ONLY LIMITED DOWNDRAFT CAPE...MAINLY 200J/KG
OR LESS...UNDER WEAK 0-3KM SHEAR IN THE RANGE OF 15KT. 1000-500MB
LAPSE RATES ARE WEAK AS WELL...TO ABOUT 6C/KM BASED ON THE HIGHER
GFS. AS THE DISTURBANCE PASSES THROUGH WITH A WEAK SURFACE TROUGH IN
PLACE...WILL ESSENTIALLY CARRY HIGH CHANCE POPS FOR THE DAY...
CONFINING THOSE POPS MAINLY TO THE AFTERNOON IN THE FAR SOUTHEAST.
ANTICIPATING MORE CLOUDS...HAVE LOWERED MAXES FOR MONDAY TO THE
LOWER TO MID 80S.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
AS OF 250 PM SUNDAY...
MONDAY NIGHT...BOTH THE NAM AND THE GFS FORECAST SOME SUBSIDENCE
BEHIND THE MID-LEVEL SHORTWAVE...PARTICULARLY FROM THE TRIANGLE
NORTHWEST AND NORTH OVERNIGHT. THIS MAY RESULT IN CHANCES FOR
PRECIPITATION BECOMING LIMITED IN THOSE AREAS. FARTHER SOUTH...
HIGHER MOISTURE AND INSTABILITY PERSISTS OVERNIGHT...WITH ANOTHER
MID-LEVEL SHORTWAVE SKIRTING THE AREA TO THE SOUTH. IF THIS
VERIFIES...CHANCES FOR SHOWERS AND ISOLATED THUNDERSTORMS COULD
LINGER INTO THE OVERNIGHT HOURS...ESPECIALLY ACROSS THE SANDHILLS
AND SOUTHERN COASTAL PLAIN. FOR THIS FORECAST...WILL SHOW A
DIMINISHING TREND TO PRECIPITATION CHANCES...ONLY SLIGHT CHANCE IN
THE TRIAD OVERNIGHT WITH CHANCES MAINLY ALONG AND SOUTH OF U.S. 64.
ONCE AGAIN...OVERNIGHT LOWS SHOULD BE WARM...WITHIN A DEGREE OR
THREE OF 70. -DJF
TUESDAY...A DAMPENING MID LEVEL S/W CROSSING CENTRAL NC DURING PRIME
HEATING SHOULD INTERACT WITH THE MOIST AND SLIGHTLY UNSTABLE AIR
MASS IN PLACE TO TRIGGER NUMEROUS-WIDESPREAD SHOWERS AND A FEW
T-STORMS...MAINLY TUESDAY AFTERNOON. LOW LEVEL CONVERGENCE WILL BE
MAXIMIZED ALONG A SWD DRIFTING SFC BOUNDARY WILL LIFT ALOFT A RESULT
OF THE WEAKENING S/W AND 300MB JET CROSSING SOUTHERN NEW ENGLAND
PLACING CENTRAL NC IN THE FAVORABLE RIGHT ENTRANCE REGION. DYNAMICS
NOT OVERLY IMPRESSIVE THOUGH 30KTS OF BULK SHEAR OCCUR IN THE
AFTERNOON ACROSS THE NORTH AND MLCAPE (GFS) REACHES 1000-1400 J/KG
IN THE AFTERNOON. AS ELUDED TO IN PREVIOUS FORECAST...POTENTIAL FOR
SHOWERS/STORMS TO PASS REPEATEDLY OVER THE SAME LOCATION AS MEAN
FLOW PARALLEL TO THE SWD DRIFTING SFC BOUNDARY. THIS MAY LEAD TO
LOCALIZED FLOODING ISSUES...MAINLY IN URBAN AREAS. ANY UPDRAFTS ABLE
TO SUSTAIN MORE THAN 20 MINUTES MAY PRODUCE A WET MICROBURST BUT A
MARGINAL WIND PROFILE AND DEEP MOISTURE (LACK OF DRY AIR
ENTRAINMENT) SUGGEST ANY DAMAGING WINDS WILL BE QUITE ISOLATED.
TUESDAY NIGHT INTO WEDNESDAY...MID LEVEL TROUGH AND ASSOCIATED SFC
BOUNDARY DRIFT SE AND EXIT THE REGION TUESDAY EVENING. THIS SUGGEST
A GRADUAL DIMINISHING IN CONVECTIVE COVERAGE FROM THE NORTH TUESDAY.
ON WEDNESDAY...S/W IN THE ACTIVE NORTHERN STREAM WILL CROSS THE MID
ATLANTIC WEDNESDAY. THIS FEATURE WILL SEND ANOTHER SFC FRONT SWD
ACROSS CENTRAL NC ON WEDNESDAY. WEAK CONVERGENCE ALONG THIS BOUNDARY
COUPLED WITH MODEST UPPER AIR SUPPORT MAY TRIGGER/SUSTAIN
ISOLATED-SCATTERED SHOWERS AND THUNDERSTORMS ON WEDNESDAY. COVERAGE
APPEARS TO BE BETTER SOUTH VERSUS NORTH AS AIR MASS ACROSS THE NORTH
WILL BE DRIER AND MORE STABLE.
HIGH TEMPERATURES TUESDAY DEPENDENT ON CONVECTIVE COVERAGE. IF
WIDESPREAD CONVECTION OCCURS SOONER THAN ANTICIPATED...MAX TEMPS MAY
BE 3-4 DEGREES TOO WARM. A SFC N-NE FLOW WILL SLOWLY ADVECT COOLER
AIR INTO CENTRAL NC WEDNESDAY. LOW LEVEL THICKNESSES SUPPORT MAX
TEMPS NEAR 80-LOWER 80S. -WSS
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 250 PM SUNDAY...
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...SURFACE RIDGE WILL
STRENGTHEN OVER CENTRAL NC. RESULTANT LOW LEVEL NE FLOW WILL
MAINTAIN A RELATIVELY COOL AND STABLE AIR MASS OVER THE BULK OF
CENTRAL NC. THE EXCEPTION WILL BE THE FAR SOUTH AND WEST AS ENOUGH
LIFT/MOISTURE MAY EXIST AROUND THE PERIPHERY OF THE RIDGE TO PERMIT
ISOLATED CONVECTION TO OCCUR. AFTERNOON TEMPS THURSDAY WILL AGAIN
AVERAGE A FEW DEGREES BELOW NORMAL WITH MOST SPOTS IN THE LOWER 80S.
MIN TEMPS BOTH NIGHTS IN THE LOW-MID 60S.
FRI-SUN: MEDIUM RANGE GUIDANCE DIFFER IN THE UPPER AIR PATTERN OVER
THE CAROLINAS AT THE END OF THE WEEK. GFS DEPICTION OF A SERIES OF
S/W CROSSING THE OH VALLEY INTO THE NORTHERN MID ATLANTIC EXTENDING
SWD INTO CENTRAL NC FRI-SAT WOULD SUGGEST A THREAT OF SCATTERED
CONVECTION OVER OUR REGION. MEANWHILE...ECMWF DEPICTS AN ELONGATED
UPPER LEVEL LOW/SHEAR AXIS OFF THE SE U.S. COAST THAT MOVES LITTLE
FRI-SAT. THIS FEATURE ALONG WITH THE MAIN STORM TRACK ACROSS THE
LOWER GREAT LAKES INTO THE NORTHERN MID ATLANTIC PERMITS A NARROW
RIDGE OF HIGH PRESSURE TO EXTEND ACROSS THE CAROLINAS FROM AN
ANTI-CYCLONE POSITIONED OVER THE SOUTHERN PLAINS/LOWER MS VALLEY.
THIS SCENARIO WOULD KEEP CENTRAL NC DRY FRI AND SAT. DIFFICULT TO
SAY AT THIS TIME WHICH SCENARIO MOST LIKELY TO VERIFY AS EACH
SCENARIO HAS AN EQUAL CHANCE TO VERIFY. BY SUNDAY....MODEL CONSENSUS
KEYS ON UPPER RIDGE EXPANDING EWD INTO THE CAROLINAS FROM THE
TN-LOWER OH VALLEY. ANY SHEAR AXES ASSOCIATED WITH CONVECTION
OCCURRING ALONG THE STORM TRACK FROM THE GREAT LAKES INTO THE
NORTHERN MID ATLANTIC WOULD BRUSH OUR FAR NE COUNTIES.
AIR MASS WILL GRADUALLY MODIFY THIS PERIOD WITH AFTERNOON TEMPS
RETURNING TO NEAR OR SLIGHTLY ABOVE NORMAL LEVELS BY SUNDAY.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 140 AM MONDAY...
WARM...MOIST...BUT WEAKLY FORCED ENVIRONMENT WILL REMAIN OVER
CENTRAL NC THIS TAF PERIOD. CONDITIONS WILL REMAIN VFR THROUGH THE
PERIOD OUTSIDE OF CONVECTION.
EXPECT A GRADUAL INCREASE THIS MORNING IN MID LEVEL CLOUDINESS
ACROSS THE NORTHERN TIER OF THE AREA. WEAK FORCING FROM OVERNIGHT
CONVECTION IN WESTERN TN AND NORTHERN GA WILL BE MIGRATING INTO THE
WESTERN PIEDMONT THIS MORNING...WITH SCATTERED SHOWERS AT INT/GSO
AFTER SUNRISE...PERHAPS MID MORNING FURTHER EAST...RDU AND RWI.
DECENT INSTABILITY WILL SUPPORT MORE WIDESPREAD SHOWERS AND WIDELY
SCATTERED THUNDER THIS AFTERNOON...TSRA COVERAGE AND CONFIDENCE IN
TIMING/PLACEMENT PRECLUDE TAF INCLUSION AT THIS TIME. EXPECT A LULL
OVERNIGHT ALTHOUGH SCATTERED SHOWERS ARE EXPECTED. WINDS WILL BE
SOUTH TO SOUTHWEST AT LESS THAN 10KT.
ADDITIONAL DISTURBANCES WILL BE CROSSING THE AREA ALONG WITH A WEAK
COLD FRONT TUESDAY INTO WEDNESDAY...WITH PERIODS OF SHOWERS AND
STORMS PRODUCING SUB-VFR CONDITIONS. VFR CONDITIONS ARE
GENERALLY EXPECTED FROM THURSDAY ONWARD... OUTSIDE OF POSSIBLY SOME
EARLY MORNING STRATUS AND OR FOG DURING THE PRE-DAWN HOURS OF EACH
MORNING.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MLM
NEAR TERM...DJF/BLS
SHORT TERM...DJF/WSS
LONG TERM...WSS
AVIATION...MLM
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1218 AM CDT MON JUN 17 2013
.UPDATE...
UPDATED FOR 06Z AVIATION DISCUSSION.
&&
.PREV DISCUSSION... /ISSUED 910 PM CDT SUN JUN 16 2013/
DISCUSSION...WATER VAPOR SATELLITE/UPPER AIR PROFILERS/WSR-88D
VAD WIND PROFILES INDICATE SEVERAL 500 MB MID LEVEL SHORTWAVES
EMBEDDED WITHIN NEARLY ZONAL FLOW ALOFT ACROSS THE
CENTRAL/SOUTHERN PLAINS AND MIDDLE/LOWER MISSISSIPPI VALLEYS THIS
EVENING. SCATTERED SHOWERS AND THUNDERSTORMS ACROSS THE MID SOUTH
DISSIPATED A FEW HOURS AGO WITH THE MOST OF THE CONVECTIVE ACTIVITY
THIS EVENING OCCURRING ACROSS PORTIONS OF OKLAHOMA...MISSOURI...ARKANSAS...AND
TEXAS. TEMPERATURES AS OF 8 PM CDT RANGE FROM THE LOWER TO MIDDLE
80S WEST OF THE MISSISSIPPI RIVER...AND 70S TO LOWER 80S EAST.
SHOWER AND THUNDERSTORM POTENTIAL FOR THE REMAINDER OF THE NIGHT
REMAINS THE PREDOMINANT FORECAST CHALLENGE.
00Z KLZK UPPER AIR SOUNDING STILL REMAINS QUITE UNSTABLE WITH
SURFACE BASED CAPE VALUES AROUND 3200 J/KG...LI/S AROUND -8...AND
VERY LITTLE CONVECTIVE INHIBITION. INSTABILITY AT KJAN REMAINS
SIMILAR WITH MUCH MORE LOW LEVEL MOISTURE PRESENT THAN LZK.
MEANWHILE...INSTABILITY IS LOWER AT OHX THIS EVENING. 18Z MODELS
AND THE 00Z NAM ARE NOT HANDLING THE CURRENT CONVECTIVE ACTIVITY
PARTICULARLY WELL. THE LATEST RAPID REFRESH /HRRR/ INDICATES THE
BEST POTENTIAL FOR SHOWER/THUNDERSTORM ACTIVITY WILL REMAIN MAINLY
ALONG AND WEST OF THE MISSISSIPPI RIVER OVERNIGHT. AN ISOLATED
STRONG TO PERHAPS SEVERE THUNDERSTORM MAY BE POSSIBLE FOR THE NEXT
FEW HOURS MAINLY WEST OF THE MISSISSIPPI RIVER. OTHERWISE...OVERALL
POTENTIAL REMAINS LOW AT THIS TIME.
BASED ON THE LATEST TRENDS WILL LOWER POPS SLIGHTLY ACROSS
EASTERN SECTIONS OF THE FORECAST AREA AND KEEP ONGOING CHANCE POPS
ALONG AND WEST OF THE MISSISSIPPI RIVER. WILL ALSO ADJUST
TEMPERATURES...CLOUD COVER...AND ALL OTHER ELEMENTS AS NEEDED TO
ACCOUNT FOR SHORT TERM TRENDS. OTHERWISE...FORECAST OVERALL IS IN
GOOD SHAPE.
UPDATED GRIDS WILL BE AVAILABLE SHORTLY.
CJC
&&
.PREV DISCUSSION... /ISSUED 620 PM CDT SUN JUN 16 2013/
UPDATE...AVIATION DISCUSSION.
PREV DISCUSSION... /ISSUED 318 PM CDT SUN JUN 16 2013/
DISCUSSION...
WET PATTERN SETTING OVER THE MIDSOUTH OVER THE NEXT COUPLE OF
DAYS AS A COLD FRONT AND SEVERAL SHORTWAVES MOVE INTO THE REGION.
TONIGHT...VERY LOW CONFIDENCE ON WHAT WILL HAPPEN AS MODELS DID
NOT INITIALIZE VERY WELL. ABUNDANCE OF CLOUD COVER OVER THE REGION
HAS KEPT THE ATMOSPHERE MORE STABLE THAN WHAT THE MODELS WERE
INDICATING. THUS THE NAM AND RAP MODELS SHOWED NUMEROUS SHOWERS
AND THUNDERSTORMS DEVELOPING THIS AFTERNOON INTO THE EVENING HOURS
DUE TO THE COMBINATION OF PEAK HEATING AND THE EXPECTED UNSTABLE
ATMOSPHERE. THIS IS NOT THE CASE AT LEAST SO FAR. HOWEVER...WITHIN
THE LAST 45 MINUTES A THUNDERSTORM HAS DEVELOPED OVER PANOLA
COUNTY. THE NAM AND RAP SHOWED WHATEVER ACTIVITY DEVELOPED DYING
OUT AFTER SUNSET. MEANWHILE...OTHER MODELS LIKE THE HRRR SHOWED
DEVELOPMENT ALONG AND AHEAD OF AN OUTFLOW BOUNDARY WHICH IS DRAPED
ACROSS SOUTHERN MISSOURI. BEGINNING TO SEE DEVELOPMENT OCCUR ALONG
THE BOUNDARY BUT NOTHING AHEAD OF IT YET OTHER THAN A FEW SHOWERS.
THE HRRR BRINGS THE ACTIVITY INTO NORTHERN PORTIONS OF THE
MIDSOUTH THIS EVENING AND THEN DISSIPATES IT BY MIDNIGHT. IN
ADDITION...THE GFS AND ECMWF SHOWED LITTLE ACTIVITY OCCURRING THIS
EVENING. IN FACT...THE ECMWF SHOWED LITTLE ACTIVITY THE ENTIRE
NIGHT. HOWEVER...THE GFS AND THE NAM BOTH SHOW REDEVELOPMENT OF
SHOWERS AFTER MIDNIGHT...POSSIBLY DUE TO A WEAK LOW LEVEL JET.
WITH SUCH A WIDE RANGE OF SCENARIOS...HAVE KEPT 40 POPS ACROSS
FROM THE TENNESSEE/MISSISSIPPI LINE NORTHWARD MAINLY DUE TO THE
CONVECTION YOU SEE BEGINNING TO DEVELOP ALONG THE OLD OUTFLOW
BOUNDARY. THINK THIS CONVECTION WILL PUSH DOWN INTO NORTHEAST
ARKANSAS...THE MISSOURI BOOTHEEL...AND NORTHWEST TENNESSEE. MAY
ALSO SEE A FEW MORE POP UP DIURNAL THUNDERSTORMS ACROSS NORTH MISSISSIPPI. DON/T
KNOW IF ANY STORM WILL BE SEVERE BUT WILL KEEP THE STRONG TO
SEVERE WORDING IN THE HWO FOR NOW. LOWS WILL BE IN THE LOWER TO
MID 70S.
MONDAY...A STRONGER SHORTWAVE WILL MOVE INTO THE REGION AS A COLD
FRONT SLIDES SOUTH INTO THE CWA. THE COMBINATION OF THE TWO SHOULD
PRODUCE NUMEROUS SHOWERS AND THUNDERSTORMS ACROSS THE CWA. CLOUD
COVER MAY AFFECT INSTABILITY LIKE IT DID TODAY BUT CAN/T RULE OUT
A FEW STORMS BECOMING STRONG TO SEVERE. ISOLATED HEAVY RAINFALL
UNDERNEATH SLOW MOVING STORMS MAY BE A BIGGEST ISSUE WITH ANY
THUNDERSTORMS THAT OCCUR TOMORROW. THE ACTIVITY WILL CONTINUE INTO
MONDAY NIGHT AND TUESDAY AS THE COLD FRONT SLIDES SOUTHWARD. HIGHS
ON MONDAY AND TUESDAY WILL BE IN THE 80S DUE TO THE CLOUD COVER
AND AMOUNT OF CONVECTION AROUND.
TUESDAY NIGHT INTO WEDNESDAY....THE GFS SLIDES THE FRONT SOUTH OF THE
CWA WHILE THE ECMWF CONTINUES TO HOLD THE FRONT UP OVER NORTH
MISSISSIPPI. BOTH THE GFS/ECMWF ARE CONSISTENT WITH THEIR
SOLUTIONS AND ITS REALLY ANYBODY/S GUESS WHICH IS CORRECT. FOR NOW
WILL CONTINUE WITH CURRENT FORECAST WHICH LEANS TOWARD THE GFS.
THURSDAY AND FRIDAY...UPPER RIDGE BEGINS TO START MOVING BACK INTO
THE AREA FROM THE WEST. SOME DIURNAL CONVECTION COULD OCCUR ON
THURSDAY. OTHERWISE...WARMER TEMPERATURES WILL RETURN WITH HIGHS
IN THE UPPER 80S TO LOWER 90S.
NEXT WEEKEND...HOT AND DRY CONDITIONS ARE EXPECTED AS THE UPPER
RIDGE WILL BE CENTERED OVER THE MIDSOUTH. HIGHS WILL BE IN THE
LOWER TO MID 90S WITH LOWS IN THE 70S.
KRM
&&
.AVIATION...
06Z TAF CYCLE
VFR CONDITIONS WILL PREVAIL THROUGH THIS TAF PERIOD. ONLY ONE STORM
COMPLEX IS OF CONCERN ON THE RADAR...IT MAY IMPACT MEM BETWEEN 09
AND 11Z...BUT CONFIDENCE IS LOW THAT IT WILL -1 STAY TOGETHER...AND
-2 MAINTAIN ITS EASTWARD TRACK. IT IT DOES AN HOUR OR TWO OF MVFR
TO IFR VIS CAN BE EXPECTED ALONG WITH TEMPORARY GUSTY WINDS...MOST
LIKELY FROM THE WEST. REMOVED MENTION OF TS AT ALL OTHER SITES FOR
THE REMAINDER OF THE NIGHT. WINDS WILL BE LIGHT AND VARIABLE DUE TO
MULTIPLE OUTFLOW BOUNDARIES ACROSS THE MIDSOUTH...BUT GENERALLY FROM
THE SOUTH. TOMORROW...THUNDERSTORM COVERAGE WILL INCREASE AGAIN BY
MIDDAY. INCLUDED VCTS AT ALL SITES. INDIVIDUAL STORMS WILL REDUCE
VIS AND MAY RESULT IN STRONG GUSTY WINDS...BUT PREVAILING CONDITIONS
WILL REMAIN VFR. COVERAGE AND INTENSITY OF STORMS SHOULD DIMINISH
AFTER SUNSET.
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 71 86 71 88 / 80 40 10 10
MKL 69 85 64 87 / 80 30 10 10
JBR 69 87 67 87 / 40 10 10 10
TUP 72 84 68 88 / 70 60 10 10
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1140 PM CDT SUN JUN 16 2013
.UPDATE...
06Z TAF DISCUSSION.
&&
.AVIATION...
RADAR INDICATES ONLY A COUPLE ISOLATED SHOWERS REMAIN OVER
EASTERN ZONES NEAR CSV. ALTHOUGH SOME REDEVELOPMENT OF
-SHRA/-TSRA IS POSSIBLE OVERNIGHT...ACTIVITY IS EXPECTED TO
REMAIN SOUTH OF AIRPORTS AND WILL REMOVE PRECIP MENTION FOR
TONIGHT. WIDESPREAD CIRRUS AND MID LEVEL CLOUD COVER PUSHING
ACROSS THE MID STATE WILL PREVENT ANY SIGNIFICANT FOG
FORMATION...BUT SOME MVFR/IFR VIS RESTRICTIONS ARE EXPECTED AT
CKV/CSV OVERNIGHT. SCT CUMULUS TO REDEVELOP ONCE AGAIN ON MONDAY
WITH VCTS BY AFTERNOON AT ALL AIRPORTS. LIGHT SOUTH TO SOUTHWEST
WINDS ARE ANTICIPATED THROUGHOUT THE TAF PERIOD.
SHAMBURGER
&&
.PREV DISCUSSION... /ISSUED 1116 PM CDT SUN JUN 16 2013/
UPDATE...
CONDITIONS CONTINUE TO QUIET DOWN ACROSS THE MID STATE. OVERALL
TREND SHOULD REMAIN THAT WAY AS NVA INDICATED THROUGH THE
OVERNIGHT. ORGANIZED DISTURBANCE UPSTREAM ACROSS WESTERN AR WILL
ATTEMPT TO MOVE EAST BUT IS EXPECTED TO WEAKEN. HOWEVER...ADDITIONAL
MID/HIGH LEVEL CLOUD COVER SHOULD MOVE ACROSS THE AREA LATER
TONIGHT. HRRR STILL SHOWS SOME REDEVELOPMENT ACROSS SOUTHERN
MIDDLE TN TOWARD 12Z. WILL THEREFORE NOT REMOVE POPS ENTIRELY.
FOR THE GRID UPDATE...WILL LOWER POPS AREA WIDE AND INTRODUCE
SOME PARTIAL CLEARING OVER WESTERN ZONES FOR THE NEXT FEW HOURS.
UPDATE OUT SHORTLY.
PREV DISCUSSION... /ISSUED 921 PM CDT SUN JUN 16 2013/
UPDATE...
RADAR COVERAGE HAS DECREASED MARKEDLY ACROSS NORTHERN AND WESTERN
AREAS OF THE MID STATE. MODELS LEAN TOWARD A DECREASE IN MOISTURE
LEVELS ACROSS NORTHERN AREAS. FURTHERMORE...LATEST MODEL SOLUTIONS
SHOWING NVA TOWARD 12Z ACROSS THE NORTH. BUT...LATEST HRRR SOLUTION
TENDS TO REGENERATE CONVECTION ACROSS CENTRAL AND SOUTHERN AREAS
TOWARD 12Z AS SOME UPPER DIVERGENCE REENTERS THE PICTURE TOWARD
12Z. FOR THE UPDATE...WILL CUT POPS TO 30 PERCENT ACROSS THE
NORTH...BUT WILL KEEP THE 40%-50% FOR MUCH OF THE REMAINDER OF
THE MID STATE. UPDATE OUT SHORTLY.
PREV DISCUSSION... /ISSUED 721 PM CDT SUN JUN 16 2013/
UPDATE...
00Z TAF DISCUSSION.
AVIATION...
RADAR INDICATES SCATTERED -TSRA CONTINUE OVER SOUTHERN MIDDLE
TENNESSEE WITH A FEW -SHRA OVER NORTHERN AREAS. WILL CONTINUE
MENTION OF VCTS FOR THE EVENING HOURS FOR ALL AIRPORTS...BUT LACK
OF -TSRA OVER NORTHERN ZONES NO LONGER WARRANT TEMPO GROUPS AND MAY
PROMPT REMOVAL OF VCTS FROM TAFS AS WELL. CONVECTION IS EXPECTED
TO DISSIPATE ACROSS MOST OF THE AREA OVERNIGHT. WIDESPREAD CIRRUS
AND MID LEVEL CLOUD COVER WILL LIKELY PREVENT ANY SIGNIFICANT FOG
FORMATION BUT SOME MVFR VIS RESTRICTIONS ARE POSSIBLE AT CKV/CSV
AROUND SUNRISE. SCT CUMULUS TO DEVELOP ONCE AGAIN MONDAY MORNING
WITH CONVECTION REDEVELOPING DURING THE DAY...WITH MORE VCTS BY
AFTERNOON IF NOT SOONER.
SHAMBURGER
PREV DISCUSSION... /ISSUED 630 PM CDT SUN JUN 16 2013/
CURRENTLY...SCATTERED CONVECTION SOUTH...MINIMAL ACTIVITY NORTH
BUT BETTER COVERAGE NORTHWARD INTO KY. SEMI ACTIVE PATTERN WITHIN
THE WESTERLIES ALOFT AS MINI DISTURBANCES ARE MOVING EASTWARD
WITHIN THE FLOW. LATEST LAPS DATA SHOWING APPRECIABLE SURFACE BASE
CAPES WITH MAXIMUMS LOCATED ACROSS LEWIS COUNTY...AND ALSO OUR FAR
NW AND THE NORTHERN PLATEAU. THUS...THROUGH THIS EVENING STRONG
STORMS WILL BE AN ONGOING POSSIBILITY. NOT SEEING MUCH OVERNIGHT
DIVERGENCE SO NOT LOOKING FOR WIDESPREAD RAINFALL TO DEVELOP
ALTHOUGH MRH LEVELS DO INCREASE SLIGHTLY THROUGH 12Z ACROSS OUR
SOUTHERN COUNTIES.
PREV DISCUSSION... /ISSUED 317 PM CDT SUN JUN 16 2013/
DISCUSSION...
GENERAL TREND FOR THE WEEK AHEAD WILL FEATURE A BUILDING H5 RIDGE
TO OUR WEST WITH OCCASIONAL WEAK SHORT WAVES IN THE NORTHWEST FLOW
ALOFT. BEST CHANCE OF RAIN WILL BE MONDAY INTO EARLY TUESDAY.
AFTER A WEAK COLD FRONTAL PASSAGE ON TUESDAY...EXPECT MAX TEMPS TO
INCREASE TO 85 TO 90 AREA WIDE MID/LATE WEEK AS UPPER LEVEL RIDGE
EDGES CLOSER TO MIDDLE TN.
THIS AFTERNOON/S TEMPS WERE NEAR SATURDAY/S BUT DEW POINTS WERE UP
5 TO 10 DEGREES DUE TO SOUTH FLOW ACROSS THE REGION BEHIND DEPARTED
SFC HIGH PRESSURE. INSTABILITY IS GREATER TODAY BUT STORMS HAVE
BEEN SLOW TO FIRE PARTLY DUE TO EXTENSIVE MID/HIGH CLOUDS
STREAMING IN FROM THE WEST. STILL THINK SOME STORMS WILL DEVELOP
OVER MIDDLE TN NEXT COUPLE HOURS...AND ADDITIONAL STORMS SHOULD
MOVE IN FROM THE WEST WITH THE APPROACHING WEAK SHORT WAVE.
ABOVE AVERAGE CHANCE OF STORMS MONDAY/TUESDAY AS ANOTHER WEAK
SHORT WAVE MOVES INTO THE REGION. BEST CHANCE SHOULD BE LATE
MONDAY INTO EARLY TUESDAY AS WAVE MOVES ACROSS THE AREA AND A WEAK
COLD FRONT MOVES IN FROM THE NORTH. NOT A STRONG PUSH BEHIND THIS
FRONT BUT EXPECT/HOPE IT TO MOVE JUST SOUTH OF MIDDLE TN TUESDAY
NIGHT.
NOT MUCH PRECIP EXPECTED WED/THURS AS MOISTURE SHOULD DECREASE
BEHIND THE FRONT. HOWEVER...LOW LEVEL MOISTURE WILL INCREASE AGAIN
BY FRIDAY AS SFC HIGH SLIDES TO THE EAST. POTENTIAL FOR STORMS
FRIDAY THROUGH NEXT WEEKEND SHOULD BE LIMITED BY INCREASINGLY
STRONG HIGH PRESSURE ALOFT.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1116 PM CDT SUN JUN 16 2013
.UPDATE...
CONDITIONS CONTINUE TO QUIET DOWN ACROSS THE MID STATE. OVERALL
TREND SHOULD REMAIN THAT WAY AS NVA INDICATED THROUGH THE
OVERNIGHT. ORGANIZED DISTURBANCE UPSTREAM ACROSS WESTERN AR WILL
ATTEMPT TO MOVE EAST BUT IS EXPECTED TO WEAKEN. HOWEVER...ADDITIONAL
MID/HIGH LEVEL CLOUD COVER SHOULD MOVE ACROSS THE AREA LATER
TONIGHT. HRRR STILL SHOWS SOME REDEVELOPMENT ACROSS SOUTHERN
MIDDLE TN TOWARD 12Z. WILL THEREFORE NOT REMOVE POPS ENTIRELY.
FOR THE GRID UPDATE...WILL LOWER POPS AREA WIDE AND INTRODUCE
SOME PARTIAL CLEARING OVER WESTERN ZONES FOR THE NEXT FEW HOURS.
UPDATE OUT SHORTLY.
&&
.PREV DISCUSSION... /ISSUED 921 PM CDT SUN JUN 16 2013/
UPDATE...
RADAR COVERAGE HAS DECREASED MARKEDLY ACROSS NORTHERN AND WESTERN
AREAS OF THE MID STATE. MODELS LEAN TOWARD A DECREASE IN MOISTURE
LEVELS ACROSS NORTHERN AREAS. FURTHERMORE...LATEST MODEL SOLUTIONS
SHOWING NVA TOWARD 12Z ACROSS THE NORTH. BUT...LATEST HRRR SOLUTION
TENDS TO REGENERATE CONVECTION ACROSS CENTRAL AND SOUTHERN AREAS
TOWARD 12Z AS SOME UPPER DIVERGENCE REENTERS THE PICTURE TOWARD
12Z. FOR THE UPDATE...WILL CUT POPS TO 30 PERCENT ACROSS THE
NORTH...BUT WILL KEEP THE 40%-50% FOR MUCH OF THE REMAINDER OF
THE MID STATE. UPDATE OUT SHORTLY.
PREV DISCUSSION... /ISSUED 721 PM CDT SUN JUN 16 2013/
UPDATE...
00Z TAF DISCUSSION.
AVIATION...
RADAR INDICATES SCATTERED -TSRA CONTINUE OVER SOUTHERN MIDDLE
TENNESSEE WITH A FEW -SHRA OVER NORTHERN AREAS. WILL CONTINUE
MENTION OF VCTS FOR THE EVENING HOURS FOR ALL AIRPORTS...BUT LACK
OF -TSRA OVER NORTHERN ZONES NO LONGER WARRANT TEMPO GROUPS AND MAY
PROMPT REMOVAL OF VCTS FROM TAFS AS WELL. CONVECTION IS EXPECTED
TO DISSIPATE ACROSS MOST OF THE AREA OVERNIGHT. WIDESPREAD CIRRUS
AND MID LEVEL CLOUD COVER WILL LIKELY PREVENT ANY SIGNIFICANT FOG
FORMATION BUT SOME MVFR VIS RESTRICTIONS ARE POSSIBLE AT CKV/CSV
AROUND SUNRISE. SCT CUMULUS TO DEVELOP ONCE AGAIN MONDAY MORNING
WITH CONVECTION REDEVELOPING DURING THE DAY...WITH MORE VCTS BY
AFTERNOON IF NOT SOONER.
SHAMBURGER
PREV DISCUSSION... /ISSUED 630 PM CDT SUN JUN 16 2013/
MESOSCALE UPDATE...
CURRENTLY...SCATTERED CONVECTION SOUTH...MINIMAL ACTIVITY NORTH
BUT BETTER COVERAGE NORTHWARD INTO KY. SEMI ACTIVE PATTERN WITHIN
THE WESTERLIES ALOFT AS MINI DISTURBANCES ARE MOVING EASTWARD
WITHIN THE FLOW. LATEST LAPS DATA SHOWING APPRECIABLE SURFACE BASE
CAPES WITH MAXIMUMS LOCATED ACROSS LEWIS COUNTY...AND ALSO OUR
FAR NW AND THE NORTHERN PLATEAU. THUS...THROUGH THIS EVENING
STRONG STORMS WILL BE AN ONGOING POSSIBILITY. NOT SEEING MUCH
OVERNIGHT DIVERGENCE SO NOT LOOKING FOR WIDESPREAD RAINFALL TO
DEVELOP ALTHOUGH MRH LEVELS DO INCREASE SLIGHTLY THROUGH 12Z
ACROSS OUR SOUTHERN COUNTIES.
PREV DISCUSSION... /ISSUED 317 PM CDT SUN JUN 16 2013/
DISCUSSION...
GENERAL TREND FOR THE WEEK AHEAD WILL FEATURE A BUILDING H5 RIDGE
TO OUR WEST WITH OCCASIONAL WEAK SHORT WAVES IN THE NORTHWEST FLOW
ALOFT. BEST CHANCE OF RAIN WILL BE MONDAY INTO EARLY TUESDAY.
AFTER A WEAK COLD FRONTAL PASSAGE ON TUESDAY...EXPECT MAX TEMPS TO
INCREASE TO 85 TO 90 AREA WIDE MID/LATE WEEK AS UPPER LEVEL RIDGE
EDGES CLOSER TO MIDDLE TN.
THIS AFTERNOON/S TEMPS WERE NEAR SATURDAY/S BUT DEW POINTS WERE UP
5 TO 10 DEGREES DUE TO SOUTH FLOW ACROSS THE REGION BEHIND DEPARTED
SFC HIGH PRESSURE. INSTABILITY IS GREATER TODAY BUT STORMS HAVE
BEEN SLOW TO FIRE PARTLY DUE TO EXTENSIVE MID/HIGH CLOUDS
STREAMING IN FROM THE WEST. STILL THINK SOME STORMS WILL DEVELOP
OVER MIDDLE TN NEXT COUPLE HOURS...AND ADDITIONAL STORMS SHOULD
MOVE IN FROM THE WEST WITH THE APPROACHING WEAK SHORT WAVE.
ABOVE AVERAGE CHANCE OF STORMS MONDAY/TUESDAY AS ANOTHER WEAK
SHORT WAVE MOVES INTO THE REGION. BEST CHANCE SHOULD BE LATE
MONDAY INTO EARLY TUESDAY AS WAVE MOVES ACROSS THE AREA AND A WEAK
COLD FRONT MOVES IN FROM THE NORTH. NOT A STRONG PUSH BEHIND THIS
FRONT BUT EXPECT/HOPE IT TO MOVE JUST SOUTH OF MIDDLE TN TUESDAY
NIGHT.
NOT MUCH PRECIP EXPECTED WED/THURS AS MOISTURE SHOULD DECREASE
BEHIND THE FRONT. HOWEVER...LOW LEVEL MOISTURE WILL INCREASE AGAIN
BY FRIDAY AS SFC HIGH SLIDES TO THE EAST. POTENTIAL FOR STORMS
FRIDAY THROUGH NEXT WEEKEND SHOULD BE LIMITED BY INCREASINGLY
STRONG HIGH PRESSURE ALOFT.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
21
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
353 AM CDT MON JUN 17 2013
.DISCUSSION...
A LARGE MCS WILL CONTINUE MOVING SOUTHEAST TOWARD NORTH TEXAS
EARLY THIS MORNING AND SHOULD REACH THE NORTHWEST ZONES SHORTLY
BEFORE 6 AM AS PER THE HRRR AND 4KM WRF SOLUTIONS AS WELL AS LINEAR
EXTRAPOLATION. THE COMPLEX SHOULD WEAKEN AS IT MOVES FARTHER AWAY
FROM ITS UPPER SUPPORT AND ALSO ONCE A 30 KNOT LOW LEVEL JET
DECREASES LATER THIS MORNING. THIS SOLUTION IS ALSO SUPPORTED BY
THE HRRR AND 4KM WRF. WE STILL EXPECT EXTENSIVE CLOUD COVER AND
SCATTERED TO NUMEROUS STORMS...THROUGH THE MORNING WITH THE
EXPECTED TIME OF ARRIVAL OF STORMS AT THE METROPLEX BETWEEN 13 AND
15Z. SOME IMPRESSIVE WIND GUSTS BETWEEN 50 AND 55 KNOTS ARE
OCCURRING WITH THE COMPLEX. IT IS VERY POSSIBLE THAT SOME SIMILAR
WIND GUSTS COULD OCCUR ACROSS THE NORTHWEST CWA BY 6 AM. EXPECT
STORMS TO BECOME LESS ORGANIZED BY MIDDAY AND AFFECT MAINLY THE
EAST/NORTHEAST ZONES.
MODELS ARE CONSISTENT ON DEVELOPING MORE STORMS ACROSS WEST TEXAS ALONG
A FAST MOVING SHORT WAVE AND COLD FRONT LATE THIS AFTERNOON. AM A
BIT CONCERNED THAT EXTENSIVE OVERNIGHT/MORNING CONVECTION MAY
HINDER STORM DEVELOPMENT THIS AFTERNOON. HOWEVER...THE ATMOSPHERE
MAY HAVE JUST ENOUGH TIME TO RECOVER BEFORE SURFACE HEATING IS
LOST. STORMS SHOULD ORGANIZE ALONG THE COLD FRONT AND MOVE
SOUTHEAST INTO NORTH TEXAS TONIGHT/TUESDAY MORNING. AGAIN...WILL
KEEP THE HIGHEST POPS ACROSS THE NORTHERN ZONES. THE COLD FRONT IS
PROGGED TO STALL ACROSS THE NORTHERN HALF OF THE REGION TUESDAY
NIGHT AND LIFT NORTH OF THE RED RIVER BY WEDNESDAY EVENING.
AFTER WEDNESDAY...UPPER LEVEL HIGH PRESSURE WILL BUILD FROM
TEXAS...NORTHWARD THROUGH THE CENTRAL PLAINS. THIS PATTERN WILL
RESULT IN HOT TEMPERATURES AND LITTLE RAIN CHANCES WEDNESDAY NIGHT
THROUGH EARLY NEXT WEEK. EXPECT AFTERNOON HIGHS THROUGH EARLY NEXT
WEEK MAINLY IN THE LOWER AND MIDDLE 90S...EXPERT FOR SOME UPPER
90S IN THE WEST. OVERNIGHT LOWS WILL BE IN THE 70S THROUGH EARLY
NEXT WEEK.
79
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 97 77 92 75 95 / 20 30 30 20 20
WACO, TX 95 75 93 74 94 / 10 20 20 20 10
PARIS, TX 93 73 87 72 88 / 50 30 40 40 40
DENTON, TX 98 75 92 73 94 / 40 30 40 30 20
MCKINNEY, TX 94 73 90 73 92 / 30 30 40 30 20
DALLAS, TX 96 77 92 76 93 / 20 30 30 20 20
TERRELL, TX 95 75 91 73 92 / 20 20 30 20 20
CORSICANA, TX 95 74 91 74 92 / 10 20 20 20 10
TEMPLE, TX 95 72 92 73 92 / 5 20 20 10 10
MINERAL WELLS, TX 96 72 92 71 95 / 30 30 30 20 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
91/79
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
307 AM CDT MON JUN 17 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 307 AM CDT MON JUN 17 2013
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED AN UPPER LOW OFF THE PACIFIC NORTHWEST COAST...RIDGING
BUILDING FROM NEW MEXICO INTO BRITISH COLUMBIA...AND TROUGHING OVER
SOUTHEAST CANADA INTO THE EASTERN GREAT LAKES. WITHIN THE
WEST-NORTHWEST FLOW...TWO SHORTWAVES OF NOTE WERE NEAR FARGO NORTH
DAKOTA AND IN FAR SOUTHWEST SASKATCHEWAN. 700-850MB MOISTURE
TRANSPORT AHEAD OF THE FARGO SHORTWAVE HELPING TO SUPPORT SOME HIGH
BASED SHOWERS ALONG/NORTHEAST OF I-94. TALKING ABOUT HIGH BASED...
00Z MPX AND GRB SOUNDINGS BOTH DEPICTED MIXING UP TO 750MB...WITH
DEEP INVERTED-V APPEARANCE BELOW. THIS DEEP MIXING ALLOWED FOR
SHOWERS THAT MOVED THROUGH MPX AROUND RAOB RELEASE TIME TO PRODUCE
WIND GUSTS OF 30-50KT. THESE SHOWERS WERE MORE VIGOROUS THEN THOSE
OCCURRING NOW...PLUS THEY OCCURRED RIGHT AFTER PEAK HEATING WHEN
MIXING WAS AT ITS MAXIMUM...ALLOWING FOR THE STRONG GUST POTENTIAL.
OTHERWISE...SKIES ARE MOSTLY CLEAR OVER THE FORECAST AREA SOUTH OF A
COLD FRONT EXTENDING FROM NORTHERN MN INTO NORTHERN LOWER MI. 850MB
TEMPS AT 00Z AHEAD OF THE FRONT WERE 14-16C AT MPX...GRB AND
DVN...COMPARED TO 4C BEHIND THE FRONT UP AT PICKLE LAKE IN NORTHWEST
ONTARIO. ALTHOUGH DEEP MIXING EXISTED ON THAT MPX SOUNDING...THE
HIGHER MID LEVEL MOISTURE ALLOWED FOR THE PRECIPITABLE WATER TO JUMP
UP TO 0.93 INCHES AS OF 00Z...COMPARED TO 0.44 12 HOURS EARLIER.
THUS...THERE IS SOME MOISTURE AHEAD OF THE FARGO SHORTWAVE.
MODEL TRENDS FOR TODAY HAVE REALLY SHIFTED THE SHORTWAVE COMING INTO
THE FORECAST AREA NORTH COMPARED TO THE 16.00Z CYCLE. MODEL
CONSENSUS NOW SUGGESTS THAT THE SHORTWAVE NEAR FARGO ENDS UP
CROSSING CLARK COUNTY AT 00Z TUESDAY...COMPARED TO SAY LA CROSSE.
THIS HAS A BIG IMPACT ON PLACEMENT OF PRECIPITATION CHANCES.
WITH THE SHORTWAVE TRACKING FARTHER NORTH TODAY...THE COLD FRONT
ONLY DROPS SOUTH TO MAYBE THE I-94 CORRIDOR BY 00Z. COMBINATION OF
LOW LEVEL CONVERGENCE ON THE FRONT...LOW TO MID LEVEL FRONTOGENESIS
NORTH OF THE FRONT...THE APPROACH OF THE SHORTWAVE TO YIELD SOME
DPVA AND DAYTIME HEATING SHOULD PROVE FAVORABLE FOR NUMEROUS SHOWERS
ALONG/NORTH OF I-94. COULD EVEN SEE SOME ISOLATED/SCATTERED ACTIVITY
SOUTH OF THERE TOWARDS I-90 VERY LATE IN THE DAY AS THE FRONTAL
FORCING APPROACHES. DEEP MIXING AGAIN LOOKS LIKELY TODAY AHEAD OF
THE APPROACHING FRONT. NAM/RAP SOUNDINGS SHOW POTENTIAL OF 7500-9500
FT AGL FROM CLARK COUNTY SOUTHWARD...WHICH RESULTS IN HIGHS IN THE
LOW TO PERHAPS EVEN SOME MID 80S. THIS SHOULD ALLOW DEWPOINTS TO
FALL INTO THE LOW TO MID 50S. COMBINATION OF THE TWO RESULTS IN
0-1KM MLCAPES OF 400-700 J/KG IN THE AREA ALONG/NORTH OF THE FRONT.
ALTHOUGH THIS IS NOT MUCH...IT WILL BE ENOUGH TO BOTH ADD
THUNDERSTORMS AND MAKE THE SHOWERS MORE VIGOROUS. FREEZING LEVELS
ARE LOW...9500-1000 FT AGL AT 21Z WHICH COULD ALLOW FOR SOME
HAIL...BUT THE MINIMAL CAPE WHICH IS TALL AND SKINNY MAY KEEP ANY
HAIL SMALL. BIGGER CONCERN WILL LIKELY BE WIND GIVEN THE DEEP MIXING
YIELDING DEEP INVERTED-V LOOKS ON A SKEW-T. COULD SEE STRONG TO
SEVERE WIND GUSTS...JUST LIKE WHAT WENT THROUGH MINNEAPOLIS AROUND
00Z LAST EVENING.
THE VIGOROUS CONVECTIVE ACTIVITY WILL LIKELY DIMINISH QUICKLY AFTER
00Z AS LOSS OF HEATING KNOCKS DOWN CAPE. HOWEVER...
ISOLATED/SCATTERED SHOWER ACTIVITY MAY PERSIST THROUGH MUCH OF THE
NIGHT AS THE FRONT SLOWLY SINKS SOUTH...AIDED BY LOW TO MID LEVEL
FRONTOGENESIS PERSISTING ALONG/NORTH OF THE FRONT. ADDITIONALLY...
AFTER MIDNIGHT TONIGHT...ATTENTION TURNS TO THE SHORTWAVE OVER
SOUTHWEST SASKATCHEWAN. MODELS HAVE SPED UP THIS SHORTWAVE...PERHAPS
MOVING INTO FAR WESTERN PORTIONS OF THE FORECAST AREA BY 12Z TUESDAY
AS SUGGESTED BY THE 17.00Z GFS. 17.00Z NAM/UKMET ARE JUST SLIGHTLY
SLOWER. IN ANY EVENT...DPVA AND A LOWERING TROPOPAUSE WITH THIS
SHORTWAVE WILL LIKELY HELP STRENGTHEN THE LOW TO MID LEVEL
FRONTOGENESIS IN PLACE ALONG/NORTH OF THE FRONT. THUS...THIS
SHORTWAVE SHOULD HELP PROMOTE KEEPING ISOLATED/SCATTERED ACTIVITY
GOING.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 307 AM CDT MON JUN 17 2013
TUESDAY...ATTENTION IS ON THAT SHORTWAVE APPROACHING FAR WESTERN
PORTIONS OF THE FORECAST AREA AT 12Z. AGAIN...WITH MODELS SPEEDING
UP THE SHORTWAVE...THE WAVE PRETTY MUCH EXITS THE AREA BY
18Z...REACHING NORTHWEST INDIANA BY 00Z. MODELS HAVE COME INTO MUCH
BETTER CONSENSUS ON WHETHER THIS SHORTWAVE WILL PRODUCE
PRECIPITATION...WITH THE 17.00Z NAM/GFS/CANADIAN/UKMET/ECMWF AND
HIRES NMM/ARW ALL NOW DEPICTING SOME LIGHT PRECIPITATION. BELIEVE
THE REASON THE QPF IS LIGHT IS THAT THE MOISTURE TRANSPORT IS NOT
ALL THAT GREAT...AND THE AVAILABLE MOISTURE IS SOMEWHAT LIMITED.
HOWEVER...WITH ALL MODELS DEPICTING A FAIRLY STRONG SHORTWAVE PER
500MB PROGS...THE FORCING SHOULD BE ENOUGH TO SQUEEZE OUT SOME
SHOWERS AND POSSIBLY EVEN A THUNDERSTORM OR TWO ONCE DAYTIME HEATING
GETS GOING. THUS...HAVE ADDED 20-30 PERCENT CHANCES TO THE
FORECAST...HIGHEST TUESDAY MORNING. THESE CHANCES MAY NEED TO BE
INCREASED IN LATER FORECASTS. COMBINATION OF CLOUDS ACCOMPANYING THE
SHORTWAVE AND A NORTHEAST LOW LEVEL FLOW OUT OF HIGH PRESSURE IN
UPPER MICHIGAN WILL YIELD A COOLER DAY. HIGHS MOST LOCATIONS SHOULD
END UP IN THE LOW TO MID 70S.
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...THE UPPER LOW OFF THE
PACIFIC NORTHWEST IS PROGGED TO MOVE INLAND DURING THIS
PERIOD...FORCING RIDGING TO INCREASE DOWNSTREAM OVER THE PLAINS.
THIS SETUP WOULD PLACE THE FORECAST AREA IN SUBSIDENCE EAST OF THE
RIDGE AXIS...FAVORABLE FOR HIGH PRESSURE AT THE SURFACE. THIS IS
TRUE ACCORDING TO MODELS...AND WOULD NORMALLY SUGGEST A DRY
FORECAST. HOWEVER...17.00Z NAM AND TO SOME DEGREE THE GFS THROW A
MONKEY WRENCH INTO THIS PLAN...AS THESE MODELS SHOW A NORTH TO SOUTH
ORIENTED SHORTWAVE BARRELING THROUGH THE RIDGE AND MOVING INTO THE
AREA WEDNESDAY NIGHT. BOTH MODELS END UP BRINGING LIGHT
PRECIPITATION INTO THE AREA. MEANWHILE...THE 17.00Z
ECMWF/CANADIAN/UKMET SHOW A MUCH WEAKER REFLECTION OF THIS SHORTWAVE
AS WELL AS SLOWER SPEED. AS A RESULT...THESE MODELS WOULD FAVOR THE
PREVIOUS DRY FORECAST. HAVE STAYED WITH THE DRY FORECAST FOR
NOW...BUT THIS SHORTWAVE WILL NEED SOME WATCHING. OTHERWISE...A COOL
NIGHT LOOKS ON TAP TUESDAY NIGHT WITH THE HIGH PRESSURE AREA IN
PLACE. SOME OF THE TYPICAL COLDER SPOTS COULD DROP INTO THE LOWER
40S. GRADUAL WARMING OF TEMPERATURES EXPECTED FOR HIGHS WEDNESDAY
AND WEDNESDAY NIGHT WITH THE HIGH PRESSURE AREA SLOWLY DRIFTING OFF
TO THE EAST...AS WELL AS AIRMASS MODIFICATION FROM DAYTIME HEATING
TAKING PLACE.
THURSDAY THROUGH THE WEEKEND...
SIMPLY STATED...MORE SUMMER-LIKE WITH INCREASING HUMIDITY...DEALING
WITH CAP CONCERNS AND POTENTIAL FOR MCSS.
17.00Z ECMWF/GFS/CANADIAN AND GFS ENSEMBLES CONTINUE TO SHOW GOOD
RUN-TO-RUN CONSISTENCY ON THE UPPER LEVEL PATTERN. THE TROUGHING
THAT HAS BEEN PERSISTENT IN SOUTHEAST CANADA IS PROGGED TO LIFT OUT
BEGINNING ON THURSDAY. MEANWHILE THE UPPER LOW IN THE PACIFIC
NORTHWEST SLOWLY EJECTS NORTHEAST INTO SOUTH CENTRAL CANADA ON
SUNDAY. THE MOTIONS OF THE TWO TROUGHS ALLOW FOR A FAIRLY
SUBSTANTIAL WARM/MOIST AIR ADVECTION TO TAKE PLACE ACROSS THE PLAINS
AND TOWARDS THE FORECAST AREA. AS A RESULT...THE POTENTIAL EXISTS
FOR MULTIPLE ROUNDS OF CONVECTION AS VARIOUS MCSS FORM. RUN-TO-RUN
MODEL CONSISTENCY AS WELL AS AGREEMENT ON THE MCS TRACKS IS FAIRLY
LOW...AND TO BE EXPECTED. THE ONLY WELL AGREED UPON MCS APPEARS TO
BE ON FRIDAY INTO SATURDAY WHERE AN MCS FORMS OVER THE DAKOTAS AND
TRACKS EAST INTO NORTHERN WI SAT MORNING. THUS...FOLLOWING A MODEL
CONSENSUS FOR PRECIPITATION CHANCES YIELDS 40-60 PERCENT CHANCES
ACROSS THE FORECAST AREA FOR SATURDAY...HIGHEST TOWARDS NORTHERN WI.
THERE ARE INDICATIONS TOO THAT CAPPING WILL BE AN ISSUE TO
CONTEND WITH AS 700MB TEMPS OVER 12C BEGIN ADVECTING TOWARDS THE
AREA FOR THE WEEKEND.
WE WILL DEFINITELY NEED TO WATCH FOR SEVERE WEATHER AND HEAVY RAIN
HEADING INTO THE WEEKEND...GIVEN THE MCS POTENTIAL AND WARM CLOUD
DEPTHS PROGGED IN THE 3500-4500 FT RANGE.
TEMPERATURES ARE EXTREMELY TRICKY AS THEY DEPEND ON HOW CONVECTION
EVOLVES...ESPECIALLY DAYTIME HIGHS. MODELS HAVE TRENDED WARMER FOR
THURSDAY THROUGH THE WEEKEND...SO HAVE FOLLOWED SUIT AND RAISED
HIGHS. HOWEVER...THESE MAY NEED FURTHER INCREASES IF SAY THE CURRENT
17.00Z ECMWF/GFS ARE CORRECT. THIS IS ESPECIALLY TRUE WHERE ON
SATURDAY THEY BOOST 850MB TEMPS UP TO 20-24C...OR 2 STANDARD
DEVIATIONS ABOVE NORMAL. HIGHS COULD EASILY CLIMB INTO THE LOW TO
POSSIBLY EVEN MID 90S IF THIS COMES TRUE. EVAPOTRANSPORATION AND
MOISTURE ADVECTION SHOULD HELP BOOST DEWPOINTS INTO THE 70S...WHICH
THIS LATENT HEATING WILL KEEP HIGHS FROM GETTING MUCH HIGHER THAN
THAT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1105 PM CDT SUN JUN 16 2013
A WEST-EAST RUNNING SFC BOUNDARY WILL SLOWLY SINK SOUTHWARD ON
MONDAY...AIDED BY AN UPPER LEVEL SHORTWAVE SLIDING ACROSS THE UPPER
MISSISSIPPI RIVER VALLEY. THE BOUNDARY HOLDS MORE TO THE NORTH
THOUGH UNTIL LATER MONDAY NIGHT WHEN A SECONDARY...STRONGER PIECE OF
UPPER LEVEL ENERGY DIPS SOUTHEAST ACROSS THE REGION. INSTABILITY AND
WEAK MOISTURE TRANSPORT MAKES THE BOUNDARY A PRIME PLACE FOR SOME
SCATTERED SHRA/TS. ANY PCPN THAT DOES GET GOING WOULD HAVE THE
CHANCE FOR ENHANCED GUSTINESS...WITH A DRY NEAR SFC LAYER DEPICTED
IN BUFKIT SOUNDINGS FAVORING THE HIGHER GUST POTENTIAL.
EXPECT VFR CONDITIONS FOR MONDAY INTO MONDAY NIGHT...WITH PCPN
CHANCES LIKELY HOLDING OFF UNTIL MONDAY NIGHT - BETTER OVERNIGHT
INTO EARLY TUE MORNING. WILL PUSH THE VCSH SHOWER MENTION PAST
00Z...BUT CONFIDENCE FOR A SHRA/TS IS FOR THE OVERNIGHT HOURS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1105 PM CDT SUN JUN 16 2013
.UPDATE...THIS EVENING
ISSUED AT 609 PM CDT SUN JUN 16 2013
CONVECTION THAT FIRED UP ACROSS WESTERN MINNESOTA REMAINS INTACT
AS IT HEADS INTO TWIN CITIES METRO AREA THIS EVENING. MSP AIRPORT
GUSTED TO NEAR 60 MPH AS IT CAME THROUGH. RADAR RETURNS ARE NOT
THAT IMPRESSIVE...HOWEVER ATMOSPHERIC CONDITIONS ARE CONDUCIVE FOR
STRONG OUTFLOW GUSTS. RAP SOUNDINGS SHOW WELL MIXED LOW-LEVELS /
UP TO 700 MB / AND STEEP LAPSE RATES. DRY AIR ENTRAINMENT IS ALSO
HELPING TO PUT DOWN STRONG TO SEVERE WIND GUSTS. DCAPE IS BETWEEN
1000 TO 1500 J/KG AND THIS EXTENDS INTO PARTS OF SOUTHEAST
MINNESOTA AND WESTERN WISCONSIN. EXPECTING THIS COMPLEX TO
CONTINUE OVER THE NEXT 2 TO 4 HOURS AND THE SEVERE WIND THREAT MAY
PERSIST INTO PARTS OF THE AREA. AT THE VERY LEAST...EXPECTING 30
TO 40 MPH GUSTS. WILL CLOSELY MONITOR THE POTENTIAL FOR SEVERE
GUSTS.
&&
.SHORT TERM...(TONIGHT THROUGH WED NIGHT)
ISSUED AT 219 PM CDT SUN JUN 16 2013
MINOR RAIN THREATS TO START THE WEEK SEEM LIKE THE MAIN FOCUS FOR
THIS FORECAST WITH OTHERWISE FAIRLY QUIET FLOW.
STUNNING FATHERS DAY IN PROGRESS WITH PLENTY OF SUN AND MUCH NEEDED
DRYING. UNFORTUNATELY CANT KEEP RAIN OUT OF THE FORECAST LONG THESE
DAYS AS SHORT WAVE TROUGHS APPROACH IN NORTHWEST FLOW. THESE WAVES
ARE SPINNING OFF CLOSED UPPER LOW MOVING THROUGH SOUTHERN CANADA AND
EVEN THOUGH THERE IS LESS MOISTURE TO WORK WITH...STILL SEEING
CONVECTION UPSTREAM THAT COULD WORK INTO NORTH CENTRAL WISCONSIN AND
EVENTUALLY FURTHER SOUTH INTO MONDAY. CIRRUS BLOWOFF FROM STORM
COMPLEX OVER THE PLAINS WILL ALSO SWEEP THROUGH TONIGHT.
OUTSIDE OF NEAR TERM...MODELS STRUGGLING WITH RESOLUTION OF THESE
EMBEDDED WAVES BUT WITH POSSIBLE STRONGER ENERGY MONDAY...BOUNDARY
AND PROXIMITY TO APPROACHING UPPER LOW...SHOWERS AND A FEW
THUNDERSTORMS LOOK MORE LIKELY BY MONDAY AFTERNOON AND EVENING WITH
MINOR MOST UNSTABLE CAPE. RAIN THAT DOES OCCUR SHOULD REMAIN
SCATTERED AND PROGRESSIVE WITH MODEST NORTHWEST STEERING FLOW.
EVEN THOUGH LAST IN SERIES OF SHORT WAVES COULD IMPACT AREA ON
TUESDAY...DRYING AIRMASS AND SURFACE RIDGE SUGGESTS THIS COULD
COUNTER ANY THREAT FOR ADDITIONAL SHOWERS. WILL KEEP DRY FORECAST
RIDING SINCE CHANCES FOR RAIN TOO SMALL TO MENTION SO FAR.
COOL AIRMASS WILL DIP TEMPERATURES INTO THE 40S IN CENTRAL WISCONSIN
TUESDAY NIGHT WHERE FAVORED VALLEYS COULD SEE A LITTLE FOG. WARM AIR
ADVECTION ALREADY RETURNS BY WEDNESDAY MORNING IN MINNESOTA AND IOWA
BUT BULK OF RAIN SHOULD HOLD OFF UNTIL LATER IN WEEK AS ANY
APPROACHING PRECIPITATION BATTLES DRIER AIR TO THE EAST.
GRADUAL WARMING TREND ALSO TAKES PLACE AS HEIGHTS RISE.
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 219 PM CDT SUN JUN 16 2013
NATIONAL DISCUSSION SUMMARIZED IT WELL WITH THE WORD MESSY REGARDING
THE EXTENDED FORECAST. WHILE MEAN UPPER RIDGE OVER NATIONS MID
SECTION GROWS INITIALLY...SHORT WAVES EJECTING OUT OF TROUGH OVER
PACIFIC NORTHWEST WILL LEAD TO LOW LEVEL FORCING AND RETURN OF LOW
LEVEL MOISTURE AND WARM AIR ADVECTION...ESPECIALLY TO THE WEST OF
AREA. DRIER AIR TO THE EAST WILL BE SHUNTED OFF EVENTUALLY BUT COULD
HOLD BULK OF RAIN THREAT OFF ON THURSDAY...BEFORE SPREADING ACROSS
AREA WIDE BY FRIDAY.
RIDGE FLATTENS QUITE A BIT BY NEXT WEEKEND AND WITH STRONGER SHORT
WAVE ENERGY PASSING ACROSS NORTHERN TIER OF STATES COULD VERY WELL
SEE SEVERAL PROGRESSIVE MESOSCALE CONVECTIVE SYSTEMS /MCS/. HARD TO
PUT ANY IDEA OF TIMING SO GENERAL RAIN CHANCES OF 30 TO 40 PERCENT
LOOK REASONABLE THIS FAR OUT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1105 PM CDT SUN JUN 16 2013
A WEST-EAST RUNNING SFC BOUNDARY WILL SLOWLY SINK SOUTHWARD ON
MONDAY...AIDED BY AN UPPER LEVEL SHORTWAVE SLIDING ACROSS THE UPPER
MISSISSIPPI RIVER VALLEY. THE BOUNDARY HOLDS MORE TO THE NORTH
THOUGH UNTIL LATER MONDAY NIGHT WHEN A SECONDARY...STRONGER PIECE OF
UPPER LEVEL ENERGY DIPS SOUTHEAST ACROSS THE REGION. INSTABILITY AND
WEAK MOISTURE TRANSPORT MAKES THE BOUNDARY A PRIME PLACE FOR SOME
SCATTERED SHRA/TS. ANY PCPN THAT DOES GET GOING WOULD HAVE THE
CHANCE FOR ENHANCED GUSTINESS...WITH A DRY NEAR SFC LAYER DEPICTED
IN BUFKIT SOUNDINGS FAVORING THE HIGHER GUST POTENTIAL.
EXPECT VFR CONDITIONS FOR MONDAY INTO MONDAY NIGHT...WITH PCPN
CHANCES LIKELY HOLDING OFF UNTIL MONDAY NIGHT - BETTER OVERNIGHT
INTO EARLY TUE MORNING. WILL PUSH THE VCSH SHOWER MENTION PAST
00Z...BUT CONFIDENCE FOR A SHRA/TS IS FOR THE OVERNIGHT HOURS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE.......ZT
SHORT TERM...SHEA
LONG TERM....SHEA
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
632 PM CDT SUN JUN 16 2013
.UPDATE...THIS EVENING
ISSUED AT 609 PM CDT SUN JUN 16 2013
CONVECTION THAT FIRED UP ACROSS WESTERN MINNESOTA REMAINS INTACT
AS IT HEADS INTO TWIN CITIES METRO AREA THIS EVENING. MSP AIRPORT
GUSTED TO NEAR 60 MPH AS IT CAME THROUGH. RADAR RETURNS ARE NOT
THAT IMPRESSIVE...HOWEVER ATMOSPHERIC CONDITIONS ARE CONDUCIVE FOR
STRONG OUTFLOW GUSTS. RAP SOUNDINGS SHOW WELL MIXED LOW-LEVELS /
UP TO 700 MB / AND STEEP LAPSE RATES. DRY AIR ENTRAINMENT IS ALSO
HELPING TO PUT DOWN STRONG TO SEVERE WIND GUSTS. DCAPE IS BETWEEN
1000 TO 1500 J/KG AND THIS EXTENDS INTO PARTS OF SOUTHEAST
MINNESOTA AND WESTERN WISCONSIN. EXPECTING THIS COMPLEX TO
CONTINUE OVER THE NEXT 2 TO 4 HOURS AND THE SEVERE WIND THREAT MAY
PERSIST INTO PARTS OF THE AREA. AT THE VERY LEAST...EXPECTING 30
TO 40 MPH GUSTS. WILL CLOSELY MONITOR THE POTENTIAL FOR SEVERE
GUSTS.
&&
.SHORT TERM...(TONIGHT THROUGH WED NIGHT)
ISSUED AT 219 PM CDT SUN JUN 16 2013
MINOR RAIN THREATS TO START THE WEEK SEEM LIKE THE MAIN FOCUS FOR
THIS FORECAST WITH OTHERWISE FAIRLY QUIET FLOW.
STUNNING FATHERS DAY IN PROGRESS WITH PLENTY OF SUN AND MUCH NEEDED
DRYING. UNFORTUNATELY CANT KEEP RAIN OUT OF THE FORECAST LONG THESE
DAYS AS SHORT WAVE TROUGHS APPROACH IN NORTHWEST FLOW. THESE WAVES
ARE SPINNING OFF CLOSED UPPER LOW MOVING THROUGH SOUTHERN CANADA AND
EVEN THOUGH THERE IS LESS MOISTURE TO WORK WITH...STILL SEEING
CONVECTION UPSTREAM THAT COULD WORK INTO NORTH CENTRAL WISCONSIN AND
EVENTUALLY FURTHER SOUTH INTO MONDAY. CIRRUS BLOWOFF FROM STORM
COMPLEX OVER THE PLAINS WILL ALSO SWEEP THROUGH TONIGHT.
OUTSIDE OF NEAR TERM...MODELS STRUGGLING WITH RESOLUTION OF THESE
EMBEDDED WAVES BUT WITH POSSIBLE STRONGER ENERGY MONDAY...BOUNDARY
AND PROXIMITY TO APPROACHING UPPER LOW...SHOWERS AND A FEW
THUNDERSTORMS LOOK MORE LIKELY BY MONDAY AFTERNOON AND EVENING WITH
MINOR MOST UNSTABLE CAPE. RAIN THAT DOES OCCUR SHOULD REMAIN
SCATTERED AND PROGRESSIVE WITH MODEST NORTHWEST STEERING FLOW.
EVEN THOUGH LAST IN SERIES OF SHORT WAVES COULD IMPACT AREA ON
TUESDAY...DRYING AIRMASS AND SURFACE RIDGE SUGGESTS THIS COULD
COUNTER ANY THREAT FOR ADDITIONAL SHOWERS. WILL KEEP DRY FORECAST
RIDING SINCE CHANCES FOR RAIN TOO SMALL TO MENTION SO FAR.
COOL AIRMASS WILL DIP TEMPERATURES INTO THE 40S IN CENTRAL WISCONSIN
TUESDAY NIGHT WHERE FAVORED VALLEYS COULD SEE A LITTLE FOG. WARM AIR
ADVECTION ALREADY RETURNS BY WEDNESDAY MORNING IN MINNESOTA AND IOWA
BUT BULK OF RAIN SHOULD HOLD OFF UNTIL LATER IN WEEK AS ANY
APPROACHING PRECIPITATION BATTLES DRIER AIR TO THE EAST.
GRADUAL WARMING TREND ALSO TAKES PLACE AS HEIGHTS RISE.
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 219 PM CDT SUN JUN 16 2013
NATIONAL DISCUSSION SUMMARIZED IT WELL WITH THE WORD MESSY REGARDING
THE EXTENDED FORECAST. WHILE MEAN UPPER RIDGE OVER NATIONS MID
SECTION GROWS INITIALLY...SHORT WAVES EJECTING OUT OF TROUGH OVER
PACIFIC NORTHWEST WILL LEAD TO LOW LEVEL FORCING AND RETURN OF LOW
LEVEL MOISTURE AND WARM AIR ADVECTION...ESPECIALLY TO THE WEST OF
AREA. DRIER AIR TO THE EAST WILL BE SHUNTED OFF EVENTUALLY BUT COULD
HOLD BULK OF RAIN THREAT OFF ON THURSDAY...BEFORE SPREADING ACROSS
AREA WIDE BY FRIDAY.
RIDGE FLATTENS QUITE A BIT BY NEXT WEEKEND AND WITH STRONGER SHORT
WAVE ENERGY PASSING ACROSS NORTHERN TIER OF STATES COULD VERY WELL
SEE SEVERAL PROGRESSIVE MESOSCALE CONVECTIVE SYSTEMS /MCS/. HARD TO
PUT ANY IDEA OF TIMING SO GENERAL RAIN CHANCES OF 30 TO 40 PERCENT
LOOK REASONABLE THIS FAR OUT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 609 PM CDT SUN JUN 16 2013
VFR CONDITIONS EXPECTED THROUGH THE FORECAST PERIOD AT BOTH
KRST/KLSE. CURRENTLY WATCHING SHOWERS AND ISOLATED THUNDERSTORM
COMPLEX NEAR TWIN CITIES AS IT DIVES SOUTHEAST. COULD IMPACT KRST
AND KLSE IN A FEW HOURS WITH PRIMARILY STRONG OUTFLOW WIND GUSTS.
CONFIDENCE IS HIGHER THAT KRST COULD SEE 30 TO 40 MPH
GUSTS...NOT SURE IF IT WILL HOLD TOGETHER TO IMPACT KLSE. WILL
UPDATE TAF ONCE CONFIDENCE INCREASES THAT THE ENVIRONMENT
CONTINUES TO SUPPORT THE OUTFLOW WINDS.
FOR MONDAY...EAST/WEST SURFACE FRONTAL BOUNDARY WILL SAG SOUTH BY
MONDAY MORNING BUT LIMITED FORCING AND LACK OF MOISTURE POOL WILL
KEEP CONDITIONS BENIGN. BY LATE MORNING INTO THE AFTERNOON
HOURS...A MORE VIGOROUS WAVE DIPPING SOUTH WILL PROMOTE THE
DEVELOPMENT OF A 4 TO 5 KFT CUMULUS FIELD...AND THE THREAT OF
SHOWERS AND ISOLATED THUNDERSTORMS. THE HIGHER COVERAGE OF
PRECIPITATION IS EXPECTED TO BE MAINLY ALONG AND EAST OF THE
MISSISSIPPI RIVER...AND BETWEEN 18-00Z. THINKING THAT KLSE WILL
SEE HIGHER COVERAGE OF CLOUDS AND SHOWERS THAN KRST. OPTED TO NOT
INCLUDE THUNDER MENTION AT THIS POINT SINCE THREAT IS ISOLATED AT
THIS POINT AND THE UNCERTAINTIES IF PRECIPITATION WILL INDEED
IMPACT SITES.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...ZT
SHORT TERM...SHEA
LONG TERM....SHEA
AVIATION...ZT
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
545 PM CDT SAT JUN 15 2013
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 330 PM CDT SAT JUN 15 2013
LATEST RADAR SHOWED A LINE OF SHOWERS AND ISOLATED THUNDERSTORM
MOVING ACROSS SOUTHEAST MINNESOTA AND NORTHEAST IOWA AND WAS
WEAKENING RAPIDLY AS IT APPROACHED THE MISSISSIPPI RIVER.
SCATTERED THUNDERSTORMS WERE ONGOING ACROSS PORTIONS OF NORTH
CENTRAL AND NORTHWEST WISCONSIN. SURFACE OBSERVATIONS INDICATED A
WEAK COLD FRONT EXTENDING FROM SUPERIOR WISCONSIN...SOUTH TO RED
WING MINNESOTA TO AROUND AUSTIN MINNESOTA AND WAS GRADUALLY MOVING
EAST. A WEAKENING MCV WAS MOVING ACROSS THE FORECAST AREA AND WAS
SUPPORTING THE SHOWER/STORM ACTIVITY.
LATEST MESOSCALE ANALYSIS SHOWS 1500 TO 2000 J/KG OF SURFACED
BASED CAPE LINGERING ACROSS MUCH OF THE FORECAST AREA WITH AROUND
100 J/KG OF CIN. WILL HAVE TO KEEP A VERY CLOSE EYE ON THE
CLEARING BEHIND THE MCV TO SEE IF ADDITIONAL SHOWERS AND STORMS
WILL DEVELOP ALONG THE COLD FRONT. 0-6KM SHEAR IS INCREASING
BEHIND THIS FEATURE AS A 500 MB JET SAGS SOUTH INTO THE AREA. THE
FORECAST AREA ALSO IN PROXIMITY TO THE RIGHT ENTRANCE REGION OF A
250 MB JET STRETCHING FROM EASTERN SOUTH DAKOTA THROUGH CENTRAL
MINNESOTA INTO CENTRAL ONTARIO. CANNOT RULE OUT AN ISOLATED STRONG
TO PERHAPS SEVERE THUNDERSTORM LATE THIS AFTERNOON. CURRENTLY
THERE ISN/T MUCH FOR CUMULUS DEVELOPMENT ALONG THE BOUNDARY IN THE
WAKE OF THE MCV SO THINKING OVERALL SEVERE THREAT IS QUICKLY
DIMINISHING. THE COLD FRONT SLIDES SOUTH OF THE FORECAST AREA THIS
EVENING AS HIGH PRESSURE BUILDS IN TONIGHT INTO SUNDAY MORNING.
PLAN ON QUIET AND PLEASANT WEATHER ON SUNDAY WITH HIGH
TEMPERATURES CLIMBING INTO THE LOWER TO MID 80S UNDER PARTLY TO
MOSTLY SUNNY SKIES.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 330 PM CDT SAT JUN 15 2013
A TROUGH IS EXPECTED TO DIVE SOUTHEAST OUT OF SOUTHERN
MANITOBA/CANADA LATE SUNDAY NIGHT THROUGH MONDAY. ALSO...A COLD
FRONT WILL SLIDE SOUTH JUST AHEAD OF THE TROUGH. THE FRONT LOOKS TO
MOVE FROM NORTH TO SOUTH ACROSS THE FORECAST AREA MONDAY AFTERNOON
INTO MONDAY EVENING. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO
DEVELOP LATE SUNDAY NIGHT AND CONTINUE INTO MONDAY AS THE FRONT
AND UPPER TROUGH MOVES THROUGH THE REGION. IF THE SYSTEM SLOWS AND
INSTABILITY CAN BUILD AHEAD OF THE SYSTEM ON MONDAY...A FEW STRONG
TO SEVERE STORMS ARE POSSIBLE. FORECAST SOUNDINGS INDICATE A
RATHER DRY SUB CLOUD LAYER...WITH AN INVERTED V LOOK TO THE
SOUNDING. 0-6 KM BULK SHEAR VALUES OF 30 TO 35 KTS...AND 0-3KM
MUCAPE VALUES IN THE 1200 TO 1500 J/KG ALSO SUPPORT THE POTENTIAL
FOR SEVERE THUNDERSTORMS. THINKING THAT THUNDERSTORMS MONDAY
AFTERNOON MAY HAVE THE POTENTIAL TO PRODUCE DAMAGING WIND GUSTS
AND POSSIBLY LARGE HAIL. THE FRONT MOVES SOUTH OF THE FORECAST
AREA MONDAY EVENING AND SURFACE HIGH PRESSURE BUILDS IN QUICKLY IN
ITS WAKE. NORTHWEST FLOW ALOFT THEN SETS UP ACROSS THE UPPER
MIDWEST TUESDAY THROUGH WEDNESDAY AS A RIDGE BUILDS OVER THE
CENTRAL CONUS. WILL HAVE TO KEEP A CLOSE WATCH ON EMBEDDED
SHORTWAVES WITHIN THE FLOW...WHICH HAVE THE POTENTIAL TO PRODUCE
SHOWERS AND THUNDERSTORMS. THINKING THE SURFACE HIGH SHOULD WIN
OUT AND PROVIDE QUIET WEATHER TUESDAY INTO WEDNESDAY. PLAN ON
HIGHS ON TUESDAY IN THE LOWER TO MID 70S...THEN WARMING SLIGHTLY
ON WEDNESDAY WITH HIGHS CLIMBING INTO THE UPPER 70S. THE UPPER
RIDGE STARTS TO BREAK DOWN THURSDAY THROUGH FRIDAY WITH SEVERAL
EMBEDDED SHORTWAVES MOVING THROUGH IT. WARM SOUTHERLY FLOW SETS UP
AT THE SURFACE ON THURSDAY AS THE HIGH SLIDES OFF TO THE EAST AND
A SURFACE TROUGH DEVELOPS OVER THE CENTRAL/NORTHERN PLAINS. AN
ACTIVE PERIOD IS IN STORE FOR THE FORECAST AREA STARTING LATE
THURSDAY AND POTENTIALLY LASTING INTO THE WEEKEND. LOOKING AT THE
ECMWF SOLUTIONS FOR FRIDAY...A SEVERE WEATHER EVENT MAY OCCUR. A
LOT OF DETAILS TO SORT OUT YET...BUT THIS IS THE TIMEFRAME WHEN
CAPE AND SHEAR PROFILES WOULD SUPPORT SEVERE THUNDERSTORMS.
ALSO...A SHORTWAVE TROUGH IS EXPECTED TO MOVE ACROSS THE AREA AND
COULD TRIGGER THE SHOWERS/STORMS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 545 PM CDT SAT JUN 15 2013
TAF SITES SITTING BETWEEN AREAS OF SHRA/TS EARLY THIS EVENING. SOME
MESO MODELS SUGGEST PCPN COULD DEVELOP BETWEEN THIS SYSTEM BETWEEN
NOW AND 03Z...BUT NOT SOLD ON THIS. THERE IS SOME INSTABILITY AND
THE LATEST RAP POINTS TO SOME LOW LEVEL MOISTURE TRANSPORT TOO.
HOWEVER...NO HINTS OF ANY CU/ENHANCED CLOUDS ACROSS THE LOCAL AREA
PER LATEST SATELLITE IMAGERY. FRONTOGENETIC FORCING LIES
NORTH/SOUTH...WHERE THE CURRENT PCPN RESIDES. SO...WILL OPT FOR DRY
FOR THE EVENING HOURS.
EXPECT CLEARING SKIES LATER TONIGHT AS WEAK HIGH PRESSURE BUILDS IN.
DECOUPLING WINDS LEAD TO THOUGHTS OF FOG. LIGHTER SFC WINDS AT
KLSE...BUT RAP BUFKIT SOUNDINGS STIRRING AT 14 KTS BY 04Z AT 200 FT
AND BOUNDARY LAYER DOESN/T APPEAR OVERLY MOIST. SO...DON/T BELIEVE
FG/BR WILL BE A CONCERN OVERNIGHT. EXPECT VFR CONDITIONS THROUGH
MUCH OF THE DAY SUNDAY.
LATER SUNDAY NIGHT...THE BOUNDARY TO THE NORTH WILL SINK SOUTH WITH
SOME WEAK MOISTURE TRANSPORT ALONG IT. A FEW SHRA/TS COULD SPARK
ALONG THE BOUNDARY...AND COULD IMPACT KRST/KLSE AFTER 06Z. ACTIVITY
WILL LIKELY BE SCATTERED.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM....WETENKAMP
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
336 PM CDT SAT JUN 15 2013
.SHORT TERM...
TONIGHT AND SUNDAY...FORECAST CONFIDENCE...MEDIUM TO HIGH.
SHOWERS AND STORMS ASSOCIATED WITH IOWA/MN SHORT WAVE AND VORTICITY
MAX HAVE WEAKENED OVER IOWA. THIS SYSTEM APPEARS TO BE MOVING
EAST-NORTHEAST. TAIL END OF PRECIP OVER IOWA SHOWS SIGNS OF
SPLITTING AND BLOWING OUT...PER HRRR MODEL RUN AT 16Z. BEST MOISTURE
TRANSPORT WITH LOW LEVEL JET IS FROM THE WEST-SOUTHWEST OVER IOWA
AND ILLINOIS AND MISSOURI. PUTTING THIS ALL TOGETHER...WILL GO WITH
MORE SCATTERED WORDING FOR SHOWERS AND STORMS ACROSS SOUTHERN
WISCONSIN LATE THIS AFTERNOON AND EVENING. WE JUST DON/T SEE DEEP
MOIST CONVECTION AFFECTING ALL PARTS OF OUR COUNTY WARNING AREA AS
PREVIOUSLY THOUGHT PER OLDER MODEL RUNS. BASICALLY..IT LOOKS LIKE
THE PALMYRA SPLIT AGAIN. MODELS DO NOT GENERATE DECENT LOW LEVEL
JET...ONLY SOME 20 TO 25 KNOTS FROM THE WEST-SOUTHWEST. DEEP LAYER
SHEAR REMAINS BELOW 35 KNOTS. SO DO NOT ANTICIPATE SEVERE
STORMS...BUT SOME STRONG STORMS POSSIBLE GIVEN CAPE OF 700 TO 1300
J/KG IN FORECAST SOUNDINGS. THINGS GRADUALLY QUIET DOWN AFTER 1 AM
TONIGHT AFTER 850 AND 700 MB TROUGHS SLIDE EAST.
SUNDAY WILL BE QUIET AS UPPER LEVEL FLOW BECOMES WEST TO NORTHWEST
AND SURFACE HIGH PRESSURE MOVES EAST FROM NORTHERN PLAINS TO IOWA
AND ILLINOIS AREA. MODELS HAVE A DRY COLUMN FORECASTED...AND EXPECT
ONLY SOME DAYTIME SCATTERED CUMULUS CLOUDS WITH HEATING. MODELS HAVE
925 MB TEMPS IN +21C RANGE...WHICH SUGGESTS MAX TEMPS IN LOWER 80S.
SURFACE WINDS WILL BE WEST TO NORTHWEST 10 TO 20 MPH WITH DAYTIME
HEATING AND MIXING TO THE 850 MB LEVEL WHERE WIND SPEEDS WILL BE IN
THE 20 KNOT RANGE.
SUNDAY NIGHT THROUGH TUESDAY...FORECAST CONFIDENCE MEDIUM
A SHORTWAVE TROUGH WILL DROP SEWD FROM THE NRN PLAINS INTO MN AND
NRN WI FOR LATE SUN NT...AND THEN ACROSS WI MON AND MON NT. AT THE
SFC...A COLD FRONT WILL DROP SWD INTO CENTRAL WI BY EARLY MON
AFTERNOON AND THEN PROGRESS SWD TO THE IL BORDER BY EARLY MON
EVENING. IF A SUFFICIENT N-S PRESSURE GRADIENT DEVELOPS...A
PNEUMONIA FRONT WILL BE GENERATED AND SWEEP SSWWD ACROSS THE WRN
SHORE OF LAKE MI AND ERN WI...AS THE NAM INDICATES. TEMPS WILL
DROP FROM THE LOWER 80S INTO THE 50S LAKESIDE. IF THE PRESSURE
GRADIENT REMAINS WEAKER LIKE THE ECMWF OR GFS...MORE OF A GRADUAL
CHANGE WILL OCCUR IN THE WINDS AND TEMPS. THE CONVERGENCE ALONG
THE COLD FRONT ALONG WITH THE APPROACHING SHORTWAVE TROUGH SHOULD
PROVIDE A GOOD TRIGGER FOR CONVECTION AS WELL. THERE ARE FAIRLY
LARGE MLCAPE DIFFERENCES ON THE MODELS BUT BELIEVE AT LEAST 1000
J/KG WILL OCCUR WITH MDT DEEP LAYER SHEAR. THE TSTORMS WILL
HOWEVER QUICKLY MOVE EWD INTO THE COOLER AIR BEHIND THE FRONT
LIMITING ANY STRONG OR SVR POTENTIAL TO A QUICK PULSE STORM.
NELY WINDS AND COLD ADVECTION WILL THEN BRING A COOL BUT PLEASANT
TUESDAY WITH HIGH PRESSURE CENTERED OVER THE NRN GREAT LAKES. SOME
MODELS HAVE ANOTHER SHORTWAVE TROUGH DIVING SEWD FROM MN TOWARD IL
ON TUE WHICH WOULD BRING CLOUDS AND POSSIBLY LGT PCPN. BEST
COMBINATION OF LIFT AND MOISTURE HOWEVER MAY STAY JUST TO THE WEST
AND WILL KEEP DRY FOR NOW.
.LONG TERM...
WEDNESDAY THROUGH SATURDAY...FORECAST CONFIDENCE MEDIUM
HIGH PRESSURE WILL PREVAIL OVER THE LOWER GREAT LAKES AND MID
ATLANTIC STATES WED AND THU WHILE LEE SIDE TROUGHING OCCURS OVER
THE HIGH PLAINS IN RESPONSE TO A LARGE UPPER LOW MOVING INTO THE
PACIFIC NW. SRN WI WILL REMAIN DRY WED-THU DUE TO THE CLOSE
PROXIMITY TO THE HIGH AND LOW ATMOSPHERIC MOISTURE...BUT WITH A
WARMING TREND ON LGT SLY WINDS AND FULL SUNSHINE.
TSTORM CHANCES TO THEN INCREASE AT THE END OF THE WEEK AS THE
TROUGH OF LOW PRESSURE MOVES EAST ACROSS THE PLAINS BUT WEAKENS AS
THE UPPER TROUGH DE-AMPLIFIES AND LIFTS MORE INTO CANADA. THIS
RESULTS IN AN APPROACHING WARM FRONT BECOMING STATIONARY OVER THE
AREA WITH WARM...HUMID...AND UNSTABLE CONDITIONS.
&&
.AVIATION/00Z TAFS/...
WEAK SURFACE LOW PRESSURE AND COLD FRONT FORECAST TO MOVE ACROSS
SOUTHERN WISCONSIN TONIGHT. SCATTERD BANDS OF SHOWERS AND STORMS
WILL MOVE WEST TO EAST ACROSS THE AREA. GENERALLY VFR CONDITIONS
EXPECTED OUTSIDE OF THE THUNDERSTORMS. UNDER THE STORMS VISIBILITIES
COULD DROP TO 3 TO 5 MILES WITH SOME FOG MIXED IN DUE TO DEWPOINTS
IN THE 60S. GUSTS TO 30 KNOTS POSSIBLE WITH THE STORMS.
&&
.MARINE....
NOT MUCH GOING ON WITH THE WINDS AND WAVES OVER THE NEARSHORE ZONES.
EAST TO SOUTHEAST ONSHORE FLOW SATURDAY AFTERNOON WILL TRANSITION TO
A SOUTH TO SOUTHWEST FLOW OVERNIGHT AS COLD FRONT APPROACHES. AFTER
THE WEAK COLD FRONT THE WINDS WILL BECOME OFFSHORE. THERE IS A 2 TO
4 HOUR WINDOW SATURDAY EVENING FOR FOG DUE TO COOL WATER TEMPS WITH
MOIST AIR OVER LAND MOVING OUT OVER THE LAKE...BUT NOT CONFIDENT TO
PUT THIS INTO FORECAST. UPDATE ON FORECAST WOULD BE NEEDED THIS
EARLY THIS EVENING IF IT STILL LOOKS LIKE IT WILL HAPPEN.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TONIGHT/SUNDAY AND AVIATION/MARINE...KAPELA
SUNDAY NIGHT THROUGH SATURDAY...GEHRING
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
142 PM CDT SAT JUN 15 2013
.UPDATE...LOWERED CHANCES OF PRECIP FIRST HALF OF AFTERNOON WITH
SYSTEM HAVING MOVED OUT OF AREA. NEXT SYSTEMM WITH SHORT WAVE OVER
WESTERN IOWA WILL REACH AREAS WEST OF MADISON LATER THIS
AFTERNOON...SO WENT WITH LIKELY WORDING LATE AFTERNOON WEST OF
MADISON. THIS SYSTEM WILL TRUCK ACROSS SOUTHERN WISCONSIN THIS
EVERNING...BUT HRRR MODEL SUGGEST SOME BREAKING UP AS IT DOES. IN
ANY CASE...SHOWERS AND STORMS LIKELY SOUTHERN WISCONSIN THIS EVENING
THEN GRADUALLY DRYING OUT AFTER MIDNIGHT.
&&
.AVIATION/18Z TAFS/...VFR CONDITIONS TO CONTINUE INTO THIS EVENING
AS MID/HIGH CLOUDS GRADUALLY THICKEN OVER THE AREA IN RESPONSE TO
INCREASING UPSTREAM WARM AIR AND MOISTURE ADVECTION. STILL EXPECT
SCT THUNDERSTORMS TO DEVELOP WEST TO EAST LATE AFTERNON INTO EVENING
HOURS...AND THEN BECOME LESSER IN NUMBERS AFTERNOON MIDNIGHT
TONIGHT. MVFR VSBYS WITH THE THUNDERSTORMS. MAYBE SOME GUSTS TO 30
KNOTS WITH THE STORMS.
&&
..PREVIIOUS DISCUSSION... /ISSUED 455 AM CDT SAT JUNE 15 2013
.TODAY AND TONIGHT...FORECAST CONFIDENCE...MEDIUM.
DIMINISHING TREND TO SHOWERS AND A FEW THUNDERSTORMS AS REMNANTS OF
MCS MOVES INTO DRIER AIR ACROSS THE REGION EARLY THIS MORNING...AND
AWAY FROM FOCUS OF WEAKENING LOW-LEVEL JET. EXPECT A BREAK IN THE
PRECIPITATION BEHIND MCV THIS MORNING...THEN INCREASING CHANCES THIS
AFTERNOON AND EVENING WITH FORCING AHEAD OF SHORT WAVE TROUGH THAT
CROSSES REGION THIS EVENING.
EXPECT SCATTERED TO NUMEROUS SHOWERS AND STORMS TO RE-FIRE THIS
AFTERNOON INTO THE EVENING AS ENHANCED SYNOPTIC SCALE FORCING MOVES
ACROSS SRN WI IN RESPONSE TO RIGHT ENTRANCE REGION OF UPPER
JET...AND LOW LEVEL CONVERGENCE ALONG SFC TROUGH/COLD FRONT. SOME
QUESTION AS TO WHERE STRONGEST STORMS WILL BE LOCATED WITH MODEL
DIFFERENCES WITH STRENGTH/LOCATION OF LOW-LEVEL JET. MUCH WILL BE
PREDICATED ON AMOUNT OF CLOUD COVER LINGERING BEHIND MORNING
PRECIPITATION LIMITING DESTABILIZATION. WESTERN AREAS HAVE A BETTER
CHANCE TO HEAT OUT AND REALIZE 1000-1300 J/KG CAPE ON FORECAST
SOUNDINGS WITH 40 KTS OF SHEAR BRINGING POTENTIAL FOR SEVERE
THUNDERSTORMS TO SUPPORT DAY ONE SLIGHT RISK. OVERALL FOCUS LOOKS TO
BE SOUTH OF FORECAST AREA...SO WILL GO WITH LIKELY POPS ACROSS THE
SOUTH...TAPERING TO CHANCE POPS IN NRN COUNTIES. PRECIPITATION
CHANCES DROP OFF WITH PASSAGE OF TROUGH AND SURFACE FRONT WHICH
CLEARS EASTERN CWA AROUND 12Z SUNDAY.
.SUNDAY - CONFIDENCE...MEDIUM
WARM WESTERLY FLOW EXPECTED. 925 TEMPS IN THE 20-22C RANGE.
SHORTWAVE OF NOTE SHIFTS WELL EAST WITH BROAD CYCLONIC 500 MILLIBAR
FLOW ACROSS NORTHERN WI. WILL KEEP DRY FORECAST AND GO WITH WARM
TEMPS IN THE 80-84 RANGE.
.MONDAY - CONFIDENCE...MEDIUM
COLD FRONT DROPS IN FROM THE NORTH. SURFACE BASED CAPES FROM THE NAM
BLOSSOM TO OVER 2000 J/KG WITH CIN VALUES OF JUST 56. POTENTIAL FOR
SOME ENTRANCE REGION UPPER DYNAMICS ALONG WITH THE INFLUENCE OF A
500 MILLIBAR SHORTWAVE RIDING IN FROM THE NORTHWEST WITH A PASSAGE
IN THE 18-00Z TIME FRAME. 0-6KM SHEAR DECENT INTO EARLY
AFTERNOON...0-1KM SHEAR WEAK. MID LEVEL LAPSE RATES UNIMPRESSIVE. SO
THE SEE TEXT FROM SPC ON THE DAY 3 OUTLOOK LOOKS REASONABLE.
CERTAINLY NOT A TEXTBOOK SVR CASE BUT SOME POSITIVE PARAMETERS FOR
SOME CONVECTION ON THE STRONGER SIDE. CWASP VALUES IN THE 60S.
.TUESDAY THROUGH THURSDAY - CONFIDENCE...MEDIUM
HIGH PRESSURE EXPECTED TO DOMINATE THIS PERIOD WITH QUIET
CONDITIONS. COOLEST DAY TUESDAY WITH NORTHEAST WINDS...THEN AS HIGH
SHIFTS EAST...GRADUAL WARMING EXPECTED AS WINDS TURN MORE TO THE
SOUTH. DIURNALLY DRIVEN LAKE BREEZE ON WEDNESDAY AND THURSDAY AS
SYNOPTIC FLOW NOT STRONG ENOUGH TO NEGATE THE POTENTIAL.
.FRIDAY - CONFIDENCE...MEDIUM
REASONABLE AGREEMENT BETWEEN THE GFS AND ECMWF TO BRING THE NEXT
DECENT CHANCE OF THUNDERSTORMS. SHORTWAVE RIDES THE UPPER RIDGE AND
SOME WARM ADVECTION NOTED AS WELL. CWASP NUMBERS U60S/L70S ON THE
ECMWF AND L/M 60S FROM THE GFS.
AVIATION/12Z TAFS/...
JUST A FEW INSTANCES OF VSBYS LOWERING TO MVFR WITH THE HEAVIER
SHOWERS OF DIMINISHING AREA OF SHOWERS AND ISOLATED THUNDERSTORMS
CROSSING THE REGION EARLY THIS MORNING. EASTERN TAF SITES HAVE THE
BEST CHANCE TO SEE THUNDER THROUGH 15Z WITH DIMINISHING LIGHT RAIN
SHOWERS AT KMSN. VFR CONDITIONS AS PCPN WILL END BY LATE MORNING
WITH PASSAGE OF CONVECTIVE VORT...WITH SHOWERS AND THUNDERSTORMS
REDEVELOPING LATER THIS AFTERNOON INTO THIS EVENING AHEAD OF AN
APPROACHING COLD FRONT WITH WIDESPREAD MVFR CONDITIONS WITH THE
SHOWERS AND STORMS. WILL TREND WITH THE QUICKER IMPROVEMENT IN CIGS
REFLECTED IN GFS MOS AFTER 16/06Z.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...REM
SUNDAY THROUGH FRIDAY...COLLAR
UPDATE...KAPELA
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
105 PM CDT SAT JUN 15 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 309 AM CDT SAT JUN 15 2013
MAIN FORECAST CONCERN IS FLASH FLOOD AND SEVERE WEATHER POTENTIAL
FOR LATER TODAY.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED AN UPPER LOW OVER CENTRAL SASKATCHEWAN WITH TROUGHING
EXTENDING SOUTH INTO WESTERN NORTH DAKOTA...RIDGING FROM LOUISIANA
NORTHWARD INTO WESTERN ONTARIO...AND TROUGHING OVER SOUTHEAST CANADA
INTO NEW ENGLAND. ALSO OF NOTE WAS A SHORTWAVE TROUGH OVER WESTERN
KS INTO THE TX PANHANDLE. PLENTIFUL MOISTURE NOTED ON GOES DERIVED
PRECIPITABLE WATER IMAGERY WITHIN THE RIDGING...WITH VALUES OF
1.5-1.8 INCHES FROM THE SOUTHERN PLAINS INTO THE FORECAST AREA.
THESE OVER THE FORECAST AREA ARE ALMOST 180 PERCENT OF NORMAL. A
30-40 KT 850MB JET STREAMING FROM THE TX PANHANDLE INTO IOWA PER
PROFILER AND VWP DATA HAS HELPED BRING THAT MOISTURE TOWARDS US.
ACCOMPANYING THE MOISTURE HAS BEEN WARMER AIR...WITH 850MB TEMPS OF
21-27C ACROSS NEBRASKA AND KANSAS COMPARED TO 12-14C OVER THE
FORECAST AREA PER 00Z RAOBS. ADDITIONALLY...ON THE NOSE OF THIS LOW
LEVEL JET...CONVECTION ENCOMPASSES MUCH OF THE FORECAST AREA
SOUTHWARD INTO NORTHEAST MISSOURI. TO THE NORTHWEST...CLEARER SKIES
AND DRIER AIR IS PRESENT OVER THE DAKOTAS...BEHIND A COLD FRONT
SITUATED IN WESTERN MN.
MODELS ARE IN GOOD AGREEMENT FLATTENING THE RIDGE AXIS OVER
MINNESOTA TODAY...IN RESPONSE TO THE TROUGHING OVER WESTERN NORTH
DAKOTA TRAVERSING EAST INTO NORTHERN LAKE SUPERIOR. THIS TROUGHING
WILL EVENTUALLY HELP PUSH THE COLD FRONT OVER WESTERN MN THROUGH THE
FORECAST AREA...WHICH ACCORDING TO MODEL CONSENSUS OCCURS BETWEEN
00-06Z SUNDAY. ONCE THE FRONT PASSES...THE DRIER AIR SEEN OVER THE
DAKOTAS WILL FLOW IN AND END THE THREAT FOR PRECIPITATION. UNTIL
THEN...THE FORECAST IS SOMEWHAT PROBLEMATIC TRYING TO FIGURE OUT
CONVECTIVE EVOLUTION.
FOLLOWING THE TYPICAL CONVECTIVE CYCLE...THE CURRENT CONVECTION
BEING SUPPORTED BY THE NOCTURNAL ENHANCEMENT TO THE LOW LEVEL JET
SHOULD WEAKEN THROUGH THE MORNING. MODELS INDICATE THIS HAPPENING AS
WELL...WITH 850MB MOISTURE TRANSPORT DIMINISHING BY 15Z.
ADDITIONALLY...THIS 850MB MOISTURE TRANSPORT BECOMES ORIENTED MORE
WEST TO EAST...EVEN BY 12Z AS THE UPPER RIDGE AXIS BEGINS TO
FLATTEN. THERE COULD EASILY BE A 4-6 HOUR BREAK IN PRECIPITATION
OVER THE FORECAST AREA...SAY BETWEEN 14-19/20Z. THEN...DIURNAL
HEATING COMBINED WITH THE COLD FRONT MOVING THROUGH THE FORECAST
AREA SHOULD INITIATE NEW CONVECTION. IN ADDITION...THAT SHORTWAVE
TROUGH PRESENTLY OVER WESTERN KS INTO THE TX PANHANDLE LOOKS TO LIFT
INTO IA...HELPING TO REFOCUS AND INCREASE 850MB MOISTURE TRANSPORT
TOWARDS NORTHEAST IA...ALONG WITH BRINGING DPVA FOR FORCING WITH IT.
ANOTHER FORCING MECHANISM FOR CONVECTION THIS AFTERNOON IS AN UPPER
JET STREAK ON THE ORDER OF 85-115KT PASSING ACROSS THE NORTHERN HALF
OF MN INTO LAKE SUPERIOR AT 21Z AND 00Z. THIS JET STREAK WOULD PUT
UPPER LEVEL DIVERGENCE OVER THE AREA. 15.05Z HRRR AND 15.00Z HIRES
ARW/NMM MODELS PRETTY MUCH AGREE WITH THE SCENARIO WRITTEN HERE.
ANY CONVECTION SHOULD THEN SLOWLY SINK SOUTHEAST DURING THE
EVENING...AIDED BY A COMBINATION OF CONVECTIVE OUTFLOWS AND THE
PASSAGE OF THE COLD FRONT.
REGARDING SEVERE WEATHER POTENTIAL...CONVECTION THIS MORNING SHOULD
MOSTLY BE A HEAVY RAIN CONCERN GIVEN DEEP WARM CLOUD DEPTHS AND
TALL...SKINNY CAPE. THE AFTERNOON AND EARLY EVENING HOURS NEED SOME
WATCHING. FIRST OFF...INSTABILITY IS PLENTY. RAP MLCAPE PROGS AT 21Z
WITH ML DEWPOINTS OF 65-70F AND SURFACE TEMPS IN THE 82-87F RANGE
RESULT IN VALUES OF 2500 TO 4000 J/KG...HIGHEST ACROSS SOUTHERN
PORTIONS OF THE FORECAST AREA. THIS CAPE IS FAT TOO...REFLECTED BY
NCAPE VALUES CLIMBING TO 0.25-0.35...SUGGESTING RAPID THUNDERSTORM
GROWTH. THE TEMPERATURES FORECAST BY THE RAP ARE LIKELY TOO
HIGH...SINCE PLENTY OF CLOUDS SHOULD EXIST. MID 70S TO NEAR 80
SUGGESTED BY MOST GUIDANCE SEEM MORE REASONABLE. STILL...THIS
RESULTS IN 1500-3000 J/KG OF MLCAPE. BEST 0-6KM SHEAR LIES AROUND
THE FRONT...ON THE ORDER OF 40-50 KT...WITH THE BULK OF THIS SHEAR
RESULTING FROM A 50 KT WIND MAX AT 6 KM ASSOCIATED WITH THAT
SHORTWAVE TROUGH LIFTING NORTHEAST INTO IOWA. ADDITIONALLY...
FREEZING LEVELS ARE PROGGED LOWER THIS AFTERNOON...FROM 12000-13500
FT AGL NORTHWEST TO SOUTHEAST. THUS...THINKING THERE SHOULD BE
POTENTIAL FOR EITHER MULTICELLS OR SUPERCELLS CAPABLE OF PRODUCING
LARGE HAIL. THERE IS ALSO A DRY WEDGE OF AIR BETWEEN 600-800MB WHICH
COULD PROVE FAVORABLE FOR DAMAGING WINDS. LASTLY...ALTHOUGH FREEZING
LEVELS ARE LOWER...THE PLENTIFUL CAPE AND HIGH EQUILIBRIUM LEVELS
ALONG WITH STORM MOTIONS WHICH LOOK LIKE THEY MAY BE KIND OF SLOW
BRINGS UP A HEAVY RAIN CONCERN. THUS...THE FLASH FLOOD WATCH STILL
LOOKS GOOD.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 309 AM CDT SAT JUN 15 2013
SUNDAY THROUGH MONDAY NIGHT...
MAIN FOCUS IS ON THE UPPER LOW OVER CENTRAL SASKATCHEWAN...WHICH
MODELS REMAIN CONSISTENT IN DROPPING THROUGH THE FORECAST AREA
DURING THE DAY MONDAY AS A WEAKENING SHORTWAVE TROUGH. THE CURRENT
COLD FRONT PROGRESSING THROUGH THE FORECAST AREA THIS AFTERNOON AND
EVENING LOOKS TO SHUNT A LOT OF THE MOISTURE AWAY FROM THE AREA.
THIS IS REFLECTED BY PRECIPITABLE WATER VALUES OF 0.6-0.7 INCHES
DURING THE DAY SUNDAY. THUS...SUNDAY LOOKS DRY AND WITH 850MB TEMPS
RUNNING 13-15C...HIGHS SHOULD EASILY CLIMB INTO THE LOW 80S. THERE
IS A SURGE OF 700-850MB MOISTURE TRANSPORT FROM THE NORTHWEST SUNDAY
NIGHT...ASSOCIATED WITH THE SHORTWAVE TROUGH APPROACHING...BUT HARD
TO SAY IF IT IS GOING TO BE ENOUGH TO PRODUCE PRECIPITATION. THE
15.00Z GFS/CANADIAN/NAM ALL BRING SCATTERED SHOWERS AND
THUNDERSTORMS THROUGH THE FORECAST AREA BETWEEN 06Z MONDAY AND
MONDAY AFTERNOON...BUT THE 15.00Z ECMWF IS MOSTLY DRY AND HAS BEEN
FOR MANY RUNS. AFTER THE FRONT GOES THROUGH MONDAY...DRIER AND
COOLER AIR ASSOCIATED WITH CANADIAN HIGH PRESSURE INVADES THE AREA
MONDAY NIGHT...RESULTING IN A DRY NIGHT.
TUESDAY THROUGH FRIDAY NIGHT...
MODELS REMAIN CONSISTENT THROUGH THURSDAY ON SHOWING TROUGHING OVER
THE PACIFIC NORTHWEST...RIDGING FROM THE NORTHWEST TERRITORIES OF
CANADA INTO THE SOUTHERN PLAINS...AND TROUGHING OVER EASTERN CANADA
AND THE EASTERN GREAT LAKES. THIS KEEPS THE FORECAST AREA UNDER THE
INFLUENCE OF HIGH PRESSURE AND MAINLY DRY...OUTSIDE OF A SHORTWAVE
PROGGED TO DROP THROUGH NORTHWEST FLOW ON THURSDAY AND PERHAPS BRING
A FEW SHOWERS AND THUNDERSTORMS. IT SHOULD BE NOTED THAT THE 15.00Z
ECMWF IS SHOWING SOMETHING NEW...A SHORTWAVE DROPPING THROUGH
WESTERN PORTIONS OF THE FORECAST AREA ON TUESDAY AND PRODUCING
PRECIPITATION. SINCE THIS IS A NEW FEATURE...HAVE HELD ONTO A DRY
FORECAST. AS WE HEAD TOWARDS THE WEEKEND...THE 15.00Z ECMWF HAS
CHANGED FROM ITS PREVIOUS RUNS AND NOW HAS COME INTO MORE ALIGNMENT
WITH THE GFS. BASICALLY...THE PACIFIC NORTHWEST TROUGH IS SUGGESTED
TO EJECT EAST-NORTHEAST...SPLITTING THROUGH THE RIDGE IN PLACE. THIS
RESULTS IN A WARM ADVECTION PATTERN DOWNSTREAM TOWARDS THE FORECAST
AREA...BRINGING THE CONCERN FOR CONVECTION. GOOD MODEL AGREEMENT
RESULTS IN PRECIPITATION CHANCES IN AT LEAST 30-40 PERCENT RANGE FOR
FRIDAY...AND EVEN HIGHER FOR FRIDAY NIGHT. WE WILL HAVE TO WATCH HOW
THIS ALL EVOLVES TOWARDS THE END OF THE WEEK SINCE THE PATTERN WOULD
FAVOR SEVERE WEATHER AND HEAVY RAIN POTENTIAL.
&&
.AVIATION...THROUGH 18Z SUNDAY
101 PM CDT SAT JUN 15 2013
PRIMARY AVIATION CONCERN IS WITH THE PASSAGE OF THUNDERSTORMS THIS
AFTERNOON INTO EARLY EVENING. EXPECT ABOUT A 2 HOUR PERIOD OF
SHOWERS AND THUNDERSTORMS WITH SOME MVFR CIGS/VSBYS. A FEW OF THE
STRONGER EMBEDDED STORMS WILL PRODUCE GUSTY WINDS AS WELL IN THE
30-40KT RANGE. THIS WAS INCLUDED IN THE TAF FORECASTS FOR BOTH
KRST AND KLSE. WINDS WILL VARY FROM SOUTH PRIOR TO STORMS...TO
WEST DURING STORMS...TO EAST BEHIND STORMS...AND THEN AS THE FRONT
MOVES THROUGH...A SWITCH TO NORTHWEST. TRIED TO ADD THIS DETAIL TO
THE TAFS AS WELL.
BEYOND THIS EVENING...LOOKS LIKE IT WILL CLEAR OUT. VFR EXPECTED
INTO SUNDAY.
&&
.HYDROLOGY...
ISSUED AT 309 AM CDT SAT JUN 15 2013
WIDESPREAD SHOWERS WITH EMBEDDED THUNDERSTORMS DEVELOPED EARLY THIS
MORNING ACROSS MUCH OF THE FORECAST AREA. HOWEVER...WITH LESS
INSTABILITY AVAILABLE COMPARED TO THE EVENING HOURS...THE MAJORITY
OF THE FORECAST AREA AS OF 08Z HAS SEEN LESS THAN 0.25 INCH OF
RAINFALL. THERE HAVE BEEN ISOLATED LOCATIONS OVER 1 INCH...INCLUDING
IN FLOYD COUNTY IA WHICH DOES NOT NEED THE RAIN. SO FAR MOST RIVERS
HAVE NOT RESPONDED TO THE RAIN.
PRECIPITATION IS ON THE WANE AS OF 08Z...AND WE MAY END UP WITH A
DECENT DRY PERIOD...SAY FROM 14-20Z. AFTER 20Z...MORE THUNDERSTORMS
ARE EXPECTED TO MOVE INTO THE FORECAST AREA...FROM AN APPROACHING
COLD FRONT COMING FROM THE WEST AND A SHORTWAVE LIFTING OUT OF
SOUTHWEST KS INTO IOWA. THESE WILL BE HEAVY RAIN PRODUCERS...WHICH
GIVEN THE ANTECEDENT MOIST SOILS COULD RESULT IN FLASH FLOODING.
THEREFORE THE FLASH FLOOD WATCH CONTINUES. THE FLASH FLOOD THREAT
SHOULD SUBSIDE DURING THE EVENING HOURS...MAYBE JUST SLIGHTLY AFTER
THE 00Z END TIME OF THE WATCH...AS THUNDERSTORMS WEAKEN AND DROP
SOUTHEAST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...FLASH FLOOD WATCH THROUGH THIS EVENING FOR MNZ094-095.
IA...FLASH FLOOD WATCH THROUGH THIS EVENING FOR IAZ008>010-018-019-
029-030.
&&
$$
SHORT TERM...AJ
LONG TERM....AJ
AVIATION...MW
HYDROLOGY....AJ
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1104 AM EDT MON JUN 17 2013
.SYNOPSIS...
A COLD FRONT MOVES INTO THE REGION TODAY...THEN STALLS OUT NEARBY
INTO TUESDAY. A COLD FRONT PUSHES SOUTHEAST OF THE REGION TUESDAY
NIGHT...WITH A WEAK WAVE OF LOW PRESSURE PASSING SOUTH OF THE
REGION ON WEDNESDAY. HIGH PRESSURE RETURNS FOR THE REST OF THE
WEEK. A WARM FRONT APPROACHES THE AREA ON SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATED GRIDS TO REFLECT CURRENT TRENDS. LOWERED SKY COVER THROUGH
THE EARLY AFTERNOON AS MID-HIGH LEVEL CLOUDS HAVE SHIFTED
OFFSHORE. FORECAST HIGH TEMPERATURES AROUND 5 DEGREES ABOVE NORMAL
ACCEPTED.
OTHERWISE...A WEAK 700-500 HPA SHORTWAVE CURRENTLY OVER THE OHIO VALLEY
MOVES ACROSS THE AREA THIS AFTERNOON/EVENING. THIS COUPLED WITH A
WEAK COLD FRONT SAGGING INTO THE AREA SHOULD SERVE AS THE TRIGGER
FOR A FEW SHOWERS/TSTORMS...ESPECIALLY ACROSS THE INTERIOR.
1000-1500 J/KG OF CAPE IS FORECAST BY THE RAP/NAM/SREF. LATEST 12Z
NAM AND HRRR RUNS SHOW SCATTERED CONVECTION DEVELOPING NORTH OF
THE REGION AND MOVING INTO THE INTERIOR THIS EVENING. MODEL
SOUNDINGS INDICATE DRY AIR THAT MAY SERVE TO INHIBIT CONVECTIVE
DEVELOPMENT. HAVE CONTINUED TO FORECAST CHANCE POPS ACROSS THE
INTERIOR WITH SLIGHT CHANCE POPS FURTHER SOUTH DUE TO AFTERNOON SEA
BREEZES AND LOWER INSTABILITY.
IN ADDITION TO THE AFOREMENTIONED CAPE...FORECAST TO HAVE 40-50
KT OF BULK SHEAR. A STRONG TO POSSIBLY SEVERE STORM CANNOT BE
RULED OUT ACROSS THE INTERIOR WITH FORECAST BULK SHEAR VALUES 40-50 KT
AND WET BULB ZERO HEIGHTS 7500-9500 FT COULD SEE SOME SMALL TO
POSSIBLY LARGE HAIL ALONG WITH GUSTY WINDS.
THERE IS A MODERATE RISK OF RIP CURRENTS INTO THIS EVENING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
ANY CONVECTION SHOULD DIE OUT EARLY THIS EVENING WITH EXIT OF
700-500 HPA SHORTWAVE AND LOSS OF SOLAR HEATING. FOR LOWS TONIGHT
USED A BLEND OF MAV/MET GUIDANCE WITH NAM 2-METER
TEMPERATURES...WITH READINGS FORECAST TO BE A FEW DEGREES ABOVE NORMAL.
700-500 HPA NORTHERN STREAM TROUGH AXIS MOVES IN TUESDAY...AND
SHOULD ACT ON STALLED FRONTAL BOUNDARY TO PRODUCE AT LEAST SCT SHRA/TSRA
ACROSS THE TRI-STATE. STILL SOME VARIATION ON THE MODELS IN TERMS
OF COVERAGE/STRENGTH SO KEPT POPS AT CHANCE FOR NOW.
MAIN QUESTION IS STRENGTH OF INSTABILITY. NAM HAS 1500-2500 J/KG
OF CAPE...WITH THE GFS ONLY AROUND 500 J/KG AND THE ECMWF
SOMEWHERE IN BETWEEN.
THE REGION WILL ALSO BE IN THE RIGHT REAR QUADRANT OF A 75+ KT 300
HPA JET...HAVE 40-50 KT OF BULK SHEAR...AND FAIRLY DECENT LOW
LEVEL HELICITY. SO IF THE HIGHER INSTABILITY IN THE NAM CAN BE
REALIZED...HAVE THE POTENTIAL FOR SOME STRONG TO POSSIBLY SEVERE
STORMS. IF NOT...THEN ONCE AGAIN SHOULD SEE MAINLY AIRMASS
TSTMS...WITH MAYBE AN ISOLD LOW TOPPED SUPERCELL LIKE TODAY.
FOR HIGHS TUESDAY USED A BLEND OF MIXING DOWN FROM 900 HPA NEAR
THE COAST TO 825 HPA WELL INLAND...WITH NAM 2-METER TEMPERATURES
AND A BLEND OF MAV/MET GUIDANCE. EXPECT HIGHS TO BE AROUND 5
DEGREES ABOVE NORMAL.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
MODELS COMING INTO SOMEWHAT BETTER AGREEMENT WITH EVOLUTION OF THE
MAIN SYNOPTIC FEATURES FOR MIDWEEK...WITH A STRONG UPPER LOW CURLING
THROUGH EASTERN CANADA AND A COLD FRONT PUSHING SOUTHEAST OF THE
REGION TUESDAY NIGHT. THIS SHOULD HAVE ANY SHRA/TSRA ACTIVITY
TUESDAY NIGHT WEAKENING AND GRADUALLY SINKING SE OF THE REGION.
FOR WED...MODELS ARE KEYING IN ON SHORTWAVE ENERGY CURRENTLY OVER
THE CANADIAN ROCKIES...ROUNDING THE BASE OF THE NE US TROUGH...AND
HELPING TO INDUCE A WAVE OF LOW PRESSURE ALONG THE COLD FRONT. AT
THIS POINT...IT APPEARS WE SHOULD BE MAINLY DRY...BUT COULD BE ON
THE NORTHERN FRINGE OF ANY PRECIP WITH THIS FEATURE. IT WILL HAVE TO
BE WATCHED. IF NOTHING ELSE...A BIT MORE CLOUD COVER AND ONSHORE
FLOW TO THE NORTH OF THE LOW WOULD HOLD TEMPS BELOW SEASONABLE
LEVELS.
THEREAFTER...MODELS IN DECENT AGREEMENT WITH MEAN TROUGHING
CONTINUING OVER THE NORTHEAST...WITH CANADIAN HIGH PRESSURE GRADUALLY
BUILDING INTO THE REGION AND IN CONTROL THROUGH SATURDAY. THIS WILL
RESULT IN FAIR AND SEASONABLE WARM CONDITIONS THROUGH THE PERIOD.
WEAK PIECES OF SHORTWAVE ENERGY ROUNDING THE BASE OF THE TROUGH
COULD SET OFF ISOLATED PULSE SHRA/TSRA ACTIVITY EACH AFT/EVE...MAINLY
OFF THE NW HIGHER ELEVATIONS.
HEIGHTS MAY BEGIN TO BUILD THIS WEEKEND INTO EARLY NEXT WEEK...WITH
A TREND TOWARDS MORE SUMMER LIKE WEATHER. THIS WOULD ALSO BRING
POTENTIAL FOR MCS ACTIVITY AS THE REGION LIES ON THE SOUTHERN EDGE
OF THE WESTERLIES.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
A SURFACE TROUGH REMAINS OVER THE TERMINALS TODAY. WEAK COLD FRONT
THEN DROPS DOWN FROM NW THIS EVE AND MAY PRODUCE SCT CONVECTION...
PRIMARILY NORTH AND WEST OF THE NYC TERMINALS FROM 22Z TO 02Z.
OTHERWISE...AN ISOLATED AFTERNOON SHOWER OR TSTM IS NOT OUT OF THE
QUESTION. TIMING AND PLACEMENT TOO LOW TO INCLUDE IN THE TAFS FOR
NOW.
SOUTHWEST WINDS LESS THAN 10 KT TO START. SPEEDS GRADUALLY INCREASE
THIS MORNING AND INTO THE AFTERNOON WITH SPEEDS BETWEEN 8-15 KT
SUSTAINED. SEA BREEZES LIKELY AT THE COASTAL TERMINALS THIS
AFTERNOON. OCCASIONAL GUSTS TO NEAR 20 KT ARE POSSIBLE TODAY.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED TO ADJUST TIMING OF
ANY WIND SHIFTS AND TO ADD POSSIBLE LATE DAY CONVECTION. AN OCCASIONAL
GUST TO 20 KT CAN NOT BE RULED OUT.
KLGA FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED TO ADJUST TIMING OF
ANY WIND SHIFTS AND TO ADD POSSIBLE LATE DAY CONVECTION. AN
OCCASIONAL GUST INTO THE UPPER TEENS CAN NOT BE RULED OUT.
KEWR FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED TO ADD POSSIBLE
LATE DAY CONVECTION.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED TO ADD POSSIBLE
LATE DAY CONVECTION.
KHPN FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED TO ACCOUNT FOR LATE
DAY SEABREEZE AND TO ADD CONVECTION.
KISP FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED TO ADJUST TIMING OF
ANY WIND SHIFTS. AN OCCASIONAL GUST INTO THE UPPER TEENS CAN NOT BE
RULED OUT.
.OUTLOOK FOR 12Z TUE THROUGH FRI...
.TUE...SCT SHOWERS AND ISOLD-SCT TSTMS COULD BRING MVFR OR LOWER
CONDITIONS.
.WED-FRI...VFR.
&&
.MARINE...
WAVEWATCH RUNNING AROUND 1 FT TOO HIGH...SO ADJUSTED DOWN A FT OR
SO.
WITH A RELATIVELY LIGHT PRESSURE GRADIENT OVER THE REGION EXPECT
WINDS TO BE 10 KT OR LESS THROUGH TUESDAY...OUTSIDE OF AFTERNOON
SEABREEZES EACH DAY AND ANY THUNDERSTORMS. WAVES...EVEN WITH A
PERSISTENT 2 FT SWELL SHOULD REMAIN BELOW SCA LEVELS ON THE OCEAN
WATERS THROUGH TUESDAY.
MARGINAL SCA SEAS ARE POSSIBLE WEDNESDAY WITH A WEAK WAVE OF LOW
PRESSURE MOVING TO THE SOUTH OF THE REGION. OTHERWISE...SUB SCA
CONDITIONS ARE LIKELY FOR MID THROUGH LATE WEEK AS HIGH PRESSURE BUILDS
IN.
&&
.HYDROLOGY...
BASIN AVERAGE QPF FROM ANY SHRA/TSTMS THIS AFTERNOON/EARLY EVENING
SHOULD BE LESS THAN .1 INCHES. WITH PRECIPITABLE WATERS AROUND 1
INCH...THE PROBABILITY OF LOCALLY HEAVY RAINFALL...AND HENCE ANY
SIGNIFICANT HYDROLOGIC IMPACT IS LOW.
THERE IS THE POTENTIAL FOR 1/3-2/3 AN INCH OF BASIN AVERAGE
QPF...WITH LOCALLY HIGHER AMOUNTS POSSIBLE WITH CONVECTION
TUESDAY/TUESDAY EVENING. WITH PRECIPITABLE WATERS OF 1.25-1.5
INCHES...THERE IS THE POTENTIAL FOR LOCALLY HEAVY RAINFALL WITH
ANY STRONGER CONVECTION. THIS COULD CAUSE MINOR FLOODING OF
URBAN/POOR DRAINAGE AREAS.
THE PROBABILITY FOR WIDESPREAD SIGNIFICANT RAINFALL IS LOW FROM
THE MIDDLE THROUGH THE END OF THE WEEK.
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.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1026 AM EDT MON JUN 17 2013
.SYNOPSIS...
A COLD FRONT MOVES INTO THE REGION TODAY...THEN STALLS OUT NEARBY
INTO TUESDAY. A COLD FRONT PUSHES SOUTHEAST OF THE REGION TUESDAY
NIGHT...WITH A WEAK WAVE OF LOW PRESSURE PASSING SOUTH OF THE
REGION ON WEDNESDAY. HIGH PRESSURE RETURNS FOR THE REST OF THE
WEEK. A WARM FRONT APPROACHES THE AREA ON SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATED GRIDS TO REFLECT CURRENT TRENDS. LOWERED SKY COVER THROUGH
THE EARLY AFTERNOON AS MID-HIGH LEVEL CLOUDS HAVE SHIFTED
OFFSHORE. FORECAST HIGH TEMPERATURES AROUND 5 DEGREES ABOVE NORMAL
ACCEPTED.
OTHERWISE...A WEAK 700-500 HPA SHORTWAVE CURRENTLY OVER THE OHIO VALLEY
MOVES ACROSS THE AREA THIS AFTERNOON/EVENING. THIS COUPLED WITH A
WEAK COLD FRONT SAGGING INTO THE AREA SHOULD SERVE AS THE TRIGGER
FOR A FEW SHOWERS/TSTORMS...ESPECIALLY ACROSS THE INTERIOR.
1000-1500 J/KG OF CAPE IS FORECAST BY THE RAP/NAM/SREF. LATEST 12Z
NAM AND HRRR RUNS SHOW SCATTERED CONVECTION DEVELOPING NORTH OF
THE REGION AND MOVING INTO THE INTERIOR THIS EVENING. MODEL
SOUNDINGS INDICATE DRY AIR THAT MAY SERVE TO INHIBIT CONVECTIVE
DEVELOPMENT. HAVE CONTINUED TO FORECAST CHANCE POPS ACROSS THE
INTERIOR WITH SLIGHT CHANCE POPS FURTHER SOUTH DUE TO AFTERNOON SEA
BREEZES AND LOWER INSTABILITY.
IN ADDITION TO THE AFOREMENTIONED CAPE...FORECAST TO HAVE 40-50
KT OF BULK SHEAR. A STRONG TO POSSIBLY SEVERE STORM CANNOT BE
RULED OUT ACROSS THE INTERIOR WITH FORECAST BULK SHEAR VALUES 40-50 KT
AND WET BULB ZERO HEIGHTS 7500-9500 FT COULD SEE SOME SMALL TO
POSSIBLY LARGE HAIL ALONG WITH GUSTY WINDS.
THERE IS A MODERATE RISK OF RIP CURRENTS INTO THIS EVENING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
ANY CONVECTION SHOULD DIE OUT EARLY THIS EVENING WITH EXIT OF
700-500 HPA SHORTWAVE AND LOSS OF SOLAR HEATING. FOR LOWS TONIGHT
USED A BLEND OF MAV/MET GUIDANCE WITH NAM 2-METER
TEMPERATURES...WITH READINGS FORECAST TO BE A FEW DEGREES ABOVE NORMAL.
700-500 HPA NORTHERN STREAM TROUGH AXIS MOVES IN TUESDAY...AND
SHOULD ACT ON STALLED FRONTAL BOUNDARY TO PRODUCE AT LEAST SCT SHRA/TSRA
ACROSS THE TRI-STATE. STILL SOME VARIATION ON THE MODELS IN TERMS
OF COVERAGE/STRENGTH SO KEPT POPS AT CHANCE FOR NOW.
MAIN QUESTION IS STRENGTH OF INSTABILITY. NAM HAS 1500-2500 J/KG
OF CAPE...WITH THE GFS ONLY AROUND 500 J/KG AND THE ECMWF
SOMEWHERE IN BETWEEN.
THE REGION WILL ALSO BE IN THE RIGHT REAR QUADRANT OF A 75+ KT 300
HPA JET...HAVE 40-50 KT OF BULK SHEAR...AND FAIRLY DECENT LOW
LEVEL HELICITY. SO IF THE HIGHER INSTABILITY IN THE NAM CAN BE
REALIZED...HAVE THE POTENTIAL FOR SOME STRONG TO POSSIBLY SEVERE
STORMS. IF NOT...THEN ONCE AGAIN SHOULD SEE MAINLY AIRMASS
TSTMS...WITH MAYBE AN ISOLD LOW TOPPED SUPERCELL LIKE TODAY.
FOR HIGHS TUESDAY USED A BLEND OF MIXING DOWN FROM 900 HPA NEAR
THE COAST TO 825 HPA WELL INLAND...WITH NAM 2-METER TEMPERATURES
AND A BLEND OF MAV/MET GUIDANCE. EXPECT HIGHS TO BE AROUND 5
DEGREES ABOVE NORMAL.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
MODELS COMING INTO SOMEWHAT BETTER AGREEMENT WITH EVOLUTION OF THE
MAIN SYNOPTIC FEATURES FOR MIDWEEK...WITH A STRONG UPPER LOW CURLING
THROUGH EASTERN CANADA AND A COLD FRONT PUSHING SOUTHEAST OF THE
REGION TUESDAY NIGHT. THIS SHOULD HAVE ANY SHRA/TSRA ACTIVITY
TUESDAY NIGHT WEAKENING AND GRADUALLY SINKING SE OF THE REGION.
FOR WED...MODELS ARE KEYING IN ON SHORTWAVE ENERGY CURRENTLY OVER
THE CANADIAN ROCKIES...ROUNDING THE BASE OF THE NE US TROUGH...AND
HELPING TO INDUCE A WAVE OF LOW PRESSURE ALONG THE COLD FRONT. AT
THIS POINT...IT APPEARS WE SHOULD BE MAINLY DRY...BUT COULD BE ON
THE NORTHERN FRINGE OF ANY PRECIP WITH THIS FEATURE. IT WILL HAVE TO
BE WATCHED. IF NOTHING ELSE...A BIT MORE CLOUD COVER AND ONSHORE
FLOW TO THE NORTH OF THE LOW WOULD HOLD TEMPS BELOW SEASONABLE
LEVELS.
THEREAFTER...MODELS IN DECENT AGREEMENT WITH MEAN TROUGHING
CONTINUING OVER THE NORTHEAST...WITH CANADIAN HIGH PRESSURE GRADUALLY
BUILDING INTO THE REGION AND IN CONTROL THROUGH SATURDAY. THIS WILL
RESULT IN FAIR AND SEASONABLE WARM CONDITIONS THROUGH THE PERIOD.
WEAK PIECES OF SHORTWAVE ENERGY ROUNDING THE BASE OF THE TROUGH
COULD SET OFF ISOLATED PULSE SHRA/TSRA ACTIVITY EACH AFT/EVE...MAINLY
OFF THE NW HIGHER ELEVATIONS.
HEIGHTS MAY BEGIN TO BUILD THIS WEEKEND INTO EARLY NEXT WEEK...WITH
A TREND TOWARDS MORE SUMMER LIKE WEATHER. THIS WOULD ALSO BRING
POTENTIAL FOR MCS ACTIVITY AS THE REGION LIES ON THE SOUTHERN EDGE
OF THE WESTERLIES.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
A SURFACE TROUGH REMAINS OVER THE TERMINALS TODAY.
SOUTHWEST WINDS LESS THAN 10 KT TO START. SPEEDS GRADUALLY INCREASE
THIS MORNING AND INTO THE AFTERNOON WITH SPEEDS BETWEEN 8-15 KT
SUSTAINED. SEA BREEZES LIKELY AT THE COASTAL TERMINALS THIS
AFTERNOON. OCCASIONAL GUSTS TO NEAR 20 KT ARE POSSIBLE TODAY.
AN AFTERNOON SHOWER OR TSTM POSSIBLE INLAND. TIMING AND PLACEMENT
TOO LOW TO INCLUDE IN THE TAFS FOR NOW.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED TO ADJUST TIMING OF
ANY WIND SHIFTS. AN OCCASIONAL GUST TO 20 KT CAN NOT BE RULED OUT.
KLGA FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED TO ADJUST TIMING OF
ANY WIND SHIFTS. AN OCCASIONAL GUST INTO THE UPPER TEENS CAN NOT BE
RULED OUT.
KEWR FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED TO ADJUST TIMING OF
ANY WIND SHIFTS.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED TO ADJUST TIMING OF
ANY WIND SHIFTS.
KHPN FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED TO ADJUST TIMING OF
ANY WIND SHIFTS.
KISP FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED TO ADJUST TIMING OF
ANY WIND SHIFTS. AN OCCASIONAL GUST INTO THE UPPER TEENS CAN NOT BE
RULED OUT.
.OUTLOOK FOR 12TUE THROUGH FRI...
.TUE...SCT SHOWERS AND ISOLD-SCT TSTMS COULD BRING MVFR OR LOWER
CONDITIONS.
.WED-FRI...VFR.
&&
.MARINE...
WAVEWATCH RUNNING AROUND 1 FT TOO HIGH...SO ADJUSTED DOWN A FT OR
SO.
WITH A RELATIVELY LIGHT PRESSURE GRADIENT OVER THE REGION EXPECT
WINDS TO BE 10 KT OR LESS THROUGH TUESDAY...OUTSIDE OF AFTERNOON
SEABREEZES EACH DAY AND ANY THUNDERSTORMS. WAVES...EVEN WITH A
PERSISTENT 2 FT SWELL SHOULD REMAIN BELOW SCA LEVELS ON THE OCEAN
WATERS THROUGH TUESDAY.
MARGINAL SCA SEAS ARE POSSIBLE WEDNESDAY WITH A WEAK WAVE OF LOW
PRESSURE MOVING TO THE SOUTH OF THE REGION. OTHERWISE...SUB SCA
CONDITIONS ARE LIKELY FOR MID THROUGH LATE WEEK AS HIGH PRESSURE BUILDS
IN.
&&
.HYDROLOGY...
BASIN AVERAGE QPF FROM ANY SHRA/TSTMS THIS AFTERNOON/EARLY EVENING
SHOULD BE LESS THAN .1 INCHES. WITH PRECIPITABLE WATERS AROUND 1
INCH...THE PROBABILITY OF LOCALLY HEAVY RAINFALL...AND HENCE ANY
SIGNIFICANT HYDROLOGIC IMPACT IS LOW.
THERE IS THE POTENTIAL FOR 1/3-2/3 AN INCH OF BASIN AVERAGE
QPF...WITH LOCALLY HIGHER AMOUNTS POSSIBLE WITH CONVECTION
TUESDAY/TUESDAY EVENING. WITH PRECIPITABLE WATERS OF 1.25-1.5
INCHES...THERE IS THE POTENTIAL FOR LOCALLY HEAVY RAINFALL WITH
ANY STRONGER CONVECTION. THIS COULD CAUSE MINOR FLOODING OF
URBAN/POOR DRAINAGE AREAS.
THE PROBABILITY FOR WIDESPREAD SIGNIFICANT RAINFALL IS LOW FROM
THE MIDDLE THROUGH THE END OF THE WEEK.
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.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MALOIT/NV
NEAR TERM...DS
SHORT TERM...MALOIT
LONG TERM...NV
AVIATION...BC
MARINE...MALOIT/NV
HYDROLOGY...MALOIT/NV
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
617 AM EDT MON JUN 17 2013
.SYNOPSIS...
HIGH PRESSURE OFF THE SOUTHEAST COAST HAS SHIFTED FARTHER EASTWARD
AHEAD OF A WEAK FRONTAL ZONE MOVING SOUTHWARD AND INTO THE FORECAST
AREA. THE FRONT AND ASSOCIATED MOISTURE WILL DOMINATE THE FORECAST
AREA/S WEATHER THROUGH MUCH OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE MID-LEVEL SHORTWAVE TROUGH APPROACHING THE FORECAST AREA THIS
MORNING HAS REMOVED THE CAPPING THAT HAS BEEN DOMINATE DURING THE
PAST FEW DAYS. MOISTURE HAS INCREASED AHEAD OF THE DIFFUSE FRONT
DROPPING SOUTHWARD AND TOWARD THE FORECAST AREA. BELIEVE THE
SHOWERS MOVING INTO THE FORECAST AREA FROM THE WEST EARLY THIS
MORNING ARE MAINLY ASSOCIATED WITH THE MID-LEVEL SHORTWAVE
TROUGH. THE HIGH-RESOLUTION MODELS SHOW COVERAGE DIMINISHING AS
THESE SHOWERS MOVE INTO THE FORECAST AREA THIS MORNING. THEREFORE...
WE DID NOT FORECAST CATEGORICAL POPS THROUGHOUT THE AREA.
FORECASTED POPS OF 50 TO NEAR 100 PERCENT WITH THE HIGHEST POPS
FOR NOW IN THE SOUTHWEST PART BASED ON RADAR TRENDS AND HRRR MODEL.
THE NAM AND GFS SHOW PRECIPITABLE WATER AROUND 2 INCHES THIS
AFTERNOON. THE HIGH MOISTURE AND HEATING SHOULD HELP SUPPORT
THUNDERSTORMS BUT COVERAGE MAY BE LIMITED BECAUSE LIFT ASSOCIATED
THIS MORNING/S SHORTWAVE TROUGH SHOULD BE EAST OF THE FORECAST
AREA. THE HIGH RESOLUTION MODELS INDICATE SCATTERED COVERAGE.
CLOUDINESS SHOULD LIMIT INSTABILITY TODAY. THE NAM DISPLAYS
SURFACE-BASED LI/S -4 TO -5 TODAY. THE THREAT OF SEVERE
THUNDERSTORMS APPEARS LOW BECAUSE OF THE LIMITED INSTABILITY. AN
AVERAGE OF THE NAM AND GFS PLUS THE SREF MEAN SUPPORT GENERAL RAIN
AMOUNTS NEAR ONE-HALF OF AN INCH. HEAVY RAIN MAY OCCUR BECAUSE OF
THE HIGH PRECIPITABLE WATER AND POSSIBLE TRAINING. LEANED TOWARD
THE COOLER TEMPERATURE GUIDANCE TODAY BECAUSE OF CLOUDINESS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
HIGH MOISTURE ASSOCIATED WITH THE DIFFUSE EAST-WEST ORIENTED FRONT
WILL CONTINUE. THE MODELS KEEP BROAD UPPER-LEVEL TROUGHING WITH A
SERIES OF SHORTWAVE TROUGHS MOVING THROUGH THE FLOW OVER THE
FORECAST AREA. EXPECT NUMEROUS SHOWERS AND THUNDERSTORMS. LEANED
TOWARD THE HIGHER GUIDANCE POPS. THE COOLER HIGH TEMPERATURE
GUIDANCE APPEARS BETTER BECAUSE OF EXPECTED CLOUDINESS. THE LOW
TEMPERATURE GUIDANCE WAS CONSISTENT.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
THE GFS AND ECMWF DISPLAY THE FRONT REMAINING NEAR THE FORECAST
AREA THROUGH THE MEDIUM-RANGE PERIOD. THERE HAS BEEN INCONSISTENCY
IN THE PLACEMENT OF DEEPER MOISTURE. THE GFS ENSEMBLE MEANS AND
OPERATIONAL GFS MOS SUPPORT CHANCE POPS THROUGH THE PERIOD.
EXPECT HIGH TEMPERATURES NEAR OR A LITTLE BELOW CLIMATOLOGY.
&&
.AVIATION /10Z MONDAY THROUGH FRIDAY/...
A WEAK SHORTWAVE CONTINUES TO MAINTAIN AN AREA OF SHOWERS WITH A FEW
EMBEDDED THUNDERSTORMS CURRENTLY OVER NORTHERN GA MOVING EASTWARD.
SOME OF THE SHOWERS MAY MOVE OVER AGS/DNL. WILL INCLUDE A TEMPO
GROUP FOR BOTH AGS AND DNL FOR SHRA UNTIL 14Z. AFTER ANY MORNING
RESTRICTIONS...VFR EXPECTED TODAY OUTSIDE OF ANY CONVECTION. A
DEEPENING UPPER TROUGH AND INCREASING ATMOSPHERIC MOISTURE IS
EXPECTED TO LEAD TO SCATTERED THUNDERSTORMS MONDAY
AFTERNOON...MAINLY AFTER 18Z. HAVE MENTION SHRA AFTER 21Z AT ALL
TAF SITES BUT TSRA MAY BE POSSIBLE AS WELL. WILL CONTINUE MENTION
OF SHRA IN THE TAFS TOWARDS THE END OF THE TAF PERIOD AS A SLOW-
MOVING COLD FRONT APPROACHES FROM THE OH RIVER VALLEY.
EXTENDED AVIATION OUTLOOK...CHANCE OF MAINLY AFTERNOON/EVENING
THUNDERSTORMS. CHANCE OF LATE NIGHT/EARLY MORNING FOG/STRATUS.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
612 AM EDT MON JUN 17 2013
.SYNOPSIS...
HIGH PRESSURE OFF THE SOUTHEAST COAST HAS SHIFTED FARTHER EASTWARD
AHEAD OF A WEAK FRONTAL ZONE MOVING SOUTHWARD AND INTO THE FORECAST
AREA. THE FRONT AND ASSOCIATED MOISTURE WILL DOMINATE THE FORECAST
AREA/S WEATHER THROUGH MUCH OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE MID-LEVEL SHORTWAVE TROUGH APPROACHING THE FORECAST AREA THIS
MORNING HAS REMOVED THE CAPPING THAT HAS BEEN DOMINATE DURING THE
PAST FEW DAYS. MOISTURE HAS INCREASED AHEAD OF THE DIFFUSE FRONT
DROPPING SOUTHWARD AND TOWARD THE FORECAST AREA. BELIEVE THE
SHOWERS MOVING INTO THE FORECAST AREA FROM THE WEST EARLY THIS
MORNING ARE MAINLY ASSOCIATED WITH THE MID-LEVEL SHORTWAVE
TROUGH. THE HIGH-RESOLUTION MODELS SHOW COVERAGE DIMINISHING AS
THESE SHOWERS MOVE INTO THE FORECAST AREA THIS MORNING. THEREFORE...
WE DID NOT FORECAST CATEGORICAL POPS THROUGHOUT THE AREA.
FORECASTED POPS OF 50 TO NEAR 100 PERCENT WITH THE HIGHEST POPS
FOR NOW IN THE SOUTHWEST PART BASED ON RADAR TRENDS AND HRRR MODEL.
THE NAM AND GFS SHOW PRECIPITABLE WATER AROUND 2 INCHES THIS
AFTERNOON. THE HIGH MOISTURE AND HEATING SHOULD HELP SUPPORT
THUNDERSTORMS BUT COVERAGE MAY BE LIMITED BECAUSE LIFT ASSOCIATED
THIS MORNING/S SHORTWAVE TROUGH SHOULD BE EAST OF THE FORECAST
AREA. THE HIGH RESOLUTION MODELS INDICATE SCATTERED COVERAGE.
CLOUDINESS SHOULD LIMIT INSTABILITY TODAY. THE NAM DISPLAYS
SURFACE-BASED LI/S -4 TO -5 TODAY. THE THREAT OF SEVERE
THUNDERSTORMS APPEARS LOW BECAUSE OF THE LIMITED INSTABILITY. AN
AVERAGE OF THE NAM AND GFS PLUS THE SREF MEAN SUPPORT GENERAL RAIN
AMOUNTS NEAR ONE-HALF OF AN INCH. HEAVY RAIN MAY OCCUR BECAUSE OF
THE HIGH PRECIPITABLE WATER AND POSSIBLE TRAINING. LEANED TOWARD
THE COOLER TEMPERATURE GUIDANCE TODAY BECAUSE OF CLOUDINESS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
HIGH MOISTURE ASSOCIATED WITH THE DIFFUSE EAST-WEST ORIENTED FRONT
WILL CONTINUE. THE MODELS KEEP BROAD UPPER-LEVEL TROUGHING WITH A
SERIES OF SHORTWAVE TROUGHS MOVING THROUGH THE FLOW OVER THE
FORECAST AREA. EXPECT NUMEROUS SHOWERS AND THUNDERSTORMS. LEANED
TOWARD THE HIGHER GUIDANCE POPS. THE COOLER HIGH TEMPERATURE
GUIDANCE APPEARS BETTER BECAUSE OF EXPECTED CLOUDINESS. THE LOW
TEMPERATURE GUIDANCE WAS CONSISTENT.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
THE GFS AND ECMWF DISPLAY THE FRONT REMAINING NEAR THE FORECAST
AREA THROUGH THE MEDIUM-RANGE PERIOD. THERE HAS BEEN INCONSISTENCY
IN THE PLACEMENT OF DEEPER MOISTURE. THE GFS ENSEMBLE MEANS AND
OPERATIONAL GFS MOS SUPPORT CHANCE POPS THROUGH THE PERIOD.
EXPECT HIGH TEMPERATURES NEAR OR A LITTLE BELOW CLIMATOLOGY.
&&
.AVIATION /10Z MONDAY THROUGH FRIDAY/...
A WEAK SHORTWAVE CONTINUES TO MAINTAIN AN AREA OF SHOWERS WITH A FEW
EMBEDDED THUNDERSTORMS CURRENTLY OVER NORTHERN GA MOVING EASTWARD.
SOME OF THE SHOWERS MAY MOVE OVER AGS/DNL. AFTER ANY MORNING
RESTRICTIONS...VFR EXPECTED MONDAY OUTSIDE OF ANY CONVECTION. A
DEEPENING UPPER TROUGH AND INCREASING ATMOSPHERIC MOISTURE IS
EXPECTED TO LEAD TO SCATTERED THUNDERSTORMS MONDAY
AFTERNOON...MAINLY AFTER 18Z. HAVE MENTION SHRA AFTER 21Z AT ALL
TAF SITES BUT TSRA MAY BE POSSIBLE AS WELL. WILL CONTINUE MENTION
OF SHRA IN THE TAFS TOWARDS THE END OF THE TAF PERIOD AS A SLOW-
MOVING COLD FRONT APPROACHES FROM THE OH RIVER VALLEY.
EXTENDED AVIATION OUTLOOK...CHANCE OF MAINLY AFTERNOON/EVENING
THUNDERSTORMS. CHANCE OF LATE NIGHT/EARLY MORNING FOG/STRATUS.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1012 AM CDT MON JUN 17 2013
.DISCUSSION...
ISSUED 1010 AM CDT MON JUN 17 2013
EARLY MORNING FOG HAS LARGELY LIFTED...WITH JUST A BIT OF HAZE
LINGERING NEAR THE INDIANA BORDER. LARGE CIRRUS SHIELD SPREADING
OVER MOST OF THE FORECAST AREA...ALTHOUGH A BAND OF ALTOCUMULUS IS
ALONG THE I-70 CORRIDOR. THIS IS IN THE SAME GENERAL AREA AS A
WEAK SURFACE BOUNDARY...AND IS THE MOST LIKELY LOCATION FOR ANY
CONVECTION TO DEVELOP...MAINLY DURING THE AFTERNOON HOURS. WITH A
BROAD POOL OF DEW POINTS NEAR 70 ALONG THE I-72 CORRIDOR...
SCATTERED STORMS ARE ALSO POSSIBLE THERE WITH THE BOUNDARY NOT TOO
FAR AWAY...BUT THEY SHOULD NOT BE THAT ORGANIZED. ANOTHER BOUNDARY
DROPPING INTO THE NORTHWEST PART OF THE FORECAST AREA MAY ALSO
TRIGGER A COUPLE SHOWERS/STORMS THIS AFTERNOON AS WELL IN THAT
AREA.
HAVE SENT SOME UPDATED ZONES/GRIDS...MAINLY TO UPDATE THE
PRECIPITATION TRENDS.
GEELHART
&&
.AVIATION...
ISSUED 645 AM CDT MON JUN 17 2013
AREAS OF FOG WITH IFR TO MVFR CONDITIONS AT PIA AND BMI...LOCALLY
DENSE ALONG I-72 AT SPI...DEC AND CMI WITH LIFR TO VLIFR
CONDITIONS...TO OCCUR UNTIL 13Z/8 AM WITH FOG LIFTING BEFORE
14Z/9 AM. SCATTERED CUMULUS CLOUDS OF 3-5K FT TO DEVELOP LATER
THIS MORNING AND AFTERNOON WITH SCATTERED-BROKEN CIRRUS CLOUDS AT
25K FT. ISOLATED SHOWERS AND THUNDERSTORMS TO DEVELOP MAINLY SOUTH
OF I-72 THIS AFTERNOON NEAR A WEAK BOUNDARY AND BE CLOSEST IMPACT
TO SPI AND DEC AIRPORTS WHERE VCSH. SCATTERED CUMULUS CLOUDS
DISSIPATE AT SUNSET WITH SCATTERED CIRRUS CLOUDS. COULD BE PATCHY
FOG AGAIN OVERNIGHT WITH MVFR VSBYS POSSIBLE AFTER 07Z BUT NOT AS
WIDESPREAD AS EARLY THIS MORNING SINCE LARGER TEMPERATURE/DEWPOINT
SPREADS EXPECTED. WINDS TO REMAIN FAIRLY LIGHT UNDER 10 KTS NEXT
24 HOURS...WITH LIGHT AND VARIABLE TO CALM WINDS EARLY THIS
MORNING BECOMING WSW 5-7 KTS BY AFTERNOON AND DIMINISHING LIGHT
AGAIN AFTER SUNSET TONIGHT.
07
&&
.PREV DISCUSSION...
ISSUED 252 AM CDT MON JUN 17 2013
SHORT TERM...TODAY THROUGH WEDNESDAY
VERY WEAK SURFACE BOUNDARY EXTENDING ACROSS SOUTH-CENTRAL ILLINOIS
WILL BE THE PRIMARY FOCUSING MECHANISM FOR SCATTERED THUNDERSTORMS
TODAY. WITH ONE UPPER-WAVE PASSING WELL TO THE NORTH ACROSS THE
GREAT LAKES AND ANOTHER TRACKING TO THE S/SW INTO THE LOWER OHIO
RIVER VALLEY...VERY LITTLE UPPER SUPPORT WILL BE IN PLACE FOR
WIDESPREAD CONVECTION ACROSS CENTRAL ILLINOIS. DESPITE LACK OF
UPPER DYNAMICS...VERY MOIST AIR MASS IN PRESENCE OF WEAK SURFACE
FORCING WILL BE ENOUGH TO TRIGGER A FEW SHOWERS/THUNDERSTORMS
LATER TODAY. HRRR SUGGESTS DEVELOPMENT AROUND MIDDAY...ESPECIALLY
IN CLOSER PROXIMITY TO BOUNDARY. WILL THEREFORE INCLUDE LOW CHANCE
POPS TODAY...WITH BEST RAIN CHANCES SOUTH OF I-72.
SHORT-WAVE TROUGH CURRENTLY EVIDENT ON WATER VAPOR IMAGERY OVER
SOUTHERN SASKATCHEWAN MAY PROVIDE A NEW WRINKLE IN THE FORECAST
FOR TUESDAY. WHILE WE PREVIOUSLY THOUGHT TUESDAY WOULD BE
DRY...LATEST MODEL GUIDANCE IS INDICATING THE POTENTIAL FOR
ISOLATED CONVECTION DURING THE AFTERNOON. THANKS TO A CONTINUED
MOIST AIR MASS AND THE ARRIVAL OF MODEST UPPER FORCING DURING PEAK
HEATING...HAVE INCLUDED A SLIGHT CHANCE FOR THUNDER TUESDAY
AFTERNOON. ONCE THE WAVE PUSHES FURTHER EAST...SURFACE HIGH
PRESSURE WILL BUILD INTO THE REGION FOR TUESDAY NIGHT AND
WEDNESDAY...PROVIDING SEASONABLY WARM AND DRY CONDITIONS.
LONG TERM...THURSDAY THROUGH SUNDAY
00Z 17 JUN MODELS CONTINUE TO SUGGEST A VERY WARM AND LARGELY DRY
EXTENDED FORECAST. ALL MODELS BUILD AN UPPER-LEVEL RIDGE ACROSS
THE PLAINS ON THURSDAY...THEN SHIFT IT INTO THE MIDWEST OVER THE
WEEKEND. PREVIOUS RUNS DISAGREED ON THE EXACT STRENGTH/POSITIONING
OF THE RIDGE...WHICH BROUGHT INTO QUESTION WHETHER ANY MCS
ACTIVITY COULD RIDE UP/OVER THE RIDGE INTO THE AREA DURING THE
PERIOD. LATEST GFS/ECMWF/GEM ARE ALL LOOKING STRONGER WITH THE
RIDGING...KEEPING BEST FORCING FOR NOCTURNAL MCS DEVELOPMENT
FURTHER NORTH ACROSS THE UPPER MIDWEST INTO THE GREAT LAKES. MODELS
INDICATE ONE CONVECTIVE COMPLEX MAY BRUSH THE KILX CWA TO THE
NORTH FRIDAY NIGHT...BEFORE RIDGE BUILDS EVEN FURTHER ON SATURDAY.
HAVE THEREFORE INCLUDED CHANCE POPS ALONG AND NORTH OF A CANTON TO
BLOOMINGTON LINE FRIDAY NIGHT...BUT HAVE GONE WITH A DRY FORECAST
ACROSS THE BOARD FOR THE REMAINDER OF THE EXTENDED. WILL LIKELY
HAVE TO WAIT UNTIL RIDGE BEGINS TO FLATTEN EARLY NEXT WEEK BEFORE
ANY WIDESPREAD RAIN CHANCES RETURN TO THE AREA. GIVEN BUILDING
UPPER HEIGHTS AND LACK OF CONVECTION...HIGH TEMPERATURES WILL
REACH THE UPPER 80S/LOWER 90S WHILE OVERNIGHT LOWS ONLY DROP INTO
THE LOWER 70S FRIDAY THROUGH SUNDAY.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
645 AM CDT MON JUN 17 2013
.DISCUSSION...
ISSUED 252 AM CDT MON JUN 17 2013
SHORT TERM...TODAY THROUGH WEDNESDAY
VERY WEAK SURFACE BOUNDARY EXTENDING ACROSS SOUTH-CENTRAL ILLINOIS
WILL BE THE PRIMARY FOCUSING MECHANISM FOR SCATTERED THUNDERSTORMS
TODAY. WITH ONE UPPER-WAVE PASSING WELL TO THE NORTH ACROSS THE
GREAT LAKES AND ANOTHER TRACKING TO THE S/SW INTO THE LOWER OHIO
RIVER VALLEY...VERY LITTLE UPPER SUPPORT WILL BE IN PLACE FOR
WIDESPREAD CONVECTION ACROSS CENTRAL ILLINOIS. DESPITE LACK OF
UPPER DYNAMICS...VERY MOIST AIRMASS IN PRESENCE OF WEAK SURFACE
FORCING WILL BE ENOUGH TO TRIGGER A FEW SHOWERS/THUNDERSTORMS
LATER TODAY. HRRR SUGGESTS DEVELOPMENT AROUND MIDDAY...ESPECIALLY
IN CLOSER PROXIMITY TO BOUNDARY. WILL THEREFORE INCLUDE LOW CHANCE
POPS TODAY...WITH BEST RAIN CHANCES SOUTH OF I-72.
SHORT-WAVE TROUGH CURRENTLY EVIDENT ON WATER VAPOR IMAGERY OVER
SOUTHERN SASKATCHEWAN MAY PROVIDE A NEW WRINKLE IN THE FORECAST
FOR TUESDAY. WHILE WE PREVIOUSLY THOUGHT TUESDAY WOULD BE
DRY...LATEST MODEL GUIDANCE IS INDICATING THE POTENTIAL FOR
ISOLATED CONVECTION DURING THE AFTERNOON. THANKS TO A CONTINUED
MOIST AIRMASS AND THE ARRIVAL OF MODEST UPPER FORCING DURING PEAK
HEATING...HAVE INCLUDED A SLIGHT CHANCE FOR THUNDER TUESDAY
AFTERNOON. ONCE THE WAVE PUSHES FURTHER EAST...SURFACE HIGH
PRESSURE WILL BUILD INTO THE REGION FOR TUESDAY NIGHT AND
WEDNESDAY...PROVIDING SEASONABLY WARM AND DRY CONDITIONS.
LONG TERM...THURSDAY THROUGH SUNDAY
00Z 17 JUN MODELS CONTINUE TO SUGGEST A VERY WARM AND LARGELY DRY
EXTENDED FORECAST. ALL MODELS BUILD AN UPPER-LEVEL RIDGE ACROSS
THE PLAINS ON THURSDAY...THEN SHIFT IT INTO THE MIDWEST OVER THE
WEEKEND. PREVIOUS RUNS DISAGREED ON THE EXACT STRENGTH/POSITIONING
OF THE RIDGE...WHICH BROUGHT INTO QUESTION WHETHER ANY MCS
ACTIVITY COULD RIDE UP/OVER THE RIDGE INTO THE AREA DURING THE
PERIOD. LATEST GFS/ECMWF/GEM ARE ALL LOOKING STRONGER WITH THE
RIDGING...KEEPING BEST FORCING FOR NOCTURNAL MCS DEVELOPMENT
FURTHER NORTH ACROSS THE UPPER MIDWEST INTO THE GREAT LAKES. MODELS
INDICATE ONE CONVECTIVE COMPLEX MAY BRUSH THE KILX CWA TO THE
NORTH FRIDAY NIGHT...BEFORE RIDGE BUILDS EVEN FURTHER ON SATURDAY.
HAVE THEREFORE INCLUDED CHANCE POPS ALONG AND NORTH OF A CANTON TO
BLOOMINGTON LINE FRIDAY NIGHT...BUT HAVE GONE WITH A DRY FORECAST
ACROSS THE BOARD FOR THE REMAINDER OF THE EXTENDED. WILL LIKELY
HAVE TO WAIT UNTIL RIDGE BEGINS TO FLATTEN EARLY NEXT WEEK BEFORE
ANY WIDESPREAD RAIN CHANCES RETURN TO THE AREA. GIVEN BUILDING
UPPER HEIGHTS AND LACK OF CONVECTION...HIGH TEMPERATURES WILL
REACH THE UPPER 80S/LOWER 90S WHILE OVERNIGHT LOWS ONLY DROP INTO
THE LOWER 70S FRIDAY THROUGH SUNDAY.
&&
.AVIATION...
ISSUED 645 AM CDT MON JUN 17 2013
AREAS OF FOG WITH IFR TO MVFR CONDITIONS AT PIA AND BMI...LOCALLY
DENSE ALONG I-72 AT SPI...DEC AND CMI WITH LIFR TO VLIFR
CONDITIONS...TO OCCUR UNTIL 13Z/8 AM WITH FOG LIFTING BEFORE
14Z/9 AM. SCATTERED CUMULUS CLOUDS OF 3-5K FT TO DEVELOP LATER
THIS MORNING AND AFTEROON WITH SCATTERED-BROKEN CIRRUS CLOUDS AT
25K FT. ISOLATED SHOWERS AND THUNDERSTORMS TO DEVELOP MAINLY SOUTH
OF I-72 THIS AFTERNOON NEAR A WEAK BOUNDARY AND BE CLOSEST IMPACT
TO SPI AND DEC AIRPORTS WHERE VCSH. SCATTERED CUMULUS CLOUDS
DISSIPATE AT SUNSET WITH SCATTERED CIRRUS CLOUDS. COULD BE PATCHY
FOG AGAIN OVERNIGHT WITH MVFR VSBYS POSSIBLE AFTER 07Z BUT NOT AS
WIDESPREAD AS EARLY THIS MORNING SINCE LARGER TEMPERATURE/DEWPOINT
SPREADS EXPECTED. WINDS TO REMAIN FAIRLY LIGHT UNDER 10 KTS NEXT
24 HOURS...WITH LIGHT AND VARIABLE TO CALM WINDS EARLY THIS
MORNING BECOMING WSW 5-7 KTS BY AFTERNOON AND DIMINISHING LIGHT
AGAIN AFTER SUNSET TONIGHT.
07
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CARIBOU ME
939 AM EDT MON JUN 17 2013
.SYNOPSIS...
LOW PRESSURE WILL CROSS THE REGION TODAY BRINGING A COLD FRONT
ACROSS THE AREA BY TONIGHT. A SECOND COLD FRONT IS EXPECTED TO
CROSS THE REGION ON TUESDAY WITH COOLER AIR TUESDAY NIGHT INTO
WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
938 AM UPDATE...LOW PRES IN SRN QUEBEC THIS MORNING IS 125 MILES
NW OF QUEBEC CITY AT 13Z WITH A WARM FRONT EXTENDING FROM THE LOW
AND ACROSS CENTRAL MAINE. THE LOW WILL MOVE EAST WITH THE FRONTAL
BOUNDARY TO SLOWLY LIFT NORTH TODAY AHEAD OF AN APPROACHING COLD
FRONT THAT IS EXPECTED TO MOVE INTO FAR NRN AND WRN MAINE TOWARD
EVENING. THE AIR MASS IN THE WARM SECTOR IS EXPECTED TO BECOME
MARGINALLY UNSTABLE THIS AFTERNOON ACROSS THE CENTRAL HIGHLANDS
AND INTERIOR DOWNEAST WITH SBCAPES OF 700-1200 J/KG. THERE WILL BE
SOME SHORTWAVES THAT GET EJECTED IN THE FLOW AROUND A DEEP UPPER
LOW JUST EAST OF JAMES BAY THAT WILL WORK ACROSS THE AREA. THERE
IS EXPECTED TO BE ENOUGH SHEAR BOTH SPEED AND DIRECTIONAL TO
ENHANCE THE UPDRAFT POTENTIAL AND CAUSE A FEW OF THE STORMS TO
BECOME STRONG/BORDERLINE SEVERE THIS AFTERNOON. THE BIGGEST THREAT
WILL LIKELY BE GUSTY WIND WITH THE POTENTIAL THAT ANY OF THE
STORMS THAT REALLY GET GOING COULD HAVE SOME LARGER HAIL. THE HRRR
HAD AN AREA OF SHOWERS MOVING INTO THE WESTERN MOUNTAINS THIS
MORNING THAT DID NOT MATERIALIZE TO THE EXTENT THE MODEL WAS
SHOWING. THE LATEST HRRR HAS THE MOST CONCENTRATED AREA OF SHOWERS
AND THUNDERSTORMS MID-LATE AFTERNOON INTO THIS EVENING...MAINLY
ACROSS NORTHERN MAINE AND INTERIOR DOWNEAST.
MADE SOME CHANGES TO THE HOURLY TEMPS THIS MORNING AS TEMPS ARE
NOT RISING MUCH IN THE NORTH WHERE THE STRATUS IS THICKER. TEMPS
WERE RAISED A COUPLE OF DEGREES IN THE SOUTH WHERE THERE IS MORE
SUNSHINE. THE HIGH TEMPS WERE RAISED A COUPLE OF DEGREES INTERIOR
DOWNEAST AND KEPT AS IS ACROSS THE NORTH WHERE THE LOW STRATUS
WILL BEGIN TO LIFT BY MIDDAY AND THERE IS STILL THE POTENTIAL THAT
THE MID SHIFTS HIGHS WILL REALIZED. OTHERWISE...JUST SOME MINOR
TWEAKS TO THE POP/SKY GRIDS FOR THE REMAINDER OF THE MORNING.
PREVIOUS DISCUSSION...
PROBLEM OF THE DAY WILL BE POTENTIAL FOR CONVECTION.
630 AM UPDATE:
AREAS OF DENSE FOG SEEN ALONG THE COAST THIS MORNING PER THE BAR
HARBOR METARS AND THIS IS SUPPORTED BY SOME WEBCAMS IN THAT AREA.
LATEST LAPS SOUNDING SHOWED MOISTURE TRAPPED BELOW 950 MBS. PATCHY
FOG THROUGHOUT THE CWA MAINLY IN THE RIVER VALLEYS. THE FOG WILL
BURN OFF AFTER 8AM. LATEST RADAR SHOWED SHOWERS NOW MOVING INTO
NEW BRUNSWICK W/SOME PATCHY DRIZZLE IN SOME LOCALES ACROSS
NORTHERN MAINE THIS MORNING. SHOWERS MOVING INTO WESTERN MAINE
MTNS THIS MORNING WILL MOVE ACROSS THE CENTRAL HIGHLANDS LATER
THIS MORNING. THEREFORE, BACKED DOWN THE PRECIP CHANCES TO
ACROSS THE NORTH AND CARRIED A MENTION OF SCATTERED SHOWERS THIS
MORNING DOWN ACROSS THE CENTRAL HIGHLANDS.
PREVIOUS DISCUSSION...
THINGS ARE EXPECTED TO CHANGE BY EARLY AFTERNOON AS THE FRONTAL
BOUNDARY LIFTS NORTH AND THE CWA GETS INTO A PSEUDO WARM SECTOR
AHEAD OF THE APCHG COLD FRONT. THIS WILL ALLOW FOR DESTABILIZATION
W/SOME SUNSHINE EXPECTED W/TEMPERATURES HITTING UPPER 60S TO LOWER
70S. LLVLS WILL WARM AHEAD OF A PRE-FRONTAL BOUNDARY AID IN LLVL
INSTABILITY. ALOFT, THE AIRMASS WILL BE COLD ENOUGH W/MID LEVEL
TEMPERATURES(700/500MBS) RUNNING -2C/-19C RESPECTIVELY. MDL
SOUNDINGS FROM THE NAM AND GFS SUPPORT POSSIBLE TSTMS EARLY THIS
AFTERNOON ACROSS THE NORTH AND WESTERN AREAS W/SB CAPES OF
600-900J/KG W/THE GFS THE MOST AGGRESSIVE. 0-6KM BULK SHEAR IS
FCST TO BE AROUND 35 KTS. 700-500MB LAPSE RATES FCST TO BE 6.0-6.5
ACROSS THE NORTHERN 1/2 EARLY THIS AFTERNOON AND CLOSE TO 7.0 C/KM
ACROSS THE INTERIOR DOWNEAST BY MID/LATE AFTERNOON. ENOUGH LLVL
MOISTURE IN PLACE W/SOME DRYING IN THE MID LEVELS WILL ADD TO THE
MIX. THEREFORE, DECIDED TO ADD THE MENTION OF SMALL HAIL AND GUSTY
WINDS IN FOR TSTMS ACROSS THE AFOREMENTIONED AREAS. THE ACTION
WILL SHIFT TO THE CENTRAL AND INTERIOR DOWNEAST AREAS THIS
AFTERNOON AND CONTINUE INTO EARLY EVENING AS TEMPERATURES ARE FCST
TO WARM WELL INTO THE 70S AND DEWPOINTS CLIMB TO AROUND 60F. SW
WIND SHIFTING TO THE WEST THIS AFTERNOON WILL ERODE OUT THE STABLE
MARINE LAYER ALLOWING FOR FURTHER DESTABILIZATION. DECIDED TO
CARRY ENHANCED WORDING W/THE TSTMS INCLUDING THE BANGOR AND CALAIS
AREAS AND KEPT THE MENTION OF THUNDER OUT OF THE COAST DUE TO A
SOUTH FLOW HOLDING ON LONGER. QPF WILL BE A CHALLENGE DUE TO THE
EXPECTED CONVECTION. DECIDED ON A BLEND OF THE GEM/NAM12 AND GFS
AND MANUALLY ADJUSTED TO ACCOUNT TO 2 AREAS OF HEAVIER
AMOUNTS(0.25") W/ONE AREA ACROSS THE NORTH AND THE 2ND AREA OVER
THE DOWNEAST REGION.
THINGS WILL WIND DOWN TONIGHT AS THE COLD FRONT CROSSES THE REGION
AS LOW PRES MOVES ACROSS SOUTHERN CANADA. SOME PARTIAL CLEARING IS
EXPECTED AND THIS WILL LEAD TO SOME FOG. ATTM, DECIDED TO STAY W/PATCHY
FOG. THE DAYCREW CAN ASSESS THIS FURTHER W/THE LATER MODEL RUNS. FOLLOWED
THE GEM AND NAM12 FOR TEMPERATURES/DEWPOINTS FOR TONIGHT.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
HIGH PRESSURE IS EXPECTED TO BUILD IN AT THE SURFACE AT THE
BEGINNING OF THIS PERIOD. AT THE SAME TIME AN UPPER LEVEL TROUGH
WILL APPROACH FROM THE WEST AND MOVE ACROSS THE REGION
WEDNESDAY...HOWEVER WITH DRY CONDITIONS WILL KEEP POPS LOW. HAVE
BLENDED THE GFS...SREF...NAM AND ECMWF FOR POP AND QPF GRIDS. WILL
USE A BLEND OF NAM12 AND GMOS FOR WINDS. FOR TEMPERATURE GRIDS WILL
INITIALIZE WITH GMOS AND WILL RAISE MINIMUM TEMPERATURE TWO
DEGREES BASED ON VERIFICATION. HAVE USED THE GEM FOR DEW POINT
GRIDS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
HIGH PRESSURE WILL CONTINUE TO BUILD IN FROM THE WEST AT THE
BEGINNING OF THIS PERIOD THEN CREST OVER THE REGION THURSDAY
MORNING. A COLD FRONT WILL APPROACH FROM THE NORTHWEST THURSDAY
NIGHT AND CROSS THE STATE FRIDAY. A FRONTAL SYSTEM WILL REMAIN
NEAR THE NORTHERN PORTION OF THE STATE LATE SATURDAY THROUGH
TUESDAY. HAVE USED THE GMOS TO INITIALIZE ALL GRIDS. WILL ADJUST
POP AND SKY GRIDS. HAVE ALSO ADJUSTED ALL MINIMUM TEMPERATURES
HIGHER AND TO BETTER FIT THREE HOUR GMOS.
&&
.AVIATION /13Z MONDAY THROUGH FRIDAY/...
NEAR TERM: IFR AT THE NORTHERN TERMNINALS WILL IMPRVE TO VFR BY
LATE MORNING TO MIDDAY WITH VFR AT KBGR AND KBHB. TSTMS ARE
POSSIBLE THIS AFTERNOON INTO EARLY EVENING AFFECTING THE
TERMINALS. STRONG AND ERRATIC WIND GUSTS AND SMALL WILL BE A
CONCERN.
SHORT TERM: EXPECT VFR CONDITIONS TUESDAY THROUGH FRIDAY.
&&
.MARINE...
NEAR TERM: WAVE HEIGHTS ARE RUNNING AROUND 3 FEET AT THE EASTERN
MAINE SHELF THIS MORNING AND SHOULD BUILD TO 4 TO 5 FT BY THIS
EVENING AS A SOUTHERLY FETCH SETS W/A SWELL COMPONENT. WINDS WILL
BE LIGHT AVERAGING SPEEDS OF 10 KTS.
SHORT TERM: FOR WINDS HAVE BLENDED THE NAM12 AND GFS40 AND WILL
USE 125 PERCENT OF THE MODEL BLEND FOR GUST SPEED. FOR WAVES:
EXPECT WINDS ACROSS LOCAL WATERS TO BE LIGHT THROUGH THIS PERIOD
SO LONG PERIOD WAVE WILL DOMINATE. EXPECT SOUTHERLY WAVE GROUP
2-3 FEET/8 SECONDS ACCOMPANIED BY SECONDARY SOUTHEAST GROUP 1-2
FEET/10 SECONDS.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...CB/HEWITT
SHORT TERM...MIGNONE
LONG TERM...MIGNONE
AVIATION...CB/HEWITT/MIGNONE
MARINE...CB/HEWITT/MIGNONE
AREA FORECAST DISCUSSION
NWS JACKSON MS
1056 AM CDT MON JUN 17 2013
.UPDATE...
OVERALL..,ONLY MINOR ADJUSTMENTS WERE MADE IN THIS FORECAST UPDATE.
THERE ARE TWO AREAS OF FOCUS FOR CONVECTIVE DEVELOPMENT THIS
AFTERNOON. A COMPLEX OF STORMS THAT DEVELOPED EARLY THIS MORNING
OVER NORTH CENTRAL MS HAS STABILIZED AREAS ALONG THE HIGHWAY 82
CORRIDOR. THE LATEST HRRR SUGGESTS THAT FUTURE CONVECTION WILL
DEVELOP ALONG THE DIFFERENTIAL HEATING/OUTFLOW BOUNDARY LEFT FROM
THIS COMPLEX OVER AREAS NORTH OF I-20.
THE OTHER FEATURE OF CONCERN IS THE DECAYING UPSTREAM CONVECTIVE
COMPLEX CURRENTLY CROSSING THE ARKLATEX. HIGH RES GUIDANCE SUGGEST
FURTHER DECAY OF COMPLEX WITH A RESIDUAL BOUNDARY HELPING TO INITIATE
STORMS LATER THIS AFTERNOON INTO THE EVENING. LIMITING FACTORS
HOWEVER IN ENVIRONMENT AHEAD OF THE COMPLEX ARE THE NEGATIVE LOW-LEVEL
THETAE ADVECTION INTO SOUTHERN PORTIONS OF THE ARKLAMISS...AND
RELATIVE WESTERLY FLOW AHEAD OF THE BOUNDARY THAT IS LIMITING LOW
LEVEL CONVERGENCE. WITH THIS IN MIND...STILL EXPECT GREATEST
AFTERNOON CONVECTIVE POTENTIAL FOR AREAS ALONG AND NORTH OF THE I-20
CORRIDOR AND THE GOING FORECAST HAS A GOOD HANDLE ON THE SCENARIO.
THE UPDATED AVIATION DISCUSSION IS BELOW. /EC/
&&
.PREV DISCUSSION... /ISSUED 326 AM CDT MON JUN 17 2013/
SHORT TERM...CHALLENGING CONVECTIVE FORECAST TODAY AS TIMING
SPECIFICS ARE VERY DIFFICULT DUE TO POOR REPRESENTATION OF THE
CURRENT S/WV`S AND MCV FEATURES IN THE MODEL DATA. STILL...THE
PATTERN WILL SUPPORT MULTIPLE S/WV FEATURES THROUGH TUE NIGHT AND
BRING SEVERAL OPPORTUNITIES FOR SHRA/TSRA DURING THE NEXT 48 HRS.
YESTERDAY OFFERED GREATER STORM/PRECIP COVERAGE THAN EXPECTED AND
WAS LIKELY THE KICKOFF DAY FOR THIS UPCOMING WETTER PERIOD.
ATMOSPHERIC MOISTURE SHOWED A MARKED INCREASE FROM SUNDAY MORNING TO
THE AFTERNOON AS PWS REACHED 2 IN. LOOK FOR THIS MORE MOIST AIRMASS
TO HANG AROUND WITH PWS RANGING FROM 1.75-2.0 INCHES. THIS WILL
COMBINE WITH MULTIPLE DISTURBANCES TRAVERSING THE REGION TO
INSTIGATE NUMEROUS SHOWERS AND STORMS. THE FIRST MCV JUST PUSHED
INTO AL AND WAS GENERATED BY THE AFTERNOON STORMS OVER THE WESTERN
PART OF THE CWA. EARLY THIS MORNING...A MCV IS PUSHING EAST ACROSS
CENTRAL AR AND WILL LIKELY AID IN PRECIP ACTIVITY THIS
MORNING/AFTERNOON. THERE IS ALSO A MUCH LARGER DISTURBANCE PUSHING
ACROSS OK AND THIS WILL TOO HELP SUPPORT CONVECTION LATER IN THE
AFTERNOON/EVE ESPECIALLY ACROSS THE W/NW AREAS. IF THAT WASN`T
ENOUGH...ADDITIONAL DISTURBANCES ARE PROGGED TO CONTINUE IN THE
PERTURBED FLOW AND SUPPORT ADDITIONAL CONVECTION THROUGH TUE. AT
THIS TIME...WILL CONTINUE TO BE GENERAL WITH TIMING DUE TO THE
UNCERTAINTY WITH HOW EACH FEATURE WILL EVOLVE AND FOLLOW CLOSE TO
THE HIGHER GUIDANCE POPS. FOR TODAY...I CURRENTLY HAVE THE BEST
PRECIP CHANCES FOR THE AFTERNOON...BUT THIS MAY HAVE TO BE REVISITED
BASED ON HOW STORM TRENDS THIS MORNING GO.
TODAY SEEMS TO HAVE A POTENTIAL FOR STRONG STORMS ALONG WITH A FEW
SEVERE STORMS MIXED IN. THE REASON IS THAT SOME WARMER SFC TEMPS MAY
BE REALIZED AS HIGHS PEAK AROUND 90 WHICH COULD RESULT IN NEAR 3000
J/KG OF SBCAPE. THERE WILL ALSO BE SOME COOLER MID LEVEL TEMPS ALONG
WITH SOME STRONGER FLOW (25-30KTS) AT 500MB WHICH SHOULD HELP
SUPPORT A FEW VIGOROUS UPDRAFTS. DUE TO THIS...WILL MENTION THIS
POTENTIAL IN THE HWO/GRAPHICS. THE MAIN THREAT WILL BE FROM GUSTY
WINDS 50-60 MPH AND SMALL HAIL. YESTERDAY...LIGHTNING WAS ALSO
FREQUENT WITH THE STRONGER STORMS AND THAT MAY AGAIN BE THE CASE.
/CME/
LONG TERM...WEDNESDAY THROUGH NEXT MONDAY...A RATHER ACTIVE
PATTERN CONTINUES ACROSS THE FORECAST AREA AS NORTHWEST FLOW
PERSISTS INTO AT LEAST THURSDAY...WHILE SUBTLE UPPER LEVEL
DISTURBANCES IMPEDE UPON THE CWA ALONG A QUASI-STATIONARY SURFACE
BOUNDARY. AN UPPER RIDGE WILL BUILD EAST INTO THE FORECAST AREA
FRIDAY INTO THE WEEKEND. CHANCES FOR MAINLY AFTERNOON AND EARLY
EVENING SHOWERS AND STORMS WILL REMAIN OVER PARTS OF THE FORECAST
AREA DURING THIS TIME AND INTO NEXT MONDAY. CONVECTION FRIDAY
THROUGH MONDAY IS EXPECTED TO BE MORE DIURNALLY DRIVEN AND ISOLATED
TO SCATTERED IN NATURE COMPARED TO THE MORE ORGANIZED CONVECTION
SEEN EARLIER IN THE WORK WEEK.
OTHERWISE...WARM AND VERY HUMID CONDITIONS WILL PERSIST THROUGH THE
ENTIRE PERIOD. HIGHS EACH AFTERNOON WILL RANGE IN THE LOW TO MIDDLE
90S. GUIDANCE SUGGESTED AS THE RIDGE BUILT IN FRIDAY...HIGHS COULD
RANGE FROM 95-97. GIVEN EXPECTED WET GROUND CONDITIONS DURING THIS
TIME...FELT THESE WERE TOO HIGH. THEREFORE I KNOCKED OFF 2-3
DEGREES AND NOW HAVE HIGHS RANGING FROM 92-94 ON FRIDAY. ELSEWHERE
THROUGH THE PERIOD...BOTH GUIDANCE HIGH AND LOW TEMPERATURES LOOKED
REASONABLE. /19/
&&
.AVIATION...CONDITIONS WILL GENERALLY BE VFR VFR TODAY...THE
EXCEPTION BEING MVFR CIGS/VSBYS...LCLY IFR VSBYS...WHERE SHWRS/TSTMS
OCCUR. AN AREA OF LATE MORNING SHWRS/TSTMS EXISTS OVER NRN/NERN
ZONES DURING THE LATE MORNING/EARLY AFTERNOON. THE FOCUS WILL SHIFT
TO SCT SHWRS/TSTMS FOR THE REMAINDER OF THE REGION DURING THE
AFTERNOON. FOR TONIGHT...THERE LOOKS TO BE SOME LINGERING STORM
CHANCES OVERNIGHT AND SOME RISK FOR SOME MVFR CONDITIONS FOR THE
AREAS THAT RECEIVED PRECIP. /CME/03
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 92 71 89 70 / 36 42 49 50
MERIDIAN 91 70 89 69 / 49 47 57 57
VICKSBURG 92 72 89 70 / 29 45 50 47
HATTIESBURG 92 72 91 72 / 36 23 36 31
NATCHEZ 90 71 89 70 / 26 25 37 32
GREENVILLE 91 73 87 70 / 51 67 66 40
GREENWOOD 90 71 88 69 / 54 66 68 41
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
945 AM EDT MON JUN 17 2013
.SYNOPSIS...
THE THREAT FOR SHOWERS AND THUNDERSTORMS REMAINS UNTIL A COLD
FRONT ACROSS THE UPPER LAKES SINKS SOUTHWARD ACROSS NW PA AND NRN
OH TUESDAY. HIGH PRESSURE WILL TAKE ITS PLACE ACROSS THE GREAT
LAKES FOR THE REMAINDER OF THE WORK WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HAVE MADE JUST MINOR CHANGES TO THE FORECAST...MAINLY TO CLOUDS.
TEMPS SEEM ON TRACK. LATEST GUIDANCE INCLUDING HRRR CONTINUES TO
SHOW SHOWERS AND STORMS FIRING OVER LAKE ERIE LATE TODAY AND THEN
MOVING INLAND. WILL CONTINUE TO MONITOR.
PREVIOUS...STARTING TO GET SOME PATCHY FOG REPORTED IN THE OBS...MOST
NOTABLY WHERE THE MOST RAIN FELL YESTERDAY. HAVE ADDED A COUPLE OF
HOURS OF PATCHY FOR TO THE FORECAST GRIDS SINCE SOME OF THE
VISIBILITIES ARE BELOW A HALF MIL. AREA STABILIZED EARLY THIS
MORNING AND WITH NOTHING TO INITIATE A SHOWER/TS...MUCH OF THE
FIRST PART OF THE DAY IS EXPECTED TO REMAIN DRY. A FRONTAL
BOUNDARY STILL LINGERS JUST NORTH OF THE OHIO BORDER...DIVIDING
MID AND UPPER 60 DEWPOINTS TO ITS SOUTH FROM MID 50S DEWPOINTS TO
ITS NORTH...BUT IT IS MUCH LESS DEFINED THAN YESTERDAY. 00Z DTX
SOUNDING ALSO SHOWS THE RELATIVE DRYING THAT HAS TAKEN PLACE.
SHOULD NOT HAVE TO WORRY ABOUT SHRA/TS FOR A GOOD PART OF TODAY.
WILL BRING LOW PRECIP CHANCES INTO ERIE PA AFTER 2 PM AND INTO CLE
AFTER 5P AS INSTABILITY INCREASES AND FRONTAL ZONE ACROSS MI INTO
ONTARIO BEGINS TO DEVELOP SCATTERED CONVECTION. WITH THE GENERAL
WESTERLY FLOW...H8 TEMPS CREEP UP A COUPLE OF DEGREES FOR TODAY.
SO WILL TACK ON SOME FOR THE HIGHS. THIS WILL PUT NW OHIO SOLIDLY
INTO THE MID 80S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
UPPER TROUGH SHARPENS AND FRONTAL BOUNDARY WILL FINALLY START TO
SINK SOUTHWARD. SCATTERED CONVECTION EXPECTED ACROSS MI/ONTARIO
FOR THE LATE AFTERNOON AND THAT WILL BEGIN TO SEEP INTO NW PA/NRN
OHIO DURING THE EARLY EVENING. WILL MAXIMIZE PRECIP CHANCES THEN
IN THE EVENING...TAPERING THEM OVERNIGHT AS WE STABILIZE. FRONT
THOUGH WILL BE SLOW TO FLUSH THROUGH THE AREA AND WILL KEEP SOME
PRECIP CHANCES INLAND FOR TUESDAY. MILD AGAIN TONIGHT WITH 60S FOR
LOWS. TUESDAYS TEMPS WILL REMAIN MILD ACROSS THE SOUTH...BUT THE
EFFECTS OF COOLER AND DRIER HIGH PRESSURE ACROSS THE CENTRAL GREAT
LAKES WILL BEGIN TO OVERSPREAD THE LAKESHORE.
GOOD MODEL CONSENSUS FOR A DRY PERIOD WITH HIGH PRESSURE DOMINANT
FOR TUESDAY NIGHT THROUGH THURSDAY NIGHT. HIGHS WILL SLIP BACK
SLIGHTLY BELOW NORMAL AND NIGHTS AGAIN WILL GET INTO THE LOWER
50S...WITH A FEW UPPER 40S POSSIBLE. AMPLE SUN AND CLEARING
THROUGH THE PERIOD.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
GFS AND ECMWF SHOWING A DEVELOPING UPPER RIDGE ACROSS THE SOUTH
CENTRAL AND SOUTHEASTERN STATES INTO THE OHIO VALLEY LATE WEEK AND
INTO THE WEEKEND WHICH MEANS ON BALANCE...A BIT MORE HEAT IN THE
REGION. FRIDAY MODELS SHOW A SURFACE HIGH ACROSS THE GREAT LAKES AND
OHIO VALLEY WITH LOW PRESSURE IN KS/NE. GIVEN THE SURFACE HIGH IN
THE REGION WENT WITH A DRY FORECAST FOR THE DAY. HUMIDITY WILL BE
INCREASING SATURDAY INTO SUNDAY AS THE BOTH THE HIGH AND LOW DRIFT
EAST SETTING UP A SOUTHERLY CONVEYOR OUT OF THE GLFMX. SUNDAY THE
LOW WILL BE IN THE AREA WITH A WARM FRONT TO OUR EAST AND A TRAILING
COLD FRONT WEST. EXPECTING A DECENT SHOT OF AFTERNOON/EVENING
SHOWERS/THUNDERSTORMS SATURDAY AND SUNDAY ALTHOUGH WITH THE UPPER
HIGH ALSO NOSING INTO THE AREA WILL HOLD POPS TO THE CHANCE
CATEGORY. EXPECT HIGHS FROM THE LOW TO MID 80S.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
EARLY MORNING FOG/MIST ACROSS THE AREA WITH MOST LOCATIONS MVFR
ALTHOUGH LIFR AT KCAK AND KYNG. FOG/MIST SHOULD BURN OFF QUICKLY
THIS MORNING BUT AT LEAST MVFR RESTRICTIONS WILL LIKELY LAST THRU
14Z AT KYNG AND KCAK. FOR THE REMAINDER OF THE DAY EXPECTING VFR
CONDITIONS WITH MAINLY SCATTERED CLOUDS BETWEEN 4 AND 6 THOUSAND
FEET ALTHOUGH LOCAL CUMULUS SCHEME SUGGESTS A FEW HOURS OF BKN
ACROSS THE EAST HALF OF THE AREA. AFTER 00Z EXPECTING INCREASING
CLOUDS FROM 10K AND BELOW AS NEXT COLD FRONT APPROACHES FROM THE
NORTH. BOUGHT VCSH TO MUCH OF AREA AFTER 04Z ALTHOUGH AN ISOLATED
SHOWER NOT OUT OF THE QUESTION EAST HALF BY LATE AFTERNOON.
.OUTLOOK...MAINLY VFR EXCEPT FOR EARLY MORNING MIST/FOG.
&&
.MARINE...
WEAK STATIONARY FRONT ALONG THE SOUTH SHORE OF LAKE ERIE EARLY TODAY
WILL BEGIN TO DRIFT SOUTH THROUGH THE MORNING AS ANOTHER COLD FRONT
DROPS ACROSS THE CENTRAL LAKES TOWARD THE AREA. THIS SECOND FRONT
WILL MOVE ACROSS THE LAKE THIS EVENING. HIGH PRESSURE WILL
FOLLOW...BUILDING ACROSS THE CENTRAL GREAT LAKES TUESDAY THROUGH
THURSDAY. THE HIGH WILL DRIFT TO NEW ENGLAND ON FRIDAY. EXPECTING
SOUTHWEST WINDS ON THE LAKE TODAY AHEAD OF THE COLD FRONT. WINDS
WILL TURN NORTH TONIGHT AND THEN NORTHEAST FOR TUESDAY. WITH THE
HIGH TO OUR NORTH...WINDS WILL REMAIN FROM THE NORTHEAST FROM
TUESDAY THROUGH WEDNESDAY NIGHT OR THURSDAY BEFORE SHIFTING EAST TO
SOUTHEAST FRIDAY. NOT EXPECTING WINDS OR WAVES TO GET HIGH ENOUGH
FOR A SMALL CRAFT ADVISORY THROUGH THE PERIOD HOWEVER THE
NORTHEAST FLOW WILL MAKE A 2 TO 3 FOOT CHOP ON THE CENTRAL AND
WEST THIRD NEARSHORE WATERS MIDWEEK.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...OUDEMAN
NEAR TERM...KUBINA/OUDEMAN
SHORT TERM...OUDEMAN
LONG TERM...TK
AVIATION...TK
MARINE...TK
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
930 AM CDT MON JUN 17 2013
.UPDATE...
A COMPLEX OF THUNDERSTORMS CONTINUES TO WEAKEN AS IT PROGRESSES
THROUGH ROUGHLY THE EASTERN HALF OF THE CWA. GUSTY WINDS TO 30-40
MPH MAY STILL OCCUR ALONG THE LEADING EDGE BUT OTHERWISE BRIEF
HEAVY RAINFALL AND LIGHTNING STRIKES WILL BE THE MAIN THREATS.
HAVE UPDATED THE FORECAST TO REFLECT THE LATEST RADAR...TEMP...SKY
TRENDS FOR THE NEXT FEW HOURS. ALSO DECREASED AFTERNOON
TEMPERATURES A FEW DEGREES FOR NOW AND WILL LOOK AT TEMPS AGAIN
THROUGH THE MORNING HOURS.
WE ARE STILL WORKING TO EVALUATE PRECIPITATION CHANCES AND TRENDS
FOR THE REMAINDER OF THE DAY AND TONIGHT. THERE IS ALREADY
DISCREPANCIES AMONG THE MODELS ON PRECIP EVOLUTION LATER TODAY AND
NOW THE COMPLEX OF THUNDERSTORMS THIS MORNING WILL LIKELY ALSO
EFFECT TRENDS. WILL LIKELY BE ISSUING ANOTHER UPDATE BY MIDDAY
AFTER TAKING A CLOSER LOOK AND EVALUATING THE 12Z/LATEST MODEL
DATA.
82/JLD
&&
.PREV DISCUSSION... /ISSUED 353 AM CDT MON JUN 17 2013/
A LARGE MCS WILL CONTINUE MOVING SOUTHEAST TOWARD NORTH TEXAS
EARLY THIS MORNING AND SHOULD REACH THE NORTHWEST ZONES SHORTLY
BEFORE 6 AM AS PER THE HRRR AND 4KM WRF SOLUTIONS AS WELL AS LINEAR
EXTRAPOLATION. THE COMPLEX SHOULD WEAKEN AS IT MOVES FARTHER AWAY
FROM ITS UPPER SUPPORT AND ALSO ONCE A 30 KNOT LOW LEVEL JET
DECREASES LATER THIS MORNING. THIS SOLUTION IS ALSO SUPPORTED BY
THE HRRR AND 4KM WRF. WE STILL EXPECT EXTENSIVE CLOUD COVER AND
SCATTERED TO NUMEROUS STORMS...THROUGH THE MORNING WITH THE
EXPECTED TIME OF ARRIVAL OF STORMS AT THE METROPLEX BETWEEN 13 AND
15Z. SOME IMPRESSIVE WIND GUSTS BETWEEN 50 AND 55 KNOTS ARE
OCCURRING WITH THE COMPLEX. IT IS VERY POSSIBLE THAT SOME SIMILAR
WIND GUSTS COULD OCCUR ACROSS THE NORTHWEST CWA BY 6 AM. EXPECT
STORMS TO BECOME LESS ORGANIZED BY MIDDAY AND AFFECT MAINLY THE
EAST/NORTHEAST ZONES.
MODELS ARE CONSISTENT ON DEVELOPING MORE STORMS ACROSS WEST TEXAS ALONG
A FAST MOVING SHORT WAVE AND COLD FRONT LATE THIS AFTERNOON. AM A
BIT CONCERNED THAT EXTENSIVE OVERNIGHT/MORNING CONVECTION MAY
HINDER STORM DEVELOPMENT THIS AFTERNOON. HOWEVER...THE ATMOSPHERE
MAY HAVE JUST ENOUGH TIME TO RECOVER BEFORE SURFACE HEATING IS
LOST. STORMS SHOULD ORGANIZE ALONG THE COLD FRONT AND MOVE
SOUTHEAST INTO NORTH TEXAS TONIGHT/TUESDAY MORNING. AGAIN...WILL
KEEP THE HIGHEST POPS ACROSS THE NORTHERN ZONES. THE COLD FRONT IS
PROGGED TO STALL ACROSS THE NORTHERN HALF OF THE REGION TUESDAY
NIGHT AND LIFT NORTH OF THE RED RIVER BY WEDNESDAY EVENING.
AFTER WEDNESDAY...UPPER LEVEL HIGH PRESSURE WILL BUILD FROM
TEXAS...NORTHWARD THROUGH THE CENTRAL PLAINS. THIS PATTERN WILL
RESULT IN HOT TEMPERATURES AND LITTLE RAIN CHANCES WEDNESDAY NIGHT
THROUGH EARLY NEXT WEEK. EXPECT AFTERNOON HIGHS THROUGH EARLY NEXT
WEEK MAINLY IN THE LOWER AND MIDDLE 90S...EXPERT FOR SOME UPPER
90S IN THE WEST. OVERNIGHT LOWS WILL BE IN THE 70S THROUGH EARLY
NEXT WEEK.
79
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 93 77 92 75 95 / 100 30 30 20 20
WACO, TX 91 75 93 74 94 / 40 20 20 20 10
PARIS, TX 89 73 87 72 88 / 100 30 40 40 40
DENTON, TX 91 75 92 73 94 / 100 30 40 30 20
MCKINNEY, TX 90 73 90 73 92 / 100 30 40 30 20
DALLAS, TX 92 77 92 76 93 / 100 30 30 20 20
TERRELL, TX 91 75 91 73 92 / 100 20 30 20 20
CORSICANA, TX 91 74 91 74 92 / 100 20 20 20 10
TEMPLE, TX 91 72 92 73 92 / 20 20 20 10 10
MINERAL WELLS, TX 92 72 92 71 95 / 30 30 30 20 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
05/82
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
637 AM CDT MON JUN 17 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 307 AM CDT MON JUN 17 2013
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED AN UPPER LOW OFF THE PACIFIC NORTHWEST COAST...RIDGING
BUILDING FROM NEW MEXICO INTO BRITISH COLUMBIA...AND TROUGHING OVER
SOUTHEAST CANADA INTO THE EASTERN GREAT LAKES. WITHIN THE
WEST-NORTHWEST FLOW...TWO SHORTWAVES OF NOTE WERE NEAR FARGO NORTH
DAKOTA AND IN FAR SOUTHWEST SASKATCHEWAN. 700-850MB MOISTURE
TRANSPORT AHEAD OF THE FARGO SHORTWAVE HELPING TO SUPPORT SOME HIGH
BASED SHOWERS ALONG/NORTHEAST OF I-94. TALKING ABOUT HIGH BASED...
00Z MPX AND GRB SOUNDINGS BOTH DEPICTED MIXING UP TO 750MB...WITH
DEEP INVERTED-V APPEARANCE BELOW. THIS DEEP MIXING ALLOWED FOR
SHOWERS THAT MOVED THROUGH MPX AROUND RAOB RELEASE TIME TO PRODUCE
WIND GUSTS OF 30-50KT. THESE SHOWERS WERE MORE VIGOROUS THEN THOSE
OCCURRING NOW...PLUS THEY OCCURRED RIGHT AFTER PEAK HEATING WHEN
MIXING WAS AT ITS MAXIMUM...ALLOWING FOR THE STRONG GUST POTENTIAL.
OTHERWISE...SKIES ARE MOSTLY CLEAR OVER THE FORECAST AREA SOUTH OF A
COLD FRONT EXTENDING FROM NORTHERN MN INTO NORTHERN LOWER MI. 850MB
TEMPS AT 00Z AHEAD OF THE FRONT WERE 14-16C AT MPX...GRB AND
DVN...COMPARED TO 4C BEHIND THE FRONT UP AT PICKLE LAKE IN NORTHWEST
ONTARIO. ALTHOUGH DEEP MIXING EXISTED ON THAT MPX SOUNDING...THE
HIGHER MID LEVEL MOISTURE ALLOWED FOR THE PRECIPITABLE WATER TO JUMP
UP TO 0.93 INCHES AS OF 00Z...COMPARED TO 0.44 12 HOURS EARLIER.
THUS...THERE IS SOME MOISTURE AHEAD OF THE FARGO SHORTWAVE.
MODEL TRENDS FOR TODAY HAVE REALLY SHIFTED THE SHORTWAVE COMING INTO
THE FORECAST AREA NORTH COMPARED TO THE 16.00Z CYCLE. MODEL
CONSENSUS NOW SUGGESTS THAT THE SHORTWAVE NEAR FARGO ENDS UP
CROSSING CLARK COUNTY AT 00Z TUESDAY...COMPARED TO SAY LA CROSSE.
THIS HAS A BIG IMPACT ON PLACEMENT OF PRECIPITATION CHANCES.
WITH THE SHORTWAVE TRACKING FARTHER NORTH TODAY...THE COLD FRONT
ONLY DROPS SOUTH TO MAYBE THE I-94 CORRIDOR BY 00Z. COMBINATION OF
LOW LEVEL CONVERGENCE ON THE FRONT...LOW TO MID LEVEL FRONTOGENESIS
NORTH OF THE FRONT...THE APPROACH OF THE SHORTWAVE TO YIELD SOME
DPVA AND DAYTIME HEATING SHOULD PROVE FAVORABLE FOR NUMEROUS SHOWERS
ALONG/NORTH OF I-94. COULD EVEN SEE SOME ISOLATED/SCATTERED ACTIVITY
SOUTH OF THERE TOWARDS I-90 VERY LATE IN THE DAY AS THE FRONTAL
FORCING APPROACHES. DEEP MIXING AGAIN LOOKS LIKELY TODAY AHEAD OF
THE APPROACHING FRONT. NAM/RAP SOUNDINGS SHOW POTENTIAL OF 7500-9500
FT AGL FROM CLARK COUNTY SOUTHWARD...WHICH RESULTS IN HIGHS IN THE
LOW TO PERHAPS EVEN SOME MID 80S. THIS SHOULD ALLOW DEWPOINTS TO
FALL INTO THE LOW TO MID 50S. COMBINATION OF THE TWO RESULTS IN
0-1KM MLCAPES OF 400-700 J/KG IN THE AREA ALONG/NORTH OF THE FRONT.
ALTHOUGH THIS IS NOT MUCH...IT WILL BE ENOUGH TO BOTH ADD
THUNDERSTORMS AND MAKE THE SHOWERS MORE VIGOROUS. FREEZING LEVELS
ARE LOW...9500-1000 FT AGL AT 21Z WHICH COULD ALLOW FOR SOME
HAIL...BUT THE MINIMAL CAPE WHICH IS TALL AND SKINNY MAY KEEP ANY
HAIL SMALL. BIGGER CONCERN WILL LIKELY BE WIND GIVEN THE DEEP MIXING
YIELDING DEEP INVERTED-V LOOKS ON A SKEW-T. COULD SEE STRONG TO
SEVERE WIND GUSTS...JUST LIKE WHAT WENT THROUGH MINNEAPOLIS AROUND
00Z LAST EVENING.
THE VIGOROUS CONVECTIVE ACTIVITY WILL LIKELY DIMINISH QUICKLY AFTER
00Z AS LOSS OF HEATING KNOCKS DOWN CAPE. HOWEVER...
ISOLATED/SCATTERED SHOWER ACTIVITY MAY PERSIST THROUGH MUCH OF THE
NIGHT AS THE FRONT SLOWLY SINKS SOUTH...AIDED BY LOW TO MID LEVEL
FRONTOGENESIS PERSISTING ALONG/NORTH OF THE FRONT. ADDITIONALLY...
AFTER MIDNIGHT TONIGHT...ATTENTION TURNS TO THE SHORTWAVE OVER
SOUTHWEST SASKATCHEWAN. MODELS HAVE SPED UP THIS SHORTWAVE...PERHAPS
MOVING INTO FAR WESTERN PORTIONS OF THE FORECAST AREA BY 12Z TUESDAY
AS SUGGESTED BY THE 17.00Z GFS. 17.00Z NAM/UKMET ARE JUST SLIGHTLY
SLOWER. IN ANY EVENT...DPVA AND A LOWERING TROPOPAUSE WITH THIS
SHORTWAVE WILL LIKELY HELP STRENGTHEN THE LOW TO MID LEVEL
FRONTOGENESIS IN PLACE ALONG/NORTH OF THE FRONT. THUS...THIS
SHORTWAVE SHOULD HELP PROMOTE KEEPING ISOLATED/SCATTERED ACTIVITY
GOING.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 307 AM CDT MON JUN 17 2013
TUESDAY...ATTENTION IS ON THAT SHORTWAVE APPROACHING FAR WESTERN
PORTIONS OF THE FORECAST AREA AT 12Z. AGAIN...WITH MODELS SPEEDING
UP THE SHORTWAVE...THE WAVE PRETTY MUCH EXITS THE AREA BY
18Z...REACHING NORTHWEST INDIANA BY 00Z. MODELS HAVE COME INTO MUCH
BETTER CONSENSUS ON WHETHER THIS SHORTWAVE WILL PRODUCE
PRECIPITATION...WITH THE 17.00Z NAM/GFS/CANADIAN/UKMET/ECMWF AND
HIRES NMM/ARW ALL NOW DEPICTING SOME LIGHT PRECIPITATION. BELIEVE
THE REASON THE QPF IS LIGHT IS THAT THE MOISTURE TRANSPORT IS NOT
ALL THAT GREAT...AND THE AVAILABLE MOISTURE IS SOMEWHAT LIMITED.
HOWEVER...WITH ALL MODELS DEPICTING A FAIRLY STRONG SHORTWAVE PER
500MB PROGS...THE FORCING SHOULD BE ENOUGH TO SQUEEZE OUT SOME
SHOWERS AND POSSIBLY EVEN A THUNDERSTORM OR TWO ONCE DAYTIME HEATING
GETS GOING. THUS...HAVE ADDED 20-30 PERCENT CHANCES TO THE
FORECAST...HIGHEST TUESDAY MORNING. THESE CHANCES MAY NEED TO BE
INCREASED IN LATER FORECASTS. COMBINATION OF CLOUDS ACCOMPANYING THE
SHORTWAVE AND A NORTHEAST LOW LEVEL FLOW OUT OF HIGH PRESSURE IN
UPPER MICHIGAN WILL YIELD A COOLER DAY. HIGHS MOST LOCATIONS SHOULD
END UP IN THE LOW TO MID 70S.
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...THE UPPER LOW OFF THE
PACIFIC NORTHWEST IS PROGGED TO MOVE INLAND DURING THIS
PERIOD...FORCING RIDGING TO INCREASE DOWNSTREAM OVER THE PLAINS.
THIS SETUP WOULD PLACE THE FORECAST AREA IN SUBSIDENCE EAST OF THE
RIDGE AXIS...FAVORABLE FOR HIGH PRESSURE AT THE SURFACE. THIS IS
TRUE ACCORDING TO MODELS...AND WOULD NORMALLY SUGGEST A DRY
FORECAST. HOWEVER...17.00Z NAM AND TO SOME DEGREE THE GFS THROW A
MONKEY WRENCH INTO THIS PLAN...AS THESE MODELS SHOW A NORTH TO SOUTH
ORIENTED SHORTWAVE BARRELING THROUGH THE RIDGE AND MOVING INTO THE
AREA WEDNESDAY NIGHT. BOTH MODELS END UP BRINGING LIGHT
PRECIPITATION INTO THE AREA. MEANWHILE...THE 17.00Z
ECMWF/CANADIAN/UKMET SHOW A MUCH WEAKER REFLECTION OF THIS SHORTWAVE
AS WELL AS SLOWER SPEED. AS A RESULT...THESE MODELS WOULD FAVOR THE
PREVIOUS DRY FORECAST. HAVE STAYED WITH THE DRY FORECAST FOR
NOW...BUT THIS SHORTWAVE WILL NEED SOME WATCHING. OTHERWISE...A COOL
NIGHT LOOKS ON TAP TUESDAY NIGHT WITH THE HIGH PRESSURE AREA IN
PLACE. SOME OF THE TYPICAL COLDER SPOTS COULD DROP INTO THE LOWER
40S. GRADUAL WARMING OF TEMPERATURES EXPECTED FOR HIGHS WEDNESDAY
AND WEDNESDAY NIGHT WITH THE HIGH PRESSURE AREA SLOWLY DRIFTING OFF
TO THE EAST...AS WELL AS AIRMASS MODIFICATION FROM DAYTIME HEATING
TAKING PLACE.
THURSDAY THROUGH THE WEEKEND...
SIMPLY STATED...MORE SUMMER-LIKE WITH INCREASING HUMIDITY...DEALING
WITH CAP CONCERNS AND POTENTIAL FOR MCSS.
17.00Z ECMWF/GFS/CANADIAN AND GFS ENSEMBLES CONTINUE TO SHOW GOOD
RUN-TO-RUN CONSISTENCY ON THE UPPER LEVEL PATTERN. THE TROUGHING
THAT HAS BEEN PERSISTENT IN SOUTHEAST CANADA IS PROGGED TO LIFT OUT
BEGINNING ON THURSDAY. MEANWHILE THE UPPER LOW IN THE PACIFIC
NORTHWEST SLOWLY EJECTS NORTHEAST INTO SOUTH CENTRAL CANADA ON
SUNDAY. THE MOTIONS OF THE TWO TROUGHS ALLOW FOR A FAIRLY
SUBSTANTIAL WARM/MOIST AIR ADVECTION TO TAKE PLACE ACROSS THE PLAINS
AND TOWARDS THE FORECAST AREA. AS A RESULT...THE POTENTIAL EXISTS
FOR MULTIPLE ROUNDS OF CONVECTION AS VARIOUS MCSS FORM. RUN-TO-RUN
MODEL CONSISTENCY AS WELL AS AGREEMENT ON THE MCS TRACKS IS FAIRLY
LOW...AND TO BE EXPECTED. THE ONLY WELL AGREED UPON MCS APPEARS TO
BE ON FRIDAY INTO SATURDAY WHERE AN MCS FORMS OVER THE DAKOTAS AND
TRACKS EAST INTO NORTHERN WI SAT MORNING. THUS...FOLLOWING A MODEL
CONSENSUS FOR PRECIPITATION CHANCES YIELDS 40-60 PERCENT CHANCES
ACROSS THE FORECAST AREA FOR SATURDAY...HIGHEST TOWARDS NORTHERN WI.
THERE ARE INDICATIONS TOO THAT CAPPING WILL BE AN ISSUE TO
CONTEND WITH AS 700MB TEMPS OVER 12C BEGIN ADVECTING TOWARDS THE
AREA FOR THE WEEKEND.
WE WILL DEFINITELY NEED TO WATCH FOR SEVERE WEATHER AND HEAVY RAIN
HEADING INTO THE WEEKEND...GIVEN THE MCS POTENTIAL AND WARM CLOUD
DEPTHS PROGGED IN THE 3500-4500 FT RANGE.
TEMPERATURES ARE EXTREMELY TRICKY AS THEY DEPEND ON HOW CONVECTION
EVOLVES...ESPECIALLY DAYTIME HIGHS. MODELS HAVE TRENDED WARMER FOR
THURSDAY THROUGH THE WEEKEND...SO HAVE FOLLOWED SUIT AND RAISED
HIGHS. HOWEVER...THESE MAY NEED FURTHER INCREASES IF SAY THE CURRENT
17.00Z ECMWF/GFS ARE CORRECT. THIS IS ESPECIALLY TRUE WHERE ON
SATURDAY THEY BOOST 850MB TEMPS UP TO 20-24C...OR 2 STANDARD
DEVIATIONS ABOVE NORMAL. HIGHS COULD EASILY CLIMB INTO THE LOW TO
POSSIBLY EVEN MID 90S IF THIS COMES TRUE. EVAPOTRANSPORATION AND
MOISTURE ADVECTION SHOULD HELP BOOST DEWPOINTS INTO THE 70S...WHICH
THIS LATENT HEATING WILL KEEP HIGHS FROM GETTING MUCH HIGHER THAN
THAT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 637 AM CDT MON JUN 17 2013
CLOUDS TODAY WILL GENERALLY BE LIMITED TO CIRRUS AND DIURNAL CUMULUS
IN THE 5K-6K FT RANGE...IN A DEEPLY MIXED AIRMASS AHEAD OF A SLOWLY
SOUTHWARD MOVING COLD FRONT. WITH THE MIXING...NORTHWEST WINDS OF
AROUND 10KT...GUSTING TO AROUND 20KTS ACROSS THE HIGHER TERRAIN
AREAS...EXPECTED FOR THE LATE MORNING AND AFTERNOON HOURS. AS THE
FRONT APPROACHES THE TAF SITES LATER THIS AFTERNOON/EVENING...WDLY
SCT SHRA/TSRA EXPECTED WITH THE FRONT. WITH THE LIMITED AREAL
COVERAGE OF ANY SHRA/TSRA...LEFT MENTION OUT OF TAFS DURING THE
AFTERNOON/EVENING HOURS UNTIL BETTER DETAILS OF ANY TIMING/COVERAGE
EMERGE.
AN UPPER LEVEL DISTURBANCE APPROACHES AND MOVES ACROSS THE AREA
LATER TONIGHT/TUE MORNING. THIS COMBINED WITH THE FRONT IN THE AREA
AND AN INCREASE OF LOWER TO MID LEVEL MOISTURE PRODUCES ANOTHER
CHANCE OF SHRA/TSRA ACROSS THE TAF SITES. DID CARRY VCSH IN TAF
AFTER 06-07Z AND CIGS IN THE 4K TO 5K FT RANGE IN RESPONSE TO THE
INCREASE OF MOISTURE AND LIFT WITH THE APPROACHING DISTURBANCE. AT
THIS TIME...TOO MUCH UNCERTAINTY ABOUT TIMING/COVERAGE TO INCLUDE A
TSRA/CB MENTION LATE IN THE TAF PERIOD.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM....AJ
AVIATION.....RRS
AREA FORECAST DISCUSSION
NWS NEW YORK NY
241 PM EDT MON JUN 17 2013
.SYNOPSIS...
A COLD FRONT MOVES INTO THE REGION TODAY...THEN STALLS OUT NEARBY
INTO TUESDAY. THE COLD FRONT PUSHES SOUTHEAST OF THE REGION TUESDAY
NIGHT...WITH A WEAK WAVE OF LOW PRESSURE PASSING SOUTH OF THE
REGION ON WEDNESDAY. HIGH PRESSURE RETURNS FOR THE REST OF THE
WEEK. A WARM FRONT APPROACHES THE AREA ON SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SEVERE THUNDERSTORM WATCH 321 IN EFFECT UNTIL 9PM FOR SOUTHERN
CONNECTICUT AND THE LOWER HUDSON VALLEY.
ISOLATED SHOWERS AND THUNDERSTORMS HAVE DEVELOPED THE LOWER
HUDSON VALLEY AND SOUTHWESTERN CONNECTICUT. ISOLATED/SCATTERED
SHOWERS/STORMS SHOULD CONTINUE TO DEVELOP THIS
AFTERNOON...SPECIFICALLY ACROSS THE INTERIOR. THE PRIMARY THREAT
FROM THESE STORMS WILL BE DAMAGING WINDS AND LARGE HAIL.
PREVIOUS DISCUSSION FOLLOWS...
WEAK 700-500 HPA SHORTWAVE CURRENTLY OVER THE OHIO VALLEY MOVES
ACROSS THE AREA THIS AFTERNOON/EVENING. THIS COUPLED WITH A WEAK
FRONT SAGGING INTO THE AREA SHOULD SERVE AS THE TRIGGER FOR A FEW
SHOWERS/TSTORMS...ESPECIALLY ACROSS THE INTERIOR.
1500-2000 J/KG OF MUCAPE IS DEPICTED BY CURRENT SPC MESOANALYSIS
WITH SUFFICIENT BULK SHEAR OF 40-50 KT. LATEST HRRR RUNS SHOW
SCATTERED CONVECTION DEVELOPING ACROSS THE INTERIOR THIS AFTERNOON
AND EVENING. WITH AFTERNOON SEA BREEZES AND LOWER INSTABILITY
CLOSER TO THE COAST...ANTICIPATE ANY CONVECTION WEAKENING AS IT
HEADS SOUTH THIS EVENING.
THERE IS A MODERATE RISK OF RIP CURRENTS INTO THIS EVENING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
ANY CONVECTION SHOULD DIE OUT EARLY THIS EVENING WITH EXIT OF
700-500 HPA SHORTWAVE AND LOSS OF SOLAR HEATING. FOR LOWS TONIGHT
USED A BLEND OF MAV/MET GUIDANCE WITH NAM 2-METER
TEMPERATURES...WITH READINGS FORECAST TO BE A FEW DEGREES ABOVE NORMAL.
700-500 HPA NORTHERN STREAM TROUGH AXIS MOVES IN TUESDAY...AND
SHOULD ACT ON STALLED FRONTAL BOUNDARY TO PRODUCE AT LEAST SCT SHRA/TSRA
ACROSS THE TRI-STATE. STILL SOME VARIATION ON THE MODELS IN TERMS
OF COVERAGE/STRENGTH SO KEPT POPS AT CHANCE FOR NOW.
MAIN QUESTION IS STRENGTH OF INSTABILITY. NAM HAS 1500-2500 J/KG
OF CAPE...WITH THE GFS ONLY AROUND 500 J/KG AND THE ECMWF
SOMEWHERE IN BETWEEN.
THE REGION WILL ALSO BE IN THE RIGHT REAR QUADRANT OF A 75+ KT 300
HPA JET...HAVE 40-50 KT OF BULK SHEAR...AND FAIRLY DECENT LOW
LEVEL HELICITY. SO IF THE HIGHER INSTABILITY IN THE NAM CAN BE
REALIZED...HAVE THE POTENTIAL FOR SOME STRONG TO POSSIBLY SEVERE
STORMS. IF NOT...THEN ONCE AGAIN SHOULD SEE MAINLY AIRMASS
TSTMS...WITH MAYBE AN ISOLD LOW TOPPED SUPERCELL LIKE TODAY.
FOR HIGHS TUESDAY USED A BLEND OF MIXING DOWN FROM 900 HPA NEAR
THE COAST TO 825 HPA WELL INLAND...WITH NAM 2-METER TEMPERATURES
AND A BLEND OF MAV/MET GUIDANCE. EXPECT HIGHS TO BE AROUND 5
DEGREES ABOVE NORMAL.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
MODELS COMING INTO SOMEWHAT BETTER AGREEMENT WITH EVOLUTION OF THE
MAIN SYNOPTIC FEATURES FOR MIDWEEK...WITH A STRONG UPPER LOW CURLING
THROUGH EASTERN CANADA AND A COLD FRONT PUSHING SOUTHEAST OF THE
REGION TUESDAY NIGHT. THIS SHOULD HAVE ANY SHRA/TSRA ACTIVITY
TUESDAY NIGHT WEAKENING AND GRADUALLY SINKING SE OF THE REGION.
FOR WED...MODELS ARE KEYING IN ON SHORTWAVE ENERGY CURRENTLY OVER
THE CANADIAN ROCKIES...ROUNDING THE BASE OF THE NE US TROUGH...AND
HELPING TO INDUCE A WAVE OF LOW PRESSURE ALONG THE COLD FRONT. AT
THIS POINT...IT APPEARS WE SHOULD BE MAINLY DRY...BUT COULD BE ON
THE NORTHERN FRINGE OF ANY PRECIP WITH THIS FEATURE. IT WILL HAVE TO
BE WATCHED. IF NOTHING ELSE...A BIT MORE CLOUD COVER AND ONSHORE
FLOW TO THE NORTH OF THE LOW WOULD HOLD TEMPS BELOW SEASONABLE
LEVELS.
THEREAFTER...MODELS IN DECENT AGREEMENT WITH MEAN TROUGHING
CONTINUING OVER THE NORTHEAST...WITH CANADIAN HIGH PRESSURE GRADUALLY
BUILDING INTO THE REGION AND IN CONTROL THROUGH SATURDAY. THIS WILL
RESULT IN FAIR AND SEASONABLE WARM CONDITIONS THROUGH THE PERIOD.
WEAK PIECES OF SHORTWAVE ENERGY ROUNDING THE BASE OF THE TROUGH
COULD SET OFF ISOLATED PULSE SHRA/TSRA ACTIVITY EACH AFT/EVE...MAINLY
OFF THE NW HIGHER ELEVATIONS.
HEIGHTS MAY BEGIN TO BUILD THIS WEEKEND INTO EARLY NEXT WEEK...WITH
A TREND TOWARDS MORE SUMMER LIKE WEATHER. THIS WOULD ALSO BRING
POTENTIAL FOR MCS ACTIVITY AS THE REGION LIES ON THE SOUTHERN EDGE
OF THE WESTERLIES.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
THERE IS THE POTENTIAL FOR TWO EPISODES OF CONVECTION TO IMPACT THE
TERMINALS...THE FIRST ALONG AND AHEAD OF A PRE-FRONTAL TROF THIS
AFTERNOON...AND THEN AGAIN EARLY THIS EVENING AS A WEAK COLD
FRONT DROPS SE ACROSS UPSTATE NY AND NEW ENGLAND. DUE TO STRONG
WIND SHEAR ALOFT AND HIGH INSTABILITY...SOME OF THESE STORMS COULD
BECOME STRONG...AND POSSIBLY SEVERE. THE MAIN SEVERE THREAT IS TO
THE NORTH OF THE NYC TERMINALS AT THIS TIME. THE BEST CHANCE OF
ORGANIZED CONVECTION WILL BE WITH THE COLD FRONT THIS EVENING.
S/SW WINDS AT 8 TO 12 KT...G20KT FOR THE REST OF THIS AFTERNOON...
BECOMING LIGHT AND VARIABLE THIS EVENING AS A COLD FRONT STALLS
CLOSE TO THE AREA...THEN E/SE WED MORNING DEPENDING ON THE
PROXIMITY OF THE FRONT. THERE IS UNCERTAINTY WITH THE GUIDANCE AS
TO THE LOCATION OF THE FRONT TUE MORNING...WHICH WILL DEPEND OF
THE AMOUNT OF SOUTHWARD PROGRESS IT MAKES THIS EVENING. WINDS ON
TUE MAY VARY CONSIDERABLY FROM EITHER A LIGHT E/SE TO W/SW FLOW.
GENERALLY VFR...BUT MVFR/IFR IN ANY CONVECTION. RESIDUAL LOW-LEVEL
MOISTURE AND AN ONSHORE FLOW TONIGHT INTO TUE MAY ALSO RESULT IN
FOG/HAZE...ESPECIALLY OUTSIDE OF THE NYC TERMINALS.
POTENTIAL FOR ANOTHER ROUND OF STRONG CONVECTION TUE AFT...BUT
THIS WILL HEAVILY DEPEND ON THE LOCATION OF THE FRONT.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: AMENDMENTS LIKELY DUE TO THE TIMING AND
LOCATION OF CONVECTION THIS AFT AND EVE.
KLGA FCSTER COMMENTS: AMENDMENTS LIKELY DUE TO THE TIMING AND
LOCATION OF CONVECTION THIS AFT AND EVE.
KEWR FCSTER COMMENTS: AMENDMENTS LIKELY DUE TO THE TIMING AND
LOCATION OF CONVECTION THIS AFT AND EVE.
KTEB FCSTER COMMENTS: AMENDMENTS LIKELY DUE TO THE TIMING AND
LOCATION OF CONVECTION THIS AFT AND EVE.
KHPN FCSTER COMMENTS: AMENDMENTS LIKELY DUE TO THE TIMING AND
LOCATION OF CONVECTION THIS AFT AND EVE.
KISP FCSTER COMMENTS: AMENDMENTS LIKELY DUE TO THE TIMING AND
LOCATION OF CONVECTION THIS AFT AND EVE.
.OUTLOOK FOR 18Z TUE THROUGH SAT...
.TUE...SCT SHOWERS AND TSTMS COULD BRING MVFR OR LOWER CONDITIONS.
.WED-SAT...VFR.
&&
.MARINE...
WAVEWATCH RUNNING AROUND 1 FT TOO HIGH...SO ADJUSTED DOWN A FT OR
SO.
WITH A RELATIVELY LIGHT PRESSURE GRADIENT OVER THE REGION EXPECT
WINDS TO BE 10 KT OR LESS THROUGH TUESDAY...OUTSIDE OF AFTERNOON
SEABREEZES EACH DAY AND ANY THUNDERSTORMS. WAVES...EVEN WITH A
PERSISTENT 2 FT SWELL SHOULD REMAIN BELOW SCA LEVELS ON THE OCEAN
WATERS THROUGH TUESDAY.
MARGINAL SCA SEAS ARE POSSIBLE WEDNESDAY WITH A WEAK WAVE OF LOW
PRESSURE MOVING TO THE SOUTH OF THE REGION. OTHERWISE...SUB SCA
CONDITIONS ARE LIKELY FOR MID THROUGH LATE WEEK AS HIGH PRESSURE BUILDS
IN.
&&
.HYDROLOGY...
BASIN AVERAGE QPF FROM ANY SHRA/TSTMS THIS AFTERNOON/EARLY EVENING
SHOULD BE LESS THAN .1 INCHES. WITH PRECIPITABLE WATERS AROUND 1
INCH...THE PROBABILITY OF LOCALLY HEAVY RAINFALL...AND HENCE ANY
SIGNIFICANT HYDROLOGIC IMPACT IS LOW.
THERE IS THE POTENTIAL FOR 1/3-2/3 AN INCH OF BASIN AVERAGE
QPF...WITH LOCALLY HIGHER AMOUNTS POSSIBLE WITH CONVECTION
TUESDAY/TUESDAY EVENING. WITH PRECIPITABLE WATERS OF 1.25-1.5
INCHES...THERE IS THE POTENTIAL FOR LOCALLY HEAVY RAINFALL WITH
ANY STRONGER CONVECTION. THIS COULD CAUSE MINOR FLOODING OF
URBAN/POOR DRAINAGE AREAS.
THE PROBABILITY FOR WIDESPREAD SIGNIFICANT RAINFALL IS LOW FROM
THE MIDDLE THROUGH THE END OF THE WEEK.
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.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MALOIT/NV
NEAR TERM...DS
SHORT TERM...MALOIT
LONG TERM...NV
AVIATION...DW
MARINE...MALOIT/NV
HYDROLOGY...MALOIT/NV
AREA FORECAST DISCUSSION
NWS NEW YORK NY
140 PM EDT MON JUN 17 2013
.SYNOPSIS...
A COLD FRONT MOVES INTO THE REGION TODAY...THEN STALLS OUT NEARBY
INTO TUESDAY. THE COLD FRONT PUSHES SOUTHEAST OF THE REGION TUESDAY
NIGHT...WITH A WEAK WAVE OF LOW PRESSURE PASSING SOUTH OF THE
REGION ON WEDNESDAY. HIGH PRESSURE RETURNS FOR THE REST OF THE
WEEK. A WARM FRONT APPROACHES THE AREA ON SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SEVERE THUNDERSTORM WATCH 321 IN EFFECT UNTIL 9PM FOR SOUTHERN
CONNECTICUT AND THE LOWER HUDSON VALLEY.
ISOLATED SHOWERS AND THUNDERSTORMS HAVE DEVELOPED THE LOWER
HUDSON VALLEY AND SOUTHWESTERN CONNECTICUT. ISOLATED/SCATTERED
SHOWERS/STORMS SHOULD CONTINUE TO DEVELOP THIS
AFTERNOON...SPECIFICALLY ACROSS THE INTERIOR. THE PRIMARY THREAT
FROM THESE STORMS WILL BE DAMAGING WINDS AND LARGE HAIL.
PREVIOUS DISCUSSION FOLLOWS...
WEAK 700-500 HPA SHORTWAVE CURRENTLY OVER THE OHIO VALLEY MOVES
ACROSS THE AREA THIS AFTERNOON/EVENING. THIS COUPLED WITH A WEAK
FRONT SAGGING INTO THE AREA SHOULD SERVE AS THE TRIGGER FOR A FEW
SHOWERS/TSTORMS...ESPECIALLY ACROSS THE INTERIOR.
1500-2000 J/KG OF MUCAPE IS DEPICTED BY CURRENT SPC MESOANALYSIS
WITH SUFFICIENT BULK SHEAR OF 40-50 KT. LATEST HRRR RUNS SHOW
SCATTERED CONVECTION DEVELOPING ACROSS THE INTERIOR THIS AFTERNOON
AND EVENING. WITH AFTERNOON SEA BREEZES AND LOWER INSTABILITY
CLOSER TO THE COAST...ANTICIPATE ANY CONVECTION WEAKENING AS IT
HEADS SOUTH THIS EVENING.
THERE IS A MODERATE RISK OF RIP CURRENTS INTO THIS EVENING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
ANY CONVECTION SHOULD DIE OUT EARLY THIS EVENING WITH EXIT OF
700-500 HPA SHORTWAVE AND LOSS OF SOLAR HEATING. FOR LOWS TONIGHT
USED A BLEND OF MAV/MET GUIDANCE WITH NAM 2-METER
TEMPERATURES...WITH READINGS FORECAST TO BE A FEW DEGREES ABOVE NORMAL.
700-500 HPA NORTHERN STREAM TROUGH AXIS MOVES IN TUESDAY...AND
SHOULD ACT ON STALLED FRONTAL BOUNDARY TO PRODUCE AT LEAST SCT SHRA/TSRA
ACROSS THE TRI-STATE. STILL SOME VARIATION ON THE MODELS IN TERMS
OF COVERAGE/STRENGTH SO KEPT POPS AT CHANCE FOR NOW.
MAIN QUESTION IS STRENGTH OF INSTABILITY. NAM HAS 1500-2500 J/KG
OF CAPE...WITH THE GFS ONLY AROUND 500 J/KG AND THE ECMWF
SOMEWHERE IN BETWEEN.
THE REGION WILL ALSO BE IN THE RIGHT REAR QUADRANT OF A 75+ KT 300
HPA JET...HAVE 40-50 KT OF BULK SHEAR...AND FAIRLY DECENT LOW
LEVEL HELICITY. SO IF THE HIGHER INSTABILITY IN THE NAM CAN BE
REALIZED...HAVE THE POTENTIAL FOR SOME STRONG TO POSSIBLY SEVERE
STORMS. IF NOT...THEN ONCE AGAIN SHOULD SEE MAINLY AIRMASS
TSTMS...WITH MAYBE AN ISOLD LOW TOPPED SUPERCELL LIKE TODAY.
FOR HIGHS TUESDAY USED A BLEND OF MIXING DOWN FROM 900 HPA NEAR
THE COAST TO 825 HPA WELL INLAND...WITH NAM 2-METER TEMPERATURES
AND A BLEND OF MAV/MET GUIDANCE. EXPECT HIGHS TO BE AROUND 5
DEGREES ABOVE NORMAL.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
MODELS COMING INTO SOMEWHAT BETTER AGREEMENT WITH EVOLUTION OF THE
MAIN SYNOPTIC FEATURES FOR MIDWEEK...WITH A STRONG UPPER LOW CURLING
THROUGH EASTERN CANADA AND A COLD FRONT PUSHING SOUTHEAST OF THE
REGION TUESDAY NIGHT. THIS SHOULD HAVE ANY SHRA/TSRA ACTIVITY
TUESDAY NIGHT WEAKENING AND GRADUALLY SINKING SE OF THE REGION.
FOR WED...MODELS ARE KEYING IN ON SHORTWAVE ENERGY CURRENTLY OVER
THE CANADIAN ROCKIES...ROUNDING THE BASE OF THE NE US TROUGH...AND
HELPING TO INDUCE A WAVE OF LOW PRESSURE ALONG THE COLD FRONT. AT
THIS POINT...IT APPEARS WE SHOULD BE MAINLY DRY...BUT COULD BE ON
THE NORTHERN FRINGE OF ANY PRECIP WITH THIS FEATURE. IT WILL HAVE TO
BE WATCHED. IF NOTHING ELSE...A BIT MORE CLOUD COVER AND ONSHORE
FLOW TO THE NORTH OF THE LOW WOULD HOLD TEMPS BELOW SEASONABLE
LEVELS.
THEREAFTER...MODELS IN DECENT AGREEMENT WITH MEAN TROUGHING
CONTINUING OVER THE NORTHEAST...WITH CANADIAN HIGH PRESSURE GRADUALLY
BUILDING INTO THE REGION AND IN CONTROL THROUGH SATURDAY. THIS WILL
RESULT IN FAIR AND SEASONABLE WARM CONDITIONS THROUGH THE PERIOD.
WEAK PIECES OF SHORTWAVE ENERGY ROUNDING THE BASE OF THE TROUGH
COULD SET OFF ISOLATED PULSE SHRA/TSRA ACTIVITY EACH AFT/EVE...MAINLY
OFF THE NW HIGHER ELEVATIONS.
HEIGHTS MAY BEGIN TO BUILD THIS WEEKEND INTO EARLY NEXT WEEK...WITH
A TREND TOWARDS MORE SUMMER LIKE WEATHER. THIS WOULD ALSO BRING
POTENTIAL FOR MCS ACTIVITY AS THE REGION LIES ON THE SOUTHERN EDGE
OF THE WESTERLIES.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
A SURFACE TROUGH REMAINS OVER THE TERMINALS TODAY. WEAK COLD FRONT
THEN DROPS DOWN FROM NW THIS EVE AND MAY PRODUCE SCT CONVECTION...
PRIMARILY NORTH AND WEST OF THE NYC TERMINALS FROM 22Z TO 02Z.
OTHERWISE...AN ISOLATED AFTERNOON SHOWER OR TSTM IS NOT OUT OF THE
QUESTION. TIMING AND PLACEMENT TOO LOW TO INCLUDE IN THE TAFS FOR
NOW.
SOUTHWEST WINDS LESS THAN 10 KT TO START. SPEEDS GRADUALLY INCREASE
THIS MORNING AND INTO THE AFTERNOON WITH SPEEDS BETWEEN 8-15 KT
SUSTAINED. SEA BREEZES LIKELY AT THE COASTAL TERMINALS THIS
AFTERNOON. OCCASIONAL GUSTS TO NEAR 20 KT ARE POSSIBLE TODAY.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED TO ADJUST TIMING OF
ANY WIND SHIFTS AND TO ADD POSSIBLE LATE DAY CONVECTION. AN OCCASIONAL
GUST TO 20 KT CAN NOT BE RULED OUT.
KLGA FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED TO ADJUST TIMING OF
ANY WIND SHIFTS AND TO ADD POSSIBLE LATE DAY CONVECTION. AN
OCCASIONAL GUST INTO THE UPPER TEENS CAN NOT BE RULED OUT.
KEWR FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED TO ADD POSSIBLE
LATE DAY CONVECTION.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED TO ADD POSSIBLE
LATE DAY CONVECTION.
KHPN FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED TO ACCOUNT FOR LATE
DAY SEABREEZE AND TO ADD CONVECTION.
KISP FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED TO ADJUST TIMING OF
ANY WIND SHIFTS. AN OCCASIONAL GUST INTO THE UPPER TEENS CAN NOT BE
RULED OUT.
.OUTLOOK FOR 12Z TUE THROUGH FRI...
.TUE...SCT SHOWERS AND ISOLD-SCT TSTMS COULD BRING MVFR OR LOWER
CONDITIONS.
.WED-FRI...VFR.
&&
.MARINE...
WAVEWATCH RUNNING AROUND 1 FT TOO HIGH...SO ADJUSTED DOWN A FT OR
SO.
WITH A RELATIVELY LIGHT PRESSURE GRADIENT OVER THE REGION EXPECT
WINDS TO BE 10 KT OR LESS THROUGH TUESDAY...OUTSIDE OF AFTERNOON
SEABREEZES EACH DAY AND ANY THUNDERSTORMS. WAVES...EVEN WITH A
PERSISTENT 2 FT SWELL SHOULD REMAIN BELOW SCA LEVELS ON THE OCEAN
WATERS THROUGH TUESDAY.
MARGINAL SCA SEAS ARE POSSIBLE WEDNESDAY WITH A WEAK WAVE OF LOW
PRESSURE MOVING TO THE SOUTH OF THE REGION. OTHERWISE...SUB SCA
CONDITIONS ARE LIKELY FOR MID THROUGH LATE WEEK AS HIGH PRESSURE BUILDS
IN.
&&
.HYDROLOGY...
BASIN AVERAGE QPF FROM ANY SHRA/TSTMS THIS AFTERNOON/EARLY EVENING
SHOULD BE LESS THAN .1 INCHES. WITH PRECIPITABLE WATERS AROUND 1
INCH...THE PROBABILITY OF LOCALLY HEAVY RAINFALL...AND HENCE ANY
SIGNIFICANT HYDROLOGIC IMPACT IS LOW.
THERE IS THE POTENTIAL FOR 1/3-2/3 AN INCH OF BASIN AVERAGE
QPF...WITH LOCALLY HIGHER AMOUNTS POSSIBLE WITH CONVECTION
TUESDAY/TUESDAY EVENING. WITH PRECIPITABLE WATERS OF 1.25-1.5
INCHES...THERE IS THE POTENTIAL FOR LOCALLY HEAVY RAINFALL WITH
ANY STRONGER CONVECTION. THIS COULD CAUSE MINOR FLOODING OF
URBAN/POOR DRAINAGE AREAS.
THE PROBABILITY FOR WIDESPREAD SIGNIFICANT RAINFALL IS LOW FROM
THE MIDDLE THROUGH THE END OF THE WEEK.
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.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MALOIT/NV
NEAR TERM...DS
SHORT TERM...MALOIT
LONG TERM...NV
AVIATION...DW
MARINE...MALOIT/NV
HYDROLOGY...MALOIT/NV
AREA FORECAST DISCUSSION
NWS NEW YORK NY
104 PM EDT MON JUN 17 2013
.SYNOPSIS...
A COLD FRONT MOVES INTO THE REGION TODAY...THEN STALLS OUT NEARBY
INTO TUESDAY. THE COLD FRONT PUSHES SOUTHEAST OF THE REGION TUESDAY
NIGHT...WITH A WEAK WAVE OF LOW PRESSURE PASSING SOUTH OF THE
REGION ON WEDNESDAY. HIGH PRESSURE RETURNS FOR THE REST OF THE
WEEK. A WARM FRONT APPROACHES THE AREA ON SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
ISOLATED SHOWERS AND THUNDERSTORMS HAS DEVELOPED OVER ORANGE
COUNTY. OTHER ISOLATED SHOWERS/STORMS MAY CONTINUE TO DEVELOP THIS
AFTERNOON...SPECIFICALLY ACROSS THE INTERIOR. UPDATED OTHER GRIDS
TO REFLECT CURRENT TRENDS IN THE NEAR TERM.
1630 UTC SPC DAY ONE OUTLOOK HAS PLACED PORTIONS OF OUR AREA IN A
SLIGHT RISK FOR SEVERE STORMS...MAINLY OVER SOUTHERN CONNECTICUT.
THE PRIMARY THREAT WILL BE DAMAGING WINDS.
OTHERWISE...WEAK 700-500 HPA SHORTWAVE CURRENTLY OVER THE OHIO
VALLEY MOVES ACROSS THE AREA THIS AFTERNOON/EVENING. THIS COUPLED
WITH A WEAK FRONT SAGGING INTO THE AREA SHOULD SERVE AS THE
TRIGGER FOR A FEW SHOWERS/TSTORMS...ESPECIALLY ACROSS THE
INTERIOR.
1500-2000 J/KG OF MUCAPE IS DEPICTED BY CURRENT SPC MESOANALYSIS
WITH SUFFICIENT BULK SHEAR OF 40-50 KT. LATEST HRRR RUNS SHOW
SCATTERED CONVECTION DEVELOPING ACROSS THE INTERIOR THIS AFTERNOON
AND EVENING. WITH AFTERNOON SEA BREEZES AND LOWER INSTABILITY
CLOSER TO THE COAST...ANTICIPATE ANY CONVECTION WEAKENING AS IT
HEADS SOUTH THIS EVENING.
THERE IS A MODERATE RISK OF RIP CURRENTS INTO THIS EVENING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
ANY CONVECTION SHOULD DIE OUT EARLY THIS EVENING WITH EXIT OF
700-500 HPA SHORTWAVE AND LOSS OF SOLAR HEATING. FOR LOWS TONIGHT
USED A BLEND OF MAV/MET GUIDANCE WITH NAM 2-METER
TEMPERATURES...WITH READINGS FORECAST TO BE A FEW DEGREES ABOVE NORMAL.
700-500 HPA NORTHERN STREAM TROUGH AXIS MOVES IN TUESDAY...AND
SHOULD ACT ON STALLED FRONTAL BOUNDARY TO PRODUCE AT LEAST SCT SHRA/TSRA
ACROSS THE TRI-STATE. STILL SOME VARIATION ON THE MODELS IN TERMS
OF COVERAGE/STRENGTH SO KEPT POPS AT CHANCE FOR NOW.
MAIN QUESTION IS STRENGTH OF INSTABILITY. NAM HAS 1500-2500 J/KG
OF CAPE...WITH THE GFS ONLY AROUND 500 J/KG AND THE ECMWF
SOMEWHERE IN BETWEEN.
THE REGION WILL ALSO BE IN THE RIGHT REAR QUADRANT OF A 75+ KT 300
HPA JET...HAVE 40-50 KT OF BULK SHEAR...AND FAIRLY DECENT LOW
LEVEL HELICITY. SO IF THE HIGHER INSTABILITY IN THE NAM CAN BE
REALIZED...HAVE THE POTENTIAL FOR SOME STRONG TO POSSIBLY SEVERE
STORMS. IF NOT...THEN ONCE AGAIN SHOULD SEE MAINLY AIRMASS
TSTMS...WITH MAYBE AN ISOLD LOW TOPPED SUPERCELL LIKE TODAY.
FOR HIGHS TUESDAY USED A BLEND OF MIXING DOWN FROM 900 HPA NEAR
THE COAST TO 825 HPA WELL INLAND...WITH NAM 2-METER TEMPERATURES
AND A BLEND OF MAV/MET GUIDANCE. EXPECT HIGHS TO BE AROUND 5
DEGREES ABOVE NORMAL.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
MODELS COMING INTO SOMEWHAT BETTER AGREEMENT WITH EVOLUTION OF THE
MAIN SYNOPTIC FEATURES FOR MIDWEEK...WITH A STRONG UPPER LOW CURLING
THROUGH EASTERN CANADA AND A COLD FRONT PUSHING SOUTHEAST OF THE
REGION TUESDAY NIGHT. THIS SHOULD HAVE ANY SHRA/TSRA ACTIVITY
TUESDAY NIGHT WEAKENING AND GRADUALLY SINKING SE OF THE REGION.
FOR WED...MODELS ARE KEYING IN ON SHORTWAVE ENERGY CURRENTLY OVER
THE CANADIAN ROCKIES...ROUNDING THE BASE OF THE NE US TROUGH...AND
HELPING TO INDUCE A WAVE OF LOW PRESSURE ALONG THE COLD FRONT. AT
THIS POINT...IT APPEARS WE SHOULD BE MAINLY DRY...BUT COULD BE ON
THE NORTHERN FRINGE OF ANY PRECIP WITH THIS FEATURE. IT WILL HAVE TO
BE WATCHED. IF NOTHING ELSE...A BIT MORE CLOUD COVER AND ONSHORE
FLOW TO THE NORTH OF THE LOW WOULD HOLD TEMPS BELOW SEASONABLE
LEVELS.
THEREAFTER...MODELS IN DECENT AGREEMENT WITH MEAN TROUGHING
CONTINUING OVER THE NORTHEAST...WITH CANADIAN HIGH PRESSURE GRADUALLY
BUILDING INTO THE REGION AND IN CONTROL THROUGH SATURDAY. THIS WILL
RESULT IN FAIR AND SEASONABLE WARM CONDITIONS THROUGH THE PERIOD.
WEAK PIECES OF SHORTWAVE ENERGY ROUNDING THE BASE OF THE TROUGH
COULD SET OFF ISOLATED PULSE SHRA/TSRA ACTIVITY EACH AFT/EVE...MAINLY
OFF THE NW HIGHER ELEVATIONS.
HEIGHTS MAY BEGIN TO BUILD THIS WEEKEND INTO EARLY NEXT WEEK...WITH
A TREND TOWARDS MORE SUMMER LIKE WEATHER. THIS WOULD ALSO BRING
POTENTIAL FOR MCS ACTIVITY AS THE REGION LIES ON THE SOUTHERN EDGE
OF THE WESTERLIES.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
A SURFACE TROUGH REMAINS OVER THE TERMINALS TODAY. WEAK COLD FRONT
THEN DROPS DOWN FROM NW THIS EVE AND MAY PRODUCE SCT CONVECTION...
PRIMARILY NORTH AND WEST OF THE NYC TERMINALS FROM 22Z TO 02Z.
OTHERWISE...AN ISOLATED AFTERNOON SHOWER OR TSTM IS NOT OUT OF THE
QUESTION. TIMING AND PLACEMENT TOO LOW TO INCLUDE IN THE TAFS FOR
NOW.
SOUTHWEST WINDS LESS THAN 10 KT TO START. SPEEDS GRADUALLY INCREASE
THIS MORNING AND INTO THE AFTERNOON WITH SPEEDS BETWEEN 8-15 KT
SUSTAINED. SEA BREEZES LIKELY AT THE COASTAL TERMINALS THIS
AFTERNOON. OCCASIONAL GUSTS TO NEAR 20 KT ARE POSSIBLE TODAY.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED TO ADJUST TIMING OF
ANY WIND SHIFTS AND TO ADD POSSIBLE LATE DAY CONVECTION. AN OCCASIONAL
GUST TO 20 KT CAN NOT BE RULED OUT.
KLGA FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED TO ADJUST TIMING OF
ANY WIND SHIFTS AND TO ADD POSSIBLE LATE DAY CONVECTION. AN
OCCASIONAL GUST INTO THE UPPER TEENS CAN NOT BE RULED OUT.
KEWR FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED TO ADD POSSIBLE
LATE DAY CONVECTION.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED TO ADD POSSIBLE
LATE DAY CONVECTION.
KHPN FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED TO ACCOUNT FOR LATE
DAY SEABREEZE AND TO ADD CONVECTION.
KISP FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED TO ADJUST TIMING OF
ANY WIND SHIFTS. AN OCCASIONAL GUST INTO THE UPPER TEENS CAN NOT BE
RULED OUT.
.OUTLOOK FOR 12Z TUE THROUGH FRI...
.TUE...SCT SHOWERS AND ISOLD-SCT TSTMS COULD BRING MVFR OR LOWER
CONDITIONS.
.WED-FRI...VFR.
&&
.MARINE...
WAVEWATCH RUNNING AROUND 1 FT TOO HIGH...SO ADJUSTED DOWN A FT OR
SO.
WITH A RELATIVELY LIGHT PRESSURE GRADIENT OVER THE REGION EXPECT
WINDS TO BE 10 KT OR LESS THROUGH TUESDAY...OUTSIDE OF AFTERNOON
SEABREEZES EACH DAY AND ANY THUNDERSTORMS. WAVES...EVEN WITH A
PERSISTENT 2 FT SWELL SHOULD REMAIN BELOW SCA LEVELS ON THE OCEAN
WATERS THROUGH TUESDAY.
MARGINAL SCA SEAS ARE POSSIBLE WEDNESDAY WITH A WEAK WAVE OF LOW
PRESSURE MOVING TO THE SOUTH OF THE REGION. OTHERWISE...SUB SCA
CONDITIONS ARE LIKELY FOR MID THROUGH LATE WEEK AS HIGH PRESSURE BUILDS
IN.
&&
.HYDROLOGY...
BASIN AVERAGE QPF FROM ANY SHRA/TSTMS THIS AFTERNOON/EARLY EVENING
SHOULD BE LESS THAN .1 INCHES. WITH PRECIPITABLE WATERS AROUND 1
INCH...THE PROBABILITY OF LOCALLY HEAVY RAINFALL...AND HENCE ANY
SIGNIFICANT HYDROLOGIC IMPACT IS LOW.
THERE IS THE POTENTIAL FOR 1/3-2/3 AN INCH OF BASIN AVERAGE
QPF...WITH LOCALLY HIGHER AMOUNTS POSSIBLE WITH CONVECTION
TUESDAY/TUESDAY EVENING. WITH PRECIPITABLE WATERS OF 1.25-1.5
INCHES...THERE IS THE POTENTIAL FOR LOCALLY HEAVY RAINFALL WITH
ANY STRONGER CONVECTION. THIS COULD CAUSE MINOR FLOODING OF
URBAN/POOR DRAINAGE AREAS.
THE PROBABILITY FOR WIDESPREAD SIGNIFICANT RAINFALL IS LOW FROM
THE MIDDLE THROUGH THE END OF THE WEEK.
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.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MALOIT/NV
NEAR TERM...DS
SHORT TERM...MALOIT
LONG TERM...NV
AVIATION...DW
MARINE...MALOIT/NV
HYDROLOGY...MALOIT/NV
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
400 PM EDT MON JUN 17 2013
.SYNOPSIS...
19Z WATER VAPOR AND H4 RAP ANALYSIS SHOW A NEARLY ZONAL FLOW ALONG
THE NORTHERN GULF COAST THIS AFTERNOON OVER-TOP AN EAST-WEST
ORIENTED UPPER LEVEL RIDGE ACROSS THE CENTRAL GULF OF MEXICO AND
FLORIDA PENINSULA. AT THE SURFACE...SUBTROPICAL RIDGE AXIS IS
ALIGNED ACROSS THE STATE JUST TO THE NORTH OF LAKE OKEECHOBEE.
SYNOPTIC FLOW AROUND THIS RIDGE IS HELPING TO ACCELERATE THE
SEA-BREEZE INLAND ACROSS THE NATURE COAST WITH A SLOWER INLAND
EXPANSION FURTHER SOUTH WHERE THE FLOW IS LIGHTER OR EVEN SLIGHTLY
OPPOSED. THUNDERSTORM ACTIVITY HAS BEEN RATHER LIMITED SO FAR WITH
WIDELY SCT CELLS TRYING TO DEVELOP ALONG AND INLAND FROM THE I-75
CORRIDOR.
&&
.SHORT TERM (TONIGHT THROUGH WEDNESDAY)...
REST OF TODAY INTO TONIGHT...
STILL ANTICIPATE AN ACTIVE EVENING OF THUNDERSTORMS ACROSS THE
INTERIOR CENTRAL AND SOUTHERN ZONES TO THE SOUTH OF TAMPA BAY. HIGH
RESOLUTION GUIDANCE WAS ACTUALLY HINTING AT A LATE START...AND
PLENTY OF DAYLIGHT/HEATING LEFT TO GO. EAST AND WEST COAST
SEA-BREEZE COLLISION WILL BE MAXIMIZED LATER THIS AFTERNOON FROM
POLK COUNTY TO HIGHLANDS AND THEN SOUTHWEST TOWARD FT. MYERS. WILL
KEEP CHANCE POPS IN THE GRIDS THROUGH THE LATE EVENING HOURS FOR
THESE AREA. FURTHER NORTH...ESPECIALLY NORTH OF I-4...THE ONLY
CHANCES FOR STORMS NOW LOOKS TO BE WELL INLAND WITH THE PROPAGATING
SEA-BREEZE...AND EVENTUALLY THIS CONVERGENT ZONE SHOULD PUSH EAST OF
OUR COUNTIES INTO NORTHEAST FLORIDA AND END THE THUNDERSTORM THREAT.
TUESDAY THROUGH WEDNESDAY...
UPPER LEVEL PATTERN WILL BEGIN TO SLOWLY AMPLIFY OVER THE EASTERN
THIRD OF THE NATION INTO THE MIDDLE PART OF THE WEEK AND HELP PUSH A
COLD FRONT INTO THE SOUTHEASTERN STATES. TYPICAL FOR THIS TIME OF
YEAR...THIS FRONT WILL NOT REACH OUR AREA AND IS PROGGED BY GLOBAL
GUIDANCE TO STALL AND WASH OUT NEAR THE I-10 CORRIDOR. THE
SUBTROPICAL RIDGE AXIS WILL HOLD STRONG ACROSS THE FORECAST AREA AND
KEEP OUR WEATHER PATTERN FAIRLY TYPICAL FOR MID/LATE JUNE. FOR
TUESDAY...SOME INDICATIONS OF A LESS FAVORABLE THERMODYNAMIC COLUMN
FOR DEEP CONVECTION ALONG WITH A QUICKLY MOVING SEA-BREEZE WILL KEEP
POPS LOWER TO THE NORTH OF I-4. BY WEDNESDAY...THE RIDGE AXIS IS
SUPPRESSED DOWN TOWARD OUR SOUTHERN ZONES BY THE FRONT TO OUR NORTH.
THIS POSITION SHOULD SET UP A LARGER PORTION OF AREA TO SEE A
QUICKLY MOVING SEA-BREEZE...AND LOWER RAIN CHANCES AT THE COAST.
HAVE NOTICED A WARMING OF THE SHELF WATERS IN THE PAST WEEK OR 2 AND
RESULTING SPIKE IN COASTAL DEWPOINTS LATELY. FOR THIS REASON...HEAT
INDICES HAVE BECOME MORE OF AN ISSUE ONCE AGAIN. FORECAST THE NEXT
FEW DAYS WILL SHOW MAXIMUM HEAT INDICES BETWEEN 100-105
DEGREES...ESPECIALLY NEAR THE COAST.
&&
.LONG TERM (WEDNESDAY NIGHT-SUNDAY)...
WEAK U/L TROUGH WILL REMAIN OVER THE SOUTHEAST U.S. AND NORTHEAST
GULF THURSDAY AND FRIDAY...WITH THE WESTERLIES LIFTING WELL NORTH OF
THE AREA OVER THE GREAT LAKES AND NORTHEAST ON FRIDAY AS AN U/L
RIDGE OVER THE WESTERN ATLANTIC BUILDS WESTWARD. THIS WILL PINCH
OFF THE WEAK TROUGH OVER THE SOUTHEAST U.S. AND NORTHEAST GULF
SEPARATING IT FROM THE WESTERLIES...WHICH WILL THEN PERSIST JUST
NORTH OF THE AREA THROUGH THE WEEKEND. A WEAK SURFACE FRONTAL
BOUNDARY WILL REMAIN OVER NORTH FLORIDA THURSDAY...TRANSITIONING
INTO A WEAK INVERTED TROUGH WHICH WILL EXTEND FROM THE NORTHEAST
GULF OFF THE GEORGIA/S CAROLINA COAST. SURFACE RIDGE AXIS WILL
GRADUALLY SHIFT EAST OF THE REGION LATE THURSDAY...WITH BOUNDARY
LAYER WINDS SHIFTING FROM THE SOUTHWEST ON THURSDAY TO THE
EAST-SOUTHEAST FRIDAY THROUGH SUNDAY. SCATTERED THUNDERSTORMS
WILL DEVELOP EACH AFTERNOON...WITH MAJORITY OF ACTIVITY OVER THE
INTERIOR THURSDAY DUE TO THE ONSHORE FLOW. FRIDAY WILL BE A
TRANSITION DAY WITH ACTIVITY PRIMARILY OVER THE INTERIOR POSSIBLY
PUSHING TOWARD THE COAST LATE IN THE DAY. EAST TO SOUTHEAST FLOW
SATURDAY AND SUNDAY WILL HOLD THE WEST COAST SEA BREEZE OVER THE
COASTAL COUNTIES WHICH WILL BE THE FOCUS FOR AFTERNOON
THUNDERSTORMS...MOST NUMEROUS AS THE EAST COAST SEA BREEZE
COLLIDES WITH THE WEST COAST SEA BREEZE DURING THE LATE AFTERNOON
EACH DAY. DAYTIME TEMPERATURES WILL RUN NEAR CLIMATIC NORMALS
THURSDAY...THEN A FEW DEGREES ABOVE NORMAL FRIDAY THROUGH THE
WEEKEND AS WINDS SHIFT TO THE EAST-SOUTHEAST.
&&
.AVIATION...
AS WINDS SHIFT TO SW AND WEST ISOLD TSRA NOW FORMING WILL MOVE
INLAND AS THEY BECOME SCT. STILL LOOKING FOR VCNTY TSRA/CB ONLY
INLAND AND SOUTH DURING THIS AFTERNOON. SOUTHERN TERMINALS COULD SEE
ISOLD SHRA IN A 01Z-06Z WINDOW. WINDS BECOME VARIABLE OR LIGHT SE
OVERNIGHT.
&&
.MARINE...
THE SUBTROPICAL RIDGE AXIS WILL REMAIN IN PLACE OVER THE EASTERN
GULF OF MEXICO FOR THE NEXT SEVERAL DAYS. WINDS WILL GENERALLY BE
LIGHT WITH THE EXCEPTION OF SOME STEADIER ONSHORE FLOW DURING THE
AFTERNOON AND EVENING WITH SEA BREEZE DEVELOPMENT.
&&
.FIRE WEATHER...
HIGH PRESSURE WILL DOMINATE THE WEATHER ACROSS THE
FLORIDA PENINSULA THROUGH THE NEXT SEVERAL DAYS. A TYPICAL
SUMMER PATTERN WITH ABUNDANT LOW LEVEL MOISTURE SHOULD HELP PREVENT
ANY CRITICAL LEVELS OF RELATIVE HUMIDITY. MAXIMUM DAILY HEAT INDICES
WILL BE ELEVATED WITH TYPICAL VALUES OF 98 TO 104 DEGREES COMMON.
FOG POTENTIAL...PATCHY INLAND FOG IS EXPECTED THE NEXT COUPLE OF
NIGHTS...ESPECIALLY FOR THOSE LOCATIONS THAT RECEIVE SIGNIFICANT
LATE AFTERNOON OR EVENING RAINFALL FROM DAILY THUNDERSTORMS.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 76 93 77 92 / 10 20 10 20
FMY 76 93 76 93 / 30 40 20 40
GIF 74 94 74 93 / 40 40 20 40
SRQ 75 90 76 90 / 10 20 10 20
BKV 70 93 72 93 / 10 20 10 20
SPG 79 91 79 91 / 10 20 10 20
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/MARINE/FIRE WX...MROCZKA
AVIATION...RUDE
LONG TERM...JELSEMA
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
214 PM EDT MON JUN 17 2013
.SYNOPSIS...
HIGH PRESSURE OFF THE SOUTHEAST COAST HAS SHIFTED FARTHER EASTWARD
AHEAD OF A WEAK FRONTAL ZONE MOVING SOUTHWARD AND INTO THE FORECAST
AREA. THE FRONT AND ASSOCIATED MOISTURE WILL DOMINATE THE FORECAST
AREA/S WEATHER THROUGH MUCH OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
THIS AFTERNOON...A WEAK SHORT WAVE WILL MOVE EASTWARD THROUGH
THE REGION THIS AFTERNOON. THIS MAY HELP TO TRIGGER SOME CONVECTIVE
ACTIVITY BUT EXPECT MAINLY JUST SCATTERED. A WEAKLY SHEARED
ENVIRONMENT WITH JUST MARGINAL LIS -2/-3...TOTALS 44/45 AND CAPES
LESS THAN 1000 J/KG. SOME HEAVY RAIN POSSIBLE IN SHOWERS AND
THUNDERSTORMS WITH PWAT AROUND 1.90 INCHES. SIX HOUR QPF VALUES
AROUND 0.10 OF AN INCH OR LESS. SO NOT MUCH FLOODING POTENTIAL
EXPECTED. AND LATEST SATELLITE PCPN ESTIMATE KEEPS FLOODING
POTENTIAL TO THE NORTH AND WEST IN THE LATEST SPENES.
TONIGHT...MAINLY DIURNAL ACTIVITY BUT NAM BRINGS ANOTHER WEAK
IMPULSE TO THE REGION LATE TONIGHT AFTER MIDNIGHT. SO...PLAN ON
KEEPING AT LEAST SOME LOW CHANCE...SAY AROUND 30 PERCENT AFTER
MIDNIGHT. OTHERWISE...EXPECT LOW TEMPERATURES MAINLY IN THE
LOWER 70S.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
LINGERING MOISTURE ASSOCIATED WITH AN EAST-WEST ORIENTED FRONT WILL
CONTINUE TO AFFECT THE REGION. THE MODELS KEEP BROAD UPPER-LEVEL
TROUGH WITH A SERIES OF SHORTWAVES MOVING THROUGH THE FLOW OVER THE
FORECAST AREA. THIS WILL CONTINUE THE CHANCE FOR SHOWER AND
THUNDERSTORM DEVELOPMENT TUESDAY AND TUESDAY NIGHT AND INTO
WEDNESDAY. KEPT TEMPERATURES BELOW GUIDANCE WITH THE EXPECTED RAIN
AND CLOUDINESS.
&&
.LONG TERM /THURSDAY THRU MONDAY/...
SURFACE HIGH PRESSURE BEGINS TO BUILD DOWN INTO THE CAROLINAS ON
THURSDAY AND THE CHANCE OF SHOWERS AND THUNDERSTORMS LESSENS INTO
THE WEEKEND BUT THERE REMAINS ENOUGH MOISTURE FOR POSSIBLE AFTERNOON
SHOWERS AND THUNDERSTORMS. EXPECT HIGH TEMPERATURES NEAR OR A LITTLE
BELOW CLIMATOLOGY.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
ONE SHORT WAVE MOVED EAST THIS MORNING BUT RUC13 BRINGS ANOTHER
WEAK SHORT OVER THE REGION LATE THIS AFTERNOON ON INTO THE EVENING
HOURS. THIS MAY HELP TO GENERATE MORE SHOWERS AND THUNDERSTORMS
BUT FOR TIME BEING WILL JUST MENTION THUNDERSTORMS IN THE VICINITY
22Z-02Z ALL TAF SITES. MAINLY VFR CONDITIONS THIS AFTERNOON AND
EVENING EXCEPT IF CONVECTIVE ACTIVITY DEVELOPS...MAY SEE BRIEF
IFR-MVFR CONDITIONS. OVERNIGHT...WITH PLENTY OF LOW LEVEL MOISTURE
AND LOW LEVEL WINDS BELOW 1 KFT SOUTHWEST 12-15 KNOTS...STRATUS
IS A POSSIBILITY. MVFR CIGS OCCURRED THIS MORNING AT AGS...DNL AND
OGB AND MVFR CIGS NEAR 2 KFT ARE EXPECTED AGAIN TUESDAY MORNING
AROUND 10Z-13Z TIME FRAME. AFTER 13Z...MAINLY VFR CONDITIONS JUST
LIKE TODAY BUT ANOTHER WEAK IMPULSE MOVES THROUGH TUESDAY AFTERNOON
JUST LIKE TODAY AND MORE SHOWERS AND THUNDERSTORMS ARE POSSIBLE.
HOWEVER...WILL NOT INCLUDE IN TAF SITES DUE TO UNCERTAINTY AS TO
TIMING AND LOCATION.
EXTENDED AVIATION OUTLOOK...CHANCE OF MAINLY AFTERNOON/EVENING
THUNDERSTORMS. CHANCE OF LATE NIGHT/EARLY MORNING FOG/STRATUS.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
158 PM EDT MON JUN 17 2013
.SYNOPSIS...
HIGH PRESSURE OFF THE SOUTHEAST COAST HAS SHIFTED FARTHER EASTWARD
AHEAD OF A WEAK FRONTAL ZONE MOVING SOUTHWARD AND INTO THE FORECAST
AREA. THE FRONT AND ASSOCIATED MOISTURE WILL DOMINATE THE FORECAST
AREA/S WEATHER THROUGH MUCH OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
THIS AFTERNOON...A WEAK SHORT WAVE WILL MOVE EASTWARD THROUGH
THE REGION THIS AFTERNOON. THIS MAY HELP TO TRIGGER SOME CONVECTIVE
ACTIVITY BUT EXPECT MAINLY JUST SCATTERED. A WEAKLY SHEARED
ENVIRONMENT WITH JUST MARGINAL LIS -2/-3...TOTALS 44/45 AND CAPES
LESS THAN 1000 J/KG. SOME HEAVY RAIN POSSIBLE IN SHOWERS AND
THUNDERSTORMS WITH PWAT AROUND 1.90 INCHES. SIX HOUR QPF VALUES
AROUND 0.10 OF AN INCH OR LESS. SO NOT MUCH FLOODING POTENTIAL
EXPECTED. AND LATEST SATELLITE PCPN ESTIMATE KEEPS FLOODING
POTENTIAL TO THE NORTH AND WEST IN THE LATEST SPENES.
TONIGHT...MAINLY DIURNAL ACTIVITY BUT NAM BRINGS ANOTHER WEAK
IMPULSE TO THE REGION LATE TONIGHT AFTER MIDNIGHT. SO...PLAN ON
KEEPING AT LEAST SOME LOW CHANCE...SAY AROUND 30 PERCENT AFTER
MIDNIGHT. OTHERWISE...EXPECT LOW TEMPERATURES MAINLY IN THE
LOWER 70S.
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
HIGH MOISTURE ASSOCIATED WITH THE DIFFUSE EAST-WEST ORIENTED FRONT
WILL CONTINUE. THE MODELS KEEP BROAD UPPER-LEVEL TROUGHING WITH A
SERIES OF SHORTWAVE TROUGHS MOVING THROUGH THE FLOW OVER THE
FORECAST AREA. EXPECT NUMEROUS SHOWERS AND THUNDERSTORMS. LEANED
TOWARD THE HIGHER GUIDANCE POPS. THE COOLER HIGH TEMPERATURE
GUIDANCE APPEARS BETTER BECAUSE OF EXPECTED CLOUDINESS. THE LOW
TEMPERATURE GUIDANCE WAS CONSISTENT.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
THE GFS AND ECMWF DISPLAY THE FRONT REMAINING NEAR THE FORECAST
AREA THROUGH THE MEDIUM-RANGE PERIOD. THERE HAS BEEN INCONSISTENCY
IN THE PLACEMENT OF DEEPER MOISTURE. THE GFS ENSEMBLE MEANS AND
OPERATIONAL GFS MOS SUPPORT CHANCE POPS THROUGH THE PERIOD.
EXPECT HIGH TEMPERATURES NEAR OR A LITTLE BELOW CLIMATOLOGY.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
ONE SHORT WAVE MOVED EAST THIS MORNING BUT RUC13 BRINGS ANOTHER
WEAK SHORT OVER THE REGION LATE THIS AFTERNOON ON INTO THE EVENING
HOURS. THIS MAY HELP TO GENERATE MORE SHOWERS AND THUNDERSTORMS
BUT FOR TIME BEING WILL JUST MENTION THUNDERSTORMS IN THE VICINITY
22Z-02Z ALL TAF SITES. MAINLY VFR CONDITIONS THIS AFTERNOON AND
EVENING EXCEPT IF CONVECTIVE ACTIVITY DEVELOPS...MAY SEE BRIEF
IFR-MVFR CONDITIONS. OVERNIGHT...WITH PLENTY OF LOW LEVEL MOISTURE
AND LOW LEVEL WINDS BELOW 1 KFT SOUTHWEST 12-15 KNOTS...STRATUS
IS A POSSIBILITY. MVFR CIGS OCCURRED THIS MORNING AT AGS...DNL AND
OGB AND MVFR CIGS NEAR 2 KFT ARE EXPECTED AGAIN TUESDAY MORNING
AROUND 10Z-13Z TIME FRAME. AFTER 13Z...MAINLY VFR CONDITIONS JUST
LIKE TODAY BUT ANOTHER WEAK IMPULSE MOVES THROUGH TUESDAY AFTERNOON
JUST LIKE TODAY AND MORE SHOWERS AND THUNDERSTORMS ARE POSSIBLE.
HOWEVER...WILL NOT INCLUDE IN TAF SITES DUE TO UNCERTAINTY AS TO
TIMING AND LOCATION.
EXTENDED AVIATION OUTLOOK...CHANCE OF MAINLY AFTERNOON/EVENING
THUNDERSTORMS. CHANCE OF LATE NIGHT/EARLY MORNING FOG/STRATUS.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1208 PM CDT MON JUN 17 2013
.DISCUSSION...
ISSUED 1010 AM CDT MON JUN 17 2013
EARLY MORNING FOG HAS LARGELY LIFTED...WITH JUST A BIT OF HAZE
LINGERING NEAR THE INDIANA BORDER. LARGE CIRRUS SHIELD SPREADING
OVER MOST OF THE FORECAST AREA...ALTHOUGH A BAND OF ALTOCUMULUS IS
ALONG THE I-70 CORRIDOR. THIS IS IN THE SAME GENERAL AREA AS A
WEAK SURFACE BOUNDARY...AND IS THE MOST LIKELY LOCATION FOR ANY
CONVECTION TO DEVELOP...MAINLY DURING THE AFTERNOON HOURS. WITH A
BROAD POOL OF DEW POINTS NEAR 70 ALONG THE I-72 CORRIDOR...
SCATTERED STORMS ARE ALSO POSSIBLE THERE WITH THE BOUNDARY NOT TOO
FAR AWAY...BUT THEY SHOULD NOT BE THAT ORGANIZED. ANOTHER BOUNDARY
DROPPING INTO THE NORTHWEST PART OF THE FORECAST AREA MAY ALSO
TRIGGER A COUPLE SHOWERS/STORMS THIS AFTERNOON AS WELL IN THAT
AREA.
HAVE SENT SOME UPDATED ZONES/GRIDS...MAINLY TO UPDATE THE
PRECIPITATION TRENDS.
GEELHART
&&
.AVIATION...
ISSUED 1204 PM CDT MON JUN 17 2013
MAIN CONCERN WITH 18Z TAF SET INVOLVES POTENTIAL FOR POP-UP
CONVECTION. MIDDAY SURFACE MAP SHOWS A COUPLE WEAK BOUNDARIES OVER
CENTRAL ILLINOIS AND LATEST VISIBLE SATELLITE SHOWING CUMULUS
STARTING TO DEVELOP ALONG THEM. THE BOUNDARIES SHOULD NOT MOVE
MUCH DURING THE AFTERNOON...BUT DRIER AIR IS SPREADING SOUTHWARD
TOWARD THEM. THUS...AM THINKING THAT ONLY KSPI/KDEC/KCMI MAY SEE A
THREAT OF THUNDER THIS AFTERNOON...AS THEY ARE CLOSEST TO THE
BOUNDARY. COVERAGE CURRENTLY NOT EXPECTED TO BE ENOUGH TO WARRANT
MORE THAN A VCTS MENTION AT THESE SITES. ANY THUNDER NEAR THE TAF
SITES SHOULD FADE WITH SUNSET. LATE IN THE PERIOD...MAY SEE SOME
MVFR CONDITIONS AT TIMES JUST BEFORE SUNRISE...BUT DO NOT THINK IT
WILL GET AS WIDESPREAD OR DENSE AS THIS MORNING...DUE TO HIGHER
RANGES BETWEEN TEMPERATURE AND DEW POINT.
GEELHART
&&
.PREV DISCUSSION...
ISSUED 252 AM CDT MON JUN 17 2013
SHORT TERM...TODAY THROUGH WEDNESDAY
VERY WEAK SURFACE BOUNDARY EXTENDING ACROSS SOUTH-CENTRAL ILLINOIS
WILL BE THE PRIMARY FOCUSING MECHANISM FOR SCATTERED THUNDERSTORMS
TODAY. WITH ONE UPPER-WAVE PASSING WELL TO THE NORTH ACROSS THE
GREAT LAKES AND ANOTHER TRACKING TO THE S/SW INTO THE LOWER OHIO
RIVER VALLEY...VERY LITTLE UPPER SUPPORT WILL BE IN PLACE FOR
WIDESPREAD CONVECTION ACROSS CENTRAL ILLINOIS. DESPITE LACK OF
UPPER DYNAMICS...VERY MOIST AIR MASS IN PRESENCE OF WEAK SURFACE
FORCING WILL BE ENOUGH TO TRIGGER A FEW SHOWERS/THUNDERSTORMS
LATER TODAY. HRRR SUGGESTS DEVELOPMENT AROUND MIDDAY...ESPECIALLY
IN CLOSER PROXIMITY TO BOUNDARY. WILL THEREFORE INCLUDE LOW CHANCE
POPS TODAY...WITH BEST RAIN CHANCES SOUTH OF I-72.
SHORT-WAVE TROUGH CURRENTLY EVIDENT ON WATER VAPOR IMAGERY OVER
SOUTHERN SASKATCHEWAN MAY PROVIDE A NEW WRINKLE IN THE FORECAST
FOR TUESDAY. WHILE WE PREVIOUSLY THOUGHT TUESDAY WOULD BE
DRY...LATEST MODEL GUIDANCE IS INDICATING THE POTENTIAL FOR
ISOLATED CONVECTION DURING THE AFTERNOON. THANKS TO A CONTINUED
MOIST AIR MASS AND THE ARRIVAL OF MODEST UPPER FORCING DURING PEAK
HEATING...HAVE INCLUDED A SLIGHT CHANCE FOR THUNDER TUESDAY
AFTERNOON. ONCE THE WAVE PUSHES FURTHER EAST...SURFACE HIGH
PRESSURE WILL BUILD INTO THE REGION FOR TUESDAY NIGHT AND
WEDNESDAY...PROVIDING SEASONABLY WARM AND DRY CONDITIONS.
LONG TERM...THURSDAY THROUGH SUNDAY
00Z 17 JUN MODELS CONTINUE TO SUGGEST A VERY WARM AND LARGELY DRY
EXTENDED FORECAST. ALL MODELS BUILD AN UPPER-LEVEL RIDGE ACROSS
THE PLAINS ON THURSDAY...THEN SHIFT IT INTO THE MIDWEST OVER THE
WEEKEND. PREVIOUS RUNS DISAGREED ON THE EXACT STRENGTH/POSITIONING
OF THE RIDGE...WHICH BROUGHT INTO QUESTION WHETHER ANY MCS
ACTIVITY COULD RIDE UP/OVER THE RIDGE INTO THE AREA DURING THE
PERIOD. LATEST GFS/ECMWF/GEM ARE ALL LOOKING STRONGER WITH THE
RIDGING...KEEPING BEST FORCING FOR NOCTURNAL MCS DEVELOPMENT
FURTHER NORTH ACROSS THE UPPER MIDWEST INTO THE GREAT LAKES. MODELS
INDICATE ONE CONVECTIVE COMPLEX MAY BRUSH THE KILX CWA TO THE
NORTH FRIDAY NIGHT...BEFORE RIDGE BUILDS EVEN FURTHER ON SATURDAY.
HAVE THEREFORE INCLUDED CHANCE POPS ALONG AND NORTH OF A CANTON TO
BLOOMINGTON LINE FRIDAY NIGHT...BUT HAVE GONE WITH A DRY FORECAST
ACROSS THE BOARD FOR THE REMAINDER OF THE EXTENDED. WILL LIKELY
HAVE TO WAIT UNTIL RIDGE BEGINS TO FLATTEN EARLY NEXT WEEK BEFORE
ANY WIDESPREAD RAIN CHANCES RETURN TO THE AREA. GIVEN BUILDING
UPPER HEIGHTS AND LACK OF CONVECTION...HIGH TEMPERATURES WILL
REACH THE UPPER 80S/LOWER 90S WHILE OVERNIGHT LOWS ONLY DROP INTO
THE LOWER 70S FRIDAY THROUGH SUNDAY.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
245 PM MDT MON JUN 17 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 245 PM MDT MON JUN 17 2013
EARLY AFTERNOON WV IMAGERY AND RAP H5 ANALYSIS SHOW NW FLOW OVER
CWA WITH H5 RIDGE ACROSS WESTERN US. AT THE SURFACE A FRONT
CURRENTLY...WITH AREA OF SURFACE CONVERGENCE JUST WEST OUR OUR CWA
WHERE ISOLATED THUNDERSTORMS ARE BEGGING TO INTENSIFY.
LATEST RAP ANALYSIS INDICATES MIXED LAYER CAPE IN EXCESS OF 1500
J/KG OVER OUR CWA AND SHOWS THIS INCREASING AS LAPSE RATES
CONTINUE TO STEEPEN. LATEST HRRR SHOWS THUNDERSTORM ACTIVITY OVER
EASTERN COLORADO EXPANDING IN COVERAGE AND MOVING EAST THROUGH THE
AFTERNOON. NAM CONTINUES TO SHOW WIDESPREAD CONVECTIVELY INDUCED QPF
IN PLACE THROUGH THE EVENING OVERSPREADING THE CWA AND THEN
LINGERING OVERNIGHT AS A SHORTWAVE TROUGH UPSTREAM PUSHES SOUTH.
GFS/SREF SHOW A SIMILAR PATTERN...THOUGH QPF AMOUNTS ARE NOT QUITE
AS HIGH. SHEER PROFILES SHOULD IMPROVE THROUGH THE
AFTERNOON/EVENING WITH 0-6KM BULK SHEER 30-40KT...WHICH SHOULD
SUPPORT SEVERE THUNDERSTORMS. EARLY ON THIS AFTERNOON/EVENING
TORNADOES MAY BE POSSIBLE WITH STEEP LAPSE RATES IN PROXIMITY TO
SURFACE BOUNDARY/THUNDERSTORM INTERACTIONS. AIR MASS CONTINUES TO
BE VERY MOIST...AND CONSIDERING THE VERY SLOW STORM MOTION (5-10KT
0-6KM MEAN WIND) WE COULD SEE ISOLATED FLASH FLOOD RISK WITH THIS
ACTIVITY. AT THE VERY LEAST MOST LOCATIONS COULD SEE WIDESPREAD
0.5 TO 1.00" RAINFALL.
CURRENTLY THINKING WE SHOULD SEE AFTERNOON THUNDERSTORM ACTIVITY
MERGING INTO AT LEAST ONE CLUSTER/LINE AND SPREAD EAST THROUGH THE
EVENING...BEFORE ADDITIONAL ACTIVITY DEVELOPS WITH OVERNIGHT
SHORTWAVE. I ONLY MADE MINOR CHANGES TO INHERITED POP FORECAST
WITH MAIN CHANGE TO END THUNDERSTORM CHANCES EARLY TUE MORNING AS
WE SHOULD BE SUBSIDENT ON BACK SIDE OF DEPARTING PV ANOMALY.
GUIDANCE SUPPORTS THUNDERSTORMS REDEVELOPING BY WED AFTERNOON FROM
THE WEST TO THE EAST.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 210 PM MDT MON JUN 17 2013
A RIDGE WILL MOVE INTO THE PLAINS AND REMAIN THROUGH THURSDAY.
SURFACE HIGH PRESSURE WILL BE OVER THE CENTRAL PLAINS TUESDAY NIGHT.
LOW PRESSURE OVER WYOMING WEDNESDAY WILL DEVELOP SOUTH INTO EASTERN
COLORADO WEDNESDAY NIGHT. BY THURSDAY A TROUGH WILL BE POSITIONED
OVER NORTHWEST KANSAS,
STORMS WILL LIKELY FORM OVER EASTERN COLORADO EACH AFTERNOON
THROUGH WEDNESDAY DUE TO CONVERGENCE AND PROXIMITY TO THE SURFACE
TROUGH. MOISTURE AND INSTABILITY WILL BE FOCUSED IN THAT AREA.
PLAN TO GO WITH CHANCE POPS IN THAT AREA AND TO THE EAST WHERE
STEERING WINDS WILL MOVE THE STORMS. GENERALLY LOWER POPS WILL BE
USED IN THE EASTERN FA. THE TROUGH SHOULD BE EAST OF THE FA
THURSDAY SO PLAN TO CONTINUE THE DRY FORECAST/NIL POPS FOR THAT
PERIOD.
MIN TEMPERATURES TUESDAY AND WEDNESDAY NIGHTS WILL BE IN THE LOWER
TO MID 60S. MAX TEMPERATURES WEDNESDAY WILL REACH THE MID/UPPER 80S.
850 TEMPERATURES AROUND 30 WILL SUPPORT MID 90S FOR MAX TEMPERATURES
THURSDAY.
IN THE EXTENDED...(THURSDAY NIGHT THROUGH MONDAY)...UPPER FLOW WILL
BE SOUTHWEST THROUGH THIS PART OF THE FORECAST. A SURFACE TROUGH
WILL BE NEAR THE COLORADO BORDER AS WELL. IMPULSES MOVING THROUGH
THE FLOW WILL PRODUCE AT LEAST A SLIGHT CHANCE OF THUNDERSTORMS FROM
FRIDAY NIGHT THROUGH SUNDAY NIGHT. THE FORECAST WILL BE DRY WITH NIL
POPS THURSDAY NIGHT AND MONDAY.
MIN TEMPERATURES WILL RANGE FROM THE LOWER TO MID 60S WEST TO THE
UPPER 60S TO 70 EAST. MAX TEMPERATURES WILL RANGE IN THE 90S WITH
SOME UPPER 80S WEST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1144 AM MDT MON JUN 17 2013
PRIMARY AVIATION CONCERN THROUGH MOST OF THE TAF PERIOD WILL BE
POSSIBILITY OF STRONG THUNDERSTORMS AT BOTH KGLD AND KCMK
TERMINALS. CURRENTLY EXPECT ACTIVITY TO DEVELOP ACROSS EASTERN
COLORADO AND SPREAD EASTWARD THIS AFTERNOON...WITH ISOLATED
THUNDERSTORMS POSSIBLY DEVELOPING WITHIN VICINITY OF BOTH
TERMINALS EARLIER. BETTER CONFIDENCE IS AFTER 20Z WHEN I HAVE VCTS
GROUP. I AM NOT SURE IF CONDITIONS WILL PREVAIL THOUGH THIS IS A
POSSIBILITY IF A LARGE SLOW MOVING COMPLEX OF THUNDERSTORMS MOVES
OVER EITHER TERMINAL. I KEPT TEMPO GROUPS FOR NOW...AND WILL NEED
TO MONITOR/AMEND AS THE SITUATION EVOLVES. SOME GUIDANCE KEEPS
THUNDERSTORMS LINGERING MOST OF THE NIGHT...AND WHILE I COULDNT
RULE THIS OUT CONFIDENCE IS TOO LOW TO CARRY MENTION PAST 08Z
(ESPECIALLY AT KMCK).
WITH VERY MOIST AIRMASS IN PLACE...AND POSSIBLE INTRODUCTION OF
ADDITIONAL MOISTURE FROM THUNDERSTORMS WE COULD SEE FOG/STRATUS
DEVELOPMENT AFTER 09Z AT BOTH TERMINALS. IF THUNDERSTORMS LINGER
THIS LIKELY WONT BE THE CASE...SO I KEPT MVFR MENTION AT BOTH
TERMINALS IMPROVING AFTER DAYBREAK. A LOT CAN CHANGE WITH THIS
PATTERN DUE TO TIMING/EVOLUTION OF THUNDERSTORM ACTIVITY.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...FS
AVIATION...DR
AREA FORECAST DISCUSSION
NWS PADUCAH KY
253 PM CDT MON JUN 17 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 242 PM CDT MON JUN 17 2013
MID LVL SHORT WAVE DRIFTING SLOWLY EWD THROUGH MO WILL CONTINUE TO
SPAWN SCAT TO NUMEROUS SHOWER/THUNDERSTORM ACTIVITY THIS EVENING
AND OVERNIGHT AS A SURFACE WAVE FORMS OVER AR AND DRIFTS EAST INTO
TN. THIS SHORT WAVE AND SFC FEATURE WILL BE QUITE SLOW TO MOVE
THIS EVENING INTO THE OVERNIGHT HOURS. THUS...LOCALLY HEAVY
RAINFALL REMAINS A POSSIBILITY. THUNDERSTORM CLUSTERS MAY ACTUALLY
PROPAGATE FROM SE TO NW OVER THE SAME LOCATIONS AT TIMES. AS THE
NIGHT PROGRESSES...THE GREATEST HEAVY RAIN THREAT SHOULD SHRINK TO
OUR S/SE AREAS...CLOSEST TO THE SFC BOUNDARY.
ANOTHER MID LVL SHORT WAVE WILL MOVE SE TOWARD THE REGION ON
TUESDAY. HOWEVER...THIS WAVE SHOULD BE MUCH MORE MOISTURE STARVED
WITH LITTLE OR NO LOW LEVEL FORCING /SFC BOUNDARY/. THUS...NOT
EXPECTING NEAR THE COVERAGE OR INTENSITY OF PRECIPITATION ON
TUESDAY THAT HAS BEEN EXPERIENCED TODAY.
HIGH PRESSURE AND DRIER CONDITIONS WILL BECOME MUCH MORE ESTABLISHED
BY THE MID WEEK TIME FRAME AND TEMPS SHOULD REMAIN CLOSE TO
SEASONAL NORMS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 242 PM CDT MON JUN 17 2013
CONFIDENCE CONTINUES TO INCREASE ON A GENERALLY RAINFREE...YET
WARMING TIME PERIOD.
MID LVL RIDGING OVER THE SOUTHERN AND CENTRAL PLAINS DURING THE
LATTER PART OF THE WORK WEEK WILL EVENTUALLY MIGRATE EASTWARD INTO
THE MISSISSIPPI RIVER VALLEY BY SAT. THIS WILL MOST LIKELY LEAD TO A
RAINFREE PERIOD RIGHT THROUGH THE WEEKEND. HOWEVER...AS THE RIDGE
SHIFTS CLOSER TO US...ESPECIALLY NEXT WEEKEND...WE WILL UNDERGO A
NOTICEABLE RETURN TO HEAT AND HUMIDITY. EXPECT HIGH TEMPS INTO THE
LOWER 90S NEXT WEEKEND...WITH HEAT INDICES LIKELY TOPPING OUT NEAR
THE CENTURY MARK BOTH DAYS.
&&
.AVIATION...
ISSUED AT 1230 PM CDT MON JUN 17 2013
VFR CIGS/VSBYS THROUGH MOST OF THE 18Z TAF PERIOD. HRRR MESOSCALE
MODEL HAS HAD A GOOD OVERALL HANDLE ON CONVECTIVE TRENDS THIS
MORNING...SO HAVE CHOSEN TO FOLLOW THAT SOLUTION INTO THE
AFTERNOON AND EARLY EVENING. BEST CHC FOR TSTMS WILL BE OVER
KCGI/KPAH THIS AFTERNOON...POSSIBLY AFFECTING KEVV 21Z-02Z FRAME.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
SHORT TERM...MEFFERT
LONG TERM...MEFFERT
AVIATION...MEFFERT
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1225 PM CDT MON JUN 17 2013
.UPDATE...
ISSUED AT 1219 PM CDT MON JUN 17 2013
FOR AVIATION SECTION ONLY.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 324 AM CDT MON JUN 17 2013
SHORT TERM WEATHER SOLUTION CONTINUES TO BE RATHER UNCLEAR MAINLY
DUE TO MODEL DISCREPANCIES. SYNOPTICALLY SPEAKING...AT THE SURFACE
THERE IS AN E-W STATIONARY FRONTAL BOUNDARY TO THE NORTH OF OUR
CWA...WE HAVE A WEST NORTHWEST FLOW ALOFT WITH MULTIPLE RIPPLES OF
ENERGY UPSTREAM...AND SOUTHERLY FLOW AT THE SURFACE HAS BROUGHT
DECENT LOW LEVEL MOISTURE ACROSS THE REGION.
AS A RESULT...PRECIP CHANCES SHOULD INCREASE FROM THE WEST TODAY AS
THE H5 ENERGY TAPS INTO THE MOISTURE AT HAND. PRECIP CHANCES SHOULD
PEAK AREA WIDE THIS AFTERNOON AND EVENING AS THE MAIN SHORT WAVE
PULLS THE AFOREMENTIONED FRONTAL BOUNDARY TOWARD THE REGION. MODELS
APPEAR TO WASH FRONTAL BOUNDARY OUT AS IT APPROACHES...SO ITS HARD
TO SAY WHEN OR IF WE WILL HAVE A FROPA. EITHER WAY...PRECIP
CHANCES START TO TAPER OFF FROM THE WEST LATE TONIGHT INTO TUESDAY.
HOWEVER...WITH ANOTHER SHORT WAVE FORECAST TO DIVE SOUTHEAST ACROSS
THE REGION ON TUESDAY COMBINED WITH RESIDUAL MOISTURE...MODELS ARE
CRANKING OUT A SMATTERING OF QPF ACROSS ALL OF THE REGION...SO
DECIDED TO KEEP POPS ACROSS THE ENTIRE CWA. TUESDAY NIGHT SURFACE
HIGH PRESSURE WILL BEGIN TO OVERSPREAD THE REGION.
TEMPERATURES WILL REMAIN CLOSE TO NORMAL THROUGH THE SHORT TERM
PERIOD.
.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 324 AM CDT MON JUN 17 2013
CONFIDENCE HAS INCREASED FOR THE WORK WEEK...BUT DECREASES FOR THE
WEEKEND.
THE RIDGING ALOFT OVER THE PLAINS HAS MIGRATED EASTWARD MORE INTO
THE MID MISSISSIPPI VALLEY. THUS MITIGATING POPS FOR THE WEEK AND
PUT THE WARM FRONT PASSAGE OFF UNTIL THE WEEKEND WHICH ORIGINALLY
WAS PROGGED FOR THURSDAY TWO DAYS PAST. THIS IS THE REASON FOR THE
INCREASE CONFIDENCE IN THE WORK WEEK AND DECREASED CERTAINTY FOR THE
WEEKEND. CONSIDERING THE AFOREMENTIONED OPTED TO LEAVE THE FORECAST
DRY. IN ADDITION...FORECAST SOUNDINGS CONTINUE TO INDICATE
SIGNIFICANTLY DRIER AIR IN PLACE FOR THE ENTIRE RUN AS HAS BEEN THE
CASE FOR THE PAST FOUR OR FIVE DAYS. THIS WOULD PROBABLY ACCOUNT FOR
THE DECREASE IN COVERAGE AND INTENSITY SCHEDULED FOR TODAY WHICH
FURTHER SUPPORTS THE EXTENDED STRATEGY. ONE THINGS THAT HAS REMAINED
CONSTANT IS THE WARMING TREND ANTICIPATED AFTER FROPA TODAY AND WE
CONTINUE TO EMBRACE THIS TREND WITH TEMPS HEADING TOWARD THE 90S AS
THE WEEKEND APPROACHES.
&&
.AVIATION...
ISSUED AT 639 AM CDT MON JUN 17 2013
VFR CIGS/VSBYS THROUGH MOST OF THE 18Z TAF PERIOD. HRRR MESOSCALE
MODEL HAS HAD A GOOD OVERALL HANDLE ON CONVECTIVE TRENDS THIS
MORNING...SO HAVE CHOSEN TO FOLLOW THAT SOLUTION INTO THE
AFTERNOON AND EARLY EVENING. BEST CHC FOR TSTMS WILL BE OVER
KCGI/KPAH THIS AFTERNOON...POSSIBLY AFFECTING KEVV 21Z-02Z FRAME.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...GM
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1225 PM EDT MON JUN 17 2013
.SYNOPSIS...
LOW PRESSURE WILL CROSS THE REGION TODAY BRINGING A COLD FRONT
ACROSS THE AREA BY TONIGHT. A SECOND COLD FRONT IS EXPECTED TO
CROSS THE REGION ON TUESDAY WITH COOLER AIR TUESDAY NIGHT INTO
WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
1225 PM...CONVECTION IS BEGINNING TO FIRE OFF ACROSS NRN NY STATE
EAST INTO SW MAINE. THE LATEST MESOSCALE ANALYSIS INDICATES A
STRONG THETA-E RIDGE ACROSS DOWNEAST MAINE WHERE THERE WAS STRONG
SOLAR HEATING THIS MORNING. MUCAPE VALUES ARE AROUND 500-1000 J/KG
ACROSS DOWNEAST MAINE AS OF NOON. THE THINKING REMAINS THAT
CONVECTION WILL INITIATE ACROSS THE CENTRAL HIGHLANDS AND MOVE
ACROSS INTERIOR DOWNEAST MAINE THIS AFTERNOON. AT THIS TIME ONLY
PLANNING TO MAKE SOME MINOR TWEAKS TO THE GRIDS BASED ON THE
LATEST SATELLITE....RADAR...AND OBSERVATIONS.
938 AM UPDATE...LOW PRES IN SRN QUEBEC THIS MORNING IS 125 MILES
NW OF QUEBEC CITY AT 13Z WITH A WARM FRONT EXTENDING FROM THE LOW
AND ACROSS CENTRAL MAINE. THE LOW WILL MOVE EAST WITH THE FRONTAL
BOUNDARY TO SLOWLY LIFT NORTH TODAY AHEAD OF AN APPROACHING COLD
FRONT THAT IS EXPECTED TO MOVE INTO FAR NRN AND WRN MAINE TOWARD
EVENING. THE AIR MASS IN THE WARM SECTOR IS EXPECTED TO BECOME
MARGINALLY UNSTABLE THIS AFTERNOON ACROSS THE CENTRAL HIGHLANDS
AND INTERIOR DOWNEAST WITH SBCAPES OF 700-1200 J/KG. THERE WILL BE
SOME SHORTWAVES THAT GET EJECTED IN THE FLOW AROUND A DEEP UPPER
LOW JUST EAST OF JAMES BAY THAT WILL WORK ACROSS THE AREA. THERE
IS EXPECTED TO BE ENOUGH SHEAR BOTH SPEED AND DIRECTIONAL TO
ENHANCE THE UPDRAFT POTENTIAL AND CAUSE A FEW OF THE STORMS TO
BECOME STRONG/BORDERLINE SEVERE THIS AFTERNOON. THE BIGGEST THREAT
WILL LIKELY BE GUSTY WIND WITH THE POTENTIAL THAT ANY OF THE
STORMS THAT REALLY GET GOING COULD HAVE SOME LARGER HAIL. THE HRRR
HAD AN AREA OF SHOWERS MOVING INTO THE WESTERN MOUNTAINS THIS
MORNING THAT DID NOT MATERIALIZE TO THE EXTENT THE MODEL WAS
SHOWING. THE LATEST HRRR HAS THE MOST CONCENTRATED AREA OF SHOWERS
AND THUNDERSTORMS MID-LATE AFTERNOON INTO THIS EVENING...MAINLY
ACROSS NORTHERN MAINE AND INTERIOR DOWNEAST.
MADE SOME CHANGES TO THE HOURLY TEMPS THIS MORNING AS TEMPS ARE
NOT RISING MUCH IN THE NORTH WHERE THE STRATUS IS THICKER. TEMPS
WERE RAISED A COUPLE OF DEGREES IN THE SOUTH WHERE THERE IS MORE
SUNSHINE. THE HIGH TEMPS WERE RAISED A COUPLE OF DEGREES INTERIOR
DOWNEAST AND KEPT AS IS ACROSS THE NORTH WHERE THE LOW STRATUS
WILL BEGIN TO LIFT BY MIDDAY AND THERE IS STILL THE POTENTIAL THAT
THE MID SHIFTS HIGHS WILL REALIZED. OTHERWISE...JUST SOME MINOR
TWEAKS TO THE POP/SKY GRIDS FOR THE REMAINDER OF THE MORNING.
PREVIOUS DISCUSSION...
PROBLEM OF THE DAY WILL BE POTENTIAL FOR CONVECTION.
630 AM UPDATE:
AREAS OF DENSE FOG SEEN ALONG THE COAST THIS MORNING PER THE BAR
HARBOR METARS AND THIS IS SUPPORTED BY SOME WEBCAMS IN THAT AREA.
LATEST LAPS SOUNDING SHOWED MOISTURE TRAPPED BELOW 950 MBS. PATCHY
FOG THROUGHOUT THE CWA MAINLY IN THE RIVER VALLEYS. THE FOG WILL
BURN OFF AFTER 8AM. LATEST RADAR SHOWED SHOWERS NOW MOVING INTO
NEW BRUNSWICK W/SOME PATCHY DRIZZLE IN SOME LOCALES ACROSS
NORTHERN MAINE THIS MORNING. SHOWERS MOVING INTO WESTERN MAINE
MTNS THIS MORNING WILL MOVE ACROSS THE CENTRAL HIGHLANDS LATER
THIS MORNING. THEREFORE, BACKED DOWN THE PRECIP CHANCES TO
ACROSS THE NORTH AND CARRIED A MENTION OF SCATTERED SHOWERS THIS
MORNING DOWN ACROSS THE CENTRAL HIGHLANDS.
PREVIOUS DISCUSSION...
THINGS ARE EXPECTED TO CHANGE BY EARLY AFTERNOON AS THE FRONTAL
BOUNDARY LIFTS NORTH AND THE CWA GETS INTO A PSEUDO WARM SECTOR
AHEAD OF THE APCHG COLD FRONT. THIS WILL ALLOW FOR DESTABILIZATION
W/SOME SUNSHINE EXPECTED W/TEMPERATURES HITTING UPPER 60S TO LOWER
70S. LLVLS WILL WARM AHEAD OF A PRE-FRONTAL BOUNDARY AID IN LLVL
INSTABILITY. ALOFT, THE AIRMASS WILL BE COLD ENOUGH W/MID LEVEL
TEMPERATURES(700/500MBS) RUNNING -2C/-19C RESPECTIVELY. MDL
SOUNDINGS FROM THE NAM AND GFS SUPPORT POSSIBLE TSTMS EARLY THIS
AFTERNOON ACROSS THE NORTH AND WESTERN AREAS W/SB CAPES OF
600-900J/KG W/THE GFS THE MOST AGGRESSIVE. 0-6KM BULK SHEAR IS
FCST TO BE AROUND 35 KTS. 700-500MB LAPSE RATES FCST TO BE 6.0-6.5
ACROSS THE NORTHERN 1/2 EARLY THIS AFTERNOON AND CLOSE TO 7.0 C/KM
ACROSS THE INTERIOR DOWNEAST BY MID/LATE AFTERNOON. ENOUGH LLVL
MOISTURE IN PLACE W/SOME DRYING IN THE MID LEVELS WILL ADD TO THE
MIX. THEREFORE, DECIDED TO ADD THE MENTION OF SMALL HAIL AND GUSTY
WINDS IN FOR TSTMS ACROSS THE AFOREMENTIONED AREAS. THE ACTION
WILL SHIFT TO THE CENTRAL AND INTERIOR DOWNEAST AREAS THIS
AFTERNOON AND CONTINUE INTO EARLY EVENING AS TEMPERATURES ARE FCST
TO WARM WELL INTO THE 70S AND DEWPOINTS CLIMB TO AROUND 60F. SW
WIND SHIFTING TO THE WEST THIS AFTERNOON WILL ERODE OUT THE STABLE
MARINE LAYER ALLOWING FOR FURTHER DESTABILIZATION. DECIDED TO
CARRY ENHANCED WORDING W/THE TSTMS INCLUDING THE BANGOR AND CALAIS
AREAS AND KEPT THE MENTION OF THUNDER OUT OF THE COAST DUE TO A
SOUTH FLOW HOLDING ON LONGER. QPF WILL BE A CHALLENGE DUE TO THE
EXPECTED CONVECTION. DECIDED ON A BLEND OF THE GEM/NAM12 AND GFS
AND MANUALLY ADJUSTED TO ACCOUNT TO 2 AREAS OF HEAVIER
AMOUNTS(0.25") W/ONE AREA ACROSS THE NORTH AND THE 2ND AREA OVER
THE DOWNEAST REGION.
THINGS WILL WIND DOWN TONIGHT AS THE COLD FRONT CROSSES THE REGION
AS LOW PRES MOVES ACROSS SOUTHERN CANADA. SOME PARTIAL CLEARING IS
EXPECTED AND THIS WILL LEAD TO SOME FOG. ATTM, DECIDED TO STAY W/PATCHY
FOG. THE DAYCREW CAN ASSESS THIS FURTHER W/THE LATER MODEL RUNS. FOLLOWED
THE GEM AND NAM12 FOR TEMPERATURES/DEWPOINTS FOR TONIGHT.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
HIGH PRESSURE IS EXPECTED TO BUILD IN AT THE SURFACE AT THE
BEGINNING OF THIS PERIOD. AT THE SAME TIME AN UPPER LEVEL TROUGH
WILL APPROACH FROM THE WEST AND MOVE ACROSS THE REGION
WEDNESDAY...HOWEVER WITH DRY CONDITIONS WILL KEEP POPS LOW. HAVE
BLENDED THE GFS...SREF...NAM AND ECMWF FOR POP AND QPF GRIDS. WILL
USE A BLEND OF NAM12 AND GMOS FOR WINDS. FOR TEMPERATURE GRIDS WILL
INITIALIZE WITH GMOS AND WILL RAISE MINIMUM TEMPERATURE TWO
DEGREES BASED ON VERIFICATION. HAVE USED THE GEM FOR DEW POINT
GRIDS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
HIGH PRESSURE WILL CONTINUE TO BUILD IN FROM THE WEST AT THE
BEGINNING OF THIS PERIOD THEN CREST OVER THE REGION THURSDAY
MORNING. A COLD FRONT WILL APPROACH FROM THE NORTHWEST THURSDAY
NIGHT AND CROSS THE STATE FRIDAY. A FRONTAL SYSTEM WILL REMAIN
NEAR THE NORTHERN PORTION OF THE STATE LATE SATURDAY THROUGH
TUESDAY. HAVE USED THE GMOS TO INITIALIZE ALL GRIDS. WILL ADJUST
POP AND SKY GRIDS. HAVE ALSO ADJUSTED ALL MINIMUM TEMPERATURES
HIGHER AND TO BETTER FIT THREE HOUR GMOS.
&&
.AVIATION /16Z MONDAY THROUGH FRIDAY/...
NEAR TERM: IFR AT THE NORTHERN TERMNINALS HAS BEEN SLOW TO
LIFT...BUT ALL TERMINALS SHOULD BE AT LEAST MVFR BY 18Z. SCT
TSTMS ARE EXPECTED TO DEVELOP THIS AFTERNOON INTO EARLY EVENING
AFFECTING THE TERMINALS...ESPECIALLY KBGR AND KBHB. STRONG AND
ERRATIC WIND GUSTS AND SMALL WILL BE A CONCERN.
SHORT TERM: EXPECT VFR CONDITIONS TUESDAY THROUGH FRIDAY.
&&
.MARINE...
NEAR TERM: WAVE HEIGHTS ARE RUNNING AROUND 4 FEET AT THE EASTERN
MAINE SHELF THIS MORNING AND SHOULD BUILD TO 4 TO 5 FT BY THIS
EVENING AS A SOUTHERLY FETCH SETS W/A SWELL COMPONENT. WINDS WILL
BE LIGHT AVERAGING SPEEDS OF 10 KTS.
SHORT TERM: FOR WINDS HAVE BLENDED THE NAM12 AND GFS40 AND WILL
USE 125 PERCENT OF THE MODEL BLEND FOR GUST SPEED. FOR WAVES:
EXPECT WINDS ACROSS LOCAL WATERS TO BE LIGHT THROUGH THIS PERIOD
SO LONG PERIOD WAVE WILL DOMINATE. EXPECT SOUTHERLY WAVE GROUP
2-3 FEET/8 SECONDS ACCOMPANIED BY SECONDARY SOUTHEAST GROUP 1-2
FEET/10 SECONDS.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...CB/HEWITT
SHORT TERM...MIGNONE
LONG TERM...MIGNONE
AVIATION...CB/HEWITT/MIGNONE
MARINE...CB/HEWITT/MIGNONE
AREA FORECAST DISCUSSION...UPDATED
NWS PITTSBURGH PA
515 PM EDT MON JUN 17 2013
.SYNOPSIS...
A FRONTAL BOUNDARY WILL REMAIN IN THE VICINITY OF THE UPPER OHIO
VALLEY...MAINTAINING CHANCES FOR SHOWERS AND THUNDERSTORMS THROUGH
THE DAY ON TUESDAY. HIGH PRESSURE WILL MOVE INTO THE REGION FROM
THE NORTHWEST ON WEDNESDAY...PROMOTING GENERALLY DRY AND
SEASONABLE WEATHER THROUGH THURSDAY.
&&
.NEAR TERM /THROUGH TUESDAY/...
FCST UPDATED TO REFLECT ONGOING SVR TSTMS IN ERN OH. HIGHER MSTR
CONTENT HAS PROMOTED STRONGER INSTBY SUCH THAT A FEW TSTMS WERE
ABLE TO STRENGTHEN THRU THE MID-LVL WARM AIR. HAIL AND WIND HAVE
BEEN REPORTED. POPS AND QPF WERE INCRD. OTHERWISE...NO CHGS ATTM.
PREV DISCUSSION FOLLOWS.
AN ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO INCREASE
POPS TO ACCOUNT FOR DEVELOPING UPSTREAM SHOWERS AND THUNDERSTORMS.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A WEAK AND BROAD
CYCLONIC FLOW ACROSS THE UPPER OHIO VALLEY WITH DRIER AND SLIGHTLY
WARMER AIR ADVECTING IN FROM THE WEST. 850MB CONVERGENCE ALONG THE
MASON-DIXON LINE HAS WEAKENED MOSTLY WITH ONLY AN ISOLATED SHOWER
OR TWO REMAINING ACROSS THE ALLEGHENY FRONT. THE CONVERGENCE ZONE
HAS BEEN CO-LOCATED WITH A FRONTAL BOUNDARY NEAR THE MASON-DIXON
LINE. ALTHOUGH A THERMAL GRADIENT IS LACKING ALONG THE BOUNDARY...IT
CAN BE MORE EASILY DEPICTED BY SURFACE DEW POINT AND EQUIVALENT
POTENTIAL TEMPERATURE GRADIENTS. UPSTREAM...SOME LAKE BREEZE
INTERACTION (LAKE ERIE) WITH A SOUTHWESTERLY LOW-LEVEL FLOW HAS
SETUP A CONVERGENCE ZONE OF CONVECTION ACROSS NORTHERN OHIO.
THIS EVENING...THE FRONTAL BOUNDARY WILL REMAIN FAIRLY
STATIONARY IN THE VICINITY OF THE MASON-DIXON LINE. THERE ARE A
FEW CONTRIBUTORS HAT HAVE LED TO THE FORECAST FOR POSSIBLE
CONVECTION INTO THE EVENING. THESE INCLUDE...THE FRONTAL
BOUNDARY AND INSTABILITY INCREASING TO 1500-2500 J/KG SBCAPE
FOR LOCATIONS PRIMARILY SOUTH OF PITTSBURGH. FOR LOCATIONS NORTH
AND WEST OF PITTSBURGH...CHC OF THUNDERSTORMS IS FORECAST WITH
ONGOING DEVELOPING CONVECTION IN NORTHERN OHIO. WITH THIS AND THE 14Z
HRRR IN MIND HAVE GONE WITH SCHC INCREASING TO CHC POP THROUGH
MUCH THE EVENING.
TONIGHT...LINGERING CONVECTION WILL BE ONGOING FROM DIURNAL
ACTIVITY RELATED TO THE SERIES OF BOUNDARIES LOCATED IN THE
VICINITY OF THE FORECAST AREA. WITH THE LOSS OF
HEATING...CONVECTION WILL BEGIN TO DIMINISH ACROSS THE AREA.
HOWEVER...NORTHERN BOUNDARY WILL THEN BEGIN TO DROP SOUTHWARD AS A
FRONT. THUS...THE FORCING PROVIDED FROM THIS FEATURE WILL ALLOW
FOR THE CHC OF SHOWERS AND THUNDERSTORMS TO CONTINUE ACROSS MUCH
OF THE AREA NOCTURNALLY. OVERNIGHT LOWS ARE CLOSER TO THE WARMER
MET...WITH LOWS RANGING FROM THE MID 60S IN EASTERN OHIO...SW
PA...AND NORTHERN WV TO THE UPPER 50S ACROSS THE ALLEGHENY FRONT
AND LAUREL HIGHLANDS.
TUESDAY...THE COLD FRONT WILL CONTINUE TO DROP SLOWLY SOUTHWARD ACROSS
THE AREA...WITH THE COVERAGE OF SHOWER AND THUNDERSTORMS INCREASING
AS A FUNCTION OF DIURNAL HEATING DURING THE DAY.
INSTABILITY/SHEAR PROFILES STILL APPEAR TO NOT SUPPORT MORE
ORGANIZED CONVECTION AND THUS THE CHANCE OF A STRONG TO SEVERE
STORM SEEMS LIMITED AT THIS TIME. TEMP FORECAST CONTINUES TO LEAN
TOWARD THE WARMER MET GUIDANCE WITH NAM 850MB TEMPS AROUND 14-15C
LEADING TO FORECAST HIGH NEAR 80 ACROSS MUCH OF THE AREA.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
CDFNT WILL CONT TO SAG SEWD TUE EVE AND WILL BE ACCOMPANIED BY
LINGERING SHWRS AND TSTMS. NAM IS MORE AMPLIFIED WITH ASSOCIATED
H5 SHRTWV TROF AND MAINTAINS PCPN THRU WED MRNG IN THE MTNS...BUT
GFS IS MORE PROGRESSIVE WITH THE SYSTEM...ENDING PCPN BY LATE TUE
NGT. LOW POPS WERE RETAINED THRU WED MRNG TO REFLECT THIS
UNCERTAINTY.
AMID BUILDING SFC HIPRES...POST-FRONTAL AMS WILL DRY SOMEWHAT. AS
A RESULT...INSTBY WILL BE LMTD TO HIGHER TERRAIN WED-THU. THUS...
POPS WERE INCLUDED ONLY IN ZONES WITH HIGHER TERRAIN. ANY CNVCTN
WILL BE DIURNALLY DRIVEN.
POST-FRONTAL MAXIMA WILL BE ON THE COOLER SIDE IN THE MID-UPR 70S.
MINIMA WILL BE DICTATED BY DEG OF DRYING OF LOW-LVL AMS...LKLY IN
THE 50S. UPDATE...KRAMAR
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
MDLS CONT TO DEPICT DVLPMNT OF A BROAD SRN CONUS RIDGE FOR THE
LONG TERM PD WITH GENL RIDGE AXIS POSITIONING ACRS THE GREAT
LAKES. WARMER TEMPS ARE THUS IN STORE FOR THE UPR OH VALLEY REGION
WITH WEEKEND READINGS PROGGED WELL INTO THE 80S AS PER HIGHER MOS
GUIDANCE.
GRADUALLY INCRSG POPS...TO CHC NMBRS FOR THE WEEKEND...WERE ALSO
INCLUDED...BUT TIMING WL BE DEPENDENT ON SHRTWV PASSAGE ACRS THE
NRN PERIPHERY OF THE RIDGE...SO CONFIDENCE IN THAT PARAMETER IS
MINIMAL AT THIS JUNCTURE OF THE FORECAST PROCESS.
&&
.AVIATION /21Z MONDAY THROUGH SATURDAY/...
VFR CONDITIONS WILL MOSTLY PREVAIL THROUGH THIS EVENING...ALTHOUGH
BRIEF RESTRICTIONS WILL BE POSSIBLE IN ISOLATED SHOWERS AND
THUNDERSTORMS THIS AFTERNOON WITH THE CHANCE INCREASING TONIGHT.
COVERAGE WILL BE SPARSE...ALTHOUGH IF A SHOWER/STORM HITS A
TERMINAL VISIBILITY RESTRICTIONS COULD BRIEFLY DROP TO IFR. WINDS
WILL BE SOUTHWESTERLY THIS AFTERNOON AT 5-10KTS.
WITH A FRONT DROPPING SOUTHWARD TONIGHT...THE CHANCE FOR SHOWERS AND
THUNDERSTORMS WILL CONTINUE...ALTHOUGH CONFIDENCE IN LOCATION AND
AREAL COVERAGE IS TOO LOW TO INCLUDE IN THE TERMINALS AT THIS
POINT. A BRIEF PERIOD OF RESTRICTIONS WITH FOG WILL BE POSSIBLE
DURING THE PRE-DAWN HOURS ON TUESDAY. IFR CONDITIONS ARE FORECAST
ALONG AND SOUTH OF THE BOUNDARY AT KMGW/KZZV WITH MVFR ELSEWHERE.
A FRONTAL BOUNDARY WILL PUSH ACROSS THE AREA ON TUESDAY...WITH A
BETTER CHANCE OF BRIEF IFR RESTRICTIONS WITH SHOWERS AND
THUNDERSTORMS ACROSS THE TERMINALS DURING THE DAY.
OUTLOOK.../TUESDAY NIGHT THROUGH FRIDAY/...
THE FRONTAL BOUNDARY WILL PUSH SOUTHEAST OF THE AREA TUESDAY
NIGHT...BRINGING SHOWERS AND THUNDERSTORMS TO AN END. HIGH
PRESSURE WILL THEN BUILD IN FROM THE NORTHWEST...ALLOWING FOR VFR
CONDITIONS TO PREVAIL FOR THE MAJORITY ON WEDNESDAY THROUGH FRIDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
315 PM EDT MON JUN 17 2013
.SYNOPSIS...
A FRONTAL BOUNDARY WILL REMAIN IN THE VICINITY OF THE UPPER OHIO
VALLEY...MAINTAINING CHANCES FOR SHOWERS AND THUNDERSTORMS THROUGH
THE DAY ON TUESDAY. HIGH PRESSURE WILL MOVE INTO THE REGION FROM
THE NORTHWEST ON WEDNESDAY...PROMOTING GENERALLY DRY AND
SEASONABLE WEATHER THROUGH THURSDAY.
&&
.NEAR TERM /THROUGH TUESDAY/...
AN ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO INCREASE
POPS TO ACCOUNT FOR DEVELOPING UPSTREAM SHOWERS AND THUNDERSTORMS.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A WEAK AND BROAD
CYCLONIC FLOW ACROSS THE UPPER OHIO VALLEY WITH DRIER AND SLIGHTLY
WARMER AIR ADVECTING IN FROM THE WEST. 850MB CONVERGENCE ALONG THE
MASON-DIXON LINE HAS WEAKENED MOSTLY WITH ONLY AN ISOLATED SHOWER
OR TWO REMAINING ACROSS THE ALLEGHENY FRONT. THE CONVERGENCE ZONE
HAS BEEN CO-LOCATED WITH A FRONTAL BOUNDARY NEAR THE MASON-DIXON
LINE. ALTHOUGH A THERMAL GRADIENT IS LACKING ALONG THE BOUNDARY...IT
CAN BE MORE EASILY DEPICTED BY SURFACE DEW POINT AND EQUIVALENT
POTENTIAL TEMPERATURE GRADIENTS. UPSTREAM...SOME LAKE BREEZE
INTERACTION (LAKE ERIE) WITH A SOUTHWESTERLY LOW-LEVEL FLOW HAS
SETUP A CONVERGENCE ZONE OF CONVECTION ACROSS NORTHERN OHIO.
THIS EVENING...THE FRONTAL BOUNDARY WILL REMAIN FAIRLY
STATIONARY IN THE VICINITY OF THE MASON-DIXON LINE. THERE ARE A
FEW CONTRIBUTORS HAT HAVE LED TO THE FORECAST FOR POSSIBLE
CONVECTION INTO THE EVENING. THESE INCLUDE...THE FRONTAL
BOUNDARY AND INSTABILITY INCREASING TO 1500-2500 J/KG SBCAPE
FOR LOCATIONS PRIMARILY SOUTH OF PITTSBURGH. FOR LOCATIONS NORTH
AND WEST OF PITTSBURGH...CHC OF THUNDERSTORMS IS FORECAST WITH
ONGOING DEVELOPING CONVECTION IN NORTHERN OHIO. WITH THIS AND THE 14Z
HRRR IN MIND HAVE GONE WITH SCHC INCREASING TO CHC POP THROUGH
MUCH THE EVENING.
TONIGHT...LINGERING CONVECTION WILL BE ONGOING FROM DIURNAL
ACTIVITY RELATED TO THE SERIES OF BOUNDARIES LOCATED IN THE
VICINITY OF THE FORECAST AREA. WITH THE LOSS OF
HEATING...CONVECTION WILL BEGIN TO DIMINISH ACROSS THE AREA.
HOWEVER...NORTHERN BOUNDARY WILL THEN BEGIN TO DROP SOUTHWARD AS A
FRONT. THUS...THE FORCING PROVIDED FROM THIS FEATURE WILL ALLOW
FOR THE CHC OF SHOWERS AND THUNDERSTORMS TO CONTINUE ACROSS MUCH
OF THE AREA NOCTURNALLY. OVERNIGHT LOWS ARE CLOSER TO THE WARMER
MET...WITH LOWS RANGING FROM THE MID 60S IN EASTERN OHIO...SW
PA...AND NORTHERN WV TO THE UPPER 50S ACROSS THE ALLEGHENY FRONT
AND LAUREL HIGHLANDS.
TUESDAY...THE COLD FRONT WILL CONTINUE TO DROP SLOWLY SOUTHWARD ACROSS
THE AREA...WITH THE COVERAGE OF SHOWER AND THUNDERSTORMS INCREASING
AS A FUNCTION OF DIURNAL HEATING DURING THE DAY.
INSTABILITY/SHEAR PROFILES STILL APPEAR TO NOT SUPPORT MORE
ORGANIZED CONVECTION AND THUS THE CHANCE OF A STRONG TO SEVERE
STORM SEEMS LIMITED AT THIS TIME. TEMP FORECAST CONTINUES TO LEAN
TOWARD THE WARMER MET GUIDANCE WITH NAM 850MB TEMPS AROUND 14-15C
LEADING TO FORECAST HIGH NEAR 80 ACROSS MUCH OF THE AREA.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
CDFNT WILL CONT TO SAG SEWD TUE EVE AND WILL BE ACCOMPANIED BY
LINGERING SHWRS AND TSTMS. NAM IS MORE AMPLIFIED WITH ASSOCIATED
H5 SHRTWV TROF AND MAINTAINS PCPN THRU WED MRNG IN THE MTNS...BUT
GFS IS MORE PROGRESSIVE WITH THE SYSTEM...ENDING PCPN BY LATE TUE
NGT. LOW POPS WERE RETAINED THRU WED MRNG TO REFLECT THIS
UNCERTAINTY.
AMID BUILDING SFC HIPRES...POST-FRONTAL AMS WILL DRY SOMEWHAT. AS
A RESULT...INSTBY WILL BE LMTD TO HIGHER TERRAIN WED-THU. THUS...
POPS WERE INCLUDED ONLY IN ZONES WITH HIGHER TERRAIN. ANY CNVCTN
WILL BE DIURNALLY DRIVEN.
POST-FRONTAL MAXIMA WILL BE ON THE COOLER SIDE IN THE MID-UPR 70S.
MINIMA WILL BE DICTATED BY DEG OF DRYING OF LOW-LVL AMS...LKLY IN
THE 50S. UPDATE...KRAMAR
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
MDLS CONT TO DEPICT DVLPMNT OF A BROAD SRN CONUS RIDGE FOR THE
LONG TERM PD WITH GENL RIDGE AXIS POSITIONING ACRS THE GREAT
LAKES. WARMER TEMPS ARE THUS IN STORE FOR THE UPR OH VALLEY REGION
WITH WEEKEND READINGS PROGGED WELL INTO THE 80S AS PER HIGHER MOS
GUIDANCE.
GRADUALLY INCRSG POPS...TO CHC NMBRS FOR THE WEEKEND...WERE ALSO
INCLUDED...BUT TIMING WL BE DEPENDENT ON SHRTWV PASSAGE ACRS THE
NRN PERIPHERY OF THE RIDGE...SO CONFIDENCE IN THAT PARAMETER IS
MINIMAL AT THIS JUNCTURE OF THE FORECAST PROCESS.
&&
.AVIATION /19Z MONDAY THROUGH SATURDAY/...
VFR CONDITIONS WILL MOSTLY PREVAIL THROUGH THIS EVENING...ALTHOUGH
BRIEF RESTRICTIONS WILL BE POSSIBLE IN ISOLATED SHOWERS AND
THUNDERSTORMS THIS AFTERNOON WITH THE CHANCE INCREASING TONIGHT.
COVERAGE WILL BE SPARSE...ALTHOUGH IF A SHOWER/STORM HITS A
TERMINAL VISIBILITY RESTRICTIONS COULD BRIEFLY DROP TO IFR. WINDS
WILL BE SOUTHWESTERLY THIS AFTERNOON AT 5-10KTS.
WITH A FRONT DROPPING SOUTHWARD TONIGHT...THE CHANCE FOR SHOWERS AND
THUNDERSTORMS WILL CONTINUE...ALTHOUGH CONFIDENCE IN LOCATION AND
AREAL COVERAGE IS TOO LOW TO INCLUDE IN THE TERMINALS AT THIS
POINT. A BRIEF PERIOD OF RESTRICTIONS WITH FOG WILL BE POSSIBLE
DURING THE PRE-DAWN HOURS ON TUESDAY. IFR CONDITIONS ARE FORECAST
ALONG AND SOUTH OF THE BOUNDARY AT KMGW/KZZV WITH MVFR ELSEWHERE.
A FRONTAL BOUNDARY WILL PUSH ACROSS THE AREA ON TUESDAY...WITH A
BETTER CHANCE OF BRIEF IFR RESTRICTIONS WITH SHOWERS AND
THUNDERSTORMS ACROSS THE TERMINALS DURING THE DAY.
OUTLOOK.../TUESDAY NIGHT THROUGH FRIDAY/...
THE FRONTAL BOUNDARY WILL PUSH SOUTHEAST OF THE AREA TUESDAY
NIGHT...BRINGING SHOWERS AND THUNDERSTORMS TO AN END. HIGH
PRESSURE WILL THEN BUILD IN FROM THE NORTHWEST...ALLOWING FOR VFR
CONDITIONS TO PREVAIL FOR THE MAJORITY ON WEDNESDAY THROUGH FRIDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
250 PM EDT MON JUN 17 2013
.SYNOPSIS...
A FRONTAL BOUNDARY WILL REMAIN IN THE VICINITY OF THE UPPER OHIO
VALLEY...ALLOWING THE CHANCE OF SHOWERS AND THUNDERSTORMS TO
CONTINUE THROUGH THE DAY ON TUESDAY. HIGH PRESSURE WILL THEN MOVE
INTO THE REGION FROM THE NORTHWEST...ALLOWING FOR DRY AND
SEASONABLE WEATHER FOR WEDNESDAY AND THURSDAY.
&&
.NEAR TERM /THROUGH TUESDAY/...
AN ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO INCREASE
POPS TO ACCOUNT FOR DEVELOPING UPSTREAM SHOWERS AND THUNDERSTORMS.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A WEAK AND BROAD
CYCLONIC FLOW ACROSS THE UPPER OHIO VALLEY WITH DRIER AND SLIGHTLY
WARMER AIR ADVECTING IN FROM THE WEST. 850MB CONVERGENCE ALONG THE
MASON-DIXON LINE HAS WEAKENED MOSTLY WITH ONLY AN ISOLATED SHOWER
OR TWO REMAINING ACROSS THE ALLEGHENY FRONT. THE CONVERGENCE ZONE
HAS BEEN CO-LOCATED WITH A FRONTAL BOUNDARY NEAR THE MASON-DIXON
LINE. ALTHOUGH A THERMAL GRADIENT IS LACKING ALONG THE BOUNDARY...IT
CAN BE MORE EASILY DEPICTED BY SURFACE DEW POINT AND EQUIVALENT
POTENTIAL TEMPERATURE GRADIENTS. UPSTREAM...SOME LAKE BREEZE
INTERACTION (LAKE ERIE) WITH A SOUTHWESTERLY LOW-LEVEL FLOW HAS
SETUP A CONVERGENCE ZONE OF CONVECTION ACROSS NORTHERN OHIO.
THIS EVENING...THE FRONTAL BOUNDARY WILL REMAIN FAIRLY
STATIONARY IN THE VICINITY OF THE MASON-DIXON LINE. THERE ARE A
FEW CONTRIBUTORS HAT HAVE LED TO THE FORECAST FOR POSSIBLE
CONVECTION INTO THE EVENING. THESE INCLUDE...THE FRONTAL
BOUNDARY AND INSTABILITY INCREASING TO 1500-2500 J/KG SBCAPE
FOR LOCATIONS PRIMARILY SOUTH OF PITTSBURGH. FOR LOCATIONS NORTH
AND WEST OF PITTSBURGH...CHC OF THUNDERSTORMS IS FORECAST WITH
ONGOING DEVELOPING CONVECTION IN NORTHERN OHIO. WITH THIS AND THE 14Z
HRRR IN MIND HAVE GONE WITH SCHC INCREASING TO CHC POP THROUGH
MUCH THE EVENING.
TONIGHT...LINGERING CONVECTION WILL BE ONGOING FROM DIURNAL
ACTIVITY RELATED TO THE SERIES OF BOUNDARIES LOCATED IN THE
VICINITY OF THE FORECAST AREA. WITH THE LOSS OF
HEATING...CONVECTION WILL BEGIN TO DIMINISH ACROSS THE AREA.
HOWEVER...NORTHERN BOUNDARY WILL THEN BEGIN TO DROP SOUTHWARD AS A
FRONT. THUS...THE FORCING PROVIDED FROM THIS FEATURE WILL ALLOW
FOR THE CHC OF SHOWERS AND THUNDERSTORMS TO CONTINUE ACROSS MUCH
OF THE AREA NOCTURNALLY. OVERNIGHT LOWS ARE CLOSER TO THE WARMER
MET...WITH LOWS RANGING FROM THE MID 60S IN EASTERN OHIO...SW
PA...AND NORTHERN WV TO THE UPPER 50S ACROSS THE ALLEGHENY FRONT
AND LAUREL HIGHLANDS.
TUESDAY...THE COLD FRONT WILL CONTINUE TO DROP SLOWLY SOUTHWARD ACROSS
THE AREA...WITH THE COVERAGE OF SHOWER AND THUNDERSTORMS INCREASING
AS A FUNCTION OF DIURNAL HEATING DURING THE DAY.
INSTABILITY/SHEAR PROFILES STILL APPEAR TO NOT SUPPORT MORE
ORGANIZED CONVECTION AND THUS THE CHANCE OF A STRONG TO SEVERE
STORM SEEMS LIMITED AT THIS TIME. TEMP FORECAST CONTINUES TO LEAN
TOWARD THE WARMER MET GUIDANCE WITH NAM 850MB TEMPS AROUND 14-15C
LEADING TO FORECAST HIGH NEAR 80 ACROSS MUCH OF THE AREA.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
DRY HIGH PRES WILL BEGIN TO BUILD TUESDAY NIGHT AND SUPPRESS PCPN
FOR WEDNESDAY AND THURSDAY...BUT SEASONABLY COOL AIR UNDER
TROUGHING ALOFT WILL LIMIT TEMP RECOVERY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
MDLS CONT TO DEPICT DVLPMNT OF A BROAD SRN CONUS RIDGE FOR THE
LONG TERM PD WITH GENL RIDGE AXIS POSITIONING ACRS THE GREAT
LAKES. WARMER TEMPS ARE THUS IN STORE FOR THE UPR OH VALLEY REGION
WITH WEEKEND READINGS PROGGED WELL INTO THE 80S AS PER HIGHER MOS
GUIDANCE.
GRADUALLY INCRSG POPS...TO CHC NMBRS FOR THE WEEKEND...WERE ALSO
INCLUDED...BUT TIMING WL BE DEPENDANT ON SHRTWV PASSAGE ACRS THE
NRN PERIPHERY OF THE RIDGE...SO CONFIDENCE IN THAT PARAMETER IS
MINIMAL AT THIS JUNCTURE OF THE FORECAST PROCESS.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
VFR CONDITIONS WILL MOSTLY PREVAIL THROUGH THIS EVENING...ALTHOUGH
BRIEF RESTRICTIONS WILL BE POSSIBLE IN ISOLATED SHOWERS AND
THUNDERSTORMS THIS AFTERNOON WITH THE CHANCE INCREASING TONIGHT.
COVERAGE WILL BE SPARSE...ALTHOUGH IF A SHOWER/STORM HITS A
TERMINAL VISIBILITY RESTRICTIONS COULD BRIEFLY DROP TO IFR. WINDS
WILL BE SOUTHWESTERLY THIS AFTERNOON AT 5-10KTS.
WITH A FRONT DROPPING SOUTHWARD TONIGHT...THE CHANCE FOR SHOWERS AND
THUNDERSTORMS WILL CONTINUE...ALTHOUGH CONFIDENCE IN LOCATION AND
AREAL COVERAGE IS TOO LOW TO INCLUDE IN THE TERMINALS AT THIS
POINT. A BRIEF PERIOD OF RESTRICTIONS WITH FOG WILL BE POSSIBLE
DURING THE PRE-DAWN HOURS ON TUESDAY. IFR CONDITIONS ARE FORECAST
ALONG AND SOUTH OF THE BOUNDARY AT KMGW/KZZV WITH MVFR ELSEWHERE.
A FRONTAL BOUNDARY WILL PUSH ACROSS THE AREA ON TUESDAY...WITH A
BETTER CHANCE OF BRIEF IFR RESTRICTIONS WITH SHOWERS AND
THUNDERSTORMS ACROSS THE TERMINALS DURING THE DAY.
OUTLOOK.../TUESDAY NIGHT THROUGH FRIDAY/...
THE FRONTAL BOUNDARY WILL PUSH SOUTHEAST OF THE AREA TUESDAY
NIGHT...BRINGING SHOWERS AND THUNDERSTORMS TO AN END. HIGH
PRESSURE WILL THEN BUILD IN FROM THE NORTHWEST...ALLOWING FOR VFR
CONDITIONS TO PREVAIL FOR THE MAJORITY ON WEDNESDAY THROUGH FRIDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
SYNOPSIS...WOODRUM
NEAR TERM...WOODRUM
AVIATION...WOODRUM
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
128 PM EDT MON JUN 17 2013
.SYNOPSIS...
A FRONTAL BOUNDARY WILL REMAIN IN THE VICINITY OF THE UPPER OHIO
VALLEY...ALLOWING THE CHANCE OF SHOWERS AND THUNDERSTORMS TO
CONTINUE THROUGH THE DAY ON TUESDAY. HIGH PRESSURE WILL THEN MOVE
INTO THE REGION FROM THE NORTHWEST...ALLOWING FOR DRY AND
SEASONABLE WEATHER FOR WEDNESDAY AND THURSDAY.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
AN ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO DECREASE
POPS SOUTH OF THE MASON-DIXON LINE EARLY THIS AFTERNOON.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A WEAK AND BROAD
CYCLONIC FLOW ACROSS THE UPPER OHIO VALLEY WITH DRIER AND SLIGHTLY
WARMER AIR ADVECTING IN FROM THE WEST. 850MB CONVERGENCE ALONG THE
MASON-DIXON LINE HAS WEAKENED MOSTLY WITH ONLY AN ISOLATED SHOWER
OR TWO REMAINING ACROSS THE ALLEGHENY FRONT. THE CONVERGENCE ZONE
HAS BEEN CO-LOCATED WITH A FRONTAL BOUNDARY NEAR THE MASON-DIXON
LINE. ALTHOUGH A THERMAL GRADIENT IS LACKING ALONG THE BOUNDARY...IT
CAN BE MORE EASILY DEPICTED BY SURFACE DEW POINT AND EQUIVALENT
POTENTIAL TEMPERATURE GRADIENTS.
THIS AFTERNOON...THE FRONTAL BOUNDARY WILL REMAIN FAIRLY
STATIONARY IN THE VICINITY OF THE MASON-DIXON LINE. THERE ARE TWO
POTENTIAL CONTRIBUTORS THAT HAVE LED TO THE FORECAST FOR POSSIBLE
ISOLATED CONVECTION THIS AFTERNOON...THE FRONTAL BOUNDARY AND
INSTABILITY INCREASING TO 1500-2500 J/KG SBCAPE PRIMARILY SOUTH OF
PITTSBURGH. WITH THIS AND THE 14Z HRRR IN MIND HAVE GONE WITH SCHC
POP THROUGH MUCH OF THE AFTERNOON/EVENING. FOR TEMPS...UTILIZED RECENT
TRENDS IN OBS ALONG WITH RAP 850MB TEMPS TO GO A FEW DEGREES ABOVE
A MAV/MET BLEND. HIGHS TODAY WILL REACH THE LOWER 80S ACROSS MOST
LOCATIONS WITH HIGHS IN THE MID 70S ACROSS THE HIGHER ELEVATIONS
OF WV/MD.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH THURSDAY/...
CHC POPS WERE MAINTAINED TONIGHT...BUT SHIFTED SWD INTO TUESDAY AS
SECONDARY FRONT/OUTFLOW PROGRESS AS ANOTHER DISTURBANCE/JET STREAK
CROSS THE REGION.
DRY HIGH PRES WL BLD THEREAFTER AND SUPPRESS PCPN FOR WEDNESDAY
AND THURSDAY...BUT SEASONABLY COOL AIR UNDR TROFG ALOFT WL LIMIT
TEMP RECOVERY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
MDLS CONT TO DEPICT DVLPMNT OF A BROAD SRN CONUS RIDGE FOR THE
LONG TERM PD WITH GENL RIDGE AXIS POSITIONING ACRS THE GREAT
LAKES. WARMER TEMPS ARE THUS IN STORE FOR THE UPR OH VALLEY REGION
WITH WEEKEND READINGS PROGGED WELL INTO THE 80S AS PER HIGHER MOS
GUIDANCE.
GRADUALLY INCRSG POPS...TO CHC NMBRS FOR THE WEEKEND...WERE ALSO
INCLUDED...BUT TIMING WL BE DEPENDANT ON SHRTWV PASSAGE ACRS THE
NRN PERIPHERY OF THE RIDGE...SO CONFIDENCE IN THAT PARAMETER IS
MINIMAL AT THIS JUNCTURE OF THE FORECAST PROCESS.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
VFR CONDITIONS WILL MOSTLY PREVAIL THROUGH THIS EVENING...ALTHOUGH BRIEF
RESTRICTIONS WILL BE POSSIBLE IN ISOLATED SHOWERS AND
THUNDERSTORMS THIS AFTERNOON WITH THE CHANCE INCREASING TONIGHT.
HAVE NOT INCLUDED THUNDERSTORMS IN THE TAFS THROUGH 12Z AT THIS
MOMENT AS COVERAGE WILL BE TOO SPARSE...ALTHOUGH IF A SHOWER/STORM
HITS A TERMINAL VISIBILITY RESTRICTIONS COULD BRIEFLY DROP TO IFR.
WINDS WILL BE SOUTHWESTERLY THIS AFTERNOON AT 5-10KTS.
A BRIEF PERIOD OF RESTRICTIONS WITH FOG/MIST WILL BE POSSIBLE
DURING THE PRE-DAWN HOURS ON TUESDAY. IFR CONDITIONS ARE FORECAST
ALONG AND SOUTH OF THE BOUNDARY AT KMGW/KZZV WITH MVFR ELSEWHERE. A
FRONTAL BOUNDARY WILL PUSH ACROSS THE AREA ON TUESDAY...WITH A
BETTER CHANCE OF BRIEF IFR RESTRICTIONS WITH SHOWERS AND
THUNDERSTORMS ACROSS THE TERMINALS DURING THE DAY.
OUTLOOK.../TUESDAY NIGHT THROUGH FRIDAY/...
THE FRONTAL BOUNDARY WILL PUSH SOUTHEAST OF THE AREA TUESDAY
NIGHT...BRINGING SHOWERS AND THUNDERSTORMS TO AN END. HIGH
PRESSURE WILL THEN BUILD IN FROM THE NORTHWEST...ALLOWING FOR VFR
CONDITIONS TO PREVAIL FOR THE MAJORITY ON WEDNESDAY THROUGH FRIDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
SYNOPSIS...WOODRUM
NEAR TERM...WOODRUM
AVIATION...WOODRUM
AREA FORECAST DISCUSSION
NWS JACKSON MS
431 PM CDT MON JUN 17 2013
.DISCUSSION...
THERE HAVE BEEN TWO AREAS OF FOCUS FOR CONVECTIVE DEVELOPMENT THIS
AFTERNOON. A COMPLEX OF STORMS THAT DEVELOPED EARLY THIS MORNING OVER
NORTH CENTRAL MS INDUCED A STRONG OUTFLOW BOUNDARY THAT WORKED ITS
WAY SOUTHWARD TO JUST ABOUT THE I-20 CORRIDOR IN CENTRAL/EASTERN MS.
MORNING RUNS OF THE HRRR WERE CORRECT IN SHOWING TSTM DEVELOPMENT
ALONG THE BOUNDARY IN CENTRAL MS...AND RELATIVELY STRONG LOW/MID
LEVEL FLOW IS NOW FORCING THE BOUNDARY TO LIFT OUT AHEAD OF AN
UPSTREAM CONVECTIVE COMPLEX. THE UPSTREAM CONVECTIVE COMPLEX MANAGED
TO INITIATE NEW SHOWER/TSTM DEVELOPMENT AS IT CROSS THE
ARKLATEX...BUT WHAT WAS A SOLID LINE OF SHOWERS/TSTM DEGENERATED INTO
A BROKEN LINE OF SHOWERS AS IT MOVED INTO AND AREA OF NEGATIVE LOW
LEVEL THETAE ADVECTION AND WESTERLY LOW LEVEL FLOW ALONG THE MS
RIVER. AS THE RESIDUAL BOUNDARY MOVES FARTHER EAST...THE ENVIRONMENT
MAY BE MORE SUPPORTIVE OF A FEW STORMS OVER CENTRL MS THIS EVENING.
FAST WESTERLY FLOW WILL SEND MORE UPPER LEVEL PERTURBATIONS ACROSS
THE ARKLAMISS FOR THE NEXT COUPLE OF DAYS. LOW LEVEL MOISTURE
TRANSPORT AND CONVERGENCE WILL INCREASE LATER TONIGHT INTO TUESDAY
AND PERHAPS TUESDAY EVENING. THIS SHOULD BE THE MOST ACTIVE
CONVECTIVE PERIOD AND HAVE GENERALLY ACCEPTED HIGH MAV MOS GUIDANCE
POPS...BUT INCREASED POPS SOME OVER SOUTHERN PORTIONS OF THE AREA
TUESDAY INTO TUESDAY NIGHT GIVEN SOUTHWARD TRENDS IN GUIDANCE QPF
FIELDS. AS DISCUSSED IN PREVIOUS DISCUSSIONS...TRYING TO PINPOINT
SPECIFIC CONVECTIVE SYSTEM PASSES ACROSS THE ARKLAMISS WILL BE
DIFFICULT IN THIS PATTERN GIVEN LITTLE HELP FROM EXPLICIT HIGH-RES
GUIDANCE. WILL THERE KEEP THE FORECAST MORE GENERAL WITH THE IDEA
THAT CONVECTION WILL INCREASE AGAIN LATER TONIGHT INTO TUESDAY
MORNING. THE BETTER DAYTIME HEATING MAY TAKE PLACE ACROSS SOUTHERN
PORTIONS OF THE ARKLAMISS TUESDAY...BUT THERE WILL BE SOME RISK FOR
STRONG TO SEVERE STORMS FOR MOST OF THE FORECAST AREA. /EC/
WEDNESDAY THROUGH NEXT MONDAY...MODELS HAVE TRENDED A LITTLE DRIER
FOR WEDNESDAY INTO THURSDAY AND POPS HAVE TRENDED LOWER. AN UPPER
RIDGE WILL BUILD EAST INTO THE FORECAST AREA FRIDAY INTO THE WEEKEND.
CHANCES FOR MAINLY AFTERNOON AND EARLY EVENING SHOWERS AND STORMS
WILL REMAIN OVER PARTS OF THE FORECAST AREA DURING THIS TIME AND INTO
NEXT MONDAY. CONVECTION FRIDAY THROUGH MONDAY IS EXPECTED TO BE MORE
DIURNALLY DRIVEN AND ISOLATED TO SCATTERED IN NATURE COMPARED TO THE
MORE ORGANIZED CONVECTION SEEN EARLIER IN THE WORK WEEK.
OTHERWISE...WARM AND VERY HUMID CONDITIONS WILL PERSIST THROUGH THE
ENTIRE PERIOD. HIGHS EACH AFTERNOON WILL RANGE IN THE LOW TO MIDDLE
90S. GUIDANCE SUGGESTED AS THE RIDGE BUILT IN FRIDAY...HIGHS COULD
RANGE FROM 95-97. GIVEN EXPECTED WET GROUND CONDITIONS DURING THIS
TIME...FELT THESE WERE TOO HIGH. THEREFORE I KNOCKED OFF 2-3
DEGREES AND NOW HAVE HIGHS RANGING FROM 92-94 ON FRIDAY. ELSEWHERE
THROUGH THE PERIOD...BOTH GUIDANCE HIGH AND LOW TEMPERATURES LOOKED
REASONABLE. /19/EC/
&&
.AVIATION...
FOR TONIGHT...THERE LOOKS TO BE SOME LINGERING STORM CHANCES
OVERNIGHT AND SOME RISK FOR SOME MVFR CONDITIONS FOR THE AREAS THAT
RECEIVED PRECIP.
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 71 87 68 93 / 52 69 38 19
MERIDIAN 71 87 67 92 / 52 73 49 15
VICKSBURG 73 87 66 92 / 53 57 29 21
HATTIESBURG 73 91 71 94 / 29 56 41 40
NATCHEZ 72 87 70 91 / 45 61 29 42
GREENVILLE 72 87 67 92 / 71 48 15 12
GREENWOOD 71 86 66 91 / 73 50 19 12
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
441 PM CDT MON JUN 17 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 440 PM CDT MON JUN 17 2013
THE MAIN CONCERN DURING THE NEXT 24 HOURS CONTINUES TO CENTER
AROUND THE VERY TRICKY...AND CONSTANTLY-EVOLVING THUNDERSTORM
CHANCES...OR LACK THEREOF IN THIS NORTHWEST FLOW PATTERN. ALTHOUGH
AT LEAST A LOW-END RISK FOR SEVERE STORMS CONTINUES THIS
EVENING/TONIGHT MAINLY WEST OF HIGHWAY 281...IT DOES NOT LOOK TO
BE NEARLY AS WIDESPREAD/SIGNIFICANT AS THE SUNDAY EVENING EVENT.
20Z OBJECTIVE SURFACE ANALYSIS INDICATES A FAIRLY NON-DESCRIPT
PATTERN ACROSS THE AREA...WITH THE MAIN SYNOPTIC-SCALE COLD FRONT
NOTED WELL TO THE SOUTH ACROSS OK/NORTHWEST TX. IT HAS BEEN
COMPLETELY RAIN/THUNDER-FREE THE ENTIRE DAY SO FAR CWA-WIDE. WITH
THE MAIN SURFACE FRONT TO THE SOUTH...AND A MODEST 1018 MILLIBAR
RIDGE AXIS CENTERED JUST NORTH OF THE CWA...BREEZES THIS AFTERNOON
ARE GENERALLY SOME VARIATION OF NORTHERLY/EASTERLY AT NO MORE THAN
10 MPH. ALOFT...WATER VAPOR IMAGERY AND SHORT TERM MODEL DATA
DEPICTS THE CONTINUATION OF WEST-NORTHWEST FLOW ALOFT OVER THE
CENTRAL PLAINS...FLOWING OVER THE TOP OF A FAIRLY LOW-AMPLITUDE
RIDGE EXTENDING NORTH-SOUTH THROUGH THE CENTRAL/SOUTHERN ROCKIES.
THERE ARE GENERALLY THREE SHORTWAVE TROUGHS/RIPPLES OF NOTE ACROSS
THE REGION...ONE DEPARTING EASTWARD ALONG THE KS/MO/OK BORDER
AREA...ONE SLIDING SOUTHEAST ACROSS ND...AND THE OTHER A FAIRLY
SUBTLE DISTURBANCE DRIFTING SOUTHEAST ACROSS NORTHWEST NEB...WHICH
HAS HELPED TRIGGER SOME THUS-FAR NON-SEVERE THUNDERSTORMS STILL
50-100 MILES WEST- NORTHWEST OF THE CWA AT THIS HOUR. VISIBLE
SATELLITE IMAGERY REVEALS NOTHING MORE THAN A SCATTERED FAIR
WEATHER CUMULUS FIELD OVER MOST OF THE CWA...WITH A FEW THICKER
MID-CLOUD AREAS DRIFTING INTO NORTHERN/WESTERN COUNTIES OUT AHEAD
OF THE WESTERN NEBRASKA CONVECTION. HIGH TEMPS ARE GENERALLY ON
TRACK TO TOP OUT SOMEWHERE IN THE 80S MOST ALL AREAS.
LATE THIS AFTERNOON INTO TONIGHT...PINNING DOWN THE HOURLY DETAILS
OF POPS/THUNDERSTORMS CONTINUES TO BE A CHALLENGE. REGARDING THE
BIG PICTURE ALOFT BETWEEN NOW AND SUNRISE...THE VERY SUBTLE MID
LEVEL DISTURBANCES ROTATING AROUND THE TOP OF THE RIDGE ACROSS THE
WY/CO/NORTHWEST NEB AREA WILL CONTINUE TO DRIFT SOUTHEAST...WHILE
THE SOMEWHAT MORE ORGANIZED DISTURBANCE NOW OVER ND WILL REACH THE
NORTH CENTRAL IA BY SUNRISE. FOR THE FORECAST...HAVE CONSIDERED A
VARIETY OF DETERMINISTIC AND HIGH-RES MODEL SOLUTIONS
TONIGHT...WHICH INVARIABLY PAINT AT LEAST SLIGHTLY DIFFERENT
PICTURES...BUT LEANING MAINLY TOWARD THE HRRR/4 KM-WRF SOLUTIONS
WHICH SEEM TO HAVE A DECENT HANDLE ON THE ONGOING CONVECTION TO
THE WEST. THROUGH 7PM...HAVE KEPT THE MAJORITY OF THE CWA POP-
FREE...WITH ONLY SLIGHT CHANCES CREEPING INTO ABOUT THE NORTHWEST
1/3 OF THE CWA AS CONVECTION DEVELOPS OVERHEAD AND/OR DRIFTS IN
FROM THE NORTHWEST. BETWEEN 00Z-04Z/7PM-11PM...SPREAD AT LEAST
SLIGHT 20 PERCENT POPS INTO EVEN THE FAR SOUTHEAST
COUNTIES...WHILE RAISING INTO THE 40-50 PERCENT HIGH-CHANCE RANGE
ACROSS MUCH OF THE WEST. BY 00Z...LATEST RAP INDICATES AN
ENVIRONMENT AT LEAST MARGINALLY SUPPORTIVE OF SEVERE
WEATHER...WITH ROUGHLY 1500 J/KG OF 0-1KM CAPE MAINLY IN THE
NORTHWEST 1/2 OF THE CWA...AND 30-40 KNOTS OF 0-6KM DEEP LAYER
SHEAR. AS THE EVENING WEARS ON...INSTABILITY IS PROGGED TO DROP
OFF SLOWLY...BUT LIKELY REMAIN HIGHEST IN KS ZONES. AFTER
MIDNIGHT...CURRENT POPS MAY NOT BE NEARLY HIGH ENOUGH IF IN FACT A
SEMI-ORGANIZED BATCH OF CONVECTION DEVELOPS OVERHEAD OR MOVES
IN...BUT GIVEN INHERENT UNCERTAINTY HAVE CAPPED POPS AT NO MORE
THAN 40-50 PERCENT FOR NOW. GENERALLY HAVE FOLLOWED SPC SREF
SEVERE THUNDER PROBABILITIES BY CONTINUING A MENTION OF STRONG TO
MARGINALLY SEVERE STORMS IN THE HAZARDOUS WEATHER OUTLOOK MAINLY
WEST OF HIGHWAY 281...WITH AN EXPECTATION OF A BROKEN LINE OF
CONVECTION DRIFTING IN. WORST-CASE SCENARIO WOULD SEEM TO BE A
60-70 MPH WIND EVENT IF STORMS CAN ORGANIZE INTO A COLD POOL...BUT
IN THEORY THIS SEEMS FAIRLY UNLIKELY GIVEN THAT CONVECTION SHOULD
LOSE INTENSITY AS IT HEADS EAST OUT OF WESTERN NEB/NORTHWEST
KS...SO WILL ONLY HIGHLIGHT A MARGINALLY SEVERE THREAT AT THIS
TIME. LATER IN THE NIGHT...THERE ARE SUGGESTIONS BY MODELS SUCH AS
THE NAM THAT A MODEST RIBBON OF LOW-MID LEVEL THETA-E ADVECTION IN
THE 850-700MB LAYER COULD SPARK A NEW ROUND OF ELEVATED CONVECTION
MAINLY WITHIN THE NORTHEAST QUADRANT OF THE CWA IN CLOSEST
PROXIMITY TO THE SOUTHEAST-DRIFTING DAKOTAS SHORTWAVE...AND THUS
HAVE PUT POPS BACK INTO THESE NORTHEAST ZONES THROUGH THE NIGHT IN
CASE THIS OCCURS. MADE LITTLE CHANGE TO LOW TEMPS...WITH NEARLY
ALL AREAS SETTLING WITHIN A FEW DEGREES OF 60. ALSO...CANNOT
COMPLETELY RULE OUT SOME LIGHT FOG TONIGHT...BUT NOT EXPECTING
WIDESPREAD VISIBILITY RESTRICTIONS OF 1-2 MILES OR LESS THAT WOULD
REQUIRE FORMAL INCLUSION IN THE FORECAST.
TURNING TO THE TUESDAY DAYTIME PERIOD...UNCERTAINLY JUST KEEPS
GROWING...WITH SOME MODELS CONTINUING TO PAINT DAYTIME MORNING
CONVECTION POSSIBLY AS A CONTINUATION OF THE OVERNIGHT
ACTIVITY...AND ESPECIALLY WITHIN THE NORTHEAST 1/2 OF THE CWA IN
CLOSEST PROXIMITY TO THE SHORTWAVE TROUGH GLANCING BY TO THE EAST.
HOWEVER...BASED ON VARIOUS FACTORS INCLUDING
UNCERTAINTY/CONSISTENCY WITH PREVIOUS FORECAST AND LESS QPF IN
PREVIOUS MODEL RUNS...HAVE OPTED TO GO AHEAD AND LEAVE THE
MAJORITY OF THE DAYTIME HOURS RAIN/THUNDERSTORM-FREE FOR
NOW...WHILE ACKNOWLEDING THAT THE NEXT FEW SHIFTS MAY HAVE TO
INSERT SOME POST-SUNRISE POPS WITH LIMITED NOTICE. FOR
EXAMPLE...THE PREVIOUS 12Z NAM WAS ESSENTIALLY DRY DURING THE
DAY...BUT THE NEW 18Z RUN NOW HAS PLENTY OF DAYTIME
CONVECTION...WHICH COULD EASILY BE OVERDONE PER THE 12Z 4KM WRF-
NMM...WHICH FITS THE MORE COMMON CONCEPTUAL PICTURE OF LACK
OF FORCING IN THE WAKE OF THE IA SHORTWAVE TROUGH THAT CONTINUES
PASSING SOUTHEAST. THIS CONCEPTUAL PICTURE OF THIS PATTERN WOULD
ALSO SUGGEST THE BEST AFTERNOON STORM CHANCES WOULD BE IN OUR
WESTERN COUNTIES...AND THUS AT LEAST FOR NOW...THE ONLY
OFFICIAL THUNDERSTORM CHANCES IN THE CWA TOMORROW ARE FROM 3-7PM
IN WESTERN COUNTIES...WITH NO STRONG SIGNAL FOR SEVERE STORMS
SHOULD THEY OCCUR. AS HAS BEEN THE CASE LATELY...BE PREPARED FOR
SOME POTENTIALLY NOTABLE CHANGES TO THE TIMING/MAGNITUDE OF THESE
STORM CHANCES...AS LOOKING EVEN BEYOND THE FIRST 12 HOURS IS
PROVING DICEY...AND MORNING CONVECTION COULD BE A WILD CARD.
TEMP-WISE TOMORROW...ASSUMING DAYTIME CONVECTION DOES NOT BLOSSOM
AND CLOUD THINGS UP...EXPECT ANOTHER SEASONABLY WARM DAY AND
NUDGED UP HIGHS SLIGHTLY...GETTING MOST PLACES BETWEEN 81-86
DEGREES. BREEZES WILL START OUT LIGHT BUT PICK UP TO 10-15 MPH
FROM THE SOUTHEAST AS THE AFTERNOON WEARS ON WITH HIGHER GUSTS.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 440 PM CDT MON JUN 17 2013
PRIMARY FORECAST CONCERNS THROUGH THE LONG TERM PERIOD REVOLVE
AROUND PRECIPITATION CHANCES.
THE START OF THE LONG TERM PERIOD TUESDAY EVENING/NIGHT SHOWS THE
REGION REMAINING UNDER THE INFLUENCE OF WEAK/BROAD RIDGING IN THE
UPPER LEVELS...BETWEEN AREAS OF LOW PRESSURE NEAR THE FAR NERN CONUS
AND THE PAC NW COAST. EXPECTING THAT THERE WILL BE ACTIVITY ONGOING
OVER THE HIGH PLAINS BY 00Z...WITH THE MAIN CONCERN BEING HOW FAR
EAST/HOW MUCH OF THE CWA ENDS UP BEING AFFECTED. THIS ACTIVITY
LOOKS TO TAKE ITS TIME SLIDING EAST...WITH LOW POPS IN PLACE THROUGH
THE EARLY/MID EVENING HOURS. MODELS REMAIN IN DECENT AGREEMENT
SHOWING THE WRN PORTIONS OF THE CWA SEEING THE BETTER CHANCES OF
SEEING THUNDERSTORM...BUT ITS POSSIBLE NOT A WHOLE HECK OF A LOT
WILL MAKE IT...SO THERE ISNT A BIG RAMP UP IN POPS DURING THE
OVERNIGHT PERIOD.
AS WE LOOK TOWARD WEDNESDAY AND INTO THURSDAY...PRECIPITATION
CHANCES REMAIN IN THE FORECAST...BUT NOTHING IS CERTAINLY CLEAR
CUT. MODELS ARE IN GOOD AGREEMENT SHOWING THAT ABOVE MENTIONED PAC
NW UPPER LEVEL LOW PRESSURE SYSTEM SLIDING INLAND WEDNESDAY
MORNING...BUT BY THURSDAY MORNING HAS ONLY MOVED INTO THE WA/ID/MT
BORDER AREA. THE MAIN QUESTION LIES WITH THE TIMING/LOCATION OF
PIECES OF ENERGY EJECTED OUT AHEAD OF THE MAIN LOW. ITS IMPACT ON
THE CWA WILL DEPEND ON THE STRENGTH OF THE RIDGE...WHICH AT THIS
POINT LOOK TO REMAIN FAIRLY FLAT/BROAD...NOT STRONG ENOUGH TO SHIFT
THOSE BETTER CHANCES TO THE NORTH. PLENTY OF UNCERTAINTY ALREADY ON
WEDNESDAY...SOME MODELS SHOW THE WEST WITH THE BETTER CHANCES/OTHERS
THE EAST...AND DECIDED AT THIS POINT TO KEEP POPS ON THE LOWER
SIDE. WEDNESDAY NIGHT...DIDNT MAKE SIGNIFICANT CHANGES TO THE POPS
/WHICH REMAIN IN THE CHANCE CATEGORY/...WITH THERE STILL BEING SOME
SUPPORT OF ANOTHER ROUND OF ACTIVITY FROM THE WEST SLIDING
THROUGH...BUT WITH OTHERS STARTING TO TREND AWAY FROM THAT WASNT
GOING TO INCREASE THOSE CHANCES.
BY 12Z THURSDAY...MODELS STARTING TO DEPICT SOME SLIGHT
AMPLIFICATION OF THE RIDGE OVER THE PLAINS AS THAT PAC NW LOW
REMAINS IN PLACE. MAIN QUESTION IS WITH PRECIP CHANCES...AND
WHAT/IF ANYTHING IS LINGERING IN THE EAST IN THE MORNING AND WILL
ANYTHING FIRE IN THE WEST DURING THE AFTERNOON. ACCOMPANYING THIS
BUMP UP IN THE RIDGE IS WARMING TEMPERATURES IN THE LOWER/MID
LEVELS...AND CAPPING STARTS TO BECOME MORE OF A CONCERN. SOME
MODELS HAVE STARTED TRENDING TOWARD THAT CAP BUILDING IN AND KEEPING
THE DAY DRY...BUT A FEW ARE HANGING ON TO THE POTENTIAL FOR SOME
LINGERING ACTIVITY...SO WHILE POPS WERE LOWERED...THEY WERE NOT
COMPLETELY REMOVED AT THIS POINT.
THE FORECAST FOR FRIDAY AND SATURDAY IS DRY. THOUGH THE UPPER LEVEL
PATTERN IS BECOMING MORE SOUTHWESTERLY AS THE MAIN RIDGE AXIS
BECOMES MORE ORIENTATED IN A SW/NE DIRECTION JUST EAST OF THE
CWA...THE WARMER MID LEVEL TEMPS/CAPPING AND LOCATION OF SFC
BOUNDARIES LOOKS TO KEEP THE BETTER CHANCES JUST OFF TO THE CWA.
FOR SUNDAY AND MONDAY...PRECIP CHANCES LOOK TO MAKE A RETURN TO THE
CWA. THE LOW OVER THE PAC NW FINALLY STARTS TO SHIFT TO THE E/NE
INTO CENTRAL CANADA...BREAKING DOWN/SHIFTING THE RIDGE ONCE IN PLACE
OVER THE CENTRAL PLAINS...AND AGAIN ALLOWING FOR THE OPPORTUNITY FOR
DISTURBANCES IN THE MAIN FLOW TO BRING CHANCES FOR THUNDERSTORMS.
AS FAR AS TEMPERATURES GO...EXPECTING TO SEE A GRADUAL WARMING
TREND...MAINLY INTO THE FRI/SAT TIMEFRAME WITH THAT AMPLIFICATION OF
THE RIDGE...BEFORE MODERATING BACK DOWN A TOUCH INTO SUN/MON.
CURRENTLY HAVE HIGHS RISING TO THE 90S FOR BOTH FRI AND SAT
/ADDITION UPWARD ADJUSTMENTS MAY BE NEEDED/...WITH MID 80S TO MID
90S FOR SUN/MON.
&&
.AVIATION...(FOR THE 18Z KGRI TAF THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1235 PM CDT MON JUN 17 2013
ALTHOUGH CONFIDENCE REMAINS REASONABLY HIGH IN VFR
CEILING/VISIBILITY THROUGH THE NEXT 24 HOURS...CONFIDENCE IN
THUNDERSTORM TIMING/PROBABILITY OF OCCURRENCE REMAINS RATHER
MURKY IN THIS WEAKLY-FORCED NORTHWEST-FLOW PATTERN. ALTHOUGH HAVE
MAINTAINED SEVERAL HOURS OF VICINITY THUNDERSTORM MENTION TO AT
LEAST HINT AT THE POSSIBILITY OF OCCURRENCE...HAVE DELAYED THIS
MENTION TO THE EVENING/OVERNIGHT HOURS AND REMOVED FROM THIS
AFTERNOON. KEEP IN MIND THAT TEMPO/PREVAILING GROUPS WILL BE ADDED
IF CONFIDENCE INCREASES IN STORMS DIRECTLY AFFECTING KGRI...AS ANY
STORMS COULD CONTAIN GUSTY WINDS AS WELL. OTHERWISE...GENERALLY
LIGHT BREEZES UNDER 10KT WILL PREVAIL THROUGH THE
PERIOD...TRANSITIONING FROM NORTHEASTERLY TO SOUTHEASTERLY WITH
TIME. ALTHOUGH SUPPOSE LIGHT FOG WITH MVFR VISIBILITY CANNOT
COMPLETELY BE RULED OUT OVERNIGHT...WILL LEAVE IT VFR FOR NOW
GIVEN THE SEEMINGLY LOW PROBABILITY OF OCCURRENCE.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...PFANNKUCH
LONG TERM...ADO
AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1235 PM CDT MON JUN 17 2013
.UPDATE...
ISSUED AT 1055 AM CDT MON JUN 17 2013
FIRST FORECAST UPDATE OF THE DAY JUST COMPLETED. TO MAKE A LONG
STORY SHORT...AM GROWING LESS AND LESS IMPRESSED WITH THUNDERSTORM
POTENTIAL ESPECIALLY IN THE NOON-3 PM TIME FRAME...AS
INSTABILITY/FORCING FOR ROBUST EARLY-MID AFTERNOON DEVELOPMENT
EVEN JUST NORTHWEST OF THE CWA APPEARS TO BE CONSIDERABLY LACKING
COMPARED TO YESTERDAY. EVEN BY 21Z...THE LATEST RAP-ADVERTISED
0-1KM MLCAPE RANGES FROM BARELY ANYTHING IN EASTERN ZONES...MAYBE
AROUND 500-1000 J/KG CENTRAL...AND UP TO 1000-1500 J/KG...AND EVEN
THEN A BIT OF A CAP IS IN PLACE. FOR THE NEXT SEVERAL HOURS...WE
ARE LIKELY TO BE DOMINATED BY SUBSIDENCE IN THE WAKE OF DECENT
SHORTWAVE TROUGH DEPARTING THROUGH SOUTHEAST KS...WHILE WEAK
UPSTREAM WAVE CROSSING NORTHWEST/NORTH CENTRAL NEBRASKA IS
CURRENTLY HAVING TROUBLE GENERATING MORE THAN SPRINKLES/LIGHT
SHOWERS GIVEN MEAGER INSTABILITY. AT SOME POINT LATER THIS
AFTERNOON/EVENING...SOME ACTIVITY THAT DEVELOPS WEST-NORTHWEST OF
THE CWA COULD STILL MOVE IN AND BE STRONG/MARGINALLY SEVERE...BUT
AT LEAST FOR NOW AM GOING TO START DOWNPLAYING THE AFTERNOON HOURS
AND DELAY ANY MENTION OF STORMS UNTIL 20Z/3PM...AND EVEN THEN ONLY
20-30 PERCENT CHANCES THROUGH 00Z/7PM WITHIN ABOUT THE NORTHWEST
2/3 OF THE CWA. WILL REFINE THE EVENING/OVERNIGHT POPS IN LATER
UPDATES...BUT ITS WORTH NOTING THAT THE LATEST HRRR DOESN/T BRING
A SINGLE STORM INTO THE CWA UNTIL AFTER 01Z/8PM...AND EVEN THEN
ONLY FOR THE FAR NORTHWEST/WEST COUNTIES. THIS IS NO GUARANTEE
THOUGH...AS MODELS CONTINUE TO STRUGGLE WITH DETAILS IN THIS
PATTERN. OTHERWISE...MADE NO CHANGES WHATSOEVER TO HIGH TEMP
FORECAST AT THIS TIME...BUT DID LOWER DEWPOINTS A FEW DEGREES
BASED ON CURRENT TRENDS...WITH MANY CENTRAL/NORTHEAST COUNTIES
RUNNING DOWN IN THE UPPER 50S VERSUS 60S.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM CDT MON JUN 17 2013
OVERALL PATTERN TODAY IS RATHER SIMILAR TO YESTERDAY WITH AN UPPER
RIDGE CENTERED OVER THE ROCKIES...AND NORTHWESTERLY FLOW ALOFT
ACROSS THE PLAINS. WEAK EMBEDDED SHORT WAVES WILL CONTINUE TO TRACK
ACROSS THE PLAINS. THE 00Z ECMWF...00Z AND 06Z NAM...AND SEVERAL WFR RUNS
ONCE AGAIN INITIATE CONVECTION ACROSS THE NEBRASKA SANDHILLS BY
LATER THIS MORNING INTO EARLY THIS AFTERNOON. THIS CONVECTION SHOULD
TRACK SOUTHEAST WITH ADDITIONAL CONVECTIVE DEVELOPMENT PROPAGATING
TO THE SOUTHEAST THROUGH THE AFTERNOON. THIS WILL RESULT IN THE
CHANCE OF THUNDERSTORMS AGAIN FOR OUR AREA ESPECIALLY DURING THE
AFTERNOON WITH THE FOCUS BEING ONCE AGAIN ACROSS OUR WESTERN
ZONES...WEST OF HIGHWAY 281. THE HIGHEST POPS THIS AFTERNOON WILL BE
ACROSS OUR FAR WEST AND THEN DECREASE TO LOW END SLIGHT CHANCE POPS
ACROSS OUR NORTHEAST.
THUNDERSTORMS MAY NOT BE QUITE AS WIDESPREAD ACROSS OUR AREA
TODAY...BUT ANY STORMS THAT DO FORM OR MOVE INTO THE REGION WILL
CERTAINLY BE CAPABLE OF PRODUCING SEVERE WEATHER. ANY SEVERE WEATHER
SHOULD BE CONFINED TO THIS AFTERNOON AND EVENING WITH THE FOCUS ONCE
AGAIN BEING WEST OF HIGHWAY 281. INSTABILITY WILL AGAIN BE HIGH
TODAY WITH MLCAPE VALUES OF 2000 TO 2500 J/KG...AND 0-6 KM DEEP
LAYER SHEAR WILL BE ADEQUATE FOR SEVERE WEATHER AT 30 TO 40 KTS.
THERE IS ALSO LITTLE IF ANY CONVECTIVE INHIBITION BY EARLY AFTERNOON
AND THE QUESTION WILL BE CAN WE GET ENOUGH FORCING OR MOVE SOME
STORMS INTO OUR FAVORABLE ENVIRONMENT THIS AFTERNOON FROM THE
NORTHWEST. CURRENT THOUGHT IS THAT WE WILL HAVE AT LEAST A FEW
THUNDERSTORMS ACROSS THE AREA THIS AFTERNOON...PRIMARILY WESTERN
AREAS...BUT MAYBE A FEW LESS STORMS OVERALL THAN WE HAD YESTERDAY.
THUNDERSTORMS COULD LINGER INTO THE EVENING...BUT SHOULD DIE DOWN
FAIRLY QUICKLY AFTER SUNSET AS WE LOSE HEATING. HIGH TEMPERATURES
TODAY WILL BE SIMILAR TO YESTERDAY AND RANGE FROM THE LOWER TO MID
80S ACROSS NEBRASKA...TO THE MID AND UPPER 80S OVER NORTHERN KANSAS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 355 AM CDT MON JUN 17 2013
ALOFT: THE LONG-WAVE /LGWV/ RIDGE WILL HAVE RETROGRADED TO THE
ROCKIES BY 12Z/TUE. A CLOSED LOW WILL BE OFF THE PAC NW COAST. THE
RIDGE WILL BE SHOVED BACK OVER THE PLAINS WED-THU AS THE SLOW-MOVING
LOW ADVANCES INTO THE PAC NW. BY FRI THE LOW WILL ONLY HAVE ADVANCED
INTO SRN ALBERTA. THE LGWV RIDGE WILL BE OVER THE MID MS VALLEY AND
FAIRLY ZONAL W FLOW WILL BE OVER THE CNTRL PLAINS.
SFC: THE MEAN POLAR FRONT WILL BE NEAR I-70 AT 12Z/TUE AND GRADUALLY
SINK FURTHER S TUE-WED...AS THE ERN USA TROF MODESTLY DEEPENS. IN
THE MEANTIME...HIGH PRES WILL REMAIN PARKED OVER THE NE 1/4 OF THE
USA. THE TAIL END OF THE POLAR FRONT WILL LIFT BACK N INTO THE CNTRL
PLAINS WED NGT INTO THU...AS PRES FALLS AND A NEW LEE LOW FORMS OVER
CO. WHILE WE WILL PROBABLY SEE A LULL IN TSTM ACTIVITY /MOST LIKELY
TUE-WED/...TSTM ACTIVITY IS EXPECTED TO INCREASE AS THE FRONT LIFTS
BACK N WED NGT-THU...ALONG WITH THE LEADING EDGE OF A FRESH EML
ADVECTING OFF THE ELEVATED DESERTS/ ROCKIES. HOWEVER...BY FRI THE CO
LOW IS FCST TO EJECT NE ACROSS NEB TO MN. IT APPEARS THAT THE POLAR
FRONT WILL STALL ACROSS THE FCST AREA FRI-SUN WITH MULTIPLE WAVES OF
LOW PRES TRACKING NE ALONG THE FRONT. THE EML WILL PROBABLY CAP MOST
TSTM DEVELOPMENT S OF THE FRONT. MULTIPLE MCS COMPLEXES WILL OCCUR N
OF THE FRONT...MOST LIKELY FROM THE DAKOTAS INTO MN/IA/MO.
FCST CONFIDENCE: OVERALL BELOW AVERAGE DUE TO INHERENT UNCERTAINTY
ASSOCIATED WITH TSTMS AND THEIR ASSOCIATED EFFECTS IN THE MODELS.
THE DAILY DETAILS...
TUE: EXPECT SOME CLOUD DEBRIS FROM THE REMNANTS OF MON NGT TSTMS
OVER WRN KS/NEB. TSTMS WILL REDEVELOP OVER THOSE SAME AREAS AFTER 3
PM AND MAY EVENTUALLY DRIFT INTO PARTS OF THE FCST AREA W OF HWY 281.
NEAR NORMAL TEMPS BEHIND THE FRONT. 1-2F COOLER THAN PREVIOUS FCST.
TUE NGT-WED: THE GFS/EC BOTH HAVE WHAT APPEAR TO BE THE LEADING
SHRTWV TROF /ASSOCIATED WITH THE PAC NW CLOSE LOW/ MOVING THRU
HERE...SUGGESTING THAT SHWRS/TSTMS COULD BE POSSIBLE AT ANY TIME.
NEAR NORMAL TEMPS. 1-2F COOLER THAN PREVIOUS FCST.
WED NGT: POSSIBLE MCS DEVELOPMENT? 40 KT LLJ PUNCHES OVER THE
LIFTING WARM FRONT.
THU: SOME LINGERING MRNG RAIN SOMEWHERE? WE MAY HAVE TO DEAL WITH
PLENTY OF MRNG CLOUDS BEHIND A DEPARTING TSTM COMPLEX...IF IT
MATERIALIZES. THE AFTN SHOULD TURN SUNNY. N-CNTRL KS SHOULD BE BACK
IN THE 90S. TEMPS 3-5F ABOVE NORMAL.
FRI-SAT: MOST LIKELY CAPPED AND WE HEAT IT BACK UP. BEAVER CITY
NEB-STOCKTON KS BACK TO 100F? TEMPS 10F ABOVE NORMAL.
&&
.AVIATION...(FOR THE 18Z KGRI TAF THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1235 PM CDT MON JUN 17 2013
ALTHOUGH CONFIDENCE REMAINS REASONABLY HIGH IN VFR
CEILING/VISIBILITY THROUGH THE NEXT 24 HOURS...CONFIDENCE IN
THUNDERSTORM TIMING/PROBABILITY OF OCCURRENCE REMAINS RATHER
MURKY IN THIS WEAKLY-FORCED NORTHWEST-FLOW PATTERN. ALTHOUGH HAVE
MAINTAINED SEVERAL HOURS OF VICINITY THUNDERSTORM MENTION TO AT
LEAST HINT AT THE POSSIBILITY OF OCCURRENCE...HAVE DELAYED THIS
MENTION TO THE EVENING/OVERNIGHT HOURS AND REMOVED FROM THIS
AFTERNOON. KEEP IN MIND THAT TEMPO/PREVAILING GROUPS WILL BE ADDED
IF CONFIDENCE INCREASES IN STORMS DIRECTLY AFFECTING KGRI...AS ANY
STORMS COULD CONTAIN GUSTY WINDS AS WELL. OTHERWISE...GENERALLY
LIGHT BREEZES UNDER 10KT WILL PREVAIL THROUGH THE
PERIOD...TRANSITIONING FROM NORTHEASTERLY TO SOUTHEASTERLY WITH
TIME. ALTHOUGH SUPPOSE LIGHT FOG WITH MVFR VISIBILITY CANNOT
COMPLETELY BE RULED OUT OVERNIGHT...WILL LEAVE IT VFR FOR NOW
GIVEN THE SEEMINGLY LOW PROBABILITY OF OCCURRENCE.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...PFANNKUCH
SHORT TERM...WESELY
LONG TERM...HALBLAUB
AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
120 PM EDT MON JUN 17 2013
.SYNOPSIS...
THE THREAT FOR SHOWERS AND THUNDERSTORMS REMAINS UNTIL A COLD
FRONT ACROSS THE UPPER LAKES SINKS SOUTHWARD ACROSS NW PA AND NRN
OH TUESDAY. HIGH PRESSURE WILL TAKE ITS PLACE ACROSS THE GREAT
LAKES FOR THE REMAINDER OF THE WORK WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HAVE MADE JUST MINOR CHANGES TO THE FORECAST...MAINLY TO CLOUDS.
TEMPS SEEM ON TRACK. LATEST GUIDANCE INCLUDING HRRR CONTINUES TO
SHOW SHOWERS AND STORMS FIRING OVER LAKE ERIE LATE TODAY AND THEN
MOVING INLAND. WILL CONTINUE TO MONITOR.
PREVIOUS...STARTING TO GET SOME PATCHY FOG REPORTED IN THE OBS...MOST
NOTABLY WHERE THE MOST RAIN FELL YESTERDAY. HAVE ADDED A COUPLE OF
HOURS OF PATCHY FOR TO THE FORECAST GRIDS SINCE SOME OF THE
VISIBILITIES ARE BELOW A HALF MIL. AREA STABILIZED EARLY THIS
MORNING AND WITH NOTHING TO INITIATE A SHOWER/TS...MUCH OF THE
FIRST PART OF THE DAY IS EXPECTED TO REMAIN DRY. A FRONTAL
BOUNDARY STILL LINGERS JUST NORTH OF THE OHIO BORDER...DIVIDING
MID AND UPPER 60 DEWPOINTS TO ITS SOUTH FROM MID 50S DEWPOINTS TO
ITS NORTH...BUT IT IS MUCH LESS DEFINED THAN YESTERDAY. 00Z DTX
SOUNDING ALSO SHOWS THE RELATIVE DRYING THAT HAS TAKEN PLACE.
SHOULD NOT HAVE TO WORRY ABOUT SHRA/TS FOR A GOOD PART OF TODAY.
WILL BRING LOW PRECIP CHANCES INTO ERIE PA AFTER 2 PM AND INTO CLE
AFTER 5P AS INSTABILITY INCREASES AND FRONTAL ZONE ACROSS MI INTO
ONTARIO BEGINS TO DEVELOP SCATTERED CONVECTION. WITH THE GENERAL
WESTERLY FLOW...H8 TEMPS CREEP UP A COUPLE OF DEGREES FOR TODAY.
SO WILL TACK ON SOME FOR THE HIGHS. THIS WILL PUT NW OHIO SOLIDLY
INTO THE MID 80S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
UPPER TROUGH SHARPENS AND FRONTAL BOUNDARY WILL FINALLY START TO
SINK SOUTHWARD. SCATTERED CONVECTION EXPECTED ACROSS MI/ONTARIO
FOR THE LATE AFTERNOON AND THAT WILL BEGIN TO SEEP INTO NW PA/NRN
OHIO DURING THE EARLY EVENING. WILL MAXIMIZE PRECIP CHANCES THEN
IN THE EVENING...TAPERING THEM OVERNIGHT AS WE STABILIZE. FRONT
THOUGH WILL BE SLOW TO FLUSH THROUGH THE AREA AND WILL KEEP SOME
PRECIP CHANCES INLAND FOR TUESDAY. MILD AGAIN TONIGHT WITH 60S FOR
LOWS. TUESDAYS TEMPS WILL REMAIN MILD ACROSS THE SOUTH...BUT THE
EFFECTS OF COOLER AND DRIER HIGH PRESSURE ACROSS THE CENTRAL GREAT
LAKES WILL BEGIN TO OVERSPREAD THE LAKESHORE.
GOOD MODEL CONSENSUS FOR A DRY PERIOD WITH HIGH PRESSURE DOMINANT
FOR TUESDAY NIGHT THROUGH THURSDAY NIGHT. HIGHS WILL SLIP BACK
SLIGHTLY BELOW NORMAL AND NIGHTS AGAIN WILL GET INTO THE LOWER
50S...WITH A FEW UPPER 40S POSSIBLE. AMPLE SUN AND CLEARING
THROUGH THE PERIOD.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
GFS AND ECMWF SHOWING A DEVELOPING UPPER RIDGE ACROSS THE SOUTH
CENTRAL AND SOUTHEASTERN STATES INTO THE OHIO VALLEY LATE WEEK AND
INTO THE WEEKEND WHICH MEANS ON BALANCE...A BIT MORE HEAT IN THE
REGION. FRIDAY MODELS SHOW A SURFACE HIGH ACROSS THE GREAT LAKES AND
OHIO VALLEY WITH LOW PRESSURE IN KS/NE. GIVEN THE SURFACE HIGH IN
THE REGION WENT WITH A DRY FORECAST FOR THE DAY. HUMIDITY WILL BE
INCREASING SATURDAY INTO SUNDAY AS THE BOTH THE HIGH AND LOW DRIFT
EAST SETTING UP A SOUTHERLY CONVEYOR OUT OF THE GLFMX. SUNDAY THE
LOW WILL BE IN THE AREA WITH A WARM FRONT TO OUR EAST AND A TRAILING
COLD FRONT WEST. EXPECTING A DECENT SHOT OF AFTERNOON/EVENING
SHOWERS/THUNDERSTORMS SATURDAY AND SUNDAY ALTHOUGH WITH THE UPPER
HIGH ALSO NOSING INTO THE AREA WILL HOLD POPS TO THE CHANCE
CATEGORY. EXPECT HIGHS FROM THE LOW TO MID 80S.
&&
.AVIATION /17Z MONDAY THROUGH FRIDAY/...
EXPECT SCATTERED SHOWERS WITH A FEW TSRA THIS AFTERNOON AND
EVENING. LEADING EDGE OF WEAK COLD FRONT JUST SOUTH OF THE ERIE
LAKESHORE. MODERATE INSTABILITY SOUTH OF THE FRONT WITH CAPES OVER
2,000 J/KG BUT NOT ALOT OF LIFT OR SHEAR. MODELS DEVELOP MORE
PREIP AHEAD OF SECONDARY TROUGH ACROSS CENTRAL MICHIGAN THIS
AFTERNOON...WHICH MOVES ACROSS NRN OH/NW PA OVERNIGHT. LOW
CONFIDENCE HOW WIDESPREAD SHOWERS/TSRA WILL BE OVERNIGHT.
.OUTLOOK...MAINLY VFR EXCEPT FOR EARLY MORNING MIST/FOG.
&&
.MARINE...
WEAK STATIONARY FRONT ALONG THE SOUTH SHORE OF LAKE ERIE EARLY TODAY
WILL BEGIN TO DRIFT SOUTH THROUGH THE MORNING AS ANOTHER COLD FRONT
DROPS ACROSS THE CENTRAL LAKES TOWARD THE AREA. THIS SECOND FRONT
WILL MOVE ACROSS THE LAKE THIS EVENING. HIGH PRESSURE WILL
FOLLOW...BUILDING ACROSS THE CENTRAL GREAT LAKES TUESDAY THROUGH
THURSDAY. THE HIGH WILL DRIFT TO NEW ENGLAND ON FRIDAY. EXPECTING
SOUTHWEST WINDS ON THE LAKE TODAY AHEAD OF THE COLD FRONT. WINDS
WILL TURN NORTH TONIGHT AND THEN NORTHEAST FOR TUESDAY. WITH THE
HIGH TO OUR NORTH...WINDS WILL REMAIN FROM THE NORTHEAST FROM
TUESDAY THROUGH WEDNESDAY NIGHT OR THURSDAY BEFORE SHIFTING EAST TO
SOUTHEAST FRIDAY. NOT EXPECTING WINDS OR WAVES TO GET HIGH ENOUGH
FOR A SMALL CRAFT ADVISORY THROUGH THE PERIOD HOWEVER THE
NORTHEAST FLOW WILL MAKE A 2 TO 3 FOOT CHOP ON THE CENTRAL AND
WEST THIRD NEARSHORE WATERS MIDWEEK.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...OUDEMAN
NEAR TERM...KUBINA/OUDEMAN
SHORT TERM...OUDEMAN
LONG TERM...TK
AVIATION...DJB
MARINE...TK
AREA FORECAST DISCUSSION
NWS AMARILLO TX
412 PM CDT MON JUN 17 2013
.UPDATE...
SEVERE THUNDERSTORM WATCH NUMBER 323 HAS BEEN ISSUED FOR THE CENTRAL
AND WESTERN TEXAS AND OKLAHOMA PANHANDLES UNTIL 11 PM. PRIMARY
THREATS WILL BE LARGE HAIL AND DAMAGING WIND. DUE TO SATURATED SOILS
AND HEAVY RAIN POTENTIAL...THERE WILL ALSO BE A LOCALIZED AND FLASH
FLOODING THREAT. UPDATED TEXT PRODUCTS HAVE BEEN ISSUED.
&&
.PREV DISCUSSION... /ISSUED 312 PM CDT MON JUN 17 2013/
DISCUSSION...
TODAY AND TOMORROW REMAIN ACTIVE DAYS FOR THE TEXAS AND OKLAHOMA
PANHANDLES. TEMPERATURES WERE SLOW TO COME UP THIS MORNING BUT HAVE
BEGUN TO QUICKLY RISE ACROSS THE AREA. THERE WAS SOME CONCERN THAT
THE SLOW HEATING WOULD DELAY INITIATION OF STORMS THIS AFTERNOON
HOWEVER VISIBLE SATELLITE IMAGERY IS SHOWING A MILD CU FIELD
DEVELOPING ACROSS THE EASTERN HALF OF THE PANHANDLES. ALSO
CONVECTION OVER THE NEW MEXICO MOUNTAINS HAS INITIATED ONLY ABOUT A
HOUR BEHIND WHAT WAS SHOWN IN THE 14Z RUC HRRR. AS SUCH THE PREVIOUS
FORECAST SEVERE THREAT START TIME OF 6 PM REMAINS REALISTIC. WILL
PAY CLOSE ATTENTION TO THE DEVELOPING CONVECTION ALONG THE RED RIVER
AS IT COULD BACK BUILD ALONG A SOUTHWARD PROGRESSING COLD FRONT INTO
COLLINGSWORTH COUNTY PRIOR TO 6 PM. THE SEVERE THREAT WILL LAST
UNTIL 2-3AM TUESDAY WHEN STRONG CAPPING WILL SETUP
HOWEVER...PRECIPITATION MAY LAST WELL PAST 3 AM.
SPC MESO ANALYSIS HAS SHOWN A CONTINUAL DECREASING TREND OF CIN
VALUES ACROSS THE WESTERN TEXAS AND OKLAHOMA PANHANDLES DURING THE
SAME TIME SHOWING AN INCREASE OF SBCAPE VALUES. FORECAST SBCAPE
VALUES OF 1500-2500 J/KG WITH DEEP LAYER SHEAR OF 35-40 KT CONTINUE
SUPPORT LARGE HAIL AND DAMAGING WIND AS THE PRIMARY SEVERE HAZARDS.
GIVEN SLOW STORM MOTIONS OF 15 TO 20 KTS...MOIST SOILS FROM PREVIOUS
RAINS...AND PWAT VALUES NEAR AN INCH WILL KEEP LOCALIZED AND FLASH
FLOODING AS A CONCERN WITH THESE STORMS.
TOMORROW MODELS CONTINUE TO ADVERTISE REDEVELOPMENT OF STORMS ACROSS
THE PANHANDLE. CAPE VALUES OF 1000-2000 J/KG AND DEEP SHEAR OF 35-45
KT WILL KEEP THE RISK OF SEVERE STORMS ACROSS THE PANHANDLES YET
AGAIN. THE TIME FRAME FOR STORMS TO DEVELOP WILL BE AROUND 4 PM WITH
SEVERE POTENTIAL MAXIMIZING AFTER 6 PM. STORM WILL CONTINUE THROUGH
MOST OF THE NIGHT BUT THE SEVERE RISK SHOULD SUBSIDE AFTER 3 AM.
WEDNESDAY THROUGH THE WEEKEND...UPPER LEVEL RIDGING WILL RETURN TO
THE PANHANDLES AND KEEP PRECIPITATION CHANCES LIMITED. THE RIDGE AXIS
WILL MEANDER TO THE EAST AND BACK TO THE WEST WHICH WILL OPEN UP THE
CHANCE FOR SOME PRECIP BUT HAVE KEPT THE FORECAST DRY GIVEN THE
UNCERTAINTY ON THE AXIS PLACEMENT THIS FAR OUT.
FIRE WEATHER...
NEITHER ELEVATED NOR FIRE WEATHER CONDITIONS ARE EXPECTED FOR THE
NEXT 7 DAYS GIVEN THE RECENT WETTING RAINS.
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
15/14
AREA FORECAST DISCUSSION
NWS AMARILLO TX
312 PM CDT MON JUN 17 2013
.DISCUSSION...
TODAY AND TOMORROW REMAIN ACTIVE DAYS FOR THE TEXAS AND OKLAHOMA
PANHANDLES. TEMPERATURES WERE SLOW TO COME UP THIS MORNING BUT HAVE
BEGUN TO QUICKLY RISE ACROSS THE AREA. THERE WAS SOME CONCERN THAT
THE SLOW HEATING WOULD DELAY INITIATION OF STORMS THIS AFTERNOON
HOWEVER VISIBLE SATELLITE IMAGERY IS SHOWING A MILD CU FIELD
DEVELOPING ACROSS THE EASTERN HALF OF THE PANHANDLES. ALSO
CONVECTION OVER THE NEW MEXICO MOUNTAINS HAS INITIATED ONLY ABOUT A
HOUR BEHIND WHAT WAS SHOWN IN THE 14Z RUC HRRR. AS SUCH THE PREVIOUS
FORECAST SEVERE THREAT START TIME OF 6 PM REMAINS REALISTIC. WILL
PAY CLOSE ATTENTION TO THE DEVELOPING CONVECTION ALONG THE RED RIVER
AS IT COULD BACK BUILD ALONG A SOUTHWARD PROGRESSING COLD FRONT INTO
COLLINGSWORTH COUNTY PRIOR TO 6 PM. THE SEVERE THREAT WILL LAST
UNTIL 2-3AM TUESDAY WHEN STRONG CAPPING WILL SETUP
HOWEVER...PRECIPITATION MAY LAST WELL PAST 3 AM.
SPC MESO ANALYSIS HAS SHOWN A CONTINUAL DECREASING TREND OF CIN
VALUES ACROSS THE WESTERN TEXAS AND OKLAHOMA PANHANDLES DURING THE
SAME TIME SHOWING AN INCREASE OF SBCAPE VALUES. FORECAST SBCAPE
VALUES OF 1500-2500 J/KG WITH DEEP LAYER SHEAR OF 35-40 KT CONTINUE
SUPPORT LARGE HAIL AND DAMAGING WIND AS THE PRIMARY SEVERE HAZARDS.
GIVEN SLOW STORM MOTIONS OF 15 TO 20 KTS...MOIST SOILS FROM PREVIOUS
RAINS...AND PWAT VALUES NEAR AN INCH WILL KEEP LOCALIZED AND FLASH
FLOODING AS A CONCERN WITH THESE STORMS.
TOMORROW MODELS CONTINUE TO ADVERTISE REDEVELOPMENT OF STORMS ACROSS
THE PANHANDLE. CAPE VALUES OF 1000-2000 J/KG AND DEEP SHEAR OF 35-45
KT WILL KEEP THE RISK OF SEVERE STORMS ACROSS THE PANHANDLES YET
AGAIN. THE TIME FRAME FOR STORMS TO DEVELOP WILL BE AROUND 4 PM WITH
SEVERE POTENTIAL MAXIMIZING AFTER 6 PM. STORM WILL CONTINUE THROUGH
MOST OF THE NIGHT BUT THE SEVERE RISK SHOULD SUBSIDE AFTER 3 AM.
WEDNESDAY THROUGH THE WEEKEND...UPPER LEVEL RIDGING WILL RETURN TO
THE PANHANDLES AND KEEP PRECIPITATION CHANCES LIMITED. THE RIDGE AXIS
WILL MEANDER TO THE EAST AND BACK TO THE WEST WHICH WILL OPEN UP THE
CHANCE FOR SOME PRECIP BUT HAVE KEPT THE FORECAST DRY GIVEN THE
UNCERTAINTY ON THE AXIS PLACEMENT THIS FAR OUT.
&&
.FIRE WEATHER...
NEITHER ELEVATED NOR FIRE WEATHER CONDITIONS ARE EXPECTED FOR THE
NEXT 7 DAYS GIVEN THE RECENT WETTING RAINS.
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
15/14
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
106 PM CDT MON JUN 17 2013
.AVIATION...
/18Z TAFS/
SEVERAL CHALLENGES ARE IN PLAY WITH THE 24 HOUR FORECAST AFTER
OVERNIGHT MCS SWEPT THROUGH NORTH TEXAS THIS MORNING. A WEAK COLD
FRONT IS EXPECTED TO MOVE ACROSS THE RED RIVER JUST BEFORE 00Z
WITH SCATTERED STORMS DEVELOPING AHEAD OF THE FRONT. ANOTHER
SHORTWAVE HELPS DEVELOP A POSSIBLE MCS OVER WEST-CENTRAL TX AND
LOOKS TO ARRIVE FROM THE WEST LATE EVENING INTO THE PREDAWN HOURS
TUESDAY. TIMING UNCERTAINTIES ABOUND WITH REGARD TO CONVECTIVE
TRENDS AND THE MODELS CONTINUE TO STRUGGLE WITH OVER EVOLUTION.
IN ADDITION...WIND SHIFTS AND SPEEDS ASSOCIATED WITH THE COLD
FRONT AT DFW METRO AIRPORTS REMAINS PROBLEMATIC...AS DOES A BRIEF
WINDOW FOR MVFR CIGS AROUND/AFTER ANY MCS.
ISOLATED-SCATTERED STORMS SHOULD DEVELOP ALONG THE FRONT AND NORTH
OF I-20...WEST TOWARD AN AREA OF HIGHER INSTABILITY NEAR A SURFACE
LOW AROUND ABILENE. BEST CONSENSUS TIMING FROM THE MODELS FOR
VCTS/CB IS BETWEEN 22Z-01Z AT METRO AIRPORTS FOR ACTIVITY NEAR THE
COLD FRONT. THE OTHER WINDOW WILL BE BETWEEN 06Z-12Z FOR THE
POTENTIAL MCS AT ALL AIRPORTS INCLUDING WACO. HAVE LEFT WACO OUT
FOR ANY EARLY EVENING STORMS CONSIDERING THE WEAKER FORCING AND
STRONGER SUBSIDENCE OVER CENTRAL TEXAS LATER THIS AFTERNOON. THERE
WILL LIKELY BE SEVERAL ADJUSTMENTS TO TIMING AND THREATS THROUGH
TONIGHT WHEN CONFIDENCE BECOMES HIGHER ON THE OVERALL EVOLUTION OF
SHOWERS/STORMS.
LIGHT SOUTH-SOUTHWEST FLOW WILL PREVAIL...THOUGH A SHIFT TO WEAK
N/NE FLOW IS EXPECTED WITH THE COLD FRONT SINKING SOUTH ACROSS THE
METRO AIRPORTS BY THIS EVENING. BEST WINDOW FOR MVFR CIGS WILL BE
JUST BEFORE SUNRISE THROUGH MID MORNING TUESDAY.
05/
&&
.UPDATE...
OUTFLOW BOUNDARY FROM COMPLEX OF STORMS THAT MOVED THROUGH THE
AREA EARLIER THIS MORNING CONTINUES TO MOVE SOUTHEAST INTO
PORTIONS OF CENTRAL AND SOUTHEAST TEXAS. SHOWERS AND THUNDERSTORMS
ARE FORMING ALONG THE BOUNDARY BRINGING SOME RAIN TO OUR
SOUTHEASTERN COUNTIES. DEPENDING ON WHERE THIS BOUNDARY
STALLS...IT WILL LIKELY BE A FOCUS FOR POSSIBLE THUNDERSTORM
DEVELOPMENT THIS AFTERNOON. IN ADDITION...THE FRONT WILL BE
APPROACHING AND/OR CROSSING THE RED RIVER LATE THIS
AFTERNOON...PROVIDING ANOTHER FOCUS FOR THUNDERSTORM DEVELOPMENT.
AND FINALLY...SOME ATTENTION WILL ALSO BE GIVEN TO OUR WESTERN
COUNTIES WHERE INSTABILITY AND HEATING WILL ALIGN FOR A THIRD
POTENTIAL REGION OF THUNDERSTORM DEVELOPMENT. ANY STORMS THAT FORM
THIS AFTERNOON WILL BE ISOLATED TO SCATTERED IN NATURE BUT A FEW
STRONG TO MARGINALLY SEVERE STORMS WILL BE POSSIBLE. GUSTY WINDS
AND HEAVY RAINFALL WILL BE THE MAIN THREATS BUT SOME SMALL HAIL IS
ALSO POSSIBLE.
FOR THE AFTERNOON HOURS...UPDATED THE FORECAST TO CARRY 30 POPS
ACROSS THE REGION WITH 40 POPS NEAR THE RED RIVER. FOR THIS
EVENING AND OVERNIGHT...SOME OF THE SHORT-TERM HI-RES MODELS
CONTINUE TO INDICATE A COMPLEX OF STORMS DEVELOPING IN WEST TEXAS
AND POSSIBLY REACHING PORTIONS OF NORTH TEXAS OVERNIGHT OR TUESDAY
MORNING. WILL MAINTAIN HIGHEST POPS OVERNIGHT OVER THE WESTERN
COUNTIES BUT CHANGES MAY BE NEEDED WITH THE AFTERNOON FORECAST
PACKAGE.
82/JLD
&&
.PREV DISCUSSION... /ISSUED 353 AM CDT MON JUN 17 2013/
A LARGE MCS WILL CONTINUE MOVING SOUTHEAST TOWARD NORTH TEXAS
EARLY THIS MORNING AND SHOULD REACH THE NORTHWEST ZONES SHORTLY
BEFORE 6 AM AS PER THE HRRR AND 4KM WRF SOLUTIONS AS WELL AS LINEAR
EXTRAPOLATION. THE COMPLEX SHOULD WEAKEN AS IT MOVES FARTHER AWAY
FROM ITS UPPER SUPPORT AND ALSO ONCE A 30 KNOT LOW LEVEL JET
DECREASES LATER THIS MORNING. THIS SOLUTION IS ALSO SUPPORTED BY
THE HRRR AND 4KM WRF. WE STILL EXPECT EXTENSIVE CLOUD COVER AND
SCATTERED TO NUMEROUS STORMS...THROUGH THE MORNING WITH THE
EXPECTED TIME OF ARRIVAL OF STORMS AT THE METROPLEX BETWEEN 13 AND
15Z. SOME IMPRESSIVE WIND GUSTS BETWEEN 50 AND 55 KNOTS ARE
OCCURRING WITH THE COMPLEX. IT IS VERY POSSIBLE THAT SOME SIMILAR
WIND GUSTS COULD OCCUR ACROSS THE NORTHWEST CWA BY 6 AM. EXPECT
STORMS TO BECOME LESS ORGANIZED BY MIDDAY AND AFFECT MAINLY THE
EAST/NORTHEAST ZONES.
MODELS ARE CONSISTENT ON DEVELOPING MORE STORMS ACROSS WEST TEXAS ALONG
A FAST MOVING SHORT WAVE AND COLD FRONT LATE THIS AFTERNOON. AM A
BIT CONCERNED THAT EXTENSIVE OVERNIGHT/MORNING CONVECTION MAY
HINDER STORM DEVELOPMENT THIS AFTERNOON. HOWEVER...THE ATMOSPHERE
MAY HAVE JUST ENOUGH TIME TO RECOVER BEFORE SURFACE HEATING IS
LOST. STORMS SHOULD ORGANIZE ALONG THE COLD FRONT AND MOVE
SOUTHEAST INTO NORTH TEXAS TONIGHT/TUESDAY MORNING. AGAIN...WILL
KEEP THE HIGHEST POPS ACROSS THE NORTHERN ZONES. THE COLD FRONT IS
PROGGED TO STALL ACROSS THE NORTHERN HALF OF THE REGION TUESDAY
NIGHT AND LIFT NORTH OF THE RED RIVER BY WEDNESDAY EVENING.
AFTER WEDNESDAY...UPPER LEVEL HIGH PRESSURE WILL BUILD FROM
TEXAS...NORTHWARD THROUGH THE CENTRAL PLAINS. THIS PATTERN WILL
RESULT IN HOT TEMPERATURES AND LITTLE RAIN CHANCES WEDNESDAY NIGHT
THROUGH EARLY NEXT WEEK. EXPECT AFTERNOON HIGHS THROUGH EARLY NEXT
WEEK MAINLY IN THE LOWER AND MIDDLE 90S...EXPERT FOR SOME UPPER
90S IN THE WEST. OVERNIGHT LOWS WILL BE IN THE 70S THROUGH EARLY
NEXT WEEK.
79
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 89 77 92 75 95 / 30 30 30 20 20
WACO, TX 91 75 93 74 94 / 30 40 20 20 10
PARIS, TX 87 73 87 72 88 / 40 30 40 40 40
DENTON, TX 88 75 92 73 94 / 40 30 40 30 20
MCKINNEY, TX 88 73 90 73 92 / 40 30 40 30 20
DALLAS, TX 90 77 92 76 93 / 30 30 30 20 20
TERRELL, TX 88 75 91 73 92 / 60 30 30 20 20
CORSICANA, TX 91 74 91 74 92 / 60 40 20 20 10
TEMPLE, TX 95 72 92 73 92 / 30 40 20 10 10
MINERAL WELLS, TX 90 72 92 71 95 / 30 40 30 20 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
05/82
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
1110 AM CDT MON JUN 17 2013
.UPDATE...
OUTFLOW BOUNDARY FROM COMPLEX OF STORMS THAT MOVED THROUGH THE
AREA EARLIER THIS MORNING CONTINUES TO MOVE SOUTHEAST INTO
PORTIONS OF CENTRAL AND SOUTHEAST TEXAS. SHOWERS AND THUNDERSTORMS
ARE FORMING ALONG THE BOUNDARY BRINGING SOME RAIN TO OUR
SOUTHEASTERN COUNTIES. DEPENDING ON WHERE THIS BOUNDARY
STALLS...IT WILL LIKELY BE A FOCUS FOR POSSIBLE THUNDERSTORM
DEVELOPMENT THIS AFTERNOON. IN ADDITION...THE FRONT WILL BE
APPROACHING AND/OR CROSSING THE RED RIVER LATE THIS
AFTERNOON...PROVIDING ANOTHER FOCUS FOR THUNDERSTORM DEVELOPMENT.
AND FINALLY...SOME ATTENTION WILL ALSO BE GIVEN TO OUR WESTERN
COUNTIES WHERE INSTABILITY AND HEATING WILL ALIGN FOR A THIRD
POTENTIAL REGION OF THUNDERSTORM DEVELOPMENT. ANY STORMS THAT FORM
THIS AFTERNOON WILL BE ISOLATED TO SCATTERED IN NATURE BUT A FEW
STRONG TO MARGINALLY SEVERE STORMS WILL BE POSSIBLE. GUSTY WINDS
AND HEAVY RAINFALL WILL BE THE MAIN THREATS BUT SOME SMALL HAIL IS
ALSO POSSIBLE.
FOR THE AFTERNOON HOURS...UPDATED THE FORECAST TO CARRY 30 POPS
ACROSS THE REGION WITH 40 POPS NEAR THE RED RIVER. FOR THIS
EVENING AND OVERNIGHT...SOME OF THE SHORT-TERM HI-RES MODELS
CONTINUE TO INDICATE A COMPLEX OF STORMS DEVELOPING IN WEST TEXAS
AND POSSIBLY REACHING PORTIONS OF NORTH TEXAS OVERNIGHT OR TUESDAY
MORNING. WILL MAINTAIN HIGHEST POPS OVERNIGHT OVER THE WESTERN
COUNTIES BUT CHANGES MAY BE NEEDED WITH THE AFTERNOON FORECAST
PACKAGE.
82/JLD
&&
.PREV UPDATE...
.UPDATE...
A COMPLEX OF THUNDERSTORMS CONTINUES TO WEAKEN AS IT PROGRESSES
THROUGH ROUGHLY THE EASTERN HALF OF THE CWA. GUSTY WINDS TO 30-40
MPH MAY STILL OCCUR ALONG THE LEADING EDGE BUT OTHERWISE BRIEF
HEAVY RAINFALL AND LIGHTNING STRIKES WILL BE THE MAIN THREATS.
HAVE UPDATED THE FORECAST TO REFLECT THE LATEST RADAR...TEMP...SKY
TRENDS FOR THE NEXT FEW HOURS. ALSO DECREASED AFTERNOON
TEMPERATURES A FEW DEGREES FOR NOW AND WILL LOOK AT TEMPS AGAIN
THROUGH THE MORNING HOURS.
WE ARE STILL WORKING TO EVALUATE PRECIPITATION CHANCES AND TRENDS
FOR THE REMAINDER OF THE DAY AND TONIGHT. THERE IS ALREADY
DISCREPANCIES AMONG THE MODELS ON PRECIP EVOLUTION LATER TODAY AND
NOW THE COMPLEX OF THUNDERSTORMS THIS MORNING WILL LIKELY ALSO
EFFECT TRENDS. WILL LIKELY BE ISSUING ANOTHER UPDATE BY MIDDAY
AFTER TAKING A CLOSER LOOK AND EVALUATING THE 12Z/LATEST MODEL
DATA.
82/JLD
&&
.PREV DISCUSSION... /ISSUED 353 AM CDT MON JUN 17 2013/
A LARGE MCS WILL CONTINUE MOVING SOUTHEAST TOWARD NORTH TEXAS
EARLY THIS MORNING AND SHOULD REACH THE NORTHWEST ZONES SHORTLY
BEFORE 6 AM AS PER THE HRRR AND 4KM WRF SOLUTIONS AS WELL AS LINEAR
EXTRAPOLATION. THE COMPLEX SHOULD WEAKEN AS IT MOVES FARTHER AWAY
FROM ITS UPPER SUPPORT AND ALSO ONCE A 30 KNOT LOW LEVEL JET
DECREASES LATER THIS MORNING. THIS SOLUTION IS ALSO SUPPORTED BY
THE HRRR AND 4KM WRF. WE STILL EXPECT EXTENSIVE CLOUD COVER AND
SCATTERED TO NUMEROUS STORMS...THROUGH THE MORNING WITH THE
EXPECTED TIME OF ARRIVAL OF STORMS AT THE METROPLEX BETWEEN 13 AND
15Z. SOME IMPRESSIVE WIND GUSTS BETWEEN 50 AND 55 KNOTS ARE
OCCURRING WITH THE COMPLEX. IT IS VERY POSSIBLE THAT SOME SIMILAR
WIND GUSTS COULD OCCUR ACROSS THE NORTHWEST CWA BY 6 AM. EXPECT
STORMS TO BECOME LESS ORGANIZED BY MIDDAY AND AFFECT MAINLY THE
EAST/NORTHEAST ZONES.
MODELS ARE CONSISTENT ON DEVELOPING MORE STORMS ACROSS WEST TEXAS ALONG
A FAST MOVING SHORT WAVE AND COLD FRONT LATE THIS AFTERNOON. AM A
BIT CONCERNED THAT EXTENSIVE OVERNIGHT/MORNING CONVECTION MAY
HINDER STORM DEVELOPMENT THIS AFTERNOON. HOWEVER...THE ATMOSPHERE
MAY HAVE JUST ENOUGH TIME TO RECOVER BEFORE SURFACE HEATING IS
LOST. STORMS SHOULD ORGANIZE ALONG THE COLD FRONT AND MOVE
SOUTHEAST INTO NORTH TEXAS TONIGHT/TUESDAY MORNING. AGAIN...WILL
KEEP THE HIGHEST POPS ACROSS THE NORTHERN ZONES. THE COLD FRONT IS
PROGGED TO STALL ACROSS THE NORTHERN HALF OF THE REGION TUESDAY
NIGHT AND LIFT NORTH OF THE RED RIVER BY WEDNESDAY EVENING.
AFTER WEDNESDAY...UPPER LEVEL HIGH PRESSURE WILL BUILD FROM
TEXAS...NORTHWARD THROUGH THE CENTRAL PLAINS. THIS PATTERN WILL
RESULT IN HOT TEMPERATURES AND LITTLE RAIN CHANCES WEDNESDAY NIGHT
THROUGH EARLY NEXT WEEK. EXPECT AFTERNOON HIGHS THROUGH EARLY NEXT
WEEK MAINLY IN THE LOWER AND MIDDLE 90S...EXPERT FOR SOME UPPER
90S IN THE WEST. OVERNIGHT LOWS WILL BE IN THE 70S THROUGH EARLY
NEXT WEEK.
79
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 89 77 92 75 95 / 30 30 30 20 20
WACO, TX 91 75 93 74 94 / 30 40 20 20 10
PARIS, TX 87 73 87 72 88 / 40 30 40 40 40
DENTON, TX 88 75 92 73 94 / 40 30 40 30 20
MCKINNEY, TX 88 73 90 73 92 / 40 30 40 30 20
DALLAS, TX 90 77 92 76 93 / 30 30 30 20 20
TERRELL, TX 88 75 91 73 92 / 60 30 30 20 20
CORSICANA, TX 91 74 91 74 92 / 60 40 20 20 10
TEMPLE, TX 95 72 92 73 92 / 30 40 20 10 10
MINERAL WELLS, TX 90 72 92 71 95 / 30 40 30 20 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
05/82
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1056 AM PDT Mon Jun 17 2013
.SYNOPSIS...
An increasing chance of showers and thunderstorms comes to the
Inland Northwest today through Tuesday. By Wednesday downright wet
and cool weather envelopes the region. Expect a gradual cool down
starting today, with afternoon temperatures bottoming out well
below normal by Wednesday. Showery, cool conditions will continue
through the week, with a drying and warming trend by the weekend.
&&
.DISCUSSION...
Updates may occur before the 3 PM afternoon zone issuance as a
number of recent HRRR runs have a persistent trend in forming very
fast moving elevated convection across the far western part of the
forecast area starting near 4 pm and on through the evening.
Otherwise to complicated the matter elevated convective showers
from last night along with new surface based convection should
continue to clutter primarily the northern third of the forecast
area. Best way to convey this situation is probably with the
description above rather than point probabilities and forecast zone
wording. 12Z KOTX sounding shows storm motion to the northeast at
15 mph or so for surface based convection but the elevated type
near the west side of the forecast area should move faster to the
northeast at near 35 mph or so (per quick view of GFS 1-6KM AGL
mean wind-speed for 00Z Tuesday). Any thunderstorms that form
should be of the weak pulse variety. /Pelatti
&&
.AVIATION...
18z TAFS: Low pressure off the coast next to inland ridge of high
pressure will allow a somewhat warm and unstable flow from the
south to allow for the possibility of convective showers and
thunderstorms for TAF sites. Surface based showers and
thunderstorms should occur primarily over the Mountains to the
north of Northeast Washington and North Idaho while elevated
showers and thunderstorms should occur after 00Z Tuesday and on
through the evening and overnight, possibly lingering on as
various disturbances move up from the south and on into 18Z
Tuesday. /Pelatti
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 82 56 75 50 58 46 / 20 50 50 80 100 70
Coeur d`Alene 81 55 75 51 55 46 / 20 50 50 80 100 80
Pullman 81 50 72 47 59 43 / 10 20 50 70 90 70
Lewiston 88 57 82 54 66 49 / 10 20 40 70 70 70
Colville 83 53 79 50 60 47 / 30 50 60 80 100 80
Sandpoint 82 52 81 49 56 44 / 30 50 50 90 100 80
Kellogg 79 55 80 50 54 44 / 20 20 40 90 100 80
Moses Lake 86 57 75 54 66 50 / 10 50 50 50 60 40
Wenatchee 83 60 74 56 64 52 / 20 40 60 40 60 40
Omak 83 54 77 52 65 49 / 20 40 70 60 100 60
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1255 PM CDT MON JUN 17 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 307 AM CDT MON JUN 17 2013
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED AN UPPER LOW OFF THE PACIFIC NORTHWEST COAST...RIDGING
BUILDING FROM NEW MEXICO INTO BRITISH COLUMBIA...AND TROUGHING OVER
SOUTHEAST CANADA INTO THE EASTERN GREAT LAKES. WITHIN THE
WEST-NORTHWEST FLOW...TWO SHORTWAVES OF NOTE WERE NEAR FARGO NORTH
DAKOTA AND IN FAR SOUTHWEST SASKATCHEWAN. 700-850MB MOISTURE
TRANSPORT AHEAD OF THE FARGO SHORTWAVE HELPING TO SUPPORT SOME HIGH
BASED SHOWERS ALONG/NORTHEAST OF I-94. TALKING ABOUT HIGH BASED...
00Z MPX AND GRB SOUNDINGS BOTH DEPICTED MIXING UP TO 750MB...WITH
DEEP INVERTED-V APPEARANCE BELOW. THIS DEEP MIXING ALLOWED FOR
SHOWERS THAT MOVED THROUGH MPX AROUND RAOB RELEASE TIME TO PRODUCE
WIND GUSTS OF 30-50KT. THESE SHOWERS WERE MORE VIGOROUS THEN THOSE
OCCURRING NOW...PLUS THEY OCCURRED RIGHT AFTER PEAK HEATING WHEN
MIXING WAS AT ITS MAXIMUM...ALLOWING FOR THE STRONG GUST POTENTIAL.
OTHERWISE...SKIES ARE MOSTLY CLEAR OVER THE FORECAST AREA SOUTH OF A
COLD FRONT EXTENDING FROM NORTHERN MN INTO NORTHERN LOWER MI. 850MB
TEMPS AT 00Z AHEAD OF THE FRONT WERE 14-16C AT MPX...GRB AND
DVN...COMPARED TO 4C BEHIND THE FRONT UP AT PICKLE LAKE IN NORTHWEST
ONTARIO. ALTHOUGH DEEP MIXING EXISTED ON THAT MPX SOUNDING...THE
HIGHER MID LEVEL MOISTURE ALLOWED FOR THE PRECIPITABLE WATER TO JUMP
UP TO 0.93 INCHES AS OF 00Z...COMPARED TO 0.44 12 HOURS EARLIER.
THUS...THERE IS SOME MOISTURE AHEAD OF THE FARGO SHORTWAVE.
MODEL TRENDS FOR TODAY HAVE REALLY SHIFTED THE SHORTWAVE COMING INTO
THE FORECAST AREA NORTH COMPARED TO THE 16.00Z CYCLE. MODEL
CONSENSUS NOW SUGGESTS THAT THE SHORTWAVE NEAR FARGO ENDS UP
CROSSING CLARK COUNTY AT 00Z TUESDAY...COMPARED TO SAY LA CROSSE.
THIS HAS A BIG IMPACT ON PLACEMENT OF PRECIPITATION CHANCES.
WITH THE SHORTWAVE TRACKING FARTHER NORTH TODAY...THE COLD FRONT
ONLY DROPS SOUTH TO MAYBE THE I-94 CORRIDOR BY 00Z. COMBINATION OF
LOW LEVEL CONVERGENCE ON THE FRONT...LOW TO MID LEVEL FRONTOGENESIS
NORTH OF THE FRONT...THE APPROACH OF THE SHORTWAVE TO YIELD SOME
DPVA AND DAYTIME HEATING SHOULD PROVE FAVORABLE FOR NUMEROUS SHOWERS
ALONG/NORTH OF I-94. COULD EVEN SEE SOME ISOLATED/SCATTERED ACTIVITY
SOUTH OF THERE TOWARDS I-90 VERY LATE IN THE DAY AS THE FRONTAL
FORCING APPROACHES. DEEP MIXING AGAIN LOOKS LIKELY TODAY AHEAD OF
THE APPROACHING FRONT. NAM/RAP SOUNDINGS SHOW POTENTIAL OF 7500-9500
FT AGL FROM CLARK COUNTY SOUTHWARD...WHICH RESULTS IN HIGHS IN THE
LOW TO PERHAPS EVEN SOME MID 80S. THIS SHOULD ALLOW DEWPOINTS TO
FALL INTO THE LOW TO MID 50S. COMBINATION OF THE TWO RESULTS IN
0-1KM MLCAPES OF 400-700 J/KG IN THE AREA ALONG/NORTH OF THE FRONT.
ALTHOUGH THIS IS NOT MUCH...IT WILL BE ENOUGH TO BOTH ADD
THUNDERSTORMS AND MAKE THE SHOWERS MORE VIGOROUS. FREEZING LEVELS
ARE LOW...9500-1000 FT AGL AT 21Z WHICH COULD ALLOW FOR SOME
HAIL...BUT THE MINIMAL CAPE WHICH IS TALL AND SKINNY MAY KEEP ANY
HAIL SMALL. BIGGER CONCERN WILL LIKELY BE WIND GIVEN THE DEEP MIXING
YIELDING DEEP INVERTED-V LOOKS ON A SKEW-T. COULD SEE STRONG TO
SEVERE WIND GUSTS...JUST LIKE WHAT WENT THROUGH MINNEAPOLIS AROUND
00Z LAST EVENING.
THE VIGOROUS CONVECTIVE ACTIVITY WILL LIKELY DIMINISH QUICKLY AFTER
00Z AS LOSS OF HEATING KNOCKS DOWN CAPE. HOWEVER...
ISOLATED/SCATTERED SHOWER ACTIVITY MAY PERSIST THROUGH MUCH OF THE
NIGHT AS THE FRONT SLOWLY SINKS SOUTH...AIDED BY LOW TO MID LEVEL
FRONTOGENESIS PERSISTING ALONG/NORTH OF THE FRONT. ADDITIONALLY...
AFTER MIDNIGHT TONIGHT...ATTENTION TURNS TO THE SHORTWAVE OVER
SOUTHWEST SASKATCHEWAN. MODELS HAVE SPED UP THIS SHORTWAVE...PERHAPS
MOVING INTO FAR WESTERN PORTIONS OF THE FORECAST AREA BY 12Z TUESDAY
AS SUGGESTED BY THE 17.00Z GFS. 17.00Z NAM/UKMET ARE JUST SLIGHTLY
SLOWER. IN ANY EVENT...DPVA AND A LOWERING TROPOPAUSE WITH THIS
SHORTWAVE WILL LIKELY HELP STRENGTHEN THE LOW TO MID LEVEL
FRONTOGENESIS IN PLACE ALONG/NORTH OF THE FRONT. THUS...THIS
SHORTWAVE SHOULD HELP PROMOTE KEEPING ISOLATED/SCATTERED ACTIVITY
GOING.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 307 AM CDT MON JUN 17 2013
TUESDAY...ATTENTION IS ON THAT SHORTWAVE APPROACHING FAR WESTERN
PORTIONS OF THE FORECAST AREA AT 12Z. AGAIN...WITH MODELS SPEEDING
UP THE SHORTWAVE...THE WAVE PRETTY MUCH EXITS THE AREA BY
18Z...REACHING NORTHWEST INDIANA BY 00Z. MODELS HAVE COME INTO MUCH
BETTER CONSENSUS ON WHETHER THIS SHORTWAVE WILL PRODUCE
PRECIPITATION...WITH THE 17.00Z NAM/GFS/CANADIAN/UKMET/ECMWF AND
HIRES NMM/ARW ALL NOW DEPICTING SOME LIGHT PRECIPITATION. BELIEVE
THE REASON THE QPF IS LIGHT IS THAT THE MOISTURE TRANSPORT IS NOT
ALL THAT GREAT...AND THE AVAILABLE MOISTURE IS SOMEWHAT LIMITED.
HOWEVER...WITH ALL MODELS DEPICTING A FAIRLY STRONG SHORTWAVE PER
500MB PROGS...THE FORCING SHOULD BE ENOUGH TO SQUEEZE OUT SOME
SHOWERS AND POSSIBLY EVEN A THUNDERSTORM OR TWO ONCE DAYTIME HEATING
GETS GOING. THUS...HAVE ADDED 20-30 PERCENT CHANCES TO THE
FORECAST...HIGHEST TUESDAY MORNING. THESE CHANCES MAY NEED TO BE
INCREASED IN LATER FORECASTS. COMBINATION OF CLOUDS ACCOMPANYING THE
SHORTWAVE AND A NORTHEAST LOW LEVEL FLOW OUT OF HIGH PRESSURE IN
UPPER MICHIGAN WILL YIELD A COOLER DAY. HIGHS MOST LOCATIONS SHOULD
END UP IN THE LOW TO MID 70S.
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...THE UPPER LOW OFF THE
PACIFIC NORTHWEST IS PROGGED TO MOVE INLAND DURING THIS
PERIOD...FORCING RIDGING TO INCREASE DOWNSTREAM OVER THE PLAINS.
THIS SETUP WOULD PLACE THE FORECAST AREA IN SUBSIDENCE EAST OF THE
RIDGE AXIS...FAVORABLE FOR HIGH PRESSURE AT THE SURFACE. THIS IS
TRUE ACCORDING TO MODELS...AND WOULD NORMALLY SUGGEST A DRY
FORECAST. HOWEVER...17.00Z NAM AND TO SOME DEGREE THE GFS THROW A
MONKEY WRENCH INTO THIS PLAN...AS THESE MODELS SHOW A NORTH TO SOUTH
ORIENTED SHORTWAVE BARRELING THROUGH THE RIDGE AND MOVING INTO THE
AREA WEDNESDAY NIGHT. BOTH MODELS END UP BRINGING LIGHT
PRECIPITATION INTO THE AREA. MEANWHILE...THE 17.00Z
ECMWF/CANADIAN/UKMET SHOW A MUCH WEAKER REFLECTION OF THIS SHORTWAVE
AS WELL AS SLOWER SPEED. AS A RESULT...THESE MODELS WOULD FAVOR THE
PREVIOUS DRY FORECAST. HAVE STAYED WITH THE DRY FORECAST FOR
NOW...BUT THIS SHORTWAVE WILL NEED SOME WATCHING. OTHERWISE...A COOL
NIGHT LOOKS ON TAP TUESDAY NIGHT WITH THE HIGH PRESSURE AREA IN
PLACE. SOME OF THE TYPICAL COLDER SPOTS COULD DROP INTO THE LOWER
40S. GRADUAL WARMING OF TEMPERATURES EXPECTED FOR HIGHS WEDNESDAY
AND WEDNESDAY NIGHT WITH THE HIGH PRESSURE AREA SLOWLY DRIFTING OFF
TO THE EAST...AS WELL AS AIRMASS MODIFICATION FROM DAYTIME HEATING
TAKING PLACE.
THURSDAY THROUGH THE WEEKEND...
SIMPLY STATED...MORE SUMMER-LIKE WITH INCREASING HUMIDITY...DEALING
WITH CAP CONCERNS AND POTENTIAL FOR MCSS.
17.00Z ECMWF/GFS/CANADIAN AND GFS ENSEMBLES CONTINUE TO SHOW GOOD
RUN-TO-RUN CONSISTENCY ON THE UPPER LEVEL PATTERN. THE TROUGHING
THAT HAS BEEN PERSISTENT IN SOUTHEAST CANADA IS PROGGED TO LIFT OUT
BEGINNING ON THURSDAY. MEANWHILE THE UPPER LOW IN THE PACIFIC
NORTHWEST SLOWLY EJECTS NORTHEAST INTO SOUTH CENTRAL CANADA ON
SUNDAY. THE MOTIONS OF THE TWO TROUGHS ALLOW FOR A FAIRLY
SUBSTANTIAL WARM/MOIST AIR ADVECTION TO TAKE PLACE ACROSS THE PLAINS
AND TOWARDS THE FORECAST AREA. AS A RESULT...THE POTENTIAL EXISTS
FOR MULTIPLE ROUNDS OF CONVECTION AS VARIOUS MCSS FORM. RUN-TO-RUN
MODEL CONSISTENCY AS WELL AS AGREEMENT ON THE MCS TRACKS IS FAIRLY
LOW...AND TO BE EXPECTED. THE ONLY WELL AGREED UPON MCS APPEARS TO
BE ON FRIDAY INTO SATURDAY WHERE AN MCS FORMS OVER THE DAKOTAS AND
TRACKS EAST INTO NORTHERN WI SAT MORNING. THUS...FOLLOWING A MODEL
CONSENSUS FOR PRECIPITATION CHANCES YIELDS 40-60 PERCENT CHANCES
ACROSS THE FORECAST AREA FOR SATURDAY...HIGHEST TOWARDS NORTHERN WI.
THERE ARE INDICATIONS TOO THAT CAPPING WILL BE AN ISSUE TO
CONTEND WITH AS 700MB TEMPS OVER 12C BEGIN ADVECTING TOWARDS THE
AREA FOR THE WEEKEND.
WE WILL DEFINITELY NEED TO WATCH FOR SEVERE WEATHER AND HEAVY RAIN
HEADING INTO THE WEEKEND...GIVEN THE MCS POTENTIAL AND WARM CLOUD
DEPTHS PROGGED IN THE 3500-4500 FT RANGE.
TEMPERATURES ARE EXTREMELY TRICKY AS THEY DEPEND ON HOW CONVECTION
EVOLVES...ESPECIALLY DAYTIME HIGHS. MODELS HAVE TRENDED WARMER FOR
THURSDAY THROUGH THE WEEKEND...SO HAVE FOLLOWED SUIT AND RAISED
HIGHS. HOWEVER...THESE MAY NEED FURTHER INCREASES IF SAY THE CURRENT
17.00Z ECMWF/GFS ARE CORRECT. THIS IS ESPECIALLY TRUE WHERE ON
SATURDAY THEY BOOST 850MB TEMPS UP TO 20-24C...OR 2 STANDARD
DEVIATIONS ABOVE NORMAL. HIGHS COULD EASILY CLIMB INTO THE LOW TO
POSSIBLY EVEN MID 90S IF THIS COMES TRUE. EVAPOTRANSPORATION AND
MOISTURE ADVECTION SHOULD HELP BOOST DEWPOINTS INTO THE 70S...WHICH
THIS LATENT HEATING WILL KEEP HIGHS FROM GETTING MUCH HIGHER THAN
THAT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1255 PM CDT MON JUN 17 2013
A WEAK COLD FRONT AND UPPER LEVEL DISTURBANCE DROPPING SOUTH
ACROSS THE REGION THIS AFTERNOON THROUGH TONIGHT WILL BRING A
SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS TO THE TAF SITES.
CONFIDENCE IS LOW ON THIS ACTIVITY IMPACTING THE TAF SITES...GIVEN
THE ISOLATED NATURE...SO WILL HAVE TO MONITOR THE SHRA/TSRA
ACTIVITY OVER NORTH CENTRAL/NORTHWEST WISCONSIN THIS AFTERNOON AS
IT EDGES SOUTH TOWARD THE INTERSTATE 90 CORRIDOR. IF STORMS MAKE
IT TO THE TAF SITES LATE THIS AFTERNOON INTO EARLY THIS
EVENING...THEY WOULD BE CAPABLE OF PRODUCING GUSTING WIND OF 30 TO
40 KTS AND POSSIBLY SMALL HAIL. OTHERWISE...PLAN ON VFR CONDITIONS
WITH SCATTERED TO BROKEN CUMULUS WITH CLOUD BASES IN THE 4500 TO
6000 FT RANGE. ISOLATED SHOWERS AND STORMS ARE POSSIBLE DURING THE
OVERNIGHT HOURS...WITH THE BETTER CHANCES FOR THESE SOUTH AND WEST
OF KLSE LATE...POSSIBLY IMPACTING KRST AFTER MIDNIGHT AS THE FRONT
SAGS SOUTH.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM....AJ
AVIATION...WETENKAMP
AREA FORECAST DISCUSSION
NWS RIVERTON WY
240 PM MDT MON JUN 17 2013
.SHORT TERM...TONIGHT THROUGH TUESDAY
SHOWERS AND THUNDERSTORMS HAVE BEGUN TO DEVELOP ACROSS THE
MOUNTAINOUS AREAS OF THE FORECAST AREA THIS AFTERNOON. SOME STORMS
HAVE BEGUN TO MOVE INTO THEIR ADJACENT VALLEYS AND BASINS...MAINLY
ACROSS THE UPPER GREEN RIVER BASIN AND JOHNSON COUNTY. ADDITIONAL
STORM ACTIVITY IS ANTICIPATED THROUGH THE AFTERNOON...AND SHOULD
LINGER INTO THE EARLY EVENING HOURS. ACTIVITY WILL WANE WITH THE
LOSS OF DAYLIGHT THIS EVENING...BUT ACTIVITY WILL LINGER OVER THE
CENTRAL AND NORTHERN MOUNTAINS.
ANOTHER...STRONGER DISTURBANCE WILL MOVE OVER THE FORECAST AREA
TUESDAY AFTERNOON. STORMS ARE ANTICIPATED TO START DURING THE EARLY
AFTERNOON HOURS. SOME STORMS WILL SEE THE POTENTIAL TO BECOME
STRONG...ESPECIALLY DURING THE LATER AFTERNOON HOURS. STRONGER
THUNDERSTORMS MAY SEE THE POTENTIAL FOR VERY STRONG WIND GUSTS AND
LARGER HAIL. THESE STRONGER STORMS SEEM MOST FAVORABLE ACROSS
JOHNSON COUNTY...BUT THE EXTENT OF STRONGER STORM COVERAGE MAY NOT
BE REALIZED UNTIL LATE MORNING TUESDAY.
TEMPERATURES WILL WARM ACROSS THE AREA TUESDAY...WITH RELATIVE
HUMIDITY AGAIN DECREASING TO THE SINGLE DIGITS ACROSS SOUTHERN
WYOMING. WIND WILL INCREASE SOMEWHAT DURING THE AFTERNOON...BUT ARE
NOT EXPECTED TO BE SIGNIFICANT ACROSS THE BULK OF THE AREA. THE
EXCEPTION MIGHT BE SOUTHEASTERN SWEETWATER COUNTY.
.LONG TERM...TUESDAY NIGHT THROUGH MONDAY NIGHT
THE THUNDERSTORMS OF TUESDAY AFTERNOON LOOK TO CONTINUE INTO TUESDAY
EVENING BEFORE SLOWLY WANING WITH THE LOSS OF DAYTIME HEATING AND
DRIER AIR PUNCHING IN FROM THE WEST AND SOUTH. MADE FEW CHANGES TO
THE PLACEMENT OF THE STORMS WITH ACTIVITY MAINLY NORTH OF THE WIND
RIVER RANGE...CLOSELY FOLLOWING THE 0.50 PRECIPITABLE WATER LINE.
ON WEDNESDAY ACTIVITY LOOKS TO BE LESS THAN ON TUESDAY WITH MODELS
SHOWING MUCH DRIER AIR IN PLACE ACROSS THE COUNTY WARNING AREA WITH
PRECIPITABLE WATER VALUES FALLING TO UNDER 0.50 FOR ALL AREAS. ANY
CONVECTION WOULD LIKELY BE LIMITED TO NORTHWESTERN WYOMING WHERE
THERE WILL BE A BIT MORE MOISTURE TO WORK WITH AND SOMEWHAT MORE
INSTABILITY DUE TO A CLOSER PROXIMITY TO AN UPPER LEVEL LOW OVER
IDAHO. WITH A COLD FRONT APPROACHING AND MOVING THROUGH...THE
PRESSURE GRADIENT WILL TIGHTEN UP A BIT AND BRING SOME GUSTY WINDS
ACROSS AREAS EAST OF THE DIVIDE...ESPECIALLY ACROSS THE SOUTHWESTERN
WIND CORRIDOR FROM THE RED DESERT THROUGH ROCK SPRINGS. IT DOES NOT
LOOK LIKE HIGH WIND SINCE 700 MILLIBAR WINDS ARE NOT STRONG
ENOUGH...BUT SOME WIND GUSTS TO 40 TO 50 MPH ARE CERTAINLY POSSIBLE.
THERE COULD BE SOME ELEVATED FIRE DANGER IN THE AFTERNOON WITH
RELATIVE HUMIDITY FALLING BELOW 10 PERCENT BUT NO RED FLAGS AT THIS
TIME SINCE FUELS ARE NOT CRITICAL YET. THE DOWNSLOPING WIND WILL
BRING A WARM DAY WITH SOME BASINS SEEING HIGHS AROUND 90. LITTLE
CONVECTION IS EXPECTED EAST OF THE DIVIDE EXCEPT IN THE HIGHER
ELEVATIONS. COOLER AIR WILL ADVECT IN BEHIND THE FRONT FOR WEDNESDAY
NIGHT. IT COULD GET QUITE CHILLY IN THE WESTERN VALLEYS...WITH EVEN
SOME PATCHY FROST IN THE MORE PROTECTED SPOTS.
THURSDAY LOOKS TO BE A COOLER DAY BEHIND THE FRONT WITH LESS WIND AS
WELL. AS FOR ANY CHANCE OF CONVECTION...WE CAN NOT RULE SOMETHING
OUT IN THE FAR NORTHWEST BUT MOISTURE WILL BE LACKING SO FOR WE
TRIMMED POPS A BIT ACROSS NORTHERN WYOMING AND KEPT ANY ACTIVITY
DOWN TO SLIGHT CHANCE. AS A SIDE NOTE...THE SUMMER SOLSTICE IS AT
11:04 PM ON THURSDAY NIGHT SO THAT IS WHEN SUMMER ARRIVES.
AND NOW...TO CELEBRATE THE FIRST FULL DAY OF SUMMER...WE PRESENT THE
DISCUSSION OF FRIDAY WITH THE METEOROLOGICAL VERSION OF THE CLASSIC
OLD SCHOOL RAP SONG SUMMERTIME. SO...DRUMS PLEASE.
HERE IT IS...A PATTERN SLIGHTLY TRANSFORMED
A BIT OF A BREAK FROM THE LATE SPRING NORM
JUST A LITTLE WEATHER TO BREAK THE MONOTONY
OF ALL THE STRONG STORMS THAT HAVE GOTTEN TO BE
A LITTLE BIT OUT OF CONTROL AS THE DAY STARTS OFF COOL
BUT ENDS UP WARM ENOUGH TO GO SWIMMING AT THE POOL
GIVE ME A NICE GENTLE BREEZE
JUST ENOUGH TO RUFFLE THE LEAVES ON THE TREES
AND JUST LIKE THE DAY THAT HAS JUST PAST
IN JOHNSON COUNTY ISOLATED THUNDERSTORMS MAY BLAST
BUT ALL IN ALL AS AFTERNOON TEMPERATURES CLIMB
IT LOOKS NICE FOR THE FIRST DAY OF SUMMERTIME.
IN OTHER WORDS...THE UPPER LEVEL LOW WILL LIFT INTO MONTANA AND LOSE
SOME ITS INFLUENCE OVER THE WEATHER. A BIT MORE MOISTURE MAY HANG
AROUND FAR NORTHERN AND NORTHEASTERN WYOMING BUT ANY CONVECTION
SHOULD BE ISOLATED AT BEST WITH A VAST MAJORITY OF THE AREA RAIN
FREE. SATURDAY LOOKS LIKE A FAIRLY SIMILAR TODAY WITH ISOLATED
CONVECTION ACROSS THE FAR NORTH AND EAST WITH SLIGHTLY DEEPER
MOISTURE BRUSHING BY. TEMPERATURES WILL BE SOMEWHAT ABOVE NORMAL BUT
NOT UNUSUALLY SO. AS FOR SUNDAY AND MONDAY...CONTINUITY INDICATED
MAINLY ISOLATED ACTIVITY ACROSS MORE OF THE AREA WITH SOMEWHAT MORE
MOISTURE SPREADING IN. THE EUROPEAN LOOKS MAINLY DRY WITH THE RIDGE
AXIS OVER THE AREA BUT GIVEN UNCERTAINTY ONLY MINOR CHANGES WERE
MADE.
&&
.AVIATION.../00Z ISSUANCE/
SHOWERS AND THUNDERSTORMS WILL IMPACT EASTERN WYOMING THROUGH 04Z
THIS EVENING...WEAKENING WITH LOSS OF DAYLIGHT. FOR MOST OF THE
FORECAST AREA...THESE STORMS SHOULD REMAIN OVER THE MOUNTAINS.
HOWEVER...KCPR WILL SEE THE POTENTIAL FOR SOME SHOWER
ACTIVITY...WHICH MAY BRING BRIEF PERIODS OF MVFR CONDITIONS.
CONDITIONS WILL IMPROVE THROUGH THE EVENING AND OVERNIGHT HOURS WITH
WIDESPREAD VFR CONDITIONS EXPECTED AT THE TERMINALS. ANOTHER ROUND
OF SHOWERS AND THUNDERSTORMS WILL IMPACT WESTERN AND CENTRAL WYOMING
AFTER 18Z TUESDAY. STORMS MAY IMPACT MORE TERMINALS ACROSS THE
AREA...ESPECIALLY AFTER 20Z. MVFR CONDITIONS WITH GUSTY WIND AND
SMALL HAIL MAY BE PRESENT THROUGH THE AFTERNOON. A STRONGER STORM
WILL BE POSSIBLE AROUND KCPR...POTENTIALLY BRINGING VERY STRONG WIND
TO THE TERMINAL.
&&
.FIRE WEATHER...
SHOWERS AND THUNDERSTORMS ARE EXPECTED ACROSS PORTIONS OF EASTERN
AND NORTHERN WYOMING THROUGH THE EVENING HOURS TONIGHT. ACTIVITY
WILL WEAKEN WITH LOSS OF DAYLIGHT...THOUGH SOME MAY LINGER OVER THE
CENTRAL MOUNTAINS. ANOTHER WARM AND DRY DAY IS EXPECTED ACROSS
SOUTHERN WYOMING ON TUESDAY...WITH HUMIDITY DECREASING INTO THE
SINGLE DIGITS. A SLIGHT INCREASE IN WIND IS ANTICIPATED DURING THE
AFTERNOON...BUT SHOULD NOT BE SIGNIFICANT. HOWEVER...STRONGER
THUNDERSTORMS MAY RETURN TO NORTHEASTERN WYOMING DURING THE
AFTERNOON. THE STRONGEST STORMS MAY HAVE THE POTENTIAL FOR STRONG
ERRATIC WIND AND LARGER HAIL. THE PROMINENT AREAS FOR THIS
DEVELOPMENT ARE JOHNSON AND NATRONA COUNTIES...WITH SOME POTENTIAL
OVER THE BIGHORN BASIN.
&&
.RIW WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BRANHAM
LONG TERM...HATTINGS
AVIATION...BRANHAM
FIRE WEATHER...BRANHAM