Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 06/15/13
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
245 PM CDT THU JUN 13 2013
.SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT
W-E ORIENTED CDFNT WAS SITUATED ACRS CNTRL AR AT MID AFTN. DEWPOINTS
IN THE LOWER AND MID 70S HAVE POOLED IN THE VCNTY OF THE BNDRY...
RESULTING IN HEAT INDICES BETWEEN 100 AND 105 DEGREES. HAVE SEEN A
FEW WEAK RADAR RETURNS OVR ERN AR. THE RUC AND HRRR MODELS CONT TO
INDCD ISOLD SHRA/TSRA DVLPG ALONG THE FNT OVR CNTRL/SERN AR LATE
THIS AFTN/EARLY EVENING. THUS...WL LEAVE SOME SMALL POPS IN PER
GOING FCST.
THE AFOREMENTIONED CDFNT WL EVENTUALLY STALL OUT TO THE SW OF THE
AREA BY FRI AS A WEAK SFC RDG BLDS INTO AR. THE BNDRY WL MEANDER IN
THE VCNTY OF WRN AR HEADING INTO THE WEEKEND. CANNOT RULE OF A STRAY
SHRA/TSRA FRI AND SAT ALONG WITH WRN PERIPHERY OF THE SFC RDG...BUT
WL KEEP A DRY FCST IN PLACE. E/NELY SFC WINDS BEHIND THE FNT WL
BRING DRIER AND SLIGHTLY COOLER AIRMASS TO MUCH OF THE FA.
THE SFC HIGH WL WEAKEN ENOUGH BY SUN/SUN NGT FOR A RETURN OF SLY
WINDS...ALONG WITH INCRSG LOW LVL RH. MEANWHILE...THE UPR LVL FLOW
WL FLATTEN TO ALLOW A NEW CDFNT WL APCH AR FM THE N...ALONG WITH A
BETTER CHC OF SHRA/TSRA. THE UNSETTLED PATTERN WL CONT INTO THE LONG
TERM PD.
&&
.LONG TERM...MONDAY THROUGH THURSDAY
UPPER RIDGE WILL BE PUSHED SOUTH OF THE STATE FOR THE BEGINNING OF
NEXT WEEK...AND ALLOW A COLD FRONT TO MOVE INTO THE STATE. MODELS
ARE IN BETTER AGREEMENT OF MOVING THIS FRONT FURTHER INTO THE STATE
THAN PREVIOUS RUNS...AND HAVE INCREASED POPS TO THE CHANCE CATEGORY
FOR MONDAY INTO TUESDAY. UPPER RIDGE WILL BEGIN TO BUILD BACK OVER
THE AREA WEDNESDAY INTO THURSDAY...WITH RAIN CHANCES DWINDLING.
TEMPERATURES WILL CONTINUE TO BE ABOVE NORMAL ACROSS THE SOUTH...
WHILE NORTHERN ARKANSAS WILL HAVE A LITTLE COOLER TEMPERATURES DUE
TO CLOUD COVER AND RAINFALL.
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...44 / LONG TERM...58
AREA FORECAST DISCUSSION
NWS FLAGSTAFF AZ
859 PM MST FRI JUN 14 2013
.SYNOPSIS...
THERE IS A SLIGHT CHANCE OF THUNDERSTORMS ON SATURDAY OVER
NORTHERN ARIZONA...BUT LITTLE RAINFALL IS EXPECTED. BREEZY
CONDITIONS WILL PERSIST WITH TEMPERATURES AROUND NORMAL. BY SUNDAY
AND INTO NEXT WEEK...INCREASING SOUTHWEST WINDS AND MUCH DRIER AIR
WILL END THE CHANCE OF THUNDERSTORMS...WITH SEASONABLY WARM
TEMPERATURES.
&&
.DISCUSSION...
GENERALLY CLEAR SKIES ARE IN PLACE ACROSS NORTHERN AZ THIS
EVENING. NO SIGNIFICANT UPDATES PLANNED BEFORE THE MORNING
FORECAST PACKAGE.
&&
.PREVIOUS DISCUSSION /245 PM MST/...
ONLY A FEW ISOLATED SHOWERS OVER THE EASTERN RIM AND WHITE MTS SO
FAR THIS AFTERNOON...LESS THAN YESTERDAY...AND IN AGREEMENT WITH
THE HRRR MODEL RUNS. EXPECT ANY SHOWERS TO DIMINISH EARLY THIS
EVENING BRINGING MOSTLY CLEAR SKIES FOR THE REST OF THE NIGHT.
MINOR DIGGING OF THE TROUGH OFF THE WEST COAST WILL ALLOW FOR A
MORE SOUTHERLY FETCH ACROSS ARIZONA ON SATURDAY...BRINGING A
TEMPORARY INCREASE IN MOISTURE...AND RESULTING IN ISOLATED TO
SCATTERED WEAK THUNDERSTORM ACTIVITY. MODEL RUNS INDICATE THE
GREATEST CHANCES FOR THUNDERSTORMS WILL BE ALONG AND NORTH OF THE
MOGOLLON RIM SATURDAY AFTERNOON..WHERE THE MOISTURE AXIS COINCIDES
WITH THE TIME OF MAXIMUM HEATING...AND NORTHEASTERLY STORM MOTION.
LITTLE PRECIPITATION IS EXPECTED FROM THE STORMS AS THE LOWER
ATMOSPHERE WILL REMAIN QUITE DRY.
MUCH DRIER AIR ADVECTS INTO THE AREA LATE SUNDAY THROUGH EARLY
NEXT WEEK AS THE FLOW TURNS MORE WESTERLY. NO PRECIPITATION IS
EXPECTED THROUGH NEXT WEEK AS A STRENGTHENING TROUGH DEVELOPS OVER
THE PACIFIC NORTHWEST...KEEPING A VERY DRY SOUTHWESTERLY FLOW IN
PLACE OVER ARIZONA. BREEZY...TO OCCASIONALLY WINDY CONDITIONS CAN
BE EXPECTED BY MIDWEEK...POSSIBLY APPROACHING CRITICAL FIRE
WEATHER THRESHOLDS.
&&
.AVIATION...
FOR THE 06Z PACKAGE...-SHRA/-TSRA POSSIBLE AFTER 18Z
SATURDAY...MOSTLY EAST OF A KPRC- KGCN LINE...WITH GUSTY WINDS
AND LITTLE RAIN. OTHERWISE...VFR CONDITIONS EXPECTED TO PERSIST.
SOUTHWESTERLY BREEZES ALSO DURING THE DAYTIME HOURS. AVIATION
DISCUSSION NOT UPDATED FOR AMENDMENTS.
&&
.FIRE WEATHER...
A MODEST INCREASE IN MOISTURE WILL CONTINUE TO IMPACT NORTHERN
ARIZONA THROUGH SATURDAY. VERY DRY CONDITIONS AND LOW RH VALUES
WILL PERSIST ACROSS FAR WESTERN ZONES...PRIMARILY WEST OF A KPRC-
KFLG LINE WITH DEWPOINTS AND RH INCREASING WITH EASTWARD EXTENT.
PRIMARILY DRY THUNDERSTORM ACTIVITY WHICH HAS BEEN LIMITED TO THE
WHITE MOUNTAIN REGION THE PAST COUPLE DAYS WILL EXPAND SATURDAY TO
ENCOMPASS THE EASTERN TWO THIRDS OF NORTHERN AZ. THESE
THUNDERSTORMS MAY PRODUCE GUSTY WINDS...BUT LITTLE RAIN. THE
WHITE MOUNTAIN AREA MAY FARE BETTER WITH WETTING RAINFALL
ACCOMPANYING THE HEAVIEST DOWNPOURS. DRY AIR ATTEMPTS TO RETURN
SUNDAY WITH TSTORM ACTIVITY BECOMING LIMITED TO THE WHITE
MOUNTAINS AND LOWER RH VALUES PUSHING IN FROM THE WEST.
MONDAY THROUGH WEDNESDAY...
EXPECT BREEZY SOUTHWEST WINDS EACH AFTERNOON WITH SPEEDS BELOW
CRITICAL VALUES. AFTERNOON RELATIVE HUMIDITIES SHOULD BE FROM 10 TO
15 PERCENT ALONG THE MOGOLLON RIM AND SINGLE DIGITS ELSEWHERE.
WEDNESDAY MAY SEE AN INCREASE IN AFTERNOON BREEZINESS AND ENHANCED
FIRE WEATHER POTENTIAL BUT STILL EXPECTED TO REMAIN BELOW CRITICAL
THRESHOLDS FOR NOW. DESPITE THE FORECAST REMAINING BELOW CRITICAL
RED FLAG CONDITIONS...IT MAY APPROACH IT AND FIRE DANGER WILL
REMAIN VERY HIGH WITH HIGH HAINES VALUES EACH AFTERNOON.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC.........KD/BAK
AVIATION.......KD
FIRE WEATHER...OUTLER
FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF
AREA FORECAST DISCUSSION
NWS TUCSON AZ
235 PM MST THU JUN 13 2013
.SYNOPSIS...THERE IS A SLIGHT CHANCE OF AFTERNOON AND EVENING
THUNDERSTORMS EAST OF TUCSON THROUGH SATURDAY. OTHERWISE...EXPECT
HOT AND DRY CONDITIONS TO CONTINUE INTO THE MIDDLE OF NEXT WEEK.
&&
.DISCUSSION...KEMX WSR-88D DETECTED ISOLATED 40-45 DBZ ECHOES ACROSS
THE WHITE MOUNTAINS VICINITY OF HANNAGAN MEADOW AT 2130Z. THE REST
OF SE AZ WAS VOID OF PRECIP ECHOES AT THIS TIME. OTHER STRONGER
PRECIP ECHOES WERE JUST EAST OF THIS FORECAST AREA IN SW NEW MEXICO.
THE 13/18Z RUC HRRR APPEARED TO HAVE AN EXCELLENT START OF THE CYCLE
REGARDING THE ONGOING PRECIP. SHOWERS/TSTMS PRODUCING VERY LITTLE
RAINFALL SHOULD DEVELOP DURING THE NEXT FEW HOURS ACROSS THE
CHIRICAHUA MOUNTAINS OF FAR ERN COCHISE COUNTY. THEREAFTER...OUTFLOW
FROM ONGOING CONVECTION IN SW NEW MEXICO MAY GENERATE ADDITIONAL
SHOWERS/TSTMS ACROSS THE NEW MEXICO BOOTHEEL AND MOVE INTO SE
COCHISE COUNTY THIS EVENING.
THUS...HAVE MAINTAINED A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS
FOR EASTERN COCHISE COUNTY AS WELL AS THE WHITE MOUNTAINS THIS
EVENING. DRY CONDITIONS ELSEWHERE THIS EVENING. ANY PRECIP IS
EXPECTED TO END BY ABOUT MIDNIGHT. ANY MEASURABLE PRECIP SHOULD ONLY
BE A FEW HUNDREDTHS OF AN INCH.
EXPECT SHOWER/TSTM COVERAGE TO BE SLIGHTLY HIGHER FRI VERSUS THIS
AFTERNOON AND THIS EVENING AS MOISTURE CONTINUES TO INCREASE ACROSS
THE AREA. THUS...THE OFFICIAL FORECAST DEPICTS A SLIGHT CHANCE OF
SHOWERS/TSTMS GENERALLY EAST OF A HANNAGAN MEADOW-SIERRA VISTA LINE
FRI AFTERNOON AND FRI EVENING WITH DRY CONDITIONS ELSEWHERE.
CONFIDENCE IS FAIRLY LOW REGARDING THE POTENTIAL FOR PRECIP SAT.
THE 13/12Z GFS WAS MARKEDLY MORE MOIST VERSUS THE 13/12Z ECMWF.
HOWEVER...HAVE NOTED AN UPWARD TREND IN PROGGED MOISTURE EXHIBITED
VIA THE ECMWF VERSUS PREVIOUS SOLUTIONS. AT ANY RATE...HAVE BROUGHT
A SLIGHT CHANCE OF SHOWERS/TSTMS SAT AFTERNOON AND SAT EVENING AS
FAR WEST AS THE CATALINA/RINCON MOUNTAINS JUST EAST OF TUCSON. FOR
NOW HAVE MAINTAINED DRY CONDITIONS FROM TUCSON WWD.
BY SUN...GFS/ECMWF WERE IN FAIRLY DECENT AGREEMENT WITH ADVECTING
DEEPER MOISTURE WELL EAST OF THIS FORECAST AREA. THUS...ONLY SINGLE
DIGIT POPS SUN ACROSS GREENLEE/GRAHAM/COCHISE COUNTIES WITH ZERO
POPS FROM TUCSON WWD. CLEAR SKIES OR MOSTLY CLEAR SKIES TO THEN
OCCUR MON-THUR AS WLY/SWLY FLOW ALOFT PREVAILS. HAVE NOTED THAT THE
ECMWF WAS DEEPER WITH THE WRN CONUS TROUGH VERSUS THE GFS. IF
REALITY...THE TIGHTER MID-LEVEL GRADIENT MAY LEAD TO BREEZY
AFTERNOONS WED-THUR.
HIGH TEMPS FRI WILL GENERALLY BE ABOUT 2-3 DEGS F LOWER VERSUS TEMPS
ACHIEVED THIS AFTERNOON. EXPECT NO SIGNIFICANT CHANGE IN DAYTIME
TEMPS SAT-THUR...WITH HIGH TEMPS TO REMAIN SEVERAL DEGS ABOVE NORMAL.
&&
.AVIATION...THERE IS A SLIGHT CHANCE OF -TSRA/-SHRA EAST OF A
KSAD-KFHU LINE THRU 14/03Z. WIND GUSTS TO AROUND 45 KTS MAY OCCUR
WITH THIS ACTIVITY. OTHERWISE...FEW-SCT CLOUDS ABOVE 12K FT AGL WILL
PREVAIL THRU FRIDAY MORNING OR 14/18Z. SURFACE WIND WLY/NWLY AT
12-18 KTS WITH GUSTS TO NEAR 25 KTS THRU 14/03Z...THEN SURFACE WIND
LESS THAN 10 KTS TIL 14/16Z. SLIGHT CHANCE OF -TSRA/-SHRA AGAIN
FRIDAY AFTERNOON/EVENING EAST OF A KSAD-KFHU LINE. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...THERE IS A SLIGHT CHANCE OF DRY THUNDERSTORMS OVER
THE THREE EASTERN COUNTIES OF SOUTHEAST ARIZONA (GREENLEE...GRAHAM
AND COCHISE) THROUGH THE EVENING HOURS TONIGHT...CONTINUING FRIDAY
AND SATURDAY AFTERNOON AND EVENING. ANY THUNDERSTORMS THAT DEVELOP
WILL BE CAPABLE OF PRODUCING STRONG...GUSTY AND ERRATIC WINDS...BUT
LITTLE IF ANY RAINFALL.
OTHERWISE...DRY AND HOT CONDITIONS WILL CONTINUE THROUGH NEXT WEEK.
DAYTIME MINIMUM RELATIVE HUMIDITIES WILL GENERALLY BE IN THE SINGLE
DIGITS TO LOWER TEENS WITH POOR OVERNIGHT RECOVERIES. OUTSIDE OF ANY
THUNDERSTORMS EXPECT NORMAL DIURNAL WIND TRENDS...WITH OCCASIONAL
GUSTS DURING THE AFTERNOON AND EARLY EVENING HOURS DUE TO THE STRONG
SOLAR HEATING.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
DISCUSSION...BF
AVIATION/FIRE WEATHER...GZ
AREA FORECAST DISCUSSION
NWS TUCSON AZ
950 AM MST THU JUN 13 2013
.SYNOPSIS...THERE IS A SLIGHT CHANCE OF AFTERNOON AND EVENING
THUNDERSTORMS MAINLY NEAR THE NEW MEXICO BORDER THURSDAY AND FRIDAY.
OTHERWISE...EXPECT HOT AND DRY CONDITIONS TO CONTINUE INTO THE
MIDDLE OF NEXT WEEK.
&&
.DISCUSSION...LOW LEVEL MOISTURE INCREASE FROM THE GULF OF
CALIFORNIA OCCURRED LAST NIGHT. DEWPOINTS ACROSS SE AZ VALID 13/16Z
RANGED FROM THE MID 30S-UPPER 40S F...AND THESE TEMPS WERE NEARLY
10-20 DEGS F HIGHER VERSUS 24 HOURS AGO. 13/12Z KTWC SOUNDING ALSO
DEPICTED AN INCREASE IN MOISTURE VERSUS 24 HOURS AGO...WITH TOTAL
PRECIP WATER NEAR 0.80 INCH. SLIGHTLY UNSTABLE REGIME WITH LIFTED
INDEX OF MINUS 1.
WILL INCREASE POPS FOR THIS AFTERNOON AND THIS EVENING TO DEPICT A
SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS FOR EASTERN COCHISE
COUNTY BASED ON THE 13/12Z NAM/GFS AND 13/13Z RUC HRRR. HAVE NOTED
THAT THE RUC PRODUCED PRECIP ECHOES AS FAR WEST AS THE HUACHUCA MTNS
THIS AFTERNOON. THUS...WILL NEED TO MONITOR FOR THE POTENTIAL
DEVELOPMENT OF MAINLY DRY THUNDERSTORMS FURTHER WWD THIS AFTERNOON
THAN THE OFFICIAL FORECAST INDICATES.
OTHERWISE...WEAK UPPER LOW/INVERTED TROUGH JUST SOUTH OF THE TEXAS
BIG BEND WILL REMAIN QUASI-STATIONARY TODAY. UPPER LOW WILL THEN
MOVE NWD INTO WEST TEXAS BY SAT. THIS SYSTEM WILL BRING INCREASED
MOISTURE TO THE EASTERN SECTIONS OF THIS FORECAST AREA THRU AT LEAST
FRI. THE BEST CHANCE FOR PRECIP WILL BE ACROSS THE WHITE MOUNTAINS
AS WELL AS THE CHIRICAHUA MOUNTAINS IN ERN COCHISE COUNTY.
QUICK GLANCE AT THE 13/12Z GFS SUGGESTS THE NEED FOR INCREASED POPS
ACROSS ERN COCHISE COUNTY FOR SAT. WILL ADDRESS THIS NOTION FURTHER
IN THE AFTERNOON DISCUSSION. THEREAFTER...A SWLY FLOW ALOFT REGIME
IS FORECAST TO OCCUR SUN-WED. THUS...FOR NOW WILL MAINTAIN PRECIP-
FREE CONDITIONS FOR THE EARLY AND MIDDLE PORTION OF NEXT WEEK.
THERE WILL BE A VERY SLIGHT MODERATION IN DAYTIME TEMPS TODAY THRU
FRI. HOWEVER...HIGH TEMPS WILL STILL REMAIN ABOUT 3-5 DEGS F ABOVE
NORMAL. EXPECT NO SIGNIFICANT CHANGE IN DAYTIME TEMPS THIS WEEKEND
FOLLOWED BY SLIGHTLY HOTTER TEMPS EARLY NEXT WEEK.
&&
.AVIATION...THERE IS A SLIGHT CHANCE OF -TSRA/-SHRA EAST OF A KSAD-
KFHU LINE THIS AFTERNOON AND THIS EVENING. WIND GUSTS TO AROUND 40
KTS MAY OCCUR WITH THIS ACTIVITY. OTHERWISE...FEW-SCT CLOUDS ABOVE
12K FT AGL WILL PREVAIL THRU FRIDAY MORNING OR 14/18Z. SURFACE WIND
INTO EARLY THIS EVENING WLY/NWLY 12-18 KTS WITH GUSTS TO NEAR 25
KTS. OTHERWISE...SURFACE WIND LESS THAN 10 KTS. AVIATION DISCUSSION
NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...THERE IS A SLIGHT CHANCE OF AFTERNOON AND EVENING
THUNDERSTORMS MAINLY NEAR THE NEW MEXICO BORDER TODAY AND FRIDAY
DURING THE AFTERNOON AND EVENING HOURS. GIVEN THE DRY SURFACE
ENVIRONMENT...ANY THUNDERSTORMS THAT DEVELOP WILL BE CAPABLE OF
PRODUCING STRONG...GUSTY AND ERRATIC WINDS. OTHERWISE...DRY AND HOT
CONDITIONS WILL CONTINUE INTO THE MIDDLE OF NEXT WEEK. DAYTIME
MINIMUM RELATIVE HUMIDITIES WILL GENERALLY BE IN THE SINGLE DIGITS
TO LOWER TEENS WITH POOR OVERNIGHT RECOVERIES. EXPECT NORMAL DIURNAL
WIND TRENDS...WITH GUSTINESS DURING THE AFTERNOON HOURS DUE TO STRONG
DAYTIME HEATING.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
BF
AREA FORECAST DISCUSSION
NWS NEW YORK NY
209 PM EDT THU JUN 13 2013
.SYNOPSIS...
LOW PRESSURE APPROACHES THE REGION THIS AFTERNOON AND THEN PASSES
SOUTH AND EAST OF LONG ISLAND TONIGHT AND FRIDAY. HIGH PRESSURE
BUILDS INTO REGION FOR THE WEEKEND. ANOTHER AREA OF LOW PRESSURE
WILL TRACK ACROSS SOUTHERN CANADA EARLY NEXT WEEK WITH A ITS
FRONTAL SYSTEM IMPACTING THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
LOW PRES NOW ENTERING WESTERN NY/PA...AND IS BEGINNING TO TRACK TO
THE SOUTHEAST. LOWEST PRES FALLS OVER THE LAST 3 HR IS OVER SE
PA...SO THE LOW IS ON TRACK TO APPROACH THE DELMARVA LATER THIS
AFTERNOON.
AS THE FIRST WAVE OF SHOWERS AND THUNDERSTORMS EXITS THE EASTERN
HALF OF THE CWA...AN AREA OF DRY WEATHER WILL MOVE INTO THE
REGION. AS A RESULT...WILL TAPER DOWN POP/QPF FORECAST. WILL CARRY
CHANCE POPS FOR THE REST OF THE AFTERNOON...BUT IF THERE IS ENOUGH
CLEARING AHEAD OF THE LOW...SFC TEMPS WOULD THEN WARM UP...
ALLOWING CAPE VALUES TO RISE. THINK PRECIP WILL FILL IN DURING THE
AFTERNOON...BUT NOT QUITE AS WIDESPREAD AS PREVIOUSLY EXPECTED.
ANOTHER LINE OF SHOWERS AND THUNDERSTORMS ASSOCIATED WITH THE H5
TROUGH/VORT MAX IS TRACKING SOUTHEAST THROUGH WV/KY.
AS THE LOW APPROACHES THIS EVENING...AND PIVOTS AROUND THE BASE OF
AN H5 TROUGH DIGGING INTO THE EAST COAST...WILL SEE SHOWERS
DEVELOPING ONCE AGAIN THIS EVENING. LATEST HRRR GUIDANCE HAS SHOWERS
AND THUNDERSTORMS REDEVELOPING OVER THE AREA AFTER MIDNIGHT
TONIGHT AS THE SFC LOW/H5 VORT MAX PIVOTS AROUND THE BASE OF THE
TROUGH AS IT DIGS INTO THE EAST COAST. LATEST NAM KEEPS THE BULK
OF THE PRECIP ACROSS NORTHERN NJ...LOWER HUDSON VALLEY AND
SOUTHERN CT...WITH LITTLE ADDITIONAL PRECIP SOUTH OF THAT LINE.
EXPECTING REDEVELOPMENT THIS EVENING...BUT REMAINS TO BE SEEN JUST
HOW HEAVY THE QPF WILL BE. LATEST RFC AND HPC QPF GUIDANCE SHOWS A
LOWERING TREND...AND WILL FOLLOW SUIT.
STORM TOTAL QPF VALUES GENERALLY LOWERED TO 1.5 TO 2 INCHES ACROSS
THE CWA. COULD HAVE LOCALLY HIGHER AMOUNTS DEPENDING ON TRAINING
OF CELLS THIS EVENING...BUT PRECIP HAS NOT BEEN AS INTENSE AS
EXPECTED...AND FLOODING HAS NOT DEVELOPED.
WINDS STILL REMAIN A CONCERN TONIGHT INTO FRIDAY MORNING. THE
LATEST THINKING IS THAT THE STRONGEST GUSTS WILL OCCUR AFTER
MIDNIGHT TONIGHT AND LASTING THROUGH MID MORNING FRIDAY. THE AREA
IS BASICALLY LOOKING AT TWO TIME PERIODS WITH STRONGER
WINDS...WITH A LULL IN BETWEEN AS THE CENTER OF THE LOW TRAVELS
JUST SOUTH OF LONG ISLAND. WILL KEEP THE STRONGEST WINDS OVER LI
AND COASTAL REGIONS OF CT...AND THERE MAY STILL BE A BRIEF PERIOD
OF WINDS REACHING WIND ADVISORY LEVELS OVER EASTERN PORTIONS OF
LONG ISLAND LATE TONIGHT/EARLY FRI MORNING...BUT CONFIDENCE OF
OCCURRING/COVERAGE IS NOT HIGH ENOUGH AT THIS TIME TO ISSUE AN
ADVISORY. ELSEWHERE...EXPECT GUSTY CONDITIONS...BUT SUB WIND
ADVISORY SUSTAINED AND GUSTS. THE WINDS HIT THEIR PEAK AROUND 12Z
FRIDAY...THEN QUICKLY DIMINISH FROM WEST TO EAST THROUGHOUT THE
DAY FRIDAY AS THE LOW PUSHES OFF TO THE EAST.
THERE IS A MODERATE RISK OF RIP CURRENTS AT ATLANTIC OCEAN BEACHES
TODAY.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
AS THE STORM PULLS AWAY ON FRI RAIN WILL TAPER FROM W TO E. A WEAK
COLD FRONT/SFC TROUGH WILL APPROACH FROM THE W WITH CHC POPS
LINGERING OVER WESTERN ZONES. RAINFALL ASSOCIATED WITH THIS WILL
BE MINIMAL AS ATMOSPHERE WILL BE DRYING AS HIGH PRES BUILDS FROM
THE GREAT LAKES.
DRY WEATHER PREVAILS FRI NIGHT THROUGH SAT WITH THE HIGH BUILDING
TO THE S. TEMPS REBOUND TO NORMAL LEVELS BY SAT.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
MUCH OF SUNDAY SHOULD BE DRY AS WELL WITH CLOUDS LOWERING AND
THICKENING AS A WARM FRONT APPROACHES FROM THE SOUTHWEST...WITH A
CHANCE OF SHOWERS BY SUNDAY NIGHT. WARM FRONT MOVES THROUGH AND
THEN NORTH OF THE REGION BY MONDAY. THEREAFTER...THERE IS A GOOD
DEAL OF MODEL DIVERGENCE AS THE 00Z ECMWF PHASES A NORTHERN AND
SOUTHERN STREAM SYSTEM OVER THE EASTERN GREAT LAKES...PRIMING THE
AREA FOR ROUND OF MODERATE RAINFALL MONDAY NIGHT INTO TUESDAY. THE
12Z GFS DOES NOT REALLY PHASE THE 2 SYSTEMS UNTIL AFTER THE
ASSOCIATED COLD FRONT MOVES THROUGH...WITH THE BULK OF THE
HEAVIEST RAIN REMAINING TO THE NORTH. THE 12Z GEM ALSO KEEPS THE 2
SYSTEMS SEPARATE...BUT THE SOUTHERN STREAM IS DEEPER THAN THE
OTHER 2 MODELS...AND THEREFORE HAS A ROUND OF MODERATE TO HEAVY
RAIN AFFECTING THE AREA BEGINNING MONDAY NIGHT. GIVEN THE MODEL
DIFFERENCES...DID NOT MAKE MUCH IN THE WAY OF CHANGES TO PREVIOUS
FORECAST.
COLD FRONT PUSHES OFF THE EAST COAST BY TUESDAY NIGHT...WITH SOME
LINGERING SHOWERS AND THUNDERSTORMS OVERNIGHT. THE AREA DRIES OUT
FOR WEDNESDAY THROUGH THE END OF THE FORECAST PERIOD AS HIGH
PRESSURE BUILDS IN.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
CURRENT WX EVENT LOOKING TO HAVE LESS SIGNIFICANT LOCAL IMPACT
THAN ORIGINALLY EXPECTED. E-SE FLOW STILL GUSTING TO 25-30 KT
INVOF NYC METRO AND 20-25 MOST ELSEWHERE SHOULD LESSEN SOMEWHAT
THIS AFTERNOON AND BACK A LITTLE MORE E...WITH MVFR CIGS MOST
PLACES. STILL EXPECTING REDEVELOPMENT OF SHOWERS AND ISOLD TSTMS
TO THE WEST LATE THIS AFTERNOON AS WINDS BACK NE...WHICH COULD
IMPACT THE LOWER HUDSON VALLEY AND NYC METRO TERMINALS FROM 22Z-
01Z THIS EVENING... AND AN HR OR TWO LATER FARTHER EAST. EXPECTING
CONTINUED MVFR CONDS WITH THESE SHOWERS...MAYBE BRIEF IFR CONDS
AND SOME ISOLD RUMBLES OF THUNDER.
MVFR CONDS SHOULD CONTINUE OVERNIGHT WITH INCREASING N FLOW.
GRADUAL IMPROVEMENT TO VFR BY EARLY AFTERNOON THEN EXPECTED AT
MOST TERMINALS.
...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 FOR CHANGING FLIGHT
CATEGORIES. BRIEF IFR VSBY AND/OR AN ISOLD TSTM POSSIBLE SOME TIME
BETWEEN 22Z-01Z.
KLGA FCSTER COMMENTS: AMENDMENTS LIKELY FOR CHANGING FLIGHT
CATEGORIES. BRIEF IFR VSBY AND/OR AN ISOLD TSTM POSSIBLE SOME TIME
BETWEEN 22Z-01Z.
KEWR FCSTER COMMENTS: AMENDMENTS LIKELY FOR CHANGING FLIGHT
CATEGORIES. BRIEF IFR VSBY AND/OR AN ISOLD TSTM POSSIBLE SOME TIME
BETWEEN 22Z-01Z.
KTEB FCSTER COMMENTS: AMENDMENTS LIKELY FOR CHANGING FLIGHT
CATEGORIES. BRIEF IFR VSBY AND/OR AN ISOLD TSTM POSSIBLE SOME TIME
BETWEEN 22Z-01Z.
KHPN FCSTER COMMENTS: BRIEF IFR VSBY AND/OR AN ISOLD TSTM
POSSIBLE SOME TIME BETWEEN 22Z-01Z.
KISP FCSTER COMMENTS: BRIEF IFR VSBY AND/OR AN ISOLD TSTM
POSSIBLE SOME TIME BETWEEN 23Z-02Z.
.OUTLOOK FOR 18Z FRI THROUGH TUE...
.FRI...VFR. DIMINISHING N WINDS.
.SAT-SUNDAY MORNING...VFR.
.SUNDAY AFTERNOON-MON...A WEAK FRONTAL SYSTEM PASSING THROUGH
COULD BRING SHOWERS/TSTMS WITH BRIEF MVFR OR LOWER CONDS.
.TUE...A STRONGER FRONTAL SYSTEM MOVING ACROSS COULD BRING
SHOWERS/TSTMS WITH BRIEF MVFR OR LOWER CONDS.
&&
.MARINE...
WINDS AND SEAS WILL INCREASE DURING THE DAY TODAY AS A LOW PRESSURE
SYSTEM APPROACHES FROM THE WEST. EXPECT GENERALLY SCA CONDITIONS ON
ALL WATERS BY THIS AFTN AS GUSTS REACH 25 KT...AND THE OCEAN WATERS
HOVER AROUND 5 FT. BY TONIGHT...WITH THE LOW PASSING JUST TO THE
SOUTH OF LONG ISLAND...EXPECTING GALES ON ALL WATERS. HAVE ISSUED A
GALE WARNING FOR TONIGHT THROUGH MID MORNING FRIDAY TO REFLECT THE
GROWING CONFIDENCE OF THE GALES OCCURRING. WHILE THE WARNING BEGINS
THIS EVENING...THE LATEST TRACK OF THE LOW SUGGESTS THAT THE BETTER
CHC FOR GALE FORCE WINDS TO BE AFTER MIDNIGHT...WITH THE STRONGEST
WINDS THEN AROUND 12Z FRIDAY MORNING. WINDS WILL QUICKLY SUBSIDE
FRIDAY AS THE LOW PUSHES EAST...BRINGING IN SCA CONDITIONS ON ALL
WATERS BY FRI AFTN...AND SUB-SCA WINDS BY FRIDAY NIGHT. LINGERING
SEAS ON THE OCEAN SHOULD REMAIN ABOVE 5 FT THROUGH FRI NIGHT...WITH
SUB-SCA CONDITIONS ON ALL WATERS BY SAT AS HIGH PRESSURE SETS IN.
SUB-SCA CONDITIONS LAST THROUGH THE WEEKEND...WITH SCA CONDITIONS
THEN POSSIBLE AGAIN NEXT WEEK WITH THE NEXT LOW PRESSURE SYSTEM
IMPACTING THE REGION.
&&
.HYDROLOGY...
LATEST DUAL POL STORM TOTAL ACCUM GENERALLY INDICATING 1/2 TO 3/4
INCH QPF ACROSS PARTS OF NJ...NYC...LOWR HUDSON VALLEY AND
SOUTHERN CT WITH LESS THAN 1/2 INCH ELSEWHERE. WITH DRY WEATHER
OVERSPREADING THE REGION FOR MUCH OF THE AFTERNOON...THE RIVERS
AND STREAMS WILL BE ABLE TO RECOVER BEFORE THE NEXT POSSIBLE ROUND
OF PRECIP THIS EVENING. WILL LOWER STORM TOTAL QPF FORECAST TO 1.5
TO 2 INCHES...BUT LOCALLY HIGHER AMOUNTS REMAIN POSSIBLE THIS
EVENING IN ANY CONVECTION.
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.
&&
.TIDES/COASTAL FLOODING...
COASTAL FLOODING ISSUES CONTINUE TO LOOK MINIMAL FOR THIS EVENT. AS
WE ARE BETWEEN A NEW AND FULL MOON...ASTRONOMICAL TIDES ARE AROUND 2
FT BELOW MINOR FLOOD LEVELS. LATEST GUIDANCE IS BRINGING IN ABOUT 1
FT OF SURGE DURING THE TIME OF HIGH TIDE THIS EVENING/OVERNIGHT. THE
STEVENS GUIDANCE DOES BRING SOME OF THE SOUTH SHORE BAYS AND LONG
ISLAND SOUND SITES UP CLOSE TO MINOR FLOOD LEVELS. HOWEVER...IT
MAY BE INCORPORATING STRONGER WINDS THAN FORECAST. SO WILL
CONTINUE TO WITHHOLD FROM ISSUING ANY COASTAL FLOODING PRODUCTS AT
THIS TIME AND STAY WITH THE MORE CONSERVATIVE FORECASTS FOR THE
TIDAL SITES.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...FLOOD WATCH THROUGH SATURDAY MORNING FOR CTZ005>012.
NY...FLOOD WATCH THROUGH FRIDAY EVENING FOR NYZ072>075-078>081-
176>179.
FLOOD WATCH THROUGH SATURDAY MORNING FOR NYZ067>071.
NJ... FLOOD WATCH THROUGH SATURDAY MORNING FOR NJZ002-004-006-
103>108.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ330-
335-338-340-345-350-353-355.
GALE WARNING FROM 6 PM THIS EVENING TO 11 AM EDT FRIDAY FOR
ANZ330-335-338-340-345-350-353-355.
&&
$$
AREA FORECAST DISCUSSION
NWS NEW YORK NY
110 PM EDT THU JUN 13 2013
.SYNOPSIS...
LOW PRESSURE APPROACHES THE REGION THIS AFTERNOON AND THEN PASSES
SOUTH AND EAST OF LONG ISLAND TONIGHT AND FRIDAY. HIGH PRESSURE
BUILDS INTO REGION FOR THE WEEKEND. ANOTHER AREA OF LOW PRESSURE
WILL TRACK ACROSS SOUTHERN CANADA EARLY NEXT WEEK WITH A ITS
FRONTAL SYSTEM IMPACTING THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
LOW PRES NOW ENTERING WESTERN NY/PA...AND IS BEGINNING TO TRACK TO
THE SOUTHEAST. LOWEST PRES FALLS OVER THE LAST 3 HR IS OVER SE
PA...SO THE LOW IS ON TRACK TO APPROACH THE DELMARVA LATER THIS
AFTERNOON.
AS THE FIRST WAVE OF SHOWERS AND THUNDERSTORMS EXITS THE EASTERN
HALF OF THE CWA...AN AREA OF DRY WEATHER WILL MOVE INTO THE
REGION. AS A RESULT...WILL TAPER DOWN POP/QPF FORECAST. WILL CARRY
CHANCE POPS FOR THE REST OF THE AFTERNOON...BUT IF THERE IS ENOUGH
CLEARING AHEAD OF THE LOW...SFC TEMPS WOULD THEN WARM UP...
ALLOWING CAPE VALUES TO RISE. THINK PRECIP WILL FILL IN DURING THE
AFTERNOON...BUT NOT QUITE AS WIDESPREAD AS PREVIOUSLY EXPECTED.
ANOTHER LINE OF SHOWERS AND THUNDERSTORMS ASSOCIATED WITH THE H5
TROUGH/VORT MAX IS TRACKING SOUTHEAST THROUGH WV/KY.
AS THE LOW APPROACHES THIS EVENING...AND PIVOTS AROUND THE BASE OF
AN H5 TROUGH DIGGING INTO THE EAST COAST...WILL SEE SHOWERS
DEVELOPING ONCE AGAIN THIS EVENING. LATEST HRRR GUIDANCE HAS SHOWERS
AND THUNDERSTORMS REDEVELOPING OVER THE AREA AFTER MIDNIGHT
TONIGHT AS THE SFC LOW/H5 VORT MAX PIVOTS AROUND THE BASE OF THE
TROUGH AS IT DIGS INTO THE EAST COAST. LATEST NAM KEEPS THE BULK
OF THE PRECIP ACROSS NORTHERN NJ...LOWER HUDSON VALLEY AND
SOUTHERN CT...WITH LITTLE ADDITIONAL PRECIP SOUTH OF THAT LINE.
EXPECTING REDEVELOPMENT THIS EVENING...BUT REMAINS TO BE SEEN JUST
HOW HEAVY THE QPF WILL BE. LATEST RFC AND HPC QPF GUIDANCE SHOWS A
LOWERING TREND...AND WILL FOLLOW SUIT.
STORM TOTAL QPF VALUES GENERALLY LOWERED TO 1.5 TO 2 INCHES ACROSS
THE CWA. COULD HAVE LOCALLY HIGHER AMOUNTS DEPENDING ON TRAINING
OF CELLS THIS EVENING...BUT PRECIP HAS NOT BEEN AS INTENSE AS
EXPECTED...AND FLOODING HAS NOT DEVELOPED.
WINDS STILL REMAIN A CONCERN TONIGHT INTO FRIDAY MORNING. THE
LATEST THINKING IS THAT THE STRONGEST GUSTS WILL OCCUR AFTER
MIDNIGHT TONIGHT AND LASTING THROUGH MID MORNING FRIDAY. THE AREA
IS BASICALLY LOOKING AT TWO TIME PERIODS WITH STRONGER
WINDS...WITH A LULL IN BETWEEN AS THE CENTER OF THE LOW TRAVELS
JUST SOUTH OF LONG ISLAND. WILL KEEP THE STRONGEST WINDS OVER LI
AND COASTAL REGIONS OF CT...AND THERE MAY STILL BE A BRIEF PERIOD
OF WINDS REACHING WIND ADVISORY LEVELS OVER EASTERN PORTIONS OF
LONG ISLAND LATE TONIGHT/EARLY FRI MORNING...BUT CONFIDENCE OF
OCCURRING/COVERAGE IS NOT HIGH ENOUGH AT THIS TIME TO ISSUE AN
ADVISORY. ELSEWHERE...EXPECT GUSTY CONDITIONS...BUT SUB WIND
ADVISORY SUSTAINED AND GUSTS. THE WINDS HIT THEIR PEAK AROUND 12Z
FRIDAY...THEN QUICKLY DIMINISH FROM WEST TO EAST THROUGHOUT THE
DAY FRIDAY AS THE LOW PUSHES OFF TO THE EAST.
THERE IS A MODERATE RISK OF RIP CURRENTS AT ATLANTIC OCEAN BEACHES
TODAY.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
AS THE STORM PULLS AWAY ON FRI RAIN WILL TAPER FROM W TO E. A WEAK
COLD FRONT/SFC TROUGH WILL APPROACH FROM THE W WITH CHC POPS
LINGERING OVER WESTERN ZONES. RAINFALL ASSOCIATED WITH THIS WILL
BE MINIMAL AS ATMOSPHERE WILL BE DRYING AS HIGH PRES BUILDS FROM
THE GREAT LAKES.
DRY WEATHER PREVAILS FRI NIGHT THROUGH SAT WITH THE HIGH BUILDING
TO THE S. TEMPS REBOUND TO NORMAL LEVELS BY SAT.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
MUCH OF SUNDAY SHOULD BE DRY AS WELL WITH CLOUDS LOWERING AND
THICKENING AS A WARM FRONT APPROACHES FROM THE SOUTHWEST...WITH A
CHANCE OF SHOWERS BY SUNDAY NIGHT. WARM FRONT MOVES THROUGH AND
THEN NORTH OF THE REGION BY MONDAY. THEREAFTER...THERE IS A GOOD
DEAL OF MODEL DIVERGENCE AS THE 00Z ECMWF PHASES A NORTHERN AND
SOUTHERN STREAM SYSTEM OVER THE EASTERN GREAT LAKES...PRIMING THE
AREA FOR ROUND OF MODERATE RAINFALL MONDAY NIGHT INTO TUESDAY. THE
12Z GFS DOES NOT REALLY PHASE THE 2 SYSTEMS UNTIL AFTER THE
ASSOCIATED COLD FRONT MOVES THROUGH...WITH THE BULK OF THE
HEAVIEST RAIN REMAINING TO THE NORTH. THE 12Z GEM ALSO KEEPS THE 2
SYSTEMS SEPARATE...BUT THE SOUTHERN STREAM IS DEEPER THAN THE
OTHER 2 MODELS...AND THEREFORE HAS A ROUND OF MODERATE TO HEAVY
RAIN AFFECTING THE AREA BEGINNING MONDAY NIGHT. GIVEN THE MODEL
DIFFERENCES...DID NOT MAKE MUCH IN THE WAY OF CHANGES TO PREVIOUS
FORECAST.
COLD FRONT PUSHES OFF THE EAST COAST BY TUESDAY NIGHT...WITH SOME
LINGERING SHOWERS AND THUNDERSTORMS OVERNIGHT. THE AREA DRIES OUT
FOR WEDNESDAY THROUGH THE END OF THE FORECAST PERIOD AS HIGH
PRESSURE BUILDS IN.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
...SIGNIFICANT IMPACT WEATHER EVENT FORECAST TODAY INTO FRIDAY...
RAIN NOW STARTING TO OVERSPREAD THE TERMINALS. VFR TO START...BUT
IFR CONDITIONS ARE EXPECTED TO PREVAIL AFTER THE MORNING PUSH. TAFS
MAY BE OFF BY AN HOUR OR TWO BRINGING THE IFR CONDITIONS IN TOO
SOON. RAIN COULD BE HEAVY AT TIMES FROM LATE MORNING ON. ALSO...A
SLIGHT CHANCE OF A THUNDERSTORM FROM LATE MORNING ON IS
POSSIBLE...HOWEVER EXACT TIMING AND PLACEMENT STILL TO LOW TO
INCLUDE THUNDER IN THE TAFS. MODERATE CONFIDENCE IN WIND DIRECTION.
LOW TO MODERATE CONFIDENCE IN SPEED. SUSTAINED/GUSTS MAY BE MORE
OCCASIONAL. SPEEDS COULD BE AT LEAST ANOTHER 5 KT STRONGER THAN WHAT
IS IN THE FORECAST.
...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 THIS MORNING FOR CHANGING
FLIGHT CATEGORIES. GUST MAY BE MORE OCCASIONAL THAN PREVAILING THIS
AFTERNOON. THUNDER IS POSSIBLE THIS AFTERNOON.
KLGA FCSTER COMMENTS: AMENDMENTS LIKELY THIS MORNING FOR CHANGING
FLIGHT CATEGORIES. GUST MAY BE MORE OCCASIONAL THAN PREVAILING THIS
AFTERNOON. THUNDER IS POSSIBLE THIS AFTERNOON.
KEWR FCSTER COMMENTS: AMENDMENTS LIKELY THIS MORNING FOR CHANGING
FLIGHT CATEGORIES. GUST MAY BE MORE OCCASIONAL THAN PREVAILING THIS
AFTERNOON. THUNDER IS POSSIBLE THIS AFTERNOON.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS YELLOW...WHICH IMPLIES
SLANT RANGE VISIBILITY 4-6SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: AMENDMENTS LIKELY THIS MORNING FOR CHANGING
FLIGHT CATEGORIES. GUST MAY BE MORE OCCASIONAL THAN PREVAILING THIS
AFTERNOON. THUNDER IS POSSIBLE THIS AFTERNOON.
KHPN FCSTER COMMENTS: AMENDMENTS LIKELY THIS MORNING FOR CHANGING
FLIGHT CATEGORIES. GUST MAY BE MORE OCCASIONAL THAN PREVAILING THIS
AFTERNOON.
KISP FCSTER COMMENTS: AMENDMENTS LIKELY THIS MORNING FOR CHANGING
FLIGHT CATEGORIES. GUST MAY BE MORE OCCASIONAL THAN PREVAILING THIS
AFTERNOON.
.OUTLOOK FOR 12Z FRIDAY THROUGH MONDAY...
.FRI...CHC SHRA AND SUB-VFR EARLY. VFR PROBABLE BY NOON. NORTH GUSTS
20-25KT POSSIBLE.
.SATURDAY AND SUNDAY...VFR.
.MONDAY...MAINLY VFR...SHOWER/THUNDERSTORM POSSIBLE.
&&
.MARINE...
WINDS AND SEAS WILL INCREASE DURING THE DAY TODAY AS A LOW PRESSURE
SYSTEM APPROACHES FROM THE WEST. EXPECT GENERALLY SCA CONDITIONS ON
ALL WATERS BY THIS AFTN AS GUSTS REACH 25 KTS...AND THE OCEAN WATERS
HOVER AROUND 5 FT. BY TONIGHT...WITH THE LOW PASSING JUST TO THE
SOUTH OF LONG ISLAND...EXPECTING GALES ON ALL WATERS. HAVE ISSUED A
GALE WARNING FOR TONIGHT THROUGH MID MORNING FRIDAY TO REFLECT THE
GROWING CONFIDENCE OF THE GALES OCCURRING. WHILE THE WARNING BEGINS
THIS EVENING...THE LATEST TRACK OF THE LOW SUGGESTS THAT THE BETTER
CHC FOR GALE FORCE WINDS TO BE AFTER MIDNIGHT...WITH THE STRONGEST
WINDS THEN AROUND 12Z FRIDAY MORNING. WINDS WILL QUICKLY SUBSIDE
FRIDAY AS THE LOW PUSHES EAST...BRINGING IN SCA CONDITIONS ON ALL
WATERS BY FRI AFTN...AND SUB-SCA WINDS BY FRIDAY NIGHT. LINGERING
SEAS ON THE OCEAN SHOULD REMAIN ABOVE 5 FT THROUGH FRI NIGHT...WITH
SUB-SCA CONDITIONS ON ALL WATERS BY SAT AS HIGH PRESSURE SETS IN.
SUB-SCA CONDITIONS LAST THROUGH THE WEEKEND...WITH SCA CONDITIONS
THEN POSSIBLE AGAIN NEXT WEEK WITH THE NEXT LOW PRESSURE SYSTEM
IMPACTING THE REGION.
&&
.HYDROLOGY...
LATEST DUAL POL STORM TOTAL ACCUM GENERALLY INDICATING 1/2 TO 3/4
INCH QPF ACROSS PARTS OF NJ...NYC...LOWR HUDSON VALLEY AND
SOUTHERN CT WITH LESS THAN 1/2 INCH ELSEWHERE. WITH DRY WEATHER
OVERSPREADING THE REGION FOR MUCH OF THE AFTERNOON...THE RIVERS
AND STREAMS WILL BE ABLE TO RECOVER BEFORE THE NEXT POSSIBLE ROUND
OF PRECIP THIS EVENING. WILL LOWER STORM TOTAL QPF FORECAST TO 1.5
TO 2 INCHES...BUT LOCALLY HIGHER AMOUNTS REMAIN POSSIBLE THIS
EVENING IN ANY CONVECTION.
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.
&&
.TIDES/COASTAL FLOODING...
COASTAL FLOODING ISSUES CONTINUE TO LOOK MINIMAL FOR THIS EVENT. AS
WE ARE BETWEEN A NEW AND FULL MOON...ASTRONOMICAL TIDES ARE AROUND 2
FT BELOW MINOR FLOOD LEVELS. LATEST GUIDANCE IS BRINGING IN ABOUT 1
FT OF SURGE DURING THE TIME OF HIGH TIDE THIS EVENING/OVERNIGHT. THE
STEVENS GUIDANCE DOES BRING SOME OF THE SOUTH SHORE BAYS AND LONG
ISLAND SOUND SITES UP CLOSE TO MINOR FLOOD LEVELS. HOWEVER...IT
MAY BE INCORPORATING STRONGER WINDS THAN FORECASTED. SO WILL
CONTINUE TO WITHHOLD FROM ISSUING ANY COASTAL FLOODING PRODUCTS AT
THIS TIME AND STAY WITH THE MORE CONSERVATIVE FORECASTS FOR THE
TIDAL SITES.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...FLOOD WATCH THROUGH SATURDAY MORNING FOR CTZ005>012.
NY...FLOOD WATCH THROUGH FRIDAY EVENING FOR NYZ072>075-078>081-
176>179.
FLOOD WATCH THROUGH SATURDAY MORNING FOR NYZ067>071.
NJ... FLOOD WATCH THROUGH SATURDAY MORNING FOR NJZ002-004-006-
103>108.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ330-
335-338-340-345-350-353-355.
GALE WARNING FROM 6 PM THIS EVENING TO 11 AM EDT FRIDAY FOR
ANZ330-335-338-340-345-350-353-355.
&&
$$
SYNOPSIS...
NEAR TERM...SEARS/MPS
SHORT TERM...
LONG TERM...
AVIATION...BC/GOODMAN
MARINE...
HYDROLOGY...
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
507 AM EDT Thu Jun 13 2013
...THERE IS A POTENTIAL FOR SEVERE THUNDERSTORMS THIS AFTERNOON AND
EVENING WITH THE PRIMARY THREAT BEING DAMAGING WINDS...
.NEAR TERM [Today and Tonight]...
Very interesting forecast across the region over the next 24 hours,
as the very hot conditions which were observed across the CWA on
Wednesday will continue over the region today. High temps are once
again expected to reach the upper 90s across much of the interior
this afternoon, with lower to middle 90s as we gradually approach
the coast. However, the upper level ridging (and low level NW flow)
which helped to suppress and limit the afternoon Sea Breeze
convection to a general area confined near the coast, will be
retrograding westward today, which will allow a shortwave trof and
weak Cold Frontal boundary to approach from the NW tonight. While
PoPs from the Sea Breeze convection are only expected to be slightly
higher across the region this afternoon (ranging from 20% to the NW
to 40% to the SE), it is the potential MCS development out ahead of
the Cold Front which has us quite a bit more concerned for tonight.
In fact, the Storm Prediction Center (SPC) has placed all of our AL
and GA zones in a Slight Risk for Severe Thunderstorms, with the
main threat being damaging wind gusts. The main question for our
region will be the timing of this convection, which we currently
believe will be mainly in the 00 to 06 UTC window this evening over
our northern zones (with 40% PoPs which may need later adjustment),
with the earlier the arrival likely equating to greater potential
for severe storms. This potential will at least be somewhat tied
to evening temperatures, which could still be around 90 degrees, so
when combined with SFC dewpoints in the lower 70s, will still
support a very unstable environment for the convection to develop
and propagate southward. Therefore, all interests in our CWA should
keep abreast of the latest forecasts, briefing information, and
updates from both our local office and the Storm Prediction Center
should a Severe Thunderstorm Watch become necessary later today or
tonight. In any event, most of of the Hi-Res models are indicating a
definitive weakening trend in the convection during the overnight
hours, so the threat should be diminishing as the night goes on.
&&
.SHORT TERM [Friday Through Saturday Night]...
The short term period begins with an upper level pattern much like
the one our area has been under for the past couple of days. The
only difference being now an upper level trough is moving off the
eastern seaboard, and deep layer ridging is advancing eastward. A
weak surface cold front, associated with the upper level trough,
is expected to be just north of the Florida border by 12Z Friday.
Therefore, expect an enhanced PoP ahead of the cold front as it
slowly advances southward. The Storm Prediction Center has a 5%
probability of severe weather outlined for ahead of the surface
cold front. If severe weather should occur, it will likely be high
winds. Looking at the equivalent potential temperature difference
between the surface and the 500-700mb layer, values are in the
lower 30s, which would indicate a marginal potential for damaging
winds being transported to the surface. The mid-level temperatures
are too warm to support the possibility of severe hail making it
down the surface.
By early Saturday morning, the cold front should stall out south of
our CWA. Therefore expect drier conditions throughout the day on
Saturday with no POPs expected. PWATs throughout the area will be
less than 1.3, which is abnormally low for this time of year. The
surface high pressure will quickly push eastward through the day
on Saturday with winds transitioning from northerly to easterly.
By the end of the near term period winds will be southerly,
returning our area to our normal summertime weather pattern.
&&
.LONG TERM [Sunday through Wednesday]...
After the potential system passes Thursday night, high pressure
aloft and at the surface will build eastward and be the main
synoptic scale influence on the forecast area`s weather through
Tuesday. On Tuesday, another shortwave will propagate through the
upper level ridge and set up a pattern similar to Thursday night
(see short term). Highest PoPs in the forecast period are Tuesday
and Wednesday. Expecting highs in the 90s and lows in the low 70s
through the long term period.
&&
.AVIATION...
[Through 12 UTC Friday] Although generally VFR conditions are once
again expected to prevail for the majority of the overnight period,
there are once again enough discrepancies both within the Hi-Res
guidance (the HRRR and the NARRE), and between this and the
numerical guidance to make the fcst a bit tricky. It appears that
the HRRR is unusually a bit pessimistic (but does appear to have the
likely favored areas for possible restrictions), so used a blend
with persistence. Once again, believe DHN and ECP will need to be
monitored the most closely should IFR of LIFR Vis/Cigs develop
towards morning. During the afternoon and next evening hours, rain
chances will be greater across the area than the previous 2 days, as
showers and storms may form both along the Sea Breeze Front
initially, and on the southward moving Cold Frontal boundary
thereafter. Used convective Prob30 groups to account for this, with
the timing from south to north, and did include gusty winds as some
of the thunderstorms could be strong to severe.
&&
.MARINE...
With the approach of a surface cold front, the pressure gradient
will tighten allowing for increased winds. Beginning this
afternoon, small crafts should exercise caution with winds
expected to be 15-20 knots through early Friday morning. A chance
for thunderstorms is expected through the day on Friday.
&&
.FIRE WEATHER...
Red Flag or near Red Flag conditions are not anticipated across the
Tri-State area for the next several days.
&&
.HYDROLOGY...
The Ochlockonee River at Thomasville is in action stage and may
rise slightly with rain tomorrow night, but it is not expected to
reach minor flood stage. MMEFS shows no sites are forecast to
reach flood stage in the near future. Although there is potential
for some severe thunderstorms Thursday night, WPC QPF for our area
is 0.25" or less and is not expected to cause significant rises on
area rivers.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 96 75 94 71 93 / 30 20 30 10 10
Panama City 91 78 88 77 87 / 30 10 30 20 10
Dothan 99 74 94 70 95 / 20 40 20 0 10
Albany 99 74 93 70 93 / 20 40 10 0 10
Valdosta 97 74 95 70 95 / 40 30 30 10 10
Cross City 92 73 91 72 92 / 30 20 30 20 10
Apalachicola 89 77 87 76 86 / 20 10 30 20 10
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
NEAR TERM...Gould
SHORT TERM...Navarro/Harrigan
LONG TERM...Moore
AVIATION...Gould
MARINE...Navarro/Harrigan
FIRE WEATHER...Gould
HYDROLOGY...Moore
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1145 PM CDT WED JUN 12 2013
.UPDATE...
UPDATED AVIATION SECTION.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 225 PM CDT WED JUN 12 2013
HOT HUMID CONDITIONS PREVAIL ACROSS THE FOUR STATE REGION WITH
HEAT INDEX VALUES FROM THE UPPER 90S TO JUST ABOVE 100F. LAKE
WIND ADVISORY OK FOR NOW AND WILL RUN THROUGH EARLY EVENING WITH
GUSTY SOUTHWEST WINDS CONTINUING.
WVAPOR LOOP SHOWS A VIGOROUS WAVE MOVING INTO SW MINNESOTA AND
SHOULD BE THE FOCUS FOR SIGNIFICANT SEVERE WEATHER OFF TO OUR
NORTH FROM PORTIONS OF IOWA INTO ILLINOIS/INDIANA AND OHIO. THE
QUESTION FOR OUR AREA...IS HOW FAR SOUTH AND WEST CONVECTION WILL
DEVELOP WITH THIS MID LEVEL LOW AND ASSOC SURFACE FRONT THAT WILL
MOVE THROUGH THE REGION LATER TONIGHT INTO EARLY THURSDAY MORNING.
THE HIGH RESOLUTION/MESOSCALE MODELS ARE VARIABLE. A COUPLE OF
4KM MODELS DEVELOP CONVECTION ALL THE WAY TO THE MISSISSIPPI
RIVER. WHILE VARIANTS OF THE HRRR STANDARD AND ENSEMBLE COMPOSITE
DATA SUGGEST A LIMITED CHANCE INTO THE KEVV TRI-STATE IF ANYTHING
AT ALL...AND NOTHING WEST AND SOUTH. GIVEN THE STRONG VEERING MID
LEVEL FLOW AND FALLING HEIGHTS/WEAKENING CAP...THINK IT PRUDENT WE
MAINTAIN POPS FOR CONVECTION TONIGHT INTO MIDDAY THURSDAY FOR NOW
WITH MID RANGE CHANCE POPS KEVV TRI-STATE...LOWERING TO SLIGHT
CHANCE TOWARD THE I-55 CORRIDOR. WOULD NOT BE SURPRISED EITHER WAY
HOW THINGS PAN OUT. AND SHOULD CONVECTION TAKE SHAPE IN OUR
AREA...IT COULD BE SEVERE WITH DAMAGING WINDS THE MAIN HAZARD.
HIGH PRESSURE WILL BUILD IN AND RESULT IN DRY WEATHER FOR THURSDAY
NIGHT THROUGH FRIDAY NIGHT. IN THE WAKE OF THE FRONT AND WITH THE
HIGH BUILDING IN...WE WILL RID THE SHORT LIVED HEAT EPISODE.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 225 PM CDT WED JUN 12 2013
AT THE BEGINNING OF THIS PERIOD A VERY SHARP...BUT NARROW AMPLITUDE
NORTH TO SOUTH ORIENTED MID-LEVEL RIDGE IS PARKED JUST TO THE WEST
OF THE WFO PAH FORECAST AREA...EXTENDING SOUTH TO THE GULF OF
MEXICO. THE MEAN MOISTURE FLOW AT LOW LEVELS IS ORIENTED FROM THE
SOUTHEAST...WITH HIGH LEVEL MOISTURE MOVING OVER THE RIDGE AND
DIVING SHARPLY SOUTH-SOUTHEAST OVER THE WFO PAH FORECAST AREA FROM
THE UPPER MIDWEST. THERE WILL BE A FAIRLY NARROW...BUT ROBUST
CORRIDOR OF INSTABILITY AND SHEAR TO WORK WITH...BUT THIS SHOULD BE
ENOUGH TO WARRANT THE MENTION OF SHOWERS AND THUNDERSTORMS FROM
NORTHWEST TO SOUTHEAST AS THE WEEKEND PROGRESSES. A SERIES OF MINOR
IMPULSES ROTATING AROUND THE MID-LEVEL RIDGE IN THE MUCH FASTER
WESTERLIES MAY GENERATE NON-DIURNAL RAIN CHANCES. THE BIG KEY WILL
BE THE DEGREE OF DEEP LAYER MOISTURE AVAILABLE FOR CONVECTIVE
ACTIVITY. FOR NOW...KEEPING MOST OF THE WEEKEND RAIN CHANCES IN THE
30 TO 50 PERCENT RANGE FOR POPS.
BY THE TIME SUNDAY AFTERNOON AND EVENING ROLLS AROUND THE MID-LEVEL
RIDGE FLATTENS...SUPPORTING A MUCH MORE ENERGETIC WESTERLY FLOW AND
FORCING OVER THE AREA. THE TRAJECTORY OF MOISTURE IS ALSO MORE
SOUTHERLY AND TARGETED TOWARD THE WFO PAH FORECAST AREA. WITH THIS
IN MIND...RAIN CHANCES WERE INCREASED FROM HIGH CHANCE TO LIKELY BY
EARLY MONDAY...FOCUSED OVER THE SOUTHERN 2/3RDS OF THE WFO PAH
FORECAST AREA. THE RAIN CHANCES ARE ALSO AIDED BY A PROGRESSIVE
SHORTWAVE EXPECTED TO MOVE THROUGH THE AREA DURING THE DAY MONDAY. A
MORE DOMINANT RIDGING TAKES PLACE LATE MONDAY...BRIEFLY REDUCING
CHANCES FOR RAIN DURING THE EVENING HOURS. HOWEVER...UNTIL RIDGING
ALOFT CAPS THE ATMOSPHERE BY MID-WEEK...ANTECEDENT SURFACE
BOUNDARIES/STATIONARY FRONTS SHOULD SUPPORT A SMALL DIURNAL CHANCE
FOR SHOWERS AND THUNDERSTORMS.
GIVEN THE TRAJECTORY OF THE MOISTURE AND VARIABLE CLOUD COVER...THE
HEAT INDEX VALUES SHOULD NOT BE AS STRESSFUL AS WHAT WE ARE
EXPERIENCING TODAY. OTHERWISE...LITTLE CHANGE IN MAX/MIN
TEMPERATURES THROUGH THE PERIOD.
&&
.AVIATION...
ISSUED AT 1145 PM CDT WED JUN 12 2013
WINDS THROUGH THE 06Z TAF PERIOD ARE NOT EXPECTED TO GO BELOW 10
KTS. THE WIND IS BEING DRIVEN BY THE PRESSURE DIFFERENCE BETWEEN
HIGH PRESSURE TO THE SOUTH OF OUR REGION...AND A VIGOROUS LOW
PRESSURE SYSTEM SWEEPING ACROSS THE NRN MIDWEST. THE SYSTEM IS
EXPECTED TO DRIVE A DRY COLD FRONT THROUGH THE REGION EARLY
THU...YIELDING A WIND SHIFT TO THE NW. ATTM...NO PCPN OR VSBY
RESTRICTION IS IN THE KEVV/KOWB TAFS DUE TO THE LIMITED CHANCE OF
CONVECTIVE ACTIVITY. MVFR CIGS ARE POSSIBLE IN THE NRN THIRD OF THE
REGION FOR A FEW HOURS THU MORNING.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GAYLORD MI
121 PM EDT THU JUN 13 2013
.SYNOPSIS...
ISSUED AT 351 AM EDT THU JUN 13 2013
COOLER AND LESS HUMID WEATHER HAS ITS SIGHTS SET ON NORTHERN
MICHIGAN AS WE WRAP UP THE WORK WEEK...AS CANADIAN HIGH PRESSURE
BUILDS FROM THE NORTHERN PLAINS THROUGH THE GREAT LAKES. THERE IS
AN OUTSIDE CHANCE OF A SHOWER IN SPOTS TODAY...BEFORE DRY WEATHER
RETURNS TONIGHT THROUGH SATURDAY MORNING. A COUPLE MORE SHOWERS OR
EVEN A RUMBLE OF THUNDER ARE POSSIBLE LATER SATURDAY...WITH A FEW
MORE CHANCES FOR RAIN EARLY NEXT WEEK. THAT WON`T LAST TOO LONG
THOUGH...AS HIGH PRESSURE AGAIN RETURNS WITH SEASONABLE BUT DRY
WEATHER TOWARD MIDWEEK OF NEXT WEEK.
&&
.UPDATE...
ISSUED AT 1255 PM EDT THU JUN 13 2013
CLOUDS ARE INCREASING ACROSS THE FORECAST AREA, WITH A CU FIELD IN
NE LOWER, A STRATUS DECK IN NW LOWER AND WHAT LOOKS TO BE A SC
DECK IN E UPPER. UPSTREAM, IN LAKE SUPERIOR, AND NORTH, THE CLOUDS
ARE BEGINNING TO MIX OUT ALONG THE EDGE, WHICH IS GOING ALONG WITH
THE MODEL IDEA. SO UPPED THE AMOUNT OF CLOUDS IN N LOWER AS THE CU
FIELD INCREASES. IN E UPPER THE CLOUD MASS SHOULD START TO
DIMINISH OVER THE NEXT COUPLE OF HOURS AS THE DRY AIR WORKS INTO
THE REGION. RUC ANALYSIS SHOWS THAT THE 500 MB TROUGH AXIS IS
ABOUT THROUGH, SO THAT THE SUBSIDENCE WILL ADD TO THE DRYING.
OTHERWISE, THE REST OF THE FORECAST LOOKS GOOD.
UPDATE ISSUED AT 1000 AM EDT THU JUN 13 2013
STRATUS CLOUDS IN C AND E UPPER THIS MORNING ARE BEGINNING TO MIX
OUT, AS THE STRATUS IS EXPECTED TO TRANSITION TO CU OR SC. THIS
SAME POOL OF MOISTURE HAS MADE IT INTO NW LOWER WITH STRATUS
BEGINNING TO SPREAD ALONG THE LAKE MICHIGAN SHORE FROM NEAR CVX TO
FKS. THIS TOO IS EXPECTED TO THIN AND TRANSITION TO CU. MAIN
CONCERN IS THE CLOUD MASS IN ONTARIO NORTH OF ANJ. MODELS HAVE
BEEN ADVERTISING LIGHT RAIN, IN NE LOWER. THIS SEEMS GOOD WITH
DRIZZLE BEING REPORTED IN CYLD. THIS CLOUD MASS IS ASSOCIATED WITH
THE 500 MB SHORTWAVE TROUGH DROPPING DOWN THROUGH THE FORECAST
AREA THIS MORNING. BY THE AFTERNOON, THE SHORTWAVE WILL BE THROUGH
THE FORECAST AREA AND THE MOISTURE EXPECTED TO CONTINUE TO MIX
OUT.
UPDATE ISSUED AT 640 AM EDT THU JUN 13 2013
HIGH CLOUDS THINNING OUT QUICKLY ACROSS THE REGION LEAVING PARTLY
TO MOSTLY SUNNY SKIES TO START THE DAY. BUT...LOW CLOUDS (STRATUS)
STARTING TO EXPAND ACROSS THE U.P. AHEAD OF UPSTREAM SHORT WAVE.
MODEL RH FORECASTS SUGGEST LOWER CLOUDS MAY CONTINUE TO EXPAND
DOWN ACROSS A GOOD PORTION OF THE CWA OVER THE NEXT SEVERAL
HOURS...ALTHOUGH THAT MAY BE OFFSET BY HEATING/MIXING. HAVE
TWEAKED SKY FORECASTS TO REFLECT SUNNIER START TO THE DAY THEN
TRENDING CLOUDIER LATE MORNING INTO THE AFTERNOON.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 351 AM EDT THU JUN 13 2013
MCS/SEVERE WEATHER ONGOING ACROSS THE LOWER GREAT LAKES/OHIO VALLEY
THIS MORNING...SPURRED ON BY MID LEVEL SHORT WAVE ADVANCING THROUGH
THE REGION. NRN EDGE OF MCS RAIN SHIELD JUST SKIRTING THE SRN TIER
OF COUNTIES...PRETTY MUCH AS EXPECTED. TO THE NORTH...ANOTHER SHORT
WAVE NOTED OVER ONTARIO DROPPING S/SE TOWARD THE STATE. SPOTTY
SHOWER ACTIVITY NOTED WITH THIS FEATURE.
TODAY...SHORT WAVE TO THE NORTH WILL ROTATE DOWN THROUGH THE REGION
BRINGING VARYING CLOUD COVER. LOWER HEIGHTS/COOLER TEMPS ALOFT AND
DAYTIME HEATING BRINGS SOME POTENTIAL FOR AFTERNOON INSTABILITY AND
A FEW SHOWERS TO DEVELOP PER INHERITED FORECAST. UNMODIFIED FORECAST
SOUNDINGS DOES REVEAL ONE TO TWO HUNDRED J/KG OF CAPE THIS
AFTERNOON. HOWEVER...MODEL SFC DEWPOINTS LOOK A BIT OVERDONE.
MODIFIED FORECAST SOUNDINGS USING MOS GUIDANCE DEWPOINTS AROUND 50F
REDUCES MLCAPE VALUES TO NEARLY NOTHING THIS AFTERNOON. THUS...VERY
TEMPTED TO PULL POPS. BUT...GIVEN THAT THERE ARE SHOWERS UPSTREAM
WITH THE WAVE CURRENTLY...AND ALL GUIDANCE PRODUCES SOME LIGHT
PRECIP...WILL KEEP CHANCY POPS INTACT.
TONIGHT...SHORT WAVE EXITS OFF TO THE SOUTHEAST BY EVENING WITH
DRIER AIR/CLEARING SKIES TAKING SHAPE ACROSS NRN MICHIGAN. MAY GET
RATHER COOL...BUT WE DO KEEP A BIT OF A PRESSURE GRADIENT ACROSS THE
REGION THROUGH THE NIGHT AND PERHAPS A LIGHT NORTHERLY WIND. HAVE
NUDGED FORECAST LOW TEMPS UPWARD A COUPLE DEGREES...UPPER 30S TO
MIDDLE 40S. COLDER NIGHT LOOKS TO BE FRIDAY NIGHT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 351 AM EDT THU JUN 13 2013
LIKE COOLER TEMPS AND LOW HUMIDITY? WE GOT THAT COVERED! ALSO LIKE
WARMER AND A BIT MORE HUMID (I.E. MORE JUNE-LIKE) WEATHER? WE ALSO
HAVE THAT COVERED OVER THE NEXT 7 DAYS...WITH A RATHER CHANGEABLE
PERIOD OF WEATHER SET TO CONTINUE ACROSS THE NORTHWOODS AS WE ROLL
THROUGH MID MONTH. THIS IS NOT UNLIKE THE PAST MONTH OR SO...WHICH
HAS SEEN SIMILAR UP AND DOWN WEATHER ACROSS THE REGION...WITH THE
CULPRIT THIS TIME BEING A RATHER STABLE 4-WAVE HEMISPHERIC SETUP
FEATURING ANCHOR TROUGHING NEAR THE BERING SEA/NORTH PACIFIC AND
ALSO INTO EASTERN CANADA. THIS SETUP CONTINUES TO PLACE NORTHERN
MICHIGAN IN THE PRECARIOUS POSITION OF BEING NEAR BOTH UPPER RIDGING
(BUILDING THROUGH THE PLAINS/MIDWEST) AND UPPER TROUGHING (BUILDING
THROUGH CANADA)...HENCE THE BIG SWINGS WE HAVE SEEN FROM TIME TO
TIME THE PAST 3-4 WEEKS.
NOT MUCH CHANGE IS FORESEEN OVER THE NEXT 7-10 DAYS...AS INITIAL
UPPER TROUGHING INTO LATE WEEK IS BRIEFLY REPLACED BY BUILDING MID
LEVEL RIDGING INTO THE WEEKEND. THAT SETUP WILL BE SHORT-LIVED...
AS HEIGHTS BEGIN TO FALL THROUGH EARLY NEXT WEEK AS RENEWED
TROUGHING OFF THE PACIFIC NORTHWEST COAST HELPS PUMP SUMMERTIME
RIDGING ACROSS THE ROCKIES WHILE ALSO ALLOWING DOWNSTREAM HEIGHTS TO
FALL THROUGH CENTRAL AND EASTERN CANADA...AND EVENTUALLY THE GREAT
LAKES TOWARD TUESDAY AND WEDNESDAY.
IN THE MEANTIME...REALLY NO WEATHER OF NOTE FRIDAY INTO THE FIRST
HALF OF SATURDAY...AS LOW LEVEL RIDGING SLIDES FROM THE UPPER
MIDWEST TO A POSITION OVERHEAD BY FRIDAY NIGHT. THAT SETUP WILL
DELIVER COOLER AND MUCH LESS HUMID CONDITIONS...WITH VERY LITTLE IN
THE WAY OF ANY CLOUDS (MAYBE A LITTLE CU FRIDAY AFTERNOON?). LOWS
FRIDAY NIGHT CONTINUE TO LOOK CHILLY...WITH READINGS WELL INTO THE
40S EVERYWHERE...AND LIKELY WELL INTO THE 30S FOR INLAND AREAS AS
FRIDAY AFTERNOON DIURNAL MIXING KICKS DEW POINTS DOWN INTO THE
28-34F RANGE. NOT OUT OF THE QUESTION WE COULD SEE SOME FROST FOR
THE USUAL COLD SPOTS...BUT THIS SHOULD BE MORE THE EXCEPTION THAN
THE RULE...SO NO HWO MENTION JUST YET.
CLOUDS LOOK TO THICKEN ON SATURDAY AS MID LEVEL WARM ADVECTION
ASCENT KICKS INTO GEAR OVER THE WESTERN LAKES. AN AXIS OF MUCH
STEEPER MID LEVEL LAPSE RATES IS ALSO PROGGED TO WORK THROUGH THE
WESTERN LAKES ROUGHLY 18-00Z...SUPPORTING THE NOTION OF SOME
ELEVATED CONVECTION (EFFECTIVE CAPE VALUES PERHAPS UP TO 300 J/KG)
PERHAPS TRYING TO WORK THROUGH THE REGION...MAINLY AFTER 21Z.
HOWEVER...RATHER DRY SUB-700MB LAYER AND BEST LOW LEVEL JET
FORCING/THETA-E RIDGING POINTING TOWARD SOUTHERN LAKE MICHIGAN
SUGGESTS THAT NOTHING MUCH MORE THAN SOME SPRINKLES/LIGHT SHOWERS
MAY ACTUALLY SURVIVE ACROSS THE AREA THROUGH THE EVENING.
COULD SEE A FEW LINGERING SHOWERS INTO SUNDAY AS A WEAK UPPER
TROUGH/BETTER MOISTURE AXIS SLIPS THROUGH THE REGION...BUT
CONFIDENCE IN ANY WIDESPREAD COVERAGE IS VERY LOW...AND HONESTLY CAN
FORESEE MUCH OF THE DAY (IF NOT ALL OF IT) BEING DRY. ALSO STARTING
TO GET THE FEELING THAT THE REMAINDER OF THE FORECAST PERIOD WILL BE
DRY...THOUGH CAN`T RULE OUT A FEW MORE SHOWERS LATER MONDAY/MONDAY
NIGHT AS OUR NEXT UPPER TROUGH SWINGS THROUGH. AFTER THAT...BACK TO
DRY AND LESS HUMID WEATHER TUESDAY INTO WEDNESDAY (MAYBE NEXT
THURSDAY TOO) AS LOW LEVEL RIDGING ONCE AGAIN BUILDS FROM CENTRAL
CANADA DOWN INTO THE NORTHERN LAKES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 114 PM EDT THU JUN 13 2013
CLOUDS ARE THE MAIN CONCERN FOR THE AFTERNOON. AT APN, EXPECT THAT
THE WIND COMING OFF OF LAKE HURON WILL KEEP THE CLOUDS AT BAY
DURING THE AFTERNOON. AT PLN, THE CLOUDS WILL MIX OUT IN A FEW
HOURS, SO THAT WE EITHER GO SCT, OR A CIG THAT IS VFR. AT TVC AND
MBL, THE STRATUS DECK IS HANGING TOUGH. MORE MOISTURE IS UPSTREAM,
AND PROBABLY WON`T START TO DIMINISH THE CLOUD DECK UNTIL AFTER
SUNSET AS THE DRIER AIR MOVES IN. SO EXPECT TREND FOR THE CLOUDS
TO GO FROM IFR TO MVFR, AND THEN CLEAR OVERNIGHT. LOOKING AHEAD,
ONCE THE SKY CLEARS OUT TONIGHT, THE SKY WILL REMAIN CLEAR THROUGH
THE DAY FRIDAY. WINDS WILL BE LIGHT AS THE CORE OF THE HIGH
SETTLES INTO THE UPPER GREAT LAKES.
&&
.MARINE...
ISSUED AT 351 AM EDT THU JUN 13 2013
GUSTY NORTHERLY WINDS DEVELOP ON THE LAKES TODAY...AND HIGH
PRESSURE BUILDS OUT OF CANADA INTO THE GREAT LAKES. WIND GUSTS UP
TO 20 KNOTS AND 2 TO 4 FOOT WAVES ANTICIPATED...JUST SHY OF SMALL
CRAFT ADVISORY CRITERIA. WINDS DIMINISH TONIGHT AND REMAIN ON THE
LIGHTER SIDE THROUGH FRIDAY.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...JL
SYNOPSIS...DL
SHORT TERM...BA
LONG TERM...DL
AVIATION...JL
MARINE...BA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
120 PM EDT THU JUN 13 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 443 AM EDT THU JUN 13 2013
LOTS OF STRONG TSRA AND LIGHTNING OVER THE LOWER GREAT LAKES AND
OHIO VALLEY THIS MORNING AHEAD OF STRONGER SHORTWAVE TROUGH AND SFC
LOW/WARM FRONT CROSSING THAT AREA. CLOSER TO HOME...WV LOOP
INDICATES NORTHERN BRANCH TROUGHING CLOSE BY OVER ONTARIO INTO
QUEBEC. MAIN WAVE WITHIN THAT TROUGH IS SLIDING SOUTH OF JAMES BAY
BUT ASSOCIATED LOW-LEVEL TROUGH AXIS IS JUST TO NORTH OF LK SUPERIOR
AS OF 05Z. AS THE SHORTWAVE MOVES INTO QUEBEC EXPECT THE SFC-H85
TROUGH TO DROP ACROSS UPR LAKES THIS MORNING. SFC TEMPS IMMEDIATELY
IN WAKE OF TROUGH IN ONTARIO NOT TOO DIFFERENT THAN CURRENT READINGS
OVER UPR MICHIGAN. COOLING AT 925-850MB IS SEEN THOUGH WITH H85
TEMPS DOWN TO +8C AT CWPL WHILE READINGS AT MPX/GRB AND APX WERE
AROUND +13C. SIMILAR COOLING AT 925MB WITH +20C AT APX FALLING OFF
TO +10C AT CWPL AND +13C AT CWZC /MOOSONEE ONTARIO AT SOUTH SHORE OF
JAMES BAY/. AT 00Z...ONLY UPSTREAM SOUNDING THAT SHOWED LOW-LEVEL
MOISTURE WAS CWZC AND NIGHTTIME SATELLITE IMAGERY AND AVAILABLE OBS
IN ONTARIO ARE SHOWING SOME SCT-BKN MVFR CLOUDS THUS FAR...THOUGH
07Z IMAGERY INDICATES LOW CLOUDS MAY BE STARTING TO FORM OVR HURON
MOUNTAINS. MODELS COMPARED WELL TO EACH OTHER INITIALIZING SFC
THROUGH H5 FEATURES UPSTREAM. NAM INITIALIZED SOUNDINGS AT CWPL AND
CWZC WELL. WILL LEAN ON THE NAM AND RUC13 FOR LOW-LEVEL MOISTURE
FORECASTS FOR TODAY OVR CWA.
FROM A FORECAST STANDPOINT...ENCOURAGED TO SEE LOWER CLOUDS
STARTING TO FORM. THINK IDEA OF BKN LOW CLOUDS THIS MORNING STILL
ON TRACK...ESPECIALLY FOR UPSLOPE AREAS OF NCNTRL UPR MICHIGAN. HAVE
STRUGGLED ON WHAT TO DO WITH DRIZZLE CHANCES. WAS GOING TO PULL
MENTION BASED ON RUC SOUNDINGS WHICH SHOWED LINGERING DRYING BENEATH
HIGHER MOISTURE 950-900MB. ULTIMATELY DECIDED TO KEEP MENTION IN FOR
HIGHER TERRAIN OF MARQUETTE COUNTY AS T/TD DEPRESSION AT STDM4
HAS STEADILY NARROWED OVER THE LAST FEW HOURS. THINK THIS MOISTENING
COMBINED WITH UPSLOPE FLOW COULD STILL RESULT IN LGT DRIZZLE OR
SPRINKLES. DRIZZLE WILL ONLY BE AROUND FOR THE MORNING. ONCE CLOUDS
SET UP...THINK THEY MAY STUBBORN TO LEAVE AS THERMAL TROUGHING FM
925-850MB PERSISTS ALONG WITH A CYCLONIC CONVERGENT NNE FLOW
925-850MB. KEPT BKN CLOUDS IN THROUGH EARLY AFTN WITH SCT CLOUDS
CLOUDS STAYING AROUND THROUGH MID AFTN IN THOSE UPSLOPE AREAS.
EVEN AWAY FM FAVORED AREAS NEAR LK SUPERIOR...THERMAL TROUGHING AND
DAYTIME HEATING SHOULD ACT TO INCREASE CU FOR A WHILE BEFORE
CLOUDS SCATTER OUT LATE TODAY. EXPECT RAPID CLEARING OF SKIES
LATE THIS AFTN/EARLY THIS EVENING AS SHARP 925-850MB DRYING WITH
DWPNT DEPRESSIONS OVER 15C SURGES INTO THE REGION FROM ONTARIO.
ONE ITEM TO NOTE ABOUT TODAY. A MODERATE SWIM RISK IS IN PLACE FOR
SHORELINES OF MARQUETTE AND ALGER COUNTIES AS WAVES BUILD TO 2 TO 4
FEET. LOWERING WAVES WILL LESSEN THE SWIM RISK BY THIS EVENING.
FOR TONIGHT...A COOL NIGHT IN STORE DUE TO THE CLEARING SKIES AND
LIGHT WINDS AS HIGH PRESSURE RIDGE CURRENTLY OVER MANITOBA DROPS
ACROSS REGION. WINDS FCST TO BECOME CALM OVER INTERIOR WEST CWA
WHICH WILL RESULT IN TEMPS FALLING INTO THE UPR 30S...MAYBE EVEN MID
30S. CURRENT READINGS BENEATH THE HIGH IN MANITOBA HAVE ALREADY INTO
UPR 30S AS OF 07Z. KEPT THE FROST MENTION FOR INTERIOR WEST...BUT IT
REMAINS TOO ISOLD TO MENTION IN THE HWO OR SFP.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 443 AM EDT THU JUN 13 2013
FRI...HI PRES IS FCST TO BE CENTERED OVER THE E HALF OF LK SUP ON
FRI AFTN TO THE E OF UPR RDG AXIS EXTENDING FM THE CENTRAL PLAINS
THRU THE UPR MS RIVER VALLEY AND INTO SCENTRAL CANADA DOWNSTREAM OF
CLOSED LO OVER THE CANADIAN ROCKIES JUST N OF THE BORDER. ALTHOUGH
SOME HI CLDS IN THE DVLPG SLY FLOW/WAD PATTERN BTWN THE HI AND LOWER
PRES TO THE W MAY DRIFT INTO THE WRN COUNTIES IN THE AFTN...THE DAY
SHOULD FEATURE A GOOD DEAL OF SUNSHINE WITH LLVL DRY AIRMASS IN
PLACE. H85 TEMPS FCST IN THE 11-12C RANGE AND MIXING TO H8 ON FCST
SDNGS YIELDS HI TEMPS WELL INTO THE 70S OVER THE INTERIOR W HALF
AWAY FM LK MODERATION. THE DEEP MIXING AND DRY AIRMASS IN PLACE WL
CAUSE SFC DEWPTS TO FALL INTO THE 20S IN THE AFTN OVER THE
INTERIOR...WITH MIN RH AS LO AS 20 PCT OVER THE E CLOSER TO THE CORE
OF DRIEST AIR. FORTUNATELY...WINDS WL BE LGT...SO FIRE WX CONCERNS
SHOULD BE MINIMAL.
FOCUS FOR FRI NGT THRU THE WEEKEND WL THEN SHIFT TO PCPN CHCS
ASSOCIATED WITH BROAD SW FLOW BTWN HI PRES RETREATING INTO THE MID
ATLANTIC STATES AND CLOSED LO THAT DRIFTS ONLY SLOWLY E ACRS SRN
CANADA AND TOWARD THE UPR LKS BY LATE SUN. GUIDANCE IN GOOD
AGREEMENT SHOWING SOME DEEP LYR ISENTROPIC ASCENT DVLPG ON FRI NGT
WITH BAND OF HIER MID LVL RH MOVING IN FM THE W. BUT GIVEN THE
DRYNESS OF THE ANTECENT AIRMASS...TENDENCY FOR MOST IMPRESSIVE DEEP
LYR QVECTOR CNGVC TO REMAIN WELL TO THE NW CLOSER TO THE LO ALLOWING
A MORE PERSISTENT UPR RDG AXIS OVER THE UPR LKS...AND PRESENCE OF
WARM FNT IN IOWA/ILLINOIS THAT WL INTERCEPT THE BULK OF RETURNING
LLVL MSTR...TRIMMED BACK THE EWD ADVANCE OF THE FRI NGT POPS SHOWN
IN PREVIOUS FCST TO MORE ALIGN WITH 00Z NAM/GFS/CNDN FCSTS. MIN
TEMPS ON FRI NGT SHOULD BE COOLEST OVER THE E CLOSER TO RETREATING
HI PRES RDG/DRIER AIR.
SAT/SAT NGT...NOT SURPRISINGLY...SGNFT MODEL DIFFERENCES BEGIN TO
SHOW UP IN THIS TIME PERIOD. THERE IS GOOD AGREEMENT ON PROGRESSION
OF BAND OF HIER MID LVL RH ALIGNED WITH DEEP ISENTROPIC ASCENT AND
AHEAD OF SHRTWV MOVING E THRU SW ONTARIO WELL IN ADVANCE OF SLOWER
CLOSED LO IN SASKATCHEWAN. THIS BAND OF HIER RH IS FCST TO DRIFT E
ACRS UPR MI FOLLOWED BY MID LVL DRYING IN THE JET SURGE REGION ON
THE SRN FLANK OF THE SHRTWV MOVING THRU SW ONTARIO. THE 00Z GFS IS
THEN MOST AGGRESSIVE AT DVLPG MORE SHRA/TS OVER THE W IN THE AFTN
WITH SHRTWV INTERACTING WITH THE GREATER INSTABILITY ALLOWED BY CLRG
IN THE WAKE OF THE DEPARTING MSTR AXIS. THE GFS THEN MOVES THESE
SHRA/TS E ACRS THE CWA ON SAT NGT. THE 00Z NAM ON THE OTHER HAND IS
VERY AGGRESSIVE WITH THE MID LVL JET SURGE DRYING...WITH FCST SDNGS
SHOWING EFFECTIVE MID LVL CAPPING AND ALMOST NO PCPN. PREFER THE
COMPROMISE 00Z CNDN MODEL HANDLING OF THE POPS GIVEN BETTER
PLACEMENT OF THE FEATURES RELATIVE TO CLOSED LO LINGERING BACK W OF
LK WINNIPEG THRU 12Z SUN...WITH LESS AGGRESSIVE MID LVL DRYING THAN
THE NAM AND LESS DYNAMIC SUPPORT FOR INSTABILITY SHRA/TS OVER THE W
THAN SHOWN BY THE GFS LATE SAT AFTN/NGT. BUT PASSAGE OF THIS WEAKER
SHRTWV STILL WARRANTS CHC POPS ON SAT NGT AS INDICATED BY THE CNDN
MODEL.
SUN...THERE IS A GENERAL MODEL CONSENSUS SHRTWV RDG BTWN DEPARTING
WEAK SHRTWV TO THE E AND SLOWLY APRCHG CLOSED LO FCST TO OPEN AND
APRCH NW MN LATE IN THE DAY WL BE AN INFLUENCE ON UPR MI WX. THE
RESULT SHOULD BE MAINLY DRY WX OVER THE CWA ON SUN. SO LOWERED MODEL
CONSENSUS POPS A BIT TO REFLECT THE MID LVL DRYING FCST/LACK OF
DYNAMIC SUPPORT...WHICH IS FCST TO ARRIVE ONLY LATER IN THE DAY OVER
THE W CLOSER TO APRCHG SHRTWV.
SUN NGT/MON... BEST CHC FOR SHRA/SOME TS LOOKS TO BE ON SUN NGT INTO
MON WHEN DPVA/FAIRLY VIGOROUS DEEP LYR QVECTOR CNVGC/HGT FALLS
ASSOCIATED WITH APRCHG SHRTWV FM THE WNW IMPACT THE CWA. MODEL
CONSENSUS HI CHC POPS APPEAR ON THE RIGHT TRACK.
EXTENDED...A DRIER NW FLOW ALF IN THE WAKE OF DEPARTING SHRTWV
SHOULD BRING MAINLY DRY WX TO THE UPR LKS ON TUE AND WED. ONLY
POTENTIAL FLY IN THE OINTMENT WOULD BE A STRONGER SHRTWV EMBEDDED IN
THIS FLOW...WHICH COMMONLY BRING SOME SHRA/TS TO THE AREA IN THE
SUMMER IF THERE IS ENUF MSTR/INSTABILITY. BUT NOTHING HIER THAN SCHC
POPS ARE WARRANTED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 119 PM EDT THU JUN 13 2013
HIGH PRESSURE SINKING SOUTHWARD OUT OF ONTARIO WILL GRADUALLY REACH
THE GREAT LAKES LATE THIS AFTERNOON. DRY AIR HAS ALREADY BE OBSERVED
SCOURING OUT LOW CLOUDS OVER LAKE SUPERIOR. EXPECT THE SET OF MVFR
CLOUDS OVER CMX TO DISSIPATE WITHIN THE NEXT COUPLE HOURS. KSAW WILL
TAKE THE LONGEST TO CLEAR OUT...BUT SHOULD BE SKC BY 00Z TONIGHT.
GUSTY WINDS WILL ALSO DIE DOWN LATE THIS AFTERNOON AS THE LOW
PRESSURE SYSTEM TO THE SOUTHEAST MOVES TO THE EAST COAST...ALLOWING
THE PRESSURE GRADIENT TO RELAX. A QUIET DAY IS IN STORE TOMORROW AS
HIGH PRESSURE WILL BE DIRECTLY OVERHEAD...KEEPING CONDITIONS
DRY...SKIES MOSTLY CLEAR...AND WINDS LIGHT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 443 AM EDT THU JUN 13 2013
N WINDS UP TO 15-25 KTS TODAY...HIGHEST OVER THE E PART OF THE
LAKE...UNDER A SHARPER PRES GRADIENT ON THE SOUTHERN FLANK OF
BUILDING HI PRES IN ONTARIO WILL DIMINISH TONIGHT AS THE HI MOVES
TOWARD THE AREA AND THE GRADIENT SLACKENS. THEN A RELATIVELY WEAK
PRES GRADIENT AND HI OVERWATER STABILITY WILL CAUSE WINDS UNDER 15
KTS INTO EARLY NEXT WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...KC
AVIATION...MCD
MARINE...KC
AREA FORECAST DISCUSSION
NWS GAYLORD MI
103 PM EDT THU JUN 13 2013
.SYNOPSIS...
ISSUED AT 351 AM EDT THU JUN 13 2013
COOLER AND LESS HUMID WEATHER HAS ITS SIGHTS SET ON NORTHERN
MICHIGAN AS WE WRAP UP THE WORK WEEK...AS CANADIAN HIGH PRESSURE
BUILDS FROM THE NORTHERN PLAINS THROUGH THE GREAT LAKES. THERE IS
AN OUTSIDE CHANCE OF A SHOWER IN SPOTS TODAY...BEFORE DRY WEATHER
RETURNS TONIGHT THROUGH SATURDAY MORNING. A COUPLE MORE SHOWERS OR
EVEN A RUMBLE OF THUNDER ARE POSSIBLE LATER SATURDAY...WITH A FEW
MORE CHANCES FOR RAIN EARLY NEXT WEEK. THAT WON`T LAST TOO LONG
THOUGH...AS HIGH PRESSURE AGAIN RETURNS WITH SEASONABLE BUT DRY
WEATHER TOWARD MIDWEEK OF NEXT WEEK.
&&
.UPDATE...
ISSUED AT 1255 PM EDT THU JUN 13 2013
CLOUDS ARE INCREASING ACROSS THE FORECAST AREA, WITH A CU FIELD IN
NE LOWER, A STRATUS DECK IN NW LOWER AND WHAT LOOKS TO BE A SC
DECK IN E UPPER. UPSTREAM, IN LAKE SUPERIOR, AND NORTH, THE CLOUDS
ARE BEGINNING TO MIX OUT ALONG THE EDGE, WHICH IS GOING ALONG WITH
THE MODEL IDEA. SO UPPED THE AMOUNT OF CLOUDS IN N LOWER AS THE CU
FIELD INCREASES. IN E UPPER THE CLOUD MASS SHOULD START TO
DIMINISH OVER THE NEXT COUPLE OF HOURS AS THE DRY AIR WORKS INTO
THE REGION. RUC ANALYSIS SHOWS THAT THE 500 MB TROUGH AXIS IS
ABOUT THROUGH, SO THAT THE SUBSIDENCE WILL ADD TO THE DRYING.
OTHERWISE, THE REST OF THE FORECAST LOOKS GOOD.
UPDATE ISSUED AT 1000 AM EDT THU JUN 13 2013
STRATUS CLOUDS IN C AND E UPPER THIS MORNING ARE BEGINNING TO MIX
OUT, AS THE STRATUS IS EXPECTED TO TRANSITION TO CU OR SC. THIS
SAME POOL OF MOISTURE HAS MADE IT INTO NW LOWER WITH STRATUS
BEGINNING TO SPREAD ALONG THE LAKE MICHIGAN SHORE FROM NEAR CVX TO
FKS. THIS TOO IS EXPECTED TO THIN AND TRANSITION TO CU. MAIN
CONCERN IS THE CLOUD MASS IN ONTARIO NORTH OF ANJ. MODELS HAVE
BEEN ADVERTISING LIGHT RAIN, IN NE LOWER. THIS SEEMS GOOD WITH
DRIZZLE BEING REPORTED IN CYLD. THIS CLOUD MASS IS ASSOCIATED WITH
THE 500 MB SHORTWAVE TROUGH DROPPING DOWN THROUGH THE FORECAST
AREA THIS MORNING. BY THE AFTERNOON, THE SHORTWAVE WILL BE THROUGH
THE FORECAST AREA AND THE MOISTURE EXPECTED TO CONTINUE TO MIX
OUT.
UPDATE ISSUED AT 640 AM EDT THU JUN 13 2013
HIGH CLOUDS THINNING OUT QUICKLY ACROSS THE REGION LEAVING PARTLY
TO MOSTLY SUNNY SKIES TO START THE DAY. BUT...LOW CLOUDS (STRATUS)
STARTING TO EXPAND ACROSS THE U.P. AHEAD OF UPSTREAM SHORT WAVE.
MODEL RH FORECASTS SUGGEST LOWER CLOUDS MAY CONTINUE TO EXPAND
DOWN ACROSS A GOOD PORTION OF THE CWA OVER THE NEXT SEVERAL
HOURS...ALTHOUGH THAT MAY BE OFFSET BY HEATING/MIXING. HAVE
TWEAKED SKY FORECASTS TO REFLECT SUNNIER START TO THE DAY THEN
TRENDING CLOUDIER LATE MORNING INTO THE AFTERNOON.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 351 AM EDT THU JUN 13 2013
MCS/SEVERE WEATHER ONGOING ACROSS THE LOWER GREAT LAKES/OHIO VALLEY
THIS MORNING...SPURRED ON BY MID LEVEL SHORT WAVE ADVANCING THROUGH
THE REGION. NRN EDGE OF MCS RAIN SHIELD JUST SKIRTING THE SRN TIER
OF COUNTIES...PRETTY MUCH AS EXPECTED. TO THE NORTH...ANOTHER SHORT
WAVE NOTED OVER ONTARIO DROPPING S/SE TOWARD THE STATE. SPOTTY
SHOWER ACTIVITY NOTED WITH THIS FEATURE.
TODAY...SHORT WAVE TO THE NORTH WILL ROTATE DOWN THROUGH THE REGION
BRINGING VARYING CLOUD COVER. LOWER HEIGHTS/COOLER TEMPS ALOFT AND
DAYTIME HEATING BRINGS SOME POTENTIAL FOR AFTERNOON INSTABILITY AND
A FEW SHOWERS TO DEVELOP PER INHERITED FORECAST. UNMODIFIED FORECAST
SOUNDINGS DOES REVEAL ONE TO TWO HUNDRED J/KG OF CAPE THIS
AFTERNOON. HOWEVER...MODEL SFC DEWPOINTS LOOK A BIT OVERDONE.
MODIFIED FORECAST SOUNDINGS USING MOS GUIDANCE DEWPOINTS AROUND 50F
REDUCES MLCAPE VALUES TO NEARLY NOTHING THIS AFTERNOON. THUS...VERY
TEMPTED TO PULL POPS. BUT...GIVEN THAT THERE ARE SHOWERS UPSTREAM
WITH THE WAVE CURRENTLY...AND ALL GUIDANCE PRODUCES SOME LIGHT
PRECIP...WILL KEEP CHANCY POPS INTACT.
TONIGHT...SHORT WAVE EXITS OFF TO THE SOUTHEAST BY EVENING WITH
DRIER AIR/CLEARING SKIES TAKING SHAPE ACROSS NRN MICHIGAN. MAY GET
RATHER COOL...BUT WE DO KEEP A BIT OF A PRESSURE GRADIENT ACROSS THE
REGION THROUGH THE NIGHT AND PERHAPS A LIGHT NORTHERLY WIND. HAVE
NUDGED FORECAST LOW TEMPS UPWARD A COUPLE DEGREES...UPPER 30S TO
MIDDLE 40S. COLDER NIGHT LOOKS TO BE FRIDAY NIGHT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 351 AM EDT THU JUN 13 2013
LIKE COOLER TEMPS AND LOW HUMIDITY? WE GOT THAT COVERED! ALSO LIKE
WARMER AND A BIT MORE HUMID (I.E. MORE JUNE-LIKE) WEATHER? WE ALSO
HAVE THAT COVERED OVER THE NEXT 7 DAYS...WITH A RATHER CHANGEABLE
PERIOD OF WEATHER SET TO CONTINUE ACROSS THE NORTHWOODS AS WE ROLL
THROUGH MID MONTH. THIS IS NOT UNLIKE THE PAST MONTH OR SO...WHICH
HAS SEEN SIMILAR UP AND DOWN WEATHER ACROSS THE REGION...WITH THE
CULPRIT THIS TIME BEING A RATHER STABLE 4-WAVE HEMISPHERIC SETUP
FEATURING ANCHOR TROUGHING NEAR THE BERING SEA/NORTH PACIFIC AND
ALSO INTO EASTERN CANADA. THIS SETUP CONTINUES TO PLACE NORTHERN
MICHIGAN IN THE PRECARIOUS POSITION OF BEING NEAR BOTH UPPER RIDGING
(BUILDING THROUGH THE PLAINS/MIDWEST) AND UPPER TROUGHING (BUILDING
THROUGH CANADA)...HENCE THE BIG SWINGS WE HAVE SEEN FROM TIME TO
TIME THE PAST 3-4 WEEKS.
NOT MUCH CHANGE IS FORESEEN OVER THE NEXT 7-10 DAYS...AS INITIAL
UPPER TROUGHING INTO LATE WEEK IS BRIEFLY REPLACED BY BUILDING MID
LEVEL RIDGING INTO THE WEEKEND. THAT SETUP WILL BE SHORT-LIVED...
AS HEIGHTS BEGIN TO FALL THROUGH EARLY NEXT WEEK AS RENEWED
TROUGHING OFF THE PACIFIC NORTHWEST COAST HELPS PUMP SUMMERTIME
RIDGING ACROSS THE ROCKIES WHILE ALSO ALLOWING DOWNSTREAM HEIGHTS TO
FALL THROUGH CENTRAL AND EASTERN CANADA...AND EVENTUALLY THE GREAT
LAKES TOWARD TUESDAY AND WEDNESDAY.
IN THE MEANTIME...REALLY NO WEATHER OF NOTE FRIDAY INTO THE FIRST
HALF OF SATURDAY...AS LOW LEVEL RIDGING SLIDES FROM THE UPPER
MIDWEST TO A POSITION OVERHEAD BY FRIDAY NIGHT. THAT SETUP WILL
DELIVER COOLER AND MUCH LESS HUMID CONDITIONS...WITH VERY LITTLE IN
THE WAY OF ANY CLOUDS (MAYBE A LITTLE CU FRIDAY AFTERNOON?). LOWS
FRIDAY NIGHT CONTINUE TO LOOK CHILLY...WITH READINGS WELL INTO THE
40S EVERYWHERE...AND LIKELY WELL INTO THE 30S FOR INLAND AREAS AS
FRIDAY AFTERNOON DIURNAL MIXING KICKS DEW POINTS DOWN INTO THE
28-34F RANGE. NOT OUT OF THE QUESTION WE COULD SEE SOME FROST FOR
THE USUAL COLD SPOTS...BUT THIS SHOULD BE MORE THE EXCEPTION THAN
THE RULE...SO NO HWO MENTION JUST YET.
CLOUDS LOOK TO THICKEN ON SATURDAY AS MID LEVEL WARM ADVECTION
ASCENT KICKS INTO GEAR OVER THE WESTERN LAKES. AN AXIS OF MUCH
STEEPER MID LEVEL LAPSE RATES IS ALSO PROGGED TO WORK THROUGH THE
WESTERN LAKES ROUGHLY 18-00Z...SUPPORTING THE NOTION OF SOME
ELEVATED CONVECTION (EFFECTIVE CAPE VALUES PERHAPS UP TO 300 J/KG)
PERHAPS TRYING TO WORK THROUGH THE REGION...MAINLY AFTER 21Z.
HOWEVER...RATHER DRY SUB-700MB LAYER AND BEST LOW LEVEL JET
FORCING/THETA-E RIDGING POINTING TOWARD SOUTHERN LAKE MICHIGAN
SUGGESTS THAT NOTHING MUCH MORE THAN SOME SPRINKLES/LIGHT SHOWERS
MAY ACTUALLY SURVIVE ACROSS THE AREA THROUGH THE EVENING.
COULD SEE A FEW LINGERING SHOWERS INTO SUNDAY AS A WEAK UPPER
TROUGH/BETTER MOISTURE AXIS SLIPS THROUGH THE REGION...BUT
CONFIDENCE IN ANY WIDESPREAD COVERAGE IS VERY LOW...AND HONESTLY CAN
FORESEE MUCH OF THE DAY (IF NOT ALL OF IT) BEING DRY. ALSO STARTING
TO GET THE FEELING THAT THE REMAINDER OF THE FORECAST PERIOD WILL BE
DRY...THOUGH CAN`T RULE OUT A FEW MORE SHOWERS LATER MONDAY/MONDAY
NIGHT AS OUR NEXT UPPER TROUGH SWINGS THROUGH. AFTER THAT...BACK TO
DRY AND LESS HUMID WEATHER TUESDAY INTO WEDNESDAY (MAYBE NEXT
THURSDAY TOO) AS LOW LEVEL RIDGING ONCE AGAIN BUILDS FROM CENTRAL
CANADA DOWN INTO THE NORTHERN LAKES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 640 AM EDT THU JUN 13 2013
VFR CONDITIONS TO START THE DAY AT THE TERMINAL SITES. HOWEVER...LOWER
CLOUDS MAY EXPAND ACROSS THE REGION LATER THIS MORNING AND THE
AFTERNOON AS ANOTHER WAVE AND DEEPER MOISTURE ROTATE DOWN INTO THE
REGION. THERE IS THE POSSIBILITY FOR A PERIOD OF MVFR CIGS LATE
MORNING THROUGH THE AFTERNOON...BUT HAVE ONLY INCLUDED SCT MVFR
CLOUDS FOR THE MOMENT. IN ADDITION...GUSTY NORTHERLY WINDS WILL BE
FELT AT THE TERMINAL SITES WITH GUSTS INTO THE LOWER 20 KNOT RANGE
EXPECTED.
SKIES CLEAR OUT TONIGHT AND WINDS DIMINISH...WITH VFR CONDITIONS
DOMINATING.
&&
.MARINE...
ISSUED AT 351 AM EDT THU JUN 13 2013
GUSTY NORTHERLY WINDS DEVELOP ON THE LAKES TODAY...AND HIGH
PRESSURE BUILDS OUT OF CANADA INTO THE GREAT LAKES. WIND GUSTS UP
TO 20 KNOTS AND 2 TO 4 FOOT WAVES ANTICIPATED...JUST SHY OF SMALL
CRAFT ADVISORY CRITERIA. WINDS DIMINISH TONIGHT AND REMAIN ON THE
LIGHTER SIDE THROUGH FRIDAY.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...JL
SYNOPSIS...DL
SHORT TERM...BA
LONG TERM...DL
AVIATION...BA
MARINE...BA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
712 AM EDT THU JUN 13 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 443 AM EDT THU JUN 13 2013
LOTS OF STRONG TSRA AND LIGHTNING OVER THE LOWER GREAT LAKES AND
OHIO VALLEY THIS MORNING AHEAD OF STRONGER SHORTWAVE TROUGH AND SFC
LOW/WARM FRONT CROSSING THAT AREA. CLOSER TO HOME...WV LOOP
INDICATES NORTHERN BRANCH TROUGHING CLOSE BY OVER ONTARIO INTO
QUEBEC. MAIN WAVE WITHIN THAT TROUGH IS SLIDING SOUTH OF JAMES BAY
BUT ASSOCIATED LOW-LEVEL TROUGH AXIS IS JUST TO NORTH OF LK SUPERIOR
AS OF 05Z. AS THE SHORTWAVE MOVES INTO QUEBEC EXPECT THE SFC-H85
TROUGH TO DROP ACROSS UPR LAKES THIS MORNING. SFC TEMPS IMMEDIATELY
IN WAKE OF TROUGH IN ONTARIO NOT TOO DIFFERENT THAN CURRENT READINGS
OVER UPR MICHIGAN. COOLING AT 925-850MB IS SEEN THOUGH WITH H85
TEMPS DOWN TO +8C AT CWPL WHILE READINGS AT MPX/GRB AND APX WERE
AROUND +13C. SIMILAR COOLING AT 925MB WITH +20C AT APX FALLING OFF
TO +10C AT CWPL AND +13C AT CWZC /MOOSONEE ONTARIO AT SOUTH SHORE OF
JAMES BAY/. AT 00Z...ONLY UPSTREAM SOUNDING THAT SHOWED LOW-LEVEL
MOISTURE WAS CWZC AND NIGHTTIME SATELLITE IMAGERY AND AVAILABLE OBS
IN ONTARIO ARE SHOWING SOME SCT-BKN MVFR CLOUDS THUS FAR...THOUGH
07Z IMAGERY INDICATES LOW CLOUDS MAY BE STARTING TO FORM OVR HURON
MOUNTAINS. MODELS COMPARED WELL TO EACH OTHER INITIALIZING SFC
THROUGH H5 FEATURES UPSTREAM. NAM INITIALIZED SOUNDINGS AT CWPL AND
CWZC WELL. WILL LEAN ON THE NAM AND RUC13 FOR LOW-LEVEL MOISTURE
FORECASTS FOR TODAY OVR CWA.
FROM A FORECAST STANDPOINT...ENCOURAGED TO SEE LOWER CLOUDS
STARTING TO FORM. THINK IDEA OF BKN LOW CLOUDS THIS MORNING STILL
ON TRACK...ESPECIALLY FOR UPSLOPE AREAS OF NCNTRL UPR MICHIGAN. HAVE
STRUGGLED ON WHAT TO DO WITH DRIZZLE CHANCES. WAS GOING TO PULL
MENTION BASED ON RUC SOUNDINGS WHICH SHOWED LINGERING DRYING BENEATH
HIGHER MOISTURE 950-900MB. ULTIMATELY DECIDED TO KEEP MENTION IN FOR
HIGHER TERRAIN OF MARQUETTE COUNTY AS T/TD DEPRESSION AT STDM4
HAS STEADILY NARROWED OVER THE LAST FEW HOURS. THINK THIS MOISTENING
COMBINED WITH UPSLOPE FLOW COULD STILL RESULT IN LGT DRIZZLE OR
SPRINKLES. DRIZZLE WILL ONLY BE AROUND FOR THE MORNING. ONCE CLOUDS
SET UP...THINK THEY MAY STUBBORN TO LEAVE AS THERMAL TROUGHING FM
925-850MB PERSISTS ALONG WITH A CYCLONIC CONVERGENT NNE FLOW
925-850MB. KEPT BKN CLOUDS IN THROUGH EARLY AFTN WITH SCT CLOUDS
CLOUDS STAYING AROUND THROUGH MID AFTN IN THOSE UPSLOPE AREAS.
EVEN AWAY FM FAVORED AREAS NEAR LK SUPERIOR...THERMAL TROUGHING AND
DAYTIME HEATING SHOULD ACT TO INCREASE CU FOR A WHILE BEFORE
CLOUDS SCATTER OUT LATE TODAY. EXPECT RAPID CLEARING OF SKIES
LATE THIS AFTN/EARLY THIS EVENING AS SHARP 925-850MB DRYING WITH
DWPNT DEPRESSIONS OVER 15C SURGES INTO THE REGION FROM ONTARIO.
ONE ITEM TO NOTE ABOUT TODAY. A MODERATE SWIM RISK IS IN PLACE FOR
SHORELINES OF MARQUETTE AND ALGER COUNTIES AS WAVES BUILD TO 2 TO 4
FEET. LOWERING WAVES WILL LESSEN THE SWIM RISK BY THIS EVENING.
FOR TONIGHT...A COOL NIGHT IN STORE DUE TO THE CLEARING SKIES AND
LIGHT WINDS AS HIGH PRESSURE RIDGE CURRENTLY OVER MANITOBA DROPS
ACROSS REGION. WINDS FCST TO BECOME CALM OVER INTERIOR WEST CWA
WHICH WILL RESULT IN TEMPS FALLING INTO THE UPR 30S...MAYBE EVEN MID
30S. CURRENT READINGS BENEATH THE HIGH IN MANITOBA HAVE ALREADY INTO
UPR 30S AS OF 07Z. KEPT THE FROST MENTION FOR INTERIOR WEST...BUT IT
REMAINS TOO ISOLD TO MENTION IN THE HWO OR SFP.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 443 AM EDT THU JUN 13 2013
FRI...HI PRES IS FCST TO BE CENTERED OVER THE E HALF OF LK SUP ON
FRI AFTN TO THE E OF UPR RDG AXIS EXTENDING FM THE CENTRAL PLAINS
THRU THE UPR MS RIVER VALLEY AND INTO SCENTRAL CANADA DOWNSTREAM OF
CLOSED LO OVER THE CANADIAN ROCKIES JUST N OF THE BORDER. ALTHOUGH
SOME HI CLDS IN THE DVLPG SLY FLOW/WAD PATTERN BTWN THE HI AND LOWER
PRES TO THE W MAY DRIFT INTO THE WRN COUNTIES IN THE AFTN...THE DAY
SHOULD FEATURE A GOOD DEAL OF SUNSHINE WITH LLVL DRY AIRMASS IN
PLACE. H85 TEMPS FCST IN THE 11-12C RANGE AND MIXING TO H8 ON FCST
SDNGS YIELDS HI TEMPS WELL INTO THE 70S OVER THE INTERIOR W HALF
AWAY FM LK MODERATION. THE DEEP MIXING AND DRY AIRMASS IN PLACE WL
CAUSE SFC DEWPTS TO FALL INTO THE 20S IN THE AFTN OVER THE
INTERIOR...WITH MIN RH AS LO AS 20 PCT OVER THE E CLOSER TO THE CORE
OF DRIEST AIR. FORTUNATELY...WINDS WL BE LGT...SO FIRE WX CONCERNS
SHOULD BE MINIMAL.
FOCUS FOR FRI NGT THRU THE WEEKEND WL THEN SHIFT TO PCPN CHCS
ASSOCIATED WITH BROAD SW FLOW BTWN HI PRES RETREATING INTO THE MID
ATLANTIC STATES AND CLOSED LO THAT DRIFTS ONLY SLOWLY E ACRS SRN
CANADA AND TOWARD THE UPR LKS BY LATE SUN. GUIDANCE IN GOOD
AGREEMENT SHOWING SOME DEEP LYR ISENTROPIC ASCENT DVLPG ON FRI NGT
WITH BAND OF HIER MID LVL RH MOVING IN FM THE W. BUT GIVEN THE
DRYNESS OF THE ANTECENT AIRMASS...TENDENCY FOR MOST IMPRESSIVE DEEP
LYR QVECTOR CNGVC TO REMAIN WELL TO THE NW CLOSER TO THE LO ALLOWING
A MORE PERSISTENT UPR RDG AXIS OVER THE UPR LKS...AND PRESENCE OF
WARM FNT IN IOWA/ILLINOIS THAT WL INTERCEPT THE BULK OF RETURNING
LLVL MSTR...TRIMMED BACK THE EWD ADVANCE OF THE FRI NGT POPS SHOWN
IN PREVIOUS FCST TO MORE ALIGN WITH 00Z NAM/GFS/CNDN FCSTS. MIN
TEMPS ON FRI NGT SHOULD BE COOLEST OVER THE E CLOSER TO RETREATING
HI PRES RDG/DRIER AIR.
SAT/SAT NGT...NOT SURPRISINGLY...SGNFT MODEL DIFFERENCES BEGIN TO
SHOW UP IN THIS TIME PERIOD. THERE IS GOOD AGREEMENT ON PROGRESSION
OF BAND OF HIER MID LVL RH ALIGNED WITH DEEP ISENTROPIC ASCENT AND
AHEAD OF SHRTWV MOVING E THRU SW ONTARIO WELL IN ADVANCE OF SLOWER
CLOSED LO IN SASKATCHEWAN. THIS BAND OF HIER RH IS FCST TO DRIFT E
ACRS UPR MI FOLLOWED BY MID LVL DRYING IN THE JET SURGE REGION ON
THE SRN FLANK OF THE SHRTWV MOVING THRU SW ONTARIO. THE 00Z GFS IS
THEN MOST AGGRESSIVE AT DVLPG MORE SHRA/TS OVER THE W IN THE AFTN
WITH SHRTWV INTERACTING WITH THE GREATER INSTABILITY ALLOWED BY CLRG
IN THE WAKE OF THE DEPARTING MSTR AXIS. THE GFS THEN MOVES THESE
SHRA/TS E ACRS THE CWA ON SAT NGT. THE 00Z NAM ON THE OTHER HAND IS
VERY AGGRESSIVE WITH THE MID LVL JET SURGE DRYING...WITH FCST SDNGS
SHOWING EFFECTIVE MID LVL CAPPING AND ALMOST NO PCPN. PREFER THE
COMPROMISE 00Z CNDN MODEL HANDLING OF THE POPS GIVEN BETTER
PLACEMENT OF THE FEATURES RELATIVE TO CLOSED LO LINGERING BACK W OF
LK WINNIPEG THRU 12Z SUN...WITH LESS AGGRESSIVE MID LVL DRYING THAN
THE NAM AND LESS DYNAMIC SUPPORT FOR INSTABILITY SHRA/TS OVER THE W
THAN SHOWN BY THE GFS LATE SAT AFTN/NGT. BUT PASSAGE OF THIS WEAKER
SHRTWV STILL WARRANTS CHC POPS ON SAT NGT AS INDICATED BY THE CNDN
MODEL.
SUN...THERE IS A GENERAL MODEL CONSENSUS SHRTWV RDG BTWN DEPARTING
WEAK SHRTWV TO THE E AND SLOWLY APRCHG CLOSED LO FCST TO OPEN AND
APRCH NW MN LATE IN THE DAY WL BE AN INFLUENCE ON UPR MI WX. THE
RESULT SHOULD BE MAINLY DRY WX OVER THE CWA ON SUN. SO LOWERED MODEL
CONSENSUS POPS A BIT TO REFLECT THE MID LVL DRYING FCST/LACK OF
DYNAMIC SUPPORT...WHICH IS FCST TO ARRIVE ONLY LATER IN THE DAY OVER
THE W CLOSER TO APRCHG SHRTWV.
SUN NGT/MON... BEST CHC FOR SHRA/SOME TS LOOKS TO BE ON SUN NGT INTO
MON WHEN DPVA/FAIRLY VIGOROUS DEEP LYR QVECTOR CNVGC/HGT FALLS
ASSOCIATED WITH APRCHG SHRTWV FM THE WNW IMPACT THE CWA. MODEL
CONSENSUS HI CHC POPS APPEAR ON THE RIGHT TRACK.
EXTENDED...A DRIER NW FLOW ALF IN THE WAKE OF DEPARTING SHRTWV
SHOULD BRING MAINLY DRY WX TO THE UPR LKS ON TUE AND WED. ONLY
POTENTIAL FLY IN THE OINTMENT WOULD BE A STRONGER SHRTWV EMBEDDED IN
THIS FLOW...WHICH COMMONLY BRING SOME SHRA/TS TO THE AREA IN THE
SUMMER IF THERE IS ENUF MSTR/INSTABILITY. BUT NOTHING HIER THAN SCHC
POPS ARE WARRANTED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 708 AM EDT THU JUN 13 2013
NRLY WINDS ARE INCREASING BEHIND COLD FRONT MOVING THROUGH THE AREA.
BEST CHANCE FOR LOWER MVFR OR EVEN IFR CONDITIONS IS AT KSAW DUE TO
UPSLOPE FLOW AND INCREASED LOW LEVEL MOISTURE. ALSO HAVE INCLUDED
BKN LOWER CLOUDS AT IWD THROUGH MID MORNING BASED ON RECENT TRENDS.
IMPROVING CONDITIONS ALL SITES THIS AFTERNOON AND TONIGHT AS HIGH
PRESSURE AND DRY AIR BUILD ACROSS UPPER MICHIGAN.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 443 AM EDT THU JUN 13 2013
N WINDS UP TO 15-25 KTS TODAY...HIGHEST OVER THE E PART OF THE
LAKE...UNDER A SHARPER PRES GRADIENT ON THE SOUTHERN FLANK OF
BUILDING HI PRES IN ONTARIO WILL DIMINISH TONIGHT AS THE HI MOVES
TOWARD THE AREA AND THE GRADIENT SLACKENS. THEN A RELATIVELY WEAK
PRES GRADIENT AND HI OVERWATER STABILITY WILL CAUSE WINDS UNDER 15
KTS INTO EARLY NEXT WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...KC
AVIATION...JLA
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
446 AM EDT THU JUN 13 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 443 AM EDT THU JUN 13 2013
LOTS OF STRONG TSRA AND LIGHTNING OVER THE LOWER GREAT LAKES AND
OHIO VALLEY THIS MORNING AHEAD OF STRONGER SHORTWAVE TROUGH AND SFC
LOW/WARM FRONT CROSSING THAT AREA. CLOSER TO HOME...WV LOOP
INDICATES NORTHERN BRANCH TROUGHING CLOSE BY OVER ONTARIO INTO
QUEBEC. MAIN WAVE WITHIN THAT TROUGH IS SLIDING SOUTH OF JAMES BAY
BUT ASSOCIATED LOW-LEVEL TROUGH AXIS IS JUST TO NORTH OF LK SUPERIOR
AS OF 05Z. AS THE SHORTWAVE MOVES INTO QUEBEC EXPECT THE SFC-H85
TROUGH TO DROP ACROSS UPR LAKES THIS MORNING. SFC TEMPS IMMEDIATELY
IN WAKE OF TROUGH IN ONTARIO NOT TOO DIFFERENT THAN CURRENT READINGS
OVER UPR MICHIGAN. COOLING AT 925-850MB IS SEEN THOUGH WITH H85
TEMPS DOWN TO +8C AT CWPL WHILE READINGS AT MPX/GRB AND APX WERE
AROUND +13C. SIMILAR COOLING AT 925MB WITH +20C AT APX FALLING OFF
TO +10C AT CWPL AND +13C AT CWZC /MOOSONEE ONTARIO AT SOUTH SHORE OF
JAMES BAY/. AT 00Z...ONLY UPSTREAM SOUNDING THAT SHOWED LOW-LEVEL
MOISTURE WAS CWZC AND NIGHTTIME SATELLITE IMAGERY AND AVAILABLE OBS
IN ONTARIO ARE SHOWING SOME SCT-BKN MVFR CLOUDS THUS FAR...THOUGH
07Z IMAGERY INDICATES LOW CLOUDS MAY BE STARTING TO FORM OVR HURON
MOUNTAINS. MODELS COMPARED WELL TO EACH OTHER INITIALIZING SFC
THROUGH H5 FEATURES UPSTREAM. NAM INITIALIZED SOUNDINGS AT CWPL AND
CWZC WELL. WILL LEAN ON THE NAM AND RUC13 FOR LOW-LEVEL MOISTURE
FORECASTS FOR TODAY OVR CWA.
FROM A FORECAST STANDPOINT...ENCOURAGED TO SEE LOWER CLOUDS
STARTING TO FORM. THINK IDEA OF BKN LOW CLOUDS THIS MORNING STILL
ON TRACK...ESPECIALLY FOR UPSLOPE AREAS OF NCNTRL UPR MICHIGAN. HAVE
STRUGGLED ON WHAT TO DO WITH DRIZZLE CHANCES. WAS GOING TO PULL
MENTION BASED ON RUC SOUNDINGS WHICH SHOWED LINGERING DRYING BENEATH
HIGHER MOISTURE 950-900MB. ULTIMATELY DECIDED TO KEEP MENTION IN FOR
HIGHER TERRAIN OF MARQUETTE COUNTY AS T/TD DEPRESSION AT STDM4
HAS STEADILY NARROWED OVER THE LAST FEW HOURS. THINK THIS MOISTENING
COMBINED WITH UPSLOPE FLOW COULD STILL RESULT IN LGT DRIZZLE OR
SPRINKLES. DRIZZLE WILL ONLY BE AROUND FOR THE MORNING. ONCE CLOUDS
SET UP...THINK THEY MAY STUBBORN TO LEAVE AS THERMAL TROUGHING FM
925-850MB PERSISTS ALONG WITH A CYCLONIC CONVERGENT NNE FLOW
925-850MB. KEPT BKN CLOUDS IN THROUGH EARLY AFTN WITH SCT CLOUDS
CLOUDS STAYING AROUND THROUGH MID AFTN IN THOSE UPSLOPE AREAS.
EVEN AWAY FM FAVORED AREAS NEAR LK SUPERIOR...THERMAL TROUGHING AND
DAYTIME HEATING SHOULD ACT TO INCREASE CU FOR A WHILE BEFORE
CLOUDS SCATTER OUT LATE TODAY. EXPECT RAPID CLEARING OF SKIES
LATE THIS AFTN/EARLY THIS EVENING AS SHARP 925-850MB DRYING WITH
DWPNT DEPRESSIONS OVER 15C SURGES INTO THE REGION FROM ONTARIO.
ONE ITEM TO NOTE ABOUT TODAY. A MODERATE SWIM RISK IS IN PLACE FOR
SHORELINES OF MARQUETTE AND ALGER COUNTIES AS WAVES BUILD TO 2 TO 4
FEET. LOWERING WAVES WILL LESSEN THE SWIM RISK BY THIS EVENING.
FOR TONIGHT...A COOL NIGHT IN STORE DUE TO THE CLEARING SKIES AND
LIGHT WINDS AS HIGH PRESSURE RIDGE CURRENTLY OVER MANITOBA DROPS
ACROSS REGION. WINDS FCST TO BECOME CALM OVER INTERIOR WEST CWA
WHICH WILL RESULT IN TEMPS FALLING INTO THE UPR 30S...MAYBE EVEN MID
30S. CURRENT READINGS BENEATH THE HIGH IN MANITOBA HAVE ALREADY INTO
UPR 30S AS OF 07Z. KEPT THE FROST MENTION FOR INTERIOR WEST...BUT IT
REMAINS TOO ISOLD TO MENTION IN THE HWO OR SFP.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 443 AM EDT THU JUN 13 2013
FRI...HI PRES IS FCST TO BE CENTERED OVER THE E HALF OF LK SUP ON
FRI AFTN TO THE E OF UPR RDG AXIS EXTENDING FM THE CENTRAL PLAINS
THRU THE UPR MS RIVER VALLEY AND INTO SCENTRAL CANADA DOWNSTREAM OF
CLOSED LO OVER THE CANADIAN ROCKIES JUST N OF THE BORDER. ALTHOUGH
SOME HI CLDS IN THE DVLPG SLY FLOW/WAD PATTERN BTWN THE HI AND LOWER
PRES TO THE W MAY DRIFT INTO THE WRN COUNTIES IN THE AFTN...THE DAY
SHOULD FEATURE A GOOD DEAL OF SUNSHINE WITH LLVL DRY AIRMASS IN
PLACE. H85 TEMPS FCST IN THE 11-12C RANGE AND MIXING TO H8 ON FCST
SDNGS YIELDS HI TEMPS WELL INTO THE 70S OVER THE INTERIOR W HALF
AWAY FM LK MODERATION. THE DEEP MIXING AND DRY AIRMASS IN PLACE WL
CAUSE SFC DEWPTS TO FALL INTO THE 20S IN THE AFTN OVER THE
INTERIOR...WITH MIN RH AS LO AS 20 PCT OVER THE E CLOSER TO THE CORE
OF DRIEST AIR. FORTUNATELY...WINDS WL BE LGT...SO FIRE WX CONCERNS
SHOULD BE MINIMAL.
FOCUS FOR FRI NGT THRU THE WEEKEND WL THEN SHIFT TO PCPN CHCS
ASSOCIATED WITH BROAD SW FLOW BTWN HI PRES RETREATING INTO THE MID
ATLANTIC STATES AND CLOSED LO THAT DRIFTS ONLY SLOWLY E ACRS SRN
CANADA AND TOWARD THE UPR LKS BY LATE SUN. GUIDANCE IN GOOD
AGREEMENT SHOWING SOME DEEP LYR ISENTROPIC ASCENT DVLPG ON FRI NGT
WITH BAND OF HIER MID LVL RH MOVING IN FM THE W. BUT GIVEN THE
DRYNESS OF THE ANTECENT AIRMASS...TENDENCY FOR MOST IMPRESSIVE DEEP
LYR QVECTOR CNGVC TO REMAIN WELL TO THE NW CLOSER TO THE LO ALLOWING
A MORE PERSISTENT UPR RDG AXIS OVER THE UPR LKS...AND PRESENCE OF
WARM FNT IN IOWA/ILLINOIS THAT WL INTERCEPT THE BULK OF RETURNING
LLVL MSTR...TRIMMED BACK THE EWD ADVANCE OF THE FRI NGT POPS SHOWN
IN PREVIOUS FCST TO MORE ALIGN WITH 00Z NAM/GFS/CNDN FCSTS. MIN
TEMPS ON FRI NGT SHOULD BE COOLEST OVER THE E CLOSER TO RETREATING
HI PRES RDG/DRIER AIR.
SAT/SAT NGT...NOT SURPRISINGLY...SGNFT MODEL DIFFERENCES BEGIN TO
SHOW UP IN THIS TIME PERIOD. THERE IS GOOD AGREEMENT ON PROGRESSION
OF BAND OF HIER MID LVL RH ALIGNED WITH DEEP ISENTROPIC ASCENT AND
AHEAD OF SHRTWV MOVING E THRU SW ONTARIO WELL IN ADVANCE OF SLOWER
CLOSED LO IN SASKATCHEWAN. THIS BAND OF HIER RH IS FCST TO DRIFT E
ACRS UPR MI FOLLOWED BY MID LVL DRYING IN THE JET SURGE REGION ON
THE SRN FLANK OF THE SHRTWV MOVING THRU SW ONTARIO. THE 00Z GFS IS
THEN MOST AGGRESSIVE AT DVLPG MORE SHRA/TS OVER THE W IN THE AFTN
WITH SHRTWV INTERACTING WITH THE GREATER INSTABILITY ALLOWED BY CLRG
IN THE WAKE OF THE DEPARTING MSTR AXIS. THE GFS THEN MOVES THESE
SHRA/TS E ACRS THE CWA ON SAT NGT. THE 00Z NAM ON THE OTHER HAND IS
VERY AGGRESSIVE WITH THE MID LVL JET SURGE DRYING...WITH FCST SDNGS
SHOWING EFFECTIVE MID LVL CAPPING AND ALMOST NO PCPN. PREFER THE
COMPROMISE 00Z CNDN MODEL HANDLING OF THE POPS GIVEN BETTER
PLACEMENT OF THE FEATURES RELATIVE TO CLOSED LO LINGERING BACK W OF
LK WINNIPEG THRU 12Z SUN...WITH LESS AGGRESSIVE MID LVL DRYING THAN
THE NAM AND LESS DYNAMIC SUPPORT FOR INSTABILITY SHRA/TS OVER THE W
THAN SHOWN BY THE GFS LATE SAT AFTN/NGT. BUT PASSAGE OF THIS WEAKER
SHRTWV STILL WARRANTS CHC POPS ON SAT NGT AS INDICATED BY THE CNDN
MODEL.
SUN...THERE IS A GENERAL MODEL CONSENSUS SHRTWV RDG BTWN DEPARTING
WEAK SHRTWV TO THE E AND SLOWLY APRCHG CLOSED LO FCST TO OPEN AND
APRCH NW MN LATE IN THE DAY WL BE AN INFLUENCE ON UPR MI WX. THE
RESULT SHOULD BE MAINLY DRY WX OVER THE CWA ON SUN. SO LOWERED MODEL
CONSENSUS POPS A BIT TO REFLECT THE MID LVL DRYING FCST/LACK OF
DYNAMIC SUPPORT...WHICH IS FCST TO ARRIVE ONLY LATER IN THE DAY OVER
THE W CLOSER TO APRCHG SHRTWV.
SUN NGT/MON... BEST CHC FOR SHRA/SOME TS LOOKS TO BE ON SUN NGT INTO
MON WHEN DPVA/FAIRLY VIGOROUS DEEP LYR QVECTOR CNVGC/HGT FALLS
ASSOCIATED WITH APRCHG SHRTWV FM THE WNW IMPACT THE CWA. MODEL
CONSENSUS HI CHC POPS APPEAR ON THE RIGHT TRACK.
EXTENDED...A DRIER NW FLOW ALF IN THE WAKE OF DEPARTING SHRTWV
SHOULD BRING MAINLY DRY WX TO THE UPR LKS ON TUE AND WED. ONLY
POTENTIAL FLY IN THE OINTMENT WOULD BE A STRONGER SHRTWV EMBEDDED IN
THIS FLOW...WHICH COMMONLY BRING SOME SHRA/TS TO THE AREA IN THE
SUMMER IF THERE IS ENUF MSTR/INSTABILITY. BUT NOTHING HIER THAN SCHC
POPS ARE WARRANTED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 137 AM EDT THU JUN 13 2013
NRLY WINDS WILL INCREASE BEHIND A COLD FRONT MOVING THROUGH THE AREA
OVERNIGHT. THE BEST CHANCE FOR IFR CONDITIONS ARE AT KSAW WHERE
UPSLOPE FLOW AND INCREASED LOW LEVEL MOISTURE ARE EXPECTED TO RESULT
IN A PERIOD OF LOWER CLOUDS AND SOME DRIZZLE. HIGH PRESSURE AND
DRIER AIR WILL BUILD INTO UPPER BY EARLY AFTERNOON WITH CONDITIONS
IMPROVING TO VFR.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 443 AM EDT THU JUN 13 2013
N WINDS UP TO 15-25 KTS TODAY...HIGHEST OVER THE E PART OF THE
LAKE...UNDER A SHARPER PRES GRADIENT ON THE SOUTHERN FLANK OF
BUILDING HI PRES IN ONTARIO WILL DIMINISH TONIGHT AS THE HI MOVES
TOWARD THE AREA AND THE GRADIENT SLACKENS. THEN A RELATIVELY WEAK
PRES GRADIENT AND HI OVERWATER STABILITY WILL CAUSE WINDS UNDER 15
KTS INTO EARLY NEXT WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...KC
AVIATION...JLB
MARINE...KC
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1255 AM EDT THU JUN 13 2013
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 339 PM EDT WED JUN 12 2013
STRONG LOW PRESSURE SYSTEM WILL BRING THUNDERSTORMS... SOME POSSIBLY
SEVERE WITH HEAVY RAINFALL OVERNIGHT CAUSING LOCAL FLOODING. SOME CLEARING
BY THURSDAY AFTERNOON CONTINUING INTO FRIDAY.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 339 PM EDT WED JUN 12 2013
LATEST MODEL TRENDS SUGGEST RISK OF SEVERE THUNDERSTORMS EARLY TO
MID EVENING. THERE IS A THREAT OF HEAVY RAINFALL SOUTH OF
INTERSTATE 96.
WE EXPECT A LOW LEVEL JET FOCUSED SOUTH OF I-80 INTO THE EVENING
THAT WILL RESULT IN THE STRONGEST THUNDERSTORMS TRACKING SOUTH
INTO I-94 INTO THE EARLY EVENING. THE STRONG UPPER DYNAMICS WILL
DEVELOP THE DIGGING SHORTWAVE WILL RESULT IN A TROWAL ON THE NORTH
SIDE OF THE SYSTEM OVERNIGHT THAT WILL RESULT IN A BAND OF
PERSISTENT HEAVY RAINFALL. WE EXPECT THUNDERSTORM COMPLEX TO
DEVELOP WEST OF CHICAGO BY 6 PM THEN TRACK EAST SOUTHEAST ALONG
THE MICHIGAN INDIANA BORDER DURING THE EARLY EVENING. RAINFALL
AMOUNTS OF 2 TO 3 INCHES ARE SUGGESTED BY THE HRRR... RAP AND SPC
WRF. THIS RAINFALL IS INDEPENDENT OF THE THUNDERSTORM COMPLEX THIS
EVENING.
THIS SYSTEM SHOULD EXIT THE AREA BY THE MID MORNING HOURS
THURSDAY. A TRAILING SHORTWAVE AND SECONDARY COLD FRONT DIVING
SOUTH ON THE NORTHERN STREAM JET WILL INTERACT WITH THE LAKE
MICHIGAN AND LAKE HURON LAKE BREEZE THURSDAY AFTERNOON TO CREATE
INSTABILITY SHOWERS.
RIDGING WILL MOVE INTO THE AREA THURSDAY NIGHT INTO FRIDAY
BRINGING CLEARING SKIES AND COOLER TEMPERATURES.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 339 PM EDT WED JUN 12 2013
A COUPLE OF LOW PRESSURE SYSTEMS WILL BRING POTENTIAL FOR SCATTERED
SHOWERS AND THUNDERSTORMS FROM LATE SATURDAY THROUGH SUNDAY AND
MONDAY. BEYOND THAT A CONSENSUS OF LATEST MEDIUM RANGE GUIDANCE
INCLUDING THE 12Z GFS AND 00Z ECMWF SUGGESTS HIGH PRESSURE SHOULD
BUILD IN AND BRING FAIR WX FOR THE MIDDLE PORTION OF NEXT WEEK.
TEMPS SHOULD AVERAGE RATHER CLOSE TO NORMAL THROUGH THE LONG RANGE
FORECAST PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1255 AM EDT THU JUN 13 2013
BASED ON RADAR TRENDS AND MODEL GUIDANCE...WILL DELAY END OF
PRECIPITATION TO AROUND 09-10Z. CEILINGS WILL BE TRICKY...BUT
STICKING NEAR OR JUST BELOW FUEL ALTERNATE THRESHOLDS. SOME
LOCAL OBSERVATIONS ARE REPORTING IFR CEILINGS AND IT IS POSSIBLE
THAT SOME OF OUR TERMINALS WILL BRIEFLY SEE BRIEF CEILINGS BELOW
1000 FT.
WINDS THROUGH 08Z WILL BE RELATIVELY UNCERTAIN WITH EXITING
PRECIPITATION. AFTER THAT...EXPECT DIRECTION TO SHIFT TO
NORTHEASTERLY AND THEN NORTHERLY AFTER 12Z.
&&
.MARINE...
ISSUED AT 339 PM EDT WED JUN 12 2013
WE ISSUED A SMALL CRAFT ADVISORY TONIGHT THROUGH THURSDAY NIGHT
DUE TO 20 TO 25 KNOT NORTH WINDS BEHIND THE SYSTEM WITH STRONG
COLD AIR ADVECTION.
WE ADDED FOG TO THE NEARSHORE WATERS BASED ON WEB CAMS AND
DEW POINTS IN THE UPPER 60S WHICH IS HIGHER THAN THE MID 50S LAKE
TEMPERATURES. ONCE WIND SHIFTS MID EVENING TO THE NORTH AND
BRINGS DRIER AIR IN THE FOG DISPERSE.
&&
.HYDROLOGY...
ISSUED AT 728 PM EDT WED JUN 12 2013
AN INCH OR TWO OF RAIN IS EXPECTED ACROSS MUCH OF THE KALAMAZOO
AND SAINT JOSEPH RIVER BASINS TONIGHT WITH MOST OF IT FALLING BY
06Z. THIS WILL CAUSE SOME QUICK RISES ON STREAMS WITH THE MAIN RIVER
BRANCHES SEEING RISES IN THE NEXT COUPLE DAYS. LOWERED QPF AFTER
06Z TONIGHT PER SHORT RANGE MODEL TRENDS AND COORDINATION WITH
RFC.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...FLASH FLOOD WATCH UNTIL 8 AM EDT THIS MORNING FOR MIZ056>059-
064>067-071>074.
BEACH HAZARDS STATEMENT THROUGH FRIDAY MORNING FOR MIZ043-050-
056-064-071.
LM...SMALL CRAFT ADVISORY UNTIL 8 AM EDT FRIDAY FOR LMZ844>849.
&&
$$
SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...LAURENS
AVIATION...TJT
HYDROLOGY...OSTUNO
MARINE...WDM
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
932 AM MDT THU JUN 13 2013
.UPDATE...
TIMING OF THE MAIN MID LEVEL FRONT AND THE POTENTIALLY SEVERE
THUNDERSTORMS IT MAY PRODUCE IS THE FORECAST PROBLEM TODAY.
NAM BRINGS IT INTO BILLINGS AREA (AS A FRAME OF REFERENCE) BY 6
PM...GFS BY 8 PM...AND RAP AS LATE AS 10 PM. OUR POP GRIDS ARE A
BLEND OF NAM AND GFS AT THIS TIME. RAP HAS ME WONDERING...SINCE
THE ORIENTATION OF THE TROUGH NORMALLY SUGGESTS SLOWER
MOVEMENT...BUT WE DO HAVE JET MAXES ALREADY ON EAST SIDE OF TROUGH
TO GET IT GOING EAST. WILL BE MONITORING SURFACE PRESSURE
TENDENCIES CLOSELY THROUGHOUT THE DAY IN AN ATTEMPT TO NAIL DOWN
THE GENERAL TIME FRAME FOR THREATENING WEATHER. WE WILL SEE SOME
SCATTERED CONVECTION IN THE MEANTIME MOVE UP OVER OUR FORECAST
AREA THIS MORNING IN THE WEST AND MAYBE IN THE CENTRAL ZONES THIS
AFTERNOON. THE FAR EAST SEEMS WELL CAPPED AT THIS TIME. I HAD TO
INCREASE WIND SPEEDS IN THE EASTERN BORDER SECTIONS SUCH AS BAKER
AS SE LOW LEVEL FLOW IS INCREASING A GREAT DEAL IN RESPONSE TO THE
APPROACHING UPPER TROUGH AND ASSOCIATED JET DYNAMICS. BT
&&
.SHORT TERM...VALID FOR TDY AND FRI...
OVERVIEW...CONVECTIVE INHIBITION ON WEDNESDAY REALLY LIMITED
THUNDERSTORM ACTIVITY YESTERDAY. THIS WAS MAINLY DUE TO LOW LEVEL
STRATUS THAT DEVELOPED IN THE MORNING FOLLOWING HEAVY RAINS ON
TUESDAY. LACK OF BOUNDARY LAYER WINDS IN THE MORNING ALLOWED THIS
CLOUD COVER TO PERSIST INTO MID DAY BY WHICH TIME CONVECTIVELY
INDUCED CLOUD COVER WAS ALREADY IN PLACE. AS A RESULT TEMPERATURES
WERE HELD A GOOD 10 DEGREES BELOW FORECAST EXPECTATIONS WHICH TOOK
AWAY ENERGY FOR STORMS. MID LEVEL INSTABILITY WAS THERE AND
THUNDERSTORMS DID OCCUR...BUT OUTSIDE OF A COUPLE AROUND SHERIDAN
THE STRENGTH OF STORMS WAS BELOW EXPECTATIONS. SO WHY IS TODAY
DIFFERENT...FIRST STRATUS DEVELOPMENT THIS MORNING IS EXPECTED TO
BE MINIMAL AND CONFINED TO AREAS AROUND SHERIDAN AND NEAR
HARLOWTON...WHICH SHOULD BE EASILY BURNED OFF BY THE SUN BY MID
MORNING. THIS WILL ALLOW GOOD SOLAR INSOLATION AND COMBINED WITH
PREFRONTAL WARMING AND WARM ADVECTION FROM THE SOUTH PUSH
TEMPERATURES INTO THE 75 TO 85 DEGREE RANGE. WITH DEW POINTS
REMAINING NEAR 50 DEGREES ACROSS THE AREA FORECAST CAPE VALUES OF
1500 TO 2500 JOULES SEEM REASONABLY ATTAINABLE TODAY. SHEAR VALUES
OF 40 TO 50KTS WILL SUPPORT SUSTAINED STRONG UPDRAFTS AND ENERGY
WRAPPING AROUND THE UPPER LOW TO THE WEST WILL PROVIDE LIFT ALONG
WITH A PREFRONTAL TROF AND THE COLD FRONT ITSELF. THE COLD FRONT
WILL MOVE EAST OF THE AREA BY SUNRISE WITH THE UPPER LOW MOVING
THROUGH DURING THE MORNING FRIDAY. BY FRIDAY AFTERNOON WESTERLY
WINDS WILL DRY THINGS OUT ALLOWING FOR A COOL AND DRY AFTERNOON
AND A NICE WEEKEND ACROSS THE AREA.
TODAY...AS MENTIONED ABOVE CONDITIONS LOOK FAVORABLE FOR STRONG TO
SEVERE THUNDERSTORMS TODAY INTO TONIGHT. AREAS WEST OF ROSEBUD
COUNTY WILL BE FAVORED FOR STRONGER STORMS THIS AFTERNOON AS THE
COLD FRONT MOVES INTO THIS AREA LATE IN THE DAY. AREAS TO THE
EAST WILL BE STRONGLY CAPPED DURING THE AFTERNOON BUT SHOULD AN
ISOLATED STORM MANAGE TO BREAK THE CAP THERE LATE AFTERNOON IT
WOULD LIKELY TURN SEVERE FAIRLY QUICKLY WITH CAPE VALUES OVER 2500
JOULES PROGGED THERE ALONG WITH FAVORABLE SHEAR. COLD FRONT SHOULD
MOVE THROUGH THE REST OF THE FORECAST AREA DURING THE EVENING
HOURS PUSHING THE SEVERE THREAT ALONG AND AHEAD OF IT.
PRECIPITABLE WATER VALUES OVER AN INCH WILL PERSIST AHEAD OF AND
SLIGHTLY BEHIND THE COLD FRONT LEADING TO THE POTENTIAL FOR HEAVY
RAINFALL WITH STORM TODAY INTO TONIGHT. AS A RESULT FLASH FLOOD
WATCHES REMAIN IN EFFECT TIL MIDNIGHT TONIGHT FOR AREAS BURNED BY
2012 WILDFIRES AS WELL AS SHERIDAN...GOLDEN VALLEY AND NORTHERN
STILLWATER COUNTIES WHERE HEAVY RAIN OCCURRED DURING THE PAST FEW
DAYS. BEHIND THE FRONT EXPECT WIDESPREAD SHOWER ACTIVITY WITH A
FEW EMBEDDED THUNDERSTORMS AS STRONG QG FORCING AND MID LEVEL
FRONTOGENESIS BUILDS IN FROM THE WEST. 700MB TEMPERATURES WILL
FALL BELOW 0C EARLY FRIDAY MORNING ALLOWING FOR SOME LIGHT SNOW
ACCUMULATION IN THE WESTERN MOUNTAINS ABOVE 8000 FEET.
FRIDAY...UPPER LOW WILL MOVE ACROSS WESTERN ZONES BEFORE TURNING
MORE NORTHWARD MID TO LATE MORNING. AS A RESULT BEST CHANCES FOR
PRECIPITATION WILL BE WEST WHILE EASTERN AREAS WILL LIKELY DRY OUT
EARLY IN THE DAY. WEST TO NORTHWEST WINDS WILL BE GUSTY FRIDAY
AFTERNOON AND THIS DOWNSLOPE FLOW WILL HELP DRY OUT THE LOWER
LEVELS OF THE ATMOSPHERE. TEMPERATURES WILL STILL BE COOL FOR THIS
TIME OF YEAR WITH HIGHS MAINLY IN THE 60S TO LOW 70S...AND THAT
NORTHWEST WIND WILL MAKE IT FEEL COOLER THAN THAT. THE THREAT FOR
FLASH FLOODING AND SEVERE THUNDERSTORMS SHOULD BE OVER FOR THE
NEXT SEVERAL DAYS AT LEAST ONCE WE GET PAST THURSDAY NIGHT.
CHAMBERS
.LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED...
THE EXTENDED FORECAST BEGINS ON SATURDAY WITH A PERIOD OF QUIET
WEATHER THROUGH THE WEEKEND AS ZONAL FLOW ALOFT TRANSITIONS TO
RIDGING ALOFT BY EARLY NEXT WEEK. TEMPERATURES WILL SEE A SLOW
WARMING TREND FROM THE MID 70S TO THE MID 80S THROUGH THIS PERIOD
AS HEIGHTS RISE OVER THE FORECAST AREA WITH THE RIDGE BUILDING IN.
WESTERLY WINDS ON SATURDAY WILL KEEP THE FORECAST AREA DRY. A WEAK
COLD FRONT BACKS INTO THE FORECAST AREA SATURDAY NIGHT...BUT WITH
LIMITED MOISTURE TO WORK WITH THIS WILL REMAIN A DRY FRONT. WINDS
WILL TURN TO THE EAST AND SOUTHEAST UNDER THE RIDGING ALOFT BY
EARLY NEXT WEEK. THIS WILL HELP TO INCREASE DEW POINTS AND BRING A
SLOWLY INCREASING CHANCE FOR SHOWER AND THUNDERSTORMS BY MID TO
LATE NEXT WEEK. THE INCREASING CHANCES OF PRECIPITATION WILL COME
TO A HEAD BY WEDNESDAY INTO THURSDAY AS THE NEXT PACIFIC WAVE
IS SET TO MOVE ACROSS THE FORECAST AREA. CHURCH
&&
.AVIATION...
A FEW SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE ALONG AND WEST
OF A KSHR-KBIL LINE THIS MORNING. EXPECT MVFR TO LIFR CONDITIONS
IN AND NEAR THIS ACTIVITY. A STRONG COLD FRONT WILL APPROACH THE
KLVM TO HARLOWTON AREAS BY EARLY AFTERNOON AND MOVE EAST DURING
THE AFTERNOON AND EVENING HOURS. EXPECT ANOTHER ROUND OF
THUNDERSTORMS ALONG AND AHEAD OF THE FRONT WITH THE BEST CHANCES
FOR THE KBIL AND KSHR AREAS FROM MID AFTERNOON INTO THE EARLY
EVENING HOURS. THE THUNDERSTORM ACTIVITY WILL SHIFT EAST TOWARD
THE KMLS AND KBHK AREAS LATE THIS EVENING. HEAVY RAIN...LARGE HAIL
AND STRONG WIND GUSTS AROUND 50KTS WILL BE POSSIBLE WITH THE
THUNDERSTORMS. EXPECT MVFR TO LIFR CONDITIONS IN AND NEAR ANY
THUNDERSTORM. THE MOUNTAINS WILL AGAIN BE OBSCURED AT TIMES
THROUGH THIS EVENING. HOOLEY
&&
.PRELIMINARY POINT TEMP/POPS...
TDY FRI SAT SUN MON TUE WED
-------------------------------------------------------
BIL 083 050/067 047/078 051/079 052/080 055/085 052/077
3/T 64/T 10/U 01/U 12/T 22/T 22/T
LVM 076 042/062 042/078 043/079 045/081 046/084 049/075
4/T 65/T 10/U 01/U 12/T 22/T 22/T
HDN 085 051/069 046/078 050/080 051/080 056/088 052/081
3/T 64/T 10/U 11/U 12/T 22/T 22/T
MLS 085 054/071 050/078 053/079 053/078 055/084 057/082
2/T 64/T 10/U 11/U 12/T 22/T 22/T
4BQ 086 053/071 046/078 050/080 051/079 055/087 055/087
1/B 53/T 10/U 11/U 12/T 22/T 21/U
BHK 080 053/070 047/076 050/075 050/075 054/080 058/079
1/N 63/T 10/U 11/U 12/T 22/T 21/U
SHR 085 049/067 043/078 047/078 049/079 053/086 050/085
2/T 62/T 10/U 11/U 12/T 22/T 22/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...FLASH FLOOD WATCH IN EFFECT THROUGH THIS EVENING FOR ZONES
29-31-34-36>38-42-57-58-64-65-67.
WY...FLASH FLOOD WATCH IN EFFECT THROUGH THIS EVENING FOR ZONE 99.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
308 PM CDT THU JUN 13 2013
.DISCUSSION...
THUNDERSTORM COMPLEX...INITIALLY PROBABLY ROOTED NEAR H6 PER
LBF/OAX 12Z SOUNDINGS...CONTINUED WORKING INTO FORECAST AREA THIS
AFTERNOON DESPITE LACK OF LOW LEVEL JET/INSTABILITY SUPPORT. THIS
HIGHLIGHTS UNCERTAINTIES THAT WILL EXIST IN FINE-TUNING
THUNDERSTORM CHCS AND TIMES THROUGH THIS WEEKEND AND IS THE
PRIMARY FORECAST CONCERN.
CURRENT RADAR TRENDS/LATEST RAP FCST WOULD TAKE THIS AREA OF
CONVECTION OUT OF ERN ZONES BY AROUND 02Z WITH A PROBABLE PRECIP
LULL UNTIL CONVECTION DEVELOPING TO OUR WEST APPROACHES OR
DEVELOPS INTO ZONES LATER TONIGHT. MADE SOME ATTEMPTS AT
ADJUSTING HOURLY GRIDS TO REFLECT THIS TREND TONIGHT.
HOWEVER...AFTER THAT RELUCTANT TO REMOVE OR LOWER TOMORROW MORNING
POPS VERY MUCH...ESPECIALLY CNTRL/NE ZONES AS 00Z/12Z ECMWF AND
12Z GFS CONTINUED TO DEVELOP QPF OVER THE NERN FA IN 12-18Z PD.
SINCE THIS AREA WILL BE ON NOSE OF THE MOISTURE/INSTABILITY RETURN
NOTED BY STRONG H85 THETA E ADVECTION IN 12Z-15Z PERIOD PER
NAM...LEFT IN LIKELY MORNING POPS NERN ZONES. ALTHOUGH THERE COULD
BE A MIDDAY LULL IN THE ACTIVITY...THIS THETA ADVECTION INCREASES
AGAIN IN THE AFTERNOON. THUS CANNOT REALLY SAY WHETHER OR NOT
CONVECTION WILL COMPLETELY DIE OUT...WHICH HAS BEEN THE CASE TODAY
AND WAS A FEW DAYS AGO AS WELL. SFC BASED DWPT RETURN PER NAM/GFS
PROBABLY TOO HIGH THUS SFC BASED CAPE FORECAST ALSO TOO HIGH
FRIDAY...BUT WITH BOUNDARY IN AREA AND UPPER WAVE LIFTING INTO
NERN MT...SOME SEVERE THREAT WILL PROBABLY EXIST. HOWEVER...
COVERAGE PROBABLY DICTATED BY EFFECTIVENESS OF CAP WHICH WILL BE
TRYING TO BECOME ESTABLISHED...ESPECIALLY SRN ZONES...OR DEBRIS
CLOUDS/PCPN FROM ANY MORNING ACTIVITY NE. AT THIS TIME MADE
LITTLE/NO CHANCES TO MAX TEMPS WHICH WILL LIKELY NEED ADJUSTING AS
AMOUNT OF DEBRIS BECOMES APPARENT.
WITH BOUNDARY REMAINING OVER AREA SATURDAY AND POSSIBLY SUNDAY...
AND CNTRL PLAINS CONTINUING ON SRN END OF WESTERLIES OF SRN
CANADIAN LOW...MODESTLY HIGH POPS WARRANTED INTO SUNDAY. ALTHOUGH
AGAIN WOULD GENERALLY THINK CENTROID OF MCS ACTIVITY ON SYNOPTIC
SCALE COULD SHIFT SOUTH EACH DAY THUS HIGHER CHCS WOULD APPEAR TO
SHIFT INTO SRN ZONES BY SUNDAY/SUNDAY NIGHT. WITH ERLY FLOW
SETTING UP SATURDAY BEHIND EXPECTED MCS TOMORROW NIGHT...LEANED
TOWARD COOLER NAM FOR MAX TEMPS. NO CHANGES TO SUNDAY MAX TEMPS AT
THIS TIME.
DRIER WEATHER STILL ON TAP MONDAY AND PROBABLY TUESDAY AS WELL AS
NWRLY FLOW SENDS HIGH PRESSURE THROUGH ERN PLAINS AND FORECAST WAS
MOSTLY DRY. AFTER THAT...RETURNING MOISTURE WILL BRING INCREASING
TSTM RISK THRU END OF WEEK ALTHOUGH FOR THE TIME BEING KEPT MOST
POPS IN LOWER CHC RANGE.
CHERMOK
&&
.AVIATION...
18Z TAFS FOR KOFK...KLNK AND KOMA.
VFR CONDITIONS ARE EXPECTED THROUGH MOST OF THE TAF PERIOD AS HIGH
PRESSURE BRINGS LIGHT NORTH WINDS AND MAINLY SCATTERED TO BROKEN MID
AND HIGH CLOUDS. THIS AFTERNOON ISOLATED SHOWERS AND THUNDERSTORMS
WILL MOVE THROUGH THE TAF SITES AND SHOULD EXIT BY 00Z TONIGHT.
REDEVELOPMENT IS POSSIBLE LATE TONIGHT...THUS LEFT PROB30 GROUP IN
THOUGH CONFIDENCE IS LOW.
PEARSON
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1229 PM CDT THU JUN 13 2013
.SYNOPSIS...
ISSUED AT 335 AM CDT THU JUN 13 2013
PROGRESSIVE UPPER PATTERN CONTINUES ACROSS THE
COUNTRY...INCLUDING SEASONALLY HIGH AMPLITUDE RIDGE MOVING ACROSS
THE NORTHERN ROCKIES. FURTHER UPSTREAM...UPPER LOW MOVING ONSHORE
ACROSS THE PAC NW LEADING TO DECENT JET AXIS ACROSS THE CENTRAL
ROCKIES BASED ON EVENING UA ANALYSIS. AT THE SFC...HIGH PRESSURE
ACROSS THE NORTHERN PLAINS YIELDING ERLY UPSLOPE FLOW ACROSS THE
STATE. STATIONARY FRONT LOCATED ACROSS SRN KS AND NORTH OF THIS
FRONT SPC MESOANALYSIS HAS INDICATED DECREASING MID LEVEL LAPSE
RATES AS WARM AIR ADVECTION INCREASES ALOFT. COOLING CLOUD TOPS
INDICATED IN IR SAT PICS IN NERN CO AND NRN KS IN RESPONSE TO
INCREASING MID LEVEL FRONTOGENESIS.
&&
.UPDATE...
ISSUED AT 647 AM CDT THU JUN 13 2013
UPDATED FORECAST TO REFLECT THE MENTION OF THUNDER TO THE EXISTING
PRECIPITATION GRIDS...THE PLACEMENT OF WHICH WAS ON TRACK. REST OF
THE FCST LOOKS INGOOD SHAPE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 335 AM CDT THU JUN 13 2013
IN THE VERY SHORT TERM...THROUGH NOON TODAY...ISOLD SHRA WILL BE
POSSIBLE IN THE WEST INITIALLY TO COVER ECHOES ON RADAR GENERATED
BY A WESTWARD MOVING BOUNDARY SEEN EARLIER ON THE KFTG 88D. AS
MENTIONED EARLIER...ELEVATED INSTABILITY IS PRESENT AND RAP SHORT
TERM FCSTS SHOW MID LEVEL FRONTOGENESIS AS THE THERMAL GRADIENT
TIGHTENS AS A RESULT OF THE WAA AS MENTIONED. THEREFORE WILL
INCLUDE ISOLD SHRA MENTION IN SOUTHWEST THIS MORNING...THOUGH THIS
WILL BE A LOW QPF /IF ANY AT ALL/ EVENT. MAY BE A LIGHTNING STRIKE
OR TWO BUT LATEST INFO SUGGESTS SOME WEAKENING CURRENTLY.
IN RESPONSE TO THE JET COMING ACROSS THE CENTRAL ROCKIES SFC
PRESSURES WILL LOWER OVER THE NORTHERN HIGH PLAINS THRU THE DAY
TODAY. WINDS WILL BECOME SOUTHEAST AND WILL RESULT IN AN INCREASE
IN LOW LEVEL MOISTURE IN THE NEXT 24 HRS. SEVERAL SMALL PV
ANOMALIES ARE EMBEDDED WITHIN THE QUICK FLOW AND WILL SERVE TO
ENHANCE LOW LEVEL CONVERGENCE AS A THERMAL GRADIENT DEVELOPS ALONG
THE HIGHER TERRAIN. THIS SHOULD YIELD A FAVORABLE PATTERN OF
INSTABILITY ALOFT AS AN EML ADVECTS EASTWARD ATOP LOW LEVEL
MOISTURE ADVECTION. HOWEVER...SFC BASED INSTABILITY WILL REMAIN
LACKING IN THIS PATTERN WHICH WOULD MEAN THE BEST FORCING FOR
ASCENT AND SUBSEQUENT TSRA DEVELOPMENT WOULD BE MOST FAVORABLE
ACROSS THE HIGHER TERRAIN FURTHER WEST...AND THEN MOVE EAST
SUPPORTED BY THE FAVORABLE ELEVATED INSTABILITY. MODELS HAVE THIS
IDEA HANDLED FAIRLY WELL...HOWEVER AS EXPECTED FINE SCALE DETAIL
REMAIN A CHALLENGE. INCREASING MID AND HIGH LEVEL CLOUDINESS AND
EVEN SMOKE FROM FIRES IN COLORADO COULD MAKE TEMP FCSTS A TRICK
TODAY BUT WILL BE COOLER IN THE SOUTHWEST THAN YDAY WARMER IN THE
NORTH.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 335 AM CDT THU JUN 13 2013
FRIDAY MORNING WILL SEE A LINGERING CHANCE FOR THUNDERSTORMS
ACROSS PARTS OF NORTH CENTRAL NEB AS OVERNIGHT CONVECTION
CONTINUES TO PROPAGATE EASTWARD. STALLED SFC BOUNDARY STRETCHES
FROM LOW OVER NW KS NORTHWARD TO A LOW OVER THE PLAINS OF CANADA.
UPPER LEVEL RIDGE REMAINS OVER THE SOUTHERN PLAINS. LOW
CONFIDENCE ON HIGHS...AS SEVERAL THINGS TO CONSIDER. WARM TEMPS
ALOFT SHOULD PRECLUDE ANY THUNDERSTORM DEVELOPMENT UNTIL LATE IN
THE AFTERNOON...MORE SUN AND WARM...HOWEVER DEPENDING ON
PLACEMENT OF THE SFC BOUNDARY...EXPECT SLIGHTLY COOLER TEMPS TO
THE WEST. HAVE SIDED TOWARDS THE WARMER GUIDANCE TO THE
SOUTH...SEEING MORE INFLUENCE FOR THE WARMER TEMPS ALOFT FROM THE
RIDGE AND RECENT WARMER PERFORMANCE. MORE OF A MODEL BLEND ACROSS
THE NORTH. AS FOR THE AFTERNOON THUNDERSTORMS...GOOD INSTABILITY
WILL HAVE TO OVERCOME STRONG CAP. ISOLD DEVELOPMENT IS EXPECTED
NEAR THE BOUNDARY...THEN SHOULD PUSH NE DUE TO THE SOUTHWEST FLOW
THROUGH THE OVERNIGHT HOURS. CAP MAY KEEP CELLS MORE
DISCRETE...ALTHOUGH EXPECTING MORE OF A COMPLEX AT THIS TIME.
SATURDAY THE FRONT WILL SHIFT SOUTH WITH THE MAIN CONVECTION TO
PUSH SOUTH WITH IT. HOWEVER ELEVATED MOISTURE WILL WRAP AROUND
THE RIDGE...ALONG THE ROCKIES INTO THE HIGH PLAINS. ALSO SEEING A
COUPLE OF WAVES RIDE THE PERIPHERY OF THE RIDGE. THUS WILL
CONTINUE TO SEE THE CHANCE FOR AFTERNOON AND OVERNIGHT ELEVATED
CONVECTION. TEMPS A LITTLE COOLER WITH HIGHS GENERALLY IN THE
80S. OVERNIGHT TEMPS MORE QUESTIONABLE AS CLOUDS WILL KEEP TEMPS
UP IN THE LOWER 60S...HOWEVER ANY CLEARING WILL ALLOW TEMPS TO
FALL INTO THE 50S.
EARLY NEXT WEEK THE RIDGE RETROGRADES AND BUILDS ACROSS THE
SOUTHERN ROCKIES. FLOW BECOMES MORE NORTHWESTERLY WITH A
CONTINUED CHANCE FOR CONVECTION...MAINLY AFTERNOON/EVENING IN THE
WEST...PUSHING TO THE EAST...EVENING/OVERNIGHT. TEMPS STILL IN
THE 80S MONDAY AND TUESDAY...THEN WARMING AS THE RIDGE EXPANDS
EASTWARD FOR MID WEEK. HIGHS SHOULD WARM TO THE MID 80S TO MID
90S...POSSIBLY WARMER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1226 PM CDT THU JUN 13 2013
AVIATION CONCERNS OVER THE NEXT 24 HOURS CENTER AROUND THE CHANCES
FOR THUNDERSTORMS THIS EVENING INTO THE OVERNIGHT HOURS. HAVE
INCLUDED -TSRA IN THE KLBF TAF TONIGHT WITH MOST HI-RES MODELS
SHOWING SCATTERED CONVECTION MOVING OUT OF COLORADO AND INTO
SOUTHWEST NEBRASKA. STORMS WILL BE CAPABLE OF PRODUCING GUSTY
WINDS AND BRIEF HEAVY RAINFALL. HAVE LEFT ANY MENTION OF TS OUT OF
THE KVTN TAF WHERE CONFIDENCE IS MUCH LOWER ATTM.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JWS
SYNOPSIS...JWS
SHORT TERM...JWS
LONG TERM...MASEK
AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
647 AM CDT THU JUN 13 2013
.SYNOPSIS...
ISSUED AT 335 AM CDT THU JUN 13 2013
PROGRESSIVE UPPER PATTERN CONTINUES ACROSS THE
COUNTRY...INCLUDING SEASONALLY HIGH AMPLITUDE RIDGE MOVING ACROSS
THE NORTHERN ROCKIES. FURTHER UPSTREAM...UPPER LOW MOVING ONSHORE
ACROSS THE PAC NW LEADING TO DECENT JET AXIS ACROSS THE CENTRAL
ROCKIES BASED ON EVENING UA ANALYSIS. AT THE SFC...HIGH PRESSURE
ACROSS THE NORTHERN PLAINS YIELDING ERLY UPSLOPE FLOW ACROSS THE
STATE. STATIONARY FRONT LOCATED ACROSS SRN KS AND NORTH OF THIS
FRONT SPC MESOANALYSIS HAS INDICATED DECREASING MID LEVEL LAPSE
RATES AS WARM AIR ADVECTION INCREASES ALOFT. COOLING CLOUD TOPS
INDICATED IN IR SAT PICS IN NERN CO AND NRN KS IN RESPONSE TO
INCREASING MID LEVEL FRONTOGENESIS.
&&
.UPDATE...
ISSUED AT 647 AM CDT THU JUN 13 2013
UPDATED FORECAST TO REFLECT THE MENTION OF THUNDER TO THE EXISTING
PRECIPITATION GRIDS...THE PLACEMENT OF WHICH WAS ON TRACK. REST OF
THE FCST LOOKS INGOOD SHAPE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 335 AM CDT THU JUN 13 2013
IN THE VERY SHORT TERM...THROUGH NOON TODAY...ISOLD SHRA WILL BE
POSSIBLE IN THE WEST INITIALLY TO COVER ECHOES ON RADAR GENERATED
BY A WESTWARD MOVING BOUNDARY SEEN EARLIER ON THE KFTG 88D. AS
MENTIONED EARLIER...ELEVATED INSTABILITY IS PRESENT AND RAP SHORT
TERM FCSTS SHOW MID LEVEL FRONTOGENESIS AS THE THERMAL GRADIENT
TIGHTENS AS A RESULT OF THE WAA AS MENTIONED. THEREFORE WILL
INCLUDE ISOLD SHRA MENTION IN SOUTHWEST THIS MORNING...THOUGH THIS
WILL BE A LOW QPF /IF ANY AT ALL/ EVENT. MAY BE A LIGHTNING STRIKE
OR TWO BUT LATEST INFO SUGGESTS SOME WEAKENING CURRENTLY.
IN RESPONSE TO THE JET COMING ACROSS THE CENTRAL ROCKIES SFC
PRESSURES WILL LOWER OVER THE NORTHERN HIGH PLAINS THRU THE DAY
TODAY. WINDS WILL BECOME SOUTHEAST AND WILL RESULT IN AN INCREASE
IN LOW LEVEL MOISTURE IN THE NEXT 24 HRS. SEVERAL SMALL PV
ANOMALIES ARE EMBEDDED WITHIN THE QUICK FLOW AND WILL SERVE TO
ENHANCE LOW LEVEL CONVERGENCE AS A THERMAL GRADIENT DEVELOPS ALONG
THE HIGHER TERRAIN. THIS SHOULD YIELD A FAVORABLE PATTERN OF
INSTABILITY ALOFT AS AN EML ADVECTS EASTWARD ATOP LOW LEVEL
MOISTURE ADVECTION. HOWEVER...SFC BASED INSTABILITY WILL REMAIN
LACKING IN THIS PATTERN WHICH WOULD MEAN THE BEST FORCING FOR
ASCENT AND SUBSEQUENT TSRA DEVELOPMENT WOULD BE MOST FAVORABLE
ACROSS THE HIGHER TERRAIN FURTHER WEST...AND THEN MOVE EAST
SUPPORTED BY THE FAVORABLE ELEVATED INSTABILITY. MODELS HAVE THIS
IDEA HANDLED FAIRLY WELL...HOWEVER AS EXPECTED FINE SCALE DETAIL
REMAIN A CHALLENGE. INCREASING MID AND HIGH LEVEL CLOUDINESS AND
EVEN SMOKE FROM FIRES IN COLORADO COULD MAKE TEMP FCSTS A TRICK
TODAY BUT WILL BE COOLER IN THE SOUTHWEST THAN YDAY WARMER IN THE
NORTH.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 335 AM CDT THU JUN 13 2013
FRIDAY MORNING WILL SEE A LINGERING CHANCE FOR THUNDERSTORMS
ACROSS PARTS OF NORTH CENTRAL NEB AS OVERNIGHT CONVECTION
CONTINUES TO PROPAGATE EASTWARD. STALLED SFC BOUNDARY STRETCHES
FROM LOW OVER NW KS NORTHWARD TO A LOW OVER THE PLAINS OF CANADA.
UPPER LEVEL RIDGE REMAINS OVER THE SOUTHERN PLAINS. LOW
CONFIDENCE ON HIGHS...AS SEVERAL THINGS TO CONSIDER. WARM TEMPS
ALOFT SHOULD PRECLUDE ANY THUNDERSTORM DEVELOPMENT UNTIL LATE IN
THE AFTERNOON...MORE SUN AND WARM...HOWEVER DEPENDING ON
PLACEMENT OF THE SFC BOUNDARY...EXPECT SLIGHTLY COOLER TEMPS TO
THE WEST. HAVE SIDED TOWARDS THE WARMER GUIDANCE TO THE
SOUTH...SEEING MORE INFLUENCE FOR THE WARMER TEMPS ALOFT FROM THE
RIDGE AND RECENT WARMER PERFORMANCE. MORE OF A MODEL BLEND ACROSS
THE NORTH. AS FOR THE AFTERNOON THUNDERSTORMS...GOOD INSTABILITY
WILL HAVE TO OVERCOME STRONG CAP. ISOLD DEVELOPMENT IS EXPECTED
NEAR THE BOUNDARY...THEN SHOULD PUSH NE DUE TO THE SOUTHWEST FLOW
THROUGH THE OVERNIGHT HOURS. CAP MAY KEEP CELLS MORE
DISCRETE...ALTHOUGH EXPECTING MORE OF A COMPLEX AT THIS TIME.
SATURDAY THE FRONT WILL SHIFT SOUTH WITH THE MAIN CONVECTION TO
PUSH SOUTH WITH IT. HOWEVER ELEVATED MOISTURE WILL WRAP AROUND
THE RIDGE...ALONG THE ROCKIES INTO THE HIGH PLAINS. ALSO SEEING A
COUPLE OF WAVES RIDE THE PERIPHERY OF THE RIDGE. THUS WILL
CONTINUE TO SEE THE CHANCE FOR AFTERNOON AND OVERNIGHT ELEVATED
CONVECTION. TEMPS A LITTLE COOLER WITH HIGHS GENERALLY IN THE
80S. OVERNIGHT TEMPS MORE QUESTIONABLE AS CLOUDS WILL KEEP TEMPS
UP IN THE LOWER 60S...HOWEVER ANY CLEARING WILL ALLOW TEMPS TO
FALL INTO THE 50S.
EARLY NEXT WEEK THE RIDGE RETROGRADES AND BUILDS ACROSS THE
SOUTHERN ROCKIES. FLOW BECOMES MORE NORTHWESTERLY WITH A
CONTINUED CHANCE FOR CONVECTION...MAINLY AFTERNOON/EVENING IN THE
WEST...PUSHING TO THE EAST...EVENING/OVERNIGHT. TEMPS STILL IN
THE 80S MONDAY AND TUESDAY...THEN WARMING AS THE RIDGE EXPANDS
EASTWARD FOR MID WEEK. HIGHS SHOULD WARM TO THE MID 80S TO MID
90S...POSSIBLY WARMER.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 647 AM CDT THU JUN 13 2013
MID LEVEL CLOUDINESS INCREASING ACROSS THE FAR SWRN PORTION OF THE
STATE ON TRACK AS MODELS SUGGEST WARM AIR ADVECTION LEADING TO MID
LEVEL FRONTOGENESIS TO GO ALONG WITH SOME ELEVATED INSTABILITY. WEAK
RETURNS ALSO SHOWING UP ON KLNX 88D IN PERKINS AND KEITH COUNTIES.
DESPITE THIS DRY LOW LEVELS SHOULD PRECLUDE ANY DECENT RAIN MAKING
IT TO THE GROUND AND EXPECT CONVERAGE TO BE LIMITED SO HAVE LEFT
MENTION OF SHRA/TSRA OUT OF THE KLBF TAF THIS MORNING BUT WILL
MONITOR. HOWEVER...HAVE INCLUDED MENTION OF TSRA TONIGHT AT KLBF
AS CONVECTIVE INITIATION FURTHER WEST MOVES INTO THE AREA THIS
EVENING AND OVERNIGHT. IF CONVECTION DOES DEVELOP OVERNIGHT THERE
WOULD ALSO BE SOME CHC OF FOG OR STRATUS TOWARD DAYBREAK
FRIDAY...BUT AT THIS TIME CONFIDENCE IS NOT HIGH ENOUGH TO
INCLUDE. FOR KVTN...MAINLY MID CLOUDS WITH THE BELIEF THAT BEST
CONVECTIVE POTENTIAL TONIGHT WILL BE SOUTH OF KVTN TERMINAL.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JWS
SYNOPSIS...JWS
SHORT TERM...JWS
LONG TERM...MASEK
AVIATION...JWS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
335 AM CDT THU JUN 13 2013
.SYNOPSIS...
ISSUED AT 335 AM CDT THU JUN 13 2013
PROGRESSIVE UPPER PATTERN CONTINUES ACROSS THE
COUNTRY...INCLUDING SEASONALLY HIGH AMPLITUDE RIDGE MOVING ACROSS
THE NORTHERN ROCKIES. FURTHER UPSTREAM...UPPER LOW MOVING ONSHORE
ACROSS THE PAC NW LEADING TO DECENT JET AXIS ACROSS THE CENTRAL
ROCKIES BASED ON EVENING UA ANALYSIS. AT THE SFC...HIGH PRESSURE
ACROSS THE NORTHERN PLAINS YIELDING ERLY UPSLOPE FLOW ACROSS THE
STATE. STATIONARY FRONT LOCATED ACROSS SRN KS AND NORTH OF THIS
FRONT SPC MESOANALYSIS HAS INDICATED DECREASING MID LEVEL LAPSE
RATES AS WARM AIR ADVECTION INCREASES ALOFT. COOLING CLOUD TOPS
INDICATED IN IR SAT PICS IN NERN CO AND NRN KS IN RESPONSE TO
INCREASING MID LEVEL FRONTOGENESIS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 335 AM CDT THU JUN 13 2013
IN THE VERY SHORT TERM...THROUGH NOON TODAY...ISOLD SHRA WILL BE
POSSIBLE IN THE WEST INITIALLY TO COVER ECHOES ON RADAR GENERATED
BY A WESTWARD MOVING BOUNDARY SEEN EARLIER ON THE KFTG 88D. AS
MENTIONED EARLIER...ELEVATED INSTABILITY IS PRESENT AND RAP SHORT
TERM FCSTS SHOW MID LEVEL FRONTOGENESIS AS THE THERMAL GRADIENT
TIGHTENS AS A RESULT OF THE WAA AS MENTIONED. THEREFORE WILL
INCLUDE ISOLD SHRA MENTION IN SOUTHWEST THIS MORNING...THOUGH THIS
WILL BE A LOW QPF /IF ANY AT ALL/ EVENT. MAY BE A LIGHTNING STRIKE
OR TWO BUT LATEST INFO SUGGESTS SOME WEAKENING CURRENTLY.
IN RESPONSE TO THE JET COMING ACROSS THE CENTRAL ROCKIES SFC
PRESSURES WILL LOWER OVER THE NORTHERN HIGH PLAINS THRU THE DAY
TODAY. WINDS WILL BECOME SOUTHEAST AND WILL RESULT IN AN INCREASE
IN LOW LEVEL MOISTURE IN THE NEXT 24 HRS. SEVERAL SMALL PV
ANOMALIES ARE EMBEDDED WITHIN THE QUICK FLOW AND WILL SERVE TO
ENHANCE LOW LEVEL CONVERGENCE AS A THERMAL GRADIENT DEVELOPS ALONG
THE HIGHER TERRAIN. THIS SHOULD YIELD A FAVORABLE PATTERN OF
INSTABILITY ALOFT AS AN EML ADVECTS EASTWARD ATOP LOW LEVEL
MOISTURE ADVECTION. HOWEVER...SFC BASED INSTABILITY WILL REMAIN
LACKING IN THIS PATTERN WHICH WOULD MEAN THE BEST FORCING FOR
ASCENT AND SUBSEQUENT TSRA DEVELOPMENT WOULD BE MOST FAVORABLE
ACROSS THE HIGHER TERRAIN FURTHER WEST...AND THEN MOVE EAST
SUPPORTED BY THE FAVORABLE ELEVATED INSTABILITY. MODELS HAVE THIS
IDEA HANDLED FAIRLY WELL...HOWEVER AS EXPECTED FINE SCALE DETAIL
REMAIN A CHALLENGE. INCREASING MID AND HIGH LEVEL CLOUDINESS AND
EVEN SMOKE FROM FIRES IN COLORADO COULD MAKE TEMP FCSTS A TRICK
TODAY BUT WILL BE COOLER IN THE SOUTHWEST THAN YDAY WARMER IN THE
NORTH.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 335 AM CDT THU JUN 13 2013
FRIDAY MORNING WILL SEE A LINGERING CHANCE FOR THUNDERSTORMS
ACROSS PARTS OF NORTH CENTRAL NEB AS OVERNIGHT CONVECTION
CONTINUES TO PROPAGATE EASTWARD. STALLED SFC BOUNDARY STRETCHES
FROM LOW OVER NW KS NORTHWARD TO A LOW OVER THE PLAINS OF CANADA.
UPPER LEVEL RIDGE REMAINS OVER THE SOUTHERN PLAINS. LOW
CONFIDENCE ON HIGHS...AS SEVERAL THINGS TO CONSIDER. WARM TEMPS
ALOFT SHOULD PRECLUDE ANY THUNDERSTORM DEVELOPMENT UNTIL LATE IN
THE AFTERNOON...MORE SUN AND WARM...HOWEVER DEPENDING ON
PLACEMENT OF THE SFC BOUNDARY...EXPECT SLIGHTLY COOLER TEMPS TO
THE WEST. HAVE SIDED TOWARDS THE WARMER GUIDANCE TO THE
SOUTH...SEEING MORE INFLUENCE FOR THE WARMER TEMPS ALOFT FROM THE
RIDGE AND RECENT WARMER PERFORMANCE. MORE OF A MODEL BLEND ACROSS
THE NORTH. AS FOR THE AFTERNOON THUNDERSTORMS...GOOD INSTABILITY
WILL HAVE TO OVERCOME STRONG CAP. ISOLD DEVELOPMENT IS EXPECTED
NEAR THE BOUNDARY...THEN SHOULD PUSH NE DUE TO THE SOUTHWEST FLOW
THROUGH THE OVERNIGHT HOURS. CAP MAY KEEP CELLS MORE
DISCRETE...ALTHOUGH EXPECTING MORE OF A COMPLEX AT THIS TIME.
SATURDAY THE FRONT WILL SHIFT SOUTH WITH THE MAIN CONVECTION TO
PUSH SOUTH WITH IT. HOWEVER ELEVATED MOISTURE WILL WRAP AROUND
THE RIDGE...ALONG THE ROCKIES INTO THE HIGH PLAINS. ALSO SEEING A
COUPLE OF WAVES RIDE THE PERIPHERY OF THE RIDGE. THUS WILL
CONTINUE TO SEE THE CHANCE FOR AFTERNOON AND OVERNIGHT ELEVATED
CONVECTION. TEMPS A LITTLE COOLER WITH HIGHS GENERALLY IN THE
80S. OVERNIGHT TEMPS MORE QUESTIONABLE AS CLOUDS WILL KEEP TEMPS
UP IN THE LOWER 60S...HOWEVER ANY CLEARING WILL ALLOW TEMPS TO
FALL INTO THE 50S.
EARLY NEXT WEEK THE RIDGE RETROGRADES AND BUILDS ACROSS THE
SOUTHERN ROCKIES. FLOW BECOMES MORE NORTHWESTERLY WITH A
CONTINUED CHANCE FOR CONVECTION...MAINLY AFTERNOON/EVENING IN THE
WEST...PUSHING TO THE EAST...EVENING/OVERNIGHT. TEMPS STILL IN
THE 80S MONDAY AND TUESDAY...THEN WARMING AS THE RIDGE EXPANDS
EASTWARD FOR MID WEEK. HIGHS SHOULD WARM TO THE MID 80S TO MID
90S...POSSIBLY WARMER.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1149 PM CDT WED JUN 12 2013
LIGHT EASTERLY WINDS WILL SHIFT TO THE SOUTHEAST AND INCREASE ON
THURSDAY AS SURFACE HIGH PRESSURE BUILDS INTO EASTERN NEBRASKA.
MID AND HIGH LEVEL CLOUDINESS WILL BE ON THE INCREASE OVERNIGHT
TONIGHT INTO THURSDAY MORNING AS A WEAK DISTURBANCE TRACKS ACROSS
NEBRASKA. BY THURSDAY AFTERNOON...A STRONGER DISTURBANCE WILL
TRACK EAST OF THE CENTRAL ROCKIES...AND MAY LEAD TO THUNDERSTORMS
ACROSS SOUTHWESTERN NEBRASKA THURSDAY EVENING. WILL HANDLE THE
TSRA MENTION WITH A PROB30 GROUP FOR THE KLBF TERMINAL FROM 00Z
TO 06Z FRIDAY.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JWS
SHORT TERM...JWS
LONG TERM...MASEK
AVIATION...CLB
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1134 PM MDT WED JUN 12 2013
.AVIATION...
06Z TAF CYCLE
VFR CONDITIONS FORECAST TO PERSIST THROUGH THE TAF
PERIOD...EXCEPT FOR SOME BRIEF MVFR CIGS/VSBYS IN AND NEAR
ISOLATED SHOWERS OR THUNDERSTORMS THURSDAY AFTERNOON AND EVENING.
DOWNBURST WINDS ARE AT/NEAR KABQ...KSAF AND KLVS THURSDAY
EVENING...AS ARE WET RUNWAYS. A MODERATE SOUTHERLY LOW LEVEL FLOW
WILL DEVELOP EAST OF THE CENTRAL MOUNTAIN CHAIN THURSDAY
AFTERNOON...BUT SURFACE WIND GUSTS ARE FORECAST TO REMAIN AT OR
BELOW 28KTS.
11
&&
.PREV DISCUSSION...933 PM MDT WED JUN 12 2013...
INCREASED POPS FOR LATE EVENING CONVECTION...ESPECIALLY IN THE
PECOS CANYON AREA FROM GLORIETA TO COWLES EWD GIVEN THE SCT
CONVECTION SPROUTING UP RAPIDLY OVER AND NEAR THE TRES LAGUNAS
FIRE. ALSO INTRODUCED ISOLATED SHOWERS AND THUNDERSTORMS IN THE
SANDIA AND MANZANO MTNS ZONE WEST INTO THE MIDDLE RIO GRANDE
VALLEY WHERE AN OUTFLOW BOUNDARY FROM EARLIER CONVECTION OVER
TORRANCE COUNTY CONTINUES TO SHOW SINGS OF PRODUCING A STORM OR
TWO OVER THE NEXT COUPLE OF HOURS AS DEWPOINTS RISE RAPIDLY AND
WINDS BECOME E-SE.
33
.PREV DISCUSSION...314 PM MDT WED JUN 12 2013...
NOT TOO MUCH CHANGE TO THE GOING FORECAST. TEMPERATURES CONTINUE TO
CREEP UP THIS AFTERNOON AREAWIDE. TEMPS ARE NOT AS QUICK TO RISE
TODAY THANKS TO A LITTLE CLOUD COVER ACROSS THE WEST AND NORTH AND
EAST TO SOUTHEASTERLY SURFACE WINDS ACROSS THE PLAINS. SATELLITE
IMAGERY SHOWING A NICE BUBBLING OF CU EXTENDING FROM THE SANGRE DE
CRISTOS SOUTHWARD TO THE SACRAMENTO MOUNTAINS. THIS WILL BE THE
FAVORED AREA FOR ANY LIGHT SHOWERS...VIRGA AND/OR DRY THUNDERSTORMS
THIS EVENING...THOUGH THE HRRR AND THE NAM WERE SHOWING A BIT OF QPF
ACROSS THE FAR NORTHEAST WHERE SOUTHEASTERLY FLOW IS CURRENTLY
BRINGING HIGHER DEWPOINTS UP ONTO THE RATON RIDGE. ANY ACTIVITY THAT
DEVELOPS SHOULD DIMINISH BY MIDNIGHT...IF NOT SHORTLY AFTER SUNSET.
ANOTHER WARM NIGHT IS IN STORE ACROSS THE EASTERN PLAINS. RECORD
HEAT FOR THURSDAY IS NOT EXPECTED TO BE AS WIDESPREAD. THE
COMBINATION OF AN UPPER LEVEL TROUGH ACROSS THE NORTHWEST CONUS AND
AND UPPER LEVEL DISTURBANCE MOVING NORTHWARD ACROSS MEXICO WILL
RESULT IN THE UPPER LEVEL HIGH SHIFTING EAST. FORECAST SOUNDINGS
CONTINUE TO SHOW STRONG INVERTED-V SIGNATURES UP TO ROUGHLY 500 MB
SUGGESTING CONTINUED POTENTIAL OF MOSTLY DRY THUNDERSTORMS ACROSS
THE WEST AND NORTHWEST PORTIONS OF THE CWA. FURTHER EAST...A POCKET
OF DRY AIR AHEAD OF THE APPROACHING DISTURBANCE FROM THE SOUTH WILL
LIMIT SHOWER AND T-STORM POTENTIAL...AT LEAST THROUGH MUCH OF THE
DAY. IF THE GFS VERIFIES...SOME CHANCE WILL EXIST IN THE
EVENING...BUT AT THIS POINT...NOT AS CONFIDENT ABOUT THAT.
THOUGH THE UPPER LOW WILL TRACK OVER SE NM AND WEST TEXAS...SELY
FLOW WILL BRING BETTER MOISTURE BACK TO THE CENTRAL MOUNTAIN CHAIN
AND PERHAPS INTO THE RIO GRANDE VALLEY THURSDAY NIGHT INTO FRIDAY
MORNING. BETWEEN THE ADDED MOISTURE..PERHAPS A SLIGHT COOLING AT
MID LEVELS...AND SOME WEAK CONVERGENCE AT MID LEVELS BETWEEN THE
SELY FLOW ACROSS THE EAST AS A RESULT OF THE LOW...AND WSW FLOW AT
MID LEVELS ACROSS THE WEST FOLLOWING THE PASSAGE OF THE NW
TROUGH...CENTRAL PORTIONS OF THE STATE WILL BE THE FAVORED AREA
FOR PRECIPITATION ON FRIDAY. THOUGH AMOUNTS WILL LIKELY BE
MODEST...WITH FEW EXCEPTIONS...THERE IS A BETTER CHANCE OF
MEASURABLE RAINFALL THAN WE HAVE SEEN IN A WHILE. HOWEVER...A
CHANCE FOR DRY THUNDERSTORMS REMAINS ACROSS WESTERN AREAS...ON THE
FRINGES OF THE BETTER MOISTURE. THE OTHER GOOD NEWS IS...WITH THE
ADDED CLOUD COVER AND PRECIPITATION... TEMPERATURES WILL TREND
DOWN TO NEAR NORMAL VALUES.
MOISTURE WILL RECYCLE IN THE FORM OF SHOWERS AND THUNDERSTORMS ON
SATURDAY AS THE UPPER LEVEL LOW SLOWLY DEPARTS WEST TEXAS. THEN MORE
WEST OR SOUTHWESTERLY FLOW LOOKS TO TAKE SHAPE ON SUNDAY...AND
MOISTURE ONCE AGAIN PLUMMETS. TEMPS WILL ALSO JUMP BACK UP A FEW
DEGREES. MODELS CONTINUE TO WAVER ON A BACK DOOR COLD FRONT ON
MONDAY AND THE ASSOCIATED MOISTURE IT MAY OR MAY NOT BRING TO THE
EAST. AFTER WHICH...HOWEVER...IT APPEARS A DRIER SOUTHWESTERLY FLOW
WILL BE THE RULE THROUGH MID WEEK AS THE UPPER HIGH RE-ESTABLISHES
ITSELF OVER TEXAS.
34
.FIRE WEATHER...
ELONGATED UPPER LEVEL RIDGE OVER THE AREA WILL GRADUALLY WEAKEN AND
SHIFT EASTWARD THROUGH FRIDAY. AT THE SAME TIME...A TROPICAL
DISTURBANCE CURRENTLY OVER CENTRAL MEXICO WILL SLOWLY DRIFT
NORTHWARD INITIALLY BEFORE FOLLOWING A MORE NELY TRAJECTORY BY
WEEK/S END. THIS LARGE-SCALE PATTERN SHIFT WILL BRING A TEMPORARY
END TO OUR RECORD-SETTING HEAT AS WELL AS A RATHER SIGNIFICANT
INCREASE IN THUNDERSTORM ACTIVITY EAST OF THE DIVIDE BY FRIDAY AND
FRIDAY EVENING. UNFORTUNATELY...THE THREAT OF DRY LIGHTNING WILL BE
A CONCERN FOR MANY AREAS TOMORROW BUT A TREND TOWARD WETTER STORMS
IS EXPECTED BY FRIDAY ESPECIALLY FOR AREAS NEAR THE CENTRAL MOUNTAIN
CHAIN.
THERE WILL STILL BE A PRONOUNCED WESTWARD EXTENSION OF THE RIDGE
OVER THE AREA ON THURSDAY BUT THE SUBTLE EASTWARD SHIFT OF THE
PRIMARY HIGH CENTER WILL ALLOW FOR SLIGHT COOLING ALOFT THAT COMBINED
WITH A GRADUAL MOISTENING OF THE LOWER ATMOSPHERE FROM THE
MID-LEVELS DOWN WILL RESULT IN A THREAT FOR ISOLATED DRY
THUNDERSTORMS OVER THE HIGHER TERRAIN OF THE WEST ON THURSDAY WITH A
TREND TOWARD ISOLATED MIXED WET/DRY STORMS ALONG AND IMMEDIATELY
EAST OF THE CENTRAL MOUNTAIN CHAIN. THE OTHER CONCERN ON THURSDAY
WILL BE INCREASING SOUTH-SOUTHWEST WINDS ACROSS THE NORTHEAST
QUARTER. DEW POINTS WILL BE ON THE INCREASE HERE BUT WITH A
SLIGHTLY DOWNSLOPE COMPONENT HAVE TRENDED DRIER THAN THE GFS BUT
SLIGHTLY ABOVE THE NAM THAT IS BY FAR THE DRIEST. THE END RESULT
COULD BE SEVERAL HOURS OF CRITICAL FIRE WEATHER CONDITIONS ACROSS
THE NORTHEAST PLAINS. DO HAVE SOME CONCERN FOR A COUPLE HOURS OF RED
FLAG CONDITIONS ACROSS EASTERN PORTIONS OF ZONE 103-- ALONG AND EAST
OF THE INTERSTATE 25 CORRIDOR. LEFT THIS AREA OUT OF THE RED FLAG
WARNING GIVEN LIMITED IMPACT.
HUMIDITY RECOVERY TONIGHT WILL NOT BE NEAR AS BRUTAL AS THE PAST TWO
NIGHTS BUT STILL FAIR TO POOR FOR WESTERN AREAS AND THE HIGHEST
TERRAIN OF THE NORTH. MIN RH VALUES ON THURSDAY WILL BE TRENDING
UPWARD WITH SINGLE DIGIT READINGS CONFINED TO LOWER ELEVATIONS WEST
OF THE DIVIDE.
THE ABOVE MENTIONED TROPICAL LOW SHOULD BE PASSING OVER OR VERY
NEAR SOUTHEAST NEW MEXICO FRIDAY NIGHT....THOUGH MODELS DIFFER
WHEN IT MAKES ITS TURN TO THE NORTHEAST. TRENDED DEW POINTS UPWARD
CENTRAL AND ESPECIALLY EASTERN AREAS AND COULD SEE DECENT WETTING
RAIN POTENTIAL AT NIGHT ACROSS PARTS OF THE EC/SE PLAINS NEARER
THE LOW/S CORE. OTHERWISE...FRIDAY EVENING LOOKS TO BE AMONG THE
MORE ACTIVE PERIODS OF THUNDERSTORM ACTIVITY THIS FORECAST CYCLE.
THE UPPER HIGH WILL RESTRENGTHEN OVER THE AREA AS THE WEEKEND
PROGRESSES WITH DRIER AIR BECOMING PREDOMINATE. THIS SHOULD ALLOW
WARMER THAN AVERAGE DAYTIME TEMPERATURES TO RETURN ALONG WITH LOWER
HUMIDITIES ESPECIALLY CENTRAL AND WEST.
KJ
.AVIATION...
18Z TAF CYCLE
VFR CONDITIONS WILL PREDOMINATE THROUGH AT LEAST 12Z THU. MODERATE
SFC WINDS WILL OCCASIONALLY GUST TO 20-25 KTS BUT SPEEDS WILL BE
LESS THAN YESTERDAY. HIGHEST CONFIDENCE IN SURFACE SMOKE IMPACTS
TO KSAF LATER TONIGHT WITH SMOKE LAYERS ALOFT JUST ABOUT ANYWHERE
WITH TRANSPORT WINDS GENERALLY FROM SW TO NE. ISOLATED HIGH BASED
-SHRA AND -TSRA ACROSS MAINLY THE CENTRAL MT CHAIN AND THE ADJACENT
HIGHLANDS IMMEDIATELY TO THE EAST BETWEEN ROUGHLY 20Z AND 04Z.
LOCALIZED GUSTY WINDS THE MAIN CONCERN WITH THIS ACTIVITY. KJ
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM 2 PM TO 8 PM MDT THURSDAY FOR THE FOLLOWING
ZONES...NMZ104.
&&
$$
33
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
247 PM EDT THU JUN 13 2013
.SYNOPSIS...
A STORM SYSTEM WILL TRACK THROUGH PENNSYLVANIA TO THE ATLANTIC
SEABOARD TODAY. THIS STORM WILL SPREAD A SOAKING RAIN INTO NEW
YORK AND PENNSYLVANIA, POTENTIALLY BRINGING SMALL STREAM AND MINOR
RIVER FLOODING TO PORTIONS OF THE REGION. AFTER THIS SYSTEM MOVES
EAST LATE TONIGHT, HIGH PRESSURE WILL BRING CLEARING SKIES AND
WARMING TEMPERATURES TO THE AREA EARLY IN THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
225 PM UPDATE...
CONTINUING ALONG WITH RADAR TRENDS, NOW CONFIRMED BY RAP, WE HAVE
OPTED TO DROP THE FLOOD WATCH FOR ALL AREAS SAVE FOR THE FAR
EASTERN FA. FRONTOGENESIS WILL BE BEST FROM OTSEGO/DELAWARE COUNTY
EASTWARD, BUT THE WINDOW OF OPPORTUNITY FOR MODERATE RAIN WILL
RAPIDLY CLOSE AFTER 22Z.
THE MOST INTERESTING ASPECT OF THE WX TO WATCH FROM THIS POINT
FORTH MAY BE CONVECTION FIRING IN THE SLIGHTLY MORE UNSTABLE AIR
FROM THE WYOMING VALLEY EASTWARD. ANY STORMS WHICH FIRE WILL BE
VERY EFFICIENT RAIN PRODUCERS, THOUGH ACTIVITY WILL BE QUITE
LIMITED.
SCATTERED SHOWERS WILL CONTINUE OVERNIGHT UNDER INFLUENCE OF UPPER
VORTEX.
105 PM UPDATE...
LATEST RAP NOW SHOOTS THE 700MB FRONTOGENESIS OFF TO THE
NORTHEAST, WHICH IS IN AGREEMENT WITH OBSERVED RADAR TRENDS. WITH
THIS IN MIND, WE HAVE DROPPED THE SOUTHWESTERN SECTION OF THE
FLOOD WATCH.
1205 PM UPDATE...
RAP REMAINS INSISTENT THAT AREA OF MODERATE PRECIP WILL SHIFT
SOUTHWARD TOWARD CHENANGO AND DELAWARE COUNTIES OVER THE NEXT
HOUR, AND INTENSIFY OVER THIS AREA OVER THE NEXT 3-4 HOURS. MODELS
HAVE PERFORMED QUITE POORLY WITH BOTH THE QPF AND FRONTOGENESIS
FIELDS SO FAR, SO IT IS NATURAL TO HAVE A HEALTHY DOSE OF
SKEPTICISM. HOWEVER WE ARE CLOSELY MONITORING RADAR/SAT TRENDS FOR
A SHIFT IN THE PRECIP AXIS.
WILL BE ASSESSING FLOOD WATCH FOR SOUTHWESTERN FA IN THE NEXT FEW
HOURS.
945 AM UPDATE...
MORNING THREAT FOR SEVERE THUNDERSTORMS OVER FAR SOUTHERN FA HAS
PASSED, SO WE HAVE CANCELLED THE WATCH FOR LUZERNE CO.
THIS MORNING...A GENERAL QUARTER TO HALF INCH OF RAIN HAS BEEN
OBSERVED TO THIS POINT, WITH AROUND A HALF INCH TO 1 INCH EXPECTED
TO HAVE ACCUMULATED BY EARLY AFTERNOON.
IMPRESSIVE DRY SLOT DEVELOPED EARLIER AND WILL HAVE A LARGE EFFECT
ON OUR POPS/QPF THROUGH EARLY AFTERNOON. MESOSCALE MODELS TRY TO
FILL IN THE DRY SLOT BETWEEN 1 PM AND 4 PM, IN ADVANCE OF 700MB
LOW AND RELATED FRONTOGENESIS AHEAD OF IT. MODEL PROJECTIONS WOULD
BRING THIS FAVORABLE AREA SOUTHEAST TOWARD THE TWIN TIERS DURING
THE AFTERNOON...AND THEN INTO THE EASTERN FA FOR LATE AFTERNOON
AND EARLY EVENING.
WE ARE PLAYING THE 700MB LOW / FRONTOGENESIS AS THE AREA WHERE
PRECIP WILL INCREASE FOR THE AFTERNOON INTO EARLY EVENING. TOTAL
STORM QPF VALUES WILL RANGE FROM 1 TO 2 INCHES, WITH HIGHER
AMOUNTS POSSIBLE ESPECIALLY OVER EASTERN FA WHERE LOW HANGS UP
LATE IN THE DAY.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
QUIET WEATHER RETURNS FRIDAY THROUGH SATURDAY. ISOLATED SHOWERS
STILL POSSIBLE FRIDAY MORNING INTO THE AFTERNOON AS THE UPPER
TROUGH MOVES EAST OFF THE EAST COAST AND A LITTLE MOISTURE AND
INSTABILITY LINGERS INTO MID AFTERNOON. HIGH PRESSURE BUILDS EAST
ACROSS THE AREA FRIDAY NIGHT AND SATURDAY WITH DRY SEASONABLY MILD
WEATHER EXPECTED.
NEXT CHANCE OF SHOWERS AND THUNDERSTORMS WILL BE SUNDAY AS THE
NEXT SHORT WAVE TROUGH APPROACHES FROM THE WEST ALONG WITH A
DEVELOPING WAA PATTERN. INSTABILITY INCREASES WITH MODELS
GENERALLY INDICATING AROUND 400-800 J/KG BY SUNDAY AFTERNOON
ACROSS THE FINGER LAKES... WITH LESS TO THE EAST. BASED ON THIS
SCENARIO HAVE GONE WITH CHC POPS FOR SHOWERS AND THUNDERSTORMS ON
SUNDAY WITH HIGHEST CHANCES IN THE WEST.
USED A MODEL BLEND WITH THE PREVIOUS FORECAST FOR TEMPERATURES...
HIGHS GENERALLY NEAR 70 ON FRIDAY... INTO THE MID 70S ON
SATURDAY... AND MID TO UPPER 70S ON SUNDAY.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
GENERAL AGREEMENT BETWEEN THE GFS AND THE LATEST 12Z ECMWF IS
INDICATED ON THE OVERALL PATTERN EARLY NEXT WEEK... HOWEVER SOME
DIFFERENCES IN TIMING ARE SEEN. BOTH MODELS INDICATE A COLD FRONT
APPROACHING THE AREA ON MONDAY WITH A CHANCE OF SHOWERS AND
THUNDERSTORMS. COMBINATION OF INCREASING INSTABILITY AND
MODERATELY STRONG WIND FIELDS COULD LEAD TO A SEVERE WEATHER RISK
MONDAY AFTERNOON AND THIS WILL BE MONITORED. THE LATEST GFS IS
SLOWER AND DEEPER WITH THE APPROACHING TROUGH... LEADING TO A CHC
OF SHOWESR AND STORMS CONTINUING ON TUESDAY... WHILE THE ECMWF
INDICATES THAT THE TROUGH PASSES EAST OF THE AREA EARLY TUESDAY.
WILL KEEP A CHANCE OF SHOWERS ON TUESDAY... BUT A LOWER CHANCE
THAN ON MONDAY. HIGH PRESSURE WILL BUILD ACROSS THE AREA WITH DRY
MILD WEATHER WEDNESDAY INTO THURSDAY.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
1 PM UPDATE...
LOW PRESSURE WILL TRACK ACROSS THE AREA THIS AFTERNOON WITH
SHOWERS AND MOSTLY MVFR CONDITIONS WITH AREAS OF IFR CIGS AND
LOCALIZED IFR VSBYS IN ANY HEAVIER SHOWERS. SHOWERS WILL END THIS
EVENING FOLLOWED BY MOSTLY CLOUDY WEATHER OVERNIGHT WITH MAINLY
MVFR CIGS. CONDITIONS WILL GRADUALLY IMPROVE ON FRIDAY WITH MOSTLY
VFR BY AFTERNOON.
WINDS WILL BE EAST AT 5 TO 15 KTS TODAY SHIFTING TO NORTH AT 10
KTS OR LESS TONIGHT THEN NORTHWEST AT 10 TO 15 KTS ON FRIDAY.
OUTLOOK...
FRI...IMPRVNG TO VFR.
FRI NGT/SAT/SAT NGT...VFR BUT POTENTIAL VALLEY FOG SAT AM AT ELM.
SUN TO MON...MAINLY VFR...BUT MVFR IN SHRA/TSRA.
&&
.HYDROLOGY...
POSSIBLE RIVER AND FLASH FLOODING TODAY INTO FRIDAY. 1 TO 3 INCHES
AND MAYBE MORE. STILL QUESTIONS ON PLACEMENT OF HEAVIEST RAIN.
MOST MODELS HAVE IT IN THE SRN TIER TO CATSKILLS OF NY WHILE THE
EURO AND WPC IS FURTHER SOUTH IN THE NRN TIER OF NE PA. BOTH WAYS
FINGER LAKES TO MOHAWK VALLEY AROUND AN INCH AND NOT IN THE FLOOD
WATCH. WITH HIGH PWATS AND TSTMS RAINFALL RATES COULD EXCEED AN
INCH AN HOUR FOR SHORT PERIODS. 2 INCHES WILL START TO CAUSE
PROBLEMS AND 3 AND MORE WILL BE WORSE. NOT EXPECTING WIDESPREAD 3
PLUS SO RIVER FLOODING WILL ONLY BE MINOR. FOR NOW SUSQUEHANNA
RIVER AT VESTAL AND WAVERLY/SAYRE ARE FORECAST TO HAVE MINOR
FLOODING. WALTON ON THE WEST BRANCH DELAWARE WILL GET CLOSE.
HEADWATERS AT CORTLAND AND SHERBURNE NOT IN THE HEAVY RAIN AXIS
BUT IF IT SETS UP 50 MILES FURTHER NORTH THESE POINTS WILL FLOOD.
FOR NOW RIVER FLOODING EXPECTED FRIDAY SO NO WARNINGS ISSUED UNTIL
RAIN COMES IN AND CONFIDENCE INCREASES.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...FLOOD WATCH THROUGH FRIDAY MORNING FOR NYZ045-046-057-062.
&&
$$
SYNOPSIS...DJP
NEAR TERM...DJP
SHORT TERM...MSE
LONG TERM...MSE
AVIATION...MSE
HYDROLOGY...
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
226 PM EDT THU JUN 13 2013
.SYNOPSIS...
A STORM SYSTEM WILL TRACK THROUGH PENNSYLVANIA TO THE ATLANTIC
SEABOARD TODAY. THIS STORM WILL SPREAD A SOAKING RAIN INTO NEW
YORK AND PENNSYLVANIA, POTENTIALLY BRINGING SMALL STREAM AND MINOR
RIVER FLOODING TO PORTIONS OF THE REGION. AFTER THIS SYSTEM MOVES
EAST LATE TONIGHT, HIGH PRESSURE WILL BRING CLEARING SKIES AND
WARMING TEMPERATURES TO THE AREA EARLY IN THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
225 PM UPDATE...
CONTINUING ALONG WITH RADAR TRENDS, NOW CONFIRMED BY RAP, WE HAVE
OPTED TO DROP THE FLOOD WATCH FOR ALL AREAS SAVE FOR THE FAR
EASTERN FA. FRONTOGENESIS WILL BE BEST FROM OTSEGO/DELAWARE COUNTY
EASTWARD, BUT THE WINDOW OF OPPORTUNITY FOR MODERATE RAIN WILL
RAPIDLY CLOSE AFTER 22Z.
THE MOST INTERESTING ASPECT OF THE WX TO WATCH FROM THIS POINT
FORTH MAY BE CONVECTION FIRING IN THE SLIGHTLY MORE UNSTABLE AIR
FROM THE WYOMING VALLEY EASTWARD. ANY STORMS WHICH FIRE WILL BE
VERY EFFICIENT RAIN PRODUCERS, THOUGH ACTIVITY WILL BE QUITE
LIMITED.
SCATTERED SHOWERS WILL CONTINUE OVERNIGHT UNDER INFLUENCE OF UPPER
VORTEX.
105 PM UPDATE...
LATEST RAP NOW SHOOTS THE 700MB FRONTOGENESIS OFF TO THE
NORTHEAST, WHICH IS IN AGREEMENT WITH OBSERVED RADAR TRENDS. WITH
THIS IN MIND, WE HAVE DROPPED THE SOUTHWESTERN SECTION OF THE
FLOOD WATCH.
1205 PM UPDATE...
RAP REMAINS INSISTENT THAT AREA OF MODERATE PRECIP WILL SHIFT
SOUTHWARD TOWARD CHENANGO AND DELAWARE COUNTIES OVER THE NEXT
HOUR, AND INTENSIFY OVER THIS AREA OVER THE NEXT 3-4 HOURS. MODELS
HAVE PERFORMED QUITE POORLY WITH BOTH THE QPF AND FRONTOGENESIS
FIELDS SO FAR, SO IT IS NATURAL TO HAVE A HEALTHY DOSE OF
SKEPTICISM. HOWEVER WE ARE CLOSELY MONITORING RADAR/SAT TRENDS FOR
A SHIFT IN THE PRECIP AXIS.
WILL BE ASSESSING FLOOD WATCH FOR SOUTHWESTERN FA IN THE NEXT FEW
HOURS.
945 AM UPDATE...
MORNING THREAT FOR SEVERE THUNDERSTORMS OVER FAR SOUTHERN FA HAS
PASSED, SO WE HAVE CANCELLED THE WATCH FOR LUZERNE CO.
THIS MORNING...A GENERAL QUARTER TO HALF INCH OF RAIN HAS BEEN
OBSERVED TO THIS POINT, WITH AROUND A HALF INCH TO 1 INCH EXPECTED
TO HAVE ACCUMULATED BY EARLY AFTERNOON.
IMPRESSIVE DRY SLOT DEVELOPED EARLIER AND WILL HAVE A LARGE EFFECT
ON OUR POPS/QPF THROUGH EARLY AFTERNOON. MESOSCALE MODELS TRY TO
FILL IN THE DRY SLOT BETWEEN 1 PM AND 4 PM, IN ADVANCE OF 700MB
LOW AND RELATED FRONTOGENESIS AHEAD OF IT. MODEL PROJECTIONS WOULD
BRING THIS FAVORABLE AREA SOUTHEAST TOWARD THE TWIN TIERS DURING
THE AFTERNOON...AND THEN INTO THE EASTERN FA FOR LATE AFTERNOON
AND EARLY EVENING.
WE ARE PLAYING THE 700MB LOW / FRONTOGENESIS AS THE AREA WHERE
PRECIP WILL INCREASE FOR THE AFTERNOON INTO EARLY EVENING. TOTAL
STORM QPF VALUES WILL RANGE FROM 1 TO 2 INCHES, WITH HIGHER
AMOUNTS POSSIBLE ESPECIALLY OVER EASTERN FA WHERE LOW HANGS UP
LATE IN THE DAY.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
440 AM UPDATE...
SYSTEM PULLS MOISTURE EAST OF THE AREA AFT 06Z TONIGHT. HWVR, WITH
WATER STILL RUNNING OFF, CONCERN AFT THIS POINT WL BE HOW MUCH WL
LOCAL WATERWAYS RISE. IMMEDIATE FLASH FLOODING THREAT WL BE WINDING
DOWN LATE TONIGHT AS HEAVIEST PCPN COMES TO AN END.
ANOTHER CHC FOR SHOWERS WL MV INTO AREA ON FRIDAY AS A SFC BNDRY
FOLLOWS IN FM CANADA IN ADVANCE OF 1020MB HIPRES BUILDING IN. WITH
TEMPS PROGGED TO WARM INTO THE LWR 70S AND COOLING TEMPS ALOFT,
POTENTIAL WL EXIST FOR ISOLD THUNDER DRG THE AFTN.
HIPRES BUILDS IN FRI NGT BRINGING CLRNG SKIES AND TEMPS DROPPING
INTO THE 40S SATURDAY MRNG. AFN HIGHS ON SATURDAY PROGGED TO RISE
CLOSER TO NORMAL VALUES. NEXT SYSTEM PROGGED TO APPCH AFT THE SHORT
TERM PD.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
2 AM UPDATE...
LITTLE CHANGE. AGAIN FOLLOWED WPC GUIDANCE. UNSETTLED TO START
WITH MULTIPLE WEAK SYSTEMS GOING THROUGH THE REGION LATE SUNDAY TO
TUESDAY. HIGH PRESSURE WED TO THU. TEMPERATURES CLOSE TO AVERAGE.
PREVIOUS DISCUSSION...
UTILIZED WPC MED RNG GUIDANCE. LTL CHG TO CRNT FCST WITH HI PRES
RDG MOVG OFF THE EAST CST SAT NGT. A SERIES OF S/WV`S EMBEDDED
WITHIN THE WNW FLOW ALOFT WILL KEEP A CHC FOR SHRA/TSRA IN THE
FCST UNTIL TUE...WHEN THE LAST OF THESE SYSTEMS IS XPCTD TO PASS.
LARGE AREA OF HI PRES FOLLOWS FOR NXT TUE NGT AND WED.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
1 PM UPDATE...
LOW PRESSURE WILL TRACK ACROSS THE AREA THIS AFTERNOON WITH
SHOWERS AND MOSTLY MVFR CONDITIONS WITH AREAS OF IFR CIGS AND
LOCALIZED IFR VSBYS IN ANY HEAVIER SHOWERS. SHOWERS WILL END THIS
EVENING FOLLOWED BY MOSTLY CLOUDY WEATHER OVERNIGHT WITH MAINLY
MVFR CIGS. CONDITIONS WILL GRADUALLY IMPROVE ON FRIDAY WITH MOSTLY
VFR BY AFTERNOON.
WINDS WILL BE EAST AT 5 TO 15 KTS TODAY SHIFTING TO NORTH AT 10
KTS OR LESS TONIGHT THEN NORTHWEST AT 10 TO 15 KTS ON FRIDAY.
OUTLOOK...
FRI...IMPRVNG TO VFR.
FRI NGT/SAT/SAT NGT...VFR BUT POTENTIAL VALLEY FOG SAT AM AT ELM.
SUN TO MON...MAINLY VFR...BUT MVFR IN SHRA/TSRA.
&&
.HYDROLOGY...
POSSIBLE RIVER AND FLASH FLOODING TODAY INTO FRIDAY. 1 TO 3 INCHES
AND MAYBE MORE. STILL QUESTIONS ON PLACEMENT OF HEAVIEST RAIN.
MOST MODELS HAVE IT IN THE SRN TIER TO CATSKILLS OF NY WHILE THE
EURO AND WPC IS FURTHER SOUTH IN THE NRN TIER OF NE PA. BOTH WAYS
FINGER LAKES TO MOHAWK VALLEY AROUND AN INCH AND NOT IN THE FLOOD
WATCH. WITH HIGH PWATS AND TSTMS RAINFALL RATES COULD EXCEED AN
INCH AN HOUR FOR SHORT PERIODS. 2 INCHES WILL START TO CAUSE
PROBLEMS AND 3 AND MORE WILL BE WORSE. NOT EXPECTING WIDESPREAD 3
PLUS SO RIVER FLOODING WILL ONLY BE MINOR. FOR NOW SUSQUEHANNA
RIVER AT VESTAL AND WAVERLY/SAYRE ARE FORECAST TO HAVE MINOR
FLOODING. WALTON ON THE WEST BRANCH DELAWARE WILL GET CLOSE.
HEADWATERS AT CORTLAND AND SHERBURNE NOT IN THE HEAVY RAIN AXIS
BUT IF IT SETS UP 50 MILES FURTHER NORTH THESE POINTS WILL FLOOD.
FOR NOW RIVER FLOODING EXPECTED FRIDAY SO NO WARNINGS ISSUED UNTIL
RAIN COMES IN AND CONFIDENCE INCREASES.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...FLOOD WATCH THROUGH FRIDAY MORNING FOR NYZ045-046-057-062.
&&
$$
SYNOPSIS...DJP
NEAR TERM...DJP
SHORT TERM...PVN
LONG TERM...TAC
AVIATION...MSE
HYDROLOGY...
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
142 PM EDT THU JUN 13 2013
.SYNOPSIS...
A STORM SYSTEM WILL TRACK THROUGH PENNSYLVANIA TO THE ATLANTIC
SEABOARD TODAY. THIS STORM WILL SPREAD A SOAKING RAIN INTO NEW
YORK AND PENNSYLVANIA, POTENTIALLY BRINGING SMALL STREAM AND MINOR
RIVER FLOODING TO PORTIONS OF THE REGION. AFTER THIS SYSTEM MOVES
EAST LATE TONIGHT, HIGH PRESSURE WILL BRING CLEARING SKIES AND
WARMING TEMPERATURES TO THE AREA EARLY IN THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
105 PM UPDATE...
LATEST RAP NOW SHOOTS THE 700MB FRONTOGENESIS OFF TO THE
NORTHEAST, WHICH IS IN AGREEMENT WITH OBSERVED RADAR TRENDS. WITH
THIS IN MIND, WE HAVE DROPPED THE SOUTHWESTERN SECTION OF THE
FLOOD WATCH.
1205 PM UPDATE...
RAP REMAINS INSISTENT THAT AREA OF MODERATE PRECIP WILL SHIFT
SOUTHWARD TOWARD CHENANGO AND DELAWARE COUNTIES OVER THE NEXT
HOUR, AND INTENSIFY OVER THIS AREA OVER THE NEXT 3-4 HOURS. MODELS
HAVE PERFORMED QUITE POORLY WITH BOTH THE QPF AND FRONTOGENESIS
FIELDS SO FAR, SO IT IS NATURAL TO HAVE A HEALTHY DOSE OF
SKEPTICISM. HOWEVER WE ARE CLOSELY MONITORING RADAR/SAT TRENDS FOR
A SHIFT IN THE PRECIP AXIS.
WILL BE ASSESSING FLOOD WATCH FOR SOUTHWESTERN FA IN THE NEXT FEW
HOURS.
945 AM UPDATE...
MORNING THREAT FOR SEVERE THUNDERSTORMS OVER FAR SOUTHERN FA HAS
PASSED, SO WE HAVE CANCELLED THE WATCH FOR LUZERNE CO.
THIS MORNING...A GENERAL QUARTER TO HALF INCH OF RAIN HAS BEEN
OBSERVED TO THIS POINT, WITH AROUND A HALF INCH TO 1 INCH EXPECTED
TO HAVE ACCUMULATED BY EARLY AFTERNOON.
IMPRESSIVE DRY SLOT DEVELOPED EARLIER AND WILL HAVE A LARGE EFFECT
ON OUR POPS/QPF THROUGH EARLY AFTERNOON. MESOSCALE MODELS TRY TO
FILL IN THE DRY SLOT BETWEEN 1 PM AND 4 PM, IN ADVANCE OF 700MB
LOW AND RELATED FRONTOGENESIS AHEAD OF IT. MODEL PROJECTIONS WOULD
BRING THIS FAVORABLE AREA SOUTHEAST TOWARD THE TWIN TIERS DURING
THE AFTERNOON...AND THEN INTO THE EASTERN FA FOR LATE AFTERNOON
AND EARLY EVENING.
WE ARE PLAYING THE 700MB LOW / FRONTOGENESIS AS THE AREA WHERE
PRECIP WILL INCREASE FOR THE AFTERNOON INTO EARLY EVENING. TOTAL
STORM QPF VALUES WILL RANGE FROM 1 TO 2 INCHES, WITH HIGHER
AMOUNTS POSSIBLE ESPECIALLY OVER EASTERN FA WHERE LOW HANGS UP
LATE IN THE DAY.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
440 AM UPDATE...
SYSTEM PULLS MOISTURE EAST OF THE AREA AFT 06Z TONIGHT. HWVR, WITH
WATER STILL RUNNING OFF, CONCERN AFT THIS POINT WL BE HOW MUCH WL
LOCAL WATERWAYS RISE. IMMEDIATE FLASH FLOODING THREAT WL BE WINDING
DOWN LATE TONIGHT AS HEAVIEST PCPN COMES TO AN END.
ANOTHER CHC FOR SHOWERS WL MV INTO AREA ON FRIDAY AS A SFC BNDRY
FOLLOWS IN FM CANADA IN ADVANCE OF 1020MB HIPRES BUILDING IN. WITH
TEMPS PROGGED TO WARM INTO THE LWR 70S AND COOLING TEMPS ALOFT,
POTENTIAL WL EXIST FOR ISOLD THUNDER DRG THE AFTN.
HIPRES BUILDS IN FRI NGT BRINGING CLRNG SKIES AND TEMPS DROPPING
INTO THE 40S SATURDAY MRNG. AFN HIGHS ON SATURDAY PROGGED TO RISE
CLOSER TO NORMAL VALUES. NEXT SYSTEM PROGGED TO APPCH AFT THE SHORT
TERM PD.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
2 AM UPDATE...
LITTLE CHANGE. AGAIN FOLLOWED WPC GUIDANCE. UNSETTLED TO START
WITH MULTIPLE WEAK SYSTEMS GOING THROUGH THE REGION LATE SUNDAY TO
TUESDAY. HIGH PRESSURE WED TO THU. TEMPERATURES CLOSE TO AVERAGE.
PREVIOUS DISCUSSION...
UTILIZED WPC MED RNG GUIDANCE. LTL CHG TO CRNT FCST WITH HI PRES
RDG MOVG OFF THE EAST CST SAT NGT. A SERIES OF S/WV`S EMBEDDED
WITHIN THE WNW FLOW ALOFT WILL KEEP A CHC FOR SHRA/TSRA IN THE
FCST UNTIL TUE...WHEN THE LAST OF THESE SYSTEMS IS XPCTD TO PASS.
LARGE AREA OF HI PRES FOLLOWS FOR NXT TUE NGT AND WED.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
1 PM UPDATE...
LOW PRESSURE WILL TRACK ACROSS THE AREA THIS AFTERNOON WITH
SHOWERS AND MOSTLY MVFR CONDITIONS WITH AREAS OF IFR CIGS AND
LOCALIZED IFR VSBYS IN ANY HEAVIER SHOWERS. SHOWERS WILL END THIS
EVENING FOLLOWED BY MOSTLY CLOUDY WEATHER OVERNIGHT WITH MAINLY
MVFR CIGS. CONDITIONS WILL GRADUALLY IMPROVE ON FRIDAY WITH MOSTLY
VFR BY AFTERNOON.
WINDS WILL BE EAST AT 5 TO 15 KTS TODAY SHIFTING TO NORTH AT 10
KTS OR LESS TONIGHT THEN NORTHWEST AT 10 TO 15 KTS ON FRIDAY.
OUTLOOK...
FRI...IMPRVNG TO VFR.
FRI NGT/SAT/SAT NGT...VFR BUT POTENTIAL VALLEY FOG SAT AM AT ELM.
SUN TO MON...MAINLY VFR...BUT MVFR IN SHRA/TSRA.
&&
.HYDROLOGY...
POSSIBLE RIVER AND FLASH FLOODING TODAY INTO FRIDAY. 1 TO 3 INCHES
AND MAYBE MORE. STILL QUESTIONS ON PLACEMENT OF HEAVIEST RAIN.
MOST MODELS HAVE IT IN THE SRN TIER TO CATSKILLS OF NY WHILE THE
EURO AND WPC IS FURTHER SOUTH IN THE NRN TIER OF NE PA. BOTH WAYS
FINGER LAKES TO MOHAWK VALLEY AROUND AN INCH AND NOT IN THE FLOOD
WATCH. WITH HIGH PWATS AND TSTMS RAINFALL RATES COULD EXCEED AN
INCH AN HOUR FOR SHORT PERIODS. 2 INCHES WILL START TO CAUSE
PROBLEMS AND 3 AND MORE WILL BE WORSE. NOT EXPECTING WIDESPREAD 3
PLUS SO RIVER FLOODING WILL ONLY BE MINOR. FOR NOW SUSQUEHANNA
RIVER AT VESTAL AND WAVERLY/SAYRE ARE FORECAST TO HAVE MINOR
FLOODING. WALTON ON THE WEST BRANCH DELAWARE WILL GET CLOSE.
HEADWATERS AT CORTLAND AND SHERBURNE NOT IN THE HEAVY RAIN AXIS
BUT IF IT SETS UP 50 MILES FURTHER NORTH THESE POINTS WILL FLOOD.
FOR NOW RIVER FLOODING EXPECTED FRIDAY SO NO WARNINGS ISSUED UNTIL
RAIN COMES IN AND CONFIDENCE INCREASES.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...FLOOD WATCH THROUGH FRIDAY MORNING FOR PAZ040-048-072.
NY...FLOOD WATCH THROUGH FRIDAY MORNING FOR NYZ025-044>046-056-057-
062.
&&
$$
SYNOPSIS...DJP
NEAR TERM...DJP
SHORT TERM...PVN
LONG TERM...TAC
AVIATION...MSE
HYDROLOGY...
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
107 PM EDT THU JUN 13 2013
.SYNOPSIS...
A STORM SYSTEM WILL TRACK THROUGH PENNSYLVANIA TO THE ATLANTIC
SEABOARD TODAY. THIS STORM WILL SPREAD A SOAKING RAIN INTO NEW
YORK AND PENNSYLVANIA, POTENTIALLY BRINGING SMALL STREAM AND MINOR
RIVER FLOODING TO PORTIONS OF THE REGION. AFTER THIS SYSTEM MOVES
EAST LATE TONIGHT, HIGH PRESSURE WILL BRING CLEARING SKIES AND
WARMING TEMPERATURES TO THE AREA EARLY IN THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
105 PM UPDATE...
LATEST RAP NOW SHOOTS THE 700MB FRONTOGENESIS OFF TO THE
NORTHEAST, WHICH IS IN AGREEMENT WITH OBSERVED RADAR TRENDS. WITH
THIS IN MIND, WE HAVE DROPPED THE SOUTHWESTERN SECTION OF THE
FLOOD WATCH.
1205 PM UPDATE...
RAP REMAINS INSISTENT THAT AREA OF MODERATE PRECIP WILL SHIFT
SOUTHWARD TOWARD CHENANGO AND DELAWARE COUNTIES OVER THE NEXT
HOUR, AND INTENSIFY OVER THIS AREA OVER THE NEXT 3-4 HOURS. MODELS
HAVE PERFORMED QUITE POORLY WITH BOTH THE QPF AND FRONTOGENESIS
FIELDS SO FAR, SO IT IS NATURAL TO HAVE A HEALTHY DOSE OF
SKEPTICISM. HOWEVER WE ARE CLOSELY MONITORING RADAR/SAT TRENDS FOR
A SHIFT IN THE PRECIP AXIS.
WILL BE ASSESSING FLOOD WATCH FOR SOUTHWESTERN FA IN THE NEXT FEW
HOURS.
945 AM UPDATE...
MORNING THREAT FOR SEVERE THUNDERSTORMS OVER FAR SOUTHERN FA HAS
PASSED, SO WE HAVE CANCELLED THE WATCH FOR LUZERNE CO.
THIS MORNING...A GENERAL QUARTER TO HALF INCH OF RAIN HAS BEEN
OBSERVED TO THIS POINT, WITH AROUND A HALF INCH TO 1 INCH EXPECTED
TO HAVE ACCUMULATED BY EARLY AFTERNOON.
IMPRESSIVE DRY SLOT DEVELOPED EARLIER AND WILL HAVE A LARGE EFFECT
ON OUR POPS/QPF THROUGH EARLY AFTERNOON. MESOSCALE MODELS TRY TO
FILL IN THE DRY SLOT BETWEEN 1 PM AND 4 PM, IN ADVANCE OF 700MB
LOW AND RELATED FRONTOGENESIS AHEAD OF IT. MODEL PROJECTIONS WOULD
BRING THIS FAVORABLE AREA SOUTHEAST TOWARD THE TWIN TIERS DURING
THE AFTERNOON...AND THEN INTO THE EASTERN FA FOR LATE AFTERNOON
AND EARLY EVENING.
WE ARE PLAYING THE 700MB LOW / FRONTOGENESIS AS THE AREA WHERE
PRECIP WILL INCREASE FOR THE AFTERNOON INTO EARLY EVENING. TOTAL
STORM QPF VALUES WILL RANGE FROM 1 TO 2 INCHES, WITH HIGHER
AMOUNTS POSSIBLE ESPECIALLY OVER EASTERN FA WHERE LOW HANGS UP
LATE IN THE DAY.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
440 AM UPDATE...
SYSTEM PULLS MOISTURE EAST OF THE AREA AFT 06Z TONIGHT. HWVR, WITH
WATER STILL RUNNING OFF, CONCERN AFT THIS POINT WL BE HOW MUCH WL
LOCAL WATERWAYS RISE. IMMEDIATE FLASH FLOODING THREAT WL BE WINDING
DOWN LATE TONIGHT AS HEAVIEST PCPN COMES TO AN END.
ANOTHER CHC FOR SHOWERS WL MV INTO AREA ON FRIDAY AS A SFC BNDRY
FOLLOWS IN FM CANADA IN ADVANCE OF 1020MB HIPRES BUILDING IN. WITH
TEMPS PROGGED TO WARM INTO THE LWR 70S AND COOLING TEMPS ALOFT,
POTENTIAL WL EXIST FOR ISOLD THUNDER DRG THE AFTN.
HIPRES BUILDS IN FRI NGT BRINGING CLRNG SKIES AND TEMPS DROPPING
INTO THE 40S SATURDAY MRNG. AFN HIGHS ON SATURDAY PROGGED TO RISE
CLOSER TO NORMAL VALUES. NEXT SYSTEM PROGGED TO APPCH AFT THE SHORT
TERM PD.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
2 AM UPDATE...
LITTLE CHANGE. AGAIN FOLLOWED WPC GUIDANCE. UNSETTLED TO START
WITH MULTIPLE WEAK SYSTEMS GOING THROUGH THE REGION LATE SUNDAY TO
TUESDAY. HIGH PRESSURE WED TO THU. TEMPERATURES CLOSE TO AVERAGE.
PREVIOUS DISCUSSION...
UTILIZED WPC MED RNG GUIDANCE. LTL CHG TO CRNT FCST WITH HI PRES
RDG MOVG OFF THE EAST CST SAT NGT. A SERIES OF S/WV`S EMBEDDED
WITHIN THE WNW FLOW ALOFT WILL KEEP A CHC FOR SHRA/TSRA IN THE
FCST UNTIL TUE...WHEN THE LAST OF THESE SYSTEMS IS XPCTD TO PASS.
LARGE AREA OF HI PRES FOLLOWS FOR NXT TUE NGT AND WED.
&&
.AVIATION /17Z THURSDAY THROUGH MONDAY/...
7 AM UPDATE...
CONDITIONS WILL DETERIORATE TO MVFR WITH A CHANCE OF IFR AND OTHER
FUEL/ALTERNATE MINIMUMS POSSIBLE TODAY AS A STORM SYSTEM MOVES
ACROSS PENNSYLVANIA WITH WIDESPREAD RAIN FOR ALL LOCAL TAF SITES.
STEADY RAIN IS EXPECTED TO END THIS EVENING WITH LINGERING
MVFR/IFR RESTRICTIONS MOSTLY DUE TO CIGS. SOME LINGERING SHOWERS
TOO. CIGS AND VSBYS IMPROVING TO VFR LATE TONIGHT AND FRI
MORNING.
WINDS WILL BECOME PREVAILING EAST TO SOUTHEAST 5 TO 10 KTS EARLY
THIS MORNING. SPEEDS INCREASE 10-15 KTS AND GUSTY AT TIMES. A
FINAL SHIFT TO NW TO NE LATE AFTN AND THIS EVENING AT 10 KTS.
OUTLOOK...
FRI...IMPRVNG TO VFR.
FRI NGT/SAT/SAT NGT...VFR BUT POTENTIAL VALLEY FOG SAT AM AT ELM.
SUN TO MON...MAINLY VFR...BUT MVFR IN SHRA/TSRA.
&&
.HYDROLOGY...
POSSIBLE RIVER AND FLASH FLOODING TODAY INTO FRIDAY. 1 TO 3 INCHES
AND MAYBE MORE. STILL QUESTIONS ON PLACEMENT OF HEAVIEST RAIN.
MOST MODELS HAVE IT IN THE SRN TIER TO CATSKILLS OF NY WHILE THE
EURO AND WPC IS FURTHER SOUTH IN THE NRN TIER OF NE PA. BOTH WAYS
FINGER LAKES TO MOHAWK VALLEY AROUND AN INCH AND NOT IN THE FLOOD
WATCH. WITH HIGH PWATS AND TSTMS RAINFALL RATES COULD EXCEED AN
INCH AN HOUR FOR SHORT PERIODS. 2 INCHES WILL START TO CAUSE
PROBLEMS AND 3 AND MORE WILL BE WORSE. NOT EXPECTING WIDESPREAD 3
PLUS SO RIVER FLOODING WILL ONLY BE MINOR. FOR NOW SUSQUEHANNA
RIVER AT VESTAL AND WAVERLY/SAYRE ARE FORECAST TO HAVE MINOR
FLOODING. WALTON ON THE WEST BRANCH DELAWARE WILL GET CLOSE.
HEADWATERS AT CORTLAND AND SHERBURNE NOT IN THE HEAVY RAIN AXIS
BUT IF IT SETS UP 50 MILES FURTHER NORTH THESE POINTS WILL FLOOD.
FOR NOW RIVER FLOODING EXPECTED FRIDAY SO NO WARNINGS ISSUED UNTIL
RAIN COMES IN AND CONFIDENCE INCREASES.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...FLOOD WATCH THROUGH FRIDAY MORNING FOR PAZ040-048-072.
NY...FLOOD WATCH THROUGH FRIDAY MORNING FOR NYZ025-044>046-056-057-
062.
&&
$$
SYNOPSIS...DJP
NEAR TERM...DJP
SHORT TERM...PVN
LONG TERM...TAC
AVIATION...TAC
HYDROLOGY...
AREA FORECAST DISCUSSION
NWS RALEIGH NC
301 PM EDT THU JUN 13 2013
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL CROSS THE MID ATLANTIC...AND THE TRAILING
COLD FRONT WILL CROSS THE REGION THROUGH TONIGHT. HIGH PRESSURE WILL
BUILD IN BEHIND THE FRONT FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 300 PM THURSDAY...
...PARTICULARLY DANGEROUS SITUATION SEVERE THUNDERSTORM WATCH IN
EFFECT...
PDS SEVERE THUNDERSTORM WATCH IS IN EFFECT UNTIL 10 PM. THE LATEST
SPC MESOANALYSIS PAGE SHOWED MLCAPE FROM NEARLY 2000J/KG TO CLOSE TO
4000J/KG ACROSS CENTRAL NORTH CAROLINA. 0-6KM SHEAR WAS STILL BETTER
NORTH...FROM NEAR THE VIRGINIA BORDER NORTH INTO VIRGINIA...BUT
DOWNDRAFT CAPE WAS A ROBUST 1000-1500J/KG THROUGHOUT CENTRAL NORTH
CAROLINA. MSAS SURFACE-BASED LIFTED INDICES WERE -8C TO -10C. THE
LATEST KGSO SOUNDING...FROM 18Z...SHOWED A CAP REMAINING AROUND
800MB BUT WITH THE LAYER AROUND 800MB COOLING SINCE 12Z. THE 18Z
SOUNDING AT KRNK SHOWED THE CAP JUST ABOVE 800MB HAD ERODED...
SUFFICIENTLY FOR A GUST AT KROA TO 59KT WITH STORM PASSAGE AT 1828Z.
THE LATEST HRRR WRF CONTINUES WITH A TIMING OF 19Z TO 21Z IN THE
IMMEDIATE TRIAD...21Z TO 23Z IN THE TRIANGLE NEAR KRDU AND SOUTHWEST
ALONG U.S. 1...AND IN VICINITY OF 22Z OR JUST A LITTLE LATER TOWARD
KRWI...KFAY...AND THE INTERSTATE 95 CORRIDOR. WHILE THE 0-3KM STORM
RELATIVE HELICITY ON THE 18Z KGSO SOUNDING WAS 84M2/S2...ONE STILL
CANNOT COMPLETELY RULE OUT A TORNADO...AS STORM RELATIVE HELICITY IN
THE LOWEST 3KM ON THE SPC MESOANALYSIS PAGE APPEARED PRETTY ACCURATE
AND WAS ABOVE 100M2/S2 OVER MOST OF THE REST OF CENTRAL NORTH
CAROLINA...HIGHEST RELATIVE TO THE REST OF CENTRAL NORTH CAROLINA
NORTHEAST OF THE TRIANGLE. -10C TO -30C CAPE IS ON THE ORDER OF
1000J/KG AS WELL...SUFFICIENT FOR THE POTENTIAL FOR LARGE HAIL AND
ASSISTING WITH FREQUENT LIGHTNING POTENTIAL WITH THE STRONGEST
STORMS...ALREADY SHOWN ON THE 15-MINUTE LIGHTNING PLOT EXTENDING
FROM VIRGINIA SOUTHWEST INTO THE MOUNTAINS.
OVERNIGHT...SUBSIDENCE AND GRADUAL CLEARING SHOULD TAKE PLACE BEHIND
THE DEEP CONVECTION. THE COLD FRONT SHOULD LAG THE DEEP
CONVECTION...AND WILL HOLD ONTO POPS FOR A SHORT PERIOD BEHIND THE
TIMING NOTED ABOVE. HOWEVER...NAM AND GFS BUFR SOUNDINGS SHOW AN
INCREASING STABLE AIR MASS WITH DIMINISHING LAPSE RATES ALOFT. WILL
HAVE POPS BELOW SLIGHT CHANCE THROUGHOUT CENTRAL NORTH CAROLINA BY
05Z...AND THIS COULD END UP BEING SLOW EVEN IN THE FAR SOUTHEAST
TOWARD KCTZ. LOWS IN THE LOWER TO MID 60S.
FRIDAY...IN THE TIGHT GRADIENT IN THE MORNING BEHIND THE DEPARTING
STRONG LOW...WIND GUSTS SHOULD INCREASE TO AROUND 20KT IN PLACES
WITH MIXING. THESE VALUES SUBSIDE DURING THE AFTERNOON AS 850MB AND
925MB WINDS DIMINISH. WHILE PRECIPITABLE WATER AND K INDICES SHOW A
BRIEF INCREASE FRIDAY AFTERNOON AHEAD OF ANOTHER MID-LEVEL SHORTWAVE
AND THE APPROACH OF THE LEFT EXIT REGION OF A 85KT 300MB AND 55KT
500MB JET...DIVERGENCE AT 850MB AND STABLE BUFR SOUNDINGS SHOULD
PRECLUDE ANY RELATIVELY DEEP CONVECTION. BUFR SOUNDINGS...HOWEVER...
NOTE THE POTENTIAL FOR SHALLOW HIGH SC OR LOW AC DURING THE
AFTERNOON...AND WILL AT LEAST FEATURE IN THE GRIDDED FORECAST A
PARTLY SUNNY SKY FOR MUCH OF THE AFTERNOON. HIGHS IN THE LOWER TO
MID 80S.
&&
.SHORT TERM /FRIDAY NIGHT AND SATURDAY NIGHT/...
AS OF 300 PM THURSDAY...
BEHIND THE DEPARTING SYSTEM...CONDITIONS WILL DRY OUT AND COOL DOWN
THROUGH THE EARLY PART OF THE WEEKEND. SURFACE HIGH PRESSURE AND
RISING HEIGHTS ALOFT (ALTHOUGH THE CORE OF THE MID/UPPER HIGH WILL
REMAIN WEST OF OF THE REGION BEFORE FLATTENING OUT BY THE LATTER
HALF OF THE WEEKEND) WILL LEAD TO MORE SUNSHINE AND MOSTLY DRY
CONDITIONS THROUGH SATURDAY NIGHT. TEMPS SHOULD STAY SLIGHTLY BELOW
NORMAL...WITH HIGHS GENERALLY IN THE MID 80S. COMFORTABLE OVERNIGHT
LOWS ARE EXPECTED FRIDAY NIGHT...MOSTLY LOWER 60S...BUT SOME UPPER
50S WILL BE POSSIBLE...WITH A SLIGHT MODERATION FOR SATURDAY NIGHT
AS LOW LEVEL MOISTURE SLOWLY BEGINS TO RETURN.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 245 PM THURSDAY...
THE NEXT SYSTEM WILL APPROACH THE REGION EARLY NEXT WEEK...BUT THERE
ARE STILL SOME TIMING/STRENGTH ISSUES BETWEEN THE MODELS. AT THIS
TIME...IT APPEARS SUNDAY/SUNDAY NIGHT WILL REMAIN MOSTLY DRY AS THE
STORM SYSTEM REMAINS TO OUR NORTH AND WEST. BY MONDAY...WITH
INCREASING SOUTHWESTERLY FLOW...WE WILL REALLY BEGIN TO SEE OUR
MOISTURE RETURN...WITH PWAT VALUES RISING ABOVE 1.5 INCHES. THE
TRAILING COLD FRONT WILL STILL BE EAST OF THE AREA ON MONDAY...
THEREFORE AM EXPECTING MOSTLY DIURNALLY FORCED SHOWERS AND
THUNDERSTORMS. THE TRAILING FRONT LOOKS TO CROSS THE AREA SOMETIME
TUESDAY/TUESDAY NIGHT...THEREFORE THIS IS WHEN THE HIGHEST PRECIP
CHANCES WILL BE FOCUSED. THE FRONT LOOKS TO STALL SOMEWHERE NEAR THE
NC/SC BORDER FOR WEDNESDAY AND THURSDAY AND THIS WILL BE WHAT
ULTIMATELY DRIVES OUR PRECIP CHANCES FOR THE REMAINDER OF THE
FORECAST PERIOD. FOR NOW WILL KEEP SOME POPS (MOSTLY SLIGHT CHANCE)
IN FOR THIS TIME FRAME AND DUE TO THE PROXIMITY OF THE FRONT...THE
SOUTHERN PORTIONS OF THE FORECAST AREA WILL BE THE MOST LIKELY AREA
TO RECEIVE SOME PRECIP. TEMPS WILL BE NEAR NORMAL AHEAD OF THE
FRONT...WITH SLIGHTLY BELOW NORMAL TEMPS BEHIND THE FRONT.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 112 PM THURSDAY...
VFR CONDITIONS WILL BE PREVALENT THROUGH THE 18Z VALID TAF PERIOD
OUTSIDE OF DEEP CONVECTION. A LINE OF THUNDERSTORMS IS EXPECTED TO
PASS THROUGH CENTRAL NORTH CAROLINA DURING THE AFTERNOON AND EVENING
HOURS. THE TIMING CONTINUES TO SEEM SIMILAR TO THAT NOTED IN THE
PREVIOUS DISCUSSION BASED ON THE LATEST GUIDANCE...19Z TO 21Z IN THE
IMMEDIATE TRIAD...21Z TO 23Z IN THE TRIANGLE NEAR KRDU...AND IN
VICINITY OF 22Z TOWARD KRWI AND KFAY. SIGNIFICANT CROSSWINDS COULD
DEVELOP WITH POTENTIALLY SEVERE THUNDERSTORM WIND GUSTS. THE
GRADIENT SHOULD TIGHTEN LATE THIS AFTERNOON AND STILL ANTICIPATE A
FEW WIND GUSTS NEAR 30KT WITH MIXING AHEAD OF DEEP CONVECTION. WINDS
WILL GRADUALLY VEER TO WEST AND NORTHWEST OR NORTH-NORTHWEST
OVERNIGHT INTO EARLY FRIDAY AS SKIES GRADUALLY CLEAR. FRIDAY
MORNING...WITH MIXING AND A TIGHT GRADIENT BEHIND STRONG LOW
PRESSURE OFF OF THE MID-ATLANTIC MOVING AWAY FROM THE REGION...
EXPECT A FEW SURFACE WIND GUSTS TO AROUND 20KT.
BEYOND THE 18Z VALID TAF PERIOD...VFR CONDITIONS WILL DOMINATE THE
WEEKEND. THERE WILL BE A GRADUAL INCREASE IN CHANCES FOR SHOWERS AND
THUNDERSTORMS EARLY NEXT WEEK AS THE AIR MASS MOISTENS AND AHEAD OF
A COLD FRONT THAT SHOULD MOVE THROUGH CENTRAL NORTH CAROLINA VERY
LATE TUESDAY INTO TUESDAY NIGHT. THERE IS ALSO AT LEAST A SMALL
CHANCE OF MORNING LOW CLOUDS TUESDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SEC
NEAR TERM...DJF
SHORT TERM...KRR
LONG TERM...KRR
AVIATION...DJF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
112 PM EDT THU JUN 13 2013
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL CROSS THE MID ATLANTIC...AND THE TRAILING
COLD FRONT WILL CROSS THE REGION THROUGH TONIGHT. HIGH PRESSURE WILL
BUILD IN BEHIND THE FRONT FOR THE WEEKEND.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 1045 AM THURSDAY...
...AREAS OF SEVERE WEATHER APPEAR PROBABLE THIS AFTERNOON INTO THIS
EVENING...
THE MORNING SOUNDING FROM KGSO SHOWED A GOOD CAP BETWEEN 900MB AND
ROUGHLY 700MB...AND PRECIPITABLE WATER VALUES WERE RELATIVELY DRY...
BELOW 1.25 INCHES. JUST UPSTREAM...HOWEVER...THE KRNK SOUNDING
SHOWED SOME OF THAT CAP ERODING...WHICH IS INDEED FORECAST BY THE
GUIDANCE DURING THE AFTERNOON. AS NEARLY 100M HEIGHT FALLS...NOTED
UPSTREAM TO OUR NORTHWEST AT 500MB ON THE 12Z UPPER-AIR ANALYSES...
HEAD TOWARD VIRGINIA THIS AFTERNOON...THE CAP SHOULD ERODE. WITH
INSTABILITY ALREADY SOMEWHAT PLENTIFUL THIS MORNING...AS THE SPC
MESOANALYSIS PAGE SHOWS A MIXED-LAYER CAPE WELL OVER 2000J/KG
NORTHEAST OF THE TRIANGLE...500-1000J/KG OVER THE SOUTHWEST
PIEDMONT...THUNDERSTORMS SHOULD BEGIN TO DEVELOP. DEVELOPMENT COULD
BE FAIRLY RAPID AS THE CAP ERODES AND DRY AIR IS OVERCOME...WITH
STEEP LAPSE RATES ABOVE THE CAP...NEARLY DRY ADIABATIC ON THE
MORNING SOUNDINGS...AND FORECAST TO BE AROUND 7C/KM IN THE
1000-500MB LAYER BY LATE AFTERNOON. INSTABILITY SHOULD BE GREATEST
ALONG AND EAST OF U.S. 1...BUT THAT IS RELATIVE TO THE REST OF
CENTRAL NORTH CAROLINA AND LIFTED INDICES ARE FORECAST TO CERTAINLY
BE COOL ENOUGH FOR DEEP CONVECTION EVEN IN THE FAR WESTERN PIEDMONT
THIS AFTERNOON. THE LATEST TIMING WOULD SUGGEST THUNDERSTORM
DEVELOPMENT BETWEEN 19Z AND 21Z TOWARD THE TRIAD...20Z TO 23Z IN
VICINITY OF THE U.S. 1 CORRIDOR...AND 22Z OR SO TOWARD INTERSTATE 95
ESPECIALLY FROM ROCKY MOUNT SOUTH. THESE TIMES ARE IN CONCERT WITH
THE EROSION OF THE CAP AS FORECAST BY THE LATEST RAP...AS WELL AS
THE LATEST HRRR WRF. DAMAGING WINDS ARE THE PRIMARY THREAT AS 850MB
WINDS INCREASE TO 40KT...AND 925MB WINDS TO 35KT...THIS AFTERNOON...
BUT CANNOT COMPLETELY RULE OUT OTHER SEVERE WEATHER PARAMETERS.
OUTSIDE OF ANY URBAN CONCERNS...CURRENTLY THINK PROGRESS OF ANY
THUNDERSTORMS SHOULD BE ENOUGH TO PRECLUDE FLASH FLOODING.
TEMPERATURES HAVE BEEN RISING QUICKLY THIS MORNING. 1000-850MB
THICKNESSES SUGGESTED HIGHS A TRIFLE WARMER THAN FORECAST...AND
ESPECIALLY EAST OF U.S. 1 HAVE RAISED MAXES A DEGREE OR TWO AS
SUNSHINE SHOULD BE CONSIDERABLE FOR LONGER THERE. HIGHS SHOULD BE 90
TO 95 TOWARD THE TRIAD...AND MID TO UPPER 90S ACROSS MOST OF THE
REST OF CENTRAL NORTH CAROLINA. ANTICIPATE JUST ENOUGH MIXING TO
LOWER DEW POINTS SUCH THAT HEAT INDICES SHOULD REMAIN BELOW ADVISORY
CRITERIA...BUT STILL AS HIGH AS AROUND 103F TOWARD KMEB...KFAY...AND
KCTZ. ALREADY...THE HEAT INDEX IS JUST OVER 100F AT KCTZ.
THERE SHOULD BE GOOD MIXING THIS AFTERNOON...AND ONCE THE CAP ERODES
A FEW GUSTS AROUND 30KT ARE PROBABLE...AND ONE OR TWO CLOSE TO 35KT.
GIVEN THE WET GROUND OF LATE...AN ISOLATED SHALLOWLY-ROOTED TREE OR
THREE COULD FALL AHEAD OF ANY THUNDERSTORMS IF WE ARE ABLE TO
RESOLVE SUCH WIND GUSTS. CERTAINLY...THE WET GROUND IS A CONCERN FOR
THUNDERSTORMS ANTICIPATED TO MOVE THROUGH LATER TODAY. LIGHTNING
SHOULD ALSO BE FREQUENT WITH ANY THUNDERSTORM GIVEN THE INSTABILITY
AND MOISTURE ALOFT...-10C TO -30C CAPE IS 1000-1500J/KG THIS
AFTERNOON.
SUNNY SKIES EARLY THIS AFTERNOON...FOLLOWING BY INCREASING CLOUDS
AHEAD OF ANY DEEP CONVECTION FROM THE NORTHWEST. ANTICIPATING THE
GREATER INSOLATION AND INSTABILITY EAST...HAVE LOWER LIKELY POPS
TOWARD THE TRIAD...VERY HIGH LIKELY POPS TOWARD INTERSTATE 95.
OVERNIGHT LOWS 65 TO 70 WITH CLEARING TAKING PLACE BEHIND THE DEEP
CONVECTION.
&&
.SHORT TERM /FRIDAY AND FRIDAY NIGHT/...
AS OF 330 AM THURSDAY...
IN THE WAKE OF THE COLD FRONTAL PASSAGE AND ADDITIONAL SHORTWAVE
ENERGY PROGRESSING OFFSHORE THE MID-ATLANTIC COAST FRIDAY
MORNING...EXPECT CLEAR SKIES AND COOLER TEMPERATURES WITH HIGHS IN
THE LOWER TO MID 80S (COOLEST NORTH) WITH LOWS IN THE LOWER
60S...PERHAPS IN THE UPPER 50S IN RURAL/LOW-LYING AREAS. -VINCENT
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 220 AM THURSDAY...
A DRY WEEKEND FOLLOWED BY INCREASING CHANCE OF MAINLY DIURNAL
SHOWERS AND THUNDERSTORMS MON-TUE NEXT WEEK.
MODELS ARE IN EXCELLENT AGREEMENT IN THE MID-UPPER LEVEL FLOW
PATTERN OVER THE EASTERN UNITED STATES THIS WEEKEND INTO MID NEXT
WEEK. NORTH CAROLINA WILL BE ON THE BACK SIDE OF THE DEPARTING
TROUGH OUT INTO THE ATLANTIC SATURDAY. STRONG SUBSIDENCE WILL
COMBINE WITH A STRONG SURFACE HIGH PRESSURE TRACKING FROM THE GREAT
LAKES TO OFFSHORE OF THE MID-ATLANTIC COAST SAT-SUN TO BRING A MILD
TO WARM AND DRY WEEKEND. LOWS WILL BE QUITE PLEASANT FOR MID JUNE
WITH READINGS IN THE 55-60 RANGE NORTH... AND 60-65 SOUTH SATURDAY
MORNING... MODIFYING TO THE LOWER TO MID 60S SUNDAY MORNING. GIVEN
THE 30 YEAR AVERAGES WILL BE IN THE MID TO UPPER 60S SAT-SUN...
THESE LOWS WILL BE A GOOD 5-10 DEGREES BELOW NORMAL. HIGHS BOTH DAYS
SHOULD REACH THE LOWER TO MID 80S... WITH MORE IN THE WAY OF MID 80S
SUNDAY.
MON-WED... A MID-UPPER LEVEL TROUGH IS EXPECTED TO TRACK FROM THE
UPPER MIDWEST TO OFF THE MID-ATLANTIC COAST AGAIN THIS PERIOD. THE
MAIN STORM TRACK IS AGAIN FORECAST WITH MODERATE TO HIGH CONFIDENCE
TO BE FROM THE UPPER MIDWEST SE TO THE OHIO VALLEY THEN OFF THE
MID-ATLANTIC COAST. THIS WOULD PLACE AREAS TO OUR NORTH AT THE
GREATEST RISK OF SEVERE STORMS. HOWEVER... THE TRAILING COLD FRONT
IS EXPECTED TO ARRIVE LATE TUESDAY AND TUESDAY NIGHT BRINGING
ANOTHER ROUND OF ENHANCED THUNDERSTORM POTENTIAL FOR OUR REGION. THE
CHANCES OF DIURNAL CONVECTION SHOULD INCREASE AS EARLY AS MONDAY
AFTERNOON/EVENING AS SSW FLOW INCREASES THE OVERALL MOISTURE PROFILE
ACROSS THE APPALACHIANS AND NC. HOWEVER... THE HIGHEST PROBABILITY
OF THUNDERSTORMS APPEARS TO BE TUESDAY AFTERNOON AND NIGHT AS THE
MID/UPPER TROUGH AND COLD FRONT APPROACH DURING OR AFTER PEAK
HEATING. THE CHANCE OF SHOWERS AND THUNDERSTORMS MAY CONTINUE...
ESPECIALLY IN THE SE ON WED AS THE FRONT APPEARS TO SLOW DOWN AND
POSSIBLY STALL NEAR SE NC ON WED. HIGHS MONDAY SHOULD BE 85-90 AFTER
LOWS OF 65-70. LOWS TUESDAY 70-74 WITH HIGHS IN THE MID TO UPPER
80S. WEDNESDAY SHOULD BE A BIT COOLER STILL... WITH LOWS 65-70.
HIGHS IN THE LOWER TO MID 80S WITH VARIABLY CLOUDY SKIES.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 112 PM THURSDAY...
VFR CONDITIONS WILL BE PREVALENT THROUGH THE 18Z VALID TAF PERIOD
OUTSIDE OF DEEP CONVECTION. A LINE OF THUNDERSTORMS IS EXPECTED TO
PASS THROUGH CENTRAL NORTH CAROLINA DURING THE AFTERNOON AND EVENING
HOURS. THE TIMING CONTINUES TO SEEM SIMILAR TO THAT NOTED IN THE
PREVIOUS DISCUSSION BASED ON THE LATEST GUIDANCE...19Z TO 21Z IN THE
IMMEDIATE TRIAD...21Z TO 23Z IN THE TRIANGLE NEAR KRDU...AND IN
VICINITY OF 22Z TOWARD KRWI AND KFAY. SIGNIFICANT CROSSWINDS COULD
DEVELOP WITH POTENTIALLY SEVERE THUNDERSTORM WIND GUSTS. THE
GRADIENT SHOULD TIGHTEN LATE THIS AFTERNOON AND STILL ANTICIPATE A
FEW WIND GUSTS NEAR 30KT WITH MIXING AHEAD OF DEEP CONVECTION. WINDS
WILL GRADUALLY VEER TO WEST AND NORTHWEST OR NORTH-NORTHWEST
OVERNIGHT INTO EARLY FRIDAY AS SKIES GRADUALLY CLEAR. FRIDAY
MORNING...WITH MIXING AND A TIGHT GRADIENT BEHIND STRONG LOW
PRESSURE OFF OF THE MID-ATLANTIC MOVING AWAY FROM THE REGION...
EXPECT A FEW SURFACE WIND GUSTS TO AROUND 20KT.
BEYOND THE 18Z VALID TAF PERIOD...VFR CONDITIONS WILL DOMINATE THE
WEEKEND. THERE WILL BE A GRADUAL INCREASE IN CHANCES FOR SHOWERS AND
THUNDERSTORMS EARLY NEXT WEEK AS THE AIR MASS MOISTENS AND AHEAD OF
A COLD FRONT THAT SHOULD MOVE THROUGH CENTRAL NORTH CAROLINA VERY
LATE TUESDAY INTO TUESDAY NIGHT. THERE IS ALSO AT LEAST A SMALL
CHANCE OF MORNING LOW CLOUDS TUESDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SEC
NEAR TERM...DJF/VINCENT
SHORT TERM...VINCENT
LONG TERM...PWB
AVIATION...DJF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1045 AM EDT THU JUN 13 2013
.SYNOPSIS...
AN UNSEASONABLY STRONG LOW PRESSURE SYSTEM AND ASSOCIATED COLD FRONT
WILL TRACK QUICKLY EAST ACROSS THE MID-ATLANTIC AND CAROLINAS THIS
AFTERNOON AND EVENING. HIGH PRESSURE WILL BUILD OVER THE REGION IN
THE WAKE OF THE FRONT FRIDAY INTO THE WEEKEND.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 1045 AM THURSDAY...
...AREAS OF SEVERE WEATHER APPEAR PROBABLE THIS AFTERNOON INTO THIS
EVENING...
THE MORNING SOUNDING FROM KGSO SHOWED A GOOD CAP BETWEEN 900MB AND
ROUGHLY 700MB...AND PRECIPITABLE WATER VALUES WERE RELATIVELY DRY...
BELOW 1.25 INCHES. JUST UPSTREAM...HOWEVER...THE KRNK SOUNDING
SHOWED SOME OF THAT CAP ERODING...WHICH IS INDEED FORECAST BY THE
GUIDANCE DURING THE AFTERNOON. AS NEARLY 100M HEIGHT FALLS...NOTED
UPSTREAM TO OUR NORTHWEST AT 500MB ON THE 12Z UPPER-AIR ANALYSES...
HEAD TOWARD VIRGINIA THIS AFTERNOON...THE CAP SHOULD ERODE. WITH
INSTABILITY ALREADY SOMEWHAT PLENTIFUL THIS MORNING...AS THE SPC
MESOANALYSIS PAGE SHOWS A MIXED-LAYER CAPE WELL OVER 2000J/KG
NORTHEAST OF THE TRIANGLE...500-1000J/KG OVER THE SOUTHWEST
PIEDMONT...THUNDERSTORMS SHOULD BEGIN TO DEVELOP. DEVELOPMENT COULD
BE FAIRLY RAPID AS THE CAP ERODES AND DRY AIR IS OVERCOME...WITH
STEEP LAPSE RATES ABOVE THE CAP...NEARLY DRY ADIABATIC ON THE
MORNING SOUNDINGS...AND FORECAST TO BE AROUND 7C/KM IN THE
1000-500MB LAYER BY LATE AFTERNOON. INSTABILITY SHOULD BE GREATEST
ALONG AND EAST OF U.S. 1...BUT THAT IS RELATIVE TO THE REST OF
CENTRAL NORTH CAROLINA AND LIFTED INDICES ARE FORECAST TO CERTAINLY
BE COOL ENOUGH FOR DEEP CONVECTION EVEN IN THE FAR WESTERN PIEDMONT
THIS AFTERNOON. THE LATEST TIMING WOULD SUGGEST THUNDERSTORM
DEVELOPMENT BETWEEN 19Z AND 21Z TOWARD THE TRIAD...20Z TO 23Z IN
VICINITY OF THE U.S. 1 CORRIDOR...AND 22Z OR SO TOWARD INTERSTATE 95
ESPECIALLY FROM ROCKY MOUNT SOUTH. THESE TIMES ARE IN CONCERT WITH
THE EROSION OF THE CAP AS FORECAST BY THE LATEST RAP...AS WELL AS
THE LATEST HRRR WRF. DAMAGING WINDS ARE THE PRIMARY THREAT AS 850MB
WINDS INCREASE TO 40KT...AND 925MB WINDS TO 35KT...THIS AFTERNOON...
BUT CANNOT COMPLETELY RULE OUT OTHER SEVERE WEATHER PARAMETERS.
OUTSIDE OF ANY URBAN CONCERNS...CURRENTLY THINK PROGRESS OF ANY
THUNDERSTORMS SHOULD BE ENOUGH TO PRECLUDE FLASH FLOODING.
TEMPERATURES HAVE BEEN RISING QUICKLY THIS MORNING. 1000-850MB
THICKNESSES SUGGESTED HIGHS A TRIFLE WARMER THAN FORECAST...AND
ESPECIALLY EAST OF U.S. 1 HAVE RAISED MAXES A DEGREE OR TWO AS
SUNSHINE SHOULD BE CONSIDERABLE FOR LONGER THERE. HIGHS SHOULD BE 90
TO 95 TOWARD THE TRIAD...AND MID TO UPPER 90S ACROSS MOST OF THE
REST OF CENTRAL NORTH CAROLINA. ANTICIPATE JUST ENOUGH MIXING TO
LOWER DEW POINTS SUCH THAT HEAT INDICES SHOULD REMAIN BELOW ADVISORY
CRITERIA...BUT STILL AS HIGH AS AROUND 103F TOWARD KMEB...KFAY...AND
KCTZ. ALREADY...THE HEAT INDEX IS JUST OVER 100F AT KCTZ.
THERE SHOULD BE GOOD MIXING THIS AFTERNOON...AND ONCE THE CAP ERODES
A FEW GUSTS AROUND 30KT ARE PROBABLE...AND ONE OR TWO CLOSE TO 35KT.
GIVEN THE WET GROUND OF LATE...AN ISOLATED SHALLOWLY-ROOTED TREE OR
THREE COULD FALL AHEAD OF ANY THUNDERSTORMS IF WE ARE ABLE TO
RESOLVE SUCH WIND GUSTS. CERTAINLY...THE WET GROUND IS A CONCERN FOR
THUNDERSTORMS ANTICIPATED TO MOVE THROUGH LATER TODAY. LIGHTNING
SHOULD ALSO BE FREQUENT WITH ANY THUNDERSTORM GIVEN THE INSTABILITY
AND MOISTURE ALOFT...-10C TO -30C CAPE IS 1000-1500J/KG THIS
AFTERNOON.
SUNNY SKIES EARLY THIS AFTERNOON...FOLLOWING BY INCREASING CLOUDS
AHEAD OF ANY DEEP CONVECTION FROM THE NORTHWEST. ANTICIPATING THE
GREATER INSOLATION AND INSTABILITY EAST...HAVE LOWER LIKELY POPS
TOWARD THE TRIAD...VERY HIGH LIKELY POPS TOWARD INTERSTATE 95.
OVERNIGHT LOWS 65 TO 70 WITH CLEARING TAKING PLACE BEHIND THE DEEP
CONVECTION.
&&
.SHORT TERM /FRIDAY AND FRIDAY NIGHT/...
AS OF 330 AM THURSDAY...
IN THE WAKE OF THE COLD FRONTAL PASSAGE AND ADDITIONAL SHORTWAVE
ENERGY PROGRESSING OFFSHORE THE MID-ATLANTIC COAST FRIDAY
MORNING...EXPECT CLEAR SKIES AND COOLER TEMPERATURES WITH HIGHS IN
THE LOWER TO MID 80S (COOLEST NORTH) WITH LOWS IN THE LOWER
60S...PERHAPS IN THE UPPER 50S IN RURAL/LOW-LYING AREAS. -VINCENT
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 220 AM THURSDAY...
A DRY WEEKEND FOLLOWED BY INCREASING CHANCE OF MAINLY DIURNAL
SHOWERS AND THUNDERSTORMS MON-TUE NEXT WEEK.
MODELS ARE IN EXCELLENT AGREEMENT IN THE MID-UPPER LEVEL FLOW
PATTERN OVER THE EASTERN UNITED STATES THIS WEEKEND INTO MID NEXT
WEEK. NORTH CAROLINA WILL BE ON THE BACK SIDE OF THE DEPARTING
TROUGH OUT INTO THE ATLANTIC SATURDAY. STRONG SUBSIDENCE WILL
COMBINE WITH A STRONG SURFACE HIGH PRESSURE TRACKING FROM THE GREAT
LAKES TO OFFSHORE OF THE MID-ATLANTIC COAST SAT-SUN TO BRING A MILD
TO WARM AND DRY WEEKEND. LOWS WILL BE QUITE PLEASANT FOR MID JUNE
WITH READINGS IN THE 55-60 RANGE NORTH... AND 60-65 SOUTH SATURDAY
MORNING... MODIFYING TO THE LOWER TO MID 60S SUNDAY MORNING. GIVEN
THE 30 YEAR AVERAGES WILL BE IN THE MID TO UPPER 60S SAT-SUN...
THESE LOWS WILL BE A GOOD 5-10 DEGREES BELOW NORMAL. HIGHS BOTH DAYS
SHOULD REACH THE LOWER TO MID 80S... WITH MORE IN THE WAY OF MID 80S
SUNDAY.
MON-WED... A MID-UPPER LEVEL TROUGH IS EXPECTED TO TRACK FROM THE
UPPER MIDWEST TO OFF THE MID-ATLANTIC COAST AGAIN THIS PERIOD. THE
MAIN STORM TRACK IS AGAIN FORECAST WITH MODERATE TO HIGH CONFIDENCE
TO BE FROM THE UPPER MIDWEST SE TO THE OHIO VALLEY THEN OFF THE
MID-ATLANTIC COAST. THIS WOULD PLACE AREAS TO OUR NORTH AT THE
GREATEST RISK OF SEVERE STORMS. HOWEVER... THE TRAILING COLD FRONT
IS EXPECTED TO ARRIVE LATE TUESDAY AND TUESDAY NIGHT BRINGING
ANOTHER ROUND OF ENHANCED THUNDERSTORM POTENTIAL FOR OUR REGION. THE
CHANCES OF DIURNAL CONVECTION SHOULD INCREASE AS EARLY AS MONDAY
AFTERNOON/EVENING AS SSW FLOW INCREASES THE OVERALL MOISTURE PROFILE
ACROSS THE APPALACHIANS AND NC. HOWEVER... THE HIGHEST PROBABILITY
OF THUNDERSTORMS APPEARS TO BE TUESDAY AFTERNOON AND NIGHT AS THE
MID/UPPER TROUGH AND COLD FRONT APPROACH DURING OR AFTER PEAK
HEATING. THE CHANCE OF SHOWERS AND THUNDERSTORMS MAY CONTINUE...
ESPECIALLY IN THE SE ON WED AS THE FRONT APPEARS TO SLOW DOWN AND
POSSIBLY STALL NEAR SE NC ON WED. HIGHS MONDAY SHOULD BE 85-90 AFTER
LOWS OF 65-70. LOWS TUESDAY 70-74 WITH HIGHS IN THE MID TO UPPER
80S. WEDNESDAY SHOULD BE A BIT COOLER STILL... WITH LOWS 65-70.
HIGHS IN THE LOWER TO MID 80S WITH VARIABLY CLOUDY SKIES.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
AS OF 1045 AM THURSDAY...
24-HR TAF PERIOD:
VFR CONDITIONS ARE EXPECTED TO PREVAIL UNTIL DEEP CONVECTION MOVES
IN WITH NUMEROUS THUNDERSTORMS EXPECTED THIS AFTERNOON. THE TIMING
OF THUNDERSTORMS CURRENTLY IS ANTICIPATED TO BE 19Z TO 21Z IN THE
IMMEDIATE TRIAD...20Z TO 23Z IN THE TRIANGLE NEAR KRDU...AND IN
VICINITY OF 22Z TOWARD KRWI AND KFAY. SIGNIFICANT CROSSWINDS COULD
DEVELOP WITH POTENTIALLY SEVERE THUNDERSTORM WIND GUSTS THIS
AFTERNOON. A FEW OF THE TAF SITES...ESPECIALLY KRDU...KRWI...AND
KFAY COULD SEE A FEW WIND GUSTS AT OR JUST ABOVE 30KT THIS AFTERNOON
IN A TIGHTENING GRADIENT WITH MIXING AHEAD OF DEEP CONVECTION. WINDS
WILL SHIFT TO THE NW/NNW AT 10-15 KT IN THE WAKE OF THE COLD FRONT
BY THE END OF THE TAF PERIOD...MOST LIKELY BETWEEN 03-06Z FRIDAY.
LOOKING AHEAD:
VFR CONDITIONS WILL PREVAIL IN THE WAKE OF THE COLD FRONT FRIDAY
THROUGH MOST IF NOT ALL OF THE WEEKEND. EXPECT AN INCREASING CHANCE
FOR SHOWERS AND THUNDERSTORMS SUNDAY NIGHT-TUESDAY IN ADVANCE OF
ANOTHER COLD FRONT APPROACHING THE REGION FROM THE WEST.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...DJF/VINCENT
SHORT TERM...VINCENT
LONG TERM...PWB
AVIATION...DJF/VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
220 AM EDT THU JUN 13 2013
.SYNOPSIS...
AN UNSEASONABLY STRONG LOW PRESSURE SYSTEM AND ASSOCIATED COLD FRONT
WILL TRACK QUICKLY EAST ACROSS THE MID-ATLANTIC AND CAROLINAS THIS
AFTERNOON AND EVENING. HIGH PRESSURE WILL BUILD OVER THE REGION IN
THE WAKE OF THE FRONT FRIDAY INTO THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
AS OF 950 PM WEDNESDAY...
THE ISOLATED LATE-AFTERNOON STORMS NEAR AND NORTH OF THE TRIAD
FORMED IN AN ENVIRONMENT WITH HIGH INSTABILITY BUT MARGINAL DEEP
LAYER SHEAR WITH A STABLE POCKET ALOFT AROUND 700 MB WHICH LIMITED
EXTENT. THESE HAVE LEFT BEHIND A BATCH OF MID/HIGH CLOUDS WHICH
SHOULD DRIFT SE OUT OF THE CWA OVERNIGHT. WE SHOULD STAY MOSTLY IN
THE "CALM BEFORE THE STORM" TONIGHT... ALTHOUGH THERE REMAINS A
CONCERN FOR WEAK LATE NIGHT CONVECTION. THE LATEST SURFACE MAP SHOWS
A WAVY NEARLY STATIONARY FRONT STRETCHING FROM A LOW OVER NE IA
ACROSS CHICAGOLAND AND THE SRN BORDER OF MI THROUGH PA TO
DELAWARE... WITH WEAK TROUGHING SOUTHWARD THROUGH NC. WIDESPREAD
STRONG TO SEVERE STORMS -- PROMPTED IN PART BY A POTENT VORTICITY
MAX DROPPING INTO IA -- TRACKED ALONG AND EITHER SIDE OF THIS
FRONT... AND IT IS THE CONVECTION NOW OVER OH THAT IS OF CONCERN TO
US OVERNIGHT. THE WRF-ARW TAKES THIS ACTIVITY EASTWARD AS A MCS
THROUGH DC AND NJ... AND THE HRRR IS SIMILAR BUT ACTUALLY BRUSHES
ACROSS FAR NORTH CENTRAL AND NORTHEAST NC LATE TONIGHT. DESPITE THE
PERSISTENCE OF STRONG INSTABILITY (MLCAPE 3000-4000 J/KG)... THIS
MAY BE A LITTLE AMBITIOUS GIVEN THE ANTICYCLONIC MID LEVEL FLOW OVER
THE CAROLINAS AND QUICKLY DEVELOPING CINH... BUT A MORE PLAUSIBLE
SCENARIO (INDICATED BY PREVIOUS HRRR RUNS) IS A MORE
NORTHWARD-TRACKING MCS AND THE DEPOSITION OF AN OUTFLOW BOUNDARY
SOUTHWARD INTO NORTHEAST NC LATE TONIGHT... WHICH WOULD HAVE
RAMIFICATIONS TOMORROW IN TERMS OF ENHANCEMENT OF OR FOCUS FOR
STORMS. THE OH STORMS HAVE BEEN LARGELY DISCRETE WITH FEW SIGNS OF
IMMINENT CONGEALMENT INTO A SQUALL LINE... AS HAS BEEN THE CASE WITH
THE STORMS FURTHER UPSTREAM AS WELL OVER IL/IN (AS NOTED BY SPC IN
ITS LATEST OUTLOOK)... WHICH LOWERS THE CHANCE THAN NC WILL BE
AFFECTED BY A CONVECTIVE LINE OVERNIGHT. THUS... WILL LEAVE OUT POPS
OVERNIGHT... BUT HOLD AT 14 PERCENT IN THE NORTH. BUT WILL CERTAINLY
HAVE TO KEEP AN EYE ON THE RADAR OVERNIGHT FOR ANY DISCRETE ISOLATED
CELLS THAT CAN POP UP THROUGH THE CAP. WITH SURFACE DEW POINTS NOW
WELL UP INTO THE 70S... EXPECT LOWS TO BE A DEGREE OR TWO WARMER
THAN CURRENTLY FORECASTED... 70-75. -GIH
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
AS OF 315 PM WEDNESDAY...
...SEVERE WEATHER POSSIBLE THURSDAY AFTERNOON AND EVENING...
A ROBUST SHORT WAVE TROUGH WILL MOVE ACROSS THE OHIO VALLEY ON
THURSDAY AND OFF THE MID ATLANTIC COAST ON THURSDAY EVENING. THE
ASSOCIATED SURFACE LOW WILL DEEPEN AS IT MOVES ACROSS THE
APPALACHIANS INTO THE NORTHERN CHESAPEAKE BAY AS THE TRAILING COLD
FRONT SLIDES ACROSS CENTRAL NC. THE AIR MASS AHEAD OF THE FRONT IS
EXPECTED TO BE MODERATELY TO NEARLY STRONGLY UNSTABLE WITH MID-LEVEL
LAPSE RATES OF AROUND 7 DEG C/KM. EXPECT A STOUT SOUTHWEST TO
WESTERLY LOW LEVEL FLOW DURING THE AFTERNOON WITH STRONGER MID LEVEL
WIND MAX OF 50+ KTS ROTATING INTO THE REGION. EXPECT ISOLATED
CONVECTION TO FIRE ACROSS THE WESTERN PIEDMONT DURING THE MID
AFTERNOON...INITIATED IN PART BY THE APPROACHING SFC TROUGH BUT
LIMITED IN COVERAGE FROM A NOTABLE DOWNSLOPE DRYING FLOW OFF THE
MOUNTAINS. CONVECTION IS LIKELY TO INTENSIFY AND SLOWLY GROW IN
COVERAGE AS IT APPROACHES THE US 1 CORRIDOR DURING THE LATE
AFTERNOON IN THE FORM OF ORGANIZED CONVECTION INCLUDING POSSIBLE
SUPERCELLS WITH DAMAGING WINDS AND POSSIBLY HAIL. AS THE CONVECTION
REACHES A MORE MOIST ENVIRONMENT THE CONVECTION WILL LIKELY GROW
UPSCALE INTO A SQUALL LINE AND BOWING FEATURE AS IT MOVES ACROSS THE
COASTAL PLAIN WITH THE POTENTIAL FOR WIDESPREAD DAMAGING WINDS. THE
GREATEST THREAT OF SEVERE WEATHER WILL LIKELY BE IN THE COASTAL
PLAIN BETWEEN 4 AND 9 WITH WIDESPREAD DAMAGING WINDS POSSIBLE.
HIGH TEMPERATURES ARE EXPECTED TO CLIMB INTO LOWER 90S NORTHWEST TO
MID 90S SOUTHEAST. THESE TEMPERATURES COMBINED WITH DEWPOINTS IN THE
MID TO POSSIBLY UPPER 60S WILL RESULT IN HEAT INDEX VALUES AROUND OR
JUST EXCEEDING 100 DEGREES. WILL ACCORDINGLY MENTION THIS IN THE
HWO. BEHIND THE COLD FRONT...LOW TEMPERATURES WILL FALL INTO THE
LOWER TO MID 60S BY FRIDAY MORNING. -BLAES
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 220 AM THURSDAY...
A DRY WEEKEND FOLLOWED BY INCREASING CHANCE OF MAINLY DIURNAL
SHOWERS AND THUNDERSTORMS MON-TUE NEXT WEEK.
MODELS ARE IN EXCELLENT AGREEMENT IN THE MID-UPPER LEVEL FLOW
PATTERN OVER THE EASTERN UNITED STATES THIS WEEKEND INTO MID NEXT
WEEK. NORTH CAROLINA WILL BE ON THE BACK SIDE OF THE DEPARTING
TROUGH OUT INTO THE ATLANTIC SATURDAY. STRONG SUBSIDENCE WILL
COMBINE WITH A STRONG SURFACE HIGH PRESSURE TRACKING FROM THE GREAT
LAKES TO OFFSHORE OF THE MID-ATLANTIC COAST SAT-SUN TO BRING A MILD
TO WARM AND DRY WEEKEND. LOWS WILL BE QUITE PLEASANT FOR MID JUNE
WITH READINGS IN THE 55-60 RANGE NORTH... AND 60-65 SOUTH SATURDAY
MORNING... MODIFYING TO THE LOWER TO MID 60S SUNDAY MORNING. GIVEN
THE 30 YEAR AVERAGES WILL BE IN THE MID TO UPPER 60S SAT-SUN...
THESE LOWS WILL BE A GOOD 5-10 DEGREES BELOW NORMAL. HIGHS BOTH DAYS
SHOULD REACH THE LOWER TO MID 80S... WITH MORE IN THE WAY OF MID 80S
SUNDAY.
MON-WED... A MID-UPPER LEVEL TROUGH IS EXPECTED TO TRACK FROM THE
UPPER MIDWEST TO OFF THE MID-ATLANTIC COAST AGAIN THIS PERIOD. THE
MAIN STORM TRACK IS AGAIN FORECAST WITH MODERATE TO HIGH CONFIDENCE
TO BE FROM THE UPPER MIDWEST SE TO THE OHIO VALLEY THEN OFF THE
MID-ATLANTIC COAST. THIS WOULD PLACE AREAS TO OUR NORTH AT THE
GREATEST RISK OF SEVERE STORMS. HOWEVER... THE TRAILING COLD FRONT
IS EXPECTED TO ARRIVE LATE TUESDAY AND TUESDAY NIGHT BRINGING
ANOTHER ROUND OF ENHANCED THUNDERSTORM POTENTIAL FOR OUR REGION. THE
CHANCES OF DIURNAL CONVECTION SHOULD INCREASE AS EARLY AS MONDAY
AFTERNOON/EVENING AS SSW FLOW INCREASES THE OVERALL MOISTURE PROFILE
ACROSS THE APPALACHIANS AND NC. HOWEVER... THE HIGHEST PROBABILITY OF
THUNDERSTORMS APPEARS TO BE TUESDAY AFTERNOON AND NIGHT AS THE
MID/UPPER TROUGH AND COLD FRONT APPROACH DURING OR AFTER PEAK
HEATING. THE CHANCE OF SHOWERS AND THUNDERSTORMS MAY CONTINUE...
ESPECIALLY IN THE SE ON WED AS THE FRONT APPEARS TO SLOW DOWN AND
POSSIBLY STALL NEAR SE NC ON WED. HIGHS MONDAY SHOULD BE 85-90 AFTER
LOWS OF 65-70. LOWS TUESDAY 70-74 WITH HIGHS IN THE MID TO UPPER
80S. WEDNESDAY SHOULD BE A BIT COOLER STILL... WITH LOWS 65-70.
HIGHS IN THE LOWER TO MID 80S WITH VARIABLY CLOUDY SKIES.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 145 AM THURSDAY...
24-HR TAF PERIOD:
VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH 18Z THIS AFTERNOON.
SOUTHWEST WINDS AT 5-10 KT THIS MORNING WILL INCREASE TO 12-17 KT
SUSTAINED WITH GUSTS UP TO 23-28 KT THIS AFTERNOON AS THE PRESSURE
GRADIENT TIGHTENS IN ADVANCE OF A COLD FRONT APPROACHING FROM THE
WEST. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED
TO DEVELOP BY MID TO LATE AFTERNOON (18-22Z) ALONG AND AHEAD OF THE
FRONT...MOVING RAPIDLY EASTWARD AND BECOMING MORE WIDESPREAD BY LATE
AFTERNOON AND EARLY EVENING AS THEY TRACK INTO THE COASTAL PLAIN.
DUE TO AN UNUSUALLY FAVORABLE ENVIRONMENT IN PLACE...ANY STORMS THAT
DEVELOP WILL BE CAPABLE OF PRODUCING SURFACE WIND GUSTS AS HIGH AS
50-60 KT AND QUARTER TO GOLFBALL SIZE HAIL. THE THREAT FOR SEVERE
STORMS WILL BE GREATEST AT THE RDU/FAY/RWI TERMINALS BETWEEN 18Z
THIS AFTERNOON AND 03Z TONIGHT. WINDS WILL SHIFT TO THE NW/NNW AT
10-15 KT IN THE WAKE OF THE COLD FRONT BY THE END OF THE TAF
PERIOD...MOST LIKELY BETWEEN 03-06Z FRIDAY.
LOOKING AHEAD:
VFR CONDITIONS WILL PREVAIL IN THE WAKE OF THE COLD FRONT FRIDAY
THROUGH MOST IF NOT ALL OF THE WEEKEND. EXPECT AN INCREASING CHANCE
FOR SHOWERS AND THUNDERSTORMS SUNDAY NIGHT-TUESDAY IN ADVANCE OF
ANOTHER COLD FRONT APPROACHING THE REGION FROM THE WEST. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...HARTFIELD
SHORT TERM...BLAES
LONG TERM...PWB
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
212 AM EDT THU JUN 13 2013
.SYNOPSIS...
AN UNSEASONABLY STRONG LOW PRESSURE SYSTEM AND ASSOCIATED COLD FRONT
WILL TRACK QUICKLY EAST ACROSS THE MID-ATLANTIC AND CAROLINAS THIS
AFTERNOON AND EVENING. HIGH PRESSURE WILL BUILD OVER THE REGION IN
THE WAKE OF THE FRONT FRIDAY INTO THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
AS OF 950 PM WEDNESDAY...
THE ISOLATED LATE-AFTERNOON STORMS NEAR AND NORTH OF THE TRIAD
FORMED IN AN ENVIRONMENT WITH HIGH INSTABILITY BUT MARGINAL DEEP
LAYER SHEAR WITH A STABLE POCKET ALOFT AROUND 700 MB WHICH LIMITED
EXTENT. THESE HAVE LEFT BEHIND A BATCH OF MID/HIGH CLOUDS WHICH
SHOULD DRIFT SE OUT OF THE CWA OVERNIGHT. WE SHOULD STAY MOSTLY IN
THE "CALM BEFORE THE STORM" TONIGHT... ALTHOUGH THERE REMAINS A
CONCERN FOR WEAK LATE NIGHT CONVECTION. THE LATEST SURFACE MAP SHOWS
A WAVY NEARLY STATIONARY FRONT STRETCHING FROM A LOW OVER NE IA
ACROSS CHICAGOLAND AND THE SRN BORDER OF MI THROUGH PA TO
DELAWARE... WITH WEAK TROUGHING SOUTHWARD THROUGH NC. WIDESPREAD
STRONG TO SEVERE STORMS -- PROMPTED IN PART BY A POTENT VORTICITY
MAX DROPPING INTO IA -- TRACKED ALONG AND EITHER SIDE OF THIS
FRONT... AND IT IS THE CONVECTION NOW OVER OH THAT IS OF CONCERN TO
US OVERNIGHT. THE WRF-ARW TAKES THIS ACTIVITY EASTWARD AS A MCS
THROUGH DC AND NJ... AND THE HRRR IS SIMILAR BUT ACTUALLY BRUSHES
ACROSS FAR NORTH CENTRAL AND NORTHEAST NC LATE TONIGHT. DESPITE THE
PERSISTENCE OF STRONG INSTABILITY (MLCAPE 3000-4000 J/KG)... THIS
MAY BE A LITTLE AMBITIOUS GIVEN THE ANTICYCLONIC MID LEVEL FLOW OVER
THE CAROLINAS AND QUICKLY DEVELOPING CINH... BUT A MORE PLAUSIBLE
SCENARIO (INDICATED BY PREVIOUS HRRR RUNS) IS A MORE
NORTHWARD-TRACKING MCS AND THE DEPOSITION OF AN OUTFLOW BOUNDARY
SOUTHWARD INTO NORTHEAST NC LATE TONIGHT... WHICH WOULD HAVE
RAMIFICATIONS TOMORROW IN TERMS OF ENHANCEMENT OF OR FOCUS FOR
STORMS. THE OH STORMS HAVE BEEN LARGELY DISCRETE WITH FEW SIGNS OF
IMMINENT CONGEALMENT INTO A SQUALL LINE... AS HAS BEEN THE CASE WITH
THE STORMS FURTHER UPSTREAM AS WELL OVER IL/IN (AS NOTED BY SPC IN
ITS LATEST OUTLOOK)... WHICH LOWERS THE CHANCE THAN NC WILL BE
AFFECTED BY A CONVECTIVE LINE OVERNIGHT. THUS... WILL LEAVE OUT POPS
OVERNIGHT... BUT HOLD AT 14 PERCENT IN THE NORTH. BUT WILL CERTAINLY
HAVE TO KEEP AN EYE ON THE RADAR OVERNIGHT FOR ANY DISCRETE ISOLATED
CELLS THAT CAN POP UP THROUGH THE CAP. WITH SURFACE DEW POINTS NOW
WELL UP INTO THE 70S... EXPECT LOWS TO BE A DEGREE OR TWO WARMER
THAN CURRENTLY FORECASTED... 70-75. -GIH
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
AS OF 315 PM WEDNESDAY...
...SEVERE WEATHER POSSIBLE THURSDAY AFTERNOON AND EVENING...
A ROBUST SHORT WAVE TROUGH WILL MOVE ACROSS THE OHIO VALLEY ON
THURSDAY AND OFF THE MID ATLANTIC COAST ON THURSDAY EVENING. THE
ASSOCIATED SURFACE LOW WILL DEEPEN AS IT MOVES ACROSS THE
APPALACHIANS INTO THE NORTHERN CHESAPEAKE BAY AS THE TRAILING COLD
FRONT SLIDES ACROSS CENTRAL NC. THE AIR MASS AHEAD OF THE FRONT IS
EXPECTED TO BE MODERATELY TO NEARLY STRONGLY UNSTABLE WITH MID-LEVEL
LAPSE RATES OF AROUND 7 DEG C/KM. EXPECT A STOUT SOUTHWEST TO
WESTERLY LOW LEVEL FLOW DURING THE AFTERNOON WITH STRONGER MID LEVEL
WIND MAX OF 50+ KTS ROTATING INTO THE REGION. EXPECT ISOLATED
CONVECTION TO FIRE ACROSS THE WESTERN PIEDMONT DURING THE MID
AFTERNOON...INITIATED IN PART BY THE APPROACHING SFC TROUGH BUT
LIMITED IN COVERAGE FROM A NOTABLE DOWNSLOPE DRYING FLOW OFF THE
MOUNTAINS. CONVECTION IS LIKELY TO INTENSIFY AND SLOWLY GROW IN
COVERAGE AS IT APPROACHES THE US 1 CORRIDOR DURING THE LATE
AFTERNOON IN THE FORM OF ORGANIZED CONVECTION INCLUDING POSSIBLE
SUPERCELLS WITH DAMAGING WINDS AND POSSIBLY HAIL. AS THE CONVECTION
REACHES A MORE MOIST ENVIRONMENT THE CONVECTION WILL LIKELY GROW
UPSCALE INTO A SQUALL LINE AND BOWING FEATURE AS IT MOVES ACROSS THE
COASTAL PLAIN WITH THE POTENTIAL FOR WIDESPREAD DAMAGING WINDS. THE
GREATEST THREAT OF SEVERE WEATHER WILL LIKELY BE IN THE COASTAL
PLAIN BETWEEN 4 AND 9 WITH WIDESPREAD DAMAGING WINDS POSSIBLE.
HIGH TEMPERATURES ARE EXPECTED TO CLIMB INTO LOWER 90S NORTHWEST TO
MID 90S SOUTHEAST. THESE TEMPERATURES COMBINED WITH DEWPOINTS IN THE
MID TO POSSIBLY UPPER 60S WILL RESULT IN HEAT INDEX VALUES AROUND OR
JUST EXCEEDING 100 DEGREES. WILL ACCORDINGLY MENTION THIS IN THE
HWO. BEHIND THE COLD FRONT...LOW TEMPERATURES WILL FALL INTO THE
LOWER TO MID 60S BY FRIDAY MORNING. -BLAES
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AS OF 240 PM WEDNESDAY...
CONDITIONS WILL DRY OUT AND COOL DOWN BEHIND THE DEPARTING SYSTEM
FOR THE END OF THE WORK WEEK AND EARLY WEEKEND. THE STRONG MID/UPPER
LEVEL TROUGH WILL BE CROSSING THE AREA DURING THE DAY ON FRIDAY AND
VERY WELL COULD PRODUCE A COUPLE OF SHOWERS OR SOME SPRINKLES.
HOWEVER...THE DEEP MOISTURE WILL HAVE MOVED OFFSHORE...SO AM NOT
EXPECTING ENOUGH COVERAGE TO PUT ANY MENTION IN THE FORECAST. IF
ANYTHING DOES DEVELOP...IT SHOULD BE ACROSS THE EASTERN THIRD OF THE
FORECAST AREA WHERE SOME RESIDUAL MOISTURE (PWAT VALUES NEAR AN
INCH) MAY RESIDE.
THEN...SURFACE HIGH PRESSURE AND RISING HEIGHTS ALOFT (ALTHOUGH THE
CORE OF THE MID/UPPER HIGH WILL REMAIN WEST OF OF THE REGION BEFORE
FLATTENING OUT BY THE LATTER HALF OF THE WEEKEND) WILL LEAD TO MORE
SUNSHINE AND MOSTLY DRY CONDITIONS THROUGH MUCH OF THE WEEKEND.
TEMPS SHOULD STAY BELOW NORMAL (HIGHS IN THE LOW/MID 80S...OVERNIGHT
LOWS IN THE LOW 60S...WITH EVEN SOME UPPER 50S POSSIBLE) FRIDAY AND
SATURDAY...BEFORE MODIFYING ON SUNDAY AS THE SURFACE HIGH SHIFTS
OFFSHORE. THE NEXT SYSTEM LOOKS TO APPROACH THE REGION EARLY NEXT
WEEK...BUT THERE ARE STILL SOME TIMING/STRENGTH ISSUES BETWEEN THE
MODELS. AT THIS TIME...IT APPEARS A FRONT WILL MOVE THROUGH THE AREA
SOMETIME ON TUESDAY...WHICH IS WHEN THE BEST CHANCE OF RAIN WILL BE
FOCUSED. HOWEVER...INCREASING SOUTHWESTERLY FLOW WILL DRIVE OUR
MOISTURE BACK UP AND THEREFORE WILL HAVE SLIGHT CHANCE POPS FOR
MONDAY. TEMPS WILL BE NEAR NORMAL FOR THE BEGINNING ON NEXT WEEK.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 145 AM THURSDAY...
24-HR TAF PERIOD:
VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH 18Z THIS AFTERNOON.
SOUTHWEST WINDS AT 5-10 KT THIS MORNING WILL INCREASE TO 12-17 KT
SUSTAINED WITH GUSTS UP TO 23-28 KT THIS AFTERNOON AS THE PRESSURE
GRADIENT TIGHTENS IN ADVANCE OF A COLD FRONT APPROACHING FROM THE
WEST. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED
TO DEVELOP BY MID TO LATE AFTERNOON (18-22Z) ALONG AND AHEAD OF THE
FRONT...MOVING RAPIDLY EASTWARD AND BECOMING MORE WIDESPREAD BY LATE
AFTERNOON AND EARLY EVENING AS THEY TRACK INTO THE COASTAL PLAIN.
DUE TO AN UNUSUALLY FAVORABLE ENVIRONMENT IN PLACE...ANY STORMS THAT
DEVELOP WILL BE CAPABLE OF PRODUCING SURFACE WIND GUSTS AS HIGH AS
50-60 KT AND QUARTER TO GOLFBALL SIZE HAIL. THE THREAT FOR SEVERE
STORMS WILL BE GREATEST AT THE RDU/FAY/RWI TERMINALS BETWEEN 18Z
THIS AFTERNOON AND 03Z TONIGHT. WINDS WILL SHIFT TO THE NW/NNW AT
10-15 KT IN THE WAKE OF THE COLD FRONT BY THE END OF THE TAF
PERIOD...MOST LIKELY BETWEEN 03-06Z FRIDAY.
LOOKING AHEAD:
VFR CONDITIONS WILL PREVAIL IN THE WAKE OF THE COLD FRONT FRIDAY
THROUGH MOST IF NOT ALL OF THE WEEKEND. EXPECT AN INCREASING CHANCE
FOR SHOWERS AND THUNDERSTORMS SUNDAY NIGHT-TUESDAY IN ADVANCE OF
ANOTHER COLD FRONT APPROACHING THE REGION FROM THE WEST. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...HARTFIELD
SHORT TERM...BLAES
LONG TERM...KRR
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS BISMARCK ND
948 PM CDT FRI JUN 14 2013
.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 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 948 PM CDT FRI JUN 14 2013
VFR CONDITIONS ALL TERMINALS THROUGH THE 00Z TAF PERIOD. WINDS
WILL DECREASE THROUGH 03-04Z AND REMAIN LIGHT TONIGHT. INCREASING
WEST WIND GUSTING 25-30KTS 15Z SATURDAY THROUGH SATURDAY
AFTERNOON.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...NH
SHORT TERM...WAA
LONG TERM...AYD
AVIATION...NH
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
718 PM CDT FRI JUN 14 2013
CORRECTED FOR DIRECTIONAL ERROR IN THE UPDATE SECTION
.UPDATE...
ISSUED AT 718 PM CDT FRI JUN 14 2013
STILL WAITING TO SEE IF ANY STRONG THUNDERSTORMS CAN DEVELOP. THE
SURFACE BOUNDARY IS LOCATED JUST WEST OF THE FA...WITH MLCAPE
AROUND 1000 J/KG ALONG MUCH OF THIS FEATURE...AND NEAR 2000 J/KG
CLOSER TO THE SOUTH DAKOTA BORDER. INITIATION AND COVERAGE OF
STORMS THIS EVENING IS UNCERTAIN. ALTHOUGH SPC MESO-ANALYSIS
INDICATES THAT THE CAP HAD ERODED A FEW HOURS AGO...LAP ANALYSIS
INDICATES THAT THE MLCIN AT 22Z WAS AROUND 100 J/KG...AND HAS
LOWERED TO AROUND 10 J/KG AT 23Z. EXPECT INITIATION WITHIN THE
NEXT 1-2 HOURS IF THERE WILL BE ANYTHING. THE HRRR DOES SHOW THE
POTENTIAL FOR A STRONG STORM OR TWO ACROSS THE SOUTHWEST
FA...WHERE INSTABILITY IS STRONGER...AND SKY IS CLEAR JUST TO THE
WEST. OTHERWISE...MODELS INDICATE 850MB WARM AIR ADVECTION WILL
INCREASE ALONG AND EAST OF THE VALLEY THIS EVENING...WITH SHOWERS
AND THUNDERSTORMS INCREASING IN COVERAGE...ESPECIALLY ACROSS THE
NE FA. THESE STORMS WOULD LIKELY BE AHEAD OF THE STRONGER
INSTABILITY...WHICH WOULD LIMIT SEVERE POTENTIAL. MODIFIED THE POP
AND WX GRID TO ACCOUNT FOR CURRENT ACTIVITY AND THE 20Z HRRR.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 330 PM CDT FRI JUN 14 2013
FORECAST CHALLENGE CONCERNS MAINLY NEAR TERM THUNDERSTORM COVERAGE
AND SEVERE POTENTIAL. MODELS OK WITH MAIN FEATURES BUT DIFFER ON
CONVECTIVE QPF AND WILL USE BLEND.
SURFACE BOUNDARY PUSHING INTO CENTRAL DAKOTAS WITH WATER VAPOR
IMAGERY INDICATING SECONDARY WAVE INTO WESTERN DAKOTAS. SOME
MODEST CAPE/INSTABILITY...SHEAR AND 850MB MOISTURE TRANSPORT ALONG AND
AHEAD OF FRONT. THINNING CLOUDS HAVE ALLOWED FOR MORE SOLAR
HOWEVER TEMPERATURES LIKELY TO HOLD SHORT OF CONVECTIVE THRESHOLDS.
CONS FOR DEEP SEVERE POTENTIAL IS STILL QUITE A BIT OF CONVECTIVE
INHIBITION WITH WARM MID LEVEL TEMPERATURES. MODELS HAVE BEEN OVER
FORECASTING DEW POINT TEMPERATURES BY 5 TO 10 DEGREES. THIS
POSSIBLY A RESULT FROM OUR DELAY IN EVAPOTRANSPIRATION WITH SLOW
EMERGENCE OF CROPS. LASTLY LEAD WAVE LIFTING THROUGH NORTHERN FA
AND SUBSIDENCE IN ITS WAKE MAY LIMIT CONVECTIVE INITIATION
POTENTIAL. WITH UNCERTAINTIES REMAINING DID BACK OFF ON LIKELY
POPS FOR A GOOD SHARE OF THE EVENING. BOUNDARY TO PROPAGATE EAST
OVERNIGHT AND ANY CONVECTION WHICH DOES DEVELOP SHOULD EXIT FA SOON
AFTER MIDNIGHT. DEW POINTS UPSTREAM BEHIND BOUNDARY SIMILAR TO CURRENT
VALUES SO OVERNIGHT LOWS SHOULD RANGE THROUGH THE 50S.
COLUMN DRIES NICELY BEHIND BOUNDARY AS SURFACE HIGH PRESSURE.
SOLAR AND SURFACE WESTERLY FLOW SHOULD ALLOW TEMPERATURES TO
RECOVER TO SEASONAL AVERAGES.
QUIET SATURDAY NIGHT WITH SEASONAL MINIMUMS TO CONTINUE.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 330 PM CDT FRI JUN 14 2013
RESPECTABLE COLD FRONT DROPS THROUGH FA ON SUNDAY. MODEST
INSTABILITY AHEAD OF BOUNDARY COULD LEAD TO SOME AFTERNOON
CONVECTION AND MAINTAINED POPS ACROSS ROUGHLY NORTH HALF OF FA.
COOLER TEMPERATURES WILL BE FELT MOST ACROSS NORTHERN FA IN
STRONGER COLD ADVECTION DURING THE DAY. FAR SOUTH MAY STILL SEE
TEMPERATURES NEAR AVERAGE.
UPPER LEVEL RIDGE WILL KEEP FIRST PART OF THE WORK WEEK
DRY...HOWEVER THIS FEATURE WILL BEGIN TO SHIFT EAST FOR THE SECOND
HALF OF THE WEEK AND BRING AN INCREASED CHANCE FOR TSTMS THU AND
FRI. STRONGEST SOUTHERLY FLOW AND THERMAL RIDGE SHOULD BE WEST OF
REGION...AND NEAR OR SLIGHTLY ABOVE NORMAL TEMPS ARE EXPECTED.
WARMEST DAYS SHOULD BE IN THE MIDDLE OF THE WEEK...RIGHT AROUND THE
80 MARK FOR MOST OF THE AREA.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 650 PM CDT FRI JUN 14 2013
VFR CIGS THROUGH THE EVENING WITH CLEAR SKIES MOVING INTO THE
REGION FROM WEST TO EAST BY SATURDAY MORNING. THE MAIN CONCERN WILL
BE THUNDER CHANCES. COVERAGE IS UNCERTAIN...AND ATTEMPTED TO LIMIT
THE TEMPO GROUPS TO THE MOST LIKELY TIME PERIOD.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...TG
SHORT TERM...VOELKER
LONG TERM...SPEICHER/VOELKER
AVIATION...TG
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
650 PM CDT FRI JUN 14 2013
.UPDATE...
ISSUED AT 650 PM CDT FRI JUN 14 2013
STILL WAITING TO SEE IF ANY STRONG THUNDERSTORMS CAN DEVELOP. THE
SURFACE BOUNDARY IS LOCATED JUST WEST OF THE FA...WITH MLCAPE
AROUND 1000 J/KG ALONG MUCH OF THIS FEATURE...AND NEAR 2000 J/KG
CLOSER TO THE SOUTH DAKOTA BORDER. INITIATION AND COVERAGE OF
STORMS THIS EVENING IS UNCERTAIN. ALTHOUGH SPC MESO-ANALYSIS
INDICATES THAT THE CAP HAD ERODED A FEW HOURS AGO...LAP ANALYSIS
INDICATES THAT THE MLCIN AT 22Z WAS AROUND 100 J/KG...AND HAS
LOWERED TO AROUND 10 J/KG AT 23Z. EXPECT INITIATION WITHIN THE
NEXT 1-2 HOURS IF THERE WILL BE ANYTHING. THE HRRR DOES SHOW THE
POTENTIAL FOR A STRONG STORM OR TWO ACROSS THE SOUTHWEST
FA...WHERE INSTABILITY IS STRONGER...AND SKY IS CLEAR JUST TO THE
WEST. OTHERWISE...MODELS INDICATE 850MB WARM AIR ADVECTION WILL
INCREASE ALONG AND EAST OF THE VALLEY THIS EVENING...WITH SHOWERS
AND THUNDERSTORMS INCREASING IN COVERAGE...ESPECIALLY ACROSS THE
NW FA. THESE STORMS WOULD LIKELY BE AHEAD OF THE STRONGER
INSTABILITY...WHICH WOULD LIMIT SEVERE POTENTIAL. MODIFIED THE POP
AND WX GRID TO ACCOUNT FOR CURRENT ACTIVITY AND THE 20Z HRRR.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 330 PM CDT FRI JUN 14 2013
FORECAST CHALLENGE CONCERNS MAINLY NEAR TERM THUNDERSTORM COVERAGE
AND SEVERE POTENTIAL. MODELS OK WITH MAIN FEATURES BUT DIFFER ON
CONVECTIVE QPF AND WILL USE BLEND.
SURFACE BOUNDARY PUSHING INTO CENTRAL DAKOTAS WITH WATER VAPOR
IMAGERY INDICATING SECONDARY WAVE INTO WESTERN DAKOTAS. SOME
MODEST CAPE/INSTABILITY...SHEAR AND 850MB MOISTURE TRANSPORT ALONG AND
AHEAD OF FRONT. THINNING CLOUDS HAVE ALLOWED FOR MORE SOLAR
HOWEVER TEMPERATURES LIKELY TO HOLD SHORT OF CONVECTIVE THRESHOLDS.
CONS FOR DEEP SEVERE POTENTIAL IS STILL QUITE A BIT OF CONVECTIVE
INHIBITION WITH WARM MID LEVEL TEMPERATURES. MODELS HAVE BEEN OVER
FORECASTING DEW POINT TEMPERATURES BY 5 TO 10 DEGREES. THIS
POSSIBLY A RESULT FROM OUR DELAY IN EVAPOTRANSPIRATION WITH SLOW
EMERGENCE OF CROPS. LASTLY LEAD WAVE LIFTING THROUGH NORTHERN FA
AND SUBSIDENCE IN ITS WAKE MAY LIMIT CONVECTIVE INITIATION
POTENTIAL. WITH UNCERTAINTIES REMAINING DID BACK OFF ON LIKELY
POPS FOR A GOOD SHARE OF THE EVENING. BOUNDARY TO PROPAGATE EAST
OVERNIGHT AND ANY CONVECTION WHICH DOES DEVELOP SHOULD EXIT FA SOON
AFTER MIDNIGHT. DEW POINTS UPSTREAM BEHIND BOUNDARY SIMILAR TO CURRENT
VALUES SO OVERNIGHT LOWS SHOULD RANGE THROUGH THE 50S.
COLUMN DRIES NICELY BEHIND BOUNDARY AS SURFACE HIGH PRESSURE.
SOLAR AND SURFACE WESTERLY FLOW SHOULD ALLOW TEMPERATURES TO
RECOVER TO SEASONAL AVERAGES.
QUIET SATURDAY NIGHT WITH SEASONAL MINIMUMS TO CONTINUE.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 330 PM CDT FRI JUN 14 2013
RESPECTABLE COLD FRONT DROPS THROUGH FA ON SUNDAY. MODEST
INSTABILITY AHEAD OF BOUNDARY COULD LEAD TO SOME AFTERNOON
CONVECTION AND MAINTAINED POPS ACROSS ROUGHLY NORTH HALF OF FA.
COOLER TEMPERATURES WILL BE FELT MOST ACROSS NORTHERN FA IN
STRONGER COLD ADVECTION DURING THE DAY. FAR SOUTH MAY STILL SEE
TEMPERATURES NEAR AVERAGE.
UPPER LEVEL RIDGE WILL KEEP FIRST PART OF THE WORK WEEK
DRY...HOWEVER THIS FEATURE WILL BEGIN TO SHIFT EAST FOR THE SECOND
HALF OF THE WEEK AND BRING AN INCREASED CHANCE FOR TSTMS THU AND
FRI. STRONGEST SOUTHERLY FLOW AND THERMAL RIDGE SHOULD BE WEST OF
REGION...AND NEAR OR SLIGHTLY ABOVE NORMAL TEMPS ARE EXPECTED.
WARMEST DAYS SHOULD BE IN THE MIDDLE OF THE WEEK...RIGHT AROUND THE
80 MARK FOR MOST OF THE AREA.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 650 PM CDT FRI JUN 14 2013
VFR CIGS THROUGH THE EVENING WITH CLEAR SKIES MOVING INTO THE
REGION FROM WEST TO EAST BY SATURDAY MORNING. THE MAIN CONCERN WILL
BE THUNDER CHANCES. COVERAGE IS UNCERTAIN...AND ATTEMPTED TO LIMIT
THE TEMPO GROUPS TO THE MOST LIKELY TIME PERIOD.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...TG
SHORT TERM...VOELKER
LONG TERM...SPEICHER/VOELKER
AVIATION...TG
AREA FORECAST DISCUSSION
NWS BISMARCK ND
101 AM CDT THU JUN 13 2013
.UPDATE...
ISSUED AT 101 AM CDT THU JUN 13 2013
CURRENTLY...A SURFACE HIGH PRESSURE AXIS EXTENDED FROM THE MAIN HIGH
CENTER IN THE HUDSON BAY REGION ACROSS MANITOBA AND INTO CENTRAL
NORTH DAKOTA. THE AXIS IN NORTH DAKOTA WAS CENTERED AROUND THE
TURTLE MOUNTAINS TO BETWEEN BISMARCK AND JAMESTOWN. WINDS EAST OF
THE AXIS WERE FROM THE NORTH/NORTHWEST...WHILE LIGHT SOUTHEAST WINDS
WERE OCCURRING WEST OF THE AXIS - ACROSS MAINLY THE WESTERN HALF OF
THE STATE. MOISTURE CONVERGENCE JUST OFF THE SURFACE TAKING PLACE
OVER THE WESTERN HALF OF THE STATE WITH THE SOUTHEAST WINDS.
PREVIOUS FORECAST HAD MENTION OF FOG IN THE JAMES RIVER VALLEY.
DECIDED TO EXPAND THIS MENTION WESTWARD ACROSS MOST OF CENTRAL NORTH
DAKOTA IN THE VICINITY OF THE HIGH AXIS CENTER.
OTHERWISE CURRENT FORECAST IS ON TRACK. KEPT THE SLIGHT CHANCE
MENTION OF THUNDERSTORMS IN THE FAR SOUTHWEST...WITH CURRENT TRENDS
SHOWING CONVECTION IN FAR NORTHWESTERN SOUTH DAKOTA. MID LEVEL LAPSE
RATES IN THE SOUTHWEST WOULD SUPPORT CONVECTION IF IT GOT
GOING...BUT CAPE IS VIRTUALLY ZERO AND NOT CONCERNED ABOUT ANY
STRONG STORMS AT ALL TONIGHT.
UPDATE ISSUED AT 946 PM CDT WED JUN 12 2013
SHOWERS AND THUNDERSTORMS ACROSS EASTERN MONTANA AND NORTHEAST
WYOMING CONTINUE TO STRUGGLE TO MAKE PROGRESS EAST THIS EVENING.
THEY ARE BEING WEAKENED SUBSTANTIALLY AS THEY MIGRATE CLOSER TO
SURFACE HIGH PRESSURE AND A RIDGE AT H5. THE 13.00Z NAM GENERALLY
CAPTURES THIS TREND BY KEEPING THE FORECAST AREA DRY
OVERNIGHT...BUT THERE ARE STILL HINTS AN ISOLATED SHOWER OR STORM
COULD MAKE IT INTO SOUTHWEST NORTH DAKOTA. HAVE KEPT THE SLIGHT
CHANCE POPS IN THE FAR SOUTHWEST...BUT COULD SEE THEM GETTING
PULLED WITH LATER UPDATES IF RADAR TRENDS CONTINUE TO SHOW THE
CONVECTION DIMINISHING AS IT TRIES TO PROGRESS EAST.
UPDATE ISSUED AT 701 PM CDT WED JUN 12 2013
CURRENT FORECAST IS ON TRACK. SHOWERS IN THE FAR EASTERN PORTION
OF THE FORECAST AREA HAVE ENDED...WITH DRY CONDITIONS NOW IN
PLACE.
SHOWERS AND THUNDERSTORMS DEVELOPED IN EASTERN MONTANA THIS
AFTERNOON...AND THEY HAVE BEEN MAKING GRADUAL PROGRESS EAST
TOWARDS SOUTHWEST NORTH DAKOTA. THE LATEST RAP SUGGESTS MOST OF
THE ACTIVITY WILL FALL APART BEFORE REACHING THE FORECAST
AREA...THOUGH IT WILL BE CLOSE. HAVE LEFT THE SLIGHT CHANCES OF
THUNDERSTORMS IN THE FAR SOUTHWEST JUST IN CASE A STRAY SHOWER OR
THUNDERSTORM MAKES IT THAT FAR.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 343 PM CDT WED JUN 12 2013
THERE SHOULD BE NO MAJOR WEATHER CONCERNS FOR THE PERIOD AS NORTH
DAKOTA WILL BE UNDER SYNOPTIC SUBSIDENCE AS A RESULT OF AN UPPER
LEVEL RIDGE OVER THE NORTHERN PLAINS.
FOR THIS AFTERNOON...SCATTERED LIGHT RAIN SHOWERS WILL CONTINUE
TO TAPER OFF TO THE SOUTHEAST. THIS ACTIVITY SHOULD BE OUT OF THE
CWA BY EARLY EVENING.
FOR TONIGHT...CONVECTION OVER MONTANA COULD NOSE ITS WAY INTO
EXTREME SOUTHWESTERN NORTH DAKOTA AFTER MIDNIGHT.
HOWEVER...CONFIDENCE IS LOW IN THIS MATERIALIZING SO ONLY
MENTIONED A SLIGHT CHANCE EXTREME SOUTHWEST TONIGHT.
FURTHERMORE...HIGH PRESSURE IS FORECAST TO CREST ACROSS THE
REGION. THE SURFACE RIDGE AXIS IS EXPECTED TO BE OVER THE JAMES
RIVER VALLEY BY 12Z THURSDAY. GIVEN THE COMBINATION OF LIGHT
WINDS...NEAR SATURATED SURFACE CONDITIONS...AND MOSTLY CLEAR
SKIES...ADDED PATCHY FOG WORDING FROM THE TURTLE MOUNTAIN AREA
SOUTH TO THE JAMES RIVER VALLEY.
FOR THURSDAY...DRY CONDITIONS ARE EXPECTED TO PERSIST ACROSS MOST
OF THE CWA. AN UPPER LEVEL WAVE IN THE SOUTHWESTERLY FLOW ALOFT
MAY SPARK THUNDERSTORM ACTIVITY OVER EASTERN MONTANA THURSDAY
AFTERNOON. SOME OF THIS ACTIVITY COULD MAKE IT INTO WESTERN NORTH
DAKOTA...MAINLY ALONG AND WEST OF HIGHWAY 85. HOWEVER...CONFIDENCE
IS LOW IN THIS MATERIALIZING AS WELL. THEREFORE...ONLY INDICATED
SLIGHT CHANCE FOR THUNDER ALONG AND WEST OF HIGHWAY 85 THURSDAY
AFTERNOON.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 343 PM CDT WED JUN 12 2013
THE HIGHLIGHT OF THE EXTENDED FORECAST IS THE POTENTIAL FOR SEVERE
THUNDERSTORMS THURSDAY NIGHT INTO FRIDAY.
A STRENGTHENING LOW LEVEL JET AHEAD OF DEEPENING LOW PRESSURE INTO
NORTHWEST SOUTH DAKOTA ON THURSDAY NIGHT IS EXPECTED TO LEAD TO A
POTENTIAL ROUND OF ELEVATED CONVECTION. 850 MB CAPE VALUES OF
800-1000 J/KG WITH DEEP LAYER SHEAR OF 40-50 KTS SUPPORT A
POTENTIAL LARGE HAIL THREAT THURSDAY NIGHT ACROSS THE AREA.
HOWEVER...700 MB TEMPERATURES OF 12 C OR GREATER DO ADVECT NORTH
THROUGH THE NIGHT WHICH MAY BE A LIMIT TO HAIL GROWTH POTENTIAL.
ON FRIDAY...AN OCCLUDED FRONT EXTENDED FROM THE NOW FILLING
SURFACE LOW ACROSS NORTH CENTRAL SOUTH DAKOTA THROUGH THE PRIMARY
LOW ACROSS SASKATCHEWAN IS FORECAST TO PROPAGATE INTO CENTRAL
NORTH DAKOTA THROUGH THE AFTERNOON. STILL UNCERTAINTY IN THE EXACT
POSITIONING OF THE FRONT DURING PEAK HEATING...WITH THE 12 UTC
GFS/ECMWF/GEM CLOSER TO HIGHWAY 83...WITH THE 12 UTC NAM AND 15
UTC SREF ON THE EASTERN FRINGES OF THE CWA. THIS DIFFERENCE IN
FRONTAL POSITIONING COMBINED WITH UNCERTAINTY IF SKIES WILL CLEAR
TO DESTABILIZE THE BOUNDARY LAYER LEAD TO UNCERTAINTY IN HOW
WIDESPREAD THE SEVERE THREAT MAY BE ON FRIDAY AFTERNOON AND
EVENING. IF SKIES CAN CLEAR...BOUNDARY LAYER DEWPOINTS OF 65-70 F
AHEAD OF THE FRONT AND SUFFICIENT DEEP LAYER SHEAR ARE FORECAST TO
BE AVAILABLE. THEREAFTER...A DRY BUT WINDY SATURDAY IS FORECAST IN
THE DRY SLOT OF THE UPPER LOW ACROSS SOUTHERN CANADA...WITH A
BREAK IN THE THUNDERSTORM THREAT THROUGH AT LEAST TUESDAY UNDER AN
UPPER LEVEL RIDGE WITH NEAR NORMAL TEMPERATURES ANTICIPATED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 101 AM CDT THU JUN 13 2013
VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THE 06Z TAF PERIOD.
SCATTERED TO BROKEN MID CLOUDS...GENERALLY 12000 FEET OR
ABOVE...CONTINUED ACROSS WESTERN NORTH DAKOTA. EXPECT THESE MID
CLOUDS TO DECREASE BY DAYBREAK. SURFACE HIGH PRESSURE OVER CENTRAL
NORTH DAKOTA WILL BRING LIGHT AND VARIABLE WINDS TO MOST AERODROMES
TONIGHT...AND HAVE ADDED A MENTION OF LIGHT FOG AT KBIS AND KJMS IN
THE VICINITY OF THE SURFACE HIGH AXIS. WINDS WILL BECOME GUSTY FROM
THE SOUTHEAST AFT 15Z ON THURSDAY AS THE HIGH SHIFTS EAST OF THE
REGION.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JV
SHORT TERM...TM
LONG TERM...AYD
AVIATION...JV
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
611 PM EDT THU JUN 13 2013
.SYNOPSIS...
HIGH PRESSURE WILL BUILD SOUTHEAST AND BE OVER THE AREA BY FRIDAY
NIGHT. THE HIGH WILL MOVE TO THE CAROLINA COAST BY SATURDAY NIGHT. A
WARM FRONT WILL LIFT NORTHEAST ACROSS THE AREA SATURDAY NIGHT AND
BECOME NEARLY STATIONARY NORTHEAST OF THE REGION. LOW PRESSURE WILL
MOVE SOUTHEAST ALONG THE FRONT TO THE CENTRAL GREAT LAKES BY MONDAY
NIGHT AND TO THE NEW ENGLAND COAST BY TUESDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
UPDATED THE FORECAST TO RAISE POPS ACROSS MAINLY
ASHTABULA/TRUMBULL/MAHONING COUNTIES WHERE PERSISTANT BAND OF
SHOWERS HAS SET UP. THESE SHOWERS HAVE DEVELOPED ON THE NORTHWEST
FLANK OF THE 700MB LOW IN AN AREA OF MID-LEVEL DEFORMATION ON THE
FRINGE OF THE DEEPER MOISTURE. LIFT IS BEING ENHANCED BY THE NEXT SHORTWAVE
DROPPING INTO THE TROUGH FROM THE NORTHWEST. THE DEEPER MOISTURE
WILL PULL EAST THIS EVENING AND MAY SEE THE SHOWERS SHIFT INTO
PENNSYLVANIA BEFORE DISSIPATING.
PREVIOUS DISCUSSION...CYCLONIC FLOW WILL CONTINUE ACROSS THE
EASTERN PORTIONS OF THE FORECAST AREA THIS EVENING AND CAUSE SOME
LIMITED MOISTURE TO ROTATE INTO THE REGION. MOST OF THE CLOUD
COVER OVER THIS AREA IS DIURNAL IN NATURE AND I SUSPECT THAT WE
SHOULD SEE A LOT OF IT DISSIPATE OVERNIGHT. DURING THE EVENING
HOURS...WE CANT RULE OUT A POSSIBLE SHOWER OR SPRINKLE IN THE
EAST. LATEST RADAR SHOWS A NICE BAND OF SHOWERS MOVING SOUTH
ACROSS THE EAST AT THIS TIME. THIS IS IN GOOD AGREEMENT WITH THE
LATEST HRRR MODEL. SO WILL MENTION SPRINKLES AND OR SHOWERS FOR
NOW DISSIPATING THIS EVENING.
THE WESTERN PORTIONS SHOULD SEE THE CLEARING PERSIST WITH SOME
POSSIBLE LAKE EFFECT CLOUDS GETTING IN THE WAY OF A CLEAR SKY
OVERNIGHT. EVERY WHERE ELSE IN BETWEEN...SKIES SHOULD BE PARTLY
CLOUDY WITH FAIR WEATHER.
COLD AIR ADVECTION EXPECTED OVERNIGHT WILL ALLOW TEMPERATURES TO DIP
WELL INTO THE LOWER 50S IN THE EAST AND MIDDLE 50S IN THE WEST. 850
MB TEMPERATURES HOVER AROUND 10 DEGREES C OVER THE FORECAST AREA.
WARMER TEMPERATURES IN THE WEST WILL RESULT IN THE SLIGHTLY HIGHER
SURFACE TEMPERATURES OVERNIGHT AS WELL.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY NIGHT/...
UPPER LEVEL TROUGH WILL FINALLY EXIT TO THE EAST OVERNIGHT ALLOWING
RIDGE TO BUILD IN FROM THE WEST BY SATURDAY EVENING. THE AMPLIFIED
RIDGE WILL DAMPEN OVER TIME AS IT MOVES EAST AND FLOW WILL BECOME
NEARLY ZONAL. THIS SHOULD HELP TEMPERATURES TO RETURN BACK TO MORE
NORMAL READINGS INTO THE WEEKEND.
FAIR WEATHER WILL BE THE RULE FOR FRIDAY AS THE HIGH PRESSURE
REMAINS THE DOMINANT WEATHER FEATURE DURING THIS PERIOD. THIS WILL
HOWEVER BE SHORT LIVED.
AS HIGH PRESSURE MOVES EAST OF THE AREA SATURDAY...A WARM FRONT WILL
LIFT NORTH ACROSS THE AREA AND BECOME NEARLY STATIONARY BY SATURDAY
NIGHT. THIS FEATURE WILL BRING WITH IT ASSOCIATED MOISTURE AND
SUPPORT ANOTHER CHANCE FOR SHOWERS AND THUNDERSTORMS SATURDAY
AFTERNOON AND SATURDAY NIGHT.
A SERIES OF UPPER LEVEL SHORTWAVE TROUGHS AND ASSOCIATED POSITIVE
VORTICITY ADVECTION AND VORTICITY MAXIMUMS WILL MOVE QUICKLY EAST
ACROSS THE FORECAST AREA. UNFORTUNATE PART IS IF THESE FEATURES SLOW
IN THEIR FORWARD MOTION COMPARED TO THEIR LATE NIGHT SATURDAY NIGHT
ARRIVAL AND SUNDAY MORNING...WE COULD SEE ANOTHER ROUND OF SEVERE
WEATHER THAT COULD AFFECT THE FORECAST AREA. WE OBVIOUSLY WILL BE
MONITORING THIS SITUATION AND SEE HOW IT DEVELOPS. BUT WILL KEEP THE
MENTION OUT OF THE HAZARDOUS WEATHER OUTLOOK DUE TO INSTABILITY NOT
LOOKING TOO FAVORABLE.
YET ANOTHER IMPULSE ALOFT WILL PUSH EAST ACROSS THE AREA SUNDAY
NIGHT KEEPING THE THREAT FOR SHOWERS AND THUNDERSTORMS GOING.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
THE MODELS CONTINUE TO STRUGGLE WITH THE TIMING OF ANOTHER WAVE THAT
MAY MOVE INTO THE CENTRAL GREAT LAKES ON MONDAY. SO AFTER A BRIEF
LULL IN THUNDERSTORM ACTIVITY LATE SUNDAY NIGHT INTO MONDAY MORNING
WE SHOULD SEE THUNDERSTORM CHANCES RETURN MONDAY AFTERNOON AND
EVENING. THERE MAY BE SOME LINGERING LIGHT SHOWERS OR THUNDERSTORMS
TUESDAY AS HIGH PRESSURE BEGINS TO BUILD INTO THE REGION FOR
WEDNESDAY.
MONDAY LOOKS AS IF IT WILL BE THE WARMEST DAY OF THE EXTENDED WITH
MOST LOCATIONS WITHING A FEW DEGREES OF 80. COOLER FOR TUESDAY AND
WEDNESDAY WITH HIGHS BACK INTO THE LOWER AND MIDDLE 70S.
&&
.AVIATION /22Z THURSDAY THROUGH TUESDAY/...
CEILINGS WILL CONTINUE TO LIFT AS A CLEARING LINE MOVES ACROSS
THE EASTERN HALF OF THE REGION. THERE WILL BE SOME CUMULUS THROUGH
THE AFTERNOON BUT BELIEVE IT WILL BE IN THE 2500 TO 4500 FOOT
RANGE. IT APPEARS THAT THE CLOUD COVER WILL RETURN
TONIGHT...ESPECIALLY THE EASTERN HALF OF THE AREA. MVFR SEEMS
LIKELY WITH PATCHES OF IFR CLOUD COVER AND FOG POSSIBLE AS WE
APPROACH SUNRISE. THIS SHOULD ALL ERODE BY EARLY FRIDAY AFTERNOON
WITH VFR CONDITIONS EXPECTED AT ALL LOCATIONS.
NORTHERLY WINDS WILL SLOWLY DECREASE THROUGH THE DAY.
.OUTLOOK...NON VFR POSSIBLE IN MORNING FOG SATURDAY AND SUNDAY
MORNINGS. NON VFR ALSO POSSIBLE SATURDAY NIGHT THROUGH MONDAY IN
THUNDERSTORMS.
&&
.MARINE...
WINDS REMAIN STRONG ENOUGH FOR WAVES TO REMAIN IN THE 3 TO 5 FOOT
RANGE INTO THE EVENING. WESTERN AREAS MAY DECREASE FASTER THAN
CURRENT THINKING BUT WILL KEEP THE SMALL CRAFT ADVISORY GOING FOR A
BIT LONGER. OTHERWISE HIGH PRESSURE WILL CONTINUE TO BUILD INTO THE
REGION FOR TONIGHT THROUGH SATURDAY. AS THE HIGH MOVES EASTERLY
WINDS WILL TURN TO THE SOUTHWEST. LOW PRESSURE WILL MOVE ACROSS THE
LAKE AT SOME POINT ON MONDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR
LEZ142>149.
&&
$$
SYNOPSIS...LOMBARDY
NEAR TERM...KEC/LOMBARDY
SHORT TERM...LOMBARDY
LONG TERM...MULLEN
AVIATION...MULLEN
MARINE...MULLEN
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
354 PM EDT THU JUN 13 2013
.SYNOPSIS...
HIGH PRESSURE WILL BUILD SOUTHEAST AND BE OVER THE AREA BY FRIDAY
NIGHT. THE HIGH WILL MOVE TO THE CAROLINA COAST BY SATURDAY NIGHT. A
WARM FRONT WILL LIFT NORTHEAST ACROSS THE AREA SATURDAY NIGHT AND
BECOME NEARLY STATIONARY NORTHEAST OF THE REGION. LOW PRESSURE WILL
MOVE SOUTHEAST ALONG THE FRONT TO THE CENTRAL GREAT LAKES BY MONDAY
NIGHT AND TO THE NEW ENGLAND COAST BY TUESDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
CYCLONIC FLOW WILL CONTINUE ACROSS THE EASTERN PORTIONS OF THE
FORECAST AREA THIS EVENING AND CAUSE SOME LIMITED MOISTURE TO ROTATE
INTO THE REGION. MOST OF THE CLOUD COVER OVER THIS AREA IS DIURNAL
IN NATURE AND I SUSPECT THAT WE SHOULD SEE A LOT OF IT DISSIPATE
OVERNIGHT. DURING THE EVENING HOURS...WE CANT RULE OUT A POSSIBLE
SHOWER OR SPRINKLE IN THE EAST. LATEST RADAR SHOWS A NICE BAND OF
SHOWERS MOVING SOUTH ACROSS THE EAST AT THIS TIME. THIS IS IN GOOD
AGREEMENT WITH THE LATEST HRRR MODEL. SO WILL MENTION SPRINKLES AND
OR SHOWERS FOR NOW DISSIPATING THIS EVENING.
THE WESTERN PORTIONS SHOULD SEE THE CLEARING PERSIST WITH SOME
POSSIBLE LAKE EFFECT CLOUDS GETTING IN THE WAY OF A CLEAR SKY
OVERNIGHT. EVERY WHERE ELSE IN BETWEEN...SKIES SHOULD BE PARTLY
CLOUDY WITH FAIR WEATHER.
COLD AIR ADVECTION EXPECTED OVERNIGHT WILL ALLOW TEMPERATURES TO DIP
WELL INTO THE LOWER 50S IN THE EAST AND MIDDLE 50S IN THE WEST. 850
MB TEMPERATURES HOVER AROUND 10 DEGREES C OVER THE FORECAST AREA.
WARMER TEMPERATURES IN THE WEST WILL RESULT IN THE SLIGHTLY HIGHER
SURFACE TEMPERATURES OVERNIGHT AS WELL.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY NIGHT/...
UPPER LEVEL TROUGH WILL FINALLY EXIT TO THE EAST OVERNIGHT ALLOWING
RIDGE TO BUILD IN FROM THE WEST BY SATURDAY EVENING. THE AMPLIFIED
RIDGE WILL DAMPEN OVER TIME AS IT MOVES EAST AND FLOW WILL BECOME
NEARLY ZONAL. THIS SHOULD HELP TEMPERATURES TO RETURN BACK TO MORE
NORMAL READINGS INTO THE WEEKEND.
FAIR WEATHER WILL BE THE RULE FOR FRIDAY AS THE HIGH PRESSURE
REMAINS THE DOMINANT WEATHER FEATURE DURING THIS PERIOD. THIS WILL
HOWEVER BE SHORT LIVED.
AS HIGH PRESSURE MOVES EAST OF THE AREA SATURDAY...A WARM FRONT WILL
LIFT NORTH ACROSS THE AREA AND BECOME NEARLY STATIONARY BY SATURDAY
NIGHT. THIS FEATURE WILL BRING WITH IT ASSOCIATED MOISTURE AND
SUPPORT ANOTHER CHANCE FOR SHOWERS AND THUNDERSTORMS SATURDAY
AFTERNOON AND SATURDAY NIGHT.
A SERIES OF UPPER LEVEL SHORTWAVE TROUGHS AND ASSOCIATED POSITIVE
VORTICITY ADVECTION AND VORTICITY MAXIMUMS WILL MOVE QUICKLY EAST
ACROSS THE FORECAST AREA. UNFORTUNATE PART IS IF THESE FEATURES SLOW
IN THEIR FORWARD MOTION COMPARED TO THEIR LATE NIGHT SATURDAY NIGHT
ARRIVAL AND SUNDAY MORNING...WE COULD SEE ANOTHER ROUND OF SEVERE
WEATHER THAT COULD AFFECT THE FORECAST AREA. WE OBVIOUSLY WILL BE
MONITORING THIS SITUATION AND SEE HOW IT DEVELOPS. BUT WILL KEEP THE
MENTION OUT OF THE HAZARDOUS WEATHER OUTLOOK DUE TO INSTABILITY NOT
LOOKING TOO FAVORABLE.
YET ANOTHER IMPULSE ALOFT WILL PUSH EAST ACROSS THE AREA SUNDAY
NIGHT KEEPING THE THREAT FOR SHOWERS AND THUNDERSTORMS GOING.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
THE MODELS CONTINUE TO STRUGGLE WITH THE TIMING OF ANOTHER WAVE THAT
MAY MOVE INTO THE CENTRAL GREAT LAKES ON MONDAY. SO AFTER A BRIEF
LULL IN THUNDERSTORM ACTIVITY LATE SUNDAY NIGHT INTO MONDAY MORNING
WE SHOULD SEE THUNDERSTORM CHANCES RETURN MONDAY AFTERNOON AND
EVENING. THERE MAY BE SOME LINGERING LIGHT SHOWERS OR THUNDERSTORMS
TUESDAY AS HIGH PRESSURE BEGINS TO BUILD INTO THE REGION FOR
WEDNESDAY.
MONDAY LOOKS AS IF IT WILL BE THE WARMEST DAY OF THE EXTENDED WITH
MOST LOCATIONS WITHING A FEW DEGREES OF 80. COOLER FOR TUESDAY AND
WEDNESDAY WITH HIGHS BACK INTO THE LOWER AND MIDDLE 70S.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
CEILINGS WILL CONTINUE TO LIFT AS A CLEARING LINE MOVES ACROSS
THE EASTERN HALF OF THE REGION. THERE WILL BE SOME CUMULUS THROUGH
THE AFTERNOON BUT BELIEVE IT WILL BE IN THE 2500 TO 4500 FOOT
RANGE. IT APPEARS THAT THE CLOUD COVER WILL RETURN
TONIGHT...ESPECIALLY THE EASTERN HALF OF THE AREA. MVFR SEEMS
LIKELY WITH PATCHES OF IFR CLOUD COVER AND FOG POSSIBLE AS WE
APPROACH SUNRISE. THIS SHOULD ALL ERODE BY EARLY FRIDAY AFTERNOON
WITH VFR CONDITIONS EXPECTED AT ALL LOCATIONS.
NORTHERLY WINDS WILL SLOWLY DECREASE THROUGH THE DAY.
.OUTLOOK...NON VFR POSSIBLE IN MORNING FOG SATURDAY AND SUNDAY
MORNINGS. NON VFR ALSO POSSIBLE SATURDAY NIGHT THROUGH MONDAY IN
THUNDERSTORMS.
&&
.MARINE...
WINDS REMAIN STRONG ENOUGH FOR WAVES TO REMAIN IN THE 3 TO 5 FOOT
RANGE INTO THE EVENING. WESTERN AREAS MAY DECREASE FASTER THAN
CURRENT THINKING BUT WILL KEEP THE SMALL CRAFT ADVISORY GOING FOR A
BIT LONGER. OTHERWISE HIGH PRESSURE WILL CONTINUE TO BUILD INTO THE
REGION FOR TONIGHT THROUGH SATURDAY. AS THE HIGH MOVES EASTERLY
WINDS WILL TURN TO THE SOUTHWEST. LOW PRESSURE WILL MOVE ACROSS THE
LAKE AT SOME POINT ON MONDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR
LEZ142>149.
&&
$$
SYNOPSIS...LOMBARDY
NEAR TERM...LOMBARDY
SHORT TERM...LOMBARDY
LONG TERM...MULLEN
AVIATION...MULLEN
MARINE...MULLEN
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
808 AM EDT THU JUN 13 2013
.SYNOPSIS...
LOW PRESSURE WILL CONTINUE TO MOVE AWAY FROM THE AREA TODAY. HIGH
PRESSURE WILL BUILD SOUTH ACROSS THE AREA BY SATURDAY MORNING AND
TO THE CAROLINA COAST BY SATURDAY NIGHT. ANOTHER FRONTAL SYSTEM
WILL AFFECT THE REGION FOR SUNDAY INTO MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CANCELLED SOME OF THE FLOOD WATCH BASED ON THE LOW RAINFALL
OVERNIGHT AND THE EXPECTED RAINFALL TODAY.
STILL THINKING THAT SOME OF THE SHOWERS OVER LAKE ERIE AND
ONTARIO WILL SWING INTO PARTS OF NORTH CENTRAL AND NORTHEAST OHIO
THIS AM. RAINFALL AMOUNTS SHOULD NOT BE REAL HIGH. THIS WILL BE
WATCHED.
KEPT THE FLOOD WATCH GOING BECAUSE RIVERS AND STREAMS ARE STILL
RISING...PROBABLY WILL BE ABLE TO CANCEL EARLY.
ON THE EDGE ABOUT THIS MORNING WHETHER SOME OF THE SHOWERS FROM
MICHIGAN WILL ROTATE INTO THE REGION...THE GFS AND HRRR KIND OF
HINTS AT THAT. WILL MONITOR THAT AND LOWER THE POPS AS NEEDED. THE
THREAT FOR THUNDER IS JUST ABOUT GONE. THE CLOUDS MAY TRY TO
DECREASE OVER NORTHWEST OHIO THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
SOME RESIDUAL SHOWERS MAY LINGER TONIGHT INTO FRIDAY OVER EXTREME
NORTHEAST OH AND NW PA...ON THE EDGE ABOUT THAT. HIGH PRESSURE
WILL BE BUILDING IN FROM THE NORTHWEST FRIDAY AFTERNOON AND THEN
THE HIGH WILL SHIFT EAST SATURDAY MORNING AS THE NEXT WEATHER
MAKER MOVES IN. SOME SHOWERS AND THUNDERSTORMS COULD SNEAK INTO
EXTREME NORTHWEST OHIO LATE IN THE AFTERNOON. KEPT THE THREAT
GOING THROUGH SUNDAY NIGHT. USED A BLEND OF GUIDANCE FOR THE
TEMPERATURES.
&&
.LONG TERM /MONDAY THROUGH WEDNESDAY/...
ANOTHER STRONGER FRONTAL SYSTEM WILL MOVE THROUGH MONDAY NIGHT AND
THEN HIGH PRESSURE WILL BUILD IN FOR WEDNESDAY. ENDED THE THREAT
OF SHOWERS AND THUNDERSTORMS TUESDAY NIGHT...THIS SHOULD WORK.
USED MAINLY HPC GUIDANCE FOR THE TEMPERATURE FORECAST.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
SEVERE WEATHER BEHIND US. IFR CONDITIONS IN WRAP AROUND SHOWERS
AFFECTING CLE/MFD AND POINTS EAST FOR SEVERAL HOURS THIS MORNING.
ALL GUIDANCE IS SHOWING CONDITIONS IMPROVING THIS AFTERNOON...AND
THIS IS IN LINE WITH UPSTREAM OBS. ACTUAL IFR AREA IS RATHER
THIN...ALTHOUGH LAKE ERIE AND NE OH/NW MAY PROLONG IT JUST A BIT
THROUGH THE MORNING. WINDS WILL GUST TODAY NNW AROUND 25 KNOTS.
HIGH PRESSURE BUILDS IN TONIGHT. MAY GET SOME STRATUS REDEVELOP
TOWARD 12Z FRIDAY.
.OUTLOOK...NON VFR CONDITIONS POSSIBLE TONIGHT AND ON AND OFF
BETWEEN SATURDAY NIGHT AND MONDAY IN SHOWERS AND THUNDERSTORMS.
&&
.MARINE...
UPDATED TO START THE SMALL CRAFT ADVISORY FOR AVON POINT WEST
IMMEDIATELY. FRONTAL BOUNDARY HUGGING THE LAKESHORE AND AS IT
SINKS SOUTH WIND SHIFT TO THE NORTH-NORTHWEST AND INCREASE
ENOUGH. SURFACE LOW PRESSURE ACROSS THE EASTERN LAKE ERIE TODAY
WILL CONTINUE TO MOVE EAST. LATER TONIGHT HIGH PRESSURE SHOULD BE
BUILDING IN WELL ENOUGH AND WINDS/WAVES WILL BE SUBSIDING. RIP
CURRENT RISK ELEVATES INTO THE HIGH CATEGORY FOR A TIME TODAY
ACROSS THE WESTERN THIRD. ELSEWHERE IT STICKS IN MODERATE
CATEGORY.
HIGH PRESSURE TONIGHT AND THROUGH THE DAY SATURDAY...SHIFTING EAST
SUNDAY. AS THE HIGH MOVES EAST...WINDS WILL TURN TO THE SOUTHWEST. LOW
PRESSURE SYSTEM AND ASSOCIATED COLD FRONT WILL BE CROSSING THE
WESTERN LAKES MONDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...FLOOD WATCH UNTIL NOON EDT TODAY FOR OHZ027>030-036-037-047.
FLOOD WATCH UNTIL 5 PM EDT THIS AFTERNOON FOR OHZ031-038.
PA...FLOOD WATCH UNTIL 5 PM EDT THIS AFTERNOON FOR PAZ001>003.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR
LEZ142>149.
&&
$$
SYNOPSIS...KIELTYKA
NEAR TERM...KIELTYKA
SHORT TERM...KIELTYKA
LONG TERM...KIELTYKA
AVIATION...OUDEMAN
MARINE...OUDEMAN
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
731 AM EDT THU JUN 13 2013
.SYNOPSIS...
LOW PRESSURE WILL CONTINUE TO MOVE AWAY FROM THE AREA TODAY. HIGH
PRESSURE WILL BUILD SOUTH ACROSS THE AREA BY SATURDAY MORNING AND
TO THE CAROLINA COAST BY SATURDAY NIGHT. ANOTHER FRONTAL SYSTEM
WILL AFFECT THE REGION FOR SUNDAY INTO MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CANCELLED SOME OF THE FLOOD WATCH BASED ON THE LOW RAINFALL
OVERNIGHT AND THE EXPECTED RAINFALL TODAY.
STILL THINKING THAT SOME OF THE SHOWERS OVER LAKE ERIE AND
ONTARIO WILL SWING INTO PARTS OF NORTH CENTRAL AND NORTHEAST OHIO
THIS AM. RAINFALL AMOUNTS SHOULD NOT BE REAL HIGH. THIS WILL BE
WATCHED.
KEPT THE FLOOD WATCH GOING BECAUSE RIVERS AND STREAMS ARE STILL
RISING...PROBABLY WILL BE ABLE TO CANCEL EARLY.
ON THE EDGE ABOUT THIS MORNING WHETHER SOME OF THE SHOWERS FROM
MICHIGAN WILL ROTATE INTO THE REGION...THE GFS AND HRRR KIND OF
HINTS AT THAT. WILL MONITOR THAT AND LOWER THE POPS AS NEEDED. THE
THREAT FOR THUNDER IS JUST ABOUT GONE. THE CLOUDS MAY TRY TO
DECREASE OVER NORTHWEST OHIO THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
SOME RESIDUAL SHOWERS MAY LINGER TONIGHT INTO FRIDAY OVER EXTREME
NORTHEAST OH AND NW PA...ON THE EDGE ABOUT THAT. HIGH PRESSURE
WILL BE BUILDING IN FROM THE NORTHWEST FRIDAY AFTERNOON AND THEN
THE HIGH WILL SHIFT EAST SATURDAY MORNING AS THE NEXT WEATHER
MAKER MOVES IN. SOME SHOWERS AND THUNDERSTORMS COULD SNEAK INTO
EXTREME NORTHWEST OHIO LATE IN THE AFTERNOON. KEPT THE THREAT
GOING THROUGH SUNDAY NIGHT. USED A BLEND OF GUIDANCE FOR THE
TEMPERATURES.
&&
.LONG TERM /MONDAY THROUGH WEDNESDAY/...
ANOTHER STRONGER FRONTAL SYSTEM WILL MOVE THROUGH MONDAY NIGHT AND
THEN HIGH PRESSURE WILL BUILD IN FOR WEDNESDAY. ENDED THE THREAT
OF SHOWERS AND THUNDERSTORMS TUESDAY NIGHT...THIS SHOULD WORK.
USED MAINLY HPC GUIDANCE FOR THE TEMPERATURE FORECAST.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
ORGANIZED CONVECTIVE SYSTEM MARCHING EAST ACROSS THE AREA EARLY
THIS MORNING. GUSTS CLOSE TO 50 KNOTS BEING REPORTED WITH THIS
LINE...WITH SLOW WEAKENING EXPECTED WITH TIME. SEVERAL HOUR PERIOD
OF MVFR RAIN FOLLOWS. IFR IN TS. AFTER RAIN MOVES OUT QUESTION
WILL BE IF WE GET ANY IFR AROUND DAWN. CONDITIONS NOT TOO LOW
UPSTREAM...SO WILL GO WITH MVFR CEILINGS...BUT THIS MAY
CHANGE...WILL MONITOR. WINDS FAIRLY VARIABLE TONIGHT. INITIALLY
WEST FOLLOWING CONVECTIVE LINE...THEN VARIABLE. FRONTAL ZONE
LINGERS ACROSS THE AREA. BY THURSDAY MORNING WILL ESTABLISH A
NORTH FLOW...GUSTS TO 25KTS OR SO. DRYING WILL TAKE PLACE THURSDAY
AFTERNOON...WITH CONDITIONS IMPROVING TO VFR.
.OUTLOOK...NON VFR CONDITIONS POSSIBLE THURSDAY NIGHT AND SATURDAY
NIGHT AND SUNDAY IN SHOWERS AND THUNDERSTORMS.
&&
.MARINE...
SURFACE LOW PRESSURE CENTER ACROSS THE WESTERN BASIN OF THE LAKE
TODAY WILL MOVE EAST-NORTHEAST ALONG THE LENGTH OF THE LAKE TODAY.
WINDS ON THE BACKSIDE OF THIS LOW ARE EXPECTED TO PICK UP TO 15 TO
25 KNOTS FOR A TIME TODAY...ALTHOUGH GUIDANCE GIVING SOME SLIGHT
DIFFERENCES ON THAT. STILL WENT AHEAD WITH THE SMALL CRAFT
ADVISORY THROUGH THIS EVENING. WOULD THINK THAT WE COULD EASILY
AVERAGE 4 FOOTERS. LATER TONIGHT HIGH PRESSURE SHOULD BE BUILDING
IN WELL ENOUGH AND WINDS/WAVES WILL BE SUBSIDING. RIP CURRENT RISK
ELEVATES INTO THE HIGH CATEGORY FOR A TIME TODAY ACROSS THE
WESTERN THIRD. ELSEWHERE IT STICKS IN MODERATE CATEGORY.
HIGH PRESSURE TONIGHT AND THROUGH THE DAY SATURDAY...SHIFTING EAST
SUNDAY. AS THE HIGH MOVES EAST...WINDS WILL TURN TO THE SOUTHWEST. LOW
PRESSURE SYSTEM AND ASSOCIATED COLD FRONT WILL BE CROSSING THE
WESTERN LAKES MONDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...FLOOD WATCH UNTIL NOON EDT TODAY FOR OHZ027>030-036-037-047.
FLOOD WATCH UNTIL 5 PM EDT THIS AFTERNOON FOR OHZ031-038.
PA...FLOOD WATCH UNTIL 5 PM EDT THIS AFTERNOON FOR PAZ001>003.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR
LEZ146>149.
SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR
LEZ142>145.
&&
$$
SYNOPSIS...KIELTYKA
NEAR TERM...KIELTYKA
SHORT TERM...KIELTYKA
LONG TERM...KIELTYKA
AVIATION...OUDEMAN
MARINE...OUDEMAN
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
512 AM EDT THU JUN 13 2013
.SYNOPSIS...
LOW PRESSURE OVER OHIO WILL MOVE INTO PENNSYLVANIA THIS MORNING. HIGH
PRESSURE WILL BUILD SOUTH ACROSS THE AREA BY SATURDAY MORNING AND
TO THE CAROLINA COAST BY SATURDAY NIGHT. ANOTHER FRONTAL SYSTEM
WILL AFFECT THE REGION FOR SUNDAY INTO MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CANCELLED SEVERE THUNDERSTORM WATCH. STILL THINKING THAT SOME OF
THE SHOWERS OVER LAKE ERIE AND ONTARIO WILL SWING INTO PARTS OF
NORTH CENTRAL AND NORTHEAST OHIO THIS AM. RAINFALL AMOUNTS SHOULD
NOT BE REAL HIGH. THIS WILL BE WATCHED.
KEPT THE FLOOD WATCH GOING BECAUSE RIVERS AND STREAMS ARE STILL
RISING...PROBABLY WILL BE ABLE TO CANCEL EARLY.
ON THE EDGE ABOUT THIS MORNING WHETHER SOME OF THE SHOWERS FROM
MICHIGAN WILL ROTATE INTO THE REGION...THE GFS AND HRRR KIND OF
HINTS AT THAT. WILL MONITOR THAT AND LOWER THE POPS AS NEEDED. THE
THREAT FOR THUNDER IS JUST ABOUT GONE. THE CLOUDS MAY TRY TO
DECREASE OVER NORTHWEST OHIO THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
SOME RESIDUAL SHOWERS MAY LINGER TONIGHT INTO FRIDAY OVER EXTREME
NORTHEAST OH AND NW PA...ON THE EDGE ABOUT THAT. HIGH PRESSURE
WILL BE BUILDING IN FROM THE NORTHWEST FRIDAY AFTERNOON AND THEN
THE HIGH WILL SHIFT EAST SATURDAY MORNING AS THE NEXT WEATHER
MAKER MOVES IN. SOME SHOWERS AND THUNDERSTORMS COULD SNEAK INTO
EXTREME NORTHWEST OHIO LATE IN THE AFTERNOON. KEPT THE THREAT
GOING THROUGH SUNDAY NIGHT. USED A BLEND OF GUIDANCE FOR THE
TEMPERATURES.
&&
.LONG TERM /MONDAY THROUGH WEDNESDAY/...
ANOTHER STRONGER FRONTAL SYSTEM WILL MOVE THROUGH MONDAY NIGHT AND
THEN HIGH PRESSURE WILL BUILD IN FOR WEDNESDAY. ENDED THE THREAT
OF SHOWERS AND THUNDERSTORMS TUESDAY NIGHT...THIS SHOULD WORK.
USED MAINLY HPC GUIDANCE FOR THE TEMPERATURE FORECAST.
&&
.AVIATION /09Z THURSDAY THROUGH MONDAY/...
ORGANIZED CONVECTIVE SYSTEM MARCHING EAST ACROSS THE AREA EARLY
THIS MORNING. GUSTS CLOSE TO 50 KNOTS BEING REPORTED WITH THIS
LINE...WITH SLOW WEAKENING EXPECTED WITH TIME. SEVERAL HOUR PERIOD
OF MVFR RAIN FOLLOWS. IFR IN TS. AFTER RAIN MOVES OUT QUESTION
WILL BE IF WE GET ANY IFR AROUND DAWN. CONDITIONS NOT TOO LOW
UPSTREAM...SO WILL GO WITH MVFR CEILINGS...BUT THIS MAY
CHANGE...WILL MONITOR. WINDS FAIRLY VARIABLE TONIGHT. INITIALLY
WEST FOLLOWING CONVECTIVE LINE...THEN VARIABLE. FRONTAL ZONE
LINGERS ACROSS THE AREA. BY THURSDAY MORNING WILL ESTABLISH A
NORTH FLOW...GUSTS TO 25KTS OR SO. DRYING WILL TAKE PLACE THURSDAY
AFTERNOON...WITH CONDITIONS IMPROVING TO VFR.
.OUTLOOK...NON VFR CONDITIONS POSSIBLE THURSDAY NIGHT AND SATURDAY
NIGHT AND SUNDAY IN SHOWERS AND THUNDERSTORMS.
&&
.MARINE...
SURFACE LOW PRESSURE CENTER ACROSS THE WESTERN BAISN OF THE LAKE
TODAY WILL MOVE EAST-NORTHEAST ALONG THE LENGTH OF THE LAKE TODAY.
WINDS ON THE BACKSIDE OF THIS LOW ARE EXPECTED TO PICK UP TO 15 TO
25 KNOTS FOR A TIME TODAY...ALTHOUGH GUIDANCE GIVING SOME SLIGHT
DIFFERENCES ON THAT. STILL WENT AHEAD WITH THE SMALL CRAFT
ADVISORY THROUGH THIS EVENING. WOULD THINK THAT WE COULD EASILY
AVERAGE 4 FOOTERS. LATER TONIGHT HIGH PRESSURE SHOULD BE BUILDING
IN WELL ENOUGH AND WINDS/WAVES WILL BE SUBSIDING. RIP CURRENT RISK
ELEVATES INTO THE HIGH CATEGORY FOR A TIME TODAY ACROSS THE
WESTERN THIRD. ELSEWHERE IT STICKS IN MODERATE CATEGORY.
HIGH PRESSURE TONIGHT AND THROUGH THE DAY SATURDAY...SHIFTING EAST
SUNDAY. AS THE HIGH MOVES EAST...WINDS WILL TURN TO THE SOUTHWEST. LOW
PRESSURE SYSTEM AND ASSOCIATED COLD FRONT WILL BE CROSSING THE
WESTERN LAKES MONDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...FLOOD WATCH UNTIL 5 PM EDT THIS AFTERNOON FOR OHZ011>014-
020>023-031>033-038-089.
FLOOD WATCH UNTIL NOON EDT TODAY FOR OHZ003-006>010-017>019-
027>030-036-037-047.
PA...FLOOD WATCH UNTIL 5 PM EDT THIS AFTERNOON FOR PAZ001>003.
MARINE...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 10 PM EDT THIS
EVENING FOR LEZ146>149.
SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR
LEZ142>145.
&&
$$
SYNOPSIS...KIELTYKA
NEAR TERM...KIELTYKA
SHORT TERM...KIELTYKA
LONG TERM...KIELTYKA
AVIATION...OUDEMAN
MARINE...OUDEMAN
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
442 AM EDT THU JUN 13 2013
.SYNOPSIS...
LOW PRESSURE OVER OHIO WILL MOVE INTO PENNSYLVANIA THIS MORNING. HIGH
PRESSURE WILL BUILD SOUTH ACROSS THE AREA BY SATURDAY MORNING AND
TO THE CAROLINA COAST BY SATURDAY NIGHT. ANOTHER FRONTAL SYSTEM
WILL AFFECT THE REGION FOR SUNDAY INTO MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SHOULD BE ABLE TO CANCEL THE SEVERE THUNDERSTORM WATCH FOR NW PA
BY 5 AM.
KEPT THE FLOOD WATCH GOING BECAUSE RIVERS AND STREAMS ARE STILL
RISING...PROBABLY WILL BE ABLE TO CANCEL EARLY.
ON THE EDGE ABOUT THIS MORNING WHETHER SOME OF THE SHOWERS FROM
MICHIGAN WILL ROTATE INTO THE REGION...THE GFS AND HRRR KIND OF
HINTS AT THAT. WILL MONITOR THAT AND LOWER THE POPS AS NEEDED. THE
THREAT FOR THUNDER IS JUST ABOUT GONE. THE CLOUDS MAY TRY TO
DECREASE OVER NORTHWEST OHIO THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
SOME RESIDUAL SHOWERS MAY LINGER TONIGHT INTO FRIDAY OVER EXTREME
NORTHEAST OH AND NW PA...ON THE EDGE ABOUT THAT. HIGH PRESSURE
WILL BE BUILDING IN FROM THE NORTHWEST FRIDAY AFTERNOON AND THEN
THE HIGH WILL SHIFT EAST SATURDAY MORNING AS THE NEXT WEATHER
MAKER MOVES IN. SOME SHOWERS AND THUNDERSTORMS COULD SNEAK INTO
EXTREME NORTHWEST OHIO LATE IN THE AFTERNOON. KEPT THE THREAT
GOING THROUGH SUNDAY NIGHT. USED A BLEND OF GUIDANCE FOR THE
TEMPERATURES.
&&
.LONG TERM /MONDAY THROUGH WEDNESDAY/...
ANOTHER STRONGER FRONTAL SYSTEM WILL MOVE THROUGH MONDAY NIGHT AND
THEN HIGH PRESSURE WILL BUILD IN FOR WEDNESDAY. ENDED THE THREAT
OF SHOWERS AND THUNDERSTORMS TUESDAY NIGHT...THIS SHOULD WORK.
USED MAINLY HPC GUIDANCE FOR THE TEMPERATURE FORECAST.
&&
.AVIATION /09Z THURSDAY THROUGH MONDAY/...
ORGANIZED CONVECTIVE SYSTEM MARCHING EAST ACROSS THE AREA EARLY
THIS MORNING. GUSTS CLOSE TO 50 KNOTS BEING REPORTED WITH THIS
LINE...WITH SLOW WEAKENING EXPECTED WITH TIME. SEVERAL HOUR PERIOD
OF MVFR RAIN FOLLOWS. IFR IN TS. AFTER RAIN MOVES OUT QUESTION
WILL BE IF WE GET ANY IFR AROUND DAWN. CONDITIONS NOT TOO LOW
UPSTREAM...SO WILL GO WITH MVFR CEILINGS...BUT THIS MAY
CHANGE...WILL MONITOR. WINDS FAIRLY VARIABLE TONIGHT. INITIALLY
WEST FOLLOWING CONVECTIVE LINE...THEN VARIABLE. FRONTAL ZONE
LINGERS ACROSS THE AREA. BY THURSDAY MORNING WILL ESTABLISH A
NORTH FLOW...GUSTS TO 25KTS OR SO. DRYING WILL TAKE PLACE THURSDAY
AFTERNOON...WITH CONDITIONS IMPROVING TO VFR.
.OUTLOOK...NON VFR CONDITIONS POSSIBLE THURSDAY NIGHT AND SATURDAY
NIGHT AND SUNDAY IN SHOWERS AND THUNDERSTORMS.
&&
.MARINE...
SURFACE LOW PRESSURE CENTER ACROSS THE WESTERN BAISN OF THE LAKE
TODAY WILL MOVE EAST-NORTHEAST ALONG THE LENGTH OF THE LAKE TODAY.
WINDS ON THE BACKSIDE OF THIS LOW ARE EXPECTED TO PICK UP TO 15 TO
25 KNOTS FOR A TIME TODAY...ALTHOUGH GUIDANCE GIVING SOME SLIGHT
DIFFERENCES ON THAT. STILL WENT AHEAD WITH THE SMALL CRAFT
ADVISORY THROUGH THIS EVENING. WOULD THINK THAT WE COULD EASILY
AVERAGE 4 FOOTERS. LATER TONIGHT HIGH PRESSURE SHOULD BE BUILDING
IN WELL ENOUGH AND WINDS/WAVES WILL BE SUBSIDING. RIP CURRENT RISK
ELEVATES INTO THE HIGH CATEGORY FOR A TIME TODAY ACROSS THE
WESTERN THIRD. ELSEWHERE IT STICKS IN MODERATE CATEGORY.
HIGH PRESSURE TONIGHT AND THROUGH THE DAY SATURDAY...SHIFTING EAST
SUNDAY. AS THE HIGH MOVES EAST...WINDS WILL TURN TO THE SOUTHWEST. LOW
PRESSURE SYSTEM AND ASSOCIATED COLD FRONT WILL BE CROSSING THE
WESTERN LAKES MONDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...FLOOD WATCH THROUGH THIS AFTERNOON FOR OHZ011>014-020>023-
031>033-038-089.
FLOOD WATCH UNTIL NOON EDT TODAY FOR OHZ003-006>010-017>019-
027>030-036-037-047.
PA...FLOOD WATCH THROUGH THIS AFTERNOON FOR PAZ001>003.
MARINE...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 10 PM EDT THIS
EVENING FOR LEZ146>149.
SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR
LEZ142>145.
&&
$$
SYNOPSIS...KIELTYKA
NEAR TERM...KIELTYKA
SHORT TERM...KIELTYKA
LONG TERM...KIELTYKA
AVIATION...OUDEMAN
MARINE...OUDEMAN
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
423 AM EDT THU JUN 13 2013
.SYNOPSIS...
LOW PRESSURE OVER OHIO WILL MOVE INTO PENNSYLVANIA THIS MORNING. HIGH
PRESSURE WILL BUILD SOUTH ACROSS THE AREA BY SATURDAY MORNING AND
TO THE CAROLINA COAST BY SATURDAY NIGHT. ANOTHER FRONTAL SYSTEM
WILL AFFECT THE REGION FOR SUNDAY INTO MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SHOULD BE ABLE TO CANCEL THE SEVERE THUNDERSTORM WATCH FOR NW PA
BY 5 AM.
KEPT THE FLOOD WATCH GOING BECAUSE RIVERS AND STREAMS ARE STILL
RISING...PROBABLY WILL BE ABLE TO CANCEL EARLY.
ON THE EDGE ABOUT THIS MORNING WHETHER SOME OF THE SHOWERS FROM
MICHIGAN WILL ROTATE INTO THE REGION...THE GFS AND HRRR KIND OF
HINTS AT THAT. WILL MONITOR THAT AND LOWER THE POPS AS NEEDED. THE
THREAT FOR THUNDER IS JUST ABOUT GONE. THE CLOUDS MAY TRY TO
DECREASE OVER NORTHWEST OHIO THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
SOME RESIDUAL SHOWERS MAY LINGER TONIGHT INTO FRIDAY OVER EXTREME
NORTHEAST OH AND NW PA...ON THE EDGE ABOUT THAT. HIGH PRESSURE
WILL BE BUILDING IN FROM THE NORTHWEST FRIDAY AFTERNOON AND THEN
THE HIGH WILL SHIFT EAST SATURDAY MORNING AS THE NEXT WEATHER
MAKER MOVES IN. SOME SHOWERS AND THUNDERSTORMS COULD SNEAK INTO
EXTREME NORTHWEST OHIO LATE IN THE AFTERNOON. KEPT THE THREAT
GOING THROUGH SUNDAY NIGHT. USED A BLEND OF GUIDANCE FOR THE
TEMPERATURES.
&&
.LONG TERM /MONDAY THROUGH WEDNESDAY/...
ANOTHER STRONGER FRONTAL SYSTEM WILL MOVE THROUGH MONDAY NIGHT AND
THEN HIGH PRESSURE WILL BUILD IN FOR WEDNESDAY. ENDED THE THREAT
OF SHOWERS AND THUNDERSTORMS TUESDAY NIGHT...THIS SHOULD WORK.
USED MAINLY HPC GUIDANCE FOR THE TEMPERATURE FORECAST.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
ORGANIZED CONVECTIVE SYSTEM MARCHING EAST ACROSS THE AREA EARLY
THIS MORNING. GUSTS CLOSE TO 50 KNOTS BEING REPORTED WITH THIS
LINE...WITH SLOW WEAKENING EXPECTED WITH TIME. SEVERAL HOUR PERIOD
OF MVFR RAIN FOLLOWS. IFR IN TS. AFTER RAIN MOVES OUT QUESTION
WILL BE IF WE GET ANY IFR AROUND DAWN. CONDITIONS NOT TOO LOW
UPSTREAM...SO WILL GO WITH MVFR CEILINGS...BUT THIS MAY
CHANGE...WILL MONITOR. WINDS FAIRLY VARIABLE TONIGHT. INITIALLY
WEST FOLLOWING CONVECTIVE LINE...THEN VARIABLE. FRONTAL ZONE
LINGERS ACROSS THE AREA. BY THURSDAY MORNING WILL ESTABLISH A
NORTH FLOW...GUSTS TO 25KTS OR SO. DRYING WILL TAKE PLACE THURSDAY
AFTERNOON...WITH CONDITIONS IMPROVING TO VFR.
.OUTLOOK...NON VFR CONDITIONS POSSIBLE THURSDAY NIGHT AND SATURDAY
NIGHT AND SUNDAY IN SHOWERS AND THUNDERSTORMS.
&&
.MARINE...
SCATTERED SHOWERS CONTINUE OVER LAKE ERIE THIS AFTERNOON WITH WINDS
VARYING FROM A NORTHEAST TO SOUTHEAST DIRECTION. LATER TONIGHT...A
LOW PRESSURE DISTURBANCE WILL MOVE EAST ALONG A QUASISTATIONARY
BOUNDARY LYING ACROSS CENTRAL OHIO. SHOWERS AND THUNDERSTORMS WILL
ACCOMPANY THE DISTURBANCE. SOME OF THE THUNDERSTORMS MAY BECOME
SEVERE...WARRANTING A SPECIAL MARINE WARNING.
SHOWERS ARE EXPECTED TO CONTINUE INTO THURSDAY AHEAD OF A COLD
FRONT. MOST OF THE SHOWERS WILL OCCUR OVERNIGHT INTO THURSDAY
MORNING. WINDS WILL INCREASE IN SPEED WITH THE PASSAGE OF THE COLD
FRONT THURSDAY NIGHT. MODELS ARE STILL A BIT UNCERTAIN WITH HOW
STRONG WINDS WILL GET...WHICH WILL AFFECT WAVE HEIGHTS. FOR NOW IT
DOES NOT APPEAR THAT A SMALL CRAFT ADVISORY WILL BE NECESSARY...BUT
THE NEXT FORECAST SHIFT WILL CONTINUE TO MONITOR THE SITUATION.
HIGH PRESSURE WILL BUILD OVER THE LAKE FRIDAY NIGHT AND MOVE EAST
LATE SATURDAY NIGHT. AS THE HIGH MOVES EAST...WINDS WILL TURN TO THE
SOUTHWEST AND PICK UP SPEED. A LOW PRESSURE SYSTEM AND ASSOCIATED
COLD FRONT WILL APPROACH THE AREA ON MONDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...FLOOD WATCH THROUGH THIS AFTERNOON FOR OHZ011>014-020>023-
031>033-038-089.
FLOOD WATCH UNTIL NOON EDT TODAY FOR OHZ003-006>010-017>019-
027>030-036-037-047.
PA...FLOOD WATCH THROUGH THIS AFTERNOON FOR PAZ001>003.
MARINE...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 10 PM EDT THIS
EVENING FOR LEZ146>149.
SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR
LEZ142>145.
&&
$$
SYNOPSIS...KIELTYKA
NEAR TERM...KIELTYKA
SHORT TERM...KIELTYKA
LONG TERM...KIELTYKA
AVIATION...OUDEMAN
MARINE...OUDEMAN
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
205 AM EDT THU JUN 13 2013
.SYNOPSIS...
A WARM FRONT WILL BECOME NEARLY STATIONARY ACROSS NORTHERN OHIO AND
NORTHERN PENNSYLVANIA THROUGH THURSDAY MORNING AS LOW PRESSURE MOVES
EAST ALONG THE FRONT. HIGH PRESSURE WILL BUILD SOUTH ACROSS THE AREA
BY SATURDAY MORNING AND TO THE CAROLINA COAST BY SATURDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
UPDATED FOR WATCH. THE MAIN THREAT IS MOVING INTO NW
OHIO...HOWEVER...SOME CONVECTION AHEAD OF THIS LINE MAY BE SEVERE
OR TORNADIC.
PREVIOUS...
UPDATED FOR SEVERE WATCH. CONVECTION NOW DEVELOPING IN IOWA AND
ILLINOIS. THIS IS EXPECTED TO DEVELOP INTO A SQUALL LINE THAT WILL
MOVE INTO WESTERN OHIO LATE THIS EVENING TO AROUND MIDNIGHT. IF
CONVECTION DEVELOPS AHEAD OF THE LINE...IT TOO COULD BECOME
SEVERE. THIS IS A PDS WATCH WITH THE EXPECTATION OF THUNDERSTORMS
CONTAINING DAMAGING WINDS IN EXCESS OF 65 KTS. THERMODYNAMICS
BACKS THIS UP WITH DRY AIR ALOFT CONTRIBUTING TO DOWNDRAFT CAPES
OVER 1000K/KG. SHEAR PROFILES ALSO SUGGEST FORWARD PROPAGATION
ADDING TO WIND POTENTIAL. ROTATING SUPERCELLS ALSO SUPPORTED SO
TORNADOES ARE ALSO POSSIBLE.
PREVIOUS...THE WAITING GAME BEGINS. SO FAR ATMOSPHERE APPEARS TO
BE WELL CAPPED AND IS SUPPRESSING CONVECTION FROM DEVELOPING
UPSTREAM. THE OTHER ISSUE AT HAND IS THE EXTENSIVE DEBRIS CLOUDS
HANGING AROUND. WE NEVER CLEARED OUT OR HAD ANY BREAKS IN THE
OVERCAST AS EXPECTED AND THIS IS ALSO LIMITING ANY DEVELOPMENT
OVER THE REGION.
COORDINATED WITH COFORECASTER...IT APPEARS AN AREA OF CONVERGENCE
HAS SET UP BACK OVER EASTERN IOWA AND NORTHWEST ILLINOIS AT THIS
TIME AND THIS COULD VERY WELL BE THE LOCATION THE THUNDERSTORMS
DEVELOP. LATEST HRRR MODEL SHOWS CONVECTION FIRING OVER THIS AREA AS
WELL AND HAS BEEN PRETTY CONSISTENT FROM RUN TO RUN TODAY. THERE IS
THE POSSIBILITY THAT ACTIVITY COULD DEVELOP AHEAD OF THE MAIN LINE
AS INDIVIDUAL CELLS OVERNIGHT.
LATEST SURFACE ANALYSIS SHOWS DEWPOINT TEMPERATURES RISING INTO THE
LOWER 70S INTO THE SOUTHWEST PORTION OF THE FORECAST AREA AT THIS
TIME. WE SHOULD CONTINUE TO SEE A SURGE OF THE HIGHER DEWPOINT AIR
INTO THE FORECAST AREA AS THE EVENING PROGRESSES. THIS WILL HELP TO
INCREASE THE MOISTURE ACROSS THE REGION PRIMING THE ATMOSPHERE FOR
THE POTENTIAL FOR HEAVY RAIN THAT WE HAVE BEEN EXPECTING.
THE SURGE OF STRONG STORMS WILL ENTER THE AREA AND COULD POSSIBLY
EVOLVE INTO AN OVERRUNNING SITUATION ALONG THE STATIONARY FRONT LATE
TONIGHT. THE SEVERE THREAT WILL TRANSITION INTO A POTENTIAL FLOODING
THREAT WITH LOCALLY HEAVY RAIN FROM THE THUNDERSTORMS. THUNDERSTORMS
WILL BE EFFICIENT RAIN PRODUCERS AND AREAS COULD SEE SUBSTANTIAL
PONDING OF WATER OVERNIGHT ALONG WITH THE RAPID RISES OF RIVERS AND
STREAMS. SEE HYDRO SECTION BELOW.
TROPICAL AIR MASS OVER THE REGION WILL BE ACROSS THE SOUTHERN HALF
OF THE FORECAST AREA. NORTHERN HALF OF THE AREA WILL REMAIN NORTH OF
THE STATIONARY FRONT MOST OF THE NIGHT. AS THE LOW PRESSURE SYSTEM
MOVES EAST...IT WILL PUSH THE FRONT NORTH TO THE LAKE SHORE AS A
WARM FRONT. TEMPERATURES OVERNIGHT IN THE LOWER 70S SOUTH AND UPPER
60S IN THE NORTH.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY NIGHT/...
LOW PRESSURE IS PROGGED TO PULL OUT TO THE EAST THURSDAY MORNING AS
UPPER LEVEL AMPLIFIED RIDGE BUILDS EAST FORCING UPPER LEVEL TROUGH
OFF THE COAST. AS SURFACE LOW MOVES EAST...ASSOCIATED MOISTURE AND
SUBSEQUENT PRECIPITATION WILL EXIT TO THE EAST AS WELL. HIGH
PRESSURE AT THE SURFACE PUSHES SOUTHEAST ACROSS THE AREA FORCING
DRIER AIR INTO THE REGION FOR THURSDAY NIGHT INTO FRIDAY.
THE HIGH WILL MOVE SOUTHEAST TO THE CAROLINA COAST BY SATURDAY NIGHT
AND THIS WILL SET UP ANOTHER RETURN SOUTHERLY FLOW TO THE FORECAST
AREA. A FAIRLY FAST MOVING SHORTWAVE TROUGH AND ASSOCIATED MOISTURE
WILL BEGIN TO MOVE EAST INTO THE FORECAST AREA SATURDAY INTO
SATURDAY NIGHT AND COULD BRING ANOTHER ROUND OF SHOWERS TO THE
FORECAST AREA.
COLD AIR ADVECTION ASSOCIATED WITH THE HIGH PRESSURE WILL OCCUR ON
THURSDAY BUT WILL BE SHORT LIVED AS HIGH MOVES TO THE SOUTHEAST. AS
MENTIONED EARLIER...RETURN SOUTHERLY FLOW WILL BRING TEMPERATURES
BACK UP INTO THE MIDDLE 70S EAST AND UPPER 70S TO LOWER 80S WEST BY
SATURDAY. LOWS DIPPING BACK TO THE 50S THURSDAY AND FRIDAY NIGHTS.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
A RIPPLE OF LOW PRESSURE WILL BE MOVING INTO THE REGION ON SUNDAY
WITH SCATTERED THUNDERSTORMS POSSIBLE...ESPECIALLY SUNDAY AFTERNOON.
THE MODELS ARE THEN STRUGGLING WITH THE TIMING OF ANOTHER WAVE THAT
MAY MOVE INTO THE CENTRAL GREAT LAKES ON MONDAY. SO AFTER A BRIEF
LULL IN THUNDERSTORM ACTIVITY LATE SUNDAY NIGHT INTO MONDAY MORNING
WE SHOULD SEE THUNDERSTORM CHANCES RETURN MONDAY AFTERNOON AND
EVENING. THERE MAY BE SOME LINGERING LIGHT SHOWERS OR THUNDERSTORMS
TUESDAY AS HIGH PRESSURE BEGINS TO BUILD INTO THE REGION LATE.
TEMPERATURES THROUGH THE EXTENDED WILL BE WITHIN A FEW DEGREES OF
SEASONAL AVERAGES.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
ORGANIZED CONVECTIVE SYSTEM MARCHING EAST ACROSS THE AREA EARLY
THIS MORNING. GUSTS CLOSE TO 50 KNOTS BEING REPORTED WITH THIS
LINE...WITH SLOW WEAKENING EXPECTED WITH TIME. SEVERAL HOUR PERIOD
OF MVFR RAIN FOLLOWS. IFR IN TS. AFTER RAIN MOVES OUT QUESTION
WILL BE IF WE GET ANY IFR AROUND DAWN. CONDITIONS NOT TOO LOW
UPSTREAM...SO WILL GO WITH MVFR CEILINGS...BUT THIS MAY
CHANGE...WILL MONITOR. WINDS FAIRLY VARIABLE TONIGHT. INITIALLY
WEST FOLLOWING CONVECTIVE LINE...THEN VARIABLE. FRONTAL ZONE
LINGERS ACROSS THE AREA. BY THURSDAY MORNING WILL ESTABLISH A
NORTH FLOW...GUSTS TO 25KTS OR SO. DRYING WILL TAKE PLACE THURSDAY
AFTERNOON...WITH CONDITIONS IMPROVING TO VFR.
.OUTLOOK...NON VFR CONDITIONS POSSIBLE THURSDAY NIGHT AND SATURDAY
NIGHT AND SUNDAY IN SHOWERS AND THUNDERSTORMS.
&&
.MARINE...
SCATTERED SHOWERS CONTINUE OVER LAKE ERIE THIS AFTERNOON WITH WINDS
VARYING FROM A NORTHEAST TO SOUTHEAST DIRECTION. LATER TONIGHT...A
LOW PRESSURE SYSTEM WILL MOVE EAST ALONG A QUASISTATIONARY BOUNDARY
LYING ACROSS CENTRAL OHIO. SHOWERS AND THUNDERSTORMS WILL
ACCOMPANY THE DISTURBANCE. SOME OF THE THUNDERSTORMS MAY BECOME
SEVERE...WARRANTING A SPECIAL MARINE WARNING.
SHOWERS ARE EXPECTED TO CONTINUE INTO THURSDAY AHEAD OF A COLD
FRONT. MOST OF THE SHOWERS WILL OCCUR OVERNIGHT INTO THURSDAY
MORNING. WINDS WILL INCREASE IN SPEED WITH THE PASSAGE OF THE COLD
FRONT THURSDAY NIGHT. MODELS ARE STILL A BIT UNCERTAIN WITH HOW
STRONG WINDS WILL GET...WHICH WILL AFFECT WAVE HEIGHTS. FOR NOW IT
DOES NOT APPEAR THAT A SMALL CRAFT ADVISORY WILL BE NECESSARY...BUT
THE NEXT FORECAST SHIFT WILL CONTINUE TO MONITOR THE SITUATION.
HIGH PRESSURE WILL BUILD OVER THE LAKE FRIDAY NIGHT AND MOVE EAST
LATE SATURDAY NIGHT. AS THE HIGH MOVES EAST...WINDS WILL TURN TO THE
SOUTHWEST AND PICK UP SPEED. A LOW PRESSURE SYSTEM AND ASSOCIATED
COLD FRONT WILL APPROACH THE AREA ON MONDAY.
&&
.HYDROLOGY...
A FLOOD WATCH IS IN EFFECT FOR THE ENTIRE AREA FROM THE HEAVY
RAINFALL EXPECTED OVERNIGHT AND EARLY THURSDAY. MOISTURE ADVECTION
WILL INCREASE OVER THE AREA THIS AFTERNOON AND NOTABLY OVERNIGHT AS
AN AREA OF LOW PRESSURE MOVES INTO THE REGION FROM THE WEST. THERE
IS SOME INDICATION THAT PRECIPITABLE WATER VALUES COULD REACH 2.0"
WHICH IS ANOMALOUSLY HIGH FOR THIS TIME OF YEAR. THE SHOWERS WILL BE
EFFICIENT RAIN MAKERS AND COULD DROP A QUICK INCH TO AN AREA. THE
THREAT OF TRAINING STORMS IS HIGH SUGGESTING THE THREAT OF A QUICK 2
TO 3 INCHES OF RAIN IS POSSIBLE. RAINFALL RATES THIS HIGH COULD
PRODUCE FLASH FLOODING. THE HEAVIEST RAIN WILL FALL BETWEEN 10 PM
TONIGHT AND 8 AM THURSDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...FLOOD WATCH THROUGH THIS AFTERNOON FOR OHZ011>014-020>023-
031>033-038-089.
FLOOD WATCH UNTIL 1 PM EDT THIS AFTERNOON FOR OHZ003-006>010-
017>019-027>030-036-037-047.
PA...FLOOD WATCH THROUGH THIS AFTERNOON FOR PAZ001>003.
MARINE...NONE.
&&
$$
SYNOPSIS...LOMBARDY
NEAR TERM...KIELTYKA/TK/LOMBARDY
SHORT TERM...LOMBARDY
LONG TERM...MULLEN
AVIATION...OUDEMAN
MARINE...MULLEN/YEAGER
HYDROLOGY...
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
147 AM EDT THU JUN 13 2013
.SYNOPSIS...
THUNDERSTORM COMPLEX PASSES THROUGH OVERNIGHT. LOW PRESSURE AND
COLD FRONT PASS THURSDAY. HIGH PRESSURE FOR THE END OF WEEK AND
INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
1015 PM UPDATE...CONVECTION CONTINUES TO REMAIN MOSTLY NORTH OF
CWA...HOWEVER INCHING EVER SO SLIGHTLY SOUTH WITH TIME. CONTINUED
RELYING ON HRRR AND RAP GUIDANCE...BRINGING THUNDERSTORMS INTO
NORTHERN CWA OVER THE NEXT SEVERAL HOURS...AND DECREASED POPS
SOME ACROSS THE SOUTH UNTIL PRE-DAWN WHEN CONVECTING COMPLEX
FORMING NEAR SOUTHERN TIP OF LAKE MICHIGAN SHOULD BRING SHOWERS
AND STORMS THROUGH. HAVE THAT COMPLEX GETTING TO WESTERN CWA
BORDER 09-10Z...AND INTO THE WV MOUNTAINS 13-14Z. NO CHANGES MADE
TO DAYTIME GRIDS TOMORROW...GRIDS STILL ON PAR WITH ANOTHER ROUND
OF STORMS AS THE COLD FRONT PLOWS EAST.
PREVIOUS DISCUSSION...
GOING MORE AGGRESSIVE ON THIS FORECAST FOR BOTH SEVERE POTENTIAL THRU
EARLY TONIGHT...AND POTENTIAL WATER PROBLEMS NORTHEAST OVERNIGHT
INTO THURSDAY. ADMITTEDLY...ALTHOUGH MODELS ARE IN REASONABLE
AGREEMENT WITH THE MASS FIELDS...THEY ARE NOT WITH QPF FIELDS...WITH
THE PROBLEM BEING MESOSCALE INFLUENCES FROM PREVIOUS CONVECTIVE
COMPLEXES UPSTREAM. FIRST...AHEAD OF A STRONG LOW PRESSURE CENTER
AND COLD FRONT THAT WILL DROP SOUTHEAST ACROSS THE AREA LATE TONIGHT
AND THURSDAY...WE WILL BE IN NORTHWEST FLOW ALOFT WITH UPPER
DISTURBANCES. ALTHOUGH THE WARM FRONT WILL BE NORTH OF THE AREA AT
THE BEGINNING OF THIS PERIOD...THESE DISTURBANCES WILL BE MOVING
OVER VERY MOIST AND UNSTABLE AIR THIS AFTERNOON AND EVENING. WILL
INCLUDE MENTION OF SEVERE IN SCATTERED STORMS THRU THIS EVENING
EVERYWHERE GIVEN SPC SLIGHT RISK. ONE SUCH DISTURBANCE LOOKS TO BE
DROPPING SOUTHEAST OUT OF MICHIGAN THIS AFTERNOON...AND THINK THIS
WILL INITIATE A COMPLEX LATER THIS AFTERNOON THAT WILL DROP ACROSS
NORTHERN WEST VIRGINIA THIS EVENING AND EARLY TONIGHT. WILL TARGET
THIS AREA WITH BEST POPS THROUGH EARLY TONIGHT.
A BAND OF POTENTIALLY HEAVY CONVECTION WILL SPREAD AHEAD OF AND
ACCOMPANY THE COLD FRONT LATE TONIGHT AND THURSDAY...THOUGH NOT
LIKELY SEVERE. HOWEVER...THIS ADDED CONVECTION ON TOP OF THE WHAT
OCCURS OVERNIGHT IN THE NORTH AND EAST MAY BRING FLOODING PROBLEMS.
THUS...A FLASH FLOOD WATCH HAS BEEN ISSUED FOR THE NORTH AND EAST
PORTION OF OUR AREA FROM 00Z THRU 18Z THURSDAY.
CONDITIONS WILL BE WARM AND MUGGY TONIGHT...WITH TEMPS AROUND 70 FOR
LOWS. TEMPERATURES WILL BE COOLER THURSDAY IN THE CLOUDS AND
SHOWERS...ESPECIALLY IN THE WEST WHERE THE COLD FRONT WILL BE
PUSHING THOUGH.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY/...
FRONTAL BOUNDARY SHOULD BE OUT OF THE AREA BY 00Z FRIDAY. EXPECT
ANY LINGERING SHRA TO DEPART TO THE EAST BY MIDNIGHT. ASSOCIATED
H500 VORT MAX WILL SHARPEN UP THE TROUGH ALONG THE EASTERN SEABOARD
AND SLOW EASTERN PROGRESSION A BIT. THIS WILL ALLOW ANOTHER RIPPLE
TO DROP DOWN THE BACK SIDE IN NORTHERLY FLOW ON FRIDAY...ALONG WITH LOW
LEVEL MOISTURE...TO KEEP SOME CLOUDS AROUND ESPECIALLY IN THE
NORTHEASTERN CWA. NOT A LOT OF INSTABILITY SEEN IN BUFKIT SOUNDINGS
FRIDAY AFTERNOON...BUT THE NORTHERLY FLOW AND AMOUNT OF MOISTURE MAY
BE ENOUGH TO SQUEEZE OUT SPRINKLES OR LIGHT RAIN SHOWERS...AND
INCLUDED A MINIMAL POP. OTHERWISE...PARTLY TO MOSTLY SUNNY SKIES
ARE FORECAST WITH NEAR TO SLIGHTLY BELOW NORMAL TEMPERATURES.
WEAK HIGH PRESSURE IS IN PLACE FOR FRIDAY NIGHT AND SATURDAY...WITH
A NEEDED DRY BREAK FOR THE AREA. FRIDAY NIGHT WILL BE COOL...AND
SOME VALLEY FOG IS A POSSIBILITY. SEASONABLE TEMPERATURES ON
SATURDAY...WITH SOME HIGH CLOUDS STARTING TO ARRIVE IN THE AFTERNOON.
NO MAJOR CHANGES TO FORECAST TEMPERATURES.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
MODELS IN DECENT AGREEMENT IN DEAMPLIFYING...AND THEN
REESTABLISHING...THE EASTERN UPPER TROUGH DURING THE EXTENDED
PERIOD. DURING THE INTERVENING PERIOD OF ZONAL FLOW...A COUPLE OF
MIDLEVEL WAVES WILL BE RIDING ACROSS. THE FIRST WILL PUSH A WARM
FRONT THROUGH SATURDAY NIGHT INTO SUNDAY. THE SECOND...MORE
SIGNIFICANT DISTURBANCE WILL CROSS MONDAY/MONDAY NIGHT WITH A COLD
FRONT...AND WILL BE DISTURBANCE THAT DIGS THE TROUGH ONCE AGAIN.
THESE SYSTEMS WILL BE INDIVIDUALLY PROGRESSIVE...BUT RAIN TOTALS MAY
EVENTUALLY HAVE TO BE WATCHED ESPECIALLY IN AREAS THAT GET THE MOST
RAIN FROM THE SYSTEM TONIGHT AND TOMORROW. HIGH PRESSURE THEN
RETURNS WEDNESDAY WITH DRY WEATHER.
USED HPC GRIDDED GUIDANCE HEAVILY FOR THIS PERIOD. SUGGESTED
TEMPERATURES WERE NOT FAR FROM MEX/ENSEMBLE NUMBERS AND DID NOT
STRAY FAR FROM SEASONAL NORMS...WHICH SEEMED REASONABLE.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
SEVERAL FORECAST CHALLENGES THROUGH THE TAF PERIOD. FIRST CONVECTIVE
COMPLEX MOVES THROUGH BETWEEN 08Z AND 12Z THIS MORNING...VERY
GUSTY WINDS 30 TO 40KTS WILL ACCOMPANY THIS COMPLEX. THIS WILL
AFFECT HTS TO CRW LINE AND NORTH. MVFR TO IFR CONDITIONS POSSIBLE
WITH THIS COMPLEX AS WELL. THEN ANOTHER ROUND OF STORMS WITH THE
COLD FRONT THURSDAY AFTERNOON. IFR AND GUSTY WINDS POSSIBLE IN ANY
STRONGER CELLS THROUGH THE ENTIRE PERIOD...WITH MVFR CEILINGS
AROUND AND BEHIND THE COLD FRONT. VFR CONDITIONS RETURN AFT 04Z
FRIDAY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z FRIDAY...
FORECAST CONFIDENCE...MEDIUM TO LOW.
ALTERNATE SCENARIOS: TIMING AND LOCATION OF THUNDERSTORM COMPLEX
AND COLD FRONT COULD VARY...ALONG WITH THE LOWER CATEGORY
CEILINGS THAT WILL BE LEFT BEHIND THE STORMS.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE THU 06/13/13
UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
EDT 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13
CRW CONSISTENCY H H M M M M M M M M M H
HTS CONSISTENCY H H M M M M M M M M M H
BKW CONSISTENCY H M M M M M M M M M M H
EKN CONSISTENCY L H H H H H H H H H H H
PKB CONSISTENCY M M M L L L L M M H H H
CKB CONSISTENCY L M M L L L L L H H H H
AFTER 06Z FRIDAY...
LINGERING IFR POSSIBLE IN THE NORTHERN MOUNTAINS THROUGH FRIDAY NIGHT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FLASH FLOOD WATCH THROUGH THIS AFTERNOON FOR WVZ009>011-
016>020-027>032-037>040-046-047.
OH...FLASH FLOOD WATCH THROUGH THIS AFTERNOON FOR OHZ076.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...JMV/CL
NEAR TERM...JMV/MZ
SHORT TERM...CL
LONG TERM...CL
AVIATION...JS
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1219 AM EDT THU JUN 13 2013
.SYNOPSIS...
A WARM FRONT WILL BECOME NEARLY STATIONARY ACROSS NORTHERN OHIO AND
NORTHERN PENNSYLVANIA THROUGH THURSDAY MORNING AS LOW PRESSURE MOVES
EAST ALONG THE FRONT. HIGH PRESSURE WILL BUILD SOUTH ACROSS THE AREA
BY SATURDAY MORNING AND TO THE CAROLINA COAST BY SATURDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
UPDATED FOR WATCH. THE MAIN THREAT IS MOVING INTO NW
OHIO...HOWEVER...SOME CONVECTION AHEAD OF THIS LINE MAY BE SEVERE
OR TORNADIC.
PREVIOUS...
UPDATED FOR SEVERE WATCH. CONVECTION NOW DEVELOPING IN IOWA AND
ILLINOIS. THIS IS EXPECTED TO DEVELOP INTO A SQUALL LINE THAT WILL
MOVE INTO WESTERN OHIO LATE THIS EVENING TO AROUND MIDNIGHT. IF
CONVECTION DEVELOPS AHEAD OF THE LINE...IT TOO COULD BECOME
SEVERE. THIS IS A PDS WATCH WITH THE EXPECTATION OF THUNDERSTORMS
CONTAINING DAMAGING WINDS IN EXCESS OF 65 KTS. THERMODYNAMICS
BACKS THIS UP WITH DRY AIR ALOFT CONTRIBUTING TO DOWNDRAFT CAPES
OVER 1000K/KG. SHEAR PROFILES ALSO SUGGEST FORWARD PROPAGATION
ADDING TO WIND POTENTIAL. ROTATING SUPERCELLS ALSO SUPPORTED SO
TORNADOES ARE ALSO POSSIBLE.
PREVIOUS...THE WAITING GAME BEGINS. SO FAR ATMOSPHERE APPEARS TO
BE WELL CAPPED AND IS SUPPRESSING CONVECTION FROM DEVELOPING
UPSTREAM. THE OTHER ISSUE AT HAND IS THE EXTENSIVE DEBRIS CLOUDS
HANGING AROUND. WE NEVER CLEARED OUT OR HAD ANY BREAKS IN THE
OVERCAST AS EXPECTED AND THIS IS ALSO LIMITING ANY DEVELOPMENT
OVER THE REGION.
COORDINATED WITH COFORECASTER...IT APPEARS AN AREA OF CONVERGENCE
HAS SET UP BACK OVER EASTERN IOWA AND NORTHWEST ILLINOIS AT THIS
TIME AND THIS COULD VERY WELL BE THE LOCATION THE THUNDERSTORMS
DEVELOP. LATEST HRRR MODEL SHOWS CONVECTION FIRING OVER THIS AREA AS
WELL AND HAS BEEN PRETTY CONSISTENT FROM RUN TO RUN TODAY. THERE IS
THE POSSIBILITY THAT ACTIVITY COULD DEVELOP AHEAD OF THE MAIN LINE
AS INDIVIDUAL CELLS OVERNIGHT.
LATEST SURFACE ANALYSIS SHOWS DEWPOINT TEMPERATURES RISING INTO THE
LOWER 70S INTO THE SOUTHWEST PORTION OF THE FORECAST AREA AT THIS
TIME. WE SHOULD CONTINUE TO SEE A SURGE OF THE HIGHER DEWPOINT AIR
INTO THE FORECAST AREA AS THE EVENING PROGRESSES. THIS WILL HELP TO
INCREASE THE MOISTURE ACROSS THE REGION PRIMING THE ATMOSPHERE FOR
THE POTENTIAL FOR HEAVY RAIN THAT WE HAVE BEEN EXPECTING.
THE SURGE OF STRONG STORMS WILL ENTER THE AREA AND COULD POSSIBLY
EVOLVE INTO AN OVERRUNNING SITUATION ALONG THE STATIONARY FRONT LATE
TONIGHT. THE SEVERE THREAT WILL TRANSITION INTO A POTENTIAL FLOODING
THREAT WITH LOCALLY HEAVY RAIN FROM THE THUNDERSTORMS. THUNDERSTORMS
WILL BE EFFICIENT RAIN PRODUCERS AND AREAS COULD SEE SUBSTANTIAL
PONDING OF WATER OVERNIGHT ALONG WITH THE RAPID RISES OF RIVERS AND
STREAMS. SEE HYDRO SECTION BELOW.
TROPICAL AIR MASS OVER THE REGION WILL BE ACROSS THE SOUTHERN HALF
OF THE FORECAST AREA. NORTHERN HALF OF THE AREA WILL REMAIN NORTH OF
THE STATIONARY FRONT MOST OF THE NIGHT. AS THE LOW PRESSURE SYSTEM
MOVES EAST...IT WILL PUSH THE FRONT NORTH TO THE LAKE SHORE AS A
WARM FRONT. TEMPERATURES OVERNIGHT IN THE LOWER 70S SOUTH AND UPPER
60S IN THE NORTH.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY NIGHT/...
LOW PRESSURE IS PROGGED TO PULL OUT TO THE EAST THURSDAY MORNING AS
UPPER LEVEL AMPLIFIED RIDGE BUILDS EAST FORCING UPPER LEVEL TROUGH
OFF THE COAST. AS SURFACE LOW MOVES EAST...ASSOCIATED MOISTURE AND
SUBSEQUENT PRECIPITATION WILL EXIT TO THE EAST AS WELL. HIGH
PRESSURE AT THE SURFACE PUSHES SOUTHEAST ACROSS THE AREA FORCING
DRIER AIR INTO THE REGION FOR THURSDAY NIGHT INTO FRIDAY.
THE HIGH WILL MOVE SOUTHEAST TO THE CAROLINA COAST BY SATURDAY NIGHT
AND THIS WILL SET UP ANOTHER RETURN SOUTHERLY FLOW TO THE FORECAST
AREA. A FAIRLY FAST MOVING SHORTWAVE TROUGH AND ASSOCIATED MOISTURE
WILL BEGIN TO MOVE EAST INTO THE FORECAST AREA SATURDAY INTO
SATURDAY NIGHT AND COULD BRING ANOTHER ROUND OF SHOWERS TO THE
FORECAST AREA.
COLD AIR ADVECTION ASSOCIATED WITH THE HIGH PRESSURE WILL OCCUR ON
THURSDAY BUT WILL BE SHORT LIVED AS HIGH MOVES TO THE SOUTHEAST. AS
MENTIONED EARLIER...RETURN SOUTHERLY FLOW WILL BRING TEMPERATURES
BACK UP INTO THE MIDDLE 70S EAST AND UPPER 70S TO LOWER 80S WEST BY
SATURDAY. LOWS DIPPING BACK TO THE 50S THURSDAY AND FRIDAY NIGHTS.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
A RIPPLE OF LOW PRESSURE WILL BE MOVING INTO THE REGION ON SUNDAY
WITH SCATTERED THUNDERSTORMS POSSIBLE...ESPECIALLY SUNDAY AFTERNOON.
THE MODELS ARE THEN STRUGGLING WITH THE TIMING OF ANOTHER WAVE THAT
MAY MOVE INTO THE CENTRAL GREAT LAKES ON MONDAY. SO AFTER A BRIEF
LULL IN THUNDERSTORM ACTIVITY LATE SUNDAY NIGHT INTO MONDAY MORNING
WE SHOULD SEE THUNDERSTORM CHANCES RETURN MONDAY AFTERNOON AND
EVENING. THERE MAY BE SOME LINGERING LIGHT SHOWERS OR THUNDERSTORMS
TUESDAY AS HIGH PRESSURE BEGINS TO BUILD INTO THE REGION LATE.
TEMPERATURES THROUGH THE EXTENDED WILL BE WITHIN A FEW DEGREES OF
SEASONAL AVERAGES.
&&
.AVIATION /04Z THURSDAY THROUGH MONDAY/...
A WEST TO EAST ORIENTED FRONTAL BOUNDARY WILL REMAIN
QUASISTATIONARY ACROSS CENTRAL OHIO TODAY. A LOW PRESSURE
DISTURBANCE OVER NORTHERN ILLINOIS WILL MAKE ITS WAY EAST ALONG
THIS BOUNDARY TONIGHT...INITIATING THUNDERSTORMS ACROSS THE
FORECAST AREA TONIGHT INTO THURSDAY. THUNDERSTORMS MAY REACH THE
WESTERN TAF SITES SOMETIME AROUND 22Z. THERE IS A CHANCE THAT THIS
DISTURBANCE WILL BECOME FORWARD PROPAGATING...MOVING QUICKLY
THROUGH THE FORECAST AREA. IF THIS OCCURS...A SUBSTANTIAL GUST
FRONT COULD DEVELOP ALONG THE LEADING EDGE OF THE DISTURBANCE.
WILL MONITOR THE THREAT OVER THE NEXT COUPLE OF HOURS TO DETERMINE
WHETHER OR NOT TO ADD A VARIABLE WIND GUST TO TAFS FOR THE 00-04Z
TIME FRAME.
SHOWERS WILL ACCOMPANY THE THUNDERSTORMS THIS EVENING AND WILL
LIKELY PERSIST INTO THURSDAY AS A COLD FRONT MOVES INTO THE AREA.
CEILINGS WILL LOWER TO MVFR OVERNIGHT AND IFR THURSDAY MORNING. MOST
OF THE RAIN WILL OCCUR OVERNIGHT AND EARLY THURSDAY MORNING...WITH
VISIBILITIES DROPPING TO MVFR IN THE HEAVIEST SHOWERS.
CEILINGS WILL BEGIN TO LIFT AND RAIN WILL BEGIN TO CLEAR OUT EARLY
THURSDAY AFTERNOON TOWARDS THE END OF THE TAF PERIOD.
.OUTLOOK...NON VFR CONDITIONS POSSIBLE THURSDAY NIGHT AND SATURDAY
NIGHT AND SUNDAY IN SHOWERS AND THUNDERSTORMS.
&&
.MARINE...
SCATTERED SHOWERS CONTINUE OVER LAKE ERIE THIS AFTERNOON WITH WINDS
VARYING FROM A NORTHEAST TO SOUTHEAST DIRECTION. LATER TONIGHT...A
LOW PRESSURE SYSTEM WILL MOVE EAST ALONG A QUASISTATIONARY BOUNDARY
LYING ACROSS CENTRAL OHIO. SHOWERS AND THUNDERSTORMS WILL
ACCOMPANY THE DISTURBANCE. SOME OF THE THUNDERSTORMS MAY BECOME
SEVERE...WARRANTING A SPECIAL MARINE WARNING.
SHOWERS ARE EXPECTED TO CONTINUE INTO THURSDAY AHEAD OF A COLD
FRONT. MOST OF THE SHOWERS WILL OCCUR OVERNIGHT INTO THURSDAY
MORNING. WINDS WILL INCREASE IN SPEED WITH THE PASSAGE OF THE COLD
FRONT THURSDAY NIGHT. MODELS ARE STILL A BIT UNCERTAIN WITH HOW
STRONG WINDS WILL GET...WHICH WILL AFFECT WAVE HEIGHTS. FOR NOW IT
DOES NOT APPEAR THAT A SMALL CRAFT ADVISORY WILL BE NECESSARY...BUT
THE NEXT FORECAST SHIFT WILL CONTINUE TO MONITOR THE SITUATION.
HIGH PRESSURE WILL BUILD OVER THE LAKE FRIDAY NIGHT AND MOVE EAST
LATE SATURDAY NIGHT. AS THE HIGH MOVES EAST...WINDS WILL TURN TO THE
SOUTHWEST AND PICK UP SPEED. A LOW PRESSURE SYSTEM AND ASSOCIATED
COLD FRONT WILL APPROACH THE AREA ON MONDAY.
&&
.HYDROLOGY...
A FLOOD WATCH IS IN EFFECT FOR THE ENTIRE AREA FROM THE HEAVY
RAINFALL EXPECTED OVERNIGHT AND EARLY THURSDAY. MOISTURE ADVECTION
WILL INCREASE OVER THE AREA THIS AFTERNOON AND NOTABLY OVERNIGHT AS
AN AREA OF LOW PRESSURE MOVES INTO THE REGION FROM THE WEST. THERE
IS SOME INDICATION THAT PRECIPITABLE WATER VALUES COULD REACH 2.0"
WHICH IS ANOMALOUSLY HIGH FOR THIS TIME OF YEAR. THE SHOWERS WILL BE
EFFICIENT RAIN MAKERS AND COULD DROP A QUICK INCH TO AN AREA. THE
THREAT OF TRAINING STORMS IS HIGH SUGGESTING THE THREAT OF A QUICK 2
TO 3 INCHES OF RAIN IS POSSIBLE. RAINFALL RATES THIS HIGH COULD
PRODUCE FLASH FLOODING. THE HEAVIEST RAIN WILL FALL BETWEEN 10 PM
TONIGHT AND 8 AM THURSDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...FLOOD WATCH THROUGH THIS AFTERNOON FOR OHZ011>014-020>023-
031>033-038-089.
FLOOD WATCH THROUGH THIS AFTERNOON FOR OHZ003-006>010-017>019-
027>030-036-037-047.
PA...FLOOD WATCH THROUGH THIS AFTERNOON FOR PAZ001>003.
MARINE...NONE.
&&
$$
SYNOPSIS...LOMBARDY
NEAR TERM...KIELTYKA/TK/LOMBARDY
SHORT TERM...LOMBARDY
LONG TERM...MULLEN
AVIATION...MULLEN/YEAGER
MARINE...MULLEN/YEAGER
HYDROLOGY...
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1219 PM EDT THU JUN 13 2013
.SYNOPSIS...
A STORMS SYSTEM OVER NWRN PA EARLY TODAY WILL MOVE OFF THE COAST
TONIGHT. A LARGE HIGH PRESSURE SYSTEM WILL BUILD INTO THE REGION
FOR SATURDAY BEFORE A NEW FRONTAL SYSTEM BRINGS A RETURN OF
CLOUDS AND SHOWERS SUNDAY INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE LINE OF STRONG STORMS THAT BROUGHT THE HEAVY RAIN AND HIGH
WINDS EARLY TODAY HAS MOVED TO THE NJ COAST. THE SURFACE AND
UPPER LOW THAT TRIGGERED THE LINE ARE STILL MEANDERING THROUGH THE
REGION WITH VERY WARM AND HUMID AIR STILL IN PLACE. THE BIG
QUESTION IS IF WE CAN SEE THE ATMOSPHERE RECOVER IN TIME FOR NEW
CONVECTION TO BECOME AN ISSUE...MAINLY OVER SOUTHERN AREAS AS THE
SFC LOW SLIDES EAST OR SOUTHEAST. MESO MODELS ARE SHOWING THE BEST
CHANCE OF THE CONVECTION REMAINING JUST SOUTH OF THE BORDER...BUT
A FAIR AMOUNT OF SHOWER ACTIVITY LINGERING OR REDEVELOPING OVER
THE REGION. CONCERN IS THE BINOVC/CLEARING THAT IS DEVELOPING OVER
THE LOWER SUSQ COULD RAISE THE THREAT. THE RAP SHOWS CAPES
REBOUNDING IN THAT AREA AS WELL. THIS WILL BE THE AREA OF MOST
CONCERN IN THE CWA FOR THE NEXT SEVERAL HOURS.
HAVE DROPPED THE FLOOD WATCH FOR ALL BUT THE SERN 3 COUNTIES
SINCE IT LOOKS LIKE THE THREAT FOR HEAVIEST RAIN WILL REMAIN SOUTH
OF OUR BORDER. IF IT BUILDS BACK TO THE NORTH AT ALL...THOSE
COUNTIES WOULD BE MOST UNDER THE GUN.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
THE LOW WILL MOVE OFF TO OUR EAST OVERNIGHT BRINGING A DIMINISHING
THREAT OF SHOWERS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
NOT A LOT OF CHANGE FROM YESTERDAY.
DID EXTEND THE MENTION OF SHOWERS INTO FRIDAY AFT...GIVEN
SECONDARY COLD FRONT DROPPING SE...AND COLD AIR ALOFT.
SATURDAY STILL LOOKS TO BE THE BETTER DAY THIS WEEKEND.
DID BRING SHOWERS AND STORMS INTO THE AREA SUNDAY MORNING
NOW...IN LINE WITH OTHER OFFICES AND NEW GUIDANCE.
STILL A CHC OF SHOWERS AND STORMS ON MONDAY...AS WE ARE IN
THE WARM SECTOR...BUT WEAK WAVES ALOFT MOVING IN.
COLD FRONT MOVES INTO PA ON TUE...STILL A CHC OF SHOWERS
AND STORMS.
WENT WITH A DRY DAY ON WED...WITH COOLER TEMPS.
&&
.AVIATION /16Z THURSDAY THROUGH MONDAY/...
THE REGION WILL CONTINUE TO BE AFFECTED BY THE ABNORMALLY INTENSE
STORM CURRENTLY OVER NWRN PA. WIDESPREAD SHOWERS AND MVFR/IFR WILL
CONTINUE TO NEGATIVELY IMPACT TERMINALS INTO THE LATE DAY AND
EVENING BEFORE DRIER AIR BEGINS TO MOVE IN. THE WIND WILL BE
CHANGEABLE AND GUSTY TODAY AS THE LOW MOVES ACROSS THE REGION.
EXPECT SOME IMPROVEMENT TONIGHT IN MOST AREAS...BUT HIGH TERRAIN
SITES COULD REMAIN WITH MVFR/IFR CEILINGS AND SOME FOG AS WINDS
DROP OFF.
OUTLOOK...
FRI...CHANCE OF SHOWERS...MAINLY EARLY. PRIMARILY VFR CONDITIONS.
SAT...NO SIG WX.
SUN-MON...MAINLY VFR WITH SCATTERED SOWERS AND THUNDERSTORMS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR PAZ064>066.
&&
$$
SYNOPSIS...LA CORTE/LAMBERT
NEAR TERM...LA CORTE/LAMBERT
SHORT TERM...LA CORTE/LAMBERT
LONG TERM...GARTNER
AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1147 AM EDT THU JUN 13 2013
.SYNOPSIS...
A STORMS SYSTEM OVER NWRN PA EARLY TODAY WILL MOVE OFF THE COAST
TONIGHT. A LARGE HIGH PRESSURE SYSTEM WILL BUILD INTO THE REGION
FOR SATURDAY BEFORE A NEW FRONTAL SYSTEM BRINGS A RETURN OF
CLOUDS AND SHOWERS SUNDAY INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE LINE OF STRONG STORMS THAT BROUGHT THE HEAVY RAIN AND HIGH
WINDS EARLY TODAY HAS MOVED TO THE NJ COAST. THE SURFACE AND
UPPER LOW THAT TRIGGERED THE LINE ARE STILL MEANDERING THROUGH THE
REGION WITH VERY WARM AND HUMID AIR STILL IN PLACE. THE BIG
QUESTION IS IF WE CAN SEE THE ATMOSPHERE RECOVER IN TIME FOR NEW
CONVECTION TO BECOME AN ISSUE...MAINLY OVER SOUTHERN AREAS AS THE
SFC LOW SLIDES EAST OR SOUTHEAST. MESO MODELS ARE SHOWING THE BEST
CHANCE OF THE CONVECTION REMAINING JUST SOUTH OF THE BORDER...BUT
A FAIR AMOUNT OF SHOWER ACTIVITY LINGERING OR REDEVELOPING OVER
THE REGION. CONCERN IS THE BINOVC/CLEARING THAT IS DEVELOPING OVER
THE LOWER SUSQ COULD RAISE THE THREAT. THE RAP SHOWS CAPES
REBOUNDING IN THAT AREA AS WELL. THIS WILL BE THE AREA OF MOST
CONCERN IN THE CWA FOR THE NEXT SEVERAL HOURS.
HAVE DROPPED THE FLOOD WATCH FOR ALL BUT THE SERN 3 COUNTIES
SINCE IT LOOKS LIKE THE THREAT FOR HEAVIEST RAIN WILL REMAIN SOUTH
OF OUR BORDER. IF IT BUILDS BACK TO THE NORTH AT ALL...THOSE
COUNTIES WOULD BE MOST UNDER THE GUN.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
THE LOW WILL MOVE OFF TO OUR EAST OVERNIGHT BRINGING A DIMINISHING
THREAT OF SHOWERS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
NOT A LOT OF CHANGE FROM YESTERDAY.
DID EXTEND THE MENTION OF SHOWERS INTO FRIDAY AFT...GIVEN
SECONDARY COLD FRONT DROPPING SE...AND COLD AIR ALOFT.
SATURDAY STILL LOOKS TO BE THE BETTER DAY THIS WEEKEND.
DID BRING SHOWERS AND STORMS INTO THE AREA SUNDAY MORNING
NOW...IN LINE WITH OTHER OFFICES AND NEW GUIDANCE.
STILL A CHC OF SHOWERS AND STORMS ON MONDAY...AS WE ARE IN
THE WARM SECTOR...BUT WEAK WAVES ALOFT MOVING IN.
COLD FRONT MOVES INTO PA ON TUE...STILL A CHC OF SHOWERS
AND STORMS.
WENT WITH A DRY DAY ON WED...WITH COOLER TEMPS.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
A LINE OF SHOWERS AND THUNDERSTORMS ALONG AN INCOMING BOUNDARY
WILL MOVE THROUGH THE TAF SITES FROM WEST TO EAST THIS MORNING.
THIS LINE WILL MOVE THROUGH MDT AND LNS BY 13Z. THIS LINE WILL
EXIT THE CWA SHORTLY AFTER. THE BACK EDGE OF THE LINE IS MOVING
THROUGH...ALLOWING FOR BRIEFLY BETTER CONDITIONS. THE COPIOUS
AMOUNTS OF LOW PRESSURE WILL ALLOW FOR IFR CIGS AT BFD...WITH THE
REST OF THE TAF POINTS HAVING PERIODS OF MVFR CIGS AND VSBYS.
EXPECT THIS POTENT LOW PRESSURE SYSTEM WILL REDUCE CONDS WITH THE
POTENTIAL FOR LARGE IMPACTS FROM STRONG THUNDERSTORMS AND WIND
SHEAR THROUGH THIS AFTERNOON AND EARLY EVENING..BEFORE MOVING EASTWARD BY
TONIGHT. EXPECT DAYTIME GUSTY WINDS AS HIGH AS 25KTS FROM THE
WEST.
OUTLOOK...
THU NIGHT...LARGE IMPACTS FROM STRONG TSTMS AND WIND SHEAR LIKELY.
OTHERWISE SHOWERS CONTINUE. REDUCTIONS ALL AREAS THU AFT-
EVE...THEN WIDESPREAD REDUCTIONS NW HALF THU NIGHT.
FRI...CHANCE OF SHOWERS...MAINLY EARLY. PRIMARILY VFR CONDITIONS.
SAT...NO SIG WX.
SUN...MAINLY VFR WITH SCATTERED SOWERS AND THUNDERSTORMS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR PAZ004>006-010>012-
017>019-024>028-033>037-041-042-045-046-049>053-056>059-
063>066.
&&
$$
SYNOPSIS...LA CORTE/LAMBERT
NEAR TERM...LA CORTE/LAMBERT
SHORT TERM...LA CORTE/LAMBERT
LONG TERM...GARTNER
AVIATION...CERU/GARTNER
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1047 PM CDT FRI JUN 14 2013
.UPDATE...
ISSUED AT 855 PM CDT FRI JUN 14 2013
THREAT FOR TORNADOES HAVE WANED ACROSS THE AREA AS OUTFLOW
BOUNDARY HAS STABILIZED THE NEAR SURFACE ENVIRONMENT IN THE
VICINITY OF SIOUX CITY. HOWEVER...AS WEAK UPPER WAVE MOVES INTO NW
IA...ELEVATED THUNDERSTORMS HAVE DEVELOPED IN NW IA. 00Z RAP SHOWS
THAT THERE IS 2000 TO 3000 J/KG OF MUCAPE AVAILABLE TO WORK WITH
BUT THE EFFECTIVE SHEAR IS AROUND 30 KTS AND DROPS THROUGH THE
EVENING. SO AT THIS POINT...DO NOT EXPECT ELEVATED SUPERCELLS BUT
AN ISOLATED MULTICELL STORM COULD PRODUCE QUARTER TO HALF DOLLAR
SIZE HAIL THROUGH MIDNIGHT IN NORTHWEST IOWA. HAVE RAISED POPS TO
50 TO 70 PERCENT WITH THIS ACTIVITY. LATER TONIGHT...NAM AND RAP
BOTH SUGGEST THAT CONVERGENCE ALONG THE 850 MB FRONT WILL RESULT
IN MORE CONVECTIVE DEVELOPMENT FROM CENTRAL NEBRASKA INTO NORTHWEST
IOWA. AM A LITTLE CONCERNED THAT ONGOING CONVECTION OVER ERN
NEBRASKA MAY RESULT IN THIS CONVECTION FOCUSING A BIT FARTHER
SOUTH AS 850 MB JET INTERACTS WITH REINFORCED OUTFLOW BOUNDARY.
BUT ENOUGH UNCERTAINTY AT THIS POINT THAT WILL CONTINUE 50 POPS IN
NW IA AND NE NEBRASKA LATE TONIGHT. WITH CLOUDS AND AMPLE MOISTURE
OVER THE MUCH OF THE AREA...LOWS SHOULD REMAIN IN THE 60S. THE
ONLY EXCEPTION MAY BE TOWARD 9V9 AND HON. WITH KPIR AND KMBG DEW
POINTS IN THE MID 50S...NORTHERLY FLOW SHOULD BRING SOME OF THIS
DRY AIR INTO PORTIONS OF CENTRAL SD SO WILL DROP LOWS A COUPLE OF
DEGREES INTO THE UPPER 50S.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 325 PM CDT FRI JUN 14 2013
SEVERE THUNDERSTORM THREAT STILL EXISTS OVER THE AREA LATE THIS
AFTERNOON AND EVENING. CONVERGENCE IS STRENGTHENING AT/NEAR THE
SURFACE OVER NORTHEAST NEBRASKA AND THIS CONVERGENCE COUPLED WITH A
BOUNDARY THAT EXTENDS SOUTH OF THERE SHOULD PROVIDE A FOCUS FOR
THUNDERSTORM DEVELOPMENT. VIRTUALLY ALL OF THE MODELS...INCLUDING
THE HIGH RESOLUTION MODELS SUGGEST THIS AREA FOR DEVELOPMENT AND
ONLY DIFFER ON HOW FAR NORTH THE STRONG UPDRAFTS WILL BE. SUSPECT
THAT DEVELOPMENT WILL OCCUR IN NORTHWEST KANSAS TO CENTRAL NEBRASKA
THEN WORK NORTHEAST. WHILE CAPPING WILL NEED TO BE OVERCOME...LIKELY
NEEDING HIGH TEMPERATURES CLOSE TO 95 DEGREES...IF ANYTHING COULD
DEVELOP IT SHOULD QUICKLY BECOME SEVERE. MODELS STILL HINTING AT
SURFACE BASED CAPE VALUES OF 3000 TO 3500 J/KG WITH DEEP LAYER SHEAR
OF ABOUT 30 TO 35 KNOTS. THE SURFACE TO 1 KM SHEAR ALSO SUGGESTED TO
BE AROUND 20 KNOTS SO A TORNADO WOULD BE POSSIBLE. AT THIS TIME
DAKOTA AND DIXON COUNTIES APPEAR TO HAVE THE HIGHEST THREAT FOR
TORNADOES IN THE SIOUX FALLS CWA. THERE HAVE BEEN SOME HINTS THAT
SOME SHOWERS AND THUNDERSTORMS COULD DEVELOP OVER THE FAR WESTERN
CWA AS THE UPPER LEVEL SUPPORTS SWINGS INTO THE AREA BUT WILL NOT
INCLUDE ANY CHANCES YET AS CONFIDENCE IN THAT IS TOO LOW.
THE CHANCE FOR SHOWERS AND THUNDERSTORMS WILL CONTINUE IN THE FAR
SOUTHERN CWA ON SATURDAY AS THE UPPER LEVEL WAVE MOVES THROUGH.
INSTABILITY AND SHEAR MUCH WEAKER ON SATURDAY SO MORE GENERAL
CHANCES WITH NO SEVERE THUNDERSTORMS EXPECTED.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 325 PM CDT FRI JUN 14 2013
PRECIP CHANCES ACROSS NORTHWEST IOWA APPEAR TO WANE FAIRLY RAPIDLY
SATURDAY EVENING WITH SURFACE BOUNDARY AND CONVECTION EXPECTED TO
FOCUS ALONG AND SOUTH OF I-80. SURFACE RIDGE NOSES INTO THE
REGION...RESULTING IN GOOD RADIATIVE CONDITIONS.
SURFACE RIDGE BEGINS TO DRIFT TO THE SOUTH AND EAST ON SUNDAY WITH
INSTABILITY ALOFT STARTING TO CREEP INTO SOUTH CENTRAL SOUTH
DAKOTA. INSTABILITY APPEARS TO BE FAIRLY CAPPED WITH WARM LAYER
NEAR 700 MB. WHILE ELEVATED INSTABILITY CREEPS NORTHWARD THROUGHOUT
THE DAY...CAP ONLY WEAKENS SUBSTANTIALLY ENOUGH ALONG THE MISSOURI
RIVER VALLEY WITH LACK OF STRONG UPPER LEVEL SUPPORT. MAY GET A
LITTLE SUPPORT FROM RIGHT REAR QUADRANT OF STRENGTHENING JET
STREAK...BUT STILL MAY BE DIFFICULT TO OVER COME 60-100 J/KG OF
ELEVATED CIN. AS SUCH...LEFT SLIGHT CHANCE/LOW CHANCE POPS
THROUGHOUT THE DAY BUT AM EXPECTING THE FOCUS TO BE SOUTH OF THE
FORECAST AREA.
AS COLD FRONT WORKS THROUGH THE AREA SUNDAY NIGHT HAVE SLIGHT
CHANCE/LOW END CHANCE POPS MAINLY ACROSS NORTHWEST IOWA AND ADJACENT
AREAS. STILL NOT A TON OF INSTABILITY TO WORK WITH...SO IF ANYTHING
DEVELOPS EXPECTING MAINLY GENERAL THUNDERSTORMS WITH JUST AN
ISOLATED THREAT OF SEVERE WEATHER AT BEST.
SURFACE RIDGE BUILDS BACK INTO THE AREA MONDAY INTO TUESDAY CREATING
RELATIVELY QUIET BENIGN WEATHER FOR MID JUNE. WINDS APPEAR TO BE
FAIRLY LIGHT WITH DEW POINTS IN THE MID AND UPPER 50S.
THEREAFTER...A SERIES OF SHORTWAVES MOVE ACROSS THE NORTHERN PLAINS
WEDNESDAY AND BEYOND ORIGINATING FROM THE UPPER LOW OVER THE PACIFIC
NORTHWEST. TIMING OF THE WAVES IS DIFFICULT THAT FAR OUT...SO LEFT
POPS SIMILAR TO GUIDANCE WITH FOCUS MORE TOWARDS THE END OF THE
PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1047 PM CDT FRI JUN 14 2013
VFR CONDITIONS WILL PREVAIL AT THE KHON TAF SITE. OTHERWISE...A
SURFACE TROUGH WILL SLOWLY MOVE SOUTHWARD ACROSS SOUTHEAST
SODAK AND INTO NORTHWEST IOWA TONIGHT. WINDS WILL TURN OUT OF THE
NORTHEAST AS IT PASSES KFSD/KSUX. FORECAST MODELS ARE SHOWING SOME
LOW LVL MOISTURE RESULTING IN MVFR/IFR VSBYS/CIGS ALONG AND SOUTH OF
THIS BOUNDARY BY 08/09Z. CONFIDENCE IS LOW...ESPECIALLY AT KFSD OF
THESE CONDITIONS BECOMING WIDESPREAD. THE TROUGH WILL STALL
ACROSS NORTHWEST IOWA TONIGHT AND SHRA/TSRA ARE EXPECTED TO
DEVELOP AND AFFECT THE KSUX SATURDAY MORNING. THE TROUGH WILL SINK
SOUTH LATE SATURDAY AFTERNOON AS WINDS TURN NNW.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...SCHUMACHER
SHORT TERM...08
LONG TERM...
AVIATION...
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
856 PM CDT FRI JUN 14 2013
.UPDATE...
ISSUED AT 855 PM CDT FRI JUN 14 2013
THREAT FOR TORNADOES HAVE WANED ACROSS THE AREA AS OUTFLOW
BOUNDARY HAS STABILIZED THE NEAR SURFACE ENVIRONMENT IN THE
VICINITY OF SIOUX CITY. HOWEVER...AS WEAK UPPER WAVE MOVES INTO NW
IA...ELEVATED THUNDERSTORMS HAVE DEVELOPED IN NW IA. 00Z RAP SHOWS
THAT THERE IS 2000 TO 3000 J/KG OF MUCAPE AVAILABLE TO WORK WITH
BUT THE EFFECTIVE SHEAR IS AROUND 30 KTS AND DROPS THROUGH THE
EVENING. SO AT THIS POINT...DO NOT EXPECT ELEVATED SUPERCELLS BUT
AN ISOLATED MULTICELL STORM COULD PRODUCE QUARTER TO HALF DOLLAR
SIZE HAIL THROUGH MIDNIGHT IN NORTHWEST IOWA. HAVE RAISED POPS TO
50 TO 70 PERCENT WITH THIS ACTIVITY. LATER TONIGHT...NAM AND RAP
BOTH SUGGEST THAT CONVERGENCE ALONG THE 850 MB FRONT WILL RESULT
IN MORE CONVECTIVE DEVELOPMENT FROM CENTRAL NEBRASKA INTO NORTHWEST
IOWA. AM A LITTLE CONCERNED THAT ONGOING CONVECTION OVER ERN
NEBRASKA MAY RESULT IN THIS CONVECTION FOCUSING A BIT FARTHER
SOUTH AS 850 MB JET INTERACTS WITH REINFORCED OUTFLOW BOUNDARY.
BUT ENOUGH UNCERTAINTY AT THIS POINT THAT WILL CONTINUE 50 POPS IN
NW IA AND NE NEBRASKA LATE TONIGHT. WITH CLOUDS AND AMPLE MOISTURE
OVER THE MUCH OF THE AREA...LOWS SHOULD REMAIN IN THE 60S. THE
ONLY EXCEPTION MAY BE TOWARD 9V9 AND HON. WITH KPIR AND KMBG DEW
POINTS IN THE MID 50S...NORTHERLY FLOW SHOULD BRING SOME OF THIS
DRY AIR INTO PORTIONS OF CENTRAL SD SO WILL DROP LOWS A COUPLE OF
DEGREES INTO THE UPPER 50S.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 325 PM CDT FRI JUN 14 2013
SEVERE THUNDERSTORM THREAT STILL EXISTS OVER THE AREA LATE THIS
AFTERNOON AND EVENING. CONVERGENCE IS STRENGTHENING AT/NEAR THE
SURFACE OVER NORTHEAST NEBRASKA AND THIS CONVERGENCE COUPLED WITH A
BOUNDARY THAT EXTENDS SOUTH OF THERE SHOULD PROVIDE A FOCUS FOR
THUNDERSTORM DEVELOPMENT. VIRTUALLY ALL OF THE MODELS...INCLUDING
THE HIGH RESOLUTION MODELS SUGGEST THIS AREA FOR DEVELOPMENT AND
ONLY DIFFER ON HOW FAR NORTH THE STRONG UPDRAFTS WILL BE. SUSPECT
THAT DEVELOPMENT WILL OCCUR IN NORTHWEST KANSAS TO CENTRAL NEBRASKA
THEN WORK NORTHEAST. WHILE CAPPING WILL NEED TO BE OVERCOME...LIKELY
NEEDING HIGH TEMPERATURES CLOSE TO 95 DEGREES...IF ANYTHING COULD
DEVELOP IT SHOULD QUICKLY BECOME SEVERE. MODELS STILL HINTING AT
SURFACE BASED CAPE VALUES OF 3000 TO 3500 J/KG WITH DEEP LAYER SHEAR
OF ABOUT 30 TO 35 KNOTS. THE SURFACE TO 1 KM SHEAR ALSO SUGGESTED TO
BE AROUND 20 KNOTS SO A TORNADO WOULD BE POSSIBLE. AT THIS TIME
DAKOTA AND DIXON COUNTIES APPEAR TO HAVE THE HIGHEST THREAT FOR
TORNADOES IN THE SIOUX FALLS CWA. THERE HAVE BEEN SOME HINTS THAT
SOME SHOWERS AND THUNDERSTORMS COULD DEVELOP OVER THE FAR WESTERN
CWA AS THE UPPER LEVEL SUPPORTS SWINGS INTO THE AREA BUT WILL NOT
INCLUDE ANY CHANCES YET AS CONFIDENCE IN THAT IS TOO LOW.
THE CHANCE FOR SHOWERS AND THUNDERSTORMS WILL CONTINUE IN THE FAR
SOUTHERN CWA ON SATURDAY AS THE UPPER LEVEL WAVE MOVES THROUGH.
INSTABILITY AND SHEAR MUCH WEAKER ON SATURDAY SO MORE GENERAL
CHANCES WITH NO SEVERE THUNDERSTORMS EXPECTED.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 325 PM CDT FRI JUN 14 2013
PRECIP CHANCES ACROSS NORTHWEST IOWA APPEAR TO WANE FAIRLY RAPIDLY
SATURDAY EVENING WITH SURFACE BOUNDARY AND CONVECTION EXPECTED TO
FOCUS ALONG AND SOUTH OF I-80. SURFACE RIDGE NOSES INTO THE
REGION...RESULTING IN GOOD RADIATIVE CONDITIONS.
SURFACE RIDGE BEGINS TO DRIFT TO THE SOUTH AND EAST ON SUNDAY WITH
INSTABILITY ALOFT STARTING TO CREEP INTO SOUTH CENTRAL SOUTH
DAKOTA. INSTABILITY APPEARS TO BE FAIRLY CAPPED WITH WARM LAYER
NEAR 700 MB. WHILE ELEVATED INSTABILITY CREEPS NORTHWARD THROUGHOUT
THE DAY...CAP ONLY WEAKENS SUBSTANTIALLY ENOUGH ALONG THE MISSOURI
RIVER VALLEY WITH LACK OF STRONG UPPER LEVEL SUPPORT. MAY GET A
LITTLE SUPPORT FROM RIGHT REAR QUADRANT OF STRENGTHENING JET
STREAK...BUT STILL MAY BE DIFFICULT TO OVER COME 60-100 J/KG OF
ELEVATED CIN. AS SUCH...LEFT SLIGHT CHANCE/LOW CHANCE POPS
THROUGHOUT THE DAY BUT AM EXPECTING THE FOCUS TO BE SOUTH OF THE
FORECAST AREA.
AS COLD FRONT WORKS THROUGH THE AREA SUNDAY NIGHT HAVE SLIGHT
CHANCE/LOW END CHANCE POPS MAINLY ACROSS NORTHWEST IOWA AND ADJACENT
AREAS. STILL NOT A TON OF INSTABILITY TO WORK WITH...SO IF ANYTHING
DEVELOPS EXPECTING MAINLY GENERAL THUNDERSTORMS WITH JUST AN
ISOLATED THREAT OF SEVERE WEATHER AT BEST.
SURFACE RIDGE BUILDS BACK INTO THE AREA MONDAY INTO TUESDAY CREATING
RELATIVELY QUIET BENIGN WEATHER FOR MID JUNE. WINDS APPEAR TO BE
FAIRLY LIGHT WITH DEW POINTS IN THE MID AND UPPER 50S.
THEREAFTER...A SERIES OF SHORTWAVES MOVE ACROSS THE NORTHERN PLAINS
WEDNESDAY AND BEYOND ORIGINATING FROM THE UPPER LOW OVER THE PACIFIC
NORTHWEST. TIMING OF THE WAVES IS DIFFICULT THAT FAR OUT...SO LEFT
POPS SIMILAR TO GUIDANCE WITH FOCUS MORE TOWARDS THE END OF THE
PERIOD.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 553 PM CDT FRI JUN 14 2013
VFR CONDITIONS ARE EXPECTED TO PREVAIL ACROSS MOST OF SOUTHEAST
SOUTH DAKOTA AND SOUTHWEST MINNESOTA THIS EVENING. THE EXCEPTIONS
ARE AREAS ACROSS AND NEAR NORTHWEST IOWA AND NORTHEAST
NEBRASKA...WHERE A COUPLE OF INTERSECTING FRONTS WILL BE THE FOCUS
FOR STRONG TO SEVERE THUNDERSTORMS. THE NORTHWARD EXTENT OF THE
THUNDERSTORM COVERAGE IS NOT ENTIRELY CERTAIN AND HAVE INTRODUCED
VCTS TO THE KFSD TAF ACCORDINGLY. THE KSUX TAF SITE COULD SEE SOME
SEVERE THUNDERSTORM ACTIVITY THIS EVENING WITH STRONG
LLWS/GUSTS...ESPECIALLY THROUGH 04/05Z. A FRONT WILL STALL ACROSS
NORTHWEST IOWA TONIGHT...MAKING ADDITIONAL TSRA DEVELOPMENT
POSSIBLE AT KSUX SATURDAY MORNING. THE FRONT SHOULD PUSH SOUTHEAST
OF THE AREA DURING THE LATE AFTERNOON.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...SCHUMACHER
SHORT TERM...08
LONG TERM...
AVIATION...
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1138 PM CDT WED JUN 12 2013
.UPDATE...FOR 06Z AVIATION FORECAST
&&
.AVIATION...
LOOKING AT SATELLITE LOOP CONVECTION ACROSS NORTH CENTRAL
INDIANA/NORTHWEST OHIO STARTING TO LOOK MORE AND MORE LIKE AN MESO
CONVECTIVE SYSTEM. COMPLEX EXPECTED TO MOVE FARTHER INTO OHIO AND
EVENTUALLY INTO WEST VIRGINA AND SOUTHWEST PENNSYLVANIA OVER THE
NEXT SEVERAL HOURS. ELEVATED MIXED LAYER EXTENDS FROM CENTRAL
PLAINS EASTWARD INTO SOUTHERN ILLINOIS AND TENNESSEE WHERE 700
MBAR TEMPS ARE 14 DEGREES. MUCH OF THE MIDDLE MISSISSIPPI AND
TENNESSEE VALLEYS ARE CURRENTLY CAPPED OFF.
AT 04Z SURFACE COOL FRONT EXTENDED FROM A LOW IN EASTERN ILLINOIS
DOWN NORTHWEST OF SAINT LOUIS AND THEN INTO SOUTHEASTERN KANSAS.
LATEST GFS RUN PLACES FRONT DOWN ALONG THE OHIO RIVER AT 12Z AND
DOWN INTO NORTHEASTERN ARKANSAS. SHORT RANGE MODELS HAVE NOT
WANTED TO BRING ANY CONVECTION INTO THE MID STATE BEFORE 12Z AND
THE LATEST RUC RUN CONTINUES THIS TREND. LATEST HIGH RESOLUTION
MODEL (H-TRIPLE-R) SHOWS A SKINNY LINE OF WHAT LOOKS TO BE ONLY
SHOWERS BETWEEN NASHVILLE AND CLARKSVILLE AT 12Z. THINK SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS WILL DEVELOP ALONG THE FRONT
BETWEEN 12Z AND 14Z FROM ABOUT NASHVILLE AND EXTEND NORTHEAST INTO
KENTUCKY. THIS ACTIVITY WILL THEN WORK SOUTHEASTWARD ACROSS
EASTERN AREAS OF THE MID STATE AND ALONG THE PLATEAU WHERE THERES
A BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS DURING THE
AFTERNOON AS LATEST SREF RUN SHOWS. WINDS WILL PICK BEHIND THE
FRONT THURSDAY MORNING AND BECOME GUSTY. ALL IN ALL LOOKING AT VFR
WEATHER FOR THE NEXT 24 HOURS.
BOYD
BOYD
&&
.PREV DISCUSSION... /ISSUED 804 PM CDT WED JUN 12 2013/
UPDATE...
SATELLITE IMAGERY SHOWS SKIES HAVE ALMOST COMPLETELY CLEARED
ACROSS THE FORECAST AREA...WITH SURFACE OBS SHOWING IT REMAINS
QUITE WARM AND HUMID WITH TEMPERATURES IN THE 80S TO AROUND 90 AND
DEWPOINTS IN THE UPPER 60S AND LOW 70S. HAVE BEEN MONITORING
ONGOING CONVECTION ACROSS THE GREAT LAKES AND UPPER MIDWEST...BUT
SO FAR ACTIVITY REMAINS FAIRLY DISCRETE AND NO WELL DEFINED MCS
HAS FORMED. BASED ON THIS AND LATEST MODEL RUNS INCLUDING THE
HRRR...APPEARS QUITE UNLIKELY AN MCS WILL AFFECT OUR CWA
OVERNIGHT WITH ACTIVITY REMAINING WELL OFF TO OUR NORTH AND EAST.
A MORE LIKELY SCENARIO IS FOR AN OUTFLOW BOUNDARY/WEAK COLD FRONT
WITH SOME ISOLATED SHOWERS AND POSSIBLY A THUNDERSTORM OR TWO TO
RUSH OUT OF CURRENT ACTIVITY AND MOVE ACROSS THE NORTHEASTERN HALF
OF THE CWA...MAINLY DURING THE MORNING HOURS ON THURSDAY AFTER
12Z. BASED ON THIS REASONING...WILL ONLY HOLD ON TO A SLIGHT
CHANCE POP OVER NORTHEAST ZONES LATE TONIGHT...WITH HIGHER POPS
OVER THE EASTERN HALF THURSDAY MORNING. ALSO ADJUSTED TEMPS UPWARD
AND MADE OTHER TWEAKS TO SKY COVER AND OTHER GRIDS.
SHAMBURGER
PREV DISCUSSION... /ISSUED 659 PM CDT WED JUN 12 2013/
UPDATE...FOR 00Z AVIATION FORECAST
AVIATION...
KEPT VFR CONDITIONS AT TEMINALS FOR THE NEXT 24 HOURS...HOWEVER
THERE IS A SHORT WAVE DROPPING DOWN FROM THE NORTHWEST LATE
TONIGHT THAT WILL BRING THE POTENTIAL FOR SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS AFTER 10Z IN NORTHWEST MIDDLE TENNESSEE AND
INTO THE NASHVILLE AREA AROUND 12Z AND ON THE PLATEAU ABOUT 14Z.
THE BETTER CHANCE FOR CONVECTION WOULD BE ACROSS NORTHEAST MIDDLE
TENNESSEE AND UPPER CUMBERLAND. A COOL FRONT WILL SWEEP DOWN
THROUGH THE MID STATE DURING THE DAY ON THURSDAY ACCOMPANIED BY A
WIND SHIFT AND GUSTY WESTERLY WINDS.
BOYD
PREV DISCUSSION... /ISSUED 336 PM CDT WED JUN 12 2013/
DISCUSSION...
FORECAST REASONING WILL LEAN TOWARD A CONSENSUS MODEL SOLUTION
COMPROMISE FOR THE FORECAST PERIOD UNLESS OTHERWISE NOTED.
FORECAST QUANDARIES...SHWR/TSTM CHANCES LATE TONIGHT INTO THU...ANY
CHANCES FOR SVR TSTMS LATE TONIGHT INTO THU ERN HALF...OVERALL WX
PATTERN NEXT WEEK...TEMPS.
WITH THE NW UPPER LEVEL FLOW PATTERN ESTABLISHED ACROSS THE MID STATE THRU
SAT...MCS DEVELOPMENTS THAT GENERATE ACROSS THE UPPER MIDWEST AS IT IS
STARTING TO LOOK LIKE IS HAPPENING AS THESE AFTERNOON HRS PROGRESS TODAY
WILL HAVE THE POTENTIAL OF DROPPING SEWD AND POTENTIALLY INFLUENCES OUR WX
HERE ACROSS THE MID STATE LATE TONIGHT AND INTO THU....ESPECIALLY ACROSS
ERN PORTIONS OF THE MID STATE. THIS DEVELOPMENT...SEWD MOVEMENT...AND
CONVECTION STRENGTH WILL NEED TO BE CLOSELY MONITORED AS IT MOVES CLOSER
TO OUR AREA FOR FUTURE ADJUSTMENTS TO OUR SUITE OF FORECAST PRODUCTS FOR
THIS EVENING...BUT DO EXPECT ANY MCS ACTIVITY TO BE GENERALLY WEAKER AS IT
MOVES INTO THESE PORTIONS OF THE MID STATE DURING THIS TIME PERIOD THAN
CONVECTIVE POTENTIAL BEING DEVELOPED THIS AFTERNOON...ALONG WITH NOT THE
BEST EXPECTED OVERALL SUPPORTIVE LOW LEVEL JET DYNAMICS IN PLACE ACROSS OUR
NECK OF THE WOODS TO KEEP ORGANIZED SVR TSTMS POTENTIAL HIGH...BUT THERE WILL
BE ENOUGH INSTABILITY AND MOISTURE SHOULD BE PRESENT TO SUPPORT A CHANCE OF
SHWRS/TSTMS BY THE MORNING HRS ON THU ACROSS THE ERN HALF OF THE MID STATE...
WITH A SLIGHT CHANCE WRN PORTIONS. CONVECTION DEVELOPMENT WILL BE AIDED BY A
TYPICAL SUMMERTIME WEAK SFC FRONTAL PASSAGE AS THE DAY PROGRESSES ON THU ALSO.
SPC`S DAY TWO CONVECTIVE OUTLOOK CONTINUES TO KEEP LOCATIONS JUST W OF AND
ACROSS THE PLATEAU IN A SLIGHT RISK FOR SVR TSTMS...WITH SOME OF THESE TSTMS
HAVING THE POTENTIAL OF PRODUCING DAMAGING WINDS AND LARGE HAIL. THOUGH NO
ORGANIZED FLOODING POTENTIAL IS EXPECTED...WOULD NOT WITH THE AMOUNT OF AVAILABLE
MOISTURE IN PLACE BE SURPRISED FOR SOME LOCATIONS TO EXPERIENCE BRIEF HEAVY
DOWNPOURS RESULTING IN SOME LOCALIZED HEAVY RAINFALL AMOUNTS WITH ANY CONVECTION
THAT DOES DEVELOP. BELIEVE THAT A CHANCE OF SHWRS/TSTMS WILL CONTINUE ACROSS
THE PLATEAU REGION DURING THE AFTERNOON HRS ON THU...WITH DRIER AIR WORKING IN
BEHIND THE SFC FRONTAL PASSAGE TO ALLOW FOR DRY CONDITIONS NW PORTIONS OF THE
MID STATE WITH A SLIGHT CHANCE OF SHWRS/TSTMS ACROSS THE REST OF THE MID STATE
ON THU AFTERNOON. WITH SFC RIDGING DYNAMICS IN PLACE ACROSS THE MID STATE THU
NIGHT THRU FRI NIGHT AND A DRY UPPER LEVEL NWLY FLOW PATTERN EXPECTED...DRY
CONDITIONS WILL PREVAIL THRU FRI NIGHT. AS FOR TEMPS DURING THIS TIME PERIOD...
WILL GO GENERALLY CLOSE TO GFS MOS VALUES ON LOWS FOR TONIGHT...RAISED
OVERNIGHT LOWS BY A FEW DEGREES PLATEAU WITH EXPECTED ADDITIONAL CLOUD
COVERAGE...AND WILL GO CLOSE TO GFS VALUES THRU FRI NIGHT. AS FOR AFTERNOON
HIGH TEMP VALUES...THU SHOULD NOT BE AS WARM AS THIS AFTERNOON VALUES...WITH
TEMPS CLOSER TO SEASONABLE NORMAL VALUES ON THU AND EVEN SLIGHTLY COOLER VALUES
ON FRI AS SFC RIDGING INFLUENCES BUILD INTO THE MID STATE.
AS FOR SAT THRU THE MID PORTION OF NEXT WEEK...AS MENTIONED ALSO IN THIS
MORNING`S AFD AND MODEL CONSENSUS CONTINUES TO ILLUSTRATE...POTENTIAL MCS
DEVELOPMENTS SHOULD REMAIN GENERALLY TO OUR NE AS UPPER LEVEL RIDGING DYNAMICS
CONTINUE TO HOLD...WITH THE UPPER LEVEL RIDGING PATTERN FINALLY BREAKING DOWN
DURING THE LATE SUN-MON TIME FRAME...WITH FLOW BECOMING MORE ZONAL IN NATURE
UNTIL SFC/ALOFT RIDGING INFLUENCES AGAIN BUILD BACK ACROSS THE MID STATE AREA
BY MIDWEEK. ANOTHER SFC FRONTAL PASSAGE IS EXPECTED DURING THE DAY ON TUE ALSO.
SEEMS LIKE MORE CONSENSUS HAS ALSO BEEN REACHED BETWEEN THE LATEST EURO/GFS/DGEX
SOLUTIONS ON THE WEATHER PATTERN FOR THIS PORTION OF THE FORECAST PERIOD THAN
PREVIOUS MODEL RUNS HAVE SUGGESTED. THUS...EXPECT ONLY TO MAKE SOME MINOR TWEEKS
HERE AND THERE TO CURRENT FORECAST GRIDDED VALUES WHICH GENERALLY SHOW ISO/SCT
MAINLY AFTERNOON AND EVENING SHWRS/TSTMS DURING THIS TIME PERIOD. AS FOR
TEMPS...AFTERNOON HIGH TEMPS SHOULD GENERALLY BE IN THE UPPER 80S TO LOWER
90S...MID 80S PLATEAU WITH OVERNIGHT LOWS SPANNING THE 60S...I.E. TEMPS CLOSE
TO OR SLIGHTLY ABOVE SEASONABLE NORMS.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
01
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
150 AM EDT THU JUN 13 2013
.SYNOPSIS...
A STRONG COLD FRONT WILL SWEEP ACROSS THE REGION TODAY BRINGING
STRONG TO SEVERE STORMS INTO THE EVENING. MUCH COOLER AND DRIER
AIR WILL FOLLOW THE FRONT AS HIGH PRESSURE BUILDS IN FROM THE
NORTHWEST ON FRIDAY.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 845 PM EDT WEDNESDAY...
EARLIER STORMS WITH FAINT WAVE THAT CLIPPED THROUGH HAVE MOVED
SOUTH LEAVING THE REGION IN A CONTINUED UNSTABLE ENVIRONMENT PER
EVENING SOUNDINGS BUT WITH MOST FOCUS TO THE NORTH/NW. LATEST HRRR
ATTEMPTS TO REDEVELOP CONVECTION ACROSS THE NW DURING THE NEXT FEW
HOURS AS MIXING DIMINISHES...WHILE MOST OTHER GUIDANCE KEEPS
SHRA/TSRA TO THE NW UNTIL LATE. SINCE NOT SEEING MUCH TRIGGER THIS
FAR SOUTH EARLY ON AND DEEP NW FLOW ALOFT...LEANING MORESO TOWARD
THE DRIER RAP SOLUTION WHICH ONLY CLIPS THE FAR NW OVERNIGHT. THUS
ONLY BOOSTING POPS SLIGHTLY TO HIGHER CHANCE/LOW LIKELYS ACROSS
THE FAR NORTH WITH LITTLE COVERAGE ELSW UNTIL AFTER DAYBREAK.
ELSW SHOULD BE CLEAR TO PC AS DEBRIS CLOUDS ARRIVE LATE AHEAD OF
A DECAYING BAND OF SHRA/TSRA ACROSS WVA EARLY THURSDAY. NOT A LOT
OF CHANGE TO WARM/MUGGY TEMPS OVERNIGHT WITH LOWS UPPER 60S/LOWER
70S.
PREVIOUS DISCUSSION...
THE FOCUS OVERNIGHT INTO TOMORROW WILL BE A FAST MOVING COLD
FRONT. THIS FRONT HAS GOOD DYNAMICS AND MOISTURE TO WORK WITH AND
WILL LIKELY BRING SEVERE WEATHER INTO THE REGION. THE MAIN THREAT
WITH THIS FRONT WILL BE STRAIGHT LINE WINDS. SOME METEOROLOGISTS
ARE COMPARING THIS FRONT TO THE DERECHO OF JUNE 2012. THERE ARE
SEVERAL DIFFERENCES BETWEEN THE TWO.
THE MAIN DIFFERENCE IS THAT THIS FRONT WILL BE ENTERING THE AREA
DURING THE MORNING THEN JUMPING TO A LEE TROUGH IN THE EAST BY
EARLY AFTERNOON. THUNDERSTORMS LIKE TO FEED OFF OF HEAT WHICH IS
LACKING IN THE MORNING. THE FRONT MAY NOT JUMP TO THE LEE TROUGH
UNTIL THE AFTERNOON WHICH WILL ALLOW THE SW VA
PIEDMONT...SOUTHSIDE VA...AND NORTHERN NC PIEDMONT TO WARM INTO
THE LOWER 90S. THIS AREA WILL HAVE THE GREATEST POTENTIALLY FOR
BLACKSBURG CWA TO HAVE SEVERE WEATHER. LAST YEAR`S DERECHO MOVED
INTO A VERY WARM ENVIRONMENT OF 90F TO 105F LATE IN THE
AFTERNOON/EARLY EVENING.
ALSO WITH THIS FRONT...A WEST WIND WILL BE ESTABLISHED EARLY.
SHOWERS AND THUNDERSTORMS WILL MOVING INTO THE MOUNTAINS AND
WILL POSSIBLY FADE TOWARD THE BLUE RIDGE DURING THE MORNING. AS
THE FRONT JUMPS TO THE LEE TROUGH...A LINE OF CONVECTION WILL
REDEVELOP OVER THE PIEDMONT. THIS SYSTEM SHOULD EXIT THE AREA BY
RUSH HOUR TOMORROW EVENING.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
AS OF 230 PM EDT WEDNESDAY...
GOING TO SEE SHOWERS AND STORMS EXITING THE EASTERN CWA BY THURSDAY
EVENING WITH LINGERING SHOWERS ACROSS THE WESTERN SLOPES AS ANOTHER
PIECE OF SHORTWAVE ENERGY FOLLOWS THE MAIN FRONT. THINK THE
SUBSIDENCE BEHIND THE CONVECTION TO WORK IN DRIER AIR AND CLEAR
SKIES OUT BY LATE THURSDAY NIGHT IN MOST OF THE REGION...LINGERING
CLOUDS ACROSS THE WESTERN SLOPES OF SE WV.
THERE IS YET ANOTHER SHORTWAVE PUSHING SOUTHEAST ACROSS THE MTNS
FRIDAY ALTHOUGH MOISTURE APPEARS LIMITED. CANNOT RULE OUT A FEW
SPRINKLES OR LIGHT RAIN SHOWERS IN THE MTNS OF SE WV/ALLEGHANY
HIGHLANDS OF VA.
THE AIRMASS WILL BE DRIER FOR PERIOD OF 48 HOURS WHILE SFC HIGH
BUILDS OVERHEAD BY SATURDAY. TEMPS WILL BE A FEW DEGREES COOLER THAN
NORMAL FRIDAY WITH HIGHS RANGING FROM THE LOWER 70S WEST TO LOWER
80S EAST...FOLLOWED BY LOWS FRIDAY NIGHT FROM AROUND 50 WEST TO MID
50S EAST.
THERE SHOULD BE ENOUGH GRADIENT THU NIGH-FRIDAY FOR SOME BREEZY
CONDITIONS...GUSTS UP TO 25 MPH.
SATURDAY WILL BE DRY AND SEASONAL WITH HIGHS RANGING FROM THE MID TO
UPPER 70S WEST TO LOWER TO MID 80S EAST.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 115 PM EDT WEDNESDAY...
EXPECT ANOTHER ACTIVE PERIOD AT LEAST FOR SUNDAY NIGHT-TUESDAY AS
ANOTHER FRONT MAKES ITS WAY TOWARD AND THROUGH THE AREA.
SUNDAY...LOOKING AT HIGH PRESSURE MOVING OFFSHORE SETTING OUR AREA
UP IN THE RETURN FLOW AND INCREASED HUMIDITY. SUNDAY WILL BE A DAY
OF TYPICAL SHOWER/STORM DEVELOPMENT IN THE MTNS.
AS WE HEAD INTO MONDAY-TUESDAY...FRONTAL SYSTEM MOVES FROM GREAT
LAKES-CENTRAL PLAINS SOUTHEAST INTO THE MID ATLANTIC SOUTHWEST TO
THE LOWER OHIO VALLEY. MODELS SIMILAR OVERALL BUT TIMING INDIVIDUAL
CLUSTERS OF SHORTWAVES WILL BE PROBLEMATIC. STILL LOOKS LIKE AN
ACTIVE PATTERN WHERE 2-3 ROUNDS OF SHOWERS/STORMS WILL MOVE ACROSS.
FRONT APPEARS TO FINALLY INCH SOUTHEAST OF OUR AREA BY WEDNESDAY
WITH DRIER AIR MOVING IN FOR AT LEAST ONE OR TWO DAYS.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 135 AM EDT THURSDAY...
CLUSTERS OF THUNDERSTORMS EXTENDED FROM NORTHERN VIRGINIA INTO
CENTRAL OHIO EARLY THIS MORNING. A LINE OF SEVERE THUNDERSTORMS WAS
JUST REACHING CENTRAL OHIO FROM THE WEST AS OF 1AM. EXPECT A
MAJORITY OF THE SHOWERS AND THUNDERSTORMS TO STAY WEST AND NORTH
OF THE FORECAST AREA THROUGH 6AM...HOWEVER HIGH CLOUDS FROM THE
STORMS WILL FILL IN OVER LWB AND LYH.
SATELLITE PICTURES SHOWED MID AND HIGH CLOUDS DEVELOPING ALONG AND
EAST OF THE SOUTHERN APPALACHIANS EARLY THIS MORNING SO EXPECT A
HIGH CEILING AT KROA/KBCB AND KDAN THROUGH 12Z.
MODELS ARE SIMILAR WITH THE TIMING OF AN ORGANIZED AREA OF
SHOWERS/THUNDERSTORMS. EXPECT THE STORMS TO REACH BLF AND LWB
AROUND 13Z/9AM. WEST WINDS MAY WEAKEN THE SHOWERS AND STORMS OVER
ROA AND BCB BUT THEN LOOK FOR THUNDERSTORMS TO REORGANIZE ALONG OR
EAST OF THE MOUNTAINS THIS AFTERNOON. STRONG WINDS POSSIBLE WITH
THE THUNDERSTORMS...ESPECIALLY AT KDAN AND KLYH AFTER 16Z/NOON.
CONFIDENCE IS HIGH ON THE INTENSITY OF THE STORMS EAST OF THE BLUE
RIDGE THIS AFTERNOON AND ON THE TIMING OF THE COLD FRONT.
ASIDE FROM THE THUNDERSTORMS...WINDS WILL BE GUSTY TODAY BOTH
AHEAD OF AND BEHIND THE COLD FRONT.
HIGH PRESSURE WILL BUILD IN FRIDAY AND SATURDAY RESULTING IN VFR
WEATHER. MAY SEE FOG AT THE TYPICAL LOCATIONS SUNDAY MORNING...
KLWB/KBCB...OTHERWISE VFR. LOW LEVEL SOUTHERLY FLOW RETURNS ON
SUNDAY AHEAD OF ANOTHER FRONT MOVING INTO THE MIDWEST/GREAT
LAKES. THIS WILL LIKELY BRING ISOLATED STORMS TO THE MOUNTAINS
SUNDAY AFTERNOON...WITH BETTER COVERAGE ACROSS THE REGION MONDAY
AHEAD OF THE BOUNDARY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/RCS
NEAR TERM...JH/RCS
SHORT TERM...WP
LONG TERM...WP
AVIATION...AMS
AREA FORECAST DISCUSSION
NWS SPOKANE WA
515 PM PDT Fri Jun 14 2013
.SYNOPSIS...
Scattered showers showers are expected today as temperatures
still remain on the cool side. Drier and much warmer weather can
be expected for the weekend. The next weather system will arrive
by Monday and bring more showery and cool weather for much of the
upcoming work week.
&&
.DISCUSSION...
A quick update for early this evening to reduce POPs a bit across
the Panhandle and northern mountains of eastern WA. Radar trends
show decreasing shower coverage across theses areas and IR
satellite imagery is fairly unimpressive with cloud top temps only
cooling to between -12C and -15C. The HRRR model seems to have a
fairly good handle and does suggest that we will see some showers
continuing across these areas through the evening before dissipating
completely overnight. Expect isolated to scattered coverage before
showers continue to wane into the late evening hours. /SVH
&&
.AVIATION...
00Z TAFS: Isolated to scattered showers will continue across the
northern mountains through this evening and then will dissipate
completely overnight. This will leave a mid level cloud deck over
much of the northern third of the region tonight. Winds are
expected to remain weak through Saturday afternoon with VFR
conditions. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 46 77 54 84 55 82 / 0 0 0 0 20 20
Coeur d`Alene 42 77 48 85 52 82 / 10 0 0 0 10 20
Pullman 39 78 47 85 49 78 / 0 0 0 0 10 20
Lewiston 48 86 54 91 58 88 / 0 0 0 0 10 10
Colville 44 82 50 88 53 86 / 40 0 0 10 20 40
Sandpoint 39 76 44 83 50 83 / 40 0 0 10 10 50
Kellogg 43 73 48 82 52 80 / 20 0 0 0 10 20
Moses Lake 46 85 57 91 60 87 / 0 0 0 0 20 20
Wenatchee 51 86 62 89 62 86 / 0 0 0 10 20 20
Omak 44 83 54 88 55 86 / 10 0 0 20 20 20
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1028 AM PDT Thu Jun 13 2013
.SYNOPSIS...
The rest of the work week will be cooler than normal with the
threat of showers. Today will likely be the most active day for
showers and thunderstorms as an area of low pressure tracks slowly
over the region. Drier and warmer weather can be anticipated by
this weekend...with more unsettled conditions returning early next
week.
&&
.DISCUSSION...
Forecast area on the north side of the jet stream today and
tonight and under the influence of a cool/cold conditionally
unstable trof. This mornings 12Z KOTX sounding shows how this is
just the case as the sounding shows fairly steep lapse rates
approaching 8 deg C/KM aloft coupled with a trop that is squished
down/lowered to near 380mb or so. So for now the bulk of the
dynamics associated with the jet stream along the periphery of the
low will keep convection going (including thunderstorms in various
shape/form...regardless of time of day) while in the center of the
low where we are it is likely to be more surface based type
convective showers with a number of the past and recent HRRR model
runs depicting just such a scenario (surface based orographic
convection) starting after 18Z. Storm motion should be quite
slow...5 mph or less and from all sorts of directions due to the
position of this upper level low almost directly overhead. Minimal
changes expected to be made to the forecast this morning. /Pelatti
&&
.AVIATION...
18Z TAFS: Low pressure in the area with jet stream to the south of
the aviation area will allow for scattered showers and thunderstorm
development from now until sundown...primarily with the best chance
over the northern mountains. Slow movement of these hower and
thunderstorm may allow for locally heavy rainfall. VFR should
prevail but local MVFR ceilings and visibilities are possible near
the more intense showers/thunderstorms. After sundown the next
issue of note would be patchy fog and/or stratus/low cloud
development from about 10Z on to 18Z for locations that get the most
rainfall. /Pelatti
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 67 46 68 47 76 53 / 30 30 10 10 10 10
Coeur d`Alene 66 45 67 44 75 48 / 40 40 30 20 10 10
Pullman 65 42 67 43 77 48 / 20 30 20 10 10 10
Lewiston 71 49 75 49 85 54 / 30 30 10 10 0 0
Colville 71 45 73 45 81 50 / 50 50 40 10 10 10
Sandpoint 65 43 65 41 75 44 / 50 50 50 20 10 10
Kellogg 60 44 63 44 72 51 / 50 50 30 20 10 10
Moses Lake 74 48 77 49 84 57 / 20 20 10 0 0 10
Wenatchee 72 52 75 54 84 61 / 20 10 0 10 0 10
Omak 72 47 75 48 82 53 / 30 20 10 10 10 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS SPOKANE WA
749 AM PDT Thu Jun 13 2013
.SYNOPSIS...
The rest of the work week will be cooler than normal with the
threat of showers. Today will likely be the most active day for
showers and thunderstorms as an area of low pressure tracks slowly
over the region. Drier and warmer weather can be anticipated by
this weekend...with more unsettled conditions returning early next
week.
&&
.DISCUSSION...
Forecast area on the north side of the jet stream today and
tonight and under the influence of a cool/cold conditionally
unstable trof. This mornings 12Z KOTX sounding shows how this is
just the case as the sounding shows fairly steep lapse rates
approaching 8 deg C/KM aloft coupled with a trop that is squished
down/lowered to near 380mb or so. So for now the bulk of the
dynamics associated with the jet stream along the periphery of the
low will keep convection going (including thunderstorms in various
shape/form...regardless of time of day) while in the center of the
low where we are it is likely to be more surface based type
convective showers with a number of the past and recent HRRR model
runs depicting just such a scenario (surface based orographic
convection) starting after 18Z. Storm motion should be quite
slow...5 mph or less and from all sorts of directions due to the
position of this upper level low almost directly overhead. Minimal
changes expected to be made to the forecast this morning. /Pelatti
&&
.AVIATION...
12Z TAFS: An upper low moves over the Inland Northwest today,
before shifting east tonight. This feature and the increasing
instability through the afternoon will bring scattered showers and
a threat of thunderstorms around most TAF sites. Chances will be
best between 18Z-03Z. Primarily VFR conditions are expected but
local MVFR cigs/vis are possible in heavier showers. In addition
some locally breezy conditions are expected, especially later this
afternoon near the Cascades. The threat of showers will wane after
dark tonight and shift eastward. There is some threat of local
stratus or patchy fog developing toward Friday morning, around the
higher Palouse, including near KPUW and possibly as far north as
the KGEG-KCOE corridor. Confidence is low. /J. Cote`
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 67 46 68 47 76 53 / 30 30 10 10 10 10
Coeur d`Alene 66 45 67 44 75 48 / 40 40 30 20 10 10
Pullman 65 42 67 43 77 48 / 20 30 20 10 10 10
Lewiston 71 49 75 49 85 54 / 30 30 10 10 0 0
Colville 71 45 73 45 81 50 / 50 50 40 10 10 10
Sandpoint 65 43 65 41 75 44 / 50 50 50 20 10 10
Kellogg 60 44 63 44 72 51 / 50 50 30 20 10 10
Moses Lake 74 48 77 49 84 57 / 20 20 10 0 0 10
Wenatchee 72 52 75 54 84 61 / 20 10 0 10 0 10
Omak 72 47 75 48 82 53 / 30 20 10 10 10 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
905 PM CDT FRI JUN 14 2013
.UPDATE...
CONVECTION IS INCREASING ACROSS IOWA...SE MN AND NORTHWEST
WISCONSIN WITHIN AN IMPRESSIVE MOISTURE AXIS. THE STRONGEST
ACTIVITY IS ACROSS WESTERN IOWA. 850MB WARM AIR ADVECTION KICKS
IN ACROSS THE FORECAST AREA LATER TONIGHT AS THE LOW LEVEL JET
UPSTREAM BEGINS TO TILT FROM SOUTHERLY TO SOUTHWEST. THE THETA-E
ADVECTION IS IMPRESSIVE.
SOME OF THE CONVECTION UPSTREAM IS EXPECTED TO ROLL INTO THE
WESTERN FORECAST AREA AFTER ABOUT 1-3 AM. IT WILL BE BATTLING SOME
DRIER AIR IN THESE PARTS...PLUS THE LOW LEVEL JET WILL BE
WEAKENING. RIGHT NOW IT APPEARS THE STORMS WITH THE HEAVIEST
RAINFALL WILL BE LIMITED TO THE SOUTHWEST HALF OF THE FORECAST
AREA. SOME SMALL HAIL AND GUSTY WINDS ARE POSSIBLE AS SOUNDINGS
DO SHOW A REASONABLE AMOUNT OF ELEVATED CAPE AND EFFECTIVE SHEAR.
SHEAR VECTORS FOR RIGHT MOVING SUPERCELLS IS ALMOST DUE SOUTH. SO
WOULD EXPECT THE STRONGEST ACTIVITY ACROSS IOWA TO TAKE A TURN
TOWARD THE SOUTH WITH TIME.
THE HRRR MODEL TAKES MOST OF THE IOWA ACTIVITY SOUTH OF WISCONSIN
BY 12Z SAT MORNING. THE NEW NAM AT 00Z SHOWS THIS RIGHT TURNING
BEHAVIOR...BUT STILL CLIPS SOUTHWEST WISCONSIN.
&&
.AVIATION/06Z TAFS/...
THE BEST CHANCE FOR ANY THUNDERSTORMS OVERNIGHT WILL BE IN THE
KMSN AREA AFTER ABOUT 8-9Z SAT...AND THIS WOULD ONLY BE FOR A FEW
HOURS. KMKE/KENW/KUES WILL LIKELY REMAIN DRY THROUGH ABOUT 12Z AS
ANY STORMS PUSHING IN WILL BE BATTLING MUCH DRIER AIR OVER
SOUTHEAST WISCONSIN. ANOTHER ROUND OF STORMS IS POSSIBLE LATER
SATURDAY AFTERNOON AND INTO THE EVENING. GENERALLY EXPECT
CONDITIONS TO BE VFR...BUT COULD DROP TO MVFR FOR A TIME WITH ANY
WIDESPREAD STORMS SAT AFTERNOON AND EVENING.
&&
.PREV DISCUSSION... /ISSUED 329 PM CDT FRI JUN 14 2013/
TONIGHT AND SATURDAY...FORECAST CONFIDENCE IS LOW TO MEDIUM.
HAVE CONCERNS ABOUT 12Z NAM SOLUTION WHICH CARRIES MCS ACROSS SRN
WI AFT MIDNIGHT. NOT DOING A VERY GOOD JOB WITH WEAKENING
CONVECTION OVER SRN IA/NRN MO ATTM. ANY CONVECTIVELY INDUCED MCV
FROM THIS ACTIVITY SHOULD REMAIN SOUTHWEST OF SRN WI THIS EVENING.
MORE CONCERNED ABOUT ACTIVITY UPSTREAM OVER NW IA. MCV FROM THIS
ACTIVITY MAY AFFECT SOUTHWEST WI LATER TONIGHT/EARLY SAT. STILL
EXPECT STRONG PUSH OF LOW LEVEL THETA-E ADVECTION TO AFFECT SRN WI
OVERNIGHT AS PWAT VALUES DOUBLE TO AROUND 1.5 INCHES. SHORT TERM
GUIDANCE IN FAIR AGREEMENT ON PIVOTING WEAKENING LOW LEVEL JET
ACROSS SRN WI LATER TONIGHT...WHICH WL LIKELY CARRY WEAKENING
CONVECTION ACROSS TRI-STATE AREA AND PARTS OF SOUTHWEST WI.
EXPECT SCATTERED TO NUMEROUS CONVECTION TO REFIRE SATURDAY
AFTERNOON AS ENHANCED SYNOPTIC SCALE FORCING MOVES ACROSS SRN WI
IN RESPONSE TO RIGHT ENTRANCE REGION OF UPPER JET. BY THIS
TIME...DEWPTS WL LIKELY BE IN THE MIDDLE 60S RESULTING IN SFC
BASED CAPES OF 1000-2000 J/KG. SHEAR NOT THAT IMPRESSIVE BUT
SHOULD BE ENOUGH TO RESULT IN MULTI-CELLS AND ISOLD
SUPERCELLS...PROVIDED CLOUDS FROM MORNING MCS CLEAR DURING THE
LATE MRNG AND AFTN.
SHORT TERM...SATURDAY NIGHT THROUGH MONDAY...FORECAST CONFIDENCE
IS MEDIUM.
SHORT TERM MODELS SHOW SOME DIFFERENCES WITH QPF PLACEMENT AND
SUBSEQUENT THUNDERSTORM CHANCES SATURDAY NIGHT. THE NAM IS NOW
KEEPING A MAJORITY OF THE QPF JUST SOUTH OF THE AREA SATURDAY
NIGHT. HOWEVER...THE GFS/ECMWF/CANADIAN MODELS ALL BRING A BLOB OF
QPF THROUGH PORTIONS OR MOST OF THE AREA SATURDAY EVENING...THEN
TAPER OFF LATER SATURDAY NIGHT.
THIS IS IN RESPONSE TO 850MB LOW LEVEL JET NOSE POINTING INTO THE
AREA AT 00Z SUNDAY PER ECMWF/CANADIAN...THOUGH NAM/GFS HAVE IT
POINTING FURTHER TO THE EAST. ALL MODELS SHOW RIGHT REAR QUADRANT
OF 250MB JET STREAK PUSHING THROUGH THE AREA DURING SATURDAY
EVENING...WITH THE 500MB VORTICITY MAXIMUM PASSING EAST THROUGH
THE AREA.
AREA FORECAST SOUNDINGS FROM NAM SHOWING MODEST MOISTURE IN THE
LOW LEVELS...WITH THE GFS SOUNDINGS MORE MOIST. ELEVATED CAPES OF
500 TO 900 J/KG WITH DECENT EFFECTIVE LAYER SHEAR ON GFS...LESS SO
ON ADJUSTED NAM SOUNDINGS. SEVERE STORMS WITH POSSIBLE LINEAR MCS
MAY CLIP FAR SOUTHWEST COUNTIES DURING THE EVENING...PER SPC DAY
2 OUTLOOK.
LEANED MORE TOWARD THE GFS/ECMWF/CANADIAN AND KEPT HIGH END CHANCE
TO LIKELY POPS NORTHWEST TO SOUTHEAST DURING THE
EVENING...TAPERING OFF LATER IN THE NIGHT...LINGERING IN THE FAR
SOUTH SUNDAY MORNING. THERE IS STILL SOME UNCERTAINTY HERE WITH
WHERE EXACTLY ANY CONVECTION WILL DEVELOP AND MOVE THROUGH...SO
KEEP UP WITH LATER FORECASTS.
NICE DAY EXPECTED SUNDAY...WITH DRIER AIR WORKING INTO THE AREA.
HIGHS SHOULD REACH INTO THE 80S ACROSS MOST OF THE AREA. LAKE
BREEZE LATE IN THE DAY WILL BRING COOLER TEMPERATURES THERE.
NEXT SYSTEM MOVES SOUTHEAST INTO THE REGION SUNDAY NIGHT INTO
MONDAY. SURFACE COLD FRONT SLIDES SOUTHEAST INTO THE AREA BY 00Z
TUESDAY...WITH A STRONG 500MB SHORTWAVE TROUGH. AREA FORECAST
SOUNDINGS SHOWING 500 TO 1000 J/KG MEAN LAYER CAPES WITH MODEST
DEEP LAYER SHEAR.
SLIGHT CHANCE POPS SUNDAY NIGHT IN THE WEST WERE ADDED...WITH
CHANCE POPS FOR MONDAY. MAY HAVE TO RAISE POPS IN LATER FORECASTS
GIVEN STRONG SHORTWAVE AND UNSTABLE AIRMASS OVER THE AREA. A
SEVERE RISK IS POSSIBLE MONDAY IF BETTER DEEP LAYER SHEAR
DEVELOPS.
LONG TERM...MONDAY NIGHT THROUGH FRIDAY...FORECAST CONFIDENCE IS
MEDIUM.
GFS/ECMWF IN DECENT AGREEMENT WITH FEATURES FOR MONDAY NIGHT
THROUGH THURSDAY ACROSS THE REGION. AFTER SMALL CHANCES FOR
LINGERING SHOWERS MONDAY EVENING...HIGH PRESSURE MOVES THROUGH AND
EAST OF THE REGION TUESDAY THROUGH THURSDAY. THIS SHOULD BRING A
STRETCH OF QUIET WEATHER TO THE AREA. TEMPERATURES SHOULD BE NEAR
SEASONAL NORMALS...WITH ONSHORE WINDS EACH DAY KEEPING LAKESHORE
AREAS SOMEWHAT COOLER.
THESE MODELS THEN DIFFER THURSDAY NIGHT INTO FRIDAY...WITH THE GFS
SHOWING A WARMER SOLUTION WITH WARM AIR ADVECTION
PRECIPITATION...AND THE ECMWF KEEPING THE REGION NORTHEAST OF THE
NEXT LOW PRESSURE SYSTEM IN THE CENTRAL HIGH PLAINS. USED
CONSENSUS BLEND FOR THIS PERIOD WITH TEMPERATURES AND POPS.
AVIATION/00Z TAFS/...
VFR CONDITIONS TO CONTINUE TONIGHT. INCREASING THREAT OF
CONVECTION AFFECTING KMSN AROUND AND AFTER 06Z THROUGH THE EARLY
MORNING. ISOLD CONVECTION MAY HOLD TOGETHER AND AFFECT ERN TAF
SITES EARLY SAT. CIGS MAY FLIRT WITH MVFR FOR A TIME SAT MRNG AS
WELL AS LOW LEVEL MOISTURE INCREASES. BETTER CHANCE FOR MORE
WIDESPREAD CONVECTION LATER SAT AFTN AND EVE.
MARINE...
SOME CONCERN REGARDING FOG POTENTIAL ON SATURDAY INTO SATURDAY
NIGHT IN LIGHTER LOW LEVEL WIND REGIME AND INCREASING SFC DEWPTS
INTO THE 60S. LATEST CLOSEUP SEA SURFACE MODIS IMAGERY SHOWS LAKE
TEMPERATURES REMAIN IN THE UPPER 40S TO MID 50S. OTHERWISE NO
PROLONGED PERIOD OF STRONGER WINDS ANTICIPATED THROUGH THE WEEKEND
BUT WL NEED TO WATCH FOR STRONG CONVECTION...ESPECIALLY IN SRN
ZONES SAT INTO SAT EVE.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...DAVIS
TONIGHT/SATURDAY AND AVIATION/MARINE...MBK
SATURDAY NIGHT THROUGH FRIDAY...WOOD
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
530 PM CDT THU JUN 13 2013
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 315 PM CDT THU JUN 13 2013
SURFACE OBSERVATIONS SHOWED HIGH PRESSURE OVER THE REGION PROVIDING
MOSTLY SUNNY SKIES. WATER VAPOR INDICATED A BROAD UPPER RIDGE
OVER THE CENTRAL CONUS. A TROUGH WAS LOCATED OVER THE PACIFIC
NORTHWEST...SLOWLY PUSHING NORTHEAST.
THE HIGH WILL PROVIDE QUIET WEATHER FOR THE ENTIRE FORECAST AREA
THIS EVENING THROUGH THE OVERNIGHT HOURS. PLAN ON MOSTLY CLEAR SKIES
WITH LOW TEMPERATURES RANGING FROM THE UPPER 40S OVER NORTH CENTRAL
WISCONSIN TO THE LOWER TO MIDDLE 50S ACROSS NORTHEAST IOWA.
CLOUDS WILL BE ON THE INCREASE DURING THE DAY ON FRIDAY AS THE RIDGE
BREAKS DOWN AND THE TROUGH LIFTS NORTH THROUGH MONTANA AND INTO
SOUTHERN SASKATCHEWAN. MEANWHILE...A WARM FRONT WILL EDGE EAST OUT
OF THE NORTHERN PLAINS INTO THE UPPER MISSISSIPPI RIVER VALLEY. 850
MB MOISTURE TRANSPORT INCREASES ACROSS WESTERN IOWA/SOUTHERN
MINNESOTA LATE FRIDAY AFTERNOON. ONGOING SHOWERS AND THUNDERSTORMS
OVER EASTERN SOUTH DAKOTA SHOULD TRACK EAST WITH ADDITIONAL
DEVELOPMENT FURTHER EAST AS THE MOISTURE TRANSPORT RAMPS UP LATE
FRIDAY AFTERNOON INTO FRIDAY EVENING. HIGH TEMPERATURES ON FRIDAY
ARE EXPECTED TO RANGE FROM THE LOWER TO MID 70S OVER NORTH CENTRAL
WISCONSIN TO THE UPPER 70S ACROSS NORTHEAST IOWA.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 315 PM CDT THU JUN 13 2013
SHOWERS AND THUNDERSTORMS WILL SPREAD FROM WEST TO EAST ACROSS THE
FORECAST AREA FRIDAY EVENING. THE STRONGEST 850 MB MOISTURE
TRANSPORT IS FOCUSED INTO NORTH CENTRAL/NORTHEAST IOWA. THIS ALSO IS
THE AREA OF THE HIGHEST INSTABILITY WITH 0-3 KM MUCAPE VALUES OF
AROUND 2000 J/KG. ALSO. SURFACE LOW PRESSURE DEVELOPS OVER WESTERN
IOWA WITH A WARM FRONT EXTENDING EAST ACROSS NORTHERN IOWA.
DEPENDING ON EXACTLY WHERE THE WARM FRONT SETS UP...REPEATED ROUNDS
OF SHOWERS AND STORMS FRIDAY NIGHT THROUGH SATURDAY MORNING COULD
LEAD TO FLOODING CONCERN ACROSS NORTHEAST IOWA...PORTIONS OF
SOUTHEAST MINNESOTA...AND POSSIBLY INTO FAR SOUTHWEST WISCONSIN.
THIS RAIN ON TOP OF THE SATURATED SOILS WOULD GO DIRECTLY INTO
RUNOFF...SO WILL HAVE TO KEEP A VERY CLOSE EYE ON THIS. A FLASH
FLOOD WATCH MAY BE NEEDED ONCE CONFIDENCE INCREASES ON EXACTLY
WHERE THE WARM FRONT WILL SET UP.
THERE ARE SUGGESTIONS THAT THE WARM FRONT COULD SET UP CLOSER TO
THE INTERSTATE 80 CORRIDOR. THERE IS THE POTENTIAL FOR A FEW
STORMS CAPABLE OF PRODUCING LARGE HAIL AND DAMAGING WINDS...WITH
1-7 KM BULK SHEAR VALUES OF 30 TO 40 KTS EARLY FRIDAY NIGHT...THEN
THE SHEAR STARTS TO WANE LATE IN THE NIGHT. FORECAST SOUNDINGS
SHOW CAPE VALUES OF 1500 TO 2000 J/KG WHEN LIFTING FROM 875 MB.
THESE HIGHER CAPE VALUES OCCUR MAINLY LATE FRIDAY NIGHT INTO EARLY
SATURDAY MORNING. ADDITIONAL SHOWER AND THUNDERSTORM ACTIVITY IS
EXPECTED ON SATURDAY AS FLOW ALOFT TURNS ZONAL AND ANOTHER
SHORTWAVE MOVES ACROSS SOUTHERN MINNESOTA/NORTHERN IOWA...THEN
PUSHES EAST INTO WESTERN WISCONSIN BY SATURDAY AFTERNOON. THERE
REALLY ISN/T APPRECIABLE FORCING WITH THE WAVE MOVING THROUGH ON
SATURDAY. HOWEVER...THERE APPEARS TO BE ENOUGH INSTABILITY TO
OVERCOME THE LACK OF STRONG FORCING...WITH 0-3 KM MUCAPE VALUES
CLIMBING TO AROUND 2500 J/KG. AN INTERESTING SHEAR PROFILE ACROSS
THE AREA ON SATURDAY...WITH RATHER WEAK FLOW FROM THE SURFACE
THROUGH 700MB. THE WINDS THEN INCREASE FROM ABOVE 700 THROUGH 200
MB...ESPECIALLY LATE SATURDAY AFTERNOON INTO SATURDAY EVENING.
CANNOT RULE OUT A FEW STRONG TO SEVERE STORMS AGAIN ON SATURDAY
WITH LARGE HAIL AND HEAVY RAINFALL THE MAINS CONCERNS.
ZONAL FLOW WILL BE IN PLACE ACROSS THE REGION FROM
SATURDAY NIGHT INTO SUNDAY AS THE TROUGH DIVES SOUTHEAST OUT OF
SOUTHERN MANITOBA AND PUSHES INTO THE FORECAST AREA LATE SUNDAY
AFTERNOON INTO SUNDAY NIGHT. AFTERNOON 0-3 KM MUCAPE VALUES SOAR
TO AROUND 3000 J/KG WITH 0-6 KM BULK SHEAR VALUES HOVERING IN THE
40 TO 45 KT RANGE. STRONG TO SEVERE STORMS APPEAR POSSIBLE SUNDAY
AFTERNOON INTO SUNDAY EVENING. HOWEVER...LATEST GUIDANCE SUGGEST
THE WAVE COULD MOVE IN LATER IN THE EVENING WHICH WOULD LIMIT THE
SEVERE THREAT. THE WAVE MOVES THROUGH THE REGION LATE SUNDAY NIGHT
THROUGH INTO MONDAY MORNING...THEN FINALLY PUSHES INTO THE EASTERN
GREAT LAKES MONDAY NIGHT INTO TUESDAY. HIGH PRESSURE THEN BUILDS
INTO THE UPPER MISSISSIPPI RIVER VALLEY ON WEDNESDAY AND LOOKS TO
LINGER OVER THE REGION THROUGH THURSDAY...WITH HIGHS IN THE MID
70S TO AROUND 80 AND LOWS MAINLY IN THE 50S TO AROUND 60. GUIDANCE
SUGGEST A FEW WEAK DISTURBANCES COULD PUSH THROUGH THE RIDGE
BRINGING SLIGHT CHANCES FOR SHOWERS AND THUNDERSTORMS WEDNESDAY
NIGHT INTO THURSDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 530 PM CDT THU JUN 13 2013
HIGH PRESSURE BUILDS ACROSS THE REGION TONIGHT...WITH SKC SKIES AND
VRB TO LIGHT EAST WINDS. HIGH CLOUDS WILL BE ON THE INCREASE FRI
AFTERNOON...AHEAD OF AN ANTICIPATED AREA OF SHRA/TS MOVING NORTHEAST
AHEAD OF A WARM FRONT. PCPN LOOKS LIKELY FOR KRST/KLSE FRIDAY NIGHT
INTO SATURDAY...WITH A LOWERING IN CIG HEIGHTS AS THE SHRA/TS MOVE
IN. PERIODS OF MVFR APPEARS LIKELY AT THIS TIME...WITH SOME
RESTRICTIONS IN VSBY. PARAMETERS SUGGEST THAT THE SHOWERS AND STORMS
COULD BE EFFICIENT RAIN PRODUCERS...AND HEAVY RAIN WILL BE POSSIBLE.
WINDS WILL INCREASE AND TURN FROM EAST TO SOUTHEAST ON FRIDAY.
TURNING BACK TO TONIGHT...SOME THOUGHTS ABOUT FOG OR POSSIBLY
STRATUS DEVELOPMENT WITH DECOUPLING OF WINDS AND A RELATIVELY WET
BOUNDARY LAYER. HOWEVER...SFC T/TD SPREAD IS 25 DEGREES AT KLSE AS
OF 22Z...AND RAP BUFKIT SOUNDINGS KEEP WINDS STIRRED TO 14 KTS AT
200 FT. SO...THINK THE FOG/STRATUS THREAT WILL BE MINIMAL TONIGHT.
&&
.HYDROLOGY...FRIDAY NIGHT THROUGH SATURDAY
ISSUED AT 315 PM CDT THU JUN 13 2013
FRIDAY NIGHT THROUGH SATURDAY HOLDS THE POTENTIAL TO BRING
PERIODS OF HEAVY RAINFALL TO NORTHEAST IOWA...WHICH COULD QUICKLY
LEAD TO FLASH FLOODING SINCE THE SOILS ACROSS PORTIONS OF
NORTHEAST IOWA ARE ALREADY SATURATED FROM RECENT RAINS.
ALSO...PORTIONS OF SOUTHEAST MINNESOTA AND FAR SOUTHWEST WISCONSIN
COULD BE IMPACTED DEPENDING ON WHERE A FRONTAL BOUNDARY SETS UP
FRIDAY NIGHT. A FEW ROUNDS OF THUNDERSTORMS ARE EXPECTED FROM
FRIDAY NIGHT THROUGH SATURDAY. WITH WARM CLOUD DEPTHS OF 4.2KM AND
PRECIPITABLE WATER VALUES OF 1.5 TO 2 INCHES...THE STORMS WILL BE
EFFICIENT RAIN PRODUCERS. THE AREA THAT LOOKS MOST SUSCEPTIBLE WILL
BE ACROSS PORTIONS OF NORTHEAST IOWA INTO FAR SOUTHWEST WISCONSIN.
THESE AREAS WERE HIT PRETTY HARD ON WEDNESDAY WITH RAINFALL
AMOUNTS RANGING FROM 1 TO 4 INCHES.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM....WETENKAMP
LONG TERM.....WETENKAMP
AVIATION......RIECK
HYDROLOGY.....WETENKAMP
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 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
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 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 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
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 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 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
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
NWS LA CROSSE WI
309 AM 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...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1100 PM CDT FRI JUN 14 2013
CONVECTIVE COMPLEXES WERE ROLLING ACROSS IA WITH THE AID OF THE LOW
LEVEL JET...AND ONE WILL TRACK ACROSS THE TAF SITES FOR THE
OVERNIGHT HOURS. CIGS WILL DROP QUICKLY WITH THE ONSET OF THE
SHRA/TS...ALTHOUGH IT MAY TAKE A FEW HOURS TO FALL INTO THE MVFR
CATEGORY. EXPECT THE LOW CIGS TO HANG AROUND FOR THE BETTER PART OF
THE MORNING...WITH SOME IMPROVEMENT BY AFTERNOON.
AS FOR THE SHRA/TS...EXPECTING A BREAK FROM THE PCPN LATER SATURDAY
MORNING. CHANCES LOOK LIKE THEY WILL INCREASE FOR THE AFTERNOON AS
MODELS SUGGEST AN UPPER LEVEL SHORTWAVE WILL TRACK IN FROM THE
SOUTHWEST...INTERACTING WITH THE WARM FRONT THAT WILL STILL BE
WAVERING WEST-SOUTH ACROSS IOWA. THESE SHRA/TS SHOULD EXIT EARLY SAT
EVENING AS THE SHORTWAVE DEPARTS...WITH A CLEARING CLOUD TREND FOR
THE REST OF THE NIGHT.
&&
.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......RIECK
HYDROLOGY...AJ
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 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 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 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...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 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 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 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 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 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:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
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:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
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 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 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 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 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...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 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 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 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