Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 06/21/14
AREA FORECAST DISCUSSION
NWS TUCSON AZ
240 PM MST THU JUN 19 2014
.SYNOPSIS...A FEW THUNDERSTORMS ARE POSSIBLE IN THE SOUTHEASTERN
CORNER OF THE STATE THROUGH THIS EVENING AND AGAIN ON FRIDAY.
OTHERWISE...DRY CONDITIONS AND A WARMING TREND WILL PREVAIL INTO
EARLY NEXT WEEK AS HIGH PRESSURE BUILDS OVER THE AREA.
&&
.DISCUSSION...THE CU FIELD NOT AS EXTENSIVE AS IT WAS WEDNESDAY.
RADAR/SATELLITE WAS SHOWING ISOLATED ACTIVITY SOUTH OF THE BORDER
ALONG SONORA/CHIHUAHUA STATE LINE...PRETTY MUCH WHERE THE HRRR MODEL
HAD BEEN INDICATING. THESE STORMS WERE FIRING ON BACK EDGE OF DEEPER
MOISTURE THAT WAS ON THE E QUAD OF A WEAK UPPER LEVEL CIRCULATION
THAT WAS NEAR HERMOSILLO. MAY SEE A FEW STORMS POP UP JUST SOUTH OF
COCHISE COUNTY INTO THIS EVENING. WILL ALSO HOLD ON TO VERY VERY
VERY SLIGHT CHANCE OF A DRY THUNDERSTORM OVER THE EASTERN MOUNTAINS.
WEAK TROFINESS OVER SONORA/BAJA WILL KEEP WEAK SOUTHERLY FLOW UP
INTO THE SERN SECTIONS. THUS WILL KEEP MENTION OF A SLIGHT CHANCE OF
DRY AFTERNOON THUNDERSTORMS E-SE OF TUCSON. SAME GOES FOR SUNDAY
ALTHOUGH HEIGHTS WILL BE ON THE INCREASE ALONG WITH WARMER MID-LEVEL
TEMPERATURES.
MOISTURE WILL NOT BE THAT FAR AWAY SUNDAY THROUGH NEXT WEEK BUT MAIN
STORY WILL BE THE MUCH WARMER TEMPERATURES WITH THE LOW DESERTS
RETURNING TO THE 105-109 RANGE. WILL JUST HAVE TO MAKE DAILY
ADJUSTMENTS TO AN INCREASE IN MOISTURE SONORA MEXICO THUNDERSTORM
OUTFLOWS.
&&
.AVIATION...VALID THRU 21/00Z.
SCT CUMULUS NEAR 120 KFT EASTERN HALF OF THE AREA WILL DISSIPATE
AFTER 20/03Z WITH CLEAR CONDITIONS AREAWIDE. SCT TO LOCALLY BROKEN
CUMULUS NEAR 100 KFT DEVELOPING AFTER 20/18Z EASTERN HALF OF THE
AREA WITH ISOLATED THUNDERSTORMS POSSIBLE EAST OF BENSON. SOUTHWEST
WIND 6-12 KTS WITH GUSTS TO 20 KTS BECOMING LIGHT AFT 20/03Z THEN
BECOMING WEST 7-12 KTS AFTER 20/19Z. AVIATION DISCUSSION NOT
UPDATED FOR TAF AMENDMENTS. CERNIGLIA
&&
.FIRE WEATHER...STILL A SLIGHT THREAT OF AN ISOLATED THUNDERSTORM
THIS EVENING EASTERN BORDER AREA OTHERWISE CLEARING TONIGHT. A BIT
OF EXTRA MOISTURE THIS AREA FRIDAY AND SATURDAY WILL SLIGHTLY
INCREASE THE CHANCE OF A FEW DRY THUNDERSTORMS EAST OF BENSON DURING
THE AFTERNOON AND EARLY EVENING HOURS BOTH DAYS. OTHERWISE...WEAKER
FLOW ALOFT INTO EARLY NEXT WEEK WILL ALLOW FOR LIGHTER WINDS THROUGH
THE PERIOD WITH THE EXCEPTION OF OCCASIONAL AFTERNOON GUSTS DUE TO
DAYTIME HEATING. TEMPERATURES RISING TO SLIGHTLY ABOVE NORMAL
FRIDAY ONWARD. CERNIGLIA
&&
.CLIMATE...IT HAS BEEN OVER THREE YEARS...JUNE 10-11 2011...SINCE
THE TUCSON AIRPORT RECORDED BACK-TO-BACK JUNE DAYS WITH HIGHS THAT
WERE IN THE 90S. AFTER A HIGH OF 99 WEDNESDAY THE FORECAST HIGH FOR
TODAY IS 99.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS NEW YORK NY
728 AM EDT THU JUN 19 2014
.SYNOPSIS...
A FRONTAL BOUNDARY WILL REMAIN NEARLY STATIONARY SOUTH OF LONG
ISLAND TODAY AND WILL BE PUSHED FURTHER SOUTH TONIGHT THROUGH
FRIDAY AS CANADIAN HIGH PRESSURE BUILDS FROM THE NORTH. HIGH
PRESSURE REMAINS INTO THE WEEKEND AS A SERIES OF WEAK
DISTURBANCES MOVE JUST SOUTH OF THE REGION. A SLOW MOVING FRONTAL
SYSTEM IMPACTS THE AREA DURING THE MIDDLE PART OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MID LEVEL SHORTWAVE OVER THE OHIO VALLEY WILL ADVANCE TOWARDS THE
AREA...PASSING THROUGH LATE THIS MORNING. A FRONTAL BOUNDARY SOUTH
OF LONG ISLAND WILL REMAIN NEARLY STATIONARY TODAY AS A WEAK WAVE
OF LOW PRES ASSOCIATED WITH THE UPPER TROUGH TRACKS ALONG IT. THIS
WILL LEAD TO A WET START TO THE DAY WITH SHOWERS ACROSS THE CWA.
HAVE UPDATED POPS TO BETTER ALIGN WITH CURRENT RADAR
IMAGERY/TRENDS. EARLIER RUNS OF THE HRRR HAD A DECENT HANDLE ON
CURRENT RADAR TRENDS...KEEPING NYC/LI MOSTLY DRY...BUT HAS SINCE
LOST ITS WAY. HOWEVER IT DOES HINT AT A BREAK IN THE ACTION FOR A
FEW HOURS THIS MORNING...BEFORE THE SECOND ROUND OVER WESTERN PA
MOVES IN. NEW POPS REFLECT THIS THINKING. OTHERWISE...JUST SOME
MINOR ADJUSTMENTS TO HOURLY T/TD/WINDS AND SKY BASED ON LATEST OBS
AND TRENDS.
SHOWERS WILL COME TO AN END WITH SKIES CLEARING FROM N TO S
DURING THE AFTERNOON AS THE FRONT BEGINS TO BE NUDGED SOUTHWARD BY
HIGH PRES NOSING IN TO THE NE FROM HUDSON BAY. SHOULD SEE A DECENT
AMOUNT OF SUNSHINE DURING THE PEAK HEATING HOURS. BUFKIT SOUNDINGS
INDICATE MIXING ONLY TO AROUND H95 WHICH SHOULD YIELD HIGHS IN THE
MID TO UPPER 70S ACROSS MOST OF THE FORECAST AREA DUE TO A W/NW
FLOW. METRO NY/NJ WILL BE A FEW DEGREES WARMER...AROUND 80.
STRONGER FLOW ALOFT SHOULD KEEP SEABREEZES AT BAY FOR THE MOST
PART. SE CT AND SOUTHERN BROOKLYN/QUEENS ARE THE TWO AREAS THAT
HAVE THE HIGHEST CHANCE TO BREEZE LATER THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
BENIGN WEATHER THEN PREVAILS THROUGH FRIDAY WITH CANADIAN HIGH
PRES IN CONTROL. LIGHT WINDS AND MOSTLY CLEAR SKIES TONIGHT WILL
RESULT IN GOOD RADIATIONAL COOLING CONDITIONS. 50S WITH A FEW
ISOLD UPPER 40 DEGREE TEMPS ARE EXPECTED IN RURAL LOCATIONS...AND
LOW TO MID 60S IN THE URBAN AND SUBURBAN COUNTIES OF NYC.
ABUNDANT SUNSHINE AND NOTICEABLY LESS HUMID CONDITIONS ARE THEN
EXPECTED FOR FRI. MIXING HEIGHTS WILL BE HIGHER...TO AROUND
H85...WHICH WILL RESULT IN SLIGHTLY HIGHER TEMPERATURES DURING THE
DAYTIME. A W/NW FLOW WILL ONCE AGAIN CAUSE HIGHS OF UPPER 70S TO
LOWER 80S ACROSS THE AREA.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
HIGH PRESSURE REMAINS IN CONTROL THROUGH MUCH OF THE LONG TERM
PERIOD WITH A COLD FRONT SITTING TO OUR SOUTH.
DRY CONDITIONS EXPECTED THROUGH THE WEEKEND WITH LIGHT WINDS AS THE
HIGH IS OVERHEAD THE AREA. ECMWF CONTINUES TO HINT AT A FEW SHOWERS
ON SATURDAY BUT WITH THE ATMOSPHERE RELATIVELY DRY...WILL CONTINUE
THE DRY FORECAST. PARTLY CLOUDY SKIES WILL PREVAIL MOSTLY DUE TO
CIRRUS ASSOCIATED WITH THE LOW TO THE SOUTH FOR SAT AND SUN.
FEWER CLOUDS EXPECTED MONDAY WITH BROAD HIGH PRESSURE REMAINING IN
CONTROL WITH A DRY FORECAST. A SLOW MOVING FRONTAL SYSTEM WILL BE
APPROACHING FROM THE WEST ON TUESDAY WITH CLOUDS INCREASING THROUGH
THE AFTERNOON. SLIGHT CHANCE POPS ARE INTRODUCED BY TUESDAY
AFTERNOON ALTHOUGH GLOBAL MODELS CONTINUE TO SLOW THIS SYSTEM DOWN.
THERE IS A CHANCE TUESDAY COULD REMAIN DRY. CHANCE POPS REMAIN FOR
TUESDAY NIGHT INTO WEDNESDAY AS THE COLD FRONT PASSES THROUGH.
MUCH COOLER TEMPS BUILD IN STARTING ON SATURDAY THANKS TO LOWERING
HEIGHTS AND HIGH PRESSURE BUILDING FROM THE NORTH. NEAR NORMAL AND
SIMILAR TEMPS SATURDAY THROUGH WEDNESDAY...UPPER 70S TO LOWER 80S
FOR HIGHS AND LOWER TO MIDDLE 60S FOR LOWS. GOOD MODEL AGREEMENT
WITH THESE VALUES.
&&
.AVIATION /11Z THURSDAY THROUGH MONDAY/...
WEAK WAVES OF LOW PRESSURE PASS JUST TO THE SOUTH OF LONG ISLAND
INTO THIS AFTERNOON...THEN HIGH PRESSURE BUILDS OVER THE AREA
TONIGHT.
PRIMARILY VFR THROUGH THE TAF PERIOD. RAIN 12-14Z WILL IMPACT
MAINLY NORTHERN TERMINALS...THEN 14-18Z MAINLY SOUTHERN TERMINALS.
COULD GET A BRIEF PERIOD OF MVFR IN ANY EMBEDDED CONVECTION.
CURRENTLY ASSESS PROBABILITY OF THUNDER AT ANY GIVEN TERMINAL
TODAY AT 20 PERCENT OR LESS...SO HAVE LEFT OUT OF TAFS.
WINDS LESS THAN 10 KT THROUGH THE TAF PERIOD. LIGHT AND VARIABLE
WINDS GIVE WAY TO NE FLOW THIS MORNING. WINDS BACK TO THE N-NW BY
AFTERNOON...EXCEPT AT KGON WHERE SEABREEZE SHOULD MAKE MORE W.
COULD ALSO SEE SEABREEZE AT KJFK LATE THIS AFTERNOON/EARLY THIS
EVENING. WINDS BECOME LIGHT AND VARIABLE AGAIN THIS EVENING.
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 END OF LIGHT AND VARIABLE WINDS AND
CHANGES IN WIND DIRECTION AND SPEED COULD BE OFF +/- 2-3 HOURS.
START/END TIME OF SHRA COULD BE OFF +/- 1-2 HOURS. HIGH CONFIDENCE
IN WINDS LESS THAN 10 KT OUTSIDE OF CONVECTION.
KLGA FCSTER COMMENTS: TIMING CHANGES IN WIND DIRECTION AND SPEED
COULD BE OFF +/- 2-3 HOURS. START/END TIME OF SHRA COULD BE OFF
+/- 1-2 HOURS. HIGH CONFIDENCE IN WINDS LESS THAN 10 KT OUTSIDE OF
CONVECTION.
KEWR FCSTER COMMENTS: TIMING CHANGES IN WIND DIRECTION AND SPEED
COULD BE OFF +/- 2-3 HOURS. START/END TIME OF SHRA COULD BE OFF
+/- 1-2 HOURS. HIGH CONFIDENCE IN WINDS LESS THAN 10 KT OUTSIDE OF
CONVECTION.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: TIMING END OF LIGHT AND VARIABLE WINDS AND
CHANGES IN WIND DIRECTION AND SPEED COULD BE OFF +/- 2-3 HOURS.
START/END TIME OF SHRA COULD BE OFF +/- 1-2 HOURS. HIGH CONFIDENCE
IN WINDS LESS THAN 10 KT OUTSIDE OF CONVECTION.
KHPN FCSTER COMMENTS: TIMING OF CHANGES IN WIND DIRECTION AND
SPEED COULD BE OFF +/- 2-3 HOURS. END TIME OF SHRA COULD BE OFF
+/- 1-2 HOURS. HIGH CONFIDENCE IN WINDS LESS THAN 10 KT OUTSIDE OF
CONVECTION.
KISP FCSTER COMMENTS: TIMING END OF LIGHT AND VARIABLE WINDS AND
CHANGES IN WIND DIRECTION AND SPEED COULD BE OFF +/- 2-3 HOURS.
START/END TIME OF SHRA COULD BE OFF +/- 1-2 HOURS. HIGH CONFIDENCE
IN WINDS LESS THAN 10 KT OUTSIDE OF CONVECTION.
.OUTLOOK FOR 12Z FRIDAY THROUGH MONDAY...
.LATE FRIDAY-MONDAY...VFR.
&&
.MARINE...
SUB-ADVISORY CONDITIONS ARE EXPECTED THROUGH MON WITH A WEAK PRES
GRADIENT ACROSS THE WATERS. GUSTS WILL REMAIN BELOW 20 KT...WITH
SEAS AROUND 2-3 FT ON THE OCEAN.
&&
.HYDROLOGY...
BASIN AVERAGE QPF IS EXPECTED TO RANGE BETWEEN 1/10 TO 1/4 OF AN
INCH TODAY. NO HYDROLOGIC IMPACTS ARE EXPECTED.
NO RAINFALL IS THEN EXPECTED INTO EARLY NEXT WEEK.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...24/LN
NEAR TERM...24
SHORT TERM...24
LONG TERM...LN
AVIATION...MALOIT
MARINE...24/LN
HYDROLOGY...24/LN
AREA FORECAST DISCUSSION
NWS NEW YORK NY
548 AM EDT THU JUN 19 2014
.SYNOPSIS...
A FRONTAL BOUNDARY WILL REMAIN NEARLY STATIONARY SOUTH OF LONG
ISLAND TODAY AND WILL BE PUSHED FURTHER SOUTH TONIGHT THROUGH
FRIDAY AS CANADIAN HIGH PRESSURE BUILDS FROM THE NORTH. HIGH
PRESSURE REMAINS INTO THE WEEKEND AS A SERIES OF WEAK DISTURBANCES
MOVE JUST SOUTH OF THE REGION. A SLOW MOVING FRONTAL SYSTEM
IMPACTS THE AREA DURING THE MIDDLE PART OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MID LEVEL SHORTWAVE OVER THE OHIO VALLEY WILL ADVANCE TOWARDS THE
AREA...PASSING THROUGH LATE THIS MORNING. A FRONTAL BOUNDARY SOUTH
OF LONG ISLAND WILL REMAIN NEARLY STATIONARY TODAY AS A WEAK WAVE
OF LOW PRES ASSOCIATED WITH THE UPPER TROUGH TRACKS ALONG IT. THIS
WILL LEAD TO A WET START TO THE DAY WITH SHOWERS ACROSS THE CWA.
HAVE UPDATED POPS TO BETTER ALIGN WITH CURRENT RADAR
IMAGERY/TRENDS. EARLIER RUNS OF THE HRRR HAD A DECENT HANDLE ON
CURRENT RADAR TRENDS...KEEPING NYC/LI MOSTLY DRY...BUT HAS SINCE LOST
ITS WAY. HOWEVER IT DOES HINT AT A BREAK IN THE ACTION FOR A FEW
HOURS THIS MORNING...BEFORE THE SECOND ROUND OVER WESTERN PA MOVES
IN. NEW POPS REFLECT THIS THINKING. OTHERWISE...JUST SOME MINOR
ADJUSTMENTS TO HOURLY T/TD/WINDS AND SKY BASED ON LATEST OBS AND TRENDS.
SHOWERS WILL COME TO AN END WITH SKIES CLEARING FROM N TO S DURING THE
AFTN AS THE FRONT BEGINS TO BE NUDGED SWD BY HIGH PRES NOSING IN
TO THE NE FROM HUDSON BAY. SHOULD SEE A DECENT AMOUNT OF SUNSHINE
DURING THE PEAK HEATING HOURS. BUFKIT SOUNDINGS INDICATE MIXING
ONLY TO AROUND H95 WHICH SHOULD YIELD HIGHS IN THE MID TO UPPER
70S ACROSS MOST OF THE FORECAST AREA DUE TO A W/NW FLOW. METRO
NY/NJ WILL BE A FEW DEGREES WARMER...AROUND 80.
STRONGER FLOW ALOFT SHOULD KEEP SEABREEZES AT BAY FOR THE MOST
PART. SE CT AND SOUTHERN BROOKLYN/QUEENS ARE THE TWO AREAS THAT
HAVE THE HIGHEST CHC TO BREEZE LATER THIS AFTN.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
BENIGN WEATHER THEN PREVAILS THROUGH FRIDAY WITH CANADIAN HIGH
PRES IN CONTROL. LIGHT WINDS AND MOSTLY CLEAR SKIES TONIGHT WILL RESULT
IN GOOD RADIATIONAL COOLING CONDITIONS. 50S WITH A FEW ISOLD UPPER
40 DEGREE TEMPS ARE EXPECTED IN RURAL LOCATIONS...AND LOW TO MID
60S IN THE URBAN AND SUBURBAN COUNTIES OF NYC.
ABUNDANT SUNSHINE AND NOTICEABLY LESS HUMID CONDITIONS ARE THEN EXPECTED
FOR FRI. MIXING HEIGHTS WILL BE HIGHER...TO AROUND H85...WHICH
WILL RESULT IN SLIGHTLY HIGHER TEMPERATURES DURING THE DAYTIME. A
W/NW FLOW WILL ONCE AGAIN CAUSE HIGHS OF UPPER 70S TO LOWER 80S
ACROSS THE AREA.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
HIGH PRESSURE REMAINS IN CONTROL THROUGH MUCH OF THE LONG TERM
PERIOD WITH A COLD FRONT SITTING TO OUR SOUTH.
DRY CONDITIONS EXPECTED THROUGH THE WEEKEND WITH LIGHT WINDS AS THE
HIGH IS OVERHEAD THE AREA. ECMWF CONTINUES TO HINT AT A FEW SHOWERS
ON SATURDAY BUT WITH THE ATMOSPHERE RELATIVELY DRY...WILL CONTINUE
THE DRY FORECAST. PARTLY CLOUDY SKIES WILL PREVAIL MOSTLY DUE TO
CIRRUS ASSOCIATED WITH THE LOW TO THE SOUTH FOR SAT AND SUN.
FEWER CLOUDS EXPECTED MONDAY WITH BROAD HIGH PRESSURE REMAINING IN
CONTROL WITH A DRY FORECAST. A SLOW MOVING FRONTAL SYSTEM WILL BE
APPROACHING FROM THE WEST ON TUESDAY WITH CLOUDS INCREASING THROUGH
THE AFTERNOON. SLIGHT CHANCE POPS ARE INTRODUCED BY TUESDAY
AFTERNOON ALTHOUGH GLOBAL MODELS CONTINUE TO SLOW THIS SYSTEM DOWN.
THERE IS A CHANCE TUESDAY COULD REMAIN DRY. CHANCE POPS REMAIN FOR
TUESDAY NIGHT INTO WEDNESDAY AS THE COLD FRONT PASSES THROUGH.
MUCH COOLER TEMPS BUILD IN STARTING ON SATURDAY THANKS TO LOWERING
HEIGHTS AND HIGH PRESSURE BUILDING FROM THE NORTH. NEAR NORMAL AND
SIMILAR TEMPS SATURDAY THROUGH WEDNESDAY...UPPER 70S TO LOWER 80S
FOR HIGHS AND LOWER TO MIDDLE 60S FOR LOWS. GOOD MODEL AGREEMENT
WITH THESE VALUES.
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
WEAK WAVES OF LOW PRESSURE PASS JUST TO THE SOUTH OF LONG ISLAND
INTO THIS AFTERNOON...THEN HIGH PRESSURE BEGINS TO BUILD OVER THE
AREA INTO TONIGHT.
VFR THROUGH MOST OF THE TAF PERIOD. SHOULD SEE CEILINGS AROUND
5000 FT THIS MORNING. WILL SEE PASSING SHRA EARLY THIS
MORNING...SO ONLY A TEMPO...THEN A MORE PROLONGED PERIOD OF SHRA
FROM MID MORNING INTO EARLY AFTERNOON. COULD SEE SOME MVFR
VISIBILITIES WITH STRONGER SHRA THIS MORNING/EARLY THIS AFTERNOON.
EVEN SMALLER CHANCE OF MVFR CEILINGS...SO HAVE KEPT THEM ABOVE
3000 FT FOR NOW. SKC BY LATE AFTERNOON/EARLY EVENING.
CURRENTLY ASSESS PROBABILITY OF THUNDER AT ANY GIVEN TERMINAL
TODAY AT 20 PERCENT OR LESS...SO HAVE LEFT OUT OF TAFS.
LIGHT AND VARIABLE WINDS GIVE WAY TO NE FLOW LESS THAN 10 KT THIS
MORNING. WINDS BACK TO THE N-NW BY AFTERNOON...EXCEPT AT KGON WHERE
SEABREEZE SHOULD MAKE MORE WSW. COULD ALSO SEE SEABREEZE AT KJFK
LATE THIS AFTERNOON/EARLY THIS EVENING. WINDS BECOME LIGHT AND
VARIABLE AGAIN THIS EVENING.
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 END OF LIGHT AND VARIABLE WINDS AND
CHANGES IN WIND DIRECTION AND SPEED COULD BE OFF +/- 2-3 HOURS.
START/END TIME OF SHRA COULD BE OFF +/- 1-2 HOURS. HIGH CONFIDENCE
IN WINDS LESS THAN 10 KT OUTSIDE OF CONVECTION.
KLGA FCSTER COMMENTS: TIMING END OF LIGHT AND VARIABLE WINDS AND
CHANGES IN WIND DIRECTION AND SPEED COULD BE OFF +/- 2-3 HOURS.
START/END TIME OF SHRA COULD BE OFF +/- 1-2 HOURS. HIGH CONFIDENCE
IN WINDS LESS THAN 10 KT OUTSIDE OF CONVECTION.
KEWR FCSTER COMMENTS: TIMING END OF LIGHT AND VARIABLE WINDS AND
CHANGES IN WIND DIRECTION AND SPEED COULD BE OFF +/- 2-3 HOURS.
START/END TIME OF SHRA COULD BE OFF +/- 1-2 HOURS. HIGH CONFIDENCE
IN WINDS LESS THAN 10 KT OUTSIDE OF CONVECTION.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: TIMING END OF LIGHT AND VARIABLE WINDS AND
CHANGES IN WIND DIRECTION AND SPEED COULD BE OFF +/- 2-3 HOURS.
START/END TIME OF SHRA COULD BE OFF +/- 1-2 HOURS. HIGH CONFIDENCE
IN WINDS LESS THAN 10 KT OUTSIDE OF CONVECTION.
KHPN FCSTER COMMENTS: TIMING END OF LIGHT AND VARIABLE WINDS AND
CHANGES IN WIND DIRECTION AND SPEED COULD BE OFF +/- 2-3 HOURS.
START/END TIME OF SHRA COULD BE OFF +/- 1-2 HOURS. HIGH CONFIDENCE
IN WINDS LESS THAN 10 KT OUTSIDE OF CONVECTION.
KISP FCSTER COMMENTS: TIMING END OF LIGHT AND VARIABLE WINDS AND
CHANGES IN WIND DIRECTION AND SPEED COULD BE OFF +/- 2-3 HOURS.
START/END TIME OF SHRA COULD BE OFF +/- 1-2 HOURS. HIGH CONFIDENCE
IN WINDS LESS THAN 10 KT OUTSIDE OF CONVECTION.
.OUTLOOK FOR 06Z FRIDAY THROUGH MONDAY...
.LATE THURSDAY NIGHT-MONDAY...VFR.
&&
.MARINE...
SUB-ADVISORY CONDITIONS ARE EXPECTED THROUGH MON WITH A WEAK PRES
GRADIENT ACROSS THE WATERS. GUSTS WILL REMAIN BELOW 20 KT...WITH
SEAS AROUND 2-3 FT ON THE OCEAN.
&&
.HYDROLOGY...
BASIN AVERAGE QPF IS EXPECTED TO RANGE BETWEEN 1/10 TO 1/4 OF AN
INCH TODAY. NO HYDROLOGIC IMPACTS ARE EXPECTED.
NO RAINFALL IS THEN EXPECTED INTO EARLY NEXT WEEK.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...24/LN
NEAR TERM...24
SHORT TERM...24
LONG TERM...LN
AVIATION...MALOIT
MARINE...24/LN
HYDROLOGY...24/LN
AREA FORECAST DISCUSSION
NWS NEW YORK NY
155 AM EDT THU JUN 19 2014
.SYNOPSIS...
A FRONTAL BOUNDARY WILL REMAIN NEARLY STATIONARY ACROSS
SOUTHEASTERN PENNSYLVANIA INTO SOUTHERN NEW JERSEY TONIGHT INTO
THURSDAY MORNING. THE FRONT THEN CONTINUES SOUTHWARD AS CANADIAN
HIGH PRESSURE BUILDS FROM THE NORTH THROUGH FRIDAY NIGHT. THE HIGH
REMAINS INTO THE WEEKEND AS A SERIES OF WEAK DISTURBANCES MOVE
JUST SOUTH OF THE REGION. A SLOW MOVING FRONTAL SYSTEM IMPACTS THE
AREA DURING THE FIRST PART OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
A COLD FRONT REMAINS NEARLY STATIONARY SOUTH OF LONG ISLAND
OVERNIGHT. CONVECTION IN THE DEEP W/NW FLOW ACROSS CENTRAL PA AND
THE OHIO VALLEY WILL MOVE INTO THE AREA OVERNIGHT. HAVE ADJUSTED
POPS TO FIT WITH TIMING OF THESE SHOWERS. THEY ARE EXPECTED TO
MAKE IT TO NYC AROUND 8Z...ALTHOUGH HRRR IS INDICATING THAT THE
MAJORITY OF THE ACTIVITY WILL TRACK NORTH AND SOUTH OF THE FIVE
BOROUGHS. MUCAPE NOSEDIVES AT THE PA/NJ BORDER AND IS BELOW 100
J/KG ONCE YOU GET TO NE NJ WITH CIN. TSTMS SHOULD DISSIPATE BEFORE
MAKING IT INTO THE CWA WITH JUST LIGHT TO MODERATE SHOWERS THROUGH
6AM.
LOW TEMPERATURES WERE A BLEND OF NAM12 AND MAV GUIDANCE WITH SOME
ADJUSTMENTS UP TO ACCOUNT FOR RECENT TRENDS...ESPECIALLY WITH
URBAN HEAT ISLAND EFFECT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM FRIDAY/...
A FRONTAL BOUNDARY WILL REMAIN NEARLY STATIONARY JUST SOUTH OF THE
REGION...FROM SOUTHEASTERN PENNSYLVANIA TO SOUTHERN NEW
JERSEY...INTO MIDDAY THURSDAY...THEN SINK SOUTH AS A COLD FRONT
THURSDAY AFTERNOON AND EVENING AS HIGH PRESSURE BUILDS FROM THE
NORTH.
MODELS IN GOOD AGREEMENT THURSDAY MORNING WITH CONVEYING QPF
ACROSS MOST OF THE REGION...SO HAVE INCREASED POPS TO LIKELY IN
THE MORNING AS A FAIRLY STRONG MID AND UPPER WAVE MOVE ALONG THE
FRONTAL BOUNDARY. A STABLE AIR MASS WILL BE ACROSS THE ENTIRE
FORECAST AREA WITH SURFACE BASED LI PLUS 2 TO PLUS 5 AND LITTLE TO
NO ELEVATED CAPE AVAILABLE TO SUPPORT THUNDER. THIS CORRESPONDS
WELL WITH THE STORM PREDICTION OUTLOOK FOR THURSDAY...KEEPING
THUNDER CHANCES INTO SOUTHERN NEW JERSEY.
SOME STRONGER STEERING FLOW FROM THE PIVOTING SHORTWAVE IN
EASTERN QUEBEC AND SOUTHWARD PUSHING UPPER LEVEL JET WILL HELP
MOVE THE FRONT BACK SOUTH OF THE REGION. MAX TEMPERATURES THURSDAY
WILL BE REMARKABLY COOLER...UPPER 70S TO LOWER 80S WITH THE
ABUNDANT CLOUDS AND PRECIP EARLY. THESE WERE A BLEND OF
GMOS...MET...AND MAV.
WEATHER EVENTUALLY DRIES OUT WITH SOME CLEARING LATER IN THE DAY
FROM NORTH TO SOUTH AS HIGH PRESSURE BUILDS SOUTHEAST FROM THE
HUDSON BAY. A MORE NORTHEASTERLY FLOW THURSDAY NIGHT WILL ALLOW
FOR A REMARKABLY DRIER AIRMASS TO ENCOMPASS THE REGION. DEWPOINTS
ARE FORECAST TO DROP INTO THE UPPER 40S TO LOWER 50S BY FRIDAY
MORNING. LOWS THURSDAY NIGHT WERE A BLEND OF MET AND MAV GUIDANCE
AND WILL BE GENERALLY AROUND 10 DEGREES COOLER THAN THE PREVIOUS
NIGHT FOR MOST LOCATIONS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
THE LONG TERM PERIOD STARTS OFF WITH WEAK HIGH PRESSURE OVER THE
REGION. EXPECT DRY CONDITIONS ON FRIDAY WITH HIGHS IN THE UPPER 70S
AND LOWER 80S.
CLOUDS INCREASE ON SATURDAY AS A LOW PRESSURE AREA DEVELOPS ALONG A
FRONTAL BOUNDARY SOUTH OF THE REGION. MOST OF THE LATEST GUIDANCE
CONTINUES TO KEEP THE PRECIPITATION SOUTH OF THE REGION...SO WILL
CONTINUE WITH A DRY FORECAST. WEAK HIGH PRESSURE RETURNS ON SUNDAY
AND MONDAY.
UNSETTLED CONDITIONS RETURN MONDAY NIGHT AND TUESDAY AS SLOW MOVING
SHORTWAVES WILL PRECEDE A FRONTAL SYSTEM. WILL CONTINUE TO CARRY
CHANCE POPS THROUGH THIS PERIOD.
SOME LEFTOVER SHOWERS WILL BE POSSIBLE INTO WEDNESDAY.
EXPECT NEAR NORMAL TEMPERATURES THROUGH THE LONG TERM.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
WEAK WAVES OF LOW PRESSURE PASS JUST TO THE SOUTH OF LONG ISLAND
INTO THIS AFTERNOON...THEN HIGH PRESSURE BEGINS TO BUILD OVER THE
AREA INTO TONIGHT.
VFR THROUGH MOST OF THE TAF PERIOD. SHOULD SEE CEILINGS AROUND
5000 FT THIS MORNING. WILL SEE PASSING SHRA EARLY THIS
MORNING...SO ONLY A TEMPO...THEN A MORE PROLONGED PERIOD OF SHRA
FROM MID MORNING INTO EARLY AFTERNOON. COULD SEE SOME MVFR
VISIBILITIES WITH STRONGER SHRA THIS MORNING/EARLY THIS AFTERNOON.
EVEN SMALLER CHANCE OF MVFR CEILINGS...SO HAVE KEPT THEM ABOVE
3000 FT FOR NOW. SKC BY LATE AFTERNOON/EARLY EVENING.
CURRENTLY ASSESS PROBABILITY OF THUNDER AT ANY GIVEN TERMINAL
TODAY AT 20 PERCENT OR LESS...SO HAVE LEFT OUT OF TAFS.
LIGHT AND VARIABLE WINDS GIVE WAY TO NE FLOW LESS THAN 10 KT THIS
MORNING. WINDS BACK TO THE NW BY AFTERNOON...EXCEPT AT KGON WHERE
SEABREEZE SHOULD MAKE MORE WSW. COULD ALSO SEE SEABREEZE AT KJFK
LATE THIS AFTERNOON/EARLY THIS EVENING. WINDS BECOME LIGHT AND
VARIABLE AGAIN THIS EVENING.
.OUTLOOK FOR 06Z FRIDAY THROUGH MONDAY...
.LATE THURSDAY NIGHT-MONDAY...VFR.
&&
.MARINE...
NO CHANGES AT THIS TIME.
A WEST FLOW BECOMING NORTHWEST LATE THIS EVENING AND OVERNIGHT
WILL KEEP SEAS ON THE OCEAN WATERS AT 3 FT OR LESS.
TRANQUIL CONDITIONS ARE EXPECTED TO CONTINUES ACROSS THE WATERS
THROUGH THURSDAY NIGHT WITH WIND SPEEDS LESS THAN 15 KT AND OCEAN
SEAS OF 3 FT OR LESS. THIS IS EXPECTED AS A RESULT OF A WEAK
PRESSURE GRADIENT.
A WEAK PRESSURE GRADIENT OVER THE AREA WATERS WILL KEEP
CONDITIONS BELOW SMALL CRAFT LEVELS FRIDAY THROUGH MONDAY. SEAS
WILL REMAIN AROUND 2-3 FT WITH GUSTS BELOW 20KT.
&&
.HYDROLOGY...
BASIN AVERAGE QPF THROUGH THU MORNING IS EXPECTED TO RANGE BETWEEN
1/10 TO 1/3 OF AN INCH. NO HYDROLOGIC IMPACTS ARE EXPECTED.
NO WIDESPREAD SIGNIFICANT RAINFALL IS EXPECTED INTO THE UPCOMING
WEEKEND.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...24/JM/BC
NEAR TERM...24/JM
SHORT TERM...JM
LONG TERM...BC
AVIATION...MALOIT
MARINE...24/JM/BC
HYDROLOGY...JM/BC
AREA FORECAST DISCUSSION
NWS NEW YORK NY
110 AM EDT THU JUN 19 2014
.SYNOPSIS...
A FRONTAL BOUNDARY WILL REMAIN NEARLY STATIONARY ACROSS
SOUTHEASTERN PENNSYLVANIA INTO SOUTHERN NEW JERSEY TONIGHT INTO
THURSDAY MORNING. THE FRONT THEN CONTINUES SOUTHWARD AS CANADIAN
HIGH PRESSURE BUILDS FROM THE NORTH. THE HIGH REMAINS INTO THE
WEEKEND AS A SERIES OF WEAK DISTURBANCES MOVE JUST SOUTH OF THE
REGION. A SLOW MOVING FRONTAL SYSTEM IMPACTS THE AREA DURING THE
FIRST PART OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
A COLD FRONT REMAINS NEARLY STATIONARY SOUTH OF LONG ISLAND
OVERNIGHT. CONVECTION IN THE DEEP W/NW FLOW ACROSS CENTRAL PA AND
THE OHIO VALLEY WILL MOVE INTO THE AREA OVERNIGHT. HAVE ADJUSTED
POPS TO FIT WITH TIMING OF THESE SHOWERS. THEY ARE EXPECTED TO
MAKE IT TO NYC AROUND 8Z...ALTHOUGH HRRR IS INDICATING THAT THE
MAJORITY OF THE ACTIVITY WILL TRACK NORTH AND SOUTH OF THE FIVE
BOROUGHS. MUCAPE NOSEDIVES AT THE PA/NJ BORDER AND IS BELOW 100
J/KG ONCE YOU GET TO NE NJ WITH CIN. TSTMS SHOULD DISSIPATE BEFORE
MAKING IT INTO THE CWA WITH JUST LIGHT TO MODERATE SHOWERS THROUGH
6AM.
LOW TEMPERATURES WERE A BLEND OF NAM12 AND MAV GUIDANCE WITH SOME
ADJUSTMENTS UP TO ACCOUNT FOR RECENT TRENDS...ESPECIALLY WITH
URBAN HEAT ISLAND EFFECT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM FRIDAY/...
A FRONTAL BOUNDARY WILL REMAIN NEARLY STATIONARY JUST SOUTH OF THE
REGION...FROM SOUTHEASTERN PENNSYLVANIA TO SOUTHERN NEW
JERSEY...INTO MIDDAY THURSDAY...THEN SINK SOUTH AS A COLD FRONT
THURSDAY AFTERNOON AND EVENING AS HIGH PRESSURE BUILDS FROM THE
NORTH.
MODELS IN GOOD AGREEMENT THURSDAY MORNING WITH CONVEYING QPF
ACROSS MOST OF THE REGION...SO HAVE INCREASED POPS TO LIKELY IN
THE MORNING AS A FAIRLY STRONG MID AND UPPER WAVE MOVE ALONG THE
FRONTAL BOUNDARY. A STABLE AIR MASS WILL BE ACROSS THE ENTIRE
FORECAST AREA WITH SURFACE BASED LI PLUS 2 TO PLUS 5 AND LITTLE TO
NO ELEVATED CAPE AVAILABLE TO SUPPORT THUNDER. THIS CORRESPONDS
WELL WITH THE STORM PREDICTION OUTLOOK FOR THURSDAY...KEEPING
THUNDER CHANCES INTO SOUTHERN NEW JERSEY.
SOME STRONGER STEERING FLOW FROM THE PIVOTING SHORTWAVE IN
EASTERN QUEBEC AND SOUTHWARD PUSHING UPPER LEVEL JET WILL HELP
MOVE THE FRONT BACK SOUTH OF THE REGION. MAX TEMPERATURES THURSDAY
WILL BE REMARKABLY COOLER...UPPER 70S TO LOWER 80S WITH THE
ABUNDANT CLOUDS AND PRECIP EARLY. THESE WERE A BLEND OF
GMOS...MET...AND MAV.
WEATHER EVENTUALLY DRIES OUT WITH SOME CLEARING LATER IN THE DAY
FROM NORTH TO SOUTH AS HIGH PRESSURE BUILDS SOUTHEAST FROM THE
HUDSON BAY. A MORE NORTHEASTERLY FLOW THURSDAY NIGHT WILL ALLOW
FOR A REMARKABLY DRIER AIRMASS TO ENCOMPASS THE REGION. DEWPOINTS
ARE FORECAST TO DROP INTO THE UPPER 40S TO LOWER 50S BY FRIDAY
MORNING. LOWS THURSDAY NIGHT WERE A BLEND OF MET AND MAV GUIDANCE
AND WILL BE GENERALLY AROUND 10 DEGREES COOLER THAN THE PREVIOUS
NIGHT FOR MOST LOCATIONS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
THE LONG TERM PERIOD STARTS OFF WITH WEAK HIGH PRESSURE OVER THE
REGION. EXPECT DRY CONDITIONS ON FRIDAY WITH HIGHS IN THE UPPER 70S
AND LOWER 80S.
CLOUDS INCREASE ON SATURDAY AS A LOW PRESSURE AREA DEVELOPS ALONG A
FRONTAL BOUNDARY SOUTH OF THE REGION. MOST OF THE LATEST GUIDANCE
CONTINUES TO KEEP THE PRECIPITATION SOUTH OF THE REGION...SO WILL
CONTINUE WITH A DRY FORECAST. WEAK HIGH PRESSURE RETURNS ON SUNDAY
AND MONDAY.
UNSETTLED CONDITIONS RETURN MONDAY NIGHT AND TUESDAY AS SLOW MOVING
SHORTWAVES WILL PRECEDE A FRONTAL SYSTEM. WILL CONTINUE TO CARRY
CHANCE POPS THROUGH THIS PERIOD.
SOME LEFTOVER SHOWERS WILL BE POSSIBLE INTO WEDNESDAY.
EXPECT NEAR NORMAL TEMPERATURES THROUGH THE LONG TERM.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
COLD FRONT REMAINS JUST TO THE SOUTH OF THE TERMINALS TONIGHT.
LIGHT AND VARIABLE WINDS FOR THE MOST PART THIS EVENING. AFTER
MIDNIGHT...WINDS STILL LIGHT BUT PERHAPS FAVORING N-NE.
-SHRA PROBABLE TOWARDS DAYBREAK WITH MVFR CONDITIONS DEVELOPING.
CONDITIONS THEN IMPROVE BY MID AFTN. WINDS REMAINS ON THE LIGHT
SIDE FOR THURS...BUT SOME UNCERTAINTY WITH THE DIRECTION.
.OUTLOOK FOR 00Z FRI THROUGH MON...
.THURSDAY NIGHT...VFR. POSSIBLE SEA BREEZES.
.FRIDAY...VFR.
.SATURDAY...VFR. POSSIBLE PERIODS OF MVFR OR LOWER CONDITIONS
WITH ISOLD SHOWERS/TSTMS.
.SATURDAY NIGHT-MONDAY...MAINLY VFR.
&&
.MARINE...
NO CHANGES AT THIS TIME.
A WEST FLOW BECOMING NORTHWEST LATE THIS EVENING AND OVERNIGHT
WILL KEEP SEAS ON THE OCEAN WATERS AT 3 FT OR LESS.
TRANQUIL CONDITIONS ARE EXPECTED TO CONTINUES ACROSS THE WATERS
THROUGH THURSDAY NIGHT WITH WIND SPEEDS LESS THAN 15 KT AND OCEAN
SEAS OF 3 FT OR LESS. THIS IS EXPECTED AS A RESULT OF A WEAK
PRESSURE GRADIENT.
A WEAK PRESSURE GRADIENT OVER THE AREA WATERS WILL KEEP
CONDITIONS BELOW SMALL CRAFT LEVELS FRIDAY THROUGH MONDAY. SEAS
WILL REMAIN AROUND 2-3 FT WITH GUSTS BELOW 20KT.
&&
.HYDROLOGY...
BASIN AVERAGE QPF THROUGH THU MORNING IS EXPECTED TO RANGE BETWEEN
1/10 TO 1/3 OF AN INCH. NO HYDROLOGIC IMPACTS ARE EXPECTED.
NO WIDESPREAD SIGNIFICANT RAINFALL IS EXPECTED INTO THE UPCOMING
WEEKEND.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MIAMI FL
134 PM EDT THU JUN 19 2014
.AVIATION...
STORMS DEVELOPING JUST WEST OF KPBI EARLY THIS AFTERNOON AND
MOVING SLOWLY EAST AND NORTHEAST. SHOWERS AND STORMS WILL CONTINUE
TO DEVELOP ACROSS THE REGION AND MOVE TOWARD THE EAST COAST TAF
SITES THIS AFTERNOON. SO HAVE TEMPO GROUP FOR ALL OF THE EAST
COAST TAF SITES. IFR CONDITIONS ARE POSSIBLE IN STORMS. LIGHT
SOUTHEAST FLOW WILL CONTINUE THIS AFTERNOON...WITH LIGHT WINDS
TONIGHT THROUGH THE END OF THE TAF PERIOD. AT KAPF...WITH THE
WESTERLY FLOW...JUST KEPT VCSH AS MOST OF THE ACTIVITY SHOULD
REMAIN TO THE EAST AND CONTINUE TO MOVE EAST.
&&
.PREV DISCUSSION... /ISSUED 1001 AM EDT THU JUN 19 2014/
UPDATE...
NOT TOO MANY CHANGES TO OUR CURRENT FORECAST OTHER THAN ADJUSTING
POPS BASED ON CURRENT TRENDS. VERY WEAK PRESSURE GRADIENT EXISTS
ACROSS SOUTH FLORIDA THIS MORNING WITH A WEAK INVERTED SURFACE
TROUGH OFF THE EAST CENTRAL COAST AND VERY WEAK MID/UPPER TROUGH
CENTERED NEAR LAKE OKEECHOBEE. THE GFS AND NAM BOTH SHOW THE
INVERTED TROUGH DEVELOPING INTO A WEAK CLOSED CIRCULATION THIS
AFTERNOON OR TONIGHT AND THEN SLOWLY LIFTING TO THE NORTHEAST. THE
12Z MFL SOUNDING SHOWS A DEEP MOIST ATMOSPHERE WITH PWAT AT 1.77
INCHES AND MODEL FORECAST SOUNDINGS SHOW THAT CONTINUING THROUGH
THE DAY WITH A LIGHT SOUTHWEST STEERING FLOW AT 5 TO 7 MPH. SO IT
APPEARS THAT THE PRIMARY THREAT WILL BE OCCASIONAL TO FREQUENT
LIGHTNING ALONG WITH LOCALLY HEAVY RAINFALL IN SLOW MOVING CELLS.
IT DOES NOT NECESSARILY APPEAR ACCORDING TO THE SOUNDING THAT
THERE IS MUCH OF A WIND THREAT BUT ANY THUNDERSTORM CAN PRODUCE
GUSTY WINDS SO WILL NOT CHANGE THE HWO AT THIS TIME. THE ONLY
OTHER CHANGES POSSIBLE WITH LATER TRENDS MIGHT BE TO ADJUST
AFTERNOON POPS CLOSER TO THE EAST COAST WITH THE SLOW SOUTHWEST
STEERING FLOW. THE LATEST HRRR IS ONLY SHOWING ERRATIC DEVELOPMENT
BUT DOES FAVOR THE NORTHEAST HALF OF THE SOUTHERN PENINSULA.
KOB
PREV DISCUSSION... /ISSUED 740 AM EDT THU JUN 19 2014/
AVIATION...
A WEAK AREA OF LOW PRESSURE WAS OVER THE LOCAL ATLANTIC WATERS
THIS MORNING. THIS LOW IS FORECAST TO DRIFT NORTHWARD THROUGH THE
END OF THE TAF PERIOD. DEEP TROPICAL MOISTURE WILL REMAIN IN PLACE
OVER THE REGION...WITH SHOWERS AND STORMS DEVELOPING CLOSE TO THE
EAST COAST BEGINNING LATE MORNING AND THEN CONTINUING INTO THE
EARLY EVENING. LIGHT WINDS THIS MORNING ARE FORECAST TO BECOME
SOUTHEAST AS THE SEA BREEZE MOVES INLAND THIS AFTERNOON. A GULF
COAST SEA BREEZE IS FORECAST AT KAPF. RAIN COULD CONTINUE NEAR
KPBI OVERNIGHT TONIGHT AND THE LOW REMAINS NEARBY. LIGHT AND
VARIABLE WINDS ARE EXPECTED AGAIN OVERNIGHT. MVFR/IFR CONDITIONS
ARE POSSIBLE IN SHOWERS/STORMS TODAY.
PREV DISCUSSION... /ISSUED 353 AM EDT THU JUN 19 2014/
SHORT TERM...
THE WEATHER PATTERN ACROSS SOUTH FLORIDA WILL REMAIN UNSETTLED AS
AN UPPER LEVEL LOW CONTINUES TO SLOWLY DRIFT OFF THE ATLANTIC
COAST. A WEAK SURFACE LOW IS ALSO TRYING TO DEVELOP AS WELL. THIS
WILL AIDE IN CONVERGENCE ESPECIALLY ACROSS INTERIOR SECTIONS WHICH
WILL ALLOW FOR BETTER CHANCES FOR CONVECTIVE CELLS TO DEVELOP
TODAY. BUFKIT MODEL SOUNDINGS ARE SHOWING THE MBE VECTORS AT ONLY
3-6KTS. SINCE THE SURFACE FLOW WILL BE WEAK, THE THUNDERSTORMS
WILL BE SLOW MOVING. THIS WILL ALLOW FOR THE POTENTIAL FOR
LOCALIZED URBAN FLOODING. COMPARED TO A FEW DAYS AGO, 500 MB
TEMPERATURES HAVE BEEN RUNNING 1 TO 2 DEGREES WARMER, AND THE
FREEZING LEVEL IS SLOWLY RISING, NOW BACK OVER 14KFT, MAKING THE
POTENTIAL FOR HAIL TODAY LOWER. LOOKING AT THE NCAPE, WHICH WAS
LESS THAN .1 ON LAST EVENING SOUNDINGS, AND ALSO ON TODAYS MODEL
NAM SOUNDINGS, WILL EXPECT THE DOWNDRAFT POTENTIAL TO BE LOWER.
WITH A NEARLY SATURATED ATMOSPHERE, ANY DOWNDRAFTS THAT DO DEVELOP WILL
BE WET. AS WITH THE LAST SEVERAL DAYS, THERE IS STILL THE
POTENTIAL FOR SOME STRONG DOWNBURSTS OF BETWEEN 40 AND 50 MPH. SO,
THE POTENTIAL FOR STRONG WINDS AND LOCALIZED URBAN FLOODING STILL
REMAINS IN PLACE. THE THUNDERSTORMS WILL BEGIN TO WEAKEN LATER IN
THE EVENING DUE TO THE LOSS OF DAYTIME HEATING.
THE WEAK UPPER LEVEL LOW WILL REMAIN IN PLACE AT LEAST THROUGH
FRIDAY WHICH WILL ALLOW FOR INCREASED CHANCES OF SHOWERS AND
THUNDERSTORMS TO CONTINUE. SOME OF THESE STORMS COULD BE COME
STRONG AGAIN ESPECIALLY DURING THE AFTERNOON ACROSS THE INTERIOR.
LONG TERM...
THE LATEST COMPUTER MODEL GUIDANCE SUGGESTS THAT THE UPPER LEVEL
LOW WILL REMAIN NEARBY OVER THE UPCOMING WEEKEND AND THEN START TO
PULL AWAY BY THE BEGINNING OF NEXT WEEK. WITH THE TYPICAL
SUMMERTIME MOISTURE STILL REMAINING IN PLACE, THERE WILL BE A
CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS SOUTH FLORIDA THROUGH
THE WEEKEND INTO THE BEGINNING PORTION OF NEXT WEEK.
MARINE...
AN UPPER LEVEL LOW WILL ALLOW FOR PERIODS OF SHOWERS
AND THUNDERSTORMS OVER THE COASTAL WATERS THROUGH THE REMAINDER OF
THE WEEK. MARINE CONDITIONS WITHIN CONVECTION COULD BECOME ROUGH
AT TIMES.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 72 89 74 90 / 30 50 30 30
FORT LAUDERDALE 75 89 76 89 / 30 40 30 20
MIAMI 74 90 75 90 / 30 50 30 30
NAPLES 72 88 73 89 / 30 40 20 40
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...30/KOB
LONG TERM....30/KOB
AVIATION...84/AK
AREA FORECAST DISCUSSION
NWS MIAMI FL
1001 AM EDT THU JUN 19 2014
.UPDATE...
NOT TOO MANY CHANGES TO OUR CURRENT FORECAST OTHER THAN ADJUSTING
POPS BASED ON CURRENT TRENDS. VERY WEAK PRESSURE GRADIENT EXISTS
ACROSS SOUTH FLORIDA THIS MORNING WITH A WEAK INVERTED SURFACE
TROUGH OFF THE EAST CENTRAL COAST AND VERY WEAK MID/UPPER TROUGH
CENTERED NEAR LAKE OKEECHOBEE. THE GFS AND NAM BOTH SHOW THE
INVERTED TROUGH DEVELOPING INTO A WEAK CLOSED CIRCULATION THIS
AFTERNOON OR TONIGHT AND THEN SLOWLY LIFTING TO THE NORTHEAST. THE
12Z MFL SOUNDING SHOWS A DEEP MOIST ATMOSPHERE WITH PWAT AT 1.77
INCHES AND MODEL FORECAST SOUNDINGS SHOW THAT CONTINUING THROUGH
THE DAY WITH A LIGHT SOUTHWEST STEERING FLOW AT 5 TO 7 MPH. SO IT
APPEARS THAT THE PRIMARY THREAT WILL BE OCCASIONAL TO FREQUENT
LIGHTNING ALONG WITH LOCALLY HEAVY RAINFALL IN SLOW MOVING CELLS.
IT DOES NOT NECESSARILY APPEAR ACCORDING TO THE SOUNDING THAT
THERE IS MUCH OF A WIND THREAT BUT ANY THUNDERSTORM CAN PRODUCE
GUSTY WINDS SO WILL NOT CHANGE THE HWO AT THIS TIME. THE ONLY
OTHER CHANGES POSSIBLE WITH LATER TRENDS MIGHT BE TO ADJUST
AFTERNOON POPS CLOSER TO THE EAST COAST WITH THE SLOW SOUTHWEST
STEERING FLOW. THE LATEST HRRR IS ONLY SHOWING ERRATIC DEVELOPMENT
BUT DOES FAVOR THE NORTHEAST HALF OF THE SOUTHERN PENINSULA.
KOB
&&
.PREV DISCUSSION... /ISSUED 740 AM EDT THU JUN 19 2014/
AVIATION...
A WEAK AREA OF LOW PRESSURE WAS OVER THE LOCAL ATLANTIC WATERS
THIS MORNING. THIS LOW IS FORECAST TO DRIFT NORTHWARD THROUGH THE
END OF THE TAF PERIOD. DEEP TROPICAL MOISTURE WILL REMAIN IN PLACE
OVER THE REGION...WITH SHOWERS AND STORMS DEVELOPING CLOSE TO THE
EAST COAST BEGINNING LATE MORNING AND THEN CONTINUING INTO THE
EARLY EVENING. LIGHT WINDS THIS MORNING ARE FORECAST TO BECOME
SOUTHEAST AS THE SEA BREEZE MOVES INLAND THIS AFTERNOON. A GULF
COAST SEA BREEZE IS FORECAST AT KAPF. RAIN COULD CONTINUE NEAR
KPBI OVERNIGHT TONIGHT AND THE LOW REMAINS NEARBY. LIGHT AND
VARIABLE WINDS ARE EXPECTED AGAIN OVERNIGHT. MVFR/IFR CONDITIONS
ARE POSSIBLE IN SHOWERS/STORMS TODAY.
PREV DISCUSSION... /ISSUED 353 AM EDT THU JUN 19 2014/
SHORT TERM...
THE WEATHER PATTERN ACROSS SOUTH FLORIDA WILL REMAIN UNSETTLED AS
AN UPPER LEVEL LOW CONTINUES TO SLOWLY DRIFT OFF THE ATLANTIC
COAST. A WEAK SURFACE LOW IS ALSO TRYING TO DEVELOP AS WELL. THIS
WILL AIDE IN CONVERGENCE ESPECIALLY ACROSS INTERIOR SECTIONS WHICH
WILL ALLOW FOR BETTER CHANCES FOR CONVECTIVE CELLS TO DEVELOP
TODAY. BUFKIT MODEL SOUNDINGS ARE SHOWING THE MBE VECTORS AT ONLY
3-6KTS. SINCE THE SURFACE FLOW WILL BE WEAK, THE THUNDERSTORMS
WILL BE SLOW MOVING. THIS WILL ALLOW FOR THE POTENTIAL FOR
LOCALIZED URBAN FLOODING. COMPARED TO A FEW DAYS AGO, 500 MB
TEMPERATURES HAVE BEEN RUNNING 1 TO 2 DEGREES WARMER, AND THE
FREEZING LEVEL IS SLOWLY RISING, NOW BACK OVER 14KFT, MAKING THE
POTENTIAL FOR HAIL TODAY LOWER. LOOKING AT THE NCAPE, WHICH WAS
LESS THAN .1 ON LAST EVENING SOUNDINGS, AND ALSO ON TODAYS MODEL
NAM SOUNDINGS, WILL EXPECT THE DOWNDRAFT POTENTIAL TO BE LOWER.
WITH A NEARLY SATURATED ATMOSPHERE, ANY DOWNDRAFTS THAT DO DEVELOP WILL
BE WET. AS WITH THE LAST SEVERAL DAYS, THERE IS STILL THE
POTENTIAL FOR SOME STRONG DOWNBURSTS OF BETWEEN 40 AND 50 MPH. SO,
THE POTENTIAL FOR STRONG WINDS AND LOCALIZED URBAN FLOODING STILL
REMAINS IN PLACE. THE THUNDERSTORMS WILL BEGIN TO WEAKEN LATER IN
THE EVENING DUE TO THE LOSS OF DAYTIME HEATING.
THE WEAK UPPER LEVEL LOW WILL REMAIN IN PLACE AT LEAST THROUGH
FRIDAY WHICH WILL ALLOW FOR INCREASED CHANCES OF SHOWERS AND
THUNDERSTORMS TO CONTINUE. SOME OF THESE STORMS COULD BE COME
STRONG AGAIN ESPECIALLY DURING THE AFTERNOON ACROSS THE INTERIOR.
LONG TERM...
THE LATEST COMPUTER MODEL GUIDANCE SUGGESTS THAT THE UPPER LEVEL
LOW WILL REMAIN NEARBY OVER THE UPCOMING WEEKEND AND THEN START TO
PULL AWAY BY THE BEGINNING OF NEXT WEEK. WITH THE TYPICAL
SUMMERTIME MOISTURE STILL REMAINING IN PLACE, THERE WILL BE A
CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS SOUTH FLORIDA THROUGH
THE WEEKEND INTO THE BEGINNING PORTION OF NEXT WEEK.
MARINE...
AN UPPER LEVEL LOW WILL ALLOW FOR PERIODS OF SHOWERS
AND THUNDERSTORMS OVER THE COASTAL WATERS THROUGH THE REMAINDER OF
THE WEEK. MARINE CONDITIONS WITHIN CONVECTION COULD BECOME ROUGH
AT TIMES.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 87 72 89 74 / 50 30 50 30
FORT LAUDERDALE 86 75 89 76 / 50 30 40 30
MIAMI 87 74 90 75 / 50 30 50 30
NAPLES 87 72 88 73 / 50 30 40 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
536 AM EDT THU JUN 19 2014
.SYNOPSIS...
A PRESSURE TROUGH IN THE FORECAST AREA WILL BECOME MORE PRONOUNCED
OVER THE WEEKEND. HIGH PRESSURE ALOFT WILL ALSO WEAKEN. THE
PATTERN SUPPORTS ISOLATED THUNDERSTORMS THIS AFTERNOON...WITH
GREATER COVERAGE TONIGHT THROUGH SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
TODAY...STRONG HEATING AND CONVERGENCE INTO THE LEE-SIDE TROUGH
PLUS A WEAK SHORTWAVE TROUGH CAUGHT IN THE UPPER RIDGE MAY HELP
SUPPORT THUNDERSTORMS THIS AFTERNOON. BELIEVE COVERAGE WILL BE
LIMITED BECAUSE OF SHALLOW MOISTURE AND GENERAL UPPER RIDGING PLUS
SLOW STORM MOVEMENT. THE SPC WRF DISPLAYS JUST ISOLATED COVERAGE
MAINLY IN THE NORTH PART LATE. THE 06Z HRRR SHOWS SCATTERED
COVERAGE IN THE SOUTHEAST PART LIKELY ASSOCIATED WITH SEA-BREEZE
FRONT CONVERGENCE PLUS IN THE NORTH PART LIKELY ALONG THE LEE-
SIDE TROUGH AND CLOSER TO DEEPER MOISTURE. FORECASTED SLIGHT CHANCE POPS
WITH HIGHER VALUES IN THE NORTH PART WHERE BOTH MODELS INDICATED
MORE SIGNIFICANT COVERAGE.
ANY THUNDERSTORMS COULD BE SEVERE. THE ATMOSPHERE WILL BE STRONGLY
UNSTABLE. THE NAM DISPLAYS SURFACE-BASED LI/S NEAR -9 C WITH CAPE
ABOVE 3000 J/KG. THERE WILL BE AN INVERTED-V TYPE SOUNDING WITH
LARGE CAPE IN THE HAIL GROWTH ZONE. WET-BULB ZERO HEIGHTS WILL BE
NEAR 10000 FT. DAMAGING WIND AND HAIL MAY OCCUR.
THE HIGH TEMPERATURE GUIDANCE IS LIKELY A LITTLE TOO COOL BASED ON
RECENT VERIFICATION.
TONIGHT...CONVERGENCE INTO THE SURFACE TROUGH...BOUNDARY
INTERACTION FROM POSSIBLE PREVIOUS CONVECTION PLUS AN H5 SHORTWAVE
TROUGH IN DIFLUENT FLOW MAY HELP SUPPORT THUNDERSTORMS TONIGHT.
THE SPC WRF DISPLAYS CONSIDERABLE COVERAGE. THE NAM MOS POPS HAVE
TRENDED UPWARD. INCREASED POPS TO NEAR AN AVERAGE OF THE GFS AND
NAM MOS. THE LOW TEMPERATURE GUIDANCE IS LIKELY TOO COOL BASED ON
RECENT VERIFICATION.
&&
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
CONVERGENCE INTO THE SURFACE TROUGH PLUS SOME UPPER SUPPORT WITH
AN H5 DIFLUENT FLOW AND POSSIBLE SHORTWAVE TROUGH SUPPORTS
THUNDERSTORMS FRIDAY AND FRIDAY NIGHT ESPECIALLY NEAR THE TIME OF
MAXIMUM HEATING. MOISTURE SHOULD REMAIN SOMEWHAT SHALLOW LIMITING
THUNDERSTORM COVERAGE. AN AVERAGE OF THE GFS AND NAM MOS SUPPORTS
POPS AROUND 30 PERCENT. THE TEMPERATURE GUIDANCE WAS CLOSE.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
THE GFS AND ECMWF KEEP A SURFACE TROUGH OR FRONT NEAR THE FORECAST
AREA THROUGH THE MEDIUM-RANGE PERIOD. IT SHOULD BE AN UNSETTLED
PERIOD WITH THE THUNDERSTORM CHANCE ABOVE CLIMATOLOGY. THE GFS
ENSEMBLE MEANS PLUS GFS...ECMWF...AND EKD MOS HAVE POPS 30 TO 40
PERCENT THROUGH THE PERIOD. MOST OF THE MOS HAS LOWS IN THE LOWER
70S WITH HIGHS IN THE LOWER AND MIDDLE 90S DURING THE PERIOD.
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
LITTLE CHANGE IN THIS STAGNANT PATTERN AND VFR CONDITIONS
EXPECTED THROUGH THE PERIOD EXCEPT FOR BRIEF MVFR VSBYS AT AGS/OGB
DURING THE 08Z-12Z TIME PERIOD DUE TO RADIATIONAL COOLING.
STRONGLY UNSTABLE AIR MASS BY AFTERNOON SHOULD YIELD ISOLATED STORMS
WHICH MAY IMPACT TERMINALS. DUE TO UNCERTAINTY IN THE LOCATION OF
DEVELOPMENT WILL NOT INCLUDE IN THIS FORECAST BUT ALLOW LATER
FORECASTS TO ADDRESS THIS. LIGHT AND VARIABLE WINDS THIS MORNING
WILL PICK UP FROM THE SOUTHWEST AROUND 5 TO 8 KNOTS AFTER 15Z.
EXTENDED AVIATION OUTLOOK...EARLY MORNING FOG POSSIBLE EACH
DAY...MAINLY AT FOG PRONE SITES AGS/OGB. BETTER CHANCE
OF DIURNAL THUNDERSTORMS FRIDAY THROUGH SUNDAY AS UPPER RIDGE
GIVES WAY TO UPPER TROUGH...AND SURFACE TROUGH WITH BETTER
MOISTURE AVAILABLE.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
507 PM CDT THU JUN 19 2014
.MESOSCALE DISCUSSION...
506 PM CDT
ORGANIZED QLCS IS APPROACHING THE MISSISSIPPI RIVER AT THIS TIME
WITH SOME MESOSCALE ORGANIZATION EVIDENT WITH MCV AT THE NORTHERN
FLANK OF THE LINE. KDVN WSR-88D VWP SHOWS SLIGHT STRONGER FLOW ALOFT
THAN RAP SUGGESTS AND RAP DOESNT SEEM TO HAVE A GOOD HANDLE ON THE
ONGOING SITUATION...WHICH RESULTS IN SOMEWHAT LOWER THAN AVERAGE
CONFIDENCE IN HOW THINGS WILL PLAY OUT THIS EVENING. THERE HAS BEEN
EVIDENCE OF OUTFLOW BEGINNING TO SURGE OUT AHEAD OF THE LINE...BUT
WITH AMPLE INSTABILITY PRESENT AHEAD OF THE LINE AND SOME MESOSCALE
ORGANIZATION NOT THINKING THAT ANY WEAKENING OF THE LINE WITH BE
MORE GRADUAL THE NEXT HOUR OR TWO.
CURRENT RADAR/OBSERVATIONAL TRENDS ARE SOMEWHAT CONCERNING REGARDING
THE SHORT TERM (0-6 HOUR) FLASH FLOOD THREAT. LEFT OVER SURFACE
BOUNDARY EXTENDING FROM INDIANAPOLIS NORTHWEST TO NEAR DUBUQUE IS
BEGINNING TO LIGHT UP ACROSS ILLINOIS WEST OF THE NW INDIANA
CONVECTION. KILX VWP SHOWS ABOUT 15 INCREASING TO 20KT SSW FLOW
AROUND 850MB WHICH RIDING OVER THE BOUNDARY SEEMS TO BE SUPPORTING
THE RECENT UPTICK IN CONVECTIVE ACTIVITY ALONG THIS BOUNDARY
EXTENDED SOUTHEAST FROM THE MS RIVER QLCS.
SHORT TERM CONVECTIVE TRENDS WOULD SEEM TO SUPPORT A CONTINUED
FILLING IN OF THE LINE FROM WHITESIDE COUNTY EAST SOUTHEAST TO
BENTON COUNTY...WITH THIS ENTIRE AXIS MOVING GRADUALLY NORTHEAST THE
NEXT COUPLE OF HOURS. WARM CLOUD DEPTH IN EXCESS OF 3500M AND PWATS
NEARING 2 INCHES...WHICH IS ROUGHLY THE 99TH PERCENTILE FOR THIS
TIME OF YEAR...WILL CONTINUE TO SUPPORT VERY EFFICIENT RAINFALL
PRODUCING CONVECTION. THE COMBINATION OF THE WAA WING OF DEVELOPING
THUNDERSTORMS IN CONJUNCTION WITH THE EASTWARD MOVING QLCS COULD
EASILY SUPPORT ISOLATED RAINFALL TOTALS OVER 3 INCHES IN LESS THAN 2
HOURS WHICH IS WELL ABOVE FLASH FLOOD GUIDANCE...PARTICULARLY IN
AREAS WHICH SAW HEAVY RAIN WEDNESDAY EVENING. CURRENT FLASH FLOOD
WATCH ACCURATELY DEPICTS THE HIGHEST THREAT AREA FOR FLASH FLOODING
HEADING INTO THE EARLY EVENING...HOWEVER WILL CONTINUE TO MONITOR
CONVECTIVE TRENDS THE NEXT COUPLE HOURS FOR POSSIBLE NEED FOR AN
EASTWARD EXPANSION OF THE CURRENT WATCH.
IZZI
&&
.DISCUSSION...
302 PM CDT
SYNOPSIS...ANOTHER ROUND OF STORMS IS EXPECTED THIS AFTERNOON AND
TONIGHT...FOLLOWED BY A QUIETER DAY TOMORROW. HOWEVER THE PATTERN
REMAINS BUSY NEXT WEEK. TEMPERATURES WILL BE AT OR ABOVE NORMAL
AWAY FROM THE LAKE THROUGH AT LEAST EARLY NEXT WEEK.
WILL CONTINUE TO CARRY A FLASH FLOOD WATCH FOR LEE...OGLE...AND
WINNEBAGO COUNTIES THROUGH TONIGHT.
REST OF TODAY THROUGH FRIDAY NIGHT...
WE ARE UNDER AN UPPER LEVEL RIDGE BUT AN UPPER LEVEL SHORTWAVE IS
MOVING NORTHEAST AND IS CURRENTLY OVER MISSOURI. AT THE SURFACE
HIGH PRESSURE IS OVER JAMES BAY AND THE EASTERN GREAT LAKES WHILE A
BROAD LOW IS OVER THE NORTHERN PLAINS. A STATIONARY BOUNDARY IS
ACROSS THE SOUTHERN CWA ROUGHLY FROM MOLINE THROUGH CENTRAL IL AND
THEN BACK THROUGH THE CENTRAL APPALACHIANS. WE HAVE RECOVERED
NICELY THIS AFTERNOON WITH AMDAR SOUNDINGS SHOWING ELEVATED CAPE.
SHEAR IS WEAK AT BEST AS IS GENERAL STORM FLOW. SHOWERS AND STORMS
HAVE FORMED ALONG THE BOUNDARY AND OVER SOUTHERN LAKE MI. IN
GENERAL THE STORMS ARE SLOW MOVERS AROUND 15 MPH. WITH PWAT VALUES
STILL HIGH IN EXCESS OF 1.5 INCHES...ANY GIVEN STORM WILL PRODUCE A
HEAVY DOWNPOUR. COMBINE THAT WITH THEIR SLUGGISH MOVEMENT AND WE
WILL PROBABLY HAVE ANOTHER ROUND OF WATER PROBLEMS TO DEAL WITH.
MAY ALSO SEE GUSTY WINDS AND SMALL HAIL FROM THE STRONGEST STORMS
BUT ONLY EXPECTING A FEW TO PULSE UP HIGH ENOUGH TO WARRANT A SPS
OR WARNING. ORGANIZED STORMS ARE NOT ANTICIPATED DUE TO THE WEAK
WIND SHEAR.
ISOLATED TO SCATTERED SHOWERS WILL FIRE ALONG THE BOUNDARY THIS
AFTERNOON AND THEN DIMINISH THIS EVENING. THE LINE OF STORMS
CURRENTLY OVER IOWA WILL SHIFT EAST ACROSS THE AREA TONIGHT BRINGING
ANOTHER ROUND OF HEAVY RAIN. AS MENTIONED ABOVE WILL KEEP THE FLASH
FLOOD WATCH GOING FOR LEE...OGLE...AND WINNEBAGO COUNTIES. GUIDANCE
INDICATES STORM MOTION WILL WEAKEN EVEN FURTHER TONIGHT LEADING TO
EVEN SLOWER MOVING STORMS. ON THE OTHER HAND...GUIDANCE HINTS AT THE
LINE DISSIPATING AS IT MOVES THROUGH THE REGION. THOUGHT ABOUT
EXPANDING THE FLASH FLOOD WATCH EAST TO BOONE AND DEKALB COUNTIES
BUT GIVEN MY UNCERTAINTY IN HOW FAR EAST THE HEAVY RAIN WILL
GET...DID NOT EXPAND WITH THIS ISSUANCE.
THE LINE CONTINUES TO THE EAST TOMORROW WITH CLEARING CONDITIONS
BEHIND IT. ONCE THE SHOWERS AND STORMS SHIFT EAST...TOMORROW LOOKS
LIKE A NICE DAY. HIGHS WILL BE IN THE MID 80S AWAY FROM THE LAKE. A
LAKE BREEZE WILL KEEP AREAS NEAR THE LAKE IN THE 70S. FRIDAY NIGHT
MAY COMPLETELY DRY...BUT GUIDANCE SUGGESTS LAKE EFFECT SHOWERS MAY
FORM AND PUSH INLAND OVERNIGHT. HAVE LOW CONFIDENCE IN THESE LAKE
EFFECT SHOWERS.
SATURDAY THROUGH MONDAY...
WEAK HIGH PRESSURE SETS UP OVER THE REGION SATURDAY BUT IT IS
QUICKLY PUSHED EAST BY A LOW THAT PASSES WELL TO THE NORTH SUNDAY
AND MONDAY. SATURDAY MAY BE DRY AND SIMILAR TO TODAY...A STATIONARY
BOUNDARY MAY BE OVER THE CWA SATURDAY SO HAVE A SLIGHT CHANCE OF
SHOWERS AND STORMS. OVERALL THINKING IT WILL BE MOSTLY DRY. HIGHS
ON SATURDAY WILL BE IN THE MID TO UPPER 80S AWAY FROM THE LAKE WITH
ON SHORE FLOW KEEPING AREAS ALONG THE LAKE IN THE 70S.
PRECIP CHANCES INCREASE OVER THE WEEKEND AS A LOW PRESSURE TROUGH
ASSOCIATED WITH A LOW THAT PASSES WELL TO OUR NORTH MOVES THROUGH
THE REGION. THE BEST CHANCE FOR SHOWERS AND STORMS WILL BE ALONG
THE TROUGH/COLD FRONT MONDAY/MONDAY NIGHT. COULD SEE ANOTHER ROUND
OF HEAVY RAIN AS GUIDANCE FEATURES PWATS AROUND 1.8 INCHES.
TEMPS WILL BE VERY SIMILAR SUNDAY AND MONDAY WITH HIGHS IN THE MID
80S AND LITTLE TO NO LAKE COOLING.
TUESDAY AND WEDNESDAY...
AN UPPER LEVEL TROUGH MOVES OVER THE REGION TUESDAY AND WEDNESDAY.
GUIDANCE DIFFERS ON HOW COOL IT WILL GET UNDER THE TROUGH. RIGHT NOW
HAVE HIGHS IN THE LOWER 80S TO UPPER 70S WHICH WOULD BE A NICE BREAK
FROM THE HEAT. KEPT CHANCES OF SHOWERS AND STORMS IN THE FORECAST
AS THE TROUGH MOVES THROUGH WITH MULTIPLE VORTICITY STREAMERS.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* ISOLATED SHRA/TSRA THROUGH EARLY EVENING.
* TSRA MID/LATE EVENING...WITH ERRATIC WINDS FROM OUTFLOWS.
* POSSIBLE ADDITIONAL SHRA/TSRA OVERNIGHT INTO FRIDAY MORNING.
* BRIEF IFR/MVFR CIGS/VIS WITH TSRA.
* FOG/HAZE TONIGHT/FRIDAY MORNING. CMS
//DISCUSSION...UPDATED 22Z...
ISOLATED SHRA/TSRA HAVE DEVELOPED SOUTH OF ORD TO MDW WITH MORE
SCATTERED COVERAGE FURTHER SOUTH FROM IKK TO RZL. OUTFLOW FROM
THESE STORMS IS MOVING NORTH ACROSS WILL COUNTY BUT APPEARS TO BE
SLOWING AS IT BUMPS INTO COOLER/MORE STABLE NORTHEAST FLOW. IF
THIS WERE TO CONTINUE NORTH...A WIND SHIFT TO THE SOUTHEAST MAY
OCCUR AT MDW/GYY BUT FAIRLY CONFIDENT IT WILL NOT MOVE THAT FAR
NORTH.
ADDITIONAL ISOLATED SHRA/TSRA ARE POSSIBLE IN AND AROUND THE
TERMINALS THROUGH EARLY EVENING BUT FOCUS SHIFTS TO A LINE OF
TSRA MOVING THROUGH THE QUAD CITIES. ITS CURRENT SPEED/MOVEMENT
WOULD BRING IT INTO THE CHICAGO METRO AREA BY MID EVENING.
ADDITIONAL TSRA ARE NOW DEVELOPING AHEAD OF THIS LINE FROM SOUTH
OF SQI TO VYS TO PNT. AND ITS ALSO POSSIBLE THAT THIS COULD FORM A
BROKEN LINE OF TSRA THAT WILL MOVE NORTHEAST ACROSS THE TERMINALS
THIS EVENING. EITHER WAY TSRA ARRIVING AT THE TERMINALS SOONER
APPEARS TO BE REASONABLE AND MOVED UP TIMING WITH THIS UPDATE BUT
TWEAKS/REFINEMENTS WILL LIKELY BE NEEDED WITH LATER FORECASTS. CMS
PREVIOUS 18Z DISCUSSION...
LOW CIGS AND PATCHY FOG HAVE BOTH DISSIPATED WITH ONLY PERIODIC
VFR CIGS POSSIBLE EARLY THIS FORECAST PERIOD. HAVE BEEN MONITORING
AREA OF SHRA/TSRA MOVING EAST/NORTHEAST THROUGH NORTHERN ILLINOIS
THIS MORNING...WITH IT WEAKENING AT THIS TIME AS IT IS
ENCOUNTERING A LESS FAVORABLE ENVIRONMENT FOR DEVELOPMENT. EXPECT
ANY REMAINING SHRA AT THIS TIME TO FURTHER DIMINISH OVER THE NEXT
COUPLE OF HOURS. REDEVELOPMENT OF ISOL TO WIDELY SCT SHRA/TSRA
WILL AGAIN BE POSSIBLE THIS AFTERNOON...BUT WILL BE CONFINED WEST
AND SOUTH OF THE TERMINALS AND TIED MORE CLOSELY TO A SURFACE
BOUNDARY. ANY DEVELOPMENT COULD POSSIBLY DRAW CLOSE TO THE
TERMINALS...IN PARTICULAR RFD AND DPA...BUT WITH ONCE AGAIN THE
MAJORITY OF ANY DEVELOPMENT TO STAY AWAY FROM THE TERMINALS THIS
AFTERNOON. EXPECT INCREASING CHANCES FOR SHRA/TSRA THIS EVENING
AND THEN ESPECIALLY TONIGHT AS AN UPPER LEVEL DISTURBANCE
INTERACTS WITH THIS BOUNDARY. DID TRY AND FOCUS THE
TIMING/DURATION OF THIS PRECIP TONIGHT INTO EARLY FRIDAY MORNING
WITHIN THE TAFS AS WELL AS INCREASING MENTION INTO THE TEMPO AND
PREVAILING GROUPS. CONFIDENCE OF START TIME AND WINDOW FOR BEST
DEVELOPMENT IS HIGHER...BUT WITH LOWER CONFIDENCE WITH THE END TIME
WITH SOME DEVELOPMENT POSSIBLY LINGERING FURTHER INTO FRIDAY
MORNING. EASTERLY WINDS WILL GRADUALLY BECOME MORE SOUTHEAST THIS
EVENING AND OVERNIGHT...BEFORE BECOMING MORE SOUTHERLY FRIDAY
MORNING AND THEN EVENTUALLY WEST/NORTHWEST MID DAY FRIDAY. THESE
NORTHWEST WILL LIKELY SHIFT TO THE NORTHEAST WITH LAKE BREEZE
INTERACTION FRIDAY AFTERNOON...BUT HAVE EXCLUDED MENTION OF IT AT
THIS TIME OWING TO IT BEING VERY LATE IN THE PERIOD.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* MEDIUM FOR TSRA TRENDS/TIMING THROUGH LATE EVENING.
* LOW FOR TSRA TRENDS OVERNIGHT/FRIDAY MORNING.
* MEDIUM FOR WINDS THROUGH THE PERIOD.
* LOW FOR FOG/HAZE TONIGHT/FRIDAY MORNING. CMS
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT THROUGH WEDNESDAY...PRIMARILY VFR WITH PERIODIC
CHANCES FOR THUNDERSTORMS.
BMD
&&
.MARINE...
210 PM CDT
ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS IS EXPECTED ACROSS THE
LAKE TONIGHT AS A MID LEVEL DISTURBANCE MOVES ACROSS THE AREA INTO
FRIDAY. A WEAK SURFACE LOW...AND FRONTAL ZONE WILL SHIFT ACROSS THE
SOUTHERN END OF THE LAKE ON FRIDAY. THIS WILL RESULT IN AN EAST
SOUTHEASTERLY WIND OVER THE LAKE INTO FRIDAY...FOLLOWED BY A PERIOD
OF NORTHERLY WINDS ON THE SOUTH END OF THE LAKE FRIDAY NIGHT INTO
SATURDAY. ADDITIONAL PERIODS OF FOG ARE POSSIBLE DURING THE PERIOD
AS HIGH DEWPOINT AIR REMAINS OVER THE LAKE. WE WILL...HOWEVER...LET
THE CURRENT FOG ADVISORY EXPIRE AS AREA OBSERVATIONS AND WEB CAMS
INDICATE THAT VISIBILITIES HAVE IMPROVED.
THE WEATHER PATTERN IN THE EXTEND PERIOD LOOKS REMAIN SOMEWHAT
ACTIVE AT TIMES...ESPECIALLY EARLY NEXT WEEK. DURING THIS TIME IT
APPEARS ANOTHER WEATHER SYSTEM COULD PRODUCE MORE THUNDERSTORM
ACTIVITY OVER THE LAKES REGION.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLASH FLOOD WATCH...ILZ003-ILZ008-ILZ010 UNTIL 7 AM FRIDAY.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
211 PM CDT THU JUN 19 2014
.DISCUSSION...
1059 AM CDT
THE MAIN CONCERN OVER THE NEXT 24 HOURS IS THE THREAT FOR AN
ADDITIONAL PERIOD OF CONVECTIVE ACTIVITY WITH VERY HEAVY RAINFALL
LIKELY THE MAIN THREAT.
THE SURFACE BOUNDARY LATE THIS MORNING REMAINS IN PLACE ACROSS MY
FAR SOUTHERN CWA ACROSS CENTRAL ILLINOIS...ARCING NORTHWESTWARD INTO
SOUTHEASTERN IOWA. CONVECTIVE ACTIVITY HAS DEVELOPED ACROSS WESTERN
ILLINOIS WITHIN AN AREA OF ENHANCED ISENTROPIC ASCENT ATOP THIS
SURFACE BOUNDARY. THESE THUNDERSTORMS ARE LIKELY PRODUCING SOME
TORRENTIAL DOWNPOURS GIVEN THE PRESENCE OF 1.6 INCH PWATS...PER
KDVN 12 UTC RAOB. THESE STORMS LOOK TO MOVE ACROSS SOME OF MY NORTH
CENTRAL ILLINOIS COUNTIES WITHIN THE NEXT HOUR. THESE ARE ALSO THE
SAME AREAS THAT RECEIVED VERY HEAVY RAINFALL LAST NIGHT. THE GOOD
NEWS IS THAT THESE STORMS ARE MOVING TO THE NORTHEAST AT AROUND 25
KT...SO THEY SHOULD NOT BE OVER A GIVEN AREA TOO LONG. SOME OF THE
LATEST AMDAR SOUNDINGS OUT OF KMDW INDICATE THAT CONDITIONS ARE MORE
STABLE ACROSS NORTHEASTERN ILLINOIS..THEREFORE IT APPEARS THAT THIS
ACTIVITY MAY BEGIN TO WEAKEN AS IT APPROACHES NORTHEASTERN
ILLINOIS.
THE MAIN CONCERN FOR ADDITIONAL CONVECTIVE ACTIVITY ACROSS THE AREA
WILL BE TONIGHT. MODEL GUIDANCE IS INSISTENT ON TAKING A MID LEVEL
DISTURBANCE...CURRENTLY NOTED IN WATER VAPOR IMAGERY PUSHING ACROSS
EASTERN WY...NORTHEASTWARD ACROSS THE DAKOTAS TONIGHT. AS THIS
OCCURS...THIS LOOKS TO HELP STEER SOME ADDITIONAL DISTURBANCES
ACROSS THE CENTRAL PLAINS NORTHEASTWARD ACROSS NORTHERN ILLINOIS
TONIGHT. THEREFORE...AS THE SURFACE BOUNDARY TO OUR SOUTH BEGINS TO
LIFT BACK NORTHWARD ACROSS THE AREA INTO TONIGHT...IT APPEARS
CONDITIONS WILL BE SETTING UP FOR ANOTHER ROUND OF CONVECTIVE
ACTIVITY. THE PRIMARY THREATS FROM THESE STORMS WILL BE VERY HEAVY
RAINFALL...WITH PWATS LIKELY TO BE IN EXCESS OF 1.7 INCHES.
GIVEN THE RAINFALL EXPECTED FROM THIS ACTIVITY OUT WEST...AND THE
LIKELIHOOD OF ANOTHER ROUND ACROSS THE AREA TONIGHT...WE HAVE OPTED
TO ISSUE A FLASH FLOOD WATCH FOR LEE...OGLE AND WINNEBAGO COUNTIES
THROUGH 12 UTC FRIDAY. WE WILL ASSES THE NEED TO EXPAND THIS WATCH
WITH THIS AFTERNOONS PACKAGE.
AREAS OF FOG...DENSE AT TIMES WILL LIKELY CONTINUE INTO THE
AFTERNOON NEAR THE LAKE AS ONSHORE FLOW CONTINUES TO DRAG THIS FOG
OFF THE LAKE.
KJB
//PREV DISCUSSION...
311 AM CDT
FINALLY STARTING TO SEE SOME MOVEMENT IN THE PATTERN AS WELL AS MORE
COHERENT FEATURES TO SERVE AS FORCING MECHANISMS FOR CONVECTION.
THIS EQUATES TO BETTER FORECAST CONFIDENCE THAN THE PAST FEW DAYS.
EARLY MORNING WATER VAPOR IMAGERY SHOWS THE BIG UPPER LOW STILL
SPINNING TO THE WEST THOUGH IT HAS MOVED NORTHEASTWARD AND IS
CURRENTLY OVER FAR SOUTHEAST ALBERTA AND SOUTHWEST SASKATCHEWAN. ITS
NORTHWARD SHIFT HAS ALLOWED FOR THE RIDGE OUT AHEAD OF IT TO SHARPEN
OVER THE MID AND UPPER MISSISSIPPI RIVER VALLEY. FURTHER NORTHEAST
ANOTHER CLOSED UPPER LOW IS OVER QUEBEC AND EASTERN ONTARIO AFTER
SETTLING SOUTHWARD. THIS LEAVES THE LOCAL AREA UNDERNEATH THE UPPER
RIDGE WITH NUMEROUS SMALLER SCALE WAVES HELPING TO PRODUCE
CONVECTION IN THE SOUTHWESTERLY UPPER FLOW ON THE BACK SIDE OF THE
RIDGE ACROSS THE PLAINS AND MID/UPPER MISSISSIPPI RIVER VALLEY. AT
THE SURFACE...LOW PRESSURE IS FOUND OVER EASTERN NEBRASKA AND SOUTH
DAKOTA WITH A QUASI STATIONARY BOUNDARY STRETCHED SOUTHEASTWARD
ACROSS CENTRAL IOWA TO JUST SOUTH OF THE CWA AND INTO CENTRAL
INDIANA. STRONG HIGH PRESSURE OVER HUDSON BAY CONTINUES TO SPREAD
SOUTHWARD ACROSS ONTARIO AND THE NORTHERN GREAT LAKES.
EARLY MORNING...LOW/MID LEVEL WARM ADVECTION CONTINUES TO GENERATE
SHOWERS AND THUNDERSTORMS FROM NORTHEAST IOWA TO NORTHWEST ILLINOIS
TO INDIANA. LEE/OGLE COUNTIES CONTINUE TO SEE NEARLY STATIONARY
CONVECTION OVER THEIR WESTERN PORTIONS WITH RADAR ESTIMATES OF UP TO
10 INCHES AS OF 3 AM. ACTIVITY CONTINUES TO REGENERATE AND WILL
LIKELY DO SO OVER THE NEXT FEW HOURS BUT IT APPEARS THAT THE FOCUS
MAY BE SHIFTING JUST TO THE WEST BUT TI DOES APPEAR THAT IT WILL
CONTINUE ACROSS LEE/OGLE FOR A FEW HOURS YET. ANOTHER AREA OF
STORMS OVER FAR NORTHEAST IOWA HAS SHOWN SOME SIGNS OF LOOSE
ORGANIZATION AS A PROGRESSIVE COMPLEX AS IT MOVES OR PROPAGATES
SOUTHWARD...THOUGH IT IS AT LEAST SEVERAL HOURS OUT FROM REACHING
THE CURRENT CONVECTION. OTHERWISE MORE SCATTERED STORMS WILL
CONTINUE TO MOVE SOUTHEASTWARD ACROSS NORTHEAST IL THROUGH
DAYBREAK.
REST OF TODAY...THE SURFACE LOW OVER EASTERN NEBRASKA/SOUTH DAKOTA
WILL WEAKEN AND LIFT NORTHWARD WHILE THE EASTERN CANADA HIGH PUSHES
SOUTH. THIS WILL KEEP THE STATIONARY FRONT IN THE REGION THOUGH IT
SHOULD LOSE SOME OF ITS FOCUS. CURRENT WARM ADVECTION SHOULD WEAKEN
THROUGH THE MORNING WITH THE MID/UPPER RIDGE OVERHEAD AND WEAKENING
LOW/MID LEVEL WINDS. CURRENT ONGOING SLOW MOVING OR STATIONARY
CONVECTION SHOULD WIND DOWN THROUGH MID MORNING AS THIS FORCING
WEAKENS. HOWEVER...SOME OVERRUNNING/WARM ASCENT WILL STILL BE
OCCURRING OVER THE FRONT SO SCATTERED SHOWERS AND STORMS ARE
POSSIBLE SO WILL MAINTAIN CHANCE POPS THIS MORNING. AFTERNOON
CHANCES LOOK LOW OVERALL BUT WEST AND SOUTHWEST AREAS WILL RETAIN
THE BEST CHANCE FOR ISOLATED TO SCATTERED ACTIVITY. PRECIPITABLE
WATER VALUES WILL REMAIN VERY HIGH AROUND 1.9 INCHES AND STORM
MOVEMENT WILL PROBABLY STILL BE SLOW GIVEN THE WEAKENING UPPER FLOW
UNDER THE RIDGE...SO MORE HEAVY RAIN WILL BE A CONCERN BUT MAY BE
RATHER ISOLATED IN COVERAGE. LOW LEVEL FLOW WILL BE EAST TO
NORTHEAST SO COOLER LAKE AIR WILL BE PUSHING INLAND. EXPECT HIGHS IN
THE UPPER 60S TO AROUND 70 AT THE LAKEFRONT THEN RISE INTO THE 70S
WORKING INLAND...WITH MID TO UPPER 80S FOR THE MAJORITY OF THE
AREA...THOUGH CLOUD COVER MAY KEEP THINGS A LITTLE COOLER. IN
ADDITION...WITH MOIST DEWPOINTS FROM MICHIGAN SPREADING WESTWARD
ACROSS THE LAKE FOG HAS DEVELOPED AND IT MAY CREEP INLAND A SHORT
DISTANCE THROUGH THE MORNING BUT LATEST OBS/WEB CAMS SHOW MINIMAL IF
ANY INLAND PUSH THUS FAR. WILL MENTION FOG NEAR THE IMMEDIATE
LAKESHORE FOR TODAY.
TONIGHT THROUGH FRIDAY...A TROUGH AXIS WILL BE ROTATING AROUND THE
UPPER LOW AND LIFT INTO THE EASTERN DAKOTAS AND MINNESOTA BY
EVENING. THE SURFACE LOW WILL BE ACROSS SOUTHERN SASKATCHEWAN BUT A
WEAK COOL FRONT WILL BE ABLE TO PUSH EASTWARD AS THE UPPER RIDGE
BREAKS DOWN. LARGE SCALE ASCENT WILL INCREASE THURSDAY EVENING WITH
THE SURFACE FRONT REACHING THE AREA FRIDAY MORNING. EXPECT THAT
THERE WILL BE AN INCREASE IN THUNDERSTORM COVERAGE LATER THIS
EVENING OR TONIGHT FROM WEST TO EAST AS ASCENT INCREASES...WITH THE
FRONT ADDING SOME ADDITIONAL LIFT FRIDAY MORNING. WILL CONTINUE WITH
LIKELY POPS DURING THIS PERIOD. WEAK RIDGING WILL DEVELOP ALOFT
LATER FRIDAY LEADING TO A DEEP LAYER OF DRY AIR BUT SURFACE
DEWPOINTS LOOK TO REMAIN HIGH...WITH ONLY VERY SLIGHTLY COOLER
TEMPS. PRECIP CHANCES WILL LINGER THROUGH THE AFTERNOON AS THE
BOUNDARY WILL BE SLOW TO MOVE THROUGH BUT DRIER WEATHER SHOULD BE IN
PLACE BY EVENING. WILL NEED TO BETTER EVALUATE THE HEAVY RAIN
POTENTIAL TONIGHT AND FRIDAY MORNING FOR WESTERN AREAS BUT THE
PRECIP TONIGHT LOOKS TO BE A BIT MORE PROGRESSIVE AND COVERAGE MAY
NOT BE SOLID. WESTERN AREAS ALONG THE I-39 CORRIDOR MAY NEED A FLASH
FLOOD WATCH TONIGHT IF CONVECTION LOOKS MORE ROBUST AND MOVEMENT
SLOWER THAN CURRENTLY THINKING.
SATURDAY AND BEYOND...A MUCH MORE ZONAL UPPER FLOW PATTERN WILL BE
IN PLACE OVER THE WEEKEND INTO EARLY NEXT WEEK. WEAK RIDGING WILL BE
OVERHEAD. THE FORMERLY LARGE UPPER LOW WILL BE WEAKEN OVER THE
CANADIAN PRAIRIES. A LARGE UPPER LOW WILL BE OFF THE BRITISH
COLUMBIA COAST WHICH WILL HAVE SHORTWAVES ROUNDING ITS BASE AND
WORKING EASTWARD THROUGH THE FLOW OVER CENTRAL AND NORTHERN PLAINS
AND INTO THE LOCAL AREA. GUIDANCE CONTINUES TO SHOW DIFFERENCES IN
HOW THE UPPER FLOW EVOLVES EARLY NEXT WEEK AS A WAVE TRACKS ACROSS
SOUTHERN CANADA AND TRIES TO PHASE WITH A STRONGER TROUGH DROPPING
SOUTHWARD ACROSS HUDSON BAY. DESPITE THE DIFFERENCES...IT DOES
APPEAR THAT THE PATTERN WILL ONCE AGAIN BE ACTIVE WITH PERIODIC
THUNDERSTORM CHANCES. INITIALLY IT WILL BE DUE TO THE AFOREMENTIONED
WEAK WAVES TRAVERSING THE ZONAL FLOW...WITH A MORE SUBSTANTIAL
TROUGH DRIVING PRECIPITATION EARLY NEXT WEEK DEPENDING ON HOW IT
EVOLVES. THERE CONTINUES TO BE A SIGNAL FOR COOLER AIR TO WORK INTO
THE REGION BY MID WEEK AS A LARGER SCALE TROUGH SETS UP OVER THE
MIDWEST AND POINTS EAST.
MDB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* REDEVELOPING FOG/HAZE THIS EVENING.
* SHRA/TSRA BECOMING MORE PROBABLE TONIGHT INTO EARLY FRIDAY
MORNING.
* MVFR CONDITIONS POSSIBLE UNDER ANY HEAVIER SHRA/TSRA TONIGHT.
RODRIGUEZ
//DISCUSSION...UPDATED 18Z...
LOW CIGS AND PATCHY FOG HAVE BOTH DISSIPATED WITH ONLY PERIODIC
VFR CIGS POSSIBLE EARLY THIS FORECAST PERIOD. HAVE BEEN MONITORING
AREA OF SHRA/TSRA MOVING EAST/NORTHEAST THROUGH NORTHERN ILLINOIS
THIS MORNING...WITH IT WEAKENING AT THIS TIME AS IT IS
ENCOUNTERING A LESS FAVORABLE ENVIRONMENT FOR DEVELOPMENT. EXPECT
ANY REMAINING SHRA AT THIS TIME TO FURTHER DIMINISH OVER THE NEXT
COUPLE OF HOURS. REDEVELOPMENT OF ISOL TO WIDELY SCT SHRA/TSRA
WILL AGAIN BE POSSIBLE THIS AFTERNOON...BUT WILL BE CONFINED WEST
AND SOUTH OF THE TERMINALS AND TIED MORE CLOSELY TO A SURFACE
BOUNDARY. ANY DEVELOPMENT COULD POSSIBLY DRAW CLOSE TO THE
TERMINALS...IN PARTICULAR RFD AND DPA...BUT WITH ONCE AGAIN THE
MAJORITY OF ANY DEVELOPMENT TO STAY AWAY FROM THE TERMINALS THIS
AFTERNOON. EXPECT INCREASING CHANCES FOR SHRA/TSRA THIS EVENING
AND THEN ESPECIALLY TONIGHT AS AN UPPER LEVEL DISTURBANCE
INTERACTS WITH THIS BOUNDARY. DID TRY AND FOCUS THE
TIMING/DURATION OF THIS PRECIP TONIGHT INTO EARLY FRIDAY MORNING
WITHIN THE TAFS AS WELL AS INCREASING MENTION INTO THE TEMPO AND
PREVAILING GROUPS. CONFIDENCE OF START TIME AND WINDOW FOR BEST
DEVELOPMENT IS HIGHER...BUT WITH LOWER CONFIDENCE WITH THE END TIME
WITH SOME DEVELOPMENT POSSIBLY LINGERING FURTHER INTO FRIDAY
MORNING. EASTERLY WINDS WILL GRADUALLY BECOME MORE SOUTHEAST THIS
EVENING AND OVERNIGHT...BEFORE BECOMING MORE SOUTHERLY FRIDAY
MORNING AND THEN EVENTUALLY WEST/NORTHWEST MID DAY FRIDAY. THESE
NORTHWEST WILL LIKELY SHIFT TO THE NORTHEAST WITH LAKE BREEZE
INTERACTION FRIDAY AFTERNOON...BUT HAVE EXCLUDED MENTION OF IT AT
THIS TIME OWING TO IT BEING VERY LATE IN THE PERIOD.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM CONFIDENCE WITH FOG/HAZE THIS EVENING.
* HIGH CONFIDENCE OF SHRA/TSRA TONIGHT/EARLY FRIDAY
MORNING...MEDIUM CONFIDENCE OF TIMING AND DURATION.
* LOW MEDIUM CONFIDENCE OF MVFR CONDITIONS TONIGHT.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT THROUGH WEDNESDAY...PRIMARILY VFR WITH PERIODIC
CHANCES FOR THUNDERSTORMS.
BMD
&&
.MARINE...
210 PM CDT
ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS IS EXPECTED ACROSS THE
LAKE TONIGHT AS A MID LEVEL DISTURBANCE MOVES ACROSS THE AREA INTO
FRIDAY. A WEAK SURFACE LOW...AND FRONTAL ZONE WILL SHIFT ACROSS THE
SOUTHERN END OF THE LAKE ON FRIDAY. THIS WILL RESULT IN AN EAST
SOUTHEASTERLY WIND OVER THE LAKE INTO FRIDAY...FOLLOWED BY A PERIOD
OF NORTHERLY WINDS ON THE SOUTH END OF THE LAKE FRIDAY NIGHT INTO
SATURDAY. ADDITIONAL PERIODS OF FOG ARE POSSIBLE DURING THE PERIOD
AS HIGH DEWPOINT AIR REMAINS OVER THE LAKE. WE WILL...HOWEVER...LET
THE CURRENT FOG ADVISORY EXPIRE AS AREA OBSERVATIONS AND WEB CAMS
INDICATE THAT VISIBILITIES HAVE IMPROVED.
THE WEATHER PATTERN IN THE EXTEND PERIOD LOOKS REMAIN SOMEWHAT
ACTIVE AT TIMES...ESPECIALLY EARLY NEXT WEEK. DURING THIS TIME IT
APPEARS ANOTHER WEATHER SYSTEM COULD PRODUCE MORE THUNDERSTORM
ACTIVITY OVER THE LAKES REGION.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLASH FLOOD WATCH...ILZ003-ILZ008-ILZ010 UNTIL 7 AM FRIDAY.
IN...NONE.
LM...NONE.
&&
$$
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Area Forecast Discussion
National Weather Service Lincoln IL
107 PM CDT Thu Jun 19 2014
.DISCUSSION...
ISSUED 1054 AM CDT Thu Jun 19 2014
Slow moving frontal boundary draped across northern IL is
providing a focus for scattered showers and thunderstorms mainly
NW of the Illinois River this morning...with the activity
generally moving northward. Plenty of instability remains to the
south of this boundary remains for at least isolated thunderstorms
beginning in the afternoon as daytime heating maximizes. Have
trimmed chances for precipitation until evening from around
Decatur to Lincoln southward but otherwise short term forecast
looks to be in good shape with hot and humid conditions expected
today. Have sent updates to grids and text forecast products to
follow shortly.
&&
.AVIATION...
ISSUED 1236 PM CDT Thu Jun 19 2014
Shower and thunderstorm activity has moved north of the central IL
TAF sites this afternoon while scattered to broken cumulus has
developed throughout much of central IL with bases generally 3-4
kft AGL. Expect isolated to scattered TSRA development increasing
after 19Z continuing into evening.
Main forecast challenge will remain with timing of convection.
With the pop-up nature of the storms in this environment, it is
challenging to narrow down VCTS-free periods, but kept the TAF
sites dry through 19Z and also for a few-hour period this evening.
Similarly, pinning down periods with MVFR or potentially IFR
visibilities due to brief downpours is also tricky.
Onton
&&
.PREV DISCUSSION...
ISSUED 330 AM CDT Thu Jun 19 2014
SHORT TERM...Today through Saturday
Unsettled weather pattern expected through early next work week
with frontal boundary nearby along with disturbance digging into
the upper level ridge over the southeast states. Very warm and
humid tropical air mass to linger through Monday with cooler temps
by middle of next week along with lower humidity levels.
Showers and thunderstorms have mainly been staying north of
central IL so far tonight over northern parts of IL/IN with just
very isolated convection from I-74 north to I-80. 1006 mb low
pressure over east central SD has warm front over central IA into
northern IL north of I-74 but south of I-80 nearing Lacon. Muggy
temps in the 70s over much of central IL in warm sector while
Lacon and Pontiac north of front were cooler 68F. Despite deep
tropical moisture in place and unstable air mass, a weakening low
level jet and lack of an upper level disturbance along with warm
front lifting north of central IL has kept most of central IL dry
during the night. RAP and HRRR models show isolated to scattered
showers and thunderstorms to develop over central IL during the
day mainly after 15Z/10 am and convection could push frontal
boundary back south of I-74. Have higher pops as day progresses
with highest pops over IL river valley and lowest in southeast IL
but still chance pops there this afternoon. SPC keeps slight risk
NW of IL over IA though there is a 5% risk of damaging winds and
large hail this afternoon and evening due to very unstable air mass
with CAPES peaking from 2-3k j/kg this afternoon. Another very
warm and humid day with highs in the upper 80s to around 90F.
Muggy dew points in the lower 70s to give afternoon heat indices
peaking in mid to upper 90s with highest readings in southeast IL.
Not quite as hot as past two days due to more cloud cover and
convection around this afternoon.
Have likely chances of showers and thunderstorms northern areas
tonight with chance pops south of I-72. Most models show some qpf
tonight with low level jet better than this past night though not
terribly strong over central IL. Also have a short wave moving
east across IL so feel more confident with higher pops tonight and
shifting into eastern IL on Friday. Highs in the upper 80s Friday
with southeast IL near 90F and muggy dew points in the lower 70s
still. SPC does not have a slight risk over IL Friday but can not
rule out an isolate strong storm over especially over eastern IL
Friday afternoon. Lingering 20-30% chance of convection Friday
evening south of I-72 as frontal boundary pushes SE of central IL.
Then looks like a break in convection chances overnight Friday
night into Sat. Very warm again Sat with highs in the upper 80s to
near 90F and dew points holding around 70F.
LONG TERM...Saturday night through Thursday
Weak high pressure over the great lakes region Saturday to shift
east Saturday night and Sunday with southerly tropical flow
reestablished over IL and returning chances of showers and
thunderstorms overnight Saturday night and Sunday though less of a
chance over eastern/SE IL closer to retreating ridge. Best chances
of convection appears to be Monday afternoon over IL river valley
and over rest of central/SE IL Monday night and Tue as stronger
upper level trof digs over the Midwest and cold front track SE
through IL. Drier air finally returns later Wed into Thu along
with cooler temperatures as weak high pressure settles into IL.
07
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
106 PM CDT THU JUN 19 2014
.DISCUSSION...
1059 AM CDT
THE MAIN CONCERN OVER THE NEXT 24 HOURS IS THE THREAT FOR AN
ADDITIONAL PERIOD OF CONVECTIVE ACTIVITY WITH VERY HEAVY RAINFALL
LIKELY THE MAIN THREAT.
THE SURFACE BOUNDARY LATE THIS MORNING REMAINS IN PLACE ACROSS MY
FAR SOUTHERN CWA ACROSS CENTRAL ILLINOIS...ARCING NORTHWESTWARD INTO
SOUTHEASTERN IOWA. CONVECTIVE ACTIVITY HAS DEVELOPED ACROSS WESTERN
ILLINOIS WITHIN AN AREA OF ENHANCED ISENTROPIC ASCENT ATOP THIS
SURFACE BOUNDARY. THESE THUNDERSTORMS ARE LIKELY PRODUCING SOME
TORRENTIAL DOWNPOURS GIVEN THE PRESENCE OF 1.6 INCH PWATS...PER
KDVN 12 UTC RAOB. THESE STORMS LOOK TO MOVE ACROSS SOME OF MY NORTH
CENTRAL ILLINOIS COUNTIES WITHIN THE NEXT HOUR. THESE ARE ALSO THE
SAME AREAS THAT RECEIVED VERY HEAVY RAINFALL LAST NIGHT. THE GOOD
NEWS IS THAT THESE STORMS ARE MOVING TO THE NORTHEAST AT AROUND 25
KT...SO THEY SHOULD NOT BE OVER A GIVEN AREA TOO LONG. SOME OF THE
LATEST AMDAR SOUNDINGS OUT OF KMDW INDICATE THAT CONDITIONS ARE MORE
STABLE ACROSS NORTHEASTERN ILLINOIS..THEREFORE IT APPEARS THAT THIS
ACTIVITY MAY BEGIN TO WEAKEN AS IT APPROACHES NORTHEASTERN
ILLINOIS.
THE MAIN CONCERN FOR ADDITIONAL CONVECTIVE ACTIVITY ACROSS THE AREA
WILL BE TONIGHT. MODEL GUIDANCE IS INSISTENT ON TAKING A MID LEVEL
DISTURBANCE...CURRENTLY NOTED IN WATER VAPOR IMAGERY PUSHING ACROSS
EASTERN WY...NORTHEASTWARD ACROSS THE DAKOTAS TONIGHT. AS THIS
OCCURS...THIS LOOKS TO HELP STEER SOME ADDITIONAL DISTURBANCES
ACROSS THE CENTRAL PLAINS NORTHEASTWARD ACROSS NORTHERN ILLINOIS
TONIGHT. THEREFORE...AS THE SURFACE BOUNDARY TO OUR SOUTH BEGINS TO
LIFT BACK NORTHWARD ACROSS THE AREA INTO TONIGHT...IT APPEARS
CONDITIONS WILL BE SETTING UP FOR ANOTHER ROUND OF CONVECTIVE
ACTIVITY. THE PRIMARY THREATS FROM THESE STORMS WILL BE VERY HEAVY
RAINFALL...WITH PWATS LIKELY TO BE IN EXCESS OF 1.7 INCHES.
GIVEN THE RAINFALL EXPECTED FROM THIS ACTIVITY OUT WEST...AND THE
LIKELIHOOD OF ANOTHER ROUND ACROSS THE AREA TONIGHT...WE HAVE OPTED
TO ISSUE A FLASH FLOOD WATCH FOR LEE...OGLE AND WINNEBAGO COUNTIES
THROUGH 12 UTC FRIDAY. WE WILL ASSES THE NEED TO EXPAND THIS WATCH
WITH THIS AFTERNOONS PACKAGE.
AREAS OF FOG...DENSE AT TIMES WILL LIKELY CONTINUE INTO THE
AFTERNOON NEAR THE LAKE AS ONSHORE FLOW CONTINUES TO DRAG THIS FOG
OFF THE LAKE.
KJB
//PREV DISCUSSION...
311 AM CDT
FINALLY STARTING TO SEE SOME MOVEMENT IN THE PATTERN AS WELL AS MORE
COHERENT FEATURES TO SERVE AS FORCING MECHANISMS FOR CONVECTION.
THIS EQUATES TO BETTER FORECAST CONFIDENCE THAN THE PAST FEW DAYS.
EARLY MORNING WATER VAPOR IMAGERY SHOWS THE BIG UPPER LOW STILL
SPINNING TO THE WEST THOUGH IT HAS MOVED NORTHEASTWARD AND IS
CURRENTLY OVER FAR SOUTHEAST ALBERTA AND SOUTHWEST SASKATCHEWAN. ITS
NORTHWARD SHIFT HAS ALLOWED FOR THE RIDGE OUT AHEAD OF IT TO SHARPEN
OVER THE MID AND UPPER MISSISSIPPI RIVER VALLEY. FURTHER NORTHEAST
ANOTHER CLOSED UPPER LOW IS OVER QUEBEC AND EASTERN ONTARIO AFTER
SETTLING SOUTHWARD. THIS LEAVES THE LOCAL AREA UNDERNEATH THE UPPER
RIDGE WITH NUMEROUS SMALLER SCALE WAVES HELPING TO PRODUCE
CONVECTION IN THE SOUTHWESTERLY UPPER FLOW ON THE BACK SIDE OF THE
RIDGE ACROSS THE PLAINS AND MID/UPPER MISSISSIPPI RIVER VALLEY. AT
THE SURFACE...LOW PRESSURE IS FOUND OVER EASTERN NEBRASKA AND SOUTH
DAKOTA WITH A QUASI STATIONARY BOUNDARY STRETCHED SOUTHEASTWARD
ACROSS CENTRAL IOWA TO JUST SOUTH OF THE CWA AND INTO CENTRAL
INDIANA. STRONG HIGH PRESSURE OVER HUDSON BAY CONTINUES TO SPREAD
SOUTHWARD ACROSS ONTARIO AND THE NORTHERN GREAT LAKES.
EARLY MORNING...LOW/MID LEVEL WARM ADVECTION CONTINUES TO GENERATE
SHOWERS AND THUNDERSTORMS FROM NORTHEAST IOWA TO NORTHWEST ILLINOIS
TO INDIANA. LEE/OGLE COUNTIES CONTINUE TO SEE NEARLY STATIONARY
CONVECTION OVER THEIR WESTERN PORTIONS WITH RADAR ESTIMATES OF UP TO
10 INCHES AS OF 3 AM. ACTIVITY CONTINUES TO REGENERATE AND WILL
LIKELY DO SO OVER THE NEXT FEW HOURS BUT IT APPEARS THAT THE FOCUS
MAY BE SHIFTING JUST TO THE WEST BUT TI DOES APPEAR THAT IT WILL
CONTINUE ACROSS LEE/OGLE FOR A FEW HOURS YET. ANOTHER AREA OF
STORMS OVER FAR NORTHEAST IOWA HAS SHOWN SOME SIGNS OF LOOSE
ORGANIZATION AS A PROGRESSIVE COMPLEX AS IT MOVES OR PROPAGATES
SOUTHWARD...THOUGH IT IS AT LEAST SEVERAL HOURS OUT FROM REACHING
THE CURRENT CONVECTION. OTHERWISE MORE SCATTERED STORMS WILL
CONTINUE TO MOVE SOUTHEASTWARD ACROSS NORTHEAST IL THROUGH
DAYBREAK.
REST OF TODAY...THE SURFACE LOW OVER EASTERN NEBRASKA/SOUTH DAKOTA
WILL WEAKEN AND LIFT NORTHWARD WHILE THE EASTERN CANADA HIGH PUSHES
SOUTH. THIS WILL KEEP THE STATIONARY FRONT IN THE REGION THOUGH IT
SHOULD LOSE SOME OF ITS FOCUS. CURRENT WARM ADVECTION SHOULD WEAKEN
THROUGH THE MORNING WITH THE MID/UPPER RIDGE OVERHEAD AND WEAKENING
LOW/MID LEVEL WINDS. CURRENT ONGOING SLOW MOVING OR STATIONARY
CONVECTION SHOULD WIND DOWN THROUGH MID MORNING AS THIS FORCING
WEAKENS. HOWEVER...SOME OVERRUNNING/WARM ASCENT WILL STILL BE
OCCURRING OVER THE FRONT SO SCATTERED SHOWERS AND STORMS ARE
POSSIBLE SO WILL MAINTAIN CHANCE POPS THIS MORNING. AFTERNOON
CHANCES LOOK LOW OVERALL BUT WEST AND SOUTHWEST AREAS WILL RETAIN
THE BEST CHANCE FOR ISOLATED TO SCATTERED ACTIVITY. PRECIPITABLE
WATER VALUES WILL REMAIN VERY HIGH AROUND 1.9 INCHES AND STORM
MOVEMENT WILL PROBABLY STILL BE SLOW GIVEN THE WEAKENING UPPER FLOW
UNDER THE RIDGE...SO MORE HEAVY RAIN WILL BE A CONCERN BUT MAY BE
RATHER ISOLATED IN COVERAGE. LOW LEVEL FLOW WILL BE EAST TO
NORTHEAST SO COOLER LAKE AIR WILL BE PUSHING INLAND. EXPECT HIGHS IN
THE UPPER 60S TO AROUND 70 AT THE LAKEFRONT THEN RISE INTO THE 70S
WORKING INLAND...WITH MID TO UPPER 80S FOR THE MAJORITY OF THE
AREA...THOUGH CLOUD COVER MAY KEEP THINGS A LITTLE COOLER. IN
ADDITION...WITH MOIST DEWPOINTS FROM MICHIGAN SPREADING WESTWARD
ACROSS THE LAKE FOG HAS DEVELOPED AND IT MAY CREEP INLAND A SHORT
DISTANCE THROUGH THE MORNING BUT LATEST OBS/WEB CAMS SHOW MINIMAL IF
ANY INLAND PUSH THUS FAR. WILL MENTION FOG NEAR THE IMMEDIATE
LAKESHORE FOR TODAY.
TONIGHT THROUGH FRIDAY...A TROUGH AXIS WILL BE ROTATING AROUND THE
UPPER LOW AND LIFT INTO THE EASTERN DAKOTAS AND MINNESOTA BY
EVENING. THE SURFACE LOW WILL BE ACROSS SOUTHERN SASKATCHEWAN BUT A
WEAK COOL FRONT WILL BE ABLE TO PUSH EASTWARD AS THE UPPER RIDGE
BREAKS DOWN. LARGE SCALE ASCENT WILL INCREASE THURSDAY EVENING WITH
THE SURFACE FRONT REACHING THE AREA FRIDAY MORNING. EXPECT THAT
THERE WILL BE AN INCREASE IN THUNDERSTORM COVERAGE LATER THIS
EVENING OR TONIGHT FROM WEST TO EAST AS ASCENT INCREASES...WITH THE
FRONT ADDING SOME ADDITIONAL LIFT FRIDAY MORNING. WILL CONTINUE WITH
LIKELY POPS DURING THIS PERIOD. WEAK RIDGING WILL DEVELOP ALOFT
LATER FRIDAY LEADING TO A DEEP LAYER OF DRY AIR BUT SURFACE
DEWPOINTS LOOK TO REMAIN HIGH...WITH ONLY VERY SLIGHTLY COOLER
TEMPS. PRECIP CHANCES WILL LINGER THROUGH THE AFTERNOON AS THE
BOUNDARY WILL BE SLOW TO MOVE THROUGH BUT DRIER WEATHER SHOULD BE IN
PLACE BY EVENING. WILL NEED TO BETTER EVALUATE THE HEAVY RAIN
POTENTIAL TONIGHT AND FRIDAY MORNING FOR WESTERN AREAS BUT THE
PRECIP TONIGHT LOOKS TO BE A BIT MORE PROGRESSIVE AND COVERAGE MAY
NOT BE SOLID. WESTERN AREAS ALONG THE I-39 CORRIDOR MAY NEED A FLASH
FLOOD WATCH TONIGHT IF CONVECTION LOOKS MORE ROBUST AND MOVEMENT
SLOWER THAN CURRENTLY THINKING.
SATURDAY AND BEYOND...A MUCH MORE ZONAL UPPER FLOW PATTERN WILL BE
IN PLACE OVER THE WEEKEND INTO EARLY NEXT WEEK. WEAK RIDGING WILL BE
OVERHEAD. THE FORMERLY LARGE UPPER LOW WILL BE WEAKEN OVER THE
CANADIAN PRAIRIES. A LARGE UPPER LOW WILL BE OFF THE BRITISH
COLUMBIA COAST WHICH WILL HAVE SHORTWAVES ROUNDING ITS BASE AND
WORKING EASTWARD THROUGH THE FLOW OVER CENTRAL AND NORTHERN PLAINS
AND INTO THE LOCAL AREA. GUIDANCE CONTINUES TO SHOW DIFFERENCES IN
HOW THE UPPER FLOW EVOLVES EARLY NEXT WEEK AS A WAVE TRACKS ACROSS
SOUTHERN CANADA AND TRIES TO PHASE WITH A STRONGER TROUGH DROPPING
SOUTHWARD ACROSS HUDSON BAY. DESPITE THE DIFFERENCES...IT DOES
APPEAR THAT THE PATTERN WILL ONCE AGAIN BE ACTIVE WITH PERIODIC
THUNDERSTORM CHANCES. INITIALLY IT WILL BE DUE TO THE AFOREMENTIONED
WEAK WAVES TRAVERSING THE ZONAL FLOW...WITH A MORE SUBSTANTIAL
TROUGH DRIVING PRECIPITATION EARLY NEXT WEEK DEPENDING ON HOW IT
EVOLVES. THERE CONTINUES TO BE A SIGNAL FOR COOLER AIR TO WORK INTO
THE REGION BY MID WEEK AS A LARGER SCALE TROUGH SETS UP OVER THE
MIDWEST AND POINTS EAST.
MDB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* REDEVELOPING FOG/HAZE THIS EVENING.
* SHRA/TSRA BECOMING MORE PROBABLE TONIGHT INTO EARLY FRIDAY
MORNING.
* MVFR CONDITIONS POSSIBLE UNDER ANY HEAVIER SHRA/TSRA TONIGHT.
RODRIGUEZ
//DISCUSSION...UPDATED 18Z...
LOW CIGS AND PATCHY FOG HAVE BOTH DISSIPATED WITH ONLY PERIODIC
VFR CIGS POSSIBLE EARLY THIS FORECAST PERIOD. HAVE BEEN MONITORING
AREA OF SHRA/TSRA MOVING EAST/NORTHEAST THROUGH NORTHERN ILLINOIS
THIS MORNING...WITH IT WEAKENING AT THIS TIME AS IT IS
ENCOUNTERING A LESS FAVORABLE ENVIRONMENT FOR DEVELOPMENT. EXPECT
ANY REMAINING SHRA AT THIS TIME TO FURTHER DIMINISH OVER THE NEXT
COUPLE OF HOURS. REDEVELOPMENT OF ISOL TO WIDELY SCT SHRA/TSRA
WILL AGAIN BE POSSIBLE THIS AFTERNOON...BUT WILL BE CONFINED WEST
AND SOUTH OF THE TERMINALS AND TIED MORE CLOSELY TO A SURFACE
BOUNDARY. ANY DEVELOPMENT COULD POSSIBLY DRAW CLOSE TO THE
TERMINALS...IN PARTICULAR RFD AND DPA...BUT WITH ONCE AGAIN THE
MAJORITY OF ANY DEVELOPMENT TO STAY AWAY FROM THE TERMINALS THIS
AFTERNOON. EXPECT INCREASING CHANCES FOR SHRA/TSRA THIS EVENING
AND THEN ESPECIALLY TONIGHT AS AN UPPER LEVEL DISTURBANCE
INTERACTS WITH THIS BOUNDARY. DID TRY AND FOCUS THE
TIMING/DURATION OF THIS PRECIP TONIGHT INTO EARLY FRIDAY MORNING
WITHIN THE TAFS AS WELL AS INCREASING MENTION INTO THE TEMPO AND
PREVAILING GROUPS. CONFIDENCE OF START TIME AND WINDOW FOR BEST
DEVELOPMENT IS HIGHER...BUT WITH LOWER CONFIDENCE WITH THE END TIME
WITH SOME DEVELOPMENT POSSIBLY LINGERING FURTHER INTO FRIDAY
MORNING. EASTERLY WINDS WILL GRADUALLY BECOME MORE SOUTHEAST THIS
EVENING AND OVERNIGHT...BEFORE BECOMING MORE SOUTHERLY FRIDAY
MORNING AND THEN EVENTUALLY WEST/NORTHWEST MID DAY FRIDAY. THESE
NORTHWEST WILL LIKELY SHIFT TO THE NORTHEAST WITH LAKE BREEZE
INTERACTION FRIDAY AFTERNOON...BUT HAVE EXCLUDED MENTION OF IT AT
THIS TIME OWING TO IT BEING VERY LATE IN THE PERIOD.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM CONFIDENCE WITH FOG/HAZE THIS EVENING.
* HIGH CONFIDENCE OF SHRA/TSRA TONIGHT/EARLY FRIDAY
MORNING...MEDIUM CONFIDENCE OF TIMING AND DURATION.
* LOW MEDIUM CONFIDENCE OF MVFR CONDITIONS TONIGHT.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT THROUGH WEDNESDAY...PRIMARILY VFR WITH PERIODIC
CHANCES FOR THUNDERSTORMS.
BMD
&&
.MARINE...
304 AM CDT
COLD FRONT HAS PUSHED SOUTH OF LAKE MICHIGAN WITH NORTH TO
NORTHEASTERLY WINDS IN PLACE AWAY FROM THE INFLUENCE OF
THUNDERSTORMS WHICH ARE ONGOING ACROSS THE SOUTHERN PORTIONS OF
THE LAKE. THE FRONT WILL LIFT BACK NORTH ACROSS PORTIONS OF THE
LAKE THURSDAY NIGHT INTO EARLY FRIDAY...THE SAG BACK SOUTH AGAIN
OVER THE WEEKEND WITH HIGH PRESSURE BUILDING IN BEHIND THE FRONT.
THE PRESSURE FIELD IS EXPECTED TO BE WEAK AS WE HEAD INTO NEXT
WEEK WHICH WILL RESULT IN RELATIVELY LIGHT WINDS AND SOME
UNCERTAINTY IN THE WIND DIRECTION.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLASH FLOOD WATCH...ILZ003-ILZ008-ILZ010 UNTIL 7 AM FRIDAY.
IN...NONE.
LM...DENSE FOG ADVISORY...LMZ080-LMZ366-LMZ565-LMZ567-LMZ669-LMZ671-
LMZ673-LMZ675-LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-
LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878
UNTIL 4 PM THURSDAY.
&&
$$
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Area Forecast Discussion
National Weather Service Lincoln IL
1117 AM CDT Thu Jun 19 2014
.DISCUSSION...
ISSUED 1054 AM CDT Thu Jun 19 2014
Slow moving frontal boundary draped across northern IL is
providing a focus for scattered showers and thunderstorms mainly
NW of the Illinois River this morning...with the activity
generally moving northward. Plenty of instability remains to the
south of this boundary remains for at least isolated thunderstorms
beginning in the afternoon as daytime heating maximizes. Have
trimmed chances for precipitation until evening from around
Decatur to Lincoln southward but otherwise short term forecast
looks to be in good shape with hot and humid conditions expected
today. Have sent updates to grids and text forecast products to
follow shortly.
Onton
&&
.AVIATION...
ISSUED 630 AM CDT Thu Jun 19 2014
Warm front currently draped over KPIA/KBMI with variable winds
underneath, which will become more southwest over the next couple
hours as the front lifts northward a bit.
Main forecast challenge will remain with timing of convection.
With the pop-up nature of the storms in this environment, it is
challenging to narrow down VCTS-free periods, but kept the TAF
sites dry through 15Z and also for a few-hour period this evening.
Similarly, pinning down periods with MVFR or potentially IFR
visibilities due to brief downpours is also tricky. Based on the
HRRR model, have tried to time such afternoon occurrences at
KSPI/KPIA/KBMI, but will hold off further east for now.
Geelhart
&&
.PREV DISCUSSION...
ISSUED 330 AM CDT Thu Jun 19 2014
SHORT TERM...Today through Saturday
Unsettled weather pattern expected through early next work week
with frontal boundary nearby along with disturbance digging into
the upper level ridge over the southeast states. Very warm and
humid tropical air mass to linger through Monday with cooler temps
by middle of next week along with lower humidity levels.
Showers and thunderstorms have mainly been staying north of
central IL so far tonight over northern parts of IL/IN with just
very isolated convection from I-74 north to I-80. 1006 mb low
pressure over east central SD has warm front over central IA into
northern IL north of I-74 but south of I-80 nearing Lacon. Muggy
temps in the 70s over much of central IL in warm sector while
Lacon and Pontiac north of front were cooler 68F. Despite deep
tropical moisture in place and unstable air mass, a weakening low
level jet and lack of an upper level disturbance along with warm
front lifting north of central IL has kept most of central IL dry
during the night. RAP and HRRR models show isolated to scattered
showers and thunderstorms to develop over central IL during the
day mainly after 15Z/10 am and convection could push frontal
boundary back south of I-74. Have higher pops as day progresses
with highest pops over IL river valley and lowest in southeast IL
but still chance pops there this afternoon. SPC keeps slight risk
NW of IL over IA though there is a 5% risk of damaging winds and
large hail this afternoon and evening due to very unstable air mass
with CAPES peaking from 2-3k j/kg this afternoon. Another very
warm and humid day with highs in the upper 80s to around 90F.
Muggy dew points in the lower 70s to give afternoon heat indices
peaking in mid to upper 90s with highest readings in southeast IL.
Not quite as hot as past two days due to more cloud cover and
convection around this afternoon.
Have likely chances of showers and thunderstorms northern areas
tonight with chance pops south of I-72. Most models show some qpf
tonight with low level jet better than this past night though not
terribly strong over central IL. Also have a short wave moving
east across IL so feel more confident with higher pops tonight and
shifting into eastern IL on Friday. Highs in the upper 80s Friday
with southeast IL near 90F and muggy dew points in the lower 70s
still. SPC does not have a slight risk over IL Friday but can not
rule out an isolate strong storm over especially over eastern IL
Friday afternoon. Lingering 20-30% chance of convection Friday
evening south of I-72 as frontal boundary pushes SE of central IL.
Then looks like a break in convection chances overnight Friday
night into Sat. Very warm again Sat with highs in the upper 80s to
near 90F and dew points holding around 70F.
LONG TERM...Saturday night through Thursday
Weak high pressure over the great lakes region Saturday to shift
east Saturday night and Sunday with southerly tropical flow
reestablished over IL and returning chances of showers and
thunderstorms overnight Saturday night and Sunday though less of a
chance over eastern/SE IL closer to retreating ridge. Best chances
of convection appears to be Monday afternoon over IL river valley
and over rest of central/SE IL Monday night and Tue as stronger
upper level trof digs over the Midwest and cold front track SE
through IL. Drier air finally returns later Wed into Thu along
with cooler temperatures as weak high pressure settles into IL.
07
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
923 AM CDT THU JUN 19 2014
.DISCUSSION...
311 AM CDT
FINALLY STARTING TO SEE SOME MOVEMENT IN THE PATTERN AS WELL AS MORE
COHERENT FEATURES TO SERVE AS FORCING MECHANISMS FOR CONVECTION.
THIS EQUATES TO BETTER FORECAST CONFIDENCE THAN THE PAST FEW DAYS.
EARLY MORNING WATER VAPOR IMAGERY SHOWS THE BIG UPPER LOW STILL
SPINNING TO THE WEST THOUGH IT HAS MOVED NORTHEASTWARD AND IS
CURRENTLY OVER FAR SOUTHEAST ALBERTA AND SOUTHWEST SASKATCHEWAN. ITS
NORTHWARD SHIFT HAS ALLOWED FOR THE RIDGE OUT AHEAD OF IT TO SHARPEN
OVER THE MID AND UPPER MISSISSIPPI RIVER VALLEY. FURTHER NORTHEAST
ANOTHER CLOSED UPPER LOW IS OVER QUEBEC AND EASTERN ONTARIO AFTER
SETTLING SOUTHWARD. THIS LEAVES THE LOCAL AREA UNDERNEATH THE UPPER
RIDGE WITH NUMEROUS SMALLER SCALE WAVES HELPING TO PRODUCE
CONVECTION IN THE SOUTHWESTERLY UPPER FLOW ON THE BACK SIDE OF THE
RIDGE ACROSS THE PLAINS AND MID/UPPER MISSISSIPPI RIVER VALLEY. AT
THE SURFACE...LOW PRESSURE IS FOUND OVER EASTERN NEBRASKA AND SOUTH
DAKOTA WITH A QUASI STATIONARY BOUNDARY STRETCHED SOUTHEASTWARD
ACROSS CENTRAL IOWA TO JUST SOUTH OF THE CWA AND INTO CENTRAL
INDIANA. STRONG HIGH PRESSURE OVER HUDSON BAY CONTINUES TO SPREAD
SOUTHWARD ACROSS ONTARIO AND THE NORTHERN GREAT LAKES.
EARLY MORNING...LOW/MID LEVEL WARM ADVECTION CONTINUES TO GENERATE
SHOWERS AND THUNDERSTORMS FROM NORTHEAST IOWA TO NORTHWEST ILLINOIS
TO INDIANA. LEE/OGLE COUNTIES CONTINUE TO SEE NEARLY STATIONARY
CONVECTION OVER THEIR WESTERN PORTIONS WITH RADAR ESTIMATES OF UP TO
10 INCHES AS OF 3 AM. ACTIVITY CONTINUES TO REGENERATE AND WILL
LIKELY DO SO OVER THE NEXT FEW HOURS BUT IT APPEARS THAT THE FOCUS
MAY BE SHIFTING JUST TO THE WEST BUT TI DOES APPEAR THAT IT WILL
CONTINUE ACROSS LEE/OGLE FOR A FEW HOURS YET. ANOTHER AREA OF
STORMS OVER FAR NORTHEAST IOWA HAS SHOWN SOME SIGNS OF LOOSE
ORGANIZATION AS A PROGRESSIVE COMPLEX AS IT MOVES OR PROPAGATES
SOUTHWARD...THOUGH IT IS AT LEAST SEVERAL HOURS OUT FROM REACHING
THE CURRENT CONVECTION. OTHERWISE MORE SCATTERED STORMS WILL
CONTINUE TO MOVE SOUTHEASTWARD ACROSS NORTHEAST IL THROUGH
DAYBREAK.
REST OF TODAY...THE SURFACE LOW OVER EASTERN NEBRASKA/SOUTH DAKOTA
WILL WEAKEN AND LIFT NORTHWARD WHILE THE EASTERN CANADA HIGH PUSHES
SOUTH. THIS WILL KEEP THE STATIONARY FRONT IN THE REGION THOUGH IT
SHOULD LOSE SOME OF ITS FOCUS. CURRENT WARM ADVECTION SHOULD WEAKEN
THROUGH THE MORNING WITH THE MID/UPPER RIDGE OVERHEAD AND WEAKENING
LOW/MID LEVEL WINDS. CURRENT ONGOING SLOW MOVING OR STATIONARY
CONVECTION SHOULD WIND DOWN THROUGH MID MORNING AS THIS FORCING
WEAKENS. HOWEVER...SOME OVERRUNNING/WARM ASCENT WILL STILL BE
OCCURRING OVER THE FRONT SO SCATTERED SHOWERS AND STORMS ARE
POSSIBLE SO WILL MAINTAIN CHANCE POPS THIS MORNING. AFTERNOON
CHANCES LOOK LOW OVERALL BUT WEST AND SOUTHWEST AREAS WILL RETAIN
THE BEST CHANCE FOR ISOLATED TO SCATTERED ACTIVITY. PRECIPITABLE
WATER VALUES WILL REMAIN VERY HIGH AROUND 1.9 INCHES AND STORM
MOVEMENT WILL PROBABLY STILL BE SLOW GIVEN THE WEAKENING UPPER FLOW
UNDER THE RIDGE...SO MORE HEAVY RAIN WILL BE A CONCERN BUT MAY BE
RATHER ISOLATED IN COVERAGE. LOW LEVEL FLOW WILL BE EAST TO
NORTHEAST SO COOLER LAKE AIR WILL BE PUSHING INLAND. EXPECT HIGHS IN
THE UPPER 60S TO AROUND 70 AT THE LAKEFRONT THEN RISE INTO THE 70S
WORKING INLAND...WITH MID TO UPPER 80S FOR THE MAJORITY OF THE
AREA...THOUGH CLOUD COVER MAY KEEP THINGS A LITTLE COOLER. IN
ADDITION...WITH MOIST DEWPOINTS FROM MICHIGAN SPREADING WESTWARD
ACROSS THE LAKE FOG HAS DEVELOPED AND IT MAY CREEP INLAND A SHORT
DISTANCE THROUGH THE MORNING BUT LATEST OBS/WEB CAMS SHOW MINIMAL IF
ANY INLAND PUSH THUS FAR. WILL MENTION FOG NEAR THE IMMEDIATE
LAKESHORE FOR TODAY.
TONIGHT THROUGH FRIDAY...A TROUGH AXIS WILL BE ROTATING AROUND THE
UPPER LOW AND LIFT INTO THE EASTERN DAKOTAS AND MINNESOTA BY
EVENING. THE SURFACE LOW WILL BE ACROSS SOUTHERN SASKATCHEWAN BUT A
WEAK COOL FRONT WILL BE ABLE TO PUSH EASTWARD AS THE UPPER RIDGE
BREAKS DOWN. LARGE SCALE ASCENT WILL INCREASE THURSDAY EVENING WITH
THE SURFACE FRONT REACHING THE AREA FRIDAY MORNING. EXPECT THAT
THERE WILL BE AN INCREASE IN THUNDERSTORM COVERAGE LATER THIS
EVENING OR TONIGHT FROM WEST TO EAST AS ASCENT INCREASES...WITH THE
FRONT ADDING SOME ADDITIONAL LIFT FRIDAY MORNING. WILL CONTINUE WITH
LIKELY POPS DURING THIS PERIOD. WEAK RIDGING WILL DEVELOP ALOFT
LATER FRIDAY LEADING TO A DEEP LAYER OF DRY AIR BUT SURFACE
DEWPOINTS LOOK TO REMAIN HIGH...WITH ONLY VERY SLIGHTLY COOLER
TEMPS. PRECIP CHANCES WILL LINGER THROUGH THE AFTERNOON AS THE
BOUNDARY WILL BE SLOW TO MOVE THROUGH BUT DRIER WEATHER SHOULD BE IN
PLACE BY EVENING. WILL NEED TO BETTER EVALUATE THE HEAVY RAIN
POTENTIAL TONIGHT AND FRIDAY MORNING FOR WESTERN AREAS BUT THE
PRECIP TONIGHT LOOKS TO BE A BIT MORE PROGRESSIVE AND COVERAGE MAY
NOT BE SOLID. WESTERN AREAS ALONG THE I-39 CORRIDOR MAY NEED A FLASH
FLOOD WATCH TONIGHT IF CONVECTION LOOKS MORE ROBUST AND MOVEMENT
SLOWER THAN CURRENTLY THINKING.
SATURDAY AND BEYOND...A MUCH MORE ZONAL UPPER FLOW PATTERN WILL BE
IN PLACE OVER THE WEEKEND INTO EARLY NEXT WEEK. WEAK RIDGING WILL BE
OVERHEAD. THE FORMERLY LARGE UPPER LOW WILL BE WEAKEN OVER THE
CANADIAN PRAIRIES. A LARGE UPPER LOW WILL BE OFF THE BRITISH
COLUMBIA COAST WHICH WILL HAVE SHORTWAVES ROUNDING ITS BASE AND
WORKING EASTWARD THROUGH THE FLOW OVER CENTRAL AND NORTHERN PLAINS
AND INTO THE LOCAL AREA. GUIDANCE CONTINUES TO SHOW DIFFERENCES IN
HOW THE UPPER FLOW EVOLVES EARLY NEXT WEEK AS A WAVE TRACKS ACROSS
SOUTHERN CANADA AND TRIES TO PHASE WITH A STRONGER TROUGH DROPPING
SOUTHWARD ACROSS HUDSON BAY. DESPITE THE DIFFERENCES...IT DOES
APPEAR THAT THE PATTERN WILL ONCE AGAIN BE ACTIVE WITH PERIODIC
THUNDERSTORM CHANCES. INITIALLY IT WILL BE DUE TO THE AFOREMENTIONED
WEAK WAVES TRAVERSING THE ZONAL FLOW...WITH A MORE SUBSTANTIAL
TROUGH DRIVING PRECIPITATION EARLY NEXT WEEK DEPENDING ON HOW IT
EVOLVES. THERE CONTINUES TO BE A SIGNAL FOR COOLER AIR TO WORK INTO
THE REGION BY MID WEEK AS A LARGER SCALE TROUGH SETS UP OVER THE
MIDWEST AND POINTS EAST.
MDB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* IFR CIGS THIS MORNING LIFTING TO VFR BY EARLY AFTERNOON.
* PATCHY FOG THROUGH LATE MORNING.
* PERIODIC CHANCES OF THUNDERSTORMS THROUGH THE FORECAST PERIOD.
RODRIGUEZ
//DISCUSSION...UPDATED 12Z...
A FRONTAL BOUNDARY STRETCHES WEST TO EAST ACROSS PORTIONS OF CENTRAL
ILLINOIS THIS MORNING WITH THUNDERSTORMS ONGOING NORTH OF THE
BOUNDARY. SATELLITE AND LIGHTENING TRENDS INDICATE THAT THE COMPLEX
OF THUNDERSTORMS IS WEAKENING ACROSS NORTHERN ILLINOIS THOUGH MORE
ROBUST CONVECTION IS OCCURRING ACROSS IOWA. IT APPEARS THAT THE
CHICAGO TERMINALS MAY BE OUT OF THE GREATEST THREAT FOR
THUNDERSTORMS FOR THE REMAINDER OF THE MORNING WHILE RFD WILL SEE
THE THREAT CONTINUE TO DIMINISH OVER THE NEXT COUPLE HOURS. MORE
STABLE CONDITIONS ARE EXPECTED TODAY AND CLOUD COVER AND LINGERING
COLD POOL/OUTFLOW WILL MAKE IT DIFFICULT TO RECOVER. IN ADDITION...
BUILDING MID-LEVEL HEIGHTS WILL HELP SUPPRESS GROWTH ACROSS THE
AREA. APPEARS THE BEST CHANCES FOR TSRA WILL BE ALONG AND
WEST OF THE MISSISSIPPI RIVER TODAY BUT CANNOT RULE OUT SOME
SCATTERED CONVECTION SOUTH OF THE TERMINALS ALONG THE OUTFLOW
REINFORCED FRONTAL BOUNDARY. THIS EVENING THE MID LEVEL RIDGE AXIS
BEGINS TO SHIFT EAST WITH MODELS ADVERTISING THE TAIL END OF A
SHORTWAVE TROUGH LIFTING ACROSS THE REGION. THIS SHOULD BE ABLE TO
KICK OFF ADDITIONAL THUNDERSTORMS ACROSS THE AREA THOUGH EXACT
LOCATION REMAINS IN QUESTION.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* MEDIUM CONFIDENCE IN CIG TRENDS/TIMING.
* HIGH CONFIDENCE WITH FOG TRENDS THIS MORNING.
* MEDIUM CONFIDENCE IN DRY WEATHER THE REST OF THE MORNING. LOW
CONFIDENCE IN THUNDERSTORMS AT THE TERMINALS THIS AFTERNOON.
MEDIUM CONFIDENCE IN THUNDERSTORMS RETURNING LATE THIS
EVENING/TONIGHT.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT THROUGH WEDNESDAY...PRIMARILY VFR WITH PERIODIC
CHANCES FOR THUNDERSTORMS.
BMD
&&
.MARINE...
304 AM CDT
COLD FRONT HAS PUSHED SOUTH OF LAKE MICHIGAN WITH NORTH TO
NORTHEASTERLY WINDS IN PLACE AWAY FROM THE INFLUENCE OF
THUNDERSTORMS WHICH ARE ONGOING ACROSS THE SOUTHERN PORTIONS OF
THE LAKE. THE FRONT WILL LIFT BACK NORTH ACROSS PORTIONS OF THE
LAKE THURSDAY NIGHT INTO EARLY FRIDAY...THE SAG BACK SOUTH AGAIN
OVER THE WEEKEND WITH HIGH PRESSURE BUILDING IN BEHIND THE FRONT.
THE PRESSURE FIELD IS EXPECTED TO BE WEAK AS WE HEAD INTO NEXT
WEEK WHICH WILL RESULT IN RELATIVELY LIGHT WINDS AND SOME
UNCERTAINTY IN THE WIND DIRECTION.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...DENSE FOG ADVISORY...LMZ080-LMZ366-LMZ565-LMZ567-LMZ669-LMZ671-
LMZ673-LMZ675-LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-
LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878
UNTIL 4 PM THURSDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
National Weather Service Lincoln IL
630 AM CDT Thu Jun 19 2014
.DISCUSSION...
ISSUED 330 AM CDT Thu Jun 19 2014
SHORT TERM...Today through Saturday
Unsettled weather pattern expected through early next work week
with frontal boundary nearby along with disturbance digging into
the upper level ridge over the southeast states. Very warm and
humid tropical air mass to linger through Monday with cooler temps
by middle of next week along with lower humidity levels.
Showers and thunderstorms have mainly been staying north of
central IL so far tonight over northern parts of IL/IN with just
very isolated convection from I-74 north to I-80. 1006 mb low
pressure over east central SD has warm front over central IA into
northern IL north of I-74 but south of I-80 nearing Lacon. Muggy
temps in the 70s over much of central IL in warm sector while
Lacon and Pontiac north of front were cooler 68F. Despite deep
tropical moisture in place and unstable air mass, a weakening low
level jet and lack of an upper level disturbance along with warm
front lifting north of central IL has kept most of central IL dry
during the night. RAP and HRRR models show isolated to scattered
showers and thunderstorms to develop over central IL during the
day mainly after 15Z/10 am and convection could push frontal
boundary back south of I-74. Have higher pops as day progresses
with highest pops over IL river valley and lowest in southeast IL
but still chance pops there this afternoon. SPC keeps slight risk
NW of IL over IA though there is a 5% risk of damaging winds and
large hail this afternoon and evening due to very unstable air mass
with CAPES peaking from 2-3k j/kg this afternoon. Another very
warm and humid day with highs in the upper 80s to around 90F.
Muggy dew points in the lower 70s to give afternoon heat indices
peaking in mid to upper 90s with highest readings in southeast IL.
Not quite as hot as past two days due to more cloud cover and
convection around this afternoon.
Have likely chances of showers and thunderstorms northern areas
tonight with chance pops south of I-72. Most models show some qpf
tonight with low level jet better than this past night though not
terribly strong over central IL. Also have a short wave moving
east across IL so feel more confident with higher pops tonight and
shifting into eastern IL on Friday. Highs in the upper 80s Friday
with southeast IL near 90F and muggy dew points in the lower 70s
still. SPC does not have a slight risk over IL Friday but can not
rule out an isolate strong storm over especially over eastern IL
Friday afternoon. Lingering 20-30% chance of convection Friday
evening south of I-72 as frontal boundary pushes SE of central IL.
Then looks like a break in convection chances overnight Friday
night into Sat. Very warm again Sat with highs in the upper 80s to
near 90F and dew points holding around 70F.
LONG TERM...Saturday night through Thursday
Weak high pressure over the great lakes region Saturday to shift
east Saturday night and Sunday with southerly tropical flow
reestablished over IL and returning chances of showers and
thunderstorms overnight Saturday night and Sunday though less of a
chance over eastern/SE IL closer to retreating ridge. Best chances
of convection appears to be Monday afternoon over IL river valley
and over rest of central/SE IL Monday night and Tue as stronger
upper level trof digs over the Midwest and cold front track SE
through IL. Drier air finally returns later Wed into Thu along
with cooler temperatures as weak high pressure settles into IL.
07
&&
.AVIATION...
ISSUED 630 AM CDT Thu Jun 19 2014
Warm front currently draped over KPIA/KBMI with variable winds
underneath, which will become more southwest over the next couple
hours as the front lifts northward a bit.
Main forecast challenge will remain with timing of convection.
With the pop-up nature of the storms in this environment, it is
challenging to narrow down VCTS-free periods, but kept the TAF
sites dry through 15Z and also for a few-hour period this evening.
Similarly, pinning down periods with MVFR or potentially IFR
visibilities due to brief downpours is also tricky. Based on the
HRRR model, have tried to time such afternoon occurrences at
KSPI/KPIA/KBMI, but will hold off further east for now.
Geelhart
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
400 AM CDT THU JUN 19 2014
.DISCUSSION...
311 AM CDT
FINALLY STARTING TO SEE SOME MOVEMENT IN THE PATTERN AS WELL AS MORE
COHERENT FEATURES TO SERVE AS FORCING MECHANISMS FOR CONVECTION.
THIS EQUATES TO BETTER FORECAST CONFIDENCE THAN THE PAST FEW DAYS.
EARLY MORNING WATER VAPOR IMAGERY SHOWS THE BIG UPPER LOW STILL
SPINNING TO THE WEST THOUGH IT HAS MOVED NORTHEASTWARD AND IS
CURRENTLY OVER FAR SOUTHEAST ALBERTA AND SOUTHWEST SASKATCHEWAN. ITS
NORTHWARD SHIFT HAS ALLOWED FOR THE RIDGE OUT AHEAD OF IT TO SHARPEN
OVER THE MID AND UPPER MISSISSIPPI RIVER VALLEY. FURTHER NORTHEAST
ANOTHER CLOSED UPPER LOW IS OVER QUEBEC AND EASTERN ONTARIO AFTER
SETTLING SOUTHWARD. THIS LEAVES THE LOCAL AREA UNDERNEATH THE UPPER
RIDGE WITH NUMEROUS SMALLER SCALE WAVES HELPING TO PRODUCE
CONVECTION IN THE SOUTHWESTERLY UPPER FLOW ON THE BACK SIDE OF THE
RIDGE ACROSS THE PLAINS AND MID/UPPER MISSISSIPPI RIVER VALLEY. AT
THE SURFACE...LOW PRESSURE IS FOUND OVER EASTERN NEBRASKA AND SOUTH
DAKOTA WITH A QUASI STATIONARY BOUNDARY STRETCHED SOUTHEASTWARD
ACROSS CENTRAL IOWA TO JUST SOUTH OF THE CWA AND INTO CENTRAL
INDIANA. STRONG HIGH PRESSURE OVER HUDSON BAY CONTINUES TO SPREAD
SOUTHWARD ACROSS ONTARIO AND THE NORTHERN GREAT LAKES.
EARLY MORNING...LOW/MID LEVEL WARM ADVECTION CONTINUES TO GENERATE
SHOWERS AND THUNDERSTORMS FROM NORTHEAST IOWA TO NORTHWEST ILLINOIS
TO INDIANA. LEE/OGLE COUNTIES CONTINUE TO SEE NEARLY STATIONARY
CONVECTION OVER THEIR WESTERN PORTIONS WITH RADAR ESTIMATES OF UP TO
10 INCHES AS OF 3 AM. ACTIVITY CONTINUES TO REGENERATE AND WILL
LIKELY DO SO OVER THE NEXT FEW HOURS BUT IT APPEARS THAT THE FOCUS
MAY BE SHIFTING JUST TO THE WEST BUT TI DOES APPEAR THAT IT WILL
CONTINUE ACROSS LEE/OGLE FOR A FEW HOURS YET. ANOTHER AREA OF
STORMS OVER FAR NORTHEAST IOWA HAS SHOWN SOME SIGNS OF LOOSE
ORGANIZATION AS A PROGRESSIVE COMPLEX AS IT MOVES OR PROPAGATES
SOUTHWARD...THOUGH IT IS AT LEAST SEVERAL HOURS OUT FROM REACHING
THE CURRENT CONVECTION. OTHERWISE MORE SCATTERED STORMS WILL
CONTINUE TO MOVE SOUTHEASTWARD ACROSS NORTHEAST IL THROUGH
DAYBREAK.
REST OF TODAY...THE SURFACE LOW OVER EASTERN NEBRASKA/SOUTH DAKOTA
WILL WEAKEN AND LIFT NORTHWARD WHILE THE EASTERN CANADA HIGH PUSHES
SOUTH. THIS WILL KEEP THE STATIONARY FRONT IN THE REGION THOUGH IT
SHOULD LOSE SOME OF ITS FOCUS. CURRENT WARM ADVECTION SHOULD WEAKEN
THROUGH THE MORNING WITH THE MID/UPPER RIDGE OVERHEAD AND WEAKENING
LOW/MID LEVEL WINDS. CURRENT ONGOING SLOW MOVING OR STATIONARY
CONVECTION SHOULD WIND DOWN THROUGH MID MORNING AS THIS FORCING
WEAKENS. HOWEVER...SOME OVERRUNNING/WARM ASCENT WILL STILL BE
OCCURRING OVER THE FRONT SO SCATTERED SHOWERS AND STORMS ARE
POSSIBLE SO WILL MAINTAIN CHANCE POPS THIS MORNING. AFTERNOON
CHANCES LOOK LOW OVERALL BUT WEST AND SOUTHWEST AREAS WILL RETAIN
THE BEST CHANCE FOR ISOLATED TO SCATTERED ACTIVITY. PRECIPITABLE
WATER VALUES WILL REMAIN VERY HIGH AROUND 1.9 INCHES AND STORM
MOVEMENT WILL PROBABLY STILL BE SLOW GIVEN THE WEAKENING UPPER FLOW
UNDER THE RIDGE...SO MORE HEAVY RAIN WILL BE A CONCERN BUT MAY BE
RATHER ISOLATED IN COVERAGE. LOW LEVEL FLOW WILL BE EAST TO
NORTHEAST SO COOLER LAKE AIR WILL BE PUSHING INLAND. EXPECT HIGHS IN
THE UPPER 60S TO AROUND 70 AT THE LAKEFRONT THEN RISE INTO THE 70S
WORKING INLAND...WITH MID TO UPPER 80S FOR THE MAJORITY OF THE
AREA...THOUGH CLOUD COVER MAY KEEP THINGS A LITTLE COOLER. IN
ADDITION...WITH MOIST DEWPOINTS FROM MICHIGAN SPREADING WESTWARD
ACROSS THE LAKE FOG HAS DEVELOPED AND IT MAY CREEP INLAND A SHORT
DISTANCE THROUGH THE MORNING BUT LATEST OBS/WEB CAMS SHOW MINIMAL IF
ANY INLAND PUSH THUS FAR. WILL MENTION FOG NEAR THE IMMEDIATE
LAKESHORE FOR TODAY.
TONIGHT THROUGH FRIDAY...A TROUGH AXIS WILL BE ROTATING AROUND THE
UPPER LOW AND LIFT INTO THE EASTERN DAKOTAS AND MINNESOTA BY
EVENING. THE SURFACE LOW WILL BE ACROSS SOUTHERN SASKATCHEWAN BUT A
WEAK COOL FRONT WILL BE ABLE TO PUSH EASTWARD AS THE UPPER RIDGE
BREAKS DOWN. LARGE SCALE ASCENT WILL INCREASE THURSDAY EVENING WITH
THE SURFACE FRONT REACHING THE AREA FRIDAY MORNING. EXPECT THAT
THERE WILL BE AN INCREASE IN THUNDERSTORM COVERAGE LATER THIS
EVENING OR TONIGHT FROM WEST TO EAST AS ASCENT INCREASES...WITH THE
FRONT ADDING SOME ADDITIONAL LIFT FRIDAY MORNING. WILL CONTINUE WITH
LIKELY POPS DURING THIS PERIOD. WEAK RIDGING WILL DEVELOP ALOFT
LATER FRIDAY LEADING TO A DEEP LAYER OF DRY AIR BUT SURFACE
DEWPOINTS LOOK TO REMAIN HIGH...WITH ONLY VERY SLIGHTLY COOLER
TEMPS. PRECIP CHANCES WILL LINGER THROUGH THE AFTERNOON AS THE
BOUNDARY WILL BE SLOW TO MOVE THROUGH BUT DRIER WEATHER SHOULD BE IN
PLACE BY EVENING. WILL NEED TO BETTER EVALUATE THE HEAVY RAIN
POTENTIAL TONIGHT AND FRIDAY MORNING FOR WESTERN AREAS BUT THE
PRECIP TONIGHT LOOKS TO BE A BIT MORE PROGRESSIVE AND COVERAGE MAY
NOT BE SOLID. WESTERN AREAS ALONG THE I-39 CORRIDOR MAY NEED A FLASH
FLOOD WATCH TONIGHT IF CONVECTION LOOKS MORE ROBUST AND MOVEMENT
SLOWER THAN CURRENTLY THINKING.
SATURDAY AND BEYOND...A MUCH MORE ZONAL UPPER FLOW PATTERN WILL BE
IN PLACE OVER THE WEEKEND INTO EARLY NEXT WEEK. WEAK RIDGING WILL BE
OVERHEAD. THE FORMERLY LARGE UPPER LOW WILL BE WEAKEN OVER THE
CANADIAN PRAIRIES. A LARGE UPPER LOW WILL BE OFF THE BRITISH
COLUMBIA COAST WHICH WILL HAVE SHORTWAVES ROUNDING ITS BASE AND
WORKING EASTWARD THROUGH THE FLOW OVER CENTRAL AND NORTHERN PLAINS
AND INTO THE LOCAL AREA. GUIDANCE CONTINUES TO SHOW DIFFERENCES IN
HOW THE UPPER FLOW EVOLVES EARLY NEXT WEEK AS A WAVE TRACKS ACROSS
SOUTHERN CANADA AND TRIES TO PHASE WITH A STRONGER TROUGH DROPPING
SOUTHWARD ACROSS HUDSON BAY. DESPITE THE DIFFERENCES...IT DOES
APPEAR THAT THE PATTERN WILL ONCE AGAIN BE ACTIVE WITH PERIODIC
THUNDERSTORM CHANCES. INITIALLY IT WILL BE DUE TO THE AFOREMENTIONED
WEAK WAVES TRAVERSING THE ZONAL FLOW...WITH A MORE SUBSTANTIAL
TROUGH DRIVING PRECIPITATION EARLY NEXT WEEK DEPENDING ON HOW IT
EVOLVES. THERE CONTINUES TO BE A SIGNAL FOR COOLER AIR TO WORK INTO
THE REGION BY MID WEEK AS A LARGER SCALE TROUGH SETS UP OVER THE
MIDWEST AND POINTS EAST.
MDB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 09Z...
* TSRA THROUGH SUNRISE.
* SMALL CHANCE OF TSRA LATE MORNING/EARLY AFTERNOON.
* TSRA LATE THURSDAY NIGHT INTO FRIDAY MORNING.
* IFR CIGS THROUGH SUNRISE/MVFR CIGS THURSDAY MORNING.
* NORTHEAST/EAST WINDS THROUGH THE PERIOD. CMS/BMD
//DISCUSSION...UPDATED 06Z...
NO SIGNS OF TSRA ENDING OR DISSIPATING AND WILL CONTINUE WITH THE
MOST RECENT AMENDMENTS OF TSRA MENTION NOW THROUGH 11Z. WITH THE
BULK OF THIS ACTIIVTY BEING DRIVEN BY WARM AIR ADVECTION...EXPECT
TO SEE SOME WEAKENING AROUND/AFTER SUNRISE BUT NOT CONFIDENT IN
EXACT END TIME AND ACTIVITY COULD PERSIST BEYOND SUNRISE. THERE
ARE TRENDS SUGGESTING ACTIVITY WILL END OR BE SHIFTING WEST BY
MID MORNING WITH THE POSSIBILITY OF ADDITIONAL ACTIVITY DEVELOPING
WITH DAYTIME HEATING IN THE LATE MORNING OR EARLY AFTERNOON. IF
THIS OCCURS...IT SHOULD BE SHORT LIVED AS FOCUS FOR CONVECTION
SHIFTS WEST THROUGH THE DAY LEAVING MAINLY DRY CONDITIONS INTO
THE EVENING HOURS. MORE DISCERNABLE UPPER LEVEL WAVE PROGGED TO
MOVE ACROSS THE REGION LATER THURSDAY NIGHT INTO FRIDAY MORNING
WITH ADDITIONAL TSRA POSSIBLE DURING THIS TIME AND DESPITE CURRENT
DISTANCE...24-30 HRS...ADDED PROB MENTION TO ORD/S TAF.
IFR CIGS HAVE BEEN IN AND OUT AT ORD/MDW AND WITH THE COOLER
NORTHEAST FLOW...MOIST LOW LEVELS AND CONTINUED TSRA ACTIVITY...
POTENTIAL FOR IFR CIGS WILL CONTINUE BUT JUST NOT SURE HOW
WIDESPREAD OR HOW LONG THEY WILL PERSIST. BUT HAVE BEEN CARRYING
THEM ALL EVENING AND WILL CONTINUE WITH IFR CIGS OVERNIGHT WITH
CIGS LIFTING TO MVFR EITHER BY SUNRISE OR SHORTLY THEREAFTER.
DESPITE EASTERLY WINDS...IF WINDS DIMINISH ENOUGH OVERNIGHT INTO
MID THURSDAY MORNING...THERE COULD BE A LAKE BREEZE LATER THIS
AFTERNOON...WITH A SHIFT MORE TO THE NORTHEAST. SPEEDS WILL THEN
DIMINISH SOME THIS EVENING. CMS
//ORD AND MDW CONFIDENCE...UPDATED 09Z...
* HIGH FOR TSRA THROUGH SUNRISE.
* LOW FOR TSRA DURING DAYLIGHT HOURS TODAY.
* MEDIUM FOR TSRA THURSDAY NIGHT/FRIDAY MORNING.
* MEDIUM-HIGH FOR IFR CIGS THROUGH SUNRISE...MEDIUM FOR MVFR CIGS
THURSDAY MORNING.
* MEDIUM FOR WINDS THROUGH THE PERIOD. CMS/BMD
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
* FRIDAY THROUGH TUESDAY...CHANCE OF TSRA.
&&
.MARINE...
304 AM CDT
COLD FRONT HAS PUSHED SOUTH OF LAKE MICHIGAN WITH NORTH TO
NORTHEASTERLY WINDS IN PLACE AWAY FROM THE INFLUENCE OF
THUNDERSTORMS WHICH ARE ONGOING ACROSS THE SOUTHERN PORTIONS OF
THE LAKE. THE FRONT WILL LIFT BACK NORTH ACROSS PORTIONS OF THE
LAKE THURSDAY NIGHT INTO EARLY FRIDAY...THE SAG BACK SOUTH AGAIN
OVER THE WEEKEND WITH HIGH PRESSURE BUILDING IN BEHIND THE FRONT.
THE PRESSURE FIELD IS EXPECTED TO BE WEAK AS WE HEAD INTO NEXT
WEEK WHICH WILL RESULT IN RELATIVELY LIGHT WINDS AND SOME
UNCERTAINTY IN THE WIND DIRECTION.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
National Weather Service Lincoln IL
330 AM CDT Thu Jun 19 2014
.DISCUSSION...
ISSUED 330 AM CDT Thu Jun 19 2014
SHORT TERM...Today through Saturday
Unsettled weather pattern expected through early next work week
with frontal boundary nearby along with disturbance digging into
the upper level ridge over the southeast states. Very warm and
humid tropical airmass to linger through Monday with cooler temps
by middle of next week along with lower humidity levels.
Showers and thunderstorms have mainly been staying north of
central IL so far tonight over northern parts of IL/IN with just
very isolated convection from I-74 north to I-80. 1006 mb low
pressure over east central SD has warm front over central IA into
northern IL north of I-74 but south of I-80 nearing Lacon. Muggy
temps in the 70s over much of central IL in warm sector while
Lacon and Pontiac north of front were cooler 68F. Despite deep
tropical moisture in place and unstable airmass, a weakening low
level jet and lack of an upper level disturbance along with warm
front lifting north of central IL has kept most of central IL dry
during the night. RAP and HRRR models show isolated to scattered
showers and thunderstorms to develop over central IL during the
day mainly after 15Z/10 am and convection could push frontal
boundary back south of I-74. Have higher pops as day progresses
with highest pops over IL river valley and lowest in southeast IL
but still chance pops there this afternoon. SPC keeps slight risk
nw of IL over IA though there is a 5% risk of damaging winds and
large hail this afternoon and evening due to very unstable airmass
with CAPES peaking from 2-3k j/kg this afternoon. Another very
warm and humid day with highs in the upper 80s to around 90F.
Muggy dewpoints in the lower 70s to give afternoon heat indices
peaking in mid to upper 90s with highest readings in southeast IL.
Not quite as hot as past two days due to more cloud cover and
convection around this afternoon.
Have likely chances of showers and thunderstorms northern areas
tonight with chance pops south of I-72. Most models show some qpf
tonight with low level jet better than this past night though not
terribly strong over central IL. Also have a short wave moving
east across IL so feel more confident with higher pops tonight and
shifting into eastern IL on Friday. Highs in the upper 80s Friday
with southeast IL near 90F and muggy dewpoints in the lower 70s still.
SPC does not have a slight risk over IL Friday but can not rule
out an isolate strong storm over especially over eastern IL Friday
afternoon. Lingering 20-30% chance of convection Friday evening
south of I-72 as frontal boundary pushes se of central IL. Then
looks like a break in convection chances overnight Friday night
into Sat. Very warm again Sat with highs in the upper 80s to near 90F
and dewpoints holding around 70F.
LONG TERM...Saturday night through Thursday
Weak high pressure over the great lakes region Saturday to shift
east Saturday night and Sunday with southerly tropical flow
reestablished over IL and returning chances of showers and
thunderstorms overnight Saturday night and Sunday though less of a
chance over eastern/se IL closer to retreating ridge. Best chances
of convection appears to be Monday afternoon over IL river valley
and over rest of central/se IL Monday night and Tue as stronger
upper level trof digs over the Midwest and cold front track se
through IL. Drier air finally returns later Wed into Thu along
with cooler temperatures as weak high pressure settles into IL.
07
&&
.AVIATION...
ISSUED 1158 PM CDT Wed Jun 18 2014
Models widely varied with solutions for the storms edging towards
the CWA...again. Keeping mention of VCTS in the northern terminals
PIA and BMI, VCSH for CMI. S/SWrly winds dominate, though winds will
likely see a temp change of direction with any convection/outflow
that moves through the area. Debris cirrus from regional
convection...cu tomorrow midday with more debris cirrus. Keeping
the vcts mention until the confidence is there that a terminal
will be affected. Chances increasing overnight...and into the
morning hours, but the cold pool will have to become strong enough
to push the boundary back to the south. So far, the warm front
creeping northward is keeping the bulk of the convection north.
Confidence in coverage and timing very low.
HJS
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
100 PM CDT THU JUN 19 2014
.UPDATE...
ISSUED AT 1225 PM CDT THU JUN 19 2014
COLD FRONT HAS MADE IT TO KSLN TO JUST WEST OF KINGMAN. THE FRONT
CONTINUES TO MOVE EAST AT A SLOW PACE. CLOUDS FINALLY CLEARING IN
THE VICINITY OF THE FRONT. SHOWERS IN EASTERN KANSAS HAVE MOVED
OUT.
WATCHING TO SEE JUST HOW MUCH HEATING WILL OCCUR IN THE CLEARING
AREA AHEAD OF THE FRONT. DEEP LAYER SHEAR REMAINS MARGINAL AT
BEST...IN THE VICINITY OF THE FRONT. SEVERE LOOKING LESS LIKELY.
LAST SEVERAL HRRR AND RAP RUNS CONTINUE TO DECREASE THE CHANCE OF
PRECIPITATION ALONG THE FRONT. AS STATED...WILL WATCH TO SEE HOW
CAPES RESPOND IN THE CLEARING AREA. HAVE KEPT THE FORECAST AS IS
UNTIL OBSERVED TRENDS SUGGEST OTHERWISE.
COOK
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 225 AM CDT THU JUN 19 2014
OVERNIGHT CONVECTION OVER OKLAHOMA COULD SPREAD NORTHEAST INTO THE
FRINGES OF SOUTHEAST KANSAS AROUND DAYBREAK...AS THE LOW LEVEL JET
VEERS OUT. MEANWHILE...THE SURFACE FRONT CURRENTLY OVER CENTRAL
NEBRASKA/NORTHWEST KANSAS WILL MIGRATE SLOWLY SOUTHEAST TODAY AND
BECOME THE FOCUS FOR RE-NEWED THUNDERSTORM DEVELOPMENT DURING THE
AFTERNOON/EVENING...MAINLY OVER CENTRAL AND SOUTH CENTRAL KANSAS.
DAYTIME HEATING OF THE MOIST AIRMASS IN PLACE WILL MAKE FOR VERY
UNSTABLE CONDITIONS AND ADEQUATE SHEAR ALOFT SHOULD GIVE WAY TO A
FEW STRONG TO SEVERE STORMS. THE STORMS WILL MOVE SLOWLY EASTWARD
TONIGHT AS LOW LEVEL JET VEERS OUT AGAIN. OTHERWISE THE WEATHER
PATTERN LOOKS TO CALM DOWN FOR THUNDERSTORM ACTIVITY ON
FRIDAY/SATURDAY ACROSS THE AREA...WITH WARM AND HUMID CONDITIONS
PREVAILING.
.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 225 AM CDT THU JUN 19 2014
MODEL TRENDS CONTINUE TO SHOW A DECENT SIGNAL FOR CONVECTION TO
DEVELOP OVER THE HIGH PLAINS ON SUNDAY AFTERNOON..THEN ROLL EASTWARD
OFF THE HIGH PLAINS INTO CENTRAL AND EASTERN KANSAS FOR SUNDAY
NIGHT/MONDAY AS A FORWARD PROPAGATING MCS. THE UPPER WAVE
RESPONSIBLE FOR THIS MCS ACTIVITY SHOULD PUSH THE FRONTAL BOUNDARY
SOUTH OF KANSAS HEADING INTO TUESDAY AND WEDNESDAY AND WE WILL LOWER
PRECIPITATION CHANCES. HOWEVER THE BOUNDARY COULD TRY AND MIGRATE
BACK NORTHWARD BY MID-WEEK FROM SO WE WILL KEEP SOME SMALL
PRECIPITATION CHANCES CONFINED TO SOUTHERN KANSAS.
JAKUB
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1225 PM CDT THU JUN 19 2014
COLD FRONT HAS MADE IT TO KSLN TO JUST WEST OF KINGMAN. THE FRONT
CONTINUES TO MOVE EAST AT A SLOW PACE. CLOUDS FINALLY CLEARING IN
THE VICINITY OF THE FRONT. SHOWERS IN EASTERN KANSAS HAVE MOVED
OUT.
BEHIND THE FRONT...WINDS WILL REMAIN LIGHT WITH VFR CONDITIONS FOR
THE NEXT 24 HOURS. AHEAD OF THE FRONT...A SMALL CHANCE OF TSRA
REMAINS. CONFIDENCE GETTING WORSE THOUGH WITH THIS. THINKING BEST
CHANCE OF CONVECTION IS EAST OF THE KANSAS TURNPIKE. THESE SHOULD
PRODUCE SOME LOCAL IFR CONDITIONS. OTHERWISE...SOUTH WINDS GUSTING
TO 20 KNOTS WILL DECREASE THIS EVENING...BECOMING LIGHT AND
VARIABLE AFTER SUNSET. VFR CIGS/VSBYS.
THE FRONT MOVES SOUTH OF THE FORECAST AREA TONIGHT.
COOK
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 86 69 91 70 / 40 40 10 10
HUTCHINSON 88 68 92 70 / 30 40 10 10
NEWTON 85 69 90 69 / 30 40 10 10
ELDORADO 82 69 89 69 / 40 40 10 10
WINFIELD-KWLD 80 69 89 70 / 40 40 10 10
RUSSELL 86 66 94 68 / 10 20 10 10
GREAT BEND 88 67 93 68 / 20 20 10 10
SALINA 88 68 93 70 / 20 30 10 10
MCPHERSON 88 68 91 69 / 30 40 10 10
COFFEYVILLE 81 70 88 70 / 50 40 20 10
CHANUTE 82 69 88 70 / 40 40 20 10
IOLA 83 69 88 70 / 30 40 20 10
PARSONS-KPPF 81 70 88 70 / 40 40 20 10
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1217 AM CDT Thu Jun 19 2014
...Updated aviation section...
.SHORT TERM...(This evening through Thursday)
ISSUED AT 251 PM CDT WED JUN 18 2014
A minor upper level trough is currently moving through western
Kansas, with the stronger dynamics centered off to the north of our
CWA. There is a cold front in the vicinity from Hays to north of
Syracuse in Hamilton County as of 20z. A dry-line has formed and
was from approximately Liberal to Garden City to Hill City at 20z.
There was a lower level wave which moved up from the Texas Panhandle
earlier this afternoon, which shoved the dry-line northeastward into
the cold front, causing the cold front to bow northward in the Ness
City/Hays area. This dry-line intrusion into the cold front also
slowed the progress of the front to the southeast. A fairly good
amount of mid to high level clouds covered most of the CWA at 20z,
and a single storm formed near Scott City between 19Z and 20Z. The
short term models of the RUC, HRRR and ARW all backed off on a solid
line of storms forming along the dry-line this afternoon, but rather
a patchy line of storms. There will still probably be a few
isolated severe storms with quarter size hail, but do not think the
severe storms will be widespread or very big hail (quarters). Will
monitor SPC for a Watch.
Overnight, the precipitation band from this afternoon should move
east, with another surface low moving up from Oklahoma into the P28
area. The aforementioned front will progress southeast through our
CWA and be near a Pratt to Coldwater line by 12Z in the morning.
Therefore, with greater moisture available in the southeast zones,
will increase Pops there toward 12Z, and then spread the Pops back
to the northwest during the day Thursday. SPC`s Day2 outlook has
about our southeast 1/3rd of the CWA in a slight risk. We will be
cooler in the afternoon, with the cold front south of us. Have to
agree with SPC`s assessment though, with the NAM model showing 3700
J/Kg of MuCape in our eastern zones, and 24 to 27Kts of bulk shear
in that same zone Tuesday at 21Z. There will likely be some more
severe storms, again with Quarters to a little larger hail. The TOR
threat looks minimal, but some 60kt winds could easily mix down.
As for Max/Min temperatures, I did not change anything. Lows
tonight will be elevated in the 60F (NW) to 72F (SE) range. On
Thursday, it will be cooler with maximum temperatures ranging from
the mid 80s north of I-70 and upper 80s down south along the
Oklahoma border.
.LONG TERM...(Thursday night through Wednesday)
ISSUED AT 346 PM CDT WED JUN 18 2014
The mid to upper level flow will become zonal by later this week and
into the weekend. This will allow for lee troughing and a dryline situated
across far western Kansas. Afternoon and early nighttime
thunderstorms cannot be ruled out. But in the absence of upslope
flow this far south, and with the lack of low level baroclinicity
and a well defined upper level jet, organized thunderstorm
activity will probably stay farther north through Saturday. High
temperatures will be in the lower 90s through Saturday with lows
mainly in the 60s. Thunderstorm chances are higher by late Sunday
as a weak shortwave trough embedded in zonal flow traverses
western Kansas. Organized thunderstorm activity is possible into
Monday with this feature, along with cooler temperatures by
Monday. Thunderstorm chances may diminish by late Monday and
Tuesday as weak surface high pressure builds into western Kansas.
However, by late Tuesday and into mid to late next week, there
will be more opportunities for thunderstorms as westerly to
northwesterly mid to high level flow persists, along with weak
capping and plentiful low level moisture. High temperatures will
be held down by cloud cover and convective debris.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
ISSUED AT 1215 AM CDT THU JUN 19 2014
VFR conditions will prevail with decreasing high level clouds.
Winds will start out from the south overnight shifting to the
northwest by sunrise tomorrow. this is due to a cold front moving
through the area.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 63 91 68 94 / 20 20 20 10
GCK 62 92 66 94 / 10 20 20 10
EHA 63 91 66 94 / 10 10 20 10
LBL 64 92 68 95 / 20 10 20 10
HYS 62 91 67 93 / 10 20 20 20
P28 67 91 70 93 / 40 20 20 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Burke
LONG TERM...Finch
AVIATION...Hovorka_42
AREA FORECAST DISCUSSION
NWS WICHITA KS
1140 PM CDT WED JUN 18 2014
...UPDATED FOR 06Z AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 317 PM CDT WED JUN 18 2014
UPPER LEVEL DATA ANALYSIS ENDING AT 19Z SHOWS A CLOSED LOW AT 500 MB
OVER SOUTHWEST MONTANA. SOUTHWESTERLY FLOW CONTINUES ACROSS THE
REGION AS A RESULT OF THIS LOW. THIS LOW CONTINUES TO MOVE SLOWLY
NORTHEASTWARD.
SATELLITE DATA LOOP ENDING AT 1915Z SHOWS AN AREA OF ACCAS THAT HAS
EXTENDED FROM THE TEXAS PANHANDLE INTO CENTRAL KANSAS. THIS HAS
BEEN PRESENT FOR SEVERAL HOURS AND OUTLINES THE AREA OF FAVORED
CONVECTIVE INITIATION THIS AFTERNOON.
AT THE SURFACE...LOW PRESSURE WAS CENTERED OVER SOUTH CENTRAL SOUTH
DAKOTA. A COLD FRONT EXTENDS FROM THIS LOW DOWN TO NEAR
KODX-KTQK-KLIC. A DRYLINE EXTENDS FROM JUST WEST OF KGCK...SOUTH TO
JUST WEST OF KLBL INTO THE OKLAHOMA AND TEXAS PANHANDLE.
CONVECTIVE DEVELOPMENT HAS INITIATED ACROSS WEST TEXAS ALONG THE
AFOREMENTIONED FAVORED AREA. THIS IS PRETTY CLOSE TO WHERE THE 17Z HRRR
RUN HAS SHOWN IT.
MAIN FORECAST CHALLENGE REMAINS CONVECTION.
COOK
&&
.UPDATE...
ISSUED AT 958 PM CDT WED JUN 18 2014
LATEST SHORT TERM AND HIGH RESOLUTION GUIDANCE CONTINUES TO
INDICATE A LACK OF CONVECTION DURING THE OVERNIGHT HOURS. THE
STORM OVER BARTON/RUSSELL COUNTIES WILL PERSIST FOR A LITTLE
WHILE...BUT NOT ANTICIPATING STORMS MOVING INTO SOUTH CENTRAL
KANSAS AS EARLIER GUIDANCE INDICATED. DID HOWEVER LEAVE SLIGHT
POPS OVERNIGHT FOR SOUTH CENTRAL KANSAS FOR THE CHANCE THAT SOME
OF THE STORMS FROM THE TX/OKLAHOMA PANHANDLE MAKES IT THIS FAR
EAST. THINK THE BETTER CHANCES WILL BE THURSDAY MORNING ACROSS
EASTERN KANSAS.
BILLINGS WRIGHT
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 317 PM CDT WED JUN 18 2014
THE TREND OF THE HRRR RUNS FOR CONVECTION THIS EVENING CONTINUES TO
SHOW MORE RAINFALL FOR A GOOD PORTION OF THE FORECAST AREA. THIS IS
A DIVERGENCE TO THE OTHER NWP...BUT GIVEN ITS ACCURACY AND
PERFORMANCE...WILL MAKE ADJUSTMENTS TO THE FORECAST FOR
TONIGHT.
AS FAR AS SEVERE GOES...SHEAR/BUOYANCY COMBINATIONS SUGGEST
POTENTIAL FOR ORGANIZED CONVECTION ACROSS WESTERN KANSAS. AS ONE
MOVES EAST...DEEP LAYER SHEAR FALLS BELOW 20 KNOTS BEFORE YOU REACH
INTERSTATE 135. THIS SHOULD PRECLUDE SEVERE CONVECTION EAST OF
INTERSTATE 135.
THE AFOREMENTIONED COLD FRONT WILL MOVE SOUTH INTO THE FORECAST AREA
THURSDAY. THIS WILL BE THE FOCUS FOR CONVECTION THURSDAY
AFTERNOON. SHEAR/BUOYANCY COMBINATIONS AGAIN LOOK
FAVORABLE...THOUGH ON THE LOWER END OF THAT FAVORABLY FOR
ORGANIZED CONVECTION FOR SEVERE WEATHER. THIS FAVORABLY WILL
REMAIN IN THE VICINITY OF THE FRONT. IF STORMS STRAY FROM OR
ORGANIZE AND MOVE AWAY FROM THE FRONT AND OUTRUN THE FAVORABLE DEEP
LAYER SHEAR...THEY SHOULD WEAKEN.
COOK
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 317 PM CDT WED JUN 18 2014
INTO THE WEEKEND...THE QUASI-STATIONARY FRONT REMAINS AROUND THE
REGION. NWP IS IN SOME DISARRAY WITH THE POSITION OF THE
BOUNDARY...AFFECTED BY OUTFLOWS AND COLD POOLS. CONFIDENCE IN
CONVECTION LOCATION IS QUITE LOW. THAT SAID...CONFIDENCE IS HIGH
THAT THE FRONT REMAINS IN CLOSE ENOUGH PROXIMITY TO THE FORECAST
AREA INTO THE MIDDLE OF NEXT WEEK...WITH FAVORABLE CONDITIONS FOR
LATE AFTERNOON AND NOCTURNAL CONVECTION. SEVERE CONDITIONS WILL BE
FAVORABLE NEAR THE STALLED FRONT...WHICH SHEAR/BUOYANCY COMBINATIONS
ARE MOST FAVORABLE.
COOK
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1140 PM CDT WED JUN 18 2014
CONVECTION HAS WANED THIS EVENING/EARLY OVERNIGHT HOURS AND EXPECT
THAT TO REMAIN FOR MOST OF THE NEXT 12 HOURS OR SO. THERE IS A
CHANCE SOME CONVECTION MOVING NORTHEAST COULD IMPACT KICT OVER THE
NEXT 4-5 HOURS...BUT CONFIDENCE ON THE ACTIVITY OVER THE
TEXAS/OKLAHOMA PANHANDLES MAKING IT THIS FAR EAST IS NOT OVERLY
HIGH. WINDS IN CENTRAL KANSAS ARE BEING IMPACTED BY THE OUTFLOW
FOR EARLIER STORMS...EXPECT SOUTHERLY WINDS TO TAKE OVER AS THIS
LAYER ERODES.
THE NEXT GOOD CHANCE FOR CONVECTION IS THURSDAY MORNING/AFTERNOON
AND MAINLY ACROSS EASTERN KANSAS. THIS MAY IMPACT MANY OF THE
TERMINALS...BUT WITH MODEL DESCREPANCES...CONFIDENCE IS REALLY
LOW ON TIMING AND LOCATION AND HAVE LEFT OUT OF THIS ISSUANCE.
LOW VFR TO MVFR CEILINGS MAY BE POSSIBLE BEHIND THE FRONT THAT
GETS STALLED UP BETWEEN KRSL/KSLN THURSDAY AFTERNOON/EVENING.
BILLINGS WRIGHT
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 73 90 70 90 / 20 50 70 30
HUTCHINSON 73 90 69 91 / 30 50 70 20
NEWTON 72 88 69 90 / 20 50 70 20
ELDORADO 72 86 68 88 / 20 60 70 30
WINFIELD-KWLD 73 88 70 90 / 20 50 60 30
RUSSELL 70 89 66 92 / 50 40 40 20
GREAT BEND 70 89 67 92 / 50 40 50 20
SALINA 73 90 68 92 / 20 50 60 20
MCPHERSON 72 89 68 91 / 20 50 70 20
COFFEYVILLE 74 85 70 88 / 10 50 50 30
CHANUTE 73 85 69 88 / 20 50 50 30
IOLA 73 85 69 88 / 20 50 50 30
PARSONS-KPPF 73 85 70 88 / 10 50 50 30
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS JACKSON KY
316 PM EDT THU JUN 19 2014
.UPDATE...
ISSUED AT 211 PM EDT THU JUN 19 2014
ISOLD TO SCATTERED CONVECTION CONTINUES TO FIRE ACROSS PORTIONS OF THE
FORECAST AREA THIS AFTERNOON. SHOWERS AND THUNDERSTORMS DEVELOPING
ALONG SEVERAL OUTFLOW BOUNDARIES LEFT OVER FROM MORNING CONVECTION
WHERE LATE SPRING SUN HAS BEEN STRONG ENOUGH TO DESTABILIZE THE
BOUNDARY LAYER. STRONGEST CONVECTION ATTM IS LOCATED TO THE SOUTH
ALONG THE TN/KY STATE LINE. HOWEVER CLUSTER OF STORMS MOVING THROUGH
CENTRAL KENTUCKY IS PUTTING OUT A FAIRLY CLEAR OUTFLOW BOUNDARY THAT
SHOULD BE MOVING INTO THE WESTERN PORTIONS OF OUR CWA IN A COUPLE
HOURS. THAT MAY BE ONE OF THE MAIN FOCUSES OF ACTIVITY THROUGH THE
REMAINDER OF THE AFTERNOON. ANOTHER PREDOMINANT BOUNDARY THAT APPEARS
PRIMED FOR SOME REDEVELOPMENT IS CURRENTLY DRAPED ACROSS THE
NORTHEASTERN THIRD OF OUR CWA...STRETCHING ROUGHLY FROM MOUNT
STERLING TO JUST NORTH OF PIKEVILLE. ADJUSTED POPS TO BETTER REFLECT
AREAS WITH BEST POTENTIAL OF SEEING RAINFALL. ALSO MADE SOME TWEAKS
TO AFTERNOON HIGHS. CONVECTIVE PATTERN IS MAKING AFTERNOON HIGHS A
BIT TRICKY TO FORECAST...AND ESPECIALLY HOURLY TRENDS. BUT IN GENERAL
HIGHS SHOULD BE PRETTY CLOSE TO ADVERTISED LEVELS.
UPDATE ISSUED AT 1103 AM EDT THU JUN 19 2014
MORNING CONVECTION HAS LAID OUT SEVERAL OUTFLOW BOUNDARIES ACROSS THE
NORTHERN PORTIONS OF OUR FORECAST AREA THIS MORNING. BULK OF
CONVECTION SO FAR THIS MORNING APPEARS TO BE RELATED TO THESE
BOUNDARIES. UPPER LEVEL SHORTWAVE OR DISTURBANCE CONTINUES TO RIDE
ACROSS THE REGION DOWN THE EASTERN SIDE OF UPPER MIDWEST RIDGING.
AXIS APPEARS TO BE POSITIONED ROUGHLY FROM ABOUT CVG TO PIT...AND NE
FROM THERE. SLIGHT MID LEVEL HEIGHT FALLS...ABUNDANT MOISTURE AND
SFC BASED INSTABILITY IN COMBINATION WITH AFOREMENTIONED OUTFLOW
BOUNDARIES TO ACT AS TRIGGERS SHOULD BE ALL IT TAKES FOR AFTERNOON
CONVECTION TO FIRE. FOCUS OF ACTIVITY SHOULD BE GENERALLY NORTH OF
THE MOUNTAIN PARKWAY THOUGH SOME SCATTERED SHOWERS AND THUNDERSTORMS
CAN NOT BE RULED OUT ACROSS OUR SOUTHERN MOST COUNTIES...ESPECIALLY
SHOULD ANY OUTFLOWS REACH THAT FAR SOUTH. ANY THUNDERSTORMS THAT DO
DEVELOP COULD DISPLAY SOME STRONG CHARACTERISTICS AND CAN NOT RULE
OUT A SEVERE STORM OR TWO. HWO APPEARS TO HANDLE THE THREAT
ADEQUATELY. COULD ALSO SEE SOME HEAVY RAINERS...ESPECIALLY AS WE GET
INTO FRIDAY AND FRIDAY EVENING. PWATS ARE NEAR CLIMATOLOGICAL HIGHS
AND STORM MOTION LOOKS LOW ENOUGH...5-10KTS. FREEZING LEVELS REMAIN
RELATIVELY HIGH AROUND 14-15K AS WELL. SO WARM WATER PROCESSES COULD
BE A FACTOR AS WELL.
UPDATED FORECAST PACKAGE WITH LATEST THOUGHTS AND TO REFLECT LATEST
TRENDS IN CONVECTION IN OUR NORTH. TWEAKED HIGHS A BIT...BUT MAY
BRING THEM DOWN A BIT MORE IN THE NORTH WITH NEXT UPDATE TO REFLECT
ONGOING CONVECTION. CONCENTRATED POPS IN THE NORTHERN TWO THIRDS OF
OUR CWA. EXPECTATIONS ARE THAT BOUNDARIES COULD TRACK A BIT FARTHER
SOUTH THAN ORIGINALLY ANTICIPATED. HRRR HINTS AT THIS POSSIBILITY AS
WELL. IN GENERAL ACTIVITY SHOULD BE SCATTERED BUT EFFECTIVE POPS MAY
BE HIGHER...CLOSER TO LIKELY...ESPECIALLY IN OUR NORTHERN COUNTIES.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 300 AM EDT THU JUN 19 2014
THE MODELS WERE IN FAIRLY GOOD AGREEMENT REGARDING THE LARGE SCALE
WEATHER PATTERN IN THE SHORT TERM FOR THE EASTERN THIRD OF THE CONUS
AND WITH THE TIMING OF PRECIPITATION FORMATION AND STORM EVOLUTION
TODAY THROUGH TOMORROW. THE GENERAL CONSENSUS WAS FOR A SERIES OF
THUNDERSTORM CLUSTERS TO MOVE OUT OF INDIANA EARLY THIS MORNING AND
ACROSS FAR NORTHERN PORTIONS OF EASTERN KENTUCKY. THAT BEING SAID...A
COMBINATION OF THE LATEST GFS AND SREF MODEL OUTPUT WAS USED TO
FOR THE FIRST 36 HOURS OF THE FORECAST. THE INITIAL GROUP OF STORMS
LOOKS LIKE IT WILL CLIP OUR COUNTIES ALONG AND NORTH OF I-64 EARLY
TODAY. AFTER THAT...A FRONTAL BOUNDARY WITH A WAVE MOVING ALONG IT IS
EXPECTED TO SLOWLY DRIFT SOUTHWARD INTO THE LOWER OHIO VALLEY. THIS
BOUNDARY AND WAVE WILL INTERACT WITH WARM...MOIST...UNSTABLE AIR THAT
IS ALREADY IN PLACE TO SPARK SCATTERED SHOWERS AND STORMS THIS
AFTERNOON AND EVENING. AFTER A DROP OFF IN ACTIVITY OVERNIGHT...THE
FRONT WILL FINALLY BEGIN TO MOVE INTO AND ACROSS THE AREA ON
FRIDAY...ALLOWING THE SHOWERS AND STORMS TO BECOME MORE NUMEROUS AS
STRONG LIFT ALONG THE FRONT BEGINS TO OCCUR. THE ROUNDS OF STORMS WE
SEE TODAY AND FRIDAY COULD PRODUCE LOCALLY HEAVY RAINFALL AND GUSTY
WINDS AND PERHAPS EVEN SOME SMALL HAIL. TEMPERATURES TODAY AND
TOMORROW WILL CONTINUE TO RUN ABOVE NORMAL...WITH HIGHS TODAY TOPPING
OUT IN THE UPPER 80S AND IN THE MID TO UPPER 80S ON FRIDAY. OVERNIGHT
LOWS WILL ONLY BE DROPPING INTO THE MID TO UPPER 60S.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 316 PM EDT THU JUN 19 2014
EASTERN KY WILL FIND ITSELF ON THE BACK EDGE OF A DEAMPLIFIED
RIDGING PATTERN AT THE BEGINNING OF THE PERIOD /12Z SATURDAY/...WITH
A SHORTWAVE PASSING THROUGH THE REGION AND A SURFACE BOUNDARY IN THE
FORM OF A BACKDOOR COLD FRONT CAUSING SHOWERS AND THUNDERSTORMS TO
LINGER...ESPECIALLY ACROSS THE SE PORTION OF THE CWA. THE NAM IS THE
ONLY MODEL AT THIS POINT WHICH DOES NOT PUT PRECIP COVERAGE ACROSS
MUCH OF THE CWA...SO HAVE SLIGHTLY LOWER CONFIDENCE DURING THIS TIME
PERIOD FOR THE MODEL. EXPECT BEST COVERAGE TO BE IN THE
MORNING...THEN TAPERING OFF AS THE SURFACE LOW SLOWLY PUSHES
SOUTHWARD. CHANCES WILL LINGER LONGEST OVER THE SE PORTION OF THE
STATE WITH LINGERING LOW LEVEL MOISTURE AND UPSLOPE FLOW. THE UPPER
LEVEL SHORTWAVE WILL CONTINUE TO SLOWLY SLIDE EASTWARD SATURDAY
NIGHT AND SUNDAY...AS THE OVERALL UPPER FLOW BECOMES SLIGHTLY MORE
ZONAL. THIS WILL ELIMINATE THE BEST PRECIP CHANCES OVERNIGHT
SATURDAY...THOUGH LINGERING MOISTURE AND DAYTIME INSTABILITY COULD
POP UP SOME MORE DIURNALLY DRIVEN SCATTERED SHOWERS AND
THUNDERSTORMS DURING THE DAY SUNDAY. A MORE NORTHERLY FLOW BOTH
SATURDAY AND SUNDAY WILL KEEP DAYTIME TEMPERATURES SLIGHTLY COOLER
THAN PREVIOUS DAYS...IN THE LOW TO MID 80S ACROSS MUCH OF THE CWA.
DIURNALLY DRIVEN SCATTERED SHOWERS AND THUNDERSTORMS COULD BE
POSSIBLE INTO THE DAY MONDAY AS WELL...WHILE WEAK UPPER LEVEL
RIDGING REMAINS OVERHEAD. HOWEVER...BOTH THE GEM AND ECMWF ARE ONLY
SHOWING DEVELOPMENT ACROSS THE FAR SE COUNTIES...WHILE THE GFS IS
SHOWING A VAST AMOUNT OF PRECIP ACROSS MUCH OF KENTUCKY. GIVEN THE
SYNOPTIC SET UP...WOULD CHOSE TO SIDE CLOSER TO THE ECWMF...WITH THE
GFS PULLING IN AN UNREALISTIC AMOUNT OF MOISTURE ACROSS THE REGION.
BY LATE MONDAY...AN UPPER LEVEL LOW IN SOUTH CENTRAL CANADA WILL
BEGIN TO DEEPEN...PULLING A DEEPENING TROUGH INTO THE MISSISSIPPI
RIVER VALLEY OVERNIGHT MONDAY NIGHT. AS THIS LOW SHIFTS
EASTWARD...EXPECT A SURFACE LOW AND BOUNDARY TO IMPACT THE REGION
DURING THE DAY TUESDAY. MODELS AT THIS POINT ARE CONTINUING TO
DISAGREE IN THEIR SOLUTIONS...SO WILL STICK CLOSE TO THE ALLBLEND
FROM THIS POINT FORWARD. AS THIS SYSTEM APPROACHES...SOUTHERLY FLOW
WILL REESTABLISH ITSELF...BRINGING IN A WARMER AND MORE
HUMID/UNSTABLE AIRMASS. SHOWERS AND THUNDERSTORMS COULD BE POSSIBLE
FROM TUESDAY WELL INTO THE DAY WEDNESDAY AS THE SURFACE FRONT
BECOMES MORE WEST TO EAST ORIENTED ACROSS KENTUCKY. A BRIEF BREAK
MIGHT BE FELT SOMETIME EARLY THURSDAY...HOWEVER ANOTHER SHORTWAVE
WILL BE FAST TO BRING YET ANOTHER CHANCE FOR SHOWERS AND
THUNDERSTORMS TO FINISH OUT THE 7 DAY FORECAST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 211 PM EDT THU JUN 19 2014
VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH MOST OF THE FORECAST
PERIOD. MAY HAVE TO CONTEND WITH A FEW THUNDERSTORMS THAT COULD
BRIEFLY PRODUCE IFR VSBYS/MVFR CIGS. BUT THREAT IS NOT WIDESPREAD NOR
WOULD THUNDERSTORMS FREQUENT TERMINALS ENOUGH TO WARRANT ANY TEMPO
GROUPS ATTM. ACTIVITY SHOULD DIE OFF THROUGH THE VERY LATE AFTERNOON
AND EARLY EVENING. AREAS THAT RECEIVE ANY RAIN WILL PROBABLY SEE A
BIT OF FOG DEVELOP OVERNIGHT. BUT KEPT AIRPORT TERMINALS IN FAVORABLE
CONDITIONS OVERNIGHT...MUCH MORE OPTIMISTIC THAN GUIDANCE WHICH SEEMS
TO HAVE LATCHED ONTO MORE WIDESPREAD RAINFALL AND CONSEQUENTLY MORE
PESSIMISTIC NUMBERS. SHOWERS AND THUNDERSTORMS WILL DEVELOP AGAIN
FRIDAY WITH A BIT WIDER COVERAGE LIKELY. WESTERLY WINDS HAVE
DEVELOPED TO BETWEEN 5 AND 10 KTS. THEY WILL SLACKEN TONIGHT BEFORE
INCREASING AGAIN THROUGH THE DAY FRIDAY...AGAIN AROUND 10 KTS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...RAY
SHORT TERM...AR
LONG TERM...JMW
AVIATION...RAY
AREA FORECAST DISCUSSION
NWS JACKSON KY
211 PM EDT THU JUN 19 2014
.UPDATE...
ISSUED AT 211 PM EDT THU JUN 19 2014
ISOLD TO SCATTERED CONVECTION CONTINUES TO FIRE ACROSS PORTIONS OF THE
FORECAST AREA THIS AFTERNOON. SHOWERS AND THUNDERSTORMS DEVELOPING
ALONG SEVERAL OUTFLOW BOUNDARIES LEFT OVER FROM MORNING CONVECTION
WHERE LATE SPRING SUN HAS BEEN STRONG ENOUGH TO DESTABILIZE THE
BOUNDARY LAYER. STRONGEST CONVECTION ATTM IS LOCATED TO THE SOUTH
ALONG THE TN/KY STATE LINE. HOWEVER CLUSTER OF STORMS MOVING THROUGH
CENTRAL KENTUCKY IS PUTTING OUT A FAIRLY CLEAR OUTFLOW BOUNDARY THAT
SHOULD BE MOVING INTO THE WESTERN PORTIONS OF OUR CWA IN A COUPLE
HOURS. THAT MAY BE ONE OF THE MAIN FOCUSES OF ACTIVITY THROUGH THE
REMAINDER OF THE AFTERNOON. ANOTHER PREDOMINANT BOUNDARY THAT APPEARS
PRIMED FOR SOME REDEVELOPMENT IS CURRENTLY DRAPED ACROSS THE
NORTHEASTERN THIRD OF OUR CWA...STRETCHING ROUGHLY FROM MOUNT
STERLING TO JUST NORTH OF PIKEVILLE. ADJUSTED POPS TO BETTER REFLECT
AREAS WITH BEST POTENTIAL OF SEEING RAINFALL. ALSO MADE SOME TWEAKS
TO AFTERNOON HIGHS. CONVECTIVE PATTERN IS MAKING AFTERNOON HIGHS A
BIT TRICKY TO FORECAST...AND ESPECIALLY HOURLY TRENDS. BUT IN GENERAL
HIGHS SHOULD BE PRETTY CLOSE TO ADVERTISED LEVELS.
UPDATE ISSUED AT 1103 AM EDT THU JUN 19 2014
MORNING CONVECTION HAS LAID OUT SEVERAL OUTFLOW BOUNDARIES ACROSS THE
NORTHERN PORTIONS OF OUR FORECAST AREA THIS MORNING. BULK OF
CONVECTION SO FAR THIS MORNING APPEARS TO BE RELATED TO THESE
BOUNDARIES. UPPER LEVEL SHORTWAVE OR DISTURBANCE CONTINUES TO RIDE
ACROSS THE REGION DOWN THE EASTERN SIDE OF UPPER MIDWEST RIDGING.
AXIS APPEARS TO BE POSITIONED ROUGHLY FROM ABOUT CVG TO PIT...AND NE
FROM THERE. SLIGHT MID LEVEL HEIGHT FALLS...ABUNDANT MOISTURE AND
SFC BASED INSTABILITY IN COMBINATION WITH AFOREMENTIONED OUTFLOW
BOUNDARIES TO ACT AS TRIGGERS SHOULD BE ALL IT TAKES FOR AFTERNOON
CONVECTION TO FIRE. FOCUS OF ACTIVITY SHOULD BE GENERALLY NORTH OF
THE MOUNTAIN PARKWAY THOUGH SOME SCATTERED SHOWERS AND THUNDERSTORMS
CAN NOT BE RULED OUT ACROSS OUR SOUTHERN MOST COUNTIES...ESPECIALLY
SHOULD ANY OUTFLOWS REACH THAT FAR SOUTH. ANY THUNDERSTORMS THAT DO
DEVELOP COULD DISPLAY SOME STRONG CHARACTERISTICS AND CAN NOT RULE
OUT A SEVERE STORM OR TWO. HWO APPEARS TO HANDLE THE THREAT
ADEQUATELY. COULD ALSO SEE SOME HEAVY RAINERS...ESPECIALLY AS WE GET
INTO FRIDAY AND FRIDAY EVENING. PWATS ARE NEAR CLIMATOLOGICAL HIGHS
AND STORM MOTION LOOKS LOW ENOUGH...5-10KTS. FREEZING LEVELS REMAIN
RELATIVELY HIGH AROUND 14-15K AS WELL. SO WARM WATER PROCESSES COULD
BE A FACTOR AS WELL.
UPDATED FORECAST PACKAGE WITH LATEST THOUGHTS AND TO REFLECT LATEST
TRENDS IN CONVECTION IN OUR NORTH. TWEAKED HIGHS A BIT...BUT MAY
BRING THEM DOWN A BIT MORE IN THE NORTH WITH NEXT UPDATE TO REFLECT
ONGOING CONVECTION. CONCENTRATED POPS IN THE NORTHERN TWO THIRDS OF
OUR CWA. EXPECTATIONS ARE THAT BOUNDARIES COULD TRACK A BIT FARTHER
SOUTH THAN ORIGINALLY ANTICIPATED. HRRR HINTS AT THIS POSSIBILITY AS
WELL. IN GENERAL ACTIVITY SHOULD BE SCATTERED BUT EFFECTIVE POPS MAY
BE HIGHER...CLOSER TO LIKELY...ESPECIALLY IN OUR NORTHERN COUNTIES.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 300 AM EDT THU JUN 19 2014
THE MODELS WERE IN FAIRLY GOOD AGREEMENT REGARDING THE LARGE SCALE
WEATHER PATTERN IN THE SHORT TERM FOR THE EASTERN THIRD OF THE CONUS
AND WITH THE TIMING OF PRECIPITATION FORMATION AND STORM EVOLUTION
TODAY THROUGH TOMORROW. THE GENERAL CONSENSUS WAS FOR A SERIES OF
THUNDERSTORM CLUSTERS TO MOVE OUT OF INDIANA EARLY THIS MORNING AND
ACROSS FAR NORTHERN PORTIONS OF EASTERN KENTUCKY. THAT BEING SAID...A
COMBINATION OF THE LATEST GFS AND SREF MODEL OUTPUT WAS USED TO
FOR THE FIRST 36 HOURS OF THE FORECAST. THE INITIAL GROUP OF STORMS
LOOKS LIKE IT WILL CLIP OUR COUNTIES ALONG AND NORTH OF I-64 EARLY
TODAY. AFTER THAT...A FRONTAL BOUNDARY WITH A WAVE MOVING ALONG IT IS
EXPECTED TO SLOWLY DRIFT SOUTHWARD INTO THE LOWER OHIO VALLEY. THIS
BOUNDARY AND WAVE WILL INTERACT WITH WARM...MOIST...UNSTABLE AIR THAT
IS ALREADY IN PLACE TO SPARK SCATTERED SHOWERS AND STORMS THIS
AFTERNOON AND EVENING. AFTER A DROP OFF IN ACTIVITY OVERNIGHT...THE
FRONT WILL FINALLY BEGIN TO MOVE INTO AND ACROSS THE AREA ON
FRIDAY...ALLOWING THE SHOWERS AND STORMS TO BECOME MORE NUMEROUS AS
STRONG LIFT ALONG THE FRONT BEGINS TO OCCUR. THE ROUNDS OF STORMS WE
SEE TODAY AND FRIDAY COULD PRODUCE LOCALLY HEAVY RAINFALL AND GUSTY
WINDS AND PERHAPS EVEN SOME SMALL HAIL. TEMPERATURES TODAY AND
TOMORROW WILL CONTINUE TO RUN ABOVE NORMAL...WITH HIGHS TODAY TOPPING
OUT IN THE UPPER 80S AND IN THE MID TO UPPER 80S ON FRIDAY. OVERNIGHT
LOWS WILL ONLY BE DROPPING INTO THE MID TO UPPER 60S.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 415 AM EDT THU JUN 19 2014
EARLY IN THE PERIOD...A MID LEVEL WAVE MOVING THROUGH THE OHIO VALLEY
AND ANOTHER MID LEVEL SHORTWAVE ROTATING AROUND A DEEP CLOSED LOW
OVER THE CANADIAN MARITIMES WILL SEND A BACKDOOR COLD FRONT SOUTH AND
SOUTHWEST INTO AND POSSIBLY SOUTH OF THE CWA TO END THE WEEKEND. THIS
WILL OFFER A SLIGHT REPRIEVE FROM THE RECENT HEAT...ALTHOUGH THE
POST FRONTAL AIR MASS SHOULD OFFER SLIGHTLY LOWER DEW POINTS TO END
THE WEEKEND. THIS REPRIEVE SHOULD BE BRIEF...HOWEVER.
THE MID LEVEL WAVE WORKING ACROSS THE OH VALLEY SHOULD COMBINE WITH
THE SAGGING BOUNDARY TO BRING GOOD CHANCES FOR CONVECTION ON FRIDAY
NIGHT AND LINGERING INTO THE DAY ON SATURDAY...ESPECIALLY IN THE
SOUTHEAST. THE 0Z GFS IS LIKELY SUFFERING FROM SOME CONVECTIVE
FEEDBACK LEADING TO THE HIGH GFS QPF NORTH OF THE MTN PARKWAY EARLY
IN THE PERIOD ON FRIDAY NIGHT INTO EARLY ON SATURDAY. PW IS EXPECTED
TO CLIMB TO NEAR 1.8 INCHES...OR GREATER THAN THE 75TH PERCENTILE AND
STEERING WINDS WILL BE RELATIVELY WEAK WITH SOME POTENTIAL FOR
TRAINING...SO LOCALIZED TOTALS OVER 2 INCHES ARE CERTAINLY POSSIBLE
WHICH MIGHT LEAD TO SOME HYDRO ISSUES. HOWEVER...CONFIDENCE IN THIS
SCENARIO AND PLACEMENT IS LOW AND WE HAVE CONTINUED TO MENTION THE
POTENTIAL IN THE HWO.
MID LEVEL SHORTWAVE RIDGING/HEIGHT RISES SHOULD LEAD TO CONVECTION
BECOMING MORE DIURNALLY DRIVEN FOR SUNDAY INTO MONDAY. HOWEVER...BUT
LATE MONDAY INTO MONDAY NIGHT...THE RIDGING WILL SHIFT EAST AND
RETURN LOW SHOULD ALREADY BE RETURNING A MORE HUMID AIR MASS NORTH IN
ADVANCE OF THE NEXT SHORTWAVE TROUGH AND ASSOCIATED SFC SYSTEM APPROACHING
THE MID MS AND LOWER OH VALLEY REGION. WITH THIS FROM MONDAY NIGHT
INTO THE END OF THE PERIOD...ISOLATED TO SCATTERED CONVECTION CANNOT
BE RULED OUT AT ANY POINT....THOUGH AFTERNOON AND EVENING WILL BE
MOST FAVORED CLIMATOLOGICALLY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 211 PM EDT THU JUN 19 2014
VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH MOST OF THE FORECAST
PERIOD. MAY HAVE TO CONTEND WITH A FEW THUNDERSTORMS THAT COULD
BRIEFLY PRODUCE IFR VSBYS/MVFR CIGS. BUT THREAT IS NOT WIDESPREAD NOR
WOULD THUNDERSTORMS FREQUENT TERMINALS ENOUGH TO WARRANT ANY TEMPO
GROUPS ATTM. ACTIVITY SHOULD DIE OFF THROUGH THE VERY LATE AFTERNOON
AND EARLY EVENING. AREAS THAT RECEIVE ANY RAIN WILL PROBABLY SEE A
BIT OF FOG DEVELOP OVERNIGHT. BUT KEPT AIRPORT TERMINALS IN FAVORABLE
CONDITIONS OVERNIGHT...MUCH MORE OPTIMISTIC THAN GUIDANCE WHICH SEEMS
TO HAVE LATCHED ONTO MORE WIDESPREAD RAINFALL AND CONSEQUENTLY MORE
PESSIMISTIC NUMBERS. SHOWERS AND THUNDERSTORMS WILL DEVELOP AGAIN
FRIDAY WITH A BIT WIDER COVERAGE LIKELY. WESTERLY WINDS HAVE
DEVELOPED TO BETWEEN 5 AND 10 KTS. THEY WILL SLACKEN TONIGHT BEFORE
INCREASING AGAIN THROUGH THE DAY FRIDAY...AGAIN AROUND 10 KTS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...RAY
SHORT TERM...AR
LONG TERM...JP
AVIATION...RAY
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
130 PM EDT Thu Jun 19 2014
...Updated Aviation Discussion...
...Forecast Update...
Issued at 1231 PM EDT Thu Jun 19 2014
Another update to account for the convection that has developed
across central and far southern KY. Utilizing the experimental CIMSS
NearCast model, the axis of greater instability and moisture will
continue to flow over much of the forecast area through this
evening. Other hi-res models are continuing to hone in on southern
IN and northern KY through the Bluegrass region for the primary
focus for diurnally-driven convection. Otherwise, the forecast
remains on track.
Issued at 941 AM EDT Thu Jun 19 2014
Just did a minor update primarily to the PoPs and sky cover to
include HRRR model guidance (for PoPs) as it seems to have a good
handle on where the focus of convection will be. We`ll have a bit of
a lull through much of the rest of this morning but look for
scattered thunderstorms across much of the forecast area this
afternoon as the sun heats the surface up. The greatest coverage
should be in southern Indiana and northern Kentucky into the
Bluegrass region.
Issued at 635 AM EDT Thu Jun 19 2014
A few showers have popped up this morning over the northern
Bluegrass. These showers have developed along the remnants of the
outflow boundary from last night`s convection. Expect to continue to
see storm development along this boundary today. Just made some
small changes to the pops this morning and trended the forecast
toward current observations.
.SHORT TERM (Now through Friday)...
Issued at 310 AM EDT Thu Jun 19 2014
The storms that prompted the Severe Thunderstorm Watch earlier have
significantly weakened this morning. In addition, these storms look
to stay north of the forecast area. Thus, the Severe Thunderstorm
Watch has been dropped. For early this morning, it is not out of the
question that a shower or possibly thunderstorm will pop up across
portions of north central KY, but they should be fairly isolated.
Through the remainder of the day, scattered showers and
thunderstorms are expected to develop late this morning into the
afternoon hours as we warm up. The best chance for storms looks to
be across portions of southern IN and north central KY as the
boundary from tonight`s convection as well as a boundary from
convection yesterday evening sag southward across the region.
Further to the south and west, there will be less of a focusing
mechanism, but some storm development is certainly possible in the
unstable atmosphere this afternoon.
There may be a lull in activity this evening, though given the
multiple boundaries across the area and convection possibly moving
in from the west, a few showers or storms may hang around. On Friday
a weak cold front will approach the area from the northwest. Ahead
of this boundary, precipitable water values will rise to near 2
inches. Given plenty of instability, moisture, and the approaching
boundary, storm chances will be better on Friday than today. Given
the high PWAT values, these storms have the potential to produce
torrential rainfall.
As for temperatures, they will remain hot and muggy. Highs will be
in the upper 80s to lower 90s, though today will likely be a degree
or two cooler than yesterday and tomorrow should be a degree or two
cooler than today. Lows tomorrow morning will be in the lower 70s.
.LONG TERM (Friday Night through Wednesday)...
Issued at 252 AM EDT Thu Jun 19 2014
A weak surface low will cross the Ohio Valley Friday night/Saturday
morning along with some weak upper level vorticity and PWATs pooling
near two inches. So, will continue with scattered PoPs for Friday
night and Saturday.
Saturday night through Monday night moisture will decrease to near
normal for mid/late June and forcing at the surface and aloft will
be weak. Can`t rule out some spotty summertime convection but will
keep PoPs very low.
Will probably see highs mainly in the 80s over the weekend as upper
ridge flattens and 850 temps drop to around 17C. Temps may inch up
a tick or two on Monday as we get into southwest low level flow
ahead of a weak cool front extending from the Great Lakes to the Big
Bend. Monday will probably be the warmest day of the long term.
Tuesday and Tuesday night that weak front will push into the area
and give us our best chance of thunderstorms in the long term.
Winds could get a little gusty Tuesday afternoon...maybe in the
20-25 mph range.
Wednesday is a question mark as model solutions diverge
significantly. For now will lean more toward the Euro`s slower
passage of the weak front, as is typical for this time of yer, and
will continue with a small PoP in the forecast.
Afternoon highs should settle back into the 80s for Tuesday and
Wednesday.
&&
.AVIATION (18Z TAF Update)...
Issued at 125 PM EDT Thu Jun 19 2014
Thunderstorms are popping up across portions of central KY this
afternoon in a very broken line stretching from in between LEX to
BWG. There will be increased chances for scattered thunderstorm
activity as the day wears on and therefore continued VCTS mention
for all three terminals. Due to the pulse nature of the storms, have
foregone any tempo groups, especially considering the uncertainty of
whether or not convection will directly impact the terminals. Will
update with an amendment as necessary.
Winds will be at their strongest through this afternoon before dying
off after sunset tonight. The general direction will vary from out
of the W to SW throughout much of the TAF period, right around 10
knots or so through this evening then dropping below 5 knots
overnight. Any storm that comes within range of the terminals could
cause locally higher gusts and quick wind shifts.
For the pre-dawn hours on Friday, have continued mention of
haze/light fog for LEX and BWG but given the cloud cover expected to
linger through the overnight hours, don`t have too much confidence
of this panning out, especially if rain doesn`t fall in the terminal
areas today. Tomorrow afternoon will see increased chances for
thunderstorms across central KY, more so than today as a front
approaches from the north.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Update.........lg
Short Term.....EER
Long Term......13
Aviation.......lg
AREA FORECAST DISCUSSION
NWS JACKSON KY
1103 AM EDT THU JUN 19 2014
.UPDATE...
ISSUED AT 1103 AM EDT THU JUN 19 2014
MORNING CONVECTION HAS LAID OUT SEVERAL OUTFLOW BOUNDARIES ACROSS THE
NORTHERN PORTIONS OF OUR FORECAST AREA THIS MORNING. BULK OF
CONVECTION SO FAR THIS MORNING APPEARS TO BE RELATED TO THESE
BOUNDARIES. UPPER LEVEL SHORTWAVE OR DISTURBANCE CONTINUES TO RIDE
ACROSS THE REGION DOWN THE EASTERN SIDE OF UPPER MIDWEST RIDGING.
AXIS APPEARS TO BE POSITIONED ROUGHLY FROM ABOUT CVG TO PIT...AND NE
FROM THERE. SLIGHT MID LEVEL HEIGHT FALLS...ABUNDANT MOISTURE AND
SFC BASED INSTABILITY IN COMBINATION WITH AFOREMENTIONED OUTFLOW
BOUNDARIES TO ACT AS TRIGGERS SHOULD BE ALL IT TAKES FOR AFTERNOON
CONVECTION TO FIRE. FOCUS OF ACTIVITY SHOULD BE GENERALLY NORTH OF
THE MOUNTAIN PARKWAY THOUGH SOME SCATTERED SHOWERS AND THUNDERSTORMS
CAN NOT BE RULED OUT ACROSS OUR SOUTHERN MOST COUNTIES...ESPECIALLY
SHOULD ANY OUTFLOWS REACH THAT FAR SOUTH. ANY THUNDERSTORMS THAT DO
DEVELOP COULD DISPLAY SOME STRONG CHARACTERISTICS AND CAN NOT RULE
OUT A SEVERE STORM OR TWO. HWO APPEARS TO HANDLE THE THREAT
ADEQUATELY. COULD ALSO SEE SOME HEAVY RAINERS...ESPECIALLY AS WE GET
INTO FRIDAY AND FRIDAY EVENING. PWATS ARE NEAR CLIMATOLOGICAL HIGHS
AND STORM MOTION LOOKS LOW ENOUGH...5-10KTS. FREEZING LEVELS REMAIN
RELATIVELY HIGH AROUND 14-15K AS WELL. SO WARM WATER PROCESSES COULD
BE A FACTOR AS WELL.
UPDATED FORECAST PACKAGE WITH LATEST THOUGHTS AND TO REFLECT LATEST
TRENDS IN CONVECTION IN OUR NORTH. TWEAKED HIGHS A BIT...BUT MAY
BRING THEM DOWN A BIT MORE IN THE NORTH WITH NEXT UPDATE TO REFLECT
ONGOING CONVECTION. CONCENTRATED POPS IN THE NORTHERN TWO THIRDS OF
OUR CWA. EXPECTATIONS ARE THAT BOUNDARIES COULD TRACK A BIT FARTHER
SOUTH THAN ORIGINALLY ANTICIPATED. HRRR HINTS AT THIS POSSIBILITY AS
WELL. IN GENERAL ACTIVITY SHOULD BE SCATTERED BUT EFFECTIVE POPS MAY
BE HIGHER...CLOSER TO LIKELY...ESPECIALLY IN OUR NORTHERN COUNTIES.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 300 AM EDT THU JUN 19 2014
THE MODELS WERE IN FAIRLY GOOD AGREEMENT REGARDING THE LARGE SCALE
WEATHER PATTERN IN THE SHORT TERM FOR THE EASTERN THIRD OF THE CONUS
AND WITH THE TIMING OF PRECIPITATION FORMATION AND STORM EVOLUTION
TODAY THROUGH TOMORROW. THE GENERAL CONSENSUS WAS FOR A SERIES OF
THUNDERSTORM CLUSTERS TO MOVE OUT OF INDIANA EARLY THIS MORNING AND
ACROSS FAR NORTHERN PORTIONS OF EASTERN KENTUCKY. THAT BEING SAID...A
COMBINATION OF THE LATEST GFS AND SREF MODEL OUTPUT WAS USED TO
FOR THE FIRST 36 HOURS OF THE FORECAST. THE INITIAL GROUP OF STORMS
LOOKS LIKE IT WILL CLIP OUR COUNTIES ALONG AND NORTH OF I-64 EARLY
TODAY. AFTER THAT...A FRONTAL BOUNDARY WITH A WAVE MOVING ALONG IT IS
EXPECTED TO SLOWLY DRIFT SOUTHWARD INTO THE LOWER OHIO VALLEY. THIS
BOUNDARY AND WAVE WILL INTERACT WITH WARM...MOIST...UNSTABLE AIR THAT
IS ALREADY IN PLACE TO SPARK SCATTERED SHOWERS AND STORMS THIS
AFTERNOON AND EVENING. AFTER A DROP OFF IN ACTIVITY OVERNIGHT...THE
FRONT WILL FINALLY BEGIN TO MOVE INTO AND ACROSS THE AREA ON
FRIDAY...ALLOWING THE SHOWERS AND STORMS TO BECOME MORE NUMEROUS AS
STRONG LIFT ALONG THE FRONT BEGINS TO OCCUR. THE ROUNDS OF STORMS WE
SEE TODAY AND FRIDAY COULD PRODUCE LOCALLY HEAVY RAINFALL AND GUSTY
WINDS AND PERHAPS EVEN SOME SMALL HAIL. TEMPERATURES TODAY AND
TOMORROW WILL CONTINUE TO RUN ABOVE NORMAL...WITH HIGHS TODAY TOPPING
OUT IN THE UPPER 80S AND IN THE MID TO UPPER 80S ON FRIDAY. OVERNIGHT
LOWS WILL ONLY BE DROPPING INTO THE MID TO UPPER 60S.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 415 AM EDT THU JUN 19 2014
EARLY IN THE PERIOD...A MID LEVEL WAVE MOVING THROUGH THE OHIO VALLEY
AND ANOTHER MID LEVEL SHORTWAVE ROTATING AROUND A DEEP CLOSED LOW
OVER THE CANADIAN MARITIMES WILL SEND A BACKDOOR COLD FRONT SOUTH AND
SOUTHWEST INTO AND POSSIBLY SOUTH OF THE CWA TO END THE WEEKEND. THIS
WILL OFFER A SLIGHT REPRIEVE FROM THE RECENT HEAT...ALTHOUGH THE
POST FRONTAL AIRMASS SHOULD OFFER SLIGHTLY LOWER DEWPOINTS TO END
THE WEEKEND. THIS REPRIEVE SHOULD BE BRIEF...HOWEVER.
THE MID LEVEL WAVE WORKING ACROSS THE OH VALLEY SHOULD COMBINE WITH
THE SAGGING BOUNDARY TO BRING GOOD CHANCES FOR CONVECTION ON FRIDAY
NIGHT AND LINGERING INTO THE DAY ON SATURDAY...ESPECIALLY IN THE
SOUTHEAST. THE 0Z GFS IS LIKELY SUFFERING FROM SOME CONVECTIVE
FEEDBACK LEADING TO THE HIGH GFS QPF NORTH OF THE MTN PARKWAY EARLY
IN THE PERIOD ON FRIDAY NIGHT INTO EARLY ON SATURDAY. PW IS EXPECTED
TO CLIMB TO NEAR 1.8 INCHES...OR GREATER THAN THE 75TH PERCENTILE AND
STEERING WINDS WILL BE RELATIVELY WEAK WITH SOME POTENTIAL FOR
TRAINING...SO LOCALIZED TOTALS OVER 2 INCHES ARE CERTAINLY POSSIBLE
WHICH MIGHT LEAD TO SOME HYDRO ISSUES. HOWEVER...CONFIDENCE IN THIS
SCENARIO AND PLACEMENT IS LOW AND WE HAVE CONTINUED TO MENTION THE
POTENTIAL IN THE HWO.
MID LEVEL SHORTWAVE RIDGING/HEIGHT RISES SHOULD LEAD TO CONVECTION
BECOMING MORE DIURNALLY DRIVEN FOR SUNDAY INTO MONDAY. HOWEVER...BUT
LATE MONDAY INTO MONDAY NIGHT...THE RIDGING WILL SHIFT EAST AND
RETURN LOW SHOULD ALREADY BE RETURNING A MORE HUMID AIRMASS NORTH IN
ADVANCE OF THE NEXT SHORTWAVE TROUGH AND ASSOCIATED SFC SYSTEM APPROACHING
THE MID MS AND LOWER OH VALLEY REGION. WITH THIS FROM MONDAY NIGHT
INTO THE END OF THE PERIOD...ISOLATED TO SCATTERED CONVECTION CANNOT
BE RULED OUT AT ANY POINT....THOUGH AFTERNOON AND EVENING WILL BE
MOST FAVORED CLIMATOLOGICALLY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 800 AM EDT THU JUN 19 2014
IFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH MOST OF THE PERIOD.
A FEW STORMS WILL MOVE ACROSS THE NORTHERNMOST COUNTIES THROUGH 14Z
TO 15Z...BUT SHOULD REMAIN NORTH OF JKL AND SJS AND THE OTHER TAF
SITES. AN APPROACHING COLD FRONT AND A PASSING DISTURBANCE WILL BRING
REDEVELOPMENT OF MORE SHOWERS AND STORMS BETWEEN 15 AND 17Z TODAY.
THE ACTIVITY SHOULD MAINLY FOCUS NORTH OF THE HAL ROGERS PARKWAY AND
HIGHWAY 80 CORRIDOR...AFFECTING JKL AND SJS MOSTLY DURING THE TAF
PERIOD. LOZ AND SME WILL ISOLATED TO SCATTERED SHOWERS AND STORMS
DURING THE PERIOD BEGINNING AROUND 16Z TODAY. CIGS OF 3.5 TO 4K WILL
BE COMMON WITH ANY SHOWERS AND STORMS THAT AFFECT THE TAF SITES
TODAY...AND ANY DIRECT HIT WILL LEAD TO BRIEF PERIODS OF IFR.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...RAY
SHORT TERM...AR
LONG TERM...JP
AVIATION...JP
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
945 AM EDT Thu Jun 19 2014
...Forecast Update...
Issued at 941 AM EDT Thu Jun 19 2014
Just did a minor update primarily to the PoPs and sky cover to
include HRRR model guidance (for PoPs) as it seems to have a good
handle on where the focus of convection will be. We`ll have a bit of
a lull through much of the rest of this morning but look for
scattered thunderstorms across much of the forecast area this
afternoon as the sun heats the surface up. The greatest coverage
should be in southern Indiana and northern Kentucky into the
Bluegrass region.
Issued at 635 AM EDT Thu Jun 19 2014
A few showers have popped up this morning over the northern
Bluegrass. These showers have developed along the remnants of the
outflow boundary from last night`s convection. Expect to continue to
see storm development along this boundary today. Just made some
small changes to the pops this morning and trended the forecast
toward current observations.
.SHORT TERM (Now through Friday)...
Issued at 310 AM EDT Thu Jun 19 2014
The storms that prompted the Severe Thunderstorm Watch earlier have
significantly weakened this morning. In addition, these storms look
to stay north of the forecast area. Thus, the Severe Thunderstorm
Watch has been dropped. For early this morning, it is not out of the
question that a shower or possibly thunderstorm will pop up across
portions of north central KY, but they should be fairly isolated.
Through the remainder of the day, scattered showers and
thunderstorms are expected to develop late this morning into the
afternoon hours as we warm up. The best chance for storms looks to
be across portions of southern IN and north central KY as the
boundary from tonight`s convection as well as a boundary from
convection yesterday evening sag southward across the region.
Further to the south and west, there will be less of a focusing
mechanism, but some storm development is certainly possible in the
unstable atmosphere this afternoon.
There may be a lull in activity this evening, though given the
multiple boundaries across the area and convection possibly moving
in from the west, a few showers or storms may hang around. On Friday
a weak cold front will approach the area from the northwest. Ahead
of this boundary, precipitable water values will rise to near 2
inches. Given plenty of instability, moisture, and the approaching
boundary, storm chances will be better on Friday than today. Given
the high PWAT values, these storms have the potential to produce
torrential rainfall.
As for temperatures, they will remain hot and muggy. Highs will be
in the upper 80s to lower 90s, though today will likely be a degree
or two cooler than yesterday and tomorrow should be a degree or two
cooler than today. Lows tomorrow morning will be in the lower 70s.
.LONG TERM (Friday Night through Wednesday)...
Issued at 252 AM EDT Thu Jun 19 2014
A weak surface low will cross the Ohio Valley Friday night/Saturday
morning along with some weak upper level vorticity and PWATs pooling
near two inches. So, will continue with scattered PoPs for Friday
night and Saturday.
Saturday night through Monday night moisture will decrease to near
normal for mid/late June and forcing at the surface and aloft will
be weak. Can`t rule out some spotty summertime convection but will
keep PoPs very low.
Will probably see highs mainly in the 80s over the weekend as upper
ridge flattens and 850 temps drop to around 17C. Temps may inch up
a tick or two on Monday as we get into southwest low level flow
ahead of a weak cool front extending from the Great Lakes to the Big
Bend. Monday will probably be the warmest day of the long term.
Tuesday and Tuesday night that weak front will push into the area
and give us our best chance of thunderstorms in the long term.
Winds could get a little gusty Tuesday afternoon...maybe in the
20-25 mph range.
Wednesday is a question mark as model solutions diverge
significantly. For now will lean more toward the Euro`s slower
passage of the weak front, as is typical for this time of yer, and
will continue with a small PoP in the forecast.
Afternoon highs should settle back into the 80s for Tuesday and
Wednesday.
&&
.AVIATION (12Z TAF Update)...
Issued at 641 AM EDT Thu Jun 19 2014
Showers have begun to pop up this morning northeast of LEX along a
boundary leftover from last night`s convection. Though some showers
have already developed, the best chance for storms to affect any of
the terminals still looks to be this afternoon. Therefore have kept
the VCTS to between 18-02Z. However, a shower or two before that is
not out of the question. Expect storms to diminish this evening and
thus have dried out the forecast after 00-02Z. Some light fog looks
possible at LEX and BWG tomorrow morning as moisture streams in
ahead of a cold front. Winds throughout the period will be out of the
SSW to SW.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Update.........lg
Short Term.....EER
Long Term......13
Aviation.......EER
AREA FORECAST DISCUSSION
NWS JACKSON KY
131 AM EDT THU JUN 19 2014
.UPDATE...
ISSUED AT 1027 PM EDT WED JUN 18 2014
A FEW TINY SHOWERS DEVELOPED THIS EVENING ACROSS MORGAN AND ELLIOT
COUNTIES. THESE HAVE ALREADY DISSIPATED LEAVING EASTERN KENTUCKY DRY
FOR THE TIME BEING. THE LINE OF SHOWERS AND STORMS TO THE NORTHWEST
EARLIER THIS EVENING HAVE SLID BY TO THE NORTH AND STAYED WELL AWAY
FROM EASTERN KENTUCKY. THUS...IT LOOKS LIKE A GOOD DRY PERIOD CAN BE
EXPECTED THROUGH THE OVERNIGHT HOURS. MORE ACTIVITY IS NOTED ACROSS
NORTHERN INDIANA/ILLINOIS...AND THIS MAY WORK SOUTHWARD TOWARDS OUR
NECK OF THE WOODS AROUND OR SHORTLY AFTER DAYBREAK. HOWEVER...THIS
ACTIVITY IS ALREADY STARTING OFF FARTHER NORTH THAN THE ACTIVITY
EARLIER THIS EVENING...SO SOME QUESTION EXISTS AS TO WHETHER OR NOT
IT WILL EVEN MAKE IT HERE. WITH THAT IN MIND...HAVE DOWNGRADED POPS A
BIT INTO THE MORNING HOURS ON THURSDAY. CHANCES ARE CERTAINLY BETTER
THE FARTHER NORTH YOU GO. THE LATEST HRRR HAS BACKED OFF ON
CONVECTION TOMORROW MORNING AND BETTER CHANCES MAY HOLD OFF UNTIL
BETTER INSTABILITY DEVELOPS IN THE AFTERNOON.
UPDATE ISSUED AT 722 PM EDT WED JUN 18 2014
UPDATED A BIT EARLIER TO REMOVE THUNDER CHANCES FOR THE EVENING AS WE
HAVE STABILIZED QUITE WELL IN THE WAKE OF THE EARLIER AFTERNOON
SHOWERS AND STORMS. STILL WATCHING SHOWERS AND STORMS AS THEY PUSH
ACROSS CENTRAL INDIANA AND WESTERN OHIO. SOME OF THESE COULD THREATEN
OUR NORTHERN AREAS BY LATE EVENING OR OVERNIGHT...BUT AT THIS
TIME...LATEST MODEL GUIDANCE KEEPS THIS ACTIVITY OUT OF OUR AREA
TONIGHT. BETTER THREAT WILL ARRIVE FROM THE NORTH TOWARDS DAYBREAK.
LIMITED ANY THUNDER CHANCES LATE TONIGHT TO MAINLY OUR NORTHERN AREAS
WHERE THE GREATEST THREAT RESIDES.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 400 PM EDT WED JUN 18 2014
19Z SFC ANALYSIS SHOWS WEAK HIGH PRESSURE RETREATING SOUTH OF THE
AREA WHILE AN ACTIVE QUASI-STATIONARY BOUNDARY IS FOUND LYING WEST
TO EAST THROUGH THE NORTHERN OHIO VALLEY. TODAY/S ROUND OF MCS
ACTIVITY IS ROLLING EAST ALONG THIS BOUNDARY WELL TO THE NORTH OF
KENTUCKY. A COUPLE OF STRONG STORMS DID DEVELOP OVER FAR EAST
KENTUCKY EARLIER IN THE AFTERNOON AND KICKED OFF A FEW OUTFLOW
BOUNDARIES...BUT THESE SECONDARY STORMS WERE NOT ABLE TO SUSTAIN
THEMSELVES. PERHAPS THAT WAS DUE TO SOME MID LEVEL WARMING NOTED IN
THE NAM12 SOUNDINGS FOR THE AFTERNOON. REGARDLESS...A SMALL RISK FOR
UNORGANIZED STORMS REMAIN FOR THE REST OF THE AFTERNOON AND INTO THE
FIRST PART OF THE EVENING...WHILE MOST LOCATIONS WILL BE SPARED.
THIS LEAVES JUST VERY WARM AND HUMID WEATHER WITH TEMPERATURES
TOPPING OUT IN THE UPPER 80S AND LOWER 90S WHILE DEWPOINTS ARE IN
THE MIDDLE AND UPPER 60S. TO TOP IT OFF...EVEN THE WINDS HAVE BEEN
OF LITTLE RELIEF...FOR THOSE THAT MISSED OUT ON THE STORMS...MOSTLY
JUST LIGHT FROM THE SOUTHWEST.
THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM PORTION
OF THE FORECAST...FOR WHAT IT IS WORTH. THE SOUTHEAST RIDGE...WEAK AS
IT IS...WILL BE SHUNTED SOUTH LATER TONIGHT IN RESPONSE TO A TROUGH
AND ITS ENERGY PASSING THROUGH THE EASTERN OHIO VALLEY. THE RIDGE
FURTHER FADES THROUGH THE DAY THURSDAY AND INTO THURSDAY NIGHT. THE
REAL MODEL CHALLENGES REVOLVE AROUND THE WAVY BOUNDARY TO THE NORTH
OF KENTUCKY AND INDICATIONS THAT IT WILL CURL SOUTH TO THIS PART
OF THE STATE ON THURSDAY INTO FRIDAY. THIS WILL SEND THE PREFERRED
MCS TRACK CLOSE TO OUR AREA AND LIKELY SET THE STAGE FOR A WET END
TO THE WORK WEEK. GIVEN THE SMALLER SCALES THAT WILL BE
DETERMINATIVE FOR THE ACTUAL MOVEMENT AND EXTENT OF SUCH ACTIVITY
HAVE LEANED MORE TOWARD THE NAM12 THAN THE OTHER MODELS...THOUGH
CONFIDENCE IS LOW IN ANY SPECIFICS GIVEN THE NATURE OF SUCH LATE
SPRING/EARLY SUMMER MCS/QUASI-STATIONARY BOUNDARY EVENTS.
SENSIBLE WEATHER WILL FEATURE AN EARLY DIE OUT OF PINHEAD CONVECTION
THIS EVENING FOLLOWED BY A MUGGY AND WARM NIGHT. MORE ORGANIZED
CONVECTION IS EXPECTED TO BE ONGOING THROUGH THE NIGHT FOR PARTS OF
OHIO WITH A GOOD POTENTIAL TO FOLLOW THE LOWERING HEIGHTS INTO
NORTHERN PARTS OF EAST KENTUCKY TOWARD DAWN. THE SOUPY ENVIRONMENT
SHOULD THEN SUPPORT AIR MASS...AND BETTER ORGANIZED...STORM
DEVELOPMENT DURING THE DAY THURSDAY WITH THE POTENTIAL LINGERING
WELL INTO THE NIGHT GIVEN THE BOUNDARY RIGHT ON OUR NORTHEAST
BORDER. WILL CONTINUE MEDIUM POP CHANCES THROUGH THE PERIOD FOR MUCH
OF THE AREA FROM NEAR DAWN THURSDAY INTO FRIDAY MORNING.
AGAIN STARTED WITH THE BCCONSSHORT FOR T/TD AND WINDS THROUGH THE
NEXT 24 HOURS AND THEN USED THE BCCONSALL. DID MAKE SOME MINUSCULE
ADJUSTMENTS TO THE VALLEY AND RIDGE TEMPERATURES TONIGHT AND THURSDAY
NIGHT. FOR POPS...ENDED CLOSEST TO THE MAV NUMBERS TONIGHT AND THEN
SIMILAR TO A MOS BLEND THROUGH FRIDAY MORNING.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 255 PM EDT WED JUN 18 2014
THE UPPER LEVEL RIDGING WHICH HAS BROUGHT US THE RECENT HOT WEATHER
WILL BE SHIFTING OFF TO THE SOUTHWEST DURING THE LONG TERM PERIOD OF
THE FORECAST. DESPITE THIS EXPECT TEMPERATURES TO REMAIN ABOVE
NORMAL. HOWEVER THE CHANCES FOR PRECIPITATION WILL BE GREATER THAN
THEY HAVE BEEN RECENTLY AS WEAK DISTURBANCES MOVE ACROSS THE REGION
FROM THE NORTHWEST. A WEAK COLD FRONT WILL PASS THROUGH THE AREA
EARLY SATURDAY WITH THE BEST CHANCE OF RAIN FRIDAY INTO EARLY
SATURDAY. BOTH THE GFS AND NAM FORECAST PRECIPITABLE WATER 1.80 TO
OVER 1.95 INCHES AT 00Z ON SATURDAY...OR AROUND OR POSSIBLY GREATER
THAN THE 99TH PERCENTILE. THIS...COMBINED WITH STORM MOTION FORECAST
TO BE 5 TO 15 KNOTS COULD LEAD TO LOCALLY HEAVY RAIN FRIDAY INTO
FRIDAY NIGHT...AND ISOLATED FLOODING. HAVE MENTIONED THIS
POSSIBILITY IN THE LATEST HAZARDOUS WEATHER OUTLOOK.
THE FRONT SHOULD GET FAR ENOUGH SOUTH THAT RAIN CHANCES WILL
DECREASE OVER THE WEEKEND BUT STILL NEED TO BE MENTIONED IN THE
FORECAST. WHILE THERE IS DECENT MODEL AGREEMENT TO START THE LONG
TERM PERIOD THERE ARE CONSIDERABLE DIFFERENCES NEXT WEEK...BUT NOT
ANY THAT CHANGE THE OVERALL FORECAST OF DAILY SHOWER AND
THUNDERSTORM CHANCES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 131 AM EDT THU JUN 19 2014
VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH MOST OF THE PERIOD.
CLOUD COVER WILL CONTINUE TO STREAM IN FROM THE NORTH AS A CLUSTER OF
THUNDERSTORMS MOVES SOUTH ACROSS INDIANA AND OHIO. THESE STORMS ARE
EXPECTED TO EVENTUALLY MAKE A SHARP TURN EASTWARD...WITH OUR
NORTHERNMOST COUNTIES PERHAPS SEEING SCATTERED SHOWERS AND STORMS BY
8 OR 9Z. COLD FRONT WILL THEN MOVE SLOWLY SOUTHWARD OUT OF THE UPPER
OHIO VALLEY DURING THE DAY...LEADING TO MORE SHOWERS AND STORMS
BEGINNING BETWEEN 15 AND 17Z TODAY. THE FRONT LOOKS TO STALL OUT JUST
NORTH OF THE RIVER...BRINGING A CONTINUED THREAT OF SHOWERS AND
STORMS TO THE AREA NORTH OF THE HAL ROGERS PARKWAY AND HIGHWAY 80
CORRIDOR. JKL AND SJS WILL SEE THE HIGHEST LIKELIHOOD OF PRECIPITATION
DURING THE TAF PERIOD. LOZ AND SME WILL ISOLATED TO SCATTERED SHOWERS
AND STORMS DURING THE PERIOD BEGINNING AROUND 16Z TODAY. CIGS OF 3.5
TO 4K WILL BE COMMON WITH ANY SHOWERS AND STORMS THAT AFFECT THE TAF
SITES TODAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...GREIF
LONG TERM...SBH
AVIATION...AR
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1230 AM EDT THU JUN 19 2014
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 330 PM EDT WED JUN 18 2014
OCCASIONAL THUNDERSTORMS WILL CONTINUE OVERNIGHT BUT THERE SHOULD
BE A BREAK ON THURSDAY INTO THURSDAY NIGHT BEFORE THE STORMS
RETURN ON FRIDAY AND OVER THE WEEKEND.
&&
.UPDATE...
ISSUED AT 1000 PM EDT WED JUN 18 2014
WILL CANCEL THE FLASH FLOOD WATCH AS THE HEAVIEST RAINS ARE OVER
THROUGH THE REST OF TONIGHT. LEFT AREAS OF FOG IN...BUT IT APPEARS
IT WILL BE FAIRLY PATCHY WITH 15+ KNOTS WINDS AT 1K FT.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 330 PM EDT WED JUN 18 2014
LINE OF STORMS DEPARTING THE EASTERN FORECAST AREA LATE THIS
AFTERNOON WITH A LULL EXPECTED INTO EARLY THIS EVENING. AIRMASS
SHOULD GET A CHANCE TO DESTABILIZE BEFORE SUNSET...WHICH ALLOWS NEW
STORMS TO FIRE UP AS AN MCV TRACKS ACROSS THE SOUTHERN FORECAST
AREA. THIS HAS BEEN INDICATED BY THE HRRR AS WELL AS THE 12Z GFS
AND ECMWF. POPS AND QPF SHADED HIGHER ACROSS THE SOUTH.
STORMS DIMINISH THURSDAY UNDER SHORT WAVE RIDGING AND PICK UP
AGAIN FRIDAY.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 330 PM EDT WED JUN 18 2014
QUASI ZONAL FLOW WILL RESULT IN WEAK UPPER IMPULSES MOVING ACROSS
THE UPPER MIDWEST DURING THE PERIOD. ONE OF THOSE WAVES WILL PUSH A
WEAK COLD FRONT EAST THROUGH THE GREAT LAKES SUNDAY. THIS FRONTAL
BOUNDARY WILL LINGER ACROSS THE CWA FOR SEVERAL DAYS AS LOW PRESSURE
IN THE CENTRAL PLAINS SLOWLY MOVES ENE. WE/LL HAVE CHC POPS
BEGINNING SUNDAY AND CARRY THAT THROUGH MUCH OF THE REST OF THE
PERIOD. GFS AND ECMWF ARE IN REASONABLE AGREEMENT MOVING THE LOW TO
ILLINOIS BY WEDNESDAY. THE ECMWF HAS HIGHER QPF VS THE GFS BUT BOTH
SHOW SHOWERS. WE/LL LIKELY HAVE TO INCREASE POPS FOR THE MIDDLE OF
NEXT WEEK IF THE TREND CONTINUES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1229 AM EDT THU JUN 19 2014
LOW CEILINGS AND FOG ARE NOW SETTLING INTO THE TAF SITES...AND THE
TREND SHOULD CONTINUE TO BE DOWN AT LEAST IN REGARD TO CEILINGS.
EXPECTING IFR CEILINGS AT ALL THE TAFS SITES WITH ABUNDANT LOW
LEVEL MOISTURE IN PLACE. LIFR AND LOWER IS POSSIBLE AS WELL WITH
400FT CEILINGS ALREADY IN PLACE AT KJXN. THE FOG SHOULD NOT GET
TOO BAD WITH SOME WIND AT 1000FT...SO EXPECTING VSBY/S TO REMAIN
MVFR. CEILINGS SHOULD LIFT SLOWLY THROUGH THE MORNING HOURS OF
THURSDAY WITH VFR CONDITIONS GRADUALLY TAKING OVER IN THE 16Z TO
19Z TIME FRAME. VFR WEATHER IS EXPECTED THURSDAY EVENING.
&&
.MARINE...
ISSUED AT 317 PM EDT WED JUN 18 2014
SHOWERS AND THUNDERSTORMS...ALONG WITH AREAS OF FOG...WILL PERSIST
OVERNIGHT. WINDS AND WAVES WILL BE LOCALLY HIGHER IN AND NEAR
THUNDERSTORMS...BUT OTHERWISE REMAIN BLO SMALL CRAFT ADVISORY THE
NEXT COUPLE DAYS.
&&
.HYDROLOGY...
ISSUED AT 100 PM EDT WED JUN 18 2014
RIVERS ARE RUNNING WELL WITHIN THEIR BANKS AND NEAR NORMAL LEVELS
FOR THIS TIME OF YEAR. HOWEVER... THE GRAND AND MUSKEGON RIVERS ARE
BEGINNING TO SLOWLY RISE DUE TO THE RAIN FROM TUESDAY AND TODAY.
ONLY THE ROGUE RIVER AT ROCKFORD LOOKS LIKE IT MAY RISE TO NEAR
BANKFULL... AND THAT WOULD BE TOMORROW. ADDITIONAL RAIN THIS
AFTERNOON SHOULD ADD LITTLE ADDITIONAL RISE TO THE RIVERS. THURSDAY
MIGHT BE A DRY DAY... BUT ADDITIONAL RAINFALL THURSDAY NIGHT AND
FRIDAY COULD BRING MORE POINTS UP TO NEAR BANKFULL. RIVER FLOODING
IS NOT EXPECTED. MINOR AREAL FLOODING IS A POSSIBILITY DUE TO THE
HEAVY RAIN IN THE THUNDERSTORMS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...JK
SYNOPSIS...OSTUNO
SHORT TERM...OSTUNO
LONG TERM...93
AVIATION...DUKE
HYDROLOGY...63
MARINE...OSTUNO
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
128 PM CDT THU JUN 19 2014
.UPDATE...FOR 18Z AVIATION DISCUSSION
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 413 AM CDT THU JUN 19 2014
ANOTHER ACTIVE NIGHT IS WINDING DOWN...AND FOR THE SECOND NIGHT IN A
ROW WE SAW SOME PRETTY IMPRESSIVE RAINFALL TOTALS RESULT FROM
TRAINING THUNDERSTORMS. TUESDAY NIGHT WAS MANKATO...AND LAST NIGHT
IT WAS WOOD LAKE...WHERE RADAR ESTIMATES SHOW 6 TO 7 INCHES OF RAIN
FELL...AND MUCH OF THAT CAME WITHIN THE FIRST 3 HOURS OF IT STARING
TO RAIN. UNFORTUNATELY...THE ATMOSPHERE THAT HELPED ALLOW THAT TO
HAPPEN WITH PWATS AOA 1.75" AND FREEZING LEVELS ABOVE 15K ARE STILL
IN PLACE AND WILL REMAIN SO UNTIL A COLD FRONT CURRENTLY BACK OVER
ERN SODAK CLEARS THE AREA TONIGHT.
FOR THIS MORNING...THE RAP SHOWS THE LLJ BECOMING BIFURCATED...WITH
ONE SEGMENT SAGGING SE ACROSS IA TOWARD NRN IL...WHILE ANOTHER
SECTION WILL BE ANGLING FROM SRN MN BACK TOWARD ERN NODAK. YOU CAN
SEE THE IMPACTS OF THIS LLJ SLIT OVER THE LAST HOUR ON REGIONAL
RADARS AS ACTIVITY HAS REALLY STARTED TO BECOME FOCUSED OVER NE IA.
THE SEGMENT OF THE LLJ DEVELOPING FARTHER TO THE NORTHWEST IS
HELPING FORCE AN INTENSE LINE OF STORMS CURRENTLY RACING NORTH
ACROSS ERN SODAK. WHAT THIS MEANS FOR THE MPX CWA IS THE CLUSTER OF
STORMS OVER ERN MN WILL BEGIN TO SLOWLY DIMINISH ACROSS WRN WI THIS
MORNING AS IT LOSES ITS LLJ FEED...WITH THE WRN LLJ SEGMENT
FOCUSING ACTIVITY INTO NW MN THIS MORNING. THIS WILL SEND US INTO
ANOTHER PRECIP BREAK PERIOD THAT WILL START BETWEEN 15 AND 18Z.
UNFORTUNATELY...THIS BREAK WILL BE VERY SHORT LIVED. AS THE SODAK
FRONT WORKS INTO WRN MN THIS AFTERNOON...CURRENT EXPECTATION IS THAT
YET ANOTHER LINE OF THUNDERSTORMS WILL DEVELOP NEAR A RWF/AXN LINE
BETWEEN 18Z AND 20Z THAT WILL THEN WORK EAST THROUGH THE OVERNIGHT
HOURS. MOST CAMS SHOW THIS SCENARIO PLAYING OUT...BUT THE SPC AND
ARW WRFS SHOW VERY LITTLE CONVECTION FORMING ALONG THE FRONT.
ALTHOUGH THE CURRENT FORECAST WEIGHS HEAVILY ON THE CONVECTING
MAJORITY...YOU CAN NOT COMPLETELY RULE OUT THE MORE LIMITED
SOLUTIONS DEPENDING ON HOW MUCH CONVECTION TONIGHT CAN OVERTURN THE
ATMOSPHERE. IF ENOUGH OVERTURNING OCCURS...THEN THOSE LIMITED
ACTIVITY SOLUTIONS MAY BE CORRECT. HOWEVER...WITH THE LOSS OF THE
MID LEVEL WARM AIR CAP...PREFER THE SOLUTIONS THAT SHOW ANOTHER
ROUND OF CONVECTION DEVELOPING ALONG THE BOUNDARY THIS AFTERNOON.
FOR THE SEVERE POTENTIAL...THINKING THE THREAT...THOUGH STILL
THERE...WILL NOT BE AS GREAT AS THE LAST COUPLE OF DAYS. ONE BIG
REASON IS THAT THE 5K TO 6K J/KG OF MLCAPE IN THE WARM SECTOR SEEN
TUESDAY AND WEDNESDAY WILL BE REPLACED BY A MUCH MORE MODEST 1K TO
2K J/KG TODAY. IN ADDITION...0-6KM SHEAR WILL BE RANGING FROM 35-40
KTS NEAR THE MN/SD BORDER /CLOSER TO THE UPPER LOW/ TO LESS THAN 20
KTS OVER WRN WI. THE ONE THING THAT IS BETTER TODAY THAN WHAT WE SAW
YESTERDAY ARE THE DYNAMICS AS A NEGATIVELY TILTED TROUGH APPROACHES
WRN MN BY 00Z WITHIN THE RIGHT ENTRANCE REGION OF A 70+ KT LLJ. MORE
BOUNDARY PARALLEL SHEAR THIS AFTERNOON FAVORS A LINEAR CONVECTIVE
MODE. THE MAIN THREAT WILL LIKELY BE DAMAGING STRAIGHT LINE
WINDS...AS THE SMALLER CAPES AND LINEAR MODE SHOULD BOTH HELP TO
SUPPRESS THE HAIL AND TORNADO THREATS /AS COMPARED TO THE LAST
COUPLE OF DAYS/.
THOUGH UNDER NORMAL CIRCUMSTANCES...A FRONT LIKE THIS AFTERNOONS
WOULD NOT TYPICALLY GARNER A FLASH FLOOD WATCH...THIS IS NOT A
TYPICAL SITUATION AS ALL BUT THE NRN TIER OF THE MPX CWA HAS SEEN 4
TO 10 INCHES OF RAIN SINCE FRIDAY ON TOP OF WHAT WAS ALREADY ONE OF
THE WETTEST STARTS TO A YEAR ON RECORD. WITH ONLY A SMALL BREAK IN
THE HEAVY RAINFALL EXPECTED...EXTENDED THE FLASH FLOOD WATCH OUT IN
TIME TO 6Z TONIGHT WEST OF I-35 AND TO 12Z TONIGHT EAST OF I-35. THE
WATCH WAS ALSO EXPANDED NORTH TO INCLUDE THE AREAS THAT HAVE
RECEIVED 3+ INCHES OF RAIN SINCE FRIDAY. ALSO ENDED THE WATCH AT 15Z
FOR THE FAR WRN COUNTIES...AS THE NEXT ROUND OF PRECIPITATION LOOKS
TO START OVER OR JUST EAST OF THOSE COUNTIES...SO CURRENT
EXPECTATIONS ARE THAT THE HEAVY RAIN THREAT WILL SHIFT EAST OF THOSE
COUNTIES AFTER THIS MORNING.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 413 AM CDT THU JUN 19 2014
A DRIER POST FRONTAL AIR MASS IS EXPECTED BY FRIDAY MORNING ACROSS
THE FORECAST AREA WITH A SURFACE ACROSS CENTRAL AND EASTERN WI. WE
THINK THERE IS A DECENT CHANCE AT SUNSHINE AND MODEST W-SW FLOW
COMBINED WITH 16-19 C AT 850 MB TEMPS SHOULD YIELD HIGHS WELL INTO
THE 80S ACROSS MOST OF THE FORECAST AREA /WESTERN WI SHOULD BE A
FEW DEGREES COOLER THAN MN/. BY SATURDAY MORNING THE TROUGH ACROSS
THE NORTHERN HIGH PLAINS SHOULD BUILD SOUTH AND MOISTURE RETURN
SHOULD BRING PWATS BACK UP NEAR 1.5-1.75" IN THE FAR WESTERN
FORECAST AREA. THE RETURN OF WEAK 925-850MB MOISTURE TRANSPORT AND
FGEN BACK ACROSS NORTHERN NE AND EASTERN SD COULD MEAN A FEW
THUNDERSTORMS MAKE IT INTO WESTERN MN ON SATURDAY...BUT THE BETTER
FOCUS IS IN THE STATES THAT BORDER MN TO THE SOUTH AND WEST. THE
PRECIP SIGNAL ON SUNDAY IS MUDDLED WITH A SURFACE TROUGH AND AN
INCREASE IN CONVERGENCE AND OMEGA...BUT WE CAN`T PIN DOWN AN AREA
TO FOCUS POPS/WEATHER AT THIS TIME. AT THIS TIME...THE POTENTIAL
FOR WIDESPREAD HEAVY RAIN IS LOW AND THE OVERALL COVERAGE OF
STORMS SHOULD BE ISOLATED TO SCATTERED. DURING THIS TIME...THE
UPPER LOW THAT HAS BEEN CAMPED OUT TO OUR NORTHWEST DRIFTS SLOWLY
NORTH WITH TIME AND THE LONG WAVE FLOW TURNS MORE ZONAL /SLIGHT
RIDGING/. BOTH THE 19.00Z GFS/ECMWF AND TO SOME DEGREE NAM HAVE A
FAST-MOVING SHORTWAVE EMBEDDED IN THE PSEUDO-ZONAL FLOW ARRIVING
IN THE MID/UPPER MISSISSIPPI RIVER VALLEY BY MONDAY. THE SURFACE
BOUNDARY SHOULD BE STRETCHED OUT ACROSS KS/IA/WI WHICH SHOULD BE
THE MAIN FOCUS FOR THUNDERSTORMS EARLY NEXT WEEK. THE 00Z GFS IS
MUCH MORE AGGRESSIVE IN BRINGING IN COOLER AIR TO THE AREA AND
ASSOCIATED HIGH PRESSURE BY TUESDAY. 00Z GFS NOW SHOWING 850 TEMPS
OF 8C TO 10C FOR TUESDAY AND WEDNESDAY. 00Z EURO AND EVEN THE
PREVIOUS ENSEMBLE RUNS STILL HAS 850 TEMPS OF 12C TO 14C DURING
THAT TIME FRAME. THIS IS A BIG CHANGE FROM PAST GFS RUNS.
SO...MODEL CONSENSUS AND ENSEMBLES ARE THE WAY TO GO. IT IS
IMPORTANT TO NOTE THAT THE ECMWF HAS ALSO SHOWED AGREES IVE COLD
ADVECTION WITH A RUN OR TWO IN THE PAST 2-3 DAYS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 128 PM CDT THU JUN 19 2014
THE NEXT ROUND OF THUNDERSTORMS IS BEGINNING TO SHOW THE WHITES OF
ITS EYES OVER NORTHERN IOWA AND WESTERN MINNESOTA. EXPECT THIS
LINE TO FILL IN AND EXPAND EAST NORTHEAST ACROSS THE TAF AREA
MAINLY BETWEEN 21Z AND 06Z. PREVALENT MVFR CONDITIONS WITH BRIEF
IFR CONDITIONS WHEN THE STORMS ARRIVE ARE EXPECTED. THERE IS A
RISK...ALBEIT LOW...FOR GUSTY WINDS AND SMALL HAIL WITH THIS LINE
OF THUNDERSTORMS. SHOULD SEE THE BULK OF THE ACTIVITY MOVE OUT OF
MN BY 06 AND WEST CENTRAL WI BY 09Z. COULD SEE SOME BR IN THE WAKE
OF THE SHRA/TS AS WINDS DECREASE BELOW 5 KTS AND COUPLE WITH
CLEARING SKIES AND SATURATED SOIL CONDITIONS. VFR CONDITIONS ARE
THEN EXPECTED AFTER 15Z FRIDAY.
KMSP...
EXPECT THE NEXT ROUND OF SHRA/TS TO IMPACT KMSP BETWEEN 22Z AND
02Z. MVFR CONDITIONS WILL PREVAIL WITH BR POSSIBLE IN THE WAKE OF
THE STORMS. CIGS SCATTER OUT OVERNIGHT WITH VFR CONDITIONS BY
DAYBREAK FRIDAY. GUSTY EASTERLY WINDS THIS AFTERNOON GRADUALLY
VEER TO THE SOUTHEAST AND DECREASE BELOW 10 KTS FOR THIS
EVE...THEN BECOME LIGHT SOUTHWESTERLY OVERNIGHT.
/OUTLOOK FOR KMSP/
SAT...VFR. MVFR ISO SHRA/TSRA POSSIBLE. WINDS SW 5-10 KTS.
SUN...VFR. MVFR SHRA/TSRA POSSIBLE. WINDS ESE 5 KTS BECMG WNW 5-10KTS.
MON...VFR. WINDS NW 10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR MNZ057>061-065>069-
073>077-082>085-091>093.
FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR MNZ062-063-070-078.
WI...FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR WIZ023>028.
&&
$$
SHORT TERM...MPG
LONG TERM...CLF
AVIATION...LS
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
713 AM CDT THU JUN 19 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 413 AM CDT THU JUN 19 2014
ANOTHER ACTIVE NIGHT IS WINDING DOWN...AND FOR THE SECOND NIGHT IN A
ROW WE SAW SOME PRETTY IMPRESSIVE RAINFALL TOTALS RESULT FROM
TRAINING THUNDERSTORMS. TUESDAY NIGHT WAS MANKATO...AND LAST NIGHT
IT WAS WOOD LAKE...WHERE RADAR ESTIMATES SHOW 6 TO 7 INCHES OF RAIN
FELL...AND MUCH OF THAT CAME WITHIN THE FIRST 3 HOURS OF IT STARING
TO RAIN. UNFORTUNATELY...THE ATMOSPHERE THAT HELPED ALLOW THAT TO
HAPPEN WITH PWATS AOA 1.75" AND FREEZING LEVELS ABOVE 15K ARE STILL
IN PLACE AND WILL REMAIN SO UNTIL A COLD FRONT CURRENTLY BACK OVER
ERN SODAK CLEARS THE AREA TONIGHT.
FOR THIS MORNING...THE RAP SHOWS THE LLJ BECOMING BIFURCATED...WITH
ONE SEGMENT SAGGING SE ACROSS IA TOWARD NRN IL...WHILE ANOTHER
SECTION WILL BE ANGLING FROM SRN MN BACK TOWARD ERN NODAK. YOU CAN
SEE THE IMPACTS OF THIS LLJ SLIT OVER THE LAST HOUR ON REGIONAL
RADARS AS ACTIVITY HAS REALLY STARTED TO BECOME FOCUSED OVER NE IA.
THE SEGMENT OF THE LLJ DEVELOPING FARTHER TO THE NORTHWEST IS
HELPING FORCE AN INTENSE LINE OF STORMS CURRENTLY RACING NORTH
ACROSS ERN SODAK. WHAT THIS MEANS FOR THE MPX CWA IS THE CLUSTER OF
STORMS OVER ERN MN WILL BEGIN TO SLOWLY DIMINISH ACROSS WRN WI THIS
MORNING AS IT LOSES ITS LLJ FEED...WITH THE WRN LLJ SEGMENT
FOCUSING ACTIVITY INTO NW MN THIS MORNING. THIS WILL SEND US INTO
ANOTHER PRECIP BREAK PERIOD THAT WILL START BETWEEN 15 AND 18Z.
UNFORTUNATELY...THIS BREAK WILL BE VERY SHORT LIVED. AS THE SODAK
FRONT WORKS INTO WRN MN THIS AFTERNOON...CURRENT EXPECTATION IS THAT
YET ANOTHER LINE OF THUNDERSTORMS WILL DEVELOP NEAR A RWF/AXN LINE
BETWEEN 18Z AND 20Z THAT WILL THEN WORK EAST THROUGH THE OVERNIGHT
HOURS. MOST CAMS SHOW THIS SCENARIO PLAYING OUT...BUT THE SPC AND
ARW WRFS SHOW VERY LITTLE CONVECTION FORMING ALONG THE FRONT.
ALTHOUGH THE CURRENT FORECAST WEIGHS HEAVILY ON THE CONVECTING
MAJORITY...YOU CAN NOT COMPLETELY RULE OUT THE MORE LIMITED
SOLUTIONS DEPENDING ON HOW MUCH CONVECTION TONIGHT CAN OVERTURN THE
ATMOSPHERE. IF ENOUGH OVERTURNING OCCURS...THEN THOSE LIMITED
ACTIVITY SOLUTIONS MAY BE CORRECT. HOWEVER...WITH THE LOSS OF THE
MID LEVEL WARM AIR CAP...PREFER THE SOLUTIONS THAT SHOW ANOTHER
ROUND OF CONVECTION DEVELOPING ALONG THE BOUNDARY THIS AFTERNOON.
FOR THE SEVERE POTENTIAL...THINKING THE THREAT...THOUGH STILL
THERE...WILL NOT BE AS GREAT AS THE LAST COUPLE OF DAYS. ONE BIG
REASON IS THAT THE 5K TO 6K J/KG OF MLCAPE IN THE WARM SECTOR SEEN
TUESDAY AND WEDNESDAY WILL BE REPLACED BY A MUCH MORE MODEST 1K TO
2K J/KG TODAY. IN ADDITION...0-6KM SHEAR WILL BE RANGING FROM 35-40
KTS NEAR THE MN/SD BORDER /CLOSER TO THE UPPER LOW/ TO LESS THAN 20
KTS OVER WRN WI. THE ONE THING THAT IS BETTER TODAY THAN WHAT WE SAW
YESTERDAY ARE THE DYNAMICS AS A NEGATIVELY TILTED TROUGH APPROACHES
WRN MN BY 00Z WITHIN THE RIGHT ENTRANCE REGION OF A 70+ KT LLJ. MORE
BOUNDARY PARALLEL SHEAR THIS AFTERNOON FAVORS A LINEAR CONVECTIVE
MODE. THE MAIN THREAT WILL LIKELY BE DAMAGING STRAIGHT LINE
WINDS...AS THE SMALLER CAPES AND LINEAR MODE SHOULD BOTH HELP TO
SUPPRESS THE HAIL AND TORNADO THREATS /AS COMPARED TO THE LAST
COUPLE OF DAYS/.
THOUGH UNDER NORMAL CIRCUMSTANCES...A FRONT LIKE THIS AFTERNOONS
WOULD NOT TYPICALLY GARNER A FLASH FLOOD WATCH...THIS IS NOT A
TYPICAL SITUATION AS ALL BUT THE NRN TIER OF THE MPX CWA HAS SEEN 4
TO 10 INCHES OF RAIN SINCE FRIDAY ON TOP OF WHAT WAS ALREADY ONE OF
THE WETTEST STARTS TO A YEAR ON RECORD. WITH ONLY A SMALL BREAK IN
THE HEAVY RAINFALL EXPECTED...EXTENDED THE FLASH FLOOD WATCH OUT IN
TIME TO 6Z TONIGHT WEST OF I-35 AND TO 12Z TONIGHT EAST OF I-35. THE
WATCH WAS ALSO EXPANDED NORTH TO INCLUDE THE AREAS THAT HAVE
RECEIVED 3+ INCHES OF RAIN SINCE FRIDAY. ALSO ENDED THE WATCH AT 15Z
FOR THE FAR WRN COUNTIES...AS THE NEXT ROUND OF PRECIPITATION LOOKS
TO START OVER OR JUST EAST OF THOSE COUNTIES...SO CURRENT
EXPECTATIONS ARE THAT THE HEAVY RAIN THREAT WILL SHIFT EAST OF THOSE
COUNTIES AFTER THIS MORNING.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 413 AM CDT THU JUN 19 2014
A DRIER POST FRONTAL AIR MASS IS EXPECTED BY FRIDAY MORNING ACROSS
THE FORECAST AREA WITH A SURFACE ACROSS CENTRAL AND EASTERN WI. WE
THINK THERE IS A DECENT CHANCE AT SUNSHINE AND MODEST W-SW FLOW
COMBINED WITH 16-19 C AT 850 MB TEMPS SHOULD YIELD HIGHS WELL INTO
THE 80S ACROSS MOST OF THE FORECAST AREA /WESTERN WI SHOULD BE A
FEW DEGREES COOLER THAN MN/. BY SATURDAY MORNING THE TROUGH ACROSS
THE NORTHERN HIGH PLAINS SHOULD BUILD SOUTH AND MOISTURE RETURN
SHOULD BRING PWATS BACK UP NEAR 1.5-1.75" IN THE FAR WESTERN
FORECAST AREA. THE RETURN OF WEAK 925-850MB MOISTURE TRANSPORT AND
FGEN BACK ACROSS NORTHERN NE AND EASTERN SD COULD MEAN A FEW
THUNDERSTORMS MAKE IT INTO WESTERN MN ON SATURDAY...BUT THE BETTER
FOCUS IS IN THE STATES THAT BORDER MN TO THE SOUTH AND WEST. THE
PRECIP SIGNAL ON SUNDAY IS MUDDLED WITH A SURFACE TROUGH AND AN
INCREASE IN CONVERGENCE AND OMEGA...BUT WE CAN`T PIN DOWN AN AREA
TO FOCUS POPS/WEATHER AT THIS TIME. AT THIS TIME...THE POTENTIAL
FOR WIDESPREAD HEAVY RAIN IS LOW AND THE OVERALL COVERAGE OF
STORMS SHOULD BE ISOLATED TO SCATTERED. DURING THIS TIME...THE
UPPER LOW THAT HAS BEEN CAMPED OUT TO OUR NORTHWEST DRIFTS SLOWLY
NORTH WITH TIME AND THE LONG WAVE FLOW TURNS MORE ZONAL /SLIGHT
RIDGING/. BOTH THE 19.00Z GFS/ECMWF AND TO SOME DEGREE NAM HAVE A
FAST-MOVING SHORTWAVE EMBEDDED IN THE PSUEDO-ZONAL FLOW ARRIVING
IN THE MID/UPPER MISSISSIPPI RIVER VALLEY BY MONDAY. THE SURFACE
BOUNDARY SHOULD BE STRETCHED OUT ACROSS KS/IA/WI WHICH SHOULD BE
THE MAIN FOCUS FOR THUNDERSTORMS EARLY NEXT WEEK. THE 00Z GFS IS
MUCH MORE AGGRESSIVE IN BRINGING IN COOLER AIR TO THE AREA AND
ASSOCIATED HIGH PRESSURE BY TUESDAY. 00Z GFS NOW SHOWING 850 TEMPS
OF 8C TO 10C FOR TUESDAY AND WEDNESDAY. 00Z EURO AND EVEN THE
PREVIOUS ENSEMBLE RUNS STILL HAS 850 TEMPS OF 12C TO 14C DURING
THAT TIME FRAME. THIS IS A BIG CHANGE FROM PAST GFS RUNS.
SO...MODEL CONSENSUS AND ENSEMBLES ARE THE WAY TO GO. IT IS
IMPORTANT TO NOTE THAT THE ECMWF HAS ALSO SHOWED AGREES IVE COLD
ADVECTION WITH A RUN OR TWO IN THE PAST 2-3 DAYS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 648 AM CDT THU JUN 19 2014
ACTIVITY CONTINUES TO FESTER THIS MORNING ON THE NOSE OF THE LLJ.
BASED ON LLJ FORECAST THIS ACTIVITY MAY LINGER MOST OF THE
MORNING...WHICH WOULD HAVE IMPLICATIONS FOR THE POTENTIAL
AFTERNOON CONVECTION. THAT AFTERNOON CONVECTION HAS BETTER MODEL
AGREEMENT WITH INVITATION BETWEEN 18 AND 20Z NEAR A RWF/AXN LINE
BEFORE TRAVELING EAST THE REST OF THE EVENING. USED THE HRRR AND
LOCAL WRF TO TIME THIS EXPECTED LINE ACROSS THE TERMINALS. OF
COURSE IF THIS MORNING STUFF DOES NOT CLEAN OUT ANY TIME
SOON...THIS COULD LIMIT THE POTENTIAL FOR THIS NEXT ROUND ON THE
FRONT. MVFR CIGS THIS MORNING HAVE BEEN MAINLY TIED TO
PRECIPITATION...WITH BEST CHANCE FOR MVFR OR LOWER CIGS/VIS
OUTSIDE OF SHRA/TSRA COMING TONIGHT AS THE FRONT/SFC TROUGH WORKS
INTO THE AREA AND CAUSES THE PRESSURE GRADIENT TO RELAX WITH
MOISTURE STILL LINGERING OUTSIDE OF WESTERN MN.
KMSP...FROM THE LOOK OF THINGS AS I WRITE THIS...WE MAY BE DEALING
WITH THUNDERSTORMS OUT CLOSER TO 18Z AS OPPOSED TO 14Z AS ACTIVITY
CONTINUES TO BUILD BACK TO THE SW. THERE IS STRONG MODEL AGREEMENT
ON THE AFTERNOON/EVENING THUNDERSTORMS...BUT WITH THE WAY THINGS
ARE TRENDING THIS MORNING...THINGS MAY NOT PLAY OUT THE WAY THEY
ARE CURRENTLY PLANNED OUT IN THE TAF WITH THE MOST LIKELY SCENARIO
BEING THAT THERE IS LESS CONVECTION THAN EXPECTED WITH THE
AFTERNOON ROUND.
/OUTLOOK FOR KMSP/
FRI...VFR. MVFR ISO SHRA/TSRA POSSIBLE. WINDS SW 10 KTS.
SAT...VFR. MVFR ISO SHRA/TSRA POSSIBLE. WINDS W 10 KTS.
SUN...VFR. MVFR SHRA/TSRA POSSIBLE. WINDS WNW 10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR MNZ057>061-065>069-
073>077-082>085-091>093.
FLASH FLOOD WATCH UNTIL 10 AM CDT THIS MORNING FOR MNZ047-
054>056-064.
FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR MNZ062-063-070-078.
WI...FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR WIZ023>028.
&&
$$
SHORT TERM...MPG
LONG TERM...CLF
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS DULUTH MN
645 AM CDT THU JUN 19 2014
.SHORT TERM...(TODAY THROUGH FRIDAY AFTERNOON)
ISSUED AT 332 AM CDT THU JUN 19 2014
MAIN CONCERNS IN THE SHORT TERM REMAIN FOCUSED AROUND THE INCOMING
SHOWERS AND THUNDERSTORMS...CURRENTLY MOVING THROUGH N-CENTRAL MN AND
EXPECTED TO LIFT TO THE N/NE THROUGH THE DAY AND INTO TONIGHT. THE
MAIN IMPACTS FROM THIS SYSTEM WILL BE THE THREAT FOR MORE HEAVY
RAINFALL ON ALREADY SATURATED SOILS AND DRAINAGE INTO HIGH RIVERS
AND LAKES. THE HEAVIEST RAINFALL IS EXPECTED TO FALL ACROSS N-CNTRL
AND E-CNTRL MN...WITH 1-1.5 INCH AMTS POSSIBLE. LESSER AMTS WILL
BE SEEN ACROSS THE REST OF THE NORTHLAND...WITH ONE HALF TO THREE
QUARTERS OF AN INCH POSSIBLE.
AREAS OF NORTHERN MN CURRENTLY EXPERIENCING FLOODING ALONG THE
INTERNATIONAL BORDER ARE EXPECTED TO SEE AN ADDITIONAL 3/4 TO 1
INCH OF RAIN TODAY THROUGH FRI AFTERNOON.
UPPER RIDGE ACROSS THE REGION ON WED IS SLIDING TO THE EAST AS A
NEGATIVELY TILTED TROUGH SWINGS IN FROM THE SW. AT THE SFC AN
ELONGATED TROUGH OF LOW PRESSURE SITUATED OVER THE ERN DAKOTAS
WILL CONTINUE TO BATTLE A STRONG SFC HIGH OVER HUDSON BAY AND
GRADUALLY LIFT TO THE N/NE THROUGH THE DAY. THE VERY MOIST AND
UNSTABLE AIR MASS IN PLACE...COMBINED WITH A STAGNANT FLOW ALOFT
WILL CONTRIBUTE TO THE POTENTIAL FOR SLOW MOVING HEAVY PRECIP
THUNDERSTORMS. THE CHALLENGE WILL BE THE BATTLE BETWEEN THE COOL
DRY AIR MASS FROM THE CANADIAN HIGH AND THE WARM MOIST AIR FROM
THE SOUTH. WHICH ONE WILL WIN OUT AND AT WHAT POINT DOES THE AXIS
OF STRONG MOISTURE ADVECTION MAKE A STRONG PUSH EWD ACROSS THE
CWA. CURRENT MODEL GUIDANCE INDICATES THAT THE 18-00Z TIME FRAME
THIS AFTERNOON IS MOST FAVORABLE FOR CONVECTIVE RE-DEVELOPMENT
OVER N-CNTRL MN...WITH SIGNIFICANT MOVEMENT TO THE NE DURING THE
00-06Z TIME FRAME THIS EVENING. INSTABILITY AND DEEP LAYER SHEAR
WILL BE LIMITED TODAY AND TONIGHT...WHICH WILL INHIBIT THE LEVEL
OF CONVECTIVE ACTIVITY AND KEEP THE FOCUS ON THE THREAT FOR HEAVY
RAIN. A FEW OF THE STORMS COULD PRODUCE GUSTY WINDS AND SMALL
HAIL.
RAIN SHOWERS AND STORMS WILL GRADUALLY TAPER OFF FROM SW TO NE
DURING THE DAY FRIDAY...BUT LINGER ACROSS THE ARROWHEAD AND NRN WI
THROUGH MOST OF THE DAY. THE SFC LOW WRAPPING UP IN SRN
SASKATCHEWAN AND SRN MANITOBA WILL EVENTUALLY MAKE MOVEMENT EWD
AND BRING IN ADDITIONAL CHANCES FOR SHOWERS/STORMS FROM THE NW FRI
AFTERNOON.
THE OTHER CONCERN TODAY AND TOMORROW WILL BE THE PERSISTENT E/NE
WINDS OFF LAKE SUPERIOR...KEEPING CONDITIONS MUCH COOLER AROUND
THE LAKE. LOW PRESSURE DEEPENING TO THE WEST WILL COMBINE WITH A
STRONG HUDSON BAY HIGH TO PRODUCE SIGNIFICANT PRES FALLS OVER NE
MN AND ACT TO INCREASE WINDS OFF THE LAKE ONCE AGAIN TODAY. EXPECT
SUSTAINED E WINDS AROUND 15 MPH AND GUSTS 20-30 MPH. AREAS INLAND
WILL LIKELY SEE TEMPS UP AROUND 70-75...WHILE LOCATIONS CLOSER TO
THE LAKE WILL SEE TEMPS ONLY INTO THE UPPER 50S TO AROUND 60. ON
FRIDAY...MORE SUN IS POSSIBLE WHICH WILL ALLOW INLAND TEMPS TO
RISE INTO THE 80S. THE LAKE WINDS ARE NOT EXPECTED TO BE AS
STRONG...SO JUST INLAND FROM THE LAKE COULD WARM INTO THE MID TO
UPPER 60S BUT NEARSHORE LOCATIONS WILL REMAIN IN THE UPPER 50S AND
LOWER 60S.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 332 AM CDT THU JUN 19 2014
AN UPPER LOW WILL CONTINUE TO MOVE NORTH THROUGH MB/SK EARLY IN THE
PERIOD...LEAVING THE NORTHLAND IN A QUASI ZONAL FLOW INTO EARLY NEXT
WEEK. THE UPPER FLOW WILL THEN AMPLIFY BY MONDAY WITH AN UPPER
TROUGH DEVELOPING OVER THE REGION. SIGNIFICANT DIFFERENCES DEVELOP
BETWEEN THE GFS/ECMWF BY MONDAY/TUESDAY IN HOW THEY HANDLE THE UPPER
TROUGH. THE ECMWF DEVELOPS A LARGE UPPER TROUGH OVER A GOOD PORTION
OF THE NORTHERN CONUS/ADJACENT CANADIAN PROVINCES...AND THE GFS IS
SHARPER WITH THE TROUGH AND MUCH MORE PROGRESSIVE. BOTH OF THESE
MODELS HAVE MADE SIGNIFICANT CHANGES OVER THEIR PREVIOUS RUNS...AND
CONFIDENCE IN ANY ONE SOLUTION IS LOWER THAN AVERAGE.
THERE WILL BE CHANCES FOR MORE SHOWERS/STORMS OVER THE WEEKEND WITH
SEVERAL SHORTWAVES MOVING THROUGH THE ZONAL FLOW AND MOISTURE
REMAINING OVER THE REGION. WIDESPREAD SIGNIFICANT RAIN DOES NOT LOOK
LIKELY OVER THE WEEKEND.
THE CHANCE FOR SHOWERS/STORMS WILL CONTINUE MONDAY/MONDAY NIGHT AS A
STRONGER WAVE ALOFT MOVES THROUGH THE NORTHLAND. AS
MENTIONED...CONFIDENCE REALLY STARTS TO DIMINISH IN THE
TUESDAY/WEDNESDAY TIME DUE TO MODEL UNCERTAINTY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 645 AM CDT THU JUN 19 2014
AN AREA OF RAIN AND THUNDERSTORMS COVERED A GOOD PORTIONS OF
CENTRAL AND SOUTHERN MINNESOTA AND WESTERN WISCONSIN EARLY THIS
MORNING. THE PRECIPITATION HAS BEEN DIMINISHING SOME ON THE
NORTHERN EDGE AS IT MOVES NORTH. TIMING THE PRECIP WILL BE ONE OF
THE CHALLENGES TODAY AND WE HAVE A MENTION IN ALL TAF SITES EARLY
IN THE PERIOD EXCEPT FOR KINL. THE RAIN/STORMS ARE FORECAST TO
DIMINISH IN COVERAGE LATER THIS MORNING...THEN INCREASE AGAIN
LATER THIS AFTERNOON OVER WESTERN AREAS...THEN MOVE EAST. MVFR/IFR
CEILINGS WILL IMPACT KBRD...AND MAY ALSO IMPACT KHYR/KHIB/KDLH FOR
A TIME THIS MORNING. THE RAP THEN SHOWS THOSE CEILINGS RISING EXCEPT AT
KBRD. MVFR/IFR CONDITIONS WILL BECOME MORE WIDESPREAD LATE TODAY
INTO TONIGHT ACROSS THE NORTHLAND.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 60 53 68 51 / 90 90 30 30
INL 73 59 79 56 / 80 80 40 30
BRD 74 64 85 61 / 90 80 20 20
HYR 77 62 78 58 / 70 90 30 30
ASX 74 56 65 50 / 60 80 40 30
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...BEACH HAZARDS STATEMENT THROUGH THIS EVENING FOR MNZ037.
WI...BEACH HAZARDS STATEMENT THROUGH THIS EVENING FOR WIZ001.
LS...SMALL CRAFT ADVISORY UNTIL 10 PM CDT THIS EVENING FOR LSZ141>147.
&&
$$
SHORT TERM...BJT
LONG TERM...MELDE
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
450 AM CDT THU JUN 19 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 413 AM CDT THU JUN 19 2014
ANOTHER ACTIVE NIGHT IS WINDING DOWN...AND FOR THE SECOND NIGHT IN A
ROW WE SAW SOME PRETTY IMPRESSIVE RAINFALL TOTALS RESULT FROM
TRAINING THUNDERSTORMS. TUESDAY NIGHT WAS MANKATO...AND LAST NIGHT
IT WAS WOOD LAKE...WHERE RADAR ESTIMATES SHOW 6 TO 7 INCHES OF RAIN
FELL...AND MUCH OF THAT CAME WITHIN THE FIRST 3 HOURS OF IT STARING
TO RAIN. UNFORTUNATELY...THE ATMOSPHERE THAT HELPED ALLOW THAT TO
HAPPEN WITH PWATS AOA 1.75" AND FREEZING LEVELS ABOVE 15K ARE STILL
IN PLACE AND WILL REMAIN SO UNTIL A COLD FRONT CURRENTLY BACK OVER
ERN SODAK CLEARS THE AREA TONIGHT.
FOR THIS MORNING...THE RAP SHOWS THE LLJ BECOMING BIFURCATED...WITH
ONE SEGMENT SAGGING SE ACROSS IA TOWARD NRN IL...WHILE ANOTHER
SECTION WILL BE ANGLING FROM SRN MN BACK TOWARD ERN NODAK. YOU CAN
SEE THE IMPACTS OF THIS LLJ SLIT OVER THE LAST HOUR ON REGIONAL
RADARS AS ACTIVITY HAS REALLY STARTED TO BECOME FOCUSED OVER NE IA.
THE SEGMENT OF THE LLJ DEVELOPING FARTHER TO THE NORTHWEST IS
HELPING FORCE AN INTENSE LINE OF STORMS CURRENTLY RACING NORTH
ACROSS ERN SODAK. WHAT THIS MEANS FOR THE MPX CWA IS THE CLUSTER OF
STORMS OVER ERN MN WILL BEGIN TO SLOWLY DIMINISH ACROSS WRN WI THIS
MORNING AS IT LOSES ITS LLJ FEED...WITH THE WRN LLJ SEGMENT
FOCUSING ACTIVITY INTO NW MN THIS MORNING. THIS WILL SEND US INTO
ANOTHER PRECIP BREAK PERIOD THAT WILL START BETWEEN 15 AND 18Z.
UNFORTUNATELY...THIS BREAK WILL BE VERY SHORT LIVED. AS THE SODAK
FRONT WORKS INTO WRN MN THIS AFTERNOON...CURRENT EXPECTATION IS THAT
YET ANOTHER LINE OF THUNDERSTORMS WILL DEVELOP NEAR A RWF/AXN LINE
BETWEEN 18Z AND 20Z THAT WILL THEN WORK EAST THROUGH THE OVERNIGHT
HOURS. MOST CAMS SHOW THIS SCENARIO PLAYING OUT...BUT THE SPC AND
ARW WRFS SHOW VERY LITTLE CONVECTION FORMING ALONG THE FRONT.
ALTHOUGH THE CURRENT FORECAST WEIGHS HEAVILY ON THE CONVECTING
MAJORITY...YOU CAN NOT COMPLETELY RULE OUT THE MORE LIMITED
SOLUTIONS DEPENDING ON HOW MUCH CONVECTION TONIGHT CAN OVERTURN THE
ATMOSPHERE. IF ENOUGH OVERTURNING OCCURS...THEN THOSE LIMITED
ACTIVITY SOLUTIONS MAY BE CORRECT. HOWEVER...WITH THE LOSS OF THE
MID LEVEL WARM AIR CAP...PREFER THE SOLUTIONS THAT SHOW ANOTHER
ROUND OF CONVECTION DEVELOPING ALONG THE BOUNDARY THIS AFTERNOON.
FOR THE SEVERE POTENTIAL...THINKING THE THREAT...THOUGH STILL
THERE...WILL NOT BE AS GREAT AS THE LAST COUPLE OF DAYS. ONE BIG
REASON IS THAT THE 5K TO 6K J/KG OF MLCAPE IN THE WARM SECTOR SEEN
TUESDAY AND WEDNESDAY WILL BE REPLACED BY A MUCH MORE MODEST 1K TO
2K J/KG TODAY. IN ADDITION...0-6KM SHEAR WILL BE RANGING FROM 35-40
KTS NEAR THE MN/SD BORDER /CLOSER TO THE UPPER LOW/ TO LESS THAN 20
KTS OVER WRN WI. THE ONE THING THAT IS BETTER TODAY THAN WHAT WE SAW
YESTERDAY ARE THE DYNAMICS AS A NEGATIVELY TILTED TROUGH APPROACHES
WRN MN BY 00Z WITHIN THE RIGHT ENTRANCE REGION OF A 70+ KT LLJ. MORE
BOUNDARY PARALLEL SHEAR THIS AFTERNOON FAVORS A LINEAR CONVECTIVE
MODE. THE MAIN THREAT WILL LIKELY BE DAMAGING STRAIGHT LINE
WINDS...AS THE SMALLER CAPES AND LINEAR MODE SHOULD BOTH HELP TO
SUPPRESS THE HAIL AND TORNADO THREATS /AS COMPARED TO THE LAST
COUPLE OF DAYS/.
THOUGH UNDER NORMAL CIRCUMSTANCES...A FRONT LIKE THIS AFTERNOONS
WOULD NOT TYPICALLY GARNER A FLASH FLOOD WATCH...THIS IS NOT A
TYPICAL SITUATION AS ALL BUT THE NRN TIER OF THE MPX CWA HAS SEEN 4
TO 10 INCHES OF RAIN SINCE FRIDAY ON TOP OF WHAT WAS ALREADY ONE OF
THE WETTEST STARTS TO A YEAR ON RECORD. WITH ONLY A SMALL BREAK IN
THE HEAVY RAINFALL EXPECTED...EXTENDED THE FLASH FLOOD WATCH OUT IN
TIME TO 6Z TONIGHT WEST OF I-35 AND TO 12Z TONIGHT EAST OF I-35. THE
WATCH WAS ALSO EXPANDED NORTH TO INCLUDE THE AREAS THAT HAVE
RECEIVED 3+ INCHES OF RAIN SINCE FRIDAY. ALSO ENDED THE WATCH AT 15Z
FOR THE FAR WRN COUNTIES...AS THE NEXT ROUND OF PRECIPITATION LOOKS
TO START OVER OR JUST EAST OF THOSE COUNTIES...SO CURRENT
EXPECTATIONS ARE THAT THE HEAVY RAIN THREAT WILL SHIFT EAST OF THOSE
COUNTIES AFTER THIS MORNING.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 413 AM CDT THU JUN 19 2014
A DRIER POST FRONTAL AIR MASS IS EXPECTED BY FRIDAY MORNING ACROSS
THE FORECAST AREA WITH A SURFACE ACROSS CENTRAL AND EASTERN WI. WE
THINK THERE IS A DECENT CHANCE AT SUNSHINE AND MODEST W-SW FLOW
COMBINED WITH 16-19 C AT 850 MB TEMPS SHOULD YIELD HIGHS WELL INTO
THE 80S ACROSS MOST OF THE FORECAST AREA /WESTERN WI SHOULD BE A
FEW DEGREES COOLER THAN MN/. BY SATURDAY MORNING THE TROUGH ACROSS
THE NORTHERN HIGH PLAINS SHOULD BUILD SOUTH AND MOISTURE RETURN
SHOULD BRING PWATS BACK UP NEAR 1.5-1.75" IN THE FAR WESTERN
FORECAST AREA. THE RETURN OF WEAK 925-850MB MOISTURE TRANSPORT AND
FGEN BACK ACROSS NORTHERN NE AND EASTERN SD COULD MEAN A FEW
THUNDERSTORMS MAKE IT INTO WESTERN MN ON SATURDAY...BUT THE BETTER
FOCUS IS IN THE STATES THAT BORDER MN TO THE SOUTH AND WEST. THE
PRECIP SIGNAL ON SUNDAY IS MUDDLED WITH A SURFACE TROUGH AND AN
INCREASE IN CONVERGENCE AND OMEGA...BUT WE CAN`T PIN DOWN AN AREA
TO FOCUS POPS/WEATHER AT THIS TIME. AT THIS TIME...THE POTENTIAL
FOR WIDESPREAD HEAVY RAIN IS LOW AND THE OVERALL COVERAGE OF
STORMS SHOULD BE ISOLATED TO SCATTERED. DURING THIS TIME...THE
UPPER LOW THAT HAS BEEN CAMPED OUT TO OUR NORTHWEST DRIFTS SLOWLY
NORTH WITH TIME AND THE LONG WAVE FLOW TURNS MORE ZONAL /SLIGHT
RIDGING/. BOTH THE 19.00Z GFS/ECMWF AND TO SOME DEGREE NAM HAVE A
FAST-MOVING SHORTWAVE EMBEDDED IN THE PSUEDO-ZONAL FLOW ARRIVING
IN THE MID/UPPER MISSISSIPPI RIVER VALLEY BY MONDAY. THE SURFACE
BOUNDARY SHOULD BE STRETCHED OUT ACROSS KS/IA/WI WHICH SHOULD BE
THE MAIN FOCUS FOR THUNDERSTORMS EARLY NEXT WEEK. THE 00Z GFS IS
MUCH MORE AGGRESSIVE IN BRINGING IN COOLER AIR TO THE AREA AND
ASSOCIATED HIGH PRESSURE BY TUESDAY. 00Z GFS NOW SHOWING 850 TEMPS
OF 8C TO 10C FOR TUESDAY AND WEDNESDAY. 00Z EURO AND EVEN THE
PREVIOUS ENSEMBLE RUNS STILL HAS 850 TEMPS OF 12C TO 14C DURING
THAT TIME FRAME. THIS IS A BIG CHANGE FROM PAST GFS RUNS.
SO...MODEL CONSENSUS AND ENSEMBLES ARE THE WAY TO GO. IT IS
IMPORTANT TO NOTE THAT THE ECMWF HAS ALSO SHOWED AGREES IVE COLD
ADVECTION WITH A RUN OR TWO IN THE PAST 2-3 DAYS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 107 AM CDT THU JUN 19 2014
UPPER RIDGE OVER THE MN WI BORDER HAS SLOWED THE EASTWARD
PROGRESSION OF STORMS OVER WRN MN. THEREFORE...SLOWED ARRIVAL OF
SHRA/TSRA LATER THIS MORNING FOR TERMINALS OUT EAST...CLOSER TO
TIMING SEEN WITH THE HRRR. CURRENT THOUGHT PLAYED OUT IN TAFS IS
THAT STORMS WILL SLOWLY WORK EAST DURING THE MORNING...WITH A
TEMPORARY LULL IN ACTIVITY BETWEEN ABOUT 16Z AND 20Z...WITH NEXT
ROUND OF STORMS GOING UP ALONG THE COLD FRONT IN WRN MN BETWEEN 19Z
AND 21Z THAT THEN WORK EAST INTO THE EVENING. FOR THIS POTENTIAL
LINE OF STORMS...WENT WITH PROB30 GROUPS AS HI-RES CAMS ARE
SHOWING A BIT OF SPREAD AS TO HOW MUCH ACTIVITY WILL GO UP ON THE
FRONT ALONG WITH TIMING OF ANY POTENTIAL ACTIVITY. GFSLAMP CIG
FORECASTS THE LAST FEW DAYS HAVE BEEN DOWN RIGHT ATROCIOUS WHEN IT
COMES TO OVER FORECASTING OCCURRENCE OF MVFR CIGS...SO KEPT CONDS
VFR OUTSIDE OF ANY TSRA ACTIVITY.
KMSP...MODERATE TO HIGH CONFIDENCE IN TSRA IMPACTING TERMINAL THIS
MORNING...THOUGH WILL TAKE A WHILE TO GET HERE...MOST LIKELY
BETWEEN 9 AND 12Z. SHOWERS MAY LINGER IN THE AREA MUCH OF THE
MORNING...BEFORE NEXT ROUND OF STORMS IN THE AFTERNOON. CONFIDENCE
IS MODERATE TO HIGH IN STORMS IMPACTING MSP IN THE
AFTERNOON...THOUGH LOWER ON TIMING AT THIS POINT...SO WENT THE
PROB30 ROUTE FOR NOW.
/OUTLOOK FOR KMSP/
FRI...VFR. MVFR ISO SHRA/TSRA POSSIBLE. WINDS SW 10 KTS.
SAT...VFR. MVFR ISO SHRA/TSRA POSSIBLE. WINDS W 10 KTS.
SUN...VFR. MVFR SHRA/TSRA POSSIBLE. WINDS WNW 10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR MNZ057>061-065>069-
073>077-082>085-091>093.
FLASH FLOOD WATCH UNTIL 10 AM CDT THIS MORNING FOR MNZ047-
054>056-064.
FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR MNZ062-063-070-078.
WI...FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR WIZ023>028.
&&
$$
SHORT TERM...MPG
LONG TERM...CLF
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1251 PM CDT Thu Jun 19 2014
.DISCUSSION...
Issued at 410 AM CDT THU JUN 19 2014
Water vapor imagery, as well as 08z RAP analysis indicates a fairly
potent trough over the northern Rockies, with southwesterly flow
over the Central Plains and over the forecast area. A shortwave
trough rotating around the larger low has sparked thunderstorms
across eastern Colorado and central Kansas, which have since moved
into central Nebraska. A decent veered low level jet is currently
nosing into southern Iowa and could produce enough convergence to
produce some early morning convection across southern/central Iowa,
and perhaps northern Missouri. The scenario in which the forecast
area gets any appreciable precip during the morning hours on
Thursday is pretty low confidence, but will cover the potential with
SChc PoPs through 12z and Chc PoPs through 18z. The better chance
for precipitation will come later this afternoon and this evening,
as the axis of a shortwave trough pivots through the area. This will
likely provide enough mid level ascent to produce scattered to
widespread showers and thunderstorms through the afternoon hours. A
warm and very moist atmosphere will lend itself to a high amount of
instability, ranging from 3000 to 3500 J/kg of SB Cape. With the
lack of any really good veering winds with height and lack of any
appreciable speed increase with height the deep layer shear on
Thursday will be rather anemic, generally in the 20 to 30 kt range.
The large instability will lend itself to strong updrafts, but with
the chance for competing updrafts and lack of wind shear feel the
severe threat for Thursday will be marginal. While scattered to
widespread thunderstorms will be possible later this evening, the
severe threat should be relegated to isolated coverage, with gusty
winds, heavy rain, lighting, and perhaps hail up to half dollar in
size will be the main hazards as we go forward into the evening.
Given the potential for scattered to broken clouds through the day,
with perhaps some rain, took temperatures for Thursday afternoon
down a couple degrees, with max temps in the lower to middle 80s.
The trough axis should clear the forecast area by late tonight,
shunting the better lift for precipitation formation further to the
east. Thus have a gradual decrease in PoPs through the overnight
hours, with the best chances across central Missouri toward the
overnight hours on Thursday. Expect Friday and Saturday to remain
mostly dry across the area, however with one or more MCS`s rolling
through the northern plains through the weekend it will remain
possible for the northern half of the CWA to perhaps see the
southern end of any MCS activity through Sunday morning. Latest
ECMWF paints a trough, embedded within the mostly zonal flow,
rolling through the area Sunday afternoon, perhaps bringing the next
best chance for rain Sunday afternoon through the evening. Showers
and thunderstorms could remain in the area through Monday afternoon,
as a cold frontal boundary will eventually slide through the area
erasing the chances for rain. The timing of this front on Monday
will dictate how long the thunderstorms stick around, but the
general feeling at this point is that they should be at least
through western Missouri by Monday evening, moving through central
Missouri by early Tuesday morning. Thereafter, expect a generally
dry forecast with perhaps a few bouts with isolated to scattered
convection through the mid to late week period.
&&
.AVIATION...(For the 18Z TAFS through 18Z Friday Afternoon)
Issued at 1248 PM CDT THU JUN 19 2014
Messy situation with a vorticity max lifting northeast towards west
central MO ahead of a weak cold front extending from western IA
through central KS. Isolated convection already redeveloping ahead
of the vorticity max over east central KS and west central MO.
Too much uncertainty on evolution of convection to use much more than
VCTS for KMCI/KMKC. KSTJ closer to the cold front and thus better
chance for more organized storms later this afternoon.
Should go to VFR conditions and dry with light winds later this
evening.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
DISCUSSION...Leighton
AVIATION...MJ
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
638 AM CDT Thu Jun 19 2014
.DISCUSSION...
Issued at 410 AM CDT THU JUN 19 2014
Water vapor imagery, as well as 08z RAP analysis indicates a fairly
potent trough over the northern Rockies, with southwesterly flow
over the Central Plains and over the forecast area. A shortwave
trough rotating around the larger low has sparked thunderstorms
across eastern Colorado and central Kansas, which have since moved
into central Nebraska. A decent veered low level jet is currently
nosing into southern Iowa and could produce enough convergence to
produce some early morning convection across southern/central Iowa,
and perhaps northern Missouri. The scenario in which the forecast
area gets any appreciable precip during the morning hours on
Thursday is pretty low confidence, but will cover the potential with
SChc PoPs through 12z and Chc PoPs through 18z. The better chance
for precipitation will come later this afternoon and this evening,
as the axis of a shortwave trough pivots through the area. This will
likely provide enough mid level ascent to produce scattered to
widespread showers and thunderstorms through the afternoon hours. A
warm and very moist atmosphere will lend itself to a high amount of
instability, ranging from 3000 to 3500 J/kg of SB Cape. With the
lack of any really good veering winds with height and lack of any
appreciable speed increase with height the deep layer shear on
Thursday will be rather anemic, generally in the 20 to 30 kt range.
The large instability will lend itself to strong updrafts, but with
the chance for competing updrafts and lack of wind shear feel the
severe threat for Thursday will be marginal. While scattered to
widespread thunderstorms will be possible later this evening, the
severe threat should be relegated to isolated coverage, with gusty
winds, heavy rain, lighting, and perhaps hail up to half dollar in
size will be the main hazards as we go forward into the evening.
Given the potential for scattered to broken clouds through the day,
with perhaps some rain, took temperatures for Thursday afternoon
down a couple degrees, with max temps in the lower to middle 80s.
The trough axis should clear the forecast area by late tonight,
shunting the better lift for precipitation formation further to the
east. Thus have a gradual decrease in PoPs through the overnight
hours, with the best chances across central Missouri toward the
overnight hours on Thursday. Expect Friday and Saturday to remain
mostly dry across the area, however with one or more MCS`s rolling
through the northern plains through the weekend it will remain
possible for the northern half of the CWA to perhaps see the
southern end of any MCS activity through Sunday morning. Latest
ECMWF paints a trough, embedded within the mostly zonal flow,
rolling through the area Sunday afternoon, perhaps bringing the next
best chance for rain Sunday afternoon through the evening. Showers
and thunderstorms could remain in the area through Monday afternoon,
as a cold frontal boundary will eventually slide through the area
erasing the chances for rain. The timing of this front on Monday
will dictate how long the thunderstorms stick around, but the
general feeling at this point is that they should be at least
through western Missouri by Monday evening, moving through central
Missouri by early Tuesday morning. Thereafter, expect a generally
dry forecast with perhaps a few bouts with isolated to scattered
convection through the mid to late week period.
&&
.AVIATION...(For the 12Z TAFS through 12Z Friday Morning)
Issued at 634 AM CDT THU JUN 19 2014
Southerly winds will pick up through the day, bringing gusts up to 20
25 knots. Early morning could see a few isolated showers pop up near
the terminals, but expect the bulk of that activity to become more
established farther east. The better chance for precipitation will
come later this afternoon and this evening as scattered storms form
near and at the terminals. Expect at least a few hours of storms to
affect the terminals with periods of heavy rain and erratic, gusty
winds. The bulk of that activity should wane by the late evening, and
move toward the southeast, away from the terminals. Expect a weak
boundary to come into play tonight as winds may become calm and
variable for the final 8-10 hours of this forecast period.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
DISCUSSION...Leighton
AVIATION...Leighton
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
411 AM CDT Thu Jun 19 2014
&&
.DISCUSSION...
Issued at 410 AM CDT THU JUN 19 2014
Water vapor imagery, as well as 08z RAP analysis indicates a fairly
potent trough over the northern Rockies, with southwesterly flow
over the Central Plains and over the forecast area. A shortwave
trough rotating around the larger low has sparked thunderstorms
across eastern Colorado and central Kansas, which have since moved
into central Nebraska. A decent veered low level jet is currently
nosing into southern Iowa and could produce enough convergence to
produce some early morning convection across southern/central Iowa,
and perhaps northern Missouri. The scenario in which the forecast
area gets any appreciable precip during the morning hours on
Thursday is pretty low confidence, but will cover the potential with
SChc PoPs through 12z and Chc PoPs through 18z. The better chance
for precipitation will come later this afternoon and this evening,
as the axis of a shortwave trough pivots through the area. This will
likely provide enough mid level ascent to produce scattered to
widespread showers and thunderstorms through the afternoon hours. A
warm and very moist atmosphere will lend itself to a high amount of
instability, ranging from 3000 to 3500 J/kg of SB Cape. With the
lack of any really good veering winds with height and lack of any
appreciable speed increase with height the deep layer shear on
Thursday will be rather anemic, generally in the 20 to 30 kt range.
The large instability will lend itself to strong updrafts, but with
the chance for competing updrafts and lack of wind shear feel the
severe threat for Thursday will be marginal. While scattered to
widespread thunderstorms will be possible later this evening, the
severe threat should be relegated to isolated coverage, with gusty
winds, heavy rain, lighting, and perhaps hail up to half dollar in
size will be the main hazards as we go forward into the evening.
Given the potential for scattered to broken clouds through the day,
with perhaps some rain, took temperatures for Thursday afternoon
down a couple degrees, with max temps in the lower to middle 80s.
The trough axis should clear the forecast area by late tonight,
shunting the better lift for precipitation formation further to the
east. Thusly have a gradual decrease in PoPs through the overnight
hours, with the best chances across central Missouri toward the
overnight hours on Thursday. Expect Friday and Saturday to remain
mostly dry across the area, however with one or more MCS`s rolling
through the northern plains through the weekend it will remain
possible for the northern half of the CWA to perhaps see the
southern end of any MCS activity through Sunday morning. Latest
ECMWF paints a trough, embedded within the mostly zonal flow,
rolling through the area Sunday afternoon, perhaps bringing the next
best chance for rain Sunday afternoon through the evening. Showers
and thunderstorms could remain in the area through Monday afternoon,
as a cold frontal boundary will eventually slide through the area
erasing the chances for rain. The timing of this front on Monday
will dictate how long the thunderstorms stick around, but the
general feeling at this point is that they should be at least
through western Missouri by Monday evening, moving through central
Missouri by early Tuesday morning. Thereafter, expect a generally
dry forecast with perhaps a few bouts with isolated to scattered
convection through the mid to late week period.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday Night)
Issued at 1205 AM CDT THU JUN 19 2014
VFR conditions continue for this forecast. Winds have decoupled some
so will strip out gusts till later Thursday morning. As speculated
in the last discussion the KS convection is waning and expect this
trend to continue through the night. Hi-Res models continue to back
off on introducing convection to the terminals and favor their
solutions. Continue to ignore the NAM output. Think convective
chances will gradually ramp up with afternoon heating and opted to
introduce a TEMPO group late in the day at peak heating.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
DISCUSSION...Leighton
AVIATION...MJ
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1145 PM CDT Wed Jun 18 2014
.UPDATE:
Issued at 906 PM CDT Wed Jun 18 2014
Convection across northern IL this evening along and north of a
front. the NAM model tries to sag this front southward late
tonight as a surface ridge builds southward into the Great Lakes
region. The latest NAM model run appears too far south with its
QPF tonight. The latest HRRR keeps the convection just north and
northeast of our forecast area until 12z Thursday. Still think we
may have at least isolated showers/storms across northeast MO and
west central IL late tonight as additional convection continues to
develop further southward across eastern IA and northern IL. Low
temperatures tonight should be similar to last night, about 10
degrees above normal, with continued southerly winds and relatively
high surface dew points.
GKS
&&
.SHORT TERM: (Through Late Tonight)
Issued at 324 PM CDT Wed Jun 18 2014
Convective trends are the primary concern for the short term. The
outflow boundary from last night`s MCS is becoming weaker and more
diffuse with time, think it extends from near Galesburg IL to near
Burlington IA northwest to near Washington IA. The airmass along
and south of the boundary is uncapped or nearly so, and is sporting
MLCAPE values of 3500 J/kg. It looks like the majority of the
convergence is north of our area, but there are a few cells which
are developing in our area back across southwest Illinois in an area
of agitated CU...possibly caused by southward propagating gravity
waves from earlier convection across Illinois. Expect these
isolated cells to gradually diminish as we lose diurnal heating, but
there may be some additional development along the outflow boundary
in southeast Iowa and west central Illinois. If strong enough
storms can form, and if they can get a sufficiently strong cold pool
to develop, they could produce a south-southwestward propagating
cluster of storms, riding the instability and low level jet into
northeast Missouri and the Quincy area. 700mb temperatures were +10
to +12 C this morning just south of the outflow boundary, with no
cooler air on the horizon, so would expect any storms that do form
to have a difficult time getting much further south than perhaps
Moberly, or Hannibal. With that much instability available, severe
storms are possible, but low level wind shear/helicity are lacking
so would expect the primary threat to be damaging wind and/or large
hail.
Carney
.LONG TERM: (Thursday through Next Wednesday)
Issued at 352 PM CDT Wed Jun 18 2014
Mass fields in the models are in generally good agreement through
the end of the week ejecting the cut off low currently camping out
over western Montana northeast into Manitoba or Saskatchewan by 00Z
Saturday. This will flatten out the upper level ridge and most
likely allow for a general increase in convection coverage
(primarily over central and northeast Missouri) Thursday and Friday
afternoon. Temperatures on Thursday and Friday should be similar to
what we`ve been experiencing the past few days, upper 80s and low
90s. The exception to this rule may be that afternoon convection
could locally suppress temperatures.
Convective trends continue to be a challenge out in the medium range
with the flow staying quasi-zonal. The GFS looks horribly
contaminated with grid-scale convective feedback. It generates
multiple small vortmaxes and omega bullseyes starting Saturday and
continuing through the end of the forecast period. The ECMWF looks
more reasonable with the quasi-zonal pattern giving way to a trof
moving across the mountains into the Great Plains Sunday night and
Monday. While I can`t rule out convection through the weekend, it
looks like the best chances for rain will hold off until early next
week. Temperatures will likely stay on the warm side of climatology
through the weekend, but cool slightly to near normal levels by
midweek as the trof moves into the area.
Carney
&&
.AVIATION: (For the 06z TAFs through 06z Thursday Night)
Issued at 1122 PM CDT Wed Jun 18 2014
Quasi-stationary front is currently oriented northwest to
southeast across southern Minnesota to east-central Illinois.
Convection tonight has developed along and on the cool side of the
boundary. Models develop convection further to the south and west
oveernight as effective boundary also travels that way due to
outflow boundary/high pressure builds in over the Great Lakes.
HRRR keeps convection out of area to the north and east through
tomorrow morning and followed closely as it initialized convection
well whereas NAM/GFS were too far south and west with
precipitation ending at 0600 UTC tonight. Did introduce a VCTS
group however for late tomorrow afternoon/evening as latest 0000
UTC NAM/GFS advect a ridge-running shortwave trough which should
help initiate some convection within a very unstable atmosphere.
Outside of any thunderstorms...TAF sites will remain VFR with
south/southwest winds.
Specifics for KSTL:
Quasi-stationary front is currently oriented northwest to
southeast across southern Minnesota to east-central Illinois.
Convection tonight has developed along and on the cool side of the
boundary. Models develop convection further to the south and west
oveernight as effective boundary also travels that way due to
outflow boundary/high pressure builds in over the Great Lakes.
HRRR keeps convection well to the north and east of KSTL through
tomorrow morning and followed closely as it initialized convection
well this evening whereas NAM/GFS were too far south and west with
precipitation ending at 0600 UTC. Did introduce a VCTS group
however for late tomorrow afternoon/evening as latest 0000 UTC
NAM/GFS advect a ridge-running shortwave trough which should help
initiate some convection within a very unstable atmosphere.
Outside of any thunderstorms...terminal is expected to remain VFR
with south/southwest winds.
Gosselin
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BILLINGS MT
1012 AM MDT THU JUN 19 2014
.UPDATE...
SLOW MOVING DEEP UPPER LOW OVER NORTHERN MONTANA THIS MORNING.
WEAK ENERGY WAS WRAPPING AROUND THE LOW AND PRODUCING WEAK SHOWERS
OVER FROM BILLINGS NORTHWEST. THE SHOWERS HAVE BEEN WEAKENING AS
THE MORNING WEARS ON. MORE ENERGY UPSTREAM WRAPPING AROUND THE LOW
WAS PRODUCING SHOWERS FROM LEWISTOWN TO GREAT FALLS TO CUT BANK.
THE UPPER LOW IS PROGGED TO VERY SLOWLY DRIFT NORTHEAST AND THUS
THE ENERGY WILL BRUSH THE NORTHERN ZONES TODAY. HAVE ADJUSTED POPS
SLIGHTLY TO ACCOUNT FOR MORNING ACTIVITY AND HIT THE NORTHERN
ZONES A LITTLE HARDER TODAY. STRONG SOUTHWEST WINDS AT LIVINGSTON
THIS MORNING WITH GUSTS TO 45 MPH. THE GRADIENT WEAKENS THIS
AFTERNOON AND MIXING WILL TAKE OVER. WOULD EXPECT THE WINDS TO
TURN MORE WESTERLY BUT REMAIN STRONG...WHICH IS HANDLED VERY WELL
IN THE EXISTING FORECAST. THE REST OF THE FORECAST LOOKS IN GOOD
SHAPE. TWH
&&
.SHORT TERM...VALID FOR TDY AND FRI...
UPPER LOW CONTINUES TO SPIN OVER NORTH CENTRAL MT. TROWAL ON WEST
SIDE OF LOW IS WRAPPING SOME PCPN IN OUR FAR NW...MAINLY OVER THE
MTNS AS LOW LEVELS ARE DOWNSLOPED. AREA OF PV WILL DROP OUT OF
SOUTHERN ALBERTA AND OFFER DECENT Q-VECTOR CONVERGENCE AS IT
ROTATES AROUND THE LOW THIS MORNING INTO THE AFTERNOON...SO EXPECT
SHOWER COVERAGE TO BECOME MORE WIDESPREAD ESPECIALLY ACROSS OUR
NORTH. WE SHOULD ALSO SEE SOME WEAK CONVECTIVE DEVELOPMENT THIS
AFTERNOON AND EARLY EVENING PER THE CYCLONIC FLOW AND RELATIVELY
COLD AIR ALOFT...THOUGH IT SHOULD BE NOTED THAT WE WILL BE
EXPERIENCING HEIGHT RISES THRU THE DAY AS THE LOW BEGINS TO PUSH
SLOWLY EAST. THUS AS WE WARM THE MID LEVELS EXPECT AFTERNOON CAPE
VALUES TO BE VERY MODEST. OTHER FEATURE OF INTEREST TODAY IS
ENERGY PUSHING ACROSS WYOMING. THERE IS FAIRLY STRONG UPPER
DIVERGENCE OCCURRING CURRENTLY IN FAR SOUTHEAST MT IN RRQ OF 110
KT H3 JET. THIS ALONG WITH AN AREA OF ELEVATED INSTABILITY AND
850MB CONVERGENCE MAY YIELD A FEW SHOWERS OR EVEN TSTMS IN THE
CARTER COUNTY AREA EARLY THIS MORNING...AS THE HRRR AND RAP ARE
BOTH SUGGESTING. ALSO... REMARKABLY FOR MID JUNE...LIVINGSTON IS
GAPPING WITH WIND GUSTS HAVING ALREADY TOPPED 50 MPH TONIGHT. WE
SHOULD NOT SEE HIGHER GUSTS THAN THIS...AND BY 15Z LOW LEVELS WILL
START TO BECOME MIXED...BUT NONETHELESS HAVE RAISED WIND SPEEDS
ALONG OUR WESTERN FOOTHILLS TO ACCOUNT FOR THIS PERIOD OF GAP
FLOW. MIXED WINDS WILL REMAIN GUSTY AT LIVINGSTON THROUGH THE
AFTERNOON AND TO A LESSER EXTENT THROUGH TONIGHT AS DOWNSLOPE
GRADIENTS REMAIN IN PLACE. FINALLY...TEMPS WILL BEGIN TO CLIMB
TODAY PER THE WARMING MID LEVEL TEMPS AND GOOD MIXING. SHOULD SEE
HIGHS INTO THE LOWER TO MID 70S...AND HAVE TWEAKED EXPECTED HIGHS
UP A BIT.
SHOWER CHANCES WILL DIMINISH TONIGHT AS UPPER LOW EXITS...
FINALLY...AND RIDGE BUILDS FROM THE WEST. FRIDAY WILL BE A MOSTLY
DRY AND WARMER DAY WITH TEMPS INTO THE UPPER 70S TO LOWER 80S...
THE WARMEST WE HAVE SEEN IN OVER A WEEK. BACKING MID LEVEL FLOW
WITH WEAK PACIFIC ENERGY SHOULD BE ENOUGH FOR SOME LATE DAY WEAK
CONVECTION IN OUR WEST...WITH STEEP LOW LEVEL LAPSE RATES
SUGGESTING SOME DECENT WIND GUSTS WITH ANY STORMS NEAR SUCH PLACES
AS LIVINGSTON AND HARLOWTON. TONIGHTS MODEL RUNS HAVE TRENDED A
BIT STRONGER WITH THE PASSAGE OF A NIGHTTIME SHORTWAVE AND SFC
COLD FRONT...SO HAVE ADDED SLIGHT POPS ACROSS OUR WEST AND NORTH
THRU LATE FRIDAY NIGHT. JKL
.LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED...
OVERALL CHANGE IN THE EXTENDED FORECAST WAS TOWARD A SLIGHTLY
COOLER SOLUTION THAN PREVIOUSLY ADVERTISED. THE MAIN REASON FOR
THIS TREND TOWARD SLIGHTLY COOLER TEMPERATURES THIS WEEKEND IS
DRIVEN BY MORE VIGOROUS SHORTWAVE PASSAGES. FOR EARLY TO MIDDLE
NEXT WEEK...MODEL SOLUTIONS DIVERGE ON THE OVERALL PATTERN. THE
GFS BUILDS IN RIDGING...WHILE THE EC AND CANADIAN HAVE TAKEN A
SHARP TREND TOWARD HOLDING A BACKDOOR COLD FRONT INTO THE FORECAST
AREA. DECIDED TO LEAN THE FORECAST TOWARD THE EC/GEM SOLUTIONS IN
THE EXTENDED...HOWEVER...WILL NEED TO KEEP AN EYE ON WHETHER THE
GFS TRENDS IN THAT DIRECTION OVER THE NEXT FEW MODEL CYCLES.
AS FOR THIS WEEKEND...SATURDAY AND SUNDAY BOTH LOOK TO BE VERY
PLEASANT DAYS WITH SOME SCATTERED SHOWERS AND THUNDERSTORMS
POSSIBLE. ON SATURDAY...COOLED TEMPERATURES SLIGHTLY AS THE
APPROACHING SHORTWAVE PULLS THE LOW-LEVEL WINDS AROUND TO THE EAST
BY SATURDAY AFTERNOON. BETWEEN THE EASTERLY FLOW BRINGING IN MORE
MOISTURE AND THE APPROACHING SHORTWAVE TROUGH...EXPECT TO SEE
SHOWERS DEVELOP SATURDAY EVENING. INSTABILITY LOOKS VERY MARGINAL
AT THIS POINT...SO ONLY EXPECTING SOME ISOLATED THUNDER.
COOLED HIGH TEMPERATURES TO THE MID TO UPPER 70S ON SUNDAY...GIVEN
A BETTER SURGE OF COOL AIR BEHIND THE MORE VIGOROUS SHORTWAVE. 700MB
TEMPERATURES COOL FROM +8C ON SATURDAY AFTERNOON...TO +4C ON
SUNDAY AFTERNOON. WITH THE TROUGH OVERHEAD SUNDAY...INSTABILITY
WILL BE BETTER...WITH SHOWALTER INDICES -1 TO -2 OVER SOUTH
CENTRAL MONTANA. THUS EXPECT TO SEE A LITTLE BETTER SHOWER AND
THUNDERSTORM COVERAGE ON SUNDAY. OVERALL...DONT SEE MUCH CONCERN
FOR ANY SEVERE WEATHER AT THIS POINT...DUE TO MARGINAL
INSTABILITY. CHURCH
&&
.AVIATION...
SOME ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WITH AN
ASSOCIATED MVFR CONDITION WILL BE POSSIBLE TODAY.
OTHERWISE...PARTLY SUNNY SKIES WITH VFR CONDITIONS WILL PREVAIL.
IN ADDITION...SOME GUSTY SOUTHWEST WINDS OF 30-35KTS WILL BE
LIKELY FOR THE KLVM AREA THROUGHOUT THE DAY. HOOLEY
&&
.PRELIMINARY POINT TEMP/POPS...
TDY FRI SAT SUN MON TUE WED
-------------------------------------------------------
BIL 075 054/083 056/081 056/076 055/079 056/083 056/083
3/T 20/U 22/T 23/T 33/T 33/T 33/T
LVM 073 048/080 047/078 048/075 048/077 049/081 050/079
4/T 12/T 23/T 33/T 33/T 33/T 33/T
HDN 076 050/084 052/084 054/079 053/080 054/085 056/085
3/T 20/U 12/T 23/T 33/T 33/T 33/T
MLS 074 054/083 058/083 058/078 057/080 058/083 060/085
3/T 31/U 21/U 22/T 22/T 22/T 11/B
4BQ 074 051/083 054/082 056/078 055/079 054/082 055/085
2/T 21/U 12/T 33/T 32/T 22/T 12/T
BHK 072 052/080 055/080 055/075 054/076 054/079 056/082
2/T 31/U 12/T 22/T 22/T 22/T 11/U
SHR 073 047/082 050/081 052/075 051/077 052/081 053/082
2/T 11/U 02/T 23/T 33/T 34/T 43/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BILLINGS MT
317 AM MDT THU JUN 19 2014
.SHORT TERM...VALID FOR TDY AND FRI...
UPPER LOW CONTINUES TO SPIN OVER NORTH CENTRAL MT. TROWAL ON WEST
SIDE OF LOW IS WRAPPING SOME PCPN IN OUR FAR NW...MAINLY OVER THE
MTNS AS LOW LEVELS ARE DOWNSLOPED. AREA OF PV WILL DROP OUT OF
SOUTHERN ALBERTA AND OFFER DECENT Q-VECTOR CONVERGENCE AS IT
ROTATES AROUND THE LOW THIS MORNING INTO THE AFTERNOON...SO EXPECT
SHOWER COVERAGE TO BECOME MORE WIDESPREAD ESPECIALLY ACROSS OUR
NORTH. WE SHOULD ALSO SEE SOME WEAK CONVECTIVE DEVELOPMENT THIS
AFTERNOON AND EARLY EVENING PER THE CYCLONIC FLOW AND RELATIVELY
COLD AIR ALOFT...THOUGH IT SHOULD BE NOTED THAT WE WILL BE
EXPERIENCING HEIGHT RISES THRU THE DAY AS THE LOW BEGINS TO PUSH
SLOWLY EAST. THUS AS WE WARM THE MID LEVELS EXPECT AFTERNOON CAPE
VALUES TO BE VERY MODEST. OTHER FEATURE OF INTEREST TODAY IS
ENERGY PUSHING ACROSS WYOMING. THERE IS FAIRLY STRONG UPPER
DIVERGENCE OCCURRING CURRENTLY IN FAR SOUTHEAST MT IN RRQ OF 110
KT H3 JET. THIS ALONG WITH AN AREA OF ELEVATED INSTABILITY AND
850MB CONVERGENCE MAY YIELD A FEW SHOWERS OR EVEN TSTMS IN THE
CARTER COUNTY AREA EARLY THIS MORNING...AS THE HRRR AND RAP ARE
BOTH SUGGESTING. ALSO... REMARKABLY FOR MID JUNE...LIVINGSTON IS
GAPPING WITH WIND GUSTS HAVING ALREADY TOPPED 50 MPH TONIGHT. WE
SHOULD NOT SEE HIGHER GUSTS THAN THIS...AND BY 15Z LOW LEVELS WILL
START TO BECOME MIXED...BUT NONETHELESS HAVE RAISED WIND SPEEDS
ALONG OUR WESTERN FOOTHILLS TO ACCOUNT FOR THIS PERIOD OF GAP
FLOW. MIXED WINDS WILL REMAIN GUSTY AT LIVINGSTON THROUGH THE
AFTERNOON AND TO A LESSER EXTENT THROUGH TONIGHT AS DOWNSLOPE
GRADIENTS REMAIN IN PLACE. FINALLY...TEMPS WILL BEGIN TO CLIMB
TODAY PER THE WARMING MID LEVEL TEMPS AND GOOD MIXING. SHOULD SEE
HIGHS INTO THE LOWER TO MID 70S...AND HAVE TWEAKED EXPECTED HIGHS
UP A BIT.
SHOWER CHANCES WILL DIMINISH TONIGHT AS UPPER LOW EXITS...
FINALLY...AND RIDGE BUILDS FROM THE WEST. FRIDAY WILL BE A MOSTLY
DRY AND WARMER DAY WITH TEMPS INTO THE UPPER 70S TO LOWER 80S...
THE WARMEST WE HAVE SEEN IN OVER A WEEK. BACKING MID LEVEL FLOW
WITH WEAK PACIFIC ENERGY SHOULD BE ENOUGH FOR SOME LATE DAY WEAK
CONVECTION IN OUR WEST...WITH STEEP LOW LEVEL LAPSE RATES
SUGGESTING SOME DECENT WIND GUSTS WITH ANY STORMS NEAR SUCH PLACES
AS LIVINGSTON AND HARLOWTON. TONIGHTS MODEL RUNS HAVE TRENDED A
BIT STRONGER WITH THE PASSAGE OF A NIGHTTIME SHORTWAVE AND SFC
COLD FRONT...SO HAVE ADDED SLIGHT POPS ACROSS OUR WEST AND NORTH
THRU LATE FRIDAY NIGHT.
JKL
.LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED...
OVERALL CHANGE IN THE EXTENDED FORECAST WAS TOWARD A SLIGHTLY
COOLER SOLUTION THAN PREVIOUSLY ADVERTISED. THE MAIN REASON FOR
THIS TREND TOWARD SLIGHTLY COOLER TEMPERATURES THIS WEEKEND IS
DRIVEN BY MORE VIGOROUS SHORTWAVE PASSAGES. FOR EARLY TO MIDDLE
NEXT WEEK...MODEL SOLUTIONS DIVERGE ON THE OVERALL PATTERN. THE
GFS BUILDS IN RIDGING...WHILE THE EC AND CANADIAN HAVE TAKEN A
SHARP TREND TOWARD HOLDING A BACKDOOR COLD FRONT INTO THE FORECAST
AREA. DECIDED TO LEAN THE FORECAST TOWARD THE EC/GEM SOLUTIONS IN
THE EXTENDED...HOWEVER...WILL NEED TO KEEP AN EYE ON WHETHER THE
GFS TRENDS IN THAT DIRECTION OVER THE NEXT FEW MODEL CYCLES.
AS FOR THIS WEEKEND...SATURDAY AND SUNDAY BOTH LOOK TO BE VERY
PLEASANT DAYS WITH SOME SCATTERED SHOWERS AND THUNDERSTORMS
POSSIBLE. ON SATURDAY...COOLED TEMPERATURES SLIGHTLY AS THE
APPROACHING SHORTWAVE PULLS THE LOW-LEVEL WINDS AROUND TO THE EAST
BY SATURDAY AFTERNOON. BETWEEN THE EASTERLY FLOW BRINGING IN MORE
MOISTURE AND THE APPROACHING SHORTWAVE TROUGH...EXPECT TO SEE
SHOWERS DEVELOP SATURDAY EVENING. INSTABILITY LOOKS VERY MARGINAL
AT THIS POINT...SO ONLY EXPECTING SOME ISOLATED THUNDER.
COOLED HIGH TEMPERATURES TO THE MID TO UPPER 70S ON SUNDAY...GIVEN
A BETTER SURGE OF COOL AIR BEHIND THE MORE VIGOROUS SHORTWAVE. 700MB
TEMPERATURES COOL FROM +8C ON SATURDAY AFTERNOON...TO +4C ON
SUNDAY AFTERNOON. WITH THE TROUGH OVERHEAD SUNDAY...INSTABILITY
WILL BE BETTER...WITH SHOWALTER INDICES -1 TO -2 OVER SOUTH
CENTRAL MONTANA. THUS EXPECT TO SEE A LITTLE BETTER SHOWER AND
THUNDERSTORM COVERAGE ON SUNDAY. OVERALL...DONT SEE MUCH CONCERN
FOR ANY SEVERE WEATHER AT THIS POINT...DUE TO MARGINAL
INSTABILITY.
CHURCH
&&
.AVIATION...
SOME ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED
TODAY...MAINLY ALONG AND NORTH OF A LINE FROM KLVM TO KBIL TO
KMLS. MVFR CONDITIONS ARE EXPECTED IN THOSE SHOWERS AND
THUNDERSTORMS...ALONG WITH MOUNTAIN OBSCURATIONS. WE ALSO EXPECT
THERE A IS A CHANCE FOR SOME PATCH FOG NEAR KMLS AND KBHK THROUGH
15Z THIS MORNING. OTHERWISE...EXPECT MAINLY VFR CONDITIONS TO
PREVAIL AT ALL TAF SITES TODAY. WINDS NEAR LIVINGSTON WILL REMAIN
STRONG THIS MORNING...WITH GUSTS TO AROUND 40 KTS...THEN CONTINUE
WITH GUSTS AROUND 30 TO 35 KTS THROUGH THIS AFTERNOON.
CHURCH
&&
.PRELIMINARY POINT TEMP/POPS...
TDY FRI SAT SUN MON TUE WED
-------------------------------------------------------
BIL 075 054/083 056/081 056/076 055/079 056/083 056/083
3/T 20/U 22/T 23/T 33/T 33/T 33/T
LVM 073 048/080 047/078 048/075 048/077 049/081 050/079
4/T 12/T 23/T 33/T 33/T 33/T 33/T
HDN 076 050/084 052/084 054/079 053/080 054/085 056/085
3/T 20/U 12/T 23/T 33/T 33/T 33/T
MLS 074 054/083 058/083 058/078 057/080 058/083 060/085
4/T 31/U 21/U 22/T 22/T 22/T 11/B
4BQ 074 051/083 054/082 056/078 055/079 054/082 055/085
2/T 21/U 12/T 33/T 32/T 22/T 12/T
BHK 072 052/080 055/080 055/075 054/076 054/079 056/082
2/T 31/U 12/T 22/T 22/T 22/T 11/U
SHR 073 047/082 050/081 052/075 051/077 052/081 053/082
2/T 11/U 02/T 23/T 33/T 34/T 43/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
622 AM CDT THU JUN 19 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 329 AM CDT THU JUN 19 2014
PACIFIC HIGH PRESSURE AND DRIER MORE STABLE AIR BUILDS INTO THE FCST
AREA IN THE WAKE OF THE WEDNESDAY NIGHT MCS. THIS SHOULD DETER STORM
DEVELOPMENT UNTIL AT LEAST 06Z TONIGHT. THEREAFTER...THE NAM SHOWS
THIS HIGH MOVING INTO MISSOURI AND RETURN MOISTURE MOVING UP THE
SRN/CNTL HIGH PLAINS AT THE H850-700MB LEVELS. THE MODEL SHOWS SOME
LIGHT QPF ACROSS SWRN NEB AND ELEVATED CAPE AROUND 700 J/KG
SUGGESTING A SMALL CUSTER OF TSTMS MAY DEVELOP ACROSS THE SOUTHWEST
AS K INDICES RISE TO 35 TO 40C. THE NMM AND ARF MODELS SHOW A FEW
TSTMS DEVELOPING ALSO BUT THESE ARE FARTHER SOUTH ACROSS COLO/KS.
SO THE NAM MAY BE TOO FAST. THE FORECAST IS DRY TODAY AND TONIGHT
PENDING THE LATER MODEL DATA.
HIGHS TODAY RISE TO JUST THE 70S TO NEAR 80 WITH THE VERY COOL
PACIFIC HIGH PRESSURE SYSTEM MOVING ACROSS THE FCST AREA. FULL SUN
IS EXPECTED THIS AFTERNOON. LOWS TONIGHT FALL INTO THE 50S TO LOWER
60S TONIGHT AS THE HIGH MOVES SOUTHEAST.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 329 AM CDT THU JUN 19 2014
THUNDERSTORM CHANCES RETURN FRIDAY THROUGH THE WEEKEND ACROSS
WESTERN AND NORTH CENTRAL NEBRASKA. GULF MOISTURE WILL QUICKLY
SPREAD NORTHWEST INTO THE AREA FRIDAY MORNING...AND CONDITIONS BY
AFTERNOON WILL BECOME QUITE UNSTABLE ACROSS MOST OF THE AREA.
MID LEVEL FORCING WILL BE WEAK...BUT CONVERGENCE NEAR A WEAK
SURFACE TROUGH OF LOW PRESSURE FROM AROUND VALENTINE TO OGALLALA
SHOULD BE ENOUGH TO INITIATE SCATTERED AFTERNOON THUNDERSTORMS.
THESE LIKELY WILL PERSIST INTO FRIDAY EVENING AS THEY MOVE EAST
AIDED BY A MODEST SOUTHERLY LOW LEVEL JET.
A WARM FRONT WILL EXTEND ACROSS FAR NORTHERN NEBRASKA OR
SOUTHERN/SOUTHEAST SOUTH DAKOTA SATURDAY AFTERNOON. VERY UNSTABLE
CONDITIONS WILL DEVELOP ONCE AGAIN NEAR THE FRONT...AND MODEST
BULK SHEAR PRESENT OF 30 PLUS KTS SPELLS MORE THUNDERSTORM
ACTIVITY. MID LEVEL FORCING AGAIN NOT GREAT...SO ACTIVITY MAY
REMAIN SCATTERED...BUT SEVERE STORMS SEEM POSSIBLE GIVEN SUCH
STRONG INSTABILITY AND DECENT AMOUNTS OF SHEAR. THE BEST CHANCE
FOR SEVERE WOULD BE RIGHT NEAR THE WARM FRONT...AND LATER
FORECASTS WILL BETTER DETERMINE THE LOCATION.
A SOMEWHAT MORE CONCENTRATED CLUSTER OF STORMS MAY EVOLVE SUNDAY
AFTERNOON AND NIGHT...AHEAD OF A HEALTHY SHORTWAVE PUSHING EAST
THROUGH THE NORTHERN ROCKIES. STORMS SHOULD INITIATE ACROSS THE
PANHANDLE LATE IN THE AFTERNOON...AND THEN MOVE EAST SOUTHEAST
INTO SOUTHWEST AND CENTRAL NEBRASKA SUNDAY NIGHT.
PERIODIC CHANCES FOR SHOWERS/STORMS WILL CONTINUE INTO NEXT WORK
WEEK. HARD TO PIN DOWN EXACT TIMING OF WAVES AND ASSOCIATED PRECIP
AT THIS POINT. IT DOES APPEAR THE OVERALL SEVERE THREAT MAY WANE
SOME AS MID LEVEL FLOW DECREASES. TEMPERATURES WILL REMAIN
SEASONAL...WITH NO HOT WEATHER EXPECTED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 622 AM CDT THU JUN 19 2014
VFR IS EXPECTED ALL AREAS TODAY AND TONIGHT.
PACIFIC HIGH PRESSURE WILL BUILD THROUGH THE FCST AREA TODAY WITH
LIGHT SOUTH WINDS DEVELOPING TONIGHT. THE NAM SUGGESTS THE
POTENTIAL FOR ISOLATED TSTMS ACROSS SWRN NEB TOWARD 12Z FRIDAY BUT
IT IS THE ONLY MODEL SHOWING THIS. THE BEST FORECAST FOR THE TIME
BEING IS VFR THRU 12Z FRIDAY PENDING LATER SOLNS OF THE RAP MODEL
WHICH WAS VERY ACCURATE FORECASTING TSTM DEVELOPMENT WEDNESDAY NIGHT.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...TAYLOR
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
733 AM EDT THU JUN 19 2014
.SYNOPSIS...
A RIDGE OF HIGH PRESSURE WILL BUILD SOUTHEAST FROM CANADA PUTTING
OUR REGION IN A NORTHERLY FLOW OF FAIR AND DRY WEATHER THROUGH
THIS WEEKEND. TEMPERATURES WILL BE A FEW DEGREES COOLER THAN
AVERAGE THROUGH SATURDAY MORNING THEN A WARMING TREND INTO NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 705 AM EDT THURSDAY...SKIES WILL BE PARTLY TO MOSTLY SUNNY
TODAY FROM A STEADY NORTH NORTHEST FLOW OF SUBSIDING DRY AIR AND
COOLER TEMPS FROM TRAJECTORIES COMING RIGHT FROM JAMES BAY. 850
TEMPS WILL BE FALL SLIGHTLY FROM AROUND 10C DOWN TO ABOUT 7C IN
THE NORTH THIS AFTERNOON. THE RAP SHOWS THIS GRADIENT POISED JUST
NORTH THE BORDER EARLY THIS MORNING. THIS SHOULD YIELD HIGH TEMPS
IN THE 70S MOST PLACES, MILDEST IN THE MID TO UPPER 70S SOUTHERN
AND LOWER VALLEY LOCATIONS. THERE WILL BE SOME THIN FAIR WEATHER
CUMULUS CLOUDS TODAY ESPECIALLY NORTHERN MTNS WITH COLD ADVECTION,
EVAPOTRANSPIRATION, AND VORT MAX SWINGING THROUGH EARLY AFTERNOON.
WINDS WILL BE FROM THE NORTH NORTHWEST 10 TO 20 MPH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
AS OF 441 AM EDT THURSDAY...NORTHERLY FLOW CONTINUES THROUGH
SATURDAY WITH MAINLY SCATTERED DIURNAL DRIVEN CUMULUS CLOUDS AND
MOSTLY CLEAR NIGHTS. 850 TEMPS 5-8C FRIDAY AND WARMING TO 9-10C
SATURDAY SO HIGH TEMPS UPPER 60S TO LOWER 70S FRIDAY AND IN THE
70S ON SATURDAY. LOW TEMPS MOSTLY IN THE 40S, EXCEPT A FEW UPPER
30S IN THE NORMALLY COLD SHELTERED SPOTS. DAYTIME WINDS WILL BE
FROM THE NORTH NORTHWEST 10 TO 20 MPH AND LIGHT AT NIGHT.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 340 AM EDT THURSDAY...QUIET STRETCH OF DRY/SEASONABLE
WEATHER CONDITIONS IS EXPECTED TO EXTEND THROUGH MONDAY
NIGHT...FOLLOWED BY INCREASINGLY HOT/HUMID CONDITIONS TUESDAY WITH
CHANCES FOR SHOWERS AND THUNDERSTORMS TUESDAY INTO WEDNESDAY.
CONTINUED GOOD MODEL AGREEMENT BETWEEN THE 00Z ECMWF AND 00Z GFS.
THE NORTH COUNTRY WILL CONTINUE UNDER A PREVAILING DRY NWLY MID-
LEVEL FLOW REGIME SATURDAY NIGHT AND SUNDAY WITH RELATIVELY LOW
DEWPOINTS (UPR 40S TO LOWER 50S) AND LOW PW VALUES OF 0.6-0.8".
SHOULD CONTINUE MOSTLY CLEAR TO CLOSE OUT THE WEEKEND. LOWS
SATURDAY NIGHT WILL BE IN THE MID 40S TO LOWER 50S...AND WITH WEAK
NEAR- SURFACE FLOW COULD CERTAINLY SEE SOME PATCHY VALLEY FOG
DURING THE PRE-DAWN HOURS. ON SUNDAY...850MB TEMPS CLIMB A BIT TO
+10C TO +11C...SO SHOULD SEE HIGHS IN THE MID 70S IN MOST
LOCATIONS. OVERALL LOOKS LIKE A PLEASANT END TO THE WEEKEND.
SOME SUBTLE CHANGES THEREAFTER WITH 700-500MB SHORTWAVE RIDGE AND
DEVELOPING SW LOW-LEVEL WINDS ON MONDAY. 850MB TEMPS CLIMB TO +14C
AND SHOULD BRING HIGHS TO AROUND 80F IN THE VALLEYS. WILL SEE A
MODEST INCREASE IN DEWPOINTS INTO THE MID-UPR 50S AS WELL. STILL
LOOKS DRY THOUGH MAY SEE PARTLY SUNNY AFTERNOON SKIES WITH CUMULUS
CLOUD FORMATION. STRONGER DEEP LAYER WSW-SW FLOW DEVELOPS TUESDAY
AND WEDNESDAY WHICH WILL LEAD TO HIGHS IN THE LOW 80S TUESDAY WITH
HUMID CONDITIONS. BETTER CHANCE FOR DAYTIME SHOWERS AND
THUNDERSTORMS WITH SURFACE-BASED INSTABILITY TUESDAY...FOLLOWED BY
POSSIBLE SFC LOW AND FRONTAL BOUNDARY APPROACHING FROM THE WEST
TUESDAY NIGHT AND WEDNESDAY WITH SHORTWAVE TROUGH MOVING EASTWARD
FROM THE GREAT LAKES REGION. COULD SEE SHOWERS AND TSTMS ASSOCIATED
WITH THE FRONT. CARRIED 30-35 POPS FOR TUESDAY AND WEDNESDAY.
DEPENDING ON FRONTAL TIMING...COULD BE A FEW DEGREES COOLER
WEDNESDAY (MID-UPR 70S)...ESPECIALLY IF BOUNDARY PUSHES THROUGH
TUESDAY NIGHT.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
THROUGH 12Z FRIDAY...VFR CONDITIONS GENERALLY EXPECTED THROUGH
THIS EVENING WITH SCT050-060 DURING THE DAYLIGHT HRS...THEN SKC
TONIGHT. PATCHY IFR FOG EXPECTED AT MPV/SLK 07-11Z. WINDS
GENERALLY N-NW AROUND 5 KTS EARLY THIS MORNING...THEN 10-12KTS
SUSTAINED WITH GUSTS 15-18KTS DURING THE 15-23Z PERIOD. BECOMING
LIGHT AND VARIABLE BY LATE THIS EVENING.
OUTLOOK 12Z FRIDAY THROUGH MONDAY...
12Z FRIDAY THRU 00Z TUESDAY...VFR AND GENERALLY LIGHT WINDS UNDER
HIGH PRESSURE. NOCTURNAL MVFR TO IFR POSSIBLE ESPECIALLY KSLK/KMPV
IN RADIATION FOG 06-12Z EACH MORNING. PRECIPITATION IS NOT EXPECTED.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...SISSON
NEAR TERM...SISSON
SHORT TERM...SISSON
LONG TERM...BANACOS
AVIATION...BANACOS
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
705 AM EDT THU JUN 19 2014
.SYNOPSIS...
A RIDGE OF HIGH PRESSURE WILL BUILD SOUTHEAST FROM CANADA PUTTING
OUR REGION IN A NORTHERLY FLOW OF FAIR AND DRY WEATHER THROUGH
THIS WEEKEND. TEMPERATURES WILL BE A FEW DEGREES COOLER THAN
AVERAGE THROUGH SATURDAY MORNING THEN A WARMING TREND INTO NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 705 AM EDT THURSDAY...SKIES WILL BE PARTLY TO MOSTLY SUNNY
TODAY FROM A STEADY NORTH NORTHEST FLOW OF SUBSIDING DRY AIR AND
COOLER TEMPS FROM TRAJECTORIES COMING RIGHT FROM JAMES BAY. 850
TEMPS WILL BE FALL SLIGHTLY FROM AROUND 10C DOWN TO ABOUT 7C IN
THE NORTH THIS AFTERNOON. THE RAP SHOWS THIS GRADIENT POISED JUST
NORTH THE BORDER EARLY THIS MORNING. THIS SHOULD YIELD HIGH TEMPS
IN THE 70S MOST PLACES, MILDEST IN THE MID TO UPPER 70S SOUTHERN
AND LOWER VALLEY LOCATIONS. THERE WILL BE SOME THIN FAIR WEATHER
CUMULUS CLOUDS TODAY ESPECIALLY NORTHERN MTNS WITH COLD ADVECTION,
EVAPOTRANSPIRATION, AND VORT MAX SWINGING THROUGH EARLY AFTERNOON.
WINDS WILL BE FROM THE NORTH NORTHWEST 10 TO 20 MPH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
AS OF 441 AM EDT THURSDAY...NORTHERLY FLOW CONTINUES THROUGH
SATURDAY WITH MAINLY SCATTERED DIURNAL DRIVEN CUMULUS CLOUDS AND
MOSTLY CLEAR NIGHTS. 850 TEMPS 5-8C FRIDAY AND WARMING TO 9-10C
SATURDAY SO HIGH TEMPS UPPER 60S TO LOWER 70S FRIDAY AND IN THE
70S ON SATURDAY. LOW TEMPS MOSTLY IN THE 40S, EXCEPT A FEW UPPER
30S IN THE NORMALLY COLD SHELTERED SPOTS. DAYTIME WINDS WILL BE
FROM THE NORTH NORTHWEST 10 TO 20 MPH AND LIGHT AT NIGHT.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 340 AM EDT THURSDAY...QUIET STRETCH OF DRY/SEASONABLE
WEATHER CONDITIONS IS EXPECTED TO EXTEND THROUGH MONDAY
NIGHT...FOLLOWED BY INCREASINGLY HOT/HUMID CONDITIONS TUESDAY WITH
CHANCES FOR SHOWERS AND THUNDERSTORMS TUESDAY INTO WEDNESDAY.
CONTINUED GOOD MODEL AGREEMENT BETWEEN THE 00Z ECMWF AND 00Z GFS.
THE NORTH COUNTRY WILL CONTINUE UNDER A PREVAILING DRY NWLY MID-
LEVEL FLOW REGIME SATURDAY NIGHT AND SUNDAY WITH RELATIVELY LOW
DEWPOINTS (UPR 40S TO LOWER 50S) AND LOW PW VALUES OF 0.6-0.8".
SHOULD CONTINUE MOSTLY CLEAR TO CLOSE OUT THE WEEKEND. LOWS
SATURDAY NIGHT WILL BE IN THE MID 40S TO LOWER 50S...AND WITH WEAK
NEAR- SURFACE FLOW COULD CERTAINLY SEE SOME PATCHY VALLEY FOG
DURING THE PRE-DAWN HOURS. ON SUNDAY...850MB TEMPS CLIMB A BIT TO
+10C TO +11C...SO SHOULD SEE HIGHS IN THE MID 70S IN MOST
LOCATIONS. OVERALL LOOKS LIKE A PLEASANT END TO THE WEEKEND.
SOME SUBTLE CHANGES THEREAFTER WITH 700-500MB SHORTWAVE RIDGE AND
DEVELOPING SW LOW-LEVEL WINDS ON MONDAY. 850MB TEMPS CLIMB TO +14C
AND SHOULD BRING HIGHS TO AROUND 80F IN THE VALLEYS. WILL SEE A
MODEST INCREASE IN DEWPOINTS INTO THE MID-UPR 50S AS WELL. STILL
LOOKS DRY THOUGH MAY SEE PARTLY SUNNY AFTERNOON SKIES WITH CUMULUS
CLOUD FORMATION. STRONGER DEEP LAYER WSW-SW FLOW DEVELOPS TUESDAY
AND WEDNESDAY WHICH WILL LEAD TO HIGHS IN THE LOW 80S TUESDAY WITH
HUMID CONDITIONS. BETTER CHANCE FOR DAYTIME SHOWERS AND
THUNDERSTORMS WITH SURFACE-BASED INSTABILITY TUESDAY...FOLLOWED BY
POSSIBLE SFC LOW AND FRONTAL BOUNDARY APPROACHING FROM THE WEST
TUESDAY NIGHT AND WEDNESDAY WITH SHORTWAVE TROUGH MOVING EASTWARD
FROM THE GREAT LAKES REGION. COULD SEE SHOWERS AND TSTMS ASSOCIATED
WITH THE FRONT. CARRIED 30-35 POPS FOR TUESDAY AND WEDNESDAY.
DEPENDING ON FRONTAL TIMING...COULD BE A FEW DEGREES COOLER
WEDNESDAY (MID-UPR 70S)...ESPECIALLY IF BOUNDARY PUSHES THROUGH
TUESDAY NIGHT.
&&
.AVIATION /11Z THURSDAY THROUGH MONDAY/...
THROUGH 12Z FRIDAY...LINGERING MID-LEVEL CLOUDS WITHIN FRONTAL
INVERSION ARE RESULTING IN GENERALLY VFR CEILINGS ACROSS THE
REGION AT 05Z. DURING THE PRE-DAWN HOURS...DRIER AIR WILL
GRADUALLY WORK INTO THE REGION FROM THE NORTH...AND SLOWLY
DISSIPATE THESE CLOUDS. SLOWER CLEARING SHOULD LIMIT FOG
POTENTIAL...AND THE TAFS NOW INDICATE JUST TEMPO GROUPS FOR
POSSIBLE IFR FOG AT MPV/SLK 08-11Z...AND PERIODS VCFG OR BRIEF
MVFR FOG AT PBG/BTV TOWARD DAYBREAK. ANY FOG WILL DISSIPATE AFTER
SUNRISE WITH MOSTLY CLEAR CONDITIONS. DAYLIGHT HRS SKC-
FEW040-050...WITH A FEW FAIR WEATHER CU DOTTING THE HIGHER TERRAIN
AREAS. WINDS GENERALLY N-NW AROUND 5 KTS EARLY TODAY...THEN
10G18KT DURING THE 15-23Z THURSDAY PERIOD. BECOMING LIGHT AND
VARIABLE AGAIN FOR TONIGHT.
OUTLOOK 12Z FRIDAY THROUGH MONDAY...
12Z FRIDAY THRU 00Z TUESDAY...VFR AND GENERALLY LIGHT WINDS UNDER
HIGH PRESSURE. NOCTURNAL MVFR TO IFR POSSIBLE ESPECIALLY KSLK/KMPV
IN RADIATION FOG 06-12Z EACH MORNING. PRECIPITATION IS NOT EXPECTED.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...SISSON
NEAR TERM...SISSON
SHORT TERM...SISSON
LONG TERM...BANACOS
AVIATION...BANACOS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1155 PM CDT WED JUN 18 2014
.UPDATE...
ISSUED AT 1150 PM CDT WED JUN 18 2014
LINE OF STORMS MOVING NORTH-NORTHEAST AND PICKING UP STEAM. BUT
INTENSITY HAS OVERALL DECREASED AND WITH INCREASED CIN LAYER AT
THE SURFACE...SPC THINKS THREAT FOR DAMAGING WIND IS LESS. STILL
SOMETHING TO WATCH.
UPDATE ISSUED AT 707 PM CDT WED JUN 18 2014
LINE OF SHOWERS AND THUNDERSTORMS FROM SOUTHEASTERN SASK THROUGH
SOUTH CENTRAL NORTH DAKOTA INTO CENTRAL SOUTH DAKOTA. SURFACE LOW
AT 00Z FROM OBS LOOKS TO BE JUST NORTHEAST OF PIERRE SD. RAP/HRRR
HAS THIS SFC LOW DRIFTING NORTHEAST TOWARD ABERDEEN AREA BY 10Z.
STRONG 850 MB MOISTURE INFLOW AND AXIS OF INSTABILITY AND 1500
J/KG ELEVATED CAPE ALL ADVECT INTO SOUTHEAST ND 04Z-09Z PERIOD
AND RAP MODEL SHOWS 50 KT 850 MB INFLOW AS WELL. FOR THE NEXT FEW
HOURS MAIN ACTION WILL BE SHIFTING SOUTH-SOUTHEAST AS EXTREME SFC
INSTABILITY POCKET REMAINS IN FAR SOUTHEASTERN SD/NW IOWA. THIS
AREA AROUND SIOUX FALLS AND ENVIRONS SUPPORTIVE OF SUPERCELLS
WHICH WILL MERGE INTO A MCS TONIGHT. AREA OF GENERAL RAIN/STORMS
NORTH OF THIS INTO ERN ND. QUESTION IS SEVERE. ELEVATED CAPE
VALUES AND INFLOW SUGGEST SOME SEVERE STORMS PSBL IN THE 04-09Z
PERIOD IN SOUTHEASTERN ND BUT COVERAGE OF SEVERE IS QUESTIONABLE
ATTM. MOISTURE NOT A PROBLEM AS SLOW MOVEMENT NORTHWARD OF
INDIVIDUAL CELLS WILL GIVE HEAVY RAINFALL BUT AS USUAL WHERE AND
HOW MUCH WILL FALL IN QUESTION AND FOR TIME THE TIME BEING WRN
FCST AREA HAS SEEN LEAST AMOUNT OF RAIN THIS MONTH. SO NOT FLOOD
HEADLINES ATTM.
UPON COORD WITH MPX/DLH DID BACK OFF ON NORTHEASTWARD EXTENT OF
STORMS TONIGHT WITH SLOWER ARRIVAL TIMING. HRRR/RAP HAVE STORMS
REACHING NR PKD-GFK AREA 10Z OR SO AND FAR NORTHEASTERN AREAS 12Z
OR SO.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 320 PM CDT WED JUN 18 2014
CHALLENGES INCLUDE HEAVY RAIN/FLOOD POTENTIAL AND SEVERE STORMS
TONIGHT THROUGH THURSDAY. RAP/HRRR HAVE COME INTO GOOD AGREEMENT
WITH EVOLUTION OF TONIGHT/S SET-UP...SO WILL FOLLOW HIGH
RESOLUTION GUIDANCE THROUGH 18 HOURS. THEREAFTER...WILL USE A
GLOBAL MODEL ENSEMBLE.
CONVECTION HAS FIRED ACROSS NORTH-CENTRAL/NORTHWEST SD LATE THIS
AFTERNOON WHERE CAP HAS ERODED ALONG SFC TROUGH AXIS EXTENDING
FROM LOW PRESSURE CENTER NEAR THE EASTERN NE/SD BORDER. FARTHER
EAST...CAP IS VERY STRONG AS EVIDENT ON 18 UTC ABR SOUNDING AND
WILL NEED TO WAIT FOR LOW-LEVEL JET SUPPORT FOR CONVECTION TO
INITIATE AND TAP INTO ELEVATED CAPE UPWARD OF 1500 J/KG. UPDATES
MADE AT 1 PM STILL VALID...SO EXPECT DRY CONDITIONS THROUGH 00 UTC
WITH AN INCREASING THREAT FOR SHOWERS AND THUNDERSTORMS THIS
EVENING AND OVERNIGHT FROM SOUTHWEST TO NORTHEAST. BEST SEVERE
POTENTIAL REMAINS ACROSS SOUTHEAST ND ALONG THE NOSE OF THE 850
HPA JET (HAIL/WIND/TORNADOES) WITH HEAVY RAIN POSSIBLE REGION-WIDE.
MUCH OF EASTERN ND HAS BEEN RELATIVELY DRY...SO NO NEED FOR FLOOD
WATCH...BUT SLOW-MOVING EFFICIENT RAIN PRODUCERS MAY REQUIRE
ADVISORIES.
SFC LOW AND ASSOCIATED WARM/OCCLUDED FRONT MOVE ACROSS THE CENTRAL
FORECAST AREA ON THURSDAY. SEVERE THREAT WILL DEPEND ON EVOLUTION OF
TONIGHT/S STORMS...BUT ANY BREAK IN THE CLOUDS AND RESULTANT HEATING
COULD HELP INITIATE ANOTHER ROUND OF SEVERE THUNDERSTORMS GIVEN A
MOIST UNSTABLE ENVIRONMENT AND A 50 KT 500 HPA JET STREAK ROUNDING
THE BASE OF THE UPPER-LEVEL TROUGH. EVEN WITHOUT SEVERE CONVECTION...
STILL EXPECT WIDESPREAD SHOWERS AND THUNDERSTORMS AS THE BROADER
SFC TROUGH MOVES SLOWLY ACROSS THE FORECAST AREA. PWATS INCREASE
TO 1.75 INCHES...SO WILL NEED TO CAREFULLY MONITOR RAINFALL
AMOUNTS AND POTENTIAL FLOODING ESPECIALLY AS PRECIP MOVES INTO
NORTHWEST AND WEST CENTRAL MN WHICH HAS BEEN HIT HARD BY RECENT
HEAVY RAIN. SHOWERS AND THUNDERSTORMS SHOULD SLOWLY LIFT NORTH AND
EAST THURSDAY NIGHT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 320 PM CDT WED JUN 18 2014
THERE COULD BE SOME WRAP AROUND SHOWERS AND THUNDERSTORMS FRIDAY
INTO SATURDAY AS THE WEAKENING SFC LOW WOBBLES ACROSS THE SOUTHERN
CANADIAN PRAIRIES...BUT MOST AREAS SHOULD STAY DRY. TEMPERATURES
BOTH DAYS SHOULD RISE INTO THE MID 70S TO LOWER 80S WITH LIGHT
SOUTHERLY WIND ON FRIDAY SHIFTING TO THE WEST ON SATURDAY.
FOR SAT NIGHT THROUGH WEDNESDAY...EXPECT OVERALL DRIER WEATHER WITH
TEMPS NEAR TO SLIGHTLY ABOVE NORMAL. WE SHOULD REMAIN IN OVERALL
ZONAL FLOW WITH SOME RIDGING ALOFT. CAN/T RULE OUT SOME SHOWERS/
STORMS REALLY ANY DAY DURING THE AFTERNOON/EVENING...BUT OVERALL
NOT EXPECTING THAT MUCH COVERAGE OF CONVECTION. WE WILL MAINTAIN
SOME LOWER POPS THROUGH THE PERIOD THOUGH...TYPICAL OF A SUMMER
LIKE PATTERN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1150 PM CDT WED JUN 18 2014
TRICKY FCST WITH RAIN TIMING AND ANY MVFR CIGS AS RAIN MOVES IN
OVERNIGHT-THURSDAY MORNING. EXPECT A WIND GUST IN FARGO SHORTLY.
IDEA THURSDAY IS FOR WINDS TO TURN SOUTH-SOUTHWEST GFK-FAR-DVL
REGION MIDDAY-AFTERNOON AND CIGS TO IMPROVE.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...RIDDLE
SHORT TERM...ROGERS
LONG TERM...ROGERS/DK
AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
640 AM EDT THU JUN 19 2014
.SYNOPSIS...
WETTER WITH ROUNDS OF STORMS/SHOWERS INTO WEEKEND...WITH FRONT IN
UPPER OHIO VALLEY. DOWNPOURS POSSIBLE.
&&
.NEAR TERM /THROUGH TONIGHT/...
HAVE TWO AREAS OF CONVECTION TO WATCH INTO THIS MORNING. LARGE
MASS OF RELATIVELY STRONG CONVECTION CURRENTLY JUST OF TO
NW...ASSOCIATED WITH 500MB VORT MAX THAT THE RAP SHOWS WEAKENING
AS IT ENTERS CWA OVER THE NEXT SEVERAL HOURS. THIS CONVECTION ALSO
HAS PUT OUT AN OUTFLOW BOUNDARY CURRENTLY STRETCHING FROM CMH TO
CVG...WHICH COULD DEVELOP ADDITIONAL SHOWERS AND THUNDERSTORMS AS
IT MOVES EAST TOWARD AND INTO CWA. SECOND AREA OF ISOLATED TO
SCATTERED CONVECTION STRETCHING FROM SW OF CRW TO AROUND EKN. THIS
IS ALONG AN OLD OUTFLOW BOUNDARY THAT IS SLOWLY DRIFTING SE. ALL
IN ALL...HAVE A TRICKY FORECAST WHEN IT COMES TO TIMING OF
CONVECTION TODAY...AS MODELS HAVE NOT BEEN HANDLING IT VERY WELL
UP TO THIS POINT. IN GENERAL...JUST USED EXTRAPOLATION OF CURRENT
RADAR TRENDS TO DRAW POPS THROUGH THE MORNING. BY THIS
AFTERNOON...HAVE SURFACE BOUNDARY SINKING SOUTH...INTO NORTHERN
CWA...WITH TAIL OF THIS MORNINGS VORT MAX STILL PULLING OUT. SO
HAVE LIKELY POPS ALONG AND SOUTH OF BOUNDARY...GRADUALLY SINKING
SOUTH INTO TONIGHT. WITH VERY HUMID AIRMASS IN PLACE...ANY
SHOWER/STORM WILL BE CAPABLE OF DOWNPOURS. WILL LEAVE FLASH FLOOD
WATCH AS IS...ALTHOUGH THINK STREAMS SHOULD BE ABLE TO HANDLE RAIN
TODAY INTO TONIGHT...AND IT MIGHT JUST BE PRIMING THE GROUND FOR
RAIN LATER THIS WEEK. GRANTED...ANY DOWNPOUR COULD CAUSE WATER TO
POND IN TYPICAL AREAS WITH POOR DRAINAGE. COOLED TEMPS ACROSS THE
NORTH BOTH TODAY AND TONIGHT WITH BOUNDARY IN THE AREA.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
MODELS INDICATE A STATIONARY BOUNDARY SHOULD BE LOCATED ACROSS OUR
CENTRAL/NORTHERN ZONES ON FRIDAY...WITH THE FRONT EXPECTED TO MOVE
LITTLE INTO SATURDAY. IN ADDITION...A MID-LEVEL TROF WILL APPROACH
FROM THE NORTHWEST FRIDAY...BEFORE PUSHING SOUTHEAST FRIDAY
NIGHT.
A SURFACE LOW IS THEN EXPECTED TO PUSH EAST. THE NAM INDICATES THIS
FEATURE WILL PUSH EAST FRIDAY NIGHT INTO SATURDAY...WHILE THE GFS
CLOSER TO SATURDAY AFTERNOON.
PWAT VALUES OF 1.5 TO 2 INCHES ARE ANTICIPATED FRIDAY THROUGH MUCH
OF FRIDAY NIGHT. END RESULT OF ALL OF THIS SHOULD BE CHANCES FOR
SHOWERS AND STORMS FRIDAY INTO SATURDAY. THE HIGHEST COVERAGE OF
STORMS WILL BE FRIDAY AND FRIDAY NIGHT. HAVE CONTINUED MENTION OF
HEAVY RAIN DURING THESE TWO PERIODS.
THE BEST MOISTURE SHOULD PUSH SOUTHEAST OF REGION BY EARLY
SATURDAY...WITH DRIER AIR IN PLACE FOR SUNDAY. NORTHWEST MID-LEVEL
FLOW WITH EMBEDDED SHORTWAVES WILL KEEP SHOWER AND STORM CHANCES IN
THE FORECAST INTO SUNDAY. HOWEVER...THE DRIER AIRMASS SHOULD LOWER
THE THREAT OF HEAVY RAINS...AND WILL NOT INCLUDE MENTION OF HEAVY
RAIN IN FORECAST.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
A CONTINUED GENERALLY MESSY AND UNSETTLED PATTERN WILL CONTINUE FOR
THE EXTENDED PERIOD....CHARACTERIZED BY WARM AND MUGGY CONDITIONS
WITH PERIODIC CHANCES FOR SHOWERS AND THUNDERSTORMS THROUGHOUT. W/NW
FLOW WITH A DIFFUSE SFC FRONT REMAINS DRAPED NEAR THE AREA FOR MUCH
OF THE PERIOD. PERHAPS A BETTER CHANCE FOR SHOWERS/THUNDERSTORMS
ARRIVES BY MID-WEEK NEXT WEEK AS A SHARP UPPER LEVEL TROUGH
APPROACHES AND MOVES ACROSS THE SOUTHERN GREAT LAKES WITH AN
ATTENDANT COLD FRONT. TOUGH TO PIN DOWN EXACT TIMING OF COURSE THIS
FAR IN ADVANCE WITH DIFFERENCES IN THE TIMING BETWEEN OP EXTENDED
NWP...WITH VARYING ENSEMBLES NOT REALLY AIDING MUCH.
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
COMPLICATED AVIATION FORECAST WITH MULTIPLE ROUNDS OF THUNDERSTORMS
EXPECTED TODAY AS A SURFACE BOUNDARY SINKS IN FROM THE SOUTH...AND
SEVERAL UPPER LEVEL DISTURBANCES PASS BY. IN THE VERY MOIST
ATMOSPHERE THUNDERSTORMS COULD FORM PRETTY MUCH ANYWHERE AT
ANYTIME. DID TAKE A SHOT AND INCLUDED SOME TEMPOS FOR IFR IN
THUNDERSTORMS BASED MOSTLY OF THE HRRR...BUT CONFIDENCE IS RATHER
LOW.
FOG POTENTIAL TONIGHT DEPENDS ON IF SOME BREAKS CAN FORM IN THE
CLOUDS...DID INCLUDE SOME MVFR FOG...IFR AT EKN...BASED ON LAV
PROBABILITIES.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z FRIDAY...
FORECAST CONFIDENCE: LOW.
ALTERNATE SCENARIOS: TIMING OF CONVECTION COULD VARY. FOG TONIGHT
MAY VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 11 12 13 14 15 16 17 18 19 20 21 22
EDT 1HRLY 07 08 09 10 11 12 13 14 15 16 17 18
CRW CONSISTENCY H H H M M M M M M M M M
HTS CONSISTENCY H H H M M M M M M M M M
BKW CONSISTENCY H H H H H H H H H H H M
EKN CONSISTENCY H M M M M M H H H H H H
PKB CONSISTENCY H H H M H H H M M M M M
CKB CONSISTENCY H M M M H H H H H H H M
AFTER 12Z FRIDAY...
ROUNDS OF SHOWERS/THUNDERSTORMS THROUGH SATURDAY WITH IFR CONDITIONS
POSSIBLE.
&&
.HYDROLOGY...
STILL EXPECTING SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS INTO
THIS WEEKEND AND WILL LEAVE FLASH FLOOD WATCH AS IS. ABUNDANT
MOISTURE IN THE ATMOSPHERE COULD LEAD TO DOWNPOURS OUT OF ANY
SHOWER OR STORM. THINK RAIN TODAY INTO TONIGHT WILL MOSTLY JUST
PRIME THE GROUND FOR FRIDAY INTO SATURDAY...BUT CANNOT RULE OUT LOCALIZED
ISSUES TODAY AS WELL.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FLASH FLOOD WATCH THROUGH LATE FRIDAY NIGHT FOR WVZ005>011-
013>020-026>032-036>040-046-047.
OH...FLASH FLOOD WATCH THROUGH LATE FRIDAY NIGHT FOR OHZ066-067-075-
076-083>087.
KY...FLASH FLOOD WATCH THROUGH LATE FRIDAY NIGHT FOR KYZ101>103-105.
VA...NONE.
&&
$$
SYNOPSIS...JSH/MZ
NEAR TERM...MZ
SHORT TERM...JSH
LONG TERM...50
AVIATION...MZ
HYDROLOGY...MZ
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
324 AM EDT THU JUN 19 2014
.SYNOPSIS...
WETTER WITH ROUNDS OF STORMS/SHOWERS INTO WEEKEND...WITH FRONT IN
UPPER OHIO VALLEY. DOWNPOURS POSSIBLE.
&&
.NEAR TERM /THROUGH TONIGHT/...
HAVE TWO AREAS OF CONVECTION TO WATCH INTO THIS MORNING. LARGE
MASS OF RELATIVELY STRONG CONVECTION CURRENTLY JUST OF TO
NW...ASSOCIATED WITH 500MB VORT MAX THAT THE RAP SHOWS WEAKENING
AS IT ENTERS CWA OVER THE NEXT SEVERAL HOURS. THIS CONVECTION ALSO
HAS PUT OUT AN OUTFLOW BOUNDARY CURRENTLY STRETCHING FROM CMH TO
CVG...WHICH COULD DEVELOP ADDITIONAL SHOWERS AND THUNDERSTORMS AS
IT MOVES EAST TOWARD AND INTO CWA. SECOND AREA OF ISOLATED TO
SCATTERED CONVECTION STRETCHING FROM SW OF CRW TO AROUND EKN. THIS
IS ALONG AN OLD OUTFLOW BOUNDARY THAT IS SLOWLY DRIFTING SE. ALL
IN ALL...HAVE A TRICKY FORECAST WHEN IT COMES TO TIMING OF
CONVECTION TODAY...AS MODELS HAVE NOT BEEN HANDLING IT VERY WELL
UP TO THIS POINT. IN GENERAL...JUST USED EXTRAPOLATION OF CURRENT
RADAR TRENDS TO DRAW POPS THROUGH THE MORNING. BY THIS
AFTERNOON...HAVE SURFACE BOUNDARY SINKING SOUTH...INTO NORTHERN
CWA...WITH TAIL OF THIS MORNINGS VORT MAX STILL PULLING OUT. SO
HAVE LIKELY POPS ALONG AND SOUTH OF BOUNDARY...GRADUALLY SINKING
SOUTH INTO TONIGHT. WITH VERY HUMID AIRMASS IN PLACE...ANY
SHOWER/STORM WILL BE CAPABLE OF DOWNPOURS. WILL LEAVE FLASH FLOOD
WATCH AS IS...ALTHOUGH THINK STREAMS SHOULD BE ABLE TO HANDLE RAIN
TODAY INTO TONIGHT...AND IT MIGHT JUST BE PRIMING THE GROUND FOR
RAIN LATER THIS WEEK. GRANTED...ANY DOWNPOUR COULD CAUSE WATER TO
POND IN TYPICAL AREAS WITH POOR DRAINAGE. COOLED TEMPS ACROSS THE
NORTH BOTH TODAY AND TONIGHT WITH BOUNDARY IN THE AREA.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
MODELS INDICATE A STATIONARY BOUNDARY SHOULD BE LOCATED ACROSS OUR
CENTRAL/NORTHERN ZONES ON FRIDAY...WITH THE FRONT EXPECTED TO MOVE
LITTLE INTO SATURDAY. IN ADDITION...A MID-LEVEL TROF WILL APPROACH
FROM THE NORTHWEST FRIDAY...BEFORE PUSHING SOUTHEAST FRIDAY
NIGHT.
A SURFACE LOW IS THEN EXPECTED TO PUSH EAST. THE NAM INDICATES THIS
FEATURE WILL PUSH EAST FRIDAY NIGHT INTO SATURDAY...WHILE THE GFS
CLOSER TO SATURDAY AFTERNOON.
PWAT VALUES OF 1.5 TO 2 INCHES ARE ANTICIPATED FRIDAY THROUGH MUCH
OF FRIDAY NIGHT. END RESULT OF ALL OF THIS SHOULD BE CHANCES FOR
SHOWERS AND STORMS FRIDAY INTO SATURDAY. THE HIGHEST COVERAGE OF
STORMS WILL BE FRIDAY AND FRIDAY NIGHT. HAVE CONTINUED MENTION OF
HEAVY RAIN DURING THESE TWO PERIODS.
THE BEST MOISTURE SHOULD PUSH SOUTHEAST OF REGION BY EARLY
SATURDAY...WITH DRIER AIR IN PLACE FOR SUNDAY. NORTHWEST MID-LEVEL
FLOW WITH EMBEDDED SHORTWAVES WILL KEEP SHOWER AND STORM CHANCES IN
THE FORECAST INTO SUNDAY. HOWEVER...THE DRIER AIRMASS SHOULD LOWER
THE THREAT OF HEAVY RAINS...AND WILL NOT INCLUDE MENTION OF HEAVY
RAIN IN FORECAST.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
A CONTINUED GENERALLY MESSY AND UNSETTLED PATTERN WILL CONTINUE FOR
THE EXTENDED PERIOD....CHARACTERIZED BY WARM AND MUGGY CONDITIONS
WITH PERIODIC CHANCES FOR SHOWERS AND THUNDERSTORMS THROUGHOUT. W/NW
FLOW WITH A DIFFUSE SFC FRONT REMAINS DRAPED NEAR THE AREA FOR MUCH
OF THE PERIOD. PERHAPS A BETTER CHANCE FOR SHOWERS/THUNDERSTORMS
ARRIVES BY MID-WEEK NEXT WEEK AS A SHARP UPPER LEVEL TROUGH
APPROACHES AND MOVES ACROSS THE SOUTHERN GREAT LAKES WITH AN
ATTENDANT COLD FRONT. TOUGH TO PIN DOWN EXACT TIMING OF COURSE THIS
FAR IN ADVANCE WITH DIFFERENCES IN THE TIMING BETWEEN OP EXTENDED
NWP...WITH VARYING ENSEMBLES NOT REALLY AIDING MUCH.
&&
.AVIATION /07Z THURSDAY THROUGH MONDAY/...
COMPLICATED AVIATION FORECAST WITH MULTIPLE ROUNDS OF THUNDERSTORMS
EXPECTED TODAY. FAIRLY LOW CONFIDENCE ON EXACTLY WHERE/WHEN LOWER
CATEGORY CONDITIONS WILL BE. IN THE VERY MOIST ATMOSPHERE
THUNDERSTORMS COULD FORM PRETTY MUCH ANYWHERE ANYTIME...SO
ANTICIPATE NEEDING AMENDMENTS AS THE TRENDS BECOME MORE CLEAR.
INCLUDED A BIT OF MVFR FOG BETWEEN ROUNDS OF CONVECTION AT PKB AND
CKB...WHERE HAS FALLEN OVER THE LAST SEVERAL HOURS...BUT CLOUDS AND
A LIGHT WIND COULD KEEP THAT FROM OCCURRING.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z FRIDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING OF CONVECTION COULD VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE THU 06/19/14
UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
EDT 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13
CRW CONSISTENCY H H H H H H H H M M M M
HTS CONSISTENCY H H H H H H H H M M M M
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY M H H H H H H H H H H H
PKB CONSISTENCY H H H H M M M M M H H H
CKB CONSISTENCY H H H H H H M M M H H H
AFTER 06Z FRIDAY...
ROUNDS OF SHOWERS/THUNDERSTORMS THROUGH SATURDAY WITH IFR CONDITIONS
POSSIBLE.
&&
.HYDROLOGY...
STILL EXPECTING SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS INTO
THIS WEEKEND AND WILL LEAVE FLASH FLOOD WATCH AS IS. ABUNDANT
MOISTURE IN THE ATMOSPHERE COULD LEAD TO DOWNPOURS OUT OF ANY
SHOWER OR STORM. THINK RAIN TODAY INTO TONIGHT WILL MOSTLY JUST
PRIME THE GROUND FOR FRIDAY INTO SATURDAY...BUT CANNOT RULE OUT LOCALIZED
ISSUES TODAY AS WELL.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FLASH FLOOD WATCH THROUGH LATE FRIDAY NIGHT FOR WVZ005>011-
013>020-026>032-036>040-046-047.
OH...FLASH FLOOD WATCH THROUGH LATE FRIDAY NIGHT FOR OHZ066-067-075-
076-083>087.
KY...FLASH FLOOD WATCH THROUGH LATE FRIDAY NIGHT FOR KYZ101>103-105.
VA...NONE.
&&
$$
SYNOPSIS...JSH/MZ
NEAR TERM...MZ
SHORT TERM...JSH
LONG TERM...50
AVIATION...MZ
HYDROLOGY...MZ
AREA FORECAST DISCUSSION
NWS TULSA OK
633 AM CDT THU JUN 19 2014
.DISCUSSION...
THE 12Z TAF DISCUSSION IS INCLUDED BELOW.
&&
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
MVFR STRATUS WILL AFFECT MOST OF THE TERMINALS AGAIN THIS
MORNING...AT LEAST FROM TIME TO TIME...IN THIS LOW LVL MOISTURE
RETURN REGIME AT NIGHT. COMPLEX OF STORMS OVER CENTRAL OK WILL
SLIDE EAST INTO NORTHEAST OK BEFORE WEAKENING TOWARD MIDDAY OR
EARLY AFTERNOON PER LATEST HRRR GUIDANCE. WILL INSERT TEMPO GROUPS
IN THE NE OK TAFS BTWN 15 AND 19Z TO COVER. THERE IS SOME
POTENTIAL FOR ISOLD TSRA THIS AFTERNOON...SO A PROB30 SHUD SUFFICE
FOR THE ERN OK SITES. THINK NW AR WILL STAY DRY THRU MOST OF THE
PERIOD. SOME REDEVELOPMENT IS EXPECTED OVERNIGHT...ESPECIALLY
AFTER 06Z ACROSS NE OK INTO NW AR.
LACY
&&
.PREV DISCUSSION... /ISSUED 436 AM CDT THU JUN 19 2014/
DISCUSSION...
CONVECTIVE CLUSTER CURRENTLY OVER WESTERN OKLAHOMA
WILL CONTINUE MOVING EAST INTO HIGH PWA ENVIRONMENT
OVER EASTERN OKLAHOMA. SHOWERS AND THUNDER COMMON
TODAY FOR EASTERN OK..LITTLE LESS SO NORTHWEST AR.
MODEL LAYER DIV - Q FIELDS SHOW AMPLE LIFT TONIGHT
THROUGH FRIDAY IN MOIST CHANNEL. MAY BE SOME HEAVY
RAINFALL DURING THIS PERIOD.
GENERALLY DRY OVER THE WEEKEND BEFORE UPPER FLOW
PUSHES A COOL FRONTAL BOUNDARY FROM KANSAS OUR WAY
MONDAY. THAT BOUNDARY AND MINOR WAVES IN A ZONAL
FLOW DICTATES CHANCE POPS THROUGH MID WEEK.
GW
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 86 73 90 72 / 70 60 50 20
FSM 88 72 91 70 / 40 40 40 20
MLC 85 72 90 70 / 50 40 50 10
BVO 85 69 89 68 / 70 80 40 20
FYV 82 70 86 67 / 50 60 50 20
BYV 84 70 86 69 / 30 60 40 20
MKO 85 72 90 69 / 50 60 50 20
MIO 83 70 87 70 / 60 70 40 20
F10 84 72 90 69 / 60 50 50 20
HHW 87 72 91 70 / 30 20 40 0
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
AVIATION...30
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1022 PM EDT FRI JUN 20 2014
.SYNOPSIS...
AN UPPER RIDGE WILL CONTINUE TO BREAK DOWN THROUGH THIS EVENING
RESULTING IN WEAKENING HIGH PRESSURE CURRENTLY IN PLACE OVER THE
AREA. THIS SHOULD YIELD A GREATER COVERAGE OF SHOWERS AND
THUNDERSTORMS ACROSS THE AREA OVER THE WEEKEND AND INTO EARLY NEXT
WEEK. A TYPICAL WARM SUMMERLIKE PATTERN WILL CONTINUE THROUGH NEXT
WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
EVENING UPDATE...LATEST REGIONAL COMP REF SHOWS WEAKENING
CONVECTION IN AND AROUND THE CWFA...WHICH AGREES WELL WITH THE
DIFFUSE ENERGY FIELD ALOFT. THERE COULD BE SOME TSTMS AFFECTING THE
NRN MTNS OVERNIGHT ASSOCIATED WITH AN MCS SRN FLANK
OUTFLOW...HOWEVER NOT EXPECTING ANY MORE THAN A FEW LIGHTNING
STRIKES AND LOCALIZED GUSTY WINDS. SOME MTN VALLEY FG IS
POSSIBLE...BUT NOT TOO CERTAIN WITH THE AMOUNT OF DEBRIS CLOUDS
MOVING IN FROM THE NW. THE GOING POPS ARE IN GOOD SHAPE AND MADE
ONLY MINOR ADJS TO THE MIN TEMP GRID.
730 PM EDT UPDATE...A NICE LOBE OF VORT ENERGY HAS SPAWNED A LINE OF
STRONG TO SEVERE CONVECTION ACROSS THE NC MTNS AND FTHILLS THIS
EVENING. THE STEERING FLOW HAS INCREASED AS WELL AND STRENGTHENED
INFLOW CONVERGENT UPDRAFTS. ANTICIPATE A WEAKENING TREND AS THESE
STORMS MOVE OUT OF THE HIGHER TERRAIN INTO MORE STABLE AIR OVER THE
NEXT COUPLE HRS. HAVE RECEIVED A FEW REPORTS OF FUNNEL CLOUDS WHICH
ARE POSSIBLE WITH THE LVLV ROTATING UPDRAFTS. HOWEVER...A COUPLE
REPORTS HAVE INDICATED TORNADOES ON THE GROUND...WHICH ARE NOT
POSSIBLE IN THE CURRENT LOW SHEAR ENVIRONMENT. THESE REPORTS ARE
LIKELY SCUD CLOUDS AND/OR CLOUDS ASSOCIATED WITH STRONG RAINSHAFTS.
MADE MINOR TWEAKS TO THE T/TDS GRIDS DUE TO PRECIP OVER THE PAST 3
HRS.
430 PM EDT UPDATE...LOW SFC TD/S AND A NOTABLE LOBE OF DNVA HAS KEPT
CONVECTION MINIMAL AND RELATIVELY SHORT LIVED ACROSS CWFA THUS FAR
THIS AFTERNOON. THE STORMS TO THE EAST HAVE BEEN ABLE TO TAP INTO
HIGH VALUES OF DCAPE AND PRODUCE SEVERE WINDS...BUT THE REMAINING
CELLS HAVE HAD FAIRLY NARROW AND WEAKER UPDRAFTS. THE NAM12 HAS A
GOOD HANDLE ON THE UPPER VORT FIELD AND WILL FOLLOW IT/S GUIDANCE
WRT TO POPS AND CONVEC INITIATION OVER THE NEXT COUPLE HRS. THE
UPSTATE HAS THE LOWEST INSTABILITY COMBINED WITH NEGATIVE ULVL
FORCING...SO POPS WILL BE LOWERED TO ISOL THERE...ACROSS THE SRN NC
FTHILLS. THE BEST CHANCE FOR NEW DEVELOPMENT WILL BE ACROSS THE NC
MTN SPINE WHERE ENHANCED CONVECTION SHOULD MOVE IN AND LIKELY WEAKEN
THROUGH 8 PM.
AS OF 200 PM EDT...CELLS NOW LINING UP ALONG THE BLUE RIDGE AS A
WEAK RIPPLE ROUNDS THE RIDGE OVER THE LOWER MISSISSIPPI VALLEY AND
MOVES SEWD ACRS THE AREA. HRRR SEEMS TO HAVE PICKED UP ON THIS
ACTIVITY AND ALLOWS IT TO PROPAGATE SEWD SLIGHTLY BEFORE
DISSIPATING...POSSIBLY DUE TO DOWNSLOPING BY THE NW FLOW ABOVE THE
BOUNDARY LAYER. THE NCEP HIRES WINDOW /NMM/ SUGGESTS THE SAME...BUT
DEVELOPS A NEW ROUND OF CONVECTION IN THE MTNS BEHIND IT WHICH FILLS
IN THE SAME AREA. DEWPOINTS HAVE MIXED OUT SLIGHTLY AS
EXPECTED...BUT NOT ENOUGH TO KEEP SBCAPE FROM RISING TO 2000 J OR
MORE PER SPC MESOANALYSIS. NO SEVERE REPORTS HAVE YET BEEN RECEIVED
BUT A FEW STORMS HAVE MET WARNING CRITERIA. I AM NO LONGER CONFIDENT
IN OUR EARLIER EXPECTATIONS THAT WE WOULD NOT GET UNSTABLE ENOUGH
FOR LARGE HAIL TO BE MUCH OF A CONCERN...BUT PROFILES REMAIN DRY
ENOUGH FOR DCAPES OF 700-1000 J SUPPORTING A MICROBURST THREAT. CHC
RANGE POPS HAVE BEEN MAINTAINED ACRS MOST OF THE AREA...BUT NOW THE
GREATEST CHANCE APPEARS TO BE DOWNSTREAM OF THE CURRENT ACTIVITY.
SOME MODELS INCLUDING THE NAM TRY TO DEVELOP ANOTHER ROUND OF
CONVECTION AFTER SUNSET...BUT PROFILES HAVE ENOUGH CIN THAT I THINK
THIS IS UNLIKELY IN THE PRESENCE OF SUCH WEAK FORCING. POPS DIMINISH
EAST OF THE MTNS BY LATE EVENING.
MAIN FORECAST CHALLENGE FOR THE OVERNIGHT IS WHETHER ANY ACTIVITY
WILL MOVE INTO OUR AREA FROM THE WEST...AS SUGGESTED BY SOME OF THE
MESO GUIDANCE AND THE 12Z NAM. THE NAM SHOWS AN MCV DEVELOPING OVER
THE OHIO VALLEY LATE THIS AFTN AND PROGRESSING SEWD ACRS KY/TN...THE
ORIGINAL CONVECTION DYING BUT THE MCV KICKING OFF NEW DEVELOPMENT ON
THE WEST SLOPES OF THE MTNS WHICH THEN MOVES INTO NW NC AROUND
DAYBREAK. SO FAR THE NAM DEPICTION OF THE ORIGINATING CONVECTION
SEEMS OVERDONE...SO WILL ONLY GIVE THIS SMALL WEIGHT IN THE FCST.
CLOUD COVER PROGGED BY THE MODELS APPEARS MAINLY TO BE CONVECTIVE
DEBRIS AND IT IS A BIT HARDER TO HEDGE ON THAT.
THE NAM SUGGESTS DEEP RH WILL BE HIGHER ON SATURDAY...PROBABLY SINCE
IT EXPECTS DEBRIS TO COME IN DURING THE MORNING. GFS PROFILES REALLY
DO NOT LOOK TOO MUCH DIFFERENT FROM TODAY...THOUGH SBCAPE IS STILL
LOWER DUE TO SLIGHTLY WEAKER LAPSE RATES. THE DIFFERENCE IS NOT ONLY
IMPORTANT FOR THE POTENTIALLY SIGNIFICANT REDUCTION IN INSTABILITY
DUE TO CLOUDIER SKIES...BUT FOR A REDUCTION IN DCAPE AND MITIGATED
SEVERE RISK. SPC FEATURES A 5 PCT AREA JUST TO OUR EAST WHERE WEAK
SHORTWAVE /THE POTENTIAL MCV/ WILL PASS OVER DURING PEAK HEATING. IT
DOES APPEAR THE BEST PRECIP CHANCES OVERALL WILL BE DURING THE
MORNING IN THE NORTHERN FA AND THEN OVER THE I-77 CORRIDOR DURING
THE AFTN WHERE THE BEST BUOYANCY IS SUGGESTED. TEMPS TONIGHT AND
TOMORROW WILL REMAIN A CATEGORY OR SO ABOVE CLIMO.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AS OF 200 PM FRIDAY...HEIGHTS WILL GRADUALLY FALL THROUGH EARLY NEXT
WEEK...AS UPPER HIGH CONTINUES TO WEAKEN AND RETROGRADE TOWARDS
THE WESTERN GULF OF MEXICO. THIS WILL ALSO ALLOW WEAK FRONTAL ZONE
TO BACK DOOR ITS WAY THROUGH THE AREA BY SUNDAY...POSSIBLY
INTRODUCING SLIGHTLY COOLER AND DRIER AIR. THIS IS NOT EXPECTED TO
ELIMINATE INSTABILITY ENOUGH TO HALT DIURNAL CONVECTION...BUT
COVERAGE OF SUNDAY AFTERNOON/EVENING CONVECTION IS EXPECTED TO BE
MORE TYPICAL OF WHAT ONE WOULD EXPECT THIS TIME OF YEAR (30-40 POPS
MTNS...20/30 PIEDMONT).
BY MONDAY... SHORT TERM MODELS DEPICT ESTABLISHMENT OF AN E/SE FLOW
IN ASSOCIATION WITH A WEAK INVERTED RIDGE ALONG THE EASTERN
SEABOARD. THIS UPSLOPE FLOW COULD SUPPORT A BIT MORE IN THE WAY OF
DIURNAL CONVECTION BY MONDAY AFTERNOON...SO POPS RETURN TO ABOVE
CLIMO BY THIS TIME. WEAK SHEAR WITH HALFWAY DECENT STEERING FLOW
SHOULD PRECLUDE ANYTHING MORE THAN A TYPICAL EARLY SUMMER PULSE
SEVERE THREAT OR FLASH FLOODING THREAT SUNDAY. HOWEVER...HEAVY
RAINFALL MAY BECOME AN ISSUE MONDAY...AS UPPER FLOW WEAKENS ABOVE
THE LOW LEVEL SOUTHEAST FLOW...POSSIBLY FAVORING ANCHORING OF CELLS
ACROSS PORTIONS OF THE HIGH TERRAIN. TEMPS ARE EXPECTED TO RETURN TO
NEAR CLIMO BY MONDAY IN THE RELATIVELY COOL E/SE FLOW
REGIME.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 130 PM EDT FRIDAY...THE MEDIUM RANGE FCST PICKS UP AT 00Z ON
TUESDAY WITH WEAK UPPER RIDGING OVER THE SE CONUS AND A LOW
AMPLITUDE UPPER TROF DIGGING DOWN OVER OVER THE DAKOTAS AND
MINNESOTA. OVER THE NEXT FEW DAYS...THE TROF SLOWLY PROPAGATES
EASTWARD...YET IT DOES NOT APPEAR TO MAKE MUCH HEADWAY SOUTHWARD.
THE LONG RANGE MODELS HAVE BEEN DIFFERING A FAIR AMOUNT WRT THE
AMPLIFICATION OF THIS TROF...BUT ITS LOOKING LIKE THEY ARE LEANING
MORE TOWARDS STRONGER RIDGING OVER OUR FCST AREA THRU DAY 7. THIS PATTERN
LEAVES OUR AREA UNDER GENERALLY WEAK WEST TO SWLY STEERING FLOW THRU
THE PERIOD. AT THE SFC...THE REGION WILL BE UNDER THE INFLUENCE OF
THE BERMUDA HIGH FOR MOST OF THE PERIOD WITH A COLD FRONT
APPROACHING THE CAROLINAS BY EARLY WED AND WASHING OUT AS IT MOVES
OVER THE CWFA. IN ITS WAKE...WEAK CANADIAN HIGH PRESSURE TRIES TO
PUSH SOUTHWARD FROM NEW ENGLAND BUT ITS PROGRESS IS SUPPRESSED BY
THE BERMUDA HIGH. WITH THE COMBINATION OF SLY MOIST FLOW...A WEAKLY
SHEARED ENVIRONMENT AND MODERATE DIURNAL BUOYANCY...WE STILL HAVE A
SOLID CHANCE OF PULSE TYPE CONVECTION ACROSS MUCH OF THE REGION EACH
DAY...FAVORING IN THE MTN ZONES OVERALL. TEMPERATURES SHOULD REMAIN
FAIRLY STEADY WITH VALUES NEAR NORMAL OR POSSIBLE A FEW DEGREES
WARMER.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
AT KCLT...STRONG STORMS DEVELOPING NW ACROSS THE NC FTHILLS WILL
MAKE A RUN FOR THE AIRFIELD THIS EVENING. LOOKS LIKE THEY WILL RUN
OUT OF STEAM AS THEY ENCOUNTER MORE STABLE AIR EAST. THE CAM MODELS
INDICATE A DIMINISHING TREND AS WELL ONCE THE STORMS MOVE OUT OF THE
HIGHER ELEVATIONS. WILL INCLUDE A TEMPO -SHRA VRB GUSTS 01Z THROUGH
02Z TO ACCOUNT FOR WEAKENED CELLS. WINDS WILL PICK UP GENERALLY W/LY
ARND NOON AND VEER NW/LY AS ERN TROF STRENGTHENS. NOT A GREAT
CONVECTIVE OUTLOOK TOMORROW AFTERNOON WITH BNDRYS NORTH AND EAST OF
THE AREA...BUT ENOUGH LLVL HEATING TO INCLUDE PROB30 TSTMS AT
21Z.
ELSEWHERE...THUNDERSTORMS WILL REMAIN A THREAT OVER KAVL AND KHKY
THIS EVENING TIL 02Z...WITH VCSH FOR A COUPLE HRS AFTER THAT.
OUTFLOW FROM A STRONG STORM IN NRN GREENVILLE CO SHOULD BRING VRB
20+ KT GUST TO KGMU AND KGSP AFT 01Z THROUGH 02Z. W/LY FLOW EARLY
TOMORROW WITH WIND SHIFT TO NW/LY IN THE AFTERNOON AS TROF DEEPS TO
THE EAST...KAVL WILL REMAIN UP VALLEY. SCT THUNDER CHANCES AGAIN
TOMORROW AFTERNOON AFT 21Z OR SO ALL SITES EXCEPT KAND WHERE
COVERAGE SHOULD BE TOO LOW TO INCLUDE MENTION IN THE TAF. KAVL MAY
SEE A FEW HRS OF MVFR VSBY OVERNIGHT AS MOIST SOILS COMBINE WITH
LIGHT WINDS AND INCREASING RADIATIONAL COOLING.
OUTLOOK...ISOLATED TO SCATTERED AFTERNOON AND EVENING THUNDERSTORMS
ARE EXPECTED INTO THE WEEKEND...WITH THE GREATEST COVERAGE ACROSS
THE MTNS. RESTRICTIONS MAY OCCUR DURING TSRA AND ALSO IN THE MTN
VALLEYS EACH MORNING WHERE LOW CLOUDS AND FOG MAY FORM OVER AREAS OF
RECENT RAINFALL.
CONFIDENCE TABLE...
02-08Z 08-14Z 14-20Z 20-02Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 95% HIGH 100% HIGH 100% HIGH 100%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...STAARMANN
NEAR TERM...SBK/WIMBERLEY
SHORT TERM...JDL
LONG TERM...JPT
AVIATION...SBK
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
808 PM EDT FRI JUN 20 2014
.SYNOPSIS...
AN UPPER RIDGE WILL CONTINUE TO BREAK DOWN THROUGH THIS EVENING
RESULTING IN WEAKENING HIGH PRESSURE CURRENTLY IN PLACE OVER THE
AREA. THIS SHOULD YIELD A GREATER COVERAGE OF SHOWERS AND
THUNDERSTORMS ACROSS THE AREA OVER THE WEEKEND AND INTO EARLY NEXT
WEEK. A TYPICAL WARM SUMMERLIKE PATTERN WILL CONTINUE THROUGH NEXT
WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
730 PM EDT UPDATE...A NICE LOBE OF VORT ENERGY HAS SPAWNED A LINE OF
STRONG TO SEVERE CONVECTION ACROSS THE NC MTNS AND FTHILLS THIS
EVENING. THE STEERING FLOW HAS INCREASED AS WELL AND STRENGTHENED
INFLOW CONVERGENT UPDRAFTS. ANTICIPATE A WEAKENING TREND AS THESE
STORMS MOVE OUT OF THE HIGHER TERRAIN INTO MORE STABLE AIR OVER THE
NEXT COUPLE HRS. HAVE RECEIVED A FEW REPORTS OF FUNNEL CLOUDS
WHICH ARE POSSIBLE WITH THE LVLV ROTATING UPDRAFTS. HOWEVER...A
COUPLE REPORTS HAVE INDICATED TORNADOES ON THE GROUND...WHICH ARE
NOT POSSIBLE IN THE CURRENT LOW SHEAR ENVIRONMENT. THESE REPORTS
ARE LIKELY SCUD CLOUDS AND/OR CLOUDS ASSOCIATED WITH STRONG RAINSHAFTS.
MADE MINOR TWEAKS TO THE T/TDS GRIDS DUE TO PRECIP OVER THE PAST 3
HRS.
430 PM EDT UPDATE...LOW SFC TD/S AND A NOTABLE LOBE OF DNVA HAS KEPT
CONVECTION MINIMAL AND RELATIVELY SHORT LIVED ACROSS CWFA THUS FAR
THIS AFTERNOON. THE STORMS TO THE EAST HAVE BEEN ABLE TO TAP INTO
HIGH VALUES OF DCAPE AND PRODUCE SEVERE WINDS...BUT THE REMAINING
CELLS HAVE HAD FAIRLY NARROW AND WEAKER UPDRAFTS. THE NAM12 HAS A
GOOD HANDLE ON THE UPPER VORT FIELD AND WILL FOLLOW IT/S GUIDANCE
WRT TO POPS AND CONVEC INITIATION OVER THE NEXT COUPLE HRS. THE
UPSTATE HAS THE LOWEST INSTABILITY COMBINED WITH NEGATIVE ULVL
FORCING...SO POPS WILL BE LOWERED TO ISOL THERE...ACROSS THE SRN NC
FTHILLS. THE BEST CHANCE FOR NEW DEVELOPMENT WILL BE ACROSS THE NC
MTN SPINE WHERE ENHANCED CONVECTION SHOULD MOVE IN AND LIKELY WEAKEN
THROUGH 8 PM.
AS OF 200 PM EDT...CELLS NOW LINING UP ALONG THE BLUE RIDGE AS A
WEAK RIPPLE ROUNDS THE RIDGE OVER THE LOWER MISSISSIPPI VALLEY AND
MOVES SEWD ACRS THE AREA. HRRR SEEMS TO HAVE PICKED UP ON THIS
ACTIVITY AND ALLOWS IT TO PROPAGATE SEWD SLIGHTLY BEFORE
DISSIPATING...POSSIBLY DUE TO DOWNSLOPING BY THE NW FLOW ABOVE THE
BOUNDARY LAYER. THE NCEP HIRES WINDOW /NMM/ SUGGESTS THE SAME...BUT
DEVELOPS A NEW ROUND OF CONVECTION IN THE MTNS BEHIND IT WHICH FILLS
IN THE SAME AREA. DEWPOINTS HAVE MIXED OUT SLIGHTLY AS
EXPECTED...BUT NOT ENOUGH TO KEEP SBCAPE FROM RISING TO 2000 J OR
MORE PER SPC MESOANALYSIS. NO SEVERE REPORTS HAVE YET BEEN RECEIVED
BUT A FEW STORMS HAVE MET WARNING CRITERIA. I AM NO LONGER CONFIDENT
IN OUR EARLIER EXPECTATIONS THAT WE WOULD NOT GET UNSTABLE ENOUGH
FOR LARGE HAIL TO BE MUCH OF A CONCERN...BUT PROFILES REMAIN DRY
ENOUGH FOR DCAPES OF 700-1000 J SUPPORTING A MICROBURST THREAT. CHC
RANGE POPS HAVE BEEN MAINTAINED ACRS MOST OF THE AREA...BUT NOW THE
GREATEST CHANCE APPEARS TO BE DOWNSTREAM OF THE CURRENT ACTIVITY.
SOME MODELS INCLUDING THE NAM TRY TO DEVELOP ANOTHER ROUND OF
CONVECTION AFTER SUNSET...BUT PROFILES HAVE ENOUGH CIN THAT I THINK
THIS IS UNLIKELY IN THE PRESENCE OF SUCH WEAK FORCING. POPS DIMINISH
EAST OF THE MTNS BY LATE EVENING.
MAIN FORECAST CHALLENGE FOR THE OVERNIGHT IS WHETHER ANY ACTIVITY
WILL MOVE INTO OUR AREA FROM THE WEST...AS SUGGESTED BY SOME OF THE
MESO GUIDANCE AND THE 12Z NAM. THE NAM SHOWS AN MCV DEVELOPING OVER
THE OHIO VALLEY LATE THIS AFTN AND PROGRESSING SEWD ACRS KY/TN...THE
ORIGINAL CONVECTION DYING BUT THE MCV KICKING OFF NEW DEVELOPMENT ON
THE WEST SLOPES OF THE MTNS WHICH THEN MOVES INTO NW NC AROUND
DAYBREAK. SO FAR THE NAM DEPICTION OF THE ORIGINATING CONVECTION
SEEMS OVERDONE...SO WILL ONLY GIVE THIS SMALL WEIGHT IN THE FCST.
CLOUD COVER PROGGED BY THE MODELS APPEARS MAINLY TO BE CONVECTIVE
DEBRIS AND IT IS A BIT HARDER TO HEDGE ON THAT.
THE NAM SUGGESTS DEEP RH WILL BE HIGHER ON SATURDAY...PROBABLY SINCE
IT EXPECTS DEBRIS TO COME IN DURING THE MORNING. GFS PROFILES REALLY
DO NOT LOOK TOO MUCH DIFFERENT FROM TODAY...THOUGH SBCAPE IS STILL
LOWER DUE TO SLIGHTLY WEAKER LAPSE RATES. THE DIFFERENCE IS NOT ONLY
IMPORTANT FOR THE POTENTIALLY SIGNIFICANT REDUCTION IN INSTABILITY
DUE TO CLOUDIER SKIES...BUT FOR A REDUCTION IN DCAPE AND MITIGATED
SEVERE RISK. SPC FEATURES A 5 PCT AREA JUST TO OUR EAST WHERE WEAK
SHORTWAVE /THE POTENTIAL MCV/ WILL PASS OVER DURING PEAK HEATING. IT
DOES APPEAR THE BEST PRECIP CHANCES OVERALL WILL BE DURING THE
MORNING IN THE NORTHERN FA AND THEN OVER THE I-77 CORRIDOR DURING
THE AFTN WHERE THE BEST BUOYANCY IS SUGGESTED. TEMPS TONIGHT AND
TOMORROW WILL REMAIN A CATEGORY OR SO ABOVE CLIMO.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AS OF 200 PM FRIDAY...HEIGHTS WILL GRADUALLY FALL THROUGH EARLY NEXT
WEEK...AS UPPER HIGH CONTINUES TO WEAKEN AND RETROGRADE TOWARDS
THE WESTERN GULF OF MEXICO. THIS WILL ALSO ALLOW WEAK FRONTAL ZONE
TO BACK DOOR ITS WAY THROUGH THE AREA BY SUNDAY...POSSIBLY
INTRODUCING SLIGHTLY COOLER AND DRIER AIR. THIS IS NOT EXPECTED TO
ELIMINATE INSTABILITY ENOUGH TO HALT DIURNAL CONVECTION...BUT
COVERAGE OF SUNDAY AFTERNOON/EVENING CONVECTION IS EXPECTED TO BE
MORE TYPICAL OF WHAT ONE WOULD EXPECT THIS TIME OF YEAR (30-40 POPS
MTNS...20/30 PIEDMONT).
BY MONDAY... SHORT TERM MODELS DEPICT ESTABLISHMENT OF AN E/SE FLOW
IN ASSOCIATION WITH A WEAK INVERTED RIDGE ALONG THE EASTERN
SEABOARD. THIS UPSLOPE FLOW COULD SUPPORT A BIT MORE IN THE WAY OF
DIURNAL CONVECTION BY MONDAY AFTERNOON...SO POPS RETURN TO ABOVE
CLIMO BY THIS TIME. WEAK SHEAR WITH HALFWAY DECENT STEERING FLOW
SHOULD PRECLUDE ANYTHING MORE THAN A TYPICAL EARLY SUMMER PULSE
SEVERE THREAT OR FLASH FLOODING THREAT SUNDAY. HOWEVER...HEAVY
RAINFALL MAY BECOME AN ISSUE MONDAY...AS UPPER FLOW WEAKENS ABOVE
THE LOW LEVEL SOUTHEAST FLOW...POSSIBLY FAVORING ANCHORING OF CELLS
ACROSS PORTIONS OF THE HIGH TERRAIN. TEMPS ARE EXPECTED TO RETURN TO
NEAR CLIMO BY MONDAY IN THE RELATIVELY COOL E/SE FLOW
REGIME.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 130 PM EDT FRIDAY...THE MEDIUM RANGE FCST PICKS UP AT 00Z ON
TUESDAY WITH WEAK UPPER RIDGING OVER THE SE CONUS AND A LOW
AMPLITUDE UPPER TROF DIGGING DOWN OVER OVER THE DAKOTAS AND
MINNESOTA. OVER THE NEXT FEW DAYS...THE TROF SLOWLY PROPAGATES
EASTWARD...YET IT DOES NOT APPEAR TO MAKE MUCH HEADWAY SOUTHWARD.
THE LONG RANGE MODELS HAVE BEEN DIFFERING A FAIR AMOUNT WRT THE
AMPLIFICATION OF THIS TROF...BUT ITS LOOKING LIKE THEY ARE LEANING
MORE TOWARDS STRONGER RIDGING OVER OUR FCST AREA THRU DAY 7. THIS PATTERN
LEAVES OUR AREA UNDER GENERALLY WEAK WEST TO SWLY STEERING FLOW THRU
THE PERIOD. AT THE SFC...THE REGION WILL BE UNDER THE INFLUENCE OF
THE BERMUDA HIGH FOR MOST OF THE PERIOD WITH A COLD FRONT
APPROACHING THE CAROLINAS BY EARLY WED AND WASHING OUT AS IT MOVES
OVER THE CWFA. IN ITS WAKE...WEAK CANADIAN HIGH PRESSURE TRIES TO
PUSH SOUTHWARD FROM NEW ENGLAND BUT ITS PROGRESS IS SUPPRESSED BY
THE BERMUDA HIGH. WITH THE COMBINATION OF SLY MOIST FLOW...A WEAKLY
SHEARED ENVIRONMENT AND MODERATE DIURNAL BUOYANCY...WE STILL HAVE A
SOLID CHANCE OF PULSE TYPE CONVECTION ACROSS MUCH OF THE REGION EACH
DAY...FAVORING IN THE MTN ZONES OVERALL. TEMPERATURES SHOULD REMAIN
FAIRLY STEADY WITH VALUES NEAR NORMAL OR POSSIBLE A FEW DEGREES
WARMER.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AT KCLT...STRONG STORMS DEVELOPING NW ACROSS THE NC FTHILLS WILL
MAKE A RUN FOR THE AIRFIELD THIS EVENING. LOOKS LIKE THEY WILL RUN
OUT OF STEAM AS THEY ENCOUNTER MORE STABLE AIR EAST. THE CAM MODELS
INDICATE A A DIMINISHING TREND AS WELL ONCE THE STORMS MOVE OUT OF
THE HIGHER ELEVATIONS. WILL INCLUDE A TEMPO -SHRA VRB GUSTS 01Z
THROUGH 02Z TO ACCOUNT FOR WEAKENED CELLS. WINDS WILL PICK UP
GENERALLY W/LY ARND NOON AND VEER NW/LY AS ERN TROF STRENGTHENS. NOT
A GREAT CONVECTIVE OUTLOOK TOMORROW AFTERNOON WITH BNDRYS NORTH AND
EAST OF THE AREA...BUT ENOUGH LLVL HEATING TO INCLUDE PROB30 TSTMS
AT 21Z.
ELSEWHERE...THUNDERSTORMS WILL REMAIN A THREAT OVER KAVL AND KHKY
THIS EVENING TIL 02Z...WITH VCSH FOR A COUPLE HRS AFTER THAT.
OUTFLOW FROM A STRONG STORM IN NRN GREENVILLE CO SHOULD BRING VRB
20+ KT GUST TO KGMU AND KGSP AFT 01Z THROUGH 02Z. W/LY FLOW EARLY
TOMORROW WITH WIND SHIFT TO NW/LY IN THE AFTERNOON AS TROF DEEPS TO
THE EAST...KAVL WILL REMAIN UP VALLEY. SCT THUNDER CHANCES AGAIN
TOMORROW AFTERNOON AFT 21Z OR SO ALL SITES EXCEPT KAND WHERE
COVERAGE SHOULD BE TOO LOW TO INCLUDE MENTION IN THE TAF. KAVL MAY
SEE A FEW HRS OF MVFR VSBY OVERNIGHT AS MOIST SOILS COMBINE WITH
LIGHT WINDS AND INCREASING RADIATIONAL COOLING.
OUTLOOK...ISOLATED TO SCATTERED AFTERNOON AND EVENING THUNDERSTORMS
ARE EXPECTED INTO THE WEEKEND...WITH THE GREATEST COVERAGE ACROSS
THE MTNS. RESTRICTIONS MAY OCCUR DURING TSRA AND ALSO IN THE MTN
VALLEYS EACH MORNING WHERE LOW CLOUDS AND FOG MAY FORM OVER AREAS OF
RECENT RAINFALL.
CONFIDENCE TABLE...
00-06Z 06-12Z 12-18Z 18-24Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 95% HIGH 100% HIGH 100%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...STAARMANN
NEAR TERM...SBK/WIMBERLEY
SHORT TERM...JDL
LONG TERM...JPT
AVIATION...SBK
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
212 AM EDT THU JUN 19 2014
.SYNOPSIS...
DEEP HIGH PRESSURE AND AN ASSOCIATED UPPER LEVEL RIDGE WILL PERSIST
THROUGHOUT THE AREA THROUGH THE END OF THE WEEK. THIS WILL KEEP A
SEASONABLY WARM AIR MASS IN PLACE THROUGH THE WEEKEND. HIGH PRESSURE
WILL WEAKEN AS THE RIDGE BREAKS DOWN BY FRIDAY AFTERNOON WHICH
SHOULD YIELD A GREATER COVERAGE OF SHOWERS AND STORMS ACROSS THE
ENTIRE AREA OVER THE WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 210 AM...I WILL UPDATE THE FORECAST TO FINE TUNE FOG
DENSITY...PLACEMENT...AND TIMING. OTHERWISE...CONDITIONS EARLY THIS
MORNING WILL FEATURE DECREASE SKY COVER AND LIGHT TO CALM WINDS.
EVENING UPDATE...EXPECT REMNANT CONV CLOUD COVER TO CONTINUE
DIMINISHING OVERNIGHT. ALREADY SEEING TEMPS BELOW THE FCST CURVE
ACROSS THE ERN UPSTATE DUE TO DECENT RADIATIONAL COOLING. THE 00Z
NAM12_BC AND LAMP GUIDANCE BOTH INDICATE COOLER MIN TEMPS BY A
COUPLE DEGREES THAN THE GOING FCST WHICH MAKES SENSE...SO THIS WAS
WEIGHTED HIGHLY INTO FCST LOWS. COULD SEE SOME LOW DENSITY FG
DEVELOP AFT 09Z ACROSS THE NC MTN VALLEYS...THE FTHILLS...AND NRN
UPSTATE WHERE AREAS OF PRECIP HAS CREATED MOIST SOIL FLUX CONDS.
730 PM EDT UPDATE...A FEW LINGERING -SHRA/TSTMS ON THE OUTSKIRTS OF
THE CWFA WITH A DIMINISHING TREND AS INSTABILITY WANES AND ATMOS
REMAINS NEGLIGIBLY FORCED ALOFT. A COUPLE TSTMS MAY PUSH INTO THE
SMOKIES...BUT NOTHING STRONG OR SEVERE WILL DEVELOP. THERE IS A GOOD
AMOUNT OF DEBRIS CI WHICH WILL PERSIST OVER THE NEXT FEW HRS. CUT
BACK HR/LY TEMPS A BIT ACROSS MOST LOCALES TO ACCOUNT FOR REDUCED
HEATING AND POPS WERE ADJ FOR CONVECTIVE TRENDS.
430 PM EDT UPDATE...SEVERE STORMS ARE BUILDING ALONG A WEAK BOUNDARY
FROM THE NW NC PIEDMONT SW INTO THE ERN UPSTATE. NOT MUCH STORM
MOTION WITH THESE STORMS AND SVR WINDS HAVE NOT BEEN A HUGE
THREAT...HOWEVER A LOCALIZED WET DOWNBURST IS NOT OUT OF THE
QUESTION AS THE STORMS NEAR AN AREA OF HIGHER DCAPE. LARGE HAIL WILL
BE THE MAIN THREAT OVER THE NEXT FEW HRS.
AS OF 200 PM...CONVECTION IS BLOSSOMING MORE READILY THAN YESTERDAY
ACRS THE MTNS. I UPDATED THE POP TO TRY TO MATCH TRENDS. MOST OF THE
HIGH TERRAIN LOOKS TO GET WORKED OVER BY THE CONVECTION BY SUNSET.
HOWEVER...CONFIDENCE IS STILL LOW ON HOW MUCH WILL DEVELOP ACRS THE
PIEDMONT. STORM MOTION IS VERY SLOW...AND CELLS HAVE GENERALLY
WEAKENED SO FAR AS THEY TRY TO ROLL OFF THE ESCARPMENT.
HOWEVER...THE VIS SAT IMAGERY SHOWS A CUMULUS FIELD GETTING MORE
ROBUST...WITH A COUPLE OF ISOLD STORMS DEVELOPING EAST OF CHARLOTTE.
THE 15Z-16Z HRRR RUNS ARE SHOWING A CLUSTER OF STORMS DEVELOPING
SOUTH CHARLOTTE...WITH OUTFLOW FANNING OUT AND TRIGGERING NEW CELLS
ACRS MUCH OF THE PIEDMONT LATE AFTN INTO EARLY EVENING. THE HRRR
TENDS TO BE OVERDONE...BUT IT DOES SHOW THE POTENTIAL. SO I DID
INCREASE POPS FOR PORTIONS OF THE PIEDMONT...BUT STILL GENERALLY
SLGT CHC TO LOW-END CHC. AS FOR SEVERE POTENTIAL...IT LOOKS LIKE
CELLS ARE TOPPING OUT JUST SHORT OF OBJECTIVE CRITERIA SO FAR. LAPS
CAPE ANALYSIS SHOWS 3000-4000 J/KG ACRS MUCH OF THE PIEDMONT. SO I
THINK THERE WILL BE A FEW PULSE SEVERE STORMS...WITH QUARTER-SIZE
HAIL AND/OR DAMAGING WINDS.
TONIGHT...CONVECTION SHUD WANE QUICKLY AROUND SUNSET. SIMILAR TO
LAST COUPLE NIGHTS...CLOUDS SHUD DISSIPATE AND WINDS REMAIN
CALM/LIGHT. THERE WILL BE SOME VLY FOG IN THE NC MTNS. TEMPS WILL BE
ABOVE NORMAL IN THE 60S MTNS AND UPR 60S TO LWR 70S PIEDMONT.
THURSDAY...A SHORTWAVE TROF WILL DIVE INTO THE GREAT LAKES...HELPING
WEAKEN THE LARGE UPPER RIDGE ATOP THE CWFA. HOWEVER...GUIDANCE SHOWS
ONLY SUBTLE CHANGES IN THE ENVIRONMENT FOR OUR AREA. SO EXPECT
ANOTHER HOT DAY WITH SCT-NUM AFTN SHWRS/TSTMS IN THE MTNS AND
ISOLD-SCT IN THE PIEDMONT.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY/...
AS OF 300 PM WEDNESDAY...THE UPPER RIDGE OVER THE CAROLINAS AND GA
WILL GRADUALLY BREAK DOWN FROM THE EAST FROM THURSDAY NIGHT THROUGH
SATURDAY...AS A LOW AMPLITUDE UPPER TROUGH SETS UP OFF THE EAST
COAST. THIS WILL ALLOW A COLD FRONT TO MOVE SOUTH INTO NORTH
CAROLINAS ON THURSDAY NIGHT AND FRIDAY. THE GFS STALLS THE FRONT
NEAR THE SC BORDER ON FRIDAY NIGHT...WHILE THE NAM IS SLIGHT FARTHER
NORTH. IN ANY EVENT AN INCREASE IN CONVECTIVE ACTIVITY IS EXPECTED
WITH THE ARRIVAL OF THIS BOUNDARY. MODEL SOUNDING SHOW A BIT MORE
SHEAR BY THIS TIME...ALTHOUGH INSTABILITY IS MODEST. ALTHOUGH
STEERING FLOW IS BETTER THAN IN PREVIOUS DAYS...MOVING CELLS
ALONG...SOME CONCERN EXISTS FOR REPEAT CELLS TRAINING EAST ALONG THE
BOUNDARY RESULTING IN HEAVY RAINFALL. TEMPERATURES ARE EXPECTED TO
REMAIN ABOVE NORMAL...BUT NOT AS MUCH SO ALONG INTERSTATE 40 WHERE
CLOUD COVER WILL BE BEST ALONG THE BOUNDARY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 115 PM EDT WEDNESDAY...THE MEDIUM RANGE FCST PICKS UP AT 00Z
ON SUNDAY WITH PERSISTENT UPPER RIDGING TO OUR WEST AND BROAD UPPER
TROFFING TO OUR NE. THE PATTERN IS EXPECTED TO FLATTEN OUT EARLY IN
THE PERIOD BEFORE ANOTHER...DEEPER UPPER TROF DIGS DOWN OVER THE
GREAT LAKES WITH THE TROF AXIS TO OUR NORTH BY THE END OF THE MEDIUM
RANGE. THE LONG RANGE MODELS DIFFER A FAIR AMOUNT WRT THE EVOLUTION
OF THE UPPER TROF WITH THE ECMWF DEVELOPING A MORE AMPLIFIED AND
COHERENT SYSTEM COMPARED TO THE GFS. THE GFS TRIES TO DEVELOP THE
TROF 1 TO 2 DAYS EARLIER AND KEEPS IT FARTHER NORTH AS IT PROGRESSES
EASTWARD. DIURNAL POPS WERE INCREASED A BIT ON BOTH MON AND TUES
NEXT WEEK TO REFLECT GENERALLY MORE MOIST GUIDANCE. OTHER THAN
THAT...NO MAJOR CHANGES WERE MADE TO THE SENSIBLE FCST.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AT KCLT...MOSTLY CLEAR SKY COVER WITH LIGHT SW WINDS SHOULD CONTINUE
ACROSS THE TERMINAL THROUGH SUNRISE. AREAS WITHIN THE VICINITY HAD
HEAVY RAIN YESTERDAY...ESPECIALLY TO THE WEST. VIS ACROSS THE
TERMINAL IS EXPECTED TO REMAIN P6SM THROUGH SUNRISE...AREAS OF FOG
IS ANTICIPATED OVER WET GROUND. THIS AFTERNOON...THE CENTER OF THE
H5 RIDGE WILL SHIFT SW...RESULTING IN SLIGHT HEIGHT FALL ACROSS THE
WESTERN CAROLINAS. FORECAST SOUNDINGS INDICATE THAT MODERATE CAPE
WITH LITTLE TO NO CIN IS EXPECTED THROUGH THE AFTERNOON. A WEAK S/W
MAY RIPPLE OVER THE REGION LATE THIS AFTERNOON. THE POTENTIAL FOR
TSRA APPEARS A BIT GREATER THAN WHAT WAS OBSERVED ON WEDNESDAY. I
WILL HIGHLIGHT THE CONVECTION WITH A PROB30 FROM 20-24Z. WINDS MAY
FAVOR A WNW DIRECTION BY 15Z...REMAINING THROUGH THE REMAINDER OF
THE 6Z TAF PERIOD.
ELSEWHERE...MOST TERMINALS WILL SEE GOOD POTENTIAL FOR MVFR FOG
AROUND DAWN. I WILL HIGHLIGHT THE FOG DENSITY AND TIMING WITH EITHER
FM OR TEMPO GROUPS. THE COMBINATION MODERATE INSTABILITY AND THE
AFTER APPROACH OF H5 S/W SHOULD YIELD SCT SHRA/TSRA DURING THE
AFTERNOON. I WILL HIGHLIGHT THE CONVECTION WITH A PROB30 FROM
20-24Z...AN HOUR OR TWO EARLIER AT KAVL AND KHKY. WINDS MAY FAVOR A
WNW DIRECTION BY 15Z...REMAINING THROUGH THE REMAINDER OF THE 6Z TAF
PERIOD.
OUTLOOK...ISOLATED TO SCATTERED AFTERNOON AND EVENING THUNDERSTORMS
ARE EXPECTED THROUGH THE REMAINDER OF THE WEEK...WITH THE GREATEST
COVERAGE ACROSS THE MTNS. RESTRICTIONS MAY OCCUR DURING TSRA AND
ALSO IN THE MTN VALLEYS EACH MORNING WHERE LOW CLOUDS AND FOG MAY
FORM OVER AREAS OF RECENT RAINFALL.
CONFIDENCE TABLE...
06-12Z 12-18Z 18-24Z 00-06Z
KCLT HIGH 95% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 87% HIGH 95% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KHKY HIGH 95% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 95% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 91% HIGH 95% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...STAARMANN
NEAR TERM...NED
SHORT TERM...JAT
LONG TERM...JPT
AVIATION...NED
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
338 PM CDT THU JUN 19 2014
.SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT
TIGHT VORTICITY MAXIMA ROTATING OVER WESTERN SD AT THIS TIME HAS
PRODUCED THUNDERSTORMS...WHICH WAS WHAT THE HRRR MODEL WAS
INDICATING MOST OF THE DAY. SOME OF THESE STORMS HAVE BECOME
SEVERE WITH HAIL AND EVEN REPORTS OF FUNNEL CLOUDS/LANDSPOUTS. NOT
SURPRISING GIVEN COOLER TEMPS ALOFT AND TIGHT ROTATION OF VORT
SPINNING ACROSS. MLCAPE VALUES GENERALLY RANGE FROM 500 TO 1000
J/KG WITH DEEP LAYER SHEAR 20 TO 30 KNOTS OVER WESTERN SD.
ALTHOUGH...BETTER SHEAR VALUES EXIST OVER CENTRAL SD. HI RES
MODELS SHOW SOME OF THIS ACTIVITY SPREADING ACROSS THE CWA AS LONG
AS THE SUN IS UP. HAVE INCLUDED POPS THIS EVENING TO ACCOUNT FOR
THIS.
CONDITIONS QUIET DOWN LATE TONIGHT THROUGH FRIDAY NIGHT AS UPPER
LEVEL FLOW BECOMES ZONAL. GIVEN 850 MB TEMPS ON FRIDAY...EXPECT
HIGHS TO BE RATHER WARM WITH READINGS IN THE 80S.
MORE ACTIVE WEATHER RETURNS TO THE AREA SATURDAY AND SATURDAY
NIGHT. INSTABILITY INCREASES TO 2000 TO 3000 J/KG WITH 40 TO 50
KNOTS OF DEEP LAYER SHEAR. LOW LEVEL SHEAR NOT ALL TOO IMPRESSIVE.
COULD BE SEEING SOME SEVERE STORMS ACROSS THE AREA SATURDAY INTO
SATURDAY EVENING.
.LONG TERM...SUNDAY THROUGH THURSDAY
THE PERIOD STARTS OFF WITH FAIRLY FAST MOVING UPPER LEVEL FLOW
WITH A SERIES OF SHORTWAVES TRACKING ACROSS THE AREA. A LOW
PRESSURE SYSTEM WILL TRACK ACROSS THE CENTRAL PLAINS EARLY IN THE
PERIOD...PUTTING THE CWA IN A POTENTIAL SPOT FOR SHOWER AND
THUNDERSTORM ACTIVITY SUNDAY THROUGH EARLY TUESDAY. HIGH PRESSURE
DROPPING OVER THE NORTHERN PLAINS WILL KEEP THINGS DRY TUESDAY
NIGHT AND WEDNESDAY...THEN MAY SEE ANOTHER CHANCE OF PRECIPITATION
WEDNESDAY NIGHT AND THURSDAY AS A LOW PRESSURE SYSTEM APPROACHES
THE REGION.
NEAR NORMAL TEMPERATURES WILL BE THE RULE THROUGH THE
PERIOD...WITH HIGHS IN THE MID 70S TO LOWER 80S AND OVERNIGHT LOWS
IN THE MID TO UPPER 50S.
&&
.AVIATION...
18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
MVFR CIGS WILL REMAIN OVER THE EASTERN PART OF THE CWA INTO THE
AFTERNOON HOURS...AFFECTING KABR AND KATY. BY LATE AFTERNOON...THE
CIGS WILL HAVE LIFTED AND VFR CONDITIONS WILL THEN PREVAIL ACROSS
THE AREA THROUGH THE TAF PERIOD. A FEW ISOLATED THUNDERSTORMS ARE
POSSIBLE ACROSS THE AREA LATER IN THE AFTERNOON AND EVENING...BUT
DUE TO UNCERTAINTY OF DEVELOPMENT AND LOCATION...HAVE NOT
MENTIONED ANY STORMS IN THE TAFS AT THIS TIME.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
SHORT TERM...TMT
LONG TERM...PARKIN
AVIATION...PARKIN
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
409 PM CDT THU JUN 19 2014
.SHORT TERM...
(Tonight and Friday)
Have a developing concern for heavy rainfall potential across
our southern and possibly some central counties tonight. This
is in association with a compact MCV, which appears on satellite
imagery near Eagle Pass along the Rio Grande. This feature will
move north-northwest and should enter our far southern counties
(Sutton or Crockett Counties) toward Midnight. Low-level jet
developing tonight will aid in low-level moisture transport.
The Satellite Precipitation Estimates product from the NESDIS
Satellite Analysis Branch has more details on the potential for
locally heavy rain with this feature. Have increased PoPs across
much of the southern half of our area, with a mention of locally
heavy rainfall. The HRRR and TTU WRF both show development
of convection across our soutern and some of our central counties
tonight. PoPs may need to be raised further as radar trends
become more apparent.
To the northwest of our area, a gravity wave entering northwestern
Texas ahead of a cold front could initiate thunderstorms late this
afternoon and evening. The HRRR and TTU WRF models show a band of
convection approaching our northwestern counties after 9 PM. With
uncertainty in how much shower/thunderstorm coverage will occur
away from the MCV, carrying lower PoPs across the rest of our area
tonight.
For Friday, carring low PoPs across West Central Texas. Models show
a mid/upper level shear axis over our area, with precipitable water
values between 1 and 1.6 inches. Little change in the temperature
regime is expected.
.LONG TERM...
(Friday night through next Thursday)
Our area will remain under a weak mid/upper level shear axis through
Saturday, as upper ridge begins to build over northwest Mexico into
the Desert Southwest, and the upper high weakens over the lower
Mississippi Valley. Have a slight chance PoP lingering across our
western counties on Saturday.
During the first half of next week, the upper high is progged to
build over northwestern Mexico and the southwestern U.S., and weak
northwest flow aloft will develop over our area. The forecast 850 mb
temperatures indicate a gradual warming trend with daytime
temperatures for our area. Weak surface cold front is progged to sag
south of the Red River and stall Tuesday evening, The 12Z GFS
suggests potential for convective complext to approach our area from
the northwest Tuesday night. Did not make changes to our PoPs next
week, but will monitor model trends.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 73 90 72 91 72 / 20 20 5 10 10
San Angelo 73 91 72 92 72 / 30 20 10 10 10
Junction 73 90 71 91 71 / 40 20 10 10 10
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
19
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
310 PM CDT THU JUN 19 2014
.DISCUSSION...
A MID/UPPER LEVEL RIDGE DOMINATES THE LOWER MS VALLEY AND
SOUTHEAST CONUS TODAY. WEST OF THE RIDGE...GENERAL WEAK TROUGHING
RESIDES ACROSS WEST-CENTRAL TEXAS AND WESTERN PARTS OF NORTH
TEXAS. THE HIGHEST CHANCES OF PRECIPITATION THROUGH TONIGHT
RELATE CLOSELY TO THE POSITION OF THE WEAK TROUGH OVER THE
NORTHWESTERN HALF OF THE REGION. CONVECTION MAY AT TIMES BECOME
ENHANCED BY MESOSCALE FEATURES SUCH AS CONVECTIVE VORTICES LIFTING
NORTH OUT OF MEXICO...OR OUTFLOW BOUNDARIES PUSHING IN FROM THE
NORTHWEST. THIS COULD LEAD TO SOME LOCALIZED HEAVY RAIN DUE TO THE
1.75 INCH PWATS IN PLACE. INSTABILITY WILL BE SUFFICIENT FOR SOME
STRONG STORMS WITH GUSTY WINDS THIS AFTERNOON INTO THIS EVENING.
AN ISOLATED SEVERE STORM CANNOT BE RULED OUT...THOUGH WEAK WINDS
ALOFT THE LACK OF SHEAR COMBINED WITH THE MOIST ENVIRONMENT SHOULD
LIMIT OVERALL SEVERE POTENTIAL.
THE AFOREMENTIONED RIDGE WILL NUDGE ITS WAY IN FROM THE EAST
FRIDAY AND REMAIN IN PLACE OVER THE WEEKEND. INCREASING SUBSIDENCE
AND DRIER AIR WILL MOST LIKELY KEEP A LID ON CONVECTION SATURDAY
AND SUNDAY. WILL KEEP POPS AROUND 10 PERCENT BECAUSE THERE IS
STILL AN OUTSIDE SHOT OF AN ISOLATED STORM OR TWO.
THE RIDGE WILL WEAKEN DURING THE FIRST HALF OF NEXT WEEK AS A
LARGE SCALE UPPER TROUGH DEEPENS OVER THE NORTHEASTERN PART OF THE
COUNTRY. ONE PRONOUNCED SHORTWAVE IS PROGGED TO SWING EAST FROM
THE CENTRAL PLAINS INTO THE OHIO VALLEY AROUND THE BASE OF THE
NORTHEAST TROUGH. THIS ENERGY WILL SEND A FRONT SOUTHWARD TO NEAR
THE RED RIVER MONDAY EVENING. SHOWERS AND STORMS WILL BE POSSIBLE
AHEAD OF THE FRONT...AND WE WILL MAINTAIN THE SLIGHT CHANCE POPS
OVER THE NORTHERN 2 ROWS OF COUNTIES MONDAY. THE FRONT WILL
PROBABLY STALL IN THIS AREA AND LOW POPS WILL CONTINUE ACROSS THE
NORTH ON TUESDAY.
A SECOND SHORTWAVE WILL TRAVERSE THE SOUTHERN PLAINS AROUND MID
WEEK...PASSING CLOSER TO NORTH TEXAS AND BRINGING A CHANCE OF
SHOWERS AND THUNDERSTORMS AREA-WIDE NEXT WEDNESDAY. FOR THE REST
OF NEXT WEEK...IT LOOKS LIKE WE MAY RETURN TO THE CURRENT WEATHER
PATTERN WITH A STRENGTHENING MID AND UPPER RIDGE OVER THE
SOUTHEAST STATES AND A WEAK TROUGH OVER WESTERN PORTIONS OF NORTH
TEXAS. THIS WOULD LEAD TO AT LEAST SOME LOW-END RAIN CHANCES LATE
NEXT WEEK AND INTO THE FOLLOWING WEEKEND.
30
&&
.AVIATION...
/ISSUED 1248 PM CDT THU JUN 19 2014/
/18Z TAFS/
NORTH TEXAS CONTINUES TO BE UNDER A WEAKNESS ALONG THE NORTHWEST
PERIPHERY OF THE SUBTROPICAL UPPER RIDGE ANCHORED ACROSS THE DEEP
SOUTH AND GULF OF MEXICO. SUBTLE PERTURBATIONS ALOFT CONTINUE TO
RIDE NNE UP ACROSS CENTRAL AND NORTH TEXAS THIS AFTERNOON WITH A
LINGERING BAND OF SHOWERS AND ISOLATED THUNDERSTORMS WEST OF I-35.
THIS AREA SHOULD REMAIN MORE STABLE THAN A WARMER AND MORE UNSTABLE
AIRMASS FROM THE AIRPORTS EAST. FEEL THAT DIFFERENTIAL HEATING AND
WEAK LIFT WILL RESULT IN ISOLATED STORMS DEVELOPING AND MOVING
READILY NORTH TO THE EAST OF THE CURRENT ACTIVITY OVER THE WEST. A
FEW COULD REACH STRONG OR BRIEFLY SEVERE LIMITS WITH FREQUENT
LIGHTNING AND VERY GUSTY DOWNBURST WINDS. ANY STORM ACTIVITY WOULD
WANE EARLY THIS EVENING WITH THE LOSS OF HEATING... THOUGH SOME
WEAKENING ACTIVITY FROM WEST TEXAS COULD GET CLOSE TO ALLIANCE AND
MEACHAM AIRPORTS EARLY FRIDAY MORNING.
THE CHALLENGE WAS TO WHETHER OR NOT TO INSERT VCTS AT AIRPORTS
TODAY AND IF AND WHEN ANY MVFR CIGS WOULD OCCUR BY SUNRISE FRIDAY.
THE HRRR HAS DONE ABOUT AS WELL AS ANY MODEL REGARDING THE CURRENT
MESOSCALE SET UP AND WILL INSERT VCTS THROUGH 23Z FOR ALL THE
AIRPORTS. TOO MANY UNCERTAINTIES ARE EXPECTED AFTER THAT AND WILL
NOT HAVE ANY MENTION OF VCTS OR VCSH. LOW LEVEL WIND FIELDS ARE
EXPECTED TO BE WEAKER AND EFFECTS FROM ANY OUTFLOW COULD PLAY A
ROLE MVFR DEVELOPMENT BY SUNRISE FRIDAY. HAVE DECIDED TO KEEP A
SHORT 2-3 HR WINDOW ON EITHER SIDE OF 12Z...WITH VFR CONDITIONS
RETURNING BY MID MORNING FRIDAY.
05/
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 75 93 75 94 76 / 20 10 10 10 5
WACO, TX 72 91 72 92 74 / 10 10 5 10 5
PARIS, TX 72 91 71 91 72 / 20 10 10 10 5
DENTON, TX 73 93 72 93 74 / 30 10 10 10 5
MCKINNEY, TX 72 93 73 94 73 / 20 10 10 10 5
DALLAS, TX 75 92 75 93 77 / 20 10 5 10 5
TERRELL, TX 72 94 75 95 73 / 20 10 5 10 5
CORSICANA, TX 72 91 73 91 73 / 10 10 5 10 5
TEMPLE, TX 72 90 71 91 73 / 10 10 5 10 5
MINERAL WELLS, TX 71 91 71 92 72 / 30 10 5 10 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1248 PM CDT THU JUN 19 2014
.AVIATION...
/18Z TAFS/
NORTH TEXAS CONTINUES TO BE UNDER A WEAKNESS ALONG THE NORTHWEST
PERIPHERY OF THE SUBTROPICAL UPPER RIDGE ANCHORED ACROSS THE DEEP
SOUTH AND GULF OF MEXICO. SUBTLE PERTURBATIONS ALOFT CONTINUE TO
RIDE NNE UP ACROSS CENTRAL AND NORTH TEXAS THIS AFTERNOON WITH A
LINGERING BAND OF SHOWERS AND ISOLATED THUNDERSTORMS WEST OF I-35.
THIS AREA SHOULD REMAIN MORE STABLE THAN A WARMER AND MORE UNSTABLE
AIRMASS FROM THE AIRPORTS EAST. FEEL THAT DIFFERENTIAL HEATING AND
WEAK LIFT WILL RESULT IN ISOLATED STORMS DEVELOPING AND MOVING
READILY NORTH TO THE EAST OF THE CURRENT ACTIVITY OVER THE WEST. A
FEW COULD REACH STRONG OR BRIEFLY SEVERE LIMITS WITH FREQUENT
LIGHTNING AND VERY GUSTY DOWNBURST WINDS. ANY STORM ACTIVITY WOULD
WANE EARLY THIS EVENING WITH THE LOSS OF HEATING... THOUGH SOME
WEAKENING ACTIVITY FROM WEST TEXAS COULD GET CLOSE TO ALLIANCE AND
MEACHAM AIRPORTS EARLY FRIDAY MORNING.
THE CHALLENGE WAS TO WHETHER OR NOT TO INSERT VCTS AT AIRPORTS
TODAY AND IF AND WHEN ANY MVFR CIGS WOULD OCCUR BY SUNRISE FRIDAY.
THE HRRR HAS DONE ABOUT AS WELL AS ANY MODEL REGARDING THE CURRENT
MESOSCALE SET UP AND WILL INSERT VCTS THROUGH 23Z FOR ALL THE
AIRPORTS. TOO MANY UNCERTAINTIES ARE EXPECTED AFTER THAT AND WILL
NOT HAVE ANY MENTION OF VCTS OR VCSH. LOW LEVEL WIND FIELDS ARE
EXPECTED TO BE WEAKER AND EFFECTS FROM ANY OUTFLOW COULD PLAY A
ROLE MVFR DEVELOPMENT BY SUNRISE FRIDAY. HAVE DECIDED TO KEEP A
SHORT 2-3 HR WINDOW ON EITHER SIDE OF 12Z...WITH VFR CONDITIONS
RETURNING BY MID MORNING FRIDAY.
05/
&&
.UPDATE...
FORECASTS WERE UPDATED TO INCREASE POPS OVER NORTHWEST COUNTIES
THIS MORNING WHERE OUTFLOW FROM A WEAKENING MCS OVER OKLAHOMA
APPEARS TO BE ENHANCING SHOWERS AND THUNDERSTORMS FROM BOWIE DOWN
TO POSSUM KINGDOM. ACTIVITY SHOULD WEAKEN LATE THIS MORNING WITH
REDEVELOPMENT EXPECTED THIS AFTERNOON. WILL KEEP THE AFTERNOON
FORECAST AS IS WITH WIDESPREAD LOW POPS ASSOCIATED WITH DIURNAL
AIRMASS CONVECTION.
30
&&
.PREV DISCUSSION... /ISSUED 241 AM CDT THU JUN 19 2014/
THIS MORNING...UPPER LOW SITS AT ALBERTA/SASKATCHEWAN/MONTANA
TRIPLE POINT...MOVING EAST NORTHEAST. BROAD FLAT RIDGE RUNS FROM
EAST TX ACROSS CAROLINAS OFFSHORE. HIGH PRESSURE IS FORECAST TO
BUILD OVER LA/AR BORDER BY FRIDAY BUT UNTIL THEN THERE REMAINS
ENOUGH INSTABILITY FOR SHOWER/THUNDERSTORM ACTIVITY OVER ALL OF
NORTH TEXAS.
ONGOING SHOWERS NEAR COMANCHE APPEAR TO BE ELEVATED...ROOTED
ABOVE 12000 FT. BY THIS AFTERNOON STORMS WILL BE ROOTED AT THE
SURFACE. PWATS TODAY ARE FORECAST TO BE AROUND 1.75 INCHES. CAPE
ESTIMATES RANGE FROM ABOUT 700 FROM THE NAM TO 1700 FROM THE GFS.
SIMILAR TO YESTERDAY...SCATTERED TO ISOLATED AFTERNOON SHOWERS AND
STORMS WILL HAVE LOW HAIL POTENTIAL BUT GUSTY DOWN BURST WINDS
WILL REMAIN A THREAT...WITH ISOLATED SEVERE WIND GUSTS POSSIBLE.
STORMS MAY LINGER PAST SUNSET IN THE NORTHWEST HALF OF NORTH TX.
NORTH TX SHOULD REMAIN DRY FRIDAY THROUGH SUNDAY UNDER THE
INFLUENCE OF THE HIGH. BY MONDAY THE HIGH DRIFTS SOUTH INTO
MEXICO AND A SERIES SHORT WAVE TROUGHS PUSH INTO THE SOUTHERN
PLAINS. AT THIS POINT TIMING EACH TROUGH IS PROBLEMATIC...BUT HAVE
SPREAD LOW POPS ACROSS THE NORTH MONDAY AFTERNOON THROUGH TUESDAY
NIGHT...AND THEN AREA WIDE WEDNESDAY THROUGH FRIDAY MORNING.
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 93 75 93 75 94 / 20 20 0 5 5
WACO, TX 92 72 91 72 92 / 10 10 0 5 5
PARIS, TX 90 72 91 71 91 / 10 10 10 5 5
DENTON, TX 91 73 93 72 93 / 20 20 5 5 5
MCKINNEY, TX 91 72 93 73 94 / 20 20 5 5 5
DALLAS, TX 92 75 92 75 93 / 20 20 0 5 5
TERRELL, TX 93 72 94 75 95 / 10 10 0 5 5
CORSICANA, TX 91 72 91 73 91 / 10 10 0 5 5
TEMPLE, TX 92 72 90 71 91 / 10 10 0 5 5
MINERAL WELLS, TX 91 71 91 71 92 / 40 20 0 5 5
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
05/30
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1141 AM CDT THU JUN 19 2014
.DISCUSSION...
SEE AVIATION FOR 18Z TAF ISSUANCE.
&&
.AVIATION...
NOT MUCH CHANGE TO CURRENT TAF PACKAGE. THERE CURRENTLY IS AN
UPPER LEVEL LOW NEAR THE LAREDO AREA WHICH IS HELPING TO GENERATE
SHOWERS AND THUNDERSTORMS NEAR THE TEXAS/ MEXICO BORDER. THIS LOW
WILL START TO SLOWLY MOVE TOWARDS THE NORTHEAST TODAY. THE LOW IN
COMBINATION WITH DAYTIME HEATING AND THE SEA BREEZE WILL SERVE AS
THE SOURCES FOR LIFT ACROSS THE AREA. THE MAIN INHIBITORS TO RAIN
TODAY WILL BE DRIER MID LEVEL AIR AND WEAK RIDGING. CURRENT AMDAR
SOUNDINGS AND OBSERVED CRP/ LCH SOUNDINGS SHOW THIS DRY AIR. THE
RADAR HAS SOME WEAK RETURNS ON IT NOW WITH THINGS REALLY HAVING
TROUBLE GETTING GOING (MOST LIKELY BECAUSE OF THE DRY AIR KILLING
UPDRAFTS). THINK THIS WILL BE MOST LIKELY THE STORY OF THE DAY.
COVERAGE SHOULD REMAIN LOW WITH MOST RAIN STAYING SHOWER BASED.
STILL CAN`T RULE OUT AN ISOLATED THUNDER STRIKE HERE OR THERE WITH
THE SEA BREEZE. TOMORROW MORNING THE DRIER AIR ALONG WITH HIGH
CLOUDS WILL HELP TO LIMIT MVFR CLOUD DEVELOPMENT WITH SOME RURAL
SITES POSSIBLY EXPERIENCING SOME REDUCTIONS IN VISIBILITIES. ANY
OF THESE RESTRICTIONS FROM VERY LIGHT FOG SHOULD QUICKLY RECOVER
AFTER SUNRISE. 23
&&
.PREV DISCUSSION... /ISSUED 1040 AM CDT THU JUN 19 2014/
DISCUSSION...
FOR THE MORNING UPDATE...WENT AHEAD AND JUST GAVE THE AREA A SLIGHT
CHANCE OF SHOWERS AND THUNDERSTORMS FOR TODAY. AS TEMPERATURES WARM
INTO THE 90S THIS AFTERNOON...ANTICIPATE SEEING THE DEVELOPMENT OF
SOME STORMS. PIECES OF ENERGY EJECTING OUT FROM THE NEARLY STATIONARY
MID/UPPER LOW TO OUR SOUTHWEST NEAR THE TEXAS-MEXICO BORDER MIGHT
BE ENOUGH TO GENERATE TODAY`S ACTIVITY AS WEAK MID/UPPER LEVEL RIDGING
TRIES TO BUILD INTO OUR AREA FROM THE EAST AND NORTHEAST AND SHUT
THINGS DOWN. THE 12Z NAM MOS GUIDANCE INSISTS THAT THE RIDGING WILL
WIN OUT WHILE THE HRRR DEVELOPS THE ISOLATED TO WIDELY SCATTERED
STORMS LATER THIS MORNING AND THIS AFTERNOON. WE SHALL SEE. 42
PREV DISCUSSION... /ISSUED 629 AM CDT THU JUN 19 2014/
DISCUSSION...
12Z TAF DISCUSSION IN AVIATION SECTION.
AVIATION...
OVERALL JUST A SMATTERING OF MVFR CIGS OVER KUTS/KCXO BUT
OTHERWISE MOST TERMINALS STILL IN THE VFR FLIGHT CATEGORY. MAY SEE
SOME MVFR CIGS DEVELOP 14-16Z BUT REALLY NOT ENOUGH CONFIDENCE FOR
A TEMPO GROUP. SHRA ACTIVITY LOOKS TO BE MINIMAL AT THE MOMENT
WITH MAYBE SOMETHING FOR LBX/GLS OFF THE GULF. RAPID REFRESH MODEL
AND WRF SUPPORT AT LEAST SOME SHRA DURING THE 17-21Z TIME FRAME
BUT HARD TO PINPOINT WHERE EXACTLY. INTEND TO HANDLE ANY
CONVECTION WITH AMMENDMENTS SHOULD ANYTHING IMPACT TERMINALS. LOOK
FOR SIMILAR CONDITIONS TONIGHT INTO THUR MORNING BUT EXPECT WINDS
TO BE WEAKER.
39
PREV DISCUSSION... /ISSUED 443 AM CDT THU JUN 19 2014/
DISCUSSION...
AN ANALYSIS OF THE 00Z UPPER AIR SURFACES REVEALED A SOUTH-TO-
NORTH 200 AND 300 MB RIDGE OVER SE TX...AND A WEAK 500 MB HIGH
PRESSURE RIDGE EXTENDING FROM NC TO THE UPPER TX COAST. THERE WAS
A SOUTHERLY FLOW IN PLACE FROM THE SURFACE TO 700 MB DUE TO THE
HIGH PRESSURE RIDGE EXTENDING INTO THE AREA FROM THE CAROLINAS.
THE FORECAST MODELS BUILD THE 500 MB RIDGE OVER SE TX THROUGH THE
END OF THE WEEK BEFORE THEN DIGGING A WEAK UPPER LEVEL TROUGH
OVERHEAD EARLY NEXT WEEK.
THE MODEL OUTPUT AND GUIDANCE BOTH FORECAST LESS CHANCES FOR RAIN
TODAY THAN WHAT OCCURRED YESTERDAY. THE FORECAST SOUNDINGS DEVELOP
LESS CAPE AND LOWER PW/S...WITH THE HIGH RESOLUTION HRRR AND TEXAS
TECH MODELS REFLECTING THIS BY FORECASTING ONLY ISOLATED SHOWERS
THROUGHOUT THE DAY. GIVEN THE WEAK FLOW ALOFT...THE SEA BREEZE MAY
FIGURE MORE PROMINENTLY. BECAUSE OF THIS...WILL GO WITH 10 PERCENT
CHANCES NEAR THE COAST THIS MORNING AND 20 PERCENT INLAND THIS
AFTERNOON AND EARLY EVENING. THE SAME SCENARIO LOOKS TO OCCUR ON
FRIDAY...ALBEIT WITH ONLY 10 PERCENT CHANCES FOR RAIN DURING THE
AFTERNOON OVER THE INLAND AREAS.
WITH THE BUILDING MID LEVEL RIDGE OVERHEAD...BOTH SATURDAY AND
SUNDAY WILL BE DRY WITH SLIGHTLY WARMER DAYTIME TEMPERATURES. THE
GFS AND ECWMF FORECAST A WEAK EASTERLY WAVE TO MOVE AROUND THE
SUBTROPICAL RIDGE. THIS FEATURE MAY WORK ITS WAY TOWARD THE UPPER
TX COAST AND PROVIDE A MORE MOIST AIRMASS BY THE MIDDLE OF NEXT
WEEK. BOTH MODELS ALSO DEVELOP AN UPPER TROUGH OVER SE TX DURING
THE EARLY AND MID WEEK PERIOD. BECAUSE OF THE UNCERTAINTY WITH
TIMING...WILL GO WITH ISOLATED RAIN CHANCES FOR MONDAY THROUGH
WEDNESDAY.
MARINE...
A SMALL CRAFT EXERCISE CAUTION WILL CONTINUE THIS MORNING WITH
WINDS DECREASING LATER IN THE MORNING. THIS WILL KEEP SEAS
ELEVATED IN OFFSHORE AREAS. HIGH PRESSURE BEGINS TO MOVE CLOSER TO
THE AREA WHICH WILL ALLOW THE PRESSURE GRADIENT TO RELAX ALONG
WITH THE SURFACE WINDS. LIGHT TO OCCASIONALLY MODERATE WINDS WITH
2 TO 4 FOOT SEAS WILL CONTINUE THROUGH THE WEEKEND.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 74 93 74 94 74 / 10 10 10 10 10
HOUSTON (IAH) 75 92 75 94 75 / 10 10 10 10 10
GALVESTON (GLS) 80 89 80 88 80 / 10 10 10 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...23
AVIATION/MARINE...23
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1040 AM CDT THU JUN 19 2014
.DISCUSSION...
FOR THE MORNING UPDATE...WENT AHEAD AND JUST GAVE THE AREA A SLIGHT
CHANCE OF SHOWERS AND THUNDERSTORMS FOR TODAY. AS TEMPERATURES WARM
INTO THE 90S THIS AFTERNOON...ANTICIPATE SEEING THE DEVELOPMENT OF
SOME STORMS. PIECES OF ENERGY EJECTING OUT FROM THE NEARLY STATIONARY
MID/UPPER LOW TO OUR SOUTHWEST NEAR THE TEXAS-MEXICO BORDER MIGHT
BE ENOUGH TO GENERATE TODAY`S ACTIVITY AS WEAK MID/UPPER LEVEL RIDGING
TRIES TO BUILD INTO OUR AREA FROM THE EAST AND NORTHEAST AND SHUT
THINGS DOWN. THE 12Z NAM MOS GUIDANCE INSISTS THAT THE RIDGING WILL
WIN OUT WHILE THE HRRR DEVELOPS THE ISOLATED TO WIDELY SCATTERED
STORMS LATER THIS MORNING AND THIS AFTERNOON. WE SHALL SEE. 42
&&
.PREV DISCUSSION... /ISSUED 629 AM CDT THU JUN 19 2014/
DISCUSSION...
12Z TAF DISCUSSION IN AVIATION SECTION.
AVIATION...
OVERALL JUST A SMATTERING OF MVFR CIGS OVER KUTS/KCXO BUT
OTHERWISE MOST TERMINALS STILL IN THE VFR FLIGHT CATEGORY. MAY SEE
SOME MVFR CIGS DEVELOP 14-16Z BUT REALLY NOT ENOUGH CONFIDENCE FOR
A TEMPO GROUP. SHRA ACTIVITY LOOKS TO BE MINIMAL AT THE MOMENT
WITH MAYBE SOMETHING FOR LBX/GLS OFF THE GULF. RAPID REFRESH MODEL
AND WRF SUPPORT AT LEAST SOME SHRA DURING THE 17-21Z TIME FRAME
BUT HARD TO PINPOINT WHERE EXACTLY. INTEND TO HANDLE ANY
CONVECTION WITH AMMENDMENTS SHOULD ANYTHING IMPACT TERMINALS. LOOK
FOR SIMILAR CONDITIONS TONIGHT INTO THUR MORNING BUT EXPECT WINDS
TO BE WEAKER.
39
PREV DISCUSSION... /ISSUED 443 AM CDT THU JUN 19 2014/
DISCUSSION...
AN ANALYSIS OF THE 00Z UPPER AIR SURFACES REVEALED A SOUTH-TO-
NORTH 200 AND 300 MB RIDGE OVER SE TX...AND A WEAK 500 MB HIGH
PRESSURE RIDGE EXTENDING FROM NC TO THE UPPER TX COAST. THERE WAS
A SOUTHERLY FLOW IN PLACE FROM THE SURFACE TO 700 MB DUE TO THE
HIGH PRESSURE RIDGE EXTENDING INTO THE AREA FROM THE CAROLINAS.
THE FORECAST MODELS BUILD THE 500 MB RIDGE OVER SE TX THROUGH THE
END OF THE WEEK BEFORE THEN DIGGING A WEAK UPPER LEVEL TROUGH
OVERHEAD EARLY NEXT WEEK.
THE MODEL OUTPUT AND GUIDANCE BOTH FORECAST LESS CHANCES FOR RAIN
TODAY THAN WHAT OCCURRED YESTERDAY. THE FORECAST SOUNDINGS DEVELOP
LESS CAPE AND LOWER PW/S...WITH THE HIGH RESOLUTION HRRR AND TEXAS
TECH MODELS REFLECTING THIS BY FORECASTING ONLY ISOLATED SHOWERS
THROUGHOUT THE DAY. GIVEN THE WEAK FLOW ALOFT...THE SEA BREEZE MAY
FIGURE MORE PROMINENTLY. BECAUSE OF THIS...WILL GO WITH 10 PERCENT
CHANCES NEAR THE COAST THIS MORNING AND 20 PERCENT INLAND THIS
AFTERNOON AND EARLY EVENING. THE SAME SCENARIO LOOKS TO OCCUR ON
FRIDAY...ALBEIT WITH ONLY 10 PERCENT CHANCES FOR RAIN DURING THE
AFTERNOON OVER THE INLAND AREAS.
WITH THE BUILDING MID LEVEL RIDGE OVERHEAD...BOTH SATURDAY AND
SUNDAY WILL BE DRY WITH SLIGHTLY WARMER DAYTIME TEMPERATURES. THE
GFS AND ECWMF FORECAST A WEAK EASTERLY WAVE TO MOVE AROUND THE
SUBTROPICAL RIDGE. THIS FEATURE MAY WORK ITS WAY TOWARD THE UPPER
TX COAST AND PROVIDE A MORE MOIST AIRMASS BY THE MIDDLE OF NEXT
WEEK. BOTH MODELS ALSO DEVELOP AN UPPER TROUGH OVER SE TX DURING
THE EARLY AND MID WEEK PERIOD. BECAUSE OF THE UNCERTAINTY WITH
TIMING...WILL GO WITH ISOLATED RAIN CHANCES FOR MONDAY THROUGH
WEDNESDAY.
MARINE...
A SMALL CRAFT EXERCISE CAUTION WILL CONTINUE THIS MORNING WITH
WINDS DECREASING LATER IN THE MORNING. THIS WILL KEEP SEAS
ELEVATED IN OFFSHORE AREAS. HIGH PRESSURE BEGINS TO MOVE CLOSER TO
THE AREA WHICH WILL ALLOW THE PRESSURE GRADIENT TO RELAX ALONG
WITH THE SURFACE WINDS. LIGHT TO OCCASIONALLY MODERATE WINDS WITH
2 TO 4 FOOT SEAS WILL CONTINUE THROUGH THE WEEKEND.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 92 74 93 74 94 / 20 10 10 10 10
HOUSTON (IAH) 91 75 92 75 94 / 20 10 10 10 10
GALVESTON (GLS) 88 80 89 80 88 / 20 10 10 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...42
AVIATION/MARINE...23
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
629 AM CDT THU JUN 19 2014
.DISCUSSION...
12Z TAF DISCUSSION IN AVIATION SECTION.
&&
.AVIATION...
OVERALL JUST A SMATTERING OF MVFR CIGS OVER KUTS/KCXO BUT
OTHERWISE MOST TERMINALS STILL IN THE VFR FLIGHT CATEGORY. MAY SEE
SOME MVFR CIGS DEVELOP 14-16Z BUT REALLY NOT ENOUGH CONFIDENCE FOR
A TEMPO GROUP. SHRA ACTIVITY LOOKS TO BE MINIMAL AT THE MOMENT
WITH MAYBE SOMETHING FOR LBX/GLS OFF THE GULF. RAPID REFRESH MODEL
AND WRF SUPPORT AT LEAST SOME SHRA DURING THE 17-21Z TIME FRAME
BUT HARD TO PINPOINT WHERE EXACTLY. INTEND TO HANDLE ANY
CONVECTION WITH AMMENDMENTS SHOULD ANYTHING IMPACT TERMINALS. LOOK
FOR SIMILAR CONDITIONS TONIGHT INTO THUR MORNING BUT EXPECT WINDS
TO BE WEAKER.
39
&&
.PREV DISCUSSION... /ISSUED 443 AM CDT THU JUN 19 2014/
DISCUSSION...
AN ANALYSIS OF THE 00Z UPPER AIR SURFACES REVEALED A SOUTH-TO-
NORTH 200 AND 300 MB RIDGE OVER SE TX...AND A WEAK 500 MB HIGH
PRESSURE RIDGE EXTENDING FROM NC TO THE UPPER TX COAST. THERE WAS
A SOUTHERLY FLOW IN PLACE FROM THE SURFACE TO 700 MB DUE TO THE
HIGH PRESSURE RIDGE EXTENDING INTO THE AREA FROM THE CAROLINAS.
THE FORECAST MODELS BUILD THE 500 MB RIDGE OVER SE TX THROUGH THE
END OF THE WEEK BEFORE THEN DIGGING A WEAK UPPER LEVEL TROUGH
OVERHEAD EARLY NEXT WEEK.
THE MODEL OUTPUT AND GUIDANCE BOTH FORECAST LESS CHANCES FOR RAIN
TODAY THAN WHAT OCCURRED YESTERDAY. THE FORECAST SOUNDINGS DEVELOP
LESS CAPE AND LOWER PW/S...WITH THE HIGH RESOLUTION HRRR AND TEXAS
TECH MODELS REFLECTING THIS BY FORECASTING ONLY ISOLATED SHOWERS
THROUGHOUT THE DAY. GIVEN THE WEAK FLOW ALOFT...THE SEA BREEZE MAY
FIGURE MORE PROMINENTLY. BECAUSE OF THIS...WILL GO WITH 10 PERCENT
CHANCES NEAR THE COAST THIS MORNING AND 20 PERCENT INLAND THIS
AFTERNOON AND EARLY EVENING. THE SAME SCENARIO LOOKS TO OCCUR ON
FRIDAY...ALBEIT WITH ONLY 10 PERCENT CHANCES FOR RAIN DURING THE
AFTERNOON OVER THE INLAND AREAS.
WITH THE BUILDING MID LEVEL RIDGE OVERHEAD...BOTH SATURDAY AND
SUNDAY WILL BE DRY WITH SLIGHTLY WARMER DAYTIME TEMPERATURES. THE
GFS AND ECWMF FORECAST A WEAK EASTERLY WAVE TO MOVE AROUND THE
SUBTROPICAL RIDGE. THIS FEATURE MAY WORK ITS WAY TOWARD THE UPPER
TX COAST AND PROVIDE A MORE MOIST AIRMASS BY THE MIDDLE OF NEXT
WEEK. BOTH MODELS ALSO DEVELOP AN UPPER TROUGH OVER SE TX DURING
THE EARLY AND MID WEEK PERIOD. BECAUSE OF THE UNCERTAINTY WITH
TIMING...WILL GO WITH ISOLATED RAIN CHANCES FOR MONDAY THROUGH
WEDNESDAY.
40
AVIATION...
WINDS OFF THE COAST ARE STILL STRONG ENOUGH THAT THERE COULD BE
ENOUGH SPEED CONVERGENCE LATER IN THE MORNING TO SUPPORT A FEW
SHOWERS. OVERALL LOOKING AT VFR CIGS WITH MAY BE A COUPLE HRS OF
MVFR IN THE MORNING HRS. CEILINGS SHOULD THEN LIFT FOR THE
AFTERNOON WITH WINDS AROUND 10-15KTS FROM THE SE. LOOK FOR THE
SAME CONDITIONS TO OCCUR TONIGHT INTO THUR BUT WINDS MAY BE A
LITTLE LESS.
39
MARINE...
A SMALL CRAFT EXERCISE CAUTION WILL CONTINUE THIS MORNING WITH
WINDS DECREASING LATER IN THE MORNING. THIS WILL KEEP SEAS
ELEVATED IN OFFSHORE AREAS. HIGH PRESSURE BEGINS TO MOVE CLOSER TO
THE AREA WHICH WILL ALLOW THE PRESSURE GRADIENT TO RELAX ALONG
WITH THE SURFACE WINDS. LIGHT TO OCCASIONALLY MODERATE WINDS WITH
2 TO 4 FOOT SEAS WILL CONTINUE THROUGH THE WEEKEND.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 92 74 93 74 94 / 20 10 10 10 10
HOUSTON (IAH) 91 75 92 75 94 / 20 10 10 10 10
GALVESTON (GLS) 88 80 89 80 88 / 10 10 10 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 10 AM CDT THIS MORNING
FOR THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY...
WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO
60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL
OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60
NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...40
AVIATION/MARINE...39
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
443 AM CDT THU JUN 19 2014
.DISCUSSION...
AN ANALYSIS OF THE 00Z UPPER AIR SURFACES REVEALED A SOUTH-TO-
NORTH 200 AND 300 MB RIDGE OVER SE TX...AND A WEAK 500 MB HIGH
PRESSURE RIDGE EXTENDING FROM NC TO THE UPPER TX COAST. THERE WAS
A SOUTHERLY FLOW IN PLACE FROM THE SURFACE TO 700 MB DUE TO THE
HIGH PRESSURE RIDGE EXTENDING INTO THE AREA FROM THE CAROLINAS.
THE FORECAST MODELS BUILD THE 500 MB RIDGE OVER SE TX THROUGH THE
END OF THE WEEK BEFORE THEN DIGGING A WEAK UPPER LEVEL TROUGH
OVERHEAD EARLY NEXT WEEK.
THE MODEL OUTPUT AND GUIDANCE BOTH FORECAST LESS CHANCES FOR RAIN
TODAY THAN WHAT OCCURRED YESTERDAY. THE FORECAST SOUNDINGS DEVELOP
LESS CAPE AND LOWER PW/S...WITH THE HIGH RESOLUTION HRRR AND TEXAS
TECH MODELS REFLECTING THIS BY FORECASTING ONLY ISOLATED SHOWERS
THROUGHOUT THE DAY. GIVEN THE WEAK FLOW ALOFT...THE SEA BREEZE MAY
FIGURE MORE PROMINENTLY. BECAUSE OF THIS...WILL GO WITH 10 PERCENT
CHANCES NEAR THE COAST THIS MORNING AND 20 PERCENT INLAND THIS
AFTERNOON AND EARLY EVENING. THE SAME SCENARIO LOOKS TO OCCUR ON
FRIDAY...ALBEIT WITH ONLY 10 PERCENT CHANCES FOR RAIN DURING THE
AFTERNOON OVER THE INLAND AREAS.
WITH THE BUILDING MID LEVEL RIDGE OVERHEAD...BOTH SATURDAY AND
SUNDAY WILL BE DRY WITH SLIGHTLY WARMER DAYTIME TEMPERATURES. THE
GFS AND ECWMF FORECAST A WEAK EASTERLY WAVE TO MOVE AROUND THE
SUBTROPICAL RIDGE. THIS FEATURE MAY WORK ITS WAY TOWARD THE UPPER
TX COAST AND PROVIDE A MORE MOIST AIRMASS BY THE MIDDLE OF NEXT
WEEK. BOTH MODELS ALSO DEVELOP AN UPPER TROUGH OVER SE TX DURING
THE EARLY AND MID WEEK PERIOD. BECAUSE OF THE UNCERTAINTY WITH
TIMING...WILL GO WITH ISOLATED RAIN CHANCES FOR MONDAY THROUGH
WEDNESDAY.
40
&&
.AVIATION...
WINDS OFF THE COAST ARE STILL STRONG ENOUGH THAT THERE COULD BE
ENOUGH SPEED CONVERGENCE LATER IN THE MORNING TO SUPPORT A FEW
SHOWERS. OVERALL LOOKING AT VFR CIGS WITH MAY BE A COUPLE HRS OF
MVFR IN THE MORNING HRS. CEILINGS SHOULD THEN LIFT FOR THE
AFTERNOON WITH WINDS AROUND 10-15KTS FROM THE SE. LOOK FOR THE
SAME CONDITIONS TO OCCUR TONIGHT INTO THUR BUT WINDS MAY BE A
LITTLE LESS.
39
&&
.MARINE...
A SMALL CRAFT EXERCISE CAUTION WILL CONTINUE THIS MORNING WITH
WINDS DECREASING LATER IN THE MORNING. THIS WILL KEEP SEAS
ELEVATED IN OFFSHORE AREAS. HIGH PRESSURE BEGINS TO MOVE CLOSER TO
THE AREA WHICH WILL ALLOW THE PRESSURE GRADIENT TO RELAX ALONG
WITH THE SURFACE WINDS. LIGHT TO OCCASIONALLY MODERATE WINDS WITH
2 TO 4 FOOT SEAS WILL CONTINUE THROUGH THE WEEKEND.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 92 74 93 74 94 / 20 10 10 10 10
HOUSTON (IAH) 91 75 92 75 94 / 20 10 10 10 10
GALVESTON (GLS) 88 80 89 80 88 / 10 10 10 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 10 AM CDT THIS MORNING
FOR THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY...
WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO
60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL
OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60
NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...40
AVIATION/MARINE...39
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
136 PM EDT THU JUN 19 2014
.SYNOPSIS...
A WEAK COLD FRONT ACROSS THE OHIO VALLEY WILL DRIFT SOUTH TOWARD
THE AREA THIS AFTERNOON BEFORE STALLING ACROSS THE MID ATLANTIC
REGION TONIGHT. UPPER DISTURBANCES RIDING ALONG THE FRONT WILL
RESULT IN PERIODS OF SHOWERS AND STORMS AS THE BOUNDARY MEANDERS
OVER THE AREA THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 945 AM EDT THURSDAY...
INITIAL BAND OF BROKEN EARLIER CONVECTION HAS FADED UPON
ENCOUNTERING A BIT MORE STABLE AIR TO THE SE OF THE WESTERN SLOPES
THIS MORNING. HOWEVER OUTFLOW ASSOCIATED WITH THIS EARLIER
CONVECTION AND ADDITIONAL UPSTREAM CLUSTERS WILL LIKELY CAUSE AN
UPTICK IN COVERAGE OVER THE NORTH/NW BY EARLY AFTERNOON. FLOW
REMAINS DEEP WESTERLY PER MORNING SOUNDINGS SO STILL LIKELY
ENOUGH INTIALLY TO LIMIT EASTWARD ADVANCE ACROSS THE RIDGES. MUCH
STRONGER SHORTWAVE SOUTH OF LAKE ERIE LOOKS TO BE THE MAIN PLAYER
LATER ON AS MODELS SPILL IT SE WITH SOME INTERSECTION WITH THE
PIEDMONT LEE TROF LATE. MOST OF THIS COVERAGE LIKELY TO RUN AROUND
THE EASTERN DOWNSLOPE WITH A BAND OF STORMS POSSIBLY UNZIPPING
BACK WEST ACROSS THE CENTRAL CWA...AND PUSHING SOUTH BY LATE
AFTERNOON UNDER THE VORT TAIL/OUTFLOW. THIS SUPPORTED BY MODIFIED
CAPES PUSHING 3K J/KG AGAIN ESPCLY EAST AND A GRADUAL INCREASE IN
LIFT AS BETTER DYNAMICS ARRIVE. THUS WILL BE RUNNING WITH LOW
LIKELYS FOR INIT COVERAGE NW...THEN HIGHER CHANCE POPS EAST PER
SHORTWAVE...AND ACROSS THE SOUTH/WEST LATE WHERE THINGS LIKELY
BAND UP A BIT MORE. HAVE LESS POP TODAY IN THE LEE OF THE BLUE
RIDGE IN LIGHT OF A RATHER WELL MIXED WEST WIND INITIALLY AND IN
LINE WITH THE LATEST HRRR AND RAP WHICH MAINTAIN A HOLE IN
COVERAGE CENTRAL SECTIONS UNITL LATE.
HIGHS APPEAR ON TRACK WITH 90-95 EAST GIVEN DOWNSLOPE AND MORE SUN BUT
LIKELY COOLER NW WHERE EARLY CLOUDS/TSRA MAY HOLD HOLD VALUES DOWN
A FEW DEGREES.
PREVIOUS DISCUSSION AS OF 330 AM EDT THURSDAY...
SHORT WAVE OVER THE NORTHERN OHIO VALLEY CROSSES INTO EASTERN
VIRGINIA BY THIS EVENING. FLOW 500 MB CHANGES FROM LIGHT WESTERLY
WITH THE UPPER RIDGE TO NORTHWEST AROUND THE DIGGING UPPER LOW IN
SOUTHEAST CANADA.
BEST Q-V FORCING STAYS JUST TO THE NORTH AND EAST OF THE FORECAST
AREA THIS AFTERNOON AND EVENING BUT SHORT WAVE WILL STILL RESULT IN
MORE EXTENSIVE AREAL COVERAGE AND MORE ORGANIZED STORMS COMPARED
WITH THE ISOLATED PULSE CONVECTION OF TUESDAY AND WEDNESDAY.
AT 2AM OUTFLOW BOUNDARY EXTENDED FROM THE MARYLAND PANHANDLE INTO
CENTRAL WEST VIRGINIA. ISOLATED TO SCATTERED SHOWERS ARE EXPECTED
ALONG THIS BOUNDARY THIS MORNING. WILL HAVE HIGHER PROBABILITY OF
PRECIPITATION IN THE FAR WESTERN COUNTY WARNING AREA EARLY THIS
MORNING. THE LOCATION OF THE OUTFLOW BOUNDARY AT THE TIME OF PEAK
HEATING THIS AFTERNOON WILL GREATLY INFLUENCE WHERE THE HIGHEST
CHANCE OF THUNDERSTORMS WILL BE. CLOUDS FROM THE SHOWERS AND
THUNDERSTORMS THIS MORNING WILL ALSO LIMIT HEATING IN THE WEST. WILL
HAVE HIGHEST PROBABILITY OF THUNDERSTORMS EAST OF THE BLUE RIDGE
THIS AFTERNOON AND EVENING. PRE-STORM ENVIRONMENT REMAINS HIGH
CAPE/LOW SHEAR THROUGH THE EVENING.
SURFACE FRONT AS SEEN IN LIFTED INDEX FORECAST AND PUSHES LEADING
EDGE OF DRIER AIR AND MORE STABLE AIR IN FROM THE NORTH...REACHING
THE NORTHEAST COUNTY WARNING AREA BY LATE TONIGHT. SHIFT TO DEEPER
NORTHWEST FLOW ALOFT WILL AIDE IN CHANGE OF AIR MASS IN THE PIEDMONT
AND COAST PLAIN BUT SKEPTICAL THAT SURFACE BOUNDARY WILL BE AS FAR
SOUTH AS THE MODELS DEPICT BY FRIDAY MORNING.
STARTING OUT WITH MORE CLOUDS...ESPECIALLY IN WEST THIS MORNING.
THIS WILL HOLD BACK ON HEATING AND MAXIMUM TEMPERATURES. CLOUDS AND
PRECIPITATION WILL KEEP TEMPERATURES MILD OVERNIGHT.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/...
AS OF 350 AM EDT THURSDAY...
UPPER TROF PUSHES EAST INTO THE ATLANTIC OCEAN INTO THE WEEKEND...AS
THE RIDGE AXIS DEAMPLIFYS OR FLATTENS ACROSS THE WESTERN GREAT LAKES
AND LOWER OHIO VALLEY. ON FRIDAY...THE BACK DOOR COLD FRONT WILL BE
SLOWLY TRAVELING SOUTH ACROSS OUR FORECAST AREA. EASTERN PORTIONS OF
THE FRONTAL BOUNDARY PROGGED TO MOVE INTO NORTH CAROLINA. PLACEMENT
OF THE BOUNDARY IS PROBLEMATIC WITH LIGHT WIND FIELDS AND
CONCERNS THAT THIS BOUNDARY WILL NOT TRAVEL THAT FAR SOUTH
ESPECIALLY WITH THE 85H THETA-E BOUNDARY REMAIN WELL TO THE NORTH
OF THE FORECAST AREA. KEPT THE HIGHEST POPS FOR CONVECTION IN THE
NORTHWEST WITH LIGHTEST IN THE SOUTHEAST. WONDERING IF EASTERLY
FLOW ALONG THE BLUE RIDGE EASTERN SLOPES WILL RESULT IN MORE
SHOWERS AND LIMITED INSTABILITIES. BELIEVE THAT MODEST
INSTABILITIES OVER THE MOUNTAINS SHOULD GENERATE AFTERNOON
THUNDERSTORMS FRIDAY IN THE WEST. WILL ALSO NEED TO KEEP AN EYE ON
THE OHIO VALLEY LATE FRIDAY AFTERNOON INTO THE OVERNIGHT HOURS AS
A POSSIBLE MESOSCALE COMPLEX COULD TRACK NEAR THE AREA WITH 5H
ISOHEIGHTS ORIENTED NW-SE. ANY CONVECTIVE COMPLEX THAT DEVELOPS
SHOULD TRACK CLOSE TO THE 85H THETA-E BOUNDARY WHICH IS NORTH OF
THE AREA. IN ANY CASE...SCATTERED POSSIBLY STRONG CONVECTION COULD
LINGER THROUGH FRIDAY NIGHT INTO SATURDAY. BOTH GFS AND ECMWF
GENERATE WIDESPREAD CONVECTION SATURDAY WITH DISTURBANCE TRACKING
SOUTHEAST TO THE CAROLINA SHORE.
PLAYED TEMPERATURES ABOVE NORMAL FOR FRIDAY WITH READINGS FROM
AROUND 80 DEGREES IN THE MOUNTAINS TO AROUND 90 DEGREES IN THE
SOUTHEAST. LOW TEMPERATURES FRIDAY NIGHT WILL REMAIN QUITE MILD WITH
VALUES FROM THE LOWER 60S IN THE WEST TO AROUND 70 DEGREES IN THE
EAST. HIGH TEMPERATURES WILL BE SLIGHTLY COOLER ON SATURDAY FROM
THE UPPER 70S TO NEAR 90 IN THE PIEDMONT. WENT WITH LOW TEMPERATURES
SATURDAY NIGHT CLOSE TO ENSEMBLE GFS MOS GENERALLY IN THE 60S.
FRONTAL BOUNDARY EXPECTED TO CONTINUE TO PUSH SOUTH ON SUNDAY INTO
SOUTH CAROLINA. THE GFS DEVELOPS A SFC LOW PRESSURE CENTER OFF THE
SOUTH CAROLINA COAST...WHILE ECMWF DOES NOT HAVE THIS FEATURE.
SCATTERED SHOWERS AND THUNDERSTORMS EXPECTED SUNDAY AFTERNOON INTO
SUNDAY NIGHT. DECREASED HIGH TEMPERATURES FOR SUNDAY WITH VALUES
FROM THE UPPER 70S IN THE MOUNTAINS TO THE MID 80S IN THE PIEDMONT.
&&
.LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 300 PM EDT WEDNESDAY...
UPPER LEVEL FLOW BECOMES ZONAL EARLY NEXT WEEK. THE LOWER BOUNDARY
LAYER FLOW WILL RETURN TO THE SOUTH ALLOWING PULSE STORMS TO
DEVELOP. THIS PATTERN OF AFTERNOON AND EVENING THUNDERSTORMS WILL
PERSIST THROUGH WEDNESDAY AND POSSIBLY INTO THE END OF THE WEEK.
LOOKING BEYOND THE EXTENDED...A COLD FRONT MAY CLEAR THINGS OUT BY
NEXT WEEKEND. TEMPERATURES WILL REMAIN WARM AND MUGGY UNTIL THIS
COLD FRONT PASSES EAST OF THE AREA.
&&
.AVIATION /17Z THURSDAY THROUGH MONDAY/...
AS OF 115 PM EDT THURSDAY...
CLUSTERS OF DEEP CONVECTION CONTINUE TO DEVELOP AND SPILL EAST
ALONG THE KLWB-KLYH CORRIDOR EARLY THIS AFTERNOON WITH ADDED
DEVELOPMENT ONGOING DOWN THE WESTERN SLOPES TO THE WEST OF KMKJ.
EXPECT THIS TO KEEP PERIODS OF MVFR AT KLWB OVER THE NEXT HOUR OR
TWO WITH PERHAPS BRIEF IFR IF A HEAVIER TSRA CROSSES DIRECTLY OVER
THE AIRPORT. SHOULD SEE MOST OF THIS COVERAGE SHIFT SE OF KLWB BY
20Z/4PM. THEN EXPECT STORMS TO FILL IN OUT EAST WITH ONLY WIDELY
SCATTERED CONVECTION LIKELY AROUND KBLF WITH SOME OF THIS
SPREADING EAST TO NEAR KBCB/KROA BEFORE WEAKENING GIVEN THE STRONG
WEST WINDS ATTM. TSRA MAY TEND TO JUMP THE BLUE RIDGE LATER THIS
AFTERNOON WITH INCREASING CHANCES OVER THE PIEDMONT ESPCLY AROUND
KDAN ONCE THE DOWNSLOPE WEAKENS A BIT LATER ON. THUS HAVE
CONTINUED THE TREND OF INCLUDING A PREVAILING PERIOD OF MVFR IN
SHRA/TSRA WHERE ALREADY ONGOING OR APPROACHING AND VCTS ELSW UNTIL
LATE IN THE DAY.
A BACKDOOR FRONT DIPS SOUTH TOWARD THE AREA FROM THE MASON-DIXON
LINE TONIGHT WHICH WILL INCREASE THE RANGE OF STORMS INTO MORE
SCATTERED AND MULTICELLULAR THIS EVENING ESPCLY SOUTHERN AND
WESTERN SECTIONS. MODELS ARE BRINGING MVFR TO IFR CLOUDS AND FOG
INTO THE FORECAST AREA NORTH OF THE FRONT LATE TONIGHT. BUFKIT
SOUNDINGS SHOWED DRIER AIR COMING IN AT MID AND HIGH LEVELS WHILE
THE NAM LOWERS MOST CIGS TO IFR/MVFR IN LOW LEVEL NE FLOW BY
MORNING. THINK THIS MAY BE OVERDONE GIVEN SLOWNESS OF THE BOUNDARY
BUT A PERIOD OF LOW CIGS POSSIBLE KLWB EAST TO ALONG THE BLUE
RIDGE BY DAYBREAK ON FRIDAY.
BEST LIFT AND MOISTURE LOOKS TO GET PUSHED INTO THE FAR SW
SECTIONS FRIDAY MORNING BEFORE ANOTHER WAVE STARTS TO SHIFT THE
DEEPER MOISTURE EAST DURING THE AFTERNOON. LATEST GUIDANCE
INDICATES THAT INSTABILITY MAY BE MUCH LESS INTO FRIDAY AFTERNOON
WITH ADDED CONVECTION LIKELY FAR WEST AND NOT INCREASING UNTIL THE
EAST. OTRW THE MAIN CONCERN FRIDAY WILL BE WITH HOW FAST
CONDITIONS TURN VFR AS IF MORE FOG/STRATUS DEVELOPS OVERNIGHT THEN
COULD BE LOCKED INTO AT LEAST MVFR OVER THE EAST UNTIL MIDDAY OR
SO.
EXTENDED AVIATION DISCUSSION...
THE FRONT AND DISTURBANCE ALOFT SHOULD PRODUCE BETTER COVERAGE
FRIDAY NIGHT. A WEAK FLOW PATTERN HOLDING OVER THE WEEKEND WILL
KEEP THE STORM CHANCES EACH AFTERNOON THROUGH EARLY EVENING
SAT/SUN BUT COVERAGE FOR NOW LOOKS A BIT LESS EACH DAY BEHIND THE
PASSING IMPULSE FROM FRIDAY NIGHT. DEEPER MOISTURE LOOKS TO RETURN
NORTH BY EARLY NEXT WEEK WITH BETTER COVERAGE OF AFTERNOON/EVENING
STORMS ON MONDAY.
AREAS OF IFR FOG REMAIN POSSIBLE EACH LATE NIGHT/EARLY MORNING...
PARTICULARLY IN AREAS THAT SEE RAIN THE PREVIOUS AFTERNOON. THE
MOST OPTIMAL FLIGHT CONDITIONS EACH DAY SHOULD BE IN THE MID TO
LATE MORNING AFTER FOG/LOW CLOUDS LIFT AND BURN OFF...AND BEFORE
AFTERNOON CONVECTION REDEVELOPS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS/JH
NEAR TERM...AMS/JH
SHORT TERM...KK
LONG TERM...RCS
AVIATION...AMS/JH/PM
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1008 AM EDT THU JUN 19 2014
.SYNOPSIS...
A WEAK COLD FRONT ACROSS THE OHIO VALLEY WILL DRIFT SOUTH TOWARD
THE AREA THIS AFTERNOON BEFORE STALLING ACROSS THE MID ATLANTIC
REGION TONIGHT. UPPER DISTURBANCES RIDING ALONG THE FRONT WILL
RESULT IN PERIODS OF SHOWERS AND STORMS AS THE BOUNDARY MEANDERS
OVER THE AREA THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 945 AM EDT THURSDAY...
INITIAL BAND OF BROKEN EARLIER CONVECTION HAS FADED UPON
ENCOUNTERING A BIT MORE STABLE AIR TO THE SE OF THE WESTERN SLOPES
THIS MORNING. HOWEVER OUTFLOW ASSOCIATED WITH THIS EARLIER
CONVECTION AND ADDITIONAL UPSTREAM CLUSTERS WILL LIKELY CAUSE AN
UPTICK IN COVERAGE OVER THE NORTH/NW BY EARLY AFTERNOON. FLOW
REMAINS DEEP WESTERLY PER MORNING SOUNDINGS SO STILL LIKELY
ENOUGH INTIALLY TO LIMIT EASTWARD ADVANCE ACROSS THE RIDGES. MUCH
STRONGER SHORTWAVE SOUTH OF LAKE ERIE LOOKS TO BE THE MAIN PLAYER
LATER ON AS MODELS SPILL IT SE WITH SOME INTERSECTION WITH THE
PIEDMONT LEE TROF LATE. MOST OF THIS COVERAGE LIKELY TO RUN AROUND
THE EASTERN DOWNSLOPE WITH A BAND OF STORMS POSSIBLY UNZIPPING
BACK WEST ACROSS THE CENTRAL CWA...AND PUSHING SOUTH BY LATE
AFTERNOON UNDER THE VORT TAIL/OUTFLOW. THIS SUPPORTED BY MODIFIED
CAPES PUSHING 3K J/KG AGAIN ESPCLY EAST AND A GRADUAL INCREASE IN
LIFT AS BETTER DYNAMICS ARRIVE. THUS WILL BE RUNNING WITH LOW
LIKELYS FOR INIT COVERAGE NW...THEN HIGHER CHANCE POPS EAST PER
SHORTWAVE...AND ACROSS THE SOUTH/WEST LATE WHERE THINGS LIKELY
BAND UP A BIT MORE. HAVE LESS POP TODAY IN THE LEE OF THE BLUE
RIDGE IN LIGHT OF A RATHER WELL MIXED WEST WIND INITIALLY AND IN
LINE WITH THE LATEST HRRR AND RAP WHICH MAINTAIN A HOLE IN
COVERAGE CENTRAL SECTIONS UNITL LATE.
HIGHS APPEAR ON TRACK WITH 90-95 EAST GIVEN DOWNSLOPE AND MORE SUN BUT
LIKELY COOLER NW WHERE EARLY CLOUDS/TSRA MAY HOLD HOLD VALUES DOWN
A FEW DEGREES.
PREVIOUS DISCUSSION AS OF 330 AM EDT THURSDAY...
SHORT WAVE OVER THE NORTHERN OHIO VALLEY CROSSES INTO EASTERN
VIRGINIA BY THIS EVENING. FLOW 500 MB CHANGES FROM LIGHT WESTERLY
WITH THE UPPER RIDGE TO NORTHWEST AROUND THE DIGGING UPPER LOW IN
SOUTHEAST CANADA.
BEST Q-V FORCING STAYS JUST TO THE NORTH AND EAST OF THE FORECAST
AREA THIS AFTERNOON AND EVENING BUT SHORT WAVE WILL STILL RESULT IN
MORE EXTENSIVE AREAL COVERAGE AND MORE ORGANIZED STORMS COMPARED
WITH THE ISOLATED PULSE CONVECTION OF TUESDAY AND WEDNESDAY.
AT 2AM OUTFLOW BOUNDARY EXTENDED FROM THE MARYLAND PANHANDLE INTO
CENTRAL WEST VIRGINIA. ISOLATED TO SCATTERED SHOWERS ARE EXPECTED
ALONG THIS BOUNDARY THIS MORNING. WILL HAVE HIGHER PROBABILITY OF
PRECIPITATION IN THE FAR WESTERN COUNTY WARNING AREA EARLY THIS
MORNING. THE LOCATION OF THE OUTFLOW BOUNDARY AT THE TIME OF PEAK
HEATING THIS AFTERNOON WILL GREATLY INFLUENCE WHERE THE HIGHEST
CHANCE OF THUNDERSTORMS WILL BE. CLOUDS FROM THE SHOWERS AND
THUNDERSTORMS THIS MORNING WILL ALSO LIMIT HEATING IN THE WEST. WILL
HAVE HIGHEST PROBABILITY OF THUNDERSTORMS EAST OF THE BLUE RIDGE
THIS AFTERNOON AND EVENING. PRE-STORM ENVIRONMENT REMAINS HIGH
CAPE/LOW SHEAR THROUGH THE EVENING.
SURFACE FRONT AS SEEN IN LIFTED INDEX FORECAST AND PUSHES LEADING
EDGE OF DRIER AIR AND MORE STABLE AIR IN FROM THE NORTH...REACHING
THE NORTHEAST COUNTY WARNING AREA BY LATE TONIGHT. SHIFT TO DEEPER
NORTHWEST FLOW ALOFT WILL AIDE IN CHANGE OF AIR MASS IN THE PIEDMONT
AND COAST PLAIN BUT SKEPTICAL THAT SURFACE BOUNDARY WILL BE AS FAR
SOUTH AS THE MODELS DEPICT BY FRIDAY MORNING.
STARTING OUT WITH MORE CLOUDS...ESPECIALLY IN WEST THIS MORNING.
THIS WILL HOLD BACK ON HEATING AND MAXIMUM TEMPERATURES. CLOUDS AND
PRECIPITATION WILL KEEP TEMPERATURES MILD OVERNIGHT.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/...
AS OF 350 AM EDT THURSDAY...
UPPER TROF PUSHES EAST INTO THE ATLANTIC OCEAN INTO THE WEEKEND...AS
THE RIDGE AXIS DEAMPLIFYS OR FLATTENS ACROSS THE WESTERN GREAT LAKES
AND LOWER OHIO VALLEY. ON FRIDAY...THE BACK DOOR COLD FRONT WILL BE
SLOWLY TRAVELING SOUTH ACROSS OUR FORECAST AREA. EASTERN PORTIONS OF
THE FRONTAL BOUNDARY PROGGED TO MOVE INTO NORTH CAROLINA. PLACEMENT
OF THE BOUNDARY IS PROBLEMATIC WITH LIGHT WIND FIELDS AND
CONCERNS THAT THIS BOUNDARY WILL NOT TRAVEL THAT FAR SOUTH
ESPECIALLY WITH THE 85H THETA-E BOUNDARY REMAIN WELL TO THE NORTH
OF THE FORECAST AREA. KEPT THE HIGHEST POPS FOR CONVECTION IN THE
NORTHWEST WITH LIGHTEST IN THE SOUTHEAST. WONDERING IF EASTERLY
FLOW ALONG THE BLUE RIDGE EASTERN SLOPES WILL RESULT IN MORE
SHOWERS AND LIMITED INSTABILITIES. BELIEVE THAT MODEST
INSTABILITIES OVER THE MOUNTAINS SHOULD GENERATE AFTERNOON
THUNDERSTORMS FRIDAY IN THE WEST. WILL ALSO NEED TO KEEP AN EYE ON
THE OHIO VALLEY LATE FRIDAY AFTERNOON INTO THE OVERNIGHT HOURS AS
A POSSIBLE MESOSCALE COMPLEX COULD TRACK NEAR THE AREA WITH 5H
ISOHEIGHTS ORIENTED NW-SE. ANY CONVECTIVE COMPLEX THAT DEVELOPS
SHOULD TRACK CLOSE TO THE 85H THETA-E BOUNDARY WHICH IS NORTH OF
THE AREA. IN ANY CASE...SCATTERED POSSIBLY STRONG CONVECTION COULD
LINGER THROUGH FRIDAY NIGHT INTO SATURDAY. BOTH GFS AND ECMWF
GENERATE WIDESPREAD CONVECTION SATURDAY WITH DISTURBANCE TRACKING
SOUTHEAST TO THE CAROLINA SHORE.
PLAYED TEMPERATURES ABOVE NORMAL FOR FRIDAY WITH READINGS FROM
AROUND 80 DEGREES IN THE MOUNTAINS TO AROUND 90 DEGREES IN THE
SOUTHEAST. LOW TEMPERATURES FRIDAY NIGHT WILL REMAIN QUITE MILD WITH
VALUES FROM THE LOWER 60S IN THE WEST TO AROUND 70 DEGREES IN THE
EAST. HIGH TEMPERATURES WILL BE SLIGHTLY COOLER ON SATURDAY FROM
THE UPPER 70S TO NEAR 90 IN THE PIEDMONT. WENT WITH LOW TEMPERATURES
SATURDAY NIGHT CLOSE TO ENSEMBLE GFS MOS GENERALLY IN THE 60S.
FRONTAL BOUNDARY EXPECTED TO CONTINUE TO PUSH SOUTH ON SUNDAY INTO
SOUTH CAROLINA. THE GFS DEVELOPS A SFC LOW PRESSURE CENTER OFF THE
SOUTH CAROLINA COAST...WHILE ECMWF DOES NOT HAVE THIS FEATURE.
SCATTERED SHOWERS AND THUNDERSTORMS EXPECTED SUNDAY AFTERNOON INTO
SUNDAY NIGHT. DECREASED HIGH TEMPERATURES FOR SUNDAY WITH VALUES
FROM THE UPPER 70S IN THE MOUNTAINS TO THE MID 80S IN THE PIEDMONT.
&&
.LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 300 PM EDT WEDNESDAY...
UPPER LEVEL FLOW BECOMES ZONAL EARLY NEXT WEEK. THE LOWER BOUNDARY
LAYER FLOW WILL RETURN TO THE SOUTH ALLOWING PULSE STORMS TO
DEVELOP. THIS PATTERN OF AFTERNOON AND EVENING THUNDERSTORMS WILL
PERSIST THROUGH WEDNESDAY AND POSSIBLY INTO THE END OF THE WEEK.
LOOKING BEYOND THE EXTENDED...A COLD FRONT MAY CLEAR THINGS OUT BY
NEXT WEEKEND. TEMPERATURES WILL REMAIN WARM AND MUGGY UNTIL THIS
COLD FRONT PASSES EAST OF THE AREA.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
AS OF 750 AM EDT THURSDAY...
OUTFLOW BOUNDARIES FROM CLUSTERS OF SHOWERS AND THUNDERSTORMS IN
THE OHIO VALLEY WILL BE A TRIGGER FOR SHOWERS AND THUNDERSTORMS
ACROSS THE SOUTHERN APPALACHIANS THIS AFTERNOON.
THIS AFTERNOON REDEVELOPMENT OF THUNDERSTORMS WILL DEPEND ON THE
LOCATIONS OF THE OUTFLOW AND AMOUNT OF HEATING AND INSTABILITY
THAT CAN BE GENERATED IN SPITE OF ANY DEBRIS CLOUDINESS. FOR NOW
WILL GO WITH VCNTY TSRA IN THE TAFS AND REFINE AS NEEDED. BEST
CHANCE FOR STRONG STORMS...WITH A POTENTIAL FOR WIND GUSTS OF 30
TO 40 KNOTS WILL BE EAST OF THE BLUE RIDGE AFTER 4PM. CONFIDENCE
AND PROBABILITY OF OCCURRENCE AT ANY PARTICULAR AIRPORT IS LOW AT
THIS TIME.
A BACKDOOR FRONT DIPS SOUTH TOWARD THE AREA FROM THE MASON-DIXON
LINE TONIGHT WHICH WILL INCREASE THE RANGE OF STORMS INTO MORE
SCATTERED AND MULTICELLULAR AS OPPOSED TO PULSE. MODELS ARE
BRINGING MVFR TO IFR CLOUDS AND FOG INTO THE FORECAST AREA NORTH
OF THE FRONT LATE TONIGHT. BUFKIT SOUNDINGS SHOWED DRIER AIR
COMING IN AT MID AND HIGH LEVELS. IT IS POSSIBLE THAT LOW LVL
BOUNDARY WILL NOT EVEN MAKE IT AS FAR SOUTH AS LYH BEFORE 12Z
FRIDAY...WHICH WOULD GREATLY LOWER THE THREAT OF LATE NIGHT
STRATUS.
EXTENDED AVIATION DISCUSSION...
THE FRONT IS EXPECTED TO PRODUCE BETTER COVERAGE INTO FRIDAY. A
WEAK FLOW PATTERN HOLDING OVER THE WEEKEND WILL KEEP THE STORM
CHANCES EACH AFTERNOON THROUGH EARLY EVENING SAT/SUN.
AREAS OF IFR FOG REMAIN POSSIBLE EACH LATE NIGHT/EARLY MORNING...
PARTICULARLY IN AREAS THAT SEE RAIN THE PREVIOUS AFTERNOON. THE
MOST OPTIMAL FLIGHT CONDITIONS EACH DAY SHOULD BE IN THE MID TO
LATE MORNING AFTER FOG/LOW CLOUDS LIFT AND BURN OFF...AND BEFORE
AFTERNOON CONVECTION REDEVELOPS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS/JH
NEAR TERM...AMS/JH
SHORT TERM...KK
LONG TERM...RCS
AVIATION...AMS/PM
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
958 PM CDT FRI JUN 20 2014
.UPDATE...
ISSUED AT 958 PM CDT FRI JUN 20 2014
FOR NO WEATHER IN THE FORECAST AREA...THERE SURE IS SOME ACTION
AROUND US IN EVERY DIRECTION.
TO THE EAST...HAVE ADJUSTED FORECAST FOR THE WESTWARD MOVING FRONT
WHICH IS MARKED BY LOW CLOUD AND SOME NEAR 1 MILE VISIBILITIES. I
KNOW THE SOLSTICE IS AROUND SUNRISE...BUT THAT IS TOO MUCH OF A
WINTER LOOK TOO SOON. EASTERLY FLOW IS MAXIMIZING NOW THROUGH JUST
AFTER MIDNIGHT AND SHOULD BEGIN TO VEER TOWARD SE-S LATER AS
LOW PRESSURE APPROACHES WI. HAVE BROUGHT CLOUDS TO ABOUT KEAU-KDLL
LINE AND LOWERED TEMPERATURES AND DEWPOINTS OVERNIGHT. HAVE NOT
ADDED FOG YET BUT MAY NEED TO IF VSBYS ARE GOING TO GO LESS THAN 1
MILE.
TO THE SOUTHWEST...CONVECTION IS STAYING BEHAVED AND FEEDING OFF
LOW-LEVEL MOISTURE CONVERGENCE INTO SOUTHERN IA PER RAP MODEL
GUIDANCE. THIS TREND SHOULD CONTINUE. HOWEVER...MOISTURE IN LOW-
LEVELS IS DOING AN END-AROUND WITH W-SWRLY 850-925MB FLOW ACROSS
NRN IA AND SRN MN EASTWARD...WHICH WILL INCREASE THE LOW-LEVEL
DEWPOINTS BY 4C OR SO WITH TROUGH MOVING THROUGH...WARM FRONTAL.
ALTHOUGH RAP FORECASTS SEEM TO INDICATE T/TD ARE STILL SOME 3C
FROM LOW-LEVEL SATURATION...THERE IS SOME CONVERGENCE AND
ELEVATED CAPE SHOULD SATURATION OCCUR IN THAT LAYER...WITH NO CAP.
SO...OVERNIGHT THERE IS A CHANCE FOR A POP-UP SHOWER OR STORM IN
THE 06-12Z TIME FRAME. SOME HI-RES CONVECTIVE ALLOWING MODELS
SUGGEST THIS WITH SOME ECHO SHOWING UP IN WI. SMALL RAIN CHANCES
ARE IN FOR THAT POSSIBILITY /20-30/.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 344 PM CDT FRI JUN 20 2014
AT 3 PM...TWO BOUNDARIES WERE LOCATED ACROSS THE FORECAST AREA.
THE FIRST OF THESE TWO EXTENDS FROM NEW RICHMOND /KRNH/ TO
LA CROSSE WISCONSIN. BOTH THE RAP AND LAPS DATA SHOW 150 TO
200 J/KG OF SURFACE TO 3 KM CAPE...STRONG LAYER ENHANCED
STRETCHING POTENTIAL...STEEP 0-2 KM LAPSE RATES /GREATER THAN
9 C/KM /...AND WEAK TO MODERATE SURFACE RELATIVE VORTICITY. THIS
WOULD BE SUPPORTIVE OF NON-SUPERCELL TORNADOES. THESE CONDITIONS
CONTINUE THROUGH 21.02Z. HOWEVER AT THIS TIME...IT LOOKS LIKE THE
CONVERGENCE WILL NOT BE GREAT ENOUGH FOR THEIR DEVELOPMENT.
A SECOND BOUNDARY LOOKS TO BE EITHER A DRY LINE OR A DIFFERENTIAL
HEATING BOUNDARY ACROSS CENTRAL WISCONSIN. THERE WAS A BRIEF
SHOWER AT WAUSAU. JUST LIKE THE PREVIOUS BOUNDARY...THE
CONVERGENCE IS NOT THAT STRONG ALONG THE BOUNDARY. WITH 2 TO 3K
SURFACE BASED CAPES...WILL HAVE TO MONITOR THIS AREA FOR
DEVELOPMENT.
FURTHER NORTHWEST...A SHORT WAVE TROUGH WAS MOVING ACROSS NORTHERN
MINNESOTA. THIS SYSTEM WAS MOVING THROUGH AN AREA OF 1K SURFACE
CAPES. THIS HAS RESULTED IN THE DEVELOPMENT OF SHOWERS AND STORMS.
WITH THE RAP SHOWING EFFECTIVE SHEAR GREATER THAN 40 KNOTS...AREAS
NORTH OF INTERSTATE 94 WILL HAVE TO BE MONITORED FOR THE POTENTIAL
OF SEVERE WEATHER. THERE IS A BOUNDARY NORTH OF PHILLIPS
WISCONSIN. THIS COULD AID IN THE DEVELOPMENT OF A FEW TORNADOES.
MEANWHILE FURTHER SOUTH...THE THREATS WILL BE LARGE HAIL AND
DAMAGING WINDS. THIS MAY AFFECT CLARK AND TAYLOR COUNTIES LATE
THIS AFTERNOON AND EVENING...BUT THIS IS HIGHLY DEPENDENT ON
WHETHER STORMS CAN EVEN DEVELOP. MANY OF THE MESO MODELS SUGGEST
THAT THIS WILL NOT BE THE CASE.
FINALLY...AN AREA OF SHOWERS AND STORMS ARE DEVELOPING AHEAD OF A
SHORT WAVE TROUGH MOVING OUT OF CENTRAL NEBRASKA. A FEW OF THESE
STORMS HAVE ALREADY BECOME SEVERE. THE GFS...ECMWF...AND ARW
SUGGEST THAT THESE SUPERCELLS WILL DEVELOP INTO A MESOSCALE
CONVECTIVE COMPLEX WHICH WILL MOVE THROUGH OUR AREAS ALONG AND
SOUTH OF INTERSTATE 90 BETWEEN 21.06Z AND 21.15Z. AT THIS
TIME...IT LOOKS LIKE THE 0-3 KM AND 0-6 KM SHEAR WILL BE TOO WEAK
FOR ANY SEVERE WEATHER WITH THIS COMPLEX. ONE THING THAT WILL HAVE
TO WATCHED IS THAT THE HOP WRF AND HRRR SUGGEST THAT THIS COMPLEX
MAY DIVE SOUTHEAST TOWARD THE BETTER INSTABILITY ACROSS
MISSOURI...SO WILL HAVE TO WATCH THIS CLOSELY LATE TONIGHT.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 344 PM CDT FRI JUN 20 2014
THIS PART OF THE FORECAST IS GREATLY COMPLICATED DUE TO ZONAL FLOW
ALOFT. THE EXTENDED MODELS ARE SHOWING VARYING TIMES AND
STRENGTHS OF SHORT WAVES EMBEDDED IN THIS FLOW. OVERALL...THE BEST
CHANCE OF SHOWERS AND THUNDERSTORMS LOOKS TO BE FROM SUNDAY NIGHT
THROUGH MONDAY AS A SHORT WAVE TROUGH MOVES THROUGH THE CENTRAL
PLAINS AND MID MISSISSIPPI RIVER VALLEY...AND FROM TUESDAY THROUGH
WEDNESDAY AS A CANADIAN COLD FRONT DROPS INTO THE AREA. THIS FRONT
WILL LIKELY INCREASE THE SHEAR ACROSS THE AREA FOR THE POTENTIAL
OF SEVERE WEATHER. HOWEVER THERE ARE UNCERTAINTIES ON HOW FAR
SOUTH THIS FRONT WILL GET DUE TO THE ZONAL FLOW. AS A
RESULT...STAYED CLOSE TO THE MODEL CONSENSUS FOR NOW.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 636 PM CDT FRI JUN 20 2014
MAIN AVIATION CONCERN TONIGHT IS FOR LIGHT FOG DEVELOPMENT AT
KLSE...AND WHETHER CONVECTION THAT IS MOVING THROUGH WESTERN IOWA
WILL IMPACT THE TAF SITES. THE COMBINATION OF RECENT RAINS...LIGHT
WINDS IN THE BOUNDARY LAYER...AND A MOIST AIR MASS LENDS SUPPORT
FOR LIGHT FOG AT KLSE...DESPITE THE SUMMER SOLSTICE BEING TONIGHT.
THE BETTER SETUP LOOKS TO BE ACROSS EASTERN WISCONSIN BUT FEEL
THERE COULD BE SOME LIGHT FOG /5 TO 6 SM/ AROUND THE AIRFIELD
EARLY SATURDAY MORNING.
CONVECTION IN WESTERN IOWA IS EXPECTED TO TRACK EASTWARD ACROSS
CENTRAL/NORTHERN IOWA AND NOT IMPACT KRST/KLSE OUTSIDE OF ANVIL
CLOUDS. THERE ARE SCATTERED MID LEVEL CLOUDS MOVING IN FOR THIS
EVENING...WITH BASES AROUND 6 KFT. OTHERWISE...FOR SATURDAY
PLAN ON SOUTHWESTERLY FLOW WITH MID/HIGH LEVEL CLOUDS. CONVECTIVE
PROBABILITIES ARE LOW AT THIS TIME.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...BAUMGARDT
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...ZT
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
636 PM CDT FRI JUN 20 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 344 PM CDT FRI JUN 20 2014
AT 3 PM...TWO BOUNDARIES WERE LOCATED ACROSS THE FORECAST AREA.
THE FIRST OF THESE TWO EXTENDS FROM NEW RICHMOND /KRNH/ TO
LA CROSSE WISCONSIN. BOTH THE RAP AND LAPS DATA SHOW 150 TO
200 J/KG OF SURFACE TO 3 KM CAPE...STRONG LAYER ENHANCED
STRETCHING POTENTIAL...STEEP 0-2 KM LAPSE RATES /GREATER THAN
9 C/KM /...AND WEAK TO MODERATE SURFACE RELATIVE VORTICITY. THIS
WOULD BE SUPPORTIVE OF NON-SUPERCELL TORNADOES. THESE CONDITIONS
CONTINUE THROUGH 21.02Z. HOWEVER AT THIS TIME...IT LOOKS LIKE THE
CONVERGENCE WILL NOT BE GREAT ENOUGH FOR THEIR DEVELOPMENT.
A SECOND BOUNDARY LOOKS TO BE EITHER A DRY LINE OR A DIFFERENTIAL
HEATING BOUNDARY ACROSS CENTRAL WISCONSIN. THERE WAS A BRIEF
SHOWER AT WAUSAU. JUST LIKE THE PREVIOUS BOUNDARY...THE
CONVERGENCE IS NOT THAT STRONG ALONG THE BOUNDARY. WITH 2 TO 3K
SURFACE BASED CAPES...WILL HAVE TO MONITOR THIS AREA FOR
DEVELOPMENT.
FURTHER NORTHWEST...A SHORT WAVE TROUGH WAS MOVING ACROSS NORTHERN
MINNESOTA. THIS SYSTEM WAS MOVING THROUGH AN AREA OF 1K SURFACE
CAPES. THIS HAS RESULTED IN THE DEVELOPMENT OF SHOWERS AND STORMS.
WITH THE RAP SHOWING EFFECTIVE SHEAR GREATER THAN 40 KNOTS...AREAS
NORTH OF INTERSTATE 94 WILL HAVE TO BE MONITORED FOR THE POTENTIAL
OF SEVERE WEATHER. THERE IS A BOUNDARY NORTH OF PHILLIPS
WISCONSIN. THIS COULD AID IN THE DEVELOPMENT OF A FEW TORNADOES.
MEANWHILE FURTHER SOUTH...THE THREATS WILL BE LARGE HAIL AND
DAMAGING WINDS. THIS MAY AFFECT CLARK AND TAYLOR COUNTIES LATE
THIS AFTERNOON AND EVENING...BUT THIS IS HIGHLY DEPENDENT ON
WHETHER STORMS CAN EVEN DEVELOP. MANY OF THE MESO MODELS SUGGEST
THAT THIS WILL NOT BE THE CASE.
FINALLY...AN AREA OF SHOWERS AND STORMS ARE DEVELOPING AHEAD OF A
SHORT WAVE TROUGH MOVING OUT OF CENTRAL NEBRASKA. A FEW OF THESE
STORMS HAVE ALREADY BECOME SEVERE. THE GFS...ECMWF...AND ARW
SUGGEST THAT THESE SUPERCELLS WILL DEVELOP INTO A MESOSCALE
CONVECTIVE COMPLEX WHICH WILL MOVE THROUGH OUR AREAS ALONG AND
SOUTH OF INTERSTATE 90 BETWEEN 21.06Z AND 21.15Z. AT THIS
TIME...IT LOOKS LIKE THE 0-3 KM AND 0-6 KM SHEAR WILL BE TOO WEAK
FOR ANY SEVERE WEATHER WITH THIS COMPLEX. ONE THING THAT WILL HAVE
TO WATCHED IS THAT THE HOP WRF AND HRRR SUGGEST THAT THIS COMPLEX
MAY DIVE SOUTHEAST TOWARD THE BETTER INSTABILITY ACROSS
MISSOURI...SO WILL HAVE TO WATCH THIS CLOSELY LATE TONIGHT.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 344 PM CDT FRI JUN 20 2014
THIS PART OF THE FORECAST IS GREATLY COMPLICATED DUE TO ZONAL FLOW
ALOFT. THE EXTENDED MODELS ARE SHOWING VARYING TIMES AND
STRENGTHS OF SHORT WAVES EMBEDDED IN THIS FLOW. OVERALL...THE BEST
CHANCE OF SHOWERS AND THUNDERSTORMS LOOKS TO BE FROM SUNDAY NIGHT
THROUGH MONDAY AS A SHORT WAVE TROUGH MOVES THROUGH THE CENTRAL
PLAINS AND MID MISSISSIPPI RIVER VALLEY...AND FROM TUESDAY THROUGH
WEDNESDAY AS A CANADIAN COLD FRONT DROPS INTO THE AREA. THIS FRONT
WILL LIKELY INCREASE THE SHEAR ACROSS THE AREA FOR THE POTENTIAL
OF SEVERE WEATHER. HOWEVER THERE ARE UNCERTAINTIES ON HOW FAR
SOUTH THIS FRONT WILL GET DUE TO THE ZONAL FLOW. AS A
RESULT...STAYED CLOSE TO THE MODEL CONSENSUS FOR NOW.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 636 PM CDT FRI JUN 20 2014
MAIN AVIATION CONCERN TONIGHT IS FOR LIGHT FOG DEVELOPMENT AT
KLSE...AND WHETHER CONVECTION THAT IS MOVING THROUGH WESTERN IOWA
WILL IMPACT THE TAF SITES. THE COMBINATION OF RECENT RAINS...LIGHT
WINDS IN THE BOUNDARY LAYER...AND A MOIST AIR MASS LENDS SUPPORT
FOR LIGHT FOG AT KLSE...DESPITE THE SUMMER SOLSTICE BEING TONIGHT.
THE BETTER SETUP LOOKS TO BE ACROSS EASTERN WISCONSIN BUT FEEL
THERE COULD BE SOME LIGHT FOG /5 TO 6 SM/ AROUND THE AIRFIELD
EARLY SATURDAY MORNING.
CONVECTION IN WESTERN IOWA IS EXPECTED TO TRACK EASTWARD ACROSS
CENTRAL/NORTHERN IOWA AND NOT IMPACT KRST/KLSE OUTSIDE OF ANVIL
CLOUDS. THERE ARE SCATTERED MID LEVEL CLOUDS MOVING IN FOR THIS
EVENING...WITH BASES AROUND 6 KFT. OTHERWISE...FOR SATURDAY
PLAN ON SOUTHWESTERLY FLOW WITH MID/HIGH LEVEL CLOUDS. CONVECTIVE
PROBABILITIES ARE LOW AT THIS TIME.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...ZT
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
635 AM CDT THU JUN 19 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 425 AM CDT THU JUN 19 2014
FORECAST TIME WAS SPENT ON IMMEDIATE CONVECTION AND FLOODING
ISSUES...AND THEN THE EVOLUTION AND THREATS THROUGH FRIDAY
MORNING.
ONGOING CONVECTION HAS BEEN REALLY HITTING NORTHEAST IOWA HARD
WITH HEAVY RAIN IN A NEARLY STAGNANT BAND FROM CRESCO TO NEAR
POSTVILLE. RADAR ESTIMATES ARE 5-7 INCHES IN THAT AREA WITH LEGACY
AND DUAL POL...AND IF WE ARE CONSERVATIVE...AT LEAST 4 INCHES HAS
FALLEN ON THAT BAND. THE LATEST TRENDS HAVE THE COMPLEX SLOWLY
SHIFTING SOUTH AS THE COLD POOL DEEPENS. ANOTHER COMPLEX IN
CENTRAL MN IN NOW CANCELLED TORNADO WATCH IS LIFTING NORTHEAST
TIED TO SHORTWAVE TROUGH LIFTING THROUGH THE EASTERN DAKOTAS. THE
SOUTHERN PART OF THAT COMPLEX WILL CLIP THE NORTHWEST MOST
FORECAST AREA WITH STORMS THIS MORNING...BUT THE MAIN STORY IS
NORTHEAST IOWA.
LATEST RAP TRENDS ARE STEADY AND LEND CONFIDENCE THAT THE MOISTURE
TRANSPORT WILL FOCUS NORTHWARD INTO NRN MN AND SOUTHWARD TOWARD
IL/I-80 AS SUNRISE APPROACHES. THIS...IN COMBINATION WITH THE COLD
POOL DEEPENING SHOULD MOVE THE CONVECTION OUT OF NORTHEAST IA AND
SOUTHWEST WI AS THE EARLY MORNING PROGRESSES. 1000 J/KG MUCAPE
LINE PER SPC ANALYSIS IS NOW FROM MINNEAPOLIS TO CHICAGO AND SOUTH
WITH STILL SOME 2000J/KG VALUES TOWARD KALO IN NORTHEAST IOWA. SO
PLENTY OF ENERGY FOR RAINFALL MAKERS.
THE DAYTIME HOURS SEEM TO BE VERY SIMILAR TO PAST DAYS WHERE
CONVECTION WILL BE ON THE DOWNWARD TREND ACROSS THE AREA THIS
MORNING...ONLY TO BUILD CAPE AGAIN THROUGH THE DAY. THE WARM
FRONTAL BOUNDARY WILL AGAIN BE LOCATED TO THE SOUTH AND SHIFT
NORTH THROUGH THE DAY LYING UP AGAIN NEAR A KAEL-KDBQ LINE BY
EVENING. SOME OF THE MODEL GUIDANCE ARE CONVECTING THE THE WARM
FRONT BUT BELIEVE THE CAP SHOULD HOLD AND ALLOW CAPE TO BUILD WITH
NO REAL FORCING ON THAT BOUNDARY EXCEPT WEAK SURFACE CONVERGENCE.
GOES WATER VAPOR IMAGERY DEPICTS THE SHORTWAVE TROUGH IN WYOMING
THAT WILL ROTATE NORTHEAST THROUGH THE UPPER MIDWEST AND PUSH THE
COLD FRONT EASTWARD ACROSS THE FORECAST AREA TONIGHT...A SLOWER
PROGRESSION THAN EARLIER FORECASTS. THE LATEST 19.05 AND 19.06
HRRR RUNS HAVE COME TO EXACTLY WHAT OUR VISUALIZATION IS FOR THE
LATER MORNING AND AFTERNOON. A BREAK...FOLLOWED BY THE COLD FRONT
MOVING INTO 2000 J/KG MLCAPE AND FORMING A LINE OF STORMS TO MOVE
THROUGH THE FORECAST AREA MAINLY THIS EVENING.
WIND SHEAR WITH THIS CONVECTION IS ONLY IN THE 0-3KM LAYER AND
WEAK TO MODERATE...MAYBE 20-25 KTS. WITH THE FRONTAL FORCING
FAVORING A LINE OF CONVECTION AND 0-3KM SHEAR VECTOR ORIENTED
WEST-EAST...BOWING LINE SEGMENTS AND WIND DAMAGE ARE THREAT THAT
IS FAVORED. SPC DAY 1 OUTLOOK LOOKS ABOUT RIGHT WITH MAIN WIND
THREAT COVERAGE WEST OF MISS RIVER. WOULD THINK THAT WI STILL HAS
A CHANCE AT DAMAGING WINDS...BUT LESS IN COVERAGE. THE PROGRESSIVE
NATURE TO THE SYSTEM WILL PROVIDE SOME LIMIT TO THE RAINFALL BUT
WITH PRECIPITABLE WATER OVER 1.5 INCHES AND THE SAME AIR MASS AS
PREVIOUS DAYS...WITH GOOD INSTABILITY BUILDING TODAY...1-2 INCHES
OF RAIN COULD AFFECT MOST AREAS. ONE POTENTIAL PROBLEM WOULD BE
IF THE WARM FRONT DOES CONVECT AS COLD FRONT APPROACHES LATER AND
FORCING INCREASES...AS THAT WOULD PROVIDE A LONGER DURATION RAIN
CHANCE NEAR AND NORTHEAST OF WARM FRONT. THUS...HAVE EXTENDED THE
FLASH FLOOD WATCH THROUGH FRIDAY MORNING /SEE HYDROLOGY SECTION/.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 257 AM CDT THU JUN 19 2014
FRIDAY THROUGH MONDAY...
HERE IS THE GOOD NEWS SECTION FOR THOSE THAT HAVE ENDURED
FLOODING. FRIDAY WILL BE A DRYING DAY WITH THE HIGH PRECIPITABLE
WATER AIR MASS OF 1.8 INCHES SHIFTING EAST POST-FRONTALLY...AND
SOMEWHAT LOWER VALUES OF 1.25 INCHES COMING INTO THE AREA /ABOUT
125-150 PERCENT NORMAL/. CONVECTIVE CHANCES STILL ARE AROUND WITH
WEAK IMPULSES MOVING THROUGH THE AREA AND A BIT STRONGER SHORTWAVE
TROUGH MOVING THROUGH MONDAY. OVERALL...WILL HAVE TO ASSESS THIS
BETTER FRIDAY AFTER THIS HIGHER IMPACT WEATHER MOVES THROUGH. IT
STILL LOOKS LIKE AN ACTIVE PERIOD...AND RAINFALL COULD STILL BE
MODERATE IN RATE...BUT IT SEEMS LESS ORGANIZED EXCEPT FOR MONDAY.
TUESDAY THROUGH WEDNESDAY...
THESE DAYS APPEAR TO BE DRY AND TEMPERATURES PRETTY NORMAL.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 635 AM CDT THU JUN 19 2014
LOW LEVEL JET CONTINUED TO FIRE SHOWERS/STORMS NORTH OF A WARM
FRONT...TRACKING NORTH NORTHEAST INTO SOUTHEAST MN/WESTERN WI. THESE
WILL IMPACT KRST...AND LIKELY KLSE THROUGH 14-15Z. RETREATING JET
SHOULD RESULT IN DIMINISHMENT IN THE AREAL COVERAGE/INTENSITY OF THE
PCPN BY MID MORNING...AND RESULT IN A RELATIVELY DRY PERIOD FROM
LATE MORNING INTO THE MID/LATE AFTERNOON HOURS. STORMS WILL REFIRE
NORTH OF THE WARM FRONT - WAVERING WEST TO EAST ACROSS CENTRAL IA -
AND AHEAD OF A COLD FRONT MARCHING EAST ACROSS MN/IA. TSRA CAN BE
EXPECTED FOR KRST/KLSE DURING THE EVENING...WITH HEAVY RAIN AND
STRONG WIND GUSTS LIKELY. TIMING FOR THE ONSET OF THIS NEXT ROUND IS
NOT CLEAR THOUGH...AND THE FORECAST MAY NEED TO BE MOVED UP A FEW
HOURS. TRENDS WILL HAVE TO BE MONITORED CLOSELY AND FORECASTS
UPDATED AS NEEDED.
&&
.HYDROLOGY...
ISSUED AT 425 AM CDT THU JUN 19 2014
HAVE DECIDED TO EXTENDED THE FLASH FLOOD WATCH TO 7 AM FRIDAY.
MANY AREA SOILS ARE SATURATED FROM THE HEAVY RAINFALL OVER THE
PAST SEVERAL DAYS. LOOKS LIKE ANYWHERE FROM 3-7 INCHES OF
RAIN...POSSIBLY HIGHER WHEN THE TOTALS COME IN THIS MORNING...HAS FALLEN
SINCE SUNDAY IN THE FLASH FLOOD WATCH AREA. WITH A DELAY OF THE
FRONTAL PASSAGE TO MORE ON PEAK HEATING THIS EVENING AND ANOTHER
ROUND OF 1-2 INCHES EXPECTED TONIGHT...DECIDED TO EXTENDED THE
FLASH FLOOD WATCH. DO THINK TONIGHTS LINE OF STORMS WILL BE
PROGRESSIVE BUT STILL COULD PRODUCE ANOTHER 1-2 INCHES VERY
RAPIDLY AND THOSE AREAS THAT ARE VULNERABLE WILL SEE FLASH FLOOD
POTENTIAL. THERE MAY ALSO BE EXISTING AREAL FLOOD WARNINGS IN
PLACE FROM CURRENT RAINFALL IMPACTS. KIND OF A MESS FROM A
SERVICE/PRODUCT STANDPOINT.
RIVERS IN NORTHEAST IOWA WILL NEED AT LEAST MINOR FLOOD WARNINGS
IT APPEARS. WE WILL ASSESS THIS IN THE NEXT SEVERAL HOURS...BUT IT
APPEARS THE UPPER IOWA AND TURKEY RIVERS WILL NEED WARNINGS. THE
TURKEY BASIN TOOK A BIG HIT TO THE HEADWATERS...AND AM HOPING THE
CURRENT RAINS KEEP MOVING SOUTH TO AVOID A TOTAL BASIN POUNDING
AND MORE MODERATE LEVEL FLOODING. THE YELLOW RIVER NEAR POSTVILLE
WAS ABOUT 6 FEET OVER FLOOD STAGE AND ALTHOUGH WE DONT ISSUE
FORECASTS THERE...IT WILL PROBABLY RISE ANOTHER 2-3 FEET TO NEAR
18. THAT IS A STEEP RIVER IN THAT AREA AND THIS IS DANGEROUS
FLOODING...BUT IT IS ALSO MAINLY PASTURE LAND.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR WIZ032>034-041>044-
053>055-061.
MN...FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR MNZ079-086>088-
094>096.
IA...FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR IAZ008>011-018-019-
029-030.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM...BAUMGARDT
AVIATION...BOYNE
HYDROLOGY...BAUMGARDT
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
425 AM CDT THU JUN 19 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 425 AM CDT THU JUN 19 2014
FORECAST TIME WAS SPENT ON IMMEDIATE CONVECTION AND FLOODING
ISSUES...AND THEN THE EVOLUTION AND THREATS THROUGH FRIDAY
MORNING.
ONGOING CONVECTION HAS BEEN REALLY HITTING NORTHEAST IOWA HARD
WITH HEAVY RAIN IN A NEARLY STAGNANT BAND FROM CRESCO TO NEAR
POSTVILLE. RADAR ESTIMATES ARE 5-7 INCHES IN THAT AREA WITH LEGACY
AND DUAL POL...AND IF WE ARE CONSERVATIVE...AT LEAST 4 INCHES HAS
FALLEN ON THAT BAND. THE LATEST TRENDS HAVE THE COMPLEX SLOWLY
SHIFTING SOUTH AS THE COLD POOL DEEPENS. ANOTHER COMPLEX IN
CENTRAL MN IN NOW CANCELLED TORNADO WATCH IS LIFTING NORTHEAST
TIED TO SHORTWAVE TROUGH LIFTING THROUGH THE EASTERN DAKOTAS. THE
SOUTHERN PART OF THAT COMPLEX WILL CLIP THE NORTHWEST MOST
FORECAST AREA WITH STORMS THIS MORNING...BUT THE MAIN STORY IS
NORTHEAST IOWA.
LATEST RAP TRENDS ARE STEADY AND LEND CONFIDENCE THAT THE MOISTURE
TRANSPORT WILL FOCUS NORTHWARD INTO NRN MN AND SOUTHWARD TOWARD
IL/I-80 AS SUNRISE APPROACHES. THIS...IN COMBINATION WITH THE COLD
POOL DEEPENING SHOULD MOVE THE CONVECTION OUT OF NORTHEAST IA AND
SOUTHWEST WI AS THE EARLY MORNING PROGRESSES. 1000 J/KG MUCAPE
LINE PER SPC ANALYSIS IS NOW FROM MINNEAPOLIS TO CHICAGO AND SOUTH
WITH STILL SOME 2000J/KG VALUES TOWARD KALO IN NORTHEAST IOWA. SO
PLENTY OF ENERGY FOR RAINFALL MAKERS.
THE DAYTIME HOURS SEEM TO BE VERY SIMILAR TO PAST DAYS WHERE
CONVECTION WILL BE ON THE DOWNWARD TREND ACROSS THE AREA THIS
MORNING...ONLY TO BUILD CAPE AGAIN THROUGH THE DAY. THE WARM
FRONTAL BOUNDARY WILL AGAIN BE LOCATED TO THE SOUTH AND SHIFT
NORTH THROUGH THE DAY LYING UP AGAIN NEAR A KAEL-KDBQ LINE BY
EVENING. SOME OF THE MODEL GUIDANCE ARE CONVECTING THE THE WARM
FRONT BUT BELIEVE THE CAP SHOULD HOLD AND ALLOW CAPE TO BUILD WITH
NO REAL FORCING ON THAT BOUNDARY EXCEPT WEAK SURFACE CONVERGENCE.
GOES WATER VAPOR IMAGERY DEPICTS THE SHORTWAVE TROUGH IN WYOMING
THAT WILL ROTATE NORTHEAST THROUGH THE UPPER MIDWEST AND PUSH THE
COLD FRONT EASTWARD ACROSS THE FORECAST AREA TONIGHT...A SLOWER
PROGRESSION THAN EARLIER FORECASTS. THE LATEST 19.05 AND 19.06
HRRR RUNS HAVE COME TO EXACTLY WHAT OUR VISUALIZATION IS FOR THE
LATER MORNING AND AFTERNOON. A BREAK...FOLLOWED BY THE COLD FRONT
MOVING INTO 2000 J/KG MLCAPE AND FORMING A LINE OF STORMS TO MOVE
THROUGH THE FORECAST AREA MAINLY THIS EVENING.
WIND SHEAR WITH THIS CONVECTION IS ONLY IN THE 0-3KM LAYER AND
WEAK TO MODERATE...MAYBE 20-25 KTS. WITH THE FRONTAL FORCING
FAVORING A LINE OF CONVECTION AND 0-3KM SHEAR VECTOR ORIENTED
WEST-EAST...BOWING LINE SEGMENTS AND WIND DAMAGE ARE THREAT THAT
IS FAVORED. SPC DAY 1 OUTLOOK LOOKS ABOUT RIGHT WITH MAIN WIND
THREAT COVERAGE WEST OF MISS RIVER. WOULD THINK THAT WI STILL HAS
A CHANCE AT DAMAGING WINDS...BUT LESS IN COVERAGE. THE PROGRESSIVE
NATURE TO THE SYSTEM WILL PROVIDE SOME LIMIT TO THE RAINFALL BUT
WITH PRECIPITABLE WATER OVER 1.5 INCHES AND THE SAME AIR MASS AS
PREVIOUS DAYS...WITH GOOD INSTABILITY BUILDING TODAY...1-2 INCHES
OF RAIN COULD AFFECT MOST AREAS. ONE POTENTIAL PROBLEM WOULD BE
IF THE WARM FRONT DOES CONVECT AS COLD FRONT APPROACHES LATER AND
FORCING INCREASES...AS THAT WOULD PROVIDE A LONGER DURATION RAIN
CHANCE NEAR AND NORTHEAST OF WARM FRONT. THUS...HAVE EXTENDED THE
FLASH FLOOD WATCH THROUGH FRIDAY MORNING /SEE HYDROLOGY SECTION/.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 257 AM CDT THU JUN 19 2014
FRIDAY THROUGH MONDAY...
HERE IS THE GOOD NEWS SECTION FOR THOSE THAT HAVE ENDURED
FLOODING. FRIDAY WILL BE A DRYING DAY WITH THE HIGH PRECIPITABLE
WATER AIR MASS OF 1.8 INCHES SHIFTING EAST POST-FRONTALLY...AND
SOMEWHAT LOWER VALUES OF 1.25 INCHES COMING INTO THE AREA /ABOUT
125-150 PERCENT NORMAL/. CONVECTIVE CHANCES STILL ARE AROUND WITH
WEAK IMPULSES MOVING THROUGH THE AREA AND A BIT STRONGER SHORTWAVE
TROUGH MOVING THROUGH MONDAY. OVERALL...WILL HAVE TO ASSESS THIS
BETTER FRIDAY AFTER THIS HIGHER IMPACT WEATHER MOVES THROUGH. IT
STILL LOOKS LIKE AN ACTIVE PERIOD...AND RAINFALL COULD STILL BE
MODERATE IN RATE...BUT IT SEEMS LESS ORGANIZED EXCEPT FOR MONDAY.
TUESDAY THROUGH WEDNESDAY...
THESE DAYS APPEAR TO BE DRY AND TEMPERATURES PRETTY NORMAL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1230 AM CDT THU JUN 19 2014
STRONG 850 MB MOISTURE TRANSPORT AND 900 TO 700 MB FRONTOGENESIS
WILL CONTINUE TO PRODUCE SHOWERS AND THUNDERSTORMS AT BOTH TAF
SITES THROUGH MUCH OF THE OVERNIGHT...AND THEN BETWEEN 19.10Z AND
19.13Z THE SHOWERS AND THUNDERSTORMS WILL DISSIPATE AS THE LOW
LEVEL JET VEERS AWAY FROM THE AREA. THERE MAY BE SOME AREAS OF
BROKEN MVFR CEILINGS.
ADDITIONAL SHOWERS AND THUNDERSTORMS WILL DEVELOP ACROSS THE AREA
DURING THE AFTERNOON AND EVENING AS THE COLD FRONT APPROACHES.
&&
.HYDROLOGY...
ISSUED AT 425 AM CDT THU JUN 19 2014
HAVE DECIDED TO EXTENDED THE FLASH FLOOD WATCH TO 7 AM FRIDAY.
MANY AREA SOILS ARE SATURATED FROM THE HEAVY RAINFALL OVER THE
PAST SEVERAL DAYS. LOOKS LIKE ANYWHERE FROM 3-7 INCHES OF
RAIN...POSSIBLY HIGHER WHEN THE TOTALS COME IN THIS MORNING...HAS FALLEN
SINCE SUNDAY IN THE FLASH FLOOD WATCH AREA. WITH A DELAY OF THE
FRONTAL PASSAGE TO MORE ON PEAK HEATING THIS EVENING AND ANOTHER
ROUND OF 1-2 INCHES EXPECTED TONIGHT...DECIDED TO EXTENDED THE
FLASH FLOOD WATCH. DO THINK TONIGHTS LINE OF STORMS WILL BE
PROGRESSIVE BUT STILL COULD PRODUCE ANOTHER 1-2 INCHES VERY
RAPIDLY AND THOSE AREAS THAT ARE VULNERABLE WILL SEE FLASH FLOOD
POTENTIAL. THERE MAY ALSO BE EXISTING AREAL FLOOD WARNINGS IN
PLACE FROM CURRENT RAINFALL IMPACTS. KIND OF A MESS FROM A
SERVICE/PRODUCT STANDPOINT.
RIVERS IN NORTHEAST IOWA WILL NEED AT LEAST MINOR FLOOD WARNINGS
IT APPEARS. WE WILL ASSESS THIS IN THE NEXT SEVERAL HOURS...BUT IT
APPEARS THE UPPER IOWA AND TURKEY RIVERS WILL NEED WARNINGS. THE
TURKEY BASIN TOOK A BIG HIT TO THE HEADWATERS...AND AM HOPING THE
CURRENT RAINS KEEP MOVING SOUTH TO AVOID A TOTAL BASIN POUNDING
AND MORE MODERATE LEVEL FLOODING. THE YELLOW RIVER NEAR POSTVILLE
WAS ABOUT 6 FEET OVER FLOOD STAGE AND ALTHOUGH WE DONT ISSUE
FORECASTS THERE...IT WILL PROBABLY RISE ANOTHER 2-3 FEET TO NEAR
18. THAT IS A STEEP RIVER IN THAT AREA AND THIS IS DANGEROUS
FLOODING...BUT IT IS ALSO MAINLY PASTURE LAND.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR WIZ032>034-041>044-
053>055-061.
MN...FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR MNZ079-086>088-
094>096.
IA...FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR IAZ008>011-018-019-
029-030.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM...BAUMGARDT
AVIATION...BOYNE
HYDROLOGY...BAUMGARDT
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1231 AM CDT THU JUN 19 2014
.UPDATE...
ISSUED AT 959 PM CDT WED JUN 18 2014
SHOWERS AND THUNDERSTORMS ARE ERUPTING ALONG THE EDGE OF THE 12C
700 MB CAP AND IN AREA OF MODERATE TO STRONG 900 TO 700 MB
FRONTOGENESIS. IN ADDITION A 30 TO 40 KNOT 850 MB JET IS SURGING
INTO THIS AREA. LATEST RUC ANALYSIS SHOWS THAT THE DEEP MOISTURE
CONVERGENCE HAS DRAMATICALLY INCREASED FROM SIOUX FALLS INTO
NORTHERN ILLINOIS. WITH PRECIPITABLE WATER VALUES RUNNING BETWEEN
1.7 TO 1.9 INCHES AND WARM CLOUD DEPTHS GREATHER THAN 4 KM...HEAVY
RAIN WHICH WILL RESULT IN FLASH FLOODING LOOKS TO BE THE MAIN
CONCERN. HOWEVER THE RAP ANALYSIS DOES SUGGEST THAT THE 0-6 KM
SHEAR WILL BECOME SUPERCELLULAR BETWEEN NOW AND 1 AM...THIS COULD
RESULT IN POCKETS OF DAMAGING WINDS AND LARGE HAIL.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 325 PM CDT WED JUN 18 2014
MAIN FORECAST CONCERNS IS HEAVY RAIN POTENTIAL TONIGHT INTO THURSDAY
MORNING.
LATEST WATER VAPOR SATELLITE IMAGERY SHOWING UPPER LEVEL LOW OVER
THE NORTHERN ROCKY MOUNTAINS AND WEAK SHORTWAVE TROUGHS EMBEDDED IN
THE SOUTHWESTERLY FLOW ALOFT OVER THE CENTRAL UNITED STATES. LATEST
19Z SURFACE ANALYSIS INDICATES WARM FRONT/RESIDUAL OUTFLOW BOUNDARY
EXTENDING FROM SOUTHEAST SOUTH DAKOTA INTO SOUTHERN IOWA.
TONIGHT INTO THURSDAY...THE LATEST 18.12Z GFS/NAM INDICATE MOISTURE
TRANSPORT AND CONVERGENCE TO INCREASE AFTER 00Z THURSDAY WEST OF THE
FORECAST AREA AND SHIFT THE NOSE OF THE MOISTURE TRANSPORT AND
CONVERGENCE INTO FORECAST AREA BY 06Z THURSDAY. WITH SUBTLE WEAK
SHORTWAVE TROUGHS EJECTING OUT OF THE HIGH PLAINS INTO THE UPPER
MIDWEST...EXPECT ANOTHER MCS TO FORM AND MOVE CLOSE TO THE FORECAST
AREA AFTER 03-06Z THURSDAY TIMEFRAME. HOWEVER...THE EXACT LOCATION
OF WHERE THE MCS WILL FORM IS STILL UNCERTAIN AND WILL HAVE AN
IMPACT WHERE HEAVY RAIN WILL FALL OVER FORECAST AREA. THE 18.12Z
GFS/NAM AND 15Z RAP CONTINUE TO SHOW PRECIPITABLE WATER VALUES OF
1.5-2 INCHES ACROSS FORECAST AREA AND WARM CLOUD DEPTH EXTENDING
UP TO 4KM PER BUFKIT SOUNDINGS ACROSS FORECAST AREA. ANY
SHOWERS/THUNDERSTORM DEVELOPMENT OVER FORECAST AREA WILL BE
EFFICIENT RAIN PRODUCERS AND PRODUCE LOCAL HEAVY RAIN. THE 18.12Z
GFS/NAM SUGGEST WEAK SURFACE COLD FRONT TO MOVE ACROSS THE
FORECAST AREA LATE THURSDAY AFTERNOON. THE MODELS INDICATE ENOUGH
MOISTURE CONVERGENCE ALONG THE FRONT TO PRODUCE ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS AND TRACK ACROSS FORECAST AREA THURSDAY
AFTERNOON AND EVENING.
NEXT CONCERN TONIGHT INTO THURSDAY IS SEVERE POTENTIAL...THE 18.12Z
GFS/NAM INDICATE MAINLY ELEVATED INSTABILITY PER BUFKIT SOUNDINGS
AND 0-3KM SHEAR IN THE 25 TO 30 KNOTS RANGE ACROSS FORECAST AREA.
THE MODELS SUGGEST ALL SHEAR IN THE 0-3KM LAYER...AS THE 0-6KM SHEAR
SHOWS ABOUT 30 TO 35 KNOTS. AT THIS TIME...LOOKING AT DAMAGING
WINDS...LARGE HAIL AND FLASH FLOODING FROM HEAVY RAINFALL THE MAIN
THREATS MAINLY SOUTH OF INTERSTATE 94.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 325 PM CDT WED JUN 18 2014
WEST TO EAST ZONAL FLOW DEVELOPS ACROSS THE NORTHERN TIER STATES
FRIDAY AND SATURDAY. THE 18.12Z GFS/NAM SHOW WEAK IMPULSES EMBEDDED
IN THE FLOW WITH ENOUGH MOISTURE CONVERGENCE AND LIFT IN ASSOCIATION
WITH EACH IMPULSE...SHOULD ALLOW THE POSSIBILITY OF SHOWERS AND
THUNDERSTORMS ACROSS FORECAST AREA.
SATURDAY NIGHT THROUGH WEDNESDAY...MAIN FORECAST CONCERNS ARE
PRECIPITATION CHANCES THROUGH THE PERIOD. THE 18.12Z
GFS/ECMWF/GEM ARE IN GOOD AGREEMENT IN DIGGING UPPER LEVEL TROUGH
OVER THE GREAT LAKES REGION EARLY NEXT WEEK. SIGNIFICANT
DIFFERENCES ARE INDICATED BETWEEN THE MODELS WITH TIMING OF
SHORTWAVE TROUGHS EMBEDDED IN THE WEST TO EAST ZONAL FLOW SATURDAY
NIGHT INTO SUNDAY AND THE STRENGTH OF THE UPPER LEVEL TROUGH
DIGGING OVER THE GREAT LAKES REGION EARLY NEXT WEEK. THIS WILL
HAVE IMPACTS ON TIMING OF MOISTURE RETURN/PRECIPITATION CHANCES
INTO THE FORECAST AREA SUNDAY INTO MONDAY. NEXT CONCERN ARE
TEMPERATURES FOR MIDDLE OF NEXT WEEK. WITH THE 18.12Z GFS/ECMWF
DIFFERING SLIGHTLY ON STRENGTH OF UPPER LEVEL TROUGH OVER THE
GREAT LAKES REGION...THE 18.12Z GFS/ECMWF DIFFER ON HOW COOL
AIRMASS WILL BE OVER THE FORECAST AREA...WITH THE 18.12Z ECMWF
ADVECTING IN SLIGHTLY COOLER TEMPERATURES THAN THE 18.12Z GFS.
THE 18.12Z ECMWF SHOWING 850MB TEMPERATURES PLUS 10 TO PLUS 12
DEGREES CELSIUS OVER FORECAST AREA...COMPARED TO PLUS 12 TO PLUS
14 DEGREES CELSIUS 850MB TEMPERATURES BY THE 18.12Z GFS.
TEMPERATURES OVER FORECAST AREA BY MIDDLE OF NEXT WEEK LOOK TO BE
UNSEASONABLY COOL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1230 AM CDT THU JUN 19 2014
STRONG 850 MB MOISTURE TRANSPORT AND 900 TO 700 MB FRONTOGENESIS
WILL CONTINUE TO PRODUCE SHOWERS AND THUNDERSTORMS AT BOTH TAF
SITES THROUGH MUCH OF THE OVERNIGHT...AND THEN BETWEEN 19.10Z AND
19.13Z THE SHOWERS AND THUNDERSTORMS WILL DISSIPATE AS THE LOW
LEVEL JET VEERS AWAY FROM THE AREA. THERE MAY BE SOME AREAS OF
BROKEN MVFR CEILINGS.
ADDITIONAL SHOWERS AND THUNDERSTORMS WILL DEVELOP ACROSS THE AREA
DURING THE AFTERNOON AND EVENING AS THE COLD FRONT APPROACHES.
&&
.HYDROLOGY...
ISSUED AT 325 PM CDT WED JUN 18 2014
THE FORECAST AREA REMAINS IN A VERY MOIST AND UNSTABLE AIRMASS
THROUGH THURSDAY EVENING WITH PRECIPITABLE WATER VALUES IN THE 1.5
TO 2 INCH RANGE AND WARM CLOUD DEPTHS UP TO 4 KM. THE COMBINATION
OF ANOTHER ROUND OF CONVECTION TO IMPACT THE FORECAST AREA TONIGHT
AND RECENT HEAVY RAINFALL THE LAST COUPLE OF DAYS...WILL CONTINUE
WITH THE FLASH FLOOD WATCH FOR SOUTHEAST MINNESOTA...NORTHEAST
IOWA...SOUTHWEST AND CENTRAL WISCONSIN THROUGH THURSDAY MORNING.
ALSO...DUE TO THE RECENT HEAVY RAINFALL...THE
CEDAR...TREMPEALEAU AND BLACK RIVERS HAVE RISEN OR ARE FORECASTED
TO RISE ABOVE FLOOD STAGE AND FLOOD WARNINGS ARE IN EFFECT
PORTIONS OF THESE RIVERS. SEE THE LATEST FLOOD STATEMENTS FOR
EXACT FORECAST DETAILS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...FLASH FLOOD WATCH UNTIL 7 AM CDT THIS MORNING FOR WIZ032>034-
041>044-053>055-061.
MN...FLASH FLOOD WATCH UNTIL 7 AM CDT THIS MORNING FOR MNZ079-086>088-
094>096.
IA...FLASH FLOOD WATCH UNTIL 7 AM CDT THIS MORNING FOR IAZ008>011-018-
019-029-030.
&&
$$
UPDATE...BOYNE
SHORT TERM...DTJ
LONG TERM...DTJ
AVIATION...BOYNE
HYDROLOGY...DTJ
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
345 AM CDT SAT JUN 21 2014
.DISCUSSION...
339 AM CDT
THE BASIC PATTERN THAT HAS NOW BEEN IN PLACE FOR NEARLY A WEEK WILL
CONTINUE THROUGH MONDAY...WHICH MEANS NUMEROUS FORECAST CHALLENGES
ON THIS SUMMER SOLSTICE. MORNING FOG AND STRATUS IS FIRST IN THE
TIMELINE FOLLOWED BY ITS IMPACT ON TEMPERATURES AND
DESTABILIZATION FOR THUNDERSTORM COVERAGE THIS AFTERNOON.
QUANTIFYING ANY SEVERE POTENTIAL ALSO NEEDED TO BE ASSESSED.
FINALLY...CONTINUED THUNDERSTORM CHANCES...ESPECIALLY THROUGH
MONDAY NIGHT...ROUNDED OUT THE FORECAST THIS MORNING.
FOG AND TEMPERATURES...
DENSE FOG THAT HAD EXPANDED INLAND LAST EVENING BEHIND THE
IMPRESSIVE LAKE BREEZE,,,WHICH AS OF 330 AM HAS FINALLY STALLED
NEAR INTERSTATE 74...CONTINUES OVER LAKE ADJACENT COUNTIES. WEB
CAMS AND REPORTS INDICATE THIS IS MOST DENSE NEAR THE LAKE SHORE
AND WILL CONTINUE THE DENSE FOG ADVISORY THROUGH 9 AM...WITH
POTENTIALLY SOME SHORELINE LOCALES DOWN TO A FEW HUNDRED FEET
VISIBILITY. VAD PROFILES INDICATE THE NORTHEAST FLOW IS ABOUT
2000-3000FT THICK AND AN AMDAR SOUNDING FROM LAST EVE INDICATES
SATURATION IS ONLY ABOUT HALF OF THAT. WITH THIS BEING THE LONGEST
DAYLIGHT OF THE YEAR ONE WOULD THINK WE COULD MIX THROUGH THIS
QUICKLY...ESPECIALLY WITH THE SOURCE FLOW OFF THE LAKE HAVING
CONSIDERABLY WEAKENED. THE ONE CONCERN WITH THAT IS CONVECTIVE
DEBRIS CLOUDS ARE SPREADING OVER THIS WHICH WILL FURTHER INSULATE
THIS MORNING. SO THAT WILL NEED TO BE WATCHED. HAVE ADJUSTED
FORECAST HOURLY TEMPERATURES TO SLOW THE RATE OF WARMING
CONSIDERABLY AND THAT LED TO COOLER HIGH TEMPERATURES. WHILE
TEMPERATURES WILL COULD DEPEND ON CONVECTIVE INITIATION TIME AND
COVERAGE /SEE BELOW/...FEEL THAT UNDERCUTTING GUIDANCE AND CLIMO
WAS THE WAY TO GO...OWING TO THE MUCH COOLER-THAN-NORMAL WATER
TEMPERATURES OF LAKE MICHIGAN WHICH FED THIS AREA OF FOG/STRATUS.
THUNDERSTORM POTENTIAL...
MULTIPLE LOW AMPLITUDE UPPER DISTURBANCES WILL TRANSLATE EASTWARD
TODAY ACROSS A BELT OF ZONAL FLOW EXTENDING FROM THE CENTRAL PLAINS
OVER THE FORECAST AREA. THIS IS ON THE NORTHERN END OF CONTINUED
HIGH PRECIPITABLE WATER AND UNSTABLE AIR. ONGOING CONVECTION ACROSS
WESTERN AND CENTRAL IA AS OF 330 AM HAS WEAKENED CONSIDERABLY WITH
ONLY MARGINAL MOISTURE TRANSPORT FEEDING IT. DOES LOOK LIKE THE
SHORT WAVE MAY BE CONVECTIVELY ENHANCED WITH A POSSIBLE MCV AND
TIMING THAT FEATURE SEEMS KEY FOR OUR MAIN STORM CHANCES TODAY.
THE SUITE OF GUIDANCE VARIES CONSIDERABLY AND GIVEN THAT AND
SIMPLY THE TRICKY SYNOPTIC POSITION WE ARE IN...AS WELL AS THE
MESOSCALE FACTOR OF THE CURRENT FOG/STRATUS...CONFIDENCE IS LOW
ON THUNDERSTORM COVERAGE AND TIMING TODAY.
INCREASE POPS GRADUALLY THIS MORNING WITH SOME SCATTERED ELEVATED
STORMS POSSIBLE IN NORTH CENTRAL IL...AND THEN MORE SO EARLY THIS
AFTERNOON AS MID-LEVEL FEATURE PASSES OVER THE FORECAST AREA.
CONVECTIVE TEMPERATURES LOOK TO BE AROUND 80 DEGREES AND NOT
CERTAIN IF PARTS OF NORTHEAST IL WILL REACH THAT...SO KEEP HIGHER
POPS MAINLY ALONG AND SOUTH OF THE MORE STABLE LOW-LEVEL AIR IN
PLACE /JUST SOUTH OF CHICAGO/. THIS ALSO IS WHERE LOW-LEVEL
CONVERGENCE EXISTS...ALBEIT WITH AWFULLY WEAK FLOW. SO AM NOT
ENVISIONING GREAT COVERAGE OF AFTERNOON STORMS BUT ENOUGH TO
SUPPORT 40 TO 50 PERCENT POPS AND HAVE GONE WITH SCATTERED
WORDING. CONVECTIVE CELLS POSSIBLY BECOMING MORE MULTICELL WITH
SMALL-SCALE COLD POOLS ARE THE PROBABLE EVOLUTION. MID-LEVEL LAPSE
RATES ARE POOR AND THE THERMODYNAMIC ENVIRONMENT LOOKS ALREADY
HINDERED BY THE INVERSION IN PLACE...SO NOT EXPECTING MUCH FOR
HAIL...BUT SOME OF THE MORE ORGANIZED STORMS COULD HAVE AN
ISOLATED WIND THREAT DUE TO PRECIP LOADING AND SOME HIGHER
DOWNDRAFT CAPE INDICATED BY A FEW HIGH-RES MODELS. THIS WOULD
SEEM A LITTLE MORE FAVORED SOUTH OF A ROCKFORD TO RENSSELAER LINE.
TONIGHT...
GRADUAL WARM AIR ADVECTION AND ANOTHER ONE OR TWO MINOR IMPULSES MAY
CONTINUE SEPARATE SCATTERED STORMS FROM THE EARLIER ACTIVITY AFTER
DARK...NAMELY OVER THE WESTERN AND SOUTHERN FORECAST AREA. IN
ADDITION...LIGHT WIND FLOW ELSEWHERE MAY ALLOW STRATUS AND/OR FOG TO
DEVELOP. THIS AGAIN WOULD BE ESPECIALLY FAVORED NEAR THE LAKE SHORE.
HAVE ADDED FOG MENTION ONCE AGAIN IN CHICAGO BEGINNING LATER THIS
EVE.
SUNDAY AND MONDAY...
WARM AIR ADVECTION IS FORECAST TO INCREASE ON SUNDAY WITH THE CHANCE
FOR SCATTERED STORMS. MODEL GUIDANCE IS IN GOOD AGREEMENT WITH
NOTHING OVERLY ORGANIZED...SO HAVE KEPT POPS NEAR WHERE THEY
WERE. TEMPERATURES AGAIN WILL BE TRICKY...REMAINING MUCH COOLER
NEAR THE LAKE AND POTENTIALLY HAVING TO FIGHT THROUGH MORNING
STRATUS. HEIGHT FALLS ARE EXPECTED TO SPREAD INTO THE FORECAST
AREA ON MONDAY AND THAT LOOKS TO PRESENT THE BEST CHANCE FOR
STORMS INCLUDING INTO MONDAY NIGHT AS THE FRONT APPROACHES AND
MOVES THROUGH. PRECIPITABLE WATER IS ANTICIPATED TO CLIMB BACK
TO NEAR 1.75 INCHES WITH STRONG DEEP LAYER MOISTURE CONVERGENCE.
WHILE THE DEEP LAYER SHEAR IS NOT PARTICULARLY STRONG OWING TO THE
MARGINAL MID-LEVEL FLOW...ENOUGH INSTABILITY AND FOCUS IS PRESENT
WITH THE SYNOPTIC PATTERN TO WARRANT A HIGHER LIKELIHOOD FOR RAIN.
THE MORE SUN AND GREATER INSTABILITY ON MONDAY THEN THE LIKELY
BETTER CHANCES FOR SOME SEVERE POSSIBILITY.
TUESDAY AND BEYOND...
LONG RANGE GUIDANCE IS IN DECENT AGREEMENT WITH RAIN CHANCES
DIMINISHING THROUGH TUESDAY WITH THE AIR MASS BEING SOMEWHAT
SCOURED OUT SEEING DEW POINTS FORECAST DOWN INTO THE LOWER 60S. THE
UPPER AND MID-LEVEL PATTERN WILL KEEP US SOMEWHAT
UNSETTLED...THOUGH DEEP MOISTURE AND INSTABILITY WILL BE LESS.
HAVE A LOT OF SMALL POPS BUT THE OVERALL PATTERN TUE-THU DOES NOT
LOOK CONDUCIVE FOR HIGH IMPACT WEATHER. ONSHORE FLOW ON A FEW
MIDWEEK DAYS LOOKS TO KEEP TEMPERATURES ONCE AGAIN QUITE A BIT
COOLER NEAR THE LAKE.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* LIFR/VLIFR CIGS OVERNIGHT INTO EARLY SATURDAY MORNING.
* IFR VIS LIKELY OVERNIGHT INTO EARLY SATURDAY MORNING.
* IMPROVEMENT TO VFR LIKELY SATURDAY MORNING...TIMING UNCERTAIN.
* CHANCE TSRA SATURDAY AFTERNOON AND EARLY EVENING.
KREIN
//DISCUSSION...UPDATED 06Z...
LAKE BREEZE FRONT THAT SWEPT THROUGH THE CHICAGO METRO TERMINALS
CONTINUES TO PUSH INLAND AND IS APPROACHING RFD. BEHIND THIS
BOUNDARY A DEEP MARINE LAYER IS SETTING UP WITH LOW STRATUS
PUSHING WELL INLAND...WHILE THE LOWEST VISIBILITIES ARE REMAINING
CLOSER TO THE LAKE. ANTICIPATE THAT RFD/DPA SHOULD KEEP VIS IN
MVFR RANGES...BUT CIGS SHOULD DROP TO IFR/LIFR LEVELS. THE CHICAGO
METRO TERMINALS SHOULD SEE LITTLE IMPROVEMENT UNTIL A FEW HOURS
AFTER SUNRISE WHEN THE HIGH SUN ANGLE WILL ALLOW THE LOW STRATUS
AND FOG TO BURN OFF. THE TIMING OF IMPROVEMENT IS STILL A LITTLE
QUESTIONABLE...BUT CLIMATOLOGICALLY...14Z IS A TYPICAL BURN OFF
TIME.
THE NEXT CONCERN WILL BE THUNDERSTORM CHANCES SATURDAY AFTERNOON.
THE LATEST HIGH RES MODEL GUIDANCE SUGGESTS THAT THE CONVECTIVE
ACTIVITY CURRENTLY OVER SERN NE/SWRN IA WILL TRACK EWD OVERNIGHT.
THIS ACTIVITY SHOULD WEAKEN AS IT PASSES EWD OVERNIGHT BUT SHOULD
STRENGTHEN AGAIN DURG THE AFTERNOON HOURS. CURRENTLY...ANTICIPATE
THAT THE REJUVENATED CONVECTIVE COMPLEX SHOULD MOVE THROUGH
NRN/CNTRL IL DURG THE AFTERNOON HOURS...SO HAVE INTRODUCED A
PROB30 GROUP TO THE TAFS. THERE IS SOME UNCERTAINTY AS TO THE NRN
EXTEND OF THE CONVECTIVE ACTIVITY WITH SOME GUIDANCE SUGGESTING
THE THE NRN EXTENT OF THE TSRA WILL BE ALONG THE I-80
CORRIDOR...REMAINING SOUTH OF THE TERMINALS...WHILE OTHER GUIDANCE
SUGGESTS THAT THE TERMINALS WILL BE RIGHT IN THE TRACK OF THE
THUNDER. SO...GIVEN THIS UNCERTAINTY...WILL GO WITH A PROB30 TO
TREND THE TS CHANCES UPWARD AND THEN REFINE AS THE SITUATION
BECOMES A BIT MORE CLEAR.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE IN LIFR/VLIFR CIGS TONIGHT...LOW CONFIDENCE IN
TIMING OF IMPROVEMENT TO VFR SATURDAY.
* HIGH CONFIDENCE IN WINDS TONIGHT...MEDIUM CONFIDENCE IN WINDS BY
SATURDAY AFTERNOON.
* LOW CONFIDENCE IN TSRA TIMING AND COVERAGE SATURDAY AFTERNOON.
KREIN
//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...
SUNDAY...CHANCE OF TSRA...OTHERWISE GENERALLY VFR.
MONDAY AND MONDAY NIGHT...A PERIOD OF TSRA LIKELY.
TUESDAY AND THURSDAY...GENERALLY VFR.
IZZI
&&
.MARINE...
245 AM CDT
HIGH PRESSURE CENTERED WILL SIT OVER JAMES BAY THROUGH SATURDAY
NIGHT WITH WEAK RIDGING EXTENDING SOUTH ACROSS LAKE MICHIGAN TO
THE LOWER MISSISSIPPI VALLEY. A WEAK STATIONARY FRONT IS DRAPED
FROM NORTHERN MINNESOTA...JUST SOUTH OF THE LAKE TO THE OHIO
VALLEY. WITH WARM...MOIST AIR SPREADING OVER THE COLD LAKE WATER
AND SHIP OBS AND COASTAL SITES AND WEB CAMS INDICATING DENSE
FOG...A DENSE FOG ADVISORY HAS BEEN ISSUED FOR ALL OF THE OPEN
WATERS AND THE ILLINOIS AND INDIANA NEARSHORE WATERS. HAVE
EXTENDED THE DENSE FOG ADVISORY THROUGH SUNDAY MORNING AS THERE
WILL BE LITTLE CHANGE TO THE AIRMASS OVER THE LAKE. THE EXCEPTION
MAY BE THE FAR NORTHERN PORTION OF THE LAKE...WHERE WINDS SHOULD
TREND A LITTLE MORE EASTERLY THAN SOUTHERLY AND ADVECT SOME DRIER
AIR OVER THE LAKE...LIMITING THE DENSE FOG POTENTIAL. A COMPLEX
AREA OF LOW PRESSURE OVER THE CENTRAL PLAINS WITH MULTIPLE LOW
PRESSURE CENTERS...WILL GRADUALLY MOVE EAST ACROSS THE PLAINS AND
TO THE WESTERN GREAT LAKES REGION BY EARLY MONDAY. A WEAK COLD
FRONT SHOULD PUSH ACROSS THE LAKE MONDAY OR MONDAY NIGHT...TURNING
WINDS FROM GENERALLY SOUTHERLY TO MORE NORTHERLY. AS A LARGE AREA
OF HIGH PRESSURE BUILDS OUT OF CANADA TO THE UPPER GREAT LAKES
TUESDAY NIGHT AND WEDNESDAY...COOLER...DRIER AIR WILL OVERSPREAD
THE LAKE. THE COMBINATION OF THE FRONTAL PASSAGE AND THE BUILDING
HIGH PRESSURE SHOULD BRING AN END TO THE FOG POTENTIAL.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...DENSE FOG ADVISORY...ILZ006-ILZ014 UNTIL 9 AM SATURDAY.
IN...DENSE FOG ADVISORY...INZ001-INZ002 UNTIL 9 AM SATURDAY.
LM...DENSE FOG ADVISORY...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-
LMZ565-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-
LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-LMZ870-
LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 10 AM SUNDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
[top]
Area Forecast Discussion
National Weather Service Lincoln IL
314 AM CDT Sat Jun 21 2014
.DISCUSSION...
ISSUED 248 AM CDT Sat Jun 21 2014
Surface ridging keeping control on a relatively stagnant airmass
over the region. Showers, thunderstorms, and mesoscale boundaries
controlling much of the dynamics for the last few days...and the
trend will continue for the next few. Significant wave over NE/IA
this morning progged to make its way over the Mississippi River
Valley later this afternoon/evening and bring the next best
chances of rain. However, some of the models weaken the impulse
considerably, keeping the main wave further to the west for Sun
night through Mon night. To say that the models, both high res and
longer range, have been having a hard time resolving the
convective elements in this hot and humid airmass is a drastic
understatement. Forecast is full of pops and it is almost
impossible to carve them down with much accuracy simply because it
is a hot, humid, and unstable summer airmass. Scattered
thunderstorms is more the rule than the exception, particularly in
the afternoon (diurnal influence) and evening (evolution of
convective masses that form elsewhere and propagate through.)
SHORT TERM...Today and tomorrow...
Hot and humid again today with weak sfc winds and heat indices
into the 90s by late afternoon. GFS and NAM both relentless with
the progression of the convection over NE/IA this morning, pushing
into ILX this afternoon. HRRR and 4km wrf a little more familiar
to recent trends and dissipates the storms as they approach the
Miss River Valley and the influence of the ridge, but refire the
outflow later in the afternoon. More recent HRRR delaying the
refire until closer to 20z over Mid Miss River...whereas the 4km
wrf igniting on several different boundaries through the
afternoon. Considering the lack of consensus...will go with a
combination of models, and continuity. Chances through the day,
increasing this afternoon and into the evening hours. Tomorrow
even less clear--scattered potential, and details potentially more
accessible after the prev activity from tonight sets up any
outflow boundaries. Both days in the warm and humid airmass and
heat indices into the 90s.
LONG TERM...Monday through Friday...
Upper trof/wave pushing through the region on Monday night into
Tuesday bringing signif chance, increasing from Sun night into
Monday night...and a slightly cooler Tuesday through the end of
the week. Still warm, but potentially less humidity as winds
become more westerly on Tuesday, picking up a northerly component
by Wednesday. Forecast trending drier from Tuesday through
Wednesday. Another wave Thursday brings back some pops ahead of
the next big storm system developing over the SW for late next
weekend.
HJS
&&
.AVIATION...
ISSUED 1123 PM CDT Fri Jun 20 2014
Quiet/VFR aviation weather conditions expected across the central
Illinois terminals through the bulk of the 06Z TAF valid time.
Surface temperature/dew point spreads are pretty small at the
moment, and this my combine with light winds and mostly clear
skies to allow MVFR fog to develop by late tonight. However, so
far, visibilities in the area as staying up for the most part. For
Saturday, attention turns to the large, nearly stationary, storm
complex that continues to expand over the central plains. While
model agreement is far from good with the details, the remnants of
this storm complex (or the arrival of the features helping to
force it) may impact the area during the midday and afternoon
hours. Scattered, diurnally driven, showers/storms are also
possible even if the complex never makes it. However, kept mention
no better than a VCTS mention at this time given the very low
confidence in the convective details. Winds should generally be
AOB 10 kts outside of any thunderstorms through the period.
Bak
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
249 AM MDT SAT JUN 21 2014
.SHORT TERM...(TODAY THROUGH MONDAY NIGHT)
ISSUED AT 246 AM MDT SAT JUN 21 2014
A RIDGE OVER THE PLAINS WILL FLATTEN SOME TONIGHT. FLOW WILL BECOME
ZONAL ON SUNDAY AND THEN TURN NORTHWEST MONDAY/MONDAY NIGHT. A
SURFACE TROUGH WILL BE NEAR NORTHEAST COLORADO TODAY THROUGH
SUNDAY. A FRONT WILL MOVE INTO THE CENTRAL PLAINS SUNDAY
AFTERNOON. HIGH PRESSURE WILL BUILD INTO THE CENTRAL PLAINS SUNDAY
NIGHT AND CONTINUE THROUGH MONDAY NIGHT.
EARLY MORNING CONVECTION IS HANDLED WELL BY THE HRRR AND SHOULD
PERSIST ACROSS THE NORTHERN AND EASTERN ZONES TILL AROUND 16Z. POPS
WILL BE CHANCE AND LIKELY FOR THESE STORMS.
STORM INITIATION SHOULD TAKE PLACE NEAR THE SURFACE TROUGH THIS
AFTERNOON OVER EASTERN COLORADO AND EXTREME SOUTHWEST NEBRASKA.
STORMS WILL DRIFT EAST INTO THE REST OF THE FA DURING THE LATE
AFTERNOON/EVENING. SHEAR VALUES OF 30 TO 40 KTS WILL BE FAVORABLE
FOR STORMS TO BECOME SEVERE WITH LARGE HAIL AND DAMAGING WIND. CAPE
VALUES WILL RANGE FROM 1000 TO ALMOST 3000 J/KG WITH HIGHEST VALUES
OVER THE NORTHWEST FA. SUBSIDENCE WILL MOVE INTO THE FA LATE
SATURDAY NIGHT/SUNDAY MORNING SO POPS WILL BE NIL FOR THAT BRIEF
PERIOD SUNDAY MORNING. BY SUNDAY AFTERNOON THE FRONT WILL MOVE SOUTH
WITH CONVECTION ALONG AND BEHIND IT. INITIALLY STORM MOVEMENT IS
NEARLY PARALLEL TO THE FRONT IN THE AFTERNOON. HOWEVER THE MODELS
TAKE THE FRONT SOUTH ACROSS THE FA RATHER QUICKLY. BY EVENING STORM
MOVEMENT IS ALMOST PERPENDICULAR TO THE FRONT MINIMIZING ANY
TRAINING THUNDERSTORMS. PLAN TO KEEP LIKELY POPS ALONG AND BEHIND
THE FRONT WITH CHANCE POPS AHEAD OF THE FRONT. OVERNIGHT POPS WILL
DECREASE TO CHANCE AND SLIGHT CHANCE. ON MONDAY STORMS WILL DEVELOP
OVER THE HIGHER TERRAIN IN COLORADO AND DRIFT EAST. PLAN TO KEEP AT
LEAST CHANCE POPS FOR MONDAY AFTERNOON AND NIGHT.
MAX TEMPERATURES TODAY WILL RISE TO THE LOWER 90S. HIGH
TEMPERATURES SUNDAY RANGE FROM 85 TO 90. COOLER READINGS IN THE
UPPER 70S AND LOWER 80S ARE FORECAST FOR MONDAY. MIN TEMPERATURES
WILL VARY FROM THE UPPER 50S TO THE LOWER 60S.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 246 AM MDT SAT JUN 21 2014
AN UNSETTLED WEATHER PATTERN WILL CONTINUE FOR THE EXTENDED
PERIOD...WITH THE CHANCE FOR SHOWERS AND THUNDERSTORMS THROUGH
THURSDAY AND A POSSIBLE BREAK ON FRIDAY. SEVERAL SHORTWAVE TROUGHS
WILL MOVE THROUGH THE CWA...AND EVEN WITH A WEAK RIDGE MOVING OVER
THE CWA ON WEDNESDAY...SHORTWAVES EMBEDDED WITHIN THE FLOW WILL
CONTINUE THE CHANCE FOR SHOWERS AND THUNDERSTORMS. TUESDAY THROUGH
THURSDAY A LEE SURFACE LOW WILL EXIST OVER EASTERN COLORADO WITH A
QUASI STATIONARY SURFACE BOUNDARY EXTENDING SOUTHWARD FROM THE LOW.
INSTABILITY IS PRESENT OVER THE CWA THROUGHOUT THE EXTENDED...ALONG
WITH DECENT LOW LEVEL MOISTURE...AND FAVORABLE BULK SHEAR.
HOWEVER...TRYING TO TIME OUT THE PASSAGE OF EACH SHORTWAVE TROUGH
AND THE POSITION OF SURFACE BOUNDARIES IS A LITTLE DIFFICULT AT THIS
TIME...SO WILL HOLD OFF ON GETTING SPECIFIC WITH MENTION OF WHEN
SEVERE THUNDERSTORMS WILL OCCUR EVEN THOUGH IT COULD BE LIKELY
THROUGH THURSDAY. MODELS ARE NOT IN AGREEMENT WITH THE POSITION OR TIMING OF
THESE FEATURES AND MODEL SPREAD ONLY INCREASES FURTHER OUT INTO THE
EXTENDED.
FRIDAY IS KEPT DRY FOR NOW...EVEN THOUGH THE NEW RUN OF THE ECMWF HAS
A DEEP...NEGATIVELY TILTED TROUGH DIGGING FURTHER SOUTH INTO THE
SOUTHERN ROCKIES AND SOUTHWESTERN UNITED STATES. THE GFS DOES NOT
TAKE THE UPPER TROUGH THIS FAR SOUTH AND KEEPS IT IN THE PACIFIC
NORTHWEST BUT DEVELOPS A DRYLINE THURSDAY AFTERNOON THAT WAVERS BACK
WEST OVER THE CWA ON FRIDAY. AS PREVIOUSLY MENTIONED...WITH MODELS
BEING IN DISAGREEMENT THROUGHOUT THE EXTENDED...CONFIDENCE IN THE
EXTENDED FORECAST IS FAIRLY LOW. FOR THE MOST PART ACCEPTED THE
ALLBLEND...WITH A FEW MINOR ADJUSTMENTS HERE AND THERE. TEMPERATURES
WILL STEADILY INCREASE THROUGHOUT THE WEEK...WITH HIGHS IN THE LOW
TO MID 80S ON TUESDAY RISING INTO THE LOW TO MID 90S BY FRIDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1147 PM MDT FRI JUN 20 2014
VFR CONDITIONS WILL PREVAIL THOUGH THE PERIOD AND SOUTHERLY WINDS
SHOULD GENERALLY REMAIN IN THE 10-15KT RANGE AT BOTH KGLD AND
KMCK. THERE COULD BE SOME GUSTS AROUND 20KT AT EITHER TERMINAL
LATE AFTERNOON/EARLY EVENING SATURDAY...HOWEVER THERE IS SOME
MODEL SPREAD ON SURFACE GRADIENT AND OVERLY CONFIDENCE IN THIS
ISNT HIGH. THUNDERSTORMS HAVE REDEVELOPED OVER NE
COLORADO...HOWEVER THEY HAVE STRUGGLED TO MAKE MUCH EASTWARD
PROGRESS AND SHORT RANGE GUIDANCE FAVORS THIS ACTIVITY REMAINING
OUTSIDE THE VICINITY OF EITHER TERMINAL DURING THE EARLY TAF
PERIOD. ADDITIONAL THUNDERSTORM IS EXPECTED TO DEVELOP OVER
EASTERN COLORADO SATURDAY AFTERNOON AND INCREASE IN COVERAGE AT
BOTH TERMINALS THROUGH SATURDAY EVENING. I INTRODUCED A
PREVAILING THUNDER GROUP AT BOTH TERMINALS FOR PERIODS WITH BEST
MODEL OVERLAP IN TIMING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...FS
LONG TERM...ALW
AVIATION...DR
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
346 AM CDT SAT JUN 21 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 346 AM CDT SAT JUN 21 2014
THE MCS ACROSS NORTHEAST COLORADO IS CLEARLY SHOWING CYCLONIC
ROTATION ON RADAR AND IS TRACKING EAST NORTHEAST TOWARD SWRN NEB
THIS MORNING. THE FORECAST TRACKS IT THROUGH SWRN NEB THIS MORNING
AND ALLOWS FOR DECAY BY 14Z-15Z. THE RAP AND HRRR MODELS DO NOT
HANDLE THIS FEATURE SO THE FORECAST IS HAND DRAWN FOR NOW WITH
SCATTERED POPS BECOMING ISOLATED.
AN ACTIVE SEVERE WEATHER DAY IS EXPECTED THIS AFTERNOON AND TONIGHT.
THE MODEL CONSENSUS SUGGESTS STORMS WOULD FIRE ACROSS NORTHWEST
NEBRASKA AROUND 21Z AND GROW UPSCALE EAST AND SOUTHEAST THROUGHOUT
THE EVENING HOURS. THE MODELS ARE STRUGGLING WITH TEMPERATURES AND
DEW POINTS. THE HRRR...GEMREG AND ECM SEEMED TO HAVE A BETTER HANDLE
ON DEW POINTS AND DEVELOP VERY HIGH SFC BASED CAPE ACROSS WRN/NCNTL
NEB. VALUES OF 3000-4000 J/KG DEVELOP WITH LITTLE OR NO CAP WHICH IS
CONSISTENT WITH THE AFTN CONDITIONS LATELY.
A STRONG MID LEVEL DISTURBANCE...CURRENTLY ACROSS NRN NEVADA WILL BE
CROSSING THE CNTL/NRN PLAINS LATE THIS AFTN AND A PACIFIC COLD FRONT
SWEEPS PART WAY THRU THE FCST AREA TONIGHT. THIS SETS UP A BROAD AND
WEAKLY CAPPED WARM SECTOR COVERING MOST OF THE FCST AREA THIS AFTN.
THE NAM AND RAP MODELS BACK THE SFC WINDS ACROSS NRN NEBRASKA THIS
AFTN HEIGHTENING THE SEVERE WEATHER THREAT. IN GENERAL WINDS ALOFT
ARE WEAK IN THE MODEL SOLNS BUT GIVEN THE STRENGTH OF THE UPPER
LEVEL DISTURBANCE ACROSS THE WRN U.S. THE SHEAR COULD BE STRONGER
TODAY THAN FRIDAY.
THERE IS A BROAD SPREAD IN BULK SHEAR SHOWN IN THE MODELS AT 00Z
THIS EVENING RANGING FROM LESS THAN 20 KT TO 35 KT AT BOTH NORTH
PLATTE AND VALENTINE. USING THE HIGHER VALUES SUGGESTS POTENTIAL FOR
SUPERCELL DEVELOPMENT AT BOTH LOCATIONS BUT THIS WOULD BE MORE
LIKELY ACROSS THE WEST WITH THE SYSTEM EVOLVING INTO A QLMCS AS IT
MOVES EAST INTO DEEPER MOISTURE ACROSS NCNTL NEB THIS EVENING. SPC
REMAINS UNCERTAIN ON HOW THIS SYSTEM WILL EVOLVE SINCE THE MODELS
SHOW A FULL SPECTRUM OF CONVECTIVE OPPORTUNITIES ACROSS THE BLACK
HILLS AND THE NEBRASKA PANHANDLE TODAY.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 346 AM CDT SAT JUN 21 2014
12Z SUNDAY AND BEYOND. THE FOCUS OF EXTENDED PERIODS...AT LEAST
INITIALLY...WILL BE ON THE TIMING AND LOCATION OF A FRONTAL
BOUNDARY POISED TO CROSS WESTERN AND NORTH CENTRAL NEBRASKA
SUNDAY. CONTRARY TO PREVIOUS MODEL RUNS...THE SOLUTIONS NOW SEEM
TO KEEP THE FRONT MOVING THROUGH THE CWA FAIRLY
PROGRESSIVELY...BUT THERE REMAINS CONSIDERABLE UNCERTAINTY ON HOW
SUNDAY WILL PLAY OUT...ESPECIALLY SINCE A FAIRLY SIGNIFICANT MCS
IS SHOWN TO DEVELOP SATURDAY NIGHT/EARLY SUNDAY ACROSS MUCH OF THE
CENTRAL SANDHILLS AND PROJECT EAST OVERNIGHT. THUS CONFIDENCE IS
SOMEWHAT LOWER THAN USUAL...BUT WHERE STORMS FIRE SUNDAY
AFTERNOON...STEEP LAPSE RATES...A MODERATE TO STRONGLY UNSTABLE
ATMOSPHERE AND SUFFICIENT SHEAR WOULD PROMOTE MULTI CELL UPDRAFTS
CAPABLE OF LARGE HAIL AND GUSTY WIND. GIVEN THE CURRENT
UNCERTAINTY...FELT THAT SUB 50 PERCENT POPS WERE ALL THAT WERE
NEEDED BEFORE 00Z MONDAY. THEREAFTER...THERE IS SOME AGREEMENT IN
THE SOLUTIONS THAT STORMS WILL FOCUS ACROSS OUR EASTERN AND
SOUTHERN ZONES...FOR THIS AREA WILL MAINTAIN HIGH END CHANCE
POPS...BUT NOT VENTURE INTO THE LIKELY REALM YET.
THE GREATEST CHANGE MADE TO THE INHERITED FORECAST IS NOTED ON
MONDAY AS THE SURFACE BOUNDARY IS NOW SHOWN TO BE WELL SOUTH AND
EAST OF THE CWA...THUS POPS WERE LOWERED TO ACCOUNT FOR THIS NEW
MODEL PROJECTION. WITHIN THE POST FRONTAL AIRMASS ON MONDAY AND
TUESDAY...TEMPERATURES WILL BE PLEASANT...WITH HIGHS GENERALLY IN
THE 70S FOR MOST LOCATIONS.
NORTHWEST FLOW ALOFT DEVELOPS ACROSS THE HIGH PLAINS EARLY NEXT WEEK
AS A NORTHERN PLAINS LOW DROPS SOUTH INTO THE EASTERN DAKOTAS...WITH
RIDGING NOSING INTO THE CENTRAL ROCKIES. WEAK EASTERLY UPSLOPE FLOW
WILL INTERACT WITH STRONG WARMING OFF THE HIGH PLAINS OF EASTERN
COLORADO/WYOMING TO PROMOTE STORM DEVELOPMENT MONDAY AFTERNOON. A
FEW OF THESE STORMS COULD DRIFT SOUTHEAST INTO WESTERN/SOUTHWEST
PORTIONS OF THE CWA WITH A STRONG OR LOW END SEVERE STORM POSSIBLE.
NORTHWEST FLOW CONTINUES TO DIRECT WEAK IMPULSES ACROSS THE HIGH
PLAINS INTO CENTRAL SANDHILLS...ADDITIONAL STORM CHANCES WILL BE
POSSIBLE THROUGH MID-WEEK. THEREAFTER...SUPPORT REMAINS FOR A
DEEPENING TROUGH ACROSS THE WESTERN CONUS...WHICH WOULD PROMOTE
SOUTHWEST FLOW ATOP THE CENTRAL PLAINS...SOUTHERLY SURFACE FLOW
RETURNS. THE PATTEN MAY RETURN ACTIVE LATE WEEK AS ADDITIONAL
ENERGY/EML IS DIRECTED NORTHEAST FROM THE WESTERN CONUS TROUGH TOWARD
THE CENTRAL PLAINS. AFTER HIGHS IN THE 70S EARLY NEXT
WEEK...TEMPERATURES GRADUALLY WARM INTO THE UPPER 80S TO LOWER 90S
BY LATE...LOWS TO REMAIN SEASONAL THROUGH THE EXTENDED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1212 AM CDT SAT JUN 21 2014
THE THUNDERSTORM COMPLEX IN CENTRAL AND SOUTHWEST NEBRASKA IS
EXPECTED TO MOVE INTO EASTERN NEBRASKA BY 07Z. SHORT RANGE
PROJECTIONS INDICATE THAT ANOTHER SMALL SYSTEM MAY DEVELOP IN
WYOMING AND MOVE ACROSS SOUTHWEST NEBRASKA. HOWEVER...RAIN-COOLED
AIR FROM THE STORM SYSTEM THAT JUST WENT THROUGH HAS PROBABLY
STABILIZED THE ATMOSPHERE ENOUGH THAT IT IS UNLIKELY.
THUNDERSTORMS ARE AGAIN EXPECTED SATURDAY AFTERNOON...STARTING WEST
OF VTN-LBF 18-21Z AND SPREADING TO ANW-BBW 21-24Z. COVERAGE IS STILL
EXPECTED TO BE LESS THAN 40 PERCENT...SO THEY WILL NOT BE INCLUDED
IN THE TERMINAL FORECASTS FOR VTN OR LBF.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...JACOBS
AVIATION...SPRINGER
AREA FORECAST DISCUSSION
NWS RALEIGH NC
310 AM EDT SAT JUN 21 2014
.SYNOPSIS...AN UPPER DISTURBANCE WILL MOVE SOUTHEAST ACROSS THE AREA
TODAY. A WEAK COLD FRONT WILL PUSH SOUTHEAST THROUGH CENTRAL NORTH
CAROLINA TONIGHT...USHERING IN SLIGHTLY COOLER AND DRIER WEATHER FOR
SUNDAY AND MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 310 AM SATURDAY...
RADAR SHOWS A FAIRLY WELL DEFINED MCV MOVING ALONG THE NC/VA BORDER
NORTH OF KIXA...WITH AND OUTFLOW BOUNDARY EXTENDING THROUGH THE
COASTAL PLAIN TO THE SOUTHERN PIEDMONT. THE ASSOCIATED SHOWERS AND
STORMS ARE NOW MOSTLY EAST OF THE CWA. SUBSIDENCE BEHIND THE MCV
SHOULD KEEP ANY ADDITIONAL SHOWERS VERY ISOLATED THIS
MORNING...WHILE ATTENTION TURNS TO A SHORTWAVE UPSTREAM OVER EASTERN
TN/KY...WHICH IS PROGGED TO CROSS THE CWA BETWEEN 15Z AND 21Z. WITH
THE COLD FRONT OVER VA SINKING SOUTH AND A WEAK WAVE OF LOW PRESSURE
ASSOCIATED WITH THE SHORTWAVE SETTLED ACROSS THE AREA THIS
AFTERNOON...LOW-LEVEL CONVERGENCE...ALBEIT WEAK...WILL BE FOCUS OVER
NC. THE TIMING OF THE SHORTWAVE SHOULD CAUSE SCATTERED SHOWERS AND
STORMS OVER THE WESTERN PIEDMONT TO BECOME MORE NUMEROUS EAST OF
ROUGHLY US HWY 1 BY EARLY AFTERNOON AS IT ENCOUNTERS PEAK HEATING
AND MLCAPE OVER 1000 J/KG. THE SEVERE THREAT APPEARS TO BE
LIMITED GIVEN WEAK WIND FIELDS AND ONLY MARGINAL INSTABILITY...BUT
WITH PW OF UP TO 2 INCHES...RAIN WILL BE HEAVY AND THE SHORTWAVE MAY
LOCALLY ENHANCE THE THREAT OF DAMAGING WINDS IF A FEW STORMS CAN
CONGEAL INTO A LARGER CLUSTER. HIGHS IN THE UPPER 80S NORTH TO
LOWER 90S SOUTH.
TONIGHT... EXPECTED SHOWERS AND STORMS TO LARGELY COME TO AN END
BEHIND THE PASSING SHORTWAVE BY 03Z. IN ITS WAKE...THE
AFOREMENTIONED COLD FRONT WILL FINALLY SURGE SOUTH THROUGH THE
AREA...WHICH MAY TRIGGER A FEW ADDITIONAL SHOWERS. WILL END CHANCE
POPS AFTER MIDNIGHT WITH JUST A SLIGHT CHANCE THEREAFTER. LOWS IN
THE MID 60S NORTH TO LOWER 70S SOUTH.
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
AS OF 310 AM SATURDAY...
THE COLD FRONT WILL SLIP SOUTH OVER SC ON SUNDAY AS HIGH PRESSURE
BUILDS OVER THE MID-ATLANTIC STATES AND PW DROPS BACK TOWARD NORMAL.
LOW-LEVEL CONVERGENCE AND THE AXIS OF BEST INSTABILITY WILL
ACCORDINGLY BE SOUTH OF THE CWA...WITH JUST A SLIGHT CHANCE OF A
SHOWER OR STORM FROM THE SOUTHERN PIEDMONT TO THE SOUTHERN COASTAL
PLAIN. LOW-LEVEL THICKNESSES DROP BACK SLIGHTLY BELOW NORMAL TO
AROUND 1395...WHICH SUGGESTS HIGHS IN THE MID TO UPPER 80S. RETURN
FLOW WILL BEGIN TO DEVELOP SUNDAY NIGHT INTO MONDAY..THOUGH MODELS
LOOK A BIT TOO AGGRESSIVE WITH STRATUS OVER THE WESTERN PIEDMONT
MONDAY MORNING. LOWS IN THE MID TO UPPER 60S.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 230 AM SATURDAY...
CYCLE TOWARDS A WARMER...MOISTER...AND MORE ACTIVE AIRMASS CONTINUES
THROUGH THE WEEK AS SURFACE HIGH PRESSURE RETREATS AND LOW LEVEL
FLOW VEERS EAST TO SOUTHEAST MONDAY AND TUESDAY. INITIALLY...THE
AIRMASS WILL BE ONLY MODESTLY UNSTABLE MONDAY WITH WEAK LOW LEVEL
FORCING AND SHORT WAVE RIDGING ALOFT. THIS SHOULD WILL LIMIT
CONVECTION TO THE FAR WEST...WITH ONLY A SLIGHT CHANCE FOR A FEW
STORMS TO MIGRATE INTO THE PIEDMONT. HIGHS MONDAY WILL BE
SEASONABLE...FROM 85 TO 90. LEE SURFACE TROF RE-DEVELOPS AND
PRECIPITABLE WATER INCREASES TO NEAR 2 INCHES BY TUESDAY AFTERNOON
AND DIURNAL CONVECTION WILL BE MORE WIDESPREAD...POTENTIALLY
LINGERING OVERNIGHT AS A SHORTWAVE APPROACHES FROM THE WEST. HIGHS
TUESDAY WILL REACH THE UPPER 80S TO LOWER 90S.
POTENTIAL FOR AT LEAST SCATTERED CONVECTION WILL LINGER WEDNESDAY
THROUGH FRIDAY IN THE DEEPLY MOIST AIRMASS WITH HIGHS REACHING THE
LOWER 90S AFTER MORNING MINS WITHIN A FEW DEGREES RIGHT OR LEFT OF
70. MID LEVEL FLOW WILL BE NEAR-ZONAL WITH LOW AMPLITUDE TROFFING
OVER THE GREAT LAKES PROVIDING FAVORABLE STEERING FLOW FOR UPSTREAM
DISTURBANCES TO ENHANCE COVERAGE AND ORGANIZATION OF EXPECTED
CONVECTION.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 140 AM SATURDAY...
A BROKEN LINE OF SHOWERS AND STORMS IS NOW MOSTLY EAST OF ALL TAF
SITES..THOUGH A FEW SHOWERS STILL INGER TO THE WEST-NORTHWEST OF
KFAY AND MAY STILL IMPACT THE TERMINAL THROUGH 07Z. AREAS OF LOW
CLOUDS AND REDUCED VSBY WILL CONTINUE THROUGH THE REMAINDER OF THE
NIGHT...PARTICULARLY WHERE MORE RAIN FEEL. CURRENT THINKING IS THAT
VSBYS WILL REMAIN MOSTLY MVFR KRDU/KRWI/KFAY....WITH A BETTER CHANCE
OF VSBYS DROPPING TO IFR OR LIFR AT KRWI. THE HRRR MODEL ALSO
SHOWS SOME STRATUS DEVELOPING JUST TO THE WEST OF KFAY BY 09Z...SO
THIS WILL BE MONITORED.
TODAY... STRONG HEATING ALONG WITH AN UPPER DISTURBANCE AND WEAK
COLD FRONT WILL LEAD TO SCATTERED TO NUMEROUS SHOWERS AND
STORMS...AS EARLY AS 15Z AT KINT/KGSO AND MORE LIKELY AFTER 18Z AT
KRDU/KFAY/KRWI (WHERE CONFIDENCE IS HIGHEST). A FEW STORMS MAY BE
STRONG TO SEVERE. ONCE THE STORMS MOVE EAST OF CENTRAL NC DURING
THE EVENING HOURS...WINDS WILL BECOME MORE NORTH-NORTHEASTERLY
BEHIND THE COLD FRONT AS IT SETTLES SOUTH INTO SC.
OUTLOOK... THERE WILL BE SLIGHT CHANCES FOR DIURNAL CONVECTION
THROUGH THE WEEKEND AND THE BEGINNING OF NEXT WEEK. CHANCES INCREASE
ON TUESDAY AND WEDNESDAY AFTERNOONS WITH A GREATER THREAT FOR SUB-
VFR CONDITIONS. THERE WILL BE ALSO CHANCES FOR EARLY MORNING
FOG/STRATUS TUESDAY AND WEDNESDAY MORNINGS.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MLM
NEAR TERM...BLS
SHORT TERM...BLS
LONG TERM...MLM
AVIATION...BLS/ELLIS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
140 AM EDT SAT JUN 21 2014
.SYNOPSIS... WITH A WARM AND UNSTABLE AIR MASS IN PLACE... A SERIES
OF UPPER LEVEL DISTURBANCES WILL TRACK SOUTHEAST ACROSS THE REGION
TODAY. A COLD FRONT WILL PUSH SOUTHEAST THROUGH CENTRAL NORTH
CAROLINA TONIGHT.
&&
.NEAR TERM /THROUGH SATURDAY NIGHT/...
AS OF 1010 PM FRIDAY...
TONIGHT: AN MCV NEAR THE VA CAMPBELL/CHARLOTTE COUNTY LINE...AND A
TRAILING ONE NEAR THE WV/VA BORDER...WILL TRACK ESE TO THE EASTERN
VA-NE NC COAST BY EARLY SAT. THE LEAD MCV HAS SUPPORTED THE
MAINTENANCE OF A RECENTLY STRENGTHENING CLUSTER OF STORMS IN A
LOOSELY-ORGANIZED ARC FROM THE CENTRAL-SOUTHERN VA PIEDMONT
SOUTHWARD TO NEAR KHNZ THEN SOUTHWESTWARD TO KEXX. THE ASSOCIATED
STORMS/SFC COLD POOLS EASTWARD MOVEMENT WILL MAINTAIN ENHANCED STORM
RELATIVE FLOW/CONVERGENCE...OWING TO AN EASTERLY SFC FLOW COMPONENT
TO THE NORTH OF THE LEAD SFC FRONT OVER SOUTHERN NC...AND SHOULD
CONSEQUENTLY MAINTAIN THE STORM CLUSTER AS IT MARCHES EAST ACROSS
THE FAR NE PIEDMONT AND NORTHERN COASTAL PLAIN DURING THE NEXT
COUPLE OF HOURS. THOUGH THESE STORMS ARE NOT TERRIBLY REFLECTIVE AS
A RESULT OF ONLY MARGINAL MLCAPE OF 1500 J/KG OR LESS DUE TO WEAK
MID LEVEL LAPSE RATES AND NOCTURNAL COOLING...00Z-OBSERVED
PRECIPITABLE WATER VALUES OF AROUND 1.75 INCHES AT BOTH KGSO AND
KMHX...IN CONJUNCTION WITH THE STRONG CONVERGENCE/FAVORABLE STORM
RELATIVE FLOW ORIENTED PERPENDICULAR TO THE STORM CLUSTER/COLD POOL
BOUNDARY...HAS RESULTED IN RELATIVELY DEEP AND WIDE PRECIPITATION
CORES SUPPORTIVE OF STRONG TO EVEN MARGINALLY SEVERE DOWNDRAFTS...
AND HEAVY RAIN.
WEAK CINH AND LINGERING INSTABILITY WILL SUPPORT ISOLATED TO WIDELY
SCATTERED STORMS ELSEWHERE ACROSS CENTRAL NC TONIGHT...WITH THE BEST
COVERAGE WITH THE AFOREMENTIONED ONGOING CLUSTER NEAR THE VA
BORDER...WHERE MCV-RELATED FORCING WILL BE RELATIVELY MAXIMIZED.
PREVIOUSLY FORECAST LOWS 68-73. -MWS
FOR SAT/SAT NIGHT: NOCTURNAL CONVECTION IN THE NORTHEAST CWA SHOULD
BE EXITING THE CWA NEAR OR SOON AFTER DAYBREAK... FOLLOWED BY A
PERIOD OF RELATIVE SUBSIDENCE THROUGH THE REST OF THE MORNING...
AGAIN FOLLOWING THE TRENDS OF THE HIGH-RES WRF-NMM AND WRF-ARW.
THEN... THE PRESENCE OF THE OLD MCV ACROSS SRN AND ERN NC ALONG WITH
GOOD HEATING THROUGH THE FIRST PART OF THE DAY SHOULD HELP FUEL
SCATTERED TO NUMEROUS SHOWERS AND STORMS. WE COULD SEE A COMBINATION
OF MOUNTAIN CONVECTION PUSHING TO THE ESE THROUGH CENTRAL NC DURING
THE AFTERNOON... IN ADDITION TO STORMS FORMING OVER THE ERN
PIEDMONT/SANDHILLS/COASTAL PLAIN WHERE DEWPOINTS SHOULD BE HIGHEST
WITH THE LONGEST PERIOD OF HEATING... AND ALONG AND AHEAD OF A
SURFACE LOW OVER CENTRAL NC. HIGHER TEMPS/DEWPOINTS HERE WILL
POTENTIALLY PUSH MUCAPE UP TO 1500-2500 J/KG... ALBEIT WITH
CONTINUED WEAK DEEP LAYER SHEAR OF JUST AROUND 20 KTS. PW VALUES IN
THE EAST ARE ALSO EXPECTED TO PEAK OVER 2 INCHES BY LATE IN THE
DAY... FAVORING GOOD STORM COVERAGE AND POTENTIAL HEAVY RAIN WITH
SLOW MOVING CELLS. THIS ALL BOILS DOWN TO HIGH PRECIP CHANCES (60-
70%) OVER ALL OF CENTRAL NC SAT AFTERNOON INTO THE EVENING. COOL
SURFACE HIGH PRESSURE WELL TO OUR NNW WILL PUSH THE LOW AND FRONT TO
OUR SE SAT NIGHT... CAUSING A WIND SHIFT TO NORTH THEN NE LATE...
BRINGING AN END TO PRECIP CHANCES FROM NW TO SE. WE SHOULD SEE
FORMATION OF LOW CLOUDS POST-FRONT OVER THE EASTERN HALF OF THE CWA
WITHIN THE NNE FLOW. HIGHS 85-94 FROM NNE TO SW. LOWS 65 NORTH TO 72
SOUTH. -GIH
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 230 PM FRIDAY...
SURFACE LOW PRESSURE WILL BE MOVING OFFSHORE TO BEGIN THE DAY ON
SUNDAY...WITH HIGH PRESSURE GRADUALLY BUILDING EAST AND DOWN THE
EAST COAST THROUGH MONDAY. THIS WILL PUSH A FRONT FURTHER SOUTH OF
THE FORECAST AREA...LIKELY INTO SC/GA. IN ADDITION...SHORTWAVE
RIDGING WILL ALSO BUILD EAST OVER THE REGION. THEREFORE...THIS TIME
FRAME OF ENTIRE FORECAST PERIOD IS WHEN PRECIP CHANCES WILL BE THE
LOWEST... ALTHOUGH NON-ZERO. SUNDAY SHOULD BE THE DRIEST DAY (WITH
ONLY A FEW ISOLATED STORMS EXPECTED)...THEN MAYBE SOME HIGHER
CHANCES ACROSS THE WEST ON MONDAY AS THE HIGH STARTS TO PULL AWAY
AND MOISTURE BEGINS TO INCREASE ON THE BACK SIDE OF THE DEPARTING
HIGH. TEMPS WILL BE A SEVERAL DEGREES LOWER THAN PREVIOUS DAYS BEHIND
THE FRONT...WITH HIGHS EXPECTED TO BE IN THE MID/UPPER 80S TO NEAR
90 DEGREES AND OVERNIGHT LOWS IN THE MID/UPPER 60S TO NEAR 70
DEGREES.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 230 PM FRIDAY...
PRECIP CHANCES...MOSTLY DIURNAL IN NATURE...WILL BEGIN TO INCREASE
ON TUESDAY AND THEN PERSIST FOR THE REMAINDER OF THE WEEK AS
MOISTURE INCREASES WITHIN THE RETURN FLOW THAT SETS UP ON THE
BACKSIDE OF THE DEPARTING HIGH. IN ADDITION...FLOW ALOFT WILL BECOME
SOUTHWESTERLY (THUS INCREASING DEEP LAYER MOISTURE) AS LARGE SCALE
TROUGHING MOVES OVER THE GREAT LAKES AND MS RIVER VALLEY.
ADDITIONALLY...TEMPS WILL CLIMB A FEW DEGREES...WITH HIGHS GENERALLY
IN THE UPPER 80S TO LOWER 90S AND OVERNIGHT LOWS IN THE UPPER 60S TO
LOWER 70S.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 140 AM SATURDAY...
A BROKEN LINE OF SHOWERS AND STORMS IS NOW MOSTLY EAST OF ALL TAF
SITES..THOUGH A FEW SHOWERS STILL INGER TO THE WEST-NORTHWEST OF
KFAY AND MAY STILL IMPACT THE TERMINAL THROUGH 07Z. AREAS OF LOW
CLOUDS AND REDUCED VSBY WILL CONTINUE THROUGH THE REMAINDER OF THE
NIGHT...PARTICULARLY WHERE MORE RAIN FEEL. CURRENT THINKING IS THAT
VSBYS WILL REMAIN MOSTLY MVFR KRDU/KRWI/KFAY....WITH A BETTER CHANCE
OF VSBYS DROPPING TO IFR OR LIFR AT KRWI. THE HRRR MODEL ALSO
SHOWS SOME STRATUS DEVELOPING JUST TO THE WEST OF KFAY BY 09Z...SO
THIS WILL BE MONITORED.
TODAY... STRONG HEATING ALONG WITH AN UPPER DISTURBANCE AND WEAK
COLD FRONT WILL LEAD TO SCATTERED TO NUMEROUS SHOWERS AND
STORMS...AS EARLY AS 15Z AT KINT/KGSO AND MORE LIKELY AFTER 18Z AT
KRDU/KFAY/KRWI (WHERE CONFIDENCE IS HIGHEST). A FEW STORMS MAY BE
STRONG TO SEVERE. ONCE THE STORMS MOVE EAST OF CENTRAL NC DURING
THE EVENING HOURS...WINDS WILL BECOME MORE NORTH-NORTHEASTERLY
BEHIND THE COLD FRONT AS IT SETTLES SOUTH INTO SC.
OUTLOOK... THERE WILL BE SLIGHT CHANCES FOR DIURNAL CONVECTION
THROUGH THE WEEKEND AND THE BEGINNING OF NEXT WEEK. CHANCES INCREASE
ON TUESDAY AND WEDNESDAY AFTERNOONS WITH A GREATER THREAT FOR SUB-
VFR CONDITIONS. THERE WILL BE ALSO CHANCES FOR EARLY MORNING
FOG/STRATUS TUESDAY AND WEDNESDAY MORNINGS.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...MWS/HARTFIELD
SHORT TERM...KRD
LONG TERM...KRD
AVIATION...BLS/ELLIS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
349 AM CDT SAT JUN 21 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 327 AM CDT SAT JUN 21 2014
LATEST SEVERAL HRRR RUNS HAVE INSISTED THAT SHOWER ACTIVITY OVER
FAR EASTERN MONTANA WILL HOLD TOGETHER...EVEN EXPANDING AND
STRENGTHENING...WILL SLIDE EASTWARD THIS MORNING AND THEN
DISSIPATE OVER SOUTHEASTERN NORTH DAKOTA. IT SEEMS REASONABLE
BASED ON THE PAST FEW HOURS OF SATELLITE AND RADAR INTERROGATION.
THE MORE PRESSING CONCERN IS FOR POSSIBLE SEVERE THUNDERSTORMS
THIS AFTERNOON AND EVENING SOUTH OF INTERSTATE 94. SPC SLID THEIR
CONVECTIVE OUTLOOK SLIGHT RISK TO THE NORTH THIS MORNING. ML CAPE
IS EXPECTED TO BE IN THE 1500 J/KG BALLPARK...AND SHEAR WILL BE
SUPPORTIVE OF SUPERCELLS.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 327 AM CDT SAT JUN 21 2014
THE EXTENDED PERIOD WILL BE MODERATELY ACTIVE FOR THIS TIME OF THE
YEAR WITH TWO FEATURES BRINGING PRECIPITATION TO THE REGION. FIRST
THE REMNANTS OF THE UPPER LOW ACROSS SASK/MANT WILL SWING SOUTH
THROUGH THE NORTHERN PLAINS MONDAY AND TUESDAY BRINGING SCATTERED
SHOWERS/THUNDERSTORMS TO THE REGION. SUFFICIENT INSTABILITY EXISTS
FOR ROUTINE THUNDERSTORMS WITH NOTHING SCREAMING SEVERE POTENTIAL AT
THIS TIME. A CHANGE TO COOLER WEATHER ALSO IS ANTICIPATED AS THIS
LOW WILL BRING COOLER H850 TEMPS WITH IT. FOLLOWING THIS THE
ECMWF/GFS BOTH ARE BRINGING EASTERN PACIFIC SHORTWAVE ENERGY INTO
WESTERN NORTH AMERICA AND ARE CARVING OUT A LONGWAVE TROUGH ACROSS
THE WESTERN US. THE EUROPEAN SEEMS TO BE MORE AGGRESSIVE WITH A
FASTER AND DEEPER TROUGH. EITHER WAY THE RESULT WILL BE A SOUTHWEST
FLOW ALOFT...WITH AN OPENING TO GULF MOISTURE AND EVENTUALLY A MORE
ACTIVE THUNDERSTORM PATTERN FOR THE LAST WEEK OF JUNE. USING
ALLBLEND GUIDANCE RESULTS IN A CHANCE OF THUNDERSTORMS WEDNESDAY
TROUGH FRIDAY WITH NORMAL TO ABOVE NORMAL TEMPERATURES RETURNING BY
THE END OF THE WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 327 AM CDT SAT JUN 21 2014
AN AREA OF SHOWERS AND THUNDERSTORMS SHOULD FORM BEFORE SUNRISE
AND MOVE EASTWARD FROM KDIK TO KBIS AND KJMS. ANOTHER ROUND OF
STRONGER THUNDERSTORMS SHOULD FORM AROUND 21Z NEAR KBIS/KJMS.
KISN/KMOT SHOULD REMAIN DRY AND VFR.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SCHECK
LONG TERM...WAA
AVIATION...SCHECK
AREA FORECAST DISCUSSION
NWS BISMARCK ND
102 AM CDT SAT JUN 21 2014
.UPDATE...
ISSUED AT 1241 AM CDT SAT JUN 21 2014
THE 03 AND 04 UTC HRRR RUNS HAVE INSISTED THAT PRECIPITATION OVER
SOUTHEASTERN MONTANA WILL PROPAGATE INTO SOUTHERN NORTH DAKOTA
AROUND 10 UTC...THEN SLIDE EASTWARD INTO THE JAMES RIVER VALLEY BY
17 UTC. RECENT SATELLITE IMAGERY AND 00 UTC NAM AGREE THAT A
PORTION OF THE SOUTHERN ALBERTA MIDDLE LEVEL VORTICITY MAXIMUM
WILL BREAK OFF AND STREAM EASTWARD EARLY THIS MORNING...AND BUFKIT
SOUNDINGS DO INDICATE THERMODYNAMIC INSTABILITY. NO SEVERE WEATHER
IS EXPECTED WITH THIS EARLY MORNING PRECIPITATION.
THE MAIN WEATHER THREAT WILL BE THIS AFTERNOON AS THE LATEST
SPC CONVECTIVE OUTLOOK INCLUDES SOUTHERN NORTH DAKOTA IN A SLIGHT
RISK FOR SEVERE.
UPDATE ISSUED AT 931 PM CDT FRI JUN 20 2014
ADJUSTED POPS TO REFLECT THE SHOWERS AND THUNDERSTORMS MOVING
THROUGH NORTHWEST AND NORTH CENTRAL NORTH DAKOTA. SHOWERS WILL
TAPER OFF BY 04 UTC FOLLOWING SUNSET. SKY COVER WAS ALSO
ADJUSTED/INCREASED IN AREAS OF POPS. OTHERWISE...NO CHANGES WERE
NEEDED.
UPDATE ISSUED AT 544 PM CDT FRI JUN 20 2014
DID EXTENDED THE ISOLATED TO SCATTERED MENTION OF SHOWERS AND
THUNDERSTORMS THROUGH 02 UTC FOR THE FAR NORTHWEST AND NORTH
CENTRAL GIVEN UPSTREAM RADAR TRENDS ACROSS NORTHEAST MONTANA AND
THE 20-21 UTC RAP/HRRR. OTHERWISE...NO OTHER CHANGES REQUIRED.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 320 PM CDT FRI JUN 20 2014
THE MAIN FORECAST CONCERN FOR THE PERIOD WILL BE THE SEVERE
THUNDERSTORM POTENTIAL SATURDAY AFTERNOON.
A VERTICALLY STACKED LOW CENTERED OVER SOUTHERN SASKATCHEWAN AND
MANITOBA WILL CONTINUE TO WOBBLE NORTH THIS AFTERNOON AND TONIGHT.
EVEN THOUGH INSTABILITY IS DEVELOPING OVER WESTERN AND CENTRAL
NORTH DAKOTA THIS AFTERNOON...LARGE SCALE SYNOPTIC SUBSIDENCE
(USING 700MB-300MB LAYER Q-VECTOR DIVERGENCE AS A PROXY) SHOULD
KEEP CONVECTION FROM GROWING UPSCALE. ISOLATED THUNDERSTORM
DEVELOPMENT WILL BE POSSIBLE ACROSS THE INTERNATIONAL BORDER THIS
AFTERNOON AND EARLY EVENING...BUT SHOULD BE SHORT-LIVED FOR THE
MOST PART. NO SEVERE WEATHER IS EXPECTED AT THIS TIME.
FOR TONIGHT...DRY BOUNDARY LAYER CONDITIONS COMBINED WITH WEAK
WINDS SHOULD ALLOW TEMPERATURES TO RADIATE TO NEAR NORMAL LOWS.
WINDS WILL BE THE WEAKEST IN THE BOUNDARY LAYER ACROSS
SOUTHWESTERN NORTH DAKOTA AROUND DAYBREAK. AS A RESULT...THINK
PATCHY FOG WILL DEVELOP MAINLY IN THE LOW-LYING AREAS OF
SOUTHWESTERN NORTH DAKOTA FROM 09Z-13Z SATURDAY.
FOR SATURDAY...THE SHORT RANGE MODELS PROG A SURFACE TROUGH TO
ENTER WESTERN NORTH DAKOTA IN THE MORNING...THEN SLOWLY MIGRATE
EAST INTO CENTRAL NORTH DAKOTA BY THE AFTERNOON. MUCAPE VALUES ARE
FORECAST TO RANGE BETWEEN 1000-1500 J/KG EAST OF A LINE FROM
BOWMAN TO DICKINSON...NORTHEAST TO MINOT AND BOTTINEAU BY THE
AFTERNOON WITH LITTLE TO NO CIN. FURTHERMORE...0-6 KM BULK SHEAR
VALUES AROUND 30 KNOTS ARE FORECAST TO DEVELOP OVER WESTERN AND
CENTRAL NORTH DAKOTA DURING THE AFTERNOON AS WELL. THINK
CONVECTION WILL HAVE NO PROBLEM INITIATING ALONG THE SURFACE
BOUNDARY BY MID-AFTERNOON...WITH GENERALLY AN EASTWARD PROPAGATION
THROUGH LATE AFTERNOON. GIVEN THE INSTABILITY/SHEAR PARAMETERS IN
PLACE...THINK SOME THUNDERSTORMS COULD BECOME SEVERE ACROSS SOUTH
CENTRAL NORTH DAKOTA BY LATE AFTERNOON. WILL MENTION THE SEVERE
THREAT IN THE HWO FOR NOW...WITH LATER SHIFTS POSSIBLY ADDING THE
SEVERE POTENTIAL IN THE ZONES.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 320 PM CDT FRI JUN 20 2014
SHOWERS / THUNDERSTORMS ALONG THE WEAK SURFACE TROUGH WILL
CONTINUE TO MOVE EAST SATURDAY NIGHT. THE MAIN RAIN CHANCES SHOULD
BE ACROSS THE EASTERN HALF OF THE FORECAST AREA...WITH THE
PRECIPITATION GRADUALLY ENDING FROM WEST TO EAST.
DRIER WEATHER IS IN STORE FOR SUNDAY...HOWEVER THE PROXIMITY OF THE
UPPER LOW COULD STILL BRING AN ISOLATED SHOWER OR THUNDERSTORM TO
FAR NORTHERN NORTH DAKOTA...ESPECIALLY DURING THE AFTERNOON. THE
UPPER LOW CONTINUES TO WEAKEN BY MONDAY...GRADUALLY BECOMING MORE OF
AN OPEN TROUGH THAT DROPS SOUTH INTO NORTH DAKOTA FROM SOUTHERN
CANADA. THE NAM AND GFS AGAIN SUGGEST THERE COULD BE A FEW SHOWERS
AND THUNDERSTORMS ACROSS NORTHERN NORTH DAKOTA...WHILE THE ECMWF
KEEPS THE RAIN CONFINED TO CANADA. WILL HOLD ONTO SLIGHT CHANCE
POPS IN THE SOUTH...WITH THE HIGHER CHANCES IN THE NORTH...CLOSER
TO THE BETTER UPPER LEVEL FORCING. THE UPPER TROUGH CONTINUES TO
SWING THROUGH THE NORTHERN PLAINS TUESDAY...BEFORE AN H5 RIDGE
BUILDS INTO THE AREA FOR MID-WEEK. FAST MOVING WAVES CONTINUE TO
WORK THEIR WAY THROUGH THE RIDGE...SO SMALL POPS PRODUCED FROM
THE ALL-BLEND MODEL CONSENSUS LOOK APPROPRIATE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1241 AM CDT SAT JUN 21 2014
AN AREA OF SHOWERS AND THUNDERSTORMS SHOULD FORM BEFORE SUNRISE
AND MOVE EASTWARD FROM KDIK TO KBIS AND KJMS. ANOTHER ROUND OF
STRONGER THUNDERSTORMS SHOULD FORM AROUND 21Z NEAR KBIS/KJMS.
KISN/KMOT SHOULD REMAIN DRY AND VFR.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SCHECK
SHORT TERM...TM
LONG TERM...CK
AVIATION...SCHECK
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
149 AM EDT SAT JUN 21 2014
.SYNOPSIS...
AN UPPER RIDGE WILL CONTINUE TO BREAK DOWN TODAY RESULTING IN
WEAKENING HIGH PRESSURE CURRENTLY IN PLACE OVER THE AREA. THIS
SHOULD YIELD A GREATER COVERAGE OF SHOWERS AND THUNDERSTORMS ACROSS
THE AREA THROUGH EARLY NEXT WEEK. A TYPICAL WARM SUMMERLIKE PATTERN
WILL CONTINUE THROUGH NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 145 AM EDT SATURDAY...REMNANTS OF TENNESSEE VALLEY MCS ARE
PUSHING INTO THE NORTHERN MTNS AT THIS TIME. HOWEVER...DUE TO WEAK
INSTABILITY NOT EXPECTING THESE SHOWERS AND THUNDERSTORMS TO SURVIVE
MUCH LONGER...ESPECIALLY ONCE INTERACTING WITH THE TERRAIN.
LIKEWISE...EARLIER SHOWER/THUNDERSTORM ACTIVITY ACROSS PORTIONS OF
THE I77 CORRIDOR HAS EXITED TO THE EAST...AND WEAKENED. THUS...POPS
WILL TAPER DOWN INTO THE REMAINDER OF THE MORNING ACROSS THE
PIEDMONT AS EXPECTED...WITH CHANCE POPS LINGERING ALONG THE SPINE OF
THE APPS. OTHERWISE...NO SIGNIFICANT CHANGES MADE TO THE EXTREME
NEAR TERM PORTION OF THE FORECAST. DID TWEAK TEMPS/DEWPOINTS/VISB
TO REFLECT LATEST OBSERVATIONS.
PREVIOUS DISCUSSION...
EVENING UPDATE...LATEST REGIONAL COMP REF SHOWS WEAKENING
CONVECTION IN AND AROUND THE CWFA...WHICH AGREES WELL WITH THE
DIFFUSE ENERGY FIELD ALOFT. THERE COULD BE SOME TSTMS AFFECTING THE
NRN MTNS OVERNIGHT ASSOCIATED WITH AN MCS SRN FLANK
OUTFLOW...HOWEVER NOT EXPECTING ANY MORE THAN A FEW LIGHTNING
STRIKES AND LOCALIZED GUSTY WINDS. SOME MTN VALLEY FG IS
POSSIBLE...BUT NOT TOO CERTAIN WITH THE AMOUNT OF DEBRIS CLOUDS
MOVING IN FROM THE NW. THE GOING POPS ARE IN GOOD SHAPE AND MADE
ONLY MINOR ADJS TO THE MIN TEMP GRID.
730 PM EDT UPDATE...A NICE LOBE OF VORT ENERGY HAS SPAWNED A LINE OF
STRONG TO SEVERE CONVECTION ACROSS THE NC MTNS AND FTHILLS THIS
EVENING. THE STEERING FLOW HAS INCREASED AS WELL AND STRENGTHENED
INFLOW CONVERGENT UPDRAFTS. ANTICIPATE A WEAKENING TREND AS THESE
STORMS MOVE OUT OF THE HIGHER TERRAIN INTO MORE STABLE AIR OVER THE
NEXT COUPLE HRS. HAVE RECEIVED A FEW REPORTS OF FUNNEL CLOUDS WHICH
ARE POSSIBLE WITH THE LVLV ROTATING UPDRAFTS. HOWEVER...A COUPLE
REPORTS HAVE INDICATED TORNADOES ON THE GROUND...WHICH ARE NOT
POSSIBLE IN THE CURRENT LOW SHEAR ENVIRONMENT. THESE REPORTS ARE
LIKELY SCUD CLOUDS AND/OR CLOUDS ASSOCIATED WITH STRONG RAINSHAFTS.
MADE MINOR TWEAKS TO THE T/TDS GRIDS DUE TO PRECIP OVER THE PAST 3
HRS.
430 PM EDT UPDATE...LOW SFC TD/S AND A NOTABLE LOBE OF DNVA HAS KEPT
CONVECTION MINIMAL AND RELATIVELY SHORT LIVED ACROSS CWFA THUS FAR
THIS AFTERNOON. THE STORMS TO THE EAST HAVE BEEN ABLE TO TAP INTO
HIGH VALUES OF DCAPE AND PRODUCE SEVERE WINDS...BUT THE REMAINING
CELLS HAVE HAD FAIRLY NARROW AND WEAKER UPDRAFTS. THE NAM12 HAS A
GOOD HANDLE ON THE UPPER VORT FIELD AND WILL FOLLOW IT/S GUIDANCE
WRT TO POPS AND CONVEC INITIATION OVER THE NEXT COUPLE HRS. THE
UPSTATE HAS THE LOWEST INSTABILITY COMBINED WITH NEGATIVE ULVL
FORCING...SO POPS WILL BE LOWERED TO ISOL THERE...ACROSS THE SRN NC
FTHILLS. THE BEST CHANCE FOR NEW DEVELOPMENT WILL BE ACROSS THE NC
MTN SPINE WHERE ENHANCED CONVECTION SHOULD MOVE IN AND LIKELY WEAKEN
THROUGH 8 PM.
AS OF 200 PM EDT...CELLS NOW LINING UP ALONG THE BLUE RIDGE AS A
WEAK RIPPLE ROUNDS THE RIDGE OVER THE LOWER MISSISSIPPI VALLEY AND
MOVES SEWD ACRS THE AREA. HRRR SEEMS TO HAVE PICKED UP ON THIS
ACTIVITY AND ALLOWS IT TO PROPAGATE SEWD SLIGHTLY BEFORE
DISSIPATING...POSSIBLY DUE TO DOWNSLOPING BY THE NW FLOW ABOVE THE
BOUNDARY LAYER. THE NCEP HIRES WINDOW /NMM/ SUGGESTS THE SAME...BUT
DEVELOPS A NEW ROUND OF CONVECTION IN THE MTNS BEHIND IT WHICH FILLS
IN THE SAME AREA. DEWPOINTS HAVE MIXED OUT SLIGHTLY AS
EXPECTED...BUT NOT ENOUGH TO KEEP SBCAPE FROM RISING TO 2000 J OR
MORE PER SPC MESOANALYSIS. NO SEVERE REPORTS HAVE YET BEEN RECEIVED
BUT A FEW STORMS HAVE MET WARNING CRITERIA. I AM NO LONGER CONFIDENT
IN OUR EARLIER EXPECTATIONS THAT WE WOULD NOT GET UNSTABLE ENOUGH
FOR LARGE HAIL TO BE MUCH OF A CONCERN...BUT PROFILES REMAIN DRY
ENOUGH FOR DCAPES OF 700-1000 J SUPPORTING A MICROBURST THREAT. CHC
RANGE POPS HAVE BEEN MAINTAINED ACRS MOST OF THE AREA...BUT NOW THE
GREATEST CHANCE APPEARS TO BE DOWNSTREAM OF THE CURRENT ACTIVITY.
SOME MODELS INCLUDING THE NAM TRY TO DEVELOP ANOTHER ROUND OF
CONVECTION AFTER SUNSET...BUT PROFILES HAVE ENOUGH CIN THAT I THINK
THIS IS UNLIKELY IN THE PRESENCE OF SUCH WEAK FORCING. POPS DIMINISH
EAST OF THE MTNS BY LATE EVENING.
MAIN FORECAST CHALLENGE FOR THE OVERNIGHT IS WHETHER ANY ACTIVITY
WILL MOVE INTO OUR AREA FROM THE WEST...AS SUGGESTED BY SOME OF THE
MESO GUIDANCE AND THE 12Z NAM. THE NAM SHOWS AN MCV DEVELOPING OVER
THE OHIO VALLEY LATE THIS AFTN AND PROGRESSING SEWD ACRS KY/TN...THE
ORIGINAL CONVECTION DYING BUT THE MCV KICKING OFF NEW DEVELOPMENT ON
THE WEST SLOPES OF THE MTNS WHICH THEN MOVES INTO NW NC AROUND
DAYBREAK. SO FAR THE NAM DEPICTION OF THE ORIGINATING CONVECTION
SEEMS OVERDONE...SO WILL ONLY GIVE THIS SMALL WEIGHT IN THE FCST.
CLOUD COVER PROGGED BY THE MODELS APPEARS MAINLY TO BE CONVECTIVE
DEBRIS AND IT IS A BIT HARDER TO HEDGE ON THAT.
THE NAM SUGGESTS DEEP RH WILL BE HIGHER ON SATURDAY...PROBABLY SINCE
IT EXPECTS DEBRIS TO COME IN DURING THE MORNING. GFS PROFILES REALLY
DO NOT LOOK TOO MUCH DIFFERENT FROM TODAY...THOUGH SBCAPE IS STILL
LOWER DUE TO SLIGHTLY WEAKER LAPSE RATES. THE DIFFERENCE IS NOT ONLY
IMPORTANT FOR THE POTENTIALLY SIGNIFICANT REDUCTION IN INSTABILITY
DUE TO CLOUDIER SKIES...BUT FOR A REDUCTION IN DCAPE AND MITIGATED
SEVERE RISK. SPC FEATURES A 5 PCT AREA JUST TO OUR EAST WHERE WEAK
SHORTWAVE /THE POTENTIAL MCV/ WILL PASS OVER DURING PEAK HEATING. IT
DOES APPEAR THE BEST PRECIP CHANCES OVERALL WILL BE DURING THE
MORNING IN THE NORTHERN FA AND THEN OVER THE I-77 CORRIDOR DURING
THE AFTN WHERE THE BEST BUOYANCY IS SUGGESTED. TEMPS TONIGHT AND
TOMORROW WILL REMAIN A CATEGORY OR SO ABOVE CLIMO.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY/...
AS OF 200 PM FRIDAY...HEIGHTS WILL GRADUALLY FALL THROUGH EARLY NEXT
WEEK...AS UPPER HIGH CONTINUES TO WEAKEN AND RETROGRADE TOWARDS
THE WESTERN GULF OF MEXICO. THIS WILL ALSO ALLOW WEAK FRONTAL ZONE
TO BACK DOOR ITS WAY THROUGH THE AREA BY SUNDAY...POSSIBLY
INTRODUCING SLIGHTLY COOLER AND DRIER AIR. THIS IS NOT EXPECTED TO
ELIMINATE INSTABILITY ENOUGH TO HALT DIURNAL CONVECTION...BUT
COVERAGE OF SUNDAY AFTERNOON/EVENING CONVECTION IS EXPECTED TO BE
MORE TYPICAL OF WHAT ONE WOULD EXPECT THIS TIME OF YEAR (30-40 POPS
MTNS...20/30 PIEDMONT).
BY MONDAY... SHORT TERM MODELS DEPICT ESTABLISHMENT OF AN E/SE FLOW
IN ASSOCIATION WITH A WEAK INVERTED RIDGE ALONG THE EASTERN
SEABOARD. THIS UPSLOPE FLOW COULD SUPPORT A BIT MORE IN THE WAY OF
DIURNAL CONVECTION BY MONDAY AFTERNOON...SO POPS RETURN TO ABOVE
CLIMO BY THIS TIME. WEAK SHEAR WITH HALFWAY DECENT STEERING FLOW
SHOULD PRECLUDE ANYTHING MORE THAN A TYPICAL EARLY SUMMER PULSE
SEVERE THREAT OR FLASH FLOODING THREAT SUNDAY. HOWEVER...HEAVY
RAINFALL MAY BECOME AN ISSUE MONDAY...AS UPPER FLOW WEAKENS ABOVE
THE LOW LEVEL SOUTHEAST FLOW...POSSIBLY FAVORING ANCHORING OF CELLS
ACROSS PORTIONS OF THE HIGH TERRAIN. TEMPS ARE EXPECTED TO RETURN TO
NEAR CLIMO BY MONDAY IN THE RELATIVELY COOL E/SE FLOW
REGIME.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 130 PM EDT FRIDAY...THE MEDIUM RANGE FCST PICKS UP AT 00Z ON
TUESDAY WITH WEAK UPPER RIDGING OVER THE SE CONUS AND A LOW
AMPLITUDE UPPER TROF DIGGING DOWN OVER OVER THE DAKOTAS AND
MINNESOTA. OVER THE NEXT FEW DAYS...THE TROF SLOWLY PROPAGATES
EASTWARD...YET IT DOES NOT APPEAR TO MAKE MUCH HEADWAY SOUTHWARD.
THE LONG RANGE MODELS HAVE BEEN DIFFERING A FAIR AMOUNT WRT THE
AMPLIFICATION OF THIS TROF...BUT ITS LOOKING LIKE THEY ARE LEANING
MORE TOWARDS STRONGER RIDGING OVER OUR FCST AREA THRU DAY 7. THIS PATTERN
LEAVES OUR AREA UNDER GENERALLY WEAK WEST TO SWLY STEERING FLOW THRU
THE PERIOD. AT THE SFC...THE REGION WILL BE UNDER THE INFLUENCE OF
THE BERMUDA HIGH FOR MOST OF THE PERIOD WITH A COLD FRONT
APPROACHING THE CAROLINAS BY EARLY WED AND WASHING OUT AS IT MOVES
OVER THE CWFA. IN ITS WAKE...WEAK CANADIAN HIGH PRESSURE TRIES TO
PUSH SOUTHWARD FROM NEW ENGLAND BUT ITS PROGRESS IS SUPPRESSED BY
THE BERMUDA HIGH. WITH THE COMBINATION OF SLY MOIST FLOW...A WEAKLY
SHEARED ENVIRONMENT AND MODERATE DIURNAL BUOYANCY...WE STILL HAVE A
SOLID CHANCE OF PULSE TYPE CONVECTION ACROSS MUCH OF THE REGION EACH
DAY...FAVORING IN THE MTN ZONES OVERALL. TEMPERATURES SHOULD REMAIN
FAIRLY STEADY WITH VALUES NEAR NORMAL OR POSSIBLE A FEW DEGREES
WARMER.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AT KCLT...VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD WITH
THE EXCEPTION OF POSSIBLE AFTERNOON MVFR TSRA. INITIALIZED TAF
UNDER SCT LOW VFR STRATUS WITH BKN MID LEVEL CIG THROUGH MID/LATE
MORNING WHERE STEEPENING LAPSE RATES ALLOW FOR DIURNAL CU
DEVELOPMENT. INTRODUCED LOW VFR CU CIG AT 19Z WITH A 4HR PROB30 FOR
AFTERNOON TSRA INCLUDING A 4SM VISB. SCT CIGS OUT AFTER
00Z...EVENTUALLY GIVING WAY TO HIGH LEVEL CIRRUS. WINDS WILL REMAIN
GENERALLY CALM OVERNIGHT BEFORE STARTING UP OUT OF THE WEST
NORTHWEST BY MID MORNING. LEE SIDE TROF WILL ONCE AGAIN VEER WINDS
FURTHER NORTH THROUGH THE REMAINDER OF THE PERIOD.
ELSEWHERE...MUCH THE SAME AS KCLT ABOVE AS VFR CONDITIONS WILL
PREVAIL WITH THE EXCEPTION OF POSSIBLE IFR/LIFR FOG RESTRICTIONS AT
KAVL...MVFR FOG RESTRICITONS AT KHKY...AND MVFR TSRA IN THE
AFTERNOON FOR EACH OF THESE TWO SITES. AREAS THAT RECEIVED
PRECIPITATION ON FRIDAY WILL LIKELY EXPERIENCE SOME LOWERING VISB
THROUGH MORNING AS THE BOUNDARY LAYER DECOUPLES AND TEMPERATURES
COOL UNDER SCT SKIES. ADDITIONALLY...MOIST PBL WILL ALLOW FOR
IFR/LIFR STRATUS IN AND AROUND THE MOUNTAIN VALLEYS.
OTHERWISE...CONVECTION ON SATURDAY WILL LIKELY REMAIN TIED TO THE
TERRAIN...AND THE NC PIEDMONT. THUS FEATURE PROB30S FOR MVFR TSRA
AT KAVL AND KHKY WHILE ONLY INCLUDING VCTS MENTION AT KGSP AND
KGMU...NOT EXPECTING ANY WX AT KAND. WINDS THROUGH THE PERIOD WILL
REMAIN NORTHERLY AND WILL INCREASE TO AROUND 8-10KTS WHEN MIXING IS
AT ITS GREATEST DURING PEAK HEATING.
OUTLOOK...ISOLATED TO SCATTERED AFTERNOON AND EVENING THUNDERSTORMS
ARE EXPECTED THIS WEEKEND...WITH THE GREATEST COVERAGE ACROSS THE
MTNS AND NC PIEDMONT. RESTRICTIONS MAY OCCUR DURING TSRA AND ALSO IN
THE MTN VALLEYS EACH MORNING WHERE LOW CLOUDS AND FOG MAY FORM OVER
AREAS OF RECENT RAINFALL.
CONFIDENCE TABLE...
05-11Z 11-17Z 17-23Z 23-05Z
KCLT HIGH 100% HIGH 100% HIGH 100% LOW 56%
KGSP HIGH 100% HIGH 100% HIGH 100% LOW 56%
KAVL HIGH 100% HIGH 99% HIGH 100% LOW 56%
KHKY HIGH 100% HIGH 100% HIGH 100% LOW 56%
KGMU HIGH 100% HIGH 100% HIGH 100% LOW 56%
KAND HIGH 100% HIGH 100% HIGH 100% LOW 56%
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...STAARMANN
NEAR TERM...CDG/SBK/WIMBERLEY
SHORT TERM...JDL
LONG TERM...JPT
AVIATION...CDG
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
344 AM CDT SAT JUN 21 2014
.DISCUSSION...
HELLO FOLKS....SUMMERTIME BEGINS THIS MORNING AT 551 AM...ENJOY!
AND NOW ON TO THE WEATHER.......
NW FLOW ALOFT IS IN PLACE AS THE UPPER HIGH NOW RESIDES OVER THE
NORTHERN GULF AND IS RATHER WEAK. IN THE LOWER LEVELS...WEAK HIGH
PRESSURE IS IN CONTROL. LOW LEVEL FLOW WILL GRAVITATE TOWARD A DRIER
NORTHERLY FLOW BY AFTERNOON. CONVECTIVE CHARTS SHOW THE BETTER CAP
EROSION ACROSS THE SOUTH WITH APPRECIABLE CAPE THERE AS WELL. THE
PLAN FOR TODAY WILL BE TO CARRY A SLIGHT CHANCE OF SHOWERS AND TSTMS
NORTH IN THE MORNING. ELSEWHERE...WILL CARRY THE LOW POPS THROUGH
THE DAY. HRRR SHOWING SOME DEVELOPMENT BY 17Z OR SO. OTW...THE DRIER
AIR WILL WIN OUT TOWARD EVENING. FOR TONIGHT AND SUNDAY...LITTLE
OR NO POPS WILL BE INCLUDED. PCLDY TO MOSTLY CLEAR SKIES ARE
EXPECTED FOR SUNDAY INTO SUNDAY NT. THE NEXT CHANCE OF SHOWERS AND
TSTMS WILL BE ON MONDAY. AT THAT TIME...LOW LEVEL FLOW WILL BECOME
MORE SOUTHERLY AND BRING A RETURN OF MOISTURE AND MORE FAVORABLE
CONVECTIVE PARAMETERS. RAIN CHANCES FOR SUNDAY WILL STILL BE ON
THE LOW SIDE AS THE BETTER DYNAMICS RESIDE TO OUR NW.
AS FOR THE NEAR TERM TEMPS...STILL LOOKING AT ABOVE NORMAL VALUES.
HOWEVER...OVERNIGHT LOWS THE NEXT FEW OVERNIGHTS WILL DROP INTO THE
MID TO UPPER 60S AS THE SOMEWHAT DRIER AIR PREVAILS. VERSUS THE
GUIDANCE...VERY LITTLE DEVIATION THIS ROUND.
IN THE EXT FCST...THE GFS SHOWS A NICELY STACKED STORM SYSTEM ON
APPROACH FOR TUESDAY. EURO SOLUTION IS ABOUT 24 HOURS LATER. SFC LOW
LOOKS AS THOUGH IT WILL TRACK ACROSS NORTHERN MIDDLE TN ON WED
AFTERNOON. AT THAT TIME...CAPE VALUES LOOK UNIMPRESSIVE AND THE
SYSTEM APPEARS TO BE MORE OF A RAINFALL EVENT. CAPES ARE HIGHER TO
OUR SOUTH WHERE THE BETTER MID LEVEL JET RESIDES. AT ANY
RATE...CANNOT RULE OUT AN INCH OR SO OF RAINFALL FOR TUESDAY THROUGH
WEDNESDAY.
FOLLOWING THE EXIT OF THE MID WEEK STORM SYSTEM. WEAK RIDGING WILL
ATTEMPT TO REESTABLISH ITSELF. HOWEVER...BOTH THE RESIDUAL AND
SOUTHERLY FLOW INDUCED MOISTURE WILL UNDERCUT ANY RIDGING THAT
DEVELOPS AND CONTINUE TO PROVIDE LOW CHANCES OF SHOWERS AND TSTMS
FOR THU AND FRI.
FOR THE EXT TEMPS...VALUES WILL CONTINUE TO RUN A FEW DEGREES ABOVE
NORMAL. A SLIGHT UNDERCUT ON MAX TEMPS WILL BE UTILIZED AS 850 MB
TEMPS ARE KEPT WITHIN THE 16C TO 18C RANGE AND A LITTLE MORE IN THE
WAY OF CLOUDINESS WILL EXIST.
&&
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 91 68 93 69 / 20 10 10 10
CLARKSVILLE 91 66 93 67 / 10 10 10 10
CROSSVILLE 84 64 87 63 / 20 10 10 10
COLUMBIA 92 68 93 70 / 20 10 10 10
LAWRENCEBURG 92 67 92 69 / 20 10 10 10
WAVERLY 91 66 93 68 / 20 10 10 10
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
21
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
339 AM CDT SAT JUN 21 2014
.SHORT TERM...
TODAY AND TONIGHT...FORECAST CONFIDENCE IS MEDIUM.
WE HAVE A RATHER COMPLICATED FORECAST FOR TODAY AND TONIGHT. FOR
STARTERS...A LARGE AREA OF LOW STRATUS/FOG AND COOL AIR HAS
OVERSPREAD THE AREA FROM AN EASTERLY FLOW OFF LAKE MICHIGAN. THE
EXACT DISSIPATION OF THIS DECK IS ALWAYS TRICKY AND WILL LIKELY
IMPACT THE AIRSHOW SCHEDULED FOR THE LAKE SHORE OF MILWAUKEE TODAY.
A DENSE FOG ADVISORY IS IN EFFECT FOR THE LAKE SHORE COUNTIES
THROUGH 9 AM. IN GENERAL...VISIBILITIES ARE BETTER THAN 1/2
MILE...BUT AREA WEB CAMS SHOW SOME SPOTTY DENSE FOG...ESPECIALLY
RIGHT ALONG THE LAKE. SO IT/S PRUDENT TO KEEP THIS GOING THROUGH MID
MORNING.
THE WESTERN EDGE OF THE STRATUS DECK...WEST OF MADISON EARLY THIS
MORNING...IS DEFINING A STATIONARY FRONTAL BOUNDARY THAT EXTENDS UP
TO A SURFACE LOW OVER EASTERN MINNESOTA. MEANWHILE...MANY OF THE
MODELS ARE FIRING OFF SOME ELEVATED CONVECTION THAT PUSHES ACROSS
THE CWA THIS MORNING. THIS IS IN ASSOCIATION WITH AN H7 TROF AND
RIGHT ENTRANCE REGION OF A DEPARTING UPPER JET. AT THIS
WRITING...THAT CONVECTION HASN/T STARTED YET AND CONFIDENCE ISN/T
HIGH THAT IT WILL. SO SMALL POPS WILL COVER THAT FOR NOW AND WILL
ADJUST IF IT STARTS TO SHOW ITS HAND...OR NOT. NOTHING WILL BE
SURFACE BASED DUE TO THE RATHER DEEP CAPPING FROM THE COOLER FLOW
OFF THE LAKE.
FOR THIS AFTERNOON...THE MODEL SOUNDINGS SUGGEST THE STRATUS AND
IT/S SUPPORTIVE LOW LEVEL INVERSION WILL MIX OUT BY AROUND NOON. THE
SOUNDINGS SHOW UNCAPPED CAPE OF ABOUT 1500J/KG AVAILABLE THIS
AFTERNOON AND WITH THE WEAK FRONTAL BOUNDARY STILL LINGERING...WE
COULD SEE A FEW THUNDERSTORMS DEVELOP. DEEP LAYER BULK SHEAR IS ON
THE WEAK SIDE...GENERALLY LESS THAN 30KTS...WITH PARAMETERS LOOKING
BETTER TO THE SOUTH. IF WE GET DECENT DIFFERENTIAL HEATING ALONG
THE EDGE OF THE STATUS...WE COULD SEE A STRONGER SURFACE BOUNDARY
AND LLV CONVERGENCE. SPC HAS CLIPPED OUR FAR SOUTH WITH A SLIGHT
RISK FOR SVR STORMS. ALTHOUGH IT APPEARS THE BEST CHANCE FOR THE
STRONGEST STORMS WILL BE TO OUR SOUTH...THE HIRES ARW AND NMM MODELS
BOTH SHOW SOMETHING ROLLING EAST ALONG THE STATE LINE.
LOTS OF UNCERTAINTY WITH OVERALL WEAK FORCING WITHIN A MODERATELY
UNSTABLE AIRMASS. THE COLDER LOW LEVEL STRATUS JUST COMPLICATES
THINGS. SO WILL KEEP POPS ON THE LOWER SIDE WHICH MATCHES THE
CONSENSUS OF THE MODELS AND THINKING OF SURROUNDING OFFICES.
A BACKDOOR COLD FRONT IS EXPECTED TO DROP THROUGH THE AREA THIS
EVENING IN THE WAKE OF A LOW PRESSURE SYSTEM SCOOTING EAST. THIS
SHOULD SET THE STAGE FOR MORE FOG AND POSSIBLE LOW CLOUDS.
&&
.AVIATION/12Z TAFS/...
A VERY DIFFICULT FORECAST INDEED. THE COOL EASTERLY FLOW OFF THE
LAKE HAS COMBINED WITH THE MOIST AIRMASS IN PLACE THE LAST FEW
DAYS...RESULTING IN A HUGE LOWER STRATUS DECK THAT COVERS MUCH OF
ERN WISCONSIN AND NRN IL. IT/S CONSISTENTLY 200-300 AGL ACROSS THE
AREA. THE LATEST AMDAR AIRCRAFT AND RAP SOUNDING SHOW THIS TO BE
ABOUT 2-2.5KFT THICK. THE RAP MIXES IT OUT IN THE MILWAUKEE AREA BY
AROUND 17-18Z THIS AFTERNOON...SO IT SHOULD HANG IN TIGHT THROUGH
THE MORNING. THE EROSION AT KMSN IS AROUND 15Z. ONCE IT STARTS TO
OPEN UP...IT WILL LIKELY LIFT INTO TO STRATOCU DECK BEFORE
SCATTERING OUT. THE FOG/LOWER VSBYS SHOULD IMPROVE AFTER
SUNRISE...AS WE START TO HEAT THINGS UP AND PUT A LITTLE DISTANCE
BETWEEN THE TEMP AND DEWPOINT.
THEN WE HAVE THE CHANCE FOR SHOWERS AND THUNDERSTORMS. THE BEST
CHANCE FOR ANY STORMS LOOKS TO BE FROM ABOUT 20Z-01Z...OR
TRADITIONAL PEAK HEATING. THERE WILL BE A WEAK FRONTAL BOUNDARY IN
THE AREA THAT MAY ACT AS A FOCUS FOR THUNDERSTORM DEVELOPMENT. WE
WILL BE IN A WEAK FLOW...MODERATELY UNSTABLE ENVIRONMENT THIS
AFTERNOON...SO THERE IS PLENTY OF UNCERTAINTY.
MORE FOG IS EXPECTED TONIGHT AS A BACKDOOR COLD FRONT SWEEPS DOWN
THE LAKE AS WEAK LOW PRESSURE SCOOTS EAST. OF COURSE THIS MEANS MORE
FOG AND POSSIBLY LOWER STRATUS AGAIN TONIGHT.
.LONG TERM...
SUNDAY THROUGH TUESDAY NIGHT...FORECAST CONFIDENCE MEDIUM.
THERE IS A CHANCE FOR SHOWERS AND THUNDERSTORMS DURING THE DAY
SUNDAY WITH WEAK 850MB FRONTOGENESIS AND 700 MB UPWARD MOTION.
FORECAST SOUNDINGS FOR MADISON SHOW BUILDING CAPE THROUGH THE
AFTERNOON WITH NO CAP. HOWEVER...LOW POPS BECAUSE WE MIGHT LACK A
TRIGGER FOR ANY THUNDERSTORMS TO DEVELOP DUE TO MID LEVEL RIDGING
OVERHEAD. IF THUNDERSTORMS DEVELOP...THE SHEAR IS WEAK SO NOT
LOOKING FOR SEVERE STORMS DURING THE DAY.
NEAR THE LAKE...WINDS WILL CONTINUE TO BE LIGHT AND EASTERLY ON
SUNDAY. THIS SHOULD CONTINUE THE FOG AND STRATUS OVER THE NEARSHORE
WATERS THROUGH AT LEAST EARLY AFTERNOON.
THE BETTER CHANCE FOR THUNDERSTORMS WILL COME LATER SUNDAY
NIGHT THROUGH TUE NIGHT AS A MID LEVEL SHORTWAVE VERY SLOWLY TRACKS
THROUGH MN AND WI. THE LOW LEVEL JET WILL POINT INTO SOUTHERN WI
LATE SUNDAY NIGHT INTO MONDAY MORNING...WHICH WILL ALSO BE
COINCIDENT WITH THE HIGH PRECIPITABLE WATER VALUES.
BY MONDAY AND MONDAY NIGHT...THE MID LEVEL TROUGH WILL BE MOVING
OVERHEAD ALONG WITH A SURFACE LOW PRESSURE TROUGH. RAIN AND
THUNDERSTORMS ARE MOST LIKELY DURING THIS PERIOD.
TUESDAY THROUGH FRIDAY...FORECAST CONFIDENCE MEDIUM.
SURFACE HIGH PRESSURE WILL SETTLE OVER LAKE SUPERIOR LATER NEXT
WEEK. ZONAL MID LEVEL FLOW AND AN 850MB FRONT STATIONED APPROX OVER
SOUTHWEST WI WILL ALLOW FOR MORE SHOWER AND ISOLATED THUNDERSTORM
DEVELOPMENT...ESPECIALLY IN SOUTH CENTRAL WI INLAND FROM THE LAKE.
BEST CHANCE FOR PRECIP WILL BE EACH AFTERNOON. THERE ARE STILL
TIMING AND COVERAGE DIFFERENCES BETWEEN THE MODELS. STAY TUNED.
EASTERLY WINDS WILL KEEP LAKESHORE TEMPS COOLER. INLAND TEMPS ARE
EXPECTED IN THE UPPER 70S.
&&
.AVIATION/12Z TAFS/...
A VERY DIFFICULT FORECAST INDEED. THE COOL EASTERLY FLOW OFF THE
LAKE HAS COMBINED WITH THE MOIST AIRMASS IN PLACE THE LAST FEW
DAYS...RESULTING IN A HUGE LOWER STRATUS DECK THAT COVERS MUCH OF
ERN WISCONSIN AND NRN IL. IT/S CONSISTENTLY 200-300 AGL ACROSS THE
AREA. THE LATEST AMDAR AIRCRAFT AND RAP SOUNDING SHOW THIS TO BE
ABOUT 2-2.5KFT THICK. THE RAP MIXES IT OUT IN THE MILWAUKEE AREA BY
AROUND 17-18Z THIS AFTERNOON...SO IT SHOULD HANG IN TIGHT THROUGH
THE MORNING. THE EROSION AT KMSN IS AROUND 15Z. ONCE IT STARTS TO
OPEN UP...IT WILL LIKELY LIFT INTO TO STRATOCU DECK BEFORE
SCATTERING OUT. THE FOG/LOWER VSBYS SHOULD IMPROVE AFTER
SUNRISE...AS WE START TO HEAT THINGS UP AND PUT A LITTLE DISTANCE
BETWEEN THE TEMP AND DEWPOINT.
THEN WE HAVE THE CHANCE FOR SHOWERS AND THUNDERSTORMS. THE BEST
CHANCE FOR ANY STORMS LOOKS TO BE FROM ABOUT 20Z-01Z...OR
TRADITIONAL PEAK HEATING. THERE WILL BE A WEAK FRONTAL BOUNDARY IN
THE AREA THAT MAY ACT AS A FOCUS FOR THUNDERSTORM DEVELOPMENT. WE
WILL BE IN A WEAK FLOW...MODERATELY UNSTABLE ENVIRONMENT THIS
AFTERNOON...SO THERE IS PLENTY OF UNCERTAINTY.
MORE FOG IS EXPECTED TONIGHT AS A BACKDOOR COLD FRONT SWEEPS DOWN
THE LAKE AS WEAK LOW PRESSURE SCOOTS EAST. OF COURSE THIS MEANS MORE
FOG AND POSSIBLY LOWER STRATUS AGAIN TONIGHT.
&&
.MARINE...
DENSE FOG IS EXPECTED THROUGH ABOUT MID MORNING. THE NEARSHORE AREAS
MAY REMAIN IN A LIGHT FOG THROUGH THE DAY WITH MORE DENSE FOG
POSSIBLE TONIGHT AS A COLD FRONT MOVES SOUTH DOWN THE LAKE SHORE.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...DENSE FOG ADVISORY UNTIL 9 AM CDT THIS MORNING FOR WIZ052-060-
066-071-072.
LM...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR LMZ643>646.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...DAVIS
SUNDAY THROUGH FRIDAY...MRC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1149 PM CDT FRI JUN 20 2014
.UPDATE...
ISSUED AT 958 PM CDT FRI JUN 20 2014
FOR NO WEATHER IN THE FORECAST AREA...THERE SURE IS SOME ACTION
AROUND US IN EVERY DIRECTION.
TO THE EAST...HAVE ADJUSTED FORECAST FOR THE WESTWARD MOVING FRONT
WHICH IS MARKED BY LOW CLOUD AND SOME NEAR 1 MILE VISIBILITIES. I
KNOW THE SOLSTICE IS AROUND SUNRISE...BUT THAT IS TOO MUCH OF A
WINTER LOOK TOO SOON. EASTERLY FLOW IS MAXIMIZING NOW THROUGH JUST
AFTER MIDNIGHT AND SHOULD BEGIN TO VEER TOWARD SE-S LATER AS
LOW PRESSURE APPROACHES WI. HAVE BROUGHT CLOUDS TO ABOUT KEAU-KDLL
LINE AND LOWERED TEMPERATURES AND DEWPOINTS OVERNIGHT. HAVE NOT
ADDED FOG YET BUT MAY NEED TO IF VSBYS ARE GOING TO GO LESS THAN 1
MILE.
TO THE SOUTHWEST...CONVECTION IS STAYING BEHAVED AND FEEDING OFF
LOW-LEVEL MOISTURE CONVERGENCE INTO SOUTHERN IA PER RAP MODEL
GUIDANCE. THIS TREND SHOULD CONTINUE. HOWEVER...MOISTURE IN LOW-
LEVELS IS DOING AN END-AROUND WITH W-SWRLY 850-925MB FLOW ACROSS
NRN IA AND SRN MN EASTWARD...WHICH WILL INCREASE THE LOW-LEVEL
DEWPOINTS BY 4C OR SO WITH TROUGH MOVING THROUGH...WARM FRONTAL.
ALTHOUGH RAP FORECASTS SEEM TO INDICATE T/TD ARE STILL SOME 3C
FROM LOW-LEVEL SATURATION...THERE IS SOME CONVERGENCE AND
ELEVATED CAPE SHOULD SATURATION OCCUR IN THAT LAYER...WITH NO CAP.
SO...OVERNIGHT THERE IS A CHANCE FOR A POP-UP SHOWER OR STORM IN
THE 06-12Z TIME FRAME. SOME HI-RES CONVECTIVE ALLOWING MODELS
SUGGEST THIS WITH SOME ECHO SHOWING UP IN WI. SMALL RAIN CHANCES
ARE IN FOR THAT POSSIBILITY /20-30/.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 344 PM CDT FRI JUN 20 2014
AT 3 PM...TWO BOUNDARIES WERE LOCATED ACROSS THE FORECAST AREA.
THE FIRST OF THESE TWO EXTENDS FROM NEW RICHMOND /KRNH/ TO
LA CROSSE WISCONSIN. BOTH THE RAP AND LAPS DATA SHOW 150 TO
200 J/KG OF SURFACE TO 3 KM CAPE...STRONG LAYER ENHANCED
STRETCHING POTENTIAL...STEEP 0-2 KM LAPSE RATES /GREATER THAN
9 C/KM /...AND WEAK TO MODERATE SURFACE RELATIVE VORTICITY. THIS
WOULD BE SUPPORTIVE OF NON-SUPERCELL TORNADOES. THESE CONDITIONS
CONTINUE THROUGH 21.02Z. HOWEVER AT THIS TIME...IT LOOKS LIKE THE
CONVERGENCE WILL NOT BE GREAT ENOUGH FOR THEIR DEVELOPMENT.
A SECOND BOUNDARY LOOKS TO BE EITHER A DRY LINE OR A DIFFERENTIAL
HEATING BOUNDARY ACROSS CENTRAL WISCONSIN. THERE WAS A BRIEF
SHOWER AT WAUSAU. JUST LIKE THE PREVIOUS BOUNDARY...THE
CONVERGENCE IS NOT THAT STRONG ALONG THE BOUNDARY. WITH 2 TO 3K
SURFACE BASED CAPES...WILL HAVE TO MONITOR THIS AREA FOR
DEVELOPMENT.
FURTHER NORTHWEST...A SHORT WAVE TROUGH WAS MOVING ACROSS NORTHERN
MINNESOTA. THIS SYSTEM WAS MOVING THROUGH AN AREA OF 1K SURFACE
CAPES. THIS HAS RESULTED IN THE DEVELOPMENT OF SHOWERS AND STORMS.
WITH THE RAP SHOWING EFFECTIVE SHEAR GREATER THAN 40 KNOTS...AREAS
NORTH OF INTERSTATE 94 WILL HAVE TO BE MONITORED FOR THE POTENTIAL
OF SEVERE WEATHER. THERE IS A BOUNDARY NORTH OF PHILLIPS
WISCONSIN. THIS COULD AID IN THE DEVELOPMENT OF A FEW TORNADOES.
MEANWHILE FURTHER SOUTH...THE THREATS WILL BE LARGE HAIL AND
DAMAGING WINDS. THIS MAY AFFECT CLARK AND TAYLOR COUNTIES LATE
THIS AFTERNOON AND EVENING...BUT THIS IS HIGHLY DEPENDENT ON
WHETHER STORMS CAN EVEN DEVELOP. MANY OF THE MESO MODELS SUGGEST
THAT THIS WILL NOT BE THE CASE.
FINALLY...AN AREA OF SHOWERS AND STORMS ARE DEVELOPING AHEAD OF A
SHORT WAVE TROUGH MOVING OUT OF CENTRAL NEBRASKA. A FEW OF THESE
STORMS HAVE ALREADY BECOME SEVERE. THE GFS...ECMWF...AND ARW
SUGGEST THAT THESE SUPERCELLS WILL DEVELOP INTO A MESOSCALE
CONVECTIVE COMPLEX WHICH WILL MOVE THROUGH OUR AREAS ALONG AND
SOUTH OF INTERSTATE 90 BETWEEN 21.06Z AND 21.15Z. AT THIS
TIME...IT LOOKS LIKE THE 0-3 KM AND 0-6 KM SHEAR WILL BE TOO WEAK
FOR ANY SEVERE WEATHER WITH THIS COMPLEX. ONE THING THAT WILL HAVE
TO WATCHED IS THAT THE HOP WRF AND HRRR SUGGEST THAT THIS COMPLEX
MAY DIVE SOUTHEAST TOWARD THE BETTER INSTABILITY ACROSS
MISSOURI...SO WILL HAVE TO WATCH THIS CLOSELY LATE TONIGHT.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 344 PM CDT FRI JUN 20 2014
THIS PART OF THE FORECAST IS GREATLY COMPLICATED DUE TO ZONAL FLOW
ALOFT. THE EXTENDED MODELS ARE SHOWING VARYING TIMES AND
STRENGTHS OF SHORT WAVES EMBEDDED IN THIS FLOW. OVERALL...THE BEST
CHANCE OF SHOWERS AND THUNDERSTORMS LOOKS TO BE FROM SUNDAY NIGHT
THROUGH MONDAY AS A SHORT WAVE TROUGH MOVES THROUGH THE CENTRAL
PLAINS AND MID MISSISSIPPI RIVER VALLEY...AND FROM TUESDAY THROUGH
WEDNESDAY AS A CANADIAN COLD FRONT DROPS INTO THE AREA. THIS FRONT
WILL LIKELY INCREASE THE SHEAR ACROSS THE AREA FOR THE POTENTIAL
OF SEVERE WEATHER. HOWEVER THERE ARE UNCERTAINTIES ON HOW FAR
SOUTH THIS FRONT WILL GET DUE TO THE ZONAL FLOW. AS A
RESULT...STAYED CLOSE TO THE MODEL CONSENSUS FOR NOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1150 PM CDT FRI JUN 20 2014
THUNDERSTORM ACTIVITY OVER IOWA WILL KEEP A STEADY FLOW OF THICK
CIRRUS OVERHEAD. A WEAK FLOW PATTERN OVERHEAD WITH LITTLE FOCUS OF
LIFT NEAR THE TAF SITES MEANS A VFR FORECAST. THERE IS A VERY
SMALL CHANCE OF ISOLATED SHOWER OR TSRA OVERNIGHT BUT NOT A LARGE
ENOUGH CHANCE TO INCLUDE IN THE FORECAST.
IT APPEARS THE THICK OVERCAST WILL LIMIT COOLING BUT WITH ONLY 6F
REMAINING TO COOL AT KLSE...DECIDED TO LEAVE THE 5SM BR IN THE
FORECAST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...BAUMGARDT
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...BAUMGARDT
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1042 PM MDT FRI JUN 20 2014
.UPDATE...
ISSUED AT 931 PM MDT FRI JUN 20 2014
GRIDDED FORECASTS IN DECENT SHAPE FOR TONIGHT...AND HAVE MADE ONLY
SOME MINOR CHANGES TO ACCOUNT FOR TRENDS AND THE PROGS OF THE 00Z
MODEL GUIDANCE.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 345 PM MDT FRI JUN 20 2014
PRETTY QUIET AFTN WITH A DRY AIRMASS ACROSS THE CWA. CUMULUS
DEVELOPMENT HAS LARGELY BEEN CONFINED TO NORTHEASTERN COLORADO AND
STRETCHING NORTHEAST INTO CENTRAL NEBRASKA WHERE DEWPOINTS ARE IN
THE UPPER 50S. MODELS DO NOT SHOW MOISTURE ADVECTING WESTWARD
THROUGH THE EVENING...SO STORM CHANCES WILL BE QUITE SLIM. TEMPS ARE
WARM THIS AFTN WITH THE CLEAR SKIES AND 700MB TEMPS AROUND 12C. ZONAL
FLOW ALOFT WILL CONTINUE THROUGH MUCH OF THE WEEKEND. A SFC
TROUGH WILL BE LOCATED ACROSS THE WESTERN NEBRASKA PANHANDLE ON
SATURDAY AFTN. CONVERGENCE ALONG THE TROUGH WILL CAUSE TSTMS TO
DEVELOP BY THE AFTN WITH GOOD INSTABILITY TO THE EAST (LI VALUES
OF -4C). THERE IS SOME DISAGREEMENT BETWEEN THE GFS AND NAM ON THE
LOCATION OF THE BOUNDARY. THE FURTHER EAST GFS SOLN WOULD KEEP
THE BEST STORM CHANCES TO THE EAST OF THE CWA WHEREAS THE NAM SHOWS
HIGHER DEWPOINTS/GOOD INSTABILITY WELL WESTWARD TO THE WY-NE
BORDER. THE SPC HAS MUCH OF THE PANHANDLE IN A SLIGHT RISK FOR SVR
STORMS TOMORROW. DEEP LAYER SHEAR IS MARGINAL AT AROUND 30-35 KTS
SO NOT CONFIDENT THAT WE WILL SEE A WIDESPREAD SVR EVENT.
A WEAK SHORTWAVE WILL PUSH TO THE NORTH OF THE CWA ON SUNDAY THAT
WILL CAUSE A COLD FRONT TO MOVE OVER THE PLAINS DURING THE
MORNING. WILL SEE ABOUT A 10 DEGREE COOL DOWN ON SUNDAY BEHIND THE
FRONT. BOTH THE GFS AND NAM INDICATE GOOD INSTABILITY ON SUN AFTN
OVER THE PLAINS WITH LI VALUES OF -3C TO -5C. SOUTHEAST WY WILL
SEE A MUCH BETTER CHANCE OF STORMS ON SUNDAY AFTN WITH THE
INCREASED LLVL MOISTURE AND UPSLOPE SFC WINDS. CAN NOT RULE OUT
STRONGER STORMS ON SUNDAY ALSO WITH BULK SHEAR AT AROUND 35 KTS.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 345 PM MDT FRI JUN 20 2014
A SEASONALLY ACTIVE PERIOD SHAPING UP AS A SERIES OF SHORTWAVES
EMBEDDED WITHIN QUASI-ZONAL FLOW PUSH THRU THE CWA. EACH SHORTWAVE
IS IMPOSSIBLE TO TIME AT THIS TEMPORAL RANGE. SFC BOUNDARY WILL
BEGIN THE PERIOD NR THE DIVIDE WITH A SHORTWAVE TRAVERSING EAST.
INSTABILITY POOLING IN THE VICINITY OF THE BOUNDARY WILL CONTRIBUTE
TO LINGERING CONVECTION SUNDAY NIGHT. WEST/NORTHWEST FLOW WILL ENSUE
MON/TUE AS UPSTREAM RIDGE TRIES TO DEVELOP AHEAD OF A TROUGH OVR THE
PACNW. INSTABILITY REMAINS WITH PROGD SBCAPES OF 1000-1500 J/KG EACH
DAY. DEEP LAYER SHEAR OF 35-50 KNOTS SUGGEST THE POTENTIAL FOR A FEW
STORMS TO BECOME STRONG TO LOCALLY SEVERE BOTH DAYS. SO...KEPT IN
CHANCES OF THUNDERSTORMS GOING WITH THE BEST COVERAGE FOR AREAS
ALONG AND EAST OF THE LARAMIE RANGE. THE GFS IS MORE AGGRESSIVE IN
AMPLIFYING THE RIDGE FOR THE LATTER HALF OF THE UPCOMING WEEK. IN
THIS SCENARIO...CONVECTIVE CHANCES WOULD BE LESSER. THE ECMWF IS
LESS AMPLIFIED...OFFERING A BETTER CHANCE OF THE TYPICAL ACTIVE
AFTERNOON AND EVENINGS. SUSPECT THE ANSWER IS SOMEWHERE IN BETWEEN
AND FOR NOW HAVE LESSENED COVERAGE FOR WEDNESDAY AND KEPT CONDITIONS
DRY FOR THU/FRI. AS FOR TEMPERATURES...MONDAY WILL BE THE COOLEST
DAY OF THE WEEK AS HIGHS REACH THE 70S. TEMPERATURES CLIMB BACK INTO
THE 80S AT MOST LOCATIONS WED-FRI.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY EVENING)
ISSUED AT 1037 PM MDT FRI JUN 20 2014
LOW LEVEL MOISTURE BEGINNING TO MAKE ITS WAY INTO THE SOUTHERN
PANHANDLE THIS EVENING. IN FACT...THE LATEST HRRR GUIDANCE SHOWING
IFR CONDITIONS HERE AT KCYS AFTER 08Z. NOT TOO SURE OF THAT
HAPPENING AS WE ARE STILL PRETTY DRY...RH OF 48 PERCENT AT
1030PM...SO DID NOT FOLLOW THIS GUIDANCE. LOOK FOR LOW LEVEL
MOISTURE TO CONTINUE INCREASING OVERNIGHT...SETTING THE STAGE FOR
SHOWERS AND TSTMS SATURDAY AFTERNOON EAST OF THE LARAMIE RANGE.
COLD FRONT STILL FORECAST TO MOVE TO THE EAST SLOPES OF THE
LARAMIE RANGE LATE SATURDAY NIGHT WITH UPSLOPING WINDS EAST OF THE
FRONT. WOULD EXPECT THIS TIME FRAME TO BE THE BETTER CHANCE FOR
MORE WIDESPREAD MVFR/IFR CONDITIONS. SO...TRENDED THE TAFS THAT
WAY WITH LOWERING CLOUDS LATE IN THE 06Z TAF CYCLE.
&&
.FIRE WEATHER...
ISSUED AT 345 PM MDT FRI JUN 20 2014
MINIMAL FIRE WEATHER CONCERNS THROUGH THE WEEKEND. AFTERNOON
HUMIDITY VALUES WILL DROP TO AROUND 15 PERCENT FOR AREAS ALONG AND
WEST OF THE LARAMIE RANGE THIS AFTERNOON AND ON SATURDAY. WEST TO
SOUTHWEST WINDS WILL OCCASIONALLY GUST TO 25 MPH BOTH AFTERNOONS.
HOWEVER...NO CRITICAL FIRE WEATHER THREAT IS ANTICIPATED SINCE
FUELS HAVE STILL NOT CURED ENOUGH TO SUPPORT FIRE GROWTH. COOLER
TEMPERATURES WILL OCCUR ON SUNDAY AND INTO EARLY NEXT WEEK ALONG
WITH A BETTER CHANCE OF WETTING RAINS...ESPECIALLY TO THE EAST OF
THE LARAMIE RANGE.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...RUBIN
SHORT TERM...FINCH
LONG TERM...HAHN
AVIATION...CLAYCOMB
FIRE WEATHER...FINCH
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1036 AM CDT SAT JUN 21 2014
.MESOSCALE DISCUSSION...
1029 AM CDT
CONVECTIVE POTENTIAL FOR EARLY TO MID AFTERNOON TODAY WITH A
THREAT REMAINING FOR STRONG TO SEVERE WEATHER...PRIMARILY A HIGH
WIND THREAT...ACROSS NORTH CENTRAL ILLINOIS AND POSSIBLY NORTHWEST
INDIANA.
CURRENT RADAR IMAGERY DEPICTING ISOLATED SHOWER ACTIVITY ACROSS
NORTH CENTRAL AND NORTHEAST ILLINOIS SLIDING EAST OUT AHEAD OF
WEAKENING WAA WING STRETCHING SOUTH THROUGH THE AREA. DONT
ANTICIPATE ANY FURTHER DEVELOPMENT WITH THESE SHOWERS THIS MORNING
WITH THE CURRENT ISOLATED COVERAGE REMAINING THE SAME NOR DO I
EXPECT MUCH IN TERMS OF ANY THUNDER OUTSIDE OF A FEW RUMBLES OF
THUNDER...AS THIS PRECIP IS BEING WEAKLY FORCED AND IN THE
PRESENCE OF A MORE STABLE ENVIRONMENT. OUTSIDE OF THIS
DEVELOPMENT...EXPECT THE REMAINDER OF THE MORNING TO REMAIN DRY
WHILE LOW STRATUS FURTHER DIMINISHES THROUGH MID DAY WITH MORE
AREAS OBSERVING PARTLY CLOUDY TO PARTLY SUNNY CONDITIONS.
SHIFT FOCUS TO MAIN THUNDERSTORM THREAT FOR THIS AFTERNOON...AND
POSSIBLY INTO THE EARLY EVENING...FOR THE ENTIRE AREA OF NORTH
CENTRAL/NORTHEAST ILLINOIS AND NORTHWEST INDIANA. THE THUNDERSTORM
POTENTIAL WILL BE TIED TO APPROACHING MCV AND LINGERING FRONTAL
BOUNDARY SITUATED FROM NORTHWEST ILLINOIS BACK SOUTHEAST THROUGH
EAST CENTRAL ILLINOIS...AND INTO NORTHWEST INDIANA. AS THIS
VIGOROUS SYSTEM PUSHES EAST INTO NORTHERN ILLINOIS AND SOUTHERN
WISCONSIN BY MID DAY...IT WILL BE ENCOUNTERING AN INCREASINGLY
UNSTABLE ENVIRONMENT WHICH IS ALREADY OCCURRING OVER WESTERN
ILLINOIS WITH LATEST RAP ANALYSIS SHOWING STEADILY STEEPENING LOW
LEVEL LAPSE RATES. LIMITING FACTORS SUCH HIGH CIN IN PLACE WILL
ERODE THROUGH MID DAY WHILE CURRENT MODERATE INSTABILITY AXIS FROM
NORTHWEST ILLINOIS SOUTH TO WEST CENTRAL ILLINOIS BEGINS SPREADING
EASTWARD. SHORT TERM GUIDANCE IN FAIR AGREEMENT WITH THE TIMING OF
THIS OCCURRENCE AROUND THE 19Z TO 20Z TIME FRAME...AND WILL BE
OCCURRING AS LARGE SCALE ASCENT WITH APPROACHING SYSTEM SPREADS
EAST. MOST CURRENT GUIDANCE THIS MORNING IN AGREEMENT WITH
DEVELOPING PRECIP ACROSS THE CWA THIS AFTERNOON AND ALTHOUGH I DO
AGREE WITH THE IDEA/SOLUTION...I WONDER IF THE COVERAGE WILL BE AS
EXTENSIVE AS IS BEING ADVERTISED. THIS CONCERN IS TIED TO LOW
LEVEL CONVERGENCE POTENTIAL WITH WHICH CURRENT GUIDANCE IS
APPEARING TO BE OVERDOING AT THIS TIME. IF THIS OVERESTIMATE
CONTINUES...COVERAGE MAY NOT BE AS EXTENSIVE.
NONETHELESS...DESPITE THIS LIMITING FACTOR FEEL THAT LARGE SCALE
SUPPORT IN A MODERATELY TO STRONGLY UNSTABLE ENVIRONMENT SHOULD BE
ENOUGH TO AT LEAST DEVELOP SCATTERED DEVELOPMENT THIS AFTERNOON.
CURRENT ASSESSMENT WOULD PLACE HIGHER THREAT FOR STRONG TO SEVERE
WEATHER ACROSS THE WEST AND SOUTHWEST CWA WHERE BETTER INSTABILITY
WILL RESIDE...BUT AS THE STABLE ENVIRONMENT ACROSS NORTHEAST
ILLINOIS AND NORTHWEST INDIANA BECOMES MORE UNSTABLE LATER THIS
AFTERNOON FEEL THAT ALL AREAS COULD POTENTIALLY HAVE THE SAME
THREAT. SO DONT WANT TO REALLY POINT OUT ONE AREA OVER THE OTHER
AT THIS TIME...BUT WILL CONTINUE TO MONITOR THIS POTENTIAL WITH AN
UPDATED AFD WITH LATEST THINKING LIKELY BY MID DAY.
AREAS ALONG AND WEST OF INTERSTATE 39 COULD OBSERVE SCATTERED
STRONG TO SEVERE THUNDERSTORM DEVELOPMENT BY 19-20Z...SPREADING
EAST THROUGH REMAINING AREAS IN NORTH CENTRAL ILLINOIS AND THEN
NORTHEAST ILLINOIS IN THE 20-22Z TIME FRAME. CONFIDENCE IS LOWER
WITH REGARD TO STRONG/SEVERE THREAT IN NORTHWEST INDIANA...BUT IF
THIS WERE TO SPREAD EAST INTO THESE AREAS IT WOULD BE IN THE
22-23Z TIME WINDOW. THE MAIN SEVERE THREAT TODAY WILL BE DAMAGING
WIND GUSTS...BUT HAIL COULD POSSIBLY BECOME AN ISSUE ESPECIALLY IN
ANY OF THE MORE DEVELOPED THUNDERSTORMS.
RODRIGUEZ
&&
.DISCUSSION...
339 AM CDT
THE BASIC PATTERN THAT HAS NOW BEEN IN PLACE FOR NEARLY A WEEK WILL
CONTINUE THROUGH MONDAY...WHICH MEANS NUMEROUS FORECAST CHALLENGES
ON THIS SUMMER SOLSTICE. MORNING FOG AND STRATUS IS FIRST IN THE
TIMELINE FOLLOWED BY ITS IMPACT ON TEMPERATURES AND
DESTABILIZATION FOR THUNDERSTORM COVERAGE THIS AFTERNOON.
QUANTIFYING ANY SEVERE POTENTIAL ALSO NEEDED TO BE ASSESSED.
FINALLY...CONTINUED THUNDERSTORM CHANCES...ESPECIALLY THROUGH
MONDAY NIGHT...ROUNDED OUT THE FORECAST THIS MORNING.
FOG AND TEMPERATURES...
DENSE FOG THAT HAD EXPANDED INLAND LAST EVENING BEHIND THE
IMPRESSIVE LAKE BREEZE,,,WHICH AS OF 330 AM HAS FINALLY STALLED
NEAR INTERSTATE 74...CONTINUES OVER LAKE ADJACENT COUNTIES. WEB
CAMS AND REPORTS INDICATE THIS IS MOST DENSE NEAR THE LAKE SHORE
AND WILL CONTINUE THE DENSE FOG ADVISORY THROUGH 9 AM...WITH
POTENTIALLY SOME SHORELINE LOCALES DOWN TO A FEW HUNDRED FEET
VISIBILITY. VAD PROFILES INDICATE THE NORTHEAST FLOW IS ABOUT
2000-3000FT THICK AND AN AMDAR SOUNDING FROM LAST EVE INDICATES
SATURATION IS ONLY ABOUT HALF OF THAT. WITH THIS BEING THE LONGEST
DAYLIGHT OF THE YEAR ONE WOULD THINK WE COULD MIX THROUGH THIS
QUICKLY...ESPECIALLY WITH THE SOURCE FLOW OFF THE LAKE HAVING
CONSIDERABLY WEAKENED. THE ONE CONCERN WITH THAT IS CONVECTIVE
DEBRIS CLOUDS ARE SPREADING OVER THIS WHICH WILL FURTHER INSULATE
THIS MORNING. SO THAT WILL NEED TO BE WATCHED. HAVE ADJUSTED
FORECAST HOURLY TEMPERATURES TO SLOW THE RATE OF WARMING
CONSIDERABLY AND THAT LED TO COOLER HIGH TEMPERATURES. WHILE
TEMPERATURES WILL COULD DEPEND ON CONVECTIVE INITIATION TIME AND
COVERAGE /SEE BELOW/...FEEL THAT UNDERCUTTING GUIDANCE AND CLIMO
WAS THE WAY TO GO...OWING TO THE MUCH COOLER-THAN-NORMAL WATER
TEMPERATURES OF LAKE MICHIGAN WHICH FED THIS AREA OF FOG/STRATUS.
THUNDERSTORM POTENTIAL...
MULTIPLE LOW AMPLITUDE UPPER DISTURBANCES WILL TRANSLATE EASTWARD
TODAY ACROSS A BELT OF ZONAL FLOW EXTENDING FROM THE CENTRAL PLAINS
OVER THE FORECAST AREA. THIS IS ON THE NORTHERN END OF CONTINUED
HIGH PRECIPITABLE WATER AND UNSTABLE AIR. ONGOING CONVECTION ACROSS
WESTERN AND CENTRAL IA AS OF 330 AM HAS WEAKENED CONSIDERABLY WITH
ONLY MARGINAL MOISTURE TRANSPORT FEEDING IT. DOES LOOK LIKE THE
SHORT WAVE MAY BE CONVECTIVELY ENHANCED WITH A POSSIBLE MCV AND
TIMING THAT FEATURE SEEMS KEY FOR OUR MAIN STORM CHANCES TODAY.
THE SUITE OF GUIDANCE VARIES CONSIDERABLY AND GIVEN THAT AND
SIMPLY THE TRICKY SYNOPTIC POSITION WE ARE IN...AS WELL AS THE
MESOSCALE FACTOR OF THE CURRENT FOG/STRATUS...CONFIDENCE IS LOW
ON THUNDERSTORM COVERAGE AND TIMING TODAY.
INCREASE POPS GRADUALLY THIS MORNING WITH SOME SCATTERED ELEVATED
STORMS POSSIBLE IN NORTH CENTRAL IL...AND THEN MORE SO EARLY THIS
AFTERNOON AS MID-LEVEL FEATURE PASSES OVER THE FORECAST AREA.
CONVECTIVE TEMPERATURES LOOK TO BE AROUND 80 DEGREES AND NOT
CERTAIN IF PARTS OF NORTHEAST IL WILL REACH THAT...SO KEEP HIGHER
POPS MAINLY ALONG AND SOUTH OF THE MORE STABLE LOW-LEVEL AIR IN
PLACE /JUST SOUTH OF CHICAGO/. THIS ALSO IS WHERE LOW-LEVEL
CONVERGENCE EXISTS...ALBEIT WITH AWFULLY WEAK FLOW. SO AM NOT
ENVISIONING GREAT COVERAGE OF AFTERNOON STORMS BUT ENOUGH TO
SUPPORT 40 TO 50 PERCENT POPS AND HAVE GONE WITH SCATTERED
WORDING. CONVECTIVE CELLS POSSIBLY BECOMING MORE MULTICELL WITH
SMALL-SCALE COLD POOLS ARE THE PROBABLE EVOLUTION. MID-LEVEL LAPSE
RATES ARE POOR AND THE THERMODYNAMIC ENVIRONMENT LOOKS ALREADY
HINDERED BY THE INVERSION IN PLACE...SO NOT EXPECTING MUCH FOR
HAIL...BUT SOME OF THE MORE ORGANIZED STORMS COULD HAVE AN
ISOLATED WIND THREAT DUE TO PRECIP LOADING AND SOME HIGHER
DOWNDRAFT CAPE INDICATED BY A FEW HIGH-RES MODELS. THIS WOULD
SEEM A LITTLE MORE FAVORED SOUTH OF A ROCKFORD TO RENSSELAER LINE.
TONIGHT...
GRADUAL WARM AIR ADVECTION AND ANOTHER ONE OR TWO MINOR IMPULSES MAY
CONTINUE SEPARATE SCATTERED STORMS FROM THE EARLIER ACTIVITY AFTER
DARK...NAMELY OVER THE WESTERN AND SOUTHERN FORECAST AREA. IN
ADDITION...LIGHT WIND FLOW ELSEWHERE MAY ALLOW STRATUS AND/OR FOG TO
DEVELOP. THIS AGAIN WOULD BE ESPECIALLY FAVORED NEAR THE LAKE SHORE.
HAVE ADDED FOG MENTION ONCE AGAIN IN CHICAGO BEGINNING LATER THIS
EVE.
SUNDAY AND MONDAY...
WARM AIR ADVECTION IS FORECAST TO INCREASE ON SUNDAY WITH THE CHANCE
FOR SCATTERED STORMS. MODEL GUIDANCE IS IN GOOD AGREEMENT WITH
NOTHING OVERLY ORGANIZED...SO HAVE KEPT POPS NEAR WHERE THEY
WERE. TEMPERATURES AGAIN WILL BE TRICKY...REMAINING MUCH COOLER
NEAR THE LAKE AND POTENTIALLY HAVING TO FIGHT THROUGH MORNING
STRATUS. HEIGHT FALLS ARE EXPECTED TO SPREAD INTO THE FORECAST
AREA ON MONDAY AND THAT LOOKS TO PRESENT THE BEST CHANCE FOR
STORMS INCLUDING INTO MONDAY NIGHT AS THE FRONT APPROACHES AND
MOVES THROUGH. PRECIPITABLE WATER IS ANTICIPATED TO CLIMB BACK
TO NEAR 1.75 INCHES WITH STRONG DEEP LAYER MOISTURE CONVERGENCE.
WHILE THE DEEP LAYER SHEAR IS NOT PARTICULARLY STRONG OWING TO THE
MARGINAL MID-LEVEL FLOW...ENOUGH INSTABILITY AND FOCUS IS PRESENT
WITH THE SYNOPTIC PATTERN TO WARRANT A HIGHER LIKELIHOOD FOR RAIN.
THE MORE SUN AND GREATER INSTABILITY ON MONDAY THEN THE LIKELY
BETTER CHANCES FOR SOME SEVERE POSSIBILITY.
TUESDAY AND BEYOND...
LONG RANGE GUIDANCE IS IN DECENT AGREEMENT WITH RAIN CHANCES
DIMINISHING THROUGH TUESDAY WITH THE AIR MASS BEING SOMEWHAT
SCOURED OUT SEEING DEW POINTS FORECAST DOWN INTO THE LOWER 60S. THE
UPPER AND MID-LEVEL PATTERN WILL KEEP US SOMEWHAT
UNSETTLED...THOUGH DEEP MOISTURE AND INSTABILITY WILL BE LESS.
HAVE A LOT OF SMALL POPS BUT THE OVERALL PATTERN TUE-THU DOES NOT
LOOK CONDUCIVE FOR HIGH IMPACT WEATHER. ONSHORE FLOW ON A FEW
MIDWEEK DAYS LOOKS TO KEEP TEMPERATURES ONCE AGAIN QUITE A BIT
COOLER NEAR THE LAKE.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* TIMING OF RECOVERY FROM LIFR TO VFR AROUND 15Z.
* TIMING AND DURATION OF TSRA THIS AFTERNOON.
* TIMING OF CIGS/VIS DROPPING TO IFR/LIFR OVERNIGHT TONIGHT.
KREIN/BEACH
//DISCUSSION...UPDATED 12Z...
MAIN CONCERNS REMAIN THE TIMING OF THE IMPROVEMENT OF CONDITIONS
FROM LIFR TO VFR LATER THIS MORNING AND THEN THE TIMING OF TSRA TO
IMPACT THE TERMINALS THIS AFTERNOON. FOR THE CIGS/VIS...EXPECT A
GRADUAL IMPROVEMENT THIS MORNING. HAD INITIALLY HAD A FASTER
IMPROVEMENT WITH THE GREATER SUN ANGLE FOR THE FIRST DAY OF
SUMMER...BUT CIRRUS BLOWOFF FROM UPSTREAM CONVECTIVE ACTIVITY WILL
SLOW THE SFC WARMING AND MIXING...SO WILL START OUT THE 12Z TAFS
AT LIFR LEVELS. HAVE NOTED TOWER VISIBILITY OF 1/8SM IN THE 11Z ORD
METAR...BUT ANTICIPATE GRADUAL IMPROVEMENT TO VFR BY ARND 14Z.
THE OTHER CONCERN IS TIMING OF TSRA INCREASING IN COVERAGE AND HOW
THE TERMINALS MAY BE IMPACTED. AT 11Z...RADAR TRENDS INDICATE
DIMINISHING COVERAGE OVER IOWA...WITH A SHORT LINE OF STORMS
MOVING INTO SWRN WI LIKELY ASSOCIATED WITH AN OUTFLOW BOUNDARY
FROM THE EARLIER STORMS. DO NOT ANTICIPATE THAT THIS LINE WILL
IMPACT RFD...BUT HAVE MOVED UP THE TIMING OF TS AT THE TERMINALS
AS THE LATEST HIGH RES MODEL GUIDANCE AS WELL AS LATEST RADAR
TRENDS ALL POINT TO FASTER PROGRESSION OF THE PARENT SHORTWAVE.
THERE STILL REMAINS SOME QUESTION AS TO THE TIMING OF THE
DEVELOPMENT...WITH THE RFD AREA POSSIBLY SEEING MORE SCT TSRA WITH
COVERAGE INCREASING AS THE SYSTEM MOVES THROUGH NRN IL INTO NRN
IN. THE SYSTEM SHOULD BE RATHER FAST MOVING AND DURATION OF IMPACT
SHOULD BE FAIRLY SHORT...SO HAVE GONE WITH A 2 HR TEMPO GROUP.
FOLLOWING THE PASSAGE OF THIS SYSTEM...CLOUD COVER SHOULD CLEAR
OUT OVERNIGHT...AND WITH DECREASING WINDS AND AMPLE MOISTURE IN
PLACE...THERE SHOULD BE A RETURN OF FOG AND STRATUS OVERNIGHT.
HAVE CONSERVATIVELY INTRODUCED IFR/LIFR CONDITIONS AT THE END OF
THE PERIOD...BUT THERE IS THE POSSIBILITY CONDITIONS...ESPECIALLY
VISIBILITY COULD DROP LOWER.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* LOW TO MEDIUM CONFIDENCE IN TIMING OF CONDITIONS IMPROVING TO VFR.
* MEDIUM CONFIDENCE IN TIMING OF TSRA IMPACING THE TERMINALS.
* MEDIUM CONFIDENCE IN WIND TRENDS.
* MEDIUM CONFIDENCE IN CONDTIONS DROPPING TO IFR/LIFR AGAIN
TONIGHT...BUT LOWER CONFIDENCE IN TIMING.
KREIN/BEACH
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...CHANCE TSRA.
MONDAY...TSRA LIKELY.
TUESDAY THROUGH THURSDAY...PERIOD CHANCES FOR TSRA/SHRA.
THURSDAY NIGHT AND FRIDAY...VFR. WX NIL.
KREIN
&&
.MARINE...
245 AM CDT
HIGH PRESSURE CENTERED WILL SIT OVER JAMES BAY THROUGH SATURDAY
NIGHT WITH WEAK RIDGING EXTENDING SOUTH ACROSS LAKE MICHIGAN TO
THE LOWER MISSISSIPPI VALLEY. A WEAK STATIONARY FRONT IS DRAPED
FROM NORTHERN MINNESOTA...JUST SOUTH OF THE LAKE TO THE OHIO
VALLEY. WITH WARM...MOIST AIR SPREADING OVER THE COLD LAKE WATER
AND SHIP OBS AND COASTAL SITES AND WEB CAMS INDICATING DENSE
FOG...A DENSE FOG ADVISORY HAS BEEN ISSUED FOR ALL OF THE OPEN
WATERS AND THE ILLINOIS AND INDIANA NEARSHORE WATERS. HAVE
EXTENDED THE DENSE FOG ADVISORY THROUGH SUNDAY MORNING AS THERE
WILL BE LITTLE CHANGE TO THE AIRMASS OVER THE LAKE. THE EXCEPTION
MAY BE THE FAR NORTHERN PORTION OF THE LAKE...WHERE WINDS SHOULD
TREND A LITTLE MORE EASTERLY THAN SOUTHERLY AND ADVECT SOME DRIER
AIR OVER THE LAKE...LIMITING THE DENSE FOG POTENTIAL. A COMPLEX
AREA OF LOW PRESSURE OVER THE CENTRAL PLAINS WITH MULTIPLE LOW
PRESSURE CENTERS...WILL GRADUALLY MOVE EAST ACROSS THE PLAINS AND
TO THE WESTERN GREAT LAKES REGION BY EARLY MONDAY. A WEAK COLD
FRONT SHOULD PUSH ACROSS THE LAKE MONDAY OR MONDAY NIGHT...TURNING
WINDS FROM GENERALLY SOUTHERLY TO MORE NORTHERLY. AS A LARGE AREA
OF HIGH PRESSURE BUILDS OUT OF CANADA TO THE UPPER GREAT LAKES
TUESDAY NIGHT AND WEDNESDAY...COOLER...DRIER AIR WILL OVERSPREAD
THE LAKE. THE COMBINATION OF THE FRONTAL PASSAGE AND THE BUILDING
HIGH PRESSURE SHOULD BRING AN END TO THE FOG POTENTIAL.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...DENSE FOG ADVISORY...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-
LMZ565-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-
LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-LMZ870-
LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 10 AM SUNDAY.
&&
$$
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 CHICAGO/ROMEOVILLE IL
908 AM CDT SAT JUN 21 2014
.DISCUSSION...
339 AM CDT
THE BASIC PATTERN THAT HAS NOW BEEN IN PLACE FOR NEARLY A WEEK WILL
CONTINUE THROUGH MONDAY...WHICH MEANS NUMEROUS FORECAST CHALLENGES
ON THIS SUMMER SOLSTICE. MORNING FOG AND STRATUS IS FIRST IN THE
TIMELINE FOLLOWED BY ITS IMPACT ON TEMPERATURES AND
DESTABILIZATION FOR THUNDERSTORM COVERAGE THIS AFTERNOON.
QUANTIFYING ANY SEVERE POTENTIAL ALSO NEEDED TO BE ASSESSED.
FINALLY...CONTINUED THUNDERSTORM CHANCES...ESPECIALLY THROUGH
MONDAY NIGHT...ROUNDED OUT THE FORECAST THIS MORNING.
FOG AND TEMPERATURES...
DENSE FOG THAT HAD EXPANDED INLAND LAST EVENING BEHIND THE
IMPRESSIVE LAKE BREEZE,,,WHICH AS OF 330 AM HAS FINALLY STALLED
NEAR INTERSTATE 74...CONTINUES OVER LAKE ADJACENT COUNTIES. WEB
CAMS AND REPORTS INDICATE THIS IS MOST DENSE NEAR THE LAKE SHORE
AND WILL CONTINUE THE DENSE FOG ADVISORY THROUGH 9 AM...WITH
POTENTIALLY SOME SHORELINE LOCALES DOWN TO A FEW HUNDRED FEET
VISIBILITY. VAD PROFILES INDICATE THE NORTHEAST FLOW IS ABOUT
2000-3000FT THICK AND AN AMDAR SOUNDING FROM LAST EVE INDICATES
SATURATION IS ONLY ABOUT HALF OF THAT. WITH THIS BEING THE LONGEST
DAYLIGHT OF THE YEAR ONE WOULD THINK WE COULD MIX THROUGH THIS
QUICKLY...ESPECIALLY WITH THE SOURCE FLOW OFF THE LAKE HAVING
CONSIDERABLY WEAKENED. THE ONE CONCERN WITH THAT IS CONVECTIVE
DEBRIS CLOUDS ARE SPREADING OVER THIS WHICH WILL FURTHER INSULATE
THIS MORNING. SO THAT WILL NEED TO BE WATCHED. HAVE ADJUSTED
FORECAST HOURLY TEMPERATURES TO SLOW THE RATE OF WARMING
CONSIDERABLY AND THAT LED TO COOLER HIGH TEMPERATURES. WHILE
TEMPERATURES WILL COULD DEPEND ON CONVECTIVE INITIATION TIME AND
COVERAGE /SEE BELOW/...FEEL THAT UNDERCUTTING GUIDANCE AND CLIMO
WAS THE WAY TO GO...OWING TO THE MUCH COOLER-THAN-NORMAL WATER
TEMPERATURES OF LAKE MICHIGAN WHICH FED THIS AREA OF FOG/STRATUS.
THUNDERSTORM POTENTIAL...
MULTIPLE LOW AMPLITUDE UPPER DISTURBANCES WILL TRANSLATE EASTWARD
TODAY ACROSS A BELT OF ZONAL FLOW EXTENDING FROM THE CENTRAL PLAINS
OVER THE FORECAST AREA. THIS IS ON THE NORTHERN END OF CONTINUED
HIGH PRECIPITABLE WATER AND UNSTABLE AIR. ONGOING CONVECTION ACROSS
WESTERN AND CENTRAL IA AS OF 330 AM HAS WEAKENED CONSIDERABLY WITH
ONLY MARGINAL MOISTURE TRANSPORT FEEDING IT. DOES LOOK LIKE THE
SHORT WAVE MAY BE CONVECTIVELY ENHANCED WITH A POSSIBLE MCV AND
TIMING THAT FEATURE SEEMS KEY FOR OUR MAIN STORM CHANCES TODAY.
THE SUITE OF GUIDANCE VARIES CONSIDERABLY AND GIVEN THAT AND
SIMPLY THE TRICKY SYNOPTIC POSITION WE ARE IN...AS WELL AS THE
MESOSCALE FACTOR OF THE CURRENT FOG/STRATUS...CONFIDENCE IS LOW
ON THUNDERSTORM COVERAGE AND TIMING TODAY.
INCREASE POPS GRADUALLY THIS MORNING WITH SOME SCATTERED ELEVATED
STORMS POSSIBLE IN NORTH CENTRAL IL...AND THEN MORE SO EARLY THIS
AFTERNOON AS MID-LEVEL FEATURE PASSES OVER THE FORECAST AREA.
CONVECTIVE TEMPERATURES LOOK TO BE AROUND 80 DEGREES AND NOT
CERTAIN IF PARTS OF NORTHEAST IL WILL REACH THAT...SO KEEP HIGHER
POPS MAINLY ALONG AND SOUTH OF THE MORE STABLE LOW-LEVEL AIR IN
PLACE /JUST SOUTH OF CHICAGO/. THIS ALSO IS WHERE LOW-LEVEL
CONVERGENCE EXISTS...ALBEIT WITH AWFULLY WEAK FLOW. SO AM NOT
ENVISIONING GREAT COVERAGE OF AFTERNOON STORMS BUT ENOUGH TO
SUPPORT 40 TO 50 PERCENT POPS AND HAVE GONE WITH SCATTERED
WORDING. CONVECTIVE CELLS POSSIBLY BECOMING MORE MULTICELL WITH
SMALL-SCALE COLD POOLS ARE THE PROBABLE EVOLUTION. MID-LEVEL LAPSE
RATES ARE POOR AND THE THERMODYNAMIC ENVIRONMENT LOOKS ALREADY
HINDERED BY THE INVERSION IN PLACE...SO NOT EXPECTING MUCH FOR
HAIL...BUT SOME OF THE MORE ORGANIZED STORMS COULD HAVE AN
ISOLATED WIND THREAT DUE TO PRECIP LOADING AND SOME HIGHER
DOWNDRAFT CAPE INDICATED BY A FEW HIGH-RES MODELS. THIS WOULD
SEEM A LITTLE MORE FAVORED SOUTH OF A ROCKFORD TO RENSSELAER LINE.
TONIGHT...
GRADUAL WARM AIR ADVECTION AND ANOTHER ONE OR TWO MINOR IMPULSES MAY
CONTINUE SEPARATE SCATTERED STORMS FROM THE EARLIER ACTIVITY AFTER
DARK...NAMELY OVER THE WESTERN AND SOUTHERN FORECAST AREA. IN
ADDITION...LIGHT WIND FLOW ELSEWHERE MAY ALLOW STRATUS AND/OR FOG TO
DEVELOP. THIS AGAIN WOULD BE ESPECIALLY FAVORED NEAR THE LAKE SHORE.
HAVE ADDED FOG MENTION ONCE AGAIN IN CHICAGO BEGINNING LATER THIS
EVE.
SUNDAY AND MONDAY...
WARM AIR ADVECTION IS FORECAST TO INCREASE ON SUNDAY WITH THE CHANCE
FOR SCATTERED STORMS. MODEL GUIDANCE IS IN GOOD AGREEMENT WITH
NOTHING OVERLY ORGANIZED...SO HAVE KEPT POPS NEAR WHERE THEY
WERE. TEMPERATURES AGAIN WILL BE TRICKY...REMAINING MUCH COOLER
NEAR THE LAKE AND POTENTIALLY HAVING TO FIGHT THROUGH MORNING
STRATUS. HEIGHT FALLS ARE EXPECTED TO SPREAD INTO THE FORECAST
AREA ON MONDAY AND THAT LOOKS TO PRESENT THE BEST CHANCE FOR
STORMS INCLUDING INTO MONDAY NIGHT AS THE FRONT APPROACHES AND
MOVES THROUGH. PRECIPITABLE WATER IS ANTICIPATED TO CLIMB BACK
TO NEAR 1.75 INCHES WITH STRONG DEEP LAYER MOISTURE CONVERGENCE.
WHILE THE DEEP LAYER SHEAR IS NOT PARTICULARLY STRONG OWING TO THE
MARGINAL MID-LEVEL FLOW...ENOUGH INSTABILITY AND FOCUS IS PRESENT
WITH THE SYNOPTIC PATTERN TO WARRANT A HIGHER LIKELIHOOD FOR RAIN.
THE MORE SUN AND GREATER INSTABILITY ON MONDAY THEN THE LIKELY
BETTER CHANCES FOR SOME SEVERE POSSIBILITY.
TUESDAY AND BEYOND...
LONG RANGE GUIDANCE IS IN DECENT AGREEMENT WITH RAIN CHANCES
DIMINISHING THROUGH TUESDAY WITH THE AIR MASS BEING SOMEWHAT
SCOURED OUT SEEING DEW POINTS FORECAST DOWN INTO THE LOWER 60S. THE
UPPER AND MID-LEVEL PATTERN WILL KEEP US SOMEWHAT
UNSETTLED...THOUGH DEEP MOISTURE AND INSTABILITY WILL BE LESS.
HAVE A LOT OF SMALL POPS BUT THE OVERALL PATTERN TUE-THU DOES NOT
LOOK CONDUCIVE FOR HIGH IMPACT WEATHER. ONSHORE FLOW ON A FEW
MIDWEEK DAYS LOOKS TO KEEP TEMPERATURES ONCE AGAIN QUITE A BIT
COOLER NEAR THE LAKE.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* TIMING OF RECOVERY FROM LIFR TO VFR AROUND 15Z.
* TIMING AND DURATION OF TSRA THIS AFTERNOON.
* TIMING OF CIGS/VIS DROPPING TO IFR/LIFR OVERNIGHT TONIGHT.
KREIN/BEACH
//DISCUSSION...UPDATED 12Z...
MAIN CONCERNS REMAIN THE TIMING OF THE IMPROVEMENT OF CONDITIONS
FROM LIFR TO VFR LATER THIS MORNING AND THEN THE TIMING OF TSRA TO
IMPACT THE TERMINALS THIS AFTERNOON. FOR THE CIGS/VIS...EXPECT A
GRADUAL IMPROVEMENT THIS MORNING. HAD INITIALLY HAD A FASTER
IMPROVEMENT WITH THE GREATER SUN ANGLE FOR THE FIRST DAY OF
SUMMER...BUT CIRRUS BLOWOFF FROM UPSTREAM CONVECTIVE ACTIVITY WILL
SLOW THE SFC WARMING AND MIXING...SO WILL START OUT THE 12Z TAFS
AT LIFR LEVELS. HAVE NOTED TOWER VISIBILITY OF 1/8SM IN THE 11Z ORD
METAR...BUT ANTICIPATE GRADUAL IMPROVEMENT TO VFR BY ARND 14Z.
THE OTHER CONCERN IS TIMING OF TSRA INCREASING IN COVERAGE AND HOW
THE TERMINALS MAY BE IMPACTED. AT 11Z...RADAR TRENDS INDICATE
DIMINISHING COVERAGE OVER IOWA...WITH A SHORT LINE OF STORMS
MOVING INTO SWRN WI LIKELY ASSOCIATED WITH AN OUTFLOW BOUNDARY
FROM THE EARLIER STORMS. DO NOT ANTICIPATE THAT THIS LINE WILL
IMPACT RFD...BUT HAVE MOVED UP THE TIMING OF TS AT THE TERMINALS
AS THE LATEST HIGH RES MODEL GUIDANCE AS WELL AS LATEST RADAR
TRENDS ALL POINT TO FASTER PROGRESSION OF THE PARENT SHORTWAVE.
THERE STILL REMAINS SOME QUESTION AS TO THE TIMING OF THE
DEVELOPMENT...WITH THE RFD AREA POSSIBLY SEEING MORE SCT TSRA WITH
COVERAGE INCREASING AS THE SYSTEM MOVES THROUGH NRN IL INTO NRN
IN. THE SYSTEM SHOULD BE RATHER FAST MOVING AND DURATION OF IMPACT
SHOULD BE FAIRLY SHORT...SO HAVE GONE WITH A 2 HR TEMPO GROUP.
FOLLOWING THE PASSAGE OF THIS SYSTEM...CLOUD COVER SHOULD CLEAR
OUT OVERNIGHT...AND WITH DECREASING WINDS AND AMPLE MOISTURE IN
PLACE...THERE SHOULD BE A RETURN OF FOG AND STRATUS OVERNIGHT.
HAVE CONSERVATIVELY INTRODUCED IFR/LIFR CONDITIONS AT THE END OF
THE PERIOD...BUT THERE IS THE POSSIBILITY CONDITIONS...ESPECIALLY
VISIBILITY COULD DROP LOWER.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* LOW TO MEDIUM CONFIDENCE IN TIMING OF CONDITIONS IMPROVING TO VFR.
* MEDIUM CONFIDENCE IN TIMING OF TSRA IMPACING THE TERMINALS.
* MEDIUM CONFIDENCE IN WIND TRENDS.
* MEDIUM CONFIDENCE IN CONDTIONS DROPPING TO IFR/LIFR AGAIN
TONIGHT...BUT LOWER CONFIDENCE IN TIMING.
KREIN/BEACH
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...CHANCE TSRA.
MONDAY...TSRA LIKELY.
TUESDAY THROUGH THURSDAY...PERIOD CHANCES FOR TSRA/SHRA.
THURSDAY NIGHT AND FRIDAY...VFR. WX NIL.
KREIN
&&
.MARINE...
245 AM CDT
HIGH PRESSURE CENTERED WILL SIT OVER JAMES BAY THROUGH SATURDAY
NIGHT WITH WEAK RIDGING EXTENDING SOUTH ACROSS LAKE MICHIGAN TO
THE LOWER MISSISSIPPI VALLEY. A WEAK STATIONARY FRONT IS DRAPED
FROM NORTHERN MINNESOTA...JUST SOUTH OF THE LAKE TO THE OHIO
VALLEY. WITH WARM...MOIST AIR SPREADING OVER THE COLD LAKE WATER
AND SHIP OBS AND COASTAL SITES AND WEB CAMS INDICATING DENSE
FOG...A DENSE FOG ADVISORY HAS BEEN ISSUED FOR ALL OF THE OPEN
WATERS AND THE ILLINOIS AND INDIANA NEARSHORE WATERS. HAVE
EXTENDED THE DENSE FOG ADVISORY THROUGH SUNDAY MORNING AS THERE
WILL BE LITTLE CHANGE TO THE AIRMASS OVER THE LAKE. THE EXCEPTION
MAY BE THE FAR NORTHERN PORTION OF THE LAKE...WHERE WINDS SHOULD
TREND A LITTLE MORE EASTERLY THAN SOUTHERLY AND ADVECT SOME DRIER
AIR OVER THE LAKE...LIMITING THE DENSE FOG POTENTIAL. A COMPLEX
AREA OF LOW PRESSURE OVER THE CENTRAL PLAINS WITH MULTIPLE LOW
PRESSURE CENTERS...WILL GRADUALLY MOVE EAST ACROSS THE PLAINS AND
TO THE WESTERN GREAT LAKES REGION BY EARLY MONDAY. A WEAK COLD
FRONT SHOULD PUSH ACROSS THE LAKE MONDAY OR MONDAY NIGHT...TURNING
WINDS FROM GENERALLY SOUTHERLY TO MORE NORTHERLY. AS A LARGE AREA
OF HIGH PRESSURE BUILDS OUT OF CANADA TO THE UPPER GREAT LAKES
TUESDAY NIGHT AND WEDNESDAY...COOLER...DRIER AIR WILL OVERSPREAD
THE LAKE. THE COMBINATION OF THE FRONTAL PASSAGE AND THE BUILDING
HIGH PRESSURE SHOULD BRING AN END TO THE FOG POTENTIAL.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...DENSE FOG ADVISORY...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-
LMZ565-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-
LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-LMZ870-
LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 10 AM SUNDAY.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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Area Forecast Discussion
National Weather Service Lincoln IL
653 AM CDT Sat Jun 21 2014
.DISCUSSION...
ISSUED 248 AM CDT Sat Jun 21 2014
Surface ridging keeping control on a relatively stagnant airmass
over the region. Showers, thunderstorms, and mesoscale boundaries
controlling much of the dynamics for the last few days...and the
trend will continue for the next few. Significant wave over NE/IA
this morning progged to make its way over the Mississippi River
Valley later this afternoon/evening and bring the next best
chances of rain. However, some of the models weaken the impulse
considerably, keeping the main wave further to the west for Sun
night through Mon night. To say that the models, both high res and
longer range, have been having a hard time resolving the
convective elements in this hot and humid airmass is a drastic
understatement. Forecast is full of pops and it is almost
impossible to carve them down with much accuracy simply because it
is a hot, humid, and unstable summer airmass. Scattered
thunderstorms is more the rule than the exception, particularly in
the afternoon (diurnal influence) and evening (evolution of
convective masses that form elsewhere and propagate through.)
SHORT TERM...Today and tomorrow...
Hot and humid again today with weak sfc winds and heat indices
into the 90s by late afternoon. GFS and NAM both relentless with
the progression of the convection over NE/IA this morning, pushing
into ILX this afternoon. HRRR and 4km wrf a little more familiar
to recent trends and dissipates the storms as they approach the
Miss River Valley and the influence of the ridge, but re-fire the
outflow later in the afternoon. More recent HRRR delaying the
re-fire until closer to 20z over Mid Miss River...whereas the 4km
wrf igniting on several different boundaries through the
afternoon. Considering the lack of consensus...will go with a
combination of models, and continuity. Chances through the day,
increasing this afternoon and into the evening hours. Tomorrow
even less clear--scattered potential, and details potentially more
accessible after the prev activity from tonight sets up any
outflow boundaries. Both days in the warm and humid airmass and
heat indices into the 90s.
LONG TERM...Monday through Friday...
Upper trof/wave pushing through the region on Monday night into
Tuesday bringing signif chance, increasing from Sun night into
Monday night...and a slightly cooler Tuesday through the end of
the week. Still warm, but potentially less humidity as winds
become more westerly on Tuesday, picking up a northerly component
by Wednesday. Forecast trending drier from Tuesday through
Wednesday. Another wave Thursday brings back some pops ahead of
the next big storm system developing over the SW for late next
weekend.
HJS
&&
.AVIATION...
ISSUED 653 AM CDT Sat Jun 21 2014
Weak high pressure extending from Michigan to the SW across IL
will gradually give way to a storm complex this afternoon. Strong
to severe storms will be possible as instability maximizes this
afternoon. Wind shear will be weak, so pulse-type storms are
expected, with downburst winds the primary hazard, and hail a
secondary threat. Timing and location of the storm initiation are
still a bit uncertain, so VCTS was still the only inclusion in all
the TAFs for the 12z issuance. PIA could see storms as early as
18z, with storms progressing east toward CMI and DEC by 20-21z.
Storm chances will be primarily during a 3-4 hour window, then
diminish as the complex progresses east-southeast. Diurnal
stabilization should help reduce storm coverage as the evening
progresses.
Winds will start out light under the surface ridge axis, then
increase from the south-southwest as a surface trough approaches.
Wind speeds should generally remain below 10kt today, then become
light and variable again this evening.
Shimon
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1043 AM EDT SAT JUN 21 2014
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 322 AM EDT SAT JUN 21 2014
SLIGHTLY DRIER AIR WILL BE IN PLACE FOR THE BEGINNING OF TODAY.
HOWEVER...WESTERN PORTIONS OF CENTRAL INDIANA COULD SEE SOME
SCATTERED SHOWERS AND THUNDERSTORMS THIS EVENING AND TONIGHT FROM
ONGOING ACTIVITY OVER NEBRASKA AND IOWA. FURTHER OUT...A FRONTAL
BOUNDARY WILL BRING DAILY CHANCES FOR SHOWERS AND THUNDERSTORMS
THROUGH MOST OF THE EXTENDED PERIOD.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 1043 AM EDT SAT JUN 21 2014
LOW STRATUS DECK CONTINUES TO ADVANCE SOUTH TO THE NORTHEAST OF
THE INDY METRO WITHIN WEAK AREA OF COLD ADVECTION. UNDER THE CLOUD
DECK...TEMP RISES HAD BEEN STUNTED SO FAR WITH 14Z TEMPS IN THE
UPPER 60S/LOWER 70S. FURTHER SOUTH/WEST...TEMPS HAD WARMED INTO
THE MID/UPPER 70S.
WHILE SOME MVFR VISIBILITIES ARE PRESENT UNDER THE STRATUS...FOG
HAS GENERALLY DISPERSED AND HAVE REMOVED FROM THE FORECAST. WHILE
STRATUS CONTINUES TO ADVANCE SOUTH...RECENT SATELLITE TRENDS
INDICATE FRONT EDGE OF THE CLOUD DECK IS BEGINNING TO MIX OUT.
THIS TREND SHOULD CONTINUE THROUGH 18Z WITH SKIES BECOMING PARTLY
CLOUDY WITH VFR CU. THE CLOUDS THIS MORNING THOUGH ARE LIKELY TO
IMPACT OVERALL HIGHS IN THE NORTHEAST THIS AFTERNOON AND HAVE
DROPPED TEMPS A FEW DEGREES.
FOCUS THEN SHIFTS TO CONVECTIVE POTENTIAL BEGINNING LATE AFTERNOON
INTO THE EVENING HOURS. WELL DEFINED MCV LOCATED OVER EASTERN IOWA
FROM THE REMNANTS OF THE OVERNIGHT CONVECTION ACROSS NEBRASKA/
IOWA. THIS FEATURE PROGGED TO TRACK EAST INTO NORTHERN ILLINOIS
THROUGH THE AFTERNOON SPARKING NEW CONVECTIVE DEVELOPMENT.
MAJORITY OF THE MOST CURRENT MODEL DATA BRINGING CONVECTION INTO
THE NORTHERN WABASH VALLEY BY EARLY EVENING WITH STORMS CONTINUING
INTO THE OVERNIGHT. STILL A LOT OF UNCERTAINTY WITH RESPECT TO HOW
FAR SOUTH AND EAST THE CONVECTION CAN SPREAD ACROSS THE FORECAST
AREA BEFORE DYING OUT AS AIRMASS WILL REMAIN MORE STABLE THE
FURTHER EAST ONE GOES. SHORT RANGE MODEL GUIDANCE FOCUSES BETTER
INSTABILITY AND DEEPER MOISTURE IN THE VICINITY OF THE RETURNING
FRONTAL BOUNDARY ACROSS ILLINOIS THROUGH THIS EVENING...POSSIBLY
WORKING INTO THE WESTERN PART OF THE STATE AS WELL. RAP INDICATING
A SUBTLE INCREASE IN LOW LEVEL FLOW THIS EVENING WHICH WOULD
SUPPORT MAINTENANCE OF SCATTERED CONVECTION INTO THE OVERNIGHT.
DESPITE SPC BACKING OFF ON THE DAY 1 SLIGHT RISK TO JUST WEST OF
THE AREA...HAVE MAINTAINED AN ISOLATED SEVERE MENTION IN THE HWO
WITH THE BEST POTENTIAL OVER THE NORTHWEST FORECAST AREA. LOW
CONFIDENCE IN AVAILABLE FORCING AND INSTABILITY ARE MITIGATING
FACTORS IN SEVERE POTENTIAL FURTHER EAST ACROSS CENTRAL INDIANA.
ZONE AND GRID UPDATES OUT.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
ISSUED AT 322 AM EDT SAT JUN 21 2014
THE MAIN FOCUS OF THE SHORT TERM WILL BE SHOWER/THUNDERSTORM
POTENTIAL OVER WESTERN PORTIONS OF FORECAST AREA THIS EVENING
AND TONIGHT. AGAIN...DETAILS ARE UNCLEAR AT THIS TIME AS TO HOW
WAVES FROM CURRENT CONVECTIVE ACTIVITY OVER THE MID MISSOURI
VALLEY ARE GOING TO PLAY OUT AND WILL HAVE TO BE MONITORED
THROUGHOUT THE DAY.
CONFIDENCE BECOMES A BIT HIGHER LATER IN THE SHORT TERM PERIOD
THOUGH AS SURFACE FRONTAL BOUNDARY SHIFTS BACK TO THE NORTH ON
SUNDAY AND MONDAY IN THE FORM OF A WARM FRONT. THIS WILL PROVIDE
A MOIST WARM UNSTABLE ENVIRONMENT AGAIN AND FORCING FOR ADDITIONAL
SHOWER/THUNDERSTORM DEVELOPMENT.
TEMPS...HIGHS IN THE MID TO UPPER 80S AND LOWS IN THE 70S WILL
PREVAIL FOR DURATION OF SHORT TERM PERIOD...STUCK CLOSE TO A MODEL
BLEND.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 234 AM EDT SAT JUN 21 2014
THE DETERMINISTIC EXTENDED MODELS ARE CONTINUING TO HAVE TIMING AND
RUN TO RUN DIFFERENCES OVER THE EVOLUTION OF GREAT LAKES TROUGHING
NEXT WEEK. SO...WILL ACCEPT THE REGIONAL ALLBLEND WHICH HAS CHANCE
POPS EACH PERIOD THROUGH FRIDAY ASSOCIATED WITH WAVES AROUND THE
BASE OF THE AFOREMENTIONED TROUGH COUPLED WITH A WARM...MOIST AND
UNSTABLE ENVIRONMENT.
ALLBLEND CONTINUES TO ADVERTISE THE HIGHEST POPS ON TUESDAY AS A
WEAK COLD FRONT DROPS SOUTHEAST OVER THE AREA BEFORE STALLING. A LOT
WILL DEPEND ON WHERE THIS FRONT ENDS UP LAYING OUT WHICH IS NEVER AN
EASY CALL THIS TIME OF YEAR.
SEASONABLE ALLBLEND HIGHS IN THE 80S LOOK OK FOR TEMPERATURES...AND
WITH MODEL ISSUES...DO NOT WANT TO MESS MUCH WITH THEM.
&&
.AVIATION /DISCUSSION FOR THE 211500Z TAF ISSUANCE/...
ISSUED AT 1020 AM EDT SAT JUN 21 2014
SATELLITE LOOP SHOWS A STRATUS DECK OVER NORTHERN INDIANA MAKING
IT/S WAY TO THE SOUTH AND HAS REACHED KLAF. THINK IT COULD CONTINUE
THERE FOR THE NEXT 2 HOURS BEFORE MIXING UP SO ADDED A TEMPO IFR
GROUP FOR THIS. AT KIND ADDED A FEW015 GROUP STARTING AT 16Z SINCE
THE DECK IS MOVING TOWARD THERE BUT ALSO LOOKS LIKE IT/S BREAKING UP
AND PROBABLY WILL NOT IMPACT THE CEILING AND CATEGORY. PREVIOUS
DISCUSSION FOLLOWS...
FRONTAL BOUNDARY SHOULD BE NEAR THE TERMINALS TODAY...BUT WITH
MOISTURE MARGINAL IN THE LOWER LEVELS...DIURNAL CU PROGS SUGGEST
ONLY SCATTERED DIURNAL CU DESPITE CONVECTIVE TEMPERATURES WELL
WITHIN REACH BY LATE MORNING. SO...CONFIDENCE IS NOT HIGH ENOUGH TO
MENTION THUNDERSTORMS AT THIS TIME. HOWEVER...LAF WOULD SEEM TO HAVE
THE HIGHEST CHANCE AND AFTER 00Z TONIGHT.
WITH WEAK SURFACE PRESSURE GRADIENT...WINDS WILL BE LIGHT AND
VARIABLE OR CALM THROUGH TONIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...TDUD
NEAR TERM...RYAN
SHORT TERM...TDUD
LONG TERM...MK
AVIATION...MK/CP
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AREA FORECAST DISCUSSION
NWS GOODLAND KS
900 AM MDT SAT JUN 21 2014
.UPDATE...
ISSUED AT 900 AM MDT SAT JUN 21 2014
UPDATE REQUIRED FOR THE REST OF THE DAY TO BETTER REPRESENT
CURRENT RADAR TRENDS AND THE NEXT 8-9 HOURS OF TEMPS/DP/WINDS/POP
AND WX.
SHOWERS AND THUNDERSTORMS THAT HAVE BEEN LOCATED ALONG THE KS/NE
BORDER THIS MORNING SLOWLY STARTING TO LOSE INTENSITY AND AREAL
COVERAGE AND THIS TREND SHOULD CONTINUE THE REST OF THE MORNING.
DURING THE AFTERNOON CURRENTLY EXPECTING A SFC TROUGH TO SET UP
NEAR/JUST EAST OF THE CO/KS BORDER. MAY HAVE A FEW STORMS DEVELOP
ALONG THIS BY MID/LATE AFTERNOON WITH A SLOW EASTWARD PUSH TO THE
EAST AS A STRONG WEATHER DISTURBANCE AND BETTER UPPER JET
DIVERGENCE MOVES IN TO EASTERN COLORADO. THIS SHOULD BE ENOUGH TO
CREATE SOME STRONG/SEVERE STORMS IN EASTERN COLORADO AND ALONG THE
SFC TROUGH IN WESTERN KANSAS/SOUTHWEST NEBRASKA. LARGE HAIL AND
DAMAGING WINDS WILL BE THE PRIMARY THREATS.
HIGH TEMPERATURES GENERALLY IN THE UPPER 80S TO LOW 90S IN EASTERN
COLORADO WITH LOW TO MID 90S EAST OF THE BORDER. MAY SEE SOME
UPPER 90S...ESPECIALLY ACROSS THE EAST THROUGH SOUTH WHERE IMPACTS
OF APPROACHING CIRRUS FROM THE WEST MAY BE LESS.
&&
.SHORT TERM...(TODAY THROUGH MONDAY NIGHT)
ISSUED AT 246 AM MDT SAT JUN 21 2014
A RIDGE OVER THE PLAINS WILL FLATTEN SOME TONIGHT. FLOW WILL BECOME
ZONAL ON SUNDAY AND THEN TURN NORTHWEST MONDAY/MONDAY NIGHT. A
SURFACE TROUGH WILL BE NEAR NORTHEAST COLORADO TODAY THROUGH
SUNDAY. A FRONT WILL MOVE INTO THE CENTRAL PLAINS SUNDAY
AFTERNOON. HIGH PRESSURE WILL BUILD INTO THE CENTRAL PLAINS SUNDAY
NIGHT AND CONTINUE THROUGH MONDAY NIGHT.
EARLY MORNING CONVECTION IS HANDLED WELL BY THE HRRR AND SHOULD
PERSIST ACROSS THE NORTHERN AND EASTERN ZONES TILL AROUND 16Z. POPS
WILL BE CHANCE AND LIKELY FOR THESE STORMS.
STORM INITIATION SHOULD TAKE PLACE NEAR THE SURFACE TROUGH THIS
AFTERNOON OVER EASTERN COLORADO AND EXTREME SOUTHWEST NEBRASKA.
STORMS WILL DRIFT EAST INTO THE REST OF THE FA DURING THE LATE
AFTERNOON/EVENING. SHEAR VALUES OF 30 TO 40 KTS WILL BE FAVORABLE
FOR STORMS TO BECOME SEVERE WITH LARGE HAIL AND DAMAGING WIND. CAPE
VALUES WILL RANGE FROM 1000 TO ALMOST 3000 J/KG WITH HIGHEST VALUES
OVER THE NORTHWEST FA. SUBSIDENCE WILL MOVE INTO THE FA LATE
SATURDAY NIGHT/SUNDAY MORNING SO POPS WILL BE NIL FOR THAT BRIEF
PERIOD SUNDAY MORNING. BY SUNDAY AFTERNOON THE FRONT WILL MOVE SOUTH
WITH CONVECTION ALONG AND BEHIND IT. INITIALLY STORM MOVEMENT IS
NEARLY PARALLEL TO THE FRONT IN THE AFTERNOON. HOWEVER THE MODELS
TAKE THE FRONT SOUTH ACROSS THE FA RATHER QUICKLY. BY EVENING STORM
MOVEMENT IS ALMOST PERPENDICULAR TO THE FRONT MINIMIZING ANY
TRAINING THUNDERSTORMS. PLAN TO KEEP LIKELY POPS ALONG AND BEHIND
THE FRONT WITH CHANCE POPS AHEAD OF THE FRONT. OVERNIGHT POPS WILL
DECREASE TO CHANCE AND SLIGHT CHANCE. ON MONDAY STORMS WILL DEVELOP
OVER THE HIGHER TERRAIN IN COLORADO AND DRIFT EAST. PLAN TO KEEP AT
LEAST CHANCE POPS FOR MONDAY AFTERNOON AND NIGHT.
MAX TEMPERATURES TODAY WILL RISE TO THE LOWER 90S. HIGH
TEMPERATURES SUNDAY RANGE FROM 85 TO 90. COOLER READINGS IN THE
UPPER 70S AND LOWER 80S ARE FORECAST FOR MONDAY. MIN TEMPERATURES
WILL VARY FROM THE UPPER 50S TO THE LOWER 60S.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 246 AM MDT SAT JUN 21 2014
AN UNSETTLED WEATHER PATTERN WILL CONTINUE FOR THE EXTENDED
PERIOD...WITH THE CHANCE FOR SHOWERS AND THUNDERSTORMS THROUGH
THURSDAY AND A POSSIBLE BREAK ON FRIDAY. SEVERAL SHORTWAVE TROUGHS
WILL MOVE THROUGH THE CWA...AND EVEN WITH A WEAK RIDGE MOVING OVER
THE CWA ON WEDNESDAY...SHORTWAVES EMBEDDED WITHIN THE FLOW WILL
CONTINUE THE CHANCE FOR SHOWERS AND THUNDERSTORMS. TUESDAY THROUGH
THURSDAY A LEE SURFACE LOW WILL EXIST OVER EASTERN COLORADO WITH A
QUASI STATIONARY SURFACE BOUNDARY EXTENDING SOUTHWARD FROM THE LOW.
INSTABILITY IS PRESENT OVER THE CWA THROUGHOUT THE EXTENDED...ALONG
WITH DECENT LOW LEVEL MOISTURE...AND FAVORABLE BULK SHEAR.
HOWEVER...TRYING TO TIME OUT THE PASSAGE OF EACH SHORTWAVE TROUGH
AND THE POSITION OF SURFACE BOUNDARIES IS A LITTLE DIFFICULT AT THIS
TIME...SO WILL HOLD OFF ON GETTING SPECIFIC WITH MENTION OF WHEN
SEVERE THUNDERSTORMS WILL OCCUR EVEN THOUGH IT COULD BE LIKELY
THROUGH THURSDAY. MODELS ARE NOT IN AGREEMENT WITH THE POSITION OR TIMING OF
THESE FEATURES AND MODEL SPREAD ONLY INCREASES FURTHER OUT INTO THE
EXTENDED.
FRIDAY IS KEPT DRY FOR NOW...EVEN THOUGH THE NEW RUN OF THE ECMWF HAS
A DEEP...NEGATIVELY TILTED TROUGH DIGGING FURTHER SOUTH INTO THE
SOUTHERN ROCKIES AND SOUTHWESTERN UNITED STATES. THE GFS DOES NOT
TAKE THE UPPER TROUGH THIS FAR SOUTH AND KEEPS IT IN THE PACIFIC
NORTHWEST BUT DEVELOPS A DRYLINE THURSDAY AFTERNOON THAT WAVERS BACK
WEST OVER THE CWA ON FRIDAY. AS PREVIOUSLY MENTIONED...WITH MODELS
BEING IN DISAGREEMENT THROUGHOUT THE EXTENDED...CONFIDENCE IN THE
EXTENDED FORECAST IS FAIRLY LOW. FOR THE MOST PART ACCEPTED THE
ALLBLEND...WITH A FEW MINOR ADJUSTMENTS HERE AND THERE. TEMPERATURES
WILL STEADILY INCREASE THROUGHOUT THE WEEK...WITH HIGHS IN THE LOW
TO MID 80S ON TUESDAY RISING INTO THE LOW TO MID 90S BY FRIDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 457 AM MDT SAT JUN 21 2014
CURRENT RADAR WITH RETURNS FROM THUNDERSTORMS, WITH ONE HEADING
FOR KMCK AND SHOULD BE THERE BY 12Z. ADDITIONAL STORMS ARE
EXPECTED LATER THIS AFTERNOON AND EVENING. SOME MVFR CONDITIONS
ARE POSSIBLE NEAR ANY STORMS, OTHERWISE VFR WILL PREVAIL AT BOTH
TERMINALS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...99
SHORT TERM...FS
LONG TERM...ALW
AVIATION...FS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
502 AM MDT SAT JUN 21 2014
.SHORT TERM...(TODAY THROUGH MONDAY NIGHT)
ISSUED AT 246 AM MDT SAT JUN 21 2014
A RIDGE OVER THE PLAINS WILL FLATTEN SOME TONIGHT. FLOW WILL BECOME
ZONAL ON SUNDAY AND THEN TURN NORTHWEST MONDAY/MONDAY NIGHT. A
SURFACE TROUGH WILL BE NEAR NORTHEAST COLORADO TODAY THROUGH
SUNDAY. A FRONT WILL MOVE INTO THE CENTRAL PLAINS SUNDAY
AFTERNOON. HIGH PRESSURE WILL BUILD INTO THE CENTRAL PLAINS SUNDAY
NIGHT AND CONTINUE THROUGH MONDAY NIGHT.
EARLY MORNING CONVECTION IS HANDLED WELL BY THE HRRR AND SHOULD
PERSIST ACROSS THE NORTHERN AND EASTERN ZONES TILL AROUND 16Z. POPS
WILL BE CHANCE AND LIKELY FOR THESE STORMS.
STORM INITIATION SHOULD TAKE PLACE NEAR THE SURFACE TROUGH THIS
AFTERNOON OVER EASTERN COLORADO AND EXTREME SOUTHWEST NEBRASKA.
STORMS WILL DRIFT EAST INTO THE REST OF THE FA DURING THE LATE
AFTERNOON/EVENING. SHEAR VALUES OF 30 TO 40 KTS WILL BE FAVORABLE
FOR STORMS TO BECOME SEVERE WITH LARGE HAIL AND DAMAGING WIND. CAPE
VALUES WILL RANGE FROM 1000 TO ALMOST 3000 J/KG WITH HIGHEST VALUES
OVER THE NORTHWEST FA. SUBSIDENCE WILL MOVE INTO THE FA LATE
SATURDAY NIGHT/SUNDAY MORNING SO POPS WILL BE NIL FOR THAT BRIEF
PERIOD SUNDAY MORNING. BY SUNDAY AFTERNOON THE FRONT WILL MOVE SOUTH
WITH CONVECTION ALONG AND BEHIND IT. INITIALLY STORM MOVEMENT IS
NEARLY PARALLEL TO THE FRONT IN THE AFTERNOON. HOWEVER THE MODELS
TAKE THE FRONT SOUTH ACROSS THE FA RATHER QUICKLY. BY EVENING STORM
MOVEMENT IS ALMOST PERPENDICULAR TO THE FRONT MINIMIZING ANY
TRAINING THUNDERSTORMS. PLAN TO KEEP LIKELY POPS ALONG AND BEHIND
THE FRONT WITH CHANCE POPS AHEAD OF THE FRONT. OVERNIGHT POPS WILL
DECREASE TO CHANCE AND SLIGHT CHANCE. ON MONDAY STORMS WILL DEVELOP
OVER THE HIGHER TERRAIN IN COLORADO AND DRIFT EAST. PLAN TO KEEP AT
LEAST CHANCE POPS FOR MONDAY AFTERNOON AND NIGHT.
MAX TEMPERATURES TODAY WILL RISE TO THE LOWER 90S. HIGH
TEMPERATURES SUNDAY RANGE FROM 85 TO 90. COOLER READINGS IN THE
UPPER 70S AND LOWER 80S ARE FORECAST FOR MONDAY. MIN TEMPERATURES
WILL VARY FROM THE UPPER 50S TO THE LOWER 60S.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 246 AM MDT SAT JUN 21 2014
AN UNSETTLED WEATHER PATTERN WILL CONTINUE FOR THE EXTENDED
PERIOD...WITH THE CHANCE FOR SHOWERS AND THUNDERSTORMS THROUGH
THURSDAY AND A POSSIBLE BREAK ON FRIDAY. SEVERAL SHORTWAVE TROUGHS
WILL MOVE THROUGH THE CWA...AND EVEN WITH A WEAK RIDGE MOVING OVER
THE CWA ON WEDNESDAY...SHORTWAVES EMBEDDED WITHIN THE FLOW WILL
CONTINUE THE CHANCE FOR SHOWERS AND THUNDERSTORMS. TUESDAY THROUGH
THURSDAY A LEE SURFACE LOW WILL EXIST OVER EASTERN COLORADO WITH A
QUASI STATIONARY SURFACE BOUNDARY EXTENDING SOUTHWARD FROM THE LOW.
INSTABILITY IS PRESENT OVER THE CWA THROUGHOUT THE EXTENDED...ALONG
WITH DECENT LOW LEVEL MOISTURE...AND FAVORABLE BULK SHEAR.
HOWEVER...TRYING TO TIME OUT THE PASSAGE OF EACH SHORTWAVE TROUGH
AND THE POSITION OF SURFACE BOUNDARIES IS A LITTLE DIFFICULT AT THIS
TIME...SO WILL HOLD OFF ON GETTING SPECIFIC WITH MENTION OF WHEN
SEVERE THUNDERSTORMS WILL OCCUR EVEN THOUGH IT COULD BE LIKELY
THROUGH THURSDAY. MODELS ARE NOT IN AGREEMENT WITH THE POSITION OR TIMING OF
THESE FEATURES AND MODEL SPREAD ONLY INCREASES FURTHER OUT INTO THE
EXTENDED.
FRIDAY IS KEPT DRY FOR NOW...EVEN THOUGH THE NEW RUN OF THE ECMWF HAS
A DEEP...NEGATIVELY TILTED TROUGH DIGGING FURTHER SOUTH INTO THE
SOUTHERN ROCKIES AND SOUTHWESTERN UNITED STATES. THE GFS DOES NOT
TAKE THE UPPER TROUGH THIS FAR SOUTH AND KEEPS IT IN THE PACIFIC
NORTHWEST BUT DEVELOPS A DRYLINE THURSDAY AFTERNOON THAT WAVERS BACK
WEST OVER THE CWA ON FRIDAY. AS PREVIOUSLY MENTIONED...WITH MODELS
BEING IN DISAGREEMENT THROUGHOUT THE EXTENDED...CONFIDENCE IN THE
EXTENDED FORECAST IS FAIRLY LOW. FOR THE MOST PART ACCEPTED THE
ALLBLEND...WITH A FEW MINOR ADJUSTMENTS HERE AND THERE. TEMPERATURES
WILL STEADILY INCREASE THROUGHOUT THE WEEK...WITH HIGHS IN THE LOW
TO MID 80S ON TUESDAY RISING INTO THE LOW TO MID 90S BY FRIDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 457 AM MDT SAT JUN 21 2014
CURRENT RADAR WITH RETURNS FROM THUNDERSTORMS, WITH ONE HEADING
FOR KMCK AND SHOULD BE THERE BY 12Z. ADDITIONAL STORMS ARE
EXPECTED LATER THIS AFTERNOON AND EVENING. SOME MVFR CONDITIONS
ARE POSSIBLE NEAR ANY STORMS, OTHERWISE VFR WILL PREVAIL AT BOTH
TERMINALS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...FS
LONG TERM...ALW
AVIATION...FS
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
626 AM CDT SAT JUN 21 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 346 AM CDT SAT JUN 21 2014
THE MCS ACROSS NORTHEAST COLORADO IS CLEARLY SHOWING CYCLONIC
ROTATION ON RADAR AND IS TRACKING EAST NORTHEAST TOWARD SWRN NEB
THIS MORNING. THE FORECAST TRACKS IT THROUGH SWRN NEB THIS MORNING
AND ALLOWS FOR DECAY BY 14Z-15Z. THE RAP AND HRRR MODELS DO NOT
HANDLE THIS FEATURE SO THE FORECAST IS HAND DRAWN FOR NOW WITH
SCATTERED POPS BECOMING ISOLATED.
AN ACTIVE SEVERE WEATHER DAY IS EXPECTED THIS AFTERNOON AND TONIGHT.
THE MODEL CONSENSUS SUGGESTS STORMS WOULD FIRE ACROSS NORTHWEST
NEBRASKA AROUND 21Z AND GROW UPSCALE EAST AND SOUTHEAST THROUGHOUT
THE EVENING HOURS. THE MODELS ARE STRUGGLING WITH TEMPERATURES AND
DEW POINTS. THE HRRR...GEMREG AND ECM SEEMED TO HAVE A BETTER HANDLE
ON DEW POINTS AND DEVELOP VERY HIGH SFC BASED CAPE ACROSS WRN/NCNTL
NEB. VALUES OF 3000-4000 J/KG DEVELOP WITH LITTLE OR NO CAP WHICH IS
CONSISTENT WITH THE AFTN CONDITIONS LATELY.
A STRONG MID LEVEL DISTURBANCE...CURRENTLY ACROSS NRN NEVADA WILL BE
CROSSING THE CNTL/NRN PLAINS LATE THIS AFTN AND A PACIFIC COLD FRONT
SWEEPS PART WAY THRU THE FCST AREA TONIGHT. THIS SETS UP A BROAD AND
WEAKLY CAPPED WARM SECTOR COVERING MOST OF THE FCST AREA THIS AFTN.
THE NAM AND RAP MODELS BACK THE SFC WINDS ACROSS NRN NEBRASKA THIS
AFTN HEIGHTENING THE SEVERE WEATHER THREAT. IN GENERAL WINDS ALOFT
ARE WEAK IN THE MODEL SOLNS BUT GIVEN THE STRENGTH OF THE UPPER
LEVEL DISTURBANCE ACROSS THE WRN U.S. THE SHEAR COULD BE STRONGER
TODAY THAN FRIDAY.
THERE IS A BROAD SPREAD IN BULK SHEAR SHOWN IN THE MODELS AT 00Z
THIS EVENING RANGING FROM LESS THAN 20 KT TO 35 KT AT BOTH NORTH
PLATTE AND VALENTINE. USING THE HIGHER VALUES SUGGESTS POTENTIAL FOR
SUPERCELL DEVELOPMENT AT BOTH LOCATIONS BUT THIS WOULD BE MORE
LIKELY ACROSS THE WEST WITH THE SYSTEM EVOLVING INTO A QLMCS AS IT
MOVES EAST INTO DEEPER MOISTURE ACROSS NCNTL NEB THIS EVENING. SPC
REMAINS UNCERTAIN ON HOW THIS SYSTEM WILL EVOLVE SINCE THE MODELS
SHOW A FULL SPECTRUM OF CONVECTIVE OPPORTUNITIES ACROSS THE BLACK
HILLS AND THE NEBRASKA PANHANDLE TODAY.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 346 AM CDT SAT JUN 21 2014
12Z SUNDAY AND BEYOND. THE FOCUS OF EXTENDED PERIODS...AT LEAST
INITIALLY...WILL BE ON THE TIMING AND LOCATION OF A FRONTAL
BOUNDARY POISED TO CROSS WESTERN AND NORTH CENTRAL NEBRASKA
SUNDAY. CONTRARY TO PREVIOUS MODEL RUNS...THE SOLUTIONS NOW SEEM
TO KEEP THE FRONT MOVING THROUGH THE CWA FAIRLY
PROGRESSIVELY...BUT THERE REMAINS CONSIDERABLE UNCERTAINTY ON HOW
SUNDAY WILL PLAY OUT...ESPECIALLY SINCE A FAIRLY SIGNIFICANT MCS
IS SHOWN TO DEVELOP SATURDAY NIGHT/EARLY SUNDAY ACROSS MUCH OF THE
CENTRAL SANDHILLS AND PROJECT EAST OVERNIGHT. THUS CONFIDENCE IS
SOMEWHAT LOWER THAN USUAL...BUT WHERE STORMS FIRE SUNDAY
AFTERNOON...STEEP LAPSE RATES...A MODERATE TO STRONGLY UNSTABLE
ATMOSPHERE AND SUFFICIENT SHEAR WOULD PROMOTE MULTI CELL UPDRAFTS
CAPABLE OF LARGE HAIL AND GUSTY WIND. GIVEN THE CURRENT
UNCERTAINTY...FELT THAT SUB 50 PERCENT POPS WERE ALL THAT WERE
NEEDED BEFORE 00Z MONDAY. THEREAFTER...THERE IS SOME AGREEMENT IN
THE SOLUTIONS THAT STORMS WILL FOCUS ACROSS OUR EASTERN AND
SOUTHERN ZONES...FOR THIS AREA WILL MAINTAIN HIGH END CHANCE
POPS...BUT NOT VENTURE INTO THE LIKELY REALM YET.
THE GREATEST CHANGE MADE TO THE INHERITED FORECAST IS NOTED ON
MONDAY AS THE SURFACE BOUNDARY IS NOW SHOWN TO BE WELL SOUTH AND
EAST OF THE CWA...THUS POPS WERE LOWERED TO ACCOUNT FOR THIS NEW
MODEL PROJECTION. WITHIN THE POST FRONTAL AIRMASS ON MONDAY AND
TUESDAY...TEMPERATURES WILL BE PLEASANT...WITH HIGHS GENERALLY IN
THE 70S FOR MOST LOCATIONS.
NORTHWEST FLOW ALOFT DEVELOPS ACROSS THE HIGH PLAINS EARLY NEXT WEEK
AS A NORTHERN PLAINS LOW DROPS SOUTH INTO THE EASTERN DAKOTAS...WITH
RIDGING NOSING INTO THE CENTRAL ROCKIES. WEAK EASTERLY UPSLOPE FLOW
WILL INTERACT WITH STRONG WARMING OFF THE HIGH PLAINS OF EASTERN
COLORADO/WYOMING TO PROMOTE STORM DEVELOPMENT MONDAY AFTERNOON. A
FEW OF THESE STORMS COULD DRIFT SOUTHEAST INTO WESTERN/SOUTHWEST
PORTIONS OF THE CWA WITH A STRONG OR LOW END SEVERE STORM POSSIBLE.
NORTHWEST FLOW CONTINUES TO DIRECT WEAK IMPULSES ACROSS THE HIGH
PLAINS INTO CENTRAL SANDHILLS...ADDITIONAL STORM CHANCES WILL BE
POSSIBLE THROUGH MID-WEEK. THEREAFTER...SUPPORT REMAINS FOR A
DEEPENING TROUGH ACROSS THE WESTERN CONUS...WHICH WOULD PROMOTE
SOUTHWEST FLOW ATOP THE CENTRAL PLAINS...SOUTHERLY SURFACE FLOW
RETURNS. THE PATTEN MAY RETURN ACTIVE LATE WEEK AS ADDITIONAL
ENERGY/EML IS DIRECTED NORTHEAST FROM THE WESTERN CONUS TROUGH TOWARD
THE CENTRAL PLAINS. AFTER HIGHS IN THE 70S EARLY NEXT
WEEK...TEMPERATURES GRADUALLY WARM INTO THE UPPER 80S TO LOWER 90S
BY LATE...LOWS TO REMAIN SEASONAL THROUGH THE EXTENDED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 623 AM CDT SAT JUN 21 2014
VFR IS EXPECTED ALL AREAS THROUGH 20Z. THEREAFTER SCATTERED STRONG
TO SEVERE TSTMS ARE EXPECTED TO DEVELOP IN THE PANHANDLE WHICH
WILL MOVE EAST AND BECOME NUMEROUS ACROSS NCNTL NEB BY 23Z-01Z.
STORM ACTIVITY WILL PROGRESS EAST THROUGHOUT THE EVENING AND EXIT
THE FCST AREA BY 06Z-12Z SUNDAY.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...JACOBS
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS BISMARCK ND
936 AM CDT SAT JUN 21 2014
.UPDATE...
ISSUED AT 926 AM CDT SAT JUN 21 2014
CURRENT SURFACE ANALYSIS PLACES FRONTAL BOUNDARY PUSHING THROUGH
ERN MT WHILE MOISTURE CONTINUES TO SLOWLY ADVECT TOWARDS S CTRL
ND. UPPER LEVEL ANALYSIS CONTINUES TO SHOW W/SWRLY FLOW WITH A
VARIETY OF WEAK WAVES MOVING THROUGH. MAIN CONCERN FOR MORNING
FORECAST IS SEVERE THREAT MAINLY OVER S CTRL INTO SERN ND. MORNING
GUIDANCE CONTINUES TO SHOW THE STRONGEST INSTABILITY MAINLY
SOUTH/EAST OF THE CWA...THOUGH STRONG ENOUGH INTO OUR AREA TO
BRING SEVERE CONCERNS. SHEAR INCREASES THROUGH THE AFTERNOON
(~40KTS 0-6KM BULK) AND WILL BE AMPLE FOR SUPERCELL DEVELOPMENT BY
AFTERNOON. LATEST GUIDANCE SUGGESTS MOST STORMS SHOULD FORM MAINLY
IN THE JAMES RIVER VALLEY REGION...THOUGH SOME CONCERN STILL EXITS
A BIT TOWARDS THE WEST. MORNING UPDATE WILL ADDRESS SEVERE
CONCERNS LATER TODAY AND HAVE ADJUSTED POPS WITH MORNING GUIDANCE.
UPDATES WILL BE OUT SHORTLY.
UPDATE ISSUED AT 626 AM CDT SAT JUN 21 2014
WEAK CONVECTION ONGOING ACROSS THE SOUTHWEST. DECIDED TO REMOVE
THUNDER FROM FORECAST FOR THE MORNING. OTHERWISE THIS BATCH OF
SHOWERS WILL TRACK THROUGH SOUTH CENTRAL NORTH DAKOTA. LATE THIS
AFTERNOON STRONGER STORMS WILL FORM ACROSS SOUTH CENTRAL NORTH
DAKOTA AS THE COLD FRONT PROGRESSES EAST.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 327 AM CDT SAT JUN 21 2014
LATEST SEVERAL HRRR RUNS HAVE INSISTED THAT SHOWER ACTIVITY OVER
FAR EASTERN MONTANA WILL HOLD TOGETHER...EVEN EXPANDING AND
STRENGTHENING...WILL SLIDE EASTWARD THIS MORNING AND THEN
DISSIPATE OVER SOUTHEASTERN NORTH DAKOTA. IT SEEMS REASONABLE
BASED ON THE PAST FEW HOURS OF SATELLITE AND RADAR INTERROGATION.
THE MORE PRESSING CONCERN IS FOR POSSIBLE SEVERE THUNDERSTORMS
THIS AFTERNOON AND EVENING SOUTH OF INTERSTATE 94. SPC SLID THEIR
CONVECTIVE OUTLOOK SLIGHT RISK TO THE NORTH THIS MORNING. ML CAPE
IS EXPECTED TO BE IN THE 1500 J/KG BALLPARK...AND SHEAR WILL BE
SUPPORTIVE OF SUPERCELLS.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 327 AM CDT SAT JUN 21 2014
THE EXTENDED PERIOD WILL BE MODERATELY ACTIVE FOR THIS TIME OF THE
YEAR WITH TWO FEATURES BRINGING PRECIPITATION TO THE REGION. FIRST
THE REMNANTS OF THE UPPER LOW ACROSS SASK/MANT WILL SWING SOUTH
THROUGH THE NORTHERN PLAINS MONDAY AND TUESDAY BRINGING SCATTERED
SHOWERS/THUNDERSTORMS TO THE REGION. SUFFICIENT INSTABILITY EXISTS
FOR ROUTINE THUNDERSTORMS WITH NOTHING SCREAMING SEVERE POTENTIAL AT
THIS TIME. A CHANGE TO COOLER WEATHER ALSO IS ANTICIPATED AS THIS
LOW WILL BRING COOLER H850 TEMPS WITH IT. FOLLOWING THIS THE
ECMWF/GFS BOTH ARE BRINGING EASTERN PACIFIC SHORTWAVE ENERGY INTO
WESTERN NORTH AMERICA AND ARE CARVING OUT A LONGWAVE TROUGH ACROSS
THE WESTERN US. THE EUROPEAN SEEMS TO BE MORE AGGRESSIVE WITH A
FASTER AND DEEPER TROUGH. EITHER WAY THE RESULT WILL BE A SOUTHWEST
FLOW ALOFT...WITH AN OPENING TO GULF MOISTURE AND EVENTUALLY A MORE
ACTIVE THUNDERSTORM PATTERN FOR THE LAST WEEK OF JUNE. USING
ALLBLEND GUIDANCE RESULTS IN A CHANCE OF THUNDERSTORMS WEDNESDAY
TROUGH FRIDAY WITH NORMAL TO ABOVE NORMAL TEMPERATURES RETURNING BY
THE END OF THE WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 626 AM CDT SAT JUN 21 2014
AN AREA OF SHOWERS SHOULD MOVE EASTWARD FROM KDIK TO KBIS AND
KJMS. ANOTHER ROUND OF STRONGER THUNDERSTORMS SHOULD FORM AROUND
21Z NEAR KBIS/KJMS. KISN/KMOT SHOULD REMAIN DRY AND VFR.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JJS
SHORT TERM...SCHECK
LONG TERM...WAA
VIATION...WAA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
630 AM CDT SAT JUN 21 2014
.UPDATE...
ISSUED AT 626 AM CDT SAT JUN 21 2014
WEAK CONVECTION ONGOING ACROSS THE SOUTHWEST. DECIDED TO REMOVE
THUNDER FROM FORECAST FOR THE MORNING. OTHERWISE THIS BATCH OF
SHOWERS WILL TRACK THROUGH SOUTH CENTRAL NORTH DAKOTA. LATE THIS
AFTERNOON STRONGER STORMS WILL FORM ACROSS SOUTH CENTRAL NORTH
DAKOTA AS THE COLD FRONT PROGRESSES EAST.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 327 AM CDT SAT JUN 21 2014
LATEST SEVERAL HRRR RUNS HAVE INSISTED THAT SHOWER ACTIVITY OVER
FAR EASTERN MONTANA WILL HOLD TOGETHER...EVEN EXPANDING AND
STRENGTHENING...WILL SLIDE EASTWARD THIS MORNING AND THEN
DISSIPATE OVER SOUTHEASTERN NORTH DAKOTA. IT SEEMS REASONABLE
BASED ON THE PAST FEW HOURS OF SATELLITE AND RADAR INTERROGATION.
THE MORE PRESSING CONCERN IS FOR POSSIBLE SEVERE THUNDERSTORMS
THIS AFTERNOON AND EVENING SOUTH OF INTERSTATE 94. SPC SLID THEIR
CONVECTIVE OUTLOOK SLIGHT RISK TO THE NORTH THIS MORNING. ML CAPE
IS EXPECTED TO BE IN THE 1500 J/KG BALLPARK...AND SHEAR WILL BE
SUPPORTIVE OF SUPERCELLS.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 327 AM CDT SAT JUN 21 2014
THE EXTENDED PERIOD WILL BE MODERATELY ACTIVE FOR THIS TIME OF THE
YEAR WITH TWO FEATURES BRINGING PRECIPITATION TO THE REGION. FIRST
THE REMNANTS OF THE UPPER LOW ACROSS SASK/MANT WILL SWING SOUTH
THROUGH THE NORTHERN PLAINS MONDAY AND TUESDAY BRINGING SCATTERED
SHOWERS/THUNDERSTORMS TO THE REGION. SUFFICIENT INSTABILITY EXISTS
FOR ROUTINE THUNDERSTORMS WITH NOTHING SCREAMING SEVERE POTENTIAL AT
THIS TIME. A CHANGE TO COOLER WEATHER ALSO IS ANTICIPATED AS THIS
LOW WILL BRING COOLER H850 TEMPS WITH IT. FOLLOWING THIS THE
ECMWF/GFS BOTH ARE BRINGING EASTERN PACIFIC SHORTWAVE ENERGY INTO
WESTERN NORTH AMERICA AND ARE CARVING OUT A LONGWAVE TROUGH ACROSS
THE WESTERN US. THE EUROPEAN SEEMS TO BE MORE AGGRESSIVE WITH A
FASTER AND DEEPER TROUGH. EITHER WAY THE RESULT WILL BE A SOUTHWEST
FLOW ALOFT...WITH AN OPENING TO GULF MOISTURE AND EVENTUALLY A MORE
ACTIVE THUNDERSTORM PATTERN FOR THE LAST WEEK OF JUNE. USING
ALLBLEND GUIDANCE RESULTS IN A CHANCE OF THUNDERSTORMS WEDNESDAY
TROUGH FRIDAY WITH NORMAL TO ABOVE NORMAL TEMPERATURES RETURNING BY
THE END OF THE WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 626 AM CDT SAT JUN 21 2014
AN AREA OF SHOWERS SHOULD MOVE EASTWARD FROM KDIK TO KBIS AND
KJMS. ANOTHER ROUND OF STRONGER THUNDERSTORMS SHOULD FORM AROUND
21Z NEAR KBIS/KJMS. KISN/KMOT SHOULD REMAIN DRY AND VFR.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...WAA
SHORT TERM...SCHECK
LONG TERM...WAA
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1051 AM EDT SAT JUN 21 2014
.SYNOPSIS...
AN UPPER RIDGE WILL CONTINUE TO BREAK DOWN TODAY RESULTING IN
WEAKENING HIGH PRESSURE CURRENTLY IN PLACE OVER THE AREA. THIS
SHOULD YIELD A GREATER COVERAGE OF SHOWERS AND THUNDERSTORMS ACROSS
THE AREA THROUGH EARLY NEXT WEEK. A TYPICAL WARM SUMMERLIKE PATTERN
WILL CONTINUE THROUGH NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
1000 AM UPDATE...SHOWERS THAT FORMED IN UPSLOPE FLOW OVER UPPER EAST
TN...AND POSSIBLY AIDED BY MESOSCALE RIPPLES ROUNDING THE UPPER
RIDGE...HAVE NOW MOVED INTO OUR NRN MTN ZONES. AS THE RIPPLES MOVE
EAST OF THE MTNS DOWNSLOPE FLOW WILL LIKELY WIPE OUT THE CURRENT
ACTIVITY...BUT NEW CELLS SHOULD PROPAGATE EWD OUT OF THE
FOOTHILLS...MUCH LIKE WHAT WE EXPERIENCED YESTERDAY. THIS IDEA ALSO
BACKED UP BY THE LATEST HRRR TRENDS...AND TO SOME EXTENT THE 12Z
NAM. THE NEW NAM ALSO STILL FEATURES BEST INSTBY IN THE NC PIEDMONT
WHICH ACTUALLY PEAKS AT MIDDAY...WITH LAPSE RATES DIMINISHING LATER
IN THE AFTN. HOWEVER UNDER CONTINUED HEATING SOME ACTIVITY WILL
LIKELY BE ABLE TO CONTINUE UNTIL AFTER SUNSET AS IT TYPICALLY DOES.
SO WHILE ADJUSTMENTS HAVE BEEN MADE TO BETTER REFLECT THE
PROPAGATION INTO THE PIEDMONT...PEAK POPS ARE THE SAME. WILL ADJUST
TEMPS PER LATEST OBS.
PREVIOUS DISCUSSION...
AS OF 300 AM EDT SATURDAY...BROAD YET WEAK UPPER RIDGE CONTINUES TO
SLOWLY RETROGRADE WESTWARD ALLOWING FOR CONTINUED NORTHWEST FLOW
ALOFT FOR THE SOUTHERN APPS. MEANWHILE AT THE SURFACE...WEAK LEE
SIDE TROF WILL ONCE AGAIN BE PRESENT ALONG THE MIDATLANTIC COASTLINE
WITH A WEAK COASTAL LOW DEVELOPING BY LATE MORNING TO EARLY
AFTERNOON. EXPECTING LESS CONVECTIVE COVERAGE OVERALL TODAY WITH THE
MAJORITY OF THE ACTIVITY TIED TO THE NC PIEDMONT WHERE INSTABILITY
WILL BE HIGHEST...AND WEAK UPPER H5 IMPULSES PASS THROUGH THE MEAN
FLOW. GUIDANCE INDICATES A RELATIVELY STABLE AIRMASS WILL RESIDE
ACROSS NORTHEAST GA AND THE CENTRAL/WESTERN UPSTATE WILL LITTLE TO
NO FORCING AVAILABLE FOR CONVECTION. AS MENTIONED ABOVE...PROFILES
WILL BE MOST SUPPORTIVE OF CONVECTION ACROSS THE NC
PIEDMONT...ESPECIALLY ALONG THE I40 CORRIDOR WHERE UPWARDS OF
1500J/KG SBCAPE WILL RESIDE. CANNOT RULE OUT A FEW SEVERE
THUNDERSTORMS IN THIS REGION DESPITE POOR MID LEVEL LAPSE RATES.
THAT SAID...PRIMARY SEVERE THREATS WILL BE DAMAGING DOWNBURST WINDS
AND HEAVY RAINFALL AS VERY MOIST PROFILES WATER LOAD UPDRAFTS
LEADING TO ENHANCED REGIONS OF DCAPE. POPS WILL RAMP UP BY MID
AFTERNOON TO LOW END LIKELY LEVELS EAST OF I77 IN THE NORTHERN NC
PIEDMONT...TAPERING TO SLIGHT CHANCE POPS FURTHER SOUTH AND
WEST...BEFORE ALL POPS FALL OFF INTO THE OVERNIGHT AS HEATING IS
LOST. TEMPERATURES THROUGH THE NEAR TERM PERIOD WILL ONCE AGAIN BE
ABOVE NORMAL AS SUMMERTIME DIURNAL PATTERN CONTINUES.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 AM EDT SATURDAY...H5 HEIGHTS WILL GRADUALLY RISE OVER THE
SE CONUS ON SUNDAY AS AN UPPER RIDGE AXIS SHIFTS EASTWARD INTO THE
CENTRAL STATES AND POSITIVELY TILTED UPPER TROUGH AXIS MOVES OFF THE
EASTERN SEABOARD. MONDAY...AN UPPER RIDGE WILL QUICKLY BUILD IN
ACROSS THE REGION FROM THE WEST WITH ITS AXIS CROSSING THE FORECAST
AREA BY MON EVENING/NIGHT.
AT THE SURFACE...EXPECT N/NELY FLOW TO PERSIST ACROSS THE REGION ON
SUNDAY AS A BROAD AREA OF SURFACE LOW DRIFTS EAST AWAY FROM THE
CAROLINAS COAST. MODEL SOUNDINGS SUGGEST THAT PROFILES SHOULD REMAIN
RATHER DRY DUE TO PREVAILING DOWNSLOPE NORTHERLY FLOW KEEPING THE
LCL ELEVATED ABOVE 6K FT. IN RESPONSE TO THIS...MODELS KEEP THE AREA
MOSTLY DRY THROUGH THE AFTERNOON. HOWEVER...CONDITIONS SHOULD CHANGE
DRAMATICALLY BY SUN EVENING/NIGHT AS THE REGION WILL BE UNDER THE SW
PERIPHERY OF THE BERMUDA HIGH BRINGING E/SELY FLOW TO THE FORECAST
AREA. IN RESPONSE TO THIS PATTERN...THE NAM AND GFS DEVELOP UPSLOPE
INDUCED SHOWERS AND THUNDERSTORMS AREAS ALONG AND EAST OF THE BLUE
RIDGE BY SUN EVENING AND CONTINUE THROUGH THE OVERNIGHT HOURS.
HENCE...HAVE MENTIONED POPS IN THE 30/40S OVER THE AFOREMENTIONED
AREAS SUN NIGHT.
MONDAY...MODELS AGREE THAT THE REGION WILL BE UNDER THE CONFLUENT
SSW/SSELY FLOW REGIME. WITH THE COMBINATION OF INCREASING
GULF/ATLANTIC MOISTURE ADVECTION...LLVL CONVERGENCE AND DIURNAL
INSTABILITY...WE WILL SEE WIDESPREAD CONVECTION ONGOING THROUGH LATE
EVENING/NIGHT. THIS PATTERN IS SUSCEPTIBLE TO HEAVY RAINFALL WITH
LOCALIZED FLASH FLOODING IN TRAINING CELLS. WITH THAT SAID..HAVE
INCREASED THE POPS INTO THE 40/50S RANGE ACROSS MUCH OF THE REGION.
TEMPERATURES WILL START OUT 2-3 DEGREES ABOVE NORMAL SUN AND COOL
DOWN TO NEAR NORMAL RANGE BY MONDAY.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 200 AM EDT SAT...THE LATEST GLOBAL MODELS CONTINUE TO
ADVERTISE THAT AN UPPER RIDGE WILL BREAK DOWN OVER THE SE CONUS TUE
IN RESPONSE TO AN APPROACHING SHORTWAVE TROUGH FROM THE CENTRAL
STATES. THE GFS IS SHARPER WITH THIS WAVE PASSING JUST TO OUR NORTH
ON LATE WED/EARLY THU WHILE THE ECMWF IS WEAKER AND TAKES IT INTO
THE OHIO VALLEY...LEAVING OUR AREA UNDER NEARLY ZONAL FLOW ALOFT.
BOTH MODELS THEN BUILD UPPER RIDGE OVER THE AREA BY FRI.
AT THE SURFACE...BERMUDA HIGH WILL CONTINUE TO INFLUENCE THE AREA
THROUGH MUCH OF THE MEDIUM RANGE PERIOD WITH A FRONTAL BOUNDARY
ASSOCIATED WITH THE UPPER WAVE CROSSING THE FORECAST AREA LATE WED.
AS FOR THE SENSIBLE WEATHER...WE WILL CONTINUE TO SEE DIURNALLY
DRIVEN PULSE TYPE STORMS ACROSS MUCH OF THE AREA ON EACH DAY GIVEN
WEAKLY SHEARED ENVIRONMENT...DIURNAL INSTABILITY AND GULF MOISTURE
ADVECTION IN PREDOMINANT S/SWLY FLOW ALOFT. WITH INCREASING SHEAR
ALOFT IN LIGHT OF FROPA ON WED...WE MAY SEE BETTER ORGANIZED LINE OF
STORMS PRODUCING DAMAGING WIND GUSTS AND LARGE HAIL.
TEMPERATURES WILL STAY NEAR NORMAL RANGE THROUGH THE PERIOD.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
AT KCLT...VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD WITH
THE EXCEPTION OF POSSIBLE AFTERNOON MVFR TSRA. INTRODUCED LOW VFR
DIURNAL CU CIG AT 19Z WITH A 4HR TEMPO FOR AFTERNOON TSRA INCLUDING
A 4SM VISB. BKN LOW VFR CIGS PREVAIL THROUGH 08Z BEFORE SCT
OUT...EVENTUALLY GIVING WAY TO HIGH LEVEL CIRRUS. WINDS WILL REMAIN
OUT OF THE WEST NORTHWEST THROUGH MID/LATE MORNING BEFORE LEE SIDE
TROF ONCE AGAIN VEERS WINDS FURTHER NORTH FOR THE REMAINDER OF THE
PERIOD.
ELSEWHERE...MUCH THE SAME AS KCLT ABOVE AS VFR CONDITIONS WILL
PREVAIL WITH THE EXCEPTION OF MVFR TSRA IN THE AFTERNOON FOR THE NC
SITES. CONVECTION ON SATURDAY WILL LIKELY REMAIN TIED TO THE
TERRAIN...AND THE NC PIEDMONT. THUS FEATURE TEMPOS FOR MVFR TSRA AT
KAVL AND KHKY WHILE ONLY INCLUDING VCTS MENTION AT THE SC SITES.
REINTRODUCED LIFR CIGS WITH IFR VISB AT KAVL NEAR THE END OF THE
PERIOD BASED UPON PERSISTENCE OF THE PATTERN. WINDS THROUGH THE
PERIOD WILL REMAIN NORTHERLY AND WILL INCREASE TO AROUND 8-10KTS
WHEN MIXING IS AT ITS GREATEST DURING PEAK HEATING SATURDAY
AFTERNOON.
OUTLOOK...ISOLATED TO SCATTERED AFTERNOON AND EVENING THUNDERSTORMS
ARE EXPECTED AGAIN SUNDAY...WITH THE GREATEST COVERAGE ACROSS THE
MTNS AND NC PIEDMONT. RESTRICTIONS MAY OCCUR DURING TSRA AND ALSO IN
THE MTN VALLEYS EACH MORNING WHERE LOW CLOUDS AND FOG MAY FORM OVER
AREAS OF RECENT RAINFALL.
CONFIDENCE TABLE...
15-21Z 21-03Z 03-09Z 09-15Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 100% MED 79% MED 62%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JOH
NEAR TERM...CDG/WIMBERLEY
SHORT TERM...JOH
LONG TERM...JOH
AVIATION...CDG/WIMBERLEY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1011 AM EDT SAT JUN 21 2014
.SYNOPSIS...
AN UPPER RIDGE WILL CONTINUE TO BREAK DOWN TODAY RESULTING IN
WEAKENING HIGH PRESSURE CURRENTLY IN PLACE OVER THE AREA. THIS
SHOULD YIELD A GREATER COVERAGE OF SHOWERS AND THUNDERSTORMS ACROSS
THE AREA THROUGH EARLY NEXT WEEK. A TYPICAL WARM SUMMERLIKE PATTERN
WILL CONTINUE THROUGH NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
1000 AM UPDATE...SHOWERS THAT FORMED IN UPSLOPE FLOW OVER UPPER EAST
TN...AND POSSIBLY AIDED BY MESOSCALE RIPPLES ROUNDING THE UPPER
RIDGE...HAVE NOW MOVED INTO OUR NRN MTN ZONES. AS THE RIPPLES MOVE
EAST OF THE MTNS DOWNSLOPE FLOW WILL LIKELY WIPE OUT THE CURRENT
ACTIVITY...BUT NEW CELLS SHOULD PROPAGATE EWD OUT OF THE
FOOTHILLS...MUCH LIKE WHAT WE EXPERIENCED YESTERDAY. THIS IDEA ALSO
BACKED UP BY THE LATEST HRRR TRENDS...AND TO SOME EXTENT THE 12Z
NAM. THE NEW NAM ALSO STILL FEATURES BEST INSTBY IN THE NC PIEDMONT
WHICH ACTUALLY PEAKS AT MIDDAY...WITH LAPSE RATES DIMINISHING LATER
IN THE AFTN. HOWEVER UNDER CONTINUED HEATING SOME ACTIVITY WILL
LIKELY BE ABLE TO CONTINUE UNTIL AFTER SUNSET AS IT TYPICALLY DOES.
SO WHILE ADJUSTMENTS HAVE BEEN MADE TO BETTER REFLECT THE
PROPAGATION INTO THE PIEDMONT...PEAK POPS ARE THE SAME. WILL ADJUST
TEMPS PER LATEST OBS.
PREVIOUS DISCUSSION...
AS OF 300 AM EDT SATURDAY...BROAD YET WEAK UPPER RIDGE CONTINUES TO
SLOWLY RETROGRADE WESTWARD ALLOWING FOR CONTINUED NORTHWEST FLOW
ALOFT FOR THE SOUTHERN APPS. MEANWHILE AT THE SURFACE...WEAK LEE
SIDE TROF WILL ONCE AGAIN BE PRESENT ALONG THE MIDATLANTIC COASTLINE
WITH A WEAK COASTAL LOW DEVELOPING BY LATE MORNING TO EARLY
AFTERNOON. EXPECTING LESS CONVECTIVE COVERAGE OVERALL TODAY WITH THE
MAJORITY OF THE ACTIVITY TIED TO THE NC PIEDMONT WHERE INSTABILITY
WILL BE HIGHEST...AND WEAK UPPER H5 IMPULSES PASS THROUGH THE MEAN
FLOW. GUIDANCE INDICATES A RELATIVELY STABLE AIRMASS WILL RESIDE
ACROSS NORTHEAST GA AND THE CENTRAL/WESTERN UPSTATE WILL LITTLE TO
NO FORCING AVAILABLE FOR CONVECTION. AS MENTIONED ABOVE...PROFILES
WILL BE MOST SUPPORTIVE OF CONVECTION ACROSS THE NC
PIEDMONT...ESPECIALLY ALONG THE I40 CORRIDOR WHERE UPWARDS OF
1500J/KG SBCAPE WILL RESIDE. CANNOT RULE OUT A FEW SEVERE
THUNDERSTORMS IN THIS REGION DESPITE POOR MID LEVEL LAPSE RATES.
THAT SAID...PRIMARY SEVERE THREATS WILL BE DAMAGING DOWNBURST WINDS
AND HEAVY RAINFALL AS VERY MOIST PROFILES WATER LOAD UPDRAFTS
LEADING TO ENHANCED REGIONS OF DCAPE. POPS WILL RAMP UP BY MID
AFTERNOON TO LOW END LIKELY LEVELS EAST OF I77 IN THE NORTHERN NC
PIEDMONT...TAPERING TO SLIGHT CHANCE POPS FURTHER SOUTH AND
WEST...BEFORE ALL POPS FALL OFF INTO THE OVERNIGHT AS HEATING IS
LOST. TEMPERATURES THROUGH THE NEAR TERM PERIOD WILL ONCE AGAIN BE
ABOVE NORMAL AS SUMMERTIME DIURNAL PATTERN CONTINUES.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 AM EDT SATURDAY...H5 HEIGHTS WILL GRADUALLY RISE OVER THE
SE CONUS ON SUNDAY AS AN UPPER RIDGE AXIS SHIFTS EASTWARD INTO THE
CENTRAL STATES AND POSITIVELY TILTED UPPER TROUGH AXIS MOVES OFF THE
EASTERN SEABOARD. MONDAY...AN UPPER RIDGE WILL QUICKLY BUILD IN
ACROSS THE REGION FROM THE WEST WITH ITS AXIS CROSSING THE FORECAST
AREA BY MON EVENING/NIGHT.
AT THE SURFACE...EXPECT N/NELY FLOW TO PERSIST ACROSS THE REGION ON
SUNDAY AS A BROAD AREA OF SURFACE LOW DRIFTS EAST AWAY FROM THE
CAROLINAS COAST. MODEL SOUNDINGS SUGGEST THAT PROFILES SHOULD REMAIN
RATHER DRY DUE TO PREVAILING DOWNSLOPE NORTHERLY FLOW KEEPING THE
LCL ELEVATED ABOVE 6K FT. IN RESPONSE TO THIS...MODELS KEEP THE AREA
MOSTLY DRY THROUGH THE AFTERNOON. HOWEVER...CONDITIONS SHOULD CHANGE
DRAMATICALLY BY SUN EVENING/NIGHT AS THE REGION WILL BE UNDER THE SW
PERIPHERY OF THE BERMUDA HIGH BRINGING E/SELY FLOW TO THE FORECAST
AREA. IN RESPONSE TO THIS PATTERN...THE NAM AND GFS DEVELOP UPSLOPE
INDUCED SHOWERS AND THUNDERSTORMS AREAS ALONG AND EAST OF THE BLUE
RIDGE BY SUN EVENING AND CONTINUE THROUGH THE OVERNIGHT HOURS.
HENCE...HAVE MENTIONED POPS IN THE 30/40S OVER THE AFOREMENTIONED
AREAS SUN NIGHT.
MONDAY...MODELS AGREE THAT THE REGION WILL BE UNDER THE CONFLUENT
SSW/SSELY FLOW REGIME. WITH THE COMBINATION OF INCREASING
GULF/ATLANTIC MOISTURE ADVECTION...LLVL CONVERGENCE AND DIURNAL
INSTABILITY...WE WILL SEE WIDESPREAD CONVECTION ONGOING THROUGH LATE
EVENING/NIGHT. THIS PATTERN IS SUSCEPTIBLE TO HEAVY RAINFALL WITH
LOCALIZED FLASH FLOODING IN TRAINING CELLS. WITH THAT SAID..HAVE
INCREASED THE POPS INTO THE 40/50S RANGE ACROSS MUCH OF THE REGION.
TEMPERATURES WILL START OUT 2-3 DEGREES ABOVE NORMAL SUN AND COOL
DOWN TO NEAR NORMAL RANGE BY MONDAY.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 200 AM EDT SAT...THE LATEST GLOBAL MODELS CONTINUE TO
ADVERTISE THAT AN UPPER RIDGE WILL BREAK DOWN OVER THE SE CONUS TUE
IN RESPONSE TO AN APPROACHING SHORTWAVE TROUGH FROM THE CENTRAL
STATES. THE GFS IS SHARPER WITH THIS WAVE PASSING JUST TO OUR NORTH
ON LATE WED/EARLY THU WHILE THE ECMWF IS WEAKER AND TAKES IT INTO
THE OHIO VALLEY...LEAVING OUR AREA UNDER NEARLY ZONAL FLOW ALOFT.
BOTH MODELS THEN BUILD UPPER RIDGE OVER THE AREA BY FRI.
AT THE SURFACE...BERMUDA HIGH WILL CONTINUE TO INFLUENCE THE AREA
THROUGH MUCH OF THE MEDIUM RANGE PERIOD WITH A FRONTAL BOUNDARY
ASSOCIATED WITH THE UPPER WAVE CROSSING THE FORECAST AREA LATE WED.
AS FOR THE SENSIBLE WEATHER...WE WILL CONTINUE TO SEE DIURNALLY
DRIVEN PULSE TYPE STORMS ACROSS MUCH OF THE AREA ON EACH DAY GIVEN
WEAKLY SHEARED ENVIRONMENT...DIURNAL INSTABILITY AND GULF MOISTURE
ADVECTION IN PREDOMINANT S/SWLY FLOW ALOFT. WITH INCREASING SHEAR
ALOFT IN LIGHT OF FROPA ON WED...WE MAY SEE BETTER ORGANIZED LINE OF
STORMS PRODUCING DAMAGING WIND GUSTS AND LARGE HAIL.
TEMPERATURES WILL STAY NEAR NORMAL RANGE THROUGH THE PERIOD.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
AT KCLT...VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD WITH
THE EXCEPTION OF POSSIBLE AFTERNOON MVFR TSRA. INITIALIZED TAF
UNDER BKN MID LEVEL STRATUS THROUGH MID/LATE MORNING WHERE
STEEPENING LAPSE RATES ALLOW FOR DIURNAL CU DEVELOPMENT. INTRODUCED
LOW VFR CU CIG AT 19Z WITH A 4HR TEMPO FOR AFTERNOON TSRA INCLUDING
A 4SM VISB. BKN LOW VFR CIGS PREVAIL THROUGH 08Z BEFORE SCT
OUT...EVENTUALLY GIVING WAY TO HIGH LEVEL CIRRUS. WINDS WILL REMAIN
OUT OF THE WEST NORTHWEST THROUGH MID/LATE MORNING BEFORE LEE SIDE
TROF ONCE AGAIN VEERS WINDS FURTHER NORTH FOR THE REMAINDER OF THE
PERIOD.
ELSEWHERE...MUCH THE SAME AS KCLT ABOVE AS VFR CONDITIONS WILL
PREVAIL WITH THE EXCEPTION OF MVFR TSRA IN THE AFTERNOON FOR THE NC
SITES. CONVECTION ON SATURDAY WILL LIKELY REMAIN TIED TO THE
TERRAIN...AND THE NC PIEDMONT. THUS FEATURE TEMPOS FOR MVFR TSRA AT
KAVL AND KHKY WHILE ONLY INCLUDING VCTS MENTION AT THE SC SITES.
REINTRODUCED LIFR CIGS WITH IFR VISB AT KAVL NEAR THE END OF THE
PERIOD BASED UPON PERSISTENCE OF THE PATTERN. WINDS THROUGH THE
PERIOD WILL REMAIN NORTHERLY AND WILL INCREASE TO AROUND 8-10KTS
WHEN MIXING IS AT ITS GREATEST DURING PEAK HEATING SATURDAY
AFTERNOON.
OUTLOOK...ISOLATED TO SCATTERED AFTERNOON AND EVENING THUNDERSTORMS
ARE EXPECTED THIS WEEKEND...WITH THE GREATEST COVERAGE ACROSS THE
MTNS AND NC PIEDMONT. RESTRICTIONS MAY OCCUR DURING TSRA AND ALSO IN
THE MTN VALLEYS EACH MORNING WHERE LOW CLOUDS AND FOG MAY FORM OVER
AREAS OF RECENT RAINFALL.
CONFIDENCE TABLE...
14-20Z 20-02Z 02-08Z 08-14Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 92% HIGH 100% MED 77% LOW 57%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JOH
NEAR TERM...CDG/WIMBERLEY
SHORT TERM...JOH
LONG TERM...JOH
AVIATION...CDG
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
847 AM CDT SAT JUN 21 2014
.MESOSCALE UPDATE...
SURFACE FRONT JUST OUR NORTH WITH SURFACE DEWPOINTS AROUND 70
ACROSS KENTUCKY AND LOWER 70S IN MOST OF MIDDLE TENNESSEE.
CONVECTION CURRENTLY FIRING IN KENTUCKY NEARING LAKE CUMBERLAND
WILL DROP DOWN INTO THE UPPER CUMBERLAND AREA NEXT HOUR OR TWO.
LATEST RUC RUN HAS MUCH DRIER AIR THROUGH THE MID LEVELS WORKING
DOWN ACROSS MOST OF KENTUCKY BY 16Z. THIS DRIER AIR IN THE MID
LEVELS WILL WORK SOUTHWARD AS WE GO THROUGH THE DAY WHILE SURFACE
DEWPOINTS REMAIN AROUND 70. THINK NORTHWEST MIDDLE TENNESSEE WILL
HAVE THE LEAST CHANCE OF GETTING CONVECTION THIS MORNING WITH
CONVECTION CONFINED MAINLY TO THE EASTERN MIDDLE TENNESSEE AND
PLATEAU DURING THE AFTERNOON. TEMPS LOOK ON TRACK.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
BOYD
01
AREA FORECAST DISCUSSION...UPDATED
NWS NASHVILLE TN
533 AM CDT SAT JUN 21 2014
.UPDATE...FOR 12Z AVIATION DISCUSSION.
&&
.AVIATION...12Z AVIATION DISCUSSION.
SOME MVFR TO IFR FOG MAY PERSIST THRU 21/14Z CKV...OTHERWISE PER DIURNAL
HEATING INFLUENCES...VFR SCT CU...SCT/BKN CI...THRU 22/02Z. DESPITE DRIER
AIR TRYING TO WORK INTO MID STATE...SHORT RANGE MODELS SHOWING BEST POTENTIAL
OF ISO/SCT SHWR/TSTM ACTIVITY CSV 21/17Z-22/02Z PER DIURNAL INFLUENCES ALSO...
AND WITH ACTUAL LOCATION UNCERTAINTY DEVELOPMENT...MENTIONED VCTS. SCT/BKN CI
POSSIBLE AFTER 22/02Z...WITH MVFR FOG FORMATION CKV/CSV PER LOW LEVEL MOISTURE
POOLING POTENTIAL...LIGHT WINDS...AND CLR SKIES AFTER 22/08Z. NWLY SFC WINDS
AROUND 5KT OR LESS EXPECTED THRU 22/12Z ALSO.
&&
.PREV DISCUSSION.../ISSUED 344 AM CDT SAT JUN 21 2014/
DISCUSSION...
HELLO FOLKS....SUMMERTIME BEGINS THIS MORNING AT 551 AM...ENJOY!
AND NOW ON TO THE WEATHER.......
NW FLOW ALOFT IS IN PLACE AS THE UPPER HIGH NOW RESIDES OVER THE
NORTHERN GULF AND IS RATHER WEAK. IN THE LOWER LEVELS...WEAK HIGH
PRESSURE IS IN CONTROL. LOW LEVEL FLOW WILL GRAVITATE TOWARD A DRIER
NORTHERLY FLOW BY AFTERNOON. CONVECTIVE CHARTS SHOW THE BETTER CAP
EROSION ACROSS THE SOUTH WITH APPRECIABLE CAPE THERE AS WELL. THE
PLAN FOR TODAY WILL BE TO CARRY A SLIGHT CHANCE OF SHOWERS AND TSTMS
NORTH IN THE MORNING. ELSEWHERE...WILL CARRY THE LOW POPS THROUGH
THE DAY. HRRR SHOWING SOME DEVELOPMENT BY 17Z OR SO. OTW...THE DRIER
AIR WILL WIN OUT TOWARD EVENING. FOR TONIGHT AND SUNDAY...LITTLE
OR NO POPS WILL BE INCLUDED. PCLDY TO MOSTLY CLEAR SKIES ARE
EXPECTED FOR SUNDAY INTO SUNDAY NT. THE NEXT CHANCE OF SHOWERS AND
TSTMS WILL BE ON MONDAY. AT THAT TIME...LOW LEVEL FLOW WILL BECOME
MORE SOUTHERLY AND BRING A RETURN OF MOISTURE AND MORE FAVORABLE
CONVECTIVE PARAMETERS. RAIN CHANCES FOR SUNDAY WILL STILL BE ON
THE LOW SIDE AS THE BETTER DYNAMICS RESIDE TO OUR NW.
AS FOR THE NEAR TERM TEMPS...STILL LOOKING AT ABOVE NORMAL VALUES.
HOWEVER...OVERNIGHT LOWS THE NEXT FEW OVERNIGHTS WILL DROP INTO THE
MID TO UPPER 60S AS THE SOMEWHAT DRIER AIR PREVAILS. VERSUS THE
GUIDANCE...VERY LITTLE DEVIATION THIS ROUND.
IN THE EXT FCST...THE GFS SHOWS A NICELY STACKED STORM SYSTEM ON
APPROACH FOR TUESDAY. EURO SOLUTION IS ABOUT 24 HOURS LATER. SFC LOW
LOOKS AS THOUGH IT WILL TRACK ACROSS NORTHERN MIDDLE TN ON WED
AFTERNOON. AT THAT TIME...CAPE VALUES LOOK UNIMPRESSIVE AND THE
SYSTEM APPEARS TO BE MORE OF A RAINFALL EVENT. CAPES ARE HIGHER TO
OUR SOUTH WHERE THE BETTER MID LEVEL JET RESIDES. AT ANY
RATE...CANNOT RULE OUT AN INCH OR SO OF RAINFALL FOR TUESDAY THROUGH
WEDNESDAY.
FOLLOWING THE EXIT OF THE MID WEEK STORM SYSTEM. WEAK RIDGING WILL
ATTEMPT TO REESTABLISH ITSELF. HOWEVER...BOTH THE RESIDUAL AND
SOUTHERLY FLOW INDUCED MOISTURE WILL UNDERCUT ANY RIDGING THAT
DEVELOPS AND CONTINUE TO PROVIDE LOW CHANCES OF SHOWERS AND TSTMS
FOR THU AND FRI.
FOR THE EXT TEMPS...VALUES WILL CONTINUE TO RUN A FEW DEGREES ABOVE
NORMAL. A SLIGHT UNDERCUT ON MAX TEMPS WILL BE UTILIZED AS 850 MB
TEMPS ARE KEPT WITHIN THE 16C TO 18C RANGE AND A LITTLE MORE IN THE
WAY OF CLOUDINESS WILL EXIST.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
31
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
916 AM EDT SAT JUN 21 2014
.SYNOPSIS...
LOW PRESSURE OVER OHIO WILL MOVE SOUTHEAST ALONG A FRONT INTO
SOUTHEAST VIRGINIA BY THIS EVENING. HIGH PRESSURE WILL COVER THE
NORTHEAST AND MID ATLANTIC REGION TONIGHT AND SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 912 AM EDT SATURDAY...
MORNING SHOWERS OVER THE PIEDMONT ARE EXITING THE AREA WHILE A NEW
BATCH IS ENTERING THE WESTERN SLOPES OF RNK CWA. ADJUSTED POPS TO
REFLECT RADAR TREND THROUGH THE REST OF THE MORNING. MODELS ARE
STILL BULLISH FOR SHOWERS THIS AFTERNOON...ESPECIALLY ACROSS THE
PIEDMONT. 9AM RAP INSTABILITIES SHOWING 400-800 CAPE VALUES ACROSS
THE FOOTHILLS. IF THE SUN CAN PENETRATE THICK MORNING
CLOUDS...FORECAST LOOKS GOOD FOR HIGH POPS IN THE EAST THIS
AFTERNOON. LEFT THE MAJORITY OF THE AFTERNOON FORECAST AS IS..JUST
ADJUSTED TIMING THROUGH NOON.
AS OF 400 AM EDT SATURDAY...
VERY LITTLE CHANGE IN THE OVERALL WEATHER PATTERN IS EXPECTED TODAY
AND TONIGHT. A WAVY STATIONARY FRONT TRAILED FROM THE OHIO VALLEY
INTO NORTH CAROLINA. LOW LEVEL MOISTURE AND SURFACE DEW POINTS
HOLDING IN THE MID TO UPPER 60S WILL RESULT IN DECENT MIXED LAYER
CAPES WITH ANY HEATING TODAY. AMOUNT OF SUN THIS MORNING IS
CHALLENGING. WEAK CAPPING...AT LEAST NOT WARM ENOUGH AT MID LEVELS
THAT CAP CAN BE OVERCOME WITH HEATING...CONVERGENCE ALONG THE
BOUNDARY AND CAPES AROUND 1500 J/KG SUPPORT OTHER AFTERNOON AND
EVENING WITH SCATTERED SHOWERS AND THUNDERSTORMS. WILL ALIGN HIGHEST
PROBABILITY OF PRECIPITATION ALONG THE BOUNDARY...MAINLY FROM THE
BLUE RIDGE NORTH OF ROANOKE INTO MUCH OF THE PIEDMONT THIS
AFTERNOON...BUT NO AREA IS FREE FROM ANY RAIN CHANCE TODAY.
PRECIPITABLE WATER VALUES ARE FORECAST TO BE CLOSE TO 2.0 INCHES IN
THE FAR SOUTHEAST CORNER OF THE FORECAST AREA THIS AFTERNOON. WILL
MENTION HEAVY RAIN THREAT IN THE FORECAST AND HAZARDOUS WEATHER
OUTLOOK.
SURFACE LOW PRESSURE IN SOUTHEAST VIRGINIA BY THIS EVENING WILL
BRING LOW LEVEL WINDS AROUND TO THE NORTH AND NORTHEAST. THIS MAY
BRIEFLY BRING RELATIVELY MORE STABLE AIR INTO THE REGION OVERNIGHT.
THIS SHOULD LIMIT THE COVERAGE OF SHOWERS.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 305 AM EDT SATURDAY...
RELATIVELY LITTLE CHANGE IN AIRMASS ANTICIPATED DURING THE SHORT
TERM PERIOD WITH BAROCLINIC ZONE REMAINING TO THE NORTH OF THE
BLACKSBURG FORECAST AREA. DAILY TEMPERATURE CHANGES WILL LARGELY BE
INFLUENCED BY EXTENT OF CLOUD COVER AND IMPACT OF ANY PASSING
SHOWERS/THUNDERSTORMS.
ATMOSPHERE OVER THE MID APPALACHIAN AND MID ATLANTIC STATES WILL
REMAIN MAINLY UNCAPPED...BUT WITH MID LEVEL LAPSE RATES RATHER
ANEMIC. WITH LACK OF ANY SIGNIFICANT SHORT WAVE FORCING...THREAT OF
PRECIPITATION WILL BE DIURNALLY DRIVEN...AND NOT AS STRONG AS THE
PAST SEVERAL DAYS.
EXPECT TO SEE REDEVELOPMENT OF SHOWERS/THUNDERSTORMS BY LATE SUNDAY
MORNING/EARLY AFTERNOON ALONG/NEAR THE SPINE OF THE BLUE RIDGE AS
WEAK CONFLUENCE SETS UP DUE TO LIGHT NORTHEAST TO EAST WINDS EAST OF
THE MOUNTAINS...WITH MORE OF A WESTERLY COMPONENT FURTHER WEST.
COMBINATION OF LOW LEVEL CONFLUENCE AND DIFFERENTIAL HEATING SHOULD
BE SUFFICIENT TO SUPPORT AT LEAST WIDELY SCATTERED ACTIVITY...WHICH
WILL LIKELY DRIFT EAST OUT OVER THE FOOTHILLS BY MID-LATE AFTERNOON
BEFORE GRADUALLY DISSIPATING WITH LOSS OF DAYTIME HEATING ON SUNDAY
EVENING.
SLOWLY RISING HEIGHTS AS UPPER RIDGE BEGINS TO BUILD NORTH FROM OFF
THE SOUTHEAST COAST...WITH UPPER TROFFING DEVELOPING UPSTREAM OVER
THE MISSISSIPPI VALLEY...WILL SUPPORT SURFACE WINDS OVER THE
BLACKSBURG AREA TO GRADUALLY VEER INTO THE SOUTHEAST ON MONDAY...
AGAIN SUPPORTING THE BEST THREAT FOR WIDELY SCATTERED/SCATTERED
SHOWER/THUNDERSTORM REDEVELOPMENT DURING THE LATE MORNING/EARLY
AFTERNOON ALONG AND NEAR THE BLUE RIDGE. WITH MID LEVEL LAPSE
RATES REMAINING WEAK...THREAT FOR SEVERE WEATHER AGAIN APPEARS TO
BE MINIMAL AT THE PRESENT TIME.
MOS GUIDANCE SIMILAR THROUGH THE PERIOD AND GENERALLY ACCEPTED WITH
DAYTIME HIGHS MAINLY IN THE 80S...WITH 70S CONFINED TO THE HIGHER
ELEVATIONS...AND WITH OVERNIGHT LOWS GENERALLY BE IN THE 60S... WITH
SOME UPPER 50S POSSIBLE IN THE DEEPER MOUNTAIN VALLEYS.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 140 PM EDT FRIDAY...
THIS PERIOD OF THE FORECAST WILL STAY SIMILAR TO THE PREVIOUS
FORECAST. THE AIRMASS OVERALL STAYS ON THE WARM/HUMID SIDE WITH 5H
RIDGE OVER THE SOUTHEAST. ONE TROUGH AND ASSOCIATED FRONT WORKS
ACROSS THE MIDWEST INTO THE MID ATLANTIC BY WEDNESDAY. THIS WILL
NUDGE OUR CHANCE OF STORMS UP MIDWEEK. THE FRONT SITUATES ITSELF
MORE IN A WEST TO EAST ORIENTATION THU-FRI WHICH WILL KEEP THREAT
OF SHOWERS AND STORMS AROUND.
&&
.AVIATION /13Z SATURDAY THROUGH WEDNESDAY/...
AS OF 745 AM EDT SATURDAY...
WAVY WARM FRONT EXTENDED FROM THE MARYLAND PANHANDLE TO NORTHEAST
NORTH CAROLINA. ISOLATED LIGHT SHOWERS WERE OVER THE MOUNTAINS
ALONG WITH IFR TO MVFR CEILINGS. WATER VAPOR LOOP SHOWED A SHORT
WAVE OVER INDIANA AND OHIO. MODELS MOVE THIS FEATURE ACROSS THE
FORECAST AREA THIS MORNING. SCATTERED THUNDERSTORMS WILL DEVELOP
AGAIN THIS AFTERNOON...BUT THE BIGGEST QUESTION IS WHERE. AM
LEAVING THUNDERSTORMS OUT OF TAFS...EXCEPT FOR KDAN...FOR NOW
UNTIL IT IS CLEAR WHERE STORMS WILL DEVELOP TODAY
MVFR FOG WILL SLOWLY DISSIPATE. CONDITIONS MAY NOT IMPROVE TO VFR
UNTIL AFTER 16Z/NOON. CEILINGS AND VISIBILITY OUTSIDE OF SHOWERS
AND THUNDERSTORMS WILL THEN BE VFR FOR THE REST OF THE DAY.
EXTENDED AVIATION DISCUSSION...
CHANCE OF SHOWERS AND THUNDERSTORMS IS LESS ON SUNDAY. DEEPER
MOISTURE RETURNS NORTH...WITH BETTER COVERAGE OF AFTERNOON/EVENING
STORMS ON MONDAY AHEAD OF ANOTHER UPPER TROF AND FRONT TO THE
WEST. THIS BOUNDARY WILL GET CLOSER TUESDAY INTO WEDNESDAY WITH AT
LEAST DIURNAL DAILY ROUNDS OF SHOWERS AND STORMS LIKELY TUESDAY
INTO WEDNESDAY INCLUDING PERIODS OF MVFR/IFR.
AREAS OF IFR FOG REMAIN POSSIBLE EACH LATE NIGHT/EARLY MORNING...
PARTICULARLY IN AREAS THAT SEE RAIN THE PREVIOUS AFTERNOON. THE
MOST OPTIMAL FLIGHT CONDITIONS EACH DAY SHOULD BE IN THE MID TO
LATE MORNING AFTER FOG/LOW CLOUDS LIFT AND BURN OFF...AND BEFORE
AFTERNOON CONVECTION REDEVELOPS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/RCS
SHORT TERM...WERT
LONG TERM...WP
AVIATION...AMS/JH/RCS
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1138 AM MDT SAT JUN 21 2014
.UPDATE...
ISSUED AT 1028 AM MDT SAT JUN 21 2014
CONSIDERABLE AMOUNT OF MID/HIGH LEVEL CLOUD (ASSOCIATED WITH
EMBEDDED WEAK SHORT WAVES) STREAMING ACROSS THE REGION TODAY. AS
DEEP LAYERED MIXING OCCURS...EXPECT THE CLOUD LAYER TO "THIN" OUT
IN THE AFTERNOON. MORNING CLOUD COVER MAY HAVE A MINOR IMPACT ON
FORECASTED HIGH TEMPS BY 1-2 DEGREES...BUT RECOVERY BENEATH THE
JUNE SUN CAN BE VERY QUICK.
CONVECTIVE POTENTIAL BETWEEN THE RAP AND NAM12 IS SIGNIFICANT...WITH
THE WETTER NAM12 SUGGESTING SOME ACTIVITY HUGGING THE HIGHER
TERRAIN. THE HIGHER RESOLUTION NAMDNG25 IS NOT AS WET. CLOUD
COVER TYPICALLY TEMPERS THE CONVECTIVE POTENTIAL...COMBINED WITH
PERCIPITABLE WATER AT FOUR TENTHS OF AN INCH (PER 12Z GJT
SOUNDING) AND MOIST LAYER AT OR ABOVE 500 MB...NOT INCLINED TO
INCREASE THE CHANCE FOR STORMS THIS AFTERNOON. A LIGHTNING STRIKE
OR TWO MAY OCCUR OVER THE UINTA MOUNTAINS AND ALONG THE COLORADO
SPINE.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 343 AM MDT SAT JUN 21 2014
TODAY...A WEAK SHORTWAVE TROUGH WELL SEEN AT 700 MB AND 500
MB...AND SATELLITE IMAGES...WILL BRING MID AND HI LEVEL MOISTURE
TO THE AREA THIS MORNING AND AFTERNOON. EXPECT ISOLATED
THUNDERSTORMS OVER THE HIGHER PEAKS FROM EARLY AFTERNOON UNTIL
SUNSET. MAX TEMPS WILL CONTINUE MOVING UPWARD WITH MOST AREAS
REACHING HIGHS A FEW DEGREES ABOVE NORMAL.
TONIGHT AND SUNDAY...FAST...PROGRESSIVE...WESTERLY FLOW STAYS IN
PLACE TO CLOSE OUT THE WEEKEND ACROSS THE CONUS. THERE WILL BE A
SERIES OF WAVES TREKKING OUT OF THE EASTERN PACIFIC INTO THE
INTERMOUNTAIN WEST THROUGH THIS FLOW. DYNAMIC TROP PRESSURE FIELDS
INDICATE THESE WILL BE WEAKENING AS THEY MOVE EAST TOWARD OUR CWA SO
LARGE SCALE ASCENT LOOKS UNORGANIZED. THE MOISTURE COMING OUT OF THE
PACIFIC WITH THE WAVES IS NOT IMPRESSIVE EITHER AND SEEMS TO REMAIN
AOA 500 MB. THERE IS A HINT OF JET INTERACTION WITH THE APPROACHING
WAVE OVERNIGHT. CONFIDENCE NOT HIGH BUT THERE COULD BE ISOLATED
NOCTURNAL CONVECTION DEVELOP OVERNIGHT...POPS VERY LIMITED AS ACCAS
IS MORE LIKELY IN THE HIGHLY MIXED ATMOSPHERE. TEMPERATURES REMAIN
SOMEWHAT MILD WITH HIGH CLOUDS OVERNIGHT. H7 TEMPS AND GUIDANCE
SUGGEST A SLIGHT COOL DOWN FOR SUNDAY WITH WEAK CAA BEHIND THE WAVE
MOVING THROUGH SUNDAY. THIS MAY BE THE PERIOD WITH THE HIGHEST POPS
OF THE FORECAST...BUT MAINLY OVER THE EASTERN DIVIDE MOUNTAINS.
LOOKING AT SOUNDINGS AND DCAPE FORECASTS GUSTY WINDS WILL BE MORE
LIKELY THAN RAINFALL.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 343 AM MDT SAT JUN 21 2014
SUNDAY NIGHT INTO MONDAY...PV FIELDS SHOW YET ANOTHER WEAK WAVE
PASSING THROUGH THE ROCKIES SUNDAY NIGHT...BUT WITH LITTLE TO NO
SUPPORT. BEHIND THIS LAST WAVE THERE IS A HINT OF A BUILDING WESTERN
RIDGE. THE BULK OF THE MODEL SOLUTIONS ARE QUIET MONDAY AFTERNOON
OUTSIDE OF THE DIVIDE. HOWEVER THE NAM WANTS TO SWING ANOTHER BATCH
OF ENERGY THROUGH DURING PEAK HEATING. DO NOT WANT TO BITE ON THIS
JUST YET AS NAM SEEMS TO BE OVER EAGER TO PRODUCE CONVECTION.
CLEARING SKIES SUNDAY NIGHT SHOULD LOWER OVERNIGHT LOWS A FEW
DEGREES WHILE A STRONG DIURNAL REBOUND PUSHES HIGHS ON MONDAY BACK
ABOVE NORMAL.
MONDAY NIGHT THROUGH FRIDAY...MAINLY WEAK ZONAL FLOW SHOULD
CONTINUE OVER THE AREA THRU TUE NIGHT. ON WED BOTH THE GFS AND EC
SHOW A TROUGH DIGGING INTO THE GREAT BASIN AND STRENGTHENING SW
WINDS ALOFT AHEAD OF THE TROUGH AND OVER THE FORECAST AREA. THE EC
IS STRONGER WITH THIS SYSTEM AND CARRIES A HIGH AMPLITUDE TROUGH
AND RELATIVELY STRONG SURFACE COLD FRONT THROUGH THE FORECAST AREA
THU NIGHT AND FRI. THE GFS WEAKENS THE TROUGH AS IT MOVES EAST AND
LIFT A BIT TO THE NE OVER THE NORTHERN ROCKIES. THE SURFACE FRONT
IN THE GFS IS MUCH WEAKER AS WELL...SO THE CHANGE IN THE FORECAST
AT THE END OF THE PERIOD REMAINS UNCERTAIN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1138 AM MDT SAT JUN 21 2014
LOCAL LIGHT TO MODERATE CHOP AS MID/HIGH CLOUD CLOUD LAYER HAS
POCKETS OF VIRGA. THREAT OF -TSRA THROUGH 02Z WILL BE CONFINED TO
THE EASTERN UINTA MOUNTAINS AND TOWARD THE COLORADO HIGH COUNTRY.
VFR PREVAILS THROUGH THE FORECAST PERIOD.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
UPDATE...PF
SHORT TERM...CC/15
LONG TERM...15/CC
AVIATION...PF
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1028 AM MDT SAT JUN 21 2014
.UPDATE...
ISSUED AT 1028 AM MDT SAT JUN 21 2014
CONSIDERABLE AMOUNT OF MID/HIGH LEVEL CLOUD (ASSOCIATED WITH
EMBEDDED WEAK SHORT WAVES) STREAMING ACROSS THE REGION TODAY. AS
DEEP LAYERED MIXING OCCURS...EXPECT THE CLOUD LAYER TO "THIN" OUT
IN THE AFTERNOON. MORNING CLOUD COVER MAY HAVE A MINOR IMPACT ON
FORECASTED HIGH TEMPS BY 1-2 DEGREES...BUT RECOVERY BENEATH THE
JUNE SUN CAN BE VERY QUICK.
CONVECTIVE POTENTIAL BETWEEN THE RAP AND NAM12 IS SIGNIFICANT...WITH
THE WETTER NAM12 SUGGESTING SOME ACTIVITY HUGGING THE HIGHER
TERRAIN. THE HIGHER RESOLUTION NAMDNG25 IS NOT AS WET. CLOUD
COVER TYPICALLY TEMPERS THE CONVECTIVE POTENTIAL...COMBINED WITH
PERCIPITABLE WATER AT FOUR TENTHS OF AN INCH (PER 12Z GJT
SOUNDING) AND MOIST LAYER AT OR ABOVE 500 MB...NOT INCLINED TO
INCREASE THE CHANCE FOR STORMS THIS AFTERNOON. A LIGHTNING STRIKE
OR TWO MAY OCCUR OVER THE UINTA MOUNTAINS AND ALONG THE COLORADO
SPINE.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 343 AM MDT SAT JUN 21 2014
TODAY...A WEAK SHORTWAVE TROUGH WELL SEEN AT 700 MB AND 500
MB...AND SATELLITE IMAGES...WILL BRING MID AND HI LEVEL MOISTURE
TO THE AREA THIS MORNING AND AFTERNOON. EXPECT ISOLATED
THUNDERSTORMS OVER THE HIGHER PEAKS FROM EARLY AFTERNOON UNTIL
SUNSET. MAX TEMPS WILL CONTINUE MOVING UPWARD WITH MOST AREAS
REACHING HIGHS A FEW DEGREES ABOVE NORMAL.
TONIGHT AND SUNDAY...FAST...PROGRESSIVE...WESTERLY FLOW STAYS IN
PLACE TO CLOSE OUT THE WEEKEND ACROSS THE CONUS. THERE WILL BE A
SERIES OF WAVES TREKKING OUT OF THE EASTERN PACIFIC INTO THE
INTERMOUNTAIN WEST THROUGH THIS FLOW. DYNAMIC TROP PRESSURE FIELDS
INDICATE THESE WILL BE WEAKENING AS THEY MOVE EAST TOWARD OUR CWA SO
LARGE SCALE ASCENT LOOKS UNORGANIZED. THE MOISTURE COMING OUT OF THE
PACIFIC WITH THE WAVES IS NOT IMPRESSIVE EITHER AND SEEMS TO REMAIN
AOA 500 MB. THERE IS A HINT OF JET INTERACTION WITH THE APPROACHING
WAVE OVERNIGHT. CONFIDENCE NOT HIGH BUT THERE COULD BE ISOLATED
NOCTURNAL CONVECTION DEVELOP OVERNIGHT...POPS VERY LIMITED AS ACCAS
IS MORE LIKELY IN THE HIGHLY MIXED ATMOSPHERE. TEMPERATURES REMAIN
SOMEWHAT MILD WITH HIGH CLOUDS OVERNIGHT. H7 TEMPS AND GUIDANCE
SUGGEST A SLIGHT COOL DOWN FOR SUNDAY WITH WEAK CAA BEHIND THE WAVE
MOVING THROUGH SUNDAY. THIS MAY BE THE PERIOD WITH THE HIGHEST POPS
OF THE FORECAST...BUT MAINLY OVER THE EASTERN DIVIDE MOUNTAINS.
LOOKING AT SOUNDINGS AND DCAPE FORECASTS GUSTY WINDS WILL BE MORE
LIKELY THAN RAINFALL.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 343 AM MDT SAT JUN 21 2014
SUNDAY NIGHT INTO MONDAY...PV FIELDS SHOW YET ANOTHER WEAK WAVE
PASSING THROUGH THE ROCKIES SUNDAY NIGHT...BUT WITH LITTLE TO NO
SUPPORT. BEHIND THIS LAST WAVE THERE IS A HINT OF A BUILDING WESTERN
RIDGE. THE BULK OF THE MODEL SOLUTIONS ARE QUIET MONDAY AFTERNOON
OUTSIDE OF THE DIVIDE. HOWEVER THE NAM WANTS TO SWING ANOTHER BATCH
OF ENERGY THROUGH DURING PEAK HEATING. DO NOT WANT TO BITE ON THIS
JUST YET AS NAM SEEMS TO BE OVER EAGER TO PRODUCE CONVECTION.
CLEARING SKIES SUNDAY NIGHT SHOULD LOWER OVERNIGHT LOWS A FEW
DEGREES WHILE A STRONG DIURNAL REBOUND PUSHES HIGHS ON MONDAY BACK
ABOVE NORMAL.
MONDAY NIGHT THROUGH FRIDAY...MAINLY WEAK ZONAL FLOW SHOULD
CONTINUE OVER THE AREA THRU TUE NIGHT. ON WED BOTH THE GFS AND EC
SHOW A TROUGH DIGGING INTO THE GREAT BASIN AND STRENGTHENING SW
WINDS ALOFT AHEAD OF THE TROUGH AND OVER THE FORECAST AREA. THE EC
IS STRONGER WITH THIS SYSTEM AND CARRIES A HIGH AMPLITUDE TROUGH
AND RELATIVELY STRONG SURFACE COLD FRONT THROUGH THE FORECAST AREA
THU NIGHT AND FRI. THE GFS WEAKENS THE TROUGH AS IT MOVES EAST AND
LIFT A BIT TO THE NE OVER THE NORTHERN ROCKIES. THE SURFACE FRONT
IN THE GFS IS MUCH WEAKER AS WELL...SO THE CHANGE IN THE FORECAST
AT THE END OF THE PERIOD REMAINS UNCERTAIN.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 343 AM MDT SAT JUN 21 2014
VFR CONDITIONS WILL PREVAIL ACROSS THE AREA AND AT ALL AIRPORTS
AND TAF SITES THROUGH TONIGHT...WITH THE EXCEPTION OF ISOLATED
THUNDERSTORMS BETWEEN ABOUT 20Z AND 03Z OVER THE RIDGES. THESE
WILL BE RELATIVELY SHORT-LIVED WITH GUSTY WINDS BEING THE MAIN
IMPACTOR ON AVIATION.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
UPDATE...PF
SHORT TERM...CC/15
LONG TERM...15/CC
AVIATION...CC
REMAINING FORECAST DISCUSSION WILL BE ISSUED SHORTLY...
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* VCTS TRENDING TO ISOLATED-SCATTERED TSRA BETWEEN 20-23Z.
* LGT WINDS...GENERALLY SE ARND 8-10KT. THUNDERSTORMS MAY BRIEFLY
BECOME VRB DIR/SPEEDS IN AND ARND THUNDERSTORMS.
* FOG REDEVELOPS AFT 6Z TONIGHT...VSBY COULD EASILY BE REDUCED TO
NEAR IFR CONDS.
BEACHLER
//DISCUSSION...UPDATED 18Z...
VISIBLE IMAGERY THIS AFTN SHOWS MOST CLOUD COVER CONFINED TO NORTH
OF CENTRAL IL OVER THE TAF SITES...WITH SOME ENHANCEMENT BEGINNING
TO DEVELOP. RADAR RETURNS HAVE BEEN SHOWING ISO TSRA DEVELOPING
AND HAVE BEEN PRODUCING SOME LIGHTNING WITH EXPECTED CONTINUE
GROWTH IN SIZE AND INTENSITY OF THE THUNDERSTORMS. WINDS ARE
GENERALLY FROM THE SOUTHEAST ACROSS FAR NORTHEAST IL/NORTHWEST
IN...MEANWHILE JUST WEST OF THOSE SITES WINDS TURN TO
SOUTHWESTERLY OR SOUTHERLY. WITH THE LACK OF A GRADIENT...SPEEDS
HAVE HELD AROUND 8KT OR LESS WITH AN OCCASIONAL GUST TO 16KT. IF
TSRA CAN BECOME MORE ORGANIZED...THE POTENTIAL FOR WINDS TO BECOME
STRONGER IN AND ARND TSRA IS PROBABLE. THE BEST TIMING FOR
INCREASED COVERAGE IN TSRA WILL BE 20-23Z FOR NORTHERN IL...THEN
LINGERING TO JUST AFT 00Z ACROSS NORTHWEST IN. LATER THIS EVENING
THE POTENTIAL OF AN ISO TSRA CONTINUES...HOWEVER THE CONFIDENCE IN
COVERAGE AND PRECISE TIMING DECREASES. SO HAVE OPTED TO HOLD OFF
ON ANY MENTION OF ADDTL TSRA THIS EVE. OVERNIGHT WINDS BECOME LGT
AND VRB AGAIN...WITH THE POSSIBILITY OF FOG REDEVELOPING. AT THIS
TIME CONFIDENCE IS THAT THE DENSE FOG SHOULD BE CONFINED TO LAKE
MICHIGAN. ALTHOUGH THAT BEING SAID MOST TAF SITES WILL STILL SEE
VSBYS DROP TO ARND 2-3SM AND POSSIBLY RFD/DPA COULD DIP TO ARND
1SM OVERNIGHT.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN TSRA DEVELOPING...MEDIUM CONFIDENCE IN
PRECISE TIMING/COVERAGE OF TSRA BETWEEN 19-23Z.
* MEDIUM/HIGH CONFIDENCE IN WIND DIR/SPEED.
* MEDIUM/HIGH CONFIDENCE IN FOG REDEVELOPING...LOW CONFIDENCE IN
PRECISE TIMING.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...CHANCE TSRA.
MONDAY...TSRA LIKELY.
TUESDAY THROUGH THURSDAY...PERIOD CHANCES FOR TSRA/SHRA.
THURSDAY NIGHT AND FRIDAY...VFR. WX NIL.
KREIN
&&
.MARINE...
234 PM CDT
GENERALLY LIGHT WIND REGIME OUTSIDE OF THUNDERSTORM INDUCED WINDS TO
CONTINUE THOUGH MONDAY NIGHT WHEN A COLD FRONT WILL SWEEP ACROSS THE
LAKE BRINGING DRYER CONDITIONS AND NORTHERLY FLOW BY TUESDAY. UNTIL
THEN... EXPECT AREAS OF DENSE FOG TO PERSIST OVER THE LAKE WITH
WINDS GENERALLY REMAINING AT OR BELOW 20 KTS AND WAVES AT OR BELOW 3
FEET. WINDS AND WAVES WILL BE HIGHER NEAR THUNDERSTORMS.
A RIDGE OF HIGH PRESSURE FROM JAMES BAY TO THE CENTRAL GREAT LAKES
WILL REMAIN NEARLY STATIONARY TONIGHT AND THEN GRADUALLY DRIFT EAST
SUNDAY. MEANWHILE WEAK LOW PRESSURE OVER WISCONSIN WILL SLIDE
SOUTHEAST ALONG A NEARLY STATIONARY FRONTAL BOUNDARY ACROSS NORTH
CENTRAL ILLINOIS TO SOUTHEAST ILLINOIS OVERNIGHT AND DISSIPATE. WEAK
LOW PRESSURE OVER THE CENTRAL PLAINS WILL BECOME BETTER ORGANIZED AS
IT DOES AND MOVE EAST. THIS LOW WILL REACH CENTRAL IOWA BY DAYBREAK
MONDAY AND MOVE TO THE EASTERN UPPER PENINSULA OF MICHIGAN BY
OVERNIGHT MONDAY INTO TUESDAY.
A WEAK COLD FRONT ASSOCIATED WITH THIS LOW WILL THEN SWEEP ACROSS THE
LAKE LATE MONDAY NIGHT INTO TUESDAY...TURNING WINDS FROM SOUTHERLY
TO NORTHERLY. BROAD HIGH PRESSURE WILL THEN BUILD INTO THE UPPER
GREAT LAKES WEDNESDAY LASTING INTO THURSDAY.
ED F
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...DENSE FOG ADVISORY...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-
LMZ565-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-
LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-LMZ870-
LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 10 AM SUNDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
100 PM CDT SAT JUN 21 2014
.MESOSCALE DISCUSSION...
UPDATED...1029 AM CDT
CONVECTIVE POTENTIAL FOR EARLY TO MID AFTERNOON TODAY WITH A
THREAT REMAINING FOR STRONG TO SEVERE WEATHER...PRIMARILY A HIGH
WIND THREAT...ACROSS NORTH CENTRAL ILLINOIS AND POSSIBLY NORTHWEST
INDIANA.
CURRENT RADAR IMAGERY DEPICTING ISOLATED SHOWER ACTIVITY ACROSS
NORTH CENTRAL AND NORTHEAST ILLINOIS SLIDING EAST OUT AHEAD OF
WEAKENING WAA WING STRETCHING SOUTH THROUGH THE AREA. DONT
ANTICIPATE ANY FURTHER DEVELOPMENT WITH THESE SHOWERS THIS MORNING
WITH THE CURRENT ISOLATED COVERAGE REMAINING THE SAME NOR DO I
EXPECT MUCH IN TERMS OF ANY THUNDER OUTSIDE OF A FEW RUMBLES OF
THUNDER...AS THIS PRECIP IS BEING WEAKLY FORCED AND IN THE
PRESENCE OF A MORE STABLE ENVIRONMENT. OUTSIDE OF THIS
DEVELOPMENT...EXPECT THE REMAINDER OF THE MORNING TO REMAIN DRY
WHILE LOW STRATUS FURTHER DIMINISHES THROUGH MID DAY WITH MORE
AREAS OBSERVING PARTLY CLOUDY TO PARTLY SUNNY CONDITIONS.
SHIFT FOCUS TO MAIN THUNDERSTORM THREAT FOR THIS AFTERNOON...AND
POSSIBLY INTO THE EARLY EVENING...FOR THE ENTIRE AREA OF NORTH
CENTRAL/NORTHEAST ILLINOIS AND NORTHWEST INDIANA. THE THUNDERSTORM
POTENTIAL WILL BE TIED TO APPROACHING MCV AND LINGERING FRONTAL
BOUNDARY SITUATED FROM NORTHWEST ILLINOIS BACK SOUTHEAST THROUGH
EAST CENTRAL ILLINOIS...AND INTO NORTHWEST INDIANA. AS THIS
VIGOROUS SYSTEM PUSHES EAST INTO NORTHERN ILLINOIS AND SOUTHERN
WISCONSIN BY MID DAY...IT WILL BE ENCOUNTERING AN INCREASINGLY
UNSTABLE ENVIRONMENT WHICH IS ALREADY OCCURRING OVER WESTERN
ILLINOIS WITH LATEST RAP ANALYSIS SHOWING STEADILY STEEPENING LOW
LEVEL LAPSE RATES. LIMITING FACTORS SUCH HIGH CIN IN PLACE WILL
ERODE THROUGH MID DAY WHILE CURRENT MODERATE INSTABILITY AXIS FROM
NORTHWEST ILLINOIS SOUTH TO WEST CENTRAL ILLINOIS BEGINS SPREADING
EASTWARD. SHORT TERM GUIDANCE IN FAIR AGREEMENT WITH THE TIMING OF
THIS OCCURRENCE AROUND THE 19Z TO 20Z TIME FRAME...AND WILL BE
OCCURRING AS LARGE SCALE ASCENT WITH APPROACHING SYSTEM SPREADS
EAST. MOST CURRENT GUIDANCE THIS MORNING IN AGREEMENT WITH
DEVELOPING PRECIP ACROSS THE CWA THIS AFTERNOON AND ALTHOUGH I DO
AGREE WITH THE IDEA/SOLUTION...I WONDER IF THE COVERAGE WILL BE AS
EXTENSIVE AS IS BEING ADVERTISED. THIS CONCERN IS TIED TO LOW
LEVEL CONVERGENCE POTENTIAL WITH WHICH CURRENT GUIDANCE IS
APPEARING TO BE OVERDOING AT THIS TIME. IF THIS OVERESTIMATE
CONTINUES...COVERAGE MAY NOT BE AS EXTENSIVE.
NONETHELESS...DESPITE THIS LIMITING FACTOR FEEL THAT LARGE SCALE
SUPPORT IN A MODERATELY TO STRONGLY UNSTABLE ENVIRONMENT SHOULD BE
ENOUGH TO AT LEAST DEVELOP SCATTERED DEVELOPMENT THIS AFTERNOON.
CURRENT ASSESSMENT WOULD PLACE HIGHER THREAT FOR STRONG TO SEVERE
WEATHER ACROSS THE WEST AND SOUTHWEST CWA WHERE BETTER INSTABILITY
WILL RESIDE...BUT AS THE STABLE ENVIRONMENT ACROSS NORTHEAST
ILLINOIS AND NORTHWEST INDIANA BECOMES MORE UNSTABLE LATER THIS
AFTERNOON FEEL THAT ALL AREAS COULD POTENTIALLY HAVE THE SAME
THREAT. SO DONT WANT TO REALLY POINT OUT ONE AREA OVER THE OTHER
AT THIS TIME...BUT WILL CONTINUE TO MONITOR THIS POTENTIAL WITH AN
UPDATED AFD WITH LATEST THINKING LIKELY BY MID DAY.
AREAS ALONG AND WEST OF INTERSTATE 39 COULD OBSERVE SCATTERED
STRONG TO SEVERE THUNDERSTORM DEVELOPMENT BY 19-20Z...SPREADING
EAST THROUGH REMAINING AREAS IN NORTH CENTRAL ILLINOIS AND THEN
NORTHEAST ILLINOIS IN THE 20-22Z TIME FRAME. CONFIDENCE IS LOWER
WITH REGARD TO STRONG/SEVERE THREAT IN NORTHWEST INDIANA...BUT IF
THIS WERE TO SPREAD EAST INTO THESE AREAS IT WOULD BE IN THE
22-23Z TIME WINDOW. THE MAIN SEVERE THREAT TODAY WILL BE DAMAGING
WIND GUSTS...BUT HAIL COULD POSSIBLY BECOME AN ISSUE ESPECIALLY IN
ANY OF THE MORE DEVELOPED THUNDERSTORMS.
RODRIGUEZ
&&
.DISCUSSION...
339 AM CDT
THE BASIC PATTERN THAT HAS NOW BEEN IN PLACE FOR NEARLY A WEEK WILL
CONTINUE THROUGH MONDAY...WHICH MEANS NUMEROUS FORECAST CHALLENGES
ON THIS SUMMER SOLSTICE. MORNING FOG AND STRATUS IS FIRST IN THE
TIMELINE FOLLOWED BY ITS IMPACT ON TEMPERATURES AND
DESTABILIZATION FOR THUNDERSTORM COVERAGE THIS AFTERNOON.
QUANTIFYING ANY SEVERE POTENTIAL ALSO NEEDED TO BE ASSESSED.
FINALLY...CONTINUED THUNDERSTORM CHANCES...ESPECIALLY THROUGH
MONDAY NIGHT...ROUNDED OUT THE FORECAST THIS MORNING.
FOG AND TEMPERATURES...
DENSE FOG THAT HAD EXPANDED INLAND LAST EVENING BEHIND THE
IMPRESSIVE LAKE BREEZE,,,WHICH AS OF 330 AM HAS FINALLY STALLED
NEAR INTERSTATE 74...CONTINUES OVER LAKE ADJACENT COUNTIES. WEB
CAMS AND REPORTS INDICATE THIS IS MOST DENSE NEAR THE LAKE SHORE
AND WILL CONTINUE THE DENSE FOG ADVISORY THROUGH 9 AM...WITH
POTENTIALLY SOME SHORELINE LOCALES DOWN TO A FEW HUNDRED FEET
VISIBILITY. VAD PROFILES INDICATE THE NORTHEAST FLOW IS ABOUT
2000-3000FT THICK AND AN AMDAR SOUNDING FROM LAST EVE INDICATES
SATURATION IS ONLY ABOUT HALF OF THAT. WITH THIS BEING THE LONGEST
DAYLIGHT OF THE YEAR ONE WOULD THINK WE COULD MIX THROUGH THIS
QUICKLY...ESPECIALLY WITH THE SOURCE FLOW OFF THE LAKE HAVING
CONSIDERABLY WEAKENED. THE ONE CONCERN WITH THAT IS CONVECTIVE
DEBRIS CLOUDS ARE SPREADING OVER THIS WHICH WILL FURTHER INSULATE
THIS MORNING. SO THAT WILL NEED TO BE WATCHED. HAVE ADJUSTED
FORECAST HOURLY TEMPERATURES TO SLOW THE RATE OF WARMING
CONSIDERABLY AND THAT LED TO COOLER HIGH TEMPERATURES. WHILE
TEMPERATURES WILL COULD DEPEND ON CONVECTIVE INITIATION TIME AND
COVERAGE /SEE BELOW/...FEEL THAT UNDERCUTTING GUIDANCE AND CLIMO
WAS THE WAY TO GO...OWING TO THE MUCH COOLER-THAN-NORMAL WATER
TEMPERATURES OF LAKE MICHIGAN WHICH FED THIS AREA OF FOG/STRATUS.
THUNDERSTORM POTENTIAL...
MULTIPLE LOW AMPLITUDE UPPER DISTURBANCES WILL TRANSLATE EASTWARD
TODAY ACROSS A BELT OF ZONAL FLOW EXTENDING FROM THE CENTRAL PLAINS
OVER THE FORECAST AREA. THIS IS ON THE NORTHERN END OF CONTINUED
HIGH PRECIPITABLE WATER AND UNSTABLE AIR. ONGOING CONVECTION ACROSS
WESTERN AND CENTRAL IA AS OF 330 AM HAS WEAKENED CONSIDERABLY WITH
ONLY MARGINAL MOISTURE TRANSPORT FEEDING IT. DOES LOOK LIKE THE
SHORT WAVE MAY BE CONVECTIVELY ENHANCED WITH A POSSIBLE MCV AND
TIMING THAT FEATURE SEEMS KEY FOR OUR MAIN STORM CHANCES TODAY.
THE SUITE OF GUIDANCE VARIES CONSIDERABLY AND GIVEN THAT AND
SIMPLY THE TRICKY SYNOPTIC POSITION WE ARE IN...AS WELL AS THE
MESOSCALE FACTOR OF THE CURRENT FOG/STRATUS...CONFIDENCE IS LOW
ON THUNDERSTORM COVERAGE AND TIMING TODAY.
INCREASE POPS GRADUALLY THIS MORNING WITH SOME SCATTERED ELEVATED
STORMS POSSIBLE IN NORTH CENTRAL IL...AND THEN MORE SO EARLY THIS
AFTERNOON AS MID-LEVEL FEATURE PASSES OVER THE FORECAST AREA.
CONVECTIVE TEMPERATURES LOOK TO BE AROUND 80 DEGREES AND NOT
CERTAIN IF PARTS OF NORTHEAST IL WILL REACH THAT...SO KEEP HIGHER
POPS MAINLY ALONG AND SOUTH OF THE MORE STABLE LOW-LEVEL AIR IN
PLACE /JUST SOUTH OF CHICAGO/. THIS ALSO IS WHERE LOW-LEVEL
CONVERGENCE EXISTS...ALBEIT WITH AWFULLY WEAK FLOW. SO AM NOT
ENVISIONING GREAT COVERAGE OF AFTERNOON STORMS BUT ENOUGH TO
SUPPORT 40 TO 50 PERCENT POPS AND HAVE GONE WITH SCATTERED
WORDING. CONVECTIVE CELLS POSSIBLY BECOMING MORE MULTICELL WITH
SMALL-SCALE COLD POOLS ARE THE PROBABLE EVOLUTION. MID-LEVEL LAPSE
RATES ARE POOR AND THE THERMODYNAMIC ENVIRONMENT LOOKS ALREADY
HINDERED BY THE INVERSION IN PLACE...SO NOT EXPECTING MUCH FOR
HAIL...BUT SOME OF THE MORE ORGANIZED STORMS COULD HAVE AN
ISOLATED WIND THREAT DUE TO PRECIP LOADING AND SOME HIGHER
DOWNDRAFT CAPE INDICATED BY A FEW HIGH-RES MODELS. THIS WOULD
SEEM A LITTLE MORE FAVORED SOUTH OF A ROCKFORD TO RENSSELAER LINE.
TONIGHT...
GRADUAL WARM AIR ADVECTION AND ANOTHER ONE OR TWO MINOR IMPULSES MAY
CONTINUE SEPARATE SCATTERED STORMS FROM THE EARLIER ACTIVITY AFTER
DARK...NAMELY OVER THE WESTERN AND SOUTHERN FORECAST AREA. IN
ADDITION...LIGHT WIND FLOW ELSEWHERE MAY ALLOW STRATUS AND/OR FOG TO
DEVELOP. THIS AGAIN WOULD BE ESPECIALLY FAVORED NEAR THE LAKE SHORE.
HAVE ADDED FOG MENTION ONCE AGAIN IN CHICAGO BEGINNING LATER THIS
EVE.
SUNDAY AND MONDAY...
WARM AIR ADVECTION IS FORECAST TO INCREASE ON SUNDAY WITH THE CHANCE
FOR SCATTERED STORMS. MODEL GUIDANCE IS IN GOOD AGREEMENT WITH
NOTHING OVERLY ORGANIZED...SO HAVE KEPT POPS NEAR WHERE THEY
WERE. TEMPERATURES AGAIN WILL BE TRICKY...REMAINING MUCH COOLER
NEAR THE LAKE AND POTENTIALLY HAVING TO FIGHT THROUGH MORNING
STRATUS. HEIGHT FALLS ARE EXPECTED TO SPREAD INTO THE FORECAST
AREA ON MONDAY AND THAT LOOKS TO PRESENT THE BEST CHANCE FOR
STORMS INCLUDING INTO MONDAY NIGHT AS THE FRONT APPROACHES AND
MOVES THROUGH. PRECIPITABLE WATER IS ANTICIPATED TO CLIMB BACK
TO NEAR 1.75 INCHES WITH STRONG DEEP LAYER MOISTURE CONVERGENCE.
WHILE THE DEEP LAYER SHEAR IS NOT PARTICULARLY STRONG OWING TO THE
MARGINAL MID-LEVEL FLOW...ENOUGH INSTABILITY AND FOCUS IS PRESENT
WITH THE SYNOPTIC PATTERN TO WARRANT A HIGHER LIKELIHOOD FOR RAIN.
THE MORE SUN AND GREATER INSTABILITY ON MONDAY THEN THE LIKELY
BETTER CHANCES FOR SOME SEVERE POSSIBILITY.
TUESDAY AND BEYOND...
LONG RANGE GUIDANCE IS IN DECENT AGREEMENT WITH RAIN CHANCES
DIMINISHING THROUGH TUESDAY WITH THE AIR MASS BEING SOMEWHAT
SCOURED OUT SEEING DEW POINTS FORECAST DOWN INTO THE LOWER 60S. THE
UPPER AND MID-LEVEL PATTERN WILL KEEP US SOMEWHAT
UNSETTLED...THOUGH DEEP MOISTURE AND INSTABILITY WILL BE LESS.
HAVE A LOT OF SMALL POPS BUT THE OVERALL PATTERN TUE-THU DOES NOT
LOOK CONDUCIVE FOR HIGH IMPACT WEATHER. ONSHORE FLOW ON A FEW
MIDWEEK DAYS LOOKS TO KEEP TEMPERATURES ONCE AGAIN QUITE A BIT
COOLER NEAR THE LAKE.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* VCTS TRENDING TO ISOLATED-SCATTERED TSRA BETWEEN 20-23Z.
* LGT WINDS...GENERALLY SE ARND 8-10KT. THUNDERSTORMS MAY BRIEFLY
BECOME VRB DIR/SPEEDS IN AND ARND THUNDERSTORMS.
* FOG REDEVELOPS AFT 6Z TONIGHT...VSBY COULD EASILY BE REDUCED TO
NEAR IFR CONDS.
BEACHLER
//DISCUSSION...UPDATED 18Z...
VISIBLE IMAGERY THIS AFTN SHOWS MOST CLOUD COVER CONFINED TO NORTH
OF CENTRAL IL OVER THE TAF SITES...WITH SOME ENHANCEMENT BEGINNING
TO DEVELOP. RADAR RETURNS HAVE BEEN SHOWING ISO TSRA DEVELOPING
AND HAVE BEEN PRODUCING SOME LIGHTNING WITH EXPECTED CONTINUE
GROWTH IN SIZE AND INTENSITY OF THE THUNDERSTORMS. WINDS ARE
GENERALLY FROM THE SOUTHEAST ACROSS FAR NORTHEAST IL/NORTHWEST
IN...MEANWHILE JUST WEST OF THOSE SITES WINDS TURN TO
SOUTHWESTERLY OR SOUTHERLY. WITH THE LACK OF A GRADIENT...SPEEDS
HAVE HELD AROUND 8KT OR LESS WITH AN OCCASIONAL GUST TO 16KT. IF
TSRA CAN BECOME MORE ORGANIZED...THE POTENTIAL FOR WINDS TO BECOME
STRONGER IN AND ARND TSRA IS PROBABLE. THE BEST TIMING FOR
INCREASED COVERAGE IN TSRA WILL BE 20-23Z FOR NORTHERN IL...THEN
LINGERING TO JUST AFT 00Z ACROSS NORTHWEST IN. LATER THIS EVENING
THE POTENTIAL OF AN ISO TSRA CONTINUES...HOWEVER THE CONFIDENCE IN
COVERAGE AND PRECISE TIMING DECREASES. SO HAVE OPTED TO HOLD OFF
ON ANY MENTION OF ADDTL TSRA THIS EVE. OVERNIGHT WINDS BECOME LGT
AND VRB AGAIN...WITH THE POSSIBILITY OF FOG REDEVELOPING. AT THIS
TIME CONFIDENCE IS THAT THE DENSE FOG SHOULD BE CONFINED TO LAKE
MICHIGAN. ALTHOUGH THAT BEING SAID MOST TAF SITES WILL STILL SEE
VSBYS DROP TO ARND 2-3SM AND POSSIBLY RFD/DPA COULD DIP TO ARND
1SM OVERNIGHT.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN TSRA DEVELOPING...MEDIUM CONFIDENCE IN
PRECISE TIMING/COVERAGE OF TSRA BETWEEN 19-23Z.
* MEDIUM/HIGH CONFIDENCE IN WIND DIR/SPEED.
* MEDIUM/HIGH CONFIDENCE IN FOG REDEVELOPING...LOW CONFIDENCE IN
PRECISE TIMING.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...CHANCE TSRA.
MONDAY...TSRA LIKELY.
TUESDAY THROUGH THURSDAY...PERIOD CHANCES FOR TSRA/SHRA.
THURSDAY NIGHT AND FRIDAY...VFR. WX NIL.
KREIN
&&
.MARINE...
245 AM CDT
HIGH PRESSURE CENTERED WILL SIT OVER JAMES BAY THROUGH SATURDAY
NIGHT WITH WEAK RIDGING EXTENDING SOUTH ACROSS LAKE MICHIGAN TO
THE LOWER MISSISSIPPI VALLEY. A WEAK STATIONARY FRONT IS DRAPED
FROM NORTHERN MINNESOTA...JUST SOUTH OF THE LAKE TO THE OHIO
VALLEY. WITH WARM...MOIST AIR SPREADING OVER THE COLD LAKE WATER
AND SHIP OBS AND COASTAL SITES AND WEB CAMS INDICATING DENSE
FOG...A DENSE FOG ADVISORY HAS BEEN ISSUED FOR ALL OF THE OPEN
WATERS AND THE ILLINOIS AND INDIANA NEARSHORE WATERS. HAVE
EXTENDED THE DENSE FOG ADVISORY THROUGH SUNDAY MORNING AS THERE
WILL BE LITTLE CHANGE TO THE AIRMASS OVER THE LAKE. THE EXCEPTION
MAY BE THE FAR NORTHERN PORTION OF THE LAKE...WHERE WINDS SHOULD
TREND A LITTLE MORE EASTERLY THAN SOUTHERLY AND ADVECT SOME DRIER
AIR OVER THE LAKE...LIMITING THE DENSE FOG POTENTIAL. A COMPLEX
AREA OF LOW PRESSURE OVER THE CENTRAL PLAINS WITH MULTIPLE LOW
PRESSURE CENTERS...WILL GRADUALLY MOVE EAST ACROSS THE PLAINS AND
TO THE WESTERN GREAT LAKES REGION BY EARLY MONDAY. A WEAK COLD
FRONT SHOULD PUSH ACROSS THE LAKE MONDAY OR MONDAY NIGHT...TURNING
WINDS FROM GENERALLY SOUTHERLY TO MORE NORTHERLY. AS A LARGE AREA
OF HIGH PRESSURE BUILDS OUT OF CANADA TO THE UPPER GREAT LAKES
TUESDAY NIGHT AND WEDNESDAY...COOLER...DRIER AIR WILL OVERSPREAD
THE LAKE. THE COMBINATION OF THE FRONTAL PASSAGE AND THE BUILDING
HIGH PRESSURE SHOULD BRING AN END TO THE FOG POTENTIAL.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...DENSE FOG ADVISORY...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-
LMZ565-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-
LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-LMZ870-
LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 10 AM SUNDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
300 PM EDT SAT JUN 21 2014
.UPDATE...
THE LONG TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 322 AM EDT SAT JUN 21 2014
SLIGHTLY DRIER AIR WILL BE IN PLACE FOR THE BEGINNING OF TODAY.
HOWEVER...WESTERN PORTIONS OF CENTRAL INDIANA COULD SEE SOME
SCATTERED SHOWERS AND THUNDERSTORMS THIS EVENING AND TONIGHT FROM
ONGOING ACTIVITY OVER NEBRASKA AND IOWA. FURTHER OUT...A FRONTAL
BOUNDARY WILL BRING DAILY CHANCES FOR SHOWERS AND THUNDERSTORMS
THROUGH MOST OF THE EXTENDED PERIOD.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 1043 AM EDT SAT JUN 21 2014
LOW STRATUS DECK CONTINUES TO ADVANCE SOUTH TO THE NORTHEAST OF
THE INDY METRO WITHIN WEAK AREA OF COLD ADVECTION. UNDER THE CLOUD
DECK...TEMP RISES HAD BEEN STUNTED SO FAR WITH 14Z TEMPS IN THE
UPPER 60S/LOWER 70S. FURTHER SOUTH/WEST...TEMPS HAD WARMED INTO
THE MID/UPPER 70S.
WHILE SOME MVFR VISIBILITIES ARE PRESENT UNDER THE STRATUS...FOG
HAS GENERALLY DISPERSED AND HAVE REMOVED FROM THE FORECAST. WHILE
STRATUS CONTINUES TO ADVANCE SOUTH...RECENT SATELLITE TRENDS
INDICATE FRONT EDGE OF THE CLOUD DECK IS BEGINNING TO MIX OUT.
THIS TREND SHOULD CONTINUE THROUGH 18Z WITH SKIES BECOMING PARTLY
CLOUDY WITH VFR CU. THE CLOUDS THIS MORNING THOUGH ARE LIKELY TO
IMPACT OVERALL HIGHS IN THE NORTHEAST THIS AFTERNOON AND HAVE
DROPPED TEMPS A FEW DEGREES.
FOCUS THEN SHIFTS TO CONVECTIVE POTENTIAL BEGINNING LATE AFTERNOON
INTO THE EVENING HOURS. WELL DEFINED MCV LOCATED OVER EASTERN IOWA
FROM THE REMNANTS OF THE OVERNIGHT CONVECTION ACROSS NEBRASKA/
IOWA. THIS FEATURE PROGGED TO TRACK EAST INTO NORTHERN ILLINOIS
THROUGH THE AFTERNOON SPARKING NEW CONVECTIVE DEVELOPMENT.
MAJORITY OF THE MOST CURRENT MODEL DATA BRINGING CONVECTION INTO
THE NORTHERN WABASH VALLEY BY EARLY EVENING WITH STORMS CONTINUING
INTO THE OVERNIGHT. STILL A LOT OF UNCERTAINTY WITH RESPECT TO HOW
FAR SOUTH AND EAST THE CONVECTION CAN SPREAD ACROSS THE FORECAST
AREA BEFORE DYING OUT AS AIRMASS WILL REMAIN MORE STABLE THE
FURTHER EAST ONE GOES. SHORT RANGE MODEL GUIDANCE FOCUSES BETTER
INSTABILITY AND DEEPER MOISTURE IN THE VICINITY OF THE RETURNING
FRONTAL BOUNDARY ACROSS ILLINOIS THROUGH THIS EVENING...POSSIBLY
WORKING INTO THE WESTERN PART OF THE STATE AS WELL. RAP INDICATING
A SUBTLE INCREASE IN LOW LEVEL FLOW THIS EVENING WHICH WOULD
SUPPORT MAINTENANCE OF SCATTERED CONVECTION INTO THE OVERNIGHT.
DESPITE SPC BACKING OFF ON THE DAY 1 SLIGHT RISK TO JUST WEST OF
THE AREA...HAVE MAINTAINED AN ISOLATED SEVERE MENTION IN THE HWO
WITH THE BEST POTENTIAL OVER THE NORTHWEST FORECAST AREA. LOW
CONFIDENCE IN AVAILABLE FORCING AND INSTABILITY ARE MITIGATING
FACTORS IN SEVERE POTENTIAL FURTHER EAST ACROSS CENTRAL INDIANA.
ZONE AND GRID UPDATES OUT.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
ISSUED AT 322 AM EDT SAT JUN 21 2014
THE MAIN FOCUS OF THE SHORT TERM WILL BE SHOWER/THUNDERSTORM
POTENTIAL OVER WESTERN PORTIONS OF FORECAST AREA THIS EVENING
AND TONIGHT. AGAIN...DETAILS ARE UNCLEAR AT THIS TIME AS TO HOW
WAVES FROM CURRENT CONVECTIVE ACTIVITY OVER THE MID MISSOURI
VALLEY ARE GOING TO PLAY OUT AND WILL HAVE TO BE MONITORED
THROUGHOUT THE DAY.
CONFIDENCE BECOMES A BIT HIGHER LATER IN THE SHORT TERM PERIOD
THOUGH AS SURFACE FRONTAL BOUNDARY SHIFTS BACK TO THE NORTH ON
SUNDAY AND MONDAY IN THE FORM OF A WARM FRONT. THIS WILL PROVIDE
A MOIST WARM UNSTABLE ENVIRONMENT AGAIN AND FORCING FOR ADDITIONAL
SHOWER/THUNDERSTORM DEVELOPMENT.
TEMPS...HIGHS IN THE MID TO UPPER 80S AND LOWS IN THE 70S WILL
PREVAIL FOR DURATION OF SHORT TERM PERIOD...STUCK CLOSE TO A MODEL
BLEND.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
ISSUED AT 258 PM EDT SAT JUN 21 2014
THE MAIN FOCUS OF THE EXTENDED TIMEFRAME REMAINS ON RAINFALL CHANCES
ACROSS THE AREA. THE PERIOD BEGINS WITH BROAD LOW AMPLITUDE
TROUGHING OVER THE GREAT LAKES AND NORTHERN PLAINS...WITH THE
FORECAST AREA UNDER WEAK ZONAL FLOW ALOFT AND POST A WEAK FRONTAL
PASSAGE. DESPITE THE WIND SHIFT...THE WARM AND MOIST CONDITIONS WILL
CONTINUE WITH DEWPOINTS FORECAST IN THE MIDDLE TO UPPER 60 DEGREE
RANGE.
A COUPLE WEAK UPPER WAVES WILL MOVE ACROSS THE AREA BY FRIDAY
NIGHT...BEFORE UPPER RIDGING AMPLIFIES ACROSS THE MISSISSIPPI AND
OHIO RIVER VALLEYS FOR THE WEEKEND. STUCK CLOSE TO REGIONAL
INITIALIZATION FOR POPS...KEEPING SLIGHT TO MAINLY LOW CHANCE POP IN
THE FORECAST THROUGH THE EXTENDED TIMEFRAME. THE HIGHEST POPS ARRIVE
ON FRIDAY AS THE RELATIVELY STRONGER OF THE SERIES OF WEAK UPPER
WAVES MOVE ACROSS THE AREA. GENERALLY LOW TO MIDDLE 80S ARE
EXPECTED...WITH TEMPS INCREASING TO THE MIDDLE TO UPPER 80S ON
SATURDAY AS UPPER RIDGING INCREASES.
&&
.AVIATION /DISCUSSION FOR 211800Z TAF ISSUANCE/...
ISSUED AT 1253 PM EDT SAT JUN 21 2014
VFR THROUGH THE AFTERNOON AND EVENING HOURS WITH WINDS REMAINING AOB
7 KTS. COULD SEE SOME MVFR FOG DEVELOP DURING THE OVERNIGHT
ESPECIALLY AT KLAF AND KBMG BASED ON MOS...SOUNDINGS AND SIMILAR
CONDITIONS TO THIS MORNING. ALSO SOME POTENTIAL FOR CONVECTION TONIGHT BUT
RIGHT NOW LOOKS LIKE THE PROBABILITY IS LOW ENOUGH TO LEAVE OUT OF
ALL SITES BUT KLAF. AT KLAF CHANCE LOOKS HIGH ENOUGH TO INCLUDE VCTS
FROM 2-9Z AND PUT THE FOG IN AFTER THAT. AT KHUF AND KIND CURRENTLY
LEAVING VFR THROUGH THE PERIOD AS CONFIDENCE ON ANY RESTRICTIONS IS
TOO LOW TO INCLUDE. WINDS WILL BECOME SOUTHWESTERLY AROUND 5-10 KTS
BY MIDMORNING SUNDAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...TDUD
NEAR TERM...RYAN
SHORT TERM...TDUD
LONG TERM....MRD
AVIATION...CP
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1254 PM EDT SAT JUN 21 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 322 AM EDT SAT JUN 21 2014
SLIGHTLY DRIER AIR WILL BE IN PLACE FOR THE BEGINNING OF TODAY.
HOWEVER...WESTERN PORTIONS OF CENTRAL INDIANA COULD SEE SOME
SCATTERED SHOWERS AND THUNDERSTORMS THIS EVENING AND TONIGHT FROM
ONGOING ACTIVITY OVER NEBRASKA AND IOWA. FURTHER OUT...A FRONTAL
BOUNDARY WILL BRING DAILY CHANCES FOR SHOWERS AND THUNDERSTORMS
THROUGH MOST OF THE EXTENDED PERIOD.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 1043 AM EDT SAT JUN 21 2014
LOW STRATUS DECK CONTINUES TO ADVANCE SOUTH TO THE NORTHEAST OF
THE INDY METRO WITHIN WEAK AREA OF COLD ADVECTION. UNDER THE CLOUD
DECK...TEMP RISES HAD BEEN STUNTED SO FAR WITH 14Z TEMPS IN THE
UPPER 60S/LOWER 70S. FURTHER SOUTH/WEST...TEMPS HAD WARMED INTO
THE MID/UPPER 70S.
WHILE SOME MVFR VISIBILITIES ARE PRESENT UNDER THE STRATUS...FOG
HAS GENERALLY DISPERSED AND HAVE REMOVED FROM THE FORECAST. WHILE
STRATUS CONTINUES TO ADVANCE SOUTH...RECENT SATELLITE TRENDS
INDICATE FRONT EDGE OF THE CLOUD DECK IS BEGINNING TO MIX OUT.
THIS TREND SHOULD CONTINUE THROUGH 18Z WITH SKIES BECOMING PARTLY
CLOUDY WITH VFR CU. THE CLOUDS THIS MORNING THOUGH ARE LIKELY TO
IMPACT OVERALL HIGHS IN THE NORTHEAST THIS AFTERNOON AND HAVE
DROPPED TEMPS A FEW DEGREES.
FOCUS THEN SHIFTS TO CONVECTIVE POTENTIAL BEGINNING LATE AFTERNOON
INTO THE EVENING HOURS. WELL DEFINED MCV LOCATED OVER EASTERN IOWA
FROM THE REMNANTS OF THE OVERNIGHT CONVECTION ACROSS NEBRASKA/
IOWA. THIS FEATURE PROGGED TO TRACK EAST INTO NORTHERN ILLINOIS
THROUGH THE AFTERNOON SPARKING NEW CONVECTIVE DEVELOPMENT.
MAJORITY OF THE MOST CURRENT MODEL DATA BRINGING CONVECTION INTO
THE NORTHERN WABASH VALLEY BY EARLY EVENING WITH STORMS CONTINUING
INTO THE OVERNIGHT. STILL A LOT OF UNCERTAINTY WITH RESPECT TO HOW
FAR SOUTH AND EAST THE CONVECTION CAN SPREAD ACROSS THE FORECAST
AREA BEFORE DYING OUT AS AIRMASS WILL REMAIN MORE STABLE THE
FURTHER EAST ONE GOES. SHORT RANGE MODEL GUIDANCE FOCUSES BETTER
INSTABILITY AND DEEPER MOISTURE IN THE VICINITY OF THE RETURNING
FRONTAL BOUNDARY ACROSS ILLINOIS THROUGH THIS EVENING...POSSIBLY
WORKING INTO THE WESTERN PART OF THE STATE AS WELL. RAP INDICATING
A SUBTLE INCREASE IN LOW LEVEL FLOW THIS EVENING WHICH WOULD
SUPPORT MAINTENANCE OF SCATTERED CONVECTION INTO THE OVERNIGHT.
DESPITE SPC BACKING OFF ON THE DAY 1 SLIGHT RISK TO JUST WEST OF
THE AREA...HAVE MAINTAINED AN ISOLATED SEVERE MENTION IN THE HWO
WITH THE BEST POTENTIAL OVER THE NORTHWEST FORECAST AREA. LOW
CONFIDENCE IN AVAILABLE FORCING AND INSTABILITY ARE MITIGATING
FACTORS IN SEVERE POTENTIAL FURTHER EAST ACROSS CENTRAL INDIANA.
ZONE AND GRID UPDATES OUT.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
ISSUED AT 322 AM EDT SAT JUN 21 2014
THE MAIN FOCUS OF THE SHORT TERM WILL BE SHOWER/THUNDERSTORM
POTENTIAL OVER WESTERN PORTIONS OF FORECAST AREA THIS EVENING
AND TONIGHT. AGAIN...DETAILS ARE UNCLEAR AT THIS TIME AS TO HOW
WAVES FROM CURRENT CONVECTIVE ACTIVITY OVER THE MID MISSOURI
VALLEY ARE GOING TO PLAY OUT AND WILL HAVE TO BE MONITORED
THROUGHOUT THE DAY.
CONFIDENCE BECOMES A BIT HIGHER LATER IN THE SHORT TERM PERIOD
THOUGH AS SURFACE FRONTAL BOUNDARY SHIFTS BACK TO THE NORTH ON
SUNDAY AND MONDAY IN THE FORM OF A WARM FRONT. THIS WILL PROVIDE
A MOIST WARM UNSTABLE ENVIRONMENT AGAIN AND FORCING FOR ADDITIONAL
SHOWER/THUNDERSTORM DEVELOPMENT.
TEMPS...HIGHS IN THE MID TO UPPER 80S AND LOWS IN THE 70S WILL
PREVAIL FOR DURATION OF SHORT TERM PERIOD...STUCK CLOSE TO A MODEL
BLEND.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 234 AM EDT SAT JUN 21 2014
THE DETERMINISTIC EXTENDED MODELS ARE CONTINUING TO HAVE TIMING AND
RUN TO RUN DIFFERENCES OVER THE EVOLUTION OF GREAT LAKES TROUGHING
NEXT WEEK. SO...WILL ACCEPT THE REGIONAL ALLBLEND WHICH HAS CHANCE
POPS EACH PERIOD THROUGH FRIDAY ASSOCIATED WITH WAVES AROUND THE
BASE OF THE AFOREMENTIONED TROUGH COUPLED WITH A WARM...MOIST AND
UNSTABLE ENVIRONMENT.
ALLBLEND CONTINUES TO ADVERTISE THE HIGHEST POPS ON TUESDAY AS A
WEAK COLD FRONT DROPS SOUTHEAST OVER THE AREA BEFORE STALLING. A LOT
WILL DEPEND ON WHERE THIS FRONT ENDS UP LAYING OUT WHICH IS NEVER AN
EASY CALL THIS TIME OF YEAR.
SEASONABLE ALLBLEND HIGHS IN THE 80S LOOK OK FOR TEMPERATURES...AND
WITH MODEL ISSUES...DO NOT WANT TO MESS MUCH WITH THEM.
&&
.AVIATION /DISCUSSION FOR 211800Z TAF ISSUANCE/...
ISSUED AT 1253 PM EDT SAT JUN 21 2014
VFR THROUGH THE AFTERNOON AND EVENING HOURS WITH WINDS REMAINING AOB
7 KTS. COULD SEE SOME MVFR FOG DEVELOP DURING THE OVERNIGHT
ESPECIALLY AT KLAF AND KBMG BASED ON MOS...SOUNDINGS AND SIMILAR
CONDITIONS TO THIS MORNING. ALSO SOME POTENTIAL FOR CONVECTION TONIGHT BUT
RIGHT NOW LOOKS LIKE THE PROBABILITY IS LOW ENOUGH TO LEAVE OUT OF
ALL SITES BUT KLAF. AT KLAF CHANCE LOOKS HIGH ENOUGH TO INCLUDE VCTS
FROM 2-9Z AND PUT THE FOG IN AFTER THAT. AT KHUF AND KIND CURRENTLY
LEAVING VFR THROUGH THE PERIOD AS CONFIDENCE ON ANY RESTRICTIONS IS
TOO LOW TO INCLUDE. WINDS WILL BECOME SOUTHWESTERLY AROUND 5-10 KTS
BY MIDMORNING SUNDAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...TDUD
NEAR TERM...RYAN
SHORT TERM...TDUD
LONG TERM...MK
AVIATION...CP
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
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AREA FORECAST DISCUSSION
NWS TOPEKA KS
315 PM CDT Sat Jun 21 2014
.SHORT TERM...(This Evening through Sunday)
Issued at 315 PM CDT SAT JUN 21 2014
19Z water vapor imagery continues to shows a quasi-zonal flow across
the central Rockies and into the plains. There may be one or two
Mesoscale Convective Vortices (MCV) moving along the KS/NEB state
line with the more obvious one crossing the MO river and headed into
central MO. There also appears to be a subtle shortwave moving
through ID and northern UT. At the surface, a trough of low pressure
extended from the Dakotas south through eastern CO. Surface OBS show
the better low level moisture has shifted a little to the east with
much of the 70 degree dewpoints.
Late this afternoon and this evening is anticipated to be mostly dry
with general subsidence from the MCV over eastern KS and the deeper
moisture to the east of the area. This combined with a lack of
organized low level convergence should favor any isolated storms
remaining east of the forecast area. Will have to watch and see if
any of the convection off the higher terrain holds together long
enough to reach north central KS. There are some indications from
the RAP and HRRR that there could be some precip move into Republic
and Cloud counties around midnight. However those solutions seem to
be a little to aggressive in developing convection earlier in the
day, so I don`t know how much weight to give these solutions. Will
have some small POPs after midnight for far northern counties in
case some shower and thunderstorm activity is able to hang together.
Lows tonight should once again be mild with readings around 70 due to
southerly winds and warm air remaining over the area.
For Sunday, the subtle shortwave out west is progged to be moving
out into the plains, mainly to the north of the forecast area.
However the synoptic scale surface trough is expected to be a little
further east into KS. Convergence along this boundary coupled with
some weak forcing from the upper wave could cause a broken line of
storms to form by the afternoon hours. Instability is expected to be
high once again with good low level moisture still in place. However
due to weak mid level flow, deep layer shear is progged to only be
from 15 to 25 kts. This would favor multi cell clusters with a hail
and strong wind hazard. North central KS looks like the most likely
place for this storms to form during the afternoon. Temps for Sunday
are expected to be similar to today`s or maybe a degree or two
cooler. Models show a slight cooling trend at 850 and there could be
higher clouds increasing by the afternoon from the potential
convection to the west. Because of this have highs generally in the
lower 90s.
.LONG TERM...(Sunday Night through Saturday)
Issued at 315 PM CDT SAT JUN 21 2014
Overall trend is for the upper wave to be less intense as it passes
through Sunday night into early Monday. Still looks like a good
opportunity for for most locations to receive at least one round of
precip with the slow moving system weak front moving through a moist
early-summer airmass and limited inhibition. Severe weather concerns
should diminish with time in the evening hours with a least some
chance for pockets of heavier precipitation, though setup does not
point to any particularly area at this point. Monday should slowly dry
with the departing wave with Monday night and much of Tuesday still
looking to be the more likely dry periods of this forecast.
Models do show some similarities with a weak wave passing mainly
south of the area late Tuesday into Wednesday, but moisture does
return north with this wave with modest flow keeping mid levels from
warming too fast for at least small thunderstorm chances. Upper flow
amplifies over the western and eventually central CONUS into the end
of the forecast. Expect capping to increase enough for a mainly dry
end to the work week with chances picking up again by Saturday as
forcing increases. Temps should slowly warm through the latter
portions of the week, with 90s possible by Saturday.
&&
.AVIATION...(For the 18Z TAFs through 18Z Sunday Afternoon)
Issued at 1142 AM CDT SAT JUN 21 2014
Chances for TS to impact the terminals appears to be relatively
low due to no feature to focus convection. Therefore have kept a
VFR forecast through the period. For more detail, see the update
section above.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Wolters
LONG TERM...65
AVIATION...Wolters
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1110 AM MDT SAT JUN 21 2014
.UPDATE...
ISSUED AT 900 AM MDT SAT JUN 21 2014
UPDATE REQUIRED FOR THE REST OF THE DAY TO BETTER REPRESENT
CURRENT RADAR TRENDS AND THE NEXT 8-9 HOURS OF TEMPS/DP/WINDS/POP
AND WX.
SHOWERS AND THUNDERSTORMS THAT HAVE BEEN LOCATED ALONG THE KS/NE
BORDER THIS MORNING SLOWLY STARTING TO LOSE INTENSITY AND AREAL
COVERAGE AND THIS TREND SHOULD CONTINUE THE REST OF THE MORNING.
DURING THE AFTERNOON CURRENTLY EXPECTING A SFC TROUGH TO SET UP
NEAR/JUST EAST OF THE CO/KS BORDER. MAY HAVE A FEW STORMS DEVELOP
ALONG THIS BY MID/LATE AFTERNOON WITH A SLOW EASTWARD PUSH TO THE
EAST AS A STRONG WEATHER DISTURBANCE AND BETTER UPPER JET
DIVERGENCE MOVES IN TO EASTERN COLORADO. THIS SHOULD BE ENOUGH TO
CREATE SOME STRONG/SEVERE STORMS IN EASTERN COLORADO AND ALONG THE
SFC TROUGH IN WESTERN KANSAS/SOUTHWEST NEBRASKA. LARGE HAIL AND
DAMAGING WINDS WILL BE THE PRIMARY THREATS.
HIGH TEMPERATURES GENERALLY IN THE UPPER 80S TO LOW 90S IN EASTERN
COLORADO WITH LOW TO MID 90S EAST OF THE BORDER. MAY SEE SOME
UPPER 90S...ESPECIALLY ACROSS THE EAST THROUGH SOUTH WHERE IMPACTS
OF APPROACHING CIRRUS FROM THE WEST MAY BE LESS.
&&
.SHORT TERM...(TODAY THROUGH MONDAY NIGHT)
ISSUED AT 246 AM MDT SAT JUN 21 2014
A RIDGE OVER THE PLAINS WILL FLATTEN SOME TONIGHT. FLOW WILL BECOME
ZONAL ON SUNDAY AND THEN TURN NORTHWEST MONDAY/MONDAY NIGHT. A
SURFACE TROUGH WILL BE NEAR NORTHEAST COLORADO TODAY THROUGH
SUNDAY. A FRONT WILL MOVE INTO THE CENTRAL PLAINS SUNDAY
AFTERNOON. HIGH PRESSURE WILL BUILD INTO THE CENTRAL PLAINS SUNDAY
NIGHT AND CONTINUE THROUGH MONDAY NIGHT.
EARLY MORNING CONVECTION IS HANDLED WELL BY THE HRRR AND SHOULD
PERSIST ACROSS THE NORTHERN AND EASTERN ZONES TILL AROUND 16Z. POPS
WILL BE CHANCE AND LIKELY FOR THESE STORMS.
STORM INITIATION SHOULD TAKE PLACE NEAR THE SURFACE TROUGH THIS
AFTERNOON OVER EASTERN COLORADO AND EXTREME SOUTHWEST NEBRASKA.
STORMS WILL DRIFT EAST INTO THE REST OF THE FA DURING THE LATE
AFTERNOON/EVENING. SHEAR VALUES OF 30 TO 40 KTS WILL BE FAVORABLE
FOR STORMS TO BECOME SEVERE WITH LARGE HAIL AND DAMAGING WIND. CAPE
VALUES WILL RANGE FROM 1000 TO ALMOST 3000 J/KG WITH HIGHEST VALUES
OVER THE NORTHWEST FA. SUBSIDENCE WILL MOVE INTO THE FA LATE
SATURDAY NIGHT/SUNDAY MORNING SO POPS WILL BE NIL FOR THAT BRIEF
PERIOD SUNDAY MORNING. BY SUNDAY AFTERNOON THE FRONT WILL MOVE SOUTH
WITH CONVECTION ALONG AND BEHIND IT. INITIALLY STORM MOVEMENT IS
NEARLY PARALLEL TO THE FRONT IN THE AFTERNOON. HOWEVER THE MODELS
TAKE THE FRONT SOUTH ACROSS THE FA RATHER QUICKLY. BY EVENING STORM
MOVEMENT IS ALMOST PERPENDICULAR TO THE FRONT MINIMIZING ANY
TRAINING THUNDERSTORMS. PLAN TO KEEP LIKELY POPS ALONG AND BEHIND
THE FRONT WITH CHANCE POPS AHEAD OF THE FRONT. OVERNIGHT POPS WILL
DECREASE TO CHANCE AND SLIGHT CHANCE. ON MONDAY STORMS WILL DEVELOP
OVER THE HIGHER TERRAIN IN COLORADO AND DRIFT EAST. PLAN TO KEEP AT
LEAST CHANCE POPS FOR MONDAY AFTERNOON AND NIGHT.
MAX TEMPERATURES TODAY WILL RISE TO THE LOWER 90S. HIGH
TEMPERATURES SUNDAY RANGE FROM 85 TO 90. COOLER READINGS IN THE
UPPER 70S AND LOWER 80S ARE FORECAST FOR MONDAY. MIN TEMPERATURES
WILL VARY FROM THE UPPER 50S TO THE LOWER 60S.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 246 AM MDT SAT JUN 21 2014
AN UNSETTLED WEATHER PATTERN WILL CONTINUE FOR THE EXTENDED
PERIOD...WITH THE CHANCE FOR SHOWERS AND THUNDERSTORMS THROUGH
THURSDAY AND A POSSIBLE BREAK ON FRIDAY. SEVERAL SHORTWAVE TROUGHS
WILL MOVE THROUGH THE CWA...AND EVEN WITH A WEAK RIDGE MOVING OVER
THE CWA ON WEDNESDAY...SHORTWAVES EMBEDDED WITHIN THE FLOW WILL
CONTINUE THE CHANCE FOR SHOWERS AND THUNDERSTORMS. TUESDAY THROUGH
THURSDAY A LEE SURFACE LOW WILL EXIST OVER EASTERN COLORADO WITH A
QUASI STATIONARY SURFACE BOUNDARY EXTENDING SOUTHWARD FROM THE LOW.
INSTABILITY IS PRESENT OVER THE CWA THROUGHOUT THE EXTENDED...ALONG
WITH DECENT LOW LEVEL MOISTURE...AND FAVORABLE BULK SHEAR.
HOWEVER...TRYING TO TIME OUT THE PASSAGE OF EACH SHORTWAVE TROUGH
AND THE POSITION OF SURFACE BOUNDARIES IS A LITTLE DIFFICULT AT THIS
TIME...SO WILL HOLD OFF ON GETTING SPECIFIC WITH MENTION OF WHEN
SEVERE THUNDERSTORMS WILL OCCUR EVEN THOUGH IT COULD BE LIKELY
THROUGH THURSDAY. MODELS ARE NOT IN AGREEMENT WITH THE POSITION OR TIMING OF
THESE FEATURES AND MODEL SPREAD ONLY INCREASES FURTHER OUT INTO THE
EXTENDED.
FRIDAY IS KEPT DRY FOR NOW...EVEN THOUGH THE NEW RUN OF THE ECMWF HAS
A DEEP...NEGATIVELY TILTED TROUGH DIGGING FURTHER SOUTH INTO THE
SOUTHERN ROCKIES AND SOUTHWESTERN UNITED STATES. THE GFS DOES NOT
TAKE THE UPPER TROUGH THIS FAR SOUTH AND KEEPS IT IN THE PACIFIC
NORTHWEST BUT DEVELOPS A DRYLINE THURSDAY AFTERNOON THAT WAVERS BACK
WEST OVER THE CWA ON FRIDAY. AS PREVIOUSLY MENTIONED...WITH MODELS
BEING IN DISAGREEMENT THROUGHOUT THE EXTENDED...CONFIDENCE IN THE
EXTENDED FORECAST IS FAIRLY LOW. FOR THE MOST PART ACCEPTED THE
ALLBLEND...WITH A FEW MINOR ADJUSTMENTS HERE AND THERE. TEMPERATURES
WILL STEADILY INCREASE THROUGHOUT THE WEEK...WITH HIGHS IN THE LOW
TO MID 80S ON TUESDAY RISING INTO THE LOW TO MID 90S BY FRIDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1110 AM MDT SAT JUN 21 2014
SHOWERS AND THUNDERSTORMS...SOME POSSIBLY SEVERE WITH LARGE HAIL
AND DAMAGING WINDS...WILL INCREASE IN COVERAGE LATER THIS
AFTERNOON THROUGH THE EVENING HOURS AT BOTH TERMINALS AS A WEATHER
DISTURBANCE MOVES THROUGH. CURRENTLY THE BEST CHANCE IS IN THE
22Z-08Z TIME FRAME ALTHOUGH VARYING MODELS HAVE VARYING SOLUTIONS
TO THIS SO LATER REFINEMENT WILL BE NEEDED. AFTER 08Z JUST SOME
MID AND HIGH LEVEL CLOUDINESS EXPECTED. WINDS GUSTY FROM THE
EAST/SOUTHEAST FROM TAF ISSUANCE THROUGH THE REST OF THE DAY WITH
SOUTHERLY WINDS AROUND 10KTS TONIGHT. ON SUNDAY WINDS SHIFT TO THE
NORTHWEST AT 10-15KTS AT KGLD AROUND 15Z WHILE REMAINING
LIGHT/VARIABLE AT KMCK.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...99
SHORT TERM...FS
LONG TERM...ALW
AVIATION...99
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1142 AM CDT Sat Jun 21 2014
.UPDATE...
Issued at 1142 AM CDT SAT JUN 21 2014
Whatever outflow boundary that was left from this morning`s
convection appears to be losing definition as there is only a weak
gradient in temp and dewpoint across the forecast area. Profiler
data suggests that northeast KS may still be on the back side of
an MCV generated from the morning convection. So weak subsidence
maybe why there is not much of a CU field developing yet. Latest
model trends continue to struggle with location of isolated
convection due to a lack of large scale forcing or surface feature
to focus convergence. Additionally differences in how deep the
boundary layer mixes out has an impact on how much inhibition the
models have, and the NAM now is showing weak inhibition through
the afternoon. In general nothing shows strong low level
convergence across the area this afternoon, except the RAP which
generates an outflow from convection over the KC area. With little
confidence in the RAP and no obvious forcing or lift, think the
afternoon is likely to remain dry. However it is difficult to
completely rule out an isolated storm so will continue to monitor
trends.
&&
.SHORT TERM...(Today and Tonight)
Issued at 4 AM CDT SAT JUN 21 2014
The mid-level flow was fairly zonal across much of the CONUS this
morning as a broad ridge stretched across the southern U.S. and the
mid-level low shifted northward into south central Canada. However,
within this zonal flow several embedded shortwaves were present,
with one of those stronger waves helping to create a complex of
thunderstorms over much of central and eastern Nebraska. Early this
morning these thunderstorms extended southward toward the
Kansas/Nebraska border and into far northern Kansas. However, the
regional radar loop showed the outflow from the storms excelling
well out and ahead of the line of storms, so a weakening trend has
been noted in this thunderstorm activity. While much of this
precipitation is expected to diminish just after sunrise, the
regional radar loop at 09z was showing showers and thunderstorms
over south central Nebraska extending southward into far northern
Kansas. Some short range models hold this batch of precipitation
together as it progresses eastward into north central Kansas before
dissipating by mid morning, so will need to monitor this trend this
morning.
For today and tonight, several weak embedded shortwaves will
continue to traverse across the northern edge of the broad mid-level
ridge, which will likely skim near the Kansas/Nebraska border. The
surface pattern should remain fairly unchanged through tonight with
high pressure anchored over the southeastern U.S. and surface low
pressure across eastern Colorado and western Kansas with a fairly
stationary boundary extending into western Nebraska. With the
exception of a few lingering showers and thunderstorms potentially
across far northern Kansas this morning, the region is expected to
remain dry through the day and into the evening hours. Models show
showers and thunderstorms igniting along this stationary boundary
over western Nebraska and western Kansas tonight, with this activity
being further supported by a stronger embedded shortwave. Latest
model trends have this precipitation advancing eastward into north
central Kansas during the overnight hours into Sunday morning, so
have slight to low-end chance PoPs in for north central Kansas
toward extreme northeast Kansas during that time frame. With model
soundings showing the cap building back in during the overnight
hours, any thunderstorms that develop will likely be elevated.
MUCAPE values may be upwards of 1000-2000J/kg, however the 0-6km
bulk shear looks to be very weak at 20kts or less so do not
anticipate severe weather with this overnight activity.
Despite model soundings showing some mid and high clouds building in
across the region through the day, decent south-southwesterly flow
should help to keep temperatures mild in the low to mid 90s. With
dewpoint temperatures remaining in the mid 60s to low 70s, could see
heat indices this afternoon reaching into the upper 90s to near 100
degrees. Steady southerly flow tonight will keep low temperatures
mild once again with lows in the low 70s.
.LONG TERM...(Sunday through Friday)
Issued at 4 AM CDT SAT JUN 21 2014
Not a lot has changed in the mid/long term forecast. The most
significant weather maker appears on track to impact the area late
Sunday into Monday, and then have some less certain low-end
precip chances later in the week.
Sunday should start with thunderstorm activity to the north in
Nebraska in one or more complexes in the vicinity of a diffuse
surface front. This front should become more well defined and
shift to the south through the day as weak height falls spread
into Kansas and a lee cyclone moves into southwest Kansas. Model
guidance is consistent in bringing the front into north central
Kansas by mid to late afternoon on Sunday. This should allow
plenty of time for heating in advance of the best forcing and
expect a broad area of moderate to strong instability across the
forecast area...with some extreme instability by late afternoon
near the frontal boundary. Inhibition may be reduced enough even
south of the front for scattered thunderstorm development on
Sunday afternoon, but this would seem to be slight chance unless
some outflow can push south and enhance the convergence. Greatest
precip chances should hold in the northwest 1/4 of the forecast
area through the afternoon, and spread southeast during the
evening/overnight hours. While there will be ample instability,
the wind shear even in the presence of the incoming short wave
trough will be weak...unlikely to exceed 30 kts of effective
shear. This should result in multicell storm structure with some
small potential for the strongest storms to produce marginally
severe hail or periods of damaging winds. Widespread severe
weather is unlikely.
This storm system will be comprised of more than one weak short
wave moving through the weak broad trough, and thus expect multiple
rounds of thunderstorms through Monday afternoon. PWAT values are
likely to exceed 1.5 inches and may be closer to 2 inches at
times...especially Sunday night. The weak wind fields will promote
a relatively slow storm motion while a moderate low level jet
could orient favorably for periods of training storms. It`s not
an optimal setup, but some ingredients are present for a heavy
rain event, possibly enough to lead to some flooding.
The trough axis should pass through the area by late Monday, with
a dry period expected through Tuesday. How long this dry period
lasts is uncertain as there are indications of additional pieces
of upper level energy impacting the central Plains by Tuesday
night into Wednesday. Uncertainty increases further by late in the
week as there are indications of a deeper trough building into the
western CONUS with southwest flow aloft and lead short waves
ejecting across the Plains. Forecasting the strength of the
trough and a southeastern CONUS ridge is where model guidance
diverges at this time, and will have a pronounced impact on the
local forecast. All told, precip chances do not look substantial,
but are warranted for much of the Thurs/Fri period. A warming
trend in temperatures as well as increased low level moisture is
also expected for Thursday and Friday.
&&
.AVIATION...(For the 18Z TAFs through 18Z Sunday Afternoon)
Issued at 1142 AM CDT SAT JUN 21 2014
Chances for TS to impact the terminals appears to be relatively
low due to no feature to focus convection. Therefore have kept a
VFR forecast through the period. For more detail, see the update
section above.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...Wolters
SHORT TERM...Hennecke
LONG TERM...Barjenbruch
AVIATION...Wolters
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
615 PM EDT Sat Jun 21 2014
...Forecast Update...
Issued at 614 PM EDT Sat Jun 21 2014
Quick update this evening to account for ongoing trends. Despite a
few very isolated light showers, precipitation has ended across
southern KY. Therefore, will remove precip mention from the
forecast for the remainder of the evening hours. Attention will
then turn to the northwest as a line of showers and thunderstorms
continues to develop across IL/MO. The main forecast challenge
tonight will be just how far east that convection makes it. Given
it will be fighting much drier air that has protruded into southern
IN and into southern IL, think this convection will likely struggle
as it pushes east. However, the latest HRRR which has a good handle
on the current convection, does bring a weakening line into southern
IN around 06Z overnight. Given the drier air firmly in place, will
continue with a dry forecast but will continue to monitor trends
over the next few hours.
.SHORT TERM (Now through Sunday Night)...
Issued at 300 PM EDT Sat Jun 21 2014
The upper air pattern shows a progressive relatively flat flow at
500mb confined generally to the northern tier of states. Weak
northwest flow currently over the northern Ohio Valley will become
weaker as ridging is forecast to develop across the Lower
Mississippi Valley by late Sunday, extending northeastwards through
southern Indiana.
Expect only a few flat cumulus this afternoon along and north of
Interstate 64 as the shortwave that brought scattered thunderstorms
earlier this morning to the Lake Cumberland Region moves farther
southeast. Any additional isolated thunderstorms through late
afternoon will stay along and southeast of the Cumberland Parkway.
Expect mostly clear skies tonight with humid conditions and light
winds. Some patchy fog may once again develop across southern
Indiana and the Bluegrass Region, although not to the extent of
earlier this morning. Lows tonight will range from the mid 60s
across the Bluegrass and southern Indiana to near 70 elsewhere.
Despite adequate moisture and quite unstable conditions developing
Sunday afternoon, ridging aloft will inhibit any widespread
convection. Think that scattered thunderstorms may develop farther
north across Illinois and Indiana, with isolated storms at best
along and north of the Ohio River. Expect south central Kentucky to
stay dry. Highs Sunday will range from the upper 80s northeast to
the lower 90s southwest. Light south winds will develop Sunday
afternoon.
.LONG TERM (Monday through Saturday)...
Issued at 255 PM EDT Sat Jun 21 2014
Fairly typical summertime conditions expected for most of the
upcoming week, with a low-amplitude and somewhat progressive pattern
aloft.
Shortwave ridging on Monday will most likely allow for the warmest
temps of the week. However, the pattern is still just flat enough
and heights not getting into legitimate heat wave territory, so
expect temps to reach the lower 90s in most spots. This stays in
line with the more consistent and slightly cooler NAM MOS. Chance
POPs will re-enter the picture Monday afternoon as the ridging
begins to gradually weaken.
Best chance for showers and storms will be Tuesday into Tuesday
night, with the passage of an upper shortwave trof. High PWATs will
support a heavy rain and pulse wind threat.
The rest of the week will not see any real pattern change, but just
warm and humid conditions with isolated/scattered storms each day,
mainly in the afternoons.
Pattern aloft starts to amplify toward the end of the week with a
ridge nosing up into the Upper Midwest. This bears watch for a
possible break in our daily convection and temps possibly punching
back into the 90s at some point next weekend.
&&
.AVIATION (18Z TAF Update)...
Issued at 125 PM EDT Sat Jun 21 2014
Partly cloudy skies with some fair-weather cumulus will continue
this afternoon, clearing by early to mid evening. Overnight, expect
mostly clear skies and light patchy ground fog which will not become
nearly as dense as it became earlier this morning.
Winds will stay northerly at 5 to 10 mph through early evening, then
become calm or light easterly overnight, and eventually become very
light southerly Sunday afternoon. Widely scattered thunderstorms are
possible Sunday afternoon and evening. However coverage and
confidence are low and will not put in TAFs at this time.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Update.........KJD
Short Term.....JSD
Long Term......RAS
Aviation.......JSD
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
400 PM CDT Sat Jun 21 2014
.DISCUSSION...
Issued at 359 PM CDT SAT JUN 21 2014
What else would one expect for the official first day of summer
other than an uncapped tropical airmass defined by high CAPEs and
weak shear with isolated convection along weak boundaries. Very weak
and isolated convection continues to sputter across northern MO this
afternoon in a region of weak h8 convergence. Increasing convection
is noted in a region of moderate h8 moisture convergence which
extends southwest from west central IL cluster into the east central
CWA. HRRR has been picking out this general area for most of today.
Will focus higher PoPs for the late afternoon and early evening
hours this area. A small MCV over south central NE left over from
earlier convection is drifting east towards slightly higher MLCAPEs
around 2000 J/kg. Will insert low chance PoPs for this evening for
nw and north central MO for possible convective development. Last
several runs of the HRRR generates scattered convection this area.
Expect another complex convective scenario tonight. Current
convection over the NE Panhandle may eventually merge with another
nocturnal MCS that rolls off the CO Front Range and heads east. Will
throw in some PoPs over northwest MO towards Sunday morning to cover
the possibility of a dying MCS reaching the CWA.
Continued very warm and humid on Sunday with above average
temperatures. Low confidence on placement of PoPs as any outflow
boundaries left over from tonights convection will play a key role.
Sunday night into Monday still holds the highest PoPs during this
forecast period. While the models have started to diverge on where
another nocturnal MCS will track there is good consensus that a cold
front moving southeast through NE/IA/KS will play a pivotal role.
Have had to lower qpf during this period as confidence on a large
MCS moving through the CWA has diminished. But should see good
coverage of convection with the front. High precipitable water
values are a concern should storms crawl through or back build along
the front. So, later forecasts may need to ramp qpf back up.
While Tuesday looks dry and a tad cooler behind the front weak
embedded disturbances within the quasi-zonal pattern will provide
alot of uncertainty on timing and location of any convection for
Wednesday/Wednesday night.
The upper pattern evolves for the latter half of the week as an
upper trough pushes through the intermountain region. The backing
flow downstream will enable a southwesterly fetch to spread through
the Central Plains and Mid MO Valley. Should see a slight uptick in
temperatures and humidity with warmer air aloft spreading into the
CWA and forcing any convection to become elevated and more nocturnal.
&&
.AVIATION...(For the 18Z TAFS through 18Z Sunday Afternoon)
Issued at 1238 PM CDT SAT JUN 21 2014
Will maintain the going VFR forecast. Isolated to scattered
convection possible across northern MO this afternoon. Activity should remain
north of the terminals, especially KMCI/KMKC. Will be monitoring the
current activity moving east into far northwest MO.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
UPDATE...MJ
DISCUSSION...MJ
AVIATION...MJ
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
105 PM CDT SAT JUN 21 2014
.UPDATE...
ISSUED AT 1109 AM CDT SAT JUN 21 2014
FORECAST HAS BEEN UPDATED FOR PRECIPITATION TRENDS. STILL THINKING
THE PRIMARY ACTIVITY WILL BE STORMS DEVELOPING ALONG THE MAIN
SHORTWAVE TROUGH MOVING OUT OF THE ROCKIES WHICH WILL MOVE ACROSS
NEBRASKA THIS EVENING AND OVERNIGHT. WHAT IS MORE OF A QUESTION IS
IF THERE WILL BE ANY DEVELOPMENT AHEAD OF THE MAIN SHORTWAVE THIS
AFTERNOON. THE HRRR HAS BEEN CONSISTENT SHOWING A MOISTURE
BOUNDARY FROM ROUGHLY DEUEL COUNTY UP TO AROUND VALENTINE THIS
AFTERNOON AS DRY AIR MIXES DOWN TO THE SURFACE BEHIND THE LINE AND
MOISTURE CONTINUES TO SURGE NORTH AHEAD OF THE SURFACE LOW OVER
COLORADO. HOWEVER...IT HAS BEEN BACK AND FORTH WITH DEVELOPING A
FEW STORMS ON THIS BOUNDARY. UPPER LEVEL SUPPORT FROM THIS ISN/T
GREAT BUT WITH THERE ARE MULTIPLE WEAK SHORTWAVES COMING OUT OF
THE CENTRAL ROCKIES THAT WILL LIKELY BE OVER THE AREA EARLIER THIS
AFTERNOON WHICH COULD BE JUST ENOUGH TO HELP STORMS DEVELOP AS THE
CAP BREAKS. DID WANT TO AT LEAST HAVE A CHANCE FOR STORMS EARLIER
IN THE AFTERNOON IN AREAS FURTHER EAST THAN WERE IN THE PREVIOUS
FORECAST WITH THIS CONCERN. ALSO...EXPANDED THE WORDING FOR SEVERE
STORMS POSSIBLE ACROSS ALL OF THE FORECAST AREA AS CONDITIONS WILL
BE FAVORABLE ACROSS THE ENTIRE AREA FOR STORMS TO BECOME SEVERE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 346 AM CDT SAT JUN 21 2014
THE MCS ACROSS NORTHEAST COLORADO IS CLEARLY SHOWING CYCLONIC
ROTATION ON RADAR AND IS TRACKING EAST NORTHEAST TOWARD SWRN NEB
THIS MORNING. THE FORECAST TRACKS IT THROUGH SWRN NEB THIS MORNING
AND ALLOWS FOR DECAY BY 14Z-15Z. THE RAP AND HRRR MODELS DO NOT
HANDLE THIS FEATURE SO THE FORECAST IS HAND DRAWN FOR NOW WITH
SCATTERED POPS BECOMING ISOLATED.
AN ACTIVE SEVERE WEATHER DAY IS EXPECTED THIS AFTERNOON AND TONIGHT.
THE MODEL CONSENSUS SUGGESTS STORMS WOULD FIRE ACROSS NORTHWEST
NEBRASKA AROUND 21Z AND GROW UPSCALE EAST AND SOUTHEAST THROUGHOUT
THE EVENING HOURS. THE MODELS ARE STRUGGLING WITH TEMPERATURES AND
DEW POINTS. THE HRRR...GEMREG AND ECM SEEMED TO HAVE A BETTER HANDLE
ON DEW POINTS AND DEVELOP VERY HIGH SFC BASED CAPE ACROSS WRN/NCNTL
NEB. VALUES OF 3000-4000 J/KG DEVELOP WITH LITTLE OR NO CAP WHICH IS
CONSISTENT WITH THE AFTN CONDITIONS LATELY.
A STRONG MID LEVEL DISTURBANCE...CURRENTLY ACROSS NRN NEVADA WILL BE
CROSSING THE CNTL/NRN PLAINS LATE THIS AFTN AND A PACIFIC COLD FRONT
SWEEPS PART WAY THRU THE FCST AREA TONIGHT. THIS SETS UP A BROAD AND
WEAKLY CAPPED WARM SECTOR COVERING MOST OF THE FCST AREA THIS AFTN.
THE NAM AND RAP MODELS BACK THE SFC WINDS ACROSS NRN NEBRASKA THIS
AFTN HEIGHTENING THE SEVERE WEATHER THREAT. IN GENERAL WINDS ALOFT
ARE WEAK IN THE MODEL SOLNS BUT GIVEN THE STRENGTH OF THE UPPER
LEVEL DISTURBANCE ACROSS THE WRN U.S. THE SHEAR COULD BE STRONGER
TODAY THAN FRIDAY.
THERE IS A BROAD SPREAD IN BULK SHEAR SHOWN IN THE MODELS AT 00Z
THIS EVENING RANGING FROM LESS THAN 20 KT TO 35 KT AT BOTH NORTH
PLATTE AND VALENTINE. USING THE HIGHER VALUES SUGGESTS POTENTIAL FOR
SUPERCELL DEVELOPMENT AT BOTH LOCATIONS BUT THIS WOULD BE MORE
LIKELY ACROSS THE WEST WITH THE SYSTEM EVOLVING INTO A QLMCS AS IT
MOVES EAST INTO DEEPER MOISTURE ACROSS NCNTL NEB THIS EVENING. SPC
REMAINS UNCERTAIN ON HOW THIS SYSTEM WILL EVOLVE SINCE THE MODELS
SHOW A FULL SPECTRUM OF CONVECTIVE OPPORTUNITIES ACROSS THE BLACK
HILLS AND THE NEBRASKA PANHANDLE TODAY.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 346 AM CDT SAT JUN 21 2014
12Z SUNDAY AND BEYOND. THE FOCUS OF EXTENDED PERIODS...AT LEAST
INITIALLY...WILL BE ON THE TIMING AND LOCATION OF A FRONTAL
BOUNDARY POISED TO CROSS WESTERN AND NORTH CENTRAL NEBRASKA
SUNDAY. CONTRARY TO PREVIOUS MODEL RUNS...THE SOLUTIONS NOW SEEM
TO KEEP THE FRONT MOVING THROUGH THE CWA FAIRLY
PROGRESSIVELY...BUT THERE REMAINS CONSIDERABLE UNCERTAINTY ON HOW
SUNDAY WILL PLAY OUT...ESPECIALLY SINCE A FAIRLY SIGNIFICANT MCS
IS SHOWN TO DEVELOP SATURDAY NIGHT/EARLY SUNDAY ACROSS MUCH OF THE
CENTRAL SANDHILLS AND PROJECT EAST OVERNIGHT. THUS CONFIDENCE IS
SOMEWHAT LOWER THAN USUAL...BUT WHERE STORMS FIRE SUNDAY
AFTERNOON...STEEP LAPSE RATES...A MODERATE TO STRONGLY UNSTABLE
ATMOSPHERE AND SUFFICIENT SHEAR WOULD PROMOTE MULTI CELL UPDRAFTS
CAPABLE OF LARGE HAIL AND GUSTY WIND. GIVEN THE CURRENT
UNCERTAINTY...FELT THAT SUB 50 PERCENT POPS WERE ALL THAT WERE
NEEDED BEFORE 00Z MONDAY. THEREAFTER...THERE IS SOME AGREEMENT IN
THE SOLUTIONS THAT STORMS WILL FOCUS ACROSS OUR EASTERN AND
SOUTHERN ZONES...FOR THIS AREA WILL MAINTAIN HIGH END CHANCE
POPS...BUT NOT VENTURE INTO THE LIKELY REALM YET.
THE GREATEST CHANGE MADE TO THE INHERITED FORECAST IS NOTED ON
MONDAY AS THE SURFACE BOUNDARY IS NOW SHOWN TO BE WELL SOUTH AND
EAST OF THE CWA...THUS POPS WERE LOWERED TO ACCOUNT FOR THIS NEW
MODEL PROJECTION. WITHIN THE POST FRONTAL AIRMASS ON MONDAY AND
TUESDAY...TEMPERATURES WILL BE PLEASANT...WITH HIGHS GENERALLY IN
THE 70S FOR MOST LOCATIONS.
NORTHWEST FLOW ALOFT DEVELOPS ACROSS THE HIGH PLAINS EARLY NEXT WEEK
AS A NORTHERN PLAINS LOW DROPS SOUTH INTO THE EASTERN DAKOTAS...WITH
RIDGING NOSING INTO THE CENTRAL ROCKIES. WEAK EASTERLY UPSLOPE FLOW
WILL INTERACT WITH STRONG WARMING OFF THE HIGH PLAINS OF EASTERN
COLORADO/WYOMING TO PROMOTE STORM DEVELOPMENT MONDAY AFTERNOON. A
FEW OF THESE STORMS COULD DRIFT SOUTHEAST INTO WESTERN/SOUTHWEST
PORTIONS OF THE CWA WITH A STRONG OR LOW END SEVERE STORM POSSIBLE.
NORTHWEST FLOW CONTINUES TO DIRECT WEAK IMPULSES ACROSS THE HIGH
PLAINS INTO CENTRAL SANDHILLS...ADDITIONAL STORM CHANCES WILL BE
POSSIBLE THROUGH MID-WEEK. THEREAFTER...SUPPORT REMAINS FOR A
DEEPENING TROUGH ACROSS THE WESTERN CONUS...WHICH WOULD PROMOTE
SOUTHWEST FLOW ATOP THE CENTRAL PLAINS...SOUTHERLY SURFACE FLOW
RETURNS. THE PATTEN MAY RETURN ACTIVE LATE WEEK AS ADDITIONAL
ENERGY/EML IS DIRECTED NORTHEAST FROM THE WESTERN CONUS TROUGH TOWARD
THE CENTRAL PLAINS. AFTER HIGHS IN THE 70S EARLY NEXT
WEEK...TEMPERATURES GRADUALLY WARM INTO THE UPPER 80S TO LOWER 90S
BY LATE...LOWS TO REMAIN SEASONAL THROUGH THE EXTENDED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 104 PM CDT SAT JUN 21 2014
VFR CONDITIONS EARLY THIS AFTERNOON ACROSS NEBRAKSA...BUT
THUNDERSTORMS BECOME LIKELY FOR MUCH OF THE STATE THIS EVENING AND
OVERNIGHT. THERE REMAINS CHANCES FOR ISOLATED TO SCATTERED
COVERAGE OF STRONG THUNDERSTORMS LATE THIS AFTERNOON AHEAD OF THE
MAIN WAVE OF STORMS THAT WILL MOVE ACROSS NEBRASKA TONIGHT. STORMS
COULD BECOME STRONG...WITH STRONG WINDS AND HEAVY RAIN...AS WELL
AS SOME LARGE HAIL IN THE STRONGEST STORMS. THERE SHOULD BE A
BREAK FROM THE STORMS AND RAIN...WITH CONDITIONS IMPROVING TO VFR
BY THE EARLY MORNING HOURS ON SUNDAY HOWEVER MORE SHOWERS AND
STORMS ARE EXPECTED TO MOVE INTO THE AREA...ESPECIALLY OVER
NORTHERN NEBRASKA BY 18Z SUNDAY.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BROOKS
SHORT TERM...CDC
LONG TERM...JACOBS
AVIATION...BROOKS
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1109 AM CDT SAT JUN 21 2014
.UPDATE...
ISSUED AT 1109 AM CDT SAT JUN 21 2014
FORECAST HAS BEEN UPDATED FOR PRECIPITATION TRENDS. STILL THINKING
THE PRIMARY ACTIVITY WILL BE STORMS DEVELOPING ALONG THE MAIN
SHORTWAVE TROUGH MOVING OUT OF THE ROCKIES WHICH WILL MOVE ACROSS
NEBRASKA THIS EVENING AND OVERNIGHT. WHAT IS MORE OF A QUESTION IS
IF THERE WILL BE ANY DEVELOPMENT AHEAD OF THE MAIN SHORTWAVE THIS
AFTERNOON. THE HRRR HAS BEEN CONSISTENT SHOWING A MOISTURE
BOUNDARY FROM ROUGHLY DEUEL COUNTY UP TO AROUND VALENTINE THIS
AFTERNOON AS DRY AIR MIXES DOWN TO THE SURFACE BEHIND THE LINE AND
MOISTURE CONTINUES TO SURGE NORTH AHEAD OF THE SURFACE LOW OVER
COLORADO. HOWEVER...IT HAS BEEN BACK AND FORTH WITH DEVELOPING A
FEW STORMS ON THIS BOUNDARY. UPPER LEVEL SUPPORT FROM THIS ISN/T
GREAT BUT WITH THERE ARE MULTIPLE WEAK SHORTWAVES COMING OUT OF
THE CENTRAL ROCKIES THAT WILL LIKELY BE OVER THE AREA EARLIER THIS
AFTERNOON WHICH COULD BE JUST ENOUGH TO HELP STORMS DEVELOP AS THE
CAP BREAKS. DID WANT TO AT LEAST HAVE A CHANCE FOR STORMS EARLIER
IN THE AFTERNOON IN AREAS FURTHER EAST THAN WERE IN THE PREVIOUS
FORECAST WITH THIS CONCERN. ALSO...EXPANDED THE WORDING FOR SEVERE
STORMS POSSIBLE ACROSS ALL OF THE FORECAST AREA AS CONDITIONS WILL
BE FAVORABLE ACROSS THE ENTIRE AREA FOR STORMS TO BECOME SEVERE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 346 AM CDT SAT JUN 21 2014
THE MCS ACROSS NORTHEAST COLORADO IS CLEARLY SHOWING CYCLONIC
ROTATION ON RADAR AND IS TRACKING EAST NORTHEAST TOWARD SWRN NEB
THIS MORNING. THE FORECAST TRACKS IT THROUGH SWRN NEB THIS MORNING
AND ALLOWS FOR DECAY BY 14Z-15Z. THE RAP AND HRRR MODELS DO NOT
HANDLE THIS FEATURE SO THE FORECAST IS HAND DRAWN FOR NOW WITH
SCATTERED POPS BECOMING ISOLATED.
AN ACTIVE SEVERE WEATHER DAY IS EXPECTED THIS AFTERNOON AND TONIGHT.
THE MODEL CONSENSUS SUGGESTS STORMS WOULD FIRE ACROSS NORTHWEST
NEBRASKA AROUND 21Z AND GROW UPSCALE EAST AND SOUTHEAST THROUGHOUT
THE EVENING HOURS. THE MODELS ARE STRUGGLING WITH TEMPERATURES AND
DEW POINTS. THE HRRR...GEMREG AND ECM SEEMED TO HAVE A BETTER HANDLE
ON DEW POINTS AND DEVELOP VERY HIGH SFC BASED CAPE ACROSS WRN/NCNTL
NEB. VALUES OF 3000-4000 J/KG DEVELOP WITH LITTLE OR NO CAP WHICH IS
CONSISTENT WITH THE AFTN CONDITIONS LATELY.
A STRONG MID LEVEL DISTURBANCE...CURRENTLY ACROSS NRN NEVADA WILL BE
CROSSING THE CNTL/NRN PLAINS LATE THIS AFTN AND A PACIFIC COLD FRONT
SWEEPS PART WAY THRU THE FCST AREA TONIGHT. THIS SETS UP A BROAD AND
WEAKLY CAPPED WARM SECTOR COVERING MOST OF THE FCST AREA THIS AFTN.
THE NAM AND RAP MODELS BACK THE SFC WINDS ACROSS NRN NEBRASKA THIS
AFTN HEIGHTENING THE SEVERE WEATHER THREAT. IN GENERAL WINDS ALOFT
ARE WEAK IN THE MODEL SOLNS BUT GIVEN THE STRENGTH OF THE UPPER
LEVEL DISTURBANCE ACROSS THE WRN U.S. THE SHEAR COULD BE STRONGER
TODAY THAN FRIDAY.
THERE IS A BROAD SPREAD IN BULK SHEAR SHOWN IN THE MODELS AT 00Z
THIS EVENING RANGING FROM LESS THAN 20 KT TO 35 KT AT BOTH NORTH
PLATTE AND VALENTINE. USING THE HIGHER VALUES SUGGESTS POTENTIAL FOR
SUPERCELL DEVELOPMENT AT BOTH LOCATIONS BUT THIS WOULD BE MORE
LIKELY ACROSS THE WEST WITH THE SYSTEM EVOLVING INTO A QLMCS AS IT
MOVES EAST INTO DEEPER MOISTURE ACROSS NCNTL NEB THIS EVENING. SPC
REMAINS UNCERTAIN ON HOW THIS SYSTEM WILL EVOLVE SINCE THE MODELS
SHOW A FULL SPECTRUM OF CONVECTIVE OPPORTUNITIES ACROSS THE BLACK
HILLS AND THE NEBRASKA PANHANDLE TODAY.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 346 AM CDT SAT JUN 21 2014
12Z SUNDAY AND BEYOND. THE FOCUS OF EXTENDED PERIODS...AT LEAST
INITIALLY...WILL BE ON THE TIMING AND LOCATION OF A FRONTAL
BOUNDARY POISED TO CROSS WESTERN AND NORTH CENTRAL NEBRASKA
SUNDAY. CONTRARY TO PREVIOUS MODEL RUNS...THE SOLUTIONS NOW SEEM
TO KEEP THE FRONT MOVING THROUGH THE CWA FAIRLY
PROGRESSIVELY...BUT THERE REMAINS CONSIDERABLE UNCERTAINTY ON HOW
SUNDAY WILL PLAY OUT...ESPECIALLY SINCE A FAIRLY SIGNIFICANT MCS
IS SHOWN TO DEVELOP SATURDAY NIGHT/EARLY SUNDAY ACROSS MUCH OF THE
CENTRAL SANDHILLS AND PROJECT EAST OVERNIGHT. THUS CONFIDENCE IS
SOMEWHAT LOWER THAN USUAL...BUT WHERE STORMS FIRE SUNDAY
AFTERNOON...STEEP LAPSE RATES...A MODERATE TO STRONGLY UNSTABLE
ATMOSPHERE AND SUFFICIENT SHEAR WOULD PROMOTE MULTI CELL UPDRAFTS
CAPABLE OF LARGE HAIL AND GUSTY WIND. GIVEN THE CURRENT
UNCERTAINTY...FELT THAT SUB 50 PERCENT POPS WERE ALL THAT WERE
NEEDED BEFORE 00Z MONDAY. THEREAFTER...THERE IS SOME AGREEMENT IN
THE SOLUTIONS THAT STORMS WILL FOCUS ACROSS OUR EASTERN AND
SOUTHERN ZONES...FOR THIS AREA WILL MAINTAIN HIGH END CHANCE
POPS...BUT NOT VENTURE INTO THE LIKELY REALM YET.
THE GREATEST CHANGE MADE TO THE INHERITED FORECAST IS NOTED ON
MONDAY AS THE SURFACE BOUNDARY IS NOW SHOWN TO BE WELL SOUTH AND
EAST OF THE CWA...THUS POPS WERE LOWERED TO ACCOUNT FOR THIS NEW
MODEL PROJECTION. WITHIN THE POST FRONTAL AIRMASS ON MONDAY AND
TUESDAY...TEMPERATURES WILL BE PLEASANT...WITH HIGHS GENERALLY IN
THE 70S FOR MOST LOCATIONS.
NORTHWEST FLOW ALOFT DEVELOPS ACROSS THE HIGH PLAINS EARLY NEXT WEEK
AS A NORTHERN PLAINS LOW DROPS SOUTH INTO THE EASTERN DAKOTAS...WITH
RIDGING NOSING INTO THE CENTRAL ROCKIES. WEAK EASTERLY UPSLOPE FLOW
WILL INTERACT WITH STRONG WARMING OFF THE HIGH PLAINS OF EASTERN
COLORADO/WYOMING TO PROMOTE STORM DEVELOPMENT MONDAY AFTERNOON. A
FEW OF THESE STORMS COULD DRIFT SOUTHEAST INTO WESTERN/SOUTHWEST
PORTIONS OF THE CWA WITH A STRONG OR LOW END SEVERE STORM POSSIBLE.
NORTHWEST FLOW CONTINUES TO DIRECT WEAK IMPULSES ACROSS THE HIGH
PLAINS INTO CENTRAL SANDHILLS...ADDITIONAL STORM CHANCES WILL BE
POSSIBLE THROUGH MID-WEEK. THEREAFTER...SUPPORT REMAINS FOR A
DEEPENING TROUGH ACROSS THE WESTERN CONUS...WHICH WOULD PROMOTE
SOUTHWEST FLOW ATOP THE CENTRAL PLAINS...SOUTHERLY SURFACE FLOW
RETURNS. THE PATTEN MAY RETURN ACTIVE LATE WEEK AS ADDITIONAL
ENERGY/EML IS DIRECTED NORTHEAST FROM THE WESTERN CONUS TROUGH TOWARD
THE CENTRAL PLAINS. AFTER HIGHS IN THE 70S EARLY NEXT
WEEK...TEMPERATURES GRADUALLY WARM INTO THE UPPER 80S TO LOWER 90S
BY LATE...LOWS TO REMAIN SEASONAL THROUGH THE EXTENDED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 623 AM CDT SAT JUN 21 2014
VFR IS EXPECTED ALL AREAS THROUGH 20Z. THEREAFTER SCATTERED STRONG
TO SEVERE TSTMS ARE EXPECTED TO DEVELOP IN THE PANHANDLE WHICH
WILL MOVE EAST AND BECOME NUMEROUS ACROSS NCNTL NEB BY 23Z-01Z.
STORM ACTIVITY WILL PROGRESS EAST THROUGHOUT THE EVENING AND EXIT
THE FCST AREA BY 06Z-12Z SUNDAY.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BROOKS
SHORT TERM...CDC
LONG TERM...JACOBS
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1250 PM CDT SAT JUN 21 2014
.UPDATE...
ISSUED AT 1230 PM CDT SAT JUN 21 2014
CURRENT SURFACE ANALYSIS SHOWS FRONTAL BOUNDARY HAS WORKED ITS WAY
INTO FAR WRN ND...WHILE MOISTURE CONTINUES TO PUSH ITS WAY INTO
CTRL/ERN ND. HAVE DECIDED TO PUSH OUT A FLASH FLOOD WATCH OVER
PTNS OF S CTRL ND INTO THE JAMES RIVER VALLEY GIVEN PLENTY OF
MOISTURE ON HAND FOR STORMS TO WORK WITH COMBINED WITH WET SOILS.
LATEST GUIDANCE SUGGESTS STORMS SHOULD NOT BE STATIONARY...BUT
TRAINING WILL BE POSSIBLE ALONG WITH SOME STORMS BEING PROLIFIC
RAIN PRODUCERS. ALONG WITH THE FLOOD THREAT...STILL HAVE THE
HAIL/WIND THREAT OVER SIMILAR AREAS AS GUIDANCE STILL SHOWS GOOD
INSTABILITY/SHEAR. UPDATES HAVE BEEN SENT.
UPDATE ISSUED AT 926 AM CDT SAT JUN 21 2014
CURRENT SURFACE ANALYSIS PLACES FRONTAL BOUNDARY PUSHING THROUGH
ERN MT WHILE MOISTURE CONTINUES TO SLOWLY ADVECT TOWARDS S CTRL
ND. UPPER LEVEL ANALYSIS CONTINUES TO SHOW W/SWRLY FLOW WITH A
VARIETY OF WEAK WAVES MOVING THROUGH. MAIN CONCERN FOR MORNING
FORECAST IS SEVERE THREAT MAINLY OVER S CTRL INTO SERN ND. MORNING
GUIDANCE CONTINUES TO SHOW THE STRONGEST INSTABILITY MAINLY
SOUTH/EAST OF THE CWA...THOUGH STRONG ENOUGH INTO OUR AREA TO
BRING SEVERE CONCERNS. SHEAR INCREASES THROUGH THE AFTERNOON
(~40KTS 0-6KM BULK) AND WILL BE AMPLE FOR SUPERCELL DEVELOPMENT BY
AFTERNOON. LATEST GUIDANCE SUGGESTS MOST STORMS SHOULD FORM MAINLY
IN THE JAMES RIVER VALLEY REGION...THOUGH SOME CONCERN STILL EXITS
A BIT TOWARDS THE WEST. MORNING UPDATE WILL ADDRESS SEVERE
CONCERNS LATER TODAY AND HAVE ADJUSTED POPS WITH MORNING GUIDANCE.
UPDATES WILL BE OUT SHORTLY.
UPDATE ISSUED AT 626 AM CDT SAT JUN 21 2014
WEAK CONVECTION ONGOING ACROSS THE SOUTHWEST. DECIDED TO REMOVE
THUNDER FROM FORECAST FOR THE MORNING. OTHERWISE THIS BATCH OF
SHOWERS WILL TRACK THROUGH SOUTH CENTRAL NORTH DAKOTA. LATE THIS
AFTERNOON STRONGER STORMS WILL FORM ACROSS SOUTH CENTRAL NORTH
DAKOTA AS THE COLD FRONT PROGRESSES EAST.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 327 AM CDT SAT JUN 21 2014
LATEST SEVERAL HRRR RUNS HAVE INSISTED THAT SHOWER ACTIVITY OVER
FAR EASTERN MONTANA WILL HOLD TOGETHER...EVEN EXPANDING AND
STRENGTHENING...WILL SLIDE EASTWARD THIS MORNING AND THEN
DISSIPATE OVER SOUTHEASTERN NORTH DAKOTA. IT SEEMS REASONABLE
BASED ON THE PAST FEW HOURS OF SATELLITE AND RADAR INTERROGATION.
THE MORE PRESSING CONCERN IS FOR POSSIBLE SEVERE THUNDERSTORMS
THIS AFTERNOON AND EVENING SOUTH OF INTERSTATE 94. SPC SLID THEIR
CONVECTIVE OUTLOOK SLIGHT RISK TO THE NORTH THIS MORNING. ML CAPE
IS EXPECTED TO BE IN THE 1500 J/KG BALLPARK...AND SHEAR WILL BE
SUPPORTIVE OF SUPERCELLS.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 327 AM CDT SAT JUN 21 2014
THE EXTENDED PERIOD WILL BE MODERATELY ACTIVE FOR THIS TIME OF THE
YEAR WITH TWO FEATURES BRINGING PRECIPITATION TO THE REGION. FIRST
THE REMNANTS OF THE UPPER LOW ACROSS SASK/MANT WILL SWING SOUTH
THROUGH THE NORTHERN PLAINS MONDAY AND TUESDAY BRINGING SCATTERED
SHOWERS/THUNDERSTORMS TO THE REGION. SUFFICIENT INSTABILITY EXISTS
FOR ROUTINE THUNDERSTORMS WITH NOTHING SCREAMING SEVERE POTENTIAL AT
THIS TIME. A CHANGE TO COOLER WEATHER ALSO IS ANTICIPATED AS THIS
LOW WILL BRING COOLER H850 TEMPS WITH IT. FOLLOWING THIS THE
ECMWF/GFS BOTH ARE BRINGING EASTERN PACIFIC SHORTWAVE ENERGY INTO
WESTERN NORTH AMERICA AND ARE CARVING OUT A LONGWAVE TROUGH ACROSS
THE WESTERN US. THE EUROPEAN SEEMS TO BE MORE AGGRESSIVE WITH A
FASTER AND DEEPER TROUGH. EITHER WAY THE RESULT WILL BE A SOUTHWEST
FLOW ALOFT...WITH AN OPENING TO GULF MOISTURE AND EVENTUALLY A MORE
ACTIVE THUNDERSTORM PATTERN FOR THE LAST WEEK OF JUNE. USING
ALLBLEND GUIDANCE RESULTS IN A CHANCE OF THUNDERSTORMS WEDNESDAY
TROUGH FRIDAY WITH NORMAL TO ABOVE NORMAL TEMPERATURES RETURNING BY
THE END OF THE WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 626 AM CDT SAT JUN 21 2014
AN AREA OF SHOWERS SHOULD MOVE EASTWARD FROM KDIK TO KBIS AND
KJMS. ANOTHER ROUND OF STRONGER THUNDERSTORMS SHOULD FORM AROUND
21Z NEAR KBIS/KJMS. KISN/KMOT SHOULD REMAIN DRY AND VFR.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM 4 PM CDT THIS AFTERNOON THROUGH LATE
TONIGHT FOR NDZ023-025-036-037-046>048-050-051.
&&
$$
UPDATE...JJS
SHORT TERM...SCHECK
LONG TERM...WAA
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
214 PM MDT SAT JUN 21 2014
.SHORT TERM...THIS EVENING THROUGH SUNDAY NIGHT
ISSUED AT 210 PM MDT SAT JUN 21 2014
A BROAD NORTH/SOUTH PRE-FRONTAL SURFACE TROUGH ACROSS
THE WESTERN AND CENTRAL DAKOTAS DOMINATES THE SURFACE MAP THIS
AFTERNOON. THE TROUGH EXTENDS SOUTHWARD FROM A NEARLY STATIONARY LOW
OVER SOUTH CENTRAL CANADA. A WEAK COLD FRONT ALSO EXTENDS SOUTHWARD
FROM THIS LOW THROUGH EASTERN MONTANA AND NORTH CENTRAL WYOMING.
DEWPOINT TEMPERATURES AHEAD OF THE TROUGH IN CENTRAL AND EASTERN
SOUTH DAKOTA ARE IN THE MID 60S...WHILE DEWPOINTS BEHIND THE COLD
FRONT DROP INTO THE MID 40S. ONLY VERY WEAK UPPER LEVEL IMPULSES
ARE DISCERNABLE IN THE MOSTLY ZONAL FLOW ACROSS THE NORTHERN PLAINS
TODAY. SOME WEAK CONVECTION HAS FIRED UP ALONG THE COLD FRONT IN
NORTHEAST WYOMING AND EASTERN MONTANA BUT IR IMAGERY INDICATES
MINIMAL VERTICAL DEVELOPMENT. A WEAKER SURFACE LOW RESIDES OVER
EASTERN COLORADO...SUPORTING A MOSTLY STATIONARY EAST-WEST WARM
FRONT BOUNDARY ALONG THE NEBRASKA SOUTH DAKOTA BORDER. LITTLE OR NO
CONVECTIVE DEVELOPMENT HAS TAKEN PLACE ALONG THIS BOUNDARY. MORNING
SOUNDINGS AT BOTH UNR AND LBF INDICATE A STRONG CAP BELOW 700 MB
WITH A DRY LAYER JUST OFF THE SURFACE AND THEN UNSTABLE LAPS RATES
AT MID LEVELS. TRIGGER TEMPERATURES AT BOTH LOCATIONS ARE IN THE MID
80S.
THIS EVENING...THE KEY FOR LOCATING THE CONVECTIVE DEVELOPMENT THIS
EVENING WILL BE THE LOCATION OF THE VERY DIFFUSE BOUNDAY COINCIDING
WITH THE WESTERN DAKOTAS TROUGH. THE HRRR GUIDANCE MAINTAINS A LINE
OF THUNDERSTORMS FROM THE SOUTHWEST CORNER OF SOUTH DAKOTA TO
CENTRAL SOUTH DAKOTA AS WELL AS AN AREA OF POST FRONTAL STORMS OVER
NORTHEAST WYOMING. THE COMBINATION OF MID LEVEL INSTABILITY...LARGE
CAPE VALUES OVER 2000 J/KG AND ADEQUATE BULK SHEAR OF 30 TO 40 KTS
WILL SUPPORT SUPERCELL DEVELOPMENT CAPABLE OF PRODUCING STRONG WINDS
GUSTS AND LARGE HAIL. IT APPEARS AT THIS TIME THAT MOST OF THE
ACTION THIS AFTERNOON WILL TAKE PLACE EAST AND SOUTH OF THE BLKHLS
REGION WITH SOMEWHAT WEAKER ACTIVITY OVER NORTHEAST WYOMING.
OVERNIGHT TONIGHT...THE SURFACE FRONT WILL SLOWLY SHIFT SOUTH AND
EAST DURING THE LATE EVENING. STRONG TO SEVERE STORMS ARE LIKELY
ALONG OR NEAR THE FRONTAL BOUNDARY AS IT CONTINUES EASTWARD INTO
CENTRAL SOUTH DAKOTA BY 04Z. A WEAK UPPER LEVEL IMPULSE IS EXPECTED
TO MOVE INTO NORTHEAST WYOMING AND AND A BROAD AREA OF ISENTROPIC
UPGLIDE IS FORECAST TO DEVELOP OVER THE SHALLOW COOL AIR IN WESTERN
SOUTH DAKOTA AND NORTHEAST WYOMING MOSTLY SOUTH OF US HWY 212
RESULTING IN A STRATIFORM PRECIP EVENT FOR AREAS STRETCHING FROM
AROUND THE BLKLHS TO THE MORVR. TEMPERATURES WILL COOL INTO THE 50S
TO LOWER 60S.
SUNDAY...OVERCAST SKIES AND STRATIFORM PRECIP SHOULD BE ONGOING
BEFORE SUN RISE IN NORTHEAST WYOMING AND THE BLKHLS AREA AND SPREAD
TO THE MORVR BEFORE NOON. ISOLATED THUNDERSTORMS ARE POSSIBLE...BUT
THESE SHOULD BE PRETTY WEAK. A MODERATE NORTHWEST BREEZE WILL
ACCOMPANY THE LIGHT RAIN. THE LIGHT RAIN IS EXPECTED TO BEGIN
TAPPERING OFF BY 00Z AS THE COOL AIRMASS PUSHES FURTHER SOUTH AND
EAST. COOLER AIR WILL MOVE INTO THE NORTHERN PLAINS...WITH HIGH
TEMPERATURES 10 TO 15 DEGRESS COOLER THAN TODAY...ONLY IN THE MID
60S TO UPPER 70S.
SUNDAY NIGHT...DISSIPATING PRECIPITATION AND SOME LINGERING CLOUD
COVER WILL KEEP TEMPERATURES FROM DROPPING BELOW THE LOWER 50S IN
MOST PLACES...UPPER 40S IN NORTHEAST WYOMING AND THE BLKHLS.
&&
.LONG TERM...MONDAY THROUGH SATURDAY
ISSUED AT 210 PM MDT SAT JUN 21 2014
AN UPPER LEVEL RIDGE OVER THE NORTHERN ROCKIES WILL SLOWLY EXPAND
EASTWARD MONDAY THROUGH THURSDAY. BY THURSDAY...AN UPPER LEVEL
TROUGH WILL HAVE DEVELOPED OVER SOUTHWEST CANADA/NORTHWEST US. THE
RESULT WILL BE WEST/NORTHWEST FLOW ALOFT EARLY IN THE PERIOD
TRANSITIONING TO SOUTHWEST FLOW ALOFT BY THE END OF THE WEEK. A
PARADE OF SHORTWAVES WILL BRING TSRA AT TIMES...ESPECIALLY DURING
THE AFTERNOON/EVENING HOURS GIVEN SLOWLY BUILDING THERMAL RIDGE OVER
THE NORTHERN PLAINS AND SUBSEQUENT SLIGHTLY HIGHER MLCIN VALUES.
GFS/ECMWF ARE IN GENERAL AGREEMENT...BUT BOTH HINT AT POSSIBLE BACK
DOOR COOL FRONTS TUESDAY OR WEDNESDAY FOR THE SD PLAINS GIVEN
PROXIMITY OF UPPER LOW OVER HUDSON BAY. DIDN/T DEVIATE MUCH FROM
GUIDANCE VALUES FOR TEMPERATURES.
&&
.AVIATION...FOR THE 18Z TAFS THROUGH 18Z SUNDAY
ISSUED AT 210 PM MDT SAT JUN 21 2014
SCATTERED TSRA WILL CONTINUE TO DEVELOP ON THE SD PLAINS AND SPREAD
EAST THROUGH THIS EVENING. ISOLATED TSRA ARE POSSIBLE OVER NORTHEAST
WY INTO THE BLACK HILLS THROUGH EARLY THIS EVENING. HAIL/GUSTY WINDS
ARE POSSIBLE WITH ANY STORMS INCLUDING LOCAL IFR VSBYS/CIGS...
PARTICULARLY FROM SOUTHWEST THROUGH SOUTH CENTRAL SD. ANOTHER WAVE
OF SHRA/TSRA WILL DEVELOP LATER TONIGHT INTO SUNDAY MORNING
RESULTING IN RATHER WIDESPREAD PRECIPITATION COVERAGE ACROSS
NORTHEAST WY/WESTERN SD...WITH AREAS MVFR CIGS/VSBYS IN THE
STRONGEST ECHOES.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...CARPENTER
LONG TERM...HELGESON
AVIATION...HELGESON
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1057 AM MDT SAT JUN 21 2014
.UPDATE...
ISSUED AT 1027 AM MDT SAT JUN 21 2014
A BROAD NORTH/SOUTH PRE-FRONTAL SURFACE TROUGH ACROSS THE WESTERN
DAKOTAS DOMINATES THE SURFACE MAP. THE TROUGH EXTENDS SOUTHWARD
FROM A NEARLY STATIONARY LOW OVER SOUTH CENTRAL CANADA. A WEAK
COLD FRONT ALSO EXTENDS SOUTHWARD FROM THIS LOW THROUGH EASTERN
MONTANA AND NORTH CENTRAL WYOMING. DEWPOINT TEMPERATURES AHEAD OF
THE TROUGH IN CENTRAL AND EASTERN SOUTH DAKOTA ARE IN THE MID
60S...WHILE DEWPOINTS BEHIND THE COLD FRONT DROP INTO THE MID 40S.
ONLY VERY WEAK UPPER LEVEL IMPULSES ARE DISCERNIBLE IN THE MOSTLY
ZONAL FLOW ACROSS THE NORTHERN PLAINS TODAY. SOME WEAK CONVECTION
HAS FIRED UP ALONG THE COLD FRONT IN NORTHEAST WYOMING AND EASTERN
MONTANA BUT IR IMAGERY INDICATES NO SIGNIFICANT VERTICAL
DEVELOPMENT. A WEAKER SURFACE LOW RESIDES OVER EASTERN
COLORADO...SUPPORTING A MOSTLY STATIONARY EAST-WEST WARM FRONT
BOUNDARY ALONG THE NEBRASKA SOUTH DAKOTA BORDER. LITTLE OR NO
CONVECTIVE DEVELOPMENT HAS TAKEN PLACE ALONG THIS BOUNDARY.
MORNING SOUNDINGS AT BOTH UNR AND LBF INDICATE A STRONG CAP BELOW
700 MB WITH A DRY LAYER JUST OFF THE SURFACE AND THEN UNSTABLE
LAPS RATES AT MID LEVELS. TRIGGER TEMPERATURES AT BOTH LOCATIONS
ARE IN THE MID 80S.
TODAY...THE KEY FOR LOCATING THE CONVECTIVE DEVELOPMENT THIS
AFTERNOON WILL BE THE LOCATION OF THE VERY DIFFUSE BOUNDARY
COINCIDING WITH THE WESTERN DAKOTAS TROUGH AT THE TIME THE TRIGGER
TEMPERATURES ARE MET. THE HRRR SEEMS TO BE SHOWING A PRETTY GOOD
SOLUTION FOR THIS...DEVELOPING A LINE OF THUNDERSTORMS FROM THE
SOUTHWEST CORNER OF SOUTH DAKOTA TO CENTRAL SOUTH DAKOTA BETWEEN 20Z
AND 21Z. AS MENTIONED IN PREVIOUS DISCUSSIONS...THE COMBINATION OF
MID LEVEL INSTABILITY...LARGE CAPE VALUES OVER 2000 J/KG AND
ADEQUATE BULK SHEAR OF 30 TO 40 KTS WILL SUPPORT DISCREET SUPERCELL
DEVELOPMENT CAPABLE OF PRODUCING STRONG WINDS GUSTS AND LARGE HAIL.
IT APPEARS AT THIS TIME THAT MOST OF THE ACTION THIS AFTERNOON WILL
TAKE PLACE EAST AND SOUTH OF THE BLKHLS REGION.
&&
.SHORT TERM...TODAY THROUGH SUNDAY NIGHT
ISSUED AT 256 AM MDT SAT JUN 21 2014
UPPER LEVEL ANALYSIS HAS CLOSED LOW OVER SOUTH CENTRAL CANADA WITH
NEAR ZONAL FLOW ACROSS THE NORTHERN PLAINS. SKIES ARE MOSTLY CLEAR
ACROSS THE AREA AT THE MOMENT. AT THE SURFACE...DIFFUSE TROF OF
LOW PRESSURE STRETCHES NORTH/SOUTH ACROSS THE WESTERN DAKOTAS WITH
WEAK LOW CENTERS LOCATED IN SOUTH CENTRAL CANADA AND SOUTHEASTERN
COLORADO. WARM FRONTAL BOUNDARY EXTENDS FROM THE COLORADO LOW INTO
FAR SOUTH CENTRAL SOUTH DAKOTA. TEMPERATURES AT 3 AM ARE GENERALLY
IN THE MID 50S TO MID 60S. WINDS ARE LIGHT.
TODAY...UPPER LOW CONTINUES TO CHURN ACROSS SOUTH CENTRAL CANADA
AS UPPER FLOW REMAINS NEARLY ZONAL ACROSS THE NORTHERN PLAINS.
WEAK MID LEVEL ENERGY IN THIS FLOW CONTINUES TO MOVE WEST TO EAST
ACROSS THE AREA. AT THE SURFACE...WEAK FRONTAL BOUNDARY ACROSS
SOUTH CENTRAL SOUTH DAKOTA WILL SHIFT INTO WESTERN SOUTH DAKOTA BY
MID DAY WITH SOUTHEASTERLY WINDS TRANSPORTING ADDITIONAL MOISTURE
INTO THE WESTERN SOUTH DAKOTA PLAINS. VERY WARM SURFACE TEMPS...IN
THE MID 70S TO UPPER 80S...COMBINED WITH INCREASING MOISTURE WILL
PRODUCE VERY UNSTABLE CONDITIONS ACROSS THE SOUTH DAKOTA PLAINS
EARLY THIS AFTERNOON. CAPE VALUES QUICKLY EXCEED 2000 J/KG...AND
WITH DECENT SHEAR AND SURFACE FRONTAL BOUNDARY IN PLAY...STRONG TO
SEVERE THUNDERSTORMS ARE LIKELY TO FORM FROM THE BLACK HILLS EAST.
THE MAIN THREAT FROM ANY STORM WILL BE LARGE HAIL AND DAMAGING
WIND GUSTS.
TONIGHT...SURFACE FRONT WILL SLOWLY SHIFT SOUTH AND EAST DURING
THE EVENING...WITH STRONG TO SEVERE STORMS CONTINUING. THE
STRONGEST STORMS SHOULD PUSH EAST DURING THE EVENING WITH THE
FRONTAL BOUNDARY. ADDITIONAL SHORTWAVE ENERGY WILL MOVE INTO
WESTERN PARTS OF THE AREA OVERNIGHT. EXPECT SHOWERS AND STORMS TO
CONTINUE ACROSS MUCH OF THE AREA THROUGH EARLY SUNDAY MORNING.
TEMPERATURES WILL COOL INTO THE 50S TO LOWER 60S.
SUNDAY...ZONAL FLOW CONTINUES WITH WEAK SHORTWAVE ENERGY CROSSING
THE NORTHERN PLAINS. MOSTLY CLOUDY SKIES ARE EXPECTED WITH SHOWERS
AND THUNDERSTORMS CONTINUING ACROSS THE AREA ON SUNDAY...WITH BEST
CHANCES ACROSS NORTHEAST WYOMING AND SOUTHERN SOUTH DAKOTA. COOLER
AIR WILL MOVE INTO THE NORTHERN PLAINS...WITH HIGH TEMPERATURES
ONLY IN THE MID 60S TO UPPER 70S EXPECTED.
&&
.LONG TERM...MONDAY THROUGH FRIDAY
ISSUED AT 256 AM MDT SAT JUN 21 2014
UPPER LEVEL LOW PRESSURE OVER MANITOBA ON MONDAY WILL SLOWLY DROP
INTO NORTHERN MINNESOTA BY MID WEEK...BEFORE PUSHING EAST BY THE END
OF THE EXTENDED PERIOD. AT THE SAME TIME...AN UPPER LEVEL RIDGE WILL
BUILD OVER THE NORTHERN ROCKIES AND SLOWLY SHIFT EASTWARD INTO THE
NORTHERN PLAINS NEXT WEEK. THERMAL RIDGE INCREASES THROUGH THE
WEEK...WITH MUCH WARMER/SUMMERLIKE TEMPERATURES TOWARD THE END OF
THE WORK WEEK. HOWEVER...ANOTHER UPPER TROF PUSHES THROUGH THE
ROCKIES LATE IN THE PERIOD...WHICH WILL ONCE AGAIN COOL TEMPERATURES
DOWN TO BELOW SEASONAL AVERAGES FOR NEXT WEEKEND.
DAILY CHANCES FOR SHOWERS AND THUNDERSTORMS ARE EXPECTED AS A SERIES
OF SHORTWAVES PASS THROUGH THE FLOW. COVERAGE BY MID WEEK SHOULD BE
KEPT TO A MINIMUM AS HIGHER MID-LEVEL TEMPERATURES TEND TO KEEP
MLCIN VALUES UP DURING PEAK HEATING. HOWEVER WITH THE UPPER TROF
PROGGED TO PUSH TOWARD THE AREA BY LATE IN THE PERIOD...CHANCES WILL
INCREASE AGAIN TOWARD NEXT WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY)
ISSUED AT 1050 AM MDT SAT JUN 21 2014
VFR CONDITIONS ARE EXPECTED THROUGH EARLY THIS AFTERNOON.
SCATTERED TSRA WILL THEN DEVELOP ON THE SD PLAINS AND SPREAD EAST
THROUGH THIS EVENING. ISOLATED TSRA ARE POSSIBLE OVER NORTHEAST WY
INTO THE BLACK HILLS THROUGH EARLY THIS EVENING. HAIL/GUSTY WINDS
ARE POSSIBLE WITH ANY STORMS INCLUDING LOCAL IFR VSBYS/CIGS...PARTICULARLY
FROM SOUTHWEST THROUGH SOUTH CENTRAL SD. ANOTHER WAVE OF SHRA/TSRA
WILL DEVELOP LATER TONIGHT INTO SUNDAY MORNING RESULTING IN RATHER
WIDESPREAD COVERAGE ACROSS NORTHEAST WY/WESTERN SD...AND AREAS
MVFR CIGS/VSBYS IN THE STRONGEST ECHOES.
&&
.HYDROLOGY...
ISSUED AT 256 AM MDT SAT JUN 21 2014
FLOODING HAS SUBSIDED ACROSS THE FORECAST AREA. RIVERS AND STREAMS
REMAIN HIGH...BUT HAVE RECEDED SIGNIFICANTLY OVER THE PAST FEW DAYS.
THUS...ALL FLOOD WARNINGS HAVE BEEN CANCELLED OR WERE ALLOWED TO
EXPIRE.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
UPDATE...CARPENTER
SHORT TERM...15
LONG TERM...MLS
AVIATION...HELGESON
HYDROLOGY...MLS
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1029 AM MDT SAT JUN 21 2014
.UPDATE...
ISSUED AT 1027 AM MDT SAT JUN 21 2014
A BROAD NORTH/SOUTH PRE-FRONTAL SURFACE TROUGH ACROSS
THE WESTERN DAKOTAS DOMINATES THE SURFACE MAP. THE TROUGH EXTENDS
SOUTHWARD FROM A NEARLY STATIONARY LOW OVER SOUTH CENTRAL CANADA. A
WEAK COLD FRONT ALSO EXTENDS SOUTHWARD FROM THIS LOW THROUGH EASTERN
MONTANA AND NORTH CENTRAL WYOMING. DEWPOINT TEMPERATURES AHEAD OF
THE TROUGH IN CENTRAL AND EASTERN SOUTH DAKOTA ARE IN THE MID
60S...WHILE DEWPOINTS BEHIND THE COLD FRONT DROP INTO THE MID 40S.
ONLY VERY WEAK UPPER LEVEL IMPULSES ARE DISCERNABLE IN THE MOSTLY
ZONAL FLOW ACROSS THE NORTHERN PLAINS TODAY. SOME WEAK CONVECTION
HAS FIRED UP ALONG THE COLD FRONT IN NORTHEAST WYOMING AND EASTERN
MONTANA BUT IR IMAGERY INDICATES NO SIGNIFICANT VERTICAL
DEVELOPMENT. A WEAKER SURFACE LOW RESIDES OVER EASTERN
COLORADO...SUPORTING A MOSTLY STATIONARY EAST-WEST WARM FRONT
BOUNDARY ALONG THE NEBRASKA SOUTH DAKOTA BORDER. LITTLE OR NO
CONVECTIVE DEVELOPMENT HAS TAKEN PLACE ALONG THIS BOUNDARY. MORNING
SOUNDINGS AT BOTH UNR AND LBF INDICATE A STRONG CAP BELOW 700 MB
WITH A DRY LAYER JUST OFF THE SURFACE AND THEN UNSTABLE LAPS RATES
AT MID LEVELS. TRIGGER TEMPERATURES AT BOTH LOCATIONS ARE IN THE MID
80S.
TODAY...THE KEY FOR LOCATING THE CONVECTIVE DEVELOPMENT THIS
AFTERNOON WILL BE THE LOCATION OF THE VERY DIFFUSE BOUNDAY
COINCIDING WITH THE WESTERN DAKOTAS TROUGH AT THE TIME THE TRIGGER
TEMPERATURES ARE MET. THE HRRR SEEMS TO BE SHOWING A PRETTY GOOD
SOLUTION FOR THIS...DEVELOPING A LINE OF THUNDERSTORMS FROM THE
SOUTHWEST CORNER OF SOUTH DAKOTA TO CENTRAL SOUTH DAKOTA BETWEEN 20Z
AND 21Z. AS MENTIONED IN PREVIOUS DISCUSSIONS...THE COMBINATION OF
MID LEVEL INSTABILITY...LARGE CAPE VALUES OVER 2000 J/KG AND
ADEQUATE BULK SHEAR OF 30 TO 40 KTS WILL SUPPORT DISCREET SUPERCELL
DEVELOPMENT CAPABLE OF PRODUCING STRONG WINDS GUSTS AND LARGE HAIL.
IT APPEARS AT THIS TIME THAT MOST OF THE ACTION THIS AFTERNOON WILL
TAKE PLACE EAST AND SOUTH OF THE BLKHLS REGION.
&&
.SHORT TERM...TODAY THROUGH SUNDAY NIGHT
ISSUED AT 256 AM MDT SAT JUN 21 2014
UPPER LEVEL ANALYSIS HAS CLOSED LOW OVER SOUTH CENTRAL CANADA WITH
NEAR ZONAL FLOW ACROSS THE NORTHERN PLAINS. SKIES ARE MOSTLY CLEAR
ACROSS THE AREA AT THE MOMENT. AT THE SURFACE...DIFFUSE TROF OF
LOW PRESSURE STRETCHES NORTH/SOUTH ACROSS THE WESTERN DAKOTAS WITH
WEAK LOW CENTERS LOCATED IN SOUTH CENTRAL CANADA AND SOUTHEASTERN
COLORADO. WARM FRONTAL BOUNDARY EXTENDS FROM THE COLORADO LOW INTO
FAR SOUTH CENTRAL SOUTH DAKOTA. TEMPERATURES AT 3 AM ARE GENERALLY
IN THE MID 50S TO MID 60S. WINDS ARE LIGHT.
TODAY...UPPER LOW CONTINUES TO CHURN ACROSS SOUTH CENTRAL CANADA
AS UPPER FLOW REMAINS NEARLY ZONAL ACROSS THE NORTHERN PLAINS.
WEAK MID LEVEL ENERGY IN THIS FLOW CONTINUES TO MOVE WEST TO EAST
ACROSS THE AREA. AT THE SURFACE...WEAK FRONTAL BOUNDARY ACROSS
SOUTH CENTRAL SOUTH DAKOTA WILL SHIFT INTO WESTERN SOUTH DAKOTA BY
MID DAY WITH SOUTHEASTERLY WINDS TRANSPORTING ADDITIONAL MOISTURE
INTO THE WESTERN SOUTH DAKOTA PLAINS. VERY WARM SURFACE TEMPS...IN
THE MID 70S TO UPPER 80S...COMBINED WITH INCREASING MOISTURE WILL
PRODUCE VERY UNSTABLE CONDITIONS ACROSS THE SOUTH DAKOTA PLAINS
EARLY THIS AFTERNOON. CAPE VALUES QUICKLY EXCEED 2000 J/KG...AND
WITH DECENT SHEAR AND SURFACE FRONTAL BOUNDARY IN PLAY...STRONG TO
SEVERE THUNDERSTORMS ARE LIKELY TO FORM FROM THE BLACK HILLS EAST.
THE MAIN THREAT FROM ANY STORM WILL BE LARGE HAIL AND DAMAGING
WIND GUSTS.
TONIGHT...SURFACE FRONT WILL SLOWLY SHIFT SOUTH AND EAST DURING
THE EVENING...WITH STRONG TO SEVERE STORMS CONTINUING. THE
STRONGEST STORMS SHOULD PUSH EAST DURING THE EVENING WITH THE
FRONTAL BOUNDARY. ADDITIONAL SHORTWAVE ENERGY WILL MOVE INTO
WESTERN PARTS OF THE AREA OVERNIGHT. EXPECT SHOWERS AND STORMS TO
CONTINUE ACROSS MUCH OF THE AREA THROUGH EARLY SUNDAY MORNING.
TEMPERATURES WILL COOL INTO THE 50S TO LOWER 60S.
SUNDAY...ZONAL FLOW CONTINUES WITH WEAK SHORTWAVE ENERGY CROSSING
THE NORTHERN PLAINS. MOSTLY CLOUDY SKIES ARE EXPECTED WITH SHOWERS
AND THUNDERSTORMS CONTINUING ACROSS THE AREA ON SUNDAY...WITH BEST
CHANCES ACROSS NORTHEAST WYOMING AND SOUTHERN SOUTH DAKOTA. COOLER
AIR WILL MOVE INTO THE NORTHERN PLAINS...WITH HIGH TEMPERATURES
ONLY IN THE MID 60S TO UPPER 70S EXPECTED.
&&
.LONG TERM...MONDAY THROUGH FRIDAY
ISSUED AT 256 AM MDT SAT JUN 21 2014
UPPER LEVEL LOW PRESSURE OVER MANITOBA ON MONDAY WILL SLOWLY DROP
INTO NORTHERN MINNESOTA BY MID WEEK...BEFORE PUSHING EAST BY THE END
OF THE EXTENDED PERIOD. AT THE SAME TIME...AN UPPER LEVEL RIDGE WILL
BUILD OVER THE NORTHERN ROCKIES AND SLOWLY SHIFT EASTWARD INTO THE
NORTHERN PLAINS NEXT WEEK. THERMAL RIDGE INCREASES THROUGH THE
WEEK...WITH MUCH WARMER/SUMMERLIKE TEMPERATURES TOWARD THE END OF
THE WORK WEEK. HOWEVER...ANOTHER UPPER TROF PUSHES THROUGH THE
ROCKIES LATE IN THE PERIOD...WHICH WILL ONCE AGAIN COOL TEMPERATURES
DOWN TO BELOW SEASONAL AVERAGES FOR NEXT WEEKEND.
DAILY CHANCES FOR SHOWERS AND THUNDERSTORMS ARE EXPECTED AS A SERIES
OF SHORTWAVES PASS THROUGH THE FLOW. COVERAGE BY MID WEEK SHOULD BE
KEPT TO A MINIMUM AS HIGHER MID-LEVEL TEMPERATURES TEND TO KEEP
MLCIN VALUES UP DURING PEAK HEATING. HOWEVER WITH THE UPPER TROF
PROGGED TO PUSH TOWARD THE AREA BY LATE IN THE PERIOD...CHANCES WILL
INCREASE AGAIN TOWARD NEXT WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY)
ISSUED AT 1027 AM MDT SAT JUN 21 2014
VFR CONDITIONS THROUGH THIS MORNING. EXPECT SHOWERS AND
THUNDERSTORMS TO DEVELOP THIS AFTERNOON AND CONTINUE OVERNIGHT.
STRONGER STORMS WILL HAVE GUSTY WINDS...HAIL...AND LOCAL IFR
CIGS/VSBYS.
&&
.HYDROLOGY...
ISSUED AT 256 AM MDT SAT JUN 21 2014
FLOODING HAS SUBSIDED ACROSS THE FORECAST AREA. RIVERS AND STREAMS
REMAIN HIGH...BUT HAVE RECEDED SIGNIFICANTLY OVER THE PAST FEW DAYS.
THUS...ALL FLOOD WARNINGS HAVE BEEN CANCELLED OR WERE ALLOWED TO
EXPIRE.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
UPDATE...CARPENTER
SHORT TERM...15
LONG TERM...MLS
AVIATION...MLS
HYDROLOGY...MLS
AREA FORECAST DISCUSSION
NWS MIDLAND/ODESSA TX
212 PM CDT Sat Jun 21 2014
.DISCUSSION...
A well defined Mexican moisture tap is still evident on water vapor
imagery with embedded shrtwv trof/s, one of which is lifting out
the area while another model depicted shrtwv trof follows and in
part is responsible for renewed SHRA/TSRA. The area where SHRA/TSRA
have been occurring is area co-located where 9h-85h mstr flux has
persisted and PWs are near 1.75" per GEFS (about 2.5 standard
deviations above normal). The RUC13 show this area of moisture
flux redeveloping to the n into the n-ne PB and thus we would not
be surprised to SHRA/TSRA develop into the n-ne these next few
hrs. Heavy rain is main concern and local flooding/flash flooding
is possible.
Mid level ridge will slowly builds in from the w and serve to
push the general mid level trof/moisture axis that has been over
the area to the e resulting in a decreased chance of rain and an
increase in temperatures. Still there are some opportunities for
precip. For Sunday PoPs will generally be confined to the mtns
where very steep LR/s of 8-9 c/km are to be coincident with sfc
dwpnts in the m40-50 along e slopes, flow will be upslope, and
CINH will be a non-issue in/near elevated heat sources. Meanwhile
Sunday night storms may near the far NW CWFA with shrtwv trof in
NW flow aloft. On Monday NAM12/ECMWF better depicts a shrtwv trof
in the NW flow and develops storms by mid/late afternoon in E-SE
NM and then in PB after 21Z. Development may be enhanced by a
boundary from previous convection and/or its own cold pool. Timing
will be important, if it does come thru early then there won`t be
much concern for precip into the evening. Tue models hint at tstms
from the mtns into E-SE NM where moist se low level flow and
secondary mid level theta-e ridge are expected to be. ECMWF wants
light up the mtns again Thur/Fri, while the GFS confines precip
moreso to the Davis mtns. As frequently is the case for the mtns
the development is tied to the mid level theta-e ridge axis and
based on consensus of data the Davis mtns are favored over the GDP
mtns. A mid level trof is progged to push in to the n Friday,
which may advect drier air ewd. Through the extended part of the
fcst the GFS is much warmer than ECMWF in part due to its more
veered/stronger wly winds which aids thermal ridge/dry air.
Climatology certainly favors the GFS and with warm temperatures
already in forecast with probably use a blender approach to catch
general trends.
&&
.PRELIMINARY POINT TEMPS/POPS...
ANDREWS TX 68 96 69 95 / 10 10 10 30
BIG SPRING TX 69 93 72 93 / 20 10 10 20
CARLSBAD NM 67 101 72 101 / 10 20 20 10
DRYDEN TX 75 97 74 102 / 20 10 10 10
FORT STOCKTON TX 71 96 72 99 / 10 10 10 10
GUADALUPE PASS TX 70 99 70 96 / 10 20 20 10
HOBBS NM 66 95 67 92 / 10 10 10 30
MARFA TX 59 95 60 96 / 20 10 10 10
MIDLAND INTL AIRPORT TX 71 95 72 94 / 10 10 10 20
ODESSA TX 70 94 70 94 / 10 10 10 20
WINK TX 71 100 73 100 / 10 10 10 20
&&
.MAF WATCHES/WARNINGS/ADVISORIES...
NM...NONE.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
347 PM CDT SAT JUN 21 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 345 PM CDT SAT JUN 21 2014
AT 3 PM...A MESOSCALE CONVECTIVE VORTICITY...GENERATED FROM THE
THUNDERSTORMS IN NEBRASKA AND SOUTH DAKOTA LAST EVENING...WAS
MOVING EAST THROUGH SOUTHERN WISCONSIN. THIS SYSTEM IS GENERATING
SHOWERS AND A FEW THUNDERSTORMS IN AN AREA OF 2500 J/KG SURFACE
CAPES. BOTH THE 21.12Z ARW AND LATEST HRRR ARE IN GOOD AGREEMENT
THAT A FEW SHOWERS WILL LINGER ACROSS ADAMS AND JUNEAU COUNTIES IN
CENTRAL WISCONSIN THROUGH 22.03Z...AND THEN THE REMAINDER OF
TONIGHT WILL BE DRY AS SUBSIDENCE BUILDS ACROSS THE AREA IN THE
WAKE OF THE CONVECTIVELY INDUCED VORT MAX AND SHORT WAVE RIDGE.
ON SUNDAY...THE 21.12Z MODELS ARE IN GOOD AGREEMENT THAT SCATTERED
SHOWERS AND THUNDERSTORMS WILL DEVELOP DURING THE MORNING ACROSS
SOUTHEAST MINNESOTA AND NORTHEAST IOWA AHEAD OF AN APPROACHING
COLD FRONT AND SHORT WAVE TROUGH MOVING OUT OF THE CENTRAL PLAINS.
THESE SHOWERS AND THUNDERSTORMS THEN BECOME MORE WIDESPREAD ACROSS
THE ENTIRE FORECAST AREA AS THE UPPER LEVEL DIVERGENCE INCREASES...
THE AREA ENTERS THE RIGHT ENTRANCE REGION OF A 50 KNOT 250 MB
JET...AND THE SURFACE BASE CAPES CLIMB INTO THE 3-4K J/KG RANGE.
WHILE THE MODELS ARE IN AGREEMENT WITH THIS...THEY DO DIFFER SOME
ON HOW ORGANIZED THIS CONVECTION BECOMES DURING THE AFTERNOON. THE
ARW SUGGEST A LINE OF STORMS BY EARLY AFTERNOON. MEANWHILE THE
21.12Z SPC WRF SUGGESTS THAT THE CONVECTION WILL BE LESS
ORGANIZED. WHILE THE 0-3 KM AND 0-6 KM SHEAR IS NOT SUFFICIENT FOR
THE DEVELOPMENT OF SUPERCELLS...THE MID LEVEL LAPSE RATES ARE
RUNNING IN THE 7 TO 8 C/KM RANGE WHICH WOULD BE SUFFICIENT FOR THE
DEVELOPMENT OF LARGE HAIL AND DRY AIR BELOW THE CLOUDS MAY AID IN
STRENGTHENING THE DOWN DRAFTS...SO WILL HAVE TO WATCH OUT FOR
PULSE SEVERE STORMS.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 345 PM CDT SAT JUN 21 2014
FROM SUNDAY NIGHT INTO MONDAY...THE CONVECTION BECOMES MORE
ORGANIZED AS THE COLD FRONT AND SURFACE LOW MOVES SLOWLY THROUGH
THE FORECAST AREA. STRONG 850 MB MOISTURE JET WILL RESULT IN THE
DEVELOPMENT OF A MESOSCALE CONVECTIVE COMPLEX. IN ADDITION...
PRECIPITABLE WATER VALUES CLIMB INTO THE 1.7 TO 1.9 INCH RANGE
AND WARM CLOUD DEPTHS CLIMB TO 4 KM AHEAD OF THE SURFACE LOW.
THIS WILL RESULT IN THE THREAT OF HEAVY RAIN AND POTENTIALLY SOME
MORE FLOODING. WITH MODELS DEVIATING ON THE TIMING...LOCATION OF
THE SURFACE LOW...AND STRENGTH OF THE SHORT WAVE TROUGH...HELD OFF
ISSUING A FLOOD WATCH FOR NOW. WHILE THE 0-6 KM SHEAR REMAINS
WEAK...THE 0-3 KM DOES EXCEED 30 KNOTS AND THIS COULD RESULT IN
SOME WIND DAMAGE AS THE SYSTEM EVOLVES.
MONDAY NIGHT IS NOW LOOKING DRY IN ALL OF THE DETERMINISTIC MODELS
AS SUBSIDENCE DEVELOPS IN THE WAKE OF THE DEPARTING LOW PRESSURE
SYSTEM. AS A RESULT...EITHER REDUCED OR TOOK OUT THE
PRECIPITATION CHANCES ACROSS THE ENTIRE FORECAST AREA.
FROM TUESDAY THROUGH THURSDAY....A CANADIAN COLD FRONT DROPS INTO
THE REGION. WHILE THE MODELS HAVE BEEN CONSISTENT AT DOING THIS...
THEY CONTINUE TO STRUGGLE ON HOW FAR SOUTH THIS FRONT WILL GET.
THE MODELS ALSO CONTINUE TO SHOW THAT SEVERAL SHORT WAVE TROUGHS
WILL MOVE ALONG THIS BOUNDARY. HOWEVER THERE IS ONLY WEAK MOISTURE
TRANSPORT INTO THE REGION WHICH RESULTS IN WEAK 0-3 KM AND 0-6 KM
SHEAR...THUS NOT EXPECTING ANY SEVERE WEATHER AT THIS TIME.
FROM THURSDAY NIGHT INTO SATURDAY...A PATTERN SHIFT OCCURS AS A
LONG WAVE TROUGH MOVES INTO THE WESTERN UNITED STATES. WHILE BOTH
THE GFS AND ECMWF ARE IN AGREEMENT THAT AND UPPER LEVEL RIDGE WILL
BUILD AHEAD OF THIS TROUGH...THERE CONTINUES TO BE QUESTIONS ON
HOW FAR WEST THIS RIDGE WILL END UP AND THIS WILL GREATLY AFFECT
WHETHER WE WILL SEE PRECIPITATION OR NOT. DUE TO THIS...JUTS
STAYED WITH THE MODEL CONSENSUS FOR NOW.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1236 PM CDT SAT JUN 21 2014
A BAND OF LIGHT RAIN SHOWERS AND UPPER LEVEL CLOUD COVER WILL
SHIFT TO THE EAST QUICKLY THIS AFTERNOON WITH THE REMNANTS OF AN
OVERNIGHT STORM SYSTEM MOVING INTO CENTRAL WISCONSIN. SKIES WILL
CLEAR OUT WITH WINDS REMAINING LIGHT THROUGH TOMORROW MORNING AS A
WEAK RIDGE OF HIGH PRESSURE MOVES IN. WINDS WILL SHIFT AROUND TO
THE SOUTHEAST TOMORROW MORNING AHEAD OF THE NEXT SYSTEM WHICH MAY
BRING SOME THUNDERSTORMS IN ON SUNDAY AFTERNOON/EVENING.
&&
.HYDROLOGY...
ISSUED AT 345 PM CDT SAT JUN 21 2014
THE MISSISSIPPI TRIBUTARIES HAVE CRESTED AND ARE NOW FALLING.
MEANWHILE THE MISSISSIPPI RIVER IS RISING WITH FLOODING EXPECTED
AT WABASHA...WINONA...AND MCGREGOR. AT THIS TIME...LA CROSSE IS
NOT EXPECTED TO REACH FLOOD STAGE. HOWEVER THIS COULD CHANGE
DEPENDING ON HOW MUCH RAIN FALLS ON SUNDAY NIGHT.
BETWEEN 1 AND 3 INCHES OF RAIN LOOKS POSSIBLE ON SUNDAY
NIGHT...BUT DUE TO MODEL INCONSISTENCIES HELD OFF ISSUING A FLOOD
WATCH FOR NOW.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...HALBACH
HYDROLOGY...BOYNE
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1236 PM CDT SAT JUN 21 2014
.UPDATE...
ISSUED AT 1137 AM CDT SAT JUN 21 2014
REMNANT MCV FROM LAST NIGHTS CONVECTION FURTHER SOUTHWEST IS
CURRENTLY TRACKING EAST ACROSS NORTHEAST IOWA/SOUTHWEST WISCONSIN.
THIS HAS LEAD TO MUCH MORE CLOUD COVER AND SOME LIGHT RAIN SHOWERS
ALONG THE MISSISSIPPI RIVER. 16Z RAP ANALYSIS SHOWS THE BETTER
SB/MLCAPE CHANNEL RUNNING OUT AHEAD OF THIS MCV INTO
SOUTHWEST/WEST CENTRAL WISCONSIN WITH IT BULLSEYED ON THE DELLS.
THE MAIN CONVECTIVE CHANCES WILL BE OVER THE NEXT FEW HOURS BEFORE
THIS FEATURE MOVES OFF TO THE EAST BY MID AFTERNOON. ONCE IT DOES
MOVE OFF TO THE EAST...IT APPEARS THAT WE WILL SEE A DRY PERIOD
GOING THROUGH TONIGHT AS A RIDGE OF HIGH PRESSURE MOVES IN WITH
DRIER/STABLE AIR. THUS...HAVE ADJUSTED TRENDS TO BE
CLOUDIER/RAINIER THIS MORNING/EARLY AFTERNOON AND THEN DROPPED
CHANCES FOR PRECIPITATION FOR LATE THIS AFTERNOON/EARLY EVENING.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 316 AM CDT SAT JUN 21 2014
MAIN FORECAST CONCERN IS WITH THE RAIN CHANCES THROUGH THE PERIOD.
REGIONAL RADARS SHOWING A CONVECTIVE COMPLEX THIS MORNING OVER
SOUTHWEST IOWA INTO SOUTHERN NEBRASKA. MOVEMENT OF THE ACTIVITY IS
SLOWLY TO THE SOUTH/SOUTHEAST AND EXPECT THAT THIS WILL NOT IMPACT
THE FORECAST AREA THIS MORNING. OTHER SHOWERS HAVE DEVELOPED THIS
MORNING OVER NORTH CENTRAL WISCONSIN ALONG THE LEADING EDGE OF A
WEAK BOUNDARY THAT HAS PUSHED IN FROM THE EAST. AS THE FLOW AHEAD
OF THIS BOUNDARY BECOMES MORE SOUTH TO SOUTHWEST...ANTICIPATE THAT
IT WILL START TO RETREAT WITH ANY SHOWERS ALONG MOVING OUT OF THE
AREA BY MID MORNING. AFTER THAT...A FAIR AMOUNT OF UNCERTAINTY ON
HOW THE REST OF THE DAY WILL PLAY OUT. THE 21.00Z NAM SUGGESTS A
WEAK SHORT WAVE TROUGH WILL MOVE ACROSS THE AREA THIS AFTERNOON
AND EVENING WHILE THE 21.00Z GFS REALLY DOES NOT SHOW THIS
FEATURE. LOOKING AT THE WATER VAPOR IMAGERY...IT DOES SUGGEST
THERE COULD BE A WEAK WAVE COMING ACROSS THE DAKOTAS SIMILAR TO
WHAT THE NAM INDICATES. WHETHER THIS WAVE WILL PRODUCE ANY
CONVECTION IS QUESTIONABLE AS WELL. THE NAM ONLY SHOWS SOME WEAK
PV ADVECTION IN THE 500-300 MB LAYER WITH LITTLE OR NO MOISTURE
TRANSPORT INTO THE REGION. DESPITE THIS...IT DEVELOPS SOME
CONVECTION ACROSS IOWA WHICH IS SIMILAR TO WHAT THE 21.00Z ECMWF
SHOWS. THE GFS...DESPITE NOT HAVING THE WAVE...BLOWS UP EVEN MORE
CONVECTION OVER MUCH OF THE AREA. THE 21.00Z HI-RES ARW SUGGESTS
THAT ANY CONVECTION SHOULD DEVELOP SOUTHEAST OF THE AREA IN
CONJUNCTION WITH THE MCV THAT MOVES OUT OF THE ONGOING IOWA
CONVECTION. WILL JUST CARRY SOME 20 TO 30 PERCENT AFTERNOON RAIN
CHANCES WITH THE HIGHER CHANCES ACROSS THE SOUTH AND EAST SECTIONS
TO FAVOR THE NAM AND ARW SOLUTIONS.
FAIRLY GOOD AGREEMENT THAT A STRONGER SHORT WAVE TROUGH WILL CROSS
THE ROCKIES IN THE ZONAL FLOW AND MOVE ACROSS THE UPPER MIDWEST
LATE TONIGHT THROUGH SUNDAY. SOME DIFFERENCES WITH THE TIMING OF
THIS WAVE WITH THE NAM FASTER TO BRING IT IN THAN THE GFS OR
ECMWF. THIS WAVE SHOULD BE ABLE TO PRODUCE SOME WEAK TO MODERATE
PV ADVECTION IN THE 500-300 MB LAYER WITH 3 TO 6 UBAR/S OF UP
GLIDE ON THE 305K ISENTROPIC SURFACE. EXPECT THAT THE AREA WILL BE
CAUGHT IN BETWEEN SYSTEMS THIS EVENING WITH THE POSSIBILITY OF
SOME DYING ACTIVITY FROM ANYTHING THAT DEVELOPS TODAY AND AN
INCREASE OVERNIGHT AHEAD OF THE APPROACHING WAVE...ESPECIALLY
ACROSS THE WEST. THE FORCING FROM THIS WAVE WILL CONTINUE TO
SLOWLY INCREASE SUNDAY AS IT PUSHES A WEAK SURFACE BOUNDARY TOWARD
THE AREA AS WELL. WILL SHOW THE RAIN CHANCES INCREASING TO ABOUT
40 PERCENT LATE TONIGHT ACROSS THE WEST AND UP TO 50 PERCENT FOR
MUCH OF THE AREA SUNDAY.
AS THIS SHORT WAVE TROUGH MOVES PAST THE AREA...THE GENERAL
CONSENSUS AMONG THE MODELS IS THAT IT WILL BE QUICKLY FOLLOWED BY
ANOTHER ONE FOR SUNDAY NIGHT AND MONDAY. THIS SHOULD PRODUCE
ANOTHER ROUND OF WEAK PV ADVECTION...2-6 UBAR/S OF UP GLIDE ON THE
305K ISENTROPIC SURFACE ALONG WITH SOME WEAK FRONTOGENESIS IN THE
850-500 MB LAYER. THE WEAK SURFACE BOUNDARY THAT GETS PUSHED INTO
THE AREA SUNDAY WILL STILL BE OVER THE REGION WITH THE NAM AND
ECMWF SHOWING A WEAK SURFACE LOW MOVING ALONG THE BOUNDARY. THIS
SHOULD BE ENOUGH TO PRODUCE A FAIR AMOUNT OF CONVECTION AND WILL
CONTINUE WITH 40 TO 50 PERCENT RAIN CHANCES SUNDAY NIGHT
INCREASING TO 60 PERCENT ACROSS THE SOUTHEAST FOR MONDAY.
THE RISK FOR ORGANIZED SEVERE WEATHER LOOKS PRETTY LOW THROUGH
MONDAY. WHILE DECENT CAPE SHOULD BE AVAILABLE EACH DAY...1000-2000
J/KG OF ML CAPE...THE WIND SHEAR LOOKS MARGINAL. THE 0-3KM SHEAR
LOOKS TO BE 20 TO 30 KNOTS EACH DAY WHICH COULD SUPPORT SOME
STRONG STORMS WITH A LITTLE BIT OF WIND POTENTIAL.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 316 AM CDT SAT JUN 21 2014
THE UNSETTLED PATTERN LOOKS TO CONTINUE THROUGH MUCH OF THE WEEK.
AT SOME POINT...THE REMAINS OF THE UPPER LEVEL LOW CURRENTLY OVER
MANITOBA WILL BECOME AN OPEN WAVE AND TRACK ACROSS THE UPPER
MIDWEST. WITH THE WEAK ZONAL FLOW...THIS DOES NOT LOOK TO BE A
QUICK PROCESS AND COULD TAKE MOST OF THE WEEK BEFORE IT FINALLY
MOVES PAST THE REGION. THIS WILL CONTINUE TO PROVIDE A CHANCE OF
RAIN TO THE AREA THROUGH THE WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1236 PM CDT SAT JUN 21 2014
A BAND OF LIGHT RAIN SHOWERS AND UPPER LEVEL CLOUD COVER WILL
SHIFT TO THE EAST QUICKLY THIS AFTERNOON WITH THE REMNANTS OF AN
OVERNIGHT STORM SYSTEM MOVING INTO CENTRAL WISCONSIN. SKIES WILL
CLEAR OUT WITH WINDS REMAINING LIGHT THROUGH TOMORROW MORNING AS A
WEAK RIDGE OF HIGH PRESSURE MOVES IN. WINDS WILL SHIFT AROUND TO
THE SOUTHEAST TOMORROW MORNING AHEAD OF THE NEXT SYSTEM WHICH MAY
BRING SOME THUNDERSTORMS IN ON SUNDAY AFTERNOON/EVENING.
&&
.HYDROLOGY...
ISSUED AT 316 AM CDT SAT JUN 21 2014
MANY OF THE RIVERS ACROSS THE AREA REMAIN HIGH OR ARE FLOODING
FROM ALL THE RECENT RAINS. LATEST INDICATIONS ARE THAT OUTSIDE
OF THE MISSISSIPPI RIVER...A LOT OF THE RIVERS ARE CRESTING OR
VERY CLOSE TO CRESTING AND SHOULD START TO GO DOWN HEADING THROUGH
THE WEEKEND. CRESTS ON THE MISSISSIPPI RIVER ARE NOT EXPECTED TO
START OCCURRING UNTIL ABOUT THE MIDDLE OF THE WEEK. SEE THE LATEST
FLOOD STATEMENTS FOR SPECIFIC FORECAST INFORMATION.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...HALBACH
SHORT TERM...04
LONG TERM...04
AVIATION...HALBACH
HYDROLOGY...04
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1213 PM CDT SAT JUN 21 2014
.UPDATE...REMNANT MESOSCALE CONVECTIVE VORTEX SHIFTING TOWARD THE
AREA FROM THE WEST. THIS FEATURE IS EXPECTED TO SHIFT THROUGH THE
AREA THIS AFTERNOON. AREA OF SHOWERS SEEN WITH THIS FEATURE. MORE
ISOLATED SHOWERS AND STORMS WERE OBSERVED EAST OF THIS FEATURE AS
WELL. MESOSCALE MODELS TRYING TO SHOW SCATTERED SHOWERS AND STORMS
DEVELOPING BY EARLY THIS AFTERNOON ACROSS PORTIONS OF THE
AREA...THEN SHIFTING EAST SOUTHEAST THROUGH THE AREA BY 22Z.
0 TO 6 KM SHEAR IS WEAK BUT EFFECTIVE LAYER SHEAR IS BETTER. SPC
HAS PARTS OF THE SOUTHWEST COUNTIES IN SLIGHT RISK SEVERE THIS
AFTERNOON. A FEW STRONG TO SEVERE STORMS ARE POSSIBLE HERE GIVEN
EXPECTED MEAN LAYER CAPES AND EFFECTIVE SHEAR PROFILES. AREA
FORECAST SOUNDINGS FROM RAP/NAM/GFS SHOWING MEAN LAYER CAPE OF
1500 TO 2000 J/KG DEVELOPING IN THE WESTERN PORTIONS OF THE AREA.
LOW CLOUDS WOULD HAVE TO CLEAR THE EASTERN PORTIONS OF THE AREA TO
GET THAT UNSTABLE. MODELS ARE TRYING TO MIX OUT THIS LOW
DECK...BUT CURRENT TRENDS SUGGEST THAT IT WILL LINGER FOR A GOOD
PART OF THE AFTERNOON...IF NOT ALL OF IT. THIS WOULD ALSO
REINFORCE SURFACE BOUNDARY RUNNING NORTHWEST TO SOUTHEAST ACROSS
SOUTH CENTRAL WISCONSIN...WHICH MAY AID WITH LOW LEVEL
CONVERGENCE.
FOR NOW...WILL CONTINUE TO BRING IN CHANCE/SCATTERED POPS THIS
AFTERNOON...ESPECIALLY IN THE SOUTHERN PORTIONS OF THE AREA.
TEMPERATURES JUMPED INTO THE UPPER 70S TO LOWER 80S IN THE WEST
WHERE THERE WAS SOME SUNSHINE...AND SHOULD RISE INTO THE LOWER TO
MID 80S. THE EAST REMAINS IN THE 60S WITH THE LOW STRATUS. MAY
LOWER HIGHS IN THE EAST WITH CLOUDS LIKELY TO REMAIN.
&&
.AVIATION/18Z TAFS/...MADISON SHOULD SEE CEILINGS RISE ABOVE MVFR
LEVELS BY EARLY THIS AFTERNOON. BETTER CHANCES FOR SHOWERS AND
STORMS ARE HERE...WILL MENTION VICINITY THUNDER FOR NOW IN TAFS
UNTIL 22Z. MVFR VISIBILITIES ARE POSSIBLE IN ANY STORMS.
THE EASTERN SITES SHOULD SEE CEILINGS RISE ABOVE ALTERNATE
MINIMUMS EARLY THIS AFTERNOON...THEN REMAIN IN THE MVFR/IFR AREA
THROUGH THE REST OF THE AFTERNOON INTO THIS EVENING. MAY SEE SOME
PEAKS OF SUN...BUT CURRENT TRENDS SUGGEST THIS LOW STRATUS DECK
WILL LINGER. ALSO WILL MENTION VICINITY THUNDER UNTIL 22Z.
LOW STRATUS AND FOG...POSSIBLY DENSE FOG...WILL RETURN TO THE
EASTERN SITES BY 03Z SUNDAY...AND LINGER INTO AT LEAST 15Z SUNDAY.
EXPECT VISIBILITIES DOWN TO 1/4 TO 1/2 MILE HERE AFTER 06Z
SUNDAY...WITH CEILINGS DOWN TO 100 TO 200 FEET ABOVE GROUND LEVEL.
THESE CONDITIONS WILL APPROACH OR REACH AIRPORT MINIMUMS.
MADISON MAY SEE LOW STRATUS MOVE BACK IN AS WELL AFTER 06Z
SUNDAY...LINGERING TO AROUND 15Z SUNDAY. CEILINGS NEAR ALTERNATE
MINIMUMS WITH VISIBILITIES DOWN TO 1/2 MILE ARE POSSIBLE. 1/4 MILE
VISIBILITIES NOT OUT OF THE QUESTION HERE EITHER...NEAR AIRPORT
MINIMUMS.
SHOULD SEE CONDITIONS SLOWLY IMPROVE IN THE LATE MORNING AND
AFTERNOON TO MVFR OR BETTER.
&&
.MARINE...EXTENDED THE MARINE DENSE FOG ADVISORY UNTIL 15Z
SUNDAY. AREA WEB CAMERAS STILL SHOWING DENSE FOG OVER THE
WATER...WITH WARM MOIST AIR MASS OVER COLD LAKE WATERS. THIS
SHOULD PERSIST INTO AT LEAST MID MORNING ON SUNDAY...PERHAPS
LONGER. MAY NEED TO EXTEND FURTHER OUT TOMORROW MORNING IF
CONDITIONS DO NOT IMPROVE.
&&
.PREV DISCUSSION... /ISSUED 339 AM CDT SAT JUN 21 2014/
SHORT TERM...
TODAY AND TONIGHT...FORECAST CONFIDENCE IS MEDIUM.
WE HAVE A RATHER COMPLICATED FORECAST FOR TODAY AND TONIGHT. FOR
STARTERS...A LARGE AREA OF LOW STRATUS/FOG AND COOL AIR HAS
OVERSPREAD THE AREA FROM AN EASTERLY FLOW OFF LAKE MICHIGAN. THE
EXACT DISSIPATION OF THIS DECK IS ALWAYS TRICKY AND WILL LIKELY
IMPACT THE AIRSHOW SCHEDULED FOR THE LAKE SHORE OF MILWAUKEE TODAY.
A DENSE FOG ADVISORY IS IN EFFECT FOR THE LAKE SHORE COUNTIES
THROUGH 9 AM. IN GENERAL...VISIBILITIES ARE BETTER THAN 1/2
MILE...BUT AREA WEB CAMS SHOW SOME SPOTTY DENSE FOG...ESPECIALLY
RIGHT ALONG THE LAKE. SO IT/S PRUDENT TO KEEP THIS GOING THROUGH MID
MORNING.
THE WESTERN EDGE OF THE STRATUS DECK...WEST OF MADISON EARLY THIS
MORNING...IS DEFINING A STATIONARY FRONTAL BOUNDARY THAT EXTENDS UP
TO A SURFACE LOW OVER EASTERN MINNESOTA. MEANWHILE...MANY OF THE
MODELS ARE FIRING OFF SOME ELEVATED CONVECTION THAT PUSHES ACROSS
THE CWA THIS MORNING. THIS IS IN ASSOCIATION WITH AN H7 TROF AND
RIGHT ENTRANCE REGION OF A DEPARTING UPPER JET. AT THIS
WRITING...THAT CONVECTION HASN/T STARTED YET AND CONFIDENCE ISN/T
HIGH THAT IT WILL. SO SMALL POPS WILL COVER THAT FOR NOW AND WILL
ADJUST IF IT STARTS TO SHOW ITS HAND...OR NOT. NOTHING WILL BE
SURFACE BASED DUE TO THE RATHER DEEP CAPPING FROM THE COOLER FLOW
OFF THE LAKE.
FOR THIS AFTERNOON...THE MODEL SOUNDINGS SUGGEST THE STRATUS AND
IT/S SUPPORTIVE LOW LEVEL INVERSION WILL MIX OUT BY AROUND NOON. THE
SOUNDINGS SHOW UNCAPPED CAPE OF ABOUT 1500J/KG AVAILABLE THIS
AFTERNOON AND WITH THE WEAK FRONTAL BOUNDARY STILL LINGERING...WE
COULD SEE A FEW THUNDERSTORMS DEVELOP. DEEP LAYER BULK SHEAR IS ON
THE WEAK SIDE...GENERALLY LESS THAN 30KTS...WITH PARAMETERS LOOKING
BETTER TO THE SOUTH. IF WE GET DECENT DIFFERENTIAL HEATING ALONG
THE EDGE OF THE STATUS...WE COULD SEE A STRONGER SURFACE BOUNDARY
AND LLV CONVERGENCE. SPC HAS CLIPPED OUR FAR SOUTH WITH A SLIGHT
RISK FOR SVR STORMS. ALTHOUGH IT APPEARS THE BEST CHANCE FOR THE
STRONGEST STORMS WILL BE TO OUR SOUTH...THE HIRES ARW AND NMM MODELS
BOTH SHOW SOMETHING ROLLING EAST ALONG THE STATE LINE.
LOTS OF UNCERTAINTY WITH OVERALL WEAK FORCING WITHIN A MODERATELY
UNSTABLE AIRMASS. THE COLDER LOW LEVEL STRATUS JUST COMPLICATES
THINGS. SO WILL KEEP POPS ON THE LOWER SIDE WHICH MATCHES THE
CONSENSUS OF THE MODELS AND THINKING OF SURROUNDING OFFICES.
A BACKDOOR COLD FRONT IS EXPECTED TO DROP THROUGH THE AREA THIS
EVENING IN THE WAKE OF A LOW PRESSURE SYSTEM SCOOTING EAST. THIS
SHOULD SET THE STAGE FOR MORE FOG AND POSSIBLE LOW CLOUDS.
AVIATION/12Z TAFS/...
A VERY DIFFICULT FORECAST INDEED. THE COOL EASTERLY FLOW OFF THE
LAKE HAS COMBINED WITH THE MOIST AIRMASS IN PLACE THE LAST FEW
DAYS...RESULTING IN A HUGE LOWER STRATUS DECK THAT COVERS MUCH OF
ERN WISCONSIN AND NRN IL. IT/S CONSISTENTLY 200-300 AGL ACROSS THE
AREA. THE LATEST AMDAR AIRCRAFT AND RAP SOUNDING SHOW THIS TO BE
ABOUT 2-2.5KFT THICK. THE RAP MIXES IT OUT IN THE MILWAUKEE AREA BY
AROUND 17-18Z THIS AFTERNOON...SO IT SHOULD HANG IN TIGHT THROUGH
THE MORNING. THE EROSION AT KMSN IS AROUND 15Z. ONCE IT STARTS TO
OPEN UP...IT WILL LIKELY LIFT INTO TO STRATOCU DECK BEFORE
SCATTERING OUT. THE FOG/LOWER VSBYS SHOULD IMPROVE AFTER
SUNRISE...AS WE START TO HEAT THINGS UP AND PUT A LITTLE DISTANCE
BETWEEN THE TEMP AND DEWPOINT.
THEN WE HAVE THE CHANCE FOR SHOWERS AND THUNDERSTORMS. THE BEST
CHANCE FOR ANY STORMS LOOKS TO BE FROM ABOUT 20Z-01Z...OR
TRADITIONAL PEAK HEATING. THERE WILL BE A WEAK FRONTAL BOUNDARY IN
THE AREA THAT MAY ACT AS A FOCUS FOR THUNDERSTORM DEVELOPMENT. WE
WILL BE IN A WEAK FLOW...MODERATELY UNSTABLE ENVIRONMENT THIS
AFTERNOON...SO THERE IS PLENTY OF UNCERTAINTY.
MORE FOG IS EXPECTED TONIGHT AS A BACKDOOR COLD FRONT SWEEPS DOWN
THE LAKE AS WEAK LOW PRESSURE SCOOTS EAST. OF COURSE THIS MEANS MORE
FOG AND POSSIBLY LOWER STRATUS AGAIN TONIGHT.
LONG TERM...
SUNDAY THROUGH TUESDAY NIGHT...FORECAST CONFIDENCE MEDIUM.
THERE IS A CHANCE FOR SHOWERS AND THUNDERSTORMS DURING THE DAY
SUNDAY WITH WEAK 850MB FRONTOGENESIS AND 700 MB UPWARD MOTION.
FORECAST SOUNDINGS FOR MADISON SHOW BUILDING CAPE THROUGH THE
AFTERNOON WITH NO CAP. HOWEVER...LOW POPS BECAUSE WE MIGHT LACK A
TRIGGER FOR ANY THUNDERSTORMS TO DEVELOP DUE TO MID LEVEL RIDGING
OVERHEAD. IF THUNDERSTORMS DEVELOP...THE SHEAR IS WEAK SO NOT
LOOKING FOR SEVERE STORMS DURING THE DAY.
NEAR THE LAKE...WINDS WILL CONTINUE TO BE LIGHT AND EASTERLY ON
SUNDAY. THIS SHOULD CONTINUE THE FOG AND STRATUS OVER THE NEARSHORE
WATERS THROUGH AT LEAST EARLY AFTERNOON.
THE BETTER CHANCE FOR THUNDERSTORMS WILL COME LATER SUNDAY
NIGHT THROUGH TUE NIGHT AS A MID LEVEL SHORTWAVE VERY SLOWLY TRACKS
THROUGH MN AND WI. THE LOW LEVEL JET WILL POINT INTO SOUTHERN WI
LATE SUNDAY NIGHT INTO MONDAY MORNING...WHICH WILL ALSO BE
COINCIDENT WITH THE HIGH PRECIPITABLE WATER VALUES.
BY MONDAY AND MONDAY NIGHT...THE MID LEVEL TROUGH WILL BE MOVING
OVERHEAD ALONG WITH A SURFACE LOW PRESSURE TROUGH. RAIN AND
THUNDERSTORMS ARE MOST LIKELY DURING THIS PERIOD.
TUESDAY THROUGH FRIDAY...FORECAST CONFIDENCE MEDIUM.
SURFACE HIGH PRESSURE WILL SETTLE OVER LAKE SUPERIOR LATER NEXT
WEEK. ZONAL MID LEVEL FLOW AND AN 850MB FRONT STATIONED APPROX OVER
SOUTHWEST WI WILL ALLOW FOR MORE SHOWER AND ISOLATED THUNDERSTORM
DEVELOPMENT...ESPECIALLY IN SOUTH CENTRAL WI INLAND FROM THE LAKE.
BEST CHANCE FOR PRECIP WILL BE EACH AFTERNOON. THERE ARE STILL
TIMING AND COVERAGE DIFFERENCES BETWEEN THE MODELS. STAY TUNED.
EASTERLY WINDS WILL KEEP LAKESHORE TEMPS COOLER. INLAND TEMPS ARE
EXPECTED IN THE UPPER 70S.
AVIATION/12Z TAFS/...
A VERY DIFFICULT FORECAST INDEED. THE COOL EASTERLY FLOW OFF THE
LAKE HAS COMBINED WITH THE MOIST AIRMASS IN PLACE THE LAST FEW
DAYS...RESULTING IN A HUGE LOWER STRATUS DECK THAT COVERS MUCH OF
ERN WISCONSIN AND NRN IL. IT/S CONSISTENTLY 200-300 AGL ACROSS THE
AREA. THE LATEST AMDAR AIRCRAFT AND RAP SOUNDING SHOW THIS TO BE
ABOUT 2-2.5KFT THICK. THE RAP MIXES IT OUT IN THE MILWAUKEE AREA BY
AROUND 17-18Z THIS AFTERNOON...SO IT SHOULD HANG IN TIGHT THROUGH
THE MORNING. THE EROSION AT KMSN IS AROUND 15Z. ONCE IT STARTS TO
OPEN UP...IT WILL LIKELY LIFT INTO TO STRATOCU DECK BEFORE
SCATTERING OUT. THE FOG/LOWER VSBYS SHOULD IMPROVE AFTER
SUNRISE...AS WE START TO HEAT THINGS UP AND PUT A LITTLE DISTANCE
BETWEEN THE TEMP AND DEWPOINT.
THEN WE HAVE THE CHANCE FOR SHOWERS AND THUNDERSTORMS. THE BEST
CHANCE FOR ANY STORMS LOOKS TO BE FROM ABOUT 20Z-01Z...OR
TRADITIONAL PEAK HEATING. THERE WILL BE A WEAK FRONTAL BOUNDARY IN
THE AREA THAT MAY ACT AS A FOCUS FOR THUNDERSTORM DEVELOPMENT. WE
WILL BE IN A WEAK FLOW...MODERATELY UNSTABLE ENVIRONMENT THIS
AFTERNOON...SO THERE IS PLENTY OF UNCERTAINTY.
MORE FOG IS EXPECTED TONIGHT AS A BACKDOOR COLD FRONT SWEEPS DOWN
THE LAKE AS WEAK LOW PRESSURE SCOOTS EAST. OF COURSE THIS MEANS MORE
FOG AND POSSIBLY LOWER STRATUS AGAIN TONIGHT.
MARINE...
DENSE FOG IS EXPECTED THROUGH ABOUT MID MORNING. THE NEARSHORE AREAS
MAY REMAIN IN A LIGHT FOG THROUGH THE DAY WITH MORE DENSE FOG
POSSIBLE TONIGHT AS A COLD FRONT MOVES SOUTH DOWN THE LAKE SHORE.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...DENSE FOG ADVISORY UNTIL 10 AM CDT SUNDAY FOR LMZ643>646.
&&
$$
UPDATE...WOOD
TODAY/TONIGHT AND AVIATION/MARINE...DAVIS
SUNDAY THROUGH FRIDAY...MRC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1137 AM CDT SAT JUN 21 2014
.UPDATE...
ISSUED AT 1137 AM CDT SAT JUN 21 2014
REMNANT MCV FROM LAST NIGHTS CONVECTION FURTHER SOUTHWEST IS
CURRENTLY TRACKING EAST ACROSS NORTHEAST IOWA/SOUTHWEST WISCONSIN.
THIS HAS LEAD TO MUCH MORE CLOUD COVER AND SOME LIGHT RAIN SHOWERS
ALONG THE MISSISSIPPI RIVER. 16Z RAP ANALYSIS SHOWS THE BETTER
SB/MLCAPE CHANNEL RUNNING OUT AHEAD OF THIS MCV INTO
SOUTHWEST/WEST CENTRAL WISCONSIN WITH IT BULLSEYED ON THE DELLS.
THE MAIN CONVECTIVE CHANCES WILL BE OVER THE NEXT FEW HOURS BEFORE
THIS FEATURE MOVES OFF TO THE EAST BY MID AFTERNOON. ONCE IT DOES
MOVE OFF TO THE EAST...IT APPEARS THAT WE WILL SEE A DRY PERIOD
GOING THROUGH TONIGHT AS A RIDGE OF HIGH PRESSURE MOVES IN WITH
DRIER/STABLE AIR. THUS...HAVE ADJUSTED TRENDS TO BE
CLOUDIER/RAINIER THIS MORNING/EARLY AFTERNOON AND THEN DROPPED
CHANCES FOR PRECIPITATION FOR LATE THIS AFTERNOON/EARLY EVENING.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 316 AM CDT SAT JUN 21 2014
MAIN FORECAST CONCERN IS WITH THE RAIN CHANCES THROUGH THE PERIOD.
REGIONAL RADARS SHOWING A CONVECTIVE COMPLEX THIS MORNING OVER
SOUTHWEST IOWA INTO SOUTHERN NEBRASKA. MOVEMENT OF THE ACTIVITY IS
SLOWLY TO THE SOUTH/SOUTHEAST AND EXPECT THAT THIS WILL NOT IMPACT
THE FORECAST AREA THIS MORNING. OTHER SHOWERS HAVE DEVELOPED THIS
MORNING OVER NORTH CENTRAL WISCONSIN ALONG THE LEADING EDGE OF A
WEAK BOUNDARY THAT HAS PUSHED IN FROM THE EAST. AS THE FLOW AHEAD
OF THIS BOUNDARY BECOMES MORE SOUTH TO SOUTHWEST...ANTICIPATE THAT
IT WILL START TO RETREAT WITH ANY SHOWERS ALONG MOVING OUT OF THE
AREA BY MID MORNING. AFTER THAT...A FAIR AMOUNT OF UNCERTAINTY ON
HOW THE REST OF THE DAY WILL PLAY OUT. THE 21.00Z NAM SUGGESTS A
WEAK SHORT WAVE TROUGH WILL MOVE ACROSS THE AREA THIS AFTERNOON
AND EVENING WHILE THE 21.00Z GFS REALLY DOES NOT SHOW THIS
FEATURE. LOOKING AT THE WATER VAPOR IMAGERY...IT DOES SUGGEST
THERE COULD BE A WEAK WAVE COMING ACROSS THE DAKOTAS SIMILAR TO
WHAT THE NAM INDICATES. WHETHER THIS WAVE WILL PRODUCE ANY
CONVECTION IS QUESTIONABLE AS WELL. THE NAM ONLY SHOWS SOME WEAK
PV ADVECTION IN THE 500-300 MB LAYER WITH LITTLE OR NO MOISTURE
TRANSPORT INTO THE REGION. DESPITE THIS...IT DEVELOPS SOME
CONVECTION ACROSS IOWA WHICH IS SIMILAR TO WHAT THE 21.00Z ECMWF
SHOWS. THE GFS...DESPITE NOT HAVING THE WAVE...BLOWS UP EVEN MORE
CONVECTION OVER MUCH OF THE AREA. THE 21.00Z HI-RES ARW SUGGESTS
THAT ANY CONVECTION SHOULD DEVELOP SOUTHEAST OF THE AREA IN
CONJUNCTION WITH THE MCV THAT MOVES OUT OF THE ONGOING IOWA
CONVECTION. WILL JUST CARRY SOME 20 TO 30 PERCENT AFTERNOON RAIN
CHANCES WITH THE HIGHER CHANCES ACROSS THE SOUTH AND EAST SECTIONS
TO FAVOR THE NAM AND ARW SOLUTIONS.
FAIRLY GOOD AGREEMENT THAT A STRONGER SHORT WAVE TROUGH WILL CROSS
THE ROCKIES IN THE ZONAL FLOW AND MOVE ACROSS THE UPPER MIDWEST
LATE TONIGHT THROUGH SUNDAY. SOME DIFFERENCES WITH THE TIMING OF
THIS WAVE WITH THE NAM FASTER TO BRING IT IN THAN THE GFS OR
ECMWF. THIS WAVE SHOULD BE ABLE TO PRODUCE SOME WEAK TO MODERATE
PV ADVECTION IN THE 500-300 MB LAYER WITH 3 TO 6 UBAR/S OF UP
GLIDE ON THE 305K ISENTROPIC SURFACE. EXPECT THAT THE AREA WILL BE
CAUGHT IN BETWEEN SYSTEMS THIS EVENING WITH THE POSSIBILITY OF
SOME DYING ACTIVITY FROM ANYTHING THAT DEVELOPS TODAY AND AN
INCREASE OVERNIGHT AHEAD OF THE APPROACHING WAVE...ESPECIALLY
ACROSS THE WEST. THE FORCING FROM THIS WAVE WILL CONTINUE TO
SLOWLY INCREASE SUNDAY AS IT PUSHES A WEAK SURFACE BOUNDARY TOWARD
THE AREA AS WELL. WILL SHOW THE RAIN CHANCES INCREASING TO ABOUT
40 PERCENT LATE TONIGHT ACROSS THE WEST AND UP TO 50 PERCENT FOR
MUCH OF THE AREA SUNDAY.
AS THIS SHORT WAVE TROUGH MOVES PAST THE AREA...THE GENERAL
CONSENSUS AMONG THE MODELS IS THAT IT WILL BE QUICKLY FOLLOWED BY
ANOTHER ONE FOR SUNDAY NIGHT AND MONDAY. THIS SHOULD PRODUCE
ANOTHER ROUND OF WEAK PV ADVECTION...2-6 UBAR/S OF UP GLIDE ON THE
305K ISENTROPIC SURFACE ALONG WITH SOME WEAK FRONTOGENESIS IN THE
850-500 MB LAYER. THE WEAK SURFACE BOUNDARY THAT GETS PUSHED INTO
THE AREA SUNDAY WILL STILL BE OVER THE REGION WITH THE NAM AND
ECMWF SHOWING A WEAK SURFACE LOW MOVING ALONG THE BOUNDARY. THIS
SHOULD BE ENOUGH TO PRODUCE A FAIR AMOUNT OF CONVECTION AND WILL
CONTINUE WITH 40 TO 50 PERCENT RAIN CHANCES SUNDAY NIGHT
INCREASING TO 60 PERCENT ACROSS THE SOUTHEAST FOR MONDAY.
THE RISK FOR ORGANIZED SEVERE WEATHER LOOKS PRETTY LOW THROUGH
MONDAY. WHILE DECENT CAPE SHOULD BE AVAILABLE EACH DAY...1000-2000
J/KG OF ML CAPE...THE WIND SHEAR LOOKS MARGINAL. THE 0-3KM SHEAR
LOOKS TO BE 20 TO 30 KNOTS EACH DAY WHICH COULD SUPPORT SOME
STRONG STORMS WITH A LITTLE BIT OF WIND POTENTIAL.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 316 AM CDT SAT JUN 21 2014
THE UNSETTLED PATTERN LOOKS TO CONTINUE THROUGH MUCH OF THE WEEK.
AT SOME POINT...THE REMAINS OF THE UPPER LEVEL LOW CURRENTLY OVER
MANITOBA WILL BECOME AN OPEN WAVE AND TRACK ACROSS THE UPPER
MIDWEST. WITH THE WEAK ZONAL FLOW...THIS DOES NOT LOOK TO BE A
QUICK PROCESS AND COULD TAKE MOST OF THE WEEK BEFORE IT FINALLY
MOVES PAST THE REGION. THIS WILL CONTINUE TO PROVIDE A CHANCE OF
RAIN TO THE AREA THROUGH THE WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 629 AM CDT SAT JUN 21 2014
WEAK LOW PRESSURE WILL EDGE TOWARDS THE TAF SITES TODAY AND MAY
GENERATE AN ISOLATED SHOWER OR THUNDERSTORM. HOWEVER...CONFIDENCE
ON ANY OF THIS ACTIVITY IMPACTING THE TAF SITES IS LOW SO HAVE NOT
INCLUDED IN THE TAFS AT THIS TIME. OTHERWISE...PLAN ON VFR
CONDITIONS TODAY. SCT TO BKN MID TO HIGH LEVEL CLOUDS ARE EXPECTED
LATE THIS MORNING INTO THIS AFTERNOON WITH BASES IN THE 15-20KFT
RANGE. NAM FORECAST SOUNDINGS ARE TRYING TO PRODUCE SOME LIGHT
FOG AT KSLE LATE TONIGHT INTO EARLY SUNDAY MORNING SO WILL HAVE TO
KEEP AN EYE ON THIS. TEMPERATURE AND DEWPOINT SPREADS APPEAR TO
HIGH FOR FOG FORMATION SO WILL NOT INCLUDE IT IN THE TAF AT THIS
TIME.
&&
.HYDROLOGY...
ISSUED AT 316 AM CDT SAT JUN 21 2014
MANY OF THE RIVERS ACROSS THE AREA REMAIN HIGH OR ARE FLOODING
FROM ALL THE RECENT RAINS. LATEST INDICATIONS ARE THAT OUTSIDE
OF THE MISSISSIPPI RIVER...A LOT OF THE RIVERS ARE CRESTING OR
VERY CLOSE TO CRESTING AND SHOULD START TO GO DOWN HEADING THROUGH
THE WEEKEND. CRESTS ON THE MISSISSIPPI RIVER ARE NOT EXPECTED TO
START OCCURRING UNTIL ABOUT THE MIDDLE OF THE WEEK. SEE THE LATEST
FLOOD STATEMENTS FOR SPECIFIC FORECAST INFORMATION.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...HALBACH
SHORT TERM...04
LONG TERM...04
AVIATION...WETENKAMP
HYDROLOGY...04
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
307 PM MDT SAT JUN 21 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 307 PM MDT SAT JUN 21 2014
STORMS HAVE DEVELOPED EARLY THIS AFTN OVER GOSHEN COUNTY AND HAVE
MOVED INTO THE CENTRAL AND NORTHERN PANHANDLE. THEY HAVE STRUGGLED
TO BECOME DISCRETE SO FAR DUE TO THE MARGINAL DEEP LAYER SHEAR
(25-30 KTS) AND HAVE FORMED INTO LINES/CLUSTERS. SPC MESOANALYSIS
SHOWS GOOD INSTABILITY WITH MLCAPES OF 1500-2000 J/KG OVER THE
PANHANDLE. BELIEVE THAT THE MAIN SVR THREAT DURING THE AFTN WILL
BE DAMAGING WINDS WITH THE HIGH LCLS AND DEEP BOUNDARY LAYER OVER
THE PANHANDLE. LARGE HAIL IS LESS OF THE THREAT WITH THE MARGINAL
DEEP LAYER SHEAR...HOWEVER MARGINALLY SVR HAIL WILL BE POSSIBLE. A
SEVERE THUNDERSTORM WATCH WAS ISSUED FOR ALL OF THE NEBRASKA
PANHANDLE THROUGH 03Z. ALL OF THIS STORM ACTIVITY IS OCCURING
AHEAD OF A SHORTWAVE THAT IS CURRENTLY LOCATED OVER WESTERN
COLORADO. THE HRRR MODEL SHOWS MOST STORMS PUSHING EAST OUT OF THE
CWA BY AROUND 00Z.
COLD FRONT BEHIND THE SHORTWAVE WILL PUSH ACROSS THE PLAINS LATE
TONIGHT AND SUNDAY MORNING. WINDS ARE STILL NORTHERLY AT 18Z SUN
AND THEN BECOME MORE NORTHEASTERLY DURING THE AFTN. MODELS HAVE
DECREASED INSTABILITY A BIT OVER YESTERDAYS RUN WITH LI VALUES OF
AROUND -3C IN LARAMIE/PLATTE COUNTIES AND EXTENDING EASTWARD ALONG
THE COLORADO BORDER. STORMS SHOULD DEVELOP BY AFTN IN THE
CONVERGENCE ALONG THE SOUTHERN LARAMIE RANGE...HOWEVER DO NOT
BELIEVE THEY WILL BECOME SVR AS THEY PUSH EASTWARD. STORM COVERAGE
WILL BE MORE LIMITED OVER THE PANHANDLE AS THE AIRMASS IS MORE
STABLE POST FRONTAL. TEMPS WILL BE 10-15 DEGREES COOLER ON SUNDAY.
FOR MONDAY SFC WINDS BECOME MORE SOUTHEASTERLY AND AIRMASS IS MORE
UNSTABLE THAN SUNDAY IN AREAS NEAR THE COLORADO BORDER. THIS IS
THE DAY AFTER THE FROPA...WHICH OFTEN TIMES LEADS TO A GREATER SVR
THREAT. NORTHWESTERLY FLOW ALOFT IS STRONG ENOUGH...COMBINED WITH
THE SOUTHEAST LLVL FLOW...TO PRODUCE 40-45 KTS OF DEEP LAYER SHEAR
SO THERE WILL LIKELY BE SOME SVR POTENTIAL ON MONDAY IN AREAS
ALONG INTERSTATE 80.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 307 PM MDT SAT JUN 21 2014
THE ACTIVE PATTERN WILL CONTINUE INTO NEXT WEEK AS ZONAL FLOW
BECOMES MORE SOUTHWESTERLY BY THE END OF THE WEEK. BOTH THE GFS
AND EURO SOLUTIONS CONTINUE TO ADVERTISE DAILY CHANCES OF
AFTERNOON AND EVENING CONVECTION AS SOUTHEASTERLY LLVL RETURN FLOW
PERSISTS ALL WEEK. THIS WILL RESULT IN PERSISTENT THETA-E RIDGING
OVER MUCH OF THE CWFA THROUGH THE ENTIRE WEEK. TUESDAY WILL BE THE
SECOND DAY POST-FRONTAL...WHICH WHEN COMBINED WITH 0-6KM SHEAR OF
40-50 KNOTS SHOULD SET THE STAGE FOR AN ACTIVE SEVERE WEATHER DAY.
THE GREATEST THREAT WILL BE EAST OF THE LARAMIE RANGE. PROGD
SBCAPES WILL FLARE TO BETWEEN 2000-3000 J/KG FOR WED AND
THU...WHICH SHOULD BE MORE THAN ENOUGH TO COMPENSATE FOR SOMEWHAT
LIGHTER VALUES OF DEEP LAYER SHEAR. WOULD EXPECT SEVERE POTENTIAL
TO CONTINUE FOR BOTH WED AND THU MAINLY EAST OF THE LARAMIE RANGE
AS WELL. TROUGH WILL SWING THROUGH ON FRIDAY...DRAGGING A PACIFIC
FRONT THRU THE AREA WHICH WILL EFFECTIVELY SHUNT BEST INSTABILITY
EAST OVER CENTRAL NEBRASKA FOR BOTH FRIDAY AND SATURDAY. AS A
RESULT...EXPECT THUNDERSTORM CHANCES TO TURN MORE ISOLATED EARLY
NEXT WEEKEND. TEMPERATURES WILL BE SEASONALLY PERSISTENT THROUGH
THE PERIOD WITH 70S ON TUESDAY WARMING INTO THE 80S AT LOWER
ELEVATIONS FOR THE REMAINDER OF THE WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY MORNING)
ISSUED AT 1148 AM MDT SAT JUN 21 2014
MAIN CONCERN FOR THIS FORECAST CYCLE IS THE THUNDERSTORM POTENTIAL
THIS AFTERNOON AND EVENING. THE KCYS RADAR IS ALREADY STARTING TO
LIGHT UP WITH SHOWERS AND THUNDERSTORMS DEVELOPING BETWEEN KCYS
AND KDGW. FOR NOW...HAVE KEPT VCTS IN THE TAFS GIVEN THE
UNCERTAINTY IN TIMING AND PRECISE LOCATION. WILL CONTINUE TO
MONTIOR THUNDERSTORM TRENDS THRU THE REST OF THE AFTERNOON MAINLY
FOR AIRFIELDS TO THE EAST OF THE LARAMIE RANGE. CONVECTION WILL
DISSIPATE BY AROUND SUNSET AS THE THUNDERSTORMS PUSH EAST TOWARDS
CENTRAL NEBRASKA. A COLD FRONTAL WILL PUSH SOUTH THROUGH THE AREA
TONIGHT...SO EXPECT WINDS TO TURN NORTHERLY ALONG WITH POTENTIALLY
A PERIOD OF MVFR CIGS AT KCDR/KAIA. NORTHERLY WINDS WILL TURN
GUSTY LATE SUNDAY MORNING WITH ANOTHER ROUND OF AFTERNOON
THUNDERSTORMS EXPECTED JUST BEYOND THIS TAF CYCLE FOR SUNDAY.
&&
.FIRE WEATHER...
ISSUED AT 307 PM MDT SAT JUN 21 2014
MINIMAL FIRE WEATHER CONCERNS THROUGH EARLY NEXT WEEK. MINIMUM
RELATIVE HUMIDITY VALUES WILL BE AROUND 15 PERCENT THIS AFTERNOON
FOR AREAS TO THE WEST OF THE LARAMIE RANGE. WEST WINDS WILL GUST TO
20-25 MPH THROUGH EARLY EVENING. SINCE FUELS ARE STILL GREEN ENOUGH
TO NOT SUPPORT FIRE GROWTH...NO CRITICAL FIRE WEATHER THREAT IS
EXPECTED. COOLER TEMPERATURES ON SUNDAY THROUGH EARLY NEXT WEEK
WILL CAUSE AFTERNOON HUMIDITY VALUES TO INCREASE TO THE 20-30
PERCENT RANGE FOR AREAS TO THE WEST OF THE LARAMIE RANGE. SCATTERED
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE EACH AFTERNOON THROUGH
THE MIDDLE OF NEXT WEEK...WITH COVERAGE HIGHEST TO THE EAST OF THE
LARAMIE RANGE.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...FINCH
LONG TERM...HAHN
AVIATION...HAHN
FIRE WEATHER...FINCH
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1150 AM MDT SAT JUN 21 2014
.UPDATE...
ISSUED AT 1100 AM MDT SAT JUN 21 2014
NOT A WHOLE LOT OF CHANGES MADE TO THE AFTN GRIDS. WEAK SHORTWAVE
IS SEEN ON WATER VAPOR IMAGERY OVER NORTHWEST COLORADO WITH
WIDESPREAD MID TO HIGH LEVEL CLOUDS CURRENTLY OVER SOUTHEAST WY. A
LITTLE WORRIED THAT THIS CLOUD COVER WILL LIMIT SFC HEATING AND
INSTABILITY THIS AFTN...ALTHOUGH WHERE STRONG TO SVR TSTM
POTENTIAL IS HIGHEST (NEBRASKA PANHANDLE) THERE HAS BEEN GOOD
WARMING THROUGH THE MORNING. THE HRRR MODEL HAS BEEN CONSISTENT AT
SHOWING A LARGE AREA OF SHOWERS AND EMBEDDED TSTMS OVER THE
PANHANDLE BETWEEN 22-01Z...WITH A MULTICELL APPEARANCE. WILL
CONTINUE THE MENTION OF SLIGHT RISK OF SVR STORMS IN THE
HWO...ALTHOUGH BULK SHEAR LOOKS A BIT MARGINAL AT 30-35 KTS FOR
MORE DISCRETE SUPERCELLS.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 312 AM MDT SAT JUN 21 2014
GLOBAL MODELS AND CURRENT WATER VAPOR IMAGERY SHOW A SHORTWAVE
APPROACHING FROM THE SOUTHWEST THAT IS PROGGED TO MOVE ACROSS OUR
AREA DURING THE AFTERNOON/EVENING HOURS TODAY. AT THE SURFACE...WE
NOTE A WELL DEFINED DRYLINE THAT EXTENDS FROM JUST NORTHWEST OF
CHADRON TO JUST EAST OF CHEYENNE. EAST OF THE DRYLINE MUCAPES ARE
RUNNING 400-800 J/KG ALREADY AND EXPECT BY THIS AFTERNOON WE WILL
SEE ENOUGH DEEP LAYERED INSTABILITY TO LIGHT OFF A FEW STRONG TO
SEVERE STORMS OVER THE NEBRASKA PANHANDLE WITH CAPES APPROACHING
2500 J/KG AND 1-6KM BULK SHEAR 25 TO 30 KTS ACROSS THE NORTHERN
NEBRASKA PANHANDLE...SUGGESTING THAT A FEW STORMS COULD START
TAKING ON SUPERCELL CHARACTERISTICS AS THEY MOVE EAST OUT OF
EASTERN WYOMING INTO NORTHWESTERN NEBRASKA. MODEL AND OBSERVED
SOUNDING DATA SHOW JUST ENOUGH OF A MIDLEVEL CAP TO HOLD BACK
CONVECTION UNTIL THE MID AFTERNOON HOURS...THEN BY 3 PM WE EXPECT
TO SEE SCATTERED STORMS INITIATING EAST OF A LUSK TO CHEYENNE
LINE...STRENGTHENING AS THEY MOVE EASTWARD INTO THE DEEPER
MOISTURE AND ZONE OF HIGHER INSTABILITY THROUGH LATE AFTERNOON
INTO THE EVENING HOURS. MAIN CONCERN FOR SEVERE STORMS IMPACTS
TODAY IS LARGE HAIL AND DAMAGING DOWNBURST WINDS IN EXCESS OF 60
MPH...MAINLY EAST OF A LINE FROM LUSK TO SIDNEY...ALTHOUGH
GREATEST POTENTIAL FOR VERY LARGE HAIL... HIGHER DOWNDRAFT WINDS
AND TO A LESSER DEGREE TORNADOES WILL BE FARTHER TO THE
EAST/NORTHEAST INTO SOUTH DAKOTA AND NORTHERN NEBRASKA WHERE SHEAR
VALUES FOR ORGANIZED UPDRAFTS WILL BE HIGHER.
LOOKING FARTHER TO THE WEST TODAY...LATEST HIGH RESOLUTION RAPID
REFRESH MODEL DOES HINT AT SOME WEAKER SHOWERS/STORMS FORMING UP
IN THE EARLY AFTERNOON IN THE HIGHER TERRAIN OVER OUR WESTERN
ZONES. WE CONTINUE TO MAINTAIN SLIGHT CHANCE/CHANCE POPS FOR
AFTERNOON SHOWERS AND STORMS IN THE WEST WITH THE EXCEPTION OF
THE WESTERN-MOST AREAS OF CARBON COUNTY. ANOTHER BREEZY DAY
EXPECTED ABOVE 8000 FT MSL WITH GUSTS TO 35 MPH POSSIBLE DURING
THE PEAK MECHANICAL MIXING PERIOD OF MID MORNING THROUGH LATE
AFTERNOON.
WE EXPECT ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS ON SUNDAY AS
A COLD FRONT SINKS SOUTHWARDS AND IS PROGGED IN THE MODELS TO BANK
UP ALONG AND EAST OF THE LARAMIE RANGE BY LATE AFTERNOON. MOST OF
THE STORMS SUNDAY SHOULD BE NOTED EAST OF A LINE FROM DOUGLAS TO
CHEYENNE IN THE REGION OF DEEPER MOISTURE AND INSTABILITY...WITH
LESS COVERAGE TO THE WEST. DEEP LAYERED INSTABILITY FOR STRONG
UPDRAFTS LOOKS A LITTLE MORE LIMITED ON SUNDAY...HOWEVER BULK
SHEAR VALUES ACROSS EASTERN WYOMING AND WESTERN NEBRASKA COULD GET
UP TO NEAR 30 KTS...SO A SMALL POTENTIAL FOR A FEW STRONGER
STORMS IS THERE. THE KEY THING WE WILL NEED TO WATCH FOR ON SUNDAY
WILL BE THE POTENTIAL FOR STORMS TO RE-DEVELOP OR TRAIN GRADUALLY
FROM NORTHWEST TO SOUTHEAST...MEANING SOME AREAS COULD SEE
MULTIPLE ROUNDS OF RAINFALL. QUESTION IS JUST HOW FAR SOUTH WILL
THE FRONTAL BOUNDARY GET AND IF WE WILL SEE ENHANCED BACK-BUILDING
OF STORMS WITH EAST/SOUTHEAST SURFACE FLOW WITH 25-35 KT MIDLEVEL
FLOW ABOVE IT. RIGHT NOW FORECAST CONFIDENCE AS TO IF OR WHERE ANY
FLASH FLOODING WOULD OCCUR ON SUNDAY IS NOT NEAR HIGH ENOUGH TO
WARRANT THE ISSUANCE OF A WATCH.
FOR MONDAY...MORE SCATTERED AFTERNOON SHOWERS AND THUNDERSTORMS
ARE EXPECTED FOR THE CENTRAL AND EASTERN ZONES IN THE REGION OF
DEEPER MOISURE.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 312 AM MDT SAT JUN 21 2014
MODELS IN GENERALLY GOOD AGREEMENT WITH THE OVERALL PATTERN
THROUGH MOST OF NEXT WEEK...ALTHOUGH SOME DIFFERENCES ARE NOTED
BY DAY 7 REGARDING THE TIMING OF AN UNUSUALLY STRONG UPPER LEVEL
TROUGH ACROSS THE PACIFIC NORTHWEST FOR THIS TIME OF THE YEAR. THE
WEATHER PATTERNS APPEARS TO BE PRETTY ACTIVE NEXT WEEK AS A SERIES
OF SHORTWAVE DISTURBANCES EMBEDDED WITHIN THE QUASI-ZONAL FLOW
PUSH ACROSS THE FORECAST AREA EACH DAY THROUGH THURSDAY.
A LOW LEVEL SURFACE BOUNDARY WILL BE THE PRIMARY FACTOR IN
DETERMINING CONVECTION INITIATION EACH DAY DUE TO AMPLE LLVL
CONVERGENCE AND ADDITIONAL INSTABILITY. THE BOUNDARY POSITION WILL
FLUCTUATE BETWEEN THE CONTINENTAL DIVIDE AND ALONG THE I25
CORRIDOR THROUGH THE PERIOD...RESULTING IN SOME DIFFICULTY IN
PINPOINTING WHERE THE HIGHEST POTENTIAL OF CONVECTION WILL BE
ALONG WITH HEAVY RAINFALL. MODELS INDICATE THIS BOUNDARY WILL PUSH
FURTHER WEST AS THE DAYTIME PROGRESSES...AND THEN RETREAT EASTWARD
TOWARDS THE I25 CORRIDOR EARLY IN THE MORNING AND AROUND
SUNRISE...WITH SURFACE OBS LIKELY SHOWING A WESTERLY WINDS AS IT
RETREATS EASTWARD. THEREFORE...EACH DAY WILL BE SIMILAR WITH AT
LEAST A SCATTERED COVERAGE OF SHOWERS AND TSTORMS EACH DAY FROM
MONDAY EVENING THROUGH WEDNESDAY EVENING. 0-6 KM SHEAR WILL
RANGE FROM 35 TO 45 KNOTS EACH DAY...SUGGESTING SOME STRONG TO
MARGINALLY SEVERE TSTORMS EACH DAY THROUGH WEDNESDAY. ADJUSTED POP
ALONG AND EAST OF THE LARAMIE RANGE WITH VALUES BETWEEN 30 TO 45
PERCENT...HIGHEST IN THE AFTERNOON AND EVENING HOURS.
HOWEVER...WOULD NOT BE SURPRISED IF THESE STORMS OR SHOWERS
LINGERED WELL INTO THE OVERNIGHT HOURS DUE TO AVAILABLE MOISTURE
AND UPPER LEVEL DISTURBANCES MOVING OVER THE AREA.
ON THURSDAY...MODELS SHOW THE UPPER LEVEL FLOW BECOMING MORE
SOUTHWESTERLY AND INCREASING IN STRENGTH AHEAD OF A POTENT PACIFIC
STORM SYSTEM MOVING ONSHORE. THIS WILL RESULT IN THE LLVL
BOUNDARY...WHICH HAS ACTED SIMILAR TO A DRY LINE...FINALLY
RETREATING A BIT FURTHER EASTWARD...LIMITING CONVECTION TO THE
HIGH PLAINS WITH ONLY ISOLATED COVERAGE THURSDAY AFTERNOON. FRIDAY
APPEARS TO BE A TRANSITIONAL DAY...WITH THE HIGHLY AMPLIFIED 00Z
ECMWF SHOWING THE POTENT UPPER LEVEL TROUGH AND ASSOCIATED PACIFIC
STORM SYSTEM MOVING ACROSS THE GREAT BASIN REGION AND INTO THE
FORECAST AREA...BRINGING WIDESPREAD RAIN SHOWERS AND ISOLATED
THUNDER ALONG WITH MUCH COOLER TEMPERATURES. THE GFS IS NOT AS
AMPLIFIED AND IS CONSIDERABLY SLOWER WITH THE TROUGH...WITH A
PLEASANT DAY SETTING UP OVER THE FORECAST AREA ON FRIDAY.
BELOW NORMAL TEMPERATURES EARLY THIS WEEK WITH GRADUALLY WARM UP
BY THE MIDDLE OF THE WEEK AS HIGHS INCREASE INTO THE 80S TO NEAR
90 BY THURSDAY AFTERNOON. LOWERED TEMPERATURES A FEW DEGREES ON
FRIDAY WITH SOME UNCERTAINTY...BUT STILL NEAR NORMAL FOR THE TIME
OF THE YEAR.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY MORNING)
ISSUED AT 1148 AM MDT SAT JUN 21 2014
MAIN CONCERN FOR THIS FORECAST CYCLE IS THE THUNDERSTORM POTENTIAL
THIS AFTERNOON AND EVENING. THE KCYS RADAR IS ALREADY STARTING TO
LIGHT UP WITH SHOWERS AND THUNDERSTORMS DEVELOPING BETWEEN KCYS
AND KDGW. FOR NOW...HAVE KEPT VCTS IN THE TAFS GIVEN THE
UNCERTAINTY IN TIMING AND PRECISE LOCATION. WILL CONTINUE TO
MONTIOR THUNDERSTORM TRENDS THRU THE REST OF THE AFTERNOON MAINLY
FOR AIRFIELDS TO THE EAST OF THE LARAMIE RANGE. CONVECTION WILL
DISSIPATE BY AROUND SUNSET AS THE THUNDERSTORMS PUSH EAST TOWARDS
CENTRAL NEBRASKA. A COLD FRONTAL WILL PUSH SOUTH THROUGH THE AREA
TONIGHT...SO EXPECT WINDS TO TURN NORTHERLY ALONG WITH POTENTIALLY
A PERIOD OF MVFR CIGS AT KCDR/KAIA. NORTHERLY WINDS WILL TURN
GUSTY LATE SUNDAY MORNING WITH ANOTHER ROUND OF AFTERNOON
THUNDERSTORMS EXPECTED JUST BEYOND THIS TAF CYCLE FOR SUNDAY.
&&
.FIRE WEATHER...
ISSUED AT 312 AM MDT SAT JUN 21 2014
STILL SEE MINIMAL FIRE WEATHER IMPACTS THROUGH THE WEEKEND.
AFTERNOON HUMIDITY VALUES WILL DROP TO 10 TO 15 PERCENT FOR AREAS
ALONG AND WEST OF THE LARAMIE RANGE THIS AFTERNOON AND ON SUNDAY.
WEST TO SOUTHWEST WINDS WILL OCCASIONALLY GUST TO 30 MPH IN THE
HIGHER TERRAIN DURING THE PERIOD OF PEAK MECHANICAL MIXING BOTH
AFTERNOONS. HOWEVER...NO CRITICAL FIRE WEATHER THREAT IS
ANTICIPATED SINCE FUELS HAVE STILL NOT DRIED ENOUGH TO SUPPORT
SIGNIFICANT FIRE GROWTH. WE ARE STILL EXPECTING COOLER
TEMPERATURES SUNDAY INTO EARLY NEXT WEEK ALONG WITH A BETTER
CHANCE OF WETTING RAINS...ESPECIALLY TO THE EAST OF THE LARAMIE
RANGE.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...FINCH
SHORT TERM...GARMON
LONG TERM...TJT
AVIATION...HAHN
FIRE WEATHER...GARMON
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1113 AM MDT SAT JUN 21 2014
.UPDATE...
ISSUED AT 1100 AM MDT SAT JUN 21 2014
NOT A WHOLE LOT OF CHANGES MADE TO THE AFTN GRIDS. WEAK SHORTWAVE
IS SEEN ON WATER VAPOR IMAGERY OVER NORTHWEST COLORADO WITH
WIDESPREAD MID TO HIGH LEVEL CLOUDS CURRENTLY OVER SOUTHEAST WY. A
LITTLE WORRIED THAT THIS CLOUD COVER WILL LIMIT SFC HEATING AND
INSTABILITY THIS AFTN...ALTHOUGH WHERE STRONG TO SVR TSTM
POTENTIAL IS HIGHEST (NEBRASKA PANHANDLE) THERE HAS BEEN GOOD
WARMING THROUGH THE MORNING. THE HRRR MODEL HAS BEEN CONSISTENT AT
SHOWING A LARGE AREA OF SHOWERS AND EMBEDDED TSTMS OVER THE
PANHANDLE BETWEEN 22-01Z...WITH A MULTICELL APPEARANCE. WILL
CONTINUE THE MENTION OF SLIGHT RISK OF SVR STORMS IN THE
HWO...ALTHOUGH BULK SHEAR LOOKS A BIT MARGINAL AT 30-35 KTS FOR
MORE DISCRETE SUPERCELLS.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 312 AM MDT SAT JUN 21 2014
GLOBAL MODELS AND CURRENT WATER VAPOR IMAGERY SHOW A SHORTWAVE
APPROACHING FROM THE SOUTHWEST THAT IS PROGGED TO MOVE ACROSS OUR
AREA DURING THE AFTERNOON/EVENING HOURS TODAY. AT THE SURFACE...WE
NOTE A WELL DEFINED DRYLINE THAT EXTENDS FROM JUST NORTHWEST OF
CHADRON TO JUST EAST OF CHEYENNE. EAST OF THE DRYLINE MUCAPES ARE
RUNNING 400-800 J/KG ALREADY AND EXPECT BY THIS AFTERNOON WE WILL
SEE ENOUGH DEEP LAYERED INSTABILITY TO LIGHT OFF A FEW STRONG TO
SEVERE STORMS OVER THE NEBRASKA PANHANDLE WITH CAPES APPROACHING
2500 J/KG AND 1-6KM BULK SHEAR 25 TO 30 KTS ACROSS THE NORTHERN
NEBRASKA PANHANDLE...SUGGESTING THAT A FEW STORMS COULD START
TAKING ON SUPERCELL CHARACTERISTICS AS THEY MOVE EAST OUT OF
EASTERN WYOMING INTO NORTHWESTERN NEBRASKA. MODEL AND OBSERVED
SOUNDING DATA SHOW JUST ENOUGH OF A MIDLEVEL CAP TO HOLD BACK
CONVECTION UNTIL THE MID AFTERNOON HOURS...THEN BY 3 PM WE EXPECT
TO SEE SCATTERED STORMS INITIATING EAST OF A LUSK TO CHEYENNE
LINE...STRENGTHENING AS THEY MOVE EASTWARD INTO THE DEEPER
MOISTURE AND ZONE OF HIGHER INSTABILITY THROUGH LATE AFTERNOON
INTO THE EVENING HOURS. MAIN CONCERN FOR SEVERE STORMS IMPACTS
TODAY IS LARGE HAIL AND DAMAGING DOWNBURST WINDS IN EXCESS OF 60
MPH...MAINLY EAST OF A LINE FROM LUSK TO SIDNEY...ALTHOUGH
GREATEST POTENTIAL FOR VERY LARGE HAIL... HIGHER DOWNDRAFT WINDS
AND TO A LESSER DEGREE TORNADOES WILL BE FARTHER TO THE
EAST/NORTHEAST INTO SOUTH DAKOTA AND NORTHERN NEBRASKA WHERE SHEAR
VALUES FOR ORGANIZED UPDRAFTS WILL BE HIGHER.
LOOKING FARTHER TO THE WEST TODAY...LATEST HIGH RESOLUTION RAPID
REFRESH MODEL DOES HINT AT SOME WEAKER SHOWERS/STORMS FORMING UP
IN THE EARLY AFTERNOON IN THE HIGHER TERRAIN OVER OUR WESTERN
ZONES. WE CONTINUE TO MAINTAIN SLIGHT CHANCE/CHANCE POPS FOR
AFTERNOON SHOWERS AND STORMS IN THE WEST WITH THE EXCEPTION OF
THE WESTERN-MOST AREAS OF CARBON COUNTY. ANOTHER BREEZY DAY
EXPECTED ABOVE 8000 FT MSL WITH GUSTS TO 35 MPH POSSIBLE DURING
THE PEAK MECHANICAL MIXING PERIOD OF MID MORNING THROUGH LATE
AFTERNOON.
WE EXPECT ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS ON SUNDAY AS
A COLD FRONT SINKS SOUTHWARDS AND IS PROGGED IN THE MODELS TO BANK
UP ALONG AND EAST OF THE LARAMIE RANGE BY LATE AFTERNOON. MOST OF
THE STORMS SUNDAY SHOULD BE NOTED EAST OF A LINE FROM DOUGLAS TO
CHEYENNE IN THE REGION OF DEEPER MOISTURE AND INSTABILITY...WITH
LESS COVERAGE TO THE WEST. DEEP LAYERED INSTABILITY FOR STRONG
UPDRAFTS LOOKS A LITTLE MORE LIMITED ON SUNDAY...HOWEVER BULK
SHEAR VALUES ACROSS EASTERN WYOMING AND WESTERN NEBRASKA COULD GET
UP TO NEAR 30 KTS...SO A SMALL POTENTIAL FOR A FEW STRONGER
STORMS IS THERE. THE KEY THING WE WILL NEED TO WATCH FOR ON SUNDAY
WILL BE THE POTENTIAL FOR STORMS TO RE-DEVELOP OR TRAIN GRADUALLY
FROM NORTHWEST TO SOUTHEAST...MEANING SOME AREAS COULD SEE
MULTIPLE ROUNDS OF RAINFALL. QUESTION IS JUST HOW FAR SOUTH WILL
THE FRONTAL BOUNDARY GET AND IF WE WILL SEE ENHANCED BACK-BUILDING
OF STORMS WITH EAST/SOUTHEAST SURFACE FLOW WITH 25-35 KT MIDLEVEL
FLOW ABOVE IT. RIGHT NOW FORECAST CONFIDENCE AS TO IF OR WHERE ANY
FLASH FLOODING WOULD OCCUR ON SUNDAY IS NOT NEAR HIGH ENOUGH TO
WARRANT THE ISSUANCE OF A WATCH.
FOR MONDAY...MORE SCATTERED AFTERNOON SHOWERS AND THUNDERSTORMS
ARE EXPECTED FOR THE CENTRAL AND EASTERN ZONES IN THE REGION OF
DEEPER MOISURE.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 312 AM MDT SAT JUN 21 2014
MODELS IN GENERALLY GOOD AGREEMENT WITH THE OVERALL PATTERN
THROUGH MOST OF NEXT WEEK...ALTHOUGH SOME DIFFERENCES ARE NOTED
BY DAY 7 REGARDING THE TIMING OF AN UNUSUALLY STRONG UPPER LEVEL
TROUGH ACROSS THE PACIFIC NORTHWEST FOR THIS TIME OF THE YEAR. THE
WEATHER PATTERNS APPEARS TO BE PRETTY ACTIVE NEXT WEEK AS A SERIES
OF SHORTWAVE DISTURBANCES EMBEDDED WITHIN THE QUASI-ZONAL FLOW
PUSH ACROSS THE FORECAST AREA EACH DAY THROUGH THURSDAY.
A LOW LEVEL SURFACE BOUNDARY WILL BE THE PRIMARY FACTOR IN
DETERMINING CONVECTION INITIATION EACH DAY DUE TO AMPLE LLVL
CONVERGENCE AND ADDITIONAL INSTABILITY. THE BOUNDARY POSITION WILL
FLUCTUATE BETWEEN THE CONTINENTAL DIVIDE AND ALONG THE I25
CORRIDOR THROUGH THE PERIOD...RESULTING IN SOME DIFFICULTY IN
PINPOINTING WHERE THE HIGHEST POTENTIAL OF CONVECTION WILL BE
ALONG WITH HEAVY RAINFALL. MODELS INDICATE THIS BOUNDARY WILL PUSH
FURTHER WEST AS THE DAYTIME PROGRESSES...AND THEN RETREAT EASTWARD
TOWARDS THE I25 CORRIDOR EARLY IN THE MORNING AND AROUND
SUNRISE...WITH SURFACE OBS LIKELY SHOWING A WESTERLY WINDS AS IT
RETREATS EASTWARD. THEREFORE...EACH DAY WILL BE SIMILAR WITH AT
LEAST A SCATTERED COVERAGE OF SHOWERS AND TSTORMS EACH DAY FROM
MONDAY EVENING THROUGH WEDNESDAY EVENING. 0-6 KM SHEAR WILL
RANGE FROM 35 TO 45 KNOTS EACH DAY...SUGGESTING SOME STRONG TO
MARGINALLY SEVERE TSTORMS EACH DAY THROUGH WEDNESDAY. ADJUSTED POP
ALONG AND EAST OF THE LARAMIE RANGE WITH VALUES BETWEEN 30 TO 45
PERCENT...HIGHEST IN THE AFTERNOON AND EVENING HOURS.
HOWEVER...WOULD NOT BE SURPRISED IF THESE STORMS OR SHOWERS
LINGERED WELL INTO THE OVERNIGHT HOURS DUE TO AVAILABLE MOISTURE
AND UPPER LEVEL DISTURBANCES MOVING OVER THE AREA.
ON THURSDAY...MODELS SHOW THE UPPER LEVEL FLOW BECOMING MORE
SOUTHWESTERLY AND INCREASING IN STRENGTH AHEAD OF A POTENT PACIFIC
STORM SYSTEM MOVING ONSHORE. THIS WILL RESULT IN THE LLVL
BOUNDARY...WHICH HAS ACTED SIMILAR TO A DRY LINE...FINALLY
RETREATING A BIT FURTHER EASTWARD...LIMITING CONVECTION TO THE
HIGH PLAINS WITH ONLY ISOLATED COVERAGE THURSDAY AFTERNOON. FRIDAY
APPEARS TO BE A TRANSITIONAL DAY...WITH THE HIGHLY AMPLIFIED 00Z
ECMWF SHOWING THE POTENT UPPER LEVEL TROUGH AND ASSOCIATED PACIFIC
STORM SYSTEM MOVING ACROSS THE GREAT BASIN REGION AND INTO THE
FORECAST AREA...BRINGING WIDESPREAD RAIN SHOWERS AND ISOLATED
THUNDER ALONG WITH MUCH COOLER TEMPERATURES. THE GFS IS NOT AS
AMPLIFIED AND IS CONSIDERABLY SLOWER WITH THE TROUGH...WITH A
PLEASANT DAY SETTING UP OVER THE FORECAST AREA ON FRIDAY.
BELOW NORMAL TEMPERATURES EARLY THIS WEEK WITH GRADUALLY WARM UP
BY THE MIDDLE OF THE WEEK AS HIGHS INCREASE INTO THE 80S TO NEAR
90 BY THURSDAY AFTERNOON. LOWERED TEMPERATURES A FEW DEGREES ON
FRIDAY WITH SOME UNCERTAINTY...BUT STILL NEAR NORMAL FOR THE TIME
OF THE YEAR.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY)
ISSUED AT 312 AM MDT SAT JUN 21 2014
LOW LEVEL MOISTURE IS CURRENTLY PUSHING FURTHER NORTH AND WEST
EARLY THIS MORNING WITH DEWPOINTS IN THE UPPER 50S TO AROUND 60
ACROSS WESTERN NEBRASKA. LOW LEVEL MOISTURE TO CONTINUE
INCREASING OVERNIGHT...SETTING THE STAGE FOR SHOWERS AND TSTORMS
SATURDAY AFTERNOON MAINLY EAST OF THE LARAMIE RANGE. ACTIVITY WILL
BEGIN AS RAIN SHOWERS WEST OF THE LARAMIE RANGE AROUND 18Z...AND
EVENTUALLY PUSH EASTWARD TOWARDS KLAR...KCYS IN THE AFTERNOON. COLD
FRONT STILL FORECAST TO MOVE SOUTHWARD ACROSS THE EAST SLOPES OF
THE LARAMIE RANGE LATE SATURDAY NIGHT WITH UPSLOPE WINDS EAST OF
THE FRONT. WOULD EXPECT THIS TIME FRAME TO BE THE BETTER CHANCE
FOR MORE WIDESPREAD MVFR/IFR CONDITIONS. SO...TRENDED THE TAFS
THAT WAY WITH LOWERING CLOUDS LATE IN THE 06Z TAF CYCLE.
&&
.FIRE WEATHER...
ISSUED AT 312 AM MDT SAT JUN 21 2014
STILL SEE MINIMAL FIRE WEATHER IMPACTS THROUGH THE WEEKEND.
AFTERNOON HUMIDITY VALUES WILL DROP TO 10 TO 15 PERCENT FOR AREAS
ALONG AND WEST OF THE LARAMIE RANGE THIS AFTERNOON AND ON SUNDAY.
WEST TO SOUTHWEST WINDS WILL OCCASIONALLY GUST TO 30 MPH IN THE
HIGHER TERRAIN DURING THE PERIOD OF PEAK MECHANICAL MIXING BOTH
AFTERNOONS. HOWEVER...NO CRITICAL FIRE WEATHER THREAT IS
ANTICIPATED SINCE FUELS HAVE STILL NOT DRIED ENOUGH TO SUPPORT
SIGNIFICANT FIRE GROWTH. WE ARE STILL EXPECTING COOLER
TEMPERATURES SUNDAY INTO EARLY NEXT WEEK ALONG WITH A BETTER
CHANCE OF WETTING RAINS...ESPECIALLY TO THE EAST OF THE LARAMIE
RANGE.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...FINCH
SHORT TERM...GARMON
LONG TERM...TJT
AVIATION...TJT
FIRE WEATHER...GARMON