Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 08/07/15
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1247 PM MDT WED AUG 5 2015
.UPDATE...
ISSUED AT 1238 PM MDT WED AUG 5 2015
CURRENTLY...
CUMULUS CLOUDS HAVE STARTED TO DEVELOP OVER THE HIGHER TERRAIN
WITH THE GREATEST COVERAGE OVER THE CENTRAL MTNS AT THIS TIME.
PRIMARY FORECAST UNCERTAINTY AT THIS TIME IS THE POTENTIAL FOR
ISOLATED TS INITIATION OVER THE FAR EASTERN PLAINS NEAR THE
CO/KS. OUTFLOW GENERATED BY AN MCS LAST NIGHT HAS PUSHED MUCH
HIGHER DEW POINTS INTO THE EASTERN PLAINS...WITH CURRENT READINGS
NEAR THE MID 60S. AS A RESULT CAPE VALUES NEAR THE BOARDER ARE
REACHING 3000 J/KG PER SPC MESOSCALE ANALYSIS AND LASTEST LAPS
DATA. WITH THAT BEING SAID...THERE IS NOT MUCH OF A TRIGGER TO
WORK WITH THIS AFTERNOON...SO HAVE KEPT SILENT POPS NEAR THE
BOARDER...BUT WILL HAVE TO MONITOR CLOSELY AS STORMS COULD BECOME
STRONG IF CAPE IS REALIZED. LUKINBEAL
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 428 AM MDT WED AUG 5 2015
...HOTTER TODAY WITH ONLY SPARSE AFTERNOON THUNDERSTORM ACTIVITY
POSSIBLE...
CONVECTION YESTERDAY WAS VIRTUALLY NIL ACROSS SOUTHERN
COLORADO...AND TODAY LOOKS QUITE SIMILAR...ALTHOUGH THERE ARE STILL
SOME FORECAST CHALLENGES TO DEAL WITH. FIRST IS THE PUSH OF LOW
LEVEL MOISTURE INTO THE SOUTHEAST PLAINS WHICH OCCURRED BEHIND AN
OUTFLOW BOUNDARY WHICH MOVED THROUGH LAST EVENING. 00Z RUNS DID NOT
ALL HAVE A GOOD HANDLE ON THIS DETAIL. OF THEM...NAM12 SEEMED TO DO
THE BEST...AND HRRR APPEARS TO HAVE CAUGHT ON AS WELL. NAM...HRRR
AND RAP13 ALL MIX OUT THIS SHALLOW LEVEL LEVEL MOISTURE ALONG THE I-
25 CORRIDOR AND ADJACENT EASTERN PLAINS DURING THE AFTERNOON...BUT
DIFFER WITH THE PERSISTENCE OF 50+ DEW POINTS FARTHER TO THE EAST
NEAR THE KS BORDER.
MEANWHILE...UPPER RIDGE ALOFT WILL HOLD FIRM AS TROF ACROSS CA RIDES
OVER THE TOP OF IT ACROSS THE NORTHERN GREAT BASIN AND WY LATE THIS
AFTERNOON THROUGH TONIGHT. THIS FEATURE WILL BRING A SLIGHT
INCREASE IN MOISTURE OVER CO AHEAD OF IT...THOUGH IT SHOULD BE
PRETTY MID AND HIGH BASED. SFC DEW POINTS ACROSS THE MOUNTAINS
SHOULD DROP BACK INTO THE 30S AND LOWER 40S AGAIN...WHICH SHOULD
KEEP ANY CONVECTION SPARSE AND HIGH BASED...THUS MORE LIKELY TO
PRODUCE ONLY SPOTTY LIGHT RAINFALL AT BEST...AND ERRATIC GUSTY WINDS
IF IT CAN GET GOING AT ALL. WILL CUT BACK POPS A BIT...BUT STILL
MAINTAIN PATCHY ISOLATED POPS ACROSS THE MOUNTAINS THIS AFTERNOON.
OTHER CHALLENGE AREA WILL BE ALONG A DRY LINE ACROSS SE CO. SOME OF
THE MODELS HINT AT DEVELOPING AN ISOLATED STORM OR TWO ACROSS THE
FAR EASTERN PLAINS LATE THIS AFTERNOON AND EVENING...MAINLY ACROSS
THE EASTERN MOST COUNTIES AND POTENTIALLY THE RATON RIDGE REGION.
CHANCES DO NOT LOOK ALL THAT GREAT...AS MAJORITY OF THE MODELS MIX
OUT THE LOW LEVEL MOISTURE INTO THE 40S AND LOWER 50S. EXCEPTION TO
THIS IS THE NAM WHICH HOLDS ON TO SOME LOWER 60 DEW POINTS ACROSS
BACA COUNTY. HRRR SEEMS TO BE TRENDING TOWARDS THE NAM12. HAVE
INTRODUCED SOME SILENT POPS OUT ACROSS THE FAR EAST PLAINS FOR NOW.
IF MODEL TRENDS CONTINUE...A LATER UPDATE MAY BE NEEDED TO BUMP POPS
UP A TAD. IF CAPES CAN STAY HIGH ENOUGH...AND SUFFICIENT
CONVERGENCE ALONG THE DRYLINE CAN INITIATE A THUNDERSTORM...THERE IS
A LOW POTENTIAL FOR A STRONG STORM IN THIS AREA...AS DEEP LAYER
SHEARS WILL BE RUNNING AROUND 35 KTS. BUT WE SEEM TO BE LACKING
MUCH OF A TRIGGER IN THE WAY OF A DISTURBANCE...AND MODELS TEND TO
OVERDO CONVECTIVE COVERAGE IN CASES LIKE THESE...SO WILL STICK WITH
SILENT POPS FOR NOW. THIS AGREES WELL WITH SPC DAY1 OUTLOOK FOR
NOW...WHICH DOESN`T HAVE THUNDER OUTLOOKED FOR THE FAR SOUTHEAST
PLAINS AT THIS POINT EITHER.
TONIGHT...ANY THUNDERSTORMS SHOULD DIMINISH QUICKLY WITH LOSS OF
HEATING. TEMPERATURES TONIGHT MAY BE MORE MILD FOR THE I-25
CORRIDOR DUE TO INCREASING WESTERLY DOWNSLOPE FLOW TOWARDS MORNING.
ELSEWHERE...CLEARING SKIES SHOULD ALLOW FOR ANOTHER NIGHT OF GOOD
RADIATIONAL COOLING FOR THE HIGH VALLEYS. -KT
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 428 AM MDT WED AUG 5 2015
...MONSOON MOISTURE RETURNS FOR THE WEEKEND AND BEYOND...
THURSDAY...WILL CONTINUE TO BE MAINLY DRY...WITH ABOVE NORMAL
TEMPERATURES...WITH THE UPPER RIDGE CENTERED OVER NEW MEXICO
PROVIDES FAIRLY DRY WESTERLY FLOW. MODELS PUTTING OUT ALMOST NO
RAINFALL...SO THE FORECAST WITH SILENT POPS TO LOW GRADE ISOLATED
OVER THE HIGHER TERRAIN LOOKS GOOD. MID LEVEL TEMPERATURES
FORECAST TO BE BELOW 20C...SO HIGHS WILL LIKELY BE AROUND 100
DEGREES F IN THE LOWER ARKANSAS VALLEY AND 90S ELSEWHERE ON THE
PLAINS. HIGHS IN THE 70S AND 80S ACROSS THE HIGH VALLEYS AND 50S
AND 60S ACROSS THE MOUNTAINS WILL BE REALIZED.
FRIDAY...TRANSITION BEGINS AS A SHORTWAVE OVER THE WESTERN US
NUDGES THE UPPER RIDGE EAST AND BRINGS THE MONSOON MOISTURE INTO
THE AREA LATER IN THE DAY AND OVERNIGHT. THE SHORTWAVE WILL LIKELY
BE FAR ENOUGH NORTH TO KEEP MAIN FOCUS OF SHOWERS AND STORMS
FARTHER NORTH. HOWEVER THERE WILL BE A CHANCE FOR LOCALLY HEAVY
RAIN...AND A FLASH FLOOD THREAT...ESPECIALLY OVER THE HIGHER
TERRAIN. HIGH TEMPERATURES WILL BE A LITTLE LOWER...DUE TO
INCREASED CLOUD COVER AND LOWERING MID LEVEL TEMPERATURE.
SATURDAY...WITH THE MONSOON MOISTURE OVER THE AREA...ANOTHER DAY
WITH THE CHANCE FOR SHOWERS AND STORMS AND LOCALLY HEAVY
RAIN...AND THE THREAT FOR SOME FLASH FLOODING...AGAIN ESPECIALLY
OVER THE HIGHER TERRAIN. HIGH TEMPERATURES WILL TICK DOWN A LITTLE
MORE.
SUNDAY...GFS AND EUROPEAN MODELS SUGGEST THAT A FRONT WILL MOVE
ACROSS THE PLAINS EARLY...AND UPSLOPE FLOW WILL OCCUR AND
STRENGTHEN DURING THE DAY. SO SHOWERS AND STORMS WILL INITIATE
ACROSS THE HIGHER TERRAIN AND MOVE OUT INTO THE PLAINS DURING THE
EVENING AND OVERNIGHT.
THROUGH WEDNESDAY...MODELS SUGGEST THAT THE UPPER RIDGE WILL
REDEVELOP OVER THE ROCKIES. WITH SOME MONSOON MOISTURE IN
PLAY...AND UPSLOPE FLOW MONDAY AND TUESDAY ACROSS THE
PLAINS...THERE WILL BE DAILY CHANCES FOR SHOWERS AND
STORMS...DEVELOPING ACROSS THE HIGHER TERRAIN...WITH SOME SPREAD
INTO LOWER ELEVATIONS. -TLM-
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1121 AM MDT WED AUG 5 2015
VFR CONDITIONS ARE EXPECTED AT THE TAF SITES THROUGH THE END OF
THE PERIOD. SHOWERS AND THUNDERSTORMS WILL FORM OVER THE HIGHER
TERRAIN THIS AFTERNOON...BUT OVERALL COVERAGE AND ACTIVITY WILL BE
SPARSE...THEREFORE STORMS ARE UNLIKELY TO AFFECT THE TERMINALS.
WINDS WILL INCREASE OUT OF THE SOUTH TO SOUTHEAST AT AROUND 10-15
KTS FOR KCOS AND KPUB BEFORE SHIFTING TO A DIURNALLY DRIVEN
DRAINAGE FLOW OUT OF THE NORTHWEST TO WEST OVERNIGHT. KALS WILL
SEE WINDS OUT OF THE SW DURING THE AFTERNOON WITH SPEEDS GENERALLY
UNDER 15 KNOTS. LUKINBEAL
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AL/PE
SHORT TERM...KT
LONG TERM...TM
AVIATION...AL/PE
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1124 AM MDT WED AUG 5 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 428 AM MDT WED AUG 5 2015
...HOTTER TODAY WITH ONLY SPARSE AFTERNOON THUNDERSTORM ACTIVITY
POSSIBLE...
CONVECTION YESTERDAY WAS VIRTUALLY NIL ACROSS SOUTHERN
COLORADO...AND TODAY LOOKS QUITE SIMILAR...ALTHOUGH THERE ARE STILL
SOME FORECAST CHALLENGES TO DEAL WITH. FIRST IS THE PUSH OF LOW
LEVEL MOISTURE INTO THE SOUTHEAST PLAINS WHICH OCCURRED BEHIND AN
OUTFLOW BOUNDARY WHICH MOVED THROUGH LAST EVENING. 00Z RUNS DID NOT
ALL HAVE A GOOD HANDLE ON THIS DETAIL. OF THEM...NAM12 SEEMED TO DO
THE BEST...AND HRRR APPEARS TO HAVE CAUGHT ON AS WELL. NAM...HRRR
AND RAP13 ALL MIX OUT THIS SHALLOW LEVEL LEVEL MOISTURE ALONG THE I-
25 CORRIDOR AND ADJACENT EASTERN PLAINS DURING THE AFTERNOON...BUT
DIFFER WITH THE PERSISTENCE OF 50+ DEW POINTS FARTHER TO THE EAST
NEAR THE KS BORDER.
MEANWHILE...UPPER RIDGE ALOFT WILL HOLD FIRM AS TROF ACROSS CA RIDES
OVER THE TOP OF IT ACROSS THE NORTHERN GREAT BASIN AND WY LATE THIS
AFTERNOON THROUGH TONIGHT. THIS FEATURE WILL BRING A SLIGHT
INCREASE IN MOISTURE OVER CO AHEAD OF IT...THOUGH IT SHOULD BE
PRETTY MID AND HIGH BASED. SFC DEW POINTS ACROSS THE MOUNTAINS
SHOULD DROP BACK INTO THE 30S AND LOWER 40S AGAIN...WHICH SHOULD
KEEP ANY CONVECTION SPARSE AND HIGH BASED...THUS MORE LIKELY TO
PRODUCE ONLY SPOTTY LIGHT RAINFALL AT BEST...AND ERRATIC GUSTY WINDS
IF IT CAN GET GOING AT ALL. WILL CUT BACK POPS A BIT...BUT STILL
MAINTAIN PATCHY ISOLATED POPS ACROSS THE MOUNTAINS THIS AFTERNOON.
OTHER CHALLENGE AREA WILL BE ALONG A DRY LINE ACROSS SE CO. SOME OF
THE MODELS HINT AT DEVELOPING AN ISOLATED STORM OR TWO ACROSS THE
FAR EASTERN PLAINS LATE THIS AFTERNOON AND EVENING...MAINLY ACROSS
THE EASTERN MOST COUNTIES AND POTENTIALLY THE RATON RIDGE REGION.
CHANCES DO NOT LOOK ALL THAT GREAT...AS MAJORITY OF THE MODELS MIX
OUT THE LOW LEVEL MOISTURE INTO THE 40S AND LOWER 50S. EXCEPTION TO
THIS IS THE NAM WHICH HOLDS ON TO SOME LOWER 60 DEW POINTS ACROSS
BACA COUNTY. HRRR SEEMS TO BE TRENDING TOWARDS THE NAM12. HAVE
INTRODUCED SOME SILENT POPS OUT ACROSS THE FAR EAST PLAINS FOR NOW.
IF MODEL TRENDS CONTINUE...A LATER UPDATE MAY BE NEEDED TO BUMP POPS
UP A TAD. IF CAPES CAN STAY HIGH ENOUGH...AND SUFFICIENT
CONVERGENCE ALONG THE DRYLINE CAN INITIATE A THUNDERSTORM...THERE IS
A LOW POTENTIAL FOR A STRONG STORM IN THIS AREA...AS DEEP LAYER
SHEARS WILL BE RUNNING AROUND 35 KTS. BUT WE SEEM TO BE LACKING
MUCH OF A TRIGGER IN THE WAY OF A DISTURBANCE...AND MODELS TEND TO
OVERDO CONVECTIVE COVERAGE IN CASES LIKE THESE...SO WILL STICK WITH
SILENT POPS FOR NOW. THIS AGREES WELL WITH SPC DAY1 OUTLOOK FOR
NOW...WHICH DOESN`T HAVE THUNDER OUTLOOKED FOR THE FAR SOUTHEAST
PLAINS AT THIS POINT EITHER.
TONIGHT...ANY THUNDERSTORMS SHOULD DIMINISH QUICKLY WITH LOSS OF
HEATING. TEMPERATURES TONIGHT MAY BE MORE MILD FOR THE I-25
CORRIDOR DUE TO INCREASING WESTERLY DOWNSLOPE FLOW TOWARDS MORNING.
ELSEWHERE...CLEARING SKIES SHOULD ALLOW FOR ANOTHER NIGHT OF GOOD
RADIATIONAL COOLING FOR THE HIGH VALLEYS. -KT
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 428 AM MDT WED AUG 5 2015
...MONSOON MOISTURE RETURNS FOR THE WEEKEND AND BEYOND...
THURSDAY...WILL CONTINUE TO BE MAINLY DRY...WITH ABOVE NORMAL
TEMPERATURES...WITH THE UPPER RIDGE CENTERED OVER NEW MEXICO
PROVIDES FAIRLY DRY WESTERLY FLOW. MODELS PUTTING OUT ALMOST NO
RAINFALL...SO THE FORECAST WITH SILENT POPS TO LOW GRADE ISOLATED
OVER THE HIGHER TERRAIN LOOKS GOOD. MID LEVEL TEMPERATURES
FORECAST TO BE BELOW 20C...SO HIGHS WILL LIKELY BE AROUND 100
DEGREES F IN THE LOWER ARKANSAS VALLEY AND 90S ELSEWHERE ON THE
PLAINS. HIGHS IN THE 70S AND 80S ACROSS THE HIGH VALLEYS AND 50S
AND 60S ACROSS THE MOUNTAINS WILL BE REALIZED.
FRIDAY...TRANSITION BEGINS AS A SHORTWAVE OVER THE WESTERN US
NUDGES THE UPPER RIDGE EAST AND BRINGS THE MONSOON MOISTURE INTO
THE AREA LATER IN THE DAY AND OVERNIGHT. THE SHORTWAVE WILL LIKELY
BE FAR ENOUGH NORTH TO KEEP MAIN FOCUS OF SHOWERS AND STORMS
FARTHER NORTH. HOWEVER THERE WILL BE A CHANCE FOR LOCALLY HEAVY
RAIN...AND A FLASH FLOOD THREAT...ESPECIALLY OVER THE HIGHER
TERRAIN. HIGH TEMPERATURES WILL BE A LITTLE LOWER...DUE TO
INCREASED CLOUD COVER AND LOWERING MID LEVEL TEMPERATURE.
SATURDAY...WITH THE MONSOON MOISTURE OVER THE AREA...ANOTHER DAY
WITH THE CHANCE FOR SHOWERS AND STORMS AND LOCALLY HEAVY
RAIN...AND THE THREAT FOR SOME FLASH FLOODING...AGAIN ESPECIALLY
OVER THE HIGHER TERRAIN. HIGH TEMPERATURES WILL TICK DOWN A LITTLE
MORE.
SUNDAY...GFS AND EUROPEAN MODELS SUGGEST THAT A FRONT WILL MOVE
ACROSS THE PLAINS EARLY...AND UPSLOPE FLOW WILL OCCUR AND
STRENGTHEN DURING THE DAY. SO SHOWERS AND STORMS WILL INITIATE
ACROSS THE HIGHER TERRAIN AND MOVE OUT INTO THE PLAINS DURING THE
EVENING AND OVERNIGHT.
THROUGH WEDNESDAY...MODELS SUGGEST THAT THE UPPER RIDGE WILL
REDEVELOP OVER THE ROCKIES. WITH SOME MONSOON MOISTURE IN
PLAY...AND UPSLOPE FLOW MONDAY AND TUESDAY ACROSS THE
PLAINS...THERE WILL BE DAILY CHANCES FOR SHOWERS AND
STORMS...DEVELOPING ACROSS THE HIGHER TERRAIN...WITH SOME SPREAD
INTO LOWER ELEVATIONS. -TLM-
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1121 AM MDT WED AUG 5 2015
VFR CONDITIONS ARE EXPECTED AT THE TAF SITES THROUGH THE END OF
THE PERIOD. SHOWERS AND THUNDERSTORMS WILL FORM OVER THE HIGHER
TERRAIN THIS AFTERNOON...BUT OVERALL COVERAGE AND ACTIVITY WILL BE
SPARSE...THEREFORE STORMS ARE UNLIKELY TO AFFECT THE TERMINALS.
WINDS WILL INCREASE OUT OF THE SOUTH TO SOUTHEAST AT AROUND 10-15
KTS FOR KCOS AND KPUB BEFORE SHIFTING TO A DIURNALLY DRIVEN
DRAINAGE FLOW OUT OF THE NORTHWEST TO WEST OVERNIGHT. KALS WILL
SEE WINDS OUT OF THE SW DURING THE AFTERNOON WITH SPEEDS GENERALLY
UNDER 15 KNOTS. LUKINBEAL
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KT
LONG TERM...TM
AVIATION...AL/PE
AREA FORECAST DISCUSSION
NWS PUEBLO CO
428 AM MDT WED AUG 5 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 428 AM MDT WED AUG 5 2015
...HOTTER TODAY WITH ONLY SPARSE AFTERNOON THUNDERSTORM ACTIVITY
POSSIBLE...
CONVECTION YESTERDAY WAS VIRTUALLY NIL ACROSS SOUTHERN
COLORADO...AND TODAY LOOKS QUITE SIMILAR...ALTHOUGH THERE ARE STILL
SOME FORECAST CHALLENGES TO DEAL WITH. FIRST IS THE PUSH OF LOW
LEVEL MOISTURE INTO THE SOUTHEAST PLAINS WHICH OCCURRED BEHIND AN
OUTFLOW BOUNDARY WHICH MOVED THROUGH LAST EVENING. 00Z RUNS DID NOT
ALL HAVE A GOOD HANDLE ON THIS DETAIL. OF THEM...NAM12 SEEMED TO DO
THE BEST...AND HRRR APPEARS TO HAVE CAUGHT ON AS WELL. NAM...HRRR
AND RAP13 ALL MIX OUT THIS SHALLOW LEVEL LEVEL MOISTURE ALONG THE I-
25 CORRIDOR AND ADJACENT EASTERN PLAINS DURING THE AFTERNOON...BUT
DIFFER WITH THE PERSISTENCE OF 50+ DEW POINTS FARTHER TO THE EAST
NEAR THE KS BORDER.
MEANWHILE...UPPER RIDGE ALOFT WILL HOLD FIRM AS TROF ACROSS CA RIDES
OVER THE TOP OF IT ACROSS THE NORTHERN GREAT BASIN AND WY LATE THIS
AFTERNOON THROUGH TONIGHT. THIS FEATURE WILL BRING A SLIGHT
INCREASE IN MOISTURE OVER CO AHEAD OF IT...THOUGH IT SHOULD BE
PRETTY MID AND HIGH BASED. SFC DEW POINTS ACROSS THE MOUNTAINS
SHOULD DROP BACK INTO THE 30S AND LOWER 40S AGAIN...WHICH SHOULD
KEEP ANY CONVECTION SPARSE AND HIGH BASED...THUS MORE LIKELY TO
PRODUCE ONLY SPOTTY LIGHT RAINFALL AT BEST...AND ERRATIC GUSTY WINDS
IF IT CAN GET GOING AT ALL. WILL CUT BACK POPS A BIT...BUT STILL
MAINTAIN PATCHY ISOLATED POPS ACROSS THE MOUNTAINS THIS AFTERNOON.
OTHER CHALLENGE AREA WILL BE ALONG A DRY LINE ACROSS SE CO. SOME OF
THE MODELS HINT AT DEVELOPING AN ISOLATED STORM OR TWO ACROSS THE
FAR EASTERN PLAINS LATE THIS AFTERNOON AND EVENING...MAINLY ACROSS
THE EASTERN MOST COUNTIES AND POTENTIALLY THE RATON RIDGE REGION.
CHANCES DO NOT LOOK ALL THAT GREAT...AS MAJORITY OF THE MODELS MIX
OUT THE LOW LEVEL MOISTURE INTO THE 40S AND LOWER 50S. EXCEPTION TO
THIS IS THE NAM WHICH HOLDS ON TO SOME LOWER 60 DEW POINTS ACROSS
BACA COUNTY. HRRR SEEMS TO BE TRENDING TOWARDS THE NAM12. HAVE
INTRODUCED SOME SILENT POPS OUT ACROSS THE FAR EAST PLAINS FOR NOW.
IF MODEL TRENDS CONTINUE...A LATER UPDATE MAY BE NEEDED TO BUMP POPS
UP A TAD. IF CAPES CAN STAY HIGH ENOUGH...AND SUFFICIENT
CONVERGENCE ALONG THE DRYLINE CAN INITIATE A THUNDERSTORM...THERE IS
A LOW POTENTIAL FOR A STRONG STORM IN THIS AREA...AS DEEP LAYER
SHEARS WILL BE RUNNING AROUND 35 KTS. BUT WE SEEM TO BE LACKING
MUCH OF A TRIGGER IN THE WAY OF A DISTURBANCE...AND MODELS TEND TO
OVERDO CONVECTIVE COVERAGE IN CASES LIKE THESE...SO WILL STICK WITH
SILENT POPS FOR NOW. THIS AGREES WELL WITH SPC DAY1 OUTLOOK FOR
NOW...WHICH DOESN`T HAVE THUNDER OUTLOOKED FOR THE FAR SOUTHEAST
PLAINS AT THIS POINT EITHER.
TONIGHT...ANY THUNDERSTORMS SHOULD DIMINISH QUICKLY WITH LOSS OF
HEATING. TEMPERATURES TONIGHT MAY BE MORE MILD FOR THE I-25
CORRIDOR DUE TO INCREASING WESTERLY DOWNSLOPE FLOW TOWARDS MORNING.
ELSEWHERE...CLEARING SKIES SHOULD ALLOW FOR ANOTHER NIGHT OF GOOD
RADIATIONAL COOLING FOR THE HIGH VALLEYS. -KT
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 428 AM MDT WED AUG 5 2015
...MONSOON MOISTURE RETURNS FOR THE WEEKEND AND BEYOND...
THURSDAY...WILL CONTINUE TO BE MAINLY DRY...WITH ABOVE NORMAL
TEMPERATURES...WITH THE UPPER RIDGE CENTERED OVER NEW MEXICO
PROVIDES FAIRLY DRY WESTERLY FLOW. MODELS PUTTING OUT ALMOST NO
RAINFALL...SO THE FORECAST WITH SILENT POPS TO LOW GRADE ISOLATED
OVER THE HIGHER TERRAIN LOOKS GOOD. MID LEVEL TEMPERATURES
FORECAST TO BE BELOW 20C...SO HIGHS WILL LIKELY BE AROUND 100
DEGREES F IN THE LOWER ARKANSAS VALLEY AND 90S ELSEWHERE ON THE
PLAINS. HIGHS IN THE 70S AND 80S ACROSS THE HIGH VALLEYS AND 50S
AND 60S ACROSS THE MOUNTAINS WILL BE REALIZED.
FRIDAY...TRANSITION BEGINS AS A SHORTWAVE OVER THE WESTERN US
NUDGES THE UPPER RIDGE EAST AND BRINGS THE MONSOON MOISTURE INTO
THE AREA LATER IN THE DAY AND OVERNIGHT. THE SHORTWAVE WILL LIKELY
BE FAR ENOUGH NORTH TO KEEP MAIN FOCUS OF SHOWERS AND STORMS
FARTHER NORTH. HOWEVER THERE WILL BE A CHANCE FOR LOCALLY HEAVY
RAIN...AND A FLASH FLOOD THREAT...ESPECIALLY OVER THE HIGHER
TERRAIN. HIGH TEMPERATURES WILL BE A LITTLE LOWER...DUE TO
INCREASED CLOUD COVER AND LOWERING MID LEVEL TEMPERATURE.
SATURDAY...WITH THE MONSOON MOISTURE OVER THE AREA...ANOTHER DAY
WITH THE CHANCE FOR SHOWERS AND STORMS AND LOCALLY HEAVY
RAIN...AND THE THREAT FOR SOME FLASH FLOODING...AGAIN ESPECIALLY
OVER THE HIGHER TERRAIN. HIGH TEMPERATURES WILL TICK DOWN A LITTLE
MORE.
SUNDAY...GFS AND EUROPEAN MODELS SUGGEST THAT A FRONT WILL MOVE
ACROSS THE PLAINS EARLY...AND UPSLOPE FLOW WILL OCCUR AND
STRENGTHEN DURING THE DAY. SO SHOWERS AND STORMS WILL INITIATE
ACROSS THE HIGHER TERRAIN AND MOVE OUT INTO THE PLAINS DURING THE
EVENING AND OVERNIGHT.
THROUGH WEDNESDAY...MODELS SUGGEST THAT THE UPPER RIDGE WILL
REDEVELOP OVER THE ROCKIES. WITH SOME MONSOON MOISTURE IN
PLAY...AND UPSLOPE FLOW MONDAY AND TUESDAY ACROSS THE
PLAINS...THERE WILL BE DAILY CHANCES FOR SHOWERS AND
STORMS...DEVELOPING ACROSS THE HIGHER TERRAIN...WITH SOME SPREAD
INTO LOWER ELEVATIONS. -TLM-
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 428 AM MDT WED AUG 5 2015
CONDITIONS WILL REMAIN VFR AT THE TAF SITES
TODAY...WITH SPARSE THUNDERSTORM ACTIVITY EXPECTED TO REMAIN TOO
ISOLATED AND THEREFORE UNLIKELY TO AFFECT THE TERMINALS. WINDS WILL
INCREASE FROM THE SOUTH TO SOUTHEAST AT AROUND 10-15 KTS FOR KCOS
AND KPUB DURING THE AFTERNOON BEFORE SHIFTING AROUND TO A DIURNALLY
DRIVEN NORTHWEST TO WEST WIND OVERNIGHT. KALS WILL SEE WINDS
INCREASE OUT OF THE SW DURING THE AFTERNOON WITH SPEEDS UNDER 15
KTS.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KT
LONG TERM...TM
AVIATION...KT
AREA FORECAST DISCUSSION
NWS ALBANY NY
404 PM EDT WED AUG 5 2015
.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE OVER QUEBEC WILL CONTINUE TO
ALLOW FOR A STRAY SHOWER THIS EVENING...ESPECIALLY FOR NORTHERN
AREAS. OTHERWISE...SKIES WILL BE PARTLY TO MOSTLY CLEAR WITH COOL
TEMPERATURES TONIGHT. DRY AND QUIET WEATHER IS EXPECTED INTO THE
UPCOMING WEEKEND WITH TEMPERATURES SLIGHTLY BELOW NORMAL...ALONG
WITH COMFORTABLE LEVELS OF HUMIDITY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
AS OF 404 PM EDT...A LARGE CLOSED OFF LOW AT 500 HPA IS SITUATED
DIRECTLY NORTH OF THE REGION OVER NORTH CENTRAL QUEBEC. THE TROUGH
AXIS HAS BEEN MOVING ACROSS OUR REGION THIS AFTERNOON...WHICH HAS
ALLOWED FOR SOME BRIEF ISOLATED RAIN SHOWERS TO DEVELOP. A FEW
ADDITIONAL RAIN SHOWERS ARE POSSIBLE THROUGH THE EARLY EVENING
HOURS...WITH THE BEST CHANCE ACROSS THE HIGH TERRAIN OF WESTERN
NEW ENGLAND AND ACROSS THE SOUTHERN AND WESTERN ADIRONDACKS. WILL
MENTION SLIGHT CHC OF THUNDER FOR THE NEXT FEW HOURS...BUT THUNDER
HAS BEEN HARD TO COME BY TODAY DUE TO LIMITED INSTABILITY.
THE 3KM HRRR SHOWS THUNDERSTORM ACTIVITY CURRENTLY NEAR LAKE
ONTARIO WILL WORK TOWARDS THE WESTERN ADIRONDACKS...BUT WILL START
TO DIMINISH LATER THIS EVENING WITH THE LOSS OF DAYTIME
HEATING...AND THE BEST FORCING SHIFTING NORTH AND EAST OF THE
REGION. AS A RESULT...WILL ALLOW POPS TO DROP OFF BY MIDNIGHT FOR
THE WHOLE AREA. CLOUDS WILL DIMINISH OVER THE AREA FOR THE
OVERNIGHT HOURS WITH SKIES BECOMING MOSTLY CLEAR FOR A GOOD
MAJORITY OF THE REGION. TEMPS LOOK COMFORTABLE AND COOL...WITH
LOWS MAINLY IN THE 50S. SOME UPPER 40S WILL BE POSSIBLE FOR THE
HIGHEST ELEVATIONS.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
DRY AND QUIET WEATHER IS ANTICIPATED FOR MUCH OF THE SHORT TERM
PERIOD. THE UPPER LEVEL LOW OVER QUEBEC WILL SHIFT TOWARDS
ATLANTIC CANADA ON THURSDAY. HEIGHTS WILL GRADUALLY START TO RISE
AT 500 HPA...ALTHOUGH A CONTINUED WEST TO NORTHWEST FLOW WILL KEEP
TEMPS SOMEWHAT ON THE COOLER SIDE.
A WEAK WAVE OVER THE TENNESSEE VALLEY WILL SHIFT TOWARDS THE MID
ATLANTIC COAST FOR THURSDAY NIGHT INTO FRIDAY. MODEL GUIDANCE IS
PRETTY CONSISTENT ON KEEPING THIS FEATURE SOUTH OF OUR AREA FOR
FRIDAY INTO FRIDAY NIGHT...SO WILL KEEP THE FORECAST DRY THROUGH
THIS TIME. SKY COVER GENERALLY LOOK PARTLY TO MOSTLY CLEAR.
HIGH TEMPS ON THURSDAY AND FRIDAY WILL MAINLY BE IN THE 70S...WITH
A FEW SPOTS NEAR 80 IN THE MID HUDSON VALLEY. OVERNIGHT LOWS LOOK
TO BE IN THE 50S...WITH SOME COOLER 40S FOR THE HIGH TERRAIN...ESP
OVER THE CENTRAL ADIRONDACKS. DEWPOINTS WILL BE VERY COMFORTABLE
EACH DAY...MAINLY IN THE 50S.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
THE LONG TERM PERIOD WILL START OUT RELATIVELY QUIET AS A COASTAL
STORM PASSES TO THE EAST OF THE REGION...BUT THEN BECOME
INCREASINGLY UNSETTLED HEADING INTO EARLY NEXT WEEK AS A FRONTAL
BOUNDARY IMPACTS THE REGION.
AT THE START OF THE LONG TERM PERIOD...THE FIRST HALF OF THE WEEKEND
LOOKS TO START ON AN EXCELLENT NOTE...WITH DRY WEATHER AND MOSTLY
SUNNY/PARTLY CLOUDY SKIES SATURDAY. MEANWHILE...A COASTAL STORM WILL
BE TAKING SHAPE OFF THE CAROLINA COAST...AND BEGIN TO TRACK
NORTHEAST UP THE EASTERN SEABOARD LATE SATURDAY INTO SATURDAY NIGHT.
BASED ON THE LATEST LONG RANGE GUIDANCE...THE OVERALL CONSENSUS IS
FOR THIS COASTAL STORM...WHICH LOOKS TO BECOME QUITE IMPRESSIVE FOR
EARLY AUGUST STANDARDS...IS THAT IT WILL TRACK FAR ENOUGH EAST OFF
THE COAST TO HAVE LIMITED IMPACTS ACROSS EASTERN NEW YORK AND
WESTERN NEW ENGLAND. REGARDLESS...THE 12Z ECMWF DOES HINT AT A
SLIGHTLY MORE WESTWARD TRACK...WHICH WOULD BRING THE WESTERN EDGE OF
RAIN SHOWERS INTO WESTERN NEW ENGLAND AND MAYBE FAR EASTERN NEW
YORK.
HAVE GONE WITH SLIGHT CHANCE POPS TO TAKE A BLENDED APPROACH
SATURDAY NIGHT THROUGH SUNDAY AS THERE STILL REMAINS UNCERTAINTY
REGARDING THE EXACT TRACK THAT THE COASTAL STORM WILL TAKE.
REGARDLESS OF THE EVENTUAL TRACK...THERE IS FAIRLY HIGH CONFIDENCE
THAT THE BULK OF THE PRECIPITATION ASSOCIATED WITH THE COASTAL STORM
WILL REMAIN EAST OF THE REGION AS IT TAKES A MILLER TYPE A
TRACK/SOUTHERN STREAM DOMINATED SYSTEM/EAST OF CAPE COD.
AS THE COASTAL STORM MOVES NORTHEAST INTO THE GULF OF MAINE SUNDAY
NIGHT THE REGION WILL BE SANDWICHED BETWEEN THE DEPARTING SYSTEM AND
AN APPROACHING FRONTAL BOUNDARY FROM THE GREAT LAKES REGION. IT
APPEARS THAT SUNDAY NIGHT...AND PERHAPS MOST OF MONDAY...WILL BE DRY
BEFORE THE WEATHER TURNS FOR THE WORSE MONDAY NIGHT.
HAVE GONE WITH CHANCE POPS MONDAY NIGHT THROUGH WEDNESDAY WITH THE
BEST CHANCE FOR PRECIPITATION TUESDAY INTO TUESDAY NIGHT AS THE
FRONTAL BOUNDARY MOVES ACROSS THE REGION. IN ITS WAKE LINGERING
SHOWERS WILL BE AROUND WITH A DEEPENING UPPER-LEVEL TROUGH ALOFT.
THE 12Z ECMWF STALLS THE FRONT JUST EAST OF THE REGION AND DEVELOPS
A WAVE OF LOW PRESSURE THAT WOULD BRING A SOAKING RAINFALL TO THE
REGION...WITH THE 12Z GFS HAVING A DRY SCENARIO. IT IS STILL TOO
EARLY TO TELL EXACTLY WHAT WILL HAPPEN BUT THERE IS HIGH CONFIDENCE
FOR UNSETTLED WEATHER FOR THE START OF NEXT WEEK.
HIGH TEMPERATURES THROUGHOUT THE LONG TERM PERIOD WILL GENERALLY
RANGE FROM THE LOW 70S TO LOW 80S...WITH A FEW UPPER 60S ACROSS THE
HIGH PEAKS OF THE SOUTHERN ADIRONDACKS AND SOUTHERN VERMONT. LOW
TEMPERATURES WILL GENERALLY RANGE FROM THE MID 50S TO LOW 60S.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
A BROAD UPPER LEVEL LOW WILL CONTINUE TO IMPACT ERN NY AND WRN
NEW ENGLAND TODAY INTO TONIGHT. JUST SOME ISOLATED TO SCATTERED
SHOWERS OVER THE REGION THIS AFTERNOON...AND INDICATING VCSH AT
KGFL...KALB... AND KPSF. CHANCES ARE MUCH LESS AT KPOU.
SCATTERED TO BROKEN CUMULUS WILL DEVELOP IN THE AFTERNOON. GENERALLY
SCATTERED-BROKEN AT 5000 FEET. THE LOSS OF THE DIURNAL
HEATING SHOULD ALLOW THE CLOUDS TO BURN OFF QUICKLY TOWARDS 00Z/THU.
SOME PATCHY MVFR/IFR MIST/FOG WILL BE POSSIBLE AT KGFL/KPSF
ESPECIALLY DEPENDING IF ANY RAINFALL OCCURS THIS AFTERNOON. OTHERWISE
SOME HIGH CLOUDS MAY DRIFT IN AFTER 06Z AT ALL THE TAF SITES.
THE WINDS WILL BE FROM THE WEST TO NORTHWEST AT 8-13 KT WITH SOME GUSTS
AROUND 20 KT AT KALB/KPSF. THE WINDS WILL DECREASE TO 10 KT OR LESS
TOWARDS 00Z/THU....AND BECOME LIGHT TO CALM AFTER MIDNIGHT. WINDS ARE
EXPECTED TO BE NORTHWEST AT LESS THAN 10 KTS TOMORROW MORNING.
OUTLOOK...
THURSDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
SATURDAY: NO OPERATIONAL IMPACT. NO SIG WX.
SATURDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
SUNDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
SUNDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
MONDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
&&
.FIRE WEATHER...
ASIDE FROM A STRAY SHOWER THIS EVENING...IT LOOKS DRY OVERNIGHT. RH
VALUES WILL BE 85 TO 100 PERCENT TONIGHT WITH SOME PATCHY FOG AND
DEW FORMATION. WINDS WILL BECOME LIGHT AND VARIABLE.
RH VALUES WILL DROP TO 35 TO 55 PERCENT ON BOTH THURSDAY AND
FRIDAY AFTERNOONS. THE LOWEST VALUES WILL BE ACROSS THE MID
HUDSON VALLEY AND NW CT. WEST TO NORTHWEST WINDS WILL BE AT 5 TO
10 MPH ON THURSDAY...AND NORTH TO NORTHEAST AROUND 5 MPH ON
FRIDAY.
&&
.HYDROLOGY...
NO HYDROLOGIC PROBLEMS ARE ANTICIPATED OVER THE NEXT FEW DAYS.
JUST A STRAY LOCALIZED SHOWER IS POSSIBLE THIS EVENING...MAINLY
FOR NORTHERN AREAS. OTHERWISE...DRY WEATHER IS EXPECTED TONIGHT AS
AN UPPER LEVEL DISTURBANCE MOVES AWAY FROM THE AREA. DRY WEATHER
WILL CONTINUE FOR THURSDAY INTO FRIDAY. JUST A STRAY LIGHT RAIN
SHOWER IS POSSIBLE OVER THE WEEKEND...WITH MOST AREAS STAYING
COMPLETELY DRY. THIS WILL ALLOW RIVER LEVELS TO REMAIN STEADY OR
SLOWLY FALL OVER THE NEXT FIVE DAYS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS
NEAR TERM...FRUGIS
SHORT TERM...FRUGIS
LONG TERM...IRL
AVIATION...NAS
FIRE WEATHER...FRUGIS
HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS NEW YORK NY
140 PM EDT WED AUG 5 2015
.SYNOPSIS...
WEAK HIGH PRESSURE BUILDS OVER THE AREA INTO THURSDAY. LOW
PRESSURE OVER NORTH CAROLINA THURSDAY NIGHT SLOWLY TRACKS EAST
NORTHEAST THOUGH THE WEEKEND REACHING THE GULF OF MAINE ON SUNDAY.
THIS SYSTEM SHOULD REMAIN OVER THE OPEN ATLANTIC AND NOT DIRECTLY
AFFECT OUR REGION. A WARM FRONT APPROACHES THE REGION FOR EARLY
NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FORECAST IS MAINLY ON TRACK WITH SOME DIURNAL CU FORMING FROM
DAYTIME HEATING THIS AFTERNOON ESPECIALLY ACROSS THE INTERIOR.
MAX TEMPERATURES WERE INCREASED A FEW DEGREES. THE GREATER
WESTERLY FLOW HAS AIDED DOWNSLOPING...ALLOWING COASTAL AREAS TO
REACH HIGHER TEMPERATURES WITH LESS MARINE INFLUENCE.
WEAK HIGH PRESSURE AT THE SURFACE WILL REMAIN OVER THE REGION.
ALOFT...A SHORTWAVE MOVING OUT OF THE GREAT LAKES REGION WILL MOVE
ACROSS THE REGION THIS AFTERNOON. DESPITE THE LIMITED
INSTABILITY...LATEST HI RES GUIDANCE INCLUDING THE HRRR AND 4-KM
NAM CONTINUE TO SUPPORT THE POTENTIAL FOR ISOLATED SHOWERS AND
THUNDERSTORMS LATE THIS AFTERNOON. WILL CONTINUE WITH LOW POPS TO
ACCOUNT FOR THIS.
HIGHS TODAY CLIMB INTO THE 80S AND LOWER 90S. MAV/MET GUIDANCE IN
GOOD AGREEMENT AND WAS USED FOR TEMPERATURES.
THERE IS A MODERATE RISK FOR RIP CURRENTS AT THE OCEAN BEACHES
TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
AN UPPER LEVEL SHORTWAVE WILL MOVE EAST OF THE REGION TONIGHT. AS
IT DOES...THE UPPER FLOW BECOMES MORE ZONAL. AT THE SURFACE...WEAK
HIGH PRESSURE WILL BUILD BACK INTO THE REGION FOR THE SHORT TERM.
EXPECT DRY CONDITIONS. LITTLE CLOUD COVER IS EXPECTED. USED A
BLEND OF MAV/MET MOS FOR TEMPERATURES. LOWS TONIGHT FALL INTO THE
50S AND 60S...WITH HIGHS ON THURSDAY IN THE 80S.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
MAJOR CHANGE TO THE FORECAST FOR FRIDAY. BASED ON ALL AVAILABLE
NWP GUIDANCE...IT APPEARS LIKELY THAT THE LOW PRESSURE SYSTEM WILL
REMAIN SOUTH AND EAST OF THE LOCAL AREA. HAVE LOWERED POPS TO 20
PERCENT (FROM LIKELY). HAVE ONLY KEPT THE 20 PERCENT TO ACCOUNT
FOR UNCERTAINTY FOR POSSIBILITY OF FLIP FLOP NWP...THOUGH THAT
WOULD SEEM VERY UNLIKELY. CALLED IT LIGHT RAIN AS AT WORSE WE`D BE
ON THE EXTREME NW PORTION OF THE SYSTEM.
21Z SREF...NCEP AND CANADIAN DETERMINISTIC RUNS ALONG WITH 00Z GEFS
ALL SUPPORT A DRY FCST. HAVE ALSO RAISE TEMPS FOR FRIDAY AS A
RESULT.
FLOW AROUND THE OFF SHORE LOW IS NORTHEAST FOR THE WEEKEND. THUS
TEMPS RUN ABOUT 5 DEGREES BELOW NORMAL.
A WARM FRONT APPROACHES FOR EARLY NEXT WEEK. MORE HUMID...BUT WITH
TEMPS REMAINING BELOW NORMAL. SHOWERS AND THUNDERSTORMS POSSIBLE.
LOW PRESSURE APPEARS POSSIBLE FOR MID WEEK...BUT WITH LOTS OF
UNCERTAINTY.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
WEAK SFC TROUGH PASSES THROUGH THE REGION THIS AFTERNOON...
FOLLOWED BY A WEAK UPPER DISTURBANCE THIS EVENING. ISOLATED
SHRA/TSRA POSSIBLE...BUT CONFIDENCE REMAINS TOO LOW TO WARRANT
MENTIONING IN THE TAF. WILL CARRY A VFR FORECAST...BUT AMDS
POSSIBLE IF SHRA/TSRA LOOKS TO IMPACT ANY GIVEN TERMINAL.
W-NW WINDS 10-15 KT WITH GUSTS UP TO 20 KT...POSSIBLY UP TO 23 KT
AT COASTAL TERMINALS WILL DIMINISH TO LESS THAN 10 KT THIS EVENING
AND SHIFT CLOSER TO THE NW BEHIND THE DEPARTING UPPER LEVEL
DISTURBANCE. WINDS THEN DIMINISH TO 5-10 KT ACROSS KNYC TERMINALS
AND TO 5 KT OR LESS ELSEWHERE. SEA BREEZE WITH SW FLOW HAS
DEVELOPED AT KBDR/KGON...BUT WINDS WILL SHIFT GOING INTO THE
AFTERNOON BEHIND PASSAGE OF SFC TROUGH.
WINDS WILL BACK TO THE SW LATE THURSDAY MORNING WITH SEA BREEZES
POSSIBLE AT COASTAL TERMINALS THURSDAY AFTERNOON.
...NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS
CAN BE FOUND AT: HTTP://WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: TIMING OF WIND SHIFT AT 00Z COULD BE OFF BY
AN HOUR OR SO.
KLGA FCSTER COMMENTS: TIMING OF WIND SHIFT AT 00Z COULD BE OFF BY
AN HOUR OR SO.
KEWR FCSTER COMMENTS: TIMING OF WIND SHIFT AT 00Z COULD BE OFF BY
AN HOUR OR SO.
KTEB FCSTER COMMENTS: TIMING OF WIND SHIFT AT 00Z COULD BE OFF BY
AN HOUR OR SO.
KHPN FCSTER COMMENTS: TIMING OF WIND SHIFT AT 00Z COULD BE OFF BY
AN HOUR OR SO.
KISP FCSTER COMMENTS: TIMING OF WIND SHIFT THIS EVENING COULD BE
OFF BY AN HOUR OR SO.
.OUTLOOK FOR 18Z THURSDAY THROUGH MONDAY...
.THURSDAY AFTERNOON...VFR. WINDS SHIFT FROM NW TO SW AT 10 KT OR
LESS. SEA BREEZES POSSIBLE AT COASTAL TERMINALS.
.THURSDAY NIGHT...VFR. DIMINISHING WINDS.
.FRIDAY...SLIGHT CHANCE FOR LIGHT RAIN ACROSS SOUTHERN TERMINALS.
.SATURDAY...SUB-VFR POSSIBLE IN -RA. INCREASING NE WINDS.
.SUNDAY...VFR.
.MONDAY...MAINLY VFR. CHANCE FOR SHRA/TSRA LATE.
&&
.MARINE...
FORECAST REMAINS MAINLY ON TRACK. EXPECTING OCEAN SEAS TO STAY
BELOW 5 FT WITH THE WESTERLY FLOW THIS AFTERNOON. THE WEAK
PRESSURE GRADIENT OVER THE AREA WATERS WILL ALLOW FOR THESE SUB-
SCA CONDITIONS. THESE SUB-SCA CONDITIONS ARE EXPECTED TO CONTINUE
INTO THURSDAY.
LONG TERM...LOW PRESSURE PASSES SOUTH AND EAST OF THE REGION FRIDAY
THROUGH THE WEEKEND. NE FLOW IS EXPECT FOR THE PERIOD. WINDS INCREASE
TO PERHAPS MINIMAL SMALL CRAFT LEVELS (GUSTS TO 25 KT)...THOUGH THIS
MAY BE TOO HIGH. SEAS THOUGH ON THE OCEAN WILL BUILD TO 4 TO 7 FT.
&&
.HYDROLOGY...
ORGANIZED SIGNIFICANT RAINFALL IS NOT EXPECTED THROUGH THE
WEEKEND.
&&
.EQUIPMENT...
TEWR TERMINAL DOPPLER RADAR REMAINS UNAVAILABLE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...BC/TONGUE
NEAR TERM...BC/TONGUE
SHORT TERM...BC
LONG TERM...TONGUE
AVIATION...MPS
MARINE...BC/TONGUE
HYDROLOGY...BC/TONGUE
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1041 AM EDT WED AUG 5 2015
.SYNOPSIS...
WEAK HIGH PRESSURE BUILDS OVER THE AREA INTO THURSDAY. LOW
PRESSURE OVER NORTH CAROLINA THURSDAY NIGHT SLOWLY TRACKS EAST
NORTHEAST THOUGH THE WEEKEND REACHING THE GULF OF MAINE ON SUNDAY.
THIS SYSTEM SHOULD REMAIN OVER THE OPEN ATLANTIC AND NOT DIRECTLY
AFFECT OUR REGION. A WARM FRONT APPROACHES THE REGION FOR EARLY
NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FORECAST IS ON TRACK WITH THE CIRRUS MOVING EAST LATE THIS
MORNING INTO THE EARLY AFTERNOON LEAVING BEHIND MOSTLY SUNNY
SKIES. HOWEVER...DO EXPECT SOME DIURNAL CU WITH DAYTIME HEATING
THIS AFTERNOON ESPECIALLY ACROSS THE INTERIOR. FORECAST
TEMPERATURES AND DEWPOINTS WERE GENERALLY WITHIN A FEW DEGREES OF
OBSERVED VALUES SO THESE WERE NOT CHANGED TOO MUCH.
WEAK HIGH PRESSURE AT THE SURFACE WILL REMAIN OVER THE REGION
TODAY. ALOFT...A SHORTWAVE MOVING OUT OF THE GREAT LAKES REGION
WILL MOVE ACROSS THE REGION THIS AFTERNOON. DESPITE THE LIMITED
INSTABILITY...LATEST HI RES GUIDANCE INCLUDING THE HRRR AND 4-KM NAM
CONTINUE TO SUPPORT THE POTENTIAL FOR ISOLATED SHOWERS AND
THUNDERSTORMS THIS AFTERNOON. WILL CONTINUE WITH LOW POPS TO
ACCOUNT FOR THIS.
HIGHS TODAY CLIMB INTO THE 80S AND LOWER 90S. MAV/MET GUIDANCE IN
GOOD AGREEMENT AND WAS USED FOR TEMPERATURES.
THERE IS A MODERATE RISK FOR RIP CURRENTS AT THE OCEAN BEACHES
TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
AN UPPER LEVEL SHORTWAVE WILL MOVE EAST OF THE REGION TONIGHT. AS
IT DOES...THE UPPER FLOW BECOMES MORE ZONAL. AT THE SURFACE...WEAK
HIGH PRESSURE WILL BUILD BACK INTO THE REGION FOR THE SHORT TERM.
EXPECT DRY CONDITIONS. LITTLE CLOUD COVER IS EXPECTED. USED A
BLEND OF MAV/MET MOS FOR TEMPERATURES. LOWS TONIGHT FALL INTO THE
50S AND 60S...WITH HIGHS ON THURSDAY IN THE 80S.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
MAJOR CHANGE TO THE FORECAST FOR FRIDAY. BASED ON ALL AVAILABLE
NWP GUIDANCE...IT APPEARS LIKELY THAT THE LOW PRESSURE SYSTEM WILL
REMAIN SOUTH AND EAST OF THE LOCAL AREA. HAVE LOWERED POPS TO 20
PERCENT (FROM LIKELY). HAVE ONLY KEPT THE 20 PERCENT TO ACCOUNT
FOR UNCERTAINTY FOR POSSIBILITY OF FLIP FLOP NWP...THOUGH THAT
WOULD SEEM VERY UNLIKELY. CALLED IT LIGHT RAIN AS AT WORSE WE`D BE
ON THE EXTREME NW PORTION OF THE SYSTEM.
21Z SREF...NCEP AND CANADIAN DETERMINISTIC RUNS ALONG WITH 00Z GEFS
ALL SUPPORT A DRY FCST. HAVE ALSO RAISE TEMPS FOR FRIDAY AS A
RESULT.
FLOW AROUND THE OFF SHORE LOW IS NORTHEAST FOR THE WEEKEND. THUS
TEMPS RUN ABOUT 5 DEGREES BELOW NORMAL.
A WARM FRONT APPROACHES FOR EARLY NEXT WEEK. MORE HUMID...BUT WITH
TEMPS REMAINING BELOW NORMAL. SHOWERS AND THUNDERSTORMS POSSIBLE.
LOW PRESSURE APPEARS POSSIBLE FOR MID WEEK...BUT WITH LOTS OF
UNCERTAINTY.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
NO SIGNIFICANT CHANGES MADE TO PREVIOUS TAF PACKAGE. WILL UPDATE
INITIAL GROUP BASED ON LATEST SFC OBS AND SATELLITE TRENDS.
OTHERWISE...VFR FORECAST HIGH BUILDS OVER THE TERMINALS. A WEAK
UPPER LEVEL DISTURBANCE MAY TOUCH OFF A FEW LATE DAY/EVENING
SHRA/TSRA...BUT CONFIDENCE AND COVERAGE IS TOO LOW TO PUT IN THE
TAFS.
W-NW WINDS 5-10 KT WILL BACK TO THE WEST AND INCREASE TO 10-15 KT
WITH OCNL GUSTS UP TO 20 KT THIS AFTERNOON. NW WINDS DIMINISH TO
5-10 KT TONIGHT. SW SEA BREEZE AT KGON WILL GIVE WAY TO W WINDS IN
THE AFTERNOON.
...NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS
CAN BE FOUND AT: HTTP://WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: LOW CHANCE FOR A SEA BREEZE PRIOR TO 18Z.
TIMING OF GUSTS MAY BE OFF BY +/- AN HOUR.
KLGA FCSTER COMMENTS: TIMING OF GUSTS MAY BE OFF BY +/- AN HOUR.
KEWR FCSTER COMMENTS: TIMING OF GUSTS MAY BE OFF BY +/- AN HOUR.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: TIMING OF GUSTS MAY BE OFF BY +/- AN HOUR.
KHPN FCSTER COMMENTS: TIMING OF GUSTS MAY BE OFF BY +/- AN HOUR.
KISP FCSTER COMMENTS: TIMING OF GUSTS MAY BE OFF BY +/- AN HOUR.
LOW CHANCE OF A SEA BREEZE PRIOR TO 18Z.
.OUTLOOK FOR 15Z THU THROUGH SUNDAY...
.THU-FRI...VFR. SLIGHT CHANCE OF A SHOWER ON FRI.
.SAT...VFR. NE WIND GUSTS 15-20 KT.
.SUNDAY...VFR.
&&
.MARINE...
FORECAST REMAINS MAINLY ON TRACK. WATCHING BUOYS ON OUTER OCEAN
WITH SEAS JUST BELOW 5 FT. EXPECTING THESE SEAS TO STAY BELOW 5 FT
WITH THE WESTERLY FLOW THIS AFTERNOON. HOWEVER...IF WINDS BECOME
MORE SOUTHERLY...THEN THE SEAS COULD BRIEFLY GET TO 5 FT INTO
THIS AFTERNOON.
OTHERWISE...THE WEAK PRESSURE GRADIENT OVER THE AREA WATERS WILL
ALLOW FOR SUB-SCA CONDITIONS. THESE SUB-SCA CONDITIONS ARE
EXPECTED TO CONTINUE INTO THURSDAY.
LONG TERM...LOW PRESSURE PASSES SOUTH AND EAST OF THE REGION FRIDAY
THROUGH THE WEEKEND. NE FLOW IS EXPECT FOR THE PERIOD. WINDS INCREASE
TO PERHAPS MINIMAL SMALL CRAFT LEVELS (GUSTS TO 25 KT)...THOUGH THIS
MAY BE TOO HIGH. SEAS THOUGH ON THE OCEAN WILL BUILD TO 4 TO 7 FT.
&&
.HYDROLOGY...
ORGANIZED SIGNIFICANT RAINFALL IS NOT EXPECTED THROUGH THE
WEEKEND.
&&
.EQUIPMENT...
TEWR TERMINAL DOPPLER RADAR REMAINS UNAVAILABLE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...BC/TONGUE
NEAR TERM...BC/TONGUE
SHORT TERM...BC
LONG TERM...TONGUE
AVIATION...MPS
MARINE...BC/TONGUE
HYDROLOGY...BC/TONGUE
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS NEW YORK NY
706 AM EDT WED AUG 5 2015
.SYNOPSIS...
WEAK HIGH PRESSURE BUILDS OVER THE AREA INTO THURSDAY. LOW
PRESSURE OVER NORTH CAROLINA THURSDAY NIGHT SLOWLY TRACKS EAST
NORTHEAST THOUGH THE WEEKEND REACHING THE GULF OF MAINE ON SUNDAY.
THIS SYSTEM SHOULD REMAIN OVER THE OPEN ATLANTIC AND NOT DIRECTLY
AFFECT OUR REGION. A WARM FRONT APPROACHES THE REGION FOR EARLY
NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
INCREASED CLOUD COVER THIS MORNING AS A FAIRLY THICK CIRRUS SHIELD
IS MOVING OVERHEAD. THIS IS IN ASSOCIATION WITH A 100 KT 300 MB
JET MOVING ACROSS NEW ENGLAND. THINKING THE CIRRUS MOVES EAST LATE
THIS MORNING INTO THE EARLY AFTERNOON LEAVING BEHIND MOSTLY SUNNY
SKIES.
WEAK HIGH PRESSURE AT THE SURFACE WILL REMAIN OVER THE REGION
TODAY. ALOFT...A SHORTWAVE MOVING OUT OF THE GREAT LAKES REGION
WILL MOVE ACROSS THE REGION THIS AFTERNOON. DESPITE THE LIMITED
INSTABILITY...LATEST HI RES GUIDANCE INCLUDING THE HRRR AND 4-KM NAM
CONTINUE TO SUPPORT THE POTENTIAL FOR ISOLATED SHOWERS AND
THUNDERSTORMS THIS AFTERNOON. WILL CONTINUE WITH LOW POPS TO
ACCOUNT FOR THIS.
HIGHS TODAY CLIMB INTO THE 80S AND LOWER 90S. MAV/MET GUIDANCE IN
GOOD AGREEMENT AND WAS USED FOR TEMPERATURES.
THERE IS A MODERATE RISK FOR RIP CURRENTS AT THE OCEAN BEACHES
TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
AN UPPER LEVEL SHORTWAVE WILL MOVE EAST OF THE REGION TONIGHT. AS
IT DOES...THE UPPER FLOW BECOMES MORE ZONAL. AT THE SURFACE...WEAK
HIGH PRESSURE WILL BUILD BACK INTO THE REGION FOR THE SHORT TERM.
EXPECT DRY CONDITIONS. LITTLE CLOUD COVER IS EXPECTED. USED A
BLEND OF MAV/MET MOS FOR TEMPERATURES. LOWS TONIGHT FALL INTO THE
50S AND 60S...WITH HIGHS ON THURSDAY IN THE 80S.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
MAJOR CHANGE TO THE FORECAST FOR FRIDAY. BASED ON ALL AVAILABLE
NWP GUIDANCE...IT APPEARS LIKELY THAT THE LOW PRESSURE SYSTEM WILL
REMAIN SOUTH AND EAST OF THE LOCAL AREA. HAVE LOWERED POPS TO 20
PERCENT (FROM LIKELY). HAVE ONLY KEPT THE 20 PERCENT TO ACCOUNT
FOR UNCERTAINTY FOR POSSIBILITY OF FLIP FLOP NWP...THOUGH THAT
WOULD SEEM VERY UNLIKELY. CALLED IT LIGHT RAIN AS AT WORSE WE`D BE
ON THE EXTREME NW PORTION OF THE SYSTEM.
21Z SREF...NCEP AND CANADIAN DETERMINISTIC RUNS ALONG WITH 00Z GEFS
ALL SUPPORT A DRY FCST. HAVE ALSO RAISE TEMPS FOR FRIDAY AS A
RESULT.
FLOW AROUND THE OFF SHORE LOW IS NORTHEAST FOR THE WEEKEND. THUS
TEMPS RUN ABOUT 5 DEGREES BELOW NORMAL.
A WARM FRONT APPROACHES FOR EARLY NEXT WEEK. MORE HUMID...BUT WITH
TEMPS REMAINING BELOW NORMAL. SHOWERS AND THUNDERSTORMS POSSIBLE.
LOW PRESSURE APPEARS POSSIBLE FOR MID WEEK...BUT WITH LOTS OF
UNCERTAINTY.
&&
.AVIATION /11Z WEDNESDAY THROUGH SUNDAY/...
VFR AS HIGH BUILDS OVER THE TERMINALS TODAY.
LIGHT AND VARIABLE WINDS AT THE START OF THE TAF PERIOD GIVE WAY
TO NW WINDS 5-10 KT LATE THIS MORNING. WINDS BACK TO THE W-WNW THIS
AFTERNOON WITH SPEEDS 10-15 KT AND GUSTS UP TO 20 KT. SW SEA
BREEZE ONLY ONLY FORECAST AT KGON.
A BRIEF SHRA/TSRA IS POSSIBLE THIS AFTERNOON.
WNW-NW WINDS DIMINISH THIS EVENING AND OVERNIGHT.
...NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP://WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: TIMING OF GUSTS MAY BE OFF BY +/- AN HOUR. LOW
CHANCE OF A SEA BREEZE THIS AFTERNOON.
KLGA FCSTER COMMENTS: TIMING OF GUSTS MAY BE OFF BY +/- AN HOUR.
KEWR FCSTER COMMENTS: TIMING OF GUSTS MAY BE OFF BY +/- AN HOUR.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: TIMING OF GUSTS MAY BE OFF BY +/- AN HOUR.
KHPN FCSTER COMMENTS: TIMING OF GUSTS MAY BE OFF BY +/- AN HOUR.
KISP FCSTER COMMENTS: TIMING OF GUSTS MAY BE OFF BY +/- AN HOUR. LOW
CHANCE OF A SEA BREEZE THIS AFTERNOON.
.OUTLOOK FOR 12Z THU THROUGH SUNDAY...
.THU-FRI...VFR. SLIGHT CHANCE OF A SHOWER ON FRI.
.SAT...VFR. NE WIND GUSTS 15-20 KT.
.SUNDAY...VFR.
&&
.MARINE...
A WEAK PRESSURE GRADIENT OVER THE AREA WATERS WILL ALLOW SEAS TO
CONTINUE TO SUBSIDE TODAY. THESE SUB-SCA CONDITIONS ARE EXPECTED
TO CONTINUE INTO THURSDAY.
LONG TERM...LOW PRESSURE PASSES SOUTH AND EAST OF THE REGION FRIDAY
THROUGH THE WEEKEND. NE FLOW IS EXPECT FOR THE PERIOD. WINDS INCREASE
TO PERHAPS MINIMAL SMALL CRAFT LEVELS (GUSTS TO 25 KT)...THOUGH THIS
MAY BE TOO HIGH. SEAS THOUGH ON THE OCEAN WILL BUILD TO 4 TO 7 FT.
&&
.HYDROLOGY...
ORGANIZED SIGNIFICANT RAINFALL IS NOT EXPECTED THROUGH THE
WEEKEND.
&&
.EQUIPMENT...
TEWR TERMINAL DOPPLER RADAR REMAINS UNAVAILABLE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...BC/TONGUE
NEAR TERM...BC/TONGUE
SHORT TERM...BC
LONG TERM...TONGUE
AVIATION...DS
MARINE...BC/TONGUE
HYDROLOGY...BC/TONGUE
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
957 AM EDT WED AUG 5 2015
.DISCUSSION...
TODAY/TONIGHT...LIGHTER WIND REGIME INDICATED WITH ATLANTIC RIDGE
AXIS BUILDING ACROSS SOUTHERN SECTIONS. THERE IS STILL LIGHT
SOUTHWEST FLOW ACROSS NORTHERN SECTIONS BUT SOUTH OF CANAVERAL WE
EXPECT THE SEA BREEZE TO PUSH INLAND A LITTLE SOONER THAN YESTERDAY.
WITH RESPECT TO MOISTURE...WE SHOULD INITIALLY BE UNDER THE INFLUENCE
OF A DRIER RIBBON WORKING AROUND THE SURFACE RIDGE. THE BLENDED
TOTAL PRECIP WATER PRODUCT INDICATES HIGHER MOISTURE AROUND 2 INCHES
FOLLOWING THAT AND AFFECTING SOUTHERN SECTIONS THIS AFTERNOON.
THE HRRR MODEL AND LOCAL WRF SHOW CONVECTION SPREADING OUT OF SOUTH
FLORIDA THIS AFTERNOON. BOUNDARY INTERACTIONS SHOULD BE STRONGEST
OVER THE SOUTH INTERIOR WHERE OUR HIGHEST POPS ARE (40-50 PERCENT).
WOULD EXPECT SCATTERED COVERAGE (30 PERCENT) DEVELOPING IN THE
NORTH...PROBABLY LATER IN THE DAY THOUGH AS BOUNDARY INTERACTIONS...
PARTICULARLY EAST/WEST MERGER...ARE DELAYED MORE THERE.
MID LEVEL TEMPS LOOK TYPICAL FOR THIS TIME OF THE YEAR WITH MINUS 6
TO 7 CELSIUS AT 500MB. WHILE SOME DRIER AIR ALOFT EXISTS...THE
MICROBURST THREAT LOOKS SUB-SEVERE AND THE MAIN HAZARD WILL BE
FREQUENT LIGHTNING STRIKES WHERE THE STRONGEST BOUNDARY COLLISIONS
OCCUR.
&&
.AVIATION...
VFR THROUGH THE MORNING. HIGHEST COVERAGE OF AFTERNOON STORMS SHOULD
BE INLAND OF MLB-VRB-FPR-SUA...BUT VICINITY THUNDER MAY BECOME
NECESSARY AS SOUTHWEST STEERING FLOW STILL EXISTS. WILL LEAVE
VICINITY THUNDER MENTION FOR THE INTERIOR SITES AND DAB...THOUGH
THE SHORT RANGE MODELS INDICATE THIS WILL PROBABLY BE A LITTLE LATER
THAN 19Z.
&&
.MARINE...
TODAY-TONIGHT...RIDGE AXIS WILL LINGER NEAR TO JUST NORTH OF LAKE
OKEECHOBEE WITH LIGHTER S/SW GRADIENT WINDS RESULTING (10 KNOTS OR
LESS). THIS WILL PRODUCE RATHER BENIGN SEAS 1-2 FEET NEAR SHORE AND
2-3 FEET WELL OFFSHORE. STORMS THAT FORM ALONG THE EAST COAST SEA
BREEZE THIS AFTERNOON AND EVENING COULD PUSH ACROSS THE COAST AND
BRING A THREAT FOR GUSTY WINDS 30-35 KNOTS AND FREQUENT LIGHTNING
STRIKES.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
FORECASTS...LASCODY
IMPACT WX...SPRATT
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
940 AM EDT WED AUG 5 2015
.FOR THE MORNING UPDATE...
BROAD U/L RIDGE EXTENDS FROM THE DESERT SOUTHWEST ACROSS THE
SOUTHERN TIER OF THE U.S. AND FLORIDA TO OVER THE WESTERN
ATLANTIC. SURFACE RIDGE AXIS OVER THE WESTERN ATLANTIC NOW EXTENDS
ACROSS THE CENTRAL FLORIDA PENINSULA. 12Z TBW SOUNDING INDICATES
DRYING ALOFT DUE IN PART TO THE STRONG U/L RIDGE NOW OVER THE
AREA WITH PCPW DOWN TO 1.63 INCHES. W/V IMAGERY ALSO INDICATES A
POCKET OF DRIER AIR ALOFT NOW OVER WEST CENTRAL FLORIDA.
BOUNDARY LAYER WINDS REMAIN ONSHORE OVER THE NATURE COAST ON THE
NORTH SIDE OF THE RIDGE AXIS WITH SOUTHEAST WINDS ACROSS SOUTHWEST
FLORIDA ON THE SOUTH SIDE OF THE RIDGE AXIS. SLIGHTLY DEEPER
MOISTURE OVER SOUTHWEST FLORIDA COMBINED WITH THE SOUTHEAST FLOW
WHICH WILL HOLD THE WEST COAST SEA BREEZE CLOSER TO THE COAST
CREATING BETTER L/L CONVERGENCE ALONG WITH INCREASED ATMOSPHERIC
INSTABILITY ALL POINT TO BEST CHANCE OF AFTERNOON SHOWERS AND
THUNDERSTORMS OVER SOUTHWEST FLORIDA. AS WEST COAST SEA BREEZE
PUSHES INLAND DURING THE MID TO LATE AFTERNOON...SCATTERED
THUNDERSTORMS WILL SPREAD OVER THE INTERIOR AND INCREASE IN AREAL
COVERAGE.
LOW END SCATTERED POPS ALSO OVER WEST CENTRAL FLORIDA AND THE
NATURE COAST WITH BEST CHANCE OF THUNDERSTORMS DURING THE LATE
MORNING THROUGH MID AFTERNOON. ONSHORE FLOW TO THE NORTH WILL PUSH
ACTIVITY INLAND DURING THE AFTERNOON HOURS...WHILE WEAK BOUNDARY
LAYER FLOW NEAR THE SURFACE RIDGE AXIS OVER WEST CENTRAL FLORIDA
WILL DECREASE L/L CONVERGENCE ALLOWING ONLY LOW END SCATTERED
THUNDERSTORM ACTIVITY WITH AGAIN THE BEST CHANCE DURING THE LATE
MORNING THROUGH MID AFTERNOON...WITH ACTIVITY GRADUALLY PUSHING
INLAND ALONG THE WEST COAST SEA BREEZE BOUNDARY AS ONSHORE FLOW
DEVELOPS. HRRR ALSO IN GOOD AGREEMENT WITH OVERALL EVOLUTION OF
THUNDERSTORM ACTIVITY THROUGH THE DAY.
BASED ON THIS...WILL UP POPS SLIGHTLY FOR SOUTHWEST FLORIDA AND
THE INTERIOR.
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
UPDATE/AVIATION/FIRE WEATHER...13/OGLESBY
MARINE...13/OGLESBY
DECISION SUPPORT...05/CARLISLE
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
338 AM EDT WED AUG 5 2015
.Near Term [Through Today]...
The overnight analysis shows weak flow across the local area,
typical of summertime. The airmass is moist with PWAT values near
to slightly above average. Once again like last night, the 00z GFS
appears to have surface dewpoints too low in its 6 hour forecast
across portions of east-central Alabama by as much as 10 degrees
with smaller errors of a couple of degrees closer to our area.
For today, southwest flow in the low levels is expected to keep
the boundary layer moist and the GFS seems too dry again. There
may be evidence of a weak perturbation in the flow along the
northern Gulf coast with some convection noted off the MS/AL
coastline. This convection is expected to propagate eastward
through the morning hours while gradually expanding in coverage,
resulting in likely PoPs for most of the western portions of the
area today. The 04z HRRR run seemed to be a good guide to follow
through the morning hours with some other local CAM guidance in
general agreement along with the two NCEP CAMs. With an early
start to convection across the Florida panhandle, high
temperatures are expected to be around 90 with mid 90s farther to
the east.
.Short Term [Tonight Through Friday]...
As the latter half of the work week approaches, an upper trough
will deepen over the eastern half of the country as a fairly
potent shortwave digs into the Tennessee River Valley. The
approach of this trough along with moist west/southwest low-level
flow will keep rain chances at or above climo for Thursday and
Friday. Increasing mid-level northwesterly flow on Friday may help
to fuel some stronger storms, with SPC outlooking the area with a
marginal risk for severe storms.
.Long Term [Friday Night Through Wednesday]...
To start th extended period, the area will be situated between an
upper ridge over the Southern Plains and an upper trough along the
Eastern Seaboard. Could see an active convective day on Saturday
as a disturbance moves south towards the forecast area in the
northerly mid-level flow.
Thereafter, the upper ridge is forecast to build eastward into the
early part of next week. This should lead to a gradual decrease in
precip coverage with temperatures remaining slightly above
normal.
&&
.Aviation...
[Through 06Z Thursday] Mainly VFR conditions are expected, but a
brief period of LIFR cigs is possible at VLD around dawn. Scattered
TSRA are expected to develop during the morning hours near the coast
and push inland through the afternoon.
&&
.Marine...
Southwesterly flow will be slightly elevated through Saturday.
However, winds are expected to remain below headline criteria.
Winds ands seas will diminish late in the weekend into early next
week.
&&
.Fire Weather...
Warm and humid conditions will continue for the next several days
with scattered convection.
&&
.Hydrology...
The Steinhatchee River has crested and is now slowly falling. It
is expected that the river will remain above flood stage for at
least the next few days, likely dropping below flood stage on
Friday morning.
With mainly scattered afternoon and evening storms the next few
days, do not anticipate any additional river flood concerns.
However, areas in the Southeast Florida Big Bend, particularly in
Dixie County, will be especially prone to further areal flooding,
should any storms move over the area during the next couple of
days.
&&
.Preliminary Point Temps/PoPs...
Tallahassee 94 75 91 75 91 / 50 20 50 20 60
Panama City 87 78 87 79 88 / 60 30 40 20 50
Dothan 92 75 90 74 92 / 60 30 50 30 50
Albany 93 75 91 75 92 / 50 20 50 30 60
Valdosta 92 74 92 75 92 / 50 20 50 20 60
Cross City 92 73 91 75 89 / 40 20 30 20 50
Apalachicola 90 78 88 78 90 / 30 20 30 20 50
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AL...NONE.
GM...NONE.
&&
$$
NEAR TERM...DVD
SHORT TERM...CAMP
LONG TERM...CAMP
AVIATION...DVD
MARINE...CAMP
FIRE WEATHER...DVD
HYDROLOGY...CAMP
AREA FORECAST DISCUSSION
NWS LINCOLN IL
256 PM CDT WED AUG 5 2015
.SHORT TERM...(TONIGHT)
ISSUED AT 255 PM CDT WED AUG 5 2015
RATHER DIFFUSE WEATHER PATTERN OVER MUCH OF THE MIDWEST. HIGH
PRESSURE RIDGE IS OVER THE WESTERN HALF OF THE COUNTRY...WITH AN MCS
MAKING ITS WAY ACROSS THE MID MISSISSIPPI RIVER VALLEY. GENERAL
CONSENSUS OF THE MODELS HAVE BEEN TRENDING PRECIP ALONG A QUASI
BOUNDARY ACROSS THE SOUTHERN TIER OF THE STATE...ALTHOUGH THERE HAS
BEEN SOME QUESTION AS TO WHERE THIS PARTICULAR FEATURE WILL SET UP.
SHORT TERM MODELS HAVE BEEN ENHANCING THAT ACTIVITY AS THE MCV FROM
THE ACTIVITY IN CENTRAL MO MAKES ITS WAY TO THE EAST. WITH THE
MODELS TRENDING FURTHER SOUTH, HAVE SOME CONCERNS AS TO GOING TOO
FAR NORTH WITH THE HIGHER PRECIPITATION CHANCES. WITH PRECIPITATION
ABSENT IN THE NORTHERN HALF OF THE CWA, AND POTENTIALLY FURTHER
SOUTH, THE MODELS HAVE OVERDONE SOME OF THE BOUNDARY LAYER MOISTURE.
HAVE DROPPED THE DEWPOINTS A FEW DEGREES TO COUNTER THIS NORTH OF I-
72.
&&
.LONG TERM...(THURSDAY THROUGH WEDNESDAY)
ISSUED AT 255 PM CDT WED AUG 5 2015
SHOWER/STORM CHANCES MAY LINGER TO START THE DAY, MAINLY ACROSS THE
SOUTHERN PORTION OF THE FORECAST AREA, UNTIL A WAVE MOVING OUT OF THE
CENTRAL PLAINS PUSHES EAST OF THE AREA. HOWEVER, AT THIS POINT, THE
BULK OF THE UPSTREAM PRECIPITATION IS TIED TO A MCV MOVING ACROSS
MISSOURI. IF THIS TREND CONTINUES, MOST OF THURSDAY WILL WIND UP
BEING DRY.
BEHIND THIS INITIAL SYSTEM, DRY WEATHER HAD BEEN ANTICIPATED UNTIL
AT LEAST SATURDAY NIGHT/SUNDAY AS UPPER LEVEL RIDGING WAS PROGGED TO
BUILD INTO THE AREA. HOWEVER, MODELS ARE SUGGESTING THAT A STRONGER
WAVE MAY TRACK DOWN THE BACK SIDE OF THE RIDGE THURSDAY NIGHT INTO
FRIDAY NIGHT, POSSIBLY WITH AN ACCOMPANYING RISK OF SHOWERS/STORMS.
THE BEST CHANCES WITH THIS FEATURE APPEAR TO BE THURSDAY NIGHT
UPSTREAM ACROSS THE MIDWEST WITH A DECENT LOW LEVEL JET FOCUSED INTO
THE AREA. THE DIURNAL WEAKENING OF THIS JET, COUPLED WITH THE
SHEARING OUT OF THE WAVE, SHOULD KEEP RAIN CHANCES ON THE LOW SIDE
LOCALLY.
UPSTREAM MCS DEVELOPMENT MAY OCCUR SATURDAY NIGHT, ALTHOUGH GUIDANCE
IS FAR FROM UNANIMOUS IN THE DEVELOPMENT OR WHERE IT MAY TRACK,
POSSIBLY PUSHING ACROSS THE FORECAST AREA LATER SATURDAY NIGHT INTO
SUNDAY. THEN, BEHIND THIS POTENTIAL MCS, THE NEXT MAJOR WAVE/FRONTAL
BOUNDARY AND CHANCE FOR ORGANIZED CONVECTION IS EXPECTED FOR SUNDAY
NIGHT INTO MONDAY. DRY WEATHER IS LIKELY BEHIND THIS SYSTEM TO
FINISH OUT THE FORECAST PERIOD.
NEAR NORMAL TEMPERATURES ARE EXPECTED THROUGH THE PERIOD, WITH HIGHS
IN THE 80S AND LOWS IN THE 60S. THERE WILL BE A GRADUAL INCREASE IN
HUMIDITY AHEAD OF THE SUNDAY NIGHT/MONDAY FRONT, WITH LESS HUMID
CONDITIONS LIKELY IN ITS WAKE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1243 PM CDT WED AUG 5 2015
MAIN CONCERN IN THE FORECAST WILL BE THE PRECIP IN THE SOUTH
ASSOCIATED WITH A QUASI STALLED BOUNDARY ACROSS THE SOUTHERN
PORTION OF THE STATE. THE MODELS HAVE CONSISTENTLY PUSHED THE
MAJORITY OF THE PRECIP TO THE SOUTH AND NOT IMPACTING THE ILX
TERMINALS WITH ANY PERSISTENCE. SO HAVE KEPT TO THE VC MENTION FOR
THE AFTERNOON/EVENING HOURS. SPI AND DEC MOST LIKELY TO SEE TS
ASSOCIATED WITH THE STORMS. THROUGH 06Z, HRRR IS DRY AND STILL A
LOT OF UNCERTAINTY ABOUT NORTHERLY EXTENT OF PRECIP BEFORE 12Z.
WITH THIS IN MIND, MODELS LOW LEVEL RH IS WAY OVERDONE WITHOUT
INCREASED MOISTURE FROM PRECIP. ALTHOUGH MODELS DROPPING CIGS TO
IFR...HAVE SPLIT THE DIFFERENCE AND ONLY DROPPING SOUTHERN
TERMINALS TO BORDERLINE MVFR UNTIL THE PRECIP ACTUALLY OCCURS,
INCREASING THE DEWPOINTS.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...HJS
LONG TERM...BAK
AVIATION...HJS
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1251 PM CDT WED AUG 5 2015
.UPDATE...
ISSUED AT 1056 AM CDT WED AUG 5 2015
FRONTAL BOUNDARY WELL TO THE SOUTH OF THE FA THIS MORNING WITH
MAINLY CIRRUS DOMINATING THE SKIES. MODELS CONSISTENTLY TRENDING
SOUTH SO HAVE PARED BACK ON THE POPS FOR THE REMAINDER OF THE DAY
AS FAR AS THE NORTHERLY EXTENT OF THE CHANCE POPS. CANNOT RULE OUT
SOME SCT ACTIVITY ON THE OUTFLOW OF THE CONVECTION TO THE SOUTH SO
WILL NOT REMOVE RAIN CHANCES ALTOGETHER AT THIS TIME.
&&
.SHORT TERM...(TODAY)
ISSUED AT 330 AM CDT WED AUG 5 2015
STATIONARY BOUNDARY IS WELL SOUTH OF THE AREA SO THE LOW PRESSURE
AREA THAT IS FORECAST TO RIDE ALONG THE FRONT TODAY SHOULD REMAIN
SOUTH OF THE AREA THROUGH TODAY...KEEPING PCPN LITTLE FURTHER SOUTH
AS WELL. SO...POPS/WX FOR TODAY HAVE BEEN ADJUSTED SOUTH SOME SO
THAT AREAS ALONG AND NORTH OF I-74 WILL ONLY HAVE A SLIGHT CHANCE OF
PCPN TODAY. THE HIGHEST CHANCE OF PCPN WILL BE IN THE SOUTHWEST THIS
MORNING AND THEN SHIFT TO THE SOUTH AND SOUTHEAST DURING THE
AFTERNOON. NOT REAL CLOUDY OVER THE AREA CURRENTLY...BUT AS THINGS
CONTINUE TO DEVELOP...CLOUDS WILL INCREASE TO MOSTLY CLOUDY OVER
MOST OF THE AREA. WINDS WILL BE QUITE LIGHT BUT BECOME LIGHT
EASTERLY DURING THE PERIOD. CLOUDS AND PCPN WILL KEEP TEMPS DOWN
TODAY AND SHOULD BE IN THE LOWER 80S. LOWER HIGHS SHOULD BE IN THE
SOUTH WHERE MORE PCPN AND THICKER CLOUDS WILL BE.
.LONG TERM...(TONIGHT THROUGH TUESDAY)
ISSUED AT 330 AM CDT WED AUG 5 2015
00Z MODELS HAVE CONTINUED TO TREND FURTHER SOUTH WITH SHORT WAVE
AND ASSOCIATED QPF TONIGHT INTO THU AND ALSO TRENDING QUICKER ENDING
THE CHANCES OF RAIN BY THU AFTERNOON. NAM AND ECMWF MODELS ARE STILL
FURTHER NORTH THAN THE FURTHEST SOUTH GFS MODEL AND STAYED CLOSER TO
NAM/ECMWF MODELS AND THEIR ENSEMBLES. NORTHERN CWA FROM PEORIA NORTH
NOW LOOK DRY WHILE SOUTHEAST IL TO HAVE HIGHEST POPS OF 60-80% WHILE
RAINFALL AMOUNTS HALF TO 1 INCH FROM I-70 SOUTH. THE HEAVIER RAINS
OF 1-2 INCHES NOW APPEARS TO BE SOUTH OF I-64 WHERE FLOOD POTENTIAL
WILL BE HIGHER TONIGHT INTO THU MORNING.
00Z FORECAST MODELS SHOW AN UPPER LEVEL RIDGE OF HIGH PRESSURE OVER
TEXAS LATE THIS WEEK WHILE UPPER LEVEL TROF OVER THE NORTHEAST U.S.
SO IL GETS ESTABLISH IN A NW UPPER LEVEL FLOW THIS WEEKEND INTO
EARLY NEXT WEEK WITH A COUPLE OF SHORT WAVES AND POSSIBLE MCS TO
AFFECT PARTS OF THE REGION AS THEY MOVE AROUND TOP OF UPPER LEVEL
RIDGE (RING OF FIRE). HAVE SLIGHT CHANCES OF CONVECTION WEST OF I-57
ON FRIDAY WHILE BETTER CHANCES IN SW IL INTO SE MO WHERE POSSIBLE
MCS INTO FRIDAY MORNING AND NORTH OF I-80 WHERE A STRONGER SHORT
WAVE TRACKS EAST INTO WI AND NORTHERN IL BY 00Z/SAT. ECMWF MODEL
KEEPS QPF NORTH AND NE OF CENTRAL IL FRI NIGHT AS DISTURBANCE TRACKS
EAST ACROSS MI WHILE GFS HAS QPF AS FAR SOUTH AS CENTRAL IL. ELECTED
TO KEEP A DRY FORECAST FRIDAY NIGHT AND SAT. HIGHS FRI IN THE LOW TO
MID 80S AND MID TO UPPER 80S SAT AND RATHER HUMID WITH DEWPOINTS
IN THE UPPER 60S AND LOWER 70S.
ANOTHER SHORT WAVE RIDGING ESE FROM IA INTO CENTRAL/NORTHERN IL SAT
NIGHT INTO TUE TO BRING A POSSIBLE MCS WITH CHANCES OF SHOWERS AND
THUNDERSTORMS. SIDED WITH WETTER ECMWF MODEL WHILE GFS MODEL IS
TOTALLY DRY OVER CWA SAT NIGHT AND JUST HAS LIGHT QPF PATCHES IN NW
CWA SUNDAY. HIGHS IN THE MID TO UPPER 80S SUNDAY AND DEWPOINTS IN
THE LOWER 70S. GFS AND ECMWF MODELS SHOW A COLD FRONT PUSHING
SOUTHWARD OVER CENTRAL IL DURING MONDAY KEEPING CHANCES OF
SHOWERS/THUNDERSTORMS AROUND. THEN DRIER CONDITIONS EXPECTED MONDAY
NIGHT THROUGH WED AS HIGH PRESSURE SETTLES INTO IA/MO BY TUE
NIGHT/WED. HIGHS IN THE 80S MONDAY THEN A BIT COOLER AND LESS HUMID
TUE/WED BEHIND THE FRONT.
DRY CONDITIONS WILL RETURN ON TUESDAY AS HIGH PRESSURE RE-
ESTABLISHES ITSELF OVER THE ROCKIES. TEMPS THROUGH THE PERIOD WILL
BE AT OR SLIGHTLY BELOW NORMAL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1243 PM CDT WED AUG 5 2015
MAIN CONCERN IN THE FORECAST WILL BE THE PRECIP IN THE SOUTH
ASSOCIATED WITH A QUASI STALLED BOUNDARY ACROSS THE SOUTHERN
PORTION OF THE STATE. THE MODELS HAVE CONSISTENTLY PUSHED THE
MAJORITY OF THE PRECIP TO THE SOUTH AND NOT IMPACTING THE ILX
TERMINALS WITH ANY PERSISTENCE. SO HAVE KEPT TO THE VC MENTION FOR
THE AFTERNOON/EVENING HOURS. SPI AND DEC MOST LIKELY TO SEE TS
ASSOCIATED WITH THE STORMS. THROUGH 06Z, HRRR IS DRY AND STILL A
LOT OF UNCERTAINTY ABOUT NORTHERLY EXTENT OF PRECIP BEFORE 12Z.
WITH THIS IN MIND, MODELS LOW LEVEL RH IS WAY OVERDONE WITHOUT
INCREASED MOISTURE FROM PRECIP. ALTHOUGH MODELS DROPPING CIGS TO
IFR...HAVE SPLIT THE DIFFERENCE AND ONLY DROPPING SOUTHERN
TERMINALS TO BORDERLINE MVFR UNTIL THE PRECIP ACTUALLY OCCURS,
INCREASING THE DEWPOINTS.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HJS
SHORT TERM...AUTEN
LONG TERM...07
AVIATION...HJS
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1109 PM CDT TUE AUG 4 2015
.UPDATE...
ISSUED AT 835 PM CDT TUE AUG 4 2015
FRONTAL BOUNDARY OVER FAR SOUTHERN ILLINOIS WILL CONTINUE TO BE
THE FOCUS FOR PERIODIC SHOWERS AND THUNDERSTORMS OVER THE NEXT
24 TO 36 HOURS WITH A GRADUAL SHIFT NORTHEAST INTO OUR FORECAST
AREA ON WEDNESDAY AS A WEAK SURFACE WAVE APPROACHES FROM THE
WEST. MOST OF THE SHORT TERM FORECAST SOLUTIONS FOR THE OVERNIGHT
HOURS KEEP THE BULK OF THE SHOWER ACTIVITY OVER SOUTHERN IL WITH
QUITE A BIT OF MID AND HIGH LEVEL CLOUD COVER EXPECTED TO ITS
NORTH OVER THE REMAINDER OF OUR FORECAST AREA. HIGHER POPS WILL
CONTINUE TO BE LOCATED OVER THE SOUTHERN AREAS WITH PROGRESSIVELY
LOWER POPS AS YOU HEAD NORTH. UPDATED ZONES SHOULD BE OUT BY 900
PM.
&&
.SHORT TERM...(TONIGHT)
ISSUED AT 303 PM CDT TUE AUG 4 2015
A STATIONARY FRONTAL BOUNDARY WILL LINGER ACROSS SOUTHERN IL
TONIGHT, WHERE BETTER CHANCES OF SHOWERS AND STORMS SHOULD START OUT
THE EVENING. NORTH OF THE BOUNDARY INTO OUR SOUTHERN COUNTIES, WEAK
ISENTROPIC LIFT AND MID LEVEL CONVERGENCE WILL WORK TO TRIGGER
SHOWERS AND A FEW STORMS TOWARD SPRINGFIELD TO MATTOON TONIGHT. THIS
AFTERNOON, SHOWERS/STORMS DEVELOPED WELL NORTH OF WHERE THE HRRR AND
RAP MODELS INDICATED, SO THE FACT THAT THEY CONTINUE TO SHOW DRY
CONDITIONS OVERNIGHT FOR OUR COUNTIES DOES NOT PRECLUDE THAT SHOWERS
REACH AS FAR NORTH AS LINCOLN TO MATTOON AGAIN OVERNIGHT. ONGOING
SHOWERS/STORMS LATE THIS AFTERNOON FROM SPRINGFIELD TO SHELBYVILLE
ARE EXPECTED TO DISSIPATE AS THEY PROGRESS EASTWARD. THEREFORE
WILL START OUT THE EVENING GRIDS WILL MAINLY SLIGHT CHANCE IN OUR
SOUTHERN COUNTIES, BUT MAY ADJUST POPS UP AS LATE AFTERNOON
CONDITIONS WARRANT. DESPITE THE DRY HIGH RESOLUTION MODELS
TONIGHT, THE CONSENSUS OF THE GFS, NAM, ECMWF AND CANADIAN
INDICATES ENOUGH FORCING FOR PRECIP REDEVELOPING ACROSS OUR
SOUTHERN COUNTIES. THEREFORE, HAVE NOT STRAYED FAR FROM THE
CURRENT FORECAST OF CHANCE POPS EXPANDING NORTH TO AREAS SOUTHWEST
OF A LINE FROM CANTON TO LINCOLN TO MATTOON.
LOW TEMPS TONIGHT WILL VARY BASED ON THE AMOUNT OF CLEARING THAT
DEVELOPS UNDER LIGHT ENE FLOW. AFTERNOON DEWPOINTS HAVE POINTED
TOWARD LOWS TONIGHT GENERALLY IN THE LOWER 60S NORTH OF I-74, WITH
UPPER 60S IN SOUTH OF I-70, WHERE CLOUDS MAY BE MORE PREVALENT LATER
TONIGHT.
.LONG TERM...(WEDNESDAY THROUGH TUESDAY)
ISSUED AT 303 PM CDT TUE AUG 4 2015
WEDNESDAY COULD START OUT WILL A LULL IN THE SHOWERS AS THE
ENERGY FROM THE OVERNIGHT CONVECTION SHIFTS EAST INTO INDIANA. THE
NEXT WAVE OF PRECIP LOOKS TO BE TIED TO THE ADVANCEMENT OF A LOW
PRESSURE SYSTEM FROM THE CENTRAL PLAINS ACROSS SOUTH CENTRAL IL.
THE 12Z MODELS HAVE CONTINUED WITH THE SOUTHWARD TREND OF TRACKING
THE LOW ACROSS IL WEDNESDAY NIGHT INTO THURSDAY. HOWEVER, THEY
ALSO CONTINUE TO PROJECT OVERRUNNING SHOWERS/STORMS DEVELOPING
AHEAD OF THE LOW WED AFTERNOON ACROSS OUR SOUTHERN COUNTIES.
WEDNESDAY NIGHT, PRECIP CHANCES ALONG AND SOUTH OF I-72 WILL RAMP
UP TO LIKELY, WITH CATEGORICAL POPS SOUTH OF I-70 AS THE LOW
PASSES JUST SOUTH OF STATE HWY 50. HEAVY PRECIP REMAINS POSSIBLE
WED NIGHT INTO THURSDAY MORNING SOUTH OF I-70, AS PRECIPITABLE
WATER VALUES CLIMB TO 1.8". WILL MONITOR FOR POSSIBLE FLASH FLOOD
WATCH, BUT DRY CONDITIONS RECENTLY MAY HELP PREVENT FLASH
FLOODING. ALSO, A DRIER TREND IN THE 12Z MODELS HAS LOWERED
CONFIDENCE IN VERY HEAVY RAINFALL IN OUR SOUTHERN COUNTIES.
THURSDAY SHOULD SEE DRY CONDITIONS RETURN BY AFTERNOON AS THE LOW
PULLS AWAY TO THE EAST AND HIGH PRESSURE GAINS CONTROL OF THE LOCAL
WEATHER. RIDGING ALOFT WILL REACH WESTERN IL, WITH HEIGHT RISES
HELPING HIGHS REACH THE LOW 80S.
LOW PRESSURE TRACKING FROM THE DAKOTAS THURSDAY AFTERNOON TO EASTERN
LAKE SUPERIOR SATURDAY MORNING COULD DRAG A WEAKENING COLD FRONT
INTO NORTHERN IL LATE FRIDAY INTO FRI EVENING. WE ONLY ACKNOWLEDGED
THAT FEATURE WITH SLIGHT CHANCE POPS WEST OF I-55 FOR NOW.
THERE ARE INDICATIONS IN THE EXTENDED MODELS THAT AN MCS COULD
DEVELOP IN NEBRASKA ON SATURDAY, THEN PROGRESS EASTWARD INTO CENTRAL
IL SAT NIGHT-SUNDAY. THE CANADIAN IS THE NORTHERN OUTLIER WITH THE
TRACK OF THE SYSTEM, KEEPING IT GENERALLY NORTH OF OUR COUNTIES,
WHILE THE GFS/ECMWF BOTH PUSH THE WAVE INTO CENTRAL IL. WILL KEEP
CHANCE POPS FOR THE ENTIRE FORECAST AREA SUNDAY INTO SUNDAY NIGHT,
WITH DECREASING CHANCES FROM WEST TO EAST ON MONDAY. DRY
CONDITIONS ARE EXPECTED FOR TUESDAY AS AN UPPER TROUGH BUILDS INTO
THE AREA.
HEAT AND HUMIDITY ARE PROJECTED TO INCREASE SATURDAY AND CONTINUE
INTO MONDAY, WITH HIGHS IN THE MID 80S AND HEAT INDICES IN THE LOWER
90S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1102 PM CDT TUE AUG 4 2015
FORECAST CONCERN WILL BE COVERAGE OF SHOWERS AND THUNDERSTORMS
LATE TONIGHT INTO WEDNESDAY AND THEIR AFFECT ON CIGS...ESPECIALLY
AT KSPI AND KDEC...AS A WEATHER SYSTEM DRIFTS ACROSS SOUTHERN
ILLINOIS. WIDELY SCATTERED SHOWERS AND STORMS WERE NOTED OVER
PARTS OF CENTRAL MISSOURI LATE THIS EVENING AND THOSE ARE EXPECTED
TO DRIFT EAST TOWARDS THE MISSISSIPPI RIVER OVER THE NEXT SEVERAL
HOURS. THE AIR MASS IN OUR AREA LATE THIS EVENING WAS QUITE STABLE
SO IT APPEARS AT LEAST THE INTENSITY WILL WEAKEN AS THEY DRIFT
EAST BUT CONFIDENCE ON COVERAGE OF THE RAIN OVER WESTERN IL LATE
TONIGHT IS NOT VERY HIGH AS MODELS CONTINUE TO SUGGEST A DECREASE
IN COVERAGE AS THEY MOVE INTO THE MORE STABLE ENVIRONMENT. AS A
RESULT...UNLESS WE SEE AN INCREASE IN COVERAGE TO OUR WEST OVER
THE NEXT HOUR OR SO...WILL ONLY INCLUDE A VCTS AT KSPI IN THE 06Z
TO 09Z TIME FRAME.
AS THE WEAK SURFACE WAVE MOVES ALONG THE STALLED FRONTAL BOUNDARY
TO OUR SOUTH ON WEDNESDAY...THE HIGHER THREAT FOR SHOWERS AND
STORMS WILL BE ROUGHLY FROM SPRINGFIELD TO DECATUR AND SOUTH.
STILL THINKING MAINLY SOME SCATTERED TO BKN MID CLOUDS WITH SOME
HIGHER OVERCAST FURTHER NORTH...WITH LOWER VFR CIGS AT KSPI AND
KDEC. SURFACE WINDS WILL REMAIN LIGHT AND VARIABLE OVERNIGHT AND
BECOME LIGHT EASTERLY ON WEDNESDAY WITH SPEEDS OF 10 KTS OR LESS.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SMITH
SHORT TERM...SHIMON
LONG TERM...SHIMON
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1046 PM CDT THU AUG 6 2015
.UPDATE...
ISSUED AT 1045 PM CDT THU AUG 6 2015
UPPER LEVEL TROUGH PUSHING INTO MN HAS TRIGGERED AN AREA OF
SHOWERS AND SCATTERED THUNDERSTORMS OVER MN...NW WI AND FAR NW IA.
THIS PRECIPITATION WAS GRADUALLY SPREADING SOUTHEAST BUT THE
STRONGER FORCING WILL REMAIN NORTH OF THE DVN CWA OVERNIGHT.
HOWEVER...THE NORTHERN CWA DOES GET GRAZED BY WEAK FORCING WELL
AFTER MIDNIGHT AND INTO FRIDAY MORNING. THE HRRR HAS BEEN
CONSISTENT IN SPREADING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS
ACROSS THE CWA AND I WILL MAINTAIN THE 30-50 POPS. THE FORCING
SHIFTS OFF TO OUR NORTHEAST ON FRIDAY SO MUCH OF THE AFTERNOON
APPEARS DRY. HOWEVER...SOUTHERLY WINDS WILL PULL WARM AND HUMID
AIR INTO THE CWA WITH DEWPOINTS OF 70+ IN THE AFTERNOON...MAINLY
WEST OF THE MS RIVER.
&&
.SYNOPSIS...
ISSUED AT 257 PM CDT THU AUG 6 2015
12Z UA ANALYSIS HAD AN 850MB HIGH OVER THE NORTHERN GREAT LAKES WITH
VERY DRY AIR THROUGH WISCONSIN...IOWA...AND BACK INTO THE RED RIVER
VALLEY OF THE NORTH. A WEAK 850MB LOW WAS OVER EXTREME EASTERN
MONTANA AND PLENTY OF MOISTURE WAS ACROSS THE CENTRAL AND SOUTHERN
PLAINS. SATELLITE/RADAR TRENDS THROUGH MID-AFTERNOON SHOW SHOWERS
DISSIPATING OVER WESTERN IOWA WITH SOME LOW AND MOSTLY HIGH LEVEL
CLOUDS ACROSS THE WESTERN GREAT LAKES.
18Z SFC DATA HAS HIGH PRESSURE OVER THE GREAT LAKES WITH WEAK LOWS
OVER THE DAKOTAS AND LOWER OHIO VALLEYS. DEW POINTS WERE IN THE 50S
ACROSS THE GREAT LAKES WITH 60S AND POCKETS OF 70 DEW POINTS FROM
THE PLAINS INTO THE OHIO VALLEY.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 257 PM CDT THU AUG 6 2015
QUIET AND DRY CONDITIONS WILL BE SEEN THROUGH THROUGH SUNSET AND THE
EVENING HOURS AS THE HIGH SLOWLY MOVES INTO THE EASTERN GREAT LAKES.
AS MOISTURE RETURNS ACROSS WESTERN IOWA AND FORCING INCREASES THIS
EVENING. A WING OF WARM ADVECTION PRECIPITATION WILL DEVELOP THAT
SLOWLY MOVES EAST OVERNIGHT. THE FORCING IS NOT GREAT AND THERE IS
PLENTY OF DRY AIR THAT MUST BE OVERCOME. HOWEVER...SHOWERS AND A FEW
THUNDERSTORMS WILL BE POSSIBLE WEST OF A LINE FROM KDBQ TO KIRK BY
SUNRISE FRIDAY.
ON FRIDAY...THE WING OF WARM ADVECTION PRECIPITATION WILL MOVE
ACROSS THE AREA DURING THE MORNING AND SLOWLY DECAY AS THE FORCING
WEAKENS. THE BETTER CHANCES FOR ANY RAIN WOULD BE MAINLY NORTH OF I-
80. COVERAGE WOULD BE THE BEST DURING THE MORNING AND SHOULD BE
SCATTERED AT BEST.
THE QUESTION FRIDAY AFTERNOON IS WHETHER OR NOT THE DECAYING
PRECIPITATION WILL CONTINUE. THE LACK OF FORCING SUGGESTS DRY
CONDITIONS FOR THE AFTERNOON HOURS. HOWEVER...THERE IS A SUBTLE
FRONT/BOUNDARY THAT WILL MOVE THROUGH THE AREA WHICH MIGHT PROVIDE
JUST ENOUGH CONVERGENCE TO ALLOW ISOLATED SHOWERS AND POSSIBLY A
THUNDERSTORM TO PERSIST DURING THE AFTERNOON.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 257 PM CDT THU AUG 6 2015
THE LONG TERM PORTION OF THE FORECAST WILL FOCUS ON ONE PERIOD OF
SYNOPTICALLY SUPPORTED RAIN CHANCES TOWARD SATURDAY NIGHT AND
SUNDAY...FOLLOWED BY A HIGH CONFIDENCE PERIOD OF DRY WEATHER FOR
MONDAY NIGHT THROUGH WEDNESDAY.
SATURDAY NIGHT SHOULD SEE A LOW LEVEL JET WITH RICH MOISTURE AIMED
AT IOWA...WITH A PROGRESSIVE SHORT WAVE ALOFT MOVING THROUGH IN
ZONAL FLOW. THIS SUPPORTS A CONVECTIVE COMPLEX IN THE REGION.
HOWEVER...MODELS ARE HIGHLY VARIABLE ON BOUNDARY LOCATIONS SATURDAY
THROUGH SUNDAY...AND UNTIL THERE IS CONFIDENCE ON BOUNDARY
LOCATION...THE MCS TRACK SHOULD BE RATHER LOW CONFIDENCE. THE SIGNAL
FOR RAINS IS HIGHEST IN THE SOUTHWEST 1/2 OF THE CWA...BUT WE WILL
CONFINE POPS TO THE 40 TO 65 PERCENT RANGE FROM THE MODEL BLEND IN
ANY CASE. THIS PATTERN REPRESENTS POTENTIAL FOR RAINS OF 0.25 TO 1
INCH...BUT THIS MAY NOT BE A DIRECT HIT...AND THERE REMAINS SOME
THREAT FOR THE ENTIRE EVENT TO SLIP SOUTH OR ONLY BRUSH OUR SOUTHERN
AREAS. TO MAKE THINGS INTERESTING...OTHER MODELS SUCH AS THE GEM
SUGGEST STRONGER CAPPING...WITH THE EVENT MAINLY IN THE NORTHERN CWA
AND POINTS NORTH...SO AS SAID...AN MCS IS LIKELY...BUT LOCATIONS
IMPACTED ARE NOT OVERLY CONFIDENT.
TEMPERATURES WILL BE LARGELY CONSISTENT THROUGHOUT THE ENTIRE
FORECAST PERIOD...WITH UPPER 70S TO LOWER 80S ON NEARLY EVERY DAY.
THE WEEKEND WILL BE MODESTLY HUMID WITH DEWPOINTS IN THE MID 60S TO
MID 70S...BUT WITH A HIGH AMPLITUDE PATTERN SETTING UP BEYOND
MONDAY...ANOTHER WEEK OF GREAT LAKES / CANADIAN AIR IS NEARLY
GUARANTEED. THIS COOLER THAN NORMAL PATTERN CARRIES US TO MID
AUGUST...AND WITH LOWER SUN ANGLE HEADING OUR WAY SOON...OUR CHANCES
FOR EXCEEDING 90 AGAIN THIS SUMMER ARE GOING DOWN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1045 PM CDT THU AUG 6 2015
VFR CONDITIONS WILL BE SEEN THROUGH 08Z/07 AS HIGH PRESSURE MOVES
INTO THE EASTERN GREAT LAKES. AFTERWARDS AN UPPER LEVEL
DISTURBANCE WILL BRING THE POTENTIAL FOR SCATTERED SHRA/ISOLD TSRA
TO EASTERN IOWA AND NORTHERN ILLINOIS LATE TONIGHT INTO FRIDAY
MORNING. HOWEVER...CONFIDENCE IS LOW ON THE COVERAGE OF PCPN SO
HAVE MAINTAINED A VCSH AT KCID/KDBQ/KMLI FOR NOW. SOUTHEAST TO
SOUTH WINDS LESS THAN 10 KNOTS THROUGH THE PERIOD.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...HAASE
SYNOPSIS...08
SHORT TERM...08
LONG TERM...ERVIN
AVIATION...HAASE
AREA FORECAST DISCUSSION
NWS GOODLAND KS
251 PM MDT WED AUG 5 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 238 PM MDT WED AUG 5 2015
FORECAST CONCERNS WILL BE LOW CHANCE OF THUNDERSTORMS IN THE
NORTHWEST CORNER THROUGH THE MIDDLE OF THE NIGHT...THE EXTENT OF THE
FOG LATER TONIGHT INTO TOMORROW MORNING...AND ANOTHER CHANCE OF
THUNDERSTORMS ON THURSDAY. SATELLITE SHOWING
MODELS INITIALLY WELL AT MID AND UPPER LEVELS. THE SREF WAS DOING
A LITTLE BETTER THAN THE GFS AND RAP ON THE SURFACE WIND AND
PRESSURE FIELD. THE GFS AND CANADIAN WERE DOING A LITTLE BETTER
THAN THE SREF AND NAM ON THE LOW LEVEL THERMAL FIELD.
TONIGHT...A SURFACE BOUNDARY HAS SET UP ALONG THE WESTERN END OF
THE AREA WITH SOME CUMULUS DEVELOPMENT. THAT DEVELOPMENT SHOULD
CONTINUE WITH LITTLE TO NO CAP. HOWEVER...THERE IS MUCH AT MID TO
UPPER LEVELS UNTIL THE MID EVENING INTO THE OVERNIGHT. A SHORTWAVE
TROUGH STARTS MOVING THROUGH IN THE LATER HALF OF THE NIGHT AND THERE
ALSO LOOKS TO BE SOME WEAK JET LIFT AFFECTING THE NORTHWEST
CORNER THROUGH THE MIDDLE OF TONIGHT.
INITIALLY THE NAM IS THE MOST AGGRESSIVE IN PRODUCING
THUNDERSTORMS LATER THIS AFTERNOON INTO THE OVERNIGHT HOURS. NOW
THE RAP AND HRRR ARE SUPPORTING SOME ISOLATED DEVELOPMENT IN THE
AREA OF CONVERGENCE THAT IS GOING ON RIGHT NOW. THIS AREA THEN
SHIFTS TO THE NORTH AND EAST THROUGH THE NIGHT. LIFT AND WARM AIR
ADVECTION ALOFT INCREASE A GREAT DEAL IN THE EASTERN PORTION OF
THE AREA DURING THE LAST HALF OF THE NIGHT. MODELS WOULD INDICATE
A STRONG CAP ALOFT BUT MORE THAN ONE PIECE OF GUIDANCE IS
INDICATING SOME LIGHT QPF. AM A LITTLE CONCERNED ABOUT THIS
ACTIVITY. IF THE LIFT BREAKS THE CAP...THE INSTABILITY AND PWS ARE
RATHER IMPRESSIVE. WOULD NOT BE SURPRISED TO HAVE SOME STRONG
STORMS WITH SOME HEAVY RAINFALL.
THURSDAY...THE NAM AND OTHER HIGH RESOLUTION GUIDANCE DEVELOPS
PRECIPITATION OVER THE CENTRAL AND EASTERN PORTION OF THE AREA
EARLY IN THE DAY. THIS MATCHES WELL WITH THE INSTABILITY AND
SHORTWAVE TROUGH MOVING THROUGH SO WILL CONTINUE THE SLIGHT CHANCE
POPS THROUGH THE MORNING. WILL BE POTENTIAL FOR STRONG STORMS AND
HEAVY RAINFALL.
SOME FOG AND ESPECIALLY STRATUS WILL BE AROUND THROUGH
THE MORNING. THIS WILL BE IN ADVANCE OF A BOUNDARY MOVING THROUGH.
MODELS BRING THIS BOUNDARY THROUGH DURING THE LATE MORNING AND
AFTERNOON. MOST OF THE MODEL OUTPUT WOULD INDICATE THAT NOT MUCH
COOLING WILL OCCUR WITH THIS SURFACE TROUGH/WEAK FRONT. THIS DOES
MAKE SENSE CONSIDERING THE WESTERLY FLOW ALOFT AND STRONG RIDGE TO
OUR SOUTH.
SO THE HIGH TEMPERATURE FORECAST WILL BE A LITTLE TRICKY DUE TO
THE VARIABLE NATURE OF THE CLOUD COVER...SOME PRECIPITATION
POSSIBLE...AND THE BOUNDARY TIMING. SO WENT COOLER IN THE EAST
WHERE THE CLOUD COVER LASTS LONGER AND THE 850 MB TEMPERATURES ARE
THE COOLEST. HOTTER TEMPERATURES WILL BE IN THE SOUTH AND WEST IT
DOES APPEAR.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 116 PM MDT WED AUG 5 2015
RIDGE AXIS BUILDS OVER THE HIGH PLAINS THURSDAY NIGHT RESULTING IN
DRY CONDITIONS. NEXT SHORTWAVE TROUGH WILL TOP THE RIDGE FRIDAY
AFTERNOON AND EVENING BRINGING A GOOD CHANCE FOR THUNDERSTORMS.
WHILE SHEAR/INSTABILITY PARAMETERS ARE NOT OVERWHELMING...THEY ARE
PROBABLY SUFFICIENT FOR ANOTHER ROUND OF SEVERE WEATHER WITH LARGE
HAIL AND DAMAGING WINDS THE MAIN THREATS. NAM PRECIPITABLE WATER
VALUES INCREASE TO 1-1.5 INCHES BY 00Z/SAT AND STORM MOTIONS WILL
BE NORTHEAST AT AROUND 20KTS...NEITHER PARAMETER REALLY SUGGESTING
WIDESPREAD HEAVY RAINFALL THOUGH THERE WILL CERTAINLY BE SOME
LOCAL DELUGES...ESPECIALLY NEAR RIGHT MOVING SUPERCELLS WHERE
STORM MOTIONS WILL BE MUCH SLOWER.
THE PATTERN DOESNT CHANGE MUCH ON SATURDAY WITH A BROAD
SOUTHWESTERLY FLOW ALOFT AND EMBEDDED WEAK SHORTWAVE TROUGH
BRINGING ANOTHER CHANCE FOR SHOWERS AND THUNDERSTORMS...SOME
SEVERE WITH SUFFICIENT SHEAR/INSTABILITY FORECAST ONCE AGAIN.
WILD CARD WILL BE LOCATION OF SURFACE BOUNDARIES WHICH MAY BE
INFLUENCED BY PREVIOUS DAYS CONVECTION AND WILL BE HARD TO PIN
DOWN AT THIS TIME...BUT MAY PROVE TO BE PIVOTAL FOR CONVECTIVE
INITIATION.
SUNDAY THROUGH WEDNESDAY THE RIDGE IS FORECAST TO BUILD SHARPLY
NORTHWARD WITH THE RIDGE AXIS BY WEDNESDAY CENTERED OVER THE HIGH
PLAINS FROM CANADA TO THE TEXAS PANHANDLE. FOR THIS REASON AM
SOMEWHAT SKEPTICAL OF PRECIPITATION CHANCES IN THE GLOBAL MODELS
AND THE DERIVED BLENDS USED TO INITIATE THE EXTENDED THE PERIODS.
NONETHELESS...SURFACE PROGS SHOW A CONSISTENT MOIST SOUTHEASTERLY
FLOW INTO THE REGION WITH RESULTANT INSTABILITY EACH DAY. SO THE
ATMOSPHERE WILL BE PRIMED FOR LIFT AND ANY MINOR DISTURBANCE WHICH
MAY MAKES ITS WAY THROUGH THE RIDGE MAY BE ENOUGH FOR CONVECTION
TO DEVELOP. HOWEVER DEEP LAYER SHEAR WILL BE RATHER LOW UNDER THE
RIDGE SO SEVERE THREAT SHOULD BE LIMITED.
TEMPERATURES WILL BE NEAR NORMAL THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1142 AM MDT WED AUG 5 2015
VFR CONDITIONS ARE EXPECTED UNTIL LATER TONIGHT. THERE WILL BE
SOME ISOLATED THUNDERSTORMS POSSIBLE TONIGHT. HOWEVER...THEY LOOK
TO BE TO THE NORTH AND WEST OF BOTH SITES SO I LEFT ANY MENTION OF
THUNDERSTORMS. HOWEVER THIS WILL TO BE WATCHED CLOSELY. BETWEEN
06Z AND 09Z...SOUTH TO SOUTHEAST WINDS WILL BRING AN INCREASE OF
LOW LEVEL MOISTURE TO THE AREA.
AT THE VERY LEAST...IT WILL BRING LOW CLOUDS ACROSS THE AREA AND
MAYBE SOME FOG. SO AT THIS TIME INSERTED MVFR CEILINGS AT BOTH
SITES. DID INTRODUCE FOG AT BOTH SITES WITH KMCK HAVING THE LOWER
VISIBILITY. SOME INDICATION THAT THE VISIBILITY COULD BE LOWER...
ESPECIALLY AT KMCK AND THIS WILL TO BE ADDRESSED IN LATER TAF
ISSUANCES.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...024
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS WICHITA KS
1256 PM CDT WED AUG 5 2015
...UPDATED FOR 18Z AVIATION DISCUSSION...
.UPDATE...
ISSUED AT 1010 AM CDT WED AUG 5 2015
SHOWERS & A FEW THUNDERSTORMS CONTINUE TO PUSH SE THIS MORNING. AS
OF 10 AM...MOST RAINFALL WAS OCCURRING OVER SOUTHEAST KS WITH A
CELL THAT DEVELOPED OVER EASTERN BUTLER COUNTY. WITH THE MODEST
CONVECTION CONTINUING TO PUSH ASSOCIATED OUTFLOW BOUNDARY FURTHER
S ACROSS EASTERN OK...AIRMASS ACROSS SOUTH-CENTRAL & SOUTHEAST KS
CONTINUES TO STABILIZE. AS SUCH CHANCES FOR ADDITIONAL RAIN WOULD
CONTINUE TO DIMINISH THIS AFTERNOON. INHERITED FORECAST DEPICTED
THIS SCENARIO. ALL PUBLIC PRODUCTS...INCLUDING THE HAZARDOUS
WEATHER OUTLOOK...HAVE BEEN UPDATED.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 307 AM CDT WED AUG 5 2015
THIS MORNING:
ANTICIPATING SCATTERED TO AT TIMES NUMEROUS SHOWERS/THUNDERSTORMS
EARLY THIS MORNING THROUGH THIS MORNING...MAINLY NORTHEAST OF A
LINE EXTENDING FROM GREAT BEND- WICHITA-ARKANSAS CITY...GRADUALLY
EXITING TO THE SOUTHEAST LATE MORNING/EARLY AFTERNOON. THIS
ACTIVITY IS IN RESPONSE TO MODEST/STRONG 850-700MB WARM/MOIST
ADVECTION AHEAD OF SHORTWAVE ENERGY APPROACHING FROM THE
NORTHWEST. WHILE WIDESPREAD SEVERE WEATHER IS NOT EXPECTED...AMPLE
ELEVATED INSTABILITY AND DEEP LAYER SHEAR COMBO (INCLUDING DECENT
0-3KM SHEAR FOR AN ORGANIZED WIND THREAT) SHOULD SUPPORT A HANDFUL
OF STRONG/SEVERE STORMS...CAPABLE OF MARGINALLY SEVERE LARGE HAIL
AND DAMAGING WINDS...ALONG WITH THE POTENTIAL FOR AREAS OF HEAVY
RAINFALL AND LOCALIZED FLOODING. IN FACT...POCKETS OF VERY HEAVY
RAINFALL RATES EXCEEDING 1-2 INCHES PER HOUR COULD PRODUCE
ISOLATED INSTANCES OF FLASH FLOODING.
THIS AFTERNOON-EVENING:
THUNDERSTORM CHANCES LATER THIS AFTERNOON-EVENING OVER SOUTHEAST
KS WILL BE DEPENDENT ON HOW FAR SOUTH THIS MORNING`S CONVECTIVE
OUTFLOW PUSHES. IF CONVECTIVE OUTFLOW PUSHES WELL SOUTH INTO
OK...AS ADVERTISED BY THE NAM...THEN ADDITIONAL PM STORM CHANCES
WILL LIKELY BE MINIMAL. HOWEVER...THE LESS BULLISH RAP WOULD
SUGGEST AT LEAST AN ISOLATED STRONG/SEVERE STORM CHANCE OVER
SOUTHEAST KS LATER THIS AFTERNOON-EVENING...AS IT KEEPS THE
EFFECTIVE FRONTAL ZONE A BIT FURTHER NORTH OVER SOUTHEAST KS. ALL-
IN-ALL THOUGH...BRUNT OF LATE AFTERNOON-EVENING CONVECTION SHOULD
REMAIN SOUTHEAST OF THE FORECAST AREA.
THURSDAY-FRIDAY:
A WARMING TREND IS EXPECTED FOR THURSDAY-FRIDAY...AS THE
SOUTHWEST CONUS UPPER RIDGE BUILDS/MOVES EAST ACROSS THE SOUTHERN
AND CENTRAL PLAINS. HIGH TEMPERATURES SHOULD PUSH THE CENTURY MARK
BOTH DAYS...ESPECIALLY CLOSER TO THE OK BORDER OVER SOUTH-CENTRAL
KS...WITH HEAT INDICES APPROACHING 105 DEGREES. SLIGHT TO MODEST
THUNDERSTORM CHANCES EXIST BOTH DAYS...ESPECIALLY THE NORTHEAST
HALF OF KS THURSDAY EVENING-NIGHT...AND THE NORTHERN HALF OF KS
FRIDAY EVENING-NIGHT.
ADK
.LONG TERM...(SATURDAY THROUGH TUESDAY)
ISSUED AT 307 AM CDT WED AUG 5 2015
SATURDAY-TUESDAY:
CONTINUED HOT SUMMER WEATHER SHOULD CONTINUE FOR SATURDAY-
SUNDAY...AS THE UPPER HIGH REMAINS ENTRENCHED ACROSS THE SOUTHERN
CONUS...AND A FRONTAL BOUNDARY REMAINS JUST NORTH OF THE FORECAST
AREA. DEWPOINT MAY BE TEMPERED SOME...ALTHOUGH HEAT INDICES IN THE
100-105 DEGREE RANGE (IF NOT HIGHER OVER SOUTHERN/SOUTHEAST KS)
REMAIN PLAUSIBLE. ANY THUNDERSTORM CHANCES SATURDAY-SUNDAY WILL
LIKELY BE LIMITED TO THE NORTHERN HALF OF KS AND NE DURING THE
EVENING-OVERNIGHT HOURS. SOMEWHAT COOLER WEATHER TO NEAR SEASONAL
NORMALS ALONG WITH STORM CHANCES SPREADING SOUTH IS SUPPORTED BY
THE MEDIUM RANGE CONSENSUS FOR MONDAY-TUESDAY...AS A SHORTWAVE
DROPS SOUTHEAST ACROSS THE GREAT LAKES/OHIO RIVER VALLEY...DRIVING
A COLD FRONT SOUTH. FOR NOW ONLY WENT WITH SLIGHT CHANCES POPS
SUNDAY EVENING-MONDAY.
ADK
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1256 PM CDT WED AUG 5 2015
CIGS FROM 1000-2500FT ARE NO DOUBT THE CONCERN FOR THIS AFTERNOON
& THIS EVENING. KICT IS ON THE SW PERIMETER OF THE STRATOCU DECK &
PER SATELLITE IMAGERY SHOULD DO SO THE REST OF THE AFTN. SKIES
SHOULD S-L-O-W-L-Y CLEAR IN A NW-SE MANNER AS WEAK LOW PRESSURE
GLIDES E ACRS CNTRL MO LATE THIS AFTN & EARLY THIS EVE. ANTICIPATE
ALL TERMINALS TO ACHIEVE VFR STATUS LATE THIS AFTN.
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 89 70 94 73 / 80 10 0 10
HUTCHINSON 87 68 94 71 / 70 10 0 10
NEWTON 84 69 91 71 / 80 10 10 10
ELDORADO 85 70 91 72 / 80 10 10 10
WINFIELD-KWLD 91 71 94 74 / 80 10 0 10
RUSSELL 86 66 94 69 / 50 0 10 10
GREAT BEND 88 67 95 70 / 30 0 10 10
SALINA 84 67 92 71 / 40 10 10 20
MCPHERSON 84 67 93 71 / 80 10 10 10
COFFEYVILLE 88 71 92 75 / 100 50 10 30
CHANUTE 85 70 90 72 / 90 40 10 30
IOLA 84 70 89 72 / 90 30 10 30
PARSONS-KPPF 86 71 91 74 / 100 40 10 30
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
1032 AM CDT WED AUG 5 2015
.UPDATE...
ISSUED AT 1010 AM CDT WED AUG 5 2015
SHOWERS & A FEW THUNDERSTORMS CONTINUE TO PUSH SE THIS MORNING. AS
OF 10 AM...MOST RAINFALL WAS OCCURRING OVER SOUTHEAST KS WITH A
CELL THAT DEVELOPED OVER EASTERN BUTLER COUNTY. WITH THE MODEST
CONVECTION CONTINUING TO PUSH ASSOCIATED OUTFLOW BOUNDARY FURTHER
S ACROSS EASTERN OK...AIRMASS ACROSS SOUTH-CENTRAL & SOUTHEAST KS
CONTINUES TO STABILIZE. AS SUCH CHANCES FOR ADDITIONAL RAIN WOULD
CONTINUE TO DIMINISH THIS AFTERNOON. INHERITED FORECAST DEPICTED
THIS SCENARIO. ALL PUBLIC PRODUCTS...INCLUDING THE HAZARDOUS
WEATHER OUTLOOK...HAVE BEEN UPDATED.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 307 AM CDT WED AUG 5 2015
THIS MORNING:
ANTICIPATING SCATTERED TO AT TIMES NUMEROUS SHOWERS/THUNDERSTORMS
EARLY THIS MORNING THROUGH THIS MORNING...MAINLY NORTHEAST OF A
LINE EXTENDING FROM GREAT BEND- WICHITA-ARKANSAS CITY...GRADUALLY
EXITING TO THE SOUTHEAST LATE MORNING/EARLY AFTERNOON. THIS
ACTIVITY IS IN RESPONSE TO MODEST/STRONG 850-700MB WARM/MOIST
ADVECTION AHEAD OF SHORTWAVE ENERGY APPROACHING FROM THE
NORTHWEST. WHILE WIDESPREAD SEVERE WEATHER IS NOT EXPECTED...AMPLE
ELEVATED INSTABILITY AND DEEP LAYER SHEAR COMBO (INCLUDING DECENT
0-3KM SHEAR FOR AN ORGANIZED WIND THREAT) SHOULD SUPPORT A HANDFUL
OF STRONG/SEVERE STORMS...CAPABLE OF MARGINALLY SEVERE LARGE HAIL
AND DAMAGING WINDS...ALONG WITH THE POTENTIAL FOR AREAS OF HEAVY
RAINFALL AND LOCALIZED FLOODING. IN FACT...POCKETS OF VERY HEAVY
RAINFALL RATES EXCEEDING 1-2 INCHES PER HOUR COULD PRODUCE
ISOLATED INSTANCES OF FLASH FLOODING.
THIS AFTERNOON-EVENING:
THUNDERSTORM CHANCES LATER THIS AFTERNOON-EVENING OVER SOUTHEAST
KS WILL BE DEPENDENT ON HOW FAR SOUTH THIS MORNING`S CONVECTIVE
OUTFLOW PUSHES. IF CONVECTIVE OUTFLOW PUSHES WELL SOUTH INTO
OK...AS ADVERTISED BY THE NAM...THEN ADDITIONAL PM STORM CHANCES
WILL LIKELY BE MINIMAL. HOWEVER...THE LESS BULLISH RAP WOULD
SUGGEST AT LEAST AN ISOLATED STRONG/SEVERE STORM CHANCE OVER
SOUTHEAST KS LATER THIS AFTERNOON-EVENING...AS IT KEEPS THE
EFFECTIVE FRONTAL ZONE A BIT FURTHER NORTH OVER SOUTHEAST KS. ALL-
IN-ALL THOUGH...BRUNT OF LATE AFTERNOON-EVENING CONVECTION SHOULD
REMAIN SOUTHEAST OF THE FORECAST AREA.
THURSDAY-FRIDAY:
A WARMING TREND IS EXPECTED FOR THURSDAY-FRIDAY...AS THE
SOUTHWEST CONUS UPPER RIDGE BUILDS/MOVES EAST ACROSS THE SOUTHERN
AND CENTRAL PLAINS. HIGH TEMPERATURES SHOULD PUSH THE CENTURY MARK
BOTH DAYS...ESPECIALLY CLOSER TO THE OK BORDER OVER SOUTH-CENTRAL
KS...WITH HEAT INDICES APPROACHING 105 DEGREES. SLIGHT TO MODEST
THUNDERSTORM CHANCES EXIST BOTH DAYS...ESPECIALLY THE NORTHEAST
HALF OF KS THURSDAY EVENING-NIGHT...AND THE NORTHERN HALF OF KS
FRIDAY EVENING-NIGHT.
ADK
.LONG TERM...(SATURDAY THROUGH TUESDAY)
ISSUED AT 307 AM CDT WED AUG 5 2015
SATURDAY-TUESDAY:
CONTINUED HOT SUMMER WEATHER SHOULD CONTINUE FOR SATURDAY-
SUNDAY...AS THE UPPER HIGH REMAINS ENTRENCHED ACROSS THE SOUTHERN
CONUS...AND A FRONTAL BOUNDARY REMAINS JUST NORTH OF THE FORECAST
AREA. DEWPOINT MAY BE TEMPERED SOME...ALTHOUGH HEAT INDICES IN THE
100-105 DEGREE RANGE (IF NOT HIGHER OVER SOUTHERN/SOUTHEAST KS)
REMAIN PLAUSIBLE. ANY THUNDERSTORM CHANCES SATURDAY-SUNDAY WILL
LIKELY BE LIMITED TO THE NORTHERN HALF OF KS AND NE DURING THE
EVENING-OVERNIGHT HOURS. SOMEWHAT COOLER WEATHER TO NEAR SEASONAL
NORMALS ALONG WITH STORM CHANCES SPREADING SOUTH IS SUPPORTED BY
THE MEDIUM RANGE CONSENSUS FOR MONDAY-TUESDAY...AS A SHORTWAVE
DROPS SOUTHEAST ACROSS THE GREAT LAKES/OHIO RIVER VALLEY...DRIVING
A COLD FRONT SOUTH. FOR NOW ONLY WENT WITH SLIGHT CHANCES POPS
SUNDAY EVENING-MONDAY.
ADK
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 637 AM CDT WED AUG 5 2015
FOR ICT-HUT-SLN-RSL-CNU...WIDESPREAD SHOWERS/THUNDERSTORMS WILL
GRADUALLY EXIT THE REGION TO THE SOUTHEAST THIS MORNING. AREAS OF
VERY HEAVY RAIN...GUSTY WINDS AND FREQUENT LIGHTNING ARE LIKELY.
MVFR CIGS COULD LINGER INTO AT LEAST EARLY AFTERNOON...DUE TO
MOIST LOW-LEVELS AND COOL ADVECTION FROM THE NORTH.
ADK
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 89 71 96 73 / 80 10 10 10
HUTCHINSON 87 70 95 71 / 70 10 10 10
NEWTON 84 69 93 71 / 80 10 10 20
ELDORADO 85 70 93 72 / 80 20 10 20
WINFIELD-KWLD 91 72 96 74 / 80 20 10 10
RUSSELL 86 68 95 69 / 50 0 10 20
GREAT BEND 88 69 96 70 / 30 0 10 10
SALINA 84 70 94 71 / 40 10 10 20
MCPHERSON 84 69 95 71 / 80 10 10 20
COFFEYVILLE 88 71 94 75 / 100 40 10 20
CHANUTE 85 70 92 72 / 90 40 10 30
IOLA 84 70 91 72 / 90 40 10 30
PARSONS-KPPF 86 71 93 74 / 100 40 10 20
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
640 AM CDT WED AUG 5 2015
...UPDATED FOR 12Z AVIATION DISCUSSION...
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 307 AM CDT WED AUG 5 2015
THIS MORNING:
ANTICIPATING SCATTERED TO AT TIMES NUMEROUS SHOWERS/THUNDERSTORMS
EARLY THIS MORNING THROUGH THIS MORNING...MAINLY NORTHEAST OF A
LINE EXTENDING FROM GREAT BEND- WICHITA-ARKANSAS CITY...GRADUALLY
EXITING TO THE SOUTHEAST LATE MORNING/EARLY AFTERNOON. THIS
ACTIVITY IS IN RESPONSE TO MODEST/STRONG 850-700MB WARM/MOIST
ADVECTION AHEAD OF SHORTWAVE ENERGY APPROACHING FROM THE
NORTHWEST. WHILE WIDESPREAD SEVERE WEATHER IS NOT EXPECTED...AMPLE
ELEVATED INSTABILITY AND DEEP LAYER SHEAR COMBO (INCLUDING DECENT
0-3KM SHEAR FOR AN ORGANIZED WIND THREAT) SHOULD SUPPORT A HANDFUL
OF STRONG/SEVERE STORMS...CAPABLE OF MARGINALLY SEVERE LARGE HAIL
AND DAMAGING WINDS...ALONG WITH THE POTENTIAL FOR AREAS OF HEAVY
RAINFALL AND LOCALIZED FLOODING. IN FACT...POCKETS OF VERY HEAVY
RAINFALL RATES EXCEEDING 1-2 INCHES PER HOUR COULD PRODUCE
ISOLATED INSTANCES OF FLASH FLOODING.
THIS AFTERNOON-EVENING:
THUNDERSTORM CHANCES LATER THIS AFTERNOON-EVENING OVER SOUTHEAST
KS WILL BE DEPENDENT ON HOW FAR SOUTH THIS MORNING`S CONVECTIVE
OUTFLOW PUSHES. IF CONVECTIVE OUTFLOW PUSHES WELL SOUTH INTO
OK...AS ADVERTISED BY THE NAM...THEN ADDITIONAL PM STORM CHANCES
WILL LIKELY BE MINIMAL. HOWEVER...THE LESS BULLISH RAP WOULD
SUGGEST AT LEAST AN ISOLATED STRONG/SEVERE STORM CHANCE OVER
SOUTHEAST KS LATER THIS AFTERNOON-EVENING...AS IT KEEPS THE
EFFECTIVE FRONTAL ZONE A BIT FURTHER NORTH OVER SOUTHEAST KS. ALL-
IN-ALL THOUGH...BRUNT OF LATE AFTERNOON-EVENING CONVECTION SHOULD
REMAIN SOUTHEAST OF THE FORECAST AREA.
THURSDAY-FRIDAY:
A WARMING TREND IS EXPECTED FOR THURSDAY-FRIDAY...AS THE
SOUTHWEST CONUS UPPER RIDGE BUILDS/MOVES EAST ACROSS THE SOUTHERN
AND CENTRAL PLAINS. HIGH TEMPERATURES SHOULD PUSH THE CENTURY MARK
BOTH DAYS...ESPECIALLY CLOSER TO THE OK BORDER OVER SOUTH-CENTRAL
KS...WITH HEAT INDICES APPROACHING 105 DEGREES. SLIGHT TO MODEST
THUNDERSTORM CHANCES EXIST BOTH DAYS...ESPECIALLY THE NORTHEAST
HALF OF KS THURSDAY EVENING-NIGHT...AND THE NORTHERN HALF OF KS
FRIDAY EVENING-NIGHT.
ADK
.LONG TERM...(SATURDAY THROUGH TUESDAY)
ISSUED AT 307 AM CDT WED AUG 5 2015
SATURDAY-TUESDAY:
CONTINUED HOT SUMMER WEATHER SHOULD CONTINUE FOR SATURDAY-
SUNDAY...AS THE UPPER HIGH REMAINS ENTRENCHED ACROSS THE SOUTHERN
CONUS...AND A FRONTAL BOUNDARY REMAINS JUST NORTH OF THE FORECAST
AREA. DEWPOINT MAY BE TEMPERED SOME...ALTHOUGH HEAT INDICES IN THE
100-105 DEGREE RANGE (IF NOT HIGHER OVER SOUTHERN/SOUTHEAST KS)
REMAIN PLAUSIBLE. ANY THUNDERSTORM CHANCES SATURDAY-SUNDAY WILL
LIKELY BE LIMITED TO THE NORTHERN HALF OF KS AND NE DURING THE
EVENING-OVERNIGHT HOURS. SOMEWHAT COOLER WEATHER TO NEAR SEASONAL
NORMALS ALONG WITH STORM CHANCES SPREADING SOUTH IS SUPPORTED BY
THE MEDIUM RANGE CONSENSUS FOR MONDAY-TUESDAY...AS A SHORTWAVE
DROPS SOUTHEAST ACROSS THE GREAT LAKES/OHIO RIVER VALLEY...DRIVING
A COLD FRONT SOUTH. FOR NOW ONLY WENT WITH SLIGHT CHANCES POPS
SUNDAY EVENING-MONDAY.
ADK
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 637 AM CDT WED AUG 5 2015
FOR ICT-HUT-SLN-RSL-CNU...WIDESPREAD SHOWERS/THUNDERSTORMS WILL
GRADUALLY EXIT THE REGION TO THE SOUTHEAST THIS MORNING. AREAS OF
VERY HEAVY RAIN...GUSTY WINDS AND FREQUENT LIGHTNING ARE LIKELY.
MVFR CIGS COULD LINGER INTO AT LEAST EARLY AFTERNOON...DUE TO
MOIST LOW-LEVELS AND COOL ADVECTION FROM THE NORTH.
ADK
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 89 71 96 73 / 70 10 10 10
HUTCHINSON 87 70 95 71 / 70 10 10 10
NEWTON 84 69 93 71 / 80 10 10 20
ELDORADO 85 70 93 72 / 80 20 10 20
WINFIELD-KWLD 91 72 96 74 / 70 20 10 10
RUSSELL 86 68 95 69 / 60 0 10 20
GREAT BEND 88 69 96 70 / 20 0 10 10
SALINA 84 70 94 71 / 80 10 10 20
MCPHERSON 84 69 95 71 / 80 10 10 20
COFFEYVILLE 88 71 94 75 / 80 40 10 20
CHANUTE 85 70 92 72 / 80 40 10 30
IOLA 83 70 91 72 / 80 40 10 30
PARSONS-KPPF 86 71 93 74 / 80 40 10 20
&&
.ICT WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
307 AM CDT WED AUG 5 2015
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 307 AM CDT WED AUG 5 2015
THIS MORNING:
ANTICIPATING SCATTERED TO AT TIMES NUMEROUS SHOWERS/THUNDERSTORMS
EARLY THIS MORNING THROUGH THIS MORNING...MAINLY NORTHEAST OF A
LINE EXTENDING FROM GREAT BEND- WICHITA-ARKANSAS CITY...GRADUALLY
EXITING TO THE SOUTHEAST LATE MORNING/EARLY AFTERNOON. THIS
ACTIVITY IS IN RESPONSE TO MODEST/STRONG 850-700MB WARM/MOIST
ADVECTION AHEAD OF SHORTWAVE ENERGY APPROACHING FROM THE
NORTHWEST. WHILE WIDESPREAD SEVERE WEATHER IS NOT EXPECTED...AMPLE
ELEVATED INSTABILITY AND DEEP LAYER SHEAR COMBO (INCLUDING DECENT
0-3KM SHEAR FOR AN ORGANIZED WIND THREAT) SHOULD SUPPORT A
HANDFUL OF STRONG/SEVERE STORMS...CAPABLE OF MARGINALLY SEVERE
LARGE HAIL AND DAMAGING WINDS...ALONG WITH THE POTENTIAL FOR AREAS
OF HEAVY RAINFALL AND LOCALIZED FLOODING. IN FACT...POCKETS OF
VERY HEAVY RAINFALL RATES EXCEEDING 1-2 INCHES PER HOUR COULD
PRODUCE ISOLATED INSTANCES OF FLASH FLOODING.
THIS AFTERNOON-EVENING:
THUNDERSTORM CHANCES LATER THIS AFTERNOON-EVENING OVER SOUTHEAST
KS WILL BE DEPENDENT ON HOW FAR SOUTH THIS MORNING`S CONVECTIVE
OUTFLOW PUSHES. IF CONVECTIVE OUTFLOW PUSHES WELL SOUTH INTO
OK...AS ADVERTISED BY THE NAM...THEN ADDITIONAL PM STORM CHANCES
WILL LIKELY BE MINIMAL. HOWEVER...THE LESS BULLISH RAP WOULD
SUGGEST AT LEAST AN ISOLATED STRONG/SEVERE STORM CHANCE OVER
SOUTHEAST KS LATER THIS AFTERNOON-EVENING...AS IT KEEPS THE
EFFECTIVE FRONTAL ZONE A BIT FURTHER NORTH OVER SOUTHEAST KS. ALL-
IN-ALL THOUGH...BRUNT OF LATE AFTERNOON-EVENING CONVECTION SHOULD
REMAIN SOUTHEAST OF THE FORECAST AREA.
THURSDAY-FRIDAY:
A WARMING TREND IS EXPECTED FOR THURSDAY-FRIDAY...AS THE
SOUTHWEST CONUS UPPER RIDGE BUILDS/MOVES EAST ACROSS THE SOUTHERN
AND CENTRAL PLAINS. HIGH TEMPERATURES SHOULD PUSH THE CENTURY MARK
BOTH DAYS...ESPECIALLY CLOSER TO THE OK BORDER OVER SOUTH-CENTRAL
KS...WITH HEAT INDICES APPROACHING 105 DEGREES. SLIGHT TO MODEST
THUNDERSTORM CHANCES EXIST BOTH DAYS...ESPECIALLY THE NORTHEAST
HALF OF KS THURSDAY EVENING-NIGHT...AND THE NORTHERN HALF OF KS
FRIDAY EVENING-NIGHT.
ADK
.LONG TERM...(SATURDAY THROUGH TUESDAY)
ISSUED AT 307 AM CDT WED AUG 5 2015
SATURDAY-TUESDAY:
CONTINUED HOT SUMMER WEATHER SHOULD CONTINUE FOR SATURDAY-
SUNDAY...AS THE UPPER HIGH REMAINS ENTRENCHED ACROSS THE SOUTHERN
CONUS...AND A FRONTAL BOUNDARY REMAINS JUST NORTH OF THE FORECAST
AREA. DEWPOINT MAY BE TEMPERED SOME...ALTHOUGH HEAT INDICES IN THE
100-105 DEGREE RANGE (IF NOT HIGHER OVER SOUTHERN/SOUTHEAST KS)
REMAIN PLAUSIBLE. ANY THUNDERSTORM CHANCES SATURDAY-SUNDAY WILL
LIKELY BE LIMITED TO THE NORTHERN HALF OF KS AND NE DURING THE
EVENING-OVERNIGHT HOURS. SOMEWHAT COOLER WEATHER TO NEAR SEASONAL
NORMALS ALONG WITH STORM CHANCES SPREADING SOUTH IS SUPPORTED BY
THE MEDIUM RANGE CONSENSUS FOR MONDAY-TUESDAY...AS A SHORTWAVE
DROPS SOUTHEAST ACROSS THE GREAT LAKES/OHIO RIVER VALLEY...DRIVING
A COLD FRONT SOUTH. FOR NOW ONLY WENT WITH SLIGHT CHANCES POPS
SUNDAY EVENING-MONDAY.
ADK
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1150 PM CDT TUE AUG 4 2015
A RATHER INTERESTING AVIATION FORECAST OVERNIGHT INTO EARLY
WED...AS WARM ADVECTION AHEAD OF THE SURFACE LOW PRESSURE AREA IN
SW KS LEADS TO CHANCES OF SHOWERS/STORMS EARLY WED MORNING. EXPECT
MOST AREAS TO REMAIN DRY FOR THE FIRST FEW HOURS...BUT THINK TSRA
CHANCES WILL INCREASE LATE TONIGHT...INITIALLY OVER CENTRAL KS.
WHERE A FEW STORMS MAY PROPAGATE SE INTO CENTRAL KS AFTER 08Z.
CHANCES FOR AREAS NE OF KICT LOOK TO INCREASE LATE TONIGHT
TOWARDS 08-09Z AS MOISTURE TRANSPORT AND WARM ADVECTION INCREASES
ACROSS SOUTH CENTRAL KS...AHEAD OF THE MAIN SURFACE LOW. THIS WILL
LEAD TO CONVECTION BECOMING MORE NUMEROUS FROM KSLN SE TO KCNU
EARLY WED MORNING. SO WILL GO WITH VCTS FOR KCNU/KSLN FOR EARLY
WED.
WILL SEE A GRADUAL PUSH TO THE EAST OF THE STORM ACTIVITY ON WED
MORNING...WHICH WILL KEEP VCTS/SHRA OVER THE KCNU TAF FOR MOST OF
WED...WITH SHRA ENDING WEST TO EAST. AFTER THE STORMS MOVE OUT IN
CENTRAL KS...COULD SEE SOME MVFR CIGS FOR KICT/KHUT AND KRSL/KSLN
FOR EARLY WED MORNING.
KETCHAM
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 89 71 96 73 / 20 10 10 10
HUTCHINSON 89 70 95 71 / 20 10 10 10
NEWTON 86 69 93 71 / 40 10 10 20
ELDORADO 87 70 93 72 / 50 20 10 20
WINFIELD-KWLD 91 72 96 74 / 30 20 10 10
RUSSELL 88 68 95 69 / 20 0 10 20
GREAT BEND 89 69 96 70 / 10 0 10 10
SALINA 86 70 94 71 / 40 10 10 20
MCPHERSON 87 69 95 71 / 30 10 10 20
COFFEYVILLE 89 71 94 75 / 60 40 10 20
CHANUTE 86 70 92 72 / 70 40 10 30
IOLA 84 70 91 72 / 70 40 10 30
PARSONS-KPPF 87 71 93 74 / 70 40 10 20
&&
.ICT WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS JACKSON KY
127 PM EDT WED AUG 5 2015
.UPDATE...
ISSUED AT 127 PM EDT WED AUG 5 2015
ADDITIONAL ADJUSTMENTS TO THE FORECAST EARLY THIS AFTERNOON. HAD
TO LOWER AFTERNOON HIGHS JUST SLIGHTLY BASED ON HOURLY TRENDS.
INCREASING HIGH AND MID LEVEL CLOUDS WILL ALSO HELP DAMPEN SOME OF
THE HEAT LATER THIS AFTERNOON IN OUR SOUTHWEST AS A STORM COMPLEX
MOVES SOLIDLY INTO CENTRAL KY AND AS A RESULT OF CONVECTION
FIRING OVER THE TN VALLEY. IN THE EAST...LINGERING STRATUS HAS
SLOWED DIURNAL RISES BUT TEMPERATURES WILL CATCH BACK UP TO
FORECASTED LEVELS UNDER MOSTLY SUNNY TO PARTLY CLOUDY SKIES EARLY
THIS AFTERNOON. THE THREAT OF RAIN WILL HOLD OFF JUST A BIT
LONGER IN THE NORTH AND EAST WITH MORE GRADUAL RISE IN TEMPS.
UPDATE ISSUED AT 1121 AM EDT WED AUG 5 2015
UPDATE THIS MORNING TO BRING GRIDS IN LINE WITH HOURLY OBS. ALSO
TWEAKED POPS AND SKY GRIDS FOR CURRENT TRENDS. LATEST HRRR BRINGS
ONGOING CONVECTION OVER FAR WESTERN KENTUCKY INTO OUR AREA BY LATE
TODAY...EARLY THIS EVENING. ALSO EXPECTING SCATTERED SHOWERS AND
THUNDERSTORMS TO FIRE ACROSS THE TN VALLEY...CUMBERLAND PLATEAU
BEFORE LIFTING NORTHEAST INTO OUR FORECAST AREA BETWEEN ROUGHLY 3
AND 5 PM. OTHERWISE CAN NOT RULE OUT SOME ISOLD POP UPS THROUGH
THE EARLY AFTERNOON AS WE APPROACH THE CONVECTIVE TEMP...ABOUT
86.
UPDATE ISSUED AT 816 AM EDT WED AUG 5 2015
CURRENT CONDITIONS ACROSS THE AREA THIS MORNING FEATURE SOME AREAS
OF FOG ACROSS THE AREA. THIS WILL LIKELY CONTINUE A COUPLE MORE
HOURS BEFORE DISSIPATING. SOME SLIGHT TO CHANCE POPS REMAIN IN THE
FORECAST THIS MORNING BUT WITH A FEW RETURNS BEGINNING TO DEVELOP
IN CENTRAL KY SO WILL KEEP THE CURRENT FORECAST AS IS. SO WILL
ANTICIPATE INCREASED SHOWERS AND THUNDERSTORMS AS THE AFTERNOON
APPROACHES WITH THE HEAVY RAINFALL THREAT ARRIVING LATE THIS
AFTERNOON INTO THE EVENING. HAVE UPDATED THE GRIDS WITH THE LATEST
OBS AND SENT THEM TO NDFD.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 421 AM EDT WED AUG 5 2015
CURRENT CONDITIONS ACROSS THE AREA FEATURE A QUASI-STATIONARY
BOUNDARY ACROSS THE OH VALLEY AND INTO THE MID MS VALLEY. ALONG
THIS BOUNDARY CURRENTLY...PLENTY OF CLOUD COVER CONTINUES TO MOVE
THROUGH KY ASSOCIATED WITH DECAYING UPSTREAM CONVECTION. ACROSS
THE AREA...PLENTY OF MOISTURE REMAINS IN PLACE WITH DEW POINTS
ACROSS THE AREA IN THE MID 60S. SUCH A MOIST AND UNSTABLE
ATMOSPHERE WILL BE CONDUCIVE FOR EARLY CONVECTION THIS MORNING AND
ESPECIALLY HEADING INTO THE DAY. WILL DEAL WITH SOME FOG IN THE
DEEPER RIVER VALLEYS THIS MORNING BEFORE THIS BURNS OFF JUST AFTER
14Z.
ALOFT...THE PATTERN REMAINS WITH A TROUGH OVER THE EASTERN CONUS
WITH THE BASE OF THE TROUGH ROUNDING OUT JUST ALONG THE TN VALLEY.
HEADING INTO THE DAY A STRONG WAVE HAS TRAVERSED THE RIDGE OVER
THE FRONT RANGE AND NOW STREAKS EAST INTO THE CENTRAL PLAINS AND
THEN WESTERN KY. SOME UPPER LEVEL ENERGY AHEAD OF THIS FEATURE
ALREADY NOW INTO WESTERN KY WILL BE ENOUGH FOR SOME CONVECTION TO
DEVELOP INTO EASTERN KY BY 15Z. THE BETTER FORCING AND UPPER LEVEL
SUPPORT ARRIVES LATER TODAY AND INTO THE AFTERNOON. MODELS HAVE
BEEN OFF ON THE TIMING OF THIS FEATURE BUT CURRENT CONDITIONS
UPSTREAM IN MO AND KS WOULD SUGGEST AN EARLY START TO THE ACTIVITY
TODAY. MODEL SOUNDINGS HEADING INTO THE AFTERNOON...WHILE A TAD
OVER DONE...SUGGEST PLENTY OF INSTABILITY IN PLACE WITH PWATS IN
THE 1.6 TO 2.0 RANGE. ONCE AGAIN THIS WILL POSE A THREAT OF HEAVY
RAINFALL AND TRAINING STORMS. A RATHER HIGH FREEZING LEVEL AND
LACK OF WINDS ALOFT WILL MAKE FOR MOSTLY SUB SEVERE STORMS THIS
AFTERNOON AND EVENING...THOUGH A FEW STORMS MAY BE STRONG. THE
BULK OF THESE INGREDIENTS ARRIVE THIS EVENING INTO TONIGHT AS THE
AFOREMENTIONED STRONG WAVE ARRIVES IN EAST KY.
CONCERNING TONIGHT AND INTO THURSDAY...MODEL PROFILES FOR THIS
TIME PERIOD INDICATE QUITE A STEEP WARM LAYER...NEAR 2 INCH
PWATS...AND CAPE PROFILES EQUALLY DISTRIBUTED ALONG THE COLUMN
ALLOWING FOR EFFICIENT RAINFALL PRODUCTION. WHILE STORM MOTION
WILL BE A BIT QUICKER AT 10 KNOTS OR MORE ALLOWING LESS RESIDENCE
TIME...THE PREVIOUSLY MENTIONED INGREDIENTS WILL BE ENOUGH TO SET
THE STAGE FOR HEAVY RAINFALL WITH FLASH FLOODING POSSIBLE.
THEREFORE...HAVE EXTENDED THE FLASH FLOOD WATCH TO INCLUDE THE
SOUTHERN COUNTIES AND THUS...ALL OF EASTERN KENTUCKY. HAVE ALSO
INCLUDED SOME HEAVY RAINFALL MENTION IN THE WEATHER GRIDS TO
ACCOUNT FOR THIS. FOR THURSDAY...AS THE UPPER TROUGH DEEPENS AND
THE TROUGH AXIS MOVES THROUGH KENTUCKY WITH THE BETTER SUPPORT
ALOFT AND INSTABILITY FROM THE DAYS HEATING...THOUGH LESS...WILL
ALLOW HEAVY RAINFALL PRODUCING STORMS TO CONTINUE INTO THURSDAY
AFTERNOON.
ONE FORECAST ISSUE CONCERNING CONVECTION LATER TONIGHT AND INTO
THURSDAY...MOST LIKELY THERE WILL BE SOME ORGANIZATION WITH STORMS
DEVELOPING ALONG THE BOUNDARY AND UPPER LEVEL SUPPORT IN PLACE...SO
THIS WOULD MAKE PRECIP RATHER INTERMITTENT AT TIMES THROUGH THE
PERIOD. IF ANY OF THIS DEVELOPS DURING THIS TIME OR A COLD POOL
DEVELOPS...THERE MAY BECOME A WIND THREAT BUT THIS IS UNLIKELY AT
THIS TIME.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 527 AM EDT WED AUG 5 2015
THE MODELS REMAIN IN DECENT AGREEMENT WITH A MODESTLY AMPLIFIED
LONG WAVE PATTERN THROUGH THE WEEKEND...BEFORE THE PATTERN
SHARPENS UP MORE BY EARLY NEXT WEEK. THE MAIN FEATURES OF INTEREST
WILL BE A PERSISTENT UPPER LEVEL RIDGE THAT WILL MOVE FROM THE
DESERT SOUTHWEST TO THE ARKLATEX REGION...BEFORE GRADUALLY
RETREATING BACK TO THE WEST ONCE AGAIN AND AMPLIFYING ACROSS THE
PLAINS. MEANWHILE...TROUGHING IN THE EASTERN CONUS WILL GRADUALLY
MOVE OFF THE COAST...BEFORE EVENTUALLY BEING REPLACED WITH A
DEEPER TROUGH AS A SHORT WAVE INTENSIFIES AS IT HEADS ACROSS THE
GREAT LAKES/OHIO VALLEY REGIONS BY EARLY NEXT WEEK. DETAILS ON HOW
ALL OF THIS PLAYS OUT STILL REMAIN UNCERTAIN...SO HAVE CONTINUED
TO STICK CLOSE TO THE BLENDED GUIDANCE APPROACH.
A TROUGH AXIS WILL BE SHIFTING THROUGH OUR AREA THURSDAY NIGHT
INTO FRIDAY...WITH SHOWERS AND THUNDERSTORMS ON THE
DECREASE...ESPECIALLY AFTER MIDNIGHT. GENERALLY DRY WEATHER WILL
RESUME ACROSS THE AREA FOR THE WEEKEND...AS THE UPPER LEVEL RIDGE
BUILDS IN FROM THE SOUTHWEST. UNSETTLED WEATHER WILL THEN RETURN
FOR EARLY NEXT WEEK...AS THE DEEPER TROUGHING SWINGS THROUGH THE
OHIO VALLEY. TEMPERATURES WILL GENERALLY AVERAGE NEAR NORMAL
THROUGH THE PERIOD...WITH LOWER HUMIDITY ON THE HORIZON BY THE
MIDDLE OF NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 127 PM EDT WED AUG 5 2015
MORNING FOG AND LOW STRATUS HAS FINALLY DISSIPATED. COMPLEX OF
STORMS CROSSING CENTRAL KY AND ACTIVITY DRIFTING NORTHWARD FROM
THE TN VALLEY WILL BRING THE THREAT OF THUNDERSTORMS BACK INTO
THE FORECAST DURING THE MID TO LATE AFTERNOON TIME FRAME...
AFFECTING OUR SOUTHWESTERN MOST TERMINALS FIRST...THEN SPREADING
NORTHEAST. INCREASED COVERAGE WILL BEGIN LATER TONIGHT AS A STORM
SYSTEM APPROACHES FROM THE WEST. LOOK FOR AN EXTENDED PERIOD OF
RAIN AND MVFR TO IFR CONDITIONS ACROSS THE AREA AS A STORM SYSTEM
PASSES THROUGH THE REGION LATE TONIGHT THROUGH THURSDAY. EXPECT
MAINLY LIGHT WINDS THROUGH THE TAF PERIOD OUTSIDE OF
THUNDERSTORMS...BUT BECOMING MORE SOUTHWESTERLY THURSDAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM 5 PM EDT THIS AFTERNOON THROUGH LATE
THURSDAY NIGHT FOR KYZ044-050>052-058>060-068-069-079-080-
083>088-104-106>120.
&&
$$
UPDATE...RAY
SHORT TERM...SHALLENBERGER
LONG TERM...GEOGERIAN
AVIATION...RAY
AREA FORECAST DISCUSSION
NWS JACKSON KY
1121 AM EDT WED AUG 5 2015
.UPDATE...
ISSUED AT 1121 AM EDT WED AUG 5 2015
UPDATE THIS MORNING TO BRING GRIDS IN LINE WITH HOURLY OBS. ALSO
TWEAKED POPS AND SKY GRIDS FOR CURRENT TRENDS. LATEST HRRR BRINGS
ONGOING CONVECTION OVER FAR WESTERN KENTUCKY INTO OUR AREA BY LATE
TODAY...EARLY THIS EVENING. ALSO EXPECTING SCATTERED SHOWERS AND
THUNDERSTORMS TO FIRE ACROSS THE TN VALLEY...CUMBERLAND PLATEAU
BEFORE LIFTING NORTHEAST INTO OUR FORECAST AREA BETWEEN ROUGHLY 3
AND 5 PM. OTHERWISE CAN NOT RULE OUT SOME ISOLD POP UPS THROUGH
THE EARLY AFTERNOON AS WE APPROACH THE CONVECTIVE TEMP...ABOUT
86.
UPDATE ISSUED AT 816 AM EDT WED AUG 5 2015
CURRENT CONDITIONS ACROSS THE AREA THIS MORNING FEATURE SOME AREAS
OF FOG ACROSS THE AREA. THIS WILL LIKELY CONTINUE A COUPLE MORE
HOURS BEFORE DISSIPATING. SOME SLIGHT TO CHANCE POPS REMAIN IN THE
FORECAST THIS MORNING BUT WITH A FEW RETURNS BEGINNING TO DEVELOP
IN CENTRAL KY SO WILL KEEP THE CURRENT FORECAST AS IS. SO WILL
ANTICIPATE INCREASED SHOWERS AND THUNDERSTORMS AS THE AFTERNOON
APPROACHES WITH THE HEAVY RAINFALL THREAT ARRIVING LATE THIS
AFTERNOON INTO THE EVENING. HAVE UPDATED THE GRIDS WITH THE LATEST
OBS AND SENT THEM TO NDFD.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 421 AM EDT WED AUG 5 2015
CURRENT CONDITIONS ACROSS THE AREA FEATURE A QUASI-STATIONARY
BOUNDARY ACROSS THE OH VALLEY AND INTO THE MID MS VALLEY. ALONG
THIS BOUNDARY CURRENTLY...PLENTY OF CLOUD COVER CONTINUES TO MOVE
THROUGH KY ASSOCIATED WITH DECAYING UPSTREAM CONVECTION. ACROSS
THE AREA...PLENTY OF MOISTURE REMAINS IN PLACE WITH DEW POINTS
ACROSS THE AREA IN THE MID 60S. SUCH A MOIST AND UNSTABLE
ATMOSPHERE WILL BE CONDUCIVE FOR EARLY CONVECTION THIS MORNING AND
ESPECIALLY HEADING INTO THE DAY. WILL DEAL WITH SOME FOG IN THE
DEEPER RIVER VALLEYS THIS MORNING BEFORE THIS BURNS OFF JUST AFTER
14Z.
ALOFT...THE PATTERN REMAINS WITH A TROUGH OVER THE EASTERN CONUS
WITH THE BASE OF THE TROUGH ROUNDING OUT JUST ALONG THE TN VALLEY.
HEADING INTO THE DAY A STRONG WAVE HAS TRAVERSED THE RIDGE OVER
THE FRONT RANGE AND NOW STREAKS EAST INTO THE CENTRAL PLAINS AND
THEN WESTERN KY. SOME UPPER LEVEL ENERGY AHEAD OF THIS FEATURE
ALREADY NOW INTO WESTERN KY WILL BE ENOUGH FOR SOME CONVECTION TO
DEVELOP INTO EASTERN KY BY 15Z. THE BETTER FORCING AND UPPER LEVEL
SUPPORT ARRIVES LATER TODAY AND INTO THE AFTERNOON. MODELS HAVE
BEEN OFF ON THE TIMING OF THIS FEATURE BUT CURRENT CONDITIONS
UPSTREAM IN MO AND KS WOULD SUGGEST AN EARLY START TO THE ACTIVITY
TODAY. MODEL SOUNDINGS HEADING INTO THE AFTERNOON...WHILE A TAD
OVER DONE...SUGGEST PLENTY OF INSTABILITY IN PLACE WITH PWATS IN
THE 1.6 TO 2.0 RANGE. ONCE AGAIN THIS WILL POSE A THREAT OF HEAVY
RAINFALL AND TRAINING STORMS. A RATHER HIGH FREEZING LEVEL AND
LACK OF WINDS ALOFT WILL MAKE FOR MOSTLY SUB SEVERE STORMS THIS
AFTERNOON AND EVENING...THOUGH A FEW STORMS MAY BE STRONG. THE
BULK OF THESE INGREDIENTS ARRIVE THIS EVENING INTO TONIGHT AS THE
AFOREMENTIONED STRONG WAVE ARRIVES IN EAST KY.
CONCERNING TONIGHT AND INTO THURSDAY...MODEL PROFILES FOR THIS
TIME PERIOD INDICATE QUITE A STEEP WARM LAYER...NEAR 2 INCH
PWATS...AND CAPE PROFILES EQUALLY DISTRIBUTED ALONG THE COLUMN
ALLOWING FOR EFFICIENT RAINFALL PRODUCTION. WHILE STORM MOTION
WILL BE A BIT QUICKER AT 10 KNOTS OR MORE ALLOWING LESS RESIDENCE
TIME...THE PREVIOUSLY MENTIONED INGREDIENTS WILL BE ENOUGH TO SET
THE STAGE FOR HEAVY RAINFALL WITH FLASH FLOODING POSSIBLE.
THEREFORE...HAVE EXTENDED THE FLASH FLOOD WATCH TO INCLUDE THE
SOUTHERN COUNTIES AND THUS...ALL OF EASTERN KENTUCKY. HAVE ALSO
INCLUDED SOME HEAVY RAINFALL MENTION IN THE WEATHER GRIDS TO
ACCOUNT FOR THIS. FOR THURSDAY...AS THE UPPER TROUGH DEEPENS AND
THE TROUGH AXIS MOVES THROUGH KENTUCKY WITH THE BETTER SUPPORT
ALOFT AND INSTABILITY FROM THE DAYS HEATING...THOUGH LESS...WILL
ALLOW HEAVY RAINFALL PRODUCING STORMS TO CONTINUE INTO THURSDAY
AFTERNOON.
ONE FORECAST ISSUE CONCERNING CONVECTION LATER TONIGHT AND INTO
THURSDAY...MOST LIKELY THERE WILL BE SOME ORGANIZATION WITH STORMS
DEVELOPING ALONG THE BOUNDARY AND UPPER LEVEL SUPPORT IN PLACE...SO
THIS WOULD MAKE PRECIP RATHER INTERMITTENT AT TIMES THROUGH THE
PERIOD. IF ANY OF THIS DEVELOPS DURING THIS TIME OR A COLD POOL
DEVELOPS...THERE MAY BECOME A WIND THREAT BUT THIS IS UNLIKELY AT
THIS TIME.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 527 AM EDT WED AUG 5 2015
THE MODELS REMAIN IN DECENT AGREEMENT WITH A MODESTLY AMPLIFIED
LONG WAVE PATTERN THROUGH THE WEEKEND...BEFORE THE PATTERN
SHARPENS UP MORE BY EARLY NEXT WEEK. THE MAIN FEATURES OF INTEREST
WILL BE A PERSISTENT UPPER LEVEL RIDGE THAT WILL MOVE FROM THE
DESERT SOUTHWEST TO THE ARKLATEX REGION...BEFORE GRADUALLY
RETREATING BACK TO THE WEST ONCE AGAIN AND AMPLIFYING ACROSS THE
PLAINS. MEANWHILE...TROUGHING IN THE EASTERN CONUS WILL GRADUALLY
MOVE OFF THE COAST...BEFORE EVENTUALLY BEING REPLACED WITH A
DEEPER TROUGH AS A SHORT WAVE INTENSIFIES AS IT HEADS ACROSS THE
GREAT LAKES/OHIO VALLEY REGIONS BY EARLY NEXT WEEK. DETAILS ON HOW
ALL OF THIS PLAYS OUT STILL REMAIN UNCERTAIN...SO HAVE CONTINUED
TO STICK CLOSE TO THE BLENDED GUIDANCE APPROACH.
A TROUGH AXIS WILL BE SHIFTING THROUGH OUR AREA THURSDAY NIGHT
INTO FRIDAY...WITH SHOWERS AND THUNDERSTORMS ON THE
DECREASE...ESPECIALLY AFTER MIDNIGHT. GENERALLY DRY WEATHER WILL
RESUME ACROSS THE AREA FOR THE WEEKEND...AS THE UPPER LEVEL RIDGE
BUILDS IN FROM THE SOUTHWEST. UNSETTLED WEATHER WILL THEN RETURN
FOR EARLY NEXT WEEK...AS THE DEEPER TROUGHING SWINGS THROUGH THE
OHIO VALLEY. TEMPERATURES WILL GENERALLY AVERAGE NEAR NORMAL
THROUGH THE PERIOD...WITH LOWER HUMIDITY ON THE HORIZON BY THE
MIDDLE OF NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 816 AM EDT WED AUG 5 2015
WITH RECENT RAINFALL AND LIGHT WINDS...PATCHY FOG HAS DEVELOPED
ACROSS THE AREA. EXPECT FOG TO DISSIPATE BY 14Z THIS MORNING AS
THE INVERSION BEGINS TO BREAK. HEADING INTO THIS
AFTERNOON...SHOWERS AND THUNDERSTORMS WILL BECOME MORE NUMEROUS
AND HAVE ADDED VCTS TO THE TAF SITES AFTER 18Z. INCREASED COVERAGE
WILL BEGIN ACROSS THE AREA AFTER 00Z TONIGHT WITH THE BETTER LIFT
MOVING IN. HAVE ADDED A TEMPO GROUP TO THE TAF SITES BY THE 06Z
PERIOD FOR BELOW FILED MINS DUE TO THUNDERSTORMS. COVERAGE DURING
THIS TIME WILL BE QUITE EXTENSIVE. EXPECT MAINLY LIGHT WINDS
THROUGH THE TAF PERIOD OUTSIDE OF THUNDERSTORMS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM 5 PM EDT THIS AFTERNOON THROUGH LATE
THURSDAY NIGHT FOR KYZ044-050>052-058>060-068-069-079-080-
083>088-104-106>120.
&&
$$
UPDATE...RAY
SHORT TERM...SHALLENBERGER
LONG TERM...GEOGERIAN
AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
138 AM EDT WED AUG 5 2015
...UPDATED AVIATION DISCUSSION...
...FORECAST UPDATE...
ISSUED AT 1245 AM EDT WED AUG 5 2015
UPDATED THE FORECAST TO GET RID OF AFTERNOON WORDING AND REFRESH TO
CURRENT TEMPS/DEWPTS/PRECIP. THE MAJORITY OF THE OVERNIGHT HOURS
LOOK DRY ALTHOUGH WE SHOULD SEE RE-DEVELOPMENT OF CONVECTION TOWARD
SUNRISE AS THE LOW LEVEL JET RAMPS UP TO OUR WEST INCREASING
ISENTROPIC LIFT. THE CURRENT FORECAST HANDLES THIS WELL. DID ADD
MORE PATCHY FOG THROUGH THE OVERNIGHT HOURS AS MANY PLACES WILL SEE
LIGHT GROUND FOG OVERNIGHT IN THE WAKE OF EVENING RAINS.
ISSUED AT 953 PM EDT TUE AUG 4 2015
CONVECTION CONTINUES TO DIE THIS EVENING WITH THE LOSS OF DAYTIME
HEATING. EXPECT THIS TREND TO CONTINUE INTO THE OVERNIGHT HOURS.
UNCERTAINTY REMAINS RATHER HIGH ON WHAT WILL OCCUR EARLY WEDNESDAY
MORNING...AS THE GUIDANCE SUITE IS STRUGGLING WITH ONGOING
CONVECTION LEADING LITTLE CONFIDENCE TO THEIR SOLUTIONS FOR TONIGHT.
THAT BEING SAID...THE 04/23Z HRRR SEEMS TO HAVE THE BEST HANDLE OF
THE ONGOING SITUATION SO WILL LEAN ON THAT FOR THE OVERNIGHT HOURS.
THIS SOLUTION KEEPS MUCH OF THE OVERNIGHT DRY...SO WILL TREND THE
FORECAST THAT WAY. THE SYNOPTIC MODELS ARE TRYING TO HINT AT
ISENTROPIC ASCENT PICKING UP TOWARDS DAWN WEDNESDAY...BUT SEEING
VERY LITTLE HINTS OF THAT OCCURRING TO THE WEST CURRENTLY.
THEREFORE...WILL TREND DRIER BUT WILL STILL KEEP POPS IN MAINLY
ACROSS SOUTH-CENTRAL KENTUCKY WEDNESDAY MORNING.
.SHORT TERM (NOW THROUGH THURSDAY NIGHT)...
ISSUED AT 315 PM EDT TUE AUG 4 2015
SCATTERED SHOWERS AND STORMS HAVE DEVELOPED ON A DIFFERENTIAL
HEATING AND DEW POINT BOUNDARY ACROSS CENTRAL AND SOUTH CENTRAL KY.
THE SLOW MOVING NATURE OF THESE STORMS MAY PUT DOWN SOME HEAVY
RAINFALL IN SPOTS. A FEW STRONGER STORMS ARE POSSIBLE GIVEN THE
AMOUNT OF INSTABILITY, ALTHOUGH OVERALL ORGANIZATION IS NOT EXPECTED
DUE TO THE LACK OF STRONGER DEEP LAYER SHEAR. SHOWERS/STORMS WILL
PUSH OFF TO THE EAST THROUGH THE EARLY EVENING HOURS, BEFORE A
RELATIVE LULL THROUGH THE OVERNIGHT. CAN`T RULE OUT A FEW SHOWERS
DROPPING IN FROM THE NW, SO WILL LEAVE SMALL CHANCES IN THROUGH THE
OVERNIGHT. LOOK FOR LOWS IN THE UPPER 60S NE TO LOW 70S SW.
DO EXPECT TO SEE ISOLATED TO WIDELY SCATTERED SHOWER/STORM ACTIVITY
MAINLY CONFINDED TO OUR WESTERN CWA ROUGHLY ALONG THE STALLED
BOUNDARY THAT WILL BE IN PLACE. EXPECT MOST HIGHS TO BE IN THE UPPER
80S.
...FLASH FLOOD WATCH LATE WEDNESDAY EVENING THROUGH EARLY FRIDAY...
AS WE ENTER LATER WEDNESDAY AFTERNOON AND EVENING A SLOW MOVING
UPPER WAVE AND ASSOCIATED SURFACE LOW WILL MOVE INTO THE MISSISSIPPI
RIVER VALLEY AND THEN LOWER OHIO RIVER VALLEY. AS THIS OCCURS DEEPER
MOISTURE WILL BE TRANSPORTED IN THROUGH A DEEP LAYER, PARTICULARLY
OF NOTE WILL BE A 40 KNOT LOW LEVEL JET. PRECIPITABLE WATER AMOUNTS
WILL RANGE IN THE 2 - 2.5 RANGE FROM LATE WEDNESDAY NIGHT THROUGH
THURSDAY AS THE SLOW MOVING SYSTEM MOVES THROUGH. SOME AREAS WILL
LIKELY SEE REPEATED ROUNDS OF HEAVY RAINFALL. DURING THIS TIME, 1.5
TO 2 INCHES OF RAIN IS EXPECTED WITH LOCALLY HIGHER AMOUNTS POSSIBLE
ACROSS SOUTHERN IN AND NORTH CENTRAL KY. GIVEN THE METEOROLOGICAL
SETUP, RECENT HEAVY RAINFALL IN SPOTS, AND A WPC SLIGHT RISK OF
EXCESSIVE RAINFALL ELECTED TO ISSUE A FLASH FLOOD WATCH IN
COORDINATION WITH JKL FROM LATER WEDNESDAY EVENING THROUGH EARLY
FRIDAY MORNING ACROSS THE NORTHERN TWO-THIRDS OF THE CWA. AT THIS
POINT, EXPECT THE HEAVIEST AXIS OF RAIN TO FALL ALONG AND ON EITHER
SIDE OF THE I-64 CORRIDOR.
THE SYSTEM SLIDES EAST BY THURSDAY NIGHT WITH PRECIPITATION ENDING
FROM WEST TO EAST. FLASH FLOOD WATCH IS SET TO EXPIRE AT 2 AM EDT/1
AM CDT.
.LONG TERM (FRIDAY THROUGH WEDNESDAY)...
ISSUED AT 325 PM EDT TUE AUG 4 2015
MID LEVEL VORTICITY MAXIMUM WILL PUSH ON OFF TO THE EAST ON FRIDAY
AND IN ITS WAKE, A BIT OF MID-LEVEL RIDGING WILL BUILD IN FROM THE
WEST. THIS SHOULD GIVE US A TEMPORARY BREAK FROM THE RAINS FROM
MIDWEEK. HOWEVER, THIS DRY TREND WILL NOT LAST ALL THAT LONG. THE
LATEST FORECASTS SUGGEST THAT A MID-LEVEL RIDGE AXIS WILL SET BACK
UP ACROSS TEXAS BY THE LATE PART OF THE WEEKEND AND INTO EARLY NEXT
WEEK. THE UPPER LEVEL RIDGE IS EXPECTED TO BE MORE FLAT, THUS, THE
OHIO VALLEY WILL REMAIN ON THE PERIPHERY OF THE RIDGE AXIS SETTING
THE STAGE FOR MORE UNSETTLED WEATHER AS MID-LEVEL VORT MAXES ROUND
THE TOP OF THE RIDGE.
WHILE FORECAST CONFIDENCE IS LOW REGARDING THE TIMING OF THE WAVES
IN THE LATE PART OF THE PERIOD, IT DOES APPEAR THAT SEVERAL WILL
IMPACT THE REGION FROM LATE SATURDAY NIGHT THROUGH TUESDAY. THE
FIRST MAY AFFECT OUR REGION LATE SATURDAY NIGHT, FOLLOWED BY ANOTHER
ONE ON MONDAY. THE PATTERN IS ONE THAT FAVORS ONE OR MORE MESOSCALE
CONVECTIVE COMPLEXES DEVELOPING AND THEN RACING FROM THE CENTRAL
PLAINS THROUGH THE OHIO VALLEY. IT IS REALLY NOT ALL THAT
SURPRISING GIVEN THIS PATTERN HAS BEEN SEEN IN RECENT WEEKS. THE
THREAT OF ADDITIONAL HEAVY RAINFALL IS CERTAINLY THERE, AND WE MAY
SEE ADDITIONAL HYDRO ISSUES IN SOME PARTS OF THE AREA EARLY NEXT
WEEK, DEPENDING ON WHERE THE EVENTUAL MCS TRACK SETS UP.
TEMPERATURES WILL START OFF BELOW NORMAL FOR THE PERIOD WITH LOW-MID
80S ACROSS THE REGION ON FRIDAY. A BRIEF MODERATION IN TEMPS LOOKS
LIKELY FOR SATURDAY AND SUNDAY WITH HIGHS IN THE MID 80S NORTH AND
MID-UPPER 80S IN THE SOUTH. LOW TO MID 80S LOOK LIKELY FOR MONDAY
AND TUESDAY AS WELL, GIVEN THAT WE`RE EXPECTING CLOUDS AND
PRECIPITATION TO BE IN THE AREA. IF CONVECTIVE COVERAGE IS LESS,
THEN TEMPERATURES MAY NEED TO BE INCREASED SLIGHTLY IN SUBSEQUENT
FORECASTS. OVERNIGHT LOWS DURING THE PERIOD WILL BE IN THE UPPER
60S TO THE LOWER 70S.
&&
.AVIATION (06Z TAF UPDATE)...
ISSUED AT 135 AM EDT WED AUG 5 2015
EARLY THIS MORNING WE WILL BE IN A LULL IN BETWEEN WAVES OF
CONVECTION. SOME LIGHT BR HAS FORMED OVER THE AREA AND EXPECT MORE
AS WE GO THROUGH THE PRE-DAWN HOURS SO WILL INCLUDE AN MVFR GROUP AT
ALL TAF SITES THIS MORNING. MOST OF THE SHORT RANGE AND HIGH-RES
MODELS INDICATE THAT A LOW LEVEL JET AND ISENTROPIC LIFT SHOULD
INCREASE TOWARD SUNRISE RESULTING IN RENEWED CONVECTIVE DEVELOPMENT
WHICH COULD RESULT IN A FEW SHOWERS NEAR THE TAF SITES AROUND AND
JUST AFTER SUNRISE. CONFIDENCE IN THIS HAPPENING AND ANY RESULTANT
FLIGHT RESTRICTIONS ARE LOW SO WILL MENTION WITH VCSH ATTM. A
BETTER CHANCE FOR CONVECTION EXISTS LATER TODAY AS A SLOW MOVING
UPPER TROUGH AND WEAK SFC LOW PUSH EASTWARD ALONG A NEARLY
STATIONARY SFC BOUNDARY. SHOWERS AND STORMS WILL BECOME LIKELY AS
THIS WEATHER SYSTEM MOVES INTO THE AREA LATER THIS
AFTERNOON/EVENING.
WINDS WILL BE LIGHT AND VARIABLE THROUGH THE MORNING HOURS. THIS
AFTERNOON THEY WILL BECOME PREDOMINANTLY SW UNDER 7 KTS AND THEN
MORE EASTERLY TOWARD THE END OF THE TAF PERIOD AS THE WEATHER SYSTEM
DRAWS NEAR.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...FLASH FLOOD WATCH FROM THIS EVENING THROUGH LATE THURSDAY NIGHT
FOR KYZ023>043-045>049-053>057-063>067.
IN...FLASH FLOOD WATCH FROM THIS EVENING THROUGH LATE THURSDAY NIGHT
FOR INZ076>079-083-084-089>092.
&&
$$
UPDATE.........KJD/AMS
SHORT TERM.....BJS
LONG TERM......MJ
AVIATION.......AMS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1249 AM EDT WED AUG 5 2015
...FORECAST UPDATE...
ISSUED AT 1245 AM EDT WED AUG 5 2015
UPDATED THE FORECAST TO GET RID OF AFTERNOON WORDING AND REFRESH TO
CURRENT TEMPS/DEWPTS/PRECIP. THE MAJORITY OF THE OVERNIGHT HOURS
LOOK DRY ALTHOUGH WE SHOULD SEE RE-DEVELOPMENT OF CONVECTION TOWARD
SUNRISE AS THE LOW LEVEL JET RAMPS UP TO OUR WEST INCREASING
ISENTROPIC LIFT. THE CURRENT FORECAST HANDLES THIS WELL. DID ADD
MORE PATCHY FOG THROUGH THE OVERNIGHT HOURS AS MANY PLACES WILL SEE
LIGHT GROUND FOG OVERNIGHT IN THE WAKE OF EVENING RAINS.
ISSUED AT 953 PM EDT TUE AUG 4 2015
CONVECTION CONTINUES TO DIE THIS EVENING WITH THE LOSS OF DAYTIME
HEATING. EXPECT THIS TREND TO CONTINUE INTO THE OVERNIGHT HOURS.
UNCERTAINTY REMAINS RATHER HIGH ON WHAT WILL OCCUR EARLY WEDNESDAY
MORNING...AS THE GUIDANCE SUITE IS STRUGGLING WITH ONGOING
CONVECTION LEADING LITTLE CONFIDENCE TO THEIR SOLUTIONS FOR TONIGHT.
THAT BEING SAID...THE 04/23Z HRRR SEEMS TO HAVE THE BEST HANDLE OF
THE ONGOING SITUATION SO WILL LEAN ON THAT FOR THE OVERNIGHT HOURS.
THIS SOLUTION KEEPS MUCH OF THE OVERNIGHT DRY...SO WILL TREND THE
FORECAST THAT WAY. THE SYNOPTIC MODELS ARE TRYING TO HINT AT
ISENTROPIC ASCENT PICKING UP TOWARDS DAWN WEDNESDAY...BUT SEEING
VERY LITTLE HINTS OF THAT OCCURRING TO THE WEST CURRENTLY.
THEREFORE...WILL TREND DRIER BUT WILL STILL KEEP POPS IN MAINLY
ACROSS SOUTH-CENTRAL KENTUCKY WEDNESDAY MORNING.
.SHORT TERM (NOW THROUGH THURSDAY NIGHT)...
ISSUED AT 315 PM EDT TUE AUG 4 2015
SCATTERED SHOWERS AND STORMS HAVE DEVELOPED ON A DIFFERENTIAL
HEATING AND DEW POINT BOUNDARY ACROSS CENTRAL AND SOUTH CENTRAL KY.
THE SLOW MOVING NATURE OF THESE STORMS MAY PUT DOWN SOME HEAVY
RAINFALL IN SPOTS. A FEW STRONGER STORMS ARE POSSIBLE GIVEN THE
AMOUNT OF INSTABILITY, ALTHOUGH OVERALL ORGANIZATION IS NOT EXPECTED
DUE TO THE LACK OF STRONGER DEEP LAYER SHEAR. SHOWERS/STORMS WILL
PUSH OFF TO THE EAST THROUGH THE EARLY EVENING HOURS, BEFORE A
RELATIVE LULL THROUGH THE OVERNIGHT. CAN`T RULE OUT A FEW SHOWERS
DROPPING IN FROM THE NW, SO WILL LEAVE SMALL CHANCES IN THROUGH THE
OVERNIGHT. LOOK FOR LOWS IN THE UPPER 60S NE TO LOW 70S SW.
DO EXPECT TO SEE ISOLATED TO WIDELY SCATTERED SHOWER/STORM ACTIVITY
MAINLY CONFINDED TO OUR WESTERN CWA ROUGHLY ALONG THE STALLED
BOUNDARY THAT WILL BE IN PLACE. EXPECT MOST HIGHS TO BE IN THE UPPER
80S.
...FLASH FLOOD WATCH LATE WEDNESDAY EVENING THROUGH EARLY FRIDAY...
AS WE ENTER LATER WEDNESDAY AFTERNOON AND EVENING A SLOW MOVING
UPPER WAVE AND ASSOCIATED SURFACE LOW WILL MOVE INTO THE MISSISSIPPI
RIVER VALLEY AND THEN LOWER OHIO RIVER VALLEY. AS THIS OCCURS DEEPER
MOISTURE WILL BE TRANSPORTED IN THROUGH A DEEP LAYER, PARTICULARLY
OF NOTE WILL BE A 40 KNOT LOW LEVEL JET. PRECIPITABLE WATER AMOUNTS
WILL RANGE IN THE 2 - 2.5 RANGE FROM LATE WEDNESDAY NIGHT THROUGH
THURSDAY AS THE SLOW MOVING SYSTEM MOVES THROUGH. SOME AREAS WILL
LIKELY SEE REPEATED ROUNDS OF HEAVY RAINFALL. DURING THIS TIME, 1.5
TO 2 INCHES OF RAIN IS EXPECTED WITH LOCALLY HIGHER AMOUNTS POSSIBLE
ACROSS SOUTHERN IN AND NORTH CENTRAL KY. GIVEN THE METEOROLOGICAL
SETUP, RECENT HEAVY RAINFALL IN SPOTS, AND A WPC SLIGHT RISK OF
EXCESSIVE RAINFALL ELECTED TO ISSUE A FLASH FLOOD WATCH IN
COORDINATION WITH JKL FROM LATER WEDNESDAY EVENING THROUGH EARLY
FRIDAY MORNING ACROSS THE NORTHERN TWO-THIRDS OF THE CWA. AT THIS
POINT, EXPECT THE HEAVIEST AXIS OF RAIN TO FALL ALONG AND ON EITHER
SIDE OF THE I-64 CORRIDOR.
THE SYSTEM SLIDES EAST BY THURSDAY NIGHT WITH PRECIPITATION ENDING
FROM WEST TO EAST. FLASH FLOOD WATCH IS SET TO EXPIRE AT 2 AM EDT/1
AM CDT.
.LONG TERM (FRIDAY THROUGH WEDNESDAY)...
ISSUED AT 325 PM EDT TUE AUG 4 2015
MID LEVEL VORTICITY MAXIMUM WILL PUSH ON OFF TO THE EAST ON FRIDAY
AND IN ITS WAKE, A BIT OF MID-LEVEL RIDGING WILL BUILD IN FROM THE
WEST. THIS SHOULD GIVE US A TEMPORARY BREAK FROM THE RAINS FROM
MIDWEEK. HOWEVER, THIS DRY TREND WILL NOT LAST ALL THAT LONG. THE
LATEST FORECASTS SUGGEST THAT A MID-LEVEL RIDGE AXIS WILL SET BACK
UP ACROSS TEXAS BY THE LATE PART OF THE WEEKEND AND INTO EARLY NEXT
WEEK. THE UPPER LEVEL RIDGE IS EXPECTED TO BE MORE FLAT, THUS, THE
OHIO VALLEY WILL REMAIN ON THE PERIPHERY OF THE RIDGE AXIS SETTING
THE STAGE FOR MORE UNSETTLED WEATHER AS MID-LEVEL VORT MAXES ROUND
THE TOP OF THE RIDGE.
WHILE FORECAST CONFIDENCE IS LOW REGARDING THE TIMING OF THE WAVES
IN THE LATE PART OF THE PERIOD, IT DOES APPEAR THAT SEVERAL WILL
IMPACT THE REGION FROM LATE SATURDAY NIGHT THROUGH TUESDAY. THE
FIRST MAY AFFECT OUR REGION LATE SATURDAY NIGHT, FOLLOWED BY ANOTHER
ONE ON MONDAY. THE PATTERN IS ONE THAT FAVORS ONE OR MORE MESOSCALE
CONVECTIVE COMPLEXES DEVELOPING AND THEN RACING FROM THE CENTRAL
PLAINS THROUGH THE OHIO VALLEY. IT IS REALLY NOT ALL THAT
SURPRISING GIVEN THIS PATTERN HAS BEEN SEEN IN RECENT WEEKS. THE
THREAT OF ADDITIONAL HEAVY RAINFALL IS CERTAINLY THERE, AND WE MAY
SEE ADDITIONAL HYDRO ISSUES IN SOME PARTS OF THE AREA EARLY NEXT
WEEK, DEPENDING ON WHERE THE EVENTUAL MCS TRACK SETS UP.
TEMPERATURES WILL START OFF BELOW NORMAL FOR THE PERIOD WITH LOW-MID
80S ACROSS THE REGION ON FRIDAY. A BRIEF MODERATION IN TEMPS LOOKS
LIKELY FOR SATURDAY AND SUNDAY WITH HIGHS IN THE MID 80S NORTH AND
MID-UPPER 80S IN THE SOUTH. LOW TO MID 80S LOOK LIKELY FOR MONDAY
AND TUESDAY AS WELL, GIVEN THAT WE`RE EXPECTING CLOUDS AND
PRECIPITATION TO BE IN THE AREA. IF CONVECTIVE COVERAGE IS LESS,
THEN TEMPERATURES MAY NEED TO BE INCREASED SLIGHTLY IN SUBSEQUENT
FORECASTS. OVERNIGHT LOWS DURING THE PERIOD WILL BE IN THE UPPER
60S TO THE LOWER 70S.
&&
.AVIATION (00Z TAF UPDATE)...
ISSUED AT 744 PM EDT TUE AUG 4 2015
A LINE OF THUNDERSTORMS PACKING STRONG WINDS AND IFR VSBYS WILL PASS
THROUGH KSDF AT THE START OF THE PERIOD. THIS LINE MAY PERSIST EAST
INTO LEXINGTON...BUT WILL SEE HOW THINGS PROGRESS BEFORE ADDING MORE
THAN VCTS AT THIS TIME. AFTER THIS LINE MOVES THROUGH...CONFIDENCE
LOWERS QUITE A BIT IN WHAT MAY OCCUR OVERNIGHT. THE LATEST HI-RES
GUIDANCE SUITE SUGGESTS ACTIVITY WILL STRUGGLE TO GET GOING
OVERNIGHT...SO HAVE PLAYED DOWN THUNDERSTORM CHANCES AFTER THIS
INITIAL LINE MOVES THROUGH. THAT BEING SAID...CANNOT RULE OUT
CONVECTION FIRING ACROSS MISSOURI AND WESTERN KENTUCKY
TONIGHT...GETTING INTO KSDF OR KBWG EARLY WEDNESDAY MORNING. IF
CONVECTION DOES NOT REDEVELOP OVERNIGHT...THEN SOME LIGHT FOG WILL
BE POSSIBLE AT KWBG OR KLEX.
WEDNESDAY WILL ALL DEPEND ON HOW CONVECTION PLAYS OUT
OVERNIGHT...BUT ADDITIONAL THUNDERSTORMS WILL BE POSSIBLE TOWARD THE
END OF THE PERIOD AS ANOTHER SYSTEM APPROACHES FROM THE WEST.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...FLASH FLOOD WATCH FROM THIS EVENING THROUGH LATE THURSDAY NIGHT
FOR KYZ023>043-045>049-053>057-063>067.
IN...FLASH FLOOD WATCH FROM THIS EVENING THROUGH LATE THURSDAY NIGHT
FOR INZ076>079-083-084-089>092.
&&
$$
UPDATE.........KJD/AMS
SHORT TERM.....BJS
LONG TERM......MJ
AVIATION.......KJD
AREA FORECAST DISCUSSION
NWS DULUTH MN
1229 PM CDT WED AUG 5 2015
.UPDATE...
ISSUED AT 1229 PM CDT WED AUG 5 2015
UPDATED FOR 18Z AVIATION DISCUSSION BELOW
UPDATE ISSUED AT 647 AM CDT WED AUG 5 2015
UPDATED AVIATION SECTION BELOW. THERE IS AS MUCH FOG AS IS LIKELY
TO FORM BY NOW...AND IS FAIRLY PATCHY IN NATURE...EVEN IF
VISIBILITIES ARE PRETTY LOW. VISIBILITIES SHOULD IMPROVE FROM NOW
ON.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 311 AM CDT WED AUG 5 2015
THE FOCUS IS ON PCPN CHANCES AND RAINFALL FOR TONIGHT AND
THURSDAY. MOST OF THE MODELS DELAYED THE TIMING WITH WHICH PCPN
MOVES INTO THE FORECAST AREA...SO WAS ABLE TO DELAY THE PCPN
CHANCES...RESULTING IN HOLDING THE ONSET OF PCPN OFF UNTIL VERY
LATE TONIGHT AND THURSDAY MORNING.
EARLY THIS MORNING...HIGH PRESSURE CENTERED NEAR THE
MINNESOTA/ONTARIO BORDER IS RESULTING IN VERY LIGHT WINDS AND
MOSTLY CLEAR SKIES ACROSS THE NORTHLAND. THE RELATIVELY HUMID
CONDITIONS COULD RESULT IN PATCHY FOG UNTIL THE RISING SUN BURNS
IT OFF AFTER SUNRISE.
TODAY...THE SURFACE HIGH PRESSURE OVER THE NORTHLAND WILL
GRADUALLY SHIFT EAST OF THE FORECAST AREA...WHILE AN UPPER LEVEL
RIDGE IN THE DAKOTAS SHIFTS INTO THE NORTHLAND. BOTH FEATURES
SHOULD HELP PREVENT ANY PCPN TODAY AND HELP KEEP THE NORTHLAND
MOSTLY SUNNY TO PARTLY CLOUDY. THE GFS/NAM12 MODEL SOUNDINGS
INDICATE CONVECTIVE TEMPERATURES SHOULD BE LOW ENOUGH TO POP SOME
CUMULUS THIS AFTERNOON...EVEN THOUGH THE HRRR IS NOT HINTING AT
THIS. MOST MODELS AND MOS...INCLUDING THE GFS AND NAM MOS...ARE
GIVING HIGH TEMPERATURES SIMILAR TO YESTERDAY.
HOWEVER...CONSIDERING THE 850 HPA TEMPERATURES WILL BE
SIGNIFICANTLY WARMER...DECIDED TO LEAN ON THE WARMER NAM12 FOR
HIGHS TODAY. THERE SHOULD BE WIDESPREAD HIGHS IN THE MIDDLE TO
UPPER 70S...BUT IT WILL BE A BIT COOLER CLOSE TO LAKE SUPERIOR DUE
TO A LAKE BREEZE.
TONIGHT AND EARLY THURSDAY...A POTENT SHORTWAVE WILL BE IN
MANITOBA THIS EVENING...AND MOVE EAST INTO NW ONTARIO OVERNIGHT
AND INTO THURSDAY MORNING. THE WAVE WILL BE ASSOCIATED A SMALL BUT
RELATIVELY DEEP LOW WHICH WILL MOVE EAST ACROSS SOUTHERN MANITOBA
TOWARDS NW ONTARIO. A 25 TO 35 KNOT SSW LOW LEVEL JET WILL PUMP
WARM AND HUMID AIR INTO THE NORTHLAND OVERNIGHT. MOST MODELS ARE
INDICATING PCPN DEVELOPING LATE TONIGHT AND THURSDAY
MORNING...PRIMARILY ACROSS THE WESTERN FORECAST AREA.
HOWEVER...THE ECMWF CONTINUES TO STAND OUT IN BEING FASTER AT
BRINGING THE PCPN INTO THE FORECAST AREA...AND TO MUCH MORE
EASTERN EXTENT. DELAYED THE PCPN CHANCES BASED ON THE GENERAL
CONSENSUS OF THE GFS/SREF/GEM/GEMREG/NAM12/NCEPWRF MODELS...BUT
KEPT LOW CHANCES FARTHER EAST TO ACCOUNT FOR THE ECMWF. THE
NAM12/GFS/SREF ARE INDICATING THERE COULD BE UP TO SEVERAL HUNDRED
J/KG OF MUCAPE WITH THE PCPN LATE TONIGHT AND THURSDAY
MORNING...SO KEPT THUNDER IN THE FORECAST.
THURSDAY AFTERNOON AND EARLY EVENING...THE MANITOBA LOW WILL MOVE
INTO NW ONTARIO...AND MOST PCPN ASSOCIATED WITH IT SHOULD STAY
NORTH OF MINNESOTA. HOWEVER...OTHER SHORTWAVES WILL BE CUTTING
ACROSS THE NORTHERN PLAINS INTO THE UPPER MIDWEST...AND THESE
WAVES COULD HELP TRIGGER SHOWERS AND STORMS ACROSS THE NORTHLAND.
THE GFS/NAM12/SREF ARE INDICATING MUCAPE COULD BUILD TO OVER 1000
J/KG OVER THE WESTERN AND SOUTHERN FORECAST AREA DURING THE
AFTERNOON. THE LACK OF DEEP LAYER WIND SHEAR WILL BE A LIMITING
FACTOR FOR SEVERE WEATHER THOUGH. CONSIDERING THE CAPE
THOUGH...THERE COULD BE SHORT LIVED STRONGER CELLS OVER THE
WESTERN AND SW FORECAST AREA. THE PRECIPITABLE WATER VALUES WILL
INCREASE TO ABOUT 1.5 TO 1.75 INCHES...SO MODERATE TO BRIEF HEAVY
RAIN IS POSSIBLE WITH THE STORMS. HIGH TEMPERATURES SHOULD BE IN
THE MIDDLE TO UPPER 70S...BUT COOLER BY THE LAKE DUE TO AN EVEN
STRONGER EAST TO NE FLOW OVER THE LAKE.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 311 AM CDT WED AUG 5 2015
THURSDAY NIGHT THE LEADING SHORTWAVE...850MB LOW...AND WAVE OF
WARM AIR ADVECTION AND MOISTURE ADVECTION MOVES THROUGH THE AREA.
THIS SHOULD BRING A PERIOD OF SHOWERS AND THUNDERSTORMS TO MUCH OF
THE FORECAST AREA DURING THE OVERNIGHT AND EARLY FRIDAY TIME
RANGE. THIS WILL PUT US INTO A WARM AND HUMID AIRMASS FOR
FRIDAY...WITH CONTINUING CHANCES FOR SHOWERS AND THUNDERSTORMS AND
WARM TEMPERATURES. HAVE PUT THEM INTO THE 70S FOR NOW...BUT
DEPENDING ON CLOUD COVER MAY NEED TO BOOST THEM IF WE CAN GET SOME
MORE SUNSHINE. WE REMAIN IN THIS WARM AND HUMID AIRMASS WITH WEAK
SHORTWAVES MOVING THROUGH THE AREA TO BRING CHANCES FOR SHOWERS
AND THUNDERSTORMS THROUGH THE WEEKEND. HIGH TEMPERATURES IN THE
70S TO AROUND 80 TO CONTINUE WITH SMALL CHANCES FOR SHOWERS AND
THUNDERSTORMS.
UPPER LEVEL RIDGING TO BUILD OVER THE ROCKIES BY EARLY NEXT
WEEK...PUTTING THE NORTHLAND INTO NORTHWEST FLOW WITH SHORTWAVES
DIVING THROUGH THE FLOW THROUGH THE MIDDLE PART OF THE WEEK.
TEMPERATURES TO GET A LITTLE COOLER FOR MONDAY BEFORE WARMING
AGAIN TOWARDS THE MIDDLE OF THE WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1229 PM CDT WED AUG 5 2015
EXPECT VRF CONDITIONS TODAY THROUGH THE EVENING AS HIGH PRESSURE
RIDGE SLIDES ACROSS THE NORTHLAND AHEAD OF A FRONTAL BOUNDARY IN
THE DAKOTAS. WINDS WILL BE LIGHT AND OUT OF THE SOUTHEAST... BUT
WILL BECOME VARIABLE AT TIMES... ESPECIALLY FOR DLH DUE TO AN
EXPECTED LAKE BREEZE THIS AFTERNOON. EARLY TUESDAY MORNING AFTER
08Z... A WARM FRONT WILL APPROACH THE NORTHLAND INTRODUCING
SCATTERED SHOWERS AND STORMS FROM WEST TO EAST... WITH STORM
COVERAGE INCREASING AND CIGS/VIS GOING TO MVFR/IFR AFTER 15Z AND
BEYOND. WINDS WILL ALSO BECOME GUSTY DURING THIS TIME.
THERE IS A CHANCE OF FOG PATCHY FOG OVERNIGHT... BUT NAM BUFR
SOUNDINGS AND NAM-MOS GUIDANCE ARE INDICATING HYR WILL HAVE THE
BEST REASONABLE CHANCE SO INCLUDED IN A TEMPO GROUP ACCORDINGLY
BETWEEN 09Z AND 12Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 74 53 74 61 / 0 20 60 80
INL 75 54 77 57 / 0 40 50 60
BRD 80 58 78 63 / 0 40 60 80
HYR 77 53 78 61 / 0 10 50 70
ASX 73 51 78 59 / 0 0 30 70
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...NONE.
&&
$$
SHORT TERM...GROCHOCINSKI
LONG TERM...LE
AVIATION...MCLOVIN
AREA FORECAST DISCUSSION
NWS DULUTH MN
649 AM CDT WED AUG 5 2015
.UPDATE...
ISSUED AT 647 AM CDT WED AUG 5 2015
UPDATED AVIATION SECTION BELOW. THERE IS AS MUCH FOG AS IS LIKELY
TO FORM BY NOW...AND IS FAIRLY PATCHY IN NATURE...EVEN IF
VISIBILITIES ARE PRETTY LOW. VISIBILITIES SHOULD IMPROVE FROM NOW
ON.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 311 AM CDT WED AUG 5 2015
THE FOCUS IS ON PCPN CHANCES AND RAINFALL FOR TONIGHT AND
THURSDAY. MOST OF THE MODELS DELAYED THE TIMING WITH WHICH PCPN
MOVES INTO THE FORECAST AREA...SO WAS ABLE TO DELAY THE PCPN
CHANCES...RESULTING IN HOLDING THE ONSET OF PCPN OFF UNTIL VERY
LATE TONIGHT AND THURSDAY MORNING.
EARLY THIS MORNING...HIGH PRESSURE CENTERED NEAR THE
MINNESOTA/ONTARIO BORDER IS RESULTING IN VERY LIGHT WINDS AND
MOSTLY CLEAR SKIES ACROSS THE NORTHLAND. THE RELATIVELY HUMID
CONDITIONS COULD RESULT IN PATCHY FOG UNTIL THE RISING SUN BURNS
IT OFF AFTER SUNRISE.
TODAY...THE SURFACE HIGH PRESSURE OVER THE NORTHLAND WILL
GRADUALLY SHIFT EAST OF THE FORECAST AREA...WHILE AN UPPER LEVEL
RIDGE IN THE DAKOTAS SHIFTS INTO THE NORTHLAND. BOTH FEATURES
SHOULD HELP PREVENT ANY PCPN TODAY AND HELP KEEP THE NORTHLAND
MOSTLY SUNNY TO PARTLY CLOUDY. THE GFS/NAM12 MODEL SOUNDINGS
INDICATE CONVECTIVE TEMPERATURES SHOULD BE LOW ENOUGH TO POP SOME
CUMULUS THIS AFTERNOON...EVEN THOUGH THE HRRR IS NOT HINTING AT
THIS. MOST MODELS AND MOS...INCLUDING THE GFS AND NAM MOS...ARE
GIVING HIGH TEMPERATURES SIMILAR TO YESTERDAY.
HOWEVER...CONSIDERING THE 850 HPA TEMPERATURES WILL BE
SIGNIFICANTLY WARMER...DECIDED TO LEAN ON THE WARMER NAM12 FOR
HIGHS TODAY. THERE SHOULD BE WIDESPREAD HIGHS IN THE MIDDLE TO
UPPER 70S...BUT IT WILL BE A BIT COOLER CLOSE TO LAKE SUPERIOR DUE
TO A LAKE BREEZE.
TONIGHT AND EARLY THURSDAY...A POTENT SHORTWAVE WILL BE IN
MANITOBA THIS EVENING...AND MOVE EAST INTO NW ONTARIO OVERNIGHT
AND INTO THURSDAY MORNING. THE WAVE WILL BE ASSOCIATED A SMALL BUT
RELATIVELY DEEP LOW WHICH WILL MOVE EAST ACROSS SOUTHERN MANITOBA
TOWARDS NW ONTARIO. A 25 TO 35 KNOT SSW LOW LEVEL JET WILL PUMP
WARM AND HUMID AIR INTO THE NORTHLAND OVERNIGHT. MOST MODELS ARE
INDICATING PCPN DEVELOPING LATE TONIGHT AND THURSDAY
MORNING...PRIMARILY ACROSS THE WESTERN FORECAST AREA.
HOWEVER...THE ECMWF CONTINUES TO STAND OUT IN BEING FASTER AT
BRINGING THE PCPN INTO THE FORECAST AREA...AND TO MUCH MORE
EASTERN EXTENT. DELAYED THE PCPN CHANCES BASED ON THE GENERAL
CONSENSUS OF THE GFS/SREF/GEM/GEMREG/NAM12/NCEPWRF MODELS...BUT
KEPT LOW CHANCES FARTHER EAST TO ACCOUNT FOR THE ECMWF. THE
NAM12/GFS/SREF ARE INDICATING THERE COULD BE UP TO SEVERAL HUNDRED
J/KG OF MUCAPE WITH THE PCPN LATE TONIGHT AND THURSDAY
MORNING...SO KEPT THUNDER IN THE FORECAST.
THURSDAY AFTERNOON AND EARLY EVENING...THE MANITOBA LOW WILL MOVE
INTO NW ONTARIO...AND MOST PCPN ASSOCIATED WITH IT SHOULD STAY
NORTH OF MINNESOTA. HOWEVER...OTHER SHORTWAVES WILL BE CUTTING
ACROSS THE NORTHERN PLAINS INTO THE UPPER MIDWEST...AND THESE
WAVES COULD HELP TRIGGER SHOWERS AND STORMS ACROSS THE NORTHLAND.
THE GFS/NAM12/SREF ARE INDICATING MUCAPE COULD BUILD TO OVER 1000
J/KG OVER THE WESTERN AND SOUTHERN FORECAST AREA DURING THE
AFTERNOON. THE LACK OF DEEP LAYER WIND SHEAR WILL BE A LIMITING
FACTOR FOR SEVERE WEATHER THOUGH. CONSIDERING THE CAPE
THOUGH...THERE COULD BE SHORT LIVED STRONGER CELLS OVER THE
WESTERN AND SW FORECAST AREA. THE PRECIPITABLE WATER VALUES WILL
INCREASE TO ABOUT 1.5 TO 1.75 INCHES...SO MODERATE TO BRIEF HEAVY
RAIN IS POSSIBLE WITH THE STORMS. HIGH TEMPERATURES SHOULD BE IN
THE MIDDLE TO UPPER 70S...BUT COOLER BY THE LAKE DUE TO AN EVEN
STRONGER EAST TO NE FLOW OVER THE LAKE.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 311 AM CDT WED AUG 5 2015
THURSDAY NIGHT THE LEADING SHORTWAVE...850MB LOW...AND WAVE OF
WARM AIR ADVECTION AND MOISTURE ADVECTION MOVES THROUGH THE AREA.
THIS SHOULD BRING A PERIOD OF SHOWERS AND THUNDERSTORMS TO MUCH OF
THE FORECAST AREA DURING THE OVERNIGHT AND EARLY FRIDAY TIME
RANGE. THIS WILL PUT US INTO A WARM AND HUMID AIRMASS FOR
FRIDAY...WITH CONTINUING CHANCES FOR SHOWERS AND THUNDERSTORMS AND
WARM TEMPERATURES. HAVE PUT THEM INTO THE 70S FOR NOW...BUT
DEPENDING ON CLOUD COVER MAY NEED TO BOOST THEM IF WE CAN GET SOME
MORE SUNSHINE. WE REMAIN IN THIS WARM AND HUMID AIRMASS WITH WEAK
SHORTWAVES MOVING THROUGH THE AREA TO BRING CHANCES FOR SHOWERS
AND THUNDERSTORMS THROUGH THE WEEKEND. HIGH TEMPERATURES IN THE
70S TO AROUND 80 TO CONTINUE WITH SMALL CHANCES FOR SHOWERS AND
THUNDERSTORMS.
UPPER LEVEL RIDGING TO BUILD OVER THE ROCKIES BY EARLY NEXT
WEEK...PUTTING THE NORTHLAND INTO NORTHWEST FLOW WITH SHORTWAVES
DIVING THROUGH THE FLOW THROUGH THE MIDDLE PART OF THE WEEK.
TEMPERATURES TO GET A LITTLE COOLER FOR MONDAY BEFORE WARMING
AGAIN TOWARDS THE MIDDLE OF THE WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 647 AM CDT WED AUG 5 2015
EARLY MORNING FOG AT KHIB AND KINL EXPECTED TO DISSIPATE BY
14Z...ALLOWING CONDITIONS TO RETURN TO VFR. WINDS EXPECTED TO
REMAIN BELOW 10KTS THROUGH THE TAF PERIOD. A PERIOD OF SHOWERS AND
THUNDERSTORMS TO MOVE INTO THE AREA FROM THE WEST AFTER 08Z
TONIGHT...POSSIBLY AFFECTING KINL AND KBRD. I HAVE INCLUDED A VCTS
GROUP IN THE TAF FOR BOTH LOCATIONS FOR NOW...BUT HAVE KEPT
CONDITIONS VFR AND EXPECT WE WILL NEED TO MAKE SOME ADJUSTMENTS TO
TIMING ON THIS CONVECTION IN THE NEXT COUPLE TAF ISSUANCES.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 74 57 74 61 / 0 20 60 80
INL 75 59 77 57 / 0 30 50 60
BRD 80 61 78 63 / 0 30 60 80
HYR 77 56 78 61 / 0 10 50 70
ASX 72 54 78 59 / 0 0 30 70
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...NONE.
&&
$$
UPDATE...LE
SHORT TERM...GROCHOCINSKI
LONG TERM...LE
AVIATION...LE
AREA FORECAST DISCUSSION
NWS DULUTH MN
338 AM CDT WED AUG 5 2015
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 311 AM CDT WED AUG 5 2015
THE FOCUS IS ON PCPN CHANCES AND RAINFALL FOR TONIGHT AND
THURSDAY. MOST OF THE MODELS DELAYED THE TIMING WITH WHICH PCPN
MOVES INTO THE FORECAST AREA...SO WAS ABLE TO DELAY THE PCPN
CHANCES...RESULTING IN HOLDING THE ONSET OF PCPN OFF UNTIL VERY
LATE TONIGHT AND THURSDAY MORNING.
EARLY THIS MORNING...HIGH PRESSURE CENTERED NEAR THE
MINNESOTA/ONTARIO BORDER IS RESULTING IN VERY LIGHT WINDS AND
MOSTLY CLEAR SKIES ACROSS THE NORTHLAND. THE RELATIVELY HUMID
CONDITIONS COULD RESULT IN PATCHY FOG UNTIL THE RISING SUN BURNS
IT OFF AFTER SUNRISE.
TODAY...THE SURFACE HIGH PRESSURE OVER THE NORTHLAND WILL
GRADUALLY SHIFT EAST OF THE FORECAST AREA...WHILE AN UPPER LEVEL
RIDGE IN THE DAKOTAS SHIFTS INTO THE NORTHLAND. BOTH FEATURES
SHOULD HELP PREVENT ANY PCPN TODAY AND HELP KEEP THE NORTHLAND
MOSTLY SUNNY TO PARTLY CLOUDY. THE GFS/NAM12 MODEL SOUNDINGS
INDICATE CONVECTIVE TEMPERATURES SHOULD BE LOW ENOUGH TO POP SOME
CUMULUS THIS AFTERNOON...EVEN THOUGH THE HRRR IS NOT HINTING AT
THIS. MOST MODELS AND MOS...INCLUDING THE GFS AND NAM MOS...ARE
GIVING HIGH TEMPERATURES SIMILAR TO YESTERDAY.
HOWEVER...CONSIDERING THE 850 HPA TEMPERATURES WILL BE
SIGNIFICANTLY WARMER...DECIDED TO LEAN ON THE WARMER NAM12 FOR
HIGHS TODAY. THERE SHOULD BE WIDESPREAD HIGHS IN THE MIDDLE TO
UPPER 70S...BUT IT WILL BE A BIT COOLER CLOSE TO LAKE SUPERIOR DUE
TO A LAKE BREEZE.
TONIGHT AND EARLY THURSDAY...A POTENT SHORTWAVE WILL BE IN
MANTIOBA THIS EVENING...AND MOVE EAST INTO NW ONTARIO OVERNIGHT
AND INTO THURSDAY MORNING. THE WAVE WILL BE ASSOCIATED A SMALL BUT
RELATIVELY DEEP LOW WHICH WILL MOVE EAST ACROSS SOUTHERN MANTIOBA
TOWARDS NW ONTARIO. A 25 TO 35 KNOT SSW LOW LEVEL JET WILL PUMP
WARM AND HUMID AIR INTO THE NORTHLAND OVERNIGHT. MOST MODELS ARE
INDICATING PCPN DEVELOPING LATE TONIGHT AND THURSDAY
MORNING...PRIMARILY ACROSS THE WESTERN FORECAST AREA.
HOWEVER...THE ECMWF CONTINUES TO STAND OUT IN BEING FASTER AT
BRINGING THE PCPN INTO THE FORECAST AREA...AND TO MUCH MORE
EASTERN EXTENT. DELAYED THE PCPN CHANCES BASED ON THE GENERAL
CONSENSUS OF THE GFS/SREF/GEM/GEMREG/NAM12/NCEPWRF MODELS...BUT
KEPT LOW CHANCES FARTHER EAST TO ACCOUNT FOR THE ECMWF. THE
NAM12/GFS/SREF ARE INDICATING THERE COULD BE UP TO SEVERAL HUNDRED
J/KG OF MUCAPE WITH THE PCPN LATE TONIGHT AND THURSDAY
MORNING...SO KEPT THUNDER IN THE FORECAST.
THURSDAY AFTERNOON AND EARLY EVENING...THE MANITOBA LOW WILL MOVE
INTO NW ONTARIO...AND MOST PCPN ASSOCIATED WITH IT SHOULD STAY
NORTH OF MINNESOTA. HOWEVER...OTHER SHORTWAVES WILL BE CUTTING
ACROSS THE NORTHERN PLAINS INTO THE UPPER MIDWEST...AND THESE
WAVES COULD HELP TRIGGER SHOWERS AND STORMS ACROSS THE NORTHLAND.
THE GFS/NAM12/SREF ARE INDICATING MUCAPE COULD BUILD TO OVER 1000
J/KG OVER THE WESTERN AND SOUTHERN FORECAST AREA DURING THE
AFTERNOON. THE LACK OF DEEP LAYER WIND SHEAR WILL BE A LIMITING
FACTOR FOR SEVERE WEATHER THOUGH. CONSIDERING THE CAPE
THOUGH...THERE COULD BE SHORT LIVED STRONGER CELLS OVER THE
WESTERN AND SW FORECAST AREA. THE PRECIPITABLE WATER VALUES WILL
INCREASE TO ABOUT 1.5 TO 1.75 INCHES...SO MODERATE TO BRIEF HEAVY
RAIN IS POSSIBLE WITH THE STORMS. HIGH TEMPERATURES SHOULD BE IN
THE MIDDLE TO UPPER 70S...BUT COOLER BY THE LAKE DUE TO AN EVEN
STRONGER EAST TO NE FLOW OVER THE LAKE.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 311 AM CDT WED AUG 5 2015
THURSDAY NIGHT THE LEADING SHORTWAVE...850MB LOW...AND WAVE OF
WARM AIR ADVECTION AND MOISTURE ADVECTION MOVES THROUGH THE AREA.
THIS SHOULD BRING A PERIOD OF SHOWERS AND THUNDERSTORMS TO MUCH OF
THE FORECAST AREA DURING THE OVERNIGHT AND EARLY FRIDAY TIME
RANGE. THIS WILL PUT US INTO A WARM AND HUMID AIRMASS FOR
FRIDAY...WITH CONTINUING CHANCES FOR SHOWERS AND THUNDERSTORMS AND
WARM TEMPERATURES. HAVE PUT THEM INTO THE 70S FOR NOW...BUT
DEPENDING ON CLOUD COVER MAY NEED TO BOOST THEM IF WE CAN GET SOME
MORE SUNSHINE. WE REMAIN IN THIS WARM AND HUMID AIRMASS WITH WEAK
SHORTWAVES MOVING THROUGH THE AREA TO BRING CHANCES FOR SHOWERS
AND THUNDERSTORMS THROUGH THE WEEKEND. HIGH TEMPERATURES IN THE
70S TO AROUND 80 TO CONTINUE WITH SMALL CHANCES FOR SHOWERS AND
THUNDERSTORMS.
UPPER LEVEL RIDGING TO BUILD OVER THE ROCKIES BY EARLY NEXT
WEEK...PUTTING THE NORTHLAND INTO NORTHWEST FLOW WITH SHORTWAVES
DIVING THROUGH THE FLOW THROUGH THE MIDDLE PART OF THE WEEK.
TEMPERATURES TO GET A LITTLE COOLER FOR MONDAY BEFORE WARMING
AGAIN TOWARDS THE MIDDLE OF THE WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1230 AM CDT WED AUG 5 2015
NORTHWEST FLOW WILL CONTINUE OVERNIGHT WITH AREA SANDWICHED
BETWEEN PERSISTENT LOW PRESSURE OVER QUEBEC AND BUILDING RIDGE
OVER CENTRAL CONUS. EXPECT A SIMILAR EVOLUTION TO VSBYS/CIGS
THROUGH SUNRISE AS OBSERVED DURING PAST SEVERAL MORNINGS WITH
MVFR/IFR VSBYS EXPECTED AS FOG DEVELOPS. PATCHES OF DENSE FOG WERE
REPORTED LAST NIGHT AND EXPECT ANOTHER CHANCE OF THE SAME SO HAVE
INCLUDED BCFG AT HIB AND INL. VSBYS LIFT TO VFR RAPIDLY AFTER
SUNRISE AND EXPECT VFR CONDITIONS TO CONTINUE THROUGH REMAINDER OF
TAF PERIOD. APPROACHING SHORTWAVE WILL BRING A POSSIBILITY OF
SHOWERS OR THUNDERSTORMS INTO HIB/INL/BRD LATE IN THE TAF PERIOD.
CONFIDENCE IN THUNDER INCREASES AFTER 06.06Z SO HAVE OPTED FOR
VCSH WITH THIS FORECAST. LATER UPDATES WILL HAVE TO MONITOR THE
THREAT OF LLWS AT DLH BETWEEN 05.22Z AND 06.03Z AS LAKE BREEZE
BACKS WINDS EASTERLY AT SURFACE WITH WEST WINDS NEAR-ALOFT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 74 57 74 61 / 0 20 60 80
INL 75 59 77 57 / 0 30 50 60
BRD 80 61 78 63 / 0 30 60 80
HYR 77 56 78 61 / 0 10 50 70
ASX 72 54 78 59 / 0 0 30 70
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...NONE.
&&
$$
SHORT TERM...GROCHOCINSKI
LONG TERM...LE
AVIATION...HUYCK
AREA FORECAST DISCUSSION
NWS JACKSON MS
ISSUED BY NATIONAL WEATHER SERVICE HUNTSVILLE AL
1222 PM CDT WED AUG 5 2015
.UPDATE...
FOR 18Z TAFS.
&&
.AVIATION...ISOLATED SHOWERS/THUNDERSTORMS HAVE DEVELOPED ALONG AND
SOUTH OF I-20. THESE MAY BRING BRIEF PERIODS OF IFR/MVFR CONDITIONS
TO JAN/GTR/MEI/HBG/HKS THIS AFTERNOON. ALL ACTIVITY SHOULD DISSIPATE
SHORTLY AFTER SUNSET LEAVING VFR CONDITIONS AT THE TAF SITES THROUGH
THE EARLY MORNING HOURS. TOWARDS THE END OF THE TAF PERIOD MODELS
HAVE SHOWERS AND THUNDERSTORMS MOVING INTO THE AREA BUT DUE TO LOW
CONFIDENCE IN THE EXACT TIMING HAVE LEFT OUT OF THE CURRENT TAF
PACKAGE.
&&
.PREV DISCUSSION... /ISSUED ISSUED BY NATIONAL WEATHER SERVICE HUNTSVILLE AL/
UPDATE...
MORNING UPDATE.
15Z SURFACE ANALYSIS INDICATED THAT A NEARLY STATIONARY FRONTAL
BOUNDARY WAS WELL TO THE NORTH OF THE FORECAST AREA ACROSS MID
MISSISSIPPI VALLEY AND INTO OHIO VALLEY REGION. A COUPLE OF WEAK
SHORT WAVES WERE ROTATING EAST-SOUTHEAST IN THE 500 MILLIBAR FLOW
ALONG THE FRONTAL BOUNDARY...WITH MID AND MAINLY HIGH CLOUDS
STREAMING SOUTHEAST ACROSS THE REGION. WILL CONTINUE WITH THE PARTLY
CLOUDY WORDING IN THE FORECAST FOR THE AFTERNOON...BASED UPON CLOUD
TRENDING.
12Z SOUNDING DATA FROM JAN AND SURROUNDING LOCATIONS INDICATED THAT
PWATS WERE INCREASING TO AT OR ABOVE 1.75 INCHES. EXPECT THAT WIDELY
SCATTERED TO SCATTERED SHRA/TSRA SHOULD DEVELOP MAINLY ALONG AND EAST
OF JAN THIS AFTERNOON. THIS SOLUTION IS SUPPORTED BY CURRENT POP
FORECAST AND HRRR MODEL TRENDING. TEMPS ARE GENERALLY IN LINE WITH
CURRENT FORECAST AND HAVE MADE LITTLE CHANGES.
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 100 74 96 75 / 24 23 38 23
MERIDIAN 97 73 94 73 / 30 28 51 33
VICKSBURG 100 75 97 75 / 20 17 22 17
HATTIESBURG 96 75 95 75 / 34 29 55 23
NATCHEZ 97 76 97 75 / 22 19 21 13
GREENVILLE 98 76 96 75 / 25 30 45 23
GREENWOOD 97 74 94 74 / 29 33 55 30
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
STUMPF/TT
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
301 PM CDT WED AUG 5 2015
.SHORT TERM...(This Evening through Friday Afternoon)
Issued at 300 PMCDT WED AUG 5 2015
Main emphasis will be exiting wave this evening and then ridging
building increased heat Friday and into the weekend.
Eastern half of CWA currently showing some increase in showers and
isolated rumbles of thunder in Harrison County in north central
Missouri. This line is focusing on the deformation zone of the
shortwave trough current stretched out over Missouri and moving to
the east southeast. There were some breaks in the clouds to allow for
a little surface-based instability north of 36 Highway...up to around
1000 J/Kg but little in the way of shear to be of major concern. With
the loss of diurnal heating this evening...and the dynamics moving
out of the region we will see an end to showers and thunderstorms.
By late tonight skies should begin to clear and subsidence will move
into the area as a ridging builds in. Some patchy fog is possible but
will not mention as it may not be widespread enough in areas that
either don`t clear much or that are still relatively dry.
Thursday will be a very pleasant day with temperatures in the 80s and
lower humidities. By Friday...the ridge translates eastward...bring
return to heat and humidity. Heat indices will be middle to upper 90s
across the area Friday afternoon.
.LONG TERM...(Friday Evening through Wednesday)
Issued at 300 PM CDT WED AUG 5 2015
A rather vigorous trough moving across southern Canada will dampen
the upper ridge positioned over the central US as we head into the
weekend. This system will force a weak surface cold front or two
through the region this weekend into early next week. A few
shortwave troughs will ride the ridge further to the south, sparking
convection along the Front Range and translating eastward along the
periphery of the ridge. Long-range models have a convective complex
making its way into the western CWA both Saturday morning and again
early Sunday. If these complexes make it into the CWA either
morning, we could end up with slightly cooler temperatures during
the morning hours; but should quickly warm up during the afternoon,
especially along and south of I-70 as thermal ridge extends across
the CWA. By early next week, the ridge begins to retrograde westward
positioning itself across the inter-mountain west, placing the CWA
into cooler and drier northwest flow aloft.
&&
.AVIATION...(For the 18Z TAFS through 18Z Thursday Afternoon)
Issued at 1240 PM CDT WED AUG 5 2015
Main concern for the short term is MVFR cig/vsby as moisture only
slowly moves east and south. Currently the terminals have cigs around
around 1000 ft except at KSTJ where the sky condition has cleared.
The RAP13 and HRRR models introduce some surface based instability so
we should see some return of clouds with a few VCSH after around 21Z
through around 03Z. This instability will be rather weak and given
sunset will drop even further so not going to carry CB at this time.
As drier air moves in late tonight...the clouds will scatter out but
some trapped ground moisture from recent rain will provide some MVFR
vsbys until around 14Z tomorrow morning when VFR will prevail for the
remainder of the period.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
SHORT TERM...Adolphson
LONG TERM...PMM
AVIATION...Adolphson
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1244 PM CDT WED AUG 5 2015
.DISCUSSION...
Issued at 429 AM CDT WED AUG 5 2015
It`s another night watching storms percolate across the Plains
States with the potential for storms to linger on through much of the
day. Looking at he big picture across the Nation early this morning,
water vapor imagery shows a moderately amplified flow across the
contiguous U.S.A. with a ridge axis along the front range of the
Rocky`s. Within the larger pattern are noted a number of shortwave
troughs that will influence our weather over the next 48 hours. first
shortwave to note is seen spinning its way into eastern Kansas early
this morning thanks to the northwest flow. Second shortwave of note
is cresting the ridge axis along the Dakota border with Canada.
Today... The shortwave in eastern Kansas has already generated some
extensive convection across Kansas early this morning, and with the
help of a 25 knot southwest nocturnal jet --as sampled off the radar
wind profilers-- more storms are bubbling up across southeast Kansas
into southwest Missouri this morning. Farther east, across central
Missouri, isentropic lift ahead of the shortwave on the 305K surface
has developed showers. Expect this activity in both areas to fill in
through the morning hours as the shortwave continues to dig to the
southeast. This does not change the going forecast much, though the
ultimate expectations have been adjusted. Still looks like much of
the region will likely get a little bit of rain today, though the
highest rainfall totals are expected in areas south of the Missouri
River as the track of the shortwave takes the focus for precipitation
more into southern Missouri. Therefore have adjusted POPs and QPF to
reflect the more southern solution that current short range models
and radar trends advertise. Severe weather is not expected as our
area will be on the "cool side" of the shortwave, thus not nearly as
much instability as there could be with 0-6KM shear values generally
staying under 25 knots. Only portion of the forecast area where the
shear and instability might be able to conspire together would be
across our far southwest corner; east central Kansas into far west
central Missouri south of Kansas City this afternoon. Shear values in
the late morning and afternoon increase into the 30 to 35 knot range
as the shortwave moves though, but it is expected that instability
will be rather poor owing to the convection and cast off
precipitation from this morning. As a result, expect much of the
activity for storms to pass across southern Missouri though the
morning and afternoon hours with the potential for precipitation
fading in the evening hours.
With the passing of the eastern Kansas shortwave today the region
should be able to dry out a little tonight and through the day
Thursday as the ridge to our west flattens out some and expands into
Missouri. This will push temperatures back up, but still leave
conditions rather nice for early August. However, the chance for
storms will quickly return Thursday night as the Canadian border
shortwave slides into the Upper Great Lakes. Enhanced moisture
transport on the nocturnal jet may be able to get storms percolating
across the region again.
Otherwise, expect the chance for storms to persist through the
weekend as the flattened ridge remains across the Plains States,
resulting in a repeated potential for storms as various shortwave
troughs run the ridge crest just to our north. Currently, Sunday
looks to have the best chance for some kind of organized storms as it
looks like a stout trough moving through the Northern Plains will
force a cold front through Kansas and Missouri sometime Sunday.
Additional implication from this is that it might be a bit warm and
muggy Friday and through the weekend, but that temperatures will back
off a little going into Monday.
&&
.AVIATION...(For the 18Z TAFS through 18Z Thursday Afternoon)
Issued at 1240 PM CDT WED AUG 5 2015
Main concern for the short term is MVFR cig/vsby as moisture only
slowly moves east and south. Currently the terminals have cigs around
around 1000 ft except at KSTJ where the sky condition has cleared.
The RAP13 and HRRR models introduce some surface based instability so
we should see some return of clouds with a few VCSH after around 21Z
through around 03Z. This instability will be rather weak and given
sunset will drop even further so not going to carry CB at this time.
As drier air moves in late tonight...the clouds will scatter out but
some trapped ground moisture from recent rain will provide some MVFR
vsbys until around 14Z tomorrow morning when VFR will prevail for the
remainder of the period.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
DISCUSSION...Cutter
AVIATION...Adolphson
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
651 PM CDT THU AUG 6 2015
.SYNOPSIS...
ISSUED AT 350 PM CDT THU AUG 6 2015
H5 ANALYSIS FROM THIS MORNING HAD A TROUGH OF LOW
PRESSURE EXTENDING FROM A CLOSED LOW OVER ALBERTA. THIS TROUGH
EXTENDED SWD INTO CENTRAL IDAHO. EAST OF THE TROUGH...A DECENT LEAD
SHORTWAVE EXTENDED ACROSS ERN MT INTO WESTERN SOUTH DAKOTA. ANOTHER
SHORTWAVE TROUGH EXTENDED FROM SERN WYOMING INTO EASTERN COLORADO.
HIGH PRESSURE REMAINED ANCHORED OVER ERN NEW MEXICO WITH A SECONDARY
LOW NOTED ACROSS THE LOWER OHIO VALLEY. AT THE SURFACE...LOW
PRESSURE WAS LOCATED OVER SOUTH CENTRAL SOUTH DAKOTA WITH A FRONTAL
BOUNDARY EXTENDING SWWD INTO THE SERN NEBRASKA PANHANDLE. EAST OF
THIS FEATURE...WINDS WERE SOUTHERLY AND DEW POINTS WERE IN THE MID
TO UPPER 60S. WEST OF THE FRONT...GUSTY NORTHWESTERLY WINDS AND MUCH
DRIER DEW POINTS IN THE 40S AND LOWER 50S WERE PRESENT ACROSS THE
NEBR PANHANDLE. THUNDERSTORMS FROM EARLIER THIS MORNING...HAD PUSHED
INTO SOUTH CENTRAL NEBRASKA AND NORTHERN KS. SKIES WERE MOSTLY CLEAR
IN THE WAKE OF THE THUNDERSTORMS FROM EARLIER TODAY...HOWEVER...A
STRIP OF LOW CLOUDS EXTENDED FROM SOUTHWESTERN NEBRASKA INTO THE
CENTRAL SANDHILLS. THIS CLOUD COVER HAS HELD TEMPS IN THE 70S THIS
AFTERNOON...WITH 80S NOTED ELSEWHERE.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 350 PM CDT THU AUG 6 2015
MAIN FORECAST CHALLENGE OVER THE NEXT 24 HOURS WILL BE THUNDERSTORM
CHANCES AS A WEAK UPPER LEVEL PV ANOMALY TRACKS ACROSS THE
DAKOTAS...WHICH WILL PUSH A COLD FRONT THROUGH THE CWA. AS OF 20Z
THE FRONT WAS SITUATED FROM NEAR MOBRIDGE SOUTH DAKOTA SOUTHWARD
THROUGH THE WESTERN SANDHILLS. CU FIELD HAS STEADILY DEEPENED ALONG
THE FRONT WITH SHOWERS AND THUNDERSTORMS DEVELOPING AS IT MOVES INTO
AN ENVIRONMENT THAT HAS BECOME INCREASINGLY UNSTABLE. MOST OF THE
CONVECTION HAS BEEN CONTAINED TO THE NE/SD BORDER AND POINTS
NORTHWARD. FURTHER DEVELOPMENT IS EXPECTED ALONG THE FRONT THROUGH
THE EVENING. THE SOUTHWARD EXTENT OF THE CONVECTION IS IN QUESTION
AS CURRENT MESOANALYSIS AND LAPS SOUNDINGS INDICATE A STRONG CAP
SOUTH OF HWY 2...A RESULT OF MORNING CONVECTION AND PERSISTENT
DAYTIME CLOUD COVER. MLCAPE HAS INCREASED TO AOA 1000 J/KG IN AREAS
THAT HAVE SEEN AMPLE SUNSHINE AND BL RECOVERY TODAY...MAINLY IN
NORTH CENTRAL NEBRASKA FROM AINSWORTH TO O`NEILL. DEEP LAYER SHEAR
IS SUPPORTIVE OF ORGANIZED ROBUST UPDRAFTS...SO THIS AREA WILL NEED
TO BE MONITORED FOR COUPLE STRONG TO SEVERE STORMS CAPABLE OF HAIL
AND GUSTY WINDS THROUGH THROUGH THE EVENING HOURS.
PRECIP CHANCES COME TO AN END BEHIND THE FRONT AS WINDS BECOME
NORTHWESTERLY AND DRIER AIR FILTERS IN FROM THE WEST. QUIET AND CALM
CONDITIONS ARE EXPECTED OVERNIGHT AS THE BOUNDARY LAYER DECOUPLES
AND LOCAL SURFACE PRESSURE TENDENCIES RELAX. LARGE SCALE SUBSIDENCE
IN THE WAKE OF THE DEPARTING PV MAX SHOULD CLEAR OUT THE MAJORITY OF
THE CLOUD OVER AS WELL.
SURFACE LEE SIDE TROUGH JUST EAST OF THE FRONT RANGE DEEPENS FRIDAY
AS DPVA INCREASES ALOFT IN ADVANCE OF THE NEXT SHORTWAVE TROUGH TO
IMPACT THE CENTRAL PLAINS. RESPONSE JUST TO THE EAST WILL BE
SOUTHERLY FLOW AND THE POLEWARD ADVECTION OF A VERY MOIST AIRMASS
INTO THE CWA. IN FACT...MODELS ARE IN SOLID AGREEMENT WITH H85
DEWPOINTS AS HIGH AS 16C TO 18C BY LATE AFTERNOON...NEAR THE
CLIMATOLOGY MAX FOR WESTERN NEBRASKA. THETA-E GRADIENT AND DEEP
MOISTURE CONVERGENCE FOCUSES ALONG THE SURFACE TROUGH WITH THE
APPROACH OF THE UPPER LEVEL SHORTWAVE...WHICH SHOULD BE ENOUGH TO
BREAK THE CAP AFTER 18Z OVER THE HIGH PLAINS OF EASTERN WY/CO/NEB
PANHANDLE. A FEW OF THE STORMS MAY MOVE INTO OUR WESTERN CWA BY LATE
AFTERNOON/EARLY EVENING. LARGE HAIL...STRONG GUSTY WINDS...AND HEAVY
RAINFALL WILL BE A CONCERN WITH ANY THUNDERSTORM...BUT THE MOST
WIDESPREAD ACTIVTY WILL MOST LIKELY OCCUR IN OUR CWA AFTER 00Z
SATURDAY.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 350 PM CDT THU AUG 6 2015
FRIDAY NIGHT THROUGH SUNDAY...IN THE MID RANGE...THE
THREAT FOR HEAVY RAIN FRIDAY NIGHT INTO EARLY SATURDAY IS THE MAIN
FORECAST CONCERN. CONVECTION IS EXPECTED TO BE ONGOING LATE FRIDAY
AFTERNOON IN THE PANHANDLE. FURTHER EAST...THE CWA WILL BE FAIRLY
CAPPED FRIDAY AFTERNOON...SO CONVECTIVE INITIATION WILL BE ACROSS
THE NEBR PANHANDLE INVOF OF THE SURFACE TROUGH AND THETAE RIDGE
AXIS. BY EARLY EVENING...THIS CONVECTION WILL TRACK EAST INTO A VERY
MOIST LOW LEVEL ENVIRONMENT. H85 DEW POINTS REACH 14 TO 16C FRIDAY
AFTERNOON ACROSS THE WEST AND SWRN CWA WITH LAYER PWATS REACHING 1.5
TO 1.75 INCHES LATE FRIDAY AFTERNOON. THIS EQUATES TO THE 99TH
PERCENTILE FOR CLIMATOLOGY. THAT BEING SAID...THERE IS A HUGE AMOUNT
OF LOW LEVEL MOISTURE AVAILABLE FOR CONVECTION FRIDAY
AFTERNOON/EVENING. AS THIS CONVECTION MOVES EAST INTO SWRN NEBRASKA
BY EARLY EVENING...ABUNDANT DEEP LAYER SHEAR...ALONG WITH THE NOSE
OF AN H850 LOW LEVEL JET WILL COMBINE OVER SWRN NEBRASKA ENHANCING
CONVECTIVE DEVELOPMENT AS THE INITIAL THUNDERSTORMS MOVE EAST INTO
SWRN NEBRASKA. WITH THESE INGREDIENTS COMING TOGETHER...HEAVY RAIN
AND THE POSSIBILITY OF SEVERE STORMS LOOKS LIKE A DECENT BET FRIDAY
EVENING/FRIDAY NIGHT. THE LATEST NAM...GFS...AND SREF PUSH A MCS
ACROSS SWRN NEBRASKA FRIDAY EVENING INTO PORTIONS OF CENTRAL
NEBRASKA OVERNIGHT. GIVEN THE DEGREE OF MOISTURE...HEAVY RAIN LOOKS
LIKE A GOOD BET AND WITH THE FORECAST DEEP LAYER SHEAR OF 40+
KTS...STORMS HAVE A GOOD POTENTIAL TO BE SEVERE. WITH THE RECENT
HEAVY RAIN ACROSS SOUTHWESTERN NEBRASKA ON TUESDAY...AND ADDITIONAL
HEAVY RAIN IN CUSTER COUNTY FROM EARLIER TODAY...3 HR FFG HAS BEEN
RUNNING AROUND 1.5 INCHES...UP TO 2.0 INCHES. WITH THE NAM AND GFS
DEVELOPING 6 HR QPF`S OF 2 TO 4 INCHES...AND AFTER COORDINATING WITH
WPC...FELT IT NECESSARY TO HOIST A FLASH FLOOD WATCH FOR SWRN
NEBRASKA FOR FRIDAY NIGHT. GIVEN THE STRONG MODEL AGREEMENT WITH
THIS SYSTEM TOMORROW NIGHT...KEEP LIKELY POPS IN THE 70 TO 80
PERCENT RANGE ACROSS SWRN NEBRASKA AND WORDED THE FCST WITH HEAVY
RAIN...PARTICULARLY SOUTH OF A LINE FROM OSHKOSH TO SARGENT...WHERE
THE FLASH FLOOD WATCH WILL BE ISSUED FOR. FOR SATURDAY...CONVECTION
WILL LINGER INTO SATURDAY MORNING IN THE EASTERN CWA WITH MAINLY DRY
CONDS EXPECTED IN THE CENTRAL AND WEST. BY LATE AFTERNOON...THE
MODELS INITIATE CONVECTION IN THE PANHANDLE AND SWRN SD. THIS SEEMS
PLAUSIBLE AS THE THETA E RIDGE WILL BE ANCHORED ACROSS THE
PANHANDLE...AND A SURFACE TROUGH WILL LINGER IN THIS AREA AS WELL.
ATTM...NOT EXPECTING CONVECTION TO SUSTAIN ITSELF AFTER EVENING...AS
THE LOW LEVEL JET IS WEAK AND FOCUSED IN THE EASTERN PANHANDLE AND
WESTERN COUNTIES.
.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY...THE LATEST LONG RANGE
MODEL SOLUTIONS...ARE TRENDING TOWARD THE DEVELOPMENT OF AN
AMPLIFIED RIDGE ACROSS THE ROCKIES OR CENTRAL PLAINS BEGINNING
EARLY NEXT WEEK. IF THIS CAN COME TO FRUITION...THE CURRENT WET
PATTERN WILL BEGIN TO DRY OUT EARLY NEXT WEEK...AND TEMPERATURES
WILL RETURN TO THE 90S. THE LATEST MEX GUIDANCE IS HINTING AT
WARMER TEMPS TOWARD THE END OF NEXT WEEK AND THIS IS SUPPORTED BY
THE ECMWF AS WELL...AS IT BUILDS A RIDGE ACROSS THE CENTRAL PLAINS
NEXT WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 651 PM CDT THU AUG 6 2015
VFR IS EXPECTED OVERNIGHT ACROSS MUCH OF WRN AND NCNTL NEB. TOWARD
MORNING...SWRN/SCNTL NEB MAY SEE FOG WITH THE RETURN MOISTURE
FROM KS. THE NAM AND RAP MODELS KEEP THIS FOG SOUTH OF I-80. SOME
STRATUS IS POSSIBLE ALSO IN THIS AREA ALSO.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM FRIDAY EVENING THROUGH LATE FRIDAY NIGHT
FOR NEZ022-035>038-056>059-069>071.
&&
$$
SYNOPSIS...CLB
SHORT TERM...MARTIN
LONG TERM...CLB
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
ISSUED BY NATIONAL WEATHER SERVICE HASTINGS NE
406 PM CDT WED AUG 5 2015
.SHORT TERM...(TONIGHT THROUGH THURSDAY)
ISSUED AT 406 PM CDT WED AUG 5 2015
MAP ANALYSIS INDICATES UPPER TROPOSPHERIC RIDGING OVER THE WESTERN
TWO-THIRDS OF THE CONUS...AND A TROUGH OVER THE EAST. AN UPPER
TROPOSPHERIC SHORT WAVE IS ALSO NOTED MOVING ACROSS PORTIONS OF
THE CENTRAL PLAINS AND MISSOURI RIVER VALLEY. AT THE SURFACE A
WEAK RIDGE OF HIGH BAROMETRIC PRESSURE IS NOTED ACROSS PORTIONS OF
THE CENTRAL PLAINS AND MISSOURI RIVER VALLEY AND AS A RESULT...THE
BOUNDARY-LAYER WIND FIELD ACROSS THE AREA REMAINS FAIRLY WEAK AND
AT TIMES VARIABLE.
GUIDANCE SUGGESTS THE UPPER TROPOSPHERIC SHORT WAVE...CURRENTLY
CLEARING THE AREA...WILL CONTINUE MOVING EAST/SOUTHEAST THROUGH
THE NEXT 24 HOURS...LIKELY CLEARING THE MISSOURI RIVER VALLEY
LATER TONIGHT. QUASI-ZONAL UPPER TROPOSPHERIC FLOW IS THEN
EXPECTED TO OVERTAKE THE AREA THROUGH THURSDAY...ALTHOUGH THERE
ARE INDICATIONS OF ANOTHER UPPER TROPOSPHERIC SHORT WAVE CLEARING
THE AREA THURSDAY INTO THURSDAY EVENING.
AN OVERALL LACK IN OMEGA WOULD OTHERWISE KEEP THE AREA DRY THROUGH
TONIGHT...BUT SOMEWHAT ENHANCED UPPER TROPOSPHERIC LAPSE RATES IN
ASSOCIATION WITH THE PASSING SHORT WAVE TROUGH AXIS COULD BE
ENOUGH TO PROMOTE WEAK SHOWER AND/OR THUNDERSTORM DEVELOPMENT
ACROSS THE SOUTH/SOUTHEASTERN TWO-THIRDS OF THE CWA. THIS IS A
SOLUTION SUPPORTED BY QPF FIELDS FROM THE NAM AND OPERATIONAL
GFS...AND TO A LESSER EXTEND THE EC. THIS IS ALSO SUPPORTED BY
SIMULATED REFLECTIVITY FROM THE HRRR AND 4KM WRF-NMM. GIVEN ALL
THIS...OPTED TO GO AHEAD WITH ~20% POPS ACROSS THE
SOUTH/SOUTHEASTERN TWO-THIRDS OF THE CWA UNTIL 00Z. DRY CONDITIONS
ARE THEN FORECAST THROUGH THE OVERNIGHT HOURS AS DIABATIC HEATING
IS LOST.
GUIDANCE THEN SUGGESTS YET ANOTHER CHANCE FOR PRECIPITATION COULD
BE REALIZED THURSDAY INTO THURSDAY EVENING AS THE SECOND UPPER
TROPOSPHERIC SHORT WAVE CLEARS THE AREA. GIVEN THIS...WENT AHEAD
WITH 20-40% POPS ACROSS MUCH OF THE CWA THURSDAY INTO THURSDAY
EVENING.
DESPITE FAIRLY RICH BOUNDARY-LAYER MOISTURE ACROSS THE
REGION...LAPSE RATES REALLY SHOULD NOT BE ANYTHING TO WRITE HOME
ABOUT AND IN FACT...GUIDANCE SUGGESTS NO MORE THAN ~500J/KG OF
POTENTIAL ENERGY WILL BE AVAILABLE FOR UPDRAFT PRODUCTION THROUGH
THIS EVENING. GIVEN THIS...WILL NOT INTRODUCE STRONG/SEVERE
THUNDERSTORM WORDING IN THE HWO. LAPSE RATES ARE SOMEWHAT MORE
RESPECTABLE THURSDAY AFTERNOON AND EVENING AND GUIDANCE RESPONDS
BY PROVIDING POTENTIAL ENERGY VALUES MORE IN THE 1000-2000J/KG
RANGE. IN ADDITION...DEEP-LAYER BULK SHEAR OF ~40KTS IS ALSO
EXPECTED THURSDAY AFTERNOON AND EVENING AND GIVEN ALL THIS...FELT
IT PRUDENT TO AT LEAST GO WITH STRONG THUNDERSTORM WORDING IN THE
HWO.
FINALLY...A CONTINUED WEAK BOUNDARY-LAYER WIND FIELD THROUGH THE
OVERNIGHT HOURS...WORKING IN CONCERT WITH A NEAR-ZERO DEW POINT
DEPRESSIONS...COULD PROMOTE AT LEAST PATCHY FOG DEVELOPMENT ACROSS
MUCH OF THE AREA TONIGHT. GIVEN THIS...WENT AHEAD WITH PATCHY FOG
IN THE GRIDS 06-14Z THURSDAY.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 406 PM CDT WED AUG 5 2015
GUIDANCE SUGGESTS QUASI-ZONAL UPPER TROPOSPHERIC FLOW WILL BE
NOTED ACROSS THE REGION THROUGH MUCH OF THE LONG-TERM FORECAST
PERIOD...WITH THE ONLY EXCEPTION BEING EARLY NEXT WEEK AS AN UPPER
TROPOSPHERIC SHORT WAVE CLEARS THE AREA AND RIDGING STRENGTHENS
OVER THE WESTERN CONUS. MULTIPLE UPPER TROPOSPHERIC PERTURBATIONS
ARE ALSO EXPECTED TO CLEAR THE AREA AND AS A
RESULT...POPS...GENERALLY IN THE 20-40% RANGE...REMAIN INTACT
ACROSS VARIOUS PORTIONS OF THE CWA THROUGH EARLY NEXT WEEK. STRONG
AND/OR SEVERE CONVECTION CERTAINLY CANNOT BE RULED OUT LATE THIS
WEEK INTO EARLY NEXT WEEK...BUT AT THIS TIME IT REMAINS TOO EARLY
TO TRY AND PIN DOWN TIMING OR PLACEMENT OF SUCH ACTIVITY.
LITTLE CHANGE IN THE BOUNDARY-LAYER AIR MASS SHOULD PROVIDE
SIMILAR TEMPERATURE READINGS FROM DAY TO DAY DURING THE LONG-TERM
FORECAST PERIOD...WITH HIGHS GENERALLY IN THE 80S AND LOWS IN THE
60S.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 106 PM CDT WED AUG 5 2015
IFR TO MVFR CONDITIONS TO START THE TAF PERIOD...FOLLOWED BY VFR
CONDITIONS LATER THIS AFTERNOON INTO TONIGHT...WITH ANOTHER
POTENTIAL ROUND OF SUB-VFR CONDITIONS AROUND SUNRISE THURSDAY.
SATELLITE IMAGERY INDICATES STRATUS PERSISTING ACROSS EASTERN
NEBRASKA AS OF THIS WRITING...WITH A CEILING BETWEEN 900 AND
1500FT AGL AT MANY LOCATIONS. SOME VISIBILITY RESTRICTION IN BR IS
ALSO BEING REPORTED. THAT SAID...SATELLITE IMAGERY AND SURFACE OBS
INDICATE THIS STRATUS IS DISSIPATING...A TREND WHICH IS EXPECTED
TO CONTINUE THROUGH THE REST OF THIS AFTERNOON. GIVEN THIS...WENT
AHEAD WITH A CEILING IN THE 900-1000FT AGL RANGE BETWEEN THE THREE
TAF SITES UNTIL 20Z...WITH VFR CONDITIONS THEREAFTER. VFR
CONDITIONS SHOULD THEN CONTINUE THROUGH THE REST OF THIS AFTERNOON
AND INTO TONIGHT...WITH PERHAPS ANOTHER ROUND OF PATCHY FOG AND
STRATUS AROUND SUNRISE THURSDAY. GIVEN THIS...WENT AHEAD WITH 5SM
VISIBILITY IN BR AND A CEILING AT 2000FT AGL 09-14Z THURSDAY. THE
SURFACE WIND WILL REMAIN FAIRLY LIGHT AND AT TIMES VARIABLE
THROUGH TONIGHT...THEN BECOMING MORE ESTABLISHED FROM THE
SOUTH/SOUTHEAST DURING THE DAY THURSDAY.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...BRYANT
LONG TERM...BRYANT
AVIATION...BRYANT
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
341 AM CDT WED AUG 5 2015
.SYNOPSIS...
ISSUED AT 303 AM CDT WED AUG 5 2015
LARGE HUDSON BAY CLOSED LOW SENDING A BROAD TROUGH INTO
THE EASTERN CONUS. RIDGING INTO THE CENTRAL CANADIAN PLAINS AND A
CLOSED LOW OVER BRITISH COLUMBIA WITH TROUGHING INTO NORTHERN
CALIFORNIA. UPPER HIGH CENTERED OVER THE DESERT SOUTHWEST. WEAK
UPPER WAVE MOVING ACROSS MISSOURI AND A WAVE ROUNDING THE RIDGE INTO
THE CENTRAL PLAINS OF CANADA.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 303 AM CDT WED AUG 5 2015
AREAS OF FOG DEVELOPING AGAIN THIS MORNING OVER WESTERN NEBRASKA.
VISIBILITIES ARE GENERALLY 3 TO 5 MILES BUT EXPECT THEY MAY DROP TO
1 TO 3 MILES. HAVE INCLUDED THROUGH 14Z THIS AM. PRECIPITATION
CHANCES HAVE ENDED THIS MORNING WITH NEAREST ECHOES OVER SOUTH
CENTRAL INTO SOUTHEAST NEBRASKA. HAVE REMOVED POPS THIS MORNING OVER
NORTH CENTRAL ZONES. ABUNDANT MOISTURE IN PLACE ACROSS WESTERN
NEBRASKA TODAY WITH TD`S IN THE MID 60S. NEXT DISTURBANCE ENTERING
WESTERN WYOMING THIS MORNING. SUN WILL BE OUT LATE THIS MORNING AND
WITH THAT TEMPERATURES EXPECTED TO REBOUND INTO THE LOW 80S. LATE
SHOW TONIGHT WITH NEXT DISTURBANCE MOVING INTO THE NORTHERN PLAINS
LATE THIS EVENING. 30 TO 40KT LOW LEVEL JET WILL MOVE OUT OF THE
PANHANDLE IN THE LATE EVENING AHEAD OF THE SURFACE TROUGH AXIS.
SHOULD BE ENOUGH LIFT TO START CONVECTION THAT WILL MOVE EAST
THROUGH THE EARLY MORNING HOURS. LOWS IN THE 60S WITH STRONG WARM
AIR ADVECTION.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 303 AM CDT WED AUG 5 2015
AFTER SCATTERED TSTMS DRIVEN BY SOUTHERLY LOW LEVEL JET THURSDAY
MORNING...ADDITIONAL DEVELOPMENT ALONG A COLD FRONT THURSDAY
AFTERNOON WILL BE THE FIRST CHALLENGE FOR THIS PERIOD. A POTENT
SHORTWAVE WILL CROSS THE DAKOTAS THURSDAY INTO THURSDAY NIGHT.
SURFACE LOW PRESSURE ASSOCIATED WITH THIS SYSTEM WILL TRACK FROM
CENTRAL SOUTH DAKOTA TO NORTHERN MINNESOTA. A TRAILING COLD FRONT
FROM THE LOW WILL MOVE SOUTHEAST ACROSS WESTERN INTO CENTRAL
NEBRASKA DURING THE DAY THURSDAY. THE NAM/SREF/ECMWF ALL IN GOOD
AGREEMENT ON THE TIMING OF THE FRONT...HAVE IT LOCATED FROM NEAR
EWING TO BROKEN BOW BY LATE AFTERNOON. IT WILL BECOME VERY
UNSTABLE ALONG AND AHEAD OF THE FRONT BY LATE AFTERNOON...WITH SFC
BASED CAPES OF 4000 TO 5000 J/KG. WIND SHEAR DECENT AS
WELL...WITH MID LEVEL WESTERLIES INCREASING TO NEAR 45 KTS WITH
THE PASSAGE OF THE TROUGH ALOFT. AT THE SAME TIME MID LEVEL
COOLING AND MODERATELY STRONG FORCING WILL BE TAKING PLACE. ALL
THESE FACTORS INDICATE TSTMS SHOULD DEVELOP ALONG THE FRONT BY
AROUND 4PM. SUPERCELLS LIKELY AT FIRST WITH STORMS BECOMING MORE
LINEAR AS THEY MOVE EAST INTO EASTERN NEBRASKA. THE SPEED OF THE
FRONT WILL BE KEY...IF A FASTER GFS SOLUTION VERIFIES ALL THE
ACTIVITY COULD BE JUST EAST OF THE AREA. AT THIS POINT
THOUGH...WITH MOST OTHER MODELS SLOWER...CONFIDENCE FAIRLY HIGH
THAT THE FRONT WILL BE IN OUR AREA OF CONCERN DURING STORM
INITIATION. IF THE FRONT WOULD HAPPEN TO SLOW FURTHER...THEN MORE
OF THE FORECAST AREA WOULD BE AT RISK FOR STORMS. WILL CONTINUE TO
MONITOR.
THE NEXT IN A SERIES OF SHORTWAVES ALOFT CROSSES THE REGION FRIDAY
NIGHT. NAM/GFS/ECMWF ALL HAVE A DECENT HANDLE ON THIS...AND LIKELY
POPS HAVE BEEN INTRODUCED FRIDAY NIGHT. APPEARS STORMS WILL
DEVELOP ACROSS WESTERN NEBRASKA TOWARD EVENING...WITH AN MCS
LIKELY TO ORGANIZE AS THE STORMS MOVE EAST DUE TO AMPLE SHEAR AND
INSTABILITY. WILL HAVE TO WATCH THIS...AS SEVERAL AREAS HAVE HAD
THREE TO FOUR INCHES OF RAIN THE LAST COUPLE OF DAYS...AND LOCAL
FLOODING IS POSSIBLE IF HEAVY RAIN MATERIALIZES.
SATURDAY INTO THE FIRST OF NEXT WEEK...THE OVERALL UPPER PATTERN
REMAINS LARGELY UNCHANGED. THE LARGE UPPER LEVEL RIDGE OF HIGH
PRESSURE WILL REMAIN ANCHORED ACROSS THE SOUTHERN PLAINS...WITH
PERIODIC UPPER WAVES ROTATING EAST ACROSS OUR AREA ON THE NORTHERN
PERIPHERY OF THE UPPER HIGH. THIS WILL CONTINUE THE THREAT OF AT
LEAST A SLIGHT CHANCE FOR TSTMS DAILY...WITH NEAR NORMAL
TEMPERATURES CONTINUING.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1125 PM CDT TUE AUG 4 2015
THE SREF...NAM...RAP AND HRRR MODELS CONTINUE TO SUGGEST IFR/MVFR
CIGS AND VSBY DEVELOPING OVERNIGHT LASTING UNTIL 15Z-17Z
WEDNESDAY. VFR IS EXPECTED 18Z-06Z WEDNESDAY EVENING.
THE MODELS SUGGEST TSTM ACTIVITY COULD COMMENCE IN THE PANHANDLE
AROUND 21Z...GENERALLY ISOLATED THOUGH. A BETTER OPPORTUNITITY MAY
DEVELOP 03Z-06Z WITH A DISTURBANCE MOVING INTO WRN NEB. SCATTERED
COVERAGE IS POSSIBLE BY 06Z WEDNESDAY NIGHT.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...POWER
SHORT TERM...POWER
LONG TERM...TAYLOR
AVIATION...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1125 PM CDT TUE AUG 4 2015
.SYNOPSIS...
ISSUED AT 359 PM CDT TUE AUG 4 2015
AT 20Z THE SYNOPTIC PATTERN WAS HIGHLIGHTED BY UPPER LEVEL LOWS
CENTERED OVER JAMES BAY IN SOUTHEAST CANADA AND ALONG WEST COAST
OF BRITISH COLUMBIA. AN UPPER LEVEL RIDGE WAS ESTABLISHED IN
BETWEEN THESE TWO FEATURES. A ROBUST MID-LEVEL SHORTWAVE SLOWLY
TRACKING BENEATH THE RIDGE THROUGH CENTRAL WYOMING HAS BEEN THE
MAIN PLAYER IMPACTING THE SENSIBLE WEATHER OVER THE CWA FOR MUCH
OF THE DAY. AT THE SURFACE...AN AREA OF LOW PRESSURE WAS CENTERED
IN THE EASTERN NEBRASKA PANHANDLE...WITH A DRYLINE EXTENDING
SOUTH INTO EASTERN CO...A STATIONARY TROUGH EXTENDING NORTHWARD
TOWARD THE BLACK HILLS...AND A WARM FRONT DRAPED SOUTHEAST ACROSS
FAR SOUTHWEST NEB INTO NORTHERN KANSAS. NORTH OF THE WARM FRONT
SURFACE WINDS HAVE HAD AN EASTERLY UPSLOPE COMPONENT FOR MOST OF
THE DAY...ADVECTING RICH LOW LEVEL MOISTURE INTO WESTERN NEBRASKA
WITH DEWPOINTS IN THE MID TO UPPER 60S. SHOWER AND THUNDERSTORM
ACTIVITY HAS BEEN ONGOING NORTH OF THE FRONT FOR MUCH OF THE
DAY...MAINLY IN SOUTHWEST NEBRASKA.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 359 PM CDT TUE AUG 4 2015
DEEP CONVECTION AND CLOUD COVER THROUGH THE DAY HAS MUDDLED THE
FORECAST PICTURE. HI-RES MODELS THIS MORNING ADVERTISED A
NORTHERLY PROGRESSION OF THE WARM FRONT TOWARD I-80. HOWEVER
CLOUD COVER AND COLD OUTFLOW FROM PERSISTENT THUNDERSTORM
ACTIVITY IN SOUTHWEST NEBRASKA HAS HAMPERED THIS NORTHWARD
ADVANCEMENT OF THE FRONT...AND IT HAS REMAINED STALLED NEAR THE
KANSAS BORDER FOR MOST OF THE DAY. THIS WILL KEEP THE BEST
INSTABILITY AND THE MAIN THREAT AREA FOR SEVERE WEATHER GENERALLY
SOUTH OF THE CWA THROUGH THE REMAINDER OF THE AFTERNOON AND
EVENING. WARM AIR ADVECTION ASSOCIATED WITH A STRONG LOW VEERING
WIND PROFILE NORTH OF THE SURFACE WARM FRONT WILL KEEP SCATTERED
TO WIDESPREAD THUNDERSTORM CHANCES GOING ACROSS THE CWA INTO THE
EVENING HOURS...WITH THE BEST CHANCES FROM SOUTHWEST INTO CENTRAL
NEBRASKA. ADDITIONAL DEVELOPMENT IS POSSIBLE LATER THIS AFTERNOON
IN THE VICINITY OF AN OUTFLOW BOUNDARY STALLED OVER NORTH CENTRAL
NEBRASKA WHERE MESOANALYSIS INDICATES INCREASING MOISTURE LOW
LEVEL CONVERGENCE...WITH THE HRRR MODEL RECENTLY PICKING UP ON
THIS IDEA AS WELL. STEERING FLOW ALOFT IS RATHER WEAK...SO SLOW
STORM MOTIONS WILL PROMOTE A THREAT FOR LOCALLY HEAVY RAINFALL
GIVEN PWATS AOA 1.5".
PRECIP CHANCES BEGIN TO END FROM WEST TO EAST OVERNIGHT AS MID-
LEVEL SHORTWAVE TROUGH SLOWLY KICKS EAST AND THE INSTABILITY
WANES WITH THE WEAKENING WAA REGIME JUST OFF THE SURFACE. LOW
LEVEL MOISTURE HANGS AROUND AS MAIN AREA OF LOW PRESSURE REMAINS
JUST OFF TO OUR WEST...WHICH KEEP LIGHT SOUTHEASTERLY WINDS AND
DEWPOINTS IN THE MID TO UPPER 60S IN PLACE. BOTH THE NAM/GFS SHOW
THE DEVELOPMENT OF FOG/STRATUS IN SOUTHWEST NEBRASKA LATE IN THE
OVERNIGHT INTO WEDNESDAY MORNING. POPS PUSH EAST OF THE AREA BY
NOON WEDNESDAY AND CLEARING SKIES PROGRESS EASTWARD. THIS WILL
LEAD TO HIGH TEMPERATURES RANGING FROM THE MID 80S IN NORTH
CENTRAL NEBRASKA WHERE SOME CLOUD COVER WILL HANG AROUND INTO THE
AFTERNOON HOURS...TO THE LOW 90S IN SOUTHWEST NEBRASKA WHERE MORE
SUNSHINE IS EXPECTED. LATEST NAM/EC GUIDANCE HAVE TRENDED COOLER
FOR TOMORROW AND KEEPS MORE CLOUD COVER AROUND...SO THIS TREND
WILL NEED TO MONITORED INTO TONIGHT. HAVE BEEN HESITANT TO MAKE
LARGE ADJUSTMENTS TO THE FORECAST GIVEN THE AMOUNT OF CONVECTION
THAT NEEDS TO PLAY OUT IN THE NEAR TERM.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 359 PM CDT TUE AUG 4 2015
A TROUGH WILL MOVE ACROSS SOUTHWESTERN CANADA WED NIGHT AND
SUPPRESS THE RIDGE TO THE SOUTHERN ROCKIES. AS A RESULT THE FLOW
ACROSS THE HIGH PLAINS WILL BECOME MORE ZONAL. THE TROUGH MOVES
ACROSS SOUTH CENTRAL CANADA TO END THE WEEK. AS THE TROUGH SLIDES
EAST THE SOUTHERN RIDGE WILL BUILD SLIGHTLY INTO THE CENTRAL
ROCKIES. OVER THE WEEKEND INTO NEXT WEEK AN UPPER LEVEL LOW WILL
SLOWLY PUSH TOWARDS THE PACIFIC NORTHWEST. THIS WILL CAUSE THE
RIDGE TO AMPLIFLY OVER THE ROCKIES.
LITTLE CHANGE TO THE ACTIVE WEATHER PATTERN. AS WE SHIFT FROM
NORTHWEST FLOW TO MORE ZONAL AND BACK...THE TRAIN OF SHORT WAVES
WILL CONTINUE TO PUSH ACROSS THE PLAINS. THUS THE FORECAST WILL
CONTINUE TO HAVE POPS IN NEARLY EVERY PERIOD...HOWEVER DO NOT
EXPECT A WASH OF A FORECAST. AS THE WAVES MOVE ACROSS A CHANCE FOR
STORMS WILL EXIST...ESPECIALLY FOR THE AFTERNOON NOON INTO THE
LATE EVENING HOURS.
AS FOR TEMPERATURES...SEASONAL IS THE BEST WAY TO EXPLAIN. IF
SHOWERS ARE OCCURING DURING THE PEAK HEAT...TEMPS MAY HOLD IN THE
LOWER TO MID 80S...OTHERWISE MID 80S TO LOWER 90S WILL BE COMMON.
LOWS GENERALLY IN THE 60S WITH A FEW LOCALLY COMMON COOL SPOTS TO
SEE A FEW LOWS DIP INTO THE UPPER 50S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1125 PM CDT TUE AUG 4 2015
THE SREF...NAM...RAP AND HRRR MODELS CONTINUE TO SUGGEST IFR/MVFR
CIGS AND VSBY DEVELOPING OVERNIGHT LASTING UNTIL 15Z-17Z
WEDNESDAY. VFR IS EXPECTED 18Z-06Z WEDNESDAY EVENING.
THE MODELS SUGGEST TSTM ACTIVITY COULD COMMENCE IN THE PANHANDLE
AROUND 21Z...GENERALLY ISOLATED THOUGH. A BETTER OPPORTUNITITY MAY
DEVELOP 03Z-06Z WITH A DISTURBANCE MOVING INTO WRN NEB. SCATTERED
COVERAGE IS POSSIBLE BY 06Z WEDNESDAY NIGHT.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MARTIN
SHORT TERM...MARTIN
LONG TERM...MASEK
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
431 PM PDT THU AUG 6 2015
.SYNOPSIS...MONSOON MOISTURE CREEPING INTO THE AREA WILL BRING
INCREASED CHANCES FOR SHOWERS AND THUNDERSTORMS TO THE REGION TODAY.
THUNDERSTORM ACTIVITY WILL DECREASE RAPIDLY FROM WEST TO EAST FRIDAY
AS DRIER AIR PUSHES INTO THE REGION FOR THE WEEKEND. ANOTHER ROUND
OF MOISTURE MAY BE ON TAP FOR THE MIDDLE OF NEXT WEEK.
&&
.UPDATE...I DID A QUICK UPDATE TO TWEAK POPS BASED ON RADAR TRENDS
WHERE WE ARE SEEING SHOWERS AND THUNDERSTORMS. DRY LOW-LEVELS ARE
RESULTING IN SPRINKLES TO VERY LIGHT RAIN TOTALS SO FAR BUT STORMS
WITH SURPRISINGLY WEAK RETURNS ON 0.5 DEGREE RADAR REFLECTIVITY FROM
BOTH KEYX AND KESX. DCAPE VALUES ARE SHOWING A TIGHT GRADIENT OVER
WESTERN CLARK AND WESTERN/CENTRAL SAN BERNARDINO COUNTIES SO THE
NORTHWEST PART OF THE AREA WILL SEE LITTLE THREAT FOR GUSTY WINDS.
HOWEVER FROM A MERCURY/DESERT ROCK TO AMBOY TO LAKE HAVASU LINE ON
EAST, GUSTS OF 30-50 MPH OR GREATER ARE POSSIBLE. THUS THE AREA OF
GUSTY WINDS WAS INCREASED IN THE WORDED FORECAST AS A THUNDERSTORM
HAZARD. STORMS SHOULD STILL TRANSITION TO A WETTER TYPE TONIGHT AS
LOWER LEVEL MOISTURE INCREASES.
&&
.PREVIOUS DISCUSSION...
ISSUED AT 205 PM PDT THU AUG 6 2015
.SHORT TERM...TODAY THROUGH FRIDAY NIGHT.
CONVECTION THUS FAR THIS AFTERNOON HAS BEEN CONFINED TO MAINLY
WESTERN SAN BERNARDINO COUNTY WHERE SOME MID LEVEL INSTABILITY IS
FUELING FAST MOVING STORMS ALONG THE LEADING EDGE OF A STRONG UPPER
LEVEL JET. SUB-CLOUD LAYERS IN THIS AREA ARE QUITE DRY WITH SURFACE
DEWPOINTS MAINLY IN THE 30S...SO GUSTY DOWNBURST WINDS ARE A CONCERN
BUT STORMS WILL STRUGGLE TO PRODUCE ANY MEASURABLE RAINFALL. WHILE
THE STORMS HAVE STRUGGLED TO DEPOSIT RAINFALL....THEY HAVE BEEN VERY
EFFICIENT LIGHTNING PRODUCERS WITH OVER 250 CLOUD TO GROUND
LIGHTNING STRIKES SINCE THE NOON HOUR IN WESTERN SAN BERNARDINO
COUNTY. WITH THIS ACTIVITY MOVING NORTHWARD...A RED FLAG WARNING HAS
BEEN POSTED FOR DRY LIGHTNING FOR MUCH OF SAN BERNARDINO COUNTY AND
THE EASTERN HALF OF INYO COUNTY THROUGH LATE TONIGHT.
STILL EXPECTING ATTENTION TO SHIFT FURTHER EAST THIS AFTERNOON AS
MORE ROBUST CONVECTION DEVELOPS ACROSS THE LOWER COLORADO RIVER
VALLEY. CURRENT MESOANALYSIS SHOWS SURFACE BASED INSTABILITY
BUILDING ACROSS THIS AREA WITH CAPE VALUES EXCEEDING 1000 J/KG WITH
LIMITED CAPPING. SEVERAL CONSECUTIVE HRRR RUNS HAVE INSISTED ON
BREAKING THIS AREA OUT IN THE NEXT FEW HOURS. THE POTENTIAL FOR
STRONG AND POTENTIALLY DAMAGING DOWNBURST WINDS IS QUITE HIGH ALONG
THE COLORADO RIVER ROUGHLY FROM BULLHEAD CITY SOUTHWARD TO LAKE
HAVASU...SO THIS AREA WILL BE WATCHED CLOSELY FOR THE POSSIBILITY OF
SEVERE STORMS.
TONIGHT...ACTIVITY ACROSS MOHAVE AND EASTERN SAN BERNARDINO COUNTIES
WILL DRIFT NORTHWARD INTO SOUTHERN NEVADA WHILE ADDITIONAL ACTIVITY
IS LIKELY TO BREAK OUT ACROSS OUR SOUTHERN GREAT BASIN ZONES. WITH
INCREASING SOUTHWESTERLY SHEAR AS A PACIFIC TROUGH APPROACHES...A
FEW BANDS OF PERSISTENT CONVECTION MAY DEVELOP OVERNIGHT WHICH WILL
BE OUR PRIMARY CONCERN FOR ANY FLASH FLOODING. INDIVIDUAL STORM
MOTION WILL BE RATHER SWIFT...BUT TRAINING STORMS WILL POSE A FLOOD
RISK WITH THE HIGH PRECIPITABLE WATER IN PLACE...SO MAINTAINED THE
FLASH FLOOD WATCH TO ACCOUNT FOR THIS FOR MOHAVE AND LINCOLN
COUNTIES. STRONG AND POTENTIALLY DAMAGING WINDS WILL REMAIN
POSSIBLE OVERNIGHT DUE TO STRENGTHENING DEEP LAYER WIND SHEAR AS
WELL AS THE POSSIBILITY OF HAIL WITH THE STRONGER STORMS.
FRIDAY...PACIFIC TROUGH WILL SWEEP EASTWARD ON FRIDAY DRAGGING THE
DEEPER MOISTURE AND INSTABILITY WITH IT. ANTICIPATE ONGOING
CONVECTION AND CLOUD COVER TO BE CONFINED MAINLY TO SOUTHERN NEVADA
AND NORTHWEST ARIZONA IN THE MORNING WHILE SHIFTING EASTWARD THROUGH
THE DAY. BY 5 PM...ANY REMAINING THUNDERSTORM ACTIVITY WILL BE
PRIMARILY CONFINED TO EASTERN MOHAVE COUNTY AND FAR EASTERN AND
NORTHERN LINCOLN COUNTIES. FLASH FLOODING WILL REMAIN A CONCERN WITH
TRAINING STORMS...BUT THE THREAT WILL BE TRANSLATING EASTWARD
THROUGH THE DAY. WITH STRONG SHEAR IN PLACE...SEVERE STORMS WILL BE
A POSSIBILITY AS WELL DEPENDING ON THE DEGREE OF CLOUD COVER AND HOW
MUCH IT INHIBITS DAYTIME HEATING. BY FRIDAY EVENING MOSTLY DRY AND
CLEAR CONDITIONS WILL OVERSPREAD THE ENTIRE REGION.
.LONG TERM...SATURDAY THROUGH THURSDAY.
A DRY SOUTHWEST FLOW WILL BE OVER THE ENTIRE FORECAST AREA SATURDAY
THROUGH MONDAY. HIGH PRESSURE OVER TEXAS WILL EXPAND WEST TOWARD NEW
MEXICO WHILE A TROUGH OF LOW PRESSURE STRETCHES GENERALLY NORTH-
SOUTH ALONG THE WEST COAST STARTING LATE MONDAY. THIS COMBINATION
WILL ALLOW SOUTHERLY FLOW TO DEVELOP WITH MOISTURE TRACKING
NORTHWARD MAINLY INTO MOHAVE COUNTY. WILL CONTINUE THE SHOWER AND
THUNDERSTORM CHANCES FOR THIS AREA TUESDAY. SOUTHERLY FLOW APPEARS
TO STICK AROUND THROUGH THURSDAY, WITH MOISTURE SLIGHTLY EDGING WEST
WEDNESDAY AND PERHAPS LINGERING INTO THURSDAY. THERE REMAINS
UNCERTAINTY IN JUST HOW MUCH MOISTURE WILL ARRIVE AND HOW FAR WEST
IT MAY TRACK. OTHERWISE NEAR NORMAL TEMPS ARE EXPECTED THROUGHOUT
THE LONG-TERM PERIOD. BREEZY SOUTH TO SOUTHWEST WINDS WILL BE COMMON
EACH AFTERNOON AND EARLY EVENING.
&&
.AVIATION...FOR MCCARRAN...SOUTH TO SOUTHWEST WINDS IN THE 9-12KT
RANGE WITH GUSTS TO 20KTS EXPECTED THROUGH THE EVENING. SHOWERS AND
THUNDERSTORMS EXPECTED TO BREAK OUT SOMETIME BETWEEN 01Z-05Z AND
CONTINUING MUCH OF NIGHT. BIGGEST CONCERN WILL BE GUSTY AND ERRATIC
OUTFLOW WINDS...WHICH COULD EXCEED 35KTS IF ANY ROBUST STORMS
DEVELOP IN THE VALLEY. OTHERWISE...CIGS IN THE 9-12K RANGE WITH
DISRUPTIONS TO APPROACH CORRIDORS LIKELY AT TIMES. SHOWERS AND
THUNDERSTORMS REMAIN POSSIBLE THROUGH 21Z FRIDAY BEFORE IMPROVING
CONDITIONS MOVE IN WITH DECREASING CLOUD COVER. SOUTHWEST WINDS OF
10-15KTS WITH GUSTS TO 25KTS EXPECTED FRIDAY AFTERNOON.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...ISOLATED TO SCATTERED SHRA/TSRA POSSIBLE BEFORE
00Z...PRIMARILY SOUTH OF THE INTERSTATE 15 CORRIDOR. PRECIPITATION
CHANCES WILL SPREAD NORTH INTO THE SOUTHERN GREAT BASIN THIS
EVENING...THEN END RAPIDLY FROM WEST TO EAST THROUGH THE DAY FRIDAY.
STORMS WILL HAVE THE POTENTIAL TO PRODUCE ERRATIC WIND GUSTS IN
EXCESS OF 45 KTS. CIGS ARE GENERALLY EXPECTED TO REMAIN AOA 10K FEET
EXCEPT NEAR SHRA/TSRA WHERE THEY COULD LOWER TO 6-8K FEET. GUSTY
WINDS OF 15-20KTS WITH GUSTS TO 30KTS EXPECTED FRIDAY AFTERNOON
ACROSS THE WESTERN MOJAVE DESERT AND SOUTHERN GREAT BASIN.
&&
.FIRE WEATHER...THUNDERSTORMS HAVE DEVELOPED ACROSS NORTHWESTERN SAN
BERNARDINO AND SOUTHERN INYO COUNTY, HOWEVER, WITH DRY LOW-LEVELS,
VERY LITTLE PRECIPITATION WAS REACHING THE GROUND AND AREA RADARS
SHOWED WEAK TO NO RETURNS ON THE LOWEST ELEVATION SCANS. THUS, THIS
HAS CREATED A SIGNIFICANT POTENTIAL FOR DRY LIGHTNING IN NORTHWEST
SAN BERNARDINO COUNTY AND DEATH VALLEY NATIONAL PARK THIS AFTERNOON
INTO TONIGHT. A RED FLAG WARNING WAS ISSUED FOR DRY LIGHTNING FOR
CALIFORNIA ZONES 227 AND 228 AS A RESULT. WE WILL NEED TO KEEP AN
EYE ON THE REST OF INYO, ESMERALDA, SOUTHERN AND CENTRAL NYE AS WELL
AS WESTERN CLARK AS A SMALL RISK FOR DRY LIGHTNING ALSO EXISTS IN
THESE AREAS THROUGH TONIGHT, HOWEVER, CONFIDENCE IS NOT HIGH ENOUGH
TO ISSUE ANY HEADLINES. HOWEVER, BASED ON THE GENERAL TRENDS THE
THREAT INTO ESMERALDA AND NORTHWESTERN INYO COUNTY LOOKS VERY LOW
AND THAT MOST ACTIVITY THERE SHOULD BE JUST SHOWERS. ACROSS MOHAVE,
LINCOLN AND MOST OF CLARK COUNTIES STORMS ARE EXPECTED TO GENERALLY
BE WET IN NATURE DUE TO THE HIGH MOISTURE CONTENT OF THE ATMOSPHERE.
AS DRIER AIR SWEEPS IN FROM THE SOUTHWEST THURSDAY NIGHT INTO
FRIDAY, THIS WILL HELP TO END THE POTENTIAL FOR SHOWERS AND
THUNDERSTORMS FROM WEST TO EAST. HOWEVER, THIS WILL ALSO HELP TO
INCREASE WINDS FROM THE SOUTH TO SOUTHWEST. RELATIVE HUMIDITY VALUES
AT OR BELOW 15 PERCENT, WIND GUSTS OF 35 MPH OR GREATER AS WELL AS
FUELS BEING DRIED OUT ENOUGH LOOK TO BE MET IN NEVADA ZONE 462 AND
THE FIRE WEATHER WATCH WAS UPGRADED TO A RED FLAG WARNING HERE.
ELSEWHERE, ONLY ONE OR TWO OF THESE CRITERIA LOOK TO BE MET SO NO
HEADLINES WERE ISSUED.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTERS ARE ENCOURAGED TO REPORT
ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING
PROCEDURES.
&&
$$
UPDATE...STACHELSKI
SHORT TERM/AVIATION...OUTLER
LONG TERM...PADDOCK
FIRE WEATHER...STACHELSKI
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1035 AM EDT WED AUG 5 2015
.SYNOPSIS...
SHOWERS WITH EMBEDDED THUNDERSTORMS WILL BE POSSIBLE
AGAIN TODAY WITH TEMPERATURES MAINLY IN THE 70S. A SLOW DRYING TREND
WILL OCCUR ON THURSDAY AND CONTINUE INTO THE WEEKEND AS SURFACE HIGH
PRESSURE BUILDS INTO THE NORTH COUNTRY. TEMPERATURES WILL FEATURE
COOL NIGHTS AND MILD DAYS WITH VALUES VERY CLOSE TO NORMAL FOR THIS
TIME OF YEAR.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1031 AM EDT WEDNESDAY...MINOR UPDATE TO BRING TEMPERATURES
IN LINE WITH OBSERVED AND BLEND OUT SHORT TERM GUIDANCE. TEMPS
HAVE BEEN TRENDING A LITTLE ABOVE FORECAST AND BUMPED UP MAX TEMPS
A DEGREE OR TWO WITH THIS UPDATE. RADAR LOOP SHOWING SCATTERED
SHOWERS DEVELOPING OVER NORTHERN VERMONT ALONG THE BORDER, AND
SCATTERED POPS IN THE PRESENT FORECAST HAVE THIS COVERED WELL SO
NO CHANGES NEEDED THERE.
DEEP MID/UPPER LEVEL TROUGH ACROSS THE NORTHEAST US WITH NUMEROUS
EMBEDDED 500 MB VORTICITY MAXS. WATER VAPOR SHOWS BEST DEEP LAYER
MOISTURE HAS SHIFTED INTO THE MID ATLANTIC STATES WITH TROUGH AXIS
DIRECTLY OVERHEAD. THIS WILL RESULT IN COOL POOL ALOFT WITH 500
TEMPS NEAR -18C TODAY...WHICH WILL HELP TO STEEPEN LAPSE RATES AND
CREATE SOME INSTABILITY. HOWEVER...SOUNDINGS SHOW LESS INSTABILITY
THAN YESTERDAY FROM COOLER SURFACE TEMPS AND DRIER DEWPOINTS...IN
ADDITION PRECIPITABLE WATER VALUES ARE LESS TODAY. THESE FACTORS
ALL SUPPORT LESS AREAL COVERAGE OF CONVECTION TODAY AND WEAKER
UPDRAFTS WITH LESS ORGANIZATION. WE WILL MENTION CHANCE POPS WITH
GREATEST COVERAGE FROM THE NORTHERN DACKS INTO CENTRAL/NORTHERN VT
THIS AFTERNOON...ALONG WITH ISOLATED THUNDER. GIVEN LOW WET BULB
FREEZING LEVELS BETWEEN 7000 AND 8000 FEET SOME PEA SIZE HAIL
WILL BE POSSIBLE IN THE STRONGEST CELLS...BUT NOT WIDESPREAD IN
COVERAGE. QPF VALUES WILL GENERAL BE LESS 0.10" BUT LOCALIZED
HIGHER IN THE STRONGEST STORMS. PROGGED 850 MB TEMPS BETWEEN
8-10C SUPPORT HIGHS MAINLY IN THE UPPER 60S TO LOWER 70S IN THE
MOUNTAIN TOWNS TO MID TO UPPER 70S WARMER VALLEY LOCATIONS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
AS OF 345 AM EDT WEDNESDAY...LITTLE OVERALL CHANGE TO LARGE
SCALE SYNOPTIC PATTERN IS EXPECTED THROUGH FRIDAY WITH GENERAL
MID/UPPER LVL TROF ACROSS THE NE CONUS. HOWEVER...BEST DEEP LAYER
MOISTURE WILL BE SUPPRESSED TO OUR SOUTH DURING THE PERIOD WITH MUCH
LESS AREAL COVERAGE OF SHOWER ACTIVITY EXPECT ON THURS. SFC HIGH
PRES LOCATED OVER HUDSON BAY IS PROGGED TO NOSE INTO NORTHERN NY
DURING THIS PERIOD...RESULTING IN DRIER WX WITH LARGE DAILY SWINGS
IN TEMPS. LATEST TRENDS IN GUIDANCE HAS BEEN FOR COASTAL SYSTEM TO
PASS WELL SOUTH OF OUR CWA WITH GREATEST IMPACTS ACROSS THE SE CONUS
INTO THE MID ATLANTIC STATES. NW FLOW ALOFT COMBINED WITH WEAK 5H
VORT AND COOL POOL ALOFT WILL PRODUCE SPOTTY MAINLY DAYTIME HEAT
DRIVEN SHOWERS ACROSS THE DACKS INTO THE MTNS OF CENTRAL AND
NORTHERN VT ON THURS. WL MENTION SCHC IN THE CPV AND CHC POPS IN THE
MTNS WITH QPF VALUES GENERALLY < 0.10.
PROGGED 85H TEMPS COOL ANOTHER DEGREE OR TWO AND SUPPORT
MID/UPPER 60S MTNS TO NEK AND MID 70S WARMER VALLEYS...SEVERAL
DEGREES BELOW NORMAL FOR EARLY AUGUST. LITTLE CHANGE ANTICIPATED
ON FRIDAY WITH GENERAL NW FLOW ALOFT AND BUILDING SFC HIGH PRES.
WILL MENTION SCHC POPS IN THE MTNS AND KEEP REST OF FCST DRY ATTM.
PROGGED 85H TEMPS BTWN 8-10C SUPPORT HIGHS MAINLY IN THE 60S MTNS
TO 70S VALLEYS. LOWS WILL GENERALLY BE IN THE 40S COLDER MTN
VALLEYS TO 50S IN THE WIDER CHAMPLAIN AND SAINT LAWRENCE VALLEYS
THRU THE PERIOD.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 331 AM EDT WEDNESDAY...MID-LEVEL CYCLONIC FLOW/LONGWAVE
TROUGHING PREVAILS IN THE MEAN ACROSS THE NORTH COUNTRY DURING THE
EXTENDED. ALL-IN-ALL, A GENERALLY UNEVENTFUL PERIOD OF WEATHER
INTO THE EARLY PART OF THE WEEKEND, WITH BETTER CHANCES FOR
PRECIPITATION HOLDING OFF UNTIL SUNDAY AND EARLY NEXT WEEK.
FORECAST FOLLOWS BLENDED GUIDANCE UNLESS NOTED OTHERWISE.
EARLIER CYCLES OF GLOBAL GUIDANCE SUITE HAD INDICATED A POTENTIAL
COASTAL LOW DEVELOPING OFF THE MID-ATLANTIC COAST LATER FRIDAY AND
ITS PRECIPITATION SHIELD EXPANDING INTO EASTERN SECTIONS OF
VERMONT ON SATURDAY. WHILE RECENT GUIDANCE STILL SHOWS THIS
SYSTEM, A NOTED TREND HAS BEEN TO A POSITION FURTHER OFF THE COAST
RESULTING IN A MORE OPTIMISTIC EARLY-WEEKEND FORECAST. SO THE
BIGGEST CHANGE TO THE INHERITED FORECAST WAS TO LOWER POPS FOR THE
SATURDAY/SATURDAY NIGHT PERIOD FOR VERMONT. I DIDN`T WANT TO
COMPLETELY GO DRY ON THE CHANCE THAT A WESTWARD RECURVE REVEALS
ITSELF IN SUBSEQUENT GUIDANCE RUNS, BUT I`VE LOWERED DOWN TO
SLIGHT CHANCE.
00Z GFS/EC SOLUTIONS START TO DIFFER AFTER SUNDAY ON SENSIBLE
WEATHER DETAILS. WHILE BOTH GLOBAL SOLUTIONS DEPICT A 1000-500 MB
THICKNESS GRADIENT/WARM FRONT ACROSS THE NORTH COUNTRY AND RATHER
WEAK LOBES OF VORT MAXIMA ACTING ON THE BOUNDARY, THE GFS SHOWS
HARDLY ANY PRECIPITATION AT ALL. THAT`S A STRANGE/UNREALISTIC
RESULT. I`VE THEREFORE HEDGED CLOSER TO THE WETTER ECMWF IN
KEEPING CHANCE POPS GOING SUNDAY. CHANCE POPS CONTINUE INTO EARLY
NEXT WEEK AS THE BAROCLINIC ZONE MAKES LITTLE EASTWARD OR
NORTHWARD INROADS AND MAY SERVE AS A CONDUIT FOR CONTINUED RAIN
CHANCES. THERE IS SOME LIMITED INSTABILITY (LIFTED INDICES OF -1
TO -2), SO OPTED FOR SHOWERS/THUNDERSTORMS EACH DAY.
TEMPS THROUGH THE PERIOD ARE CLOSE TO NEAR EARLY-/MID-AUGUST
NORMALS WITH HIGHS IN THE 70S AND LOWS IN THE 50S/NEAR 60.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
THROUGH 12Z THURSDAY...VFR OUTSIDE OF DEVELOPING SCT
SHOWERS/STORMS WITH BRIEFLY REDUCED VISBILITIES AS LOW AS IFR.
POTENTIAL FOR IFR/LIFR FOG AT MPV AND SLK INTO THE OVERNIGHT.
INFRARED SATELLITE SHOWS SCT-BKN CLOUDS EXTENDING FROM NORTHEAST
CORNER OF VT BACK THROUGH THE ADIRONDACKS AHEAD OF SFC TROUGH OVER
SOUTHERN QUEBEC. THESE SHOULD THIN OUT INTO THE MORNING HOURS.
HOWEVER WITH A COLD POOL ALOFT ASSOCIATED WITH DEEP UPPER LOW,
SCT SHOWERS/STORMS WILL DEVELOP WITH DAYTIME HEATING. ANY STRONG
STORM THAT DEVELOPS WILL BE CAPABLE OF BRIEF IFR-VISIBILITY
DOWNPOURS, SMALL HAIL AND GUSTY OUTFLOW PRODUCING LOCALIZED
TURBULENCE. OVERALL COVERAGE OF STRONG STORMS WILL BE LIMITED.
BASED ON HRRR AND RECENT BTV WRF GUIDANCE, SHOWERS/STORMS MOST
FAVORED FOR ALL TERMINALS EXCEPT RUT AND STARTING AROUND 17Z WITH
6SM SHRA. DAYTIME WINDS WEST TO WEST/SOUTHWEST 6-10 KTS GUSTS
UNDER 20 KTS.
ANY SHOWERS/STORMS QUICKLY DISSIPATE NEAR/AFTER SUNSET. RISK OF
IFR/LIFR FOG AT SLK AND MPV IS CONDITIONAL ON CLEARING, WHICH
ISN`T CERTAIN. I`VE OPTED TO LEAVE OUT FOR NOW. WINDS SHOULD
BECOME LIGHT NORTHWEST (VARIABLE AT TIMES) THIS EVENING.
OUTLOOK 12Z THURSDAY THROUGH SUNDAY...
12Z THURSDAY - 00Z FRIDAY...MAINLY VFR WITH SPOTTY DIURNALLY-DRIVEN
SHOWERS.
00Z FRIDAY ONWARD...DAYTIME VFR WITH EVENING IFR/LIFR FOG AT MPV
AND SLK TERMINALS.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TABER
NEAR TERM...HANSON
SHORT TERM...TABER
LONG TERM...LOCONTO
AVIATION...LOCONTO
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
721 AM EDT WED AUG 5 2015
.SYNOPSIS...
SHOWERS WITH EMBEDDED THUNDERSTORMS WILL BE POSSIBLE
AGAIN TODAY WITH TEMPERATURES MAINLY IN THE 70S. A SLOW DRYING TREND
WILL OCCUR ON THURSDAY AND CONTINUE INTO THE WEEKEND AS SURFACE HIGH
PRESSURE BUILDS INTO THE NORTH COUNTRY. TEMPERATURES WILL FEATURE
COOL NIGHTS AND MILD DAYS WITH VALUES VERY CLOSE TO NORMAL FOR THIS
TIME OF YEAR.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 719 AM EDT WEDNESDAY...MINOR UPDATE TO REDUCE POPS ACROSS
MOST OF VT AND NORTHERN NEW YORK THIS MORNING. CRNT RADAR SHOWS
ONLY A FEW VERY LIGHT RAIN SHOWERS ACROSS THE NORTHEAST
KINGDOM...WHICH WILL EXIT OUR CWA BY 12Z. OTHERWISE...EXPECTING A
MAINLY DRY FCST THROUGH THIS MORNING...BEFORE ADDITIONAL SHOWERS
WITH EMBEDDED STORMS DEVELOP THIS AFTN FROM SFC HEATING/WEAK
INSTABILITY. SKIES WILL BE PARTLY TO MOSTLY CLOUDY WITH HIGHS
MAINLY IN THE 60S MTNS TO 70S VALLEYS TODAY.
LARGE SCALE SHOWS DEEP MID/UPPER LEVEL TROF ACROSS THE NE CONUS
WITH NUMEROUS EMBEDDED 5H VORTS. WATER VAPOR SHOWS BEST DEEP LAYER
MOISTURE HAS SHIFTED INTO THE MID ATLANTIC STATES WITH TROF AXIS
DIRECTLY OVERHEAD. THIS WILL RESULT IN COOL POOL ALOFT WITH 500
TEMPS NEAR -18C TODAY...WHICH WILL HELP TO STEEPEN LAPSE RATES AND
CREATE SOME INSTABILITY. HOWEVER...SOUNDINGS SHOW LESS INSTABILITY
THAN YESTERDAY FROM COOLER SFC TEMPS AND DRIER DWPTS...IN ADDITION
PW VALUES ARE LESS TODAY. THESE FACTORS ALL SUPPORT LESS AREAL
COVERAGE OF CONVECTION TODAY AND WEAKER UPDRAFTS WITH LESS
ORGANIZATION. WE WILL MENTION CHC POPS WITH GREATEST COVERAGE FROM
THE NORTHERN DACKS INTO CENTRAL/NORTHERN VT THIS AFTN...ALONG WITH
ISOLATED THUNDER. GIVEN LOW WET BULB FREEZING LEVELS BTWN 7000 AND
8000 FEET SOME PEA SIZE HAIL WILL BE POSSIBLE IN THE STRONGEST
CELLS...BUT NOT WIDESPREAD IN COVERAGE. QPF VALUES WILL GENERAL BE
LESS 0.10" BUT LOCALIZED HIGHER IN THE STRONGEST STORMS. PROGGED
85H TEMPS BTWN 8-10C SUPPORT HIGHS MAINLY IN THE U60S TO LOWER 70S
MTN TOWNS TO M/U 70S WARMER VALLEY LOCATIONS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
AS OF 345 AM EDT WEDNESDAY...LITTLE OVERALL CHANGE TO LARGE
SCALE SYNOPTIC PATTERN IS EXPECTED THROUGH FRIDAY WITH GENERAL
MID/UPPER LVL TROF ACROSS THE NE CONUS. HOWEVER...BEST DEEP LAYER
MOISTURE WILL BE SUPPRESSED TO OUR SOUTH DURING THE PERIOD WITH MUCH
LESS AREAL COVERAGE OF SHOWER ACTIVITY EXPECT ON THURS. SFC HIGH
PRES LOCATED OVER HUDSON BAY IS PROGGED TO NOSE INTO NORTHERN NY
DURING THIS PERIOD...RESULTING IN DRIER WX WITH LARGE DAILY SWINGS
IN TEMPS. LATEST TRENDS IN GUIDANCE HAS BEEN FOR COASTAL SYSTEM TO
PASS WELL SOUTH OF OUR CWA WITH GREATEST IMPACTS ACROSS THE SE CONUS
INTO THE MID ATLANTIC STATES. NW FLOW ALOFT COMBINED WITH WEAK 5H
VORT AND COOL POOL ALOFT WILL PRODUCE SPOTTY MAINLY DAYTIME HEAT
DRIVEN SHOWERS ACROSS THE DACKS INTO THE MTNS OF CENTRAL AND
NORTHERN VT ON THURS. WL MENTION SCHC IN THE CPV AND CHC POPS IN THE
MTNS WITH QPF VALUES GENERALLY < 0.10.
PROGGED 85H TEMPS COOL ANOTHER DEGREE OR TWO AND SUPPORT
MID/UPPER 60S MTNS TO NEK AND MID 70S WARMER VALLEYS...SEVERAL
DEGREES BELOW NORMAL FOR EARLY AUGUST. LITTLE CHANGE ANTICIPATED
ON FRIDAY WITH GENERAL NW FLOW ALOFT AND BUILDING SFC HIGH PRES.
WILL MENTION SCHC POPS IN THE MTNS AND KEEP REST OF FCST DRY ATTM.
PROGGED 85H TEMPS BTWN 8-10C SUPPORT HIGHS MAINLY IN THE 60S MTNS
TO 70S VALLEYS. LOWS WILL GENERALLY BE IN THE 40S COLDER MTN
VALLEYS TO 50S IN THE WIDER CHAMPLAIN AND SAINT LAWRENCE VALLEYS
THRU THE PERIOD.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 331 AM EDT WEDNESDAY...MID-LEVEL CYCLONIC FLOW/LONGWAVE
TROUGHING PREVAILS IN THE MEAN ACROSS THE NORTH COUNTRY DURING THE
EXTENDED. ALL-IN-ALL, A GENERALLY UNEVENTFUL PERIOD OF WEATHER
INTO THE EARLY PART OF THE WEEKEND, WITH BETTER CHANCES FOR
PRECIPITATION HOLDING OFF UNTIL SUNDAY AND EARLY NEXT WEEK.
FORECAST FOLLOWS BLENDED GUIDANCE UNLESS NOTED OTHERWISE.
EARLIER CYCLES OF GLOBAL GUIDANCE SUITE HAD INDICATED A POTENTIAL
COASTAL LOW DEVELOPING OFF THE MID-ATLANTIC COAST LATER FRIDAY AND
ITS PRECIPITATION SHIELD EXPANDING INTO EASTERN SECTIONS OF
VERMONT ON SATURDAY. WHILE RECENT GUIDANCE STILL SHOWS THIS
SYSTEM, A NOTED TREND HAS BEEN TO A POSITION FURTHER OFF THE COAST
RESULTING IN A MORE OPTIMISTIC EARLY-WEEKEND FORECAST. SO THE
BIGGEST CHANGE TO THE INHERITED FORECAST WAS TO LOWER POPS FOR THE
SATURDAY/SATURDAY NIGHT PERIOD FOR VERMONT. I DIDN`T WANT TO
COMPLETELY GO DRY ON THE CHANCE THAT A WESTWARD RECURVE REVEALS
ITSELF IN SUBSEQUENT GUIDANCE RUNS, BUT I`VE LOWERED DOWN TO
SLIGHT CHANCE.
00Z GFS/EC SOLUTIONS START TO DIFFER AFTER SUNDAY ON SENSIBLE
WEATHER DETAILS. WHILE BOTH GLOBAL SOLUTIONS DEPICT A 1000-500 MB
THICKNESS GRADIENT/WARM FRONT ACROSS THE NORTH COUNTRY AND RATHER
WEAK LOBES OF VORT MAXIMA ACTING ON THE BOUNDARY, THE GFS SHOWS
HARDLY ANY PRECIPITATION AT ALL. THAT`S A STRANGE/UNREALISTIC
RESULT. I`VE THEREFORE HEDGED CLOSER TO THE WETTER ECMWF IN
KEEPING CHANCE POPS GOING SUNDAY. CHANCE POPS CONTINUE INTO EARLY
NEXT WEEK AS THE BAROCLINIC ZONE MAKES LITTLE EASTWARD OR
NORTHWARD INROADS AND MAY SERVE AS A CONDUIT FOR CONTINUED RAIN
CHANCES. THERE IS SOME LIMITED INSTABILITY (LIFTED INDICES OF -1
TO -2), SO OPTED FOR SHOWERS/THUNDERSTORMS EACH DAY.
TEMPS THROUGH THE PERIOD ARE CLOSE TO NEAR EARLY-/MID-AUGUST
NORMALS WITH HIGHS IN THE 70S AND LOWS IN THE 50S/NEAR 60.
&&
.AVIATION /11Z WEDNESDAY THROUGH SUNDAY/...
THROUGH 12Z THURSDAY...VFR OUTSIDE OF DEVELOPING SCT
SHOWERS/STORMS WITH BRIEFLY REDUCED VISBILITIES AS LOW AS IFR.
POTENTIAL FOR IFR/LIFR FOG AT MPV AND SLK INTO THE OVERNIGHT.
INFRARED SATELLITE SHOWS SCT-BKN CLOUDS EXTENDING FROM NORTHEAST
CORNER OF VT BACK THROUGH THE ADIRONDACKS AHEAD OF SFC TROUGH OVER
SOUTHERN QUEBEC. THESE SHOULD THIN OUT INTO THE MORNING HOURS.
HOWEVER WITH A COLD POOL ALOFT ASSOCIATED WITH DEEP UPPER LOW,
SCT SHOWERS/STORMS WILL DEVELOP WITH DAYTIME HEATING. ANY STRONG
STORM THAT DEVELOPS WILL BE CAPABLE OF BRIEF IFR-VISIBILITY
DOWNPOURS, SMALL HAIL AND GUSTY OUTFLOW PRODUCING LOCALIZED
TURBULENCE. OVERALL COVERAGE OF STRONG STORMS WILL BE LIMITED.
BASED ON HRRR AND RECENT BTV WRF GUIDANCE, SHOWERS/STORMS MOST
FAVORED FOR ALL TERMINALS EXCEPT RUT AND STARTING AROUND 17Z WITH
6SM SHRA. DAYTIME WINDS WEST TO WEST/SOUTHWEST 6-10 KTS GUSTS
UNDER 20 KTS.
ANY SHOWERS/STORMS QUICKLY DISSIPATE NEAR/AFTER SUNSET. RISK OF
IFR/LIFR FOG AT SLK AND MPV IS CONDITIONAL ON CLEARING, WHICH
ISN`T CERTAIN. I`VE OPTED TO LEAVE OUT FOR NOW. WINDS SHOULD
BECOME LIGHT NORTHWEST (VARIABLE AT TIMES) THIS EVENING.
OUTLOOK 12Z THURSDAY THROUGH SUNDAY...
12Z THURSDAY - 00Z FRIDAY...MAINLY VFR WITH SPOTTY DIURNALLY-DRIVEN
SHOWERS.
00Z FRIDAY ONWARD...DAYTIME VFR WITH EVENING IFR/LIFR FOG AT MPV
AND SLK TERMINALS.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TABER
NEAR TERM...TABER
SHORT TERM...TABER
LONG TERM...LOCONTO
AVIATION...LOCONTO
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
714 AM EDT WED AUG 5 2015
.SYNOPSIS...
SHOWERS WITH EMBEDDED THUNDERSTORMS WILL BE POSSIBLE
AGAIN TODAY WITH TEMPERATURES MAINLY IN THE 70S. A SLOW DRYING TREND
WILL OCCUR ON THURSDAY AND CONTINUE INTO THE WEEKEND AS SURFACE HIGH
PRESSURE BUILDS INTO THE NORTH COUNTRY. TEMPERATURES WILL FEATURE
COOL NIGHTS AND MILD DAYS WITH VALUES VERY CLOSE TO NORMAL FOR THIS
TIME OF YEAR.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 345 AM EDT WEDNESDAY...LARGE SCALE SHOWS DEEP MID/UPPER LEVEL
TROF ACROSS THE NE CONUS WITH NUMEROUS EMBEDDED 5H VORTS. WATER
VAPOR SHOWS BEST DEEP LAYER MOISTURE HAS SHIFTED INTO THE MID
ATLANTIC STATES WITH TROF AXIS DIRECTLY OVERHEAD. THIS WILL RESULT
IN COOL POOL ALOFT WITH 500 TEMPS NEAR -18C TODAY...WHICH WILL HELP
TO STEEPEN LAPSE RATES AND CREATE SOME INSTABILITY.
HOWEVER...SOUNDINGS SHOW LESS INSTABILITY THAN YESTERDAY FROM COOLER
SFC TEMPS AND DRIER DWPTS...IN ADDITION PW VALUES ARE LESS TODAY.
THESE FACTORS ALL SUPPORT LESS AREAL COVERAGE OF CONVECTION TODAY
AND WEAKER UPDRAFTS WITH LESS ORGANIZATION. WE WILL MENTION CHC POPS
WITH GREATEST COVERAGE FROM THE NORTHERN DACKS INTO CENTRAL/NORTHERN
VT THIS AFTN...ALONG WITH ISOLATED THUNDER. GIVEN LOW WET BULB
FREEZING LEVELS BTWN 7000 AND 8000 FEET SOME PEA SIZE HAIL WILL BE
POSSIBLE IN THE STRONGEST CELLS...BUT NOT WIDESPREAD IN COVERAGE.
QPF VALUES WILL GENERAL BE LESS 0.10" BUT LOCALIZED HIGHER IN THE
STRONGEST STORMS. PROGGED 85H TEMPS BTWN 8-10C SUPPORT HIGHS MAINLY
IN THE U60S TO LOWER 70S MTN TOWNS TO M/U 70S WARMER VALLEY
LOCATIONS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
AS OF 345 AM EDT WEDNESDAY...LITTLE OVERALL CHANGE TO LARGE
SCALE SYNOPTIC PATTERN IS EXPECTED THROUGH FRIDAY WITH GENERAL
MID/UPPER LVL TROF ACROSS THE NE CONUS. HOWEVER...BEST DEEP LAYER
MOISTURE WILL BE SUPPRESSED TO OUR SOUTH DURING THE PERIOD WITH MUCH
LESS AREAL COVERAGE OF SHOWER ACTIVITY EXPECT ON THURS. SFC HIGH
PRES LOCATED OVER HUDSON BAY IS PROGGED TO NOSE INTO NORTHERN NY
DURING THIS PERIOD...RESULTING IN DRIER WX WITH LARGE DAILY SWINGS
IN TEMPS. LATEST TRENDS IN GUIDANCE HAS BEEN FOR COASTAL SYSTEM TO
PASS WELL SOUTH OF OUR CWA WITH GREATEST IMPACTS ACROSS THE SE CONUS
INTO THE MID ATLANTIC STATES. NW FLOW ALOFT COMBINED WITH WEAK 5H
VORT AND COOL POOL ALOFT WILL PRODUCE SPOTTY MAINLY DAYTIME HEAT
DRIVEN SHOWERS ACROSS THE DACKS INTO THE MTNS OF CENTRAL AND
NORTHERN VT ON THURS. WL MENTION SCHC IN THE CPV AND CHC POPS IN THE
MTNS WITH QPF VALUES GENERALLY < 0.10.
PROGGED 85H TEMPS COOL ANOTHER DEGREE OR TWO AND SUPPORT
MID/UPPER 60S MTNS TO NEK AND MID 70S WARMER VALLEYS...SEVERAL
DEGREES BELOW NORMAL FOR EARLY AUGUST. LITTLE CHANGE ANTICIPATED
ON FRIDAY WITH GENERAL NW FLOW ALOFT AND BUILDING SFC HIGH PRES.
WILL MENTION SCHC POPS IN THE MTNS AND KEEP REST OF FCST DRY ATTM.
PROGGED 85H TEMPS BTWN 8-10C SUPPORT HIGHS MAINLY IN THE 60S MTNS
TO 70S VALLEYS. LOWS WILL GENERALLY BE IN THE 40S COLDER MTN
VALLEYS TO 50S IN THE WIDER CHAMPLAIN AND SAINT LAWRENCE VALLEYS
THRU THE PERIOD.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 331 AM EDT WEDNESDAY...MID-LEVEL CYCLONIC FLOW/LONGWAVE
TROUGHING PREVAILS IN THE MEAN ACROSS THE NORTH COUNTRY DURING THE
EXTENDED. ALL-IN-ALL, A GENERALLY UNEVENTFUL PERIOD OF WEATHER
INTO THE EARLY PART OF THE WEEKEND, WITH BETTER CHANCES FOR
PRECIPITATION HOLDING OFF UNTIL SUNDAY AND EARLY NEXT WEEK.
FORECAST FOLLOWS BLENDED GUIDANCE UNLESS NOTED OTHERWISE.
EARLIER CYCLES OF GLOBAL GUIDANCE SUITE HAD INDICATED A POTENTIAL
COASTAL LOW DEVELOPING OFF THE MID-ATLANTIC COAST LATER FRIDAY AND
ITS PRECIPITATION SHIELD EXPANDING INTO EASTERN SECTIONS OF
VERMONT ON SATURDAY. WHILE RECENT GUIDANCE STILL SHOWS THIS
SYSTEM, A NOTED TREND HAS BEEN TO A POSITION FURTHER OFF THE COAST
RESULTING IN A MORE OPTIMISTIC EARLY-WEEKEND FORECAST. SO THE
BIGGEST CHANGE TO THE INHERITED FORECAST WAS TO LOWER POPS FOR THE
SATURDAY/SATURDAY NIGHT PERIOD FOR VERMONT. I DIDN`T WANT TO
COMPLETELY GO DRY ON THE CHANCE THAT A WESTWARD RECURVE REVEALS
ITSELF IN SUBSEQUENT GUIDANCE RUNS, BUT I`VE LOWERED DOWN TO
SLIGHT CHANCE.
00Z GFS/EC SOLUTIONS START TO DIFFER AFTER SUNDAY ON SENSIBLE
WEATHER DETAILS. WHILE BOTH GLOBAL SOLUTIONS DEPICT A 1000-500 MB
THICKNESS GRADIENT/WARM FRONT ACROSS THE NORTH COUNTRY AND RATHER
WEAK LOBES OF VORT MAXIMA ACTING ON THE BOUNDARY, THE GFS SHOWS
HARDLY ANY PRECIPITATION AT ALL. THAT`S A STRANGE/UNREALISTIC
RESULT. I`VE THEREFORE HEDGED CLOSER TO THE WETTER ECMWF IN
KEEPING CHANCE POPS GOING SUNDAY. CHANCE POPS CONTINUE INTO EARLY
NEXT WEEK AS THE BAROCLINIC ZONE MAKES LITTLE EASTWARD OR
NORTHWARD INROADS AND MAY SERVE AS A CONDUIT FOR CONTINUED RAIN
CHANCES. THERE IS SOME LIMITED INSTABILITY (LIFTED INDICES OF -1
TO -2), SO OPTED FOR SHOWERS/THUNDERSTORMS EACH DAY.
TEMPS THROUGH THE PERIOD ARE CLOSE TO NEAR EARLY-/MID-AUGUST
NORMALS WITH HIGHS IN THE 70S AND LOWS IN THE 50S/NEAR 60.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
THROUGH 12Z THURSDAY...VFR OUTSIDE OF DEVELOPING SCT
SHOWERS/STORMS WITH BRIEFLY REDUCED VISBILITIES AS LOW AS IFR.
POTENTIAL FOR IFR/LIFR FOG AT MPV AND SLK INTO THE OVERNIGHT.
INFRARED SATELLITE SHOWS SCT-BKN CLOUDS EXTENDING FROM NORTHEAST
CORNER OF VT BACK THROUGH THE ADIRONDACKS AHEAD OF SFC TROUGH OVER
SOUTHERN QUEBEC. THESE SHOULD THIN OUT INTO THE MORNING HOURS.
HOWEVER WITH A COLD POOL ALOFT ASSOCIATED WITH DEEP UPPER LOW,
SCT SHOWERS/STORMS WILL DEVELOP WITH DAYTIME HEATING. ANY STRONG
STORM THAT DEVELOPS WILL BE CAPABLE OF BRIEF IFR-VISIBILITY
DOWNPOURS, SMALL HAIL AND GUSTY OUTFLOW PRODUCING LOCALIZED
TURBULENCE. OVERALL COVERAGE OF STRONG STORMS WILL BE LIMITED.
BASED ON HRRR AND RECENT BTV WRF GUIDANCE, SHOWERS/STORMS MOST
FAVORED FOR ALL TERMINALS EXCEPT RUT AND STARTING AROUND 17Z WITH
6SM SHRA. DAYTIME WINDS WEST TO WEST/SOUTHWEST 6-10 KTS GUSTS
UNDER 20 KTS.
ANY SHOWERS/STORMS QUICKLY DISSIPATE NEAR/AFTER SUNSET. RISK OF
IFR/LIFR FOG AT SLK AND MPV IS CONDITIONAL ON CLEARING, WHICH
ISN`T CERTAIN. I`VE OPTED TO LEAVE OUT FOR NOW. WINDS SHOULD
BECOME LIGHT NORTHWEST (VARIABLE AT TIMES) THIS EVENING.
OUTLOOK 12Z THURSDAY THROUGH SUNDAY...
12Z THURSDAY - 00Z FRIDAY...MAINLY VFR WITH SPOTTY DIURNALLY-DRIVEN
SHOWERS.
00Z FRIDAY ONWARD...DAYTIME VFR WITH EVENING IFR/LIFR FOG AT MPV
AND SLK TERMINALS.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TABER
NEAR TERM...TABER
SHORT TERM...TABER
LONG TERM...LOCONTO
AVIATION...LOCONTO
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
353 PM EDT WED AUG 5 2015
.SYNOPSIS...
TEMPERATURES ARE EXPECTED TO REMAIN ABOVE NORMAL THROUGH THURSDAY.
ISOLATED THUNDERSTORMS THIS AFTERNOON WILL INCREASE IN COVERAGE
THURSDAY...AS MORE MOISTURE IS BROUGHT INTO THE REGION. AN AREA
OF LOW PRESSURE AND ITS COLD FRONT WILL APPROACH FROM THE WEST AND
MOVE ACROSS THE AREA FRIDAY AND FRIDAY NIGHT...BRINGING A CHANCE
OF RAINFALL. A DRYING TREND IS EXPECTED INTO THE WEEKEND...AS HIGH
PRESSURE CROSSES THE AREA SATURDAY THROUGH MONDAY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
AS OF 211 PM WEDNESDAY...THUS FAR DEEP CONVECTION HAS BEEN HELD
OFF BY SUBSIDENCE AND MID LEVEL DRY AIR. VISIBLE SATELLITE SO FAR
IS NOT EVEN SHOWING MUCH OF A CU FIELD...ALTHOUGH THERE IS AN
ABUNDANCE OF CIRRUS SPREADING OVER THE AREA. DESPITE THIS
CIRRUS...SOME OF WHICH APPEARS TO BE RATHER THICK...TEMPERATURES
CONTINUE TO CLIMB WITH WIDESPREAD MID 90S INLAND. DEWPOINTS ACROSS
WESTERN AREAS ARE TRENDING DOWN AS DRY AIR IS MIXED INTO THE
BOUNDARY LAYER. THIS SHOULD KEEP HEAT INDEX VALUES JUST BELOW HEAT
ADVISORY CRITERIA THROUGH THE REST OF THE AFTERNOON. FARTHER EAST
THE COMBINATION OF HIGHER RECENT RAINFALL AND ONSHORE FLOW IS
KEEPING DEWPOINTS A LITTLE HIGHER...RESULTING IN HEAT INDEX VALUES
ALREADY APPROACHING...AND IN SOME CASES EXCEEDING...105 DEGREES.
HIGH RESOLUTION SHORT TERM GUIDANCE STILL EXPECTING ISOLATED
CONVECTION ALONG THE SEA BREEZE/PIEDMONT TROUGH THIS AFTERNOON.
MLCAPE WILL APPROACH 3000 J/KG DURING THE AFTERNOON BUT THE
UNFAVORABLE ENVIRONMENT IS A BIG OBSTACLE TO OVERCOME. HAVE HELD
ONTO SLIGHT CHC POP FOR THE AFTERNOON/EVENING HOURS GIVEN TEMPS IN
THE MID TO UPPER 90S AND DEWPOINTS IN SOME AREAS IN THE MID 70S.
ANY CONVECTION THAT DOES DEVELOP THIS AFTERNOON WILL NOT LAST MUCH
BEYOND SUNSET GIVEN THE LACK OF MID LEVEL SUPPORT. ALTHOUGH
LINGERING CU AND EVEN DEBRIS CLOUD IS LIKELY TO BE GONE BY
MIDNIGHT CIRRUS WILL CONTINUE TO STREAM IN FROM THE WEST AS
PROGRESSIVE MID LEVEL FLOW SPREADS CONVECTIVE CIRRUS BLOW OFF
EAST. PATCHY FOG MAY DEVELOP LATE IN THE PERIOD BUT VISIBILITIES
SHOULD REMAIN ABOVE 3SM IN MOST AREAS. LOWS WILL BE ABOVE
CLIMO...MID 70S IN MOST AREAS.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
AS OF 211 PM WEDNESDAY...PRIMARY WEATHER HEADLINE ARE PROSPECTS
OF RAINFALL ACROSS THE REGION LATE THURSDAY...ESPECIALLY THROUGH
FRIDAY...AS A QUASI-STATIONARY SURFACE LOW PRESSURE ENTITY ALONG
THE COASTAL INTERIOR THURSDAY...EJECTS TO SEA FRIDAY. A FRONTAL
PASSAGE WILL ACCOMPANY THIS MIGRATION OFFSHORE FRIDAY NIGHT.
SATELLITE DATA SHOWS AN AXIS OF HIGH PRECIPITABLE WATER BETWEEN
1.85 AND 2.10 INCHES POSITIONED ACROSS THE GULF STATES AND THE
COASTAL CAROLINAS...AVAILABLE FOR INGEST BY A LOW PRESSURE
FEATURE. A MARGINAL RISK REMAINS INTACT FRIDAY ACROSS THE AREA AS
A MID-LVL TROUGH TRAVERSES THE REGION. A COOLING TREND SHOULD BE
IN THE OFFERING EACH DAY THU/FRI...AS MOIST ONSHORE WINDS AND
CLOUDS TEAM...AND POTENTIALLY RAIN-COOLED AIR FRIDAY.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 300 PM WEDNESDAY...MID TO UPPER TROUGH WILL MOVE FARTHER AWAY
AS RIDGE OVER THE SOUTH CENTRAL CONUS TRIES TO NOSE ITS WAY INTO THE
SOUTHEAST STATES. A DEEP DRIER N-NW FLOW WILL LAST THROUGH MUCH OF
THE WEEKEND WITH PCP WATER VALUES DECREASING FROM UP NEAR 1.75
INCHES EARLY SATURDAY DOWN TO LESS THAN AN INCH BY SUNDAY MORNING.
ANY LINGERING MOISTURE OR CLOUDS EARLY SATURDAY WILL DIMINISH
THROUGH THE DAY. WINDS WILL LIGHTEN AND BEGIN TO VEER AROUND BY LATE
SUNDAY...CAPTURING THE RICH MARINE AIR ONCE AGAIN AND BRINGING
DEWPOINT TEMPS THAT WERE DOWN IN THE 60S OVER THE WEEKEND BACK UP TO
70S BY SUN NIGHT INTO MONDAY...ESPECIALLY CLOSER TO THE COAST.
OVERALL EXPECT CLEARING AND DRYING THROUGH SATURDAY AND A DRY START
TO SUNDAY. WILL KEEP OUT POPS MOST OF THE WEEKEND...BUT ECMWF DOES
WANT TO BRING A LITTLE IMPULSE DOWN OVER THE AREA JUST IN TIME TO
PEAK HEATING ON SUNDAY. THIS MAY ENHANCE CONVERGENCE ALONG SEA
BREEZE TO AT LEAST PRODUCE SOME CU OR A SHOWER OR TWO.
WEAK HIGH PRESSURE OVER THE AREA OVER THE WEEKEND WILL MAKE ITS WAY
OFF THE COAST ALLOWING FOR A DEEPER MOISTURE RETURN MON INTO TUES
WITH A DECENT W-SW FLOW DEVELOPING THROUGHOUT THE LOW TO MID LEVELS.
BY NEXT TUES NEXT MID TO UPPER LEVEL TROUGH WILL DIG DOWN FROM THE
GREAT LAKES AND SHOULD PUSH FRONT EASTWARD INTO THE CAROLINAS. THIS
WILL ENHANCE CONVECTION AND BRING BACK BETTER CHC OF SHWRS AND
THUNDERSTORMS OVER THE COASTAL CAROLINAS TUES AND WED.
TEMPS WILL ACTUALLY RUN BELOW NORMAL THROUGH MUCH OF THE PERIOD WITH
HIGH TEMPS IN THE MID TO UPPER 80S AND POTENTIAL FOR LOW TEMPS TO
DROP BELOW 70 OVERNIGHT SAT. H5 HEIGHTS WILL REBOUND BACK THROUGH
EARLY NEXT WEEK AND THEN INCREASING SE TO SOUTHERLY FLOW WILL BRING
TEMPS BACK UP TO NORMAL OR ABOVE MON THROUGH WED.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
AS OF 18Z...BOTH THE WRF AND THE HRRR DEPICT CONVECTION THIS
AFTERNOON ALONG THE SEA BREEZE BOUNDARY. IF CONVECTION DOES MANAGE
TO GET GOING...THE STEERING FLOW WILL MOVE THE STORMS TO THE
SOUTHEAST...KEEPING THEM ALONG THE COAST. THE BEST CHANCE WILL BE
PENDER AND NEW HANOVER COUNTIES...WHERE THE ANGLE SEA BREEZE
BOUNDARIES OVERLAP. LIGHT SOUTHWEST FLOW THROUGH THE FORECAST
PERIOD...MORE SOUTHERLY BY LATE AFTERNOON ALONG THE COAST. SOME
LIGHT MORNING FOG POSSIBLE ON THURSDAY.
EXTENDED OUTLOOK...INCREASING CHANCES FOR CONVECTION THURSDAY NIGHT
THROUGH FRIDAY WITH THE APPROACH OF A COLD FRONT. HIGH PRESSURE WILL
NOSE IN FROM THE NORTH SATURDAY AND SUNDAY. CHANCE FOR STORMS
MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 211 PM WEDNESDAY...GRADIENT REMAINS RELATIVELY WEAK OVER
THE WATERS THIS AFTERNOON. SEA BREEZE HAS DEVELOPED AND RESULTED
IN SLIGHTLY ENHANCE ONSHORE FLOW AT THE COAST BUT HAS HAD LIMITED
EFFECT ACROSS THE BULK OF THE MARINE ZONES. SOUTHWEST FLOW 10 TO
15 KT WILL CONTINUE THROUGH THE AFTERNOON HOURS AND OVERNIGHT.
GUST MAY OCCASIONALLY HIT 20 KT BUT OCCURRENCES WILL BE
INFREQUENT. SEAS RUN 2 TO 4 FT WITH AN ISOLATED 5 FT POSSIBLE IN
EASTERN AND SOUTHERN ENDS OF AMZ252 AND AMZ250 RESPECTIVELY.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 211 PM WEDNESDAY...NEARLY THE ENTIRETY OF THIS PERIOD WILL
BE MARKED BY AN ELONGATED SURFACE LOW PRESSURE AXIS
INLAND...ORIENTED WSW-ENE ACROSS THE COASTAL INTERIOR OF NE SC AND
SE NC. WOBBLES AND FLUCTUATIONS WITH THIS FEATURES WILL BRING
VARYING WINDSPEEDS BETWEEN 10-20 KNOTS...BUT IN GENERAL A
CONSISTENT SW DIRECTION. SEAS THIS PERIOD WILL BE COMPOSED OF ESE
WAVES AROUND 2 FT EVERY 9-10 SECONDS AND SHORTER PERIOD...LOCALLY
DERIVED WIND-WAVES OF SSW 1-3 FT EVERY 4-5 SECONDS. TSTMS OVER THE
WATERS WILL SEE A NOTABLE INCREASE LATE THURSDAY NIGHT THROUGH
FRIDAY...AS A LOW PRESSURE AREA IS KICKED OFFSHORE AND A FRONTAL
BOUNDARY CROSSES THE 0-20 NM WATERS FRIDAY.
LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 300 PM WEDNESDAY...LIGHT SURGE OF NORTHERLY WINDS WILL DEVELOP
EARLY SATURDAY BEHIND DEPARTING FRONT...FOLLOWED BY WEAK HIGH
PRESSURE SETTLING IN FOR THE WEEKEND. OVERALL DO NOT EXPECT WINDS TO
EXCEED MUCH MORE THAN 15 KTS SPIKING UP MAINLY INITIALLY BEHIND
FRONT AND WITH AFTN SEA BREEZE. AS THE CENTER OF THE HIGH MEANDERS
SLOWLY EASTWARD THE WINDS WILL BEGIN TO VEER AROUND FROM NORTH EARLY
SATURDAY TO A MORE ON SHORE EASTERLY DIRECTION BY LATE SUNDAY AND
SOUTHEAST BY MONDAY MORNING.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR SCZ032-033-039-
053>056.
NC...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR NCZ096-099-
105>110.
MARINE...NONE.
&&
$$
SYNOPSIS...MJC
NEAR TERM...III
SHORT TERM...MJC
LONG TERM...RGZ
AVIATION...DL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
325 PM EDT WED AUG 5 2015
.SYNOPSIS...A COLD FRONT WILL SETTLE SOUTHWARD THEN STALL OUT OVER
NORTH CAROLINA TONIGHT THROUGH THURSDAY. A WAVE OF LOW PRESSURE WILL
TRACK EASTWARD ALONG THE FRONT LATE THURSDAY THROUGH FRIDAY...
SHIFTING OFF THE COAST FRIDAY NIGHT AS THE FRONT PUSHES TO OUR SOUTH.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 310 PM WEDNESDAY...
STILL APPEARS THAT THE VAST MAJORITY OF CENTRAL NC WILL STAY DRY
THROUGH TONIGHT. THE EXCEPTIONS WILL BE ACROSS THE FAR NORTH... AND
IN THE FAR SOUTHERN CWA THROUGH EARLY EVENING. THE SURFACE FRONTAL
ZONE TO OUR NORTH HAS MOVED LITTLE IN RECENT HOURS... STILL
STRETCHING ACROSS SRN VA INTO SE KY (ALTHOUGH PASSAGE OF NUMEROUS
CONVECTIVE OUTFLOWS FURTHER WEST INTO THE MID MISS VALLEY HAS
PROPELLED THE SYNOPTIC FRONT SOUTHWARD THERE). SURFACE HIGH PRESSURE
CENTERED WELL TO THE NW OVER THE NRN GREAT LAKES REGION INTO WRN
ONTARIO WILL SHIFT EASTWARD TONIGHT... AND THIS MORE DENSE AIR MAY
BE JUST ENOUGH TO NUDGE THE FRONT SOUTHWARD INTO NRN NC... HOWEVER
IT`S DIFFICULT TO DETERMINE HOW FAR SOUTH IT WILL GET. OUTSIDE OF
THE FAR NRN CWA... IT`S MORE LIKELY THAT WE`LL SEE A WIND SHIFT BUT
RELATIVELY LITTLE DROP IN THICKNESSES OVER MOST OF THE CWA
OVERNIGHT. WEAK MID LEVEL MCV/S NOW OVER WRN KY/TN WILL CONTINUE TO
MOVE EASTWARD TOWARD WRN VA/WRN NC TONIGHT... HOWEVER THESE MAY
UNDERGO DEAMPLIFICATION DUE TO THE STRENGTH/INFLUENCE OF THE MID
LEVEL TROUGH AXIS STRETCHING FROM SE NEB INTO NRN ARK AS IT SHIFTS
TO THE ESE... EFFECTIVELY REINFORCING THE WEAK MID LEVEL RIDGING NOW
OVER OUR REGION AND REDUCING OR ELIMINATING ANY TANGIBLE DYNAMIC
FORCING FOR ASCENT. THE LATEST HI-RES NMM/ARW AND RECENT HRRR RUNS
SUPPORT EARLIER OUTPUT FROM THE NCAR ENSEMBLE AND NSSL WRF SHOWING
ISOLATED CELLS IN THE FAR SRN CWA INTO SC (AS IS OCCURRING) WITHIN
THE HIGHER LOW-LEVEL LAPSE RATE NEAR A LOW LEVEL THERMAL / MOISTURE
GRADIENT (NOTED IN SFC-925-850 MB RAP ANALYSES) THROUGH EARLY
EVENING... AND OVER THE FAR NRN CWA NEAR THE FRONTAL ZONE... WHERE
RECOVERING PW (EXPECTED TO INCH UP CLOSER TO 1.5" TONIGHT)... WEAK
LOW LEVEL MASS CONVERGENCE... AND STEEPER MID LEVEL LAPSE RATES WILL
PROMPT ISOLATED TO SCATTERED CONVECTION... LASTING UNTIL THE 05Z-07Z
TIME FRAME... AFTER LOSS OF HEATING. WILL MAINTAIN THIS POP
CONFIGURATION THROUGH TONIGHT... WITH NO MORE THAN A LOW-END CHANCE
POP ANYWHERE GIVEN THE WEAK LIFT AND FOCUS. SHOULD SEE A FAIR AMOUNT
OF CONVECTIVE DEBRIS CLOUDS DRIFTING OVERHEAD ESPECIALLY LATER
TONIGHT... YIELDING A GENERALLY PARTLY CLOUDY SKY. LOWS FROM AROUND
68 NORTH TO 74 SOUTH. -GIH
&&
.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
AS OF 320 PM WEDNESDAY...
CONFIDENCE IS FAIRLY HIGH IN A TREND TO UNSETTLED WEATHER FOR THIS
TIME PERIOD. THE AFOREMENTIONED SHORTWAVE TROUGH WILL CONTINUE
HEADING ESE... LIKELY PRECEDED BY SEVERAL OUTFLOWS AND WEAKER WAVES
THAT WILL HELP FURTHER MOISTEN THE COLUMN... STARTING WITH THE MID
AND UPPER LEVELS AND EXPANDING GROUNDWARD HEADING INTO THU EVENING.
MODEL CONSENSUS IS FOR INCREASING CHANCES FOR SHOWERS AND STORMS THU
AFTERNOON REMAINING ELEVATED THROUGH THU NIGHT... ALTHOUGH
VARIATIONS IN THE DETAILS PERSIST WITH THE NAM/SREF MEAN/ECMWF MUCH
FASTER (BY ROUGHLY 6 HRS) TO SPREAD PRECIP EASTWARD ACROSS NC THAN
THE GFS. GIVEN THE OVERALL STRENGTHENING OF UPPER DIVERGENCE OVER
THE REGION BY 18Z-00Z AND WIDESPREAD 30-40 M HEIGHT FALLS... TEND TO
FAVOR THE FASTER ARRIVAL OF HIGHER CONVECTION COVERAGE. WILL KEEP
THE TREND UP TOWARD CHANCE POPS ARRIVING IN THE NW FIRST DURING THE
EARLY TO MID AFTERNOON... SPREADING QUICKLY EASTWARD WITH RISING
POPS TOWARD LIKELY FROM MID AFTERNOON ONWARD... KEEPING HIGH POPS
THROUGH THE NIGHT AS THE MID LEVEL SHORTWAVE TROUGH AND ACCOMPANYING
POTENT SURFACE LOW TRAVERSE THE AREA WITH ADDED LOW LEVEL MASS
CONVERGENCE ESPECIALLY ACROSS THE NORTH. WHILE A FEW STRONGER STORMS
APPEAR POSSIBLE GIVEN THE ADDED DYNAMIC FORCING FOR ASCENT AND
STRENGTHENING MID LEVEL FLOW (BOTH MORE THAN WE TYPICALLY SEE IN
YOUR AVERAGE EARLY AUGUST TIME PERIOD)... AN EARLIER ONSET AND
CONSIDERABLE CLOUDS OUT AHEAD OF THE WAVE SHOULD SUPPRESS CAPE
VALUES A BIT... KEEPING INSTABILITY MARGINAL AT MOST ESPECIALLY IN
THE NORTHWEST. EXPECT HIGHS OF 87-95 (A TAD LOWER THAN GUIDANCE IN
THE NW GIVEN THE LIMITED HEATING AND CLOSER TO GUIDANCE IN THE SE).
LOWS 67-74. -GIH
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AS OF 245 PM WEDNESDAY...
OVERALL THE SYNOPTIC PATTERN THROUGHOUT THE LONG TERM PERIOD WILL
FEATURE RIDGING OVER THE SOUTH-CENTRAL/SOUTHWEST CONUS AND TROUGHING
OVER THE EAST. TO BEGIN THE LONG TERM PERIOD...MODELS HAVE SLOW THE
PROGRESSION OF A SHORT WAVE TROUGH ACROSS THE AREA EARLY FRIDAY AND
A SECONDARY `KICKER` WAVE LATE FRIDAY INTO SATURDAY. AS A RESULT...
PRECIP CHANCES WILL BE SLOWER TO EXIT THE REGION...WITH MUCH OF THE
DAY ON FRIDAY LOOKING TO HAVE DECENT PRECIP CHANCES. PRECIP CHANCES
WILL DECREASE FROM WEST TO EAST DURING THE AFTERNOON/EVENING HOURS
AS THE LOW FINALLY LIFTS TO THE NORTHEAST THE SURFACE FRONT IS
PUSHED FURTHER TO THE SOUTH/EAST.
FOR THE WEEKEND...MODELS ARE IN FAIRLY GOOD AGREEMENT WITH THE FRONT
BEING PUSHED TO OUR SOUTH/EAST...AND BECOMING NEARLY STATIONARY
THERE. HIGH PRESSURE WILL BUILD IN AND THIS SHOULD RESULT IN A
MOSTLY DRY FORECAST...WITH ONLY SOME ISOLATED DIURNAL TYPE
ACTIVITY...MOSTLY ACROSS THE SOUTH/EAST IN CLOSER PROXIMITY TO THE
BOUNDARY AND MAYBE IN THE WESTERN PIEDMONT BY SUNDAY AS ACTIVITY
DEVELOPING IN THE HIGHER TERRAIN MAY DRIFT INTO THAT AREA.
THE HIGH WILL BEGIN TO SHIFT OFFSHORE EARLY NEXT WEEK AND THEREFORE
MOISTURE/PRECIP CHANCES WILL SLOWLY BEGIN TO INCREASE. OUR NEXT
FRONT IS PROGGED TO APPROACH FROM THE WEST ON TUESDAY OR WEDNESDAY
BRINGING BETTER CHANCES OF PRECIP TO THE AREA ONCE AGAIN.
TEMPS WILL BE BELOW NORMAL FRIDAY AND SATURDAY...BEFORE GRADUALLY
MODERATING BACK UP TO NEAR/SLIGHTLY ABOVE NORMAL BY NEXT WEEK.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 125 PM WEDNESDAY...
HIGH CONFIDENCE IN VFR CONDITIONS DOMINATING AT ALL CENTRAL NC
TERMINALS THROUGH EARLY THU AFTERNOON. A COLD FRONT WILL DROP
SOUTHWARD INTO NC LATE TODAY AND TONIGHT... THEN STALL OUT THROUGH
THU. ISOLATED SHOWERS AND STORMS ARE POSSIBLE OVER NORTHWEST AND
NORTH CENTRAL TERMINALS (INT/GSO/RDU) VERY LATE THIS AFTERNOON
THROUGH TONIGHT (MAINLY 21Z THROUGH 06Z) BUT ANY MVFR VSBYS/CIGS
WOULD BE VERY ISOLATED AND LAST LESS THAN AN HOUR AT ANY GIVEN SPOT.
LOOKING BEYOND 18Z THU... THE CHANCE FOR SUB-VFR CONDITIONS WILL
INCREASE LATE THU AFTERNOON INTO THU NIGHT... CONTINUING THROUGH
MUCH OF FRI... AS A WAVE OF LOW PRESSURE AND UPPER LEVEL DISTURBANCE
TRACK ALONG THE FRONT ACROSS THE REGION... BRINGING SCATTERED TO
NUMEROUS SHOWERS/STORMS. SHOWER/STORM CHANCES WILL DIMINISH FRI
NIGHT AS THE FRONT SETTLES SOUTH OF THE AREA... BUT SUB-VFR
CIGS/VSBYS ARE LIKELY TO LINGER UNTIL SAT MORNING... WHEN A HIGH
PRESSURE RIDGE WILL BUILD IN FROM THE NORTH... AND PERSIST INTO
MONDAY WITH MAINLY VFR CONDITIONS MID MORNING SAT THROUGH MON. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...HARTFIELD
LONG TERM...KRD
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
320 PM EDT WED AUG 5 2015
.SYNOPSIS...
TEMPERATURES ARE EXPECTED TO REMAIN ABOVE NORMAL THROUGH THURSDAY.
ISOLATED THUNDERSTORMS THIS AFTERNOON WILL INCREASE IN COVERAGE
THURSDAY...AS MORE MOISTURE IS BROUGHT INTO THE REGION. AN AREA
OF LOW PRESSURE AND ITS COLD FRONT WILL APPROACH FROM THE WEST AND
MOVE ACROSS THE AREA FRIDAY AND FRIDAY NIGHT...BRINGING A CHANCE
OF RAINFALL. A DRYING TREND IS EXPECTED INTO THE WEEKEND...AS HIGH
PRESSURE CROSSES THE AREA SATURDAY THROUGH MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 211 PM WEDNESDAY...THUS FAR DEEP CONVECTION HAS BEEN HELD
OFF BY SUBSIDENCE AND MID LEVEL DRY AIR. VISIBLE SATELLITE SO FAR
IS NOT EVEN SHOWING MUCH OF A CU FIELD...ALTHOUGH THERE IS AN
ABUNDANCE OF CIRRUS SPREADING OVER THE AREA. DESPITE THIS
CIRRUS...SOME OF WHICH APPEARS TO BE RATHER THICK...TEMPERATURES
CONTINUE TO CLIMB WITH WIDESPREAD MID 90S INLAND. DEWPOINTS ACROSS
WESTERN AREAS ARE TRENDING DOWN AS DRY AIR IS MIXED INTO THE
BOUNDARY LAYER. THIS SHOULD KEEP HEAT INDEX VALUES JUST BELOW HEAT
ADVISORY CRITERIA THROUGH THE REST OF THE AFTERNOON. FARTHER EAST
THE COMBINATION OF HIGHER RECENT RAINFALL AND ONSHORE FLOW IS
KEEPING DEWPOINTS A LITTLE HIGHER...RESULTING IN HEAT INDEX VALUES
ALREADY APPROACHING...AND IN SOME CASES EXCEEDING...105 DEGREES.
HIGH RESOLUTION SHORT TERM GUIDANCE STILL EXPECTING ISOLATED
CONVECTION ALONG THE SEA BREEZE/PIEDMONT TROUGH THIS AFTERNOON.
MLCAPE WILL APPROACH 3000 J/KG DURING THE AFTERNOON BUT THE
UNFAVORABLE ENVIRONMENT IS A BIG OBSTACLE TO OVERCOME. HAVE HELD
ONTO SLIGHT CHC POP FOR THE AFTERNOON/EVENING HOURS GIVEN TEMPS IN
THE MID TO UPPER 90S AND DEWPOINTS IN SOME AREAS IN THE MID 70S.
ANY CONVECTION THAT DOES DEVELOP THIS AFTERNOON WILL NOT LAST MUCH
BEYOND SUNSET GIVEN THE LACK OF MID LEVEL SUPPORT. ALTHOUGH
LINGERING CU AND EVEN DEBRIS CLOUD IS LIKELY TO BE GONE BY
MIDNIGHT CIRRUS WILL CONTINUE TO STREAM IN FROM THE WEST AS
PROGRESSIVE MID LEVEL FLOW SPREADS CONVECTIVE CIRRUS BLOW OFF
EAST. PATCHY FOG MAY DEVELOP LATE IN THE PERIOD BUT VISIBILITIES
SHOULD REMAIN ABOVE 3SM IN MOST AREAS. LOWS WILL BE ABOVE
CLIMO...MID 70S IN MOST AREAS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 211 PM WEDNESDAY...PRIMARY WEATHER HEADLINE ARE PROSPECTS
OF RAINFALL ACROSS THE REGION LATE THURSDAY...ESPECIALLY THROUGH
FRIDAY...AS A QUASI-STATIONARY SURFACE LOW PRESSURE ENTITY ALONG
THE COASTAL INTERIOR THURSDAY...EJECTS TO SEA FRIDAY. A FRONTAL
PASSAGE WILL ACCOMPANY THIS MIGRATION OFFSHORE FRIDAY NIGHT.
SATELLITE DATA SHOWS AN AXIS OF HIGH PRECIPITABLE WATER BETWEEN
1.85 AND 2.10 INCHES POSITIONED ACROSS THE GULF STATES AND THE
COASTAL CAROLINAS...AVAILABLE FOR INGEST BY A LOW PRESSURE
FEATURE. A MARGINAL RISK REMAINS INTACT FRIDAY ACROSS THE AREA AS
A MID-LVL TROUGH TRAVERSES THE REGION. A COOLING TREND SHOULD BE
IN THE OFFERING EACH DAY THU/FRI...AS MOIST ONSHORE WINDS AND
CLOUDS TEAM...AND POTENTIALLY RAIN-COOLED AIR FRIDAY.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 300 PM WEDNESDAY...MID TO UPPER TROUGH WILL MOVE FARTHER AWAY
AS RIDGE OVER THE SOUTH CENTRAL CONUS TRIES TO NOSE ITS WAY INTO THE
SOUTHEAST STATES. A DEEP DRIER N-NW FLOW WILL LAST THROUGH MUCH OF
THE WEEKEND WITH PCP WATER VALUES DECREASING FROM UP NEAR 1.75
INCHES EARLY SATURDAY DOWN TO LESS THAN AN INCH BY SUNDAY MORNING.
ANY LINGERING MOISTURE OR CLOUDS EARLY SATURDAY WILL DIMINISH
THROUGH THE DAY. WINDS WILL LIGHTEN AND BEGIN TO VEER AROUND BY LATE
SUNDAY...CAPTURING THE RICH MARINE AIR ONCE AGAIN AND BRINGING
DEWPOINT TEMPS THAT WERE DOWN IN THE 60S OVER THE WEEKEND BACK UP TO
70S BY SUN NIGHT INTO MONDAY...ESPECIALLY CLOSER TO THE COAST.
OVERALL EXPECT CLEARING AND DRYING THROUGH SATURDAY AND A DRY START
TO SUNDAY. WILL KEEP OUT POPS MOST OF THE WEEKEND...BUT ECMWF DOES
WANT TO BRING A LITTLE IMPULSE DOWN OVER THE AREA JUST IN TIME TO
PEAK HEATING ON SUNDAY. THIS MAY ENHANCE CONVERGENCE ALONG SEA
BREEZE TO AT LEAST PRODUCE SOME CU OR A SHOWER OR TWO.
WEAK HIGH PRESSURE OVER THE AREA OVER THE WEEKEND WILL MAKE ITS WAY
OFF THE COAST ALLOWING FOR A DEEPER MOISTURE RETURN MON INTO TUES
WITH A DECENT W-SW FLOW DEVELOPING THROUGHOUT THE LOW TO MID LEVELS.
BY NEXT TUES NEXT MID TO UPPER LEVEL TROUGH WILL DIG DOWN FROM THE
GREAT LAKES AND SHOULD PUSH FRONT EASTWARD INTO THE CAROLINAS. THIS
WILL ENHANCE CONVECTION AND BRING BACK BETTER CHC OF SHWRS AND
THUNDERSTORMS OVER THE COASTAL CAROLINAS TUES AND WED.
TEMPS WILL ACTUALLY RUN BELOW NORMAL THROUGH MUCH OF THE PERIOD WITH
HIGH TEMPS IN THE MID TO UPPER 80S AND POTENTIAL FOR LOW TEMPS TO
DROP BELOW 70 OVERNIGHT SAT. H5 HEIGHTS WILL REBOUND BACK THROUGH
EARLY NEXT WEEK AND THEN INCREASING SE TO SOUTHERLY FLOW WILL BRING
TEMPS BACK UP TO NORMAL OR ABOVE MON THROUGH WED.
&&
.AVIATION /18Z WEDNESDAY THROUGH SUNDAY/...
AS OF 18Z...BOTH THE WRF AND THE HRRR DEPICT CONVECTION THIS
AFTERNOON ALONG THE SEA BREEZE BOUNDARY. IF CONVECTION DOES MANAGE
TO GET GOING...THE STEERING FLOW WILL MOVE THE STORMS TO THE
SOUTHEAST...KEEPING THEM ALONG THE COAST. THE BEST CHANCE WILL BE
PENDER AND NEW HANOVER COUNTIES...WHERE THE ANGLE SEA BREEZE
BOUNDARIES OVERLAP. LIGHT SOUTHWEST FLOW THROUGH THE FORECAST
PERIOD...MORE SOUTHERLY BY LATE AFTERNOON ALONG THE COAST. SOME
LIGHT MORNING FOG POSSIBLE ON THURSDAY.
EXTENDED OUTLOOK...INCREASING CHANCES FOR CONVECTION THURSDAY NIGHT
THROUGH FRIDAY WITH THE APPROACH OF A COLD FRONT. HIGH PRESSURE WILL
NOSE IN FROM THE NORTH SATURDAY AND SUNDAY. CHANCE FOR STORMS
MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 211 PM WEDNESDAY...GRADIENT REMAINS RELATIVELY WEAK OVER
THE WATERS THIS AFTERNOON. SEA BREEZE HAS DEVELOPED AND RESULTED
IN SLIGHTLY ENHANCE ONSHORE FLOW AT THE COAST BUT HAS HAD LIMITED
EFFECT ACROSS THE BULK OF THE MARINE ZONES. SOUTHWEST FLOW 10 TO
15 KT WILL CONTINUE THROUGH THE AFTERNOON HOURS AND OVERNIGHT.
GUST MAY OCCASIONALLY HIT 20 KT BUT OCCURRENCES WILL BE
INFREQUENT. SEAS RUN 2 TO 4 FT WITH AN ISOLATED 5 FT POSSIBLE IN
EASTERN AND SOUTHERN ENDS OF AMZ252 AND AMZ250 RESPECTIVELY.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 211 PM WEDNESDAY...NEARLY THE ENTIRETY OF THIS PERIOD WILL
BE MARKED BY AN ELONGATED SURFACE LOW PRESSURE AXIS
INLAND...ORIENTED WSW-ENE ACROSS THE COASTAL INTERIOR OF NE SC AND
SE NC. WOBBLES AND FLUCTUATIONS WITH THIS FEATURES WILL BRING
VARYING WINDSPEEDS BETWEEN 10-20 KNOTS...BUT IN GENERAL A
CONSISTENT SW DIRECTION. SEAS THIS PERIOD WILL BE COMPOSED OF ESE
WAVES AROUND 2 FT EVERY 9-10 SECONDS AND SHORTER PERIOD...LOCALLY
DERIVED WIND-WAVES OF SSW 1-3 FT EVERY 4-5 SECONDS. TSTMS OVER THE
WATERS WILL SEE A NOTABLE INCREASE LATE THURSDAY NIGHT THROUGH
FRIDAY...AS A LOW PRESSURE AREA IS KICKED OFFSHORE AND A FRONTAL
BOUNDARY CROSSES THE 0-20 NM WATERS FRIDAY.
LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 300 PM WEDNESDAY...LIGHT SURGE OF NORTHERLY WINDS WILL DEVELOP
EARLY SATURDAY BEHIND DEPARTING FRONT...FOLLOWED BY WEAK HIGH
PRESSURE SETTLING IN FOR THE WEEKEND. OVERALL DO NOT EXPECT WINDS TO
EXCEED MUCH MORE THAN 15 KTS SPIKING UP MAINLY INITIALLY BEHIND
FRONT AND WITH AFTN SEA BREEZE. AS THE CENTER OF THE HIGH MEANDERS
SLOWLY EASTWARD THE WINDS WILL BEGIN TO VEER AROUND FROM NORTH EARLY
SATURDAY TO A MORE ON SHORE EASTERLY DIRECTION BY LATE SUNDAY AND
SOUTHEAST BY MONDAY MORNING.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR SCZ032-033-039-
053>056.
NC...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR NCZ099-105>110.
MARINE...NONE.
&&
$$
SYNOPSIS...MJC
NEAR TERM...III
SHORT TERM...MJC
LONG TERM...RGZ
AVIATION...DL/III
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
211 PM EDT WED AUG 5 2015
.SYNOPSIS...
TEMPERATURES ARE EXPECTED TO REMAIN ABOVE NORMAL THROUGH THURSDAY.
ISOLATED THUNDERSTORMS THIS AFTERNOON WILL INCREASE IN COVERAGE
THURSDAY...AS MORE MOISTURE IS BROUGHT INTO THE REGION. AN AREA
OF LOW PRESSURE AND ITS COLD FRONT WILL APPROACH FROM THE WEST AND
MOVE ACROSS THE AREA FRIDAY AND FRIDAY NIGHT...BRINGING A CHANCE
OF RAINFALL. A DRYING TREND IS EXPECTED INTO THE WEEKEND...AS HIGH
PRESSURE CROSSES THE AREA SATURDAY THROUGH MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 211 PM WEDNESDAY...THUS FAR DEEP CONVECTION HAS BEEN HELD
OFF BY SUBSIDENCE AND MID LEVEL DRY AIR. VISIBLE SATELLITE SO FAR
IS NOT EVEN SHOWING MUCH OF A CU FIELD...ALTHOUGH THERE IS AN
ABUNDANCE OF CIRRUS SPREADING OVER THE AREA. DESPITE THIS
CIRRUS...SOME OF WHICH APPEARS TO BE RATHER THICK...TEMPERATURES
CONTINUE TO CLIMB WITH WIDESPREAD MID 90S INLAND. DEWPOINTS ACROSS
WESTERN AREAS ARE TRENDING DOWN AS DRY AIR IS MIXED INTO THE
BOUNDARY LAYER. THIS SHOULD KEEP HEAT INDEX VALUES JUST BELOW HEAT
ADVISORY CRITERIA THROUGH THE REST OF THE AFTERNOON. FARTHER EAST
THE COMBINATION OF HIGHER RECENT RAINFALL AND ONSHORE FLOW IS
KEEPING DEWPOINTS A LITTLE HIGHER...RESULTING IN HEAT INDEX VALUES
ALREADY APPROACHING...AND IN SOME CASES EXCEEDING...105 DEGREES.
HIGH RESOLUTION SHORT TERM GUIDANCE STILL EXPECTING ISOLATED
CONVECTION ALONG THE SEA BREEZE/PIEDMONT TROUGH THIS AFTERNOON.
MLCAPE WILL APPROACH 3000 J/KG DURING THE AFTERNOON BUT THE
UNFAVORABLE ENVIRONMENT IS A BIG OBSTACLE TO OVERCOME. HAVE HELD
ONTO SLIGHT CHC POP FOR THE AFTERNOON/EVENING HOURS GIVEN TEMPS IN
THE MID TO UPPER 90S AND DEWPOINTS IN SOME AREAS IN THE MID 70S.
ANY CONVECTION THAT DOES DEVELOP THIS AFTERNOON WILL NOT LAST MUCH
BEYOND SUNSET GIVEN THE LACK OF MID LEVEL SUPPORT. ALTHOUGH
LINGERING CU AND EVEN DEBRIS CLOUD IS LIKELY TO BE GONE BY
MIDNIGHT CIRRUS WILL CONTINUE TO STREAM IN FROM THE WEST AS
PROGRESSIVE MID LEVEL FLOW SPREADS CONVECTIVE CIRRUS BLOW OFF
EAST. PATCHY FOG MAY DEVELOP LATE IN THE PERIOD BUT VISIBILITIES
SHOULD REMAIN ABOVE 3SM IN MOST AREAS. LOWS WILL BE ABOVE
CLIMO...MID 70S IN MOST AREAS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 211 PM WEDNESDAY...PRIMARY WEATHER HEADLINE ARE PROSPECTS
OF RAINFALL ACROSS THE REGION LATE THURSDAY...ESPECIALLY THROUGH
FRIDAY...AS A QUASI-STATIONARY SURFACE LOW PRESSURE ENTITY ALONG
THE COASTAL INTERIOR THURSDAY...EJECTS TO SEA FRIDAY. A FRONTAL
PASSAGE WILL ACCOMPANY THIS MIGRATION OFFSHORE FRIDAY NIGHT.
SATELLITE DATA SHOWS AN AXIS OF HIGH PRECIPITABLE WATER BETWEEN
1.85 AND 2.10 INCHES POSITIONED ACROSS THE GULF STATES AND THE
COASTAL CAROLINAS...AVAILABLE FOR INGEST BY A LOW PRESSURE
FEATURE. A MARGINAL RISK REMAINS INTACT FRIDAY ACROSS THE AREA AS
A MID-LVL TROUGH TRAVERSES THE REGION. A COOLING TREND SHOULD BE
IN THE OFFERING EACH DAY THU/FRI...AS MOIST ONSHORE WINDS AND
CLOUDS TEAM...AND POTENTIALLY RAIN-COOLED AIR FRIDAY.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 3 AM WEDNESDAY... ANY COOL AND DRY ADVECTION BEHIND THE
SHORT TERM FRONT WILL BE SHORT LIVED AS IT SEEMS THAT MOISTURE
RETURN WANTS TO GET UNDERWAY ALREADY BY SUNDAY. SOME MODELS WANT
TO BRING SOME RAIN BACK INTO THE PICTURE BUT GIVEN THE BUILDING
HEIGHTS ALOFT ASSOCIATED WITH A RIDGE TO OUR WEST THIS MAY BE
OVERDONE EARLY ON. TOWARDS THE END OF THE PERIOD HOWEVER ANOTHER
TROUGH AND FRONT WILL BE APPROACHING AND RAIN CHANCES SHOULD RAMP
UP.
&&
.AVIATION /18Z WEDNESDAY THROUGH SUNDAY/...
AS OF 18Z...BOTH THE WRF AND THE HRRR DEPICT CONVECTION THIS
AFTERNOON ALONG THE SEA BREEZE BOUNDARY. IF CONVECTION DOES MANAGE
TO GET GOING...THE STEERING FLOW WILL MOVE THE STORMS TO THE
SOUTHEAST...KEEPING THEM ALONG THE COAST. THE BEST CHANCE WILL BE
PENDER AND NEW HANOVER COUNTIES...WHERE THE ANGLE SEA BREEZE
BOUNDARIES OVERLAP. LIGHT SOUTHWEST FLOW THROUGH THE FORECAST
PERIOD...MORE SOUTHERLY BY LATE AFTERNOON ALONG THE COAST. SOME
LIGHT MORNING FOG POSSIBLE ON THURSDAY.
EXTENDED OUTLOOK...INCREASING CHANCES FOR CONVECTION THURSDAY NIGHT
THROUGH FRIDAY WITH THE APPROACH OF A COLD FRONT. HIGH PRESSURE WILL
NOSE IN FROM THE NORTH SATURDAY AND SUNDAY. CHANCE FOR STORMS
MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 211 PM WEDNESDAY...GRADIENT REMAINS RELATIVELY WEAK OVER
THE WATERS THIS AFTERNOON. SEA BREEZE HAS DEVELOPED AND RESULTED
IN SLIGHTLY ENHANCE ONSHORE FLOW AT THE COAST BUT HAS HAD LIMITED
EFFECT ACROSS THE BULK OF THE MARINE ZONES. SOUTHWEST FLOW 10 TO
15 KT WILL CONTINUE THROUGH THE AFTERNOON HOURS AND OVERNIGHT.
GUST MAY OCCASIONALLY HIT 20 KT BUT OCCURRENCES WILL BE
INFREQUENT. SEAS RUN 2 TO 4 FT WITH AN ISOLATED 5 FT POSSIBLE IN
EASTERN AND SOUTHERN ENDS OF AMZ252 AND AMZ250 RESPECTIVELY.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 211 PM WEDNESDAY...NEARLY THE ENTIRETY OF THIS PERIOD WILL
BE MARKED BY AN ELONGATED SURFACE LOW PRESSURE AXIS
INLAND...ORIENTED WSW-ENE ACROSS THE COASTAL INTERIOR OF NE SC AND
SE NC. WOBBLES AND FLUCTUATIONS WITH THIS FEATURES WILL BRING
VARYING WINDSPEEDS BETWEEN 10-20 KNOTS...BUT IN GENERAL A
CONSISTENT SW DIRECTION. SEAS THIS PERIOD WILL BE COMPOSED OF ESE
WAVES AROUND 2 FT EVERY 9-10 SECONDS AND SHORTER PERIOD...LOCALLY
DERIVED WIND-WAVES OF SSW 1-3 FT EVERY 4-5 SECONDS. TSTMS OVER THE
WATERS WILL SEE A NOTABLE INCREASE LATE THURSDAY NIGHT THROUGH
FRIDAY...AS A LOW PRESSURE AREA IS KICKED OFFSHORE AND A FRONTAL
BOUNDARY CROSSES THE 0-20 NM WATERS FRIDAY.
LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 3 AM WEDNESDAY... THE FRONTAL PASSAGE DURING THE SHORT TERM
PERIOD LEAVES BEHIND A VERY WEAK GRADIENT OVER THE WEEKEND.
PINNING DOWN A WIND DIRECTION AT THIS TIME IS RATHER TRICKY BUT
WIND SPEEDS WILL ALMOST BE CERTAINLY BE CAPPED AT 10 KTS. SEAS
WILL THUSLY SETTLE TO NEAR MINIMAL VALUES FOR THE OCEAN AT 2 FT OR
LESS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR SCZ032-033-039-
053>056.
NC...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR NCZ099-105>110.
MARINE...NONE.
&&
$$
SYNOPSIS...MJC
NEAR TERM...III
SHORT TERM...MJC
LONG TERM...MBB
AVIATION...DL/III
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
201 PM EDT WED AUG 5 2015
.SYNOPSIS...
TEMPERATURES ABOVE NORMAL TODAY AND THURSDAY. ISOLATED
THUNDERSTORMS EXPECTED THIS AFTERNOON WITH AN INCREASE IN COVERAGE
ANTICIPATED ON THURSDAY. AN AREA OF LOW PRESSURE AND ITS
ASSOCIATED COLD FRONT WILL APPROACH THE AREA FROM THE WEST LATE
THURSDAY AND MOVE ACROSS THE AREA FRIDAY INTO FRIDAY NIGHT. WEAK
HIGH PRESSURE IS EXPECTED TO FOLLOW SATURDAY THROUGH MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 2 PM WEDNESDAY...THUS FAR DEEP CONVECTION HAS BEEN HELD OFF
BY SUBSIDENCE AND MID LEVEL DRY AIR. VISIBLE SATELLITE SO FAR IS
NOT EVEN SHOWING MUCH OF A CU FIELD...ALTHOUGH THERE IS AN
ABUNDANCE OF CIRRUS SPREADING OVER THE AREA. DESPITE THIS
CIRRUS...SOME OF WHICH APPEARS TO BE RATHER THICK...TEMPERATURES
CONTINUE TO CLIMB WITH WIDESPREAD MID 90S INLAND. DEWPOINTS ACROSS
WESTERN AREAS ARE TRENDING DOWN AS DRY AIR IS MIXED INTO THE
BOUNDARY LAYER. THIS SHOULD KEEP HEAT INDEX VALUES JUST BELOW HEAT
ADVISORY CRITERIA THROUGH THE REST OF THE AFTERNOON. FARTHER
EAST THE COMBINATION OF HIGHER RECENT RAINFALL AND ONSHORE FLOW IS
KEEPING DEWPOINTS A LITTLE HIGHER...RESULTING IN HEAT INDEX VALUES
ALREADY APPROACHING...AND IN SOME CASES EXCEEDING...105 DEGREES.
HIGH RESOLUTION SHORT TERM GUIDANCE STILL EXPECTING ISOLATED
CONVECTION ALONG THE SEA BREEZE/PIEDMONT TROUGH THIS AFTERNOON.
MLCAPE WILL APPROACH 3000 J/KG DURING THE AFTERNOON BUT THE
UNFAVORABLE ENVIRONMENT IS A BIG OBSTACLE TO OVERCOME. HAVE HELD
ONTO SLIGHT CHC POP FOR THE AFTERNOON/EVENING HOURS GIVEN TEMPS IN
THE MID TO UPPER 90S AND DEWPOINTS IN SOME AREAS IN THE MID 70S.
ANY CONVECTION THAT DOES DEVELOP THIS AFTERNOON WILL NOT LAST MUCH
BEYOND SUNSET GIVEN THE LACK OF MID LEVEL SUPPORT. ALTHOUGH
LINGERING CU AND EVEN DEBRIS CLOUD IS LIKELY TO BE GONE BY
MIDNIGHT CIRRUS WILL CONTINUE TO STREAM IN FROM THE WEST AS
PROGRESSIVE MID LEVEL FLOW SPREADS CONVECTIVE CIRRUS BLOW OFF
EAST. PATCHY FOG MAY DEVELOP LATE IN THE PERIOD BUT VISIBILITIES
SHOULD REMAIN ABOVE 3SM IN MOST AREAS. LOWS WILL BE ABOVE
CLIMO...MID 70S IN MOST AREAS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 AM WEDNESDAY... A COLD FRONT AND STRONG UPPER TROUGH WILL BE
BEARING DOWN ON THE AREA ON THURSDAY. THE STAGE MAY BE SET FOR
SEVERE THUNDERSTORMS THOUGH THE STRONGEST FORCING COMES OVERNIGHT AT
WHICH TIME THE INSTABILITY WILL HAVE WANED. MOST LOCALES SHOULD END
UP WITH SOME NEEDED RAINFALL ESPECIALLY IF SOME ELEVATED
INSTABILITY REMAINS AS THE FORCING LOOKS QUITE STRONG. WITH THE
FRONT SLOWING DOWN AS IT PUSHES THROUGH FRIDAY MAY ALSO BE QUITE
UNSETTLED ESPECIALLY EARLIER IN THE DAY. LOW LEVEL DRY AIR SHOULD
PUSH IN FRIDAY NIGHT THOUGH ANOTHER FAIRLY HEALTHY IMPULSE ALOFT
WILL KEEP SOME LOW RAIN CHANCES IN THE FORECAST.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 3 PM WEDNESDAY... ANY COOL AND DRY ADVECTION BEHIND THE SHORT
TERM FRONT WILL BE SHORT LIVED AS IT SEEMS THAT MOISTURE RETURN
WANTS TO GET UNDERWAY ALREADY BY SUNDAY. SOME MODELS WANT TO BRING
SOME RAIN BACK INTO THE PICTURE BUT GIVEN THE BUILDING HEIGHTS ALOFT
ASSOCIATED WITH A RIDGE TO OUR WEST THIS MAY BE OVERDONE EARLY ON.
TOWARDS THE END OF THE PERIOD HOWEVER ANOTHER TROUGH AND FRONT WILL
BE APPROACHING AND RAIN CHANCES SHOULD RAMP UP.
&&
.AVIATION /17Z WEDNESDAY THROUGH SUNDAY/...
AS OF 18Z...BOTH THE WRF AND THE HRRR DEPICT CONVECTION THIS
AFTERNOON ALONG THE SEA BREEZE BOUNDARY. IF CONVECTION DOES MANAGE
TO GET GOING...THE STEERING FLOW WILL MOVE THE STORMS TO THE
SOUTHEAST...KEEPING THEM ALONG THE COAST. THE BEST CHANCE WILL BE
PENDER AND NEW HANOVER COUNTIES...WHERE THE ANGLE SEA BREEZE
BOUNDARIES OVERLAP. LIGHT SOUTHWEST FLOW THROUGH THE FORECAST
PERIOD...MORE SOUTHERLY BY LATE AFTERNOON ALONG THE COAST. SOME
LIGHT MORNING FOG POSSIBLE ON THURSDAY.
EXTENDED OUTLOOK...INCREASING CHANCES FOR CONVECTION THURSDAY NIGHT
THROUGH FRIDAY WITH THE APPROACH OF A COLD FRONT. HIGH PRESSURE WILL
NOSE IN FROM THE NORTH SATURDAY AND SUNDAY. CHANCE FOR STORMS
MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 2 PM WEDNESDAY...GRADIENT REMAINS RELATIVELY WEAK OVER THE
WATERS THIS AFTERNOON. SEA BREEZE HAS DEVELOPED AND RESULTED IN
SLIGHTLY ENHANCE ONSHORE FLOW AT THE COAST BUT HAS HAD LIMITED
EFFECT ACROSS THE BULK OF THE MARINE ZONES. SOUTHWEST FLOW 10 TO
15 KT WILL CONTINUE THROUGH THE AFTERNOON HOURS AND OVERNIGHT.
GUST MAY OCCASIONALLY HIT 20 KT BUT OCCURRENCES WILL BE
INFREQUENT. SEAS RUN 2 TO 4 FT WITH AN ISOLATED 5 FT POSSIBLE
IN EASTERN AND SOUTHERN ENDS OF AMZ252 AND AMZ250 RESPECTIVELY.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 AM WEDNESDAY... WIND AND SEAS BUILDING AHEAD OF A COLD
FRONT AND FAIRLY STRONG UPPER LOW ON THURSDAY. WE MAY GET CLOSE TO
ADVISORY CRITERIA BUT LATEST GUIDANCE KEEPS SUCH CONDITIONS JUST
OUTSIDE OF THE FORECAST ZONES. THE BOUNDARY DROPS INTO THE AREA ON
FRIDAY BUT ITS DECELERATING NATURE WILL NOT MAKE FOR THE CLEANEST
OF FROPAS OVER THE WATERS. WINDS AND SEAS WILL SLACKEN AS A RESULT
AND SOME SLIGHT PREFRONTAL VEERING MAY OCCUR. THE SHARPER WIND
SHIFT THEN COMES FRIDAY NIGHT AND WAVES MAY STEEPEN EVEN AS
OVERALL DOMINANT WAVE HEIGHT CONTINUES TO DROP OFF.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 3 PM WEDNESDAY... THE FRONTAL PASSAGE DURING THE SHORT TERM
PERIOD LEAVES BEHIND A VERY WEAK GRADIENT OVER THE WEEKEND.
PINNING DOWN A WIND DIRECTION AT THIS TIME IS RATHER TRICKY BUT
WIND SPEEDS WILL ALMOST BE CERTAINLY BE CAPPED AT 10 KTS. SEAS
WILL THUSLY SETTLE TO
NEAR MINIMAL VALUES FOR THE OCEAN AT 2 FT OR
LESS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR SCZ032-033-039-
053>056.
NC...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR NCZ099-105>110.
MARINE...NONE.
&&
$$
NEAR TERM...III
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...DL
AREA FORECAST DISCUSSION
NWS BISMARCK ND
940 PM CDT THU AUG 6 2015
.UPDATE...
ISSUED AT 928 PM CDT THU AUG 6 2015
ISOLATED THUNDERSTORMS FORMING ALONG A COLD FRONT ACROSS
NORTHWEST NORTH DAKOTA IN DIVIDE COUNTY. THIS MAY LAST A FEW
HOURS..AT LEAST THROUGH MIDNIGHT. FOLLOWING THE FRONT INTO
MONTANA THERE APPEARS TO BE SOME SUPPORT FROM THE H300 JET FOR
SOME SHOWERS LATE TONIGHT SOUTHWEST. ADDED SLIGHT CHANCE ALONG THE
NORTHWEST CANADIAN BORDER TONIGHT AND ALONG THE SOUTHWEST SOUTH
DAKOTA BORDER LATE AS WELL. HRRR SUGGESTS SOME PATCHY FOG TONIGHT
CENTRAL AND EAST. ADDED FOG AFTER MIDNIGHT.
UPDATE ISSUED AT 737 PM CDT THU AUG 6 2015
RADAR AND SATELLITE DATA SHOW THE MAIN AREA OF PRECIPITATION IS
EXITING THE REGION. WILL CANCEL THE FLASH FLOOD WATCH. THIS WILL
END THE PRECIPITATION FOR TONIGHT EAST.
COLD FRONT ASSOCIATED WITH THE MAIN LOW LAGS BACK IN EASTERN
MONTANA. WITH LIMITED SUPPORT ALOFT WILL NOT ADD POPS TO THE
SOUTHWEST AT THIS TIME. BUT ACROSS THE NORTHWEST A BAND OF
SHOWERS AND ISOLATED THUNDERSTORMS MAY LINGER THROUGH THE EVENING
ACROSS THE NORTHWEST. WILL WATCH THE HRRR TRENDS FOR THE AFTER
MIDNIGHT PERIOD.
UPDATE ISSUED AT 534 PM CDT THU AUG 6 2015
CANCELED THE FLASH FLOOD WATCH FOR ALL BUT THE JAMES RIVER
VALLEY.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 250 PM CDT THU AUG 6 2015
HEAVY RAINFALL POTENTIAL THROUGH EARLY THIS EVENING SOUTH CENTRAL
AND INTO THE JAMES RIVER VALLEY HIGHLIGHTS THE SHORT TERM
FORECAST.
THE FLASH FLOOD WATCH FOR THE SOUTH CENTRAL AND JAMES RIVER VALLEY
REMAINS IN EFFECT UNTIL 10 PM CDT THIS EVENING. RADAR TRENDS
THROUGH 20 UTC DEPICT NUMEROUS SLOWING MOVING...WARM RAIN PROCESS
DOMINATED STORMS ACROSS THE AFOREMENTIONED AREAS. GIVEN TRENDS IN
THE 17-19 UTC HRRR ITERATIONS WHICH HAVE OVERALL HANDLED THE EVENT
WELL...EXPECT ACTIVITY TO BEGIN TO WANE/PROPAGATE EAST INTO THE
RED RIVER VALLEY BY 23-00 UTC. FURTHER WEST NEAR THE OCCLUDED
FRONTAL BOUNDARY FROM NORTHEAST MONTANA THROUGH LAKE
OAHE...DIURNALLY DRIVEN ISOLATED CONVECTION IS EXPECTED.
HOWEVER...SEVERE WEATHER IS NOT ANTICIPATED.
GIVEN GOOD AGREEMENT ON THE 12 UTC DETERMINISTIC SUITE...A DRY
COLD FRONTAL PASSAGE IS EXPECTED ON FRIDAY...WITH SEASONABLE
TEMPERATURES AND MOSTLY SUNNY SKIES.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 250 PM CDT THU AUG 6 2015
A POTENTIAL WARM UP NEXT WEEK HIGHLIGHTS THE EXTENDED FORECAST.
THE 12 UTC GUIDANCE SUITE IS IN AGREEMENT ON QUASI-ZONAL THIS
WEEKEND AMPLIFYING EARLY NEXT WEEK AS AN INTERMOUNTAIN
WEST/CENTRAL CONUS UPPER LEVEL RIDGE BUILDS. THIS SUPPORTS A
POSSIBLE TRANSITION FROM NEAR NORMAL TEMPERATURES THIS
WEEKEND...WARMING THROUGH NEXT WEEK. GIVEN WEAK WAVES EMBEDDED IN THE
FAST QUASI-ZONAL FLOW THIS WEEKEND...DAILY CHANCES FOR
THUNDERSTORMS ARE FORECAST SATURDAY AND SUNDAY GENERALLY SOUTH OF
ND HIGHWAY 200. SEVERE THUNDERSTORMS ARE NOT EXPECTED.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 928 PM CDT THU AUG 6 2015
AT 9 PM CDT...A COLD FRONT EXTENDED FROM LOW PRESSURE IN
SASKATCHEWAN INTO WESTERN NORTH DAKOTA. THE FRONT WILL BE THE
FOCUS FOR ISOLATED SHOWERS AND THUNDERSTORMS NORTHWEST THIS
EVENING AND ISOLATED SHOWERS SOUTHWEST AFTER MIDNIGHT. AT THIS
TIME TOO UNCERTAIN TO INCLUDE THIS IN TAFS. SHORT RANGE MODELS
HINTING AT FOG ACROSS THE CENTRAL AND EAST. THIS SEEMS PLAUSIBLE
DUE TO RAINFALL. WILL CONSIDER ADDING F/BR TO TAFS FOR THE 06Z
ISSUANCE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...WAA
SHORT TERM...AYD
LONG TERM...AYD
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
746 PM CDT THU AUG 6 2015
.UPDATE...
ISSUED AT 737 PM CDT THU AUG 6 2015
RADAR AND SATELLITE DATA SHOW THE MAIN AREA OF PRECIPITATION IS
EXITING THE REGION. WILL CANCEL THE FLASH FLOOD WATCH. THIS WILL
END THE PRECIPITATION FOR TONIGHT EAST.
COLD FRONT ASSOCIATED WITH THE MAIN LOW LAGS BACK IN EASTERN
MONTANA. WITH LIMITED SUPPORT ALOFT WILL NOT ADD POPS TO THE
SOUTHWEST AT THIS TIME. BUT ACROSS THE NORTHWEST A BAND OF
SHOWERS AND ISOLATED THUNDERSTORMS MAY LINGER THROUGH THE EVENING
ACROSS THE NORTHWEST. WILL WATCH THE HRRR TRENDS FOR THE AFTER
MIDNIGHT PERIOD.
UPDATE ISSUED AT 534 PM CDT THU AUG 6 2015
CANCELED THE FLASH FLOOD WATCH FOR ALL BUT THE JAMES RIVER
VALLEY.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 250 PM CDT THU AUG 6 2015
HEAVY RAINFALL POTENTIAL THROUGH EARLY THIS EVENING SOUTH CENTRAL
AND INTO THE JAMES RIVER VALLEY HIGHLIGHTS THE SHORT TERM
FORECAST.
THE FLASH FLOOD WATCH FOR THE SOUTH CENTRAL AND JAMES RIVER VALLEY
REMAINS IN EFFECT UNTIL 10 PM CDT THIS EVENING. RADAR TRENDS
THROUGH 20 UTC DEPICT NUMEROUS SLOWING MOVING...WARM RAIN PROCESS
DOMINATED STORMS ACROSS THE AFOREMENTIONED AREAS. GIVEN TRENDS IN
THE 17-19 UTC HRRR ITERATIONS WHICH HAVE OVERALL HANDLED THE EVENT
WELL...EXPECT ACTIVITY TO BEGIN TO WANE/PROPAGATE EAST INTO THE
RED RIVER VALLEY BY 23-00 UTC. FURTHER WEST NEAR THE OCCLUDED
FRONTAL BOUNDARY FROM NORTHEAST MONTANA THROUGH LAKE
OAHE...DIURNALLY DRIVEN ISOLATED CONVECTION IS EXPECTED.
HOWEVER...SEVERE WEATHER IS NOT ANTICIPATED.
GIVEN GOOD AGREEMENT ON THE 12 UTC DETERMINISTIC SUITE...A DRY
COLD FRONTAL PASSAGE IS EXPECTED ON FRIDAY...WITH SEASONABLE
TEMPERATURES AND MOSTLY SUNNY SKIES.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 250 PM CDT THU AUG 6 2015
A POTENTIAL WARM UP NEXT WEEK HIGHLIGHTS THE EXTENDED FORECAST.
THE 12 UTC GUIDANCE SUITE IS IN AGREEMENT ON QUASI-ZONAL THIS
WEEKEND AMPLIFYING EARLY NEXT WEEK AS AN INTERMOUNTAIN
WEST/CENTRAL CONUS UPPER LEVEL RIDGE BUILDS. THIS SUPPORTS A
POSSIBLE TRANSITION FROM NEAR NORMAL TEMPERATURES THIS
WEEKEND...WARMING THROUGH NEXT WEEK. GIVEN WEAK WAVES EMBEDDED IN THE
FAST QUASI-ZONAL FLOW THIS WEEKEND...DAILY CHANCES FOR
THUNDERSTORMS ARE FORECAST SATURDAY AND SUNDAY GENERALLY SOUTH OF
ND HIGHWAY 200. SEVERE THUNDERSTORMS ARE NOT EXPECTED.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 737 PM CDT THU AUG 6 2015
AT 7 AM CDT...A COLD FRONT EXTENDED ACROSS EASTERN MONTANA. LOW
PRESSURE ACROSS EASTERN NORTH DAKOTA WAS MOVING EAST. CURRENT
TRENDS INDICATE ISOLATED THUNDERSTORMS MAY TRACK ACROSS THE
CANADIAN BORDER WEST OF MINOT. TO ISOLATED TO INCLUDE IN THE
KMOT- KISN TAFS. VFR.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...WAA
SHORT TERM...AYD
LONG TERM...AYD
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
313 PM CDT WED AUG 5 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 302 PM CDT WED AUG 5 2015
HIGHLIGHTS OF THE SHORT TERM IS CONVECTIVE POTENTIAL THIS
AFTERNOON AND HEAVY RAINFALL ON THURSDAY.
FOR THE REMAINDER OF THE AFTERNOON...EXPECTING ISOLATED TO
SCATTERED SURFACE BASED CONVECTIVE DEVELOPMENT EAST OF THE WARM
FRONT NEAR US HIGHWAY 85. 18 UTC RAP ANALYSIS DEPICTS 1500-2000
J/KG OF ML CAPE AND DEEP LAYER SHEAR OF 30-40 KTS AHEAD OF THE
BOUNDARY. THUS...A FEW STRONG TO POSSIBLY SEVERE STORMS ARE
POSSIBLE...IN LINE WITH THE 18-19 UTC HRRR ITERATIONS AND SPC DAY
1 OUTLOOK.
A STRONG SHORTWAVE IS FORECAST TO PROPAGATE OUT OF THE
INTERMOUNTAIN WEST AND ONTO THE NORTHERN PLAINS LATE THIS EVENING
AND TONIGHT...AND STRENGTHEN THROUGH THE DAY ON THURSDAY.
EXPECTING WIDESPREAD THUNDERSTORMS SOUTH OF US HIGHWAY 2 ENTERING
THE SOUTHWEST TONIGHT...AND FOCUSING CENTRAL THROUGH THURSDAY
AFTERNOON. PWATS OF 1.50 TO 1.75 INCHES WITH TALL...SKINNY CAPE
PROFILES...AND WEAK WINDS THROUGHOUT THE TROPOSPHERE SUPPORTING
SLOW STORM MOTIONS ALL POINT TO A HEAVY RAINFALL THREAT. AREAS
THAT WILL RESIDE IN THIS ENVIRONMENT THE LONGEST IS THE SOUTH
CENTRAL AND JAMES RIVER VALLEY LATE THURSDAY MORNING THROUGH THE
EVENING. THIS IS SUPPORTED BY 00 UTC GEFS QPF MODEL CLIMATE IN
THE MAXIMUM PERCENTILES FOR THESE AREAS THURSDAY AFTERNOON...WHICH
HAS BEEN NOTED AS A FLASH FLOOD SIGNAL IN PREVIOUS EVENTS ACROSS
THE CONUS. THUS...HAVE ISSUED A FLASH FLOOD WATCH FOR THE SOUTH
CENTRAL AND JAMES RIVER VALLEY FOR THURSDAY. ALTHOUGH SOME OF
THESE AREAS HAVE BEEN RELATIVELY DRY OVER THE RECENT
WEEKS...POTENTIAL EXCESSIVE RAINFALL RATES MAY STILL LEAD TO FLASH
FLOODING EVEN WITH DRY SOILS. FLASH FLOODING OF URBAN
AREAS...INCLUDING MANDAN...BISMARCK AND JAMESTOWN ARE ALSO
POSSIBLE WITH THESE SLOW MOVING...HEAVY RAINFALL PRODUCING STORMS.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 302 PM CDT WED AUG 5 2015
SHORTWAVE TROUGH WILL BE EXITING THE JAMES RIVER VALLEY THURSDAY
NIGHT/06-12 FRIDAY AS LIKELY POPS DWINDLE AND THE PRECIPITATION COMES
TO AN END. UPPER LOW WILL MOVE ACROSS SOUTHERN CANADA FRIDAY
THROUGH SATURDAY DRAGGING TWO SURFACE COLD FRONTS THROUGH...ONE
FRIDAY NIGHT AND A SECONDARY COLD FRONT SATURDAY. FRIDAY LOOKS DRY
WITH THE INITIAL FRONT. HOWEVER FRIDAY NIGHT AND
SATURDAY...ASSOCIATED WITH THE SECOND FRONT WILL BE THE RIGHT
ENTRANCE REGION OF A 70KT-80KT JET STREAK SLIDING THROUGH CENTRAL
NORTH DAKOTA ATOP OF A SURFACE LOW PRESSURE SCOOTING ACROSS
NORTHERN SOUTH DAKOTA. AN AREA OF PRECIPITATION DEVELOPS OVER OR
NEAR SOUTHERN NORTH DAKOTA SATURDAY IN RESPONSE TO THE LOW LEVEL
CONVERGENCE AND THE UPPER LEVEL DIVERGENCE AREA ASSOCIATED WITH
THE JET. ALTHOUGH WEAK NORTHWEST FLOW ENSUES SATURDAY NIGHT INTO
SUNDAY...THERE IS SOME QUESTION AS TO WHETHER OR NOT THE FRONT
STALLS ALONG/NEAR OR SOUTH OF THE SOUTHERN BORDER SUNDAY FOR
CONTINUED PRECIPITATION CHANCES. AS OF NOW IT APPEARS THAT CHANCES
FOR PRECIPITATION BEGIN ALONG INTERSTATE 94 AND INCREASE SOUTH
TOWARDS THE BORDER SUNDAY. THEREAFTER A CENTRAL CONUS UPPER LEVEL
RIDGE DEVELOPS WITH A TROUGH SETTLING INTO THE WEST FOR DRY AND
WARM CONDITIONS MONDAY AND TUESDAY. THERE MAY BE POTENTIAL
SHORTWAVES TRYING TO BREAK DOWN THE RIDGE BY MID WEEK OR SIGNS OF
THE RIDGE SHIFTING EAST A BIT FOR POSSIBLE SHOWERS AND
THUNDERSTORMS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 302 PM CDT WED AUG 5 2015
ISOLATED TO SCATTERED THUNDERSTORMS ARE POSSIBLE ACROSS CENTRAL
NORTH DAKOTA THIS AFTERNOON. ANOTHER STORM SYSTEM WILL BEGIN TO
IMPACT WESTERN NORTH DAKOTA TONIGHT...AND CONTINUE ACROSS ALL OF
WESTERN AND CENTRAL NORTH DAKOTA ON THURSDAY. WIDESPREAD
THUNDERSTORMS AND MVFR/IFR CONDITIONS ARE FORECAST TO DEVELOP.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM THURSDAY MORNING THROUGH THURSDAY EVENING
FOR NDZ019>023-025-034>037-042-045>048-050-051.
&&
$$
SHORT TERM...AYD
LONG TERM...KS
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
146 PM CDT WED AUG 5 2015
.UPDATE...
ISSUED AT 139 PM CDT WED AUG 5 2015
FOR THE REMAINDER OF THE AFTERNOON...EXPECTING ISOLATED TO
SCATTERED SURFACE BASED CONVECTIVE DEVELOPMENT EAST OF THE WARM
FRONT NEAR US HIGHWAY 85. 18 UTC RAP ANALYSIS DEPICTS 1500-2000
J/KG OF ML CAPE AND DEEP LAYER SHEAR OF 30-40 KTS AHEAD OF THE
BOUNDARY. THUS...A FEW STRONG TO POSSIBLY SEVERE STORMS ARE
POSSIBLE...IN LINE WITH THE 16-17 UTC HRRR ITERATIONS AND SPC DAY
1 OUTLOOK.
THEREAFTER...ATTENTION TURNS TO THE POTENTIAL HEAVY RAINFALL
THREAT FOR THURSDAY.
UPDATE ISSUED AT 908 AM CDT WED AUG 5 2015
QUICK UPDATE TO POPS FOR RADAR TRENDS THROUGH 14 UTC...BLENDED TO
A TIME LAGGED ENSEMBLE OF THE 10-12 UTC HRRR ITERATIONS WHICH HAS
A GOOD HANDLE ON THE ONGOING CONVECTION. EXPECT CURRENT STORMS TO
AT LEAST MAINTAIN THEMSELVES AS THEY PROPAGATE EAST WITH THE
UPPER LEVEL SHORTWAVE. GIVEN THE CLEARING AHEAD OF THESE STORMS
INTO THE JAMES RIVER VALLEY...DESTABILIZATION INTO THE EARLY
AFTERNOON MAY LEAD TO STORM INTENSIFICATION AND A FEW STORMS
APPROACHING SEVERE LIMITS WITH ML CAPE NEAR 1500 J/KG AND DEEP
LAYER SHEAR OF 30-40 KTS.
UPDATE ISSUED AT 623 AM CDT WED AUG 5 2015
UPDATED TO INCREASE POPS ALONG THE LINE OF SHOWERS AND
THUNDERSTORMS MOVING ACROSS WESTERN AND CENTRAL NORTH DAKOTA.
LEANED HEAVILY ON A BLEND OF THE LATEST HRRR AND RAP FOR POPS. A
FEW OF THE STORMS IN SOUTHERN PARTS OF THE FORECAST AREA HAVE
PULSED UP FROM TIME TO TIME...BUT INSTABILITY AND SHEAR ARE STILL
RELATIVELY LIMITED THIS MORNING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 324 AM CDT WED AUG 5 2015
TIMING AND PRECIP CHANCES/AREAL COVERAGE OF SHOWERS AND
THUNDERSTORMS TODAY AND TONIGHT ARE THE MAIN CHALLENGES IN TODAY`S
SHORT TERM PERIOD.
CURRENTLY...AN AREA OF SHOWERS AND THUNDERSTORMS CONTINUED OVER
SOUTHWESTERN NORTH DAKOTA AND NORTHEASTERN MONTANA...THOUGH THE
INTENSITY OF SHOWERS AND THUNDERSTORMS HAS WANED WITH TIME EARLY
THIS MORNING. THE CONVECTION WAS ASSOCIATED WITH AN UPPER LEVEL
SHORTWAVE THAT IS FORECAST TO CONTINUE MOVING EASTWARD SLOWLY
ACROSS THE STATE TODAY.
THE LATEST ITERATIONS OF THE HRRR AND NAM SUGGEST THAT THE AREA OF
CONVECTION WILL STILL BE IN WESTERN NORTH DAKOTA BUT APPROACHING
CENTRAL NORTH DAKOTA BY DAYBREAK TODAY. THE LATEST HRRR SUGGESTS THE
CONVECTION WOULD BEGIN INCREASING IN INTENSITY BEFORE NOON OVER
CENTRAL NORTH DAKOTA...IN A WIDE LINE OF CONVECTION EXTENDING FROM
WESTERN MANITOBA TO MINOT TO BISMARCK BEFORE NOON. THE MODELS
SUGGEST THAT THE TURTLE MOUNTAINS AND JAMES VALLEY AND EASTWARD WILL
BE THE FAVORED AREA FOR CONVECTION DURING THE AFTERNOON.
CAPE AND SHEAR VALUES ARE MODEST THIS AFTERNOON IN CENTRAL NORTH
DAKOTA...THUS A FEW STORMS COULD BE ON THE STRONG SIDE...BUT
INGREDIENTS ARE NOT FAVORABLE FOR A MENTION OF A SEVERE THREAT.
ATTENTION THEN TURNS WESTWARD. WEDNESDAY MORNING AND AFTERNOON A
RATHER POTENT SERIES OF UPPER LEVEL IMPULSES EMERGING FROM A TROUGH
OVER THE WEST COAST MOVES EASTWARD ACROSS MONTANA/WYOMING. THESE
UPPER LEVEL IMPULSES ENTER THE WESTERN DAKOTAS LATE THIS AFTERNOON
OR EARLY EVENING (MODELS DIFFER ON TIMING)...AND EXPAND EASTWARD
ACROSS THE STATE TONIGHT. PRECIPITATION CHANCES FOR THIS EVENING
BEGIN IN THE WEST BY MID-EVENING...SPREADING EAST INTO CENTRAL NORTH
DAKOTA AFTER MIDNIGHT.
THE BEST CAPE AND SHEAR WITH THIS POTENT WAVE APPEARS TO BE
FARTHER SOUTH INTO SOUTH DAKOTA AND NEBRASKA...BUT THE MODEST
VALUES IN NORTH DAKOTA COULD BE ENOUGH FOR A FEW OF THE STORMS TO
BE ON THE STRONG SIDE.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 324 AM CDT WED AUG 5 2015
THE LONG TERM PERIOD BEGINS THURSDAY WITH SHOWERS AND THUNDERSTORMS
ACROSS EASTERN MONTANA / WESTERN NORTH DAKOTA MOVING THEIR WAY
EAST DURING THE DAY. THESE ARE IN RESPONSE TO AN H5 WAVE AND
UPPER LEVEL JET STREAK MOVING ACROSS THE NORTHERN PLAINS. THE
DETERMINISTIC MODELS HAVE COME INTO FAIRLY GOOD AGREEMENT IN THIS
SCENARIO...SO WILL CARRY LIKELY POPS FROM NORTHWEST NORTH
DAKOTA...THROUGH THE CENTRAL PART OF THE STATE AND TOWARDS THE
SOUTHERN JAMES RIVER VALLEY. THE DAY 2 CONVECTIVE OUTLOOK FROM THE
STORM PREDICTION CENTER PLACES MUCH OF CENTRAL AND EASTERN NORTH
DAKOTA IN A MARGINAL RISK...AND THAT APPEARS REASONABLE WITH
SBCAPE VALUES OF 1500-2500...THOUGH SHEAR IS RATHER MARGINAL.
CONSIDERED GOING DRY FOR FRIDAY ACROSS ALL OF WESTERN AND CENTRAL
NORTH DAKOTA...BUT AFTER COLLABORATION WITH SURROUNDING OFFICES
OPTED TO KEEP A SLIGHT CHANCE OF THUNDERSTORMS IN THE FAR SOUTH.
THE 05.00Z GFS AND ECMWF BRING A SMALL CHANCE OF RAIN INTO THE
FAR SOUTH...WHILE THE NAM IS DRY.
RAIN CHANCES SHOULD INCREASE AGAIN SATURDAY NIGHT INTO SUNDAY AS
THE NEXT H5 WAVE MOVES ACROSS THE REGION. THE HIGHER RAIN CHANCES
ARE EXPECTED TO BE IN SOUTHERN PARTS OF THE FORECAST AREA...CLOSER
TO THE MORE ROBUST FORCING. AN UPPER RIDGE BUILDS INTO THE
NORTHERN PLAINS EARLY NEXT WEEK...WHICH WILL BRING DRIER WEATHER
TO WESTERN AND CENTRAL NORTH DAKOTA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 139 PM CDT WED AUG 5 2015
ISOLATED TO SCATTERED THUNDERSTORMS ARE POSSIBLE ACROSS CENTRAL
NORTH DAKOTA THIS AFTERNOON. ANOTHER STORM SYSTEM WILL BEGIN TO
IMPACT WESTERN NORTH DAKOTA TONIGHT...AND CONTINUE ACROSS ALL OF
WESTERN AND CENTRAL NORTH DAKOTA ON THURSDAY. WIDESPREAD
THUNDERSTORMS AND MVFR/IFR CONDITIONS ARE FORECAST TO DEVELOP.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...JV
LONG TERM...CK
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
914 AM CDT WED AUG 5 2015
.UPDATE...
ISSUED AT 908 AM CDT WED AUG 5 2015
QUICK UPDATE TO POPS FOR RADAR TRENDS THROUGH 14 UTC...BLENDED TO
A TIME LAGGED ENSEMBLE OF THE 10-12 UTC HRRR ITERATIONS WHICH HAS
A GOOD HANDLE ON THE ONGOING CONVECTION. EXPECT CURRENT STORMS TO
AT LEAST MAINTAIN THEMSELVES AS THEY PROPAGATE EAST WITH THE
UPPER LEVEL SHORTWAVE. GIVEN THE CLEARING AHEAD OF THESE STORMS
INTO THE JAMES RIVER VALLEY...DESTABILIZATION INTO THE EARLY
AFTERNOON MAY LEAD TO STORM INTENSIFICATION AND A FEW STORMS
APPROACHING SEVERE LIMITS WITH ML CAPE NEAR 1500 J/KG AND DEEP
LAYER SHEAR OF 30-40 KTS.
UPDATE ISSUED AT 623 AM CDT WED AUG 5 2015
UPDATED TO INCREASE POPS ALONG THE LINE OF SHOWERS AND
THUNDERSTORMS MOVING ACROSS WESTERN AND CENTRAL NORTH DAKOTA.
LEANED HEAVILY ON A BLEND OF THE LATEST HRRR AND RAP FOR POPS. A
FEW OF THE STORMS IN SOUTHERN PARTS OF THE FORECAST AREA HAVE
PULSED UP FROM TIME TO TIME...BUT INSTABILITY AND SHEAR ARE STILL
RELATIVELY LIMITED THIS MORNING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 324 AM CDT WED AUG 5 2015
TIMING AND PRECIP CHANCES/AREAL COVERAGE OF SHOWERS AND
THUNDERSTORMS TODAY AND TONIGHT ARE THE MAIN CHALLENGES IN TODAY`S
SHORT TERM PERIOD.
CURRENTLY...AN AREA OF SHOWERS AND THUNDERSTORMS CONTINUED OVER
SOUTHWESTERN NORTH DAKOTA AND NORTHEASTERN MONTANA...THOUGH THE
INTENSITY OF SHOWERS AND THUNDERSTORMS HAS WANED WITH TIME EARLY
THIS MORNING. THE CONVECTION WAS ASSOCIATED WITH AN UPPER LEVEL
SHORTWAVE THAT IS FORECAST TO CONTINUE MOVING EASTWARD SLOWLY
ACROSS THE STATE TODAY.
THE LATEST ITERATIONS OF THE HRRR AND NAM SUGGEST THAT THE AREA OF
CONVECTION WILL STILL BE IN WESTERN NORTH DAKOTA BUT APPROACHING
CENTRAL NORTH DAKOTA BY DAYBREAK TODAY. THE LATEST HRRR SUGGESTS THE
CONVECTION WOULD BEGIN INCREASING IN INTENSITY BEFORE NOON OVER
CENTRAL NORTH DAKOTA...IN A WIDE LINE OF CONVECTION EXTENDING FROM
WESTERN MANITOBA TO MINOT TO BISMARCK BEFORE NOON. THE MODELS
SUGGEST THAT THE TURTLE MOUNTAINS AND JAMES VALLEY AND EASTWARD WILL
BE THE FAVORED AREA FOR CONVECTION DURING THE AFTERNOON.
CAPE AND SHEAR VALUES ARE MODEST THIS AFTERNOON IN CENTRAL NORTH
DAKOTA...THUS A FEW STORMS COULD BE ON THE STRONG SIDE...BUT
INGREDIENTS ARE NOT FAVORABLE FOR A MENTION OF A SEVERE THREAT.
ATTENTION THEN TURNS WESTWARD. WEDNESDAY MORNING AND AFTERNOON A
RATHER POTENT SERIES OF UPPER LEVEL IMPULSES EMERGING FROM A TROUGH
OVER THE WEST COAST MOVES EASTWARD ACROSS MONTANA/WYOMING. THESE
UPPER LEVEL IMPULSES ENTER THE WESTERN DAKOTAS LATE THIS AFTERNOON
OR EARLY EVENING (MODELS DIFFER ON TIMING)...AND EXPAND EASTWARD
ACROSS THE STATE TONIGHT. PRECIPITATION CHANCES FOR THIS EVENING
BEGIN IN THE WEST BY MID-EVENING...SPREADING EAST INTO CENTRAL NORTH
DAKOTA AFTER MIDNIGHT.
THE BEST CAPE AND SHEAR WITH THIS POTENT WAVE APPEARS TO BE
FARTHER SOUTH INTO SOUTH DAKOTA AND NEBRASKA...BUT THE MODEST
VALUES IN NORTH DAKOTA COULD BE ENOUGH FOR A FEW OF THE STORMS TO
BE ON THE STRONG SIDE.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 324 AM CDT WED AUG 5 2015
THE LONG TERM PERIOD BEGINS THURSDAY WITH SHOWERS AND THUNDERSTORMS
ACROSS EASTERN MONTANA / WESTERN NORTH DAKOTA MOVING THEIR WAY
EAST DURING THE DAY. THESE ARE IN RESPONSE TO AN H5 WAVE AND
UPPER LEVEL JET STREAK MOVING ACROSS THE NORTHERN PLAINS. THE
DETERMINISTIC MODELS HAVE COME INTO FAIRLY GOOD AGREEMENT IN THIS
SCENARIO...SO WILL CARRY LIKELY POPS FROM NORTHWEST NORTH
DAKOTA...THROUGH THE CENTRAL PART OF THE STATE AND TOWARDS THE
SOUTHERN JAMES RIVER VALLEY. THE DAY 2 CONVECTIVE OUTLOOK FROM THE
STORM PREDICTION CENTER PLACES MUCH OF CENTRAL AND EASTERN NORTH
DAKOTA IN A MARGINAL RISK...AND THAT APPEARS REASONABLE WITH
SBCAPE VALUES OF 1500-2500...THOUGH SHEAR IS RATHER MARGINAL.
CONSIDERED GOING DRY FOR FRIDAY ACROSS ALL OF WESTERN AND CENTRAL
NORTH DAKOTA...BUT AFTER COLLABORATION WITH SURROUNDING OFFICES
OPTED TO KEEP A SLIGHT CHANCE OF THUNDERSTORMS IN THE FAR SOUTH.
THE 05.00Z GFS AND ECMWF BRING A SMALL CHANCE OF RAIN INTO THE
FAR SOUTH...WHILE THE NAM IS DRY.
RAIN CHANCES SHOULD INCREASE AGAIN SATURDAY NIGHT INTO SUNDAY AS
THE NEXT H5 WAVE MOVES ACROSS THE REGION. THE HIGHER RAIN CHANCES
ARE EXPECTED TO BE IN SOUTHERN PARTS OF THE FORECAST AREA...CLOSER
TO THE MORE ROBUST FORCING. AN UPPER RIDGE BUILDS INTO THE
NORTHERN PLAINS EARLY NEXT WEEK...WHICH WILL BRING DRIER WEATHER
TO WESTERN AND CENTRAL NORTH DAKOTA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 908 AM CDT WED AUG 5 2015
VFR CONDITIONS ARE EXPECTED THROUGH THE FORECAST PERIOD OUTSIDE OF
THUNDERSTORMS. AT 14Z...AN AREA OF SHOWERS AND THUNDERSTORMS
EXTENDED FROM KMOT THROUGH KBIS...AND WILL SLOWLY MOVE EAST
THROUGH THE DAY...APPROACHING KJMS BY 18-20 UTC.
THIS EVENING....ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS IS
EXPECTED TO MOVE INTO WESTERN NORTH DAKOTA MAINLY AFTER 23-00 UTC
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...JV
LONG TERM...CK
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
625 AM CDT WED AUG 5 2015
.UPDATE...
ISSUED AT 623 AM CDT WED AUG 5 2015
UPDATED TO INCREASE POPS ALONG THE LINE OF SHOWERS AND
THUNDERSTORMS MOVING ACROSS WESTERN AND CENTRAL NORTH DAKOTA.
LEANED HEAVILY ON A BLEND OF THE LATEST HRRR AND RAP FOR POPS. A
FEW OF THE STORMS IN SOUTHERN PARTS OF THE FORECAST AREA HAVE
PULSED UP FROM TIME TO TIME...BUT INSTABILITY AND SHEAR ARE STILL
RELATIVELY LIMITED THIS MORNING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 324 AM CDT WED AUG 5 2015
TIMING AND PRECIP CHANCES/AREAL COVERAGE OF SHOWERS AND
THUNDERSTORMS TODAY AND TONIGHT ARE THE MAIN CHALLENGES IN TODAY`S
SHORT TERM PERIOD.
CURRENTLY...AN AREA OF SHOWERS AND THUNDERSTORMS CONTINUED OVER
SOUTHWESTERN NORTH DAKOTA AND NORTHEASTERN MONTANA...THOUGH THE
INTENSITY OF SHOWERS AND THUNDERSTORMS HAS WANED WITH TIME EARLY
THIS MORNING. THE CONVECTION WAS ASSOCIATED WITH AN UPPER LEVEL
SHORTWAVE THAT IS FORECAST TO CONTINUE MOVING EASTWARD SLOWLY
ACROSS THE STATE TODAY.
THE LATEST ITERATIONS OF THE HRRR AND NAM SUGGEST THAT THE AREA OF
CONVECTION WILL STILL BE IN WESTERN NORTH DAKOTA BUT APPROACHING
CENTRAL NORTH DAKOTA BY DAYBREAK TODAY. THE LATEST HRRR SUGGESTS THE
CONVECTION WOULD BEGIN INCREASING IN INTENSITY BEFORE NOON OVER
CENTRAL NORTH DAKOTA...IN A WIDE LINE OF CONVECTION EXTENDING FROM
WESTERN MANITOBA TO MINOT TO BISMARCK BEFORE NOON. THE MODELS
SUGGEST THAT THE TURTLE MOUNTAINS AND JAMES VALLEY AND EASTWARD WILL
BE THE FAVORED AREA FOR CONVECTION DURING THE AFTERNOON.
CAPE AND SHEAR VALUES ARE MODEST THIS AFTERNOON IN CENTRAL NORTH
DAKOTA...THUS A FEW STORMS COULD BE ON THE STRONG SIDE...BUT
INGREDIENTS ARE NOT FAVORABLE FOR A MENTION OF A SEVERE THREAT.
ATTENTION THEN TURNS WESTWARD. WEDNESDAY MORNING AND AFTERNOON A
RATHER POTENT SERIES OF UPPER LEVEL IMPULSES EMERGING FROM A TROUGH
OVER THE WEST COAST MOVES EASTWARD ACROSS MONTANA/WYOMING. THESE
UPPER LEVEL IMPULSES ENTER THE WESTERN DAKOTAS LATE THIS AFTERNOON
OR EARLY EVENING (MODELS DIFFER ON TIMING)...AND EXPAND EASTWARD
ACROSS THE STATE TONIGHT. PRECIPITATION CHANCES FOR THIS EVENING
BEGIN IN THE WEST BY MID-EVENING...SPREADING EAST INTO CENTRAL NORTH
DAKOTA AFTER MIDNIGHT.
THE BEST CAPE AND SHEAR WITH THIS POTENT WAVE APPEARS TO BE
FARTHER SOUTH INTO SOUTH DAKOTA AND NEBRASKA...BUT THE MODEST
VALUES IN NORTH DAKOTA COULD BE ENOUGH FOR A FEW OF THE STORMS TO
BE ON THE STRONG SIDE.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 324 AM CDT WED AUG 5 2015
THE LONG TERM PERIOD BEGINS THURSDAY WITH SHOWERS AND THUNDERSTORMS
ACROSS EASTERN MONTANA / WESTERN NORTH DAKOTA MOVING THEIR WAY
EAST DURING THE DAY. THESE ARE IN RESPONSE TO AN H5 WAVE AND
UPPER LEVEL JET STREAK MOVING ACROSS THE NORTHERN PLAINS. THE
DETERMINISTIC MODELS HAVE COME INTO FAIRLY GOOD AGREEMENT IN THIS
SCENARIO...SO WILL CARRY LIKELY POPS FROM NORTHWEST NORTH
DAKOTA...THROUGH THE CENTRAL PART OF THE STATE AND TOWARDS THE
SOUTHERN JAMES RIVER VALLEY. THE DAY 2 CONVECTIVE OUTLOOK FROM THE
STORM PREDICTION CENTER PLACES MUCH OF CENTRAL AND EASTERN NORTH
DAKOTA IN A MARGINAL RISK...AND THAT APPEARS REASONABLE WITH
SBCAPE VALUES OF 1500-2500...THOUGH SHEAR IS RATHER MARGINAL.
CONSIDERED GOING DRY FOR FRIDAY ACROSS ALL OF WESTERN AND CENTRAL
NORTH DAKOTA...BUT AFTER COLLABORATION WITH SURROUNDING OFFICES
OPTED TO KEEP A SLIGHT CHANCE OF THUNDERSTORMS IN THE FAR SOUTH.
THE 05.00Z GFS AND ECMWF BRING A SMALL CHANCE OF RAIN INTO THE
FAR SOUTH...WHILE THE NAM IS DRY.
RAIN CHANCES SHOULD INCREASE AGAIN SATURDAY NIGHT INTO SUNDAY AS
THE NEXT H5 WAVE MOVES ACROSS THE REGION. THE HIGHER RAIN CHANCES
ARE EXPECTED TO BE IN SOUTHERN PARTS OF THE FORECAST AREA...CLOSER
TO THE MORE ROBUST FORCING. AN UPPER RIDGE BUILDS INTO THE
NORTHERN PLAINS EARLY NEXT WEEK...WHICH WILL BRING DRIER WEATHER
TO WESTERN AND CENTRAL NORTH DAKOTA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 623 AM CDT WED AUG 5 2015
VFR CONDITIONS ARE EXPECTED THROUGH THE FORECAST PERIOD OUTSIDE OF
THUNDERSTORMS. AT 11Z AN AREA OF SHOWERS EXTENDED FROM NEAR KISN
TO LAKE SAKAKAWEA...AND SOUTH TO NEW SALEM AND HETTINGER.
THUNDERSTORMS OCCURRING FROM NEW SALEM SOUTH AND SOUTHWEST TO
HETTINGER. THIS AREA OF CONVECTION IS FORECAST TO MOVE EASTWARD
SLOWLY TODAY. THIS WILL KEEP VCTS AT KBIS AND KMOT THROUGH AROUND
22Z...AND AT KJMS FROM 18Z THROUGH 02Z.
LATE TONIGHT ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS IS EXPECTED
TO MOVE INTO WESTERN NORTH DAKOTA MAINLY AFT 06Z.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...CK
SHORT TERM...JV
LONG TERM...CK
AVIATION...JV
AREA FORECAST DISCUSSION
NWS BISMARCK ND
327 AM CDT WED AUG 5 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 324 AM CDT WED AUG 5 2015
TIMING AND PRECIP CHANCES/AREAL COVERAGE OF SHOWERS AND
THUNDERSTORMS TODAY AND TONIGHT ARE THE MAIN CHALLENGES IN TODAY`S
SHORT TERM PERIOD.
CURRENTLY...AN AREA OF SHOWERS AND THUNDERSTORMS CONTINUED OVER
SOUTHWESTERN NORTH DAKOTA AND NORTHEASTERN MONTANA...THOUGH THE
INTENSITY OF SHOWERS AND THUNDERSTORMS HAS WANED WITH TIME EARLY
THIS MORNING. THE CONVECTION WAS ASSOCIATED WITH AN UPPER LEVEL
SHORTWAVE THAT IS FORECAST TO CONTINUE MOVING EASTWARD SLOWLY
ACROSS THE STATE TODAY.
THE LATEST ITERATIONS OF THE HRRR AND NAM SUGGEST THAT THE AREA OF
CONVECTION WILL STILL BE IN WESTERN NORTH DAKOTA BUT APPROACHING
CENTRAL NORTH DAKOTA BY DAYBREAK TODAY. THE LATEST HRRR SUGGESTS THE
CONVECTION WOULD BEGIN INCREASING IN INTENSITY BEFORE NOON OVER
CENTRAL NORTH DAKOTA...IN A WIDE LINE OF CONVECTION EXTENDING FROM
WESTERN MANITOBA TO MINOT TO BISMARCK BEFORE NOON. THE MODELS
SUGGEST THAT THE TURTLE MOUNTAINS AND JAMES VALLEY AND EASTWARD WILL
BE THE FAVORED AREA FOR CONVECTION DURING THE AFTERNOON.
CAPE AND SHEAR VALUES ARE MODEST THIS AFTERNOON IN CENTRAL NORTH
DAKOTA...THUS A FEW STORMS COULD BE ON THE STRONG SIDE...BUT
INGREDIENTS ARE NOT FAVORABLE FOR A MENTION OF A SEVERE THREAT.
ATTENTION THEN TURNS WESTWARD. WEDNESDAY MORNING AND AFTERNOON A
RATHER POTENT SERIES OF UPPER LEVEL IMPULSES EMERGING FROM A TROUGH
OVER THE WEST COAST MOVES EASTWARD ACROSS MONTANA/WYOMING. THESE
UPPER LEVEL IMPULSES ENTER THE WESTERN DAKOTAS LATE THIS AFTERNOON
OR EARLY EVENING (MODELS DIFFER ON TIMING)...AND EXPAND EASTWARD
ACROSS THE STATE TONIGHT. PRECIPITATION CHANCES FOR THIS EVENING
BEGIN IN THE WEST BY MID-EVENING...SPREADING EAST INTO CENTRAL NORTH
DAKOTA AFTER MIDNIGHT.
THE BEST CAPE AND SHEAR WITH THIS POTENT WAVE APPEARS TO BE
FARTHER SOUTH INTO SOUTH DAKOTA AND NEBRASKA...BUT THE MODEST
VALUES IN NORTH DAKOTA COULD BE ENOUGH FOR A FEW OF THE STORMS TO
BE ON THE STRONG SIDE.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 324 AM CDT WED AUG 5 2015
THE LONG TERM PERIOD BEGINS THURSDAY WITH SHOWERS AND THUNDERSTORMS
ACROSS EASTERN MONTANA / WESTERN NORTH DAKOTA MOVING THEIR WAY
EAST DURING THE DAY. THESE ARE IN RESPONSE TO AN H5 WAVE AND
UPPER LEVEL JET STREAK MOVING ACROSS THE NORTHERN PLAINS. THE
DETERMINISTIC MODELS HAVE COME INTO FAIRLY GOOD AGREEMENT IN THIS
SCENARIO...SO WILL CARRY LIKELY POPS FROM NORTHWEST NORTH
DAKOTA...THROUGH THE CENTRAL PART OF THE STATE AND TOWARDS THE
SOUTHERN JAMES RIVER VALLEY. THE DAY 2 CONVECTIVE OUTLOOK FROM THE
STORM PREDICTION CENTER PLACES MUCH OF CENTRAL AND EASTERN NORTH
DAKOTA IN A MARGINAL RISK...AND THAT APPEARS REASONABLE WITH
SBCAPE VALUES OF 1500-2500...THOUGH SHEAR IS RATHER MARGINAL.
CONSIDERED GOING DRY FOR FRIDAY ACROSS ALL OF WESTERN AND CENTRAL
NORTH DAKOTA...BUT AFTER COLLABORATION WITH SURROUNDING OFFICES
OPTED TO KEEP A SLIGHT CHANCE OF THUNDERSTORMS IN THE FAR SOUTH.
THE 05.00Z GFS AND ECMWF BRING A SMALL CHANCE OF RAIN INTO THE
FAR SOUTH...WHILE THE NAM IS DRY.
RAIN CHANCES SHOULD INCREASE AGAIN SATURDAY NIGHT INTO SUNDAY AS
THE NEXT H5 WAVE MOVES ACROSS THE REGION. THE HIGHER RAIN CHANCES
ARE EXPECTED TO BE IN SOUTHERN PARTS OF THE FORECAST AREA...CLOSER
TO THE MORE ROBUST FORCING. AN UPPER RIDGE BUILDS INTO THE
NORTHERN PLAINS EARLY NEXT WEEK...WHICH WILL BRING DRIER WEATHER
TO WESTERN AND CENTRAL NORTH DAKOTA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 324 AM CDT WED AUG 5 2015
VFR CONDITIONS ARE EXPECTED THROUGH THE FORECAST PERIOD OUTSIDE OF
THUNDERSTORMS. SHOWERS AND THUNDERSTORMS OVER SOUTHWESTERN NORTH
DAKOTA AND NORTHEASTERN MONTANA ARE EXPECTED TO APPROACH KISN AND
KDIK AROUND 06Z-07Z LASTING FOR A FEW HOURS THROUGH 09Z-10Z. AREA OF
CONVECTION REACHING KMOT/KBIS AROUND 12Z-14Z...AND KJMS AFTER 18Z.
LATE WEDNESDAY NIGHT ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS
EXPECTED TO MOVE INTO WESTERN NORTH DAKOTA MAINLY AFT 06Z THU.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...JV
LONG TERM...CK
AVIATION...JV
AREA FORECAST DISCUSSION
NWS MEDFORD OR
1049 PM PDT TUE AUG 4 2015
.UPDATE...JUST MADE A VERY QUICK UPDATE TO ADJUST POPS AND
THUNDERSTORM COVERAGE TO CURRENT TRENDS. HAD TO PULL ISOLATED
THUNDER BACK ONTO THE WEST SIDE TO ACCOUNT FOR SOME CONVECTION
THAT JUST POPPED UP OVER MT. ASHLAND. THIS SEEMS TO BE ASSOCIATED
WITH SOME DEFORMATION STRETCHED FROM WEST TO EAST ACROSS THE AREA.
DON`T THINK WE`LL SEE MUCH MORE THAN THIS, BUT OBVIOUSLY WE`LL
HAVE TO KEEP ANY EYE ON IT TONIGHT AS THINGS ARE SOMEWHAT
VOLATILE. THUNDERSTORM COVERAGE IS DEFINITELY INCREASING EAST OF
THE CASCADES, PRETTY MUCH EXACTLY WHERE THE MODELS HAD IT, SO THE
REMAINING RED FLAG WARNINGS LOOK ON TRACK. -WRIGHT
&&
.AVIATION...FOR THE 05/06Z TAF CYCLE...SHOWERS AND THUNDERSTORMS
ARE DIMINISHING ACROSS WESTERN SISKIYOU COUNTY, BUT THEY ARE
DEVELOPING EAST OF THE CASCADES, WHICH WAS EXPECTED. GUSTY,
ERRATIC WINDS, LIGHTNING, AND BRIEF DOWNPOURS WILL BE POSSIBLE
WITH THESE STORMS, INCLUDING AT KLMT FOR THE NEXT FEW HOURS AT
LEAST. STRATUS HAS YET TO MOVE INTO NORTH BEND, BUT ALL
INDICATIONS ARE THAT IT WILL EVENTUALLY. SMOKE HAS DISSIPATED IN
THE ROGUE VALLEY, INCLUDING KMFR, BUT STREAMLINE ANALYSIS SUGGEST
IT MAY COME BACK OVERNIGHT AS LIGHT WINDS BECOME MORE NORTHERLY.
IT SHOULD ALSO INCREASE AGAIN TOMORROW AS DIURNAL WINDS DRIVE IT
IN. THIS DEPENDS ON WHAT HAPPENS WITH THE FIRE, OF COURSE, BUT
FORECAST WINDS SUPPORT A RETURN OF SMOKE. -WRIGHT
&&
.PREV DISCUSSION... /ISSUED 915 PM PDT TUE AUG 4 2015/
DISCUSSION...THE IMMEDIATE FOCUS IS ON THE CONVECTIVE FORECAST.
AN EVENING UPDATE TO THE FORECAST IS NOT NECESSARY. DURING THE
PAST COUPLE OF HOURS, A VERY STRONG COMPLEX OF THUNDERSTORMS
DEVELOPED OVER WESTERN SISKIYOU COUNTY NORTH OF THE SCOTT VALLEY
EXTENDING TO ROUTE 3 BETWEEN FT JONES AND YREKA. THIS COMPLEX HAS
WEAKENED DURING THE PAST HALF HOUR...LIKELY WITH SOME AID FROM THE
END OF DAY-TIME HEATING. BUT, ADDITIONAL ISOLATED TO SCATTERED
THUNDERSTORMS ARE EXPECTED OVERNIGHT UNTIL AROUND 5 AM IN SISKIYOU
COUNTY AND ACROSS MOST OF THE EAST SIDE AS AN UPPER LEVEL TROUGH
NORTH OF THE SAN FRANCISCO BAY CONTINUES MOVING NORTHEASTWARD. THE
INFLUENCE OF THIS TROUGH (WITH THE LIKELY FOCUS FOR OVERNIGHT
THUNDERSTORM DEVELOPMENT) IS SEEN BY THE WEAK RADAR RETURNS IN THE
CURRENT SCAN OVER FAR EASTERN SISKIYOU, MODOC, AND THE SOUTHERN
PORTIONS OF KLAMATH AND LAKE COUNTIES.
THE AIR MASS OVER OUR AREA WILL STABILIZE ON WEDNESDAY AS THE
TROUGH EXITS TO THE EAST AND A MORE MARITIME INFLUENCED AIR MASS
WITH WESTERLY MID-LEVEL FLOW BRINGS COOLER TEMPERATURES FOR ONE
DAY. ANOTHER TROUGH WILL MOVE TO THE CENTRAL CALIFORNIA COAST ON
THURSDAY AND SEND INLAND HIGH TEMPERATURES BACK UP TO THE
NEIGHBORHOOD OF THE READINGS EXPERIENCED THIS AFTERNOON. THIS
TROUGH IS NOT EXPECTED TO FOLLOW EXACTLY THE SAME TRACK AS
TONIGHT`S TROUGH BUT THE 18Z GFS AND 00Z NAM MODELS AGREE ON
INCREASED INSTABILITY AND LITTLE DAY-TO-DAY CHANGE IN HIGHS ON
FRIDAY WITH ISOLATED TO SCATTERED THUNDERSTORMS DURING THE AFTERNOON
AND EVENING FROM THE MT SHASTA REGION ACROSS THE EAST SIDE.
MARINE...UPDATED 230 PM PDT TUESDAY 4 AUGUST 2015...HIGH PRESSURE
WILL BUILD OFFSHORE AND A THERMAL TROUGH WILL DEVELOP ALONG THE
COAST THEN STRENGTHEN INTO THURSDAY. NORTH WINDS AND SEAS WILL
BUILD TONIGHT/WEDNESDAY AND REMAIN MODERATE THROUGH THURSDAY
MORNING. THEN WINDS WILL STRENGTHEN FURTHER THURSDAY AFTERNOON AND
EVENING...POSSIBLY REACHING GALE FORCE OVER THE SOUTHERN OUTER
WATERS. A GALE/HAZARDOUS SEAS WATCH HAS BEEN ISSUED FOR THIS TIME
FRAME FOR AN AREA BEYOND 10 NM AND MAINLY SOUTH OF GOLD BEACH. THE
THERMAL TROUGH WILL WEAKEN FRIDAY INTO SATURDAY. NORTH WINDS AND
SEAS WILL EASE AT THAT TIME. SPILDE
PREV DISCUSSION... /ISSUED 500 PM PDT TUE AUG 4 2015/
SHORT TERM...TODAY AND TONIGHT, A SHORTWAVE MOVING UP FROM THE
SOUTHWEST WILL ALLOW ISOLATED TO SCATTERED THUNDERSTORMS TO
DEVELOP OVER EASTERN AND SOUTHERN PORTIONS OF THE AREA. THIS WILL
MAINLY AFFECT NORTHERN CALIFORNIA AND AREAS EAST OF THE CASCADES.
MODELS CONTINUE TO INDICATE THE BEST CHANCE FOR THUNDERSTORMS IS
OVER WESTERN SISKIYOU COUNTY AND EAST OF THE CASCADES, ESPECIALLY
NEAR SUMMER RIM.
THIS DISTURBANCE WILL SHIFT EAST ON WEDNESDAY AND EXPECT MAINLY
DRY AND WARM CONDITIONS OVER THE AREA. A SURFACE THERMAL TROUGH
WILL DEVELOP ALONG THE COAST WEDNESDAY NIGHT INTO THURSDAY. THIS
WILL BRING BREEZY OFFSHORE FLOW TO THE COASTAL RIDGES WITH A
CHETCO EFFECT BRINGING WARM TEMPERATURES TO THE BROOKINGS AREA.
LATE THURSDAY, EXPECT AN UPPER LOW TO SHIFT INTO THE COAST OF
CENTRAL CALFIORNIA THEN MOVE INLAND THURSDAY NIGHT. AS THIS
FEATURE MOVES INLAND EXPECT SOUTHERLY MOISTURE TO MOVE INTO
SOUTHEAST PORTIONS OF THE AREA WITH A SLIGHT CHANCE OF
THUNDERSTORMS BY FRIDAY MORNING OVER NORTHERN CALIFORNIA ZONES. AS
THE UPPER LEVEL TROUGH SHIRTS NORTHEASTWARD INTO NORTHEAST
CALIFORNIA AND NORTHWEST NEVADA, THE CHANCE FOR THUNDERSTORMS WILL
INCREASE FRIDAY AFTERNOON AND EVENING, MAINLY OVER NORTHERN
CALIFORNIA AND FROM THE CASCADES EAST IN SOUTHERN OREGON.
AREAS OF SMOKE WILL CONTINUE TO AFFECT AREAS FROM THE CASCADES
WEST AT LEAST THROUGH THUS WEEKEND AS DAYTIME NORTH TO NORTHWEST
FLOW PREVAILS. OFFSHORE FLOW ON THURSDAY MAY BRING LESS SMOKE TO
THE CASCADES BUT INCREASED SMOKE TO THE CURRY COAST.
LONG TERM...SATURDAY THROUGH EARLY NEXT WEEK...MODELS ARE SHOWING
AN UPPER LOW WILL GRADUALLY MOVES DOWN THE COAST OF BRITISH
COLUMBIA AND BECOMES CENTERED OFF THE COAST OF WASHINGTON SUNDAY
NIGHT INTO MONDAY. AHEAD OF THIS FEATURE, LINGERING MOISTURE AND
INSTABILITY WILL BRING A SLIGHT CHANCE OF THUNDERSTORMS FROM THE
CASCADES EAST AND OVER NORTHERN CALIFORNIA ON SATURDAY. THEN ON
SUNDAY WITH THE LOW SHIFTING FURTHER SOUTH AND A RIDGE
STRENGTHENING INLAND, EXPECT A SLIGHT CHANCE OF THUNDERSTORMS OVER
CENTRAL AND EASTERN PORTIONS OF THE AREA, WITH BEST CHANCES FROM
THE WESTERN CASCADE FOOTHILLS IN OREGON EAST INTO THE CASCADES AND
NORTHERN KLAMATH COUNTY. SOUTH TO SOUTHWEST 700 MB WINDS INCREASE
ON SUNDAY AND MAY SEE SOME GUSTY WINDS DEVELOP OVER THE HIGHER
TERRAIN ESPECIALLY IN THE CASCADES. MODELS ARE SHOWING BETTER
AGREEMENT WITH THE UPPER TROUGH SHIFTING INLAND ON MONDAY INTO
TUESDAY WITH A SLIGHT CHANCE OF SHOWERS OR THUNDERSTORMS POSSIBLE
IN CENTRAL AND EASTERN PORTIONS OF THE AREA.
THE SOUTHERN PORTION OF THE TROUGH MAY CUTOFF AND BRING A CUTOFF
LOW TO NORTHERN CALIFORNIA AROUND WEDNESDAY. HOWEVER, CONFIDENCE
IS LOW IN THE DETAILS FOR WEDNESDAY GIVEN THE VARIABILITY IN MODEL
ENSEMBLE FORECASTS ON WHETHER A CUTOFF LOW WILL DEVELOP AND WHERE
IT MAY BE POSITIONED. /CC
FIRE WEATHER...UPDATED 200 PM PDT TUESDAY 4 AUGUST 2015... MODELS
HAVE TRENDED TOWARDS A MORE CONVECTIVELY ACTIVE AFTERNOON AND
EVENING TODAY. WHILE THE BULK OF MODEL SOLUTIONS SHOW A SWATH OF
INSTABILITY ACROSS NORTHERN CALIFORNIA AND FROM THE CASCADES EAST IN
OREGON, THERE IS QUITE A DIFFERENCE IN THE PRECIPITATION OUTLOOK.
HOWEVER, THE HIGHER RESOLUTION NAM AND HRRR PRECIPITATION FIELDS ARE
DEPICTING AN AREA OF SCATTERED THUNDERSTORMS DEVELOPING OVER WESTERN
SISKIYOU COUNTY LATE THIS AFTERNOON, AND ANOTHER AREA OVER LAKE AND
KLAMATH COUNTIES LATE THIS AFTERNOON AND EVENING. THIS APPEARS TO BE
THE RESULT OF A CONVERGENCE OF SEVERAL FACTORS, INCLUDING A WEAK
SURFACE BOUNDARY, THE PASSAGE OF THE UPPER LEVEL TROUGH AND
ASSOCIATED VORTICITY, AND SOME JET SUPPORT ALOFT. THESE FACTORS,
WHILE EXISTING ONLY A SHORT TIME OVER SISKIYOU COUNTY, MAY LAST WELL
INTO THE NIGHT FARTHER EAST, AND THEREFORE NOCTURNAL STORMS ARE NOT
OUT OF THE QUESTION EAST OF THE CASCADES.
DESPITE HIGH LEVELS OF UNCERTAINTY, HAVE OPTED TO ERR ON THE SIDE OF
CAUTION, ESPECIALLY GIVEN THE CURRENT STATUS OF FIREFIGHTING
RESOURCES, AND ISSUED A RED FLAG WARNING FOR THE ABOVE AREAS. SOME
STORMS MAY BEGIN DRY, BUT SHOULD TREND WETTER AS THE EVENING
PROGRESSES. UNTIL THEN, GUSTY WINDS ARE OF PRIMARY CONCERN. OVERALL,
LIGHTING HAS THE POTENTIAL TO PRODUCE NUMEROUS STARTS, ESPECIALLY
GIVEN THE IGNITION RATE OVER THE PAST SEVERAL DAYS.
THUNDERSTORMS SHOULD COME TO AN END BY WEDNESDAY MORNING, AND NO
OTHER CONVECTION IS EXPECTED UNTIL THE WEEKEND. UNTIL THEN,
TEMPERATURES AND HUMIDITIES SHOULD REMAIN STEADY, ALTHOUGH THERE MAY
BE PERIODS OF MODERATE OVERNIGHT RECOVERIES ACROSS RIDGELINES AT
VARYING TIMES THROUGH THE WEEK AND THIS WEEKEND. GUSTY WINDS MAY
ALSO BE AN ISSUE THIS WEEKEND WITH THE PASSAGE OF A POTENTIALLY
STRONG UPPER LEVEL TROUGH. -BPN
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...RED FLAG WARNING UNTIL 5 AM PDT WEDNESDAY FOR ORZ624-625.
CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS UNTIL 11 PM PDT THIS EVENING FOR
PZZ350-370.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 PM PDT THIS
EVENING FOR PZZ350-370.
SMALL CRAFT ADVISORY FOR WINDS UNTIL 11 PM PDT WEDNESDAY FOR
PZZ356.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 PM PDT
WEDNESDAY FOR PZZ356.
GALE WATCH FROM THURSDAY MORNING THROUGH LATE THURSDAY NIGHT FOR
PZZ376.
SMALL CRAFT ADVISORY FOR WINDS UNTIL 11 AM PDT THURSDAY FOR
PZZ376.
HAZARDOUS SEAS WATCH FROM THURSDAY MORNING THROUGH LATE THURSDAY
NIGHT FOR PZZ376.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 AM PDT THURSDAY
FOR PZZ376.
$$
AREA FORECAST DISCUSSION
NWS MEDFORD OR
915 PM PDT TUE AUG 4 2015
.DISCUSSION...THE IMMEDIATE FOCUS IS ON THE CONVECTIVE FORECAST.
AN EVENING UPDATE TO THE FORECAST IS NOT NECESSARY. DURING THE
PAST COUPLE OF HOURS, A VERY STRONG COMPLEX OF THUNDERSTORMS
DEVELOPED OVER WESTERN SISKIYOU COUNTY NORTH OF THE SCOTT VALLEY
EXTENDING TO ROUTE 3 BETWEEN FT JONES AND YREKA. THIS COMPLEX HAS
WEAKENED DURING THE PAST HALF HOUR...LIKELY WITH SOME AID FROM THE
END OF DAY-TIME HEATING. BUT, ADDITIONAL ISOLATED TO SCATTERED
THUNDERSTORMS ARE EXPECTED OVERNIGHT UNTIL AROUND 5 AM IN SISKIYOU
COUNTY AND ACROSS MOST OF THE EAST SIDE AS AN UPPER LEVEL TROUGH
NORTH OF THE SAN FRANCISCO BAY CONTINUES MOVING NORTHEASTWARD. THE
INFLUENCE OF THIS TROUGH (WITH THE LIKELY FOCUS FOR OVERNIGHT
THUNDERSTORM DEVELOPMENT) IS SEEN BY THE WEAK RADAR RETURNS IN THE
CURRENT SCAN OVER FAR EASTERN SISKIYOU, MODOC, AND THE SOUTHERN
PORTIONS OF KLAMATH AND LAKE COUNTIES.
THE AIR MASS OVER OUR AREA WILL STABILIZE ON WEDNESDAY AS THE
TROUGH EXITS TO THE EAST AND A MORE MARITIME INFLUENCED AIR MASS
WITH WESTERLY MID-LEVEL FLOW BRINGS COOLER TEMPERATURES FOR ONE
DAY. ANOTHER TROUGH WILL MOVE TO THE CENTRAL CALIFORNIA COAST ON
THURSDAY AND SEND INLAND HIGH TEMPERATURES BACK UP TO THE
NEIGHBORHOOD OF THE READINGS EXPERIENCED THIS AFTERNOON. THIS
TROUGH IS NOT EXPECTED TO FOLLOW EXACTLY THE SAME TRACK AS
TONIGHT`S TROUGH BUT THE 18Z GFS AND 00Z NAM MODELS AGREE ON
INCREASED INSTABILITY AND LITTLE DAY-TO-DAY CHANGE IN HIGHS ON
FRIDAY WITH ISOLATED TO SCATTERED THUNDERSTORMS DURING THE AFTERNOON
AND EVENING FROM THE MT SHASTA REGION ACROSS THE EAST SIDE.
&&
.AVIATION...FOR THE 05/00Z TAF CYCLE...ALONG THE COAST...IFR
CIGS ARE IMPACTING THE COAST FROM GOLD BEACH SOUTH TO BROOKINGS. VFR
WILL PREDOMINATE EARLY THIS EVENING ELSEWHERE ALONG THE COAST, BUT
EXPECT A MIX OF IFR/MVFR CIGS TO RETURN AFTER 03Z, INCLUDING AT
KOTH. VFR WILL PREVAIL AT KRBG, BUT WILDFIRE SMOKE WILL BRING MVFR
VISIBILITY TO KMFR TONIGHT INTO WEDNESDAY. VIS MAY LOWER TEMPORARILY
TO IFR THIS EVENING. IN NORTHERN CALIFOTRNIA AND EAST OF THE
CASCADES...ISOLATED THUNDERSTORMS ARE EXPECTED THIS EVENING. AN AREA
OF SHOWERS AND THUNDERSTORMS MAY ALSO MOVE INTO SOUTHEAST
SECTIONS OF THE AREA OVERNIGHT INTO WEDNESDAY MORNING. THESE MAY
BRIEFLY LOWER CIGS TO MVFR, BUT CONDITIONS SHOULD LARGELY REMAIN
VFR. SPILDE
&&
.MARINE...UPDATED 230 PM PDT TUESDAY 4 AUGUST 2015...HIGH PRESSURE WILL
BUILD OFFSHORE AND A THERMAL TROUGH WILL DEVELOP ALONG THE COAST
THEN STRENGTHEN INTO THURSDAY. NORTH WINDS AND SEAS WILL BUILD
TONIGHT/WEDNESDAY AND REMAIN MODERATE THROUGH THURSDAY MORNING.
THEN WINDS WILL STRENGTHEN FURTHER THURSDAY AFTERNOON AND
EVENING...POSSIBLY REACHING GALE FORCE OVER THE SOUTHERN OUTER
WATERS. A GALE/HAZARDOUS SEAS WATCH HAS BEEN ISSUED FOR THIS TIME
FRAME FOR AN AREA BEYOND 10 NM AND MAINLY SOUTH OF GOLD BEACH. THE
THERMAL TROUGH WILL WEAKEN FRIDAY INTO SATURDAY. NORTH WINDS AND
SEAS WILL EASE AT THAT TIME. SPILDE
&&
.PREV DISCUSSION... /ISSUED 500 PM PDT TUE AUG 4 2015/
SHORT TERM...TODAY AND TONIGHT, A SHORTWAVE MOVING UP FROM THE
SOUTHWEST WILL ALLOW ISOLATED TO SCATTERED THUNDERSTORMS TO
DEVELOP OVER EASTERN AND SOUTHERN PORTIONS OF THE AREA. THIS WILL
MAINLY AFFECT NORTHERN CALIFORNIA AND AREAS EAST OF THE CASCADES.
MODELS CONTINUE TO INDICATE THE BEST CHANCE FOR THUNDERSTORMS IS
OVER WESTERN SISKIYOU COUNTY AND EAST OF THE CASCADES, ESPECIALLY
NEAR SUMMER RIM.
THIS DISTURBANCE WILL SHIFT EAST ON WEDNESDAY AND EXPECT MAINLY
DRY AND WARM CONDITIONS OVER THE AREA. A SURFACE THERMAL TROUGH
WILL DEVELOP ALONG THE COAST WEDNESDAY NIGHT INTO THURSDAY. THIS
WILL BRING BREEZY OFFSHORE FLOW TO THE COASTAL RIDGES WITH A
CHETCO EFFECT BRINGING WARM TEMPERATURES TO THE BROOKINGS AREA.
LATE THURSDAY, EXPECT AN UPPER LOW TO SHIFT INTO THE COAST OF
CENTRAL CALFIORNIA THEN MOVE INLAND THURSDAY NIGHT. AS THIS
FEATURE MOVES INLAND EXPECT SOUTHERLY MOISTURE TO MOVE INTO
SOUTHEAST PORTIONS OF THE AREA WITH A SLIGHT CHANCE OF
THUNDERSTORMS BY FRIDAY MORNING OVER NORTHERN CALIFORNIA ZONES. AS
THE UPPER LEVEL TROUGH SHIRTS NORTHEASTWARD INTO NORTHEAST
CALIFORNIA AND NORTHWEST NEVADA, THE CHANCE FOR THUNDERSTORMS WILL
INCREASE FRIDAY AFTERNOON AND EVENING, MAINLY OVER NORTHERN
CALIFORNIA AND FROM THE CASCADES EAST IN SOUTHERN OREGON.
AREAS OF SMOKE WILL CONTINUE TO AFFECT AREAS FROM THE CASCADES
WEST AT LEAST THROUGH THUS WEEKEND AS DAYTIME NORTH TO NORTHWEST
FLOW PREVAILS. OFFSHORE FLOW ON THURSDAY MAY BRING LESS SMOKE TO
THE CASCADES BUT INCREASED SMOKE TO THE CURRY COAST.
LONG TERM...SATURDAY THROUGH EARLY NEXT WEEK...MODELS ARE SHOWING
AN UPPER LOW WILL GRADUALLY MOVES DOWN THE COAST OF BRITISH
COLUMBIA AND BECOMES CENTERED OFF THE COAST OF WASHINGTON SUNDAY
NIGHT INTO MONDAY. AHEAD OF THIS FEATURE, LINGERING MOISTURE AND
INSTABILITY WILL BRING A SLIGHT CHANCE OF THUNDERSTORMS FROM THE
CASCADES EAST AND OVER NORTHERN CALIFORNIA ON SATURDAY. THEN ON
SUNDAY WITH THE LOW SHIFTING FURTHER SOUTH AND A RIDGE
STRENGTHENING INLAND, EXPECT A SLIGHT CHANCE OF THUNDERSTORMS OVER
CENTRAL AND EASTERN PORTIONS OF THE AREA, WITH BEST CHANCES FROM
THE WESTERN CASCADE FOOTHILLS IN OREGON EAST INTO THE CASCADES AND
NORTHERN KLAMATH COUNTY. SOUTH TO SOUTHWEST 700 MB WINDS INCREASE
ON SUNDAY AND MAY SEE SOME GUSTY WINDS DEVELOP OVER THE HIGHER
TERRAIN ESPECIALLY IN THE CASCADES. MODELS ARE SHOWING BETTER
AGREEMENT WITH THE UPPER TROUGH SHIFTING INLAND ON MONDAY INTO
TUESDAY WITH A SLIGHT CHANCE OF SHOWERS OR THUNDERSTORMS POSSIBLE
IN CENTRAL AND EASTERN PORTIONS OF THE AREA.
THE SOUTHERN PORTION OF THE TROUGH MAY CUTOFF AND BRING A CUTOFF
LOW TO NORTHERN CALIFORNIA AROUND WEDNESDAY. HOWEVER, CONFIDENCE
IS LOW IN THE DETAILS FOR WEDNESDAY GIVEN THE VARIABILITY IN MODEL
ENSEMBLE FORECASTS ON WHETHER A CUTOFF LOW WILL DEVELOP AND WHERE
IT MAY BE POSITIONED. /CC
FIRE WEATHER...UPDATED 200 PM PDT TUESDAY 4 AUGUST 2015... MODELS
HAVE TRENDED TOWARDS A MORE CONVECTIVELY ACTIVE AFTERNOON AND
EVENING TODAY. WHILE THE BULK OF MODEL SOLUTIONS SHOW A SWATH OF
INSTABILITY ACROSS NORTHERN CALIFORNIA AND FROM THE CASCADES EAST IN
OREGON, THERE IS QUITE A DIFFERENCE IN THE PRECIPITATION OUTLOOK.
HOWEVER, THE HIGHER RESOLUTION NAM AND HRRR PRECIPITATION FIELDS ARE
DEPICTING AN AREA OF SCATTERED THUNDERSTORMS DEVELOPING OVER WESTERN
SISKIYOU COUNTY LATE THIS AFTERNOON, AND ANOTHER AREA OVER LAKE AND
KLAMATH COUNTIES LATE THIS AFTERNOON AND EVENING. THIS APPEARS TO BE
THE RESULT OF A CONVERGENCE OF SEVERAL FACTORS, INCLUDING A WEAK
SURFACE BOUNDARY, THE PASSAGE OF THE UPPER LEVEL TROUGH AND
ASSOCIATED VORTICITY, AND SOME JET SUPPORT ALOFT. THESE FACTORS,
WHILE EXISTING ONLY A SHORT TIME OVER SISKIYOU COUNTY, MAY LAST WELL
INTO THE NIGHT FARTHER EAST, AND THEREFORE NOCTURNAL STORMS ARE NOT
OUT OF THE QUESTION EAST OF THE CASCADES.
DESPITE HIGH LEVELS OF UNCERTAINTY, HAVE OPTED TO ERR ON THE SIDE OF
CAUTION, ESPECIALLY GIVEN THE CURRENT STATUS OF FIREFIGHTING
RESOURCES, AND ISSUED A RED FLAG WARNING FOR THE ABOVE AREAS. SOME
STORMS MAY BEGIN DRY, BUT SHOULD TREND WETTER AS THE EVENING
PROGRESSES. UNTIL THEN, GUSTY WINDS ARE OF PRIMARY CONCERN. OVERALL,
LIGHTING HAS THE POTENTIAL TO PRODUCE NUMEROUS STARTS, ESPECIALLY
GIVEN THE IGNITION RATE OVER THE PAST SEVERAL DAYS.
THUNDERSTORMS SHOULD COME TO AN END BY WEDNESDAY MORNING, AND NO
OTHER CONVECTION IS EXPECTED UNTIL THE WEEKEND. UNTIL THEN,
TEMPERATURES AND HUMIDITIES SHOULD REMAIN STEADY, ALTHOUGH THERE MAY
BE PERIODS OF MODERATE OVERNIGHT RECOVERIES ACROSS RIDGELINES AT
VARYING TIMES THROUGH THE WEEK AND THIS WEEKEND. GUSTY WINDS MAY
ALSO BE AN ISSUE THIS WEEKEND WITH THE PASSAGE OF A POTENTIALLY
STRONG UPPER LEVEL TROUGH. -BPN
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...RED FLAG WARNING UNTIL 5 AM PDT WEDNESDAY FOR ORZ624-625.
CA...RED FLAG WARNING UNTIL 11 PM PDT THIS EVENING FOR CAZ280.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS UNTIL 11 PM PDT THIS EVENING FOR
PZZ350-370.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 PM PDT THIS
EVENING FOR PZZ350-370.
SMALL CRAFT ADVISORY FOR WINDS UNTIL 11 PM PDT WEDNESDAY FOR
PZZ356.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 PM PDT
WEDNESDAY FOR PZZ356.
GALE WATCH FROM THURSDAY MORNING THROUGH LATE THURSDAY NIGHT FOR
PZZ376.
SMALL CRAFT ADVISORY FOR WINDS UNTIL 11 AM PDT THURSDAY FOR
PZZ376.
HAZARDOUS SEAS WATCH FROM THURSDAY MORNING THROUGH LATE THURSDAY
NIGHT FOR PZZ376.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 AM PDT THURSDAY
FOR PZZ376.
$$
DW/TRW/MAS
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
244 PM EDT WED AUG 5 2015
.SYNOPSIS...
A WEAK COLD FRONT WILL BECOME NEARLY OVER THE AREA TONIGHT. AS MOISTURE
INCREASES ACROSS OUR REGION EARLY TOMORROW...A LOW WILL DEVELOP AND GRADUALLY
MOVE OFFSHORE BY LATE FRIDAY. WEAK HIGH PRESSURE WILL SPREAD BACK OVER
THE REGION IN THE WAKE OF THE LOW.
&&
.NEAR TERM /THROUGH THURSDAY/...
AT 215 PM...SPC MESO ANAL SHOWS MODERATE INSTABILITRY ACROSS THE
SOUTHERN UPSTATE INTO NE GA WITH UPWARDS OF 2000J OF SBCAPE. HAVE
INCREASED POPS IN THAT AREA INTO SCT RANGE AS RADAR SHOWS A COUPLE
CELLS BEGINNING TO DEVELOP AND HRRR PICKS UP ON THAT TO PRODUCE SCT
CELLS THE NEXT SEVERAL HOURS. FARTHER N IN WESTERN NC...INSTABILITY
LESS BUT WEAK PVA AIDING IN SOME SCT CELLS DEVELOPING THERE.
HENCE...WILL HAVE SCT POPS BLANKETING THE AREA THROUGH THE
AFTERNOON. WITH DCAPES OVER THE PIEDMONT EXCEEDING 1000J...A FEW
SEVERE STORMS CAN NOT BE RULED OUT.
SOME CELLS COULD LINGER THROUGH THE EVENING IN WESTERN NC AS THE
WORK VORT MAX MOVES THROUGH. CAMS DO SUGGEST THAT ACTIVITY WILL WANE
WITH LOSS OF HEATING OVERNIGHT. ONCE CONVECTION WANES...PARTLY
CLOUDY CONDITIONS WILL PREVAIL WITH LOWS A CATEGORY OR SO ABOVE
CLIMO.
ON THURSDAY...A MORE SUBSTANTIAL SHORT WAVE WILL APPROACH FROM THE
WEST. WITH DPVA IMPROVING THROUGHOUT THE DAY...MODELS RESPOND WITH
NUMEROUS SHOWERS/THUNDERSTORMS MOST AREAS THURSDAY AFTERNOON. THE
INCREASE IN CLOUDS AND CONVECTIVE COVERAGE WILL KEEP MAX TEMPS
CLOSER TO CLIMO ON THURSDAY.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
AS OF 240 PM EDT WEDNESDAY...A VIGOROUS 500 MB SHORTWAVE TROUGH WILL
SHARPEN UP JUST WEST OF THE SRN APPALACHIANS LATE THURSDAY AND THEN
CROSS THE FORECAST AREA THU NIGHT. THE BEST LOBE OF DEEP LAYER Q
VECTOR CONVERGENCE ASSOCIATED WITH THE PASSAGE OF THE WAVE WILL
AFFECT THE AREA MAINLY THURSDAY EVENING. DESPITE DEEPENING OF THE
ASSOCIATED 850 MB LOW CENTER ASSOCIATED WITH THIS FEATURE OVER THE
LOWER OH VALLEY LATE THURSDAY...VERY LITTLE INCREASE IN SRLY/SWLY
FLOW MOISTURE IS EXPECTED AHEAD OF THE RAPIDLY MOVING WAVE. THE
RAPID FORWARD SPEED OF THE SYSTEM SHOULD LARGELY PRECLUDE ANY
SIGNIFICANT HYDRO ISSUES THU NIGHT. ANY BRIEF UPTICK IN LOW LEVEL
FLOW COULD COMBINE WITH LINGERING LATE DAY INSTABILITY TO PRODUCE A
FEW STRONG THUNDERSTORMS.
DEEP MID AND UPPER DRYING WILL ARRIVE ON NW FLOW FRIDAY THROUGH
FRIDAY NIGHT...BUT WITH LINGERING BOUNDARY LAYER MOISTURE POSSIBLY
YIELDING A MORNING STRATUS LAYER EACH DAY. UPPER HEIGHTS WILL SLOWLY
BUILD THROUGH SATURDAY...WITH A RETURN TO MAINLY DIURNAL RIDGE TOP
ISOLATED TO SCT CONVECTION. TEMPS WILL RETURN TO NEAR CLIMO THROUGH
THE PERIOD.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 210 PM EDT WEDNESDAY...THE MEDIUM RANGE FCST PICKS UP AT 00Z ON
SUNDAY WITH UPPER TROFFING LIFTING OFF THE ATLANTIC COAST TO OUR NE
AND THE BROAD UPPER RIDGE SLOWLY SPREADING EASTWARD AND INTO THE FCST
AREA. THE LONG RANGE GUIDANCE INDICATES THAT THE RIDGE WONT ADVANCE
VERY FAR EAST BEFORE ANOTHER UPPER TROF DIGS DOWN OVER THE EASTERN
CONUS. THE MODELS SUGGEST THAT BY EARLY TUES THE TROF AXIS WILL LIKELY
BE JUST TO OUR NORTH WITH FURTHER DEEPENING LIKELY THRU THE REMAINDER
OF THE PERIOD. AT THE SFC...A COASTAL LOW WILL BE MOVING FARTHER OFF
THE ATLANTIC SEABOARD BY EARLY SUN WITH WEAK HIGH PRESSURE SPREADING
BACK OVER THE FCST AREA. BY LATE MON/EARLY TUES...THE MODELS TRY TO DEVELOP
SOME SORT OF SFC LOW OVER THE FCST AREA OR JUST NORTH OF IT...YET THE
LOCATION AND TIMING ARE STILL UNCLEAR. THE MODELS DO AGREE THAT BY
EARLY WED...THE LOW SHOULD BE MOVING WELL OFFSHORE WITH STRONGER SFC HIGH
PRESSURE BUILDING BACK OVER THE FCST AREA TO END THE PERIOD. AS FOR THE
SENSIBLE FCST...THINGS START OUT MOSTLY DRY WITH ONLY A SLIGHT CHANCE
FOR SCT CONVECTION. AS THE PROFILES MOISTEN ON MON AND THE LOW LVL SLY
FLOW INCREASES...POPS INCREASE TO HIGH END CHANCE OVER MOST OF THE CWFA
FOR BOTH MON AND TUES WITH DRYING ON WED AS HIGH PRESSURE IS EXPECTED
TO MOVE BACK OVER THE REGION. TEMPS SHOULD REMAIN NEAR CLIMATOLOGY...IF
NOT JUST ABOVE...FOR MOST OF THE PERIOD WITH SOME COOLING TOWARDS DAY 7.
&&
.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
AT KCLT...EXPECT VFR CONDITIONS TO PREVAIL. THE MAIN QUESTION IS
WHETHER ANY CONVECTION WILL AFFECT THE AIRFIELD THIS AFTERNOON INTO
THIS EVENING. WITH SCT CELLS DEVLOPING TO THE WEST...HAVE ELECTED TO
HAVE A TEMPO FOR TSRA BEGINNING AT 22Z WITH SOME RESTRICTIONS. AFTER
THE CONVECTION WANES THIS EVENING...ONLY SCT-BKN MID/HIGH LEVEL
CLOUDINESS EXPECTED.
ELSEWHERE...SIMILAR CONDITIONS TO KCLT...EXCEPT FOR EARLIER CHC OF
CONVECTION. HAVE CARRIED A VCTS ALL TAF SITES UNTIL ABOUT 00Z AND
WILL MONITOR CLOSELY TO SEE IF WE NEED TO GO TEMPO ANYWHERE.
OTHERWISE...VFR WITH FOG RELEGATED TO LITTLE TN VALLEY.
OUTLOOK...GRADUALLY INCREASING PRECIPITATION/RESTRICTION CHANCES ARE
EXPECTED THURSDAY AFTERNOON INTO FRIDAY AS AN UPPER LEVEL DISURBANCE
MOVES ACROSS THE REGION PRODUCING A WAVE OF LOW PRESSURE ON THE
STALLED FRONT LYING ACROSS THE WESTERN CAROLIANS INTO GA. SOME
DRYING IS EXPECTED LATE FRI INTO THE WEEKEND AS THE LOW AND FRONT
MOVE OUT OF THE AREA.
CONFIDENCE TABLE...
18-24Z 00-06Z 06-12Z 12-18Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 100% HIGH 80% HIGH 91%
KHKY HIGH 100% HIGH 100% HIGH 88% HIGH 97%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 88% HIGH 100% HIGH 100% HIGH 97%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JPT
NEAR TERM...LG
SHORT TERM...HG
LONG TERM...JPT
AVIATION...LG
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
232 PM EDT WED AUG 5 2015
.SYNOPSIS...
A WEAK COLD FRONT WILL BECOME NEARLY OVER THE AREA TONIGHT. AS MOISTURE
INCREASES ACROSS OUR REGION EARLY TOMORROW...A LOW WILL DEVELOP AND GRADUALLY
MOVE OFFSHORE BY LATE FRIDAY. WEAK HIGH PRESSURE WILL SPREAD BACK OVER
THE REGION IN THE WAKE OF THE LOW.
&&
.NEAR TERM /THROUGH THURSDAY/...
AT 215 PM...SPC MESO ANAL SHOWS MODERATE INSTABILITRY ACROSS THE
SOUTHERN UPSTATE INTO NE GA WITH UPWARDS OF 2000J OF SBCAPE. HAVE
INCREASED POPS IN THAT AREA INTO SCT RANGE AS RADAR SHOWS A
COUPLE CELLS BEGINNING TO DEVELOP AND HRRR PICKS UP ON THAT TO
PRODCUE SCT CELLS THE NEXT SEVERAL HOURS. FARTHER N IN WESTERN
NC...INSTABILITY LESS BUT WEAK PVA AIDING IN SOME SCT CELLS
DEVELOPING THERE. HENCE...WILL HAVE SCT POPS BLANKETING THE AREA
THROUGH THE AFTERNOON. WITH DCAPES OVER THE PIEDMONT EXCEEDING
1000J...A FEW SEVERE STORMS CAN NOT BE RULED OUT.
SOME CELLS COULD LINGER THROUGH THE EVENING IN WESTERN NC AS THE
WORK VORT MAX MOVES THROUGH. CAMS DO SUGGEST THAT ACTIVITY WILL WANE
WITH LOSS OF HEATING OVERNIGHT. ONCE CONVECTION WANES...PARTLY
CLOUDY CONDITIONS WILL PREVAIL WITH LOWS A CATEGORY OR SO ABOVE
CLIMO.
ON THURSDAY...A MORE SUBSTANTIAL SHORT WAVE WILL APPROACH FROM THE
WEST. WITH DPVA IMPROVING THROUGHOUT THE DAY...MODELS RESPOND WITH
NUMEROUS SHOWERS/THUNDERSTORMS MOST AREAS THURSDAY AFTERNOON. THE
INCREASE IN CLOUDS AND CONVECTIVE COVERAGE WILL KEEP MAX TEMPS
CLOSER TO CLIMO ON THURSDAY.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY/...
AT 230 AM EDT WEDNESDAY...ON THURSDAY MORNING A LOW AMPLITUDE
UPPER RIDGE WILL BE OVER THE WEST AND A LOW AMPLITUDE TROUGH WILL BE
OVER THE EAST. MEANWHILE...A WELL DEFINED SHORTWAVE WILL CROSSING
THE MID MS RIVER VALLEY. THE UPPER PATTERN STARTS TO AMPLIFY ON
THURSDAY NIGHT...WHILE THE SHORTWAVE CROSSES THE SOUTHERN
APPALACHIANS. ON FRIDAY ANOTHER...WEAKER SHORTWAVE APPROACHES THE
MOUNTAINS...WHILE THE UPPER PATTERN CONTINUES TO AMPLIFY. THIS
SECOND SHORTWAVE MOVES INTO OUR AREA LATE FRIDAY NIGHT.
AT THE SURFACE...A SLOW MOVING COLD FRONT WILL BE OVER OUR AREA ON
THURSDAY MORNING. THE FRONT SLIDES SOUTH OF OUR AREA ON THURSDAY
EVENING...BUT MOISTURE LINGERING BEHIND IT SUBSTANTIALLY DECREASE
UNTIL LATE FRIDAY. MOISTURE EVEN INCREASES FRIDAY NIGHT AS THE
SECOND SHORTWAVE ARRIVES. MOISTURE AN INSTABILITY WILL BE
SUPPORTIVE OF CONVECTION...MAINLY DURING DAYTIME HEATING. INITIALLY
LOW LEVEL FLOW WILL BE SOUTHWESTERLY...AND NOT VERY FAVORABLE FOR
UPSLOPE FLOW...BUT AS THE SECOND SHORTWAVE ARRIVES IN THE WAKE OF
THE COLD FRONT...VEERING SURFACE WINDS WILL HAVE A WEAK UPSLOPE
COMPONENT INTO THE BLUE RIDGE. TEMPERATURES WILL RUN NEAR NORMAL.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
AS OF 210 PM EDT WEDNESDAY...THE MEDIUM RANGE FCST PICKS UP AT 00Z ON
SUNDAY WITH UPPER TROFFING LIFTING OFF THE ATLANTIC COAST TO OUR NE
AND THE BROAD UPPER RIDGE SLOWLY SPREADING EASTWARD AND INTO THE FCST
AREA. THE LONG RANGE GUIDANCE INDICATES THAT THE RIDGE WONT ADVANCE
VERY FAR EAST BEFORE ANOTHER UPPER TROF DIGS DOWN OVER THE EASTERN
CONUS. THE MODELS SUGGEST THAT BY EARLY TUES THE TROF AXIS WILL LIKELY
BE JUST TO OUR NORTH WITH FURTHER DEEPENING LIKELY THRU THE REMAINDER
OF THE PERIOD. AT THE SFC...A COASTAL LOW WILL BE MOVING FARTHER OFF
THE ATLANTIC SEABOARD BY EARLY SUN WITH WEAK HIGH PRESSURE SPREADING
BACK OVER THE FCST AREA. BY LATE MON/EARLY TUES...THE MODELS TRY TO DEVELOP
SOME SORT OF SFC LOW OVER THE FCST AREA OR JUST NORTH OF IT...YET THE
LOCATION AND TIMING ARE STILL UNCLEAR. THE MODELS DO AGREE THAT BY
EARLY WED...THE LOW SHOULD BE MOVING WELL OFFSHORE WITH STRONGER SFC HIGH
PRESSURE BUILDING BACK OVER THE FCST AREA TO END THE PERIOD. AS FOR THE
SENSIBLE FCST...THINGS START OUT MOSTLY DRY WITH ONLY A SLIGHT CHANCE
FOR SCT CONVECTION. AS THE PROFILES MOISTEN ON MON AND THE LOW LVL SLY
FLOW INCREASES...POPS INCREASE TO HIGH END CHANCE OVER MOST OF THE CWFA
FOR BOTH MON AND TUES WITH DRYING ON WED AS HIGH PRESSURE IS EXPECTED
TO MOVE BACK OVER THE REGION. TEMPS SHOULD REMAIN NEAR CLIMATOLOGY...IF
NOT JUST ABOVE...FOR MOST OF THE PERIOD WITH SOME COOLING TOWARDS DAY 7.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/... AT KCLT...EXPECT VFR
CONDITIONS TO PREVAIL. THE MAIN QUESTION IS WHETHER ANY CONVECTION
WILL AFFECT THE AIRFIELD THIS AFTERNOON INTO THIS EVENING. WITH
SCT CELLS DEVLOPING TO THE WEST...HAVE ELECTED TO HAVE A TEMPO FOR
TSRA BEGINNING AT 22Z WITH SOME RESTRICTIONS. AFTER THE CONVECTION
WANES THIS EVENING...ONLY SCT-BKN MID/HIGH LEVEL CLOUDINESS
EXPECTED.
ELSEWHERE...SIMILAR CONDITIONS TO KCLT...EXCEPT FOR EARLIER CHC OF
CONVECTION. HAVE CARRIED A VCTS ALL TAF SITES UNTIL ABOUT 00Z AND
WILL MONITOR CLOSELY TO SEE IF WE NEED TO GO TEMPO ANYWHERE.
OTHERWISE...VFR WITH FOG RELEGATED TO LITTLE TN VALLEY.
OUTLOOK...GRADUALLY INCREASING PRECIPITATION/RESTRICTION CHANCES ARE
EXPECTED THURSDAY AFTERNOON INTO FRIDAY AS AN UPPER LEVEL DISURBANCE
MOVES ACROSS THE REGION PRODUCING A WAVE OF LOW PRESSURE ON THE
STALLED FRONT LYING ACROSS THE WESTERN CAROLIANS INTO GA. SOME
DRYING IS EXPECTED LATE FRI INTO THE WEEKEND AS THE LOW AND FRONT
MOVE OUT OF THE AREA.
CONFIDENCE TABLE...
18-24Z 00-06Z 06-12Z 12-18Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 100% HIGH 80% HIGH 91%
KHKY HIGH 100% HIGH 100% HIGH 88% HIGH 97%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 88% HIGH 100% HIGH 100% HIGH 97%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JPT
NEAR TERM...LG
SHORT TERM...HG
LONG TERM...JPT
AVIATION...LG
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
221 PM MDT WED AUG 5 2015
.SHORT TERM...THIS EVENING THROUGH THURSDAY NIGHT
ISSUED AT 218 PM MDT WED AUG 5 2015
UPPER WAVE CONTINUES TO APPROACH THE REGION...AS UPPER
LOW CIRCULATES OVER SOUTHWEST CANADA. WEAK SHOWERS ACROSS NORTHEAST
WYOMING HAVE BEEN DISSIPATING AS THEY MOVE EASTWARD...WITH JUST SOME
CLOUDS PUSHING INTO THE CWA. WITH LIGHT AND VARIABLE WINDS...TEMPS
ARE GENERALLY IN THE 80S.
SHOWERS AND THUNDERSTORMS STILL EXPECTED TO DEVELOP ALONG A LINE OF
FRONTOGENESIS/Q-VECTOR CONVERGENCE ACROSS THE WESTERN CWA AND EXPAND
EASTWARD. MODELS ARE HINTING AT AN INITIAL WAVE WITH BEST FORCING
JUST NORTHWEST OF THE CWA BRINGING A BAND OF STORMS THROUGH THE
NORTHERN HILLS AND NORTHWESTERN SD...WITH A SECONDARY WAVE
IMMEDIATELY FOLLOWING WITH SCATTERED SHOWERS/STORMS. HRRR THIS
MORNING WAS PRETTY CONSISTENT WITH A SQUALL LINE MOVING ACROSS THE
NORTHERN HILLS AND NORTHWEST SD EARLY THIS EVENING...BUT LATER RUNS
ARE SHOWING A MORE SCATTERED FORM. MLCAPE IS UNIMPRESSIVE AROUND
750 J/KG ON THE PLAINS WITH 1500 J/KG OVER THE HILLS...BUT SHEAR
IS 35-45 KTS SO WOULD NOT RULE OUT A STRONG TO SEVERE STORM. MAIN
THREAT WILL BE STRONG WINDS.
SURFACE LOW WILL MOVE ACROSS SD THURSDAY. A TIGHT PRESSURE GRADIENT
BEHIND THE LOW WILL CREATE SOME BREEZY NORTHWEST WINDS ACROSS THE SD
PLAINS AND ALSO BRING IN SOME COOLER AIR TO NORTHWESTERN SD.
SHOWERS/THUNDERSTORMS WILL CONTINUE ACROSS NORTHWESTERN/CENTRAL SD
DURING THE DAY UNTIL THE WAVE FINALLY TRANSITIONS EASTWARD OUT OF
THE REGION. DRY WEATHER IS THEN EXPECTED FOR THURSDAY NIGHT. HIGHS
THURSDAY WILL BE IN THE 80S...70S IN THE BLACK HILLS.
.LONG TERM...FRIDAY THROUGH WEDNESDAY
ISSUED AT 218 PM MDT WED AUG 5 2015
PROGRESSIVE FLOW WILL CONTINUE THROUGH THE WEEKEND WITH
A STRONGER UPPER LEVEL TROUGH ON TRACK FOR SAT-SUN. HOWEVER...STRONG
INDICATIONS ARE IN PLACE FOR SIG LONG WAVE RIDGING OVER CENTRAL NOAM
EARLY NEXT WEEK WHICH WOULD SUPPORT A MUCH WARMER PERIOD FOR THE
REGION BY THE MIDDLE OF NEXT WEEK. HIGHEST POPS IN THE PERIOD ARE IN
THE SAT-SUN PERIOD AS THE CURRENT UPPER LOW OFF THE COAST OF CA
EJECTS NE ACROSS THE ROCKIES AND INTO THE REGION. PLENTY OF LL
MOISTURE WILL BE IN PLACE WITH INCREASING LARGE SCALE ASCENT AND
MONSOON MOISTURE TO SUPPORT SCT SHRA/TS IN THIS PERIOD ESP ACROSS
THE NORTHERN ZONES. LINGERING CHANCES FOR PRECIP SUNDAY NIGHT WITH
DRY WEATHER EXPECTED EARLY NEXT WEEK...PERHAPS A SLIGHT CHANCE OF A
TS OVER THE BLACK HILLS TUES WHEN BETTER MOISTURE RETURNS TO THE
AREA AHEAD OF A LEE TROUGH. SOME SEVERE THREAT WILL BE IN PLACE
SAT/SUN WITH INCREASING FLOW SUPPORTING DECENT BULK SHEAR /0-6KM/
NUMBERS ABOVE 35 KNOTS...WITH 1-2 KJ/KG OF CAPE OVER THE SE FA.
HOWEVER...STILL MUCH UNCERTAINTY PER SYSTEM TRACK/SPEED TO ASCERTAIN
A BETTER GRASP ON SEVERE PROBS.
AFTER A SEASONAL DAY FRIDAY...COOLER TEMPS ARE ON TRACK FOR THE
WEEKEND...WITH A MODEST COOL DOWN EXPECTED SUNDAY.. MUCH WARMER
WEATHER ON TRACK FOR TUE AND BEYOND WITH 90S EXPECTED. A FEW 100/S A
CERTAINLY NOT OUT OF THE QUESTION...ESP ON THE SD PLAINS.
&&
.AVIATION...FOR THE 18Z TAFS THROUGH 18Z THURSDAY
ISSUED AT 218 PM MDT WED AUG 5 2015
ISOLD TSRA ARE POSSIBLE OVER THE BLKHLS AND NERN WY IN THE
AFTN/EVNG...WITH SCT TSRA OVERNIGHT...SPREADING WEST TO EAST. SOME
THUNDERSTORMS MAY PRODUCE GUSTY WINDS. MVFR CIGS/IFR VSBY WITH
THE TSRA.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...POJORLIE
LONG TERM...JC
AVIATION...JC
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1131 AM MDT WED AUG 5 2015
.UPDATE...
ISSUED AT 1004 AM MDT WED AUG 5 2015
UPPER WAVE IS CROSSING UTAH...HELPING TO SPARK SOME SHOWERS AND
THUNDERSTORMS OVER WYOMING...AND EXPECT PRECIP TO MOVE INTO THE
CWA THIS AFTERNOON. AT THE SURFACE...WARM FRONT IS DRAPED NORTH TO
SOUTH ACROSS THE CWA...WITH LIGHT AND VARIABLE WINDS AND TEMPS IN
THE 70S TO LOWER 80S. INCREASED POPS OVER THE NORTHERN HILLS FOR
AFTERNOON CONVECTION THERE...BUT REST OF FORECAST LOOKS ON TRACK.
&&
.SHORT TERM...TODAY THROUGH THURSDAY NIGHT
ISSUED AT 300 AM MDT WED AUG 5 2015
UPPER WAVE NOW CROSSING THE DAKOTAS WILL CONTINUE EWRD WITH
SUBSIDENCE BUILDING ACROSS THE CWA THIS MRNG. RELATIVELY LIGHT SRLY
FLOW WILL CONTINUE TODAY WITH TEMPS REACHING THE 80S TO LOWER 90S.
THE NEXT SHORTWAVE TROUGH IS MOVING ONSHORE THE PAC NW ATTM WITH A
SERIES OF UPPER WAVES ROUNDING THE BASE INTO THE NRN ROCKIES. THESE
WAVES WILL PUSH INTO WY THIS AFTN AND CROSS THE CWA TNGHT. MOST
AREAS WILL REMAIN DRY THIS MRNG...BUT POPS WILL INCREASE IN THE AFTN
INTO TONIGHT AS THE WAVE APPROACHES. HRRR SHOWS STORMS DEVELOPING
ACROSS NE WY/BLKHLS AREAS BY EARLY TO MID AFTN. STORMS ARE THEN
EXPECTED TO CROSS THE CWA TONIGHT AHEAD OF A WEAK FRONT CROSSING THE
AREA. A FEW STORMS COULD BE STRONG TO SEVERE W/ HAIL AND GUSTY
WINDS.
UPPER SYSTEM WILL PUSH EAST OF THE CWA THURSDAY MRNG WITH DRIER AND
SLIGHTLY COOLER AIR FILTERING IN FROM THE W/NW. STORMS MAY BE
LINGERING ACROSS CNTRL SD...BUT OTHERWISE MOST AREAS ARE EXPECTED TO
REMAIN DRY THROUGH THE DAY THUR. HIGHS WILL BE IN THE 80S ON THE
PLAINS...AND 70S ACROSS THE BLKHLS. SKIES WILL CLEAR OUT THROUGH THE
DAY...WITH MOSTLY CLEAR SKIES EXPECTED THU NIGHT. TEMPS WILL DROPS
INTO THE 50S TO LOW 60S.
.LONG TERM...FRIDAY THROUGH TUESDAY
ISSUED AT 300 AM MDT WED AUG 5 2015
ACTIVE PATTERN WILL CONTINUE AS LARGE SCALE RIDGING REMAINS
SUBDUED FOR MOST OF THE PERIOD. THIS WILL SUPPORT PERIODIC CHANCES
FOR SHOWERS AND THUNDERSTORMS AS A SERIES OF TROUGHS PUSH THROUGH
THE REGION. STRONGEST SYSTEM EXPECTED THIS WEEKEND... SUPPORTING
THE HIGHEST POPS SAT/SUN. SEASONAL TEMPS CAN BE EXPECTED THROUGH
THE WEEKEND. RIDGE BUILDS INTO THE NORTHERN PLAINS EARLY NEXT
WEEK...WITH WARMER/DRIER CONDITIONS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY)
ISSUED AT 1124 AM MDT WED AUG 5 2015
ISOLD TSRA ARE POSSIBLE OVER THE BLKHLS AND NERN WY IN THE
AFTN/EVNG...WITH SCT TSRA OVERNIGHT...SPREADING WEST TO EAST. SOME
THUNDERSTORMS MAY PRODUCE GUSTY WINDS. MVFR CIGS/IFR VSBY WITH
THE TSRA.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
UPDATE...POJORLIE
SHORT TERM...13
LONG TERM...7
AVIATION...JC
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1016 AM MDT WED AUG 5 2015
.UPDATE...
ISSUED AT 1004 AM MDT WED AUG 5 2015
UPPER WAVE IS CROSSING UTAH...HELPING TO SPARK SOME SHOWERS AND
THUNDERSTORMS OVER WYOMING...AND EXPECT PRECIP TO MOVE INTO THE
CWA THIS AFTERNOON. AT THE SURFACE...WARM FRONT IS DRAPED NORTH TO
SOUTH ACROSS THE CWA...WITH LIGHT AND VARIABLE WINDS AND TEMPS IN
THE 70S TO LOWER 80S. INCREASED POPS OVER THE NORTHERN HILLS FOR
AFTERNOON CONVECTION THERE...BUT REST OF FORECAST LOOKS ON TRACK.
&&
.SHORT TERM...TODAY THROUGH THURSDAY NIGHT
ISSUED AT 300 AM MDT WED AUG 5 2015
UPPER WAVE NOW CROSSING THE DAKOTAS WILL CONTINUE EWRD WITH
SUBSIDENCE BUILDING ACROSS THE CWA THIS MRNG. RELATIVELY LIGHT SRLY
FLOW WILL CONTINUE TODAY WITH TEMPS REACHING THE 80S TO LOWER 90S.
THE NEXT SHORTWAVE TROUGH IS MOVING ONSHORE THE PAC NW ATTM WITH A
SERIES OF UPPER WAVES ROUNDING THE BASE INTO THE NRN ROCKIES. THESE
WAVES WILL PUSH INTO WY THIS AFTN AND CROSS THE CWA TNGHT. MOST
AREAS WILL REMAIN DRY THIS MRNG...BUT POPS WILL INCREASE IN THE AFTN
INTO TONIGHT AS THE WAVE APPROACHES. HRRR SHOWS STORMS DEVELOPING
ACROSS NE WY/BLKHLS AREAS BY EARLY TO MID AFTN. STORMS ARE THEN
EXPECTED TO CROSS THE CWA TONIGHT AHEAD OF A WEAK FRONT CROSSING THE
AREA. A FEW STORMS COULD BE STRONG TO SEVERE W/ HAIL AND GUSTY
WINDS.
UPPER SYSTEM WILL PUSH EAST OF THE CWA THURSDAY MRNG WITH DRIER AND
SLIGHTLY COOLER AIR FILTERING IN FROM THE W/NW. STORMS MAY BE
LINGERING ACROSS CNTRL SD...BUT OTHERWISE MOST AREAS ARE EXPECTED TO
REMAIN DRY THROUGH THE DAY THUR. HIGHS WILL BE IN THE 80S ON THE
PLAINS...AND 70S ACROSS THE BLKHLS. SKIES WILL CLEAR OUT THROUGH THE
DAY...WITH MOSTLY CLEAR SKIES EXPECTED THU NIGHT. TEMPS WILL DROPS
INTO THE 50S TO LOW 60S.
.LONG TERM...FRIDAY THROUGH TUESDAY
ISSUED AT 300 AM MDT WED AUG 5 2015
ACTIVE PATTERN WILL CONTINUE AS LARGE SCALE RIDGING REMAINS
SUBDUED FOR MOST OF THE PERIOD. THIS WILL SUPPORT PERIODIC CHANCES
FOR SHOWERS AND THUNDERSTORMS AS A SERIES OF TROUGHS PUSH THROUGH
THE REGION. STRONGEST SYSTEM EXPECTED THIS WEEKEND... SUPPORTING
THE HIGHEST POPS SAT/SUN. SEASONAL TEMPS CAN BE EXPECTED THROUGH
THE WEEKEND. RIDGE BUILDS INTO THE NORTHERN PLAINS EARLY NEXT
WEEK...WITH WARMER/DRIER CONDITIONS.
&&
.AVIATION...FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING
ISSUED AT 300 AM MDT WED AUG 5 2015
SOME IFR CIGS/VSBYS MAY CREEP INTO SCNTRL SD EARLY THIS
MORNING FOG/STRATUS DEVELOP ACROSS NEB AND MOVES NWD.
OTHERWISE...ISOLD TSRA ARE POSSIBLE OVER THE BLKHLS AND NERN WY IN
THE AFTN/EVNG...WITH SCT TSRA OVERNIGHT. MVFR CIGS/IFR VSBY WITH THE
TSRA.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
UPDATE...POJORLIE
SHORT TERM...13
LONG TERM...7
AVIATION...7
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
301 AM MDT WED AUG 5 2015
.SHORT TERM...TODAY THROUGH THURSDAY NIGHT
ISSUED AT 300 AM MDT WED AUG 5 2015
UPPER WAVE NOW CROSSING THE DAKOTAS WILL CONTINUE EWRD WITH
SUBSIDENCE BUILDING ACROSS THE CWA THIS MRNG. RELATIVELY LIGHT SRLY
FLOW WILL CONTINUE TODAY WITH TEMPS REACHING THE 80S TO LOWER 90S.
THE NEXT SHORTWAVE TROUGH IS MOVING ONSHORE THE PAC NW ATTM WITH A
SERIES OF UPPER WAVES ROUNDING THE BASE INTO THE NRN ROCKIES. THESE
WAVES WILL PUSH INTO WY THIS AFTN AND CROSS THE CWA TNGHT. MOST
AREAS WILL REMAIN DRY THIS MRNG...BUT POPS WILL INCREASE IN THE AFTN
INTO TONIGHT AS THE WAVE APPROACHES. HRRR SHOWS STORMS DEVELOPING
ACROSS NE WY/BLKHLS AREAS BY EARLY TO MID AFTN. STORMS ARE THEN
EXPECTED TO CROSS THE CWA TONIGHT AHEAD OF A WEAK FRONT CROSSING THE
AREA. A FEW STORMS COULD BE STRONG TO SEVERE W/ HAIL AND GUSTY
WINDS.
UPPER SYSTEM WILL PUSH EAST OF THE CWA THURSDAY MRNG WITH DRIER AND
SLIGHTLY COOLER AIR FILTERING IN FROM THE W/NW. STORMS MAY BE
LINGERING ACROSS CNTRL SD...BUT OTHERWISE MOST AREAS ARE EXPECTED TO
REMAIN DRY THROUGH THE DAY THUR. HIGHS WILL BE IN THE 80S ON THE
PLAINS...AND 70S ACROSS THE BLKHLS. SKIES WILL CLEAR OUT THROUGH THE
DAY...WITH MOSTLY CLEAR SKIES EXPECTED THU NIGHT. TEMPS WILL DROPS
INTO THE 50S TO LOW 60S.
.LONG TERM...FRIDAY THROUGH TUESDAY
ISSUED AT 300 AM MDT WED AUG 5 2015
ACTIVE PATTERN WILL CONTINUE AS LARGE SCALE RIDGING REMAINS
SUBDUED FOR MOST OF THE PERIOD. THIS WILL SUPPORT PERIODIC CHANCES
FOR SHOWERS AND THUNDERSTORMS AS A SERIES OF TROUGHS PUSH THROUGH
THE REGION. STRONGEST SYSTEM EXPECTED THIS WEEKEND... SUPPORTING
THE HIGHEST POPS SAT/SUN. SEASONAL TEMPS CAN BE EXPECTED THROUGH
THE WEEKEND. RIDGE BUILDS INTO THE NORTHERN PLAINS EARLY NEXT
WEEK...WITH WARMER/DRIER CONDITIONS.
&&
.AVIATION...FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING
ISSUED AT 300 AM MDT WED AUG 5 2015
SOME IFR CIGS/VSBYS MAY CREEP INTO SCNTRL SD EARLY THIS
MORNING FOG/STRATUS DEVELOP ACROSS NEB AND MOVES NWD.
OTHERWISE...ISOLD TSRA ARE POSSIBLE OVER THE BLKHLS AND NERN WY IN
THE AFTN/EVNG...WITH SCT TSRA OVERNIGHT. MVFR CIGS/IFR VSBY WITH THE
TSRA.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...13
LONG TERM...7
AVIATION...7
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1146 PM CDT TUE AUG 4 2015
.DISCUSSION...
UPDATED FOR 06Z AVIATION DISCUSSION
&&
.PREV DISCUSSION... /ISSUED 939 PM CDT TUE AUG 4 2015/
UPDATE...
LATEST HRRR AND NAM ARE IN PRETTY GOOD AGREEMENT THAT A LARGE AREA
OF SHOWERS AND THUNDERSTORMS WILL MOVE INTO AREAS ALONG AND WEST
OF THE MISSISSIPPI RIVER OVERNIGHT. LOOKING AT THE LATEST RADAR
IMAGES...A SMALL AREA OF SHOWERS AND THUNDERSTORMS IS CURRENTLY AFFECTING
NORTHERN ARKANSAS. THIS IS LIKELY THE BEGINNING OF THE DEVELOPMENT
THAT THE MODELS ARE PICKING UP ON. THUS EXPECT THE AREA TO EXPAND
OVER THE NEXT COUPLE OF HOURS. WILL UPDATE TO RAISE POPS.
KRM
DISCUSSION... /ISSUED 343 PM CDT TUE AUG 4 2015/
TEMPERATURES CLIMBED QUICKLY THIS MORNING UNDER SUNNY SKIES...BUT
LEVELED OUT MIDDAY AND ARE CURRENTLY WITHIN A DEGREE OR SO OF
WHERE WE WERE YESTERDAY AT THIS TIME. WE MAY STILL SEE ANOTHER
DEGREE OR TWO OF WARMING...ESPECIALLY IN NORTH MISSISSIPPI AND
PORTIONS OF WEST TENNESSEE...BUT WITH EVER INCREASING CLOUD COVER
MANY LOCATIONS HAVE LIKELY ALL REACHED THEIR AFTERNOON HIGHS. IF
THE FORECAST IS ACCURATE WE SHOULD NOT SEE TEMPERATURES THIS WARM
FOR SEVERAL DAYS...PERHAPS UNTIL SUNDAY OR MONDAY.
A STALLED FRONT REMAINS IN PLACE TO OUR NORTH...DRAPED ACROSS
CENTRAL MISSOURI. THE RIDGE RESPONSIBLE FOR THE RECENT HOT
TEMPERATURES WILL CONTINUE TO BREAK DOWN TONIGHT AND TOMORROW. AND
A FAIRLY STRONG SHORTWAVE FOR THIS TIME OF THE YEAR WILL TRACK OUT
OF THE PLAINS...SHIFTING ACROSS THE MIDSOUTH TOMORROW. ADDITIONAL
SMALLER IMPULSES WILL TRACK OVER THE AREA TOMORROW NIGHT AND
THURSDAY...BUT THE MAIN THREAT FOR ANY STRONG OR SEVERE STORMS
SHOULD BE TOMORROW AFTERNOON. THURSDAY AND FRIDAY...WE WILL BE
UNDER GENERIC NORTHWEST FLOW.
AS FOR THE SEVERE POTENTIAL...IT ISN`T LOOKING LIKE ANYTHING TO BE
OVERLY CONCERNED ABOUT. THERE WILL BE SOME ENHANCED SHEAR NEAR
AND AHEAD OF THE SHORTWAVE...BUT OTHERWISE DYNAMICS LOOK
UNIMPRESSIVE. DEW POINTS SHOULD BE IN THE LOW 70S WITH SURFACE
TEMPERATURES IN THE 80S TO NEAR 90 SUPPORTING CAPES OF UP TO 2500
J/KG. HOWEVER...IF RAIN IS ONGOING EARLY IN THE DAY...THIS AMOUNT
OF INSTABILITY MAY BE OPTIMISTIC.
THURSDAY AND FRIDAY STRONG STORMS MAY STILL BE POSSIBLE...BUT THE
OVERALL SEVERE THREAT SHOULD DIMINISH AS THE SHORTWAVE EXITS THE
REGION. BASIN AVERAGE RAINFALL TOTALS MIDWEEK THROUGH FRIDAY
SHOULD RANGE BETWEEN A THIRD OF AN INCH IN NORTH MISSISSIPPI TO
AS MUCH AS ONE INCH IN NORTHEAST ARKANSAS. LOCALLY HIGHER
ACCUMULATIONS ARE LIKELY WHERE INDIVIDUAL THUNDERSTORMS DEVELOP.
MOST OF THE WIDESPREAD RAIN CHANCES WILL COME TO AN END BY
SATURDAY AND TEMPERATURES WILL BEGIN TO REBOUND. GUIDANCE WANTS TO
BUILD THE RIDGE BACK IN SUNDAY INTO EARLY NEXT WEEK RESULTING IN
SIMILAR CONDITIONS TO WHAT WE SAW YESTERDAY AND TODAY.
30
&&
.AVIATION...
06Z TAF CYCLE
THICK CIRRUS ACROSS THE REGION SHOULD PREVENT FOG SO REMOVED THAT
FROM KMKL AND KTUP. CONVECTION CONTINUES TO DEVELOP ACROSS
SOUTHERN MISSOURI AND NORTHERN ARKANSAS. EXPECT SEVERAL
DISTURBANCES TO MOVE ACROSS THE MIDSOUTH OVER THE NEXT 24 HOURS.
FIRST DISTURBANCE SHOULD BRING SHRAS/TSRAS INTO KJBR AROUND
09Z...KMEM AT 12Z AND KMKL AT 14Z. THIS FIRST ROUND PROBABLY WILL
NOT REACH KTUP. SHOULD BE SOMEWHAT OF A BREAK THROUGH MUCH OF THE
DAY WITH SOME POPUP ACTIVITY BEFORE ANOTHER ROUND DEVELOPS IN THE
AFTERNOON AND WORKS ITS WAY SOUTHEAST INTO THE EARLY EVENING.
OUTSIDE OF SHRAS/TSRAS EXPECT VFR CONDS AND LIGHT AND VARIABLE
WINDS.
SJM
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
ISSUED BY NATIONAL WEATHER SERVICE LAKE CHARLES LA
107 PM CDT WED AUG 5 2015
.DISCUSSION...
FOR THE 05/18Z TAF ISSUANCE.
&&
.AVIATION...
SEA BREEZE ACTIVITY AS WELL AS SOME COASTAL SURFACE CONVERGENCE
WILL RESULT IN A FEW SHOWERS AND THUNDERSTORMS THIS AFTERNOON.
THEY WILL BE FEW AND FAR BETWEEN...SO THEREFORE ONLY HAVE VCNTY IN
TAFS. ANY AFTERNOON CONVECTION SHOULD DIMINISH WITH LOSS OF
DAYTIME HEATING. TOWARDS TOMORROW MORNING HOURS...ADDED MVFR TO
CLL/LBX TAF SITES. OTHERWISE...VFR REST OF TAF SITES.
&&
.PREV DISCUSSION... /ISSUED ISSUED BY NATIONAL WEATHER SERVICE LAKE CHARLES LA/
DISCUSSION...
SURFACE OBSERVATIONS AGAIN POINT TO AN EARLY WARMUP ON TAP
FOR THE REGION AS HIGH PRESSURE RIDGING REMAINS ANCHORED IN PLACE
ALOFT. SOUTHERLY FLOW IS BRINGING IN GULF LOW LEVEL MOISTURE IN
THE AREA WITH PLENTY OF MORNING LOW CLOUDS STREAMING ACROSS
SOUTHEAST TEXAS. RADAR SHOWED VERY LITTLE SHOWER ACTIVITY WITH
A FEW CELLS NOTED WEST AND NORTHWEST OF PALACIOS.
SEA BREEZE SHOULD KICK OFF A FEW SHOWERS AND THUNDERSTORMS LATER
THIS MORNING INTO THE LATE AFTERNOON...HOWEVER...WITH RIDGING HIGH
IN PLACE...SLIGHT POPS WILL GENERALLY HOLD I-10 CORRIDOR AREA AND
SOUTHWARD. CANNOT RULE OUT A RENEGADE STORM NORTH PART OF AREA
DURING MAXIMUM HEATING THIS AFTERNOON.
CURRENT FORECAST LOOKS GOOD...WILL NOT MAKE ANY CHANGES. 06
PREV DISCUSSION... /ISSUED 628 AM CDT WED AUG 5 2015/
DISCUSSION...
SEE 12Z AVIATION DISCUSSION.
AVIATION...
NAM 12 AND THE GFS NOT IN THE BEST AGREEMENT AGAIN THIS MORNING.
THE NAM 12 HAS PW VALUES SURGING TO 2.3 INCHES THIS AFTN WHILE THE
GFS IS AROUND 1.90 INCHES. THE LATEST HRRR SEEMS TO SUPPORT THE
NAM SO LEANED IN THAT DIRECTION. HAVE ADDED VCSH FOR SOUTHERN TAF
SITES INCLUDING KIAH. PRECIP SHOULD END BETWEEN 23-01Z. VFR CONDS
EXPECTED TODAY AND TONIGHT OUTSIDE OF ANY CONVECTION. 43
PREV DISCUSSION... /ISSUED 400 AM CDT WED AUG 5 2015/
DISCUSSION...
EARLY MORNING WATER VAPOR IMAGERY DEPICTS A COMPACT SHORTWAVE
TROUGH MOVING ACROSS THE CENTRAL PLAINS... WITH BROAD RIDGING IN
PLACE OVER THE SOUTHWESTERN CONUS AND TROUGHING ACROSS THE EAST.
THE EXTREMELY MOIST AIRMASS THAT MOVED ACROSS THE REGION YESTERDAY
WAS SEEN PUSHING INTO NORTHEAST TEXAS PER GOES SOUNDER IMAGERY
THIS MORNING. PRECIPITABLE WATER VALUES ACROSS THE REGION RANGED
FROM 2-2.2 INCHES OVER CROCKETT/TRINITY/POLK COUNTIES TO 1.5
INCHES AROUND MATAGORDA BAY... WITH SLIGHTLY HIGHER PWATS AROUND
1.7 TO 1.9 INCHES JUST OFFSHORE.
FOR TODAY... SOUTHERLY WINDS WILL AGAIN ADVECT THE HIGHER
MOISTURE AIR OVER THE GULF INTO THE REGION. THIS WILL PROVIDE
ENOUGH MOISTURE FOR ISOLATED SHOWERS AND THUNDERSTORMS TO DEVELOP
ALONG THE SEA BREEZE AS IT PUSHES INLAND LATE MORNING THROUGH LATE
AFTERNOON. CARRYING THE HIGHEST CHANCES /20 POPS/ ALONG AND SOUTH
OF THE INTERSTATE 10 CORRIDOR... BUT CANNOT RULE OUT A STRAY CELL
OR TWO PUSHING NORTH OF THAT AREA. PEAK HEAT INDEX VALUES
YESTERDAY TOPPED OUT AT 108 AT GALVESTON AND WITH SIMILAR
TEMPERATURES AND LOW LEVEL MOISTURE IN PLACE ACROSS THE REGION
TODAY... ANTICIPATE HEAT INDEX VALUES TO BE NEAR YESTERDAY/S AND
AGAIN BELOW HEAT ADVISORY CRITERIA. HOWEVER... WILL BE ISSUING A
SPECIAL WEATHER STATEMENT TO HIGHLIGHT THE HEAT FOR THE REMAINDER
OF THE WEEK AND INTO THE WEEKEND.
LOSS OF DAYTIME HEATING WILL PREVENT SEA BREEZE SHOWER AND
THUNDERSTORM ACTIVITY FROM MAKING IT TOO FAR INTO THE EVENING
HOURS... BUT WILL NEED TO CONTINUE TO WATCH THE EVOLUTION OF THE
SHORTWAVE OVER THE CENTRAL PLAINS. THE NCEP 4 KM WRF ACTUALLY
BRINGS A THIN LINE OF THUNDERSTORMS TONIGHT INTO THE PINEY WOODS
REGION AS THIS SHORTWAVE DIVES TOWARDS THE LOWER MISSISSIPPI RIVER
TONIGHT. THIS MODEL IS INITIALIZED FROM THE 40 KM NAM... WHICH HAS
CONSISTENTLY BEEN AN OUTLIER WITH THE SOUTHERNMOST TRAJECTORY FOR
THIS SHORTWAVE OVER THE PAST FEW RUNS. 00Z GUIDANCE /INCLUDING THE
NAM/ DID NOT INITIALIZE TOO TERRIBLY WITH THE PLACEMENT OF THIS
SHORTWAVE. HOWEVER... GIVEN THAT THIS SOLUTION IS AN OUTLIER AND
THE MAJORITY OF GUIDANCE KEEPS THE SHORTWAVE TOO FAR NORTH OF THE
REGION TO RAISE ANY REAL CONCERNS FOR RAIN CHANCES THIS EVENING...
KEEPING THE FORECAST DRY FOR NOW. OTHERWISE... ANOTHER WARM AND
QUIET NIGHT EXPECTED FOR THE REGION.
THE UPPER RIDGE OVER THE SOUTHWESTERN CONUS WILL CONTINUE TO
SHIFT EASTWARD OVER THE NEXT 24 HOURS... CENTERING OVER EASTERN
NM/WEST TX ON THURSDAY. INCREASING HEIGHTS ALOFT WILL SERVE TO
INCREASE TEMPERATURES ACROSS THE REGION WITH HEAT ADVISORIES
POTENTIALLY NEEDED AS EARLY AS THURSDAY. BY THE WEEKEND... THE
UPPER RIDGE PARKS ITSELF OVER NORTH/NORTHEAST TEXAS AND PROLONGS
THE HEAT WITH INLAND TEMPERATURES RISING INTO THE LOW 100S THIS
WEEKEND. THOSE WITH OUTDOOR PLANS THIS WEEKEND WILL WANT TO TAKE
EXTREME CAUTION TO PREVENT HEAT ILLNESSES. LOOKING AHEAD TO NEXT
WEEK... MEDIUM RANGE GUIDANCE DOES ATTEMPT TO BRING A FRONTAL
SYSTEM OUT OF THE GREAT PLAINS WITH THE PROMISE FOR LOW RAIN
CHANCES BY THE MIDDLE OF NEXT WEEK.
HUFFMAN
MARINE...
HIGH PRESSURE OVER THE EASTERN GULF AND LOWER PRESSURE OVER THE
SOUTHERN PLAINS WILL MAINTAIN A LIGHT TO MODERATE ONSHORE FLOW
THROUGH THE WEEKEND. THERE WILL BE SUBTLE DIURNAL VARIATIONS WITH
SLIGHTLY STRONGER WINDS AT NIGHT AND A BRIEF S-SW COMPONENT TO THE
DIRECTION EACH MORNING. 43
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 99 77 100 78 101 / 10 10 10 10 0
HOUSTON (IAH) 97 79 98 80 99 / 20 10 10 10 10
GALVESTON (GLS) 92 82 91 82 92 / 10 10 10 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...99
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1219 PM CDT WED AUG 5 2015
.AVIATION.../18Z TAFS/
DOMINATE HIGH PRESSURE RESULTING IN VFR CONDITIONS ACROSS ALL TAF
SITES THIS AFTERNOON AND EVENING. MVFR CIGS ONCE AGAIN EXPECTED TO
DEVELOP AT THE I-35 CORRIDOR TAFS BETWEEN 09Z-11Z OVERNIGHT AND
BECOMING SCATTERED/VFR BY 14Z-15Z. GENERAL SOUTHERLY WINDS TO
CONTINUE AT 5 TO 15 KTS WITH A FEW GUSTS OF 18-20KTS MAINLY LATE
AFTERNOON AND EARLY EVENING.
&&
.PREV DISCUSSION... /ISSUED 704 AM CDT WED AUG 5 2015/
AVIATION.../12Z TAFS/
PATCHY MVFR CIGS WILL CONTINUE TO AFFECT THE I-35 TAF SITES
THROUGH 14Z AS THEY BOUNCE BETWEEN SCT AND BKN COVERAGE SIMILAR TO
YESTERDAY MORNING. HOWEVER...THE HRRR SUGGESTS THESE LOW CLOUDS
WILL LIFT TO VFR WITHIN THE HOUR...SO WILL AMEND TAFS AS NECESSARY
IF THIS OCCURS. SOUTHERLY 10-15 KT WINDS WITH BRIEF GUSTS TO 20
KTS ARE POSSIBLE THIS AFTERNOON. BRIEF PATCHY MVFR CIGS SHOULD
DEVELOP AGAIN TOMORROW MORNING AT ONE OR TWO OF THE I-35 SITES.
PREV DISCUSSION... /ISSUED 319 AM CDT WED AUG 5 2015/
SHORT TERM (TODAY THROUGH THURSDAY)...
UPPER LEVEL RIDGE WILL BEGIN ITS EASTWARD TREK BACK TO THE SOUTH
CENTRAL CONUS TODAY RESULTING IN BUILDING HEIGHTS ACROSS THE
REGION. MORNING LOW CLOUDS DUE TO SLIGHTLY BETTER MOISTURE
ADVECTION THIS MORNING WILL QUICKLY BURN OFF AS MIXING WILL
EFFICIENTLY TAKE PLACE AS SURFACE TEMPERATURES WARM. EXPECTING
HIGHS TO AVERAGE ABOUT A DEGREE OR SO HIGHER TODAY THAN YESTERDAY
ACROSS THE CWA. HEAT INDICES WILL RANGE FROM 102 IN THE HILL
COUNTRY TO 111 IN THE RIO GRANDE VALLEY.
LONG TERM (THURSDAY NIGHT THROUGH TUESDAY)...
THE UPPER RIDGE WILL CONTINUE TO SHIFT EAST AND GET COMFY OVER
TEXAS FOR THE WEEKEND. 1000-500MB THICKNESSES LOOK TO INCREASE
ABOUT 7-8 DAM FROM TODAY THROUGH SATURDAY RESULTING IN SATURDAY
HIGHS IN THE TRIPLE DIGITS EVERYWHERE BUT IN THE HIGHER TERRAIN OF
THE PLATEAU. THIS SET UP WILL CONTINUE THROUGH AT LEAST WEDNESDAY
BEFORE SOME HINTS AT A FRONTAL SYSTEM ARE SEEN IN THE GFS/ECMWF.
HOWEVER...RATHER THAN COOL THE AREA...THE FRONTAL SYSTEM MAY SERVE
TO ONLY PROVIDE ADDITIONAL COMPRESSIONAL WARMING AND RAISE MAX
TEMPS TO AT OR JUST ABOVE RECORD HIGHS FOR NEXT WEDNESDAY. BASED
OFF THE CURRENT FORECAST...HEAT ADVISORIES WILL LIKELY BE NEEDED
FOR AREAS IN SOUTH CENTRAL TEXAS...ESPECIALLY THE EASTERN ZONES
AND COASTAL PLAINS POSSIBLY BEGINNING AS EARLY AS FRIDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 101 76 100 77 101 / 0 0 0 0 0
AUSTIN BERGSTROM INTL AIRPORT 99 74 99 74 101 / 0 0 0 0 0
NEW BRAUNFELS MUNI AIRPORT 101 75 100 75 101 / 0 0 0 0 0
BURNET MUNI AIRPORT 100 75 100 76 101 / 0 0 0 0 0
DEL RIO INTL AIRPORT 102 77 102 78 103 / 0 0 0 0 0
GEORGETOWN MUNI AIRPORT 100 76 100 77 101 / 0 0 0 0 0
HONDO MUNI AIRPORT 99 74 99 75 100 / 0 0 0 0 0
SAN MARCOS MUNI AIRPORT 100 76 99 75 100 / 0 0 0 0 0
LA GRANGE - FAYETTE REGIONAL 100 77 99 77 101 / - 0 0 0 0
SAN ANTONIO INTL AIRPORT 100 77 99 77 100 / 0 0 0 0 0
STINSON MUNI AIRPORT 100 77 100 76 101 / 0 0 0 0 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...07
SYNOPTIC/GRIDS...OAKS
PUBLIC SERVICE/DATA COLLECTION...TREADWAY
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
704 AM CDT WED AUG 5 2015
.AVIATION.../12Z TAFS/
PATCHY MVFR CIGS WILL CONTINUE TO AFFECT THE I-35 TAF SITES
THROUGH 14Z AS THEY BOUNCE BETWEEN SCT AND BKN COVERAGE SIMILAR TO
YESTERDAY MORNING. HOWEVER...THE HRRR SUGGESTS THESE LOW CLOUDS
WILL LIFT TO VFR WITHIN THE HOUR...SO WILL AMEND TAFS AS NECESSARY
IF THIS OCCURS. SOUTHERLY 10-15 KT WINDS WITH BRIEF GUSTS TO 20
KTS ARE POSSIBLE THIS AFTERNOON. BRIEF PATCHY MVFR CIGS SHOULD
DEVELOP AGAIN TOMORROW MORNING AT ONE OR TWO OF THE I-35 SITES.
&&
.PREV DISCUSSION... /ISSUED 319 AM CDT WED AUG 5 2015/
SHORT TERM (TODAY THROUGH THURSDAY)...
UPPER LEVEL RIDGE WILL BEGIN ITS EASTWARD TREK BACK TO THE SOUTH
CENTRAL CONUS TODAY RESULTING IN BUILDING HEIGHTS ACROSS THE
REGION. MORNING LOW CLOUDS DUE TO SLIGHTLY BETTER MOISTURE
ADVECTION THIS MORNING WILL QUICKLY BURN OFF AS MIXING WILL
EFFICIENTLY TAKE PLACE AS SURFACE TEMPERATURES WARM. EXPECTING
HIGHS TO AVERAGE ABOUT A DEGREE OR SO HIGHER TODAY THAN YESTERDAY
ACROSS THE CWA. HEAT INDICES WILL RANGE FROM 102 IN THE HILL
COUNTRY TO 111 IN THE RIO GRANDE VALLEY.
LONG TERM (THURSDAY NIGHT THROUGH TUESDAY)...
THE UPPER RIDGE WILL CONTINUE TO SHIFT EAST AND GET COMFY OVER
TEXAS FOR THE WEEKEND. 1000-500MB THICKNESSES LOOK TO INCREASE
ABOUT 7-8 DAM FROM TODAY THROUGH SATURDAY RESULTING IN SATURDAY
HIGHS IN THE TRIPLE DIGITS EVERYWHERE BUT IN THE HIGHER TERRAIN OF
THE PLATEAU. THIS SET UP WILL CONTINUE THROUGH AT LEAST WEDNESDAY
BEFORE SOME HINTS AT A FRONTAL SYSTEM ARE SEEN IN THE GFS/ECMWF.
HOWEVER...RATHER THAN COOL THE AREA...THE FRONTAL SYSTEM MAY SERVE
TO ONLY PROVIDE ADDITIONAL COMPRESSIONAL WARMING AND RAISE MAX
TEMPS TO AT OR JUST ABOVE RECORD HIGHS FOR NEXT WEDNESDAY. BASED
OFF THE CURRENT FORECAST...HEAT ADVISORIES WILL LIKELY BE NEEDED
FOR AREAS IN SOUTH CENTRAL TEXAS...ESPECIALLY THE EASTERN ZONES
AND COASTAL PLAINS POSSIBLY BEGINNING AS EARLY AS FRIDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 101 76 100 77 101 / 0 0 0 0 0
AUSTIN BERGSTROM INTL AIRPORT 99 74 99 74 101 / 0 0 0 0 0
NEW BRAUNFELS MUNI AIRPORT 101 75 100 75 101 / 0 0 0 0 0
BURNET MUNI AIRPORT 100 75 100 76 101 / 0 0 0 0 0
DEL RIO INTL AIRPORT 102 77 102 78 103 / 0 0 0 0 0
GEORGETOWN MUNI AIRPORT 100 76 100 77 101 / 0 0 0 0 0
HONDO MUNI AIRPORT 99 74 99 75 100 / 0 0 0 0 0
SAN MARCOS MUNI AIRPORT 100 76 99 75 100 / 0 0 0 0 0
LA GRANGE - FAYETTE REGIONAL 100 77 99 77 101 / - 0 0 0 0
SAN ANTONIO INTL AIRPORT 100 77 99 77 100 / 0 0 0 0 0
STINSON MUNI AIRPORT 100 77 100 76 101 / 0 0 0 0 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...LH
SYNOPTIC/GRIDS...TB3
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
628 AM CDT WED AUG 5 2015
.DISCUSSION...
SEE 12Z AVIATION DISCUSSION.
&&
.AVIATION...
NAM 12 AND THE GFS NOT IN THE BEST AGREEMENT AGAIN THIS MORNING.
THE NAM 12 HAS PW VALUES SURGING TO 2.3 INCHES THIS AFTN WHILE THE
GFS IS AROUND 1.90 INCHES. THE LATEST HRRR SEEMS TO SUPPORT THE
NAM SO LEANED IN THAT DIRECTION. HAVE ADDED VCSH FOR SOUTHERN TAF
SITES INCLUDING KIAH. PRECIP SHOULD END BETWEEN 23-01Z. VFR CONDS
EXPECTED TODAY AND TONIGHT OUTSIDE OF ANY CONVECTION. 43
&&
.PREV DISCUSSION... /ISSUED 400 AM CDT WED AUG 5 2015/
DISCUSSION...
EARLY MORNING WATER VAPOR IMAGERY DEPICTS A COMPACT SHORTWAVE
TROUGH MOVING ACROSS THE CENTRAL PLAINS... WITH BROAD RIDGING IN
PLACE OVER THE SOUTHWESTERN CONUS AND TROUGHING ACROSS THE EAST.
THE EXTREMELY MOIST AIRMASS THAT MOVED ACROSS THE REGION YESTERDAY
WAS SEEN PUSHING INTO NORTHEAST TEXAS PER GOES SOUNDER IMAGERY
THIS MORNING. PRECIPITABLE WATER VALUES ACROSS THE REGION RANGED
FROM 2-2.2 INCHES OVER CROCKETT/TRINITY/POLK COUNTIES TO 1.5
INCHES AROUND MATAGORDA BAY... WITH SLIGHTLY HIGHER PWATS AROUND
1.7 TO 1.9 INCHES JUST OFFSHORE.
FOR TODAY... SOUTHERLY WINDS WILL AGAIN ADVECT THE HIGHER
MOISTURE AIR OVER THE GULF INTO THE REGION. THIS WILL PROVIDE
ENOUGH MOISTURE FOR ISOLATED SHOWERS AND THUNDERSTORMS TO DEVELOP
ALONG THE SEA BREEZE AS IT PUSHES INLAND LATE MORNING THROUGH LATE
AFTERNOON. CARRYING THE HIGHEST CHANCES /20 POPS/ ALONG AND SOUTH
OF THE INTERSTATE 10 CORRIDOR... BUT CANNOT RULE OUT A STRAY CELL
OR TWO PUSHING NORTH OF THAT AREA. PEAK HEAT INDEX VALUES
YESTERDAY TOPPED OUT AT 108 AT GALVESTON AND WITH SIMILAR
TEMPERATURES AND LOW LEVEL MOISTURE IN PLACE ACROSS THE REGION
TODAY... ANTICIPATE HEAT INDEX VALUES TO BE NEAR YESTERDAY/S AND
AGAIN BELOW HEAT ADVISORY CRITERIA. HOWEVER... WILL BE ISSUING A
SPECIAL WEATHER STATEMENT TO HIGHLIGHT THE HEAT FOR THE REMAINDER
OF THE WEEK AND INTO THE WEEKEND.
LOSS OF DAYTIME HEATING WILL PREVENT SEA BREEZE SHOWER AND
THUNDERSTORM ACTIVITY FROM MAKING IT TOO FAR INTO THE EVENING
HOURS... BUT WILL NEED TO CONTINUE TO WATCH THE EVOLUTION OF THE
SHORTWAVE OVER THE CENTRAL PLAINS. THE NCEP 4 KM WRF ACTUALLY
BRINGS A THIN LINE OF THUNDERSTORMS TONIGHT INTO THE PINEY WOODS
REGION AS THIS SHORTWAVE DIVES TOWARDS THE LOWER MISSISSIPPI RIVER
TONIGHT. THIS MODEL IS INITIALIZED FROM THE 40 KM NAM... WHICH HAS
CONSISTENTLY BEEN AN OUTLIER WITH THE SOUTHERNMOST TRAJECTORY FOR
THIS SHORTWAVE OVER THE PAST FEW RUNS. 00Z GUIDANCE /INCLUDING THE
NAM/ DID NOT INITIALIZE TOO TERRIBLY WITH THE PLACEMENT OF THIS
SHORTWAVE. HOWEVER... GIVEN THAT THIS SOLUTION IS AN OUTLIER AND
THE MAJORITY OF GUIDANCE KEEPS THE SHORTWAVE TOO FAR NORTH OF THE
REGION TO RAISE ANY REAL CONCERNS FOR RAIN CHANCES THIS EVENING...
KEEPING THE FORECAST DRY FOR NOW. OTHERWISE... ANOTHER WARM AND
QUIET NIGHT EXPECTED FOR THE REGION.
THE UPPER RIDGE OVER THE SOUTHWESTERN CONUS WILL CONTINUE TO
SHIFT EASTWARD OVER THE NEXT 24 HOURS... CENTERING OVER EASTERN
NM/WEST TX ON THURSDAY. INCREASING HEIGHTS ALOFT WILL SERVE TO
INCREASE TEMPERATURES ACROSS THE REGION WITH HEAT ADVISORIES
POTENTIALLY NEEDED AS EARLY AS THURSDAY. BY THE WEEKEND... THE
UPPER RIDGE PARKS ITSELF OVER NORTH/NORTHEAST TEXAS AND PROLONGS
THE HEAT WITH INLAND TEMPERATURES RISING INTO THE LOW 100S THIS
WEEKEND. THOSE WITH OUTDOOR PLANS THIS WEEKEND WILL WANT TO TAKE
EXTREME CAUTION TO PREVENT HEAT ILLNESSES. LOOKING AHEAD TO NEXT
WEEK... MEDIUM RANGE GUIDANCE DOES ATTEMPT TO BRING A FRONTAL
SYSTEM OUT OF THE GREAT PLAINS WITH THE PROMISE FOR LOW RAIN
CHANCES BY THE MIDDLE OF NEXT WEEK.
HUFFMAN
MARINE...
HIGH PRESSURE OVER THE EASTERN GULF AND LOWER PRESSURE OVER THE
SOUTHERN PLAINS WILL MAINTAIN A LIGHT TO MODERATE ONSHORE FLOW
THROUGH THE WEEKEND. THERE WILL BE SUBTLE DIURNAL VARIATIONS WITH
SLIGHTLY STRONGER WINDS AT NIGHT AND A BRIEF S-SW COMPONENT TO THE
DIRECTION EACH MORNING. 43
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 99 77 100 78 101 / 10 10 10 10 0
HOUSTON (IAH) 97 79 98 80 99 / 20 10 10 10 10
GALVESTON (GLS) 92 82 91 82 92 / 10 10 10 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...14
AVIATION/MARINE...43
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
735 PM EDT THU AUG 6 2015
.SYNOPSIS...
LOW PRESSURE WILL MOVE THROUGH THE MOUNTAINS OF VIRGINIA AND
NORTH CAROLINA...AND INTO THE COASTAL PLAIN OF THE CAROLINAS
TONIGHT... BRINGING SHOWERS AND THUNDERSTORMS TO THE REGION. AS
THE LOW LINGERS OVER THE CAROLINAS ON FRIDAY...NORTHEASTERLY
WINDS WILL BRING COOLER TEMPERATURES AND A CONTINUED CHANCE OF
SHOWERS AND THUNDERSTORMS. CONDITIONS WILL GRADUALLY IMPROVE
THROUGH THE WEEKEND AS THE LOW MOVES OFF THE MIDDLE ATLANTIC COAST
AND HIGH PRESSURE BUILDS IN FROM THE OHIO VALLEY.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 630 PM EDT FRIDAY...
NOT AS EXTENSIVE OF COVERAGE OVER THE NRN CWA AND ERN CWA. THE
HIGH-RES MODELS ESPECIALLY THE RAP FROM 20Z HAD A GOOD HANDLE ON
THE BETTER AREAS OF DEEP MOISTURE CONVERGENCE. FOLLOWED THE POPS
TRENDS BASED ON THIS THROUGH THE EVENING WHICH FAVORS THE SE WV TO
NC MTNS/FOOTHILLS CORRIDOR WITH HIGHER POPS AS WELL AS PORTIONS
OF THE PIEDMONT OF VA/NC...WITH LESS COVERAGE TOWARD THE
ALLEGHANYS AND SHENANDOAH VALLEY. STILL OVERNIGHT WE GET BETTER
UPPER SUPPORT MOVING INTO THE SW CWA...SO HAVE ADJUSTED HIGHER
POPS OVER THE SRN CWA AS OPPOSED TO THE NORTH. NO OTHER MAJOR
CHANGES TO THE OTHER FORECAST ELEMENTS.
THE SVR THREAT STILL LOOKS MARGINAL AT BEST WITH HIGHEST MLCAPES
SITUATED IN THE TRIAD AREA OF NC OF 1500 J/KG AT 22Z. WILL HAVE TO
WATCH FOR STRONG STORMS MAINLY FROM THE WILKES/YADKIN AREA
NORTHEAST TOWARD DANVILLE/SOUTH BOSTON. STORMS WERE MOVING AT 10
TO 20 MPH...BUT DECENT RAINFALL RATES ON ONE CELL OF 50-55DBZ CAME
ACROSS OUR OFFICE AND GAVE US CLOSE TO ONE HALF INCH IN LESS THAN
30 MINUTES. OUR RADAR IS DOING A GOOD JOB OF RADAR
ESTIMATES.
PREVIOUS DISCUSSION...
LATEST INDICATIONS ARE THAT THE FRONTAL BOUNDARY DRAPED ACROSS
THE REGION HAS TAKEN UP RESIDENCE ALONG THE SOUTHERN BORDER OF THE
CWA. THUS FAR THIS HAS SUPPRESSED THE MOST UNSTABLE AIR TO OUR
SOUTH AND DEEP CONVECTIVE DEVELOPMENT HAS OCCURRED FROM THE TRIAD
OF NC SOUTHWARD. HOWEVER...THE LATEST SATELLITE IMAGES SHOW THAT
THE CLOUDY SKIES THAT HAVE INHIBITED SURFACE HEATING AND
ASSOCIATED DESTABILIZATION HAS ERODED SIGNIFICANTLY. BELIEVE THIS
WILL CREATE ENOUGH SURFACE BASED INSTABILITY TO GENERATE
CONVECTION OVER OUR AREA AS THE BEST DYNAMICS ASSOCIATED WITH THE
VIGOROUS UPPER LEVEL SHORT WAVE WILL NOT ARRIVE UNTIL THIS
EVENING/EARLY TONIGHT. WITH THIS IN MIND...WILL CONTINUE WITH A
FORECAST ADVERTISING HIGH POPS WITH THE EXPECTATION FOR MOST OF
THE ACTIVITY TO OCCUR IN A WINDOW OF ROUGHLY 22Z-04Z. THE BEST
SEVERE THREAT WILL REMAIN TO OUR SOUTH IN THE MOST UNSTABLE
ENVIRONMENT...BUT THERE LOOKS TO BE IS ENOUGH DEVELOPING
INSTABILITY AND SHEAR IN THE VICINITY OF THE FRONTAL BOUNDARY TO
KEEP A MARGINAL THREAT EAST OF THE BLUE RIDGE ACROSS THE PIEDMONT
OF VA/NC. LOCALLY HEAVY RAIN ALSO STILL A GOOD BET WITH
PRECIPITABLE WATER VALUES RUNNING ABOVE 1.5 INCHES...SO LOCALIZED
FLOODING PROBLEMS REMAIN A POSSIBILITY THROUGH THIS EVENING INTO
EARLY TONIGHT.
AS THE LOW PUSHES THROUGH THE MOUNTAINS AND INTO THE COASTAL PLAIN
OF THE CAROLINAS TONIGHT...NELY FLOW WILL BRING CLOUDS AND
LINGERING SHOWERS TO THE REGION OVERNIGHT. AS THE LOW SITS AND
SPINS TO OUR SOUTHEAST ON FRIDAY...WE WILL STAY IN A COOL NELY
FLOW WITH WRAP AROUND MOISTURE BEING PULLED INTO THE AREA. THIS
WILL BE ENOUGH TO GENERATE SCATTERED SHOWERS AND IF WE CAN MANAGE
ENOUGH SUN TO CREATE SOME SURFACE BASED INSTABILITY...SOME THUNDER
CAN MATERIALIZE AS WELL.
TEMPERATURES TONIGHT WILL GENERALLY BE IN THE UPPER 60S/AROUND 70 EAST
OF THE RIDGE TO THE LOW/MID 60S WEST. HIGHS ON FRIDAY WILL BE
SUPPRESSED A BIT WITH CLOUDS AND A COOL NELY FLOW SO READINGS OF
MID/UPPER 70S EAST TO UPPER 60S/LOWER 70S WEST SHOULD DO IT.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
AS OF 330 PM EDT FRIDAY...
SURFACE LOW PRESSURE OVER THE CAROLINAS WILL DEEPEN AND MOVE
NORTHEAST THROUGH SUNDAY MORNING AIDED BY ANOTHER SHORT WAVE
TRACKING DOWN THE WESTERN SIDE OF THE UPPER TROF.
MODELS HOLD MOISTURE IN THE REGION THROUGH THE WEEKEND. BEST AREAL
COVERAGE OF PRECIPITATION WILL BE MOVING EAST OUT OF THE FORECAST
AREA WITH THE LOW ON FRIDAY NIGHT...BUT ENOUGH INSTABILITY OF
MOISTURE IN THE FAR WESTERN COUNTY WARNING AREA SATURDAY AFTERNOON
AND SUNDAY AFTERNOON FOR ISOLATED SHOWERS AND THUNDERSTORMS.
HOWEVER...ON FRIDAY NIGHT AND SATURDAY EAST TO NORTHEAST WINDS FROM
THE SURFACE THROUGH AROUND 700 MB MAY KEEP ENOUGH MOISTURE AND LIFT
EAST OF THE BLUE RIDGE FOR LOW CLOUDS ALONG WITH SPOTTY LIGHT RAIN
AND DRIZZLE.
BY SUNDAY LOW WILL BE FAR ENOUGH OFF THE COAST FOR LIGHTER NORTHEAST
WINDS IN THE EASTERN COUNTY WARNING AREA. HIGH PRESSURE/IN-SITU TYPE
WEDGE WILL BE OVER SOUTHWEST VIRGINIA...IN BETWEEN THE LOW OFFSHORE
AND AN INVERTED TROF OVER THE OHIO AND TENNESSEE VALLEYS.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 330 PM EDT FRIDAY...
HIGH AMPLITUDE 500 MB WILL DEVELOP THIS TIME FRAME WITH A CLOSED LOW
OVER THE PACIFIC NW...A LARGE RIDGE CENTERED ALONG THE ROCKIES AND A
DEEP TROF/CLOSED LOW OVER THE EASTERN THIRD OF THE COUNTRY.
THE MAIN TROF AXIS WAS SLIGHTLY SLOWER ON THE 00Z SUITE OF GUIDANCE
BUT STILL EXPECTING THE SURFACE FRONT TO CROSS THROUGH THE MID
ATLANTIC REGION ON TUESDAY. LOW DEEPENS AND MOVES NORTHEAST ALONG
THE COAST TUESDAY THROUGH WEDNESDAY. 00Z ECMWF WAS ADVERTISING A
RELATIVELY COOLER AIR MASS BEHIND THE FRONT. BEHIND THIS
SYSTEM...LOW LEVEL MOISTURE REMAINS OVER THE AREA...ESPECIALLY IN THE
MOUNTAINS THROUGH WEDNESDAY. BEST PROBABILITY OF PRECIPITATION WILL
BE AHEAD OF THE FRONT ON MONDAY AND ALONG THE FRONT ON TUESDAY. THEN
AIR MASS DRIES OUT. PRECIPITABLE WATER VALUES DROP BELOW AN INCH.
HAVE DRY FORECAST FOR MUCH OF THE COUNTY WARNING AREA ON WEDNESDAY
AND THURSDAY.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
AS OF 729 PM EDT THURSDAY...
NOT A GOOD AVIATION SETUP FOR TONIGHT INTO FRIDAY AS MODELS FAVOR
A NEARLY STATIONARY BOUNDARY FROM SE KY INTO THE VA TIDEWATER TO
KEEP SHOWERS AND STORMS AROUND THIS EVENING...WITH MOST COVERAGE
OVERNIGHT...WITH LESS THUNDER. USED RADAR TRENDS TO CONSTRUCT TAFS
FOR THE FIRST 4 HOURS...THEN MODEL BLEND AND HIGH RES TO GO WITH
MAINLY SHOWERS WITH IFR/MVFR CIGS OVERNIGHT INTO FRIDAY MORNING.
FRIDAY...THE FRONT EXITS EAST AS THE MAIN LOW DEVELOPS OVER THE
NC COAST. DEEPER MOISTURE WILL STAY EAST OF US BUT WILL STAY IN A
MOIST AIRMASS IN A NE TO N FLOW IN THE LOW LVLS...SUCH THAT MOST
AREAS WILL KEEP LOWER CIGS INTO MIDDAY. BY THE AFTERNOON THE CIGS
ARE EXPECTED TO IMPROVE OVER BLF BUT THINK THE REST OF THE
TERMINALS KEEP AT LEAST MVFR CIGS...WITH LESS THREAT OF SHOWERS.
CONFIDENCE IS NOT THAT HIGH AS CONDITIONS WILL BE VARIABLE THROUGH
THE NIGHT...BUT HIGH ENOUGH TO KEEP SUB VFR IN THROUGH MOST OF THE
TAF PERIOD.
EXTENDED AVIATION FORECAST...
OVER THE WEEKEND...VFR CONDITIONS RETURN TO MOST LOCATIONS AS HIGH
PRESSURE BUILDS INTO AND OVER THE REGION. LATE NIGHT AND EARLY
MORNING MOUNTAIN AND RIVER VALLEY FOG IS POSSIBLE.
EARLY NEXT WEEK A FRONT EXPECTED TO BE MOVING INTO THE REGION SO
MONDAY/TUESDAY AT THIS TIME LOOKS STORMY BUT NOT A COMPLETE
WASHOUT...WITH SUB VFR ONLY IN STORMS...AND ANY FOG AT NIGHT.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...MBS
NEAR TERM...MBS/WP
SHORT TERM...AMS
LONG TERM...AMS
AVIATION...MBS/PM/WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
700 PM EDT THU AUG 6 2015
.SYNOPSIS...
LOW PRESSURE WILL MOVE THROUGH THE MOUNTAINS OF VIRGINIA AND
NORTH CAROLINA...AND INTO THE COASTAL PLAIN OF THE CAROLINAS
TONIGHT... BRINGING SHOWERS AND THUNDERSTORMS TO THE REGION. AS
THE LOW LINGERS OVER THE CAROLINAS ON FRIDAY...NORTHEASTERLY
WINDS WILL BRING COOLER TEMPERATURES AND A CONTINUED CHANCE OF
SHOWERS AND THUNDERSTORMS. CONDITIONS WILL GRADUALLY IMPROVE
THROUGH THE WEEKEND AS THE LOW MOVES OFF THE MIDDLE ATLANTIC COAST
AND HIGH PRESSURE BUILDS IN FROM THE OHIO VALLEY.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 630 PM EDT FRIDAY...
NOT AS EXTENSIVE OF COVERAGE OVER THE NRN CWA AND ERN CWA. THE
HIGH-RES MODELS ESPECIALLY THE RAP FROM 20Z HAD A GOOD HANDLE ON
THE BETTER AREAS OF DEEP MOISTURE CONVERGENCE. FOLLOWED THE POPS
TRENDS BASED ON THIS THROUGH THE EVENING WHICH FAVORS THE SE WV TO
NC MTNS/FOOTHILLS CORRIDOR WITH HIGHER POPS AS WELL AS PORTIONS
OF THE PIEDMONT OF VA/NC...WITH LESS COVERAGE TOWARD THE
ALLEGHANYS AND SHENANDOAH VALLEY. STILL OVERNIGHT WE GET BETTER
UPPER SUPPORT MOVING INTO THE SW CWA...SO HAVE ADJUSTED HIGHER
POPS OVER THE SRN CWA AS OPPOSED TO THE NORTH. NO OTHER MAJOR
CHANGES TO THE OTHER FORECAST ELEMENTS.
THE SVR THREAT STILL LOOKS MARGINAL AT BEST WITH HIGHEST MLCAPES
SITUATED IN THE TRIAD AREA OF NC OF 1500 J/KG AT 22Z. WILL HAVE TO
WATCH FOR STRONG STORMS MAINLY FROM THE WILKES/YADKIN AREA
NORTHEAST TOWARD DANVILLE/SOUTH BOSTON. STORMS WERE MOVING AT 10
TO 20 MPH...BUT DECENT RAINFALL RATES ON ONE CELL OF 50-55DBZ CAME
ACROSS OUR OFFICE AND GAVE US CLOSE TO ONE HALF INCH IN LESS THAN
30 MINUTES. OUR RADAR IS DOING A GOOD JOB OF RADAR
ESTIMATES.
PREVIOUS DISCUSSION...
LATEST INDICATIONS ARE THAT THE FRONTAL BOUNDARY DRAPED ACROSS
THE REGION HAS TAKEN UP RESIDENCE ALONG THE SOUTHERN BORDER OF THE
CWA. THUS FAR THIS HAS SUPPRESSED THE MOST UNSTABLE AIR TO OUR
SOUTH AND DEEP CONVECTIVE DEVELOPMENT HAS OCCURRED FROM THE TRIAD
OF NC SOUTHWARD. HOWEVER...THE LATEST SATELLITE IMAGES SHOW THAT
THE CLOUDY SKIES THAT HAVE INHIBITED SURFACE HEATING AND
ASSOCIATED DESTABILIZATION HAS ERODED SIGNIFICANTLY. BELIEVE THIS
WILL CREATE ENOUGH SURFACE BASED INSTABILITY TO GENERATE
CONVECTION OVER OUR AREA AS THE BEST DYNAMICS ASSOCIATED WITH THE
VIGOROUS UPPER LEVEL SHORT WAVE WILL NOT ARRIVE UNTIL THIS
EVENING/EARLY TONIGHT. WITH THIS IN MIND...WILL CONTINUE WITH A
FORECAST ADVERTISING HIGH POPS WITH THE EXPECTATION FOR MOST OF
THE ACTIVITY TO OCCUR IN A WINDOW OF ROUGHLY 22Z-04Z. THE BEST
SEVERE THREAT WILL REMAIN TO OUR SOUTH IN THE MOST UNSTABLE
ENVIRONMENT...BUT THERE LOOKS TO BE IS ENOUGH DEVELOPING
INSTABILITY AND SHEAR IN THE VICINITY OF THE FRONTAL BOUNDARY TO
KEEP A MARGINAL THREAT EAST OF THE BLUE RIDGE ACROSS THE PIEDMONT
OF VA/NC. LOCALLY HEAVY RAIN ALSO STILL A GOOD BET WITH
PRECIPITABLE WATER VALUES RUNNING ABOVE 1.5 INCHES...SO LOCALIZED
FLOODING PROBLEMS REMAIN A POSSIBILITY THROUGH THIS EVENING INTO
EARLY TONIGHT.
AS THE LOW PUSHES THROUGH THE MOUNTAINS AND INTO THE COASTAL PLAIN
OF THE CAROLINAS TONIGHT...NELY FLOW WILL BRING CLOUDS AND
LINGERING SHOWERS TO THE REGION OVERNIGHT. AS THE LOW SITS AND
SPINS TO OUR SOUTHEAST ON FRIDAY...WE WILL STAY IN A COOL NELY
FLOW WITH WRAP AROUND MOISTURE BEING PULLED INTO THE AREA. THIS
WILL BE ENOUGH TO GENERATE SCATTERED SHOWERS AND IF WE CAN MANAGE
ENOUGH SUN TO CREATE SOME SURFACE BASED INSTABILITY...SOME THUNDER
CAN MATERIALIZE AS WELL.
TEMPERATURES TONIGHT WILL GENERALLY BE IN THE UPPER 60S/AROUND 70 EAST
OF THE RIDGE TO THE LOW/MID 60S WEST. HIGHS ON FRIDAY WILL BE
SUPPRESSED A BIT WITH CLOUDS AND A COOL NELY FLOW SO READINGS OF
MID/UPPER 70S EAST TO UPPER 60S/LOWER 70S WEST SHOULD DO IT.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
AS OF 330 PM EDT FRIDAY...
SURFACE LOW PRESSURE OVER THE CAROLINAS WILL DEEPEN AND MOVE
NORTHEAST THROUGH SUNDAY MORNING AIDED BY ANOTHER SHORT WAVE
TRACKING DOWN THE WESTERN SIDE OF THE UPPER TROF.
MODELS HOLD MOISTURE IN THE REGION THROUGH THE WEEKEND. BEST AREAL
COVERAGE OF PRECIPITATION WILL BE MOVING EAST OUT OF THE FORECAST
AREA WITH THE LOW ON FRIDAY NIGHT...BUT ENOUGH INSTABILITY OF
MOISTURE IN THE FAR WESTERN COUNTY WARNING AREA SATURDAY AFTERNOON
AND SUNDAY AFTERNOON FOR ISOLATED SHOWERS AND THUNDERSTORMS.
HOWEVER...ON FRIDAY NIGHT AND SATURDAY EAST TO NORTHEAST WINDS FROM
THE SURFACE THROUGH AROUND 700 MB MAY KEEP ENOUGH MOISTURE AND LIFT
EAST OF THE BLUE RIDGE FOR LOW CLOUDS ALONG WITH SPOTTY LIGHT RAIN
AND DRIZZLE.
BY SUNDAY LOW WILL BE FAR ENOUGH OFF THE COAST FOR LIGHTER NORTHEAST
WINDS IN THE EASTERN COUNTY WARNING AREA. HIGH PRESSURE/IN-SITU TYPE
WEDGE WILL BE OVER SOUTHWEST VIRGINIA...IN BETWEEN THE LOW OFFSHORE
AND AN INVERTED TROF OVER THE OHIO AND TENNESSEE VALLEYS.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 330 PM EDT FRIDAY...
HIGH AMPLITUDE 500 MB WILL DEVELOP THIS TIME FRAME WITH A CLOSED LOW
OVER THE PACIFIC NW...A LARGE RIDGE CENTERED ALONG THE ROCKIES AND A
DEEP TROF/CLOSED LOW OVER THE EASTERN THIRD OF THE COUNTRY.
THE MAIN TROF AXIS WAS SLIGHTLY SLOWER ON THE 00Z SUITE OF GUIDANCE
BUT STILL EXPECTING THE SURFACE FRONT TO CROSS THROUGH THE MID
ATLANTIC REGION ON TUESDAY. LOW DEEPENS AND MOVES NORTHEAST ALONG
THE COAST TUESDAY THROUGH WEDNESDAY. 00Z ECMWF WAS ADVERTISING A
RELATIVELY COOLER AIR MASS BEHIND THE FRONT. BEHIND THIS
SYSTEM...LOW LEVEL MOISTURE REMAINS OVER THE AREA...ESPECIALLY IN THE
MOUNTAINS THROUGH WEDNESDAY. BEST PROBABILITY OF PRECIPITATION WILL
BE AHEAD OF THE FRONT ON MONDAY AND ALONG THE FRONT ON TUESDAY. THEN
AIR MASS DRIES OUT. PRECIPITABLE WATER VALUES DROP BELOW AN INCH.
HAVE DRY FORECAST FOR MUCH OF THE COUNTY WARNING AREA ON WEDNESDAY
AND THURSDAY.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
AS OF 220 PM EDT THURSDAY...
A LOT OF VARIABILITY IN THE AVIATION FORECAST THIS TAF PERIOD.
FRONTAL BOUNDARY IS CURRENTLY DRAPED E/W JUST SOUTH OF TAF SITES
WHICH IS KEEPING THE MOST UNSTABLE AIR JUST OFF TO THE SOUTH...
AND LATEST RADAR LOOPS SHOW THAT DEEP CONVECTION HAS STARTED TO
FIRE IN THE BETTER INSTABILITY JUST TO THE SOUTH. HOWEVER...THERE
IS STILL A LOT OF DYNAMIC ENERGY YET TO PASS THROUGH THE REGION AS
A VIGOROUS UPPER LEVEL SHORT WAVE DRIVES A SURFACE LOW ALONG THE
FRONT TONIGHT. BELIEVE CONVECTION WITH LOCALLY HEAVY RAIN WILL
FILL IN WITH TIME WITH SUBSTANTIAL AREAL COVERAGE...WITH THE BULK
OF ACTIVITY MOVING THROUGH ROUGHLY 22Z-04Z. UNTIL THEN EXPECTING
MAINLY VFR WITH VCSH/VCTS...THEN LINGERING -SHRA THEREAFTER.
TONIGHT AS THE SURFACE LOW DIVES THROUGH THE MOUNTAINS OF VA/NC
AND INTO THE COASTAL PLAIN OF THE CAROLINAS...TAF SITES WILL
REMAIN ON THE COLD SIDE OF THE SYSTEM IN ELY/NELY FLOW. THIS WILL
ALLOW LOW IFR/LIFR CIGS TO BECOME ESTABLISHED BY AROUND MIDNIGHT
AND PERSIST THROUGH DAYBREAK FRIDAY. THE CIGS MAY START TO LIFT
TOWARD THE END OF THE TAF PERIOD BUT DO NOT HAVE ENOUGH CONFIDENCE
IN TIMING OF ANY IMPROVEMENT TO INCLUDE IN THE FORECAST. GUIDANCE
ALSO INDICATES THE POTENTIAL FOR IFR FOG DEVELOPMENT...BUT BELIEVE
THIS IS OVERDONE AND WILL HOLD VSBYS MVFR AT ALL SITES EXCEPT KLWB
AND KBLF WHERE THEY LOOK TO DIP JUST INTO IFR. THIS WILL HAVE TO
BE REEVALUATED IN LATER PACKAGES BASED ON WHERE AND EXACTLY HOW
MUCH RAIN FALLS THIS EVENING/EARLY TONIGHT.
AS PREVIOUSLY MENTIONED WINDS WILL BECOME E/NE TONIGHT AND REMAIN
RELATIVELY LIGHT THROUGH THE PERIOD...THOUGH GUSTY CONDITIONS AND
VARIABLE DIRECTIONS CAN BE EXPECTED IN TSRA ESPECIALLY NEAR KDAN
SINCE THEY ARE CLOSER TO THE MORE UNSTABLE AIR TO THE SOUTH.
EXTENDED AVIATION FORECAST...
OVER THE WEEKEND...VFR CONDITIONS RETURN TO MOST LOCATIONS AS HIGH
PRESSURE BUILDS INTO AND OVER THE REGION. LATE NIGHT AND EARLY
MORNING MOUNTAIN AND RIVER VALLEY FOG IS POSSIBLE.
MONDAY WILL BRING OUR NEXT CHANCE OF ISOLATED TO SCATTERED SHOWERS
AND STORMS TO THE AREA WITH A PASSING SHORTWAVE TROUGH. MOST AREAS
WILL BE VFR. LOCALIZED...BRIEF MVFR/IFR CONDITIONS WILL BE
POSSIBLE UNDER THE HEAVIER CORES OF ANY CONVECTION THAT DEVELOPS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...MBS
NEAR TERM...MBS/WP
SHORT TERM...AMS
LONG TERM...AMS
AVIATION...MBS/PM
AREA FORECAST DISCUSSION...UPDATE FOR AVIATION
NWS LITTLE ROCK AR
1240 AM CDT FRI AUG 2015
.AVIATION...
FORECAST WILL START WITH VFR CONDITIONS WITH SCATTERED CEILINGS.
WINDS WILL BE LIGHT AND VARIABLE TO A SE TO SW WIND AT 3 TO 8 MPH.
OVERNIGHT ISOLATED CONVECTION MAY DEVELOP OVER NORTHERN AR TO PARTS
OF CENTRAL AR AROUND SUNRISE FRIDAY...BUT DUE TO UNCERTAINTY IN
LOCATION AND COVERAGE...ONLY USED VCTS. VFR CEILINGS WILL BE SEEN
WITH CONVECTION. ON FRIDAY...ISOLATED CONVECTION WILL BE POSSIBLE
MAINLY OVER NE TO EAST AR AND ONLY USED VCTS DUE TO UNCERTAINTY.
WINDS ON FRIDAY WILL BE SE TO SW AT 5 TO 15 MPH...WHILE BECOMING
MORE W TO NW OVER NORTHERN AR DURING THE DAY. (59)
&&
.PREV DISCUSSION... /ISSUED 258 PM CDT THU AUG 6 2015/
.SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT
HOT AND HUMID CONDITIONS HAVE CONTINUED AROUND THE NATURAL STATE
TODAY WITH SHOWERS AND THUNDERSTORMS DEVELOPING ACROSS PORTIONS OF
CENTRAL ARKANSAS DURING THE DAY TODAY AND CONTINUING TO PUSH TO THE
SOUTHEAST THROUGH THE AFTERNOON. THERE ARE SOME SLIGHT CHANCES THAT
ADDITIONAL SHOWERS AND THUNDERSTORMS COULD DEVELOP THIS
AFTERNOON...GENERALLY SOUTH OF THE INTERSTATE 40 CORRIDOR. HRRR AND
WRF...HAVE CONTINUALLY SHOWED CHANCES FOR DEVELOPMENT THIS
AFTERNOON...BUT BASED ON CURRENT SATELLITE TRENDS...COULD NOT
JUSTIFY MORE THAN SLIGHT CHANCE POPS.
TONIGHT...EXPECT SHOWERS AND THUNDERSTORMS TO ONCE AGAIN DEVELOP
ACROSS NORTHWEST ARKANSAS IN RESPONSE TO AN UPPER LEVEL SHORTWAVE
THAT WILL PUSH SOUTHEAST...WITH BEST CHANCES NORTH OF THE INTERSTATE
40 WEST OF LITTLE ROCK TO NORTH OF INTERSTATE 530. THIS WILL ONCE
AGAIN KEEP TEMPERATURES SOMEWHAT LIMITED ACROSS NORTHERN ARKANSAS
AGAIN ON FRIDAY. HOWEVER...TEMPERATURES WILL WARM ALONG THE ARKANSAS
RIVER VALLEY AND TO THE SOUTHWEST ON FRIDAY WITH HEAT INDICES LIKELY
TOPPING 110 DEGREES. AS A RESULT...HAVE GONE AND ISSUED AN EXCESSIVE
HEAT WARNING ALONG THE ARKANSAS RIVER VALLEY.
UPPER LEVEL RIDGE WILL BUILD INTO THE REGION FOR THE WEEKEND AND
BRING EVEN HOTTER TEMPERATURES TO THE NATURAL STATE...WITH NO
PRECIPITATION EXPECTED. AT THIS POINT...FELT CONFIDENT IN EXTENDING
THE HEAT ADVISORY THROUGH SATURDAY...HOWEVER DID NOT EXTEND THE
EXCESSIVE HEAT WARNING. WILL LET FUTURE SHIFTS MONITOR THE THREAT.
&&
.LONG TERM...MONDAY THROUGH THURSDAY
UPPER AIR PATTERNS ACROSS NORTH AMERICA ARE EXPECTED TO UNDERGO
SUBTANTIAL AMPLIFICATION EARLY IN THIS PERIOD. A COLD FRONT WILL
MOVE SOUTH THROUGH THE MID SOUTH EARLY IN THIS PERIOD. AT THIS
TIME...PRECIPITATION AMOUNT SHOULD BE LIGHT. MAIN EFFECT OF THIS
FEATURE WILL BE TO BRING AN AIR MASS WITH NEAR NORMAL TEMPERATURES.
&&
.LZK WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY FROM NOON TO 7 PM CDT SATURDAY FOR BAXTER-BOONE-
INDEPENDENCE-JACKSON-MARION-NEWTON-SEARCY-STONE.
EXCESSIVE HEAT WARNING FROM NOON TO 7 PM CDT FRIDAY FOR BRADLEY-
CALHOUN-CLARK-CLEVELAND-CONWAY-DALLAS-DESHA-DREW-FAULKNER-
GARLAND-GRANT-HOT SPRING-JEFFERSON-JOHNSON-LINCOLN-LOGAN-LONOKE-
OUACHITA-PERRY-POPE-PULASKI-SALINE-YELL.
HEAT ADVISORY FROM NOON FRIDAY TO 7 PM CDT SATURDAY FOR ARKANSAS-
CLEBURNE-CONWAY-DESHA-FAULKNER-JEFFERSON-JOHNSON-LINCOLN-LOGAN-
LONOKE-MONROE-PERRY-POPE-PRAIRIE-PULASKI-SALINE-VAN BUREN-WHITE-
WOODRUFF-YELL.
HEAT ADVISORY UNTIL 7 PM CDT SATURDAY FOR BRADLEY-CALHOUN-CLARK-
CLEVELAND-DALLAS-DREW-GARLAND-GRANT-HOT SPRING-MONTGOMERY-
OUACHITA-PIKE-POLK-SCOTT.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS MELBOURNE FL
445 AM EDT FRI AUG 7 2015
.DISCUSSION...
TODAY...
A MID LEVEL SHORTWAVE TROUGH WILL PASS BY TO OUR NORTH AND INDUCE
SFC LOW DEVELOPMENT ALONG THE CAROLINA COAST. HIGHER MOISTURE
COMBINED WITH SOME MID LEVEL ENERGY WILL GENERATE SCATTERED TO
NUMEROUS STORMS ACROSS N FL. THE DEVELOPING NW FLOW ALOFT SHOULD
STEER SOME OF THESE STORMS AND THEIR OUTFLOWS INTO OUR NORTHERN
SECTIONS THIS AFTN. SO HAVE DRAWN HIGHER POPS (50 PERCENT) ACROSS
THE NORTH AND 20 PERCENT ACROSS THE FAR SOUTH. AT THE SFC...A BREEZY
W/SW FLOW IS EXPECTED WHICH WILL INHIBIT FORMATION OF THE EAST COAST
SEA BREEZE AND PRODUCE ABOVE NORMAL TEMPERATURES ESP AT THE COAST.
RECORD HIGHS APPEAR A BIT OUT OF REACH BUT WIDESPREAD MID 90S
EXPECTED.
TEMPS ALOFT ARE NOT VERY COOL (-6 TO -7C AT 500MB) BUT HOT SFC
TEMPS WILL HELP GROW INSTABILITY. AND LINGERING DRY AIR ALOFT
WILL COMBINE WITH THE STRONGER WIND FIELDS TO PRODUCE A RISK OF
STRONG WIND GUSTS WITH THE STORMS.
SAT-SUN...
WX PATTERN OVER THE ERN CONUS WILL BCM HIGHLY AMPLIFIED AS A 60-80KT
JET OVER W OF THE MS RIVER DIGS INTO THE MIDWEST AND COMBINES WITH A
DEPARTING 80-100KT JET S OF THE CANADIAN MARITIMES TO SPIN UP A
BROAD AREA OF LOW PRES OVER THE MID ATLC. WHILE THE RELATIVELY LOW
JET SPEEDS DO NOT IMPLY SIGNIFICANT DEEPENING AS THE LOW MOVES
INTO THE W ATLC...POST FRONTAL NWRLY FLOW WILL BE PROVIDED BY A
MID LVL ANTICYCLONE OVER THE TX PLAINS. COMBINED...THERE SHOULD BE
SUFFICIENT "PUSH AND PULL" TO CRANK A WEAK FRONTAL BOUNDARY FROM
THE MID SOUTH INTO N FL ON SAT...THEN INTO CENTRAL FL ON SUN.
OUTSIDE OF THE IMMEDIATE FRONTAL TROF...LATEST RAP ANALYSIS SHOWS
DEEP LYR MOISTURE OVER THE GOMEX/DEEP SOUTH IS SOMEWHAT
LACKING...ESP IN THE H100-H70 LYR. INDEED...WHILE MODEL SOUNDINGS
ARE INDICATING PREFRONTAL PWAT VALUES ON SAT BTWN 1.8"-2.0"...MUCH
OF THIS IS TRAPPED ABV THE H50 LVL. POST FRONTAL PWAT VALUES ON
SUN DROP TO 1.7"-1.8"...AGAIN MOSTLY ABV H50 WITH A NOTEWORTHY
AMOUNT OF DRY AIR IN THE H85-H50 LYR.
STRONG/SVR WX THREAT APPEARS MINIMAL FOR THE UPCOMING WEEKEND AS THE
APPROACHING FRONT PULLS A MID LVL THERMAL RIDGE FROM THE DEEP SOUTH
INTO THE FL PENINSULA. H70 TEMPS ARND 10C AND H50 TEMPS BTWN
-4/-5C...YIELDING AVG LAPSE RATES BTWN 5-6C/KM THRU THE LYR. MID LVL
DYNAMIC SUPPORT ON SAT WILL BE ENHANCED BY A TIGHT BAND OF VORTICITY
AS THE FRONT SAGS THROUGH N FL...THOUGH UPR LVL WINDS AOB 20KTS WILL
NOT GENERATE MUCH DIVERGENCE. VORTICITY DIMINISHES ON SUN AS THE
TROF AXIS WORKS ITS WAY INTO STATE...BUT UPR LVL DIVERGENCE SHOULD
INCREASE AS THE AMPLIFYING WX PATTERN ALLOWS 40-50KT WINDS TO WORK
THEIR WAY ACRS THE FL PENINSULA.
HIGHEST PRECIP CHANCES ON SAT AHEAD OF THE FRONT...60PCT OVER MOST
OF THE CWA...50PCT ARND LAKE OKEECHOBEE AS THE FRONT IS EXPECTED TO
STALL IN THE VICINITY OF THE I-4 CORRIDOR. PRECIP CHANCES DIMINISH
TO 40PCT AREAWIDE ON SUN DUE TO DRIER MID LVL AIR AND DIMINISHED MID
LVL DYNAMIC SUPPORT. PREVAILING WRLY FLOW ON SAT WILL PUSH MAX TEMPS
INTO THE L/M90S. SEA BREEZE FORMATION ON SUN WILL KEEP COASTAL
TEMPS IN THE U80S. MIN TEMPS IN THE L/M70S THRU THE WEEKEND.
MON-THU...
BOTH GFS/ECMWF MODELS INDICATE A STRONG MID LVL RIDGING PATTERN
PREVAILING OVER THE NATION`S MID SECTION INTO THE MIDDLE OF NEXT
WEEK. THIS WILL PROMOTE A PERSISTENT TROFFING PATTERN OVER THE ERN
CONUS WHICH IN TURN WILL PREVENT THE ATLC RIDGE AXIS FROM REBUILDING
ACRS THE FL PENINSULA. THE RESULTING WRLY STEERING FLOW WILL FAVOR
THE ERN FL PENINSULA FOR DAILY PRECIP.
NOTHING STANDING OUT THAT WOULD INDICATE HIGH PRECIP COVERAGE
ATTM...WILL KEEP POPS AOB 50PCT FOR NOW AS THE WEAKER FLOW REGIME
WILL ALLOW THE EAST COAST SEA BREEZE TO DVLP...WHILE THE RELATIVELY
LOW PRES OVER THE ERN SEABOARD WILL ALLOW SUFFICIENT MOISTURE TO
POOL ACRS THE REGION. TEMPERATURES CLOSE TO CLIMO WITH AFTN MAXES IN
THE U80S/L90S...MRNG MINS IN THE L/M70S.
&&
.AVIATION...
A STRONGER WESTERLY FLOW EXPECTED TODAY SO WILL NOT INDICATE A SEA
BREEZE AT COASTAL TERMINALS. SOME GUSTS NEAR 20 KNOTS CAN BE
EXPECTED DURING THE MID DAY NEAR PEAK HEATING. BEST CHANCE FOR
STORMS WILL BE OVER NORTHERN TERMINALS AND WILL PROBABLY ADD A
TEMPO GROUP FOR LEE/DAB IN THE NEXT TAF ISSUANCE...ROUGHLY 20Z-
22Z. WILL HOLD ONTO VCTS AT OTHER TERMINALS FOR NOW. FASTER CELL
MOTION WILL PROMOTE A RISK OF STRONG CONVECTIVE WIND GUSTS IN AND
NEAR STORMS.
&&
.MARINE...
TODAY...LOW LEVEL RIDGE AXIS HAS DROPPED BACK ACROSS SOUTH FL SO
THERE WILL BE A STRONGER OFFSHORE (W/SW) FLOW WITH WIND SPEEDS UP
TO 15 KNOTS. IN ADDITION TO PRODUCING SOME CHOPPY SEAS OVER THE
OPEN ATLC...THE FASTER STORM MOTION WILL PRODUCE A THREAT FOR
STRONG WIND GUSTS AS THEY CROSS THE INTRACOASTAL AND ONTO THE
NEARSHORE ATLC. BOATERS SHOULD BE PREPARED FOR A COUPLE/FEW
SPECIAL MARINE WARNINGS THIS AFTN.
TONIGHT...EXPECT A CAUTION HEADLINE FOR THE OFFSHORE VOLUSIA AND
BREVARD WATERS FOR 15-20 KNOTS AS LOW PRESSURE PUSHES OFF THE
CAROLINA COAST AND PRES GRAD TIGHTENS.
SAT-SAT NIGHT...GENTLE TO MODERATE W/SW BREEZE WILL PREVAIL AS A
BROAD LOW PRES SYSTEM OVER THE MID ATLC CRANKS A FRONTAL BOUNDARY
INTO N FL. THE WRLY COMPONENT WILL GENERATE SHORT PD WIND CHOP
INCREASING SEAWARD... 1-2FT NEARSHORE AND 2-3FT OFFSHORE...UP TO 4FT
IN THE GULF STREAM. SCT/NMRS OFFSHORE MOVING SHRAS AND TSTMS.
SUN-SUN NIGHT...LCL PGRAD WILL SLACKEN AS THE FRONTAL BNDRY SAGS
INTO CENTRAL FL. LIGHT TO GENTLE WRLY BREEZE BCMG S/SE NEAR THE
COAST IN THE AFTN WITH THE FORMATION OF THE EAST COAST SEA BREEZE...
THEN A LIGHT SRLY BREEZE OVERNIGHT AS THE FRONT WASHES OUT OVER S
FL. SEAS AOB 2FT NEARSHORE AND 2-3FT OFFSHORE. SCT SHRAS/ISOLD TSRAS
MOVING ONSHORE.
MON-MON NIGHT...WEAK PGRAD WILL PERSIST IN THE WAKE OF THE
DISSIPATED FRONT. LIGHT ERLY BREEZE THRU THE DAY...BCMG A LIGHT
TO GENTLE S/SE BREEZE OVERNIGHT AS A NEW STORM SYSTEM PULLS
ANOTHER FRONTAL BOUNDARY INTO THE DEEP SOUTH. SEAS AOB 2FT
NEARSHORE AND 2-3FT OFFSHORE.
TUE-TUE NIGHT...LIGHT TO GENTLE S/SERLY BREEZE THRU THE DAY BCMG A
GENTLE TO MODERATE S/SWRLY BREEZE OVERNIGHT AS THE FRONTAL TROF SAGS
INTO N FL AND STALLS. LIMITED FETCH WILL KEEP NEARSHORE SEAS AOB
2FT...OFFSHORE SEAS 2-3FT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 91 76 89 75 / 50 30 60 20
MCO 92 76 92 76 / 30 20 60 20
MLB 94 75 92 76 / 30 20 60 20
VRB 94 75 92 74 / 30 20 60 20
LEE 90 77 91 77 / 40 30 60 20
SFB 92 77 91 76 / 40 20 60 20
ORL 92 78 92 77 / 30 20 60 20
FPR 94 73 92 75 / 30 20 50 20
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM...KELLY
LONG TERM....BRAGAW
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
433 AM EDT FRI AUG 7 2015
.DISCUSSION...
TODAY...A MID LEVEL SHORTWAVE TROUGH WILL PASS BY TO OUR NORTH
AND INDUCE SFC LOW DEVELOPMENT ALONG THE CAROLINA COAST. HIGHER
MOISTURE COMBINED WITH SOME MID LEVEL ENERGY WILL GENERATE
SCATTERED TO NUMEROUS STORMS ACROSS N FL. THE DEVELOPING NW FLOW
ALOFT SHOULD STEER SOME OF THESE STORMS AND THEIR OUTFLOWS INTO
OUR NORTHERN SECTIONS THIS AFTN. SO HAVE DRAWN HIGHER POPS (50
PERCENT) ACROSS THE NORTH AND 20 PERCENT ACROSS THE FAR SOUTH. AT
THE SFC...A BREEZY W/SW FLOW IS EXPECTED WHICH WILL INHIBIT
FORMATION OF THE EAST COAST SEA BREEZE AND PRODUCE ABOVE NORMAL
TEMPERATURES ESP AT THE COAST. RECORD HIGHS APPEAR A BIT OUT OF
REACH BUT WIDESPREAD MID 90S EXPECTED.
TEMPS ALOFT ARE NOT VERY COOL (-6 TO -7C AT 500MB) BUT HOT SFC
TEMPS WILL HELP GROW INSTABILITY. AND LINGERING DRY AIR ALOFT
WILL COMBINE WITH THE STRONGER WIND FIELDS TO PRODUCE A RISK OF
STRONG WIND GUSTS WITH THE STORMS.
SAT-SUN...
WX PATTERN OVER THE ERN CONUS WILL BCM HIGHLY AMPLIFIED AS A 60-80KT
JET OVER W OF THE MS RIVER DIGS INTO THE MIDWEST AND COMBINES WITH A
DEPARTING 80-100KT JET S OF THE CANADIAN MARITIMES TO SPIN UP A
BROAD AREA OF LOW PRES OVER THE MID ATLC. WHILE THE RELATIVELY LOW
JET SPEEDS DO NOT IMPLY SIGNIFICANT DEEPENING AS THE LOW MOVES
INTO THE W ATLC...POST FRONTAL NWRLY FLOW WILL BE PROVIDED BY A
MID LVL ANTICYCLONE OVER THE TX PLAINS. COMBINED...THERE SHOULD BE
SUFFICIENT "PUSH AND PULL" TO CRANK A WEAK FRONTAL BOUNDARY FROM
THE MID SOUTH INTO N FL ON SAT...THEN INTO CENTRAL FL ON SUN.
OUTSIDE OF THE IMMEDIATE FRONTAL TROF...LATEST RAP ANALYSIS SHOWS
DEEP LYR MOISTURE OVER THE GOMEX/DEEP SOUTH IS SOMEWHAT
LACKING...ESP IN THE H100-H70 LYR. INDEED...WHILE MODEL SOUNDINGS
ARE INDICATING PREFRONTAL PWAT VALUES ON SAT BTWN 1.8"-2.0"...MUCH
OF THIS IS TRAPPED ABV THE H50 LVL. POST FRONTAL PWAT VALUES ON
SUN DROP TO 1.7"-1.8"...AGAIN MOSTLY ABV H50 WITH A NOTEWORTHY
AMOUNT OF DRY AIR IN THE H85-H50 LYR.
STRONG/SVR WX THREAT APPEARS MINIMAL FOR THE UPCOMING WEEKEND AS THE
APPROACHING FRONT PULLS A MID LVL THERMAL RIDGE FROM THE DEEP SOUTH
INTO THE FL PENINSULA. H70 TEMPS ARND 10C AND H50 TEMPS BTWN
-4/-5C...YIELDING AVG LAPSE RATES BTWN 5-6C/KM THRU THE LYR. MID LVL
DYNAMIC SUPPORT ON SAT WILL BE ENHANCED BY A TIGHT BAND OF VORTICITY
AS THE FRONT SAGS THROUGH N FL...THOUGH UPR LVL WINDS AOB 20KTS WILL
NOT GENERATE MUCH DIVERGENCE. VORTICITY DIMINISHES ON SUN AS THE
TROF AXIS WORKS ITS WAY INTO STATE...BUT UPR LVL DIVERGENCE SHOULD
INCREASE AS THE AMPLIFYING WX PATTERN ALLOWS 40-50KT WINDS TO WORK
THEIR WAY ACRS THE FL PENINSULA.
HIGHEST PRECIP CHANCES ON SAT AHEAD OF THE FRONT...60PCT OVER MOST
OF THE CWA...50PCT ARND LAKE OKEECHOBEE AS THE FRONT IS EXPECTED TO
STALL IN THE VICINITY OF THE I-4 CORRIDOR. PRECIP CHANCES DIMINISH
TO 40PCT AREAWIDE ON SUN DUE TO DRIER MID LVL AIR AND DIMINISHED MID
LVL DYNAMIC SUPPORT. PREVAILING WRLY FLOW ON SAT WILL PUSH MAX TEMPS
INTO THE L/M90S. SEA BREEZE FORMATION ON SUN WILL KEEP COASTAL
TEMPS IN THE U80S. MIN TEMPS IN THE L/M70S THRU THE WEEKEND.
MON-THU...UPDATE TO FOLLOW.
&&
.AVIATION...
A STRONGER WESTERLY FLOW EXPECTED TODAY SO WILL NOT INDICATE A SEA
BREEZE AT COASTAL TERMINALS. SOME GUSTS NEAR 20 KNOTS CAN BE
EXPECTED DURING THE MID DAY NEAR PEAK HEATING. BEST CHANCE FOR
STORMS WILL BE OVER NORTHERN TERMINALS AND WILL PROBABLY ADD A
TEMPO GROUP FOR LEE/DAB IN THE NEXT TAF ISSUANCE...ROUGHLY 20Z-
22Z. WILL HOLD ONTO VCTS AT OTHER TERMINALS FOR NOW. FASTER CELL
MOTION WILL PROMOTE A RISK OF STRONG CONVECTIVE WIND GUSTS IN AND
NEAR STORMS.
&&
.MARINE...
TODAY...LOW LEVEL RIDGE AXIS HAS DROPPED BACK ACROSS SOUTH FL SO
THERE WILL BE A STRONGER OFFSHORE (W/SW) FLOW WITH WIND SPEEDS UP
TO 15 KNOTS. IN ADDITION TO PRODUCING SOME CHOPPY SEAS OVER THE
OPEN ATLC...THE FASTER STORM MOTION WILL PRODUCE A THREAT FOR
STRONG WIND GUSTS AS THEY CROSS THE INTRACOASTAL AND ONTO THE
NEARSHORE ATLC. BOATERS SHOULD BE PREPARED FOR A COUPLE/FEW
SPECIAL MARINE WARNINGS THIS AFTN.
TONIGHT...EXPECT A CAUTION HEADLINE FOR THE OFFSHORE VOLUSIA AND
BREVARD WATERS FOR 15-20 KNOTS AS LOW PRESSURE PUSHES OFF THE
CAROLINA COAST AND PRES GRAD TIGHTENS.
SAT-SAT NIGHT...GENTLE TO MODERATE W/SW BREEZE WILL PREVAIL AS A
BROAD LOW PRES SYSTEM OVER THE MID ATLC CRANKS A FRONTAL BOUNDARY
INTO N FL. THE WRLY COMPONENT WILL GENERATE SHORT PD WIND CHOP
INCREASING SEAWARD... 1-2FT NEARSHORE AND 2-3FT OFFSHORE...UP TO 4FT
IN THE GULF STREAM. SCT/NMRS OFFSHORE MOVING SHRAS AND TSTMS.
SUN-SUN NIGHT...LCL PGRAD WILL SLACKEN AS THE FRONTAL BNDRY SAGS
INTO CENTRAL FL. LIGHT TO GENTLE WRLY BREEZE BCMG S/SE NEAR THE
COAST IN THE AFTN WITH THE FORMATION OF THE EAST COAST SEA BREEZE...
THEN A LIGHT SRLY BREEZE OVERNIGHT AS THE FRONT WASHES OUT OVER S
FL. SEAS AOB 2FT NEARSHORE AND 2-3FT OFFSHORE. SCT SHRAS/ISOLD TSRAS
MOVING ONSHORE.
MON-MON NIGHT...WEAK PGRAD WILL PERSIST IN THE WAKE OF THE
DISSIPATED FRONT. LIGHT ERLY BREEZE THRU THE DAY...BCMG A LIGHT
TO GENTLE S/SE BREEZE OVERNIGHT AS A NEW STORM SYSTEM PULLS
ANOTHER FRONTAL BOUNDARY INTO THE DEEP SOUTH. SEAS AOB 2FT
NEARSHORE AND 2-3FT OFFSHORE.
TUE-TUE NIGHT...LIGHT TO GENTLE S/SERLY BREEZE THRU THE DAY BCMG A
GENTLE TO MODERATE S/SWRLY BREEZE OVERNIGHT AS THE FRONTAL TROF SAGS
INTO N FL AND STALLS. LIMITED FETCH WILL KEEP NEARSHORE SEAS AOB
2FT...OFFSHORE SEAS 2-3FT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 91 76 89 75 / 50 30 60 20
MCO 92 76 92 76 / 30 20 60 20
MLB 94 75 92 76 / 30 20 60 20
VRB 94 75 92 74 / 30 20 60 20
LEE 90 77 91 77 / 40 30 60 20
SFB 92 77 91 76 / 40 20 60 20
ORL 92 78 92 77 / 30 20 60 20
FPR 94 73 92 75 / 30 20 50 20
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM...KELLY
LONG TERM....BRAGAW
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
413 AM CDT FRI AUG 7 2015
.SHORT TERM...
349 AM CDT
THROUGH SUNDAY...
CONCERNS REVOLVE AROUND PRECIPITATION CHANCES EACH OF THE NEXT FEW
DAYS.
A COMPACT BUT POTENT UPPER LEVEL DISTURBANCE IN MN IS PRODUCING A
COMPLEX OF THUNDERSTORMS NOW MOVING INTO WESTERN WISCONSIN. THERE IS
A WEAK SURFACE REFLECTION WITH THIS FEATURE WHERE THE MORE ORGANIZED
ACTIVITY IS ONGOING. CLOSER TO HOME...SURFACE HIGH PRESSURE IS
HOLDING FIRM JUST NEAR LAKE HURON...WITH THE RIDGE AXIS ORIENTED
SOUTHWESTWARD. IR IMAGERY EARLY THIS MORNING HAS SHOWN A CONTINUAL
EROSION OF THE DEEPER CLOUDS ON THE SOUTHERN END OF THIS COMPLEX AS
IT MOVES INTO DRIER AIR FARTHER SOUTH AND EAST.
AN UPPER LEVEL JET MOVING INTO THE NORTHERN PLAINS WILL ALLOW THIS
UPPER DISTURBANCE TO MOVE SOUTH AND EAST TOWARD THE AREA
TODAY...EVEN OUTRUNNING THE SURFACE LOW. MUCH OF THE NEAR TERM
GUIDANCE KEEPS ERODING PRECIP SOUTH OF THE WISCONSIN BORDER AHEAD OF
THIS SYSTEM. THE EXCEPTION TO THIS THE EXPERIMENTAL HRRR AND
SEVERAL HOP-WRF MEMBERS WHICH ARE A BIT MORE AGGRESSIVE WITH
DRIVING PRECIP THROUGH THE AREA...ESPEICALLY THIS AFTERNOON.
OBSERVATIONS SUGGEST SOME CONTINUED DEVELOPMENT SOUTHWARD THROUGH
THE MORNING INTO THE INSTABILITY AXIS WHICH WILL GRADUALLY
APPROACH FROM THE WEST TODAY. HAVE STILL KEPT POPS ON THE LOWER
SIDE AWAY FROM NORTH CENTRAL ILLINOIS AND POINTS WEST...THOUGH
EXPECT OUR NORTHWESTERN ZONES INTO WINNEBAGO/BOONE/MCHENRY
COUNTIES STAND A CHANCE OF SOME SHOWERS OR A STRAY STORM LATER
THIS MORNING INTO THE AFTERNOON. CONTINUED DRY AIR SHOULD FURTHER
ERODE AT THE PRECIP...THOUGH AS THE DAY GOES ON AND THE
INSTABILITY AXIS SHIFTS EASTWARD WITH THE UPPER LOW...EXPECT THAT
SOME SHOWERS WILL BE POSSIBLE. SOUNDINGS ARE NOT THRILLED ABOUT
THE THUNDER POTENTIAL CLOSER TO CHICAGO WITH CAPPING HOLDING.
TONIGHT...THE UPPER LOW SHIFTS EAST AND OUTPACES THE SURFACE LOW AND
THUS EXPECT SOME DECREASE IN COVERAGE OF SHOWERS AND COULD JUST BE
DRY...THOUGH WILL HANG ONTO A LOW POP MENTION OVERNIGHT FOR SOME
LINGERING LOW LEVEL CONVERGENCE.
SATURDAY...FOCUS SHIFTS TO ENERGY PROPAGATING FROM THE TROUGH OFF
THE CA COAST THIS MORNING. THIS IS FORECAST TO RIDE A DECENT UPPER
JET THROUGH THE PLAINS OVERNIGHT INTO THE MORNING AND ALONG THE
NORTHERN FRINGES OF THE UPPER LEVEL RIDGE AXIS THAT EXTENDS FROM
TEXAS NORTH INTO THE CENTRAL PLAINS. THIS WAVE CRUISES THROUGH
SATURDAY MORNING WITH SURFACE HIGH PRESSURE IN PLACE AND A LACK OF
DEEPER MOISTURE...SO HAVE CONTINUED A DRY FORECAST...AND THAT GOES
FOR SATURDAY AFTERNOON AS WELL AS THE WAVE MOVES EAST. WILL HAVE
TO WATCH THE MORNING PERIOD IF THE LOWER LEVELS MOISTEN UP A BIT
MORE THAN FORECAST THAT A STRAY SHOWER OR STORM WOULD BE POSSIBLE.
THE NAM IS A LITTLE SLOWER WITH THIS WAVE...BUT STILL DRY IN THE
AFTERNOON AS THE STRONGER FORCING REMAINS TO OUR WEST.
CHANCES FOR SHOWERS AND STORMS INCREASE SATURDAY NIGHT INTO SUNDAY
MORNING AS WE GET A BETTER CO-LOCATION OF DEEPER MOISTURE TRANSPORT
COURTESY OF A DECENT LOW LEVEL JET...ANOTHER PACIFIC
DISTURBANCE...AND PWATS APPROACHING 2 INCHES. WE HANG ONTO SE FLOW
AT THE SURFACE FARTHER EAST...WHICH WOULD THEN GIVE THE HIGHER
CONCERN FOR MODERATE TO HEAVY PRECIP RATES SOUTH AND WEST. THERE
IS A SEVERE THREAT GIVEN THE MODEST WESTERLY FLOW NORTH OF THE
RIDGE AND HIGHER DEWPOINTS ADVECTING IN...BUT DESTABILIZATION
CONCERNS EXIST AT THIS POINT IN TIME TO NAIL DOWN THE SPECIFICS
YET. THE MARGINAL RISK IS FOCUSED IN OUR SOUTHWEST AT THIS TIME.
KMD
&&
.LONG TERM...
407 AM CDT
SUNDAY NIGHT THROUGH THURSDAY...
.LONG TERM...
AN UPPER LEVEL LOW QUICKLY MOVES EASTWARD THROUGH SOUTHERN ONTARIO SUNDAY
NIGHT INTO MONDAY...AS THIS OCCURS AND A DEEP TROUGH BUILDS ALONG
THE PACIFIC COAST...UPPER LEVEL RIDGING IN THE WEST WILL CONTINUE
TO AMPLIFY THE FLOW PATTTERN. NW FLOW ON MONDAY WILL KEEP A CHANCE
FOR SHOWERS AND STORMS AROUND AS A WEAK COLD FRONT MOVES THROUGH.
ANOTHER DISTURBANCE GLIDES BY TO OUR NORTH TUESDAY FOR A SOMEWHAT
COOLER THORUGH GENERALLY DRY DAY. A STRAY SHOWER IS POSSIBLE. HIGH
PRESSURE BUILDS IN FOR MID WEEK.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 09Z...
* LAKE BREEZE/SHIFT TO EAST/SOUTHEAST WINDS THIS AFTERNOON.
* POSSIBLE SCATTERED SHOWERS LATE IN THE FORECAST PERIOD.
RODRIGUEZ
//DISCUSSION...UPDATED 06Z...
VFR CONDITIONS IN PLACE EARLY THIS MORNING...WITH LIGHT WINDS AND
ONLY HIGH LEVEL CLOUD COVER IN PLACE. VFR CONDITIONS ARE EXPECTED
MOST OF THE FORECAST PERIOD...WHILE SOUTHERLY WINDS STEADILY
INCREASE LATER THIS MORNING. MONITORING SHOWERS/THUNDERSTORMS TO
THE NORTHWEST MOVING THROUGH PORTIONS OF IOWA AND
WISCONSIN...LIKELY CONTINUING EAST THIS MORNING.
HOWEVER...SOUTHERN EXTENT OF THIS PRECIP SHIELD WILL LIKELY ERODE
KEEPING DRY CONDITIONS ACROSS THE TERMINALS THROUGH MIDDAY. THIS
SYSTEM/FRONT WILL SHIFT EAST LATER TODAY WITH ADDITIONAL SHOWERS
AND THUNDERSTORMS LIKELY PUSHING TOWARDS THE TERMINALS IN THE
AFTERNOON...WITH RFD HAVING THE HIGHER CHANCES OF OBSERVING THIS
PRECIP. THE REMAINING TERMINALS WILL THEN HAVE THESE HIGHER
CHANCES BY THE EVENING. WITH SOME POTENTIAL FOR THIS PRECIP TO
STAY NORTH THIS EVENING...HAVE EXCLUDED ANY MENTION FOR THE OTHER
TERMINALS AT THIS TIME.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 09Z...
* MEDIUM CONFIDENCE FOR WINDS/LAKE BREEZE TODAY.
* LOW MEDIUM CONFIDENCE FOR SHOWERS.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z...
* SATURDAY...DRY/VFR. SOUTHEAST WINDS.
* SUNDAY...CHANCE OF SHRA/TSRA. SOUTHEAST WINDS.
* MONDAY...CHANCE OF SHRA/TSRA. NORTHEAST WINDS.
* TUESDAY AND WEDNESDAY...DRY/VFR. NORTH/NORTHEAST WINDS.
&&
.MARINE...
302 AM CDT
LIGHTER EASTERLY WINDS IN PLACE EARLY THIS MORNING WILL OBSERVE A
STEADY INCREASE TODAY WHILE SHIFTING TO MORE OF A SOUTHERLY
COMPONENT...AS LOW PRESSURE TO THE WEST OVER THE NORTHERN PLAINS
SLOWLY PUSHES EAST. STILL THINK A 10 TO 20 KT WIND WILL BE THE
HIGHEST TODAY...BUT SOME GUIDANCE IS HINTING AT POSSIBLE HIGHER
SPEEDS THROUGHOUT THE DAY. ALTHOUGH I DID INCREASE SPEEDS...DID
NOT GO AS HIGH. HOWEVER...DID MENTION A FEW GUSTS TO 25KT FOR THE
OPEN WATERS TODAY. IT DOES LOOK LIKE A BETTER WINDOW FOR STRONGER
WINDS OF 15 TO 25 KT ACROSS THE NORTH TONIGHT INTO SATURDAY
MORNING...AND HAVE TRENDED THAT WAY WITH THE FORECAST. THIS WILL
BE IN RESPONSE TO THE APPROACHING LOW...BUT WITH IT
WEAKENING...SPEEDS WILL DIMINISH SATURDAY INTO SATURDAY NIGHT.
EXACT TIMING AND PLACEMENT OF THE NEXT SYSTEM LATE IN THE WEEKEND
IS STILL UNCERTAIN BUT IT DOES APPEAR TO BE ANOTHER PERIOD WHEN
SPEEDS WILL ONCE AGAIN INCREASE...AT LEAST FOR THE SOUTHERN HALF
OF THE LAKE.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
353 AM CDT FRI AUG 7 2015
.SHORT TERM...
349 AM CDT
THROUGH SUNDAY...
CONCERNS REVOLVE AROUND PRECIPITATION CHANCES EACH OF THE NEXT FEW
DAYS.
A COMPACT BUT POTENT UPPER LEVEL DISTURBANCE IN MN IS PRODUCING A
COMPLEX OF THUNDERSTORMS NOW MOVING INTO WESTERN WISCONSIN. THERE IS
A WEAK SURFACE REFLECTION WITH THIS FEATURE WHERE THE MORE ORGANIZED
ACTIVITY IS ONGOING. CLOSER TO HOME...SURFACE HIGH PRESSURE IS
HOLDING FIRM JUST NEAR LAKE HURON...WITH THE RIDGE AXIS ORIENTED
SOUTHWESTWARD. IR IMAGERY EARLY THIS MORNING HAS SHOWN A CONTINUAL
EROSION OF THE DEEPER CLOUDS ON THE SOUTHERN END OF THIS COMPLEX AS
IT MOVES INTO DRIER AIR FARTHER SOUTH AND EAST.
AN UPPER LEVEL JET MOVING INTO THE NORTHERN PLAINS WILL ALLOW THIS
UPPER DISTURBANCE TO MOVE SOUTH AND EAST TOWARD THE AREA
TODAY...EVEN OUTRUNNING THE SURFACE LOW. MUCH OF THE NEAR TERM
GUIDANCE KEEPS ERODING PRECIP SOUTH OF THE WISCONSIN BORDER AHEAD OF
THIS SYSTEM. THE EXCEPTION TO THIS THE EXPERIMENTAL HRRR AND SEVERAL
HOP-WRF MEMBERS WHICH ARE QUITE A BIT MORE AGGRESSIVE WITH DRIVING
PRECIP THROUGH THE AREA LATER THIS MORNING/EARLY AFTERNOON.
OBSERVATIONS SUGGEST SOME CONTINUED DEVELOPMENT SOUTHWARD THROUGH
THE MORNING INTO THE INSTABILITY AXIS WHICH WILL GRADUALLY APPROACH
FROM THE WEST TODAY. HAVE STILL KEPT POPS ON THE LOWER SIDE AWAY
FROM NORTH CENTRAL ILLINOIS AND POINTS WEST...THOUGH EXPECT OUR
NORTHWESTERN ZONES INTO WINNEBAGO/BOONE/MCHENRY COUNTIES STAND A
DECENT CHANCE OF SOME SHOWERS AND THUNDERSTORMS LATER THIS MORNING
INTO THE AFTERNOON. CONTINUED DRY AIR SHOULD FURTHER ERODE AT THE
PRECIP...THOUGH AS THE DAY GOES ON AND THE INSTABILITY AXIS SHIFTS
EASTWARD WITH THE UPPER LOW...EXPECT THAT SOME SHOWERS WILL
AROUND...WITH THE BETTER CHANCE FOR A STORM IN NORTH CENTRAL
ILLINOIS.
TONIGHT...THE UPPER LOW SHIFTS EAST AND OUTPACES THE SURFACE LOW AND
THUS EXPECT SOME DECREASE IN COVERAGE OF SHOWERS...THOUGH WILL HANG
ONTO A LOW POP MENTION OVERNIGHT FOR SOME LINGERING LOW LEVEL
CONVERGENCE.
SATURDAY...FOCUS SHIFTS TO ENERGY PROPAGATING FROM THE TROUGH OFF
THE CA COAST THIS MORNING. THIS IS FORECAST TO RIDE A DECENT UPPER
JET THROUGH THE PLAINS OVERNIGHT INTO THE MORNING AND ALONG THE
NORTHERN FRINGES OF THE UPPER LEVEL RIDGE AXIS THAT EXTENDS FROM
TEXAS NORTH INTO THE CENTRAL PLAINS. THIS WAVES CRUISES THROUGH
SATURDAY MORNING WITH SURFACE HIGH PRESSURE IN PLACE AND A LACK OF
DEEPER MOISTURE...SO HAVE CONTINUED A DRY FORECAST...AND THAT GOES
FOR SATURDAY AFTERNOON AS WELL AS THE WAVE MOVES EAST. WILL HAVE TO
WATCH THE MORNING PERIOD IF THE LOWER LEVELS MOISTEN UP A BIT MORE
THAN FORECAST THAT A STRAY SHOWER OR STORM WOULD BE POSSIBLE. THE
NAM IS A LITTLE SLOWER WITH THIS WAVE...BUT STILL DRY IN THE
AFTERNOON AS THE STRONGER FORCING REMAINS TO OUR WEST.
CHANCES FOR SHOWERS AND STORMS INCREASE SATURDAY NIGHT INTO SUNDAY
MORNING AS WE GET A BETTER CO-LOCATION OF DEEPER MOISTURE TRANSPORT
COURTESY OF A DECENT LOW LEVEL JET...ANOTHER PACIFIC
DISTURBANCE...AND PWATS APPROACHING 2 INCHES. WE HANG ONTO SE FLOW
AT THE SURFACE FARTHER EAST...WHICH WOULD THEN GIVE THE HIGHER
CONCERN FOR MODERATE TO HEAVY PRECIP RATES SOUTH AND WEST. THERE
IS A SEVERE THREAT GIVEN THE MODEST WESTERLY FLOW NORTH OF THE
RIDGE...BUT DESTABILIZATION CONCERNS EXIST AT THIS POINT IN TIME
TO NAIL DOWN THE SPECIFICS YET.
KMD
&&
.LONG TERM...
303 PM CDT
MORNING LONG TERM DISCUSSION FORTHCOMING...PREVIOUS DISCUSSION
FOLLOWS.
FRIDAY NIGHT THROUGH THURSDAY...
THE GENERAL TREND FOR THE EXTENDED FORECAST PERIOD WILL BE FOR A
SLOWLY PROGRESSIVE UPPER LEVEL PATTERN THAT TRANSITIONS FROM A LOW
AMPLITUDE PATTERN TO ONE OF HIGH AMPLITUDE LONG WAVELENGTH. AT THE
BEGINNING OF THE EXTENDED PERIOD...BROAD RIDGING COVERS THE CNTRL
CONUS AND TROUGHING OVER THE WEST AND EAST COASTS.
FOR FRIDAY NIGHT THROUGH MONDAY NIGHT...THE MAIN CONCERNS WILL BE A
SERIES OF WEAK SHORTWAVES OVERTOPPING THE RIDGE. THESE SHORTWAVES
WILL BE THE MAIN FORCING FOR PERIODIC CHANCES FOR SHRA/TSRA. A DEEP
UPPER LOW CROSSING THE CANADIAN PRAIRIES WILL BEGIN TO SUPPRESS THE
RIDING OVER THE NRN PLAINS/GREAT LAKES REGIONS. THROUGH THE
WEEKEND...THE MAIN TRACK OF SHORTWAVE ENERGY WILL SHIFT TO THE SOUTH
WITH UPPER LEVEL FLOW GRADUALLY SHIFTING TO NWLY ALOFT AS THE UPPER
RIDGE BUILDS BACK OVER THE ROCKIES AND A LONG WAVE TROUGH DIGS OVER
THE EAST COAST. THE NEXT EFFECT OF THE PATTERN SHIFT IS TO RELOCATE
THE FOCUS OF PCPN POTENTIAL FROM THE UPPER MIDWEST AND GREAT LAKES
TO THE MIDDLE MISSISSIPPI AND OHIO VALLEYS. THE MOST LIKELY CHANCES
FOR PCPN ACROSS THE CWA WILL BE DURG THE PERIOD FROM LATE SATURDAY
NIGHT INTO EARLY MONDAY...THOUGH THERE MAY STILL BE A LINGERING
CHANCE FOR SOME SHRA/TSRA FRIDAY EVENING GENERALLY FOR THE NRN
PORTIONS OF THE CWA. WHILE THE LARGER SCALE MODELS HAVE A DECENT
HANDLE ON THE GENERAL PATTERN...TIMING DIFFERENCES FOR THE WEAK
SHORTWAVES INTRODUCE A FAIR AMOUNT OF UNCERTAINTY TO TIMING OF PCPN
IMPACTING THE REGION. BY MONDAY NIGHT AND THROUGH EARLY NEXT
WEEK...THE UPPER RIDGE WILL GRADUALLY BUILD EAST ACROSS THE CNTRL
PLAINS...SHIFTING THE NWLY FLOW AND SHORTWAVE TRACK TO THE
EAST...KEEPING THE REMAINDER OF THE EXTENDED PERIOD DRY.
THE TEMPERATURE TREND THROUGH THE EXTENDED PERIOD WILL BE FOR
GENERALLY BELOW NORMAL TEMPERATURES UNDER THE NWLY FLOW ALOFT. FOR
THE WEEKEND AND INTO EARLY NEXT WEEK...HIGHS SHOULD BE IN THE LOWER
80S...WITH LOWS IN THE 60S. BY EARLY NEXT WEEK...TEMPERATURES WILL
TREND A BIT LOW AS SFC HIGH PRESSURE BUILDS ACROSS THE REGION
SETTING UP FLOW OFF OF THE LAKE. FOR THE MIDDLE OF NEXT WEEK...HIGHS
SHOULD ONLY BE IN THE MIDDLE TO UPPER 70S WITH LOWS IN THE UPPER
50S.
KREIN
&&
.CLIMATE...
309 AM CDT
THURSDAY WAS THE 20TH CONSECUTIVE DAY WITH HIGH TEMPERATURES AT OR
ABOVE 80F OFFICIALLY FOR ROCKFORD AND CHICAGO. CURRENT FORECAST
WOULD SUGGEST AT LEAST ANOTHER 4 DAYS...POSSIBLY MORE TACKED ON TO
THE CURRENT STREAK DURING THE NEXT 7 DAYS. FOR ROCKFORD...IT IS
NOT ALL THAT UNCOMMON FOR LONG STRETCHES OF 80F+ WEATHER IN THE
SUMMER DUE TO THEIR GREATER DISTANCE FROM THE COOLING EFFECTS OF
LAKE MICHIGAN. IN FACT...ASSUMING THE CURRENT STREAK REACHES 24
DAYS IN ROCKFORD THAT WOULD JUST BARELY BREAK THE TOP 50 FOR
LONGEST STRETCHES OF 80F OR GREATER HIGHS. THE LONGEST STRETCH WAS
86 DAYS BACK IN 1895...THOUGH MORE RECENTLY IN 2012 THERE WAS A 56
DAY STRETCH OF HIGHS AT OR ABOVE 80 EVERY DAY.
FOR CHICAGO...THANKS TO THE COOLING EFFECTS OF LAKE MICHIGAN IT IS
MORE UNUSUAL TO SEE STREAKS OF GREATER THAN 3 WEEKS OF HIGHS 80 OR
ABOVE. ASSUMING THE CURRENT STREAK CONTINUES THROUGH SUNDAY AS
FORECAST THAT WOULD BRING THE TOTAL UP TO 24 DAYS STRAIGHT WHICH
WOULD PUT MAKE THIS STREAK ONE OF THE TOP 15 LONGEST ON RECORD.
HERE ARE THE TOP 15 LONGEST STREAKS OF DAYS WITH HIGHS 80F OR
ABOVE IN CHICAGO...
RANK # DAYS END DATE
1 46 8/16/2010 <--
2 44 8/ 8/2012 <--
3 42 8/ 7/1955
4 34 9/ 6/1995
5 32 8/ 8/1983
6 30 7/19/1921
7 29 8/18/1988
8 27 8/ 9/2011 <--
27 8/ 6/1999
27 7/14/1966
11 25 8/15/2007 <--
12 24 7/26/2005 <--
24 9/ 5/1983
24 8/25/1947
15 23 8/ 7/1987
23 7/ 9/1949
ASSUMING THE CURRENT STREAK REACHES AT LEAST 24 DAYS AS
FORECAST...THEN 6 OUT OF THE TOP 15 LONGEST STREAKS OF 80F OR
GREATER DAYS IN CHICAGO WILL HAVE OCCURRED SINCE 2005...4 OF THOSE
YEARS WILL HAVE BEEN SINCE 2010 ALONE!
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* LAKE BREEZE/SHIFT TO EAST/SOUTHEAST WINDS THIS AFTERNOON.
* POSSIBLE SCATTERED SHOWERS LATE IN THE FORECAST PERIOD.
RODRIGUEZ
//DISCUSSION...UPDATED 06Z...
VFR CONDITIONS IN PLACE EARLY THIS MORNING...WITH LIGHT WINDS AND
ONLY HIGH LEVEL CLOUD COVER IN PLACE. VFR CONDITIONS ARE EXPECTED
MOST OF THE FORECAST PERIOD...WHILE SOUTHERLY WINDS STEADILY
INCREASE LATER THIS MORNING. MONITORING SHOWERS/THUNDERSTORMS TO
THE NORTHWEST MOVING THROUGH PORTIONS OF IOWA AND
WISCONSIN...LIKELY CONTINUING EAST THIS MORNING.
HOWEVER...SOUTHERN EXTENT OF THIS PRECIP SHIELD WILL LIKELY ERODE
KEEPING DRY CONDITIONS ACROSS THE TERMINALS THROUGH MIDDAY. THIS
SYSTEM/FRONT WILL SHIFT EAST LATER TODAY WITH ADDITIONAL SHOWERS
AND THUNDERSTORMS LIKELY PUSHING TOWARDS THE TERMINALS IN THE
AFTERNOON...WITH RFD HAVING THE HIGHER CHANCES OF OBSERVING THIS
PRECIP. THE REMAINING TERMINALS WILL THEN HAVE THESE HIGHER
CHANCES BY THE EVENING. WITH SOME POTENTIAL FOR THIS PRECIP TO
STAY NORTH THIS EVENING...HAVE EXCLUDED ANY MENTION FOR THE OTHER
TERMINALS AT THIS TIME.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM CONFIDENCE FOR WINDS/LAKE BREEZE TODAY.
* LOW MEDIUM CONFIDENCE FOR SHOWERS.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z...
* SATURDAY...DRY/VFR. SOUTHEAST WINDS.
* SUNDAY...CHANCE OF SHRA/TSRA. SOUTHEAST WINDS.
* MONDAY...CHANCE OF SHRA/TSRA. NORTHEAST WINDS.
* TUESDAY AND WEDNESDAY...DRY/VFR. NORTH/NORTHEAST WINDS.
&&
.MARINE...
302 AM CDT
LIGHTER EASTERLY WINDS IN PLACE EARLY THIS MORNING WILL OBSERVE A
STEADY INCREASE TODAY WHILE SHIFTING TO MORE OF A SOUTHERLY
COMPONENT...AS LOW PRESSURE TO THE WEST OVER THE NORTHERN PLAINS
SLOWLY PUSHES EAST. STILL THINK A 10 TO 20 KT WIND WILL BE THE
HIGHEST TODAY...BUT SOME GUIDANCE IS HINTING AT POSSIBLE HIGHER
SPEEDS THROUGHOUT THE DAY. ALTHOUGH I DID INCREASE SPEEDS...DID
NOT GO AS HIGH. HOWEVER...DID MENTION A FEW GUSTS TO 25KT FOR THE
OPEN WATERS TODAY. IT DOES LOOK LIKE A BETTER WINDOW FOR STRONGER
WINDS OF 15 TO 25 KT ACROSS THE NORTH TONIGHT INTO SATURDAY
MORNING...AND HAVE TRENDED THAT WAY WITH THE FORECAST. THIS WILL
BE IN RESPONSE TO THE APPROACHING LOW...BUT WITH IT
WEAKENING...SPEEDS WILL DIMINISH SATURDAY INTO SATURDAY NIGHT.
EXACT TIMING AND PLACEMENT OF THE NEXT SYSTEM LATE IN THE WEEKEND
IS STILL UNCERTAIN BUT IT DOES APPEAR TO BE ANOTHER PERIOD WHEN
SPEEDS WILL ONCE AGAIN INCREASE...AT LEAST FOR THE SOUTHERN HALF
OF THE LAKE.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
254 AM EDT FRI AUG 7 2015
.SHORT TERM...TODAY AND TONIGHT
UPPER SHORTWAVE OVER THE UPPER MIDWEST WILL TRACK ACROSS MICHIGAN
LATE TODAY AND TONIGHT AS IT RIDES ALONG THE NORTHERN PERIPHERY OF
AN UPPER RIDGE CENTERED OVER THE SOUTHERN PLAINS. THIS SHORTWAVE HAS
BEEN LOOKING MORE IMPRESSIVE ON WATER VAPOR AS THE NIGHT
PROGRESSES...AND HAS BEEN KICKING OFF A PRETTY GOOD COVERAGE OF
SHOWERS AND THUNDERSTORMS OVER MINNESOTA AND WISCONSIN. 00Z NAM/GFS
ONLY CREDIT THIS WAVE WITH A MODEST PUSH OF MID-LEVEL THETA-E
ADVECTION LATE TODAY/TONIGHT...AND LITTLE TO NO QPF OUTPUT OVER THE
AREA. ACTUALLY PREFER THE MORE AGRESSIVE SOLUTIONS SUCH AS THE
12Z/00Z EURO AND THE HRRR (EVEN THOUGH IT DOESN`T GO OUT QUITE FAR
ENOUGH YET) GIVEN APPEARANCE ON WATER VAPOR. INHERITED FORECAST WAS
ALREADY ON THE AGGRESSIVE SIDE AND CHANGES TO THE FORECAST WERE
MAINLY TO ADJUST TIMING AND INCREASE POPS SLIGHTLY OVER THE SAGINAW
VALLEY. SHOWERS AND PERHAPS A THUNDERSTORM COULD ARRIVE INTO THE
WESTERN PORTION OF THE FORECAST AREA AS EARLY AS 20Z/4PM. BEST
POTENTIAL STILL LOOKS BETWEEN BETWEEN 8PM AND 2AM...AHEAD OF THE
UPPER WAVE AS IT TRACKS INTO MICHIGAN. HIGHEST POPS OVERALL REMAIN
OVER THE SAGINAW VALLEY (MID-RANGE CHANCE)...AND THEN TAPER TO JUST
A SLIGHT CHANCE TOWARDS THE DETROIT AND ANN ARBOR AREAS. ALTHOUGH IT
IS ONLY 12-24 HOUR OUT...MODELS ARE STILL STRUGGLING A LITTLE WITH
TRACK AND TIMING OF THIS SMALL FEATURE. THIS LEADS TO LOWER
CONFIDENCE REGARDING COVERAGE AND TIMING OVERALL.
WITH PLENTY OF HIGH CLOUDS STREAMING IN AHEAD OF THIS UPPER WAVE FOR
THE EARLY PART OF THE DAY...AND A LIGHT EAST FLOW OFF THE
LAKES...EXPECT MAX TEMPERATURES TO CONTINUE RUNNING SLIGHTLY BELOW
NORMAL IN THE MID 70S TO NEAR 80. CLOUD COVER WILL THEN KEEP MIN
TEMPS MILD TONIGHT IN THE UPPER 50S TO LOW 60S.
&&
.LONG TERM...
ASIDE FROM A FEW LINGERING SHOWERS OVER THE NORTHERN FORECAST AREA
SATURDAY MORNING...EXPECT A BULK OF THE WEEKEND TO REMAIN DRY AS A
RIDGE OF SURFACE HIGH PRESSURE PERSISTS FROM EASTERN ONTARIO BACK
INTO LAKE HURON AND SOUTHEAST MICHIGAN. A SUBTLE SHORTWAVE RIDGE
WILL ALSO BUILD THROUGH THE AREA AS A FILLING UPPER LOW PRESSURE
SYSTEM LUMBERS EAST ACROSS SOUTHERN CANADA. THIS WILL PROVIDE A
SLIGHTLY WARMER AIRMASS AND ALLOW MAXIMUM TEMPERATURES TO CLIMB INTO
THE LOWER 80S IN MANY AREAS BOTH SATURDAY AND SUNDAY AFTERNOON.
AS THE AFOREMENTIONED RIDGE SHIFTS EAST OF THE AREA EARLY NEXT WEEK
AND MEAN TROUGH AXIS ASSOCIATED WITH WHAT STILL EXISTS OF SOUTHERN
CANADA UPPER LOW ENCROACHES ON THE CENTRAL GREAT LAKES...EXPECT RAIN
CHANCES TO INCREASE FROM SUNDAY EVENING/NIGHT INTO MONDAY. THIS WILL
BE FURTHER ENHANCED AS ADDITIONAL SHORTWAVE ENERGY CURRENTLY OFF THE
CALIFORNIA COAST GRADUALLY WORKS NORTHEAST INTO THE NORTHERN ROCKIES
AND PLAIN STATES AND IS EVENTUALLY FUNNELED INTO THE GREAT LAKES
AROUND THE SOUTHERN PERIPHERY OF LEAD SYSTEM IN CANADA.
ONCE EAST OF THE AREA BY MID NEXT WEEK...THIS SYSTEM WILL AMPLIFY
OVER EASTERN CANADA AND LEAD TO A RATHER NOTABLE UPPER TROUGH FROM
THE CENTRAL/EASTERN GREAT LAKES INTO EASTERN CANADA/NORTHEAST CONUS.
EXPECT DRIER WEATHER WITHIN NORTH/NORTHWEST FLOW ON THE BACK SIDE OF
THIS DEVELOPING TROUGH. THIS EVOLVING PATTERN WILL ALSO LEAD TO
COOLER READINGS ONCE AGAIN WITH MID 70S COMMON FOR AFTERNOON HIGH
TEMPERATURES MID/LATE NEXT WEEK.
&&
.MARINE...
HIGH PRESSURE CENTERED OVER LAKE HURON WILL SUSTAIN A LIGHT WIND
INTO TODAY...WITH JUST A MODEST INCREASE IN NORTHEAST WIND LATE IN
THE DAY LEADING TO SOME ENHANCED WAVE DEVELOPMENT OVER THE NEARSHORE
WATERS BY THIS EVENING. GENERALLY WEAKER EAST TO SOUTHEAST WINDS
WILL THEN HOLD THROUGH THE WEEKEND AS THE HIGH PRESSURE CENTER
REMAINS POSITIONED JUST NORTHEAST OF THE REGION.
&&
.AVIATION...ISSUED 1159 PM EDT THU AUG 6 2015
WEAK HIGH PRESSURE WILL REMAIN POSITIONED OVER SE MICHIGAN DURING
THE REST OF THE NIGHT AND THROUGH THE DAY/THURSDAY. WEAK LOW
PRESSURE OVER THE MIDWEST WILL SEND GENEROUS COVERAGE OF HIGH
CLOUDS OVER THE TERMINAL CORRIDOR WHICH WILL HELP PREVENT ANY
MEANINGFUL FOG AS THE WIND BECOMES LIGHT AND VARIABLE OR CALM
TOWARD SUNRISE. IF THERE IS ANY WIND...IT WILL BE LIGHT AND FROM
AN EASTERLY DIRECTION THROUGH THE DAY. VARYING AMOUNTS OF HIGH
CLOUDS WILL COMBINE WITH SOME POCKETS OF CUMULUS BY MID AFTERNOON
TO PRODUCE VFR CEILING ABOVE 5000 FEET AT TIMES. SPRINKLES OR
LIGHT RAIN SHOWERS MAY BE ABLE TO REACH THE FNT AND MBS AREAS
FRIDAY EVENING BUT WITH LOW COVERAGE EXPECTED AT THIS POINT WITH
NO RESTRICTIONS.
//DTW THRESHOLD PROBABILITIES...
* NONE.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
SHORT TERM...HLO
LONG TERM....DG
MARINE.......DG
AVIATION.....BT
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
324 AM CDT FRI AUG 7 2015
.SHORT TERM...(Today and Tonight)
Issued at 0322 AM CDT FRI AUG 07 2015
Convection has developed over southwestern Missouri fueled by a
shortwave aloft and modest low level jet/moisture transport. HRRR
and RAP has good handle on this and pushes it southeast into south
central Missouri shortly after 12Z and should weaken and dissipate
through midday. After that, upper level high over the southern
plains and southwest conus will expand northeast towards the
Ozarks later today and tonight. This will be the beginning of
warming temperatures. Expect mainly sunny skies by this afternoon
which will aid in the rise. Expect warmest readings across
southeast Kansas into southwest Missouri where highs will be in
the lower to middle 90s, and just middle 80s over the eastern
Ozarks. Heat index values will flirt with advisory criteria for a
few hours this afternoon over southeast Kansas and southwest
Missouri, but will hold off on any headlines. A warm and humid
night is in store tonight with lows in the lower to middle 70s.
.LONG TERM...(Saturday through Thursday)
Issued at 0322 AM CDT FRI AUG 07 2015
Main forecast concern in this time frame is heat and heat index
values for both Saturday and Sunday and the need for any heat
related headlines. Upper ridge firmly in place across the Ozarks
both days. The hottest days looks to be Sunday with heat index
values in the 105 to 110 degree range. will likely need advisories
area-wide Sunday and perhaps only the western half of the forecast
area Saturday.
Medium range models continue to advertise a shortwave breaking down
the northern extent of the ridge Sunday night and Monday allowing
for a frontal boundary to make into the area. This will bring rain
chances back into the forecast, with the better chances across
central Missouri. It will also help cool temperatures off. This
wave should be east of the area later Monday with northwest flow
and surface high pressure nudging into the area for Tuesday
through Thursday, for cooler and quieter weather.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday Night)
Issued at 1130 PM CDT THU AUG 06 2015
VFR conditions at area terminals will persist much of the
overnight. However changes are anticipated overnight as scattered
showers and thunderstorms develop from southeastern Kansas into
southwestern Missouri north of a warm front. This could result in
thunderstorms in the terminal vicinities and intervals of MVFR
conditions. The scattered storms will diminish by midday Friday as
the warm front lifts north. Expect an increase in southerly winds
by Friday afternoon.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
SHORT TERM...Raberding
LONG TERM...Raberding
AVIATION...Foster
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
341 AM CDT FRI AUG 7 2015
.SYNOPSIS...
ISSUED AT 341 AM CDT FRI AUG 7 2015
AT H5 UPPER RIDGE CENTERED OVER TEXAS WITH WEAK RIDGING INTO
NORTHERN PLAINS. THIS RIDGE IS BEING KNOCKED DOWN BY CLOSED LOW
ALONG THE CANADIAN BORDER. AN UPPER WAVE MOVING ACROSS WISCONSIN
INTO THE GREAT LAKES REGION AND ANOTHER WAVE...TROUGH OVER THE
CAROLINAS AND NORTHERN FLORIDA. CLOSED LOW MOVING ONSHORE IN
CENTRAL CALIFORNIA WITH MOISTURE STREAMING NORTH ALONG MEXICAN
COAST ON THE BACKSIDE OF THE RIDGE WRAPPING INTO LOW OVER
CALIFORNIA.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 341 AM CDT FRI AUG 7 2015
MODELS DIFFER SOME IN THE SHORT TERM WITH NAM FAVORING A MORE
NORTHERLY TRACK FFOR WESTERN NEBRASKA BUT GFS AND GEM HAVE BEEN
FAVORING INTERSTATE 80 CORRIDOR THE LAST SEVERAL DAYS. GREETED BY
FOG AGAIN THIS MORNING BUT NOT AS DENSE OR WIDESPREAD AS THE LAST
SEVERAL DAYS. WILL BLEND THE GFS AND NAM SOLUTIONS. TIMING OF
WAVES MOVING THROUGH SOUTHWEST FLOW WILL BRING INITIATION OVER THE
WEST THROUGH THE AFTERNOON ALONG INVERTED SURFACE TROUGH ACROSS
THE PANHANDLE. 850MB LLJ KICKING IN EARLY AND MOVING EAST THROUGH
THE EARLY EVENING AND INCREASING TO AROUND 50KTS. STRONG WARM AIR
AND MOISTURE ADVECTION AHEAD OF THE SYSTEM THROUGH THE LATE
MORNING INTO EARLY EVENING. PWATS LAST NIGHT AROUND 11O PERCENT OF
NORMAL AT KLBF WITH 1.04 AND 127 PERCENT OF NORMAL AT KDDC WITH
1.28 INCHES. TDS IN THE MID 60S AND INCREASING INTO THE UPPER 60S
THIS AFTERNOON. OUTLOOKED WITH SLIGHT RISK ALL OF WESTERN
NEBRASKA. UPSLOPE FLOW...BULK SHEAR 30 TO 40KTS FAVORABLE FOR
SUPER CELL DEVELOPMENT. MU CAPE LATE AFTERNOON IN THE 2500-3000
J/KG. HIGHS AROUND 90 THIS AFTERNOON. FOG LAYER IS SHALLOW ENOUGH
THAT IT SHOULD NOT IMPEDE DAYTIME INSOLATION AS MUCH AS IT HAS THE
LAST SEVERAL DAYS. STRONG TO SEVERE STORMS EXPECTED TO CONGEAL
INTO MCS AND SHIFT EAST WITH THE LOW LEVEL JET AND UPPER FORCING.
EFFICIENT RAIN PROCESSES WILL KEEP THE FLASH FLOOD WATCH GOING
OVER THE WEST. HAVE INCLUDED MODERATE RAIN THROUGH THE AFTERNOON
AND THEN HEAVY RAIN THROUGH THE EVENING. LOWS IN THE 60S.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 341 AM CDT FRI AUG 7 2015
12Z SATURDAY AND BEYOND. THE MCS WILL CONTINUE ACROSS EASTERN
PORTIONS OF THE FORECAST AREA SATURDAY MORNING...WITH CLEARING
COMMENCING FROM WEST TO EAST. A GENERAL MODEL CONSENSUS WOULD
INDICATE ADDITIONAL QPF OF A FEW TENTHS OF AN INCH ACROSS NORTH
CENTRAL NEBRASKA...BUT NO MORE...THUS THE HEAVY RAIN THREAT WILL
DIMINISH AND SEE NO REASON TO EXTEND THE FLASH FLOOD WATCH BEYOND
11Z.
LATE AFTERNOON SATURDAY THE MODELS SEEM TO BE KEYING ON
ADDITIONAL DEVELOPMENT OF THUNDERSTORMS AS A DISTURBANCE/WAVE
WORKS IN CONJUNCTION WITH A LINGERING SURFACE TROUGH AND RIDGING
OF RICH THETA-E AIR ACROSS THE PANHANDLE. THE MAJORITY OF THE
QPF/HIGHEST CHANCES REMAIN OFF TO OUR NORTH AND WEST HOWEVER AS
THERE REMAINS LITTLE SUPPORT FOR A SUSTAINED COMPLEX. WILL
MAINTAIN THE HIGHEST POPS DURING THIS TIME PERIOD ACROSS NORTHWEST
NEBRASKA...BUT AT THAT WILL KEEP POPS AT 40 PERCENT OR LESS.
LINGERING CHANCES OF POPS TARGET MAINLY OUR NORTHERN ZONES ON
SUNDAY AS THE WAVE PROGRESSES EAST ACROSS THE NORTHERN PLAINS. A
WEAK BOUNDARY MAY SPARK OFF ADDITIONAL THUNDERSTORMS ACROSS OUR
EAST SUNDAY NIGHT AND INTO MONDAY...HOWEVER THE BEST MOISTURE AND
INSTABILITY ARE PROGGED TO BE EAST OF THE FORECAST AREA.
FOR NEXT WEEK...A WARMING AND DRYING TREND IS FORECAST AS LONGWAVE
RIDGING AMPLIFIES OVER THE CENTRAL CONUS...WITH BOOKEND VORTICIES
OVER THE NORTHWESTERN AND NORTHEASTERN COASTS. THE WARMEST
CONDITIONS APPEAR TO ARRIVE MID TO LATE WEEK WHEN TEMPERATURES
CLIMB ONCE AGAIN ABOVE AVERAGE. A CAPPING INVERSION IS SHOWN TO BE
QUITE STRONG DURING THE PERIOD...BUT A STEADY TAP OF LL MOISTURE
WOULD PROVIDE AT LEAST FOR A PERIODIC ISOLATED TO SCATTERED
MENTION OF STORMS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1128 PM CDT THU AUG 6 2015
FOG IS BEGINNING TO FORM IN THE PLATTE VALLEY AND REPUBLICAN
VALLEY. THE NAM...RAP AND HRRR SHOW FOG FORMING IN THESE AREAS AND
SPREADING NORTH AND WEST INTO THE SRN SANDHILLS TONIGHT. BURNOFF
IS EXPECTED BY 15Z-16Z. VFR IS EXPECTED THRU 16Z-21Z. THEREAFTER
THUNDERSTORMS SHOULD MOVE INTO WRN NEB...BECOME NUMEROUS...AND
SPREAD SOUTH AND EAST THROUGH THE FCST FRIDAY EVENING.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM THIS EVENING THROUGH LATE TONIGHT FOR
NEZ022-035>038-056>059-069>071.
&&
$$
SYNOPSIS...POWER
SHORT TERM...POWER
LONG TERM...JACOBS
AVIATION...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1128 PM CDT THU AUG 6 2015
.SYNOPSIS...
ISSUED AT 350 PM CDT THU AUG 6 2015
H5 ANALYSIS FROM THIS MORNING HAD A TROUGH OF LOW
PRESSURE EXTENDING FROM A CLOSED LOW OVER ALBERTA. THIS TROUGH
EXTENDED SWD INTO CENTRAL IDAHO. EAST OF THE TROUGH...A DECENT LEAD
SHORTWAVE EXTENDED ACROSS ERN MT INTO WESTERN SOUTH DAKOTA. ANOTHER
SHORTWAVE TROUGH EXTENDED FROM SERN WYOMING INTO EASTERN COLORADO.
HIGH PRESSURE REMAINED ANCHORED OVER ERN NEW MEXICO WITH A SECONDARY
LOW NOTED ACROSS THE LOWER OHIO VALLEY. AT THE SURFACE...LOW
PRESSURE WAS LOCATED OVER SOUTH CENTRAL SOUTH DAKOTA WITH A FRONTAL
BOUNDARY EXTENDING SWWD INTO THE SERN NEBRASKA PANHANDLE. EAST OF
THIS FEATURE...WINDS WERE SOUTHERLY AND DEW POINTS WERE IN THE MID
TO UPPER 60S. WEST OF THE FRONT...GUSTY NORTHWESTERLY WINDS AND MUCH
DRIER DEW POINTS IN THE 40S AND LOWER 50S WERE PRESENT ACROSS THE
NEBR PANHANDLE. THUNDERSTORMS FROM EARLIER THIS MORNING...HAD PUSHED
INTO SOUTH CENTRAL NEBRASKA AND NORTHERN KS. SKIES WERE MOSTLY CLEAR
IN THE WAKE OF THE THUNDERSTORMS FROM EARLIER TODAY...HOWEVER...A
STRIP OF LOW CLOUDS EXTENDED FROM SOUTHWESTERN NEBRASKA INTO THE
CENTRAL SANDHILLS. THIS CLOUD COVER HAS HELD TEMPS IN THE 70S THIS
AFTERNOON...WITH 80S NOTED ELSEWHERE.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 350 PM CDT THU AUG 6 2015
MAIN FORECAST CHALLENGE OVER THE NEXT 24 HOURS WILL BE THUNDERSTORM
CHANCES AS A WEAK UPPER LEVEL PV ANOMALY TRACKS ACROSS THE
DAKOTAS...WHICH WILL PUSH A COLD FRONT THROUGH THE CWA. AS OF 20Z
THE FRONT WAS SITUATED FROM NEAR MOBRIDGE SOUTH DAKOTA SOUTHWARD
THROUGH THE WESTERN SANDHILLS. CU FIELD HAS STEADILY DEEPENED ALONG
THE FRONT WITH SHOWERS AND THUNDERSTORMS DEVELOPING AS IT MOVES INTO
AN ENVIRONMENT THAT HAS BECOME INCREASINGLY UNSTABLE. MOST OF THE
CONVECTION HAS BEEN CONTAINED TO THE NE/SD BORDER AND POINTS
NORTHWARD. FURTHER DEVELOPMENT IS EXPECTED ALONG THE FRONT THROUGH
THE EVENING. THE SOUTHWARD EXTENT OF THE CONVECTION IS IN QUESTION
AS CURRENT MESOANALYSIS AND LAPS SOUNDINGS INDICATE A STRONG CAP
SOUTH OF HWY 2...A RESULT OF MORNING CONVECTION AND PERSISTENT
DAYTIME CLOUD COVER. MLCAPE HAS INCREASED TO AOA 1000 J/KG IN AREAS
THAT HAVE SEEN AMPLE SUNSHINE AND BL RECOVERY TODAY...MAINLY IN
NORTH CENTRAL NEBRASKA FROM AINSWORTH TO O`NEILL. DEEP LAYER SHEAR
IS SUPPORTIVE OF ORGANIZED ROBUST UPDRAFTS...SO THIS AREA WILL NEED
TO BE MONITORED FOR COUPLE STRONG TO SEVERE STORMS CAPABLE OF HAIL
AND GUSTY WINDS THROUGH THROUGH THE EVENING HOURS.
PRECIP CHANCES COME TO AN END BEHIND THE FRONT AS WINDS BECOME
NORTHWESTERLY AND DRIER AIR FILTERS IN FROM THE WEST. QUIET AND CALM
CONDITIONS ARE EXPECTED OVERNIGHT AS THE BOUNDARY LAYER DECOUPLES
AND LOCAL SURFACE PRESSURE TENDENCIES RELAX. LARGE SCALE SUBSIDENCE
IN THE WAKE OF THE DEPARTING PV MAX SHOULD CLEAR OUT THE MAJORITY OF
THE CLOUD OVER AS WELL.
SURFACE LEE SIDE TROUGH JUST EAST OF THE FRONT RANGE DEEPENS FRIDAY
AS DPVA INCREASES ALOFT IN ADVANCE OF THE NEXT SHORTWAVE TROUGH TO
IMPACT THE CENTRAL PLAINS. RESPONSE JUST TO THE EAST WILL BE
SOUTHERLY FLOW AND THE POLEWARD ADVECTION OF A VERY MOIST AIRMASS
INTO THE CWA. IN FACT...MODELS ARE IN SOLID AGREEMENT WITH H85
DEWPOINTS AS HIGH AS 16C TO 18C BY LATE AFTERNOON...NEAR THE
CLIMATOLOGY MAX FOR WESTERN NEBRASKA. THETA-E GRADIENT AND DEEP
MOISTURE CONVERGENCE FOCUSES ALONG THE SURFACE TROUGH WITH THE
APPROACH OF THE UPPER LEVEL SHORTWAVE...WHICH SHOULD BE ENOUGH TO
BREAK THE CAP AFTER 18Z OVER THE HIGH PLAINS OF EASTERN WY/CO/NEB
PANHANDLE. A FEW OF THE STORMS MAY MOVE INTO OUR WESTERN CWA BY LATE
AFTERNOON/EARLY EVENING. LARGE HAIL...STRONG GUSTY WINDS...AND HEAVY
RAINFALL WILL BE A CONCERN WITH ANY THUNDERSTORM...BUT THE MOST
WIDESPREAD ACTIVTY WILL MOST LIKELY OCCUR IN OUR CWA AFTER 00Z
SATURDAY.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 350 PM CDT THU AUG 6 2015
FRIDAY NIGHT THROUGH SUNDAY...IN THE MID RANGE...THE
THREAT FOR HEAVY RAIN FRIDAY NIGHT INTO EARLY SATURDAY IS THE MAIN
FORECAST CONCERN. CONVECTION IS EXPECTED TO BE ONGOING LATE FRIDAY
AFTERNOON IN THE PANHANDLE. FURTHER EAST...THE CWA WILL BE FAIRLY
CAPPED FRIDAY AFTERNOON...SO CONVECTIVE INITIATION WILL BE ACROSS
THE NEBR PANHANDLE INVOF OF THE SURFACE TROUGH AND THETAE RIDGE
AXIS. BY EARLY EVENING...THIS CONVECTION WILL TRACK EAST INTO A VERY
MOIST LOW LEVEL ENVIRONMENT. H85 DEW POINTS REACH 14 TO 16C FRIDAY
AFTERNOON ACROSS THE WEST AND SWRN CWA WITH LAYER PWATS REACHING 1.5
TO 1.75 INCHES LATE FRIDAY AFTERNOON. THIS EQUATES TO THE 99TH
PERCENTILE FOR CLIMATOLOGY. THAT BEING SAID...THERE IS A HUGE AMOUNT
OF LOW LEVEL MOISTURE AVAILABLE FOR CONVECTION FRIDAY
AFTERNOON/EVENING. AS THIS CONVECTION MOVES EAST INTO SWRN NEBRASKA
BY EARLY EVENING...ABUNDANT DEEP LAYER SHEAR...ALONG WITH THE NOSE
OF AN H850 LOW LEVEL JET WILL COMBINE OVER SWRN NEBRASKA ENHANCING
CONVECTIVE DEVELOPMENT AS THE INITIAL THUNDERSTORMS MOVE EAST INTO
SWRN NEBRASKA. WITH THESE INGREDIENTS COMING TOGETHER...HEAVY RAIN
AND THE POSSIBILITY OF SEVERE STORMS LOOKS LIKE A DECENT BET FRIDAY
EVENING/FRIDAY NIGHT. THE LATEST NAM...GFS...AND SREF PUSH A MCS
ACROSS SWRN NEBRASKA FRIDAY EVENING INTO PORTIONS OF CENTRAL
NEBRASKA OVERNIGHT. GIVEN THE DEGREE OF MOISTURE...HEAVY RAIN LOOKS
LIKE A GOOD BET AND WITH THE FORECAST DEEP LAYER SHEAR OF 40+
KTS...STORMS HAVE A GOOD POTENTIAL TO BE SEVERE. WITH THE RECENT
HEAVY RAIN ACROSS SOUTHWESTERN NEBRASKA ON TUESDAY...AND ADDITIONAL
HEAVY RAIN IN CUSTER COUNTY FROM EARLIER TODAY...3 HR FFG HAS BEEN
RUNNING AROUND 1.5 INCHES...UP TO 2.0 INCHES. WITH THE NAM AND GFS
DEVELOPING 6 HR QPF`S OF 2 TO 4 INCHES...AND AFTER COORDINATING WITH
WPC...FELT IT NECESSARY TO HOIST A FLASH FLOOD WATCH FOR SWRN
NEBRASKA FOR FRIDAY NIGHT. GIVEN THE STRONG MODEL AGREEMENT WITH
THIS SYSTEM TOMORROW NIGHT...KEEP LIKELY POPS IN THE 70 TO 80
PERCENT RANGE ACROSS SWRN NEBRASKA AND WORDED THE FCST WITH HEAVY
RAIN...PARTICULARLY SOUTH OF A LINE FROM OSHKOSH TO SARGENT...WHERE
THE FLASH FLOOD WATCH WILL BE ISSUED FOR. FOR SATURDAY...CONVECTION
WILL LINGER INTO SATURDAY MORNING IN THE EASTERN CWA WITH MAINLY DRY
CONDS EXPECTED IN THE CENTRAL AND WEST. BY LATE AFTERNOON...THE
MODELS INITIATE CONVECTION IN THE PANHANDLE AND SWRN SD. THIS SEEMS
PLAUSIBLE AS THE THETA E RIDGE WILL BE ANCHORED ACROSS THE
PANHANDLE...AND A SURFACE TROUGH WILL LINGER IN THIS AREA AS WELL.
ATTM...NOT EXPECTING CONVECTION TO SUSTAIN ITSELF AFTER EVENING...AS
THE LOW LEVEL JET IS WEAK AND FOCUSED IN THE EASTERN PANHANDLE AND
WESTERN COUNTIES.
.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY...THE LATEST LONG RANGE
MODEL SOLUTIONS...ARE TRENDING TOWARD THE DEVELOPMENT OF AN
AMPLIFIED RIDGE ACROSS THE ROCKIES OR CENTRAL PLAINS BEGINNING
EARLY NEXT WEEK. IF THIS CAN COME TO FRUITION...THE CURRENT WET
PATTERN WILL BEGIN TO DRY OUT EARLY NEXT WEEK...AND TEMPERATURES
WILL RETURN TO THE 90S. THE LATEST MEX GUIDANCE IS HINTING AT
WARMER TEMPS TOWARD THE END OF NEXT WEEK AND THIS IS SUPPORTED BY
THE ECMWF AS WELL...AS IT BUILDS A RIDGE ACROSS THE CENTRAL PLAINS
NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1128 PM CDT THU AUG 6 2015
FOG IS BEGINNING TO FORM IN THE PLATTE VALLEY AND REPUBLICAN
VALLEY. THE NAM...RAP AND HRRR SHOW FOG FORMING IN THESE AREAS AND
SPREADING NORTH AND WEST INTO THE SRN SANDHILLS TONIGHT. BURNOFF
IS EXPECTED BY 15Z-16Z. VFR IS EXPECTED THRU 16Z-21Z. THEREAFTER
THUNDERSTORMS SHOULD MOVE INTO WRN NEB...BECOME NUMEROUS...AND
SPREAD SOUTH AND EAST THROUGH THE FCST FRIDAY EVENING.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM FRIDAY EVENING THROUGH LATE FRIDAY NIGHT
FOR NEZ022-035>038-056>059-069>071.
&&
$$
SYNOPSIS...CLB
SHORT TERM...MARTIN
LONG TERM...CLB
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
245 AM PDT FRI AUG 7 2015
.SYNOPSIS...MONSOON MOISTURE IN PLACE ACROSS THE REGION WILL BRING
CONTINUED CHANCES FOR SHOWERS AND THUNDERSTORMS TODAY. THUNDERSTORM
ACTIVITY WILL DECREASE FROM WEST TO EAST TODAY AS DRIER AIR PUSHES
INTO THE REGION FOR THE WEEKEND. ANOTHER ROUND OF MOISTURE MAY BE ON
TAP FOR THE MIDDLE OF NEXT WEEK.
&&
.SHORT TERM...TODAY THROUGH TONIGHT.
SIGNIFICANT MOISTURE HAS OVERSPREAD THE REGION WITH SURFACE
DEWPOINTS RANGING FROM THE UPPER 40`S ACROSS THE SOUTHERN GREAT
BASIN TO NEAR 70 ALONG THE COLORADO RIVER VALLEY NEAR LAKE HAVASU.
IPW SENSORS AND SPC MESOANALYSIS SHOW PRECIPITABLE WATER VALUES OF
1.5 TO NEARLY 2 INCHES ACROSS THE SOUTHEASTERN HALF OF THE FORECAST
AREA WHICH HAS MADE FOR EFFICIENT RAINFALL FROM STORMS OVERNIGHT.
FORTUNATELY STORM MOTION HAS BEEN AND WILL CONTINUE TO BE QUITE
RAPID AND THUS ONLY THE STRONGEST STORMS OR TRAINING STORMS HAVE
POSED A THREAT OF FLASH FLOODING. THE MAIN AREA OF ACTIVITY OVER THE
PAST 6 HOURS HAS BEEN OVER FAR EASTERN SAN BERNARDINO AND THE
SOUTHERN 2/3RDS OF MOHAVE COUNTY ASSOCIATED WITH DIVERGENCE AHEAD OF
AN APPROACHING UPPER LEVEL LOW ACTING ON A MODESTLY UNSTABLE
ATMOSPHERE. TO THE WEST OF THIS...ACTIVITY HAS BEEN MUCH WEAKER WITH
NUMEROUS WEAK SHOWERS AND VERY ISOLATED EMBEDDED THUNDERSTORMS.
VERY CHALLENGING FORECAST OVER THE NEXT 18 HOURS...ESPECIALLY WITH
RESPECT TO PRECIPITATION PLACEMENT. DRYING IS STILL EXPECTED TO
SWEEP FROM WEST TO EAST ACROSS THE REGION TODAY...WITH DRY
CONDITIONS EXPECTED AREA WIDE BY 06Z SATURDAY. HOWEVER...THE LATEST
HIGH-RES GUIDANCE HAS DELAYED DRYING ACROSS THE AREA BY 2-4 HOURS
COMPARED TO THE RUNS FROM YESTERDAY AFTERNOON AND EVENING...THIS MAY
BE IN PART DUE TO THE HIGHER THAN ANTICIPATED MOISTURE LEVELS
CURRENTLY IN PLACE. I HAVE TWEAKED THE FORECAST TO REFLECT THIS
DELAY. FOR INSTANCE...LAST EVENING IT APPEARED THAT THE BEST WINDOW
OF OPPORTUNITY FOR LAS VEGAS WOULD BE BETWEEN 11-16Z. HOWEVER THE
LATEST RUNS OF THE HRRR AND RAP HAVE SHUT MUCH OF THIS ACTIVITY
DOWN...AND HAVE BEGUN TO LATCH ON TO THE IDEA OF DELAYED DRYING. AS
A RESULT...THEY NOW INDICATE DECREASING ACTIVITY (WHICH IS CURRENTLY
BEING NOTED) BETWEEN NOW AND 16Z OR SO AND THEN AN INCREASING TREND
ALONG THE MOISTURE BOUNDARY BETWEEN 16-19Z...WITH THINGS FINALLY
PUSHING EAST OF THE VALLEY BY 22Z OR SO. MY CONFIDENCE IN THIS
SCENARIO IS MODERATE AT BEST...BUT IT DOES FIT WITH THE CURRENT
TRENDS AND OBSERVED MOISTURE IN PLACE AT THIS TIME. IN ANY
CASE...THE GENERAL THREATS WITH STORMS TODAY HAVEN`T CHANGED. THE
FLOOD THREAT WILL BE GREATEST TO THE SOUTH AND EAST OF LAS VEGAS
WHERE THE HIGHEST MOISTURE VALUES RESIDE. TO THE NORTH OF LAS VEGAS
THERE WILL BE AN INCREASED THREAT OF DAMAGING WIND GUSTS AND HAIL
DUE TO STRONG 0-6KM SHEAR AND SOMEWHAT DRIER AND COOLER AIR. IN
FACT...SPC NOW HAS A MARGINAL RISK OF SEVERE STORMS INDICATED ACROSS
THE ESMERALDA...NORTHERN NYE AND LINCOLN COUNTIES ON THEIR DAY 1
OUTLOOK DUE TO THE THREAT OF DAMAGING WINDS AND HAIL.
OUTSIDE OF THE THREAT FROM THUNDERSTORMS...WINDS COULD ALSO BE AN
ISSUE AS DRIER AT PUNCHES INTO THE REGION. THE WIND ADVISORY AND RED
FLAG WARNING IN PLACE FOR SOUTHERN/CENTRAL NYE AND FAR WESTERN CLARK
COUNTIES STILL LOOKS OK...BOTH WILL BE MARGINAL...BUT THE WIND IN
PARTICULAR IS ABNORMAL FOR THIS TIME OF YEAR SO NO CHANGES WILL BE
MADE.
.LONG TERM...SATURDAY THROUGH FRIDAY.
LATEST GUIDANCE IS TRYING TO DEVELOP SOME LIGHT PRECIP ACROSS THE
SIERRA SATURDAY AFTERNOON AND EARLY EVENING. HAVE INCREASED CLOUD
COVER FOR THIS AREA, BUT DID NOT MENTION PRECIP AT THIS TIME. WILL
MONITOR MODEL TRENDS WITH LINGERING MOISTURE IN THAT AREA THE NEXT
12 HOURS OR SO. OTHERWISE, DRY SOUTHWEST FLOW WILL TAKE HOLD THROUGH
MONDAY.
HIGH PRESSURE OVER TEXAS IS STILL ON TRACK TO EXPAND WEST TOWARD NEW
MEXICO STARTING LATE MONDAY. AT THE SAME TIME, A STRONG AREA OF LOW
PRESSURE WILL BUILD ALONG THE NORTHERN CALIFORNIA COAST. THE
COMBINATION OF THESE TWO FEATURES WILL PRODUCE SOUTHERLY FLOW OVER
OUR AREA. MOISTURE WILL TRACK NORTHWARD, MAINLY INTO MOHAVE COUNTY
TUESDAY, WITH SHOWERS AND THUNDERSTORMS POSSIBLE. SOUTHERLY FLOW
SHOULD STICK AROUND THROUGH THURSDAY, MAYBE INTO FRIDAY. MOISTURE
MAY SLIGHTLY EDGE WEST WEDNESDAY AND THURSDAY, BUT THAT WILL DEPEND
ON THE EVENTUAL POSITION OF THE WEST-COAST LOW. WITH PLENTY OF
UNCERTAINTY, DID NOT MAKE MANY CHANGES TO THE CURRENT FORECAST AT
THIS TIME.
AS FOR TEMPERATURES, MONDAY STILL APPEARS TO BE THE WARMEST DAY WITH
TEMPS A DEGREE OR TWO ABOVE NORMAL. OTHERWISE, NORMAL OR SLIGHTLY
BELOW NORMAL TEMPS ARE EXPECTED THROUGHOUT THE LONG-TERM PERIOD.
BREEZY SOUTH TO SOUTHWEST WINDS WILL BE COMMON EACH AFTERNOON AND
EARLY EVENING. WILL HAVE TO MONITOR THE EVENTUAL POSITION AND TRACK
OF THE WEST-COAST LOW AS WE COULD SEE LOCALLY WINDY CONDITIONS
ACROSS OUR NORTHERN FORECAST AREA TUESDAY THROUGH THURSDAY.
&&
.AVIATION...FOR MCCARRAN...LIGHT NORTHEAST WINDS WERE PERSISTING AT
MCCARRAN DUE TO THUNDERSTORM OUTFLOW FROM LAST EVENING. SHOWERS WILL
CONTINUE TO DRIFT ACROSS THE LAS VEGAS VALLEY THROUGH AT LEAST 12Z.
CONFIDENCE IN THUNDERSTORM ACTIVITY BEYOND THIS IS RELATIVELY
LOW...BUT CHANCES WILL EXIST THROUGH ROUGHLY 22Z BEFORE DRIER AIR
PUSHES THROUGH. CIGS AROUND 8K FEET...GUSTY WINDS...HEAVY RAIN WITH
LOWERED VISIBILITY...TURBULENCE AND HAIL WILL ALL BE POSSIBLE WITH
STORMS. SOUTHWEST WINDS ARE EXPECTED TO INCREASE DURING THE
AFTERNOON AND GUSTS TO 25-30 KTS ARE LIKELY. DRIER AND CALMER
CONDITIONS ARE EXPECTED THIS WEEKEND.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...ISOLATED TO SCATTERED THUNDERSTORMS WILL REMAIN
POSSIBLE TODAY...PRIMARILY NORTH AND EAST OF A KNXP-KDRA-KBIH LINE.
THIS LINE WILL PUSH EAST THROUGH THE DAY WITH DRY CONDITIONS
EXPECTED AREA WIDE BY ROUGHLY 06Z SATURDAY. CIGS AROUND 6-8K
FEET...GUSTY WINDS...HEAVY RAIN WITH LOWERED VISIBILITY... STRONG
TURBULENCE AND HAIL WILL ALL BE POSSIBLE WITH STORMS. OUTSIDE OF
THUNDERSTORM ACTIVITY EXPECT GUSTY SOUTHWEST WINDS TO DEVELOP THIS
AFTERNOON WITH SPEEDS OF 15-20 KTS AND GUSTS 25-30 KTS.
&&
.FIRE WEATHER...DRIER AIR WILL PUSH FROM WEST TO EAST ACROSS THE
REGION TODAY. THIS WILL LOWER RH`S TO CRITICAL LEVELS FRIDAY
AFTERNOON AND COMBINE WITH GUSTY WINDS ACROSS MUCH OF CENTRAL AND
SOUTHERN NYE COUNTY TO BRING CRITICAL FIRE CONDITIONS TO THE ZONE
462. IT APPEARS THAT THIS AREA HAS RECEIVED LITTLE PRECIPITATION AND
CURRENT FUEL CONDITIONS WARRANT THE RED FLAG WARNING FOR THIS
AFTERNOON INTO THIS EVENING.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTERS ARE ENCOURAGED TO REPORT
ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING
PROCEDURES.
&&
$$
SHORT TERM/AVIATION...WOLCOTT
LONG TERM.............PADDOCK
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
1217 AM PDT FRI AUG 7 2015
.SYNOPSIS...MONSOON MOISTURE CREEPING INTO THE AREA WILL BRING
INCREASED CHANCES FOR SHOWERS AND THUNDERSTORMS TO THE REGION
OVERNIGHT. THUNDERSTORM ACTIVITY WILL DECREASE RAPIDLY FROM WEST TO
EAST TODAY AS DRIER AIR PUSHES INTO THE REGION FOR THE WEEKEND.
ANOTHER ROUND OF MOISTURE MAY BE ON TAP FOR THE MIDDLE OF NEXT WEEK.
&&
.UPDATE...MADE SOME CHANGES TO THE POP/SKY/WX GRIDS THROUGH 12Z TO
ACCOUNT FOR THE LATEST TRENDS. A SIGNIFICANT UPTICK IN ACTIVITY HAS
BEEN NOTED OVER THE PAST 30-60 MINUTES OVER EASTERN SAN
BERNARDINO...CLARK AND SOUTHERN MOHAVE COUNTIES. HAVE RAISED POPS
AGAIN IN THOSE AREAS AS THIS ACTIVITY IS LIKELY TO PERSIST FOR AT
LEAST THE NEXT COUPLE HOURS OVER THOSE AREAS. THIS ACTIVITY HAS
DEVELOPED IN RESPONSE TO UPPER LEVEL DIVERGENCE ACTING ON A VERY
MOIST (PWATS OF 1.5-2 INCHES) AND MODERATELY UNSTABLE (MUCAPE OF 500-
1000 J/KG) ATMOSPHERE. THIS UNSTABLE AIRMASS IS EXPECTED TO CONTINUE
TO MOVE NORTHWARD THROUGH THE MORNING HOURS. FOR LAS VEGAS...THE
BEST ODDS OF SIGNIFICANT ACTIVITY REMAINS IN THE 11Z-16Z TIMEFRAME.
HOWEVER SHOWERS AND WEAK THUNDERSTORMS ARE ONGOING OVER THE VALLEY
AT THIS TIME...WHICH COULD BLUNT THE POTENTIAL BY THE TIME 11Z ROLLS
AROUND. WILL CONTINUE TO MONITOR THE SITUATION AND UPDATE AS
NECESSARY.
&&
.PREV UPDATE...1055 PM PDT THU AUG 6 2015...QUICK UPDATE TO EXPAND
POPS SOUTH TO THE SOUTHERN SAN BERNARDINO COUNTY BORDER WHERE
CONVECTION WAS STILL ONGOING AS OF 06Z. NO OTHER CHANGES AT THIS
TIME.
&&
.PREV UPDATE...956 PM PDT THU AUG 6 2015...IT`S BEEN A RELATIVELY
ACTIVE EVENING ACROSS PARTS OF THE FORECAST AREA. MOST OF THE
IMPACTFUL ACTIVITY HAS BEEN NEAR THE COLORADO RIVER NEAR THE EAST
END OF LAKE MEAD AND THE WESTERN END OF THE GRAND CANYON WHERE ONE
GAUGE HAS REPORTED 3.62 INCHES OF RAIN THUS FAR.
ADDITIONALLY...SPORADIC AND SEEMINGLY RANDOM GUSTS IN EXCESS OF 58
MPH HAVE BEEN REPORTED WITH ACTIVITY. THIS CONVECTION IS ASSOCIATED
WITH A VORTICITY LOBE THAT WILL CONTINUE TO PUSH NORTHEAST INTO UTAH
OVERNIGHT AND THUS WILL BECOME LESS OF A CONCERN OVER THE NEXT FEW
HOURS.
INSTEAD...FOCUS NOW TURNS TO THE WEST WHERE UPPER LEVEL DYNAMICS
ASSOCIATED WITH AN INCOMING CLOSED LOW WILL HELP TO TRIGGER NEW
CONVECTION FROM NOW THROUGH FRIDAY EVENING. THIS AREA IS RELATIVELY
QUIET AT THE MOMENT AS THE FORCING IS ACTING ON MOISTURE STARVED
AIR. HOWEVER AS IT PUSHES EAST AND ENCOUNTERS THE MOISTURE BOUNDARY
DRAPED ACROSS CENTRAL SAN BERNARDINO...CLARK AND LINCOLN COUNTIES IT
SHOULD BECOME MORE ACTIVE. AN ISOLATED CLUSTER OF STORMS HAS
DEVELOPED OUT AHEAD OF THIS LINE IN RIVERSIDE COUNTY AND WAS MOVING
INTO SAN BERNARDINO COUNTY AS OF 940 PM. POPS HAVE BEEN ADJUSTED TO
BETTER REFLECT THIS THINKING THROUGH FRIDAY. FOR LAS VEGAS...IT
CURRENTLY APPEARS THAT BEST ODDS FOR SHOWER/THUNDERSTORM ACTIVITY
WILL BE BETWEEN ABOUT 4AM AND 9AM AND POPS WERE ADJUSTED UP TO
REFLECT THIS. THE HRRR HAS SHOWN THIS FOR SEVERAL RUNS NOW SO
CONFIDENCE IS INCREASING. SINCE STORM MOTION WILL BE QUITE RAPID (25-
30 MPH)...FLOODING CONCERNS LIE MAINLY WITH TRAINING STORMS...WHICH
IS POSSIBLE DOWNWIND (TO THE NORTHEAST) OF TERRAIN FEATURES. THE
LARGER CONCERN WILL CONTINUE TO BE WITH DAMAGING WIND GUSTS AND TO A
LESSER EXTENT...HAIL. THE RED FLAG WARNING FOR DRY LIGHTNING WAS
CANCELLED SINCE LIGHTNING ACTIVITY HAD ENDED IN THE DRIER AREAS.
WILL CONTINUE TO MONITOR TRENDS OVERNIGHT AND UPDATE AS NECESSARY.
&&
.PREV UPDATE...431 PM PDT THU AUG 6 2015...I DID A QUICK UPDATE TO
TWEAK POPS BASED ON RADAR TRENDS WHERE WE ARE SEEING SHOWERS AND
THUNDERSTORMS. DRY LOW-LEVELS ARE RESULTING IN SPRINKLES TO VERY
LIGHT RAIN TOTALS SO FAR BUT STORMS WITH SURPRISINGLY WEAK RETURNS
ON 0.5 DEGREE RADAR REFLECTIVITY FROM BOTH KEYX AND KESX. DCAPE
VALUES ARE SHOWING A TIGHT GRADIENT OVER WESTERN CLARK AND
WESTERN/CENTRAL SAN BERNARDINO COUNTIES SO THE NORTHWEST PART OF THE
AREA WILL SEE LITTLE THREAT FOR GUSTY WINDS. HOWEVER FROM A
MERCURY/DESERT ROCK TO AMBOY TO LAKE HAVASU LINE ON EAST, GUSTS OF
30-50 MPH OR GREATER ARE POSSIBLE. THUS THE AREA OF GUSTY WINDS WAS
INCREASED IN THE WORDED FORECAST AS A THUNDERSTORM HAZARD. STORMS
SHOULD STILL TRANSITION TO A WETTER TYPE TONIGHT AS LOWER LEVEL
MOISTURE INCREASES.
&&
.PREVIOUS DISCUSSION...
ISSUED AT 205 PM PDT THU AUG 6 2015
.SHORT TERM...TODAY THROUGH FRIDAY NIGHT.
CONVECTION THUS FAR THIS AFTERNOON HAS BEEN CONFINED TO MAINLY
WESTERN SAN BERNARDINO COUNTY WHERE SOME MID LEVEL INSTABILITY IS
FUELING FAST MOVING STORMS ALONG THE LEADING EDGE OF A STRONG UPPER
LEVEL JET. SUB-CLOUD LAYERS IN THIS AREA ARE QUITE DRY WITH SURFACE
DEWPOINTS MAINLY IN THE 30S...SO GUSTY DOWNBURST WINDS ARE A CONCERN
BUT STORMS WILL STRUGGLE TO PRODUCE ANY MEASURABLE RAINFALL. WHILE
THE STORMS HAVE STRUGGLED TO DEPOSIT RAINFALL....THEY HAVE BEEN VERY
EFFICIENT LIGHTNING PRODUCERS WITH OVER 250 CLOUD TO GROUND
LIGHTNING STRIKES SINCE THE NOON HOUR IN WESTERN SAN BERNARDINO
COUNTY. WITH THIS ACTIVITY MOVING NORTHWARD...A RED FLAG WARNING HAS
BEEN POSTED FOR DRY LIGHTNING FOR MUCH OF SAN BERNARDINO COUNTY AND
THE EASTERN HALF OF INYO COUNTY THROUGH LATE TONIGHT.
STILL EXPECTING ATTENTION TO SHIFT FURTHER EAST THIS AFTERNOON AS
MORE ROBUST CONVECTION DEVELOPS ACROSS THE LOWER COLORADO RIVER
VALLEY. CURRENT MESOANALYSIS SHOWS SURFACE BASED INSTABILITY
BUILDING ACROSS THIS AREA WITH CAPE VALUES EXCEEDING 1000 J/KG WITH
LIMITED CAPPING. SEVERAL CONSECUTIVE HRRR RUNS HAVE INSISTED ON
BREAKING THIS AREA OUT IN THE NEXT FEW HOURS. THE POTENTIAL FOR
STRONG AND POTENTIALLY DAMAGING DOWNBURST WINDS IS QUITE HIGH ALONG
THE COLORADO RIVER ROUGHLY FROM BULLHEAD CITY SOUTHWARD TO LAKE
HAVASU...SO THIS AREA WILL BE WATCHED CLOSELY FOR THE POSSIBILITY OF
SEVERE STORMS.
TONIGHT...ACTIVITY ACROSS MOHAVE AND EASTERN SAN BERNARDINO COUNTIES
WILL DRIFT NORTHWARD INTO SOUTHERN NEVADA WHILE ADDITIONAL ACTIVITY
IS LIKELY TO BREAK OUT ACROSS OUR SOUTHERN GREAT BASIN ZONES. WITH
INCREASING SOUTHWESTERLY SHEAR AS A PACIFIC TROUGH APPROACHES...A
FEW BANDS OF PERSISTENT CONVECTION MAY DEVELOP OVERNIGHT WHICH WILL
BE OUR PRIMARY CONCERN FOR ANY FLASH FLOODING. INDIVIDUAL STORM
MOTION WILL BE RATHER SWIFT...BUT TRAINING STORMS WILL POSE A FLOOD
RISK WITH THE HIGH PRECIPITABLE WATER IN PLACE...SO MAINTAINED THE
FLASH FLOOD WATCH TO ACCOUNT FOR THIS FOR MOHAVE AND LINCOLN
COUNTIES. STRONG AND POTENTIALLY DAMAGING WINDS WILL REMAIN
POSSIBLE OVERNIGHT DUE TO STRENGTHENING DEEP LAYER WIND SHEAR AS
WELL AS THE POSSIBILITY OF HAIL WITH THE STRONGER STORMS.
FRIDAY...PACIFIC TROUGH WILL SWEEP EASTWARD ON FRIDAY DRAGGING THE
DEEPER MOISTURE AND INSTABILITY WITH IT. ANTICIPATE ONGOING
CONVECTION AND CLOUD COVER TO BE CONFINED MAINLY TO SOUTHERN NEVADA
AND NORTHWEST ARIZONA IN THE MORNING WHILE SHIFTING EASTWARD THROUGH
THE DAY. BY 5 PM...ANY REMAINING THUNDERSTORM ACTIVITY WILL BE
PRIMARILY CONFINED TO EASTERN MOHAVE COUNTY AND FAR EASTERN AND
NORTHERN LINCOLN COUNTIES. FLASH FLOODING WILL REMAIN A CONCERN WITH
TRAINING STORMS...BUT THE THREAT WILL BE TRANSLATING EASTWARD
THROUGH THE DAY. WITH STRONG SHEAR IN PLACE...SEVERE STORMS WILL BE
A POSSIBILITY AS WELL DEPENDING ON THE DEGREE OF CLOUD COVER AND HOW
MUCH IT INHIBITS DAYTIME HEATING. BY FRIDAY EVENING MOSTLY DRY AND
CLEAR CONDITIONS WILL OVERSPREAD THE ENTIRE REGION.
.LONG TERM...SATURDAY THROUGH THURSDAY.
A DRY SOUTHWEST FLOW WILL BE OVER THE ENTIRE FORECAST AREA SATURDAY
THROUGH MONDAY. HIGH PRESSURE OVER TEXAS WILL EXPAND WEST TOWARD NEW
MEXICO WHILE A TROUGH OF LOW PRESSURE STRETCHES GENERALLY NORTH-
SOUTH ALONG THE WEST COAST STARTING LATE MONDAY. THIS COMBINATION
WILL ALLOW SOUTHERLY FLOW TO DEVELOP WITH MOISTURE TRACKING
NORTHWARD MAINLY INTO MOHAVE COUNTY. WILL CONTINUE THE SHOWER AND
THUNDERSTORM CHANCES FOR THIS AREA TUESDAY. SOUTHERLY FLOW APPEARS
TO STICK AROUND THROUGH THURSDAY, WITH MOISTURE SLIGHTLY EDGING WEST
WEDNESDAY AND PERHAPS LINGERING INTO THURSDAY. THERE REMAINS
UNCERTAINTY IN JUST HOW MUCH MOISTURE WILL ARRIVE AND HOW FAR WEST
IT MAY TRACK. OTHERWISE NEAR NORMAL TEMPS ARE EXPECTED THROUGHOUT
THE LONG-TERM PERIOD. BREEZY SOUTH TO SOUTHWEST WINDS WILL BE COMMON
EACH AFTERNOON AND EARLY EVENING.
&&
.AVIATION...FOR MCCARRAN...OUTFLOW BOUNDARIES HAVE BEEN THE DRIVING
FACTOR FOR CONDITIONS AT MCCARRAN THIS EVENING. THIS IS EXPECTED TO
CONTINUE TO BE THE CASE THROUGH THE OVERNIGHT HOURS. AS OF THIS
WRITING...GUSTY EAST WINDS WERE MOVING INTO THE VALLEY WITH GUSTS 20-
25 KTS EXPECTED. SHOWERS CONTINUE TO DRIFT ACROSS THE REGION AND
MORE VIGOROUS THUNDERSTORMS ARE POSSIBLE DURING THE MORNING HOURS.
AT THIS TIME IT APPEARS THAT THE BEST WINDOW FOR TS WILL BE BETWEEN
11-16Z. CIGS AROUND 8K FEET...GUSTY WINDS...HEAVY RAIN WITH LOWERED
VISIBILITY...STRONG TURBULENCE AND HAIL WILL ALL BE POSSIBLE WITH
STORMS DURING THE MORNING. BY 18Z CONDITIONS SHOULD DRY OUT AND
WINDS WILL BECOME SOUTHWESTERLY AND GUSTY.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...ISOLATED TO SCATTERED THUNDERSTORMS WILL REMAIN
POSSIBLE MAINLY EAST OF A KTPH-KNXP LINE OVERNIGHT AND INTO FRIDAY
MORNING. THIS LINE WILL THEN PUSH EAST THROUGH THE DAY. CIGS AROUND
6-8K FEET...GUSTY WINDS...HEAVY RAIN WITH LOWERED VISIBILITY...
STRONG TURBULENCE AND HAIL WILL ALL BE POSSIBLE WITH STORMS DURING
THE MORNING. OUTSIDE OF THUNDERSTORM ACTIVITY EXPECT GUSTY SOUTHWEST
WINDS FRIDAY OF 15-20 KTS WITH GUSTS 25-30 KTS ACROSS MUCH OF THE
AREA.
&&
.FIRE WEATHER...AS DRIER AIR SWEEPS IN FROM THE SOUTHWEST THROUGH
FRIDAY...THIS WILL HELP TO END THE POTENTIAL FOR SHOWERS AND
THUNDERSTORMS FROM WEST TO EAST. HOWEVER...THIS WILL ALSO HELP TO
INCREASE WINDS FROM THE SOUTH TO SOUTHWEST. RELATIVE HUMIDITY VALUES
AT OR BELOW 15 PERCENT...WIND GUSTS OF 35 MPH OR GREATER AS WELL AS
FUELS BEING DRIED OUT ENOUGH LOOK TO BE MET IN NEVADA ZONE 462 AND
THE FIRE WEATHER WATCH WAS UPGRADED TO A RED FLAG WARNING HERE.
ELSEWHERE, ONLY ONE OR TWO OF THESE CRITERIA LOOK TO BE MET SO NO
HEADLINES WERE ISSUED.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTERS ARE ENCOURAGED TO REPORT
ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING
PROCEDURES.
&&
$$
UPDATES/AVIATION/FIRE WEATHER...WOLCOTT
FIRST UPDATE...STACHELSKI
SHORT TERM...OUTLER
LONG TERM...PADDOCK
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
1055 PM PDT THU AUG 6 2015
.SYNOPSIS...MONSOON MOISTURE CREEPING INTO THE AREA WILL BRING
INCREASED CHANCES FOR SHOWERS AND THUNDERSTORMS TO THE REGION TODAY.
THUNDERSTORM ACTIVITY WILL DECREASE RAPIDLY FROM WEST TO EAST FRIDAY
AS DRIER AIR PUSHES INTO THE REGION FOR THE WEEKEND. ANOTHER ROUND
OF MOISTURE MAY BE ON TAP FOR THE MIDDLE OF NEXT WEEK.
&&
.UPDATE...QUICK UPDATE TO EXPAND POPS SOUTH TO THE SOUTHERN SAN
BERNARDINO COUNTY BORDER WHERE CONVECTION WAS STILL ONGOING AS OF
06Z. NO OTHER CHANGES AT THIS TIME.
&&
.AVIATION...FOR MCCARRAN...OUTFLOW BOUNDARIES HAVE BEEN THE DRIVING
FACTOR FOR CONDITIONS AT MCCARRAN THIS EVENING. THIS IS EXPECTED TO
CONTINUE TO BE THE CASE THROUGH THE OVERNIGHT HOURS. AS OF THIS
WRITING...GUSTY EAST WINDS WERE MOVING INTO THE VALLEY WITH GUSTS 20-
25 KTS EXPECTED. SHOWERS CONTINUE TO DRIFT ACROSS THE REGION AND
MORE VIGOROUS THUNDERSTORMS ARE POSSIBLE DURING THE MORNING HOURS.
AT THIS TIME IT APPEARS THAT THE BEST WINDOW FOR TS WILL BE BETWEEN
11-16Z. CIGS AROUND 8K FEET...GUSTY WINDS...HEAVY RAIN WITH LOWERED
VISIBILITY...STRONG TURBULENCE AND HAIL WILL ALL BE POSSIBLE WITH
STORMS DURING THE MORNING. BY 18Z CONDITIONS SHOULD DRY OUT AND
WINDS WILL BECOME SOUTHWESTERLY AND GUSTY.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...ISOLATED TO SCATTERED THUNDERSTORMS WILL REMAIN
POSSIBLE MAINLY EAST OF A KTPH-KNXP LINE OVERNIGHT AND INTO FRIDAY
MORNING. THIS LINE WILL THEN PUSH EAST THROUGH THE DAY. CIGS AROUND
6-8K FEET...GUSTY WINDS...HEAVY RAIN WITH LOWERED VISIBILITY...
STRONG TURBULENCE AND HAIL WILL ALL BE POSSIBLE WITH STORMS DURING
THE MORNING. OUTSIDE OF THUNDERSTORM ACTIVITY EXPECT GUSTY SOUTHWEST
WINDS FRIDAY OF 15-20 KTS WITH GUSTS 25-30 KTS ACROSS MUCH OF THE
AREA.
&&
.PREV UPDATE...956 PM PDT THU AUG 6 2015...IT`S BEEN A RELATIVELY
ACTIVE EVENING ACROSS PARTS OF THE FORECAST AREA. MOST OF THE
IMPACTFUL ACTIVITY HAS BEEN NEAR THE COLORADO RIVER NEAR THE EAST
END OF LAKE MEAD AND THE WESTERN END OF THE GRAND CANYON WHERE ONE
GAUGE HAS REPORTED 3.62 INCHES OF RAIN THUS FAR.
ADDITIONALLY...SPORADIC AND SEEMINGLY RANDOM GUSTS IN EXCESS OF 58
MPH HAVE BEEN REPORTED WITH ACTIVITY. THIS CONVECTION IS ASSOCIATED
WITH A VORTICITY LOBE THAT WILL CONTINUE TO PUSH NORTHEAST INTO UTAH
OVERNIGHT AND THUS WILL BECOME LESS OF A CONCERN OVER THE NEXT FEW
HOURS.
INSTEAD...FOCUS NOW TURNS TO THE WEST WHERE UPPER LEVEL DYNAMICS
ASSOCIATED WITH AN INCOMING CLOSED LOW WILL HELP TO TRIGGER NEW
CONVECTION FROM NOW THROUGH FRIDAY EVENING. THIS AREA IS RELATIVELY
QUIET AT THE MOMENT AS THE FORCING IS ACTING ON MOISTURE STARVED
AIR. HOWEVER AS IT PUSHES EAST AND ENCOUNTERS THE MOISTURE BOUNDARY
DRAPED ACROSS CENTRAL SAN BERNARDINO...CLARK AND LINCOLN COUNTIES IT
SHOULD BECOME MORE ACTIVE. AN ISOLATED CLUSTER OF STORMS HAS
DEVELOPED OUT AHEAD OF THIS LINE IN RIVERSIDE COUNTY AND WAS MOVING
INTO SAN BERNARDINO COUNTY AS OF 940 PM. POPS HAVE BEEN ADJUSTED TO
BETTER REFLECT THIS THINKING THROUGH FRIDAY. FOR LAS VEGAS...IT
CURRENTLY APPEARS THAT BEST ODDS FOR SHOWER/THUNDERSTORM ACTIVITY
WILL BE BETWEEN ABOUT 4AM AND 9AM AND POPS WERE ADJUSTED UP TO
REFLECT THIS. THE HRRR HAS SHOWN THIS FOR SEVERAL RUNS NOW SO
CONFIDENCE IS INCREASING. SINCE STORM MOTION WILL BE QUITE RAPID (25-
30 MPH)...FLOODING CONCERNS LIE MAINLY WITH TRAINING STORMS...WHICH
IS POSSIBLE DOWNWIND (TO THE NORTHEAST) OF TERRAIN FEATURES. THE
LARGER CONCERN WILL CONTINUE TO BE WITH DAMAGING WIND GUSTS AND TO A
LESSER EXTENT...HAIL. THE RED FLAG WARNING FOR DRY LIGHTNING WAS
CANCELLED SINCE LIGHTNING ACTIVITY HAD ENDED IN THE DRIER AREAS.
WILL CONTINUE TO MONITOR TRENDS OVERNIGHT AND UPDATE AS NECESSARY.
&&
.PREV UPDATE...431 PM PDT THU AUG 6 2015...I DID A QUICK UPDATE TO
TWEAK POPS BASED ON RADAR TRENDS WHERE WE ARE SEEING SHOWERS AND
THUNDERSTORMS. DRY LOW-LEVELS ARE RESULTING IN SPRINKLES TO VERY
LIGHT RAIN TOTALS SO FAR BUT STORMS WITH SURPRISINGLY WEAK RETURNS
ON 0.5 DEGREE RADAR REFLECTIVITY FROM BOTH KEYX AND KESX. DCAPE
VALUES ARE SHOWING A TIGHT GRADIENT OVER WESTERN CLARK AND
WESTERN/CENTRAL SAN BERNARDINO COUNTIES SO THE NORTHWEST PART OF THE
AREA WILL SEE LITTLE THREAT FOR GUSTY WINDS. HOWEVER FROM A
MERCURY/DESERT ROCK TO AMBOY TO LAKE HAVASU LINE ON EAST, GUSTS OF
30-50 MPH OR GREATER ARE POSSIBLE. THUS THE AREA OF GUSTY WINDS WAS
INCREASED IN THE WORDED FORECAST AS A THUNDERSTORM HAZARD. STORMS
SHOULD STILL TRANSITION TO A WETTER TYPE TONIGHT AS LOWER LEVEL
MOISTURE INCREASES.
&&
.PREVIOUS DISCUSSION...
ISSUED AT 205 PM PDT THU AUG 6 2015
.SHORT TERM...TODAY THROUGH FRIDAY NIGHT.
CONVECTION THUS FAR THIS AFTERNOON HAS BEEN CONFINED TO MAINLY
WESTERN SAN BERNARDINO COUNTY WHERE SOME MID LEVEL INSTABILITY IS
FUELING FAST MOVING STORMS ALONG THE LEADING EDGE OF A STRONG UPPER
LEVEL JET. SUB-CLOUD LAYERS IN THIS AREA ARE QUITE DRY WITH SURFACE
DEWPOINTS MAINLY IN THE 30S...SO GUSTY DOWNBURST WINDS ARE A CONCERN
BUT STORMS WILL STRUGGLE TO PRODUCE ANY MEASURABLE RAINFALL. WHILE
THE STORMS HAVE STRUGGLED TO DEPOSIT RAINFALL....THEY HAVE BEEN VERY
EFFICIENT LIGHTNING PRODUCERS WITH OVER 250 CLOUD TO GROUND
LIGHTNING STRIKES SINCE THE NOON HOUR IN WESTERN SAN BERNARDINO
COUNTY. WITH THIS ACTIVITY MOVING NORTHWARD...A RED FLAG WARNING HAS
BEEN POSTED FOR DRY LIGHTNING FOR MUCH OF SAN BERNARDINO COUNTY AND
THE EASTERN HALF OF INYO COUNTY THROUGH LATE TONIGHT.
STILL EXPECTING ATTENTION TO SHIFT FURTHER EAST THIS AFTERNOON AS
MORE ROBUST CONVECTION DEVELOPS ACROSS THE LOWER COLORADO RIVER
VALLEY. CURRENT MESOANALYSIS SHOWS SURFACE BASED INSTABILITY
BUILDING ACROSS THIS AREA WITH CAPE VALUES EXCEEDING 1000 J/KG WITH
LIMITED CAPPING. SEVERAL CONSECUTIVE HRRR RUNS HAVE INSISTED ON
BREAKING THIS AREA OUT IN THE NEXT FEW HOURS. THE POTENTIAL FOR
STRONG AND POTENTIALLY DAMAGING DOWNBURST WINDS IS QUITE HIGH ALONG
THE COLORADO RIVER ROUGHLY FROM BULLHEAD CITY SOUTHWARD TO LAKE
HAVASU...SO THIS AREA WILL BE WATCHED CLOSELY FOR THE POSSIBILITY OF
SEVERE STORMS.
TONIGHT...ACTIVITY ACROSS MOHAVE AND EASTERN SAN BERNARDINO COUNTIES
WILL DRIFT NORTHWARD INTO SOUTHERN NEVADA WHILE ADDITIONAL ACTIVITY
IS LIKELY TO BREAK OUT ACROSS OUR SOUTHERN GREAT BASIN ZONES. WITH
INCREASING SOUTHWESTERLY SHEAR AS A PACIFIC TROUGH APPROACHES...A
FEW BANDS OF PERSISTENT CONVECTION MAY DEVELOP OVERNIGHT WHICH WILL
BE OUR PRIMARY CONCERN FOR ANY FLASH FLOODING. INDIVIDUAL STORM
MOTION WILL BE RATHER SWIFT...BUT TRAINING STORMS WILL POSE A FLOOD
RISK WITH THE HIGH PRECIPITABLE WATER IN PLACE...SO MAINTAINED THE
FLASH FLOOD WATCH TO ACCOUNT FOR THIS FOR MOHAVE AND LINCOLN
COUNTIES. STRONG AND POTENTIALLY DAMAGING WINDS WILL REMAIN
POSSIBLE OVERNIGHT DUE TO STRENGTHENING DEEP LAYER WIND SHEAR AS
WELL AS THE POSSIBILITY OF HAIL WITH THE STRONGER STORMS.
FRIDAY...PACIFIC TROUGH WILL SWEEP EASTWARD ON FRIDAY DRAGGING THE
DEEPER MOISTURE AND INSTABILITY WITH IT. ANTICIPATE ONGOING
CONVECTION AND CLOUD COVER TO BE CONFINED MAINLY TO SOUTHERN NEVADA
AND NORTHWEST ARIZONA IN THE MORNING WHILE SHIFTING EASTWARD THROUGH
THE DAY. BY 5 PM...ANY REMAINING THUNDERSTORM ACTIVITY WILL BE
PRIMARILY CONFINED TO EASTERN MOHAVE COUNTY AND FAR EASTERN AND
NORTHERN LINCOLN COUNTIES. FLASH FLOODING WILL REMAIN A CONCERN WITH
TRAINING STORMS...BUT THE THREAT WILL BE TRANSLATING EASTWARD
THROUGH THE DAY. WITH STRONG SHEAR IN PLACE...SEVERE STORMS WILL BE
A POSSIBILITY AS WELL DEPENDING ON THE DEGREE OF CLOUD COVER AND HOW
MUCH IT INHIBITS DAYTIME HEATING. BY FRIDAY EVENING MOSTLY DRY AND
CLEAR CONDITIONS WILL OVERSPREAD THE ENTIRE REGION.
.LONG TERM...SATURDAY THROUGH THURSDAY.
A DRY SOUTHWEST FLOW WILL BE OVER THE ENTIRE FORECAST AREA SATURDAY
THROUGH MONDAY. HIGH PRESSURE OVER TEXAS WILL EXPAND WEST TOWARD NEW
MEXICO WHILE A TROUGH OF LOW PRESSURE STRETCHES GENERALLY NORTH-
SOUTH ALONG THE WEST COAST STARTING LATE MONDAY. THIS COMBINATION
WILL ALLOW SOUTHERLY FLOW TO DEVELOP WITH MOISTURE TRACKING
NORTHWARD MAINLY INTO MOHAVE COUNTY. WILL CONTINUE THE SHOWER AND
THUNDERSTORM CHANCES FOR THIS AREA TUESDAY. SOUTHERLY FLOW APPEARS
TO STICK AROUND THROUGH THURSDAY, WITH MOISTURE SLIGHTLY EDGING WEST
WEDNESDAY AND PERHAPS LINGERING INTO THURSDAY. THERE REMAINS
UNCERTAINTY IN JUST HOW MUCH MOISTURE WILL ARRIVE AND HOW FAR WEST
IT MAY TRACK. OTHERWISE NEAR NORMAL TEMPS ARE EXPECTED THROUGHOUT
THE LONG-TERM PERIOD. BREEZY SOUTH TO SOUTHWEST WINDS WILL BE COMMON
EACH AFTERNOON AND EARLY EVENING.
&&
.FIRE WEATHER...AS DRIER AIR SWEEPS IN FROM THE SOUTHWEST THROUGH
FRIDAY...THIS WILL HELP TO END THE POTENTIAL FOR SHOWERS AND
THUNDERSTORMS FROM WEST TO EAST. HOWEVER...THIS WILL ALSO HELP TO
INCREASE WINDS FROM THE SOUTH TO SOUTHWEST. RELATIVE HUMIDITY VALUES
AT OR BELOW 15 PERCENT...WIND GUSTS OF 35 MPH OR GREATER AS WELL AS
FUELS BEING DRIED OUT ENOUGH LOOK TO BE MET IN NEVADA ZONE 462 AND
THE FIRE WEATHER WATCH WAS UPGRADED TO A RED FLAG WARNING HERE.
ELSEWHERE, ONLY ONE OR TWO OF THESE CRITERIA LOOK TO BE MET SO NO
HEADLINES WERE ISSUED.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTERS ARE ENCOURAGED TO REPORT
ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING
PROCEDURES.
&&
$$
UPDATE/AVIATION/FIRE WEATHER...WOLCOTT
PREV UPDATE...STACHELSKI
SHORT TERM...OUTLER
LONG TERM...PADDOCK
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
956 PM PDT THU AUG 6 2015
.SYNOPSIS...MONSOON MOISTURE CREEPING INTO THE AREA WILL BRING
INCREASED CHANCES FOR SHOWERS AND THUNDERSTORMS TO THE REGION TODAY.
THUNDERSTORM ACTIVITY WILL DECREASE RAPIDLY FROM WEST TO EAST FRIDAY
AS DRIER AIR PUSHES INTO THE REGION FOR THE WEEKEND. ANOTHER ROUND
OF MOISTURE MAY BE ON TAP FOR THE MIDDLE OF NEXT WEEK.
&&
.UPDATE...IT`S BEEN A RELATIVELY ACTIVE EVENING ACROSS PARTS OF THE
FORECAST AREA. MOST OF THE IMPACTFUL ACTIVITY HAS BEEN NEAR THE
COLORADO RIVER NEAR THE EAST END OF LAKE MEAD AND THE WESTERN END OF
THE GRAND CANYON WHERE ONE GAUGE HAS REPORTED 3.62 INCHES OF RAIN
THUS FAR. ADDITIONALLY...SPORADIC AND SEEMINGLY RANDOM GUSTS IN
EXCESS OF 58 MPH HAVE BEEN REPORTED WITH ACTIVITY. THIS CONVECTION
IS ASSOCIATED WITH A VORTICITY LOBE THAT WILL CONTINUE TO PUSH
NORTHEAST INTO UTAH OVERNIGHT AND THUS WILL BECOME LESS OF A CONCERN
OVER THE NEXT FEW HOURS.
INSTEAD...FOCUS NOW TURNS TO THE WEST WHERE UPPER LEVEL DYNAMICS
ASSOCIATED WITH AN INCOMING CLOSED LOW WILL HELP TO TRIGGER NEW
CONVECTION FROM NOW THROUGH FRIDAY EVENING. THIS AREA IS RELATIVELY
QUIET AT THE MOMENT AS THE FORCING IS ACTING ON MOISTURE STARVED
AIR. HOWEVER AS IT PUSHES EAST AND ENCOUNTERS THE MOISTURE BOUNDARY
DRAPED ACROSS CENTRAL SAN BERNARDINO...CLARK AND LINCOLN COUNTIES IT
SHOULD BECOME MORE ACTIVE. AN ISOLATED CLUSTER OF STORMS HAS
DEVELOPED OUT AHEAD OF THIS LINE IN RIVERSIDE COUNTY AND WAS MOVING
INTO SAN BERNARDINO COUNTY AS OF 940 PM. POPS HAVE BEEN ADJUSTED TO
BETTER REFLECT THIS THINKING THROUGH FRIDAY. FOR LAS VEGAS...IT
CURRENTLY APPEARS THAT BEST ODDS FOR SHOWER/THUNDERSTORM ACTIVITY
WILL BE BETWEEN ABOUT 4AM AND 9AM AND POPS WERE ADJUSTED UP TO
REFLECT THIS. THE HRRR HAS SHOWN THIS FOR SEVERAL RUNS NOW SO
CONFIDENCE IS INCREASING. SINCE STORM MOTION WILL BE QUITE RAPID (25-
30 MPH)...FLOODING CONCERNS LIE MAINLY WITH TRAINING STORMS...WHICH
IS POSSIBLE DOWNWIND (TO THE NORTHEAST) OF TERRAIN FEATURES. THE
LARGER CONCERN WILL CONTINUE TO BE WITH DAMAGING WIND GUSTS AND TO A
LESSER EXTENT...HAIL. THE RED FLAG WARNING FOR DRY LIGHTNING WAS
CANCELLED SINCE LIGHTNING ACTIVITY HAD ENDED IN THE DRIER AREAS.
WILL CONTINUE TO MONITOR TRENDS OVERNIGHT AND UPDATE AS NECESSARY.
&&
.AVIATION...FOR MCCARRAN...OUTFLOW BOUNDARIES HAVE BEEN THE DRIVING
FACTOR FOR CONDITIONS AT MCCARRAN THIS EVENING. THIS IS EXPECTED TO
CONTINUE TO BE THE CASE THROUGH THE OVERNIGHT HOURS. AS OF THIS
WRITING...GUSTY EAST WINDS WERE MOVING INTO THE VALLEY WITH GUSTS 20-
25 KTS EXPECTED. SHOWERS CONTINUE TO DRIFT ACROSS THE REGION AND
MORE VIGOROUS THUNDERSTORMS ARE POSSIBLE DURING THE MORNING HOURS.
AT THIS TIME IT APPEARS THAT THE BEST WINDOW FOR TS WILL BE BETWEEN
11-16Z. CIGS AROUND 8K FEET...GUSTY WINDS...HEAVY RAIN WITH LOWERED
VISIBILITY...STRONG TURBULENCE AND HAIL WILL ALL BE POSSIBLE WITH
STORMS DURING THE MORNING. BY 18Z CONDITIONS SHOULD DRY OUT AND
WINDS WILL BECOME SOUTHWESTERLY AND GUSTY.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...ISOLATED TO SCATTERED THUNDERSTORMS WILL REMAIN
POSSIBLE MAINLY EAST OF A KTPH-KNXP LINE OVERNIGHT AND INTO FRIDAY
MORNING. THIS LINE WILL THEN PUSH EAST THROUGH THE DAY. CIGS AROUND
6-8K FEET...GUSTY WINDS...HEAVY RAIN WITH LOWERED VISIBILITY...
STRONG TURBULENCE AND HAIL WILL ALL BE POSSIBLE WITH STORMS DURING
THE MORNING. OUTSIDE OF THUNDERSTORM ACTIVITY EXPECT GUSTY SOUTHWEST
WINDS FRIDAY OF 15-20 KTS WITH GUSTS 25-30 KTS ACROSS MUCH OF THE
AREA.
&&
.PREV UPDATE...431 PM PDT THU AUG 6 2015...I DID A QUICK UPDATE TO
TWEAK POPS BASED ON RADAR TRENDS WHERE WE ARE SEEING SHOWERS AND
THUNDERSTORMS. DRY LOW-LEVELS ARE RESULTING IN SPRINKLES TO VERY
LIGHT RAIN TOTALS SO FAR BUT STORMS WITH SURPRISINGLY WEAK RETURNS
ON 0.5 DEGREE RADAR REFLECTIVITY FROM BOTH KEYX AND KESX. DCAPE
VALUES ARE SHOWING A TIGHT GRADIENT OVER WESTERN CLARK AND
WESTERN/CENTRAL SAN BERNARDINO COUNTIES SO THE NORTHWEST PART OF THE
AREA WILL SEE LITTLE THREAT FOR GUSTY WINDS. HOWEVER FROM A
MERCURY/DESERT ROCK TO AMBOY TO LAKE HAVASU LINE ON EAST, GUSTS OF
30-50 MPH OR GREATER ARE POSSIBLE. THUS THE AREA OF GUSTY WINDS WAS
INCREASED IN THE WORDED FORECAST AS A THUNDERSTORM HAZARD. STORMS
SHOULD STILL TRANSITION TO A WETTER TYPE TONIGHT AS LOWER LEVEL
MOISTURE INCREASES.
&&
.PREVIOUS DISCUSSION...
ISSUED AT 205 PM PDT THU AUG 6 2015
.SHORT TERM...TODAY THROUGH FRIDAY NIGHT.
CONVECTION THUS FAR THIS AFTERNOON HAS BEEN CONFINED TO MAINLY
WESTERN SAN BERNARDINO COUNTY WHERE SOME MID LEVEL INSTABILITY IS
FUELING FAST MOVING STORMS ALONG THE LEADING EDGE OF A STRONG UPPER
LEVEL JET. SUB-CLOUD LAYERS IN THIS AREA ARE QUITE DRY WITH SURFACE
DEWPOINTS MAINLY IN THE 30S...SO GUSTY DOWNBURST WINDS ARE A CONCERN
BUT STORMS WILL STRUGGLE TO PRODUCE ANY MEASURABLE RAINFALL. WHILE
THE STORMS HAVE STRUGGLED TO DEPOSIT RAINFALL....THEY HAVE BEEN VERY
EFFICIENT LIGHTNING PRODUCERS WITH OVER 250 CLOUD TO GROUND
LIGHTNING STRIKES SINCE THE NOON HOUR IN WESTERN SAN BERNARDINO
COUNTY. WITH THIS ACTIVITY MOVING NORTHWARD...A RED FLAG WARNING HAS
BEEN POSTED FOR DRY LIGHTNING FOR MUCH OF SAN BERNARDINO COUNTY AND
THE EASTERN HALF OF INYO COUNTY THROUGH LATE TONIGHT.
STILL EXPECTING ATTENTION TO SHIFT FURTHER EAST THIS AFTERNOON AS
MORE ROBUST CONVECTION DEVELOPS ACROSS THE LOWER COLORADO RIVER
VALLEY. CURRENT MESOANALYSIS SHOWS SURFACE BASED INSTABILITY
BUILDING ACROSS THIS AREA WITH CAPE VALUES EXCEEDING 1000 J/KG WITH
LIMITED CAPPING. SEVERAL CONSECUTIVE HRRR RUNS HAVE INSISTED ON
BREAKING THIS AREA OUT IN THE NEXT FEW HOURS. THE POTENTIAL FOR
STRONG AND POTENTIALLY DAMAGING DOWNBURST WINDS IS QUITE HIGH ALONG
THE COLORADO RIVER ROUGHLY FROM BULLHEAD CITY SOUTHWARD TO LAKE
HAVASU...SO THIS AREA WILL BE WATCHED CLOSELY FOR THE POSSIBILITY OF
SEVERE STORMS.
TONIGHT...ACTIVITY ACROSS MOHAVE AND EASTERN SAN BERNARDINO COUNTIES
WILL DRIFT NORTHWARD INTO SOUTHERN NEVADA WHILE ADDITIONAL ACTIVITY
IS LIKELY TO BREAK OUT ACROSS OUR SOUTHERN GREAT BASIN ZONES. WITH
INCREASING SOUTHWESTERLY SHEAR AS A PACIFIC TROUGH APPROACHES...A
FEW BANDS OF PERSISTENT CONVECTION MAY DEVELOP OVERNIGHT WHICH WILL
BE OUR PRIMARY CONCERN FOR ANY FLASH FLOODING. INDIVIDUAL STORM
MOTION WILL BE RATHER SWIFT...BUT TRAINING STORMS WILL POSE A FLOOD
RISK WITH THE HIGH PRECIPITABLE WATER IN PLACE...SO MAINTAINED THE
FLASH FLOOD WATCH TO ACCOUNT FOR THIS FOR MOHAVE AND LINCOLN
COUNTIES. STRONG AND POTENTIALLY DAMAGING WINDS WILL REMAIN
POSSIBLE OVERNIGHT DUE TO STRENGTHENING DEEP LAYER WIND SHEAR AS
WELL AS THE POSSIBILITY OF HAIL WITH THE STRONGER STORMS.
FRIDAY...PACIFIC TROUGH WILL SWEEP EASTWARD ON FRIDAY DRAGGING THE
DEEPER MOISTURE AND INSTABILITY WITH IT. ANTICIPATE ONGOING
CONVECTION AND CLOUD COVER TO BE CONFINED MAINLY TO SOUTHERN NEVADA
AND NORTHWEST ARIZONA IN THE MORNING WHILE SHIFTING EASTWARD THROUGH
THE DAY. BY 5 PM...ANY REMAINING THUNDERSTORM ACTIVITY WILL BE
PRIMARILY CONFINED TO EASTERN MOHAVE COUNTY AND FAR EASTERN AND
NORTHERN LINCOLN COUNTIES. FLASH FLOODING WILL REMAIN A CONCERN WITH
TRAINING STORMS...BUT THE THREAT WILL BE TRANSLATING EASTWARD
THROUGH THE DAY. WITH STRONG SHEAR IN PLACE...SEVERE STORMS WILL BE
A POSSIBILITY AS WELL DEPENDING ON THE DEGREE OF CLOUD COVER AND HOW
MUCH IT INHIBITS DAYTIME HEATING. BY FRIDAY EVENING MOSTLY DRY AND
CLEAR CONDITIONS WILL OVERSPREAD THE ENTIRE REGION.
.LONG TERM...SATURDAY THROUGH THURSDAY.
A DRY SOUTHWEST FLOW WILL BE OVER THE ENTIRE FORECAST AREA SATURDAY
THROUGH MONDAY. HIGH PRESSURE OVER TEXAS WILL EXPAND WEST TOWARD NEW
MEXICO WHILE A TROUGH OF LOW PRESSURE STRETCHES GENERALLY NORTH-
SOUTH ALONG THE WEST COAST STARTING LATE MONDAY. THIS COMBINATION
WILL ALLOW SOUTHERLY FLOW TO DEVELOP WITH MOISTURE TRACKING
NORTHWARD MAINLY INTO MOHAVE COUNTY. WILL CONTINUE THE SHOWER AND
THUNDERSTORM CHANCES FOR THIS AREA TUESDAY. SOUTHERLY FLOW APPEARS
TO STICK AROUND THROUGH THURSDAY, WITH MOISTURE SLIGHTLY EDGING WEST
WEDNESDAY AND PERHAPS LINGERING INTO THURSDAY. THERE REMAINS
UNCERTAINTY IN JUST HOW MUCH MOISTURE WILL ARRIVE AND HOW FAR WEST
IT MAY TRACK. OTHERWISE NEAR NORMAL TEMPS ARE EXPECTED THROUGHOUT
THE LONG-TERM PERIOD. BREEZY SOUTH TO SOUTHWEST WINDS WILL BE COMMON
EACH AFTERNOON AND EARLY EVENING.
&&
.FIRE WEATHER...AS DRIER AIR SWEEPS IN FROM THE SOUTHWEST THROUGH
FRIDAY...THIS WILL HELP TO END THE POTENTIAL FOR SHOWERS AND
THUNDERSTORMS FROM WEST TO EAST. HOWEVER...THIS WILL ALSO HELP TO
INCREASE WINDS FROM THE SOUTH TO SOUTHWEST. RELATIVE HUMIDITY VALUES
AT OR BELOW 15 PERCENT...WIND GUSTS OF 35 MPH OR GREATER AS WELL AS
FUELS BEING DRIED OUT ENOUGH LOOK TO BE MET IN NEVADA ZONE 462 AND
THE FIRE WEATHER WATCH WAS UPGRADED TO A RED FLAG WARNING HERE.
ELSEWHERE, ONLY ONE OR TWO OF THESE CRITERIA LOOK TO BE MET SO NO
HEADLINES WERE ISSUED.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTERS ARE ENCOURAGED TO REPORT
ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING
PROCEDURES.
&&
$$
UPDATE/AVIATION/FIRE WEATHER...WOLCOTT
PREV UPDATE...STACHELSKI
SHORT TERM...OUTLER
LONG TERM...PADDOCK
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS BISMARCK ND
351 AM CDT FRI AUG 7 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM CDT FRI AUG 7 2015
FORECAST HIGHLIGHT IN THE SHORT TERM PERIOD IS FOG THIS MORNING.
CURRENTLY...ZONAL FLOW ALOFT WITH DEEP LOW PRESSURE OVER FAR
SOUTH CENTRAL CANADA AND RIDGING OVER THE SOUTHERN AND CENTRAL
PLAINS. BAND OF SHOWERS OVER SOUTHEAST MONTANA STRETCHING EASTWARD
INTO FAR SOUTHWEST NORTH DAKOTA ALONG A COLD FRONTAL BOUNDARY AND
UNDERNEATH AN UPPER JET. HIGH RES MODELS CONTINUE TO BRING THIS
PRECIPITATION INTO MY SOUTHWEST NOW THROUGH 10Z...SPREADING EAST
INTO MY SOUTH CENTRAL COUNTIES THROUGH THE AM HOURS. A FEW
LIGHTNING STRIKES BUT WILL KEEP THUNDER OUT OF THE MORNING
FORECAST WITH LITTLE TO NO CAPE ACROSS SOUTHERN NORTH DAKOTA.
AREAS OF FOG MAINLY OVER NORTHWESTERN...CENTRAL AND EASTERN
PORTIONS OF THE STATE. LATEST HRRR VISIBILITY OUTPUT INDICATES FOG
PERSISTING UNTIL 12-15Z THIS MORNING ACROSS THE AFOREMENTIONED
AREAS. HRRR DOES REMOVE FOG NORTHWEST WHERE WE CURRENTLY HAVE
INCREASING UPPER CLOUDS AND WHERE WINDS WILL SHIFT TO SOUTHWEST
PROMOTING DRY AIR ADVECTION. WITH VISIBILITIES COMING UP AND DOWN
OPTING TO GO WITH A SPECIAL WEATHER STATEMENT FOR NOW HIGHLIGHTING
THE FOG VERSUS HEADLINES.
CHANCES FOR PRECIPITATION WILL CONTINUE TO MOVE EAST ACROSS THE
SOUTH NEAR THE COLD FRONTAL BOUNDARY TODAY INTO THE EVENING HOURS
WHEN FORCING ALOFT WILL BE PRESENT WITH THE UPPER JET. WILL
MENTION THUNDER POTENTIAL IN THE AFTERNOON AND EVENING WHEN
DAYTIME HEATING WILL RESULT IN DIURNAL INSTABILITY. FORCING
DECREASING LATER THIS EVENING SO WENT DRY OVERNIGHT. BREEZY ACROSS
THE NORTH TODAY NEAR THE UPPER LOW...SUB WIND ADVISORY MAGNITUDES.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 322 AM CDT FRI AUG 7 2015
THE MAIN FORECAST FOCUS IS ON THE POTENTIAL FOR PRECIPITATION ALONG
AND SOUTH OF I-94 THIS WEEKEND.
FAR SOUTHERN NORTH DAKOTA AND THE NORTHERN THIRD OF SOUTH DAKOTA ARE
THE CONSENSUS HOT SPOT FOR CONVECTION SATURDAY NIGHT AND
SUNDAY...ACCORDING TO THE 00 UTC GFS/ECMWF/GEFS/GEM GLOBAL
CONSENSUS. THUNDERSTORMS WILL LIKELY MOVE SLOWLY...BUT FLOOD RISK IS
LOW GIVEN LACK OF ANOMALOUS PRECIPITABLE WATER AND RECENT
DEMONSTRATION THAT SOILS CAN HANDLE OVER TWO INCHES PER HOUR WITHOUT
FLASH FLOODING.
IN ITS WAKE...THERE IS GENERAL CONSENSUS AMONG THE 00 UTC
GFS/ECMWF/GEFS/GEM GLOBAL SUITE THAT COMPLEX UPPER LEVEL FLOW WILL
EVOLVE INTO A SIMPLER WEST COAST TROUGH WITH AMPLIFIED RIDGING OVER
THE GREAT PLAINS BY MONDAY MORNING. ASSOCIATED BROAD SCALE
SUBSIDENCE SHOULD BE SUFFICIENT TO SQUELCH CONVECTION UNTIL AT LEAST
WEDNESDAY MORNING. UNCERTAINTY INCREASES THEREAFTER AS SEVERAL
ENSEMBLE MEMBERS EJECT SHORTWAVE ENERGY INTO EASTERN MONTANA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 345 AM CDT FRI AUG 7 2015
AREAS OF FOG ACROSS THE REGION WITH SHORT RANGE MODELS HINTING AT
FOG PERSISTING UNTIL 13-15Z. HAVE ADDED FOG WORDING INTO ALL TAFS
WITH THE EXCEPTION OF KDIK. LIFR-VLIFR CIGS ALSO OCCURRING WITH
THE FOG. VFR FOR THE REMAINDER OF THE PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...NH
LONG TERM...SCHECK
AVIATION...NH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
136 AM CDT FRI AUG 7 2015
.UPDATE...
ISSUED AT 136 AM CDT FRI AUG 7 2015
AREAS OF FOG DEVELOPING ACROSS MUCH OF WESTERN AND CENTRAL NORTH
DAKOTA THIS MORNING. THE EXCEPTION RIGHT NOW APPEARS TO BE THE
SOUTHWEST. A FEW OBSERVATION SITES HAVE COME IN AT A QUARTER MILE
OR LESS NORTHWEST AND AT KJMS. LATEST HRRR VISIBILITY OUTPUT
INDICATES FOG PERSISTING UNTIL 12-15Z THIS MORNING. AS WINDS
BECOME MORE SOUTHWEST ALONG TO SOUTH AND WEST OF THE
MISSOURI RIVER...VISIBILITIES SHOULD IMPROVE FOR THOSE LOCATIONS.
WILL CONTINUE TO MONITOR IN CASE A SPECIAL WEATHER STATEMENT OR
DENSE FOG ADVISORY BECOMES NEEDED.
OTHERWISE A MOSTLY CLEAR SKY AT THE MOMENT. INCREASING CLOUDS
SOUTHWEST AHEAD OF A BAND OF SHOWERS OVER SOUTHEAST MONTANA
STRETCHED ALONG A COLD FRONTAL BOUNDARY AND UNDERNEATH AN UPPER
JET. HIGH RES MODELS BRING THIS PRECIPITATION INTO MY SOUTHWEST
08-10Z...THEN SPREADS/CONTINUES THE LIGHT SHOWERS EAST ACROSS THE
SOUTHWEST INTO THE SOUTH CENTRAL THROUGH THE AM HOURS. KEPT
THUNDER OUT FOR NOW WITH ONLY ONE LIGHTNING STRIKE THE PAST HOUR
OR TWO AND NOT MUCH CAPE TO WORK WITH OVER HERE.
UPDATE ISSUED AT 928 PM CDT THU AUG 6 2015
ISOLATED THUNDERSTORMS FORMING ALONG A COLD FRONT ACROSS
NORTHWEST NORTH DAKOTA IN DIVIDE COUNTY. THIS MAY LAST A FEW
HOURS..AT LEAST THROUGH MIDNIGHT. FOLLOWING THE FRONT INTO
MONTANA THERE APPEARS TO BE SOME SUPPORT FROM THE H300 JET FOR
SOME SHOWERS LATE TONIGHT SOUTHWEST. ADDED SLIGHT CHANCE ALONG THE
NORTHWEST CANADIAN BORDER TONIGHT AND ALONG THE SOUTHWEST SOUTH
DAKOTA BORDER LATE AS WELL. HRRR SUGGESTS SOME PATCHY FOG TONIGHT
CENTRAL AND EAST. ADDED FOG AFTER MIDNIGHT.
UPDATE ISSUED AT 737 PM CDT THU AUG 6 2015
RADAR AND SATELLITE DATA SHOW THE MAIN AREA OF PRECIPITATION IS
EXITING THE REGION. WILL CANCEL THE FLASH FLOOD WATCH. THIS WILL
END THE PRECIPITATION FOR TONIGHT EAST.
COLD FRONT ASSOCIATED WITH THE MAIN LOW LAGS BACK IN EASTERN
MONTANA. WITH LIMITED SUPPORT ALOFT WILL NOT ADD POPS TO THE
SOUTHWEST AT THIS TIME. BUT ACROSS THE NORTHWEST A BAND OF
SHOWERS AND ISOLATED THUNDERSTORMS MAY LINGER THROUGH THE EVENING
ACROSS THE NORTHWEST. WILL WATCH THE HRRR TRENDS FOR THE AFTER
MIDNIGHT PERIOD.
UPDATE ISSUED AT 534 PM CDT THU AUG 6 2015
CANCELED THE FLASH FLOOD WATCH FOR ALL BUT THE JAMES RIVER
VALLEY.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 250 PM CDT THU AUG 6 2015
HEAVY RAINFALL POTENTIAL THROUGH EARLY THIS EVENING SOUTH CENTRAL
AND INTO THE JAMES RIVER VALLEY HIGHLIGHTS THE SHORT TERM
FORECAST.
THE FLASH FLOOD WATCH FOR THE SOUTH CENTRAL AND JAMES RIVER VALLEY
REMAINS IN EFFECT UNTIL 10 PM CDT THIS EVENING. RADAR TRENDS
THROUGH 20 UTC DEPICT NUMEROUS SLOWING MOVING...WARM RAIN PROCESS
DOMINATED STORMS ACROSS THE AFOREMENTIONED AREAS. GIVEN TRENDS IN
THE 17-19 UTC HRRR ITERATIONS WHICH HAVE OVERALL HANDLED THE EVENT
WELL...EXPECT ACTIVITY TO BEGIN TO WANE/PROPAGATE EAST INTO THE
RED RIVER VALLEY BY 23-00 UTC. FURTHER WEST NEAR THE OCCLUDED
FRONTAL BOUNDARY FROM NORTHEAST MONTANA THROUGH LAKE
OAHE...DIURNALLY DRIVEN ISOLATED CONVECTION IS EXPECTED.
HOWEVER...SEVERE WEATHER IS NOT ANTICIPATED.
GIVEN GOOD AGREEMENT ON THE 12 UTC DETERMINISTIC SUITE...A DRY
COLD FRONTAL PASSAGE IS EXPECTED ON FRIDAY...WITH SEASONABLE
TEMPERATURES AND MOSTLY SUNNY SKIES.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 250 PM CDT THU AUG 6 2015
A POTENTIAL WARM UP NEXT WEEK HIGHLIGHTS THE EXTENDED FORECAST.
THE 12 UTC GUIDANCE SUITE IS IN AGREEMENT ON QUASI-ZONAL THIS
WEEKEND AMPLIFYING EARLY NEXT WEEK AS AN INTERMOUNTAIN
WEST/CENTRAL CONUS UPPER LEVEL RIDGE BUILDS. THIS SUPPORTS A
POSSIBLE TRANSITION FROM NEAR NORMAL TEMPERATURES THIS
WEEKEND...WARMING THROUGH NEXT WEEK. GIVEN WEAK WAVES EMBEDDED IN THE
FAST QUASI-ZONAL FLOW THIS WEEKEND...DAILY CHANCES FOR
THUNDERSTORMS ARE FORECAST SATURDAY AND SUNDAY GENERALLY SOUTH OF
ND HIGHWAY 200. SEVERE THUNDERSTORMS ARE NOT EXPECTED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 136 AM CDT FRI AUG 7 2015
AREAS OF FOG DEVELOPING ACROSS THE REGION WITH SHORT RANGE MODELS
HINTING AT FOG PERSISTING UNTIL 13-15Z. HAVE ADDED FOG WORDING
INTO ALL TAFS WITH THE EXCEPTION OF KDIK. LIFR-VLIFR CIGS ALSO
OCCURRING WITH THE FOG.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...NH
SHORT TERM...AYD
LONG TERM...AYD
AVIATION...NH
FORECAST DISCUSSION FOR ROUTINE MORNING FORECAST ISSUANCE
.SYNOPSIS...
ISSUED AT 406 AM CDT FRI AUG 7 2015
MUCH NEEDED RAINFALL EXPECTED FOR MOST OF THE AREA TODAY.
THE POSN OF THE MAIN LARGE-SCALE FEATURES WL CHG LITTLE DURING THE
FCST PERIOD...WITH TROF POSNS NEAR THE COASTS AND RIDGING ACRS
THE CENTRAL PART OF THE CONTINENT. THE MAIN WESTERLIES ACRS THE
NRN CONUS CURRENTLY ARE RATHER LOW-AMPLITUDE...AS A SERIES OF
SHRTWVS IS DISTORTING THE MID-CONUS RIDGE. THE MAIN CHG DURING THE
FCST PERIOD WL BE A MARKED AMPLIFICATION OF THE RIDGE NEXT WEEK.
TEMPS WL NOT VARY TOO MUCH FM SEASONAL NORMALS. THE MAIN
OPPORTUNITIES FOR PCPN WL OCCUR TDA AND DURING THE LATTER PART OF
THE WEEKEND. AFTER TDA/S SYSTEM EXITS THE AREA...PCPN AMNTS WL
PROBABLY BE BLO NORMAL FOR THE REST OF THE PERIOD. &&
.SHORT TERM...TODAY...TONIGHT...AND SATURDAY
ISSUED AT 406 AM CDT FRI AUG 7 2015
FCST FOCUS IS ON SHARS-LIKE SYSTEM CROSSING THE AREA TDA. THE
SYSTEM PRODUCED SIG WX TO OUR W YDA...WITH SEVERAL TORNADOES
APPARENTLY OCCURRING IN MN...AND HVY RAIN IN SOME PLACES AS WELL.
THE SYSTEM IS MOVG OUT OF THE AXIS OF GREATEST MOISTURE AND
INSTABILITY...SO AN EXACT REPEAT IS UNLIKELY ACRS OUR AREA TDA.
STILL...THE SYSTEM WL ACT ON INCRG MOISTURE TO GENERATE FAIRLY
WIDESPREAD SHRA ACRS THE FCST AREA TDA. BASED ON EXTRAP OF RADAR
AND STLT IMAGERY...NEARLY CLOSED UPR SHRTWV WL DRIVE EWD RIGHT
ACRS THE FCST AREA. COMMA-HEAD STRUCTURE WL LIKELY TRACK ACRS
N-C/NE WI...GENERALLY N OF HIGHWAY 29...RESULTING IN A WIDESPREAD
SOAKING RAINFALL ACRS THE N. WIDESPREAD CLDS AND PCPN WL GREATLY
LIMIT DESTABILIZATION...AND SUPPORT ONLY ISOLD THUNDER. BUT WL
NEED TO KEEP A CLOSE WATCH ON THE FAR SRN PART OF THE FCST AREA.
ALTHOUGH UNLIKELY...IF SUFFICIENT BREAKS IN THE CLDS WERE TO
DEVELOP FOR DESTABILIZATION TO OCCUR...CONDITIONS COULD BECOME
FAVORABLE FOR LOW-TOPPED SUPERCELLS.
ADDED HVY RAINFALL ATTRIBUTE TO THE GRIDS...NOT BECAUSE OF THE
POTENTIAL FOR TORRENTIAL RAINS WITH TSTMS...BUT MORE FOR EFFICIENT
SHRA/TSRA THAT COULD PERSIST FOR SEVERAL HRS AS THE COMMA HEAD
STRUCTURE PUSHES ACRS THE AREA. SOME RUNS OF THE HRRR PRODUCED
RAINFALLS OF UP TO 3.5 INCHES ACRS PORTIONS OF THE FCST AREA. A
WIDESPREAD 1-2 INCH RAINFALL ACRS THE N SEEMS MORE LIKELY...WITH A
FEW LOCATIONS POSSIBLY EXCEEDING 2 INCHES. THE DURATION OF THE
RAINFALL SEEMS TO FAVOR MAINLY PONDING OF WATER IN LOW-LYING AREAS
RATHER THAN FLASH FLOODING. WL DETAIL SITN IN THE HWO.
TIMING THE ENDING OF THE PCPN WAS DIFFICULT. BACK EDGE OF PCPN WAS
STILL MAKING STEADY EWD PROGRESS EARLY THIS MORNING...AND PURE
EXTRAPOLATION WOULD TAKE IT OUT OF THE ARE MUCH FASTER THAN
DEPICTED ON THE MODELS. SUSPECT SYSTEM WL SLOW A BIT AS UPR
SPEED MAX BECOMES SITUATED MORE ON THE UPSTREAM SIDE OF THE
TROF...AND SOME ADDITIONAL PCPN DEVELOPMENT WL EVENTUALLY OCCUR
ALONG THE TRAILING EDGE OF THE SYSTEM. BUILT POP GRIDS WITH
CATEGORICAL POPS SHIFTG THROUGH THE N DURING THE DAY...BUT
LINGERED SCT/ISOLD POPS BACK TO THE SW WELL INTO TNGT. TEMPS TDA
NOT LIKELY TO RISE VERY FAR WITH WIDESPREAD CLDS AND PCPN.
EXPECT SOME FOG TO DEVELOP OVERNIGHT. THERE COULD ALSO BE QUITE A
BIT OF LINGERING LOW CLD COVER. IF BREAKS IN THE LOW CLDS ARE MORE
SIG THAN EXPECTED...DENSE FOG COULD BECOME A PROBLEM.
QUIET WX EXPECTED SAT AS THE NEXT SYSTEM WL FIRST BE APPROACHING
FM THE W. SLOWED THE ARRIVAL OF THE POPS WITH THAT SYSTEM FM WHAT
WAS IN PREV FCST.
.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY
ISSUED AT 406 AM CDT FRI AUG 7 2015
A PATTERN SHIFT IS EXPECTED BY EARLY NEXT WEEK AS 500MB RIDGE
BUILDS ACROSS THE ROCKIES AND TROUGH DEEPENS ACROSS EASTERN
CANADA. THIS WILL LEAVE THE REGION IN A NORTHWEST FLOW PATTERN.
TEMPERATURES WILL TREND TOWARDS BELOW NORMAL READINGS BY THE
MIDDLE OF NEXT WEEK BEFORE REBOUNDING LATE IN THE WEEK AHEAD
OF A COLD FRONT.
MAIN CONCERN WILL BE THE TIMING OF PRECIPITATION CHANCES SATURDAY
NIGHT INTO SUNDAY NIGHT AS A COLD FRONT MOVES THROUGH THE AREA.
MODELS IN BETTER AGREEMENT WITH TIMING OF PRECIPITATION. CHANCES
FOR SHOWERS AND STORMS WILL INCREASE LATER SATURDAY NIGHT...WITH
THE BEST CHANCE FOR SHOWERS AND STORMS SUNDAY INTO SUNDAY EVENING
AS FRONT MOVES THROUGH THE REGION. MAIN CONCERN WILL THE
POSSIBILITY OF LOCALLY HEAVY RAIN. ENOUGH LINGERING MOISTURE AND
WEAK DISTURBANCE MOVING ACROSS THE REGION ON MONDAY COULD TRIGGER
AN ISOLATED SHOWER OR STORM ACROSS NORTHEAST OR EAST-CENTRAL
WISCONSIN. ANOTHER DISTURBANCE DROPPING SOUTHEAST OUT OF CANADA
NEEDS TO BE WATCHED FOR TUESDAY INTO TUESDAY AFTERNOON. LATEST
ECMWF DOES DEPICT PRECIPITATION DURING THIS PERIOD. WILL WAIT
FOR A FEW MORE MODEL RUNS TO SEE IF THIS SCENARIO IS STILL
DEPICTED BEFORE ADDING A CHANCE OF PRECIPITATION DURING THIS
PERIOD. OTHERWISE...DRY CONDITIONS WILL PREVAIL THROUGH THURSDAY.
&&
.AVIATION...FOR 12Z TAF ISSUANCE
ISSUED AT 406 AM CDT FRI AUG 7 2015
FLIGHT CONDITIONS EXPECTED TO DETERIORATE TDA...AND WL PROBABLY
REMAIN POOR TNGT. PREV TAF SET BROUGHT CONDITIONS DOWN TO LOWER-
END MVFR AND IFR CONDITIONS BY MIDNIGHT SAT. PLAN TO CONT THAT
WITH THE 12Z ISSUANCE AS THE POOR FLIGHT CONDITIONS WL TAKE UNTIL
AT LEAST SAT MORNING TO IMPROVE.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS.......SKOWRONSKI
SHORT TERM.....SKOWRONSKI
LONG TERM......ECKBERG
AVIATION.......SKOWRONSKI
THERE IS NOT A LOT TO ADD FROM THE PREVIOUS FORECAST DISCUSSION. A
RATHER ANOMALOUS DEEP WESTERLY FLOW PATTERN IS IN PLACE BUT THE
MORNING SOUNDINGS SHOW AVERAGE DEEP MOISTURE AND LAPSE RATES.
HOWEVER...PRE FRONTAL MOISTURE IS HIGHER TO OUR NORTH AND THE FRONTAL
TROUGH WILL DROP SLOWLY THROUGH GEORGIA...SO AT LEAST OUR NORTHERN
HALF WILL SEE AROUND A QUARTER OF AN INCH INCREASE IN PRECIPITABLE
WATER. THIS IS ALREADY INDICATED BY SOME SHOWERS SPREADING WELL INLAND
FROM THE GULF.
THE EARLY MORNING HRRR AND LOCAL WRF MODELS SHOWED AFTERNOON
CONVECTION FORMING OVER NORTH FLORIDA AND ZIPPING EAST/SOUTHEAST...
MOVING OFFSHORE JUST TO OUR NORTH. WOULD EXPECT THAT SOME CELLS
COULD CLIP OUR NORTHERN SECTIONS OR SEND DOWN AN OUTFLOW BOUNDARY
THAT GENERATES NEW CONVECTION.
THE MESOSCALE MODELS ALSO SHOWED AN AREA OF CONVECTION DEVELOPING
ALONG THE SPACE/TREASURE COAST THIS AFTERNOON...PROBABLY AS WEST
COAST BOUNDARY MOVES ACROSS AND INTERACTS WITH THE LAKE OKEECHOBEE
BOUNDARY.
THE CURRENT AND PROGGED LOW LEVEL WINDS WILL BE STRONGER THAN NORMAL
WITH 925 MB WINDS AROUND 25 KNOTS ACROSS THE NORTH HALF.
THEREFORE...CELLS THIS AFTERNOON WILL PRODUCE STRONG WIND GUSTS AND
MARINERS WILL NEED TO BE PARTICULARLY AWARE OF THIS.
AN OVERALL SCATTERED COVERAGE SEEMS REASONABLE WITH THE HIGHEST
VALUES IN THE NORTH...SO NOT PLANNING MUCH CHANGE TO THE CURRENT
FORECAST.
&&
.AVIATION...
PRE FRONTAL MOISTENING WILL OCCUR ACROSS THE NORTH AND IS PROBABLY
ALREADY INDICATED BY SOME MORNING MVFR STRATUS THERE. EVEN THOUGH
THE EARLY MORNING MESOSCALE MODELS DID NOT PROJECT GULF SHOWERS TO
SPREAD INLAND...SOME ARE ALREADY APPROACHING THE NORTHERN
TERMINALS. WITH THE STRONGER THAN NORMAL WINDS IN THE LOWER LEVELS...
WIND GUSTS 30-40 KNOTS ARE EXPECTED MAINLY WITH THE AFTERNOON
SHOWERS/STORMS.
&&
.MARINE...(NO CHANGE TO PREVIOUS DISCUSSION)
TODAY...LOW LEVEL RIDGE AXIS HAS DROPPED BACK ACROSS SOUTH FL SO
THERE WILL BE A STRONGER OFFSHORE (W/SW) FLOW WITH WIND SPEEDS UP TO
15 KNOTS. IN ADDITION TO PRODUCING SOME CHOPPY SEAS OVER THE OPEN
ATLC...THE FASTER STORM MOTION WILL PRODUCE A THREAT FOR STRONG WIND
GUSTS AS THEY CROSS THE INTRACOASTAL AND ONTO THE NEARSHORE ATLC.
BOATERS SHOULD BE PREPARED FOR A COUPLE/FEW SPECIAL MARINE WARNINGS
THIS AFTN.
TONIGHT...EXPECT A CAUTION HEADLINE FOR THE OFFSHORE VOLUSIA AND
BREVARD WATERS FOR 15-20 KNOTS AS LOW PRESSURE PUSHES OFF THE
CAROLINA COAST AND PRES GRAD TIGHTENS.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
FORECASTS...LASCODY
IMPACT WX...SEDLOCK
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
633 AM EDT FRI AUG 7 2015
.SYNOPSIS...
AN UPPER TROUGH AND ASSOCIATED FRONTAL BOUNDARY WILL MOVE EAST OF
THE FORECAST AREA BY TONIGHT. DRIER AIR WILL RETURN FOR THE
WEEKEND. ANOTHER FRONT MAY AFFECT THE REGION BY THE MIDDLE OF NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SCATTERED SHOWERS CONTINUE OVER PORTIONS OF THE EASTERN AND
SOUTHERN MIDLANDS THIS MORNING AHEAD OF SHORT WAVE ENERGY IN THE
WESTERN CAROLINAS. LATEST HRRR INDICATING THAT MOST OF THE
PRECIPITATION WILL END BY AROUND 13Z...ALTHOUGH SOME LATER
DEVELOPMENT WILL BE POSSIBLE ESPECIALLY DURING THE AFTERNOON AS A
FRONTAL BOUNDARY PUSHES THROUGH THE AREA. HOWEVER...WITH THE SHORT
WAVE ENERGY MOVING EASTWARD...THE BEST CHANCE FOR PRECIPITATION
WILL BE MAINLY THIS MORNING. AFTERNOON HIGH TEMPERATURES WILL BE
GENERALLY IN THE UPPER 80S NORTH TO AROUND 90 DEGREES ELSEWHERE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
DRIER ATMOSPHERE FOR SATURDAY AS WEAK HIGH PRESSURE BUILDS IN FROM
THE WEST. WEAK COOL ADVECTION BEHIND THE FRONT AND DEPARTING LOW
EXPECTED TO KEEP TEMPS DOWN TO NEAR CLIMATOLOGY SATURDAY.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
NO CHANGES TO THE EXTENDED FORECAST AT THIS TIME. MODELS INDICATE
UPPER RIDGE WILL SHIFT BACK TO THE WEST SOME...WITH UPPER TROUGH
DEEPENING OVER THE E CONUS...EARLY TO MID NEXT WEEK. THIS ALONG
WITH SOME EXPECTED INCREASE IN MOISTURE AND INDICATIONS OF A
POSSIBLE FRONT SUGGESTS TREND TOWARDS INCREASING POPS. GENERALLY
ACCEPTED BLEND OF GUIDANCE.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
UPPER TROUGH AXIS IS CROSSING THE AREA THIS MORNING AND THE SHOWERS
ASSOCIATED WITH IT ARE SHIFTING NORTH AND EAST OF THE TERMINALS.
WIDESPREAD MVFR CIGS ASSOCIATED WITH THE PASSING UPPER TROUGH WILL
LINGER THROUGH MID MORNING BEFORE VFR CIGS RETURN BY 15Z. ISOLATED
TO SCATTERED SHOWERS AND AN ISOLATED THUNDERSTORM POSSIBLE TODAY BUT
CONFIDENCE IS LOW AS DRIER AIR MOVES IN FROM THE WEST AND THEREFORE
NO MENTION OF STORMS IN THE FORECAST. WINDS WILL PICK UP FROM THE
WEST AROUND 10 KNOTS AFTER 15Z THEN A WEAK COLD FRONT WILL CROSS THE
REGION AND WINDS WILL SHIFT TO THE NORTHWEST.
EXTENDED AVIATION OUTLOOK...NO WIDESPREAD RESTRICTIONS TO
AVIATION EXPECTED THROUGH MONDAY. SHOWERS AND THUNDERSTORMS
POSSIBLE TUESDAY AS A COLD FRONT CROSSES THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
99
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
907 AM CDT FRI AUG 7 2015
.SHORT TERM...
349 AM CDT
THROUGH SUNDAY...
CONCERNS REVOLVE AROUND PRECIPITATION CHANCES EACH OF THE NEXT FEW
DAYS.
A COMPACT BUT POTENT UPPER LEVEL DISTURBANCE IN MN IS PRODUCING A
COMPLEX OF THUNDERSTORMS NOW MOVING INTO WESTERN WISCONSIN. THERE IS
A WEAK SURFACE REFLECTION WITH THIS FEATURE WHERE THE MORE ORGANIZED
ACTIVITY IS ONGOING. CLOSER TO HOME...SURFACE HIGH PRESSURE IS
HOLDING FIRM JUST NEAR LAKE HURON...WITH THE RIDGE AXIS ORIENTED
SOUTHWESTWARD. IR IMAGERY EARLY THIS MORNING HAS SHOWN A CONTINUAL
EROSION OF THE DEEPER CLOUDS ON THE SOUTHERN END OF THIS COMPLEX AS
IT MOVES INTO DRIER AIR FARTHER SOUTH AND EAST.
AN UPPER LEVEL JET MOVING INTO THE NORTHERN PLAINS WILL ALLOW THIS
UPPER DISTURBANCE TO MOVE SOUTH AND EAST TOWARD THE AREA
TODAY...EVEN OUTRUNNING THE SURFACE LOW. MUCH OF THE NEAR TERM
GUIDANCE KEEPS ERODING PRECIP SOUTH OF THE WISCONSIN BORDER AHEAD OF
THIS SYSTEM. THE EXCEPTION TO THIS THE EXPERIMENTAL HRRR AND
SEVERAL HOP-WRF MEMBERS WHICH ARE A BIT MORE AGGRESSIVE WITH
DRIVING PRECIP THROUGH THE AREA...ESPECIALLY THIS AFTERNOON.
OBSERVATIONS SUGGEST SOME CONTINUED DEVELOPMENT SOUTHWARD THROUGH
THE MORNING INTO THE INSTABILITY AXIS WHICH WILL GRADUALLY
APPROACH FROM THE WEST TODAY. HAVE STILL KEPT POPS ON THE LOWER
SIDE AWAY FROM NORTH CENTRAL ILLINOIS AND POINTS WEST...THOUGH
EXPECT OUR NORTHWESTERN ZONES INTO WINNEBAGO/BOONE/MCHENRY
COUNTIES STAND A CHANCE OF SOME SHOWERS OR A STRAY STORM LATER
THIS MORNING INTO THE AFTERNOON. CONTINUED DRY AIR SHOULD FURTHER
ERODE AT THE PRECIP...THOUGH AS THE DAY GOES ON AND THE
INSTABILITY AXIS SHIFTS EASTWARD WITH THE UPPER LOW...EXPECT THAT
SOME SHOWERS WILL BE POSSIBLE. SOUNDINGS ARE NOT THRILLED ABOUT
THE THUNDER POTENTIAL CLOSER TO CHICAGO WITH CAPPING HOLDING.
TONIGHT...THE UPPER LOW SHIFTS EAST AND OUTPACES THE SURFACE LOW AND
THUS EXPECT SOME DECREASE IN COVERAGE OF SHOWERS AND COULD JUST BE
DRY...THOUGH WILL HANG ONTO A LOW POP MENTION OVERNIGHT FOR SOME
LINGERING LOW LEVEL CONVERGENCE.
SATURDAY...FOCUS SHIFTS TO ENERGY PROPAGATING FROM THE TROUGH OFF
THE CA COAST THIS MORNING. THIS IS FORECAST TO RIDE A DECENT UPPER
JET THROUGH THE PLAINS OVERNIGHT INTO THE MORNING AND ALONG THE
NORTHERN FRINGES OF THE UPPER LEVEL RIDGE AXIS THAT EXTENDS FROM
TEXAS NORTH INTO THE CENTRAL PLAINS. THIS WAVE CRUISES THROUGH
SATURDAY MORNING WITH SURFACE HIGH PRESSURE IN PLACE AND A LACK OF
DEEPER MOISTURE...SO HAVE CONTINUED A DRY FORECAST...AND THAT GOES
FOR SATURDAY AFTERNOON AS WELL AS THE WAVE MOVES EAST. WILL HAVE
TO WATCH THE MORNING PERIOD IF THE LOWER LEVELS MOISTEN UP A BIT
MORE THAN FORECAST THAT A STRAY SHOWER OR STORM WOULD BE POSSIBLE.
THE NAM IS A LITTLE SLOWER WITH THIS WAVE...BUT STILL DRY IN THE
AFTERNOON AS THE STRONGER FORCING REMAINS TO OUR WEST.
CHANCES FOR SHOWERS AND STORMS INCREASE SATURDAY NIGHT INTO SUNDAY
MORNING AS WE GET A BETTER CO-LOCATION OF DEEPER MOISTURE TRANSPORT
COURTESY OF A DECENT LOW LEVEL JET...ANOTHER PACIFIC
DISTURBANCE...AND PWATS APPROACHING 2 INCHES. WE HANG ONTO SE FLOW
AT THE SURFACE FARTHER EAST...WHICH WOULD THEN GIVE THE HIGHER
CONCERN FOR MODERATE TO HEAVY PRECIP RATES SOUTH AND WEST. THERE
IS A SEVERE THREAT GIVEN THE MODEST WESTERLY FLOW NORTH OF THE
RIDGE AND HIGHER DEWPOINTS ADVECTING IN...BUT DESTABILIZATION
CONCERNS EXIST AT THIS POINT IN TIME TO NAIL DOWN THE SPECIFICS
YET. THE MARGINAL RISK IS FOCUSED IN OUR SOUTHWEST AT THIS TIME.
KMD
&&
.LONG TERM...
407 AM CDT
SUNDAY NIGHT THROUGH THURSDAY...
.LONG TERM...
AN UPPER LEVEL LOW QUICKLY MOVES EASTWARD THROUGH SOUTHERN ONTARIO SUNDAY
NIGHT INTO MONDAY...AS THIS OCCURS AND A DEEP TROUGH BUILDS ALONG
THE PACIFIC COAST...UPPER LEVEL RIDGING IN THE WEST WILL CONTINUE
TO AMPLIFY THE FLOW PATTERN. NW FLOW ON MONDAY WILL KEEP A CHANCE
FOR SHOWERS AND STORMS AROUND AS A WEAK COLD FRONT MOVES THROUGH.
ANOTHER DISTURBANCE GLIDES BY TO OUR NORTH TUESDAY FOR A SOMEWHAT
COOLER THOUGH GENERALLY DRY DAY. A STRAY SHOWER IS POSSIBLE. HIGH
PRESSURE BUILDS IN FOR MID WEEK.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* LAKE BREEZE TO EAST/SOUTHEAST WINDS THIS AFTERNOON.
* SLIGHT CHANCE OF SHOWERS THIS AFTERNOON INTO THE EVENING.
MM
//DISCUSSION...UPDATED 12Z...
VFR CONDITIONS PERSISTING THIS MORNING WHILE SOUTH/SOUTHEAST
WINDS STEADILY INCREASE. VFR CONDITIONS ARE STILL EXPECTED FOR
MOST OF THE FORECAST PERIOD. HOWEVER...THE POTENTIAL FOR SCATTERED
SHOWERS IS INCREASING AND BECOMING SOONER THAN PREVIOUSLY
EXPECTED. ALTHOUGH THE HIGHEST CHANCES FOR PRECIP WILL STAY TO
THE NORTH...AT LEAST SCATTERED DEVELOPMENT IS NOW POSSIBLE THIS
AFTERNOON INTO THE EARLY EVENING. INSTABILITY DOES NOT APPEAR TO
BE THE GREATEST...AND SO THINK THE LIKELIHOOD OF THUNDER IS LOW AT
THIS TIME. LAKE BREEZE PUSH IS STILL APPEARING TO BE LIKELY THIS
AFTERNOON...WITH EAST SOUTHEAST WINDS AT OR ABOVE 10KT EXPECTED
LATER THIS AFTERNOON.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* MEDIUM CONFIDENCE FOR WINDS/LAKE BREEZE TODAY.
* MEDIUM CONFIDENCE FOR ISOLATED SHOWERS.
MM
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...SLIGHT CHANCE OF THUNDERSTORMS.
SUNDAY...CHANCE OF THUNDERSTORMS.
MONDAY...CHANCE OF THUNDERSTORMS.
TUESDAY...VFR.
WEDNESDAY...VFR.
THURSDAY...VFR.
RODRIGUEZ
&&
.MARINE...
302 AM CDT
LIGHTER EASTERLY WINDS IN PLACE EARLY THIS MORNING WILL OBSERVE A
STEADY INCREASE TODAY WHILE SHIFTING TO MORE OF A SOUTHERLY
COMPONENT...AS LOW PRESSURE TO THE WEST OVER THE NORTHERN PLAINS
SLOWLY PUSHES EAST. STILL THINK A 10 TO 20 KT WIND WILL BE THE
HIGHEST TODAY...BUT SOME GUIDANCE IS HINTING AT POSSIBLE HIGHER
SPEEDS THROUGHOUT THE DAY. ALTHOUGH I DID INCREASE SPEEDS...DID
NOT GO AS HIGH. HOWEVER...DID MENTION A FEW GUSTS TO 25KT FOR THE
OPEN WATERS TODAY. IT DOES LOOK LIKE A BETTER WINDOW FOR STRONGER
WINDS OF 15 TO 25 KT ACROSS THE NORTH TONIGHT INTO SATURDAY
MORNING...AND HAVE TRENDED THAT WAY WITH THE FORECAST. THIS WILL
BE IN RESPONSE TO THE APPROACHING LOW...BUT WITH IT
WEAKENING...SPEEDS WILL DIMINISH SATURDAY INTO SATURDAY NIGHT.
EXACT TIMING AND PLACEMENT OF THE NEXT SYSTEM LATE IN THE WEEKEND
IS STILL UNCERTAIN BUT IT DOES APPEAR TO BE ANOTHER PERIOD WHEN
SPEEDS WILL ONCE AGAIN INCREASE...AT LEAST FOR THE SOUTHERN HALF
OF THE LAKE.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
642 AM CDT FRI AUG 7 2015
.SHORT TERM...
349 AM CDT
THROUGH SUNDAY...
CONCERNS REVOLVE AROUND PRECIPITATION CHANCES EACH OF THE NEXT FEW
DAYS.
A COMPACT BUT POTENT UPPER LEVEL DISTURBANCE IN MN IS PRODUCING A
COMPLEX OF THUNDERSTORMS NOW MOVING INTO WESTERN WISCONSIN. THERE IS
A WEAK SURFACE REFLECTION WITH THIS FEATURE WHERE THE MORE ORGANIZED
ACTIVITY IS ONGOING. CLOSER TO HOME...SURFACE HIGH PRESSURE IS
HOLDING FIRM JUST NEAR LAKE HURON...WITH THE RIDGE AXIS ORIENTED
SOUTHWESTWARD. IR IMAGERY EARLY THIS MORNING HAS SHOWN A CONTINUAL
EROSION OF THE DEEPER CLOUDS ON THE SOUTHERN END OF THIS COMPLEX AS
IT MOVES INTO DRIER AIR FARTHER SOUTH AND EAST.
AN UPPER LEVEL JET MOVING INTO THE NORTHERN PLAINS WILL ALLOW THIS
UPPER DISTURBANCE TO MOVE SOUTH AND EAST TOWARD THE AREA
TODAY...EVEN OUTRUNNING THE SURFACE LOW. MUCH OF THE NEAR TERM
GUIDANCE KEEPS ERODING PRECIP SOUTH OF THE WISCONSIN BORDER AHEAD OF
THIS SYSTEM. THE EXCEPTION TO THIS THE EXPERIMENTAL HRRR AND
SEVERAL HOP-WRF MEMBERS WHICH ARE A BIT MORE AGGRESSIVE WITH
DRIVING PRECIP THROUGH THE AREA...ESPEICALLY THIS AFTERNOON.
OBSERVATIONS SUGGEST SOME CONTINUED DEVELOPMENT SOUTHWARD THROUGH
THE MORNING INTO THE INSTABILITY AXIS WHICH WILL GRADUALLY
APPROACH FROM THE WEST TODAY. HAVE STILL KEPT POPS ON THE LOWER
SIDE AWAY FROM NORTH CENTRAL ILLINOIS AND POINTS WEST...THOUGH
EXPECT OUR NORTHWESTERN ZONES INTO WINNEBAGO/BOONE/MCHENRY
COUNTIES STAND A CHANCE OF SOME SHOWERS OR A STRAY STORM LATER
THIS MORNING INTO THE AFTERNOON. CONTINUED DRY AIR SHOULD FURTHER
ERODE AT THE PRECIP...THOUGH AS THE DAY GOES ON AND THE
INSTABILITY AXIS SHIFTS EASTWARD WITH THE UPPER LOW...EXPECT THAT
SOME SHOWERS WILL BE POSSIBLE. SOUNDINGS ARE NOT THRILLED ABOUT
THE THUNDER POTENTIAL CLOSER TO CHICAGO WITH CAPPING HOLDING.
TONIGHT...THE UPPER LOW SHIFTS EAST AND OUTPACES THE SURFACE LOW AND
THUS EXPECT SOME DECREASE IN COVERAGE OF SHOWERS AND COULD JUST BE
DRY...THOUGH WILL HANG ONTO A LOW POP MENTION OVERNIGHT FOR SOME
LINGERING LOW LEVEL CONVERGENCE.
SATURDAY...FOCUS SHIFTS TO ENERGY PROPAGATING FROM THE TROUGH OFF
THE CA COAST THIS MORNING. THIS IS FORECAST TO RIDE A DECENT UPPER
JET THROUGH THE PLAINS OVERNIGHT INTO THE MORNING AND ALONG THE
NORTHERN FRINGES OF THE UPPER LEVEL RIDGE AXIS THAT EXTENDS FROM
TEXAS NORTH INTO THE CENTRAL PLAINS. THIS WAVE CRUISES THROUGH
SATURDAY MORNING WITH SURFACE HIGH PRESSURE IN PLACE AND A LACK OF
DEEPER MOISTURE...SO HAVE CONTINUED A DRY FORECAST...AND THAT GOES
FOR SATURDAY AFTERNOON AS WELL AS THE WAVE MOVES EAST. WILL HAVE
TO WATCH THE MORNING PERIOD IF THE LOWER LEVELS MOISTEN UP A BIT
MORE THAN FORECAST THAT A STRAY SHOWER OR STORM WOULD BE POSSIBLE.
THE NAM IS A LITTLE SLOWER WITH THIS WAVE...BUT STILL DRY IN THE
AFTERNOON AS THE STRONGER FORCING REMAINS TO OUR WEST.
CHANCES FOR SHOWERS AND STORMS INCREASE SATURDAY NIGHT INTO SUNDAY
MORNING AS WE GET A BETTER CO-LOCATION OF DEEPER MOISTURE TRANSPORT
COURTESY OF A DECENT LOW LEVEL JET...ANOTHER PACIFIC
DISTURBANCE...AND PWATS APPROACHING 2 INCHES. WE HANG ONTO SE FLOW
AT THE SURFACE FARTHER EAST...WHICH WOULD THEN GIVE THE HIGHER
CONCERN FOR MODERATE TO HEAVY PRECIP RATES SOUTH AND WEST. THERE
IS A SEVERE THREAT GIVEN THE MODEST WESTERLY FLOW NORTH OF THE
RIDGE AND HIGHER DEWPOINTS ADVECTING IN...BUT DESTABILIZATION
CONCERNS EXIST AT THIS POINT IN TIME TO NAIL DOWN THE SPECIFICS
YET. THE MARGINAL RISK IS FOCUSED IN OUR SOUTHWEST AT THIS TIME.
KMD
&&
.LONG TERM...
407 AM CDT
SUNDAY NIGHT THROUGH THURSDAY...
.LONG TERM...
AN UPPER LEVEL LOW QUICKLY MOVES EASTWARD THROUGH SOUTHERN ONTARIO SUNDAY
NIGHT INTO MONDAY...AS THIS OCCURS AND A DEEP TROUGH BUILDS ALONG
THE PACIFIC COAST...UPPER LEVEL RIDGING IN THE WEST WILL CONTINUE
TO AMPLIFY THE FLOW PATTTERN. NW FLOW ON MONDAY WILL KEEP A CHANCE
FOR SHOWERS AND STORMS AROUND AS A WEAK COLD FRONT MOVES THROUGH.
ANOTHER DISTURBANCE GLIDES BY TO OUR NORTH TUESDAY FOR A SOMEWHAT
COOLER THORUGH GENERALLY DRY DAY. A STRAY SHOWER IS POSSIBLE. HIGH
PRESSURE BUILDS IN FOR MID WEEK.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* LAKE BREEZE/SHIFT TO EAST/SOUTHEAST WINDS THIS AFTERNOON.
* POSSIBLE SCATTERED SHOWERS THIS AFTERNOON INTO THE EVENING.
RODRIGUEZ
//DISCUSSION...UPDATED 12Z...
VFR CONDITIONS PERSISTING THIS MORNING WHILE SOUTH/SOUTHEAST
WINDS STEADILY INCREASE. VFR CONDITIONS ARE STILL EXPECTED FOR
MOST OF THE FORECAST PERIOD. HOWEVER...THE POTENTIAL FOR SCATTERED
SHOWERS IS INCREASING AND BECOMING SOONER THAN PREVIOUSLY
EXPECTED. ALTHOUGH THE HIGHEST CHANCES FOR PREIP WILL STAY TO THE
NORTH...AT LEAST SCATTERED DEVELOPMENT IS NOW POSSIBLE THIS
AFTERNOON INTO THE EARLY EVENING. INSTABILITY DOES NOT APPEAR TO
BE THE GREATEST...AND SO THINK THE LIKELIHOOD OF THUNDER IS LOW
AT THIS TIME. LAKE BREEZE PUSH IS STILL APPEARING TO BE LIKELY
THIS AFTERNOON...WITH EAST SOUTHEAST WINDS AT OR ABOVE 10KT
EXPECTED LATER THIS AFTERNOON.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* MEDIUM CONFIDENCE FOR WINDS/LAKE BREEZE TODAY.
* MEDIUM CONFIDENCE FOR SCATTERED SHOWERS.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...SLIGHT CHANCE OF THUNDERSTORMS.
SUNDAY...CHANCE OF THUNDERSTORMS.
MONDAY...CHANCE OF THUNDERSTORMS.
TUESDAY...VFR.
WEDNESDAY...VFR.
THURSDAY...VFR.
RODRIGUEZ
&&
.MARINE...
302 AM CDT
LIGHTER EASTERLY WINDS IN PLACE EARLY THIS MORNING WILL OBSERVE A
STEADY INCREASE TODAY WHILE SHIFTING TO MORE OF A SOUTHERLY
COMPONENT...AS LOW PRESSURE TO THE WEST OVER THE NORTHERN PLAINS
SLOWLY PUSHES EAST. STILL THINK A 10 TO 20 KT WIND WILL BE THE
HIGHEST TODAY...BUT SOME GUIDANCE IS HINTING AT POSSIBLE HIGHER
SPEEDS THROUGHOUT THE DAY. ALTHOUGH I DID INCREASE SPEEDS...DID
NOT GO AS HIGH. HOWEVER...DID MENTION A FEW GUSTS TO 25KT FOR THE
OPEN WATERS TODAY. IT DOES LOOK LIKE A BETTER WINDOW FOR STRONGER
WINDS OF 15 TO 25 KT ACROSS THE NORTH TONIGHT INTO SATURDAY
MORNING...AND HAVE TRENDED THAT WAY WITH THE FORECAST. THIS WILL
BE IN RESPONSE TO THE APPROACHING LOW...BUT WITH IT
WEAKENING...SPEEDS WILL DIMINISH SATURDAY INTO SATURDAY NIGHT.
EXACT TIMING AND PLACEMENT OF THE NEXT SYSTEM LATE IN THE WEEKEND
IS STILL UNCERTAIN BUT IT DOES APPEAR TO BE ANOTHER PERIOD WHEN
SPEEDS WILL ONCE AGAIN INCREASE...AT LEAST FOR THE SOUTHERN HALF
OF THE LAKE.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
846 AM EDT FRI AUG 7 2015
.UPDATE...
QUICK UPDATE TO REMOVE CLOUD COVER FOR THIS MORNING BASED ON
SATELLITE TRENDS OVER THE LAST COUPLE OF HOURS AND PULL SCHC POPS
FOR THIS AFTERNOON ACROSS THE WEST AS WAA LOOKS TOO WEAK TO OVERCOME
THE DEEP LAYER OF VERY DRY AIR EVIDENT ON 12Z DTX SOUNDING. MID-
CLOUD AND DIURNAL CU WILL INCREASE BY LATE MORNING/EARLY AFTN
SUPPORTING CURRENT FORECAST HIGHS IN THE MID 70S TO AROUND 80, RIGHT
ABOUT NORMAL FOR EARLY AUGUST. UPDATE TO THE GRIDS AND ZFP
FORTHCOMING.
&&
.AVIATION...ISSUED 604 AM EDT FRI AUG 7 2015
AN UPPER LEVEL DISTURBANCE NEAR THE MINNESOTA/WISCONSIN BORDER WILL
TRACK EAST INTO MICHIGAN TODAY. THIS WILL BRING AN INCREASE IN
CLOUDS THROUGH THE DAY...AND PROVIDE A CHANCE FOR SHOWERS FROM VERY
LATE THIS AFTERNOON THROUGH TONIGHT. A THUNDERSTORM IS ALSO
POSSIBLE...BUT POTENTIAL IS LOW DUE TO LIMITED INSTABILITY. BEST
POTENTIAL FOR SHOWERS WILL BE FURTHER NORTH...NEAR MBS...WITH
CHANCES TAPERING OFF AS YOU MOVE SOUTHWARD. WITH COVERAGE EXPECTED
TO BE LOW OVERALL...MBS WAS THE ONLY TERMINAL TO INCLUDE A
PREVAILING LIGHT SHOWER MENTION IN THE 12Z TAFS.
FOR DTW...A FEW CLOUDS BETWEEN 5000-6000 FEET ARE ALREADY BEING
OBSERVED OVER WISCONSIN THIS MORNING AND SHOULD MOVE INTO THE AREA
AFTER 14Z. LATEST FORECAST MODEL DATA SUGGESTS DAYTIME HEATING AND
AN OVERALL INCREASE IN MOISTURE SHOULD PROVIDE A CEILING NEAR 5000
FEET STARTING AT AROUND 16Z...HOWEVER CONFIDENCE IS NOT HIGH. THIS
CEILING SHOULD BREAK AROUND 00Z AS WE LOSE HEATING. POTENTIAL FOR
SHOWERS THIS EVENING AND EARLY TONIGHT IS VERY LOW...AND NO MENTION
WAS INCLUDED IN THE TAF.
//DTW THRESHOLD PROBABILITIES...
* LOW CONFIDENCE WITH CEILINGS BELOW 5000 FEET THIS AFTERNOON AND
EARLY EVENING.
&&
.PREV DISCUSSION...ISSUED 254 AM EDT FRI AUG 7 2015
SHORT TERM...TODAY AND TONIGHT
UPPER SHORTWAVE OVER THE UPPER MIDWEST WILL TRACK ACROSS MICHIGAN
LATE TODAY AND TONIGHT AS IT RIDES ALONG THE NORTHERN PERIPHERY OF
AN UPPER RIDGE CENTERED OVER THE SOUTHERN PLAINS. THIS SHORTWAVE HAS
BEEN LOOKING MORE IMPRESSIVE ON WATER VAPOR AS THE NIGHT
PROGRESSES...AND HAS BEEN KICKING OFF A PRETTY GOOD COVERAGE OF
SHOWERS AND THUNDERSTORMS OVER MINNESOTA AND WISCONSIN. 00Z NAM/GFS
ONLY CREDIT THIS WAVE WITH A MODEST PUSH OF MID-LEVEL THETA-E
ADVECTION LATE TODAY/TONIGHT...AND LITTLE TO NO QPF OUTPUT OVER THE
AREA. ACTUALLY PREFER THE MORE AGRESSIVE SOLUTIONS SUCH AS THE
12Z/00Z EURO AND THE HRRR (EVEN THOUGH IT DOESN`T GO OUT QUITE FAR
ENOUGH YET) GIVEN APPEARANCE ON WATER VAPOR. INHERITED FORECAST WAS
ALREADY ON THE AGGRESSIVE SIDE AND CHANGES TO THE FORECAST WERE
MAINLY TO ADJUST TIMING AND INCREASE POPS SLIGHTLY OVER THE SAGINAW
VALLEY. SHOWERS AND PERHAPS A THUNDERSTORM COULD ARRIVE INTO THE
WESTERN PORTION OF THE FORECAST AREA AS EARLY AS 20Z/4PM. BEST
POTENTIAL STILL LOOKS BETWEEN BETWEEN 8PM AND 2AM...AHEAD OF THE
UPPER WAVE AS IT TRACKS INTO MICHIGAN. HIGHEST POPS OVERALL REMAIN
OVER THE SAGINAW VALLEY (MID-RANGE CHANCE)...AND THEN TAPER TO JUST
A SLIGHT CHANCE TOWARDS THE DETROIT AND ANN ARBOR AREAS. ALTHOUGH IT
IS ONLY 12-24 HOUR OUT...MODELS ARE STILL STRUGGLING A LITTLE WITH
TRACK AND TIMING OF THIS SMALL FEATURE. THIS LEADS TO LOWER
CONFIDENCE REGARDING COVERAGE AND TIMING OVERALL.
WITH PLENTY OF HIGH CLOUDS STREAMING IN AHEAD OF THIS UPPER WAVE FOR
THE EARLY PART OF THE DAY...AND A LIGHT EAST FLOW OFF THE
LAKES...EXPECT MAX TEMPERATURES TO CONTINUE RUNNING SLIGHTLY BELOW
NORMAL IN THE MID 70S TO NEAR 80. CLOUD COVER WILL THEN KEEP MIN
TEMPS MILD TONIGHT IN THE UPPER 50S TO LOW 60S.
LONG TERM...
ASIDE FROM A FEW LINGERING SHOWERS OVER THE NORTHERN FORECAST AREA
SATURDAY MORNING...EXPECT A BULK OF THE WEEKEND TO REMAIN DRY AS A
RIDGE OF SURFACE HIGH PRESSURE PERSISTS FROM EASTERN ONTARIO BACK
INTO LAKE HURON AND SOUTHEAST MICHIGAN. A SUBTLE SHORTWAVE RIDGE
WILL ALSO BUILD THROUGH THE AREA AS A FILLING UPPER LOW PRESSURE
SYSTEM LUMBERS EAST ACROSS SOUTHERN CANADA. THIS WILL PROVIDE A
SLIGHTLY WARMER AIRMASS AND ALLOW MAXIMUM TEMPERATURES TO CLIMB INTO
THE LOWER 80S IN MANY AREAS BOTH SATURDAY AND SUNDAY AFTERNOON.
AS THE AFOREMENTIONED RIDGE SHIFTS EAST OF THE AREA EARLY NEXT WEEK
AND MEAN TROUGH AXIS ASSOCIATED WITH WHAT STILL EXISTS OF SOUTHERN
CANADA UPPER LOW ENCROACHES ON THE CENTRAL GREAT LAKES...EXPECT RAIN
CHANCES TO INCREASE FROM SUNDAY EVENING/NIGHT INTO MONDAY. THIS WILL
BE FURTHER ENHANCED AS ADDITIONAL SHORTWAVE ENERGY CURRENTLY OFF THE
CALIFORNIA COAST GRADUALLY WORKS NORTHEAST INTO THE NORTHERN ROCKIES
AND PLAIN STATES AND IS EVENTUALLY FUNNELED INTO THE GREAT LAKES
AROUND THE SOUTHERN PERIPHERY OF LEAD SYSTEM IN CANADA.
ONCE EAST OF THE AREA BY MID NEXT WEEK...THIS SYSTEM WILL AMPLIFY
OVER EASTERN CANADA AND LEAD TO A RATHER NOTABLE UPPER TROUGH FROM
THE CENTRAL/EASTERN GREAT LAKES INTO EASTERN CANADA/NORTHEAST CONUS.
EXPECT DRIER WEATHER WITHIN NORTH/NORTHWEST FLOW ON THE BACK SIDE OF
THIS DEVELOPING TROUGH. THIS EVOLVING PATTERN WILL ALSO LEAD TO
COOLER READINGS ONCE AGAIN WITH MID 70S COMMON FOR AFTERNOON HIGH
TEMPERATURES MID/LATE NEXT WEEK.
MARINE...
HIGH PRESSURE CENTERED OVER LAKE HURON WILL SUSTAIN A LIGHT WIND
INTO TODAY...WITH JUST A MODEST INCREASE IN NORTHEAST WIND LATE IN
THE DAY LEADING TO SOME ENHANCED WAVE DEVELOPMENT OVER THE NEARSHORE
WATERS BY THIS EVENING. GENERALLY WEAKER EAST TO SOUTHEAST WINDS
WILL THEN HOLD THROUGH THE WEEKEND AS THE HIGH PRESSURE CENTER
REMAINS POSITIONED JUST NORTHEAST OF THE REGION.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
UPDATE.......JVC
AVIATION.....HLO
SHORT TERM...HLO
LONG TERM....DG
MARINE.......DG
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
604 AM EDT FRI AUG 7 2015
.AVIATION...
AN UPPER LEVEL DISTURBANCE NEAR THE MINNESOTA/WISCONSIN BORDER WILL
TRACK EAST INTO MICHIGAN TODAY. THIS WILL BRING AN INCREASE IN
CLOUDS THROUGH THE DAY...AND PROVIDE A CHANCE FOR SHOWERS FROM VERY
LATE THIS AFTERNOON THROUGH TONIGHT. A THUNDERSTORM IS ALSO
POSSIBLE...BUT POTENTIAL IS LOW DUE TO LIMITED INSTABILITY. BEST
POTENTIAL FOR SHOWERS WILL BE FURTHER NORTH...NEAR MBS...WITH
CHANCES TAPERING OFF AS YOU MOVE SOUTHWARD. WITH COVERAGE EXPECTED
TO BE LOW OVERALL...MBS WAS THE ONLY TERMINAL TO INCLUDE A
PREVAILING LIGHT SHOWER MENTION IN THE 12Z TAFS.
FOR DTW...A FEW CLOUDS BETWEEN 5000-6000 FEET ARE ALREADY BEING
OBSERVED OVER WISCONSIN THIS MORNING AND SHOULD MOVE INTO THE AREA
AFTER 14Z. LATEST FORECAST MODEL DATA SUGGESTS DAYTIME HEATING AND
AN OVERALL INCREASE IN MOISTURE SHOULD PROVIDE A CEILING NEAR 5000
FEET STARTING AT AROUND 16Z...HOWEVER CONFIDENCE IS NOT HIGH. THIS
CEILING SHOULD BREAK AROUND 00Z AS WE LOSE HEATING. POTENTIAL FOR
SHOWERS THIS EVENING AND EARLY TONIGHT IS VERY LOW...AND NO MENTION
WAS INCLUDED IN THE TAF.
//DTW THRESHOLD PROBABILITIES...
* LOW CONFIDENCE WITH CEILINGS BELOW 5000 FEET THIS AFTERNOON AND
EARLY EVENING.
&&
.PREV DISCUSSION...ISSUED 254 AM EDT FRI AUG 7 2015
SHORT TERM...TODAY AND TONIGHT
UPPER SHORTWAVE OVER THE UPPER MIDWEST WILL TRACK ACROSS MICHIGAN
LATE TODAY AND TONIGHT AS IT RIDES ALONG THE NORTHERN PERIPHERY OF
AN UPPER RIDGE CENTERED OVER THE SOUTHERN PLAINS. THIS SHORTWAVE HAS
BEEN LOOKING MORE IMPRESSIVE ON WATER VAPOR AS THE NIGHT
PROGRESSES...AND HAS BEEN KICKING OFF A PRETTY GOOD COVERAGE OF
SHOWERS AND THUNDERSTORMS OVER MINNESOTA AND WISCONSIN. 00Z NAM/GFS
ONLY CREDIT THIS WAVE WITH A MODEST PUSH OF MID-LEVEL THETA-E
ADVECTION LATE TODAY/TONIGHT...AND LITTLE TO NO QPF OUTPUT OVER THE
AREA. ACTUALLY PREFER THE MORE AGRESSIVE SOLUTIONS SUCH AS THE
12Z/00Z EURO AND THE HRRR (EVEN THOUGH IT DOESN`T GO OUT QUITE FAR
ENOUGH YET) GIVEN APPEARANCE ON WATER VAPOR. INHERITED FORECAST WAS
ALREADY ON THE AGGRESSIVE SIDE AND CHANGES TO THE FORECAST WERE
MAINLY TO ADJUST TIMING AND INCREASE POPS SLIGHTLY OVER THE SAGINAW
VALLEY. SHOWERS AND PERHAPS A THUNDERSTORM COULD ARRIVE INTO THE
WESTERN PORTION OF THE FORECAST AREA AS EARLY AS 20Z/4PM. BEST
POTENTIAL STILL LOOKS BETWEEN BETWEEN 8PM AND 2AM...AHEAD OF THE
UPPER WAVE AS IT TRACKS INTO MICHIGAN. HIGHEST POPS OVERALL REMAIN
OVER THE SAGINAW VALLEY (MID-RANGE CHANCE)...AND THEN TAPER TO JUST
A SLIGHT CHANCE TOWARDS THE DETROIT AND ANN ARBOR AREAS. ALTHOUGH IT
IS ONLY 12-24 HOUR OUT...MODELS ARE STILL STRUGGLING A LITTLE WITH
TRACK AND TIMING OF THIS SMALL FEATURE. THIS LEADS TO LOWER
CONFIDENCE REGARDING COVERAGE AND TIMING OVERALL.
WITH PLENTY OF HIGH CLOUDS STREAMING IN AHEAD OF THIS UPPER WAVE FOR
THE EARLY PART OF THE DAY...AND A LIGHT EAST FLOW OFF THE
LAKES...EXPECT MAX TEMPERATURES TO CONTINUE RUNNING SLIGHTLY BELOW
NORMAL IN THE MID 70S TO NEAR 80. CLOUD COVER WILL THEN KEEP MIN
TEMPS MILD TONIGHT IN THE UPPER 50S TO LOW 60S.
LONG TERM...
ASIDE FROM A FEW LINGERING SHOWERS OVER THE NORTHERN FORECAST AREA
SATURDAY MORNING...EXPECT A BULK OF THE WEEKEND TO REMAIN DRY AS A
RIDGE OF SURFACE HIGH PRESSURE PERSISTS FROM EASTERN ONTARIO BACK
INTO LAKE HURON AND SOUTHEAST MICHIGAN. A SUBTLE SHORTWAVE RIDGE
WILL ALSO BUILD THROUGH THE AREA AS A FILLING UPPER LOW PRESSURE
SYSTEM LUMBERS EAST ACROSS SOUTHERN CANADA. THIS WILL PROVIDE A
SLIGHTLY WARMER AIRMASS AND ALLOW MAXIMUM TEMPERATURES TO CLIMB INTO
THE LOWER 80S IN MANY AREAS BOTH SATURDAY AND SUNDAY AFTERNOON.
AS THE AFOREMENTIONED RIDGE SHIFTS EAST OF THE AREA EARLY NEXT WEEK
AND MEAN TROUGH AXIS ASSOCIATED WITH WHAT STILL EXISTS OF SOUTHERN
CANADA UPPER LOW ENCROACHES ON THE CENTRAL GREAT LAKES...EXPECT RAIN
CHANCES TO INCREASE FROM SUNDAY EVENING/NIGHT INTO MONDAY. THIS WILL
BE FURTHER ENHANCED AS ADDITIONAL SHORTWAVE ENERGY CURRENTLY OFF THE
CALIFORNIA COAST GRADUALLY WORKS NORTHEAST INTO THE NORTHERN ROCKIES
AND PLAIN STATES AND IS EVENTUALLY FUNNELED INTO THE GREAT LAKES
AROUND THE SOUTHERN PERIPHERY OF LEAD SYSTEM IN CANADA.
ONCE EAST OF THE AREA BY MID NEXT WEEK...THIS SYSTEM WILL AMPLIFY
OVER EASTERN CANADA AND LEAD TO A RATHER NOTABLE UPPER TROUGH FROM
THE CENTRAL/EASTERN GREAT LAKES INTO EASTERN CANADA/NORTHEAST CONUS.
EXPECT DRIER WEATHER WITHIN NORTH/NORTHWEST FLOW ON THE BACK SIDE OF
THIS DEVELOPING TROUGH. THIS EVOLVING PATTERN WILL ALSO LEAD TO
COOLER READINGS ONCE AGAIN WITH MID 70S COMMON FOR AFTERNOON HIGH
TEMPERATURES MID/LATE NEXT WEEK.
MARINE...
HIGH PRESSURE CENTERED OVER LAKE HURON WILL SUSTAIN A LIGHT WIND
INTO TODAY...WITH JUST A MODEST INCREASE IN NORTHEAST WIND LATE IN
THE DAY LEADING TO SOME ENHANCED WAVE DEVELOPMENT OVER THE NEARSHORE
WATERS BY THIS EVENING. GENERALLY WEAKER EAST TO SOUTHEAST WINDS
WILL THEN HOLD THROUGH THE WEEKEND AS THE HIGH PRESSURE CENTER
REMAINS POSITIONED JUST NORTHEAST OF THE REGION.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....HLO
SHORT TERM...HLO
LONG TERM....DG
MARINE.......DG
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
1046 AM CDT FRI AUG 7 2015
.DISCUSSION...SEVERE TS WATCH 477 HAS BEEN POSTED GENERALLY FOR AREAS
EAST OF I-55 AND NORTH OF MS 16. DESPITE HRRR EXPECTATIONS THE MCS
MOVING ACROSS NORTH MS WOULD WEAKEN EARLIER THIS MORNING, IT HAS
PERSISTED AND IS NOW MOVING INTO AN INCREASINGLY UNSTABLE ENVIRONMENT
CHARACTERIZED BY SBCAPE IN THE 2000-3000 J/KG RANGE. IN ADDITION,
SOMEWHAT GREATER DEEP LAYER SHEAR EXISTS OVER THE NORTHEASTERN
PORTION OF THE AREA. CURRENT THINKING IS THIS REGIME WILL ALLOW THIS
COMPLEX TO CONTINUE SE-WARD OVER THE NEXT SEVERAL HOURS. PRIMARY
CONCERN IS DAMAGING WINDS, BUT CANNOT RULE OUT MARGINALLY SEVERE HAIL
GIVEN AMPLE INSTABILITY. HAZARD GRAPHICS/HWO WILL BE UPDATED TO
HIGHLIGHT THE AREA IN THE WATCH.
THE SHORT TERM FORECAST HAS BEEN UPDATED TO INCREASE POPS FOR AREAS
IN THE PATH OF THE ONGOING CONVECTION. THE RESULTING TEMP FORECAST
WILL BE PROBLEMATIC, BUT MADE AN EFFORT TO ACCOUNT FOR THE COOLING
THAT WILL TAKE PLACE IN THESE AREAS OVER THE NEXT FEW HOURS. UPDATED
PRODUCTS HAVE BEEN SENT. /DL/
&&
.AVIATION...VFR FLIGHT CATEGORIES ARE PREVAILING ONCE AGAIN AT TAF
SITES ACROSS THE REGION THIS MORNING. WITH HIGH CLOUDS..ASSOCIATED
WITH AN EAST SOUTHEAST MOVING COMPLEX OF STORMS CURRENTLY OVER NORTH
CENTRAL MISSISSIPPI...INCREASING FROM THE NORTH...VFR CATEGORIES ARE
EXPECTED TO PREVAIL AT MOST SITES THROUGH THE COURSE OF THE NEXT 24
HOURS. SHOWERS AND STORMS ARE EXPECTED TO BE MORE PREVALENT OVER
NORTH CENTRAL...NORTHEAST...AND EAST CENTRAL MISSISSIPPI TODAY...
PARTICULARLY THE GOLDEN TRIANGLE AREA WHICH COULD BE CLIPPED BY THE
AFORMENTIONED COMPLEX OF STORMS BY 17Z TODAY. STORMS WILL AGAIN
HAVE THE POTENTIAL OF PRODUCING DAMAGING WIND GUSTS OF 52 KNOTS...
ALONG WITH FREQUENT CLOUD TO GROUND LIGHTNING STRIKES AND HEAVY
DOWNPOURS. FLIGHT CATEGORIES WILL BRIEFLY BE REDUCED TO MVFR/IFR
STATUSES IF CONVECTION IS OBSERVED ON SITE. CONVECTION WILL BEGIN
TO WANE IN BOTH COVERAGE AND INTENSITY AROUND 00Z THIS EVENING...
WITH QUIET CONDITIONS EXPECTED TONIGHT INTO SATURDAY MORNING. /19/
&&
.PREV DISCUSSION... /ISSUED 419 AM CDT FRI AUG 7 2015/
SHORT TERM...TODAY THROUGH SATURDAY NIGHT...TODAY WILL BE SIMILAR TO
THURSDAY IN THAT HEAT AND HUMIDITY WILL REMAIN THE CONCERNS IN THE
WEST WHILE A STRONG TO SEVERE STORM OR TWO WILL AGAIN BE POSSIBLE IN
THE EAST THIS AFTERNOON AND EARLY EVENING. EARLY MORNING WATER VAPOR
IMAGERY/RAP ANALYSIS SHOWED THE CIRCULATION AROUND THE LARGE 594DAM
HIGH CENTERED OVER THE SOUTHERN PLAINS. A WEAK SHORTWAVE WAS NOTED
TOPPING THE HIGH AND SETTING OFF SOME CONVECTION OVER SOUTHWEST
MISSOURI. THIS SHORTWAVE IS EXPECTED TO CONTINUE TRACKING AROUND THE
PERIPHERY OF THE HIGH TODAY AND DROP OVER THE NORTHEAST PORTIONS OF
OUR CWA DURING PEAK HEATING. IT WILL COMBINE WITH OUR MOIST AIR MASS
AND A WEAK SURFACE BOUNDARY TO DEVELOP SOUTHEASTWARD MOVING STORMS
THIS AFTERNOON AND EVENING. A FEW STORMS WILL BE CAPABLE OF 50 TO 60
MPH WINDS. CURRENTLY THE SURFACE BOUNDARY WAS NOTED STALLED JUST
NORTH OF OUR CWA. A FEW SHOWERS WERE BEING DETECTED ON LOCAL RADARS
OVER OUR NORTHEAST MOST COUNTIES. SHOWERS AND A FEW STORMS WILL
REMAIN POSSIBLE OVER OUR NORTHEAST THIS MORNING BUT THIS BOUNDARY IS
EXPECTED TO SAG FARTHER SOUTH INTO OUR CWA AND BECOME ORIENTED
NORTHWEST TO SOUTHEAST BY AFTERNOON RESULTING IN THE MAIN AREA FOR
STRONG TO SEVERE STORMS EAST OF A GREENWOOD TO HATTIESBURG LINE. NO
RAIN IS EXPECTED IN OUR WEST TODAY WHERE TEMPERATURES WILL CONTINUE
TO TOP OUT A LITTLE WARMER THAN THURSDAY. COMBINED WITH THE HUMIDITY
PEAK HEAT INDEX VALUES WILL AGAIN BE 106 TO 110 WHERE A HEAT ADVISORY
WILL REMAIN IN EFFECT. THE LARGE MID LEVEL HIGH WILL BEGIN SHIFTING
EAST SATURDAY WHICH WILL FURTHER LIMIT RAIN CHANCES OVER OUR CWA AND
ALLOW FOR HOTTER TEMPERATURES. WL STILL MAINTAIN A MOIST AIR MASS
WHICH WILL RESULT IN MORE OF OUR CWA COMING UNDER A HEAT ADVISORY.
MODEL CONSENSUS STILL BREAKS OUT CONVECTION OVER OUR EAST THAT WILL
TRACK AROUND THE PERIPHERY OF THE HIGH. THIS ACTIVITY MAY NEGATE THE
EASTERN PORTIONS OF OUR FROM AN ADVISORY. HOWEVER...THE HIGHEST HEAT
INDEX VALUES ARE EXPECTED OVER OUR WEST AGAIN WHERE AN EXCESSIVE HEAT
WARNING MAY BE NEEDED FOR OUR SOUTHEAST ARKANSAS COUNTIES AND
NORTHEAST LOUISIANA PARISHES. AFTERNOON HIGHS ARE EXPECTED TO REACH
THE LOWER 100S THERE AND LEAD TO HEAT INDEX VALUES GREATER THAN 110.
/22/
LONG TERM...SUNDAY THROUGH THURSDAY...THE HOTTEST DAYS OF THE
SUMMER THUS FAR WILL LIKELY OCCUR ON SUNDAY AND MONDAY. THIS COMES
AS THE REGION REMAINS UNDER THE GRIP OF A 595DM UPPER RIDGE. THE
CENTER OF THE RIDGE WILL BE LOCATED ACROSS THE ARKLATEX REGION ON
SUNDAY BEFORE EVENTUALLY RETREATING A LITTLE FURTHER WEST ON MONDAY.
MODELS CONTINUE TO INDICATE THAT SUNDAY AND MONDAY SHOULD BE THE
HOTTEST WE HAVE SEEN THIS SUMMER WITH HIGHS EXCEEDING 100 DEGREES
AREAWIDE BOTH DAYS AND SOME LOCATIONS IN THE WEST EVEN NEARING 105
DEGREES ON MONDAY. NOT ONLY WILL THE ACTUAL AIR TEMPERATURE BE
DANGEROUS ENOUGH BUT THE COMBINATION OF HEAT AND HUMIDITY WILL MAKE
FOR OPPRESSIVE CONDITIONS. THE WESTERN HALF OF THE CWA WILL LIKELY
SEE HEAT INDICES OF 110-115 DEGREES ON SUNDAY AND MONDAY WHILE THE
REMAINDER OF THE CWA WILL BE AROUND 105-110 DEGREES. HEAT ADVISORIES
WILL MOST DEFINITELY BE ISSUED AND EXCESSIVE HEAT WARNINGS WILL BE
LIKELY FOR AT LEAST THE WESTERN AREAS IN LATER FORECAST PACKAGES.
THE CENTER OF THE RIDGE WILL CONTINUE TO TRACK WEST BUT THE REGION
WILL STILL GET HOT AS A COLD FRONT APPROACHES THE REGION FROM THE
NORTH. MODELS INDICATE A SLOW PROGRESSION INTO THE CWA AND COULD
SPARK SOME LATE AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS
ACROSS THE EASTERN PORTION OF THE FORECAST AREA ON MONDAY BUT MOST
LOCATIONS WILL BE DRY. AS THE UPPER RIDGE STRENGTHENS OVER WEST
TEXAS AND THE SOUTHERN PLAINS...THE ARKLAMISS REGION WILL COME UNDER
MORE OF A NORTHWEST FLOW REGIME WHICH WILL HELP DROP THE FRONT SOUTH
INTO AND MOSTLY THROUGH THE CWA ON TUESDAY. BETTER CHANCES OF
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE DURING THE AFTERNOON AND
EVENING HOURS WHICH SHOULD HELP BREAK THE OPPRESSIVE HEAT WE HAD
BEEN SEEING FOR SOME LOCATIONS. THE FRONT WILL STALL NEAR THE COAST
AND KEEP RAIN CHANCES CONFINED TO THE HIGHWAY 84 CORRIDOR AND SOUTH
ON WEDNESDAY. MODELS CONTINUE TO INDICATE THAT MUCH DRIER AIR WILL
MOVE SOUTH INTO THE CWA AS A SFC HIGH FROM CANADA MOVES INTO THE
OHIO VALLEY AND NOSES INTO THE NORTHERN PORTIONS OF THE CWA. AS THIS
OCCURS...AN UPPER LOW/TROUGH WILL TRACK SOUTHWEST ACROSS THE EASTERN
PORTION OF THE COUNTRY. PW VALUES ARE FORECAST TO DROP BELOW AN INCH
THROUGH THE END OF THE WEEK INTO NEXT WEEKEND...WITH EVEN SOME
VALUES AROUND A HALF OF AN INCH POSSIBLE. IN ADDITION...TEMPERATURES
LOOK TO DROP FURTHER FROM THE CENTURY MARK AND CLOSER TO WHAT WE
WOULD NORMALLY EXPECT FOR THIS TIME OF YEAR. DESPITE THE FACT THAT
RAIN CHANCES LOOK SLIM TO NONE IN THIS WEATHER PATTERN AND WITH THE
DRIER AIR...PERHAPS THIS IS OUR REWARD FROM MOTHER NATURES REWARD
FOR HAVING TO ENDURE THIS UPCOMING WEEKENDS OPPRESSIVE HEAT AND
HUMIDITY. /28/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 98 78 100 78 / 20 20 22 5
MERIDIAN 96 75 97 75 / 38 36 28 9
VICKSBURG 98 78 100 77 / 8 10 12 3
HATTIESBURG 99 78 98 77 / 24 24 31 13
NATCHEZ 97 78 98 77 / 6 8 14 4
GREENVILLE 98 78 100 78 / 20 17 12 3
GREENWOOD 97 76 98 77 / 54 25 13 3
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR MSZ018-019-034-035-
040>043-047>049-053-054-059.
LA...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR LAZ007>009-015-016-
023>026.
AR...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR ARZ074-075.
&&
$$
DL/19/22/28
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
629 AM CDT FRI AUG 7 2015
.SHORT TERM...(Today and Tonight)
Issued at 0322 AM CDT FRI AUG 07 2015
Convection has developed over southwestern Missouri fueled by a
shortwave aloft and modest low level jet/moisture transport. HRRR
and RAP has good handle on this and pushes it southeast into south
central Missouri shortly after 12Z and should weaken and dissipate
through midday. After that, upper level high over the southern
plains and southwest conus will expand northeast towards the
Ozarks later today and tonight. This will be the beginning of
warming temperatures. Expect mainly sunny skies by this afternoon
which will aid in the rise. Expect warmest readings across
southeast Kansas into southwest Missouri where highs will be in
the lower to middle 90s, and just middle 80s over the eastern
Ozarks. Heat index values will flirt with advisory criteria for a
few hours this afternoon over southeast Kansas and southwest
Missouri, but will hold off on any headlines. A warm and humid
night is in store tonight with lows in the lower to middle 70s.
.LONG TERM...(Saturday through Thursday)
Issued at 0322 AM CDT FRI AUG 07 2015
Main forecast concern in this time frame is heat and heat index
values for both Saturday and Sunday and the need for any heat
related headlines. Upper ridge firmly in place across the Ozarks
both days. The hottest days looks to be Sunday with heat index
values in the 105 to 110 degree range. will likely need advisories
area-wide Sunday and perhaps only the western half of the forecast
area Saturday.
Medium range models continue to advertise a shortwave breaking down
the northern extent of the ridge Sunday night and Monday allowing
for a frontal boundary to make into the area. This will bring rain
chances back into the forecast, with the better chances across
central Missouri. It will also help cool temperatures off. This
wave should be east of the area later Monday with northwest flow
and surface high pressure nudging into the area for Tuesday
through Thursday, for cooler and quieter weather.
&&
.AVIATION...(For the 12Z TAFS through 12Z Saturday Morning)
Issued at 0629 AM CDT FRI AUG 07 2015
Convection will move east of the of KBBG and KSGF terminals by
14Z. After that ceilings will rise into the VFR category for the
remainder of the period as upper ridging builds into the area.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
SHORT TERM...Raberding
LONG TERM...Raberding
AVIATION...Raberding
AREA FORECAST DISCUSSION
NWS RALEIGH NC
622 AM EDT FRI AUG 7 2015
.SYNOPSIS...LOW PRESSURE AND A COLD FRONT WILL PUSH TO OUR SOUTHEAST
TODAY AND TONIGHT. HIGH PRESSURE WILL BUILD OVER THE REGION THIS
WEEKEND.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 622 AM FRIDAY...
QUICK UPDATE TO LOWER POPS ACROSS OUR WESTERN AND CENTRAL
ZONES...INCLUDING THE TRIAD. LATEST HRRR SHOWS THAT WHILE A FEW
SPOTTY SHOWERS ARE POSSIBLE ACROSS OUR WESTERN ZONES TODAY...THE
BEST CHANCE FOR RAIN TODAY WILL BE ACROSS OUR EAST AND NORTHEAST
ZONES. THIS IS SUPPORTED BY THE LATEST WATER VAPOR SATELLITE THAT
SHOWS THE SHORT WAVE TROUGH AXIS AND INFLECTION POINT NOW MOVING
ACROSS OUR NW ZONES...WITH SUBSIDENCE AND DRYING IN ITS WAKE.
PREV NEAR TERM DISC AS OF 320 AM FRIDAY...
LATEST WATER VAPOR SHOWS A WELL-DEFINED SHORT WAVE...THE CENTER OF
WHICH IS MOVING ACROSS SW VA...PROGRESSING EASTWARD. LATEST MODEL
SUITE SHOWS THIS SHORT WAVE MOVING ACROSS THE CAROLINAS DURING THE
DAYTIME TODAY...THEN SHIFTING OFFSHORE TONIGHT. AT THE SURFACE AT
07Z...LOW PRESSURE WAS NOTED JUST WEST OF KRDU...WITH A BOUNDARY
FROM KORF-KIGX-KSVH. THIS SFC LOW AND BOUNDARY WILL SHIFT TO THE
SOUTH AND EAST AS THE AFOREMENTIONED SHORT WAVE MOVES EAST. AS THE
DAY PROGRESSES...LOOK FOR RAIN TO DEVELOP INVOF OF THE BOUNDARY AS
IT SLOWLY PROGRESSES EASTWARD. THE BEST CHANCE FOR TSTM ACTIVITY
WILL BE ALONG, SOUTH, AND EAST OF THIS BOUNDARY WHERE THE UNSTABLE
AIRMASS WILL BE LOCATED. NORTH AND WEST OF THIS BOUNDARY...
INCREASINGLY STABLE AIRMASS SHOULD PRECLUDE THUNDER AND KEEP ANY
RAIN THAT OCCURS THERE ON THE LIGHTER SIDE. THE COMBINATION OF
CONSIDERABLE CLOUDINESS AND PRECIP...AND FALLING LOW LEVEL
THICKNESSES BEHIND THE FRONT WILL RESULT IN COOLER TEMPS...HIGHS
RANGING FROM AROUND 80 NW TO MID 80S SE.
WITH THE SFC BOUNDARY AND MID LEVEL SHORT WAVE SHIFTING OFFSHORE
TONIGHT...LOOK FOR FAIR WEATHER TONIGHT WITH LOWS 65-70...COOLEST NW.
&&
.SHORT TERM /FRIDAY AND FRIDAY NIGHT/...
AS OF 320 AM FRIDAY...
A SHORT WAVE CURRENTLY OVER MN WILL MOVE SE TODAY AND TONIGHT...AND
ON SATURDAY WILL CROSS THE MID ATLANTIC REGION WHILE DROPPING INTO
THE BASE OF THE L/W TROUGH OFF THE EAST COAST. WHILE THIS SHORT WAVE
MAY RESULT IN A FEW SHOWERS ACROSS THE E/NE PORTION OF THE STATE...
CENTRAL NC IS EXPECTED TO REMAIN DRY. NE LOW LEVEL FLOW WILL KEEP
TEMPS A FEW DEGREES COOLER THAN NORMAL...HIGHS IN THE MID 80S. THEN
AS HIGH PRESSURE BUILDS TO OUR NORTH SATURDAY NIGHT...LOOK FOR
DECREASING CLOUDINESS AND COOLER TEMPS...LOWS 62-67...COOLEST NW.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 340 AM FRIDAY...
WEAK HIGH PRESSURE WILL RESIDE OVER THE REGION ON SUNDAY AS THE
UPPER TROUGH ALONG THE EAST COAST SHIFTS EAST AND HEIGHTS ALOFT
BRIEFLY BUILD OVER THE TN/OH VALLEY. MODELS SHOW A FEW WEAK
DISTURBANCES ROUNDING THE NORTHEAST PERIPHERY OF THE RIDGE BOTH
SUNDAY AND MONDAY...THOUGH MOISTURE RETURN AND AMPLE DESTABILIZATION
IS MORE LIKELY ON MONDAY...BEFORE A DEEPER PACIFIC SHORTWAVE IS
PROGGED TO TOP THE RIDGE AND THEN CARVE OUT A DEEPER EAST COAST
TROUGH TUESDAY/WEDNESDAY. A COLD FRONT ATTENDANT TO THE LATTER
SHORTWAVE WILL THEN PUSH INTO THE AREA FROM THE NORTHWEST BY TUESDAY
NIGHT. THE ECMWF AND GFS ARE SHOWING TYPICAL BIASES WITH THE RIDGE
BREAKING DOWN MORE QUICKLY IN THE GFS...AND THUS AN EARLIER ARRIVAL
OF THE FRONT. GIVEN SOME RUN-TO-RUN INCONSISTENCIES AND THE
POTENTIAL FOR CONVECTION TO INFLUENCE THE FRONT...WILL SPLIT THE
DIFFERENCE IN THE TWO MODELS FOR NOW AND SHOW THE FRONT (AND BEST
CHANCE POPS) MOVING INTO THE AREA TUESDAY AFTERNOON. THE FRONT WILL
THEN SETTLE SOUTH OF THE AREA BY WEDNESDAY AS THE ENTIRE UPPER LEVEL
PATTERN AMPLIFIES AND A RELATIVELY COOL HIGH SETTLES FROM THE
MIDWEST TO THE MID-ATLANTIC STATES FOR THE LATTER HALF OF THE WEEK.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 622 AM FRIDAY...
24-HOUR TAF PERIOD: LOW CLOUDS AND FOG WITH LOW-MVFR OR IFR
CONDITIONS EXPECTED THROUGH 14Z...ESP FROM KIXA-KHNZ-KBUY-KGSO-
KEXX...BASICALLY INVOF OF THE FRONT AND WHERE WINDS ARE LIGHT. THIS
WILL GRADUALLY IMPROVE AFTER 14Z THROUGH ABOUT 18Z...WHEN CIGS MAY
LIFT TO LOW-VFR. SHOWERS WILL BE POSSIBLE LATER TODAY MAINLY FROM
KFAY-KRWI...AND NORTHEASTWARD. LOW CLOUDS AND FOG EXPECTED AGAIN
TONIGHT INTO SATURDAY MORNING.
LOOKING AHEAD: VFR CONDITIONS EXPECTED TO RETURN AFTER SUNRISE
SATURDAY...LASTING THROUGH THE WEEKEND. SUB-VFR CONDITIONS POSSIBLE
EARLY NEXT WEEK ASSOC WITH THE NEXT FRONT.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RAH
NEAR TERM...RAH
SHORT TERM...RAH
LONG TERM...22
AVIATION...RAH
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
954 AM CDT FRI AUG 7 2015
.UPDATE...
ISSUED AT 954 AM CDT FRI AUG 7 2015
BASED ON CURRENT TRENDS...INCREASED SKY COVER OVER THE AREA AND
ADDED SOME -RW OVER ERN ND. CURRENT RADAR SHOWS A BAND OF SHOWERS
MOVG INTO THE DVL BASIN AND EXPECT THEM TO CONTINUE E THRU THE
MORNING INTO THE EARLY AFTERNOON HOURS. OTHERWISE...REST OF FCST
LOOKS GOOD.
UPDATE ISSUED AT 632 AM CDT FRI AUG 7 2015
AREAS OF DENSE FOG REMAIN...BUT CONDITIONS APPEAR TO BE SLOWLY
IMPROVING. MAIN CONCERN IS STILL SEVERE POTENTIAL THIS AFTERNOON.
LATEST HRRR DEVELOPS STORMS BY 19Z-20Z...BUT IS USUALLY TOO QUICK
WITH BREAKING THE CAP AND WILL STICK WITH AFTER 21Z TIMING. WILL
NEED TO MONITOR MESOANALYSIS THROUGH THE MORNING TO DETERMINE
EXTENT OF SEVERE POTENTIAL.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 345 AM CDT FRI AUG 7 2015
PATCHY FOG ACROSS THE REGION THIS MORNING WILL DISSIPATE JUST
AFTER SUNRISE.
MAIN CONCERN WILL BE SEVERE POTENTIAL FOR THIS AFTERNOON. STRONG
UPPER LOW ACROSS SOUTHERN CANADA WILL CONTINUE TO PROPAGATE
EASTWARD...SENDING A SFC TROUGH THROUGH THE REGION THIS AFTERNOON.
MLCAPE AHEAD OF THIS FEATURE EXPECTED TO REACH NEAR 2000 J/KG.
SFC CONVERGENCE WILL BE RELATIVELY WEAK (WITH STRONGEST FORCING
REMAIN ACROSS CANADA)...AND COVERAGE OF STORMS WILL BE LIMITED TO
ISOLD/SCT. HOWEVER...GIVEN 0-6KM BULK SHEAR 35-40 KNTS...ANY
STORM THAT DOES INITIATE WILL HAVE THE POTENTIAL TO BECOME SEVERE.
SPC INDICATES A MARGINAL RISK FOR SEVERE STORMS CLOSER TO THE
INTERNATIONAL BORDER...WHICH IS CLOSER TO THE UPPER LOW.
THE NEXT UPPER WAVE WILL APPROACH THE REGION FROM THE SOUTHWEST ON
SATURDAY...BRINING THUNDER CHANCES TO THE SOUTHERN FA (ALONG WITH
STALLED SFC TROUGH). MOST GUIDANCE SUGGESTS STRONGER INSTABILITY
WILL REMAIN SOUTH OF THE REGION...SIGNIFICANTLY LIMITING SEVERE
POTENTIAL.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 345 AM CDT FRI AUG 7 2015
SATURDAY NIGHT-SUNDAY NIGHT...MOST GUIDANCE SUGGESTS HIGH PRESSURE
AND A DRIER AIRMASS WILL BE IN PLACE BY SUNDAY ACROSS THE
REGION...LEADING TO DRY WEATHER. THE OUTLIER IS THE ECMWF WHICH
ATTEMPTS TO MOVE AN UPPER WAVE INTO THE REGION ON SUNDAY. KEPT LOW
POPS ACROSS SE ND...ALTHOUGH ANY ACTIVITY SHOULD REMAIN WEAK GIVEN
THE VERY WEAK INSTABILITY THE MODELS ARE INDICATING.
MONDAY-THURSDAY...EXTENDED PERIOD FEATURES MAINLY DRY CONDITIONS
AT LEAST THROUGH WEDNESDAY AS AN UPPER RIDGE DOMINATES THE HIGH
PLAINS AND EDGES TOWARD THE FORECAST AREA WITH TIME. THIS WILL
TRANSLATE TO SURFACE TEMPERATURES IN THE SEASONALLY WARM LOW TO
MID EIGHTIES DURING THE MIDDLE OF THE WEEK. UPPER LOW ANCHORED
VICINITY OF PACIFIC NORTHWEST WILL MOVE SLOWLY TO THE EAST...SHORT
WAVE(S) OUT AHEAD COULD AFFECT OUR AREA WITH RW/TRW ACTIVITY BY
THURSDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 632 AM CDT FRI AUG 7 2015
FOG WILL DISSIPATE QUICKLY THIS MORNING...LEADING TO VFR
CONDITIONS THROUGH THE DAY. ALTHOUGH THERE IS A CHANCE FOR
THUNDERSTORMS THIS AFTERNOON...COVERAGE IS EXPECTED TO REMAIN
LIMITED.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...HOPKINS
SHORT TERM...TG
LONG TERM...WJB/TG
AVIATION...TG
AREA FORECAST DISCUSSION
NWS BISMARCK ND
929 AM CDT FRI AUG 7 2015
.UPDATE...
ISSUED AT 918 AM CDT FRI AUG 7 2015
SURFACE AND UPPER LEVEL LOW OVER SOUTHEAST SASKATCHEWAN WITH A
COLD FRONT MOVING THROUGH CENTRAL NORTH DAKOTA. SCATTERED SHOWERS
AND ISOLATED THUNDER ALONG THE FRONT WILL TRACK ACROSS CENTRAL
NORTH DAKOTA THIS MORNING. WILL KEEP THE THREAT OF THUNDER OVER
THE SOUTHEAST CWA INTO THE AFTERNOON WITH FRONT LAGGING HERE AND
MOVING INTO A MORE UNSTABLE AIRMASS. FOR THE MORNING UPDATE...MAIN
MAIN CHANGE WAS CLOUDS AND POPS BASED ON LATEST SATELLITE AND
RADAR. ALSO...FOG HAS RAPIDLY DISSIPATED DURING THE PAST HOUR OR
SO.
UPDATE ISSUED AT 618 AM CDT FRI AUG 7 2015
FOG IS CLEARLY EVIDENT VIA WEBCAMS THIS MORNING. THE LAYER IS
QUITE THIN AS THE MOON IS VISIBLE WHEN LOOKING UP...DESPITE LESS
THAN 1/4 MILE VISIBILITY WHEN LOOKING HORIZONTALLY. LIGHT
PRECIPITATION MOVING THROUGH SOUTH CENTRAL SHOULD DISSIPATE FOG
RAPIDLY THIS MORNING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM CDT FRI AUG 7 2015
FORECAST HIGHLIGHT IN THE SHORT TERM PERIOD IS FOG THIS MORNING.
CURRENTLY...ZONAL FLOW ALOFT WITH DEEP LOW PRESSURE OVER FAR
SOUTH CENTRAL CANADA AND RIDGING OVER THE SOUTHERN AND CENTRAL
PLAINS. BAND OF SHOWERS OVER SOUTHEAST MONTANA STRETCHING EASTWARD
INTO FAR SOUTHWEST NORTH DAKOTA ALONG A COLD FRONTAL BOUNDARY AND
UNDERNEATH AN UPPER JET. HIGH RES MODELS CONTINUE TO BRING THIS
PRECIPITATION INTO MY SOUTHWEST NOW THROUGH 10Z...SPREADING EAST
INTO MY SOUTH CENTRAL COUNTIES THROUGH THE AM HOURS. A FEW
LIGHTNING STRIKES BUT WILL KEEP THUNDER OUT OF THE MORNING
FORECAST WITH LITTLE TO NO CAPE ACROSS SOUTHERN NORTH DAKOTA.
AREAS OF FOG MAINLY OVER NORTHWESTERN...CENTRAL AND EASTERN
PORTIONS OF THE STATE. LATEST HRRR VISIBILITY OUTPUT INDICATES FOG
PERSISTING UNTIL 12-15Z THIS MORNING ACROSS THE AFOREMENTIONED
AREAS. HRRR DOES REMOVE FOG NORTHWEST WHERE WE CURRENTLY HAVE
INCREASING UPPER CLOUDS AND WHERE WINDS WILL SHIFT TO SOUTHWEST
PROMOTING DRY AIR ADVECTION. WITH VISIBILITIES COMING UP AND DOWN
OPTING TO GO WITH A SPECIAL WEATHER STATEMENT FOR NOW HIGHLIGHTING
THE FOG VERSUS HEADLINES.
CHANCES FOR PRECIPITATION WILL CONTINUE TO MOVE EAST ACROSS THE
SOUTH NEAR THE COLD FRONTAL BOUNDARY TODAY INTO THE EVENING HOURS
WHEN FORCING ALOFT WILL BE PRESENT WITH THE UPPER JET. WILL
MENTION THUNDER POTENTIAL IN THE AFTERNOON AND EVENING WHEN
DAYTIME HEATING WILL RESULT IN DIURNAL INSTABILITY. FORCING
DECREASING LATER THIS EVENING SO WENT DRY OVERNIGHT. BREEZY ACROSS
THE NORTH TODAY NEAR THE UPPER LOW...SUB WIND ADVISORY MAGNITUDES.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 322 AM CDT FRI AUG 7 2015
THE MAIN FORECAST FOCUS IS ON THE POTENTIAL FOR PRECIPITATION ALONG
AND SOUTH OF I-94 THIS WEEKEND.
FAR SOUTHERN NORTH DAKOTA AND THE NORTHERN THIRD OF SOUTH DAKOTA ARE
THE CONSENSUS HOT SPOT FOR CONVECTION SATURDAY NIGHT AND
SUNDAY...ACCORDING TO THE 00 UTC GFS/ECMWF/GEFS/GEM GLOBAL
CONSENSUS. THUNDERSTORMS WILL LIKELY MOVE SLOWLY...BUT FLOOD RISK IS
LOW GIVEN LACK OF ANOMALOUS PRECIPITABLE WATER AND RECENT
DEMONSTRATION THAT SOILS CAN HANDLE OVER TWO INCHES PER HOUR WITHOUT
FLASH FLOODING.
IN ITS WAKE...THERE IS GENERAL CONSENSUS AMONG THE 00 UTC
GFS/ECMWF/GEFS/GEM GLOBAL SUITE THAT COMPLEX UPPER LEVEL FLOW WILL
EVOLVE INTO A SIMPLER WEST COAST TROUGH WITH AMPLIFIED RIDGING OVER
THE GREAT PLAINS BY MONDAY MORNING. ASSOCIATED BROAD SCALE
SUBSIDENCE SHOULD BE SUFFICIENT TO SQUELCH CONVECTION UNTIL AT LEAST
WEDNESDAY MORNING. UNCERTAINTY INCREASES THEREAFTER AS SEVERAL
ENSEMBLE MEMBERS EJECT SHORTWAVE ENERGY INTO EASTERN MONTANA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 918 AM CDT FRI AUG 7 2015
AREAS OF FOG ACROSS THE REGION WITH SHORT RANGE MODELS HINTING AT
FOG PERSISTING UNTIL 13-15Z. LIFR-VLIFR CIGS ALSO OCCURRING WITH THE
FOG. VFR FOR THE REMAINDER OF THE PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TWH
SHORT TERM...NH
LONG TERM...SCHECK
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
632 AM CDT FRI AUG 7 2015
.UPDATE...
ISSUED AT 632 AM CDT FRI AUG 7 2015
AREAS OF DENSE FOG REMAIN...BUT CONDITIONS APPEAR TO BE SLOWLY
IMPROVING. MAIN CONCERN IS STILL SEVERE POTENTIAL THIS AFTERNOON.
LATEST HRRR DEVELOPS STORMS BY 19Z-20Z...BUT IS USUALLY TOO QUICK
WITH BREAKING THE CAP AND WILL STICK WITH AFTER 21Z TIMING. WILL
NEED TO MONITOR MESOANALYSIS THROUGH THE MORNING TO DETERMINE
EXTENT OF SEVERE POTENTIAL.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 345 AM CDT FRI AUG 7 2015
PATCHY FOG ACROSS THE REGION THIS MORNING WILL DISSIPATE JUST
AFTER SUNRISE.
MAIN CONCERN WILL BE SEVERE POTENTIAL FOR THIS AFTERNOON. STRONG
UPPER LOW ACROSS SOUTHERN CANADA WILL CONTINUE TO PROPAGATE
EASTWARD...SENDING A SFC TROUGH THROUGH THE REGION THIS AFTERNOON.
MLCAPE AHEAD OF THIS FEATURE EXPECTED TO REACH NEAR 2000 J/KG.
SFC CONVERGENCE WILL BE RELATIVELY WEAK (WITH STRONGEST FORCING
REMAIN ACROSS CANADA)...AND COVERAGE OF STORMS WILL BE LIMITED TO
ISOLD/SCT. HOWEVER...GIVEN 0-6KM BULK SHEAR 35-40 KNTS...ANY
STORM THAT DOES INITIATE WILL HAVE THE POTENTIAL TO BECOME SEVERE.
SPC INDICATES A MARGINAL RISK FOR SEVERE STORMS CLOSER TO THE
INTERNATIONAL BORDER...WHICH IS CLOSER TO THE UPPER LOW.
THE NEXT UPPER WAVE WILL APPROACH THE REGION FROM THE SOUTHWEST ON
SATURDAY...BRINING THUNDER CHANCES TO THE SOUTHERN FA (ALONG WITH
STALLED SFC TROUGH). MOST GUIDANCE SUGGESTS STRONGER INSTABILITY
WILL REMAIN SOUTH OF THE REGION...SIGNIFICANTLY LIMITING SEVERE
POTENTIAL.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 345 AM CDT FRI AUG 7 2015
SATURDAY NIGHT-SUNDAY NIGHT...MOST GUIDANCE SUGGESTS HIGH PRESSURE
AND A DRIER AIRMASS WILL BE IN PLACE BY SUNDAY ACROSS THE
REGION...LEADING TO DRY WEATHER. THE OUTLIER IS THE ECMWF WHICH
ATTEMPTS TO MOVE AN UPPER WAVE INTO THE REGION ON SUNDAY. KEPT LOW
POPS ACROSS SE ND...ALTHOUGH ANY ACTIVITY SHOULD REMAIN WEAK GIVEN
THE VERY WEAK INSTABILITY THE MODELS ARE INDICATING.
MONDAY-THURSDAY...EXTENDED PERIOD FEATURES MAINLY DRY CONDITIONS
AT LEAST THROUGH WEDNESDAY AS AN UPPER RIDGE DOMINATES THE HIGH
PLAINS AND EDGES TOWARD THE FORECAST AREA WITH TIME. THIS WILL
TRANSLATE TO SURFACE TEMPERATURES IN THE SEASONALLY WARM LOW TO
MID EIGHTIES DURING THE MIDDLE OF THE WEEK. UPPER LOW ANCHORED
VICINITY OF PACIFIC NORTHWEST WILL MOVE SLOWLY TO THE EAST...SHORT
WAVE(S) OUT AHEAD COULD AFFECT OUR AREA WITH RW/TRW ACTIVITY BY
THURSDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 632 AM CDT FRI AUG 7 2015
FOG WILL DISSIPATE QUICKLY THIS MORNING...LEADING TO VFR
CONDITIONS THROUGH THE DAY. ALTHOUGH THERE IS A CHANCE FOR
THUNDERSTORMS THIS AFTERNOON...COVERAGE IS EXPECTED TO REMAIN
LIMITED.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...TG
SHORT TERM...TG
LONG TERM...WJB/TG
AVIATION...TG
AREA FORECAST DISCUSSION
NWS BISMARCK ND
628 AM CDT FRI AUG 7 2015
.UPDATE...
ISSUED AT 618 AM CDT FRI AUG 7 2015
FOG IS CLEARLY EVIDENT VIA WEBCAMS THIS MORNING. THE LAYER IS
QUITE THIN AS THE MOON IS VISIBLE WHEN LOOKING UP...DESPITE LESS
THAN 1/4 MILE VISIBILITY WHEN LOOKING HORIZONTALLY. LIGHT
PRECIPITATION MOVING THROUGH SOUTH CENTRAL SHOULD DISSIPATE FOG
RAPIDLY THIS MORNING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM CDT FRI AUG 7 2015
FORECAST HIGHLIGHT IN THE SHORT TERM PERIOD IS FOG THIS MORNING.
CURRENTLY...ZONAL FLOW ALOFT WITH DEEP LOW PRESSURE OVER FAR
SOUTH CENTRAL CANADA AND RIDGING OVER THE SOUTHERN AND CENTRAL
PLAINS. BAND OF SHOWERS OVER SOUTHEAST MONTANA STRETCHING EASTWARD
INTO FAR SOUTHWEST NORTH DAKOTA ALONG A COLD FRONTAL BOUNDARY AND
UNDERNEATH AN UPPER JET. HIGH RES MODELS CONTINUE TO BRING THIS
PRECIPITATION INTO MY SOUTHWEST NOW THROUGH 10Z...SPREADING EAST
INTO MY SOUTH CENTRAL COUNTIES THROUGH THE AM HOURS. A FEW
LIGHTNING STRIKES BUT WILL KEEP THUNDER OUT OF THE MORNING
FORECAST WITH LITTLE TO NO CAPE ACROSS SOUTHERN NORTH DAKOTA.
AREAS OF FOG MAINLY OVER NORTHWESTERN...CENTRAL AND EASTERN
PORTIONS OF THE STATE. LATEST HRRR VISIBILITY OUTPUT INDICATES FOG
PERSISTING UNTIL 12-15Z THIS MORNING ACROSS THE AFOREMENTIONED
AREAS. HRRR DOES REMOVE FOG NORTHWEST WHERE WE CURRENTLY HAVE
INCREASING UPPER CLOUDS AND WHERE WINDS WILL SHIFT TO SOUTHWEST
PROMOTING DRY AIR ADVECTION. WITH VISIBILITIES COMING UP AND DOWN
OPTING TO GO WITH A SPECIAL WEATHER STATEMENT FOR NOW HIGHLIGHTING
THE FOG VERSUS HEADLINES.
CHANCES FOR PRECIPITATION WILL CONTINUE TO MOVE EAST ACROSS THE
SOUTH NEAR THE COLD FRONTAL BOUNDARY TODAY INTO THE EVENING HOURS
WHEN FORCING ALOFT WILL BE PRESENT WITH THE UPPER JET. WILL
MENTION THUNDER POTENTIAL IN THE AFTERNOON AND EVENING WHEN
DAYTIME HEATING WILL RESULT IN DIURNAL INSTABILITY. FORCING
DECREASING LATER THIS EVENING SO WENT DRY OVERNIGHT. BREEZY ACROSS
THE NORTH TODAY NEAR THE UPPER LOW...SUB WIND ADVISORY MAGNITUDES.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 322 AM CDT FRI AUG 7 2015
THE MAIN FORECAST FOCUS IS ON THE POTENTIAL FOR PRECIPITATION ALONG
AND SOUTH OF I-94 THIS WEEKEND.
FAR SOUTHERN NORTH DAKOTA AND THE NORTHERN THIRD OF SOUTH DAKOTA ARE
THE CONSENSUS HOT SPOT FOR CONVECTION SATURDAY NIGHT AND
SUNDAY...ACCORDING TO THE 00 UTC GFS/ECMWF/GEFS/GEM GLOBAL
CONSENSUS. THUNDERSTORMS WILL LIKELY MOVE SLOWLY...BUT FLOOD RISK IS
LOW GIVEN LACK OF ANOMALOUS PRECIPITABLE WATER AND RECENT
DEMONSTRATION THAT SOILS CAN HANDLE OVER TWO INCHES PER HOUR WITHOUT
FLASH FLOODING.
IN ITS WAKE...THERE IS GENERAL CONSENSUS AMONG THE 00 UTC
GFS/ECMWF/GEFS/GEM GLOBAL SUITE THAT COMPLEX UPPER LEVEL FLOW WILL
EVOLVE INTO A SIMPLER WEST COAST TROUGH WITH AMPLIFIED RIDGING OVER
THE GREAT PLAINS BY MONDAY MORNING. ASSOCIATED BROAD SCALE
SUBSIDENCE SHOULD BE SUFFICIENT TO SQUELCH CONVECTION UNTIL AT LEAST
WEDNESDAY MORNING. UNCERTAINTY INCREASES THEREAFTER AS SEVERAL
ENSEMBLE MEMBERS EJECT SHORTWAVE ENERGY INTO EASTERN MONTANA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 618 AM CDT FRI AUG 7 2015
AREAS OF FOG ACROSS THE REGION WITH SHORT RANGE MODELS HINTING AT
FOG PERSISTING UNTIL 13-15Z. LIFR-VLIFR CIGS ALSO OCCURRING WITH THE
FOG. VFR FOR THE REMAINDER OF THE PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SCHECK
SHORT TERM...NH
LONG TERM...SCHECK
AVIATION...NH
AREA FORECAST DISCUSSION...UPDATED
NWS GREEN BAY WI
644 AM CDT FRI AUG 7 2015
NEW INFORMATION ADDED TO UPDATE SECTION
.UPDATE...
ISSUED AT 639 AM CDT FRI AUG 7 2015
SOME VERY IMPRESSIVE RAINFALL TOTALS COMING IN FM WRN WI. EAU HAD
2.88 INCHES ALREADY. THE ATM IS STILL MUCH MORE STABLE IN THE
E...THOUGH THE INSTABILITY AXIS OUT W SHOULD GRADUALLY LEAN EWD
INTO THE FCST AREA. POSN OF UPR VORT ON STLT IMAGERY AS WELL AS
THE HIGHEST RETURNS ON RADAR MOSAIC SUGGEST AXIS OF HEAVIEST RAIN
COULD OCCUR FARTHER S THAN EARLIER ANTICIPATED. UPDATED GRIDS
BASED ON THIS IDEA ALREADY SENT. WL TWEAK HWO TO REMOVE WORDING
CONFINING HEAVY RAIN TO THE NORTH...AND ISSUE AN SPS.
&&
.SYNOPSIS...
ISSUED AT 406 AM CDT FRI AUG 7 2015
MUCH NEEDED RAINFALL EXPECTED FOR MOST OF THE AREA TODAY.
THE POSN OF THE MAIN LARGE-SCALE FEATURES WL CHG LITTLE DURING THE
FCST PERIOD...WITH TROF POSNS NEAR THE COASTS AND RIDGING ACRS
THE CENTRAL PART OF THE CONTINENT. THE MAIN WESTERLIES ACRS THE
NRN CONUS CURRENTLY ARE RATHER LOW-AMPLITUDE...AS A SERIES OF
SHRTWVS IS DISTORTING THE MID-CONUS RIDGE. THE MAIN CHG DURING THE
FCST PERIOD WL BE A MARKED AMPLIFICATION OF THE RIDGE NEXT WEEK.
TEMPS WL NOT VARY TOO MUCH FM SEASONAL NORMALS. THE MAIN
OPPORTUNITIES FOR PCPN WL OCCUR TDA AND DURING THE LATTER PART OF
THE WEEKEND. AFTER TDA/S SYSTEM EXITS THE AREA...PCPN AMNTS WL
PROBABLY BE BLO NORMAL FOR THE REST OF THE PERIOD.
&&
.SHORT TERM...TODAY...TONIGHT...AND SATURDAY
ISSUED AT 406 AM CDT FRI AUG 7 2015
FCST FOCUS IS ON SHARS-LIKE SYSTEM CROSSING THE AREA TDA. THE
SYSTEM PRODUCED SIG WX TO OUR W YDA...WITH SEVERAL TORNADOES
APPARENTLY OCCURRING IN MN...AND HVY RAIN IN SOME PLACES AS WELL.
THE SYSTEM IS MOVG OUT OF THE AXIS OF GREATEST MOISTURE AND
INSTABILITY...SO AN EXACT REPEAT IS UNLIKELY ACRS OUR AREA TDA.
STILL...THE SYSTEM WL ACT ON INCRG MOISTURE TO GENERATE FAIRLY
WIDESPREAD SHRA ACRS THE FCST AREA TDA. BASED ON EXTRAP OF RADAR
AND STLT IMAGERY...NEARLY CLOSED UPR SHRTWV WL DRIVE EWD RIGHT
ACRS THE FCST AREA. COMMA-HEAD STRUCTURE WL LIKELY TRACK ACRS
N-C/NE WI...GENERALLY N OF HIGHWAY 29...RESULTING IN A WIDESPREAD
SOAKING RAINFALL ACRS THE N. WIDESPREAD CLDS AND PCPN WL GREATLY
LIMIT DESTABILIZATION...AND SUPPORT ONLY ISOLD THUNDER. BUT WL
NEED TO KEEP A CLOSE WATCH ON THE FAR SRN PART OF THE FCST AREA.
ALTHOUGH UNLIKELY...IF SUFFICIENT BREAKS IN THE CLDS WERE TO
DEVELOP FOR DESTABILIZATION TO OCCUR...CONDITIONS COULD BECOME
FAVORABLE FOR LOW-TOPPED SUPERCELLS.
ADDED HVY RAINFALL ATTRIBUTE TO THE GRIDS...NOT BECAUSE OF THE
POTENTIAL FOR TORRENTIAL RAINS WITH TSTMS...BUT MORE FOR EFFICIENT
SHRA/TSRA THAT COULD PERSIST FOR SEVERAL HRS AS THE COMMA HEAD
STRUCTURE PUSHES ACRS THE AREA. SOME RUNS OF THE HRRR PRODUCED
RAINFALLS OF UP TO 3.5 INCHES ACRS PORTIONS OF THE FCST AREA. A
WIDESPREAD 1-2 INCH RAINFALL ACRS THE N SEEMS MORE LIKELY...WITH A
FEW LOCATIONS POSSIBLY EXCEEDING 2 INCHES. THE DURATION OF THE
RAINFALL SEEMS TO FAVOR MAINLY PONDING OF WATER IN LOW-LYING AREAS
RATHER THAN FLASH FLOODING. WL DETAIL SITN IN THE HWO.
TIMING THE ENDING OF THE PCPN WAS DIFFICULT. BACK EDGE OF PCPN WAS
STILL MAKING STEADY EWD PROGRESS EARLY THIS MORNING...AND PURE
EXTRAPOLATION WOULD TAKE IT OUT OF THE ARE MUCH FASTER THAN
DEPICTED ON THE MODELS. SUSPECT SYSTEM WL SLOW A BIT AS UPR
SPEED MAX BECOMES SITUATED MORE ON THE UPSTREAM SIDE OF THE
TROF...AND SOME ADDITIONAL PCPN DEVELOPMENT WL EVENTUALLY OCCUR
ALONG THE TRAILING EDGE OF THE SYSTEM. BUILT POP GRIDS WITH
CATEGORICAL POPS SHIFTG THROUGH THE N DURING THE DAY...BUT
LINGERED SCT/ISOLD POPS BACK TO THE SW WELL INTO TNGT. TEMPS TDA
NOT LIKELY TO RISE VERY FAR WITH WIDESPREAD CLDS AND PCPN.
EXPECT SOME FOG TO DEVELOP OVERNIGHT. THERE COULD ALSO BE QUITE A
BIT OF LINGERING LOW CLD COVER. IF BREAKS IN THE LOW CLDS ARE MORE
SIG THAN EXPECTED...DENSE FOG COULD BECOME A PROBLEM.
QUIET WX EXPECTED SAT AS THE NEXT SYSTEM WL FIRST BE APPROACHING
FM THE W. SLOWED THE ARRIVAL OF THE POPS WITH THAT SYSTEM FM WHAT
WAS IN PREV FCST.
.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY
ISSUED AT 406 AM CDT FRI AUG 7 2015
A PATTERN SHIFT IS EXPECTED BY EARLY NEXT WEEK AS 500MB RIDGE
BUILDS ACROSS THE ROCKIES AND TROUGH DEEPENS ACROSS EASTERN
CANADA. THIS WILL LEAVE THE REGION IN A NORTHWEST FLOW PATTERN.
TEMPERATURES WILL TREND TOWARDS BELOW NORMAL READINGS BY THE
MIDDLE OF NEXT WEEK BEFORE REBOUNDING LATE IN THE WEEK AHEAD
OF A COLD FRONT.
MAIN CONCERN WILL BE THE TIMING OF PRECIPITATION CHANCES SATURDAY
NIGHT INTO SUNDAY NIGHT AS A COLD FRONT MOVES THROUGH THE AREA.
MODELS IN BETTER AGREEMENT WITH TIMING OF PRECIPITATION. CHANCES
FOR SHOWERS AND STORMS WILL INCREASE LATER SATURDAY NIGHT...WITH
THE BEST CHANCE FOR SHOWERS AND STORMS SUNDAY INTO SUNDAY EVENING
AS FRONT MOVES THROUGH THE REGION. MAIN CONCERN WILL THE
POSSIBILITY OF LOCALLY HEAVY RAIN. ENOUGH LINGERING MOISTURE AND
WEAK DISTURBANCE MOVING ACROSS THE REGION ON MONDAY COULD TRIGGER
AN ISOLATED SHOWER OR STORM ACROSS NORTHEAST OR EAST-CENTRAL
WISCONSIN. ANOTHER DISTURBANCE DROPPING SOUTHEAST OUT OF CANADA
NEEDS TO BE WATCHED FOR TUESDAY INTO TUESDAY AFTERNOON. LATEST
ECMWF DOES DEPICT PRECIPITATION DURING THIS PERIOD. WILL WAIT
FOR A FEW MORE MODEL RUNS TO SEE IF THIS SCENARIO IS STILL
DEPICTED BEFORE ADDING A CHANCE OF PRECIPITATION DURING THIS
PERIOD. OTHERWISE...DRY CONDITIONS WILL PREVAIL THROUGH THURSDAY.
&&
.AVIATION...FOR 12Z TAF ISSUANCE
ISSUED AT 406 AM CDT FRI AUG 7 2015
FLIGHT CONDITIONS EXPECTED TO DETERIORATE TDA...AND WL PROBABLY
REMAIN POOR TNGT. PREV TAF SET BROUGHT CONDITIONS DOWN TO LOWER-
END MVFR AND IFR CONDITIONS BY MIDNIGHT SAT. PLAN TO CONT THAT
WITH THE 12Z ISSUANCE AS THE POOR FLIGHT CONDITIONS WL TAKE UNTIL
AT LEAST SAT MORNING TO IMPROVE.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE.........SKOWRONSKI
SYNOPSIS.......SKOWRONSKI
SHORT TERM.....SKOWRONSKI
LONG TERM......ECKBERG
AVIATION.......SKOWRONSKI
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
414 AM MDT FRI AUG 7 2015
.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 400 AM MDT FRI AUG 7 2015
THE MAIN CONCERN WITH THIS PORTION OF THE FORECAST IS THE POTENTIAL
FOR SEVERE CONVECTION THIS AFTERNOON/EVENING IN THE NEBRASKA PANHANDLE
AND THE POTENTIAL FOR RAIN AND THUNDERSTORMS ACROSS AREAS WEST OF
THE LARAMIE RANGE THIS EVENING.
TODAY AND TONIGHT:
LATEST WATER VAPOR LOOP WAS SHOWING A FAIRLY STRONG SHORTWAVE
MOVING THROUGH CENTRAL CALIFORNIA. AHEAD OF THIS FEATURE...THERE
IS A GOOD FETCH OF MOISTURE FROM THE PACIFIC WITH THE BULK OF THIS
MOISTURE STILL IN NEVADA AND UTAH. MEANWHILE...IN THE HIGH PLAINS
OF NORTHEAST COLORADO AND THE SOUTHERN PANHANDLE THE SURFACE
OBSERVATIONS ARE SHOWING QUITE A POOL OF LOW LEVEL MOISTURE WITH
DEWPOINTS IN THE 60S. SURFACE ANALYSIS IS ALREADY SHOWING THE LEE
TROUGH DEVELOPING IN RESPONSE TO THE SHORTWAVE IN CALIFORNIA.
PIECES OF ENERGY EJECTING AHEAD OF THIS SHORTWAVE COULD SET THE
STAGE FOR AN ACTIVE SEVERE WEATHER DAY ACROSS THE HIGH PLAINS OF
NEBRASKA AND PORTIONS OF SOUTHEAST WYOMING. THE MAIN QUESTION WILL
BE THE LOCATION OF THE BEST LOW LEVEL CONVERGENCE. THE HRRR IS
SHOWING THE INITIAL BOUNDARY SITUATED FROM KIMBALL TO ALLIANCE
NEBRASKA AROUND MID AFTERNOON. THEN THE PICTURE GETS MORE COMPLEX
AS THE AFTERNOON WEARS ON. THE NAM/HRRR SHOW ANOTHER FOCUS FOR
CONVERGENCE JUST EAST OF THE LARAMIE RANGE NEAR WHEATLAND AND
TORRINGTON. IF THIS SECONDARY AREA OF CONVERGENCE GETS
GOING....THE SEVERE WEATHER MAY SPREAD FURTHER NORTH AND WEST.
SHEAR IS QUITE STRONG FOR THIS TIME OF YEAR WITH 0-6KM VALUES OF
40 TO 50 KTS AND SURFACE BASED CAPES OF 2000 TO 3000J/KG. THESE
CONVERGENT BOUNDARIES COULD ALSO SERVE AS A FOCUS FOR TORNADOS
ESPECIALLY IF WE GET GOOD STRETCHING FROM THE STEEP LOW LEVEL
LAPSE RATES. AT THIS POINT...WE WOULD SAY THAT THE BEST SHOT FOR
SUPERCELLS PRODUCING LARGE HAIL...DAMAGING WINDS AND POSSIBLY
ISOLATED TORNADOS WOULD BE SOUTH OF A TORRINGTON TO ALLIANCE LINE
WITH THE RIGHT MOVERS GENERALLY MOVING EAST-SOUTHEAST. IF STORMS
GET GOING FURTHER NORTH THEY WILL GENERALLY LIFT NORTHEAST WITH
THE MAIN THREATS BEING GUSTY WINDS AND SMALL HAIL.
THIS EVENING:
ONGOING SEVERE WEATHER WILL BE POSSIBLE IN THE PANHANDLE. MEANWHILE...
THE MODELS ARE ADVERTISING A MID LEVEL SHORTWAVE MOVING THROUGH AREAS
WEST OF THE LARAMIE RANGE. THE DEEPER MOISTURE IS ALSO PROGGED TO
MOVE INTO THIS REGION DURING THAT TIME. NOT EXPECTING MUCH IN THE
WAY OF SEVERE WEATHER WITH THIS WAVE...BUT IT COULD BRING A GOOD
SHOT OF BENEFICIAL RAINFALL TO AREAS WEST OF THE LARAMIE RANGE
WHERE WILDFIRES HAVE BEEN PRESENT. THE RAIN SHOULD DIMINISH BY
MIDNIGHT OR SO AND MAY DISSIPATE AS IT CROSSES OVER THE LARAMIE
RANGE.
SATURDAY-SATURDAY NIGHT:
THE MAIN UPPER LEVEL WAVE IS PROGGED TO LIFT NORTHEAST TOWARDS
NORTHWEST WYOMING DURING THE MORNING AND THEN PUSH THROUGH NORTHERN
WYOMING AND SOUTHERN MONTANA DURING THE AFTERNOON AND EARLY EVENING.
THE TRACK OF THIS WAVE IS STILL A BIT UNCERTAIN...BUT IT IS VERY
DYNAMIC...SO WE DID INCREASE THE CHANCES OF PRECIP A BIT ACROSS
OUR NORTHERN COUNTIES SATURDAY AND SATURDAY EVENING. THIS AREA MAY
ALSO SEE A STRONG/SEVERE STORMS DUE TO GOOD SHEAR AND DECENT
INSTABILITY. NOT AS CONFIDENT ABOUT THE CONVECTION CHANCES CLOSER
TO I-80...BUT IF THERE IS ENOUGH MOISTURE PRESENT WE WOULD NOT BE
SURPRISED TO SEE A FEW STORMS DEVELOP OVER THE MOUNTAINS.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 400 AM MDT FRI AUG 7 2015
THE 00Z MEDIUM RANGE MODELS CONCUR THAT THE UPPER RIDGE WILL REBUILD
OVER THE ROCKY MOUNTAINS LATE SUNDAY AND EXTEND INTO THE GREAT PLAINS
THROUGH THE MIDDLE OF NEXT WEEK WHILE A UPPER LOW AND ASSOCIATED TROUGH
IMPACTS THE FAR WEST. NORMALLY THIS IS A STABLE PATTERN WITH WARM
TEMPERATURES ALOFT QUASHING DIURNAL CONVECTION. WHILE MOST OF THE
MONSOON MOISTURE WILL BE CHANNELED BETWEEN THE RIDGE AND TROUGH TO
THE WEST...THE ECMWF AND GFS INDICATE SOME MONSOON MOISTURE TRYING
TO INFILTRATE THE RIDGE. OROGRAPHIC LIFT AND THIS MOISTURE MAY RESULT
IN ISOLATED AFTERNOON TSTORM ACTIVITY OVER THE HIGHER TERRAIN OF
SOUTHEAST WY. OTHERWISE...MOST OF THE CWA WILL REMAIN DRY WITH
TEMPERATURES GRADUALLY WARMING EACH DAY. OTHER THAN THE TYPICAL
BREEZES EACH AFTERNOON...WINDS SHOULD NOT BE A PROBLEM FOR FIRE
WEATHER.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 400 AM MDT FRI AUG 7 2015
VFR CONDITIONS WILL PREVAIL OUTSIDE TSTORM ACTIVITY. TSTORMS WILL
INITIALLY FORM LATE THIS MORNING OVER THE MOUNTAINS...WITH ADDITIONAL
DEVELOPMENT ACROSS THE PLAINS DURING THE AFTERNOON. THE MAIN HAZARDS
WILL BE HAIL AND STRONG WIND GUSTS...AS WELL AS MVFR OR LOWER VSBY
UNDER THE HEAVIER SHOWERS. TSTORMS WILL LINGER THROUGH TONIGHT OVER
WESTERN NE PANHANDLE AND WEST OF THE LARAMIE RANGE.
&&
.FIRE WEATHER...
ISSUED AT 400 AM MDT FRI AUG 7 2015
MONSOON MOISTURE WILL BE ON THE INCREASE TODAY IN RESPONSE TO AN UPPER
LEVEL DISTURBANCE MOVING NORTHEAST FROM THE DESERT SOUTHWEST. ALONG
WITH THE INCREASING MOISTURE...SHOWERS AND THUNDERSTORMS WILL BE A
GOOD POSSIBILITY ESPECIALLY IN THE NEBRASKA PANHANDLE THIS AFTERNOON
AND EVENING...AS WELL AS SOME BENEFICIAL RAINFALL MOVING INTO AREAS
WEST OF THE LARAMIE RANGE DURING THE EVENING. OVERALL...WIND SPEEDS
SHOULD ALSO BE LIGHTER TODAY...BUT THEY WILL BE GUSTY AND ERRATIC
NEAR THUNDERSTORMS.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...REC
LONG TERM...MAJ
AVIATION...MAJ
FIRE WEATHER...REC
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
239 PM CDT FRI AUG 7 2015
.SHORT TERM...TONIGHT THROUGH MONDAY NIGHT
AN AREA OF SHOWERS AND THUNDERSTORMS MOVED FROM SOUTH CENTRAL
MISSOURI AND TRACKED SOUTHEAST THROUGH PORTIONS OF EASTERN ARKANSAS.
THESE STORMS CONTINUED TO STRENGTHEN DURING THE MID MORNING HOURS
AND LED TO INCREASED CLOUD COVER THROUGH THE EASTERN HALF OF THE
STATE. BY THE EARLY AFTERNOON HOURS...MOSTLY SUNNY SKIES WERE SEEN
AROUND THE STATE WITH TEMPERATURES WARMING INTO THE MID TO UPPER 90S
WITH A FEW LOCATIONS IN WESTERN ARKANSAS ALREADY TOPPING 100
DEGREES. HEAT INDICES AROUND THE STATE HAVE REACHED 112 AT
RUSSELLVILLE WITH A FEW LOCATIONS TOPPING 110.
FOR TONIGHT...KEPT SLIGHT CHANCE POPS ACROSS EASTERN PORTIONS OF THE
AREA WITH BOTH THE HRRR AND WRF SHOWING REDEVELOPMENT ACROSS EASTERN
ARKANSAS.
IN THE COMING DAYS...WILL CONTINUE TO SEE A STRONG RIDGE OF HIGH
PRESSURE BUILD INTO THE REGION WITH TEMPERATURES EXPECTED TO CLIMB
EVEN HOTTER THAN WHAT HAS BEEN SEEN TODAY. FOR NOW...HAVE EXTENDED
AND EXPANDED THE EXCESSIVE HEAT WARNING INTO SATURDAY AND CONTINUED
WITH THE HEAT ADVISORY AT THE REMAINING COUNTIES EXCEPT ACROSS
NORTHEAST ARKANSAS.
HOT TEMPERATURES WILL CONTINUE ON SUNDAY WITH FEWER CLOUDS AND
SLIGHTLY LOWER DEWPOINTS...GENERALLY ACROSS SOUTHWEST AND CENTRAL
ARKANSAS. HOWEVER DEWPOINTS WILL GENERALLY INCREASE ACROSS NORTHEAST
ARKANSAS WHICH WILL LIKELY CAUSE HEAT ADVISORIES/WARNINGS TO BE
EXTENDED AND EXPANDED.
UPPER LEVEL RIDGE WILL BEGIN TO RETREAT ON MONDAY...ALLOWING A COLD
FRONT TO APPROACH THE STATE FROM THE NORTH. AT THIS POINT...IT DOES
NOT APPEAR THAT THERE WILL BE HIGH CHANCE FOR PRECIPITATION WITH
THIS FRONT...BUT SLIGHTLY COOLER TEMPS AND DRIER AIR WILL MOVE INTO
THE STATE FOR THE LONG TERM.
&&
.LONG TERM...TUESDAY THROUGH FRIDAY NIGHT
THE UPPER LEVEL RIDGE OF HIGH PRESSURE THAT HAS PERSISTED OVER THE
REGION FOR THE PAST SEVERAL WEEKS WILL RETREAT WESTARD DURING THE
EXTENDED TERM...CHANGING THE UPPER LEVEL FLOW PATTERN TO A
NORTHERLY TO NORTHWESTERLY FLOW. AT THE SURFACE A HIGH PRESSURE
SYSTEM WILL SLOWLY MOVE TO THE EAST ACROSS THE UPPER MIDWEST INTO
THE OHIO VALLEY...KEEPING THE FORECAST AREA ALONG THE SOUTHERN
PERIPHERY OF THE HIGH. THIS WILL RESULT IN A DRY NORTHERLY TO
NORTHEASTERLY SURFACE FLOW.
THIS SETUP WILL ALLOW TEMPERATURES TO REMAIN JUST A BIT COOLER THAN
THEY HAVE BEEN AT PRESENT...MOST NOTABLY ACROSS THE NORTHERN HALF OF
THE AREA. SURFACE DEWPOINTS WILL EVENTUALLY DROP DOWN TO BE ABOUT 10
TO 15 DEGREES LOWER THAN THEY ARE RIGHT NOW...WHICH WILL BE A
WELCOME RELIEF...PUSHING MAXIMUM APPARENT TEMPERATURES DOWN INTO THE
MID 80S ACROSS THE NORTH TO THE MID 90S ACROSS THE SOUTH.
WITH THE NORTH TO NORTHWESTERLY FLOW AT THE UPPER LEVELS...A
SHORTWAVE OR TWO COULD RIPPLE ACROSS THE FORECAST AREA DURING THE
EXTENDED TERM...AND ISOLATED SHOWERS AND THUNDERSTORMS CANNOT BE
RULED OUT. HOWEVER...WITH THE MOISTURE LEVELS REMAINING LOWER...THE
CHANCES FOR PRECIPITATION SHOULD BE RATHER LOW...AND BELOW MENTION
IN MANY AREAS.
&&
.PRELIMINARY POINT TEMPS/POPS...
BATESVILLE AR 74 93 76 100 / 20 10 0 10
CAMDEN AR 80 102 79 103 / 10 10 0 10
HARRISON AR 74 96 74 98 / 20 10 0 10
HOT SPRINGS AR 79 102 78 102 / 10 10 0 10
LITTLE ROCK AR 78 100 79 102 / 20 10 0 10
MONTICELLO AR 79 103 79 104 / 20 10 0 10
MOUNT IDA AR 74 102 74 102 / 10 10 0 10
MOUNTAIN HOME AR 73 95 74 100 / 20 10 0 10
NEWPORT AR 73 94 75 97 / 20 10 0 10
PINE BLUFF AR 77 100 78 101 / 20 10 0 10
RUSSELLVILLE AR 78 101 75 102 / 10 10 0 10
SEARCY AR 76 96 75 100 / 20 10 0 10
STUTTGART AR 76 96 76 99 / 20 10 0 10
&&
.LZK WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY FROM 7 AM SATURDAY TO 7 PM CDT SUNDAY FOR BAXTER-
BOONE-INDEPENDENCE-JACKSON-MARION-NEWTON-SEARCY-STONE.
EXCESSIVE HEAT WARNING UNTIL 7 PM CDT SATURDAY FOR BRADLEY-
CALHOUN-CLARK-CLEVELAND-CONWAY-DALLAS-DESHA-DREW-FAULKNER-
GARLAND-GRANT-HOT SPRING-JEFFERSON-JOHNSON-LINCOLN-LOGAN-LONOKE-
OUACHITA-PERRY-POPE-PULASKI-SALINE-YELL.
EXCESSIVE HEAT WARNING FROM 7 AM TO 7 PM CDT SATURDAY FOR
ARKANSAS-MONTGOMERY-PIKE-POLK-PRAIRIE-SCOTT-WHITE.
HEAT ADVISORY UNTIL 7 AM CDT SATURDAY FOR ARKANSAS-MONTGOMERY-
PIKE-POLK-PRAIRIE-SCOTT-WHITE.
HEAT ADVISORY UNTIL 7 PM CDT SUNDAY FOR CLEBURNE-MONROE-VAN
BUREN-WOODRUFF.
&&
$$
SHORT TERM...65 / LONG TERM...53
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
307 PM PDT FRI AUG 7 2015
.SYNOPSIS...
DRIER WEATHER OVER THE WEEKEND WITH HIGH TEMPERATURES NEAR NORMAL.
MINOR COOLING NEXT WEEK WITH A SLIGHT CHANCE OF AFTERNOON THUNDERSTORMS
OVER THE NORTHERN MOUNTAINS TUESDAY INTO THURSDAY.
&&
.DISCUSSION...
UPPER LOW OVER THE SIERRA NEVADA WILL PUSH INTO THE GREAT BASIN
THIS EVENING AS UPSTREAM WEAK SHORT WAVE RIDGING BEGINS TO NUDGE
INLAND. HRRR SHOWING ISOLATED SHOWERS OR THUNDERSTORMS POSSIBLE
OVER THE HIGHER TERRAIN OF THE COASTAL RANGE BETWEEN WESTERN
SHASTA AND NORTH LAKE COUNTY, WESTERN PLUMAS, AND SIERRA NEVADA
UNTIL DARK. KSFO-KSAC SURFACE GRADIENT IS TRENDING UP WITH
MODERATE DELTA BREEZE, WHICH IS EXPECTED TO PERSIST OVERNIGHT,
PROVIDING COOLING INTO THE SOUTHERN SAC VALLEY. HAZE AND PATCHY
SMOKE POSSIBLE IN VICINITY OF WILDFIRES LATER TONIGHT AS BOUNDARY
LAYER STABILIZES.
WEAK UPPER RIDGING MOVES THROUGH EARLY SATURDAY. FLOW ALOFT TURNS
SOUTHWESTERLY OVER THE WEEKEND AND MONDAY AS A DEEP UPPER LOW
MOVES INTO THE NE PACIFIC AND ASSOCIATED TROUGHING EXTENDS
SOUTHWARD NEAR 130W. MODERATE ONSHORE FLOW WILL RESULT WITH NEAR
NORMAL HIGH TEMPERATURES.
&&
.EXTENDED DISCUSSION (TUESDAY THROUGH FRIDAY)
MODELS ARE CONTINUING TO SHOW DIFFERING SOLUTION WITH THE DEEP
UPPER LOW IN NE PAC EARLY NEXT WEEK. 18Z OPER GFS CONTINUES TO
SPLIT ENERGY AND DEVELOPS A SECONDARY LOW OFF THE NORCAL COAST
MONDAY AND SPINS AND DEEPENS THIS FEATURE THROUGH THE WEEK.
MEANWHILE THE 12Z EC CONTINUES TO KEEP THE ENERGY CONSOLIDATED,
DROPPING IT SLOWLY SOUTH ALONG 125W TO OFF THE NORCAL COAST
TUE/WED THEN PROGRESSING NE IT ACROSS THE PACNW THURSDAY. WITH
MODEL UNCERTAINTIES HAVE CONTINUED MENTION OF SLIGHT THREAT OF
AFTERNOON SHOWERS/THUNDERSTORMS OVER THE MOUNTAINS TUE/WED. HAVE
ADDED POPS TO THE NORTHERN MOUNTAINS AGAIN THURSDAY, AS EITHER
MODEL SOLUTION WOULD SUPPORT THIS. BELOW NORMAL TEMPERATURES
EXPECTED THROUGH THURSDAY WITH 80S TO MID 90S FOR THE CENTRAL
VALLEY AND 60S TO LOW 80S FOR THE MOUNTAINS AND FOOTHILLS.
PCH
&&
.AVIATION...
UPR LOW MOVS E INTO GRT BASIN THIS EVE, FLWD BY WK UPR RDG. VFR
CONDS NXT 24 HRS OVR INTR NORCAL EXC MVFR POSS IN ISOLD TSTM OVR
CSTL RNG AND HYR SIERNEV TIL 04Z. LCL SWLY SFC WND GSTS TO 30 KTS
POSS THRU DELTA TNGT.
&&
.STO WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 5 PM PDT THIS AFTERNOON FOR NORTHERN
MOTHERLODE FROM 1000 TO 3000 FT. INCLUDES PORTIONS OF NEVADA-
YUBA-PLACER-AMADOR AND ELDORADO UNITS-NORTHERN SIERRA INCLUDING
THE TAHOE AND ELDORADO NF/S WEST OF THE SIERRA CREST-SOUTHERN
MOTHERLODE FROM 1000 TO 3000 FT. INCLUDES PORTIONS OF CALAVERAS-
TUOLUMNE UNIT-STANISLAUS NF WEST OF THE SIERRA CREST.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
248 PM CDT FRI AUG 7 2015
.UPDATE...
1143 AM CDT
A WEAKENING SURFACE LOW RESIDES OVER FAR WESTERN WISCONSIN...WITH
HIGH PRESSURE CENTERED OVER THE EASTERN AND CENTRAL GREAT LAKES
LATE THIS MORNING. GLANCING BLOW FROM THE MID/UPPER WAVE
ASSOCIATED FROM THE SURFACE LOW THAT IS MAINLY FOCUSED INTO
WISCONSIN WILL GRADUALLY SPREAD ISOLATED TO WIDELY SCATTERED
SHOWERS/SPRINKLES EASTWARD IN NORTHERN ILLINOIS NORTH OF
INTERSTATE 80. WEAKER FORCING WITH SOUTHWARD EXTENT AND DRY LOWER
LEVELS NOTED ON 12Z DVN RAOB AND AIRCRAFT SOUNDINGS WILL KEEP
AREAL COVERAGE LOW. MANY AREAS WILL NOT SEE ANY MEASURABLE
RAINFALL GIVEN THE WEAK FORCING AND LOW AREAL COVERAGE. IN
ADDITION...POOR MIDLEVEL LAPSE RATES WILL LIMIT
DESTABILIZATION...WITH ML AND SB CAPE AXIS STAYING WEST OF THE
AREA THROUGH THE AFTERNOON. THERE COULD BE ENOUGH MUCAPE FOR
SLIGHT CHANCE OF THUNDER THIS AFTERNOON MAINLY NORTHWEST OF A
STERLING TO ANTIOCH LINE...THOUGH THIS COULD EVEN END UP BULLISH.
TEMPERATURES FROM INHERITED FORECAST HAVE BEEN TRACKING VERY WELL
WITH HOURLY OBS...SO HIGHS GENERALLY IN THE LOWER 80S APPEAR ON
TRACK...WITH MID 80S POSSIBLE IN CHICAGO HEAT ISLAND AWAY FROM
MINOR COOLING INFLUENCE OF LAKE BREEZE.
RC
&&
.SHORT TERM...
349 AM CDT
THROUGH SUNDAY...
CONCERNS REVOLVE AROUND PRECIPITATION CHANCES EACH OF THE NEXT FEW
DAYS.
A COMPACT BUT POTENT UPPER LEVEL DISTURBANCE IN MN IS PRODUCING A
COMPLEX OF THUNDERSTORMS NOW MOVING INTO WESTERN WISCONSIN. THERE IS
A WEAK SURFACE REFLECTION WITH THIS FEATURE WHERE THE MORE ORGANIZED
ACTIVITY IS ONGOING. CLOSER TO HOME...SURFACE HIGH PRESSURE IS
HOLDING FIRM JUST NEAR LAKE HURON...WITH THE RIDGE AXIS ORIENTED
SOUTHWESTWARD. IR IMAGERY EARLY THIS MORNING HAS SHOWN A CONTINUAL
EROSION OF THE DEEPER CLOUDS ON THE SOUTHERN END OF THIS COMPLEX AS
IT MOVES INTO DRIER AIR FARTHER SOUTH AND EAST.
AN UPPER LEVEL JET MOVING INTO THE NORTHERN PLAINS WILL ALLOW THIS
UPPER DISTURBANCE TO MOVE SOUTH AND EAST TOWARD THE AREA
TODAY...EVEN OUTRUNNING THE SURFACE LOW. MUCH OF THE NEAR TERM
GUIDANCE KEEPS ERODING PRECIP SOUTH OF THE WISCONSIN BORDER AHEAD OF
THIS SYSTEM. THE EXCEPTION TO THIS THE EXPERIMENTAL HRRR AND
SEVERAL HOP-WRF MEMBERS WHICH ARE A BIT MORE AGGRESSIVE WITH
DRIVING PRECIP THROUGH THE AREA...ESPECIALLY THIS AFTERNOON.
OBSERVATIONS SUGGEST SOME CONTINUED DEVELOPMENT SOUTHWARD THROUGH
THE MORNING INTO THE INSTABILITY AXIS WHICH WILL GRADUALLY
APPROACH FROM THE WEST TODAY. HAVE STILL KEPT POPS ON THE LOWER
SIDE AWAY FROM NORTH CENTRAL ILLINOIS AND POINTS WEST...THOUGH
EXPECT OUR NORTHWESTERN ZONES INTO WINNEBAGO/BOONE/MCHENRY
COUNTIES STAND A CHANCE OF SOME SHOWERS OR A STRAY STORM LATER
THIS MORNING INTO THE AFTERNOON. CONTINUED DRY AIR SHOULD FURTHER
ERODE AT THE PRECIP...THOUGH AS THE DAY GOES ON AND THE
INSTABILITY AXIS SHIFTS EASTWARD WITH THE UPPER LOW...EXPECT THAT
SOME SHOWERS WILL BE POSSIBLE. SOUNDINGS ARE NOT THRILLED ABOUT
THE THUNDER POTENTIAL CLOSER TO CHICAGO WITH CAPPING HOLDING.
TONIGHT...THE UPPER LOW SHIFTS EAST AND OUTPACES THE SURFACE LOW AND
THUS EXPECT SOME DECREASE IN COVERAGE OF SHOWERS AND COULD JUST BE
DRY...THOUGH WILL HANG ONTO A LOW POP MENTION OVERNIGHT FOR SOME
LINGERING LOW LEVEL CONVERGENCE.
SATURDAY...FOCUS SHIFTS TO ENERGY PROPAGATING FROM THE TROUGH OFF
THE CA COAST THIS MORNING. THIS IS FORECAST TO RIDE A DECENT UPPER
JET THROUGH THE PLAINS OVERNIGHT INTO THE MORNING AND ALONG THE
NORTHERN FRINGES OF THE UPPER LEVEL RIDGE AXIS THAT EXTENDS FROM
TEXAS NORTH INTO THE CENTRAL PLAINS. THIS WAVE CRUISES THROUGH
SATURDAY MORNING WITH SURFACE HIGH PRESSURE IN PLACE AND A LACK OF
DEEPER MOISTURE...SO HAVE CONTINUED A DRY FORECAST...AND THAT GOES
FOR SATURDAY AFTERNOON AS WELL AS THE WAVE MOVES EAST. WILL HAVE
TO WATCH THE MORNING PERIOD IF THE LOWER LEVELS MOISTEN UP A BIT
MORE THAN FORECAST THAT A STRAY SHOWER OR STORM WOULD BE POSSIBLE.
THE NAM IS A LITTLE SLOWER WITH THIS WAVE...BUT STILL DRY IN THE
AFTERNOON AS THE STRONGER FORCING REMAINS TO OUR WEST.
CHANCES FOR SHOWERS AND STORMS INCREASE SATURDAY NIGHT INTO SUNDAY
MORNING AS WE GET A BETTER CO-LOCATION OF DEEPER MOISTURE TRANSPORT
COURTESY OF A DECENT LOW LEVEL JET...ANOTHER PACIFIC
DISTURBANCE...AND PWATS APPROACHING 2 INCHES. WE HANG ONTO SE FLOW
AT THE SURFACE FARTHER EAST...WHICH WOULD THEN GIVE THE HIGHER
CONCERN FOR MODERATE TO HEAVY PRECIP RATES SOUTH AND WEST. THERE
IS A SEVERE THREAT GIVEN THE MODEST WESTERLY FLOW NORTH OF THE
RIDGE AND HIGHER DEWPOINTS ADVECTING IN...BUT DESTABILIZATION
CONCERNS EXIST AT THIS POINT IN TIME TO NAIL DOWN THE SPECIFICS
YET. THE MARGINAL RISK IS FOCUSED IN OUR SOUTHWEST AT THIS TIME.
KMD
&&
.LONG TERM...
407 AM CDT
SUNDAY NIGHT THROUGH THURSDAY...
.LONG TERM...
AN UPPER LEVEL LOW QUICKLY MOVES EASTWARD THROUGH SOUTHERN ONTARIO SUNDAY
NIGHT INTO MONDAY...AS THIS OCCURS AND A DEEP TROUGH BUILDS ALONG
THE PACIFIC COAST...UPPER LEVEL RIDGING IN THE WEST WILL CONTINUE
TO AMPLIFY THE FLOW PATTERN. NW FLOW ON MONDAY WILL KEEP A CHANCE
FOR SHOWERS AND STORMS AROUND AS A WEAK COLD FRONT MOVES THROUGH.
ANOTHER DISTURBANCE GLIDES BY TO OUR NORTH TUESDAY FOR A SOMEWHAT
COOLER THOUGH GENERALLY DRY DAY. A STRAY SHOWER IS POSSIBLE. HIGH
PRESSURE BUILDS IN FOR MID WEEK.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* LAKE BREEZE POTENTIAL THIS AFTERNOON.
* ISOLATED SHOWERS TONIGHT.
* BRIEF REDUCTION IN VSBY DUE TO FOG SATURDAY MORNING.
MM
//DISCUSSION...UPDATED 18Z...
TERMINAL DOPPLER RADAR INDICATES LAKE BREEZE BOUNDARY MAKING
INROADS TOWARD ORD EARLY THIS AFTERNOON. LOW LEVEL SOUTHWEST WINDS
HAVE BEEN COMBATING THIS WEAK BOUNDARY TODAY...AND IT DOES APPEAR
THAT THE BOUNDARY MAY REMAIN EAST OF ORD. THE RESULT LEAVES PREVAILING
SSW WINDS LIKELY. IF THE BOUNDARY WERE TO PENETRATE FURTHER...IT
WILL LIKELY BE AFTER A FEW MORE HOURS OF DAYTIME HEATING...NEAR
22Z.
OVERNIGHT A NON-STANDARD WARM FRONT WILL APPROACH THE
AREA...PROVIDING FOCUS FOR SOME SCATTERED SHOWERS. TAF SITES WILL
BE IN THE WARM SECTOR OF THE LOW IN THE MORNING WHICH WILL HELP
FORMATION OF FOG IN THE MORNING. THIS FRONT BECOMES NEARLY
STATIONARY EARLY SATURDAY. THE PRESSURE PATTERN WILL FAVOR WEAK
SOUTHERLY WINDS DURING THE DAY...VEERING TO BECOME NORTHWEST IN
THE LATE AFTERNOON. A LAKE BREEZE IS AGAIN POSSIBLE AFTER 22Z.
MM
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM-LOW IN LAKE BREEZE TODAY.
* MEDIUM IN SHOWERS TONIGHT.
* MEDIUM-LOW IN FOG DENSITY.
MM
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...SLIGHT CHANCE OF THUNDERSTORMS.
SUNDAY...CHANCE OF THUNDERSTORMS.
MONDAY...CHANCE OF THUNDERSTORMS.
TUESDAY...VFR.
WEDNESDAY...VFR.
THURSDAY...VFR.
RODRIGUEZ
&&
.MARINE...
302 AM CDT
LIGHTER EASTERLY WINDS IN PLACE EARLY THIS MORNING WILL OBSERVE A
STEADY INCREASE TODAY WHILE SHIFTING TO MORE OF A SOUTHERLY
COMPONENT...AS LOW PRESSURE TO THE WEST OVER THE NORTHERN PLAINS
SLOWLY PUSHES EAST. STILL THINK A 10 TO 20 KT WIND WILL BE THE
HIGHEST TODAY...BUT SOME GUIDANCE IS HINTING AT POSSIBLE HIGHER
SPEEDS THROUGHOUT THE DAY. ALTHOUGH I DID INCREASE SPEEDS...DID
NOT GO AS HIGH. HOWEVER...DID MENTION A FEW GUSTS TO 25KT FOR THE
OPEN WATERS TODAY. IT DOES LOOK LIKE A BETTER WINDOW FOR STRONGER
WINDS OF 15 TO 25 KT ACROSS THE NORTH TONIGHT INTO SATURDAY
MORNING...AND HAVE TRENDED THAT WAY WITH THE FORECAST. THIS WILL
BE IN RESPONSE TO THE APPROACHING LOW...BUT WITH IT
WEAKENING...SPEEDS WILL DIMINISH SATURDAY INTO SATURDAY NIGHT.
EXACT TIMING AND PLACEMENT OF THE NEXT SYSTEM LATE IN THE WEEKEND
IS STILL UNCERTAIN BUT IT DOES APPEAR TO BE ANOTHER PERIOD WHEN
SPEEDS WILL ONCE AGAIN INCREASE...AT LEAST FOR THE SOUTHERN HALF
OF THE LAKE.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1252 PM CDT FRI AUG 7 2015
.UPDATE...
1143 AM CDT
A WEAKENING SURFACE LOW RESIDES OVER FAR WESTERN WISCONSIN...WITH
HIGH PRESSURE CENTERED OVER THE EASTERN AND CENTRAL GREAT LAKES
LATE THIS MORNING. GLANCING BLOW FROM THE MID/UPPER WAVE
ASSOCIATED FROM THE SURFACE LOW THAT IS MAINLY FOCUSED INTO
WISCONSIN WILL GRADUALLY SPREAD ISOLATED TO WIDELY SCATTERED
SHOWERS/SPRINKLES EASTWARD IN NORTHERN ILLINOIS NORTH OF
INTERSTATE 80. WEAKER FORCING WITH SOUTHWARD EXTENT AND DRY LOWER
LEVELS NOTED ON 12Z DVN RAOB AND AIRCRAFT SOUNDINGS WILL KEEP
AREAL COVERAGE LOW. MANY AREAS WILL NOT SEE ANY MEASURABLE
RAINFALL GIVEN THE WEAK FORCING AND LOW AREAL COVERAGE. IN
ADDITION...POOR MIDLEVEL LAPSE RATES WILL LIMIT
DESTABILIZATION...WITH ML AND SB CAPE AXIS STAYING WEST OF THE
AREA THROUGH THE AFTERNOON. THERE COULD BE ENOUGH MUCAPE FOR
SLIGHT CHANCE OF THUNDER THIS AFTERNOON MAINLY NORTHWEST OF A
STERLING TO ANTIOCH LINE...THOUGH THIS COULD EVEN END UP BULLISH.
TEMPERATURES FROM INHERITED FORECAST HAVE BEEN TRACKING VERY WELL
WITH HOURLY OBS...SO HIGHS GENERALLY IN THE LOWER 80S APPEAR ON
TRACK...WITH MID 80S POSSIBLE IN CHICAGO HEAT ISLAND AWAY FROM
MINOR COOLING INFLUENCE OF LAKE BREEZE.
RC
&&
.SHORT TERM...
349 AM CDT
THROUGH SUNDAY...
CONCERNS REVOLVE AROUND PRECIPITATION CHANCES EACH OF THE NEXT FEW
DAYS.
A COMPACT BUT POTENT UPPER LEVEL DISTURBANCE IN MN IS PRODUCING A
COMPLEX OF THUNDERSTORMS NOW MOVING INTO WESTERN WISCONSIN. THERE IS
A WEAK SURFACE REFLECTION WITH THIS FEATURE WHERE THE MORE ORGANIZED
ACTIVITY IS ONGOING. CLOSER TO HOME...SURFACE HIGH PRESSURE IS
HOLDING FIRM JUST NEAR LAKE HURON...WITH THE RIDGE AXIS ORIENTED
SOUTHWESTWARD. IR IMAGERY EARLY THIS MORNING HAS SHOWN A CONTINUAL
EROSION OF THE DEEPER CLOUDS ON THE SOUTHERN END OF THIS COMPLEX AS
IT MOVES INTO DRIER AIR FARTHER SOUTH AND EAST.
AN UPPER LEVEL JET MOVING INTO THE NORTHERN PLAINS WILL ALLOW THIS
UPPER DISTURBANCE TO MOVE SOUTH AND EAST TOWARD THE AREA
TODAY...EVEN OUTRUNNING THE SURFACE LOW. MUCH OF THE NEAR TERM
GUIDANCE KEEPS ERODING PRECIP SOUTH OF THE WISCONSIN BORDER AHEAD OF
THIS SYSTEM. THE EXCEPTION TO THIS THE EXPERIMENTAL HRRR AND
SEVERAL HOP-WRF MEMBERS WHICH ARE A BIT MORE AGGRESSIVE WITH
DRIVING PRECIP THROUGH THE AREA...ESPECIALLY THIS AFTERNOON.
OBSERVATIONS SUGGEST SOME CONTINUED DEVELOPMENT SOUTHWARD THROUGH
THE MORNING INTO THE INSTABILITY AXIS WHICH WILL GRADUALLY
APPROACH FROM THE WEST TODAY. HAVE STILL KEPT POPS ON THE LOWER
SIDE AWAY FROM NORTH CENTRAL ILLINOIS AND POINTS WEST...THOUGH
EXPECT OUR NORTHWESTERN ZONES INTO WINNEBAGO/BOONE/MCHENRY
COUNTIES STAND A CHANCE OF SOME SHOWERS OR A STRAY STORM LATER
THIS MORNING INTO THE AFTERNOON. CONTINUED DRY AIR SHOULD FURTHER
ERODE AT THE PRECIP...THOUGH AS THE DAY GOES ON AND THE
INSTABILITY AXIS SHIFTS EASTWARD WITH THE UPPER LOW...EXPECT THAT
SOME SHOWERS WILL BE POSSIBLE. SOUNDINGS ARE NOT THRILLED ABOUT
THE THUNDER POTENTIAL CLOSER TO CHICAGO WITH CAPPING HOLDING.
TONIGHT...THE UPPER LOW SHIFTS EAST AND OUTPACES THE SURFACE LOW AND
THUS EXPECT SOME DECREASE IN COVERAGE OF SHOWERS AND COULD JUST BE
DRY...THOUGH WILL HANG ONTO A LOW POP MENTION OVERNIGHT FOR SOME
LINGERING LOW LEVEL CONVERGENCE.
SATURDAY...FOCUS SHIFTS TO ENERGY PROPAGATING FROM THE TROUGH OFF
THE CA COAST THIS MORNING. THIS IS FORECAST TO RIDE A DECENT UPPER
JET THROUGH THE PLAINS OVERNIGHT INTO THE MORNING AND ALONG THE
NORTHERN FRINGES OF THE UPPER LEVEL RIDGE AXIS THAT EXTENDS FROM
TEXAS NORTH INTO THE CENTRAL PLAINS. THIS WAVE CRUISES THROUGH
SATURDAY MORNING WITH SURFACE HIGH PRESSURE IN PLACE AND A LACK OF
DEEPER MOISTURE...SO HAVE CONTINUED A DRY FORECAST...AND THAT GOES
FOR SATURDAY AFTERNOON AS WELL AS THE WAVE MOVES EAST. WILL HAVE
TO WATCH THE MORNING PERIOD IF THE LOWER LEVELS MOISTEN UP A BIT
MORE THAN FORECAST THAT A STRAY SHOWER OR STORM WOULD BE POSSIBLE.
THE NAM IS A LITTLE SLOWER WITH THIS WAVE...BUT STILL DRY IN THE
AFTERNOON AS THE STRONGER FORCING REMAINS TO OUR WEST.
CHANCES FOR SHOWERS AND STORMS INCREASE SATURDAY NIGHT INTO SUNDAY
MORNING AS WE GET A BETTER CO-LOCATION OF DEEPER MOISTURE TRANSPORT
COURTESY OF A DECENT LOW LEVEL JET...ANOTHER PACIFIC
DISTURBANCE...AND PWATS APPROACHING 2 INCHES. WE HANG ONTO SE FLOW
AT THE SURFACE FARTHER EAST...WHICH WOULD THEN GIVE THE HIGHER
CONCERN FOR MODERATE TO HEAVY PRECIP RATES SOUTH AND WEST. THERE
IS A SEVERE THREAT GIVEN THE MODEST WESTERLY FLOW NORTH OF THE
RIDGE AND HIGHER DEWPOINTS ADVECTING IN...BUT DESTABILIZATION
CONCERNS EXIST AT THIS POINT IN TIME TO NAIL DOWN THE SPECIFICS
YET. THE MARGINAL RISK IS FOCUSED IN OUR SOUTHWEST AT THIS TIME.
KMD
&&
.LONG TERM...
407 AM CDT
SUNDAY NIGHT THROUGH THURSDAY...
.LONG TERM...
AN UPPER LEVEL LOW QUICKLY MOVES EASTWARD THROUGH SOUTHERN ONTARIO SUNDAY
NIGHT INTO MONDAY...AS THIS OCCURS AND A DEEP TROUGH BUILDS ALONG
THE PACIFIC COAST...UPPER LEVEL RIDGING IN THE WEST WILL CONTINUE
TO AMPLIFY THE FLOW PATTERN. NW FLOW ON MONDAY WILL KEEP A CHANCE
FOR SHOWERS AND STORMS AROUND AS A WEAK COLD FRONT MOVES THROUGH.
ANOTHER DISTURBANCE GLIDES BY TO OUR NORTH TUESDAY FOR A SOMEWHAT
COOLER THOUGH GENERALLY DRY DAY. A STRAY SHOWER IS POSSIBLE. HIGH
PRESSURE BUILDS IN FOR MID WEEK.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* LAKE BREEZE POTENTIAL THIS AFTERNOON.
* ISOLATED SHOWERS TONIGHT.
* BRIEF REDUCTION IN VSBY DUE TO FOG SATURDAY MORNING.
MM
//DISCUSSION...UPDATED 18Z...
TERMINAL DOPPLER RADAR INDICATES LAKE BREEZE BOUNDARY MAKING
INROADS TOWARD ORD EARLY THIS AFTERNOON. LOW LEVEL SOUTHWEST WINDS
HAVE BEEN COMBATING THIS WEAK BOUNDARY TODAY...AND IT DOES APPEAR
THAT THE BOUNDARY MAY REMAIN EAST OF ORD. THE RESULT LEAVES PREVAILING
SSW WINDS LIKELY. IF THE BOUNDARY WERE TO PENETRATE FURTHER...IT
WILL LIKELY BE AFTER A FEW MORE HOURS OF DAYTIME HEATING...NEAR
22Z.
OVERNIGHT A NON-STANDARD WARM FRONT WILL APPROACH THE
AREA...PROVIDING FOCUS FOR SOME SCATTERED SHOWERS. TAF SITES WILL
BE IN THE WARM SECTOR OF THE LOW IN THE MORNING WHICH WILL HELP
FORMATION OF FOG IN THE MORNING. THIS FRONT BECOMES NEARLY
STATIONARY EARLY SATURDAY. THE PRESSURE PATTERN WILL FAVOR WEAK
SOUTHERLY WINDS DURING THE DAY...VEERING TO BECOME NORTHWEST IN
THE LATE AFTERNOON. A LAKE BREEZE IS AGAIN POSSIBLE AFTER 22Z.
MM
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM-LOW IN LAKE BREEZE TODAY.
* MEDIUM IN SHOWERS TONIGHT.
* MEDIUM-LOW IN FOG DENSITY.
MM
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...SLIGHT CHANCE OF THUNDERSTORMS.
SUNDAY...CHANCE OF THUNDERSTORMS.
MONDAY...CHANCE OF THUNDERSTORMS.
TUESDAY...VFR.
WEDNESDAY...VFR.
THURSDAY...VFR.
RODRIGUEZ
&&
.MARINE...
302 AM CDT
LIGHTER EASTERLY WINDS IN PLACE EARLY THIS MORNING WILL OBSERVE A
STEADY INCREASE TODAY WHILE SHIFTING TO MORE OF A SOUTHERLY
COMPONENT...AS LOW PRESSURE TO THE WEST OVER THE NORTHERN PLAINS
SLOWLY PUSHES EAST. STILL THINK A 10 TO 20 KT WIND WILL BE THE
HIGHEST TODAY...BUT SOME GUIDANCE IS HINTING AT POSSIBLE HIGHER
SPEEDS THROUGHOUT THE DAY. ALTHOUGH I DID INCREASE SPEEDS...DID
NOT GO AS HIGH. HOWEVER...DID MENTION A FEW GUSTS TO 25KT FOR THE
OPEN WATERS TODAY. IT DOES LOOK LIKE A BETTER WINDOW FOR STRONGER
WINDS OF 15 TO 25 KT ACROSS THE NORTH TONIGHT INTO SATURDAY
MORNING...AND HAVE TRENDED THAT WAY WITH THE FORECAST. THIS WILL
BE IN RESPONSE TO THE APPROACHING LOW...BUT WITH IT
WEAKENING...SPEEDS WILL DIMINISH SATURDAY INTO SATURDAY NIGHT.
EXACT TIMING AND PLACEMENT OF THE NEXT SYSTEM LATE IN THE WEEKEND
IS STILL UNCERTAIN BUT IT DOES APPEAR TO BE ANOTHER PERIOD WHEN
SPEEDS WILL ONCE AGAIN INCREASE...AT LEAST FOR THE SOUTHERN HALF
OF THE LAKE.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1143 AM CDT FRI AUG 7 2015
.UPDATE...
1143 AM CDT
A WEAKENING SURFACE LOW RESIDES OVER FAR WESTERN WISCONSIN...WITH
HIGH PRESSURE CENTERED OVER THE EASTERN AND CENTRAL GREAT LAKES
LATE THIS MORNING. GLANCING BLOW FROM THE MID/UPPER WAVE
ASSOCIATED FROM THE SURFACE LOW THAT IS MAINLY FOCUSED INTO
WISCONSIN WILL GRADUALLY SPREAD ISOLATED TO WIDELY SCATTERED
SHOWERS/SPRINKLES EASTWARD IN NORTHERN ILLINOIS NORTH OF
INTERSTATE 80. WEAKER FORCING WITH SOUTHWARD EXTENT AND DRY LOWER
LEVELS NOTED ON 12Z DVN RAOB AND AIRCRAFT SOUNDINGS WILL KEEP
AREAL COVERAGE LOW. MANY AREAS WILL NOT SEE ANY MEASURABLE
RAINFALL GIVEN THE WEAK FORCING AND LOW AREAL COVERAGE. IN
ADDITION...POOR MIDLEVEL LAPSE RATES WILL LIMIT
DESTABILIZATION...WITH ML AND SB CAPE AXIS STAYING WEST OF THE
AREA THROUGH THE AFTERNOON. THERE COULD BE ENOUGH MUCAPE FOR
SLIGHT CHANCE OF THUNDER THIS AFTERNOON MAINLY NORTHWEST OF A
STERLING TO ANTIOCH LINE...THOUGH THIS COULD EVEN END UP BULLISH.
TEMPERATURES FROM INHERITED FORECAST HAVE BEEN TRACKING VERY WELL
WITH HOURLY OBS...SO HIGHS GENERALLY IN THE LOWER 80S APPEAR ON
TRACK...WITH MID 80S POSSIBLE IN CHICAGO HEAT ISLAND AWAY FROM
MINOR COOLING INFLUENCE OF LAKE BREEZE.
RC
&&
.SHORT TERM...
349 AM CDT
THROUGH SUNDAY...
CONCERNS REVOLVE AROUND PRECIPITATION CHANCES EACH OF THE NEXT FEW
DAYS.
A COMPACT BUT POTENT UPPER LEVEL DISTURBANCE IN MN IS PRODUCING A
COMPLEX OF THUNDERSTORMS NOW MOVING INTO WESTERN WISCONSIN. THERE IS
A WEAK SURFACE REFLECTION WITH THIS FEATURE WHERE THE MORE ORGANIZED
ACTIVITY IS ONGOING. CLOSER TO HOME...SURFACE HIGH PRESSURE IS
HOLDING FIRM JUST NEAR LAKE HURON...WITH THE RIDGE AXIS ORIENTED
SOUTHWESTWARD. IR IMAGERY EARLY THIS MORNING HAS SHOWN A CONTINUAL
EROSION OF THE DEEPER CLOUDS ON THE SOUTHERN END OF THIS COMPLEX AS
IT MOVES INTO DRIER AIR FARTHER SOUTH AND EAST.
AN UPPER LEVEL JET MOVING INTO THE NORTHERN PLAINS WILL ALLOW THIS
UPPER DISTURBANCE TO MOVE SOUTH AND EAST TOWARD THE AREA
TODAY...EVEN OUTRUNNING THE SURFACE LOW. MUCH OF THE NEAR TERM
GUIDANCE KEEPS ERODING PRECIP SOUTH OF THE WISCONSIN BORDER AHEAD OF
THIS SYSTEM. THE EXCEPTION TO THIS THE EXPERIMENTAL HRRR AND
SEVERAL HOP-WRF MEMBERS WHICH ARE A BIT MORE AGGRESSIVE WITH
DRIVING PRECIP THROUGH THE AREA...ESPECIALLY THIS AFTERNOON.
OBSERVATIONS SUGGEST SOME CONTINUED DEVELOPMENT SOUTHWARD THROUGH
THE MORNING INTO THE INSTABILITY AXIS WHICH WILL GRADUALLY
APPROACH FROM THE WEST TODAY. HAVE STILL KEPT POPS ON THE LOWER
SIDE AWAY FROM NORTH CENTRAL ILLINOIS AND POINTS WEST...THOUGH
EXPECT OUR NORTHWESTERN ZONES INTO WINNEBAGO/BOONE/MCHENRY
COUNTIES STAND A CHANCE OF SOME SHOWERS OR A STRAY STORM LATER
THIS MORNING INTO THE AFTERNOON. CONTINUED DRY AIR SHOULD FURTHER
ERODE AT THE PRECIP...THOUGH AS THE DAY GOES ON AND THE
INSTABILITY AXIS SHIFTS EASTWARD WITH THE UPPER LOW...EXPECT THAT
SOME SHOWERS WILL BE POSSIBLE. SOUNDINGS ARE NOT THRILLED ABOUT
THE THUNDER POTENTIAL CLOSER TO CHICAGO WITH CAPPING HOLDING.
TONIGHT...THE UPPER LOW SHIFTS EAST AND OUTPACES THE SURFACE LOW AND
THUS EXPECT SOME DECREASE IN COVERAGE OF SHOWERS AND COULD JUST BE
DRY...THOUGH WILL HANG ONTO A LOW POP MENTION OVERNIGHT FOR SOME
LINGERING LOW LEVEL CONVERGENCE.
SATURDAY...FOCUS SHIFTS TO ENERGY PROPAGATING FROM THE TROUGH OFF
THE CA COAST THIS MORNING. THIS IS FORECAST TO RIDE A DECENT UPPER
JET THROUGH THE PLAINS OVERNIGHT INTO THE MORNING AND ALONG THE
NORTHERN FRINGES OF THE UPPER LEVEL RIDGE AXIS THAT EXTENDS FROM
TEXAS NORTH INTO THE CENTRAL PLAINS. THIS WAVE CRUISES THROUGH
SATURDAY MORNING WITH SURFACE HIGH PRESSURE IN PLACE AND A LACK OF
DEEPER MOISTURE...SO HAVE CONTINUED A DRY FORECAST...AND THAT GOES
FOR SATURDAY AFTERNOON AS WELL AS THE WAVE MOVES EAST. WILL HAVE
TO WATCH THE MORNING PERIOD IF THE LOWER LEVELS MOISTEN UP A BIT
MORE THAN FORECAST THAT A STRAY SHOWER OR STORM WOULD BE POSSIBLE.
THE NAM IS A LITTLE SLOWER WITH THIS WAVE...BUT STILL DRY IN THE
AFTERNOON AS THE STRONGER FORCING REMAINS TO OUR WEST.
CHANCES FOR SHOWERS AND STORMS INCREASE SATURDAY NIGHT INTO SUNDAY
MORNING AS WE GET A BETTER CO-LOCATION OF DEEPER MOISTURE TRANSPORT
COURTESY OF A DECENT LOW LEVEL JET...ANOTHER PACIFIC
DISTURBANCE...AND PWATS APPROACHING 2 INCHES. WE HANG ONTO SE FLOW
AT THE SURFACE FARTHER EAST...WHICH WOULD THEN GIVE THE HIGHER
CONCERN FOR MODERATE TO HEAVY PRECIP RATES SOUTH AND WEST. THERE
IS A SEVERE THREAT GIVEN THE MODEST WESTERLY FLOW NORTH OF THE
RIDGE AND HIGHER DEWPOINTS ADVECTING IN...BUT DESTABILIZATION
CONCERNS EXIST AT THIS POINT IN TIME TO NAIL DOWN THE SPECIFICS
YET. THE MARGINAL RISK IS FOCUSED IN OUR SOUTHWEST AT THIS TIME.
KMD
&&
.LONG TERM...
407 AM CDT
SUNDAY NIGHT THROUGH THURSDAY...
.LONG TERM...
AN UPPER LEVEL LOW QUICKLY MOVES EASTWARD THROUGH SOUTHERN ONTARIO SUNDAY
NIGHT INTO MONDAY...AS THIS OCCURS AND A DEEP TROUGH BUILDS ALONG
THE PACIFIC COAST...UPPER LEVEL RIDGING IN THE WEST WILL CONTINUE
TO AMPLIFY THE FLOW PATTERN. NW FLOW ON MONDAY WILL KEEP A CHANCE
FOR SHOWERS AND STORMS AROUND AS A WEAK COLD FRONT MOVES THROUGH.
ANOTHER DISTURBANCE GLIDES BY TO OUR NORTH TUESDAY FOR A SOMEWHAT
COOLER THOUGH GENERALLY DRY DAY. A STRAY SHOWER IS POSSIBLE. HIGH
PRESSURE BUILDS IN FOR MID WEEK.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* LAKE BREEZE TO EAST/SOUTHEAST WINDS THIS AFTERNOON.
* SLIGHT CHANCE OF SHOWERS THIS AFTERNOON INTO THE EVENING.
MM
//DISCUSSION...UPDATED 12Z...
VFR CONDITIONS PERSISTING THIS MORNING WHILE SOUTH/SOUTHEAST
WINDS STEADILY INCREASE. VFR CONDITIONS ARE STILL EXPECTED FOR
MOST OF THE FORECAST PERIOD. HOWEVER...THE POTENTIAL FOR SCATTERED
SHOWERS IS INCREASING AND BECOMING SOONER THAN PREVIOUSLY
EXPECTED. ALTHOUGH THE HIGHEST CHANCES FOR PRECIP WILL STAY TO
THE NORTH...AT LEAST SCATTERED DEVELOPMENT IS NOW POSSIBLE THIS
AFTERNOON INTO THE EARLY EVENING. INSTABILITY DOES NOT APPEAR TO
BE THE GREATEST...AND SO THINK THE LIKELIHOOD OF THUNDER IS LOW AT
THIS TIME. LAKE BREEZE PUSH IS STILL APPEARING TO BE LIKELY THIS
AFTERNOON...WITH EAST SOUTHEAST WINDS AT OR ABOVE 10KT EXPECTED
LATER THIS AFTERNOON.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* MEDIUM CONFIDENCE FOR WINDS/LAKE BREEZE TODAY.
* MEDIUM CONFIDENCE FOR ISOLATED SHOWERS.
MM
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...SLIGHT CHANCE OF THUNDERSTORMS.
SUNDAY...CHANCE OF THUNDERSTORMS.
MONDAY...CHANCE OF THUNDERSTORMS.
TUESDAY...VFR.
WEDNESDAY...VFR.
THURSDAY...VFR.
RODRIGUEZ
&&
.MARINE...
302 AM CDT
LIGHTER EASTERLY WINDS IN PLACE EARLY THIS MORNING WILL OBSERVE A
STEADY INCREASE TODAY WHILE SHIFTING TO MORE OF A SOUTHERLY
COMPONENT...AS LOW PRESSURE TO THE WEST OVER THE NORTHERN PLAINS
SLOWLY PUSHES EAST. STILL THINK A 10 TO 20 KT WIND WILL BE THE
HIGHEST TODAY...BUT SOME GUIDANCE IS HINTING AT POSSIBLE HIGHER
SPEEDS THROUGHOUT THE DAY. ALTHOUGH I DID INCREASE SPEEDS...DID
NOT GO AS HIGH. HOWEVER...DID MENTION A FEW GUSTS TO 25KT FOR THE
OPEN WATERS TODAY. IT DOES LOOK LIKE A BETTER WINDOW FOR STRONGER
WINDS OF 15 TO 25 KT ACROSS THE NORTH TONIGHT INTO SATURDAY
MORNING...AND HAVE TRENDED THAT WAY WITH THE FORECAST. THIS WILL
BE IN RESPONSE TO THE APPROACHING LOW...BUT WITH IT
WEAKENING...SPEEDS WILL DIMINISH SATURDAY INTO SATURDAY NIGHT.
EXACT TIMING AND PLACEMENT OF THE NEXT SYSTEM LATE IN THE WEEKEND
IS STILL UNCERTAIN BUT IT DOES APPEAR TO BE ANOTHER PERIOD WHEN
SPEEDS WILL ONCE AGAIN INCREASE...AT LEAST FOR THE SOUTHERN HALF
OF THE LAKE.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION...CORRECTED
NWS NORTHERN INDIANA
412 PM EDT FRI AUG 7 2015
.SYNOPSIS...
ISSUED AT 410 PM EDT FRI AUG 7 2015
AN UPPER LEVEL DISTURBANCE TRACKING ACROSS THE GREAT LAKES TONIGHT
MAY BRING ISOLATED SHOWERS TO PORTIONS OF EXTREME NORTHERN INDIANA
AND SOUTHERN LOWER MICHIGAN THROUGH SATURDAY MORNING. MOST AREAS
WILL REMAIN DRY THROUGH SATURDAY...BUT CLOUDS WILL BE ON THE
INCREASE. LOW TEMPERATURES TONIGHT WILL RANGE FROM THE UPPER 50S TO
LOWER 60S. HIGH TEMPERATURES ON SATURDAY CAN BE EXPECTED TO REACH
BACK AROUND THE 80 DEGREE MARK.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 410 PM EDT FRI AUG 7 2015
A COMPACT UPPER LEVEL SHORT WAVE WILL CONTINUE EASTWARD ACROSS
THE WESTERN GREAT LAKES THIS EVENING...ALTHOUGH LATEST SHORT TERM
TRENDS SEEM TO SUGGEST THIS SHORT WAVE IS BECOMING INCREASINGLY
SHEARED. A LARGE AREA OF SHOWERS WITH A FEW EMBEDDED THUNDERSTORMS
IS ACCOMPANYING THIS VORT. SHORT TERM RAP TRENDS SUGGEST THIS WAVE
WILL BECOMING INCREASINGLY SHEARED WITH A MORE NARROWED CHANNEL OF
DPVA WORKING FROM WEST TO EAST ACROSS THE LOCAL AREA IN THE 22Z-
04Z TIMEFRAME. LOW LEVEL THETAE TROUGH CURRENTLY RESIDING ACROSS
THE AREA IS PROVIDING A FAIRLY SHARP WEST-EAST INSTABILITY
GRADIENT FROM THE MID MS VALLEY TO THE OHIO VALLEY...AND WOULD
EXPECT SOME DIMINISHING TREND IN COVERAGE AS THIS WAVE LOSES SOME
POTENCY AND DUE TO EFFECTS OF INITIALLY DRY AIR MASS ACROSS THE
REGION. HAVE MAINTAINED SOME SLIGHT CHANCE POPS PARTICULARLY
ACROSS THE FAR NORTHWEST/NORTH THIS EVENING FOLLOWING THIS
FORCING...WITH MORE QUESTIONABLE MOISTURE RETURN ACROSS REMAINDER
OF THE AREA ARGUING FOR MAINTENANCE OF DRY FORECAST.
FORCING WITH THIS WAVE WILL WANE LATE EVENING...BUT LAGGING LOW
LEVEL THETAE RIDGE MAY BEGIN TO HAVE SOME INFLUENCE OVERNIGHT INTO
EARLY SATURDAY MORNING. HAVE OPTED TO KEEP SOME SLIGHT CHANCE POPS
GOING OVERNIGHT INTO EARLY SATURDAY MORNING ACROSS THE
NORTH/NORTHWEST DUE TO LINGERING ADVECTIVE FORCING AND APPROACH OF A
VERY WEAK REMNANT SFC TROUGH. SOME EASTWARD PROGRESSION OF DAMPENED
LOW LEVEL THERMAL RIDGING ON SATURDAY SHOULD SOMEWHAT OFFSET
EXPECTED MORE CLOUD COVER ON SATURDAY FOR HIGHS ONCE AGAIN AROUND
80...OR POSSIBLY INTO THE LOWER 80S DEPENDING ON EXTENT OF CLOUD
COVER.
&&
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 410 PM EDT FRI AUG 7 2015
AN UPPER LEVEL SYSTEM OVER THE WESTERN CONUS WILL EJECT AN
UPPER LEVEL TROF OVER THE LARGE UPPER LEVEL SOUTHERN PLAINS RIDGE
AND THEN THE TROF WILL MOVE INTO THE UPPER GREAT LAKES REGION BY
EARLY SUNDAY. NCEP MODELS...THE CANADIAN GEM AND THE ECMWF WERE
SHOWING LARGE DIFFERENCES IN HANDLING THIS SYSTEM. FAVOR A
SOUTHERN TRACK WHICH IS SUPPORTED THE BY ECMWF AND THE CPS
ANALOGS. ALSO...MOST MODELS TRACKED THE SYSTEM EARLIER THIS WEEK
TOO FAR NORTH. SO FOR THIS PACKAGE...KEPT A CHANCE FOR STORMS
SUNDAY. HOWEVER...INCREASED STORM CHANCES A LITTLE OVER SOUTHWEST
AREAS IN DEFERENCE TO THE ECMWF. IF THE SOUTHERN TRACK
VERIFIES...CHANCES FOR SEVERE STORMS SHOULD BE LIMITED MORE TO THE
SOUTH AND SOUTHWEST. OTHERWISE...SOME LINGERING SHOWERS AND STORMS
ARE POSSIBLE MONDAY AND THEN CONDITIONS SHOULD BE DRY WITH
TEMPERATURES A LITTLE BELOW NORMAL AS A LARGE UPPER LEVEL TROF
REMAINS OVER THE AREA NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 410 PM EDT FRI AUG 7 2015
(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 555 AM EDT FRI AUG 7 2015
SOME WEAK LOW LEVEL WARM/MOIST ADVECTION WILL COMMENCE LATE THIS
EVENING/TONIGHT ACROSS NORTHWEST INDIANA/SOUTHWEST LOWER MICHIGAN.
A SMALL SCALE BUT FAIRLY STRONG VORT MAX TRACKING OUT OF CENTRAL
WISCONSIN COMBINED WITH ADVECTIVE FORCING MAY BE ENOUGH FOR A FEW
SHOWERS MOVING INTO PORTIONS OF NORTHWEST INDIANA THIS EVENING.
GREATER PROBABILITIES OF AN ISOLATED SHOWER WILL LIKELY REMAIN
NORTH OF KSBN SO WILL MAINTAIN A DRY FORECAST FOR SNOW. THE
INITIALLY DRY SUBCLOUD LAYER WILL ALLOW FOR MAINTENANCE OF VFR
CONDITIONS THROUGH THIS PERIOD...WITH ANY PATCHY SHALLOW FOG
FORMATION EARLY SATURDAY MORNING NOT LIKELY TO AFFECT TERMINALS.
EAST/SOUTHEAST WINDS TODAY WILL VEER SOUTHERLY FOR SATURDAY WITH
SPEEDS UNDER 10 KNOTS CONTINUING.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...MARSILI
SHORT TERM...MARSILI
LONG TERM...SKIPPER
AVIATION...MARSILI
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AREA FORECAST DISCUSSION
NWS GOODLAND KS
335 PM MDT FRI AUG 7 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 159 PM MDT FRI AUG 7 2015
BIGGEST CHALLENGE IN SHORT TERM IS THUNDERSTORM POTENTIAL THIS
AFTERNOON AND OVERNIGHT. NUMEROUS RUNS OF THE RAP PERSIST IN
BREAKING OUT SCATTERED AFTERNOON CONVECTION ACROSS THE CENTRAL
AND NORTHEAST COUNTIES...GENERALLY IN THE VICINITY OF A VERY WEAK
DECAYING SURFACE BOUNDARY. HAVE SOME DOUBTS ABOUT THIS LOOKING AT
CURRENT SATELLITE TRENDS AND SPC MESOANALYSIS CINH...BUT HAVE LEFT
THE SLIGHT CHANCE POPS NONETHELESS.
BIGGER ISSUE IS DEVELOPMENT OF STORMS OVER COLORADO LATER THIS
AFTERNOON AND THEIR SUBSEQUENT MOVEMENT. WATER VAPOR IMAGERY
SHOWS THE APPROACH OF THE NEXT UPSTREAM SHORTWAVE TROUGH AND RADAR
NOW SHOWS INITIAL THUNDERSTORM DEVELOPMENT SOUTH OF DENVER. MOST
GUIDANCE...INCLUDING THE CONVECTION-ALLOWING MODELS...INDICATES
BEST COVERAGE OF STORMS WILL BE ACROSS NORTHEAST COLORADO INTO
SOUTHWEST NEBRASKA...CLIPPING NORTHWEST KANSAS WITH LESSER
COVERAGE SOUTH AND EAST. ULTIMATELY IT DEPENDS ON UPSCALE
DEVELOPMENT AND WHETHER OR NOT A DECENT MCS CAN DEVELOP AND
PRODUCE STORMS FURTHER SOUTHEAST OF THE MAIN SHORTWAVE. HAVE
CONTINUED THE PREVIOUS FORECAST TREND OF BEST COVERAGE NORTH AND
NORTHWEST WITH LESSER POTENTIAL SOUTH OF I-70.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 334 PM MDT FRI AUG 7 2015
FORECAST PROBLEM WILL BE THUNDERSTORM CHANCES AND ANY HEAVY
RAINFALL THREAT. SATELLITE IS SHOWING AN AMPLIFIED AND MOSTLY
PROGRESSIVE FLOW FROM THE PACIFIC INTO NORTH AMERICA. THIS FLOW
BECOMES MORE OF A SPLIT WITH THE TROUGHS ALONG THE WEST AND EAST
COASTS. A LOT OF PACIFIC AND MONSOONAL MOISTURE IS BEING PULLED UP
INTO THE REGION. CURRENTLY A SYNOPTIC BOUNDARY REMAINS DRAPED TO
OUR SOUTH AND WEST.
AT JET LEVEL...MODELS STARTED OUT FINE. AT MID LEVELS...MODELS WERE
NOT TOO FAR APART. THE CANADIAN/UKMET/GFS LED THE PACK WITH OTHERS
NOT FAR BEHIND WITH THE SREF THE WORST. THE NAM/SREF WERE HANLDING
THE SURFACE WIND AND PRESSURE FIELD THE BEST. MODELS TENDED TO BE A
LITTLE COOL ON THE LOW LEVEL THERMAL FIELD WITH THE GFS/CANADIAN
DOING THE BEST.
SATURDAY NIGHT...TO BEGIN THE NIGHT...SURFACE BOUNDARY IS DRAPED
OVER THE FAR SOUTH AND WEST CENTRAL PORTION OF THE AREA. THIS
BOUNDARY GRADUALLY SINKS SOUTH THROUGH THE NIGHT. SHORTWAVE TROUGH
MOVES THROUGH FROM THE SOUTHWEST THROUGH THE NIGHT WITH THE BEST
LIFT BASICALLY OVER THE SOUTHWEST HALF. MAIN JET AXIS/LIFT STAYS NOT
TOO FAR TO OUR NORTH AND WEST THROUGH MOST OF THE PERIOD. LATE IN
THE NIGHT A RIGHT REAR QUADRANT GETS CLOSER TO THE NORTHWEST PORTION.
RIGHT NOW THE HIGHEST POPS LOOK TO BE IN THE SOUTHWEST HALF. PWS
REMAIN NEAR 1.5 INCHES. THAT WITH STORM MOTIONS ONLY 10 TO 15 KNOTS
ALONG THAT FLOW COMING OVER THE TOP OF THE SOUTHERN BOUNDARY WILL
MAKE MODERATE TO LOCALLY HEAVY RAINFALL POSSIBLE. ALSO POSSIBLE LATE
IN THE NIGHT WITH MOIST LOW LEVELS AND LITTLE TO NO WIND THAT PATCHY
FOG COULD DEVELOP WHERE NO PRECIPITATION IS GOING ON.
SUNDAY/SUNDAY NIGHT...IT LOOKS LIKE THERE MAY BE SOME LINGERING
RAINFALL AND PATCHY FOG IN THE MORNING. FOR THE REMAINDER OF THE
PERIOD...BOUNDARY LOOKS TO BE TO THE SOUTH AND WEST OF THE AREA WITH
A WEAK LOW LEVEL UPSLOPE REGIME IN PLACE. HOWEVER...MODELS ARE
HINTING AT A WEAK SECONDARY BOUNDARY MOVING INTO THE NORTHWEST HALF
OF THE AREA DURING THE LATE AFTERNOON INTO THE EVENING. THIS SINKS A
LITTLE FURTHER SOUTHEAST DURING THE LAST HALF OF THE NIGHT.
THE MID LEVEL FORCING THROUGH THE PERIOD REMAINS RATHER WEAK WITH
THE STRONGEST IN THE EVENING. RIGHT REAR QUADRANT OF THE JET REMAINS
NEAR THE NORTHERN AND WESTERN PORTIONS OF THE AREA THROUGH THE DAY
BUT GETS CLOSER/HAS MORE AFFECT ON THOSE LOCATIONS BY THE END OF THE
DAY. THE NORTHERN PORTION OF THE AREA KEEPS GETTING AFFECTED BY THIS
THROUGH THE MIDDLE OF THE NIGHT. WITH A VARIETY OF FORCING IN
DIFFERENT TIMES AND PLACES...WILL BROADBRUSH CHANCE POPS FOR THE
ENTIRE NIGHT.
FOR THE HIGH TEMPERATURES...WILL HAVE LOW LEVEL UPSLOPE IN PLACE
THROUGH THE DAY ALONG WITH LINGERING CLOUD COVER IN THE MORNING AND
DEVELOPING CLOUD COVER IN THE AFTERNOON WITH THE CONVECTION. MODEL
GUIDANCE HAS TENDED TO BE A LITTLE WARM.
MONDAY...JET REMAINS WELL NORTH OF THE AREA THROUGH THE DAY. MID
LEVEL SHORTWAVE RIDGE IS IN PLACE THROUGH THE DAY WITH A LOT OF
DRYING. A SHORTWAVE TROUGH STARTS GETTING CLOSER DURING THE END OF
THE DAY. AREA IS IN A POST FRONTAL AIR MASS. DEPENDING ON WHICH
MODEL YOU USE...THERE COULD BE A WEAK SUBTLE SURFACE BOUNDARY IN THE
FAR SOUTH/SOUTHWEST. SO AT THIS TIME...WILL HAVE SLIGHT TO LOW
CHANCE POPS IN THE FAR SOUTH AND SOUTHWEST PORTION OF THE AREA IN
THE AFTERNOON.
HIGH TEMPERATURES WILL BE COOLER THAN THE PREVIOUS DAY DUE TO LOWER
850 MB TEMPERATURES...UPSLOPE WINDS AND LINGERING MORNING FOG/STRATUS
THAT BEGINS SUNDAY NIGHT.
MONDAY NIGHT THROUGH SATURDAY...CONTINUED AMPLIFIED PATTERN
REMAINS IN PLACE THROUGH THE PERIOD. HOWEVER...THE DETERMINISTIC
AND ENSEMBLE OUTPUT SPREAD GETS WORSE WITH TIME...ALMOST
COMPLETELY OUT OF PHASE AT TIMES. THE DIFFERENCES INVOLVE HOW THE
PERSISTENT SOUTHERN UNITED STATES RIDGE AND WEST TROUGH EVOLVE
WITH TIME. IN GENERAL THE ECMWF REMAINS STRONGER WITH THE RIDGE.
FOR THE WESTERN TROUGH...ALL OUTPUT SUPPORTS A DEEPENING ALONG THE
COAST UPPER TROUGH.
DESPITE THOSE DIFFERENCES...THE CENTER OF THE RIDGE...STILL RATHER
FAR SOUTH...AND THE POSITION OF THE UPPER TROUGH SHOULD CONTINUE TO
ALLOW PACIFIC AND MONSOONAL MOISTURE TO PULLED UP INTO THE REGION
WITH PERIODIC SHORTWAVE TROUGHS EMBEDDED WITHIN THIS FLOW. AT THE
SURFACE...WPC GRAPHICS SHOW A PERSISTENT FRONTAL BOUNDARY STILL
DRAPED NOT TOO FAR TO OUR SOUTH AND WEST OR OVER THE AREA. THIS
KEEPS A CONTINUED UPSLOPE FLOW OVER THE AREA.
GIVEN THE BIG MODEL DIFFERENCES...THE GENERAL PATTERN SUPPORTED
CONTINUED BOUTS OF MOISTURE/LIFT/RAINFALL...AND THE PROXIMITY OF A
BOUNDARY AND UPSLOPE FLOW...SHOULD SEE A CONTINUED THREAT FOR
THUNDERSTORMS AND DO NOT FEEL COMFORTABLE MAKING ANY MAJOR
ADJUSTMENTS TO THE GUIDANCE. THE DETAILS WILL HAVE TO BE REFINED AS
WE GET CLOSER TO EACH EVENT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1139 AM MDT FRI AUG 7 2015
VFR WITH STRENGTHENING SOUTHEAST WINDS THIS AFTERNOON AT BOTH
TERMINALS. A FEW SCATTERED STORMS WILL BE POSSIBLE NEAR KMCK BY
MID-AFTERNOON...BUT A WEATHER SYSTEM ALOFT MOVING UP FROM THE
SOUTHWEST WILL HELP INITIATE THE MAIN ROUND OF THUNDERSTORMS THIS
EVENING...GENERALLY IN THE 01Z-06Z TIME FRAME. HEAVY RAINFALL...LARGE
HAIL AND STRONG WINDS WILL ACCOMPANY STRONGER STORMS. POTENTIAL
ONCE AGAIN FOR FOG/STRATUS AT KMCK TOWARD SUNRISE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DLF
LONG TERM...BULLER
AVIATION...DLF
AREA FORECAST DISCUSSION
NWS GOODLAND KS
200 PM MDT FRI AUG 7 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 159 PM MDT FRI AUG 7 2015
BIGGEST CHALLENGE IN SHORT TERM IS THUNDERSTORM POTENTIAL THIS
AFTERNOON AND OVERNIGHT. NUMEROUS RUNS OF THE RAP PERSIST IN
BREAKING OUT SCATTERED AFTERNOON CONVECTION ACROSS THE CENTRAL
AND NORTHEAST COUNTIES...GENERALLY IN THE VICINITY OF A VERY WEAK
DECAYING SURFACE BOUNDARY. HAVE SOME DOUBTS ABOUT THIS LOOKING AT
CURRENT SATELLITE TRENDS AND SPC MESOANALYSIS CINH...BUT HAVE LEFT
THE SLIGHT CHANCE POPS NONETHELESS.
BIGGER ISSUE IS DEVELOPMENT OF STORMS OVER COLORADO LATER THIS
AFTERNOON AND THEIR SUBSEQUENT MOVEMENT. WATER VAPOR IMAGERY
SHOWS THE APPROACH OF THE NEXT UPSTREAM SHORTWAVE TROUGH AND RADAR
NOW SHOWS INITIAL THUNDERSTORM DEVELOPMENT SOUTH OF DENVER. MOST
GUIDANCE...INCLUDING THE CONVECTION-ALLOWING MODELS...INDICATES
BEST COVERAGE OF STORMS WILL BE ACROSS NORTHEAST COLORADO INTO
SOUTHWEST NEBRASKA...CLIPPING NORTHWEST KANSAS WITH LESSER
COVERAGE SOUTH AND EAST. ULTIMATELY IT DEPENDS ON UPSCALE
DEVELOPMENT AND WHETHER OR NOT A DECENT MCS CAN DEVELOP AND
PRODUCE STORMS FURTHER SOUTHEAST OF THE MAIN SHORTWAVE. HAVE
CONTINUED THE PREVIOUS FORECAST TREND OF BEST COVERAGE NORTH AND
NORTHWEST WITH LESSER POTENTIAL SOUTH OF I-70.
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 235 AM MDT FRI AUG 7 2015
AN UPPER LEVEL RIDGE WILL BE IN PLACE OVER THE TRI STATE AREA TO
START OFF THE LONG TERM PERIOD MONDAY. THE CENTRAL AREA OF HIGH
PRESSURE WILL CONTINUE TO RETROGRADE AND INCREASE IN AMPLITUDE OVER
THE ROCKY MOUNTAIN RANGE AND THE NORTHERN PLAINS TUESDAY. WITH THE
PRESENCE OF THE UPPER RIDGE...JET AREAS AND POCKETS OF VORTICITY
WILL REMAIN WELL AWAY FROM THE TRI STATE AREA...WHICH WILL BRING
UPPER STABILITY FOR THE REST OF THE FORECAST PERIOD.
AT THE SURFACE...A COLD FRONT WILL MOVE THROUGH THE FORECAST AREA
MONDAY AND BRING COOLER THAN NORMAL TEMPERATURES IN THE MIDDLE 80S.
THE FRONT WILL STALL OUT SOMEWHERE ALONG THE SOUTHERN EDGES OF THE
FORECAST AREA...SO CHANCES FOR SHOWERS AND THUNDERSTORMS WILL BE
GREATEST THERE MONDAY AFTERNOON AND EVENING WITH SURFACE CONVERGENCE
AND SOME INSTABILITY ALOFT. MODEL SOUNDINGS SHOW PLENTY OF MOIST
AIR WITH PRECIPITABLE WATER VALUES BETWEEN 1 AND 1.5...SO ANY
DEVELOPING STORMS COULD BRING SOME HEAVY DOWNPOURS AT TIMES.
SURFACE SOUTHERLY FLOW AND WARM AIR ADVECTION RETURNS TUESDAY
THROUGH THE REST OF THE PERIOD AS THE FORMER SURFACE COLD FRONT
DISSOLVES. ALTHOUGH THE UPPER LEVEL HIGH WILL BE POSITIONED RIGHT
OVER THE FORECAST AREA...A SURFACE TROUGH IN EASTERN COLORADO IN
COMBINATION WITH THE PRESENCE OF A DRY LINE IN THE AFTERNOON HOURS
COULD BRING SOME CHANCES FOR THUNDERSTORM DEVELOPMENT. MODEL
SOUNDINGS SHOW THAT SURFACE HEATING MAY NOT BE ENOUGH TO BREAK CAP
IN PLACE...BUT ANY FORCING PROVIDED IN AREAS OF UPSLOPE FLOW OR
ALONG THE DRY LINE MAY PRODUCE SOME STRONGER THUNDERSTORMS. NOT
THINKING SEVERE STORMS WILL BE WIDESPREAD DUE TO THE LACK OF JET OR
BULK SHEAR VALUES IN PLACE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1139 AM MDT FRI AUG 7 2015
VFR WITH STRENGTHENING SOUTHEAST WINDS THIS AFTERNOON AT BOTH
TERMINALS. A FEW SCATTERED STORMS WILL BE POSSIBLE NEAR KMCK BY
MID-AFTERNOON...BUT A WEATHER SYSTEM ALOFT MOVING UP FROM THE
SOUTHWEST WILL HELP INITIATE THE MAIN ROUND OF THUNDERSTORMS THIS
EVENING...GENERALLY IN THE 01Z-06Z TIME FRAME. HEAVY RAINFALL...LARGE
HAIL AND STRONG WINDS WILL ACCOMPANY STRONGER STORMS. POTENTIAL
ONCE AGAIN FOR FOG/STRATUS AT KMCK TOWARD SUNRISE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DLF
LONG TERM...MK
AVIATION...DLF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
315 PM EDT FRI AUG 7 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 254 PM EDT FRI AUG 7 2015
A SHORTWAVE HAS UNDERCUT THE UPPER RIDGE OVER THE UPPER MISSISSIPPI
VALLEY AND IS NOW DIVING SOUTHEAST ACROSS EASTERN WISCONSIN. THAT
WAVE IS SUPPORTING THE SHOWERS AND A FEW EMBEDDED THUNDERSTORMS
MOVING ACROSS THAT AREA. FARTHER TO THE WEST...A 1008MB SURFACE LOW
IS LOCATED NEAR EAU CLAIRE WISCONSIN. TO THE NORTHEAST OF THE
SURFACE LOW...AN AREA OF SHOWERS ARE MOVING EAST ACROSS UPPER
MICHIGAN AT THIS TIME...TIED TO THE NORTHERN EDGE OF THE 850-700MB Q-
VECTOR CONVERGENCE AND BROAD WARM AIR ADVECTION. THE HEAVIEST RAIN
SO FAR TODAY HAS FALLEN OVER THE WESTERN HALF OF THE U.P....WITH 0.5
TO 0.65 INCHES OF RAIN FALLING OVER THE BARAGA PLAINS TODAY. AMOUNTS
DIMINISH TO A TENTH OF AN INCH THROUGH 2PM FROM NEGAUNEE SOUTH TO
IRON MOUNTAIN AND EVEN LESS FARTHER TO THE EAST.
THE SURFACE LOW AND SHORTWAVE WILL SLOWLY DISSIPATE AS THEY MOVE TO
THE EAST-SOUTHEAST TONIGHT...LIMITING THE INFLUENCE OF BOTH FEATURES
THROUGH THE NIGHT. EXPECT THE SHOWERS TO DIMINISH AND DRIFT TO THE
SOUTHEAST THROUGH THE EVENING (TIED TO THE 850-700MB Q-VECTOR
CONVERGENCE)...AND LARGELY BE OUT OF THE CWA AROUND 06Z. BUT WITH
THE MODELS CONTINUING TO SHOW LOW LEVEL MOISTURE PIVOTING TO THE
NORTHWEST ON THE NORTHEAST SIDE OF THE 925-850 TROUGH IN
CENTRAL/NORTHERN WISCONSIN...EXPECT ABUNDANT LOW CLOUDS TO BE IN
PLACE ACROSS THE AREA. THESE LOW CLOUDS CAN ALREADY BE SEEN OVER
EASTERN MINNESOTA AND WESTERN WISCONSIN...AND THEY HAVE BEEN WORKING
INTO WESTERN UPPER MICHIGAN THROUGH THE DAY. THINK DRYING AND
INCREASING SUBSIDENCE ABOVE THAT...GENERALLY ABOVE 750MB OVER THE
WEST...WILL ALSO HELP THE DIMINISHMENT OF THE WIDESPREAD SHOWERS.
DID HOLD ONTO THE SHOWERS A LITTLE LONGER OVER THE HIGHER TERRAIN
UPSLOPE AREAS IN CENTRAL UPPER MICHIGAN DUE TO THE FAVORABLY
SOUTHEASTERLY FLOW...BUT THE PRECIPITATION MAY FALL MORE AS DRIZZLE
THAN RAIN. IN ADDITION...HAVE TRENDED FOG UP TO AREAS TO WIDESPREAD
VALUES OVER THE WEST/CENTRAL U.P. WHERE THE BETTER RAIN HAS FALLEN
AND TIED TO THE LOWEST 5KFT BEING SATURATED ON THE NAM/GFS
SOUNDINGS. ONE ITEM TO WATCH...THE LATEST RAP RUNS HAVE BEEN HOLDING
ONTO DRIER NEAR SURFACE AIR OVER THE NORTH CENTRAL...WHICH WOULD
GREATLY REDUCE THE POTENTIAL FOR LOW CLOUDS AND FOG.
EXPECT THE LOW LEVEL MOISTURE TO HOLD ON THROUGH THE FIRST HALF OF
SATURDAY OVER THE WESTERN HALF TO TWO-THIRDS OF THE U.P. BEFORE THE
CONTINUED SUBSIDENCE AND INFLUX OF DRIER AIR TRIES TO BREAK OF THE
CLOUDS. WHILE THAT SHOULD RAISE THE CEILINGS ACROSS THE AREA...STILL
EXPECT THE WESTERN CWA TO REMAIN MOSTLY CLOUDY...WHILE THE EASTERN
THIRD OF THE U.P. WILL EXPERIENCE LINGERING MID CLOUDS IN THE
MORNING...TRANSITIONING TO DIURNAL CU IN THE AFTERNOON.
CONTINUED TO SHOW SLIGHT CHANCE POPS MOVING INTO WESTERN LAKE
SUPERIOR AND FAR WESTERN UPPER MICHIGAN TOMORROW AFTERNOON...AHEAD
OF THE SURFACE TROUGH MOVING INTO NORTHERN MINNESOTA AND THE
NORTHERN EDGE OF A SHORTWAVE MOVING THROUGH SOUTHERN MINNESOTA AND
NORTHERN IOWA. THINK MOST OF THE PRECIPITATION WILL STAY OFF TO THE
WEST FOR TOMORROW.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 314 PM EDT FRI AUG 7 2015
FCST FOCUS IN THE MEDIUM RANGE PERIOD WL BE ON POPS THE SECOND HALF
OF THIS WEEKEND ASSOCIATED WITH STRONG DISTUBANCE OVER SCENTRAL
CANADA THAT WL BE DROPPING SLOWLY ESEWD THRU NW ONTARIO AND DRAGGING
A COLD FNT ACRS UPR MI ON SUN NGT. TEMPS AHEAD OF THE COLD FROPA WL
BE AOA NORMAL. DURING THE FIRST HALF OF THE NEXT WEEK...EXPECT TEMPS
TO FALL BLO NORMAL WITH NW FLOW ALOFT DEVELOPING BTWN A BLDG UPR RDG
IN THE PLAINS AND DEEPENING TROF DOWNSTREAM IN ERN NAMERICA. CNDN HI
PRES UNDER THIS NW FLOW ALOFT WL BRING GENERALLY DRY WX DURING THE
MON THRU WED PERIOD. LOOKS LIKE TEMPS WL REBOUND AOA NORMAL LATER IN
THE WEEK AS PLAINS RDG BLDS TOWARD THE WRN LKS.
SAT NGT THRU SUN NGT...STRONG SHRTWV OVER FAR NW ONTARIO THAT WL BE
TOPPING UPR RDG IN THE PLAINS IS FCST TO SLIDE SLOWLY ESE THRU NRN
ONTARIO. ALTHOUGH THERE ARE STILL SOME TIMING DIFFERENCES...MOST OF
THE LATEST GUIDANCE INDICATE A FASTER PRIMARY COLD FROPA ON SUN NGT.
SINCE THE SHARPER DYNAMIC FORCING ASSOCIATED WITH THE ONTARIO SHRTWV
WL REMAIN TO THE N OF UPR MI...POPS/PCPN AMOUNTS AS EARLY AS SAT NGT
IN ADVANCE OF THIS COLD FNT WL DEPEND ON THE DEGREE TO WHICH MSTR
INFLOW INTO THE UPR LKS WL BE DISRUPTED BY A W-E ORIENTED BNDRY
STRETCHING FM IOWA INTO THE LOWER LKS AND CONVECTION THAT FIRES
ALONG THIS AXIS ACCOMPANYING THE PASSAGE OF ANOTHER SHRTWV OVER THAT
AREA. THE 12Z NAM IS MOST EXTREME SHOWING A NEAR ABSENCE OF PCPN
ACRS THE CWA DURING THIS ENTIRE PERIOD WITH A LACK OF ANY MSTR
INFLOW/DYNAMIC FORCING TO THE N OF STRONG TS COMPLEX/DEEPER SFC LO
TRACKING ALONG THE BNDRY. THE OTHER MODELS SHOW A MORE PRONOUNCED
AXIS OF HIER H85 THETA E AND THUS MORE DEEP LYR MSTR CNVGC/FORCING/
QPF. BEST CHC FOR SOMWHAT HIER POPS WL BE OVER THE W ON SAT EVNG AND
THEN THE CENTRAL ON SUN AFTN/EVNG...WHEN THE 12Z GFS SHOWS MUCAPE AS
HI AS 2500 J/KG...DURING PERIODS OF DAYTIME HEATING. BUT GIVEN
MODEL/TIMING UNCERTAINTIES AND SUPPORT FOR LARGER SCALE FORCING TO
PASS TO THE N AND S OF THE CWA...FCST WL POPS WL BE NO HIER THAN THE
CHC CATEGORY.
MON...SINCE RECENT MEDIUM RANGE GUIDANCE HAS TRENDED TO SPEED UP
PASSAGE OF COLD FROPA ATTENDANT TO SHRTWV SHIFTING ESEWD THRU NW
ONTARIO AND ARRIVAL OF DEEP LYR QVECTOR DVGC/LARGER SCALE
SUBSIDENCE/MID LVL DRYING...PCPN CHCS FOR MON LOOK TO BE
DIMINISHING. WITH MORE SUNSHINE...H85 TEMPS FCST IN IN THE 10 TO 12C
RANGE WL SUPPORT MAX TEMPS IN THE 70S. LOCATIONS NEAR LK SUP WL BE
COOLEST WITH LLVL NNW FLOW IN ADVANCE OF APRCHG CNDN HI PRES.
MON NGT THRU WED...THE UPR RDG IN THE PLAINS IS FCST TO AMPLIFY
EARLY IN THE WEEK...ALLOWING THE TROF IN ERN NAMERICA TO DEEPEN AND
A MORE PRONOUNCED NW FLOW ALOFT BTWN THESE FEATURES TO PREVAIL OVER
THE GREAT LKS. THE ARRIVAL OF CNDN HI PRES/H85 TEMPS AS LO AS 8 TO
10C WL RESULT IN GENERALLY DRY AND COOLER WX FOR MON NGT INTO WED.
ALTHOUGH SOME OF THE MODELS INDICATE A SHRTWV EMBEDDED IN THE NW
FLOW ALOFT COULD CAUSE SOME SHOWERS DURING DAYTIME HEATING ON TUE...
THE COVERAGE/INTENSITY OF THESE SHOWERS WL BE LIMITED BY THE ABSENCE
OF ANY DEEPER MSTR AND GENERAL LARGER SCALE SUBSIDENCE UNDER THE
CONFLUENT NW FLOW ALOFT. RETAINED GOING DRY FCST FOR NOW. WITH
PLENTY OF SUNSHINE...WED AFTN WL TURN WARMER AS H85 TEMPS REBOUND
TOWARD 15C OVER THE W AS THE PLAINS RDG SHIFTS TOWARD THE WRN LKS.
LATE WEEK...A NUMBER OF THE EXTENDED MODELS SHOW ANOTHER SHRTWV
ROUNDING THE TOP OF THE PLAINS RDG WL INFLUENCE THE AREA ON THU AND
BRING THE THREAT OF SOME SHOWERS/TS. AS THE UPR RDG TO THE W BUILDS
BACK TOWARD THE UPR LKS IN THE WAKE OF THIS SHRTWV PASSAGE...FRI
SHOULD BE DRY AND WARMER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 147 PM EDT FRI AUG 7 2015
A LOW CENTERED IN WISCONSIN IS SHIFTING RAIN SHOWERS EAST ACROSS
WESTERN UPPER MICHIGAN AND EXPECT THAT TO CONTINUE THROUGH THE
AFTERNOON. THIS WILL USHER IN INCREASING LOW LEVEL MOISTURE AND THE
BIGGEST QUESTION IS THE TIMING OF THE LOW CLOUDS ARRIVING AT
KCMX/KSAW. WITH THE HEAVIEST PRECIPITATION DIVING FARTHER TO THE
SOUTH...WONDERING IF THE LOW LEVEL MOISTENING WILL TAKE A LITTLE
LONGER THAN INITIALLY EXPECTED AND HAVE DELAYED THE ARRIVAL
SLIGHTLY. ONCE THE LOW CLOUDS ARRIVE...WOULD EXPECT IFR OR LOWER
CONDITIONS TO PREVAIL FOR MUCH OF THE REST OF THE PERIOD. DID
CONTINUE THE LOWER VISIBILITIES DUE TO FOG...ESPECIALLY FOR KSAW
WHERE THE FAVORABLE UPSLOPE SOUTHEASTERLY FLOW WILL BE IN PLACE.
DRIER AIR SHOULD GRADUALLY MOVE INTO THE AREA DURING THE DAY ON
SATURDAY AND BRINGING INCREASING CEILINGS AND VISIBILITIES.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 254 PM EDT FRI AUG 7 2015
A LOW PRESSURE SYSTEM OVER WESTERN WISCONSIN WILL DISSIPATE TONIGHT
INTO SATURDAY MORNING AS IT MOVES EAST. MEANWHILE...A STRONGER LOW
NEAR LAKE WINNIPEG WILL MOVE TO JAMES BAY BY MONDAY..SWEEPING A
BROAD TROUGH ACROSS THE UPPER GREAT LAKES REGION. HIGH PRESSURE
WILL BUILD IN BEHIND THE TROUGH...AND CONTINUE INTO THE MIDDLE OF
NEXT WEEK. WITH WEAK PRESSURE GRADIENTS EXPECTED...WINDS ARE
EXPECTED TO STAY BELOW 20KTS THROUGH THE PERIOD. FINALLY...WITH
RAIN AND ABUNDANT LOW LEVEL MOISTURE MOVING OVER WESTERN AND
CENTRAL LAKE SUPERIOR...COULD SEE SOME PATCHY FOG OVER THOSE AREAS
TONIGHT INTO SATURDAY MORNING...BUT DON/T EXPECT WIDESPREAD...DENSE
FOG AT THIS TIME.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...KC
AVIATION...SRF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
254 PM EDT FRI AUG 7 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 254 PM EDT FRI AUG 7 2015
A SHORTWAVE HAS UNDERCUT THE UPPER RIDGE OVER THE UPPER MISSISSIPPI
VALLEY AND IS NOW DIVING SOUTHEAST ACROSS EASTERN WISCONSIN. THAT
WAVE IS SUPPORTING THE SHOWERS AND A FEW EMBEDDED THUNDERSTORMS
MOVING ACROSS THAT AREA. FARTHER TO THE WEST...A 1008MB SURFACE LOW
IS LOCATED NEAR EAU CLAIRE WISCONSIN. TO THE NORTHEAST OF THE
SURFACE LOW...AN AREA OF SHOWERS ARE MOVING EAST ACROSS UPPER
MICHIGAN AT THIS TIME...TIED TO THE NORTHERN EDGE OF THE 850-700MB Q-
VECTOR CONVERGENCE AND BROAD WARM AIR ADVECTION. THE HEAVIEST RAIN
SO FAR TODAY HAS FALLEN OVER THE WESTERN HALF OF THE U.P....WITH 0.5
TO 0.65 INCHES OF RAIN FALLING OVER THE BARAGA PLAINS TODAY. AMOUNTS
DIMINISH TO A TENTH OF AN INCH THROUGH 2PM FROM NEGAUNEE SOUTH TO
IRON MOUNTAIN AND EVEN LESS FARTHER TO THE EAST.
THE SURFACE LOW AND SHORTWAVE WILL SLOWLY DISSIPATE AS THEY MOVE TO
THE EAST-SOUTHEAST TONIGHT...LIMITING THE INFLUENCE OF BOTH FEATURES
THROUGH THE NIGHT. EXPECT THE SHOWERS TO DIMINISH AND DRIFT TO THE
SOUTHEAST THROUGH THE EVENING (TIED TO THE 850-700MB Q-VECTOR
CONVERGENCE)...AND LARGELY BE OUT OF THE CWA AROUND 06Z. BUT WITH
THE MODELS CONTINUING TO SHOW LOW LEVEL MOISTURE PIVOTING TO THE
NORTHWEST ON THE NORTHEAST SIDE OF THE 925-850 TROUGH IN
CENTRAL/NORTHERN WISCONSIN...EXPECT ABUNDANT LOW CLOUDS TO BE IN
PLACE ACROSS THE AREA. THESE LOW CLOUDS CAN ALREADY BE SEEN OVER
EASTERN MINNESOTA AND WESTERN WISCONSIN...AND THEY HAVE BEEN WORKING
INTO WESTERN UPPER MICHIGAN THROUGH THE DAY. THINK DRYING AND
INCREASING SUBSIDENCE ABOVE THAT...GENERALLY ABOVE 750MB OVER THE
WEST...WILL ALSO HELP THE DIMINISHMENT OF THE WIDESPREAD SHOWERS.
DID HOLD ONTO THE SHOWERS A LITTLE LONGER OVER THE HIGHER TERRAIN
UPSLOPE AREAS IN CENTRAL UPPER MICHIGAN DUE TO THE FAVORABLY
SOUTHEASTERLY FLOW...BUT THE PRECIPITATION MAY FALL MORE AS DRIZZLE
THAN RAIN. IN ADDITION...HAVE TRENDED FOG UP TO AREAS TO WIDESPREAD
VALUES OVER THE WEST/CENTRAL U.P. WHERE THE BETTER RAIN HAS FALLEN
AND TIED TO THE LOWEST 5KFT BEING SATURATED ON THE NAM/GFS
SOUNDINGS. ONE ITEM TO WATCH...THE LATEST RAP RUNS HAVE BEEN HOLDING
ONTO DRIER NEAR SURFACE AIR OVER THE NORTH CENTRAL...WHICH WOULD
GREATLY REDUCE THE POTENTIAL FOR LOW CLOUDS AND FOG.
EXPECT THE LOW LEVEL MOISTURE TO HOLD ON THROUGH THE FIRST HALF OF
SATURDAY OVER THE WESTERN HALF TO TWO-THIRDS OF THE U.P. BEFORE THE
CONTINUED SUBSIDENCE AND INFLUX OF DRIER AIR TRIES TO BREAK OF THE
CLOUDS. WHILE THAT SHOULD RAISE THE CEILINGS ACROSS THE AREA...STILL
EXPECT THE WESTERN CWA TO REMAIN MOSTLY CLOUDY...WHILE THE EASTERN
THIRD OF THE U.P. WILL EXPERIENCE LINGERING MID CLOUDS IN THE
MORNING...TRANSITIONING TO DIURNAL CU IN THE AFTERNOON.
CONTINUED TO SHOW SLIGHT CHANCE POPS MOVING INTO WESTERN LAKE
SUPERIOR AND FAR WESTERN UPPER MICHIGAN TOMORROW AFTERNOON...AHEAD
OF THE SURFACE TROUGH MOVING INTO NORTHERN MINNESOTA AND THE
NORTHERN EDGE OF A SHORTWAVE MOVING THROUGH SOUTHERN MINNESOTA AND
NORTHERN IOWA. THINK MOST OF THE PRECIPITATION WILL STAY OFF TO THE
WEST FOR TOMORROW.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 504 AM EDT FRI AUG 7 2015
DURING THE LONG TERM...ZONALLY ORIENTED FLOW WILL PREVAIL THRU THE
UPPER GREAT LAKES INITIALLY...JUST S OF A TROF/RIDGE/TROF PATTERN
ACROSS SRN CANADA. UNDER THIS FLOW...MID LEVEL LOW CURRENTLY OVER
SRN SASKATCHEWAN IS FCST TO SLOWLY MOVE E INTO NRN ONTARIO BY SUN
MORNING. IN ITS WAKE...A FAIRLY AMPLIFIED RIDGE WILL DEVELOP TO THE
LEE OF THE ROCKIES EARLY NEXT WEEK AND THEN DRIFT SLIGHTLY E TO
CNTRL NAMERICA MIDWEEK. THIS WILL FORCE INCREASED TROFFING INTO ERN
NAMERICA DURING THE FIRST HALF OF NEXT WEEK...RESULTING IN
PRONOUNCED NNW FLOW DEVELOPING INTO THE UPPER GREAT LAKES. THESE
CHANGES WILL LEAD TO OPPORTUNITIES FOR PCPN OVER THE NEXT FEW DAYS
UNTIL NNW FLOW SHARPENS EARLY NEXT WEEK. HOPEFULLY...AREAS THAT NEED
A GOOD SOAKING RAIN WILL RECEIVE MUCH NEEDED RAINFALL IN THE NEXT
FEW DAYS. THE SHARP NNW FLOW DEVELOPING EARLY NEXT WEEK WITH SFC
HIGH PRES PREVAILING WILL BRING A RETURN TO DRY WEATHER.
HOWEVER...TYPICAL FOR SUMMERTIME NW FLOW...ANY SUBTLE SHORTWAVE
DROPPING THRU THE AREA COULD SPARK ISOLD AFTN CONVECTION. AS FOR
TEMPS...READINGS WON`T BE TOO FAR FROM NORMAL THRU THE WEEKEND (ON
THE WARM SIDE OF NORMAL FOR MOST LOCATIONS). NW FLOW DEVELOPING
EARLY NEXT WEEK WILL DROP TEMPS TO BLO NORMAL...BUT NOT
SIGNIFICANTLY AS THERE WON`T BE A TAP OF CHILLY AIR FROM NORTHERN
CANADA.
BEGINNING SAT...COMPLEX OF SHORTWAVE ENERGY RESPONSIBLE FOR SHRA
TODAY/TONIGHT WILL BE SHIFTING E OF THE AREA BY MORNING. AFTER ANY
LINGERING SHRA END...WEAK HEIGHT RISES/DEEP LAYER QVECTOR DIVERGENCE
SUGGEST DRY WEATHER WILL FOLLOW. MID LEVEL LOW CURRENTLY OVER SRN
SASKATCHEWAN WILL REACH THE MANITOBA/ONTARIO BORDER BY 00Z SUN.
WHILE ASSOCIATED COLD FRONT WILL STILL BE WELL W OF HERE IN NW MN
LATE IN THE AFTN...A NUMBER OF MODELS GENERATE SOME PCPN FARTHER E
INTO WRN UPPER MI WHERE MLCAPES INCREASE UPWARDS OF 500J/KG OR SO IN
THE PRESENCE OF THE ARRIVAL OF WEAK DEEP LAYER QVECTOR CONVERGENCE.
WILL KEEP FLAVOR OF INHERITED FCST AND MAINTAIN SCHC POPS IN THE
LATE AFTN OVER THE W.
SAT NIGHT THRU SUN NIGHT...MID LEVEL LOW DRIFTS ACROSS NRN ONTARIO.
TO THE S OF THIS FEATURE...MODELS INDICATE A TRAIN OF WEAK SHORTWAVE
ENERGY TRACKING E FROM THE NRN ROCKIES TO THE UPPER GREAT LAKES.
LACK OF A COHERENT FEATURE MAKES FOR LOW CONFIDENCE IN FORECASTING
COVERAGE OF SHRA/TSTMS AND TIMING OF BEST CHANCE OF PCPN. GIVEN THE
INHERENT UNCERTAINTY IN HOW CONVECTION WILL DEVELOP WITH THE STREAM
OF WEAK SHORTWAVE ENERGY...PLAN TO UTILIZE A CONSENSUS OF CURRENT
AND RECENT MODEL RUNS TO CONSTRUCT POPS. ALSO...IT APPEARS AT THIS
POINT THAT THERE PROBABLY WON`T BE SUFFICIENT INSTABILITY DEVELOPING
TO SUPPORT AN ORGANIZED SVR TSTM RISK...ESPECIALLY WITH DEEP LAYER
SHEAR UNDER 30KT THRU THE PERIOD. LATEST SPC OUTLOOKS CONCUR WITH
ONLY A GENERAL THUNDER OUTLOOK FOR UPPER MI.
BY THE TIME MON ROLLS AROUND...AFOREMENTIONED NNW FLOW WILL BE
LOCKING IN WITH COLD FRONT LIKELY E OF THE FCST AREA BY 12Z...
LEADING TO A DRYING TREND. DRY WEATHER SHOULD THEN BE THE RULE
TUE/WED AS SFC HIGH PRES ASSOCIATED WITH SHARP UPSTREAM RIDGE
ARRIVES. HOWEVER...ANY SUBTLE SHORTWAVE DROPPING THRU THE AREA COULD
SPARK ISOLD AFTN CONVECTION...ESPECIALLY TUE...BEFORE SFC HIGH PRES
SETTLES INTO THE AREA. RIGHT NOW...POTENTIAL IS NOT GREAT ENOUGH TO
INCLUDE AN EXPLICIT MENTION OF PCPN.
HEADING INTO THU...FCST WILL DEPEND ON WHETHER THE UPSTREAM RIDGE IS
PROGRESSIVE...BEGINS TO BREAK DOWN OR WHETHER ANY SHORTWAVES RIDE
AROUND THE RIDGE AND DROP TOWARD THE AREA. RECENT MEDIUM RANGE MODEL
RUNS HINT THAT THE RIDGE AXIS WILL REMAIN TO THE W AND SHORTWAVE
ENERGY WILL ROUND IT...PERHAPS BRINGING SHRA/TSRA CHC LATE IN THE
DAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 147 PM EDT FRI AUG 7 2015
A LOW CENTERED IN WISCONSIN IS SHIFTING RAIN SHOWERS EAST ACROSS
WESTERN UPPER MICHIGAN AND EXPECT THAT TO CONTINUE THROUGH THE
AFTERNOON. THIS WILL USHER IN INCREASING LOW LEVEL MOISTURE AND THE
BIGGEST QUESTION IS THE TIMING OF THE LOW CLOUDS ARRIVING AT
KCMX/KSAW. WITH THE HEAVIEST PRECIPITATION DIVING FARTHER TO THE
SOUTH...WONDERING IF THE LOW LEVEL MOISTENING WILL TAKE A LITTLE
LONGER THAN INITIALLY EXPECTED AND HAVE DELAYED THE ARRIVAL
SLIGHTLY. ONCE THE LOW CLOUDS ARRIVE...WOULD EXPECT IFR OR LOWER
CONDITIONS TO PREVAIL FOR MUCH OF THE REST OF THE PERIOD. DID
CONTINUE THE LOWER VISIBILITIES DUE TO FOG...ESPECIALLY FOR KSAW
WHERE THE FAVORABLE UPSLOPE SOUTHEASTERLY FLOW WILL BE IN PLACE.
DRIER AIR SHOULD GRADUALLY MOVE INTO THE AREA DURING THE DAY ON
SATURDAY AND BRINGING INCREASING CEILINGS AND VISIBILITIES.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 254 PM EDT FRI AUG 7 2015
A LOW PRESSURE SYSTEM OVER WESTERN WISCONSIN WILL DISSIPATE TONIGHT
INTO SATURDAY MORNING AS IT MOVES EAST. MEANWHILE...A STRONGER LOW
NEAR LAKE WINNIPEG WILL MOVE TO JAMES BAY BY MONDAY..SWEEPING A
BROAD TROUGH ACROSS THE UPPER GREAT LAKES REGION. HIGH PRESSURE
WILL BUILD IN BEHIND THE TROUGH...AND CONTINUE INTO THE MIDDLE OF
NEXT WEEK. WITH WEAK PRESSURE GRADIENTS EXPECTED...WINDS ARE
EXPECTED TO STAY BELOW 20KTS THROUGH THE PERIOD. FINALLY...WITH
RAIN AND ABUNDANT LOW LEVEL MOISTURE MOVING OVER WESTERN AND
CENTRAL LAKE SUPERIOR...COULD SEE SOME PATCHY FOG OVER THOSE AREAS
TONIGHT INTO SATURDAY MORNING...BUT DON/T EXPECT WIDESPREAD...DENSE
FOG AT THIS TIME.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...ROLFSON
AVIATION...SRF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
247 PM EDT FRI AUG 7 2015
.SHORT TERM...TONIGHT
ORGANIZING DEFORMATION ASSOCIATED WITH THE LOW AMPLITUDE WAVE
APPROACHING THE WESTERN SHORES OF LAKE MICHIGAN AT PRESS TIME IS
SUPPORTING AN ORGANIZING RAIN SHIELD OVER EASTERN WISCONSIN. MODEL
PROGS REMAIN INSISTENT THAT THIS WAVE WILL BECOME INCREASINGLY
SHEARED THIS EVENING, THE EARLY SIGNS OF WHICH ARE ALREADY BECOMING
EVIDENT ON CURRENT WV IMAGERY. CEILINGS WITHIN THE ACTIVE AREA OF
PRECIP ARE GENERALLY ABOVE 7KFT, A TESTAMENT TO THE AMOUNT OF DRY
AIR IN THE COLUMN. PER 12Z DTX SOUNDING AND LATEST RAP PROGS, EVEN
DRIER AIR RESIDES OVER SOUTHEAST MICHIGAN. TAKEN IN CONSIDERATION
WITH RAPIDLY WEAKENING FORCING OVER THE NEXT SEVERAL HOURS, THIS
CASTS DOUBT ON THE ABILITY OF PRECIP TO SURVIVE ITS TREK INTO
SOUTHEAST MICHIGAN. SOME SEMBLENCE OF THE MID-LEVEL CIRCULATION MAY
PROVIDE JUST ENOUGH ASCENT/DEFORMATION TO RESULT IN A PERIOD OF
LIGHT RAIN FALLING OUT OF HIGH CLOUDS OVER THE SAGINAW VALLEY WHERE
A HIGH CHC POP IS IN PLACE. ELSEWHERE...JUST A CHC LATE TONIGHT
NORTH OF I-69 WITH NO WX MENTION ELSEWHERE. GUIDANCE LOOKS ON TRACK
WITH LOWS IN THE LOW TO MID 60S...A FEW DEGREES WARMER THAN LAST
NIGHT OWING TO INCREASED CLOUD COVER.
&&
.LONG TERM...SATURDAY THROUGH THURSDAY
DAMPENING MID LEVEL WAVE AND ATTENDANT 100 KNOT UPPER JET CORE IN
THE PROCESS OF PIVOTING THROUGH LOWER MICHIGAN EARLY SATURDAY. MOST
FAVORABLE UPPER LEVEL FORCING TIED TO THESE FEATURES WILL TEND TO
ALIGN FROM THE TRI-CITIES/THUMB INTO NORTHERN LOWER MICHIGAN THROUGH
THIS TIME. THIS WILL MAINTAIN A WINDOW FOR LIGHT SHOWER PRODUCTION
ACROSS THIS CORRIDOR DURING THE MORNING PERIOD...PERPETUATION OF A
STABLE EASTERLY FLOW SUGGESTING MINIMAL POTENTIAL FOR THUNDERSTORMS.
HI RES MODEL GUIDANCE DOES HINT THAT SOME FORM OF TRAILING PV
FILAMENT AND/OR WEAK SURFACE TROUGH MAY THEN SHIFT ACROSS SE
MICHIGAN DURING PEAK HEATING. THIS IN THE PRESENCE OF SOME LEFT
EXIT REGION JET DYNAMICS MAY PROVE SUFFICIENT IN GENERATING A LOW
END COVERAGE OF SHOWERS /EMBEDDED THUNDER/ DURING THE MID-LATE
AFTERNOON. THE OVERALL SETUP REMAINS SOMEWHAT NEBULOUS AT THIS
STAGE WITH MOISTURE QUALITY AND DEGREE OF DESTABILIZATION AN
ISSUE...AND WILL SIMPLY PROVIDE A SLIGHT CHANCE MENTION. LITTLE
VARIATION IN THE TEMPERATURE PATTERN...WITH AT LEAST PARTIAL SUN
STILL SUPPORTING AFTERNOON HIGHS IN THE VICINITY OF 80 DEGREES.
ATTENTION HEADING INTO THE LATTER HALF OF THE WEEKEND TURNS TO
ANOTHER LOW AMPLITUDE SHORTWAVE EJECTING OVER THE MEAN SOUTHERN
PLAINS RIDGE. HIGH DEGREE OF VARIABILITY YET WITHIN THE MODEL
SOLUTION SPACE IN TERMS OF POTENTIAL STRENGTH...TIMING AND
POSITIONING OF THE ASSOCIATED LOW-MID LEVEL RESPONSE AS THIS SYSTEM
LIFTS EAST OF THE MISSISSIPPI. 12Z NAM TRENDING TOWARD A MUCH MORE
DYNAMIC SOLUTION...NETTING A MORE PRONOUNCED AND PROGRESSIVE
DOWNSTREAM EXPANSION OF LARGE SCALE ASCENT AND MOISTURE TRANSPORT
NORTH OF THE ATTENDANT WARM FRONTAL BOUNDARY AND INTO LOWER MICHIGAN
BY LATE SUNDAY. THIS SOLUTION SUGGESTS AN INCREASING POTENTIAL FOR
SHOWERS AND ELEVATED THUNDERSTORMS SUNDAY AFTERNOON AND EVENING.
HOWEVER 4 KM NAM AND CONSENSUS OF REMAINING GUIDANCE POINTS TOWARD A
MORE TEMPERED/SLOWER EVOLUTION...A GREATER WINDOW FOR PRECIPITATION
DEVELOPMENT HOLDING OFF UNTIL SUNDAY NIGHT/EARLY MONDAY. EVENTUAL
OUTCOME LIKELY CARRIES STRONG DEPENDENCE ON HOW CONVECTIVE TRENDS
EVOLVE UPSTREAM AND SPILL EASTWARD...SE MICHIGAN STILL SEEMINGLY
POSITIONED OUTSIDE OF THE GREATER INSTABILITY AXIS THROUGH THIS
PERIOD. FOR NOW...WILL HOLD TIGHT WITH A DRY FORECAST ON
SUNDAY...CENTERING POPS FOR SUNDAY NIGHT AND MONDAY. ASSUMING AN
EARLIER ONSET OF THICKER CLOUDINESS AND/OR PRECIPITATION NEVER
MATERIALIZES THROUGH PEAK HEATING...PERSISTENCE WILL LEAVE HIGHS
AGAIN WITHIN A COUPLE DEGREE OF 80F.
ZONAL FLOW ACROSS THE CORN BELT MONDAY EXPECTED TO AMPLIFY INTO A
TROUGH AS 80+ KT H25 JET STREAK DEVELOPS. WEAK CYCLOGENESIS ALONG
WITH SOME FORCING FROM FAVORABLE POSITIONING OF POLEWARD JET EXIT
REGION OVER THE LOWER GREAT LAKES ARGUES FOR AT LEAST CHANCE POPS
MONDAY. INSTABILITY LOOKS LIMITED WITH LI ONLY DROPPING TO AROUND
-2...SO HAVE CHC SHOWERS AND SLIGHT CHC T-STORMS. SURFACE CYCLONE
PROGGED TO INTENSIFY OVER THE NORTHEASTERN US WHICH FAVORS MORE
AGRESSIVE COLD/DRY AIR ADVECTION TUESDAY. UPPER TROUGH AMPLIFIES
OVER THE NORTHEASTERN US MIDWEEK WITH LOWER MI IN THE SUBSIDENCE
REGION UPSTREAM OF THE TROUGH. UPSHOT IS MAINLY DRY/COOL FORECAST
MIDWEEK.
&&
.MARINE...
MODEST NORTHEAST WINDS THROUGH THE EVENING WILL MAINTAIN SOME
ENHANCED WAVE DEVELOPMENT OVER THE NEARSHORE WATERS. GENERALLY
WEAKER EAST TO SOUTHEAST WINDS WILL THEN HOLD THROUGH THE WEEKEND AS
THE HIGH PRESSURE CENTER REMAINS POSITIONED JUST NORTHEAST OF THE
REGION.
&&
.AVIATION...ISSUED 110 PM EDT FRI AUG 7 2015
VFR THROUGH THE PERIOD WITH HIGH BASED CU THIS AFTN DISSIPATING WITH
THE LOSS OF HEATING THIS EVENING. LIGHT EAST WINDS WILL SUPPORT VERY
DRY RESIDENT COLUMN AND MAINTENANCE OF HIGH CEILINGS AS A WEAK UPPER
WAVE PASSES TONIGHT. A BRIEF PERIOD OF HIGH BASED RAIN SHOWERS WILL
BE POSSIBLE AT KMBS AND PERHAPS FNT LATE.
FOR DTW...SCATTERED TO BROKEN COVERAGE OF DIURNAL CU AT 4-5KFT
EXPECTED THIS AFTN BASED ON LATEST SATELLITE TRENDS AND OBS.
CU WILL DISSIPATE WITH THE ONSET OF NOCTURNAL STABILIZATION.
//DTW THRESHOLD PROBABILITIES...
* LOW FOR CIG AOB 5KFT
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
SHORT TERM...JVC
LONG TERM....MR/DT
MARINE.......MR
AVIATION.....JVC
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
110 PM EDT FRI AUG 7 2015
.AVIATION...
VFR THROUGH THE PERIOD WITH HIGH BASED CU THIS AFTN DISSIPATING WITH
THE LOSS OF HEATING THIS EVENING. LIGHT EAST WINDS WILL SUPPORT VERY
DRY RESIDENT COLUMN AND MAINTENANCE OF HIGH CEILINGS AS A WEAK UPPER
WAVE PASSES TONIGHT. A BRIEF PERIOD OF HIGH BASED RAIN SHOWERS WILL
BE POSSIBLE AT KMBS AND PERHAPS FNT LATE.
FOR DTW...SCATTERED TO BROKEN COVERAGE OF DIURNAL CU AT 4-5KFT
EXPECTED THIS AFTN BASED ON LATEST SATELLITE TRENDS AND OBS.
CU WILL DISSIPATE WITH THE ONSET OF NOCTURNAL STABILIZATION.
//DTW THRESHOLD PROBABILITIES...
* LOW FOR CIG AOB 5KFT
&&
.PREV DISCUSSION...ISSUED 846 AM EDT FRI AUG 7 2015
UPDATE...
QUICK UPDATE TO REMOVE CLOUD COVER FOR THIS MORNING BASED ON
SATELLITE TRENDS OVER THE LAST COUPLE OF HOURS AND PULL SCHC POPS
FOR THIS AFTERNOON ACROSS THE WEST AS WAA LOOKS TOO WEAK TO OVERCOME
THE DEEP LAYER OF VERY DRY AIR EVIDENT ON 12Z DTX SOUNDING. MID-
CLOUD AND DIURNAL CU WILL INCREASE BY LATE MORNING/EARLY AFTN
SUPPORTING CURRENT FORECAST HIGHS IN THE MID 70S TO AROUND 80, RIGHT
ABOUT NORMAL FOR EARLY AUGUST. UPDATE TO THE GRIDS AND ZFP
FORTHCOMING.
PREV DISCUSSION...ISSUED 254 AM EDT FRI AUG 7 2015
SHORT TERM...TODAY AND TONIGHT
UPPER SHORTWAVE OVER THE UPPER MIDWEST WILL TRACK ACROSS MICHIGAN
LATE TODAY AND TONIGHT AS IT RIDES ALONG THE NORTHERN PERIPHERY OF
AN UPPER RIDGE CENTERED OVER THE SOUTHERN PLAINS. THIS SHORTWAVE HAS
BEEN LOOKING MORE IMPRESSIVE ON WATER VAPOR AS THE NIGHT
PROGRESSES...AND HAS BEEN KICKING OFF A PRETTY GOOD COVERAGE OF
SHOWERS AND THUNDERSTORMS OVER MINNESOTA AND WISCONSIN. 00Z NAM/GFS
ONLY CREDIT THIS WAVE WITH A MODEST PUSH OF MID-LEVEL THETA-E
ADVECTION LATE TODAY/TONIGHT...AND LITTLE TO NO QPF OUTPUT OVER THE
AREA. ACTUALLY PREFER THE MORE AGRESSIVE SOLUTIONS SUCH AS THE
12Z/00Z EURO AND THE HRRR (EVEN THOUGH IT DOESN`T GO OUT QUITE FAR
ENOUGH YET) GIVEN APPEARANCE ON WATER VAPOR. INHERITED FORECAST WAS
ALREADY ON THE AGGRESSIVE SIDE AND CHANGES TO THE FORECAST WERE
MAINLY TO ADJUST TIMING AND INCREASE POPS SLIGHTLY OVER THE SAGINAW
VALLEY. SHOWERS AND PERHAPS A THUNDERSTORM COULD ARRIVE INTO THE
WESTERN PORTION OF THE FORECAST AREA AS EARLY AS 20Z/4PM. BEST
POTENTIAL STILL LOOKS BETWEEN BETWEEN 8PM AND 2AM...AHEAD OF THE
UPPER WAVE AS IT TRACKS INTO MICHIGAN. HIGHEST POPS OVERALL REMAIN
OVER THE SAGINAW VALLEY (MID-RANGE CHANCE)...AND THEN TAPER TO JUST
A SLIGHT CHANCE TOWARDS THE DETROIT AND ANN ARBOR AREAS. ALTHOUGH IT
IS ONLY 12-24 HOUR OUT...MODELS ARE STILL STRUGGLING A LITTLE WITH
TRACK AND TIMING OF THIS SMALL FEATURE. THIS LEADS TO LOWER
CONFIDENCE REGARDING COVERAGE AND TIMING OVERALL.
WITH PLENTY OF HIGH CLOUDS STREAMING IN AHEAD OF THIS UPPER WAVE FOR
THE EARLY PART OF THE DAY...AND A LIGHT EAST FLOW OFF THE
LAKES...EXPECT MAX TEMPERATURES TO CONTINUE RUNNING SLIGHTLY BELOW
NORMAL IN THE MID 70S TO NEAR 80. CLOUD COVER WILL THEN KEEP MIN
TEMPS MILD TONIGHT IN THE UPPER 50S TO LOW 60S.
LONG TERM...
ASIDE FROM A FEW LINGERING SHOWERS OVER THE NORTHERN FORECAST AREA
SATURDAY MORNING...EXPECT A BULK OF THE WEEKEND TO REMAIN DRY AS A
RIDGE OF SURFACE HIGH PRESSURE PERSISTS FROM EASTERN ONTARIO BACK
INTO LAKE HURON AND SOUTHEAST MICHIGAN. A SUBTLE SHORTWAVE RIDGE
WILL ALSO BUILD THROUGH THE AREA AS A FILLING UPPER LOW PRESSURE
SYSTEM LUMBERS EAST ACROSS SOUTHERN CANADA. THIS WILL PROVIDE A
SLIGHTLY WARMER AIRMASS AND ALLOW MAXIMUM TEMPERATURES TO CLIMB INTO
THE LOWER 80S IN MANY AREAS BOTH SATURDAY AND SUNDAY AFTERNOON.
AS THE AFOREMENTIONED RIDGE SHIFTS EAST OF THE AREA EARLY NEXT WEEK
AND MEAN TROUGH AXIS ASSOCIATED WITH WHAT STILL EXISTS OF SOUTHERN
CANADA UPPER LOW ENCROACHES ON THE CENTRAL GREAT LAKES...EXPECT RAIN
CHANCES TO INCREASE FROM SUNDAY EVENING/NIGHT INTO MONDAY. THIS WILL
BE FURTHER ENHANCED AS ADDITIONAL SHORTWAVE ENERGY CURRENTLY OFF THE
CALIFORNIA COAST GRADUALLY WORKS NORTHEAST INTO THE NORTHERN ROCKIES
AND PLAIN STATES AND IS EVENTUALLY FUNNELED INTO THE GREAT LAKES
AROUND THE SOUTHERN PERIPHERY OF LEAD SYSTEM IN CANADA.
ONCE EAST OF THE AREA BY MID NEXT WEEK...THIS SYSTEM WILL AMPLIFY
OVER EASTERN CANADA AND LEAD TO A RATHER NOTABLE UPPER TROUGH FROM
THE CENTRAL/EASTERN GREAT LAKES INTO EASTERN CANADA/NORTHEAST CONUS.
EXPECT DRIER WEATHER WITHIN NORTH/NORTHWEST FLOW ON THE BACK SIDE OF
THIS DEVELOPING TROUGH. THIS EVOLVING PATTERN WILL ALSO LEAD TO
COOLER READINGS ONCE AGAIN WITH MID 70S COMMON FOR AFTERNOON HIGH
TEMPERATURES MID/LATE NEXT WEEK.
MARINE...
HIGH PRESSURE CENTERED OVER LAKE HURON WILL SUSTAIN A LIGHT WIND
INTO TODAY...WITH JUST A MODEST INCREASE IN NORTHEAST WIND LATE IN
THE DAY LEADING TO SOME ENHANCED WAVE DEVELOPMENT OVER THE NEARSHORE
WATERS BY THIS EVENING. GENERALLY WEAKER EAST TO SOUTHEAST WINDS
WILL THEN HOLD THROUGH THE WEEKEND AS THE HIGH PRESSURE CENTER
REMAINS POSITIONED JUST NORTHEAST OF THE REGION.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....JVC
UPDATE.......JVC
SHORT TERM...HLO
LONG TERM....DG
MARINE.......DG
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
1157 AM CDT FRI AUG 7 2015
...18z Aviation Forecast Update...
.SHORT TERM...(Today and Tonight)
Issued at 0322 AM CDT FRI AUG 07 2015
Convection has developed over southwestern Missouri fueled by a
shortwave aloft and modest low level jet/moisture transport. HRRR
and RAP has good handle on this and pushes it southeast into south
central Missouri shortly after 12Z and should weaken and dissipate
through midday. After that, upper level high over the southern
plains and southwest conus will expand northeast towards the
Ozarks later today and tonight. This will be the beginning of
warming temperatures. Expect mainly sunny skies by this afternoon
which will aid in the rise. Expect warmest readings across
southeast Kansas into southwest Missouri where highs will be in
the lower to middle 90s, and just middle 80s over the eastern
Ozarks. Heat index values will flirt with advisory criteria for a
few hours this afternoon over southeast Kansas and southwest
Missouri, but will hold off on any headlines. A warm and humid
night is in store tonight with lows in the lower to middle 70s.
.LONG TERM...(Saturday through Thursday)
Issued at 0322 AM CDT FRI AUG 07 2015
Main forecast concern in this time frame is heat and heat index
values for both Saturday and Sunday and the need for any heat
related headlines. Upper ridge firmly in place across the Ozarks
both days. The hottest days looks to be Sunday with heat index
values in the 105 to 110 degree range. will likely need advisories
area-wide Sunday and perhaps only the western half of the forecast
area Saturday.
Medium range models continue to advertise a shortwave breaking down
the northern extent of the ridge Sunday night and Monday allowing
for a frontal boundary to make into the area. This will bring rain
chances back into the forecast, with the better chances across
central Missouri. It will also help cool temperatures off. This
wave should be east of the area later Monday with northwest flow
and surface high pressure nudging into the area for Tuesday
through Thursday, for cooler and quieter weather.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday Afternoon)
Issued at 1155 AM CDT FRI AUG 07 2015
Pilots flying in and out of the local area can expect VFR
conditions. Winds will be light and variable becoming light
south-southeast tonight. There may be some light ground fog or
mist in the morning. Have a TEMPO group from 10z to 13z for MVFR
vis or 5sm for this potential.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
SHORT TERM...Raberding
LONG TERM...Raberding
AVIATION...Griffin
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
315 PM CDT FRI AUG 7 2015
.SHORT TERM...(TONIGHT THROUGH MONDAY)
ISSUED AT 315 PM CDT FRI AUG 7 2015
THE PRIMARY FORECAST CONCERNS ARE IN REGARDS TO THE POTENTIAL FOR
TSTMS/RAIN LATER TONIGHT AND INTO SATURDAY...PLUS THE CHANCE OF
SEVERE WEATHER SATURDAY.
MAIN FEATURES FROM THE UPPER AIR MAPS THIS MORNING INCLUDED THE
FOLLOWING. AT 300 MB A 75 KT JET STREAK WAS OVER SRN CA PUNCHING TO
THE E/NE. THE 500 MB PATTERN IN GENERAL SHOWED TROUGHING ACROSS THE
W AND E COASTS AND A RIDGE CENTERED OVER TX/OK. CLOSED LOWS WERE
NOTED OVER SRN ALTA AND OVER CNTRL CA. 12 HOUR HEIGHT FALLS WERE
AROUND 50 METERS WITH THE CA SYSTEM...WHICH CONTINUED TO LIFT INTO
NV ACCORDING TO RECENT WATER VAPOR IMAGERY AND RECENT RUC MODEL
INITIALIZATIONS. A THERMAL RIDGE AT 700 MB EXTENDED FROM THE TX
PNHDL UP INTO CO. FAIRLY DECENT MOISTURE WAS NOTED AT 700 MB FROM
AZ INTO SRN NV WITH DEWPOINTS 5-8 DEGREES C. THE KOAX SOUNDING
THIS MORNING HAD ABOUT 0.94 INCHES OF PRECIPITABLE WATER (PW). THIS
WILL BE INCREASING OVER THE AREA TONIGHT. 12Z GFS SHOWED VALUES
APPROACHING 2 INCHES FOR MOST OF OUR AREA BY 12Z SAT AND NEAR 2.25
INCHES BY 00Z SUN. THE 12Z NAM WAS A BIT HIGHER AND MIGHT HAVE
BEEN A BIT OVERDONE.
PREVIOUS FORECAST TREND WAS FOR INCREASING POPS OVERNIGHT AND THAT
STILL SEEMS ON TRACK. WILL KEEP HIGHEST POPS PRIOR TO 12Z SAT OVER
ERN NE...SHIFTING HIGHEST NUMBERS TO NERN NE BY LATE MORNING. MID
LEVEL TEMPS ARE EXPECTED TO WARM SAT MORNING OVER THE SRN HALF OF
THE FCST AREA...SO SHIFTED HIGHEST POPS TO OUR WRN IA ZONES FOR THE
LATE AFTN AND EVENING. CONVECTIVE EVOLUTION AFTER THE MORNING STORMS
IS UNCERTAIN...BUT SHEAR PARAMETERS COULD BE FAVORABLE FOR SOME
SUPERCELLS IN THE AFTN AND EVENING. BEST SHOT FOR HEAVY RAIN WILL
BE ACROSS IOWA SATURDAY NIGHT.
STORM CHANCES SHOULD DIMINISH AFTER MIDNIGHT SATURDAY NIGHT...AND
SUNDAY RAIN CHANCES LOOK FAIRLY LOW. MID LEVEL RIDGE AXIS WILL START
TO BUILD FROM TX UP INTO SASK MONDAY WITH DECENT TROUGHING OVER THE
GREAT LAKES REGION.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 315 PM CDT FRI AUG 7 2015
A STRONG MID TROPOSPHERIC RIDGE WILL BE BUILDING AT THE START OF
THIS PERIOD OVER MID AMERICA. BY LATE WEEK...THE CENTER OF THE
ANTICYCLONE THAT STARTED OUT OVER TX/OK SHOULD RETROGRADE BACK
INTO NM AND CO. THIS PATTERN GENERALLY PRODUCES WARMER THAN NORMAL
TEMPERATURES (ESPECIALLY HIGHS) AND BELOW NORMAL PCPN. SO...BUMPED
UP HIGHS A BIT COMPARED TO A GFS/ECMWF BLEND.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 119 PM CDT FRI AUG 7 2015
VFR CONDITIONS ARE EXPECTED THROUGH THE AFTERNOON AND INTO
TONIGHT. A STORM SYSTEM MOVING INTO THE HIGH PLAINS WILL SPREAD
SHRA/TSRA EWD OVERNIGHT AND THIS ACTIVITY WILL LIKELY IMPACT ALL 3
TAF SITES /ESPECIALLY KOMA-KOFK/ LATE TONIGHT AND INTO SAT MRNG.
WILL INCLUDE PREVAILING CONDITIONS AT KOFK...AND TEMPO GROUPS AT
KOMA/KLNK. MVFR VSBY IS POSSIBLE IN THIS ACTIVITY. LIGHT WINDS
THIS AFTERNOON SHOULD BECOME SOUTHEAST THIS EVENING...BUT WILL
LIKELY BE VARIABLE AROUND RA LATE TONIGHT AND INTO SAT MRNG.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...MILLER
LONG TERM...MILLER
AVIATION...BOUSTEAD
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
1018 AM PDT FRI AUG 7 2015
.SYNOPSIS...MONSOON MOISTURE IN PLACE ACROSS THE REGION WILL BRING
CONTINUED CHANCES FOR SHOWERS AND THUNDERSTORMS TODAY. THUNDERSTORM
ACTIVITY WILL DECREASE FROM WEST TO EAST TODAY AS DRIER AIR PUSHES
INTO THE REGION FOR THE WEEKEND. ANOTHER ROUND OF MOISTURE MAY BE ON
TAP FOR THE MIDDLE OF NEXT WEEK.
&&
.UPDATE...THE LATEST OBSERVATION AND MODEL GUIDANCE TRENDS INDICATE
THERE WILL BE LITTLE TO NO CHANCE OF CONVECTION THE REST OF THE DAY
FROM CENTRAL CLARK COUNTY AND AREAS TO THE SOUTH AND WEST DUE TO
VERY STRONG SHEAR ALOFT AND INCREASINGLY DRY SOUTHWEST FLOW
SPREADING IN. ADJUSTMENTS WERE MADE TO THE POP/WX/QPF/SKY GRIDS
ACCORDINGLY. THUNDERSTORMS WILL CONTINUE TO BE FAST MOVING ACROSS
MOHAVE AND LINCOLN COUNTIES BUT TRAINING WILL BE A POSSIBILITY AND
THE FLASH FLOOD WATCH FOR THESE COUNTIES WILL REMAIN IN EFFECT
THROUGH THIS EVENING. THE REST OF THE FORECAST TRENDS AS DETAILED IN
THE PREVIOUS DISCUSSION LOOK FINE.
&&
.AVIATION...FOR MCCARRAN...DRIER AIR ALOFT SPREADING IN FROM THE
SOUTHWEST HAS DIMINISHED THE THREAT OF ADDITIONAL THUNDERSTORMS IN
THE TERMINAL AREA TODAY. NORTHEAST WINDS AROUND 10 KNOTS THROUGH
EARLY AFTERNOON WILL GIVE WAY TO SOUTHWEST WINDS WITH GUSTS OF 25-30
KTS BY MID TO LATE AFTERNOON. DRIER AND CALMER CONDITIONS ARE
EXPECTED THIS WEEKEND.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...ISOLATED TO SCATTERED THUNDERSTORMS WILL REMAIN
POSSIBLE TODAY...PRIMARILY IN AN ARC FROM THE SOUTHERN SIERRA ACROSS
CENTRA AND SOUTHEAST NEVADA INTO NORTHWEST ARIZONA. THIS LINE WILL
PUSH EAST THROUGH THE DAY WITH DRY CONDITIONS EXPECTED AREA WIDE BY
ROUGHLY 06Z SATURDAY. CIGS AROUND 6-8K FEET...GUSTY WINDS...HEAVY
RAIN WITH LOWERED VISIBILITY... STRONG TURBULENCE AND HAIL WILL ALL
BE POSSIBLE WITH STORMS. OUTSIDE OF THUNDERSTORM ACTIVITY EXPECT
GUSTY SOUTHWEST WINDS TO DEVELOP THIS AFTERNOON WITH SPEEDS OF 15-20
KTS AND GUSTS 25-30 KTS. &&
.PREV DISCUSSION...
245 AM PDT FRI AUG 7 2015
.SHORT TERM...TODAY THROUGH TONIGHT.
SIGNIFICANT MOISTURE HAS OVERSPREAD THE REGION WITH SURFACE
DEWPOINTS RANGING FROM THE UPPER 40`S ACROSS THE SOUTHERN GREAT
BASIN TO NEAR 70 ALONG THE COLORADO RIVER VALLEY NEAR LAKE HAVASU.
IPW SENSORS AND SPC MESOANALYSIS SHOW PRECIPITABLE WATER VALUES OF
1.5 TO NEARLY 2 INCHES ACROSS THE SOUTHEASTERN HALF OF THE FORECAST
AREA WHICH HAS MADE FOR EFFICIENT RAINFALL FROM STORMS OVERNIGHT.
FORTUNATELY STORM MOTION HAS BEEN AND WILL CONTINUE TO BE QUITE
RAPID AND THUS ONLY THE STRONGEST STORMS OR TRAINING STORMS HAVE
POSED A THREAT OF FLASH FLOODING. THE MAIN AREA OF ACTIVITY OVER THE
PAST 6 HOURS HAS BEEN OVER FAR EASTERN SAN BERNARDINO AND THE
SOUTHERN 2/3RDS OF MOHAVE COUNTY ASSOCIATED WITH DIVERGENCE AHEAD OF
AN APPROACHING UPPER LEVEL LOW ACTING ON A MODESTLY UNSTABLE
ATMOSPHERE. TO THE WEST OF THIS...ACTIVITY HAS BEEN MUCH WEAKER WITH
NUMEROUS WEAK SHOWERS AND VERY ISOLATED EMBEDDED THUNDERSTORMS.
VERY CHALLENGING FORECAST OVER THE NEXT 18 HOURS...ESPECIALLY WITH
RESPECT TO PRECIPITATION PLACEMENT. DRYING IS STILL EXPECTED TO
SWEEP FROM WEST TO EAST ACROSS THE REGION TODAY...WITH DRY
CONDITIONS EXPECTED AREA WIDE BY 06Z SATURDAY. HOWEVER...THE LATEST
HIGH-RES GUIDANCE HAS DELAYED DRYING ACROSS THE AREA BY 2-4 HOURS
COMPARED TO THE RUNS FROM YESTERDAY AFTERNOON AND EVENING...THIS MAY
BE IN PART DUE TO THE HIGHER THAN ANTICIPATED MOISTURE LEVELS
CURRENTLY IN PLACE. I HAVE TWEAKED THE FORECAST TO REFLECT THIS
DELAY. FOR INSTANCE...LAST EVENING IT APPEARED THAT THE BEST WINDOW
OF OPPORTUNITY FOR LAS VEGAS WOULD BE BETWEEN 11-16Z. HOWEVER THE
LATEST RUNS OF THE HRRR AND RAP HAVE SHUT MUCH OF THIS ACTIVITY
DOWN...AND HAVE BEGUN TO LATCH ON TO THE IDEA OF DELAYED DRYING. AS
A RESULT...THEY NOW INDICATE DECREASING ACTIVITY (WHICH IS CURRENTLY
BEING NOTED) BETWEEN NOW AND 16Z OR SO AND THEN AN INCREASING TREND
ALONG THE MOISTURE BOUNDARY BETWEEN 16-19Z...WITH THINGS FINALLY
PUSHING EAST OF THE VALLEY BY 22Z OR SO. MY CONFIDENCE IN THIS
SCENARIO IS MODERATE AT BEST...BUT IT DOES FIT WITH THE CURRENT
TRENDS AND OBSERVED MOISTURE IN PLACE AT THIS TIME. IN ANY
CASE...THE GENERAL THREATS WITH STORMS TODAY HAVEN`T CHANGED. THE
FLOOD THREAT WILL BE GREATEST TO THE SOUTH AND EAST OF LAS VEGAS
WHERE THE HIGHEST MOISTURE VALUES RESIDE. TO THE NORTH OF LAS VEGAS
THERE WILL BE AN INCREASED THREAT OF DAMAGING WIND GUSTS AND HAIL
DUE TO STRONG 0-6KM SHEAR AND SOMEWHAT DRIER AND COOLER AIR. IN
FACT...SPC NOW HAS A MARGINAL RISK OF SEVERE STORMS INDICATED ACROSS
THE ESMERALDA...NORTHERN NYE AND LINCOLN COUNTIES ON THEIR DAY 1
OUTLOOK DUE TO THE THREAT OF DAMAGING WINDS AND HAIL.
OUTSIDE OF THE THREAT FROM THUNDERSTORMS...WINDS COULD ALSO BE AN
ISSUE AS DRIER AT PUNCHES INTO THE REGION. THE WIND ADVISORY AND RED
FLAG WARNING IN PLACE FOR SOUTHERN/CENTRAL NYE AND FAR WESTERN CLARK
COUNTIES STILL LOOKS OK...BOTH WILL BE MARGINAL...BUT THE WIND IN
PARTICULAR IS ABNORMAL FOR THIS TIME OF YEAR SO NO CHANGES WILL BE
MADE.
.LONG TERM...SATURDAY THROUGH FRIDAY.
LATEST GUIDANCE IS TRYING TO DEVELOP SOME LIGHT PRECIP ACROSS THE
SIERRA SATURDAY AFTERNOON AND EARLY EVENING. HAVE INCREASED CLOUD
COVER FOR THIS AREA, BUT DID NOT MENTION PRECIP AT THIS TIME. WILL
MONITOR MODEL TRENDS WITH LINGERING MOISTURE IN THAT AREA THE NEXT
12 HOURS OR SO. OTHERWISE, DRY SOUTHWEST FLOW WILL TAKE HOLD THROUGH
MONDAY.
HIGH PRESSURE OVER TEXAS IS STILL ON TRACK TO EXPAND WEST TOWARD NEW
MEXICO STARTING LATE MONDAY. AT THE SAME TIME, A STRONG AREA OF LOW
PRESSURE WILL BUILD ALONG THE NORTHERN CALIFORNIA COAST. THE
COMBINATION OF THESE TWO FEATURES WILL PRODUCE SOUTHERLY FLOW OVER
OUR AREA. MOISTURE WILL TRACK NORTHWARD, MAINLY INTO MOHAVE COUNTY
TUESDAY, WITH SHOWERS AND THUNDERSTORMS POSSIBLE. SOUTHERLY FLOW
SHOULD STICK AROUND THROUGH THURSDAY, MAYBE INTO FRIDAY. MOISTURE
MAY SLIGHTLY EDGE WEST WEDNESDAY AND THURSDAY, BUT THAT WILL DEPEND
ON THE EVENTUAL POSITION OF THE WEST-COAST LOW. WITH PLENTY OF
UNCERTAINTY, DID NOT MAKE MANY CHANGES TO THE CURRENT FORECAST AT
THIS TIME.
AS FOR TEMPERATURES, MONDAY STILL APPEARS TO BE THE WARMEST DAY WITH
TEMPS A DEGREE OR TWO ABOVE NORMAL. OTHERWISE, NORMAL OR SLIGHTLY
BELOW NORMAL TEMPS ARE EXPECTED THROUGHOUT THE LONG-TERM PERIOD.
BREEZY SOUTH TO SOUTHWEST WINDS WILL BE COMMON EACH AFTERNOON AND
EARLY EVENING. WILL HAVE TO MONITOR THE EVENTUAL POSITION AND TRACK
OF THE WEST-COAST LOW AS WE COULD SEE LOCALLY WINDY CONDITIONS
ACROSS OUR NORTHERN FORECAST AREA TUESDAY THROUGH THURSDAY.
&&
.FIRE WEATHER...DRIER AIR WILL PUSH FROM WEST TO EAST ACROSS THE
REGION TODAY. THIS WILL LOWER RH`S TO CRITICAL LEVELS FRIDAY
AFTERNOON AND COMBINE WITH GUSTY WINDS ACROSS MUCH OF CENTRAL AND
SOUTHERN NYE COUNTY TO BRING CRITICAL FIRE CONDITIONS TO THE ZONE
462. IT APPEARS THAT THIS AREA HAS RECEIVED LITTLE PRECIPITATION AND
CURRENT FUEL CONDITIONS WARRANT THE RED FLAG WARNING FOR THIS
AFTERNOON INTO THIS EVENING.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTERS ARE ENCOURAGED TO REPORT
ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING
PROCEDURES.
&&
$$
UPDATE/AVIATION...ADAIR
SHORT TERM........WOLCOTT
LONG TERM.........PADDOCK
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION...UPDATED
NWS WILMINGTON NC
434 PM EDT FRI AUG 7 2015
.SYNOPSIS...
SHOWERS AND THUNDERSTORMS WILL PRECEDE AN APPROACHING COLD FRONT
THROUGH THIS EVENING. THE FRONT WILL CROSS THE COAST VERY EARLY
ON SATURDAY...USHERING DRIER AND COOLER CONDITIONS THIS WEEKEND
INTO EARLY NEXT WEEK. RAIN CHANCES WILL INCREASE TUESDAY INTO
THE MIDDLE OF NEXT WEEK...AS A FRONT STALLS ALONG OUR COAST.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 430 PM FRIDAY...QUICK FORECAST UPDATE MAINLY TO ALIGN THE
FORECAST TO EXTRAPOLATED RADAR TRENDS. THE LOW IS CENTERED NEAR
THE PENDER/BLADEN COUNTY LINE AND MOVING EASTWARD...PUSHING THE
MAIN CONVECTIVE LINE ACROSS THE WILMINGTON AREA AT THIS TIME.
BEHIND THIS FEATURE LIGHTER SHOWERS WILL PERSIST THROUGH SUNSET.
ALTHOUGH I WOULD LIKE TO END THE POTENTIAL FOR SHOWERS AT THAT
TIME...MODELS ARE QUITE INSISTENT THAT SOME WRAPAROUND CLOUDS AND
LIGHT PRECIP MAY CONTINUE OVERNIGHT...PARTICULARLY ACROSS SE NORTH
CAROLINA. DISCUSSION FROM 222 PM FOLLOWS...
SURFACE ANALYSIS PLACED THE FRONTAL BOUNDARY ALONG A LINE FROM
NEAR KINGSTREE TO ELIZABETHTOWN. LATEST HRRR GUIDANCE INDICATES
THE BOUNDARY WILL SLOW LATE THIS AFTERNOON AS IT NEARS THE COAST
BUT WILL PUSH OFFSHORE AFTER 00Z. CONVECTION WILL DIMINISH WITH
THE LOSS OF DAYTIME HEATING AND WITH INFILTRATION OF DRIER AIR
EVIDENT IN WATER VAPOR IMAGERY. WILL HANG ON TO CHANCE POPS FOR
THE COASTAL COUNTIES OF SOUTHEASTERN NC FOR A FEW HOURS AFTER
SUNSET AS A FEW LINGERING SHOWERS MAY WRAP AROUND THE DEPARTING
SURFACE LOW.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 222 PM FRIDAY...CENTRAL WEEKEND HEADLINE REMAINS ADVANCEMENT
OF AN AIR MASS CHANGE INTO THE REGION...OFFERING COOLER AND DRIER
HOURLY...MAXIMUM...MINIMUM TEMPERATURES BOTH SATURDAY AND SUNDAY.
DAYBREAK SATURDAY A SURFACE LOW WILL BECOME POSITIONED ROUGHLY 125
MILES ENE OF CAPE FEAR...RESULTING IN A SURFACE FRONT ACROSS THE
OUTER WATER...AND OFFSHORE N-NNW WINDS OVER OUR LAND ZONES. THIS
MARKS THE ONSET OF DEWPOINT DROPS THROUGHOUT MOST OF THE WEEKEND
MAKING FOR A VERY COMFORTABLE FEEL. A FEW SHOWERS MAY WRAP ON THE
BACK SIDE OF THE SURFACE LOW NEAR CAPE FEAR EARLY SATURDAY BUT A
DRYING TREND WILL PREVAIL THROUGH THE DAY.
MAXIMUMS SATURDAY 85-90...WARMEST WELL INLAND...AND 2-3 DEGREES
F WARMER SUNDAY ON MAXIMUMS. THE DRIER AIR MASS UNDER MOSTLY
CLEAR CONDITIONS WILL ALLOW OVERNIGHT TEMPERATURES TO DIP INTO
THE 60S SUNRISE SUNDAY OVER MOST AREAS...AROUND 70 SC INTERIOR.
A DEGREE OR 2 MILDER MONDAY MORNING BUT STILL PLEASANTLY VOID
OF HIGH HUMIDITY.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 222 PM FRIDAY...THE MID LEVEL RIDGE THAT HAS BEEN SITTING
OVER TEXAS FOR SOME TIME STARTS OUT THE PERIOD WITH AN EXTENSION
ACROSS THE SOUTHEAST. THE RIDGE GETS PUSHED BACK TO THE WEST AS A
STRONG SHORTWAVE MOVES ACROSS THE MIDWEST. THIS WILL LEAD TO
UNUSUALLY STRONG TROUGHING ACROSS THE SOUTHEAST THROUGH THE END OF
THE PERIOD. AT THE SURFACE HIGH PRESSURE MONDAY WILL GIVE WAY TO A
DECENT COLD FRONT ASSOCIATED WITH THE TROUGH THAT MOVES ACROSS
LATE TUESDAY AND WEDNESDAY. WE CONTINUE WITH GOOD POPS TUESDAY
LINGERING INTO WEDNESDAY. THURSDAY AND FRIDAY SHOULD SEE A DRYING
TREND. TEMPERATURES ARE A LITTLE ON THE WARM SIDE EARLY...DROPPING
TO SEASONAL NORMALS BY MID AND LATE WEEK.
&&
.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
AS OF 18Z...DYNAMIC CONDITIONS WITH DEEP MOISTURE IN PLACE. LOOK
FOR SCT SHRA AND ISOLD TSTMS TO FIRE AT ANY TIME TODAY AND
CONCENTRATED IN THE EASTERN PORTION OF THE CWA. CEILINGS AND VIS
WILL VARY FROM VFR TO POTENTIALLY LIFR IN THE HEAVIEST
ACTIVITY...BUT PREDOMINATELY MVFR. THE PRESSURE GRADIENT WILL BE
FAIRLY STRONG TODAY...WITH GUSTS OVER 20 KTS EXPECTED...STRONGER
IN CONVECTION. MOST OF THE ACTIVITY WILL END BY 00Z...WITH
ISOLATED ACTIVITY OVERNIGHT. WINDS SWING TO THE NORTH THIS EVENING
AS SURFACE LOW MOVES BY TO THE NORTHEAST. POST FRONTAL STRATUS IS
GOOD BET OVERNIGHT. SATURDAY...SLOWLY IMPROVING CONDITIONS BUT
STILL A CHANCE FOR PRECIP ALONG THE COAST.
EXTENDED OUTLOOK...PREDOMINATELY VFR SUNDAY. STORMS AGAIN MONDAY AND
TUESDAY...WITH PERIODS OF MVFR POSSIBLE. VFR WEDNESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 430 PM FRIDAY...QUICK FORECAST UPDATE TO ADJUST SHOWER AND
THUNDERSTORM CHANCES AND TIMING BASED ON RADAR TRENDS. ALSO
BUMPED UP WINDS JUST A TOUCH AHEAD OF THE CONVECTIVE LINE WHERE
THE SOUTHERLY JET AHEAD OF THE WEAK LOW NW OF WILMINGTON HAS
PRODUCED SUSTAINED WIND SPEEDS NEAR 15 KNOTS FROM FRYING PAN
SHOALS BUOY UP TO WRIGHTSVILLE BEACH. DISCUSSION FROM 222 PM
FOLLOWS...
THE COLD FRONT WAS POSITIONED NEAR A KINGSTREE TO ELIZABETHTOWN
LINE EARLY THIS AFTERNOON...AND WILL MOVE OFFSHORE AND ACROSS THE
COASTAL WATERS DURING THE EARLY EVENING HOURS. THE PRESSURE
GRADIENT ALONG AND BEHIND THE FRONT IS RELATIVELY WEAK SO EXPECT
NO ADVISORIES WILL BE REQUIRED. THE POTENTIAL FOR SCATTERED
SHOWERS AND A FEW THUNDERSTORMS WILL CONTINUE UNTIL THE FRONT
CLEARS THE COASTAL WATERS AROUND MIDNIGHT.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 222 PM FRIDAY...MAIN MARINE HEADLINE REMAINS THE PREVAILING
NORTH WIND MUCH OF THE WEEKEND IN WAKE OF A COLD FRONT AND LOW
PRESSURE SYSTEM LINGERING OVER THE OFFSHORE WATERS SATURDAY AND
SUNDAY. BECAUSE OF THE WIND TRAJECTORY...TAMEST SEA CONDITIONS
WILL RESIDE NEAR SHORE...WHEREAS FARTHER OUT AS THE FETCH LENGTH
INCREASES...SEAS WILL BECOME INCREASINGLY BUMPY IN WIND-DEVELOPED
CHOP. WINDSPEEDS WILL BEGIN TO DECREASE THROUGH SUNDAY AS THE
SURFACE LOW PULLS FARTHER EAST TO SEA AND THE LOCAL PRESSURE
GRADIENT LOOSENS-UP. BY SUNDAY NIGHT OR EARLY MONDAY WINDS WILL
SWING AROUND TO THE S-SE LIGHTLY. SLIGHTLY BUMPY SATURDAY IN THE
EARLY GOING AS RESIDUAL SSW WAVES 3-4 FT EVERY 6 SEC INTERACT
WITH NNW WIND CHOP MAKING FOR A PITCHY SPECTRUM. A FEW TSTMS MAY
IMPACT THE OFFSHORE WATERS SATURDAY...MAINLY GULF STREAM WATERS.
LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 222 PM FRIDAY...LIGHT WINDS SHOULD PREVAIL OVER THE WATERS
MONDAY UNDER A WEAK PRESSURE GRADIENT. BY TUESDAY A DECENT SOUTHWEST
FLOW SETS UP AHEAD OF A COLD FRONT MOVING ACROSS THE APPALACHIANS.
THE FRONT WILL VERY SLOWLY MOVE ACROSS THE WATERS AND IN FACT...THIS
WILL OCCUR JUST AFTER THE END OF THIS FORECAST PERIOD. WITH THE
SOUTHWEST FLOW OF 15-20 KNOTS TUESDAY...SEAS COULD INCREASE TO 3-5
FEET FOR SOME TIME OTHERWISE THE STANDARD 2-4 FEET SHOULD SUFFICE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...TRA/CRM
SHORT TERM...MJC
LONG TERM...SHK
AVIATION...DL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
222 PM EDT FRI AUG 7 2015
.SYNOPSIS...
SHOWERS AND THUNDERSTORMS WILL PRECEDE AN APPROACHING COLD FRONT
THROUGH THIS EVENING. THE FRONT WILL CROSS THE COAST VERY EARLY
ON SATURDAY...USHERING DRIER AND COOLER CONDITIONS THIS WEEKEND
INTO EARLY NEXT WEEK. RAIN CHANCES WILL INCREASE TUESDAY INTO
THE MIDDLE OF NEXT WEEK...AS A FRONT STALLS ALONG OUR COAST.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 222 PM FRIDAY...AS OF THIS AFTERNOON...SURFACE ANALYSIS
PLACED THE FRONTAL BOUNDARY ALONG A LINE FROM NEAR KINGSTREE TO
ELIZABETHTOWN. LATEST HRRR GUIDANCE INDICATES THE BOUNDARY WILL
SLOW LATE THIS AFTERNOON AS IT NEARS THE COAST BUT WILL PUSH
OFFSHORE AFTER 00Z. CONVECTION WILL DIMINISH WITH THE LOSS OF
DAYTIME HEATING AND WITH INFILTRATION OF DRIER AIR EVIDENT IN
WATER VAPOR IMAGERY. WILL HANG ON TO CHANCE POPS FOR THE COASTAL
COUNTIES OF SOUTHEASTERN NC FOR A FEW HOURS AFTER SUNSET AS A FEW
LINGERING SHOWERS MAY WRAP AROUND THE DEPARTING SURFACE LOW.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 222 PM FRIDAY...CENTRAL WEEKEND HEADLINE REMAINS ADVANCEMENT
OF AN AIR MASS CHANGE INTO THE REGION...OFFERING COOLER AND DRIER
HOURLY...MAXIMUM...MINIMUM TEMPERATURES BOTH SATURDAY AND SUNDAY.
DAYBREAK SATURDAY A SURFACE LOW WILL BECOME POSITIONED ROUGHLY 125
MILES ENE OF CAPE FEAR...RESULTING IN A SURFACE FRONT ACROSS THE
OUTER WATER...AND OFFSHORE N-NNW WINDS OVER OUR LAND ZONES. THIS
MARKS THE ONSET OF DEWPOINT DROPS THROUGHOUT MOST OF THE WEEKEND
MAKING FOR A VERY COMFORTABLE FEEL. A FEW SHOWERS MAY WRAP ON THE
BACK SIDE OF THE SURFACE LOW NEAR CAPE FEAR EARLY SATURDAY BUT A
DRYING TREND WILL PREVAIL THROUGH THE DAY.
MAXIMUMS SATURDAY 85-90...WARMEST WELL INLAND...AND 2-3 DEGREES
F WARMER SUNDAY ON MAXIMUMS. THE DRIER AIR MASS UNDER MOSTLY
CLEAR CONDITIONS WILL ALLOW OVERNIGHT TEMPERATURES TO DIP INTO
THE 60S SUNRISE SUNDAY OVER MOST AREAS...AROUND 70 SC INTERIOR.
A DEGREE OR 2 MILDER MONDAY MORNING BUT STILL PLEASANTLY VOID
OF HIGH HUMIDITY.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 222 PM FRIDAY...THE MID LEVEL RIDGE THAT HAS BEEN SITTING
OVER TEXAS FOR SOME TIME STARTS OUT THE PERIOD WITH AN EXTENSION
ACROSS THE SOUTHEAST. THE RIDGE GETS PUSHED BACK TO THE WEST AS A
STRONG SHORTWAVE MOVES ACROSS THE MIDWEST. THIS WILL LEAD TO
UNUSUALLY STRONG TROUGHING ACROSS THE SOUTHEAST THROUGH THE END OF
THE PERIOD. AT THE SURFACE HIGH PRESSURE MONDAY WILL GIVE WAY TO A
DECENT COLD FRONT ASSOCIATED WITH THE TROUGH THAT MOVES ACROSS
LATE TUESDAY AND WEDNESDAY. WE CONTINUE WITH GOOD POPS TUESDAY
LINGERING INTO WEDNESDAY. THURSDAY AND FRIDAY SHOULD SEE A DRYING
TREND. TEMPERATURES ARE A LITTLE ON THE WARM SIDE EARLY...DROPPING
TO SEASONAL NORMALS BY MID AND LATE WEEK.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 18Z...DYNAMIC CONDITIONS WITH DEEP MOISTURE IN PLACE. LOOK
FOR SCT SHRA AND ISOLD TSTMS TO FIRE AT ANY TIME TODAY AND
CONCENTRATED IN THE EASTERN PORTION OF THE CWA. CEILINGS AND VIS
WILL VARY FROM VFR TO POTENTIALLY LIFR IN THE HEAVIEST
ACTIVITY...BUT PREDOMINATELY MVFR. THE PRESSURE GRADIENT WILL BE
FAIRLY STRONG TODAY...WITH GUSTS OVER 20 KTS EXPECTED...STRONGER
IN CONVECTION. MOST OF THE ACTIVITY WILL END BY 00Z...WITH
ISOLATED ACTIVITY OVERNIGHT. WINDS SWING TO THE NORTH THIS EVENING
AS SURFACE LOW MOVES BY TO THE NORTHEAST. POST FRONTAL STRATUS IS
GOOD BET OVERNIGHT. SATURDAY...SLOWLY IMPROVING CONDITIONS BUT
STILL A CHANCE FOR PRECIP ALONG THE COAST.
EXTENDED OUTLOOK...PREDOMINATELY VFR SUNDAY. STORMS AGAIN MONDAY AND
TUESDAY...WITH PERIODS OF MVFR POSSIBLE. VFR WEDNESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 222 PM FRIDAY...THE COLD FRONT WAS POSITIONED NEAR A
KINGSTREE TO ELIZABETHTOWN LINE EARLY THIS AFTERNOON...AND WILL
MOVE OFFSHORE AND ACROSS THE COASTAL WATERS DURING THE EARLY
EVENING HOURS. THE PRESSURE GRADIENT ALONG AND BEHIND THE FRONT IS
RELATIVELY WEAK SO EXPECT NO ADVISORIES WILL BE REQUIRED. THE
POTENTIAL FOR SCATTERED SHOWERS AND A FEW THUNDERSTORMS WILL
CONTINUE UNTIL THE FRONT CLEARS THE COASTAL WATERS AROUND
MIDNIGHT.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 222 PM FRIDAY...MAIN MARINE HEADLINE REMAINS THE PREVAILING
NORTH WIND MUCH OF THE WEEKEND IN WAKE OF A COLD FRONT AND LOW
PRESSURE SYSTEM LINGERING OVER THE OFFSHORE WATERS SATURDAY AND
SUNDAY. BECAUSE OF THE WIND TRAJECTORY...TAMEST SEA CONDITIONS
WILL RESIDE NEAR SHORE...WHEREAS FARTHER OUT AS THE FETCH LENGTH
INCREASES...SEAS WILL BECOME INCREASINGLY BUMPY IN WIND-DEVELOPED
CHOP. WINDSPEEDS WILL BEGIN TO DECREASE THROUGH SUNDAY AS THE
SURFACE LOW PULLS FARTHER EAST TO SEA AND THE LOCAL PRESSURE
GRADIENT LOOSENS-UP. BY SUNDAY NIGHT OR EARLY MONDAY WINDS WILL
SWING AROUND TO THE S-SE LIGHTLY. SLIGHTLY BUMPY SATURDAY IN THE
EARLY GOING AS RESIDUAL SSW WAVES 3-4 FT EVERY 6 SEC INTERACT
WITH NNW WIND CHOP MAKING FOR A PITCHY SPECTRUM. A FEW TSTMS MAY
IMPACT THE OFFSHORE WATERS SATURDAY...MAINLY GULF STREAM WATERS.
LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 222 PM FRIDAY...LIGHT WINDS SHOULD PREVAIL OVER THE WATERS
MONDAY UNDER A WEAK PRESSURE GRADIENT. BY TUESDAY A DECENT SOUTHWEST
FLOW SETS UP AHEAD OF A COLD FRONT MOVING ACROSS THE APPALACHIANS.
THE FRONT WILL VERY SLOWLY MOVE ACROSS THE WATERS AND IN FACT...THIS
WILL OCCUR JUST AFTER THE END OF THIS FORECAST PERIOD. WITH THE
SOUTHWEST FLOW OF 15-20 KNOTS TUESDAY...SEAS COULD INCREASE TO 3-5
FEET FOR SOME TIME OTHERWISE THE STANDARD 2-4 FEET SHOULD SUFFICE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...CRM
SHORT TERM...MJC
LONG TERM...SHK
AVIATION...DL/CRM
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1251 PM CDT FRI AUG 7 2015
.UPDATE...
ISSUED AT 1242 PM CDT FRI AUG 7 2015
FRONTAL BOUNDARY SITUATED FROM AROUND HARVEY TO BISMARCK EARLY
THIS AFTERNOON. STILL A CHANCE OF A SHOWER OR THUNDERSTORM SOUTH
AND EAST OF THE FRONT THIS AFTERNOON. LATEST HRRR ITERATION IS
INDICATING CONVECTION DEVELOPING AROUND ASHLEY TO EDGELEY AND
ELLENDALE AROUND 20-21 UTC. INCREASING INSTABILITY OVER THIS AREA
WITH MLCAPES AROUND 1000-1500 J/KG ALONG THE SOUTH DAKOTA BORDER
AND 40 KNOTS OF BULK SHEAR. WILL NEED TO MONITOR THIS AREA FOR
STRONG CONVECTION YET THIS AFTERNOON. OTHERWISE...MOSTLY SUNNY
SKIES EARLY THIS AFTERNOON. EXPECT INCREASING CLOUDS AND WINDS
ACROSS THE NORTH ASSOCIATED WITH THE UPPER LEVEL LOW IN SOUTHERN
CANADA. CURRENT FORECAST HAS A GOOD HANDLE ON THIS.
UPDATE ISSUED AT 918 AM CDT FRI AUG 7 2015
SURFACE AND UPPER LEVEL LOW OVER SOUTHEAST SASKATCHEWAN WITH A
COLD FRONT MOVING THROUGH CENTRAL NORTH DAKOTA. SCATTERED SHOWERS
AND ISOLATED THUNDER ALONG THE FRONT WILL TRACK ACROSS CENTRAL
NORTH DAKOTA THIS MORNING. WILL KEEP THE THREAT OF THUNDER OVER
THE SOUTHEAST CWA INTO THE AFTERNOON WITH FRONT LAGGING HERE AND
MOVING INTO A MORE UNSTABLE AIRMASS. FOR THE MORNING UPDATE...MAIN
MAIN CHANGE WAS CLOUDS AND POPS BASED ON LATEST SATELLITE AND
RADAR. ALSO...FOG HAS RAPIDLY DISSIPATED DURING THE PAST HOUR OR
SO.
UPDATE ISSUED AT 618 AM CDT FRI AUG 7 2015
FOG IS CLEARLY EVIDENT VIA WEBCAMS THIS MORNING. THE LAYER IS
QUITE THIN AS THE MOON IS VISIBLE WHEN LOOKING UP...DESPITE LESS
THAN 1/4 MILE VISIBILITY WHEN LOOKING HORIZONTALLY. LIGHT
PRECIPITATION MOVING THROUGH SOUTH CENTRAL SHOULD DISSIPATE FOG
RAPIDLY THIS MORNING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM CDT FRI AUG 7 2015
FORECAST HIGHLIGHT IN THE SHORT TERM PERIOD IS FOG THIS MORNING.
CURRENTLY...ZONAL FLOW ALOFT WITH DEEP LOW PRESSURE OVER FAR
SOUTH CENTRAL CANADA AND RIDGING OVER THE SOUTHERN AND CENTRAL
PLAINS. BAND OF SHOWERS OVER SOUTHEAST MONTANA STRETCHING EASTWARD
INTO FAR SOUTHWEST NORTH DAKOTA ALONG A COLD FRONTAL BOUNDARY AND
UNDERNEATH AN UPPER JET. HIGH RES MODELS CONTINUE TO BRING THIS
PRECIPITATION INTO MY SOUTHWEST NOW THROUGH 10Z...SPREADING EAST
INTO MY SOUTH CENTRAL COUNTIES THROUGH THE AM HOURS. A FEW
LIGHTNING STRIKES BUT WILL KEEP THUNDER OUT OF THE MORNING
FORECAST WITH LITTLE TO NO CAPE ACROSS SOUTHERN NORTH DAKOTA.
AREAS OF FOG MAINLY OVER NORTHWESTERN...CENTRAL AND EASTERN
PORTIONS OF THE STATE. LATEST HRRR VISIBILITY OUTPUT INDICATES FOG
PERSISTING UNTIL 12-15Z THIS MORNING ACROSS THE AFOREMENTIONED
AREAS. HRRR DOES REMOVE FOG NORTHWEST WHERE WE CURRENTLY HAVE
INCREASING UPPER CLOUDS AND WHERE WINDS WILL SHIFT TO SOUTHWEST
PROMOTING DRY AIR ADVECTION. WITH VISIBILITIES COMING UP AND DOWN
OPTING TO GO WITH A SPECIAL WEATHER STATEMENT FOR NOW HIGHLIGHTING
THE FOG VERSUS HEADLINES.
CHANCES FOR PRECIPITATION WILL CONTINUE TO MOVE EAST ACROSS THE
SOUTH NEAR THE COLD FRONTAL BOUNDARY TODAY INTO THE EVENING HOURS
WHEN FORCING ALOFT WILL BE PRESENT WITH THE UPPER JET. WILL
MENTION THUNDER POTENTIAL IN THE AFTERNOON AND EVENING WHEN
DAYTIME HEATING WILL RESULT IN DIURNAL INSTABILITY. FORCING
DECREASING LATER THIS EVENING SO WENT DRY OVERNIGHT. BREEZY ACROSS
THE NORTH TODAY NEAR THE UPPER LOW...SUB WIND ADVISORY MAGNITUDES.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 322 AM CDT FRI AUG 7 2015
THE MAIN FORECAST FOCUS IS ON THE POTENTIAL FOR PRECIPITATION ALONG
AND SOUTH OF I-94 THIS WEEKEND.
FAR SOUTHERN NORTH DAKOTA AND THE NORTHERN THIRD OF SOUTH DAKOTA ARE
THE CONSENSUS HOT SPOT FOR CONVECTION SATURDAY NIGHT AND
SUNDAY...ACCORDING TO THE 00 UTC GFS/ECMWF/GEFS/GEM GLOBAL
CONSENSUS. THUNDERSTORMS WILL LIKELY MOVE SLOWLY...BUT FLOOD RISK IS
LOW GIVEN LACK OF ANOMALOUS PRECIPITABLE WATER AND RECENT
DEMONSTRATION THAT SOILS CAN HANDLE OVER TWO INCHES PER HOUR WITHOUT
FLASH FLOODING.
IN ITS WAKE...THERE IS GENERAL CONSENSUS AMONG THE 00 UTC
GFS/ECMWF/GEFS/GEM GLOBAL SUITE THAT COMPLEX UPPER LEVEL FLOW WILL
EVOLVE INTO A SIMPLER WEST COAST TROUGH WITH AMPLIFIED RIDGING OVER
THE GREAT PLAINS BY MONDAY MORNING. ASSOCIATED BROAD SCALE
SUBSIDENCE SHOULD BE SUFFICIENT TO SQUELCH CONVECTION UNTIL AT LEAST
WEDNESDAY MORNING. UNCERTAINTY INCREASES THEREAFTER AS SEVERAL
ENSEMBLE MEMBERS EJECT SHORTWAVE ENERGY INTO EASTERN MONTANA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1242 PM CDT FRI AUG 7 2015
VFR CONDITIONS EXPECTED THROUGH THE FORECAST PERIOD. SCATTERED
THUNDERSTORMS POSSIBLE OVER SOUTHEAST NORTH DAKOTA THIS AFTERNOON
BUT AT THIS TIME THINK BEST CHANCES WILL REMAIN SOUTH AND EAST OF
KJMS...THUS NO MENTION OF THUNDER FOR THE KJMS TAF.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TWH
SHORT TERM...NH
LONG TERM...SCHECK
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1235 PM CDT FRI AUG 7 2015
.UPDATE...
ISSUED AT 1235 PM CDT FRI AUG 7 2015
MADE SOME MINOR ADJUSTMENTS TO CLOUD AND PCPN TRENDS FOR THIS
UPDATE. STILL WATCHING WAVE MOVG ACROSS SRN CANADA AND SFC TROF
ACROSS ND FOR DEVELOPMENT OF LATE AFTERNOON AND EVENING
CONVECTION...AND CURRENT TIMING STILL LOOKS GOOD. REST OF FCST
REMAINS ON TARGET.
UPDATE ISSUED AT 954 AM CDT FRI AUG 7 2015
BASED ON CURRENT TRENDS...INCREASED SKY COVER OVER THE AREA AND
ADDED SOME -RW OVER ERN ND. CURRENT RADAR SHOWS A BAND OF SHOWERS
MOVG INTO THE DVL BASIN AND EXPECT THEM TO CONTINUE E THRU THE
MORNING INTO THE EARLY AFTERNOON HOURS. OTHERWISE...REST OF FCST
LOOKS GOOD.
UPDATE ISSUED AT 632 AM CDT FRI AUG 7 2015
AREAS OF DENSE FOG REMAIN...BUT CONDITIONS APPEAR TO BE SLOWLY
IMPROVING. MAIN CONCERN IS STILL SEVERE POTENTIAL THIS AFTERNOON.
LATEST HRRR DEVELOPS STORMS BY 19Z-20Z...BUT IS USUALLY TOO QUICK
WITH BREAKING THE CAP AND WILL STICK WITH AFTER 21Z TIMING. WILL
NEED TO MONITOR MESOANALYSIS THROUGH THE MORNING TO DETERMINE
EXTENT OF SEVERE POTENTIAL.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 345 AM CDT FRI AUG 7 2015
PATCHY FOG ACROSS THE REGION THIS MORNING WILL DISSIPATE JUST
AFTER SUNRISE.
MAIN CONCERN WILL BE SEVERE POTENTIAL FOR THIS AFTERNOON. STRONG
UPPER LOW ACROSS SOUTHERN CANADA WILL CONTINUE TO PROPAGATE
EASTWARD...SENDING A SFC TROUGH THROUGH THE REGION THIS AFTERNOON.
MLCAPE AHEAD OF THIS FEATURE EXPECTED TO REACH NEAR 2000 J/KG.
SFC CONVERGENCE WILL BE RELATIVELY WEAK (WITH STRONGEST FORCING
REMAIN ACROSS CANADA)...AND COVERAGE OF STORMS WILL BE LIMITED TO
ISOLD/SCT. HOWEVER...GIVEN 0-6KM BULK SHEAR 35-40 KNTS...ANY
STORM THAT DOES INITIATE WILL HAVE THE POTENTIAL TO BECOME SEVERE.
SPC INDICATES A MARGINAL RISK FOR SEVERE STORMS CLOSER TO THE
INTERNATIONAL BORDER...WHICH IS CLOSER TO THE UPPER LOW.
THE NEXT UPPER WAVE WILL APPROACH THE REGION FROM THE SOUTHWEST ON
SATURDAY...BRINING THUNDER CHANCES TO THE SOUTHERN FA (ALONG WITH
STALLED SFC TROUGH). MOST GUIDANCE SUGGESTS STRONGER INSTABILITY
WILL REMAIN SOUTH OF THE REGION...SIGNIFICANTLY LIMITING SEVERE
POTENTIAL.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 345 AM CDT FRI AUG 7 2015
SATURDAY NIGHT-SUNDAY NIGHT...MOST GUIDANCE SUGGESTS HIGH PRESSURE
AND A DRIER AIRMASS WILL BE IN PLACE BY SUNDAY ACROSS THE
REGION...LEADING TO DRY WEATHER. THE OUTLIER IS THE ECMWF WHICH
ATTEMPTS TO MOVE AN UPPER WAVE INTO THE REGION ON SUNDAY. KEPT LOW
POPS ACROSS SE ND...ALTHOUGH ANY ACTIVITY SHOULD REMAIN WEAK GIVEN
THE VERY WEAK INSTABILITY THE MODELS ARE INDICATING.
MONDAY-THURSDAY...EXTENDED PERIOD FEATURES MAINLY DRY CONDITIONS
AT LEAST THROUGH WEDNESDAY AS AN UPPER RIDGE DOMINATES THE HIGH
PLAINS AND EDGES TOWARD THE FORECAST AREA WITH TIME. THIS WILL
TRANSLATE TO SURFACE TEMPERATURES IN THE SEASONALLY WARM LOW TO
MID EIGHTIES DURING THE MIDDLE OF THE WEEK. UPPER LOW ANCHORED
VICINITY OF PACIFIC NORTHWEST WILL MOVE SLOWLY TO THE EAST...SHORT
WAVE(S) OUT AHEAD COULD AFFECT OUR AREA WITH RW/TRW ACTIVITY BY
THURSDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1235 PM CDT FRI AUG 7 2015
SOME BRIEF MVFR CU CIGS CAN BE EXPECTED GENERALLY EAST OF THE VALLEY
EARLY THIS AFTERNOON BEFORE LIFTING INTO VFR RANGE AND SCATTERING BY
LATE AFTERNOON. TSRA PSBL LATE AFTERNOON AND EARLY EVENING MAINLY
OVER THE FAR NORTH HOWEVER FAVORED GUIDANCE SHOWING ANY TSRA ISOLD
SO FOR NOW WILL OMIT FROM TAFS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...HOPKINS
SHORT TERM...TG
LONG TERM...WJB/TG
AVIATION...VOELKER
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
312 PM CDT FRI AUG 7 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 312 PM CDT FRI AUG 7 2015
SEVERAL CONCERNS WITH THE FORECAST DURING THIS PERIOD. THE FIRST
COMES TONIGHT AND WHETHER THERE WILL BE ANY VALLEY FOG OR NOT. IN
FAVOR OF THE FOG FORMING IS THE LITTLE BIT OF RAIN THIS MORNING
AND THE CLOUDS THAT HAVE TRAPPED THIS MOISTURE. THE 07.12Z NAM IS
THE MOST AGGRESSIVE WITH SHOWING SATURATION OCCURRING AT THE
SURFACE FOR THE VALLEY LOCATIONS. THE NAM ALSO HAS THE MOST AMOUNT
OF WIND JUST ABOVE THE SURFACE FOR MORE MIXING...WHICH GOES
AGAINST FOG FORMATION. 07.17Z RAP SOUNDINGS WHILE HAVING A DEEPER
LAYER OF LIGHT WINDS...COMES CLOSE TO SATURATING AT THE SURFACE
AND THEN REALLY DRIES OUT JUST ABOVE THE SURFACE. THE 07.12Z GFS
IS EVEN DRIER THAN THE RAP...SO HAVE DOUBTS THAT THERE WILL BE A
LOT OF FOG IN THE VALLEYS TONIGHT. ANOTHER COMPLICATING FACTOR
COULD BE THE INCREASE IN HIGH LEVEL CLOUDS FOR LATE TONIGHT AHEAD
OF AN APPROACHING SHORT WAVE TROUGH. PATCHY VALLEY FOG WAS ALREADY
IN THE FORECAST AND DO NOT PLAN TO MAKE ANY CHANGES TO THIS.
WITH THE APPROACHING SHORT WAVE TROUGH...THE GFS SEEMS TO HAVE THE
MOST SUPPORT FROM THE OTHER MODELS WITH THE 07.12Z ECMWF LOOKING
SIMILAR ALONG WITH THE 07.12Z HI-RES ARW AND NMM. WATER VAPOR
SATELLITE INDICATES THIS WAVE IS COMING OUT OF THE ROCKIES OVER
EASTERN WYOMING AND NORTHERN COLORADO THIS AFTERNOON AND SHOULD
THEN TRACK EAST ACROSS IOWA INTO SOUTHERN WISCONSIN AND NORTHERN
ILLINOIS BY LATE SATURDAY MORNING. THE GFS SUGGESTS THIS WAVE WILL
PRODUCE SOME WEAK TO MODERATE PV ADVECTION IN THE 500-300 MB LAYER
ACROSS NORTHEAST IOWA INTO FAR SOUTHERN WISCONSIN LATE TONIGHT
INTO EARLY SATURDAY MORNING. THE BOUNDARY THAT WENT THROUGH TODAY
SHOULD BE HUNG UP OVER CENTRAL IOWA AND IT IS EXPECTED THAT WEAK
TO MODERATE FRONTOGENESIS WILL OCCUR NORTH OF THIS BOUNDARY. THE
BEST ISENTROPIC UP GLIDE ON THE 310K SURFACE IS EXPECTED TO
REMAIN SOUTH OF THE BOUNDARY ACROSS CENTRAL AND SOUTHERN IOWA WITH
POSSIBLY 1 TO 2 UBAR/S OVER NORTHEAST IOWA. THE GENERAL CONSENSUS
AMONG THE MODELS IS THAT A COMPLEX OF SHOWERS AND STORMS SHOULD
FORM OVER NEBRASKA TONIGHT AND MOVE EAST ALONG AND NORTH OF THE
BOUNDARY. THE GFS AND HI-RES ARW AND NMM WOULD SUGGEST THERE IS AT
LEAST A CHANCE THAT THIS COMPLEX SURVIVES LONG ENOUGH TO GET INTO
THE SOUTHERN PARTS OF THE FORECAST AREA WHILE THE 07.12Z ECMWF
STARTS TO DISSIPATE THE COMPLEX AND ONLY BRINGS IN SOME REMAINS
SATURDAY AFTERNOON ACROSS THE SOUTH. WILL BRING IN SOME 20 TO 40
PERCENT CHANCES ACROSS NORTHEAST IOWA SATURDAY MORNING FOR THIS
COMPLEX.
ANOTHER SHORT WAVE TROUGH IS THEN EXPECTED TO COME OUT OF THE
ROCKIES AND TRACK ACROSS THE REGION SATURDAY NIGHT. THE TRACK AND
FORCING LOOK TO BE VERY SIMILAR TO THE WAVE FOR LATE TONIGHT INTO
SATURDAY MORNING WITH THE EXCEPTION THAT THE SURFACE BOUNDARY
SHOULD GET PUSHED FARTHER SOUTH INTO SOUTHERN IOWA OR NORTHERN
MISSOURI. THE COMPLEX OF STORMS WITH THIS NEXT WAVE IS EXPECTED TO
FORM OVER SOUTHWEST IOWA AND THEN TRACK EAST AND SHOULD LARGELY
STAY TO THE SOUTH OF THE FORECAST AREA. THE GFS IS SLIGHTLY
FARTHER NORTH THAN THE ECMWF AND TO HONOR THIS WILL HAVE SOME 20
TO 40 PERCENT CHANCES FROM ABOUT INTERSTATE 90 SOUTH.
BY SUNDAY NIGHT THE MEAN RIDGE WILL BE TRYING TO BUILD OVER THE
ROCKIES WITH AN UPPER LEVEL LOW OVER NORTHERN ONTARIO. THIS WILL
START TO SET UP A NORTHWEST FLOW OVER THE REGION WITH THE
POSSIBILITY OF A WEAK SHORT WAVE TROUGH ROTATING AROUND THE UPPER
LEVEL LOW AND ACROSS THE AREA. THE FORCING WITH THIS WAVE LOOKS TO
BE RATHER WEAK...BUT IT COULD PUSH A WEAK SURFACE BOUNDARY INTO
THE AREA WITH THE POSSIBILITY OF SOME ACTIVITY ALONG IT. WILL
CARRY SOME 30 TO 40 PERCENT CHANCES SUNDAY FOR THIS FEATURE WITH
SOME LINGERING 20 TO 30 PERCENT CHANCES INTO SUNDAY NIGHT.
.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 312 PM CDT FRI AUG 7 2015
ONCE THE SHORT WAVE TROUGH FROM SUNDAY NIGHT EXITS THE AREA...A
LARGE AREA OF HIGH PRESSURE WILL BUILD IN OVER THE UPPER MIDWEST.
THIS HIGH LOOKS TO DOMINATE THE REGION FROM MONDAY NIGHT THROUGH
WEDNESDAY NIGHT. THE ECMWF WOULD SUGGESTS IT HOLDS TIGHT OVER THE
REGION THROUGH THE END OF THE WEEK WHILE THE GFS BRINGS A COLD
FRONT ACROSS THE UPPER MIDWEST THURSDAY THROUGH FRIDAY. WILL JUST
CARRY SOME LOW 20 TO 30 PERCENT RAIN CHANCES LATE IN THE PERIOD TO
HONOR THE GFS SOLUTION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1250 PM CDT FRI AUG 7 2015
WITH SHOWERS AND THUNDERSTORMS FROM THIS MORNING NOW WELL EAST OF
TAF AIRFIELDS AND CEILINGS RISING ABOVE 3000 FT AGL...EXPECT VFR
CONDITIONS AT KRST/KLSE THROUGH AT LEAST 08.06Z. SCT-BKN AFTERNOON
CU WILL BREAK UP AND DISSIPATE LATER THIS EVENING...LEAVING MOSTLY
CLEAR SKIES FOR THE LATE EVENING INTO THE EARLY MORNING HOURS.
WEST-NORTHWEST WINDS FROM 8 TO 12 KTS WILL DECREASE SOON AFTER
SUNSET...BECOMING LIGHT THIS EVENING.
PRIMARY CONCERN TONIGHT WILL BE FOG POTENTIAL...ESPECIALLY AT
KLSE. VARIOUS FORECAST GUIDANCE DIFFERS ON THE DEPTH OF LIGHT
WINDS OVERNIGHT AS WELL AS THE DEGREE OF INCREASING MID-HIGH
CLOUDS DURING THE CRITICAL 09-13Z PERIOD. IF CLOUDS ARE SLOWER TO
MOVE INTO THE REGION AND A DEEP LAYER OF LIGHT WIND MATERIALIZES...
FOG CHANCES INCREASE GREATLY. FOR NOW...NOT ENOUGH CONFIDENCE TO
INTRODUCE IFR CONDITIONS IN FOG AND WILL KEEP 4SM/BR AT KLSE
BEGINNING AT 08.10Z. WILL ALLOW FUTURE SHIFTS TO MONITOR
CONDITIONS AND ADJUST AS NECESSARY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...ROGERS
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1205 PM CDT FRI AUG 7 2015
UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE
.UPDATE...
ISSUED AT 1205 PM CDT FRI AUG 7 2015
THE LARGE SHIELD OF RAIN HAS MOVED INTO THE NORTHEASTERN QUARTER
OF WISCONSIN WITH LOCALLY HEAVY RAIN FALLING AT TIMES. A FEW
LOCATIONS IN CENTRAL WISCONSIN HAVE ALREADY EXCEEDED AN INCH OF
RAIN BEFORE NOON. A RELATIVELY STABLE ATMOSPHERE APPEARS TO BE
SUPPRESSING THUNDER POTENTIAL...BUT A SMALL HANDFUL OF STRIKES
HAVE BEEN DETECTED THROUGH THE MORNING IN THE SOUTHERN TIER OF THE
CWA. TO THIS POINT...THE HEAVIEST RAIN ALSO SEEMS CONFINED TO THE
SOUTH...AND FORECAST UPDATES THROUGH THE MORNING HAVE ATTEMPTED
TO REFLECT THIS. MESO MODELS CONTINUE TO INSIST ON DEVELOPMENT OF
HEAVIER RAIN IN NORTHEAST WISCONSIN THIS AFTERNOON...AND IN
DEFERENCE TO THEIR CONSISTENCY WILL NOT TOTALLY ABANDON THAT
POTENTIAL IN FORECAST THERE YET. BUT TO THIS POINT...RAIN THERE
HAS BEEN LIGHTER AND MORE SCATTERED.
&&
.SYNOPSIS...
ISSUED AT 406 AM CDT FRI AUG 7 2015
MUCH NEEDED RAINFALL EXPECTED FOR MOST OF THE AREA TODAY.
THE POSN OF THE MAIN LARGE-SCALE FEATURES WL CHG LITTLE DURING THE
FCST PERIOD...WITH TROF POSNS NEAR THE COASTS AND RIDGING ACRS
THE CENTRAL PART OF THE CONTINENT. THE MAIN WESTERLIES ACRS THE
NRN CONUS CURRENTLY ARE RATHER LOW-AMPLITUDE...AS A SERIES OF
SHRTWVS IS DISTORTING THE MID-CONUS RIDGE. THE MAIN CHG DURING THE
FCST PERIOD WL BE A MARKED AMPLIFICATION OF THE RIDGE NEXT WEEK.
TEMPS WL NOT VARY TOO MUCH FM SEASONAL NORMALS. THE MAIN
OPPORTUNITIES FOR PCPN WL OCCUR TDA AND DURING THE LATTER PART OF
THE WEEKEND. AFTER TDA/S SYSTEM EXITS THE AREA...PCPN AMNTS WL
PROBABLY BE BLO NORMAL FOR THE REST OF THE PERIOD.
&&
.SHORT TERM...TODAY...TONIGHT...AND SATURDAY
ISSUED AT 406 AM CDT FRI AUG 7 2015
FCST FOCUS IS ON SHARS-LIKE SYSTEM CROSSING THE AREA TDA. THE
SYSTEM PRODUCED SIG WX TO OUR W YDA...WITH SEVERAL TORNADOES
APPARENTLY OCCURRING IN MN...AND HVY RAIN IN SOME PLACES AS WELL.
THE SYSTEM IS MOVG OUT OF THE AXIS OF GREATEST MOISTURE AND
INSTABILITY...SO AN EXACT REPEAT IS UNLIKELY ACRS OUR AREA TDA.
STILL...THE SYSTEM WL ACT ON INCRG MOISTURE TO GENERATE FAIRLY
WIDESPREAD SHRA ACRS THE FCST AREA TDA. BASED ON EXTRAP OF RADAR
AND STLT IMAGERY...NEARLY CLOSED UPR SHRTWV WL DRIVE EWD RIGHT
ACRS THE FCST AREA. COMMA-HEAD STRUCTURE WL LIKELY TRACK ACRS
N-C/NE WI...GENERALLY N OF HIGHWAY 29...RESULTING IN A WIDESPREAD
SOAKING RAINFALL ACRS THE N. WIDESPREAD CLDS AND PCPN WL GREATLY
LIMIT DESTABILIZATION...AND SUPPORT ONLY ISOLD THUNDER. BUT WL
NEED TO KEEP A CLOSE WATCH ON THE FAR SRN PART OF THE FCST AREA.
ALTHOUGH UNLIKELY...IF SUFFICIENT BREAKS IN THE CLDS WERE TO
DEVELOP FOR DESTABILIZATION TO OCCUR...CONDITIONS COULD BECOME
FAVORABLE FOR LOW-TOPPED SUPERCELLS.
ADDED HVY RAINFALL ATTRIBUTE TO THE GRIDS...NOT BECAUSE OF THE
POTENTIAL FOR TORRENTIAL RAINS WITH TSTMS...BUT MORE FOR EFFICIENT
SHRA/TSRA THAT COULD PERSIST FOR SEVERAL HRS AS THE COMMA HEAD
STRUCTURE PUSHES ACRS THE AREA. SOME RUNS OF THE HRRR PRODUCED
RAINFALLS OF UP TO 3.5 INCHES ACRS PORTIONS OF THE FCST AREA. A
WIDESPREAD 1-2 INCH RAINFALL ACRS THE N SEEMS MORE LIKELY...WITH A
FEW LOCATIONS POSSIBLY EXCEEDING 2 INCHES. THE DURATION OF THE
RAINFALL SEEMS TO FAVOR MAINLY PONDING OF WATER IN LOW-LYING AREAS
RATHER THAN FLASH FLOODING. WL DETAIL SITN IN THE HWO.
TIMING THE ENDING OF THE PCPN WAS DIFFICULT. BACK EDGE OF PCPN WAS
STILL MAKING STEADY EWD PROGRESS EARLY THIS MORNING...AND PURE
EXTRAPOLATION WOULD TAKE IT OUT OF THE ARE MUCH FASTER THAN
DEPICTED ON THE MODELS. SUSPECT SYSTEM WL SLOW A BIT AS UPR
SPEED MAX BECOMES SITUATED MORE ON THE UPSTREAM SIDE OF THE
TROF...AND SOME ADDITIONAL PCPN DEVELOPMENT WL EVENTUALLY OCCUR
ALONG THE TRAILING EDGE OF THE SYSTEM. BUILT POP GRIDS WITH
CATEGORICAL POPS SHIFTG THROUGH THE N DURING THE DAY...BUT
LINGERED SCT/ISOLD POPS BACK TO THE SW WELL INTO TNGT. TEMPS TDA
NOT LIKELY TO RISE VERY FAR WITH WIDESPREAD CLDS AND PCPN.
EXPECT SOME FOG TO DEVELOP OVERNIGHT. THERE COULD ALSO BE QUITE A
BIT OF LINGERING LOW CLD COVER. IF BREAKS IN THE LOW CLDS ARE MORE
SIG THAN EXPECTED...DENSE FOG COULD BECOME A PROBLEM.
QUIET WX EXPECTED SAT AS THE NEXT SYSTEM WL FIRST BE APPROACHING
FM THE W. SLOWED THE ARRIVAL OF THE POPS WITH THAT SYSTEM FM WHAT
WAS IN PREV FCST.
.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY
ISSUED AT 406 AM CDT FRI AUG 7 2015
A PATTERN SHIFT IS EXPECTED BY EARLY NEXT WEEK AS 500MB RIDGE
BUILDS ACROSS THE ROCKIES AND TROUGH DEEPENS ACROSS EASTERN
CANADA. THIS WILL LEAVE THE REGION IN A NORTHWEST FLOW PATTERN.
TEMPERATURES WILL TREND TOWARDS BELOW NORMAL READINGS BY THE
MIDDLE OF NEXT WEEK BEFORE REBOUNDING LATE IN THE WEEK AHEAD
OF A COLD FRONT.
MAIN CONCERN WILL BE THE TIMING OF PRECIPITATION CHANCES SATURDAY
NIGHT INTO SUNDAY NIGHT AS A COLD FRONT MOVES THROUGH THE AREA.
MODELS IN BETTER AGREEMENT WITH TIMING OF PRECIPITATION. CHANCES
FOR SHOWERS AND STORMS WILL INCREASE LATER SATURDAY NIGHT...WITH
THE BEST CHANCE FOR SHOWERS AND STORMS SUNDAY INTO SUNDAY EVENING
AS FRONT MOVES THROUGH THE REGION. MAIN CONCERN WILL THE
POSSIBILITY OF LOCALLY HEAVY RAIN. ENOUGH LINGERING MOISTURE AND
WEAK DISTURBANCE MOVING ACROSS THE REGION ON MONDAY COULD TRIGGER
AN ISOLATED SHOWER OR STORM ACROSS NORTHEAST OR EAST-CENTRAL
WISCONSIN. ANOTHER DISTURBANCE DROPPING SOUTHEAST OUT OF CANADA
NEEDS TO BE WATCHED FOR TUESDAY INTO TUESDAY AFTERNOON. LATEST
ECMWF DOES DEPICT PRECIPITATION DURING THIS PERIOD. WILL WAIT
FOR A FEW MORE MODEL RUNS TO SEE IF THIS SCENARIO IS STILL
DEPICTED BEFORE ADDING A CHANCE OF PRECIPITATION DURING THIS
PERIOD. OTHERWISE...DRY CONDITIONS WILL PREVAIL THROUGH THURSDAY.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1205 PM CDT FRI AUG 7 2015
FLIGHT CONDITIONS HAVE GENERALLY DETERIORATED AS EXPECTED
TODAY...BUT HAVE BEEN FLUCTUATING WITH RAIN INTENSITY THROUGH THE
MORNING. CONDITIONS ARE EXPECTED TO REMAIN POOR TONIGHT...AND LOW
CIGS/VIS SHOULD BE EXPECTED BEHIND THE RAIN. GUIDANCE SUGGESTS
SEVERAL HOURS OF DENSE FOG FOR THE WESTERN SITES OVERNIGHT. THIS
MAY BE OVERKILL...BUT FOG IS A TRICKY BEAST...AND WILL INTRODUCE
A TEMPO PERIOD OF LIFR AT RHI...AUW...AND CWA IN THE PRE-DAWN
HOURS AS WE WILL HAVE POOR CONDITIONS...LIGHT WINDS...AND PLENTY
OF LINGERING MOISTURE. LATER ISSUANCES WILL HAVE TO REFINE BASED
ON THE EVOLUTION OF THE POST-RAIN ENVIRONMENT. &&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE.........LUCHS
SYNOPSIS.......SKOWRONSKI
SHORT TERM.....SKOWRONSKI
LONG TERM......ECKBERG
AVIATION.......LUCHS
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1231 PM MDT FRI AUG 7 2015
.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 400 AM MDT FRI AUG 7 2015
THE MAIN CONCERN WITH THIS PORTION OF THE FORECAST IS THE POTENTIAL
FOR SEVERE CONVECTION THIS AFTERNOON/EVENING IN THE NEBRASKA PANHANDLE
AND THE POTENTIAL FOR RAIN AND THUNDERSTORMS ACROSS AREAS WEST OF
THE LARAMIE RANGE THIS EVENING.
TODAY AND TONIGHT:
LATEST WATER VAPOR LOOP WAS SHOWING A FAIRLY STRONG SHORTWAVE
MOVING THROUGH CENTRAL CALIFORNIA. AHEAD OF THIS FEATURE...THERE
IS A GOOD FETCH OF MOISTURE FROM THE PACIFIC WITH THE BULK OF THIS
MOISTURE STILL IN NEVADA AND UTAH. MEANWHILE...IN THE HIGH PLAINS
OF NORTHEAST COLORADO AND THE SOUTHERN PANHANDLE THE SURFACE
OBSERVATIONS ARE SHOWING QUITE A POOL OF LOW LEVEL MOISTURE WITH
DEWPOINTS IN THE 60S. SURFACE ANALYSIS IS ALREADY SHOWING THE LEE
TROUGH DEVELOPING IN RESPONSE TO THE SHORTWAVE IN CALIFORNIA.
PIECES OF ENERGY EJECTING AHEAD OF THIS SHORTWAVE COULD SET THE
STAGE FOR AN ACTIVE SEVERE WEATHER DAY ACROSS THE HIGH PLAINS OF
NEBRASKA AND PORTIONS OF SOUTHEAST WYOMING. THE MAIN QUESTION WILL
BE THE LOCATION OF THE BEST LOW LEVEL CONVERGENCE. THE HRRR IS
SHOWING THE INITIAL BOUNDARY SITUATED FROM KIMBALL TO ALLIANCE
NEBRASKA AROUND MID AFTERNOON. THEN THE PICTURE GETS MORE COMPLEX
AS THE AFTERNOON WEARS ON. THE NAM/HRRR SHOW ANOTHER FOCUS FOR
CONVERGENCE JUST EAST OF THE LARAMIE RANGE NEAR WHEATLAND AND
TORRINGTON. IF THIS SECONDARY AREA OF CONVERGENCE GETS
GOING....THE SEVERE WEATHER MAY SPREAD FURTHER NORTH AND WEST.
SHEAR IS QUITE STRONG FOR THIS TIME OF YEAR WITH 0-6KM VALUES OF
40 TO 50 KTS AND SURFACE BASED CAPES OF 2000 TO 3000J/KG. THESE
CONVERGENT BOUNDARIES COULD ALSO SERVE AS A FOCUS FOR TORNADOS
ESPECIALLY IF WE GET GOOD STRETCHING FROM THE STEEP LOW LEVEL
LAPSE RATES. AT THIS POINT...WE WOULD SAY THAT THE BEST SHOT FOR
SUPERCELLS PRODUCING LARGE HAIL...DAMAGING WINDS AND POSSIBLY
ISOLATED TORNADOS WOULD BE SOUTH OF A TORRINGTON TO ALLIANCE LINE
WITH THE RIGHT MOVERS GENERALLY MOVING EAST-SOUTHEAST. IF STORMS
GET GOING FURTHER NORTH THEY WILL GENERALLY LIFT NORTHEAST WITH
THE MAIN THREATS BEING GUSTY WINDS AND SMALL HAIL.
THIS EVENING:
ONGOING SEVERE WEATHER WILL BE POSSIBLE IN THE PANHANDLE. MEANWHILE...
THE MODELS ARE ADVERTISING A MID LEVEL SHORTWAVE MOVING THROUGH AREAS
WEST OF THE LARAMIE RANGE. THE DEEPER MOISTURE IS ALSO PROGGED TO
MOVE INTO THIS REGION DURING THAT TIME. NOT EXPECTING MUCH IN THE
WAY OF SEVERE WEATHER WITH THIS WAVE...BUT IT COULD BRING A GOOD
SHOT OF BENEFICIAL RAINFALL TO AREAS WEST OF THE LARAMIE RANGE
WHERE WILDFIRES HAVE BEEN PRESENT. THE RAIN SHOULD DIMINISH BY
MIDNIGHT OR SO AND MAY DISSIPATE AS IT CROSSES OVER THE LARAMIE
RANGE.
SATURDAY-SATURDAY NIGHT:
THE MAIN UPPER LEVEL WAVE IS PROGGED TO LIFT NORTHEAST TOWARDS
NORTHWEST WYOMING DURING THE MORNING AND THEN PUSH THROUGH NORTHERN
WYOMING AND SOUTHERN MONTANA DURING THE AFTERNOON AND EARLY EVENING.
THE TRACK OF THIS WAVE IS STILL A BIT UNCERTAIN...BUT IT IS VERY
DYNAMIC...SO WE DID INCREASE THE CHANCES OF PRECIP A BIT ACROSS
OUR NORTHERN COUNTIES SATURDAY AND SATURDAY EVENING. THIS AREA MAY
ALSO SEE A STRONG/SEVERE STORMS DUE TO GOOD SHEAR AND DECENT
INSTABILITY. NOT AS CONFIDENT ABOUT THE CONVECTION CHANCES CLOSER
TO I-80...BUT IF THERE IS ENOUGH MOISTURE PRESENT WE WOULD NOT BE
SURPRISED TO SEE A FEW STORMS DEVELOP OVER THE MOUNTAINS.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 400 AM MDT FRI AUG 7 2015
THE 00Z MEDIUM RANGE MODELS CONCUR THAT THE UPPER RIDGE WILL REBUILD
OVER THE ROCKY MOUNTAINS LATE SUNDAY AND EXTEND INTO THE GREAT PLAINS
THROUGH THE MIDDLE OF NEXT WEEK WHILE A UPPER LOW AND ASSOCIATED TROUGH
IMPACTS THE FAR WEST. NORMALLY THIS IS A STABLE PATTERN WITH WARM
TEMPERATURES ALOFT QUASHING DIURNAL CONVECTION. WHILE MOST OF THE
MONSOON MOISTURE WILL BE CHANNELED BETWEEN THE RIDGE AND TROUGH TO
THE WEST...THE ECMWF AND GFS INDICATE SOME MONSOON MOISTURE TRYING
TO INFILTRATE THE RIDGE. OROGRAPHIC LIFT AND THIS MOISTURE MAY RESULT
IN ISOLATED AFTERNOON TSTORM ACTIVITY OVER THE HIGHER TERRAIN OF
SOUTHEAST WY. OTHERWISE...MOST OF THE CWA WILL REMAIN DRY WITH
TEMPERATURES GRADUALLY WARMING EACH DAY. OTHER THAN THE TYPICAL
BREEZES EACH AFTERNOON...WINDS SHOULD NOT BE A PROBLEM FOR FIRE
WEATHER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1231 PM MDT FRI AUG 7 2015
MAIN AVIATION CONCERN FOR THIS TAF CYCLE WILL BE SHOWERS AND
THUNDERSTORMS EXPECTED TO DEVELOP THIS AFTERNOON AND CONTINUE AT
TIMES THRU SATURDAY. A SFC BOUNDARY HAS SET UP ROUGHLY FROM
CHEYENNE TO ALLIANCE...WITH SOUTHWEST WINDS IN A RATHER MOIST
ENVIRONMENT EAST OF THIS BOUNDARY. STILL EXPECT STORMS TO FIRE
ALONG THIS BOUNDARY AND TRAVEL NORTHEAST...WITH MVFR/IFR
CONDITIONS IN MODERATE TO HEAVY RAIN...STRONG WINDS...AND HAIL
POSSIBLE OUT OF A FEW STRONGER STORMS. ELSEWHERE...ISOLATED TO
SCATTERED SHOWERS AND STORMS ARE LIKELY AS WELL THROUGH TONIGHT
BUT SHOULD CARRY LESS IMPACT TO TERMINALS.
&&
.FIRE WEATHER...
ISSUED AT 400 AM MDT FRI AUG 7 2015
MONSOON MOISTURE WILL BE ON THE INCREASE TODAY IN RESPONSE TO AN UPPER
LEVEL DISTURBANCE MOVING NORTHEAST FROM THE DESERT SOUTHWEST. ALONG
WITH THE INCREASING MOISTURE...SHOWERS AND THUNDERSTORMS WILL BE A
GOOD POSSIBILITY ESPECIALLY IN THE NEBRASKA PANHANDLE THIS AFTERNOON
AND EVENING...AS WELL AS SOME BENEFICIAL RAINFALL MOVING INTO AREAS
WEST OF THE LARAMIE RANGE DURING THE EVENING. OVERALL...WIND SPEEDS
SHOULD ALSO BE LIGHTER TODAY...BUT THEY WILL BE GUSTY AND ERRATIC
NEAR THUNDERSTORMS.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...REC
LONG TERM...MAJ
AVIATION...RJM
FIRE WEATHER...REC