Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 06/30/12
AREA FORECAST DISCUSSION
NWS LINCOLN IL
855 PM CDT FRI JUN 29 2012
.DISCUSSION...
ISSUED 855 PM CDT FRI JUN 29 2012
STORMS JUST TO THE W AND N OF OUR NORTHERN COUNTIES HAS DIMINISHED
IN INTENSITY OVER THE LAST HOUR. THE SOUTHERN FLANK OF A LINE OF
STORMS IS POISED TO MOVE EAST ACROSS KNOX/STARK/MARSHALL
COUNTIES...AND POSSIBLY FAR NORTHERN PEORIA/NORTHERN WOODFORD
COUNTIES AS WELL. WE CURRENTLY HAVE CHANCE POPS IN PLACE ACROSS
THOSE AREAS. HOWEVER...WE EXPECT TO BUMP UP TO LIKELY POPS FOR N
KNOX/STARK/MARSHALL AND LEAVE CHANCE TO THE SOUTH.
00Z ILX SOUNDING SHOWS 3200 J/KG MLCAPE AVAIL ABOVE THE WARM
CAPPING INVERSION...HOWEVER WITH SUBSTANTIAL DRY AIR ALOFT AS
WELL. THE INVERSION WILL LIKELY BEGIN TO INCREASE WITH DIURNAL
SURFACE COOLING. THE OUTFLOW BOUNDARY THAT MOVED SOUTH TO NEAR
SPI/ILX LATE THIS AFTERNOON HAS REBOUNDED QUICKLY TO THE NORTH
WITH THE RE-ESTABLISHMENT OF THE SW FLOW. THAT BOUNDARY...ALONG
WITH THE COLD POOL BOUNDARY FROM THE STORMS TO OUR NORTH THIS
EVENING...MAY HELP BE A FOCUS FOR ADDITIONAL STORM DEVELOPMENT
LATER TONIGHT. SPC HAS INDICATED THEY WILL BE MONITORING OUR
NORTHERN COUNTIES FOR THE POSSIBLE NEED FOR A WATCH LATER
TONIGHT...BUT ACKNOWLEDGE THE CONVECTIVE INHIBITION MAY BE TOO
STRONG TO OVERCOME.
WILL ADJUST POPS AS MENTIONED EARLIER...WITH SMALL ADJUSTMENT
DOWNWARD TO THE OVERNIGHT LOWS BEHIND THE COLD POOL IN THE NORTH.
WINDS WILL BE VARIABLE WITH THE BOUNDARIES ACROSS THE NORTHERN
HALF...WITH SOUTHWEST FLOW IN THE SOUTH. WILL MAKE MINOR
ADJUSTMENTS TO THE WINDS AS WELL.
UPDATED INFO WILL BE AVAILABLE SHORTLY.
SHIMON
&&
.AVIATION...
ISSUED 645 PM CDT FRI JUN 29 2012...FOR THE 00Z TAFS
MAIN CONCERN WILL BE LOCATION AND TIMING OF ANY THUNDERSTORMS THIS
EVENING/OVERNIGHT...AND AGAIN TOMORROW AFTERNOON. PIA AND BMI WILL
HAVE BETTER CHANCES OF SEEING THUNDERSTORMS OR JUST A FEW SHOWERS
TONIGHT...AND AGAIN SATURDAY AFTERNOON. THE STRONGEST STORMS
WOULD MOST LIKELY AFFECT OUR NORTHERN TERMINALS LATE SATURDAY
AFTERNOON AND INTO SAT EVENING. THERE IS ENOUGH UNCERTAINTY IN THE
LOCATION OF THE STORM TRACKS THAT I DECIDED TO NOT INCLUDE ANY
MENTION OF STORMS JUST YET. WILL MONITOR THE EVENING
SHOWERS/STORMS TO THE WEST OF PIA CLOSELY...TO SEE IF THEY HOLD
TOGETHER. THE PREVIOUSLY SEVERE STORMS IN IOWA COLLAPSED QUITE
RAPIDLY IN THE LAST HOUR...SO WE WILL NOT JUMP THE GUN ON WHAT
STORMS MIGHT REACH PIA THIS EVENING.
AFTER THE OUTFLOW BOUNDARY DROPPED SOUTH OF PIA/BMI/CMI THIS
AFTERNOON...SURFACE WINDS HAVE RETURNED TO A SW DIRECTION AGAIN AT
ALL BUT CMI. EVERYONE SHOULD SEE PREVAILING SW WINDS FOR MOST OF
THE NEXT 24 HOURS...EXCEPT FOR NEAR THUNDERSTORMS.
SKY COVERAGE WILL BE PRIMARILY MOSTLY CLEAR...WITH SOME MID AND
HIGH CLOUDS FROM CONVECTIVE DEBRIS AFFECTING PIA/BMI TONIGHT...AND
AGAIN TOMORROW.
SHIMON
&&
.PREV DISCUSSION...
ISSUED 307 PM CDT FRI JUN 29 2012
MAIN CONCERNS CONTINUE TO BE CHANCE OF PCPN AND LOCATION AS MOST
OF THE CWA SITS UNDER A HEAT DOME. OVERALL...MODELS IN GOOD
AGREEMENT WITH LARGE SCALE FEATURES BUT HAVE TROUBLE WITH THE
SMALLER SCALE FEATURES THAT WOULD AFFECT PCPN TIMING AND LOCATION
AS WELL AS HIGH TEMPS THROUGH DURING THE AFTERNOON. SHORT
TERM...HRRR MODEL...LOOKS TO BE DOING QUITE WELL WITH LOCATION OF
SOME OF THESE SMALLER FEATURES AND RESULTING PCPN. SO THROUGH
TONIGHT WE WILL FOLLOW THE HRRR AND THEN SWITCH TO NAM-WRF/ECMWF.
GFS REMAINS TOO WET.
SHORT TERM...TONIGHT THROUGH MONDAY
CONVECTION OUT OVER IOWA WILL BEGIN TO INCREASE LATE THIS
AFTERNOON AND SLOWLY SLIDE EAST INTO NRN IL. SO CHC POPS IN THE
NORTHERN THIRD OF THE CWA LOOKS GOOD FOR THIS EVENING AND INTO
OVERNIGHT. THIS SHOULD HELP TO KEEP THE FRONT ACROSS THE NORTHERN
PART OF THE CWA INTO TOMORROW. SO WILL KEEP CHC POPS IN THE NORTH
FOR TOMORROW. BEST SCIENTIFIC GUESS RIGHT NOW IS FOR THE FRONT TO
REMAIN IN THAT GENERAL AREA THROUGH TOMORROW AND THEN SLOWLY PUSH
NORTH TOMORROW NIGHT AND REMAIN UP THERE THROUGH SUNDAY. SO WILL
KEEP CHC POPS NEAR THE FRONT AND HAVE SLIGHT CHC POPS TO THE SOUTH
OF THE FRONT...REMAINING IN THE EXTREME NORTH PARTS OF THE
CWA...THROUGH MONDAY.
WARM TEMPS WILL CONTINUE THROUGH THE PERIOD WITH WARMEST TEMPS IN
THE SOUTH HALF OF THE CWA. 90S ARE STILL EXPECTED IN THE NORTH BUT
CLOUDS AND PCPN WILL KEEP THEM DOWN A TAD. HIGHEST DEWPOINTS WILL
BE NORTH WITH THE FRONT WITH DRIER AIR DOWN WITH THE WARMEST
TEMPS. THIS COMBINATION OF DEWPOINTS AND TEMPS WILL CONTINUE THE
HEAT INDEX VALUES AROUND 105 THROUGH SUNDAY...ESPECIALLY IN THE
SOUTHERN HALF OF THE CWA. THE NORTHERN AREAS COULD STILL REACH TO
100 FOR HEAT INDEX...BUT WITH THE HIGHER HUMIDITY OPPRESSIVE
CONDITIONS WILL CONTINUE THERE AS WELL. SO SINCE THIS WILL GO
THROUGH SUNDAY AND REACH 4 DAYS...HAVE CANCELLED REPLACED THE
ADVISORY WITH AN EXCESSIVE HEAT WARNING. IF CRITERIA IS NOT BEING
REACHED IN THE NORTH...THEN LATER SHIFTS CANCEL AS THE NEED
ARISES. HEAT INDICES AT NIGHT SHOULD REMAIN ABOVE 75 AS WELL.
COMPROMISED OF GUIDANCE LOOKS BEST AND RAISED TEMPS A LITTLE IN THE
NORTH.
LONG TERM...MONDAY NIGHT THROUGH FRIDAY
RIDGING OVER THE MIDDLE PART OF THE US WILL REMAIN IN PLACE
THROUGH THE WEEK WITH WEAK IMPULSES RIDING ALONG THE NORTHERN EDGE
OF THE RIDGE. PCPN IS POSSIBLE BUT TIMING AND LOCATION IS VERY
DIFFICULT TO PREDICT THIS FAR OUT. SO HAVE OPTED WITH DRY FORECAST
THROUGH FRIDAY UNTIL BETTER SIGNALS SHOW WHEN PCPN WILL BE. TEMPS
SHOULD REMAIN WARM IN THE MIDDLE TO UPPER 90S...WHICH IS WARMER
THAN GUIDANCE.
AUTEN
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
EXCESSIVE HEAT WARNING UNTIL 7 PM CDT SUNDAY FOR ILZ027>031-
036>038-040>057-061>063-066>068-071>073.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
645 PM CDT FRI JUN 29 2012
.DISCUSSION...
ISSUED 307 PM CDT FRI JUN 29 2012
MAIN CONCERNS CONTINUE TO BE CHANCE OF PCPN AND LOCATION AS MOST
OF THE CWA SITS UNDER A HEAT DOME. OVERALL...MODELS IN GOOD
AGREEMENT WITH LARGE SCALE FEATURES BUT HAVE TROUBLE WITH THE
SMALLER SCALE FEATURES THAT WOULD AFFECT PCPN TIMING AND LOCATION
AS WELL AS HIGH TEMPS THROUGH DURING THE AFTERNOON. SHORT
TERM...HRRR MODEL...LOOKS TO BE DOING QUITE WELL WITH LOCATION OF
SOME OF THESE SMALLER FEATURES AND RESULTING PCPN. SO THROUGH
TONIGHT WE WILL FOLLOW THE HRRR AND THEN SWITCH TO NAM-WRF/ECMWF.
GFS REMAINS TOO WET.
SHORT TERM...TONIGHT THROUGH MONDAY
CONVECTION OUT OVER IOWA WILL BEGIN TO INCREASE LATE THIS
AFTERNOON AND SLOWLY SLIDE EAST INTO NRN IL. SO CHC POPS IN THE
NORTHERN THIRD OF THE CWA LOOKS GOOD FOR THIS EVENING AND INTO
OVERNIGHT. THIS SHOULD HELP TO KEEP THE FRONT ACROSS THE NORTHERN
PART OF THE CWA INTO TOMORROW. SO WILL KEEP CHC POPS IN THE NORTH
FOR TOMORROW. BEST SCIENTIFIC GUESS RIGHT NOW IS FOR THE FRONT TO
REMAIN IN THAT GENERAL AREA THROUGH TOMORROW AND THEN SLOWLY PUSH
NORTH TOMORROW NIGHT AND REMAIN UP THERE THROUGH SUNDAY. SO WILL
KEEP CHC POPS NEAR THE FRONT AND HAVE SLIGHT CHC POPS TO THE SOUTH
OF THE FRONT...REMAINING IN THE EXTREME NORTH PARTS OF THE
CWA...THROUGH MONDAY.
WARM TEMPS WILL CONTINUE THROUGH THE PERIOD WITH WARMEST TEMPS IN
THE SOUTH HALF OF THE CWA. 90S ARE STILL EXPECTED IN THE NORTH BUT
CLOUDS AND PCPN WILL KEEP THEM DOWN A TAD. HIGHEST DEWPOINTS WILL
BE NORTH WITH THE FRONT WITH DRIER AIR DOWN WITH THE WARMEST
TEMPS. THIS COMBINATION OF DEWPOINTS AND TEMPS WILL CONTINUE THE
HEAT INDEX VALUES AROUND 105 THROUGH SUNDAY...ESPECIALLY IN THE
SOUTHERN HALF OF THE CWA. THE NORTHERN AREAS COULD STILL REACH TO
100 FOR HEAT INDEX...BUT WITH THE HIGHER HUMIDITY OPPRESSIVE
CONDITIONS WILL CONTINUE THERE AS WELL. SO SINCE THIS WILL GO
THROUGH SUNDAY AND REACH 4 DAYS...HAVE CANCELLED REPLACED THE
ADVISORY WITH AN EXCESSIVE HEAT WARNING. IF CRITERIA IS NOT BEING
REACHED IN THE NORTH...THEN LATER SHIFTS CANCEL AS THE NEED
ARISES. HEAT INDICES AT NIGHT SHOULD REMAIN ABOVE 75 AS WELL.
COMPROMISED OF GUIDANCE LOOKS BEST AND RAISED TEMPS A LITTLE IN THE
NORTH.
LONG TERM...MONDAY NIGHT THROUGH FRIDAY
RIDGING OVER THE MIDDLE PART OF THE US WILL REMAIN IN PLACE
THROUGH THE WEEK WITH WEAK IMPULSES RIDING ALONG THE NORTHERN EDGE
OF THE RIDGE. PCPN IS POSSIBLE BUT TIMING AND LOCATION IS VERY
DIFFICULT TO PREDICT THIS FAR OUT. SO HAVE OPTED WITH DRY FORECAST
THROUGH FRIDAY UNTIL BETTER SIGNALS SHOW WHEN PCPN WILL BE. TEMPS
SHOULD REMAIN WARM IN THE MIDDLE TO UPPER 90S...WHICH IS WARMER
THAN GUIDANCE.
AUTEN
&&
.AVIATION...
ISSUED 645 PM CDT FRI JUN 29 2012...FOR THE 00Z TAFS
MAIN CONCERN WILL BE LOCATION AND TIMING OF ANY THUNDERSTORMS THIS
EVENING/OVERNIGHT...AND AGAIN TOMORROW AFTERNOON. PIA AND BMI WILL
HAVE BETTER CHANCES OF SEEING THUNDERSTORMS OR JUST A FEW SHOWERS
TONIGHT...AND AGAIN SATURDAY AFTERNOON. THE STRONGEST STORMS
WOULD MOST LIKELY AFFECT OUR NORTHERN TERMINALS LATE SATURDAY
AFTERNOON AND INTO SAT EVENING. THERE IS ENOUGH UNCERTAINTY IN THE
LOCATION OF THE STORM TRACKS THAT I DECIDED TO NOT INCLUDE ANY
MENTION OF STORMS JUST YET. WILL MONITOR THE EVENING
SHOWERS/STORMS TO THE WEST OF PIA CLOSELY...TO SEE IF THEY HOLD
TOGETHER. THE PREVIOUSLY SEVERE STORMS IN IOWA COLLAPSED QUITE
RAPIDLY IN THE LAST HOUR...SO WE WILL NOT JUMP THE GUN ON WHAT
STORMS MIGHT REACH PIA THIS EVENING.
AFTER THE OUTFLOW BOUNDARY DROPPED SOUTH OF PIA/BMI/CMI THIS
AFTERNOON...SURFACE WINDS HAVE RETURNED TO A SW DIRECTION AGAIN AT
ALL BUT CMI. EVERYONE SHOULD SEE PREVAILING SW WINDS FOR MOST OF
THE NEXT 24 HOURS...EXCEPT FOR NEAR THUNDERSTORMS.
SKY COVERAGE WILL BE PRIMARILY MOSTLY CLEAR...WITH SOME MID AND
HIGH CLOUDS FROM CONVECTIVE DEBRIS AFFECTING PIA/BMI TONIGHT...AND
AGAIN TOMORROW.
SHIMON
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
EXCESSIVE HEAT WARNING UNTIL 7 PM CDT SUNDAY FOR ILZ027>031-
036>038-040>057-061>063-066>068-071>073.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
303 PM CDT THU JUN 28 2012
.DISCUSSION...
1017 AM CDT
UPDATE FOR TODAY...HAVE REMOVED MENTION OF MORNING ISOLATED TSRA
ACROSS NW PORTION OF FA AS MINOR DISTURBANCE HAS ENCOUNTERED
INCREASINGLY DRY MID LEVELS AT TO MOVED E. IR SAT SHOWS CLOUD
TOPS HAVE WARMED DURING THE EARLY-MID MORNING.
HAVE TWEAKED DOWN MAX TEMPS BY 1 DEG S...AROUND 2 DEG N...AND
ABOUT 3-4 DEG ALONG N LAKESHORE. LEADING SURFACE TROUGH AND WIND
SHIFT LINE RUNS FROM SHEBOYGAN TO DUBUQUE AT 14Z. THE TRUE COOL
FRONT IS A BIT FURTHER BACK TO THE NW...RUNNING FROM THE BAY OF
GREEN BAY TO S OF LACROSSE...WITH SIGNIFICANT SURFACE DEW POINT
POOLING OCCURRING BETWEEN THE LEADING WIND SHIFT AND THE ACTUAL
FRONT.
LATEST MODEL GUIDANCE SHOWS THE WIND SHIFT DROPPING ACROSS THE
NORTHERN TIER OF COUNTIES BY 18Z AND THE CORE OF THE HOT AIR
BEING SUPPRESSED S TO THE SOUTHERN COUNTIES OF THE FA BY 00Z.
EXPECT THIS TO HOLD DOWN TEMPS JUST A BIT FROM EARLIER FORECASTS.
IN ADDITION...FOLLOWING WIND SHIFT TO OUT OF THE NW LOW LEVEL FLOW
APPEARS WEAK ENOUGH FOR THE WINDS TO FLOP OVER TO NE-E OFF OF THE
LAKE WHICH WILL RESULT IN TEMPERATURES COOLING ALONG THE FAR N
SHORE MID AFTERNOON AND FAR S SHORES LATE AFTERNOON.
AXIS OF INSTABILITY PROGGED TO BE BETWEEN THE LEAD TROUGH AND THE
COOL FRONT WHERE DEW POINTS IN THE UPPER 60S AND LOWER 70S TO BE
POOLED. THIS AXIS TO RUN W-E ACROSS THE NORTHERN COUNTIES AT 18Z
AND THE SOUTHERN COUNTIES AT 00Z. SHORT WAVE SEEN IN WATER VAPOR
SAT LOOP WAS MOVING TO THE FAR W END OF THE MN-IA BORDER AT 1345Z.
MODELS GENERALLY SHOW THIS DISTURBANCE TRACKING E ALONG THE MN-IA
BORDER THROUGH MID DAY THEN TURN ESE ACROSS SW WI AND N CENTRAL IL
DURING THE AFTERNOON. BEST CHANCE FOR TS DEVELOPMENT WILL BE WHERE
THE POOLED LOW LEVEL MOISTURE IS IN PLACE AND WHERE THE COOLER MID
LEVEL AIR ASSOCIATED WITH THE SHORT WAVE TROUGH REMOVES THE CAP
BASED AT AROUND 825HPA.
TRS
//PREV DISCUSSION...
527 AM CDT
HAVE UPDATED FORECAST TO INCLUDE SLIGHT CHANCE MENTION OF
SHRA/TSRA FOR PARTS OF NORTH CENTRAL IL THROUGH MID-MORNING.
AREA OF ACCAS HAD DEVELOPED ACROSS PORTIONS OF CENTRAL AND EASTERN
IA EARLY THIS MORNING...IN REGION FAIRLY STRONG LOW-MID LEVEL
THETA-E ADVECTION ASSOCIATED WITH A SHORT WAVE TROUGH MOVING INTO
THE MID/UPPER MS VALLEY. SLATER IA PROFILER PLOT INDICATES WINDS
IN THE 0.5-3.0 KM LAYER HAVE INCREASED TO 50-60 KTS OVER THE PAST
FEW HOURS...WITH HIGH-BASED RADAR RETURNS DEVELOPING WITHIN
SOUTHERN PERIPHERY OF 2000-3000 J/KG MUCAPE AXIS. ASOS/AWOS SITES
ACROSS EASTERN IA REPORTING CLOUD BASES GENERALLY IN THE
9000-15000 FT RANGE...AND CEDAR RAPIDS RECENTLY REPORTED TSRA WITH
CLOUD BASES AT 11000 FT!
09Z RAP GUIDANCE INDICATES A GRADUAL DECREASE IN 850-700 MB
THETA-E ADVECTION OVER NORTHERN IL THROUGH MID-MORNING...WITH
RECENT RUNS OF THE HRRR ALSO INDICATING DECREASING CONVECTIVE
REFLECTIVITY SIGNATURES ACROSS NORTH CENTRAL IL BY THAT TIME. 06Z
WRF-NAM ISENTROPIC PROGS...ON THE 325K SURFACE...ALSO INDICATES
CONDENSATION PRESSURE DEFICITS SOMEWHAT HIGHER THAN CURRENTLY OVER
EASTERN IA. THUS AT THIS TIME HAVE ADDED SOME SLIGHT CHANCE POPS
BASICALLY NORTH OF A STERLING-BELVIDERE LINE THROUGH 16Z OR SO...
AND WILL HOPE THAT DISSIPATION TREND IN GUIDANCE OCCURS.
RATZER
//PREV DISCUSSION...
400 AM CDT
FORECAST CONCERNS REMAIN FOCUSED ON TRIPLE DIGIT HEAT FOR PORTIONS
OF THE FORECAST AREA TODAY...THEN SHIFT TO PERSISTENT BUT OVERALL
LOW PROBABILITIES OF PERIODIC ROUNDS OF THUNDERSTORMS THROUGH THE
WEEKEND AS COLD FRONT WHICH SAGS ACROSS AREA THIS AFTERNOON STALLS
ACROSS THE SOUTHERN CWA OR JUST OFF TO THE SOUTH TONIGHT.
UPPER RIDGE AXIS WAS ANALYZED ACROSS THE MID-MISSISSIPPI VALLEY AND
WESTERN GREAT LAKES REGION PER 00Z RAOB DATA. OVERNIGHT GOES WATER
VAPOR IMAGERY DEPICTS STRONG UPPER TROUGH SPREADING EAST ACROSS
MANITOBA AND WESTERN ONTARIO HOWEVER...WITH HEIGHT FALLS ALREADY
WORKING TO FLATTEN THE UPPER RIDGE ACROSS THE UPPER MIDWEST. THUS
THE UPPER RIDGE IS BEING SQUASHED SOUTHWARD TODAY ACROSS THE LOWER
MISSOURI AND LOWER OHIO VALLEYS AS FLOW BECOMES MORE ZONAL. AS THIS
OCCURS...LOW LEVEL THERMAL RIDGE OF +30-35 C TEMPS IN THE 925-850 MB
LAYER WILL ALSO BE SUPPRESSED SOUTH A BIT ACROSS SOUTHERN CWA AND
CENTRAL IL/IND AS HAS BEEN THE TREND OF GUIDANCE OVER THE PAST FEW
DAYS. THAT/S NOT TO SAY IT WONT BE HOT ACROSS THE WFO LOT CWA TODAY.
LOW LEVEL THERMAL PROGS CONTINUE TO SUPPORT AFTERNOON MAX TEMPS
RANGING FROM THE UPPER 90S NEAR THE IL/WI BORDER...TO THE 100-105
DEGREE RANGE ALONG/SOUTH OF THE I-80 CORRIDOR. CHICAGO MAY
OFFICIALLY HIT 100...THOUGH COMPLICATING FACTORS INCLUDING SLIGHTLY
FASTER COLD FRONTAL TIMING AND SHIFTING OF WINDS OFF OF LAKE
MICHIGAN BEHIND FROPA. THIS WILL LIKELY ALLOW TEMPS TO FALL BACK
INTO THE 80S THROUGH LATE AFTERNOON AT THE LAKE SHORE WHILE AREAS
FARTHER WEST/SOUTH CONTINUE TO BAKE AT NEARLY 100 DEGREES. SURFACE
DEW POINT TEMPS HAVE RISEN INTO THE MID/UPPER 60S ACROSS PARTS OF
WESTERN IL/SOUTHWEST WI AHEAD OF THE FRONT OVERNIGHT...AND DEW POINT
TEMPS WILL CONTINUE TO INCREASE AS LOW LEVEL MOISTURE POOLS WITHIN
THE FRONTAL ZONE TODAY. WHILE GUIDANCE DEW POINTS IN THE 75-80
DEGREE RANGE ARE LIKELY OVER-FORECAST...AFTERNOON DEWS SHOULD RANGE
FROM THE LOW-MID 60S OVER THE FAR SOUTHEAST...TO THE UPPER 60S TO
AROUND 70 ALONG THE IMMEDIATE FRONTAL ZONE. COUPLED WITH THE AIR
TEMPS MENTIONED ABOVE THIS YIELDS PEAK HEAT INDEX VALUES IN THE
105-110 RANGE...SUPPORTING NO CHANGES TO ONGOING HEAT ADVISORY.
COULD BE A LITTLE IFFY RIGHT ALONG THE LAKE MICHIGAN SHORE AS NOTED
ABOVE...THOUGH HAVE NO PLANS TO PULL HEADLINE AS HEAT INDEX VALUES
SHOULD REACH/EXCEED 100 NEARLY ALL LOCATIONS PRIOR TO FROPA/ONSHORE
WINDS THIS AFTERNOON. TEMPS MAY APPROACH CHICAGO RECORD HIGH OF 101
DEGREES...THOUGH ROCKFORDS 103 IS PROBABLY SAFE TODAY.
AS NOTED ABOVE...FRONT SAGS ACROSS CWA TODAY WITH LOW LEVEL MOISTURE
POOLING DEW POINT TEMPS NEAR 70 DEGREES WITHING THE FRONTAL ZONE.
WHILE SEVERAL MINOR AMPLITUDE SHORT WAVES ARE NOTED LINED UP
INCREASINGLY ZONAL MID/UPPER FLOW...FORECAST SOUNDINGS INDICATE
SUBSTANTIAL CAPPING INITIALLY WHICH ONLY PARTIALLY ERODES THROUGH
THE LATE AFTERNOON HOURS. SIGNIFICANT MLCAPE DOES EXIST IF LOW LEVEL
CONVERGENCE ASSOCIATED WITH FRONTAL BOUNDARY OR COMBINED FRONT AND
LAKE BREEZE BOUNDARY...ON THE ORDER OF 3500-4000 J/KG. THE
INCREASING ZONAL MID-LEVEL FLOW ALSO RESULTS IN 35-40 KTS OF 0-6 KM
BULK SHEAR WHICH WOULD INDICATE THAT IF A STORM IS ABLE TO DEVELOP
AND BREAK THROUGH THE CAP...THE THREAT EXISTS OF SEVERE WEATHER IN
THE FORM OF DAMAGING WINDS AND LARGE HAIL. OF COURSE...THE BIG
QUESTION IS WILL ANYTHING BE ABLE TO BUST THROUGH THE CAP! ODDS ARE
RATHER LOW THIS AFTERNOON INTO THIS EVENING...BUT WILL CONTINUE TO
MENTION A 20 PERCENT ISOLATED TS FOR THE OFF CHANCE THAT ONE
DEVELOPS AND CAUSES SOME PROBLEMS.
FRONT CONTINUES TO SAG ACROSS THE CWA THIS EVENING AND EVENTUALLY
BECOMES NEARLY STATIONARY FROM APPROXIMATELY THE IA/MO BORDER INTO
CENTRAL IL AND THE SOUTHERN CWA BORDER...AND REMAINS THERE MUCH OF
THE WEEKEND. WITH A SERIES OF SEVERAL MINOR AMPLITUDE SHORT WAVE
RIPPLES INDICATED BY GUIDANCE...THE POTENTIAL FOR PERIODIC
OCCASIONAL THUNDERSTORM CLUSTERS IS NOT ZERO. THE MOST LIKELY
SCENARIO AS INDICATED BY SEVERAL GUIDANCE SOLUTIONS IS FOR
DEVELOPMENT OF ELEVATED CONVECTION NORTH OF SURFACE BOUNDARY OVER
PARTS OF EASTERN NEBRASKA/WESTERN IOWA WHERE BETTER BACKED LOW LEVEL
FLOW AND ASSOCIATED MOISTURE CONVERGENCE AND THETA-E ADVECTION WILL
EXIST. STORMS WOULD THE LIKELY PROPAGATE EAST ALONG THE ELEVATED
BAROCLINIC ZONE AND MAY AFFECT THE WFO LOT AREA AT TIMES IN
WEAKENING PHASES. HAVE GENERALLY CARRIED LOW CHANCE POPS FOR
THIS...THOUGH SUSPECT THERE WILL BE MANY DRY HOURS THROUGH THE
WEEKEND IN BETWEEN THESE LITTLE MESOSCALE CLUSTERS OF STORMS.
THOUGH THE FRONT WILL BE SOUTH OF MUCH OF THE CWA...TEMPS IN THE
LOW-MID 90S WILL CONTINUE TO BE THE RULE...THOUGH WEAK FLOW WILL
ALLOW LAKE BREEZES TO COOL TEMPS INTO THE 80S ALONG LAKE MICHIGAN.
RATZER
&&
.CLIMATE...
908 PM CDT
...RECORD OR NEAR RECORD HIGHS POSSIBLE FOR THURSDAY JUNE 28TH...
THE CURRENT FORECAST HIGH IS 100 DEGREES FOR CHICAGO-OHARE AND 99 DEGREES
FOR ROCKFORD ON THURSDAY.
RECORD HIGHS FOR THURSDAY JUNE 28TH:
CHICAGO: 101/1971
ROCKFORD:103/1934
ALL-TIME JUNE RECORD HIGHS:
CHICAGO: 104...6/20/1988.
ROCKFORD: 106...6/1/1934.
ALL-TIME RECORD HIGHS:
CHICAGO: 105...7/24/1934
ROCKFORD: 112...7/14/1936
MDB/JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* LAKE BREEZE TURNING WINDS NORTHEASTERLY.
* POTENTIAL FOR THUNDERSTORMS...WITH GREATEST THREAT BETWEEN
22-00Z ALONG AND JUST BEHIND COLD FRONT. BMD
//DISCUSSION...UPDATED 18Z...
A COLD FRONT IS PUSHING ACROSS NORTHERN ILLINOIS THIS AFTERNOON WITH
WINDS VEERING TO THE NORTHWEST AND TAPERING SOME IN THE FRONTAL
TROUGH. WEAKENING WINDS SHOULD ALLOW A LAKE BREEZE TO DEVELOP AND
PUSH INLAND ACROSS THE CHICAGO AREA THIS AFTERNOON OR EVENING
TURNING WINDS TO THE NORTHEAST...THOUGH TIMING IS STILL SOMEWHAT
UNCERTAIN. THE STRENGTHENING LOW LEVEL CONVERGENCE IN COMBINATION
WITH BROAD SCALE ASCENT ASSOCIATED WITH A SHORTWAVE PUSHING ACROSS
IOWA MAY ALLOW CAPPING INVERSION TO ERODE LEADING TO DEEP CONVECTION
OVER THE AREA. THE BEST WINDOW OF OPPORTUNITY APPEARS TO FALL WITHIN
21-00Z TIMEFRAME OVER THE CHICAGO AREA. GIVEN THE STRENGTH OF THE
CAP THOUGH...THERE IS A GREAT DEAL OF UNCERTAINTY ON THUNDERSTORM
DEVELOPMENT. SHOULD THUNDERSTORMS DEVELOP...COVERAGE SHOULD REMAIN
ISOLATED TO WIDELY SCATTERED MEANING THAT ALL AREAS WILL NOT BE
IMPACTED. GIVEN THE INTENSE INSTABILITY AND 40-50KT SHEAR VALUES...ANY
THUNDERSTORM COULD QUICKLY BECOME SEVERE WITH STRONG WINDS AND LARGE
HAIL POSSIBLE.
LATER TONIGHT...HIGH PRESSURE WILL BEGIN TO BUILD ACROSS THE REGION
WITH WINDS WEAKENING AND BECOMING VARIABLE. NO SIGNIFICANT
WEATHER IS EXPECTED OVERNIGHT. WIND DIRECTION IS A LITTLE
UNCERTAIN EARLY ON FRIDAY AS THE HIGH MOVES EAST ACROSS THE
AREA...BUT SPEEDS SHOULD BE FAIRLY LIGHT. THROUGH THE DAY EXPECT
WINDS TO TREND TO SOUTHERLY THEN SOUTHWEST AND INCREASE AS THE
HIGH MOVES AWAY...EXCEPT IN CHICAGO AREA WHERE A LAKE BREEZE MAY
KEEP WINDS EASTERLY. BMD
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM TO HIGH CONFIDENCE IN WIND DIRECTION TRENDS...MEDIUM
CONFIDENCE ON TIMING OF LAKE BREEZE.
* LOW CONFIDENCE ON THUNDERSTORM EVOLUTION THIS AFTERNOON...TSRA
POSSIBLY DEVELOPING OVERHEAD WITH BEST WINDOW BETWEEN 22-00Z.
* HIGH CONFIDENCE IN VFR CONDITIONS OVERNIGHT.
* LOW TO MEDIUM CONFIDENCE IN WIND DIRECTION FRIDAY MORNING...HIGH
CONFIDENCE IN LIGHT WIND SPEEDS. BMD
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...VFR. SLIGHT CHANCE TSRA.
SATURDAY...VFR. CHANCE TSRA.
SUNDAY...VFR. CHANCE TSRA EARLY.
MONDAY...VFR. SLIGHT CHANCE TSRA.
TUESDAY...VFR. SLIGHT CHANCE TSRA.
WEDNESDAY...VFR. WX NIL.
KREIN
&&
.MARINE...
246 PM CDT
A COLD FRONT MOVING S DOWN FAR SOUTHERN LAKE MI AT MID AFTERNOON
WILL CONTINUE SLOWLY TOWARD THE OHIO VALLEY BEFORE BECOMING
STATIONARY ACROSS CENTRAL IL AND SOUTHERN IN FRI. A MODERATE NW
BREEZE WILL FOLLOW THE COLD FRONT TONIGHT BEFORE BACKING TO THE
SW DURING FRI AS A WEAK RIDGE OF HIGH PRESSURE OVER THE DAKOTAS
AND UPPER MS VALLEY WILL WEAKEN AS IT SPREADS SE ACROSS THE
SOUTHERN LAKES REGION. WINDS WILL BE LIGHT SAT THROUGH MON NIGHT
WITH WEAK HIGH PRESSURE OVER THE WESTERN LAKES REGION. LOW
PRESSURE MOVES NE FROM THE DAKOTAS TO WESTERN ONTARIO MON AND MON
NIGHT THEN E ACROSS ONTARIO TUE AND TUE NIGHT. S TO SW WINDS WILL
INCREASE MODESTLY ON TUE AHEAD OF A COLD FRONT THAT WILL BE
MOVING THROUGH THE UPPER GREAT LAKES REGION LATE TUE NIGHT AND
WED.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...HEAT ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-
ILZ032-ILZ033-ILZ039 UNTIL 8 PM THURSDAY.
IN...HEAT ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 8 PM
THURSDAY.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
247 PM CDT THU JUN 28 2012
.DISCUSSION...
1017 AM CDT
UPDATE FOR TODAY...HAVE REMOVED MENTION OF MORNING ISOLATED TSRA
ACROSS NW PORTION OF FA AS MINOR DISTURBANCE HAS ENCOUNTERED
INCREASINGLY DRY MID LEVELS AT TO MOVED E. IR SAT SHOWS CLOUD
TOPS HAVE WARMED DURING THE EARLY-MID MORNING.
HAVE TWEAKED DOWN MAX TEMPS BY 1 DEG S...AROUND 2 DEG N...AND
ABOUT 3-4 DEG ALONG N LAKESHORE. LEADING SURFACE TROUGH AND WIND
SHIFT LINE RUNS FROM SHEBOYGAN TO DUBUQUE AT 14Z. THE TRUE COOL
FRONT IS A BIT FURTHER BACK TO THE NW...RUNNING FROM THE BAY OF
GREEN BAY TO S OF LACROSSE...WITH SIGNIFICANT SURFACE DEW POINT
POOLING OCCURRING BETWEEN THE LEADING WIND SHIFT AND THE ACTUAL
FRONT.
LATEST MODEL GUIDANCE SHOWS THE WIND SHIFT DROPPING ACROSS THE
NORTHERN TIER OF COUNTIES BY 18Z AND THE CORE OF THE HOT AIR
BEING SUPPRESSED S TO THE SOUTHERN COUNTIES OF THE FA BY 00Z.
EXPECT THIS TO HOLD DOWN TEMPS JUST A BIT FROM EARLIER FORECASTS.
IN ADDITION...FOLLOWING WIND SHIFT TO OUT OF THE NW LOW LEVEL FLOW
APPEARS WEAK ENOUGH FOR THE WINDS TO FLOP OVER TO NE-E OFF OF THE
LAKE WHICH WILL RESULT IN TEMPERATURES COOLING ALONG THE FAR N
SHORE MID AFTERNOON AND FAR S SHORES LATE AFTERNOON.
AXIS OF INSTABILITY PROGGED TO BE BETWEEN THE LEAD TROUGH AND THE
COOL FRONT WHERE DEW POINTS IN THE UPPER 60S AND LOWER 70S TO BE
POOLED. THIS AXIS TO RUN W-E ACROSS THE NORTHERN COUNTIES AT 18Z
AND THE SOUTHERN COUNTIES AT 00Z. SHORT WAVE SEEN IN WATER VAPOR
SAT LOOP WAS MOVING TO THE FAR W END OF THE MN-IA BORDER AT 1345Z.
MODELS GENERALLY SHOW THIS DISTURBANCE TRACKING E ALONG THE MN-IA
BORDER THROUGH MID DAY THEN TURN ESE ACROSS SW WI AND N CENTRAL IL
DURING THE AFTERNOON. BEST CHANCE FOR TS DEVELOPMENT WILL BE WHERE
THE POOLED LOW LEVEL MOISTURE IS IN PLACE AND WHERE THE COOLER MID
LEVEL AIR ASSOCIATED WITH THE SHORT WAVE TROUGH REMOVES THE CAP
BASED AT AROUND 825HPA.
TRS
//PREV DISCUSSION...
527 AM CDT
HAVE UPDATED FORECAST TO INCLUDE SLIGHT CHANCE MENTION OF
SHRA/TSRA FOR PARTS OF NORTH CENTRAL IL THROUGH MID-MORNING.
AREA OF ACCAS HAD DEVELOPED ACROSS PORTIONS OF CENTRAL AND EASTERN
IA EARLY THIS MORNING...IN REGION FAIRLY STRONG LOW-MID LEVEL
THETA-E ADVECTION ASSOCIATED WITH A SHORT WAVE TROUGH MOVING INTO
THE MID/UPPER MS VALLEY. SLATER IA PROFILER PLOT INDICATES WINDS
IN THE 0.5-3.0 KM LAYER HAVE INCREASED TO 50-60 KTS OVER THE PAST
FEW HOURS...WITH HIGH-BASED RADAR RETURNS DEVELOPING WITHIN
SOUTHERN PERIPHERY OF 2000-3000 J/KG MUCAPE AXIS. ASOS/AWOS SITES
ACROSS EASTERN IA REPORTING CLOUD BASES GENERALLY IN THE
9000-15000 FT RANGE...AND CEDAR RAPIDS RECENTLY REPORTED TSRA WITH
CLOUD BASES AT 11000 FT!
09Z RAP GUIDANCE INDICATES A GRADUAL DECREASE IN 850-700 MB
THETA-E ADVECTION OVER NORTHERN IL THROUGH MID-MORNING...WITH
RECENT RUNS OF THE HRRR ALSO INDICATING DECREASING CONVECTIVE
REFLECTIVITY SIGNATURES ACROSS NORTH CENTRAL IL BY THAT TIME. 06Z
WRF-NAM ISENTROPIC PROGS...ON THE 325K SURFACE...ALSO INDICATES
CONDENSATION PRESSURE DEFICITS SOMEWHAT HIGHER THAN CURRENTLY OVER
EASTERN IA. THUS AT THIS TIME HAVE ADDED SOME SLIGHT CHANCE POPS
BASICALLY NORTH OF A STERLING-BELVIDERE LINE THROUGH 16Z OR SO...
AND WILL HOPE THAT DISSIPATION TREND IN GUIDANCE OCCURS.
RATZER
//PREV DISCUSSION...
400 AM CDT
FORECAST CONCERNS REMAIN FOCUSED ON TRIPLE DIGIT HEAT FOR PORTIONS
OF THE FORECAST AREA TODAY...THEN SHIFT TO PERSISTENT BUT OVERALL
LOW PROBABILITIES OF PERIODIC ROUNDS OF THUNDERSTORMS THROUGH THE
WEEKEND AS COLD FRONT WHICH SAGS ACROSS AREA THIS AFTERNOON STALLS
ACROSS THE SOUTHERN CWA OR JUST OFF TO THE SOUTH TONIGHT.
UPPER RIDGE AXIS WAS ANALYZED ACROSS THE MID-MISSISSIPPI VALLEY AND
WESTERN GREAT LAKES REGION PER 00Z RAOB DATA. OVERNIGHT GOES WATER
VAPOR IMAGERY DEPICTS STRONG UPPER TROUGH SPREADING EAST ACROSS
MANITOBA AND WESTERN ONTARIO HOWEVER...WITH HEIGHT FALLS ALREADY
WORKING TO FLATTEN THE UPPER RIDGE ACROSS THE UPPER MIDWEST. THUS
THE UPPER RIDGE IS BEING SQUASHED SOUTHWARD TODAY ACROSS THE LOWER
MISSOURI AND LOWER OHIO VALLEYS AS FLOW BECOMES MORE ZONAL. AS THIS
OCCURS...LOW LEVEL THERMAL RIDGE OF +30-35 C TEMPS IN THE 925-850 MB
LAYER WILL ALSO BE SUPPRESSED SOUTH A BIT ACROSS SOUTHERN CWA AND
CENTRAL IL/IND AS HAS BEEN THE TREND OF GUIDANCE OVER THE PAST FEW
DAYS. THAT/S NOT TO SAY IT WONT BE HOT ACROSS THE WFO LOT CWA TODAY.
LOW LEVEL THERMAL PROGS CONTINUE TO SUPPORT AFTERNOON MAX TEMPS
RANGING FROM THE UPPER 90S NEAR THE IL/WI BORDER...TO THE 100-105
DEGREE RANGE ALONG/SOUTH OF THE I-80 CORRIDOR. CHICAGO MAY
OFFICIALLY HIT 100...THOUGH COMPLICATING FACTORS INCLUDING SLIGHTLY
FASTER COLD FRONTAL TIMING AND SHIFTING OF WINDS OFF OF LAKE
MICHIGAN BEHIND FROPA. THIS WILL LIKELY ALLOW TEMPS TO FALL BACK
INTO THE 80S THROUGH LATE AFTERNOON AT THE LAKE SHORE WHILE AREAS
FARTHER WEST/SOUTH CONTINUE TO BAKE AT NEARLY 100 DEGREES. SURFACE
DEW POINT TEMPS HAVE RISEN INTO THE MID/UPPER 60S ACROSS PARTS OF
WESTERN IL/SOUTHWEST WI AHEAD OF THE FRONT OVERNIGHT...AND DEW POINT
TEMPS WILL CONTINUE TO INCREASE AS LOW LEVEL MOISTURE POOLS WITHIN
THE FRONTAL ZONE TODAY. WHILE GUIDANCE DEW POINTS IN THE 75-80
DEGREE RANGE ARE LIKELY OVER-FORECAST...AFTERNOON DEWS SHOULD RANGE
FROM THE LOW-MID 60S OVER THE FAR SOUTHEAST...TO THE UPPER 60S TO
AROUND 70 ALONG THE IMMEDIATE FRONTAL ZONE. COUPLED WITH THE AIR
TEMPS MENTIONED ABOVE THIS YIELDS PEAK HEAT INDEX VALUES IN THE
105-110 RANGE...SUPPORTING NO CHANGES TO ONGOING HEAT ADVISORY.
COULD BE A LITTLE IFFY RIGHT ALONG THE LAKE MICHIGAN SHORE AS NOTED
ABOVE...THOUGH HAVE NO PLANS TO PULL HEADLINE AS HEAT INDEX VALUES
SHOULD REACH/EXCEED 100 NEARLY ALL LOCATIONS PRIOR TO FROPA/ONSHORE
WINDS THIS AFTERNOON. TEMPS MAY APPROACH CHICAGO RECORD HIGH OF 101
DEGREES...THOUGH ROCKFORDS 103 IS PROBABLY SAFE TODAY.
AS NOTED ABOVE...FRONT SAGS ACROSS CWA TODAY WITH LOW LEVEL MOISTURE
POOLING DEW POINT TEMPS NEAR 70 DEGREES WITHING THE FRONTAL ZONE.
WHILE SEVERAL MINOR AMPLITUDE SHORT WAVES ARE NOTED LINED UP
INCREASINGLY ZONAL MID/UPPER FLOW...FORECAST SOUNDINGS INDICATE
SUBSTANTIAL CAPPING INITIALLY WHICH ONLY PARTIALLY ERODES THROUGH
THE LATE AFTERNOON HOURS. SIGNIFICANT MLCAPE DOES EXIST IF LOW LEVEL
CONVERGENCE ASSOCIATED WITH FRONTAL BOUNDARY OR COMBINED FRONT AND
LAKE BREEZE BOUNDARY...ON THE ORDER OF 3500-4000 J/KG. THE
INCREASING ZONAL MID-LEVEL FLOW ALSO RESULTS IN 35-40 KTS OF 0-6 KM
BULK SHEAR WHICH WOULD INDICATE THAT IF A STORM IS ABLE TO DEVELOP
AND BREAK THROUGH THE CAP...THE THREAT EXISTS OF SEVERE WEATHER IN
THE FORM OF DAMAGING WINDS AND LARGE HAIL. OF COURSE...THE BIG
QUESTION IS WILL ANYTHING BE ABLE TO BUST THROUGH THE CAP! ODDS ARE
RATHER LOW THIS AFTERNOON INTO THIS EVENING...BUT WILL CONTINUE TO
MENTION A 20 PERCENT ISOLATED TS FOR THE OFF CHANCE THAT ONE
DEVELOPS AND CAUSES SOME PROBLEMS.
FRONT CONTINUES TO SAG ACROSS THE CWA THIS EVENING AND EVENTUALLY
BECOMES NEARLY STATIONARY FROM APPROXIMATELY THE IA/MO BORDER INTO
CENTRAL IL AND THE SOUTHERN CWA BORDER...AND REMAINS THERE MUCH OF
THE WEEKEND. WITH A SERIES OF SEVERAL MINOR AMPLITUDE SHORT WAVE
RIPPLES INDICATED BY GUIDANCE...THE POTENTIAL FOR PERIODIC
OCCASIONAL THUNDERSTORM CLUSTERS IS NOT ZERO. THE MOST LIKELY
SCENARIO AS INDICATED BY SEVERAL GUIDANCE SOLUTIONS IS FOR
DEVELOPMENT OF ELEVATED CONVECTION NORTH OF SURFACE BOUNDARY OVER
PARTS OF EASTERN NEBRASKA/WESTERN IOWA WHERE BETTER BACKED LOW LEVEL
FLOW AND ASSOCIATED MOISTURE CONVERGENCE AND THETA-E ADVECTION WILL
EXIST. STORMS WOULD THE LIKELY PROPAGATE EAST ALONG THE ELEVATED
BAROCLINIC ZONE AND MAY AFFECT THE WFO LOT AREA AT TIMES IN
WEAKENING PHASES. HAVE GENERALLY CARRIED LOW CHANCE POPS FOR
THIS...THOUGH SUSPECT THERE WILL BE MANY DRY HOURS THROUGH THE
WEEKEND IN BETWEEN THESE LITTLE MESOSCALE CLUSTERS OF STORMS.
THOUGH THE FRONT WILL BE SOUTH OF MUCH OF THE CWA...TEMPS IN THE
LOW-MID 90S WILL CONTINUE TO BE THE RULE...THOUGH WEAK FLOW WILL
ALLOW LAKE BREEZES TO COOL TEMPS INTO THE 80S ALONG LAKE MICHIGAN.
RATZER
&&
.CLIMATE...
908 PM CDT
...RECORD OR NEAR RECORD HIGHS POSSIBLE FOR THURSDAY JUNE 28TH...
THE CURRENT FORECAST HIGH IS 100 DEGREES FOR CHICAGO-OHARE AND 99 DEGREES
FOR ROCKFORD ON THURSDAY.
RECORD HIGHS FOR THURSDAY JUNE 28TH:
CHICAGO: 101/1971
ROCKFORD:103/1934
ALL-TIME JUNE RECORD HIGHS:
CHICAGO: 104...6/20/1988.
ROCKFORD: 106...6/1/1934.
ALL-TIME RECORD HIGHS:
CHICAGO: 105...7/24/1934
ROCKFORD: 112...7/14/1936
MDB/JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* LAKE BREEZE TURNING WINDS NORTHEASTERLY LATE THIS AFTERNOON OR
THIS EVENING.
* POTENTIAL FOR THUNDERSTORMS...WITH GREATEST THREAT BETWEEN
21-00Z ALONG AND JUST BEHIND COLD FRONT. BMD
//DISCUSSION...UPDATED 18Z...
A COLD FRONT IS PUSHING ACROSS NORTHERN ILLINOIS THIS AFTERNOON WITH
WINDS VEERING TO THE NORTHWEST AND TAPERING SOME IN THE FRONTAL
TROUGH. WEAKENING WINDS SHOULD ALLOW A LAKE BREEZE TO DEVELOP AND
PUSH INLAND ACROSS THE CHICAGO AREA THIS AFTERNOON OR EVENING
TURNING WINDS TO THE NORTHEAST...THOUGH TIMING IS STILL SOMEWHAT
UNCERTAIN. THE STRENGTHENING LOW LEVEL CONVERGENCE IN COMBINATION
WITH BROAD SCALE ASCENT ASSOCIATED WITH A SHORTWAVE PUSHING ACROSS
IOWA MAY ALLOW CAPPING INVERSION TO ERODE LEADING TO DEEP CONVECTION
OVER THE AREA. THE BEST WINDOW OF OPPORTUNITY APPEARS TO FALL WITHIN
21-00Z TIMEFRAME OVER THE CHICAGO AREA. GIVEN THE STRENGTH OF THE
CAP THOUGH...THERE IS A GREAT DEAL OF UNCERTAINTY ON THUNDERSTORM
DEVELOPMENT. SHOULD THUNDERSTORMS DEVELOP...COVERAGE SHOULD REMAIN
ISOLATED TO WIDELY SCATTERED MEANING THAT ALL AREAS WILL NOT BE
IMPACTED. GIVEN THE INTENSE INSTABILITY AND 40-50KT SHEAR VALUES...ANY
THUNDERSTORM COULD QUICKLY BECOME SEVERE WITH STRONG WINDS AND LARGE
HAIL POSSIBLE.
LATER TONIGHT...HIGH PRESSURE WILL BEGIN TO BUILD ACROSS THE REGION
WITH WINDS WEAKENING AND BECOMING VARIABLE. NO SIGNIFICANT
WEATHER IS EXPECTED OVERNIGHT. WIND DIRECTION IS A LITTLE
UNCERTAIN EARLY ON FRIDAY AS THE HIGH MOVES EAST ACROSS THE
AREA...BUT SPEEDS SHOULD BE FAIRLY LIGHT. THROUGH THE DAY EXPECT
WINDS TO TREND TO SOUTHERLY THEN SOUTHWEST AND INCREASE AS THE
HIGH MOVES AWAY...EXCEPT IN CHICAGO AREA WHERE A LAKE BREEZE MAY
KEEP WINDS EASTERLY. BMD
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM TO HIGH CONFIDENCE IN WIND DIRECTION TRENDS...BUT LOW
CONFIDENCE ON SPECIFIC TIMING OF LAKE BREEZE.
* LOW CONFIDENCE ON THUNDERSTORM EVOLUTION THIS AFTERNOON...TSRA
POSSIBLY DEVELOPING OVERHEAD WITH BEST WINDOW BETWEEN 21-00Z.
* HIGH CONFIDENCE IN VFR CONDITIONS OVERNIGHT.
* LOW TO MEDIUM CONFIDENCE IN WIND DIRECTION FRIDAY MORNING...HIGH
CONFIDENCE IN LIGHT WIND SPEEDS. BMD
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...VFR. SLIGHT CHANCE TSRA.
SATURDAY...VFR. CHANCE TSRA.
SUNDAY...VFR. CHANCE TSRA EARLY.
MONDAY...VFR. SLIGHT CHANCE TSRA.
TUESDAY...VFR. SLIGHT CHANCE TSRA.
WEDNESDAY...VFR. WX NIL.
KREIN
&&
.MARINE...
246 PM CDT
A COLD FRONT MOVING S DOWN FAR SOUTHERN LAKE MI AT MID AFTERNOON
WILL CONTINUE SLOWLY TOWARD THE OHIO VALLEY BEFORE BECOMING
STATIONARY ACROSS CENTRAL IL AND SOUTHERN IN FRI. A MODERATE NW
BREEZE WILL FOLLOW THE COLD FRONT TONIGHT BEFORE BACKING TO THE
SW DURING FRI AS A WEAK RIDGE OF HIGH PRESSURE OVER THE DAKOTAS
AND UPPER MS VALLEY WILL WEAKEN AS IT SPREADS SE ACROSS THE
SOUTHERN LAKES REGION. WINDS WILL BE LIGHT SAT THROUGH MON NIGHT
WITH WEAK HIGH PRESSURE OVER THE WESTERN LAKES REGION. LOW
PRESSURE MOVES NE FROM THE DAKOTAS TO WESTERN ONTARIO MON AND MON
NIGHT THEN E ACROSS ONTARIO TUE AND TUE NIGHT. S TO SW WINDS WILL
INCREASE MODESTLY ON TUE AHEAD OF A COLD FRONT THAT WILL BE
MOVING THROUGH THE UPPER GREAT LAKES REGION LATE TUE NIGHT AND
WED.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...HEAT ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-
ILZ032-ILZ033-ILZ039 UNTIL 8 PM THURSDAY.
IN...HEAT ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 8 PM
THURSDAY.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1238 PM CDT THU JUN 28 2012
.DISCUSSION...
1017 AM CDT
UPDATE FOR TODAY...HAVE REMOVED MENTION OF MORNING ISOLATED TSRA
ACROSS NW PORTION OF FA AS MINOR DISTURBANCE HAS ENCOUNTERED
INCREASINGLY DRY MID LEVELS AT TO MOVED E. IR SAT SHOWS CLOUD
TOPS HAVE WARMED DURING THE EARLY-MID MORNING.
HAVE TWEAKED DOWN MAX TEMPS BY 1 DEG S...AROUND 2 DEG N...AND
ABOUT 3-4 DEG ALONG N LAKESHORE. LEADING SURFACE TROUGH AND WIND
SHIFT LINE RUNS FROM SHEBOYGAN TO DUBUQUE AT 14Z. THE TRUE COOL
FRONT IS A BIT FURTHER BACK TO THE NW...RUNNING FROM THE BAY OF
GREEN BAY TO S OF LACROSSE...WITH SIGNIFICANT SURFACE DEW POINT
POOLING OCCURRING BETWEEN THE LEADING WIND SHIFT AND THE ACTUAL
FRONT.
LATEST MODEL GUIDANCE SHOWS THE WIND SHIFT DROPPING ACROSS THE
NORTHERN TIER OF COUNTIES BY 18Z AND THE CORE OF THE HOT AIR
BEING SUPPRESSED S TO THE SOUTHERN COUNTIES OF THE FA BY 00Z.
EXPECT THIS TO HOLD DOWN TEMPS JUST A BIT FROM EARLIER FORECASTS.
IN ADDITION...FOLLOWING WIND SHIFT TO OUT OF THE NW LOW LEVEL FLOW
APPEARS WEAK ENOUGH FOR THE WINDS TO FLOP OVER TO NE-E OFF OF THE
LAKE WHICH WILL RESULT IN TEMPERATURES COOLING ALONG THE FAR N
SHORE MID AFTERNOON AND FAR S SHORES LATE AFTERNOON.
AXIS OF INSTABILITY PROGGED TO BE BETWEEN THE LEAD TROUGH AND THE
COOL FRONT WHERE DEW POINTS IN THE UPPER 60S AND LOWER 70S TO BE
POOLED. THIS AXIS TO RUN W-E ACROSS THE NORTHERN COUNTIES AT 18Z
AND THE SOUTHERN COUNTIES AT 00Z. SHORT WAVE SEEN IN WATER VAPOR
SAT LOOP WAS MOVING TO THE FAR W END OF THE MN-IA BORDER AT 1345Z.
MODELS GENERALLY SHOW THIS DISTURBANCE TRACKING E ALONG THE MN-IA
BORDER THROUGH MID DAY THEN TURN ESE ACROSS SW WI AND N CENTRAL IL
DURING THE AFTERNOON. BEST CHANCE FOR TS DEVELOPMENT WILL BE WHERE
THE POOLED LOW LEVEL MOISTURE IS IN PLACE AND WHERE THE COOLER MID
LEVEL AIR ASSOCIATED WITH THE SHORT WAVE TROUGH REMOVES THE CAP
BASED AT AROUND 825HPA.
TRS
//PREV DISCUSSION...
527 AM CDT
HAVE UPDATED FORECAST TO INCLUDE SLIGHT CHANCE MENTION OF
SHRA/TSRA FOR PARTS OF NORTH CENTRAL IL THROUGH MID-MORNING.
AREA OF ACCAS HAD DEVELOPED ACROSS PORTIONS OF CENTRAL AND EASTERN
IA EARLY THIS MORNING...IN REGION FAIRLY STRONG LOW-MID LEVEL
THETA-E ADVECTION ASSOCIATED WITH A SHORT WAVE TROUGH MOVING INTO
THE MID/UPPER MS VALLEY. SLATER IA PROFILER PLOT INDICATES WINDS
IN THE 0.5-3.0 KM LAYER HAVE INCREASED TO 50-60 KTS OVER THE PAST
FEW HOURS...WITH HIGH-BASED RADAR RETURNS DEVELOPING WITHIN
SOUTHERN PERIPHERY OF 2000-3000 J/KG MUCAPE AXIS. ASOS/AWOS SITES
ACROSS EASTERN IA REPORTING CLOUD BASES GENERALLY IN THE
9000-15000 FT RANGE...AND CEDAR RAPIDS RECENTLY REPORTED TSRA WITH
CLOUD BASES AT 11000 FT!
09Z RAP GUIDANCE INDICATES A GRADUAL DECREASE IN 850-700 MB
THETA-E ADVECTION OVER NORTHERN IL THROUGH MID-MORNING...WITH
RECENT RUNS OF THE HRRR ALSO INDICATING DECREASING CONVECTIVE
REFLECTIVITY SIGNATURES ACROSS NORTH CENTRAL IL BY THAT TIME. 06Z
WRF-NAM ISENTROPIC PROGS...ON THE 325K SURFACE...ALSO INDICATES
CONDENSATION PRESSURE DEFICITS SOMEWHAT HIGHER THAN CURRENTLY OVER
EASTERN IA. THUS AT THIS TIME HAVE ADDED SOME SLIGHT CHANCE POPS
BASICALLY NORTH OF A STERLING-BELVIDERE LINE THROUGH 16Z OR SO...
AND WILL HOPE THAT DISSIPATION TREND IN GUIDANCE OCCURS.
RATZER
//PREV DISCUSSION...
400 AM CDT
FORECAST CONCERNS REMAIN FOCUSED ON TRIPLE DIGIT HEAT FOR PORTIONS
OF THE FORECAST AREA TODAY...THEN SHIFT TO PERSISTENT BUT OVERALL
LOW PROBABILITIES OF PERIODIC ROUNDS OF THUNDERSTORMS THROUGH THE
WEEKEND AS COLD FRONT WHICH SAGS ACROSS AREA THIS AFTERNOON STALLS
ACROSS THE SOUTHERN CWA OR JUST OFF TO THE SOUTH TONIGHT.
UPPER RIDGE AXIS WAS ANALYZED ACROSS THE MID-MISSISSIPPI VALLEY AND
WESTERN GREAT LAKES REGION PER 00Z RAOB DATA. OVERNIGHT GOES WATER
VAPOR IMAGERY DEPICTS STRONG UPPER TROUGH SPREADING EAST ACROSS
MANITOBA AND WESTERN ONTARIO HOWEVER...WITH HEIGHT FALLS ALREADY
WORKING TO FLATTEN THE UPPER RIDGE ACROSS THE UPPER MIDWEST. THUS
THE UPPER RIDGE IS BEING SQUASHED SOUTHWARD TODAY ACROSS THE LOWER
MISSOURI AND LOWER OHIO VALLEYS AS FLOW BECOMES MORE ZONAL. AS THIS
OCCURS...LOW LEVEL THERMAL RIDGE OF +30-35 C TEMPS IN THE 925-850 MB
LAYER WILL ALSO BE SUPPRESSED SOUTH A BIT ACROSS SOUTHERN CWA AND
CENTRAL IL/IND AS HAS BEEN THE TREND OF GUIDANCE OVER THE PAST FEW
DAYS. THAT/S NOT TO SAY IT WONT BE HOT ACROSS THE WFO LOT CWA TODAY.
LOW LEVEL THERMAL PROGS CONTINUE TO SUPPORT AFTERNOON MAX TEMPS
RANGING FROM THE UPPER 90S NEAR THE IL/WI BORDER...TO THE 100-105
DEGREE RANGE ALONG/SOUTH OF THE I-80 CORRIDOR. CHICAGO MAY
OFFICIALLY HIT 100...THOUGH COMPLICATING FACTORS INCLUDING SLIGHTLY
FASTER COLD FRONTAL TIMING AND SHIFTING OF WINDS OFF OF LAKE
MICHIGAN BEHIND FROPA. THIS WILL LIKELY ALLOW TEMPS TO FALL BACK
INTO THE 80S THROUGH LATE AFTERNOON AT THE LAKE SHORE WHILE AREAS
FARTHER WEST/SOUTH CONTINUE TO BAKE AT NEARLY 100 DEGREES. SURFACE
DEW POINT TEMPS HAVE RISEN INTO THE MID/UPPER 60S ACROSS PARTS OF
WESTERN IL/SOUTHWEST WI AHEAD OF THE FRONT OVERNIGHT...AND DEW POINT
TEMPS WILL CONTINUE TO INCREASE AS LOW LEVEL MOISTURE POOLS WITHIN
THE FRONTAL ZONE TODAY. WHILE GUIDANCE DEW POINTS IN THE 75-80
DEGREE RANGE ARE LIKELY OVER-FORECAST...AFTERNOON DEWS SHOULD RANGE
FROM THE LOW-MID 60S OVER THE FAR SOUTHEAST...TO THE UPPER 60S TO
AROUND 70 ALONG THE IMMEDIATE FRONTAL ZONE. COUPLED WITH THE AIR
TEMPS MENTIONED ABOVE THIS YIELDS PEAK HEAT INDEX VALUES IN THE
105-110 RANGE...SUPPORTING NO CHANGES TO ONGOING HEAT ADVISORY.
COULD BE A LITTLE IFFY RIGHT ALONG THE LAKE MICHIGAN SHORE AS NOTED
ABOVE...THOUGH HAVE NO PLANS TO PULL HEADLINE AS HEAT INDEX VALUES
SHOULD REACH/EXCEED 100 NEARLY ALL LOCATIONS PRIOR TO FROPA/ONSHORE
WINDS THIS AFTERNOON. TEMPS MAY APPROACH CHICAGO RECORD HIGH OF 101
DEGREES...THOUGH ROCKFORDS 103 IS PROBABLY SAFE TODAY.
AS NOTED ABOVE...FRONT SAGS ACROSS CWA TODAY WITH LOW LEVEL MOISTURE
POOLING DEW POINT TEMPS NEAR 70 DEGREES WITHING THE FRONTAL ZONE.
WHILE SEVERAL MINOR AMPLITUDE SHORT WAVES ARE NOTED LINED UP
INCREASINGLY ZONAL MID/UPPER FLOW...FORECAST SOUNDINGS INDICATE
SUBSTANTIAL CAPPING INITIALLY WHICH ONLY PARTIALLY ERODES THROUGH
THE LATE AFTERNOON HOURS. SIGNIFICANT MLCAPE DOES EXIST IF LOW LEVEL
CONVERGENCE ASSOCIATED WITH FRONTAL BOUNDARY OR COMBINED FRONT AND
LAKE BREEZE BOUNDARY...ON THE ORDER OF 3500-4000 J/KG. THE
INCREASING ZONAL MID-LEVEL FLOW ALSO RESULTS IN 35-40 KTS OF 0-6 KM
BULK SHEAR WHICH WOULD INDICATE THAT IF A STORM IS ABLE TO DEVELOP
AND BREAK THROUGH THE CAP...THE THREAT EXISTS OF SEVERE WEATHER IN
THE FORM OF DAMAGING WINDS AND LARGE HAIL. OF COURSE...THE BIG
QUESTION IS WILL ANYTHING BE ABLE TO BUST THROUGH THE CAP! ODDS ARE
RATHER LOW THIS AFTERNOON INTO THIS EVENING...BUT WILL CONTINUE TO
MENTION A 20 PERCENT ISOLATED TS FOR THE OFF CHANCE THAT ONE
DEVELOPS AND CAUSES SOME PROBLEMS.
FRONT CONTINUES TO SAG ACROSS THE CWA THIS EVENING AND EVENTUALLY
BECOMES NEARLY STATIONARY FROM APPROXIMATELY THE IA/MO BORDER INTO
CENTRAL IL AND THE SOUTHERN CWA BORDER...AND REMAINS THERE MUCH OF
THE WEEKEND. WITH A SERIES OF SEVERAL MINOR AMPLITUDE SHORT WAVE
RIPPLES INDICATED BY GUIDANCE...THE POTENTIAL FOR PERIODIC
OCCASIONAL THUNDERSTORM CLUSTERS IS NOT ZERO. THE MOST LIKELY
SCENARIO AS INDICATED BY SEVERAL GUIDANCE SOLUTIONS IS FOR
DEVELOPMENT OF ELEVATED CONVECTION NORTH OF SURFACE BOUNDARY OVER
PARTS OF EASTERN NEBRASKA/WESTERN IOWA WHERE BETTER BACKED LOW LEVEL
FLOW AND ASSOCIATED MOISTURE CONVERGENCE AND THETA-E ADVECTION WILL
EXIST. STORMS WOULD THE LIKELY PROPAGATE EAST ALONG THE ELEVATED
BAROCLINIC ZONE AND MAY AFFECT THE WFO LOT AREA AT TIMES IN
WEAKENING PHASES. HAVE GENERALLY CARRIED LOW CHANCE POPS FOR
THIS...THOUGH SUSPECT THERE WILL BE MANY DRY HOURS THROUGH THE
WEEKEND IN BETWEEN THESE LITTLE MESOSCALE CLUSTERS OF STORMS.
THOUGH THE FRONT WILL BE SOUTH OF MUCH OF THE CWA...TEMPS IN THE
LOW-MID 90S WILL CONTINUE TO BE THE RULE...THOUGH WEAK FLOW WILL
ALLOW LAKE BREEZES TO COOL TEMPS INTO THE 80S ALONG LAKE MICHIGAN.
RATZER
&&
.CLIMATE...
908 PM CDT
...RECORD OR NEAR RECORD HIGHS POSSIBLE FOR THURSDAY JUNE 28TH...
THE CURRENT FORECAST HIGH IS 100 DEGREES FOR CHICAGO-OHARE AND 99 DEGREES
FOR ROCKFORD ON THURSDAY.
RECORD HIGHS FOR THURSDAY JUNE 28TH:
CHICAGO: 101/1971
ROCKFORD:103/1934
ALL-TIME JUNE RECORD HIGHS:
CHICAGO: 104...6/20/1988.
ROCKFORD: 106...6/1/1934.
ALL-TIME RECORD HIGHS:
CHICAGO: 105...7/24/1934
ROCKFORD: 112...7/14/1936
MDB/JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* LAKE BREEZE TURNING WINDS NORTHEASTERLY LATE THIS AFTERNOON OR
THIS EVENING.
* POTENTIAL FOR THUNDERSTORMS...WITH GREATEST THREAT BETWEEN
21-00Z ALONG AND JUST BEHIND COLD FRONT. BMD
//DISCUSSION...UPDATED 18Z...
A COLD FRONT IS PUSHING ACROSS NORTHERN ILLINOIS THIS AFTERNOON WITH
WINDS VEERING TO THE NORTHWEST AND TAPERING SOME IN THE FRONTAL
TROUGH. WEAKENING WINDS SHOULD ALLOW A LAKE BREEZE TO DEVELOP AND
PUSH INLAND ACROSS THE CHICAGO AREA THIS AFTERNOON OR EVENING
TURNING WINDS TO THE NORTHEAST...THOUGH TIMING IS STILL SOMEWHAT
UNCERTAIN. THE STRENGTHENING LOW LEVEL CONVERGENCE IN COMBINATION
WITH BROAD SCALE ASCENT ASSOCIATED WITH A SHORTWAVE PUSHING ACROSS
IOWA MAY ALLOW CAPPING INVERSION TO ERODE LEADING TO DEEP CONVECTION
OVER THE AREA. THE BEST WINDOW OF OPPORTUNITY APPEARS TO FALL WITHIN
21-00Z TIMEFRAME OVER THE CHICAGO AREA. GIVEN THE STRENGTH OF THE
CAP THOUGH...THERE IS A GREAT DEAL OF UNCERTAINTY ON THUNDERSTORM
DEVELOPMENT. SHOULD THUNDERSTORMS DEVELOP...COVERAGE SHOULD REMAIN
ISOLATED TO WIDELY SCATTERED MEANING THAT ALL AREAS WILL NOT BE
IMPACTED. GIVEN THE INTENSE INSTABILITY AND 40-50KT SHEAR VALUES...ANY
THUNDERSTORM COULD QUICKLY BECOME SEVERE WITH STRONG WINDS AND LARGE
HAIL POSSIBLE.
LATER TONIGHT...HIGH PRESSURE WILL BEGIN TO BUILD ACROSS THE REGION
WITH WINDS WEAKENING AND BECOMING VARIABLE. NO SIGNIFICANT
WEATHER IS EXPECTED OVERNIGHT. WIND DIRECTION IS A LITTLE
UNCERTAIN EARLY ON FRIDAY AS THE HIGH MOVES EAST ACROSS THE
AREA...BUT SPEEDS SHOULD BE FAIRLY LIGHT. THROUGH THE DAY EXPECT
WINDS TO TREND TO SOUTHERLY THEN SOUTHWEST AND INCREASE AS THE
HIGH MOVES AWAY...EXCEPT IN CHICAGO AREA WHERE A LAKE BREEZE MAY
KEEP WINDS EASTERLY. BMD
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM TO HIGH CONFIDENCE IN WIND DIRECTION TRENDS...BUT LOW
CONFIDENCE ON SPECIFIC TIMING OF LAKE BREEZE.
* LOW CONFIDENCE ON THUNDERSTORM EVOLUTION THIS AFTERNOON...TSRA
POSSIBLY DEVELOPING OVERHEAD WITH BEST WINDOW BETWEEN 21-00Z.
* HIGH CONFIDENCE IN VFR CONDITIONS OVERNIGHT.
* LOW TO MEDIUM CONFIDENCE IN WIND DIRECTION FRIDAY MORNING...HIGH
CONFIDENCE IN LIGHT WIND SPEEDS. BMD
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...VFR. SLIGHT CHANCE TSRA.
SATURDAY...VFR. CHANCE TSRA.
SUNDAY...VFR. CHANCE TSRA EARLY.
MONDAY...VFR. SLIGHT CHANCE TSRA.
TUESDAY...VFR. SLIGHT CHANCE TSRA.
WEDNESDAY...VFR. WX NIL.
KREIN
&&
.MARINE...
310 AM CDT
A LARGE AREA OF HIGH PRESSURE CENTERED OVER THE SOUTHERN
APPALACHIANS WILL CONTINUE TO SLOWLY DRIFT SOUTHEAST TODAY. LOW
PRESSURE WILL MOVE FROM MANITOBA NORTHEASTWARD TO HUDSON BAY
WHILE DRAGGING A COLD FRONT THROUGH THE UPPER MIDWEST AND THE
WESTERN GREAT LAKES REGION. WITH THE FRONT CONTINUING OFF TO THE
EAST THURSDAY NIGHT...A WEAK RIDGE OF HIGH PRESSURE WILL SPREAD
FROM THE NORTHERN PLAINS INTO THE GREAT LAKES. LOW PRESSURE OF
WILL MOVE FROM THE CENTRAL PLAINS INTO THE WESTERN GREAT LAKES
SATURDAY AND SATURDAY NIGHT BEFORE FILLING. ANOTHER COLD FRONT
WILL PUSH SOUTHEAST THROUGH THE UPPER GREAT LAKES SUNDAY NIGHT.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...HEAT ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-
ILZ032-ILZ033-ILZ039 UNTIL 8 PM THURSDAY.
IN...HEAT ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 8 PM
THURSDAY.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1105 AM CDT THU JUN 28 2012
.DISCUSSION...
1017 AM CDT
UPDATE FOR TODAY...HAVE REMOVED MENTION OF MORNING ISOLATED TSRA
ACROSS NW PORTION OF FA AS MINOR DISTURBANCE HAS ENCOUNTERED
INCREASINGLY DRY MID LEVELS AT TO MOVED E. IR SAT SHOWS CLOUD
TOPS HAVE WARMED DURING THE EARLY-MID MORNING.
HAVE TWEAKED DOWN MAX TEMPS BY 1 DEG S...AROUND 2 DEG N...AND
ABOUT 3-4 DEG ALONG N LAKESHORE. LEADING SURFACE TROUGH AND WIND
SHIFT LINE RUNS FROM SHEBOYGAN TO DUBUQUE AT 14Z. THE TRUE COOL
FRONT IS A BIT FURTHER BACK TO THE NW...RUNNING FROM THE BAY OF
GREEN BAY TO S OF LACROSSE...WITH SIGNIFICANT SURFACE DEW POINT
POOLING OCCURRING BETWEEN THE LEADING WIND SHIFT AND THE ACTUAL
FRONT.
LATEST MODEL GUIDANCE SHOWS THE WIND SHIFT DROPPING ACROSS THE
NORTHERN TIER OF COUNTIES BY 18Z AND THE CORE OF THE HOT AIR
BEING SUPPRESSED S TO THE SOUTHERN COUNTIES OF THE FA BY 00Z.
EXPECT THIS TO HOLD DOWN TEMPS JUST A BIT FROM EARLIER FORECASTS.
IN ADDITION...FOLLOWING WIND SHIFT TO OUT OF THE NW LOW LEVEL FLOW
APPEARS WEAK ENOUGH FOR THE WINDS TO FLOP OVER TO NE-E OFF OF THE
LAKE WHICH WILL RESULT IN TEMPERATURES COOLING ALONG THE FAR N
SHORE MID AFTERNOON AND FAR S SHORES LATE AFTERNOON.
AXIS OF INSTABILITY PROGGED TO BE BETWEEN THE LEAD TROUGH AND THE
COOL FRONT WHERE DEW POINTS IN THE UPPER 60S AND LOWER 70S TO BE
POOLED. THIS AXIS TO RUN W-E ACROSS THE NORTHERN COUNTIES AT 18Z
AND THE SOUTHERN COUNTIES AT 00Z. SHORT WAVE SEEN IN WATER VAPOR
SAT LOOP WAS MOVING TO THE FAR W END OF THE MN-IA BORDER AT 1345Z.
MODELS GENERALLY SHOW THIS DISTURBANCE TRACKING E ALONG THE MN-IA
BORDER THROUGH MID DAY THEN TURN ESE ACROSS SW WI AND N CENTRAL IL
DURING THE AFTERNOON. BEST CHANCE FOR TS DEVELOPMENT WILL BE WHERE
THE POOLED LOW LEVEL MOISTURE IS IN PLACE AND WHERE THE COOLER MID
LEVEL AIR ASSOCIATED WITH THE SHORT WAVE TROUGH REMOVES THE CAP
BASED AT AROUND 825HPA.
TRS
//PREV DISCUSSION...
527 AM CDT
HAVE UPDATED FORECAST TO INCLUDE SLIGHT CHANCE MENTION OF
SHRA/TSRA FOR PARTS OF NORTH CENTRAL IL THROUGH MID-MORNING.
AREA OF ACCAS HAD DEVELOPED ACROSS PORTIONS OF CENTRAL AND EASTERN
IA EARLY THIS MORNING...IN REGION FAIRLY STRONG LOW-MID LEVEL
THETA-E ADVECTION ASSOCIATED WITH A SHORT WAVE TROUGH MOVING INTO
THE MID/UPPER MS VALLEY. SLATER IA PROFILER PLOT INDICATES WINDS
IN THE 0.5-3.0 KM LAYER HAVE INCREASED TO 50-60 KTS OVER THE PAST
FEW HOURS...WITH HIGH-BASED RADAR RETURNS DEVELOPING WITHIN
SOUTHERN PERIPHERY OF 2000-3000 J/KG MUCAPE AXIS. ASOS/AWOS SITES
ACROSS EASTERN IA REPORTING CLOUD BASES GENERALLY IN THE
9000-15000 FT RANGE...AND CEDAR RAPIDS RECENTLY REPORTED TSRA WITH
CLOUD BASES AT 11000 FT!
09Z RAP GUIDANCE INDICATES A GRADUAL DECREASE IN 850-700 MB
THETA-E ADVECTION OVER NORTHERN IL THROUGH MID-MORNING...WITH
RECENT RUNS OF THE HRRR ALSO INDICATING DECREASING CONVECTIVE
REFLECTIVITY SIGNATURES ACROSS NORTH CENTRAL IL BY THAT TIME. 06Z
WRF-NAM ISENTROPIC PROGS...ON THE 325K SURFACE...ALSO INDICATES
CONDENSATION PRESSURE DEFICITS SOMEWHAT HIGHER THAN CURRENTLY OVER
EASTERN IA. THUS AT THIS TIME HAVE ADDED SOME SLIGHT CHANCE POPS
BASICALLY NORTH OF A STERLING-BELVIDERE LINE THROUGH 16Z OR SO...
AND WILL HOPE THAT DISSIPATION TREND IN GUIDANCE OCCURS.
RATZER
//PREV DISCUSSION...
400 AM CDT
FORECAST CONCERNS REMAIN FOCUSED ON TRIPLE DIGIT HEAT FOR PORTIONS
OF THE FORECAST AREA TODAY...THEN SHIFT TO PERSISTENT BUT OVERALL
LOW PROBABILITIES OF PERIODIC ROUNDS OF THUNDERSTORMS THROUGH THE
WEEKEND AS COLD FRONT WHICH SAGS ACROSS AREA THIS AFTERNOON STALLS
ACROSS THE SOUTHERN CWA OR JUST OFF TO THE SOUTH TONIGHT.
UPPER RIDGE AXIS WAS ANALYZED ACROSS THE MID-MISSISSIPPI VALLEY AND
WESTERN GREAT LAKES REGION PER 00Z RAOB DATA. OVERNIGHT GOES WATER
VAPOR IMAGERY DEPICTS STRONG UPPER TROUGH SPREADING EAST ACROSS
MANITOBA AND WESTERN ONTARIO HOWEVER...WITH HEIGHT FALLS ALREADY
WORKING TO FLATTEN THE UPPER RIDGE ACROSS THE UPPER MIDWEST. THUS
THE UPPER RIDGE IS BEING SQUASHED SOUTHWARD TODAY ACROSS THE LOWER
MISSOURI AND LOWER OHIO VALLEYS AS FLOW BECOMES MORE ZONAL. AS THIS
OCCURS...LOW LEVEL THERMAL RIDGE OF +30-35 C TEMPS IN THE 925-850 MB
LAYER WILL ALSO BE SUPPRESSED SOUTH A BIT ACROSS SOUTHERN CWA AND
CENTRAL IL/IND AS HAS BEEN THE TREND OF GUIDANCE OVER THE PAST FEW
DAYS. THAT/S NOT TO SAY IT WONT BE HOT ACROSS THE WFO LOT CWA TODAY.
LOW LEVEL THERMAL PROGS CONTINUE TO SUPPORT AFTERNOON MAX TEMPS
RANGING FROM THE UPPER 90S NEAR THE IL/WI BORDER...TO THE 100-105
DEGREE RANGE ALONG/SOUTH OF THE I-80 CORRIDOR. CHICAGO MAY
OFFICIALLY HIT 100...THOUGH COMPLICATING FACTORS INCLUDING SLIGHTLY
FASTER COLD FRONTAL TIMING AND SHIFTING OF WINDS OFF OF LAKE
MICHIGAN BEHIND FROPA. THIS WILL LIKELY ALLOW TEMPS TO FALL BACK
INTO THE 80S THROUGH LATE AFTERNOON AT THE LAKE SHORE WHILE AREAS
FARTHER WEST/SOUTH CONTINUE TO BAKE AT NEARLY 100 DEGREES. SURFACE
DEW POINT TEMPS HAVE RISEN INTO THE MID/UPPER 60S ACROSS PARTS OF
WESTERN IL/SOUTHWEST WI AHEAD OF THE FRONT OVERNIGHT...AND DEW POINT
TEMPS WILL CONTINUE TO INCREASE AS LOW LEVEL MOISTURE POOLS WITHIN
THE FRONTAL ZONE TODAY. WHILE GUIDANCE DEW POINTS IN THE 75-80
DEGREE RANGE ARE LIKELY OVER-FORECAST...AFTERNOON DEWS SHOULD RANGE
FROM THE LOW-MID 60S OVER THE FAR SOUTHEAST...TO THE UPPER 60S TO
AROUND 70 ALONG THE IMMEDIATE FRONTAL ZONE. COUPLED WITH THE AIR
TEMPS MENTIONED ABOVE THIS YIELDS PEAK HEAT INDEX VALUES IN THE
105-110 RANGE...SUPPORTING NO CHANGES TO ONGOING HEAT ADVISORY.
COULD BE A LITTLE IFFY RIGHT ALONG THE LAKE MICHIGAN SHORE AS NOTED
ABOVE...THOUGH HAVE NO PLANS TO PULL HEADLINE AS HEAT INDEX VALUES
SHOULD REACH/EXCEED 100 NEARLY ALL LOCATIONS PRIOR TO FROPA/ONSHORE
WINDS THIS AFTERNOON. TEMPS MAY APPROACH CHICAGO RECORD HIGH OF 101
DEGREES...THOUGH ROCKFORDS 103 IS PROBABLY SAFE TODAY.
AS NOTED ABOVE...FRONT SAGS ACROSS CWA TODAY WITH LOW LEVEL MOISTURE
POOLING DEW POINT TEMPS NEAR 70 DEGREES WITHING THE FRONTAL ZONE.
WHILE SEVERAL MINOR AMPLITUDE SHORT WAVES ARE NOTED LINED UP
INCREASINGLY ZONAL MID/UPPER FLOW...FORECAST SOUNDINGS INDICATE
SUBSTANTIAL CAPPING INITIALLY WHICH ONLY PARTIALLY ERODES THROUGH
THE LATE AFTERNOON HOURS. SIGNIFICANT MLCAPE DOES EXIST IF LOW LEVEL
CONVERGENCE ASSOCIATED WITH FRONTAL BOUNDARY OR COMBINED FRONT AND
LAKE BREEZE BOUNDARY...ON THE ORDER OF 3500-4000 J/KG. THE
INCREASING ZONAL MID-LEVEL FLOW ALSO RESULTS IN 35-40 KTS OF 0-6 KM
BULK SHEAR WHICH WOULD INDICATE THAT IF A STORM IS ABLE TO DEVELOP
AND BREAK THROUGH THE CAP...THE THREAT EXISTS OF SEVERE WEATHER IN
THE FORM OF DAMAGING WINDS AND LARGE HAIL. OF COURSE...THE BIG
QUESTION IS WILL ANYTHING BE ABLE TO BUST THROUGH THE CAP! ODDS ARE
RATHER LOW THIS AFTERNOON INTO THIS EVENING...BUT WILL CONTINUE TO
MENTION A 20 PERCENT ISOLATED TS FOR THE OFF CHANCE THAT ONE
DEVELOPS AND CAUSES SOME PROBLEMS.
FRONT CONTINUES TO SAG ACROSS THE CWA THIS EVENING AND EVENTUALLY
BECOMES NEARLY STATIONARY FROM APPROXIMATELY THE IA/MO BORDER INTO
CENTRAL IL AND THE SOUTHERN CWA BORDER...AND REMAINS THERE MUCH OF
THE WEEKEND. WITH A SERIES OF SEVERAL MINOR AMPLITUDE SHORT WAVE
RIPPLES INDICATED BY GUIDANCE...THE POTENTIAL FOR PERIODIC
OCCASIONAL THUNDERSTORM CLUSTERS IS NOT ZERO. THE MOST LIKELY
SCENARIO AS INDICATED BY SEVERAL GUIDANCE SOLUTIONS IS FOR
DEVELOPMENT OF ELEVATED CONVECTION NORTH OF SURFACE BOUNDARY OVER
PARTS OF EASTERN NEBRASKA/WESTERN IOWA WHERE BETTER BACKED LOW LEVEL
FLOW AND ASSOCIATED MOISTURE CONVERGENCE AND THETA-E ADVECTION WILL
EXIST. STORMS WOULD THE LIKELY PROPAGATE EAST ALONG THE ELEVATED
BAROCLINIC ZONE AND MAY AFFECT THE WFO LOT AREA AT TIMES IN
WEAKENING PHASES. HAVE GENERALLY CARRIED LOW CHANCE POPS FOR
THIS...THOUGH SUSPECT THERE WILL BE MANY DRY HOURS THROUGH THE
WEEKEND IN BETWEEN THESE LITTLE MESOSCALE CLUSTERS OF STORMS.
THOUGH THE FRONT WILL BE SOUTH OF MUCH OF THE CWA...TEMPS IN THE
LOW-MID 90S WILL CONTINUE TO BE THE RULE...THOUGH WEAK FLOW WILL
ALLOW LAKE BREEZES TO COOL TEMPS INTO THE 80S ALONG LAKE MICHIGAN.
RATZER
&&
.CLIMATE...
908 PM CDT
...RECORD OR NEAR RECORD HIGHS POSSIBLE FOR THURSDAY JUNE 28TH...
THE CURRENT FORECAST HIGH IS 100 DEGREES FOR CHICAGO-OHARE AND 99 DEGREES
FOR ROCKFORD ON THURSDAY.
RECORD HIGHS FOR THURSDAY JUNE 28TH:
CHICAGO: 101/1971
ROCKFORD:103/1934
ALL-TIME JUNE RECORD HIGHS:
CHICAGO: 104...6/20/1988.
ROCKFORD: 106...6/1/1934.
ALL-TIME RECORD HIGHS:
CHICAGO: 105...7/24/1934
ROCKFORD: 112...7/14/1936
MDB/JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* LAKE BREEZE TURNING WINDS NORTHEASTERLY LATE THIS AFTERNOON OR
THIS EVENING.
* POTENTIAL FOR THUNDERSTORMS...WITH GREATEST THREAT BETWEEN
21-00Z ALONG AND JUST BEHIND COLD FRONT. BMD
//DISCUSSION...UPDATED 12Z...
THE MAIN FORECAST CONCERNS DURING THE PERIOD WILL BE THE WIND
FORECAST...IN PARTICULAR THE TIMING OF FRONTAL PASSAGE AND TIMING
OF LAKE BREEZE DEVELOPMENT. A SECONDARY CONCERN WILL BE THE SMALL
CHANCES FOR THUNDERSTORM DEVELOPMENT INVOF THE COLD FRONT.
A DIFFUSE COLD FRONT IS SLOWLY SAGGED SEWD THROUGH THE UPPER
MISSISSIPPI VALLEY AND IS EXPECTED TO MOVE INTO NWRN IL BY AROUND
NOON. AS THE FRONTAL TROUGH APPROACHES THE REGION...THE PRESSURE
GRADIENT ACROSS NRN IL/SRN LAKE MICHIGAN/NRN INDIANA WILL BECOME
RATHER WEAK...FURTHER DECREASING THE CONTRAST OF TEMPERATURES AND
WINDS ACROSS THE BOUNDARY AND EXPECT WINDS TO DECREASE. WITH VERY
WARM CONDITIONS DEVELOPING AHEAD OF THE FRONT...COMBINED WITH THE
DECREASING WINDS...IT SHOULD NOT BE TOO DIFFICULT TO DEVELOP A
LAKE BREEZE WITH THE CONTRAST OF NEAR 100F TEMPERATURES INLAND AND
THE MUCH COOLER LAKE MICHIGAN WATER. AS ALWAYS...THE CONCERN WILL
MORE BE TIMING RATHER THAN THE LIKELIHOOD OF LAKE BREEZE
DEVELOPMENT AND NELY FLOW SETTING UP OVER NERN IL AND NLY FLOW
SETTING UP OVER NWRN IN. AT THIS POINT...WILL TIME THE LAKE BREEZE
PUSHING INLAND AND PAST ORD/MDW IN THE 19-21Z TIMEFRAME.
AS FOR THUNDERSTORM POTENTIAL...THE INCREASING HEAT AND HUMIDITY
WILL LEAD TO A VERY UNSTABLE ENVIRONMENT AHEAD OF THE COLD
FRONT...BUT WARM AIR TRANSPORT UNDER SWLY FLOW ALOFT WILL LEAD TO
STRONG CAPPING AT 7KFT. THIS WILL INHIBIT CONVECTIVE
DEVELOPMENT...THROUGH MUCH OF THE AFTERNOON. MODEL GUIDANCE
SUGGESTS LITTLE WEAKENING TO THE CAP AND SINCE THE FRONTAL
BOUNDARY IS VERY DIFFUSE...WITH WILL NOT BE MUCH LOW LEVEL
FORCING. SO...WHILE CHANCES FOR THUNDERSTORM DEVELOPMENT IS NON-
ZERO...WILL CARRY A DRY FORECAST AND MONITOR THE LOCAL ENVIRONMENT
VERY CLOSELY THROUGH THE AFTERNOON AND EVENING HOURS.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM TO HIGH CONFIDENCE IN WIND DIRECTION TRENDS...BUT LOW
CONFIDENCE ON SPECIFIC TIMING OF LAKE BREEZE.
* LOW CONFIDENCE ON THUNDERSTORM EVOLUTION THIS AFTERNOON...TSRA
POSSIBLY DEVELOPING OVERHEAD WITH BEST WINDOW BETWEEN 21-00Z. BMD
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...VFR. SLIGHT CHANCE TSRA.
SATURDAY...VFR. CHANCE TSRA.
SUNDAY...VFR. CHANCE TSRA EARLY.
MONDAY...VFR. SLIGHT CHANCE TSRA.
TUESDAY...VFR. SLIGHT CHANCE TSRA.
WEDNESDAY...VFR. WX NIL.
KREIN
&&
.MARINE...
310 AM CDT
A LARGE AREA OF HIGH PRESSURE CENTERED OVER THE SOUTHERN
APPALACHIANS WILL CONTINUE TO SLOWLY DRIFT SOUTHEAST TODAY. LOW
PRESSURE WILL MOVE FROM MANITOBA NORTHEASTWARD TO HUDSON BAY
WHILE DRAGGING A COLD FRONT THROUGH THE UPPER MIDWEST AND THE
WESTERN GREAT LAKES REGION. WITH THE FRONT CONTINUING OFF TO THE
EAST THURSDAY NIGHT...A WEAK RIDGE OF HIGH PRESSURE WILL SPREAD
FROM THE NORTHERN PLAINS INTO THE GREAT LAKES. LOW PRESSURE OF
WILL MOVE FROM THE CENTRAL PLAINS INTO THE WESTERN GREAT LAKES
SATURDAY AND SATURDAY NIGHT BEFORE FILLING. ANOTHER COLD FRONT
WILL PUSH SOUTHEAST THROUGH THE UPPER GREAT LAKES SUNDAY NIGHT.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...HEAT ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-
ILZ032-ILZ033-ILZ039 UNTIL 8 PM THURSDAY.
IN...HEAT ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 8 PM
THURSDAY.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1017 AM CDT THU JUN 28 2012
.DISCUSSION...
1017 AM CDT
UPDATE FOR TODAY...HAVE REMOVED MENTION OF MORNING ISOLATED TSRA
ACROSS NW PORTION OF FA AS MINOR DISTURBANCE HAS ENCOUNTERED
INCREASINGLY DRY MID LEVELS AT TO MOVED E. IR SAT SHOWS CLOUD
TOPS HAVE WARMED DURING THE EARLY-MID MORNING.
HAVE TWEAKED DOWN MAX TEMPS BY 1 DEG S...AROUND 2 DEG N...AND
ABOUT 3-4 DEG ALONG N LAKESHORE. LEADING SURFACE TROUGH AND WIND
SHIFT LINE RUNS FROM SHEBOYGAN TO DUBUQUE AT 14Z. THE TRUE COOL
FRONT IS A BIT FURTHER BACK TO THE NW...RUNNING FROM THE BAY OF
GREEN BAY TO S OF LACROSSE...WITH SIGNIFICANT SURFACE DEW POINT
POOLING OCCURRING BETWEEN THE LEADING WIND SHIFT AND THE ACTUAL
FRONT.
LATEST MODEL GUIDANCE SHOWS THE WIND SHIFT DROPPING ACROSS THE
NORTHERN TIER OF COUNTIES BY 18Z AND THE CORE OF THE HOT AIR
BEING SUPPRESSED S TO THE SOUTHERN COUNTIES OF THE FA BY 00Z.
EXPECT THIS TO HOLD DOWN TEMPS JUST A BIT FROM EARLIER FORECASTS.
IN ADDITION...FOLLOWING WIND SHIFT TO OUT OF THE NW LOW LEVEL FLOW
APPEARS WEAK ENOUGH FOR THE WINDS TO FLOP OVER TO NE-E OFF OF THE
LAKE WHICH WILL RESULT IN TEMPERATURES COOLING ALONG THE FAR N
SHORE MID AFTERNOON AND FAR S SHORES LATE AFTERNOON.
AXIS OF INSTABILITY PROGGED TO BE BETWEEN THE LEAD TROUGH AND THE
COOL FRONT WHERE DEW POINTS IN THE UPPER 60S AND LOWER 70S TO BE
POOLED. THIS AXIS TO RUN W-E ACROSS THE NORTHERN COUNTIES AT 18Z
AND THE SOUTHERN COUNTIES AT 00Z. SHORT WAVE SEEN IN WATER VAPOR
SAT LOOP WAS MOVING TO THE FAR W END OF THE MN-IA BORDER AT 1345Z.
MODELS GENERALLY SHOW THIS DISTURBANCE TRACKING E ALONG THE MN-IA
BORDER THROUGH MID DAY THEN TURN ESE ACROSS SW WI AND N CENTRAL IL
DURING THE AFTERNOON. BEST CHANCE FOR TS DEVELOPMENT WILL BE WHERE
THE POOLED LOW LEVEL MOISTURE IS IN PLACE AND WHERE THE COOLER MID
LEVEL AIR ASSOCIATED WITH THE SHORT WAVE TROUGH REMOVES THE CAP
BASED AT AROUND 825HPA.
TRS
&&
.PREV DISCUSSION...
527 AM CDT
HAVE UPDATED FORECAST TO INCLUDE SLIGHT CHANCE MENTION OF
SHRA/TSRA FOR PARTS OF NORTH CENTRAL IL THROUGH MID-MORNING.
AREA OF ACCAS HAD DEVELOPED ACROSS PORTIONS OF CENTRAL AND EASTERN
IA EARLY THIS MORNING...IN REGION FAIRLY STRONG LOW-MID LEVEL
THETA-E ADVECTION ASSOCIATED WITH A SHORT WAVE TROUGH MOVING INTO
THE MID/UPPER MS VALLEY. SLATER IA PROFILER PLOT INDICATES WINDS
IN THE 0.5-3.0 KM LAYER HAVE INCREASED TO 50-60 KTS OVER THE PAST
FEW HOURS...WITH HIGH-BASED RADAR RETURNS DEVELOPING WITHIN
SOUTHERN PERIPHERY OF 2000-3000 J/KG MUCAPE AXIS. ASOS/AWOS SITES
ACROSS EASTERN IA REPORTING CLOUD BASES GENERALLY IN THE
9000-15000 FT RANGE...AND CEDAR RAPIDS RECENTLY REPORTED TSRA WITH
CLOUD BASES AT 11000 FT!
09Z RAP GUIDANCE INDICATES A GRADUAL DECREASE IN 850-700 MB
THETA-E ADVECTION OVER NORTHERN IL THROUGH MID-MORNING...WITH
RECENT RUNS OF THE HRRR ALSO INDICATING DECREASING CONVECTIVE
REFLECTIVITY SIGNATURES ACROSS NORTH CENTRAL IL BY THAT TIME. 06Z
WRF-NAM ISENTROPIC PROGS...ON THE 325K SURFACE...ALSO INDICATES
CONDENSATION PRESSURE DEFICITS SOMEWHAT HIGHER THAN CURRENTLY OVER
EASTERN IA. THUS AT THIS TIME HAVE ADDED SOME SLIGHT CHANCE POPS
BASICALLY NORTH OF A STERLING-BELVIDERE LINE THROUGH 16Z OR SO...
AND WILL HOPE THAT DISSIPATION TREND IN GUIDANCE OCCURS.
RATZER
//PREV DISCUSSION...
400 AM CDT
FORECAST CONCERNS REMAIN FOCUSED ON TRIPLE DIGIT HEAT FOR PORTIONS
OF THE FORECAST AREA TODAY...THEN SHIFT TO PERSISTENT BUT OVERALL
LOW PROBABILITIES OF PERIODIC ROUNDS OF THUNDERSTORMS THROUGH THE
WEEKEND AS COLD FRONT WHICH SAGS ACROSS AREA THIS AFTERNOON STALLS
ACROSS THE SOUTHERN CWA OR JUST OFF TO THE SOUTH TONIGHT.
UPPER RIDGE AXIS WAS ANALYZED ACROSS THE MID-MISSISSIPPI VALLEY AND
WESTERN GREAT LAKES REGION PER 00Z RAOB DATA. OVERNIGHT GOES WATER
VAPOR IMAGERY DEPICTS STRONG UPPER TROUGH SPREADING EAST ACROSS
MANITOBA AND WESTERN ONTARIO HOWEVER...WITH HEIGHT FALLS ALREADY
WORKING TO FLATTEN THE UPPER RIDGE ACROSS THE UPPER MIDWEST. THUS
THE UPPER RIDGE IS BEING SQUASHED SOUTHWARD TODAY ACROSS THE LOWER
MISSOURI AND LOWER OHIO VALLEYS AS FLOW BECOMES MORE ZONAL. AS THIS
OCCURS...LOW LEVEL THERMAL RIDGE OF +30-35 C TEMPS IN THE 925-850 MB
LAYER WILL ALSO BE SUPPRESSED SOUTH A BIT ACROSS SOUTHERN CWA AND
CENTRAL IL/IND AS HAS BEEN THE TREND OF GUIDANCE OVER THE PAST FEW
DAYS. THAT/S NOT TO SAY IT WONT BE HOT ACROSS THE WFO LOT CWA TODAY.
LOW LEVEL THERMAL PROGS CONTINUE TO SUPPORT AFTERNOON MAX TEMPS
RANGING FROM THE UPPER 90S NEAR THE IL/WI BORDER...TO THE 100-105
DEGREE RANGE ALONG/SOUTH OF THE I-80 CORRIDOR. CHICAGO MAY
OFFICIALLY HIT 100...THOUGH COMPLICATING FACTORS INCLUDING SLIGHTLY
FASTER COLD FRONTAL TIMING AND SHIFTING OF WINDS OFF OF LAKE
MICHIGAN BEHIND FROPA. THIS WILL LIKELY ALLOW TEMPS TO FALL BACK
INTO THE 80S THROUGH LATE AFTERNOON AT THE LAKE SHORE WHILE AREAS
FARTHER WEST/SOUTH CONTINUE TO BAKE AT NEARLY 100 DEGREES. SURFACE
DEW POINT TEMPS HAVE RISEN INTO THE MID/UPPER 60S ACROSS PARTS OF
WESTERN IL/SOUTHWEST WI AHEAD OF THE FRONT OVERNIGHT...AND DEW POINT
TEMPS WILL CONTINUE TO INCREASE AS LOW LEVEL MOISTURE POOLS WITHIN
THE FRONTAL ZONE TODAY. WHILE GUIDANCE DEW POINTS IN THE 75-80
DEGREE RANGE ARE LIKELY OVER-FORECAST...AFTERNOON DEWS SHOULD RANGE
FROM THE LOW-MID 60S OVER THE FAR SOUTHEAST...TO THE UPPER 60S TO
AROUND 70 ALONG THE IMMEDIATE FRONTAL ZONE. COUPLED WITH THE AIR
TEMPS MENTIONED ABOVE THIS YIELDS PEAK HEAT INDEX VALUES IN THE
105-110 RANGE...SUPPORTING NO CHANGES TO ONGOING HEAT ADVISORY.
COULD BE A LITTLE IFFY RIGHT ALONG THE LAKE MICHIGAN SHORE AS NOTED
ABOVE...THOUGH HAVE NO PLANS TO PULL HEADLINE AS HEAT INDEX VALUES
SHOULD REACH/EXCEED 100 NEARLY ALL LOCATIONS PRIOR TO FROPA/ONSHORE
WINDS THIS AFTERNOON. TEMPS MAY APPROACH CHICAGO RECORD HIGH OF 101
DEGREES...THOUGH ROCKFORDS 103 IS PROBABLY SAFE TODAY.
AS NOTED ABOVE...FRONT SAGS ACROSS CWA TODAY WITH LOW LEVEL MOISTURE
POOLING DEW POINT TEMPS NEAR 70 DEGREES WITHING THE FRONTAL ZONE.
WHILE SEVERAL MINOR AMPLITUDE SHORT WAVES ARE NOTED LINED UP
INCREASINGLY ZONAL MID/UPPER FLOW...FORECAST SOUNDINGS INDICATE
SUBSTANTIAL CAPPING INITIALLY WHICH ONLY PARTIALLY ERODES THROUGH
THE LATE AFTERNOON HOURS. SIGNIFICANT MLCAPE DOES EXIST IF LOW LEVEL
CONVERGENCE ASSOCIATED WITH FRONTAL BOUNDARY OR COMBINED FRONT AND
LAKE BREEZE BOUNDARY...ON THE ORDER OF 3500-4000 J/KG. THE
INCREASING ZONAL MID-LEVEL FLOW ALSO RESULTS IN 35-40 KTS OF 0-6 KM
BULK SHEAR WHICH WOULD INDICATE THAT IF A STORM IS ABLE TO DEVELOP
AND BREAK THROUGH THE CAP...THE THREAT EXISTS OF SEVERE WEATHER IN
THE FORM OF DAMAGING WINDS AND LARGE HAIL. OF COURSE...THE BIG
QUESTION IS WILL ANYTHING BE ABLE TO BUST THROUGH THE CAP! ODDS ARE
RATHER LOW THIS AFTERNOON INTO THIS EVENING...BUT WILL CONTINUE TO
MENTION A 20 PERCENT ISOLATED TS FOR THE OFF CHANCE THAT ONE
DEVELOPS AND CAUSES SOME PROBLEMS.
FRONT CONTINUES TO SAG ACROSS THE CWA THIS EVENING AND EVENTUALLY
BECOMES NEARLY STATIONARY FROM APPROXIMATELY THE IA/MO BORDER INTO
CENTRAL IL AND THE SOUTHERN CWA BORDER...AND REMAINS THERE MUCH OF
THE WEEKEND. WITH A SERIES OF SEVERAL MINOR AMPLITUDE SHORT WAVE
RIPPLES INDICATED BY GUIDANCE...THE POTENTIAL FOR PERIODIC
OCCASIONAL THUNDERSTORM CLUSTERS IS NOT ZERO. THE MOST LIKELY
SCENARIO AS INDICATED BY SEVERAL GUIDANCE SOLUTIONS IS FOR
DEVELOPMENT OF ELEVATED CONVECTION NORTH OF SURFACE BOUNDARY OVER
PARTS OF EASTERN NEBRASKA/WESTERN IOWA WHERE BETTER BACKED LOW LEVEL
FLOW AND ASSOCIATED MOISTURE CONVERGENCE AND THETA-E ADVECTION WILL
EXIST. STORMS WOULD THE LIKELY PROPAGATE EAST ALONG THE ELEVATED
BAROCLINIC ZONE AND MAY AFFECT THE WFO LOT AREA AT TIMES IN
WEAKENING PHASES. HAVE GENERALLY CARRIED LOW CHANCE POPS FOR
THIS...THOUGH SUSPECT THERE WILL BE MANY DRY HOURS THROUGH THE
WEEKEND IN BETWEEN THESE LITTLE MESOSCALE CLUSTERS OF STORMS.
THOUGH THE FRONT WILL BE SOUTH OF MUCH OF THE CWA...TEMPS IN THE
LOW-MID 90S WILL CONTINUE TO BE THE RULE...THOUGH WEAK FLOW WILL
ALLOW LAKE BREEZES TO COOL TEMPS INTO THE 80S ALONG LAKE MICHIGAN.
RATZER
&&
.CLIMATE...
908 PM CDT
...RECORD OR NEAR RECORD HIGHS POSSIBLE FOR THURSDAY JUNE 28TH...
THE CURRENT FORECAST HIGH IS 100 DEGREES FOR CHICAGO-OHARE AND 99 DEGREES
FOR ROCKFORD ON THURSDAY.
RECORD HIGHS FOR THURSDAY JUNE 28TH:
CHICAGO: 101/1971
ROCKFORD:103/1934
ALL-TIME JUNE RECORD HIGHS:
CHICAGO: 104...6/20/1988.
ROCKFORD: 106...6/1/1934.
ALL-TIME RECORD HIGHS:
CHICAGO: 105...7/24/1934
ROCKFORD: 112...7/14/1936
MDB/JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* WIND SHIFTS/TIMING ASSOCIATED WITH COLD FRONT DROPPING SOUTH
ACROSS TERMINALS THIS AFTERNOON.
* LAKE BREEZE TURNING WINDS NORHTEASTERLY LATE THIS AFTERNOON OR
THIS EVENING.
* POTENTIAL FOR THUNDERSTORMS...WITH GREATEST THREAT ALONG AND
JUST BEHIND COLD FRONT. BMD
//DISCUSSION...UPDATED 12Z...
THE MAIN FORECAST CONCERNS DURING THE PERIOD WILL BE THE WIND
FORECAST...IN PARTICULAR THE TIMING OF FRONTAL PASSAGE AND TIMING
OF LAKE BREEZE DEVELOPMENT. A SECONDARY CONCERN WILL BE THE SMALL
CHANCES FOR THUNDERSTORM DEVELOPMENT INVOF THE COLD FRONT.
A DIFFUSE COLD FRONT IS SLOWLY SAGGED SEWD THROUGH THE UPPER
MISSISSIPPI VALLEY AND IS EXPECTED TO MOVE INTO NWRN IL BY AROUND
NOON. AS THE FRONTAL TROUGH APPROACHES THE REGION...THE PRESSURE
GRADIENT ACROSS NRN IL/SRN LAKE MICHIGAN/NRN INDIANA WILL BECOME
RATHER WEAK...FURTHER DECREASING THE CONTRAST OF TEMPERATURES AND
WINDS ACROSS THE BOUNDARY AND EXPECT WINDS TO DECREASE. WITH VERY
WARM CONDITIONS DEVELOPING AHEAD OF THE FRONT...COMBINED WITH THE
DECREASING WINDS...IT SHOULD NOT BE TOO DIFFICULT TO DEVELOP A
LAKE BREEZE WITH THE CONTRAST OF NEAR 100F TEMPERATURES INLAND AND
THE MUCH COOLER LAKE MICHIGAN WATER. AS ALWAYS...THE CONCERN WILL
MORE BE TIMING RATHER THAN THE LIKELIHOOD OF LAKE BREEZE
DEVELOPMENT AND NELY FLOW SETTING UP OVER NERN IL AND NLY FLOW
SETTING UP OVER NWRN IN. AT THIS POINT...WILL TIME THE LAKE BREEZE
PUSHING INLAND AND PAST ORD/MDW IN THE 19-21Z TIMEFRAME.
AS FOR THUNDERSTORM POTENTIAL...THE INCREASING HEAT AND HUMIDITY
WILL LEAD TO A VERY UNSTABLE ENVIRONMENT AHEAD OF THE COLD
FRONT...BUT WARM AIR TRANSPORT UNDER SWLY FLOW ALOFT WILL LEAD TO
STRONG CAPPING AT 7KFT. THIS WILL INHIBIT CONVECTIVE
DEVELOPMENT...THROUGH MUCH OF THE AFTERNOON. MODEL GUIDANCE
SUGGESTS LITTLE WEAKENING TO THE CAP AND SINCE THE FRONTAL
BOUNDARY IS VERY DIFFUSE...WITH WILL NOT BE MUCH LOW LEVEL
FORCING. SO...WHILE CHANCES FOR THUNDERSTORM DEVELOPMENT IS NON-
ZERO...WILL CARRY A DRY FORECAST AND MONITOR THE LOCAL ENVIRONMENT
VERY CLOSELY THROUGH THE AFTERNOON AND EVENING HOURS.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* MEDIUM TO HIGH CONFIDENCE IN WIND DIRECTION TRENDS...FROM WSW
THIS MORNING TO NE BY LATE AFTERNOON/EARLY EVENING...BUT LOW TO
MEDIUM CONFIDENCE ON SPECIFIC TIMING OF WIND SHIFTS ASSOCD WITH
FROPA AND LAKE BREEZE.
* LOW CONFIDENCE ON TSRA IMPACTING TERMINALS THIS AFTERNOON/EVENING.
BMD
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...VFR. SLIGHT CHANCE TSRA.
SATURDAY...VFR. CHANCE TSRA.
SUNDAY...VFR. CHANCE TSRA EARLY.
MONDAY...VFR. SLIGHT CHANCE TSRA.
TUESDAY...VFR. SLIGHT CHANCE TSRA.
WEDNESDAY...VFR. WX NIL.
KREIN
&&
.MARINE...
310 AM CDT
A LARGE AREA OF HIGH PRESSURE CENTERED OVER THE SOUTHERN
APPALACHIANS WILL CONTINUE TO SLOWLY DRIFT SOUTHEAST TODAY. LOW
PRESSURE WILL MOVE FROM MANITOBA NORTHEASTWARD TO HUDSON BAY
WHILE DRAGGING A COLD FRONT THROUGH THE UPPER MIDWEST AND THE
WESTERN GREAT LAKES REGION. WITH THE FRONT CONTINUING OFF TO THE
EAST THURSDAY NIGHT...A WEAK RIDGE OF HIGH PRESSURE WILL SPREAD
FROM THE NORTHERN PLAINS INTO THE GREAT LAKES. LOW PRESSURE OF
WILL MOVE FROM THE CENTRAL PLAINS INTO THE WESTERN GREAT LAKES
SATURDAY AND SATURDAY NIGHT BEFORE FILLING. ANOTHER COLD FRONT
WILL PUSH SOUTHEAST THROUGH THE UPPER GREAT LAKES SUNDAY NIGHT.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...HEAT ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-
ILZ032-ILZ033-ILZ039 UNTIL 8 PM THURSDAY.
IN...HEAT ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 8 PM
THURSDAY.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
903 AM CDT THU JUN 28 2012
.DISCUSSION...
527 AM CDT
HAVE UPDATED FORECAST TO INCLUDE SLIGHT CHANCE MENTION OF
SHRA/TSRA FOR PARTS OF NORTH CENTRAL IL THROUGH MID-MORNING.
AREA OF ACCAS HAD DEVELOPED ACROSS PORTIONS OF CENTRAL AND EASTERN
IA EARLY THIS MORNING...IN REGION FAIRLY STRONG LOW-MID LEVEL
THETA-E ADVECTION ASSOCIATED WITH A SHORT WAVE TROUGH MOVING INTO
THE MID/UPPER MS VALLEY. SLATER IA PROFILER PLOT INDICATES WINDS
IN THE 0.5-3.0 KM LAYER HAVE INCREASED TO 50-60 KTS OVER THE PAST
FEW HOURS...WITH HIGH-BASED RADAR RETURNS DEVELOPING WITHIN
SOUTHERN PERIPHERY OF 2000-3000 J/KG MUCAPE AXIS. ASOS/AWOS SITES
ACROSS EASTERN IA REPORTING CLOUD BASES GENERALLY IN THE
9000-15000 FT RANGE...AND CEDAR RAPIDS RECENTLY REPORTED TSRA WITH
CLOUD BASES AT 11000 FT!
09Z RAP GUIDANCE INDICATES A GRADUAL DECREASE IN 850-700 MB
THETA-E ADVECTION OVER NORTHERN IL THROUGH MID-MORNING...WITH
RECENT RUNS OF THE HRRR ALSO INDICATING DECREASING CONVECTIVE
REFLECTIVITY SIGNATURES ACROSS NORTH CENTRAL IL BY THAT TIME. 06Z
WRF-NAM ISENTROPIC PROGS...ON THE 325K SURFACE...ALSO INDICATES
CONDENSATION PRESSURE DEFICITS SOMEWHAT HIGHER THAN CURRENTLY OVER
EASTERN IA. THUS AT THIS TIME HAVE ADDED SOME SLIGHT CHANCE POPS
BASICALLY NORTH OF A STERLING-BELVIDERE LINE THROUGH 16Z OR SO...
AND WILL HOPE THAT DISSIPATION TREND IN GUIDANCE OCCURS.
RATZER
//PREV DISCUSSION...
400 AM CDT
FORECAST CONCERNS REMAIN FOCUSED ON TRIPLE DIGIT HEAT FOR PORTIONS
OF THE FORECAST AREA TODAY...THEN SHIFT TO PERSISTENT BUT OVERALL
LOW PROBABILITIES OF PERIODIC ROUNDS OF THUNDERSTORMS THROUGH THE
WEEKEND AS COLD FRONT WHICH SAGS ACROSS AREA THIS AFTERNOON STALLS
ACROSS THE SOUTHERN CWA OR JUST OFF TO THE SOUTH TONIGHT.
UPPER RIDGE AXIS WAS ANALYZED ACROSS THE MID-MISSISSIPPI VALLEY AND
WESTERN GREAT LAKES REGION PER 00Z RAOB DATA. OVERNIGHT GOES WATER
VAPOR IMAGERY DEPICTS STRONG UPPER TROUGH SPREADING EAST ACROSS
MANITOBA AND WESTERN ONTARIO HOWEVER...WITH HEIGHT FALLS ALREADY
WORKING TO FLATTEN THE UPPER RIDGE ACROSS THE UPPER MIDWEST. THUS
THE UPPER RIDGE IS BEING SQUASHED SOUTHWARD TODAY ACROSS THE LOWER
MISSOURI AND LOWER OHIO VALLEYS AS FLOW BECOMES MORE ZONAL. AS THIS
OCCURS...LOW LEVEL THERMAL RIDGE OF +30-35 C TEMPS IN THE 925-850 MB
LAYER WILL ALSO BE SUPPRESSED SOUTH A BIT ACROSS SOUTHERN CWA AND
CENTRAL IL/IND AS HAS BEEN THE TREND OF GUIDANCE OVER THE PAST FEW
DAYS. THAT/S NOT TO SAY IT WONT BE HOT ACROSS THE WFO LOT CWA TODAY.
LOW LEVEL THERMAL PROGS CONTINUE TO SUPPORT AFTERNOON MAX TEMPS
RANGING FROM THE UPPER 90S NEAR THE IL/WI BORDER...TO THE 100-105
DEGREE RANGE ALONG/SOUTH OF THE I-80 CORRIDOR. CHICAGO MAY
OFFICIALLY HIT 100...THOUGH COMPLICATING FACTORS INCLUDING SLIGHTLY
FASTER COLD FRONTAL TIMING AND SHIFTING OF WINDS OFF OF LAKE
MICHIGAN BEHIND FROPA. THIS WILL LIKELY ALLOW TEMPS TO FALL BACK
INTO THE 80S THROUGH LATE AFTERNOON AT THE LAKE SHORE WHILE AREAS
FARTHER WEST/SOUTH CONTINUE TO BAKE AT NEARLY 100 DEGREES. SURFACE
DEW POINT TEMPS HAVE RISEN INTO THE MID/UPPER 60S ACROSS PARTS OF
WESTERN IL/SOUTHWEST WI AHEAD OF THE FRONT OVERNIGHT...AND DEW POINT
TEMPS WILL CONTINUE TO INCREASE AS LOW LEVEL MOISTURE POOLS WITHIN
THE FRONTAL ZONE TODAY. WHILE GUIDANCE DEW POINTS IN THE 75-80
DEGREE RANGE ARE LIKELY OVER-FORECAST...AFTERNOON DEWS SHOULD RANGE
FROM THE LOW-MID 60S OVER THE FAR SOUTHEAST...TO THE UPPER 60S TO
AROUND 70 ALONG THE IMMEDIATE FRONTAL ZONE. COUPLED WITH THE AIR
TEMPS MENTIONED ABOVE THIS YIELDS PEAK HEAT INDEX VALUES IN THE
105-110 RANGE...SUPPORTING NO CHANGES TO ONGOING HEAT ADVISORY.
COULD BE A LITTLE IFFY RIGHT ALONG THE LAKE MICHIGAN SHORE AS NOTED
ABOVE...THOUGH HAVE NO PLANS TO PULL HEADLINE AS HEAT INDEX VALUES
SHOULD REACH/EXCEED 100 NEARLY ALL LOCATIONS PRIOR TO FROPA/ONSHORE
WINDS THIS AFTERNOON. TEMPS MAY APPROACH CHICAGO RECORD HIGH OF 101
DEGREES...THOUGH ROCKFORDS 103 IS PROBABLY SAFE TODAY.
AS NOTED ABOVE...FRONT SAGS ACROSS CWA TODAY WITH LOW LEVEL MOISTURE
POOLING DEW POINT TEMPS NEAR 70 DEGREES WITHING THE FRONTAL ZONE.
WHILE SEVERAL MINOR AMPLITUDE SHORT WAVES ARE NOTED LINED UP
INCREASINGLY ZONAL MID/UPPER FLOW...FORECAST SOUNDINGS INDICATE
SUBSTANTIAL CAPPING INITIALLY WHICH ONLY PARTIALLY ERODES THROUGH
THE LATE AFTERNOON HOURS. SIGNIFICANT MLCAPE DOES EXIST IF LOW LEVEL
CONVERGENCE ASSOCIATED WITH FRONTAL BOUNDARY OR COMBINED FRONT AND
LAKE BREEZE BOUNDARY...ON THE ORDER OF 3500-4000 J/KG. THE
INCREASING ZONAL MID-LEVEL FLOW ALSO RESULTS IN 35-40 KTS OF 0-6 KM
BULK SHEAR WHICH WOULD INDICATE THAT IF A STORM IS ABLE TO DEVELOP
AND BREAK THROUGH THE CAP...THE THREAT EXISTS OF SEVERE WEATHER IN
THE FORM OF DAMAGING WINDS AND LARGE HAIL. OF COURSE...THE BIG
QUESTION IS WILL ANYTHING BE ABLE TO BUST THROUGH THE CAP! ODDS ARE
RATHER LOW THIS AFTERNOON INTO THIS EVENING...BUT WILL CONTINUE TO
MENTION A 20 PERCENT ISOLATED TS FOR THE OFF CHANCE THAT ONE
DEVELOPS AND CAUSES SOME PROBLEMS.
FRONT CONTINUES TO SAG ACROSS THE CWA THIS EVENING AND EVENTUALLY
BECOMES NEARLY STATIONARY FROM APPROXIMATELY THE IA/MO BORDER INTO
CENTRAL IL AND THE SOUTHERN CWA BORDER...AND REMAINS THERE MUCH OF
THE WEEKEND. WITH A SERIES OF SEVERAL MINOR AMPLITUDE SHORT WAVE
RIPPLES INDICATED BY GUIDANCE...THE POTENTIAL FOR PERIODIC
OCCASIONAL THUNDERSTORM CLUSTERS IS NOT ZERO. THE MOST LIKELY
SCENARIO AS INDICATED BY SEVERAL GUIDANCE SOLUTIONS IS FOR
DEVELOPMENT OF ELEVATED CONVECTION NORTH OF SURFACE BOUNDARY OVER
PARTS OF EASTERN NEBRASKA/WESTERN IOWA WHERE BETTER BACKED LOW LEVEL
FLOW AND ASSOCIATED MOISTURE CONVERGENCE AND THETA-E ADVECTION WILL
EXIST. STORMS WOULD THE LIKELY PROPAGATE EAST ALONG THE ELEVATED
BAROCLINIC ZONE AND MAY AFFECT THE WFO LOT AREA AT TIMES IN
WEAKENING PHASES. HAVE GENERALLY CARRIED LOW CHANCE POPS FOR
THIS...THOUGH SUSPECT THERE WILL BE MANY DRY HOURS THROUGH THE
WEEKEND IN BETWEEN THESE LITTLE MESOSCALE CLUSTERS OF STORMS.
THOUGH THE FRONT WILL BE SOUTH OF MUCH OF THE CWA...TEMPS IN THE
LOW-MID 90S WILL CONTINUE TO BE THE RULE...THOUGH WEAK FLOW WILL
ALLOW LAKE BREEZES TO COOL TEMPS INTO THE 80S ALONG LAKE MICHIGAN.
RATZER
&&
.CLIMATE...
908 PM CDT
...RECORD OR NEAR RECORD HIGHS POSSIBLE FOR THURSDAY JUNE 28TH...
THE CURRENT FORECAST HIGH IS 100 DEGREES FOR CHICAGO-OHARE AND 99 DEGREES
FOR ROCKFORD ON THURSDAY.
RECORD HIGHS FOR THURSDAY JUNE 28TH:
CHICAGO: 101/1971
ROCKFORD:103/1934
ALL-TIME JUNE RECORD HIGHS:
CHICAGO: 104...6/20/1988.
ROCKFORD: 106...6/1/1934.
ALL-TIME RECORD HIGHS:
CHICAGO: 105...7/24/1934
ROCKFORD: 112...7/14/1936
MDB/JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* WIND SHIFTS/TIMING ASSOCIATED WITH COLD FRONT DROPPING SOUTH
ACROSS TERMINALS THIS AFTERNOON.
* LAKE BREEZE TURNING WINDS NORHTEASTERLY LATE THIS AFTERNOON OR
THIS EVENING.
* POTENTIAL FOR THUNDERSTORMS...WITH GREATEST THREAT ALONG AND
JUST BEHIND COLD FRONT. BMD
//DISCUSSION...UPDATED 12Z...
THE MAIN FORECAST CONCERNS DURING THE PERIOD WILL BE THE WIND
FORECAST...IN PARTICULAR THE TIMING OF FRONTAL PASSAGE AND TIMING
OF LAKE BREEZE DEVELOPMENT. A SECONDARY CONCERN WILL BE THE SMALL
CHANCES FOR THUNDERSTORM DEVELOPMENT INVOF THE COLD FRONT.
A DIFFUSE COLD FRONT IS SLOWLY SAGGED SEWD THROUGH THE UPPER
MISSISSIPPI VALLEY AND IS EXPECTED TO MOVE INTO NWRN IL BY AROUND
NOON. AS THE FRONTAL TROUGH APPROACHES THE REGION...THE PRESSURE
GRADIENT ACROSS NRN IL/SRN LAKE MICHIGAN/NRN INDIANA WILL BECOME
RATHER WEAK...FURTHER DECREASING THE CONTRAST OF TEMPERATURES AND
WINDS ACROSS THE BOUNDARY AND EXPECT WINDS TO DECREASE. WITH VERY
WARM CONDITIONS DEVELOPING AHEAD OF THE FRONT...COMBINED WITH THE
DECREASING WINDS...IT SHOULD NOT BE TOO DIFFICULT TO DEVELOP A
LAKE BREEZE WITH THE CONTRAST OF NEAR 100F TEMPERATURES INLAND AND
THE MUCH COOLER LAKE MICHIGAN WATER. AS ALWAYS...THE CONCERN WILL
MORE BE TIMING RATHER THAN THE LIKELIHOOD OF LAKE BREEZE
DEVELOPMENT AND NELY FLOW SETTING UP OVER NERN IL AND NLY FLOW
SETTING UP OVER NWRN IN. AT THIS POINT...WILL TIME THE LAKE BREEZE
PUSHING INLAND AND PAST ORD/MDW IN THE 19-21Z TIMEFRAME.
AS FOR THUNDERSTORM POTENTIAL...THE INCREASING HEAT AND HUMIDITY
WILL LEAD TO A VERY UNSTABLE ENVIRONMENT AHEAD OF THE COLD
FRONT...BUT WARM AIR TRANSPORT UNDER SWLY FLOW ALOFT WILL LEAD TO
STRONG CAPPING AT 7KFT. THIS WILL INHIBIT CONVECTIVE
DEVELOPMENT...THROUGH MUCH OF THE AFTERNOON. MODEL GUIDANCE
SUGGESTS LITTLE WEAKENING TO THE CAP AND SINCE THE FRONTAL
BOUNDARY IS VERY DIFFUSE...WITH WILL NOT BE MUCH LOW LEVEL
FORCING. SO...WHILE CHANCES FOR THUNDERSTORM DEVELOPMENT IS NON-
ZERO...WILL CARRY A DRY FORECAST AND MONITOR THE LOCAL ENVIRONMENT
VERY CLOSELY THROUGH THE AFTERNOON AND EVENING HOURS.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* MEDIUM TO HIGH CONFIDENCE IN WIND DIRECTION TRENDS...FROM WSW
THIS MORNING TO NE BY LATE AFTERNOON/EARLY EVENING...BUT LOW TO
MEDIUM CONFIDENCE ON SPECIFIC TIMING OF WIND SHIFTS ASSOCD WITH
FROPA AND LAKE BREEZE.
* LOW CONFIDENCE ON TSRA IMPACTING TERMINALS THIS AFTERNOON/EVENING.
BMD
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...VFR. SLIGHT CHANCE TSRA.
SATURDAY...VFR. CHANCE TSRA.
SUNDAY...VFR. CHANCE TSRA EARLY.
MONDAY...VFR. SLIGHT CHANCE TSRA.
TUESDAY...VFR. SLIGHT CHANCE TSRA.
WEDNESDAY...VFR. WX NIL.
KREIN
&&
.MARINE...
310 AM CDT
A LARGE AREA OF HIGH PRESSURE CENTERED OVER THE SOUTHERN
APPALACHIANS WILL CONTINUE TO SLOWLY DRIFT SOUTHEAST TODAY. LOW
PRESSURE WILL MOVE FROM MANITOBA NORTHEASTWARD TO HUDSON BAY
WHILE DRAGGING A COLD FRONT THROUGH THE UPPER MIDWEST AND THE
WESTERN GREAT LAKES REGION. WITH THE FRONT CONTINUING OFF TO THE
EAST THURSDAY NIGHT...A WEAK RIDGE OF HIGH PRESSURE WILL SPREAD
FROM THE NORTHERN PLAINS INTO THE GREAT LAKES. LOW PRESSURE OF
WILL MOVE FROM THE CENTRAL PLAINS INTO THE WESTERN GREAT LAKES
SATURDAY AND SATURDAY NIGHT BEFORE FILLING. ANOTHER COLD FRONT
WILL PUSH SOUTHEAST THROUGH THE UPPER GREAT LAKES SUNDAY NIGHT.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...HEAT ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-
ILZ032-ILZ033-ILZ039 UNTIL 8 PM THURSDAY.
IN...HEAT ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 8 PM
THURSDAY.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
612 AM CDT THU JUN 28 2012
.DISCUSSION...
527 AM CDT
HAVE UPDATED FORECAST TO INCLUDE SLIGHT CHANCE MENTION OF
SHRA/TSRA FOR PARTS OF NORTH CENTRAL IL THROUGH MID-MORNING.
AREA OF ACCAS HAD DEVELOPED ACROSS PORTIONS OF CENTRAL AND EASTERN
IA EARLY THIS MORNING...IN REGION FAIRLY STRONG LOW-MID LEVEL
THETA-E ADVECTION ASSOCIATED WITH A SHORT WAVE TROUGH MOVING INTO
THE MID/UPPER MS VALLEY. SLATER IA PROFILER PLOT INDICATES WINDS
IN THE 0.5-3.0 KM LAYER HAVE INCREASED TO 50-60 KTS OVER THE PAST
FEW HOURS...WITH HIGH-BASED RADAR RETURNS DEVELOPING WITHIN
SOUTHERN PERIPHERY OF 2000-3000 J/KG MUCAPE AXIS. ASOS/AWOS SITES
ACROSS EASTERN IA REPORTING CLOUD BASES GENERALLY IN THE
9000-15000 FT RANGE...AND CEDAR RAPIDS RECENTLY REPORTED TSRA WITH
CLOUD BASES AT 11000 FT!
09Z RAP GUIDANCE INDICATES A GRADUAL DECREASE IN 850-700 MB
THETA-E ADVECTION OVER NORTHERN IL THROUGH MID-MORNING...WITH
RECENT RUNS OF THE HRRR ALSO INDICATING DECREASING CONVECTIVE
REFLECTIVITY SIGNATURES ACROSS NORTH CENTRAL IL BY THAT TIME. 06Z
WRF-NAM ISENTROPIC PROGS...ON THE 325K SURFACE...ALSO INDICATES
CONDENSATION PRESSURE DEFICITS SOMEWHAT HIGHER THAN CURRENTLY OVER
EASTERN IA. THUS AT THIS TIME HAVE ADDED SOME SLIGHT CHANCE POPS
BASICALLY NORTH OF A STERLING-BELVIDERE LINE THROUGH 16Z OR SO...
AND WILL HOPE THAT DISSIPATION TREND IN GUIDANCE OCCURS.
RATZER
//PREV DISCUSSION...
400 AM CDT
FORECAST CONCERNS REMAIN FOCUSED ON TRIPLE DIGIT HEAT FOR PORTIONS
OF THE FORECAST AREA TODAY...THEN SHIFT TO PERSISTENT BUT OVERALL
LOW PROBABILITIES OF PERIODIC ROUNDS OF THUNDERSTORMS THROUGH THE
WEEKEND AS COLD FRONT WHICH SAGS ACROSS AREA THIS AFTERNOON STALLS
ACROSS THE SOUTHERN CWA OR JUST OFF TO THE SOUTH TONIGHT.
UPPER RIDGE AXIS WAS ANALYZED ACROSS THE MID-MISSISSIPPI VALLEY AND
WESTERN GREAT LAKES REGION PER 00Z RAOB DATA. OVERNIGHT GOES WATER
VAPOR IMAGERY DEPICTS STRONG UPPER TROUGH SPREADING EAST ACROSS
MANITOBA AND WESTERN ONTARIO HOWEVER...WITH HEIGHT FALLS ALREADY
WORKING TO FLATTEN THE UPPER RIDGE ACROSS THE UPPER MIDWEST. THUS
THE UPPER RIDGE IS BEING SQUASHED SOUTHWARD TODAY ACROSS THE LOWER
MISSOURI AND LOWER OHIO VALLEYS AS FLOW BECOMES MORE ZONAL. AS THIS
OCCURS...LOW LEVEL THERMAL RIDGE OF +30-35 C TEMPS IN THE 925-850 MB
LAYER WILL ALSO BE SUPPRESSED SOUTH A BIT ACROSS SOUTHERN CWA AND
CENTRAL IL/IND AS HAS BEEN THE TREND OF GUIDANCE OVER THE PAST FEW
DAYS. THAT/S NOT TO SAY IT WONT BE HOT ACROSS THE WFO LOT CWA TODAY.
LOW LEVEL THERMAL PROGS CONTINUE TO SUPPORT AFTERNOON MAX TEMPS
RANGING FROM THE UPPER 90S NEAR THE IL/WI BORDER...TO THE 100-105
DEGREE RANGE ALONG/SOUTH OF THE I-80 CORRIDOR. CHICAGO MAY
OFFICIALLY HIT 100...THOUGH COMPLICATING FACTORS INCLUDING SLIGHTLY
FASTER COLD FRONTAL TIMING AND SHIFTING OF WINDS OFF OF LAKE
MICHIGAN BEHIND FROPA. THIS WILL LIKELY ALLOW TEMPS TO FALL BACK
INTO THE 80S THROUGH LATE AFTERNOON AT THE LAKE SHORE WHILE AREAS
FARTHER WEST/SOUTH CONTINUE TO BAKE AT NEARLY 100 DEGREES. SURFACE
DEW POINT TEMPS HAVE RISEN INTO THE MID/UPPER 60S ACROSS PARTS OF
WESTERN IL/SOUTHWEST WI AHEAD OF THE FRONT OVERNIGHT...AND DEW POINT
TEMPS WILL CONTINUE TO INCREASE AS LOW LEVEL MOISTURE POOLS WITHIN
THE FRONTAL ZONE TODAY. WHILE GUIDANCE DEW POINTS IN THE 75-80
DEGREE RANGE ARE LIKELY OVER-FORECAST...AFTERNOON DEWS SHOULD RANGE
FROM THE LOW-MID 60S OVER THE FAR SOUTHEAST...TO THE UPPER 60S TO
AROUND 70 ALONG THE IMMEDIATE FRONTAL ZONE. COUPLED WITH THE AIR
TEMPS MENTIONED ABOVE THIS YIELDS PEAK HEAT INDEX VALUES IN THE
105-110 RANGE...SUPPORTING NO CHANGES TO ONGOING HEAT ADVISORY.
COULD BE A LITTLE IFFY RIGHT ALONG THE LAKE MICHIGAN SHORE AS NOTED
ABOVE...THOUGH HAVE NO PLANS TO PULL HEADLINE AS HEAT INDEX VALUES
SHOULD REACH/EXCEED 100 NEARLY ALL LOCATIONS PRIOR TO FROPA/ONSHORE
WINDS THIS AFTERNOON. TEMPS MAY APPROACH CHICAGO RECORD HIGH OF 101
DEGREES...THOUGH ROCKFORDS 103 IS PROBABLY SAFE TODAY.
AS NOTED ABOVE...FRONT SAGS ACROSS CWA TODAY WITH LOW LEVEL MOISTURE
POOLING DEW POINT TEMPS NEAR 70 DEGREES WITHING THE FRONTAL ZONE.
WHILE SEVERAL MINOR AMPLITUDE SHORT WAVES ARE NOTED LINED UP
INCREASINGLY ZONAL MID/UPPER FLOW...FORECAST SOUNDINGS INDICATE
SUBSTANTIAL CAPPING INITIALLY WHICH ONLY PARTIALLY ERODES THROUGH
THE LATE AFTERNOON HOURS. SIGNIFICANT MLCAPE DOES EXIST IF LOW LEVEL
CONVERGENCE ASSOCIATED WITH FRONTAL BOUNDARY OR COMBINED FRONT AND
LAKE BREEZE BOUNDARY...ON THE ORDER OF 3500-4000 J/KG. THE
INCREASING ZONAL MID-LEVEL FLOW ALSO RESULTS IN 35-40 KTS OF 0-6 KM
BULK SHEAR WHICH WOULD INDICATE THAT IF A STORM IS ABLE TO DEVELOP
AND BREAK THROUGH THE CAP...THE THREAT EXISTS OF SEVERE WEATHER IN
THE FORM OF DAMAGING WINDS AND LARGE HAIL. OF COURSE...THE BIG
QUESTION IS WILL ANYTHING BE ABLE TO BUST THROUGH THE CAP! ODDS ARE
RATHER LOW THIS AFTERNOON INTO THIS EVENING...BUT WILL CONTINUE TO
MENTION A 20 PERCENT ISOLATED TS FOR THE OFF CHANCE THAT ONE
DEVELOPS AND CAUSES SOME PROBLEMS.
FRONT CONTINUES TO SAG ACROSS THE CWA THIS EVENING AND EVENTUALLY
BECOMES NEARLY STATIONARY FROM APPROXIMATELY THE IA/MO BORDER INTO
CENTRAL IL AND THE SOUTHERN CWA BORDER...AND REMAINS THERE MUCH OF
THE WEEKEND. WITH A SERIES OF SEVERAL MINOR AMPLITUDE SHORT WAVE
RIPPLES INDICATED BY GUIDANCE...THE POTENTIAL FOR PERIODIC
OCCASIONAL THUNDERSTORM CLUSTERS IS NOT ZERO. THE MOST LIKELY
SCENARIO AS INDICATED BY SEVERAL GUIDANCE SOLUTIONS IS FOR
DEVELOPMENT OF ELEVATED CONVECTION NORTH OF SURFACE BOUNDARY OVER
PARTS OF EASTERN NEBRASKA/WESTERN IOWA WHERE BETTER BACKED LOW LEVEL
FLOW AND ASSOCIATED MOISTURE CONVERGENCE AND THETA-E ADVECTION WILL
EXIST. STORMS WOULD THE LIKELY PROPAGATE EAST ALONG THE ELEVATED
BAROCLINIC ZONE AND MAY AFFECT THE WFO LOT AREA AT TIMES IN
WEAKENING PHASES. HAVE GENERALLY CARRIED LOW CHANCE POPS FOR
THIS...THOUGH SUSPECT THERE WILL BE MANY DRY HOURS THROUGH THE
WEEKEND IN BETWEEN THESE LITTLE MESOSCALE CLUSTERS OF STORMS.
THOUGH THE FRONT WILL BE SOUTH OF MUCH OF THE CWA...TEMPS IN THE
LOW-MID 90S WILL CONTINUE TO BE THE RULE...THOUGH WEAK FLOW WILL
ALLOW LAKE BREEZES TO COOL TEMPS INTO THE 80S ALONG LAKE MICHIGAN.
RATZER
&&
.CLIMATE...
908 PM CDT
...RECORD OR NEAR RECORD HIGHS POSSIBLE FOR THURSDAY JUNE 28TH...
THE CURRENT FORECAST HIGH IS 100 DEGREES FOR CHICAGO-OHARE AND 99 DEGREES
FOR ROCKFORD ON THURSDAY.
RECORD HIGHS FOR THURSDAY JUNE 28TH:
CHICAGO: 101/1971
ROCKFORD:103/1934
ALL-TIME JUNE RECORD HIGHS:
CHICAGO: 104...6/20/1988.
ROCKFORD: 106...6/1/1934.
ALL-TIME RECORD HIGHS:
CHICAGO: 105...7/24/1934
ROCKFORD: 112...7/14/1936
MDB/JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* FROPA TIMING THIS AFTERNOON AND PRECIP CHANCES ALONG FRONT.
* POTENTIAL FOR LAKE BREEZE THIS AFTERNOON.
KREIN
//DISCUSSION...UPDATED 12Z...
THE MAIN FORECAST CONCERNS DURING THE PERIOD WILL BE THE WIND
FORECAST...IN PARTICULAR THE TIMING OF FRONTAL PASSAGE AND TIMING
OF LAKE BREEZE DEVELOPMENT. A SECONDARY CONCERN WILL BE THE SMALL
CHANCES FOR THUNDERSTORM DEVELOPMENT INVOF THE COLD FRONT.
A DIFFUSE COLD FRONT IS SLOWLY SAGGED SEWD THROUGH THE UPPER
MISSISSIPPI VALLEY AND IS EXPECTED TO MOVE INTO NWRN IL BY AROUND
NOON. AS THE FRONTAL TROUGH APPROACHES THE REGION...THE PRESSURE
GRADIENT ACROSS NRN IL/SRN LAKE MICHIGAN/NRN INDIANA WILL BECOME
RATHER WEAK...FURTHER DECREASING THE CONTRAST OF TEMPERATURES AND
WINDS ACROSS THE BOUNDARY AND EXPECT WINDS TO DECREASE. WITH VERY
WARM CONDITIONS DEVELOPING AHEAD OF THE FRONT...COMBINED WITH THE
DECREASING WINDS...IT SHOULD NOT BE TOO DIFFICULT TO DEVELOP A
LAKE BREEZE WITH THE CONTRAST OF NEAR 100F TEMPERATURES INLAND AND
THE MUCH COOLER LAKE MICHIGAN WATER. AS ALWAYS...THE CONCERN WILL
MORE BE TIMING RATHER THAN THE LIKELIHOOD OF LAKE BREEZE
DEVELOPMENT AND NELY FLOW SETTING UP OVER NERN IL AND NLY FLOW
SETTING UP OVER NWRN IN. AT THIS POINT...WILL TIME THE LAKE BREEZE
PUSHING INLAND AND PAST ORD/MDW IN THE 19-21Z TIMEFRAME.
AS FOR THUNDERSTORM POTENTIAL...THE INCREASING HEAT AND HUMIDITY
WILL LEAD TO A VERY UNSTABLE ENVIRONMENT AHEAD OF THE COLD
FRONT...BUT WARM AIR TRANSPORT UNDER SWLY FLOW ALOFT WILL LEAD TO
STRONG CAPPING AT 7KFT. THIS WILL INHIBIT CONVECTIVE
DEVELOPMENT...THROUGH MUCH OF THE AFTERNOON. MODEL GUIDANCE
SUGGESTS LITTLE WEAKENING TO THE CAP AND SINCE THE FRONTAL
BOUNDARY IS VERY DIFFUSE...WITH WILL NOT BE MUCH LOW LEVEL
FORCING. SO...WHILE CHANCES FOR THUNDERSTORM DEVELOPMENT IS NON-
ZERO...WILL CARRY A DRY FORECAST AND MONITOR THE LOCAL ENVIRONMENT
VERY CLOSELY THROUGH THE AFTERNOON AND EVENING HOURS.
KREIN
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* MEDIUM TO HIGH CONFIDENCE IN WINDS BECOMING NORTHEASTERLY LATER
THURSDAY AFTERNOON...BUT LOWER CONFIDENCE IN THE TIMING.
* LOW CONFIDENCE IN THUNDERSTORMS IMPACTING THE TERMINALS THURSDAY
AFTERNOON AND EVENING.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...VFR. SLIGHT CHANCE TSRA.
SATURDAY...VFR. CHANCE TSRA.
SUNDAY...VFR. CHANCE TSRA EARLY.
MONDAY...VFR. SLIGHT CHANCE TSRA.
TUESDAY...VFR. SLIGHT CHANCE TSRA.
WEDNESDAY...VFR. WX NIL.
KREIN
&&
.MARINE...
310 AM CDT
A LARGE AREA OF HIGH PRESSURE CENTERED OVER THE SOUTHERN
APPALACHIANS WILL CONTINUE TO SLOWLY DRIFT SOUTHEAST TODAY. LOW
PRESSURE WILL MOVE FROM MANITOBA NORTHEASTWARD TO HUDSON BAY
WHILE DRAGGING A COLD FRONT THROUGH THE UPPER MIDWEST AND THE
WESTERN GREAT LAKES REGION. WITH THE FRONT CONTINUING OFF TO THE
EAST THURSDAY NIGHT...A WEAK RIDGE OF HIGH PRESSURE WILL SPREAD
FROM THE NORTHERN PLAINS INTO THE GREAT LAKES. LOW PRESSURE OF
WILL MOVE FROM THE CENTRAL PLAINS INTO THE WESTERN GREAT LAKES
SATURDAY AND SATURDAY NIGHT BEFORE FILLING. ANOTHER COLD FRONT
WILL PUSH SOUTHEAST THROUGH THE UPPER GREAT LAKES SUNDAY NIGHT.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...HEAT ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-
ILZ032-ILZ033-ILZ039...NOON THURSDAY TO 8 PM THURSDAY.
IN...HEAT ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019...NOON
THURSDAY TO 8 PM THURSDAY.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
537 AM CDT THU JUN 28 2012
.DISCUSSION...
527 AM CDT
HAVE UPDATED FORECAST TO INCLUDE SLIGHT CHANCE MENTION OF
SHRA/TSRA FOR PARTS OF NORTH CENTRAL IL THROUGH MID-MORNING.
AREA OF ACCAS HAD DEVELOPED ACROSS PORTIONS OF CENTRAL AND EASTERN
IA EARLY THIS MORNING...IN REGION FAIRLY STRONG LOW-MID LEVEL
THETA-E ADVECTION ASSOCIATED WITH A SHORT WAVE TROUGH MOVING INTO
THE MID/UPPER MS VALLEY. SLATER IA PROFILER PLOT INDICATES WINDS
IN THE 0.5-3.0 KM LAYER HAVE INCREASED TO 50-60 KTS OVER THE PAST
FEW HOURS...WITH HIGH-BASED RADAR RETURNS DEVELOPING WITHIN
SOUTHERN PERIPHERY OF 2000-3000 J/KG MUCAPE AXIS. ASOS/AWOS SITES
ACROSS EASTERN IA REPORTING CLOUD BASES GENERALLY IN THE
9000-15000 FT RANGE...AND CEDAR RAPIDS RECENTLY REPORTED TSRA WITH
CLOUD BASES AT 11000 FT!
09Z RAP GUIDANCE INDICATES A GRADUAL DECREASE IN 850-700 MB
THETA-E ADVECTION OVER NORTHERN IL THROUGH MID-MORNING...WITH
RECENT RUNS OF THE HRRR ALSO INDICATING DECREASING CONVECTIVE
REFLECTIVITY SIGNATURES ACROSS NORTH CENTRAL IL BY THAT TIME. 06Z
WRF-NAM ISENTROPIC PROGS...ON THE 325K SURFACE...ALSO INDICATES
CONDENSATION PRESSURE DEFICITS SOMEWHAT HIGHER THAN CURRENTLY OVER
EASTERN IA. THUS AT THIS TIME HAVE ADDED SOME SLIGHT CHANCE POPS
BASICALLY NORTH OF A STERLING-BELVIDERE LINE THROUGH 16Z OR SO...
AND WILL HOPE THAT DISSIPATION TREND IN GUIDANCE OCCURS.
RATZER
&&
.PREV DISCUSSION...
400 AM CDT
FORECAST CONCERNS REMAIN FOCUSED ON TRIPLE DIGIT HEAT FOR PORTIONS
OF THE FORECAST AREA TODAY...THEN SHIFT TO PERSISTENT BUT OVERALL
LOW PROBABILITIES OF PERIODIC ROUNDS OF THUNDERSTORMS THROUGH THE
WEEKEND AS COLD FRONT WHICH SAGS ACROSS AREA THIS AFTERNOON STALLS
ACROSS THE SOUTHERN CWA OR JUST OFF TO THE SOUTH TONIGHT.
UPPER RIDGE AXIS WAS ANALYZED ACROSS THE MID-MISSISSIPPI VALLEY AND
WESTERN GREAT LAKES REGION PER 00Z RAOB DATA. OVERNIGHT GOES WATER
VAPOR IMAGERY DEPICTS STRONG UPPER TROUGH SPREADING EAST ACROSS
MANITOBA AND WESTERN ONTARIO HOWEVER...WITH HEIGHT FALLS ALREADY
WORKING TO FLATTEN THE UPPER RIDGE ACROSS THE UPPER MIDWEST. THUS
THE UPPER RIDGE IS BEING SQUASHED SOUTHWARD TODAY ACROSS THE LOWER
MISSOURI AND LOWER OHIO VALLEYS AS FLOW BECOMES MORE ZONAL. AS THIS
OCCURS...LOW LEVEL THERMAL RIDGE OF +30-35 C TEMPS IN THE 925-850 MB
LAYER WILL ALSO BE SUPPRESSED SOUTH A BIT ACROSS SOUTHERN CWA AND
CENTRAL IL/IND AS HAS BEEN THE TREND OF GUIDANCE OVER THE PAST FEW
DAYS. THAT/S NOT TO SAY IT WONT BE HOT ACROSS THE WFO LOT CWA TODAY.
LOW LEVEL THERMAL PROGS CONTINUE TO SUPPORT AFTERNOON MAX TEMPS
RANGING FROM THE UPPER 90S NEAR THE IL/WI BORDER...TO THE 100-105
DEGREE RANGE ALONG/SOUTH OF THE I-80 CORRIDOR. CHICAGO MAY
OFFICIALLY HIT 100...THOUGH COMPLICATING FACTORS INCLUDING SLIGHTLY
FASTER COLD FRONTAL TIMING AND SHIFTING OF WINDS OFF OF LAKE
MICHIGAN BEHIND FROPA. THIS WILL LIKELY ALLOW TEMPS TO FALL BACK
INTO THE 80S THROUGH LATE AFTERNOON AT THE LAKE SHORE WHILE AREAS
FARTHER WEST/SOUTH CONTINUE TO BAKE AT NEARLY 100 DEGREES. SURFACE
DEW POINT TEMPS HAVE RISEN INTO THE MID/UPPER 60S ACROSS PARTS OF
WESTERN IL/SOUTHWEST WI AHEAD OF THE FRONT OVERNIGHT...AND DEW POINT
TEMPS WILL CONTINUE TO INCREASE AS LOW LEVEL MOISTURE POOLS WITHIN
THE FRONTAL ZONE TODAY. WHILE GUIDANCE DEW POINTS IN THE 75-80
DEGREE RANGE ARE LIKELY OVER-FORECAST...AFTERNOON DEWS SHOULD RANGE
FROM THE LOW-MID 60S OVER THE FAR SOUTHEAST...TO THE UPPER 60S TO
AROUND 70 ALONG THE IMMEDIATE FRONTAL ZONE. COUPLED WITH THE AIR
TEMPS MENTIONED ABOVE THIS YIELDS PEAK HEAT INDEX VALUES IN THE
105-110 RANGE...SUPPORTING NO CHANGES TO ONGOING HEAT ADVISORY.
COULD BE A LITTLE IFFY RIGHT ALONG THE LAKE MICHIGAN SHORE AS NOTED
ABOVE...THOUGH HAVE NO PLANS TO PULL HEADLINE AS HEAT INDEX VALUES
SHOULD REACH/EXCEED 100 NEARLY ALL LOCATIONS PRIOR TO FROPA/ONSHORE
WINDS THIS AFTERNOON. TEMPS MAY APPROACH CHICAGO RECORD HIGH OF 101
DEGREES...THOUGH ROCKFORDS 103 IS PROBABLY SAFE TODAY.
AS NOTED ABOVE...FRONT SAGS ACROSS CWA TODAY WITH LOW LEVEL MOISTURE
POOLING DEW POINT TEMPS NEAR 70 DEGREES WITHING THE FRONTAL ZONE.
WHILE SEVERAL MINOR AMPLITUDE SHORT WAVES ARE NOTED LINED UP
INCREASINGLY ZONAL MID/UPPER FLOW...FORECAST SOUNDINGS INDICATE
SUBSTANTIAL CAPPING INITIALLY WHICH ONLY PARTIALLY ERODES THROUGH
THE LATE AFTERNOON HOURS. SIGNIFICANT MLCAPE DOES EXIST IF LOW LEVEL
CONVERGENCE ASSOCIATED WITH FRONTAL BOUNDARY OR COMBINED FRONT AND
LAKE BREEZE BOUNDARY...ON THE ORDER OF 3500-4000 J/KG. THE
INCREASING ZONAL MID-LEVEL FLOW ALSO RESULTS IN 35-40 KTS OF 0-6 KM
BULK SHEAR WHICH WOULD INDICATE THAT IF A STORM IS ABLE TO DEVELOP
AND BREAK THROUGH THE CAP...THE THREAT EXISTS OF SEVERE WEATHER IN
THE FORM OF DAMAGING WINDS AND LARGE HAIL. OF COURSE...THE BIG
QUESTION IS WILL ANYTHING BE ABLE TO BUST THROUGH THE CAP! ODDS ARE
RATHER LOW THIS AFTERNOON INTO THIS EVENING...BUT WILL CONTINUE TO
MENTION A 20 PERCENT ISOLATED TS FOR THE OFF CHANCE THAT ONE
DEVELOPS AND CAUSES SOME PROBLEMS.
FRONT CONTINUES TO SAG ACROSS THE CWA THIS EVENING AND EVENTUALLY
BECOMES NEARLY STATIONARY FROM APPROXIMATELY THE IA/MO BORDER INTO
CENTRAL IL AND THE SOUTHERN CWA BORDER...AND REMAINS THERE MUCH OF
THE WEEKEND. WITH A SERIES OF SEVERAL MINOR AMPLITUDE SHORT WAVE
RIPPLES INDICATED BY GUIDANCE...THE POTENTIAL FOR PERIODIC
OCCASIONAL THUNDERSTORM CLUSTERS IS NOT ZERO. THE MOST LIKELY
SCENARIO AS INDICATED BY SEVERAL GUIDANCE SOLUTIONS IS FOR
DEVELOPMENT OF ELEVATED CONVECTION NORTH OF SURFACE BOUNDARY OVER
PARTS OF EASTERN NEBRASKA/WESTERN IOWA WHERE BETTER BACKED LOW LEVEL
FLOW AND ASSOCIATED MOISTURE CONVERGENCE AND THETA-E ADVECTION WILL
EXIST. STORMS WOULD THE LIKELY PROPAGATE EAST ALONG THE ELEVATED
BAROCLINIC ZONE AND MAY AFFECT THE WFO LOT AREA AT TIMES IN
WEAKENING PHASES. HAVE GENERALLY CARRIED LOW CHANCE POPS FOR
THIS...THOUGH SUSPECT THERE WILL BE MANY DRY HOURS THROUGH THE
WEEKEND IN BETWEEN THESE LITTLE MESOSCALE CLUSTERS OF STORMS.
THOUGH THE FRONT WILL BE SOUTH OF MUCH OF THE CWA...TEMPS IN THE
LOW-MID 90S WILL CONTINUE TO BE THE RULE...THOUGH WEAK FLOW WILL
ALLOW LAKE BREEZES TO COOL TEMPS INTO THE 80S ALONG LAKE MICHIGAN.
RATZER
&&
.CLIMATE...
908 PM CDT
...RECORD OR NEAR RECORD HIGHS POSSIBLE FOR THURSDAY JUNE 28TH...
THE CURRENT FORECAST HIGH IS 100 DEGREES FOR CHICAGO-OHARE AND 99 DEGREES
FOR ROCKFORD ON THURSDAY.
RECORD HIGHS FOR THURSDAY JUNE 28TH:
CHICAGO: 101/1971
ROCKFORD:103/1934
ALL-TIME JUNE RECORD HIGHS:
CHICAGO: 104...6/20/1988.
ROCKFORD: 106...6/1/1934.
ALL-TIME RECORD HIGHS:
CHICAGO: 105...7/24/1934
ROCKFORD: 112...7/14/1936
MDB/JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 09Z...
* FROPA TIMING THURSDAY AFTERNOON AND PRECIP CHANCES ALONG FRONT.
* POTENTIAL FOR LAKE BREEZE THURSDAY AFTERNOON/EVENING.
KREIN
//DISCUSSION...UPDATED 06Z...
THE MAIN FORECAST CONCERNS DURING THE PERIOD WILL BE THE WIND
FORECAST...IN PARTICULAR THE TIMING OF FRONTAL PASSAGE AND TIMING
OF LAKE BREEZE DEVELOPMENT. A SECONDARY CONCERN WILL BE THE SMALL
CHANCES FOR THUNDERSTORM DEVELOPMENT INVOF THE COLD FRONT.
A DIFFUSE COLD FRONT IS SLOWLY SAGGED SEWD THROUGH THE UPPER
MISSISSIPPI VALLEY AND IS EXPECTED TO MOVE INTO NWRN IL BY AROUND
NOON. AS THE FRONTAL TROUGH APPROACHES THE REGION...THE PRESSURE
GRADIENT ACROSS NRN IL/SRN LAKE MICHIGAN/NRN INDIANA WILL BECOME
RATHER WEAK...FURTHER DECREASING THE CONTRAST OF TEMPERATURES AND
WINDS ACROSS THE BOUNDARY AND EXPECT WINDS TO DECREASE. WITH VERY
WARM CONDITIONS DEVELOPING AHEAD OF THE FRONT...COMBINED WITH THE
DECREASING WINDS...IT SHOULD NOT BE TOO DIFFICULT TO DEVELOP A
LAKE BREEZE WITH THE CONTRAST OF NEAR 100F TEMPERATURES INLAND AND
THE MUCH COOLER LAKE MICHIGAN WATER. AS ALWAYS...THE CONCERN WILL
MORE BE TIMING RATHER THAN THE LIKELIHOOD OF LAKE BREEZE
DEVELOPMENT AND NELY FLOW SETTING UP OVER NERN IL AND NLY FLOW
SETTING UP OVER NWRN IN. AT THIS POINT...WILL TIME THE LAKE BREEZE
PUSHING INLAND AND PAST ORD/MDW IN THE 19-21Z TIMEFRAME.
AS FOR THUNDERSTORM POTENTIAL...THE INCREASING HEAT AND HUMIDITY
WILL LEAD TO A VERY UNSTABLE ENVIRONMENT AHEAD OF THE COLD
FRONT...BUT WARM AIR TRANSPORT UNDER SWLY FLOW ALOFT WILL LEAD TO
STRONG CAPPING AT 7KFT. THIS WILL INHIBIT CONVECTIVE
DEVELOPMENT...THROUGH MUCH OF THE AFTERNOON. MODEL GUIDANCE
SUGGESTS LITTLE WEAKENING TO THE CAP AND SINCE THE FRONTAL
BOUNDARY IS VERY DIFFUSE...WITH WILL NOT BE MUCH LOW LEVEL
FORCING. SO...WHILE CHANCES FOR THUNDERSTORM DEVELOPMENT IS NON-
ZERO...WILL CARRY A DRY FORECAST AND MONITOR THE LOCAL ENVIRONMENT
VERY CLOSELY THROUGH THE AFTERNOON AND EVENING HOURS.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 09Z...
* LOW CONFIDENCE IN THUNDERSTORMS IMPACTING THE TERMINALS THURSDAY
AFTERNOON AND EVENING.
* MEDIUM TO HIGH CONFIDENCE IN WINDS BECOMING NORTHEASTERLY LATER
THURSDAY AFTERNOON...BUT LOWER CONFIDENCE IN THE TIMING.
KREIN
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
FRIDAY THROUGH SUNDAY...VFR. CHANCE OF TSRA.
MONDAY...VFR.
TUESDAY...VFR. SLIGHT CHANCE OF TSRA TUESDAY NIGHT.
KJB
&&
.MARINE...
310 AM CDT
A LARGE AREA OF HIGH PRESSURE CENTERED OVER THE SOUTHERN
APPALACHIANS WILL CONTINUE TO SLOWLY DRIFT SOUTHEAST TODAY. LOW
PRESSURE WILL MOVE FROM MANITOBA NORTHEASTWARD TO HUDSON BAY
WHILE DRAGGING A COLD FRONT THROUGH THE UPPER MIDWEST AND THE
WESTERN GREAT LAKES REGION. WITH THE FRONT CONTINUING OFF TO THE
EAST THURSDAY NIGHT...A WEAK RIDGE OF HIGH PRESSURE WILL SPREAD
FROM THE NORTHERN PLAINS INTO THE GREAT LAKES. LOW PRESSURE OF
WILL MOVE FROM THE CENTRAL PLAINS INTO THE WESTERN GREAT LAKES
SATURDAY AND SATURDAY NIGHT BEFORE FILLING. ANOTHER COLD FRONT
WILL PUSH SOUTHEAST THROUGH THE UPPER GREAT LAKES SUNDAY NIGHT.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...HEAT ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-
ILZ032-ILZ033-ILZ039...NOON THURSDAY TO 8 PM THURSDAY.
IN...HEAT ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019...NOON
THURSDAY TO 8 PM THURSDAY.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
403 PM EDT THU JUN 28 2012
.SHORT TERM...
TONIGHT THROUGH FRIDAY NIGHT. CONT TO FAVOR CAUTIONARY APPROACH WRT
POTNL CONVECTIVE DEVELOPMENT IN SHORT TERM FOR CWA. DESPITE INCSRG
INSTABILITY THIS AFT/EVE AS SFC DPS BEGIN TO POOL TO NEAR 70F ACRS
NWRN CWA THIS AFTN...FAVORED INITIATION REGIONS EXIST BOTH
DOWN/UPSTREAM. STILL MODELS SPCLY GFS CONTS TO FAIL TO CAPTURE
SIGNIFICANCE OF DRY GROUND/D3 DROUGHT CONDS THAT HAVE EMERGED ACRS
NRN IN AND CONT TO SHAVE SVRL DEGREES DOWNWARD. THIS AM NOTED
SHORTWAVE/700H JETLET GENERATED XTRMLY HIGH ELEVATED CONVECTION
INVOF KCID...THIS FEATURE TO PUSH INTO NWRN OH THIS EVE WITH CAP
SLOWLY DERIDED PER SPC RAP IN TANDEM WITH CONCEPTUAL MODEL
EXPECTATIONS...THOUGH EAST OF CWA. WELL WEST OF CWA WITHIN DCPVA
ZONE AMID OVERLAP ALONG NRN EDGE OF STRONGER/LESS INHIBITED
INSTABILITY AXIS FM NWRN IL WWD INTO SERN NE WITH MLCAPE 4000-5000
J/KG AND SRN PERIPHERY OF HIR DEEP LYR /0-6KM/ SHEAR OF 40-55KTS TO
LKLY SUPPORT MULTIPLE MCS DEVELOPMENT ACRS PLAINS INTO INTO IA/MO
NEAR/AFTER SUNSET AS SRLY 925-850MB JET STRENGTHENS/NOSES ACRS CNTL
KS. ADDNL/CONTD CONVECTIVE SUPPORT ACRS IA/MO THROUGH DAYBREAK AS
ERN PERIPHERY OF LLJ VEERS. LACK OF ULVL JET SUPPORT ACRS CWA
FURTHER POINTS TO LIKEN DRY BEGETS DRY. FLATTENED RIDGE TO ALLOW
SHALLOW SFC FNTL ZONE TO SLIDE SEWD QUIETLY THROUGH CWA...WITH ZONE
OF RICH 0-0.5KM THETA-E LAID OUT FM NRN IL INTO CNTL IN ON FRIDAY.
SLIGHT CHC FOR LATE AFTN/EVE CONVECTION INITIATION RELEGATED TO
ONLY SWRN CWA INVOF BNDRY WITH INCRSD UPPER LVL DIVERGENCE AS NRN
PLAINS UPR JETLET MOVES INTO SERN LWR MI/LWR GRTLKS COINCIDENT
WITH GREATEST INSTABILITY.
&&
.LONG TERM... / SATURDAY THROUGH THURSDAY /
WEST TO NORTHWEST FLOW ALOFT IS EXPECTED TO PERSIST THIS WEEKEND
INTO EARLY NEXT WEEK OVERTOP A FLATTENED UPPER LEVEL RIDGE. THE
POLAR JET WILL GENERALLY REMAIN WELL NORTH AND EAST OF THE REGION
STILL ALLOWING HIGHS TO REACH THE 90S EACH DAY AS 850 HPA TEMPS
GENERALLY STAY AOA 20C...WITH MID LVL CLOUD DEBRIS FROM UPSTREAM
CONVECTION BEING THE ONLY HOPE FOR COOLER TEMPS. AT THE SURFACE A
DIFFUSE/SHALLOW QUASI-STATIONARY BOUNDARY IS FCST TO HANG AROUND THE
NORTHERN OHIO VALLEY WWD TOWARDS THE CENTRAL PLAINS THROUGH
SUNDAY...POSSIBLY MIXING NORTH OF THE AREA OR WASHING OUT BY MONDAY.
WILL LIKELY SEE CONVECTIVE COMPLEXES FIRE IN THE VICINITY OF THIS
BOUNDARY FRIDAY AND SATURDAY NIGHT NEAR IOWA AS SEVERAL LOW
AMPLITUDE (CONVECTIVELY ENHANCED/INDUCED) SHORTWAVES CREST THE
REBUILDING CENTRAL PLAINS UPPER RIDGE. THESE POTENTIAL MCS COMPLEXES
WILL LIKELY WEAKEN WITH EWD PROGRESSION AS THEY OUTRUN BETTER LOW
LVL FORCING (LLJ) AND DRY OUT OVER POORLY MODELED DRY LOW LEVELS
(MODELS OVERDOING BOUNDARY LAYER/SOIL MOISTURE WITH CLIMO BIAS AND
THEREFORE INSTABILITY/SFC DEWPOINTS/ETC). WITH THIS CONFIDENCE FOR
ANY MEASURABLE RAINFALL REMAINS LOW DURING THIS TIME AS THINK THE
BEST CASE SCENARIO IS FOR A MCV TO BRING HIGH BASED SHOWERS WITH
LITTLE/NO DROUGHT RELIEF. ALSO EXPECT AFTERNOON CONVECTIVE
RE-DEVELOPMENT TO BE ISOLATED AT BEST ALONG ANY COMPOSITE OUTFLOW
BOUNDARIES. AS A RESULT OPTED TO KEEP POPS IN THE 10-20 PERCENT
RANGE (MAINLY NO WX MENTION) AS WOULD EXPECT MOST OF THIS PERIOD TO
BE DRY IN THIS ONGOING D1-D3 DROUGHT. THE ROCKIES/CENTRAL ROCKIES
UPPER RIDGE WILL BUILD NWD TOWARDS THE UPPER MIDWEST NEXT WEEK WITH
HEIGHT RISES/WARMING AND DRY CONDITIONS ANTICIPATED LOCALLY. TEMPS
COULD MAKE ANOTHER RUN AT 100F BY DAYS 6/7.
&&
.AVIATION... /18 UTC TAFS/
DIFFICULT FCST THIS ITERATION...MAINTAIN PRIMARILY VFR TAFS WITH
POINT CONVECTIVE CHCS REMAINING BLO THRESHOLD FOR INCLUSION AS MLCIN
RMNS STOIC ACRS NRN IN THIS AFTN. HEIGHTENED CHCS FOR INITIATION
EXIST BOTH UP/DOWNSTREAM OF RGN LATER THIS EVENING...POTNLY
PROVIDING DRY FROPA LATER TONIGHT. CONVERGENCE OF NEAR SFC
HYGROSCOPIC POLLUTANTS AND SFC DP POOLING TO NEAR 70 MAY PROVIDE
IMPETUS FOR SUNRISE BR DVLPMNT. ZONE OF HIR SFC BASED INSTABILITY
THEREAFTER RELEGATED FM ERN IA INTO CNTL IN MIDDAY FRIDAY/FRIDAY
AFTN...TAKING FOCUS AREA FOR REDEVELOPMENT SOUTH OF TAF SITES.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...EXCESSIVE HEAT WARNING UNTIL 8 PM EDT /7 PM CDT/ THIS EVENING
FOR INZ008-009-012>018-020-022>027-032>034.
RED FLAG WARNING UNTIL 8 PM EDT /7 PM CDT/ THIS EVENING FOR
INZ005>009-012>018-020-022>027-032>034.
HEAT ADVISORY UNTIL 8 PM EDT /7 PM CDT/ THIS EVENING FOR
INZ003>007.
RIP CURRENT RISK UNTIL 5 PM CDT THIS AFTERNOON FOR INZ003.
MI...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR MIZ077>081.
RIP CURRENT RISK UNTIL 6 PM EDT THIS EVENING FOR MIZ077.
OH...EXCESSIVE HEAT WARNING UNTIL 8 PM EDT THIS EVENING FOR OHZ004-
005-015-016-024-025.
RED FLAG WARNING UNTIL 8 PM EDT THIS EVENING FOR OHZ001-002-004-
005-015-016-024-025.
HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR OHZ001-002.
LM...NONE.
&&
$$
SHORT TERM...MURPHY
LONG TERM...STEINWEDEL
AVIATION...MURPHY
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
649 PM CDT FRI JUN 29 2012
.AVIATION...
MESOSCALE CONVECTIVE VORTEX OVER EAST CENTRAL IOWA AT 00Z IS
SLOWLY DRIFTING NORTHEAST. WINDS UNDERNEATH THE VORTEX ARE STILL
GUSTING BETWEEN 50 AND 60 MPH AND SHOULD PERSIST FOR ANOTHER HOUR
OR TWO. STORMS ARE FIRING UP BEHIND THIS CIRCULATION AND WILL BE
THE OTHER ISSUE THIS EVENING. TAF SITES AFFECTED BY THIS COMPLEX
INCLUDE CID...DBQ AND MLI WITH MOST OF THE ACTION REMAINING NORTH
OF BRL.
WITH OUTFLOW ENHANCED BOUNDARY MOVING SOUTH TOWARD THE IOWA-
MISSOURI BORDER...STORMS COULD REDEVELOP WITH LOW-LEVEL JET
SUPPORT LATER TONIGHT...AND WITH FAVORABLE HEATING AGAIN TOMORROW
AFTERNOON. BUT SINCE DETAILS REMAIN UNCLEAR AND CHANCES RATHER
UNCERTAIN...HAVE DECIDED TO KEEP THUNDER OUT OF THE TAFS FOR LATER
PERIODS UNTIL THE DETAILS CLARIFY. WOLF
&&
.PREV DISCUSSION... /ISSUED 309 PM CDT FRI JUN 29 2012/
SYNOPSIS...
12Z UA ANALYSIS HAD AN IMPLIED 850MB WARM FRONT RUNNING FROM
NORTHERN NEBRASKA INTO NORTHEAST MISSOURI. MOISTURE WAS POOLING
NORTH OF THIS BOUNDARY ACROSS IOWA AND ILLINOIS WITH DEW POINTS IN
THE MID TEENS TO LOWER 20S. SATELLITE IMAGERY THROUGH EARLY
AFTERNOON HAS THE MORNING CONVECTION WELL EAST OF THE AREA WITH
NEW CONVECTION DEVELOPING AS A RESULT OF AN MCV IN WESTERN IOWA.
TRENDS IN SATELLITE/RADAR THE PAST FEW HOURS SHOWS CONVECTION
SLOWLY GETTING STRONGER.
18Z SFC ANALYSIS IS EXTREMELY NOISY WITH NUMEROUS MESOSCALE
FEATURES. A WAKE LOW WAS NEAR KRFD WITH A MESO LOW OVER THE
NORTHWEST PARTS OF THE KDSM METRO AREA. OUTFLOW BOUNDARIES WERE
ACROSS THE SOUTHERN CWFA WITH ANOTHER WEAK BOUNDARY MOVING SOUTH
FROM THE KDSM LOW TO NEAR KTVK. DEW POINTS WERE GENERALLY IN THE
60S WITH POCKETS OF 70 DEW POINTS IN WESTERN IOWA AND ALONG THE
OUTFLOW BOUNDARY IN THE SOUTHERN CWFA.
SHORT TERM...TONIGHT AND SATURDAY
NONLINEAR PROCESSES ARE DOMINATING THE SENSIBLE WX. AS SUCH
ANALYSIS OF TRENDS AND CONCEPTUAL MODELS WERE USED HEAVILY FOR THE
IMMEDIATE TERM. INPUT FROM RAP MODEL TRENDS USING THE MCS AND
LIFT TOOLS HELPED A LITTLE TOO.
TRENDS FROM THE RAP MODEL SUGGEST CONVECTION WILL CONTINUE TO
DEVELOP AND STRENGTHEN ACROSS SOUTHERN IOWA THE NEXT SEVERAL
HOURS. MCS TOOL SUGGESTS THE COLLISION OF THE OUTFLOW BOUNDARY WITH
THE APPROACHING BOUNDARY FROM THE MESO LOW WILL INITIATE
CONVECTION THAT MOVES INTO THE CWFA LATE THIS AFTERNOON. SAID
CONVECTION SHOULD EVOLVE INTO A LINEAR MCS THAT MOVES EAST AND
SOUTH DURING THE EVENING HOURS.
THE POTENTIAL ENERGY BUILT UP IN THE CLEAR AREAS ACROSS SOUTHERN
IOWA SHOULD ALLOW THE STORMS TO BECOME QUITE STRONG. SEVERE STORMS
MAY BE POSSIBLE LATE THIS AFTERNOON AND EVENING WITH THE NEW
CONVECTION. TRENDS OVER THE NEXT FEW HOURS WILL BE THE KEY TO WHAT
HAPPENS.
LATER TONIGHT...THE MCS AND LIFT TOOLS ARE SUGGESTING YET ANOTHER
MCS WILL DEVELOP OUT WEST AND MOVE INTO THE AREA. EFFECTIVE
BOUNDARIES LEFT OVER FROM THE EARLIER CONVECTION SHOULD DICTATE
WHERE THIS CONVECTION GOES. REGARDLESS...THIS CONVECTION SHOULD
BE ANOTHER LINEAR MCS. IF THIS MCS CAN BECOME SURFACE BASED...THE
DIFFERENTIAL THETA E SUGGESTED IN THE MODELS WOULD SUPPORT SEVERE
STORMS WITH WIND...POSSIBLY EXTREME...BEING THE PRIMARY THREAT.
THIS SECOND MCS SHOULD BE IN A DECAYING MODE OR EXITING THE CWFA
SATURDAY MORNING. COLD POOLS LEFT OVER FROM THIS MCS ALONG WITH
OUTFLOW BOUNDARIES WOULD THEN PROVIDE THE FOCUS FOR NEW CONVECTION
SATURDAY AFTERNOON.
AS FOR THE HEAT HEADLINES...THE OUTFLOW BOUNDARY FROM CONVECTION
THIS MORNING HAS HELPED HOLD DOWN TEMPERATURES SOMEWHAT ACROSS THE
SOUTH. FOR NOW WILL CONTINUE WITH THE CURRENT HEADLINES BUT
CONVECTION LATE THIS AFTERNOON/EVENING MAY RESULT IN THE HEAT
ADVISORY BEING CANCELLED FOR MOST IF NOT ALL OF THE AREA. ..08..
LONG TERM...SATURDAY NIGHT THROUGH NEXT FRIDAY...
ABOVE NORMAL TEMPERATURES TO CONTINUE AND HUMID WITH A CHANCE OF
THUNDERSTORMS INTO MONDAY.
OVERVIEW...CONCERNS OF NON-LINEAR CONVECTION AND OUTFLOW BOUNDARIES
AS HAVE OCCURRED TODAY AND DISCUSSED YESTERDAY TO REMAIN A MAJOR
CHALLENGE INTO MONDAY.
INITIALIZATION ADEQUATE WITH VERIFICATION SUGGESTING AN OVERWEIGHT OF
GFS AND NAM-WRF. CONVECTION THIS PM AND TONIGHT WILL IMPACT NEXT
ROUND OF CONVECTION TOMORROW NIGHT INTO SUNDAY AS WELL AS
TEMPERATURES...JUST LIKE TODAY. AGAIN...TIMING AND LOCATION OF
PRECIPITATION WILL BE HARD TO CLARIFY BEYOND 6-12 HOURS AHEAD DUE TO
NON-LINEAR NATURE AND OUTFLOW BOUNDARIES IMPACTING SUBSEQUENT
CONVECTION EVENTS. HIGH TO EXTREME STABILITY IS STILL INDICATED INTO
MONDAY WITH MUCAPES OF 2500 TO 4000+ J/KG...MAX DIFFERENTIAL THETA_E
OF 30C...POSSIBLY MORE AND WBZ 12-14K AGL SUPPORTIVE OF RISK OF
DAMAGING TO VERY DAMAGING STRAIGHT LINE WINDS. THE NEXT COUPLE OF
DAYS MAY SEE REPORTS OF 80+ MPH WINDS NEAR OR IN OUR FORECAST AREA
DUE TO THIS HIGH TO EXTREME INSTABILITY. THIS HAS NOW OCCURRED TODAY
WITH OUR CONVECTION THIS MORNING NOW MOVING EAST INTO NORTHERN
INDIANA AS A BOWING SYSTEM AND IS BECOMING A DERECHO WITH FORT WAYNE
AIRPORT REPORTING MEASURED WIND GUSTS OF 79 KTS...OR 91 MPH.
TEMPERATURES TO STAY ABOVE NORMAL BY 5 TO 10 DEGREES THROUGH NEXT
WEEK.
SATURDAY NIGHT THROUGH SUNDAY...UPPED POPS WITH ANOTHER ROUND OF
CONVECTION SUGGESTED...MAINLY FOR SOUTH 1/2 OF AREA. KEY WILL BE
STRENGTH OF OUTFLOW FROM MCS TONIGHT INTO SATURDAY. NORTH SECTIONS
SHOULD STAY NORTH OF OF COOL POOL OUTFLOW AND SUPPORTIVE OF HIGHS 90
DEGREES AND POSSIBLY ONLY MID 80S FOR LATER SHIFTS ON SUNDAY.
MINS SATURDAY NIGHT MOSTLY 70 TO 75 DEGREES WITH UPPER 60S POSSIBLE
IN HEAVIEST RAINFALL AREAS. HIGH PW/S OF OVER 1.5 UP TO 2 INCHES AND
WEAKER STEERING CONTINUE TO SUPPORT LOCALLY HEAVY RAINFALL OF 2 PLUS
INCHES FOR LATER SHIFTS TO MONITOR AND POSSIBLY 3+ INCHES WITH
TRAINING OF STORMS AND POSSIBLE T-BONE OF WARM ADVECTION WING OF
STORMS AHEAD OF A MAIN BOWING LINE. IF WE GET GOOD LATE PM HEATING
THEN CONCERN REMAINS OF A DECENT AREA OF STRONG WINDS WITH A BOWING
SEGMENT AS MENTIONED ABOVE EARLIER DUE TO HIGH/EXTREME INSTABILITY.
HEAT INDICES IN SOUTHERN SECTIONS MAY PUSH UPPER 90S TO AROUND 100
DEGREES SUNDAY AFTERNOON.
SUNDAY NIGHT AND MONDAY...HAVE LOW CHANCE POPS ATTM...POOR CONFIDENCE
HERE DUE TO EVIDENCE OF WARM FRONT TO PUSH NORTH AND ENOUGH UPPER
SUPPORT FOR ANOTHER MCS THAT SOLUTIONS OFTEN POORLY CAPTURE. LATER
SHIFTS MAY NEED TO AGAIN UP POPS AND ADJUST HI TEMPERATURES DOWN AS
THE CASE THE PREVIOUS 3 DAYS.
MONDAY NIGHT THROUGH FRIDAY...AREA TO REMAIN ON THE EDGE OF OUR
NORMAL MID SUMMER "RING OF FIRE" WITH STRONG UPPER LEVEL RIDING. KEPT
MOSTLY DRY BUT A LOW RISK OF CONVECTION REMAINS THAT MAY PROPAGATE
OR FIRE FOR LATER SHIFTS TO RECONSIDER. MODERATE TO HIGH INSTABILITY
CONTINUE TO SUPPORT A SEVERE STORM POTENTIAL WITH ANY STORMS WITH
AGAIN STRONG STRAIGHT LINE WINDS DUE TO HIGH INSTABILITY. HI
TEMPERATURES MOSTLY 90 TO 95 DEGREES WITH SOME UPPER 90S POSSIBLE IN
SOUTH AND LOWS MOSTLY 70 TO 75 DEGREES AND AFTERNOON HEAT INDICES 95
TO 100 DEGREES SUGGESTED FOR A FEW TO SEVERAL HOURS. EVIDENCE OF A
BREAK IN THE HEAT TO DEVELOP BY THE FOLLOWING WEEKEND.
NICHOLS
AVIATION... /ISSUED 1228 PM CDT FRI JUN 29 2012/
OUTFLOW BOUNDARIES FROM TSRA SHOULD ARRIVE AT KBRL SHORTLY WITH
GUSTY WINDS. OTHER THAN CHANGEABLE WINDS VFR WX SHOULD BE SEEN
THROUGH 00Z/30. MORE TSRA ARE EXPECTED TO DVLP IN CENTRAL IOWA AND
MOVE EAST TO ILLINOIS 21Z/29 TO 03Z/30 CAUSING MVFR CONDITIONS.
POTENTIAL FOR BRIEF IFR CONDITIONS WITH A SEVERE TSRA. VFR
CONDITIONS ARE EXPECTED TO CONTINUE AFT 00Z/30 WITH ANOTHER ROUND
OF TSRA...POSSIBLY SEVERE...AFT 06Z/30. ..08..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...HEAT ADVISORY UNTIL 7 AM CDT SATURDAY FOR DES MOINES-HENRY IA-
JEFFERSON-KEOKUK-LEE-LOUISA-MUSCATINE-VAN BUREN-WASHINGTON.
IL...HEAT ADVISORY UNTIL 7 AM CDT SATURDAY FOR HANCOCK-HENDERSON-
MCDONOUGH-MERCER-WARREN.
MO...HEAT ADVISORY UNTIL 7 AM CDT SATURDAY FOR CLARK-SCOTLAND.
&&
$$
WOLF
AREA FORECAST DISCUSSION
NWS DES MOINES IA
641 PM CDT FRI JUN 29 2012
...UPDATED AVIATION DISCUSSION...
.SHORT TERM.../TONIGHT/
CONVECTIVE TRENDS ARE MAIN FOCUS TONIGHT. CONVECTION IS CURRENTLY
FOCUSED AHEAD OF A UPPER SHORT WAVE/VORTICITY CENTER...A DESPITE
HEAT AND HUMIDITY IN SOUTHERN IOWA IT IS LIKELY ELEVATED IN NATURE
RATHER THAN SURFACE BASED. THIS MAKES IT A LITTLE MORE DIFFICULT TO
PREDICT...BUT STRONGER STORMS SHOULD CONTINUE MOVING RAPIDLY
EASTWARD. MODERATELY UNSTABLE BUT WITHOUT A LOT OF SHEAR...AND
DOWNDRAFT CAPE IS BEST INDICATOR OF POSSIBILITY OF STRONG WIND
GUSTS. AFTER THE LATE AFTERNOON AND EARLY EVENING ROUND OF SCATTERED
ACTIVITY...A SECOND SHORT WAVE OVER THE DAKOTAS DROPS ACROSS
NORTHERN IOWA OVERNIGHT. SCATTERED THUNDERSTORMS ARE POSSIBLE WITH
THIS AS WELL. SEEMS THAT THE HIGHER PROBABILITIES WOULD BE ALONG THE
700 MB GRADIENT AS STORMS ARE EXPECTED TO BE MAINLY ELEVATED AGAIN.
MANY NUMERICAL MODELS BRING CONVECTION MUCH FARTHER SOUTH...POSSIBLY
INTERACTING WITH OUTFLOW FROM CURRENT STORMS...SO BLENDED IN SOME OF
THIS SOLUTION WITH MY THINKING. FINALLY...THE HEAT. LOOKS LIKE
OUTFLOW AND POSSIBLY CONVECTION SHOULD AFFECT ALL OF CURRENT
ADVISORY AREA...DROPPING HEAT INDICES BELOW 75 OVERNIGHT AND
PROVIDING A BRIEF SPELL OF RELIEF. WILL ALLOW ADVISORY TO EXPIRE AT
8 PM AS SCHEDULED...AND ALLOW FOLLOWING SECTIONS TO ADDRESS HEAT
THREATS SATURDAY AND BEYOND.
.LONG TERM.../SATURDAY THROUGH FRIDAY/
LITTLE CHANGE IN THE UPPER RIDGE THROUGH SUNDAY WITH A COUPLE SHORT
WAVES STILL MOVING OVERTOP OF THE SYSTEM AND INTO THE REGION. THE
SURFACE BOUNDARY WILL MEANDER OVER CENTRAL AND SOUTHERN IOWA THROUGH
THE WEEKEND WITH WARM AND HUMID CONDITIONS EXPECTED ALONG AND SOUTH
OF THE BOUNDARY WITH TEMPERATURES IN THE LOW TO MID 90S AND
DEWPOINTS IN THE LOW TO MID 70S. THIS WILL PRODUCE HEAT INDEX VALUES
IN THE 100 TO 105 DEGREE RANGE. THE COMBINATION OF THE BOUNDARY AND
A COUPLE SHORT WAVES MOVING THROUGH...WILL HAVE SOME CLOUDS AROUND
AND ISOLATED TO SCATTERED THUNDERSTORMS AT TIMES.
THE WARM FRONT WILL SURGE BACK TO THE NORTHEAST SUNDAY NIGHT AND
MONDAY AS THE UPPER RIDGE BEGINS TO BUILD BACK INTO THE MIDWEST.
THIS WILL LEAD TO TEMPERATURES RISING EVEN FURTHER AND PRECIPITATION
CHANCES DECREASING WITH THE CAP MOVING OVERHEAD AND THE RING OF FIRE
SHIFTING TO THE NORTH OF THE STATE. TEMPERATURES ARE ANTICIPATED TO
BE IN THE 90S OVER ALL OF CENTRAL IOWA MONDAY AND TUESDAY. THE RIDGE
BUILDS IN FULL FORCE WEDNESDAY THROUGH FRIDAY WITH EXTREME HEAT
BUILDING INTO CENTRAL IOWA. HIGH TEMPERATURES IN THE MID 90S TO
POSSIBLY LOW 100S OVER THE SOUTH. HEAT INDEX VALUES OF 100 TO 110
DEGREES ARE LIKELY.
&&
.AVIATION...30/00Z
OUTFLOW BOUNDARY FROM AFTERNOON CONVECTION DRAPED WEST-EAST OVER
SOUTHERN IOWA WILL MAINLY BRING A WIND SHIFT TO OTM. WEAKER
CONVECTION DIMINISHING NEAR OTM AND SHOULD BE CLEAR OF THE AREA BY
AROUND 02Z. RAP MODEL HAS CONVECTION DEVELOPING ALONG THE BOUNDARY
IN SOUTHERN IOWA LATER THIS EVENING...BUT HAVE LOW CONFIDENCE TO
MENTION TS IN TAFS ATTM. VERY LOW FLOW AT THE SURFACE OVERNIGHT AND
KEPT WITH LIGHT AND VARIABLE WINDS...AND VFR CONDITIONS. MAY SEE
SOME FOG DEVELOP ACROSS NORTHERN IOWA WITH THE LIGHTER FLOW...BUT
HAVE SOME HIGHER CLOUDS STREAMING IN FROM STORMS IN SD.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 8 PM CDT TONIGHT FOR ADAMS-APPANOOSE-CLARKE-
DAVIS-DECATUR-JASPER-LUCAS-MADISON-MAHASKA-MARION-MONROE-POLK-
POWESHIEK-RINGGOLD-TAYLOR-UNION-WAPELLO-WARREN-WAYNE.
&&
$$
SHORT TERM...JUNGBLUTH
LONG TERM...DONAVON
AVIATION...PODRAZIK
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1226 PM CDT THU JUN 28 2012
.AVIATION...
MAINLY VFR WX SHOULD BE SEEN THROUGH 06Z/29 WITH HIGH DENSITY
ALTITUDES POSSIBLE THROUGH 03Z/29. COLD FRONT RUNS FROM ABOUT KMKE TO
KDSM. LOW CLOUDS ARND 2KFT AGL ARE DVLPG RIGHT BEHIND THE FRONT
THAT MAY BRIEFLY CREATE AN MVFR CIG. POTENTIAL IS STILL THERE FOR
VCSH/VCTS AT KDBQ WITH VIRGA BUT WAS NOT INCLUDED IN THE 18Z TAFS
DUE TO LOW PROBABILITY. AFT 06Z/29 THE MODELS ARE HIGHLY MIXED IN
SOLUTIONS. A TSRA COMPLEX MAY DVLP IN WESTERN IOWA AND MOVE EAST.
THIS SCENARIO WAS LEFT OUT OF THE 18Z TAFS DUE TO UNCERTAINTY. ..08..
&&
.PREV DISCUSSION... /ISSUED 1023 AM CDT THU JUN 28 2012/
UPDATE...
AT 15Z THE COLD FRONT RAN FROM THE NORTH SUBURBS OF KMKE...TO
KEFT...TO THE NORTHERN PARTS OF KCID...TO THE NORTHERN SUBURBS OF
KDSM. DEW POINTS ARE POOLING ALONG AND IMMEDIATELY BEHIND THE
FRONT WITH A FEW MID 70S NOW BEING REPORTED.
THE CURRENT HEAT HEADLINES WILL REMAIN AS IS FOR NOW. HOWEVER...
ACHIEVING HEAT INDEX VALUES OF 100+ IN THE FAR NORTHWEST AND NORTH PARTS
OF THE CWFA MAY NOT OCCUR. INCOMING OBSERVATIONS FOR 15Z INDICATE
A FEW LOCATIONS EITHER AT OR VERY NEAR 100 FOR THE HEAT INDEX
SOUTH OF THE FRONT.
BASED ON WHAT OCCURRED LAST NIGHT AND EARLY THIS MORNING...THERE
IS NO SUCH THING AS A CAP. THE QUESTION NOW IS WHAT WILL OCCUR
LATER THIS AFTERNOON. NONLINEAR PROCESSES WILL BE DOMINATING THE
SENSIBLE WX. THE ONE THING THAT IS KNOWN IS THAT ANY CONVECTION
THAT OCCURS THIS AFTERNOON WILL LIKELY BE ELEVATED AND NOT SURFACE
BASED.
USING THE RAP AS A TREND...THE STRONG VORT MAX OVER NORTHWEST IOWA
WILL MOVE EAST THROUGH THE AFTERNOON. 700MB OMEGAS SHOW STRONG
LIFT DEVELOPING ACROSS THE FAR NORTHERN PARTS OF THE CWFA BY EARLY
AFTERNOON FOLLOWED BY STRONG DOWNWARD MOTION BY LATE IN THE
AFTERNOON. ANOTHER VORT MAX ASSOCIATED WITH THE DEVELOPING ACCAS
FROM KSUX BACK INTO EASTERN NEBRASKA ARRIVES BY MID TO LATE
AFTERNOON. CONVECTION SHOULD DEVELOP AROUND THE LEVEL OF THE LFC
WHICH IS PROGGED TO BE ROUGHLY 700MB.
SO...WILL CONTINUE WITH THE IDEA OF SCHC TO POSSIBLY LOW CHC POPS
OVER ROUGHLY THE NORTHERN QUARTER TO THIRD OF THE CWFA DURING THE
AFTERNOON BEHIND THE FRONT. THE AREA IN QUESTION IS ROUGHLY WHERE
THE ACCAS CURRENTLY IS ON SATELLITE OVER THE NORTH THIRD OF THE
CWFA. ..08..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...HEAT ADVISORY UNTIL 7 AM CDT FRIDAY FOR BENTON-BUCHANAN-CEDAR-
CLINTON-DELAWARE-DES MOINES-DUBUQUE-HENRY IA-IOWA-JACKSON-
JEFFERSON-JOHNSON-JONES-KEOKUK-LEE-LINN-LOUISA-MUSCATINE-
SCOTT-VAN BUREN-WASHINGTON.
IL...HEAT ADVISORY UNTIL 7 AM CDT FRIDAY FOR BUREAU-CARROLL-HANCOCK-
HENDERSON-HENRY IL-JO DAVIESS-MCDONOUGH-MERCER-PUTNAM-ROCK
ISLAND-STEPHENSON-WARREN-WHITESIDE.
MO...HEAT ADVISORY UNTIL 7 AM CDT FRIDAY FOR CLARK-SCOTLAND.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1023 AM CDT THU JUN 28 2012
.UPDATE...
AT 15Z THE COLD FRONT RAN FROM THE NORTH SUBURBS OF KMKE...TO
KEFT...TO THE NORTHERN PARTS OF KCID...TO THE NORTHERN SUBURBS OF
KDSM. DEW POINTS ARE POOLING ALONG AND IMMEDIATELY BEHIND THE
FRONT WITH A FEW MID 70S NOW BEING REPORTED.
THE CURRENT HEAT HEADLINES WILL REMAIN AS IS FOR NOW. HOWEVER...
ACHIEVING HEAT INDEX VALUES OF 100+ IN THE FAR NORTHWEST AND NORTH PARTS
OF THE CWFA MAY NOT OCCUR. INCOMING OBSERVATIONS FOR 15Z INDICATE
A FEW LOCATIONS EITHER AT OR VERY NEAR 100 FOR THE HEAT INDEX
SOUTH OF THE FRONT.
BASED ON WHAT OCCURRED LAST NIGHT AND EARLY THIS MORNING...THERE
IS NO SUCH THING AS A CAP. THE QUESTION NOW IS WHAT WILL OCCUR
LATER THIS AFTERNOON. NONLINEAR PROCESSES WILL BE DOMINATING THE
SENSIBLE WX. THE ONE THING THAT IS KNOWN IS THAT ANY CONVECTION
THAT OCCURS THIS AFTERNOON WILL LIKELY BE ELEVATED AND NOT SURFACE
BASED.
USING THE RAP AS A TREND...THE STRONG VORT MAX OVER NORTHWEST IOWA
WILL MOVE EAST THROUGH THE AFTERNOON. 700MB OMEGAS SHOW STRONG
LIFT DEVELOPING ACROSS THE FAR NORTHERN PARTS OF THE CWFA BY EARLY
AFTERNOON FOLLOWED BY STRONG DOWNWARD MOTION BY LATE IN THE
AFTERNOON. ANOTHER VORT MAX ASSOCIATED WITH THE DEVELOPING ACCAS
FROM KSUX BACK INTO EASTERN NEBRASKA ARRIVES BY MID TO LATE
AFTERNOON. CONVECTION SHOULD DEVELOP AROUND THE LEVEL OF THE LFC
WHICH IS PROGGED TO BE ROUGHLY 700MB.
SO...WILL CONTINUE WITH THE IDEA OF SCHC TO POSSIBLY LOW CHC POPS
OVER ROUGHLY THE NORTHERN QUARTER TO THIRD OF THE CWFA DURING THE
AFTERNOON BEHIND THE FRONT. THE AREA IN QUESTION IS ROUGHLY WHERE
THE ACCAS CURRENTLY IS ON SATELLITE OVER THE NORTH THIRD OF THE
CWFA. ..08..
&&
.AVIATION...
COLD FRONT RUNNING FROM ROUGHLY KMKE...KEFT...KCID...KDSM AT
15Z/28. WIND SHIFT WITH FRONTAL PASSAGE WILL OCCUR IN THE NEXT FEW
HOURS AT KMLI. VFR WX IS EXPECTED AT KCID/KMLI/KBRL THROUGH 00Z/29
AND LIKELY 06Z/29. AT KDBQ...VFR WX IS EXPECTED BUT THERE WILL BE
A POTENTIAL FOR VCSH OR VCTS WITH VIRGA. CLOUD BASES SHOULD BE
4KFT OR HIGHER. IF CONVECTION WOULD IMPACT KDBQ BRIEF MVFR
CONDITIONS MAY BE SEEN. IF PRECIPITATION HAS TROUBLE REACHING THE
GROUND THEN THERE WOULD BE A POTENTIAL FOR A DRY MICROBURST AT
KDBQ. ..08..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...HEAT ADVISORY UNTIL 7 AM CDT FRIDAY FOR BENTON-BUCHANAN-CEDAR-
CLINTON-DELAWARE-DES MOINES-DUBUQUE-HENRY IA-IOWA-JACKSON-
JEFFERSON-JOHNSON-JONES-KEOKUK-LEE-LINN-LOUISA-MUSCATINE-
SCOTT-VAN BUREN-WASHINGTON.
IL...HEAT ADVISORY UNTIL 7 AM CDT FRIDAY FOR BUREAU-CARROLL-HANCOCK-
HENDERSON-HENRY IL-JO DAVIESS-MCDONOUGH-MERCER-PUTNAM-ROCK
ISLAND-STEPHENSON-WARREN-WHITESIDE.
MO...HEAT ADVISORY UNTIL 7 AM CDT FRIDAY FOR CLARK-SCOTLAND.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
257 PM CDT THU JUN 28 2012
...UPDATE TO LONG TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 1222 PM CDT THU JUN 28 2012
AT 12Z THURSDAY AN UPPER LEVEL JET STREAK EXTENDED FROM EASTERN
WYOMING INTO SOUTHWEST ONTARIO. THE CENTER OF THE 500MB HIGH THIS
MORNING WAS LOCATED ACROSS MISSOURI. UPPER LEVEL RIDGE ACROSS THE
CENTRAL UNITED STATES HAD WEEKEND AS ONE UPPER LEVEL TROUGH MOVES
ACROSS EASTERN NEBRASKA AND WHAT APPEARS TO BE ANOTHER UPPER LEVEL
SYSTEM STARTING TO MOVE INTO WESTERN COLORADO BASED ON 500MB
THERMAL TROUGH AND WATER VAPOR LOOP. AN AREA OF TROPICAL MOISTURE
EXTENDED FROM CENTRAL COLORADO INTO CENTRAL/EASTERN NEBRASKA. WARM
16C 700MB TEMPERATURES WERE LOCATED ACROSS WESTERN KANSAS WITH
700MB TEMPERATURES RANGING FROM 16 TO 17C EXTENDING NORTHEASTWARD
INTO THE GREAT LAKES REGION. 700MB TEMPERATURES OF 17C WERE
OBSERVED AT GREEN BAY WISCONSIN, ALPENA MICHIGAN, AND DETROIT
MICHIGAN. 850MB TEMPERATURES OF THE MID TO UPPER 20S STRETCHED
FROM THE PANHANDLE OF TEXAS INTO IOWA. AT THE SURFACE A SURFACE
BOUNDARY WAS LOCATED ACROSS NORTH CENTRAL AND WEST CENTRAL KANSAS
AT 12Z.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 208 PM CDT THU JUN 28 2012
A WEAK SURFACE BOUNDARY WILL EXTEND ACROSS NORTH CENTRAL AND WEST
CENTRAL KANSAS LATE THIS AFTERNOON AND EARLY THIS EVENING. EXACT
LOCATION OF THIS BOUNDARY DIFFERS SLIGHTLY BETWEEN THE NAM, RAP,
AND HRRR BUT ALL MODELS TEND TO SUPPORT A SMALL CHANCE FOR A FEW HIGH
BASED THUNDERSTORMS NEAR THIS BOUNDARY LATE TODAY. GIVEN THIS
BOUNDARY LOCATION AS OF 19Z AND SOME HINTS OF AFTERNOON CLOUDS
DEVELOPING IN SOUTHEAST COLORADO NEAR THIS BOUNDARY WILL GO AHEAD AND
INSERT A MENTION OF ISOLATED HIGH BASED THUNDERSTORMS IN A FEW
LOCATIONS ACROSS WEST CENTRAL KANSAS...ESPECIALLY NEAR THE
COLORADO BORDER. GIVEN THE FORECAST MODEL SOUNDING PROFILES ANY
STORM THAT DOES DEVELOP MAY BE CAPABLE OF PRODUCING WIND GUSTS UP
TO 40 MPH.
ANOTHER HOT DAY IS IN STORE FOR ALL OF WESTERN KANSAS ON FRIDAY.
BASED ON MODEL SOUNDINGS MIXED LAYER HEIGHT AND 700MB TEMPERATURES AT
00Z SATURDAY PLUS A SUPER SUGGESTS THE PREVIOUS FORECAST WITH
HIGHS OF 105 TO 108 WERE STILL ON TRACK. THIS COMBINED WITH
DEW POINTS FALLING BACK INTO THE LOW TO MID 50S WILL GIVE RISE TO
FEW HOURS OF HEAT INDEX READINGS AROUND 105 DEGREES FOR A FEW
LOCATIONS IN SOUTH CENTRAL AND NORTH CENTRAL KANSAS. AFTERNOON
RELATIVE HUMIDITIES ACROSS ALL OF WESTERN KANSAS IS EXPECTED TO
BOTTOM OUT IN THE 15 TO 20 PERCENT RANGE. AT THIS TIME AM LEANING
TOWARDS ANOTHER HEAT ADVISORY FOR SEVERAL COUNTIES ONCE AGAIN
ALONG AND EAST OF 183 BUT HOLD OFF ON ANY FIRE WEATHER WATCHES OR
WARNINGS. A FEW HIGH BASED AFTERNOON CLOUDS WILL ALSO BE POSSIBLE
ACROSS PORTIONS OF WESTERN KANSAS AGAIN LATE FRIDAY AFTERNOON AS
TEMPERATURES CLIMB TO AROUND 105 DEGREES. INSTABILITY HOWEVER
BASED ON MODEL SOUNDINGS NOT OVERLY IMPRESSIVE. IF A FEW STORMS DO
DEVELOP THEY WILL LIKELY BE ISOLATED AND A LATE DAY/EARLY EVENING
EVENT.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 257 PM CDT THU JUN 28 2012
HOT AND DRY CONDITIONS WILL CONTINUE THROUGH THE EXTENDED PERIOD. BLENDED
THE FORECAST TO THE 12Z ECMWF WHICH KEEPS SOUTHWEST KANSAS DRY AND HOT.
THERE MIGHT BE A SLIGHT COOL DOWN SUNDAY AS 850-700 HPA TEMPERATURES
COOL SLIGHTLY AS A SUBTLE UPPER LEVEL WAVE PASSES TO THE NORTH. OTHERWISE
...THE UPPER LEVEL RIDGE AMPLIFIES THROUGH NEXT WEEK. WILL KEEP MAXES
IN THE 99-102 DEG F RANGE WITH LOWS IN THE 70S DEG F. WITH SUCH WARM
TEMPERATURES ALOFT, NOT EXPECTING ANY STORMS THROUGH THE PERIOD. FORECAST
SOUNDINGS SHOW A WELL MIXED AND DRY ATMOSPHERE EACH DAY SO EVEN IF A
STORM WOULD TO DEVELOP, IT WOULD MOST LIKELY BE VERY ISOLATED WITH ANY
PRECIPITATION EVAPORATING BEFORE REACHING THE GROUND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1222 PM CDT THU JUN 28 2012
MODEL SOUNDINGS INDICATING WHAT MOISTURE THERE IS PRESENT ACROSS
WESTERN AND NORTH CENTRAL KANSAS WILL BE CONFINED ABOVE THE 12000
FT LEVEL LATE TODAY AND EARLY THIS EVENING. AS A RESULT VFR
CONDITIONS ARE EXPECTED OVER THE NEXT 18 TO 24 HOURS.
SOUTH/SOUTHWEST WINDS AT AROUND 15KTS WILL BACK MORE TO THE
SOUTHEAST BY LATE DAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 71 105 75 105 / 0 10 10 10
GCK 71 106 73 103 / 0 10 10 10
EHA 69 104 73 103 / 10 10 10 10
LBL 71 106 74 103 / 0 10 10 10
HYS 74 107 75 105 / 10 10 10 10
P28 74 107 76 105 / 0 10 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 9 PM CDT THIS EVENING FOR KSZ030-031-046-065-
066-079>081-089-090.
HEAT ADVISORY FROM 1 PM TO 9 PM CDT FRIDAY FOR KSZ031-046-065-
066-079>081-089-090.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...BURGERT
LONG TERM...SUGDEN
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
212 PM CDT THU JUN 28 2012
...UPDATED SHORT TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 1222 PM CDT THU JUN 28 2012
AT 12Z THURSDAY AN UPPER LEVEL JET STREAK EXTENDED FROM EASTERN
WYOMING INTO SOUTHWEST ONTARIO. THE CENTER OF THE 500MB HIGH THIS
MORNING WAS LOCATED ACROSS MISSOURI. UPPER LEVEL RIDGE ACROSS THE
CENTRAL UNITED STATES HAD WEEKEND AS ONE UPPER LEVEL TROUGH MOVES
ACROSS EASTERN NEBRASKA AND WHAT APPEARS TO BE ANOTHER UPPER LEVEL
SYSTEM STARTING TO MOVE INTO WESTERN COLORADO BASED ON 500MB
THERMAL TROUGH AND WATER VAPOR LOOP. AN AREA OF TROPICAL MOISTURE
EXTENDED FROM CENTRAL COLORADO INTO CENTRAL/EASTERN NEBRASKA. WARM
16C 700MB TEMPERATURES WERE LOCATED ACROSS WESTERN KANSAS WITH
700MB TEMPERATURES RANGING FROM 16 TO 17C EXTENDING NORTHEASTWARD
INTO THE GREAT LAKES REGION. 700MB TEMPERATURES OF 17C WERE
OBSERVED AT GREEN BAY WISCONSIN, ALPENA MICHIGAN, AND DETROIT
MICHIGAN. 850MB TEMPERATURES OF THE MID TO UPPER 20S STRETCHED
FROM THE PANHANDLE OF TEXAS INTO IOWA. AT THE SURFACE A SURFACE
BOUNDARY WAS LOCATED ACROSS NORTH CENTRAL AND WEST CENTRAL KANSAS
AT 12Z.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 208 PM CDT THU JUN 28 2012
A WEAK SURFACE BOUNDARY WILL EXTEND ACROSS NORTH CENTRAL AND WEST
CENTRAL KANSAS LATE THIS AFTERNOON AND EARLY THIS EVENING. EXACT
LOCATION OF THIS BOUNDARY DIFFERS SLIGHTLY BETWEEN THE NAM, RAP,
AND HRRR BUT ALL MODELS TEND TO SUPPORT A SMALL CHANCE FOR A FEW HIGH
BASED THUNDERSTORMS NEAR THIS BOUNDARY LATE TODAY. GIVEN THIS
BOUNDARY LOCATION AS OF 19Z AND SOME HINTS OF AFTERNOON CLOUDS
DEVELOPING IN SOUTHEAST COLORADO NEAR THIS BOUNDARY WILL GO AHEAD AND
INSERT A MENTION OF ISOLATED HIGH BASED THUNDERSTORMS IN A FEW
LOCATIONS ACROSS WEST CENTRAL KANSAS...ESPECIALLY NEAR THE
COLORADO BORDER. GIVEN THE FORECAST MODEL SOUNDING PROFILES ANY
STORM THAT DOES DEVELOP MAY BE CAPABLE OF PRODUCING WIND GUSTS UP
TO 40 MPH.
ANOTHER HOT DAY IS IN STORE FOR ALL OF WESTERN KANSAS ON FRIDAY.
BASED ON MODEL SOUNDINGS MIXED LAYER HEIGHT AND 700MB TEMPERATURES AT
00Z SATURDAY PLUS A SUPER SUGGESTS THE PREVIOUS FORECAST WITH
HIGHS OF 105 TO 108 WERE STILL ON TRACK. THIS COMBINED WITH
DEW POINTS FALLING BACK INTO THE LOW TO MID 50S WILL GIVE RISE TO
FEW HOURS OF HEAT INDEX READINGS AROUND 105 DEGREES FOR A FEW
LOCATIONS IN SOUTH CENTRAL AND NORTH CENTRAL KANSAS. AFTERNOON
RELATIVE HUMIDITIES ACROSS ALL OF WESTERN KANSAS IS EXPECTED TO
BOTTOM OUT IN THE 15 TO 20 PERCENT RANGE. AT THIS TIME AM LEANING
TOWARDS ANOTHER HEAT ADVISORY FOR SEVERAL COUNTIES ONCE AGAIN
ALONG AND EAST OF 183 BUT HOLD OFF ON ANY FIRE WEATHER WATCHES OR
WARNINGS. A FEW HIGH BASED AFTERNOON CLOUDS WILL ALSO BE POSSIBLE
ACROSS PORTIONS OF WESTERN KANSAS AGAIN LATE FRIDAY AFTERNOON AS
TEMPERATURES CLIMB TO AROUND 105 DEGREES. INSTABILITY HOWEVER
BASED ON MODEL SOUNDINGS NOT OVERLY IMPRESSIVE. IF A FEW STORMS DO
DEVELOP THEY WILL LIKELY BE ISOLATED AND A LATE DAY/EARLY EVENING
EVENT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 351 AM CDT THU JUN 28 2012
THE HOT PATTERN WILL CONTINUE THROUGH THE ENTIRE MEDIUM RANGE
FORECAST PERIOD. FOR FRIDAY, THERE IS LOW CONFIDENCE AT THIS TIME
ON WHETHER OR NOT A HEAT ADVISORY MIGHT BE NEEDED IN THE EASTERN
SECTIONS OF THE FORECAST AREA FOR FRIDAY AFTERNOON. SOME SUPPORT
EXISTS IN THE VARIOUS MODELS AND MOS OUTPUT FOR MAXIMUM TEMPERATURES
TO OCCUR A FEW DEGREES LOWER FRIDAY AFTERNOON THAN THE LAST COUPLE
OF VERY HOT DAYS. LITTLE CHANGE IN THE SURFACE MOISTURE AREAL
DISTRIBUTION IS EXPECTED HOWEVER. DEW POINTS WILL STILL REMAIN IN
THE UPPER 50S ACROSS CENTRAL KANSAS FOR SEVERAL DAYS, AS NO SYNOPTIC
EVENT IS EXPECTED TO ALTER THE SURFACE PATTERN. AS A RESULT, IT IS
STILL PLAUSIBLE FOR HEAT INDICES TO REACH 105 DEGREES OR HIGHER
ALONG A HAYS TO COLDWATER LINE AND EASTWARD. THE INTENSE RIDGE THAT
HAS BEEN CENTERED ACROSS KANSAS PROVIDING VERY STRONG SUBSIDENCE
RECENTLY DOES APPEAR TO BECOME FLATTENED BY THE MODELS OVER THE
COMING DAYS, BEGINNING AROUND FRIDAY INTO SATURDAY. THE MID LEVEL
HIGH NOTED BY THE 594-596 DM ISOHYPSE WILL HAVE SHIFTED TOWARD THE
SOUTHERN MISSISSIPPI VALLEY AND EASTWARD BY THAT TIME. THE NAM AND
GFS SHOW A VERY WEAK/COMPACT SHORTWAVE MOVING THROUGH THE CENTRAL
HIGH PLAINS LATE FRIDAY AS WELL. SOUTHWEST KANSAS SHOULD BE UNDER
THE INFLUENCE OF A VERY WARM AND RELATIVELY DRY ATMOSPHERE. ANY
THUNDERSTORMS ASSOCIATED WITH LIFT FROM THIS FEATURE WOULD PROBABLY
BE VERY HIGH BASED, WITH PRIMARILY A GUSTY WIND THREAT OR POSSIBLE
HEAT BURSTS FRIDAY EVENING. THE NAM DOES PRODUCE CONVECTION
ASSOCIATED WITH A DRYLINE FEATURE AT THIS TIME FROM AROUND DODGE
CITY TOWARD LIBERAL AND ELKHART FRIDAY AFTERNOON, WHICH OTHER MODELS
DON`T SEEM TO SUPPORT. IT IS MOST PLAUSIBLE TO HAVE ISOLATED TO
WIDELY SCATTERED HIGH BASED THUNDERSTORMS FRIDAY EVENING, AND LIKELY
LIMITED TO WEST CENTRAL KANSAS, PROBABLY ROUGHLY NORTHWEST OF A HAYS
TO ELKHART LINE.
THE REMAINDER OF THE EXTENDED PERIOD APPEARS TO REMAIN VERY WARM TO
HOT, BUT BECOMING LESS HOT TOWARD THE WEEKEND AS THE RIDGE REMAINS
FAIRLY BROAD OR RELATIVELY FLAT ACROSS THE NORTHERN PLAINS. THE NAM
INDICATES A REPEAT OF POTENTIAL HIGH BASED THUNDERSTORMS AGAIN LATE
SATURDAY AND/OR SATURDAY EVENING, BUT THIS DOESN`T SEEM AS LIKELY
WITHOUT SOME SORT OF UPPER DYNAMIC SUPPORT. 500 MB HEIGHTS WILL
DECREASE TO AROUND 588-590 DM THROUGH THE MIDDLE OF THE WEEK WHILE A
WEAK LEE TROUGHING PATTERN WITH SOUTHERLY SURFACE FLOW PERSISTING OVER
SOUTHWEST KANSAS. HIGH TEMPERATURES ARE LIKELY TO REACH AROUND 100
DEGREES SUNDAY THROUGH WEDNESDAY. THE PATTERN WILL CONTINUE TO
SUPPORT MILD OVERNIGHTS IN THE 70S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1222 PM CDT THU JUN 28 2012
MODEL SOUNDINGS INDICATING WHAT MOISTURE THERE IS PRESENT ACROSS
WESTERN AND NORTH CENTRAL KANSAS WILL BE CONFINED ABOVE THE 12000
FT LEVEL LATE TODAY AND EARLY THIS EVENING. AS A RESULT VFR
CONDITIONS ARE EXPECTED OVER THE NEXT 18 TO 24 HOURS.
SOUTH/SOUTHWEST WINDS AT AROUND 15KTS WILL BACK MORE TO THE
SOUTHEAST BY LATE DAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 73 106 74 105 / 0 10 10 10
GCK 72 107 73 103 / 0 10 10 10
EHA 69 105 72 103 / 0 10 10 10
LBL 71 107 73 103 / 0 10 10 10
HYS 75 108 74 104 / 10 10 20 10
P28 75 108 75 105 / 0 10 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 9 PM CDT THIS EVENING FOR KSZ030-031-046-065-
066-079>081-089-090.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...BURGERT
LONG TERM...RUSSELL
AVIATION...BURGERT
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1035 PM EDT FRI JUN 29 2012
.UPDATE...
ISSUED AT 1035 PM EDT FRI JUN 29 2012
WOW! AFTER SETTING ALL TIME RECORD HIGHS THROUGH THE AREA
TODAY...THOUGH FOR MOST OF THE RECORDS FOR OUR MAIN SITES ONLY DATE
BACK TO THE MID AND LATE 20TH CENTURY...EAST KENTUCKY HAD TO DEAL
WITH A STRONG GUST FRONT BLASTING SOUTH FROM A VERY MEAN DERECHO THAT
ROLLED BY TO THE NORTH. THIS BOUNDARY BROUGHT DAMAGING WIND GUSTS TO
OUR NORTHEAST TIER BEFORE IT WEAKENED AND DISSIPATED OVER THE
SOUTHERN HALF OF THE CWA. UNFORTUNATELY MANY PLACES GOT THE WIND FROM
THE STORMS BUT VERY LITTLE OF THE RAIN THAT COULD HAVE ACCOMPANIED
THEM. THIS EVENT DID BRING SOME SOMEWHAT COOLER AIR TO THE NORTHERN
HALF OF EAST KENTUCKY...THOUGH. ANYWAYS...HAVE ADDED SOME PATCHY
FOG TO THE GRIDS IN PLACES TO THE NORTHEAST THAT MAY HAVE HAVE SEEN
SOME RAIN. ELSEWHERE...ANOTHER MUGGY NIGHT WILL BE ON TAP UNDER
CLEARING SKIES. THIS WILL ALLOW A MINOR TO MODERATE RIDGE TO VALLEY
SPLIT TO DEVELOP...THOUGH ALL LOWS WILL LIKELY END UP IN THE UPPER
60S AND LOWER 70S BY DAWN. HAVE UPDATED THE GRIDS FOR A FLATTER
DIURNAL CURVE THROUGH 2 AM BEFORE THE NORMAL PATTERN TAKES OVER
AGAIN. THE REST OF THE GRIDS REMAINED VIRTUALLY UNTOUCHED FROM THE
LAST UPDATE AND THE ZONES WILL BE LEFT TO STAND AS THEY ARE. AN
UPDATED NPW FOR THE HEAT ADVISORY IS FORTHCOMING. WE WILL SEE WHAT
TOMORROW BRINGS AND WHETHER WE WILL SEE ANY RIDGE RIDERS OR THEIR
ANCILLARY EFFECTS IMPACT OUR AREA...AS THE HEAT ONCE AGAIN DOMINATES.
IN CASE ANYONE MISSED IT...JKL SET AN ALL TIME RECORD HIGH OF 104
TODAY AND LOZ DID THE SAME BY TOPPING OUT AT 105 DEGREES.
UPDATE ISSUED AT 850 PM EDT FRI JUN 29 2012
HAVE UPDATED THE GRIDS TO REMOVE SEVERE WORDING AND BACK OFF POPS AND
SKY COVER IN THE WAKE OF THE EXITING AND DISSIPATING GUST FRONT. HAVE
ALSO ADJUSTED THE TEMPERATURES TO ACCOUNT FOR THE COOL POOL IN THE
WAKE OF THE FRONT...ALONG WITH A TWEAK TO THE DIURNAL CURVE THAT THIS
AFFECTS. NEW ZONES AND HWO WILL BE FORTHCOMING.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 315 PM EDT FRI JUN 29 2012
THE HEAT WAVE WILL CONTINUE THROUGH THE WEEKEND WITH HIGH PRESSURE
STAYING IN PLACE. THE MAIN FORECAST ISSUES ARE TO TRY AND FORECAST
THE SHORT WAVES MOVING AROUND THE PERIPHERY OF THE UPPER HIGH AND
TRY AND DETERMINE IF THEY WILL BE STRONG ENOUGH TO INITIATE
CONVECTION. THE HRRR WAS SHOWING A MCS TYPE OF SYSTEM BARELY
EFFECTING THE AREA NORTH OF THE MOUNTAIN PARKWAY. CONSIDERING THE
SEVERE THUNDERSTORM WATCH IS JUST NORTH OF THE FORECAST
AREA...THOUGHT IT WOULD BE WISE TO INCLUDE SOME THUNDER IN THE
FORECAST. IT IS THE SAME SITUATION FOR TOMORROW...WITH ANOTHER WAVE
MOVING ACROSS THE AREA. THE HEAT IS PRETTY MUCH A SLAM DUNK. WE BROKE THE
THE ALL TIME RECORD FOR JACKSON AT 102 TODAY AND IT MIGHT EVEN GO UP
IN THE NEXT HOUR. WILL HAVE TO WAIT AND SEE. LONDON ALSO HIT 102
TIED THE ALL TIME RECORD FOR THE YEAR.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 315 PM EDT FRI JUN 29 2012
THE EXTENDED FORECAST PERIOD CONTINUES TO FEATURE AND BROAD AND
STRENGTHENING RIDGE OVER MUCH OF THE CONUS STRETCHING FROM THE FRONT
RANGE OF THE ROCKIES AND EAST OVER THE NORTHERN TIER OF THE TN
VALLEY AS WELL AS THE SOUTHEAST. THE MILLION DOLLAR QUESTION...OR
THE FORECAST CHALLENGE OF THE EXTENDED IS...WITH A PROMINENT TROUGH
OVER THE NEW ENGLAND AREA AND A SERIES OF RIDGE RUNNERS DIVING
SOUTHEAST THROUGH THE WESTERN FRINGE OF THE GREAT LAKES AND INTO THE
OHIO VALLEY...WILL AN MCS BE ABLE TO OVERCOME OUR DROUGHT AND MAKE
IT A BIT FURTHER SOUTH INTO THE EASTERN KENTUCKY AREA. AT THIS
POINT...THE MODELS HANDLE THE OVERALL LONG WAVE PATTERN QUITE WELL
BUT JUDGING PREVIOUS RUNS COMPARED HOW THE PATTERN HAS PANNED OUT IN
THE SYNOPTIC AND MESOSCALE...AREAS THAT WOULD HAVE RECEIVED RAIN
ACCORDING TO THE PAST RUNS HAVE NOT COME TO PASS. THIS PROVIDES A
LOWER CONFIDENCE THAT RAINFALL WILL OCCUR IN THE EXTENDED AND GIVEN
THE FACT THAT A STRONG TO DECENT CAP WILL BE IN PLACE OVER MUCH OF
THE AREA. DESPITE BOTH THE EURO AND GFS SHOWING CONVECTION UNDER THE
CAP...WILL LEAN TOWARDS A DRIER FORECAST. WILL RUN THE ALL MODEL
BLEND AND COORDINATE WITH NEIGHBORING OFFICES TO GO ON THE DRY SIDE
OF THE RESULT.
AFTER THE PRODUCING THE MODEL ALL BLEND AND COORDINATION WITH
NEIGHBORING FORECAST OFFICES...DECIDED TO GO WITH A DRY EXTENDED
FORECAST. THE LACK OF CONFIDENCE IN MODELS PRODUCING QPF IN THE
EXTENDED UNDER THE CAP AND THE WORSENING DROUGHT CONDITIONS AIDED IN
THIS DECISION. BETTER INTERROGATION WILL BE NEEDED IN LATER RUNS IF
EASTERN KENTUCKY IS TO GET MEASURABLE RAIN BUT SOME BETTER SUPPORT
ARRIVES THROUGH THE OHIO VALLEY ON THU INTO THU NIGHT THAT MAY PUT
DOWN SOME MUCH NEEDED RAIN BUT AT THIS POINT...FELT A DRY FORECAST
WOULD BE A BETTER REPRESENTATION.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 815 PM EDT FRI JUN 29 2012
THE REMNANTS OF THE DERECHO INDUCED GUST FRONT IS WEAKENING AS IT
SINKS THROUGH THE REMAINDER OF THE FORECAST AREA AND CONDITIONS WILL
RETURN BACK TO QUIET AND SETTLED SHORTLY. ANY MID AND HIGH LEVEL
CLOUDS ASSOCIATED WITH THIS WILL ALSO DISSIPATE THROUGH THE EVENING
HOURS. OTHERWISE...VFR CONDITIONS AND LIGHT WINDS WILL BE THE RULE
THROUGH FRIDAY...THOUGH A STRAY THUNDERSTORM EVENT CANNOT BE ENTIRELY
RULED OUT LATER FRIDAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL MIDNIGHT EDT SATURDAY NIGHT FOR KYZ044-
050>052-058>060-068-069-079-080-083>088-104-106>120.
&&
$$
UPDATE...GREIF
SHORT TERM...JJ
LONG TERM....SHALLENBERGER
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
850 PM EDT FRI JUN 29 2012
.UPDATE...
ISSUED AT 850 PM EDT FRI JUN 29 2012
HAVE UPDATED THE GRIDS TO REMOVE SEVERE WORDING AND BACK OFF POPS AND
SKY COVER IN THE WAKE OF THE EXITING AND DISSIPATING GUST FRONT. HAVE
ALSO ADJUSTED THE TEMPERATURES TO ACCOUNT FOR THE COOL POOL IN THE
WAKE OF THE FRONT...ALONG WITH A TWEAK TO THE DIURNAL CURVE THAT THIS
AFFECTS. NEW ZONES AND HWO WILL BE FORTHCOMING.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 315 PM EDT FRI JUN 29 2012
THE HEAT WAVE WILL CONTINUE THROUGH THE WEEKEND WITH HIGH PRESSURE
STAYING IN PLACE. THE MAIN FORECAST ISSUES ARE TO TRY AND FORECAST
THE SHORT WAVES MOVING AROUND THE PERIPHERY OF THE UPPER HIGH AND
TRY AND DETERMINE IF THEY WILL BE STRONG ENOUGH TO INITIATE
CONVECTION. THE HRRR WAS SHOWING A MCS TYPE OF SYSTEM BARELY
EFFECTING THE AREA NORTH OF THE MOUNTAIN PARKWAY. CONSIDERING THE
SEVERE THUNDERSTORM WATCH IS JUST NORTH OF THE FORECAST
AREA...THOUGHT IT WOULD BE WISE TO INCLUDE SOME THUNDER IN THE
FORECAST. IT IS THE SAME SITUATION FOR TOMORROW...WITH ANOTHER WAVE
MOVING ACROSS THE AREA. THE HEAT IS PRETTY MUCH A SLAM DUNK. WE BROKE THE
THE ALL TIME RECORD FOR JACKSON AT 102 TODAY AND IT MIGHT EVEN GO UP
IN THE NEXT HOUR. WILL HAVE TO WAIT AND SEE. LONDON ALSO HIT 102
TIED THE ALL TIME RECORD FOR THE YEAR.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 315 PM EDT FRI JUN 29 2012
THE EXTENDED FORECAST PERIOD CONTINUES TO FEATURE AND BROAD AND
STRENGTHENING RIDGE OVER MUCH OF THE CONUS STRETCHING FROM THE FRONT
RANGE OF THE ROCKIES AND EAST OVER THE NORTHERN TIER OF THE TN
VALLEY AS WELL AS THE SOUTHEAST. THE MILLION DOLLAR QUESTION...OR
THE FORECAST CHALLENGE OF THE EXTENDED IS...WITH A PROMINENT TROUGH
OVER THE NEW ENGLAND AREA AND A SERIES OF RIDGE RUNNERS DIVING
SOUTHEAST THROUGH THE WESTERN FRINGE OF THE GREAT LAKES AND INTO THE
OHIO VALLEY...WILL AN MCS BE ABLE TO OVERCOME OUR DROUGHT AND MAKE
IT A BIT FURTHER SOUTH INTO THE EASTERN KENTUCKY AREA. AT THIS
POINT...THE MODELS HANDLE THE OVERALL LONG WAVE PATTERN QUITE WELL
BUT JUDGING PREVIOUS RUNS COMPARED HOW THE PATTERN HAS PANNED OUT IN
THE SYNOPTIC AND MESOSCALE...AREAS THAT WOULD HAVE RECEIVED RAIN
ACCORDING TO THE PAST RUNS HAVE NOT COME TO PASS. THIS PROVIDES A
LOWER CONFIDENCE THAT RAINFALL WILL OCCUR IN THE EXTENDED AND GIVEN
THE FACT THAT A STRONG TO DECENT CAP WILL BE IN PLACE OVER MUCH OF
THE AREA. DESPITE BOTH THE EURO AND GFS SHOWING CONVECTION UNDER THE
CAP...WILL LEAN TOWARDS A DRIER FORECAST. WILL RUN THE ALL MODEL
BLEND AND COORDINATE WITH NEIGHBORING OFFICES TO GO ON THE DRY SIDE
OF THE RESULT.
AFTER THE PRODUCING THE MODEL ALL BLEND AND COORDINATION WITH
NEIGHBORING FORECAST OFFICES...DECIDED TO GO WITH A DRY EXTENDED
FORECAST. THE LACK OF CONFIDENCE IN MODELS PRODUCING QPF IN THE
EXTENDED UNDER THE CAP AND THE WORSENING DROUGHT CONDITIONS AIDED IN
THIS DECISION. BETTER INTERROGATION WILL BE NEEDED IN LATER RUNS IF
EASTERN KENTUCKY IS TO GET MEASURABLE RAIN BUT SOME BETTER SUPPORT
ARRIVES THROUGH THE OHIO VALLEY ON THU INTO THU NIGHT THAT MAY PUT
DOWN SOME MUCH NEEDED RAIN BUT AT THIS POINT...FELT A DRY FORECAST
WOULD BE A BETTER REPRESENTATION.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 815 PM EDT FRI JUN 29 2012
THE REMNANTS OF THE DERECHO INDUCED GUST FRONT IS WEAKENING AS IT
SINKS THROUGH THE REMAINDER OF THE FORECAST AREA AND CONDITIONS WILL
RETURN BACK TO QUIET AND SETTLED SHORTLY. ANY MID AND HIGH LEVEL
CLOUDS ASSOCIATED WITH THIS WILL ALSO DISSIPATE THROUGH THE EVENING
HOURS. OTHERWISE...VFR CONDITIONS AND LIGHT WINDS WILL BE THE RULE
THROUGH FRIDAY...THOUGH A STRAY THUNDERSTORM EVENT CANNOT BE ENTIRELY
RULED OUT LATER FRIDAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL MIDNIGHT EDT SATURDAY NIGHT FOR KYZ044-
050>052-058>060-068-069-079-080-083>088-104-106>120.
&&
$$
UPDATE...GREIF
SHORT TERM...JJ
LONG TERM....SHALLENBERGER
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
815 PM EDT FRI JUN 29 2012
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 315 PM EDT FRI JUN 29 2012
THE HEAT WAVE WILL CONTINUE THROUGH THE WEEKEND WITH HIGH PRESSURE
STAYING IN PLACE. THE MAIN FORECAST ISSUES ARE TO TRY AND FORECAST
THE SHORT WAVES MOVING AROUND THE PERIPHERY OF THE UPPER HIGH AND
TRY AND DETERMINE IF THEY WILL BE STRONG ENOUGH TO INITIATE
CONVECTION. THE HRRR WAS SHOWING A MCS TYPE OF SYSTEM BARELY
EFFECTING THE AREA NORTH OF THE MOUNTAIN PARKWAY. CONSIDERING THE
SEVERE THUNDERSTORM WATCH IS JUST NORTH OF THE FORECAST
AREA...THOUGHT IT WOULD BE WISE TO INCLUDE SOME THUNDER IN THE
FORECAST. IT IS THE SAME SITUATION FOR TOMORROW...WITH ANOTHER WAVE
MOVING ACROSS THE AREA. THE HEAT IS PRETTY MUCH A SLAM DUNK. WE BROKE THE
THE ALL TIME RECORD FOR JACKSON AT 102 TODAY AND IT MIGHT EVEN GO UP
IN THE NEXT HOUR. WILL HAVE TO WAIT AND SEE. LONDON ALSO HIT 102
TIED THE ALL TIME RECORD FOR THE YEAR.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 315 PM EDT FRI JUN 29 2012
THE EXTENDED FORECAST PERIOD CONTINUES TO FEATURE AND BROAD AND
STRENGTHENING RIDGE OVER MUCH OF THE CONUS STRETCHING FROM THE FRONT
RANGE OF THE ROCKIES AND EAST OVER THE NORTHERN TIER OF THE TN
VALLEY AS WELL AS THE SOUTHEAST. THE MILLION DOLLAR QUESTION...OR
THE FORECAST CHALLENGE OF THE EXTENDED IS...WITH A PROMINENT TROUGH
OVER THE NEW ENGLAND AREA AND A SERIES OF RIDGE RUNNERS DIVING
SOUTHEAST THROUGH THE WESTERN FRINGE OF THE GREAT LAKES AND INTO THE
OHIO VALLEY...WILL AN MCS BE ABLE TO OVERCOME OUR DROUGHT AND MAKE
IT A BIT FURTHER SOUTH INTO THE EASTERN KENTUCKY AREA. AT THIS
POINT...THE MODELS HANDLE THE OVERALL LONG WAVE PATTERN QUITE WELL
BUT JUDGING PREVIOUS RUNS COMPARED HOW THE PATTERN HAS PANNED OUT IN
THE SYNOPTIC AND MESOSCALE...AREAS THAT WOULD HAVE RECEIVED RAIN
ACCORDING TO THE PAST RUNS HAVE NOT COME TO PASS. THIS PROVIDES A
LOWER CONFIDENCE THAT RAINFALL WILL OCCUR IN THE EXTENDED AND GIVEN
THE FACT THAT A STRONG TO DECENT CAP WILL BE IN PLACE OVER MUCH OF
THE AREA. DESPITE BOTH THE EURO AND GFS SHOWING CONVECTION UNDER THE
CAP...WILL LEAN TOWARDS A DRIER FORECAST. WILL RUN THE ALL MODEL
BLEND AND COORDINATE WITH NEIGHBORING OFFICES TO GO ON THE DRY SIDE
OF THE RESULT.
AFTER THE PRODUCING THE MODEL ALL BLEND AND COORDINATION WITH
NEIGHBORING FORECAST OFFICES...DECIDED TO GO WITH A DRY EXTENDED
FORECAST. THE LACK OF CONFIDENCE IN MODELS PRODUCING QPF IN THE
EXTENDED UNDER THE CAP AND THE WORSENING DROUGHT CONDITIONS AIDED IN
THIS DECISION. BETTER INTERROGATION WILL BE NEEDED IN LATER RUNS IF
EASTERN KENTUCKY IS TO GET MEASURABLE RAIN BUT SOME BETTER SUPPORT
ARRIVES THROUGH THE OHIO VALLEY ON THU INTO THU NIGHT THAT MAY PUT
DOWN SOME MUCH NEEDED RAIN BUT AT THIS POINT...FELT A DRY FORECAST
WOULD BE A BETTER REPRESENTATION.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 815 PM EDT FRI JUN 29 2012
THE REMNANTS OF THE DERECHO INDUCED GUST FRONT IS WEAKENING AS IT
SINKS THROUGH THE REMAINDER OF THE FORECAST AREA AND CONDITIONS WILL
RETURN BACK TO QUIET AND SETTLED SHORTLY. ANY MID AND HIGH LEVEL
CLOUDS ASSOCIATED WITH THIS WILL ALSO DISSIPATE THROUGH THE EVENING
HOURS. OTHERWISE...VFR CONDITIONS AND LIGHT WINDS WILL BE THE RULE
THROUGH FRIDAY...THOUGH A STRAY THUNDERSTORM EVENT CANNOT BE ENTIRELY
RULED OUT LATER FRIDAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL MIDNIGHT EDT SATURDAY NIGHT FOR KYZ044-
050>052-058>060-068-069-079-080-083>088-104-106>120.
&&
$$
UPDATE...GREIF
SHORT TERM...JJ
LONG TERM....SHALLENBERGER
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
1027 PM EDT FRI JUN 29 2012
.SYNOPSIS...
A COLD FRONT WILL CROSS THE AREA THIS EVENING. WEAK HIGH PRESSURE
WILL MOVE OVER THE AREA ON SATURDAY. ANOTHER COLD FRONT WILL PUSH
THROUGH LATE SATURDAY NIGHT. WEAK LOW PRESSURE WILL KEEP SOMEWHAT
UNSETTLED CONDITIONS OVER THE AREA EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 8 AM SATURDAY MORNING/...
UPDATE...THE LAST OF THE TSMTS HAS PUSHED E OF THE CWA ATTM...SO
HAVE GONE AHEAD AND DROPPED ENHANCED WORDING FOR ALL PARTS OF THE
AREA. MIGHT SEE A LINGERING SHRA ACROSS FAR NRN SOMERSET COUNTY
FOR THE NEXT FEW HRS...BUT OTHER THAN THAT CLEAR SKIES EXPECTED
FOR NEARLY THE REST OF THE CWA. WILL BE SOME VERY HIGH...THIN
CIRRUS FROM DERECHO HEADING ACROSS NRN VIRGINIA AND WRN
MARYLAND...BUT THIS WILL HAVE LITTLE EFFECT ON THE FCST. LINGERING
LLVL MOISTURE AND RAPID COOLING OF THE BOUNDARY LYR WILL SUPPORT
PATCHY VALLEY FOG OVERNIGHT.
&&
.SHORT TERM /8 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
FAIR AND WARM WEATHER IS EXPECTED ON SATURDAY. ONLY CAVEAT IS
ACROSS THE NORTHERNMOST ZONES WHERE LATE DAY OR EVENING SHOWERS
AND THUNDERSTORMS WILL BE POSSIBLE ONCE AGAIN AS ANOTHER SHORT
WAVE TROUGH SKIMS THE AREA ALONG WITH THE RR QUAD OF AN UPPER
LEVEL JET STREAK. ISOLD STRONG STORM POSSIBLE THERE WITH STRONG
DEEP LAYER SHEAR IN PLACE DESPITE LESSER INSTABILITY THAN TODAY.
CLEARING THEN TAKES PLACE SATURDAY NIGHT.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
LARGE SCALE PATTERN CONTINUES CYCLONIC FLOW ALOFT WHICH RESULTS IN
THE THREAT OF CONVECTIVE SHOWERS AND THUNDERSTORMS WHICH BECOME
ENHANCED WITH THE PASSAGE OF ANY SHORTWAVES. TIMING OF THESE
SHORTWAVES IS VERY DIFFICULT THIS FAR IN ADVANCE. AS A RESULT WILL
NOT GO ABOVE CHANCE POPS AT THIS TIME.
LATEST MODEL RUNS ARE TRENDING TEMPS A LITTLE COOLER FOR
SUNDAY..HAVE NUDGED THEM DOWN ABOUT 5 DEGREES OVER PREVIOUS
FORECAST. IT LOOKS LIKE NEXT WEEKS TEMPERATURES WILL BE SEASONABLY
WARM BUT NOT GETTING INTO THE EXTREME TEMPERATURES THAT MUCH OF
THE EAST WILL SEE.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM...VFR CONDITIONS EXPECTED OUTSIDE OF ANY THUNDERSTORMS
THROUGH THIS EVENING. THEREAFTER...SOME LOCAL FOG/MIST IS LIKELY
AT NORMALLY PRONE TERMINALS. VFR FOR SATURDAY AND SATURDAY NIGHT.
LONG TERM...MAINLY MVFR CONDITIONS WITH LOCALIZED IFR CONDITIONS
IN ANY SCATTERED THUNDERSTORMS.
&&
.MARINE...
SHORT TERM...SCA FOR MID COAST OF MAINE OUTSIDE OF THE BAYS FOR
TONIGHT FOR SEAS BUILDING TO AROUND 5 FT.
LONG TERM...WINDS AND WAVES BELOW SCA LEVELS THIS PERIOD.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT SATURDAY FOR ANZ150-152.
&&
$$
LEGRO
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
803 PM EDT FRI JUN 29 2012
.SYNOPSIS...
A COLD FRONT WILL CROSS THE AREA THIS EVENING. WEAK HIGH PRESSURE
WILL MOVE OVER THE AREA ON SATURDAY. ANOTHER COLD FRONT WILL PUSH
THROUGH LATE SATURDAY NIGHT. WEAK LOW PRESSURE WILL KEEP SOMEWHAT
UNSETTLED CONDITIONS OVER THE AREA EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 7 AM SATURDAY MORNING/...
UPDATE...SCT TSTMS DEVELOPED AS EXPECTED ACROSS INTERIOR WRN ME.
ATTM...STRONGER TSTMS LINGER ALONG THE MIDCOAST...POSING MAINLY A
LARGE HAIL THREAT WITH ISOLD DMGG WIND GUSTS. JUST AHEAD OF COLD
FNT...STEEP MID LVL LAPSE RATES ARE SUPPORTING LARGE VALUES OF
CAPE WITHIN THE -10 TO -30 C HAIL GROWTH ZONE. FAR NERN KENNEBEC
COUNTY TSTM IS SUPPORTING 67 DBZ ABV 30 KFT...LIKELY LEADING TO
SIGNIFICANT SVR HAIL.
REMAINING TSTMS WILL QUICKLY MOVE EWD AND OUT OF THE CWA IN THE
NEXT COUPLE OF HRS. WILL HAVE TO WATCH FOR SRN QUEBEC TSTMS TO
SNEAK INTO FAR NRN SOMERSET COUNTY BEFORE ALL INSTABILITY IS LOST. THEN
CLEARING AND PATCHY FOG DEVELOPMENT IS EXPECTED TNGT.
PREVIOUS DISCUSSION...A SHORT WAVE TROUGH JUST WEST OF MONTREAL
CONTINUES TO MOVE SOUTHEASTWARD AS OF 1830Z AND WILL MOVE ACROSS
OUR NORTHERN ZONES LATER THIS AFTERNOON AND EARLY EVENING. A COLD
FRONT CONTINUES TO PROGRESS ACROSS VERMONT AND WILL CONTINUE
MOVING EASTWARD. A MOIST AND UNSTABLE AIRMASS HAS DEVELOPED ACROSS
THE REGION THIS AFTERNOON...AND IS COUPLED WITH MODERATE DEEP
LAYER SHEAR.
ISOLATED TO WIDELY SCT THUNDERSTORMS SHOULD DEVELOP ACROSS NRN VT
OR NRN NH BY 20Z...THEN MOVE EASTWARD ACROSS THE WRN ME MOUNTAINS
AND INTO CENTRAL MAINE BY 21-22Z. MORE ISOLATED DEVELOPMENT IS
POSSIBLE FURTHER SOUTH INTO SRN ME...BUT MUCH LESS CONFIDENCE
EXISTS IN THAT POSSIBILITY AS THAT AREA WILL BE MORE REMOVED FROM
THE SHORT WAVE FORCING. GIVEN THE KINEMATIC AND THERMODYNAMIC
ENVIRONMENT...ANY STORMS THAT DO INDEED DEVELOP AND CAN SUSTAIN
THEMSELVES WILL HAVE THE POTENTIAL TO DEVELOP INTO SUPERCELLS
CAPABLE OF PRODUCING LARGE HAIL AND DAMAGING WINDS. A BRIEF
TORNADO CANNOT BE RULED OUT IN CENTRAL MAINE WHERE LOW LEVEL WINDS
WILL BE SLIGHTLY MORE BACKED.
FLASH FLOOD GUIDANCE IS RELATIVELY LOW ACROSS CENTRAL ME DUE TO
RECENT HEAVY RAINFALL. THEREFORE A FLASH FLOOD THREAT IS NON-ZERO
DESPITE STORM MOTIONS LIKELY AROUND OR GREATER THAN 20 KT. ANY
FLASH FLOOD THREAT WOULD BE ENHANCED BY TRAINING OF STORMS.
ANY THUNDERSTORM ACTIVITY SHOULD QUICKLY MOVE OFF TO THE EAST OF
THE CWA BY 00-01Z. THEREAFTER...FOR THE BALANCE OF THE
NIGHT...MOSTLY CLEAR SKIES ARE EXPECTED.
&&
.SHORT TERM /7 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
FAIR AND WARM WEATHER IS EXPECTED ON SATURDAY. ONLY CAVEAT IS
ACROSS THE NORTHERNMOST ZONES WHERE LATE DAY OR EVENING SHOWERS
AND THUNDERSTORMS WILL BE POSSIBLE ONCE AGAIN AS ANOTHER SHORT
WAVE TROUGH SKIMS THE AREA ALONG WITH THE RR QUAD OF AN UPPER
LEVEL JET STREAK. ISOLD STRONG STORM POSSIBLE THERE WITH STRONG
DEEP LAYER SHEAR IN PLACE DESPITE LESSER INSTABILITY THAN TODAY.
CLEARING THEN TAKES PLACE SATURDAY NIGHT.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
LARGE SCALE PATTERN CONTINUES CYCLONIC FLOW ALOFT WHICH RESULTS IN
THE THREAT OF CONVECTIVE SHOWERS AND THUNDERSTORMS WHICH BECOME
ENHANCED WITH THE PASSAGE OF ANY SHORTWAVES. TIMING OF THESE
SHORTWAVES IS VERY DIFFICULT THIS FAR IN ADVANCE. AS A RESULT WILL
NOT GO ABOVE CHANCE POPS AT THIS TIME.
LATEST MODEL RUNS ARE TRENDING TEMPS A LITTLE COOLER FOR
SUNDAY..HAVE NUDGED THEM DOWN ABOUT 5 DEGREES OVER PREVIOUS
FORECAST. IT LOOKS LIKE NEXT WEEKS TEMPERATURES WILL BE SEASONABLY
WARM BUT NOT GETTING INTO THE EXTREME TEMPERATURES THAT MUCH OF
THE EAST WILL SEE.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM...VFR CONDITIONS EXPECTED OUTSIDE OF ANY THUNDERSTORMS
THROUGH THIS EVENING. THEREAFTER...SOME LOCAL FOG/MIST IS LIKELY
AT NORMALLY PRONE TERMINALS. VFR FOR SATURDAY AND SATURDAY NIGHT.
LONG TERM...MAINLY MVFR CONDITIONS WITH LOCALIZED IFR CONDITIONS
IN ANY SCATTERED THUNDERSTORMS.
&&
.MARINE...
SHORT TERM...SCA FOR MID COAST OF MAINE OUTSIDE OF THE BAYS FOR
TONIGHT FOR SEAS BUILDING TO AROUND 5 FT.
LONG TERM...WINDS AND WAVES BELOW SCA LEVELS THIS PERIOD.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT SATURDAY FOR ANZ150-152.
&&
$$
LEGRO
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1153 PM EDT FRI JUN 29 2012
.SYNOPSIS...
ISSUED AT 315 PM EDT FRI JUN 29 2012
VERY WARM WEATHER WILL CONTINUE THROUGH THE WEEKEND INTO EARLY NEXT
WEEK WITH HIGHS MAINLY IN THE UPPER 80S TO LOWER 90S DAILY.
PREDOMINANTLY DRY WEATHER IS EXPECTED THROUGH EARLY TO MID NEXT WEEK
WITH ONLY AN ISOLATED SHOWER OR THUNDERSTORM POSSIBLE.
&&
.UPDATE...
ISSUED AT 804 PM EDT FRI JUN 29 2012
WE ADDED TSRA TO THE SRN HALF OF THE CWA TONIGHT TO ACCOUNT FOR
THE DEVELOPING MCS OVER IOWA. LATEST HRRR SHOWS THE MCS TRACKING
EWD AND CROSS THE SRN 2 ROWS OF THE CWA AFTER 06Z.
&&
.SHORT TERM...(TONIGHT THROUGH SUNDAY NIGHT)
ISSUED AT 315 PM EDT FRI JUN 29 2012
FORECAST CONCERNS INVOLVE DETERMINING MAX TEMPS THIS WEEKEND AND
ASSESSING POTENTIAL FOR ANY ISOLATED SHOWERS OR STORMS.
ELEVATED CONVECTION THIS AFTN OVER NORTHERN IN WILL CONTINUE TO
TRACK ESE AND STAY SOUTH OF OUR AREA AS SUGGESTED BY CURRENT RGNL
RADAR TRENDS AND 850-300 MB THICKNESS MCS PROPAGATION/STEERING
TOOLS. THIS ACTIVITY DEVELOPED NORTH OF THE WEST TO EAST ORIENTED
QUASI STATIONARY FRONTAL BOUNDARY EXTENDING FROM CENTRAL IL TO
CENTRAL OH.
THE MCS OUTFLOW/COLD POOL WILL HELP TO CONTINUE TO PUSH THE BOUNDARY
FURTHER SOUTH LATE THIS AFTN/TONIGHT KEEPING ANY SHOWERS/STORMS
SOUTH OF OUR AREA TONIGHT. MILD CONDITIONS TO CONTINUE TONIGHT WITH
FAIRLY EXTENSIVE CLOUD COVER AND LOW TEMPS IN THE MID 60S TO LOWER
70S.
PREDOMINANTLY DRY CONDITIONS ARE ANTICIPATED THIS WEEKEND. FAVOR THE
00Z ECMWF WHICH INDICATES DRY CONDITIONS WILL CONTINUE AND EVEN THE
12Z GFS IS NOW TRENDING LOWER WITH POPS/QPF THIS WEEKEND. THE
FRONTAL BOUNDARY SHOULD BE FAR ENOUGH SOUTH SATURDAY TO KEEP THE
FOCUS OF MOST IF NOT ALL SHOWERS/STORMS OFF TO OUR SOUTH ACROSS
PORTIONS OF IL/IN/OH. MAX TEMPS SATURDAY WILL REACH THE UPPER 80S TO
LOWER 90S... COOLER RIGHT ALONG THE LAKE MI SHORELINE IN THE
WESTERLY FLOW.
MUCH OF THE SAME FOR SUNDAY WITH MAX TEMPS ONCE AGAIN AROUND THE 90
DEGREE MARK BUT SEVERAL DEGREES COOLER RIGHT ALONG THE LAKE MI
SHORELINE. ONCE AGAIN CANNOT COMPLETELY RULE OUT AN ISOLATED SHOWER
OR STORM MAINLY SOUTH OF I-96. HOWEVER A CONSENSUS OF 12Z SHORT
RANGE GUIDANCE/SREF POPS STILL SUGGESTS MOST IF NOT ALL STORMS WILL
STAY FURTHER SOUTH ACROSS PORTIONS OF IL/IN/OH.
.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 315 PM EDT FRI JUN 29 2012
THE MID RANGE MODELS CONTINUE TO SHOW SIMILAR SOLUTIONS OVERALL...
WITH HIGH PRESSURE ENTRENCHED ACROSS THE SOUTH OF THE NATION AND
RIDGING UP THE CENTER OF THE CONTINENT. DIFFERENCES ARISE WITH THE
SHORT WAVES OF LOW PRESSURE RIDING OVER THE RIDGE. HIGH CONFIDENCE
IN WARM AND MOSTLY DRY CONDITIONS THROUGH THE LONG TERM.
MOSTLY WEAK WAVES WILL MOVE OVER THE AREA ALONG THE EDGE OF THE HIGH
PRESSURE AND WILL HAVE LITTLE MOISTURE TO WORK WITH. THE BEST CHANCE
OF SHOWERS AND THUNDERSTORMS LOOKS TO BE TUESDAY NIGHT INTO
WEDNESDAY AS A STRONGER WAVE MOVES THROUGH CLOSE TO THE AREA.
TEMPERATURES ARE EXPECTED TO BE ABOVE NORMAL THROUGH THE LONG TERM.
THE ECMWF CONTINUES WARMER THAN THE GFS SOLUTION. NOT MUCH CHANGE
MADE. HIGHS ARE EXPECTED TO BE IN THE UPPER 80S TO AROUND 90 DEGREES
WITH LOWS IN THE MID 60S TO THE LOWER 70S. FIRE WEATHER CONCERNS
WILL BE HIGH HEADING INTO THE 4TH OF JULY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1147 PM EDT FRI JUN 29 2012
LATEST RADAR TRENDS SHOW THE THUNDERSTORMS ACROSS NORTHERN
ILLINOIS DIMINISHING AND IT APPEARS AZO TO JXN WILL NOT SEE MORE
THAN SOME THICK HIGHER CLOUDS OVERNIGHT. GENERALLY...VFR THROUGH
THE PERIOD WITH WEST WINDS AT OR BELOW 10 KNOTS.
&&
.MARINE...
ISSUED AT 315 PM EDT FRI JUN 29 2012
RATHER LIGHT WINDS WILL RESULT IN LOW WAVES TONIGHT THROUGH THE
WEEKEND.
&&
.HYDROLOGY...
ISSUED AT 315 PM EDT FRI JUN 29 2012
PREDOMINANTLY DRY WEATHER TO CONTINUE THROUGH THE WEEKEND AND FOR
MOST OF NEXT WEEK SO HYDRO CONCERNS ARE QUITE MINIMAL. AN ISOLATED
SHOWER OR STORM IS POSSIBLE THIS WEEKEND MAINLY SOUTH OF I-96 BUT
THE VAST MAJORITY OF THE AREA WILL NOT RECEIVE ANY MEASURABLE
RAINFALL THIS WEEKEND.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...93
SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...63
AVIATION...OSTUNO
HYDROLOGY...LAURENS
MARINE...LAURENS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
119 PM EDT THU JUN 28 2012
LATEST UPDATE...AVIATION...
.SYNOPSIS...
ISSUED AT 343 AM EDT THU JUN 28 2012
HOT CONDITIONS WILL PERSIST FOR THE REST OF THE WEEK AND EVEN INTO
EARLY NEXT WEEK. DAYTIME TEMPERATURES WILL BE WELL INTO THE 90S
TODAY...THEN REMAIN MAINLY IN THE UPPER 80S TO AROUND 90 FOR THE
WEEKEND AND EARLY NEXT WEEK.
THERE WILL BE A WEAK COLD FRONT THAT WILL CROSS THE AREA TODAY.
THIS MAY TRIGGER WIDELY SCATTERED STORMS THIS AFTERNOON INTO THIS
EVENING...HOWEVER MANY AREAS WILL REMAIN DRY. SOME OF THESE STORMS
COULD BE STRONG WITH HEAVY RAIN...GUSTY WINDS AND SMALL HAIL. THERE
WILL BE ANOTHER CHANCE OF STORMS ON SATURDAY AS ANOTHER WEAK COLD
FRONT COMES INTO THE REGION.
&&
.UPDATE...
ISSUED AT EDT THU JUN 28 2012
WILL BE EXPANDING THE HEAT ADVISORY TODAY TO INCLUDE THE ENTIRE
FORECAST AREA. WE ARE BASING THIS ON RECORD/NEAR RECORD EXPECTED
TEMPERATURES AND A LOT OF ONGOING OUTDOOR EVENTS. WILL TRY TO
HAVE THE NPW PRODUCT OUT BY 11 AM.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 343 AM EDT THU JUN 28 2012
WILL MAINTAIN THE CURRENT HEAT ADVISORY FOR THE I-94 CORRIDOR AWAY
FROM THE LAKE. HEAT INDEX READINGS SHOULD AT LEAST BRIEFLY FLIRT
WITH 100 BY EARLY TO MID AFTERNOON...PRIOR TO THE FRONT MOVING IN.
ELSEWHERE HEAT INDEX VALUES SHOULD REMAIN IN THE 90S. WITH THE
FRONT MOVING THROUGH THE AFTERNOON WE SHOULD SEE MAX TEMPS REACHED
EARLY TO MID AFTERNOON...THEN A BIT OF A COOLING WESTERLY WIND
WILL COME IN FROM THE LAKE...AND TEMPS AND HEAT INDEX READINGS
SHOULD BEGIN TO DROP.
STILL A LOT OF UNCERTAINTY WITH WHAT THE FRONT MAY PRODUCE IN THE
FORM OF CONVECTION. HRRR AND NSSL BOTH SUGGEST A FAIRLY DRY
FRONTAL PASSAGE AS WINDS BECOME WESTERLY WITH A STABILIZING EFFECT
FROM THE LAKE. HOWEVER WE SHOULD BE SITTING ON 2000-3000 J/KG OF
CAPE BY THE TIME THE FRONT ARRIVES. THERE IS A FAIR AMOUNT OF
CAPPING TO OVERCOME...BUT IF THIS WERE TO OCCUR...STORMS COULD
DEVELOP VERY QUICKLY...AND BECOME STRONG TO SEVERE. SHEAR VALUES
GRADUALLY INCREASE THROUGH THE DAY...FROM 25-30 KTS MID DAY TO
AROUND 40 KTS THROUGH THE AFTERNOON. THIS MAY ALSO HELP WITH MORE
ORGANIZED STORMS. HAVE BUMPED POPS UPWARD SLIGHTLY THIS AFTERNOON...
ALTHOUGH CONFIDENCE IN ANYTHING POPPING IS STILL UNCERTAIN.
THE REMNANTS OF THE FRONT STALLS OVER THE SOUTHERN CWA...SO WILL
CARRY 20 POPS THERE INTO FRIDAY. ELSEWHERE FRIDAY LOOKS DRY WITH
TEMPS AROUND 90 AGAIN.
A BETTER CHANCE OF STORMS INTO SATURDAY WITH ANOTHER COLD FRONT
COMING THROUGH. TIMING APPEARS TO COME THROUGH DURING THE HEAT OF
THE DAY AND MAX INSTABILITY. THEREFORE TWEAK POPS SLIGHTLY HIGHER.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 343 AM EDT THU JUN 28 2012
WARMER THAN NORMAL TEMPERATURES ARE LIKELY THROUGH MIDWEEK. THERE IS
A CHANCE OF THUNDERSTORMS EACH DAY BUT THE BEST CHANCE ARE SATURDAY
NIGHT INTO SUNDAY AND TUESDAY NIGHT INTO WEDNESDAY. HOWEVER
PRECIPITATION OF SIGNIFICANCE (GENERAL WETTING OVER A 1/2 INCH) IS
VERY UNLIKELY THROUGH WEDNESDAY AND WELL BEYOND THEN ACTUALLY.
THE LARGE SCALE MODELS LARGELY AGREE ON THE OVERALL PATTEN AND THIS
LEADS TO SOME GENERAL CONFIDENCE IN THE OVERALL FORECAST. MY PROBLEM
WITH THIS FORECAST THROUGH IS TIMING SHORTWAVES OVER THE CREST OF
THE UPPER RIDGE INTO SOUTHWEST MICHIGAN. SOUTHWEST MICHIGAN WILL
REMAIN ON THE EDGE OF THE POLAR JET (WHICH WILL LARGELY REMAIN JUST
NORTH AND EAST OF THIS AREA). BEING BETWEEN THE LARGE AND BUILDING
UPPER HIGH OVER THE CENTRAL AND WESTERN CONUS (LONG WAVE RIDGE AXIS
NEAR 100 W) AND THE EAST COAST TROUGH (LONG WAVE TROUGH NEAR 65 W)
BRINGS EVERY SHORTWAVE THAT TOPS THE UPPER RIDGE ACROSS SOUTHWEST
MICHIGAN. THAT WILL THEN RESULT IN POSSIBLE CONVECTION WITH EACH OF
THESE. SINCE THE POLAR JET IS FOR THE MOST PART NORTH AND EAST
OF HERE AND THERE IS NOT A LOT OF GULF INFLOW INTO ANY OF THESE
SHORTWAVES EVEN SO... I DO NOT SEE ANY OF THESE EVENTS AS BEGINNING
WET ENOUGH HELP OUR OVERALL DRY CONDITIONS OF LATE.
WHAT IS SEE HAPPENING AT UPPER LEVELS IS A LARGE STORM EAST OF THE
ALEUTIAN CHAIN THIS MORNING MOVING INTO THE LONG WAVE TROUGH JUST
OFF THE WEST COAST BY TUESDAY. THAT BUILDS AND RETROGRADES THE UPPER
HIGH OVER THE CENTRAL CONUS DURING THE NEXT 5 TO 6 DAYS. WHICH IS
WHY SOUTHWEST MICHIGAN END UP BEING ON THE EDGE OF THE POLAR JET BUT
NOT CLOSE ENOUGH TO BRING A GENERAL PRECIPITATION THREAT TO THE AREA
DURING THIS TIME PERIOD (UPPER LEVEL NORTHWEST FLOW IS NOT HOW
SOUTHWEST MICHIGAN GETS MOST OF OUR BIG PRECIPITATION EVENTS). MORE
THAN ANYTHING ELSE... THIS WILL DO TWO THINGS FOR SOUTHWEST
MICHIGAN.... KEEP THE REALLY COOL AIR NORTH AND EAST OF HERE AND THE
VERY HOT AIR SOUTH AND WEST OF HERE.
THE GENERIC FORECAST FOR THIS TIME PERIOD IS PARTLY CLOUDY WITH 20
PCT CHANCE OF THUNDERSTORMS. HIGHS 85 TO 90 AND LOWS 60 TO 70.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY MORNING)
ISSUED AT 119 PM EDT THU JUN 28 2012
VFR CONDITIONS SHOULD PREVAIL THROUGH 18Z FRIDAY. ISOLATED
THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON AND EVENING. THE RISK IS
LOW AND COVERAGE WOULD BE SMALL... SO LEFT VCTS AND CB WITH NO
PRECIPITATION. WINDS SHOULD REMAIN BELOW 15 KNOTS... EXCEPT NEAR ANY
STORMS WHERE GUSTS UP TO 50 KNOTS ARE POSSIBLE. HAIL IS ALSO
POSSIBLE WITH THE THUNDERSTORMS.
&&
.MARINE...
ISSUED AT 343 AM EDT THU JUN 28 2012
RATHER QUIET ON THE LAKE THROUGH THE SHORT TERM. WINDS SHOULD
LARGELY REMAIN 15 KTS OR LESS RESULTING IN LOW WAVE ACTION.
&&
.HYDROLOGY...
ISSUED AT 343 AM EDT THU JUN 28 2012
IF WE ARE ABLE TO GET ANY STORMS GOING TODAY THERE COULD BE
LOCALIZED HEAVY DOWNPOURS AS WE WILL BE SITTING ON NEARLY 2 INCHES
OF PRECIPITABLE WATER. HOWEVER THE STORMS WILL BE MOVING ALONG
QUICKLY WITH MID LEVEL WINDS AROUND 40 KTS. THE SAME WILL BE TRUE
OF THE PCPN CHANCES ON SATURDAY WITH LOCALIZED HEAVY RAIN POSSIBLE.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...HEAT ADVISORY UNTIL 9 PM EDT THIS EVENING FOR
MIZ037>040-043>046-
050>052-056>059-064>067-071>074.
LM...NONE.
&&
$$
UPDATE...TJT
SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...WDM
AVIATION...63
HYDROLOGY...JK
MARINE...JK
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
108 PM EDT THU JUN 28 2012
.SYNOPSIS...
ISSUED AT 343 AM EDT THU JUN 28 2012
HOT CONDITIONS WILL PERSIST FOR THE REST OF THE WEEK AND EVEN INTO
EARLY NEXT WEEK. DAYTIME TEMPERATURES WILL BE WELL INTO THE 90S
TODAY...THEN REMAIN MAINLY IN THE UPPER 80S TO AROUND 90 FOR THE
WEEKEND AND EARLY NEXT WEEK.
THERE WILL BE A WEAK COLD FRONT THAT WILL CROSS THE AREA TODAY.
THIS MAY TRIGGER WIDELY SCATTERED STORMS THIS AFTERNOON INTO THIS
EVENING...HOWEVER MANY AREAS WILL REMAIN DRY. SOME OF THESE STORMS
COULD BE STRONG WITH HEAVY RAIN...GUSTY WINDS AND SMALL HAIL. THERE
WILL BE ANOTHER CHANCE OF STORMS ON SATURDAY AS ANOTHER WEAK COLD
FRONT COMES INTO THE REGION.
&&
.UPDATE...
ISSUED AT 105 PM EDT THU JUN 28 2012
BUMPED HIGH TEMPERATURES UP BASED ON LATEST OBSERVATIONS. ALSO
KEPT A SLIGHT CHANCES OF THUNDERSTORMS AREAWIDE...WITH A SOMEWHAT
GREATER CHANCE NEAR THE I-94 CORRIDOR. THIS COMBINED WITH GREATER
THAN EXPECTED HUMIDITY WILL PRODUCE HEAT INDICES WELL INTO THE
UPPER 90S AND NEAR 100 IN SPOTS.
SURFACE DEWPOINTS HAVE MANAGED TO CLIMB TODAY INTO THE MID 60S F
WITH UPPER 60S UPSTREAM AROUND CHICAGO AND LOW 70S IN PARTS OF
WISCONSIN. HOWEVER...MDW ACARS SOUNDINGS AT 1530/1630Z SHOW A VERY
IMPRESSIVE CAP /30 DEGREES C AT 850 MB/ ALSO IS UPSTREAM. THIS
WILL BE VERY DIFFICULT TO OVERCOME...EVEN WITH SURFACE DEWPOINTS
IN THE MID/UPPER 60S. SYNOPTIC LIFT AHEAD OF UPPER POT VORT MAX
MOVING EAST INTO WI AT THIS TIME HAS RESULTED IN VERY MINOR
EROSION OF THE CAP BETWEEN 1530 AND 1630Z.
CURRENT THINKING IS THAT SURFACE BASED THUNDERSTORMS ARE UNLIKELY DUE
TO THIS CAP. HOWEVER...MID-LEVEL MOISTURE ORIGINATING FROM WEAK
CONVECTION OVER WI COULD INTRODUCE ISOLATED SHOWERS WITH AN
ATTENDANT THREAT FOR STRONG/SEVERE WINDS DUE TO VERY STEEP LAPSE
RATES.
UPDATE ISSUED AT EDT THU JUN 28 2012
WILL BE EXPANDING THE HEAT ADVISORY TODAY TO INCLUDE THE ENTIRE
FORECAST AREA. WE ARE BASING THIS ON RECORD/NEAR RECORD EXPECTED
TEMPERATURES AND A LOT OF ONGOING OUTDOOR EVENTS. WILL TRY TO
HAVE THE NPW PRODUCT OUT BY 11 AM.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 343 AM EDT THU JUN 28 2012
WILL MAINTAIN THE CURRENT HEAT ADVISORY FOR THE I-94 CORRIDOR AWAY
FROM THE LAKE. HEAT INDEX READINGS SHOULD AT LEAST BRIEFLY FLIRT
WITH 100 BY EARLY TO MID AFTERNOON...PRIOR TO THE FRONT MOVING IN.
ELSEWHERE HEAT INDEX VALUES SHOULD REMAIN IN THE 90S. WITH THE
FRONT MOVING THROUGH THE AFTERNOON WE SHOULD SEE MAX TEMPS REACHED
EARLY TO MID AFTERNOON...THEN A BIT OF A COOLING WESTERLY WIND
WILL COME IN FROM THE LAKE...AND TEMPS AND HEAT INDEX READINGS
SHOULD BEGIN TO DROP.
STILL A LOT OF UNCERTAINTY WITH WHAT THE FRONT MAY PRODUCE IN THE
FORM OF CONVECTION. HRRR AND NSSL BOTH SUGGEST A FAIRLY DRY
FRONTAL PASSAGE AS WINDS BECOME WESTERLY WITH A STABILIZING EFFECT
FROM THE LAKE. HOWEVER WE SHOULD BE SITTING ON 2000-3000 J/KG OF
CAPE BY THE TIME THE FRONT ARRIVES. THERE IS A FAIR AMOUNT OF
CAPPING TO OVERCOME...BUT IF THIS WERE TO OCCUR...STORMS COULD
DEVELOP VERY QUICKLY...AND BECOME STRONG TO SEVERE. SHEAR VALUES
GRADUALLY INCREASE THROUGH THE DAY...FROM 25-30 KTS MID DAY TO
AROUND 40 KTS THROUGH THE AFTERNOON. THIS MAY ALSO HELP WITH MORE
ORGANIZED STORMS. HAVE BUMPED POPS UPWARD SLIGHTLY THIS AFTERNOON...
ALTHOUGH CONFIDENCE IN ANYTHING POPPING IS STILL UNCERTAIN.
THE REMNANTS OF THE FRONT STALLS OVER THE SOUTHERN CWA...SO WILL
CARRY 20 POPS THERE INTO FRIDAY. ELSEWHERE FRIDAY LOOKS DRY WITH
TEMPS AROUND 90 AGAIN.
A BETTER CHANCE OF STORMS INTO SATURDAY WITH ANOTHER COLD FRONT
COMING THROUGH. TIMING APPEARS TO COME THROUGH DURING THE HEAT OF
THE DAY AND MAX INSTABILITY. THEREFORE TWEAK POPS SLIGHTLY HIGHER.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 343 AM EDT THU JUN 28 2012
WARMER THAN NORMAL TEMPERATURES ARE LIKELY THROUGH MIDWEEK. THERE IS
A CHANCE OF THUNDERSTORMS EACH DAY BUT THE BEST CHANCE ARE SATURDAY
NIGHT INTO SUNDAY AND TUESDAY NIGHT INTO WEDNESDAY. HOWEVER
PRECIPITATION OF SIGNIFICANCE (GENERAL WETTING OVER A 1/2 INCH) IS
VERY UNLIKELY THROUGH WEDNESDAY AND WELL BEYOND THEN ACTUALLY.
THE LARGE SCALE MODELS LARGELY AGREE ON THE OVERALL PATTEN AND THIS
LEADS TO SOME GENERAL CONFIDENCE IN THE OVERALL FORECAST. MY PROBLEM
WITH THIS FORECAST THROUGH IS TIMING SHORTWAVES OVER THE CREST OF
THE UPPER RIDGE INTO SOUTHWEST MICHIGAN. SOUTHWEST MICHIGAN WILL
REMAIN ON THE EDGE OF THE POLAR JET (WHICH WILL LARGELY REMAIN JUST
NORTH AND EAST OF THIS AREA). BEING BETWEEN THE LARGE AND BUILDING
UPPER HIGH OVER THE CENTRAL AND WESTERN CONUS (LONG WAVE RIDGE AXIS
NEAR 100 W) AND THE EAST COAST TROUGH (LONG WAVE TROUGH NEAR 65 W)
BRINGS EVERY SHORTWAVE THAT TOPS THE UPPER RIDGE ACROSS SOUTHWEST
MICHIGAN. THAT WILL THEN RESULT IN POSSIBLE CONVECTION WITH EACH OF
THESE. SINCE THE POLAR JET IS FOR THE MOST PART NORTH AND EAST
OF HERE AND THERE IS NOT A LOT OF GULF INFLOW INTO ANY OF THESE
SHORTWAVES EVEN SO... I DO NOT SEE ANY OF THESE EVENTS AS BEGINNING
WET ENOUGH HELP OUR OVERALL DRY CONDITIONS OF LATE.
WHAT IS SEE HAPPENING AT UPPER LEVELS IS A LARGE STORM EAST OF THE
ALEUTIAN CHAIN THIS MORNING MOVING INTO THE LONG WAVE TROUGH JUST
OFF THE WEST COAST BY TUESDAY. THAT BUILDS AND RETROGRADES THE UPPER
HIGH OVER THE CENTRAL CONUS DURING THE NEXT 5 TO 6 DAYS. WHICH IS
WHY SOUTHWEST MICHIGAN END UP BEING ON THE EDGE OF THE POLAR JET BUT
NOT CLOSE ENOUGH TO BRING A GENERAL PRECIPITATION THREAT TO THE AREA
DURING THIS TIME PERIOD (UPPER LEVEL NORTHWEST FLOW IS NOT HOW
SOUTHWEST MICHIGAN GETS MOST OF OUR BIG PRECIPITATION EVENTS). MORE
THAN ANYTHING ELSE... THIS WILL DO TWO THINGS FOR SOUTHWEST
MICHIGAN.... KEEP THE REALLY COOL AIR NORTH AND EAST OF HERE AND THE
VERY HOT AIR SOUTH AND WEST OF HERE.
THE GENERIC FORECAST FOR THIS TIME PERIOD IS PARTLY CLOUDY WITH 20
PCT CHANCE OF THUNDERSTORMS. HIGHS 85 TO 90 AND LOWS 60 TO 70.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 748 AM EDT THU JUN 28 2012
VFR CONDITIONS WILL PREVAIL THROUGH FRIDAY AFTERNOON. IT IS
POSSIBLE FROM LATE MORNING INTO EARLY THIS EVENING AN ISOLATED
THUNDERSTORMS COULD IMPACT SOME OF THE TAF SITES. HOWEVER THE RISK
IS RATHER LOW SO I PUT VCTS FOR NOW MOSTLY FROM 18Z TO 00Z FOR THE
WESTERN TAFS AND 21Z TO 03Z FOR THE EASTERN TAF SITES. WINDS COULD
BE GUSTY AND HAIL IS POSSIBLE WITH THE STRONGER THUNDERSTORMS.
&&
.MARINE...
ISSUED AT 343 AM EDT THU JUN 28 2012
RATHER QUIET ON THE LAKE THROUGH THE SHORT TERM. WINDS SHOULD
LARGELY REMAIN 15 KTS OR LESS RESULTING IN LOW WAVE ACTION.
&&
.HYDROLOGY...
ISSUED AT 343 AM EDT THU JUN 28 2012
IF WE ARE ABLE TO GET ANY STORMS GOING TODAY THERE COULD BE
LOCALIZED HEAVY DOWNPOURS AS WE WILL BE SITTING ON NEARLY 2 INCHES
OF PRECIPITABLE WATER. HOWEVER THE STORMS WILL BE MOVING ALONG
QUICKLY WITH MID LEVEL WINDS AROUND 40 KTS. THE SAME WILL BE TRUE
OF THE PCPN CHANCES ON SATURDAY WITH LOCALIZED HEAVY RAIN POSSIBLE.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...HEAT ADVISORY UNTIL 9 PM EDT THIS EVENING FOR MIZ037>040-043>046-
050>052-056>059-064>067-071>074.
LM...NONE.
&&
$$
UPDATE...TJT
SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...WDM
AVIATION...WDM
HYDROLOGY...JK
MARINE...JK
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1042 AM EDT THU JUN 28 2012
.SYNOPSIS...
ISSUED AT 343 AM EDT THU JUN 28 2012
HOT CONDITIONS WILL PERSIST FOR THE REST OF THE WEEK AND EVEN INTO
EARLY NEXT WEEK. DAYTIME TEMPERATURES WILL BE WELL INTO THE 90S
TODAY...THEN REMAIN MAINLY IN THE UPPER 80S TO AROUND 90 FOR THE
WEEKEND AND EARLY NEXT WEEK.
THERE WILL BE A WEAK COLD FRONT THAT WILL CROSS THE AREA TODAY.
THIS MAY TRIGGER WIDELY SCATTERED STORMS THIS AFTERNOON INTO THIS
EVENING...HOWEVER MANY AREAS WILL REMAIN DRY. SOME OF THESE STORMS
COULD BE STRONG WITH HEAVY RAIN...GUSTY WINDS AND SMALL HAIL. THERE
WILL BE ANOTHER CHANCE OF STORMS ON SATURDAY AS ANOTHER WEAK COLD
FRONT COMES INTO THE REGION.
&&
.UPDATE...
ISSUED AT EDT THU JUN 28 2012
WILL BE EXPANDING THE HEAT ADVISORY TODAY TO INCLUDE THE ENTIRE
FORECAST AREA. WE ARE BASING THIS ON RECORD/NEAR RECORD EXPECTED
TEMPERATURES AND A LOT OF ONGOING OUTDOOR EVENTS. WILL TRY TO
HAVE THE NPW PRODUCT OUT BY 11 AM.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 343 AM EDT THU JUN 28 2012
WILL MAINTAIN THE CURRENT HEAT ADVISORY FOR THE I-94 CORRIDOR AWAY
FROM THE LAKE. HEAT INDEX READINGS SHOULD AT LEAST BRIEFLY FLIRT
WITH 100 BY EARLY TO MID AFTERNOON...PRIOR TO THE FRONT MOVING IN.
ELSEWHERE HEAT INDEX VALUES SHOULD REMAIN IN THE 90S. WITH THE
FRONT MOVING THROUGH THE AFTERNOON WE SHOULD SEE MAX TEMPS REACHED
EARLY TO MID AFTERNOON...THEN A BIT OF A COOLING WESTERLY WIND
WILL COME IN FROM THE LAKE...AND TEMPS AND HEAT INDEX READINGS
SHOULD BEGIN TO DROP.
STILL A LOT OF UNCERTAINTY WITH WHAT THE FRONT MAY PRODUCE IN THE
FORM OF CONVECTION. HRRR AND NSSL BOTH SUGGEST A FAIRLY DRY
FRONTAL PASSAGE AS WINDS BECOME WESTERLY WITH A STABILIZING EFFECT
FROM THE LAKE. HOWEVER WE SHOULD BE SITTING ON 2000-3000 J/KG OF
CAPE BY THE TIME THE FRONT ARRIVES. THERE IS A FAIR AMOUNT OF
CAPPING TO OVERCOME...BUT IF THIS WERE TO OCCUR...STORMS COULD
DEVELOP VERY QUICKLY...AND BECOME STRONG TO SEVERE. SHEAR VALUES
GRADUALLY INCREASE THROUGH THE DAY...FROM 25-30 KTS MID DAY TO
AROUND 40 KTS THROUGH THE AFTERNOON. THIS MAY ALSO HELP WITH MORE
ORGANIZED STORMS. HAVE BUMPED POPS UPWARD SLIGHTLY THIS AFTERNOON...
ALTHOUGH CONFIDENCE IN ANYTHING POPPING IS STILL UNCERTAIN.
THE REMNANTS OF THE FRONT STALLS OVER THE SOUTHERN CWA...SO WILL
CARRY 20 POPS THERE INTO FRIDAY. ELSEWHERE FRIDAY LOOKS DRY WITH
TEMPS AROUND 90 AGAIN.
A BETTER CHANCE OF STORMS INTO SATURDAY WITH ANOTHER COLD FRONT
COMING THROUGH. TIMING APPEARS TO COME THROUGH DURING THE HEAT OF
THE DAY AND MAX INSTABILITY. THEREFORE TWEAK POPS SLIGHTLY HIGHER.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 343 AM EDT THU JUN 28 2012
WARMER THAN NORMAL TEMPERATURES ARE LIKELY THROUGH MIDWEEK. THERE IS
A CHANCE OF THUNDERSTORMS EACH DAY BUT THE BEST CHANCE ARE SATURDAY
NIGHT INTO SUNDAY AND TUESDAY NIGHT INTO WEDNESDAY. HOWEVER
PRECIPITATION OF SIGNIFICANCE (GENERAL WETTING OVER A 1/2 INCH) IS
VERY UNLIKELY THROUGH WEDNESDAY AND WELL BEYOND THEN ACTUALLY.
THE LARGE SCALE MODELS LARGELY AGREE ON THE OVERALL PATTEN AND THIS
LEADS TO SOME GENERAL CONFIDENCE IN THE OVERALL FORECAST. MY PROBLEM
WITH THIS FORECAST THROUGH IS TIMING SHORTWAVES OVER THE CREST OF
THE UPPER RIDGE INTO SOUTHWEST MICHIGAN. SOUTHWEST MICHIGAN WILL
REMAIN ON THE EDGE OF THE POLAR JET (WHICH WILL LARGELY REMAIN JUST
NORTH AND EAST OF THIS AREA). BEING BETWEEN THE LARGE AND BUILDING
UPPER HIGH OVER THE CENTRAL AND WESTERN CONUS (LONG WAVE RIDGE AXIS
NEAR 100 W) AND THE EAST COAST TROUGH (LONG WAVE TROUGH NEAR 65 W)
BRINGS EVERY SHORTWAVE THAT TOPS THE UPPER RIDGE ACROSS SOUTHWEST
MICHIGAN. THAT WILL THEN RESULT IN POSSIBLE CONVECTION WITH EACH OF
THESE. SINCE THE POLAR JET IS FOR THE MOST PART NORTH AND EAST
OF HERE AND THERE IS NOT A LOT OF GULF INFLOW INTO ANY OF THESE
SHORTWAVES EVEN SO... I DO NOT SEE ANY OF THESE EVENTS AS BEGINNING
WET ENOUGH HELP OUR OVERALL DRY CONDITIONS OF LATE.
WHAT IS SEE HAPPENING AT UPPER LEVELS IS A LARGE STORM EAST OF THE
ALEUTIAN CHAIN THIS MORNING MOVING INTO THE LONG WAVE TROUGH JUST
OFF THE WEST COAST BY TUESDAY. THAT BUILDS AND RETROGRADES THE UPPER
HIGH OVER THE CENTRAL CONUS DURING THE NEXT 5 TO 6 DAYS. WHICH IS
WHY SOUTHWEST MICHIGAN END UP BEING ON THE EDGE OF THE POLAR JET BUT
NOT CLOSE ENOUGH TO BRING A GENERAL PRECIPITATION THREAT TO THE AREA
DURING THIS TIME PERIOD (UPPER LEVEL NORTHWEST FLOW IS NOT HOW
SOUTHWEST MICHIGAN GETS MOST OF OUR BIG PRECIPITATION EVENTS). MORE
THAN ANYTHING ELSE... THIS WILL DO TWO THINGS FOR SOUTHWEST
MICHIGAN.... KEEP THE REALLY COOL AIR NORTH AND EAST OF HERE AND THE
VERY HOT AIR SOUTH AND WEST OF HERE.
THE GENERIC FORECAST FOR THIS TIME PERIOD IS PARTLY CLOUDY WITH 20
PCT CHANCE OF THUNDERSTORMS. HIGHS 85 TO 90 AND LOWS 60 TO 70.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 748 AM EDT THU JUN 28 2012
VFR CONDITIONS WILL PREVAIL THROUGH FRIDAY AFTERNOON. IT IS
POSSIBLE FROM LATE MORNING INTO EARLY THIS EVENING AN ISOLATED
THUNDERSTORMS COULD IMPACT SOME OF THE TAF SITES. HOWEVER THE RISK
IS RATHER LOW SO I PUT VCTS FOR NOW MOSTLY FROM 18Z TO 00Z FOR THE
WESTERN TAFS AND 21Z TO 03Z FOR THE EASTERN TAF SITES. WINDS COULD
BE GUSTY AND HAIL IS POSSIBLE WITH THE STRONGER THUNDERSTORMS.
&&
.MARINE...
ISSUED AT 343 AM EDT THU JUN 28 2012
RATHER QUIET ON THE LAKE THROUGH THE SHORT TERM. WINDS SHOULD
LARGELY REMAIN 15 KTS OR LESS RESULTING IN LOW WAVE ACTION.
&&
.HYDROLOGY...
ISSUED AT 343 AM EDT THU JUN 28 2012
IF WE ARE ABLE TO GET ANY STORMS GOING TODAY THERE COULD BE
LOCALIZED HEAVY DOWNPOURS AS WE WILL BE SITTING ON NEARLY 2 INCHES
OF PRECIPITABLE WATER. HOWEVER THE STORMS WILL BE MOVING ALONG
QUICKLY WITH MID LEVEL WINDS AROUND 40 KTS. THE SAME WILL BE TRUE
OF THE PCPN CHANCES ON SATURDAY WITH LOCALIZED HEAVY RAIN POSSIBLE.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...HEAT ADVISORY UNTIL 9 PM EDT THIS EVENING FOR MIZ037>040-043>046-
050>052-056>059-064>067-071>074.
LM...NONE.
&&
$$
UPDATE...TJT
SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...WDM
AVIATION...WDM
HYDROLOGY...JK
MARINE...JK
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
749 AM EDT THU JUN 28 2012
.SYNOPSIS...
ISSUED AT 343 AM EDT THU JUN 28 2012
HOT CONDITIONS WILL PERSIST FOR THE REST OF THE WEEK AND EVEN INTO
EARLY NEXT WEEK. DAYTIME TEMPERATURES WILL BE WELL INTO THE 90S
TODAY...THEN REMAIN MAINLY IN THE UPPER 80S TO AROUND 90 FOR THE
WEEKEND AND EARLY NEXT WEEK.
THERE WILL BE A WEAK COLD FRONT THAT WILL CROSS THE AREA TODAY.
THIS MAY TRIGGER WIDELY SCATTERED STORMS THIS AFTERNOON INTO THIS
EVENING...HOWEVER MANY AREAS WILL REMAIN DRY. SOME OF THESE STORMS
COULD BE STRONG WITH HEAVY RAIN...GUSTY WINDS AND SMALL HAIL. THERE
WILL BE ANOTHER CHANCE OF STORMS ON SATURDAY AS ANOTHER WEAK COLD
FRONT COMES INTO THE REGION.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 343 AM EDT THU JUN 28 2012
WILL MAINTAIN THE CURRENT HEAT ADVISORY FOR THE I-94 CORRIDOR AWAY
FROM THE LAKE. HEAT INDEX READINGS SHOULD AT LEAST BRIEFLY FLIRT
WITH 100 BY EARLY TO MID AFTERNOON...PRIOR TO THE FRONT MOVING IN.
ELSEWHERE HEAT INDEX VALUES SHOULD REMAIN IN THE 90S. WITH THE
FRONT MOVING THROUGH THE AFTERNOON WE SHOULD SEE MAX TEMPS REACHED
EARLY TO MID AFTERNOON...THEN A BIT OF A COOLING WESTERLY WIND
WILL COME IN FROM THE LAKE...AND TEMPS AND HEAT INDEX READINGS
SHOULD BEGIN TO DROP.
STILL A LOT OF UNCERTAINTY WITH WHAT THE FRONT MAY PRODUCE IN THE
FORM OF CONVECTION. HRRR AND NSSL BOTH SUGGEST A FAIRLY DRY
FRONTAL PASSAGE AS WINDS BECOME WESTERLY WITH A STABILIZING EFFECT
FROM THE LAKE. HOWEVER WE SHOULD BE SITTING ON 2000-3000 J/KG OF
CAPE BY THE TIME THE FRONT ARRIVES. THERE IS A FAIR AMOUNT OF
CAPPING TO OVERCOME...BUT IF THIS WERE TO OCCUR...STORMS COULD
DEVELOP VERY QUICKLY...AND BECOME STRONG TO SEVERE. SHEAR VALUES
GRADUALLY INCREASE THROUGH THE DAY...FROM 25-30 KTS MID DAY TO
AROUND 40 KTS THROUGH THE AFTERNOON. THIS MAY ALSO HELP WITH MORE
ORGANIZED STORMS. HAVE BUMPED POPS UPWARD SLIGHTLY THIS AFTERNOON...
ALTHOUGH CONFIDENCE IN ANYTHING POPPING IS STILL UNCERTAIN.
THE REMNANTS OF THE FRONT STALLS OVER THE SOUTHERN CWA...SO WILL
CARRY 20 POPS THERE INTO FRIDAY. ELSEWHERE FRIDAY LOOKS DRY WITH
TEMPS AROUND 90 AGAIN.
A BETTER CHANCE OF STORMS INTO SATURDAY WITH ANOTHER COLD FRONT
COMING THROUGH. TIMING APPEARS TO COME THROUGH DURING THE HEAT OF
THE DAY AND MAX INSTABILITY. THEREFORE TWEAK POPS SLIGHTLY HIGHER.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 343 AM EDT THU JUN 28 2012
WARMER THAN NORMAL TEMPERATURES ARE LIKELY THROUGH MIDWEEK. THERE IS
A CHANCE OF THUNDERSTORMS EACH DAY BUT THE BEST CHANCE ARE SATURDAY
NIGHT INTO SUNDAY AND TUESDAY NIGHT INTO WEDNESDAY. HOWEVER
PRECIPITATION OF SIGNIFICANCE (GENERAL WETTING OVER A 1/2 INCH) IS
VERY UNLIKELY THROUGH WEDNESDAY AND WELL BEYOND THEN ACTUALLY.
THE LARGE SCALE MODELS LARGELY AGREE ON THE OVERALL PATTEN AND THIS
LEADS TO SOME GENERAL CONFIDENCE IN THE OVERALL FORECAST. MY PROBLEM
WITH THIS FORECAST THROUGH IS TIMING SHORTWAVES OVER THE CREST OF
THE UPPER RIDGE INTO SOUTHWEST MICHIGAN. SOUTHWEST MICHIGAN WILL
REMAIN ON THE EDGE OF THE POLAR JET (WHICH WILL LARGELY REMAIN JUST
NORTH AND EAST OF THIS AREA). BEING BETWEEN THE LARGE AND BUILDING
UPPER HIGH OVER THE CENTRAL AND WESTERN CONUS (LONG WAVE RIDGE AXIS
NEAR 100 W) AND THE EAST COAST TROUGH (LONG WAVE TROUGH NEAR 65 W)
BRINGS EVERY SHORTWAVE THAT TOPS THE UPPER RIDGE ACROSS SOUTHWEST
MICHIGAN. THAT WILL THEN RESULT IN POSSIBLE CONVECTION WITH EACH OF
THESE. SINCE THE POLAR JET IS FOR THE MOST PART NORTH AND EAST
OF HERE AND THERE IS NOT A LOT OF GULF INFLOW INTO ANY OF THESE
SHORTWAVES EVEN SO... I DO NOT SEE ANY OF THESE EVENTS AS BEGINNING
WET ENOUGH HELP OUR OVERALL DRY CONDITIONS OF LATE.
WHAT IS SEE HAPPENING AT UPPER LEVELS IS A LARGE STORM EAST OF THE
ALEUTIAN CHAIN THIS MORNING MOVING INTO THE LONG WAVE TROUGH JUST
OFF THE WEST COAST BY TUESDAY. THAT BUILDS AND RETROGRADES THE UPPER
HIGH OVER THE CENTRAL CONUS DURING THE NEXT 5 TO 6 DAYS. WHICH IS
WHY SOUTHWEST MICHIGAN END UP BEING ON THE EDGE OF THE POLAR JET BUT
NOT CLOSE ENOUGH TO BRING A GENERAL PRECIPITATION THREAT TO THE AREA
DURING THIS TIME PERIOD (UPPER LEVEL NORTHWEST FLOW IS NOT HOW
SOUTHWEST MICHIGAN GETS MOST OF OUR BIG PRECIPITATION EVENTS). MORE
THAN ANYTHING ELSE... THIS WILL DO TWO THINGS FOR SOUTHWEST
MICHIGAN.... KEEP THE REALLY COOL AIR NORTH AND EAST OF HERE AND THE
VERY HOT AIR SOUTH AND WEST OF HERE.
THE GENERIC FORECAST FOR THIS TIME PERIOD IS PARTLY CLOUDY WITH 20
PCT CHANCE OF THUNDERSTORMS. HIGHS 85 TO 90 AND LOWS 60 TO 70.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 748 AM EDT THU JUN 28 2012
VFR CONDITIONS WILL PREVAIL THROUGH FRIDAY AFTERNOON. IT IS
POSSIBLE FROM LATE MORNING INTO EARLY THIS EVENING AN ISOLATED
THUNDERSTORMS COULD IMPACT SOME OF THE TAF SITES. HOWEVER THE RISK
IS RATHER LOW SO I PUT VCTS FOR NOW MOSTLY FROM 18Z TO 00Z FOR THE
WESTERN TAFS AND 21Z TO 03Z FOR THE EASTERN TAF SITES. WINDS COULD
BE GUSTY AND HAIL IS POSSIBLE WITH THE STRONGER THUNDERSTORMS.
&&
.MARINE...
ISSUED AT 343 AM EDT THU JUN 28 2012
RATHER QUIET ON THE LAKE THROUGH THE SHORT TERM. WINDS SHOULD
LARGELY REMAIN 15 KTS OR LESS RESULTING IN LOW WAVE ACTION.
&&
.HYDROLOGY...
ISSUED AT 343 AM EDT THU JUN 28 2012
IF WE ARE ABLE TO GET ANY STORMS GOING TODAY THERE COULD BE
LOCALIZED HEAVY DOWNPOURS AS WE WILL BE SITTING ON NEARLY 2 INCHES
OF PRECIPITABLE WATER. HOWEVER THE STORMS WILL BE MOVING ALONG
QUICKLY WITH MID LEVEL WINDS AROUND 40 KTS. THE SAME WILL BE TRUE
OF THE PCPN CHANCES ON SATURDAY WITH LOCALIZED HEAVY RAIN POSSIBLE.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...HEAT ADVISORY FROM NOON TODAY TO 9 PM EDT THIS EVENING FOR
MIZ072>074.
LM...NONE.
&&
$$
SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...WDM
AVIATION...WDM
HYDROLOGY...JK
MARINE...JK
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
343 AM EDT THU JUN 28 2012
.SYNOPSIS...
ISSUED AT 343 AM EDT THU JUN 28 2012
HOT CONDITIONS WILL PERSIST FOR THE REST OF THE WEEK AND EVEN INTO
EARLY NEXT WEEK. DAYTIME TEMPERATURES WILL BE WELL INTO THE 90S
TODAY...THEN REMAIN MAINLY IN THE UPPER 80S TO AROUND 90 FOR THE
WEEKEND AND EARLY NEXT WEEK.
THERE WILL BE A WEAK COLD FRONT THAT WILL CROSS THE AREA TODAY.
THIS MAY TRIGGER WIDELY SCATTERED STORMS THIS AFTERNOON INTO THIS
EVENING...HOWEVER MANY AREAS WILL REMAIN DRY. SOME OF THESE STORMS
COULD BE STRONG WITH HEAVY RAIN...GUSTY WINDS AND SMALL HAIL. THERE
WILL BE ANOTHER CHANCE OF STORMS ON SATURDAY AS ANOTHER WEAK COLD
FRONT COMES INTO THE REGION.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 343 AM EDT THU JUN 28 2012
WILL MAINTAIN THE CURRENT HEAT ADVISORY FOR THE I-94 CORRIDOR AWAY
FROM THE LAKE. HEAT INDEX READINGS SHOULD AT LEAST BRIEFLY FLIRT
WITH 100 BY EARLY TO MID AFTERNOON...PRIOR TO THE FRONT MOVING IN.
ELSEWHERE HEAT INDEX VALUES SHOULD REMAIN IN THE 90S. WITH THE
FRONT MOVING THROUGH THE AFTERNOON WE SHOULD SEE MAX TEMPS REACHED
EARLY TO MID AFTERNOON...THEN A BIT OF A COOLING WESTERLY WIND
WILL COME IN FROM THE LAKE...AND TEMPS AND HEAT INDEX READINGS
SHOULD BEGIN TO DROP.
STILL A LOT OF UNCERTAINTY WITH WHAT THE FRONT MAY PRODUCE IN THE
FORM OF CONVECTION. HRRR AND NSSL BOTH SUGGEST A FAIRLY DRY
FRONTAL PASSAGE AS WINDS BECOME WESTERLY WITH A STABILIZING EFFECT
FROM THE LAKE. HOWEVER WE SHOULD BE SITTING ON 2000-3000 J/KG OF
CAPE BY THE TIME THE FRONT ARRIVES. THERE IS A FAIR AMOUNT OF
CAPPING TO OVERCOME...BUT IF THIS WERE TO OCCUR...STORMS COULD
DEVELOP VERY QUICKLY...AND BECOME STRONG TO SEVERE. SHEAR VALUES
GRADUALLY INCREASE THROUGH THE DAY...FROM 25-30 KTS MID DAY TO
AROUND 40 KTS THROUGH THE AFTERNOON. THIS MAY ALSO HELP WITH MORE
ORGANIZED STORMS. HAVE BUMPED POPS UPWARD SLIGHTLY THIS AFTERNOON...
ALTHOUGH CONFIDENCE IN ANYTHING POPPING IS STILL UNCERTAIN.
THE REMNANTS OF THE FRONT STALLS OVER THE SOUTHERN CWA...SO WILL
CARRY 20 POPS THERE INTO FRIDAY. ELSEWHERE FRIDAY LOOKS DRY WITH
TEMPS AROUND 90 AGAIN.
A BETTER CHANCE OF STORMS INTO SATURDAY WITH ANOTHER COLD FRONT
COMING THROUGH. TIMING APPEARS TO COME THROUGH DURING THE HEAT OF
THE DAY AND MAX INSTABILITY. THEREFORE TWEAK POPS SLIGHTLY HIGHER.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 343 AM EDT THU JUN 28 2012
WARMER THAN NORMAL TEMPERATURES ARE LIKELY THROUGH MIDWEEK. THERE IS
A CHANCE OF THUNDERSTORMS EACH DAY BUT THE BEST CHANCE ARE SATURDAY
NIGHT INTO SUNDAY AND TUESDAY NIGHT INTO WEDNESDAY. HOWEVER
PRECIPITATION OF SIGNIFICANCE (GENERAL WETTING OVER A 1/2 INCH) IS
VERY UNLIKELY THROUGH WEDNESDAY AND WELL BEYOND THEN ACTUALLY.
THE LARGE SCALE MODELS LARGELY AGREE ON THE OVERALL PATTEN AND THIS
LEADS TO SOME GENERAL CONFIDENCE IN THE OVERALL FORECAST. MY PROBLEM
WITH THIS FORECAST THROUGH IS TIMING SHORTWAVES OVER THE CREST OF
THE UPPER RIDGE INTO SOUTHWEST MICHIGAN. SOUTHWEST MICHIGAN WILL
REMAIN ON THE EDGE OF THE POLAR JET (WHICH WILL LARGELY REMAIN JUST
NORTH AND EAST OF THIS AREA). BEING BETWEEN THE LARGE AND BUILDING
UPPER HIGH OVER THE CENTRAL AND WESTERN CONUS (LONG WAVE RIDGE AXIS
NEAR 100 W) AND THE EAST COAST TROUGH (LONG WAVE TROUGH NEAR 65 W)
BRINGS EVERY SHORTWAVE THAT TOPS THE UPPER RIDGE ACROSS SOUTHWEST
MICHIGAN. THAT WILL THEN RESULT IN POSSIBLE CONVECTION WITH EACH OF
THESE. SINCE THE POLAR JET IS FOR THE MOST PART NORTH AND EAST
OF HERE AND THERE IS NOT A LOT OF GULF INFLOW INTO ANY OF THESE
SHORTWAVES EVEN SO... I DO NOT SEE ANY OF THESE EVENTS AS BEGINNING
WET ENOUGH HELP OUR OVERALL DRY CONDITIONS OF LATE.
WHAT IS SEE HAPPENING AT UPPER LEVELS IS A LARGE STORM EAST OF THE
ALEUTIAN CHAIN THIS MORNING MOVING INTO THE LONG WAVE TROUGH JUST
OFF THE WEST COAST BY TUESDAY. THAT BUILDS AND RETROGRADES THE UPPER
HIGH OVER THE CENTRAL CONUS DURING THE NEXT 5 TO 6 DAYS. WHICH IS
WHY SOUTHWEST MICHIGAN END UP BEING ON THE EDGE OF THE POLAR JET BUT
NOT CLOSE ENOUGH TO BRING A GENERAL PRECIPITATION THREAT TO THE AREA
DURING THIS TIME PERIOD (UPPER LEVEL NORTHWEST FLOW IS NOT HOW
SOUTHWEST MICHIGAN GETS MOST OF OUR BIG PRECIPITATION EVENTS). MORE
THAN ANYTHING ELSE... THIS WILL DO TWO THINGS FOR SOUTHWEST
MICHIGAN.... KEEP THE REALLY COOL AIR NORTH AND EAST OF HERE AND THE
VERY HOT AIR SOUTH AND WEST OF HERE.
THE GENERIC FORECAST FOR THIS TIME PERIOD IS PARTLY CLOUDY WITH 20
PCT CHANCE OF THUNDERSTORMS. HIGHS 85 TO 90 AND LOWS 60 TO 70.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1159 PM EDT WED JUN 27 2012
VFR THROUGH THE EVENING...BUT SOME MVFR IS POSSIBLE BY 12Z THURSDAY
AS LOW LEVEL MOISTURE MOVES IN. SOME OF THE FORECAST GUIDANCE
SHOWS IFR NEAR MKG AS THE MOIST AIR MOVES OVER LAKE MICHIGAN AND
FORMS FOG AND LOW CLOUDS. DECIDED TO ADD THE IFR TO THE MKG
FORECAST ALTHOUGH THIS SHOULD BE IMPROVING TO MVFR AFTER SUNRISE
THURSDAY.
&&
.MARINE...
ISSUED AT 343 AM EDT THU JUN 28 2012
RATHER QUIET ON THE LAKE THROUGH THE SHORT TERM. WINDS SHOULD
LARGELY REMAIN 15 KTS OR LESS RESULTING IN LOW WAVE ACTION.
&&
.HYDROLOGY...
ISSUED AT 343 AM EDT THU JUN 28 2012
IF WE ARE ABLE TO GET ANY STORMS GOING TODAY THERE COULD BE
LOCALIZED HEAVY DOWNPOURS AS WE WILL BE SITTING ON NEARLY 2 INCHES
OF PRECIPITABLE WATER. HOWEVER THE STORMS WILL BE MOVING ALONG
QUICKLY WITH MID LEVEL WINDS AROUND 40 KTS. THE SAME WILL BE TRUE
OF THE PCPN CHANCES ON SATURDAY WITH LOCALIZED HEAVY RAIN POSSIBLE.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...HEAT ADVISORY FROM NOON TODAY TO 9 PM EDT THIS EVENING FOR
MIZ072>074.
LM...NONE.
&&
$$
SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...WDM
AVIATION...OSTUNO
HYDROLOGY...JK
MARINE...JK
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1106 PM CDT FRI JUN 29 2012
.UPDATE...
06Z AVIATION DISCUSSION ADDED BELOW.
&&
.DISCUSSION... /ISSUED 428 PM CDT FRI JUN 29 2012/
OVERVIEW...WELL ABOVE NORMAL TEMPERATURES ARE EXPECTED OVER THE
NEXT SEVERAL DAYS...WITH PLENTY OF 90S. A CHANCE FOR
THUNDERSTORMS IN THE COMING DAYS...THE FIRST WITH A SHORTWAVE
PASSING ACROSS NORTHERN CENTRAL MN TOMORROW AND THEN WITH A WARM
FRONT ON MONDAY.
SHORTWAVE RESPONSIBLE FOR TODAY`S CONVECTION TO THE WEST HAS
WEAKENED AS EVIDENT BY COOLING CLOUD TOPS AND LESS CLOUD TO GROUND
STRIKES. NONETHELESS...SHORTWAVE SHOULD DRIVE SHOWERS AND WEAK
THUNDERSTORMS TO THE SOUTHEAST AND AFFECT AT LEAST A SMALL POTION
OF THE SOUTHERN FORECAST AREA THIS EVENING. THE MAIN ACTIVITY
REMAINS ALONG THE SURFACE BOUNDARY TO OUR SOUTH STRETCHING TO THE
EAST ACROSS INTO THE OHIO VALLEY WHERE A DERECHO EVENT WITH 70-90
MPH WINDS IS CURRENTLY IN PROGRESS.
WEAK LEE SIDE TROUGHING TO THE WEST AND SURFACE HIGH PRESSURE TO
THE EAST WILL AID IN A LIGHT EAST SOUTHEASTERLY BOUNDARY LAYER
WIND BY LATE TOMORROW MORNING. LOOKING WEST IN WATER VAPOR
IMAGERY...THERE IS A SHORTWAVE NOTED OVER UTAH THIS AFTERNOON THAT
IS FORECAST TO REACH THE NORTHERN PLAINS BY SATURDAY MORNING. AN
UPPER JET STREAK APPEARS TO SET UP OVER THE REGION BY TOMORROW
MORNING SUCH THAT EASTERN SD IS UNDER THE LEFT EXIT REGION OF THE
JET STREAK BY TOMORROW MORNING. WEAK ACCAS TYPE SHOWERS OR
THUNDERSTORMS THAT MAY FORM FROM THE COMBINATION OF APPROACHING
SHORT-WAVE LIFT AND UPPER JET STREAK FORCING. SCATTERED
THUNDERSTORMS ARE POSSIBLE THROUGH THE EVENING AS UPPER LEVEL WAVE
PIVOTS THROUGH THE REGION.
THE FRONTAL BOUNDARY REMAINS IN PLACE TO OUR SOUTH THROUGH SUNDAY
WITH WEAK QUASI-NORTHWEST FLOW ON THE EAST SIDE OF ANTICYCLONIC
CURVATURE USHERING AT LEAST TWO MID LEVEL SHORTWAVE TROUGHS.
TIMING AND INTENSITIES OF THESE WAVES STILL A BIT UNCLEAR WITH
DIFFERING OPINIONS BETWEEN THE MODELS. BASED ON THIS SIGNAL...WENT
MORE WITH A MODEL CONSENSUS BLEND FOR SHOWER/THUNDERSTORM
PROBABILITIES WHICH YIELDS LOW-END CHANCES. FOR SUNDAY NIGHT
THROUGH MONDAY...LOOK FOR A WARM FRONT TO PUSH NORTHWARD INTO THE
AREA. MODELS SHOW LARGE/WEAK MOISTURE 850MB MOISTURE TRANSPORT
AHEAD OF THE FRONT WITH INCREASING ISENTROPIC LIFT. ON
MONDAY...THE VERY WARM NAM SHOWS MUCAPE CREEPING UP INTO THE
2500-5000J/KG RANGE WHILE THE GFS INDICATES 4500-6500J/KG AS PW/S
INCREASE INTO THE 1.5-2.0 INCH RANGE. AS SUCH...INCREASED
SHOWER/THUNDERSTORM CHANCES SLIGHTLY AND MAY HAVE TO GO HIGHER AT
SOME POINT. IN TERMS OF TEMPERATURES...THEY EXPECTED TO REMAIN
ABOVE NORMAL THROUGH MONDAY WITH HIGHS IN THE 80S TO LOWER 90S.
LOOK FOR HEAT INDICES TO INCREASE INTO THE UPPER 90S BY MONDAY
WITH INCREASING HUMIDITY LEVELS.
&&
.AVIATION.../06Z TAF ISSUANCE/
BIG QUESTION MARK FOR THIS TAF PERIOD IS WHAT DOES UPPER WAVE
CURRENTLY OVER NE MONTANA DO FOR THUNDER POTENTIAL AT TAF SITES.
00Z NAM INITIALIZING THIS WAVE BETTER THAN PREVIOUS RUNS...WITH
IT COMING INTO MN SEVERAL HOURS EARLIER THAN PREVIOUSLY EXPECTED.
WILL BE PLENTY OF INSTABILITY IN PLACE FOR IT TO WORK WITH...THE
ONLY PROBLEM...HIGH PRESSURE AT THE SFC AND WEAK H85 FLOW MAY END
UP LIMITING THUNDER POTENTIAL WITH THE WAVE. WITH THAT SAID...WOULD
NOT BE SURPRISED IF THIS WAVE KICKS OFF SOME CONVECTION ALONG THE
NRN EDGE OF THE INSTABILITY GRADIENT OVER THE ERN DAKOTAS LATE
MORNING/EARLY AFTERNOON AND SENDS IT EAST ACROSS THE MPX AREA
SATURDAY...THE ENDS OF THE LAST COUPLE OF HRRR RUNS WOULD GIVE
SOME MERITS TO THIS IDEA. AT THIS POINT CONFIDENCE NOT REAL HIGH
WITH CONVECTIVE POTENTIAL TOMORROW...BUT DID INCLUDE A VCTS AT AXN
AS THIS IS WHERE SREF PROBS FOR PRECIP IN THE AFTERNOON ARE
HIGHEST...THOUGH COULD SEE THE NEED FOR THUNDER SPREADING EAST
DEPENDING ON HOW THINGS EVOLVE TONIGHT. OTHER ISSUE WILL BE WIND
DIRECTIONS. HIGH PRESSURE WILL BE OVERHEAD DURING THIS
PERIOD...WITH A VERY BAGGY GRADIENT AND WINDS THAT LIKELY BE ALL
OVER THE PLACE...SO HAVE A LOT OF VRB WINDS MENTIONED.
KMSP...WILL HAVE TO WATCH WAVE OVER NE MT FOR CONVECTIVE POTENTIAL
AT THE FIELD. NAM SHOWS BRUNT OF WAVE GOING NORTH OF THE FIELD
DURING THE AFTERNOON...BUT WITH INSTABILITY GRADIENT
NEARBY...COULD SEE THUNDER IN THE AFTERNOON. AT THIS POINT
CONFIDENCE IS REALLY LOW ON ANY CONVECTIVE PLACEMENT...SO LEFT IT
OUT. WINDS WILL BE VERY LIGHT...BUT TREND OUT OF THE EAST TO SOUTH
ON SATURDAY.
/OUTLOOK/
.SUNDAY...VFR. SMALL CHANCE OF TSRA.
.MONDAY...VFR. CHANCE FOR TSRA OVERNIGHT.
.TUESDAY...VFR. SMALL CHANCE OF TSRA.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
CLF/MPG
AREA FORECAST DISCUSSION
NWS HASTINGS NE
108 AM CDT THU JUN 28 2012
.UPDATE...KUEX INDICATES ISOLATED CONVECTIVE ACTIVITY DEVELOPING OVER
PORTIONS OF NORTH CENTRAL KANSAS AND SOUTH CENTRAL
NEBRASKA...PRIMARILY ALONG AND SOUTHEAST OF LINE FROM KK82 TO
KHJH. RAP ANALYSIS INDICATES A 40-50KT 850MB JET STREAK EXISTS
OVER THIS AREA WITH ISENTROPIC UPGLIDE PRESENT AROUND THE 310K
SURFACE. RAP ANALYSIS PROXIMITY SOUNDINGS FROM OUR SOUTHEASTERN CWA
SUGGEST A STRONG THERMAL INVERSION THROUGH ABOUT 800MB SHOULD KEEP
CONVECTION ON THE WEAK SIDE. WENT AHEAD AND INTRODUCED SLIGHT
CHANCE POPS TO OUR SOUTHEAST TO ACCOUNT FOR THIS ACTIVITY.
&&
.PREV DISCUSSION... /ISSUED 1201 AM CDT THU JUN 28 2012/
AVIATION...06Z KGRI TAF. VFR CONDITIONS TO CONTINUE THROUGH THE
NEXT 24 HOURS. DECAYING THUNDERSTORM ACTIVITY HAS PROMOTED AN AREA
OF LOW LEVEL OUTFLOW WHICH IS APPROACHING KGRI FROM THE WEST. KUEX
INDICATES THE LEADING EDGE OF THIS OUTFLOW WILL LIKELY INFILTRATE
KGRI BETWEEN 05Z AND 06Z. THIS WILL PRESENT WEST/NORTHWESTERLY
SURFACE WINDS 06-09Z...AT WHICH TIME SURFACE WINDS SHOULD BECOME
MORE ESTABLISHED FROM THE NORTHEAST. HIGH LEVEL CLOUDS NEAR
20000FT AGL WILL BE POSSIBLE THROUGH MUCH OF THE TAF PERIOD.
VISIBILITY RESTRICTIONS ARE NOT EXPECTED THROUGH THE NEXT 24
HOURS.
PREV DISCUSSION... /ISSUED 1041 PM CDT WED JUN 27 2012/
UPDATE...UPDATED THE FORECAST TONIGHT TO CLEAN UP FIRE
WEATHER/HEAT PRODUCTS AND TO INCLUDE A SLIGHT CHANCE OF SHOWERS
AND THUNDERSTORMS IN THE NORTHWESTERN THIRD OF THE CWA TONIGHT
ALONG AN NEAR AND NORTH OF AN ELEVATED FRONT AS A RIPPLE OF ENERGY
MOVES BY. WE ARE SO CAPPED THAT ANY CONVECTION WILL STRUGGLE TO
STAY TOGETHER.
PREV DISCUSSION... /ISSUED 411 PM CDT WED JUN 27 2012/
SHORT TERM...TONIGHT THROUGH THURSDAY. AFTER STARTING OFF THE DAY
RATHER WARM WITH READINGS WELL IN THE 70S THIS MORNING...TEMPERATURES
HAVE SKY ROCKETED WELL INTO THE 90S...ALTHOUGH READINGS OVER 100F
HAVE BEEN MORE OF THE NORM THIS AFTERNOON. KGRI HAS ALREADY
REACHED A NEW RECORD HIGH OF 107 DEGREES...WITH THE PREVIOUS
RECORD 105 DEGREES SET BACK IN 1936. THE ALL TIME JUNE RECORD HIGH
FOR GRAND ISLAND IS 108 SET IN 1946 AND 1933...AND WE ARE EDGING
CLOSER TO THAT...IT WILL BE CLOSE. THE DRY...HOT CONDITIONS HAVE
ALSO BEEN CONDUCIVE FOR HAZARDOUS FIRE WEATHER
CONDITIONS...ESPECIALLY IN OUR SOUTH AND EAST WHERE WINDS HAVE
BEEN GUSTING BETWEEN 30 AND 40 MPH...AND A RED FLAG WARNING
REMAINS IN EFFECT UNTIL 9 PM. A FIRE/SMOKE PLUME WHICH ORIGINATED
IN PHILLIPS COUNTY KANSAS WAS EVIDENT ON KUEX RADAR EARLY THIS
AFTN.
PATTERN ALOFT REFLECTED AN UPPER LEVEL RIDGE OF HIGH PRESSURE
ENTRENCHED ACROSS THE INTERIOR CONUS...WHILE A LOW PRESSURE SYSTEM
TRACKED ACROSS SASKATCHEWAN. AT THE SURFACE...SUBTLE COOL FRONTAL
BOUNDARY HAD EDGED FARTHER SOUTH INTO NEBRASKA AND EXTENDED FROM
KMCK TO KBBW TO KONL. FRONTAL BOUNDARY WILL CONTINUE TO SAG SOUTH
THIS EVENING AND TONIGHT AND STALL NEAR THE NEB/KS STATE LINE INTO
NW KANSAS. STRONG CAP IS IN PLACE WITH MID LEVEL TEMPS AROUND
18C...WHICH ONLY COOL A COUPLE OF DEGREES IN OUR NORTH TONIGHT.
SOME CONCERN THAT CONVECTION WHICH DEVELOPS ALONG THE FRONT
RANGE/HIGH PLAINS MAY WORK TOWARDS OUR WESTERN CWA LATE
TONIGHT...BUT CONFIDENCE IS RATHER LOW WITH STRONG CAP AND WILL KEEP
THINGS DRY...OR JUST SILENT POPS. NOSE OF LLVL JET FOCUSES TOWARDS
THE MISSOURI RIVER TONIGHT AND COULD SEE CONVECTION ATTEMPT TO
DEVELOP TOWARD DAYBREAK AROUND OUR NORTHEAST ZONES BUT AGAIN
CONFIDENCE IS NOT HIGH AND WILL LEAVE FCST DRY ATTM.
HEAT IS ANOTHER BIG CONCERN FOR SEVERAL UPCOMING DAYS. KANSAS
ZONES ARE FORECAST AOA THE CENTURY MARK THROUGH THE REMAINDER OF THE
WEEK AND WILL CONVERT THE CURRENT HEAT ADVISORY TO AN EXCESSIVE HEAT
WARNING THROUGH 02Z SATURDAY. THIS AREA HAS SEEN SEVERAL DAYS WITH
HEAT ADVISORY CONDITIONS WITH LITTLE REPRIEVE EXPECTED. INTO SOUTH
CENTRAL NEBRASKA...HEAT ADVISORY CONDITIONS ARE A LITTLE MORE
MARGINAL FOR THURSDAY AND WILL BE DEPENDENT UPON FRONTAL BOUNDARY
WHICH THE NAM STALLS AND THE GFS WASHES OUT. ATTM...WILL BUFFER THE
NC KS EXCESSIVE HEAT WARNING WITH A HEAT ADVISORY EDGING NORTH TO
HIGHWAY IN PORTIONS OF SOUTH CENTRAL NEBRASKA. THE HEADLINE CHANGES
SHOULD BE A GOOD STARTING PLACE FOR WHAT STILL LOOKS LIKE A
PROLONGED HEAT EVENT FOR THE CENTRAL PLAINS BASED ON EXTENDED
FORECAST MODELS.
FRONTAL BOUNDARY MEANDERING OR WASHING OUT THURSDAY WILL RESULT IN
LESS WIND FOR OUR REGION AND WIND SPEEDS WILL BE BELOW CRITERIA FOR
A FIRE WEATHER HEADLINE.
LONG TERM...THURSDAY EVENING THROUGH NEXT WEDNESDAY. AS WAS THE
CASE YESTERDAY...OVERALL FEW NOTABLE CHANGES WERE MADE TO THE
FORECAST FOR THE DAYS 3-7 PERIOD. THIS MEANS THAT HIGHLY
QUESTIONABLE BUT NONETHELESS POSSIBLE THUNDERSTORM CHANCES
CONTINUE MAINLY IN THE THURS NIGHT THROUGH SAT NIGHT TIME
FRAME...ALONG WITH WELL-ABOVE NORMAL TEMPERATURES. FOR A BIT MORE
INSIGHT TO THE POTENTIAL HISTORICAL SIGNIFICANCE OF THIS EARLY
SUMMER HEAT...PLEASE SEE THE SEPARATE CLIMATE SECTION BELOW...AND
FOR MORE INSIGHT ON THE HEAT HEADLINES ONGOING THROUGH THURSDAY OR
FRIDAY...PLEASE SEE THE SHORT TERM SECTION ABOVE.
STARTING WITH THURSDAY EVENING/NIGHT...CONTINUED TO BLANKET THE
CWA WITH 20-30 PERCENT STORM CHANCES...ALTHOUGH CONFIDENCE IN
MOST AREAS SEEING ANYTHING IS QUITE LOW GIVEN CONSIDERABLE CAPPING
EVIDENCED BY 700MB TEMPS IN THE +13-15C RANGE. THAT BEING
SAID...BOTH THE 18Z NAM/12Z GFS ADVERTISE THE DEVELOPMENT OF
STORMS ACROSS PARTS OF THE CWA...MAINLY NORTH OF THE EAST-WEST
SURFACE FRONT DRAPED NEAR THE STATE LINE...AND WITHIN A MODEST BUT
EVIDENT EXIT REGION OF THE LOW LEVEL JET. IF STORMS DO MANAGE TO
AFFECT SOME AREAS...IT COULD BE A COMBINATION OF ACTIVITY
DEVELOPING OVERHEAD...AND STORMS POSSIBLY ROLLING EAST OFF THE
HIGH PLAINS. ALTHOUGH ANY STORMS SHOULD REMAIN ELEVATED DUE TO
CONSIDERABLE LOW LEVEL CAPPING...A STRONG TO SEVERE STORM IS NOT
COMPLETELY OUT OF THE QUESTION IF PARCELS CAN TAKE ADVANTAGE OF A
FEW THOUSAND J/KG OF ELEVATED CAPE IN THE PRESENCE OF POSSIBLY
25-30KT OF DEEP LAYER SHEAR. THIS THINKING IS CONSISTENT WITH THE
TOKEN 5 PERCENT SEVERE PROBABILITIES ON THE LATEST SPC DAY 2
OUTLOOK.
FOR THE FRIDAY THROUGH SUNDAY TIME FRAME...BOTH THE 12Z ECMWF/GFS
ARE IN DECENT AGREEMENT ON THE LARGER SCALE PICTURE...WITH THE CWA
REMAINING ALONG THE NORTHERN PERIPHERY OF THE DOMINANT SOUTHERN
CONUS RIDGE. ALTHOUGH PERIODIC...MAINLY WEAK SHORTWAVES WILL
RIPPLE THROUGH THE QUASI-ZONAL MID LEVEL FLOW...CAPPING TO SURFACE
OR NEAR SURFACE BASED PARCELS WILL REMAIN QUITE STRONG WITH 700MB
LEVEL TEMPS CONTINUING TO AVERAGE IN THE +13-15 TERRITORY.
ALTHOUGH THE DEVELOPMENT OF STORMS IN ANY GIVEN PERIOD IS STILL
HIGHLY QUESTIONABLE...WE HAVE BEEN CARRYING TOKEN SLIGHT STORM
CHANCES OVER THE WEEKEND FOR AT LEAST A FEW DAYS NOW...AND JUST
DON/T HAVE THE CONFIDENCE OR HEART TO PULL THEM OUT OF ANY GIVEN
PERIOD YET. TEMP WISE...MADE SLIGHT UPWARD ADJUSTMENTS TO HIGHS
FRIDAY-SUNDAY...WITH MID-UPPER 90S PREVALENT IN NEB ZONES...AND
100-110 IN KS.
FOR SUNDAY NIGHT THROUGH WEDNESDAY...THERE IS NO RAIN MENTION IN
THE FORECAST AT THIS TIME...AS THE GFS AND ESPECIALLY THE ECMWF
ADVERTISE THE NORTHWARD EXPANSION OF THE SOUTHERN CONUS
RIDGE...WITH THE CENTER OF THE MID LEVEL CLOCKWISE CIRCULATION
RIGHT BACK OVER/VERY NEAR THE CENTRAL PLAINS BY MID WEEK. THIS
SHOULD RESULT IN A SIMILAR SETUP TO THE PAST FEW DAYS...WITH
PLENTY OF LOW LEVEL CAPPING TO CONVECTIVE CHANCES...AND VERY WARM
TEMPERATURES. FOR NOW...HAVE STUCK WITH THE ALLBLEND MODEL
CONSENSUS WITH HIGH TEMPS MONDAY-WEDNESDAY MAINLY UPPER 90S IN NEB
ZONES AND 100-105 IN KANSAS...BUT COULD EASILY FORESEE THESE
VALUES BEING 5+ DEGREES HIGHER THAN CURRENTLY ADVERTISED ON SOME
DAYS IF THE RIDGE BECOMES AS DOMINANT AS CURRENTLY PROGGED.
FIRE WEATHER...BESIDES THE ONGOING RED FLAG WARNING FOR THE
SOUTHERN 1/2 OF THE CWA IN EFFECT THROUGH THIS EVENING...THE NEXT
BEST CANDIDATE FOR POSSIBLY REACHING RED FLAG WARNING CRITERIA OF
RH LESS THAN 20 PERCENT AND WINDS OF 20 MPH IS FRIDAY
AFTERNOON/EARLY EVENING...MAINLY IN KS COUNTIES. THIS IS DUE TO
INCREASING SOUTHERLY WINDS AS THE SURFACE FRONT LIFTS BACK NORTH.
WITH THIS STILL BEING TWO DAYS AWAY...AND THE DETAILS STILL A BIT
UNCLEAR MAINLY REGARDING WIND SPEEDS...WILL HOLD OFF FOR NOW ON
ANY FIRE WEATHER WATCH HEADLINES BUT THIS WILL BE SOMETHING TO
KEEP AN EYE ON.
CLIMATE...ALTHOUGH IT WILL BE SEVERAL DAYS BEFORE THE HISTORICAL
SIGNIFICANCE OF THIS EARLY SUMMER HEAT IS FULLY KNOWN...THIS IS
UNDOUBTEDLY ONE OF THE HOTTEST STRETCHES OF LATE JUNE-EARLY JULY
WEATHER EXPERIENCED IN SEVERAL YEARS. FOCUSING SPECIFICALLY ON
GRAND ISLAND FOR THE 10-DAY PERIOD JUNE 26-JULY 5...FORECAST HIGHS
FOR THE NEXT SEVERAL DAYS WOULD RESULT IN A DAILY AVERAGE
TEMPERATURE DURING THIS STRETCH AROUND 98 DEGREES. THE LAST TIME
THE PERIOD JUNE 26-JULY 5 YIELDED AN AVERAGE DAILY HIGH NEAR 98
DEGREES WAS IN 1991. THE LAST TIME A 10 DAY STRETCH AT ANY POINT
IN THE SUMMER YIELDED AN AVERAGE HIGH OF 98 DEGREES WAS BETWEEN
JULY 7-16, 1995. FOR LOCATIONS FARTHER SOUTH INTO NORTH CENTRAL
KANSAS THAT ARE MORE ACCUSTOMED TO TOPPING 100 DEGREES...THIS
APPEARS TO BE THE HOTTEST 10-DAY STRETCH SINCE AT LEAST AUGUST
2000. AGAIN THOUGH...THESE COMPARISONS ARE ALL DEPENDENT ON HOW
WELL THE CURRENT FORECAST VERIFIES OVER THE NEXT WEEK OR SO. NO
MATTER WHAT...PARTS OF THE CWA COULD POTENTIALLY BE IN A CATEGORY
D3 SEVERE DROUGHT DESIGNATION FROM THE U.S. DROUGHT MONITOR WITHIN
THE NEXT 1-2 WEEKS IF THIS WEATHER PATTERN PERSISTS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...HEAT ADVISORY UNTIL 9 PM CDT THIS EVENING FOR NEZ074>077-082>087.
KS...EXCESSIVE HEAT WARNING UNTIL 9 PM CDT FRIDAY FOR KSZ005>007-
017>019.
&&
$$
110 AM UPDATE/AVIATION...BRYANT
1041 PM UPDATE...HEINLEIN
SHORT TERM...FAY
LONG TERM/FIRE WEATHER/CLIMATE...PFANNKUCH
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
129 AM EDT THU JUN 28 2012
.SYNOPSIS...
AS SURFACE HIGH PRESSURE TAKES HOLD AND A STRONG UPPER RIDGE BUILDS
OVER THE SOUTHEAST...A WARMING TREND WILL OCCUR BRINGING POSSIBLE
RECORD HEAT AND HUMIDITY TO THE CAROLINAS BY THIS WEEKEND INTO EARLY
NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 130 AM THURSDAY...TWEAKED OVERNIGHT TEMPERATURES DOWN SLIGHTLY
ESPECIALLY NEAR THE COAST WHERE OFFSHORE WINDS AT THE BEACHES
(LANDBREEZE) WILL NEGATE ANY MARINE INFLUENCE. NORTH MYRTLE BEACH
AND GEORGETOWN MAY GET AS COLD AS ANY OF OUR INTERIOR LOCATIONS
TONIGHT. OTHERWISE NO SIGNIFICANT CHANGES. PREVIOUS DISCUSSION FROM
1000 PM FOLLOWS...
EXCELLENT RADIATIONAL COOLING CONDITIONS OVERNIGHT. WINDS HAVING
DIMINISHED TO NEARLY CALM INLAND...EXCEPT REMAINING 2 TO 4 MPH ALONG
THE IMMEDIATE BEACHES. A LAND BREEZE LIKELY WILL OCCUR ALONG THE
IMMEDIATE COAST BY THU DAYBREAK WITH SSTS IN THE MID TO UPPER 70S
AND LOWS AWAY FROM THE BEACHES IN THE UPPER 50S TO LOWER 60S...WITH
DEWPOINTS MIMICKING TEMPS ESPECIALLY SEVERAL HRS LEADING TO SUNRISE.
CURRENT MIN FORECAST IN LINE WITH ONLY TWEAKS UPWARD BY A DEGREE OR
2 NEEDED FOR THE BEACHES. SFC HIGH PRESSURE TO RIDGE ACROSS THE
EASTERN CAROLINAS FROM ITS CENTER LOCATED OVER CENTRAL GEORGIA. NO
POPS WITH A CLOUDLESS SKY ON TAP FOR THE ILM CWA TONIGHT. LITTLE
MOISTURE IN THE ATM COLUMN VIA NEARBY 00Z RAOBS...WITH PWS LESS THAN
3/4 OF AN INCH. SUBSIDENCE ALOFT AND SOME SERIOUS CAPPING FROM 850MB
AND UPWARDS...WITH INSTABILITY LACKING.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...HIGH PRESSURE ALOFT WILL BUILD IN THROUGH
THE PERIOD...BRINGING WITH IT INCREASING HEAT AND HUMIDITY. UNDER
MAINLY CLEAR SKIES...MAX TEMPERATURES ARE EXPECTED TO REACH THE
UPPER 80S TO LOWER 90S...PERHAPS MID 90S WELL INLAND ON THURSDAY.
FRIDAY WILL SEE TEMPERATURES RANGE FROM THE MID 90S TO AROUND 100
DEGREES. ON THURSDAY...MOISTURE WILL BE LACKING SUCH THAT APPARENT
TEMPERATURES MAY ACTUALLY BE LOWER THAN THE ACTUAL TEMPERATURES.
FRIDAY WILL BE A DIFFERENT STORY THOUGH AS DEWPOINTS RECOVER INTO
THE 70 TO 75 DEGREE RANGE. WHILE DEWPOINT TEMPERATURES COULD FALL
DUE TO MIXING DURING THE AFTERNOON...THERE COULD BE A PERIOD OF 2 OR
THREE HOURS WHERE TEMPERATURES AND DEWPOINTS COMBINE TO YIELD
APPARENT TEMPERATURES AROUND 105 DEGREES. MINS THURSDAY NIGHT WILL
BE WITHIN A COUPLE DEGREES OF 70 WHILE MINS FRIDAY NIGHT SHOULD BE
IN THE MID TO UPPER 70S.
IT SHOULD BE NOTED THAT THERE WILL BE A PIEDMONT TROUGH AND SEA
BREEZE FRONT PRESENT BOTH DAYS. THERE COULD BE ENOUGH LIFT
ASSOCIATED WITH THESE FEATURES TO PRODUCE A FEW CLOUDS DESPITE
STRONG RIDGING ALOFT...ESPECIALLY FRIDAY WHERE LOW LEVEL MOISTURE
WILL BE THE GREATEST. ON FRIDAY...IT IS POSSIBLE THAT A
STRAY THUNDERSTORM COULD FORM ALONG THESE FEATURES...ESPECIALLY THE
SEA BREEZE WHERE LOW LEVEL MOISTURE WOULD BE MOST ABUNDANT. POPS
ARE BASICALLY 0 THURSDAY AND 10 PERCENT OR LESS FRIDAY.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 3 PM WEDNESDAY...SIZZLING DAYTIME TEMPERATURES AND ASPHALT
MIRAGES WILL BE OBSERVED THIS WEEKEND AS INTENSE HEAT TAKES HOLD OF
THE AREA...AS A MAMMOTH RIDGE ALOFT BARRELS SLOWLY EAST INTO THE
CAROLINAS. AN EXCESSIVE HEAT WATCH WAS ISSUED TO ADDRESS THE HEAT
INDEX VALUES BETWEEN 102-112 FRI AND SAT. AT A MINIMUM OVER THE
WEEKEND HEAT ADVISORIES WILL BE NEEDED FOR H.I. VALUES OVER 105
DEGREES...AND POSSIBLY A WARNING IN SOME LOCATIONS SATURDAY AS INDEX
VALUES NEAR OR EXCEED 110 DEGREES. HEAT ADVISORIES OR WARNINGS MAY
BE NEEDED BEYOND SATURDAY...BUT THE WATCH TIME FOR NOW IS VALID
THROUGH SATURDAY AFTERNOON MAINLY DUE TO THE NATURAL INCREASE IN
UNCERTAINTY IN THE EXTENDED. IF YOU BELIEVE IN THE ECMWF...WE COULD
HAVE AN EXTENDED HEAT WAVE WELL INTO NEXT WEEK.
RECORD HIGHS AT ILM...FRIDAY 101 (1959) SATURDAY 100 (1959)
SUNDAY 98 (1990) MONDAY 97 (1980).
RECORD HIGHS AT FLO...FRIDAY 101 (1998) SATURDAY 103 (1990)
SUNDAY 101 (1990) MONDAY 102 (1954).
AT THE SURFACE AN AMPLIFIED THERMAL-TROUGH AXIS WILL RESIDE OVER
THE FAR INTERIOR AND SANDHILLS. THIS SHOULD SUSTAIN SW WIND FLOW
OVER THE AREA THROUGH THE EXTENDED PERIOD. LARGE LAND VS SEA TEMP
DIFFERENTIAL SHOULD DRIVE A ROBUST SEA BREEZE CIRCULATION...AND
AFTERNOON GUSTS TO 20 KT ALONG THE COAST CAN BE EXPECTED EACH
AFTERNOON TO EARLY EVENING.
THE REMNANTS OF DEBBY WILL PASS WELL E AND NE OF THE COAST OVER
THE WEEKEND AND INTO THE CANADIAN MARITIME BY DAYBREAK WEDNESDAY
WITH LITTLE TO NO IMPACT HERE...EXPECT POTENTIALLY INCREASING THE
RIP THREAT...BUT EVEN THIS WILL REMAIN LIMITED IN LOCAL IMPACT.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 06Z...VFR CONDITIONS EXPECTED THROUGH THE END OF THE FORECAST
PERIOD. A BROAD UPPER RIDGE WITH VERY DRY AIR ALOFT WILL MOVE INTO
THE REGION OVER THE NEXT 24 HOURS. CALM WINDS THIS MORNING WILL GIVE
WAY TO A SOUTHWESTERLY WIND AFTER DAYBREAK AS A SURFACE HIGH
CENTERED OVER FLORIDA DOMINATES THE WEATHER. THE COASTAL TERMINALS
WILL LIKELY SEE A SOUTH SOUTHWEST MARINE SEABREEZE THIS AFTERNOON...
PERHAPS WITH SOME 15-18 KT GUSTS AT MYR AND CRE.
EXTENDED OUTLOOK...EXPECT VFR...BUT WITH EXTREMELY HOT TEMPERATURES
EXPECTED THROUGH THE WEEKEND.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 130 AM THURSDAY...NO SIGNIFICANT CHANGES TO THE FORECAST AS
WIND/SEA OBSERVATIONS MATCH THE LAST FORECAST. PREVIOUS DISCUSSION
FROM 1000 PM FOLLOWS...
SMALL CRAFT EXERCISE CAUTION ONLY IN EFFECT FOR THE SOUTHERNMOST
WATERS FROM SOUTH OF MURRELLS INLET TO SOUTH SANTEE RIVER UNTIL 3 AM
THU. LATEST BUOY AND COASTAL OBSERVATIONS INDICATE WINDS DIMINISHING
NICELY IN CONCERT WITH THE LATEST HOURLY HRRR MODEL DATA. EXPECT
NE-E WINDS TO DROP TO N AROUND 10 KT OVERNIGHT...AS A RESULT OF THE
SFC PG RELAXING DUE TO THE SFC RIDGE AXIS EXTENDING FROM ITS CENTER
OVER GA...MIGRATING ACROSS THE IMMEDIATE COAST. THERE IS A
POSSIBILITY OF A WEAK LAND BREEZE NEAR SHORE...WITH WINDS FROM THE
NW 5 TO 10 KT. SIGNIFICANT SEAS IN THE 2 TO 5 FT RANGE WILL DIMINISH
TO 2 TO 4 FT THROUGHOUT DURING THE OVERNIGHT. THE LOCALLY PRODUCED
WIND WAVE PORTION OF THE SIG SEAS WILL LOWER BUT THE S TO SE SWELL
COMPONENT FROM WHATS LEFT OF DEBBY WILL CONTINUE. DOMINANT OVERNIGHT
PERIODS WILL RUN AT 6 TO 8 SECONDS.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...EXPECT SW FLOW OF 15 KT OR LESS THROUGH
FRIDAY EVENING BEFORE WINDS SHIFT TO THE NW AND BECOME LIGHT FRIDAY
NIGHT. SEAS HEIGHTS OF 2 TO 4 FEET ARE EXPECTED THROUGH THE
PERIOD.
LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 3 PM WEDNESDAY...NO MAJOR HAZARDS ANTICIPATED ALTHOUGH AIR
TEMPS WILL BE VERY HOT THIS WEEKEND AND PLENTY FRESH WATER WILL BE
CRUCIAL FOR BOATING AND RECREATIONAL EXCURSIONS. SEAS WILL LIKELY
HOLD 4 FEET OR LESS SATURDAY THROUGH MONDAY...ALTHOUGH GROWING SE
WAVES OF 4-5 FEET MAY BE OBSERVED OVER THE FAR OUTER WATERS AS DEBBY
PASSES WELL E OF THE COAST. EACH AFTERNOON THE SEA BREEZE WILL BRING
S-SW WIND GUSTS TO 20 KT DUE TO THE STRONG LAND VS SEA-SFC
TEMPERATURE DIFFERENCE. THE SEA SPECTRUM SAT-MON WILL BE COMPRISED
OF SE WAVES 2-3 FT AT 7-9 SECONDS...AND SW WAVES 1-2 FT AT 4-5
SECONDS DRIVEN MAINLY BY LOCAL WINDS. TSTMS IF ANY WILL REMAIN
ISOLATED...AND MAINLY ON LAND IN THE LATE AFTERNOONS AND WELL
OFFSHORE AT NIGHT. PRESSURE PATTERN SAT-MON WILL FOSTER SW WINDS
10-15 KT...HIGHER GUSTS BETWEEN 3PM-7PM IN-SHORE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...EXCESSIVE HEAT WATCH FROM FRIDAY AFTERNOON THROUGH SATURDAY
AFTERNOON FOR SCZ017-023-024-032-033-039-053>056.
NC...EXCESSIVE HEAT WATCH FROM FRIDAY AFTERNOON THROUGH SATURDAY
AFTERNOON FOR NCZ087-096-099-105>110.
MARINE...NONE.
&&
$$
NEAR TERM...DCH/TRA
SHORT TERM...RAN
LONG TERM...MJC
AVIATION...HDL/TRA
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1104 PM CDT FRI JUN 29 2012
.DISCUSSION.../ISSUED AT 905 PM CDT/
CLUSTER OF THUNDERSTORMS THAT FIRED THIS AFTERNOON AND EARLY EVENING
ACROSS FAR EAST CENTRAL SOUTH DAKOTA AND SOUTHWEST MINNESOTA AS THE
MID LEVEL WAVE INTERSECTED A STALLED OUTFLOW BOUNDARY HAVE RAPIDLY
FALLEN APART AT OUR NORTHEAST BORDER AS THEY MOVE INTO A LESS
FAVORABLE ENVIRONMENT. SECONDARY AREA OF SCATTERED HIGH BASED
THUNDERSTORMS WHICH HAVE DEVELOPED ALONG THE MID LEVEL FRONT HAVE
DIPPED SOUTH FROM NORTHEAST SOUTH DAKOTA AND WILL CONTINUE TO TRACK
SOUTHEASTWARD INTO THE EARLY MORNING HOURS...LIKELY WEAKENING WITH
THE LOSS OF DAYTIME HEATING. SEVERE POTENTIAL WITH THESE STORMS
REMAINS QUITE CONDITIONAL...HOWEVER IT IS NOT OUT OF THE QUESTION.
UPDATED POPS AND SKY COVERAGE TO FOLLOW THE SOUTHEAST TRACK OF THE
CONVECTION IN OUR NORTH AS WELL AS HOURLY TEMPERATURES WHICH HAVE
BEEN GREATLY IMPACTED BY CONVECTION. UPDATES ARE OUT.
&&
.AVIATION.../FOR THE 06Z TAF ISSUANCE/
OVERALL...VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THE PERIOD.
LINGERING NON SEVERE CONVECTION WILL SHIFT SOUTHEAST AND DIMINISH
THROUGH 08Z. SKIES CLEARING BEHIND CONVECTION...AND WITH RAINFALL
FROM THIS MORNING AND LIGHT EASTERLY WINDS...KSUX AREA WILL LIKELY
GET SOME MVFR VISIBILITIES LATE NIGHT AND EARLY MORNING IN FOG.
/CHAPMAN
&&
.PREV DISCUSSION.../ISSUED AT 349 PM CDT/
SCATTERED THUNDERSTORMS ARE POSSIBLE THROUGH EARLY EVENING MAINLY
EAST OF THE JAMES RIVER AS UPPER LEVEL WAVE PIVOTS THROUGH THE
REGION. HRRR OUTPUT SHOWS A DIURNAL TREND AND EXPECT POTENTIAL FOR
CONVECTION TO WANE THROUGH THE EVENING HOURS. MILD AIRMASS REMAINS
ACROSS THE AREA OVERNIGHT INTO THE WEEKEND AND DID NOT ALTER LOW
TEMPERATURES TONIGHT OR HIGHS TOMORROW. NAM AND GFS DISAGREE ON
TIMING OF WAVE TOMORROW...BUT WITH NAM NOT EVEN HANDLING CURRENT
SITUATION AND TIMING WELL...SIDED CLOSER TO GFS AND ECMWF. STILL
UNSURE WHETHER WAVE WILL INDUCE ANY CONVECTION...BUT IF IT DOES
SO...BEST CHANCES APPEAR TO BE LATE INT HE DAY ACROSS CENTRAL SOUTH
DAKOTA...PUSHING EAST THROUGH THE EVENING HOURS.
ON SATURDAY NIGHT...THE WAVE WILL CONTINUE TO MOVE TO THE SOUTHEAST.
WITH THE SURFACE BOUNDARY CLOSER TO I80 YET...THE BEST CHANCE OF
CONVECTION LOOKS TO BE CONFINED TO SOUTH OF I90 AND IS MOST LIKELY
THROUGH 06Z. THE WAVES SHOULD MOVE SOUTH SO ANY LINGERING
THUNDERSTORMS WILL GRADUALLY EXIT THE AREA AFTER 06Z. WITH ALL OF
THE MOISTURE...LOWS WILL REMAIN IN THE UPPER 60S TO LOWER 70S.
ANOTHER WAVE IS FORECAST BY ALL MODELS TO MOVE ACROSS NORTHERN
NEBRASKA AS THE SURFACE BOUNDARY SLOWLY MOVES NORTHWARD ON SUNDAY.
IT REMAINS FAIRLY WARM ALOFT SO THERE IS A STRONG CAPPING INVERSION
AS THE WAVE APPROACHES AND IT WILL BE TOUGH TO GET CONVECTION TO
DEVELOP. HOWEVER...WITH A BOUNDARY AND UPPER WAVE...DID ADD A SLIGHT
CHANCE OF THUNDERSTORMS FOR SUNDAY AFTERNOON AND EVENING SOUTH OF
I90. SINCE CONVECTION LOOKS TO HOLD OFF UNTIL LATE
AFTERNOON...SHOULD BE SUNNY TO PARTLY CLOUDY SKIES MOST OF THE DAY
SO HIGHS SHOULD RISE INTO THE 90S EVERYWHERE BUT THE BUFFALO RIDGE
WHICH WILL HOLD IN THE 80S.
AFTER SUNDAY EVENING...THERE REALLY LOOKS LIKE NO ORGANIZED CHANCE
FOR PRECIPITATION AND A STRONG 500 MB RIDGE BUILDS OVER THE
CENTRAL US FOR ALL OF NEXT WEEK. THIS CARRIES MOST UPPER WAVES OVER
ND AND NORTHERN MN. WHILE IT IS NOT IMPOSSIBLE THAT A ROGUE STORM
COULD FORM EITHER MONDAY NIGHT OR WEDNESDAY IN SW MN...THE CHANCE IS
SO SMALL THAT HAVE GONE DRY FROM LATE SUNDAY NIGHT THROUGH FRIDAY.
OTHERWISE...THE SURFACE WIND WILL VARY FROM EAST TO SOUTH-SOUTHEAST
THROUGH THE PERIOD AT THE SURFACE WITH SW FLOW ABOVE 900 MB. THIS
WILL CONTINUE TO BRING VERY WARM AND HUMID AIR INTO THE ENTIRE
REGION. BASICALLY HAVE HIGHS FROM THE LOWER TO MID 90S ALONG AND
EAST OF I29 TO AROUND 102 IN SOUTH CENTRAL SD. THERE IS CERTAINLY
THE POTENTIAL THAT ONE OR TWO OF THESE DAYS COULD BE EVEN WARMER
THAN FORECAST BUT THAT WILL BE DEPENDENT ON IF WIND DIRECTION CAN GO
SOUTH OR SOUTHWEST FOR A PERIOD. THE OTHER CONCERN IS THE HUMIDITY.
WITH A STRONG INVERSION...EXPECT THAT MOST PLACES WILL SEE DEW
POINTS IN THE UPPER 60S TO MID 70S EACH DAY WITH THE HIGHEST DEW
POINTS EAST OF THE JAMES RIVER. ONLY SOUTH CENTRAL SOUTH DAKOTA
COULD SEE DEW POINTS FALL INTO THE LOWER 60S...OR EVEN LOWER...IF
TEMPERATURES RISE WELL ABOVE 100 DEGREES. THE COMBINATION OF HEAT
AND HUMIDITY WILL RESULT IN HEAT INDICES BETWEEN 100 AND 110 EACH
AFTERNOON. WE ARE ALSO EXPECTING LOWS IN THE LOW TO MID 70S EACH
DAY...AND A DAY OR TWO WITH LOWS NEAR 80 ARE ALSO NOT IMPOSSIBLE.
THIS WILL LIKELY RESULT IN A PROLONGED PERIOD OF DANGEROUS HEAT NEXT
WEEK. /SCHUMACHER
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...NONE.
NE...NONE.
SD...NONE.
&&
$$
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
905 PM CDT FRI JUN 29 2012
.DISCUSSION.../ISSUED AT 905 PM CDT/
CLUSTER OF THUNDERSTORMS THAT FIRED THIS AFTERNOON AND EARLY EVENING
ACROSS FAR EAST CENTRAL SOUTH DAKOTA AND SOUTHWEST MINNESOTA AS THE
MID LEVEL WAVE INTERSECTED A STALLED OUTFLOW BOUNDARY HAVE RAPIDLY
FALLEN APART AT OUR NORTHEAST BORDER AS THEY MOVE INTO A LESS
FAVORABLE ENVIRONMENT. SECONDARY AREA OF SCATTERED HIGH BASED
THUNDERSTORMS WHICH HAVE DEVELOPED ALONG THE MID LEVEL FRONT HAVE
DIPPED SOUTH FROM NORTHEAST SOUTH DAKOTA AND WILL CONTINUE TO TRACK
SOUTHEASTWARD INTO THE EARLY MORNING HOURS...LIKELY WEAKENING WITH
THE LOSS OF DAYTIME HEATING. SEVERE POTENTIAL WITH THESE STORMS
REMAINS QUITE CONDITIONAL...HOWEVER IT IS NOT OUT OF THE QUESTION.
UPDATED POPS AND SKY COVERAGE TO FOLLOW THE SOUTHEAST TRACK OF THE
CONVECTION IN OUR NORTH AS WELL AS HOURLY TEMPERATURES WHICH HAVE
BEEN GREATLY IMPACTED BY CONVECTION. UPDATES ARE OUT.
&&
.AVIATION.../FOR THE 00Z TAF ISSUANCE/
OVERALL...VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THE PERIOD.
CONVECTION ACROSS EAST CENTRAL SOUTH DAKOTA AND SOUTHWEST MINNESOTA
WILL SHIFT EAST CREATING A CHANCE OF SHOWERS AND THUNDERSTORMS
NORTHEAST OF A DE SMET TO JACKSON MINNESOTA LINE THIS EVENING.
VISIBILITIES MAY BRIEFLY FALL TO AROUND 2-3SM WITHIN THE CORE OF
THUNDERSTORMS...THOUGH CEILINGS SHOULD REMAIN VFR. SKIES CLEARING
BEHIND CONVECTION...AND WITH RAINFALL FROM THIS MORNING AND LIGHT
EASTERLY WINDS...KSUX AREA WILL LIKELY GET SOME MVFR VISIBILITIES
LATE NIGHT AND EARLY MORNING IN FOG. /CHAPMAN
&&
.PREV DISCUSSION.../ISSUED AT 349 PM CDT/
SCATTERED THUNDERSTORMS ARE POSSIBLE THROUGH EARLY EVENING MAINLY
EAST OF THE JAMES RIVER AS UPPER LEVEL WAVE PIVOTS THROUGH THE
REGION. HRRR OUTPUT SHOWS A DIURNAL TREND AND EXPECT POTENTIAL FOR
CONVECTION TO WANE THROUGH THE EVENING HOURS. MILD AIRMASS REMAINS
ACROSS THE AREA OVERNIGHT INTO THE WEEKEND AND DID NOT ALTER LOW
TEMPERATURES TONIGHT OR HIGHS TOMORROW. NAM AND GFS DISAGREE ON
TIMING OF WAVE TOMORROW...BUT WITH NAM NOT EVEN HANDLING CURRENT
SITUATION AND TIMING WELL...SIDED CLOSER TO GFS AND ECMWF. STILL
UNSURE WHETHER WAVE WILL INDUCE ANY CONVECTION...BUT IF IT DOES
SO...BEST CHANCES APPEAR TO BE LATE INT HE DAY ACROSS CENTRAL SOUTH
DAKOTA...PUSHING EAST THROUGH THE EVENING HOURS.
ON SATURDAY NIGHT...THE WAVE WILL CONTINUE TO MOVE TO THE SOUTHEAST.
WITH THE SURFACE BOUNDARY CLOSER TO I80 YET...THE BEST CHANCE OF
CONVECTION LOOKS TO BE CONFINED TO SOUTH OF I90 AND IS MOST LIKELY
THROUGH 06Z. THE WAVES SHOULD MOVE SOUTH SO ANY LINGERING
THUNDERSTORMS WILL GRADUALLY EXIT THE AREA AFTER 06Z. WITH ALL OF
THE MOISTURE...LOWS WILL REMAIN IN THE UPPER 60S TO LOWER 70S.
ANOTHER WAVE IS FORECAST BY ALL MODELS TO MOVE ACROSS NORTHERN
NEBRASKA AS THE SURFACE BOUNDARY SLOWLY MOVES NORTHWARD ON SUNDAY.
IT REMAINS FAIRLY WARM ALOFT SO THERE IS A STRONG CAPPING INVERSION
AS THE WAVE APPROACHES AND IT WILL BE TOUGH TO GET CONVECTION TO
DEVELOP. HOWEVER...WITH A BOUNDARY AND UPPER WAVE...DID ADD A SLIGHT
CHANCE OF THUNDERSTORMS FOR SUNDAY AFTERNOON AND EVENING SOUTH OF
I90. SINCE CONVECTION LOOKS TO HOLD OFF UNTIL LATE
AFTERNOON...SHOULD BE SUNNY TO PARTLY CLOUDY SKIES MOST OF THE DAY
SO HIGHS SHOULD RISE INTO THE 90S EVERYWHERE BUT THE BUFFALO RIDGE
WHICH WILL HOLD IN THE 80S.
AFTER SUNDAY EVENING...THERE REALLY LOOKS LIKE NO ORGANIZED CHANCE
FOR PRECIPITATION AND A STRONG 500 MB RIDGE BUILDS OVER THE
CENTRAL US FOR ALL OF NEXT WEEK. THIS CARRIES MOST UPPER WAVES OVER
ND AND NORTHERN MN. WHILE IT IS NOT IMPOSSIBLE THAT A ROGUE STORM
COULD FORM EITHER MONDAY NIGHT OR WEDNESDAY IN SW MN...THE CHANCE IS
SO SMALL THAT HAVE GONE DRY FROM LATE SUNDAY NIGHT THROUGH FRIDAY.
OTHERWISE...THE SURFACE WIND WILL VARY FROM EAST TO SOUTH-SOUTHEAST
THROUGH THE PERIOD AT THE SURFACE WITH SW FLOW ABOVE 900 MB. THIS
WILL CONTINUE TO BRING VERY WARM AND HUMID AIR INTO THE ENTIRE
REGION. BASICALLY HAVE HIGHS FROM THE LOWER TO MID 90S ALONG AND
EAST OF I29 TO AROUND 102 IN SOUTH CENTRAL SD. THERE IS CERTAINLY
THE POTENTIAL THAT ONE OR TWO OF THESE DAYS COULD BE EVEN WARMER
THAN FORECAST BUT THAT WILL BE DEPENDENT ON IF WIND DIRECTION CAN GO
SOUTH OR SOUTHWEST FOR A PERIOD. THE OTHER CONCERN IS THE HUMIDITY.
WITH A STRONG INVERSION...EXPECT THAT MOST PLACES WILL SEE DEW
POINTS IN THE UPPER 60S TO MID 70S EACH DAY WITH THE HIGHEST DEW
POINTS EAST OF THE JAMES RIVER. ONLY SOUTH CENTRAL SOUTH DAKOTA
COULD SEE DEW POINTS FALL INTO THE LOWER 60S...OR EVEN LOWER...IF
TEMPERATURES RISE WELL ABOVE 100 DEGREES. THE COMBINATION OF HEAT
AND HUMIDITY WILL RESULT IN HEAT INDICES BETWEEN 100 AND 110 EACH
AFTERNOON. WE ARE ALSO EXPECTING LOWS IN THE LOW TO MID 70S EACH
DAY...AND A DAY OR TWO WITH LOWS NEAR 80 ARE ALSO NOT IMPOSSIBLE.
THIS WILL LIKELY RESULT IN A PROLONGED PERIOD OF DANGEROUS HEAT NEXT
WEEK. /SCHUMACHER
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...NONE.
NE...NONE.
SD...NONE.
&&
$$
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
656 PM CDT FRI JUN 29 2012
.DISCUSSION.../ISSUED AT 349 PM CDT/
SCATTERED THUNDERSTORMS ARE POSSIBLE THROUGH EARLY EVENING MAINLY
EAST OF THE JAMES RIVER AS UPPER LEVEL WAVE PIVOTS THROUGH THE
REGION. HRRR OUTPUT SHOWS A DIURNAL TREND AND EXPECT POTENTIAL FOR
CONVECTION TO WANE THROUGH THE EVENING HOURS. MILD AIRMASS REMAINS
ACROSS THE AREA OVERNIGHT INTO THE WEEKEND AND DID NOT ALTER LOW
TEMPERATURES TONIGHT OR HIGHS TOMORROW. NAM AND GFS DISAGREE ON
TIMING OF WAVE TOMORROW...BUT WITH NAM NOT EVEN HANDLING CURRENT
SITUATION AND TIMING WELL...SIDED CLOSER TO GFS AND ECMWF. STILL
UNSURE WHETHER WAVE WILL INDUCE ANY CONVECTION...BUT IF IT DOES
SO...BEST CHANCES APPEAR TO BE LATE INT HE DAY ACROSS CENTRAL SOUTH
DAKOTA...PUSHING EAST THROUGH THE EVENING HOURS.
ON SATURDAY NIGHT...THE WAVE WILL CONTINUE TO MOVE TO THE SOUTHEAST.
WITH THE SURFACE BOUNDARY CLOSER TO I80 YET...THE BEST CHANCE OF
CONVECTION LOOKS TO BE CONFINED TO SOUTH OF I90 AND IS MOST LIKELY
THROUGH 06Z. THE WAVES SHOULD MOVE SOUTH SO ANY LINGERING
THUNDERSTORMS WILL GRADUALLY EXIT THE AREA AFTER 06Z. WITH ALL OF
THE MOISTURE...LOWS WILL REMAIN IN THE UPPER 60S TO LOWER 70S.
ANOTHER WAVE IS FORECAST BY ALL MODELS TO MOVE ACROSS NORTHERN
NEBRASKA AS THE SURFACE BOUNDARY SLOWLY MOVES NORTHWARD ON SUNDAY.
IT REMAINS FAIRLY WARM ALOFT SO THERE IS A STRONG CAPPING INVERSION
AS THE WAVE APPROACHES AND IT WILL BE TOUGH TO GET CONVECTION TO
DEVELOP. HOWEVER...WITH A BOUNDARY AND UPPER WAVE...DID ADD A SLIGHT
CHANCE OF THUNDERSTORMS FOR SUNDAY AFTERNOON AND EVENING SOUTH OF
I90. SINCE CONVECTION LOOKS TO HOLD OFF UNTIL LATE
AFTERNOON...SHOULD BE SUNNY TO PARTLY CLOUDY SKIES MOST OF THE DAY
SO HIGHS SHOULD RISE INTO THE 90S EVERYWHERE BUT THE BUFFALO RIDGE
WHICH WILL HOLD IN THE 80S.
AFTER SUNDAY EVENING...THERE REALLY LOOKS LIKE NO ORGANIZED CHANCE
FOR PRECIPITATION AND A STRONG 500 MB RIDGE BUILDS OVER THE
CENTRAL US FOR ALL OF NEXT WEEK. THIS CARRIES MOST UPPER WAVES OVER
ND AND NORTHERN MN. WHILE IT IS NOT IMPOSSIBLE THAT A ROGUE STORM
COULD FORM EITHER MONDAY NIGHT OR WEDNESDAY IN SW MN...THE CHANCE IS
SO SMALL THAT HAVE GONE DRY FROM LATE SUNDAY NIGHT THROUGH FRIDAY.
OTHERWISE...THE SURFACE WIND WILL VARY FROM EAST TO SOUTH-SOUTHEAST
THROUGH THE PERIOD AT THE SURFACE WITH SW FLOW ABOVE 900 MB. THIS
WILL CONTINUE TO BRING VERY WARM AND HUMID AIR INTO THE ENTIRE
REGION. BASICALLY HAVE HIGHS FROM THE LOWER TO MID 90S ALONG AND
EAST OF I29 TO AROUND 102 IN SOUTH CENTRAL SD. THERE IS CERTAINLY
THE POTENTIAL THAT ONE OR TWO OF THESE DAYS COULD BE EVEN WARMER
THAN FORECAST BUT THAT WILL BE DEPENDENT ON IF WIND DIRECTION CAN GO
SOUTH OR SOUTHWEST FOR A PERIOD. THE OTHER CONCERN IS THE HUMIDITY.
WITH A STRONG INVERSION...EXPECT THAT MOST PLACES WILL SEE DEW
POINTS IN THE UPPER 60S TO MID 70S EACH DAY WITH THE HIGHEST DEW
POINTS EAST OF THE JAMES RIVER. ONLY SOUTH CENTRAL SOUTH DAKOTA
COULD SEE DEW POINTS FALL INTO THE LOWER 60S...OR EVEN LOWER...IF
TEMPERATURES RISE WELL ABOVE 100 DEGREES. THE COMBINATION OF HEAT
AND HUMIDITY WILL RESULT IN HEAT INDICES BETWEEN 100 AND 110 EACH
AFTERNOON. WE ARE ALSO EXPECTING LOWS IN THE LOW TO MID 70S EACH
DAY...AND A DAY OR TWO WITH LOWS NEAR 80 ARE ALSO NOT IMPOSSIBLE.
THIS WILL LIKELY RESULT IN A PROLONGED PERIOD OF DANGEROUS HEAT NEXT
WEEK. /SCHUMACHER
&&
.AVIATION.../FOR THE 00Z TAF ISSUANCE/
OVERALL...VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THE PERIOD.
CONVECTION ACROSS EAST CENTRAL SOUTH DAKOTA AND SOUTHWEST MINNESOTA
WILL SHIFT EAST CREATING A CHANCE OF SHOWERS AND THUNDERSTORMS
NORTHEAST OF A DE SMET TO JACKSON MINNESOTA LINE THIS EVENING.
VISIBILITIES MAY BRIEFLY FALL TO AROUND 2-3SM WITHIN THE CORE OF
THUNDERSTORMS...THOUGH CEILINGS SHOULD REMAIN VFR. SKIES CLEARING
BEHIND CONVECTION...AND WITH RAINFALL FROM THIS MORNING AND LIGHT
EASTERLY WINDS...KSUX AREA WILL LIKELY GET SOME MVFR VISIBILITIES
LATE NIGHT AND EARLY MORNING IN FOG. /CHAPMAN
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...NONE.
NE...NONE.
SD...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1100 PM CDT FRI JUN 29 2012
.SHORT TERM...TODAY THROUGH MONDAY
257 PM CDT FRI JUN 29 2012
FORECAST CONCERN THROUGH THE SHORT TERM MAINLY FOCUSED ON
SHOWER/THUNDERSTORM CHANCES.
CURRENT WATER VAPOR SNAPSHOT/RAP 500MB ANALYSIS HAS TWO MID-LEVEL
SHORTWAVE TROUGHS ROTATING EASTWARD ACROSS SOUTHWEST MN/WESTERN IA.
QUASI-STATIONARY FRONTAL BOUNDARY WAS LAID UP FROM EASTERN
NEB/ACROSS CENTRAL IA...TO NEAR CHAMPAIGN IL. VIGOROUS SHRA/TS
DEVELOPMENT AHEAD OF THESE SHORTWAVE TROUGHS IN LIFT AND ALONG
FRONTAL BOUNDARY WHERE 5000-7000J/KG 0-1KM MUCAPE POOL EXISTS. RADAR
MOSAIC SHOWING NORTHERN/DEFORMATION AREA OF SHORTWAVE CONVECTION
NICKING PORTIONS OF NORTHEAST IOWA.
29.12Z NCEP MODELS/29.09Z SREF STILL SHOWING DIFFERING
INTENSITIES/SPEED OF VARIOUS SHORTWAVE TROUGHS INTERACTING WITH THE
QUASI-STATIONARY FRONT THROUGH THE PERIOD. GFS SEEMS TO HAVE
INITIALIZED BETTER AT 18Z COMPARED TO THE NAM. WEIGHTED FORECAST
SLIGHTLY TOWARD THE GFS SOLUTION WITH BETTER
INITIALIZATION...BLENDED WITH A MODEL CONSENSUS.
FOR TONIGHT...WILL BE WATCHING THE SHORTWAVE TROUGH/S CONTINUE TO
ROTATE EAST ACROSS IA INTO IL...INTERACTING WITH THE FRONTAL
BOUNDARY TO OUR SOUTH. AREAS SOUTH OF I-90 WILL REMAIN SUSCEPTIBLE
TO NORTHERN EXTENT OF CONVECTION WITH THE BEST CHANCE OF SHOWERS AND
THUNDERSTORMS SOUTH OF A LINE FROM CHARLES CITY IA THROUGH PRAIRIE
DU CHIEN AND PLATTEVILLE WI. THERE IS THE POSSIBILITY A FEW OF THESE
STORMS ACROSS NORTHEAST IA INTO FAR SOUTHWEST WI COULD BE SEVERE
WITH DAMAGING WIND BEING THE MAIN THREAT.
FRONTAL BOUNDARY REMAINS IN PLACE TO OUR SOUTH THROUGH SUNDAY WITH
MUDDLED NORTHWEST FLOW USHERING IN A FEW MID-LEVEL SHORTWAVE
TROUGHS. TIMING AND INTENSITIES OF THESE WAVES STILL A BIT UNCLEAR
WITH DIFFERING OPINIONS BETWEEN THE MODELS. BASED ON THIS
SIGNAL...WENT MORE WITH A MODEL CONSENSUS BLEND FOR
SHOWER/THUNDERSTORM PROBABILITIES WHICH YIELDS LOW-END CHANCES SOUTH
OF I-90 SATURDAY...AND ACROSS THE ENTIRE AREA SATURDAY NIGHT THROUGH
SUNDAY AS THE FRONTAL BOUNDARY STARTS A SLOW SHIFT NORTHWARD TOWARD
THE AREA.
FOR SUNDAY NIGHT THROUGH MONDAY...LOOK FOR A WARM FRONT TO PUSH
NORTHWARD INTO THE AREA. MODELS SHOW LARGE/WEAK MOISTURE 850MB
MOISTURE TRANSPORT AHEAD OF THE FRONT WITH INCREASING ISENTROPIC
LIFT. ON MONDAY...NAM SHOWS 0-1KM MUCAPE CREEPING UP INTO THE
2500-5000J/KG RANGE WHILE THE GFS INDICATES 4500-6500J/KG AS PW/S
INCREASE INTO THE 1.5-2.0 INCH RANGE. AS SUCH...INCREASED
SHOWER/THUNDERSTORM CHANCES INTO MID-RANGE //40 PERCENT// TERRITORY.
TEMPERATURE-WISE...TEMPERATURES ARE EXPECTED TO REMAIN ABOVE NORMAL
THROUGH MONDAY WITH HIGHS IN THE 80S TO LOWER 90S. LOOK FOR HEAT
INDICES TO INCREASE INTO THE UPPER 90S BY MONDAY WITH INCREASING
HUMIDITY LEVELS.
.LONG TERM...TUESDAY THROUGH FRIDAY
257 PM CDT FRI JUN 29 2012
LATEST GFS/ECMWF SHOW RIDGE BUILDING OVER THE CENTRAL CONUS/UPPER
MISSISSIPPI RIVER VALLEY REGION THROUGH THE PERIOD WITH SEVERAL WEAK
MID-LEVEL SHORTWAVES TRYING TO PENETRATE THROUGH. BASED ON THIS
MUDDLED SHORTWAVE RESOLUTION...WENT WITH MODEL CONSENSUS WHICH
YIELDS LOW-END PERIODIC SHOWER/THUNDERSTORM CHANCES THROUGH THE
PERIOD. ABOVE NORMAL TEMPERATURES LOOK TO CONTINUE WITH HIGHS IN THE
MID/UPPER 80S TO LOWER 90S.
&&
.AVIATION...
1100 PM CDT FRI JUN 29 2012
CONVECTION CONTINUES TO FIRE ALONG A NORTH-SOUTH RUNNING SFC FRONT
ACROSS EASTERN IA/NORTHERN ILL...AIDED BY A PUSH OF LOW LEVEL
MOISTURE AND AN UPPER LEVEL SHORTWAVE. THIS ACTIVITY SHOULD CONTINUE
TO MOVE EAST...AVOIDING THE TAF SITES.
MEANWHILE OVER SD/SOUTHWEST MN...SHRA/TS CONTINUED TO
DEVELOP...PRESSING SOUTHEAST...ASSOCIATED WITH AN UPPER LEVEL
DISTURBANCE. THE LATEST HRRR CAPTURES THIS CONVECTION...AND
CONTINUES ITS SOUTHEAST MOVEMENT...TOWARD THE FRONT AND AWAY FROM
THE RELATIVELY DRIER AIR EAST OF IT. LATEST RAP AND 18Z NAM12 FAVOR
THIS TOO. SO...WILL CONTINUE WITH A DRY FORECAST FOR THE TAFS
OVERNIGHT.
SO...PERIODS OF HIGH CLOUDINESS ARE EXPECTED FOR KRST/KLSE...
RESULTING IN VFR CONDITIONS. WINDS WILL CONTINUE TO SHOW SOME
VARIABILITY IN DIRECTION...ESPECIALLY AT NIGHT...AS THE PRESSURE
GRADIENT REMAINS WEAK.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
257 PM CDT FRI JUN 29 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM....DAS
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
630 PM CDT FRI JUN 29 2012
.SHORT TERM...TODAY THROUGH MONDAY
257 PM CDT FRI JUN 29 2012
FORECAST CONCERN THROUGH THE SHORT TERM MAINLY FOCUSED ON
SHOWER/THUNDERSTORM CHANCES.
CURRENT WATER VAPOR SNAPSHOT/RAP 500MB ANALYSIS HAS TWO MID-LEVEL
SHORTWAVE TROUGHS ROTATING EASTWARD ACROSS SOUTHWEST MN/WESTERN IA.
QUASI-STATIONARY FRONTAL BOUNDARY WAS LAID UP FROM EASTERN
NEB/ACROSS CENTRAL IA...TO NEAR CHAMPAIGN IL. VIGOROUS SHRA/TS
DEVELOPMENT AHEAD OF THESE SHORTWAVE TROUGHS IN LIFT AND ALONG
FRONTAL BOUNDARY WHERE 5000-7000J/KG 0-1KM MUCAPE POOL EXISTS. RADAR
MOSAIC SHOWING NORTHERN/DEFORMATION AREA OF SHORTWAVE CONVECTION
NICKING PORTIONS OF NORTHEAST IOWA.
29.12Z NCEP MODELS/29.09Z SREF STILL SHOWING DIFFERING
INTENSITIES/SPEED OF VARIOUS SHORTWAVE TROUGHS INTERACTING WITH THE
QUASI-STATIONARY FRONT THROUGH THE PERIOD. GFS SEEMS TO HAVE
INITIALIZED BETTER AT 18Z COMPARED TO THE NAM. WEIGHTED FORECAST
SLIGHTLY TOWARD THE GFS SOLUTION WITH BETTER
INITIALIZATION...BLENDED WITH A MODEL CONSENSUS.
FOR TONIGHT...WILL BE WATCHING THE SHORTWAVE TROUGH/S CONTINUE TO
ROTATE EAST ACROSS IA INTO IL...INTERACTING WITH THE FRONTAL
BOUNDARY TO OUR SOUTH. AREAS SOUTH OF I-90 WILL REMAIN SUSCEPTIBLE
TO NORTHERN EXTENT OF CONVECTION WITH THE BEST CHANCE OF SHOWERS AND
THUNDERSTORMS SOUTH OF A LINE FROM CHARLES CITY IA THROUGH PRAIRIE
DU CHIEN AND PLATTEVILLE WI. THERE IS THE POSSIBILITY A FEW OF THESE
STORMS ACROSS NORTHEAST IA INTO FAR SOUTHWEST WI COULD BE SEVERE
WITH DAMAGING WIND BEING THE MAIN THREAT.
FRONTAL BOUNDARY REMAINS IN PLACE TO OUR SOUTH THROUGH SUNDAY WITH
MUDDLED NORTHWEST FLOW USHERING IN A FEW MID-LEVEL SHORTWAVE
TROUGHS. TIMING AND INTENSITIES OF THESE WAVES STILL A BIT UNCLEAR
WITH DIFFERING OPINIONS BETWEEN THE MODELS. BASED ON THIS
SIGNAL...WENT MORE WITH A MODEL CONSENSUS BLEND FOR
SHOWER/THUNDERSTORM PROBABILITIES WHICH YIELDS LOW-END CHANCES SOUTH
OF I-90 SATURDAY...AND ACROSS THE ENTIRE AREA SATURDAY NIGHT THROUGH
SUNDAY AS THE FRONTAL BOUNDARY STARTS A SLOW SHIFT NORTHWARD TOWARD
THE AREA.
FOR SUNDAY NIGHT THROUGH MONDAY...LOOK FOR A WARM FRONT TO PUSH
NORTHWARD INTO THE AREA. MODELS SHOW LARGE/WEAK MOISTURE 850MB
MOISTURE TRANSPORT AHEAD OF THE FRONT WITH INCREASING ISENTROPIC
LIFT. ON MONDAY...NAM SHOWS 0-1KM MUCAPE CREEPING UP INTO THE
2500-5000J/KG RANGE WHILE THE GFS INDICATES 4500-6500J/KG AS PW/S
INCREASE INTO THE 1.5-2.0 INCH RANGE. AS SUCH...INCREASED
SHOWER/THUNDERSTORM CHANCES INTO MID-RANGE //40 PERCENT// TERRITORY.
TEMPERATURE-WISE...TEMPERATURES ARE EXPECTED TO REMAIN ABOVE NORMAL
THROUGH MONDAY WITH HIGHS IN THE 80S TO LOWER 90S. LOOK FOR HEAT
INDICES TO INCREASE INTO THE UPPER 90S BY MONDAY WITH INCREASING
HUMIDITY LEVELS.
.LONG TERM...TUESDAY THROUGH FRIDAY
257 PM CDT FRI JUN 29 2012
LATEST GFS/ECMWF SHOW RIDGE BUILDING OVER THE CENTRAL CONUS/UPPER
MISSISSIPPI RIVER VALLEY REGION THROUGH THE PERIOD WITH SEVERAL WEAK
MID-LEVEL SHORTWAVES TRYING TO PENETRATE THROUGH. BASED ON THIS
MUDDLED SHORTWAVE RESOLUTION...WENT WITH MODEL CONSENSUS WHICH
YIELDS LOW-END PERIODIC SHOWER/THUNDERSTORM CHANCES THROUGH THE
PERIOD. ABOVE NORMAL TEMPERATURES LOOK TO CONTINUE WITH HIGHS IN THE
MID/UPPER 80S TO LOWER 90S.
&&
.AVIATION...
630 PM CDT FRI JUN 29 2012
CONVECTION CONTINUES TO FIRE ALONG A NORTH-SOUTH RUNNING SFC FRONT
ACROSS SOUTHERN IA/NORTHERN ILL...AIDED BY A PUSH OF LOW LEVEL
MOISTURE AND AN UPPER LEVEL SHORTWAVE. SOME RADAR RETURNS NORTH OF
THERE...MORE SHOWERY...BUT NOT MUCH/IF ANY GROUND TRUTH YET VIA
OBSERVATIONS. THIS ACTIVITY SHOULD CONTINUE TO MOVE EAST...AVOIDING
THE TAF SITES.
MEANWHILE OVER SD/SOUTHWEST MN...ANOTHER AREA OF SHRA/TS CONTINUED
TO DEVELOP...PRESSING EAST...ASSOCIATED WITH AN UPPER LEVEL
DISTURBANCE. THE LATEST HRRR CAPTURES THIS CONVECTION...AND WANTS TO
DIVE IT SOUTHEAST...TOWARD THE FRONT AND AWAY FROM THE RELATIVELY
DRIER AIR EAST OF IT. LATEST RAP AND 18Z NAM12 FAVOR THIS TOO.
SO...WILL CONTINUE WITH A DRY FORECAST FOR THE TAFS TONIGHT...BUT
WILL MONITOR AND ADJUST IF NEEDED.
SO...PERIODS OF HIGH CLOUDINESS ARE EXPECTED FOR KRST/KLSE...
RESULTING IN VFR CONDITIONS. WINDS WILL CONTINUE TO SHOW SOME
VARIABILITY IN DIRECTION...ESPECIALLY AT NIGHT...AS THE PRESSURE
GRADIENT REMAINS WEAK.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
257 PM CDT FRI JUN 29 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM....DAS
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
246 AM CDT THU JUN 28 2012
.SHORT TERM...TODAY THROUGH SATURDAY NIGHT
246 AM CDT THU JUN 28 2012
MAIN FORECAST CONCERNS ARE ON HEAT INDEX VALUES TODAY ALONG WITH
SHOWER AND THUNDERSTORM CHANCES. FOCUS THEN TURNS TO TEMPERATURES
AND SHOWER/THUNDERSTORM CHANCES THROUGH THE WEEKEND.
LATEST SURFACE OBSERVATIONS SHOWED A WEAK COLD FRONT EXTENDING
FROM EASTERN LAKE SUPERIOR TO FAR NORTHWEST WISCONSIN...INTO
EXTREME NORTHWEST IOWA...DRIFTING SOUTHEAST.
THE COLD FRONT WILL CONTINUE DRIFTING SOUTHEAST INTO THE FORECAST
AREA TODAY. MEANWHILE...A SHORTWAVE TROUGH IS EXPECTED TO PUSH FROM
WEST TO EAST ACROSS THE REGION. THE SHORTWAVE MAY TRIGGER A FEW
ELEVATED SHOWERS AND THUNDERSTORMS AS IT MOVES THROUGH. THE WAVE IS
ALREADY PRODUCING SOME SCATTERED SHOWERS AND STORMS OVER FAR WESTERN
IOWA AND SOUTHWEST MINNESOTA. NORTHEAST IOWA AND SOUTHEAST MINNESOTA
HAVE THE HIGHEST CHANCES OF SEEING THIS ACTIVITY THIS MORNING. THE
HIGHEST CHANCES FOR SHOWERS AND STORMS THEN SHIFT SOUTH THIS
AFTERNOON ACROSS EXTREME NORTHEAST IOWA INTO FAR SOUTHWEST WISCONSIN.
AFTERNOON MUCAPE VALUES ARE EXPECTED TO INCREASE INTO THE 2500-5500
J/KG RANGE. THESE CAPE VALUES COUPLED WITH 0-6 KM BULK SHEAR OF 40 TO
55 KTS COULD LEAD TO A FEW SEVERE THUNDERSTORMS. THE MAJOR LIMITING
FACTOR WILL BE A STRONG CAP IN PLACE WITH CIN VALUES AROUND NEGATIVE
200 J/KG. IF THE CAP CAN BE BROKEN SEVERE STORMS WOULD BE A
POSSIBILITY. THINKING THE BULK OF THE THUNDERSTORM ACTIVITY WILL BE
ABOVE THE CAP...WITH LIMITED INSTABILITY TO WORK WITH. ANOTHER HOT
AND HUMID DAY IS IN STORE ACROSS PORTIONS OF NORTHEAST IOWA AND FAR
SOUTHWEST WISCONSIN. WILL MAINTAIN HEAT ADVISORY ACROSS THESE AREAS
FROM NOON TO 7 PM. PLAN ON HIGHS RANGING FROM THE UPPER 80S ACROSS
NORTH CENTRAL WISCONSIN TO THE LOWER TO MID 90S ACROSS PORTIONS
NORTHEAST IOWA INTO FAR SOUTHWEST WISCONSIN.
THE FRONTAL BOUNDARY IS EXPECTED TO PUSH INTO CENTRAL IOWA/NORTHERN
ILLINOIS TONIGHT AND WILL BE THE FOCUS FOR SHOWER AND THUNDERSTORM
DEVELOPMENT. WEAK HIGH PRESSURE WILL PUSH INTO THE FORECAST AREA
BEHIND THE BOUNDARY. IT WILL TAKE SOME TIME FOR DRIER AIR TO MOVE IN
WITH DEW POINTS SLOWLY FALLING THROUGH THE AFTERNOON INTO THE
EVENING HOURS. A WEAK SHORTWAVE TROUGH LOOK TO MOVE ACROSS IOWA INTO
NORTHERN ILLINOIS TONIGHT....TRIGGERING SHOWERS AND THUNDERSTORMS. A
FEW OF THESE STORMS COULD EDGE INTO PORTIONS OF NORTHEAST IOWA AND
FAR SOUTHWEST WISCONSIN SO WILL KEEP SHOWER AND THUNDERSTORM CHANCES
ACROSS THESE AREAS. PLAN ON LOWS TONIGHT RANGING FROM THE MID 60S
ACROSS NORTH CENTRAL WISCONSIN TO AROUND 70 OVER NORTHEAST IOWA. THE
UPPER LEVEL RIDGE WILL FLATTEN AND SHIFT EAST OF THE REGION WITH
ZONAL FLOW IN PLACE ACROSS THE REGION TONIGHT INTO EARLY FRIDAY
MORNING.
RATHER WARM AIR WILL REMAIN IN PLACE ACROSS THE REGION
FRIDAY...PERSISTING THROUGH THE WEEKEND. 850 MB TEMPERATURES ONLY
FALL SLIGHTLY BEHIND THE FRONT INTO THE 20 TO 22 C RANGE. 850 MB
TEMPERATURES HOLD NEARLY STEADY THROUGH SATURDAY. WEAK EMBEDDED
SHORTWAVES...MOVING THROUGH THE ZONAL FLOW...WILL INTERACT WITH THE
BOUNDARY FRIDAY THROUGH SATURDAY. THE BOUNDARY TRIES TO LIFT NORTH
SLIGHTLY FRIDAY NIGHT INTO SATURDAY BUT CONVECTION OCCURRING ON THE
NORTHERN FRINGE SHOULD HOLD IT TO THE SOUTH. THE STRONGEST WAVE
LOOKS TO PUSH ACROSS THE REGION SATURDAY NIGHT INTO SUNDAY SO WILL
KEEP THE HIGHEST PRECIPITATION CHANCES DURING THIS TIME FRAME. PLAN
ON CHANCES FOR SHOWERS AND THUNDERSTORMS SATURDAY INTO SUNDAY WITH
HIGHS RANGING FROM THE MID 80S ACROSS NORTHERN WISCONSIN TO THE
LOWER 90S OVER NORTHEAST IOWA. SHEAR PROFILES WILL REMAIN FAVORABLE
FOR A FEW STRONG TO POSSIBLY SEVERE THUNDERSTORMS WITH 0-6 KM BULK
SHEAR IN THE 25 TO 35 KT RANGE.
.LONG TERM...SUNDAY THROUGH WEDNESDAY
246 AM CDT THU JUN 28 2012
28.00 MEDIUM RANGE FORECAST MODELS CONTINUE TO SHOW UPPER RIDGING
ATTEMPTING TO BUILD INTO THE UPPER MISSISSIPPI RIVER VALLEY LATE
SUNDAY INTO MONDAY. HOWEVER...WEAK EMBEDDED SHORTWAVES LOOK TO
ROTATE THROUGH THE RIDGE AS IT TRIES TO BUILD IN. THE MODELS ARE IN
VERY GOOD AGREEMENT MONDAY NIGHT INTO TUESDAY SHOWING A STRONGER
SHORTWAVE MOVING THROUGH THE FORECAST AREA BRINGING CHANCES FOR
SHOWERS AND THUNDERSTORMS WITH IT. 850 MB TEMPERATURES CONTINUE TO
HOLD IN THE 20 TO 22 C RANGE MONDAY THROUGH WEDNESDAY. PLAN ON THE
SUMMER WARMTH PERSISTING THROUGH THE EXTENDED PERIOD WITH HIGHS IN
THE UPPER 80S TO LOWER 90S. THE PERIODIC SHOWER/THUNDERSTORM
ACTIVITY COULD PRODUCE SOME BRIEF RELIEF FROM THE THE HEAT AT
TIMES. OVERNIGHT LOWS WILL ONLY FALL INTO THE UPPER 60S TO LOWER
70S.
&&
.AVIATION...
1105 PM CDT WED JUN 27 2012
COLD FRONT WILL TRACK SOUTHEAST ACROSS THE REGION OVERNIGHT...
LIKELY MOVING THROUGH KRST NEAR 09Z AND KLSE 11Z. MOISTURE POOLING
AROUND THE BOUNDARY COULD RESULT IN SOME SUB VFR CIGS...WHICH SOME
MODELS ARE SUGGESTING. SOME 2500-3000 CLOUDS BEHIND THE BOUNDARY
EVIDENCED BY LATEST SATELLITE IMAGERY AND SFC OBS. 28.00Z NAM12 AND
LATEST RAP13 SUGGEST THAT MOISTURE WILL STAY POOLED IN THIS
REGION...AND THAT THERE WOULD BE A PERIOD OF BKN025-035. WILL ADD
A PERIOD OF BKN035 FOR NOW. IN ADDITION...LATEST HRRR CONTINUES TO
POINT TO SOME CONVECTIVE POTENTIAL OVERNIGHT AS THE LOW LEVEL
JET/MOISTURE TRANSPORT INTERACT WITH THE SFC BOUNDARY. NOT SOLD ON
THIS...BUT CAN/T RULE IT OUT EITHER. NOT ENOUGH CONFIDENCE TO ADD TO
THE TAFS HOWEVER. MVFR CIG/RAIN CHANCES WILL HAVE TO BE MONITORED
THROUGH THE OVERNIGHT HOURS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
246 AM CDT THU JUN 28 2012
WI...HEAT ADVISORY FROM NOON TODAY TO 7 PM CDT THIS EVENING FOR
WIZ054-055-061.
MN...NONE.
IA...HEAT ADVISORY FROM NOON TODAY TO 7 PM CDT THIS EVENING FOR
IAZ029-030.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM...WETENKAMP
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS LINCOLN IL
308 AM CDT SAT JUN 30 2012
.DISCUSSION...
ISSUED 305 AM CDT SAT JUN 30 2012
THUNDERSTORM ACTIVITY HAS BEEN PRESENT ACROSS THE NORTHERN CWA
THE LAST FEW HOURS...WITH SOME DEVELOPMENT ALSO OCCURRING NEAR
CHAMPAIGN AND DANVILLE AROUND 130 AM ON ONE OF THE OUTFLOWS FROM
EARLIER CONVECTION. THE SOUTHERNMOST OUTFLOW WAS GENERALLY JUST
NORTH OF A PARIS TO SHELBYVILLE LINE...WITH WINDS BEHIND IT
SHIFTING TO THE NORTHEAST. SOME INTERESTING TEMPERATURE ANTICS
AHEAD OF THIS BOUNDARY...WITH FLORA AND OLNEY BOTH SEEING TEMPS
JUMP 5-7 DEGREES BETWEEN 1 AND 2 AM...AND EFFINGHAM GOING UP 5
DEGREES SHORTLY AFTER MIDNIGHT.
SHORT TERM...TODAY THROUGH MONDAY...
MAIN CONCERN DURING THIS PERIOD WILL BE WITH CONVECTIVE CHANCES
AND TEMPERATURES...AS THE FORMER WILL DIRECTLY IMPACT THE LATTER.
SHORTWAVE CURRENTLY EXTENDING FROM THE WESTERN GREAT LAKES INTO
IOWA WILL SWING THROUGH THE REGION TODAY. SURFACE BOUNDARY/FRONT
IS PROGGED BY THE MODELS TO SLIP SOUTHWARD INTO THE CWA THIS
EVENING. EXTENT OF CONVECTIVE REDEVELOPMENT WILL HINGE ON HOW FAST
THE CURRENT STORMS DIMINISH...ALLOWING THE ATMOSPHERE TO RECHARGE.
WILL SEE DEW POINTS POOLING JUST SOUTH OF THE BOUNDARY...SO CAPES
ACROSS THE NORTHERN CWA WILL LIKELY EXCEED 3000 J/KG BY MID-
AFTERNOON. WILL KEEP MOST OF THE RAIN CHANCES NORTH OF A
BEARDSTOWN TO DANVILLE LINE TODAY...WITH SOME SLIGHT CHANCES ALONG
THE I-72 CORRIDOR.
EVENING MODELS SHOWING A SERIES OF MCS POTENTIAL TONIGHT AND
SUNDAY...WITH THE NORTH HALF OF THE CWA THE PRIMARY RECIPIENTS.
TIMING TONIGHT IS NOT AS CONSISTENT AMONG THE MODELS...SO WILL
NOT TRY TO BREAK IT DOWN WITH EVENING VS OVERNIGHT WORDING. SUNDAY
AFTERNOON IS IN BETTER AGREEMENT AS CAPES AGAIN REACH 3000-4000
J/KG BY MID-AFTERNOON. SPC CONVECTIVE OUTLOOKS FOR TODAY AND
SUNDAY BOTH HAVE SLIGHT RISKS FOR THE NORTHERN HALF OF THE CWA. BY
MONDAY... UPPER RIDGING ACROSS THE PLAINS WILL BE BUILDING TOWARD
THE MISSISSIPPI VALLEY...SHUNTING THE MCS ACTIVITY MORE TO OUR
EAST.
TEMPERATURE-WISE...THINK THE VARIOUS BOUNDARIES AND CLOUDS WILL
KEEP THE NORTHERN CWA SLIGHTLY COOLER THE NEXT FEW DAYS...WITH
MID 90S FOR HIGHS...AS OPPOSED TO THE 100+ ACROSS THE CENTRAL AND
SOUTH. AS A RESULT...WILL DOWNGRADE THE EXCESSIVE HEAT WARNING
NORTH OF A GALESBURG TO BLOOMINGTON LINE...REPLACING IT WITH A
HEAT ADVISORY. WILL KEEP THE WARNING GOING FURTHER SOUTH. HAVE
GONE WITH TEMPS 105 OR HIGHER ACROSS THE SOUTHEAST TODAY...WHERE
MORE MIXING WILL TAKE PLACE...AND 100-105 FOR SUNDAY AND MONDAY.
THE HEAT HEADLINES MAY NEED TO BE EXTENDED IN TIME...BUT QUESTIONS
REGARDING THE OUTFLOWS AND CONVECTION PRECLUDE THIS AT THE MOMENT.
LONG TERM...TUESDAY THROUGH FRIDAY...
UPPER RIDGE CONTINUES TO DOMINATE THE EASTERN HALF OF THE
NATION. 850 MB TEMPERATURES REMAIN IN THE 23-24C RANGE OVER OUR
AREA...WITH MID TO UPPER 90S FOR HIGHS. WILL KEEP DRY WEATHER
THROUGH THE PERIOD.
GEELHART
&&
.AVIATION...
ISSUED 1144 PM CDT FRI JUN 29 2012...FOR THE 06Z TAFS
MULTIPLE OUTFLOW BOUNDARIES AND THE PRESENCE OF A STATIONARY FRONT
ACROSS THE AREA WILL MAKE SCATTERED STORMS POSSIBLE ACROSS THE
NORTHERN TERMINALS OVERNIGHT. THE STRENGTHENING INVERSION MAY WORK
TO KEEP SEVERE LEVEL WINDS FROM REACHING THE SURFACE...BUT VERY
HEAVY RAINS AND SMALL HAIL WILL BE POSSIBLE AROUND PIA AND BMI
BETWEEN 06Z-10Z AS THIS NEXT LINE OF STORMS MOVES ACROSS CENTRAL
IL. THE LATEST HRRR OUTPUT SHOWS THE LINE OF STORMS WEAKENING WITH
TIME...BECOMING MAINLY SHOWERS BY THE TIME IT REACHES CMI AROUND
11Z.
SOME MVFR FOG IS INDICATED IN THE BUFKIT SOUNDINGS FOR PIA/CMI
LATER TONIGHT. THE LATEST OUTFLOW BOUNDARY HAS PUSHED SOUTH OF
BMI AND IS APPROACHING CMI/SPI/DEC. THAT DROP IN AIR TEMP WITHOUT
AN APPRECIABLE CHANGE IN DEW POINT MAY ALLOW FOR LIGHT FOG EVEN FOR
THE SOUTHERN TERMINALS. FOR NOW WE PLAN ON KEEPING FOG OUT IN THE
SOUTH...BUT VIS WILL NEED TO BE MONITORED.
CLOUD COVER WILL BE MAINLY MID AND HIGH CLOUDS EVEN IN
THUNDERSTORMS. UPSTREAM OBS DID NOT SHOW ANY MVFR CIGS AS THE
THUNDERSTORMS MOVED OVER. IFR VIS WILL BE MORE LIKELY IN HEAVIER
RAINS. AT PIA...WE INTRODUCED SOME 2SM TSRA FOR A FEW HOURS
THROUGH 09Z. THEN WE KEPT A TEMPO FOR MVFR FOG THROUGH 13Z AT PIA
AND PREVAILING MVFR FOG AT CMI THROUGH 14Z.
SHIMON
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
EXCESSIVE HEAT WARNING UNTIL 7 PM CDT SUNDAY FOR ILZ036-040>057-
061>063-066>068-071>073.
HEAT ADVISORY FROM NOON TODAY TO 7 PM CDT SUNDAY FOR ILZ027>031-
037-038.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1144 PM CDT FRI JUN 29 2012
.DISCUSSION...
ISSUED 855 PM CDT FRI JUN 29 2012
STORMS JUST TO THE W AND N OF OUR NORTHERN COUNTIES HAVE DIMINISHED
IN INTENSITY OVER THE LAST HOUR. THE SOUTHERN FLANK OF A LINE OF
STORMS IS POISED TO MOVE EAST ACROSS KNOX/STARK/MARSHALL
COUNTIES...AND POSSIBLY FAR NORTHERN PEORIA/NORTHERN WOODFORD
COUNTIES AS WELL. WE CURRENTLY HAVE CHANCE POPS IN PLACE ACROSS
THOSE AREAS. HOWEVER...WE EXPECT TO BUMP UP TO LIKELY POPS FOR N
KNOX/STARK/MARSHALL AND LEAVE CHANCE TO THE SOUTH.
00Z ILX SOUNDING SHOWS 3200 J/KG MLCAPE AVAIL ABOVE THE WARM
CAPPING INVERSION...HOWEVER WITH SUBSTANTIAL DRY AIR ALOFT AS
WELL. THE INVERSION WILL LIKELY BEGIN TO INCREASE WITH DIURNAL
SURFACE COOLING. THE OUTFLOW BOUNDARY THAT MOVED SOUTH TO NEAR
SPI/ILX LATE THIS AFTERNOON HAS REBOUNDED QUICKLY TO THE NORTH
WITH THE RE-ESTABLISHMENT OF THE SW FLOW. THAT BOUNDARY...ALONG
WITH THE COLD POOL BOUNDARY FROM THE STORMS TO OUR NORTH THIS
EVENING...MAY HELP BE A FOCUS FOR ADDITIONAL STORM DEVELOPMENT
LATER TONIGHT. SPC HAS INDICATED THEY WILL BE MONITORING OUR
NORTHERN COUNTIES FOR THE POSSIBLE NEED FOR A WATCH LATER
TONIGHT...BUT ACKNOWLEDGE THE CONVECTIVE INHIBITION MAY BE TOO
STRONG TO OVERCOME.
WILL ADJUST POPS AS MENTIONED EARLIER...WITH SMALL ADJUSTMENT
DOWNWARD TO THE OVERNIGHT LOWS BEHIND THE COLD POOL IN THE NORTH.
WINDS WILL BE VARIABLE WITH THE BOUNDARIES ACROSS THE NORTHERN
HALF...WITH SOUTHWEST FLOW IN THE SOUTH. WILL MAKE MINOR
ADJUSTMENTS TO THE WINDS AS WELL.
UPDATED INFO WILL BE AVAILABLE SHORTLY.
SHIMON
&&
.AVIATION...
ISSUED 1144 PM CDT FRI JUN 29 2012...FOR THE 06Z TAFS
MULTIPLE OUTFLOW BOUNDARIES AND THE PRESENCE OF A STATIONARY FRONT
ACROSS THE AREA WILL MAKE SCATTERED STORMS POSSIBLE ACROSS THE
NORTHERN TERMINALS OVERNIGHT. THE STRENGTHENING INVERSION MAY WORK
TO KEEP SEVERE LEVEL WINDS FROM REACHING THE SURFACE...BUT VERY
HEAVY RAINS AND SMALL HAIL WILL BE POSSIBLE AROUND PIA AND BMI
BETWEEN 06Z-10Z AS THIS NEXT LINE OF STORMS MOVES ACROSS CENTRAL
IL. THE LATEST HRRR OUTPUT SHOWS THE LINE OF STORMS WEAKENING WITH
TIME...BECOMING MAINLY SHOWERS BY THE TIME IT REACHES CMI AROUND
11Z.
SOME MVFR FOG IS INDICATED IN THE BUFKIT SOUNDINGS FOR PIA/CMI
LATER TONIGHT. THE LATEST OUTFLOW BOUNDARY HAS PUSHED SOUTH OF
BMI AND IS APPROACHING CMI/SPI/DEC. THAT DROP IN AIR TEMP WITHOUT
AN APPRECIABLE CHANGE IN DEWPOINT MAY ALLOW FOR LIGHT FOG EVEN FOR
THE SOUTHERN TERMINALS. FOR NOW WE PLAN ON KEEPING FOG OUT IN THE
SOUTH...BUT VIS WILL NEED TO BE MONITORED.
CLOUD COVER WILL BE MAINLY MID AND HIGH CLOUDS EVEN IN
THUNDERSTORMS. UPSTREAM OBS DID NOT SHOW ANY MVFR CIGS AS THE
THUNDERSTORMS MOVED OVER. IFR VIS WILL BE MORE LIKELY IN HEAVIER
RAINS. AT PIA...WE INTRODUCED SOME 2SM TSRA FOR A FEW HOURS
THROUGH 09Z. THEN WE KEPT A TEMPO FOR MVFR FOG THROUGH 13Z AT PIA
AND PREVAILING MVFR FOG AT CMI THROUGH 14Z.
SHIMON
&&
.PREV DISCUSSION...
ISSUED 307 PM CDT FRI JUN 29 2012
MAIN CONCERNS CONTINUE TO BE CHANCE OF PCPN AND LOCATION AS MOST
OF THE CWA SITS UNDER A HEAT DOME. OVERALL...MODELS IN GOOD
AGREEMENT WITH LARGE SCALE FEATURES BUT HAVE TROUBLE WITH THE
SMALLER SCALE FEATURES THAT WOULD AFFECT PCPN TIMING AND LOCATION
AS WELL AS HIGH TEMPS THROUGH DURING THE AFTERNOON. SHORT
TERM...HRRR MODEL...LOOKS TO BE DOING QUITE WELL WITH LOCATION OF
SOME OF THESE SMALLER FEATURES AND RESULTING PCPN. SO THROUGH
TONIGHT WE WILL FOLLOW THE HRRR AND THEN SWITCH TO NAM-WRF/ECMWF.
GFS REMAINS TOO WET.
SHORT TERM...TONIGHT THROUGH MONDAY
CONVECTION OUT OVER IOWA WILL BEGIN TO INCREASE LATE THIS
AFTERNOON AND SLOWLY SLIDE EAST INTO NRN IL. SO CHC POPS IN THE
NORTHERN THIRD OF THE CWA LOOKS GOOD FOR THIS EVENING AND INTO
OVERNIGHT. THIS SHOULD HELP TO KEEP THE FRONT ACROSS THE NORTHERN
PART OF THE CWA INTO TOMORROW. SO WILL KEEP CHC POPS IN THE NORTH
FOR TOMORROW. BEST SCIENTIFIC GUESS RIGHT NOW IS FOR THE FRONT TO
REMAIN IN THAT GENERAL AREA THROUGH TOMORROW AND THEN SLOWLY PUSH
NORTH TOMORROW NIGHT AND REMAIN UP THERE THROUGH SUNDAY. SO WILL
KEEP CHC POPS NEAR THE FRONT AND HAVE SLIGHT CHC POPS TO THE SOUTH
OF THE FRONT...REMAINING IN THE EXTREME NORTH PARTS OF THE
CWA...THROUGH MONDAY.
WARM TEMPS WILL CONTINUE THROUGH THE PERIOD WITH WARMEST TEMPS IN
THE SOUTH HALF OF THE CWA. 90S ARE STILL EXPECTED IN THE NORTH BUT
CLOUDS AND PCPN WILL KEEP THEM DOWN A TAD. HIGHEST DEWPOINTS WILL
BE NORTH WITH THE FRONT WITH DRIER AIR DOWN WITH THE WARMEST
TEMPS. THIS COMBINATION OF DEWPOINTS AND TEMPS WILL CONTINUE THE
HEAT INDEX VALUES AROUND 105 THROUGH SUNDAY...ESPECIALLY IN THE
SOUTHERN HALF OF THE CWA. THE NORTHERN AREAS COULD STILL REACH TO
100 FOR HEAT INDEX...BUT WITH THE HIGHER HUMIDITY OPPRESSIVE
CONDITIONS WILL CONTINUE THERE AS WELL. SO SINCE THIS WILL GO
THROUGH SUNDAY AND REACH 4 DAYS...HAVE CANCELLED REPLACED THE
ADVISORY WITH AN EXCESSIVE HEAT WARNING. IF CRITERIA IS NOT BEING
REACHED IN THE NORTH...THEN LATER SHIFTS CANCEL AS THE NEED
ARISES. HEAT INDICES AT NIGHT SHOULD REMAIN ABOVE 75 AS WELL.
COMPROMISED OF GUIDANCE LOOKS BEST AND RAISED TEMPS A LITTLE IN THE
NORTH.
LONG TERM...MONDAY NIGHT THROUGH FRIDAY
RIDGING OVER THE MIDDLE PART OF THE US WILL REMAIN IN PLACE
THROUGH THE WEEK WITH WEAK IMPULSES RIDING ALONG THE NORTHERN EDGE
OF THE RIDGE. PCPN IS POSSIBLE BUT TIMING AND LOCATION IS VERY
DIFFICULT TO PREDICT THIS FAR OUT. SO HAVE OPTED WITH DRY FORECAST
THROUGH FRIDAY UNTIL BETTER SIGNALS SHOW WHEN PCPN WILL BE. TEMPS
SHOULD REMAIN WARM IN THE MIDDLE TO UPPER 90S...WHICH IS WARMER
THAN GUIDANCE.
AUTEN
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
EXCESSIVE HEAT WARNING UNTIL 7 PM CDT SUNDAY FOR ILZ027>031-
036>038-040>057-061>063-066>068-071>073.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1233 AM CDT SAT JUN 30 2012
.AVIATION...
AN AREA OF THUNDERSTORMS CONTINUES TO AFFECT PORTIONS OF THE
SOUTHERN HALF OF THE REGION...MAINLY AFFECTING KBRL AND SHOULD BE
OUT OF THE KMLI VCNTY BY 07Z. THIS AREA OF THUNDERSTORMS IS
EXPECTED TO PERSIST FOR AT LEAST A FEW MORE HOURS AS NEW CELLS ARE
GENERATED ON THE WEST SIDE AND MOVE EAST...THOUGH THEY SHOULD
CONTINUE TO DIMINISH IN STRENGTH THROUGH 09Z. THERE WILL BE
ADDITIONAL THUNDERSTORMS MOVING INTO THE AREA AFTER 09Z AS THE
CLUSTER CURRENTLY OVER NORTHWEST IOWA IS EXPANDING AGAIN AS IT
MOVES INTO THE BROAD SOUTHWEST WARM MOIST FEED OVER MOST OF IOWA.
THIS WILL KEEP THUNDERSTORMS IN THE GENERAL AREA FOR MOST OF THE
NIGHT AND EARLY SATURDAY MORNING...BUT WITH TIMING AND PLACEMENT
UNCERTAINTIES HAVE LEFT THEM OUT OF THE TERMINALS FOR NOW.
SATURDAY THE MID LEVEL WARM FRONT AND WARM AIR ADVECTION ZONE WILL
BE OVER SOUTHERN IOWA FOR MOST OF THE AFTERNOON AND EVENING.
STORMS ARE EXPECTED TO REDEVELOP DURING THIS TIME RANGE WITH THE
FAVORABLE HEATING. BUT...SINCE DETAILS OF TIMING AND LOCATION REMAIN
UNCERTAIN...HAVE DECIDED TO KEEP THUNDER OUT OF THE TAFS FOR
LATER PERIODS UNTIL THE DETAILS CLARIFY. LE
&&
.PREV DISCUSSION... /ISSUED 309 PM CDT FRI JUN 29 2012/
SYNOPSIS...
12Z UA ANALYSIS HAD AN IMPLIED 850MB WARM FRONT RUNNING FROM
NORTHERN NEBRASKA INTO NORTHEAST MISSOURI. MOISTURE WAS POOLING
NORTH OF THIS BOUNDARY ACROSS IOWA AND ILLINOIS WITH DEW POINTS IN
THE MID TEENS TO LOWER 20S. SATELLITE IMAGERY THROUGH EARLY
AFTERNOON HAS THE MORNING CONVECTION WELL EAST OF THE AREA WITH
NEW CONVECTION DEVELOPING AS A RESULT OF AN MCV IN WESTERN IOWA.
TRENDS IN SATELLITE/RADAR THE PAST FEW HOURS SHOWS CONVECTION
SLOWLY GETTING STRONGER.
18Z SFC ANALYSIS IS EXTREMELY NOISY WITH NUMEROUS MESOSCALE
FEATURES. A WAKE LOW WAS NEAR KRFD WITH A MESO LOW OVER THE
NORTHWEST PARTS OF THE KDSM METRO AREA. OUTFLOW BOUNDARIES WERE
ACROSS THE SOUTHERN CWFA WITH ANOTHER WEAK BOUNDARY MOVING SOUTH
FROM THE KDSM LOW TO NEAR KTVK. DEW POINTS WERE GENERALLY IN THE
60S WITH POCKETS OF 70 DEW POINTS IN WESTERN IOWA AND ALONG THE
OUTFLOW BOUNDARY IN THE SOUTHERN CWFA.
SHORT TERM...TONIGHT AND SATURDAY
NONLINEAR PROCESSES ARE DOMINATING THE SENSIBLE WX. AS SUCH
ANALYSIS OF TRENDS AND CONCEPTUAL MODELS WERE USED HEAVILY FOR THE
IMMEDIATE TERM. INPUT FROM RAP MODEL TRENDS USING THE MCS AND
LIFT TOOLS HELPED A LITTLE TOO.
TRENDS FROM THE RAP MODEL SUGGEST CONVECTION WILL CONTINUE TO
DEVELOP AND STRENGTHEN ACROSS SOUTHERN IOWA THE NEXT SEVERAL
HOURS. MCS TOOL SUGGESTS THE COLLISION OF THE OUTFLOW BOUNDARY WITH
THE APPROACHING BOUNDARY FROM THE MESO LOW WILL INITIATE
CONVECTION THAT MOVES INTO THE CWFA LATE THIS AFTERNOON. SAID
CONVECTION SHOULD EVOLVE INTO A LINEAR MCS THAT MOVES EAST AND
SOUTH DURING THE EVENING HOURS.
THE POTENTIAL ENERGY BUILT UP IN THE CLEAR AREAS ACROSS SOUTHERN
IOWA SHOULD ALLOW THE STORMS TO BECOME QUITE STRONG. SEVERE STORMS
MAY BE POSSIBLE LATE THIS AFTERNOON AND EVENING WITH THE NEW
CONVECTION. TRENDS OVER THE NEXT FEW HOURS WILL BE THE KEY TO WHAT
HAPPENS.
LATER TONIGHT...THE MCS AND LIFT TOOLS ARE SUGGESTING YET ANOTHER
MCS WILL DEVELOP OUT WEST AND MOVE INTO THE AREA. EFFECTIVE
BOUNDARIES LEFT OVER FROM THE EARLIER CONVECTION SHOULD DICTATE
WHERE THIS CONVECTION GOES. REGARDLESS...THIS CONVECTION SHOULD
BE ANOTHER LINEAR MCS. IF THIS MCS CAN BECOME SURFACE BASED...THE
DIFFERENTIAL THETA E SUGGESTED IN THE MODELS WOULD SUPPORT SEVERE
STORMS WITH WIND...POSSIBLY EXTREME...BEING THE PRIMARY THREAT.
THIS SECOND MCS SHOULD BE IN A DECAYING MODE OR EXITING THE CWFA
SATURDAY MORNING. COLD POOLS LEFT OVER FROM THIS MCS ALONG WITH
OUTFLOW BOUNDARIES WOULD THEN PROVIDE THE FOCUS FOR NEW CONVECTION
SATURDAY AFTERNOON.
AS FOR THE HEAT HEADLINES...THE OUTFLOW BOUNDARY FROM CONVECTION
THIS MORNING HAS HELPED HOLD DOWN TEMPERATURES SOMEWHAT ACROSS THE
SOUTH. FOR NOW WILL CONTINUE WITH THE CURRENT HEADLINES BUT
CONVECTION LATE THIS AFTERNOON/EVENING MAY RESULT IN THE HEAT
ADVISORY BEING CANCELLED FOR MOST IF NOT ALL OF THE AREA. ..08..
LONG TERM...SATURDAY NIGHT THROUGH NEXT FRIDAY...
ABOVE NORMAL TEMPERATURES TO CONTINUE AND HUMID WITH A CHANCE OF
THUNDERSTORMS INTO MONDAY.
OVERVIEW...CONCERNS OF NON-LINEAR CONVECTION AND OUTFLOW BOUNDARIES
AS HAVE OCCURRED TODAY AND DISCUSSED YESTERDAY TO REMAIN A MAJOR
CHALLENGE INTO MONDAY.
INITIALIZATION ADEQUATE WITH VERIFICATION SUGGESTING AN OVERWEIGHT OF
GFS AND NAM-WRF. CONVECTION THIS PM AND TONIGHT WILL IMPACT NEXT
ROUND OF CONVECTION TOMORROW NIGHT INTO SUNDAY AS WELL AS
TEMPERATURES...JUST LIKE TODAY. AGAIN...TIMING AND LOCATION OF
PRECIPITATION WILL BE HARD TO CLARIFY BEYOND 6-12 HOURS AHEAD DUE TO
NON-LINEAR NATURE AND OUTFLOW BOUNDARIES IMPACTING SUBSEQUENT
CONVECTION EVENTS. HIGH TO EXTREME STABILITY IS STILL INDICATED INTO
MONDAY WITH MUCAPES OF 2500 TO 4000+ J/KG...MAX DIFFERENTIAL THETA_E
OF 30C...POSSIBLY MORE AND WBZ 12-14K AGL SUPPORTIVE OF RISK OF
DAMAGING TO VERY DAMAGING STRAIGHT LINE WINDS. THE NEXT COUPLE OF
DAYS MAY SEE REPORTS OF 80+ MPH WINDS NEAR OR IN OUR FORECAST AREA
DUE TO THIS HIGH TO EXTREME INSTABILITY. THIS HAS NOW OCCURRED TODAY
WITH OUR CONVECTION THIS MORNING NOW MOVING EAST INTO NORTHERN
INDIANA AS A BOWING SYSTEM AND IS BECOMING A DERECHO WITH FORT WAYNE
AIRPORT REPORTING MEASURED WIND GUSTS OF 79 KTS...OR 91 MPH.
TEMPERATURES TO STAY ABOVE NORMAL BY 5 TO 10 DEGREES THROUGH NEXT
WEEK.
SATURDAY NIGHT THROUGH SUNDAY...UPPED POPS WITH ANOTHER ROUND OF
CONVECTION SUGGESTED...MAINLY FOR SOUTH 1/2 OF AREA. KEY WILL BE
STRENGTH OF OUTFLOW FROM MCS TONIGHT INTO SATURDAY. NORTH SECTIONS
SHOULD STAY NORTH OF OF COOL POOL OUTFLOW AND SUPPORTIVE OF HIGHS 90
DEGREES AND POSSIBLY ONLY MID 80S FOR LATER SHIFTS ON SUNDAY.
MINS SATURDAY NIGHT MOSTLY 70 TO 75 DEGREES WITH UPPER 60S POSSIBLE
IN HEAVIEST RAINFALL AREAS. HIGH PW/S OF OVER 1.5 UP TO 2 INCHES AND
WEAKER STEERING CONTINUE TO SUPPORT LOCALLY HEAVY RAINFALL OF 2 PLUS
INCHES FOR LATER SHIFTS TO MONITOR AND POSSIBLY 3+ INCHES WITH
TRAINING OF STORMS AND POSSIBLE T-BONE OF WARM ADVECTION WING OF
STORMS AHEAD OF A MAIN BOWING LINE. IF WE GET GOOD LATE PM HEATING
THEN CONCERN REMAINS OF A DECENT AREA OF STRONG WINDS WITH A BOWING
SEGMENT AS MENTIONED ABOVE EARLIER DUE TO HIGH/EXTREME INSTABILITY.
HEAT INDICES IN SOUTHERN SECTIONS MAY PUSH UPPER 90S TO AROUND 100
DEGREES SUNDAY AFTERNOON.
SUNDAY NIGHT AND MONDAY...HAVE LOW CHANCE POPS ATTM...POOR CONFIDENCE
HERE DUE TO EVIDENCE OF WARM FRONT TO PUSH NORTH AND ENOUGH UPPER
SUPPORT FOR ANOTHER MCS THAT SOLUTIONS OFTEN POORLY CAPTURE. LATER
SHIFTS MAY NEED TO AGAIN UP POPS AND ADJUST HI TEMPERATURES DOWN AS
THE CASE THE PREVIOUS 3 DAYS.
MONDAY NIGHT THROUGH FRIDAY...AREA TO REMAIN ON THE EDGE OF OUR
NORMAL MID SUMMER "RING OF FIRE" WITH STRONG UPPER LEVEL RIDING. KEPT
MOSTLY DRY BUT A LOW RISK OF CONVECTION REMAINS THAT MAY PROPAGATE
OR FIRE FOR LATER SHIFTS TO RECONSIDER. MODERATE TO HIGH INSTABILITY
CONTINUE TO SUPPORT A SEVERE STORM POTENTIAL WITH ANY STORMS WITH
AGAIN STRONG STRAIGHT LINE WINDS DUE TO HIGH INSTABILITY. HI
TEMPERATURES MOSTLY 90 TO 95 DEGREES WITH SOME UPPER 90S POSSIBLE IN
SOUTH AND LOWS MOSTLY 70 TO 75 DEGREES AND AFTERNOON HEAT INDICES 95
TO 100 DEGREES SUGGESTED FOR A FEW TO SEVERAL HOURS. EVIDENCE OF A
BREAK IN THE HEAT TO DEVELOP BY THE FOLLOWING WEEKEND.
NICHOLS
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS JACKSON KY
123 AM EDT SAT JUN 30 2012
.UPDATE...
ISSUED AT 1035 PM EDT FRI JUN 29 2012
WOW! AFTER SETTING ALL TIME RECORD HIGHS THROUGH THE AREA
TODAY...THOUGH FOR MOST OF THE RECORDS FOR OUR MAIN SITES ONLY DATE
BACK TO THE MID AND LATE 20TH CENTURY...EAST KENTUCKY HAD TO DEAL
WITH A STRONG GUST FRONT BLASTING SOUTH FROM A VERY MEAN DERECHO THAT
ROLLED BY TO THE NORTH. THIS BOUNDARY BROUGHT DAMAGING WIND GUSTS TO
OUR NORTHEAST TIER BEFORE IT WEAKENED AND DISSIPATED OVER THE
SOUTHERN HALF OF THE CWA. UNFORTUNATELY MANY PLACES GOT THE WIND FROM
THE STORMS BUT VERY LITTLE OF THE RAIN THAT COULD HAVE ACCOMPANIED
THEM. THIS EVENT DID BRING SOME SOMEWHAT COOLER AIR TO THE NORTHERN
HALF OF EAST KENTUCKY...THOUGH. ANYWAYS...HAVE ADDED SOME PATCHY
FOG TO THE GRIDS IN PLACES TO THE NORTHEAST THAT MAY HAVE HAVE SEEN
SOME RAIN. ELSEWHERE...ANOTHER MUGGY NIGHT WILL BE ON TAP UNDER
CLEARING SKIES. THIS WILL ALLOW A MINOR TO MODERATE RIDGE TO VALLEY
SPLIT TO DEVELOP...THOUGH ALL LOWS WILL LIKELY END UP IN THE UPPER
60S AND LOWER 70S BY DAWN. HAVE UPDATED THE GRIDS FOR A FLATTER
DIURNAL CURVE THROUGH 2 AM BEFORE THE NORMAL PATTERN TAKES OVER
AGAIN. THE REST OF THE GRIDS REMAINED VIRTUALLY UNTOUCHED FROM THE
LAST UPDATE AND THE ZONES WILL BE LEFT TO STAND AS THEY ARE. AN
UPDATED NPW FOR THE HEAT ADVISORY IS FORTHCOMING. WE WILL SEE WHAT
TOMORROW BRINGS AND WHETHER WE WILL SEE ANY RIDGE RIDERS OR THEIR
ANCILLARY EFFECTS IMPACT OUR AREA...AS THE HEAT ONCE AGAIN DOMINATES.
IN CASE ANYONE MISSED IT...JKL SET AN ALL TIME RECORD HIGH OF 104
TODAY AND LOZ DID THE SAME BY TOPPING OUT AT 105 DEGREES.
UPDATE ISSUED AT 850 PM EDT FRI JUN 29 2012
HAVE UPDATED THE GRIDS TO REMOVE SEVERE WORDING AND BACK OFF POPS AND
SKY COVER IN THE WAKE OF THE EXITING AND DISSIPATING GUST FRONT. HAVE
ALSO ADJUSTED THE TEMPERATURES TO ACCOUNT FOR THE COOL POOL IN THE
WAKE OF THE FRONT...ALONG WITH A TWEAK TO THE DIURNAL CURVE THAT THIS
AFFECTS. NEW ZONES AND HWO WILL BE FORTHCOMING.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 315 PM EDT FRI JUN 29 2012
THE HEAT WAVE WILL CONTINUE THROUGH THE WEEKEND WITH HIGH PRESSURE
STAYING IN PLACE. THE MAIN FORECAST ISSUES ARE TO TRY AND FORECAST
THE SHORT WAVES MOVING AROUND THE PERIPHERY OF THE UPPER HIGH AND
TRY AND DETERMINE IF THEY WILL BE STRONG ENOUGH TO INITIATE
CONVECTION. THE HRRR WAS SHOWING A MCS TYPE OF SYSTEM BARELY
EFFECTING THE AREA NORTH OF THE MOUNTAIN PARKWAY. CONSIDERING THE
SEVERE THUNDERSTORM WATCH IS JUST NORTH OF THE FORECAST
AREA...THOUGHT IT WOULD BE WISE TO INCLUDE SOME THUNDER IN THE
FORECAST. IT IS THE SAME SITUATION FOR TOMORROW...WITH ANOTHER WAVE
MOVING ACROSS THE AREA. THE HEAT IS PRETTY MUCH A SLAM DUNK. WE BROKE THE
THE ALL TIME RECORD FOR JACKSON AT 102 TODAY AND IT MIGHT EVEN GO UP
IN THE NEXT HOUR. WILL HAVE TO WAIT AND SEE. LONDON ALSO HIT 102
TIED THE ALL TIME RECORD FOR THE YEAR.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 315 PM EDT FRI JUN 29 2012
THE EXTENDED FORECAST PERIOD CONTINUES TO FEATURE AND BROAD AND
STRENGTHENING RIDGE OVER MUCH OF THE CONUS STRETCHING FROM THE FRONT
RANGE OF THE ROCKIES AND EAST OVER THE NORTHERN TIER OF THE TN
VALLEY AS WELL AS THE SOUTHEAST. THE MILLION DOLLAR QUESTION...OR
THE FORECAST CHALLENGE OF THE EXTENDED IS...WITH A PROMINENT TROUGH
OVER THE NEW ENGLAND AREA AND A SERIES OF RIDGE RUNNERS DIVING
SOUTHEAST THROUGH THE WESTERN FRINGE OF THE GREAT LAKES AND INTO THE
OHIO VALLEY...WILL AN MCS BE ABLE TO OVERCOME OUR DROUGHT AND MAKE
IT A BIT FURTHER SOUTH INTO THE EASTERN KENTUCKY AREA. AT THIS
POINT...THE MODELS HANDLE THE OVERALL LONG WAVE PATTERN QUITE WELL
BUT JUDGING PREVIOUS RUNS COMPARED HOW THE PATTERN HAS PANNED OUT IN
THE SYNOPTIC AND MESOSCALE...AREAS THAT WOULD HAVE RECEIVED RAIN
ACCORDING TO THE PAST RUNS HAVE NOT COME TO PASS. THIS PROVIDES A
LOWER CONFIDENCE THAT RAINFALL WILL OCCUR IN THE EXTENDED AND GIVEN
THE FACT THAT A STRONG TO DECENT CAP WILL BE IN PLACE OVER MUCH OF
THE AREA. DESPITE BOTH THE EURO AND GFS SHOWING CONVECTION UNDER THE
CAP...WILL LEAN TOWARDS A DRIER FORECAST. WILL RUN THE ALL MODEL
BLEND AND COORDINATE WITH NEIGHBORING OFFICES TO GO ON THE DRY SIDE
OF THE RESULT.
AFTER THE PRODUCING THE MODEL ALL BLEND AND COORDINATION WITH
NEIGHBORING FORECAST OFFICES...DECIDED TO GO WITH A DRY EXTENDED
FORECAST. THE LACK OF CONFIDENCE IN MODELS PRODUCING QPF IN THE
EXTENDED UNDER THE CAP AND THE WORSENING DROUGHT CONDITIONS AIDED IN
THIS DECISION. BETTER INTERROGATION WILL BE NEEDED IN LATER RUNS IF
EASTERN KENTUCKY IS TO GET MEASURABLE RAIN BUT SOME BETTER SUPPORT
ARRIVES THROUGH THE OHIO VALLEY ON THU INTO THU NIGHT THAT MAY PUT
DOWN SOME MUCH NEEDED RAIN BUT AT THIS POINT...FELT A DRY FORECAST
WOULD BE A BETTER REPRESENTATION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 123 AM EDT SAT JUN 30 2012
SOME LINGERING BKN MID LEVEL CLOUDS WILL PERSIST THROUGH THE OVERNIGHT
BUT CONDITIONS ARE GENERALLY EXPECTED TO REMAIN VFR THROUGHOUT THE
PERIOD. ANOTHER SHORT WAVE LOOKS TO SKIRT THE OHIO VALLEY DURING THE
AFTERNOON AND WITH AN UNSTABLE ATMOSPHERE DEVELOPING ACROSS THE AREA
CANNOT RULE OUT SOME TSTMS DURING THE AFTERNOON. HOWEVER...CONFIDENCE
IN ANY SPECIFIC TERMINALS SEEING IMPACTS IS TOO LOW TO INCLUDE ANY VC
GROUPS ATTM. OTHERWISE...WLY WINDS WILL GENERALLY BE LIGHT THROUGH
THE MORNING...PICKING UP AGAIN AFTER 16Z BUT SHOULD REMAIN LESS THAN
10 KTS THROUGH THE EARLY EVENING BEFORE SUBSIDING AGAIN BY 00Z.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR KYZ044-050>052-
058>060-068-069-079-080-083>088-104-106>120.
&&
$$
UPDATE...GREIF
SHORT TERM...JJ
LONG TERM....SHALLENBERGER
AVIATION...MB
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
257 AM CDT SAT JUN 30 2012
.DISCUSSION...
MAIN SHORT TERM CONCERN IS WHETHER CONVECTION ACROSS ND WILL MAKE
IT INTO WC MN BY AROUND NOON. THE REST OF THE FORECAST IS BASED ON
SHRA/TSRA CHC/S ALONG WITH THE HEAT AND HUMIDITY INCREASING
THROUGH NEXT THU.
DURING THE PAST TWO DAYS...THE MAIN INSTABILITY AXIS HAS REMAINED
ALONG THE OLD FRONTAL BOUNDARY WHICH IS BASICALLY WASHED OUT
ACROSS S IA. HOWEVER...THERE REMAINS SEVERAL WEAK SHRTWV/S ACROSS
THE NORTHERN ROCKIES/NORTHERN PLAINS WHICH WILL PLAY HAVOC ON
RAINFALL CHC/S OVER THE NEXT 24-36 HRS.
UNTIL THE MEAN UPPER RIDGE BUILDS NORTHWARD ACROSS THE CENTRAL
PLAINS/MIDWEST OVER THE NEXT SEVERAL DAYS...CHC/S OF SHRA/TSRA
WILL REMAIN IN THE FORECAST. SEVERAL OF THE LOCAL MODEL RUNS
REFLECTIVITY FORECAST HAS THE ACTIVITY ACROSS ND MOVING INTO
WESTERN MN AROUND NOON...BEFORE DISSIPATING OR DROPPING SOUTHWARD
ACROSS SD/SW MN WHERE BETTER INSTABILITY WILL EXIST LATER TODAY.
THIS AXIS OF INSTABILITY WILL BE THE MAIN PLAYER AND IF THIS AXIS
MOVES FURTHER EASTWARD...CHC/S OF PRECIPITATION WILL INCREASE
ACROSS OUR FA. WILL CONTINUE WILL LOW CHC POPS WHERE BEST
INSTABILITY WILL REMAIN TODAY...BUT LATER SHIFTS WILL NEED TO
UPDATE...ESPECIALLY IF THE INSTABILITY AXIS MOVES FURTHER TO THE
EAST. CHECK THE LATEST SPC OUTLOOK WHICH HAS OUR WESTERN FA UNDER
THE GUN FOR SVR WX. THIS SCENARIO OF WHERE THE SHRTWV/S DEVELOP
AND HOW THE INSTABILITY AXIS MOVES WILL BE CRITICAL FOR SUN/MON
WX...AND ASSOCIATED POPS. WILL CONTINUE WITH A MORE ALL MODEL BLEND
FOR CHC POPS FOR THE NEXT 24 TO 48 HRS. THERE REMAINS THE
POSSIBILITY OF A HIGH END CHC OF PRECIPITATION ALONG THE WEAKENING
FRONTAL BOUNDARY WHICH IS PROGGED TO MOVE INTO THE FA BY LATE
MON/TUE. THIS WILL LEAD TO HIGHER DEW PTS AND HEAT INDICES...ALONG
WITH A BETTER CHC OF SHRA/TSRA. LOOKS AS THOUGH THE BEST BET IS TO
CONTINUE HIGHER POPS ACROSS CENTRAL MN WHERE BETTER UPPER LEVEL
SUPPORT EXISTS.
AS FOR TEMPS...AND THE LIKELIHOOD OF RISING INTO THE MID TO UPPER
90S REMAINS GOOD FOR WED/THU WHICH HAS THE BEST SCENARIO IN TERMS
OF 85H TEMPS. FOR TEMPS TO RISE TO NEAR THE CENTURY MARK...DEW PTS
WILL LIKELY NEED TO BE LOWERED SOME. IT IS RARE TO HAVE DEW PTS
NEAR 70 OR GREATER AND TEMPS ABV 95 DEGREES IN OUR REGION. THE
LAST TIME WHERE TEMPS ROSE ABV THE CENTURY MARK...DEW PTS DROPPED
INTO THE 50S. ALTHOUGH THE PATTERN LOOKS TO CHG BY THE END OF NEXT
WEEK...IT REMAIN VERY WARM OVER THE NEXT 5...WITH HEAT INDICES
EACH DAY RISING ABV 95 TO 100...WITH THE HIGHEST TUE/WED/THU WHERE
HEAT INDICES WILL APPROACH 105 DEGREES DURING THE AFTN. ..JLT..
&&
.AVIATION... /06Z TAF ISSUANCE/
BIG QUESTION MARK FOR THIS TAF PERIOD IS WHAT DOES UPPER WAVE
CURRENTLY OVER NE MONTANA DO FOR THUNDER POTENTIAL AT TAF SITES.
00Z NAM INITIALIZING THIS WAVE BETTER THAN PREVIOUS RUNS...WITH
IT COMING INTO MN SEVERAL HOURS EARLIER THAN PREVIOUSLY EXPECTED.
WILL BE PLENTY OF INSTABILITY IN PLACE FOR IT TO WORK WITH...THE
ONLY PROBLEM...HIGH PRESSURE AT THE SFC AND WEAK H85 FLOW MAY END
UP LIMITING THUNDER POTENTIAL WITH THE WAVE. WITH THAT SAID...WOULD
NOT BE SURPRISED IF THIS WAVE KICKS OFF SOME CONVECTION ALONG THE
NRN EDGE OF THE INSTABILITY GRADIENT OVER THE ERN DAKOTAS LATE
MORNING/EARLY AFTERNOON AND SENDS IT EAST ACROSS THE MPX AREA
SATURDAY...THE ENDS OF THE LAST COUPLE OF HRRR RUNS WOULD GIVE
SOME MERITS TO THIS IDEA. AT THIS POINT CONFIDENCE NOT REAL HIGH
WITH CONVECTIVE POTENTIAL TOMORROW...BUT DID INCLUDE A VCTS AT AXN
AS THIS IS WHERE SREF PROBS FOR PRECIP IN THE AFTERNOON ARE
HIGHEST...THOUGH COULD SEE THE NEED FOR THUNDER SPREADING EAST
DEPENDING ON HOW THINGS EVOLVE TONIGHT. OTHER ISSUE WILL BE WIND
DIRECTIONS. HIGH PRESSURE WILL BE OVERHEAD DURING THIS
PERIOD...WITH A VERY BAGGY GRADIENT AND WINDS THAT LIKELY BE ALL
OVER THE PLACE...SO HAVE A LOT OF VRB WINDS MENTIONED.
KMSP...WILL HAVE TO WATCH WAVE OVER NE MT FOR CONVECTIVE POTENTIAL
AT THE FIELD. NAM SHOWS BRUNT OF WAVE GOING NORTH OF THE FIELD
DURING THE AFTERNOON...BUT WITH INSTABILITY GRADIENT
NEARBY...COULD SEE THUNDER IN THE AFTERNOON. AT THIS POINT
CONFIDENCE IS REALLY LOW ON ANY CONVECTIVE PLACEMENT...SO LEFT IT
OUT. WINDS WILL BE VERY LIGHT...BUT TREND OUT OF THE EAST TO SOUTH
ON SATURDAY.
/OUTLOOK/
.SUNDAY...VFR. SMALL CHANCE OF TSRA.
.MONDAY...VFR. CHANCE FOR TSRA OVERNIGHT.
.TUESDAY...VFR. SMALL CHANCE OF TSRA.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
JLT/MPG
AREA FORECAST DISCUSSION
NWS GLASGOW MT
338 AM MDT SAT JUN 30 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH MONDAY...
SYNOPTIC SET UP... A LARGE THERMAL RIDGE EXTENDS FROM THE
FOUR CORNERS UP INTO CENTRAL AND NORTHERN PLAINS... WHILE AN
EQUALLY LARGE TROUGH SETS OFF THE COAST OF THE PACIFIC NORTHWEST
AND EXTENDS UP INTO BRITISH COLUMBIA AND THE GULF OF ALASKA.
NORTHEASTERN MONTANA LIES WEDGED IN BETWEEN THESE TWO LARGE
FEATURES ON THE WARMER SIDE OF SOUTHWEST FLOW. THIS FLOW PATTERN
ALLOWS FOR SMALLER RIDGES AND TROUGHS TO QUICKLY MOVE THROUGH THE
AREA.
TODAY THOUGH TONIGHT... RAPID TRANSITION FROM ZONAL FLOW TO
RIDGING IS ANTICIPATED. THIS SHOULD PUT A DAMPER ON SHOWERS ACROSS
THE AREA FOR THE NEXT 24 HOURS. HOWEVER... TEMPERATURES WILL BE ON THE
RISE ALONG WITH SOUTHEAST WINDS WHICH SHOULD SUPPORT THE WARMING.
SKIES WILL BE CLEAR TO PARTLY CLOUD WITH INCREASINGLY MUGGY
CONDITIONS AS A SURFACE BASED LEE SIDE MOUNTAIN TROUGH SETS UP OFF
THE FRONT RANGE AND BEGIN PULLING IN HIGHER DEWPOINTS AT THE
SURFACE FROM THE SOUTHEAST.
SUNDAY THROUGH SUNDAY NIGHT... A LOBE OF VORTICITY OFF THE LARGE
SYNOPTIC TROUGH WILL ZOOM ONSHORE AND MAKE A BEELINE FOR NORTHERN
MONTANA. THIS ENERGY WILL FORM A LOW OVER SOUTHERN SASKATCHEWAN AND
LATCH ONTO THE LEE SIDE MOUNTAIN TROUGH DRAGGING IT ACROSS
NORTHEAST MONTANA. THE LEE TROUGH WILL THEN BECOME A FOCAL POINT
FOR AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS. THE STORMS
SHOULD EXIT THE AREA MONDAY MORNING.
THESE STORMS WILL EASILY BECOME SEVERE.
SEVERE POTENTIAL WILL BE AIDED BY AN ATMOSPHERIC RIVER GETTING
ITS FETCH OFF OF THE PACIFIC. IT IS MOST NOTICEABLE AROUND THE
700MB LEVEL IN MIXING RATIOS AND WILL BE RAISING PRECIPITABLE
WATER FOR POINT SOUNDINGS TO BETWEEN 1 AND 1.5 INCHES. CURRENTLY... A
LINE OF THUNDERSTORMS IS ANTICIPATED FORM ON THE LEE TROUGH DURING
PEAK HEATING AROUND 2 TO 4 PM ALONG A LINE FROM OPHEIM TO GLASGOW
TO JORDAN AND DOWN TO MILES CITY AND THEN SLOWLY MOVE EAST. QPF
FIELDS IN MODELS HINT TOWARDS SOME POTENTIAL BACK BUILDING SO
FLASH FLOODING DUE TO TRAINING MAY BE POSSIBLE. CAPE VALUES ARE
RUNNING BETWEEN 1500 TO 3000 J/KG. THE HAIL GROWTH ZONE WILL BE
AROUND 25 KFT AND CAPE AT THAT LEVEL SHOULD BE MORE THAN
SUFFICIENT TO FORM QUARTERS AND POSSIBLY A FEW GOLF BALLS. AN
INVERTED V SOUNDING IS PRESENT... HOWEVER SYNOPTIC WINDS APPEAR TO
BE LACKLUSTER. THE SURFACE PROFILE FOR THESE STORMS SHOULD ALSO
MODIFY DUE TO THE HIGH PW. BECAUSE OF THIS...STRONG WINDS WILL BE
POSSIBLE WITH INDIVIDUAL CELLS BUT PROBABLY WILL NOT BE THE MAIN
SHOW. ANYWHERE BETWEEN 25 TO 35 KTS OF SHEAR OVER THE 0-6KM SEEMS
SUFFICIENT TO MAINTAIN LONG LASTING SUPERCELLS ALONG BROKEN LINE
SEGMENTS.
NAM AND GFS ARE BOTH SHOWING THIS EVENT BUT FURTHER DETAILS MAY
BE SKETCHY UNTIL 12 TO 18 HOURS IN WHEN HIRESARW AND HRRR MODELS
CAN START PINNING MOST LIKELY STORM GROWTH AREAS OR WATER VAPOR
IMAGERY BEGINS TO PICK UP ON THE STRONGEST JET STREAKS.
MONDAY... FLOW WILL TRANSITION BACK FROM SOUTHWEST TO MORE ZONAL
BY THE AFTERNOON. A SLIGHT COOL DOWN IS ANTICIPATED WITH DRY
CONDITIONS AND PARTLY CLOUDY SKIES. GAH
.LONG TERM...MONDAY NIGHT THROUGH SATURDAY...
UPPER RIDGE CONTINUES TO DOMINATE OVER THE CENTRAL PORTION OF THE
COUNTRY WITH TROF OVER THE PACIFIC NORTHWEST. SOUTHWEST FLOW WILL
PULL HOT AIR AND MODERATELY DRY AIR INTO THE REGION FOR MOST OF
THE WEEK. NO PARTICULARLY STRONG SYSTEMS EXPECTED FOR DEVELOPMENT
OF CONVECTION...BUT MAY HAVE A WAVE PUSH INTO CENTRAL CANADA
TUESDAY OR TUESDAY NIGHT AND ANOTHER WAVE OR SERIES OF WAVES LATE
IN THE WEEK. EBERT
&&
.AVIATION...
VFR WITH HIGH PRESSURE BUILDING INTO THE STATE. WINDS WILL BE FROM
THE NORTHWEST AT 10KTS OR LESS TODAY...GOING AROUND TO THE EAST
TONIGHT. RAE
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
406 AM CDT SAT JUN 30 2012
.DISCUSSION...
UPPER LEVEL RIDGING REMAINS IN PLACE ACROSS THE CENTRAL
PLAINS...WITH LONGWAVE TROUGHS OVER THE EASTERN PACIFIC AND
EASTERN CANADA. THE LOCAL AREA WAS IN AN AREA OF SUBSIDENCE BEHIND
A SYSTEM WHICH HAD MOVED INTO IOWA/ILLINOIS. WATER VAPOR IMAGERY
SHOWED THIS PATTERN...AND ALSO PICKED UP ON A SHORTWAVE TROUGH
OVER WESTERN WYOMING.
AT THE SURFACE...DEWPOINTS ACROSS THE FORECAST AREA RANGED FROM
THE 40S IN THE EASTERN PANHANDLE TO AROUND 70 AT KLBF.
OBSERVATIONS INDICATED A BOUNDARY FROM AROUND KIEN TO KOGA THROUGH
KMCK AND INTO NORTH CENTRAL KANSAS WITH EASTERLY WINDS ON THE EAST
SIDE OF THE BOUNDARY.
HOW TODAY/S WEATHER PANS OUT WILL DEPEND ON IF CONVECTION DEVELOPS
AHEAD OF THE WYOMING SHORTWAVE THIS MORNING. THE 30.00Z AND 30.06Z
NAM FIRE STORMS OVER THE PANHANDLE BETWEEN 12Z AND 15Z AND THE
RAPID REFRESH DOES SHOW SOME INDICATIONS OF CONVECTION IN THESE
AREAS...BUT THESE ARE THE ONLY MODELS TO DO SO. THE GFS/EC/GEM
ARE ALL DRY WHILE THE LATEST HRRR AND DOES DEVELOP STORMS...BUT
KEEPS THEM OVER SOUTH DAKOTA. ALTHOUGH THE NAM IS THE
OUTLIER...THERE IS ELEVATED INSTABILITY AND MOISTURE IN THE AREA
AND WITH THE WAVE MOVING ACROSS THE REGION...DON/T WANT TO
DISCOUNT ITS OUTPUT. THE ACTIVITY OVER WYOMING IS VERY HIGH BASED
/AROUND 11K FEET/. WILL ASSUME THAT TREND WILL CONTINUE WITH THE
MORNING HOURS BRINGING SOME SCATTERED RADAR RETURNS WITH NO
MEASURABLE RAIN TO THE NORTHWEST PART OF THE FORECAST AREA. THERE
COULD BE AN ISOLATED LIGHTNING STRIKES...AND COLLAPSING
SHOWERS/STORMS COULD CAUSE SOME GUSTY WINDS. FOR THE
AFTERNOON...PEAK HEATING...INSTABILITY AND A WEAK SHORTWAVE
PASSING SHOULD BE ENOUGH FOR STORMS TO DEVELOP. THESE STORMS TOO
WILL BE HIGH BASED AND WITH QUITE A BIT OF DRY AIR IN THE BOUNDARY
LAYER DON/T HAVE A LOT OF CONFIDENCE ON THE COVERAGE OF MEASURABLE
RAINFALL. WITH THESE CHANCES AND AS THE LOW LEVEL JET PICKS UP
THIS EVENING...KEPT CHANCES IN THE FORECAST AT THROUGH TONIGHT.
NOT A MAJOR THREAT FOR SEVERE STORMS AS THE WARMTH OF THE LAYER
ALOFT SHOULD PRECLUDE THE CHANCES FOR LARGE HAIL TO MAKE IT TO THE
GROUND. THERE IS 30 TO 45KTS OF DEEP LAYER SHEAR SO CAN/T DISCOUNT
AN ISOLATED ORGANIZED STORM BUT THINKING THE PRIMARY THREAT WILL
BE STRONG WINDS. DID DROP HIGH TEMPERATURES BY A FEW DEGREES TODAY
DUE MAINLY TO THE HIGHER CLOUD COVER EXPECTED. BUT IT WILL STILL
BE VERY WARM WITH HIGHS IN THE MID TO UPPER 90S MOST LOCATIONS.
THE UPPER LEVEL TROUGH OVER THE PACIFIC WILL MOVE ONSHORE
TONIGHT...WHICH WILL BEGIN TO AMPLIFY THE FLOW AGAIN WITH THE
RIDGE BUILDING NORTH ACROSS THE PLAINS THROUGH MONDAY. THE MODELS
ARE TRYING TO PUSH A SHORTWAVE TROUGH OVER THE RIDGE ACROSS
WYOMING AND SOUTH DAKOTA ON SUNDAY SO DEVELOP PRECIPITATION OVER
THE AREA. WARM AIR ALOFT MAY KEEP SOME OF THIS FROM HAPPENING SO
MAY HAVE HIGHER CHANCES OVER THE HIGHER TERRAIN BUT WILL KEEP A
SLIGHT CHANCE OVER THE NORTHEASTERN COUNTIES AS WELL. THEN MONDAY
WILL BE DRY AS NEBRASKA SITS RIGHT UNDER THE RIDGE. FOR
TEMPERATURES...FORECAST SOUNDINGS SHOWING FULL MIXING ON SUNDAY
AND MONDAY. DID TAKE INTO ACCOUNT HIGHER CLOUD COVER ESPECIALLY OVER
THE NORTHERN PARTS OF THE FORECAST AREA SUNDAY SO DIDN/T GO AS
WARM IN THE FORECAST IN THOSE AREAS. STILL EXPECTING MID TO
UPPER 90S THOUGH. MONDAY SHOULD BE A BIT WARMER WITH MUCH OF THE
AREA LOOKING TO BE INTO THE TRIPLE DIGITS AGAIN.
NO END IS IN SITE FOR THE WARMTH AS THE MODELS KEEP THE RIDGE IN
PLACE THROUGH THE REMAINDER OF NEXT WEEK. THIS LEADS TO LOW
CHANCES FOR RAIN AND HOT TEMPERATURES. HIGHS LOOK TO BE IN THE MID
TO UPPER 90S AND SOME DAYS HITTING 100 DEGREES OR BETTER. BY
FRIDAY EVENING THE RIDGE MAY SHIFT EAST FAR ENOUGH FOR STORMS
DEVELOPING OVER COLORADO AND WYOMING TO MOVE INTO THE EASTERN
PANHANDLE. BUT UNTIL THEN THE FORECAST LOOKS DRY FOR MUCH OF NEXT
WEEK.
&&
.AVIATION...
THERE IS LITTLE AGREEMENT AMONG FORECASTS REGARDING THE POSSIBILITY
OF THUNDERSTORMS IN CENTRAL AND WESTERN NEBRASKA THIS AFTERNOON OR
OVERNIGHT. WITH A FRONT OSCILLATING NORTH AND SOUTH ACROSS
NEBRASKA...THERE IS A SYSTEM TO TRIGGER AT LEAST WIDELY SCATTERED
THUNDERSTORMS OVER MUCH OF THE AREA. CONFIDENCE IN THAT FORECAST IS
NOT HIGH...BUT I AM RELUCTANT TO DROP THE PROB30 GROUPS FROM THE
FORECASTS FOR LBF AND VTN SINCE THEY HAVE BEEN IN THE FORECASTS FOR
BOTH THE 00Z AND 06Z SCHEDULED TAF CYCLES. THE STATISTICAL OUTPUT
FROM THE TWO PRIMARY MODELS INDICATES THAT A MENTION OF
THUNDERSTORMS MIGHT BE APPROPRIATE. ANYWAY...THE HIGHEST PROBABILITY
OF THUNDERSTORMS IN CENTRAL AND WESTERN NEBRASKA IS THIS EVENING
00-06Z. OUTSIDE OF THUNDERSTORMS...FLIGHT CONDITIONS ARE LIKELY TO
BE UNRESTRICTED.
&&
.FIRE WEATHER...
THE CURRENT FORECAST DOESN/T HAVE ANY DAYS WITH CONDITIONS
REACHING CRITICAL FIRE WEATHER CRITERIA. SUNDAY MAY BE CLOSE WITH
BREEZY SOUTHERLY WINDS AND RELATIVE HUMIDITY FORECAST BETWEEN 15
AND 20 PERCENT OVER SOUTHWEST NEBRASKA. WILL NEED TO CONTINUE TO
WATCH FOR FIRE POTENTIAL OVER THE NEXT WEEK AS THE HEAT AND DRY
WEATHER CONTINUE.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
DISCUSSION/FIRE WEATHER...BROOKS
AVIATION...SPRINGER
AREA FORECAST DISCUSSION
NWS BISMARCK ND
359 AM CDT SAT JUN 30 2012
.SHORT TERM...TODAY THROUGH SUNDAY...
ONGOING SEVERE THUNDERSTORMS THIS MORNING IN NORTHWEST NORTH
DAKOTA AHEAD OF SHORTWAVE TROUGH NOW MIGRATING THROUGH SOUTH
CENTRAL SASKATCHEWAN. A SURFACE TROUGH WAS ELONGATED NORTH TO
SOUTH IN EASTERN MONTANA AND THIS IS FORECAST TO SLOWLY SHIFT EAST
THROUGH THE AFTERNOON. IT APPEARS THAT CONVECTION WILL CONTINUOUSLY
FORM ALONG AND AHEAD OF THIS TROUGH IN ASSOCIATION WITH THE UPPER
SHORTWAVE TODAY. LOCAL RADAR SHOWS CLUSTERS OF THUNDERSTORMS
IN NORTHWEST NORTH DAKOTA MOVING EAST. THE HRRR SUGGESTS THAT A
MORE LINEAR FORMATION WILL TAKE SHAPE BY SUNRISE. WILL BE WATCHING
THIS CLOSELY AS THE STRONGEST INSTABILITY PER SPC MESOSCALE ANALYSIS
RESIDES IN THE SOUTHWEST THROUGH SOUTH CENTRAL.
DURING THE LATE MORNING AND THROUGH THE AFTERNOON...AN INSTABILITY
AXIS ALONG THE TROUGH WITH MU CAPE OF AROUND 4000 J/KG AND 0-6KM
SHEAR OF 30 TO 40KT WILL LIKELY PRODUCE SOME ORGANIZED STORMS OVER
SOUTH CENTRAL NORTH DAKOTA TODAY. IN PARTICULAR WILL BE THE JAMES
RIVER VALLEY EXTENDING WEST TO BISMARCK. HAIL/WIND ARE THE MAIN
THREATS WITH A TORNADO THREAT IN THE JAMES RIVER VALLEY. THE
SEVERE THREAT SHOULD DIMINISH AFTER 00Z SUNDAY...HOWEVER A CHANCE
OF SHOWERS AND THUNDERSTORMS WILL CONTINUE THROUGH 06Z IN THE
SOUTHEAST.
ANY PRECIPITATION THAT CONTINUES PAST 06Z SUNDAY WILL BECOME
ISOLATED AND DISSIPATE. THE NEXT ROUND OF THUNDERSTORMS...WHICH
ARE FORECAST TO BECOME SEVERE PER SPC DAY 2 OUTLOOK...WILL BEGIN
TO SPROUT OVER WESTERN NORTH DAKOTA SUNDAY EVENING AND GROW
UPSCALE OVERNIGHT ALONG AND NORTH OF A WARM FRONT. OTHERWISE MOST
OF CENTRAL NORTH DAKOTA WILL BE IN FOR A HOT/HUMID SUNDAY WITH
HIGHS BETWEEN 85F AND 95F.
.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY...
NORTH DAKOTA WILL REMAIN IN AN ACTIVE SUMMERTIME PATTERN THROUGH THE
EXTENDED PERIOD. BROAD SOUTHWEST UPPER FLOW ALONG THE PERIPHERY OF A
DOME OF HIGH PRESSURE OVER THE CENTRAL AND SOUTHERN PLAINS WILL
PROVIDE AN ACTIVE THUNDERSTORM PATTERN THROUGH THE WORK WEEK.
DAYTIME HIGHS IN THE MID 80S TO MID 90S WITH DEWPOINTS IN THE 60S
AND LOWER 70S WILL PROVIDE A RIPE ATMOSPHERE FOR DAYTIME CONVECTION
THROUGH THE WEEK. A PERSISTENT LEE SIDE LOW WILL ALSO PROVIDE A
FOCUSING MECHANISM FOR CONVECTION OVER EASTERN MONTANA THAT COULD
DEVELOP INTO THUNDERSTORM COMPLEXES THAT TRACK INTO NORTH DAKOTA
DURING THE LATE EVENINGS AND OVERNIGHT. DETERMINISTIC MODELS ARE IN
AGREEMENT IN THE OVERALL PATTERN. THERE ARE AS USUAL SOME TIMING AND
PLACEMENT ISSUES...HOWEVER SEE NO NEED TO DEVIATE FROM A CONSENSUS
MODEL BLEND WITH PERSISTENCE AT THIS TIME.
THIS RESULTS IN A HOT AND MUGGY HOLIDAY WEEK WITH THUNDERSTORM
CHANCES EACH DAY THROUGH THE WEEK...WITH SEVERE STORMS POSSIBLE
PRETTY MUCH EVERY DAY.
&&
.AVIATION...A COLD FRONT WILL MOVE ACROSS WESTERN AND CENTRAL NORTH
DAKOTA TODAY. SOUTH TO SOUTHEAST FLOW AHEAD OF THE FRONT WILL TURN
NORTHWEST WITH ITS PASSAGE. CURRENTLY CONVECTION ACROSS NORTHWEST
AND CENTRAL NORTH DAKOTA MOVING EAST...WITH POSSIBLE CONVECTION
CONTINUING THROUGH THE DAY AHEAD OF THE FRONT. VFR CONDITIONS ARE
EXPECTED EXCEPT FOR BRIEF MVFR-IFR VISIBILITIES AND CEILINGS IN
THUNDERSTORM ACTIVITY. THINGS SHOULD QUIET DOWN TONIGHT BEHIND THE
FRONT. SOME PATCHY FOG IS POSSIBLE LATER TONIGHT UNDER LIGHT WINDS
AND CLEAR TO PARTLY CLOUD SKIES.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KS
LONG TERM/AVIATION....TWH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1209 AM CDT SAT JUN 30 2012
.DISCUSSION...LATEST REGIONAL RADAR SHOWS A BROKEN LINE OF
CONVECTION STRETCHING FROM WILLISTON SOUTHEAST INTO KILLDEER AND
APPROACHING BISMARCK. HAVE EXPANDED POPS SLIGHTLY FURTHER EAST TO
ACCOUNT FOR THIS. THUS FAR...ALL THUNDERSTORMS HAVE REMAINED
BELOW SEVERE WEATHER THRESHOLDS. EXPECTING AN INCREASE IN ACTIVITY
OVERNIGHT ESPECIALLY IN THE NORTH CENTRAL AS A SHORTWAVE WORKS
EAST FROM SOUTHWESTERN SASKATCHEWAN. THE HRRR DEVELOPS THIS AREA
OVERNIGHT AND FORMS ANOTHER LINE OF SHOWERS AND THUNDERSTORMS FROM
MINOT TO BISMARCK BY 12Z. FORECAST REMAINS ON TRACK FROM EARLIER.
&&
.AVIATION...30/06Z ISSUANCE...MAINTAINED VCTS MENTION AT ALL
SITES EXCEPT KDIK FOR THE OVERNIGHT HOURS INTO SATURDAY MORNING.
KISN/KMOT/KBIS CAN EXPECT THE MAIN IMPACTS...AND HAVE ALSO FRAMED
A 2-3 HOUR TEMPO GROUP FOR TSRA FOR MOST LIKELY PERIOD OF STORMS.
WINDS WILL BECOME NORTHWEST BEHIND COLD FRONT...BEGINNING AT KISN
AROUND 11Z.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
DISCUSSION...KS
AVIATION...RK
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
335 AM EDT SAT JUN 30 2012
.SYNOPSIS...
A STATIONARY FRONT ACROSS CENTRAL OHIO WILL MEANDER NORTH AND
SOUTH TODAY AND TONIGHT. HIGH PRESSURE WILL MOVE ACROSS THE LOCAL
AREA SUNDAY FORCING THE FRONT SOUTH INTO THE LOWER OHIO VALLEY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SATELLITE SHOWS MCS TO OUR WEST WITH RADAR SHOWING PRECIP ABOUT TO
MOVE INTO NWRN OHIO. HRRR SHOWS THIS ACTIVITY WEAKENING BUT CONTINUING
EAST ACROSS THE AREA THROUGH THE EARLY MORNING HOURS. WILL HAVE
LIKELY POPS FOR THE MORNING WEST BUT FOR NOW WILL HAVE CHANCE
POPS FURTHER EAST. MAY NEED TO INCREASE POPS FURTHER EAST IF
SYSTEM DOESN`T DISSIPATE OR PROPAGATE SOUTHEAST. DO EXPECT
CONVECTION TO WEAKEN/DISSIPATE BY MID MORNING AS THESE SYSTEMS
USUALLY DO. FOR THE AFTERNOON...WILL HAVE CHANCE POPS FOR THE
AREA. INSTABILITY DOES REACH INTO THE AREA BUT BEST VALUES
FORECAST TO BE TO THE SOUTH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
SUNDAY THROUGH TUESDAY MODELS SHOW A SLIGHT AMPLIFICATION OF THE
UPPER PATTERN WITH HEIGHTS BUILDING ACROSS THE NATIONS MIDSECTION
WHILE HEIGHTS FALL ACROSS THE CANADIAN AND NEW ENGLAND COAST.
INITIALLY SLIGHTLY COOLER AIR DROP INTO THE AREA TONIGHT AND
SUNDAY AS THE STATIONARY FRONT ACROSS CENTRAL OHIO SAGS SOUTH.
850MB TEMPS DROP FROM AROUND 20C TO 16C BY SUNDAY 12Z. AS HEIGHTS
BUILD IN THE PLAINS THE FRONT WILL RETURN WARM AND CROSS THE AREA
WITH THE GRADIENT INCREASING NORTHEAST OF THE AREA MONDAY INTO
TUESDAY AS THE TROF SAGS ALONG THE COAST. SHOULD GET A SLIGHT COOL
DOWN NORTHEAST QUARTER OF THE AREA SUNDAY WITH TEMPS REBOUNDING TO
THE UPPER 80S AND LOWER 90S MONDAY AND TUESDAY. WILL KEEP FORECAST
DRY SUNDAY AS HIGH PRESSURE BUILDS ACROSS THE AREA. MONDAY THE
WARM FRONT WILL MOVE BACK ACROSS THE AREA SO WILL HAVE LOW CHANCE
POPS. TUESDAY NIGHT WILL HAVE A LOW CHANCE POP NORTHEAST INVOF
BEST MOISTURE AND THE WARM FRONT.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
HERE WE GO AGAIN IN THIS UP AND DOWN SUMMER OF HEAT. UPPER LEVEL
PATTERN TRENDING TOWARD ANOTHER SURGE IN THE UPPER LEVEL RIDGE OVER
MUCH OF THE CENTRAL UNITED STATES. LARGE DOME OF HIGH PRESSURE
DEVELOPS OVER MISSOURI AND THIS MEANS STRONG SUBSIDENCE WILL
CONTINUE AND THEREFORE BRING BACK A RETURN TO HOT TEMPERATURES TO
THE FORECAST AREA. THE UPPER LEVEL HIGH PRESSURE CENTER SHIFTS EAST
ACROSS THE GREAT LAKES REGION BY FRIDAY MORNING.
A SERIES OF VORTICITY MAXIMUMS WILL ROTATE SOUTHEAST ON THE EAST
SIDE OF THE HIGH PRESSURE CENTER. THE VORTICITY MAXIMUMS WILL HAVE
SOME LIMITED MOISTURE ASSOCIATED WITH THEM AS THEY MOVE THROUGH THE
AREA WEDNESDAY AND THURSDAY. THEREFORE...WILL NEED TO KEEP THE
MENTION FOR SHOWERS AND THUNDERSTORMS GOING WEDNESDAY INTO THURSDAY.
AS UPPER LEVEL HIGH PRESSURE SETTLES IN OVER THE FORECAST AREA...SO
WILL THE SUBSEQUENT SURFACE HIGH PRESSURE. THIS WILL RESULT IN A
RETURN TO HOT DRY WEATHER LEADING INTO THE WEEKEND.
TEMPERATURES EXPECTED TO CLIMB INTO THE UPPER 80S TO LOWER 90S AGAIN
NEXT WEEK FOR HIGHS WITH 60S AND 70S FOR LOWS.
&&
.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
FIRST NOTE IS MANSFIELD AND FINDLAY SYSTEMS ARE OUT AND WILL NOT
HAVE ASOS DATA FOR AMENDMENTS. SO...HAD TO GO WITH AMENDMENT NOT
SCHEDULED.
UPPER LEVEL GUIDANCE SHOWS A RATHER POTENT VORTICITY MAXIMUM
MOVING EAST TOWARD THE AREA. THE LATEST EUROPEAN MODEL SHOWS THIS
FEATURE WILL RACE EAST ACROSS NORTHERN OHIO AND LAKE ERIE THIS
MORNING AND EARLY AFTERNOON.
LATEST RADAR IMAGERY SHOWS MESO CONVECTIVE SYSTEM MOVING SLOWLY
EAST ACROSS NORTH INDIANA AT THIS TIME. TRENDS HAVE BEEN SHOWING
SOME CYCLING BETWEEN WEAKENING AND STRENGTHENING. LATEST SPC
GUIDANCE SUGGESTS THIS LINE WILL MOVE INTO A LESS FAVORABLE
ENVIRONMENT COMPARED TO THE CURRENT LOCATION. THERE IS SOME
INDICATION THAT MORE FAVORABLE AIR IS TRYING TO SURGE NORTH AHEAD
OF THE SYSTEM. DUE TO THE TIMING OF THE FEATURE AROUND 12Z IN THE
MORNING IN TOLEDO AND WITH DAY TIME HEATING STARTING...SOME
FUELING AHEAD OF THE SYSTEM SHOULD TAKE PLACE. UPPER LEVEL
GUIDANCE ALSO SUGGESTS A STRENGTHENING OF THE VORTICITY MAXIMUM AS
IT MOVES INTO OHIO.
FOR NOW WILL MENTION GENERAL THUNDER WITH THE FEATURE AS IT MOVES
EAST ACROSS THE AREA DURING THE MORNING HOURS. WILL NOT MENTION
ANY PROBLEMS AT ERIE AS THE FEATURE COULD TURN SOUTH OF ERIE. WILL
MONITOR TRENDS TO SEE HOW THINGS GO ON WHETHER TO ADD THUNDER AT ERIE.
OTHERWISE...VFR CONDITIONS REST OF THE TAF PERIOD WITH WINDS
BECOMING LIGHT AFTER 00Z.
.OUTLOOK...VFR CONDITIONS WILL PREVAIL EXCEPT FOR A THREAT OF
SHOWERS/THUNDERSTORMS SATURDAY NIGHT AND SUNDAY AND AGAIN ON MONDAY.
&&
.MARINE...
LAKE IS EXPECTED TO REMAIN QUIET THROUGH THE PERIOD. NO STRONG
GRADIENT CHANGES EXPECTED SO WINDS ARE NOT EXPECTED TO BECOME A
PROBLEM AT THIS TIME.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TK
NEAR TERM...TK
SHORT TERM...TK
LONG TERM...LOMBARDY
AVIATION...LOMBARDY
MARINE...LOMBARDY
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
358 AM CDT SAT JUN 30 2012
.SHORT TERM...TODAY THROUGH MONDAY
MAIN THUNDERSTORM CLUSTER THIS MORNING IS ROLLING EAST ACROSS
NORTH DAKOTA WITH QUIET CONDITIONS OVER SOUTH DAKOTA. YESTERDAY
MORNING THE HRRR HANDLED MORNING CONVECTION VERY WELL. THIS
MORNING...HRRR IS SHOWING ANOTHER CLUSTER OF STORMS DEVELOPING
ACROSS WESTERN SOUTH DAKOTA OVER THE NEXT FEW HOURS...THEN PUSHES
AN AREA OF SCATTERED SHOWERS ACROSS THE STATE THROUGH THE DAY.
ALTHOUGH...UNLIKE YESTERDAY THERE IS REALLY NO NOTEWORTHY UPPER
WAVE TO THE WEST TO IGNITE ANYTHING. THIS SAID...MODELS ARE
INITIALIZING A VORT MAXIMA OVER WYOMING AND THERE IS SOME ACCAS
DEVELOPMENT OVER SOUTHEAST WYOMING. NOTHING CURRENTLY OVER WESTERN
SOUTH DAKOTA AT THIS TIME. HRRR MAY BE OVERDOING THINGS THIS
MORNING BUT WILL MONITOR CLOSELY. CURRENTLY HAVE SLIGHT CHANCE
POPS UP THROUGH 12Z AND DRY CONDITIONS FOR THE MOST PART AFTER
THAT UNTIL LATER THIS AFTERNOON. IF ACCAS/PRECIP DEVELOPS OVER THE
WESTERN PART OF THE STATE BY 12Z...WILL HAVE TO RETHINK CURRENT
PRECIP FORECAST FOR THE AFTERNOON HOURS.
FOR LATER TODAY...FRONTAL BOUNDARY WILL APPROACH THE CENTRAL
DAKOTAS WITH MODERATE TO STRONG INSTABILITY DEVELOPING. 40 TO 50
KNOTS OF SHEAR AVAILABLE WITH THE HIGHEST VALUES OVER NORTHEAST
SOUTH DAKOTA INTO EASTERN NORTH DAKOTA. STRONGEST CAPPING IS
EVIDENT OVER THE NORTHEAST CWA THIS AFTERNOON...WITH WEAKEST
REGION FURTHER WEST NEAR THE FRONTAL BOUNDARY. HI RES MODELS
INDICATING SCT STORM DEVELOPMENT LATE THIS AFTERNOON/EARLY EVENING
ACROSS DIFFERENT PARTS OF THE REGION. CONVECTIVE TRENDS STILL
RATHER DIFFICULT TO NAIL DOWN TODAY THOUGH.
HOT AND HUMID CONDITIONS WILL CONTINUE THROUGH THE SHORT TERM
PERIOD...WITH THE HOTTEST TEMPS EXPECTED ON MONDAY. IMPRESSIVE
THERMAL RIDGE SETS UP RIGHT OVER THE AREA BY MONDAY AFTERNOON.
TEMPS WILL BE WELL INTO THE 90S WITH SOME AREAS AROUND 100
DEGREES. HUMIDITY WILL COME ALONG WITH THIS. COULD BE LOOKING AT
POSSIBLY HEAT ADVISORY HEADLINES IN THE NEXT DAY OR SO.
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY
THE UPPER LEVEL RIDGE WILL HOLD TIGHT OVER THE PLAINS THROUGH MOST
OF THE PERIOD. BY FRIDAY...IT GETS DAMPENED SOME AS A SHORTWAVE
TRACKS ACROSS THE DAKOTAS WITH THE FLOW BECOMING MORE ZONAL. THE
MODELS CONTINUE TO SHOW SPATTERINGS OF PRECIPITATION THROUGHOUT
THE ENTIRE PERIOD AS A SERIES OF FRONTAL BOUNDARIES TRACK ACROSS
THE PLAINS. BIGGEST HINDRANCE TO PRECIPITATION FORMATION WILL BE A
STRONG CAPPING INVERSION THAT WILL BE IN PLACE IN ASSOCIATION WITH
THE UPPER RIDGE. COOLER MID LEVEL TEMPERATURES MOVE IN ON FRIDAY
ALONG WITH THE AFOREMENTIONED UPPER SHORTWAVE. THEREFORE...LOOKS
AS THOUGH THE BEST CHANCE FOR PRECIPITATION WILL COME FRIDAY AND
FRIDAY NIGHT. WILL STICK CLOSE TO THE ALLBLEND SOLUTION...KEEPING
A SLIGHT CHANCE OF PRECIPITATION SOMEWHERE OVER THE CWA MONDAY
NIGHT THROUGH THURSDAY NIGHT...THEN WILL GO WITH CHANCE POPS AT
THE END OF THE PERIOD.
TEMPERATURES WILL BE VERY WARM THROUGH THE ENTIRE PERIOD UNDER THE
INFLUENCE OF THE RIDGE. H85 TEMPERATURES IN THE MID TO UPPER 20S
CELSIUS WILL TRANSLATE TO AFTERNOON HIGH TEMPERATURES IN THE 90S
AND OVERNIGHT LOW TEMPERATURES IN THE UPPER 60S TO MID 70S.
WEDNESDAY AND THURSDAY LOOK TO BE THE WARMEST DAYS...WITH PORTIONS
OF THE CENTRAL AND WESTERN CWA EXPECTED TO SEE MID TO UPPER
90S...WITH A FEW SPOTS LIKELY TO SEE 100+ DEGREE TEMPERATURES.
&&
.AVIATION...
06Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
VFR CONDITIONS ARE EXPECTED AT ALL TERMINALS THROUGH TONIGHT AND
SATURDAY. AN UPPER SHORT WAVE TROUGH WILL BE LIFTING INTO THE
REGION LATER TONIGHT AND SATURDAY. THIS FEATURE ALONG WITH A WEAK
SURFACE FRONTAL BOUNDARY MOVING ACROSS THE REGION WILL BRING
ANOTHER ROUND OF SCATTERED SHOWERS AND THUNDERSTORMS. TO
HIGHLIGHT THE POSSIBILITY OF THUNDER HAVE INSERTED VCTS IN ALL
TAFS.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
SHORT TERM...TMT
LONG TERM...PARKIN
AVIATION...PARKIN
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1029 PM MDT FRI JUN 29 2012
.AVIATION...
MOSTLY VFR LATE TONIGHT...BUT WITH POTENTIAL FOR SCATTERED
THUNDERSTORMS DEVELOPING OVER ESPECIALLY THE SOUTHERN PORTIONS OF
THE FORECAST AREA AROUND SUNRISE AS A WEAK TROF ALOFT APPROACHES.
THIS DEVELOPMENT IS SUPPORTED BY BOTH THE 00Z NAM AND THE LATEST
RUN OF THE HRRR MODEL...THOUGH DETAILS DIFFER. A SECOND ROUND OF
CONVECTION IS LIKELY MID TO LATE AFTERNOON WITH A SECOND
TROF...THOUGH TIMING IS UNCERTAIN. A FEW OF THE STORMS MAY BE
SEVERE...ESPECIALLY THOSE IN THE AFTERNOON OVER SOUTHERN PORTIONS
OF THE AREA. MVFR CIGS AND VSBYS AND GUSTY SFC WINDS MAY ACCOMPANY
ANY OF THE STORMS.
&&
.PREV DISCUSSION... /ISSUED 221 PM MDT FRI JUN 29 2012/
DISCUSSION...WATER VAPOR SHOWS PERSISTENT UPPER RIDGE EXTENDING
THROUGH THE ROCKIES...WITH SHORT WAVE THAT BROUGHT LAST NIGHTS
CONVECTION SHIFTING INTO THE UPPER MIDWEST. AT THE SURFACE...A
NEARLY STATIONARY FRONT EXTENDS FROM SERN MT THROUGH THE NEB
PANHANDLE.
TONIGHT...A WEAK SURFACE LOW ALONG THE STATIONARY BOUNDARY COULD
PROVIDE JUST ENOUGH CONVERGENCE FOR AN ISOLD TSTM IN OUR NWRN
ZONES...BUT LARGE SCALE SUBSIDENCE WITH UPPER RIDGE SHIFTING EWD
SHOULD BRING DRY AND MILD CONDITIONS.
SATURDAY...SHORT WAVE TROF CURRENTLY MOVING INTO UT WILL TOP THE
UPPER RIDGE AND INTERACT WITH A STATIONARY SFC BOUNDARY SETTING UP
ACROSS OUR SRN ZONES FOR A FEW AFTN/EVE TSTMS. SHEAR IS NOT OVERLY
IMPRESSIVE...BUT ENOUGH FOR A FEW STRONG/SVR STORMS MAINLY SOUTH
OF I-90. TEMPS WILL ONCE AGAIN BE QUITE HOT WITH UPPER RIDGE AXIS
JUST TO OUR WEST.
SUNDAY...THIS WILL LIKELY BE THE HOTTEST DAY OF THE WEEKEND WITH
UPPER RIDGE AXIS SHIFTING EWD INTO WRN SD...WITH MANY LOCATIONS
REACHING NEAR THE CENTURY MARK. SMALL CHANCES FOR TSTMS POSSIBLE
ONCE AGAIN MAINLY IN THE AFTN/EVE HOURS. BEST CHANCES WILL BE
ACROSS OUR WRN TWO-THIRDS ZONES AS SURFACE TROF PUSHES THROUGH WY
DURING THE AFTN AND INTO THE WRN DAKOTAS OVERNIGHT.
EXTENDED...AN UPPER LEVEL RIDGE WILL DOMINATE THE WEATHER FOR THE
LONG TERM. PERIODIC WEAK DISTURBANCES WILL RIDE ACROSS THE RIDGE
BRINGING NEAR DAILY ISOLATED CHANCES FOR -TSRA TO VARYING PARTS OF
THE AREA. TEMPERATURES WILL REMAIN WELL ABOVE AVERAGE WITH HIGHS
GENERALLY IN THE 90S TO AROUND 100.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...JOHNSON
LONG TERM....13
AVIATION...BARBER
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
314 AM CDT SAT JUN 30 2012
.SHORT TERM...
UA HIGH PRESSURE MAXIMA LOCATED ACROSS ARIZONA/NEW MEXICO AND THE
SERN CONUS...IN ADDITION TO A CONTINUAL WESTWARD RETROGRADING UA LOW
ACROSS SERN TEXAS...WAS THE SYNOPTIC SETUP THIS MORNING...AND WILL
PERSIST THROUGH THE SHORT TERM PERIOD. AS SUCH...A GENERAL WEAKNESS
IN THE HEIGHT FIELDS WILL EXIST FOR THE SOUTHERN PLAINS...WHICH WILL
ALLOW FOR TEMPS TO BE NOTABLY COOLER THAN YESTERDAY...ALBEIT STILL
WARM WITH A TEMP RANGE OF 95-101 ANTICIPATED.
THE SYNOPTIC PATTERN HAS ALLOWED FOR THE MONSOONAL MOISTURE TO SHIFT
SOUTH AND EAST ACROSS THE SOUTHERN PLAINS...OR BASICALLY EAST OF THE
UA RIDGE THAT IS ACROSS ARIZONA/NEW MEXICO. A SFC TROUGH NORTH OF
THE REGION COMBINED WITH THIS MONSOONAL MOISTURE HAS RESULTED IN
SCATTERED SHOWERS AND AN ISOLATED THUNDERSTORM OR TWO THAT DEVELOPED
ACROSS THE SOUTHWESTERN TEXAS PANHANDLE YESTERDAY EVENING...AND PER
0730Z RADAR ANALYSIS IS NOW MOVING SSE ACROSS YOAKUM AND TERRY
COUNTIES /AT LEAST WHAT IS LEFT OF IT/. IT IS OF NOTE TO ALSO
MENTION A LINE OF SHOWERS AND THUNDERSTORMS THAT HAVE DEVELOPED FROM
EASTERN LYNN TO NORTHEASTERN CROSBY COUNTY...COINCIDING WITH BETTER
DEWPOINTS....AND A SOUTHEASTWARD MOVING OUTFLOW BOUNDARY THAT HAS
INDUCED ADDITIONAL LIGHT ECHOES ACROSS FLOYD AND MOTLEY COUNTIES.
WOULD NOT BE OUT OF THE QUESTION FOR SOME LOCATIONS WITHIN THE LINE
OF HEAVIEST SHOWERS AND THUNDERSTORMS TO ACCUMULATE A FEW TENTHS OF
AN INCH OF RAINFALL...FOR THE MERE FACT OF TRAINING OCCURRING. THE
LINE OF STORMS WAS MOVING TO THE SW ACROSS THE PERMIAN BASIN WHICH
IS INDICATIVE OF THE UA RIDGE/S INFLUENCE. THE RUC SOLUTION IS BEST
HANDLING THE ADDITIONAL PRECIP DEVELOPMENT ALBEIT...A BIT MORE
AGGRESSIVE IN REGARD TO COVERAGE. HOWEVER THE RUC DOES SHOW PRECIP
DISSIPATED BY AOA 15Z AND HAVE THEREFORE ADDED SLIGHT CHANCE POPS
ACROSS THE SAID AREAS UNTIL 15Z.
FORECAST SOLUTIONS HINT AT THE MONSOONAL MOISTURE PERSISTING ACROSS
THE WESTERN PANHANDLES AND THE WESTERN SOUTH PLAINS TODAY. A SFC
TROUGH NNW OF THE FA AND A CONTINUED EASTERLY UPSLOPE REGIME WILL
LEAD TO THE LOGICAL CONCLUSION OF A REPEAT SCENARIO OF STORMS
DEVELOPING ACROSS THE WESTERN PANHANDLES...EASTERN NEW MEXICO AND
WESTERN SOUTH THIS AFTERNOON/EVENING. A CAPPING INVERSION IS NOTED
OFF THE CAPROCK...BUT THAT IS NOT THE CASE ON THE CAPROCK...AS
STEEPENED LAPSE RATES WITH LITTLE TO NO CIN IS EXHIBITED BY MODEL
SOUNDINGS. FURTHERMORE...THE SFC-BASED CAPE IS A LITTLE BETTER TODAY
THAN YESTERDAY /AOA 700 J/KG/ WITH PROGGED 0-6 KM BULK SHEAR OF 25
KTS /SIMILAR TO YESTERDAY/. THERE ARE SLIGHT HINTS OF A WEAKNESS OF
MID LEVEL WINDS WHICH IS EVIDENT OF THE UA RIDGE REMAINING AN
INFLUENCE. A MITIGATING FACTOR THAT STANDS OUT IS THAT THE
STEERING FLOW WILL BE FROM THE NORTHEAST...WHICH COULD AID TO
PREVENT STORMS FROM STAYING IN THE CWA FOR LONG PERIODS OF TIME.
HOWEVER...THE AFOREMENTIONED INDICES CAN NOT BE IGNORED WHERE AN
ISOLATED STRONG THUNDERSTORM WITH LCL/S AOA 10KFT SUGGEST THE MAIN
THREAT TO BE GUSTY WINDS. WILL THEREFORE CONTINUE A SLIGHT CHANCE
MENTION ACROSS THE WEST AND NW ZONES THIS AFTERNOON THROUGH TONIGHT.
&&
.LONG TERM...
NO SIG CHANGES MADE TO THE LONG TERM PORTION OF THE FCST. UPPER
LEVEL INVERTED TROUGH TO MOVE ACROSS WEST CENTRAL TEXAS SUNDAY
WITH POTENTIAL FOR SOME ISOLATED SHRA OR TSRA MAKING IT INTO THE
SERN ZONES...ALTHOUGH CHANCES STILL LOOK TOO SMALL TO MENTION IN
THE FCST ATTM. AS THE TROUGH CONTINUES TO MOVE WWD THE CENTER OF
THE UPPER RIDGE WILL RETROGRADE TAKING DEEPER MOISTURE WITH IT
MINIMIZING RAIN CHANCES ACROSS THE WRN ZONES SUNDAY. ON THE
POSITIVE SIDE...FURTHER DECREASES IN HEIGHTS AND THICKNESSES WILL
TRANSLATE INTO COOLER TEMPERATURES AGAIN SUNDAY...MAINLY LOWER TO
MIDDLE 90S.
EARLY IN THE WEEK THE WRN PORTION OF THE UPPER RIDGE THAT WILL BE
DOMINATING MUCH OF THE CONUS WILL BEGIN TO EXPAND NEWD TOWARD THE
CENTRAL PLAINS. FCST AREA WILL REMAIN ON THE SOUTH OR SOUTHEAST
FLANK OF THE CENTER WITH RELATIVELY WEAKER HEIGHTS AND EASTERLY
FLOW IN PLACE ACROSS THE REGION. MAY SEE THE DEEPER MONSOONAL EDGE
BACK TO THE EAST BY THE END OF THE WEEK...ALTHOUGH TOO EARLY TO
MENTION ANY RAIN POTENTIAL. PATTERN SHOULD HELP THE AREA AVOID THE
EXTREME HEAT OF EARLIER THIS WEEK...ALTHOUGH WILL CONTINUE TO RUN
ABOVE SEASONAL NORMALS THROUGH THE FCST PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 96 65 91 63 90 / 20 20 10 10 0
TULIA 95 67 90 66 89 / 20 20 0 0 0
PLAINVIEW 95 68 91 67 90 / 10 10 0 0 0
LEVELLAND 96 68 91 66 92 / 20 10 0 0 0
LUBBOCK 97 69 92 68 92 / 10 10 0 0 0
DENVER CITY 96 68 91 66 90 / 20 10 10 10 0
BROWNFIELD 97 69 91 67 91 / 20 10 10 10 0
CHILDRESS 100 71 96 70 95 / 10 0 0 0 10
SPUR 98 70 93 71 92 / 10 0 10 10 10
ASPERMONT 100 71 95 70 96 / 10 0 10 10 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
29/07
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
455 AM CDT SAT JUN 30 2012
.SHORT TERM...TODAY THROUGH MONDAY NIGHT
327 AM CDT SAT JUN 30 2012
MAIN FORECAST CONCERNS REMAIN TO BE PRECIPITATION CHANCES
THROUGHOUT AS WELL AS HEAT INDICES ON MONDAY.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED SUBTROPICAL RIDGING STILL DOMINATING MUCH OF THE SOUTHERN
U.S....WITH RIDGING COMING OFF OF THIS EXTENDING FROM THE FOUR
CORNERS REGION INTO ALBERTA AND SASKATCHEWAN. THE FORECAST AREA LIES
IN NORTHWEST FLOW DOWNSTREAM OF THIS RIDGE EXTENSION. WITHIN THE
NORTHWEST FLOW...SHORTWAVES ARE EVIDENT OVER OVER THE FORECAST AREA
AS WELL AS BACK OVER THE DAKOTAS. THE SHORTWAVE OVER THE FORECAST
AREA HAD SOME SHOWERS AND EMBEDDED THUNDERSTORMS WITH IT LAST
EVENING WHEN IT WAS OVER SOUTHWEST MINNESOTA...BUT NOW MOST OF WHAT
IS LEFT IS SOME MID CLOUDS. WITH THE SHORTWAVES BACK OVER THE
DAKOTAS...SOME SHOWERS AN STORMS ARE NOTED OVER CENTRAL NORTH
DAKOTA. OTHER CONVECTION OF INTEREST IS OVER SOUTHERN IOWA...
SITUATED JUST TO THE NORTH OF A STATIONARY FRONTAL BOUNDARY OVER
NORTHERN MISSOURI. THIS CONVECTION IS BEING AIDED BY INCREASE
925-850MB MOISTURE TRANSPORT COMING UP THROUGH EASTERN KANSAS AND
WESTERN MISSOURI. REGARDING MOISTURE...IT IS INTERESTING TO NOTE
THAT PER 00Z SOUNDINGS...THE AMOUNT OF MOISTURE ALONG THE BOUNDARY
IN THE ATMOSPHERE LOOKS TO HAVE DIMINISHED. AT DVN AND OAX...THE
PRECIPITABLE WATER HAS DROPPED TO AROUND 1.6 INCHES OR 150 PERCENT
OF NORMAL...COMPARED TO THE AROUND 2 INCHES OR 200 PERCENT OF NORMAL
SEEN ON THE 29TH AT 00Z. THIS MIGHT BE A RESULT OF THE VARIOUS
ROUNDS OF CONVECTION THAT HAVE ROLLED THROUGH OVER THE PAST 24
HOURS. PRECIPITABLE WATER HAS COME UP TO NEAR 1 INCH AT MPX AND
ABR...BUT THE SOUNDINGS REMAIN FAIRLY DRY...THUS THE CLEAR SKIES AT
BOTH LOCATIONS.
TODAY AND TONIGHT...FORECAST AREA LOOKS TO REMAIN IN THE NORTHWEST
FLOW ALOFT...THOUGH THE FLOW DOES BACK SLIGHTLY IN RESPONSE TO
RIDGING OVER THE NORTHERN ROCKIES PUSHING EAST. THE UPPER LEVEL FLOW
WILL ALLOW THE SHORTWAVES OVER THE DAKOTAS TO PASS ACROSS THE AREA
BETWEEN 18-03Z. NOT THAT THRILLED ABOUT THE PRECIPITATION CHANCES
WITH THESE SHORTWAVES...PRIMARILY BECAUSE THE MAIN INSTABILITY AND
MOISTURE REMAIN STUCK TO THE SOUTH ACROSS SOUTHERN IOWA CLOSER TO
THE STATIONARY FRONTAL BOUNDARY. IN ADDITION...PRETTY MUCH ALL
GUIDANCE HAS TODAY AND TONIGHT DRY...INCLUDING SURPRISINGLY THE GFS
WHICH HAS BEEN TOO ACTIVE WITH PRECIPITATION. 00Z HIRES ARW RUN HAS
A GOOD HANDLE ON THE CONVECTION OVER NORTH DAKOTA AND HAS IT DIE
BEFORE IT REACHES HERE...WHICH SEEMS REASONABLE SINCE IT IS GOING
INTO A STABLE ENVIRONMENT. THEREFORE...HAVE PULLED PRECIPITATION
CHANCES FOR TODAY AND TONIGHT. SOUNDINGS TOO LOOK FAIRLY DRY AND
CAPPED AROUND 800MB. WE SHOULD SEE A LOT MORE SUNSHINE TODAY WITH
NOT AS MUCH CONVECTIVE BLOW-OFF. SOME MID CLOUDS MAY COME IN LATE
WITH THE APPROACH OF THE SHORTWAVES...BUT NOT ENOUGH TO HAMPER
HEATING. 850MB TEMPS OF 16C NORTH TO 20C SOUTH SUPPORT HIGHS IN THE
MID 80S TO LOWER 90S. MOST OF TONIGHT LOOKS MOSTLY CLEAR...THOUGH
SOME MID CLOUDS MAY COME INTO WESTERN PORTIONS OF THE FORECAST AREA
AFTER MIDNIGHT. LOWS SHOULD GENERALLY BE IN THE 60S...THOUGH THE
TYPICAL COOL SPOTS OF WISCONSIN MAY BE ABLE TO DIP INTO THE UPPER
50S.
SUNDAY AND SUNDAY NIGHT...THE UPPER RIDGING OVER THE NORTHERN
ROCKIES LOOKS TO GET A BETTER PUSH EASTWARD DURING THIS PERIOD...DUE
TO TROUGHING CURRENTLY OFF THE WEST COAST LIFTING INTO THE NORTHERN
ROCKIES. THE RESPONSE TO THE EASTWARD MOVEMENT TO THE UPPER RIDGE IS
TO INCREASE LOW LEVEL SOUTHERLY FLOW OVER THE PLAINS...WHICH MEANS
THAT STATIONARY FRONT IS GOING TO LIFT NORTH AS A WARM FRONT. AT
LEAST FOR SUNDAY...THE FRONT SHOULD STAY SOUTH OF THE AREA...KEEPING
THE BULK OF THE PRECIPITATION ON IT TO THE SOUTH. DID KEEP SOME 20
PERCENT CHANCES IN SOUTH OF I-90 FOR SUNDAY AS A BUFFER. LOOKS LIKE
WE WILL STILL HAVE TO CONTEND WITH MID CLOUDS...ESPECIALLY IN THE
MORNING WHEN THE BEST ISENTROPIC LIFT IS OCCURRING ON THE 315K
SURFACE. BETTER SURGE NORTHWARD OF THE WARM FRONT LOOKS TO OCCUR
SUNDAY NIGHT. HOW FAST VARIES FROM MODEL TO MODEL...WITH THE 30.00Z
NAM HAVING IT REACH I-94 COMPARED TO ONLY NORTHEAST IOWA AT MOST FOR
THE 30.00Z GFS/ECMWF. THIS IS CRITICAL TO SOME DEGREE SINCE
INCREASING MOISTURE TRANSPORT ABOVE THE FRONT COULD RESULT IN
ELEVATED CONVECTION. CONFIDENCE IN CONVECTION IS LOW SINCE IT IS
HARD AT THIS POINT TO FIND ANY FOCUSED AREAS OF MOISTURE TRANSPORT.
HOWEVER... SYNOPTICALLY THE SCENARIO CAN FAVOR CONVECTION. FOR NOW
STAYED WITH THE PREVIOUS FORECAST OF 20 PERCENT CHANCES. WITH WARMER
AIR MOVING IN...NOTED BY 850MB TEMPS CLIMBING TO AROUND 20C BY 18Z
SUNDAY...ANTICIPATE HIGHS A FEW DEGREES WARMER THAN TODAY. SIMILAR
SITUATION WITH LOWS...GIVEN WARMER AND MORE HUMID AIR WILL RESULT IN
WARMER TEMPERATURES AT NIGHT.
MONDAY AND MONDAY NIGHT...UPPER RIDGING LOOKS TO CONTINUE TO BUILD
NORTHEASTWARD TOWARDS THE FORECAST AREA...KEEPING A SOUTHWEST LOW
LEVEL WARM ADVECTION PATTERN IN PLACE. DIFFERENCES STILL REMAIN ON
THE NORTHWARD SPEED OF THE WARM FRONT. HOWEVER...BY 00Z TUESDAY MOST
OF THE MODELS COME INTO AGREEMENT OF A POSITION AT LEAST NEAR I-94.
INSTABILITY ALONG THE FRONT COMBINED WITH THE WEAK FRONTAL
CONVERGENCE COULD PROVE ENOUGH TO TRIGGER CONVECTION. THERE ARE
INDICATIONS OF A WEAK SHORTWAVE MOVING THROUGH TOO. IF THIS DOES NOT
COME THROUGH...700MB TEMPS ARE PROGGED TO INCREASE THROUGH THE
DAY...TOWARDS 11C OR SO BY THE END OF THE DAY...WHICH COULD
EFFECTIVELY CAP CONVECTION ON THE FRONT. GIVEN THIS UNCERTAINTY AND
POTENTIAL FOR CAPPING...STILL ONLY KEPT PRECIPITATION CHANCES IN THE
30-40 RANGE FOR MONDAY. CHANCES SHIFT NORTHEAST AND LOWER TO 20-30
WITH THE WARM FRONT LIFTING PERHAPS ALL THE WAY THROUGH THE FORECAST
AREA. 850MB TEMPS WARM TO 20-23C ON MONDAY WHICH WOULD SUPPORT HIGHS
IN THE UPPER 80S TO MID 90S. IF THE 30.00Z NAM/UKMET ARE RIGHT WITH
THE WARM AIR COMING IN...SUGGESTING 24-26C 850MB TEMPS POSSIBLE...
HIGHS COULD BE WARMER YET. ONE CONCERN WITH THE FRONT IN THE AREA IS
THE HIGHER DEWPOINTS AROUND 70 ACCOMPANYING IT. THESE DEWPOINTS
COMBINED WITH THE FORECAST HIGH TEMPERATURES MAY RESULT IN HEAT
INDICES AROUND 100 IN VALLEY AREAS AND IN NORTHEAST IOWA. THUS...A
HEAT ADVISORY MAY BE NEEDED. WARM NIGHT LIKELY MONDAY NIGHT BEING
MOSTLY SOUTH OF THE FRONT. 70S ARE LIKELY FOR LOWS.
IF CONVECTION OCCURS SUNDAY THROUGH MONDAY NIGHT...0-6 KM SHEAR
IS MOSTLY BELOW 30 KTS. THEREFORE...NOT OVERLY CONCERNED ABOUT
SEVERE WEATHER AT THIS POINT. STORMS COULD PRODUCE LOCALLY HEAVY
RAIN GIVEN DEEP WARM CLOUD DEPTHS...BUT AGAIN CONFIDENCE OVERALL
IS LOW ON CONVECTION IN THE FIRST PLACE.
.LONG TERM...TUESDAY THROUGH FRIDAY NIGHT
327 AM CDT SAT JUN 30 2012
BUILDING HEAT AND SMALL CHANCES FOR PRECIPITATION REMAIN MAIN
CONCERN FOR THE LONG TERM PERIOD.
30.00Z ECMWF/CANADIAN/GFS/GFS ENSEMBLES ALL SHOW THE CURRENT
SUBTROPICAL RIDGING OVER THE SOUTHERN U.S. EXPANDING ACROSS MUCH OF
THE U.S. DURING THIS PERIOD. HOWEVER...THERE ARE DEFINITELY SOME
ISSUES TO DEAL WITH. THE FIRST IS LATE TUESDAY INTO TUESDAY NIGHT
WHERE THE 30.00Z GFS...GFS ENSEMBLES AND CANADIAN SHOW A COLD FRONT
DROPPING SOUTHEAST THROUGH THE AREA...ASSOCIATED WITH A SHORTWAVE
CROSSING THE WESTERN GREAT LAKES. THE ECMWF HAS YET TO SHOW THIS
COLD FRONT COMING THROUGH. GIVEN THE MODEL SPLIT...FOR NOW KEPT THE
LOW PRECIPITATION CHANCES GOING. THE FRONT SHOULD NOT DROP TOO FAR
SOUTH OF THE AREA GIVEN THE BUILDING RIDGING. IN FACT...BY MID-DAY
THURSDAY...THE GFS...MAJORITY OF GFS ENSEMBLES AND ECMWF ALL SUGGEST
THE WARM FRONT WILL BE NORTH OF THE AREA. THIS WILL USHER IN THE
HEAT SEEN TO OUR SOUTH. LOOKS LIKE THE AIRMASS SHOULD BE CAPPED
ENOUGH SUCH THAT EVEN WITH THE WARM FRONTAL PASSAGE...HAVE WENT WITH
A DRY FORECAST WEDNESDAY THROUGH THURSDAY NIGHT. THIS IS EVEN WELL
AGREED UPON BY THE GFS WHICH AGAIN IS USUALLY TOO ACTIVE WITH QPF. A
COLD FRONT MAY START TO APPROACH THE AREA FRIDAY INTO FRIDAY NIGHT
FROM THE NORTHWEST...THOUGH WITH IT COMING INTO THE UPPER
RIDGE...WOULD NOT BE SURPRISED IF IT IS SLOWER LIKE THE 30.00Z
ECMWF. STILL...THE FRONT COMING IN WARRANTS SOME LOW CHANCES OF
SHOWERS AND THUNDERSTORMS IN NORTHERN SECTIONS OF THE FORECAST AREA.
REGARDING THE HEAT...850MB TEMPS NO MATTER WHAT SCENARIO PLAYS OUT
LOOK TO STAY AT OR ABOVE 20C. IN FACT...22-24C ARE MORE
LIKELY...WITH THE 24C AIR COMING IN FOR THURSDAY AND FRIDAY. THESE
TWO DAYS NEXT WEEK APPEAR TO BE THE HOTTEST...WITH DEFINITE
POTENTIAL TO APPROACH 100. FOR NOW RAISED HIGHS A COUPLE DEGREES
ABOVE THE CONSENSUS FOR THURSDAY AND FRIDAY. IN SUMMARY...BASICALLY
EVERYDAY IN THE LONG TERM SEES HIGHS IN THE 90S ACROSS THE FORECAST
AREA. WITH DEWPOINTS SUGGESTED TO RANGE FROM THE MID 60S TO LOWER
70S...POTENTIAL EXISTS EACH DAY FOR PORTIONS OF THE FORECAST
AREA TO HAVE HEAT INDICES APPROACH OR EXCEED 100...THE HEAT ADVISORY
THRESHOLD. WILL BE MENTIONING THE LONG PERIOD OF POSSIBLE HEAT IN
THE HWO. NOTE...ALSO RAISED LOW TEMPERATURES A LITTLE ABOVE THE
CONSENSUS. WOULD NOT BE SURPRISED TO HAVE A FEW 80 DEGREE LOWS.
&&
.AVIATION...
1100 PM CDT FRI JUN 29 2012
CONVECTION CONTINUES TO FIRE ALONG A NORTH-SOUTH RUNNING SFC FRONT
ACROSS EASTERN IA/NORTHERN ILL...AIDED BY A PUSH OF LOW LEVEL
MOISTURE AND AN UPPER LEVEL SHORTWAVE. THIS ACTIVITY SHOULD CONTINUE
TO MOVE EAST...AVOIDING THE TAF SITES.
MEANWHILE OVER SD/SOUTHWEST MN...SHRA/TS CONTINUED TO
DEVELOP...PRESSING SOUTHEAST...ASSOCIATED WITH AN UPPER LEVEL
DISTURBANCE. THE LATEST HRRR CAPTURES THIS CONVECTION...AND
CONTINUES ITS SOUTHEAST MOVEMENT...TOWARD THE FRONT AND AWAY FROM
THE RELATIVELY DRIER AIR EAST OF IT. LATEST RAP AND 18Z NAM12 FAVOR
THIS TOO. SO...WILL CONTINUE WITH A DRY FORECAST FOR THE TAFS
OVERNIGHT.
SO...PERIODS OF HIGH CLOUDINESS ARE EXPECTED FOR KRST/KLSE...
RESULTING IN VFR CONDITIONS. WINDS WILL CONTINUE TO SHOW SOME
VARIABILITY IN DIRECTION...ESPECIALLY AT NIGHT...AS THE PRESSURE
GRADIENT REMAINS WEAK.
&&
.CLIMATE...
455 AM CDT SAT JUN 30 2012
A FEW OTHER INTERESTING NOTES REGARDING THE HEAT BEGINNING MONDAY.
850MB STANDARDIZED ANOMALIES ARE FORECAST AT LEAST 2-2.5 ABOVE
NORMAL FROM MONDAY THROUGH FRIDAY...WITH THURSDAY AND FRIDAY
PERHAPS NEAR 3. ALSO...WILL HAVE TO WATCH DEWPOINTS CLOSELY AND
HOW MUCH CONVECTION OCCURS. IF WE DO NOT GET MUCH CONVECTION OVER
THE NEXT FEW DAYS...THE HEAT MAY CAUSE DEWPOINTS TO MIX OUT MORE
DUE TO THE ABNORMALLY DRY TO MODERATE DROUGHT SITUATION IN PLACE.
ALSO...THE DROUGHT COULD RAPIDLY INTENSIFY IF THERE IS A LACK OF
CONVECTION...WHICH THEN WOULD RESULT IN HIGHER TEMPERATURES. ON
THE OTHER HAND...IF MORE CONVECTION OCCURS...THEN TEMPERATURES MAY
BE HELD DOWN SOME BUT HEAT INDICES COULD BE HIGHER.
LA CROSSE RECORD HIGHS NEXT WEEK ARE ALL IN THE 100-105 RANGE.
MOST OF THESE SHOULD BE SAFE. HOWEVER...IT IS LIKELY WE WILL BE NEAR
THESE...ESPECIALLY IF LITTLE IN THE WAY OF CONVECTION OCCURS THE
NEXT FEW DAYS. ROCHESTER IS IN A SIMILAR SITUATION WITH THE RECORD
HIGHS MAINLY BETWEEN 100-105. ONE EXCEPTION TO THIS IS ON THE 4TH
WITH A RECORD HIGH OF 98. THAT STILL SEEMS SAFE AT THIS TIME.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
327 AM CDT SAT JUN 30 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION.....RIECK
CLIMATE...AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
327 AM CDT SAT JUN 30 2012
.SHORT TERM...TODAY THROUGH MONDAY NIGHT
327 AM CDT SAT JUN 30 2012
MAIN FORECAST CONCERNS REMAIN TO BE PRECIPITATION CHANCES
THROUGHOUT AS WELL AS HEAT INDICES ON MONDAY.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED SUBTROPICAL RIDGING STILL DOMINATING MUCH OF THE SOUTHERN
U.S....WITH RIDGING COMING OFF OF THIS EXTENDING FROM THE FOUR
CORNERS REGION INTO ALBERTA AND SASKATCHEWAN. THE FORECAST AREA LIES
IN NORTHWEST FLOW DOWNSTREAM OF THIS RIDGE EXTENSION. WITHIN THE
NORTHWEST FLOW...SHORTWAVES ARE EVIDENT OVER OVER THE FORECAST AREA
AS WELL AS BACK OVER THE DAKOTAS. THE SHORTWAVE OVER THE FORECAST
AREA HAD SOME SHOWERS AND EMBEDDED THUNDERSTORMS WITH IT LAST
EVENING WHEN IT WAS OVER SOUTHWEST MINNESOTA...BUT NOW MOST OF WHAT
IS LEFT IS SOME MID CLOUDS. WITH THE SHORTWAVES BACK OVER THE
DAKOTAS...SOME SHOWERS AN STORMS ARE NOTED OVER CENTRAL NORTH
DAKOTA. OTHER CONVECTION OF INTEREST IS OVER SOUTHERN IOWA...
SITUATED JUST TO THE NORTH OF A STATIONARY FRONTAL BOUNDARY OVER
NORTHERN MISSOURI. THIS CONVECTION IS BEING AIDED BY INCREASE
925-850MB MOISTURE TRANSPORT COMING UP THROUGH EASTERN KANSAS AND
WESTERN MISSOURI. REGARDING MOISTURE...IT IS INTERESTING TO NOTE
THAT PER 00Z SOUNDINGS...THE AMOUNT OF MOISTURE ALONG THE BOUNDARY
IN THE ATMOSPHERE LOOKS TO HAVE DIMINISHED. AT DVN AND OAX...THE
PRECIPITABLE WATER HAS DROPPED TO AROUND 1.6 INCHES OR 150 PERCENT
OF NORMAL...COMPARED TO THE AROUND 2 INCHES OR 200 PERCENT OF NORMAL
SEEN ON THE 29TH AT 00Z. THIS MIGHT BE A RESULT OF THE VARIOUS
ROUNDS OF CONVECTION THAT HAVE ROLLED THROUGH OVER THE PAST 24
HOURS. PRECIPITABLE WATER HAS COME UP TO NEAR 1 INCH AT MPX AND
ABR...BUT THE SOUNDINGS REMAIN FAIRLY DRY...THUS THE CLEAR SKIES AT
BOTH LOCATIONS.
TODAY AND TONIGHT...FORECAST AREA LOOKS TO REMAIN IN THE NORTHWEST
FLOW ALOFT...THOUGH THE FLOW DOES BACK SLIGHTLY IN RESPONSE TO
RIDGING OVER THE NORTHERN ROCKIES PUSHING EAST. THE UPPER LEVEL FLOW
WILL ALLOW THE SHORTWAVES OVER THE DAKOTAS TO PASS ACROSS THE AREA
BETWEEN 18-03Z. NOT THAT THRILLED ABOUT THE PRECIPITATION CHANCES
WITH THESE SHORTWAVES...PRIMARILY BECAUSE THE MAIN INSTABILITY AND
MOISTURE REMAIN STUCK TO THE SOUTH ACROSS SOUTHERN IOWA CLOSER TO
THE STATIONARY FRONTAL BOUNDARY. IN ADDITION...PRETTY MUCH ALL
GUIDANCE HAS TODAY AND TONIGHT DRY...INCLUDING SURPRISINGLY THE GFS
WHICH HAS BEEN TOO ACTIVE WITH PRECIPITATION. 00Z HIRES ARW RUN HAS
A GOOD HANDLE ON THE CONVECTION OVER NORTH DAKOTA AND HAS IT DIE
BEFORE IT REACHES HERE...WHICH SEEMS REASONABLE SINCE IT IS GOING
INTO A STABLE ENVIRONMENT. THEREFORE...HAVE PULLED PRECIPITATION
CHANCES FOR TODAY AND TONIGHT. SOUNDINGS TOO LOOK FAIRLY DRY AND
CAPPED AROUND 800MB. WE SHOULD SEE A LOT MORE SUNSHINE TODAY WITH
NOT AS MUCH CONVECTIVE BLOW-OFF. SOME MID CLOUDS MAY COME IN LATE
WITH THE APPROACH OF THE SHORTWAVES...BUT NOT ENOUGH TO HAMPER
HEATING. 850MB TEMPS OF 16C NORTH TO 20C SOUTH SUPPORT HIGHS IN THE
MID 80S TO LOWER 90S. MOST OF TONIGHT LOOKS MOSTLY CLEAR...THOUGH
SOME MID CLOUDS MAY COME INTO WESTERN PORTIONS OF THE FORECAST AREA
AFTER MIDNIGHT. LOWS SHOULD GENERALLY BE IN THE 60S...THOUGH THE
TYPICAL COOL SPOTS OF WISCONSIN MAY BE ABLE TO DIP INTO THE UPPER
50S.
SUNDAY AND SUNDAY NIGHT...THE UPPER RIDGING OVER THE NORTHERN
ROCKIES LOOKS TO GET A BETTER PUSH EASTWARD DURING THIS PERIOD...DUE
TO TROUGHING CURRENTLY OFF THE WEST COAST LIFTING INTO THE NORTHERN
ROCKIES. THE RESPONSE TO THE EASTWARD MOVEMENT TO THE UPPER RIDGE IS
TO INCREASE LOW LEVEL SOUTHERLY FLOW OVER THE PLAINS...WHICH MEANS
THAT STATIONARY FRONT IS GOING TO LIFT NORTH AS A WARM FRONT. AT
LEAST FOR SUNDAY...THE FRONT SHOULD STAY SOUTH OF THE AREA...KEEPING
THE BULK OF THE PRECIPITATION ON IT TO THE SOUTH. DID KEEP SOME 20
PERCENT CHANCES IN SOUTH OF I-90 FOR SUNDAY AS A BUFFER. LOOKS LIKE
WE WILL STILL HAVE TO CONTEND WITH MID CLOUDS...ESPECIALLY IN THE
MORNING WHEN THE BEST ISENTROPIC LIFT IS OCCURRING ON THE 315K
SURFACE. BETTER SURGE NORTHWARD OF THE WARM FRONT LOOKS TO OCCUR
SUNDAY NIGHT. HOW FAST VARIES FROM MODEL TO MODEL...WITH THE 30.00Z
NAM HAVING IT REACH I-94 COMPARED TO ONLY NORTHEAST IOWA AT MOST FOR
THE 30.00Z GFS/ECMWF. THIS IS CRITICAL TO SOME DEGREE SINCE
INCREASING MOISTURE TRANSPORT ABOVE THE FRONT COULD RESULT IN
ELEVATED CONVECTION. CONFIDENCE IN CONVECTION IS LOW SINCE IT IS
HARD AT THIS POINT TO FIND ANY FOCUSED AREAS OF MOISTURE TRANSPORT.
HOWEVER... SYNOPTICALLY THE SCENARIO CAN FAVOR CONVECTION. FOR NOW
STAYED WITH THE PREVIOUS FORECAST OF 20 PERCENT CHANCES. WITH WARMER
AIR MOVING IN...NOTED BY 850MB TEMPS CLIMBING TO AROUND 20C BY 18Z
SUNDAY...ANTICIPATE HIGHS A FEW DEGREES WARMER THAN TODAY. SIMILAR
SITUATION WITH LOWS...GIVEN WARMER AND MORE HUMID AIR WILL RESULT IN
WARMER TEMPERATURES AT NIGHT.
MONDAY AND MONDAY NIGHT...UPPER RIDGING LOOKS TO CONTINUE TO BUILD
NORTHEASTWARD TOWARDS THE FORECAST AREA...KEEPING A SOUTHWEST LOW
LEVEL WARM ADVECTION PATTERN IN PLACE. DIFFERENCES STILL REMAIN ON
THE NORTHWARD SPEED OF THE WARM FRONT. HOWEVER...BY 00Z TUESDAY MOST
OF THE MODELS COME INTO AGREEMENT OF A POSITION AT LEAST NEAR I-94.
INSTABILITY ALONG THE FRONT COMBINED WITH THE WEAK FRONTAL
CONVERGENCE COULD PROVE ENOUGH TO TRIGGER CONVECTION. THERE ARE
INDICATIONS OF A WEAK SHORTWAVE MOVING THROUGH TOO. IF THIS DOES NOT
COME THROUGH...700MB TEMPS ARE PROGGED TO INCREASE THROUGH THE
DAY...TOWARDS 11C OR SO BY THE END OF THE DAY...WHICH COULD
EFFECTIVELY CAP CONVECTION ON THE FRONT. GIVEN THIS UNCERTAINTY AND
POTENTIAL FOR CAPPING...STILL ONLY KEPT PRECIPITATION CHANCES IN THE
30-40 RANGE FOR MONDAY. CHANCES SHIFT NORTHEAST AND LOWER TO 20-30
WITH THE WARM FRONT LIFTING PERHAPS ALL THE WAY THROUGH THE FORECAST
AREA. 850MB TEMPS WARM TO 20-23C ON MONDAY WHICH WOULD SUPPORT HIGHS
IN THE UPPER 80S TO MID 90S. IF THE 30.00Z NAM/UKMET ARE RIGHT WITH
THE WARM AIR COMING IN...SUGGESTING 24-26C 850MB TEMPS POSSIBLE...
HIGHS COULD BE WARMER YET. ONE CONCERN WITH THE FRONT IN THE AREA IS
THE HIGHER DEWPOINTS AROUND 70 ACCOMPANYING IT. THESE DEWPOINTS
COMBINED WITH THE FORECAST HIGH TEMPERATURES MAY RESULT IN HEAT
INDICES AROUND 100 IN VALLEY AREAS AND IN NORTHEAST IOWA. THUS...A
HEAT ADVISORY MAY BE NEEDED. WARM NIGHT LIKELY MONDAY NIGHT BEING
MOSTLY SOUTH OF THE FRONT. 70S ARE LIKELY FOR LOWS.
IF CONVECTION OCCURS SUNDAY THROUGH MONDAY NIGHT...0-6 KM SHEAR
IS MOSTLY BELOW 30 KTS. THEREFORE...NOT OVERLY CONCERNED ABOUT
SEVERE WEATHER AT THIS POINT. STORMS COULD PRODUCE LOCALLY HEAVY
RAIN GIVEN DEEP WARM CLOUD DEPTHS...BUT AGAIN CONFIDENCE OVERALL
IS LOW ON CONVECTION IN THE FIRST PLACE.
.LONG TERM...TUESDAY THROUGH FRIDAY NIGHT
327 AM CDT SAT JUN 30 2012
BUILDING HEAT AND SMALL CHANCES FOR PRECIPITATION REMAIN MAIN
CONCERN FOR THE LONG TERM PERIOD.
30.00Z ECMWF/CANADIAN/GFS/GFS ENSEMBLES ALL SHOW THE CURRENT
SUBTROPICAL RIDGING OVER THE SOUTHERN U.S. EXPANDING ACROSS MUCH OF
THE U.S. DURING THIS PERIOD. HOWEVER...THERE ARE DEFINITELY SOME
ISSUES TO DEAL WITH. THE FIRST IS LATE TUESDAY INTO TUESDAY NIGHT
WHERE THE 30.00Z GFS...GFS ENSEMBLES AND CANADIAN SHOW A COLD FRONT
DROPPING SOUTHEAST THROUGH THE AREA...ASSOCIATED WITH A SHORTWAVE
CROSSING THE WESTERN GREAT LAKES. THE ECMWF HAS YET TO SHOW THIS
COLD FRONT COMING THROUGH. GIVEN THE MODEL SPLIT...FOR NOW KEPT THE
LOW PRECIPITATION CHANCES GOING. THE FRONT SHOULD NOT DROP TOO FAR
SOUTH OF THE AREA GIVEN THE BUILDING RIDGING. IN FACT...BY MID-DAY
THURSDAY...THE GFS...MAJORITY OF GFS ENSEMBLES AND ECMWF ALL SUGGEST
THE WARM FRONT WILL BE NORTH OF THE AREA. THIS WILL USHER IN THE
HEAT SEEN TO OUR SOUTH. LOOKS LIKE THE AIRMASS SHOULD BE CAPPED
ENOUGH SUCH THAT EVEN WITH THE WARM FRONTAL PASSAGE...HAVE WENT WITH
A DRY FORECAST WEDNESDAY THROUGH THURSDAY NIGHT. THIS IS EVEN WELL
AGREED UPON BY THE GFS WHICH AGAIN IS USUALLY TOO ACTIVE WITH QPF. A
COLD FRONT MAY START TO APPROACH THE AREA FRIDAY INTO FRIDAY NIGHT
FROM THE NORTHWEST...THOUGH WITH IT COMING INTO THE UPPER
RIDGE...WOULD NOT BE SURPRISED IF IT IS SLOWER LIKE THE 30.00Z
ECMWF. STILL...THE FRONT COMING IN WARRANTS SOME LOW CHANCES OF
SHOWERS AND THUNDERSTORMS IN NORTHERN SECTIONS OF THE FORECAST AREA.
REGARDING THE HEAT...850MB TEMPS NO MATTER WHAT SCENARIO PLAYS OUT
LOOK TO STAY AT OR ABOVE 20C. IN FACT...22-24C ARE MORE
LIKELY...WITH THE 24C AIR COMING IN FOR THURSDAY AND FRIDAY. THESE
TWO DAYS NEXT WEEK APPEAR TO BE THE HOTTEST...WITH DEFINITE
POTENTIAL TO APPROACH 100. FOR NOW RAISED HIGHS A COUPLE DEGREES
ABOVE THE CONSENSUS FOR THURSDAY AND FRIDAY. IN SUMMARY...BASICALLY
EVERYDAY IN THE LONG TERM SEES HIGHS IN THE 90S ACROSS THE FORECAST
AREA. WITH DEWPOINTS SUGGESTED TO RANGE FROM THE MID 60S TO LOWER
70S...POTENTIAL EXISTS EACH DAY FOR PORTIONS OF THE FORECAST
AREA TO HAVE HEAT INDICES APPROACH OR EXCEED 100...THE HEAT ADVISORY
THRESHOLD. WILL BE MENTIONING THE LONG PERIOD OF POSSIBLE HEAT IN
THE HWO. NOTE...ALSO RAISED LOW TEMPERATURES A LITTLE ABOVE THE
CONSENSUS. WOULD NOT BE SURPRISED TO HAVE A FEW 80 DEGREE LOWS.
&&
.AVIATION...
1100 PM CDT FRI JUN 29 2012
CONVECTION CONTINUES TO FIRE ALONG A NORTH-SOUTH RUNNING SFC FRONT
ACROSS EASTERN IA/NORTHERN ILL...AIDED BY A PUSH OF LOW LEVEL
MOISTURE AND AN UPPER LEVEL SHORTWAVE. THIS ACTIVITY SHOULD CONTINUE
TO MOVE EAST...AVOIDING THE TAF SITES.
MEANWHILE OVER SD/SOUTHWEST MN...SHRA/TS CONTINUED TO
DEVELOP...PRESSING SOUTHEAST...ASSOCIATED WITH AN UPPER LEVEL
DISTURBANCE. THE LATEST HRRR CAPTURES THIS CONVECTION...AND
CONTINUES ITS SOUTHEAST MOVEMENT...TOWARD THE FRONT AND AWAY FROM
THE RELATIVELY DRIER AIR EAST OF IT. LATEST RAP AND 18Z NAM12 FAVOR
THIS TOO. SO...WILL CONTINUE WITH A DRY FORECAST FOR THE TAFS
OVERNIGHT.
SO...PERIODS OF HIGH CLOUDINESS ARE EXPECTED FOR KRST/KLSE...
RESULTING IN VFR CONDITIONS. WINDS WILL CONTINUE TO SHOW SOME
VARIABILITY IN DIRECTION...ESPECIALLY AT NIGHT...AS THE PRESSURE
GRADIENT REMAINS WEAK.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
327 AM CDT SAT JUN 30 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1109 AM EDT SAT JUN 30 2012
.SYNOPSIS...
A WEAK COLD FRONT SETTLES JUST TO THE SOUTH TODAY...AND REMAINS
NEARLY STATIONARY JUST TO THE SOUTH THIS WEEKEND. HIGH PRESSURE
BUILDS TO THE NORTH MONDAY AND TUESDAY. A WARM FRONT MOVES THROUGH
WEDNESDAY FOLLOWED BY A COLD FRONT LATE WEDNESDAY OR EARLY THURSDAY.
HIGH PRESSURE BUILDS TO END THE UPCOMING WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPPER LEVEL PATTERN OF THE RIDGE TO THE SOUTH AND A TROUGH OVER SE
CANADA WILL BE IN PLACE TODAY. A SURFACE FRONTAL BOUNDARY IS
CURRENTLY TO THE SOUTH OF THE REGION...ALLOWING FOR MORE OF A
WESTERLY FLOW AND THEREFORE DRIER AIR TO SETTLE INTO THE AREA.
WARMER AIR FROM VERTICAL MIXING UP TO AROUND 800 MB EXPECTED TO
RESULT IN ANOTHER HOT BUT SLIGHTLY DRIER DAY WITH HIGHS WELL INTO
THE 90S FOR MANY LOCATIONS. NOT MUCH CHANGE WITH MAX TEMPS IN
PREVIOUS FORECAST...JUST SLIGHT ADJUSTMENTS UP AND DOWN A DEGREE
IN A FEW SPOTS. DEWPOINTS WERE ADJUSTED SLIGHTLY DOWN NEXT FEW
HOURS BUT STILL EXPECTING HEAT INDICES IN THE MID TO UPPER 90S SO
WILL KEEP HEAT ADVISORY FOR NEW YORK CITY FOR THIS AFTERNOON
ESPECIALLY FOR SOUTHERN LOCATIONS ONCE THE SEA BREEZE STARTS TO
MOVE IN AND BRINGS IN SLIGHTLY HIGHER DEWPOINTS.
WITH AN EMBEDDED SHORTWAVE WITHIN THE QUASI-ZONAL FLOW ALOFT MOVING
NEAR THE REGION BY THIS EVENING AS CONVEYED BY SOME PVA...THIS
WILL PROBABLY LIFT THE FRONTAL BOUNDARY BACK CLOSER TO THE AREA.
INCREASED CLOUDS THIS AFTERNOON AND KEPT THE SLIGHT CHANCE FOR
SHOWERS AND THUNDERSTORMS FOR LATE AFTERNOON INTO THE EARLY
EVENING FOR WESTERN LOCATIONS DESPITE THE LACK OF QPF SIGNAL FROM
THE NAM AND GFS WITH THEIR LAST RUNS. HRRR IS STARTING TO PICK UP
ON THIS CONVECTION TOWARDS THE LATE AFTERNOON. INSTABILITY IS
ALREADY STARTING TO BUILD...WITH VALUES OF CAPE VALUES BETWEEN 200
AND 700 J/KG FOR WESTERN AREAS OF THE FORECAST REGION THIS
MORNING. THIS WILL PROBABLY INCREASE TO AROUND 1000 J/KG AT LEAST
FOR SOME LOCATIONS THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
A GENERAL TROUGH OVER THE NORTHEAST REMAINS IN PLACE THIS TIME
FRAME. AT THE SFC...WEAK FRONTAL BOUNDARY SHOULD REMAIN JUST SOUTH.
IN SPITE OF THE SLIGHTLY LOWER HEIGHTS...STILL QUITE WARM TO HOT
CONDITIONS EXPECTED.
FOR TONIGHT...POSSIBLE MCS PASSES EITHER JUST SOUTH...OR HAS A
BIGGER IMPACT ON THE AREA. PLEASE SEE NEAR TERM SECTION FOR MORE ON
THIS POSSIBILITY...AND THE QUESTIONS THAT REMAIN.
OTHERWISE...FORECAST REMAINS DRY...WITH POSSIBLE CONVECTION DURING
THE DAY SUNDAY AGAIN. HOWEVER...COVERAGE SHOULD BE LOW...AND POPS
WILL FOLLOW SUIT.
AGAIN...WARMER THAN NORMAL TEMPS THIS TIME FRAME...WITH 60S TO 70S
AT NIGHT...AND 80S TO LOWER/MID 90S SUNDAY. HEAT ADVISORIES REMAIN
UP FOR NYC.
THERE IS A MODERATE RISK OF RIP CURRENTS AT THE OCEAN BEACHES
TODAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
SUNDAY NIGHT THROUGH TUESDAY...LOOK FOR GRADUAL COOLING AND
DRYING WITH THE LOWEST TEMPS AND HUMIDITIES OCCURRING DURING TUE. AN
ISOLATED SHOWER OR TSTM CANNOT BE RULED OUT MONDAY AFTERNOON BASED
ON SFC AND LOW LVL BASED INSTABILITY.
TUESDAY NIGHT THROUGH EARLY THURSDAY...THIS APPEARS TO BE AN
UNSETTLED PERIOD.
A WARM FRONT IS FORECAST TO DEVELOP AND MOVE NORTHEAST TOWARD THE
REGION AS A COLD FRONT TRAILING FROM A LOW PRESSURE SYSTEM MOVING
ACROSS SOUTHEAST CANADA MOVES ACROSS THE REGION.
WEST AND NW WIND FLOW ALOFT CONTINUES AS A HIGH AMPLITUDE RIDGE
MOVES EAST TOWARD THE WESTERN GREAT LAKES. THIS WILL SET THE STAGE
FOR A SERIES OF MCS MOVING SE DOWN THE RIDGE. IN A MOIST MARITIME
TROPICAL AIR MASS...HEAVY SHOWERS AND TSTMS ARE POSSIBLE. BECAUSE
OF HIGH FCST UNCERTAINTY...ONLY 20 PCT POP IS IN THE FCST FOR NOW.
STAY TUNED.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
VFR THROUGH THE TAF PERIOD.
WEST TO NORTHWEST FLOW...TO THE LEFT OF 310...EXPECTED INTO THE
EARLY AFTERNOON. DO NOT HAVE HIGH CONFIDENCE THAT SEA BREEZES WILL
DEVELOP AND BRING WINDS AROUND TO THE SOUTH AT KJFK AND KLGA AS
DEEP NORTHWEST FLOW AT 25 TO 30 KT WILL LIKELY PERSIST THROUGH
THE AFTERNOON. IF WINDS DO COME AROUND WOULD BE LATE IN THE
AFTERNOON.
TONIGHT...WINDS BECOME LIGHT AND VARIABLE ONCE AGAIN. THERE WILL BE
A CHANCE OF SHOWERS AND THUNDERSTORMS WITH ANOTHER MCS MOVING OUT
OF THE GREAT LAKES REGION. CONFIDENCE OF ANY STORMS ARE LOW AT
THIS TIME AND WILL NOT INCLUDE IN THE TAFS.
AMENDMENTS MAY BE NEEDED TODAY FOR TIMING OF WIND SHIFTS.
OUTLOOK FOR 12Z SUNDAY THROUGH WEDNESDAY...
.SUN-TUE...VFR.
.WEDNESDAY...TSTMS POSSIBLE.
&&
.MARINE...
WINDS AND SEAS ARE GENERALLY EXPECTED TO REMAIN BELOW SCA LEVELS
THROUGH SUNDAY...ALTHOUGH SWELL FROM WHAT IS LEFTOVER FROM DEBBY
WILL LIKELY MAINTAIN OCEAN SEAS IN THE 3 TO 4 RANGE. COULD SEE
BRIEF 5 FOOTERS TODAY OVER THE OCEAN ZONES.
NEXT WEEK...WINDS AND SEAS ARE FORECAST TO REMAIN BELOW SMALL CRAFT
ADVISORY LIMITS OF 25 KT AND 5 FT.
&&
.HYDROLOGY...
DRY THIS MORNING. THERE IS A LOW PROBABILITY FOR DOWNPOURS
CAPABLE OF CAUSING MINOR URBAN/POOR DRAINAGE FLOODING LATE TODAY
AND TONIGHT. A FLASH FLOOD THREAT COULD UNFOLD IF AN MCS WORKS
INTO THE REGION...BUT PROBABILITY OF OCCURRENCE AT THIS TIME IS
LOW.
&&
.CLIMATE...
HERE ARE THE RECORD HIGHS AND FORECAST TEMPS FOR SATURDAY JUNE 30:
..LOCATION........FORECAST HIGH.......RECORD HIGH.......YEAR....
CENTRAL PARK NY.........93.................99...........1964....
LAGUARDIA NY............95.................97...........1964....
KENNEDY NY..............94.................99...........1964....
NEWARK NJ...............99.................99...........1964....
ISLIP NY................92.................89...........2001....
BRIDGEPORT CT...........92.................94...........1959....
HERE ARE THE RECORD HIGHS AND FORECAST TEMPS FOR SUNDAY JULY 1:
..LOCATION........FORECAST HIGH.......RECORD HIGH.......YEAR....
CENTRAL PARK NY.........94................100...........1901....
LAGUARDIA NY............96.................97...........1964....
KENNEDY NY..............93................102...........1963....
NEWARK NJ...............96................100...........1963....
ISLIP NY................91.................87...........2001....
BRIDGEPORT CT...........90.................95...........1963....
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR NYZ072>075-176-
178.
HEAT ADVISORY FROM NOON TO 7 PM EDT SUNDAY FOR NYZ072>075-176-
178.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...PW
NEAR TERM...JM
SHORT TERM...PW
LONG TERM...PW
AVIATION...MET
MARINE...BC
HYDROLOGY...PW
CLIMATE...
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1008 AM CDT SAT JUN 30 2012
.DISCUSSION...
ISSUED 1008 AM CDT SAT JUN 30 2012
ISSUED A QUICK ZONE UPDATE THIS MORNING TO EXTEND LOW CHANCE POPS
FURTHER SOUTH. OUTFLOW BOUNDARY FROM OVERNIGHT CONVECTION ACROSS
NORTHERN ILLINOIS HAS SETTLED INTO THE KILX CWA...WITH 15Z
SATELLITE/RADAR DATA SHOWING ITS CURRENT LOCATION FROM JUST NORTH
OF PARIS TO NEAR TAYLORVILLE. A FEW SHOWERS ARE BEGINNING TO
DEVELOP ALONG THE BOUNDARY...SO FELT POPS WERE WARRANTED TO NEAR
THE I-70 CORRIDOR. FURTHER SOUTH...WILL MAINTAIN A HOT/DRY
FORECAST FOR THE SOUTHEAST CWA. BEST RAIN CHANCES TODAY WILL ONCE
AGAIN BE CONFINED TO LOCATIONS ALONG/NORTH OF I-74...IN CLOSER
PROXIMITY TO STATIONARY FRONTAL BOUNDARY. HRRR MODEL GENERALLY
SHOWS CURRENT CLUSTER OF SHOWERS/STORMS N/NW OF THE PEORIA AREA
TRACKING E/SE INTO INDIANA BY THIS AFTERNOON. WILL CARRY 40 POPS
ACROSS THE N/NE CWA FROM PEORIA TO CHAMPAIGN-URBANA ACCORDINGLY.
HIGH TEMPS STILL LOOK TO BE ON TARGET...WITH READINGS IN THE LOWER
90S FAR NORTH...TO OVER 105 DEGREES SOUTH OF I-70.
BARNES
&&
.AVIATION...
ISSUED 654 AM CDT SAT JUN 30 2012
A PREDOMINANTLY QUIET...BUT TRICKY...AVIATION WEATHER FORECAST IS
EXPECTED THROUGH THE 12Z TAF VALID TIME. SEVERAL ROUNDS OF STORMS
HAVE PUSHED A FRONTAL BOUNDARY THAT HAD BEEN OVER NORTHERN
ILLINOIS A BIT FURTHER SOUTH INTO CENTRAL ILLINOIS. THIS SHOULD
INCREASE THE RISK OF PRECIPITATION IMPACTING AT LEAST
KPIA/KBMI/KCMI AS IMPULSES RIDE ALONG THE FRONT...THOUGH COVERAGE
SHOULD STILL BE PRETTY LOW. WITH THIS IN MIND...HAVE ONLY CARRIED
VCSH/VCTS MENTION.
BAK
&&
.PREV DISCUSSION...
ISSUED 305 AM CDT SAT JUN 30 2012
THUNDERSTORM ACTIVITY HAS BEEN PRESENT ACROSS THE NORTHERN CWA
THE LAST FEW HOURS...WITH SOME DEVELOPMENT ALSO OCCURRING NEAR
CHAMPAIGN AND DANVILLE AROUND 130 AM ON ONE OF THE OUTFLOWS FROM
EARLIER CONVECTION. THE SOUTHERNMOST OUTFLOW WAS GENERALLY JUST
NORTH OF A PARIS TO SHELBYVILLE LINE...WITH WINDS BEHIND IT
SHIFTING TO THE NORTHEAST. SOME INTERESTING TEMPERATURE ANTICS
AHEAD OF THIS BOUNDARY...WITH FLORA AND OLNEY BOTH SEEING TEMPS
JUMP 5-7 DEGREES BETWEEN 1 AND 2 AM...AND EFFINGHAM GOING UP 5
DEGREES SHORTLY AFTER MIDNIGHT.
SHORT TERM...TODAY THROUGH MONDAY...
MAIN CONCERN DURING THIS PERIOD WILL BE WITH CONVECTIVE CHANCES
AND TEMPERATURES...AS THE FORMER WILL DIRECTLY IMPACT THE LATTER.
SHORTWAVE CURRENTLY EXTENDING FROM THE WESTERN GREAT LAKES INTO
IOWA WILL SWING THROUGH THE REGION TODAY. SURFACE BOUNDARY/FRONT
IS PROGGED BY THE MODELS TO SLIP SOUTHWARD INTO THE CWA THIS
EVENING. EXTENT OF CONVECTIVE REDEVELOPMENT WILL HINGE ON HOW FAST
THE CURRENT STORMS DIMINISH...ALLOWING THE ATMOSPHERE TO RECHARGE.
WILL SEE DEW POINTS POOLING JUST SOUTH OF THE BOUNDARY...SO CAPES
ACROSS THE NORTHERN CWA WILL LIKELY EXCEED 3000 J/KG BY MID-
AFTERNOON. WILL KEEP MOST OF THE RAIN CHANCES NORTH OF A
BEARDSTOWN TO DANVILLE LINE TODAY...WITH SOME SLIGHT CHANCES ALONG
THE I-72 CORRIDOR.
EVENING MODELS SHOWING A SERIES OF MCS POTENTIAL TONIGHT AND
SUNDAY...WITH THE NORTH HALF OF THE CWA THE PRIMARY RECIPIENTS.
TIMING TONIGHT IS NOT AS CONSISTENT AMONG THE MODELS...SO WILL
NOT TRY TO BREAK IT DOWN WITH EVENING VS OVERNIGHT WORDING. SUNDAY
AFTERNOON IS IN BETTER AGREEMENT AS CAPES AGAIN REACH 3000-4000
J/KG BY MID-AFTERNOON. SPC CONVECTIVE OUTLOOKS FOR TODAY AND
SUNDAY BOTH HAVE SLIGHT RISKS FOR THE NORTHERN HALF OF THE CWA. BY
MONDAY... UPPER RIDGING ACROSS THE PLAINS WILL BE BUILDING TOWARD
THE MISSISSIPPI VALLEY...SHUNTING THE MCS ACTIVITY MORE TO OUR
EAST.
TEMPERATURE-WISE...THINK THE VARIOUS BOUNDARIES AND CLOUDS WILL
KEEP THE NORTHERN CWA SLIGHTLY COOLER THE NEXT FEW DAYS...WITH
MID 90S FOR HIGHS...AS OPPOSED TO THE 100+ ACROSS THE CENTRAL AND
SOUTH. AS A RESULT...WILL DOWNGRADE THE EXCESSIVE HEAT WARNING
NORTH OF A GALESBURG TO BLOOMINGTON LINE...REPLACING IT WITH A
HEAT ADVISORY. WILL KEEP THE WARNING GOING FURTHER SOUTH. HAVE
GONE WITH TEMPS 105 OR HIGHER ACROSS THE SOUTHEAST TODAY...WHERE
MORE MIXING WILL TAKE PLACE...AND 100-105 FOR SUNDAY AND MONDAY.
THE HEAT HEADLINES MAY NEED TO BE EXTENDED IN TIME...BUT QUESTIONS
REGARDING THE OUTFLOWS AND CONVECTION PRECLUDE THIS AT THE MOMENT.
LONG TERM...TUESDAY THROUGH FRIDAY...
UPPER RIDGE CONTINUES TO DOMINATE THE EASTERN HALF OF THE
NATION. 850 MB TEMPERATURES REMAIN IN THE 23-24C RANGE OVER OUR
AREA...WITH MID TO UPPER 90S FOR HIGHS. WILL KEEP DRY WEATHER
THROUGH THE PERIOD.
GEELHART
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
EXCESSIVE HEAT WARNING UNTIL 7 PM CDT SUNDAY FOR ILZ036-040>057-
061>063-066>068-071>073.
HEAT ADVISORY UNTIL 7 PM CDT SUNDAY FOR ILZ027>031-037-038.
&&
$$
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1033 AM EDT SAT JUN 30 2012
.SYNOPSIS...
A SERIES OF DISTURBANCES WILL CROSS THE REGION THROUGH THE
WEEKEND KEEPING UNSETTLED CONDITIONS ACROSS THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE 1020 AM...THE MAIN CONCERN ONCE AGAIN TODAY WILL BE THE
POSSIBILITY OF MORE STRONG TO SEVERE STORMS THIS AFTERNOON AND
EVENING. SHORT WAVE TROF MOVING SOUTHEAST FROM QUEBEC AND AN
ASSOCIATED COLD FRONT WILL APPROACH THE REGION THIS AFTERNOON
AND THEN CROSS THE REGION TONIGHT. LATEST HRRR AND RAPID
REFRESH ARE INDICATING CONVECTION WILL FIRE UP ONCE AGAIN LATER
THIS AFTERNOON AND CONTINUE INTO THIS EVENING. CURRENT FORECAST
MENTIONS DAMAGING WINDS AND LARGE HAIL POSSIBLE SO CURRENT
FORECAST LOOKS GOOD. ONLY ADJUSTMENT WAS TO RAISE HIGH TEMPERATURES
TODAY SINCE TEMPERATURES ARE RISING A LITTLE FASTER THAT EXPECTED.
PREVIOUS DISCUSSION...
THE MAIN FORECAST CONCERN TODAY IS SEVERE WEATHER POTENTIAL. A
PRE-FRONTAL TROF WILL CROSS THE REGION THIS AFTERNOON...IN ADVANCE
OF A COLD FRONT WHICH WILL BEGIN TO CROSS THE REGION TONIGHT. A
DISTURBANCE ROTATING AROUND THE UPPER TROF TO THE NORTH WILL ALSO
CROSS THE REGION THIS AFTERNOON. THE TIMING OF THE SURFACE
TROF/UPPER DISTURBANCE WILL CORRESPOND WITH MAXIMUM DIURNAL
HEATING. DEWPOINTS OF AROUND 60 TO THE LOWER 60S WILL PROVIDE LOW
LEVEL MOISTURE. BASED ON FORECAST SOUNDINGS...MID LEVEL
WINDS...STEEP LAPSE RATES...LOW LEVEL MOISTURE...UPPER LEVEL
SUPPORT AND DIURNAL HEATING EXPECT STRONG TO SEVERE THUNDERSTORMS
ARE AGAIN POSSIBLE ACROSS THE REGION THIS AFTERNOON. LARGE
HAIL...DAMAGING WINDS AND HEAVY RAINS ARE POSSIBLE WITH ANY
THUNDERSTORMS. THE BEST THUNDERSTORM CHANCES WILL OCCUR FROM EARLY
AFTERNOON INTO THE EVENING HOURS. SHOWERS/THUNDERSTORMS WILL THEN
DIMINISH TONIGHT WITH THE LOSS OF HEATING AND THE UPPER
DISTURBANCE MOVING EAST...LEAVING PARTLY CLOUDY/MOSTLY CLEAR SKIES
ACROSS THE FORECAST AREA OVERNIGHT. HIGH TEMPERATURES TODAY WILL
RANGE FROM AROUND 80 TO THE LOWER 80S NORTH...TO THE MID 80S
INTERIOR DOWNEAST WITH UPPER 70S TO LOWER 80S ALONG THE DOWNEAST
COAST. OVERNIGHT LOW TEMPERATURES WILL RANGE FROM THE UPPER 50S TO
AROUND 60 ACROSS THE REGION.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY/...
WEAK COLD FRONT IS EXPECTED TO MOVE THROUGH THE REGION AT THE
BEGINNING OF THIS PERIOD WITH SURFACE HIGH PRESSURE BUILDING IN
BEHIND THE FRONT. AN UPPER LEVEL TROUGH MOVES ACROSS THE STATE
TUESDAY RESULTING IN SHOWERS AND SCATTERED THUNDER. WILL BLEND
GFS40..NAM12...SREF AND ECMWF FOR POPS AND WILL INCREASE POPS WITH
PASSAGE OF UPPER TROUGH TUESDAY. HAVE USE GMOS FOR TEMPERATURE AND
DEW POINT. A BLEND OF GMOS AND NAM12 WAS USED FOR WIND. WILL
MENTION SCATTERED THUNDER MONDAY AFTERNOON INTO EARLY EVENING.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
WEAK WEATHER PATTERN AT THE SURFACE IS EXPECTED TO PERSIST
THROUGH THIS PERIOD. ALOFT EXPECT SHORT WAVES TO PERIODICALLY MOVE
ACROSS THE STATE RESULTING IN SHOWERS. HAVE USED THE GMOS TO
INITIALIZE ALL GRIDS. WILL ADJUST POPS AND SKY COVER. WILL MENTION
SCATTERED THUNDER WEDNESDAY AFTERNOON INTO EARLY EVENING.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
NEAR TERM: IFR/LIFR CONDITIONS ARE POSSIBLE WITH PATCHY FOG EARLY
THIS MORNING. OCCASIONAL MVFR/IFR CONDITIONS ARE THEN POSSIBLE
WITH ANY SHOWERS OR THUNDERSTORMS TODAY THROUGH EARLY TONIGHT.
SHORT TERM: VFR CONDITIONS SUNDAY THROUGH EARLY MONDAY THEN
MVFR/IFR CONDITIONS MONDAY AFTERNOON INTO EVENING. VFR CONDITIONS
EXPECTED TUESDAY. MVFR CONDITIONS EXPECTED WEDNESDAY.
&&
.MARINE...
NEAR TERM: WINDS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY
LEVELS TODAY THROUGH TONIGHT. SEAS COULD APPROACH MARGINAL SMALL
CRAFT ADVISORY LEVELS LATER TODAY THROUGH TONIGHT. VISIBILITIES
COULD BE REDUCED IN PATCHY FOG THIS MORNING...WITH REDUCED
VISIBILITIES IN ANY SHOWERS OR THUNDERSTORMS THIS AFTERNOON
THROUGH EARLY TONIGHT.
SHORT TERM: HAVE USED A BLEND OF THE NAM12 AND GFS40 FOR WIND
GRIDS UNTIL 1200Z MONDAY THEN TRANSITION TO THE GMOS WINDS. FOR
WAVES: EXPECT LIGHT WINDS TO PERSIST IN LOCAL WATERS THROUGH
ENTIRE PERIOD. EXPECT LONGER PERIOD WAVES TO DOMINATE SUNDAY AND
MONDAY THEN SUBSIDING BELOW 2 FEET TUESDAY. HAVE USED THE NAM/SWAN
UNTIL 1200Z MONDAY THEN TRANSITION TO WNA/4. HAVE ADJUSTED SOME
WAVES LOWER AFTER TUESDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...DUDA/NORCROSS
SHORT TERM...MIGNONE
LONG TERM...MIGNONE
AVIATION...DUDA/NORCROSS
MARINE...DUDA/NORCROSS/MIGNONE
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1004 AM CDT SAT JUN 30 2012
.UPDATE...
ISSUED AT 954 AM CDT SAT JUN 30 2012
QUICK UPDATE TO ADD POPS ACROSS PORTIONS OF SW IL TO ACCOUNT FOR
ONGOING SHRA. RUC PICKS UP ON THIS AREA OF PRECIP THIS MORNING
WITH THE FORCING WEAKENING OVER THE NEXT COUPLE OF HOURS. WITH
ANOTHER OUTFLOW MOVING SWD FROM CONVECTION FURTHER N...AM NOT
CONFIDENT THIS CONVECTION WILL DIMINISH AS QUICKLY AS THE RUC
SUGGESTS. HOWEVER...IT IS UNLIKELY THAT ANY SHRA WILL DEVELOP
FURTHER W AND THE ONGOING SHRA WILL LIKELY CONTINUE TO MOVE EWD
AND EVENTUALLY MOVE OUT OF THE CWA. HAVE THEREFORE ONLY KEPT THESE
POPS FOR THE MORNING HOURS.
REGARDLESS OF THIS PRECIP...BELIEVE TEMPS ARE STILL ON TRACK AS
THE PRECIP WILL LIKELY ONLY HELP RAISE DEWPOINTS AND SLIGHTLY
LOWER TEMPS.
TILLY
&&
.SHORT TERM...
ISSUED AT 329 AM CDT SAT JUN 30 2012 (TODAY)
AN OUTFLOW BOUNDARY FROM ORGANIZED CONVECTION ACROSS ERN IA AND NRN
IL HAS DROPPED SWD TO JUST S OF PPQ EARLY THIS MRNG. THERE WERE A
FEW SMALL SHOWERS ALONG THIS BOUNDARY ACROSS W CNTRL IL BUT THESE
HAVE SINCE DISSIPATED. WILL INCLUDE LOW CHANCE OR SLIGHT CHANCE
POPS TODAY ACROSS NERN MO AND W CNTRL IL WITH ADDITIONAL CONVECTION
POSSIBLE ALONG THESE OUTFLOW BOUNDARIES AND AS A WEAK SYNOPTIC FRONT
DROPS SWD INTO EXTREME NRN MO AND CNTRL IL AS A WEAK SFC RIDGE
BUILDS SEWD THROUGH THE NRN PLAINS AND INTO THE GREAT LAKES REGION
THIS AFTN. THE ATMOSPHERE SHOULD BE TOO CAPPED FOR ANY CONVECTION S
OF THIS AREA TODAY. BECAUSE OF SOME MID-HIGH LEVEL CLOUDINESS HIGH
TEMPERATURES TODAY WILL LIKELY BE SLIGHTLY COOLER THAN FRIDAY
ACROSS PORTIONS OF NERN MO AND W CNTRL IL. FURTHER S LITTLE CLOUD
COVER IS EXPECTED WITH SIMILAR MAX TEMPERATURES EXPECTED TODAY
COMPARED TO YESTERDAY...LIKELY RANGING FROM 100 TO 105 DEGREES. AN
EXCESSIVE HEAT WARNING CONTINUES FOR THE ST LOUIS METRO AREA AND
PORTIONS OF SERN MO AND SWRN IL WITH A HEAT ADVISORY W OF THIS
REGION FOR THE REST OF OUR FORECAST AREA.
GKS
&&
.LONG TERM...
ISSUED AT 329 AM CDT SAT JUN 30 2012 (TONIGHT TO FRIDAY)
MAIN QUESTION WILL BE HOW LOCATION OF EFFECTIVE FRONT AND
ATTENDANT CLOUDS/SLIGHT RAIN CHANCES WILL AFFECT ONGOING HEAT
WAVE. DO NOT THINK THAT IT WILL BE ENOUGH TO PREVENT HEAT INDEX
READINGS FROM CLIMBING INTO THE 100-106 RANGE BOTH TOMORROW AND
MONDAY. PLAN ON EXTENDING CURRENT HEAT WARNINGS/ADVISORIES INTO
MONDAY. WILL ALSO ADD STE. GENEVIEVE...ST. FRANCOIS AND MADISON
COUNTIES TO THE EXCESSIVE HEAT WARNING. FARMINGTON`S HEAT INDEX
WAS 106 YESTERDAY...AND WILL LIKELY BE NEAR 105 TODAY AND
TOMORROW.
THINK THAT CHANCE OF THUNDERSTORMS MENTIONED ABOVE WILL LINGER
INTO EARLY EVENING OVER FAR NORTHEAST MISSOURI INTO WEST CENTRAL
ILLINOIS ALONG STATIONARY FRONT. THIS FRONT DOES LOOK TO MOVE
NORTH LATE THIS EVENING INTO SUNDAY AS UPPER RIDGE BEGINS TO BUILD
OVER THE AREA...SO WILL ONLY KEEP SLIGHT CHANCES FOR THUNDERSTORMS
GOING OVER THE FAR NORTHERN PART OF THE CWA INTO EARLY SUNDAY.
THINK THAT THE REST OF THE WEEKEND WILL BE MAINLY DRY AS THE FRONT
MOVES TO THE NORTH. INTERESTINGLY...THE NAM DEVELOPS A BULLSEYE OF A
QUARTER OF AN INCH OF RAINFALL OVER THE SOUTHERN CWA DURING SUNDAY
AFTERNOON WHERE THE ATMOSPHERE WILL BECOME VERY UNSTABLE AND
UNCAPPED IN AN AREA OF WEAK LOW LEVEL CONVERGENCE. THIS SEEMS
UNLIKELY GIVEN THAT THE AREA WILL BE UNDER THE UPPER RIDGE SO WILL
LEAVE THE AREA DRY FOR NOW.
STILL EXPECT TEMPERATURES TO REACH THE TRIPLE DIGITS BOTH SUNDAY AND
MONDAY GIVEN DEEP MIXING TO 700MB AND 850MB TEMPERATURES STAYING IN
THE 22-25C RANGE. STILL EXPECT DEWPOINTS TO FALL BACK INTO THE
UPPER 50S AND LOWER 60S TO THE SOUTH OF I-70 BOTH DAYS...BUT THE
BETTER PERFORMING NAM MOS GUIDANCE HAS HIGHS IN THE 99-105 RANGE.
FARTHER NORTH...DEWPOINTS WILL BE HIGHER CLOSER THE RETREATING FRONT
WITH SLIGHTLY COOLER TEMPERATURES KEEPING HEAT INDEX READINGS AROUND
100 DEGREES.
MEDIUM RANGE MODELS ARE SHOWING SOME DISAGREEMENT NEXT WEEK WHICH
LOWERS THE OVERALL CONFIDENCE FOR THE HOLIDAY WEEK FORECAST. THE
MODELS DO DEPICT A GRADUAL RISE IN HEIGHTS AS THE UPPER HIGH NOW
OVER THE SOUTHWESTERN CONUS MOVES TO THE NORTHEAST. THE GFS
DEVELOPS SOME LIGHT QPF OVER IL ON EASTERN PERIPHERY OF THE BUILDING
HIGH. THE NEW ECMWF BRINGS A TROPICAL SYSTEM UP INTO SOUTHERN MO ON
TUESDAY AHEAD OF THE HIGH. WILL DISCOUNT BOTH OF THESE SOLUTIONS
FOR NOW WITH THE BUILDING RIDGE AND GO WITH CONTINUITY WHICH MEANS
STAYING WITH THE HOT AND DRY FORECAST. BOTH MODELS STILL HAVE
850MB TEMPS IN THE 22-24C RANGE WHICH SUPPORT HIGHS NEAR 100.
BRITT
&&
.AVIATION...
ISSUED AT 525 AM CDT SAT JUN 30 2012
FOR NOW WILL LEAVE PRECIPITATION OUT OF THE UIN TAF...BUT COULD
NOT RULE OUT AN ISOLATED SHOWER OR STORM TODAY AND TONIGHT ALONG
OUTFLOW BOUNDARIES FROM CONVECTION ACROSS IA AND NRN IL AND AS A
WEAK FRONT SAGS SWD INTO EXTREME NRN MO AND CNTRL IL THIS EVNG.
THERE WILL BE SOME MID-HIGH LEVEL CLOUDS IN UIN WITH LITTLE IF ANY
CLOUD COVER FURTHER S AT THE REST OF THE TAF SITES THIS FORECAST
PERIOD. ALTHOUGH OUTFLOW BOUNDARIES HAVE CAUSED A TEMPORARY CHANGE
IN WIND DIRECTION IN UIN AND STL EARLY THIS MRNG...THE PREVAILING
W-SWLY SFC WIND SHOULD RETURN LATER THIS MRNG INCREASING TO AROUND
11-12 KTS WITH SOME GUSTS POSSIBLE. THE SFC WINDS SHOULD BECOME
LIGHT AGAIN THIS EVNG.
SPECIFICS FOR KSTL...THE CURRENT N-NW WIND AT STL SHOULD SWITCH
BACK TO A W-SWLY SFC WIND LATER THIS MRNG AND INCREASE TO AROUND
11-12 KTS WITH SOME GUSTS. ONLY SOME HIGH LEVEL CLOUDS EXPECTED
THIS FORECAST PERIOD. THE SFC WIND WILL BECOME LIGHT AGAIN THIS
EVNG.
GKS
&&
.FIRE WEATHER...
ISSUED AT 329 AM CDT SAT JUN 30 2012
STILL PLAN ON GOING WITH HEIGHTENED FIRE DANGER WORDING FOR TODAY AND
SUNDAY. WINDS WILL STAY BELOW 15 MPH OVER THE SOUTHERN PART OF
THE CWA WHICH IS THE MOST LIKELY AREA TO HAVE MINIMUM RELATIVE
HUMIDITY VALUES FALL BELOW 20 PERCENT. FORECAST 10 HOUR DEAD
FUELS WILL BE 8 PERCENT OR LESS. THESE CONDITIONS WILL CONTINUE INTO
NEXT WEEK. WILL CONTINUE TO USE APPROPRIATE WORDING IN THE FIRE
WEATHER FORECAST...SPECIAL WEATHER STATEMENTS...AND HAZARDOUS
WEATHER OUTLOOK.
BRITT
&&
.CLIMATE...
ISSUED AT 329 AM CDT SAT JUN 30 2012
RECORD HIGHS
DATE ST. LOUIS COLUMBIA QUINCY
----------------------------------------------
JUNE 30 103(1931) 103(1901) 103(1931)
JULY 01 105(1980) 110(1980) 104(1930)
JULY 02 101(1933) 102(1901) 103(1934)
JULY 03 101(1934) 104(1901) 104(1911)
JULY 04 102(1990) 106(1901) 103(1936)
JULY 05 102(1938) 105(1911) 104(1911)
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...HEAT ADVISORY UNTIL 7 PM CDT MONDAY FOR AUDRAIN MO-BOONE MO-
CALLAWAY MO-COLE MO-CRAWFORD MO-FRANKLIN MO-GASCONADE MO-
IRON MO-KNOX MO-LEWIS MO-LINCOLN MO-MARION MO-MONITEAU MO-
MONROE MO-MONTGOMERY MO-OSAGE MO-PIKE MO-RALLS MO-REYNOLDS
MO-SHELBY MO-WARREN MO-WASHINGTON MO.
EXCESSIVE HEAT WARNING UNTIL 7 PM CDT MONDAY FOR JEFFERSON MO-
MADISON MO-ST. CHARLES MO-ST. FRANCOIS MO-ST. LOUIS CITY MO-
ST. LOUIS MO-STE. GENEVIEVE MO.
IL...HEAT ADVISORY UNTIL 7 PM CDT MONDAY FOR ADAMS IL-BROWN IL-
CALHOUN IL-PIKE IL.
EXCESSIVE HEAT WARNING UNTIL 7 PM CDT MONDAY FOR BOND IL-CLINTON
IL-FAYETTE IL-GREENE IL-JERSEY IL-MACOUPIN IL-MADISON IL-
MARION IL-MONROE IL-MONTGOMERY IL-RANDOLPH IL-ST. CLAIR IL-
WASHINGTON IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS GLASGOW MT
911 AM MDT SAT JUN 30 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH MONDAY...
AN UPPER RIDGE SLIDING OVER NORTHEAST MONTANA TODAY WILL STABILIZE
THE ATMOSPHERE AND BRING A SUNNY...AND QUIET WEATHER DAY. WITH
DESERT AIR CONFINED SOUTH OF MONTANA...THE DAY WILL BE SLIGHTLY
COOLER THAN YESTERDAY...BUT STILL WARM AND ABOVE AVERAGE. A WEAK
SURFACE PRESSURE GRADIENT WITH A SURFACE TROUGH TO OUR EAST WILL
LIMIT MOST WESTERLY WINDS TODAY TO AROUND 10KTS OR LESS. HOWEVER
AFTERNOON WINDS OF 15 KTS OR LESS ARE POSSIBLE NEAR THE
YELLOWSTONE RIVER AREA. MADE ONLY MINOR GRID EDITS TO SKY AND
WIND. SCT
PREVIOUS DISCUSSION...
SYNOPTIC SET UP... A LARGE THERMAL RIDGE EXTENDS FROM THE FOUR
CORNERS UP INTO CENTRAL AND NORTHERN PLAINS... WHILE AN EQUALLY
LARGE TROUGH SETS OFF THE COAST OF THE PACIFIC NORTHWEST AND
EXTENDS UP INTO BRITISH COLUMBIA AND THE GULF OF ALASKA.
NORTHEASTERN MONTANA LIES WEDGED IN BETWEEN THESE TWO LARGE
FEATURES ON THE WARMER SIDE OF SOUTHWEST FLOW. THIS FLOW PATTERN
ALLOWS FOR SMALLER RIDGES AND TROUGHS TO QUICKLY MOVE THROUGH THE
AREA.
TODAY THOUGH TONIGHT... RAPID TRANSITION FROM ZONAL FLOW TO
RIDGING IS ANTICIPATED. THIS SHOULD PUT A DAMPER ON SHOWERS
ACROSS THE AREA FOR THE NEXT 24 HOURS. HOWEVER... TEMPERATURES
WILL BE ON THE RISE ALONG WITH SOUTHEAST WINDS WHICH SHOULD
SUPPORT THE WARMING. SKIES WILL BE CLEAR TO PARTLY CLOUD WITH
INCREASINGLY MUGGY CONDITIONS AS A SURFACE BASED LEE SIDE MOUNTAIN
TROUGH SETS UP OFF THE FRONT RANGE AND BEGIN PULLING IN HIGHER
DEW-POINTS AT THE SURFACE FROM THE SOUTHEAST.
SUNDAY THROUGH SUNDAY NIGHT... A LOBE OF VORTICITY OFF THE LARGE
SYNOPTIC TROUGH WILL ZOOM ONSHORE AND MAKE A BEELINE FOR
NORTHERN MONTANA. THIS ENERGY WILL FORM A LOW OVER SOUTHERN
SASKATCHEWAN AND LATCH ONTO THE LEE SIDE MOUNTAIN TROUGH DRAGGING
IT ACROSS NORTHEAST MONTANA. THE LEE TROUGH WILL THEN BECOME A
FOCAL POINT FOR AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS.
THE STORMS SHOULD EXIT THE AREA MONDAY MORNING.
THESE STORMS WILL EASILY BECOME SEVERE.
SEVERE POTENTIAL WILL BE AIDED BY AN ATMOSPHERIC RIVER GETTING ITS
FETCH OFF OF THE PACIFIC. IT IS MOST NOTICEABLE AROUND THE 700MB
LEVEL IN MIXING RATIOS AND WILL BE RAISING PRECIPITABLE WATER FOR
POINT SOUNDINGS TO BETWEEN 1 AND 1.5 INCHES. CURRENTLY... A LINE
OF THUNDERSTORMS IS ANTICIPATED FORM ON THE LEE TROUGH DURING PEAK
HEATING AROUND 2 TO 4 PM ALONG A LINE FROM OPHEIM TO GLASGOW TO
JORDAN AND DOWN TO MILES CITY AND THEN SLOWLY MOVE EAST. QPF
FIELDS IN MODELS HINT TOWARDS SOME POTENTIAL BACK BUILDING SO
FLASH FLOODING DUE TO TRAINING MAY BE POSSIBLE. CAPE VALUES ARE
RUNNING BETWEEN 1500 TO 3000 J/KG. THE HAIL GROWTH ZONE WILL BE
AROUND 25 KFT AND CAPE AT THAT LEVEL SHOULD BE MORE THAN
SUFFICIENT TO FORM QUARTERS AND POSSIBLY A FEW GOLF BALLS. AN
INVERTED V SOUNDING IS PRESENT... HOWEVER SYNOPTIC WINDS APPEAR TO
BE LACKLUSTER. THE SURFACE PROFILE FOR THESE STORMS SHOULD ALSO
MODIFY DUE TO THE HIGH PW. BECAUSE OF THIS...STRONG WINDS WILL BE
POSSIBLE WITH INDIVIDUAL CELLS BUT PROBABLY WILL NOT BE THE MAIN
SHOW. ANYWHERE BETWEEN 25 TO 35 KTS OF SHEAR OVER THE 0-6KM SEEMS
SUFFICIENT TO MAINTAIN LONG LASTING SUPERCELLS ALONG BROKEN LINE
SEGMENTS.
NAM AND GFS ARE BOTH SHOWING THIS EVENT BUT FURTHER DETAILS MAY
BE SKETCHY UNTIL 12 TO 18 HOURS IN WHEN HIRESARW AND HRRR MODELS
CAN START PINNING MOST LIKELY STORM GROWTH AREAS OR WATER VAPOR
IMAGERY BEGINS TO PICK UP ON THE STRONGEST JET STREAKS.
MONDAY... FLOW WILL TRANSITION BACK FROM SOUTHWEST TO MORE ZONAL
BY THE AFTERNOON. A SLIGHT COOL DOWN IS ANTICIPATED WITH DRY
CONDITIONS AND PARTLY CLOUDY SKIES. GAH
.LONG TERM...MONDAY NIGHT THROUGH SATURDAY...
UPPER RIDGE CONTINUES TO DOMINATE OVER THE CENTRAL PORTION OF THE
COUNTRY WITH TROF OVER THE PACIFIC NORTHWEST. SOUTHWEST FLOW WILL
PULL HOT AIR AND MODERATELY DRY AIR INTO THE REGION FOR MOST OF
THE WEEK. NO PARTICULARLY STRONG SYSTEMS EXPECTED FOR DEVELOPMENT
OF CONVECTION...BUT MAY HAVE A WAVE PUSH INTO CENTRAL CANADA
TUESDAY OR TUESDAY NIGHT AND ANOTHER WAVE OR SERIES OF WAVES LATE
IN THE WEEK. EBERT
&&
.AVIATION...
A HIGH PRESSURE MID LEVEL AND SURFACE RIDGE WILL CONTROL
CONDITIONS THROUGH SUNDAY MORNING LEADING TO CLEAR SKIES AND LIGHT
WINDS FOR THE AREA. WINDS SHOULD BE NORTHWESTERLY AT 5 TO 10 KTS
UNTIL EARLY SUNDAY MORNING WHEN THE PASSAGE OF A WEAK SURFACE
RIDGE WILL SHIFT WINDS TO THE SOUTHEAST AND INCREASE THEM TO 10
TO 15 KTS. MARTIN
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS HASTINGS NE
940 AM CDT SAT JUN 30 2012
.UPDATE...WENT AHEAD AND PULLED MENTION OF FOG FROM THE
FORECAST...AS VISIBILITIES IN SURFACE OBSERVATIONS HAVE BEGUN TO
INCREASE ACROSS THE REGION. ALSO PER RADAR IMAGERY SOME MID LEVEL
RETURNS HAVE BEGUN TO SHIFT EASTWARD ACROSS PORTIONS OF FURNAS AND
GOSPER COUNTIES THIS MORNING. ADDED SLIGHT CHANCES FOR RAIN
SHOWERS ACROSS THE FAR WEST...ALTHOUGH NOT EXPECTING MUCH MORE
THAN A SPRINKLE.
&&
.PREV DISCUSSION... /ISSUED 646 AM CDT SAT JUN 30 2012/
UPDATE...11Z SURFACE ANALYSIS INDICATES A STATIONARY SURFACE
BOUNDARY EXTENDING FROM NEAR KGLD...TO NEAR KHJH...TO JUST SOUTH
OF KLNK. A NORTHEASTERLY LOW LEVEL WIND FIELD AND SUFFICIENT POOLING
OF LOW LEVEL MOISTURE IS NOTED JUST NORTH/NORTHWEST OF THIS
BOUNDARY...WITH FOG NOW DEVELOPING ALONG AN AXIS WHICH EXTENDS
FROM WEST TO EAST SOUTH OF I-80 AND NORTH OF HIGHWAY 6. MOST
LOCATIONS ARE EXPERIENCING VISIBILITY RESTRICTIONS OF 2-5
MILES...BUT WITHIN THE PAST HOUR THREE SITES INCLUDING KHSI...KEAR
AND KHDE HAVE FALLEN 1/4SM OR LESS. WENT AHEAD AND UPDATED THE
FORECAST TO INCLUDE FOG MENTION SOUTH OF I-80 AND NORTH OF HIGHWAY
6 THROUGH 14Z. RAP ANALYSIS PROXIMITY SOUNDINGS FROM ACROSS CENTRAL
PORTIONS OF OUR CWA INDICATE THIS MOIST BOUNDARY LAYER IS VERY
SHALLOW AND SHOULD MIX OUT QUICKLY ONCE DIABATIC HEATING
INTENSIFIES IN THE NEXT HOUR OR SO. GIVEN ALL THIS...WILL HOLD OFF
FROM ANY FOG HEADLINES FOR NOW...BUT DID INCLUDE RESTRICTED
VISIBILITIES IN THE HWO AND INTRODUCED A NOW-CAST.
PREV DISCUSSION... /ISSUED 546 AM CDT SAT JUN 30 2012/
AVIATION...12Z KGRI TAF. THE WIND WILL GRADUALLY SHIFT FROM
EASTERLY TO SOUTHERLY DURING THE TAF VALID TIME. THE WIND WILL BE
OUT OF THE EAST OR EAST SOUTHEAST THROUGH MUCH OF THE DAY WITH THE
SHIFT TO SOUTHERLY WINDS HAPPENING LATER TONIGHT. THUNDERSTORM
CHANCES LATE THIS AFTERNOON INTO TONIGHT REMAIN AT 20 PERCENT OR
LESS AND WILL NOT BE INCLUDED RAIN CHANCES IN THE TAF DUE TO THE
PROBABILITY BEING VERY LOW. AM CONCERNED ABOUT LOW STRATUS CREEPING
IN FROM THE WEST AND HAVE ADDED A TEMPO GROUP TO ACCOUNT FOR THIS
POSSIBILITY.
PREV DISCUSSION... /ISSUED 422 AM CDT SAT JUN 30 2012/
SHORT TERM...TODAY THROUGH MONDAY NIGHT. HOT WEATHER WILL
CONTINUE TODAY...BUT THERE IS A SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS LATER THIS AFTERNOON THROUGH SUNDAY MORNING. MAINLY
DRY WEATHER CAN THEN BE EXPECTED SUNDAY AFTERNOON THROUGH THE END
OF THE SHORT TERM PERIOD MONDAY NIGHT.
TODAY...THERE WILL BE A SFC FRONTAL BOUNDARY LOCATED NEAR OR JUST
NORTH OF THE NEBRASKA KANSAS BORDER...WHICH WILL ACT AS A FOCUSING
MECHANISM FOR THUNDERSTORMS LATER THIS AFTERNOON. IN
ADDITION...THERE WILL BE A WEAK SHORT WAVE MOVING ACROSS THE
NORTHERN PLAINS. THE 00Z GFS...00Z ECMWF...AND 06Z NAM ALL INDICATE
THE POTENTIAL OF AFTERNOON AND EVENING THUNDERSTORMS. INSTABILITY
WILL BE HIGH BUT DEEP LAYER SHEAR WILL BE MARGINAL. STEERING WINDS
ARE WEAK AND THUNDERSTORMS WILL BE SLOW MOVERS WITH COVERAGE
SOMEWHAT ISOLATED. THE CHANCE OF PRECIPITATION THROUGH SUNDAY
MORNING IS FAIRLY LOW AT AROUND 20 PERCENT...BUT THIS APPEARS TO
STILL BE THE BEST SHOT OF PRECIPITATION OVER THE WEEK AHEAD. A FEW
THUNDERSTORMS COULD BECOME STRONG TO SEVERE GIVEN THE HIGH
INSTABILITY. HEAT INDEX VALUES THIS AFTERNOON WILL AGAIN NEAR BUT
REMAIN BELOW ADVISORY CATEGORY.
SUNDAY INTO MONDAY...THE SFC FRONT LIFTS NORTH SUNDAY MORNING
TAKING PRECIPITATION CHANCES NORTH AND OUT OF OUR AREA BY LATE
SUNDAY MORNING. SOUTH WINDS WILL INCREASE AND ACT TO PUMP
TEMPERATURES UP A FEW MORE DEGREES WITH SUNDAY EXPECTED TO BE
WARMER THAN SATURDAY...AND MONDAY SHOULD BE A BIT WARMER THAN
SUNDAY. HEAT INDEX VALUES ACROSS KANSAS ON MONDAY WILL BE RIGHT
NEAR THE 105 CRITERIA FOR ISSUING HEAT ADVISORIES.
LONG TERM...STARTING 12Z TUESDAY. UPPER LEVEL RIDGING WILL
CONTINUE TO PROMOTE LITTLE IN THE WAY OF KINEMATIC FORCING DURING
THE LONG TERM FORECAST PERIOD...THUS PRESENTING DRY CONDITIONS
TUESDAY THROUGH FRIDAY. LITTLE CHANGE IN THE LOW LEVEL AIRMASS
DURING THIS SAME TIME PERIOD SUGGESTS ABOVE-NORMAL TEMPERATURES
WILL ALSO PERSIST THROUGH THE LONG TERM FORECAST PERIOD...WITH
AFTERNOON HIGHS IN THE 90S TO LOW 100S AND OVERNIGHT LOW IN THE
70S.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
856 AM CDT SAT JUN 30 2012
.DISCUSSION...
SMALL AREA OF SHOWERS AND ISOLATED THUNDERSTORMS IS MOVING ACROSS
CENTRAL SD/CENTRAL NEB AND TOWARD NORTHEAST NEB. RAP ANALYSIS
INDICATES MID-LEVEL LAPSE RATES OF 9C AND AN AXIS OF 850MB
MOISTURE JUST AHEAD OF THE SHOWERS...INDICATING A SUPPORTIVE
ENVIRONMENT FOR SHOWERS TO PERSIST INTO NORTHEAST NEB FOR AT LEAST
ANOTHER COUPLE OF HOURS. HAVE ADDED A SMALL AREA OF ISOLATED
SHRA/ISO TS MENTION TO THE NORTHWESTERNMOST CWA.
MAYES
&&
.PREV DISCUSSION... /ISSUED 659 AM CDT SAT JUN 30 2012/
AVIATION...
12Z TAFS FOR KOFK...KLNK AND KOMA.
GENERALLY VFR CONDITIONS EXPECTED THROUGH THE PERIOD WITH
SOME POTENTIAL FOR WIDELY SCATTERED THUNDERSTORMS AFTER 21Z
AS UPPER WAVE INDICATED TO MOVE INTO THE REGION. NOTHING
MENTIONED AT THIS TIME DUE TO UNCERTAINTY IN TIMING AND
STRENGTH.
FOBERT
PREV DISCUSSION... /ISSUED 320 AM CDT SAT JUN 30 2012/
DISCUSSION...
VERY SUBTLE WAVE MOVING THROUGH AREA HAS IGNITED ISOLATED STORMS
EARLY THIS MORNING...BUT ONLY IN A COUPLE OF COUNTIES IN OUR AREA
IN WEST CENTRAL IOWA. BELIEVE THAT ANY OF THIS ACTIVITY WOULD BE
EAST OF THE FORECAST AREA BY 6 AM.
MEANWHILE...STALLED SURFACE FRONT WILL REMAIN PARKED NEAR THE
NE/KS BORDER REGION TODAY...WHICH MAY PROVIDE A TRIGGER FOR
ISOLATED THUNDERSTORMS IN SOUTHEAST NEBRASKA LATER THIS AFTERNOON
THROUGH PEAK HEATING AS THE CAP WEAKENS. OTHERWISE...HIGH CLOUDS
WILL DRIFT ACROSS THE REGION FROM THE WEST TODAY...BUT IT SHOULD
STILL BE ANOTHER HOT DAY WITH HIGHS IN THE LOWER/MID 90S ALONG
WITH AN EASTERLY SURFACE FLOW. VERY OPPRESSIVE HUMIDITY OF RECENT
DAYS HAS MIXED OUT JUST A BIT...THUS HEAT INDEX VALUES TODAY...
WHILE STILL HOT...WILL BE JUST BELOW ADVISORY CRITERIA.
FOR TONIGHT...WITH THE SURFACE FRONT STILL IN THE AREA...AN
ISOLATED THUNDERSTORM MAY LINGER ALONG IT EARLY IN THE EVENING IN
SOUTHEAST NEBRASKA. OTHERWISE...A VERY SUBTLE WAVE MOVING THROUGH
THE ROCKIES COULD GENERATE CONVECTION ACROSS THE HIGH PLAINS WHICH
COULD MOVE INTO OUR LOCAL AREA BY MIDNIGHT AND BEYOND...ESPECIALLY
INTO NORTHEAST NEBRASKA NEBRASKA WHERE THE LOW LEVEL JET MAY BE
FOCUSED...THUS HAVE SLIGHTLY HIGHER POPS THERE TO ACCOUNT FOR A
POSSIBLE MCS THAT MAY ALSO DEVELOP ALONG THE NE/SD/IA BORDER AREA
LATE IN THE NIGHT AS WELL.
IF THE PREVIOUSLY MENTIONED MCS DOES DEVELOP...IT COULD LINGER
SUNDAY MORNING FOR AREAS NORTH OF I80. THEREAFTER...THE STALLED
FRONT DOES BEGIN TO LIFT THROUGH THE DAY SUNDAY AFTERNOON...WHICH
COULD TRIGGER ADDITIONAL ISOLATED THUNDERSTORMS THAT COULD LINGER
THROUGH SUNDAY EVENING AS THE FRONT CONTINUES TO LIFT NORTH OF THE
REGION.
FOR MONDAY THROUGH FRIDAY...THE UPPER RIDGE REBUILDS ACROSS THE
CENTRAL US WITH NO DISCERNIBLE FRONTAL BOUNDARIES IN OUR AREA
WITH CONTINUED SOUTH TO SOUTHWEST FLOW. THIS WILL RESULT IN A WEEK
OF VERY HOT AND DRY CONDITIONS INCLUDING THE INDEPENDENCE DAY
HOLIDAY. DAYTIME HIGHS WILL BE IN THE MID TO UPPER 90S EVERY
DAY...VERY NEAR 100 AT TIMES. HUMIDITY WILL NOT BE EXTREMELY
OPPRESSIVE...BUT WILL BE JUST ENOUGH TO RESULT IN DAILY HEAT INDEX
VALUES OF 100 TO 105 EVERY DAY...BUT GENERALLY BELOW ADVISORY
CRITERIA. THERE IS SOME HINT IN THE MODELS THAT THE RIDGE MAY
BREAK DOWN JUST A BIT BY NEXT WEEKEND ALLOWING FOR VERY SMALL
CHANCES FOR RAIN TO RETURN BY SATURDAY AND SUNDAY.
DEWALD
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
846 AM CDT SAT JUN 30 2012
.UPDATE...UPDATED FCST TO INCLUDE MENTION OF ISOLATED
THUNDERSTORMS IN NORTHEAST ZONES AS WELL AS SOUTHEAST ZONES.
APPEARS ELEVATED INSTABILITY AHEAD OF APPROACHING SHORTWAVE
ROUNDING FLATTENED RIDGE WORKING TO PRODUCE ISOLATED STORMS.
ADDITIONAL DEVELOPMENT POSSIBLE THIS MORNING INTO AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 639 AM CDT SAT JUN 30 2012/
AVIATION...
LIGHT EAST TO SOUTHEAST WIND IN THE PLATTE RIVER VALLEY WILL
CONTINUE TO PRODUCE FOG IN THE VICINITY OF LBF. CEILING AND
VISIBILITY COULD EVEN GO BELOW INSTRUMENT MINIMA AT TIMES. AFTER
SUNRISE...THE FOG SHOULD LIFT FAIRLY QUICKLY. THEN...UNRESTRICTED
CONDITIONS CAN BE EXPECTED INTO THE AFTERNOON.
THERE IS LITTLE AGREEMENT AMONG FORECAST SIMULATIONS REGARDING
THE POSSIBILITY OF THUNDERSTORMS IN CENTRAL AND WESTERN NEBRASKA
THIS AFTERNOON AND OVERNIGHT. WITH A FRONT OSCILLATING NORTH AND
SOUTH ACROSS NEBRASKA...THERE IS A SYSTEM TO TRIGGER AT LEAST WIDELY
SCATTERED THUNDERSTORMS OVER MUCH OF THE AREA. ALTHOUGH MY
CONFIDENCE IN THAT FORECAST IS NOT HIGH...I AM RELUCTANT TO DROP THE
PROB30 GROUPS FROM THE FORECASTS FOR LBF AND VTN SINCE THEY HAVE
BEEN IN THE FORECASTS FOR BOTH THE 00Z AND 06Z SCHEDULED TAF CYCLES.
THE STATISTICAL OUTPUT FROM THE TWO PRIMARY MODELS INDICATES THAT A
MENTION OF THUNDERSTORMS MIGHT BE APPROPRIATE. ANYWAY...THE HIGHEST
PROBABILITY OF THUNDERSTORMS IN CENTRAL AND WESTERN NEBRASKA IS THIS
EVENING 00-06Z. OUTSIDE OF THUNDERSTORMS...FLIGHT CONDITIONS ARE
WILL BE UNRESTRICTED.
PREV DISCUSSION... /ISSUED 406 AM CDT SAT JUN 30 2012/
DISCUSSION...
UPPER LEVEL RIDGING REMAINS IN PLACE ACROSS THE CENTRAL
PLAINS...WITH LONGWAVE TROUGHS OVER THE EASTERN PACIFIC AND
EASTERN CANADA. THE LOCAL AREA WAS IN AN AREA OF SUBSIDENCE BEHIND
A SYSTEM WHICH HAD MOVED INTO IOWA/ILLINOIS. WATER VAPOR IMAGERY
SHOWED THIS PATTERN...AND ALSO PICKED UP ON A SHORTWAVE TROUGH
OVER WESTERN WYOMING.
AT THE SURFACE...DEWPOINTS ACROSS THE FORECAST AREA RANGED FROM
THE 40S IN THE EASTERN PANHANDLE TO AROUND 70 AT KLBF.
OBSERVATIONS INDICATED A BOUNDARY FROM AROUND KIEN TO KOGA THROUGH
KMCK AND INTO NORTH CENTRAL KANSAS WITH EASTERLY WINDS ON THE EAST
SIDE OF THE BOUNDARY.
HOW TODAY/S WEATHER PANS OUT WILL DEPEND ON IF CONVECTION DEVELOPS
AHEAD OF THE WYOMING SHORTWAVE THIS MORNING. THE 30.00Z AND 30.06Z
NAM FIRE STORMS OVER THE PANHANDLE BETWEEN 12Z AND 15Z AND THE
RAPID REFRESH DOES SHOW SOME INDICATIONS OF CONVECTION IN THESE
AREAS...BUT THESE ARE THE ONLY MODELS TO DO SO. THE GFS/EC/GEM
ARE ALL DRY WHILE THE LATEST HRRR AND DOES DEVELOP STORMS...BUT
KEEPS THEM OVER SOUTH DAKOTA. ALTHOUGH THE NAM IS THE
OUTLIER...THERE IS ELEVATED INSTABILITY AND MOISTURE IN THE AREA
AND WITH THE WAVE MOVING ACROSS THE REGION...DON/T WANT TO
DISCOUNT ITS OUTPUT. THE ACTIVITY OVER WYOMING IS VERY HIGH BASED
/AROUND 11K FEET/. WILL ASSUME THAT TREND WILL CONTINUE WITH THE
MORNING HOURS BRINGING SOME SCATTERED RADAR RETURNS WITH NO
MEASURABLE RAIN TO THE NORTHWEST PART OF THE FORECAST AREA. THERE
COULD BE AN ISOLATED LIGHTNING STRIKES...AND COLLAPSING
SHOWERS/STORMS COULD CAUSE SOME GUSTY WINDS. FOR THE
AFTERNOON...PEAK HEATING...INSTABILITY AND A WEAK SHORTWAVE
PASSING SHOULD BE ENOUGH FOR STORMS TO DEVELOP. THESE STORMS TOO
WILL BE HIGH BASED AND WITH QUITE A BIT OF DRY AIR IN THE BOUNDARY
LAYER DON/T HAVE A LOT OF CONFIDENCE ON THE COVERAGE OF MEASURABLE
RAINFALL. WITH THESE CHANCES AND AS THE LOW LEVEL JET PICKS UP
THIS EVENING...KEPT CHANCES IN THE FORECAST AT THROUGH TONIGHT.
NOT A MAJOR THREAT FOR SEVERE STORMS AS THE WARMTH OF THE LAYER
ALOFT SHOULD PRECLUDE THE CHANCES FOR LARGE HAIL TO MAKE IT TO THE
GROUND. THERE IS 30 TO 45KTS OF DEEP LAYER SHEAR SO CAN/T DISCOUNT
AN ISOLATED ORGANIZED STORM BUT THINKING THE PRIMARY THREAT WILL
BE STRONG WINDS. DID DROP HIGH TEMPERATURES BY A FEW DEGREES TODAY
DUE MAINLY TO THE HIGHER CLOUD COVER EXPECTED. BUT IT WILL STILL
BE VERY WARM WITH HIGHS IN THE MID TO UPPER 90S MOST LOCATIONS.
THE UPPER LEVEL TROUGH OVER THE PACIFIC WILL MOVE ONSHORE
TONIGHT...WHICH WILL BEGIN TO AMPLIFY THE FLOW AGAIN WITH THE
RIDGE BUILDING NORTH ACROSS THE PLAINS THROUGH MONDAY. THE MODELS
ARE TRYING TO PUSH A SHORTWAVE TROUGH OVER THE RIDGE ACROSS
WYOMING AND SOUTH DAKOTA ON SUNDAY SO DEVELOP PRECIPITATION OVER
THE AREA. WARM AIR ALOFT MAY KEEP SOME OF THIS FROM HAPPENING SO
MAY HAVE HIGHER CHANCES OVER THE HIGHER TERRAIN BUT WILL KEEP A
SLIGHT CHANCE OVER THE NORTHEASTERN COUNTIES AS WELL. THEN MONDAY
WILL BE DRY AS NEBRASKA SITS RIGHT UNDER THE RIDGE. FOR
TEMPERATURES...FORECAST SOUNDINGS SHOWING FULL MIXING ON SUNDAY
AND MONDAY. DID TAKE INTO ACCOUNT HIGHER CLOUD COVER ESPECIALLY OVER
THE NORTHERN PARTS OF THE FORECAST AREA SUNDAY SO DIDN/T GO AS
WARM IN THE FORECAST IN THOSE AREAS. STILL EXPECTING MID TO
UPPER 90S THOUGH. MONDAY SHOULD BE A BIT WARMER WITH MUCH OF THE
AREA LOOKING TO BE INTO THE TRIPLE DIGITS AGAIN.
NO END IS IN SITE FOR THE WARMTH AS THE MODELS KEEP THE RIDGE IN
PLACE THROUGH THE REMAINDER OF NEXT WEEK. THIS LEADS TO LOW
CHANCES FOR RAIN AND HOT TEMPERATURES. HIGHS LOOK TO BE IN THE MID
TO UPPER 90S AND SOME DAYS HITTING 100 DEGREES OR BETTER. BY
FRIDAY EVENING THE RIDGE MAY SHIFT EAST FAR ENOUGH FOR STORMS
DEVELOPING OVER COLORADO AND WYOMING TO MOVE INTO THE EASTERN
PANHANDLE. BUT UNTIL THEN THE FORECAST LOOKS DRY FOR MUCH OF NEXT
WEEK.
FIRE WEATHER...
THE CURRENT FORECAST DOESN/T HAVE ANY DAYS WITH CONDITIONS
REACHING CRITICAL FIRE WEATHER CRITERIA. SUNDAY MAY BE CLOSE WITH
BREEZY SOUTHERLY WINDS AND RELATIVE HUMIDITY FORECAST BETWEEN 15
AND 20 PERCENT OVER SOUTHWEST NEBRASKA. WILL NEED TO CONTINUE TO
WATCH FOR FIRE POTENTIAL OVER THE NEXT WEEK AS THE HEAT AND DRY
WEATHER CONTINUE.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...JWS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
646 AM CDT SAT JUN 30 2012
.UPDATE...11Z SURFACE ANALYSIS INDICATES A STATIONARY SURFACE
BOUNDARY EXTENDING FROM NEAR KGLD...TO NEAR KHJH...TO JUST SOUTH
OF KLNK. A NORTHEASTERLY LOW LEVEL WIND FIELD AND SUFFICIENT POOLING
OF LOW LEVEL MOISTURE IS NOTED JUST NORTH/NORTHWEST OF THIS
BOUNDARY...WITH FOG NOW DEVELOPING ALONG AN AXIS WHICH EXTENDS
FROM WEST TO EAST SOUTH OF I-80 AND NORTH OF HIGHWAY 6. MOST
LOCATIONS ARE EXPERIENCING VISIBILITY RESTRICTIONS OF 2-5
MILES...BUT WITHIN THE PAST HOUR THREE SITES INCLUDING KHSI...KEAR
AND KHDE HAVE FALLEN 1/4SM OR LESS. WENT AHEAD AND UPDATED THE
FORECAST TO INCLUDE FOG MENTION SOUTH OF I-80 AND NORTH OF HIGHWAY
6 THROUGH 14Z. RAP ANALYSIS PROXIMITY SOUNDINGS FROM ACROSS CENTRAL
PORTIONS OF OUR CWA INDICATE THIS MOIST BOUNDARY LAYER IS VERY
SHALLOW AND SHOULD MIX OUT QUICKLY ONCE DIABATIC HEATING
INTENSIFIES IN THE NEXT HOUR OR SO. GIVEN ALL THIS...WILL HOLD OFF
FROM ANY FOG HEADLINES FOR NOW...BUT DID INCLUDE RESTRICTED
VISIBILITIES IN THE HWO AND INTRODUCED A NOW-CAST.
&&
.PREV DISCUSSION... /ISSUED 546 AM CDT SAT JUN 30 2012/
AVIATION...12Z KGRI TAF. THE WIND WILL GRADUALLY SHIFT FROM
EASTERLY TO SOUTHERLY DURING THE TAF VALID TIME. THE WIND WILL BE
OUT OF THE EAST OR EAST SOUTHEAST THROUGH MUCH OF THE DAY WITH THE
SHIFT TO SOUTHERLY WINDS HAPPENING LATER TONIGHT. THUNDERSTORM
CHANCES LATE THIS AFTERNOON INTO TONIGHT REMAIN AT 20 PERCENT OR
LESS AND WILL NOT BE INCLUDED RAIN CHANCES IN THE TAF DUE TO THE
PROBABILITY BEING VERY LOW. AM CONCERNED ABOUT LOW STRATUS CREEPING
IN FROM THE WEST AND HAVE ADDED A TEMPO GROUP TO ACCOUNT FOR THIS
POSSIBILITY.
PREV DISCUSSION... /ISSUED 422 AM CDT SAT JUN 30 2012/
SHORT TERM...TODAY THROUGH MONDAY NIGHT. HOT WEATHER WILL
CONTINUE TODAY...BUT THERE IS A SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS LATER THIS AFTERNOON THROUGH SUNDAY MORNING. MAINLY
DRY WEATHER CAN THEN BE EXPECTED SUNDAY AFTERNOON THROUGH THE END
OF THE SHORT TERM PERIOD MONDAY NIGHT.
TODAY...THERE WILL BE A SFC FRONTAL BOUNDARY LOCATED NEAR OR JUST
NORTH OF THE NEBRASKA KANSAS BORDER...WHICH WILL ACT AS A FOCUSING
MECHANISM FOR THUNDERSTORMS LATER THIS AFTERNOON. IN
ADDITION...THERE WILL BE A WEAK SHORT WAVE MOVING ACROSS THE
NORTHERN PLAINS. THE 00Z GFS...00Z ECMWF...AND 06Z NAM ALL INDICATE
THE POTENTIAL OF AFTERNOON AND EVENING THUNDERSTORMS. INSTABILITY
WILL BE HIGH BUT DEEP LAYER SHEAR WILL BE MARGINAL. STEERING WINDS
ARE WEAK AND THUNDERSTORMS WILL BE SLOW MOVERS WITH COVERAGE
SOMEWHAT ISOLATED. THE CHANCE OF PRECIPITATION THROUGH SUNDAY
MORNING IS FAIRLY LOW AT AROUND 20 PERCENT...BUT THIS APPEARS TO
STILL BE THE BEST SHOT OF PRECIPITATION OVER THE WEEK AHEAD. A FEW
THUNDERSTORMS COULD BECOME STRONG TO SEVERE GIVEN THE HIGH
INSTABILITY. HEAT INDEX VALUES THIS AFTERNOON WILL AGAIN NEAR BUT
REMAIN BELOW ADVISORY CATEGORY.
SUNDAY INTO MONDAY...THE SFC FRONT LIFTS NORTH SUNDAY MORNING
TAKING PRECIPITATION CHANCES NORTH AND OUT OF OUR AREA BY LATE
SUNDAY MORNING. SOUTH WINDS WILL INCREASE AND ACT TO PUMP
TEMPERATURES UP A FEW MORE DEGREES WITH SUNDAY EXPECTED TO BE
WARMER THAN SATURDAY...AND MONDAY SHOULD BE A BIT WARMER THAN
SUNDAY. HEAT INDEX VALUES ACROSS KANSAS ON MONDAY WILL BE RIGHT
NEAR THE 105 CRITERIA FOR ISSUING HEAT ADVISORIES.
LONG TERM...STARTING 12Z TUESDAY. UPPER LEVEL RIDGING WILL
CONTINUE TO PROMOTE LITTLE IN THE WAY OF KINEMATIC FORCING DURING
THE LONG TERM FORECAST PERIOD...THUS PRESENTING DRY CONDITIONS
TUESDAY THROUGH FRIDAY. LITTLE CHANGE IN THE LOW LEVEL AIRMASS
DURING THIS SAME TIME PERIOD SUGGESTS ABOVE-NORMAL TEMPERATURES
WILL ALSO PERSIST THROUGH THE LONG TERM FORECAST PERIOD...WITH
AFTERNOON HIGHS IN THE 90S TO LOW 100S AND OVERNIGHT LOW IN THE
70S.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE/LONG TERM...BRYANT
SHORT TERM/AVIATION...WESELY
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
639 AM CDT SAT JUN 30 2012
.AVIATION...
LIGHT EAST TO SOUTHEAST WIND IN THE PLATTE RIVER VALLEY WILL
CONTINUE TO PRODUCE FOG IN THE VICINITY OF LBF. CEILING AND
VISIBILITY COULD EVEN GO BELOW INSTRUMENT MINIMA AT TIMES. AFTER
SUNRISE...THE FOG SHOULD LIFT FAIRLY QUICKLY. THEN...UNRESTRICTED
CONDITIONS CAN BE EXPECTED INTO THE AFTERNOON.
THERE IS LITTLE AGREEMENT AMONG FORECAST SIMULATIONS REGARDING
THE POSSIBILITY OF THUNDERSTORMS IN CENTRAL AND WESTERN NEBRASKA
THIS AFTERNOON AND OVERNIGHT. WITH A FRONT OSCILLATING NORTH AND
SOUTH ACROSS NEBRASKA...THERE IS A SYSTEM TO TRIGGER AT LEAST WIDELY
SCATTERED THUNDERSTORMS OVER MUCH OF THE AREA. ALTHOUGH MY
CONFIDENCE IN THAT FORECAST IS NOT HIGH...I AM RELUCTANT TO DROP THE
PROB30 GROUPS FROM THE FORECASTS FOR LBF AND VTN SINCE THEY HAVE
BEEN IN THE FORECASTS FOR BOTH THE 00Z AND 06Z SCHEDULED TAF CYCLES.
THE STATISTICAL OUTPUT FROM THE TWO PRIMARY MODELS INDICATES THAT A
MENTION OF THUNDERSTORMS MIGHT BE APPROPRIATE. ANYWAY...THE HIGHEST
PROBABILITY OF THUNDERSTORMS IN CENTRAL AND WESTERN NEBRASKA IS THIS
EVENING 00-06Z. OUTSIDE OF THUNDERSTORMS...FLIGHT CONDITIONS ARE
WILL BE UNRESTRICTED.
&&
.PREV DISCUSSION... /ISSUED 406 AM CDT SAT JUN 30 2012/
DISCUSSION...
UPPER LEVEL RIDGING REMAINS IN PLACE ACROSS THE CENTRAL
PLAINS...WITH LONGWAVE TROUGHS OVER THE EASTERN PACIFIC AND
EASTERN CANADA. THE LOCAL AREA WAS IN AN AREA OF SUBSIDENCE BEHIND
A SYSTEM WHICH HAD MOVED INTO IOWA/ILLINOIS. WATER VAPOR IMAGERY
SHOWED THIS PATTERN...AND ALSO PICKED UP ON A SHORTWAVE TROUGH
OVER WESTERN WYOMING.
AT THE SURFACE...DEWPOINTS ACROSS THE FORECAST AREA RANGED FROM
THE 40S IN THE EASTERN PANHANDLE TO AROUND 70 AT KLBF.
OBSERVATIONS INDICATED A BOUNDARY FROM AROUND KIEN TO KOGA THROUGH
KMCK AND INTO NORTH CENTRAL KANSAS WITH EASTERLY WINDS ON THE EAST
SIDE OF THE BOUNDARY.
HOW TODAY/S WEATHER PANS OUT WILL DEPEND ON IF CONVECTION DEVELOPS
AHEAD OF THE WYOMING SHORTWAVE THIS MORNING. THE 30.00Z AND 30.06Z
NAM FIRE STORMS OVER THE PANHANDLE BETWEEN 12Z AND 15Z AND THE
RAPID REFRESH DOES SHOW SOME INDICATIONS OF CONVECTION IN THESE
AREAS...BUT THESE ARE THE ONLY MODELS TO DO SO. THE GFS/EC/GEM
ARE ALL DRY WHILE THE LATEST HRRR AND DOES DEVELOP STORMS...BUT
KEEPS THEM OVER SOUTH DAKOTA. ALTHOUGH THE NAM IS THE
OUTLIER...THERE IS ELEVATED INSTABILITY AND MOISTURE IN THE AREA
AND WITH THE WAVE MOVING ACROSS THE REGION...DON/T WANT TO
DISCOUNT ITS OUTPUT. THE ACTIVITY OVER WYOMING IS VERY HIGH BASED
/AROUND 11K FEET/. WILL ASSUME THAT TREND WILL CONTINUE WITH THE
MORNING HOURS BRINGING SOME SCATTERED RADAR RETURNS WITH NO
MEASURABLE RAIN TO THE NORTHWEST PART OF THE FORECAST AREA. THERE
COULD BE AN ISOLATED LIGHTNING STRIKES...AND COLLAPSING
SHOWERS/STORMS COULD CAUSE SOME GUSTY WINDS. FOR THE
AFTERNOON...PEAK HEATING...INSTABILITY AND A WEAK SHORTWAVE
PASSING SHOULD BE ENOUGH FOR STORMS TO DEVELOP. THESE STORMS TOO
WILL BE HIGH BASED AND WITH QUITE A BIT OF DRY AIR IN THE BOUNDARY
LAYER DON/T HAVE A LOT OF CONFIDENCE ON THE COVERAGE OF MEASURABLE
RAINFALL. WITH THESE CHANCES AND AS THE LOW LEVEL JET PICKS UP
THIS EVENING...KEPT CHANCES IN THE FORECAST AT THROUGH TONIGHT.
NOT A MAJOR THREAT FOR SEVERE STORMS AS THE WARMTH OF THE LAYER
ALOFT SHOULD PRECLUDE THE CHANCES FOR LARGE HAIL TO MAKE IT TO THE
GROUND. THERE IS 30 TO 45KTS OF DEEP LAYER SHEAR SO CAN/T DISCOUNT
AN ISOLATED ORGANIZED STORM BUT THINKING THE PRIMARY THREAT WILL
BE STRONG WINDS. DID DROP HIGH TEMPERATURES BY A FEW DEGREES TODAY
DUE MAINLY TO THE HIGHER CLOUD COVER EXPECTED. BUT IT WILL STILL
BE VERY WARM WITH HIGHS IN THE MID TO UPPER 90S MOST LOCATIONS.
THE UPPER LEVEL TROUGH OVER THE PACIFIC WILL MOVE ONSHORE
TONIGHT...WHICH WILL BEGIN TO AMPLIFY THE FLOW AGAIN WITH THE
RIDGE BUILDING NORTH ACROSS THE PLAINS THROUGH MONDAY. THE MODELS
ARE TRYING TO PUSH A SHORTWAVE TROUGH OVER THE RIDGE ACROSS
WYOMING AND SOUTH DAKOTA ON SUNDAY SO DEVELOP PRECIPITATION OVER
THE AREA. WARM AIR ALOFT MAY KEEP SOME OF THIS FROM HAPPENING SO
MAY HAVE HIGHER CHANCES OVER THE HIGHER TERRAIN BUT WILL KEEP A
SLIGHT CHANCE OVER THE NORTHEASTERN COUNTIES AS WELL. THEN MONDAY
WILL BE DRY AS NEBRASKA SITS RIGHT UNDER THE RIDGE. FOR
TEMPERATURES...FORECAST SOUNDINGS SHOWING FULL MIXING ON SUNDAY
AND MONDAY. DID TAKE INTO ACCOUNT HIGHER CLOUD COVER ESPECIALLY OVER
THE NORTHERN PARTS OF THE FORECAST AREA SUNDAY SO DIDN/T GO AS
WARM IN THE FORECAST IN THOSE AREAS. STILL EXPECTING MID TO
UPPER 90S THOUGH. MONDAY SHOULD BE A BIT WARMER WITH MUCH OF THE
AREA LOOKING TO BE INTO THE TRIPLE DIGITS AGAIN.
NO END IS IN SITE FOR THE WARMTH AS THE MODELS KEEP THE RIDGE IN
PLACE THROUGH THE REMAINDER OF NEXT WEEK. THIS LEADS TO LOW
CHANCES FOR RAIN AND HOT TEMPERATURES. HIGHS LOOK TO BE IN THE MID
TO UPPER 90S AND SOME DAYS HITTING 100 DEGREES OR BETTER. BY
FRIDAY EVENING THE RIDGE MAY SHIFT EAST FAR ENOUGH FOR STORMS
DEVELOPING OVER COLORADO AND WYOMING TO MOVE INTO THE EASTERN
PANHANDLE. BUT UNTIL THEN THE FORECAST LOOKS DRY FOR MUCH OF NEXT
WEEK.
FIRE WEATHER...
THE CURRENT FORECAST DOESN/T HAVE ANY DAYS WITH CONDITIONS
REACHING CRITICAL FIRE WEATHER CRITERIA. SUNDAY MAY BE CLOSE WITH
BREEZY SOUTHERLY WINDS AND RELATIVE HUMIDITY FORECAST BETWEEN 15
AND 20 PERCENT OVER SOUTHWEST NEBRASKA. WILL NEED TO CONTINUE TO
WATCH FOR FIRE POTENTIAL OVER THE NEXT WEEK AS THE HEAT AND DRY
WEATHER CONTINUE.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM/EXTENDED...BROOKS
AVIATION...SPRINGER
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1036 AM CDT SAT JUN 30 2012
.DISCUSSION...CLUSTER OF THUNDERSTORMS ACROSS THE EAST CENTRAL
WILL BE THE FOCUS FOR THE REMAINDER OF THE MORNING. HRRR MODEL
SUGGESTS AFTER THIS AREA EXITS THE REGION EARLY THIS AFTERNOON
SOME ADDITIONAL DEVELOPMENT ALONG THE SOUTH DAKOTA BORDER AND
ALONG THE NORTH CENTRAL. WILL KEEP AFTERNOON CHANCES GOING...
ALTHOUGH BY EARLY AFTERNOON MAY BE ABLE TO FURTHER REFINE. ITS
COOLER ACROSS THE CLOUDY AND RAIN AREAS ACROSS THE EAST
CENTRAL...BUT THIS LIKELY TO RECOVER AFTER CLOUDS CLEAR A BIT THIS
AFTERNOON.
&&
.AVIATION...AT 10 AM CDT...LOW PRESSURE ACROSS SOUTH DAKOTA WITH A
TROUGH EXTENDING NORTH INTO SASKATCHEWAN WILL MOVE EAST TODAY. THE
LOW WILL BE THE FOCUS FOR THUNDERSTORMS DURING THE AFTERNOON AND
EVENING CENTRAL AND EAST. VFR EXPECTED AT ALL TAF SITE THROUGH THE
12Z TAF. KJMS LIKELY TO SEE THUNDERSTORMS IN THE VICINITY THROUGH
18Z THEN AFTER 00Z. KDIK/KISN SHOULD REMAIN WEST OF THE THUNDERSTORM
THREAT. KBIS/KMOT WILL SEE THUNDERSTORMS VICINITY AFTER 00Z.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...WAA
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1005 AM EDT SAT JUN 30 2012
.SYNOPSIS...
A STATIONARY FRONT ACROSS CENTRAL OHIO WILL MEANDER NORTH AND
SOUTH TODAY AND TONIGHT. HIGH PRESSURE WILL MOVE ACROSS THE LOCAL
AREA SUNDAY FORCING THE FRONT SOUTH INTO THE LOWER OHIO VALLEY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SHOWERS HAVE MOVED INTO NE OH AND NW PA AND CONTINUE TO DISSIPATE.
HAVE BACKED OFF ON PRECIP CHANCES FOR THIS AFTERNOON. IT APPEARS
THAT THE CONVECTION OVER IL WILL PASS JUST TO THE SOUTH OF THE
AREA THIS AFTERNOON. WILL MAINTAIN A SMALL MENTION OF PRECIP THIS
AFTERNOON JUST IN CASE IT STAYS FURTHER N. CLOUDS OVERHEAD SHOULD
CONTINUE TO MOVE OUT AND EXPECTING A FAIR AMOUNT OF SUNSHINE THIS
AFTERNOON.
PREVIOUS...SATELLITE SHOWS MCS TO OUR WEST WITH RADAR SHOWING PRECIP ABOUT
TO MOVE INTO NWRN OHIO. HRRR SHOWS THIS ACTIVITY WEAKENING BUT
CONTINUING EAST ACROSS THE AREA THROUGH THE EARLY MORNING HOURS.
WILL HAVE LIKELY POPS FOR THE MORNING WEST BUT FOR NOW WILL HAVE
CHANCE POPS FURTHER EAST. MAY NEED TO INCREASE POPS FURTHER EAST
IF SYSTEM DOESN`T DISSIPATE OR PROPAGATE SOUTHEAST. DO EXPECT
CONVECTION TO WEAKEN/DISSIPATE BY MID MORNING AS THESE SYSTEMS
USUALLY DO. FOR THE AFTERNOON...WILL HAVE CHANCE POPS FOR THE
AREA. INSTABILITY DOES REACH INTO THE AREA BUT BEST VALUES
FORECAST TO BE TO THE SOUTH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
SUNDAY THROUGH TUESDAY MODELS SHOW A SLIGHT AMPLIFICATION OF THE
UPPER PATTERN WITH HEIGHTS BUILDING ACROSS THE NATIONS MIDSECTION
WHILE HEIGHTS FALL ACROSS THE CANADIAN AND NEW ENGLAND COAST.
INITIALLY SLIGHTLY COOLER AIR DROP INTO THE AREA TONIGHT AND
SUNDAY AS THE STATIONARY FRONT ACROSS CENTRAL OHIO SAGS SOUTH.
850MB TEMPS DROP FROM AROUND 20C TO 16C BY SUNDAY 12Z. AS HEIGHTS
BUILD IN THE PLAINS THE FRONT WILL RETURN WARM AND CROSS THE AREA
WITH THE GRADIENT INCREASING NORTHEAST OF THE AREA MONDAY INTO
TUESDAY AS THE TROF SAGS ALONG THE COAST. SHOULD GET A SLIGHT COOL
DOWN NORTHEAST QUARTER OF THE AREA SUNDAY WITH TEMPS REBOUNDING TO
THE UPPER 80S AND LOWER 90S MONDAY AND TUESDAY. WILL KEEP FORECAST
DRY SUNDAY AS HIGH PRESSURE BUILDS ACROSS THE AREA. MONDAY THE
WARM FRONT WILL MOVE BACK ACROSS THE AREA SO WILL HAVE LOW CHANCE
POPS. TUESDAY NIGHT WILL HAVE A LOW CHANCE POP NORTHEAST INVOF
BEST MOISTURE AND THE WARM FRONT.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
HERE WE GO AGAIN IN THIS UP AND DOWN SUMMER OF HEAT. UPPER LEVEL
PATTERN TRENDING TOWARD ANOTHER SURGE IN THE UPPER LEVEL RIDGE OVER
MUCH OF THE CENTRAL UNITED STATES. LARGE DOME OF HIGH PRESSURE
DEVELOPS OVER MISSOURI AND THIS MEANS STRONG SUBSIDENCE WILL
CONTINUE AND THEREFORE BRING BACK A RETURN TO HOT TEMPERATURES TO
THE FORECAST AREA. THE UPPER LEVEL HIGH PRESSURE CENTER SHIFTS EAST
ACROSS THE GREAT LAKES REGION BY FRIDAY MORNING.
A SERIES OF VORTICITY MAXIMUMS WILL ROTATE SOUTHEAST ON THE EAST
SIDE OF THE HIGH PRESSURE CENTER. THE VORTICITY MAXIMUMS WILL HAVE
SOME LIMITED MOISTURE ASSOCIATED WITH THEM AS THEY MOVE THROUGH THE
AREA WEDNESDAY AND THURSDAY. THEREFORE...WILL NEED TO KEEP THE
MENTION FOR SHOWERS AND THUNDERSTORMS GOING WEDNESDAY INTO THURSDAY.
AS UPPER LEVEL HIGH PRESSURE SETTLES IN OVER THE FORECAST AREA...SO
WILL THE SUBSEQUENT SURFACE HIGH PRESSURE. THIS WILL RESULT IN A
RETURN TO HOT DRY WEATHER LEADING INTO THE WEEKEND.
TEMPERATURES EXPECTED TO CLIMB INTO THE UPPER 80S TO LOWER 90S AGAIN
NEXT WEEK FOR HIGHS WITH 60S AND 70S FOR LOWS.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
FIRST NOTE IS FINDLAY SYSTEM IS OUT AND WILL NOT HAVE ASOS DATA FOR
AMENDMENTS. SO...HAD TO GO WITH AMENDMENT NOT SCHEDULED.
REMNANTS OF MCS MOVING EAST ACROSS THE AREA AT THIS TIME. A FEW
RUMBLES OF THUNDER EXPECTED ACROSS FINDLAY...MANSFIELD...AKRON
CANTON...AND YOUNGSTOWN THIS MORNING. LIGHTNING WITH THE FEATURE
IS VERY LIMITED AND SPORADIC AT THIS POINT. MAINLY EXPECTING A FEW
LIGHT RAIN SHOWERS WITH THE FEATURE.
VFR CONDITIONS EXPECTED FOR THE AFTERNOON INTO EARLY TONIGHT.
EXPECTING SOME MINOR FOG TO DEVELOP WHERE THE RAIN OCCURRED LAST
COUPLE DAYS SO WILL MENTION ACCORDINGLY IN THE TAFS.
WINDS EXPECTED TO BE GENERALLY LIGHT.
.OUTLOOK...VFR CONDITIONS WILL PREVAIL EXCEPT FOR A THREAT OF
SHOWERS/THUNDERSTORMS SUNDAY AND AGAIN ON MONDAY.
&&
.MARINE...
LAKE IS EXPECTED TO REMAIN QUIET THROUGH THE PERIOD. NO STRONG
GRADIENT CHANGES EXPECTED SO WINDS ARE NOT EXPECTED TO BECOME A
PROBLEM AT THIS TIME.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TK
NEAR TERM...KUBINA
SHORT TERM...TK
LONG TERM...LOMBARDY
AVIATION...LOMBARDY
MARINE...LOMBARDY
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
721 AM EDT SAT JUN 30 2012
.SYNOPSIS...
A STATIONARY FRONT ACROSS CENTRAL OHIO WILL MEANDER NORTH AND
SOUTH TODAY AND TONIGHT. HIGH PRESSURE WILL MOVE ACROSS THE LOCAL
AREA SUNDAY FORCING THE FRONT SOUTH INTO THE LOWER OHIO VALLEY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SATELLITE SHOWS MCS TO OUR WEST WITH RADAR SHOWING PRECIP ABOUT TO
MOVE INTO NWRN OHIO. HRRR SHOWS THIS ACTIVITY WEAKENING BUT CONTINUING
EAST ACROSS THE AREA THROUGH THE EARLY MORNING HOURS. WILL HAVE
LIKELY POPS FOR THE MORNING WEST BUT FOR NOW WILL HAVE CHANCE
POPS FURTHER EAST. MAY NEED TO INCREASE POPS FURTHER EAST IF
SYSTEM DOESN`T DISSIPATE OR PROPAGATE SOUTHEAST. DO EXPECT
CONVECTION TO WEAKEN/DISSIPATE BY MID MORNING AS THESE SYSTEMS
USUALLY DO. FOR THE AFTERNOON...WILL HAVE CHANCE POPS FOR THE
AREA. INSTABILITY DOES REACH INTO THE AREA BUT BEST VALUES
FORECAST TO BE TO THE SOUTH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
SUNDAY THROUGH TUESDAY MODELS SHOW A SLIGHT AMPLIFICATION OF THE
UPPER PATTERN WITH HEIGHTS BUILDING ACROSS THE NATIONS MIDSECTION
WHILE HEIGHTS FALL ACROSS THE CANADIAN AND NEW ENGLAND COAST.
INITIALLY SLIGHTLY COOLER AIR DROP INTO THE AREA TONIGHT AND
SUNDAY AS THE STATIONARY FRONT ACROSS CENTRAL OHIO SAGS SOUTH.
850MB TEMPS DROP FROM AROUND 20C TO 16C BY SUNDAY 12Z. AS HEIGHTS
BUILD IN THE PLAINS THE FRONT WILL RETURN WARM AND CROSS THE AREA
WITH THE GRADIENT INCREASING NORTHEAST OF THE AREA MONDAY INTO
TUESDAY AS THE TROF SAGS ALONG THE COAST. SHOULD GET A SLIGHT COOL
DOWN NORTHEAST QUARTER OF THE AREA SUNDAY WITH TEMPS REBOUNDING TO
THE UPPER 80S AND LOWER 90S MONDAY AND TUESDAY. WILL KEEP FORECAST
DRY SUNDAY AS HIGH PRESSURE BUILDS ACROSS THE AREA. MONDAY THE
WARM FRONT WILL MOVE BACK ACROSS THE AREA SO WILL HAVE LOW CHANCE
POPS. TUESDAY NIGHT WILL HAVE A LOW CHANCE POP NORTHEAST INVOF
BEST MOISTURE AND THE WARM FRONT.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
HERE WE GO AGAIN IN THIS UP AND DOWN SUMMER OF HEAT. UPPER LEVEL
PATTERN TRENDING TOWARD ANOTHER SURGE IN THE UPPER LEVEL RIDGE OVER
MUCH OF THE CENTRAL UNITED STATES. LARGE DOME OF HIGH PRESSURE
DEVELOPS OVER MISSOURI AND THIS MEANS STRONG SUBSIDENCE WILL
CONTINUE AND THEREFORE BRING BACK A RETURN TO HOT TEMPERATURES TO
THE FORECAST AREA. THE UPPER LEVEL HIGH PRESSURE CENTER SHIFTS EAST
ACROSS THE GREAT LAKES REGION BY FRIDAY MORNING.
A SERIES OF VORTICITY MAXIMUMS WILL ROTATE SOUTHEAST ON THE EAST
SIDE OF THE HIGH PRESSURE CENTER. THE VORTICITY MAXIMUMS WILL HAVE
SOME LIMITED MOISTURE ASSOCIATED WITH THEM AS THEY MOVE THROUGH THE
AREA WEDNESDAY AND THURSDAY. THEREFORE...WILL NEED TO KEEP THE
MENTION FOR SHOWERS AND THUNDERSTORMS GOING WEDNESDAY INTO THURSDAY.
AS UPPER LEVEL HIGH PRESSURE SETTLES IN OVER THE FORECAST AREA...SO
WILL THE SUBSEQUENT SURFACE HIGH PRESSURE. THIS WILL RESULT IN A
RETURN TO HOT DRY WEATHER LEADING INTO THE WEEKEND.
TEMPERATURES EXPECTED TO CLIMB INTO THE UPPER 80S TO LOWER 90S AGAIN
NEXT WEEK FOR HIGHS WITH 60S AND 70S FOR LOWS.
&&
.AVIATION /11Z SATURDAY THROUGH WEDNESDAY/...
FIRST NOTE IS FINDLAY SYSTEM IS OUT AND WILL NOT HAVE ASOS DATA FOR
AMENDMENTS. SO...HAD TO GO WITH AMENDMENT NOT SCHEDULED.
REMNANTS OF MCS MOVING EAST ACROSS THE AREA AT THIS TIME. A FEW
RUMBLES OF THUNDER EXPECTED ACROSS FINDLAY...MANSFIELD...AKRON
CANTON...AND YOUNGSTOWN THIS MORNING. LIGHTNING WITH THE FEATURE
IS VERY LIMITED AND SPORADIC AT THIS POINT. MAINLY EXPECTING A FEW
LIGHT RAIN SHOWERS WITH THE FEATURE.
VFR CONDITIONS EXPECTED FOR THE AFTERNOON INTO EARLY TONIGHT.
EXPECTING SOME MINOR FOG TO DEVELOP WHERE THE RAIN OCCURRED LAST
COUPLE DAYS SO WILL MENTION ACCORDINGLY IN THE TAFS.
WINDS EXPECTED TO BE GENERALLY LIGHT.
.OUTLOOK...VFR CONDITIONS WILL PREVAIL EXCEPT FOR A THREAT OF
SHOWERS/THUNDERSTORMS SUNDAY AND AGAIN ON MONDAY.
&&
.MARINE...
LAKE IS EXPECTED TO REMAIN QUIET THROUGH THE PERIOD. NO STRONG
GRADIENT CHANGES EXPECTED SO WINDS ARE NOT EXPECTED TO BECOME A
PROBLEM AT THIS TIME.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TK
NEAR TERM...TK
SHORT TERM...TK
LONG TERM...LOMBARDY
AVIATION...LOMBARDY
MARINE...LOMBARDY
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
1053 AM CDT SAT JUN 30 2012
.UPDATE...
CURRENT FORECAST LOOKS TO BE ON TRACK THIS MORNING. ONLY
ADJUSTMENTS MADE WERE TO EXPAND POPS IN TIME TO COVER LINGERING
ELEVATED CONVECTION ACROSS CENTRAL AND SOUTH CENTRAL SOUTH DAKOTA.
ALSO...THERE ARE STILL ISOLATED THUNDERSTORMS ACROSS SOUTHERN NORTH
DAKOTA THIS MORNING...AND ONE OR TWO COULD CLIP THE FAR NORTHEAST
CWA. OTHERWISE...TEMPERATURE FORECAST IS HOLDING WELL.
UNCERTAINTY STILL REMAINS WITH THE THUNDERSTORM POTENTIAL THIS
AFTERNOON. THERE IS LIMITED UPPER LEVEL SUPPORT...HOWEVER...THE
ATMOSPHERE WILL DESTABILIZE NICELY THIS AFTERNOON...AND LOOKS LIKE
THE BEST CHANCE FOR THUNDERSTORMS TO DEVELOP WILL BE ALONG THE
SURFACE INVERTED TROUGH DURING PEAK HEATING THIS AFTERNOON...THEN
SPREADING EAST.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH MONDAY
MAIN THUNDERSTORM CLUSTER THIS MORNING IS ROLLING EAST ACROSS
NORTH DAKOTA WITH QUIET CONDITIONS OVER SOUTH DAKOTA. YESTERDAY
MORNING THE HRRR HANDLED MORNING CONVECTION VERY WELL. THIS
MORNING...HRRR IS SHOWING ANOTHER CLUSTER OF STORMS DEVELOPING
ACROSS WESTERN SOUTH DAKOTA OVER THE NEXT FEW HOURS...THEN PUSHES
AN AREA OF SCATTERED SHOWERS ACROSS THE STATE THROUGH THE DAY.
ALTHOUGH...UNLIKE YESTERDAY THERE IS REALLY NO NOTEWORTHY UPPER
WAVE TO THE WEST TO IGNITE ANYTHING. THIS SAID...MODELS ARE
INITIALIZING A VORT MAXIMA OVER WYOMING AND THERE IS SOME ACCAS
DEVELOPMENT OVER SOUTHEAST WYOMING. NOTHING CURRENTLY OVER WESTERN
SOUTH DAKOTA AT THIS TIME. HRRR MAY BE OVERDOING THINGS THIS
MORNING BUT WILL MONITOR CLOSELY. CURRENTLY HAVE SLIGHT CHANCE
POPS UP THROUGH 12Z AND DRY CONDITIONS FOR THE MOST PART AFTER
THAT UNTIL LATER THIS AFTERNOON. IF ACCAS/PRECIP DEVELOPS OVER THE
WESTERN PART OF THE STATE BY 12Z...WILL HAVE TO RETHINK CURRENT
PRECIP FORECAST FOR THE AFTERNOON HOURS.
FOR LATER TODAY...FRONTAL BOUNDARY WILL APPROACH THE CENTRAL
DAKOTAS WITH MODERATE TO STRONG INSTABILITY DEVELOPING. 40 TO 50
KNOTS OF SHEAR AVAILABLE WITH THE HIGHEST VALUES OVER NORTHEAST
SOUTH DAKOTA INTO EASTERN NORTH DAKOTA. STRONGEST CAPPING IS
EVIDENT OVER THE NORTHEAST CWA THIS AFTERNOON...WITH WEAKEST
REGION FURTHER WEST NEAR THE FRONTAL BOUNDARY. HI RES MODELS
INDICATING SCT STORM DEVELOPMENT LATE THIS AFTERNOON/EARLY EVENING
ACROSS DIFFERENT PARTS OF THE REGION. CONVECTIVE TRENDS STILL
RATHER DIFFICULT TO NAIL DOWN TODAY THOUGH.
HOT AND HUMID CONDITIONS WILL CONTINUE THROUGH THE SHORT TERM
PERIOD...WITH THE HOTTEST TEMPS EXPECTED ON MONDAY. IMPRESSIVE
THERMAL RIDGE SETS UP RIGHT OVER THE AREA BY MONDAY AFTERNOON.
TEMPS WILL BE WELL INTO THE 90S WITH SOME AREAS AROUND 100
DEGREES. HUMIDITY WILL COME ALONG WITH THIS. COULD BE LOOKING AT
POSSIBLY HEAT ADVISORY HEADLINES IN THE NEXT DAY OR SO.
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY
THE UPPER LEVEL RIDGE WILL HOLD TIGHT OVER THE PLAINS THROUGH MOST
OF THE PERIOD. BY FRIDAY...IT GETS DAMPENED SOME AS A SHORTWAVE
TRACKS ACROSS THE DAKOTAS WITH THE FLOW BECOMING MORE ZONAL. THE
MODELS CONTINUE TO SHOW SPATTERINGS OF PRECIPITATION THROUGHOUT
THE ENTIRE PERIOD AS A SERIES OF FRONTAL BOUNDARIES TRACK ACROSS
THE PLAINS. BIGGEST HINDRANCE TO PRECIPITATION FORMATION WILL BE A
STRONG CAPPING INVERSION THAT WILL BE IN PLACE IN ASSOCIATION WITH
THE UPPER RIDGE. COOLER MID LEVEL TEMPERATURES MOVE IN ON FRIDAY
ALONG WITH THE AFOREMENTIONED UPPER SHORTWAVE. THEREFORE...LOOKS
AS THOUGH THE BEST CHANCE FOR PRECIPITATION WILL COME FRIDAY AND
FRIDAY NIGHT. WILL STICK CLOSE TO THE ALLBLEND SOLUTION...KEEPING
A SLIGHT CHANCE OF PRECIPITATION SOMEWHERE OVER THE CWA MONDAY
NIGHT THROUGH THURSDAY NIGHT...THEN WILL GO WITH CHANCE POPS AT
THE END OF THE PERIOD.
TEMPERATURES WILL BE VERY WARM THROUGH THE ENTIRE PERIOD UNDER THE
INFLUENCE OF THE RIDGE. H85 TEMPERATURES IN THE MID TO UPPER 20S
CELSIUS WILL TRANSLATE TO AFTERNOON HIGH TEMPERATURES IN THE 90S
AND OVERNIGHT LOW TEMPERATURES IN THE UPPER 60S TO MID 70S.
WEDNESDAY AND THURSDAY LOOK TO BE THE WARMEST DAYS...WITH PORTIONS
OF THE CENTRAL AND WESTERN CWA EXPECTED TO SEE MID TO UPPER
90S...WITH A FEW SPOTS LIKELY TO SEE 100+ DEGREE TEMPERATURES.
&&
.AVIATION...
12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
VFR CONDITIONS WILL PREVAIL ACROSS THE AREA TODAY. SOME LIGHT
FOG...GENERALLY AROUND 4SM...WILL LINGER ACROSS PORTIONS OF THE
EASTERN CWA THROUGH ABOUT 14Z...THEN WILL DISSIPATE. THERE IS A
POSSIBILITY THAT SHOWERS AND THUNDERSTORMS WILL DEVELOP LATER THIS
AFTERNOON...BUT COVERAGE IS EXPECTED TO BE ISOLATED...SO HAVE
OPTED TO LEAVE THE MENTION OUT OF THE TAFS FOR NOW.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...SERR
SHORT TERM...TMT
LONG TERM...PARKIN
AVIATION...PARKIN
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
631 AM CDT SAT JUN 30 2012
.UPDATE...
SEE UPDATED AVIATION DISCUSSION BELOW.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH MONDAY
MAIN THUNDERSTORM CLUSTER THIS MORNING IS ROLLING EAST ACROSS
NORTH DAKOTA WITH QUIET CONDITIONS OVER SOUTH DAKOTA. YESTERDAY
MORNING THE HRRR HANDLED MORNING CONVECTION VERY WELL. THIS
MORNING...HRRR IS SHOWING ANOTHER CLUSTER OF STORMS DEVELOPING
ACROSS WESTERN SOUTH DAKOTA OVER THE NEXT FEW HOURS...THEN PUSHES
AN AREA OF SCATTERED SHOWERS ACROSS THE STATE THROUGH THE DAY.
ALTHOUGH...UNLIKE YESTERDAY THERE IS REALLY NO NOTEWORTHY UPPER
WAVE TO THE WEST TO IGNITE ANYTHING. THIS SAID...MODELS ARE
INITIALIZING A VORT MAXIMA OVER WYOMING AND THERE IS SOME ACCAS
DEVELOPMENT OVER SOUTHEAST WYOMING. NOTHING CURRENTLY OVER WESTERN
SOUTH DAKOTA AT THIS TIME. HRRR MAY BE OVERDOING THINGS THIS
MORNING BUT WILL MONITOR CLOSELY. CURRENTLY HAVE SLIGHT CHANCE
POPS UP THROUGH 12Z AND DRY CONDITIONS FOR THE MOST PART AFTER
THAT UNTIL LATER THIS AFTERNOON. IF ACCAS/PRECIP DEVELOPS OVER THE
WESTERN PART OF THE STATE BY 12Z...WILL HAVE TO RETHINK CURRENT
PRECIP FORECAST FOR THE AFTERNOON HOURS.
FOR LATER TODAY...FRONTAL BOUNDARY WILL APPROACH THE CENTRAL
DAKOTAS WITH MODERATE TO STRONG INSTABILITY DEVELOPING. 40 TO 50
KNOTS OF SHEAR AVAILABLE WITH THE HIGHEST VALUES OVER NORTHEAST
SOUTH DAKOTA INTO EASTERN NORTH DAKOTA. STRONGEST CAPPING IS
EVIDENT OVER THE NORTHEAST CWA THIS AFTERNOON...WITH WEAKEST
REGION FURTHER WEST NEAR THE FRONTAL BOUNDARY. HI RES MODELS
INDICATING SCT STORM DEVELOPMENT LATE THIS AFTERNOON/EARLY EVENING
ACROSS DIFFERENT PARTS OF THE REGION. CONVECTIVE TRENDS STILL
RATHER DIFFICULT TO NAIL DOWN TODAY THOUGH.
HOT AND HUMID CONDITIONS WILL CONTINUE THROUGH THE SHORT TERM
PERIOD...WITH THE HOTTEST TEMPS EXPECTED ON MONDAY. IMPRESSIVE
THERMAL RIDGE SETS UP RIGHT OVER THE AREA BY MONDAY AFTERNOON.
TEMPS WILL BE WELL INTO THE 90S WITH SOME AREAS AROUND 100
DEGREES. HUMIDITY WILL COME ALONG WITH THIS. COULD BE LOOKING AT
POSSIBLY HEAT ADVISORY HEADLINES IN THE NEXT DAY OR SO.
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY
THE UPPER LEVEL RIDGE WILL HOLD TIGHT OVER THE PLAINS THROUGH MOST
OF THE PERIOD. BY FRIDAY...IT GETS DAMPENED SOME AS A SHORTWAVE
TRACKS ACROSS THE DAKOTAS WITH THE FLOW BECOMING MORE ZONAL. THE
MODELS CONTINUE TO SHOW SPATTERINGS OF PRECIPITATION THROUGHOUT
THE ENTIRE PERIOD AS A SERIES OF FRONTAL BOUNDARIES TRACK ACROSS
THE PLAINS. BIGGEST HINDRANCE TO PRECIPITATION FORMATION WILL BE A
STRONG CAPPING INVERSION THAT WILL BE IN PLACE IN ASSOCIATION WITH
THE UPPER RIDGE. COOLER MID LEVEL TEMPERATURES MOVE IN ON FRIDAY
ALONG WITH THE AFOREMENTIONED UPPER SHORTWAVE. THEREFORE...LOOKS
AS THOUGH THE BEST CHANCE FOR PRECIPITATION WILL COME FRIDAY AND
FRIDAY NIGHT. WILL STICK CLOSE TO THE ALLBLEND SOLUTION...KEEPING
A SLIGHT CHANCE OF PRECIPITATION SOMEWHERE OVER THE CWA MONDAY
NIGHT THROUGH THURSDAY NIGHT...THEN WILL GO WITH CHANCE POPS AT
THE END OF THE PERIOD.
TEMPERATURES WILL BE VERY WARM THROUGH THE ENTIRE PERIOD UNDER THE
INFLUENCE OF THE RIDGE. H85 TEMPERATURES IN THE MID TO UPPER 20S
CELSIUS WILL TRANSLATE TO AFTERNOON HIGH TEMPERATURES IN THE 90S
AND OVERNIGHT LOW TEMPERATURES IN THE UPPER 60S TO MID 70S.
WEDNESDAY AND THURSDAY LOOK TO BE THE WARMEST DAYS...WITH PORTIONS
OF THE CENTRAL AND WESTERN CWA EXPECTED TO SEE MID TO UPPER
90S...WITH A FEW SPOTS LIKELY TO SEE 100+ DEGREE TEMPERATURES.
&&
.AVIATION...
12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
VFR CONDITIONS WILL PREVAIL ACROSS THE AREA TODAY. SOME LIGHT
FOG...GENERALLY AROUND 4SM...WILL LINGER ACROSS PORTIONS OF THE
EASTERN CWA THROUGH ABOUT 14Z...THEN WILL DISSIPATE. THERE IS A
POSSIBILITY THAT SHOWERS AND THUNDERSTORMS WILL DEVELOP LATER THIS
AFTERNOON...BUT COVERAGE IS EXPECTED TO BE ISOLATED...SO HAVE
OPTED TO LEAVE THE MENTION OUT OF THE TAFS FOR NOW.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
SHORT TERM...TMT
LONG TERM...PARKIN
AVIATION...PARKIN
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
626 AM CDT SAT JUN 30 2012
.AVIATION...
VFR CONDITIONS EXPECTED THROUGHOUT THE TAF PERIOD. ISOLATED
-SHRA/-TSRA EXPECTED TO DEVELOP WEST OF BOTH TERMINALS THIS
AFTERNOON/EVENING. CURRENT THINKING IS THAT THE PRECIP ACTIVITY
WILL NEAR EITHER TERMINAL /ESPECIALLY KCDS/...AND THUS NOT ENOUGH
CONFIDENCE TO ADD A MENTION ATTM. WILL OF COURSE AMEND AS
NECESSARY.
&&
.PREV DISCUSSION... /ISSUED 314 AM CDT SAT JUN 30 2012/
SHORT TERM...
UA HIGH PRESSURE MAXIMA LOCATED ACROSS ARIZONA/NEW MEXICO AND THE
SERN CONUS...IN ADDITION TO A CONTINUAL WESTWARD RETROGRADING UA LOW
ACROSS SERN TEXAS...WAS THE SYNOPTIC SETUP THIS MORNING...AND WILL
PERSIST THROUGH THE SHORT TERM PERIOD. AS SUCH...A GENERAL WEAKNESS
IN THE HEIGHT FIELDS WILL EXIST FOR THE SOUTHERN PLAINS...WHICH WILL
ALLOW FOR TEMPS TO BE NOTABLY COOLER THAN YESTERDAY...ALBEIT STILL
WARM WITH A TEMP RANGE OF 95-101 ANTICIPATED.
THE SYNOPTIC PATTERN HAS ALLOWED FOR THE MONSOONAL MOISTURE TO SHIFT
SOUTH AND EAST ACROSS THE SOUTHERN PLAINS...OR BASICALLY EAST OF THE
UA RIDGE THAT IS ACROSS ARIZONA/NEW MEXICO. A SFC TROUGH NORTH OF
THE REGION COMBINED WITH THIS MONSOONAL MOISTURE HAS RESULTED IN
SCATTERED SHOWERS AND AN ISOLATED THUNDERSTORM OR TWO THAT DEVELOPED
ACROSS THE SOUTHWESTERN TEXAS PANHANDLE YESTERDAY EVENING...AND PER
0730Z RADAR ANALYSIS IS NOW MOVING SSE ACROSS YOAKUM AND TERRY
COUNTIES /AT LEAST WHAT IS LEFT OF IT/. IT IS OF NOTE TO ALSO
MENTION A LINE OF SHOWERS AND THUNDERSTORMS THAT HAVE DEVELOPED FROM
EASTERN LYNN TO NORTHEASTERN CROSBY COUNTY...COINCIDING WITH BETTER
DEWPOINTS....AND A SOUTHEASTWARD MOVING OUTFLOW BOUNDARY THAT HAS
INDUCED ADDITIONAL LIGHT ECHOES ACROSS FLOYD AND MOTLEY COUNTIES.
WOULD NOT BE OUT OF THE QUESTION FOR SOME LOCATIONS WITHIN THE LINE
OF HEAVIEST SHOWERS AND THUNDERSTORMS TO ACCUMULATE A FEW TENTHS OF
AN INCH OF RAINFALL...FOR THE MERE FACT OF TRAINING OCCURRING. THE
LINE OF STORMS WAS MOVING TO THE SW ACROSS THE PERMIAN BASIN WHICH
IS INDICATIVE OF THE UA RIDGE/S INFLUENCE. THE RUC SOLUTION IS BEST
HANDLING THE ADDITIONAL PRECIP DEVELOPMENT ALBEIT...A BIT MORE
AGGRESSIVE IN REGARD TO COVERAGE. HOWEVER THE RUC DOES SHOW PRECIP
DISSIPATED BY AOA 15Z AND HAVE THEREFORE ADDED SLIGHT CHANCE POPS
ACROSS THE SAID AREAS UNTIL 15Z.
FORECAST SOLUTIONS HINT AT THE MONSOONAL MOISTURE PERSISTING ACROSS
THE WESTERN PANHANDLES AND THE WESTERN SOUTH PLAINS TODAY. A SFC
TROUGH NNW OF THE FA AND A CONTINUED EASTERLY UPSLOPE REGIME WILL
LEAD TO THE LOGICAL CONCLUSION OF A REPEAT SCENARIO OF STORMS
DEVELOPING ACROSS THE WESTERN PANHANDLES...EASTERN NEW MEXICO AND
WESTERN SOUTH THIS AFTERNOON/EVENING. A CAPPING INVERSION IS NOTED
OFF THE CAPROCK...BUT THAT IS NOT THE CASE ON THE CAPROCK...AS
STEEPENED LAPSE RATES WITH LITTLE TO NO CIN IS EXHIBITED BY MODEL
SOUNDINGS. FURTHERMORE...THE SFC-BASED CAPE IS A LITTLE BETTER TODAY
THAN YESTERDAY /AOA 700 J/KG/ WITH PROGGED 0-6 KM BULK SHEAR OF 25
KTS /SIMILAR TO YESTERDAY/. THERE ARE SLIGHT HINTS OF A WEAKNESS OF
MID LEVEL WINDS WHICH IS EVIDENT OF THE UA RIDGE REMAINING AN
INFLUENCE. A MITIGATING FACTOR THAT STANDS OUT IS THAT THE
STEERING FLOW WILL BE FROM THE NORTHEAST...WHICH COULD AID TO
PREVENT STORMS FROM STAYING IN THE CWA FOR LONG PERIODS OF TIME.
HOWEVER...THE AFOREMENTIONED INDICES CAN NOT BE IGNORED WHERE AN
ISOLATED STRONG THUNDERSTORM WITH LCL/S AOA 10KFT SUGGEST THE MAIN
THREAT TO BE GUSTY WINDS. WILL THEREFORE CONTINUE A SLIGHT CHANCE
MENTION ACROSS THE WEST AND NW ZONES THIS AFTERNOON THROUGH TONIGHT.
LONG TERM...
NO SIG CHANGES MADE TO THE LONG TERM PORTION OF THE FCST. UPPER
LEVEL INVERTED TROUGH TO MOVE ACROSS WEST CENTRAL TEXAS SUNDAY
WITH POTENTIAL FOR SOME ISOLATED SHRA OR TSRA MAKING IT INTO THE
SERN ZONES...ALTHOUGH CHANCES STILL LOOK TOO SMALL TO MENTION IN
THE FCST ATTM. AS THE TROUGH CONTINUES TO MOVE WWD THE CENTER OF
THE UPPER RIDGE WILL RETROGRADE TAKING DEEPER MOISTURE WITH IT
MINIMIZING RAIN CHANCES ACROSS THE WRN ZONES SUNDAY. ON THE
POSITIVE SIDE...FURTHER DECREASES IN HEIGHTS AND THICKNESSES WILL
TRANSLATE INTO COOLER TEMPERATURES AGAIN SUNDAY...MAINLY LOWER TO
MIDDLE 90S.
EARLY IN THE WEEK THE WRN PORTION OF THE UPPER RIDGE THAT WILL BE
DOMINATING MUCH OF THE CONUS WILL BEGIN TO EXPAND NEWD TOWARD THE
CENTRAL PLAINS. FCST AREA WILL REMAIN ON THE SOUTH OR SOUTHEAST
FLANK OF THE CENTER WITH RELATIVELY WEAKER HEIGHTS AND EASTERLY
FLOW IN PLACE ACROSS THE REGION. MAY SEE THE DEEPER MONSOONAL EDGE
BACK TO THE EAST BY THE END OF THE WEEK...ALTHOUGH TOO EARLY TO
MENTION ANY RAIN POTENTIAL. PATTERN SHOULD HELP THE AREA AVOID THE
EXTREME HEAT OF EARLIER THIS WEEK...ALTHOUGH WILL CONTINUE TO RUN
ABOVE SEASONAL NORMALS THROUGH THE FCST PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 96 65 91 63 90 / 20 20 10 10 0
TULIA 95 67 90 66 89 / 20 20 0 0 0
PLAINVIEW 95 68 91 67 90 / 10 10 0 0 0
LEVELLAND 96 68 91 66 92 / 20 10 0 0 0
LUBBOCK 97 69 92 68 92 / 10 10 10 10 0
DENVER CITY 96 68 91 66 90 / 20 10 10 10 0
BROWNFIELD 97 69 91 67 91 / 20 10 10 10 0
CHILDRESS 100 71 96 70 95 / 10 0 0 0 10
SPUR 98 70 93 71 92 / 10 0 10 10 10
ASPERMONT 100 71 95 70 96 / 10 0 10 10 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
29
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
350 PM MST SAT JUN 30 2012
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER THE AREA THIS WEEKEND WITH DECREASING
CHANCES OF SHOWERS AND THUNDERSTORMS...BUT A CONTINUATION OF THE
ABOVE NORMAL TEMPERATURES. A RETURN TO A MORE TYPICAL MONSOON
PATTERN IS IN STORE NEXT WEEK AS AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS ARE POSSIBLE MONDAY THROUGH THE END OF NEXT WEEK.
&&
.DISCUSSION...
LATEST SATELLITE PICS SHOW AN MCV NEAR PUERTO PENASCO...WHICH
CONTINUES TO DISSIPATE THIS AFTERNOON. GLOBAL MODELS HAVE FAILED TO
INITIALIZE THIS FEATURE...THOUGH HIGHER RESOLUTION MODELS SUCH AS
THE WRF AND RAP HAVE INDEED CAPTURED THE PRESENCE OF THE VORT. ONLY
SOME CLOUDINESS IS EXPECTED TONIGHT ACROSS WESTERN AZ AS THE SYSTEM
MOVES NORTHWARD AND CONTINUES TO WEAKEN. OTHERWISE...FLOW GENERALLY
REMAINS OUT OF THE SOUTH AND SOUTHWEST AROUND THE ANTICYCLONE
POSITIONED ALONG THE AZ/NM BORDER. CONVECTION HAS BEEN CONFINED TO
EASTERN AZ AND POPS ACROSS THE FORECAST REMAIN NEGLIGIBLE THROUGH
SUNDAY. MAIN STORY WILL CONTINUE TO BE THE ABOVE NORMAL
TEMPERATURES. LATEST GUIDANCE HAS COME IN ROUGHLY A DEGREE COOLER
FOR SUNDAY AND THIS IS REFLECTED IN THE OFFICIAL FORECAST.
NEVERTHELESS...THE EXCESSIVE HEAT WARNING WILL REMAIN IN EFFECT
THROUGH SUNDAY EVENING.
WELL DEFINED PV ANOMALY CURRENTLY LOCATED NEAR THE RIO GRANDE VALLEY
WILL CONTINUE MOVING STEADILY WESTWARD AND THEN NORTHWARD TOWARDS
SONORA EARLY NEXT WEEK. THIS WILL RESULT IN A SHARP INCREASE IN
LOW-LEVEL MIXING RATIOS MON-TUE ACROSS AZ ASSOCIATED WITH THE
ANOMALOUSLY STRONG SOUTHEASTERLY FLOW. POPS WERE INCREASED
CONSIDERABLY FROM PHOENIX SOUTH AND EASTWARD...PARTICULARLY ACROSS
PINAL COUNTY...TUE AFTERNOON AND EVENING WHEN MOISTURE TRANSPORT AND
THETA-E LAPSE RATES ARE MAXIMIZED. AT THE VERY LEAST...BLOWING DUST
FROM THUNDERSTORMS NEAR TUCSON APPEARS LIKELY...AND THIS WAS
INSERTED INTO THE FORECAST FOR PINAL COUNTY. INVERTED TROUGH IS
EXPECTED TO REACH SOUTH-CENTRAL AZ WED...THOUGH THE CONVECTION MAY
BE SOMEWHAT INHIBITED BY COOLER BOUNDARY LAYER TEMPERATURES IF
THUNDERSTORMS DO MATERIALIZE TUESDAY EVENING.
MODELS BEGIN TO DIVERGE BY THU...WITH THE ECMWF CONSIDERABLY MORE
MOIST THAN THE GFS. THIS RESULTS IN CONVECTIVE FEEDBACK WHICH FUELS
ADDITIONAL DEVELOPMENT EACH AFTERNOON THROUGH AT LEAST SAT. EVEN THE
MORE CONSERVATIVE GFS SHOULD BE SUFFICIENTLY MOIST FOR ISOLATED TO
SCATTERED THUNDERSTORMS EACH DAY THROUGH THE EXTENDED AND POPS WERE
INCREASED THROUGH THE PERIOD. TEMPERATURES WILL BOTTOM OUT
WED-THU...FOLLOWED BY A GRADUAL WARMING TREND INTO NEXT WEEKEND.
&&
.AVIATION...
SOUTHEAST CALIFORNIA...SOUTHWEST AND SOUTH CENTRAL ARIZONA INCLUDING
KIPL...KBLH...KPHX...KIWA AND KSDL...
MOSTLY CLEAR SKIES AND LIGHT WINDS UNDER 10KT AT ALL TAF SITES
THROUGH AT LEAST 00Z MONDAY/2 JULY. SOME LOCAL GUSTS UP TO 20KT ARE
POSSIBLE THIS AFTERNOON NEAR KPHX/KIWA/KBLH...ESPECIALLY LATER THIS
EVENING NEAR KIPL...SETTLING DOWN BY MIDNIGHT.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
HIGH PRESSURE WILL RESIDE EAST OF THE AREA NEXT WEEK...WITH A
GRADUAL INCREASE IN MOISTURE AND CHANCES FOR WETTING RAIN FOR MOST
OF SOUTH-CENTRAL ARIZONA. MODEL CONSENSUS SUGGESTS THAT THE DEEPER
MOISTURE MAY NOT MAKE A WESTWARD PUSH INTO SOUTHEAST CALIFORNIA AND
JOSHUA TREE NATIONAL PARK. SO...THE LOWER DESERTS WEST OF THE
COLORADO RIVER MAY REMAIN QUITE DRY OTHER THAN SHOWING SOME
IMPROVEMENT IN DAYTIME HUMIDITY LEVELS AND RECOVERY. WINDS WILL BE
LIGHT OVERALL...BUT STRONG AND GUSTY NEAR THUNDERSTORMS. REMEMBER
THAT STRONG OUTFLOW WINDS HAVE THE POTENTIAL TO TRAVEL CONSIDERABLE
DISTANCES ACROSS THE LOWER DESERTS.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...EXCESSIVE HEAT WARNING UNTIL 8 PM MST SUNDAY
AZZ022-023-027-028.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH
AVIATION...MEYERS
FIRE WEATHER...MEYERS
AREA FORECAST DISCUSSION
NWS NEW YORK NY
601 PM EDT SAT JUN 30 2012
.SYNOPSIS...
A WEAK COLD FRONT REMAINS NEAR THE AREA TONIGHT AND WILL MOVE
WITHIN THE REGION ON SUNDAY. THIS FRONT MOVES FURTHER AWAY AND
OFFSHORE ON SUNDAY NIGHT. WEAK HIGH PRESSURE SETTLES OVER THE
REGION FROM MONDAY THROUGH TUESDAY. A WARM FRONT APPROACHES FROM
THE SOUTHWEST TUESDAY NIGHT...THEN LIFTS THROUGH THE REGION
WEDNESDAY MORNING...FOLLOWED BY A COLD FRONT MOVING THROUGH THE
TRI-STATE FROM LATE WEDNESDAY INTO THURSDAY MORNING. WEAK HIGH
PRESSURE THEN BUILDS IN THROUGH FRIDAY NIGHT. A COLD FRONT THEN
APPROACHES FROM THE NORTH ON SATURDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
IN THE NEAR TERM GOING INTO THIS EVENING...SEA BREEZE INTRODUCING
AT LEAST 10 DEGREE HIGHER DEWPOINTS FROM THE OCEAN. WITH THE HEAT
ADVISORY KEPT AS IS WITH THE THINKING THAT THERE WOULD BE SOME
SPOTS AWAY FROM THE COAST LIKE INTERIOR PORTIONS OF THE CITY THAT
WOULD BE COOLING A FEW DEGREES BUT WOULD HAVE A HIGHER JUMP WITH
THE DEWPOINTS WITH THE SEA BREEZE COMING IN THAT WOULD RESULT IN
HEAT INDICES OF NEAR 95 DEGREES. DESPITE THIS BEING
MARGINAL...THERE HAVE BEEN SOME MESONET OBSERVATIONS COMING IN
PARTS OF THE CITY WITH A TEMP/DEWPOINT COMBINATION RESULTING IN
HEAT INDICES OF 95 TO 99 DEGREES THIS AFTERNOON...BUT MOST OBS
HAVE BEEN STAYING MORE IN THE 90-95 DEGREE HEAT INDEX RANGE. THESE
SHOULD ALL BE ON A LOWERING TREND BY 21-23Z.
MAIN UPPER LEVEL JET NEAR 250 MB STAYS TO THE NORTH OF THE REGION
TONIGHT WITH SOME SLIGHT INCREASE IN WINDS LATE TONIGHT INTO SUNDAY
MORNING. A SECOND 500MB PERTURBATION APPROACHES LATE TONIGHT INTO
SUNDAY MORNING WITHIN THE QUASI-ZONAL FLOW ALOFT BUT ITS PVA IS OF
LESS MAGNITUDE THAN THE ONE MOVING IN THIS EVENING. THE STRONGER ONE
THIS EVENING WILL KEEP A SLIGHT CHANCE OF A SHOWER OR THUNDERSTORM
MAINLY FOR WESTERN PORTIONS OF THE FORECAST REGION.
THIS IS TAKING INTO ACCOUNT THE BETTER PERFORMANCE OF THE GFS AND
SREF WITH RESPECT TO THE MCS TO THE SOUTH OF THE REGION LAST NIGHT.
THIS WAS USED IN COMBINATION WITH THE HRRR FOR THE PRECIP FORECAST.
WITH THE LACK OF QPF SIGNAL FROM THE MODEL PRECIP FIELDS...JUST LEFT
AS A SLIGHT CHANCE OF A SHOWER OR THUNDERSTORM. WITHOUT MUCH FORCING
ALOFT...THIS CONVECTION WOULD DISSIPATE LATER THIS EVENING WITH THE
LOSS OF HEATING AND HENCE CAPE.
AT THE SURFACE...A FRONTAL BOUNDARY TO THE SOUTH OF THE REGION WILL
SLOWLY LIFT BACK NORTH TOWARDS THE AREA TONIGHT. THE FRONTAL
BOUNDARY WITHOUT MUCH SUPPORT ALOFT WILL KEEP COVERAGE OF ANY
SHOWERS OR THUNDERSTORMS LOW. BEST LOW LEVEL THETA-E ADVECTION STAYS
SOUTH OF THE REGION.
A MODEL BLEND OF MAV AND MET GUIDANCE WAS CHOSEN FOR LOWS WHICH WILL
VARY FROM THE 70S NEAR THE CITY TO THE 60S ELSEWHERE.
THERE IS A MODERATE RISK OF RIP CURRENTS AT THE OCEAN BEACHES
INTO EARLY THIS EVENING.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
FOR SUNDAY...THE SURFACE FRONTAL BOUNDARY WILL BE WITHIN THE
REGION. SFC FLOW OUT OF THE WEST AND WEST NORTHWEST WILL BE
TURNING MORE SOUTHWEST AT THE COASTLINE DURING THE AFTERNOON WITH
SEA BREEZE INFLUENCE. THE SYNOPTIC FORCING WILL BE LOWERING AS A
PARENT LOW ASSOCIATED WITH THIS FRONT WILL BE FILLING IN WITHIN
SOUTHEAST CANADA. USED HIGH TEMPS FROM THE WARMER MET GUIDANCE
WITH MORE WEIGHT THAN THE MAV GUIDANCE. WITH FORECAST DEWPOINTS
ARE A LITTLE HIGHER THAN TODAY AND VERY WARM BUT SLIGHTLY LOWER
HIGH TEMPS...HEAT INDICES WILL ONCE AGAIN MAX OUT NEAR 95 DEGREES
SO KEPT THE HEAT ADVISORY FOR THE CITY.
WENT WITH A CHANCE SHOWERS AND THUNDERSTORMS WITH THE INCREASE IN
DIURNAL INSTABILITY DURING THE DAY...WITH BETTER CHANCES FOR THE
INTERIOR SECTIONS. THERE IS A CHANCE OF GUSTY WINDS AND SMALL HAIL
WITH SOME THUNDERSTORMS AND POSSIBLY STRONGER WITH BETTER BULK SHEAR
OF ABOUT 30-35 KT WITH UPPER LEVEL TROUGH DEEPENING OVER THE AREA.
SPC HAS THE REGION IN A 5 PERCENT RISK OF SEVERE WEATHER.
A STRONG UPPER LEVEL JET IS SHOWN LATE SUNDAY NIGHT INTO MONDAY OF
75-80 KT APPROACHES THE REGION FROM THE WEST. A LONGER WAVELENGTH
SHORTWAVE AXIS MOVES EAST OF THE REGION INTO MONDAY MORNING WITH
FLOW TURNING MORE NORTHERLY. THERE ARE MORE SIGNIFICANT HEIGHT FALLS
RELATIVELY SPEAKING OF 20-30M. THIS WILL BE ENOUGH TO PUSH THE FRONT
FARTHER OFFSHORE AND MARK A SLIGHT COOLING TREND. MAV/MET BLEND USED
FOR LOWS SUNDAY NIGHT.
THERE IS A MODERATE RISK OF RIP CURRENTS FOR THE EASTERN SUFFOLK
COUNTY OCEAN BEACHES ON SUNDAY.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
700-500 HPA TROUGH AXIS PUSHES THROUGH THE AREA MONDAY - WITH A
SLIGHT CHANCE OF SHRA/TSTMS IN THE AFTERNOON/EARLY EVENING. RIDGING
BUILDS INTO THE REGION ALOFT MONDAY NIGHT-TUESDAY NIGHT...KEEPING
THINGS BASICALLY DRY - THOUGH DO HAVE SLIGHT CHANCE POPS LATE
TUESDAY NIGHT AHEAD OF AN APPROACHING WARM FRONT.
A NORTHERN STREAM SHORTWAVE APPROACHES WEDNESDAY MORNING...THEN
PUSHES THROUGH THE REGION WEDNESDAY AFTERNOON/EVENING - WITH CHANCE
POPS FOR SHRA/TSTMS WITH ITS PASSAGE. RIDGING THEN BUILDS BACK IN
ALOFT FROM LATE WEDNESDAY NIGHT THROUGH FRIDAY NIGHT - WITH DRY BUT
INCREASINGLY WARM-HOT CONDITIONS ACROSS THE REGION. ANOTHER NORTHERN
STREAM SHORTWAVE APPROACHES SATURDAY - WITH SLIGHT CHANCE POPS AHEAD
OF IT.
FOR TEMPERATURES MONDAY-SATURDAY...
USED A BLEND OF MIXING DOWN FROM 725 HPA - COMPROMISE BETWEEN NAM
BUFKIT SOUNDINGS SUGGESTING MIXING DOWN FROM 650 HPA AND GFS BUFKIT
SOUNDINGS LIMITING MIXING TO AROUND 800 HPA - WITH NAM 2-METER
TEMPERATURES...MAV/MET GUIDANCE AND BIAS CORRECTED MOS GUIDE. THE
RESULT IS HIGHS AROUND 5 DEGREES ABOVE NORMAL. DEWPOINTS IN THE
UPPER 50S WILL KEEP HEAT INDICES AT OR BELOW THE AIR TEMPERATURE.
FOR LOWS MONDAY NIGHT...USED A BLEND OF MAV/MET GUIDANCE WITH BIAS
CORRECTED MAV GUIDANCE - YIELDING VALUES A FEW DEGREES ABOVE NORMAL.
BLENDED MEX/MEX ENSEMBLE MEAN/ECMWF EXTENDED GUIDANCE WITH A MIX
DOWN FROM 800 HPA FOR HIGHS ON TUESDAY - WITH VALUES AROUND 5
DEGREES ABOVE NORMAL.
FROM TUESDAY NIGHT-SATURDAY BLENDED MEX/MEX ENSEMBLE MEAN/ECMWF
EXTENDED GUIDANCE WITH HPC GUIDANCE. EXPECT TEMPERATURES TO RUN A
FEW DEGREES ABOVE NORMAL TUESDAY NIGHT-THURSDAY NIGHT...THEN AROUND
5 DEGREES ABOVE NORMAL FRIDAY-SATURDAY. DEWPOINTS ARE FORECAST TO
REMAIN RELATIVELY LOW...SO HEAT INDICES SHOULD NOT GET MUCH ABOVE
THE AIR TEMPERATURE UNTIL MAYBE SATURDAY.
&&
.AVIATION /22Z SATURDAY THROUGH THURSDAY/...
HIGH CONFIDENCE VFR THROUGH THE PERIOD. CONVECTION UNLIKELY AS
PATCH OF BKN/OVC MID LEVEL CLOUDS MOVES ACROSS AND LIMITS
INSTABILITY.
COASTAL SEA BREEZE UNLIKELY TO REACH KLGA WHERE W WINDS HAVE BEEN
GUSTING JUST SHY OF 20 KT. THAT SAID...THERE COULD BACK WSW INTO
EARLY EVENING.
GENERALLY LIGHT FLOW TONIGHT SHOULD BECOME W-NW 5-10 KT AFTER
12Z-13Z SUNDAY...THEN GIVE WAY TO SEA BREEZES AT
COASTAL TERMINALS.
OUTLOOK FOR 18Z SUNDAY THROUGH THURSDAY...GENERALLY VFR.
ONLY SLIGHT CHANCE OF TSTMS EACH DAY EXCEPT TUE.
&&
.MARINE...
WAVEWATCH GUIDANCE WAS RUNNING ABOUT 1 FOOT TOO HIGH...SO LOWERED
THIS BY A FOOT IN THE NEAR TERM. GENERALLY EXPECTING SUB SCA
CONDITIONS THROUGH SUNDAY NIGHT WITH A LACK OF ANY STRONG PRESSURE
GRADIENT IN PLACE.
WITH A RELATIVELY LIGHT PRESSURE GRADIENT FORECAST OVER THE REGION -
WINDS AND SEAS ARE FORECAST TO REMAIN BELOW SCA LEVELS FROM
MONDAY-THURSDAY. IN GENERAL WINDS ARE FORECAST TO REMAIN AT OR BELOW
10 KT THROUGH THE PERIOD...WITH THE POSSIBLE EXCEPTION OF AN
AFTERNOON/EVENING SEA BREEZE IN THE NY BIGHT REGION TUESDAY.
&&
.HYDROLOGY...
NOT A LOT OF QPF IS FORECAST...WITH TOTAL BASIN AVERAGE RAINFALL
LESS THEN 1/10 INCH THROUGH SUNDAY NIGHT. LOCALIZED HEAVY RAIN
IS A POSSIBILITY THOUGH WITH ANY THUNDERSTORMS THAT DO DEVELOP AS
PW WILL BE NEAR 1.3 INCHES.
NO SIGNIFICANT RAINFALL IS EXPECTED MONDAY-TUESDAY NIGHT.
THERE IS THE POTENTIAL FOR TSTMS ON WED. BASIN AVERAGE QPF LIKELY
WILL BE LESS THAN A 1/2 AN INCH...WITH LOCALIZED HEAVIER RAINFALL
POSSIBLE UNDER ANY STRONGER CONVECTION.
&&
.CLIMATE...
HERE ARE THE RECORD HIGHS AND FORECAST TEMPS FOR SUNDAY JULY 1:
.LOCATION..........FORECAST HIGH...RECORD HIGH...YEAR
.CENTRAL PARK NY.........94............100.......1901
.LAGUARDIA NY............97.............97.......1964
.KENNEDY NY..............91............102.......1963
.NEWARK NJ...............97............100.......1963
.ISLIP NY................92.............87.......2001
.BRIDGEPORT CT...........92.............95.......1963
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR NYZ072>075-176-
178.
HEAT ADVISORY FROM NOON TO 7 PM EDT SUNDAY FOR NYZ072>075-176-
178.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MALOIT/JM
NEAR TERM...JM
SHORT TERM...JM
LONG TERM...MALOIT
AVIATION...GOODMAN/MET
MARINE...MALOIT/JM
HYDROLOGY...MALOIT/JM
CLIMATE...
AREA FORECAST DISCUSSION...CORRECTED
NWS NEW YORK NY
408 PM EDT SAT JUN 30 2012
.SYNOPSIS...
A WEAK COLD FRONT REMAINS NEAR THE AREA TONIGHT AND WILL MOVE
WITHIN THE REGION ON SUNDAY. THIS FRONT MOVES FURTHER AWAY AND
OFFSHORE ON SUNDAY NIGHT. WEAK HIGH PRESSURE SETTLES OVER THE
REGION FROM MONDAY THROUGH TUESDAY. A WARM FRONT APPROACHES FROM
THE SOUTHWEST TUESDAY NIGHT...THEN LIFTS THROUGH THE REGION
WEDNESDAY MORNING...FOLLOWED BY A COLD FRONT MOVING THROUGH THE
TRI-STATE FROM LATE WEDNESDAY INTO THURSDAY MORNING. WEAK HIGH
PRESSURE THEN BUILDS IN THROUGH FRIDAY NIGHT. A COLD FRONT THEN
APPROACHES FROM THE NORTH ON SATURDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
IN THE NEAR TERM GOING INTO THIS EVENING...SEA BREEZE INTRODUCING AT
LEAST 10 DEGREE HIGHER DEWPOINTS FROM THE OCEAN. WITH THE HEAT
ADVISORY KEPT AS IS WITH THE THINKING THAT THERE WOULD BE SOME SPOTS
AWAY FROM THE COAST LIKE INTERIOR PORTIONS OF THE CITY THAT WOULD BE
COOLING A FEW DEGREES BUT WOULD HAVE A HIGHER JUMP WITH THE
DEWPOINTS WITH THE SEA BREEZE COMING IN THAT WOULD RESULT IN HEAT
INDICES OF NEAR 95 DEGREES. DESPITE THIS BEING MARGINAL...THERE HAVE
BEEN SOME MESONET OBSERVATIONS COMING IN PARTS OF THE CITY WITH A
TEMP/DEWPOINT COMBINATION RESULTING IN HEAT INDICES OF 95 TO 99
DEGREES THIS AFTERNOON...BUT MOST OBS HAVE BEEN STAYING MORE IN THE
90-95 DEGREE HEAT INDEX RANGE. THESE SHOULD ALL BE ON A LOWERING
TREND BY 21-23Z.
MAIN UPPER LEVEL JET NEAR 250 MB STAYS TO THE NORTH OF THE REGION
TONIGHT WITH SOME SLIGHT INCREASE IN WINDS LATE TONIGHT INTO SUNDAY
MORNING. A SECOND 500MB PERTURBATION APPROACHES LATE TONIGHT INTO
SUNDAY MORNING WITHIN THE QUASI-ZONAL FLOW ALOFT BUT ITS PVA IS OF
LESS MAGNITUDE THAN THE ONE MOVING IN THIS EVENING. THE STRONGER ONE
THIS EVENING WILL KEEP A SLIGHT CHANCE OF A SHOWER OR THUNDERSTORM
MAINLY FOR WESTERN PORTIONS OF THE FORECAST REGION.
THIS IS TAKING INTO ACCOUNT THE BETTER PERFORMANCE OF THE GFS AND
SREF WITH RESPECT TO THE MCS TO THE SOUTH OF THE REGION LAST NIGHT.
THIS WAS USED IN COMBINATION WITH THE HRRR FOR THE PRECIP FORECAST.
WITH THE LACK OF QPF SIGNAL FROM THE MODEL PRECIP FIELDS...JUST LEFT
AS A SLIGHT CHANCE OF A SHOWER OR THUNDERSTORM. WITHOUT MUCH FORCING
ALOFT...THIS CONVECTION WOULD DISSIPATE LATER THIS EVENING WITH THE
LOSS OF HEATING AND HENCE CAPE.
AT THE SURFACE...A FRONTAL BOUNDARY TO THE SOUTH OF THE REGION WILL
SLOWLY LIFT BACK NORTH TOWARDS THE AREA TONIGHT. THE FRONTAL
BOUNDARY WITHOUT MUCH SUPPORT ALOFT WILL KEEP COVERAGE OF ANY
SHOWERS OR THUNDERSTORMS LOW. BEST LOW LEVEL THETA-E ADVECTION STAYS
SOUTH OF THE REGION.
A MODEL BLEND OF MAV AND MET GUIDANCE WAS CHOSEN FOR LOWS WHICH WILL
VARY FROM THE 70S NEAR THE CITY TO THE 60S ELSEWHERE.
THERE IS A MODERATE RISK OF RIP CURRENTS AT THE OCEAN BEACHES
INTO EARLY THIS EVENING.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
FOR SUNDAY...THE SURFACE FRONTAL BOUNDARY WILL BE WITHIN THE REGION.
SFC FLOW OUT OF THE WEST AND WEST NORTHWEST WILL BE TURNING MORE
SOUTHWEST AT THE COASTLINE DURING THE AFTERNOON WITH SEA BREEZE
INFLUENCE. THE SYNOPTIC FORCING WILL BE LOWERING AS A PARENT LOW
ASSOCIATED WITH THIS FRONT WILL BE FILLING IN WITHIN SOUTHEAST
CANADA. USED HIGH TEMPS FROM THE WARMER MET GUIDANCE WITH MORE
WEIGHT THAN THE MAV GUIDANCE. WITH FORECAST DEWPOINTS ARE A LITTLE
HIGHER THAN TODAY AND VERY WARM BUT SLIGHTLY LOWER HIGH TEMPS...HEAT
INDICES WILL ONCE AGAIN MAX OUT NEAR 95 DEGREES SO KEPT THE HEAT
ADVISORY FOR THE CITY.
WENT WITH A CHANCE SHOWERS AND THUNDERSTORMS WITH THE INCREASE IN
DIURNAL INSTABILITY DURING THE DAY...WITH BETTER CHANCES FOR THE
INTERIOR SECTIONS. THERE IS A CHANCE OF GUSTY WINDS AND SMALL HAIL
WITH SOME THUNDERSTORMS AND POSSIBLY STRONGER WITH BETTER BULK SHEAR
OF ABOUT 30-35 KT WITH UPPER LEVEL TROUGH DEEPENING OVER THE AREA.
SPC HAS THE REGION IN A 5 PERCENT RISK OF SEVERE WEATHER.
A STRONG UPPER LEVEL JET IS SHOWN LATE SUNDAY NIGHT INTO MONDAY OF
75-80 KT APPROACHES THE REGION FROM THE WEST. A LONGER WAVELENGTH
SHORTWAVE AXIS MOVES EAST OF THE REGION INTO MONDAY MORNING WITH
FLOW TURNING MORE NORTHERLY. THERE ARE MORE SIGNIFICANT HEIGHT FALLS
RELATIVELY SPEAKING OF 20-30M. THIS WILL BE ENOUGH TO PUSH THE FRONT
FARTHER OFFSHORE AND MARK A SLIGHT COOLING TREND. MAV/MET BLEND USED
FOR LOWS SUNDAY NIGHT.
THERE IS A MODERATE RISK OF RIP CURRENTS FOR EASTERN SUFFOLK
COUNTY OCEAN BEACHES ON SUNDAY.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
700-500 HPA TROUGH AXIS PUSHES THROUGH THE AREA MONDAY - WITH A
SLIGHT CHANCE OF SHRA/TSTMS IN THE AFTERNOON/EARLY EVENING. RIDGING
BUILDS INTO THE REGION ALOFT MONDAY NIGHT-TUESDAY NIGHT...KEEPING
THINGS BASICALLY DRY - THOUGH DO HAVE SLIGHT CHANCE POPS LATE
TUESDAY NIGHT AHEAD OF AN APPROACHING WARM FRONT.
A NORTHERN STREAM SHORTWAVE APPROACHES WEDNESDAY MORNING...THEN
PUSHES THROUGH THE REGION WEDNESDAY AFTERNOON/EVENING - WITH CHANCE
POPS FOR SHRA/TSTMS WITH ITS PASSAGE. RIDGING THEN BUILDS BACK IN
ALOFT FROM LATE WEDNESDAY NIGHT THROUGH FRIDAY NIGHT - WITH DRY BUT
INCREASINGLY WARM-HOT CONDITIONS ACROSS THE REGION. ANOTHER NORTHERN
STREAM SHORTWAVE APPROACHES SATURDAY - WITH SLIGHT CHANCE POPS AHEAD
OF IT.
FOR TEMPERATURES MONDAY-SATURDAY...
USED A BLEND OF MIXING DOWN FROM 725 HPA - COMPROMISE BETWEEN NAM
BUFKIT SOUNDINGS SUGGESTING MIXING DOWN FROM 650 HPA AND GFS BUFKIT
SOUNDINGS LIMITING MIXING TO AROUND 800 HPA - WITH NAM 2-METER
TEMPERATURES...MAV/MET GUIDANCE AND BIAS CORRECTED MOS GUIDE. THE
RESULT IS HIGHS AROUND 5 DEGREES ABOVE NORMAL. DEWPOINTS IN THE
UPPER 50S WILL KEEP HEAT INDICES AT OR BELOW THE AIR TEMPERATURE.
FOR LOWS MONDAY NIGHT...USED A BLEND OF MAV/MET GUIDANCE WITH BIAS
CORRECTED MAV GUIDANCE - YIELDING VALUES A FEW DEGREES ABOVE NORMAL.
BLENDED MEX/MEX ENSEMBLE MEAN/ECMWF EXTENDED GUIDANCE WITH A MIX
DOWN FROM 800 HPA FOR HIGHS ON TUESDAY - WITH VALUES AROUND 5
DEGREES ABOVE NORMAL.
FROM TUESDAY NIGHT-SATURDAY BLENDED MEX/MEX ENSEMBLE MEAN/ECWMF
EXTENDED GUIDANCE WITH HPC GUIDANCE. EXPECT TEMPERATURES TO RUN A
FEW DEGREES ABOVE NORMAL TUESDAY NIGHT-THURSDAY NIGHT...THEN AROUND
5 DEGREES ABOVE NORMAL FRIDAY-SATURDAY. DEWPOINTS ARE FORECAST TO
REMAIN RELATIVELY LOW...SO HEAT INDICES SHOULD NOT GET MUCH ABOVE
THE AIR TEMPERATURE UNTIL MAYBE SATURDAY.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
VFR THROUGH THE TAF PERIOD.
WINDS GENERALLY FROM THE WEST TO SOUTHWEST UP TO 15 KT WITH
OCCASIONAL GUSTS AS HIGH AS 20 KT POSSIBLE THIS AFTERNOON. A SEA
BREEZE HAD DEVELOPED ALONG THE CONNECTICUT COAST AROUND 16Z...AND A
SEA BREEZE IS BEGINNING TO DEVELOP ALONG THE SOUTH SHORE OF LONG
ISLAND AT 17Z. WINDS AT KJFK A LITTLE DIFFICULT WITH THE TROUGH IN
THE VICINITY AND THE SEA BREEZE DEVELOPING...AND HAVE LOW TO
MODERATE CONFIDENCE WITH THE TIMING OF THE WIND SHIFT.
CONVECTION NOT EXPECTED AT THE TERMINALS...HOWEVER...CONVECTION IS
POSSIBLE LATE THIS AFTERNOON INTO THE EARLY EVENING JUST SOUTH OF
THE AREA. DO NOT EXPECT CONVECTION TO DEVELOP THIS FAR NORTH.
TONIGHT...WINDS BECOME LIGHT AND VARIABLE MOST TERMINALS...REMAINING
WESTERLY AT THE NYC METRO TERMINALS. SEA BREEZES LIKELY AGAIN
SUNDAY LATE MORNING INTO THE AFTERNOON.
AMENDMENTS MAY BE NEEDED TODAY FOR TIMING OF WIND SHIFTS.
OUTLOOK FOR 18Z SUNDAY THROUGH THURSDAY...
.SUNDAY-TUESDAY...GENERALLY VFR. ISOLATED AFTERNOON TSTMS POSSIBLE
SUNDAY AND MONDAY.
.WEDNESDAY AND THURSDAY...VFR. SLIGHT CHANCE OF TSTMS.
&&
.MARINE...
WAVEWATCH GUIDANCE WAS RUNNING ABOUT 1 FOOT TOO HIGH...SO LOWERED
THIS BY A FOOT IN THE NEAR TERM. GENERALLY EXPECTING SUB SCA
CONDITIONS THROUGH SUNDAY NIGHT WITH A LACK OF ANY STRONG PRESSURE
GRADIENT IN PLACE.
WITH A RELATIVELY LIGHT PRESSURE GRADIENT FORECAST OVER THE REGION -
WINDS AND SEAS ARE FORECAST TO REMAIN BELOW SCA LEVELS FROM
MONDAY-THURSDAY. IN GENERAL WINDS ARE FORECAST TO REMAIN AT OR BELOW
10 KT THROUGH THE PERIOD...WITH THE POSSIBLE EXCEPTION OF AN
AFTERNOON/EVENING SEA BREEZE IN THE NY BIGHT REGION TUESDAY.
&&
.HYDROLOGY...
NOT A LOT OF QPF IS FORECAST WITH TOTAL BASIN AVERAGED RAINFALL
AMOUNTS OF LESS THAN A TENTH OF AN INCH THROUGH SUNDAY NIGHT.
LOCALIZED HEAVY RAIN IS A POSSIBILITY THOUGH WITH SOME
THUNDERSTORMS AS PWATS WILL BE NEAR 1.3 INCHES BUT EXPECT THIS TO
BE ISOLATED.
NO SIGNIFICANT RAINFALL IS EXPECTED MONDAY-TUESDAY NIGHT. THERE
IS THE POTENTIAL FOR SHRA/TSTMS ON WEDNESDAY...BASIN AVERAGE QPF
LIKELY WILL BE LESS THAN A 1/2 AN INCH - HOWEVER LOCALIZED HEAVY
RAINFALL IS POSSIBLE UNDER ANY STRONGER CONVECTION.
&&
.CLIMATE...
HERE ARE THE RECORD HIGHS AND FORECAST TEMPS FOR SUNDAY JULY 1:
..LOCATION........FORECAST HIGH.......RECORD HIGH.......YEAR....
CENTRAL PARK NY.........94................100...........1901....
LAGUARDIA NY............97.................97...........1964....
KENNEDY NY..............91................102...........1963....
NEWARK NJ...............97................100...........1963....
ISLIP NY................92.................87...........2001....
BRIDGEPORT CT...........92.................95...........1963....
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR NYZ072>075-176-
178.
HEAT ADVISORY FROM NOON TO 7 PM EDT SUNDAY FOR NYZ072>075-176-
178.
NJ...MARINE...NONE.
&&
$$
SYNOPSIS...MALOIT/JM
NEAR TERM...JM
SHORT TERM...JM
LONG TERM...MALOIT
AVIATION...MET
MARINE...MALOIT/JM
HYDROLOGY...MALOIT/JM
CLIMATE...
AREA FORECAST DISCUSSION
NWS NEW YORK NY
146 PM EDT SAT JUN 30 2012
.SYNOPSIS...
A WEAK COLD FRONT SETTLES JUST TO THE SOUTH TODAY...AND REMAINS
NEARLY STATIONARY JUST TO THE SOUTH THIS WEEKEND. HIGH PRESSURE
BUILDS TO THE NORTH MONDAY AND TUESDAY. A WARM FRONT MOVES THROUGH
WEDNESDAY FOLLOWED BY A COLD FRONT LATE WEDNESDAY OR EARLY THURSDAY.
HIGH PRESSURE BUILDS TO END THE UPCOMING WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPPER LEVEL PATTERN OF THE RIDGE TO THE SOUTH AND A TROUGH OVER SE
CANADA WILL BE IN PLACE TODAY. A SURFACE FRONTAL BOUNDARY IS
CURRENTLY TO THE SOUTH OF THE REGION...ALLOWING FOR MORE OF A
WESTERLY FLOW AND THEREFORE DRIER AIR TO SETTLE INTO THE AREA.
WARMER AIR FROM VERTICAL MIXING UP TO AROUND 800 MB EXPECTED TO
RESULT IN ANOTHER HOT BUT SLIGHTLY DRIER DAY WITH HIGHS WELL INTO
THE 90S FOR MANY LOCATIONS. NOT MUCH CHANGE WITH MAX TEMPS IN
PREVIOUS FORECAST...JUST SLIGHT ADJUSTMENTS UP A DEGREE IN A FEW
SPOTS. DEWPOINTS IN THE 50S HAVE OVERSPREAD THE AREA WITH
NORTHWESTERLY TO WESTERLY WINDS. BY MID TO LATE AFTERNOON...STILL
EXPECTING HEAT INDICES IN THE MID 90S SO WILL KEEP HEAT ADVISORY
FOR NEW YORK CITY FOR THIS AFTERNOON ESPECIALLY FOR SOUTHERN
LOCATIONS ONCE THE SEA BREEZE STARTS TO MOVE IN AND BRINGS IN
SLIGHTLY HIGHER DEWPOINTS AND SPOTS WHERE VERTICAL MIXING IS NOT
AS EFFICIENT. HOWEVER...QUITE A FEW LOCATIONS COULD END UP HAVING
HEAT INDICES JUST BEING IN THE LOWER 90S.
WITH AN EMBEDDED SHORTWAVE WITHIN THE QUASI-ZONAL FLOW ALOFT MOVING
NEAR THE REGION BY THIS EVENING AS CONVEYED BY SOME PVA...THIS
WILL PROBABLY LIFT THE FRONTAL BOUNDARY BACK CLOSER TO THE AREA.
INCREASED CLOUDS THIS AFTERNOON AND KEPT THE SLIGHT CHANCE FOR
SHOWERS AND THUNDERSTORMS FOR LATE AFTERNOON INTO THE EARLY
EVENING FOR WESTERN LOCATIONS DESPITE THE LACK OF QPF SIGNAL FROM
THE NAM AND GFS WITH THEIR LAST RUNS. HRRR IS STARTING TO PICK UP
ON THIS CONVECTION TOWARDS THE LATE AFTERNOON. INSTABILITY IS
ALREADY STARTING TO BUILD...WITH VALUES OF CAPE VALUES BETWEEN 200
AND 700 J/KG FOR WESTERN AREAS OF THE FORECAST REGION THIS
MORNING. THIS WILL PROBABLY INCREASE TO AROUND 1000 J/KG AT LEAST
FOR SOME LOCATIONS THIS AFTERNOON.
THERE IS A MODERATE RISK OF RIP CURRENTS AT THE OCEAN BEACHES
TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
A GENERAL TROUGH OVER THE NORTHEAST REMAINS IN PLACE THIS TIME
FRAME. AT THE SFC...WEAK FRONTAL BOUNDARY SHOULD REMAIN JUST SOUTH.
IN SPITE OF THE SLIGHTLY LOWER HEIGHTS...STILL QUITE WARM TO HOT
CONDITIONS EXPECTED.
FOR TONIGHT...POSSIBLE MCS PASSES EITHER JUST SOUTH...OR HAS A
BIGGER IMPACT ON THE AREA. PLEASE SEE NEAR TERM SECTION FOR MORE ON
THIS POSSIBILITY...AND THE QUESTIONS THAT REMAIN.
OTHERWISE...FORECAST REMAINS DRY...WITH POSSIBLE CONVECTION DURING
THE DAY SUNDAY AGAIN. HOWEVER...COVERAGE SHOULD BE LOW...AND POPS
WILL FOLLOW SUIT.
AGAIN...WARMER THAN NORMAL TEMPS THIS TIME FRAME...WITH 60S TO 70S
AT NIGHT...AND 80S TO LOWER/MID 90S SUNDAY. HEAT ADVISORIES REMAIN
UP FOR NYC.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
SUNDAY NIGHT THROUGH TUESDAY...LOOK FOR GRADUAL COOLING AND
DRYING WITH THE LOWEST TEMPS AND HUMIDITIES OCCURRING DURING TUE. AN
ISOLATED SHOWER OR TSTM CANNOT BE RULED OUT MONDAY AFTERNOON BASED
ON SFC AND LOW LVL BASED INSTABILITY.
TUESDAY NIGHT THROUGH EARLY THURSDAY...THIS APPEARS TO BE AN
UNSETTLED PERIOD.
A WARM FRONT IS FORECAST TO DEVELOP AND MOVE NORTHEAST TOWARD THE
REGION AS A COLD FRONT TRAILING FROM A LOW PRESSURE SYSTEM MOVING
ACROSS SOUTHEAST CANADA MOVES ACROSS THE REGION.
WEST AND NW WIND FLOW ALOFT CONTINUES AS A HIGH AMPLITUDE RIDGE
MOVES EAST TOWARD THE WESTERN GREAT LAKES. THIS WILL SET THE STAGE
FOR A SERIES OF MCS MOVING SE DOWN THE RIDGE. IN A MOIST MARITIME
TROPICAL AIR MASS...HEAVY SHOWERS AND TSTMS ARE POSSIBLE. BECAUSE
OF HIGH FCST UNCERTAINTY...ONLY 20 PCT POP IS IN THE FCST FOR NOW.
STAY TUNED.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
VFR THROUGH THE TAF PERIOD.
WINDS GENERALLY FROM THE WEST TO SOUTHWEST UP TO 15 KT WITH
OCCASIONAL GUSTS AS HIGH AS 20 KT POSSIBLE THIS AFTERNOON. A SEA
BREEZE HAD DEVELOPED ALONG THE CONNECTICUT COAST AROUND 16Z...AND A
SEA BREEZE IS BEGINNING TO DEVELOP ALONG THE SOUTH SHORE OF LONG
ISLAND AT 17Z. WINDS AT KJFK A LITTLE DIFFICULT WITH THE TROUGH IN
THE VICINITY AND THE SEA BREEZE DEVELOPING...AND HAVE LOW TO
MODERATE CONFIDENCE WITH THE TIMING OF THE WIND SHIFT.
CONVECTION NOT EXPECTED AT THE TERMINALS...HOWEVER...CONVECTION IS
POSSIBLE LATE THIS AFTERNOON INTO THE EARLY EVENING JUST SOUTH OF
THE AREA. DO NOT EXPECT CONVECTION TO DEVELOP THIS FAR NORTH.
TONIGHT...WINDS BECOME LIGHT AND VARIABLE MOST TERMINALS...REMAINING
WESTERLY AT THE NYC METRO TERMINALS. SEA BREEZES LIKELY AGAIN
SUNDAY LATE MORNING INTO THE AFTERNOON.
AMENDMENTS MAY BE NEEDED TODAY FOR TIMING OF WIND SHIFTS.
OUTLOOK FOR 18Z SUNDAY THROUGH THURSDAY...
.SUNDAY-TUESDAY...GENERALLY VFR. ISOLATED AFTERNOON TSTMS POSSIBLE
SUNDAY AND MONDAY.
.WEDNESDAY AND THURSDAY...VFR. SLIGHT CHANCE OF TSTMS.
&&
.MARINE...
WINDS AND SEAS ARE GENERALLY EXPECTED TO REMAIN BELOW SCA LEVELS
THROUGH SUNDAY...ALTHOUGH SWELL FROM WHAT IS LEFTOVER FROM DEBBY
WILL LIKELY MAINTAIN OCEAN SEAS IN THE 3 TO 4 RANGE. COULD SEE
BRIEF 5 FOOTERS TODAY OVER THE OCEAN ZONES.
NEXT WEEK...WINDS AND SEAS ARE FORECAST TO REMAIN BELOW SMALL CRAFT
ADVISORY LIMITS OF 25 KT AND 5 FT.
&&
.HYDROLOGY...
DRY THIS MORNING. THERE IS A LOW PROBABILITY FOR DOWNPOURS
CAPABLE OF CAUSING MINOR URBAN/POOR DRAINAGE FLOODING LATE TODAY
AND TONIGHT. A FLASH FLOOD THREAT COULD UNFOLD IF AN MCS WORKS
INTO THE REGION...BUT PROBABILITY OF OCCURRENCE AT THIS TIME IS
LOW.
&&
.CLIMATE...
HERE ARE THE RECORD HIGHS AND FORECAST TEMPS FOR SATURDAY JUNE 30:
..LOCATION........FORECAST HIGH.......RECORD HIGH.......YEAR....
CENTRAL PARK NY.........93.................99...........1964....
LAGUARDIA NY............95.................97...........1964....
KENNEDY NY..............94.................99...........1964....
NEWARK NJ...............99.................99...........1964....
ISLIP NY................92.................89...........2001....
BRIDGEPORT CT...........92.................94...........1959....
HERE ARE THE RECORD HIGHS AND FORECAST TEMPS FOR SUNDAY JULY 1:
..LOCATION........FORECAST HIGH.......RECORD HIGH.......YEAR....
CENTRAL PARK NY.........94................100...........1901....
LAGUARDIA NY............96.................97...........1964....
KENNEDY NY..............93................102...........1963....
NEWARK NJ...............96................100...........1963....
ISLIP NY................91.................87...........2001....
BRIDGEPORT CT...........90.................95...........1963....
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR NYZ072>075-176-
178.
HEAT ADVISORY FROM NOON TO 7 PM EDT SUNDAY FOR NYZ072>075-176-
178.
NJ...MARINE...NONE.
&&
$$
SYNOPSIS...PW
NEAR TERM...JM
SHORT TERM...PW
LONG TERM...PW
AVIATION...MET
MARINE...BC
HYDROLOGY...PW
CLIMATE...
AREA FORECAST DISCUSSION
NWS NEW YORK NY
130 PM EDT SAT JUN 30 2012
.SYNOPSIS...
A WEAK COLD FRONT SETTLES JUST TO THE SOUTH TODAY...AND REMAINS
NEARLY STATIONARY JUST TO THE SOUTH THIS WEEKEND. HIGH PRESSURE
BUILDS TO THE NORTH MONDAY AND TUESDAY. A WARM FRONT MOVES THROUGH
WEDNESDAY FOLLOWED BY A COLD FRONT LATE WEDNESDAY OR EARLY THURSDAY.
HIGH PRESSURE BUILDS TO END THE UPCOMING WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPPER LEVEL PATTERN OF THE RIDGE TO THE SOUTH AND A TROUGH OVER SE
CANADA WILL BE IN PLACE TODAY. A SURFACE FRONTAL BOUNDARY IS
CURRENTLY TO THE SOUTH OF THE REGION...ALLOWING FOR MORE OF A
WESTERLY FLOW AND THEREFORE DRIER AIR TO SETTLE INTO THE AREA.
WARMER AIR FROM VERTICAL MIXING UP TO AROUND 800 MB EXPECTED TO
RESULT IN ANOTHER HOT BUT SLIGHTLY DRIER DAY WITH HIGHS WELL INTO
THE 90S FOR MANY LOCATIONS. NOT MUCH CHANGE WITH MAX TEMPS IN
PREVIOUS FORECAST...JUST SLIGHT ADJUSTMENTS UP AND DOWN A DEGREE
IN A FEW SPOTS. DEWPOINTS WERE ADJUSTED SLIGHTLY DOWN NEXT FEW
HOURS BUT STILL EXPECTING HEAT INDICES IN THE MID TO UPPER 90S SO
WILL KEEP HEAT ADVISORY FOR NEW YORK CITY FOR THIS AFTERNOON
ESPECIALLY FOR SOUTHERN LOCATIONS ONCE THE SEA BREEZE STARTS TO
MOVE IN AND BRINGS IN SLIGHTLY HIGHER DEWPOINTS.
WITH AN EMBEDDED SHORTWAVE WITHIN THE QUASI-ZONAL FLOW ALOFT MOVING
NEAR THE REGION BY THIS EVENING AS CONVEYED BY SOME PVA...THIS
WILL PROBABLY LIFT THE FRONTAL BOUNDARY BACK CLOSER TO THE AREA.
INCREASED CLOUDS THIS AFTERNOON AND KEPT THE SLIGHT CHANCE FOR
SHOWERS AND THUNDERSTORMS FOR LATE AFTERNOON INTO THE EARLY
EVENING FOR WESTERN LOCATIONS DESPITE THE LACK OF QPF SIGNAL FROM
THE NAM AND GFS WITH THEIR LAST RUNS. HRRR IS STARTING TO PICK UP
ON THIS CONVECTION TOWARDS THE LATE AFTERNOON. INSTABILITY IS
ALREADY STARTING TO BUILD...WITH VALUES OF CAPE VALUES BETWEEN 200
AND 700 J/KG FOR WESTERN AREAS OF THE FORECAST REGION THIS
MORNING. THIS WILL PROBABLY INCREASE TO AROUND 1000 J/KG AT LEAST
FOR SOME LOCATIONS THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
A GENERAL TROUGH OVER THE NORTHEAST REMAINS IN PLACE THIS TIME
FRAME. AT THE SFC...WEAK FRONTAL BOUNDARY SHOULD REMAIN JUST SOUTH.
IN SPITE OF THE SLIGHTLY LOWER HEIGHTS...STILL QUITE WARM TO HOT
CONDITIONS EXPECTED.
FOR TONIGHT...POSSIBLE MCS PASSES EITHER JUST SOUTH...OR HAS A
BIGGER IMPACT ON THE AREA. PLEASE SEE NEAR TERM SECTION FOR MORE ON
THIS POSSIBILITY...AND THE QUESTIONS THAT REMAIN.
OTHERWISE...FORECAST REMAINS DRY...WITH POSSIBLE CONVECTION DURING
THE DAY SUNDAY AGAIN. HOWEVER...COVERAGE SHOULD BE LOW...AND POPS
WILL FOLLOW SUIT.
AGAIN...WARMER THAN NORMAL TEMPS THIS TIME FRAME...WITH 60S TO 70S
AT NIGHT...AND 80S TO LOWER/MID 90S SUNDAY. HEAT ADVISORIES REMAIN
UP FOR NYC.
THERE IS A MODERATE RISK OF RIP CURRENTS AT THE OCEAN BEACHES
TODAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
SUNDAY NIGHT THROUGH TUESDAY...LOOK FOR GRADUAL COOLING AND
DRYING WITH THE LOWEST TEMPS AND HUMIDITIES OCCURRING DURING TUE. AN
ISOLATED SHOWER OR TSTM CANNOT BE RULED OUT MONDAY AFTERNOON BASED
ON SFC AND LOW LVL BASED INSTABILITY.
TUESDAY NIGHT THROUGH EARLY THURSDAY...THIS APPEARS TO BE AN
UNSETTLED PERIOD.
A WARM FRONT IS FORECAST TO DEVELOP AND MOVE NORTHEAST TOWARD THE
REGION AS A COLD FRONT TRAILING FROM A LOW PRESSURE SYSTEM MOVING
ACROSS SOUTHEAST CANADA MOVES ACROSS THE REGION.
WEST AND NW WIND FLOW ALOFT CONTINUES AS A HIGH AMPLITUDE RIDGE
MOVES EAST TOWARD THE WESTERN GREAT LAKES. THIS WILL SET THE STAGE
FOR A SERIES OF MCS MOVING SE DOWN THE RIDGE. IN A MOIST MARITIME
TROPICAL AIR MASS...HEAVY SHOWERS AND TSTMS ARE POSSIBLE. BECAUSE
OF HIGH FCST UNCERTAINTY...ONLY 20 PCT POP IS IN THE FCST FOR NOW.
STAY TUNED.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
VFR THROUGH THE TAF PERIOD.
WINDS GENERALLY FROM THE WEST TO SOUTHWEST UP TO 15 KT WITH
OCCASIONAL GUSTS AS HIGH AS 20 KT POSSIBLE THIS AFTERNOON. A SEA
BREEZE HAD DEVELOPED ALONG THE CONNECTICUT COAST AROUND 16Z...AND A
SEA BREEZE IS BEGINNING TO DEVELOP ALONG THE SOUTH SHORE OF LONG
ISLAND AT 17Z. WINDS AT KJFK A LITTLE DIFFICULT WITH THE TROUGH IN
THE VICINITY AND THE SEA BREEZE DEVELOPING...AND HAVE LOW TO
MODERATE CONFIDENCE WITH THE TIMING OF THE WIND SHIFT.
CONVECTION NOT EXPECTED AT THE TERMINALS...HOWEVER...CONVECTION IS
POSSIBLE LATE THIS AFTERNOON INTO THE EARLY EVENING JUST SOUTH OF
THE AREA. DO NOT EXPECT CONVECTION TO DEVELOP THIS FAR NORTH.
TONIGHT...WINDS BECOME LIGHT AND VARIABLE MOST TERMINALS...REMAINING
WESTERLY AT THE NYC METRO TERMINALS. SEA BREEZES LIKELY AGAIN
SUNDAY LATE MORNING INTO THE AFTERNOON.
AMENDMENTS MAY BE NEEDED TODAY FOR TIMING OF WIND SHIFTS.
OUTLOOK FOR 18Z SUNDAY THROUGH THURSDAY...
.SUNDAY-TUESDAY...GENERALLY VFR. ISOLATED AFTERNOON TSTMS POSSIBLE
SUNDAY AND MONDAY.
.WEDNESDAY AND THURSDAY...VFR. SLIGHT CHANCE OF TSTMS.
&&
.MARINE...
WINDS AND SEAS ARE GENERALLY EXPECTED TO REMAIN BELOW SCA LEVELS
THROUGH SUNDAY...ALTHOUGH SWELL FROM WHAT IS LEFTOVER FROM DEBBY
WILL LIKELY MAINTAIN OCEAN SEAS IN THE 3 TO 4 RANGE. COULD SEE
BRIEF 5 FOOTERS TODAY OVER THE OCEAN ZONES.
NEXT WEEK...WINDS AND SEAS ARE FORECAST TO REMAIN BELOW SMALL CRAFT
ADVISORY LIMITS OF 25 KT AND 5 FT.
&&
.HYDROLOGY...
DRY THIS MORNING. THERE IS A LOW PROBABILITY FOR DOWNPOURS
CAPABLE OF CAUSING MINOR URBAN/POOR DRAINAGE FLOODING LATE TODAY
AND TONIGHT. A FLASH FLOOD THREAT COULD UNFOLD IF AN MCS WORKS
INTO THE REGION...BUT PROBABILITY OF OCCURRENCE AT THIS TIME IS
LOW.
&&
.CLIMATE...
HERE ARE THE RECORD HIGHS AND FORECAST TEMPS FOR SATURDAY JUNE 30:
..LOCATION........FORECAST HIGH.......RECORD HIGH.......YEAR....
CENTRAL PARK NY.........93.................99...........1964....
LAGUARDIA NY............95.................97...........1964....
KENNEDY NY..............94.................99...........1964....
NEWARK NJ...............99.................99...........1964....
ISLIP NY................92.................89...........2001....
BRIDGEPORT CT...........92.................94...........1959....
HERE ARE THE RECORD HIGHS AND FORECAST TEMPS FOR SUNDAY JULY 1:
..LOCATION........FORECAST HIGH.......RECORD HIGH.......YEAR....
CENTRAL PARK NY.........94................100...........1901....
LAGUARDIA NY............96.................97...........1964....
KENNEDY NY..............93................102...........1963....
NEWARK NJ...............96................100...........1963....
ISLIP NY................91.................87...........2001....
BRIDGEPORT CT...........90.................95...........1963....
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR NYZ072>075-176-
178.
HEAT ADVISORY FROM NOON TO 7 PM EDT SUNDAY FOR NYZ072>075-176-
178.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...PW
NEAR TERM...PW
SHORT TERM...PW
LONG TERM...PW
AVIATION...MET
MARINE...BC
HYDROLOGY...PW
CLIMATE...
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
524 PM CDT SAT JUN 30 2012
.DISCUSSION...
404 PM CDT
SEVERAL CONCERNS/CHALLENGES CONTINUE THIS FORECAST
PERIOD...DEALING WITH SHOWER/THUNDERSTORM TRENDS AS WELL AS
TEMPS/HEAT INDEX VALUES FOR THE NEXT SEVERAL DAYS.
IN THE NEAR TERM...PRECIP TRENDS ARE THE MAIN CONCERN WITH STILL
AN OUTSIDE POSSIBILITY FOR AN ISOLATED SEVERE THREAT LATE THIS
AFTERNOON AND EARLY EVENING. ALTHOUGH WITH TIME...IT IS APPEARING
AS IF THIS POSSIBILITY IS DIMINISHING. LATEST RADAR IMAGERY IS
SHOWING AN AREA OF SHOWERS AND THUNDERSTORMS THAT CONTINUE TO HUG
THE VERY SOUTHERN PORTION OF THE CWA MAINLY FROM THE SOUTHERN
PORTIONS OF LIVINGSTON...FORD...AND IROQUOIS COUNTIES IN ILLINOIS
EAST TO BENTON COUNTY IN INDIANA. THESE THUNDERSTORMS CONTINUE TO
DEVELOP IN AND AROUND THE STATIONARY BOUNDARY WHICH REMAINS DRAPED
SOUTHEAST IOWA EAST TO CENTRAL ILLINOIS. AS A MID LEVEL WAVE/SPEED
MAX NOTED ON SATELLITE IMAGERY HAS CONTINUED SOUTHEAST INTO THE
AREA THIS AFTERNOON...THERE HAS BEEN SOME BRIEF ENHANCEMENT TO
THUNDERSTORMS BUT WITH THE MORE AGGRESSIVE THUNDERSTORMS STAYING
JUST SOUTH OF THE CWA MORE TOWARDS THIS BOUNDARY AND NEAR AN AXIS
OF BETTER INSTABILITY AND LESS CIN. AS ANOTHER MID LEVEL FEATURE
DROPS SOUTH ACROSS WISCONSIN AS WELL AS FURTHER PRECIP DEVELOPMENT
THIS AFTERNOON...DONT SEE ANY REASON AS TO WHY THIS BOUNDARY WILL
LIFT ANY FURTHER NORTH THIS AFTERNOON AND EARLY EVENING. SO AS
SYNOPTIC LIFT STILL HAS THE POSSIBILITY TO ENHANCE THUNDERSTORM
DEVELOPMENT IN THIS AREA LATE THIS AFTERNOON...IT WOULD APPEAR AS
THE BETTER DEVELOPMENT AND BETTER CHANCES FOR ANY SEVERE WEATHER
WOULD BE JUST SOUTH OF THE CWA. ANOTHER AREA WHICH CONTINUES TO BE
MONITORED IS ACROSS FAR NORTHEAST ILLINOIS NEAR THE LAKE BREEZE.
LATEST RUC ANALYSIS INDICATING THAT ANY CIN HAS ERODED WITH WEAK
TO MODERATE INSTABILITY CURRENTLY RESIDING ACROSS NORTHEAST
ILLINOIS...AS WELL AS WEAK SURFACE CONVERGENCE NOTED. WITH THIS
WEAK FEATURE DROPPING SOUTHEAST OUT OF SOUTH CENTRAL
WISCONSIN...THERE IS STILL AN OUTSIDE POSSIBILITY FOR AN ISOLATED
THUNDERSTORM OR SHOWER TO DEVELOP DESPITE GUIDANCE NOT REALLY
INDICATING THIS POSSIBILITY. OVERALL CONCERNS CONTINUE TO BE NOT
THE GREATEST...BUT DEFINITELY SOMETHING THAT WILL CONTINUE TO BE
MONITORED.
AFTER SOME SLIGHT CHANCE TO CHANCE POPS FOR AREAS MAINLY SOUTH OF
INTERSTATE 80 EARLY THIS EVENING...CONCERNS THEN SHIFT TOWARDS
LATE TONIGHT INTO EARLY SUNDAY MORNING AS CURRENT SETUP IS
INDICATING THAT THUNDERSTORMS WILL BE POSSIBLE ONCE AGAIN. CURRENT
WAVE MOVING THROUGH NEBRASKA WILL WORK ITS WAY EAST TONIGHT INTO
EARLY SUNDAY MORNING WITH LLJ INCREASING ONCE AGAIN
TONIGHT...HELPING TO FEED DEVELOPMENT ACROSS THE CENTRAL PLAINS.
INSTABILITY AND MOISTURE WILL CLEARLY BE MORE THAN SUFFICIENT SUCH
THAT IF ANYTHING DEVELOPS UPSTREAM...IT WILL RIDE ALONG THIS
MOISTURE/INSTABILITY AXIS TOWARDS THE SOUTHERN PORTIONS OF THE
CWA. BOTH THE NAM AND ECMWF ARE INDICATING THIS POSSIBLE
SOLUTION...AND CANNOT DISAGREE WITH THIS GUIDANCE AT THIS TIME.
THE ONLY REAL CONCERN OR UNKNOWNS WILL BE PLACEMENT OF THE
STATIONARY BOUNDARY...WHICH WILL PLAY A FACTOR IN OVERALL
INSTABILITY AND MOISTURE. NONETHELESS...IT WOULD APPEAR AS IF THE
SOUTHERN PORTIONS OF THE CWA SOUTH OF INTERSTATE 80 WILL HAVE
ANOTHER CHANCE AT THUNDERSTORMS MORE TOWARDS EARLY SUNDAY MORNING
WITH THE POSSIBILITY OF LARGE HAIL AND HIGH WINDS ONCE AGAIN. ONCE
THIS PUSHES THROUGH BY MID MORNING...SHOULD SEE SOME CLEARING
OCCUR BY MID DAY SUNDAY. AS WE CONTINUE TO REMAIN IN NORTHWEST
FLOW...SEVERAL WAVES OF ENERGY WILL CONTINUE TO SLIDE SOUTHEAST
THROUGH THE CWA. THIS WILL PLAY A FACTOR WITH DEVELOPMENT ONCE
AGAIN SUNDAY AFTERNOON...WITH BOUNDARY PLACEMENT ONCE AGAIN AN
ISSUE. MODELS DO DEVELOP CONVECTION ONCE AGAIN SUNDAY AFTERNOON
AND ONCE AGREE WITH THIS SCENARIO...BUT WITH THE QUESTION OF WHERE
THE BEST DEVELOPMENT WILL OCCUR. AS THIS COMPLEX MOVES THROUGH
LATE TONIGHT INTO EARLY SUNDAY MORNING...IT WILL MORE THAN LIKELY
PUSH THIS BOUNDARY FURTHER SOUTH. THOUGH MODELS ARE SHOWING THIS
BOUNDARY TRYING TO REBOUND NORTH AGAIN AS LOW/MID LEVEL FLOW BACKS
MORE SOUTHWEST...THE EXTENT OF THIS NORTHWARD PROGRESSION IS STILL
IN QUESTION. IF THIS BOUNDARY COULD LIFT FURTHER NORTH AND SETUP
THROUGH THE CENTER OF THE CWA...THAN THUNDERSTORM DEVELOPMENT WILL
BE POSSIBLE FOR A GOOD PORTION OF THE CWA. IF THE BOUNDARY HANGS
FURTHER SOUTH...THAN WE CAN EXPECT THUNDERSTORMS FURTHER SOUTH. IN
EITHER SCENARIO...THUNDERSTORMS WILL BE POSSIBLE WITH HIGH WINDS
AND LARGE HAIL POSSIBLE ONCE AGAIN FOR A GOOD PORTION OF THE CWA.
HEAT WILL CONTINUE TO BE AN ISSUE OVER THE NEXT SEVERAL DAYS. HAD
CONTEMPLATED AN EXCESSIVE HEAT WARNING FOR OUR FAR SOUTHERN
PORTION OF THE CWA DUE TO THE EXTENDED NATURE OF HIGH HEAT INDEX
VALUES WITH THIS FORECAST PACKAGE...BUT DECIDED NOT TO ISSUE ANY
HEADLINES AT THIS TIME. FORECASTED TEMP AND DEWPOINTS FOR TODAY
ACROSS THE SOUTH NEVER REALLY MATERIALIZED WITH HEAT INDICES
STAYING AROUND 90. WITH QUESTIONS CONCERNING PRECIP AND CLOUD
COVER ON SUNDAY...HAVE HEAT INDICES ONCE AGAIN STAYING BELOW
CRITERIA FOR EITHER ADVISORY OR WARNING. AN EXTENDED PERIOD OF
HIGH HEAT DOES APPEAR AS IF IT IS SETTING UP WITH MODERATE TO HIGH
HUMIDITY SETTING UP ACROSS THE CWA THIS UPCOMING WEEK...WITH HIGH
HEAT INDEX VALUES POSSIBLE FOR MOST OF THIS WEEK.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* LAKE BREEZE BOUNDARY TRYING TO APPROACH ORD...REMAINING EAST OF
MDW.
* SLIGHT CHANCE FOR SHRA/TSRA TO POP UP ALONG LAKE BREEZE JUST
EAST OF TERMINALS NEXT FEW HOURS.
* CHANCES FOR TSRA SUNDAY.
MDB
//DISCUSSION...UPDATED 22Z...
LAKE BREEZE BOUNDARY IS HAVING A HARD TIME PUSHING INLAND TOWARDS
ORD AND REMAINS ANCHORED TO THE SHORELINE EAST OF MDW. HAVE SLOWED
THE ARRIVAL TIME AT ORD AND IT STILL MAY NOT MAKE IT AT ALL.
SHOULD IT MAKE IT TO THE FIELD IT MAY NOT MOVE BEYOND IT AND MAY
START TO RETREAT TO THE EAST AS WINDS JUST OFF THE SURFACE START
TO INCREASE MODESTLY. SATELLITE SHOWS SOME CU DEVELOPING NEAR THE
LAKE BREEZE BOUNDARY AND WITH THE UNSTABLE AIR IN PLACE CANNOT
COMPLETELY RULE OUT AND ISOLATED SHRA/TSRA BUT THE CHANCE IS VERY
LOW.
MDB
FROM 18Z...
A SURFACE BOUNDARY IS JUST TO THE SOUTHWEST OF THE TERMINALS. ONE
AREA OF TSRA HAS BEEN MOVING EASTWARD ALONG THE BOUNDARY THIS
MORNING. ADDITIONAL TSRA MAY DEVELOP NEAR THE BOUNADRY THIS
AFTERNOON OR EVENING AS A MID LEVEL DISTURBANCE MOVES ACROSS THE
AREA. THESE TSRA SHOULD REMAIN TO THE SOUTH AND SOUTHWEST OF ALL THE
TERMINALS.
A LAKE BREEZE IS EXPECTED TO DEVELOP AND PUSH AROSS THE NORTHEAST
ILLINOIS AND NORTHWEST INDIANA TERMINALS MID TO LATE AFTERNOON.
WITH VERY WARM AND UNSTABLE AIR IN PLACE...THE LAKE BREEZE MAY
SERVE AS A FOCUS POINT FOR SHRA/TSRA TO DEVELOP LATE THIS
AFTERNOON INTO THE EVENING HOURS.
AREAS THAT GET PRECIPITATION THIS AFTERNOON AND EVENING HAVE THE
POTENTIAL TO DEVELOP FOG SUNDAY MORNING. FOR NOW THE CHANCES FOR
FOG ARE LOW AND SO HAVE NOT CARRIED IN THE TAF...BUT WILL NEED TO
BE MONITORED.
PAW
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* MEDIUM CONFIDENCE IN LAKE BREEZE REACHING ORD...LOW CONFIDENCE
IN TIMING.
* HIGH CONFIDENCE THAT CHANCE FOR SHRA/TSRA DEVELOPMENT ALONG LAKE
BREEZE IS LOW.
* MEDIUM CONFIDENCE IN SHRA/TSRA OCCURRING AT SOME POINT SUNDAY.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
* SUNDAY NIGHT...VFR.
* MONDAY...VFR. SLIGHT CHANCE OF TSRA.
* TUESDAY THROUGH FRIDAY...VFR.
&&
.MARINE...
153 PM CDT
A WEAK PRESSURE GRADIENT WILL PERSIST THROUGH THE WEEKEND INTO MUCH
OF NEXT WEEK. ONLY A MODEST PRESSURE GRADIENT WILL DEVELOP LATE
MONDAY THROUGH EARLY WEDNESDAY ALLOWING SOUTHWEST BREEZE OF 10 TO
15 KT TO DEVELOP. WINDS WILL DIMINISH AGAIN WEDNESDAY AND THURSDAY
AS HIGH PRESSURE BUILDS ACROSS THE REGION. DURING THESE PERIODS OF
LIGHT WINDS...EXPECT LAKE BREEZE PROCESSES TO DOMINATE THE WIND
FIELDS CAUSING ONSHORE FLOW DURING THE AFTERNOON AND EVENING
HOURS. BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
406 PM CDT SAT JUN 30 2012
.DISCUSSION...
404 PM CDT
SEVERAL CONCERNS/CHALLENGES CONTINUE THIS FORECAST
PERIOD...DEALING WITH SHOWER/THUNDERSTORM TRENDS AS WELL AS
TEMPS/HEAT INDEX VALUES FOR THE NEXT SEVERAL DAYS.
IN THE NEAR TERM...PRECIP TRENDS ARE THE MAIN CONCERN WITH STILL
AN OUTSIDE POSSIBILITY FOR AN ISOLATED SEVERE THREAT LATE THIS
AFTERNOON AND EARLY EVENING. ALTHOUGH WITH TIME...IT IS APPEARING
AS IF THIS POSSIBILITY IS DIMINISHING. LATEST RADAR IMAGERY IS
SHOWING AN AREA OF SHOWERS AND THUNDERSTORMS THAT CONTINUE TO HUG
THE VERY SOUTHERN PORTION OF THE CWA MAINLY FROM THE SOUTHERN
PORTIONS OF LIVINGSTON...FORD...AND IROQUOIS COUNTIES IN ILLINOIS
EAST TO BENTON COUNTY IN INDIANA. THESE THUNDERSTORMS CONTINUE TO
DEVELOP IN AND AROUND THE STATIONARY BOUNDARY WHICH REMAINS DRAPED
SOUTHEAST IOWA EAST TO CENTRAL ILLINOIS. AS A MID LEVEL WAVE/SPEED
MAX NOTED ON SATELLITE IMAGERY HAS CONTINUED SOUTHEAST INTO THE
AREA THIS AFTERNOON...THERE HAS BEEN SOME BRIEF ENHANCEMENT TO
THUNDERSTORMS BUT WITH THE MORE AGGRESSIVE THUNDERSTORMS STAYING
JUST SOUTH OF THE CWA MORE TOWARDS THIS BOUNDARY AND NEAR AN AXIS
OF BETTER INSTABILITY AND LESS CIN. AS ANOTHER MID LEVEL FEATURE
DROPS SOUTH ACROSS WISCONSIN AS WELL AS FURTHER PRECIP DEVELOPMENT
THIS AFTERNOON...DONT SEE ANY REASON AS TO WHY THIS BOUNDARY WILL
LIFT ANY FURTHER NORTH THIS AFTERNOON AND EARLY EVENING. SO AS
SYNOPTIC LIFT STILL HAS THE POSSIBILITY TO ENHANCE THUNDERSTORM
DEVELOPMENT IN THIS AREA LATE THIS AFTERNOON...IT WOULD APPEAR AS
THE BETTER DEVELOPMENT AND BETTER CHANCES FOR ANY SEVERE WEATHER
WOULD BE JUST SOUTH OF THE CWA. ANOTHER AREA WHICH CONTINUES TO BE
MONITORED IS ACROSS FAR NORTHEAST ILLINOIS NEAR THE LAKE BREEZE.
LATEST RUC ANALYSIS INDICATING THAT ANY CIN HAS ERODED WITH WEAK
TO MODERATE INSTABILITY CURRENTLY RESIDING ACROSS NORTHEAST
ILLINOIS...AS WELL AS WEAK SURFACE CONVERGENCE NOTED. WITH THIS
WEAK FEATURE DROPPING SOUTHEAST OUT OF SOUTH CENTRAL
WISCONSIN...THERE IS STILL AN OUTSIDE POSSIBILITY FOR AN ISOLATED
THUNDERSTORM OR SHOWER TO DEVELOP DESPITE GUIDANCE NOT REALLY
INDICATING THIS POSSIBILITY. OVERALL CONCERNS CONTINUE TO BE NOT
THE GREATEST...BUT DEFINITELY SOMETHING THAT WILL CONTINUE TO BE
MONITORED.
AFTER SOME SLIGHT CHANCE TO CHANCE POPS FOR AREAS MAINLY SOUTH OF
INTERSTATE 80 EARLY THIS EVENING...CONCERNS THEN SHIFT TOWARDS
LATE TONIGHT INTO EARLY SUNDAY MORNING AS CURRENT SETUP IS
INDICATING THAT THUNDERSTORMS WILL BE POSSIBLE ONCE AGAIN. CURRENT
WAVE MOVING THROUGH NEBRASKA WILL WORK ITS WAY EAST TONIGHT INTO
EARLY SUNDAY MORNING WITH LLJ INCREASING ONCE AGAIN
TONIGHT...HELPING TO FEED DEVELOPMENT ACROSS THE CENTRAL PLAINS.
INSTABILITY AND MOISTURE WILL CLEARLY BE MORE THAN SUFFICIENT SUCH
THAT IF ANYTHING DEVELOPS UPSTREAM...IT WILL RIDE ALONG THIS
MOISTURE/INSTABILITY AXIS TOWARDS THE SOUTHERN PORTIONS OF THE
CWA. BOTH THE NAM AND ECMWF ARE INDICATING THIS POSSIBLE
SOLUTION...AND CANNOT DISAGREE WITH THIS GUIDANCE AT THIS TIME.
THE ONLY REAL CONCERN OR UNKNOWNS WILL BE PLACEMENT OF THE
STATIONARY BOUNDARY...WHICH WILL PLAY A FACTOR IN OVERALL
INSTABILITY AND MOISTURE. NONETHELESS...IT WOULD APPEAR AS IF THE
SOUTHERN PORTIONS OF THE CWA SOUTH OF INTERSTATE 80 WILL HAVE
ANOTHER CHANCE AT THUNDERSTORMS MORE TOWARDS EARLY SUNDAY MORNING
WITH THE POSSIBILITY OF LARGE HAIL AND HIGH WINDS ONCE AGAIN. ONCE
THIS PUSHES THROUGH BY MID MORNING...SHOULD SEE SOME CLEARING
OCCUR BY MID DAY SUNDAY. AS WE CONTINUE TO REMAIN IN NORTHWEST
FLOW...SEVERAL WAVES OF ENERGY WILL CONTINUE TO SLIDE SOUTHEAST
THROUGH THE CWA. THIS WILL PLAY A FACTOR WITH DEVELOPMENT ONCE
AGAIN SUNDAY AFTERNOON...WITH BOUNDARY PLACEMENT ONCE AGAIN AN
ISSUE. MODELS DO DEVELOP CONVECTION ONCE AGAIN SUNDAY AFTERNOON
AND ONCE AGREE WITH THIS SCENARIO...BUT WITH THE QUESTION OF WHERE
THE BEST DEVELOPMENT WILL OCCUR. AS THIS COMPLEX MOVES THROUGH
LATE TONIGHT INTO EARLY SUNDAY MORNING...IT WILL MORE THAN LIKELY
PUSH THIS BOUNDARY FURTHER SOUTH. THOUGH MODELS ARE SHOWING THIS
BOUNDARY TRYING TO REBOUND NORTH AGAIN AS LOW/MID LEVEL FLOW BACKS
MORE SOUTHWEST...THE EXTENT OF THIS NORTHWARD PROGRESSION IS STILL
IN QUESTION. IF THIS BOUNDARY COULD LIFT FURTHER NORTH AND SETUP
THROUGH THE CENTER OF THE CWA...THAN THUNDERSTORM DEVELOPMENT WILL
BE POSSIBLE FOR A GOOD PORTION OF THE CWA. IF THE BOUNDARY HANGS
FURTHER SOUTH...THAN WE CAN EXPECT THUNDERSTORMS FURTHER SOUTH. IN
EITHER SCENARIO...THUNDERSTORMS WILL BE POSSIBLE WITH HIGH WINDS
AND LARGE HAIL POSSIBLE ONCE AGAIN FOR A GOOD PORTION OF THE CWA.
HEAT WILL CONTINUE TO BE AN ISSUE OVER THE NEXT SEVERAL DAYS. HAD
CONTEMPLATED AN EXCESSIVE HEAT WARNING FOR OUR FAR SOUTHERN
PORTION OF THE CWA DUE TO THE EXTENDED NATURE OF HIGH HEAT INDEX
VALUES WITH THIS FORECAST PACKAGE...BUT DECIDED NOT TO ISSUE ANY
HEADLINES AT THIS TIME. FORECASTED TEMP AND DEWPOINTS FOR TODAY
ACROSS THE SOUTH NEVER REALLY MATERIALIZED WITH HEAT INDICES
STAYING AROUND 90. WITH QUESTIONS CONCERNING PRECIP AND CLOUD
COVER ON SUNDAY...HAVE HEAT INDICES ONCE AGAIN STAYING BELOW
CRITERIA FOR EITHER ADVISORY OR WARNING. AN EXTENDED PERIOD OF
HIGH HEAT DOES APPEAR AS IF IT IS SETTING UP WITH MODERATE TO HIGH
HUMIDITY SETTING UP ACROSS THE CWA THIS UPCOMING WEEK...WITH HIGH
HEAT INDEX VALUES POSSIBLE FOR MOST OF THIS WEEK.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* LAKE BREEZE MOVING THROUGH LATE AFTERNOON AND TURNING THE WINDS
TO THE NORTHEAST.
* LOW CHANCE FOR TSRA WITH THE LAKE BREEZE LATE THIS AFTERNOON
INTO THE EVENING.
PAW
//DISCUSSION...UPDATED 18Z...
A SURFACE BOUNDARY IS JUST TO THE SOUTHWEST OF THE TERMINALS. ONE
AREA OF TSRA HAS BEEN MOVING EASTWARD ALONG THE BOUNDARY THIS
MORNING. ADDITIONAL TSRA MAY DEVELOP NEAR THE BOUNADRY THIS
AFTERNOON OR EVENING AS A MID LEVEL DISTURBANCE MOVES ACROSS THE
AREA. THESE TSRA SHOULD REMAIN TO THE SOUTH AND SOUTHWEST OF ALL THE
TERMINALS.
A LAKE BREEZE IS EXPECTED TO DEVELOP AND PUSH AROSS THE NORTHEAST
ILLINOIS AND NORTHWEST INDIANA TERMINALS MID TO LATE AFTERNOON.
WITH VERY WARM AND UNSTABLE AIR IN PLACE...THE LAKE BREEZE MAY
SERVE AS A FOCUS POINT FOR SHRA/TSRA TO DEVELOP LATE THIS
AFTERNOON INTO THE EVENING HOURS.
AREAS THAT GET PRECIPITATION THIS AFTERNOON AND EVENING HAVE THE
POTENTIAL TO DEVELOP FOG SUNDAY MORNING. FOR NOW THE CHANCES FOR
FOG ARE LOW AND SO HAVE NOT CARRIED IN THE TAF...BUT WILL NEED TO
BE MONITORED.
PAW
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM CONFIDENCE IN LAKE BREEZE TIMING.
* LOW CONFIDENCE IN TSRA ASSOCIATED WITH THE LAKE BREEZE.
PAW
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
* SUNDAY NIGHT...VFR.
* MONDAY...VFR. SLIGHT CHANCE OF TSRA.
* TUESDAY THROUGH FRIDAY...VFR.
&&
.MARINE...
153 PM CDT
A WEAK PRESSURE GRADIENT WILL PERSIST THROUGH THE WEEKEND INTO MUCH
OF NEXT WEEK. ONLY A MODEST PRESSURE GRADIENT WILL DEVELOP LATE
MONDAY THROUGH EARLY WEDNESDAY ALLOWING SOUTHWEST BREEZE OF 10 TO
15 KT TO DEVELOP. WINDS WILL DIMINISH AGAIN WEDNESDAY AND THURSDAY
AS HIGH PRESSURE BUILDS ACROSS THE REGION. DURING THESE PERIODS OF
LIGHT WINDS...EXPECT LAKE BREEZE PROCESSES TO DOMINATE THE WIND
FIELDS CAUSING ONSHORE FLOW DURING THE AFTERNOON AND EVENING
HOURS. BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1238 PM CDT SAT JUN 30 2012
.DISCUSSION...
ISSUED 1008 AM CDT SAT JUN 30 2012
ISSUED A QUICK ZONE UPDATE THIS MORNING TO EXTEND LOW CHANCE POPS
FURTHER SOUTH. OUTFLOW BOUNDARY FROM OVERNIGHT CONVECTION ACROSS
NORTHERN ILLINOIS HAS SETTLED INTO THE KILX CWA...WITH 15Z
SATELLITE/RADAR DATA SHOWING ITS CURRENT LOCATION FROM JUST NORTH
OF PARIS TO NEAR TAYLORVILLE. A FEW SHOWERS ARE BEGINNING TO
DEVELOP ALONG THE BOUNDARY...SO FELT POPS WERE WARRANTED TO NEAR
THE I-70 CORRIDOR. FURTHER SOUTH...WILL MAINTAIN A HOT/DRY
FORECAST FOR THE SOUTHEAST CWA. BEST RAIN CHANCES TODAY WILL ONCE
AGAIN BE CONFINED TO LOCATIONS ALONG/NORTH OF I-74...IN CLOSER
PROXIMITY TO STATIONARY FRONTAL BOUNDARY. HRRR MODEL GENERALLY
SHOWS CURRENT CLUSTER OF SHOWERS/STORMS N/NW OF THE PEORIA AREA
TRACKING E/SE INTO INDIANA BY THIS AFTERNOON. WILL CARRY 40 POPS
ACROSS THE N/NE CWA FROM PEORIA TO CHAMPAIGN-URBANA ACCORDINGLY.
HIGH TEMPS STILL LOOK TO BE ON TARGET...WITH READINGS IN THE LOWER
90S FAR NORTH...TO OVER 105 DEGREES SOUTH OF I-70.
&&
.AVIATION...
ISSUED 1238 PM CDT SAT JUN 30 2012
SCATTERED CONVECTION WILL CONTINUE TO DEVELOP AND TRACK E/SE ALONG
A STATIONARY FRONTAL BOUNDARY THIS AFTERNOON INTO THE EARLY
EVENING. 16Z RAPID REFRESH MODEL SEEMS TO HAVE THE BEST HANDLE ON
THE CURRENT SITUATION...SO WILL TREND TOWARD ITS SOLUTION FOR THE
SHORT-TERM FORECAST. STORMS ALONG THE I-74 CORRIDOR BETWEEN KGBG
AND KPIA WILL SHIFT E/SE AS THE DAY PROGRESSES...EVENTUALLY
PUSHING INTO INDIANA BY EARLY EVENING. BASED ON LATEST RADAR
IMAGERY...HAVE INCLUDED TEMPO THUNDER AT KPIA BETWEEN 18Z AND 20Z.
FURTHER EAST...WILL ONLY MENTION VCTS AT KBMI AND KCMI UNTIL
CONVECTIVE TRENDS BECOME BETTER ESTABLISHED. AS WEAK UPPER-LEVEL
WAVE TRACKS FURTHER EAST...WILL END THUNDER CHANCES FROM WEST TO
EAST BETWEEN 01Z AND 03Z. FURTHER SOUTH...WILL CONTINUE TO
MAINTAIN DRY CONDITIONS THROUGH THE ENTIRE 18Z TAF PERIOD AT BOTH
KSPI AND KDEC.
BARNES
&&
.PREV DISCUSSION...
ISSUED 305 AM CDT SAT JUN 30 2012
THUNDERSTORM ACTIVITY HAS BEEN PRESENT ACROSS THE NORTHERN CWA
THE LAST FEW HOURS...WITH SOME DEVELOPMENT ALSO OCCURRING NEAR
CHAMPAIGN AND DANVILLE AROUND 130 AM ON ONE OF THE OUTFLOWS FROM
EARLIER CONVECTION. THE SOUTHERNMOST OUTFLOW WAS GENERALLY JUST
NORTH OF A PARIS TO SHELBYVILLE LINE...WITH WINDS BEHIND IT
SHIFTING TO THE NORTHEAST. SOME INTERESTING TEMPERATURE ANTICS
AHEAD OF THIS BOUNDARY...WITH FLORA AND OLNEY BOTH SEEING TEMPS
JUMP 5-7 DEGREES BETWEEN 1 AND 2 AM...AND EFFINGHAM GOING UP 5
DEGREES SHORTLY AFTER MIDNIGHT.
SHORT TERM...TODAY THROUGH MONDAY...
MAIN CONCERN DURING THIS PERIOD WILL BE WITH CONVECTIVE CHANCES
AND TEMPERATURES...AS THE FORMER WILL DIRECTLY IMPACT THE LATTER.
SHORTWAVE CURRENTLY EXTENDING FROM THE WESTERN GREAT LAKES INTO
IOWA WILL SWING THROUGH THE REGION TODAY. SURFACE BOUNDARY/FRONT
IS PROGGED BY THE MODELS TO SLIP SOUTHWARD INTO THE CWA THIS
EVENING. EXTENT OF CONVECTIVE REDEVELOPMENT WILL HINGE ON HOW FAST
THE CURRENT STORMS DIMINISH...ALLOWING THE ATMOSPHERE TO RECHARGE.
WILL SEE DEW POINTS POOLING JUST SOUTH OF THE BOUNDARY...SO CAPES
ACROSS THE NORTHERN CWA WILL LIKELY EXCEED 3000 J/KG BY MID-
AFTERNOON. WILL KEEP MOST OF THE RAIN CHANCES NORTH OF A
BEARDSTOWN TO DANVILLE LINE TODAY...WITH SOME SLIGHT CHANCES ALONG
THE I-72 CORRIDOR.
EVENING MODELS SHOWING A SERIES OF MCS POTENTIAL TONIGHT AND
SUNDAY...WITH THE NORTH HALF OF THE CWA THE PRIMARY RECIPIENTS.
TIMING TONIGHT IS NOT AS CONSISTENT AMONG THE MODELS...SO WILL
NOT TRY TO BREAK IT DOWN WITH EVENING VS OVERNIGHT WORDING. SUNDAY
AFTERNOON IS IN BETTER AGREEMENT AS CAPES AGAIN REACH 3000-4000
J/KG BY MID-AFTERNOON. SPC CONVECTIVE OUTLOOKS FOR TODAY AND
SUNDAY BOTH HAVE SLIGHT RISKS FOR THE NORTHERN HALF OF THE CWA. BY
MONDAY... UPPER RIDGING ACROSS THE PLAINS WILL BE BUILDING TOWARD
THE MISSISSIPPI VALLEY...SHUNTING THE MCS ACTIVITY MORE TO OUR
EAST.
TEMPERATURE-WISE...THINK THE VARIOUS BOUNDARIES AND CLOUDS WILL
KEEP THE NORTHERN CWA SLIGHTLY COOLER THE NEXT FEW DAYS...WITH
MID 90S FOR HIGHS...AS OPPOSED TO THE 100+ ACROSS THE CENTRAL AND
SOUTH. AS A RESULT...WILL DOWNGRADE THE EXCESSIVE HEAT WARNING
NORTH OF A GALESBURG TO BLOOMINGTON LINE...REPLACING IT WITH A
HEAT ADVISORY. WILL KEEP THE WARNING GOING FURTHER SOUTH. HAVE
GONE WITH TEMPS 105 OR HIGHER ACROSS THE SOUTHEAST TODAY...WHERE
MORE MIXING WILL TAKE PLACE...AND 100-105 FOR SUNDAY AND MONDAY.
THE HEAT HEADLINES MAY NEED TO BE EXTENDED IN TIME...BUT QUESTIONS
REGARDING THE OUTFLOWS AND CONVECTION PRECLUDE THIS AT THE MOMENT.
LONG TERM...TUESDAY THROUGH FRIDAY...
UPPER RIDGE CONTINUES TO DOMINATE THE EASTERN HALF OF THE
NATION. 850 MB TEMPERATURES REMAIN IN THE 23-24C RANGE OVER OUR
AREA...WITH MID TO UPPER 90S FOR HIGHS. WILL KEEP DRY WEATHER
THROUGH THE PERIOD.
GEELHART
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
EXCESSIVE HEAT WARNING UNTIL 7 PM CDT SUNDAY FOR ILZ036-040>057-
061>063-066>068-071>073.
HEAT ADVISORY UNTIL 7 PM CDT SUNDAY FOR ILZ027>031-037-038.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
421 PM EDT SAT JUN 30 2012
.SHORT TERM...
TONIGHT THROUGH SATURDAY NIGHT. MESOVORT INDUCED INITIATION OF
DEEP MOIST DEEP CONVECTION PAST HOUR INVOF KRZL SLOW TO
STRENGTHEN SO FAR. COMBO OF LESSER DOWNSTREAM AVBL ENERGY/MLCAPE
DUE TO DOWNSHEARED CI SHIELDING AND RELATIVELY MUNDANE SFC-7H
WIND PROFILE...WITH MORE VIGOROUS MIDLVL FLOW OUTPACING
CONVECTION/SHUNTED FURTHER DOWNSTREAM WITH TIME AFFORDING A BIT
WEAKER THAN ANTICIPATED DEEP LAYER SHEAR. HAVE RELEGATED SCT/SVR
POTNL TO FAR SRN/SERN CWA AS SOME POCKETS OF GRTR HEATING/LWR 90S
WITH UPR 60S DPS OBSERVED PER MESONET. CONVECTION TIMED TO END
ACRS SERN AROUND 00 UTC AND ALSO BEGIN NEAR/WITH SUNSET.
THEREAFTER...ONLY LOW CHCS LATE TONIGHT FOR MCS ENTERING SWRN HALF
CWA. APPEARS CWA WELL REMOVED FM BIFURCATED LLJ WITH VEERED NERN
BRANCH OF PLAINS 925-8H JETLET LACKING ROBUST CHARACTER...AND
STRONGER/VEERED NWRN BRANCH TO LKLY FOCUS REGENERATIVE CONVECTION
ACRS HIGH PLAINS INTO SRN MN/IA. IF THIS PANS OUT...LACK OF STRONG
TURNOVER SHOULD ALLOW MORE OPTIMAL DESTABILIZATION THROUGH SUNDAY.
HAVE HIGHLIGHTED AFTN HOURS AGAIN WITH HIEST POPS FOR CONDL
CONVECTIVE CHCS. LOW SPECIFICITY WRT CONVECTIVE DETAILS...AS
TURBIDITY OF MESO/STORMSCADLE DETAILS OBFUSCATE ANY ATTEMPT FOR
MORE THAN BROAD BRUSHED CHC/SLGHT CHC. FOCUS OF HIEST POPS ACRS
WRN/SRN PART OF CWA WHERE RICHER LLVL THETA-E RESIDES AND TOKEN
MENTION WRT SVR POTNL IN HWO ATTM.
&&
.LONG TERM... / MONDAY THROUGH SATURDAY /
...HOT AND MAINLY DRY WX EXPECTED...
A FOUR CORNERS/CENTRAL PLAINS UPPER RIDGE WILL BUILD NEWD INTO THE
MIDWEST/GREAT LAKES THIS PERIOD IN RESPONSE TO RENEWED TROUGHING
ALONG THE EAST/WEST COASTS. ON MONDAY AND TUESDAY THE LOCAL AREA
WILL STILL BE IN A SOMEWHAT PRECARIOUS POSITION WRT SHOWER/STORM
CHANCES ON THE NERN FRINGE OF THIS UPPER RIDGE WITHIN NORTHWESTERLY
FLOW ALOFT. THIS WILL PLACE THE INSTABILITY AXIS / LOW LVL THETA-E
RIDGE "IN THE VICINITY" DURING THIS TIME. THIS WEAK DIFFUSE LOW LVL
CONVERGENT BOUNDARY AND EXPECTED DIFFICULT TO TIME LOW AMPLITUDE
SHORTWAVES RIPPLING THROUGH THE FLOW WILL LIKELY COMBINE TO FORCE
ADDITIONAL CONVECTIVE COMPLEXES ACROSS THE UPPER MIDWEST AND GREAT
LAKES THROUGH AT LEAST TUESDAY...LIKELY DEVELOPING ALONG THE NOSE OF
A LLJ IN THE UPPER MIDWEST AND THEN ATTEMPTING TO MAKE A RUN AT THE
GREAT LAKES AND NORTHERN OHIO VALLEY FOLLOWING CLOSE TO THE SHALLOW
QUASI STATIONARY BOUNDARY THAT WILL BE MIXING NEWD DURING THIS TIME.
THERE ARE TOO MANY MESOSCALE UNCERTAINTIES WRT TO MCS
DEVELOPMENT/TRACK/TIMING AND ASSOCIATED COMPOSITE/RESIDUAL OUTFLOWS
THAT MAKE FORECASTING POPS/WX IN THIS TYPE OF PATTERN VERY
DIFFICULT. AS A RESULT DID NOT MAKE ANY SIGNIFICANT CHANGES TO LOW
CHC POPS MONDAY INTO TUESDAY. THIS UNCERTAINTY WITH CONVECTION/CLOUD
DEBRIS/OUTFLOWS ALSO MAKES MONDAY/TUESDAY HIGH TEMPS A CHALLENGE
WITH NO CHANGES MADE. UPPER RIDGE AND ASSOCIATED STRONG SUBSIDENCE
LOOKS TO BUILD IN FOR THE MID TO LATE WEEK PERIOD RESULTING IN
MAINLY DRY WX AND TEMPERATURES WELL ABOVE NORMAL...POSSIBLY
APPROACHING THE UPPER 90S/NEAR 100 FOR SEVERAL DAYS WITH HEAT
RELATED HEADLINES EVENTUALLY POSSIBLE. WILL MENTION HEAT/HUMIDITY
CONCERNS IN THE HWO FOR NOW. A MORE PRONOUNCED SHORTWAVE CRESTING
THE UPPER RIDGE MAY HELP TO SUPPRESS THE RIDGE AND FORCE ANOTHER
FRONTAL BOUNDARY SOUTH INTO THE AREA BY NEXT WEEKEND. THIS COULD
BRING SHOWERS/STORMS AND POSSIBLY SOME RELIEF FROM THE HEAT BY
SOMETIME NEXT WEEKEND OR EARLY THE FOLLOWING WEEK.
&&
.AVIATION...
LATEST HRRR-3KM BEGINNING TO PICK UP ON PONTL CONVECTIVE
INITIATION THIS AFTN ACRS NRN/CNTL IN. DEGREE OF MODERATE
INSTABILITY WITH LATEST RAP AT 21 UTC INCRSG SFC BASED INSTABILITY
TO 3500-4500 J/KG KFWA/KMIE RGN WWD INTO ERN IA. GIVEN LOW POINT
CHCS FOR TSRA AT AIRFIELD HAVE OPTED FOR VCTS/CB MENTION IN
SHORT/2HR WINDOW AT KFWA 22-24 UTC. THEREAFTER...VFR SANS SENSIBLE
WEATHER. POTNL FOR NOCTURNAL/ERLY AM CONVECTIVE COMPLEX INTO NRN
IN REMAINS LOW AND QUITE CONDITIONAL. BETTER CHCS BEGINNING TO
EMERGE FOR ROBUST CONVECTIVE DEVELOPMENT SUN AFTN/EVE...TO BE
ASSESSED IN FURTHER DETAIL WITH LATER TAF ITERATIONS.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...MURPHY
LONG TERM...STEINWEDEL
AVIATION...MURPHY
AREA FORECAST DISCUSSION...UPDATED
NWS NORTHERN INDIANA
150 PM EDT SAT JUN 30 2012
.AVIATION...
LATEST HRRR-3KM BEGINNING TO PICK UP ON PONTL CONVECTIVE INITIATION
THIS AFTN ACRS NRN/CNTL IN. DEGREE OF MODERATE INSTABILITY WITH
LATEST RAP AT 21 UTC INCRSG SFC BASED INSTABILITY TO 3500-4500 J/KG
KFWA/KMIE RGN WWD INTO ERN IA. GIVEN LOW POINT CHCS FOR TSRA AT
AIRFIELD HAVE OPTED FOR VCTS/CB MENTION IN SHORT/2HR WINDOW AT KFWA
22-24 UTC. THEREAFTER...VFR SANS SENSIBLE WEATHER. POTNL FOR
NOCTURNAL/ERLY AM CONVECTIVE COMPLEX INTO NRN IN REMAINS LOW AND
QUITE CONDITIONAL. BETTER CHCS BEGINNING TO EMERGE FOR ROBUST
CONVECTIVE DEVELOPMENT SUN AFTN/EVE...TO BE ASSESSED IN FURTHER
DETAIL WITH LATER TAF ITERATIONS.
&&
.UPDATE...
SIMILAR ANTECEDENT CONDS AS SEEN YDAY...THOUGH INSTABILITY
CERTAINLY MORE SUBDUED. WHILE THE PRIMARY SAHLLOW FNTL BNDRY WELL
SOUTH OF REGN...FM JUST N OF KSTL-KTAZ-NRN INDY METRO AREA-KCMH
ATTM NOTED BY PERTURBED SCCAS/ACCAS ALONG LLVL CONVERGENCE ZONE...
THE RIBBON OF RICHEST THETA-E AIR IN LWST HALF RESIDES NORTH OF
THIS FEATURE. STRONG LATE AM/MIDDAY SFC INSOLATION ACRS NRN
INDIANA WITH 68-70F SFC DPS PROVIDING MLCAPE IN 1500-2500 J/KG
RANGE WITH AN ADDNL 1000-1500 J/KG INCRS ANTICIPATED AROUND PEAK
HEATING SOUTH OF ROUTE 6...PER LATEST MODIFIED RAP/NAM SNDGS W/ LWR
90S/UPR 60S. IN ADDN TO STRONG INSTABILTY...MODERATE DEEP LAYER
SHEAR OF 40-50KTS LIES ACRS CNTL IL/SRN CWA INTO CNTL INDIANA INTO
SRN HALF OF OHIO TO AID UPDRAFT ORGANIZATION. ANTIPATE
RENEWED/INVIGORATED SFC BASED CONVECTION TO INITIATE
UPSTREAM...EITHER ASSOCD W/ MESOVORT NEAR KPTN DROPPING ESE AT 30
KTS OR UPSCALE GROWTH OF SMALL CONVECTIVE CLUSTER IMMEDIATELY
UPSTREAM OF MESOVORT. FAST STEERING FLOW/MID LVL DRY AIR
ENTRAINMENT/ALONG WITH RELATIVELY DRY SUBCLOUD ENVIRON SUGGESTS
ISOLD DAMAGING WINDS/ACCELERATING DOWNDRAFTS AS PRIMARY
RISK...STRONG UPDRAFTS THROUGH HAIL GROWTH REGN FOR
LESSER/SECONDARY THREAT. UPDATE SENT ABOUT HR AGO...WL CONT TO
MONITOR DESTAB TRENDS BEFORE ANY FURTHER CHNGS.
&&
.PREV DISCUSSION... /ISSUED 413 AM EDT SAT JUN 30 2012/
SHORT TERM... /TODAY THROUGH SUNDAY NIGHT/
CONVECTIVELY INDUCED BOUNDARY CURRENTLY LOCATED SOUTH OF THE
FORECAST AREA...KEEPING THE GREATER INSTABILITY AND MSTR TRAPPED
WITH IT. LLJ ACROSS IA INTO ILLINOIS HAS ALLOWED FOR MULTIPLE
CLUSTERS OF STORMS TO FORM AND MOVE INTO PORTIONS OF WESTERN
INDIANA...BEFORE SLOWLY WEAKENING AS THEY ENCOUNTER THE WELL WORKED
OVER AIRMASS STILL IN PLACE FROM YESTERDAYS DERECHO. ADDITIONAL MUCH
NEEDED RAINFALL...ALBEIT IT GENERALLY LIGHT...HAS AFFECTED MUCH OF
THE AREA OVER THE PAST SEVERAL HOURS...BUT SHOULD BEGIN TO SEE A
DOWNWARD TREND IN MOST LOCATIONS. THE EXCEPTION WILL BE IN FAR
SOUTHERN COUNTIES CLOSER TO THE BEST LL MSTR FEED AND INSTABILITY.
EVEN THIS ACTIVITY HAS STRUGGLED WITH DECENT CORES APPEARING NOW AND
THEN BUT UNABLE TO UTILIZE THE HIGHER WIND FIELDS ALOFT WHERE 40 KTS
OF BULK SHEAR WAS IN PLACE. CLUSTER OF THUNDERSTORMS HAS DEVELOPED
OVER THE PAST HOUR ACROSS CENTRAL INDIANA...WITH SOME POTENTIAL TO
MERGE WITH CURRENT ACTIVITY SOUTH OF US 24. GIVEN TRENDS HAVE
DECIDED TO GO WITH PRE 1ST PERIOD OF LIKELY POPS ACROSS MUCH OF
THE AREA TO COVER STRATIFORM DEVELOPMENT AS WELL AS MORE
SUBSTANTIAL CONVECTION TO THE SOUTH.
FEW CHANGES TO THE REMAINDER OF THE FORECAST WITH SIGNALS POINTING
TOWARDS BEST CONVECTIVE POTENTIAL SOUTH OF THE AREA TODAY. CANNOT
RULE OUT ADDITIONAL SUBTLE WAVES MOVING IN THROUGHOUT THE DAY AND
WITH SUNSHINE EXPECTED TO ALLOW SOARING TEMPS BACK INTO THE 90S
AGAIN...INSTABILITY WILL BE IN PLACE TO ALLOW FOR SLGT CHC TO CHC
POPS FOR STORMS WITH BEST FOCUS SOUTH. DEWPTS SHOULD REMAIN LOW
ENOUGH TODAY TO KEEP HEAT INDICES IN CHECK WITH VALUES IN THE MID TO
MAYBE UPPER 90S. WILL CONTINUE WITH HWO MENTION.
SUNDAY INTO SUNDAY NIGHT...PRETTY MUCH SAME STORY WITH BOUNDARY
STILL IN THE AREA. EXACT LOCATION DIFFICULT TO PREDICT GIVEN
CONVECTIVE COMPLEX DEVELOPMENT OVER THE NEXT 24 HOURS LIKELY TO MESS
WITH LOCATION OF EFFECTIVE BOUNDARY. HAVE WENT WITH SLGT CHC IN FAR
S COUNTIES SUNDAY BUT DRY SUNDAY NIGHT WITH LACK OF OVERALL SUPPORT
ATTM. SPC DAY 3 ELUDES TO SOME POTENTIAL SUNDAY NIGHT FOR
CONVECTION...BUT CONFIDENCE LOW AT THIS POINT. HIGHS IN THE 90S AND
LOWS IN THE 60S WILL PREVAIL.
LONG TERM...MONDAY THROUGH FRIDAY
FOR MONDAY/TUESDAY...A SERIES OF PROGRESSIVE SMALL SCALE SHORT WAVES
FROM EASTERN PACIFIC TROUGH WILL CONTINUE TO AFFECT THE AREA WITH
DAMPENED UPPER RIDGING PERSISTING ACROSS CENTRAL CONUS. 850 HPA
RIDGING SHOULD GRADUALLY SINK SOUTHEAST ACROSS GULF COAST STATES ON
MONDAY SETTING UP A SLIGHTLY STRONGER WESTERLY FLOW REGIME FOR THE
SOUTHERN GREAT LAKES THAT SHOULD INDUCE ANOTHER PERIOD OF WEAK LOW
LEVEL THETAE ADVECTION. GIVEN ABOVE FACTORS...AND DISTINCT
POSSIBILITY THAT UPSTREAM PLAINS SMALLER SCALE WAVES MAY BECOME
CONVECTIVELY ENHANCED...DID ADD SLIGHT CHANCE TSRA POPS FOR MONDAY.
POSITIONING OF MEAN UPPER LEVEL RIDGE AND FAVORABLE THICKNESS
ORIENTATION WOULD SUGGEST REGION COULD BE INLINE FOR ADDITIONAL MCS
ACTIVITY MONDAY NIGHT INTO TUESDAY. HOWEVER...AT THIS FORECAST
DISTANCE WILL CONTINUE TO BE CONSERVATIVE WITH POPS DUE TO LOW
CONFIDENCE IN EXACT PLACEMENT OF STRONGER LOW LEVEL MOISTURE
CONVERGENCE/AND TRACK OF ANY CONVECTIVELY INDUCED VORTS. MEDIUM
RANGE MODELS STILL IN FAIRLY GOOD AGREEMENT OF RISING MID LEVEL
HEIGHTS BY THU/FRI KEEPING PRECIP POTENTIAL NORTH AND EAST OF THE
AREA. DID TWEAK CR ALLBLEND TEMPS/POPS MORE TOWARD THE PREVIOUS
FORECAST WHICH FALL MORE INLINE WITH WARMER ECMWF MOS THAT STILL
APPEARS TO HAVE A BETTER HANDLE ON WARMER IDEA WITH LOWER TO MID 90S
FOR THU/FRI. GFS/MEX GUIDANCE DOES APPEAR TO BECOMING AROUND TO THIS
WARMER IDEA HOWEVER. GIVEN EARLY TO MID WEEK SUSCEPTIBILITY TO
PERIODIC CONVECTIVE POTENTIAL...HIGHS DURING THIS PERIOD OF SOMEWHAT
LOWER CONFIDENCE DUE TO POTENTIAL INFLUENCES FROM
CLOUDS/PRECIP/CONVECTIVE OUTFLOWS BUT WILL CONTINUE TO HEDGE TOWARD
GENERALLY LOWER 90S THROUGH THIS PERIOD.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...FISHER
LONG TERM...MARSILI
AVIATION...MURPHY
UPDATE...MURPHY
AREA FORECAST DISCUSSION
NWS GAYLORD MI
701 PM EDT SAT JUN 30 2012
.SYNOPSIS...
ISSUED AT 259 PM EDT SAT JUN 30 2012
THE GREAT LAKES WILL BE BETWEEN SYSTEMS INTO THE MIDDLE OF THE
UPCOMING WORK WEEK...AS A WEAK STORM SYSTEM SLOWLY LIFTS INTO
QUEBEC...WHILE WEAK HIGH PRESSURE BUILDS OVER THE STATE. THIS
PATTERN WILL GENERATE SEASONAL SUMMER TIME WEATHER...ACROSS NORTHERN
MICHIGAN THROUGH THE FOURTH OF JULY HOLIDAY. THERE IS A SMALL CHANCE
OF SHOWERS AND THUNDERSTORMS TUESDAY AND WEDNESDAY...AS A WEAK
BOUNDARY LIFTS NORTH ACROSS NORTHERN MICHIGAN.
&&
.UPDATE...
ISSUED AT 700 PM EDT SAT JUN 30 2012
ASIDE FROM A FEW FAIR WX CU LINGERING EARLY THIS EVENING...SKC
REMAINS THE RULE ACROSS OUR ENTIRE CWA THANKS TO A BROAD AREA OF
HIGH PRESSURE HOLDING OVER THE WRN GREAT LAKES REGION. IR
SATELLITE LOOP DOES SHOW AN AREA OF SCT/BKN MID/HIGH CLOUDS OVER
WRN LAKE SUPERIOR...FAR WRN UPR MICHIGAN AND FAR NRN WISCONSIN
STEADILY TRACKING SE TOWARD OUR CWA. THIS AREA OF CLOUDS SHOULD
THIN A BIT AS IT MOVES INTO OUR CWA LATER THIS EVENING AND
OVERNIGHT...BUT WILL LIKELY RESULT IN A PARTLY CLOUDY SKY. CLOUDS
WILL NOT BEEN THICK ENOUGH TO SIGNIFICANTLY IMPACT THE RADIATIONAL
COOLING POTENTIAL AS WINDS BECOME CALM SHORTLY AFTER SUNSET. THUS...
STILL EXPECT OVERNIGHT LOWS TO COOL MAINLY INTO THE 50S. NICE MID
SUMMER SLEEPING TEMPS.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 259 PM EDT SAT JUN 30 2012
STALLED FRONT/MOISTURE AXIS STRETCHES FROM THE CENTRAL PLAINS
THROUGH THE OHIO VALLEY WITH WEAKISH HIGH PRESSURE AND W/NW FLOW
OVER THE GREAT LAKES. SPOTTY CONVECTION OCCURRING ALONG THE FRONT
BUT NOTHING TOO LARGE OR VIGOROUS AT THE MOMENT. FURTHER NORTH...CLEAR
TO PARTLY CLOUDY SKIES ACROSS NRN MICHIGAN WITH SOME CU OVER NE
LOWER AND UPPER MICHIGAN. REMNANTS OF OLD CONVECTION ADVANCING
ACROSS MINNESOTA WILL BRING SOME CLOUD COVER TO THE FORECAST AREA
LATER THIS EVENING.
TONIGHT...OTHER THAN BATCH OF MID AND HIGH CLOUD (REMNANT OF OLD
CONVECTION) ROLLING THROUGH THE REGION...ANOTHER QUIET NIGHT
EXPECTED. SIMILAR LOW TEMPS AS LAST NIGHT...UPPER 50S TO MIDDLE
60S.
SUNDAY...SUBTLE MID LEVEL COOLING EXPECTED TO TAKE PLACE BY SUNDAY
MORNING...WITH 700 MB TEMPS COOLING A GOOD 3 DEGREES. JUST ENOUGH
TO PRODUCE SOME MODEST AFTERNOON INSTABILITY ON THE ORDER OF
AROUND 500 J/KG MLCAPE. MODEST...BUT PERHAPS ENOUGH TO KICK OFF
SPOTTY SHOWERS OR THUNDERSTORMS OVER EASTER UPPER AND/OR NE LOWER
MICHIGAN WHERE LOW LEVEL CONVERGENCE WILL BE MAXIMIZED THANKS TO
LAKE BREEZES AND PREVAILING LIGHT WESTERLY FLOW. WILL MAINTAIN
INHERITED LOW CHANCE POPS.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 259 PM EDT SAT JUN 30 2012
PATTERN TALKED ABOUT YESTERDAY ALREADY IN THE PROCESS OF
UNFOLDING...WITH NOAM WATER VAPOR IMAGERY/12Z SOUNDING ANALYSIS
CONFIRMING HIGH RES RAP GUIDANCE OF SLOWLY BUILDING HIGH PLAINS
RIDGING BOOKENDED BY EAST AND WEST COAST TROUGH AXES. INITIAL
SCORCHER OF A HEAT DOME LOOKS TO REMAIN TO OUR SOUTHWEST...KEEPING
CONVECTIVE DEVELOPMENT AND PROPAGATION TIED ALONG TIGHT
MOISTURE/INSTABILITY GRADIENT OVER THE SOUTHERN LAKES. MOUNTING
EVIDENCE AT LEAST A PIECE OF CENTRAL PLAINS HEAT WILL EXPAND
(ATTEMPT TO?) NORTHEAST INTO THE LAKES MID AND LATE WEEK...WHICH FROM
A CONCEPTUAL AND PATTERN RECOGNITION PERSPECTIVE...SETS THE STAGE
FOR POTENTIAL MCS IMPACTS ACROSS THE NORTHERN LAKES. OF COURSE...
WHOLE FORECAST REMAINS RIDDLED WITH UNCERTAINTY...A MANIFESTATION OF
EXACT THERMAL GRADIENT CONCERNS AND CONVECTIVELY INDUCED COLD POOLS
ACTING UPON IT. FORECAST CHALLENGES REMAIN CENTERED ON TRYING TO
SHED SOME LIGHT ON THE ABOVE.
UNCERTAINTIES BEGIN IMMEDIATELY AS WEAK WAVE DIVES SOUTHEAST OVER
THE NORTHEAST LAKES MONDAY EVENING. SOME EVIDENCE THIS MAY SUPPORT
LINGERING SHOWERS/STORMS INTO THE EVENING...ALTHOUGH LOSS OF
DIURNALLY DRIVEN INSTABILITY AND LESS THAN STELLAR DYNAMIC
SUPPORT ARGUES OTHERWISE. IN ADDITION...ANY POTENTIAL UPSTREAM MCS
DEVELOPMENT LOOKS TO RIDE SOUTHEAST INTO THE SOUTHERN LAKES PER
PROPAGATION VECTORS. PERSONAL FORECAST PHILOSOPHY HAS TURNED IN RECENT
WEEKS GIVEN ONGOING DRY SPELL...AND SIMPLY NEED TO SEE MORE EVIDENCE
BEFORE "CLOUDING" THE FORECAST WITH ADDITIONAL LOW END POP CHANCES.
AT LEAST MORE CONFIDENCE SHOWER AND STORM THREAT WILL BE ON THE
INCREASE INTO MID WEEK AS HEAT EXPANDS NORTHEAST INTO THE WESTERN
LAKES...FORCING THERMAL/INSTABILITY GRADIENT INTO OUR AREA AS IT
DOES SO. THIS SHOULD ALLOW ANY LATE MONDAY NIGHT NORTHERN PLAINS
CONVECTIVE COMPLEX TO RIDE INTO THE AREA TUESDAY...WITH
POTENTIAL ADDITIONAL SHOWER AND STORM DEVELOPMENT INTO TUESDAY NIGHT
AND WEDNESDAY AS BOUNDARY ESSENTIALLY HANGS UP NEAR OR JUST NORTH OF
NORTHERN MICHIGAN. STILL SOME CONCERNS JUST HOW WIDESPREAD ANY
SHOWER AND STORM COVERAGE WILL BE...WITH LESS THAN IMPRESSIVE LOW
LEVEL JET TIED TO UPSTREAM CONVECTIVE DEVELOPMENT. EXACT MOVEMENT
ALSO RAISES SIGNIFICANT CONCERNS...WITH GUIDANCE OFTEN OVERLY
AMBITIOUS DRIVING STORMS NORTH IN SUCH A REGIME AS THEY ARE UNABLE
TO RESOLVE LOW LEVEL THERMAL ADJUSTMENTS OF COMBINED CONVECTIVE COLD
POOLS.
WON`T GET TOO SPECIFIC ABOUT LATER PERIODS OF THE EXTENDED...
ALTHOUGH THERE IS SOME EVIDENCE THERMAL RIDGE WILL CONTINUE TO
EXPAND NORTHEAST...PERHAPS BRINGING WIDESPREAD 90 DEGREE READINGS TO
NORTHERN LOWER MICHIGAN THURSDAY AND FRIDAY. ABOVE WOULD ALSO YIELD
A MORE CAPPED ATMOSPHERE...DISPLACING BETTER STORM POTENTIAL TO OUR
NORTH. VERY LOW CONFIDENCE SCENARIO OF A WEAK COLD FRONTAL PASSAGE
SATURDAY...BRINGING OUR NEXT RAIN THREAT. PLENTY OF TIME FOR FUTURE
ADJUSTMENTS TO THIS PERIOD.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 700 PM EDT SAT JUN 30 2012
VFR CONDITIONS WILL PERSIST THRU SUNDAY EVENING AS SURFACE HIGH
PRESSURE REMAINS THE DOMINANT WX FEATURE ACROSS MICHIGAN. WEAK
COOLING ALOFT COMBINED WITH DAYTIME HEATING WILL RESULT IN A SMALL
CHANCE OF SHRA/TSRA FOR PORTIONS OF NE LWR MICHIGAN...INCLUDING
APN...BY SUNDAY AFTERNOON. HOWEVER...THE CHANCE IS TOO SMALL TO
INCLUDE IN THE TAF FOR NOW. WINDS WILL BECOME LIGHT/CALM SHORTLY
AFTER SUNSET THIS EVENING. LIGHT SYNOPTIC WINDS WILL ALLOW FOR
LAKE BREEZE DEVELOPMENT BY SUNDAY AFTERNOON.
&&
.MARINE...
ISSUED AT 259 PM EDT SAT JUN 30 2012
SOME OFFSHORE GUSTINESS THIS AFTERNOON...JUST SHY OF SMALL CRAFT
CRITERIA...WILL DIMINISH THIS EVENING. NO HEADLINES ANTICIPATED.
LIGHTER WINDS ON SUNDAY...AND LAKE BREEZES SHOULD DEVELOP ALONG
ALL SHORELINES.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...MR
SYNOPSIS...SR
SHORT TERM...BA
LONG TERM...MB
AVIATION...MR
MARINE...BA
AREA FORECAST DISCUSSION
NWS GAYLORD MI
347 PM EDT SAT JUN 30 2012
.SYNOPSIS...
ISSUED AT 259 PM EDT SAT JUN 30 2012
THE GREAT LAKES WILL BE BETWEEN SYSTEMS INTO THE MIDDLE OF THE
UPCOMING WORK WEEK...AS A WEAK STORM SYSTEM SLOWLY LIFTS INTO
QUEBEC...WHILE WEAK HIGH PRESSURE BUILDS OVER THE STATE. THIS
PATTERN WILL GENERATE SEASONAL SUMMER TIME WEATHER...ACROSS NORTHERN
MICHIGAN THROUGH THE FOURTH OF JULY HOLIDAY. THERE IS A SMALL CHANCE
OF SHOWERS AND THUNDERSTORMS TUESDAY AND WEDNESDAY...AS A WEAK
BOUNDARY LIFTS NORTH ACROSS NORTHERN MICHIGAN.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 259 PM EDT SAT JUN 30 2012
STALLED FRONT/MOISTURE AXIS STRETCHES FROM THE CENTRAL PLAINS
THROUGH THE OHIO VALLEY WITH WEAKISH HIGH PRESSURE AND W/NW FLOW
OVER THE GREAT LAKES. SPOTTY CONVECTION OCCURRING ALONG THE FRONT
BUT NOTHING TOO LARGE OR VIGOROUS AT THE MOMENT. FURTHER NORTH...CLEAR
TO PARTLY CLOUDY SKIES ACROSS NRN MICHIGAN WITH SOME CU OVER NE
LOWER AND UPPER MICHIGAN. REMNANTS OF OLD CONVECTION ADVANCING
ACROSS MINNESOTA WILL BRING SOME CLOUD COVER TO THE FORECAST AREA
LATER THIS EVENING.
TONIGHT...OTHER THAN BATCH OF MID AND HIGH CLOUD (REMNANT OF OLD
CONVECTION) ROLLING THROUGH THE REGION...ANOTHER QUIET NIGHT
EXPECTED. SIMILAR LOW TEMPS AS LAST NIGHT...UPPER 50S TO MIDDLE
60S.
SUNDAY...SUBTLE MID LEVEL COOLING EXPECTED TO TAKE PLACE BY SUNDAY
MORNING...WITH 700 MB TEMPS COOLING A GOOD 3 DEGREES. JUST ENOUGH
TO PRODUCE SOME MODEST AFTERNOON INSTABILITY ON THE ORDER OF
AROUND 500 J/KG MLCAPE. MODEST...BUT PERHAPS ENOUGH TO KICK OFF
SPOTTY SHOWERS OR THUNDERSTORMS OVER EASTER UPPER AND/OR NE LOWER
MICHIGAN WHERE LOW LEVEL CONVERGENCE WILL BE MAXIMIZED THANKS TO
LAKE BREEZES AND PREVAILING LIGHT WESTERLY FLOW. WILL MAINTAIN
INHERITED LOW CHANCE POPS.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 259 PM EDT SAT JUN 30 2012
PATTERN TALKED ABOUT YESTERDAY ALREADY IN THE PROCESS OF
UNFOLDING...WITH NOAM WATER VAPOR IMAGERY/12Z SOUNDING ANALYSIS
CONFIRMING HIGH RES RAP GUIDANCE OF SLOWLY BUILDING HIGH PLAINS
RIDGING BOOKENDED BY EAST AND WEST COAST TROUGH AXES. INITIAL
SCORCHER OF A HEAT DOME LOOKS TO REMAIN TO OUR SOUTHWEST...KEEPING
CONVECTIVE DEVELOPMENT AND PROPAGATION TIED ALONG TIGHT
MOISTURE/INSTABILITY GRADIENT OVER THE SOUTHERN LAKES. MOUNTING
EVIDENCE AT LEAST A PIECE OF CENTRAL PLAINS HEAT WILL EXPAND
(ATTEMPT TO?) NORTHEAST INTO THE LAKES MID AND LATE WEEK...WHICH FROM
A CONCEPTUAL AND PATTERN RECOGNITION PERSPECTIVE...SETS THE STAGE
FOR POTENTIAL MCS IMPACTS ACROSS THE NORTHERN LAKES. OF COURSE...
WHOLE FORECAST REMAINS RIDDLED WITH UNCERTAINTY...A MANIFESTATION OF
EXACT THERMAL GRADIENT CONCERNS AND CONVECTIVELY INDUCED COLD POOLS
ACTING UPON IT. FORECAST CHALLENGES REMAIN CENTERED ON TRYING TO
SHED SOME LIGHT ON THE ABOVE.
UNCERTAINTIES BEGIN IMMEDIATELY AS WEAK WAVE DIVES SOUTHEAST OVER
THE NORTHEAST LAKES MONDAY EVENING. SOME EVIDENCE THIS MAY SUPPORT
LINGERING SHOWERS/STORMS INTO THE EVENING...ALTHOUGH LOSS OF
DIURNALLY DRIVEN INSTABILITY AND LESS THAN STELLAR DYNAMIC
SUPPORT ARGUES OTHERWISE. IN ADDITION...ANY POTENTIAL UPSTREAM MCS
DEVELOPMENT LOOKS TO RIDE SOUTHEAST INTO THE SOUTHERN LAKES PER
PROPAGATION VECTORS. PERSONAL FORECAST PHILOSOPHY HAS TURNED IN RECENT
WEEKS GIVEN ONGOING DRY SPELL...AND SIMPLY NEED TO SEE MORE EVIDENCE
BEFORE "CLOUDING" THE FORECAST WITH ADDITIONAL LOW END POP CHANCES.
AT LEAST MORE CONFIDENCE SHOWER AND STORM THREAT WILL BE ON THE
INCREASE INTO MID WEEK AS HEAT EXPANDS NORTHEAST INTO THE WESTERN
LAKES...FORCING THERMAL/INSTABILITY GRADIENT INTO OUR AREA AS IT
DOES SO. THIS SHOULD ALLOW ANY LATE MONDAY NIGHT NORTHERN PLAINS
CONVECTIVE COMPLEX TO RIDE INTO THE AREA TUESDAY...WITH
POTENTIAL ADDITIONAL SHOWER AND STORM DEVELOPMENT INTO TUESDAY NIGHT
AND WEDNESDAY AS BOUNDARY ESSENTIALLY HANGS UP NEAR OR JUST NORTH OF
NORTHERN MICHIGAN. STILL SOME CONCERNS JUST HOW WIDESPREAD ANY
SHOWER AND STORM COVERAGE WILL BE...WITH LESS THAN IMPRESSIVE LOW
LEVEL JET TIED TO UPSTREAM CONVECTIVE DEVELOPMENT. EXACT MOVEMENT
ALSO RAISES SIGNIFICANT CONCERNS...WITH GUIDANCE OFTEN OVERLY
AMBITIOUS DRIVING STORMS NORTH IN SUCH A REGIME AS THEY ARE UNABLE
TO RESOLVE LOW LEVEL THERMAL ADJUSTMENTS OF COMBINED CONVECTIVE COLD
POOLS.
WON`T GET TOO SPECIFIC ABOUT LATER PERIODS OF THE EXTENDED...
ALTHOUGH THERE IS SOME EVIDENCE THERMAL RIDGE WILL CONTINUE TO
EXPAND NORTHEAST...PERHAPS BRINGING WIDESPREAD 90 DEGREE READINGS TO
NORTHERN LOWER MICHIGAN THURSDAY AND FRIDAY. ABOVE WOULD ALSO YIELD
A MORE CAPPED ATMOSPHERE...DISPLACING BETTER STORM POTENTIAL TO OUR
NORTH. VERY LOW CONFIDENCE SCENARIO OF A WEAK COLD FRONTAL PASSAGE
SATURDAY...BRINGING OUR NEXT RAIN THREAT. PLENTY OF TIME FOR FUTURE
ADJUSTMENTS TO THIS PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 157 PM EDT SAT JUN 30 2012
SOLID VFR CONDITIONS THROUGH THE TAF FORECAST PERIOD WITH JUST
SOME HIGH BASED SCT CU IMPACTING APN. SOME GUSTINESS AT PLN AND
APN THIS AFTERNOON...LAKE BREEZES AT TVC. WINDS DIMINISH THIS
EVENING AND WILL BE LIGHT (UNDER 10 KNOTS) ON SUNDAY.
&&
.MARINE...
ISSUED AT 259 PM EDT SAT JUN 30 2012
SOME OFFSHORE GUSTINESS THIS AFTERNOON...JUST SHY OF SMALL CRAFT
CRITERIA...WILL DIMINISH THIS EVENING. NO HEADLINES ANTICIPATED.
LIGHTER WINDS ON SUNDAY...AND LAKE BREEZES SHOULD DEVELOP ALONG
ALL SHORELINES.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
SYNOPSIS...SR
SHORT TERM...BA
LONG TERM...MB
AVIATION...BA
MARINE...BA
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1206 PM CDT SAT JUN 30 2012
.UPDATE...
ISSUED AT 954 AM CDT SAT JUN 30 2012
QUICK UPDATE TO ADD POPS ACROSS PORTIONS OF SW IL TO ACCOUNT FOR
ONGOING SHRA. RUC PICKS UP ON THIS AREA OF PRECIP THIS MORNING
WITH THE FORCING WEAKENING OVER THE NEXT COUPLE OF HOURS. WITH
ANOTHER OUTFLOW MOVING SWD FROM CONVECTION FURTHER N...AM NOT
CONFIDENT THIS CONVECTION WILL DIMINISH AS QUICKLY AS THE RUC
SUGGESTS. HOWEVER...IT IS UNLIKELY THAT ANY SHRA WILL DEVELOP
FURTHER W AND THE ONGOING SHRA WILL LIKELY CONTINUE TO MOVE EWD
AND EVENTUALLY MOVE OUT OF THE CWA. HAVE THEREFORE ONLY KEPT THESE
POPS FOR THE MORNING HOURS.
REGARDLESS OF THIS PRECIP...BELIEVE TEMPS ARE STILL ON TRACK AS
THE PRECIP WILL LIKELY ONLY HELP RAISE DEWPOINTS AND SLIGHTLY
LOWER TEMPS.
TILLY
&&
.SHORT TERM...
ISSUED AT 329 AM CDT SAT JUN 30 2012 (TODAY)
AN OUTFLOW BOUNDARY FROM ORGANIZED CONVECTION ACROSS ERN IA AND NRN
IL HAS DROPPED SWD TO JUST S OF PPQ EARLY THIS MRNG. THERE WERE A
FEW SMALL SHOWERS ALONG THIS BOUNDARY ACROSS W CNTRL IL BUT THESE
HAVE SINCE DISSIPATED. WILL INCLUDE LOW CHANCE OR SLIGHT CHANCE
POPS TODAY ACROSS NERN MO AND W CNTRL IL WITH ADDITIONAL CONVECTION
POSSIBLE ALONG THESE OUTFLOW BOUNDARIES AND AS A WEAK SYNOPTIC FRONT
DROPS SWD INTO EXTREME NRN MO AND CNTRL IL AS A WEAK SFC RIDGE
BUILDS SEWD THROUGH THE NRN PLAINS AND INTO THE GREAT LAKES REGION
THIS AFTN. THE ATMOSPHERE SHOULD BE TOO CAPPED FOR ANY CONVECTION S
OF THIS AREA TODAY. BECAUSE OF SOME MID-HIGH LEVEL CLOUDINESS HIGH
TEMPERATURES TODAY WILL LIKELY BE SLIGHTLY COOLER THAN FRIDAY
ACROSS PORTIONS OF NERN MO AND W CNTRL IL. FURTHER S LITTLE CLOUD
COVER IS EXPECTED WITH SIMILAR MAX TEMPERATURES EXPECTED TODAY
COMPARED TO YESTERDAY...LIKELY RANGING FROM 100 TO 105 DEGREES. AN
EXCESSIVE HEAT WARNING CONTINUES FOR THE ST LOUIS METRO AREA AND
PORTIONS OF SERN MO AND SWRN IL WITH A HEAT ADVISORY W OF THIS
REGION FOR THE REST OF OUR FORECAST AREA.
GKS
&&
.LONG TERM...
ISSUED AT 329 AM CDT SAT JUN 30 2012 (TONIGHT TO FRIDAY)
MAIN QUESTION WILL BE HOW LOCATION OF EFFECTIVE FRONT AND
ATTENDANT CLOUDS/SLIGHT RAIN CHANCES WILL AFFECT ONGOING HEAT
WAVE. DO NOT THINK THAT IT WILL BE ENOUGH TO PREVENT HEAT INDEX
READINGS FROM CLIMBING INTO THE 100-106 RANGE BOTH TOMORROW AND
MONDAY. PLAN ON EXTENDING CURRENT HEAT WARNINGS/ADVISORIES INTO
MONDAY. WILL ALSO ADD STE. GENEVIEVE...ST. FRANCOIS AND MADISON
COUNTIES TO THE EXCESSIVE HEAT WARNING. FARMINGTON`S HEAT INDEX
WAS 106 YESTERDAY...AND WILL LIKELY BE NEAR 105 TODAY AND
TOMORROW.
THINK THAT CHANCE OF THUNDERSTORMS MENTIONED ABOVE WILL LINGER
INTO EARLY EVENING OVER FAR NORTHEAST MISSOURI INTO WEST CENTRAL
ILLINOIS ALONG STATIONARY FRONT. THIS FRONT DOES LOOK TO MOVE
NORTH LATE THIS EVENING INTO SUNDAY AS UPPER RIDGE BEGINS TO BUILD
OVER THE AREA...SO WILL ONLY KEEP SLIGHT CHANCES FOR THUNDERSTORMS
GOING OVER THE FAR NORTHERN PART OF THE CWA INTO EARLY SUNDAY.
THINK THAT THE REST OF THE WEEKEND WILL BE MAINLY DRY AS THE FRONT
MOVES TO THE NORTH. INTERESTINGLY...THE NAM DEVELOPS A BULLSEYE OF A
QUARTER OF AN INCH OF RAINFALL OVER THE SOUTHERN CWA DURING SUNDAY
AFTERNOON WHERE THE ATMOSPHERE WILL BECOME VERY UNSTABLE AND
UNCAPPED IN AN AREA OF WEAK LOW LEVEL CONVERGENCE. THIS SEEMS
UNLIKELY GIVEN THAT THE AREA WILL BE UNDER THE UPPER RIDGE SO WILL
LEAVE THE AREA DRY FOR NOW.
STILL EXPECT TEMPERATURES TO REACH THE TRIPLE DIGITS BOTH SUNDAY AND
MONDAY GIVEN DEEP MIXING TO 700MB AND 850MB TEMPERATURES STAYING IN
THE 22-25C RANGE. STILL EXPECT DEWPOINTS TO FALL BACK INTO THE
UPPER 50S AND LOWER 60S TO THE SOUTH OF I-70 BOTH DAYS...BUT THE
BETTER PERFORMING NAM MOS GUIDANCE HAS HIGHS IN THE 99-105 RANGE.
FARTHER NORTH...DEWPOINTS WILL BE HIGHER CLOSER THE RETREATING FRONT
WITH SLIGHTLY COOLER TEMPERATURES KEEPING HEAT INDEX READINGS AROUND
100 DEGREES.
MEDIUM RANGE MODELS ARE SHOWING SOME DISAGREEMENT NEXT WEEK WHICH
LOWERS THE OVERALL CONFIDENCE FOR THE HOLIDAY WEEK FORECAST. THE
MODELS DO DEPICT A GRADUAL RISE IN HEIGHTS AS THE UPPER HIGH NOW
OVER THE SOUTHWESTERN CONUS MOVES TO THE NORTHEAST. THE GFS
DEVELOPS SOME LIGHT QPF OVER IL ON EASTERN PERIPHERY OF THE BUILDING
HIGH. THE NEW ECMWF BRINGS A TROPICAL SYSTEM UP INTO SOUTHERN MO ON
TUESDAY AHEAD OF THE HIGH. WILL DISCOUNT BOTH OF THESE SOLUTIONS
FOR NOW WITH THE BUILDING RIDGE AND GO WITH CONTINUITY WHICH MEANS
STAYING WITH THE HOT AND DRY FORECAST. BOTH MODELS STILL HAVE
850MB TEMPS IN THE 22-24C RANGE WHICH SUPPORT HIGHS NEAR 100.
BRITT
&&
.AVIATION...
ISSUED AT 1202 PM CDT SAT JUN 30 2012
VFR AND DRY THRU THE PERIOD EXCEPT FOR POSSIBLY UIN. STATIONARY
FNT REMAINS ACROSS SRN IA AND CNTL IL. ANOTHER MCS IS EXPECTED
TONIGHT ALONG THIS FNT WHICH MAY PUSH S AND IMPACT UIN.
HOWEVER...BELIEVE TSRA WILL BE ISOD TO SCT AS FAR S AS UIN AND
WILL KEEP TAF DRY FOR NOW. OTHERWISE...SLY TO SWLY WINDS THRU THE
PERIOD WITH SOME HIGHER GUSTS THIS AFTERNOON AROUND 18 KTS AT
COU/UIN.
SPECIFICS FOR KSTL...VFR AND DRY THRU THE PERIOD. SW WINDS WILL
BECOME LIGHT AND VRB TONIGHT AND PICK UP AGAIN SUN MORNING
BECOMING MORE WLY WITH SPEEDS AROUND 10 KTS OR LESS.
TILLY
&&
.FIRE WEATHER...
ISSUED AT 329 AM CDT SAT JUN 30 2012
STILL PLAN ON GOING WITH HEIGHTENED FIRE DANGER WORDING FOR TODAY AND
SUNDAY. WINDS WILL STAY BELOW 15 MPH OVER THE SOUTHERN PART OF
THE CWA WHICH IS THE MOST LIKELY AREA TO HAVE MINIMUM RELATIVE
HUMIDITY VALUES FALL BELOW 20 PERCENT. FORECAST 10 HOUR DEAD
FUELS WILL BE 8 PERCENT OR LESS. THESE CONDITIONS WILL CONTINUE INTO
NEXT WEEK. WILL CONTINUE TO USE APPROPRIATE WORDING IN THE FIRE
WEATHER FORECAST...SPECIAL WEATHER STATEMENTS...AND HAZARDOUS
WEATHER OUTLOOK.
BRITT
&&
.CLIMATE...
ISSUED AT 329 AM CDT SAT JUN 30 2012
RECORD HIGHS
DATE ST. LOUIS COLUMBIA QUINCY
----------------------------------------------
JUNE 30 103(1931) 103(1901) 103(1931)
JULY 01 105(1980) 110(1980) 104(1930)
JULY 02 101(1933) 102(1901) 103(1934)
JULY 03 101(1934) 104(1901) 104(1911)
JULY 04 102(1990) 106(1901) 103(1936)
JULY 05 102(1938) 105(1911) 104(1911)
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...HEAT ADVISORY UNTIL 7 PM CDT MONDAY FOR AUDRAIN MO-BOONE MO-
CALLAWAY MO-COLE MO-CRAWFORD MO-FRANKLIN MO-GASCONADE MO-
IRON MO-KNOX MO-LEWIS MO-LINCOLN MO-MARION MO-MONITEAU MO-
MONROE MO-MONTGOMERY MO-OSAGE MO-PIKE MO-RALLS MO-REYNOLDS
MO-SHELBY MO-WARREN MO-WASHINGTON MO.
EXCESSIVE HEAT WARNING UNTIL 7 PM CDT MONDAY FOR JEFFERSON MO-
MADISON MO-ST. CHARLES MO-ST. FRANCOIS MO-ST. LOUIS CITY MO-
ST. LOUIS MO-STE. GENEVIEVE MO.
IL...HEAT ADVISORY UNTIL 7 PM CDT MONDAY FOR ADAMS IL-BROWN IL-
CALHOUN IL-PIKE IL.
EXCESSIVE HEAT WARNING UNTIL 7 PM CDT MONDAY FOR BOND IL-CLINTON
IL-FAYETTE IL-GREENE IL-JERSEY IL-MACOUPIN IL-MADISON IL-
MARION IL-MONROE IL-MONTGOMERY IL-RANDOLPH IL-ST. CLAIR IL-
WASHINGTON IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1244 PM CDT SAT JUN 30 2012
.AVIATION...18Z TAFS FOR KLBF AND KVTN.
TIMING AND ULTIMATE COVERAGE OF TSRA IS THE FCST PROBLEM OF THE
DAY. SHORT RANGE AND CONVECTION ALLOWING MODELS HAVE A VARIETY OF
IDEAS ON HOW CONVECTION WILL DEVELOP THIS AFTERNOON THOUGH NONE
SEEM TO HAVE IT HANDLED WELL AS OF 17Z. THOUGH TCU/CB CLOSE TO
KLBF ATTM DETAILS ARE HARD TO SEE DUE TO SMOKE AND RESULTING HAZE FROM
SERN WY FIRE CONBINED WITH HIGH SFC DEW POINTS.
REGARDLESS...DEVELOPING TSRA DOES HAVE CG LIGHTNING INCREASING AND
APPEARS TO BE THE BOUNDARY BETWEEN THE MOIST AIR IN THE EAST AND
THE PUSH OF DRY AIR ASSOCIATED WITH SHORT WAVE DIVING SEWD FROM SW
SD. BELIEVE THIS TO BE THE INITIAL DEVELOPMENT WHICH WILL HAVE THE
POTENTIAL TO EXPAND IN COVERAGE AND INTENSITY. FCST SOUNDINGS AND
RECENT TSRA HISTORY SUGGESTS GUSTY WINDS SHOULD BE EXPECTED WITH
ANY TSRA...AND EVEN CURRENT WEAK RETURNS ON KLNX STILL SHOWING
OUTFLOW BOUNDARIES. AS FOR KVTN...MAIN TSRA COVERAGE INITIALLY
SHOULD BE SOUTH OF THE TERMINAL.
LATER...A MORE SIGNIFICANT SHORT WAVE APPEARS TO BE PROGRESSING
AROUND FLATTENED UPPER RIDGE ATTM AND IS MOVING INTO NWRN CO.
RESULTING RESPONSE WILL BE FOR AN INCREASING LOW LEVEL JET TONIGHT
WHICH SHOULD INCREASE COVERAGE OF REMAINING TSRA BY EVENING.
QUESTION REMAINS IF THIS WILL OCCUR EAST OF KLBF AND KVTN
TERMINALS. CURRENT FCST IS DESIGNED SUCH THAT BETTER COVERAGE WILL
HAPPEN EAST OF THE TAF SITES...THOUGH CONFIDENCE IN ANY ONE SOLUTION
IS BELOW AVERAGE AT THIS POINT. IF WINDS GO LIGHT IN THE KLBF
VCNTY OVERNIGHT WILL HAVE TO MONITOR FOR POTENTIAL OF LLWS.
&&
.PREV DISCUSSION... /ISSUED 846 AM CDT SAT JUN 30 2012/
UPDATE...UPDATED FCST TO INCLUDE MENTION OF ISOLATED
THUNDERSTORMS IN NORTHEAST ZONES AS WELL AS SOUTHEAST ZONES.
APPEARS ELEVATED INSTABILITY AHEAD OF APPROACHING SHORTWAVE
ROUNDING FLATTENED RIDGE WORKING TO PRODUCE ISOLATED STORMS.
ADDITIONAL DEVELOPMENT POSSIBLE THIS MORNING INTO AFTERNOON.
PREV DISCUSSION... /ISSUED 406 AM CDT SAT JUN 30 2012/
DISCUSSION...
UPPER LEVEL RIDGING REMAINS IN PLACE ACROSS THE CENTRAL
PLAINS...WITH LONGWAVE TROUGHS OVER THE EASTERN PACIFIC AND
EASTERN CANADA. THE LOCAL AREA WAS IN AN AREA OF SUBSIDENCE BEHIND
A SYSTEM WHICH HAD MOVED INTO IOWA/ILLINOIS. WATER VAPOR IMAGERY
SHOWED THIS PATTERN...AND ALSO PICKED UP ON A SHORTWAVE TROUGH
OVER WESTERN WYOMING.
AT THE SURFACE...DEWPOINTS ACROSS THE FORECAST AREA RANGED FROM
THE 40S IN THE EASTERN PANHANDLE TO AROUND 70 AT KLBF.
OBSERVATIONS INDICATED A BOUNDARY FROM AROUND KIEN TO KOGA THROUGH
KMCK AND INTO NORTH CENTRAL KANSAS WITH EASTERLY WINDS ON THE EAST
SIDE OF THE BOUNDARY.
HOW TODAY/S WEATHER PANS OUT WILL DEPEND ON IF CONVECTION DEVELOPS
AHEAD OF THE WYOMING SHORTWAVE THIS MORNING. THE 30.00Z AND 30.06Z
NAM FIRE STORMS OVER THE PANHANDLE BETWEEN 12Z AND 15Z AND THE
RAPID REFRESH DOES SHOW SOME INDICATIONS OF CONVECTION IN THESE
AREAS...BUT THESE ARE THE ONLY MODELS TO DO SO. THE GFS/EC/GEM
ARE ALL DRY WHILE THE LATEST HRRR AND DOES DEVELOP STORMS...BUT
KEEPS THEM OVER SOUTH DAKOTA. ALTHOUGH THE NAM IS THE
OUTLIER...THERE IS ELEVATED INSTABILITY AND MOISTURE IN THE AREA
AND WITH THE WAVE MOVING ACROSS THE REGION...DON/T WANT TO
DISCOUNT ITS OUTPUT. THE ACTIVITY OVER WYOMING IS VERY HIGH BASED
/AROUND 11K FEET/. WILL ASSUME THAT TREND WILL CONTINUE WITH THE
MORNING HOURS BRINGING SOME SCATTERED RADAR RETURNS WITH NO
MEASURABLE RAIN TO THE NORTHWEST PART OF THE FORECAST AREA. THERE
COULD BE AN ISOLATED LIGHTNING STRIKES...AND COLLAPSING
SHOWERS/STORMS COULD CAUSE SOME GUSTY WINDS. FOR THE
AFTERNOON...PEAK HEATING...INSTABILITY AND A WEAK SHORTWAVE
PASSING SHOULD BE ENOUGH FOR STORMS TO DEVELOP. THESE STORMS TOO
WILL BE HIGH BASED AND WITH QUITE A BIT OF DRY AIR IN THE BOUNDARY
LAYER DON/T HAVE A LOT OF CONFIDENCE ON THE COVERAGE OF MEASURABLE
RAINFALL. WITH THESE CHANCES AND AS THE LOW LEVEL JET PICKS UP
THIS EVENING...KEPT CHANCES IN THE FORECAST AT THROUGH TONIGHT.
NOT A MAJOR THREAT FOR SEVERE STORMS AS THE WARMTH OF THE LAYER
ALOFT SHOULD PRECLUDE THE CHANCES FOR LARGE HAIL TO MAKE IT TO THE
GROUND. THERE IS 30 TO 45KTS OF DEEP LAYER SHEAR SO CAN/T DISCOUNT
AN ISOLATED ORGANIZED STORM BUT THINKING THE PRIMARY THREAT WILL
BE STRONG WINDS. DID DROP HIGH TEMPERATURES BY A FEW DEGREES TODAY
DUE MAINLY TO THE HIGHER CLOUD COVER EXPECTED. BUT IT WILL STILL
BE VERY WARM WITH HIGHS IN THE MID TO UPPER 90S MOST LOCATIONS.
THE UPPER LEVEL TROUGH OVER THE PACIFIC WILL MOVE ONSHORE
TONIGHT...WHICH WILL BEGIN TO AMPLIFY THE FLOW AGAIN WITH THE
RIDGE BUILDING NORTH ACROSS THE PLAINS THROUGH MONDAY. THE MODELS
ARE TRYING TO PUSH A SHORTWAVE TROUGH OVER THE RIDGE ACROSS
WYOMING AND SOUTH DAKOTA ON SUNDAY SO DEVELOP PRECIPITATION OVER
THE AREA. WARM AIR ALOFT MAY KEEP SOME OF THIS FROM HAPPENING SO
MAY HAVE HIGHER CHANCES OVER THE HIGHER TERRAIN BUT WILL KEEP A
SLIGHT CHANCE OVER THE NORTHEASTERN COUNTIES AS WELL. THEN MONDAY
WILL BE DRY AS NEBRASKA SITS RIGHT UNDER THE RIDGE. FOR
TEMPERATURES...FORECAST SOUNDINGS SHOWING FULL MIXING ON SUNDAY
AND MONDAY. DID TAKE INTO ACCOUNT HIGHER CLOUD COVER ESPECIALLY OVER
THE NORTHERN PARTS OF THE FORECAST AREA SUNDAY SO DIDN/T GO AS
WARM IN THE FORECAST IN THOSE AREAS. STILL EXPECTING MID TO
UPPER 90S THOUGH. MONDAY SHOULD BE A BIT WARMER WITH MUCH OF THE
AREA LOOKING TO BE INTO THE TRIPLE DIGITS AGAIN.
NO END IS IN SITE FOR THE WARMTH AS THE MODELS KEEP THE RIDGE IN
PLACE THROUGH THE REMAINDER OF NEXT WEEK. THIS LEADS TO LOW
CHANCES FOR RAIN AND HOT TEMPERATURES. HIGHS LOOK TO BE IN THE MID
TO UPPER 90S AND SOME DAYS HITTING 100 DEGREES OR BETTER. BY
FRIDAY EVENING THE RIDGE MAY SHIFT EAST FAR ENOUGH FOR STORMS
DEVELOPING OVER COLORADO AND WYOMING TO MOVE INTO THE EASTERN
PANHANDLE. BUT UNTIL THEN THE FORECAST LOOKS DRY FOR MUCH OF NEXT
WEEK.
FIRE WEATHER...
THE CURRENT FORECAST DOESN/T HAVE ANY DAYS WITH CONDITIONS
REACHING CRITICAL FIRE WEATHER CRITERIA. SUNDAY MAY BE CLOSE WITH
BREEZY SOUTHERLY WINDS AND RELATIVE HUMIDITY FORECAST BETWEEN 15
AND 20 PERCENT OVER SOUTHWEST NEBRASKA. WILL NEED TO CONTINUE TO
WATCH FOR FIRE POTENTIAL OVER THE NEXT WEEK AS THE HEAT AND DRY
WEATHER CONTINUE.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AVIATION...JWS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1240 PM CDT SAT JUN 30 2012
.AVIATION...18Z KGRI TAF. WHILE VFR CONDITIONS ARE FORECAST FOR
THE TAF PERIOD...THERE REMAINS A CHANCE FOR SHOWERS AND
THUNDERSTORMS THIS AFTERNOON AND EVENING. A FEW OF THESE STORMS
MAY AFFECT THE TAF SITE AND MAY BECOME STRONG TO SEVERE WITH LARGE
HAIL AND DAMAGING WINDS BEING THE MAIN THREATS. WHILE TIMING AND
PLACEMENT OF THUNDERSTORMS REMAINS A BIT UNCERTAIN...DECIDED TO GO
WITH A TEMPO GROUP MAINLY AFTER 0Z BASED ON MODEL TIME HEIGHTS.
OTHERWISE...LIGHT WINDS WILL GRADUALLY SHIFT TO THE SOUTH WITH
SCATTERED MID LEVEL CLOUDS EXPECTED.
&&
.PREV DISCUSSION... /ISSUED 940 AM CDT SAT JUN 30 2012/
UPDATE...WENT AHEAD AND PULLED MENTION OF FOG FROM THE
FORECAST...AS VISIBILITIES IN SURFACE OBSERVATIONS HAVE BEGUN TO
INCREASE ACROSS THE REGION. ALSO PER RADAR IMAGERY SOME MID LEVEL
RETURNS HAVE BEGUN TO SHIFT EASTWARD ACROSS PORTIONS OF FURNAS AND
GOSPER COUNTIES THIS MORNING. ADDED SLIGHT CHANCES FOR RAIN
SHOWERS ACROSS THE FAR WEST...ALTHOUGH NOT EXPECTING MUCH MORE
THAN A SPRINKLE.
PREV DISCUSSION... /ISSUED 646 AM CDT SAT JUN 30 2012/
UPDATE...11Z SURFACE ANALYSIS INDICATES A STATIONARY SURFACE
BOUNDARY EXTENDING FROM NEAR KGLD...TO NEAR KHJH...TO JUST SOUTH
OF KLNK. A NORTHEASTERLY LOW LEVEL WIND FIELD AND SUFFICIENT POOLING
OF LOW LEVEL MOISTURE IS NOTED JUST NORTH/NORTHWEST OF THIS
BOUNDARY...WITH FOG NOW DEVELOPING ALONG AN AXIS WHICH EXTENDS
FROM WEST TO EAST SOUTH OF I-80 AND NORTH OF HIGHWAY 6. MOST
LOCATIONS ARE EXPERIENCING VISIBILITY RESTRICTIONS OF 2-5
MILES...BUT WITHIN THE PAST HOUR THREE SITES INCLUDING KHSI...KEAR
AND KHDE HAVE FALLEN 1/4SM OR LESS. WENT AHEAD AND UPDATED THE
FORECAST TO INCLUDE FOG MENTION SOUTH OF I-80 AND NORTH OF HIGHWAY
6 THROUGH 14Z. RAP ANALYSIS PROXIMITY SOUNDINGS FROM ACROSS CENTRAL
PORTIONS OF OUR CWA INDICATE THIS MOIST BOUNDARY LAYER IS VERY
SHALLOW AND SHOULD MIX OUT QUICKLY ONCE DIABATIC HEATING
INTENSIFIES IN THE NEXT HOUR OR SO. GIVEN ALL THIS...WILL HOLD OFF
FROM ANY FOG HEADLINES FOR NOW...BUT DID INCLUDE RESTRICTED
VISIBILITIES IN THE HWO AND INTRODUCED A NOW-CAST.
PREV DISCUSSION... /ISSUED 422 AM CDT SAT JUN 30 2012/
SHORT TERM...TODAY THROUGH MONDAY NIGHT. HOT WEATHER WILL
CONTINUE TODAY...BUT THERE IS A SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS LATER THIS AFTERNOON THROUGH SUNDAY MORNING. MAINLY
DRY WEATHER CAN THEN BE EXPECTED SUNDAY AFTERNOON THROUGH THE END
OF THE SHORT TERM PERIOD MONDAY NIGHT.
TODAY...THERE WILL BE A SFC FRONTAL BOUNDARY LOCATED NEAR OR JUST
NORTH OF THE NEBRASKA KANSAS BORDER...WHICH WILL ACT AS A FOCUSING
MECHANISM FOR THUNDERSTORMS LATER THIS AFTERNOON. IN
ADDITION...THERE WILL BE A WEAK SHORT WAVE MOVING ACROSS THE
NORTHERN PLAINS. THE 00Z GFS...00Z ECMWF...AND 06Z NAM ALL INDICATE
THE POTENTIAL OF AFTERNOON AND EVENING THUNDERSTORMS. INSTABILITY
WILL BE HIGH BUT DEEP LAYER SHEAR WILL BE MARGINAL. STEERING WINDS
ARE WEAK AND THUNDERSTORMS WILL BE SLOW MOVERS WITH COVERAGE
SOMEWHAT ISOLATED. THE CHANCE OF PRECIPITATION THROUGH SUNDAY
MORNING IS FAIRLY LOW AT AROUND 20 PERCENT...BUT THIS APPEARS TO
STILL BE THE BEST SHOT OF PRECIPITATION OVER THE WEEK AHEAD. A FEW
THUNDERSTORMS COULD BECOME STRONG TO SEVERE GIVEN THE HIGH
INSTABILITY. HEAT INDEX VALUES THIS AFTERNOON WILL AGAIN NEAR BUT
REMAIN BELOW ADVISORY CATEGORY.
SUNDAY INTO MONDAY...THE SFC FRONT LIFTS NORTH SUNDAY MORNING
TAKING PRECIPITATION CHANCES NORTH AND OUT OF OUR AREA BY LATE
SUNDAY MORNING. SOUTH WINDS WILL INCREASE AND ACT TO PUMP
TEMPERATURES UP A FEW MORE DEGREES WITH SUNDAY EXPECTED TO BE
WARMER THAN SATURDAY...AND MONDAY SHOULD BE A BIT WARMER THAN
SUNDAY. HEAT INDEX VALUES ACROSS KANSAS ON MONDAY WILL BE RIGHT
NEAR THE 105 CRITERIA FOR ISSUING HEAT ADVISORIES.
LONG TERM...STARTING 12Z TUESDAY. UPPER LEVEL RIDGING WILL
CONTINUE TO PROMOTE LITTLE IN THE WAY OF KINEMATIC FORCING DURING
THE LONG TERM FORECAST PERIOD...THUS PRESENTING DRY CONDITIONS
TUESDAY THROUGH FRIDAY. LITTLE CHANGE IN THE LOW LEVEL AIRMASS
DURING THIS SAME TIME PERIOD SUGGESTS ABOVE-NORMAL TEMPERATURES
WILL ALSO PERSIST THROUGH THE LONG TERM FORECAST PERIOD...WITH
AFTERNOON HIGHS IN THE 90S TO LOW 100S AND OVERNIGHT LOW IN THE
70S.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1222 PM CDT SAT JUN 30 2012
.AVIATION...
18Z TAFS FOR KOMA...KOFK...KLNK
MAINLY VFR CONDS ARE EXPECTED THROUGH THE PERIOD. UPSTREAM SHORTWAVE
TROUGH WILL LEAD TO AN INCREASE IN SHRA/TSRA ACTIVITY THIS
AFTN/EVNG...BUT HITTING ONE OF THE TAF SITES IS STILL IN SOME DOUBT.
THIS WILL INITIALLY HAVE THE BEST CHC AT OFK AND WILL INCLUDE AN
AFTN TEMPO GROUP FOR SOME SHRA THERE AND WILL MONITOR FOR THE THREAT
OF THUNDER. OTHERWISE WILL INCLUDE SOME VCSH FOR BOTH OMA/LNK AND
WAIT FOR BETTER CONSISTENCY IN THE MODELS TO NAIL DOWN THE TIMING OF
ANY POSSIBLE THUNDER THERE. OTHERWISE IF IT DOES RAIN AT ANY OF THE
TAF SITES...WE COULD SEE SOME MVFR HZ TOWARD SUN MRNG. SRLY WINDS
ARE EXPECTED TO INCREASE ON SUN WITH A SCT MID LEVEL DECK.
BOUSTEAD
&&
.DISCUSSION...
SMALL AREA OF SHOWERS AND ISOLATED THUNDERSTORMS IS MOVING ACROSS
CENTRAL SD/CENTRAL NEB AND TOWARD NORTHEAST NEB. RAP ANALYSIS
INDICATES MID-LEVEL LAPSE RATES OF 9C AND AN AXIS OF 850MB
MOISTURE JUST AHEAD OF THE SHOWERS...INDICATING A SUPPORTIVE
ENVIRONMENT FOR SHOWERS TO PERSIST INTO NORTHEAST NEB FOR AT LEAST
ANOTHER COUPLE OF HOURS. HAVE ADDED A SMALL AREA OF ISOLATED
SHRA/ISO TS MENTION TO THE NORTHWESTERNMOST CWA.
MAYES
&&
PREV DISCUSSION... /ISSUED 320 AM CDT SAT JUN 30 2012/
DISCUSSION...
VERY SUBTLE WAVE MOVING THROUGH AREA HAS IGNITED ISOLATED STORMS
EARLY THIS MORNING...BUT ONLY IN A COUPLE OF COUNTIES IN OUR AREA
IN WEST CENTRAL IOWA. BELIEVE THAT ANY OF THIS ACTIVITY WOULD BE
EAST OF THE FORECAST AREA BY 6 AM.
MEANWHILE...STALLED SURFACE FRONT WILL REMAIN PARKED NEAR THE
NE/KS BORDER REGION TODAY...WHICH MAY PROVIDE A TRIGGER FOR
ISOLATED THUNDERSTORMS IN SOUTHEAST NEBRASKA LATER THIS AFTERNOON
THROUGH PEAK HEATING AS THE CAP WEAKENS. OTHERWISE...HIGH CLOUDS
WILL DRIFT ACROSS THE REGION FROM THE WEST TODAY...BUT IT SHOULD
STILL BE ANOTHER HOT DAY WITH HIGHS IN THE LOWER/MID 90S ALONG
WITH AN EASTERLY SURFACE FLOW. VERY OPPRESSIVE HUMIDITY OF RECENT
DAYS HAS MIXED OUT JUST A BIT...THUS HEAT INDEX VALUES TODAY...
WHILE STILL HOT...WILL BE JUST BELOW ADVISORY CRITERIA.
FOR TONIGHT...WITH THE SURFACE FRONT STILL IN THE AREA...AN
ISOLATED THUNDERSTORM MAY LINGER ALONG IT EARLY IN THE EVENING IN
SOUTHEAST NEBRASKA. OTHERWISE...A VERY SUBTLE WAVE MOVING THROUGH
THE ROCKIES COULD GENERATE CONVECTION ACROSS THE HIGH PLAINS WHICH
COULD MOVE INTO OUR LOCAL AREA BY MIDNIGHT AND BEYOND...ESPECIALLY
INTO NORTHEAST NEBRASKA NEBRASKA WHERE THE LOW LEVEL JET MAY BE
FOCUSED...THUS HAVE SLIGHTLY HIGHER POPS THERE TO ACCOUNT FOR A
POSSIBLE MCS THAT MAY ALSO DEVELOP ALONG THE NE/SD/IA BORDER AREA
LATE IN THE NIGHT AS WELL.
IF THE PREVIOUSLY MENTIONED MCS DOES DEVELOP...IT COULD LINGER
SUNDAY MORNING FOR AREAS NORTH OF I80. THEREAFTER...THE STALLED
FRONT DOES BEGIN TO LIFT THROUGH THE DAY SUNDAY AFTERNOON...WHICH
COULD TRIGGER ADDITIONAL ISOLATED THUNDERSTORMS THAT COULD LINGER
THROUGH SUNDAY EVENING AS THE FRONT CONTINUES TO LIFT NORTH OF THE
REGION.
FOR MONDAY THROUGH FRIDAY...THE UPPER RIDGE REBUILDS ACROSS THE
CENTRAL US WITH NO DISCERNIBLE FRONTAL BOUNDARIES IN OUR AREA
WITH CONTINUED SOUTH TO SOUTHWEST FLOW. THIS WILL RESULT IN A WEEK
OF VERY HOT AND DRY CONDITIONS INCLUDING THE INDEPENDENCE DAY
HOLIDAY. DAYTIME HIGHS WILL BE IN THE MID TO UPPER 90S EVERY
DAY...VERY NEAR 100 AT TIMES. HUMIDITY WILL NOT BE EXTREMELY
OPPRESSIVE...BUT WILL BE JUST ENOUGH TO RESULT IN DAILY HEAT INDEX
VALUES OF 100 TO 105 EVERY DAY...BUT GENERALLY BELOW ADVISORY
CRITERIA. THERE IS SOME HINT IN THE MODELS THAT THE RIDGE MAY
BREAK DOWN JUST A BIT BY NEXT WEEKEND ALLOWING FOR VERY SMALL
CHANCES FOR RAIN TO RETURN BY SATURDAY AND SUNDAY.
DEWALD
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
322 PM EDT SAT JUN 30 2012
.SYNOPSIS...
A FRONT ACROSS CENTRAL OHIO WILL REMAIN NEARLY STATIONARY THROUGH
EARLY MONDAY. THIS FRONT WILL EVENTUALLY MOVE NORTH INTO THE LOCAL
AREA MONDAY AS A WARM FRONT. A WEAK COLD FRONT IS EXPECTED TO MOVE
ACROSS THE REGION DURING THE MIDDLE PORTION OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
THE WEATHER ACROSS THE LOCAL AREA REMAINS QUIET THIS AFTERNOON.
LITTLE IN THE WAY OF CU HAS FORMED. THE MAIN BAROCLINIC ZONE HAS
PUSHED WELL SOUTH OF THE AREA. THIS FEATURE WILL LIKELY BE THE
FOCUS FOR ANY NEW DEVELOPMENT. WILL HAVE TO WATCH THE CLUSTER OF
STORMS OVER IL. IT IS POSSIBLE THAT THIS ACTIVITY COULD CLIP THE
SOUTHERN END OF THE AREA LATER THIS EVENING. NOT EXPECTING ANY
SEVERE WEATHER HOWEVER. HRRR MODEL CONTINUES TO SHOW NEW
DEVELOPMENT OVER THE LOCAL AREA THIS EVENING. THIS IS PROBABLY A
LITTLE OVERDONE BUT NOT COMFORTABLE GOING OUT WITH A DRY FORECAST
SO WILL MAINTAIN A SMALL MENTION. WILL STAY CLOSE TO GUIDANCE FOR
LOWS.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH WEDNESDAY NIGHT/...
NO MUCH CHANGE IN THE PATTERN DURING THE PERIOD. IT APPEARS THE
REGION WILL REMAIN UNSETTLED WITH HIGH DEWPOINTS AND TEMPS WITHIN
A FEW DEGREES OF 90 EACH OF THE NEXT SEVERAL DAYS. MODELS CONTINUE
TO SHOW A SERIES WEAK IMPULSES INTERACTING WITH THE SURFACE
STATIONARY FRONT. TOUGH TO KNOW WHICH OF THESE IMPULSES ARE LEGIT
AND WHICH ARE CONVECTIVE FEEDBACK. THINK THERE WILL BE A SMALL
CHANCE FOR STORMS SUNDAY AFTERNOON. PERHAPS THERE WI ILL BE A BETTER
CHANCE MONDAY AFTERNOON AND NIGHT AS THE FRONT IS PROGGED TO EDGE
NORTH INTO THE AREA. WILL GO WITH THAT SCENARIO FOR NOW. A WEAK
COLD FRONT MAY MOVE MOVE THROUGH TOWARD THE END OF THE PERIOD
BRINGING MORE PRECIP CHANCES. UNFORTUNATELY WILL LIKELY NEED TO
KEEP AT LEAST A SMALL MENTION OF PRECIP EVERY PERIOD. HAVE USED A
BLEND OF GUIDANCE TEMPS.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
BEGINNING THURSDAY GFS AND ECMWF A BIT DIFFERENT IN TIMING OF THE
NEXT FRONTAL BOUNDARY TO PUSH THROUGH THE AREA. AT THIS TIME MADE
ONLY SMALL ADJUSTMENT TO POPS. SFC HIGH PRESSURE WILL BUILD INTO THE
AREA FOR THE END OF THE WEEK ALLOWING FOR A BRIEF BREAK BEFORE
ANOTHER BOUNDARY APPROACHES. MADE SLIGHT ADJUSTMENTS TO TEMPS BUT
CONTINUING TO LEAN TOWARD A WELL ABOVE NORMAL PATTERN.
&&
.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
FINDLAY SYSTEM REMAINS OUT AND WILL NOT HAVE ASOS DATA FOR
AMENDMENTS. AMENDMENT NOT SCHEDULED STILL ATTACHED TO TAF.
A WEAK FRONT NORTH OF THE AREA WILL ATTEMPT TO MOVE SOUTH OVER
THE AREA LATER THIS EVENING AND INTO TONIGHT. EXPECTING VFR
CONDITIONS ACROSS SITES THROUGH THE AFTERNOON WITH SOME CONVECTION
POSSIBLE TONIGHT WITH THE FRONT. FOR NOW GIVEN LOW PROBABILITIES
COULD ONLY MENTION SOME VCSH AT A FEW LOCATIONS. OTHERWISE
EXPECTING MVFR VIS DEVELOPING. ALL MODELS APPEAR TO BE SHOWING
THIS AND GIVEN THE SITUATION IT SEEMS REASONABLE.
.OUTLOOK...VFR CONDITIONS WILL PREVAIL EXCEPT FOR A THREAT OF
SHOWERS/THUNDERSTORMS SUNDAY AND AGAIN ON MONDAY.
&&
.MARINE...
WHILE THERE WILL BE SOME FRONTAL BOUNDARIES CROSSING THE LAKE
THROUGH THE FORECAST PERIOD IT DOESN/T LOOK LIKE THERE WILL BE ANY
SIGNIFICANT AIRMASS CHANGE CAUSING INCREASING WINDS AND WAVES ACROSS
THE LAKE. THE MAIN CONCERN WILL ACTUALLY BE BRIEF WIND AND WAVE
ACTIVITY CAUSED BY CONVECTION OVER THE NEXT SEVERAL DAYS.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KUBINA
NEAR TERM...KUBINA
SHORT TERM...KUBINA
LONG TERM...ABE
AVIATION...ABE
MARINE...ABE
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1230 PM CDT SAT JUN 30 2012
.UPDATE...
CURRENT FORECAST LOOKS TO BE ON TRACK THIS MORNING. ONLY
ADJUSTMENTS MADE WERE TO EXPAND POPS IN TIME TO COVER LINGERING
ELEVATED CONVECTION ACROSS CENTRAL AND SOUTH CENTRAL SOUTH DAKOTA.
ALSO...THERE ARE STILL ISOLATED THUNDERSTORMS ACROSS SOUTHERN NORTH
DAKOTA THIS MORNING...AND ONE OR TWO COULD CLIP THE FAR NORTHEAST
CWA. OTHERWISE...TEMPERATURE FORECAST IS HOLDING WELL.
UNCERTAINTY STILL REMAINS WITH THE THUNDERSTORM POTENTIAL THIS
AFTERNOON. THERE IS LIMITED UPPER LEVEL SUPPORT...HOWEVER...THE
ATMOSPHERE WILL DESTABILIZE NICELY THIS AFTERNOON...AND LOOKS LIKE
THE BEST CHANCE FOR THUNDERSTORMS TO DEVELOP WILL BE ALONG THE
SURFACE INVERTED TROUGH DURING PEAK HEATING THIS AFTERNOON...THEN
SPREADING EAST.
SEE UPDATED AVIATION DISCUSSION BELOW.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH MONDAY
MAIN THUNDERSTORM CLUSTER THIS MORNING IS ROLLING EAST ACROSS
NORTH DAKOTA WITH QUIET CONDITIONS OVER SOUTH DAKOTA. YESTERDAY
MORNING THE HRRR HANDLED MORNING CONVECTION VERY WELL. THIS
MORNING...HRRR IS SHOWING ANOTHER CLUSTER OF STORMS DEVELOPING
ACROSS WESTERN SOUTH DAKOTA OVER THE NEXT FEW HOURS...THEN PUSHES
AN AREA OF SCATTERED SHOWERS ACROSS THE STATE THROUGH THE DAY.
ALTHOUGH...UNLIKE YESTERDAY THERE IS REALLY NO NOTEWORTHY UPPER
WAVE TO THE WEST TO IGNITE ANYTHING. THIS SAID...MODELS ARE
INITIALIZING A VORT MAXIMA OVER WYOMING AND THERE IS SOME ACCAS
DEVELOPMENT OVER SOUTHEAST WYOMING. NOTHING CURRENTLY OVER WESTERN
SOUTH DAKOTA AT THIS TIME. HRRR MAY BE OVERDOING THINGS THIS
MORNING BUT WILL MONITOR CLOSELY. CURRENTLY HAVE SLIGHT CHANCE
POPS UP THROUGH 12Z AND DRY CONDITIONS FOR THE MOST PART AFTER
THAT UNTIL LATER THIS AFTERNOON. IF ACCAS/PRECIP DEVELOPS OVER THE
WESTERN PART OF THE STATE BY 12Z...WILL HAVE TO RETHINK CURRENT
PRECIP FORECAST FOR THE AFTERNOON HOURS.
FOR LATER TODAY...FRONTAL BOUNDARY WILL APPROACH THE CENTRAL
DAKOTAS WITH MODERATE TO STRONG INSTABILITY DEVELOPING. 40 TO 50
KNOTS OF SHEAR AVAILABLE WITH THE HIGHEST VALUES OVER NORTHEAST
SOUTH DAKOTA INTO EASTERN NORTH DAKOTA. STRONGEST CAPPING IS
EVIDENT OVER THE NORTHEAST CWA THIS AFTERNOON...WITH WEAKEST
REGION FURTHER WEST NEAR THE FRONTAL BOUNDARY. HI RES MODELS
INDICATING SCT STORM DEVELOPMENT LATE THIS AFTERNOON/EARLY EVENING
ACROSS DIFFERENT PARTS OF THE REGION. CONVECTIVE TRENDS STILL
RATHER DIFFICULT TO NAIL DOWN TODAY THOUGH.
HOT AND HUMID CONDITIONS WILL CONTINUE THROUGH THE SHORT TERM
PERIOD...WITH THE HOTTEST TEMPS EXPECTED ON MONDAY. IMPRESSIVE
THERMAL RIDGE SETS UP RIGHT OVER THE AREA BY MONDAY AFTERNOON.
TEMPS WILL BE WELL INTO THE 90S WITH SOME AREAS AROUND 100
DEGREES. HUMIDITY WILL COME ALONG WITH THIS. COULD BE LOOKING AT
POSSIBLY HEAT ADVISORY HEADLINES IN THE NEXT DAY OR SO.
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY
THE UPPER LEVEL RIDGE WILL HOLD TIGHT OVER THE PLAINS THROUGH MOST
OF THE PERIOD. BY FRIDAY...IT GETS DAMPENED SOME AS A SHORTWAVE
TRACKS ACROSS THE DAKOTAS WITH THE FLOW BECOMING MORE ZONAL. THE
MODELS CONTINUE TO SHOW SPATTERINGS OF PRECIPITATION THROUGHOUT
THE ENTIRE PERIOD AS A SERIES OF FRONTAL BOUNDARIES TRACK ACROSS
THE PLAINS. BIGGEST HINDRANCE TO PRECIPITATION FORMATION WILL BE A
STRONG CAPPING INVERSION THAT WILL BE IN PLACE IN ASSOCIATION WITH
THE UPPER RIDGE. COOLER MID LEVEL TEMPERATURES MOVE IN ON FRIDAY
ALONG WITH THE AFOREMENTIONED UPPER SHORTWAVE. THEREFORE...LOOKS
AS THOUGH THE BEST CHANCE FOR PRECIPITATION WILL COME FRIDAY AND
FRIDAY NIGHT. WILL STICK CLOSE TO THE ALLBLEND SOLUTION...KEEPING
A SLIGHT CHANCE OF PRECIPITATION SOMEWHERE OVER THE CWA MONDAY
NIGHT THROUGH THURSDAY NIGHT...THEN WILL GO WITH CHANCE POPS AT
THE END OF THE PERIOD.
TEMPERATURES WILL BE VERY WARM THROUGH THE ENTIRE PERIOD UNDER THE
INFLUENCE OF THE RIDGE. H85 TEMPERATURES IN THE MID TO UPPER 20S
CELSIUS WILL TRANSLATE TO AFTERNOON HIGH TEMPERATURES IN THE 90S
AND OVERNIGHT LOW TEMPERATURES IN THE UPPER 60S TO MID 70S.
WEDNESDAY AND THURSDAY LOOK TO BE THE WARMEST DAYS...WITH PORTIONS
OF THE CENTRAL AND WESTERN CWA EXPECTED TO SEE MID TO UPPER
90S...WITH A FEW SPOTS LIKELY TO SEE 100+ DEGREE TEMPERATURES.
&&
.AVIATION...
18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
VFR CONDITIONS WILL PREVAIL ACROSS THE AREA TODAY. THERE IS A
POSSIBILITY THAT SHOWERS AND THUNDERSTORMS WILL DEVELOP LATER THIS
AFTERNOON/EVENING...BUT COVERAGE IS EXPECTED TO BE ISOLATED...HAVE ADDED
IN SOME VCTS TO KMBG/KPIR BUT MAY NEED TO ADJUST THE TIMING.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...WISE
SHORT TERM...TMT
LONG TERM...PARKIN
AVIATION...WISE
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1254 PM CDT SAT JUN 30 2012
.AVIATION...
VFR EXPECTED TO CONTINUE THROUGH 01/18Z. ISOLATED THUNDERSTORMS
MAY DEVELOP WELL NORTH AND WEST OF THE TAF SITES THIS AFTERNOON
AND EVENING BUT ARE NOT LIKELY TO AFFECT THE TERMINALS.
&&
PREV DISCUSSION... /ISSUED 314 AM CDT SAT JUN 30 2012/
SHORT TERM...
UA HIGH PRESSURE MAXIMA LOCATED ACROSS ARIZONA/NEW MEXICO AND THE
SERN CONUS...IN ADDITION TO A CONTINUAL WESTWARD RETROGRADING UA LOW
ACROSS SERN TEXAS...WAS THE SYNOPTIC SETUP THIS MORNING...AND WILL
PERSIST THROUGH THE SHORT TERM PERIOD. AS SUCH...A GENERAL WEAKNESS
IN THE HEIGHT FIELDS WILL EXIST FOR THE SOUTHERN PLAINS...WHICH WILL
ALLOW FOR TEMPS TO BE NOTABLY COOLER THAN YESTERDAY...ALBEIT STILL
WARM WITH A TEMP RANGE OF 95-101 ANTICIPATED.
THE SYNOPTIC PATTERN HAS ALLOWED FOR THE MONSOONAL MOISTURE TO SHIFT
SOUTH AND EAST ACROSS THE SOUTHERN PLAINS...OR BASICALLY EAST OF THE
UA RIDGE THAT IS ACROSS ARIZONA/NEW MEXICO. A SFC TROUGH NORTH OF
THE REGION COMBINED WITH THIS MONSOONAL MOISTURE HAS RESULTED IN
SCATTERED SHOWERS AND AN ISOLATED THUNDERSTORM OR TWO THAT DEVELOPED
ACROSS THE SOUTHWESTERN TEXAS PANHANDLE YESTERDAY EVENING...AND PER
0730Z RADAR ANALYSIS IS NOW MOVING SSE ACROSS YOAKUM AND TERRY
COUNTIES /AT LEAST WHAT IS LEFT OF IT/. IT IS OF NOTE TO ALSO
MENTION A LINE OF SHOWERS AND THUNDERSTORMS THAT HAVE DEVELOPED FROM
EASTERN LYNN TO NORTHEASTERN CROSBY COUNTY...COINCIDING WITH BETTER
DEWPOINTS....AND A SOUTHEASTWARD MOVING OUTFLOW BOUNDARY THAT HAS
INDUCED ADDITIONAL LIGHT ECHOES ACROSS FLOYD AND MOTLEY COUNTIES.
WOULD NOT BE OUT OF THE QUESTION FOR SOME LOCATIONS WITHIN THE LINE
OF HEAVIEST SHOWERS AND THUNDERSTORMS TO ACCUMULATE A FEW TENTHS OF
AN INCH OF RAINFALL...FOR THE MERE FACT OF TRAINING OCCURRING. THE
LINE OF STORMS WAS MOVING TO THE SW ACROSS THE PERMIAN BASIN WHICH
IS INDICATIVE OF THE UA RIDGE/S INFLUENCE. THE RUC SOLUTION IS BEST
HANDLING THE ADDITIONAL PRECIP DEVELOPMENT ALBEIT...A BIT MORE
AGGRESSIVE IN REGARD TO COVERAGE. HOWEVER THE RUC DOES SHOW PRECIP
DISSIPATED BY AOA 15Z AND HAVE THEREFORE ADDED SLIGHT CHANCE POPS
ACROSS THE SAID AREAS UNTIL 15Z.
FORECAST SOLUTIONS HINT AT THE MONSOONAL MOISTURE PERSISTING ACROSS
THE WESTERN PANHANDLES AND THE WESTERN SOUTH PLAINS TODAY. A SFC
TROUGH NNW OF THE FA AND A CONTINUED EASTERLY UPSLOPE REGIME WILL
LEAD TO THE LOGICAL CONCLUSION OF A REPEAT SCENARIO OF STORMS
DEVELOPING ACROSS THE WESTERN PANHANDLES...EASTERN NEW MEXICO AND
WESTERN SOUTH THIS AFTERNOON/EVENING. A CAPPING INVERSION IS NOTED
OFF THE CAPROCK...BUT THAT IS NOT THE CASE ON THE CAPROCK...AS
STEEPENED LAPSE RATES WITH LITTLE TO NO CIN IS EXHIBITED BY MODEL
SOUNDINGS. FURTHERMORE...THE SFC-BASED CAPE IS A LITTLE BETTER TODAY
THAN YESTERDAY /AOA 700 J/KG/ WITH PROGGED 0-6 KM BULK SHEAR OF 25
KTS /SIMILAR TO YESTERDAY/. THERE ARE SLIGHT HINTS OF A WEAKNESS OF
MID LEVEL WINDS WHICH IS EVIDENT OF THE UA RIDGE REMAINING AN
INFLUENCE. A MITIGATING FACTOR THAT STANDS OUT IS THAT THE
STEERING FLOW WILL BE FROM THE NORTHEAST...WHICH COULD AID TO
PREVENT STORMS FROM STAYING IN THE CWA FOR LONG PERIODS OF TIME.
HOWEVER...THE AFOREMENTIONED INDICES CAN NOT BE IGNORED WHERE AN
ISOLATED STRONG THUNDERSTORM WITH LCL/S AOA 10KFT SUGGEST THE MAIN
THREAT TO BE GUSTY WINDS. WILL THEREFORE CONTINUE A SLIGHT CHANCE
MENTION ACROSS THE WEST AND NW ZONES THIS AFTERNOON THROUGH TONIGHT.
LONG TERM...
NO SIG CHANGES MADE TO THE LONG TERM PORTION OF THE FCST. UPPER
LEVEL INVERTED TROUGH TO MOVE ACROSS WEST CENTRAL TEXAS SUNDAY
WITH POTENTIAL FOR SOME ISOLATED SHRA OR TSRA MAKING IT INTO THE
SERN ZONES...ALTHOUGH CHANCES STILL LOOK TOO SMALL TO MENTION IN
THE FCST ATTM. AS THE TROUGH CONTINUES TO MOVE WWD THE CENTER OF
THE UPPER RIDGE WILL RETROGRADE TAKING DEEPER MOISTURE WITH IT
MINIMIZING RAIN CHANCES ACROSS THE WRN ZONES SUNDAY. ON THE
POSITIVE SIDE...FURTHER DECREASES IN HEIGHTS AND THICKNESSES WILL
TRANSLATE INTO COOLER TEMPERATURES AGAIN SUNDAY...MAINLY LOWER TO
MIDDLE 90S.
EARLY IN THE WEEK THE WRN PORTION OF THE UPPER RIDGE THAT WILL BE
DOMINATING MUCH OF THE CONUS WILL BEGIN TO EXPAND NEWD TOWARD THE
CENTRAL PLAINS. FCST AREA WILL REMAIN ON THE SOUTH OR SOUTHEAST
FLANK OF THE CENTER WITH RELATIVELY WEAKER HEIGHTS AND EASTERLY
FLOW IN PLACE ACROSS THE REGION. MAY SEE THE DEEPER MONSOONAL EDGE
BACK TO THE EAST BY THE END OF THE WEEK...ALTHOUGH TOO EARLY TO
MENTION ANY RAIN POTENTIAL. PATTERN SHOULD HELP THE AREA AVOID THE
EXTREME HEAT OF EARLIER THIS WEEK...ALTHOUGH WILL CONTINUE TO RUN
ABOVE SEASONAL NORMALS THROUGH THE FCST PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 65 91 63 90 65 / 20 10 10 0 0
TULIA 67 90 66 89 66 / 20 0 0 0 0
PLAINVIEW 68 91 67 90 67 / 10 0 0 0 0
LEVELLAND 68 91 66 92 67 / 10 0 0 0 0
LUBBOCK 69 92 68 92 69 / 10 0 0 0 0
DENVER CITY 68 91 66 90 67 / 10 10 10 0 0
BROWNFIELD 69 91 67 91 67 / 10 10 10 0 0
CHILDRESS 71 96 70 95 72 / 0 0 0 10 0
SPUR 70 93 71 92 71 / 0 10 10 10 0
ASPERMONT 71 95 70 96 72 / 0 10 10 10 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
01
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1214 PM CDT SAT JUN 30 2012
.SHORT TERM...TODAY THROUGH MONDAY NIGHT
327 AM CDT SAT JUN 30 2012
MAIN FORECAST CONCERNS REMAIN TO BE PRECIPITATION CHANCES
THROUGHOUT AS WELL AS HEAT INDICES ON MONDAY.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED SUBTROPICAL RIDGING STILL DOMINATING MUCH OF THE SOUTHERN
U.S....WITH RIDGING COMING OFF OF THIS EXTENDING FROM THE FOUR
CORNERS REGION INTO ALBERTA AND SASKATCHEWAN. THE FORECAST AREA LIES
IN NORTHWEST FLOW DOWNSTREAM OF THIS RIDGE EXTENSION. WITHIN THE
NORTHWEST FLOW...SHORTWAVES ARE EVIDENT OVER OVER THE FORECAST AREA
AS WELL AS BACK OVER THE DAKOTAS. THE SHORTWAVE OVER THE FORECAST
AREA HAD SOME SHOWERS AND EMBEDDED THUNDERSTORMS WITH IT LAST
EVENING WHEN IT WAS OVER SOUTHWEST MINNESOTA...BUT NOW MOST OF WHAT
IS LEFT IS SOME MID CLOUDS. WITH THE SHORTWAVES BACK OVER THE
DAKOTAS...SOME SHOWERS AN STORMS ARE NOTED OVER CENTRAL NORTH
DAKOTA. OTHER CONVECTION OF INTEREST IS OVER SOUTHERN IOWA...
SITUATED JUST TO THE NORTH OF A STATIONARY FRONTAL BOUNDARY OVER
NORTHERN MISSOURI. THIS CONVECTION IS BEING AIDED BY INCREASE
925-850MB MOISTURE TRANSPORT COMING UP THROUGH EASTERN KANSAS AND
WESTERN MISSOURI. REGARDING MOISTURE...IT IS INTERESTING TO NOTE
THAT PER 00Z SOUNDINGS...THE AMOUNT OF MOISTURE ALONG THE BOUNDARY
IN THE ATMOSPHERE LOOKS TO HAVE DIMINISHED. AT DVN AND OAX...THE
PRECIPITABLE WATER HAS DROPPED TO AROUND 1.6 INCHES OR 150 PERCENT
OF NORMAL...COMPARED TO THE AROUND 2 INCHES OR 200 PERCENT OF NORMAL
SEEN ON THE 29TH AT 00Z. THIS MIGHT BE A RESULT OF THE VARIOUS
ROUNDS OF CONVECTION THAT HAVE ROLLED THROUGH OVER THE PAST 24
HOURS. PRECIPITABLE WATER HAS COME UP TO NEAR 1 INCH AT MPX AND
ABR...BUT THE SOUNDINGS REMAIN FAIRLY DRY...THUS THE CLEAR SKIES AT
BOTH LOCATIONS.
TODAY AND TONIGHT...FORECAST AREA LOOKS TO REMAIN IN THE NORTHWEST
FLOW ALOFT...THOUGH THE FLOW DOES BACK SLIGHTLY IN RESPONSE TO
RIDGING OVER THE NORTHERN ROCKIES PUSHING EAST. THE UPPER LEVEL FLOW
WILL ALLOW THE SHORTWAVES OVER THE DAKOTAS TO PASS ACROSS THE AREA
BETWEEN 18-03Z. NOT THAT THRILLED ABOUT THE PRECIPITATION CHANCES
WITH THESE SHORTWAVES...PRIMARILY BECAUSE THE MAIN INSTABILITY AND
MOISTURE REMAIN STUCK TO THE SOUTH ACROSS SOUTHERN IOWA CLOSER TO
THE STATIONARY FRONTAL BOUNDARY. IN ADDITION...PRETTY MUCH ALL
GUIDANCE HAS TODAY AND TONIGHT DRY...INCLUDING SURPRISINGLY THE GFS
WHICH HAS BEEN TOO ACTIVE WITH PRECIPITATION. 00Z HIRES ARW RUN HAS
A GOOD HANDLE ON THE CONVECTION OVER NORTH DAKOTA AND HAS IT DIE
BEFORE IT REACHES HERE...WHICH SEEMS REASONABLE SINCE IT IS GOING
INTO A STABLE ENVIRONMENT. THEREFORE...HAVE PULLED PRECIPITATION
CHANCES FOR TODAY AND TONIGHT. SOUNDINGS TOO LOOK FAIRLY DRY AND
CAPPED AROUND 800MB. WE SHOULD SEE A LOT MORE SUNSHINE TODAY WITH
NOT AS MUCH CONVECTIVE BLOW-OFF. SOME MID CLOUDS MAY COME IN LATE
WITH THE APPROACH OF THE SHORTWAVES...BUT NOT ENOUGH TO HAMPER
HEATING. 850MB TEMPS OF 16C NORTH TO 20C SOUTH SUPPORT HIGHS IN THE
MID 80S TO LOWER 90S. MOST OF TONIGHT LOOKS MOSTLY CLEAR...THOUGH
SOME MID CLOUDS MAY COME INTO WESTERN PORTIONS OF THE FORECAST AREA
AFTER MIDNIGHT. LOWS SHOULD GENERALLY BE IN THE 60S...THOUGH THE
TYPICAL COOL SPOTS OF WISCONSIN MAY BE ABLE TO DIP INTO THE UPPER
50S.
SUNDAY AND SUNDAY NIGHT...THE UPPER RIDGING OVER THE NORTHERN
ROCKIES LOOKS TO GET A BETTER PUSH EASTWARD DURING THIS PERIOD...DUE
TO TROUGHING CURRENTLY OFF THE WEST COAST LIFTING INTO THE NORTHERN
ROCKIES. THE RESPONSE TO THE EASTWARD MOVEMENT TO THE UPPER RIDGE IS
TO INCREASE LOW LEVEL SOUTHERLY FLOW OVER THE PLAINS...WHICH MEANS
THAT STATIONARY FRONT IS GOING TO LIFT NORTH AS A WARM FRONT. AT
LEAST FOR SUNDAY...THE FRONT SHOULD STAY SOUTH OF THE AREA...KEEPING
THE BULK OF THE PRECIPITATION ON IT TO THE SOUTH. DID KEEP SOME 20
PERCENT CHANCES IN SOUTH OF I-90 FOR SUNDAY AS A BUFFER. LOOKS LIKE
WE WILL STILL HAVE TO CONTEND WITH MID CLOUDS...ESPECIALLY IN THE
MORNING WHEN THE BEST ISENTROPIC LIFT IS OCCURRING ON THE 315K
SURFACE. BETTER SURGE NORTHWARD OF THE WARM FRONT LOOKS TO OCCUR
SUNDAY NIGHT. HOW FAST VARIES FROM MODEL TO MODEL...WITH THE 30.00Z
NAM HAVING IT REACH I-94 COMPARED TO ONLY NORTHEAST IOWA AT MOST FOR
THE 30.00Z GFS/ECMWF. THIS IS CRITICAL TO SOME DEGREE SINCE
INCREASING MOISTURE TRANSPORT ABOVE THE FRONT COULD RESULT IN
ELEVATED CONVECTION. CONFIDENCE IN CONVECTION IS LOW SINCE IT IS
HARD AT THIS POINT TO FIND ANY FOCUSED AREAS OF MOISTURE TRANSPORT.
HOWEVER... SYNOPTICALLY THE SCENARIO CAN FAVOR CONVECTION. FOR NOW
STAYED WITH THE PREVIOUS FORECAST OF 20 PERCENT CHANCES. WITH WARMER
AIR MOVING IN...NOTED BY 850MB TEMPS CLIMBING TO AROUND 20C BY 18Z
SUNDAY...ANTICIPATE HIGHS A FEW DEGREES WARMER THAN TODAY. SIMILAR
SITUATION WITH LOWS...GIVEN WARMER AND MORE HUMID AIR WILL RESULT IN
WARMER TEMPERATURES AT NIGHT.
MONDAY AND MONDAY NIGHT...UPPER RIDGING LOOKS TO CONTINUE TO BUILD
NORTHEASTWARD TOWARDS THE FORECAST AREA...KEEPING A SOUTHWEST LOW
LEVEL WARM ADVECTION PATTERN IN PLACE. DIFFERENCES STILL REMAIN ON
THE NORTHWARD SPEED OF THE WARM FRONT. HOWEVER...BY 00Z TUESDAY MOST
OF THE MODELS COME INTO AGREEMENT OF A POSITION AT LEAST NEAR I-94.
INSTABILITY ALONG THE FRONT COMBINED WITH THE WEAK FRONTAL
CONVERGENCE COULD PROVE ENOUGH TO TRIGGER CONVECTION. THERE ARE
INDICATIONS OF A WEAK SHORTWAVE MOVING THROUGH TOO. IF THIS DOES NOT
COME THROUGH...700MB TEMPS ARE PROGGED TO INCREASE THROUGH THE
DAY...TOWARDS 11C OR SO BY THE END OF THE DAY...WHICH COULD
EFFECTIVELY CAP CONVECTION ON THE FRONT. GIVEN THIS UNCERTAINTY AND
POTENTIAL FOR CAPPING...STILL ONLY KEPT PRECIPITATION CHANCES IN THE
30-40 RANGE FOR MONDAY. CHANCES SHIFT NORTHEAST AND LOWER TO 20-30
WITH THE WARM FRONT LIFTING PERHAPS ALL THE WAY THROUGH THE FORECAST
AREA. 850MB TEMPS WARM TO 20-23C ON MONDAY WHICH WOULD SUPPORT HIGHS
IN THE UPPER 80S TO MID 90S. IF THE 30.00Z NAM/UKMET ARE RIGHT WITH
THE WARM AIR COMING IN...SUGGESTING 24-26C 850MB TEMPS POSSIBLE...
HIGHS COULD BE WARMER YET. ONE CONCERN WITH THE FRONT IN THE AREA IS
THE HIGHER DEWPOINTS AROUND 70 ACCOMPANYING IT. THESE DEWPOINTS
COMBINED WITH THE FORECAST HIGH TEMPERATURES MAY RESULT IN HEAT
INDICES AROUND 100 IN VALLEY AREAS AND IN NORTHEAST IOWA. THUS...A
HEAT ADVISORY MAY BE NEEDED. WARM NIGHT LIKELY MONDAY NIGHT BEING
MOSTLY SOUTH OF THE FRONT. 70S ARE LIKELY FOR LOWS.
IF CONVECTION OCCURS SUNDAY THROUGH MONDAY NIGHT...0-6 KM SHEAR
IS MOSTLY BELOW 30 KTS. THEREFORE...NOT OVERLY CONCERNED ABOUT
SEVERE WEATHER AT THIS POINT. STORMS COULD PRODUCE LOCALLY HEAVY
RAIN GIVEN DEEP WARM CLOUD DEPTHS...BUT AGAIN CONFIDENCE OVERALL
IS LOW ON CONVECTION IN THE FIRST PLACE.
.LONG TERM...TUESDAY THROUGH FRIDAY NIGHT
327 AM CDT SAT JUN 30 2012
BUILDING HEAT AND SMALL CHANCES FOR PRECIPITATION REMAIN MAIN
CONCERN FOR THE LONG TERM PERIOD.
30.00Z ECMWF/CANADIAN/GFS/GFS ENSEMBLES ALL SHOW THE CURRENT
SUBTROPICAL RIDGING OVER THE SOUTHERN U.S. EXPANDING ACROSS MUCH OF
THE U.S. DURING THIS PERIOD. HOWEVER...THERE ARE DEFINITELY SOME
ISSUES TO DEAL WITH. THE FIRST IS LATE TUESDAY INTO TUESDAY NIGHT
WHERE THE 30.00Z GFS...GFS ENSEMBLES AND CANADIAN SHOW A COLD FRONT
DROPPING SOUTHEAST THROUGH THE AREA...ASSOCIATED WITH A SHORTWAVE
CROSSING THE WESTERN GREAT LAKES. THE ECMWF HAS YET TO SHOW THIS
COLD FRONT COMING THROUGH. GIVEN THE MODEL SPLIT...FOR NOW KEPT THE
LOW PRECIPITATION CHANCES GOING. THE FRONT SHOULD NOT DROP TOO FAR
SOUTH OF THE AREA GIVEN THE BUILDING RIDGING. IN FACT...BY MID-DAY
THURSDAY...THE GFS...MAJORITY OF GFS ENSEMBLES AND ECMWF ALL SUGGEST
THE WARM FRONT WILL BE NORTH OF THE AREA. THIS WILL USHER IN THE
HEAT SEEN TO OUR SOUTH. LOOKS LIKE THE AIRMASS SHOULD BE CAPPED
ENOUGH SUCH THAT EVEN WITH THE WARM FRONTAL PASSAGE...HAVE WENT WITH
A DRY FORECAST WEDNESDAY THROUGH THURSDAY NIGHT. THIS IS EVEN WELL
AGREED UPON BY THE GFS WHICH AGAIN IS USUALLY TOO ACTIVE WITH QPF. A
COLD FRONT MAY START TO APPROACH THE AREA FRIDAY INTO FRIDAY NIGHT
FROM THE NORTHWEST...THOUGH WITH IT COMING INTO THE UPPER
RIDGE...WOULD NOT BE SURPRISED IF IT IS SLOWER LIKE THE 30.00Z
ECMWF. STILL...THE FRONT COMING IN WARRANTS SOME LOW CHANCES OF
SHOWERS AND THUNDERSTORMS IN NORTHERN SECTIONS OF THE FORECAST AREA.
REGARDING THE HEAT...850MB TEMPS NO MATTER WHAT SCENARIO PLAYS OUT
LOOK TO STAY AT OR ABOVE 20C. IN FACT...22-24C ARE MORE
LIKELY...WITH THE 24C AIR COMING IN FOR THURSDAY AND FRIDAY. THESE
TWO DAYS NEXT WEEK APPEAR TO BE THE HOTTEST...WITH DEFINITE
POTENTIAL TO APPROACH 100. FOR NOW RAISED HIGHS A COUPLE DEGREES
ABOVE THE CONSENSUS FOR THURSDAY AND FRIDAY. IN SUMMARY...BASICALLY
EVERYDAY IN THE LONG TERM SEES HIGHS IN THE 90S ACROSS THE FORECAST
AREA. WITH DEWPOINTS SUGGESTED TO RANGE FROM THE MID 60S TO LOWER
70S...POTENTIAL EXISTS EACH DAY FOR PORTIONS OF THE FORECAST
AREA TO HAVE HEAT INDICES APPROACH OR EXCEED 100...THE HEAT ADVISORY
THRESHOLD. WILL BE MENTIONING THE LONG PERIOD OF POSSIBLE HEAT IN
THE HWO. NOTE...ALSO RAISED LOW TEMPERATURES A LITTLE ABOVE THE
CONSENSUS. WOULD NOT BE SURPRISED TO HAVE A FEW 80 DEGREE LOWS.
&&
.AVIATION...THROUGH 18Z SUNDAY
1214 PM CDT SAT JUN 30 2012
KRST/KLSE TAF SITES WILL BE IN BETWEEN A WEAK TROUGH OF LOW
PRESSURE PASSING TO THE NORTH AND SCATTERED CONVECTION FIRING
ALONG A QUASI-STATIONARY FRONTAL BOUNDARY STRETCHING ACROSS SOUTHERN IA
INTO IL. SCATTERED VFR ALTOCUMULUS WITH BASES AOA 12KFT IS EXPECTED
AT BOTH KRST/KLSE THROUGH THE PERIOD AS A RESULT. ONLY CONCERN WILL BE
THE POSSIBILITY OF SOME LIGHT 3-5SM BR IN THE 09-14Z TIME FRAME
WITH LIGHT AIR FLOW AND SLOWLY INCREASING LOWER LEVEL HUMIDITY.
HAVE ADDED 4SM BR IN THE 09-14Z TIME FRAME AT BOTH TAF SITES.
&&
.CLIMATE...
455 AM CDT SAT JUN 30 2012
A FEW OTHER INTERESTING NOTES REGARDING THE HEAT BEGINNING MONDAY.
850MB STANDARDIZED ANOMALIES ARE FORECAST AT LEAST 2-2.5 ABOVE
NORMAL FROM MONDAY THROUGH FRIDAY...WITH THURSDAY AND FRIDAY
PERHAPS NEAR 3. ALSO...WILL HAVE TO WATCH DEWPOINTS CLOSELY AND
HOW MUCH CONVECTION OCCURS. IF WE DO NOT GET MUCH CONVECTION OVER
THE NEXT FEW DAYS...THE HEAT MAY CAUSE DEWPOINTS TO MIX OUT MORE
DUE TO THE ABNORMALLY DRY TO MODERATE DROUGHT SITUATION IN PLACE.
ALSO...THE DROUGHT COULD RAPIDLY INTENSIFY IF THERE IS A LACK OF
CONVECTION...WHICH THEN WOULD RESULT IN HIGHER TEMPERATURES. ON
THE OTHER HAND...IF MORE CONVECTION OCCURS...THEN TEMPERATURES MAY
BE HELD DOWN SOME BUT HEAT INDICES COULD BE HIGHER.
LA CROSSE RECORD HIGHS NEXT WEEK ARE ALL IN THE 100-105 RANGE.
MOST OF THESE SHOULD BE SAFE. HOWEVER...IT IS LIKELY WE WILL BE NEAR
THESE...ESPECIALLY IF LITTLE IN THE WAY OF CONVECTION OCCURS THE
NEXT FEW DAYS. ROCHESTER IS IN A SIMILAR SITUATION WITH THE RECORD
HIGHS MAINLY BETWEEN 100-105. ONE EXCEPTION TO THIS IS ON THE 4TH
WITH A RECORD HIGH OF 98. THAT STILL SEEMS SAFE AT THIS TIME.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
327 AM CDT SAT JUN 30 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...DAS
CLIMATE...AJ